Thermoplastic Compositions with Improved Light Stability

* GB786144 (A)
Description: GB786144 (A) ? 1957-11-13
Thermoplastic compositions having improved light stability
Description of GB786144 (A)
Translate this text into Tooltip
[75][(1)__Select language]
Translate this text into
The EPO does not accept any responsibility for the accuracy of data
and information originating from other authorities than the EPO; in
particular, the EPO does not guarantee that they are complete,
up-to-date or fit for specific purposes.
COMPLETE SPECIFICATION
Thermoplastic Compositions having improved Light Stability
We, THE DOW CHEMICAL COMPANY, a
Corporation organized and existing under the
Laws lof the State of Delaware, United States of America, of Midland,
Ciounty of Midland,
State of Michigan, United States of America, do hereby declare the
invention for which we pray that a patent may be granted to us and the
method by which it is to, be performed, to be particularly described
in sand by the following statement:
This invention relates to new and improved thermoplastic compositions.
More particularly it relates to polymeric compositions having improved
stability to the degradaltive effects of sunlight.
Thermoplastic compositions, particularly those prepared from
haloethylene polymers, have found wide acceptance as useful materials
for making foils, fibres, filaments, and other articles. The articles
so produced are inherently strong, dimensionally stable, reSa- tively
inert to common household solvents, and are early coloured for an
attractive appearance. However, such articles are subelect to rapid
and severe degradation and consequent discoloration due to the effects
of heat and light. The problem becomes most serious when polymeric
compositions are empioyed las filamentary materials in making window

curtains, automobile seat covers, and other articles which are exposed
for prolonged periods of time to direct sunlight. To civer- come this
disadvantage it has become most practical to incorporate certain
additives into the composition to stabilize it to the effects of heat
and to add other materials to the composition to stabilize it to the
effects of light. Some d the prior light stabilizing materials h!ave
suffered from the disadvantages of bleeding out of articles made from
vinyl or vinylidene halides. In addition, some of the materials are
coloured so that they impart an objectionable initial colour which
prevents the production of white articles. Further, many of the prior
materials lose their effectiveness as light stabilizers after exposure
to sunlight for a short time.
It is accordingly an object of this invention to provide improved
polymeric compositions having increased resistance to the degradative
effects of light
It is a further object to provide such a composition which is based on
a chlloroethylene polymer and is resistant to the effects of light
over prolonged - periods of exposure to direct sunlight.
According to the present invention there is provided a light stable
composition comprising an organic thermoplastic material normally
subject to discoloration on exposure to light and from 0.1 to 10 per
cent. of the weight of said thermoplastic of a dibenzoyl resorcinol
compound as a stabilizer having the general formula:
<img class="EMIRef" id="026598829-00010001" />
wherein R1 to R,, inclusive, are selected from
H, Cl, Br, F, an alkyl group having from 1 to 8 carbon atoms, and
POOR7 wherein
R, is selected from an alkyl group having from 1 to 8 carbon atoms,
phenyl, monochllorophenyl, monobromophenylrand monow alkylphenyl, and
RG is selected from R1, benzoyl, and benzoyl substituted with R1 and
R2; there being not more than 4 bromine atoms, not more than 3
fluorine atoms, not more than 3 -CO OR7 groups in the compound, and
not more than one -CO OR7 group attached to any benzene ring. The
compositions of this invention show effective resistance to the
degradative effects of light -even after prolonged exposure.
Among the specific compounds defined by the foregoing formula and
which have light stabilizing action in thermoplastic compositions are:
2)4-dibenzoyl! resorcinol 4,6-dibenzoyl resorcinol 2,4-dibenzoyl,
6-chlororesoranol 2.,4-dibenzoyl, 6-hexyiresorcinol 2,4-di(4-chlorob
enzoyl)resorcinol 2,4-di(4-bromobenzoyl)resoranol
2,4-di(4-fiuorohenzoyl)resorcinol
2,4-di(2,4-dichlorobenzoyl)resorcinol 2 >
4-di(2A-dibromobenzoyi)resorcinol
2,4-di(2,4,6-trichlorobenzoyl)resorcinol

2,4di(4-methylbenzoyl)resorcinol 2,4-di(4-butylbenzoyl)resorcinol
3,5-dibenzoyl, 2,4-dihydroxybenzoic acid,
methyl ester 3,5-dib enzoyl, 2,4-dihydroxybenzoic acid,
butyl ester.
3,5-dibenzoyl, 2,4-dihydroxybenzoic acid, 2
ethylhexyl ester 3,5-dibenzoyl, 2,4 - dihydroxybenzoic acid,
phenyl ester 3,5-dibenzoyl, 2,4-dihydroxybenzoic acid, 4
chlorophenyl ester 3,5-dibenzoyl, 2,4-dihydroxybenzoic acid, 4
bromophenyl ester 2,4di(monomethylphthaloyl)resorcinol
3,5di(monomethylphthaloyi), 2,4-dihydroxy
benzoic acid., methyl ester.
The polymers which may be employed in the compositions of this
invention may be selected from a wide variety of polymers, such as
polystyrene, polyethylene, and cellulosic esters and ethers. However,
especially advantageous results are obtained when haloethylene
pdlymers, such as the polymers of vinyl chloride, copolymers of vinyl
chloride and vinylidee chloride, and copolymers of vinylidene chloride
with other copolymerizable monomers in which the vinylidene chloride
is present in an amount of at least 50 per cent.
of the copolymer are employed, and such polymers are preferred in
preparing the oom- positions. The baloethylene polymers present an
unusual problem in that once degradation has started the effect seems
to be autocatalytic, and thus the problem of stabilization is made
more difficult
Dibenzoyl resorcinol may be easily prepared from readily available
materials by a number of known methods. One such method consists of
subjecting an orthodichioroben- zene solution of resorcinol benzoyl
chloride, and a slight excess aluminium chloride to a temperature of
135 C. for one-half hour after which' dilute HO is padded to the
reaction mixture. The product may be purified by distillation or by
recrystailization from methanol or by both processes. When produced by
this method the product is found to consist substantially of from 75
to 90 per cent. of the 2,4-dibenzoyl resorcinol isomer and from 10 to
25 per cent. of the 4,6-dibenzoyl resorcinol derivative. Such mixtures
present no problem, however, since the mixture has been found to be
equivalent to either of the two isomers in light stabilizing
effectiveness. The substituted derivatives of dibenzoyl resorcinol may
be prepared by using the correspondingly substituted resorcinol or
benzoyl chloride as starring materials.
The dibenzoyl resorcinol derivatives may be employed in amounts of
from 0.1 to 10 per cent. by weight based on the weight of the polymer,
preferably from 0.25 to 3 per cent. by weight. Most pclymeric
compositions comprise many ingredients such as plasticizers, fillers,
pigments, and heat stabilizers, and the derivatives of this invention

may be employed in the compositions in conjunction with such additives
without any adverse effects. Likewise, the dibenzoyl resorcinol
derivatives of this invention may be used in conjunction with other
known light stabilizers. When so used, the dibenzoyl resorcinol
derivative enhances the light stabilizing effectiveness of the known
stabilizer to a surprising degree.
The ingredients may be intermixed by milling or blending by known
conventional methods.
The compositions of this invention show superior resistance to
degradation due to light over any previously known compositions
Following is a description by way of example of methods of canying the
invention into effect. In the examples all parts are parts by weight
EXAMPLE 1.
A series of three samples were made consisting of 90 parts of a
copolymer prepared from a monomeric mixture consisting of 85 per cent.
vinylidene chloride and 15 per cent.
vinyl chloride, 7 parts of acetyl triethyl dt- rate as plasticizer and
one part of tetra- sodium pyrophosphate as a heat stabilizer. To one
of the samples was added 2 parts of 2hydroxy 5-chiorobenophenone, a
known light stabilizer. The second sample had no light stabilizer
added, and ro the third sample was added 1 part of a mixture of 2,4-
and 4,6dibenzoyl resorcinol isomers. Each sample was moulded into a
sheet 0.01 inch thick. All of the sheets were then exposed to direct
sunlight in the State of Florida for 3 months. After exposure the
sheets were examined visually snd rated for colour according to an
arbitrary scale in which 0 means no colour, 5= yellow; 10= tan; and
20=black. The results of this test are given in Table I.
TABLE I.
Original Colour after Numerical Stabilizer colour exposure rating
None colourless very dark brown 17 2-Hydroxy 5-chloro- light
benzophenone yellow tan 10
Dibenzoyl resorcinol colourless slight yellowing 4
From the results it can be seen that dibenzoyl resorcinol is far
better as a light stabilizer for vinylidene chloride copolymers than
is 2-hydroxy 5-chlorobenzophenone which is a commercially accepted
light stabilizer. In addition the dibenzoyl resorcinol does not impart
an initial yellow colour to the polymer as did the other stabilizer.
EXAMPLE 2.
Samples were prepared to check the effectiveness lof various
substituent groups on 'the light stabilizing effectiveness of subs'tl-
tured dibenzoyl resorcinols. The formulation consisred of 100 parts of
polyvinyl chloride, 50 parts of dioctyl plithalate, 3 parts of known
organo-metallic heat stabilizers, 0.1 part of stearic acid as a
lubricant, and 1 part of the new light stabilizer. The samples were

prepared by milling on a two roll mill, after which they were moulded
into sheets having a thickness of 0.025 inch. The original colour of
the sheet was noted and the samples were then lexposed to the
radiation of a sunlamp for 35, 53 and 93 days which corresponds
respectively to 500, 1000 and 2000 ultra-violet sun hours. The samples
were examined after each period of exposure and the amount of colour
change from the original colour rated according to an arbitrary scale.
In this scale a rating of 0 means no change, 5 indicates yellowing, 10
indicates Tan, and 20 indicates a black colour. (When the samples had
an original colour which disappeared or was reduced on exposure [a
minus sign indicates the amount of bleaching that occurred. The higher
the numerical value the greater was the bleaching). The results are
tabulated in Table
II.
TABLE II
Colour Rating After
Time in Days
Stabilizer Original Colour 35 53 93
None 7 17 20
Salol Slightly yellow 2 4 6* 2-Hydroxy 5-chloro
benzophenone do. 0 4+ 20
Monobenzoyl resorcinol do. -1 -1 0
Tribenzoyl resorcinol do. -2 -2 -2 2,4-Dibenzoyl resorcinol do. -4 -4
-4 4,6-Dibenzoyl resorcinol do. -6 -6 -6
Di(4-chlorobenzoyl)
resorcinol do. -5 -5 -5 Di(2,4-dichiorobenzoyl)-
resorcinol Yellow -6 -6 -6
* dark spots
+ tacky surface
From the tabulated results it can be seen that the new stabilizers
give better protection than known light stabilizers and better than
the closely related monobenzoyl resorcinol.
EXAMPLE 3.
The light stabilizing etiectiveness of dibenzoyl resorcinol in
polystyrene was tested by thoroughly intermixing polystyrene with 1
per cent. of its weight of dibenzoyl resorcinol.
Sheets were moulded from both the stabilized composition and
polystyrene alone. The samples were checked for colour by measuring
the amount of transmittancy of light 6200at minus the amount of
transmittancy of light of 4200A". After exposure to direct sunlight in
the State of Florida for three months ithe colour Was again measured.
The results are tabulated in Table Ill.
TABLE III.
Transmlittancy 1% Change in

