CA1062559A

CA1062559A - Process for decorating heat-stable polymer coating compositions

Info

Publication number: CA1062559A
Application number: CA236,324A
Authority: CA
Inventors: Eustathios Vassiliou
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1974-09-27
Filing date: 1975-09-25
Publication date: 1979-09-18
Also published as: NL181719C; DE2543026A1; NL7511388A; FR2286010B1; GB1495687A; JPS5912350B2; JPS5160244A; BR7506250A; FR2286010A1; DE2543026C2; NL181719B; ES441327A1; IT1042911B

Abstract

A PROCESS FOR DECORATING
HEAT-STABLE POLYMER COATING COMPOSITIONS

ABSTRACT OF THE DISCLOSURE:
The appearance of a heat-stable polymer coating is enhanced by a process which produces a decorative pattern within a heat-stable polymer coating. The process consists essentially of applying, in a decorative pattern, an oxida-tion catalyst composition which diffuses into the heat-stable polymer coating composition and renders the pattern visible, upon baking, within the baked coat produced by the coating composition.

Description

1~6Z559 BACKGROUND OF THE INVENTION
-Fleld of the Invention Thls invention relates to a process which renders a decorative pattern visible within a heat-stable polymer coating.
Prior Art Articles coated with heat-stable polymer composl-tions of varlous types have come into widespread use in recent years. Heat-stable polymer coated articles are useful for purposes requiring or aided by a heat-stable surface. Espe-cially useful are heat- table polymer coating compositions which provide lubriciou~ surfaces. The uses of coated articles having lubricious surfaces range from bearings to ship bottoms and from iron soleplates to ice cube trays.
To achieve maxlmum consumer demand for an artlcle consumer expectations must be met. One consumer expectation : 1B to have a product whlch is pleasing to his or her aesthetic sense and which is capable of maintaining this pleasing effect throughout the product's useful life.
The process of this lnvention produces a decoratlve pattern visible within coatings produced by a heat-stable polymer coating compositlon. By decorative pattern is meant any image, picture, design, configuration, or illustration which can be formed by any conventional method of applying i~.
Decorative areas of the coating wear as well as non-decorative areas for the following reasons. The decorative pattern extends through the entire thlckness of the coating;
therefore as the coating ls worn thinner the decorative pattern ls ~till present. Concentration of heat-stable polymer ls

