Claims
- 1. A process for providing a polycarbonate substrate with an abrasion and chemical solvent resistant thermoset organopolysiloxane coating consisting essentially of: (i) priming at least one surface of said substrate by applying onto said surface a primer composition consisting essentially of a thermoplastic acrylic polymer containing functional groups, said functional groups being selected from the group consisting of hydroxyl, carboxyl, amine, epoxide, amide, --SH, --SO.sub.3 H, --COOR, --Si(OR.sup.1).sub.3, and mixtures thereof wherein R and R.sup.1 are alkyl radicals containing from 1 to about 20 carbon atoms, and a solvent for said acrylic polymer; (ii) evaporating off the solvent from said primer composition thereby forming a solid primer layer consisting essentially of a thermoplastic acrylic polymer containing functional groups; (iii) applying onto the primer layer a top coat composition consisting of a solvent-soluble further-curable organopolysiloxane and a solvent therefor; (iv) evaporating off a substantial amount of the solvent in the top-coat composition; and (v) curing said further-curable organopolysiloxane thereby forming a hard, abrasion and chemical solvent resistant top-coat consisting of a thermoset organopolysiloxane which is tenaciously and durably adhered to the polycarbonate substrate.
- 2. The process of claim 1 wherein said thermoplastic acrylic polymer containing functional groups is the polymerization product of at least one monomer represented by the general formula CH.sub.2 .dbd.CY--COOR.sup.2 and at least one monomer represented by the general formula CH.sub.2 .dbd.CY.sup.1 --COOR.sup.3 X wherein Y and Y.sup.1 are hydrogen or a methyl radical; R.sup.2 and R.sup.3 are alkyl groups containing from 1 to about 20 carbon atoms; and X is a hydroxyl, carboxyl, amine, epoxide, amide, COOR and Si(OR.sup.1).sub.3 groups wherein R and R.sup.1 are alkyl groups containing from 1 to about 20 carbon atoms.
- 3. The process of claim 1 wherein said further-curable organopolysiloxane is the partial hydrolysis and condensation product of at least one compound represented by the general formula R.sub.n.sup.4 SiZ.sub.(4-n) wherein R.sup.4 represents a monovalent hydrocarbon radical, Z represents a hydrolyzable group, and n may vary between 0 and 2.
- 4. The process of claim 3 wherein Z represents an --OR.sup.5 group wherein R.sup.5 is a monovalent hydrocarbon radical and wherein n is 0 or 1.
- 5. The process of claim 3 wherein Z represents an --OCOR.sup.6 group wherein R.sup.6 is a monovalent hydrocarbon radical.
- 6. The process of claim 1 wherein said primer composition contains at least one ultraviolet light absorbing compound.
Parent Case Info
This is a division of application Ser. No. 956,809, filed Nov. 1, 1978 now U.S. Pat. No. 4,243,720.
US Referenced Citations (19)
Divisions (1)
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Number |
Date |
Country |
Parent |
956809 |
Nov 1978 |
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