Polyimide and polyimide film comprising the same

Patent metadata

Field	Value
Publication number	US-9982103-B2
Application number	US-201314411151-A
Country	US
Kind code	B2
Filing date	Jun 27, 2013
Priority date	Jun 29, 2012
Publication date	May 29, 2018
Grant date	May 29, 2018

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.

First claim

The invention claimed is:

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 .

Assignees

• Kolon Inc

Inventors

• Ju Chul Ha
• Park Hyo Jun
• Jung Hak Gee

Classifications

• C08J5/18 Primary

  Manufacture of films or sheets · CPC title

• C08G73/10 Primary

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

• C08J2379/08

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

• C08K3/36

  Silica · CPC title

• C08L79/08

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