Abstract: An insulating material for coaxial cables, made at least in part with a polyolefin resin capable of heat-melt extrusion and a fluororesin powder as a nucleator, which material being capable of foam extrusion in the presence of a foaming agent; a coaxial cable made at least in part with a foam insulating layer prepared from the insulating material; and a method for producing a coaxial cable, by extruding, on a conductor, the insulating material to form a foam insulating layer. The insulating material for coaxial cables of the present invention containing a fluororesin powder such as PTFE as a nucleator provides a foamed article having fine and uniform cells, and a high expansion ratio. Such foamed article is superior in electric properties, and the coaxial cable having such insulating layer is superior in attenuation property. The material of the invention can obviate drying of the insulating layer, which contributes to an improved production efficiency of the coaxial cable and reduced production cost.

Abstract: A medical tube made of an organic polymer having a mechanical loss tangent of at least 0.5 at body temperature and a modulus of transverse elasticity of 1-1000 MPa at body temperature. The medical tube of the present invention can be easily inserted into the body, and gives less pain and less feeling of physical disorder during indwelling in the body or removal from the body.

Abstract: A foamable organic composition comprising a compound foamable to 50% or more comprising an organic polymer and a chemical foaming agent, and, as a physical foaming agent, at least one member selected from the group consisting of rare gases and carbon dioxide; and a method for producing a foamed article having a high expansion ratio by using said composition. According to the present invention, a foamed article having a uniform and fine foam structure and a high expansion ratio of not less than 75% (which is as high as when freon gas is used) can be obtained without causing environmental problems such as depletion of the ozon layer. When applied, in particular, to a foamed layer for an insulated conductor, such as foam-insulated electric wire which is required to have high performance insulation and is occasionally installed under severe conditions, the composition of the present invention advantageously provides an insulated conductor with no potential buckling.

Abstract: A fluorocarbon copolymer-insulated wire comprising, around a conductor, an insulating layer made of a composition comprising an ethylene-tetrafluoroethylene copolymer and an unsintered tetrafluoroethylene-propylene copolymer, which is resistant to heat, abrasion and oil, and improved in flexibility. The wire can be efficiently installed in a narrow space in various equipments and enables easy wiring work.

Abstract: A method for producing a thermoplastic polyurethane elastomer tube where the temperature of the mandrel and the extrusion pressure used for extruding a thermoplastic polyurethane elastomer are determined before preparing the tube. The temperature of the mandrel and the extrusion pressure are set to overlap two predetermined temperature ranges. One temperature range permits hot drawing of the tube preform, and the second temperature range provides a tube preform free from the occurrence of bubbles on its surface. After the two temperature and extrusion pressure ranges are determined, a thermoplastic polyurethane elastomer is extruded on the periphery of a heated mandrel under pressure using a mandrel temperature and extrusion pressure where the two predetermined ranges overlap. Thereafter, the mandrel is pulled out to provide a tube preform, and the tube preform is hot drawn to produce a tube having a desired outer diameter.

Abstract: A catheter consists of a torque transmitting portion which has rigidity sufficient for torque transmission and a flexible portion made of a material having a glass transition temperature for giving rigidity before insertion and flexibility after insertion. The torque transmitting portion maintains torque transmitting ability before, during and after insertion. The flexible portion maintains appropriate rigidity before and during insertion, which enables easy insertion, and gains flexibility after insertion by the body heat, which avoids hurting of the vulnerable insertion walls. Further, the torque transmitting portion may have a structure wherein a reinforcement of a coil or a braid of linear metal wires, specifically flat rectangular wires, is attached thereto to afford torque transmitting ability. Catheters having various functions and structures can be easily manufactured by extrusion-molding, or the like.

Abstract: A method for producing a silica glass optical fiber, which comprises coating carbon on the optical fiber with the use of the remaining heat of not less than 800.degree. C. possessed by the optical fiber just after heat wire drawing, for thermal decomposition of a carbon coat-forming gas comprised of one or more members selected from the group of halogenated hydrocarbons, hydrocarbons, and halogen molecules, which has 5 to 15 hydrogen atoms per 10 halogen atoms, and a reaction apparatus for coating carbon, wherein the area of the outer end of an exhaust region is greater than the transverse sectional area of a coating region, and the outer end is outwardly opened.

Abstract: A process and apparatus for producing an elongated body changing in elastic modulus longitudinally thereof with use of polymers without resulting in variations in the outside and inside diameters of the body even when the polymers are different in extrusion characteristics or swelling characteristics. The apparatus may include a feeder 1 for extruding a first polymer in a molten state and a feeder 2 for extruding a second polymer, which is different from the first polymer in elastic modulus and similarly in a molten state. The feeders alternately discharge the respective polymers, which are continuously fed to a long-land die 5 along with a lubricant supplied from a lubricant applicator 4. The polymers are formed into the desired shape and cooled in the die 5, and thereafter extruded.

Abstract: A composition for filling the spaces in bores penetrating walls and floors of buildings and having electric wires and cables extending therethrough or for filling the clearances at the joints of interior finishing materials of buildings. The composition comprises (a) 100 parts by weight of a curable polychloroprene in a liquid state at room temperature, (b) about 200 to about 700 parts by weight of a hydrated metallic oxide, and (c) about 20 to about 100 parts by weight of a heat-resistant fibrous material. The components (b) and (c) are contained in a combined amount of at least about 250 parts by weight per 100 parts by weight of the component (a). The composition will not soften, sag or drip in molten drops even when subjected to the high-temperature conditions of a fire, and gives a tough residual product retaining the original shape when burned and ashed, effectively preventing the spread of fire and assuring outstanding smoketightness.

Abstract: The herein-disclosed putty is for forming air-tight and smoke-tight seals under normal and fire exposure conditions, and bubbles up when heated with flame, producing a foamed carbonaceous layer having outstanding fire-retardancy. It is a mixture having a cone penetration value of 2-40 which includes (a) liquid or semi-solid organic material having a viscosity of 50-100,000 c.st. at 210.degree. F and (b) a phosphoric acid compound substituted with one or more nitrogen-containing groups. The putty may also contain (c) polyhydric alcohols and/or carbohydrates for increased fire retardancy, (d) blowing agents for increased insulating effect, (e) grease, for high temperature flow resistance, (f) heat resistant fiber, for reinforcement, (g) microballoons, for increased insulating effect and other additives. The enclosed drawing discloses particularly desirable proportions for the components (c) and (d) in relation to the amount of component (b).