Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Provided is a terminal borinic acid group-modified polymer having a borinic acid group at least at a molecular terminus thereof, comprising a polymer of at least one of a styrene monomer and a diene monomer. The above terminal borinic acid group-modified polymer may be manufactured by performing a polymerization reaction of at least one of a styrene monomer and a diene monomer in the presence of an anionic polymerization initiator, and then adding a cyclic boronic anhydride to quench the polymerization reaction. When the resulting terminal borinic acid group-modified polymer is added to a silica-containing rubber composition for automobile pneumatic tires as a component thereof, the dispersibility of silica compounded therein can be improved, fully achieving a performance of a good balance between reduced rolling resistance inherent in silica and stability on a wet road.

Abstract: 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.

Abstract: 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.

Abstract: A pneumatic tire using, as a tread, a rubber composition including (A) 30 to 90 parts by weight of a conjugated diene-based rubber composed of 40 to 95% by weight of 1,3-butadiene unit and 5 to 60% by weight of aromatic vinyl monomer units and having a Tg of ?35° C. or more (B) natural rubber (BR), polybutadiene rubber (BR) and another styrene-butadiene copolymer rubber (SBR) different from the conjugated diene-based rubber (A) of 10 to 70 parts by weight of and (C) 10 to 110 parts by weight of, silica, or (A?) 30 to 90 parts by weight of a conjugated diene-based rubber composed of 30 to 94.9% by weight of 1,3-butadiene units 0.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An epoxy resin composition comprising:(a) a urethane modified epoxy resin obtained by reacting a compound having both epoxy and hydroxy groups with a urethane bond containing compound having an isocyanate group at the end thereof, which is obtained from (i) an organopolysiloxane compound having a molecular weight of 500 to 10000 and having at least two hydroxy groups per one molecule in the main chain or side chain thereof and (ii) a polyisocyanate compound; and(b) an active organic curing agent.

Abstract: The invention encompasses the synthesis of telechelic, i.e., terminally functional, macromolecular monomers (macromers) and their subsequent homo- and copolymerization. The macromers produced are asymmetric, having dissimilar head and tail groups which provide independent reaction sites. Macromers include .alpha.-phenyl-.omega.-t-chloropolyisobutylene, which can be reacted to form poly(methyl methacrylate-g-isobutylene). The graft copolymers provide novel physical properties which are the product of the respective grafts.