Pigment dispersants for coating compositions

A dispersant compatible with a variety of resin-containing coating compositions and especially adapted for dispersing pigments therein, said dispersant being the polymerization product of a mixture of monomers consisting essentially of:

• (i) from about 20 percent to about 85 percent of an alkyl methacrylate having from 3 to 8 carbon atoms in the alkyl group;
• (ii) from about 5 percent to about 60 percent of a hardening monomer selected from the group consisting of a styrene, methyl methacrylate, ethyl methacrylate and mixtures thereof;
• (iii) from about 1 percent to about 25 percent of a monomer having a double bond alpha-beta to a carbonyl group, said monomer being an alkyl acrylate;
• (iv) from about 1 percent to about 25 percent of a monomer having a double bond alpha-beta to a carbonyl group and at least one hydroxyl group selected from the group consisting of a monohydroxy alkyl acrylate, monohydroxy alkyl methacrylate, monohydroxy alkyl crotonate, monohydroxy alkyl fumarate, dihydroxy alkyl fumarate, monohydroxy alkyl itaconate, dihydroxy alkyl itaconate, monohydroxy alkyl maleate, dihydroxy alkyl maleate and mixtures thereof;
• and
• (v) from about 0.1 percent to about 15 percent of a compound providing an amine functional moiety, said compound being an acrylic or methacrylic compound containing amino groups;
• wherein the said polymerization product is further reacted with water to provide carboxyl functionality from units provided by the alkyl acrylate monomer and wherein said dispersant has a weight average molecular weight, determined by gel permeation chromatography, using a polystyrene standard, of from about 1,000 to about 10,000.

A dispersant compatible with a variety of resin-containing coating compositions and especially adapted for dispersing pigments therein, said dispersant being the polymerization product of a mixture of monomers consisting essentially of:

• (i) from about 20 percent to about 85 percent of an alkyl methacrylate having from 3 to 8 carbon atoms in the alkyl group;
• (ii) from about 5 percent to about 60 percent of a hardening monomer selected from the group consisting of a styrene, methyl methacrylate, ethyl methacrylate and mixtures thereof;
• (iii) from about 1 percent to about 25 percent of a monomer having a double bond alpha-beta to a carbonyl group, said monomer being an unsaturated carboxylic anhydride;
• (iv) from about 1 percent to about 25 percent of a monomer having a double bond alpha-beta to a carbonyl group and at least one hydroxyl group selected from the group consisting of a monohydroxy alkyl acrylate, monohydroxy alkyl methacrylate, monohydroxy alkyl crotonate, monohydroxy alkyl fumarate, dihydroxy alkyl fumarate, monohydroxy alkyl itaconate, dihydroxy alkyl itaconate, monohydroxy alkyl maleate, dihydroxy alkyl maleate and mixtures thereof;
• and
• (v) from about 0.1 percent to about 15 percent of a compound providing an amine functional moiety, said compound being an acrylic or methacrylic compound containing amino groups;
• wherein the said polymerization product is further reacted with water, alcohol or amine to provide carboxyl functionality from units provided by the unsaturated carboxylic anhydride monomer and wherein said dispersant has a weight average molecular weight, determined by gel permeation chromatography, using a polystyrene standard of from about 1,000 to about 10,000.

A dispersant compatible with a variety of resin-containing coating compositions and especially adapted for dispersing pigments therein, said dispersant being the polymerization product of a mixture of monomers consisting essentially of:

• (i) from about 20 percent to about 85 percent of an alkyl methacrylate having from 3 to 8 carbon atoms in the alkyl group;
• (ii) from about 5 percent to about 60 percent of a hardening monomer selected from the group consisting of a styrene, methyl methacrylate, ethyl methacrylate and mixtures thereof;
• (iii) from about 1 percent to about 25 percent of a monomer having a double bond alpha-beta to a carbonyl group, said monomer being a hydroxyl-containing monomer;
• (iv) from about 1 percent to about 25 percent of a monomer having a double bond alpha-beta to a carbonyl group and at least one hydroxyl group selected from the group consisting of a monohydroxy alkyl acrylate, monohydroxy alkyl methacrylate, monohydroxy alkyl crotonate, monohydroxy alkyl fumarate, dihydroxy alkyl fumarate, monohydroxy alkyl itaconate, dihydroxy alkyl itaconate, monohydroxy alkyl maleate, dihydroxy alkyl maleate and mixtures thereof;
• and
• (v) from about 0.1 percent to about 15 percent of a compound providing an amine functional moiety, said compound being an acrylic or methacrylic compound containing amino groups;
• wherein the said polymerization product is further reacted with an anhydride to provide carboxyl functionality from units provided by the hydroxy-containing monomer and wherein said dispersant has a weight average molecular weight, determined by gel permeation chromatography, using a polystyrene standard, of from about 1,000 to about 10,000.

A dispersant compatible with a variety of resin-containing coating compositions and especially adapted for dispersing pigments therein, said dispersant being the polymerization product of a mixture of monomers consisting essentially of:

• (i) from about 20 percent to about 85 percent of an alkyl methacrylate having from 3 to 8 carbon atoms in the alkyl group;
• (ii) from about 5 percent to about 60 percent of a hardening monomer selected from the group consisting of a styrene, methyl methacrylate, ethyl methacrylate and mixtures thereof;
• (iii) from about 1 percent to about 25 percent of a monomer having a double bond alpha-beta to a carbonyl group, said monomer being an amine-containing monomer;
• (iv) from about 1 percent to about 25 percent of a monomer having a double bond alpha-beta to a carbonyl group and at least one hydroxyl group selected from the group consisting of a monohydroxy alkyl acrylate, monohydroxy alkyl methacrylate, monohydroxy alkyl crotonate, monohydroxy alkyl fumarate, dihydroxy alkyl fumarate, monohydroxy alkyl itaconate, dihydroxy alkyl itaconate, monohydroxy alkyl maleate, dihydroxy alkyl maleate and mixtures thereof;
• and
• (v) from about 0.1 percent to about 15 percent of a compound providing an amine functional moiety, said compound having an acrylic or methacrylic compound containing amino groups;
• wherein the said polymerization product is further reacted with an anhydride to provide carboxyl functionality from units provided by the amine-containing monomer and wherein said dispersant has a weight average molecular weight, determined by gel permeation chromatography, using a polystyrene standard, of from about 1,000 to about 10,000.