Liquid crystalline polyurethane elastomer and method for producing same

Patent metadata

Field	Value
Publication number	US-2016376396-A1
Application number	US-201415103005-A
Country	US
Kind code	A1
Filing date	Aug 22, 2014
Priority date	Dec 18, 2013
Publication date	Dec 29, 2016
Grant date	—

Abstract

A liquid crystalline polyurethane elastomer is produced by reacting an isocyanate component, a high-molecular-weight polyol component and a mesogenic diol represented by formula (1), and having a crosslinking site that is introduced by a tri-functional or higher isocyanate in the isocyanate component and/or a high-molecular-weight polyol having a number average molecular weight of 400 or more and less than 7000 and having three or more hydroxy groups, in the high-molecular-weight polyol component, wherein the melting point of a mesogenic unit does not exist in a temperature range lying between the glass transition temperature (Tg) and the (liquid crystal phase)-to-(isotropic phase) transition temperature (Ti) of the polyurethane elastomer, and a liquid crystal is developed at a temperature between the Tg and the Ti. (In the formula, X represents an alkylene group having 3 to 20 carbon atoms; and Y represents a single bond, —N═N—, —CO—, —CO—O— or —CH═N—.)

First claim

1 . A liquid crystalline polyurethane elastomer, which is produced by reacting at least an isocyanate component, a high-molecular-weight polyol component and a mesogenic diol represented by general formula (1) with one another, and has a crosslinking site that is introduced by a tri-functional or higher isocyanate in the isocyanate component and/or a high-molecular-weight polyol having a number average molecular weight of 400 or more and less than 7000 and having three or more hydroxy groups, in the high-molecular-weight polyol component, wherein the melting point of a mesogenic unit does not exist in a temperature range lying between the glass transition temperature (Tg) and the (liquid crystal phase)-to-(isotropic phase) transition temperature (Ti) of the polyurethane elastomer, and a liquid crystal is developed at a temperature between the Tg and the Ti.

(In the formula, X represents an alkylene group having 3 to 20 carbon atoms; and Y represents a single bond, —N═N—, —CO—, —CO—O— or —CH═N—.)

2 . The liquid crystalline polyurethane elastomer according to claim 1 , wherein the mesogenic diol when Y represents a single bond, —N═N— or —CO— is used; the glass transition temperature (Tg) is −50 to 30° C.; and the (liquid crystal phase)-to-(isotropic phase)transition temperature (Ti) is 35 to 85° C.

3 . The liquid crystalline polyurethane elastomer according to claim 1 , wherein the mesogenic diol when Y represents a single bond, —N═N— or —CO— is used; the blending amount of the mesogenic diol is 10 to 50 wt % based on the total material components; and the molecular weight between crosslinks is 1500 to 20000.

4 . The liquid crystalline polyurethane elastomer according to claim 1 , wherein the mesogenic diol when Y represents —CO—O— is used; the glass transition temperature (Tg) is −60° C. or higher and less than 30° C.; and the (liquid crystal phase)-to-(isotropic phase) transition temperature (Ti) is 30 to 130° C.

5 . The liquid crystalline polyurethane elastomer according to claim 1 , wherein the mesogenic diol when Y represents —CO—O— is used; the blending amount of the mesogenic diol is 30 to 80 wt % based on the total material components; and the molecular weight between crosslinks is 2500 to 25000.

6 . The liquid crystalline polyurethane elastomer according to claim 1 , wherein the mesogenic diol when Y represents —CH═N— is used; the glass transition temperature (Tg) is −50 to 30° C.; and the (liquid crystal phase)-to-(isotropic phase) transition temperature (Ti) is 35 to 120° C.

7 . The liquid crystalline polyurethane elastomer according to claim 1 , wherein the mesogenic diol when Y represents —CH═N— is used; the blending amount of the mesogenic diol is 15 to 70 wt % based on the total material components; and the molecular weight between crosslinks is 1500 to 25000.

8 . A method for producing a liquid crystalline polyurethane elastomer of claim 1 , which method comprises reacting at least an isocyanate component and a high-molecular-weight polyol component to synthesize an isocyanate-terminated prepolymer and reacting the resulting isocyanate-terminated prepolymer with a mesogenic diol.

9 . The liquid crystalline polyurethane elastomer according to claim 2 , wherein the mesogenic diol when Y represents a single bond, —N═N— or —CO— is used; the blending amount of the mesogenic diol is 10 to 50 wt % based on the total material components; and the molecular weight between crosslinks is 1500 to 20000.

10 . The liquid crystalline polyurethane elastomer according to claim 4 , wherein the mesogenic diol when Y represents —CO—O— is used; the blending amount of the mesogenic diol is 30 to 80 wt % based on the total material components; and the molecular weight between crosslinks is 2500 to 25000.

7 . The liquid crystalline polyurethane elastomer according to claim 6 , wherein the mesogenic diol when Y represents —CH═N— is used; the blending amount of the mesogenic diol is 15 to 70 wt % based on the total material components; and the molecular weight between crosslinks is 1500 to 25000.

Assignees

• Toyo Tire & Rubber Co

Inventors

• Hidaka Yuki

Classifications

• C08G18/4812

  Mixtures of polyetherdiols with polyetherpolyols having at least three hydroxy groups · CPC title

• C08G18/4829

  Polyethers containing at least three hydroxy groups (C08G18/4833 - C08G18/5096 take precedence) · CPC title

• C08G18/3215

  containing aromatic groups or benzoquinone groups · CPC title

• C08G18/10 Primary

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

• C08G18/3206

  aliphatic · CPC title