Abstract: The present invention discloses a molded product which is heat-resistant, has a high elongation and is produced by a process including the steps of (1) curing a substantially linear polyarylene thioether having a melt viscosity of about 1,000 to 15,000 poise, thereby forming a polyarylene thioether resin having a melt viscosity of about 5,000 to 16,000 poise and a non-Newtonian coefficient, n, of about 1.5 to 2.1, (2) melt extruding the formed polyarylene thioether resin, (3) taking off the extruded polyarylene thioether resin at an R.sub.1 (ratio of the taking-off speed to the extruding speed at the nozzle of the melt extruded product) of about 10 to 1,000 and (4) crystallizing the taken off polyarylene thioether resin until its crystallization degree is not lower than 20 wt %; and coated electric wires having the above molded product as a coating layer.

Abstract: A process for preparing carbon fibers wherein carbon fibers are prepared from the mesophase-pitch containing not more than 80% by weight of a quinoline-insoluble component and showing, under a polarization microscope, more than 70% of optically anisotropic region, comprising the steps of subjecting a mesophase-pitch showing a viscosity of 10 to 100 poise at a temperature of spinning of 330.degree. to 450.degree. C., to rotating-centrifugal-spinning in a rotating-centrifugal spinning machine with a peripheral velocity of rotating nozzle thereof of 300 to 1000 m/min and exposing the thus spun fibers of the mesophase pitch to a flow of a gas spouting into a spinning direction at a temperature of 280.degree. to 400.degree. C. and at a linear velocity of 50 to 200 m/sec, thereby preparing carbon fibers showing a random-mosaic structural pattern in cross section thereof perpendicular to fiber axis.

Abstract: An organic friction material having favorable mechanical, thermal and frictional properties and comprising phenolic resin, carbon fibers, steel fibers and filler is disclosed, the organic friction material not containing any asbestos.

Abstract: Alpha type calcium sulfate hemihydrate gypsum is obtained by suspending gypsum in an aqueous solution containing a specific monocarboxylate in a specific concentration and heating the resultant suspension in a specific temperature range under atmospheric pressure. The production of this alpha type calcium sulfate hemihydrate is accomplished at an increased rate by adding a specific monocarboxylic acid to the aqueous solution, suspending gypsum in the resultant solution and heating the resultant suspension in a specific temperature range under atmospheric pressure.

Abstract: In the thermal cracking of heavy petroleum oil (having an API specific gravity of not more than 25) in a tubular type heating furnace, a specific inorganic substance is added in a specific proportion to the heavy petroleum oil to prevent the heavy oil from undergoing coking inside the furnace.

Abstract: In the thermal cracking of a heavy petroleum oil (having an API specific gravity of not more than 25) in a tubular type heating furnace, possible occurrence of coking trouble inside the furnace can be prevented by applying a magnetic field of fixed magnitude transversely to the flow of the heavy petroleum oil being introduced into the furnace or by applying a fixed magnitude of magnetic field transversely and, at the same time, applying a fixed magnitude of direct-current voltage parallel to the flow of the heavy petroleum oil being introduced into the furnace. More effective prevention of occurrence of coking can be obtained by having a specific inorganic substance incorporated in the heavy petroleum oil before the oil is subjected to the magnetic field or to simultaneous application of the magnetic field and voltage.