Water reducible acrylic modified polyester compositions
AssigneeThe Sherwin-Williams Company
InventorJose J. Chettiath
Life of this patent
Estimating the term…
Abstract
This invention relates to a novel air drying acrylic modified polyester composition and to the method of preparing said compositions which are particularly useful in forming coatings on various substrates and particularly on metal surfaces. The acrylic modified polyesters are water reducible and are obtained from the copolymerization of a polyester prepolymer and a combination of ethylenically unsaturated vinyl monomers comprising at least one acrylic monomer. The prepolymers are derived from the reaction of a styrene-allylic alcohol polymer with a mixture of unsaturated monocarboxylic acids comprising at least one unsaturated fatty acid and at least one monoanhydride having at least one free carboxylic acid group.
Claims20
A water reducible air drying acrylic modified polyester having an acid value greater than about 25 obtained by the copolymerization of :
- (a) from about 50 to 70 parts by weight of a polyester prepolymer, and
- (b) from about 30 to 50 parts by weight of a combination of ethylenically unsaturated vinyl monomers comprising at least one acrylic monomer;
- said polyester prepolymer obtained from the reaction of (i) a styrene-allylic alcohol polymer with (ii) at least one unsaturated fatty acid, and (iii) at least one unsaturated monocarboxylic acid having the formula:
- ##STR8## wherein R.sub. 1 is either hydrogen or an alkyl group of 1 to 3 carbon atoms and R.sub. 2 is an aliphatic group of 1 to 4 carbon atoms or an aryl group to obain hydroxy-functional polymers and subsequently reacting said hydroxy-functional polymer with (iv) at least one monoanhydride having at least one free carboxylic acid group.
A method of preparing a water reducible air drying arcylic modified polyester having an acid value greater than about 25 which comprises copolymerizing:
- (a) from about 50 to 70 parts by weight of a polyester prepolymer, and
- (b) from about 30 to 50 parts by weight of a combination of ethylenically unsaturated vinyl monomers comprising at least one acrylic monomer;
- said polyester prepolymer obtained from the reaction of (i) a styrene-allylic alcohol polymer with (ii) at least one unsaturated fatty acid, and (iii) at least one unsaturated monocarboxylic acid having the formula:
- ##STR9## wherein R.sub.1 is either hydrogen or an alkyl group of 1 to 3 carbon atoms and R.sub.2 is an aliphatic group of 1 to 4 carbon atoms or an aryl group to obtain hydroxy-functional polymers and subsequently reacting said hydroxy-functional polymers with at least one monoanhydride having at least one free carboxylic acid group.
A water reducible air drying coating composition comprising 25 to 60 parts by weight of an acrylic modified polyester having an acid value greater than about 30, from 0 to 60 parts by weight of pigment, from 0 to 30 parts by weight of a cosolvent, and up to about 95 parts by weight of water;
- said acrylic modified polyester obtained by the copolymerization of:
- (a) from about 50 to 70 parts by weight of a polyester prepolymer, and
- (b) from about 30 to 50 parts by weight of a combination of ethylenically unsaturated vinyl monomers comprising at least one acrylic monomer;
- said polyester prepolymer obtained from the reaction of (i) a styrene-allylic alcohol polymer with (ii) at least one unsaturated fatty acid, and (iii) at least one unsaturated monocarboxylic acid having the formula:
- ##STR10## wherein R.sub.1 is either hydrogen or an alkyl group of 1 to 3 carbon atoms and R.sub.2 is an alkyl group of 1 to 4 carbon atoms or an aryl group to obtain a hydroxy-functional polymer and subsequently reacting said hydroxy-functional polymer with (iv) at least one monoanhydride having at least one free carboxylic acid group.
Dependencies are inferred from the claim text.