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: 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: Preparation of 3,3'- or 3,4'-diaminobenzophenone by nitrating a chloronitrobenzophenone mixture obtained by the Friedel-Crafts reaction between 3- or 4-nitrobenzoyl chloride and chlorobenzene, and catalytically reducing and dechlorinating the resulting chlorodinitrobenzophenone mixture in the presence of a reduction catalyst and a dehydrochlorinating agent.

Abstract: 3,3'- or 3,4'-diamino benzophenone is prepared by catalytically reducing and dehalogenating, in the presence of a reduction catalyst and a dehydrohalogenation agent, a benzophenone compound or benzophenone compounds of the general formula ##STR1## in which X is a halogen atom at position 2 or 4 of the benzene ring and Y is hydrogen or a halogen atom and in which the nitro group is at position 3' or 4' of the benzene ring if Y is hydrogen, while Y is at position 4' and the nitro group is at position 3' of the benzene ring if Y is a halogen atom.

Abstract: Preparation of 3,3'- or 3,4'-diaminodiphenylmethane by catalytically reducing and dechlorinating, in the presence of a reduction catalyst, a dinitrobenzophenone compound having the formula ##STR1## wherein X is chlorine and attached to a position 4 or 6 on the benzene ring, and Y is hydrogen or chlorine with the proviso that when Y is hydrogen, the nitro group is attached to a position 3' or 4', and when Y is chlorine, Y is attached to a position 4' and the nitro group is attached to a position 3'.

Abstract: Disclosed is a color-developer for pressure-sensitive recording sheets, comprising a co-condensate of a reaction intermediate of a p-substituted phenol and a trifunctional or higher phenol, or a polyvalent metal salt of said co-condensate, said reaction intermediate being obtained by the reaction of said p-substituted phenol under acidic conditions with formaldehyde or a substance capable of generating formaldehyde.

Abstract: Disclosed is a color-developing composition for pressure-sensitive recording sheet material of the self-contained type comprising (A) 100 parts by weight of a copolymer obtained by reacting a p-alkylphenol having an alkyl moiety of from 1 to 12 carbon atoms and phenol with formaldehyde and (B) from 1 to 20 parts by weight of a hindered phenolic compound selected from phenols having an alkyl, alkylene or hydroxyl substituent radical in at least the 2- or 6-position, or both, of the benzene ring and derivatives thereof, the copolymer and the hindered phenolic compound being homogeneously dissolved in mutual solution. The hindered phenolic compound is either added to the starting materials for the preparation of the copolymer or, at the end of the copolymerization reaction, added to the resulting copolymer and dissolved homogeneously in mutual solution.

Abstract: Disclosed is a color-developing composition for pressure-sensitive recording sheet material of the self-contained type comprising (A) 100 parts by weight of a copolymer obtained by reacting a p-alkylphenol having an alkyl moiety of from 1 to 12 carbon atoms and phenol with formaldehyde and (B) from 1 to 20 parts by weight of a hindered phenolic compound selected from phenols having an alkyl, alkylene or hydroxyl substituent radical in at least the 2- or 6-position, or both, of the benzene ring and derivatives thereof, the copolymer and the hindered phenolic compound being homogeneously dissolved in mutual solution. The hindered phenolic compound is either added to the starting materials for the preparation of the copolymer or, at the end of the copolymerization reaction, added to the resulting copolymer and dissolved homogeneously in mutual solution.