-2- ~u~
q~

~06ZS59 unlform throughout the coatlng, l.e., the decoratlve and non-decorati~e areas; therefore, the coatlng ha~ unlform heat stabillty throughout. Thicknes~ of the coatlng is uniform,i.e., neither the decorative nor non-decorative areas are higher than the other, thereby not facilitating chipping of a higher area.
SUMMARY OF THE INVENTION
.
According to the present invention there is provided a process which renders a decorative pattern visible within a baked coating produced by a heat-stable polymer coating composi-tion. The process consists essentially of applying the heat-stable polymer coating composition either as a subsequent coat over or directly under an oxidation catalyst composition which is arranged in a decorative pattern, wherein the oxidation cata-lyst or its decomposition or oxidation products diffuse into the coat and either by rea~ting with components of the coating, by catalyzing react~ons within the coating or by itself renders, upon baking, the decorative pattern visible within the coating produced by the heat-stable coating composition.
DETATT~D DESCRIPTION OF T~E rNVENTION
_ A heat-stable polymer composition consists of at least a heat-stable polymer and a liquid carrier.
A heat-stable polymer is a polymer which is not affected by temperatures above 300C which would decompose, oxidize or otherwise adversely affect most organic compounds.
Some examples of heat-stable polymers are silicones, poly-~ulfides, polymerized parahydroxy benzoic acid, polysulfones, polyimides, polyamides, polysulfonates, polysulfonamldes, H-resins (sold by Hercules Corporation), and fluorocarbons.
One or more heat-stable polymer~ can be present in the composition.
The preferred heat-stable polymers are fluoro-carbons because of thelr high temperature stabillty and release properties. The fluorocarbon polymers used are those of hydrocarbon monomers completely substituted with fluorine atoms or a combination of fluorine and chlorlne atoms. Included in this group are perfluoroolefin polymers such as polytetrafluoroethylene (PTFE) and copolymers of tetrafluoroethylene and hexafluoropropylene in all monomer unit weight ratios, fluorochlorocarbon polymers such as poly-monochlorotrifluoroethylene, and copolymers of tetrafluoro-ethylene and perfluoroalkyl vinyl ethers. Mixtures of these can also be used.
The heat-stable polymer is ordinarily present in the composition at a concentration of 25% through 95%, pre-ferably 70% through 90~,~by weight of the total solids present in ~he composition.
Although Q dry flour or powder of a heat-stable poly-mer can be used and a liquid carrier provided separately, a ~0 polymer ln the form of an aqueous surfactant-stabilized dis-persion is preferred for its stability and because it is most easily obtained in that form. Dispersions of heat-stable polymers in organic liquids such as alcohols, ketones, aliphatics or aromatic hydrocarbons, or mixtures of these, can also be used. In either case, the liquid generally serves as the carrier for the composition.
If desired a colorant may be present in the heat-stable polymer compositlon.
A colorant is any compound which changes color when ~0 oxidized. Carbon and carbonaceous residues are examples of ~ ~062559 colorants.
For the purpose of thi~ lnvention a reaction such as oxldation of carbon black to carbon dioxide, in which a solid is oxidized to a fugitive gas, the solid thereby vanish-lng from the composition, is considered a color change.
Carbon can be present in concentrations up to 40%
based on the weight of total solids of the composition, pre-ferably in concentrations of .5-10%.
Carbonaceous residues are produced by decomposition or partial oxidation of organic compounds, which includes organometallic com~ounds. Organic compounds are normally present in coating compositions to serve as dispersants, coalescing agents, vis~osity builders, etc. or they can be added to serve as colorants.
Although absolute amounts of carbonaceous residues in the heat-stable polymer coating are usually extremely small, nevertheless, they give a definite coloration to a baked coat-ing.
Examples of organic compounds which produce carbon-aceous residues are polymers of ethylenically unsaturatedmonomers, which depolymerize, and whose depolymerization products vaporizej in the temperature range o~ from 150C
below the fusion temperature to about the heat-stable polymer~s decomposition temperature.
"Depolymerization" means degradation of a polymer to the point at which the degradatlon products are volatile at the temperature encountered in curing the coat. The degrada-tion products can be monomers, dimers or oligomers.
"Vaporize" means volatilizatlon of the degradatlon products and their evaporation from the fllm.

Usually the polymers of ethylenically unsaturated monomers contain one or more monoethylenically unsaturated acid unlts.
Representative of these ethylenically unsaturated monomers are alkyl acrylates and methacrylates having 1 to 8 carbon atoms in the alkyl group, styrene, 2-methyl styrene, vinyl toluene and glycidyl esters of 4 to 14 carbon atoms.
Representatlve of the monoethylenically unsaturated acids are acryllc acid, methacrylic acid, fumaric acid, itaconic acld and maleic acid (or anhydride).
The polymer of an ethylenically unsaturated monomer which produces a carbonaceous residue can be present as a coalescing agent in the composition at a concentration of about ~% through 60~o by weight of total heat-stable polymer and residue producing polymer.
The heat-stable polymer composition may contain an antioxidant. An antioxidant is any compound that opposes oxidation under fabrication baking conditions which are required for manufacture of heat-stable polymer coated articles. The antioxidant can oppose oxidation either by itself or through its decomposition or oxidation products.
All of these compounds should yield at least .01 part by weight, ~ased on so~ids and expressed as the acid, of the corresponding free acids or anhydrides when the compound is decomposed and/or oxidized during fabrication baking. The preferred yield range is .1 to 1 part by weight.
The preferred antioxidants are compounds containing phosphorus, sulfur, boron, or any combination of the above.
The most common examples include the ortho- meta-, pyro-acids; neutral and basic salts; esters and generally theirorganic derivatives including organometallic derivatives.

