Protective graft coating for application onto polyurethane for chemical resistance, stain resistance, abrasion resistance and U.V. resistance
This invention relates to a coating comprising prepolymer and monomers for application onto polyurethane for chemical resistance, abrasion resistance, water proof etc. Usually polyurethane is porous and does not have sufficient stain, abrasion and chemical resistance. The said coatings developed using technology of chemical grafting that involves the use of prepolymers, monomers, catalyst, graft initiator, wetting agents, fillers and other ingredients of the composition. The coating thus obtained when applied on the polyurethane allows obtaining graft polymerization, thereby forming a polymeric film chemically attached to the substrate. The polyurethane substrate is reacted with craft initiator which creates the reaction sites on the substrate via free radical mechanism. This in turn renders the substrate receptive to attachment of monomers/prepolymers forming polymeric film that is chemically bonded to the substrate which has then the desired property in terms of stain resistance, abrasion wear, crock, water, chemical resistance and other properties.
1. A method of grafting a coating onto a substrate comprising:
a) preparing a mixture of:
a solvent including water,
(ii) a UV resistant compound,
(iii) a surfactant,
(iv) a monomer,
(v) a urethane prepolymer,
(vi) Fluoroethylene-alkyl vinylether (FEVE) alternating copolymer and
(vii) a graft initiator
to define an admixture of monomers and prepolymers, and
(c) applying the admixture onto the substrate.
2. The method of claim 1 wherein said admixture is sprayed onto said substrate.
3. The method of claim 2 further comprising drying said sprayed admixture for about 10 to 15 minutes and subjected to a cure of 125 to 150 degrees centigrade for about 5 to 10 minutes.
4. The method of claim 3 wherein said admixture comprises a first component that has a functional group for reaction and covalent bonding with an active site for the substrate.
5. The method of claim 4 wherein the first component is a water dispersible polymer.
6. The method of claim 5 wherein said water dispersible polymer comprises an epoxy prepolymer, a urethane prepolymer and an acrylic prepolymer.
7. The method of claim 6 wherein said water dispersible polymer includes at least one functional group selected from carboxyl, hydroxyl, epoxy, amino, melamine, acrylic group and fluoro group.
8. The method of claim 1 wherein said monomer is selected from the group consisting of acrylate, methacrylate, or urethane acrylate.
9. The method of claim 1 wherein said graft initiator is a metallic salt.
10. The method of claim 9 wherein said metallic salt is selected from the group consisting of silver nitrate, silver perchlorate, ferrous ammonium sulfate, and silver acetate.
11. The method of claim 10 including a catalyst selected from the group consisting of peroxide of urea, hydrogen, and benzoyl.
12. The method of claim 1 wherein the solvent includes butyl carbitol.
13. The method of claim 1 wherein the admixture composition comprises:
PARTS BY
FORMULATION
WEIGHT
Bulyt Carbitol
40.00
ethyl 3-ethoxy propionate Solvent
20.00
Antioxidant pentaerythritol tetrakis[3-[3,5- di-tert-
0.08
butyl-4-hydroxyphenyl]propionate]
UV absorber
0.08
Non ionic surfactant
2.00
octophenolpoly(ethyleneglycolether)
3,4-(epoxycyclohexyl)ethyltriethoxysilane
8.00
Water
320.00
Silica Flattening Agent
16.00
Silica modified Acrylic dispersion mixture of acrylic
200.00
polymers 18-19% , residual monomers <500 ppm,
water 74-77% and amorphous silica 5-8%
Urethane Prepolymer
120.00
Fluoroethylene-alkyl vinylether (FEVE) alternating
160.00
copolymer
modified poly vinylidene fluoride dispersion
160.00
fluoro emulsion
24.00
polyterafluoroethylene dispersion
20.00
50% in water
Melamine Prepolymer
24.00
Ethoxylated(15)trimethylolpropanetriacrylate
4.00
Dodecyl Benzene Sulfonic Acid catalyst
1.00
Urea Peroxide 1.00% Solution in Water
0.20
Silver Perchlorate 0.1% Solution in Water
0.2.
14. The method of claim 1 wherein the admixture composition comprises:
PARTS BY
FORMULATION
WEIGHT
Bulyt Carbitol
10.00
ethyl 3-ethoxy propionate Solvent
5.00
pentaerythritol tetrakis[3-[3,5- di-tert-butyl-4-
0.20
hydroxyphenyl]propionate]
UV absorber
0.20
Non ionic surfactant octophenolpoly
0.50
(ethyleneglycolether)
3,4-(epoxycyclohexyl)ethyltriethoxysilane
2.00
vinyltrimethoxysilane
0.50
Silica Flattening Agent
5.00
mixture of acrylic polymers 18-19%, residual
54.00
monomers <500 ppm, water 74-77% and
amorphous silica 5-8%
Fluoroethylene-alkyl vinylether (FEVE) alternating
55.00
copolymer
modified poly vinylidene fluoride dispersion
30.00
mixture of acrylic polymers 18-19% , residual
04.00
monomers <500 ppm, water 74-77% and amorphous
silica 5-8%
polyterafluoroethylene
10.00
dispersion 50% in water
Melamine Prepolymer Methylated melamine
06.00
formaldehyde resin
Water
80.00
Ethoxylated(15)trimethylolpropanetriacrylate
4.00
Fluoro Emulsion fluoro surfactant
10.00
Urea Peroxide 1.00% Solution in Water
0.20
Silver Perchlorate 0.1% Solution in Water
0.20.
15. The method of claim 1 wherein the admixture composition comprises:
PARTS BY
FORMULATION
WEIGHT
Bulyt Carbitol
10.00
Antioxidant pentaerythritol tetrakis[3-[3,5- di-tert-
0.08
butyl-4-hydroxyphenyl]propionate]
UV absorber
0.08
Non ionic surfactant octophenolpoly
2.00
(ethyleneglycolether)
3,4-(epoxycyclohexyl)ethyltriethoxysilane
8.00
Dispersing Agent
2.00
Water
320.00
Silica Flattening Agent
16.00
mixture of acrylic polymers 18-19% , residual
20.00
monomers <500 ppm, water 74-77% and
amorphous silica 5-8%
Urethane acrylic prepolymer
40.00
Fluoroethylene-alkyl vinylether (FEVE)
80.00
alternating copolymer
2% Solution of fluoro surfactant in Water
2.00
Acrylic fluoro emulsion
24.00
polyterafluoroethylene dispersion 50% in
10.00
water
Melamine Prepolymer fluoro dispersant
20.00
Methylated melamine formaldehyde resin
Urethane Acrylate SR 9035 monomer
4.00
Urea Peroxide 1.00% Solution in Water
0.20
Ferrous Ammonium Sulfate 0.1% Solution in
0.20.
Water