Coatings with flexible hyperbranched polyols

Patent metadata

Field	Value
Publication number	US-9938429-B2
Application number	US-201414335373-A
Country	US
Kind code	B2
Filing date	Jul 18, 2014
Priority date	Jul 18, 2014
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

A coating composition includes a flexible hyperbranched polyol preparable by (a) reacting a polyol comprising at least three hydroxyl groups with an aliphatic dicarboxylic acid having from 6 to 36 carbon atoms or an esterifiable derivative of the aliphatic dicarboxylic acid to form a hydroxyl-functional first intermediate product; (b) reacting the first intermediate product with a cyclic carboxylic acid anhydride to form a carboxylic acid-functional second intermediate product; and (c) reacting the second intermediate product with an epoxide-functional compound having one epoxide group to form the hyperbranched polyol. The coating composition may be cured to a coating layer having excellent flexibility.

First claim

What is claimed is:

1. A coating composition, comprising:
a flexible hyperbranched polyol, comprising:
a central diester unit of formula (I):
—O—C(O)—R—C(O)—O—

wherein R is an aliphatic hydrocarbon group or dimer fatty acid group having from 4 to 34 carbons; and
the flexible hyperbranched polyol is prepared by (a) reacting a polyol comprising at least three hydroxyl groups with an aliphatic dicarboxylic acid having from 6 to 36 carbon atoms or an esterifiable derivative of the aliphatic dicarboxylic acid to form a hydroxyl-functional first intermediate product; (b) reacting the first intermediate product with a cyclic carboxylic acid anhydride to form a carboxylic acid-functional second intermediate product; and (c) reacting the second intermediate product with an epoxide-functional compound having one epoxide group to form the hyperbranched polyol.

2. The coating composition according to claim 1 , wherein a ratio of moles of the polyol to moles of the dicarboxylic acid or esterifiable derivative of the aliphatic dicarboxylic acid in a) is from about 2.0 to about 2.2 moles of the polyol per mole of the dicarboxylic acid or esterifiable derivative of the aliphatic dicarboxylic acid.

3. The coating composition according to claim 1 , wherein an equivalent ratio in (b) of hydroxyl groups of the first intermediate product to anhydride groups of the cyclic carboxylic acid anhydride is from about 1.0 to about 1.25 equivalents of hydroxyl groups per carboxylic anhydride groups.

4. The coating composition according to claim 1 , wherein an equivalent ratio in (c) of carboxylic acid groups of the second intermediate product to epoxide groups of the epoxide-functional compound is from about 1.0 to about 2.5 equivalents of carboxylic acid groups per equivalents epoxide groups.

5. The coating composition according to claim 1 , wherein the coating composition is aqueous and wherein the equivalent ratio in (c) of carboxylic acid groups of the second intermediate product to epoxide groups of the epoxide-functional compound is from about 1.1 to about 2.5 equivalents of carboxylic acid groups per equivalents epoxide groups and the unreacted carboxylic acid groups are at least partially neutralized with a base.

6. A method of coating a substrate, comprising applying to the substrate a coating composition according to claim 1 to form a coating layer and curing the coating layer.

7. The method according to claim 6 , wherein the coating layer is pigmented.

8. The method according to claim 7 , wherein a clearcoat composition is applied over the coating layer to form a clearcoat layer and the coating layer and clearcoat layer are cured together.

9. The method according to claim 6 , wherein the coating layer is unpigmented.

10. The method according to claim 6 , wherein the coating layer is applied as a refinish coating on the substrate.

11. A method of making a flexible hyperbranched comprising:
(a) reacting a polyol comprising at least three hydroxyl groups with an aliphatic dicarboxylic acid having from 6 to 36 carbon atoms or an esterifiable derivative of the aliphatic dicarboxylic acid to form a hydroxyl-functional first intermediate product having a central diester unit of formula (I):
—O—C(O)—R—C(O)—O—

wherein R is an aliphatic hydrocarbon group or dimer fatty acid group having from 4 to 34 carbons;
(b) reacting the first intermediate product with a cyclic carboxylic acid anhydride to form a carboxylic acid-functional second intermediate product; and
(c) reacting the second intermediate product with an epoxide-functional compound having one epoxide group to form the hyperbranched polyol.

12. The method according to claim 11 , wherein a ratio of moles of the polyol to moles of the dicarboxylic acid or esterifiable derivative of the aliphatic dicarboxylic acid in a) is from about 2.0 to about 2.2 moles of the polyol per mole of the dicarboxylic acid or esterifiable derivative of the aliphatic dicarboxylic acid.

13. The method according to claim 11 , wherein an equivalent ratio in (b) of hydroxyl groups of the first intermediate product to anhydride groups of the cyclic carboxylic acid anhydride is from about 1.0 to about 1.25 equivalents of hydroxyl groups per carboxylic anhydride groups.

14. The method according to claim 11 , wherein an equivalent ratio in (c) of carboxylic acid groups of the second intermediate product to epoxide groups of the epoxide-functional compound is from about 1.0 to about 2.5 equivalents of carboxylic acid groups per equivalents epoxide groups.

15. The method according to claim 11 , wherein the equivalent ratio in (c) of carboxylic acid groups of the second intermediate product to epoxide groups of the epoxide-functional compound is from about 1.1 to about 2.5 equivalents of carboxylic acid groups per equivalents epoxide groups and the unreacted carboxylic acid groups are at least partially neutralized with a base and the hyperbranched polyol is dispersed in an aqueous medium.

Assignees

• Basf Coatings Gmbh
• BASF Coating GmbH

Inventors

• Colyer Emerson Keith

Classifications

• C09D201/005

  Dendritic macromolecules · CPC title

• C09D167/00 Primary

  Coating compositions based on polyesters obtained by reactions forming a carboxylic ester link in the main chain (based on polyester-amides C09D177/12; based on polyester-imides C09D179/08); Coating compositions based on derivatives of such polymers · CPC title

• C08G63/668 Primary

  derived from polycarboxylic acids and polyhydroxy compounds · CPC title

• C08G63/78

  Preparation processes · CPC title

• B05D7/532

  the two layers being cured or baked together, i.e. wet on wet · CPC title