Stabilizer Original After 3 Months Transmittancy
None 2.1 20.9 18.s
Dibenzoyl resorcinol 23.9 27.7 3.8
The results indicate that the sample having no stabilizer had greater
than an 18 per cent darkening in colour while the sample stabilized
with dibenzoyl resorcinol had less than 4 per cent. darkening.
EXAMPLE 4.
Samples were prepared to test the compatibility and the effectiveness
of mixtures of light stabilizers. The samples were prepared as ain
Example 2 except that the formulation consisted of 89 parts of a
copolymer prepared from 85 per cent. vinylidene chloride and 15 per
cent vinyl chloride, 0.5 part of sodium tripolyphosphate, 0.5 part of
disodium lauryl phosphate, 5 per cent. Hercofiex 600 as plasticizer,
and a total of 5 per cent of the indicasted light stabilizers. The
samples were exposed in the State of Florida for 3000 ultraviolet sun
hours. They were checked periodically for amount of colour change and
the potentisily useful life of the formulation talon to be the time
required to reach a yellow colour. These results are listed in Table
IV.
TABLE IV
Useful Life
(Ultra-Violet
1st Stabilizer % 2nd Stabilizer % Sun Hours) 2-Chloro-5-hydroxy
benzophenone 3.0 - - 500
Dibenzoyl resorcinol 3.0 - - > 1500 2-Chloro-5-hydroxy
benzophenone 2.0 Salol 3.0 440 2-Chloro-5-hydroxy
benzophenone 2.0 Dibenzoyl 3.0 > 1000 resordnol
It can be seen that the mixtures contain
ing dibenzoyl resorcinol are better than twice
as stable to light us the mixtures containing the salol. Such an
increase is of great significance when polymeric products are
fabricated
into articles which may be exposed to sun
light for prolonged periods.
ExAMPLE 5.
A series of samples was prepared to check the effectiveness of the
dibenzoyl resorcinol deprivatives when used in compositions together
with different plasticizers some of which could not be used previously
due to resulting instability of the plasticized compositions. The
basic formulation consisted of 91 parts of a copolymer prepared from a
monomeric mix
ture consisting of 85 pet cent. vinylidene
chloride and 15 per cent vinyl chloride, 0.5 part of sodium
tripolyphosphate and 0.5 part

of sodium laurel phoshate as heat stabilizers, 3 parts of a mixture of
2,4- and 4,6dibenzoyl resorcinol, and 5 parts of the plasticizer.
By nvay of comparison a second series of samples was prepared
identical to the first except that 3 parts of 2-hydroxy
5-chlorobenzophenone were employed in place of the mixture of
dibenzoyl resorcinol isomers.
All of the samples were mixed by milling on a two roll mill and then
compression moulded into test strips. The test strips were exposed to
direct sunlight in the State of
Arizona for 1000 ultra-violet sun hours. The strips were examined
periodically for discoloration and the potential useful life of each
composition taken as the number of ultraviolet sun hours needed to
reach a yellow discoloration. These results may be found in
Table V.
TABLE V.
Useful Life (Ultra-violet Sun Hours) 2-Hydroxy,
Dibenzoyl 5-Chloro
Plasticize Resorcinol benzophenone Acryl trioctyl citrate > 1000 400
Pentaeethritoi tetraester of a mixture of > 1000 325
saturated fatty acids (av. chain length=CO)
Polyester of propylene glycol and adipic and > 1000 375
lauric acids
Polyester of propylene glycol and sebacic 540 275
acid
Chlorinated diphenyl (68% Gl) 420 275
Chlorinated terphenyl (42% Cl) 310 200
The results show that the useful life of the articles can be extended
from 1.5 to 3 times as long as that of similar articles made of
previously known compositions. Thus, where some plasticizers could not
ba employed in the past because of the instability of the plasricized
compositions to light, those sate plasticizers may now be used in
producing stable compositions.
The dibenzoyl resorcinols and their defined substitution products are
useful light stabilizers for all thermoplastic compositions which are
normally subject to discoloration due to ultraviolet radiation. Thus,
in addition to the polystyrene, polyvinyl chloride, and vinyl
chloride-vinylidene chloride copolymers of the examples, these agents
exhibit their protective effect when incorporated in cellulose
acetate, ethyl cellulose, polyacrylonitrile, and other thermoplastic
film- or fibre-forming compositions
What we claim is: -
1. A light stable composition comprising an organic thermoplastic
matcrial normally subject to discoloration lon exposure to light and
from 0.1 to 10 per cent. of the weight of said thermoplastic of a

dibenzoyl resorcinol compound as a stabilizer having the general
formula:
<img class="EMIRef" id="026598829-00050001" />
wherein R1 to Rn, inclusive, are selected from
H, C1, Br, F, an alkyl group having from 1 to 8 carbon atoms, und
-COOR7 wherein R, is selected from an alkyl group having from 1 to 8
carbon atoms, phenyl, n onochlloro- phenyl, monobromophenyl and
monoalkyl- phenyl, and R6 is selected from R1, benzoyl, and benzoyl
substituted with R1 and R, there being not more Ithan 4 bromine atoms,
not more than 3 fluorine atoms nor more than 3 -CO OR, groups in the
compound, and not more than one -CO OR group attached to any benzene
ring.
2. The composition claimed in claim 1 wherein the derivative of
dibenzoyl resorcinol is present in an amount of from 0.25 to 3 per
cent. by weight
3. The composition claimed in claim 1 wherein the stabilizer is a
mixture of 2,4-dibenzoyl resorcinol and 4,6-dibenzoyl resorcinol.
4. The composition claimed in claim 1 wherein the thermoplastic
material is polyvinyl chloride.
5. The composition claimed in claim 1 wherein the thennopilastic
material is a Co- polynter of vinylidene chloride and vinyl chloride.
6. The composition claimed in claim i wherein the thermoplastic
material is a Co- polymer of at least 50 per cent vinylidene chloride
and another polymerizable monomer.
7. A composition comprising a predominantly vinylidene chloride
copolymer and from 0.1 to 10 per cent,. based on the weight of the
copolymer of dibenzoyl resorcinol.
8. A composition comprising a predominantly vinylidene chloride
copolymer and from 0.1 to 10 per cent based on the weight of the
copolymer of di-(2-chlorobenzoyl)-resorcinol.
9. A composition comprising a predomingently vinylidene chloride
copolymer and from 0.1 to 10 per cent based on the weight of the
copolymer of di-(4-chlorobenzoyl) - resorcinol.
copolymer and from 0.1 to 10 per onit, based on the weight of the
copolymer, of di-(2,4dichloro- benzoyl)resorcinol.
copolymer and from 0.1 to 10 per cent, based on the weight of the
copolymer, of tribenzoyi resorcirol.
12. A composition substantially as described
* GB786145 (A)

Description: GB786145 (A) ? 1957-11-13
Preparation of optically active isomers of threo--ss-(p-nitrophenyl)-
serine-methylester
Preparation of Optically Active Isomers of Threo@-(pw
Nitrophenyl)-Serine-Methylester
We, CHINON GYOGYSZER ES VEGYESZBTI TERMEKEK GYARA R. T. a body
corporate organise under the laws of Hungary, of
To-utca 1-3, Ujpest, Budapest IV, Hungary, do hereby declare the
invention, for which we pray that a patent may be granted to us, and :
the method by which it is to be performed to be particularly described
in and by the following statement :-
The present invention is concerne with improvements in or relating to
the preparation of the optically active forms of
threo-~-(pnitrophenyl)-serine-methylester.
Threo-/ ?- (-nitrophenyl)-serine derivatives are intermediates in the
preparation of chlor-
amphenicol, the latter being a substance of high therapeutic value.
Since chloramphenicol is an optically active compound, it is
advantageous to obtain its intermediates in the corresponding
optically active form.
Esters of racemic (p-nitrophenyl)-serines have already been resolved.
According to
Specification No. 715, 876 racemic erythro (p-
nitrophenyl)-serine-ethylester and racemic threo-
(p-nitrophenyl)-serine-ethylester may be
resolved by means of dibenzoyl-(+)-tartaric acid. I. Elphimoff-Felkin,

H. Felkin and Z.
Welvart have mentioned (Bull. de la Soc.
Chim. France (1955) 145), without giving any detail, the resolution of
racemic threo- (p-nitrophenyl)-serine-ethylester by means of
optically active lactic acid. It is to be noted, that racemic threo-
(p > -nitrophenyl-serine-ethylester cannot be split into the optically
active antipodes with d-rartaric acid.
It has now been found according to the present invention, that the
optically active isomers
can be separated ifrom racemic threoS (p-
nitrophenyl)-serine-methylester by fractional crystallisation of the
d-tartaric acid salt of racemic
threo-~-(p-nitrophenyl)-serine-methylester and by isolating from the
diastereoisomeric salts obtained the free methylesters of the
optically active threo-ss-(p-nitrophenyl)- serines.
The fractional crystallisation according to the invention is
preferably carried out using alcohols as solvents. For example when
using methanol as solvent, the d-tartaric salt of
D (-)-threo-R- (p-nitrophenyl)-serine-methylester crystallises out
in an almost quantitative
yield, while the d-tartaric salt of L( + )-threo
~-(p-nitrophenyl)-serine-methylester may be obtained from the mother
liquor in a quantitative yield.
The free optically active methyl ester may be obtained from the
diastereioisomeric salts separated from the fractional crystallisation
by any convenient method. In one such method the salts may be treated
with aqueous ammonia or dilute aqueous alkalis, in order to liberate
the basic esters. Alternatively the salts may be treated with
alcoholic hydrochloric acid, whereby the hydrochlorides of the amino
acid esters are obtained and by liberating then, if desired, the basic
esters by treating the hydrochlorides with alkalis or an
ion-exchanger.
Other methods will be apparent to those skilled in the art.
The methyl ester of racemic threo-, B-(p- nitrophenyl)-serine used in
the present process can be prepared by an convenient methods of
esterification with methanol from the serine.
The preparation of the ester may be carried out for example in the
following manner : 150 ml. abs, methanol are saturated with gaseous
hydrogen chloride and 15 g. of threoss 6 (p- nitrophenyl)-serine are
added. The mixture is then refluxed for 2 hours while hydrogen
chloride gas is passed through. The solution obtained is then
evaporated to dryness, the crystalline residue mixed with ether and
filtered. The hydrochloride of threo-ss (p-nitro-
phenyl)-serine-methylester is obtained which melts with decomposition

at 193-195 C.
The yield is about 98 per cent.
The said hydrochloride of the ester is dissolved in 80 ml. of water,
the solution is filtered and while cooling with ice 100 ml. of 10 per
cent sodium bicarbonate solution is added. Threo--
(p-nitrophenyl)-serine-methylester is precipitated from the
ice-cooled solu tion in a yield of about 80 per cent, which melts with
decomposition at 137-138~ C.
In order that the invention may be well understood, the following
examples are given by way of illustration :-
EXAMPLE I.
2. 40 g. of racemic threo-ss-(p-nitrophenyl)- serine-methyl-ester and
1. 50 g. of d-tartaric acid are dissolved in 50 ml. of methanol by
heating. The solution is allowed to stand overnight at room
temperature. White crystals are formed. The crystals are filtered off,
washed with methanol and dried. The d-rartaric salt of
D(-)-threo-~-(p-nitrophenyl)-serine-methyl serine-methylester is
obtained in a yield of about 75 per cent. It melts at 169-170~ C.
The rotary power is: (?)D: -5~ (H2O 2 per cent).
The mother liquor is evaporated to dryness and the residue
crystallised from 3 ml. of methanol, yielding a further 15 per cent.
of the said salt
On concentrating the mother liquor thus obtained the d-tartaric salt
of L (+)-threo-ss- (p-nitrophenyl)-serine-methyl-ester is obtained.
The pure product melts at 149-150 C.
From the salt having the higher melting point the free aminoacid ester
may be liberated for example as follows : 0. 6 g. of the said salt are
added to a mixture of 3 ml. water and 4 ml of 10 per cent sodium
bicarbonate solution. The precipitated aminoacid ester is then Eltered
off, washed with water and dried.
D (-)-threo-i- (p-nitrophenyl)-serine-methylester is obtained, which
melts with decomposition at 150-151~ C. The rotatory power is : (a)
: 27 (HCI N/1 2 per cent). Yield : about 90 per cent.
The salt having the lower melting point and treated in the same manner
gives L (+)-threo- (3- (p-nitrophenyl)-serine-methylester, the melting
point of which is identical with that of the previous product
EXAMPLE II.
28. 9 g. of d-tartaric acid are stirred in 200 ml. methanol until a
clear solution is obtained.
Then 46.1 g. of racemic threo-~-(p-nitrophenyl)-serine-methylester are
added and stirring is continued for an hour at room temperature. The
reaction mixture is finally refluxed for ten minutes while stirring.
After allowing to cool to room temperature the crystals formed are
filtered ofl, washed with some methanol and dried at 60 C. in vacuo.

