FAST DRY POLYESTER LATEX FOR COATINGS
A fast drying latex composition comprising a hydroxyl functional polyester modified with a polyfunctional isocyanate is provided. The modification increases polymer molecular weight by chain extension. Such a fast drying latex composition can be utilized in a coating composition with or without a pigment. The fast drying latex composition does not adversely affect the stability of the polyester latex, and in some situations, may stabilize inherently unstable polyester latexes.
1 . A fast drying latex composition comprising an aqueous emulsion comprising a hydroxyl functional polyester modified with a polyfunctional isocyanate.
2 . A paint or clear coat composition comprising the fast drying latex composition of claim 1 and a pigment.
3 . The fast drying latex composition according to claim 1 , wherein the hydroxyl functional polyester is derived from a natural oil or natural fatty acid.
4 . The fast drying latex composition according to claim 3 , wherein the natural oil is selected from the group consisting of soybean oil, palm oil, sunflower seed oil, linseed oil, tung oil, cottonseed oil, and oiticica.
5 . The fast drying latex composition according to claim 1 , wherein said composition further includes an anionic surfactant and/or a non-ionic surfactant and/or amphoteric surfactant and/or cationic surfactant.
6 . The fast drying latex composition according to claim 1 , wherein the polyfunctional isocyanate is an aliphatic or aromatic polyfunctional isocyanate.
7 . The fast drying latex composition according to claim 1 , wherein the acid value of the polyester is in a range of about 0 to about 150 mg KOH per gram,
8 . The fast drying latex composition according to claim 1 , wherein the hydroxyl value of the polyester is in a range of about 15 to about 180 mg KOH per gram.
9 . The fast drying latex composition according to claim 1 , wherein the fast drying latex composition has a NCO/OH index in a range of about 0.1:1.0 to about 1.0:1.0.
10 . The fast drying latex composition according to claim 1 , wherein the fast drying latex composition has a solids content in a range of about 30 to about 70 percent.
11 . The fast drying latex composition according to claim 1 , wherein the polyester is further modified with acrylic or styrene acrylic monomer or oligomer.
12 . A substrate coated with a coating comprising the fast drying latex composition of claim 1 .
13 . A fast drying latex composition in emulsion form comprising:
a) a hydroxyl functional polyester comprising:
1) 18 to 45 percent by weight of a difunctional carboxylic acid and/or anhydride thereof;
2) 5 to 15 percent by weight of a diol;
3) 5 to 50 percent by weight of a an alcohol having more than two hydroxyl groups;
4) 0 to 35 percent by weight of a monofunctional acid; and
5) 20 to 80 percent by weight of a natural oil and/or natural or synthetic fatty acid; and
b) a polyfunctional isocyanate wherein the polyfunctional isocyanate increases polymer molecular weight by chain extension.
14 . A paint composition or clear coat comprising the fast drying latex composition of claim 13 and a pigment.
15 . The fast drying latex composition according to claim 13 , wherein said composition further includes an anionic surfactant, a non-ionic, a cationic surfactant or an amphoteric surfactant or mixture or blend thereof.
16 . The fast drying latex composition according to claim 13 , wherein the polyfunctional isocyanate is an aliphatic or aromatic polyfunctional isocyanate.
17 . The fast drying latex composition according to claim 13 , wherein the acid value of the polyester is in a range from about 0 to about 150 mg KOH per gram.
18 . The fast drying latex composition according to claim 13 , wherein the hydroxyl value of the polyester is in a range of about 15 to about 800 mg KOH per gram.
19 . The fast drying latex composition according to claim 13 , wherein the fast drying latex composition has a NCO/OH index in a range of about 0.1:1.0 to about 1.0:1.0.
20 . The fast drying latex composition according to claim 13 , wherein the fast drying latex composition has a solids content in a range of about 30 to about 70 percent.
21 . The fast drying latex composition according to claim 13 , wherein the polyester is further modified with acrylic or styrene acrylic monomer or oligomer.
22 . A substrate coated with a coating comprising the fast drying latex composition of claim 13 .