1. * GB785108 (A)
Description: GB785108 (A) ? 1957-10-23
Manufacture of hexahydrobenzylamine
Description of GB785108 (A)
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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
Manufacture of Hexahydrolienzylamine
We, J. R. GEIGY A.-G., a body corporate organised according to the
laws of Switzerland, of 215 Schwarzwaldallee, Basle,
Switzerland, 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 reduction of aromatic nitriles such as benzonitrile, tolunitrile
and benzyl cyanide, in the presence of---acetic acid anhydride to form
the corresponding acetylamino compounds is already known. The aromatic
nude-us -is not affected in this reaction (J. Am. Chem.Soc. 47, 3051
(1925)).
The reduction of 1 .4-dicyano-cyclohexane with platinum oxide in
acetic acid anhydride to form the corresponding diamine is also known.
In contrast to the above, it has now been found that
tetrahydrobenzonitrile can be hydrogenated with hydrogenation
catalysts in acetic acid anhydride while simultaneously saturating the
double linkage to give good yields of hexahydrobenzylamine. Instead of
the already known noble metal catalysts of the platinum oxide type,
other hydrogenating catalysts from the eighth group of the periodic
system can be used, such as finely distributed nickel or cobalt.
2. Advantageously the reaction is performed by dissolving
tetrahydrobenzonitrile in a mixture of glacial acetic acid and acetic
acid anhydride and, after the addition of the hydrogenation catalyst,
the mixture is treated with hydrogen in a pressure resistant vessel
while stirring at temperatures between 40 ad 100"C and at pressures
between 20 and 300 atm. Suitable hydrogenating catalysts are finely
distributed nickel, cobalt, palladium or platinum. Raney-nickel and
Raney-cobalt are particularly suitable. After evaporating off the
solvent and excess acetic acid anhydride, the reaction product is
saponified by boiling with hydrochloric acid.
The amine can be isolated from the hydro
chloride in the usual way by treating with
alkali. Yields of over 90% are obtained by
the process described.
The hexahydrobenzylamine can serve as
starting material for synthetic materials and
pharmaceutical products.
Example 1.
13.75 Parts of tetrahydrobenzonitrile are
dissolved in 150 parts of glacial acetic acid -and-50-parts of acetic
acid anhydride. After
the addition of 2 parts of Raney nickel, the
mixture is stirred in an autoclave at 50"C
under 100 atm. hydrogen pressure until the
pressure is constant. The reaction is com
plete after 3-5 hours.
After evaporating off the glacial acetic
acid and the excess acetic acid anhydride in
a vacuum, the remaining acetyl compound
of hexahydrobenzylamine is saponified at
the boil with concentrated hydrochloric
acid, the amine is liberated by the addition
of caustic soda lye and isolated by shaking
out with ether or by steam distillation. The
yield is 92% of the theoretical.
Also finely distributed cobalt, palladium
or platinum can be used as hydrogenation
catalyst instead of nickel.
Example 2.
10 Parts of Raney nickel are added to 117
parts of tetrahydrobenzonitrile and a mix
ture of 120 parts of acetic acid anhydride
and 85 parts of glacial acetic acid and the
whole is hydrogenated - at 75 C under 50
3. atm. hydrogen pressure until the pressure is
constant. After filtering off the catalyst, the
acetyl compound is distilled in a vacuum. It
passes over at 150-180 C under 10 mm
pressure. The yield is 85% of the theoretical.
After boiling 100 parts of the acetyl com
ponent with 1000 parts of a mixture of equal
parts of 15% sulphuric acid and 15% acetic
acid for 20 hours and adding an excess of
caustic soda solution, the amine can be extracted with ether and
recovered by distillation in a yield of more than 90%.
Example 3.
312 Parts of tetrahydrobenzonitrile with
500 parts of acetic-anhydride and 200 parts of glacial acetic acid are
hydrogenated in the presence of 15 parts of Raney nickel at 70-90"C :
while stirring until the pressure is constant at 10 atm. After
evaporating off the
solvent in a vacuum, the acetyl compound is distilled at 118-126 C
under 0.1 mm pressure. The yield is 97%.
After boiling 100 parts of the acetyl component with 1000 parts of a
mixture of equal parts of 15% sulphuric acid and 15% acetic acid for
20 hours and adding an excess of caustic soda solution, the amine can
be extracted with ether and recovered by distillation in a yield of
more than 90%.
Also Raney cobalt can be used as hydrogenation catalyst instead of
Raney nickel.
Example 4.
107 Parts of tetrahydrobenzonitrile are dissolved in 150 parts of
acetic-anhydride and hydrogenated in the presence of 7 parts of Raney
nickel at 70-90 until the pressure is constant at 100 atm. The
catalyst is filtered off and the solvent is evaporated off in a
vacuum, whereupon the acetyl compound passes over at 145-160"C under
10 mm pressure. The yield is 95%.
After boiling 100 parts of the acetyl component with 1000 parts of a
mixture of equal parts of 15% sulphuric acid and 15% acetic acid for
20 hours and adding an excess of caustic soda solution, the amine can
be extracted with ether and recovered by distillation in a yield of
more than 90%.
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* GB785109 (A)
Description: GB785109 (A) ? 1957-10-23
Improvements in tools having a pressure fluid driven rotary motor
Description of GB785109 (A)
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CH345971 (A) DE1055752 (B) FR1148593 (A) NL101232 (C)
US2855671 (A)
CH345971 (A) DE1055752 (B) FR1148593 (A) NL101232 (C)
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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.
SPECI 11 CATIO)
keprinted as amended in accordance with the Decision of the
Superintending Examiner, adting for the Comptroller-General dated the
fifteenth day of April 1958, under Section 29, of Athe Patents Act,
1949 -
PATENT' SPECIFICATION
785 109 Date of Application and filing Complete Specification: Feb 22,
1956.
No 5510156.
Application made in Sweden on March 23, 1955.
Complete Specification Published: Oct 3, 1957.
Index at acceptance:-Classes 60, DIDI, D 2 A( 17: 19: 21); 81 ( 2), A
5. 2 A; 83 ( 3), B 2 (AI: AS: V), E 1 (A 8 H 2: B 7 D: B 22), K( 3 C 5: 3
K: 7 D: 7 Q 2); and 110 ( 3), B 2 F 3, B 2 V( 3 A:
17: 20 C).
Internation Ai Classification:-A 61 c B 23 b, c B 24 b F Old.
COMPLETE SPECIFICATION'
Improvements in Tools having a Pressure Fluid Driven Rotary Motor We,
ATLAS Co Pco Ar TIEBOLAG, of Nacka, Sweden, a Company registered under
the Laws of Sweden, 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 tools having pressure fluid
driven rotary motors, such as grinding machines, drilling machines or
the like, and particularly dental machines One object of the
invention-is to provide a portable or hand tool which has low weight
and small dimensions and is easy to operate and which is particularly
fit for replacing conventional belt driven dental drilling machines A
further object of the invention is to provide a tool in which the
worlking implement, such as a dental burr or drill or grinding wheel
is driven by a high speed motor with a suitable number of revolutions
of the motor as well as of the working implement A still further
object of the invention is to provide a tool in which the rotation of
the working implement is immediately discontinued or is very quickly
braked when the pressure fluid supply is interrupted A still further
object of the invention is to provide a hand tool which is well
balanced and fits well in the hand of an operator, such as a dentist.
For these and other purposes we provide a tool having a rotary
pressure fluid driven motor with a housing and a rotor mounted -35 for
rotarion in said housing, yalve means in Pricf 3 s 6 d l said tool for
controlling the flow of fluid for driving the rotor, a motor shaft
mounted to rotate in the housing and carried through the rotor and
rotatable relative to the rotor, a hand-piece provided with means for
fitting a rotary working implement and for driving said implement from
said motor shaft, and bearings in the housing in which the rotor isl
mounted and which are provided one at eachi end of the rotor and
comprise sets of rolling bodies running on races, at least one of said
sets of rolling bodies running on an outer race with large diameter
and an inner race with a smaller diameter and being provided with and
cooperating with means for transmitting the rotary motion of said set
around the motor axis to the motor shaft, and each one of said sets
being arranged to roll on a race arranged for rotation with the rotor
and a second race provided in the housing, at least said second race
pertaining to the set of rolling bodies which transmits rotation to
the shaft being held against the rotation in the housing Further
characteristic features of the invention are set forth in the
6. following description of one embodiment of the invention and in the
claims.
In the accompanying drawing one embodiment of a tool according to the
invention for dental purposes is illustrated by way-of example Figs 1
and 2 are a longitudinal cross section of the tool and Fig 3 is a
section on line III-III in Fig 2.