36. 85 g. of the d-tartaric salt of Dt)-threo-ss-(p nitro-
phenyl)-serine-methylester are obtained.
Yield : 98. 5 per cent.
The residue obtained on the evaporation of the mother liquor yields
after recrystallization from water the d-tartaric salt of L
(+)-threo-ss-
(p-nitrophenyl)-serine-methylester.
The optically active isomers of threo-/3- (p-
nitrophenyl)-serine-methylester mentioned above have been referred to
as D and L-isomers according to the configuration of the carbon atom
next to the phenyl-residue. The configurations indicated have been
ascertained by the reduction of the D (-)-threo- (p-nitro-
phenyl)-serine-methylester with calcium borohydride to D (-)-threo-l-
(p-nitrophenyl)-2- aminoLl, 3-dihydroxy-propane.
What we claim is :-
1. A process for the separation of the optically active isomers from
racemic threo-~-(pnitrophenyl)-serine-methylester which comprises
separating the d-tartaric acid salts of racemic thrR-
(p-nitrophenyl)-serine-methyl-
ester by fractional crystallisation and isolating the free methylester
of the optically active threo-ss-(p-nitrophenyl)-serine from either or
both of the diastereoisomeric salts obtained.
* Sitemap
* Accessibility
* Legal notice
* Terms of use
* Last updated: 08.04.2015
* Worldwide Database
* 5.8.23.4; 93p
* GB786146 (A)
Description: GB786146 (A) ? 1957-11-13
Aqueous polymer dispersions and method of making the same
A high quality text as facsimile in your desired language may be available

amongst the following family members:
FR1158157 (A)
FR1158157 (A) less
PATENT SPECIFICATION
Inventor: VERNON DEANE FLORIA 786, 146 Date of Application and filing
Complete Specification: April 9, 1956.
No 10757/56.
Complete Specification Published: Nov 13, 1957.
Index at acceptance:-Class 2 ( 6), P 7 C( 2: 8 B: 12 A: 14 A), P 7 D 2
A( 1: 2 A: 2 B), P 7 K 7, P 7 P 1 (B: C:
El: E 3: E 5), P 7 PM(A 3; M X), P 7 (POG; T 2 D).
International Classification;-COf.
Aqueous Polymer Dispersions and method of making the same We, THE Dow
CHEMICAL COMPANY, a corporation organized and existing under the Laws
of the State of Delaware, United States of America, of Midland, County
of Midland, State of Michigan, United States of America, do hereby
declare the invention, for which we pray that a patent may be granted
to us, and the method by which it is to be performed, to be
particularly described in and by the following statement:-
This invention concerns certain new aqueous polymer dispersions and a
method of making the same More particularly, the invention pertains to
aqueous dispersions of interpolymers of major amounts by weight of
non-ionizable vinyl aromatic compounds and minor amounts of ionizable
vinyl aromatic sulphonates It pertains especially to such interpolymer
dispersions which are substantially free of added emulsifiers or
dispersants other than the interpolymers themselves, or the vinyl
aromatic sulphonates employed in making the same The invention also
pertains especially to a method of making such aqueous polymer
dispersions in the absence of added emulsifying agents such as are
conventionally employed in making other aqueous polymer dispersions.
The aqueous interpolymer dispersions which 370 are provided by the
invention are exceptionally stable against coagulation by freezing or

by addition thereto of inorganic salts such for example as sodium
chloride, potassium chloride, sodium sulphate, potassium sulphate or
calcium chloride They are more viscous than water and in some
instances are solid, or non-flowable, at room temperature, but in such
instances are capable of being thinned with water to obtain uniform
aqueous polymer dispersions which are flowable and are of desired
viscosities They are non-gelatinous and are colloidal polymer
solutions such as are sometimes termed synthetic latices They are
useful for a variety of purposes, e g as hydraulic fluids when brought
to concentralPnice' tions having the desired viscosity values, and as
media with which dyes or pigments may be admixed, e g to make
waterpaints The aqueous dispersions of the interpolymers of from 55 to
65 parts by weight per cent of one or more non-ionizable vinyl
aromatic compounds and from 35 to 45 per cent of an alkali metal salt
of a vinyl aromatic sulphonic acid usually possess film-forming
properties, i.e such a dispersion can usually be spread as a thin
layer on a solid surface and be dried to obtain a continuous film of
the solid interpolymer salt The aqueous dispersions of the
interpolymers containing less than 35, e g from 1 to 30, per cent by
weight of the chemically combined vinyl aromatic sulphonate often lack
this film forming property and dry to form a layer of small particles,
or agglomerates, of the solid interpolymers Any of the dispersions
just mentioned can be rendered filmforming by incorporating therewith
a plasticizer, i e an organic material compatible with the
interpolymer Also, plasticizers are effective in decreasing the
brittleness and increasing the flexibility of dried films of the
interpolymers Accordingly in making water-base paints from the aqueous
interpolymer dispersions not only a dye or pigment, but also a
plasticizer, is usually added to the dispersion.
Most aromatic liquids, e g benzene, toluene, xylene or diphenyloxide
are effective as plasticizers for the interpolymers and can be
incorporated into and dispersed throughout the aqueous interpolymer
dispersion.
The emulsifying agents such for example as ammonium oleate, sodium
oleate, sulphonated sperm oil or higher alkyl aromatic sulphonates
which are conventionally employed in emulsion polymerizations to form
aqueous dispersions of polymeric materials, e.g of polystyrene,
polymethylmethacrylate, or styrene-butadiene copolymers are retained
in the polymer dispersions and modify the properties of the latter,
sometimes in ways not desired Variations in the kind, quality or s O 2
786,146 proportion of an emulsifying agent, as well as variations in
the other polymerization conditions, frequently affect the properties
and utility of a polymer dispersion Also, the emulsifying agents
frequently cause foaming of the emulsions Accordingly, careful control

is required in carrying out the conventional emulsion polymerization
reactions in order to operate satisfactorily and obtain polymer
dispersions of consistent and desired quality.
Although aqueous dispersions of the interpolymers of the invention can
be prepared by polymerizing an aqueous mixture of the corresponding
monomeric compounds in the presence of an added emulsifying agent, the
latter affects the properties of the resulting interpolymer dispersion
in ways similar to those described above and its presence often is not
desired The interpolymer dispersions of the invention are unusual in
that they can be prepared from aqueous mixtures, i e not uniform
emulsions, comprising substantially water-insoluble, non-ionizable,
liquid vinyl aromatic compounds and water-soluble alkali metal salts
of vinyl aromatic sulphonates in the absence of added emulsifying
agents The invention pertains to the aqueous dispersions of such
interpolymers prepared either in the presence or absence of an added
emulsifier, but is concerned particularly with the aqueous
interpolymer dispersions prepared in the absence of added emulsifying
agents and free of added emulsifiers.
Any non-ionizable liquid vinyl aromatic compound, or mixture of two or
more of such compounds, can be used in preparing the aqueous
interpolymer dispersions of the invention Examples of suitable
non-ionizable vinyl aromatic compounds are styrene, ar-vinyltoluene,
ar-vinylxylene, ar-chlorostyrene, ardichlorostyrene, and
ar-ethylvinylbenzene The non-ionizable vinyl aromatic compounds are
almost completely insoluble in water and in other aqueous media not
containing an emulsifying agent.
A water-soluble salt of a vinyl aromatic sulphonic acid, or a mixture
of two or more water-soluble salts of vinyl aromatic sulphonic acids,
can be employed in making the aqueous interpolymer dispersions
Examples of suitable vinyl aromatic sulphonates are sodium styrene
sulphonate, potassium styrene sulphonate, calcium styrene sulphonate,
barium styrene sulphonate, sodium ar-vinyltoluene sulphonate,
potassium ar-vinyltoluene sulphonate, sodium ar-chlorostyrene
sulphonate, potassium ar-chlorostyrene sulphonate, sodium
ar-vinylxylene sulphonate, and potassium arvinylxylene sulphonate The
alkali metal monovinyl aromatic sulphonates, especially sodium
monovinyl aromatic sulphonates, are preferred.
The polymerization mixture comprises one or more of the non-ionizable
vinyl aromatic compounds, a smaller amount by weight of one or more of
the water-soluble salts of vinyl aromatic sulphonic acids, a
polymerization catalyst, and at least sufficient water to dissolve the
vinyl aromatic sulphonate The water may be present in as large a
proportion as 70 desired The polymerizable starting materials are in
relative proportions of from 55 to 99 parts by weight of one or more

of the nonionizable vinyl aromatic compounds and from 1 to 45 parts of
one or more of the above 75 mentioned vinyl aromatic sulphonates In
one preferred form of the present invention from to 97 parts by weight
of vinyl aromatic compound is employed with from 3 to 40 parts by
weight of vinyl aromatic sulphonate 80 Alternatively, 85 to 97 parts
of vinyl aromatic compound and 3 to 15 parts of the sulphonate may be
used Use of the vinyl aromatic sulphonate starting material in
proportions larger than just stated often results in formation of 85
an aqueous solution, rather than a colloidal dispersion, of the
interpolymer product.
Although the polymerization mixture comprises the several starting
materials just mentioned, a mnixture consisting only of said start 90
ikg materials cannot satisfactorily be employed to make the aqueous
interpolymer dispersions of the invention A mixture consisting only of
the above-stated starting materials comprises twyo phases, i e an
aqueous solution of the 95 vinyl aromatic sulphonate and a separate
phase of the insoluble, non-ionizablev vinyl aromatic compound The
monomwric vinyl aromatic sulphonate has very little, if any, action as
an emulsifier for the non-ionizable vinyl aromatic l OC compound When
a mixture; consisting of said starting materials is stirred and
heated, separate polymerization reactions apparently occur in the two
phases of the mixture and, of the non-ionizable vinyl aromnatic
compound 105 which reacts, a major portion forms an insoluble and
undispersed mass or body of polymer.
An emulsifying agent, e g sodium oleate or sulphonated sperm oil, can
be added to a mix 11 ( ture of the above-mmntioned starting materials
and the resulting mixture stirred and reacted to obtain a
substantially uniform aqueous dispersion of the interpolvmer product
However, the aqueous interpolymer -dispersions thus 115 obtained
comprise the added emulsifying agent and are modified in properties by
its presence.
Furthermore, such employment of an added emulsifying agent involves
the operating difficulties hereinbefore mentioned Although such 12 C a
procedure for making the dispersions, and the dispersions thus
prepared, are within the scope of the' inventioin, the aqueous
interpolymer dispersions are preferably prepared in the absence of
added emulsifying agents as 12.
hereinafter described.
It has been found that the presence of a small proportion of a soluble
and highly ionized inorganic compound in the aforementioned aqueous
mixtures of a non-ionized 13 C 786,146 786,146 vinyl aromatic compound
and a water-soluble salt of vinyl aromatic sulphonic acid has an
effect of promoting interpolymerization of the two kinds of vinyl
aromatic compounds and formation of an aqu ous dispersion of the

