Method for producing TDI-trimerisates with high purity

Patent metadata

Field	Value
Publication number	US-10676448-B2
Application number	US-201816150728-A
Country	US
Kind code	B2
Filing date	Oct 3, 2018
Priority date	Mar 12, 2013
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

The invention relates to a novel method for producing polyisocyanurates comprising isocyanate groups, based on 2,4- and 2,6-toluylene diisocyanate (TDI) and to the use thereof in coating compositions.

First claim

The invention claimed is:

1. A method for producing polyisocyanates comprising solvent and/or diluent and isocyanurate groups, based on 2,4-toluylene diisocyanate, having a content of monomeric diisocyanate of <0.5 wt. %, based on polyisocyanate plus solvent, comprising trimerising
A) from 20 to 80 wt. % of 2,4-toluylene diisocyanate in the presence of
B) from 20 to 80 wt. % of solvents and/or diluents, and
C) a phenolic catalyst comprising dialkylaminomethyl groups
at a temperature of from 40 to 120° C. to almost complete conversion, and then deactivating the catalyst by addition of an acid-reacting substance or by reaction with an alkylating agent, wherein the toluylene diisocyanate has a content of 2-chloro-6-isocyanato-methylcyclohexadienes (CIMCH) below the detection limit of 1 wt. ppm and wherein the polyisocyanates comprising solvent and/or diluent and isocyanurate groups have APHA colour indices <100 Hazen.

2. The method according to claim 1 , wherein the toluylene diisocyanate is produced by gas phase phosgenation.

3. The method according to claim 1 , wherein the catalyst is obtained as a Mannich base based on phenol or bisphenol A by reaction with dimethylamine and formaldehyde.

4. The method according to claim 1 , wherein the catalyst is deactivated by dibutyl phosphate or p-toluenesulfonic acid methyl ester.

5. The polyisocyanates produced by the method according to claim 1 comprising solvent and/or diluent and isocyanurate groups.

6. A method comprising utilizing the polyisocyanate produced according to the method of claim 5 as the polyisocyanate component in polyurethane coatings.

7. The method according to claim 6 wherein the polyisocyanates comprise a crosslinker in two-component polyurethane coatings.

8. A polyurethane adhesive comprising the polyisocyanates produced according to the method of claim 5 .

Assignees

• Covestro Deutschland Ag

Inventors

• Sanders Josef
• Hecking Andreas
• Halpaap Reinhard
• Richter Frank
• Wilmes Oswald
• Busch Jan
• Loddenkemper Tim
• Steffens Friedhelm
• Groth Stefan

Classifications

• C08G18/022

  the polymeric products containing isocyanurate groups · CPC title

• C09J175/06

  from polyesters · CPC title

• C07D251/30 Primary

  Only oxygen atoms · CPC title

• C09D175/06

  from polyesters · CPC title

• C08G18/092

  oligomerisation to isocyanurate groups · CPC title