1(~6Z559 More preferred antioxidants are phoephoric acid, its decomposable salt~ containing ammonia or amines, 2-ethyl-hexyldiphenyl phosphate, magnesium glycerophosphate, calcium glycerophosphate, and iron glyceropho~ph~te.
The heat-stable polymer composition can be pigmented or unpi~mented. Any plgment or combinatlon of pigments ordinarily used in this sort of composition can be used.
Typical of these pigment~ are titanium dioxide, aluminum oxide, silica, cobalt oxideJ iron oxide, etc. The total amount of pigment ordinarily present is at a concentration of up to 40%
by weight of the total solids in the composition.
The heat-~table polymer compo~ition may contain mica particles, mica particle~ coated with pigment, and glass and metal flakes. These particle~ and flakes have an average longest di~ension o~ 10 to 100 microns, preferably 15-50 microns, with no particle~ or flakes havlng a longest dimension of more than about 200 microns. Particle and flake Bize i~ measured optically against a standard.
The mica particles coated with pigment preferred for use are those described in U.S. Patent 3,087,827 granted to Klenke and Stratton, and U.S. Patents 3,087,828 and

3,087,829 granted to ~inton.
The mica particles described in these patents are coated with oxides or hydrous oxides of titanium, zirconium, aluminum, zinc, antimony, tin, iron, copper, nickel, cobalt, chromlum, or vanadium. Titanium dioxide coated mica is preferred because of its availability. Mixtures of these coated micas can al~o be u~ed.

Representative of metal flake which can be ~ed are aluminum flake, stainless steel flake, nickel flake, and bronze flake. Mixtures of flake can also be used.
The mica particles, coated mica particles, or glass and metal flake are ordinarily present in coating compositions at a concentration of about 0. 2-2~/o~ by weight of total solids.

The composltion can also contaln such conventional additives as flow control agents, surfactants, plasticizers, coalescing agents, etc., as seem necessary or desirable.
These additives are added for reasons, ln ways and in amounts known to artisans.
The amount of total solids in the composition will be governed by the substrate to which the composition is to be applied, method of application, curing procedure, and like factors. Ordinarily, the compositlon wlll contaln 10%
through 80% by weight of total solids, but preferably 30-50%.
The oxidation catalyst composition must include an oxidation catalyst and can include color enhancers, viscosity bullders or thlckeneræ, wetting agents, inert pigments, decom-~osable resins and polymers, heat-stable resins and polymers neutralizers, liquid carriers, and other ad~uncts.
Color enhancers are heat-unstable organic compounds which decompose to produce colorants thus enhancing the con-trast between decorative pattern and background. Examples of color enhancers are sugar, styrene, starch, fatty acid, and glycerides.
~ olytetrafluoroethylene and other heat-stable poly-mers are examples of viscosity builders or thickeners. Pre-ferably the same heat-stable polymer utilized in the coating composition is utilized as the viscosity builder or thickener.

Example~ of pigment are carbon black, iron oxide, tltanlum dioxide and cobalt oxide. When plgment is present ln the oxldation catalyst composition, at least an equal amount, preferably three to ten times as much, of heat-stable polymer will, preferably, also be present.
The oxidatlon catalyst composition can contain one or more oxidation catalysts.
An oxidation catalyst is a compound which promotes oxldation under the baking conditions required for fabrication lo of coated articles. The oxidation catalyst can promote oxida-tion eitheritself or through its decomposition or oxidation products. The oxidation catalyst causes the decorative pattern to be rendered vlsible, upon baking, either by react-~ng with the components of the coating, or catalyzlng reactions wlthin the coating or by adding color ltself.
Included in this class of compounds are compoundæ
containlng:one or more of the followlng:
chromlum manganese copper bismuth cobalt cadmlum lron molybdenum nickel tin vanadium tungsten tantalum lithium cerlum ~odium thorium potassium calcium lead zinc.

106Z55~

Preferred compounds are those which are produced by reaction of a metal from the following 11st (1) with an acid to form a salt compound of list (2).
(1) Metals bismuth lead cerium manganese cobalt nickel iron (2) Salts lo acetate octoate caprate oleate caprylate palmitate lsodecanoate ricinoleate linoleate soyate naphthenate stearate nltrate tallate.
More preferred oxldation catalyst compounds are:
cobalt octoate cerium octoate manganese octoate iron octoate bismuth octoate nickel octoate lead octoate.
An oxidation catalyst can also be present withln the heat-stable polymer coating composition. The oxidation catalyst of the coatlng composition can either be the same or different from the oxidation catalyst used in the oxidation catalyst composition.

