2. This invention relates to a t r a n s l u c e n t , stain absorbent film which
is applied as a coating of a f i l l e d a c r y l i c latex to a s u b s t r a t e such as
a metal or a p l a s t i c . More p a r t i c u l a r l y , the invention r e l a t e s to an
aqueous, film-forming composition comprising an a c r y l i c latex and a s o f t ,
w a t e r - i n s o l u b l e e x t e n d e r pigment. S t i l l more p a r t i c u l a r l y , it r e l a t e s t o
metal a r t i c l e s having an i n t e g r a l , t h r e e - d i m e n s i o n a l , simulated wood g r a i n
in its surface and a s t a i n - a b s o r b e n t coating on its s u r f a c e .
The t r a n s l u c e n t film of this invention is d i s t i n g u i s h e d from a t r a n s -
parent one in that it is s l i g h t l y opaque, p e r m i t t i n g the imperfect t r a n s -
mission of light relected from the s u b s t r a t e . The film is capable o f
absorbing an applied stain while s t i l l exposing the color and markings o f
the s u b s t r a t e .
Various techniques have been used over the years to simulate a wood
grain on metal panels. Among these is the lamination on such a panel of a
vinyl film having a wood grain p a t t e r n p r i n t e d thereon. The film is sub-
ject to delamination and permanent d i s f i g u r e m e n t by tearing or s c u f f i n g
actions. Another technique is the p r i n t i n g of the wood grain p a t t e r n
d i r e c t l y on the metal. The printed p a t t e r n is very s u s c e p t i b l e t o
s c r a t c h i n g and scuffing. Restoration to the o r i g i n a l statee is exceed-
ingly d i f f i c u l t . A technique r e q u i r i n g a r t i s t i c a b i l i t y is the manual
s t a i n i n g of a metal panel to give a streaked appearance resembling a
wood g r a i n .
3. Furthermore, as the p a t e n t e e s in U.S. Patent No. 3,811,915 o b s e r v e ,
such simulated wood g r a i n s have the disadvantage of looking and f e e l i n g
f l a t as compared to the three-dimensional look and feel of most n a t u r a l
; woods. In said p a t e n t , there is taught a method for simulating a t h r e e -
dimensional wood grain without the need for recourse to techniques such as
mechanical embossing. The method taught comprises applying a c o n v e n t i o n a l
background-forming groundcoat to a substrate, p r i n t i n g a wood grain on t h e
dried groundcoat with a graining ink containing a silicone f l u i d , and cover-
ing the printed groundcoat with a conventional top coat. The p a t e n t e e s
teach that the groundcoat is normally pigmented to provide the desired con-
t r a s t with the g r a i n i n g i n k .
In the past, c o a t i n g s intended as stainable base coats g e n e r a l l y were
pigmented so that an opaque film would be formed on the s u b s t r a t e . Ground-
coats of this sort are used in the inventions described in U.S. Patent Nos.
1,651,136; 2,248,254; and 3,847,646. A method for producing a " c r a c k l e d "
antique finish is d e s c r i b e d in U.S. Patent No. 3,692,557. Said method
u t i l i z e s a composition comprising an acrylic resin emulsion, finely ground
marble, p o l y u r e t h a n e , and water. The composition may be applied as b o t h
the f i r s t and t h i r d coatings on a substrate, the second coating being a
water soluble dye, or, in the case where the substrate is n o n - a b s o r b e n t ,
the w a t e r s o l u b l e dye is applied f i r s t and the a c r y l i c / p o l y u r e t h a n e emul-
sion is applied over the dried dye. In either case, the water soluble dye
is said to "bleed through" upwards into the third or uppermost coating t o
form the antique looking f i n i s h having a cracked s u r f a c e .
In many i n s t a n c e s , pigments which provide color and opacity to a
groundcoat also have the e f f e c t of sealing the film so that a s t a i n is n o t
absorbed or, at b e s t , it is absorbed unevenly.