interpolymer product and, as, a conlseaquence, of reducing in amount,
or preventing, formation of an insoluble, undispersed pelymer product
Thee aqueous, starting mixtures containing a minor amount of a
water-soluble, ionizable inorganic compound comprise two' phases and
are similar in appearance to, the mdxtures not containing such
inorganic compound It is believed that the soluble, ionizable
inorganic compounds cause a slight increase in solubility of the
non-ionized vinyl aromatic compound in the aqueous phase of the
reaction mixture; that they also serve as directional catalysts for
occurrence of a copolymerization reaction between the two kinds of
vinyl aromatic compounds; and that the copolymer is formed as
dispersed colloidal particles that have an emulsiying action for
water-insoluble organic material present, e g an emulsifying action,
during and prior to completion of the polymnerization, for a
considerable amount of the non-ionizable vinyl aromatic reactant and
for at least part of any homo,-poylmer thereof which may be fored
However, the invention is not limited by this, or any other theory, in
explanation of the results which are obtained.
Any of a wide variety of water-soluble, highly ionized inorganic
compounds, e g having ionization, constants greater than 1 (h' at 25
C, can be used in small amount to promote, or catalyze, formation of
the interpolymer in colloidal dispersed form Exceptions are inorganic
compounds such as sodium nitrite or potassium nitrite, which are
inhlibitors for the polymerization reaction, and inorganic compounds,
e g soluble heavy metal salts, which react with one or both of the
vinyl aromatic reactants, especially the vinyl aromatic sulphonate, or
with the interpolymer product, to form a water-insoluble precipitate.
Inorganic compounds reactive to' formr such a precipitate have not, as
yet, been encountered, but they may exist Examples of suitable
watersoluble ionizable inorganic compounds are sodium chloride,
sodiumi bromide, sodium sulphate, potassium chloride, potassium
bremide, potassium sulphate, calcium chloride, calcium bromide, barium
chloride and barium bromide The inorganic salts of polyvalent metals,
e g calcium chloride or calcium bromide, cause formation of an
interpolymer dispersion which is more viscous than that obtained by
use of an alkali metal salt such as sodium chloride, sodium bromide,
or potassium bromide under otherwise similar polymerization
conditions.
The water-soluble ionizable inorganic compounds are usually employed
in small proportion, e g in amount corresponding to between 0 03 and 1
per cent of the entire reaction mixture, the preferred proportion
varying somewhat with change in the kind of inorganic conepound
employed Proportions' of the ionizable inorganic compounds even
smaller than just stated are sometimes effective Mixtures of two' 70

or more water-soluble, ionizable inorganic compounds which are not
reactive with one another' to' form an insoluble precipitate, e g a
mixture of sodium bromide and sodium sulphate or of potassium bromide
and potassium 75 sulphate, can be used The alkali metal vinyl aromatic
sulphonates which are employed as reactants in, the process of the
invention are produced by a method which results in formation of an
alkali, metal halide, e g a chloride or 80 bromide of sodium or
potassium, and in some instances in formation of a corresponding
alkali metal sulphate together therewith These inorganic salts,
especially the alkali metal halides; and monre particularly sodium or
potassium 85 bromide, are conveniently used for the purpose of the
invention and are preferred The alkali metal chlorides or bromides are
usually employed in amount corresponding to from 0.03 to 10,
preferably from 0 05 to 0 5, per 90 centof 'the weight of the entire
reaction mixture, but they can be used in larger proportions.
An aqueous interpolymer dispersion can be formed by stirring, or
otherwise agitating, the 95 mixture at a reaction temperature in the
presence or absence of a piolymnerization catalyst, but the
interpolymerization reaction occurs most readily, rapidly, and
satisfactorily when a catalyst is employed The catalyst can; 100 be a
water-soluble, inorganic peroxy compound such as hydrogen peroxide,
sodium persulphate, potassium persulphate, or ammonium persulphate but
preferably comprises a mixture of such water-soluble catalyst 105 and
an oil-socluibile catalyst, i e a catalyst which is more soluble in a
non-ionizable vinyl aromatic compound such as styrene than in water
Examples, of suitable oil-soluble catalysts are organic peroxy
compounds such 110 as lauroyl peroxide, lienzoyl peroxide, and
tertiary-butyl peroxide The oil-soluble organic peroxides, when used
alone, have not been satisfactory in that they caused formation of a
large amount of insoluble, undispersed poly 115 meric material
Mixtures, of from 1 part by weight of one or more water-soluble
inorganic peroxides per 7 parts of one or more oilsoluble organic
peroxides to 7 parts of the inorganic peroxide per 1 part of organic
per 120 oxide have been satisfactory Regardless of whether the
catalyst be a water-soluble in,organic peroxide or a mixture of the
same and an organic peroxide, it is used in only small proportion, e g
in amount corresponding to 125 between 0 1 and 1, preferably from' 0
12 to 0 5, per cent of the combined weight of the same and the water
present in the reaction mixture.
A mixture of the aforementioned starting materials in the proportions
given above is 130 4 786,146 stirred or otherwise agitated, preferably
in a closed vessel or in contact with an inert gas such as nitrogen,
while at a reaction temperature The interpolymerization reaction can
ba carried out at from rcom temperature or thereabout to the boiling

temperature of the reaction mixture It is usually accomplished by
heating the mixture at temperatures in a range of from 40 to 1000 C
The polymerization usually is continued until the reaction is
substantially complete, but it can be terminated short of this point
and the unconsumed portion of the palymnrrizable starting materials be
vaporized from the resulting mixture Under is the preferred reaction
conditions hereinbefore described, the product usually consists
entirely of an aqueous colloidal solution, or dispersions of the
interpolymer product However, the reacted mixtures sometimes contain a
minor amount of insoluble, undispersed polymeric material that can be
removed, e g by filtering or decanting, from the aqueous polymer
dispersion that is formed as the major product.
The abovedescribed method permits production of exceptionally
concentrated aqueous dispersions of the interpolymer products, e g.
dispersions containing up to 72 per cent by weight of the colloidal
polymeric product In some instances, the concentrated polymer
dispersions are non-flowable, paste-like, or solid materials at roami
temperature However, they can be stirred together with water to obtain
flowable aqueous polymer dispersions of lower concentrations
Alternatively, polymer dispersions of as low a concentration as
described can be formed directly by the method of the invention Thus,
the invention permits direct production of the aqueous interpolymer
dispersions in a highly concentrated form which is convenient for
storage or shipment and which can, when desired, be diluted with
water.
The aqueous interpolymer dispersions of the invention are unusually
stable against coagulation by acids, alkalies, or inorganic salts For
instance, they can be treated with an acid or base to bring them to p
H values of from 2 to 9, or they can be admixed with a considerable
amount of an aqueous solution of an inorganic salt such as calcium
chloride, without coagulation occurring.
Following is a description by way of example of methods of carrying
the invention into effect.
EXAMPLE 1.
This example illustrates the importance of having a small amount of a
water-soluble, ionizable inorganic compound present in the aqueous
polymerization mixture when not employing an added emulsifying agent
In each of a series of experinments, a non-homogeneous starting
mixture, comprising 60 parts by weight of wvater, 38 parts of styrene,
2 parts of sodium styrene sulphonate (H 2 C = CHCQH 15 O Na), 1.235
parts of benzoyl peroxide, and the parts by weight of sodium
persulphate stated in the following table, was heated with agitation
in a closed container at 80 G for 16 hours.
Certain) of the starting mixtures were of the composition just stat d

Each of the other starting mixtures was of similar composition, except
that it also contained the percentage by weight of sodiumn chloride or
sodiuml bromide stated in the table After being heated, as described
above, each mixture was examined to determine whether a substantially
uniform aqueous polymer dispersion, i e colloidal solution, had been
formed The sizes, i e.
diameters, of the colloidal polymenr particles in certain of the
dispersions were determined.
The table gives the results which were obtained in each experiment The
proportions of certain of the starting materials given in the table
are expressed as the parts by weight of such material in a mixture
which otherwise has the composition given above.
786,146 786,146 TABLE I
Starting Mixture Comprises: Results Polymer Run Na 2 SO 8 Na CI Na Br
Dispersion Polymer Particle No pts -pts pts Formed as Size in
Dispersion the Product mu.
1 0 12 0 0 No 2 0 12 0 0 No 3 0 12 0 0 No 4 0 12 0 05 O Yes not
determined 0 12 0 10 0 Yes,.
6 0 12 0 0 027 Yes 0 17 -0 21 7 0 12 0 0 050 Yes 0 17 8 0 12 0 0 125
Yes 0 17 9 0 12 0 0 250 Yes 0 17 0 12 0 0 375 Yes 0 17 11 0 12 0 0 500
Yes 0 17-0 18 12 0 06 0 0 130 Yes not determined The mixture employed
in runs 1 to 3 reacted to form a mass of granules of an insoluble
polymer, apparently polystyrene All of the other mixtures reacted to
form stable colloidal solutions, of an interpolymner of styrene and
sodium styrene sulphonate.
EXAMPLE 2.
A mixture of 84 parts by weight of water, 55 44 parts of styrene, O
580 parts of sodium styrene sulphonate containing a minor amount
(probably about 0 3 weight per cent) of sodium bromide, and 0336 part
of sodium persulphate was heated at 650 C and agitated in a closed
vessel for 24 hours A uniform aqueous colloidal solution of an
interpolymer of styrene and sodium styrene sulphonate was thereby
obtained Although this experiment demonstrates that a colloidal soluti
Qn of the interpolymner can be obtainedi by use of a watersoluble
inorganic perody comnound as theo only catalyst, best results are
usually obtained by use of a mixture of a water-soluble inorganic
peroxide and an oil-soluble organic peroxide as the catalyst.
EXAMPLE 3.
In each of spirrals experiments, a mixture of water, styrene, sodiumr
styrene sulphonate, sodium persulphate and benzoyl peroxide in the
relative proportions given, as parts by weight, in Table 1 I was
heated to 950 C and agitated in a closed vessel for 16 hours The
sodiumi styrene sulphonate starting material was of the quality
employed in, Example 2, i e.

