One pack low temperature cure coating compositions

Patent metadata

Field	Value
Publication number	US-11098220-B2
Application number	US-201414763662-A
Country	US
Kind code	B2
Filing date	Jan 28, 2014
Priority date	Jan 30, 2013
Publication date	Aug 24, 2021
Grant date	Aug 24, 2021

Abstract

This invention relates to coating compositions comprising at least one aminoplast crosslinker resin A, binder resins B that have active hydrogen functionality, and a catalyst composition C, wherein the catalyst composition C is a mixture of an organic sulfonic acid C1, and an amine C2 which may be primary, secondary, or tertiary, and which must have a pKa value of not more than 10, and preferably not less than 4, a process for the preparation thereof, and to a method of use thereof.

First claim

The invention claimed is:

1. A coating composition comprising at least one aminoplast crosslinker resin A, binder resins B, and a catalyst composition C,
wherein the catalyst composition C is a mixture of an organic sulfonic acid C1, and an amine C2 selected from the group consisting of 4-chloroaniline, p-ethylaniline, 4-picoline, and N-ethyl aniline,
wherein the binder resins B are hydroxy-functional polymers selected from the group consisting of alkyd resins, polyester resins, acrylic resins, acrylic-alkyd hybrids or acrylic-polyester hybrids, polyolefin polymers, and polyurethane polymers, wherein the polyurethane polymers are selected from the group consisting of polyether-polyurethanes, polyester-polyurethanes, polycarbonate-polyurethanes, and polyolefin-polyurethanes, and
wherein the organic sulfonic acid C1 is an aromatic sulfonic acid having at least one sulfonic acid group, —SO 3 H, bound to an aromatic carbon atom.

2. The coating composition of claim 1 wherein the at least one aminoplast crosslinker resin A comprises at least one at least partially etherified reaction product of melamine and formaldehyde wherein a ratio of an amount of substance n(CH 2 O) of combined formaldehyde to an amount of substance n(Mel) of melamine is in the range of from 4.5 mol/mol to 6.2 mol/mol, a ratio of an amount of substance n(RO) of alkyl ether groups in the aminoplast crosslinker resin A to the amount of substance n(Mel) of melamine is in the range of from 4 mol/mol to 6.0 mol/mol, and a mass fraction of monomers is in the range of from 30% to 65%, calculated as a ratio of a mass m(1) of monomers to the total mass m(A) of the aminoplast crosslinker resin A, excluding solvents, additives, and catalysts.

3. The coating composition of claim 1 wherein at least two aminoplast crosslinker resins A1 and A2 are present in the coating composition.

4. The coating composition of claim 3 wherein one of the aminoplast crosslinker resins, A1, comprises at least one at least partially etherified reaction product of melamine and formaldehyde wherein a ratio of an amount of substance n(CH 2 O) of combined formaldehyde to an amount of substance n(Mel) of melamine is in the range of from 5.55 mol/mol to 6.2 mol/mol, a ratio of an amount of substance n(RO) of alkyl ether groups in the aminoplast crosslinker resin A to the amount of substance n(Mel) of melamine is in the range of from 5 mol/mol to 5.6 mol/mol, and a mass fraction of monomers is in the range of from 35% to 55%, calculated as a ratio of a mass m(1) of monomers to the total mass of the aminoplast crosslinker resin A1, excluding solvents, additives, and catalysts.

5. The coating composition of claim 3 wherein one of the aminoplast crosslinker resins, A2, comprises at least one at least partially etherified reaction product of melamine and formaldehyde wherein a ratio of an amount of substance n(CH 2 O) of combined formaldehyde to an amount of substance n(Mel) of melamine is in the range of from 5.75 mol/mol to 6.5 mol/mol, a ratio of n amount of substance n(RO) of alkyl ether groups in the aminoplast crosslinker resin A2 to the amount of substance n(Mel) of melamine is in the range of from 4.5 mol/mol to 5.9 mol/mol, and a mass fraction of monomers is in the range of from 55% to 95%, calculated as a ratio of a mass m(1) of monomers to the total mass m(A) of the aminoplast crosslinker resin A2, excluding solvents, additives, and catalysts.

6. The coating composition of claim 3 wherein a ratio of the mass m(A1) of the aminoplast crosslinker resin A1 to the mass m(A2) of the aminoplast crosslinker resin A2 is from 5: 5 to 9: 1.

7. The coating composition of claim 1 , wherein the at least one aminoplast crosslinker resin A has alkyl ether groups comprising at least two different alkyl groups.

8. The coating composition of claim 1 , wherein the organic sulfonic acid C1 is selected from the group consisting of toluene sulfonic acid, dodecylbenzene sulfonic acid, dinonylnaphthalene sulfonic acid, dinonylnaphthalene disulfonic acid, and mixtures thereof.

9. A process for preparing the coating composition of claim 1 , which process comprises
in a first step, preparing the catalyst composition C by mixing the organic sulfonic acid C1, optionally dissolved in an organic solvent selected from aliphatic linear or branched alcohols having from one to six carbon atoms, with the amine C2 selected from the group consisting of 4-chloroaniline, p-ethylaniline, 4-picoline, and N-ethyl aniline,
in a second step, admixing the catalyst composition C to an aminoplast crosslinker resin A, to form a mixture AC,
and in a third step, admixing the mixture AC to the binder resins B, or a solution of the binder resins B in an inert solvent L,
wherein organic sulfonic acid C1 is an aromatic sulfonic acid having at least one sulfonic acid group, —SO 3 H, bound to an aromatic carbon atom.

10. The process of claim 9 wherein a ratio of an amount of aminic nitrogen atoms in the amine C2 to an amount of acidic hydrogen atoms in the organic sulfonic acid C1 is between 1.0 mol/mol and 1.5 mol/mol.

11. The process of claim 9 , wherein the organic sulfonic acid C1 is selected from the group consisting of toluene sulfonic acid, dodecylbenzene sulfonic acid, dinonylnaphthalene sulfonic acid, dinonylnaphthalene disulfonic acid, and mixtures thereof.

12. A method of use of the coating composition as claimed in claim 1 , which method comprises the steps of
coating a substrate with the coating composition of claim 1 to prepare a coating film on the substrate, and
curing the coating film by applying heat to provide a curing temperature between 50° C. and 100° C.

Assignees

• Allnex Ip Sarl
• Allnex Netherlands Bv

Inventors

• Wu Kuang-Jong
• Brogan John Colin
• Lin Lon-Tang Wilson

Classifications

• C08G12/427

  Melamine · CPC title

• C09D161/32

  Modified amine-aldehyde condensates · CPC title

• C09D133/14 Primary

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

• B05D3/007

  After-treatment · CPC title

• C08K5/42

  Sulfonic acids; Derivatives thereof · CPC title