Solvent-borne coating compositions, coatings formed therefrom, and methods of forming such coatings

Patent metadata

Field	Value
Publication number	US-11851573-B2
Application number	US-201917290214-A
Country	US
Kind code	B2
Filing date	Nov 1, 2019
Priority date	Nov 1, 2018
Publication date	Dec 26, 2023
Grant date	Dec 26, 2023

Abstract

A coating composition includes: (a) a carboxylic acid functional polyol polymer; (b) a melamine-formaldehyde crosslinker reactive with the carboxylic acid functional polyol polymer; (c) an acid catalyst; and (d) a non-aqueous liquid medium. The carboxylic acid functional polyol polymer has an acid value within a range of from 30 to 120 mg KOH/g and a hydroxyl value within a range of from 60 to 150 mg KOH/g. The melamine-formaldehyde crosslinker includes imino and methylol groups that together make up 35 mole % or less of the total functionality of the melamine-formaldehyde crosslinker, and butyl groups and isobutyl groups that together make up 5 mole % or greater of the total functionality of the melamine-formaldehyde crosslinker. The coating composition cures at a temperature of 100° C. or less.

First claim

The invention claimed is:

1. A coating composition comprising:
(a) a carboxylic acid functional polyol polymer comprising an acid value within a range of from 50 to 95 mg KOH/g and a hydroxyl value within a range of from 60 to 150 mg KOH/g;
(b) a melamine-formaldehyde crosslinker reactive with the carboxylic acid functional polyol polymer, wherein the melamine-formaldehyde crosslinker comprises imino and methylol groups that together comprise 35 mole % or less of the total functionality of the melamine-formaldehyde crosslinker, and wherein the melamine-formaldehyde crosslinker comprises butyl groups and isobutyl groups that together comprise 5 mole % or greater of the total functionality of the melamine-formaldehyde crosslinker;
(c) an acid catalyst;
(d) a non-aqueous liquid medium, and
(e) a polyester polyol;
wherein the coating composition cures at a temperature of 100° C. or less, and wherein when the composition is applied to a substrate and cured to form a cured coating, the cured coating demonstrates a solvent resistance of greater than 200 in methyl ethyl ketone double rubs test according to ASTM D5042-15.

2. The coating composition of claim 1 , wherein the carboxylic acid functional polyol polymer is obtained from reactants comprising: (i) an ethylenically unsaturated compound comprising hydroxyl functional groups; (ii) an ethylenically unsaturated compound comprising carboxylic acid functional groups, or an anhydride thereof; and (iii) an ethylenically unsaturated compound that is different from (i) and (ii).

3. The coating composition of claim 1 , wherein the acid catalyst comprises 0.5 to 5 weight % of the coating composition, based on the total solids weight of all hydroxyl functional polymers in the coating composition.

4. The coating composition of claim 1 , wherein the melamine-formaldehyde crosslinker comprises from 12 to 30 weight % of the coating composition, based on the resin solids weight of the coating composition.

5. The coating composition of claim 1 , wherein the carboxylic acid functional polyol polymer has a hydroxyl value within a range of from 60 to 100 mg KOH/g.

6. The coating composition of claim 1 , wherein the carboxylic acid functional polyol polymer has glass transition temperature within a range of from −20 to 50° C.

7. The coating composition of claim 1 , wherein the carboxylic acid functional polyol polymer has a weight average molecular weight of greater than 5,000 g/mol.

8. The coating composition of claim 2 , wherein the ethylenically unsaturated compound comprising hydroxyl functional groups comprises at least 10 weight % of the reactants, based on the total solids weight of the reactants used to form the carboxylic acid functional polyol polymer.

9. The coating composition of claim 2 , wherein the ethylenically unsaturated compound comprising carboxylic acid functional groups, or the anhydride, comprises at least 5 weight % of the reactants, based on the total solids weight of the reactants used to form the carboxylic acid functional polyol polymer.

10. The coating composition of claim 2 , wherein the ethylenically unsaturated compound that is different from (i) and (ii) comprises a multi-ethylenically unsaturated compound, a mono-ethylenically unsaturated compound having an abstractable hydrogen, or a combination thereof.

11. The coating composition of claim 10 , wherein the ethylenically unsaturated compound that is different from (i) and (ii) comprises at least two different mono-ethylenically unsaturated compounds having an abstractable hydrogen.

12. The coating composition of claim 2 , wherein the ethylenically unsaturated compound that is different from (i) and (ii) comprises at least 50 weight % of the reactants, based on the total solids weight of the reactants used to form the carboxylic acid functional polyol polymer.

13. The coating composition of claim 1 , wherein the polyester polyol comprises from 30 to 55 weight % of the coating composition, based on the resin solids weight of the coating composition.

Assignees

• Ppg Ind Ohio Inc

Inventors

• Wo Yaqi
• Fenn David R
• Luchansky Matthew S
• Swarup Shanti
• Wargo Diane L
• Xu Xiangling

Classifications

• C09D133/08 Primary

  Homopolymers or copolymers of acrylic acid esters · CPC title

• B05D7/542

  the two layers being cured or baked together · CPC title

• C08F220/06

  Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof · CPC title

• C08F220/1808

  C8-(meth)acrylate, e.g. isooctyl (meth)acrylate or 2-ethylhexyl (meth)acrylate · CPC title

• C08F220/1811

  C10or C11-(Meth)acrylate, e.g. isodecyl (meth)acrylate, isobornyl (meth)acrylate or 2-naphthyl (meth)acrylate · CPC title