it contained about 0 3 per cent by weight of sodium bromide Ini each
experiment, an aqueous; colloidal solution, i e a dispersion, of an
interpolymer of styrene and sodium' styrene sulphonate was obtained'
In the following table, giving the compositions of the several
starting mixtures, styrene is abbreviated as " S," sodium styrene
sulphonate as " Na SS " and benzoyl peroxide is abbreviated as "BPO "
786,146 TABLE II
Starting Mixture Run No H 20 S Na SS Na 253 08 BPO pts pts pts pts
pts.
1 84 53 2 2 9 0 168 0 168 2 84 53 2 2 90 0 252 0 084 3 84 53 2 2 9 0
084 0 252 4 84 53 2 2 9 0 042 0 042 84 53 2 2 9 0 042 0 294 6 42 98 0
3 9 0 196 0 196 The aqueous interpolymer dispersions obtained in runs
1 to 5 were liquid and flowable at roomp temperature That obtained in
run 6 was a non-flowable paste at room temperature, which paste can be
thinned with water to render it flowable.
EXAMPLE 4.
A mixture of 84 parts by weight of water, 53 2 parts of styrene, 2 9
parts of sodium styrene sulphonate which contained about 0 3 per cent
by weight of sodium bromide as an impurity, 0 336 parts of sodium
persulphate, and O 56 parts of a sodium; capryl phosphate which is
effective as an emulsifying agent, was heated with agitation at 950 C
for 16 hours.
A viscous aqueous interp-olymer dispersion was thereby obtained.
EXAMPLE 5.
In each of a number of experiments, a mixture of the several starting
materials indicated in the following table, in the relative
proportions given, was heated with agitation in a closed container to
the temperature and for the time stated in the table Each of the metal
vinyl aromatic sulphonates named in the table contained an appreciable
amount, i e 0 3 weight per c-nt or more, of the corresponding metal
breimide as an impurity The table gives the proportion of each
starting material as parts by weight In the table, calcium styrene
sulphonate is abbreviated as " Ca SS," arvinyltaluene is abbreviated
as " VT," o-chlorolstyrene is abbreviated as " C-S,"
2,5-dichlorostyrene is abbreviated as "CL 2-S," and lauroyl peroxide
is abbreviated as " LPO " Other abbreviations are similar to those
employed in preceding examples.
TABLE III
Starting Mixture Reaction Conditions T Non-Ionizable Vinyl H
20-Soluble Oil-Soluble Vinyl Aromatic Aromatic Inorganic Catalyst Run
H 20 Reactant Sulphonate Catalyst Time Temp.
No pts hrs,c C.
Kind Pts Kind Pts Kind Pts Kind Pts.
1 15 VT 9 5 Na SS 0 518 Na 252 08 0 03 BPO 0 03 16 75 2 15 Cl-S 16 0

Na SS 0 518 Na 252 08 0 03 BPO 0 03 16 75 3 15 C 12-S 7 11 Na SS 2 89
Na 25208 0 03 BPO 0 03 17 80 4 15 S S 9 5 Na SS 0 518 Na 252 08 0 03
LPO 0 03 16 75 | 15 S 9 5 Na SS 0 518 H 20 O 03 BPO 0 03 16 75 + Fe(N
03)2 6 17 5 S 7 13 Ca SS O 872 Na 25208 0 035 BPO 0 035 16 75 7 200 S
200 Na SS 2 Na 2 S O 8 0 5 BPO 0 5 3 80 Approximately 0 00015 parts by
weight of Fe(N 03)2 used per part of the H 202.
All of the above mixtures reacted to, form aqueous colloidal solutions
of the interpolymner products In each of the runs 3 and 5, a small
amount of insoluble, undispersed polymer was also, found.
EXAMPLE 6.
Several aqueous colloidal solutions of interpolymers of styrene and
sodium styrene sulphonate were tested for stability against
coagulation by freezing and thawing and also by treatmnent with an
aqueous calcium chloride solution Each of the colloidal solutions, i
e.
aqueous polymer dispersions,, was, prepared in the absence of added
emulsifying agents by the method illustrated in the preceding
examples.
Each dispersion contained approximately 40 per cent by weight of the
interpolymer The dispersions differed from one another asi regards the
proportions of sodium styrene sulphonate chemically combined in the
interpolymer One of the dispersions was initially formed as) a thick
paste and was thereafter diluted with water to bring it to the
concentration stated above The others were prepared directly as
interpolymer dispersions of said concentration A portion of each
interpolymer dispersion was frozen and thawed to determine whether the
polymer is coagulated In the instances in which coagulation did not
occur, the freezing and thawing operations were repeated Certain of
the dispersions were frozen and thawed four times without becoming
coagulated An aqueous 20 per cent by weight calcium chloride solution,
was added gradually and in measured amount to a separate 15 ml portion
of each of the aqueous interpolymer vl 00 s Qu dispersions while
stirring the resulting mixture weight of chemically combined sodium
styrene at room temperature, and the volume of the sulphonate in the
interpolymer ingredient of calcium chloride solution required to cause
each dispersion It also gives the results of the coagulation of the
interpolymer was deter tests which were carried out.
mined Table IV gives the percentage by TABLE IV
Stability of Dispersion Freeze-Thaw Test Ca C 12 Test % Na SS Run in
Inter No of Ml of No polymer Times Result 20 % Ca C 12 Result Frozen
So Pn added 1 0 5 1 coagulated 0 2 coagulated 2 1 0 1,, 0 5,, 3 2 0
1,, 10 0 not coagulated 4 3 8 4 not 10 0 not coagulated coagulated 5 0
4 not 10 0 not coagulated coagulated -polymer dispersion was formed as
a concentrated paste and was thinned to 40 % concentration with water.

As is evident from the table, the dispersions of interpolymers of
styrene with 3 per cent or more of sodium, styrene sulphonate are more
stable than the dispersions of the interpolymer containing smaller
proportions of sodium styrene sulphonate.
EXAMPLE 7.
A mixture of 750 grams of water, 79 grams of sodium styrene sulphonate
which was of 95 per cent purity and contained sodium bromide together
therewith, 425 grams of styrene, 2 5 grams of sodium persulphate, and
2 5 grams of benzoyl peroxide was heated with stirring at to 85 C in a
flask provided with a reflux condenser while bubbling nitrogen through
the mixture to maintain an atmosphere of nitrogen in contact therewith
The mixture was stirred and heated at atmospheric pressure under the
above conditions for 3 hours The styrene and sodium styrene sulphonate
were thereby interpolymerized and a fairly viscous colloidal solution
of the interpolymer was obtained.
Ex AMPLE 8.
In each of two experiments a mixture of water, styrene, sodium styrene
sulphonate (which was of 93 per cent purity and contained sodium
bromide together therewith), sodium persulphate and benzoyl peroxide
was agitated and heated in a closed vessel at 80 C for 5 hours,
whereby an aqueous colloidal solution of an interpolymer of styrene
and sodium styrene sulphonate was formed Each of the starting mixtures
contained 18 parts by weight of water, 0 09 part of sodium
persulphate, and 0.09 part of benzoyl peroxide One of the starting
mixtures contained 6 6 parts by weight of styrene and 5 7 parts of
sodium styrene sulphonate of the above-stated quality The other
starting, mixture contained 7 2 parts of styreneand 5 2 parts of tho
sodium styrene sulphonate described above Accordingly, in one of the
experiments there was obtained an aqueous colloidal solution of an
-interpolymer of approximately 55 weight per cent styrene and per cent
sodium, styrene sulphonate, and in the other experiment there was
obtained a colloidal solution of an interpolymer of approximately 60
per cent styrene and 40 per cent sodium styrene sulphonate A portion
of each of the aqueous polymer dispersions thus prepared was spread as
a thin layer onl a supporting surface and dried A fairly brittle,
translucent film of the interpolymer was thereby formed Each of the
films was completely redispersed, as colloidal particles in water, by
shaking it together with water.
* Sitemap
* Accessibility
* Legal notice
* Terms of use

* 5.8.23.4; 93p
* GB786147 (A)
Description: GB786147 (A) ? 1957-11-13
Method and means of detecting flaws
Method and means of Detecting Flaws
We, MAGNAFLUX CORPORATION, of 7300 W.
Lawrence, Chicano, Illinois, United States of
America, a corporation organized and existing under the laws of the
State of Delaware,
United States of America, do hereby declare the invention, for which
we pray that a patent may Ibe granted to us, and the method by which
it is to be performed, to ibe particularly described in and; by the
following statement:-
This invention relates to a method and means for detecting flaws and
more particularly to a method and means of flaw detection by which; a
visual indication of flaws. in a test piece is obtained on a member
independent of the test piece.
According to this invention, a member having permanently uniformly
distrlbuted magnesizable material therein, preferably a sheet of
electrically insulating material having iron oxide particles dispersed
therein, is placed on a surface portion of the article to rbe tested
for flaws and! a magnetic flux is induced in the article. The magnetic
flux will be generally uniform over the surface portion of the article
excerpt as distorted by defects in the article and the flux pattern
over the surface portion will be transferred to the sheet by permanent
magnetization of the magrretizasble material therein. The sheet may
then be removed from the article and free particles of magnetizable
material are then placed. over the surface of the sheet. These
particles will be generally uniformly distributedi over the sheet
except portions of the sheet highly magnetized by the effect of flaws.
in the article tested for defects.

The particles will be attracted to such portions and bunched together
to provide a clear visual indication of flaws in the article tested.
This invention has the advantage of providing a permanent record of
flaws in the article In addition, the invention may be used to test
under surfaces and other relatively inaccessible surfaces of articles
for flaws. Moreover the invention is very efficient and provides a
much clearer indication of flaws than methods andi apparatus
previously used. Still further, the invention is highly efficient from
the standpoint of power and equipment because only a short impulse of
magnetization of the article to Ibe tested is necessary.
Another advantage is that magnetizable particles in the sheet are
fixed and only the strength and direction of magnetization affect
them. They are not free to migrate into areas of high field strength
and, hence, mask presence of cracks or other flaws.
According to a particular feature of this invention, means are
provided for inducing only a short impulse of flux in the article thus
permitting use of a power supply with a very low power capacity.
According to another feature of this invention, the ,thickness of the
test sheet is so related to ithe depth of flaws below the surface of
the article tested that optimum results are obtained.
A further feature of this invention is in the provision of a method
and means for testing the internal surfaces of pipes lor the like for
flaws.
Still another feature of this invention is in the provision of a plate
of magnetizZile material over the test member to !greatly increase the
magnetization of the material in the test member when the magnetic
flux is induced in the article to be tested.
This invention will be more fully understood from the following
detailed description taken in conjunction with the accompanying
drawings which illustrate preferred embodiments and' in which: -
Figure 1 is an isometric view of an article which may Ibe tested by
the method and means of this invention;
'Figure 2 is a crossrectional view taken substantially along lines
II--II of ig. 1 and illustrating flaws or defects in the article;
Figure 3 is an isometric view illustrating the article of 3Rigs. 1
andi 2 held in magnetizing apparatus of this invention with a test
member placed on a surface portion of the article;
Figure 4 is a view illustrating a test mem- er having free particles
of magnetizable material disposed on the surface thereof and
illustrating how a clear visual indication of flaws is obtained;
Figure 5 is a cross-sectional view taken substantially along lines V-V
of Fig. 4 and illustrating a preferred ccmposition of the test member;
Figure 6 is a view illustrating a tube-like test member placed inside
the pipe or the like so that the internal surface portion of the pipe

can be readily tested;
Figure 7 is a view illustrating a plate of magnetizable material
placed over the test member to enhance the magnetization thereof; and
Figure 8 is a view illustrating another preferred method and means for
giving a visual indication of the flux distribution in the test member
so as to indicate flaws or defects in the article tested.
Preference numeral 10 designates an article which may be tested by the
method and means of this invention. The article 10 to be tested may be
of any electrically conductive material whether magnetic or
non-magnetic but the method and means of this invention are peculiarly
and particularly advantageous with test articles of magnetizable
material such as iron or steel. The cross-sectional view of
Fig. 2 illustrates flaws or defects 11 and 12 in the test article 10.
The method and apparatus of this invention are used to give a clear
permanent record and indication of such flaws or defects.
In Fig. 3, the article 10 is held between a pair of supports 13 and 14
which may be adjustable supported on a frame 15. A member 16 of
uniformly distributed maenetizable material is placed over a surface
portion of the test article 10 and a magnetic flux is induced in the
test article 10 to uniformly magnetize the material in the member 16
except as distorted by flaws or defects such as the flaws 11 and 12 in
the article 10.
It will be understood that anv method of or means for inducing the
magnetic flux in the article 10 might be used such as a steady direct
current conducted therethrough, a permanent magnet or a coil energized
from a source of direct current A preferred and peculiarly
advantageous method and means is illustrated in Fig. 3, in which the
support 13 is connected through a switch 17 to one side of a capacitor
18 with the support 14 connected to the other terminal of the
capacitor 18. The capacitor 18 mav be slowly charged up through a
resistor 19 from a source of high D-C voltage connected to the
terminals 20 and 21.
After the capacitor 18 is charged up, the switch 17 may be closed to
provide a short impulse of very high current which will flow between
the contacts 13 and 14 through the article 10 and induce a high
instantaneous flux in the article 10. This flux will uniformly
magnetize the material in the test member 16 except as distorted due
to the presence of flaws or defects in the test article 10. It will be
apparent that this method and means for providing the flux is highly
advantageous since the charging period for the capacitor 18 may he
very long compared with the discharge period and the source of power
connected to the terminals 20 and 21 need supply only a very small
average current
It will be understood that means other than the arrangement above