The dental tool illustrated in the drawing is provided with a motor
housing comprising price 2 785,1 O a front section 1 and a rear
section 2 which the forward bearing is loaded or biased by is screw
threaded 'in th-fronit s&ction at 3 a spring 25 in the direction
towards the turThe front section 1 provides a socket 4 b ine wheel The
spring 25 -transmits axial accommodating a hose connection 5 through
pressure to the outer race 16 and is fitted which compressed air is
supplied to the tool between said race and the sleeve 23 which is 70
from a suitable source A compressed air also axially movable in the
motor housing driven rotor 6 is roiatably mounted in the section 1 A
rod 26 is slidable lengthwise of motor housing and consists of a
turbine the socket 4 and engages an inclined recess or nheel which is
supplied with driving air from slot 27 in the sleeve 23 and also
serves to 10:an annular admission chamber 7 in the front prevent the
sleeve 23 from turning in the 75 section 1 through nozzles 8 in a
partition 9 front section 1 around the longitudinal axis Instead of':
:turbine a sliding vane motor or of the tool Displacement of the
sleeve 23 in any other rotary air motor may naturally be the direction
towards the rear section 2 of employed The compressed air supply to
the the motor housing causes displacement of the admission chamber 7
is controlled by a rod 26 due to the shape of the inclined bottom 80
spring loaded ball valve 10 disposed in the of the recess 27 on which
the rod 26 rests.
socket 4 From the valve housing formed by Said displacement lifts the
valve 10 from its the hose connection 5 and the socket:4 a -seat -and
opens the air supply to the turbine.
passage 11 leads to the annular admission A hand-piece is detachably
inserted in the 120;chamber 7 The air flowing fromn the turbine' front
section 1 of the motor housing and in 85 : 'wheel 6 foiva Mito an
annular chamber 12 the illustrated embodiment said hand-piece and
'from there to the aitmosphere through consists of a substantially
tubular housing 30 openings 13 directed rearwards and arranged -which
fits into a bore in the motor housing in the rear section 2 of the
housing The section 1 and is retained in inserted position turbine
wheel 6 has axially extended hub by -a fiat circular spring loaded
ball lock 28 90 portions 14 fitted in ball bearings onai ach The
lousing 30 contains an intermediate side of the turbine wheel, These
ball bearings shaft 31 which is mounted in a ball bearing consist
7. of-inner races 15, outer races 16, sets 32 and-a needle bearing 33 The
intermediate of balls 17 and ball retainers 18 The outer,shaft is
provided with a claw coupling memrace 16 of the rear ball bearing is
press fitted ber 34 which is engageable with a claw coup 95 in tlie:
rear section 2 -:of-the-motor housing, ling member 35 fixed on the
shaft 20 The whereas the forward ball bearing has an coupling member
35 carries a brake cone 36 outer_ race A& 6 axially-movable in the
partition which cooperates with a corresponding brake 9 and keptfrom
turning by -an annular -disc cone 37 in the sleeve 23 A spring 38
keeps 19 _of:rubber or other -suitable flexible mater the intermediate
shaft: 31 in the position 100 iai L Amnotor-shaft 20 extends freely
through illustrated, in-the Figures.
a central bore-in-the turbine wheel 6 and the - A zfliat spring 39
which forms a resilient axia Lextensions 14 and is mounted for rota
bend is fitted in the housing 30 between an tionin-two ball-bearings
21 and 22 The-ball abutment 40 on the housing and an abut-40 bearing
21 is fitted in -the rear section 2 of ment 41 on the sleeve 23 When
the high 105 the motor housing, whereas the balt bearing portion of
the fiat spring 39 is pressed to22 is-fitte&din a sleeve 23 in the
front section wards the housing 30 the rear end of the 1 wlikh sleeve
is axially movable relative to spring 39 which:is guided in the
housing 30 te _ball bearing 22 -The ball retainers 18 moves the sleeve
23 towards the turbine f Armeans:rortransmitting rotary motion of
causing the old 26 to open the valve 10 and 110 the balls 17 _around
the turbine axis to the simu Itaneously the brake cone 37 to
disenshaft 20 ( For this purpose the ball retainers gage b rake cone
36 so -that the turbine 18 are connected -to the shaft 20 by means may
rotate and drive the-motor shaft 20 and of pins 24-
extending-transv-er-sely through -the the intermediate shaft: 31 An
increased presball retainers andthe-shaft In -view of-the sure on the
flat spring 39 produces an in 115 fact that the balls 17
rotate-around-the tur creased displacement of the sleeve 23 and bine
axis _which_ is -_the longitudinal axis of increased tensionfa of the
spring 25 which the tool _with a number of revolutions which increases
the -frictional contact between the is less than half the number
of-evolutions balls:17 and the races 15 and 16 so that an -: 5 5 of
the turbine _wheel:6 -thezballs function sub increased turbine torque
may be transmitted 120 stantially asthe planetary wheels-of -a plane
through the friction transmission.
tary friction gear the number of -revolutions ' -i Ttie intermediate
shaft 31 is provided with of the shaft 20 being less than half the
nuni a c Qhufick 45: screw threaded into the intermedhe Yt of
revolutions of the turbine wheel 6 ate shaft In the chuck a
cylindrical shank The abity Qfthe:ball retainers 18 to trans Qf a n Qt
8. illustrated working implement such 125 mit a:orque t the shaft 20
naturally te as a dentist's burr, a grinding wheel,
apolishpends-on:thefrictional contact-between the ing wheel or-other
working implement may balls 17 and the inner:races 15 and outer be
inserted The chuck 45 has an internal ra Ces 16 -I orfder to maintain
such frictional tapering portion at the rear end which taperco Utact
the axially;movable outer race 16 of in portion cooperates with an
external taper 130 ing portion 44 of an axially slotted clamping one
at each end of the rotor and comprise sets sleeve 43 which is fitted
in the bore 29 in of r 6 olling b 6 dies running on races, at least
the intermediate shaft 31 and serves to retain one of said sets of
rolling bodies running on the worldking implement In order to fix the
an outer race with larger- diameter and an working implement in the
chuck the shaft 20 inner race with smaller diameter and being 70 is
provided with a knob 46 at the: rear end provided with and cooperating
with means which extends from the rear section 2 by for transmitting
the rotary motion of said set means of which the shaft 20 and the
inter around the motor axis to the motor shaft, mediate shaft 31 -may
be turned manually and each-one of said sets, being arranged to
relative to the hand-piece -30 Furthermore, roll on a race arranged
for rotation with the 75 the hand-piece 30 with the bearing 32 is disc
rotor and a second race provided in the housplaceable on the
intermediate shaft 31 to ing, at least said second race pertaining to
the wards the motor housing 1, 2 and against the set of -rolling
bodies which transmits rotation action of the spring 38 Through
movement to he shaft being held against the rotation in of the
hand-piece 30 towards the motor hous the ihousing 80 ing ftom the
illustrated position, in which the 2 -A tool according to claim 1, in
which ball lock 28 engages an annular groove 47 in said motor shaft
extends through the rotor the hand-piece 30, claws 48 formed on the
and is free to rotate relative to the rotor arnd chuck 45 engage and
are retained by recesses relative to the housing, an intermediate
shaft 42 in the inner front end of the hand-piece mounted to rotate in
said handpiece, and a 85 30, In this position turning of the intermed
coupling between said shafts forming a drivfate shaft 31 by means of
the knob 46 causes ing connection between the shafts.
the chuck 45 to be threaded in or out of the 3 A tool according to
claim 2, in which a intermediate shaft 31 and when the chuck chuck is
provided in said hand-piece for 45 is threaded into the shaft 31 the
slotted receiving a shank of a working implement, a 90 clamping sleeve
43 is tightened since the portion of the motor shaft extending through
internal taper of the chuck 45 encloses the the rear end of the
housing and carrying a corresponding external taper 44 of the clamp
knob outside the housing, said knob serving ing sleeve 43 and tightens
9. said sleeve around to manually rotate the motor shaft and the the
shank of a tool (not illustrated) which is intermediate shaft in order
to operate said 95 inserted in the chuck and the clamping sleeve chuck
to engage or to release said shank, Loosening of the working tool
implement is respectively.
produced by turning the knob in the opposite 4 A tool according to
claim 1, in which direction braking means are provided for braking the
The dental tool above described rotation of said motor shaft, and
means are 100 and illustrated in the drawing should provided between
the working implement only be considered as an example receiving end
of said hand-piece and the rotor and the details of the invention for
operating said braking means to engage or may be modified in several
different ways disengage the braking means.
within the scope of the claims Instead of the 5 A tool according to
claim 4, in which 105 ball valve 10 controlling the pressure fluid
valve means are provided for controlling the supply to the rotor a
valve mechanism may flow of fluid for driving-the rotor, and in be
provided which controls the exhaust ports which said operating means
for the braking of the turbine or other motor The illustrated means is
cooperatively associated with said straight hand-piece may naturally
be replaced valve means to reduce the flow of fluid or fo 110 by an
angle type hand-piece as is conventional interrupt the flow of fluid
simultaneously in connection with dental tools The tool may with
engaging the braking means.
also be used for other than dental purposes 6 A tool according to
claim 1, in which for instance as a grinding or milling machine means
are provided for regulating the fricfor intricate jobs such as
manufacture of tional contact between the rolling bodies and 115
pressing or forging tools, artist's sculptural said races.
jobs, or the like 7 A tool having a rotary motor with a
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* GB785110 (A)
Description: GB785110 (A) ? 1957-10-23
10. Electron tube magnetic focusing device
Description of GB785110 (A)
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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.
PATENT SPECIFICATION
785, 110 c RI Date of Application and filing Complete Specification:
Feb 28, 1956.
No 6113/56.
Complete Specification Published: Oct 23, 1957 -
Index at acceptance:-Class 39 ( 1), D( 1 OD: 16 A 1: 46 A).
International Classification:-H Olj.
i COMPMETE SPECI'FI CATION Electron Tube Magnetic Focusing Device We,
STANDARD TELEPHONES AND 'CABLES LIMITED, a British Company, of
Connaught House, 63, Aldwych, London, W GC 2, England, do hereby
declare the invention, Communicated by Nippon Electric Company
Limited, a Japanese Gompany, of 2 Shiba Mita Shikoku Machie,
Mziaato-ku, Tokio, Japan,, for which we pray that,a patent may _be
granted to us, and the method by which it is to be performed, to be
particullarly described in and by ithe following statement: -
This invention relates tothe magnetic focusing devices for focusing a
long electron, beam and more particularly to such devices for use in
15 eleotron tubes, such as the travelling wave tube.
In electron tubes, such as travelling wave tubes and the like, axial
magnetic fields have been;used for maintainling the diameter of an
electron beam within an approximately fixed value over a long range In
such systems the magnetic field is not necessarily a uniform magnetic
11. field bt it is well known, that a magnetic field which varies in
magnitude somewhat in,the manner of a sine wave can be used to produce
periodic exact focusing and still mainwain the beam within limits of
the desired diameter.