Now, it has been discovered that a s u b s t a n t i a l l y c o l o r l e s s , t r a n s l u -
cent film capable of absorbing an applied stain may be formed on a s u b s t r a t e
by coating the s u b s t r a t e with an aqueous composition comprising an a c r y l i c
latex and a w a t e r - i n s o l u b l e extender pigment having a mean p a r t i c l e size o f
from about 5 to about 7 microns, then drying said coating by a s u i t a b l e
method.
The acrylic l a t i c e s used in this invention are aqueous emulsions of
a c r y l i c r e s i n s ; the emulsions have a solids content of from about 30% t o
about 45% by weight. The resins c o n s t i t u t e s u b s t a n t i a l l y all of the s o l i d s
4. present. Homopolymers and copolymers of alkyl a c r y l a t e s and m e t h a c r y l a t e s
and copolymers of such monomers with a c r y l o n i t r i l e , acrylic and m e t h a c r y l i c
acids, styrene, and s i m i l a r vinyl monomers are examples of the a c r y l i c r e s i n s
which are useful as the film forming c o n s t i t u e n t s of the composition of t h i s
invention. The term "alkyl" is used herein to mean an alkyl group h a v i n g
from 1 to 8 carbon atoms. Acrylates and methacrylates in which the a l k y l
group contains from 1 to 3 carbon atoms are p r e f e r r e d . Copolymers of such
esters with each other and/or with one or more of the monomers s p e c i f i c a l l y
mentioned above are p a r t i c u l a r l y p r e f e r r e d . The films deposited by t h e
a c r y l i c l a t i c e s useful in t h i s invention are generally c h a r a c t e r i z e d by
good resistance to water, high humidity, s a l t spray, oil and s o l v e n t s .
The aqueous composition of this invention comprises from about 10% t o
about 15% of, the a c r y l i c r e s i n by weight. Water c o n s t i t u t e s from about 10%.
to about 40% of the weight of the composition; this includes water in t h e
acrylic latex and added w a t e r .
The size of the extender pigment p a r t i c l e s is c r i t i c a l . Although a
mean p a r t i c l e size of from about 5 to about 7 microns is generally a c c e p t a -
ble, it is p r e f e r r e d that it be no g r e a t e r than about 6 microns. A maximum
p a r t i c l e size of about 25 microns is also p r e f e r a b l e . It is also i m p o r t a n t
that the extender pigment be a soft m a t e r i a l , i . e . , one having a h a r d n e s s o n
the Moh scale of about 4 or less. Materials such as calcium carbonate, z i n c
phosphate and barium s u l f a t e are examples of the w a t e r - i n s o l u b l e , soft e x -
tender pigments useful in this i n v e n t i o n . P a r t i c u l a r l y useful are a z i n c
phosphate having an average p a r t i c l e size of about 6 microns and c a l c i u m
carbonate having a mean p a r t i c l e size of about 5.5 microns.
The weight r a t i o of extender pigment to a c r y l i c resin ranges from a b o u t
1.5:1 to about 3.6:1. A p r e f e r r e d r a t i o is from about 2.5 to about 3 . 6 .
The amount of extender pigment in the aqueous composition is from about 15%
to about 50%, p r e f e r a b l y from about 25% on up.
The viscosity of the aqueous compositions containing such large amounts
of extender pigment is reduced by t i t a n a t e coupling agents such as t h o s e
described in U.S. Patent Nos. 4,069,192; 4,080,353; 4,087,402; 4 , 0 9 4 , 8 5 3 ;
4,098,758; and 4,122,062, which are incorporated herein. Examples of such
coupling agents include isopropyl t r i i s o s t o a r y l t i t a n a t e , t i t a n i u m
d i - ( d i o c t y l p y r o p h o s p h a t e ) oxyacetate, and d i - ( d i o c t y l p y r o p h o s p h a t o ) e t h y l e n e
t i t a n a t e . Quarternary ammonium s a l t s of those t i t a n a t e coupling a g e n t s
5. having an acidic function are p a r t i c u l a r l y useful and are p r e f e r r e d com-
ponents of the compositions of this invention. E s p e c i a l l y p r e f e r r e d a r e
the quaternary ammonium s a l t s of 2-dimethylamino methyl propanol w i t h
e i t h e r titanium d i - ( d i o c t y l p y r o p h o s p h a t e ) o x y a c e t a t e or d i - ( d i o c t y l p y r o -
phosphato) ethylene t i t a n a t e .
