Abstract: In a novel method of homo- or copolymerization of vinyl chloride, a specified coating agent is applied on the surfaces of the portions which will become into contact with the vinyl chloride monomer during the polymerization process. The coating agent is in a form of an aqueous solution of a modified condensation product of phenol and aldehyde, the pH of the solution being adjusted in a range that the product is dissolved at an ambient temperature upon coating of the solution and separates out of the solution upon being heated on the surfaces. The wall surface of the polymerization tank and the like is then coated with a thin film of the coating agent having a uniform thickness and being strongly adhered to the wall surface, thereby providing an excellent effect of preventing adhesion of the product polymer to the wall surface.

Abstract: Disclosed are an aromatic hydroxycarboxylic acid resin represented by the following formula (1): ##STR1## wherein each A group is the same or different and individually represents a substituted or unsubstituted phenylene or naphthylene group, R.sup.1 represents a hydrogen atom or a C.sub.1-4 alkyl group, R.sup.2 represents a hydrogen atom or a C.sub.1-10 alkyl, C.sub.1-10 alkoxyl, nitro or hydroxyl group, l stands for an integer of 0-100, m stands for an integer of 0-20 and n stands for an integer of 0-3 with the proviso that m stands for an integer other than 0 when all of the A group represent an unsubstituted or substituted phenylene group, a preparation process thereof and use of the same.

Abstract: Disclosed are an aromatic hydroxycarboxylic acid resin represented by the following formula (1): ##STR1## wherein each A group is the same or different and individually represents a substituted or unsubstituted phenylene or naphthylene group, R.sup.1 represents a hydrogen atom or a C.sub.1-4 alkyl group, R.sup.2 represents a hydrogen atom or a C.sub.1-10 alkyl, C.sub.1-10 alkoxyl, nitro or hydroxyl group, l stands for an integer of 0-100, m stands for an integer of 0-20 and n stands for an integer of 0-3 with the proviso that m stands for an integer other than 0 when all of the A group represent an unsubstituted or substituted a group, a preparation process thereof and use of the same.

Abstract: This invention relates to a novel thermoplastic and amorphous polyimide which is readily soluble in organic solvent, a novel aromatic diamino compound used for the polyimide, a preparation process thereof, a polyimide-based resin composition comprising the thermoplastic polyimide and a fibrous reinforcement, a process for preparing the resin composition, an injection molded article of the resin composition, a polyimide-based composite obtained by molding the above soluble and thermoplastic polyimide in combination with a fibrous reinforcement, and a fibrous reinforcement having a surface modified with the above polyimide.

Abstract: In a novel method of homo- or copolymerization of vinyl chloride, a specified coating agent is applied on the surfaces of the portions which will become into contact with the vinyl chloride monomer during the polymerization process. The coating agent is in a form of an aqueous solution of a modified condensation product of phenol and aldehyde, the pH of the solution being adjusted in a range that the product is dissolved at an ambient temperature upon coating of the solution and separates out of the solution upon being heated on the surfaces. The wall surface of the polymerization tank and the like is then coated with a thin film of the coating agent having a uniform thickness and being strongly adhered to the wall surface, thereby providing an excellent effect of preventing adhesion of the product polymer to the wall surface.

Abstract: This invention relates to a novel polyimide or polyimide copolymer having excellent heat resistance and greatly improved processability, and has a novel aromatic diamino compound used for the polyimide, a preparation process thereof, a polyimide-based resin composition comprising the polyimide or polyimide copolymer and a fibrous reinforcement, a process for preparing the resin composition, an injection molded article of the resin composition.The polyimide comprise a requisite structural unit having one or more recurring structural units of the formula: ##STR1## wherein L is an oxygen atom, carbonyl, isopropylidene or hexafluoroisopropylidene, and X is ##STR2## , and Ar is a tetravalent radical having 6 to 27 carbon atoms and being selected from the group consisting of a monoaromatic radical, condensed polyaromatic radical and noncondensed polyaromatic radical having aromatic radicals connected to each other with a direct bond or a bridge member.

