Aqueous dispersions, coating compositions formed with aqueous dispersions, and multi-layer coatings
AssigneePPG Industries Ohio, Inc.
InventorsXiangling Xu, Hongying Zhou, Richard J. Sadvary, Shanti Swarup
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Abstract
An aqueous dispersion includes an aqueous medium and self-crosslinkable core-shell particles dispersed in the aqueous medium. The core-shell particles include (1) a polymeric core at least partially encapsulated by (2) a polymeric shell having urethane linkages, keto and/or aldo functional groups, and hydrazide functional groups. Further, the polymeric core is covalently bonded to at least a portion of the polymeric shell.
Claims33
An aqueous dispersion comprising an aqueous medium and self-crosslinkable core-shell particles dispersed in the aqueous medium, wherein the core-shell particles comprise (1) a polymeric core at least partially encapsulated by (2) a polymeric shell comprising urethane linkages, keto and/or aldo functional groups, and hydrazide functional groups, and
- wherein the polymeric core is covalently bonded to at least a portion of the polymeric shell, and
- wherein the self-crosslinkable core-shell particles are formed from a mixture of reactants comprising:
- (a) isocyanate-functional ethylenically unsaturated polyurethane prepolymers;
- (b) a Michael addition reaction product of ethylenically unsaturated monomers comprising a keto and/or aldo functional group, and a compound comprising at least two amino groups;
- (c) a hydrazide functional component;
- and (d) ethylenically unsaturated monomers.
A multi-layer coating comprising:
- a substrate;
- a first basecoat layer formed from a first basecoat composition comprising an aqueous medium and self-crosslinkable core-shell particles dispersed in the aqueous medium, wherein the self-crosslinkable core-shell particles comprise (1) a polymeric core at least partially encapsulated by (2) a polymeric shell comprising urethane linkages, keto and/or aldo functional groups, and hydrazide functional groups;
- and
- a second basecoat layer formed from a second basecoat composition comprising an aqueous medium and non-self-crosslinkable core-shell particles and a polyhydrazide dispersed in the aqueous medium, wherein the non-self-crosslinkable core-shell particles comprise (1) a polymeric core comprising keto and/or aldo functional groups that is at least partially encapsulated by (2) a polymeric shell comprising urethane linkages,
- wherein the polymeric core of the core-shell particles of the first basecoat composition and the second basecoat composition are each independently covalently bonded to at least a portion of the polymeric shell of the core-shell particles, and
- wherein:
- (i) the first basecoat layer is formed over at least a portion of the substrate and the second basecoat layer is formed over at least a portion of the first coating layer;
- or (ii) the second basecoat layer is formed over at least a portion of the substrate and the first basecoat layer is formed over at least a portion of the second basecoat layer.
An aqueous dispersion comprising an aqueous medium and self-crosslinkable core-shell particles dispersed in the aqueous medium, wherein the core-shell particles comprise (1) a polymeric core at least partially encapsulated by (2) a polymeric shell comprising urethane linkages, keto and/or aldo functional groups, and hydrazide functional groups,
- wherein the polymeric core is covalently bonded to at least a portion of the polymeric shell, and
- wherein the polymeric core of the self-crosslinkable core-shell particles is completely free of keto and/or aldo functional groups.
A coating composition comprising an aqueous dispersion comprising an aqueous medium and self-crosslinkable core-shell particles dispersed in the aqueous medium, wherein the core-shell particles comprise (1) a polymeric core at least partially encapsulated by (2) a polymeric shell comprising urethane linkages, keto and/or aldo functional groups, and hydrazide functional groups,
- wherein the polymeric core is covalently bonded to at least a portion of the polymeric shell, and
- wherein the coating composition further comprises non-self-crosslinkable core-shell particles, a (meth)acrylic resin, or a combination thereof.
Dependencies are inferred from the claim text.