The aqueous composition of this invention contains from about 0.25%
to about 0.75% of the t i t a n a t e coupling agent, based on the weight of t h e
extender pigment. A p r e f e r r e d amount is from about 0.3% to about 0.5%.
Water soluble solvents such as ethylene glycol, propylene g l y c o l ,
i s o p r o p a n o l , butyl c e l l o s o l v e and the like may be added to the aqueous
composition in order to improve s p r a y a b i l i t y of the composition and t o
r e g u l a t e the drying time during film formation. The amounts used will d e -
pend on the nature and amounts of the other components and the d e s i r e d
drying time but such s o l v e n t s usually c o n s t i t u t e from about 4% to about 10%
of the t o t a l weight of the aqueous composition. Mixtures of the s o l v e n t s
are e s p e c i a l l y useful for the p u r p o s e s .
The v i s c o s i t y of the aqueous compositions may be adjusted as d e s i r e d
by the addition of c e l l u l o s i c thickeners such as the m e t h y l c e l l u l o s e e t h e r s ,
e.g. hydroxypropyl m e t h y l c e l l u l o s e , and carboxymethyl c e l l u l o s e . C r o s s l i n k e d
a c r y l i c or methacrylic acid copolymer emulsions also function as t h i c k e n e r s
when a c t i v a t e d by a base such as ammonium hydroxide. Prom about 0.1% t o
about 0.5% by weight of the aqueous composition is a g e n e r a l l y s u f f i c i e n t
amount of t h i c k e n e r .
Non-ionic s u r f a c t a n t s and/or s i l i c o n e s may be used in minor amounts
to control foaming of the aqueous composition during i t s p r e p a r a t i o n .
Fig. 1 is a photograph of a stained metal panel i l l u s t r a t i v e o f
this i n v e n t i o n .
The metal a r t i c l e is p r e f e r a b l y made of s t e e l but other metals such as
aluminum, copper, tin, and i n h e r e n t l y colored alloys such as brass and
bronze are also contemplated as the s u b s t r a t e in this invention. The a r t i c l e
may be simply sheet metal or it may be a shaped a r t i c l e made by bending s h e e t
metal or by molding the metal. Steel doors for houses and other b u i l d i n g s ,
i . e . , a r c h i t e c t u r a l doors; door jambs, c a b i n e t r y and decorative trim exemplify
a r t i c l e s for which the advantages of this i n v e n t i o n are often s o u g h t .
The t h r e e - d i m e n s i o n a l simulation of wood grain in the metal surface may
be accomplished, for example, by embossing, coining, or etching the metal t o
form the grooves and the consequent t h r e a d - l i k e ridges or ties and p l a t e a u s .
6. The grooves and, t h e r e f o r e , the tics and p l a t e a u s are of random length and
width. The depth of the grooves is also not uniform. Although the t i c s a r e
for the most part p a r a l l e l , they and the p l a t e a u s appear to converge and d i -
verge because of the varying lengths and widths of the grooves. Before b e i n g
coated, the minimum depth of the grooves is about 2.2 times the t h i c k n e s s o f
the dry film which is to be deposited from the coating composition. A p a r -
t i c u l a r l y pleasing and r e a l i s t i c e f f e c t is achieved by a p r e f e r r e d a r r a n g e -
ment of the t i c s so that there are from about 80 to about 85 tics p e r
square inch (about 12-13 per square c e n t i m e t e r ) . The average width of t h e
tics in such arrangement is about 16 mils (about 0.4mm) and the average d e p t h
of the grooves is about 5 mils (about 0.13mm).
The bare metal surface is, of course, only suggestive of a wood g r a i n .