(In a known form of the magnetic focusing arrangement there are
provided a plurality of annular permanent magnets arranged with like
poles faoing each other and with magnetic yokes extending radially
inward of the cylinder formed by these magnets into proximity mwith
the electron beam It is desirable that ithe magnetic yoke pieces
extend as close,as possible to the beam in order to exert the maximum
focusing control However, when they are brought into,close proximity
with the beam the electro-magnetic wave may excite the cavities
existing intermediate the yokes and thus induce unwanted effects which
may adversely d'stort the energy being,amplified or the electron beam
itself.
In accordance with this invention there is provided a magnetic
focusing means for an electron 'beam comprising a plurality of annular
magnetic means positioned end-to-end to (Pricee provide a cylindrical
struoture, annular yokes of miagnetic material positioned intermediate
said magnetic means and extending radially inwardly of said cylinder
to produce magnetic effects in dclose proximity to ithe beam, and
means for avoiding unwanted resontance effects by the cavities
intermediate said yokes comprising non-magnetic metallic means
intermediate,adjacent of said yokes at their inner peripheries
bridging the gaps therebetween.
Embodimenrts of the invention will be descilibed with reference to the
accompanying drawings, in which:' Fig 1 is a oross-sectional view of a
portion of a magnetic electron beam focusing device incorporating the
feature of this invention, and -Fig 2 is 'a similar seational view of
a further modified form of this invention.
Turning now to Fig 1, the envelope of a travelling wave tube is shown
at 1 having disposed therein the usual helix The electron beam
traverses longitudinal of the envelope 1 within, the helix Externally
of the envelope 1 are provided a plurality of magnets 2 shown as
permanent magnets These magnets are arranged so that like poles face
each other and intermediate the poles of the magnets are provided yoke
m'embers 3 extending radially inwardly of the magnet The yoke pieces 3
are distributed along the axis of the tube so as to form an
approximate sine wave curve of the magnetic flux along this axis
Intermediate the inner peripheries of adjacent magnetic yokes 3 are
provided rings 4 of non-magnetic material In the form shown rings 4
have a step projection so as to inter-ilt with projeotions on the yoke
pieces However, it is clear that these may be fastened in place by
either means such as brazing or soldering and it is not necessary that
12. such interfitting be provided.
With this type of construotion the magnetic yokes may be brought into
as close proximity as possible to the electron beam so as to provide
the maximum focusing effect However, because of the continuous
conductive cylinder formed by the inner peripheries of,the miagnetic
yokes 3 and the rings 4, the electro-mag-70 netic waves cannot excite
the resonant volumes which exist intermediate these yoke members As a
result the magnetic assembly may be positioned as close to the beam as
is possible without disturbing the frequency response of the beam
because of the resonant cavity effects.
In Fig 2 there is shown a magnetic asseimbly substantially similar to
that shown in Fig.
1 However, in this construotion instead of using the inner peripheries
of the magnetic yoke assemblies to form the continuous cylinder for
shielding from the electro-magnetic effects, there is provided a
composite cylinder composed of rings of magnetc material 6 aniid rings
of non-m'agnetic aaterlal 4 forming a substantially continuous
cylinder outside the envelope 1 of the tube The rings of magnetic
material 6 are made,to extend along the cylinder substantially the
same longitudinal length as the inner peripheral surface of the
magnetic yokes 3, while the non-magnetic rings 4 substantially
bridge,the gap that otherwise would exist between these magnetic
yokes.
Thus,there is provided a -continuous magnetic focusing system similar
to that described in Fig 1 and having similar advaantages However, in
this construction the cylinder and the magnetic yoke assembly may be
separately constructed and then assembled so as to be properly
positioned as shown While the invention has been, described in
connection with specific embodiments thereof using permanent magnets,
it is clear that the principles thereof equallyl iapply to systems
using a plurality of individual electro-magnets with the siilarly
shaped magnetic yokes.
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* GB785111 (A)
13. Description: GB785111 (A) ? 1957-10-23
Improvements in and relating to tractors
Description of GB785111 (A)
c
PATENT SPECIFICATION
Inventors: ALBERT FREDERICK JOHN PINK and JOSEPH DAVEY 785 j,11 Date
of filing Complete Specification (under Section 3 ( 3) ofthe Patents
Act, 1949)Jan 29, 1954.
Application Date Feb5, 1953 No 3336/53.
Application Date Sept11, 1953 No 25206/53.
Complete Specification Published Oct 23, 1957.
Index at acceptance: -Classes 68 ( 1), F 12; and 79 ( 1), El K, T 3 K.
International Classification: -B 62 d E 21 c.
COMPLETE SPECIFICATION
Improvements in and relating to Tractors We, W E BRAY & COMPANY
LIMITED, a ment to the arms are preferably carried on the Company
organised under the laws of Great brackets.
Britain, of Fagg's Road, Feltham, Middlesex, The aforesaid means for
imparting up and 50 and COUNTY COMMERCIAL CARS LIMITED, a down
movement to the forwardly extending Company organised under the laws
of Great arms which carry the ancillary implements may Britain, of
Fleet, Aldershot, Hampshire, do comprise hydraulic or other jacks.
hereby declare the invention, for which we By means of the present
invention it is pospray that a patent may be granted to us, and sible,
with the use of unskilled labour, for a 55 the method by which it is
to be performed, to standard tractor, such as that known under be
particularly described in and by the follow the Registered Trade Mark
"Fordson " to be ing statement: converted into-an angle-dozing or
other opera-
This invention relates to track laying and tive unit and the handling
capacity of the wheeled tractors of that known kind compris equipment
to be matched to the power avail 60 ing an engine unit, a transmission
unit and able from the tractor engine Furthermore, in back axle unit
the casings of which units the case of a dozer blade, -it has the
advantage together form the frame and body of the that the overall
length of the mouldboard can tractor and hereinafter referred to as
the be reduced while still remaining sufficient to chassis give
14. coverage to the overall width of the trac 65 The purpose of this
invention is to enable tor unit when in its angle-dozing position,
that ancillary equipment, such as an angle-dozer or is with the
mouldboard or blade inclined to the bulldozer equipment, with
reference to which longitudinal axis of the tractor at an angle of'.
the invention is hereinafter illustrated, to be 25 -30 This relative
reduction in length fitted to a tractor not originally designed for of
the mouldboard is obtained by fitting it in 70 this purpose in such a
manner that no undue this manner permits the successful operation
stress is transmitted to the chassis and with of the tractor in more
confined spaces and out in any way detracting from the usefulness
under more arduous conditions where the of the tractor as a towing
vehicle A further greater power per unit length of blade is purpose of
the invention is the strengthening required 75 of the existing spring
system to take the addi A tie rod may be connected to and extend
tional loading imparted by the ancillary equip rearwardly from each
bracket and is arranged ment for connection with the back axle
casingsAlso According to another aspect of the invention each said
bracket may have a part extending equipment for a tractor which is
required to rearwardly and arranged for connection to the 80 move
implements under heavy loads, com chassis in the neighbourhood of the
back axle.
prises two brackets, each having means for This arrangement ensures
that the thrust set connecting it to the tractor and which brackets,
up by the ancillary implements, when in use, when fitted to the
tractor, are adapted for will be transmitted to the rear axle of the
tracattachment to opposite sides of the tractor tor without imposing
any offset or additional 85 chassis, two forwardly extending arms
loading of the track frames pivotally connected respectively to said
The invention is illustrated in the accorm-.
brackets so as to swing in an up and down panying drawings as applied
to a tractor, in direction, means for imparting pivotal move which:
ment to each said arm and spring means Figure 1 is a perspective
part-exploded view 90 attached to anchorages on the brackets for con
of a tractor showing the bracket and -the meansnection to mountings
for wheels or tracks and of attaching it to the tractor chassis and
the extending laterally of the brackets The means anchorages for the
additional springs:
on each bracket for imparting pivotal move Figure 2 is an elevation,
and lPricr 3 s 6 d l pi ii 1 t i i i 11 i i 1 i i i R i i i 785,111
Figure 3 is a plan view of a track laying tractor fitted with a
modified design of bracket having an extension arm; Figure 4 is a
front end-on-view showing the track laying tractor dozer unit of
Figures 2 and 3.
15. In the drawings there is shown a tractor comprising a chassis C (Fig
3) having members indicated at L which extend along both sides E
indicates the engine unit.
The endless tracks as shown in broken lines at T, and the track
sprockets at -S, S', each track and sprocket unit being mounted on a
longitudinally extending box frame F Transverse springing M (see Fig
4) is secured to the chassis C and interconnects it with the frames F,
the springing M hereinafter being referred to as, the main springs M.
While the invention is hereinafter described in relation to a
track-layipg tractor it can be applied to wheeled tractors Most
wheeled tractors have a rigid centrally suspended wheel axle, springs
not being standard especially in a two-wheel drive.
In four-wheel tractors where drive to the = front wheels is through a
chain in a casing which has a fulcrum on the rear axle it is the
practice to provide front or main springing between the chain drive
casings and the chassis An example of such a tractor is that known as
the " County Fourdrive ".
The invention is illustrated as applied to dozing equipment which
comprises a blade A attached by radius arms B to a girder frame
comprising forwardly extending arms D, this part of the equipment
being more or less standard.
In carrying out the present invention there is provided an auxiliary
bracket 1 for attach40, ment to the chassis of the tractor on each
side thereof In practice, the wheels or tracks of the standard tractor
are first removed and then by attaching the auxiliary brackets
consisting of plates 1, to the chassis, the latter is suitably
reinforced to carry the ancillary equipment, e g a dozer blade and
actuating mechanism therefor The auxiliary brackets may be fixed by a
set of screw studs 2 to the sides C of the chassis The standard wheels
or tracks are replaced by a track or wheel mounting F which as
compared with the normal mounting is strengthened to withstand the
additional loading imposed by the ancillary equipment and which as
explained later in connected to the bracket by an additional spring 6,
one of the main springs being indicated at M (Figure 4).
Thus it is possible to convert a normal tractor to a dozer tractor at
comparatively low cost.
