Method for preparing polyisocyanate composition

Patent metadata

Field	Value
Publication number	US-12565572-B2
Application number	US-202017637147-A
Country	US
Kind code	B2
Filing date	Aug 20, 2020
Priority date	Aug 23, 2019
Publication date	Mar 3, 2026
Grant date	Mar 3, 2026

Abstract

There is provided a method for preparing a polyisocyanate composition capable of improving transparency of a product, by mixing a phenol-based stabilizer in an amount of 1 to 1000 ppmw, based on the total weight of aromatic diisocynate, and then, introducing polyhydric alcohol to conduct a polymerization reaction, thereby inhibiting coloration and whitening due to oxygen or moisture during synthesis and purification processes.

First claim

The invention claimed is:

1 . A method for preparing a polyisocyanate composition comprising the steps of:
mixing aromatic diisocyanate and a phenol-based stabilizer to prepare a monomer composition; and adding polyhydric alcohol having two or more hydroxyl groups in the molecule to the monomer composition and conducting a polymerization reaction, wherein a mole ratio of hydroxyl groups in the polyhydric alcohol to isocyanate groups in the aromatic diisocyanate is 0.1 to less than 1, based on 1 mole of isocyanate group in the aromatic diisocyanate, and wherein the phenol-based stabilizer comprises a mixture of phenol and dibutylhydroxytoluene at a weight ratio of 10:1 to 5:3 and is used in an amount of 600 to 1000 ppmw, based on the total weight of the aromatic diisocyanate.

2 . The method for preparing a polyisocyanate composition according to claim 1 , wherein the aromatic diisocyanate comprises xylylene diisocyanate, diphenylmethane diisocyanate, bis (isocyanatophenyl) propane, diisocyanate anisole or a mixture thereof.

3 . The method for preparing a polyisocyanate composition according to claim 1 , wherein the polyhydric alcohol comprises trihydric alcohol; or a mixture of trihydric alcohol and polyhydric alcohol other than trihydric alcohol.

4 . The method for preparing a polyisocyanate composition according to claim 1 , wherein the polyhydric alcohol comprises diethylene glycol, glycerol, trimethylolethane, trimethylolpropane or a mixture thereof.

5 . The method for preparing a polyisocyanate composition according to claim 1 , wherein the polymerization reaction is conducted at 40 to 100° C. under inert gas atmosphere.

6 . The method for preparing a polyisocyanate composition according to claim 1 , further comprising a step of purifying the product of the polymerization reaction, after the polymerization reaction.

7 . The method for preparing a polyisocyanate composition according to claim 6 , wherein the purification is conducted by thin film evaporation.

Assignees

• Hanwha Solutions Corp

Inventors

• Sim Yujin
• Park Juyoung
• Lee Byeong Hyeon
• Cho Sanghyun

Classifications

• C08G18/7642

  containing at least two isocyanate or isothiocyanate groups linked to the aromatic ring by means of an aliphatic group having a primary carbon atom next to the isocyanate or isothiocyanate groups, e.g. xylylene diisocyanate or homologues substituted on the aromatic ring · CPC title

• C08G18/3206

  aliphatic · CPC title

• C08G18/089 Primary

  Reaction retarding agents · CPC title

• C08K5/13 Primary

  Phenols; Phenolates · CPC title

• C08K5/005

  Stabilisers against oxidation, heat, light, ozone · CPC title