_ 10 _ The oxidation catalyst composition can be applied by any conventional method of applying ink. The preferred methods are to apply the oxldation catalyst composition by "lntaglio"
o~rset, e.g., uslng a Tampoprint~ machine sold by Dependable Machine Co., Inc., or slik screening.
The oxidation catalyst is dissolved or dispersed in suitable carriers for the particular oxidation catalyst.
The percentage range by weight of metal content to the total weight of oxidation catalyst plus carrier depends on the oxidation catalyst's formulation and application method.
The preferred percentage range is 1-20%, although lower than 1% and higher than 20~ concentration can also be used depend-ing on the coating methods and conditions, baking methods and conditions,- as well as characteristics of the oxidation catalyst.
The baklng temperature range of the process is dependent mainly upon whlch heat-stable polymer compositlon 18 utilized. The process of this inventlon 18 utilizable upon any conventionally used substrate. The substrate may be coat-ed with a primer prior to the applica~ion of the oxidationcatalyst composition. The substrate is preferably pretreated prior to the application of any coating composition. Pre-treatments methods include flame-spraying~ frit-coating, grit-blasting, and acid- or alkali-treating. A metal substrate is preferably pre-treated by grit-blasting, by flame-spraying of a metal or a metal oxide, or by frit-coating, although the compositions can be applied successfully to phosphated, chromated or untreated metal. A glass substrate i~ prefer-ably grit-blased or frit-coated.

1062~S9 A primer composition, if desired) can be applled elther under or over the oxidation catalyst composition. The prlmer compositlon can be applied ln any of the customary ways, which lnclude spraying, roller co~tlng, dipplng, and doctor blading. Spraying i~ generally the method o~ choice.
The primer compo~ition can be any conventionally used primer coating, for example, a silica-perfluorocarbon primer.
m e coating composition i5 applled to a thickness of about 0.5-5 mils (dry) and baked for a time and at a tempera-ture sufficient to fu6e or cure the heat-stable polymer being U8 ed.
Included ln the proceæs are varlous ~equences of applying the varlous composltions, i.e., the prlmer compo-sition, coatlng compositlon, and oxldation catalyst compo-sition, to the substrate, ~or example, (l) first the oxldation catalyst compo-sltion, and then the coating composition;
(2) first the coating composition, and then the oxidation catalyst composition, (3) ~irst the primer composition, then the oxidation catalyst composition, and then the coating composition;

(4) flrst the oxidation catalyst composition, then the primer composition, and then the coating composition; or ( 5) fir t the prlmer compos~tion, then the coating composition, and then the oxldation catalyst composition.

The process and composltion of this invention are use~ul ~or any artlcle that may use a heat-stable polymer surface; example6 are cookware, especlally fry pan~, bearings, valves, wlre, metal foil, boilers, plpes, ship botto~s, oven liner~, iron soleplates, wa~fle irons, ice cube trays, snow shovels, sa~s, flles and drills, hoppers and other industrlal containers and ~olds.
m e following example is illustratlve of the invention. All parts are on a weight bagis unless otherwlse stated.

Five aluminum panels were grit-blasted with 80 mesh alumlna grit at 5.62 kgs/cm2 (kilograms per ~quare centimeter).
A silica-fluorocar~on primer was prepared as follows:
(a) Mix together parts by weight polytetra~luoroethylene (PTFE) aqueous-di~persion, 60~
sollds 478.76 parts delonlzed water 130.23 parts colloidal silica sol, 30% solids in water (LUDOX
AM~ in colloldal sllica, sold by E. I. du Pont de Nemours and Company) 327.18 parts (b) Separately mix TRITON X-100*
(isooctylphenoxypolyethoxyethane nonlonic surfactant sold by Rohm and Haas Co.)17.52 parts toluene 34.56 parts 3 * denotes trade mark A

Parts by weight butyl carbitol (diethylene glycol monobutyl ether acetate) 13.36 parts silicone ~olution (DQW Corning DC-801* sillcone 60~ solids ln xylene) 34.56 parts 85.52 parts of (b) were added to (a) in a ~mall ~tre~m, with stlrring, over a 2-3 mlnute period. To this were 10 added, with stirring, tltanium dioxlde disper~ion (45% solids dlsperslon in ~ater)35.46 part~ by welght ch~nnel black dlsper~ion (22% solid~ disper~ion ln water).05 part by weight.
Stirring was continued for 10-20 mln~te~.
m e prlmer w~s ~prayed o~to all flve grit-blasted alu~nu~ panels to a thickne~s of 0.3 ~le (dry) and dried in air.
me following oxidation catalyst compositio~s were stamped onto each of the five alumlnum panels, using a sepa-rate stamp for each oxidat~on catalyst co~position. The oxida-tion catalyst compo6ition~ were:
(1) cerlum octoate ln 2-ethyl hexanoic acld (12% metal content by weight) (2) cobalt octoate in mineral spirits (1?% metal content by weight) (3) calcium octoate in 2-ethyl hexanoic acid (5% metal content by ~elght) * denotes trade mark - 14 _ ~0 6 ZSS 9 (4) bismuth octo~te in 2-ethyl hexanoic acid (85% metal content by weight)