It is the t r a n s l u c e n t coating which enables one to complete the e f f e c t by
rubbing and wiping a selected stain over the p a t t e r n . The t r a n s l u c e n t
coating is s u b s t a n t i a l l y c o l o r l e s s and is capable of absorbing a d e c o r a t i v e
stain while s t i l l exposing the color and markings of the s u b s t r a t e . When,
as is usually the case, the color of the metal is not a d e s i r a b l e base f o r
the simulation of wood grain, a pigmented primer is applied to the m e t a l
before the s t a i n a b l e coating is applied. In some i n s t a n c e s , however, t h e
color of the metal, e . g . , copper, bronze and the like, may serve well f o r
special e f f e c t s .
The s t a i n a b l e , t r a n s l u c e n t film is formed on the wood grained s u r f a c e
of the metal by spraying, r o l l e r - c o a t i n g , or applying the aqueous c o m p o s i t i o n
by any other s u i t a b l e method and then drying the composition. The drying tem-
perature may range from just above the. freezing point of the composition t o
just below its decomposition temperature but it is p r e f e r a b l y from about room
temperature to about 350°F (about 177°C). At the p a r t i c u l a r l y p r e f e r r e d
temperature of about 160°F (about 70°C), the film is s u f f i c i e n t l y dry a f t e r
about 10 to 15 minutes; the drying time will be c o r r e s p o n d i n g l y longer a t
lower temperatures and shorter at higher t e m p e r a t u r e s . The film is u s u a l l y
from about 0.5 to about 1 mil thick after drying but it may be thicker i f
d e s i r e d .
The film accepts a decorative stain evenly much like wood does. S t a i n -
ing of the film may be accomplished without runs even when the surface o f
the s u b s t r a t e is v e r t i c a l . Mater-based, alkyd, and o i l - b a s e d stains a r e
readily absorbed.
7. The advantages of this invention are more pronounced when n o n - a b s o r b e n t ,
i . e . water impervious, s u b s t r a t e s such as metal or p l a s t i c are to be deco-
rated by s t a i n i n g but s u b s t r a t e s such as hardboard, p a r t i c l e board, p l a s t e r -
board, and plywood may also be coated with the s t a i n a b l e film of this i n -
vention in order to prepare them for d e c o r a t i v e s t a i n i n g .
The i n v e n t i o n is i l l u s t r a t e d more s p e c i f i c a l l y by the following examples
wherein all p a r t s are by weight unless otherwise s t a t e d . The scope of t h e
invention is not r e s t r i c t e d to the s p e c i f i c d e t a i l s of these examples.
Example 1
A mixture of water (66 p a r t s ) , an anti-foaming agent comprising a non-
ionic s u r f a c t a n t and a s i l i c o n e sold under the trademark NOPCO NXZ(0.2 p a r t ) ,
ethylene glycol (8 p a r t s ) , the quaternary ammonium s a l t of 2-dimethylamino
methyl propanol and d i ( d i o c t y l p y r o p h o s p h a t o ) ethylene t i t a n a t e (1.2 p a r t s ) ,
zinc phosphate having an average p a r t i c l e size of 6 microns and sold under
the product d e s i g n a t i o n J0852 by Mineral Pigments Corporation (175 p a r t s )
is d i s p e r s e d at high speed in a Cowles mixer for 10 minutes. Then 120 p a r t s
of an a c r y l i c l a t e x having a solids content of about 43% by weight, a pH of
9.4 to 10, a v i s c o s i t y at 25°C. of from 500 to 2000 cps. and wherein the
p a r t i c l e size of the a l l - a c r y l i c resin is less than 0.1 micron is added along
with 15 p a r t s of isopropanol and 2 parts of a c r o s s l i n k e d , acidic a c r y l i c
emulsion copolymer as a thickening agent- Ammonium hydroxide (3 parts) i s
added t o a c t i v a t e the thickening agent. The mixture is thoroughly blended
at room t e m p e r a t u r e . The a c r y l i c latex is sold under the trademark Rhoplex
MV-23 by Rohm & Haas.
