Disclosed therein are a photoalignment polyimide copolymer making it easier to form a liquid crystal alignment layer with excellences in alignment properties, thermal and structural stabilities, and adhesiveness to a substrate, and a liquid crystal alignment layer using the same. The photoalignment polyimide copolymer includes all the three types of repeating units each having a defined structure.

A polyamic acid useful for forming a protective or insulative layer for semiconductor elements has a structure represented by chemical formula (1): ##STR00001##
wherein δ represents an oxygen or sulfur atom; W represents an electron-withdrawing group; and R.sup.11 and R.sup.12 represent independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.

A polyimide resin containing a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2), a content ratio of the repeating structural unit of formula (1) with respect to the total of the repeating structural unit of formula (1) and the repeating structural unit of formula (2) being 20 to 70 mol %, and the polyimide resin having a chain aliphatic group having from 5 to 14 carbon atoms at an end thereof:

wherein R.sub.1 represents a divalent group having from 6 to 22 carbon atoms containing at least one alicyclic hydrocarbon structure; R.sub.2 represents a divalent chain aliphatic group having from 5 to 16 carbon atoms; and X.sub.1 and X.sub.2 each independently represent a tetravalent group having from 6 to 22 carbon atoms containing at least one aromatic ring.

To provide a polymer material having properties that allow the polymer material to replace a polyimide and a polyamide synthesized from a petroleum raw material, said polymer material being synthesized from a raw material derived from natural molecules. [Solution] This polymer material is obtained by polymerizing a polymer raw material comprising a dimer of 4-amino cinnamic acid or a dimer of a 4-amino cinnamic acid derivative, which are natural molecules, wherein the carboxyl group is protected by an alkyl chain. The TGA curve of a polyamide acid (PAA-1) and a polyimide (PI-1) according to the present invention is shown in FIG. 5.

Provided are a solid electrolyte composition containing an inorganic solid electrolyte (A) having a conductivity of an ion of a metal belonging to Group I or II of the periodic table and a binder (B), in which the binder (B) is a polymer having at least one bond of a urethane bond, a urea bond, an amide bond, an imide bond, or an ester bond in a main chain and having a graft structure, a solid electrolyte-containing sheet and a manufacturing method therefor, an all-solid state secondary battery and a manufacturing method therefor, and a polymer having a specific hard segment and a graft structure and a non-aqueous solvent dispersion thereof.

A polyimide precursor film contains a polyimide precursor, in which a total content of a solvent containing water and a solvent other than water in the polyimide precursor film is 5 mass % or more and 40 mass % or less, and a mass ratio of water to the solvent other than water in the polyimide precursor film is 0 or more and 2.5 or less.

The present invention discloses a novel diamine that has a structure bearing an intramolecular imide group and additionally an amide-substituted aromatic ring group at opposite sides of the imide group. The use of the novel diamine as a polymerization ingredient in polyimide production can provide a polyimide film which has remarkably improved mechanical and thermal properties while maintaining optical properties.

A polyimide precursor solution contains: an aqueous solvent containing water; particles; and a polyimide precursor, wherein the polyimide precursor has a high molecular weight region A containing a high molecular weight side maximum value and a low molecular weight region B containing a low molecular weight side maximum value in an elution curve obtained by gel permeation chromatography, a weight average molecular weight in the high molecular weight region A is 50,000 or more, a weight average molecular weight in the low molecular weight region B is 10,000 or more and 30,000 or less, and a value of a/(a+b) is 0.60 or more and 0.98 or less in which a represents an area of the high molecular weight region A and b represents an area of the low molecular weight region B.

An insulating coating material including a polyimide film, and an adhesion layer on at least one side of a polyimide film. The polyimide film has a weight of 23.5 g or less per 1 m.sup.2 and a loop stiffness value of 0.45 g/cm or more

Disclosed is a novel diamine compound in which an imide ring is directly bonded to a (hetero)aryl ring in a molecule, and a polyimide film prepared by polymerizing the novel diamine compound exhibits improved thermal properties and storage stability.