As shown in Figure 1 the brackets 1 each include a forwardly extending
arm 3 in which are stud holes 4 which secure the extension 3 to a part
L which carries the radiator There are also four stud holes -2 by
which the extension and brackets are secured to a part of the chassis
Each bracket 1 includes a forwardly extending arm 3 in which are stud
holes for the studs 2 and having at its front end further stud holes 4
for other fixing studs, which secure extension 3 to a part L which
carries the radiator Each bracket 1 includes a laterally 70 projecting
16. step piece 5 to provide a seat for the fixing of a quarter elliptical
type spring 6 whose outer ends bear on a saddle plate 7 carried by the
wheel or track mounting F In the drawing the track mounting F is shown
75 supporting an endless track T which encircles sprocket wheels S and
S' Each saddle plate 7 has upstanding -guides 8 and is fixed to an
inverted U-section or girder frame 9 forming part of the wheel or
track mounting F and also 80 serving to house recoil springs The
additional springs 6 are preferably of multiple leaf type and
positioned at the point of balance of the chassis Instead of leaf
springs coil springs may be fitted, which entails extending the step
85 plates 5 The saddle plates 7 are arranged above the recoil spring
housings on the wheel or track mounting F, which housing free to react
against any immovable obstruction met by the tracks through the main
recoil springs 90 in the recoil spring housing and as such is capable
of swinging in an up and down direction about a transverse axis in
known manner.
The plates forming the brackets 1, as can be seen from Figure 1 extend
downwardly below 95 the chassis and carry laterally projecting pins
10, which provide fulcrums for the support frame D of the dozer blade
For convenience of assembly when converting a standard tractor, which
can be done by unskilled labour, 100 the frame D is provided at the
rear end of each of its arms with a detachable block 11 forming one
half of a split housing encircling a bearing sleeve, the other half 11
of the housing being in the end of the arm A resilient bush 12 may 105
be fitted over the pin 10 and is received in the split housing 11,
11-.
At its upper end each bracket plate 1 is preferably formed, as shown,
with a forwardly over-hanging part 13 provided with a fulcrum 110 pin
14 which pins constitute anchorages for the operating mechanism of the
dozer unit.
This mechanism may consist of hydraulically operating rams, one
arranged at each side of the chassis frame and including a cylinder
15, 115 one end of which is provided with a bearing sleeve 16 to
receive a bush formed preferably of rubber or other resilient material
and mounted on the anchorage pin 14.
Slidable within the cylinder 15 is a piston 120 which may be double
acting and has a piston rod 151 carrying at its end a socket 17 in
which is journalled a trunnion element 18 for engagement with lugs 20
on the dozer frame D The element may likewise be fitted with a
resilient 125 bush By fitting resilient couplings such as those known
under the Registered Trade Mark " Silentbloc " into the crank joints
of the jack elements and linkage members, it has the advantage that
not only do they absorb any 130 785,1 lii 3 shock, but accommodate any
misalignment that might occur.
17. In order to counteract any bending movements, to which, the rear axle
casings may be subjected, the tie rods 22 (not shown in Figure 1 but
shown in Figures 2 and 3) may be fitted between the plates 1 and
points 23 at the ends of the rear axle casings.
Referring now to Figures 2, 3 and 4 there is shown a tractor fitted on
each side thereof with a modified design of bracket comprising a plate
1 having a rearwardly extending arm for connection to the rear end of
the chassis by means of pedestal plate 26 In this modification the
plate is not provided with a forwardly extending arm but is secured
direct to the part L which carries the radiator As in the previous
arrangement the plate is provided with four stud holes through which
the studs attached to the chassis loosely extend The pedestal plate 26
in the embodiment illustrated is secured to the transmission housing,
to which the rear axle casings are mounted and are each provided with
a boss 27 having a pivotal mounting for the arm 25.
The provision of the arm 25, it will be appreciated, relieves the
bolts, by which the bracket is secured to the chassis, of torque or
shear set-up, such as when the tractor is driven forwardly to drive
the dozer blade into the ground, and similarly when the latter or
other ancillary equipment, e g a bucket, by which the dozer blade may
be replaced, is raised to an elevated position and to ensure this
relief clearance is provided in the holes through which the bolts
extend.
The tie rods 22 by which the brackets are additionally stayed, are
secured at their forward ends by bolts to the plates 1 and at their
rear ends by means of collars 29 to the rear axle casings.
It should be understood that while the present invention has been
illustrated as applied to the conversion of a standard tractor to a
track laying tractor for operating dozing equipment, it is equally
applicable to a half-track machine where half-tracks are fitted to the
rear of the tractor and the front wheels are used for steering in the
normal manner It should also be appreciated that in place of fitting
tracks, the normal wheels can be removed and replaced by extra large
size wheels, both as regards the driving wheels and the steering
wheels.
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18. * GB785112 (A)
Description: GB785112 (A) ? 1957-10-23
Improvements in the treatment of hides, skins and tanning liquors therefor
Description of GB785112 (A)
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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.
PATENT SPECIFICATION
785,112 V/ ODate of filing Complete Specification: Feb 18, 1954.
Application Date: Feb 26, 1953 No 5362 /53.
Complete Specification Published: Oct 23, 1957.
Index at Acceptance:-Classes 76, C 2 (A 2: G), C 2 I( 1: 3 B: 6 9), C
2 J( 3: 4: 7), C 2 X, E; and 121, B. International Classification:-C
09 h C 14 c.
COMPLETE SPECIFICATION.
in the Treatment of Hides, Skins and Tanning Liquors therefor.
We, DONALD BURTON, a British Subject, of 2 Eccleston Court, Kirkstall
Lane, Headingley, Leeds 6, in the County of York, RONALD REED, a
British Subject, of 3 Woodhall Park Avenue, Stanningley, Leeds, in the
County of York, and FRANCES OLGA FLINT, a British Subject, of
Faversham Hotel, Mount Preston, Leeds 2, in the County of York, 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 is concerned with improvements in or relating to the
treatment of hides and skins It relates mainly to the treatment of
hides and skins prior to tanning, or conversion into raw hide
products, parchment, gelatine, and glue, but is also concerned with
the treatment of tanned hides and skins, and also with improvements in
tanning liquors.
19. Mucoid materials or muco-polysaccharides are present in hides and
skins Such materials are essentially polymers of sugar-like compounds,
usually, though not invariably, formed by the linking together of
simple sugars or amino-sugars with simple sugar acids, or with other,
or the same simple sugars so that long, chain-like molecules are
formed Such sugars include substituted and chemically modified sugars
such as acetylated, methylated, sulphonated sugars and the like The
sugar acids and their compounds with alcohols are included as well as
their salts Mucoid materials are therefore quite distinct from the
proteins, which are essentially polymers of various types of amino
acids Mucoid materials are found in close association with all the
protein structures of hides and skins and the regions where they are
present in rich amount include the epidermal-corium junction, the
elastic tissue fibres, the corium fibres and the spaces between these
fibres.
The stability of the protein structures is i 45 determined by the
mucoid materials in which they are embedded If the mucoid materials
are modified, reduced in amount or removed entirely, the protein
structures remaining are loosened and their cohesion is greatly 50
modified.
An object of the present invention is to provide an improved process
for the depilation of hides and skins.
Another object of the invention is to pro 55 vide a process for the
treatment of hides and skins which enables hair, wool or other
keratinous covering structures to be obtained in substantially
undamaged condition and therefore of high quality 60 Yet a further
object of the invention is to provide an improved process for treating
hides and skins to render them more suitable for tanning and other
purposes.
Another object of the invention is to pro 65 vide a skin or hide in
which the grain surface or layer is very tight and smooth and free
from distortion.
Yet another object of the invention is to provide improved tanning
liquors 70 According to the present invention, a process for the
treatment of hides and skins consists in treating the hides and skins
with a composition which is capable of modifying the mucoid material
naturally present in 75 said hides and skins and comprising between
0.25 and 50 % of a commercial preparation of a carbohydrase or mixture
of carbohydrases and a buffer solution within the range p H 3-p H 12 5
80 A carbohydrase when used under the conditions of p H value and
temperature approImprovements priate to it, will attack and/ or
degrade and/or digest mucoid materials or mucopolysaccharides, as
hereinbefore defined.
Carbohydrases include polygalacturonidase, elastase, pectinase,
20. hyaluronidase, chondroitinase, and diastase, or as it is equally often
referred to, amylase.
The term "carbohydrase" has been used throughout the present Complete
Specification in preference to the term "mucolytic" used -throughout
the Provisional Specification, in view of the fact that in "Chemistry
& Technology of Enzymes"(Tauber, 1949) the scope of the term
"mucolytic" is defined more narrowly than the interpretation intended
to be given to this term when used originally in the present
Provisional Specification.
The treatment of the hides or skins with carbohydrases can be carried
out either at the beginning or at any one or more subsequent stages of
conversion into leather and other products of hides and skins Thus for
example, as we shall explain later, we have found it advantageous to
employ a carbohydrase or mixture of carbohydrases under the special
conditions which we shall e Iaborate, for the soaking back of fresh or
salted or dry-salted or dried or otherwise preserved or treated -hides
and skins, for the removal of hair, wool, fur or other keratinous
covering structures, for the loosening of the fibrous structures, for
the loosening of the fibrous structures of the corium or dermis of
such 36 hides and skins, and for bating them It is possible to
accomplish all these processes in one operation, but the operator may
wish, after soaking back, or liming, or de-liming, or bating by
practices already known to the art of leather making, to introduce our
process involving the action of -a carbohydrase or mixture of
carbohydrases.
We do not wish to restrict the use of our process to operations before
tanning, for we envisage its application to tanned material and to
material which has been dyed and/or -fat-liquored and/or finished By
hides and skins, we include also woolskins e g sheepskins and
fur-bearing skins or pelts Also so pieces of such hides and skins,
including the tails of fur-bearing animal skins, such as are used in
the manufacture of paint and other types of brushes By pieces of hides
and iskins, -w& mean -to include also pieces of limed or tanned hides
and skins and any such trimmings which are normally used for the
making of gelatine and glue; also we wish to include pieces and
trimmings of wool and fur-bearing skins and pelts, both in the tanned
and un-tanned condition Preserved or treated hides and skins means
hides and skins at all stages of processing including the finished
product.
