Catalysts for polyurethane coating compounds

Patent metadata

Field	Value
Publication number	US-9963538-B2
Application number	US-201314654734-A
Country	US
Kind code	B2
Filing date	Dec 18, 2013
Priority date	Jan 7, 2013
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

The present invention relates to new catalysts for curing solventborne or solvent-free coating compositions, such as 2-component polyurethane coating materials or 2-component polyurethane adhesives.

First claim

The invention claimed is:

1. A method of coating a substrate, the method comprising:
applying at least one coating composition to the substrate in a desired thickness, wherein the at least one coating composition comprises the following components:
(A) at least one polyisocyanate obtained by reacting at least one monomeric isocyanate, wherein the at least one polyisocyanate is at least one selected from the group consisting of 1,6-hexamethylenediisocyanate based isocyanurate and 1,6-hexamethylenediisocyanate based biuret,
(B) at least one binder comprising at least two isocyanate-reactive groups, and having a number-average molecular weight Mn of from 1000 to 5000 g/mol and an OH number of from 80 to 160 mg KOH/g, wherein the at least one binder is a polyacrylate polyol, and
(C) 1-ethyl-3-methyl-imidazolium benzoate,
wherein a molar ratio of isocyanate groups of the component (A) to isocyanate-reactive groups of the component (B) is from 0.9:1 to 1.2:1, and
wherein an amount of 1-ethyl-3-methyl-imidazolium benzoate (C) is from 300 to 4,000 ppm by weight,

optionally drying the at least one coating composition applied to the substrate, by at least partly removing volatile constituents; followed by
curing the at least one coating composition applied to the substrate.

2. The method according to claim 1 , comprising mixing a premix comprising
(B) the at least one binder, and
(C) 1-ethyl-3-methyl-imidazolium benzoate,

shortly before application to the substrate, with
(A) the at least one polyisocyanate,
and then
optionally conducting the drying of the at least one coating composition applied to the substrate, by at least partial removal of volatile constituents, followed by
the curing of the at least one coating composition applied to the substrate.

3. The method according to claim 1 , wherein the curing is carried out at a temperature of below 110° C.

4. The method according to claim 1 , wherein the at least one coating composition has a solids content of more than 58% with a flow time (DIN 4 cup) of 20 seconds at 23° C.

5. The method of claim 1 , wherein the at least one coating composition is in a form selected from the group consisting of a paint, a varnish, an adhesive, a primer and a troweling composition.

6. The method according to claim 1 , wherein a molar ratio of isocyanate groups of the component (A) to isocyanate-reactive groups of the component (B) is from 0.9:1 to 1.1:1.

7. A coating material for coating a substrate, the coating material comprising the following components:
(A) at least one polyisocyanate obtained by reacting at least one monomeric isocyanate, wherein the at least one polyisocyanate is at least one selected from the group consisting of 1,6-hexamethylenediisocyanate based isocyanurate and 1,6-hexamethylenediisocyanate based biuret,
(B) at least one binder comprising at least two isocyanate-reactive groups, and having a number-average molecular weight Mn of from 1000 to 5000 g/mol and an OH number of from 80 to 160 mg KOH/g, wherein the at least one binder is a polyacrylate polyol, and
(C) 1-ethyl-3-methyl-imidazolium benzoate,
wherein a molar ratio of isocyanate groups of the component (A) to isocyanate-reactive groups of the component (B) is from 0.9:1 to 1.2:1, and
wherein an amount of 1-ethyl-3-methyl-imidazolium benzoate (C) is from 300 to 4,000 ppm by weight.

8. A premix for coating a substrate, the premix comprising:
(B) at least one binder comprising at least two isocyanate-reactive groups, and having a number-average molecular weight Mn of from 1000 to 5000 g/mol and an OH number of 80 to 160 mg KOH/g, wherein the at least one binder is a polyacrylate polyol,
(C) 1-ethyl-3-methyl-imidazolium benzoate,
wherein an amount of 1-ethyl-3-methyl-imidazolium benzoate (C) is from 300 to 4,000 ppm by weight.

Assignees

• Basf Se

Inventors

• Schaefer Harald
• Eichfelder Andreas
• Gaspar Boris
• Pauen Thorsten

Classifications

• C08G18/2027

  having two nitrogen atoms in the ring · CPC title

• C08G18/6225 Primary

  Polymers of esters of acrylic or methacrylic acid · CPC title

• C09D175/04

  Polyurethanes · CPC title

• C08G18/792

  formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates · CPC title