Polyamide acid, polyimide, optical film, display device and production methods thereof

Patent metadata

Field	Value
Publication number	US-12351685-B2
Application number	US-202017428860-A
Country	US
Kind code	B2
Filing date	Feb 3, 2020
Priority date	Feb 6, 2019
Publication date	Jul 8, 2025
Grant date	Jul 8, 2025

Abstract

A polyimide which is obtained by a reaction of an aromatic diamine having a 1,1,1-trifluoro-2,2-ethanediyl group (—C(CF 3 )H—), as a linkage skeleton, with a tetracarboxylic dianhydride is easily dissolved in an organic solvent and exhibits excellent film forming properties. In addition, the thus-obtained polyimide can be used for an optical film and a display device.

First claim

The invention claimed is:

1. A polyimide having a repeating unit represented by General Formula [1], with the proviso that a polyimide having a repeating unit represented by General Formula [3] is excluded:

wherein, in General Formula [1], R 1 is a divalent organic group represented by General Formula [2], and R 2 is a tetravalent organic group, and

wherein, in General Formula [2], n is an integer of 1 to 4, and R 3 each independently represents an alkyl group.

2. The polyimide according to claim 1 , wherein R 1 is at least one divalent organic group selected from the following:

3. The polyimide according to claim 1 , wherein R 2 is at least one tetravalent organic group selected from the following:

4. The polyimide according to claim 1 , wherein a weight average molecular weight is equal to or more than 1,000 and equal to or less than 1,000,000.

5. A polyamide acid having a repeating unit represented by General Formula [1A], with the proviso that a polyamide acid having a repeating unit represented by General Formula [3A] is excluded:

wherein, in General Formula [1A], R 1 is a divalent organic group represented by General Formula [2], and R 2 is a tetravalent organic group, and

wherein, in General Formula [2], n is an integer of 1 to 4, and R 3 each independently represents an alkyl group.

6. The polyamide acid according to claim 5 , wherein R 1 is at least one divalent organic group selected from the following:

7. The polyamide acid according to claim 5 , wherein R 2 is at least one tetravalent organic group selected from the following:

8. The polyamide acid according to claim 5 , wherein a weight average molecular weight is equal to or more than 1,000 and equal to or less than 1,000,000.

9. A polyimide solution comprising:
the polyimide according to claim 1 ; and
an organic solvent.

10. The polyimide solution according to claim 9 , wherein the organic solvent is at least one selected from the group consisting of an amide-based solvent, an ether-based solvent, an aromatic hydrocarbon-based solvent, a halogen-based solvent, and a lactone-based solvent.

11. The polyimide solution according to claim 9 , wherein the polyimide is in an amount of equal to or more than 0.1% by mass and equal to or less than 50% by mass with respect to an entire polyimide solution.

12. A polyamide acid solution comprising:
the polyamide acid according to claim 5 ; and
an organic solvent.

13. The polyamide acid solution according to claim 12 , wherein the organic solvent is at least one selected from the group consisting of an amide-based solvent, an ether-based solvent, an aromatic hydrocarbon-based solvent, a halogen-based solvent, and a lactone-based solvent.

14. The polyamide acid solution according to claim 12 , wherein the polyamide acid is in an amount of equal to or more than 0.1% by mass and equal to or less than 50% by mass with respect to an entire polyamide acid solution.

15. An optical film comprising:
the polyimide according to claim 1 .

16. An optical film comprising:
the polyamide acid according to claim 5 .

17. An optical film comprising:
the polyimide according to claim 1 ; and
the polyamide acid according to claim 5 .

18. A display device comprising:
the optical film according to claim 15 .

19. A method for producing a polyimide according to claim 1 , the method comprising:
a step of polycondensing a diamine represented by General Formula [2A]:

wherein, in General Formula [2A], R 3 each independently represents an alkyl group, and n is an integer of 1 to 4,
with a tetracarboxylic dianhydride represented by General Formula [4]:

wherein, in General Formula [4], R 2 is a tetravalent organic group to obtain the polyimide having a repeating unit represented by General Formula [1].

20. The method for producing a polyimide according to claim 19 , wherein the step of polycondensing the diamine represented by General Formula [2A] with the tetracarboxylic dianhydride represented by General Formula [4] to obtain the polyimide having a repeating unit represented by General Formula [1] includes:
a step of reacting the diamine represented by General Formula [2A] with the tetracarboxylic dianhydride represented by General Formula [4] to obtain a polyamide acid having a repeating unit represented by General Formula [1A], with the proviso that a polyamide acid having a repeating unit represented by General Formula [3A] is excluded:

wherein, in General Formula [1A], R 1 has the same definition as R 1 in General Formula [1], and R 2 has the same definition as R 2 in General Formula [1]; and
a step of dehydrating and ring-closing the polyamide acid represented by General Formula [1A] to be converted into the polyimide represented by General Formula [1].

21. A method for producing an optical film or a display device, comprising:
a step of applying the polyimide solution according to claim 9 or the polyamide acid solution according to claim 12 to a supporting base material;
a step of removing a solvent contained in the polyimide solution or the polyamide acid solution, followed by drying to produce a resin film containing polyimide or polyamide acid; and
a step of heat-treating and curing the resin film.

22. The method for producing an optical film or a display device according to claim 21 , wherein the supporting base material is at least one selected from the group consisting of glass, silicon wafer, stainless steel, alumina, copper, nickel, polyethylene terephthalate, polyethylene glycol terephthalate, polyethylene glycol naphthalate, polycarbonate, polyimide, polyamide imide, polyether imide, polyether ether ketone, polypropylene, polyether sulfone, polyphenylene sulfone, and polyphenylene sulfide.

23. The method for producing an optical film or a display device according to claim 21 , wherein the step of applying the polyimide solution or the polyamide acid solution to the supporting base material includes a step of applying the solution such that a film thickness is equal to or more than 1 μm and equal to or less than 1,000 μm.

24. The method for producing an optical film or a display device according to claim 21 , wherein the step of drying is carried out at a temperature of equal to or higher than 50° C. and equal

Assignees

• Central Glass Co Ltd

Inventors

• Eguchi Hiroshi
• Yamaguchi Ayumi
• Hara Yukari
• Matsunaga Kei
• Hori Hiroto
• Murakami Yosuke
• Hirotaki Kensuke
• Hosoi Kenji

Classifications

• C08G73/1028

  characterised by the process itself, e.g. steps, continuous · CPC title

• C08G73/123

  the unsaturated precursors comprising halogen-containing substituents · CPC title

• C08G73/1078

  wholly aromatic in the diamino moiety · CPC title

• C07C215/80

  containing at least two amino groups bound to the carbon skeleton · CPC title

• C07C213/08

  by reactions not involving the formation of amino groups, hydroxy groups or etherified or esterified hydroxy groups · CPC title