described may be used to induce a short impulse of high flux in the
article 10 while conserving on size and power capacity of apparatus
required.
In combination with a unidirectional magnetizing flux, an alternating
biasing flux may be used to achieve a magnetization of the member 16
more closely alike the internal structure of the article 10. Again,
this may be accomplished in any desired manner, one method being
illustrated in Figure 3 in which a source of alternating current 22 is
connected in series between one side of the capacitor 18 and the
support 14. Upon closing of the swkch 1.7, an alternating current from
source 22 will be superposed on a unidirectional current from the
capacitor 18. A pulsating direct current might also be used. It will
be apparent that the arrangement of Figure 3, however, is highly
advantageous in achieving optimum results with a minimum of equipment
necessarv.
After the member 16 is magnetized, it may he removed from the article
10 and free magnetizable particles such as powdered iron may-be
disposed over the surface porticn thereof. The particles will
uniformly distribute themselves over the test member 16 except that
they will be attracted to highly magnetized portions of the member 16
which had been over flairs or defects in the article 10 in the
magnetization step. The accumulation of particles over such portions
of the member 16 will provide a very clear visual indication of flaws
or defects as illustrated in Fig. 4.
The test member 16 may be of any composition in 'which magnetizable
material is generally uniformly distributed therein.
Greatly improved results are, however, obtained by the composition of
electrically insulating material with iron or iron oxide particles
embedded therein. --Plastic and the like materials are suitable while
elastomeric material such as rubber and the like are preferred since,
with a flexible sheet form, the member 16 may be readily disposed
against complex surfaces of articles tested.
A particular feature of the invention is that the member 16 may be
disposed against undersurfaces or other relatively inaccessible
surfaces of articles to be tested for flaws. The advantages of this
invention, in this respect, are readily apparent from Fig. 6 which
illustrates a member 23 in the form of a tube dis posed inside a pipe
24 for testing the pipe for flaws and. defects. In this case, the
member 23 is preferably iof an elastomeric material such as rubber
with magnetizable particles such as iron or iron oxide particles
dispersed therein.
The tube 213 may then have a diameter, in its unsexed condition, less
than the inside diameter of the pipe 24 to be tested, so that it ran
be readily disposed' inside the pipe, and then it may. be inflated by

compressed air, for example, so as to snugly engage the inner surface
of the pipe 24.. The tube 23 may then be deflated and removed from the
pipe after which iron particles may be dispersed thereon to indicate
flaws in the pipe.
According to another feature of this invention', the thickness of the
sheet member 16, or of the tube 23, is so related to the depth of
flaws tested for in the article 10 or pipe 24 that optimum results are
obtained. The disportion in flux distribution due to a defect in the
test article 10 or pipe 24 causes. opposite magnetic polarization of
the magnetizable particles or material; in the test members 16 or 23
spaced on opposite sides of the defect and, for a maximum of
magnetization of particles in the test members 16 or 23, it is
desirable that the magnetizable material or particles within the
members 16 or 23. form a complete flux path inside the same. It has
been found that the thickness of the test members 16 or 23 must be at
least 0.1 the depth lof the defect below the surface of the article 10
or 24 in order to give optimum results with a clear visual indication
of the defect.
As an alternative to, or in addition to, makw ing the thickness lof
the test member 16 proportionate to the ,dlepth of defect to be tested
for in the article 10 as described above, the arrangement of Fig. 7
may ibe used in which a plate member 25 of magnetizable material such
as iron is placed over the test member 16 to provide a good flux path
and effective magnetization of particles in the test member 16 so as
to insure a good indication of defects located at substantial depths
below the surface of the article 10.
Flux may be induced in the pipe 24 by the preferred apparatus and
method of Figure 3 or in any desired manner.
Another feature of this invention is illustrated in Fig. 8 in which a
container or pan 26 has a generally flat bottom 217 covered with a
liquid such as oil in which particles of magnetizable material, such
as iron are suspended. The pan 26 is placed over the test member 1.6
and the particles suspended in the liquid 2 8 may move freely and
accumulate over highly magnetized portions of the memher 1i6 to give a
clear visual indication of defects. In this manner, the pan 26 may be
used over and over again, eliminating the necessity of dispersing or
dusting particles over the member 16 for each test.
It wlli be apparent that this invention is highly advantageous in
providing a very clear indication of flaws in articles, a permanent
record of flaws in an article and an efficient test of relatively
inaccessible surfaces of articles with relative ease and with a
minimum in amount and! size of equipment.
It will also be understood that modifications and variations may be
effected without departing from. the invention.

What we claim is: -
1. A method of testing an article for defects, including the steps of
placing adjacent a surface of the article a member having a mag-
netizable material permanently uniformly distributes therein, and then
inducing in the article a magnetic flux which is substantially uniform
over the surface except as distorted due to defects in the article.
2. 'A method as claimed in claim 1 in which a unidirectional flux is
induced in the article.
3. A method as claimed in claim 21 in which an alternating ibiasing
flux is imposed on the unidirectional flux.
4. A method as claimed in claim 1, 2 or 3 in which the magnetic flux
is induced in a short impulse.
'Si. A method as claimed in claims 1, 2, 3 or 4 in which freely
movable magnetic particles are disposed on the member to show the flux
pattern in the member and indicate defects in the article.
6 A method as claimed in claim 5 in which the particles are suspended
in a liquid.
7. A method as claimed in claim 1, 2, 3, 4, 5 or 6 in which the
article is hollow and in which the member is tubular, the member being
inserted within the article.
8. A method. as claimed in claim 17 in which the member is expanded
within the article so as to 'firmly engage the inner surface thereof.
9. A method, as claimed in any preceding claim in which the magnetic
flux is induced in the article by the passage of electric current
through the article.
10. A method as claimed in claim 9 in which the electric current is
obtained by discharge of a capacitor through the article.
11. Apparatus comprising a member having a magnetizable material
permanently uniformly distributed therein and' adapted to be placed
against a surface of an article to be tested for defects, and means
for inducing in the article a magnetic flux which is substantially
uniform over the surface except as distorted due to defects n the
article.
12. Apparatus as. claimed in claim 11 ineluding particles of magnetic
material distributed over the member to show the flux pattern in the
member and indicate defects in the article.
13. Apparatus as claimed in claim 12 ineluding a container for
suspendiing the particles in a liquid and having a generally flat
bottom arranged to be disposed on the member.
* GB786148 (A)

Description: GB786148 (A) ? 1957-11-13
Insoluble resinous copolymers of (chloromethyl) styrene and polyvinyl
aromatic hydrocarbons and nitrogen-containing derivatives of the copolymers
A high quality text as facsimile in your desired language may be available
amongst the following family members:
DE1049097 (B) NL97922 (C)
DE1049097 (B) NL97922 (C) less
PATENT SPECIFICATION
786,148 Date of Application and filing Complete Specification: April
23, 1956.
No 12391156.
Application made in United States of America on May 9, 1955.
Complete Specification Published: Nov 13, 1957.
Index at acceptance:-Clas's 2 ( 6), P 5 (A:D 2 X:Fl:K 7), P 5 P 1 E(
1:2:3:5), P 5 P 2 A( 1:2:5), P 5 P( 2 X: 3: 5), P 5 T(IC: 2 D: 2 X), P
7 A, P 7 D 2 A( 1: 2 A: 2 B: 4), P 7 (D 3: F 1), P 7 K( 5: 8: 10), P 7
PIE( 1: 2: 3: 5), P 7 P 2 A( 1: 2: 5), P 7 P( 2 X: 3: 5), P 7 T( 1 C:
2 D: 2 X), P 8 A, P 8 D 2 (A: B 2), P 8 (F 1: K 7), P 8 PE( 1: 2: 3:
5), P 8 P 2 A( 1: 2:
5), P 8 P( 2 X:3:5), P 8 T(XC:2 D:2 X), PIO(A:D 1 A:F 1: K 7), P 1
OPIE( 1:2:
3: 5), P 1 OP 2 A( 1: 2: 5), Pl OP( 2 X: 3: 5), P 1 OT(l C: 2 D: 2 X).
International Classification:-CO 8 f.
Insoluble Resinous Copolymers of (Chloromethyl) Styrene and Polyvinyl

Aromatic Hydrocarbons and NitrogenContaining Derivatives of the
Copolymerg We, THE Dow CHEMICAL COMPANY, a Corporation organized and
existing under the Laws of the State of Delaware, United States of
America, of Midland, County of Midland, State of Michigan, United
States of America, do hereby declare the invention for which we pray
that a patent may be granted to us and the method by which it is to be
performed, to be particularly described in and by the following
statement:-
This invention relates to improvements in ion exchange materials It
pertains, more particularly to insoluble resinous copolymers of
(chlorowmethyl)styrene and polyvinyl aromatic hydrocarbons, and
nitrogen-containing derivatives of the copolymers which nitrogenous
compositions are suitable for' the removal of anions from fluids The
invention relates to a method of making the insoluble copolymers and
their nitrogenous derivatives.
United States Patent No 2,629,710 discloses the making of insoluble
resinous compositions containing reactive chlorine atoms by
chloromethylating insoluble cross-linked copolymers of styrene and
divinylbenaene, or copolymers of styrene, ethylvinylbenzene and
divinylbenzene, and teaches that the chloromethylated copolymers can
be converted to ion exchange resin by reaction with amines.
The patentee teaches it is desirable that as many chloromethyl groups
as possible be introduced into the insoluble copolymer because the
number of such groups' determines the number of polar groups that can
be introduced into the final product, and the number of polar groups
determines the capacity of the resin to absorb ions.
However, the number of chloromethyl groups that can be introduced into
the in.
soluble cross-linked vinyl aromatic copolymers is dependent in part
upon the degree of crosslinking, i e the proportion of divinvlbenzene
in the copolymer A copolymer having a low degree of cross-linking, say
containing one per cent by weight of chemically combined divinyl 45
benzene, can readily be chloromnethylated to form a product containing
an average of about one substituent chloromnethyl group per aromatic
nucleus, whereas a chloromethylated copolymer of a higher degree of
cross-linking, 50 say a copolymer of styrene cross-linked with ten per
cent by weight of divinylbenzene, contains a lesser number of
substituent chloromethyl groups per aromatic nucleus in the copolymner
It becomes more difficult to' intro 55 duce chloromethyl groups into,
the vinyl aromatic copolymer as the proportion of divinylbenzene in
the' copolymer is increased from to 20 per cent by weight or more.
The aforementioned U S Patent No 60 2,629,710 also teaches that by
varying the amount of divinylbenzene used in the preparation of the
copolymer, variations can be made in the physical properties of the

