Abstract:
A slurry containing a precursor fiber convertible to carbon fiber and/or a carbon fiber and a thermosetting resin is processed into a random web. The web is hot-pressed between a pair of belts while curing of the resin is inhibited to prepare a prepreg sheet. The sheet is disposed, leaving a clearance, in a mold having ribs on a molding surface and heated over the melting point of the resin for expansion and complete cure to provide a porous composite sheet equipped with grooves. This porous composite sheet is carbonized or graphitized to produce a porous carbonaceous material for use as a fuel cell electrode material and so on. This porous carbonaceous material has high homogeneity, gas permeability, electrical conductivity, heat conductivity and mechanical strength.
Abstract:
A porous tube of a fiber-reinforced plastic, which consists basically of fiber having a high tensile elastic modulus, such as glass fiber, and a matrix resin, such as polyethylene, and which has open cells and a high mechanical strength. This porous tube is useful as a constructional material for architectural and civil engineering work, a filter material, an air diffusing tube and a draining material.
Abstract:
A Mn-based alloy is disclosed. The alloy is comprised of 4 to 30 atomic % of at least one element selected from the group consisting of AI, Ni, and Cr; 1 to 15 atomic % of C, 30 atomic % or less of at least one element selected from the group consisting of Co, Mo, W, Ta, Nb, V, Ti, and Zr; and the balance of alloy making up 100 atomic % being comprised substantially of Mn. The alloy has a nonequilibrium austenite phase. The alloy disclosed has high ductility and workability. The alloy is capable of being cold worked and has excellent tensile strength. The Mn-based alloy can be pioduced at substantially the same cost as any Fe-based alloy. The disclosed alloy is a nonmagnetic alloy which has been found to be very useful for nonmagnetic electromagnetic parts and composite materials.
Abstract:
This invention provides a polyimide precursor solution having high concentration and low viscosity and a production process thereof, and polyimide coatings and films having excellent physical properties obtained therefrom and a production process thereof. Particularly, it relates to a polyimide precursor solution which contains a salt of a specific diamine with a specific tetracarboxylic acid, as its solute; to a process for the production of the polyimide precursor solution, which comprises allowing 1 mole of a specified diamine to react with 0.3 to 0.9 mole of a specific tetracarboxylic acid dianhydride, thereby obtaining a diamine, and subsequently adding 0.95 to 1.05 moles of a specified tetracarboxylic acid to 1 mole of the thus obtained diamine; to a polyimide coating or film obtained from the aforementioned polyimide precursor solution; and to a process for the production of the polyimide coating or film, which comprises coating the aforementioned polyimide precursor solution on a substrate and heating the coat to effect imidization.
Abstract:
A water-disintegrable sheet having biodegradability. The sheet comprises one or more kinds of biodegradable synthetic fibers, and one or more kinds of natural fibers and/or regenerated fibers, all the fibers being bound together by a binder such that the binding power of the binder will be substantially lost in water. The sheet has a given degree of tensile strength and good softness, coupled with a required degree of liquid absorbency, and still has some biodegradation property. Therefore, the sheet can be flushed in a flush toilet without involving any appreciable increase in the volume of solid residues in a septic tank and/or in a sewage disposal plant and is therefore suitable for use in the form of a wet wiper in particular.
Abstract:
Amorphous metal filaments having a substantially circular cross-section comprising an alloy containing Fe as a main component, and a process for producing such amorphous metal filaments, are described. The process comprises jetting a molten alloy 4 having amorphism forming ability into a revolving drum 6 containing a cooling liquid from a spinning nozzle 2 to form a solidified filament by cooling, and continuously winding the filament on the inner wall of said revolving drum 6 by means of the centrifugal force of said revolving drum 6, wherein the circumferential rate of revolution of said revolving drum 6 is equal to or higherthan the rate of jetting of molten metal from the spinning nozzle 2. These metal filaments have good corrosion resistance, toughness and high magnetic permeability and are very useful in various industrial applications, such as electric and electronic parts, materials for reinforcement, and fiber materials.