US 6,472,493 B1 · Clear coating composition having improved early hardness and water resistance

Abstract

A fast hardening clear coating composition for repairing a clearcoat/colorcoat finish of a vehicle, which composition is capable of being wet sanded, buffed or polished to a high gloss finish on the same day of application, comprising a film forming binder and an organic liquid carrier, where the binder contains a hydroxyl component comprising a hydroxyl-containing acrylic polymer and a hydroxyl-terminated polyester oligomer, and an organic polyisocyanate crosslinking component, at least portion of which comprises a trimer of isophorone diisocyanate, where the composition further contains, as a combined curing catalyst, at least one dialkyl tin aliphatic carboxylate, at least one tertiary aliphatic mono or diamine, and at least one aliphatic carboxylic acid, in an effective amount such that the clear coating composition on curing at ambient temperatures is in a water spot free and sufficiently hard state for sanding or buffing within about 4 hours after application or on cool down when baked under normal conditions.

Claims12

Dependent claims

A clear coating composition, containing a film forming binder and a volatile organic liquid carrier for the binder, wherein the binder contains

(A) a hydroxyl component comprising at least one hydroxyl-containing acrylic polymer and at least one hydroxyl-terminated polyester oligomer;
and
(B) an organic polyisocyanate component, at least a portion of which comprises a timer of isophorone diisocyanate;
wherein the ratio of equivalents of isocyanate per equivalent of hydroxy groups in the binder is in the range of about 0.5/1 to 3.0/1;
wherein tie composition further contains
(C) a catalyst system for the binder comprising about
(i) 0.005-0.2% by weight, based on the weight of the binder, of at least one organotin compound,
(ii) 0.01-1% by weight, based on the weight of the binder, of at least one tertiary amine, and
(iii) 0.005-1%, based on the weight of the binder, of at least one organic carboxylic acid;
wherein the coating composition cures at ambient temperatures to a water spot free and sand and buff state within 4 hours after application.

7 more elements

A clear coating composition containing about 25-90% by weight of a film forming binder and about 10-75% by weight of a volatile organic liquid carrier for the binder and a VOC content of less than about 4.4 lbs/gal, wherein the binder contains

(A) a hydroxyl component comprising about
(i) 50-99% by weight, based on the total weight of the hydroxyl component, of a hydroxyl-containing acrylic polymer formed of polymerized monomers of styrene;
a methacrylate selected from the group consisting of methyl methacrylate, isobornyl methacrylate, cyclohexyl methacrylate, and any mixtures thereof;
a second methacrylate monomer selected from the group consisting of n-butyl methacrylate, isobutyl methacrylate and ethyl hexyl methacrylate, and any mixtures thereof;
and a hydroxy alkyl methacrylate or acrylate, each having 1-8 carbon atoms in the alkyl group;
wherein the acrylic polymer has a weight average molecular weight of about 2,000-13,000 and a glass transition temperature of at least 25° C.;
(ii) 1-50% by weight, based on the total weight of the hydroxyl component, of a hydroxyl-terminated polyester oligomer formed of either oligomerized monomers of caprolactone and a cycloaliphatic polyol;
and of oligomerized monomers and a cycloaliphatic anhydride, a linear or branched polyol, and an alkylene oxide;
wherein the polyester oligomer has a weight average molecular weight not exceeding about 3,000 and a polydispersity less than about 1.7;
(B) an organic polyisocyanate component comprising about
(i) 3-50% by weight, based on the total weight of the polyisocyanate component, of a trimer of isophorone diisocyanate;
(ii) 50-97% by weight, based on the total weight of the polyisocyanate component, of a trimer of hexamethylene diisocyanate;
wherein the ratio of equivalents of isocyanate groups per equivalent of hydroxyl groups in the binder is in the range from about 0.5/1 to 3/1;
wherein the composition further contains:
(C) a catalyst system for the binder comprising about
(i) 0.005-0.2% by weight, based on the weight of the binder, of an organotin compound selected from dialkyl tin dicarboxylate,
(ii) 0.01-1% by weight, based on the weight of the binder, of a tertiary amine selected from the group consisting of trialkyl amines, trialkylene diamines, and any mixtures thereof;
and
(iii) 0.005-1%, based on the weight of the binder, of an organic acid selected from an aliphatic carboxylic acid.

16 more elements

Dependencies are inferred from the claim text.

Clear coating composition having improved early hardness and water resistance

Life of this patent

Clear coating composition having improved early hardness and water resistance

Life of this patent

Abstract

Claims12