polymeric material which carry through to the final ion 65 exchange
material and which have a, marked effect upon its utility For most
purposes, copolymers in which the divinylbeuzene component varies from
0 5 to 8 per cent on a molar basis, are employed Copolymers made with
70 from 0 5 to 2 per cent of divinylbenzene give finished ion exchange
resins of low density and high porosity Denser resins of lower
porosity are obtained by increasing the percentage of divinyibenzene
in the copolymer to 75 from 4 to' 8 per cent.
It is apparent that the use of the insoluble resinous copolymers of
monovinyl aromatic hydrocarbons and polyvinyl aromatic hydrocarbons
which copolymers are chloromethyl 80 ated and are employed for the
manufacture of ion exchange resins having desirable characteristics,
is restricted not only to the employment of cross-linked copolymers
having a narrow range in the degree of cross-linking, e.g to from
about 2 to 8 per cent divinylbenzene on a molar basis, but is also
limited by the number of substituent chloromethyl radicals that can be
introduced into the crosslinked copolymers There is need of insoluble
resinous vinyl aromatic polymers containing reactive chlorine atoms
having a wider range in the degree of cross-linking, and capable of
being converted to insoluble ion exchange resins, e g quaternary
ammonium anion exchange resins having high capacity for absorbing
anions from fluids.
Among the characteristics which render an ion exchange material, e g a
quaternary amnmonium anion exchange resin, commercially attractive
are: ( 1) a high capacity for absorbing anions from fluids per unit
volume of a bed of the resin: ( 2) a uniform particle size; ( 3) a
good porosity to permit rapid absorption of anions fromi fluids; ( 4)
a high efficiency for regeneration of the resin; ( 5) a high
operating-capacity; ( 6) a high resistance to breaking, cracking, or
spalling of the resin.
particles; ( 7) a low loss in ion exchange capacity over long periods
of operation; and ( 8) a low volume change due to shrinkage or
swelling of the resin particles during rep rated cycles of operation
for the absorption of anions from a fluid and displacement of the
absorbed ions from the resin by treatment with a regenerant solution'
For most purposes a bed of an ion exchange resin should not undergo a
change in volume exceeding 20 per cent, under operating conditions,
and resins which exhibit a smaller change in velume under repeated
cycles of operation for the absorption of ions from fluids and
regeneration of the resin, are desired.
It has now been found that insoluble resinous cross-linked vinyl
aromatic copolymers which contain reactive chlorine atoms, and which
copolymers are capable of being converted to insoluble anion exchange
resins having among their prop erties the aforementioned

characteristics, can readily be obtained by polymerizing a mixture of
a major proportion on a molar basis of (chlerom'ethyl)styrene and a
minor proportion of a polyvinyl aromatic hydrocarbon, e g
divinylbcnzene.
St It has been found that copolymers of (chloromethyl)styrene and a
polyvinyl aromatic hydrocarbon, e g divinylbenzene, containing the
latter compound in a wide range of proportions, say from 2 to 20 per
cent or more on a molar basis, can be employed for making anion
exchange resins which exhibit to a greater or less extent the
aforementioned characteristics.
The anion exchange resins prepared from the insoluble resinous
cross-linked copolymers of (chloromiethyl)styrene and a polyvinyl
aromatic hydrocarbon, e g divinylbenzene, by reaction of the copolymer
in the form of small beads, spheres, or sphereids, with a tertiary
amine are surprisingly resistant to breaking, 70 cracking, or
spalling, both during the preparation of the anion exchange resin, and
in use of the latter for the absorption of anions from fluids The
resin particles appear to be relatively free from internal strains and
stresses 75 as compared to the product obtained by chloromethylating a
copolymer of styrene and divinylbenzene.
The copolymers of (chloromethyl)styrere and a polyvinyl aromatic
hydrocarbon, e g 80 divinylbtnzene, being free, or substantially free,
from internal strains and stresses are suitable for making anion
exchange resin in the form of relatively large particles, e g.
beads or spheroids of sizes between 10 and 85 mash per inch as
determined by U S.
Standard screens For some purposes anion exchange resins of such
relatively large particle sizes in the form of beads or spheres are
preferred, e g for removing complex metal 90 ions from aqueous
solutions, or from aqueous clay suspensions Attempts to prepare
strongly basic quaternary asnlmonium anion exchange resins in the fcrm
of beads or spheres of sizes between'10 and about 20 mesh per inch by
95 the heretofore known method of: introducing chloromethyl groups as
substituents on aromatic nuclei of an insoluble copolymer of styrene
and divinylbenzene, then reacting the chlorornethylat-d coprilyiner
with a tertiary 100 amine, results in the formation of a final product
wherein a major proportion, if not all, of the larger resin particles
are cracked or broken The miethod is not satisfactory for the
preparation of such anion exchange resins in 105 the form of beads or
spheroidal particles of sizes substantially larger than about 20 mesh
per inch.
The copolyeners of (chloromethyl)styrene and a polyvinyl aromatic
hydrocarbon contain 110 the chlorcm ethyl groups on different aromatic
nuclei in the copolymer molecule, and in most instances, contain a

substantially greater numher of chloromethyl groups per aromatic
nucleus in the copolymer, than have the in 115 soluble
chloromithylated vinyl aromatic polymers such as, chlorcmjethylated
polystyrene, or chloromezthvlat'ed copolymers of styrene and
divinylbeuzene croas-linked with a similar proportion of
divinylbenzene The copolymers of 120 (chlorcmethyl)styrene and a
polyvinyl aromatic hydrocarbon permit the introduction or substitution
of a greater number of polar groups, e.g quaternary ammonium groups,
in the copolymer molecule than has heretofore been 125 attained by
chloromethylating vinyl aromatic copolymers containing more than about
8 per cent on a molar basis of divinylbenzen The final product, i e
the anion exchange resins of the invention, have high capacity for the
re 130 786,148 786,148 3 moval of anions from fluids.
The invention provides new cross-linked vinyl aromatic polymers
containing chloromethyl radicals on aromatic nuclei in the copolymer
molecule which copolymers can readily be converted into anion exchange
resins having high capacity for the removal of anions from fluids and
having a greater degree of cross-linking and a wider range in the
degree of cross-linking than have anion exchange resins heretofore
prepared from chloromethylated vinyl aromatic polymers.
The (chloromethyl)styrene to be employed in making the copolymers is
preferably meta-, or piara-(chloromethyl)styrene However, any of the
isomeric ortho-, meta-, or para-(chloromethyl)s'tyrene, or mixtures of
the isomers can be used' The termi "(chloromethyl)styrene"' pertains
to the isomeric compounds of the formula CH, = CH CGH 4 CHCI.
The polyvinyl aromatic hydrocarbon to be employed as a cross-linking
agent in preparing the copolymers can be divinylbenzene,
divinyltoluene, divinylxylene, divinylethylbenzene,
divinylethyltoluene, or trivinylbenzene Divinylbenzene is the
preferred polyvinyl aromatic hydrocarbon It is usually obtained as a
liquid fraction consisting principally of divinylbenzene in admixture
with a minor proportion of ethylvinylbenzene The latter compound is of
no benefit as a crosslinking agent, but its presence in minor amount
is not disadvantageous The polymeric compositions, i e the copolymers
of the invention, may also, contain in chemically combined form a
small amount, e g 10 per cent by weight or less, of one or more other
polymerizable vinylidene compounds such as styrene, vinyltoluene,
vinvlxylene, ethylacrylate, methyl methacrylate, methyl iso p-r on
enyl ketone, vinyl chloride, or alpha-methyilstyrene.
The copolymers may contain from 0 5 to 50, preferably from 2 to 25,
per cent on a molar basis, of the polyvinyl aromatic hydrocarbon
chemically combined with fromi 99 5 to 50, preferably from 98 to 75,
per cent of the (chloromethyl)styrene.
The copolymers can be prepared in usual ways such as by polymerization

of a mixture of the monomers in mass or suspension in a liquid that is
not a solvent for the monomeric material Suspension polymerization',
in' which the monomers are first suspended in a liquid non-solvent for
the monomers such as glycerine, water, or brine and are then heated,
agitated and copolymerized, or in which the monomers' are scattered as
droplets throughout a thickened aqueous medium such as a suspension of
bentonite and water having a consistency sufficient to immobilize and
prevent the droplets from coalescing, and are then heated without
agitating and copolymerized, are preferred Such methods yield hard
copolymers in the form of small spheres, globules, spheroids, or
beads, and the size of the particles can be regulated and controlled.
The polymerization is usually carried out at temperatures between 20
and 110 C, and lower or higher polymerization temperatures can be
employed 70 The polymerization is accelerated by means of well known
catalysts which provide oxygen.
Examples of suitable catalysts are lauroyl peroxide, acetyl peroxide,
benzoyl peroxide, stearyl peroxide, di-tert -butyl peroxide, di 75
tert -butyl diperphthalate, tert -butyl perbenzoate, or cumene
hydroperoxide The catalysts are employed in amounts ranging from 0 1
to' 2 per cent by weight of the material to be copolymerized 80 The
copolymers are converted to ion exchange resins by reacting particles
of the insoluble copolymers with a nitrogen-containing base such as
ammonia, or a primary-, secondary-, or tertiary amine The reaction 85
can be carried out by adding the ammonia or amine to the copolymer
while the latter is suspended and agitated in a liquid which is a
solvent for the ammonia or amine, e g water, benzene, toluene,
chlorobenzene, or perchloro 90 ethylene The finely divided copolymer
can be suspended in liquid ammonia, or the liquid amine, in which case
no' other liquid need be used The mixture may be allowed to react at
room temperature, or preferably elevated tern 95 peratures, e g at
from 250 to 1200 C and at atmospheric or superatmospheric pressures.
The copolymer is usually swelled prior to its reaction with the
nitrogen-containing base by soaking the particles of the copolymer in
a 100 suitable liquid such as' benzene, toluene, chloroform, carbon
tetrachloride, methylene chloride or perchloroethylene at ordinary
templeratures or above.
The nitrogen-containing base to' be em 105 ployed in making the anion
exchange resins can be ammonia, or a primary-, secondary-, or tertiary
amine Examples of suitable amines are methylamine, ethylamine,
butylamine, dimethylamine, diethylamine, dipropylamine, 110
ethylenediamine, diethylenetriamine, trimethylamine, triethylamine,
tributylamine, dimethylethanolamine, methyldiethanolamine,
dimethylisopropanolamine, methyldiisopropanolamine,
benzyldimethylamine, diethylcyclohexylamine 115 or an alkylene

