Aqueous epoxy-urethane dispersions
AssigneeCelanese Corporation
InventorsHubert H. Fowler, Joe M. Hunter
Life of this patent
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Abstract
Stable aqueous epoxy resin dispersions are made from a self-emulsifying epoxy resin film forming component which is the reaction product of a diglycidyl ether of a dihydric phenol, a dihydric phenol, a diglycidyl ether of a polyoxyalkylene glycol and a diisocyanate. The dispersion also contains a water-immiscible aliphatic monoepoxide and a water-miscible organic solvent. The dispersions will cure with epoxy resin curing agents to form coatings for industrial uses.
Claims12
An epoxy dispersion composition comprising (1) an aqueous medium;
- (2) between about 50-70 weight percent of self-emulsifying epoxy resin which is the addition product of reactants comprising (a) 40-90 parts by weight of a diglycidyl ether of a dihydric phenol, (b) 5-35 parts by weight of a dihydric phenol, (c) 2-15 parts by weight of a diglycidyl ether of polyoxyalkylene glycol and (d) 2-6 weight percent based on the weight of (a), (b) and (c) of an organic diisocyanate which is aliphatic, cycloaliphatic or aromatic, and which contains no groups reactive with epoxy groups or hydroxyl groups other than isocyanate groups, wherein the molecular weight of the epoxy resin is in the range from about 800-20,000;
- (3) 1-25 weight percent, based on resin solids weight, of water-immiscible C.sub.8 -C.sub.20 aliphatic monoepoxide reactive diluent;
- and (4) 5-20 weight percent, based on resin solids weight, of water-miscible solvent selected from C.sub.2 -C.sub.10 glycols and glycol ethers.
A water-borne paint composition comprising (A) an epoxy dispersion of (1) an aqueous medium;
- (2) between about 50-70 weight percent of self-emulsifying epoxy resin which is the addition product of reactants comprising (a) 40-90 parts by weight of diglycidyl ether of dihydric phenol, (b) 5-35 parts by weight of dihydric phenol, (c) 2-15 parts by weight of diglycidyl ether of polyoxyalkylene glycol and (d) 2-6 weight percent based on the weight of (a), (b) and (c) of an organic diisocyanate which is aliphatic, cycloaliphatic or aromatic, and which contains no groups reactive with epoxy groups or hydroxyl groups other than isocyanate groups, wherein the average molecular weight of the epoxy resin is in the range between about 800-20,000;
- (3) 1-25 weight percent, based on resin solids weight, of water immiscible C.sub.8 -C.sub.20 aliphatic monoepoxide reactive diluent;
- and (4) 5-20 weight percent, based on resin solids weight, of water-miscible solvent selected from C.sub.2 -C.sub.10 glycols and glycol ethers;
- in admixture with (B) polyamine curing agent, wherein the ratio of active amino hydrogens to epoxy groups is in the range between about 0.5-2:1.
Dependencies are inferred from the claim text.