Provided are a polyamic acid resin, a polyamideimide film, and a method for preparing the same. More specifically, provided are a polyamic acid resin derived from a combination of specific components, and a polyamideimide film capable of implementing high modulus and excellent optical properties.

Provided are a polyamic acid resin, a polyamideimide film, and a method for preparing the same. More specifically, provided are a polyamic acid resin derived from a combination of specific components, a polyamideimide film capable of implementing high modulus and excellent optical properties while implementing excellent mechanical properties, heat properties, and electrical properties, and a method for preparing the same.

The present invention relates to a polyimide powder and a preparation method therefor. With respect to the polyimide powder and the preparation method therefor, according to the present invention, a preparation process is simplified such that process efficiency can be improved, a polyimide is prepared in the form of a powder so as to facilitate molding thereof, and the polyimide has a low precipitation temperature and a high intrinsic viscosity so as to facilitate processing thereof, and has a uniform particle size so as to have excellent processability.

The present invention provides a polyimide film and a graphite sheet prepared therefrom, wherein the polyimide film is obtained by an imidication reaction of a polyamic acid comprising: quinoline and -picoline as imidication catalysts; and acetic anhydride as a dehydrating agent.

The present invention provides a polyamic acid aqueous solution composition capable of polymerizing polyamic acid in water rather than in an organic solvent, as well as achieving a high imidization rate during low-temperature curing.

A method for producing a polyimide precursor, including: reacting tetracarboxylic dianhydride represented by the following General Formula (1) with a diamine compound represented by the following General Formula (2) in a compressive fluid to thereby produce a polyimide precursor represented by the following Formula (3): ##STR00001## where, X in the General Formulae (1) and (3) denotes a tetravalent aromatic group or a tetravalent alicyclic group, Y in the General Formulae (2) and (3) denotes a divalent organic group, and n denotes the number of repetitions.

A polyimide precursor composition in which a resin and an organic amine compound are dispersed in an aqueous solvent, wherein the aqueous solvent contains 50% by weight or more of water and at least one organic solvent selected from a solvent group A consisting of a urea solvent, an amide solvent containing an alkoxy group, and an amide solvent containing an ester group in an amount of 5% by weight or more with respect to the total amount of the aqueous solvent, and the resin has a repeating unit represented by the following formula (I):

##STR00001##

wherein A indicates a tetravalent organic group, and B indicates a bivalent organic group.

An aqueous polyimide precursor solution composition in which a polyamic acid which is formed by the reaction of a tetracarboxylic acid component and a diamine component, and contains a repeating unit represented by the following formula (1), is dissolved in an aqueous solvent together with an imidazole in an amount of 1.6 mole or more per mole of the tetracarboxylic acid component of the polyamic acid, in which the aqueous polyimide precursor solution composition contains no organic solvent, and the polyamic acid has an inherent viscosity of 0.2 or more.

##STR00001##

The disclosure provides catalysts for synthesizing polyimides and preparation methods therefor, as well as polyimide compounds. The structural formula of the catalyst may be represented by formula (1):

##STR00001##

in formula (1), R.sub.3 is selected from O or NH; R.sub.4 is selected from O or NH; Ar.sup.2 is a substituted aryl group, and the substituent of the substituted aryl group comprises a carboxyl group; R.sub.5 is selected from a hydrogen atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, an ester group, an alkyl group, an alkoxy group or a haloalkyl group; and n is an integer ranging from 1 to 4.

A method for producing a resin composition is disclosed. The method for producing a resin composition includes: obtaining a polyimide resin by reacting a tetracarboxylic dianhydride with a polyamine in an organic solvent; and obtaining a resin composition containing a polymaleimide resin and the organic solvent by reacting the polyimide resin with maleic anhydride. The polyamine contains dimer diamine. The organic solvent contains 1,2,4-trimethylbenzene.