Abstract: This invention relates to a method for preparing a polyimide having good heat-stability and excellent flowability in a molten state.The polymide is prepared by reacting aromatic diamines such as 4,4'-bis(3-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl] ketone and bis [4-(3-aminophenoxy)phenyl] sulfone; tetracarboxylic dianhydrides such as pyromellitic dianhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride and bis(3,4-dicarboxyphenyl) ether dianhydride; and dicarboxylic anhydrides such as glutaric anhydride, 1,2-hexanedicarboxylic anhydride, phthalic anhydride and 3,4-benzophenonedicarboxylic anhydride. The molar ratio of aromatic diamine: tetracarboxylic dianhydride: dicarboxylic anhydride is 1:(0.9 to 1.0):(0.001 to 1.0).The invention also relates to polyimide composite materials which are excellent in mechanical strengths and processability.

Abstract: Disclosed is a process for preparing a polyimide by reacting certain reactants. The reactants include an aromatic diamine which is 3,3'-diaminobenzophenone and/or bis(3-aminophenyl)sulfone, a tetrocarboxylic dianhydride and a dicarboxylic anhydride. A thermally stable polyimide can be obtained which displays excellent processability.

Abstract: The invention relates to processes for preparing a polyimide, a polyimide composition prepared by the processes and polyimide composite materials containing the same.

Abstract: A process for the production of polyimide fibers and polyimide fibers obtained by the process. The process includes thermal or chemical imidation of a polyamic acid which has been obtained by reacting a specific diamine and a particular tetracarboxylic dianhydride in the presence of a dicarboxylic anhydride represented by the following formula: ##STR1## wherein Z represents a divalent group selected from the group consisting of monocyclic aromatic groups, fused polycyclic aromatic groups and non-fused polycyclic aromatic groups with aromatic rings bonded together directly or via a crosslinking member.

Abstract: This invention relates to molding resin compositions, and more particularly relates to polyimide resin compositions having markedly improved molding ability in addition to excellent high temperature stability, chemical resistance and mechanical strength.The polyimide resin compositions of this invention comprises 99.9 to 50.0% by weight of the polyimide and 0.1 to 50.0% by weight of aromatic polyamideimide.

Abstract: This invention relates to a novel polyimide and describes method of its preparation, adhesives of the polyimide and the method for their application.The polyimide has recurring units of the formula ##STR1## (where the positions of two carbonyl radicals in a benzene ring are meta or para, and R is a tetra-valent radical selected from the group consisting of aliphatic radical having not less than two carbons, cyclo-aliphatic radical, monoaromatic radical, condensed polyaromatic radical, and non condensed polyaromatic radical wherein aromatic radicals are mutually connected with a bond or a crosslinking function).The polyimide can be prepared by reacting diamine with tetracarboxylic dianhydride in organic solvents and imidizing resultant polyamic acid.The diamine in use is ether diamine and includes 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene and 1,4-bis[4-(3-aminophenoxy)benzoyl]benzene.

Abstract: A process for preparing a polyimide by reaction of a diamine and a tetracarboxylic dianhydride to obtain a polyamide acid and subjecting the polyamide acid to conversion into a polyimide thermally or chemically. The reaction in the process is carried out in the presence of at least one dicarboxylic anhydride selected from the group consisting of aliphatic dicarboxylic anhydrides and aromatic dicarboxylic anhydrides, and the amount of the tetracarboxylic dianhydride is in the range of from 0.9 to 1.0 mole per mole of the diamine and the amount of the dicarboxylic anhydride is in the range of from 0.001 to 1.0 mole per mole of the diamine. The resultant polyimides exhibit good thermal stability at high temperatures and good forming processability even at low temperatures.

Abstract: This invention relates to a novel polyimide which is high-temperature resistant and capable of being molded in a fused state. This invention also relates to a high-temperature adhesive using the polyimide.The polyimide consists essentially of recurring units of the formula: ##STR1## where R is a tetra-valent radical selected from the group consisting of an aliphatic radical having 2 or more carbon atoms, alicyclic radical, monoaromatic radical, condensed polyaromatic radical, and non-condensed polyaromatic radical wherein aromatic radicals are linked to one another directly or via a bridge member.The polyimide can be prepared by reacting bis[4-(4-aminophenoxy)phenoxy)phenyl] sulfone with a tetracarboxylic dianhydride in an organic solvent and imidizing the resultant polyamic acid.

Abstract: Polyimide of this invention is almost colorless and has remarkably high light transmittance as well as excellent processability and adhesive properties at high temperatures in addition to its substantial high-temperature stability.The polyimide is a novel polyimide capable of being used for space and aeronautical materials, electric and electronic members, automotive parts, and furthermore for high-temperature adhesives.The polyimide has recurring units of the following formula ##STR1## wherein X is a radical selected from the group consisting of a bond, divalent hydrocarbon radical having from 1 to 10 carbons, hexafluorinated isopropylidene radical, carbonyl radical, sulfonyl radical and thio radical, and each nitrogen atom of imide ring is located simultaneously at meta- or para-position to ether linkage.

