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: Melamine cyanurate is prepared by heating melamine powder and cyanuric acid powder at 250.degree. to 500.degree. C. substantially in the absence of any liquid medium. The melamine cyanurate can be obtained in a granular form when the heating is conducted subsequent to granulation of a mixture of both the powders.

Abstract: A transparent panel heater which can be used for heating a window portion of liquid crystal displays, refrigerated showcases, freezed showcases, defrosters of windshields, and the like. The panel heater has a transparent substrate, a transparent conductive film formed on the substrate, a substantially light-transmittable metallic electrode-underling-layer formed on the transparent conductive film and a pair of metallic electrodes which are provided for electrifying the conductive film and formed on the electrode-underlying-layer. The transparent conductive film is a laminate of at least one transparent thin layer made of a nitride and/or a carbide and at least one substantially light-transmittable metallic layer. The transparent conductive film and electrode-underlying-layer are preferably formed by a dry process, and the electrodes are preferably formed by a wet plating method.

Abstract: A hydraulic cement composition comprising as an effective component a water-soluble amphoteric polymer obtained by Hofmann degradation reaction of an .alpha.,.beta.-unsaturated carbonamide polymer or a copolymer of .alpha.,.beta.-unsaturated carbonamide and an anionic monomer having a weight average molecular weight of 1,000-1,000,000.The primary amino group produced as a result of the Hofmann degradation reaction provides excellent cement dispersing capabilities.

Abstract: Articles which can be degraded and disappear in the natural environment are a degradable adhesive film which can be used for surface protection or indication after printing on the film surface and has an adhesive layer on one side of a substrate film obtained from a lactic acid base polymer such as polylactic acid and a lactic acid/hydroxycarboxylic acid copolymer having a molecular weight of 30,000-500,000, and a degradable resin composition which is excellent in weatherability and comprises 100 parts by weight of a lactic acid base polymer and 0.001-5 parts by weight of one or more additives selected from ultraviolet absorbers and light stabilizers.

Abstract: A formed thermoplastic resin article is made of a thermoplastic resin and a foamed elastic polymer finely dispersed in the thermoplastic resin. The formed thermoplastic resin article can be produced by blending an elastic polymer, in which an endothermic foaming agent decomposable at a temperature of at least 160.degree. C. was mixed in advance at a temperature lower than a decomposition temperature of the endothermic foaming agent, in a thermoplastic resin and then plasticizing and forming the resultant resin blend at a temperature at least equal to the decomposition temperature of the endothermic foaming agent.

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: In the process for preparing polysuccinimide by dehydration condensation of aspartic acid in an organic solvent, polysuccinimide can be obtained simply and suitably in industry by removing a portion or more of the organic solvent from the reaction mixture while charging to the reaction mixture an additional organic solvent containing less amount of water than that of the removed organic solvent.

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: A 2H-1-benzopyran-2-on compound represented by the formula (1): ##STR1## and a colorless ultraviolet absorber consisting of the compound, and a thermoplastic resin composition and formed article comprising said ultraviolet absorber. The compound can provide a thermoplastic resin composition and a formed article of the composition having excellent heat stability and sublimation resistance, comprise a non-coloring ultraviolet absorber, and are excellent in ultraviolet barrier property.

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: Provided by the present invention are novel diguanamine derivatives, led by 2,5/2,6-bis(4,6-diamino-1,3,5-triazin-2-yl)-bicyclo[2.2.1]heptanes and 1,3/1,4-bis(4,6-diamino-1,3,5-triazin-2-yl)-cyclohexanes, and derivatives thereof, applications of these compounds in fields such as adhesives and paints, utilization of these compounds in flame-retarding, thermal stabilization and compatibilization methods of resins, thermosetting molding compositions and thermosetting expansion-molding compositions making use of these compounds, as well as polymeric microspheres also using these compounds. These compounds are expected to find wide spread industrial utility as various excellent properties can be obtained by using them.

Abstract: A fiber excellent in strength and having an average size of 10,000-0.1 denier can be obtained by extruding a raw material composed mainly of a polypropylene having a syndiotactic pentad fraction of 0.7 or more and optionally stretching the resulting extruded material.By using as the raw material a composition consisting of two kinds of polypropylenes each having an intrinsic viscosity .eta..sub.1 or .eta..sub.2, the log(.eta..sub.2 /.eta..sub.1) being more than 0.05 or less than -0.05, and a syndiotactic pentad fraction of 0.7 or more at a weight ratio of 95:5-5:95 or a composition consisting of at least 50 parts by weight of a syndiotactic polypropylene having the intrinsic viscosity .eta..sub.1 and a syndiotactic pentad fraction of 0.7 or above and at most 50 parts by weight of an isotactic polypropylene having the intrinsic viscosity .eta..sub.2, the extrudability is improved and the fiber stretching conditions are broadened.

