Abstract: A new type of aromatic polyamide powder including a large number of fine coalescible particles which have an average size of from 0.1 to 10 .mu.m, which include at least one aromatic amide polymer including 40 to 100 molar % of recurring m-phenylene isophthalamide units and 0 to 60 molar % of at least one other type of additional recurring aromatic amide units, for example, m-phenylene terephthalamide units, and which coalesce with each other to form porous agglomerates having an average size of from 10 to 400 .mu.m and a surface area of from 1 to 20 m.sup.2 /g, and can be compression molded, optionally in mixture with a reinforcing additive, for example, aromatic polyamide fibers having a length of 3 mm or less, at a temperature of 200.degree. to 400.degree. C. under a pressure of 300 to 1000 kg/cm.sup.2 for 20 minutes to 5 hours, to produce shaped articles having excellent mechanical properties and appearance.

Abstract: Hollow microspheres are made by a process which comprises forming a film of a dispersed particle film-forming composition (containing dispersed particles, a binder, a film stabilizing agent and a continuous liquid phase) across a coaxial blowing nozzle, applying a blowing gas at a positive pressure on the inner surface of the dispersed particle composition film to blow the film and form, in the region of the coaxial blowing nozzle orifice, hollow dispersed particle microspheres having stable film walls, removing the hollow microspheres, treating them to bring dispersed particles into point to point contact and harden them to obtain hollow green microspheres, and subsequently subjecting them to a sufficiently high temperature for a sufficient period of time to remove the continuous liquid phase and to sinter the dispersed particles at their points of contact to form within the walls of said hollow microspheres interconnecting voids that are continuous from the outer wall surface to the inner wall surface of th

Abstract: A process for producing an expanded or foamed body of a fluorocarbon resin comprising molding the resin in a molten state in the presence of a depolymerizable polymer, polyether or polycarbonyloxy compound.

Abstract: A molding composition which is essentially composed of a mixture of at least two polymers based on vinyl chloride and at least one water-soluble surfactant is described. One of the polymers is a sinterable vinyl chloride/alkyl acrylate copolymer which can contain, in addition, polymerized units of vinyl acetate and ethylene. At least one further polymer is a vinyl chloride polymer which can contain up to 5% by weight of polymerized units of vinyl acetate and ethylene. The molding composition is suitable for the production of sintered, porous, flexible moldings, in particular separator compartments for electric cells.

Abstract: A material is provided which has a positive thermal coefficient of resistance. The material is made of nickel particles sintered in a plastic matrix. The material is suitable in internal elements of electrochemical cells.

Abstract: A semisintered polytetrafluoroethylene article which is prepared by heating an unsintered polytetrafluoroethylene article at a temperature of at least the melting point of a sintered polymer, the article having an endothermic curve at a temperature of 345.+-.5.degree. C. on a crystalline melting chart measured with a differential scanning carolimeter and a crystalline conversion of from 0.10 to 0.85 defined by heat of fusion of the unsintered, semisintered and sintered polymer, and the crystallinity of the semisintered article measured by X-ray diffraction being from 80 to 93%. The article is expandable biaxially to afford a porous polytetrafluoroethylene material having an almost unporous surface.

Abstract: What is disclosed is a process for preparing R'.sub.3 SiNH-containing silazane polymers by contacting and reacting chlorine-containing disilanes with {R'.sub.3 Si}.sub.2 NH where R' is vinyl, hydrogen, an alkyl radical of 1-3 carbon atoms or the phenyl group. The silazane polymers are useful as chemical intermediates to produce silicon-containing chemical compounds. They are also useful in the formation of silicon carbide-containing ceramic materials.

Abstract: What is disclosed is a process for preparing R'.sub.3 SiNH-containing silazane polymers by contacting and reacting chlorine-containing disilanes with {R'.sub.3 Si}.sub.2 NH where R' is vinyl, hydrogen, an alkyl radical of 1-3 carbon atoms or the phenyl group. The silazane polymers are useful as chemical intermediates to produce silicon-containing chemical compounds. They are also useful in the formation of silicon carbide-containing ceramic materials.

Abstract: Masterbatches useful for lightweight polyamide molding or extrusion comprise polyamide, a pore-forming agent and a fusible binder that is compatible with the polyamide. Admixture of the masterbatch and granular polyamide polymer results in a polyamide composition which can be molded or extruded into a product having increased homogeneity and expansion uniformity.

Abstract: According to the invention, there is provided a highly hydrophilic and porous sintered body having open-cellular pores and including a polypyridine ring structure represented by the following formula of: ##STR1## (wherein n is an integer.) which is obtained by sintering a pulverized copolymer made from acrylonitrile, a conjugated diene monomer and an .alpha.,.beta.-unsaturated olefinic carboxylic ester represented by the following formula of: ##STR2## (wherein R.sub.1 is hydrogen, a lower alkyl group having 1 to 4 carbon atoms or a halogen; and R.sub.2 is an alkyl group having 1 to 6 carbon atoms.

Abstract: A porous thermoplastic sheet is formed by adding a material to a polymer latex to passivate the aqueous phase of the latex. An additional material of a preselected particle size, corresponding to the desired pore size of the final product is then added. The latex composition is gelled and is then formed into a sheet. The sheet is dried and cured or sintered and the solubles are extracted therefrom with a solvent. A preferred polymer latex is PTFE.

Abstract: Polytetrafluoroethylene resin tubes having small pore size and high porosity are produced by a process which includes stretching the tubes by drawing using a metal die and a metal plug. By using the die and plug, the stress necessary for stretching is converted to a compressive force in the thickness direction of the tube. This compressive force is an essential factor in producing the microporous structure of the tubes. In addition, when stretching is performed by drawing, a ratio of thickness to inside diameter of the tube of 0.07 or less can be easily achieved.

Abstract: Polyurethane plastics are dyed with dyestuffs of the formula ##STR1## wherein R.sub.1 denotes hydrogen, halogen, optionally substituted C.sub.1 -C.sub.4 -alkyl, optionally substituted C.sub.1 -C.sub.4 -alkoxy and optionally substituted C.sub.1 -C.sub.4 -alkylcarbonylamino and R.sub.2 denotes hydrogen, optinally substituted C.sub.1 -C.sub.4 -alkyl and optionally substituted C.sub.1 -C.sub.4 -alkoxy, while A and B denote optionally branched alkylene chains which can be identical or different and preferably have 2 to 6 carbon atoms, with formation of covalent bonds, in that the dyestuffs are added before or during the polyaddition reaction to the reacton mixture of polyol and polyisocyanate or to one of the components.