Abstract: This invention relates to flexible copper-clad circuit substrates where copper foil is directly and firmly jointed with a polyimide film.Polyimide used is obtained conventionally by reacting diamine components including 3,3'-diaminobenzophenone, 1,3-bis(3-aminophenoxy)-bezene, 4,4'-bis(3-aminophenoxy)biphenyl, 2,2-bis[4-(3-aminophenoxy)-phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, bis[4(3-aminophenoxy)phenyl] sulfide, bis[4-(3-aminophenoxy)phenyl] ketone and bis[4-(3-aminophenoxy)phenyl] sulfone, with tetracarboxylic acid dianhydride including pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyl tetracarboxylic dianhydride and bis(3,4-dicarboxyphenyl) ether dianhydride, in organic solvent, and by thermally or chemically imidizing resultant polyamic acid.Polyimide thus obtained has relatively lower melt viscosity and is flowable at high temperatures.

Abstract: Polyimide having repeating units of the following formula (I) and its polyamic acid precursor having repeating units of the following formula (II) are disclosed; ##STR1## (where Y is a radial selected from the group consisting of a bond, divalent hydrocarbon having 1 to 10 carbons, hexafluorinated isopropylidene, carbonyl, thio, sulfinyl, sulfonyl and oxide, and R is a tetra-valent radical selected from the group consisting of aliphatic radical having 2 and more carbons, cyclo-aliphatic radical, monoaromatic radical, condensed polyaromatic radical, and noncondensed polyaromatic radical wherein aromatic radicals ae mutually connected with a bond or a crosslinking function).Typical examples of polyimide and polyamic acid include where Y is thio radical and R is ##STR2## Y is a bond and R is III or IV, andy is isopropylidene radical and R is IV.The polymers can be prepared from corresponding diamine and tetracarboxylic acid dianhydride.

Abstract: A polyimide film formed by using a symmetrical aromatic meta-substituted primary diamine and a symmetrical aromatic para-substituted primary diamine as raw materials in a specific proportion has excellent heat resistance, electrical properties, flexibility and the like. Such a polyimide film can be bonded to a metal foil not by using any adhesive, but by coating the metal foil with a polyamic acid constituting a precursor of the polyimide and further reacting the polyamic acid to convert it to the polyimide. In this manner, there can be obtained a flexible laminate for printed-circuit board comprising a polyimide film bonded to a metal foil with good adhesion and exhibiting excellent properties as described above.

Abstract: This invention relates to a novel polyimide and describes method of its preparation, adhesives of the polyimide and the method for their application.The polyimide has recurring units of the formula ##STR1## (where R is a tetra-valent radical selected from the group consisting of aliphatic radical having not less than two carbons, cyclo-aliphatic radical, monoaromatic radical, condensed polyaromatic radical, and non condensed polyaromatic radical wherein aromatic radicals are mutually connected with a bond or a crosslinking function).The polyimide can be prepared by reacting 2,6-bis(3-aminophenoxy)pyridine with tetracarboxylic dianhydride in an organic solvent and imidizing resultant polyamic acid.Various tetracarboxylic dianhydrides can be used and particularly prefered are pyromellitic dianhydride and 3,3',4,4'-benzophenonetetracarboxylic dianhydride.

Abstract: This invention discloses high-temperature adhesives having a good light-transmittance and excellent high-temperature flowability which comprises polyimide having recurring units represented by the following formula (I) ##STR1## (where R is a tetra-valent radical selected from the group consisting of aliphatic radical having not less than two carbons, cyclo-aliphatic radical, monoaromatic radical, condensed polyaromatic radical, and non condensed polyaromatic radical wherein aromatic radicals are mutually connected with a bond or a crosslinking function).

Abstract: This invention relates to a novel polyimide and describes the method of its preparation, adhesives of the polyimide and the method for their application.The polyimide has recurring units of the formula ##STR1## (where Y is ##STR2## and R is a tetra-valent radical selected from the group consisting of aliphatic radicals having not less than two carbons, cyclo-aliphatic radical, monoaromatic radical, condensed polyaromatic radical, and non condensed polyaromatic radical wherein aromatic radicals are mutually connected with a bond or a crosslinking function).

Abstract: This invention relates to a polyimide powder in use for adhesion and/or coat forming and to a method of preparing said powder, wherein polyamic-acid is chemically imidized which is obtained by reacting tetracarboxylic acid dianhydride with diamine in organic solvents.This invention further relates to a method for adhesion and coat forming by using said polyimide powder.This invention still further relates to a method for preparing prepreg by using said polyimide powder, and a method for adhesion and preparing molded laminates by using said prepreg.