Curable composition

1. An aqueous composition comprising:

a) polymer particles of at least one polycarboxy emulsion copolymer comprising as copolymerized units, based on the weight of the emulsion copolymer solids:

i) from 5-40% by weight of a carboxy acid monomer, and

ii) from 0.1 to 5 weight percent of a multi-ethylenically unsaturated monomer; and,

b) at least one binder selected from the group consisting of a polysaccharide which is a water-insoluble starch with a weight average molecular weight of between 10,000 and 10,000,000, the binder being present in a weight percent on total composition binder solids of from 20-95%,

wherein the binder is pre-cooked with a polybasic carboxylic acid, anhydride or salt thereof, having a weight average molecular weight of 1000 or less.

2. The aqueous composition of claim 1 wherein the carboxy acid monomer is acrylic acid.

3. The aqueous composition of claim 2 wherein the amount of acrylic acid, as copolymerized units, is from 10 to 20% by weight, based on the weight of polycarboxy emulsion copolymer solids.

4. The aqueous composition of claim 1 wherein the multi-ethylenically unsaturated monomer is allyl methacrylate.

5. The aqueous composition of claim 1 wherein the binder comprises a water-soluble starch with a weight average molecular weight of less than 10,000.

6. The aqueous composition of claim 1 wherein the binder comprises defatted soy flour.

7. The aqueous composition of claim 1 wherein the polycarboxy emulsion copolymer comprises copolymerized acrylonitrile.

8. The aqueous composition of claim 1 further comprising a phosphorus-containing compound.