Mitsubishi Pencil Company, Limited

Agency of Industrial Science and Technology

Mitsubishi Pencil Kabushiki Kaisha

Takamasa Kawakubo

Yoshihisa Suda

Mitsuru Yoshida

Hiroko Kaneko

Akira Negishi

Masahiro Yamada

Takao Koyama

Wataru Mizutani

Yukifumi Shigematsu

Kiyosi Hirasawa

Sugiro Ohtani

Etsuro Oota

A carbon material for electrodes which is a graphite/glass like carbon composite material having a structure in which the crystals of the graphite are oriented in one direction in the matrix of the glass like carbon so as to possess an electrode reaction activity inherent in the graphite crystals, having a maximum pore diameter of 150 .ANG. or less, and having electrolyte non-penetrative properties substantially corresponding to those of the glass like carbon; and a process for preparing a carbon material for electrodes which comprises the steps of highly dispersing, composing and orienting a graphite fine powder of the sufficiently grown crystals in an organic substance which can leave a glass like and less graphitizable carbon when calcined in a non-oxidizing atmosphere, and then calcining and carbonizing the composition. The carbon material of the present invention permits applying both current and voltage to biological systems, has no toxicity, such mechanical strength as to permit detecting a trace portion and reproducibility, can measure an electrode reaction stably, and is inexpensive.

Carbon material for electrodes and process for preparing it

A working micro-electrode with a reference electrode prepared by coating a working micro-electrode with an insulating material except a working electrode portion, forming a silver layer on the coated surface, and then changing a portion of the silver layer into silver chloride which is the reference electrode; a working micro-electrode with a reference electrode and a counter electrode prepared by coating the working micro-electrode with the reference electrode with an insulating material, and then forming the counter electrode on the surface of the insulating material; and methods for preparing these composite micro-electrodes. Heretofore, even if the working electrode is thinly constituted, the merit of the micro-electrode has not been sufficiently utilized, since the reference electrode and the counter electrode have been thick. However, the present invention can solve this problem and can facilitate experiments in which the micro-electrode is necessary. Since an inexpensive material such as carbon can be used, the working electrode may be constituted so as to be disposable or can be cut off the used portion to repeatedly obtain a new electrode surface. Therefore, the working electrode of the present invention is economical.

Micro-electrode and method for preparing it

A carbon micro-sensor electrode is disclosed which is prepared by impregnating, adsorbing or chemically modifying a pure composite carbon wire having many micropores extending to its surface and interior with a reactant such as an enzyme, a metal complex compound, an organic compound or a metabolite; and a method for preparing this carbon micro-sensor electrode is also disclosed. The above-mentioned electrode can be used for a long period of time, since the reactant is received in the many micropores. Furthermore, after used, the electrode may be cut off to expose a new electrode surface, and this new electrode surface may be coated with a material which does not impede an electrode reaction, whereby the reactant can be prevented from flowing out. Thus, the carbon micro-sensor electrode of the present invention can be repeatedly utilized.

Carbon micro-sensor electrode and method for preparing it

A tapered carbon microelectrode is produced by extruding an organic material or a composition composed of crystalline carbon fine powder and an organic binder into a thin rod form, carbonizing said rod by calcining to produce a pure carbon thin rod, soaking the resulting thin rod as an anode in an electrolytic solution, gradually pulling up the thin rod while electrochemically oxidizing the tip portion of the thin rod. Then a lead wire is connected with the thick portion of the thin rod followed by coating all the surface except the conically sharp tip portion. The tapered carbon electrode can be used for various electrochemical measurements and scanning tunneling microscope.

Tapered carbon microelectrode and process for production thereof

An inplant material for a living body hard tissue which is constructed by forming a core of a carbon material having a smooth and high hardness surface, an excellent mechanical strength against bending and compressing strengths, and non-impregnable to blood, lymph or the like and further forming a porous layer having a thickness of 100 microns or larger, preferably 100 microns or large on the surface of the core. This porous structure of the implant material is very important to smoothly and rigidly bond the material to a living body and is devised to produce the state that a collagen fiber newly produced in the boundary between the living body and the implant material is intruded into the porous tissue of the surface of the implant material and mutually interchanged, and a process for producing the same. Thus, the implant material has a smooth and high hardness surface, an excellent mechanical strength against bending and compressing strengths, and being non-impregnable to blood, lymph or the like.

Process for producing carbonaceous implant material

A process for preparation of a carbon fiber composite reinforced carbonaceous material characterized in that using carbon fibers or the raw material fibers of the carbon fibers as the base material, the surfaces of said base material fibers even to the surface of the single fiber are uniformly and completely coated with dormant mesophase pitch and/or isotropic pitch, and after said base material has been molded, the resulting product is subjected to carbonization treatment or graphitization treatment.

