A method for producing a polyimide precursor having a structural unit represented by the following formula (1), comprising the following steps (i) and (ii), wherein at least one of the steps of (i) and (ii) is carried out in a solvent comprising a compound having an ether bond and an amide bond: (i) a step of reacting carboxylic anhydride with a diamine compound to obtain a polyimide precursor having a structural unit represented by the following formula (2); and (ii) a step of reacting the polyimide precursor having a structural unit represented by the formula (2) with a compound represented by the following formula (8), and reacting the reactant with a compound represented by the following formula (9) to obtain a polyimide precursor having a structural unit represented by the following formula (1):

##STR00001## wherein in the formula (1), at least one of R.sub.1 and R.sub.2 is a group represented by the formula (3):

##STR00002##

A resin composition is used which contains a maleimide compound represented by the following Formula (1), a modified polyphenylene ether compound of which a terminal is modified with a substituent having a carbon-carbon unsaturated double bond, and a crosslinking agent containing an allyl compound.

##STR00001##

In Formula (1), s represents 1 to 5 and R.sub.A, R.sub.B, R.sub.C, and R.sub.D each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a phenyl group.

A novel photocurable resin composition including: a polymer with a weight average molecular weight of 1,000 to 50,000, the polymer having a structural unit of formula (1), and having a structure of formula (2) at an end: wherein X is a C.sub.1-6 alkyl group, vinyl group, allyl group, or glycidyl group; m and n are each independently 0 or 1; Q is a divalent hydrocarbon group having a carbon atom number of 1 to 16; Z is a divalent linking group having a carbon atom number of 1 to 4, wherein the divalent linking group is attached to the O group in formula (1); and R.sup.1 is a hydrogen atom or methyl group; a radical photopolymerization initiator; and a solvent. ##STR00001##

This document discloses a process for manufacturing recyclable injection molded microcellular foams for use in, footwear components, seating components, protective gear components, and watersport accessories. The process includes the steps of providing a thermoplastic polymer which comprises at least one monomer derived from depolymerized post-consumer plastic, inserting a fluid into a barrel of a molding apparatus. The fluid is introduced under temperature and pressure conditions to produce a super critical fluid. The process further includes mixing the thermoplastic polymer and super critical fluid so as to create a single phase solution, and injecting the single phase solution into a mold of an injection molding machine under gas counter pressure. The process further includes foaming the single phase solution by controlling the head and temperature conditions within the mold.

This document discloses a process for manufacturing recyclable injection molded microcellular foams for use in, footwear components, seating components, protective gear components, and watersport accessories. The process includes the steps of providing a thermoplastic polymer which comprises at least one monomer derived from depolymerized post-consumer plastic, inserting a fluid into a barrel of a molding apparatus. The fluid is introduced under temperature and pressure conditions to produce a super critical fluid. The process further includes mixing the thermoplastic polymer and super critical fluid so as to create a single phase solution, and injecting the single phase solution into a mold of an injection molding machine under gas counter pressure. The process further includes foaming the single phase solution by controlling the head and temperature conditions within the mold.

A modified polyimide represented by Formula 4: ##STR00001##
wherein D is a heat curable or photocurable functional group, R is a divalent or higher polyvalent organic group, and n is an integer of 1 or greater, X.sub.1, X.sub.2, X.sub.3, and X.sub.4 are each independently a tetravalent organic group derived from a tetracarboxylic dianhydride, Y.sub.1, Y.sub.2, and Y.sub.3 are each independently a divalent organic group derived from a diamine, p, q, r, and v are each independently an integer of 0 or greater, with the proviso that p, q, r, and v are not simultaneously 0, and r+v is 1 or greater. Additionally, curable resin compositions including the modified polyimide, as well as polyimide films including a cured product of the curable resin composition, and methods for preparing the modified polyimide.

A photosensitive polyimide resin composition containing: a ring-closed polyimide resin (A) having a structure represented by Formula (1) and a weight average molecular weight of 70000 or less; and a polyfunctional radically polymerizable compound (B) having 4 or more and 100 or less radically polymerizable functional groups.

##STR00001##

A photosensitive polyimide resin composition containing: a ring-closed polyimide resin (A) having a structure represented by Formula (1) and a weight average molecular weight of 70000 or less; and a polyfunctional radically polymerizable compound (B) having 4 or more and 100 or less radically polymerizable functional groups.

##STR00001##

A modified polyimide represented by Formula 4:

##STR00001##

wherein D is a heat curable or photocurable functional group, R is a divalent or higher polyvalent organic group, and n is an integer of 1 or greater, X.sub.1, X.sub.2, X.sub.3, and X.sub.4 are each independently a tetravalent organic group derived from a tetracarboxylic dianhydride, Y.sub.1, Y.sub.2, and Y.sub.3 are each independently a divalent organic group derived from a diamine, p, q, r, and v are each independently an integer of 0 or greater, with the proviso that p, q, r, and v are not simultaneously 0, and r+v is 1 or greater. Additionally, curable resin compositions including the modified polyimide, as well as polyimide films including a cured product of the curable resin composition, and methods for preparing the modified polyimide.

The present invention relates to a modified polyimide including a terminal group represented by Formula 1: ##STR00001## wherein D is a heat curable or photocurable functional group, R is a divalent or higher polyvalent organic group, and n is an integer of 1 or greater. The modified polyimide undergoes less reduction in transmittance and is protected from discoloration when cured. Due to these advantages, the modified polyimide can provide a highly transparent colorless polyimide film. Particularly, the modified polyimide is suitable for use in display substrates, interlayer insulating films of semiconductor devices, passivation films, buffer coat films, insulating films for multilayer printed circuit boards, insulating films of OLEDs, and protective films of thin film transistors of liquid crystal display devices. The present invention also relates to a curable composition including the modified polyimide.