Polyurethane

Patent metadata

Field	Value
Publication number	US-9701780-B2
Application number	US-201615052343-A
Country	US
Kind code	B2
Filing date	Feb 24, 2016
Priority date	May 30, 2012
Publication date	Jul 11, 2017
Grant date	Jul 11, 2017

Abstract

A polybutadiene having a hydroxyl group at a terminal end thereof is reacted with a lactone compound such as an ε-caprolactone to obtain a polymer polyol represented by formula (I): HO—X 1 —Y—X 2 —OH (wherein X 1 and X 2 each independently represents a polyester component and Y represents a polybutadiene component), the polymer polyol is reacted with an unsymmetric diisocyanate to obtain a urethane prepolymer, and then the urethane prepolymer is reacted with a chain extender to obtain a polyurethane.

First claim

The invention claimed is:

1. A method for preparing a polyurethane, comprising:
reacting a polybutadiene having a hydroxyl group at a terminal end thereof with an ε-caprolactone to obtain a polymer polyol of formula (I);
reacting the polymer polyol and an unsymmetric diisocyanate to obtain a urethane prepolymer having an isocyanate group at a terminal end thereof, wherein an amount of the unsymmetric diisocyanate is determined so that a molar ratio of a mole number of isocyanate groups derived from the unsymmetric diisocyanate to a mole number of hydroxyl groups derived from the polymer polyol is within a range of 2.1 to 3.8; and then
reacting a chain extender with the urethane prepolymer to obtain the polyurethane, wherein an amount of the chain extender is determined so that a molar ratio of the mole number of the isocyanate groups derived from the unsymmetric diisocyanate with reference to a total mole number of hvdroxyl groups derived from the polymer polyol and the chain extender is within a range of 0.9 to 1.1,
HO—X 1 —Y—X 2 —OH  (I)

wherein:
X 1 and X 2 each independently represents a polyester component, and
Y represents a polybutadiene component consisting of:
a 1,4-structure consisting of a repeating unit represented by formula (IVb); and
a 1,2-structure consisting of a repeating unit represented by formula (Vb):

wherein a molar ratio of the 1,2-structure/the 1,4-structure is within a range from 90.4/9.6 to 95/5.

2. The method according to claim 1 , wherein the chain extender is an aliphatic glycol.

Assignees

• Nippon Soda Co

Inventors

• Shirai Akihiro
• Miyashita Yasunori
• Kimizuka Shinichi
• Nakamura Mitsuhiro

Classifications

• C08G18/10

  Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step · CPC title

• C08G18/694

  containing carboxylic ester groups · CPC title

• C08G18/4275

  Valcrolactone and/or substituted valcrolactone · CPC title

• C08G18/69

  Polymers of conjugated dienes {(hydrogenated polymers of conjugated dienes C08G18/6208)} · CPC title

• C08G18/3206

  aliphatic · CPC title