(5) manganese octoate in mineral spirits (6.0% metal content by weight)

(6) iron octoate in 2-ethyl hexanoic acid (10.5% metal content by weight) Five fluorocarbon coating compositlon~ were prepared.
The coating compositions differed in that each contained a dl~ferent oxidatlon cataly~t composition.
The oxidation catalyst composition utilized in the five coating compositions were as follows:
(1) 3.04 parts by wel~ht of cerium octoate in 2-ethyl hexanoic acid (12% metal content by weight).
(2) 3.04 parts by weight of cobalt octoate in mineral ~pirits (12~ metal content by weight).
(~) 4.25 parts by weight of bismuth octoate in 2-ethyl hexanoic acid (8.5% metal content by weight).
(4) 6.14 parts by weight of manganese octoate in mineral splrits (6.o% metal content by welght).
(5) ~.07 parts by weight of iron octoate in 2-ethyl hexanoic acid (10.5% metal content by weight).

The ~luorocarbon topcoats were prepared as follows:
(a) Prepare a mill base by mixing in order and pebble milling:

106Z5.~,i9 Parts b~ weight tltanium dioxide 360.00 part~
triethanolamine 53.28 parts olelc acid 26.72 parts deionized water 360.00 parts (b) Wlth mixingJ add 718.04 part~ by ~eight of ~1~ dls-persion (Du Pont TE-30*) to 97.89 part6 by weight o~ the product of (c).
(c) Mix:
triethanolamlne 26.76 parts by welght oleic acid 16.68 parts by weight toluene 56.04 parts by weight butyl carbitol 18.79 parts by weight oxidation catalyst (the metal octoate in composition the amount stated above).
(d) Slowly add the product of (c) to the product of (b) with mixing.
(e) Slowly add, with mlxing, 625.8 parts by welght of an aqueous dlspersion, 40% solids, of a ~ethyl meth-acrylate/ethyl acrylate/methacrylic acid polymer hav-ing a monomer welght ratio of 39/57/4 to the product Or (d)~
(f) Slowly add, with mixing, 39.3 partQ by weight water to the product of (d).
m e five different fluorocarbon coating co~positions were sprayed, one per each panel, onto the five panels to a thickness of 0.7 mll (dry) and dried in air.
The air dried panels were baked at 430C. ~or five mlnutes.
m e results are contained in the following chart.

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~ ~3 o ~: o~ ~ ~ m u~ ~ u~ ~ ~ R h ¢ ~! E :~ ~
[~ O O .C q~ s~ ,I h S~
~ ~;C~ v ~ ~ h ~ ~ ~) h E~ 3 ~ ~3 o6 1 ~ S X tYD,C ~ .~C
:,, ~ o8 m ~ ~ . ~ ~
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~!o v ~ ~ ~ s~ :~ ~ ~i o~ ~ ~ ~ C~c ~ ~ ~x :~. ~ ~
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3 ~ E~ ~ c~ 8 ~ ~ ~ h ~ 1~ ~ O ~ :~
W u~ ~1 ~
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~¢~ ~ h~ ~1 ~ h S~ q~ ~ S~
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m~ m ~ ~ o o ~ ~
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a E~ o ~ ~ o fi b0 ~: .1 O Z H h . rl 0 ~: O ~
E~8 v v v 0 m ~ h 0 . -a~

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~062559 Frit-coat an aluminum panel. Prime coat the aluminum panel as in Example 1.
Prepare an oxidation catalyst composition con-sisting of:

60% by weight cobalt octoate in mineral spirits (12% metal content by weight) 40% by weight Oleic acid Prepare a coating composition as follows:
(a) Add slowly 110.66 parts ~y weight of deionized water to 657 parts by weight of an aqueous dispersion of polytetrafluoroethylene containing 6% by weight isooctylphenoxypolyethoxy-ethanol;
(b) Add slowly, with stirring, to the product of (al 115.75 parts by weight of an aqueous dis-persion, 40/O solids, of a methyl methacrylate/
ethyl acrylate/methacrylic acid te,rpolymer having a monomer weight ratio of 39/57/4;
(c) Prepare a black mill base by mixing and then pebble milllng:
Carbon - 20 parts by wt.
Aluminosilicate pigment - 10 parts by wt.