A s t a i n a b l e film having a porous surface r e s u l t e d when the composition
thus prepared was applied to a s u b s t r a t e and d r i e d .
Example 2
The general procedure of Example 1 is repeated except that the a c r y l i c
latex used is an aqueous emulsion of an a c r y l i c / s t y r e n e copolymer sold by
Polyvinyl Chemical I n d u s t r i e s under the trademark Neocryl A-623 and 10 p a r t s
of butyl c e l l o s o l v e are used in addition to the ethylene glycol. The a c r y l i c
latex has a s o l i d s content of 35% by w e i g h t , a pH of 7.5, and a B r o o k f i e l d
v i s c o s i t y at 25°C. of 320 cps.
8. This composition also provided a s t a i n a b l e , porous film when a p p l i e d
to a substrate and d r i e d .
In contrast to the r e s u l t s of Examples 1 and 2, compositions p r e p a r e d
by the general procedure of Example 2 but s u b s t i t u t i n g an equal weight o f
a finely divided s i l i c a (Imsil A-10, sold by I l l i n o i s Mineral Co.), o r
terra alba (finely divided gypsum), or a finely divided clay for the z i n c
p h o s p h a t e give films having a s e a l t e d surface that do not accept a d e -
corative s t a i n .
Example 3
A mixture of 150 p a r t s of water, 18 parts of ethylene glycol, 1 . 7
parts of the t i t a n a t e coupling agent of Examples 1 and 2, 22 p a r t s o f
butyl cellosolve and 350 p a r t s of calcium carbonate having a mean p a r t i c l e
size of 5.5 microns (sold under the trademark Snowflake White by Thompson,
Weinman,and Company) is ground at high speed in a Cowles mixer. Then, 115
parts of water; 0.5 part of an a n t i - f o a m i n g agent; 120 parts of an a c r y l i c -
latex comprising a low molecular weight terpolymer of a lower alkyl a c r y l a t e ,
a c r y l o n i t r i l e and styrene and having a solids content of about 41% by w e i g h t ,
a Brookfield v i s c o s i t y of from 500 to 2000 cps. and a pH of 7.5; 120 p a r t s
of the acrylic latex of Example 1, 2 parts of a c e l l u l o s i c t h i c k e n e r , and
8 parts of propylene glycol are added and the mixture is thoroughly b l e n d e d
at room t e m p e r a t u r e .
The composition thus prepared is sprayed onto several metal p a n e l s
having a primer coat in place. A film having a thickness of 1 mil (about
25 microns) is formed a f t e r drying at 160°F (about 70"C.) for 12 m i n u t e s
with 10 minutes of flash off t i m e .
A commercial stain is then spread on each panel and wiped in the con-
ventional manner. The s t a i n s used are Formby's gelled s t a i n , C u p r i n o l
stain and wood p r e s e r v a t i v e , Pratt & Lambert P e n e t r a t i n g Rustic S t a i n ,
Olympic (linseed oil base), E n t e r p r i s e 2-in-1, Carver Tripps, and Minwax
stain. Excellent stain r e c e p t i o n is achieved in each case. The impact
strength and adhesion of the film is e x c e l l e n t .
Example 4
The general procedure of Example 3 is repeated except that z i n c
phosphate having an average p a r t i c l e size of 6 microns is used in place of
the calcium c a r b o n a t e .
9. The film deposited on metal panels by the acqueous composition t h u s
p r e p a r e d also showed e x c e l l e n t s t a i n a b i l i t y , impact strength and a d h e s i o n .
In c o n t r a s t to the r e s u l t s of Examples 3 and 4, a film deposited from
a composition prepared by the general procedure of Example 4 except f o r
the replacement of 300 parts of the zinc phosphate by a calcium c a r b o n a t e
having a mean p a r t i c l e size of 2.5 microns showed poor stain r e c e p t i o n .
