Aqueous two-part isocyanate-free curable, polyurethane resin systems
AssigneeGuertin Bros. Coatings and Sealants Ltd.
InventorZhiqiang Song
Life of this patent
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Abstract
Aqueous-borne coating compositions containing: (A) an acetoacetylated polymer; and (B) a polyacrylate having at least two (meth)acrylate end groups, have long pot lives and may be cured by the evaporation of water in the presence of a basic catalyst. Acrylic copolymers having pendent urethane side groups which are terminated with (meth)acrylate groups are water-dispersible and may be cured with polyfunctional crosslinking agents or by free radical initiators to afford coatings having excellent properties. Incorporation of a crosslinking component containing epoxy groups improves the coating properties.
Claims30
An ambient-temperature-curable aqueous polymer system, comprising:
- (A) an acetoacetylated polymer;
- and
- (B) a polyacrylate containing at least two (meth)acrylate end groups,
- in the form of an aqueous solution, suspension, or emulsion, wherein said acetoacetylated polymer is a water-dispersible acetoacetylated acrylic resin obtained by solution copolymerization of 10 to 60 wt. % of a (meth)acrylic monomer (M1) having the formula
- CH.sub.2 .dbd.C(R1)--CO--O--R2--O--CO--CH.sub.2 --CO--CH.sub.3(M 1)
- wherein R1 is --H or --CH.sub.3 and R2 is a linear or branched saturated C.sub.1-4 alkylene group, 1 to 15 wt. % of a carboxyl vinyl monomer (M2), and 25 to 89 wt. % of a copolymerizable vinyl monomer (M3) selected from the group consisting of C.sub.1-4 -alkyl (meth)acrylate and styrene.
An ambient-temperature curable composition, comprising:
- (A) a compound containing at least two acetoacetate methylene groups;
- (B) a compound containing at least two acrylate alkene groups;
- (C) a compound containing at least two expoxy groups;
- and
- (D) a Michael reaction catalyst base.
A process for preparing a cured coating comprising curing a mixture of:
- (A) a compound containing at least two acetoacetate methylene groups;
- (B) a compound containing at least two acrylate alkene groups;
- and
- (C) a compound containing at least two expoxy groups, in the presence of:
- (D) a Michael reaction catalyst base.
A cured coating prepared by a process comprising curing a mixture of:
- (A) a compound containing at least two acetoacetate methylene groups;
- (B) a compound containing at least two acrylate alkene groups;
- and
- (C) a compound containing at least two expoxy groups, in the presence of:
- (D) a Michael reaction catalyst base.
Dependencies are inferred from the claim text.