Abstract: A process for preparing a polyamide is provided. The polyamide is prepared by causing a dicarboxylic acid and a diamine to polycondensate directly under an atmosphere of an inert gas at atmospheric pressure. The polycondensation reaction is mainly carried out in two diamine component-adding steps, one step comprising adding part of the diamine to the molten dicarboxylic acid until the molar ratio of the diamine to the dicarboxylic acid is brought to within the range of from 0.900 to 0.990 while raising continuously the temperature of the reaction mixture to a temperature not exceeding about 5.degree. C. above the melting point of the object polyamide and the other step comprising adding the remainder of the diamine to the reaction mixture maintained at a temperature higher than about 10.degree. C., but not exceeding about 35.degree. C. above the melting point of the object polyamide until the overall molar ratio of the diamine to the dicarboxylic acid is brought to within the range of from 0.995 to 1.005.
Abstract: Benzenecarboxylic acid ester is produced at a higher reaction rate in a better yield in a shorter time by reacting benzenecarboxylic acid having 8 to 10 carbon atoms or its anhydride with aliphatic alcohol having 7 to 11 carbon atoms in the presence of amorphous aluminum compound as a catalyst and an alkali metal compound as a promoter.
Abstract: A novel cyanic acid ester of an aromatic polycarbonate can be prepared by reacting an aromatic polycarbonate having one or two terminal hydroxyl groups with a cyanogen halide in an inert solvent at a temperature of -30.degree. to +65.degree. C in the presence of a base. Said cyanic acid ester and an admixture of said cyanic acid ester with other known cyanic acid ester, both of which may or may not contain a catalyst and/or other polymers are available for a coating material, a casting material, an adhesive or a molding material. When said cyanic acid ester or said admixture is cured, there is obtained a laminate, a film or a molded article. The cured products are rich in flexibility.
Abstract: A polyphenylene ether random copolymer excelling in heat resistance and resistance to solvents, said copolymer being composed of 50-98 mol% of a structural unit of the formula ##STR1## derived from 2,6-dimethyl phenol and 50-2 mol% of a structural unit of the formula ##STR2## derived from 2,3,6-trimethylphenol, each of said structural units being randomly arranged in the polymeric structure, said copolymer having an intrinsic viscosity, as measured in chloroform at 25.degree. C., of at least 0.3 dl/g.
Abstract: An aqueous dispersion of a polymer having a cationic charge on the surface of the polymer particles is used for treatment of fouled water. Said aqueous dispersion contains quaternary ammonium salt or inorganic or organic acid salt of a copolymer obtained by emulsion polymerization of, in the presence of a cationic surfactant, (a) 0.1 - 8.0% by weight based on total monomers of at least one .alpha.,.beta.-ethylenically unsaturated monomers containing basic nitrogen or at least one .alpha.,.beta.-ethylenically unsaturated monomers containing halogen and other (b) .alpha.,.beta.-ethylenically unsaturated monomers and/or (c) conjugate diene monomers, (b) and (c) being copolymerizable with said monomer (a). Said aqueous cationic dispersion is especially effective for treatment of fouled water containing anionic latexes.
Abstract: A thermoplastic blended composition comprising 15-80% by weight of polyphenylene ether, 5-60% by weight of a styrene resin and 2-15% by weight of an aromatic polycarbonate. The composition has superior heat resistance, fatigue resistance and processability.
Abstract: A method for manufacturing a metal foil- or plastic film-overlaid laminate which comprises completely covering a cleaned press plate with a cleaned metal foil, a cleaned plastic film or both of them in such a manner that the pressing surface of the press plate comes in intimate contact with the face side of said metal foil or plastic film, partially or completely sealing the resulting covering along at least two edges of the press plate, two of the edges being opposite to each other, applying the covered press plate to one or both sides of a laminating base, subjecting the resulting assembly to a laminating apparatus with heating under pressure, taking the assembly out of the laminating apparatus, and thereafter opening the covering to remove the press plate.