The Yokohama Rubber Co., Ltd.

Zeon Corporation

Riken Corporation

Yusuke Tanabe

Kazuhiro Takahashi

Misao Hiza

Tomokazu Shirai

Ryoko Orishimo

Ryutaro Nakagawa

Shun Sato

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

The present technology provides a rubber composition for sidewalls containing, a diene rubber, from 10 to 120 parts by mass of a carbon black, and from 3 to 30 parts by mass of an acid-modified polyolefin having a melting point of from 100 to 150&#xb0; C. per 100 parts by mass of the diene rubber, a main chain of the acid-modified polyolefin being a homopolymer of an olefin; and a pneumatic tire using the same in sidewalls thereof.

Rubber composition for sidewalls, and pneumatic tire using same

A rubber composition includes a diene rubber (A), a silica (B), a silane coupling agent (C), and an acid-modified polyolefin (D); the diene rubber (A) containing not less than 30 mass % of an aromatic vinyl-conjugated diene copolymer rubber; the acid-modified polyolefin (D) having at least one type of repeating unit selected from the group consisting of propylene, 1-butene, and 1-octene; a content of the silica (B) being from 5 to 150 parts by mass per 100 parts by mass of the diene rubber (A); and a total content of the silane coupling agent (C) and the acid-modified polyolefin being from 5 to 30 parts by mass per 100 parts by mass of the diene rubber (A). Such rubber composition is capable of achieving both excellent vulcanization properties and low heat build-up. A pneumatic tire includes such rubber composition.

Rubber composition and pneumatic tire including the same

The present invention is to provide a polymer which has a C&#x2014;P bond. The present invention can provide a phosphoric acid-modified polymer having a double bond, and a phosphorus substituent containing a phosphorus atom that directly bonds to a carbon atom.

Phosphoric acid-modified polymer

A rubber composition includes a sulfur-crosslinkable diene rubber, from 1 to 100 parts by mass of carbon black and/or from 5 to 150 parts by mass of an inorganic filler, from 0.5 to 30 parts by mass of a sulfur-containing compounding agent, and from 0.01 to 20 parts by mass of a phosphine borane compound based on 100 parts by mass of the sulfur-crosslinkable diene rubber. The rubber composition may be applied in at least one type selected from the group consisting of a capped tread, a side wall, a belt, an inner liner, a carcass, and a bead of a pneumatic tire.

Rubber composition and pneumatic tire using same

The present technology provides a rubber composition wherein from 1 to 100 parts by mass of carbon black and/or from 10 to 150 parts by mass of inorganic filler, from 1 to 30 parts by mass of sulfur-containing compounding agent, and from 0.1 to 20 parts by mass of tin oxide compound, are blended per 100 parts by mass of sulfur-crosslinkable diene rubber; and a pneumatic tire that uses this rubber composition in a cap tread.

Rubber composition and pneumatic tire using the same

Provided is a rubber composition having an intramolecular double bond capable of sulfur cross-linking, comprising at least one of 1 to 100 parts by mass of carbon black and 10 to 150 parts by mass of an inorganic filler other than carbon black, 0.1 to 50 parts by mass of a sulfur-containing compounding agent and 0.1 to 30 parts by mass of a hydrocarbon compound with both terminal groups thioesterified, per 100 parts by mass of the rubber having an intramolecular double bond capable of sulfur cross-linking. This rubber composition can provide a vulcanized substance having excellent toughness, for example, as a part of at least one of a cap tread, a side wall, a belt, an inner liner, a carcass and a bead of a pneumatic tire without substantially reducing processability of an unvulcanized substance and vulcanizate physical properties of the vulcanized substance.

Rubber composition having intramolecular double bond

The present invention provides a rubber composition formed by blending from 1 to 100 parts by mass of carbon black and/or from 5 to 150 parts by mass of an inorganic filler, from 0.5 to 30 parts by mass of a sulfur-containing compounding agent, and from 0.01 to 20 parts by mass of a boron-containing compounding agent into 100 parts by mass of a sulfur-crosslinkable diene rubber, and a pneumatic tire in which the rubber composition is used in at least one type selected from the group consisting of a capped tread, a side wall, a belt, an inner liner, a carcass, and a bead.

Growing community of inventors

Hiratsuka, Japan

Yusuke Tanabe