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US 5,854,332 AGranted
Aqueous urethane/acrylic resins with branched chain extension and coating compositions made therefrom
AssigneePPG Industries, Inc.
InventorsShanti Swarup, Anbazhagan Natesh, Norene E. Fortuna, Kurt G. Olson
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Abstract
Aqueous dispersions of urethane polymers and vinyl polymers (e.g., acrylics) that provide water-based coating compositions with good adhesion following humidity exposure are further improved by providing branching chain extension of the polyurethane. The branched polymers provide improved metallic pigment orientation in coating compositions. Branching is provided by the use of chain extending agents selected from polyamines having at least three primary amine groups and polyols having at least three hydroxyl groups. The vinyl monomers are polymerized in the presence of the aqueously dispersed polyurethane.
Claims19
A water reducible polyurethane-acrylic resin which comprises:
- (a) 20-90 percent by weight of a polyurethane selected from the group consisting of:
- (A) the reaction product of:
- (i) a first polyisocyanate having a linear carbon chain greater than C.sub.6 in length between two isocyanate groups;
- (ii) a second isocyanate different from he first polyisocyanate;
- (iii) a polyol for reaction with the isocyanates to form polyurethane;
- and
- (iv) a monomer having an anionic group and functionality reactive with isocyanate to provide water dispersibility for the polyurethane through salt formation and as such different from the polyol of (iii);
- and
- (B) the reaction product of:
- (v) a polyisocyanate;
- (vi) a polyhydroxy compound which is the reaction product of at least one monomer having a hydrocarbon group of at least six carbon atoms, where the polyhydroxy compound reacts with the polyisocyanate to form polyurethane;
- and
- (vii) a monomer having an anionic group and functionality reactive with isocyanate to provide water dispersibility for the polyurethane through salt formation and as such different from the polyhydroxy compound of (vi);
- the polyurethane (a) being further chain extended by reaction in water with a chain extending compound having at least three hydroxyl groups or at least three primary amine groups and being substantially free of tertiary amine groups to avoid discoloration in a coating composition having water reducible polyurethane-acrylic resin, whereby a branched polyurethane structure for (a) results from the chain extension;
- and
- (b) 10-80 percent by weight of the free radical polymerization product of a mixture of vinyl monomers polymerized in the presence of the branched polyurethane of (a);
- wherein the weight percentages are based on the total resin solids content of (a) plus (b).
14 more elements
An aqueous coating composition comprising:
- aqueous medium;
- reflective flake pigment;
- a film-forming resin comprising a water reducible polyurethane-acrylic resin which comprises:
- (a) 20-90 percent by weight of a polyurethane selected from the group consisting of:
- (A) the reaction product of:
- (i) a first polyisocyanate having a linear carbon chain greater than C.sub.6 in length between two isocyanate groups;
- (ii) a second isocyanate different from the first polyisocyanate;
- (iii) a polyol for reaction with the isocyanates to form polyurethane;
- and
- (iv) a monomer having an anionic group and functionality reactive with isocyanate to provide water dispersibility for the polyurethane through salt formation and as such different from the polyol of (iii);
- and
- (B) the reaction product of:
- (v) a polyisocyanate;
- (vi) a polyhydroxy compound which is the reaction product of at least one monomer which includes a hydrocarbon group of at least six carbon atoms, where the polyhydroxy compound reacts with the polyisocyanate to form polyurethane;
- and
- (vii) a monomer having an anionic group and functionality reactive with isocyanate to provide water dispersibility for the polyurethane through salt formation and as such different from the polyhydroxy compound of (vi);
- the polyurethane (a) being further chain extended by reaction in water with a compound having at least three hydroxyl groups or at least three primary amine groups and being substantially free of tertiary amine groups to avoid discoloration of the coating composition whereby a branched polyurethane structure for (a) results from the chain extension;
- and
- (b) 10-80 percent by weight of the free radical polymerization product of a mixture of vinyl monomers polymerized in the presence of the branched polyurethane of (a);
- wherein the weight percentages are based on the total resin solids content of (a) plus (b).
17 more elements
An aqueous coating composition comprising:
- aqueous medium;
- reflective flake pigment;
- a film-forming resin comprising a water reducible polyurethane-acrylic resin which comprises:
- (a) 20-90 percent by weight of a polyurethane selected from the group consisting of:
- (A) the reaction product of:
- (i) a first polyisocyanate having a linear carbon chain greater than C.sub.6 in length between two isocyanate groups;
- (ii) a second isocyanate different from the first polyisocyanate;
- (iii) a polyol comprising a combination of diols and polyols having at least three hydroxyl groups for reaction with the isocyanates to form polyurethane;
- and
- (iv) a monomer having an anionic group and functionality reactive with isocyanate to provide water dispersibility for the polyurethane through salt formation and as such different from the polyol of (iii);
- and
- (B) the reaction product of:
- (v) a polyisocyanate;
- (vi) a polyhydroxy compound which is the reaction product of an acid and a material selected from the group consisting of epoxy and polyol wherein at least one monomer includes a hydrocarbon group of at least six carbon atoms;
- (vii) a combination of diols and polyols having at least three hydroxyl groups and as such different from (vi) and (viii);
- and
- (viii) a monomer having an anionic group and functionality reactive with isocyanate to provide water dispersibility for the polyurethane through salt formation and as such different from the polyhydroxy compound of (vi);
- the polyurethane (a) having a branched structure from the formation of reaction products A or B or through chain extension with a polyamine having at least three primary amine groups or a polyol having at least three hydroxyl groups;
- and
- (b) 10-80 percent by weight of the free radical polymerization product of a mixture of vinyl monomers polymerized in the presence of the branched polyurethane of (a);
- wherein the weight percentages are based on the total resin solids content of (a) plus (b).
18 more elements
Dependencies are inferred from the claim text.