Polycarbonate surfaces having tenaciously adhered organopolysiloxane coatings thereon and process for making

Claim 2

The process as defined in claim 2 wherein said gamma-aminopropyltrialkoxysilane is gamma-aminopropyltriethoxysilane.

Claim 3

The process as defined in claim 3 wherein the alkoxy groups of said methyltrialkoxysilane and said phenyltrialkoxysilane are ethoxy groups.

Claim 4

The process as defined in claim 2 wherein said solvent-soluble, further-curable organopolysiloxane is a hydrolysis and condensation product of methyltriethoxysilane.

Claim 5

The process as defined in claim 2 wherein said solvent-soluble, further-curable organopolysiloxane is a hydrolysis and condensation product of a mixture of methyltriethoxysilane and phenyltriethoxysilane.

Claim 6

The process of claim 2 wherein said polycarbonate is characterized by a reoccurrence of the following structural unit:

Claim 7

The article produced by the process of claim 1.

Claim 8

A process for producing an article having a solid polycarbonate surface which is coated to provide a uniformly and tenaciously adhered, hard, mar-resistant, heat-resistant and acetone-resistant coated surface, the process comprising the steps of: A. priming said surface with gamma-aminopropyltriethoxysilane, B. applying a solution of a solvent-soluble, further-curable organopolysiloxane in an organic solvent on the primed polycarbonate surface, said further-curable, solvent-soluble organopolysiloxane being a precured hydrolysis and condensation product of methyltrialkoxysilane in which the alkoxy group contains between one and five carbon atoms and being prepared by heating said silane and water in the presence of a hydrolysis catalyst for about 1 to 10 hours at a temPerature between about 40* C. and reflux to produce a siloxane partial condensation product, concentrating said partial condensation product by heating to a temperature within the range of about 65* to 300* C. to remove alkanol byproduct and some water, precuring the concentrated product by heating at a temperature of between about 70* to 300* C. and below the gel point thereof to provide said solvent-soluble, further, curable organopolysiloxane, and C. evaporating the solvent for said organopolysiloxane and finally curing said organopolysiloxane to provide a thermoset coating on said polycarbonate surface.

Claim 9

The process as defined in claim 9 wherein step A comprises the step of applying a solution of gamma-aminopropyltriethoxysilane onto said polycarbonate surface, and allowing the solvent of said solution to evaporate.

Claim 10

The process as defined in claim 10 wherein said methyltrialkoxysilane is methyltriethoxysilane.

Claim 11

A process for producing an article having a polycarbonate surface which is coated to provide a hard, mar-resistant, tenaciously and uniformly adhered, heat-resistant and acetone-resistant coated surface, said process comprising the steps of: A. priming said polycarbonate surface with gamma-aminopropyltriethoxysilane, B. applying a solution of a solvent-soluble, further-curable organopolysiloxane in an organic solvent on the primed polycarbonate surface, said further-curable organopolysiloxane being a precured hydrolysis and condensation product of a mixture of methyltrialkoxysilane and phenyltrialkoxysilane in which the alkoxy groups contain between one and five carbon atoms, said organopolysiloxane being prepared by heating said silane and water in the presence of a hydrolysis catalyst for about 1 to about 10 hours at a temperature between ambient and reflux to produce a siloxane partial condensation product, concentrating the partial condensation product by heating to remove about 50 to 90 mole percent alkanol byproduct and some water, precuring the concentrated product at a temperature between about 70* and 250* C. and below the gel point thereof to provide said solvent-soluble, further-curable organopolysiloxane, and C. evaporating the solvent for said organopolysiloxane and finally curing said organopolysiloxane to provide a thermoset coating on said polycarbonate surface.

Claim 12

The process as defined in claim 12 wherein step A comprises forming a film of gamma-aminopropyltriethoxysilane on said polycarbonate surface.

Claim 13

The process as defined in claim 13 wherein said solvent-soluble, further-curable organopolysiloxane is a hydrolysis and condensation product of a mixture of methyltriethoxysilane and phenyltriethoxysilane.