Example 5
Sheet steel is embossed to achieve a p a t t e r n of generally p a r a l l e l
l i n e s or t i c s of random length to simulate the p a t t e r n of a wood grain. The
wood grain e f f e c t is obtained by an arrangement of individual tics spaced
apart d i f f e r e n t i a l l y so that there are about 80 to 85 tics per square i n c h .
The average width of a t i c i s about 16 mils and the average depth of t h e
grooves between the tics is about 5 m i l s .
A r e s i d e n t i a l steel door is f a b r i c a t e d from the embossed sheet m a t e r i a l
and the surface intended to be the e x t e r i o r face is primed with a pigmented
base coat having a beige c o l o r .
An a c r y l i c latex coating composition is prepared by mixing 12,980 p a r t s
of water, 116.2 parts of the quaternary ammonium salt of 2-dimethylamino-
methyl propanol and d i ( d i o c t y l p y r o p h o s p h a t o ) ethylene t i t a n a t e , and 23,925
p a r t s o f c a l c i u m carbonate having a mean p a r t i c l e size of 5.5 microns f o r
10 minutes in a high speed mixer. Then are added 19,140 parts of an
a c r y l i c / s t y r e n e copolymer l a t e x s o l d b y P o l y v i n y l C h e m i c a l I n d u s t r i e s under
the trademark Neocryl A-623 and which has a resin content of about 35% and
a B r o o k f i e l d v i s c o s i t y at 25°C of 320 cps. An anti-foaming agent (68.3
p a r t s ) comprising a non-ionic s u r f a c t a n t and a s i l i c o n e (sold under t h e
trademark Nopco NXZ), 136.5 parts of a non-ionic s u r f a c t a n t (Tamol 165),
1503 p a r t s of butyl c e l l o s o l v e , 68.3 parts of concentrated ammonium
hydroxice (28% NH3), 34.1 p a r t s of 2 - a m i n o - 2 - m e t h y l - l - p r o p a n o l , 136.1 p a r t s
of a c e l l u l o s i c t h i c k e n e r , 1777 parts of ethylene glycol, 15 parts of a
b a c t e r i c i d e , and an a d d i t i o n a l 8203 p a r t s of water are added and the mix-
ture is thoroughly blended at room t e m p e r a t u r e .
The r e s u l t i n g aqueous coating composition is sprayed onto the embossed
face of the steel door and dried at 160°F (about 70°C) to a t r a n s l u c e n t ,
c o l o r l e s s f i l m .
10. The thus coated face of the door is then stained with a s e m i - t r a n s -
parent o i l - b a s e d stain (Olympic) by the c o n v e n t i o n a l spreading and wiping
technique. An e x c e l l e n t wood-like appearance is achieved upon drying o f
the s t a i n .
In c o n t r a s t to the r e s u l t s in Example 5, the presence of a pigment a t
a low level of c o n c e n t r a t i o n in an aqueous coating composition o t h e r w i s e
corresponding to that of Example 5 caused a pronounced mottled effect on
sheet steel having the simulated wood grain embossed thereon. Use of a
pigment at a c o n c e n t r a t i o n high enough to obscure the mottling r e s u l t e d
in a coating which would not absorb a stain s a t i s f a c t o r i l y .
A clear p r o t e c t i v e top coat may be applied over the stain. The t o p
coating composition may be water-based or o i l - b a s e d .
To those s k i l l e d in the art to which this invention r e l a t e s , many
changes which do not depart from the s p i r i t and scope of this i n v e n t i o n
may suggest themselves. The foregoing d e s c r i p t i o n is purely i l l u s t r a t i v e
and not r e s t r i c t i v e of that s p i r i t and s c o p e .
11. 1. An aqueous composition for forming a t r a n s l u c e n t , stain a b s o r b e n t
film, said composition comprising an a c r y l i c l a t e x , and a w a t e r - i n s o l u b l e
extender pigment having a mean p a r t i c l e size of from about 5 to about 7
m i c r o n s .
2. The composition of claim 1 wherein the weight percent of s a i d
pigment is from about 15% to about 50%.
