Curable coating compositions containing poly activated methylene resins and polyisocyanates

Patent metadata

Field	Value
Publication number	US-2018282575-A1
Application number	US-201615759162-A
Country	US
Kind code	A1
Filing date	Sep 9, 2016
Priority date	Sep 11, 2015
Publication date	Oct 4, 2018
Grant date	—

Abstract

A curable coating composition includes: (a) a polymer including at least two active methylene functional groups; (b) a polyisocyanate crosslinker; and (c) a transition metal catalyst. Substrates at least partially coated with these coating compositions are further disclosed. Methods for preparing the coating are further disclosed. Multi-layer coatings including these coating compositions are further disclosed.

First claim

The invention claimed is:

1 . A curable coating composition comprising: (a) a polymer comprising at least two active methylene functional groups; (b) a polyisocyanate crosslinker; and (c) a transition metal catalyst.

2 . The curable coating composition of claim 1 , wherein the active methylene functional groups comprise at least one acetoacetate functional group.

3 . The curable coating composition of claim 1 or 2 , wherein the polymer (a) further comprises at least one hydroxyl, carboxyl, epoxy, alkoxysilane, and/or anhydride functional group.

4 . The curable coating composition of any of the preceding claims, wherein the transition metal catalyst comprises at least one of a zinc complex, a nickel complex, and a cobalt complex.

5 . The curable coating composition of any of the preceding claims, further comprising a compound (d) different from polymer (a) comprising at least one active methylene functional group.

6 . The curable coating composition of any of the preceding claims, wherein polymer (a) comprises at least one polyacetoacetate-containing polyacrylate or polyacetoacetate-containing polyester, or both.

7 . The curable coating composition of claim 6 , wherein the polymer (a) comprises a polyacetoacetate-containing polyacrylate, wherein the polyacrylate comprises less than 85 weight % of monomers the homopolymers thereof have a glass transition temperature (Tg) of less than −40° C.

8 . The curable coating composition of any of the preceding claims, wherein the polyisocyanate crosslinker comprises isophorone diisocyanate, 1,6-hexamethylenediisocyanate, isocyanurates, iminooxadiazindiones, biurets, allophanates, uretdiones, dimers, trimers, and/or mixture thereof.

9 . The curable coating composition of any of the preceding claims, wherein when the coating composition is applied to a substrate as a coating and cured, the cured coating exhibits a maximum color change of 3 ΔE units after 1,000 hours of SAE J2527 durability testing.

10 . The curable coating composition of any of the preceding claims, wherein, when the coating composition is applied to a substrate as a coating and cured, the difference in b* between the cured coating and the coating composition without transition metal catalyst is less than 1.

11 . A substrate at least partially coated with a coating deposited from the curable coating composition of any of claims 1 - 10 .

12 . A multi-layer coating comprising: (a) a first coating layer prepared from a curable coating composition according to any of claims 1 - 10 ; and (b) a second coating layer, the second coating layer prepared from a coating composition that is different from (a) and which comprises a second film-forming resin.

13 . A method for preparing a coating comprising: (i) applying the curable coating composition of any of claims 1 - 10 onto at least a portion of a substrate;
and (ii) curing the curable coating composition at at least 20° C. for less than 4 hours to form a coating on the substrate.

14 . The method of claim 13 , wherein the substrate is metal.

15 . The method of claim 14 , wherein the metal is a pretreated metal.

Assignees

• Ppg Ind Ohio Inc

Inventors

• Breon Jonathan P
• Deng Jun
• Li Linlin
• Schwendeman John E
• Millero Jr Edward R

Classifications

• C08G18/2895

  Compounds containing active methylene groups · CPC title

• C08G18/6225

  Polymers of esters of acrylic or methacrylic acid · CPC title

• C09D175/04 Primary

  Polyurethanes · CPC title

• B05D3/007

  After-treatment · CPC title

• C09D133/14

  of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen · CPC title