Coating composition of an acrylic polymer, a dispersed acrylic polymer and an alkylated melamine crosslinking agent

Claim 2

A coating composition comprising about 20-85% by weight of film forming binder and 15-80% by weight of an organic liquid carrier: (a) an acrylic polymer I consisting essentially of polymerized monomers of alkyl methacrylate, alkyl acrylate and hydroxy alkyl acrylate or methacrylate and having a weight average molecular weight of about 3,000 to 20,000; (b) a self stabilized dispersed resin formed by polymerizing in solution the following constituents: (1) an acrylic polymer II consisting essentially of polymerized monomers comprising alkyl methacrylate, alkyl acrylate, hydroxy alkyl acrylate or methacrylate, an ethylenically unsaturated carboxylic acid and having a weight average molecular weight of 3,000 to 20,000; (2) monomers comprising alkyl methacrylate, alkyl acrylate and hydroxy alkyl acrylate or methacrylate; wherein either acrylic polymer II contains glycidyl methacrylate or acrylate monomers post reacted with the carboxylic acid or the monomers contain glycidyl methacrylate or acrylate; (c) an alkylated melamine formaldehyde crosslinking agent; wherein the molecular weight of each of the polymers is determined by gel permeation chromatography using polymethyl methacrylate as the standard.

Claim 3

The coating composition of claim 1 comprising about 50-80% by weight of film forming binder and 20-50% by weight of organic solvent for the binder.

Claim 4

The coating composition of claim 2 wherein the binder comprises: (a) 5-75% by weight, based on the weight of the binder, of acrylic polymer I, (b) 5-45% by weight, based on the weight of the binder, of self stabilized dipsersion resin and (c) 20-50% by weight, based on the weight of the binder, of an alkylated melamine formaldehyde crosslinking agent.

Claim 5

The coating composition of claim 3 in which acrylic polymer I consists essentially of polymerized monomers of styrene, alkyl methacrylate, alkyl acrylate, hydroxy alkyl acrylate or methacrylate.

Claim 6

The coating composition of claim 4 in which acrylic polymer I consists essentially of polymerized monomers of about 5-30% by weight styrene, 10-40% by weight of butyl methacrylate, 10-40% by weight of butyl acrylate and 15-50% by weight of hydroxy ethyl acrylate or hydroxy propyl acrylate and has a weight average molecular weight of about 5,000-15,000.

Claim 7

The coating composition of claim 4 in which the acrylic polymer I contains additionally about 0.1-5% by weight of acrylic acid or methacrylic acid.

Claim 8

The coating composition of claim 3 in which acrylic polymer II consists essentially of polymerized monomers of styrene, alkyl methacrylate, alkyl acrylate, hydroxy alkyl acrylate or methacrylate and acrylic acid or methacrylic acid.

Claim 9

The coating composition of claim 7 in which acrylic polymer II was post reacted with glycidyl methacrylate.

Claim 10

The coating composition of claim 7 in which the acrylic polymer II consists essentially of 5-25% by weight styrene, 20-40% by weight butyl methacrylate, 20-40% by weight butyl acrylate, 5-15% by weight hydroxy ethyl acrylate, 1-5% by weight acrylic acid, 10-20% by weight ethyl methacrylate and having a weight average molecular weight of about 7,000-15,000.

Claim 11

The coating composition of claim 8 in which the acrylic polymer II consists essentially of 5-25% by weight styrene, 25-35% by weight butyl methacrylate, 20-40% butyl acrylate, 5-15% by weight hydroxy ethyl acrylate, 1-5% by weight acrylic acid, 10-20% by weight ethyl methacrylate and 1-5% by weight glycidyl methacrylate post reacted with acrylic acid and having a weight average molecular weight of 7,000 to 15,000.

Claim 12

The coating composition of claim 3 in which the monomers of the self stabilized dispersion resin comprise styrene, methyl methacrylate, hydroxy ethyl acrylate, methacrylic acid, methyl acrylate and glycidyl methacrylate.

Claim 13

The coating composition of claim 3 containing in addition about 0.1-2% by weight, based on the weight of the coating composition, of an acid catalyst.

Claim 14

The coating composition of claim 3 in which the alkylated melamine formaldehyde crosslinking agent is about 50% methylated and 50% butylated.

Claim 15

The coating composition of claim 3 containing in addition about 0.1-5% by weight, based on the weight of the binder of an ultraviolet light stabilizer.

Claim 16

The coating composition of claim 1 which comprises 50-80% by weight of film forming binder and 20-50% by weight of an organic solvent for the binder; wherein the binder consists essentially of about (a) 5-75% by weight of a solution acrylic Polymer I consisting of essentially of about 5-30% by weight styrene, 10-40% by weight butyl methacrylate, 10-40% by weight butyl acrylate, 15-50% by weight hydroxy ethyl acrylate or hydroxy propyl acrylate and having a weight average molecular weight of about 5,000-15,000; (b) 5-45% by weight of a self stabilized dispersed resin formed by polymerizing in solution the following constituents: (1) an acrylic solution Polymer II consisting essentially of 5-25% by weight styrene, 20-40% by weight butyl acrylate, 20-40% by weight butyl methacrylate, 5-15% by weight hydroxy ethyl acrylate, 1-5% by weight acrylic acid 10-20% by weight ethyl methacrylate and having a weight average molecular weight of about 7,000-15,000; (2) monomers of styrene, methyl methacrylate hydroxy ethyl acrylate, methacrylic acid, methyl acrylate and glycidyl methacrylate; (3) an acrylic solution polymer II wherein the carboxyl groups of the acrylic acid monomers are post reacted with glycidyl methacrylate; (c) 25-40% by weight of a fully methylated and butylated melamine formaldehyde crosslinking agent.

Claim 17

A substrate coated with a cured layer of the composition of claim 1.

Claim 18

A substrate coated with a layer of a pigmented paint composition and having a layer in adherence to thereto of the composition of claim 1.