The Yokohama Rubber Co., Ltd.

Zeon Corporation

Riken Corporation

Misao Hiza

Hajime Yamazaki

Kazuhiro Takahashi

Yusuke Tanabe

Tomokazu Shirai

Ryoko Orishimo

Kazuya Uenishi

Shigeo Omote

Kazuhiro Sugihara

Tetsu So

Masao Nakamura

Koichi Endo

Naoya Amino

Takashi Shirokawa

A method enables olefin compound production with a high productivity, and an enzyme is used in the method. Mutations involving amino acid substitution are introduced into various sites of diphosphomevalonate decarboxylase (MVD) to prepare multiple MVD variants. Then, these variants are evaluated in terms of catalytic activity for producing an olefin compound such as isoprene, and have found as a result that the catalytic activity is improved when serine at position 153 and threonine at position 209 are each substituted with a different amino acid. In addition, the catalytic activity of the variants is further improved when glycine at position 152 is further substituted with a different amino acid.

Diphosphomevalonate decarboxylase variant and method for manufacturing olefin compound using same

Mutations involving amino acid substitution were introduced into various sites of diphosphomevalonate decarboxylase (MVD), thus preparing a large number of MVD variants. Then, the variants were each evaluated in terms of a catalytic activity for production of olefin compounds such as isoprene. As a result, it was found that substitution of glycine at position with a different amino acid resulted in improvement in the catalytic activity. In addition, it was found that the MVD in which arginine at position and threonine at position in addition to the position were further substituted with different amino acids, respectively, also had the high catalytic activity.

Diphosphomevalonate decarboxylase variant and method for producing olefin compound by using the same

A method which enables olefin compound production with a high productivity and an enzyme used in the method, a mutation involving amino acid substitution has been introduced into various sites of diphosphomevalonate decarboxylase (MVD), thus preparing a large number of MVD variants. Next, the result of evaluating the variants for the catalytic activity related to the production of olefin compounds such as isoprene has revealed that MVD whose threonine at position 209 is substituted with a different amino acid has the catalytic activity, and that MVD whose arginine at position 74 is further substituted with a different amino acid in addition to position 209 has the catalytic activity at higher levels.

Diphosphomevalonate decarboxylase variant, and method for producing olefin compound by using the same

A terminal-modified polymer is manufactured by performing a polymerization reaction of a vinyl aromatic monomer, a conjugated diene monomer or both in the presence of an anionic polymerization initiator: and then adding an alkoxy aluminum compound thereinto to terminate the polymerization reaction. Alternatively, a terminal-modified polymer can also be manufactured by adding an aluminum halide compound instead of the alkoxy aluminum compound to terminate the polymerization reaction, and allowing for a reaction with a lower alcohol having 1 to 4 carbon atoms. The resulting terminal-modified polymer can improve the dispersibility of silica used as a compounding agent in rubber compositions for automobile pneumatic tires and the like.

Method of manufacturing terminal-modified polymer

A terminal-modified polymer is manufactured by performing a polymerization reaction of a vinyl aromatic monomer, a conjugated diene monomer or both in the presence of an anionic polymerization initiator: and then adding an alkoxy titanium compound thereinto to terminate the polymerization reaction. Alternatively, a terminal-modified polymer can also be manufactured by adding an titanium halide compound instead of the alkoxy titanium compound to terminate the polymerization reaction, and adding for a reaction with a lower alcohol having 1 to 4 carbon atoms. The resulting terminal-modified polymer can improve the dispersibility of silica used as a compounding agent in rubber compositions for automobile pneumatic tires and the like.

A rubber composition containing (i) a conjugated diene-based rubber gel having a toluene swelling index of 16 to 70, (ii) a diene-based rubber such as natural rubber, polyisoprene rubber, aromatic vinyl-conjugated diene copolymer rubber and/or polybutadiene rubber, and (iii) an optional carbon black and/or silica and (a) a pneumatic tire using this composition as a high hardness reinforcing layer extending from a bead along a tire sidewalls, in which the fluidity and dimensional stability at the time of extrusion are improved, while maintaining a sufficient hardness of a high hardness reinforced rubber, (b) a pneumatic tire using this composition as two ends of a tire tread extrudate, maintaining a flex fatigue of the two ends of the tread, in which the extrudability and extrusion dimensional stability are improved and (c) a pneumatic tire using the composition as a 1.5 mm to 6 mm thick undertread, in which a high elasticity and relatively thick gauge undertread, and excellent processability and steering stability are provided.

Rubber composition and pneumatic tire using the same

A microwave absorptive composite suitable for use in ships, aircrafts and the like comprises an outermost layer of a thermosetting resin-impregnated, fibrous sheet; an intermediate layer of a normally liquid, carbonblack-containing silicone rubber sheet; and an innermost layer of a reinforced thermosetting resin sheet, the three layers being integrally laminated in that order. The silicone rubber is curable at room temperature or with heat.

Microwave-absorptive composite

A multi-layered microwave absorber suitable for use in ships, aircrafts and the like comprises a plurality of layers differing in impedance which are bonded together into an integral sheet structure by a silicone-type adhesive compound applied to a coat thickness of less than 0.1 mm. The absorber is capable of wave absorption over a wide band, free from deformation or distortion, and highly heat-resistant and weather-proof. A method of manufacturing the multi-layered microwave absorber is also disclosed.

Multi-layered microwave absorber and method of manufacturing the same

An adhesive composition comprising, by weight, (1) 100 parts of triglycidyl ether of trisphenol, (2) 0-40 parts of a polyfunctional epoxy resin, (3) a diamine type curing agent selected from (a) an aromatic diamine compound and (b) a reaction product having an amino group at each terminal thereof, prepared by reacting together an aromatic diamine compound, divinylsilane compound and bismaleimide compound, and, if desired, (4) a powdery inorganic filler.

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Hiratsuka, Japan

Misao Hiza