Composition for forming thin resin film, and thin resin film

Abstract

A composition for forming thin resin films, characterized by comprising the following ingredients (A), (B), and (C). Ingredient (A): a polyamic acid which has a weight-average molecular weight of 5,000 or higher and comprises a monomer unit represented by formula (1-1) and a monomer unit represented by formula (1-2) [Chemical formula 1] (in the formulae, X1 represents a benzene-1,2,4,5-tetrayl group, Y1 represents a p-phenylene group, and Y2 represents a p-terphenyl-4,4'''-diyl group). Ingredient (B): one polyamic acid selected from between a polyamic acid which has a weight-average molecular weight of 5,000 or higher and comprises a monomer unit represented by formula (1-1), a monomer unit represented by formula (1-2), and a monomer unit represented by formula (1-3) and a polyamic acid which has a weight-average molecular weight of 5,000 or higher and comprises a monomer unit represented by formula (1-1), a monomer unit represented by formula (1-2), and a monomer unit represented by formula (1-4) [Chemical formula 2] [in the formulae, X1, Y1, and Y2 have the same meanings as above, Y3 represents a divalent group represented by formula (2) [Chemical formula 3] -R1-L-R2- (2) (in formula (2), L represents -O-, -S-, -CO-, or -SO-, and R1 and R2 each independently represent a divalent organic group) and X2 represents a tetravalent group that includes a C6-25 aromatic group and is selected from among formulae (3-1), (3-2), (3-3), and (3-4) [Chemical formula 4] (in the formulae, O represents a linking bond and L has the same meaning as above)]. Ingredient (C): a solvent.

Description

technical field [0001] The present invention relates to a composition for forming a resin film and a resin film. Background technique [0002] In recent years, in the fields of display devices such as organic electroluminescent displays and liquid crystal displays, there have been increasing demands for weight reduction, flexibility, and the like in addition to high definition. Under such circumstances, it is known that polyimide resin which is easy to manufacture and has high heat resistance is attracting attention as a display substrate material instead of glass. [0003] However, to use polyimide as a display substrate material, as described later, a value close to the linear expansion coefficient of glass (about 3 to 8 ppm / K) is required, but most polyimides have a value of 60 to 80 ppm / K. The coefficient of linear expansion is about 80ppm / K, so it is not suitable for display substrate materials. [0004] That is, a high-definition display uses an active matrix drive p...

AI Technical Summary

Problems solved by technology

[0006] As a polyimide exhibiting a low coefficient of linear expansion, a polyimide derived from tetracarboxylic dianhydride and a diamine having high rigidity has been proposed, but in the high-temperature region (300 to 300 ∼ 500°C) becomes a high linear expansion coefficient; when the rigidity of the polymer skeleton is too high, there are many problems such as damage to the strength and flexibility of the film (Patent Document 1, Non-Patent Document 1), which fully meet the high requirements polymer is still unknown

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