Process for preparation of carbon fiber composite reinforced

A process for producing a carbon product having coarse and dense structures by carbonizing moldings of a mixture of one or more types of organic polymer substance, asphalt pitches, dry distilled pitches to obtain a dense structure carbon by carbonizing in an inert gas atmosphere or with a mixture of fine particle graphite powder as required, and porous organic polymer produced in point contact between the particles by solubilizing the surface layers of the organic polymer particles to obtain coarse structure carbon by sintering in particle state by carbonizing in an inert gas atmosphere, in an inert gas atmosphere after solidification to integrally mold organic liquid composition remaining high carbon residue in a composite composition, and carbonizing the composite composition in an inert gas atmosphere. Thus, a carbon product of continuously irregular quality having coarse and dense structure as designed by integrally producing a porous carbon having high strength and uniform porosity distribution with dense structure carbon moldings can be produced.

Process for producing carbon product with coarse and dense structure

A coiled resistance heating element of carbonaceous or graphite material is disclosed. A simplified process which includes carbonization or graphitization of a coiled strand of an organic material is also disclosed.

Coiled resistance heating element of carbonaceous material

Porous materials of carbon can be manufactured by introducing particles of organic polymer in a vessel of an arbitrary shape, dissolving a particle surface layer to produce point bondings between the particles, thereby producing porous materials of organic polymer, then insolubilizng or infusibilizing it, and further calcining the particles in inert gas atmosphere, thereby obtaining the porous materials of carbon fundamentally as sintered particle materials. Thus, this process permits, essentially without difficult means of managing complicated steps such as impregnating or extracting, facilitated manufacture of porous materials of carbon having a large quantity of continuous pores with ready adjustments of porosity and diameters of the pores and high strength.

Process for producing porous materials of carbon

A process for producing a carbon product having coarse and dense portions, the process including producing an integral porous carbon having high strength and uniform porosity distribution with dense structure carbon moldings. The carbon moldings are produced by calcining in an inert gas atmosphere a composite of (a) a green molding, a precarbonized material or a carbide and (b) chlorinated vinyl chloride resin particles, the chlorinated vinyl chloride resin producing, when carbonized in an inert gas atmosphere, a coarse structure. Dense carbon is formed by carbonizing the green molding, precarbonized material or carbide. Thus, the carbon product has coarse and dense portions.

Process for producing carbon product having coarse and dense structure

An improved process for producing hard carbonaceous sheets, which comprises uniformly dispersing as a viscous binder in fine carbon powder a mixture of relatively readily polymerizable thermosetting resins such as monomers, prepolymers or low polymers exhibiting high residual carbon yield after calcining; applying mechanical energy to the resultant mixture to induce mechanochemical phenomenon to produce molding paste composition in which said binder is uniformly rigidly bonded physicochemically to the surfaces of the primary particles of the fine powder, molding the composition by a fluid rolling method or a coating method in a film or sheet shape; infusibilizing the resultant molding; and calcining the resultant molding in an inert gas atmosphere. Thus, the hard carbonaceous sheets thus produced have small porosity, high mechanical strength, high elastic modulus, isotropy and uniform thickness of several microns to several mm using widely available and inexpensive manufacturing processes.

Process for producing hard carbonaceous sheets

A process for producing a carbon heat generator is disclosed including the steps of uniformly dispersing one or more types of metal compounds capable of forming a vitreous film upon oxidation in a moldable composition, molding the resultant dispersed composition, precarbonizing the molded composition, and then carbonizing the composition in a nonoxidative atmosphere to form a carbon heat generator having an oxidation preventive glass film. The oxidation of the metal compound exposed on the surface of the molded composition by the use of an oxidative atmosphere forms a vitreous film which prevents oxygen from diffusing in the interior thereof. The film so produced can form a new glass film on a damaged portion by a self-recovery effect if a pinhole or a crack occurs in the glass film. Thus, the process does not cause external appearance and weight differences before and after heat generating.

Process for producing carbon heat generator

A carbon spring composed substantially of carbonaceous carbon or graphite carbon is prepared by shaping an organic linear material to a coiled spring and thereafter heating it to carbonize.

Carbon spring and process for preparing the same

A method of fabricating an eraser which contains a main basic material of low crystallizable polyolefin thermoplastic elastomer and normal synthetic rubbers having no hard segment for performing a crosslinking effect, namely, any one or more of chlorinated polyethylene, ethylene-propylene terpolymer, ethylene ethyl acrylate, ethylene-vinyl acetate copolymer, atactic polypropylene, styrene-butadiene rubber, nitrile rubber and the like. The thermoplastic elastomer exhibits similar properties to vulcanized rubber without particular vulcanizing operation and crosslinking reaction. In case that less than 40 parts by weight of the elastomer is contained in the eraser, the composition does not form an eraser, while in case that higher than 100 parts by weight of the elastomer is contained in the eraser, the composition incorporates excessive rubber-like properties. The method comprises the steps of mixing and kneading 50 to 800 parts by weight of factice, 0 to 500 parts by weight of filler and predetermined amount of pigment which 40 to 100 parts by weight of the low crystallizable polyolefin thermoplastic elastomer. Thus, the eraser is remarkably improved in the properties such as resistances to deterioration by aging, exposure to sunlight, migration of plasticizer, and tearing strength by its metallic band.

Growing community of inventors

Gunma, Japan

Takamasa Kawakubo