Abstract: A polyimide resin composition substantially comprising 1 99.9.about.50 parts by weight of polyimide having recurring structural units of the formula ##STR1## and 2 0.1.about.50 parts by weight of a polyimide which improved melt flowability and is prepared by using 1,3-bis(3-aminophenoxy)benzene or 6,6'-bis(3-aminophenoxy)-3,3,3',3'-tetramethyl-1,1'-spirobiindane as essential diamine component, or polyether pyridine having recurring structural units of the formula: ##STR2## is disclosed. Further, a polyimide based resin composition comprising the polyimide resin composition or a polyimide copolymer obtained by using the above diamines and a fibrous reinforcement is disclosed. These compositions have remarkably good processability, excellent heat stability and repeated fatigue characteristics.

Abstract: Disclosed is an aromatic diamine compound represented by the formula (I) ##STR1## wherein R is H or CH.sub.3. Also disclosed is a bismaleimide compound represented by the formula (IV) ##STR2## wherein R is H or CH.sub.3, A resin forming composition comprising these compounds is also disclosed. The compounds are useful as raw materials for resins, and the resin forming composition and the resin can provide excellent heat resistance and impact resistance and low hygroscopicity.

Abstract: The present invention relates to an amorphous polyimide or a polyimide copolymer having a requisite structural unit consisting of one or more recurring structural units represented by the formula (1): ##STR1## wherein X is a direct bond, oxygen atom or sulfur atom, and R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are individually a hydrogen atom or methyl, and Ar is a tetravalent radical having 6 to 27 carbon atoms and being selected from the group consisting of a monoaromatic radical, condensed polyaromatic radical and noncondensed polyaromatic radical having aromatic radicals connected to each other with a direct bond or a bridge member.Polyimide and the polyimide copolymer of the invention has excellent heat resistance, is outstanding in melt-flow stability, has greatly improved processability, and can be applied to structural materials, and electric- electronic appliances.

Abstract: This invention relates to a novel thermoplastic and amorphous polyimide which is readily soluble in organic solvent, a novel aromatic diamino compound used for the polyimide, a preparation process thereof, a polyimide-based resin composition comprising the thermoplastic polyimide and a fibrous reinforcement, a process for preparing the resin composition, an injection molded article of the resin composition, a polyimide-based composite obtained by molding the above soluble and thermoplastic polyimide in combination with a fibrous reinforcement, and a fibrous reinforcement having a surface modified with the above polyimide.

Abstract: This invention relates to a novel fluorine-containing polyimide or polyimide copolymer being colorless and having transparency and very low dielectric characteristics, and has a novel aromatic diamino compound used for the polyimide, a preparation process thereof, a polyimide-based resin composition comprising the polyimide or polyimide copolymer and a fibrous reinforcement, a process for preparing the resin composition, an injection molded article of the resin composition.

Abstract: A color-developing composition comprises a multi-valent-metal-modified salicylic acid resin (Resin A) and a polycondensation resin (resin B) at a weight ratio of 90-30 to 10-70. Resin A is composed of 5-35 mole % of a structural unit (I) and 65-95 mole % of at least one structural unit (II) or 65-95 mole % of a coupled structural unit of at least one unit (II) and at least one unit (III) and has a weight-average molecular weight of 350-5,000. Resin B is composed of the unit (II) and/or the unit (III) and has a weight-average molecular weight of 350-5,000. ##STR1## wherein Z represents M/m, M being a metal ion of m valence and m being an integer; R.sub.1 and R.sub.2 represent H or a C.sub.1-12 alkyl, aralkyl, aryl or cycloalkyl group; R.sub.3 and R.sub.6 represent H or a C.sub.1-4 alkyl group; and R.sub.4 and R.sub.5 represent H or CH.sub.3.

Abstract: A polyimide comprising a requisite structural unit having one or more recurring structural units of the formula: ##STR1## such as the structural units of the formula ##STR2## Further, the present invention relates to a novel aromatic diamine which has a perfluoro radical and can be used as a raw material monomer of the polyimide, and a process for preparing the same.The polyimide can have an extremely low dielectric constant and is colorless, transparent and excellent in processability and heat resistance.