The use of our process is meant to apply to all types of tannage and
treatments used for the hides and skins, pieces, trimmings, etc.
It is usual in depilation processes to adopt a process involving the
use of lime and a sulphide, such as sodium sulphide, for separ 70
ation of the hair and epidermis from hides and skins, or to use
21. proteolytic enzymes obtained from bacterial, mould, animal and plant
sources.
Such proteolytic enzymes bring about 75 depilation by disrupting and/
or digesting the essential protein structures of the epidermis and the
epidermal-corium junction, but these proteolytic enzymes have no
intrinsic action on the mucoid materials present in 80 hides and
skins.
It has now been found in accordance with this invention that
carbohydrases, which do not attack and/or digest the protein
structures, but only the mucoid materials, are 85 effective in
loosening the epidermal-corium junction of hides and skins and in
detaching the epidermis and its elaborated structures such as hair,
and sweat glands, entirely from the corium Carbohydrases attack the 90
mucoid material which is present at the epidermal junction and which
embeds the protein structures at this junction Before subjecting the
hides and skins to the action of a carbohydrase or mixture of 95
carbohydrases according to our invention the operator can, if he so
wishes, soak them back according to the well established practices of
the leather trade Thus, for example, he can soak the hides and skins
in water 100 with or without alkalis, wetting agents, bactericidal
agents and similar reagents commonly employed in soak liquors, without
prejudice to the subsequent treatment with a carbohydrase or mixture
of carbohydrases 105 Further the operator can, without prejudice to
the subsequent treatment with a carbohydrase, subject the hides and
skins to the mechanical operations of breaking, fleshing, and the like
110 This prior treatment of conventional soaking the hides and skins,
can, at the discretion of the operator, be dispensed with as we shall
describe later The soaked hides and skins are placed in a solution
containing the 115 carbohydrase or mixture of carbohydrases at a p H
value appropriate to the particular enzyme or mixture of enzymes used
By solution at a p H value appropriate to the particular enzyme -or
mixture of enzymes 120 used, we mean a buffer solution, that is an
aqueous solution which by its intrinsic chemical composition can
maintain its p H value approximately constant and so is able toresist,
or act as a buffer against, changes 125 in its p H value when hydroxyl
or hydrogen ions are added to it In selecting such a buffer solution
appropriate to the enzyme or mixture of enzymes used, we do not
restrict ourselves to any one buffer solution for the 130 785,112
785,112 carrying out of our process We have found however that it is
advantageous when using a carbohydrase or mixture of carbohydrases to
maintain the p H value of the solution approximately constant whilst
subjecting the hides and skins to the action of the enzyme or enzymes
Preferably the concentration of the buffer solution is 0 25 to 10 % by
weight.
22. By suitable choice of carbohydrase or mixture of carbohydrases, hides
and skins may be unhaired at p H values which are lower than those
obtainable in the usual liming process, and the high p H values used
in the latter process can be avoided Diastase has, for example, an
optimum effect at p H 6 5, pectinase at about p H 4 0, and pancreatic
elastase at about p H 8 9 Thus any distortion of the grain due to
rapid swelling or :20 plumping at very high p H values can be avoided,
and it is possible to control grain quality by choosing a carbohydrase
with an appropriate optimum p H value Improved grain surfaces can be
obtained at any p H in the range 3-12 5 p H.
It has been found, by experiment, that the concentration of the
carbohydrase or mixture of carbohydrases should generally be of the
order of 1 % by weight of commercial preparation for the most
beneficial results.
As a matter of expediency, it is found to be convenient to employ
temperatures in the range 15-35 ' C but it must be understood that
this is the preferred range of working and marginal variations at
either end of this range may on occasion be used with advantage and
are included within the scope of the invention In using our process,
we find it advantageous to maintain the temperature reasonably
constant at the value decided by the operator, throughout the duration
of the treatment of the hides and skins For cowhide, calf skin and
woolskins, we have found it preferable for the best results to
maintain the temperature of the buffer solution containing the enzyme
or mixture of enzymes at about 30 ' C throughQut the treatment For
goat skins, we prefer to maintain the temperature at about 350 C.
throughout their treatment It is to be understood however that the
particular temnperature used may be varied at the discretion of the
operator who may wish to employ lower temperatures with a
correspondingly longer time of treatment.
The hides and skins can be treated with the enzyme or enzymes under
the conditions already described, in a drum, paddle or pit or vat or
any suitable container, either with or without agitation, and/or
aeration.
The hides and skins are treated with the enzyme or enzymes according
to the conditions already described for periods ranging from 2 hours
to 7 days or more The period.
during which the hides and skins are subjected to the action of the
enzyme or enzymes may be selected by the operator to fit in with his
preferred cycle of daily operations, the type of hide or skin being
treated and the particular buffer solution, enzyme or 70 enzymes, and
the temperature of working employed.
With certain hides and skins, and using a paddle or a drum, the hair
and/or wool may be detached during the enzymatic 75 treatment as a
23. result of mechanical agitation or aeration Alternatively, after the
selected period of contact with the enzyme or enzymes solution, the
hides and skins may be withdrawn and unhaired or dewooled by 80
practices normal in the leather and fellmongering trades By these
means, hair, wool, fur and other keratinous structures may be
obtained, together with pelt The hair, wool, fur and other keratinous
struc 85 tures are of high quality, in that these protein structures
are undamaged by the action of the carbohydrase or carbohydrases, only
the material cementing such protein structures to the dermis or corium
of the hide 90 or skin being loosened and attacked by such enzymes For
these reasons, fibres of hair, wool, fur and other keratinous
structures may be obtained which are of high quality and which are
generally longer than those 95 obtained by existing methods, in that
they still possess the entire original, natural length.
In the method for the depilation of hides and skins described
hereinbefore, the expres 100 sion buffer solution containing enzyme or
mixture of enzymes, means that the enzyme or mixture of enzymes is
added to the buffer solution before the hides and skins are introduced
We do not preclude, however, the 105 addition of further amounts of
enzyme or enzymes to the solution, whilst the hides and skins are
being treated Indeed, in most cases it has been found advantageous to
add further quantities of enzyme or en 110 zymes at appropriate
intervals of time.
We have found that in addition to using the carbohydrase, or mixture
of carbohydrases, in conjunction with buffer solutions as described
previously, it is beneficial 115 to include simple salts of mineral
acids such as sodium chloride, sodium sulphate, potassium chloride in
the solution used for treating the hides and skins We have found that
such salts, or mixtures of such salts, 120 added to the buffer
solution in concentrations up to as much as 10 % by weight are
beneficial for a number of reasons Firstly, such salts control the
degree of swelling or plumpness of the hide or skin; secondly, 125
they activate the enzyme or enzymes and so provide for more economical
working; thirdly, they aid in the dispersion and solution of the
cementing interfibrillary material loosened by the enzymatic action
130 We have also found that we can with advantage use one or more
carbohyrases in conjunction with buffer solutions and temperature
control for the depilation of hides and skins by a further method of
working.
This consists in allowing the hides and skins to remain in the enzyme
solution or solution of enzymes made up as previously described for
suitable period of time, with or without agitation of the system The
hides and skins are then withdrawn so that enzyme solution is retained
by the hair, wool or fur The hides and skins are then allowed to stand
24. in piles, at temperatures in the range 15 to 35 ' C By piles we mean
stacking the hides and skins' either flesh to flesh, or hair side to
flesh, or hair to hair After standing in piles, the hides and skins
may then be unhaired or de-wooled according to known practices of the
arts of leather making and fell-mongering.
After preliminary treatment by the enzyme or enzymes 'as described
above, the hides or skins may alternatively be hung in chambers or
enclosed spaces maintained at any suitable temperature Individual
hanging provides the means for better temperature control.
Our invention also provides a method of de-wooling sheepskins and
dehairing hides and skins which comprises applying to the flesh side
of the skins a "paint" composition comprising one or more
carbohydrases, a buffer solution of p H value appropriate to 326 the
enzyme or enzymes chosen, and salts such as sodium chloride, sodium
sulphate, -potassium sulphate, calcium chloride, etc.
These components are mixed with a =thickener, which may be flour (all
types such as wheat, maize, barley, soya flour, etc), starch, bran,
gelatin, etc, so that a paste of the desired consistency is obtained;
the paste is painted onto the flesh side of the skins and allowed to
remain on the piled or hung skins or hides for a suitable period of
time and the loosened wool or hair subsequently pulled from the skins
or hides.
The concentration of the one or more carbohydrases in the paint
composition should -be at least 0 25 % by weight of commercial
preparation.
A composition comprising 0 25 to 50 % by weight of a commercial
preparation of a carbohydrase, up to 90 % by weight of a thickener
such as flour, starch, bran or gelatine and a buffer solution of p H
value within the range 3-12 5 and of concentration within the range 0
25 %/o to 10 % by' weight of the composition is particularly
effective.
In accordance with conventional methods for treating hides and skins
-preparatory to -tanning, in addition to depilation, it is necessary
to loosen the fibrous structures of the corium This is generally
accomplished by liming and by subsequent "bating" According to the
present invention, the fibrous structures can be loosened by the
action of one or more carbohydrases Although it is possible by the
present invention to prepare 70 hides and skins ready for pickling and
tanning in one operational treatment with these enzymes, we have found
that hides and skins unhaired or de-wooled by existing practices can
be conveniently and rapidly "loosened", 75 as a further preparation
for tannage, by subjecting them to the action of one or more
carbohydrases in the manner hereinbefore described.
Thus hides and skins which have been 80 both unhaired or de-wooled and
25. partially "loosened" as a preparation for tannage, may be further
prepared for tannage by "bating" with carbohydrases.
-By the terms "loosened" and "partially 85 loosened" is meant the
removal of more or less of the interfibrillary mucoid cement material,
in which the protein structures of the hide or skin are embedded In
the prior art, this necessary operation of rendering the pelt 90
structure more open is termed "loosening" or "opening up" and is
accomplished in the process of liming.
