Polyimide and polyimide film comprising the same

• US 9,982,103 B2
• Filed: 06/27/2013
• Issued: 05/29/2018
• Est. Priority Date: 06/29/2012
• Status: Active Grant

• Current Assignee: Kolon Industries Incorporated
• Original Assignee: Kolon Industries Incorporated
• Inventors: Ju, Chul Ha, Park, Hyo Jun, Jung, Hak Gee
• Primary Examiner(s): Choi, Ling Siu
• Assistant Examiner(s): Nguyen, Thuy-Ai N
• Application Number:
  US14/411,151
• Publication Number:
  US 20150152232A1
• Time in Patent Office: 1,797 Days
• CPC Class Codes: C08G 73/1003 Preparatory processes
• CPC Class Codes: C08J 2379/08 Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
• CPC Class Codes: C08J 5/18 Manufacture of films or sheets
• CPC Class Codes: C08K 3/36 Silica
• CPC Class Codes: C09D 179/08 Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors

Abstract

This invention relates to polyimide, which includes amorphous silica particles having OH groups thereon and is thus highly heat-resistant, colorless and transparent, and to a polyimide film manufactured using the polyimide.

Claims

1. A polyimide, comprising amorphous silica particles having OH groups thereon,

wherein an amount of the amorphous silica particles is 0.01-0.1 parts by weight based on 100 parts by weight of the polyimide;

and

wherein the polyimide is obtained by (a) providing a partially imidized polyimide resin solid;

(b) mixing a dispersion of the amorphous silica and the partially imidized polyimide resin solid; and

(c) subjecting the resulting mixture obtained in (b) to imidization, wherein the dispersion of the amorphous silica contains the amorphous silica in a concentration of 0.01-1.0 wt % in a solvent.

2. The polyimide of claim 1, wherein the partially imidized polyimide resin solid is prepared by copolymerizing a dianhydride, an aromatic dicarbonyl compound and a diamine.

3. A polyimide film, comprising the polyimide of claim 1, wherein the polyimide film has on optical transmittance of 88% or more at a wavelength of 550 nm.

4. The polyimide film of claim 3, which has a haze of 2.0 or less.

5. The polyimide film of claim 3, which has a coefficient of thermal expansion of 15 ppm/°

C. or less at 50-250°

C., and a yellow index of 7 or less.

6. The polyimide film of claim 3, wherein the polyimide film is obtained by polymerizing a dianhydride, an aromatic dicarbonyl compound and a diamine in a first solvent to prepare a polyamic acid solution, imidizing the polyamic acid solution to prepare an imidized solution, which is then added to a second solvent, filtered and dried to obtain a polyimide resin solid, mixing the polyimide resin solid with amorphous silica particles having OH groups thereon dispersed in the first solvent to prepare a mixture, and then subjecting the mixture to a film forming process.

7. The polyimide film of claim 6, wherein the polyimide film is obtained by performing additional thermal treatment at 300-500°

C. for 1 min-3 hr, after the film forming process.

8. The polyimide film of claim 6, wherein the first solvent is at least one selected from the group consisting of m-cresol, N-methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide, acetone and diethylacetate, and the second solvent is at least one selected from among water, alcohols, ethers and ketones.

9. A substrate for a display, comprising the polyimide film of claim 3.