Abstract: A color-developing composition comprises a multi-valent-metal-modified salicylic acid resin (Resin A) and a polycondensation resin (resin B) at a weight ratio of 90-30 to 10-70. Resin A is composed of 5-35 mole % of a structural unit (I) and 65-95 mole % of at least one structural unit (II) or 65-95 mole % of a coupled structural unit of at least one unit (II) and at least one unit (III) and has a weight-average molecular weight of 350-5,000. Resin B is composed of the unit (II) and/or the unit (III) and has a weight-average molecular weight of 350-5,000. ##STR1## wherein Z represents M/m, M being a metal ion of m valence and m being an integer; R.sub.1 and R.sub.2 represent H or a C.sub.1-12 alkyl, aralkyl, aryl or cycloalkyl group; R.sub.3 and R.sub.6 represent H or a C.sub.1-4 alkyl group; and R.sub.4 and R.sub.5 represent H or CH.sub.3.

Abstract: Disclosed is an aromatic diamine compound represented by the formula (I) ##STR1## wherein R is H or CH.sub.3. Also disclosed is a bismaleimide compound represented by the formula (IV) ##STR2## wherein R is H or CH.sub.3, A resin forming composition comprising these compounds is also disclosed. The compounds are useful as raw materials for resins, and the resin forming composition and the resin can provide excellent heat resistance and impact resistance and low hygroscopicity.

Abstract: A polyimide comprising a requisite structural unit having one or more recurring structural units of the formula: ##STR1## such as the structural units of the formula ##STR2## The polyimide can have an extremely low dielectric constant and is colorless, transparent and excellent in processability and heat resistance, and also provides an aromatic diamine which is useful as a raw material monomer of the polyimide or a raw material of other various engineering plastics.

Abstract: A heat-resistant and thermoplastic polyimide which has low dielectric characteristics and recurring structural units of the following formula: ##STR1## wherein R is a tetravalent radical having from 2 to 27 carbon atoms and selected from the group consisting of an aliphatic radical, alicyclic radical, monoaromatic radical, condensed polyaromatic radical and noncondensed aromatic radical connected each other with a direct bond or a bridge member; aromatic diamines which are useful for the raw material monomers of the polyimide and have following formulas: ##STR2## and a process for preparing the polyimide of the above formula by reacting these aromatic diamines with a tetracarboxylic dianhydride in the presence of an aromatic dicarboxylic anhydride or aromatic monoamine, and successively thermally or chemically imidizing the resultant polyamic acid; are disclosed.

Abstract: A color-developing sheet using, as a color developer, polyvalent-metal-modified products of salicylic acid compounds composed mainly of a 3,5-di(.alpha.-methylbenzyl)salicylic acid derivative obtained by reacting a salicylic acid ester with an .alpha.-methylbenzyl halide in the presence of an acid catalyst and hydrolyzing the reaction product.Said color-developing sheet has excellent color developability at low temperatures and gives a color of excellent water resistance.

Abstract: Disclosed are a novel aromatic diamine; a polymide comprising 1,3-bis(3-aminobenzoyl)benzene or 4,4'-bis(3-aminobenzoyl)biphenyl as a diamine component and having recurring structural units represented by the formula (III): ##STR1## wherein R is a tetravalent radical selected from the group consisting of an aliphatic radical having from 2 to 27 carbon atoms, alicyclic radical, monoaromatic radical, condensed polyaromatic radical, and noncondensed aromatic radical connected each other with a direct bond or a bridge member, and X is a divalent radical of ##STR2## and a polyimide having a terminal aromatic group which is essentially unsubstituted or substituted with a radical having no reactivity with amines or dicarboxylic acid anhydrides or a composition comprising said polyimide.

Abstract: A color-developing sheet using, as a color developer, polyvalent-metal-modified products of salicylic acid compounds composed mainly of a 3,5-di(.alpha.-methylbenzyl)salicylic acid derivative obtained by reacting a salicylic acid ester with an .alpha.-methylbenzyl halide in the presence of an acid catalyst and hydrolyzing the reaction product.Said color-developing sheet has excellent color developability at low temperatures and gives a color of excellent water resistance.