3. The composition of claim 1 wherein the weight percent of t h e
a c r y l i c resin is from about 10% to about 15% of the t o t a l w e i g h t .
4. The composition of claim 1 wherein the weight r a t i o of s a i d
pigment to the a c r y l i c resin is from about 1.5:1 to about 3 . 6 : 1 .
5. The composition of claim 1 f u r t h e r comprising a t i t a n a t e c o u p l i n g
a g e n t .
6. The composition of claim 5 wherein the amount of coupling agent i s
from about 0.25% to about 0.75% of the weight of the extender pigment.
7. The composition of claim 1 wherein the mean p a r t i c l e size is from
about 5 to about 6 m i c r o n s .
8. The composition of claim 1 wherein the extender pigment is a t
l e a s t one of the class c o n s i s t i n g of calcium carbonate and zinc p h o s p h a t e .
9. The composition of claim 1 wherein the r a t i o of extender pigment
to a c r y l i c resin is from about 2.5:1 to about 3 . 6 : 1 .
10. The composition of claim 5 wherein the t i t a n a t e coupling a g e n t
is a quaternary ammonium s a l t .
11. A t r a n s l u c e n t , s t a i n a b l e coating comprising an a c r y l i c r e s i n
and a w a t e r - i n s o l u b l e extender pigment having a mean p a r t i c l e size o f
from about 5 to about 7 m i c r o n s .
12. The coating of claim 11 wherein the weight r a t i o of e x t e n d e r
pigment to a c r y l i c resin is from about 1.5:1 to about 3 . 6 : 1 .
13. The coating of claim 11 wherein the extender pigment is at l e a s t
one of the class c o n s i s t i n g of calcium carbonate and zinc p h o s p h a t e .
14. The coating of claim 13 wherein the mean p a r t i c l e size of t h e
extender pigment is from about 5 to about 6 m i c r o n s .
15. A method for imparting s t a i n a b i l i t y to a non-absorbent s u b s t r a t e ,
said method comprising coating said substrate with an a c r y l i c latex f i l l e d
with an extender pigment having a mean p a r t i c l e size of from about 5 t o
about 7 microns and in which said latex the r a t i o of extender Figment t o
a c r y l i c resin is from about 1.5:1 to about 3 . 6 : 1 .
12. 16. The method of claim 15 wherein the extender pigment is at l e a s t
one of the class c o n s i s t i n g of calcium carbonate and zinc p h o s p h a t e .
17. A metal a r t i c l e having an i n t e g r a l , t h r e e - d i m e n s i o n a l , s i m u l a t e d
wood grain in its surface and a stainable t r a n s l u c e n t coating over s a i d
simulated wood g r a i n .
18. The metal a r t i c l e of claim 17 c h a r a c t e r i z e d further in t h a t
said t r a n s l u c e n t coating has an absorbed stain t h e r e i n .
19. The metal a r t i c l e of claim 17 wherein the coating comprises a
f i l l e r having an average p a r t i c l e size of from about 5 to about 7 microns.
20. The metal a r t i c l e of claim 17 wherein the coating is a film of a
f i l l e d a c r y l i c resin wherein the f i l l e r / r e s i n r a t i o is from about 1.5:1 t o
about 3.6:1 by w e i g h t .
21. The metal a r t i c l e of claim 19 wherein the f i l l e r is zinc p h o s -
p h a t e .
22. The metal a r t i c l e of claim 19 wherein the f i l l e r is c a l c i u m
carbonate. -
23. The metal a r t i c l e of claim 20 wherein the a c r y l i c resin is a
s t y r e n e / a c r y l i c copolymer.
24. The metal a r t i c l e of claim 17 having a pigmented primer c o a t
under said t r a n s l u c e n t c o a t i n g .
25.. A steel a r c h i t e c t u r a l door c h a r a c t e r i z e d by at least one f a c e
having an embossed surface simulating a wood grain and said surface having
a s t a i n a b l e , t r a n s l u c e n t coating t h e r e o n .
