Coating compositions comprising diisocyanate chain extended bisaspartates

Patent metadata

Field	Value
Publication number	US-10125290-B2
Application number	US-201515120267-A
Country	US
Kind code	B2
Filing date	Feb 16, 2015
Priority date	Feb 25, 2014
Publication date	Nov 13, 2018
Grant date	Nov 13, 2018

Abstract

This invention relates to a coating composition, a method for coating of a metallic substrate as well as the use of a chain-extended aspartate prepolymer for improving the early hardness of the coating composition and in a two-component coating composition.

First claim

The invention claimed is:

1. A coating composition comprising:
a) a chain-extended aspartate prepolymer, wherein the chain-extended aspartate prepolymer
x) is free of isocyanate groups,
xi) has an NH equivalent weight of from 250 to 1,000 g, and
xii) is a reaction product of
i) a mixture comprising at least one di-aspartic acid ester and at least one amino-functional mono-aspartic acid ester, wherein the molar ratio between the at least one di-aspartic acid ester and the at least one amino-functional mono-aspartic acid ester is from 99.5:0.5 to 50:50, and
ii) at least one cycloaliphatic polyisocyanate, and

b) at least one curing agent having free isocyanate groups.

2. The coating composition of claim 1 , wherein the at least one di-aspartic acid ester and/or the at least one amino-functional mono-aspartic acid ester is/are a reaction product of at least one dialkyl maleate and/or dialkyl fumarate and at least one primary diamine.

3. The coating composition of claim 1 , wherein the at least one di-aspartic acid ester and/or the at least one amino-functional mono-aspartic acid ester has/have been obtained by reacting the at least one dialkyl maleate and/or dialkyl fumarate and the at least one primary diamine in an equivalent ratio of dialkyl maleate and/or dialkyl fumarate to primary diamine from 2:1 to 1:4.

4. The coating composition of claim 2 , wherein:
the at least one dialkyl maleate is selected from the group of dimethyl maleate, diethyl maleate, di-n-butyl maleate, di-iso-butyl maleate, di-tert-butyl maleate, diamyl maleate, di-n-octyl maleate, dilauryl maleate, dicyclohexyl maleate, di-tert-butylcyclohexyl maleate and mixtures thereof; or
the at least one dialkyl fumarate is selected from the group comprising dimethyl fumarate, diethyl fumarate, di-n-butyl fumarate, di-iso-butyl fumarate, di-tert-butyl fumarate, diamyl fumarate, di-n-octyl fumarate, dilauryl fumarate, dicyclohexyl fumarate, di-tert-butylcyclohexyl fumarate and mixtures thereof.

5. The coating composition of claim 2 , wherein the at least one primary diamine is selected from the group of ethylene diamine, 1,2-diaminopropane, 1,4-diaminobutane, 1,3-diaminopentane, 1,6-diaminohexane, 2,5-diamino-2,5-dimethylhexane, 2,2,4- and 2,4,4-trimethyl-1, 6-diaminohexane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,3- and 1,4-cyclohexane diamine, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane (IPDA), 2,4- and 2,6-hexahydrotoluylene diamine, 2,4′- and 4,4′-diamino-dicyclohexyl methane and 3,3′-dialkyl-4, 4′-diaminodicyclohexylmethanes, and mixtures thereof.

6. The coating composition of claim 1 , wherein the at least one cycloaliphatic polyisocyanate is selected from 1 socyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (IPDI), 4,4′-diisocyanatocyclohexylmethane, cyclotrimers or biurets of 1 socyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane, 4,4′-diisocyanatocyclohexylmethane and mixtures thereof.

7. The coating composition of claim 1 , wherein the chain-extended aspartate prepolymer has been obtained by reacting the mixture comprising at least one di-aspartic acid ester and at least one amino-functional mono-aspartic acid ester with the at least one cycloaliphatic polyisocyanate in an equivalent ratio of NH and NH 2 groups in the mixture to NCO groups of the at least one cycloaliphatic polyisocyanate from 2.0:0.2 to 2.0:1.8.

8. The coating composition of claim 1 , wherein the chain-extended aspartate prepolymer comprises an equivalent ratio of aspartate groups to urea groups from 10:1 to 1:0.9.