Sodium polynaphthalene sulfonate - 3 parts by wt.
Water (deionized) - 67 parts by wt.
(d) Prepare a titanium dioxide dispersion by mixing and then pebble milling:
Titanium dioxide - 45 parts by wt.
Water (deionized) - 54.5 parts by wt.

Sodium polynaphthalene sulfonate - .5 parts by wt.

! ' (e) Prepare a cobalt oxide dispersion by mixing and then pebble milling:
Cobalt oxide - 45 parts by wt.
Water (deionized) - 55 parts by wt.
(f) Add slowly, with stirring and in order, to the product of step (b):
Black mill base - 10.72 parts by wt.

Titanium dioxide dispersion - 81.21 parts by wt.

Cobalt oxide dispersion _ 9.74 parts by wt.
(g) Prepare a solvent-surfactant by mixing:
Triethanolamine - 25.88 parts by wt.
Toluene - 46.36 parts by wt.
Butyl carbitol - 15. 63 parts by wt.
Oleic acid - 12.13 parts by wt.
(h) Add slowly, with stlrring, 109.83 parts by weight of the solvent-surfactant of (g) to the product of (f).

(i) Prepare a composition consisting of 1 part by weight of phosphoric acid (85%~l per 5 parts by weight of triethanolamine.
(j) Add a sufficient amount of the phosphoric acid composition of (i) to the product of ~h) to produce a coating composition containing 2% phos-phoric acid composition.
Stamp the oxidation catalyst composition in a decorative pattern upon the aluminum panel.
Spray the coating composition onto the panel to a thickness of 0.7 mil (dry). Dry the panel in air.
Bake the air-dried product 430C for 5 minutes.
The area of the coating over the oxidation catalyst composition ' 106Z559 becomes considerably lighter, while the other areas of the coating maintain their hue, thereby producing a light decorative pattern upon a gray background.

Frit-coat and prime coat three aluminum panels as in Example 2.
Prepare three oxidation catalyst compositions as follows:
(a) Cerium octoate in 2-ethylhexanoic acid (12% metal content by weight), (b) Manganese octoate in mineral spirits (6~0~o metal content by weight);
(c) Bismuth octoate in 2-ethylhexanoic acid (8.5% metal content by weight).
Stamp one of the oxidation catalyst compositions in a decorative pattern upon each of the three aluminum panels.
Spray the coating composition of Example 2 onto each panel to a thickness of .7 mil (dry).

Dry the panels in air.
Bake the air-dried panel at 430C for 5 minutes.
The areas of the coatings over the oxidation catalyst compositions become considerably lighter, while the other areas of the coatings maintain their hue, thereby producinga light decorative pattern upon a gray background.

Prepare the coating compositions of Example 2.
To 100 parts of the coating composition add 3.6 parts of TiO2 coated mica particles (Afflair~ NF-152-D

sold by E. I. du P~nt de Nemours and Company).

Prepare a primer composition by mixing together the following:
PARTS BY
WEIGHT
Deionized water 154.11 Aqueous dispersion of PTFE, 60% by weight solids 1105.03 Colloidal silica sol (Ludox~ AM
sold by E. I. du Pont de ~emours and Company) 761.56 Toluene 112.25 Diethylene glycol mono-butyl ether 26.50 Silicone (60% by weight solids in xylene) 67.20 Triethanolamine 22.65 Oleic acid 11.32 White mill base 45% mill base 54.5% demineralized water .5% sodium polynaphthalene sulfonate 166.50 Prepare four aluminum panels by frit-coating.
Spray the primer composition to a thickness of .3 mil (dry) and dry in air.
Prepare the following four oxidation catalyst compositions:
(a) 60% by weight cobalt octoate in mineral spirits (12% metal content by weight) 40O/o by weight oleic acid (b) Cerium octoate in 2-ethylhexanoic acid (L2% metal content by weight) (c) Manganese octoate in mineral spirits (6.0% metal content by weight) (d) 1.5 parts cerium octoate in 2-ethyl-hexanoic acid (12% metal content by weight) `` ' 10~

