Polyimide precursor, polyimide, flexible substrate prepared therewith, color filter and production method thereof, and flexible display device
The present invention is based on a polyimide precursor having unit structures represented by general formula (1) and unit structures represented by general formula (2), provides a polyimide precursor for which film whitening, cracking and bubbling do not occur regardless of film baking conditions, and provides a flexible TFT array, a flexible color filter, and a flexible substrate with a gas barrier layer using the polyimide precursor, and a flexible display device, etc. using same. (In general formulas (1) and (2), X 1 -X 4 each independently represents a hydrogen atom, C1 to C10 monovalent organic group or C1 to C10 monovalent alkylsilyl group. R 1 is represented by general formula (3) and R 2 is represented by general formula (4).) (In general formula (4), R 3 and R 4 each independently represents a C1 to C10 monovalent organic group.)
1. A polyimide precursor having a unit structure expressed by a general formula (1) and a unit structure expressed by a general formula (2):
wherein, in the general formulas (1) and (2), X 1 to X 4 each independently represent a hydrogen atom, a monovalent organic group with 1 to 10 carbon atoms or a monovalent alkylsilyl group with 1 to 10 carbon atoms, R 1 is represented by a general formula (3) and R 2 is represented by a general formula (4):
wherein, in the general formula (4), R 3 and R 4 each independently represent a monovalent organic group with 1 to 10 carbon atoms.
2. The polyimide precursor according to claim 1 , wherein a ratio of the unit structure expressed by a general formula (1) to the unit structure expressed by a general formula (2) [the number of moles of the unit structure expressed by a general formula (1)/the number of moles of the unit structure expressed by a general formula (2)] is 70/30 to 99.5/0.5.
3. A polyimide prepared from a polyimide precursor according to claim 1 .
4. A flexible substrate comprising a resin film containing a polyimide according to claim 3 .
5. A flexible substrate comprising an inorganic film disposed on a resin film containing a polyimide according to claim 3 .
6. A color filter comprising a black matrix and a colored pixel disposed on a resin film containing a polyimide according to claim 3 .
7. The color filter according to claim 6 , wherein a resin used for at least one layer of the black matrix and a colored pixel layer contains a polyimide resin.
8. The color filter according to claim 6 , wherein the black matrix is composed of a low optical density layer and a high optical density layer formed on the low optical density layer, and a resin used for at least one layer of the low optical density layer and the high optical density layer contains a polyimide resin.
9. The color filter according to claim 6 , further comprising an inorganic film.
10. A production method of a color filter, comprising a black matrix and a colored pixel disposed on a resin film containing a polymide prepared from a polymide precursor according to claim 1 comprising the following steps of:
(1) applying a resin composition containing a polyimide precursor according to claim 1 and a solvent on a support substrate;
(2) removing the solvent from the coated resin composition;
(3) obtaining a polyimide-containing resin film by imidizing the polyimide precursor in the resin composition;
(4) forming a black matrix and a colored pixel on the polyimide-containing resin film; and
(5) peeling off the polyimide-containing resin film from the support substrate.
11. The production method of a color filter according to claim 10 , further comprising the step of forming an inorganic film.
12. A flexible display device prepared by bonding a light-emitting element to a color filter according to claim 6 .
13. A flexible display device equipped with a light-emitting element disposed on a flexible substrate according to claim 4 .
14. The flexible display device according to claim 12 , wherein the light-emitting element is an organic EL element.