Chip-resistant pigmented polyurethane protective coating

Claim 2

Method of applying to a substrate a chip-resistant pigmented polyurethane protective coating particularly suited for matching existing pigmented protected surfaces on said substrate wherein said existing protected surface is provided by an acrylic lacquer, acrylic enamel or nitrocellulose lacquer containing the same pigmentation, said method comprising: (1) blending (a) liquid curable primary amine-free non-coloring polyurethane coating composition curable to form a polyurethane having an elongation at break of at least 75% and being formed of a catalyzed mixture of polyester polyol having more than one terminal hydroxyl group and an equivalent weight between 250 and 1500, sufficient polyisocyanate compound characterized by having at least two terminal isocyanate groups each attached to a non-benzenoid carbon to provide an NCO:OH ratio of about 2:1 to about 0.8:1, and compatible organic solvent to make a solids content about 20% to 70% by weight and a vicosity of about 20 to 300 cps as determined using a Brookfield RVF viscometer at 25° C. using a No. 1 spindle at 20 rpm; and (b) liquid pigmented protective coating composition selected from the group consisting of acrylic lacquer, acrylic enamel and nitrocellulose lacquer reduced with compatible solvent for use in a wet volume ratio of pigmented protective coating composition to polyurethane coating composition of about 2:1 to 1:20; (2) applying at least one coating of the resultant blend to said surface to provide a uniform dry coating thickness of from about 1 to 20 mils; and (3) permitting said coating to dry.

Claim 3

The method of claim 1 wherein there is initially coated on the surface of said substrate at least one unpigmented coating of said polyurethane coating composition.

Claim 4

The method of claim 1 wherein said substrate is coated initially with a primer.

Claim 5

Method of applying to a substrate a chip-resistant pigmented polyurethane protective coating particularly suited for matching existing pigmented surfaces on said substrate wherein said existing protected surface is provided by an acrylic lacquer, acrylic enamel or nitrocellulose lacquer containing the same pigmentation, said method comprising: (1) applying to said substrate at least three uniform coats comprising an unpigmented liquid curable primary amine-free nondiscoloring polyurethane coating composition curable to form a polyurethane having an elongation at break of at least 75% and being formed of a catalyzed mixture of polyester polyol having more than one terminal hydroxyl group and an equivalent weight between 250 and 1500, sufficient polyisocyanate compound characterized by having at least two terminal isocyanate groups each attached to a non-benzenoid carbon to provide an NCO:OH ratio of about 2:1 to about 0.8:1, and compatible organic solvent to make a solids content about 20% to 70% by weight and a viscosity of about 20 to 300 cps as determined using a Brookfield RVF viscometer at 25° C. using a No. 1 spindle at 20 rpm; (2) permitting said organic solvent to flash evaporate to provide a coating having a tacky surface condition between coats; (3) applying sufficient uniform coats of a blend of said unpigmented polyurethane coating composition and a liquid pigmented protective coating composition selected from the group consisting of acrylic lacquer, acrylic enamel and nitrocellulose lacquer reduced with compatible solvent for use in a wet volume ratio of pigmented protective coating composition to polyurethane coating composition of about 2:1 to 1:20 to provide a uniform dry coating thickness of from about 1 to 20 mils; and (4) permitting said coats to dry.

Claim 6

Method of applying to a substrate a chip-resistant pigmented polyurethane protective coating particularly suited for matching existing pigmented surfaces on said substrate wherein said existing protected surface is provided by an acrylic lacquer, acrylic enamel or nitrocellulose lacquer containing the same pigmentation, said method comprising: (1) applying to said substrate at least three uniform coats comprising an unpigmented liquid curable primary amine-free nondiscoloring polyurethane coating composition curable to form a polyurethane having an elongation at break of at least 75% and being formed of a catalyzed mixture of polyester polyol having more than one terminal hydroxyl group and an equivalent weight between 250 and 1500, sufficient polyisocyanate compound characterized by having at least two terminal isocyanate groups each attached to a non-benzenoid carbon to provide an NCO:OH ratio of about 2:1 to about 0.8:1, and compatible organic solvent to make a solids content about 20% to 70% by weight and a viscosity of about 20 to 300 cps as determined using a Brookfield RVF viscometer at 25° C. using a No. 1 spindle at 20 rpm; (2) permitting said organic solvent to flash evaporate to provide a coating having a tacky surface condition between coats; (3) applying sufficient uniform coats of a blend of said unpigmented polyurethane coating composition and a liquid pigmented protective coating composition selected from the group consisting of acrylic lacquer, acrylic enamel and nitrocellulose lacquer reduced with compatible solvent for use in a wet volume ratio of pigmented protective coating composition to polyurethane coating composition of about 2:1 to 1:20 to provide a uniform dry coating thickness of from about 1 to 20 mils; and (4) permitting said coats to dry.