Abstract: A flexible polyurethane foam which has a low density, enhanced impact resilience, improved compression set and excellent effect on the reduction of 6 Hz vibration transmissibility and is obtained by a reaction of an organic polyisocyanate composition, that is, a mixture of (a) polymethylenepolyphenyl isocyanate containing from more than 60 to 90% by weight of a two benzene ring compound and having a weight ratio [three benzene ring compound]/[four or more benzene ring compounds + less active ingredient] of 1.1-20.0, and (b) tolylene diisocyanate in a ratio (a)/(b) of 97.apprxeq.80/3.apprxeq.20 by weight, or by reaction of a prepolymer derived from said organic polyisocyanate composition and a specific polyol, with a resin premix comprising a water blowing agent and an active hydrogen containing compound; and a process for preparing the flexible polyurethane foam.

Abstract: The present invention relates to a process for the preparation of a thermoplastic resin composite comprising conducting polycondensation of a monomer material in a solution of an organic solvent containing an organic solvent soluble polymer to form an aromatic condensation polymer which is insoluble in said organic solvent and a thermoplastic resin composite prepared by the process.

Abstract: The present invention relates to a method and apparatus for manufacturing a disk-type information recording medium such as an optical disk. The method and apparatus of the present invention involves the concept of automatically removing any surplus organic materials deposited on cylindrical outer surfaces of the disk and also provides for a disk-type information recording medium of a high quality finish. In the method and apparatus of the present invention, a cleaning belt is utilized to contact a disk which is positioned on a rotatable cleaning table to remove any organic materials existing on the cylindrical outer surface of the disk.

Abstract: The invention provides a polymeric insulating material having a high dielectric breakdown voltage. The material comprises polypropylene which has been obtained in a yield of at least 300,000 g/g-Ti based on titanium in a catalyst upon polymerization, contains ash in an amount not greater than 40 ppm by weight when analyzed by completely burning the polypropylene in air, said ash containing titanium in an amount not greater than 1 ppm by weight based on the weight of the polypropylene, and also contains chlorine in an amount not greater than 2 ppm by weight and boiling n-heptane soluble matter in an amount not smaller than 1 wt. % but not greater than 10 wt. %. According to the invention, it is possible to further improve the dielectric breakdown voltage by adding to the polypropylene an inorganic oxide or hydroxide free of particles of 10 .mu.m and greater in diameter and having an average particle size not greater than 1 .mu.

Abstract: The heat-sensitive recording material disclosed comprises a colorless or pale colored dyestuff precursor, one or more salicylic acid derivative of the formula (1) or metal salt of the derivative and an aliphatic amide compound having 18.about.60 carbon atoms in molecular structure, and is excellent in thermal response and preservation stability of white portions and images. ##STR1## wherein X.sub.1 and X.sub.2 are a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aralkyl group or an aryl group, Y.sub.1 and Y.sub.2 are an oxygen atom or a sulfur atom, R.sub.1 is a hydrogen atom, an alkyl group, an aralkyl group or an aryl group, and R.sub.2 is an alkyl group, an alkenyl group, an aralkyl group or an aryl group.

Abstract: This invention provides a process for the preparation of acrylamide. Acrylonitrile is treated through at least two purification steps in which acrylonitrile is brought into contact with a strongly-acidic cation exchange resin and then with a resin having primary and/or secondary amino groups or with activated carbon. The resulting acrylonitrile is subjected to hydration in the presence of a copper-base catalyst. The process of this invention can provide high-quality acrylamide even when acrylonitrile of ordinary quality is used, and permits preparation of a polyacrylamide suitable for use in the production of a coagulant having good water solubility or the like.

Abstract: A process for reusing a plastic article having a plastic body and a coating layer is discloses which includes the following steps: peeling the coating layer, formed on the plastic body, away from the plastic body by using a high pressure water jet stream; and pulverizing the plastic body for reuse. Hot water may be also used. Instead of the water, it is possible to use high pressure steam.