Further, we have found that even after tannage by existing and
conventional 95 methods, the hides, skins, sides, pelts, etc, may with
advantage be treated with a carbohydrase or carbohydrases in the
manner hereinbefore described Tanned stock needs to be evenly loosened
and opened up so that 100 the subsequent processes of dyeing, fat
liquoring and finishing may be carried out evenly and satisfactorily
We have found that the treatment of tanned stock according to our
invention is particularly useful in the 105 making of gloving and
suede leather A treatment of half an hour, or longer according to the
nature of the leather, with one or more carbohydrases, in the manner
hereinbefore described, has been found to im 110 part softness and
suppleness to the tanned stock We have found als-o that' dye'stnffs
and fat liquors-as applied in subsequent conventional operations now
go on to the tanned stock so treated, much more evenly, 115 so that
more level shades of dying can be obtained Certain dyestuffs are also
found to penetrate the hide or skin far more easily.
This is of importance when light and even pastel shades -of dyed
leather are required 120 and also in making of suede skins and sides,
in that penetration of the dyestuff is much greater and more even.
We have found that in treating tanned, or partly tanned, stock with
carbohydrases in 125 the manner hereinbefore described, it is
advantageous to restrict the p H value of the enzyme bath to a value
within the range 3 to 8 We have' found that treatment of tanned stock
with carbohydrases at p H '130 785,11 Iv a difficult matter One object
of the present invention is to improve the soaking back operation on
hides and skins by subjecting them to the action of one or more
carbohydrases which can attack and loosen the 70 mucoid components of
the interfibrillary cement material This is accomplished by subjecting
the fresh or salted or dry-salted or dried or otherwise preserved or
cured hides and skins to the action of carbo 75 hydrases in
substantially the same manner as hereinbefore described for the
depilation of hides and skins by these enzymes The fresh, or salted or
dry-salted or dried or otherwise preserved or cured hides and skins 80
are introduced into an aqueous buffer solution, of p H value
appropriate to the carbohydrase or carbohydrases selected, containing
such enzyme or enzymes, and sodium chloride in concentrations ranging
26. from 0 to 85 % by weight at a temperature maintained within the range
15 to 350 C, for a suitable period of time The penetration of the
enzyme solution may be facilitated by the inclusion of a wetting agent
in the solution 90 or by previous treatment of the said hides or skins
with a solution containing a wetting agent After soaking back has been
accomplished by this treatment, the operator can if he so wish, leave
the hides or skins in 95 the same aqueous buffer solution containing
the components hereinbefore mentioned in connection with depilating,
loosening or bating for a further period of time so that depilation,
and/or loosening of the fibrous 100 structures of the corium or
dermis, and/or bating may be achieved in the manner hereinbefore
described On the other hand, the operator may after soaking by the
method of our invention, withdraw the hides and 105 skins from the
enzymatic solution and further treat them by conventional methods as
used in the arts of leather making, fellmongering, raw hide,
parchment, gelatin and allied trades 110 In using our compositions for
soaking, depilation, bating and preparation for tannage, and in the
treatment of hides and skins in any form hereinbefore mentioned,
including tanned, dyed, fat liquored and finished 115 products of
hides and skins, we have found that the addition of certain
substances, unless otherwise present in the aqueous buffer solution,
exert an activating effect on the carbohydrase or carbohydrases as em
120 ployed according to our invention, and hence make for the more
economical and improved application of such enzymes Such activators
include anions such as phosphate, citrate, formate, borate, iodide and
hydro 125 sulphide ions; metallic ions such as calcium, copper, zinc
and chromium ions; hydrogen peroxide; simple sugars such as galactose,
dextrose and maltose; disaccharides such as sucrose; starch, yeast,
bran and the various 130 values above 8 is impracticable in that
stripping of tan may occur with vegetable-tanned leather and
overneutralization with chromed leather Hence the quality and value of
the leather may be impaired Also, we have found it impracticable to
treat tanned stock with carbohydrases below a p H value of 3 in that
either kind of leather may suffer damage at pl H values below 3.
It is well known that unless the operation of liming is carried out
carefully, a limed hide or pelt may manifest various degrees of fibre
tightness Thus the butt and neck regions may be quite tight, whilst
the flanks may be quite loose In the art of leather making, this
phenomenon is termed irregular "loosening" or "opening up" of the
fibre structure of the hide or pelt We have shown that it arises from
the irregular removal of mucoid material from the hide or skin during
liming This uneven distribution of mucoid material, and hence degree
of tightness or "opening up" of the fibre structures, leads to
irregular uptake of tans, dyestuffs and fat liquors According to the
27. present invention, this unevenness or irregularity in fibre structure
brought about by uneven liming, can be corrected by treating the
tanned stock with carbohydrases, according to the manner hereinbefore
described.
Tanned stock, when treated according to our invention, shows new
properties in that any mucoid material remaining in association with
the fibre structures is removed; thus the pelt structure becomes
evenly loosened or opened up This resulting evenness of fibre
structure is manifested by a regular degree of softness and suppleness
over the pelt and by the even or level uptake of dyestulfs and fat
liquors.
It is thus seen that the treatment with carbohydrases can, at the
discretion of the operator, be applied at any stage of the making of
leather by existing conventional methods.
Further, the operation of soaking back is a well established practice
in the leather trade and consists of treating fresh or salted or
dry-salted or dried or otherwise preserved :50 or cured hides and
skins with aqueous liquors with the objects of ( 1) restoring the hide
or skin as nearly as possible to the condition it was in after
flaying, ( 2) removing the salt from salted hides and skins, and ( 3)
wetting back the-fibrous structures of the hides and skins by
introducing water between them The success of many of the subsequent
operations in the preparation of hides and skins for tannage and other
purposes depends on how well this soaking operation is carried out
Many of the difficulties associated with soaking arise from the fact
that the interfibrillary cement material becomes hardened around the
fibres and hence makes the penetration of water 185,112 kinds of flour
These substances are effectiye in concentrations ranging from 1 to
5,000 parts by weight per 100,000 parts by volume of the
aforementioned buffer solua tion The simple effect of the addition of
such activators is to enhance the rate of removal of mucoid material
from the skin or hide.
The -pelt as obtained from the treatment of hides and skins with
carbohydrases, in addition to being useful for the making of leather,
= can also be converted into other products Thus another object of our
invention is -the production of raw-hide goods and parchments by
improved methods In the prior art of making raw-hide goods and
parchments from hides and skins, it is generally accepted that liming,
that is, a treatment with aqueous liquors containing calcium
hydroxide, is a necessary process.
We have found, however, that the pelt as obtained by our invention and
which does not involve the use of lime liquors, is suitable for direct
conversion into raw-hide goods and parchments Fiifther, in so far as
the pelt produced according to our invention is not at an
28. approximately constant p H value as when the liming process is used,
but can be produced over the wide range of p H values 3 to 12 5, new
types of pelt are now available for conversion into rawhide and
parchment products.
Similarly, the pelt made as described by subjecting hides and skins,
or pieces of trimmings of same, to the action of carbohydrases, may be
utilised for the making of gelatin and glue products It is well known
that the properties of a gelatin depend on the pretreatment given to
the pelt, and in the normal practice of making gelatin from hides and
skins, it is usual to subject them to long periods of contact with
lime liquors.
Our invention does not necessarily involve the use of lime liquors and
we have found that the pelt obtained by our method is rapidly and
easily convertible into gelatin by the conventional methods used in
gelatin manufacture -Further, since the pelt can be obtained according
to our invention over the range of p values 3 to 12 5, hitherto
unknown forms of gelatin now become available In accordance with our
invention, hides and skins may be subjected to the combined action of
both carbohydrases and proteolytic enzymes Thus in the compositions
involving the use of carbohydrases, we find that the addition of
proteolytic enzymes to the said compositions may be advantageous The
proteolytic enzymes are added to the compositions in concentrations
being within the range of O 025 % to 5 % -by weight of commercial
preparation, and are to be used under exactly similar conditions as
hereinbefore described for the treatment of hides 65 and skins with
carbohydrases.
By combined action of carbohydrases and proteolytic enzymes we mean
that both these types of enzyme may be added simul-taneously at the
start of the treatment of 70 the hides and skins or that the
proteolytic enzyme or enzymes may be added during their treatment with
carbohydrases.
The use of carbohydrases to produce improvements in vegetable tanning
liquors is 75 included within the scope of the invention.
It is well known that myrobalans and some other vegetable tanning
materials contain pectins and similar substances These are wholly or
partially extracted by water with 80 the tannins and so are present in
the resulting leach liquor or concentrated leach liquor, which is
usually called an extract It is also known that such extracts
sometimes gel and even solidify during storage We have 85 now found
that this gelation and solidification can be prevented by treatment of
the leach -liquor with a carbohydrase or a mixture of carbohydrases.
Further, _the pectic substances are closely 90 associated or combined
with the tannins.
By means of our invention, it is possible to break down these large
29. complexes to give a liquor or extract which has modified tanning
properties such as a mellower action 95 on hides or skins Furthermore,
by treating vegetable tanning liquors or extracts with a carbohydrase
or mixture of carbohydrases it has been found possible to modify their
colours as, for example, to make them paler 100 Preferably such
vegetable tanning liquors are buffered in the range p H 3-10 An
improved vegetable tanning liquor for use in accordance with the
invention comprises a vegetable tanning agent and one or more 105
carbohydrases in an aqueous extract buffered at p H 3-10, the
concentration of the said enzyme or enzymes in the liquor being from
0.025 % to 10 % by weight of commercial preparation, said buffered
extract having a 110 concentration of buffering materials of 0 25 % to
10 % by weight.
The invention will now be more fully described by reference to the
following Examples wherein w/v means weight/ 11 n volume, i e g /cc or
Kg /litre.