polyamine.
It may be mentioned that ammonia, or primary-, or secondary ammes form
weakly basic anion exchange resins containing amino groups, whereas
tertiary amines, e g trimethyl 120 amine or dimethylethanolamine, form
strongly basic quaternary ammonium anion exchange resins The latter
resins are capable of absorbing anions 'such as chloride, sulphate, or
hydroxyl ions from aqueous solutions, and 125 are preferred.
Following is a description by way of example of methods of carrying
the invention into effect, 786,148 EXAMPLE 1 (A) A mixture of 360
grams of (chloromethyl)styrene, 32 grams of divinylbenzene and 8 grams
of ethylvinylbenzene, together with 2 4 grams of benzoyl peroxide as
polymerization catalyst, was suspended in two litres of an aqueous
solution containing 480 grams of sodium chloride and 2 grams of methyl
cellulose ( 4000 cps) The mixture was stirred and heated at a
temperature of 65 C.
for one hour, then heated at 70 C with stirring for a period of 6
hours The Leopolymer was separated by filtering and was washed with
water and dried The copolymer was in the form of hard beads of sizes
between 20 and 50 mesh per inch as determined by U S.
Standard screens The copolymer beads contained 19 9 per cent by weight
of chlerinz by analysis.
(B) A charge of 17 3 grams ( 25 cc) of the copolymer beads prepared in
part (A) above was suspended in Frchlcro ethylene and heated at a
remperature of 80 G for one hour to swell the beads The swollen beads
were separated by filtering and were mixed with 334 grams of an
aqueous 25 per cent by weight solution of trimethylamine The mixture
was stirred and heated under reflux temperatures of up to 90 C for a
period of 4 hours The resin was separated by filtering and was washed
with water The wet resin, beads had a volume of 57 5 cc The beads were
in the form of an insoluble resinous quaternary ammonium chloride
composition The resin had an anion exchange capacity corresponding to
31 5 kilograins of calcium carbonate per cubic foot of a bed of the
water-wet resin beads.
EXAMPLE 2
A charge of 320 grams of para-(chloromethyl)styrene and 38 grams of a
liquid fraction consisting of 80 per cent by weight of' divinylbe
Gzene and about 20 per cent of ethylvinylbenzene, together with 2
grams of lauroyl peroxide as polymerization catalyst, was added to 125
cc of an aqueous solution of 99 91 per cent by weight of water, 0 03 p
r cent of a water-soluble condensation product of diethanolamine and
adipic acid, O 03 per cent of a water soluble reaction product of an
ethylene exide-urea condensation product with formaldehyde, and O 03
per cent of bentonite.
The mixture was vigorously stirred to disperse the monomer as droplets

in the aqueous medium Thereafter, there was added with gentle stirring
11 3 cc of an aqueous onz per cent by weight copper sulphate solution
and 480 cc of an aqueous 4 per cent by weight dispersion of bentonite
in water The resulting dispersion comprising the droplets of monomer
scattered throughout the thiclened aqueous medium was sealed in a
glass bottle and heated without agitating at a temperature of 500 C
for a period of 14 hours, then at 80 C for 6 hours, to polymerize the
monomers.
Thereafter, the copolymer was separated and was washed with water and
dried There was obtained 343 grams of copolymer in the form of beads
of sizes between 30 and 50 mesh per inch as determined by U S Standard
screens.
The copolymer contained 19 9 per cent by weight of chlorine A charge
of 325 grams of the copolymer was dispersed in liquid
perchloroethylene and heated at a temperature of C for one hour to
swell the beads The perchloroethylene was decanted and 1200 cc.
of an aqueous 25 per cent by weight solution of trimethylamine added
The mixture was stirred and heated gradually to a temperature of 900 C
for a pericd of about 0 5 hour, then heated at 900 C for 3 5 hours
longer The resin was separated, was washed with water, then with
acetone and again washed with water The resin had an anion exchange
capacity corresponding to 34 4 kilograms of calciumn carbonate per
cubic foot of a bed of the wet resin.
EXAMPLE 3
A copolymer of 87 7 per cent by weight of (chloromethyl)styrene, 9 8
per cent of divinyl 90 benzene and 2 5 per cent of ethylvinylbenzene
was prepared by a procedure similar to that described in Example 2 The
copolymer was in the form of rounded beads of sizes between and 60
mesh per inch A portion of the 95 copolymer was swelled in perchloro
ethylene and the swollen copolymer reacted with trimethylamine
employing procedure similar to that employed in Example 2 The resin
had an( anion exchange capacity corresponding to 100 33.7 kilograins
of calcium carbonate per cubic foot of a bed of the wet resin.
Another portion of the copolymer beads was swelled in
perchloroethylene and reacted with dimethyletharnlarm Inc by heating
the swollen 105 beads with an aqueous 60 per cent by weight
dimethylethanolamine solution at a temperature of 900 C for a period
of 4 hours The resin was separated, was washed with water, then with
acetone and again washed with 110 water The resin had an anion
exchange capacity corresponding to 36 2 kilograins of calciumi
carbonate per cubic foot of a bed of the wet resinr.
EXAMPLE 4 115
A charge of 80 grams of (chloromethyl)styrene ( 98 2 per cent) and 3 4
grams of a liquid fraction consisting of 97 per cent by weight of

divinylbenzene and 3 per cent cf dthylvinylbenzene, together with 0 42
gram of 120 lauroyl peroxide as catalyst, was polymerized employing
procedure similar to that described in Example 2 The copolymer was in
the formf of rounded beads of sizes from 20 to 50 mesh per inch The
copolvmenr was swelled in 125 percbloro ethylene, then mixed with 500
grams of ethylenediamine The mixture was stirred and heated at
temperatures between 880 and 1070 C over a period of 4 hours The resin
was separated and was washed with water It 130 786,148 with acetone
and again washed with water.
The product was an insoluble resinous quaternary amoniomum composition
containing trimethyl ammonium chloride groups of the 45 formula -CH 2
NCI(CH,), as substituents on aromatic nuclei of the copolymer It was
an anion exchange resin A weighed portion' of the product was dried by
heating the same at a temperature of 500 C at an absolute 50 pressure
of 10 millimetres; for a period of 3 hours It was then weighed to
determine the percentage of water in the resin granules A swelling
characteristic for the anion exchange resin was determined by
immersing a measured 55 volume of the dried anion exchange resin
granules in water for a period of one hour and thereafter measuring
the volume of the water-swollen resin particles The swelling
characteristic for the anion exchange resin was 60 calculated by
dividing the volume in cubic centimetres of the water-swollen resin
particles by the volume in cubic centimetres of the dry anion exchange
resin initially used An anion exchange capacity for the resin was,
also deter 65 mined The table identifies the copolymer by giving the
proportions of chloromethylstyrene and divinylbenzene employed in
preparing the same The table gives the percentage by weight of
chlorine in the copolymer and a 70 swelling ratio for the copolymer in
chloroform at 250 C The table gives the anion exchange capacity of the
final product in otilliequivalents; per gram of the dry resin, a
swelling ratio' for the chloride form of the anion 75 exchange resin
in water at 25 C and the percentage by weight of water in the swollen
resin granules The table also gives the anion exchange capacity in
kilograins of calcium carbonate per cubic foot of a bed of the water
80 immersed anion exchange resin.
was washed with a dilute aqueous solution of hydrochloric acid, was
washed with an aqueous l-normal sodium hydroxide solution and rinsed
with water until free from sodium hydroxide The resin had an anion
exchange capacity corresponding to 61 7 kilograins of calcium
carbonate per cubic foot of a bed of the wet resin.
EXAMPLE 5
In each of a series of experiments, a mixture of chleromethyl styrene
and a technical divinylbenzene similar to that described in Example 2,
in proportions as stated in the following Table was suspended in an

aqueous medium and polymerized employing procedure similar to that
described in Example 2 The copolymer was obtained in the form of
insoluble hard resinous particles of sizes between and 50 mesh per
inch as determined by U S Standard screens The percentage of chlorine
in the copolymer was determined by analysis A swelling characteristic
for the copolymer was determined by suspending a measured volume of
the dry copolymer particles in' chloroform at 250 C for a period of 2
hours and measuring the volume of the swollen beads The swelling
characteristic is, calculated by dividing the volume in cubic
centimetres of the swollen beads by the volume in cubic centimetres of
the dry beads.
Other portions of the dry copolymer were suspended in
perchloroethylene at a temperature of 80 C for one hour to swell the
beads,.
The perchloroethylene was drained from the swallen copolymer The
swollen copolymer was suspended in an aqueous 25 per cent by weight
solution of trimethylamine solution.
The mixture was heated at a temperature of 800 C in a closed container
for a period of 4 hours Thereafter, the resin was separated by
filtering and was washed with water, then 786,148 TABLE
Starting Materials Copolymer Product (Chloro Divinyl Swelling Capacity
Swelling Water Capacity Run Methyl) Benzene Chlorine Ratio meq /gm
Ratio in Kilogr.
No Styrene Wt % in (dry) in Resin Ca CO 3/ Wt % % CHC 13 H 20 % cu ft
(wet) 1 99 5 0 5 21 27 5 6 2 21 115 87 7 5 7 2 98 2 20 65 3 2 3 26 5
61 73 8 14 2 3 96 4 20 35 2 5 3 32 2 07 54 8 22 9 4 94 6 19 88 2 1 3
58 1 88 52 3 28 6 92 8 19 48 1 9 3 88 1 87 48 5 33 0 6 90 10 18 82 1 7
3 58 1 70 43 2 347 7 88 12 18 54 1 7 3 54 1 67 40 4 36 2 8 86 14 17 71
1 7 3 35 1 54 38 2 36 2 9 84 16 17 28 1 7 3 27 1 54 35 2 37 2 82 18 17
01 1 6 3 23 1 50 33 4 34 1 EXAMPLE 6
A charge of 20 grams of a, copolymer of 93 per cent chloromethyl
styrenel and 7 per cent divinylbenzene on a molar basis, in the form
of beads of sizes between 12 and 16 mesh per inch as determined by U S
Standard screens was suspended in perchloroethylene at 80 C.
and swelled The copolymer starting material contained 19 1 per cent by
weight of chlorine.
The excess perchloroethylene was drained from the beads A charge of
200 grams of an aqueous 25 per cent by weight solution of
trimethylamine was added The mixture was stirred and heated under
reflux at a temperature of 90 C for a period of one hour, then was
heated with stirring at 90 'C for three hours longer Thereafter, the
resin was separated by filtering, was washed with water, then with
acetone and again washed with water The product was an anion exchange
resin Ninetysix per cent of the water-swollen resin granules were in

the form of beads of sizes greater than 12 mesh per inch.
For purpose of comparison, a charge of 19 grams of a copolymer of 88
per cent styrene, per cent ethylvinylbenzene and 7 per cent
divinylbenzene on a molar basis, in the form of beads of sizes between
12 and 16 mesh per inch was placed in a glass reaction vessel equipped
with a reflux condenser and stirrer, together with 38 grams of
perchloroethylene.
Thereafter, 57 grams of chloromethyl methyl ether was added The
mixture was heated at a temperature of 550 C for one hour It was
stirred and 9 6 grams of anhydrous zinc chloride was added The
resulting mixture was f 0 a 9 ot stirred and heated at temperatures
between 540 and 570 C for 4 hours Thereafter, the copolymer was
separated and was washed and dried The chloromethylated copolymer
contained 15 03 per cent by weight of chlorine.
At this stage of the process the beads were net cracked or broken.
A charge of 10 grams of the chloromethylated copolymer beads was
suspended in perchloroethylene and swelled by heating the suspension
at a temperature of 600 C for one hour The perchloro ethylene was
drained from the beads and 200 grams of an aqueous 25 per cent by
weight solution of trimethylamine added This mixture was stirred and
heated under reflux at temperatures up to 900 C for a period of 4
hours The resin was separated and was washed with water It was; an
anion exchange resin All of the resin particles were cracked or broken
and were of sizes such that 96.3 per cent by volume of the
water-swollen particles passed through a 16 mesh per inch U.S Standard
screen.
* Sitemap
* Accessibility
* Legal notice
* Terms of use
* 5.8.23.4; 93p

Thermoplastic Compositions with Improved Light Stability

Recommended

Recommended

More Related Content

What's hot

What's hot (18)

Viewers also liked

Viewers also liked (19)

Similar to Thermoplastic Compositions with Improved Light Stability

Similar to Thermoplastic Compositions with Improved Light Stability (20)

More from Иван Иванов

More from Иван Иванов (20)

Recently uploaded

Recently uploaded (20)

Thermoplastic Compositions with Improved Light Stability