Polyimide film forming composition and polyimide film produced by using same

Patent metadata

Field	Value
Publication number	US-11261304-B2
Application number	US-201716345523-A
Country	US
Kind code	B2
Filing date	Oct 27, 2017
Priority date	Oct 31, 2016
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

The present invention provides a polyimide film forming composition which comprises a polyamic acid or a polyimide in an oligomer form or in a low-molecular weight form, the polyamic acid or the polyimide being prepared from a diamine containing an intramolecular imide group, and thus can provide a polyimide film having improved heat resistance while retaining optical properties thereof. In addition, the polyimide film according to the present invention can reduce not only a laser energy density (E/D) required in the laser exfoliation process but also remarkably decrease an amount of ash generated by an exfoliation process, thereby further improving the reliability of a device in a display manufacturing process.

First claim

The invention claimed is:

1. A composition for forming a polyimide film which comprises:
a first polyimide including a repeating unit of the following Chemical Formula 1-1 or a first polyamic acid including a repeating unit of the following Chemical Formula 1-2; and
a second polyamic acid having a weight average molecular weight of 50,000 g/mol or more,
wherein the first polyimide or the first polyamic acid has a weight average molecular weight of 500 g/mol to 40,000 g/mol:

wherein,
R 1 and R 2 are each independently hydrogen atom or a substituent selected from a halogen atom, a hydroxyl group (—OH), a thiol group (—SH), a nitro group (—NO 2 ), a cyano group (—CN), a C 1-10 alkyl group, a C 1-4 halogenoalkoxyl group, a C 1-10 halogenoalkyl group, and a C 6-20 aryl group.

2. The composition for forming a polyimide film according to claim 1 , wherein the second polyamic acid includes repeating units of the following Chemical Formula 2 and Chemical Formula 3:

wherein,
R 3 and R 4 are each independently hydrogen atom or a substituent selected from a halogen atom, a hydroxyl group (—OH), a thiol group (—SH), a nitro group (—NO 2 ), a cyano group (—CN), a C 1-10 alkyl group, a C 1-4 halogenoalkoxyl group, a C 1-10 halogenoalkyl group, and a C 6-20 aryl group.

3. The composition for forming a polyimide film according to claim 2 , wherein the amount of the repeating unit of Chemical Formula 1-1 or Chemical Formula 1-2 is from 3 mol % to 50 mol % based on the total repeating units of the first polyimide or the first polyamic acid and the total repeating units of the second polyamic acid.

4. The composition for forming a polyimide film according to claim 1 , wherein the first polyimide or the first polyamic acid includes a terminal group including a structure of the following Chemical Formula 4:

wherein,
R 11 is a C 1-10 alkylene group, and
R 12 , R 13 and R 14 are each independently selected from a C 1-10 alkoxyl group, a C 6-30 aryloxy group and a heterocyclic group containing 1 to 3 oxygen atoms.

5. A polyimide film comprising a heat-cured composition of claim 1 .

6. A polyimide film according to claim 5 , which shows coefficient of thermal expansion (CTE) of 0 ppm/° C. to 20 ppm/° C. at a heating process after repeating n+1 times (n is an integer equal to or greater than 0) heating and cooling process in a temperature range of from 100° C. to 300° C.

7. The polyimide film according to claim 5 , wherein a yellow index (YI) of the film is 15 or less at a thickness of 8 μm to 15 μm, and a haze of the film is 2 or less.

Assignees

• Lg Chemical Ltd

Inventors

• Shin Bo Ra
• Yun Cheolmin
• Jeong Hye Won
• Kim Kyungjun

Classifications

• C08G73/10 Primary

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

• C08J5/18 Primary

  Manufacture of films or sheets · CPC title

• C08L2205/02

  containing two or more polymers of the same C08L -group · CPC title

• C08G73/14 Primary

  Polyamide-imides · CPC title

• C08L79/08

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