Ex AMP Lw I; 1- A dozenwi- salted calfskins after being soaked, washed
and fleshed, were introduced into the depilating bath made up in 120
the following manner: 6,800 g sodium acetate crystals (C Ha COO Na 3 H
20) were added to 5 litres glacial acetic acid dissolved in 10 litres
of water contained in a paddle, -so that a buffer solution of about p
H 4 0 125 was obtained This buffer solution was diluted with water to
make a total volume -of 250 litres Common salt was added to I= 785,112
container with a loosely fitted lid; the temperature being maintained
at 300 C throughout the process The skins were allowed to remain in
the depilating bath for 24 hours without agitation after which time
the wool was loose The skins were withdrawn from the bath and pulled
to obtain the wool The pelts thus obtained were suitable for liming or
bating or pickling or tannage or for conversion into parchment-like
products by normal trade practices.
EXAMPLE 4.
Six wet salted domestic woolskins were soaked for 24 hours in water,
They were then transferred to the depilating bath of substantially the
same composition as described in Example 1 but containing in addition
0 5 % w/v of a non-ionic wetting agent of the
alkylphenylpolyglycolether type The pelts were allowed to remain in
this modified depilating bath for 24 hours, the temperature being
maintained at 30 C throughout the process The skins were withdrawn and
pulled to obtain the wool The pelts thus obtained were suitable for
the same processes as previously mentioned.
give a final concentration of 1 % w/v; 500 g.
calcium pyrophosphate was added to provide a source of activating
calcium and pyrophosphate ions The temperature of the solution was
brought to and maintained at C 2 Kg of a commercially available
30. pectinase preparation with bran as a carrier were added The skins were
allowed to remain in this depilating bath for 36 hours when the hair
was loose The skins were then withdrawn from the bath and unhaired by
conventional methods The pelts thus obtained were suitable either for
liming or bating or pickling or tannage, or for conversion into
parchment, gelatin or glue, by normal trade practices.
If in this Example the sodium acetate is replaced by 1,720 g sodium
formate and the glacial acetic acid by 5,620 g of 90 % formic acid,
250 litres of a buffer solution with p H value 3, may be obtained 21
kg.
of common salt may be added to give a final concentration of 1 % w/v
together with 500 g calcium pyrophosphate to provide a source of
activating calcium and pyrophosphate ions This buffer solution may be
added to a bath containing pectinase as active ingredient.
EXAMPLE 2.
Twelve wet salted calfskins similarly treated were placed in a
depilating bath of exactly the same composition as described in
Example 1 contained in a drum The skins were drummed for 24 hours by
which time the loosened hair had been removed by the mechanical action
of the drum The pelts thus obtained were suitable for liming, or
conversion into parchment, or gelatin, or glue, or bating, or
pickling, or tannage by normal trade practices.
In another experiment, twelve wet salted calfskins similarly treated
were placed in a depilating bath of exactly the same composition as
described above The skins were paddled for six hours after which time
they were hauled out and piled, hung or folded in a warm, humid
atmosphere of a temperature within the range of 15 to 35 C Any
tendency to dry out was counteracted by damping the skins with the
original depilating solution After 40 hours, the skins were unhaired
by conventional methods.
EXAMPLE 3.
In another experiment, one dozen wet salted domestic woolskins were
soaked for 24 hours in water and were then transferred to an aqueous
bath containing 0 5 % w/v of a non-ionic wetting agent of the
alkylphenylpolyglycolether type at 30 C After 2 hours contact with
this wetting agent the woolskins were transferred to the depilating
bath of exactly the same composition as described in Example 1 and
contained in a wooden o 80 EXAMPLE 5 90
One dozen wet salted domestic woolskins were soaked in water for 24
hours They were then transferred to the modified depilating bath
containing 0 5 % w/v of a nonionic wetting agent of the
alkylphenylpoly 95 glycolether type in addition to the components
already described The skins were allowed to remain in this depilating
bath without agitation and at a temperature of C for 2 hours The skins
31. were then 100 in a suitable condition to be withdrawn and piled, hung,
folded or painted as described in the next Example, in a humid
atmosphere of temperature within the range of 15-35 C any tendency to
dry out was counteracted 105 by damping the skins with the original
depilating solution After 36 hours the skins were pulled and wool and
pelt obtained.
EXAMPLE 6 110
Wet salted domestic woolskins were soaked in water for 24 hours and
then drained They were then "painted" on the flesh side with a paint
consisting of 50 % by weight wheat flour, 50 % by weight pectinase 115
bran preparation mixed to a suitable consistency with an
acetate/acetic acid buffer solution made in the manner described in
Example 1 and containing 1 % by weight of common salt The skins were
then piled 120 flesh to flesh in a humid atmosphere at a temperature
of 15 to 35 C After 48 hours the skins were pulled and wool and pelt
obtained.
785,1 i 2 EXAMPLE 7.
12 fully chromed calfskins, prepared by conventional methods of
leather manufacture in "the blue" condition and damp, that is, in the
condition immediately prior to the conventional practice of
neutralisation before dyeing were introduced into a bath of exactly
the same composition as that previously described in Example 1 for the
depilation of calfskin The operation was carried out in a paddle, and
the stock was paddled for 3 hours, the temperature being maintained at
300 C.
After this loosening treatment, the skins were withdrawn and horsed up
overnight.
They were then dyed according to normal practice.
EXAMPLE 8.
6 fully chromed calfskins were treated in exactly the same manner as
described in Example 7, but after horsing up overnight were
neutralised before dyeing.
EXAMPLE 9.
6 calfskins chrome tanned in a manner suitable for vegetable retannage
were treated in exactly the same manner as described in Example 8
After horsing up overnight, these were treated with vegetable tanning
extract containing myrabolams After the completion of this combination
tannage the skins were dyed according to normal practice.
EXAMPLE 10.
A wet salted calfskin after being soaked, washed and fleshed was
introduced into a depilating bath made up in the following manner:410
g glycine and 200 g caustic soda were dissolved in a convenient amount
of water so that a buffer solution of p H value about 10.4 was
obtained This buffer solution was diluted with water to make a total
32. volume of 20 litres Common salt was added to give a final
concentration of 2 % w/v Potassium iodide was added to give a final
concentration of 0 5 % w/v to provide a source of activating iodide
ions The temperature of the solution was maintained at 30 C.
and 40 gm of the mixture of carbohydrases known as elastase were added
in powder form The temperature of the solution was maintained at 30 '
C throughout the treatment and the skin was paddled continuously.
The skin was allowed to remain in this depilating bath for 20 hours
when the hair was loose The skin was then withdrawn from the bath and
unhaired by conventional methods The pelt thus obtained was suitable
either for liming or for conversion into parchment or gelatine or
glue, or bating or other normal trade practices.
EXAMPLE 11.
A wet salted calfskin after being soaked, washed and fleshed was
introduced into a depilating bath made up in the following manner: 115
g of borax and 300 g of boric acid were dissolved in a convenient
amount of water so that a buffer solution of about p Hl 7 0 was
obtained The buffer solution was diluted with water to make a total
volume of 20 litres Common salt was.
added to give a final concentration of 2 % wlv.
The temperature of the solution was brought up to 30 ' C when 100 g of
a commercially available powdered preparation of diastase were added.
The temperature was maintained at this value throughout the treatment
and the skins were paddled for 20 hours The skin was then withdrawn
from the bath and unhaired by conventional methods.
( 65 s O EXAMPLE 12.
Six squirrel tails in the partially tanned or tanned condition, i e as
normally sup 55 plied to brush manufacturers by the fur trade, were
soaked overnight in cold water.
They were then placed in a depilating bath of composition exactly
similar to that described in Example 1 for the depilation of 90
calfskins and contained in an open vessel of suitable size The
temperature was maintained at 350 C and the treatment was allowed to
proceed without agitation for 40 hours 95 The tails were then
withdrawn from the bath, rinsed in water and partially dried by
hydroextraction The fur from three of the squirrel tails was then
pulled off in the manner normally used in the brush making 100
industry The remaining three tails were dried out completely, stored
for three weeks, wet back with cold water, hydroextracted and the fur
fibres pulled off in the manner hereinbefore described 105 EXAMPLE 13.
A side of a sun-dried Nigerian c-owhide was placed in a soak liquor
contained in an open soak pith aid of exactly similar compositi 6
ionto that described in Example 1 110.
for the depilation of calfskins The temperature of the liquor was
33. maintained at about 250 C for 48 hours, with occasional agitation by
means of a wooden pole After this treatment, the side was in a soaked
115.
condition and ready for liming and subsequent operations according to
conventional practices.
EXAMPLE 14.
A side of a sun dried Nigerian cowhide 120.
was placed in a soak liquor contained in an open soak pit and of
exactly similar composition to that described in Example 1: for
785,112 which treatment the hair was loose The skin was withdrawn from
the bath and unhaired by conventional methods The pelt thus obtained
was suitable either for liming, or for conversion into parchment or
gelatine or glue or bating or other conventional treatments.
EXAMPLE 18.
Two fully chromed calfskins prepared by conventional methods of
leather manufacture, in the "blue" and damp condition, i e.
in the condition immediately prior to the conventional practice of
neutralisation before dyeing were introduced into a loosening bath of
the following compositions and contained in a drum.
Sodium acetate crystals were added to 200 cc glacial acetic acid,
dissolved in a convenient amount of water so that a buffer solution of
about p'H 4 0 was obtained This buffer solution was diluted with water
to make a total volume of 10 litres Common salt was added to give a
final concentration of 1 % w/v.
The temperature of the solution was brought to, and maintained at, 300
C 100 g.
of a commercially available pectinase preparation with bran as a
carrier were added together with 25 g papain The function of the
papain is to aid in the dispersion and/or solution of any porteinous
material loosened by the action of the pectinase The skins were
drummed for 3 hours.
