Transparent polyimide and precursor thereof

Patent metadata

Field	Value
Publication number	US-9850346-B2
Application number	US-201414889393-A
Country	US
Kind code	B2
Filing date	May 9, 2014
Priority date	May 14, 2013
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

Provided is a polyimide excellent in heat resistance and colorless transparency and also excellent in flexibility and ultraviolet ray transmittance. The polyimide includes a structural unit represented by Formula (1a) and a structural unit represented by Formula (1b) wherein R is a specific aromatic group.

First claim

The invention claimed is:

1. A polyimide comprising a structural unit represented by Formula (1a) and a structural unit represented by Formula (1b),

wherein in Formulae (1a) and (1b), R is a group represented by Formula (x1), (x2) or (x3),

wherein in Formulae (x1), (x2) and (x3), * is a carbon atom bonding to a carbon atom of C═O adjacent to R, and when plural Rs are contained, those groups may be the same or different from each other,
m is a molar ratio of the structural unit represented by Formula (1a) relative to the total of the structural unit represented by Formula (1a) and the structural unit represented by Formula (1b), n is a molar ratio of the structural unit represented by Formula (1b) relative to the total of the structural unit represented by Formula (1a) and the structural unit represented by Formula (1b) (m+n=100%) wherein m/n ranges from 99.9/0.1 to 50.0/50.0, the structural unit represented by Formula (1a) and the structural unit represented by Formula (1b) are bonded to each other, and the bonding form is random,
a cyclohexane skeleton (y) in Formula (1a) comprises 60% to 100% of a trans isomer represented by Formula (y1) and 40% to 0% of a cis isomer represented by Formula (y2) wherein the trans isomer and the cis isomer total 100%, and

a 1,4-bismethylenecyclohexane skeleton (z) in Formula (1b) comprises 60% to 100% of a trans isomer represented by Formula (z1) and 40% to 0% of a cis isomer represented by Formula (z2) wherein the trans isomer and the cis isomer total 100%

2. The polyimide according to claim 1 , wherein in Formulae (1a) and (1b), R is a group represented by Formula (x1).

3. A polyamic acid comprising a structural unit represented by Formula (2a) and a structural unit represented by Formula (2b),

wherein in Formula (2a) and (2b), R is a group represented by Formula (x1), (x2) or (x3),

wherein in Formulae (x1), (x2) and (x3), * is a carbon atom bonding to a carbon atom of C═O adjacent to R, and when plural Rs are contained, those groups may be the same or different from each other,
m is a molar ratio of the structural unit represented by Formula (2a) relative to the total of the structural unit represented by Formula (2a) and the structural unit represented by Formula (2b), n is a molar ratio of the structural unit represented by Formula (2b) relative to the total of the structural unit represented by Formula (2a) and the structural unit represented by Formula (2b) wherein m/n ranges from 99.9/0.1 to 50.0/50.0, the structural unit represented by Formula (2a) and the structural unit represented by Formula (2b) are bonded to each other, and the bonding form is random,
a cyclohexane skeleton (y) in Formula (2a) comprises 60% to 100% of a trans isomer represented by Formula (y1) and 40% to 0% of a cis isomer represented by Formula (y2) wherein the trans isomer and the cis isomer total 100%, and

a 1,4-bismethylenecyclohexane skeleton (z) in Formula (2b) comprises 60% to 100% of a trans isomer represented by Formula (z1) and 40% to 0% of a cis isomer represented by Formula (z2) wherein the trans isomer and the cis isomer total 100%

4. The polyamic acid according to claim 3 , wherein in the Formulae (2a) and (2b), R is a group represented by Formula (x1).

5. A polyimide composition comprising the polyimide according to claim 1 and an inorganic filler.

6. A polyamic acid composition comprising the polyamic acid according to claim 3 and an inorganic filler.

7. A process for producing the polyamic acid according to claim 3 , comprising a step of allowing a diamine mixture containing 1,4-cyclohexanediamine and 1,4-bis(aminomethyl)cyclohexane such that a molar ratio of 1,4-cyclohexanediamine/1,4-bis(aminomethyl)cyclohexane ranges from 99.9/0.1 to 50.0/50.0 to react with a tetracarboxylic dianhydride containing at least one selected from bis(3,4-dicarboxyphenyl)ether dianhydride, 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride and 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride.

8. A process for producing the polyimide according to claim 1 , comprising:
a step of allowing 1,4-cyclohexanediamine to react with a tetracarboxylic dianhydride containing at least one selected from bis(3,4-dicarboxyphenyl)ether dianhydride, 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride and 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, to produce a polyamic acid (1) containing a structural unit represented by Formula (3a);
a step of allowing 1,4-bis(aminomethyl)cyclohexane to react with a tetracarboxylic dianhydride containing at least one selected from bis(3,4-dicarboxyphenyl)ether dianhydride, 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride and 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, to produce a polyamic acid (2) containing a structural unit represented by Formula (3b);
a step of mixing the polyamic acid (1) with the polyamic acid (2) such that a molar ratio of the structural unit represented by Formula (3a)/the structural unit represented by Formula (3b) ranges from 99.9/0.1 to 50.0/50.0, to produce a polyamic acid mixture, and
a step of imidizing the polyamic acid mixture,

wherein in Formulae (3a) and (3b), R is a group represented by Formula (x1), (x2) or (x3),

wherein in Formulae (x1), (x2) and (x3), * is a carbon atom bonding to a carbon atom of C═O adjacent to R, and when plural Rs are contained in the polymer, those groups may be the same or different from each other.

9. A polyamic acid varnish comprising the polyamic acid according to claim 3 and a solvent.

10. A dry film comprising the polyamic acid according to claim 3 .

11. A film comprising the polyimide according to claim 1 .

12. An optical film comprising the film according to claim 11 .

13. A substrate for a flexible display, comprising the optical film according to claim 12 .

Assignees

• Mitsui Chemicals Inc

Inventors

• Fukukawa Kenichi
• Okazaki Masaki
• Sakata Yoshihiro
• Urakami Tatsuhiro
• Okubo Atsushi

Classifications

• C08G73/1064

  containing sulfur · CPC title

• C09D177/06

  Polyamides derived from polyamines and polycarboxylic acids (C09D177/10 takes precedence) · CPC title

• C08J2379/08

  Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors · CPC title

• C08K3/013

  Fillers, pigments or reinforcing additives · CPC title

• C08G69/48

  Polymers modified by chemical after-treatment · CPC title