.5 part - 60% by ~eight cobalt octoate in mineral spirits (l~/o metal content by weight) ~ 40% by weight oleic acid Stamp one of the four different oxidation catalyst compositions in a decorative pattern upon each of the four aluminum panels.
Spray the coating composition onto each panel to a thickness of .7 mil (dry) and dry in air.
Bake the air-dried panels at 430C for 5 minutes.
The area of the coatings over the oxidation catalyst composition becomes lighter, while the other areas of the coating maintain their hue, thereby producing a light decorative pattern upon a gray background.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A process for decorating heat-stable polymer coatings, the process consisting essentially of applying a heat-stable polymer composition either directly under or as a subsequent coat over an oxidation catalyst composition dispersed or dissolved in a carrier, said oxidation catalyst composition being arranged in a decorative pattern; wherein the oxidation catalyst or its decomposition product diffuses into the heat-stable coating composition and either by reacting with the heat-stable coating composition by catalyzing reactions with the heat-stable coating composition or by itself renders, upon baking, the decorative pattern visible within the heat-stable polymer coating; said heat-stable polymer composition comprising a heat-stable polymer that is stable at temperatures above 300°C
and a liquid carrier.

2. The process of Claim 1 wherein the oxidation catalyst is a compound or mixture of compounds containing one or more of the following:
.

3. The process of Claim 1 wherein the oxidation catalyst composition contains a compound or mixture of compounds produced by reaction of a Metal from list (1) with an acid to form a salt compound of list (2)

4. The process of Claim 1 wherein the oxidation catalyst composition contain one or more of the following compounds:

5. The process of claim 1 wherein the oxidation catalyst composition further consists of color enhancers, viscosity builders or thickeners, wetting agents, pigments, decomposable resins and polymers, heat-stable resins and polymers, neutralizers, liquid carriers or mixtures of the above.

6. The process of claim 1 wherein the heat-stable polymer composition consists essentially of (a) heat-stable polymer, said polymer being silicone, polysulfide, polymerized parahydroxy benzoic acid, poly-sulfone, polyimide, polyamide, polysulfonate, polysulfonamide, fluorocarbon or mixtures of the above; and (b) a liquid carrier.

7. The process of claim 6 wherein the heat-stable polymer is derived from an ethylenically unsaturated fluorocarbon monomer.

8. The process of claim 6 wherein the heat-stable polymer is derived from an ethylenically unsaturated hydrocarbon monomer completely substituted with fluorine atoms or a combination of fluorine atoms and chlorine atoms.

9. The process of claim 6 wherein the heat-stable polymer is polytetrafluoroethylene, copolymer of tetrafluoroethylene and hexafluoropropylene or mixtures of the above.

10. The process of claim 6 wherein the heat-stable polymer composition contains a colorant.

11. The process of claim 10 wherein the colorant is carbon black, a carbonaceous residue, or a mixture thereof.

12. The process of claim 6 wherein the heat-stable polymer composition contains an oxidation catalyst or mixture or oxidation catalyst containing one or more of the following:

.

13. The process of Claim 6 wherein the heat-stable polymer composition contains oxidation catalyst selected from a compound or mixture of compounds produced by reactions of metal from list (1) with acids to form salt compounds of list (2):

14. The process of Claim 6 wherein the heat-stable polymer composition contains one or more of the following oxidation catalyst:

15. The process of Claim 6 wherein the heat-stable polymer composition contains an oxidation catalyst and a colorant.

16. The process of claim 6 wherein the heat-stable polymer composition contains an antioxidant;
wherein the antioxidant is a compound con-taining phosphoric, sulfur, boron, or combination thereof.

17. The process of claim 16 wherein the anti-oxidant is phosphoric acid, its decomposable salts containing ammonia or amine, 2-ethylhexyldiphenyl phosphate, magnesium glycerophosphate, calcium glycerophosphate, iron glycero-phosphate, or mixtures thereof.

18. The process of claim 6 wherein the heat-stable polymer composition contains antioxidant and colorant.