9. The coating composition of claim 1 , wherein the at least one curing agent having free isocyanate groups is selected from the group of hexamethylene diisocyanate (HDI), 1 socyanato-3,3,5-trimethyl-5-isocyanatomethyl-cyclohexane (IPDI), bis(isocyanatocyclohexyl)-methane and their derivatives, 1,1,6,6-tetramethyl-hexamethylene diisocyanate, p- or m-tetramethylxylylene diisocyanate, 2,2′,5 trimethylhexane diisocyanate and mixtures thereof and reaction products thereof.

10. The coating composition of claim 1 , wherein the coating composition further comprises at least one compound selected from the group of curing catalysts, antioxidants, additives, pigments, extenders, UV screeners, compounds with at least one alkoxy silane group or at least one epoxy group, hydroxyl functional binders as acrylics, polyesters, HALS derivatives, inorganic rheology control agents, and mixtures thereof.

11. The coating composition claim 1 , wherein the coating composition is a two-component coating composition.

12. A method for coating of a metallic substrate, the method comprising at least the steps of:
a) applying the coating composition of claim 1 to at least a portion of a metallic substrate to be coated, and
b) curing the coating composition of step a).

13. The method of claim 12 , wherein multiple layers of coating compositions are applied to at least a portion of a metallic substrate and at least one of the layers comprises the coating composition and the multiple layers are applied either wet in wet or by first curing one layer before applying the next layer of the multiple layers.

14. A coating composition utilizing the chain-extended aspartate prepolymer of claim 1 for improving the early hardness of a coating composition.

15. A two-component coating composition utilizing the coating composition of claim 1 .

16. The coating composition of claim 3 , wherein:
the at least one dialkyl maleate is selected from the group of dimethyl maleate, diethyl maleate, di-n-butyl maleate, di-iso-butyl maleate, di-tert-butyl maleate, diamyl maleate, di-n-octyl maleate, dilauryl maleate, dicyclohexyl maleate, di-tert-butylcyclohexyl maleate and mixtures thereof; or
the at least one dialkyl fumarate is selected from the group of dimethyl fumarate, diethyl fumarate, di-n-butyl fumarate, di-iso-butyl fumarate, di-tert-butyl fumarate, diamyl fumarate, di-n-octyl fumarate, dilauryl fumarate, dicyclohexyl fumarate, di-tert-butylcyclohexyl fumarate and mixtures thereof.

17. The coating composition of claim 3 , wherein the at least one primary diamine is selected from the group of ethylene diamine, 1,2-diaminopropane, 1,4-diaminobutane, 1,3-diaminopentane, 1,6-diaminohexane, 2,5-diamino-2,5-dimethylhexane, 2,2,4- and 2,4,4-trimethyl-1, 6-diaminohexane, 1,11-diaminoundecane, 1,12-diaminododecane, 1,3- and 1,4-cyclohexane diamine, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane (IPDA), 2,4- and 2,6-hexahydrotoluylene diamine, 2,4′- and 4,4′-diamino-dicyclohexyl methane and 3,3′-dialkyl-4, 4′-diaminodicyclohexylmethanes, and mixtures thereof.

18. The coating composition of claim 1 , further comprising an antioxidant component.

19. The coating composition of claim 18 , wherein the antioxidant component comprises (A1) at least one sterically hindered phenol antioxidant and (A2) at least one organophosphite antioxidant.

20. The coating composition of claim 5 , wherein the at least one primary diamine is selected from the group of 3, 3′-dimethyl-4, 4′-diaminodicyclohexyl methane and 3,3′-diethyl-4,4′-diaminodicyclohexylmethane, 2-methyl-1,5-pentanediamine and 1,3- and 1,4 xylylenediamine, tetramethyl xylylenediamine, 4,4′-diaminodicyclohexyl methane (PACM), and mixtures thereof.

Assignees

• Axalta Coating Systems Ip Co

Inventors

• Enkisch-Krug Charlotte
• Flosbach Carmen
• Vaes Ann
• Tanghe Leen
• Huybrechts Jozef

Classifications

• C08G18/8058

  with compounds of C08G18/3819 · CPC title

• C08G18/755

  and at least one isocyanate or isothiocyanate group linked to a secondary carbon atom of the cycloaliphatic ring, e.g. isophorone diisocyanate · CPC title

• C09D175/02 Primary

  Polyureas · CPC title

• B05D7/14

  to metal, e.g. car bodies (involving a chemical reaction between the metal and the coating C23) · CPC title

• C08G18/3253

  being in latent form · CPC title