After this treatment the skins were withdrawn and horsed up overnight
They were then dyed according to normal practice.
the depilation of calfskins The temperature of the liquor was
maintained at about 25 C.
for 48 hours with occasional agitation by means of a wooden pole After
this time the hide was in a soaked condition and was then fleshed
prior to depilation A further addition of pectinase-bran preparation
was then added to give a total concentration of approximately 2 % w/v
The temperature was then brought to 300 C and maintained there for a
further 40 hours, again with occasional agitation by means of a wooden
pole The side was then hauled out and depilated by a convenient
method: The side was then suitable for either liming, bating or
tanning by existing methods.
34. EXAMPLE 15.
A delimed calfskin in the condition normally to be expected before
"bating" by conventional methods was placed in a paddle containing a
bating liquor of exactly similar composition to that described in
Example 1 for the depilation of calfskins.
The temperature of the liquor was maintained at 35 C for 3 hours, the
skin being paddled continuously After this treatment the skin was soft
and porous, in the manner of bated stock, and was ready for pickling
or tanning by conventional methods.
EXAMPLE 16.
A dried Australian wooled sheepskin was placed in a soak liquor
contained in an open soak pit and of exactly similar composition to
the depilating bath described in Example 3 for the dewooling of
domestic sheepskins.
The temperature of this static bath was maintained at 25 " C for 18
hours The now soaked sheepskin was withdrawn and was suitable for
subsequent treatment either by conventional methods or as hereinbefore
described for domestic sheepskins.
EXAMPLE 17.
A wet salted calfskin after being soaked, washed and fleshed was
introduced into a depilating bath made up in the following manner:410
g glycine and 200 g caustic soda were dissolved in a convenient amount
of water so that a buffer solution of about p H 10 4 was obtained.
This buffer was diluted with water to make a total volume of 20
litres.
Common salt was added to give a final concentration of 2 % w/v The
temperature of the solution was maintained at -30 C.
g of the mixture of carbohydrases known as elastase were added
together with 20 g.
of trypsin The temperature of the solution was maintained at 30 C
throughout the treatment and the skin was paddled continuously The
skin was allowed to remain in this depilating bath for 20 hours after
EXAMPLE 19.
g of a commercially available bran 1 OO preparation of pectinase were
extracted with 250 cc of water at 30 " C The solution of the enzyme
was filtered and added to 3 litres of a myrabolams liquor of S G 1 06
Myrabolams liquor is naturally buffered in the 105.
range of the present invention The resulting liquor was maintained at
30 " C for 36 hours It was then concentrated by evaporation under
reduced pressure to a specific gravity of 1 2 The resulting extract
was 110 allowed to stand for 3 months at temperatures ranging from 4 "
C to 10 " C No gelation or solidification occurred.
EXAMPLE 20.
g of a commercially available bran 115 preparation of pectinase were
35. extracted with cc of water at 30 " C The filter solution of the enzyme
was added to 200 cc of a quebracho liquor of specific gravity 1 06.
Quebracho liquor is naturally buffered in 120 the range of the present
invention The resulting liquor was maintained at 30 " C.
for 36 hours As a control, 20 cc of water were added to 200 cc of the
quebracho 785,112 liquor of specific gravity 1 06 The control liquor
was also maintained at 30 ' C for 36 hours Both liquors were diluted
25 times and the colour determined with a Lovibond a Tintomreter The
word Lov I Bo ND is a Regisfered Trade Mark The control gave the
following figures:Reds 3 8 Yellows 6 4 The treated liquor was
obviously paler than the control and gave the results:Reds 2 8 Yellows
4 5 EXAMPLE 21.
Two dozen fully chromed-calf skins prepared by conventional methods of
leather manufacture in "the blue" condition and damp, that is in the
condition immediately prior to the conventional practice of
neutralisation before dyeing are introduced into a bath made up in the
following manner:2,500 g of boric acid and 32 g of caustic soda flake
are dissolved in water contained in a paddle so -that a buffer
solution of about p H 8 0 is obtained This buffer solution is diluted
with water to make a total volume of 250,000 cc Common salt is added
to give a final concentration thereof of 1 % w/v.
The temperature of the solution is brought to 30 ' C 2 4 Kg of a
commercially available diastase preparation are added The skins are
paddled in the bath for 3 hours, the temperature being maintained at
30 ' C.
After this treatment, the skins are withdrawn and horsed up overnight
They are then dyed according to normal practice.
In the foregoing Examples, only buffer compositions of p H values 4,
7, 8 and 10 4 have been specifically illustrated.
It is clearly to be understood, however, that buffer compositions
cover the range of p H values 3 to 12 5, as exemplified by: p H RANGE
3 TO 6.
5,000 parts by volume of glacial acetic acid, are diluted with water
and 50 parts by weight of caustic soda flakes are added to this
solution.
The buffer solution of p H value 3 so made, is diluted with water to
make a total volume of 250,000 parts by volume.
By increasing the amount of caustic soda flakes from 50 parts by
weight to 3,200 parts by weight, a buffer solution of p H value 6, is
obtained Buffer solutions with p H values between 3 and 6 can be
obtained by adding caustic soda flakes within the-range 50 -to 3,200
parts by weight, to the above mentioned amount of glacial acetic acid.
p H RANGE 5 8 TO 8.
1,700 parts by weight of potassium dihydrogen phosphate are I
36. dissolved -in water and 37 parts by weight of caustic soda flakes are
added to this solution The buffer solution of p H value 5 8 so made,
is diluted with water to make a total volume of 250,000 parts by
volume.
By increasing the amount of caustic soda flakes from 37 parts by
weight to 470 parts by weight, a buffer solution of p H value 8 is
obtained.
Buffer solutions with p H values between 5.8 and 8 can be obtained by
adding caustic soda flakes within the range 37 to 470 parts by weight,
to the above mentioned amount of potassium dihydrogen phosphate.
p H RANGE 8 TO 94.
2,472 parts by weight of boric acid are dissolved in water and 32
parts by weight of caustic soda flakes are added to this The buffer
solution of p H value 8 0 so made is diluted with water to make a
total volume of 250,000 parts by volume By increasing the amount of
caustic soda flake from 32 parts by weight to 250 parts by weight, a
buffer solution of p H values 9 4 is obtained.
Buffer solutions with p H values between 8 and 9 4 can be obtained by
adding caustic soda flakes within the range 32 to 250 parts by weight,
to the above mentioned amount of boric acid.
p H RANGE 8 45 To 12 5.
1,500 parts by weight of glycine are dissolved in water and 50 parts
by weight of caustic soda flakes are added to this solu 95 tion The
buffer solution of p H value 8 45 so made, is diluted with water to
make a total volume of 250,000 parts by volume.
By increasing the amount of caustic soda flakes from 50 parts by
weight to 2,400 parts 100 by weight a buffer solution of p H value 12
5 can be obtained Buffer solutions with p H value between 8 45 and 12
5 can be obtained by adding caustic soda flakes within the range 50 to
2,400 parts by weight to the 105 above mentioned amount of glycine
Such buffer compositions may be substituted for the buffer
compositions mentioned in the Examples, with equally satisfactory
results, always provided, of course, that the appro l 11 priate enzyme
is used In the foregoing Examples, the only activators mentioned by
name consist of, sodium ions, calcium ions, pyrophosphate ions, wheat
flour, iodide ions, potassium ions 115 and borate ions It is to be
understood that any of the activators hereinbefore detailed, can be
substituted for the activators mentioned in the Examples, with equally
satisfactory results 120 In the foregoing Examples, only the
carbohydrases elastase, disease and pectinase have been specifically
illustrated It is to -be understood' however, that the other 785,112
wool or fur can occur, Hence the use of pectinase leads to the
preparation of high quality keratinous structures.
Whilst in the foregoing Examples only a non-ionic wetting agent has
37. been disclosed, it is to be understood that the invention will work
satisfactorily with a cationic wetting agent as exemplified by cetyl
pyridinium bromide, or with an anionic wetting agent as exemplified by
the sodium salt of dodecyl benzene sulphonate.
carbohydrases hereinbefore referred to, can also be employed with
satisfactory results, always provided of course the appropriate p HI
range is used.
In the foregoing Examples, the proportions of carbohydrase used cover
the range 0 2 % to 50 % by weight It is to be understood, however,
that this range is not critical As little as 0 025 % by weight of
carbohydrase can be employed effectively.
The precise proportion chosen is a question of economics Similarly, in
the foregoing Examples, the proportions of proteolytic enzymes cover
the range 0 1 % to 0 25 % by weight but it is clearly to be understood
that the concentrations of proteolytic enzyme may range from 0 025 %
to 5 % by weight.
Of the carbohydrases hereinbefore mentioned the use of pectinase for
achieving the various objects of the invention is strongly favoured
The practical advantages of using pectinase as the carbohydrase can be
briefly summarised as follows:It has optimum activity at a p H value
of 4.0 The development of bacteria is greatly restricted at this value
and hence any bacterial damage to the hide or skin is obviated
Further, in bringing about soaking, depilation, loosening and bating
of the hide or skin at this p H value the pelts obtained by our
invention are in an ideal condition for tannage which, according to
conventional methods, is usually commenced under acid conditions and
at a p H value near to 4.
Thus the use of pectinase as the carbohydrase leads in practice to a
reduction of the number of handling operations and hence to greater
economy In the prior art hides and skins are mainly unhaired and
loosened by lime liquors of p H value about 12.5 Before such limed
stock can be tanned it is necessary to reduce the p H of the stock
gradually by the separate operation of deliming and often complete the
loosening by the further operation of bating Also, in order to bring
the stock into the -correct condition for tannage a -50 pickling
operation is 6 ften employed.
By using pectinase as the carbohydrase at p H values about 4 these
separate operations are unnecessary.
A further advantage of using pectinase at p H values near 4 is that
the hair, wool, fur and other keratinous structures of hides and skins
can be obtained in substantially undamaged form It is well known that
hair, wool, fur and other keratinous structures are easily damaged by
prolonged contact with alkaline solutions.
However, by bringing about depilation under the slightly acid
38. conditions as hereinbefore specified when using pectinase according to
our invention no damage to the hair,
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