Mitsubishi Rayon Company, Limited

Munetsugu Nakatani

Yoshitaka Imai

Hiroshi Sato

Yoshiteru Tanuku

Naoki Mochida

Hiroaki Yoneyama

Shuichi Sugimori

Nobuyuki Yamamoto

Naoyuki Fukahori

Jinko Izumi

Hideto Kakita

Hiroyuki Shimoyama

Toha Kobayashi

Susumu Sasaki

Hiroshi Nakatsui

A carbon fiber of a high tenacity and a high modulus of elasticity having a fiber diameter of 1 to 6 .mu.m, a strand tenacity of 430 kg/mm.sup.2 or more, a strand modulus of elasticity of 28 ton/mm.sup.2 or more and a density of 1.755 g/cm.sup.3 or more, and a process for producing the same. The above-mentioned carbon fiber has extremely useful properties as a raw material for composite materials to be used not only for sporting goods such as fishing rods or golf clubs but also in aerospace industries.

Carbon fibers having high tenacity and high modulus of elasticity and

Acrylonitrile precursor fibers are subjected to a flame-resisting treatment, in an oxidizing atmosphere, while being elongated at least 3%, until a density of 1.22 g/cm.sup.3 is reached. The fibers are further treated to increase density up to 1.40 g/cm.sup.3, and then heat treated while undergoing further elongation, followed by higher temperature heat treatment while under tension. The resulting fibers have excellent properties, including high strand tenacity, high strand modulus, and high density.

Process for producing carbon fibers of high tenacity and modulus of

Process for producing carbon fiber

A process for producing a carbon fiber having a tenacity of 450 kg/mm.sup.2 or more, preferably 500 kg/mm.sup.2 or more, and a modulus of elasticity of 25 ton/mm.sup.2 or more which comprises subjecting a polyacrylonitrile-type fiber to a flame-resisting treatment in a flame-resisting treatment furnace provided with a plural number of driving rolls in an oxidizing atmosphere at 200.degree. to 400.degree. C. under application of multistep elongation, during said treatment the respective percentage of elongation in said multistep elongation being set respectively at a value which is equal to or within .+-.3% of the value of the percentage of elongation En indicating an inflection point Pn obtainable from the load and the percentage of elongation determined in advance by experimental measurements, and then subjecting the treated fiber to carbonization.

Process for producing carbon fibers

An oil-adsorbing composition useful for removing oil from oil-contaminated water comprises a granulated mixture of 5-80 weight % of an inorganic filler capable of adsorbing oil and 95-20 weight % of a cross-linked polymer. The composition is melt-kneaded by mixing and crushing the ingredients while cross-linking the polymer.

Method of producing of treating material for oil-containing waste water

A polypropylene film which is useful for electrical devices is produced by biaxially stretching an unstretched polypropylene molded article having, on at least one side, a surface layer having .beta.-form crystals, of mean diameter over 7 .mu.m, under such conditions that the stretching temperature at the stretch initiation point is in the range of 145.degree. to 176.degree. C., and the stretch ratio in one direction is less than a factor of 8. The resulting stretched polypropylene film is characterized by excellent mechanical properties, a very dense inner structure, and high air-tightness. The surface of the film has an efficiently roughened, fine, uneven structure containing crater-like patterns or an isotropic network structure and an anisotropic network structure, which is aligned in the extrusion direction. Therefore, the polypropylene film of the present invention can be readily impregnated with insulating oils, and hence can be used in various electrical devices, such as capacitors, electric cables, transformers and the like.

Process for producing the polypropylene film for electrical appliances

A translucent polypropylene film containing no .beta.-type crystallization nucleating agent which has, on at least one side, a surface layer composed of a two- or three-dimensional network structure, in which at least 1,000 network elements constituting the said network structure are present per cm.sup.2 of the film surface. The said film is obtained in such a manner that an unstretched polypropylene film having, on at least one side, a surface layer having a K value, which represents the amount of .beta.-type crystals present at a portion from the surface to a thickness of 10% in the thick-wall direction, of at least 0.1 is biaxially stretched under such conditions that the stretching temperature at the stretch initiation point is in the range of 145.degree. to 176.degree. C. and the stretch ratio in one direction is less than 8 times. The above-mentioned film is excellent in mechanical properties, quite dense in inner structure and high in airtightness, and the surface thereof has a fine uneven structure or fibril-like network structure, and has a favorable haze. Accordingly, the said film is used as a film for packing medicines, hygienic materials and foods, and as an insulating oil-impregnated dielectric film for condensers.

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Ohtake, Japan

Munetsugu Nakatani