The purpose of the present invention is to provide: a film having high thermal stability, high bending strength (tensile elongation), small retardation in the thickness direction, a low coefficient of thermal expansion, and high transparency; and a polyamic acid or varnish for obtaining the film. The film satisfies all of requirements (i)-(vi) below. (i) The average value of the coefficient of thermal expansion in the range of 100-200° C. is 35 ppm/K or less. (ii) The absolute value of the retardation in the thickness direction is 200 nm or less per 10 μm of thickness. (iii) The glass transition temperature is 340° C. or higher. (iv) The total light transmittance is at least 85%. (v) The b* value in the L*a*b* color system is 5 or less. (vi) The tensile elongation is at least 10%.

A polyimide resin composition containing a polyimide resin (A) and a phosphinic acid metal salt-based flame retardant (B), the polyimide resin (A) containing repeating structural units of formulae (1) and (2):

##STR00001## 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, and 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) is 20 to 70 mol %.

This invention relates to a (meth)acrylate-functionalized poly(meth)acrylate-block-polyimide-block-poly(meth)acrylate copolymer, preparation method and use thereof. The (meth)acrylate-functionalized poly(meth)acrylate-block-polyimide-block-poly(meth)acrylate copolymer according to the present invention exhibits outstanding thermal stability and excellent optical properties.

A resin molded article having a microphase-separated structure, the resin molded article containing a polyimide resin (A) and a polyether ketone resin (B), the polyimide resin (A) containing repeating structural units of formulae (1) and (2):

##STR00001## 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, 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) is 20 to 70 mol %, and a weight average molecular weight Mw is 40,000 to 150,000.

The present disclosure provides a polyimide film having improved heat resistance and refractive index by using a polyimide precursor composition comprising a diamine of Chemical Formula 1 and an acid dianhydride of Chemical Formula 2 as polymerization components, thereby reducing the difference in refractive index from the upper layer to improve bottom emission efficiency.

The present disclosure relates to a polyimide-based resin film which is synthesized by the reaction of an acid anhydride compound having a specific structure and a diamine compound, thereby capable of ensuring excellent optical properties even under high temperature heat treatment conditions, and stably maintaining optical properties even during further heat treatment, a substrate for display device, and an optical device using the same.

Provided is a detachable layer-forming composition which, for example, contains an organic solvent and a polyamic acid, both ends of which are derived from a diamine and sealed with an aromatic dicarboxylic acid, such as the polyamic acid represented by this formula.

##STR00001##

In the formula, X represents a tetravalent aromatic group, Y represents a divalent aromatic group, R.sup.1-R.sup.4 each independently represent a hydrogen atom, a C1-10 alkyl group, or a C6-20 aryl group, and m is a natural number.

A method for manufacturing a patterned polyimide aerogel film on a substrate includes: dispensing a polyimide prepolymer sol onto a first portion of a surface of a substrate, a second portion of the surface of the substrate being substantially free of the polyimide prepolymer sol; forming a patterned film of a polyimide prepolymer gel on the substrate from the polyimide prepolymer sol; drying the polyimide prepolymer gel to form a patterned film of a polyimide prepolymer aerogel on the substrate; and curing the polyimide prepolymer aerogel on the substrate to form the patterned polyimide aerogel film on the first portion of the surface of the substrate, the second portion of the surface of the substrate being substantially free of the patterned polyimide aerogel film.

The disclosure provides a thermosetting polyimide resin and a manufacturing method thereof, a composition, a prepolymer, a film, an adhesive, and a use thereof. The composition includes at least: (a) a maleimide compound and (b) the thermosetting polyimide resin. The disclosure provides the thermosetting polyimide resin and the prepolymer, for manufacturing a film, an adhesive sheet, a cover film, a redistribution layer, a build-up board, a prepreg sheet, a high-frequency substrate, an integrated circuits carrier board, an adhesive for copper foil, a semiconductor packaging material, a radome, a substrate for server, a substrate for base station, a substrate for vehicle, etc.

A benzocyclobutene-containing polyimide resin and a benzocyclobutene-containing polyimide resin composition are provided. The composition includes: (a) a filler:hollow silica, a perfluoroalkoxy alkane resin, or a combination thereof, and (b) a benzocyclobutene-containing polyimide resin with characteristics of high heat resistance, low dielectric property, low elastic modulus, and suitable for manufacturing a redistribution layer and a polyamide film of a semiconductor packaging material in a high-speed and high-frequency field.