Polyisocyanate composition for coatings

Patent metadata

Field	Value
Publication number	US-2022010053-A1
Application number	US-201917294777-A
Country	US
Kind code	A1
Filing date	Nov 21, 2019
Priority date	Nov 28, 2018
Publication date	Jan 13, 2022
Grant date	—

Abstract

The present invention relates to a polyisocyanate composition, comprising a mixture of ≥60 wt. %, relative to the total weight of the mixture, of at least one polyisocyanate based on pentamethylene diisocyanate and ≤40 wt. %, relative to the total weight of the mixture, of at least one polyisocyanate based on a cycloaliphatic diisocyanate and and/or of at least one polyisocyanate based on pentamethylene diisocyanate and at least one cycloaliphatic diisocyanate, the polyisocyanate composition having a residual monomer content of monomer diisocyanates below 0.5 wt. %, relative to the total weight of the polyisocyanate composition.

First claim

1 . A polyisocyanate composition comprising a mixture of ≥60 wt %, based on the total weight of the mixture, of at least one polyisocyanate based on pentamethylene diisocyanate and ≤40 wt %, based on the total weight of the mixture, of at least one polyisocyanate based on a cycloaliphatic diisocyanate or of at least one polyisocyanate based on pentamethylene diisocyanate and at least one cycloaliphatic diisocyanate, wherein the polyisocyanate composition has a residual monomer content of monomeric diisocyanates of below 0.5 wt %, based on the total weight of the polyisocyanate composition.

2 . The polyisocyanate composition as claimed in claim 1 , wherein the mixture comprises ≥70 wt %, based on the total weight of the mixture, of the at least one polyisocyanate based on pentamethylene diisocyanate, and fractions making up the balance to 100 wt % consist of the at least one polyisocyanate based on a cycloaliphatic diisocyanate or of the at least one polyisocyanate based on pentamethylene diisocyanate and at least one cycloaliphatic diisocyanate.

3 . The polyisocyanate composition as claimed in claim 1 , wherein the mixture of the polyisocyanate composition comprises ≥2 wt %, based on the total weight of the mixture, of the at least one polyisocyanate based on a cycloaliphatic diisocyanate or of the at least one polyisocyanate based on pentamethylene diisocyanate and at least one cycloaliphatic diisocyanate.

4 . The polyisocyanate composition as claimed in claim 1 , wherein the polyisocyanate based on pentamethylene diisocyanate and at least one cycloaliphatic diisocyanate comprises to an extent of ≥50 wt %, of at least one cycloaliphatic diisocyanate.

5 . The polyisocyanate composition as claimed in claim 4 , wherein the cycloaliphatic diisocyanate is selected from the group consisting of 1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, 2,4--diisocyanato-1-methylcyclohexane, 2,6-diisocyanato-1-methylcyclohexane, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane, 4,4′-diisocyanatodicyclohexylmethane, 2,4′-diisocyanatodicyclohexylmethane, 1-isocyanato-1-methyl-4(3)-isocyanatomethylcyclohexane, and bis(isocyanatomethyl)norbornane.

6 . The polyisocyanate composition as claimed in claim 1 , wherein the polyisocyanate composition consists comprises to an extent of ≥70 wt %, of the mixture.

7 . A process for producing a polyisocyanate composition as claimed in claim 1 , wherein the at least one polyisocyanate based on pentamethylene diisocyanate is mixed with the at least one polyisocyanate based on a cycloaliphatic diisocyanate or at least one polyisocyanate based on pentamethylene diisocyanate and at least one cycloaliphatic diisocyanate and one or more selected from the group consisting of auxiliaries and additives.

8 . A coating composition including the polyisocyanate as claimed in claim 1 as a crosslinking agent.

9 . In a process for increasing the chemical resistance of a coating, the improvement comprising including a pentamethylene diisocyanate in a polyisocyanate composition as claimed in claim 1 .

10 . A two-component system comprising:
component A) comprising at least one polyisocyanate composition as claimed in claim 1 ; and component B) comprising at least one binder reactive toward isocyanate groups, wherein at least one of component A) and/or component B) optionally further comprises at least one selected from the group consisting of flow control assistant and auxiliaries and additives.

11 . A process for producing a coating on a substrate, wherein the two-component system as claimed in claim 10 is applied to the substrate and is cured at a temperature >25° C.

12 . The coating produced by the process as claimed in claim 11 .

13 . A composite comprising the coating as claimed in claim 12 and a substrate having a surface selected from the group consisting of metal and plastic.

Assignees

• Covestro Intellectual Property Gmbh & Co Kg

Inventors

• Hecking Andreas
• Eggert Christoph
• Yuva Nusret
• Meyer Achim

Classifications

• C09D175/04

  Polyurethanes · CPC title

• C08G18/73 Primary

  acyclic · CPC title

• C08G18/6229 Primary

  Polymers of hydroxy groups containing esters of acrylic or methacrylic acid with aliphatic polyalcohols · CPC title

• C08G18/722 Primary

  Combination of two or more aliphatic and/or cycloaliphatic polyisocyanates · CPC title

• C08G18/792

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