Abstract: A process for producing a conjugated diene-based polymer which comprises, in the first modification, modifying a conjugated diene-based polymer having active chain ends, which is obtained by polymerizing a diene-based monomer singly or with other monomers and has a content of a cis-1,4 unit of 75% by mole or greater in the conjugated diene portion of the main chain, by reacting the active chain ends with a hydrocarbyloxysilane compound and reacting the modified polymer with a specific compound such as a hydrocarbyloxysilane compound, and a rubber composition containing the polymer modified in accordance with the above process and, preferably, 10 to 100 parts by weight of silica and/or carbon black per 100 parts by weight of the rubber component containing the modified polymer, are provided. The rubber composition containing silica and/or carbon black exhibits improved fracture properties, abrasion resistance, low heat buildup property and excellent workability.

Abstract: This invention provides a modified natural rubber latex formed by charging a polar group-containing mercapto compound into a natural rubber latex to add the polar group-containing mercapto compound to a natural rubber molecule in the natural rubber latex, a modified natural rubber formed by coagulating and drying the modified natural rubber latex, and the rubber composition using the modified natural rubber and being excellent in the low loss factor, wear resistance and fracture characteristics.

Abstract: The present invention provides natural rubber latex in which glucans being polysaccharides contained in the latex are decomposed by treating the natural rubber latex with an ?- and/or ?-glucan decomposing enzyme such as amylase and cellulose and in which non-rubber components are subjected to suited enzyme treatment, and it provides natural rubber which is maintained in physical properties such as revelation of strain induced crystallization, an accelerating effect, an antioxidant effect and a vulcanization-accelerating effect and which is improved particularly in an abrasion resistance and a low hysteresis loss property, a production process for the same and a rubber composition and a tire using such natural rubber.

Abstract: The natural rubber latex of the present invention in which phospholipid contained in the latex is decomposed, particularly the natural rubber latex in which it is decomposed by enzyme treatment with lipase and/or phospholipase at a temperature of 70° C. or lower is excellent in a processability, and in the natural rubber thereof and the rubber composition using the same, the physical properties such as an anti-aging characteristic, a tensile strength and an abrasion resistance are sufficiently maintained. Accordingly, the natural rubber of the present invention can be used as an excellent member for a tire.

Abstract: This invention provides a method for producing a modified natural rubber masterbatch, which comprises the step of mixing a modified natural rubber latex, which is formed by adding a polar group-containing monomer to a natural rubber latex to graft-polymerize the polar group-containing monomer onto a natural rubber molecule in the natural rubber latex, with a slurry solution formed by previously dispersing a filler into water, and a modified natural rubber masterbatch produced by the method and capable of highly improving a low loss factor, a wear resistance and fracture characteristics of a rubber composition.

Abstract: A process for producing a conjugated diene-based polymer which comprises, in the first modification, modifying a conjugated diene-based polymer having active chain ends, which is obtained by polymerizing a diene-based monomer singly or with other monomers and has a content of a cis-1,4 unit of 75% by mole or greater in the conjugated diene portion of the main chain, by reacting the active chain ends with a hydrocarbyloxysilane compound and reacting the modified polymer with a specific compound such as a hydrocarbyloxysilane compound, and a rubber composition containing the polymer modified in accordance with the above process and, preferably, 10 to 100 parts by weight of silica and/or carbon black per 100 parts by weight of the rubber component containing the modified polymer, are provided. The rubber composition containing silica and/or carbon black exhibits improved fracture properties, abrasion resistance, low heat buildup property and excellent workability.

Abstract: This invention provides a modified natural rubber latex formed by charging a polar group-containing mercapto compound into a natural rubber latex to add the polar group-containing mercapto compound to a natural rubber molecule in the natural rubber latex, a modified natural rubber formed by coagulating and drying the modified natural rubber latex, and the rubber composition using the modified natural rubber and being excellent in the low loss factor, wear resistance and fracture characteristics.

Abstract: Natural rubber obtained by a deproteinizing treatment of a natural rubber latex and has a total nitrogen content adjusted in the range of 0.12 to 0.30% by weight and a rubber composition and a pneumatic tire using the natural rubber. The processability of natural rubber can be improved without adverse effects on the physical properties proper to natural rubber. The rubber composition exhibits an improved low hysteresis loss property and improved abrasion resistance and can be advantageously used for the tire case members and the tire tread of pneumatic tires.

Abstract: This invention provides a method for producing a modified natural rubber masterbatch, which comprises the step of mixing a modified natural rubber latex, which is formed by adding a polar group-containing monomer to a natural rubber latex to graft-polymerize the polar group-containing monomer onto a natural rubber molecule in the natural rubber latex, with a slurry solution formed by previously dispersing a filler into water, and a modified natural rubber masterbatch produced by the method and capable of highly improving a low loss factor, a wear resistance and fracture characteristics of a rubber composition.

Abstract: Provided is a process for producing a modified polymer, characterized by carrying out primary modification in which a hydrocarbyloxysilane compound is reacted with the active site of a polymer having an active site of an organic metal type in a molecule and then carrying out secondary modification in which the hydrocarbyloxysilane compound is further reacted therewith. This makes it possible to provide a modified polymer which enhances interactions with silica and carbon black when used for both of silica-blended and carbon black-blended rubber compositions and which elevates the fracture characteristic, the abrasion resistance and the low heat buildup property at the same time and can exhibit a good workability.

Abstract: Provided is a process for producing a modified polymer, characterized by carrying out primary modification in which a hydrocarbyloxysilane compound is reacted with the active site of a polymer having an active site of an organic metal type in a molecule and then carrying out secondary modification in which the hydrocarbyloxysilane compound is further reacted therewith. This makes it possible to provide a modified polymer which enhances interactions with silica and carbon black when used for both of silica-blended and carbon black-blended rubber compositions and which elevates the fracture characteristic, the abrasion resistance and the low heat buildup property at the same time and can exhibit a good workability.

Abstract: The present invention provides natural rubber latex in which glucans being polysaccharides contained in the latex are decomposed by treating the natural rubber latex with an ?- and/or ?-glucan decomposing enzyme such as amylase and cellulose and in which non-rubber components are subjected to suited enzyme treatment, and it provides natural rubber which is maintained in physical properties such as revelation of strain induced crystallization, an accelerating effect, an antioxidant effect and a vulcanization-accelerating effect and which is improved particularly in an abrasion resistance and a low hysteresis loss property, a production process for the same and a rubber composition and a tire using such natural rubber.

Abstract: The natural rubber latex of the present invention in which phospholipid contained in the latex is decomposed, particularly the natural rubber latex in which it is decomposed by enzyme treatment with lipase and/or phospholipase at a temperature of 70° C. or lower is excellent in a processability, and in the natural rubber thereof and the rubber composition using the same, the physical properties such as an anti-aging characteristic, a tensile strength and an abrasion resistance are sufficiently maintained. Accordingly, the natural rubber of the present invention can be used as an excellent member for a tire.

Abstract: Natural rubber obtained by a deproteinizing treatment of a natural rubber latex and has a total nitrogen content adjusted in the range of 0.12 to 0.30% by weight and a rubber composition and a pneumatic tire using the natural rubber. The processability of natural rubber can be improved without adverse effects on the physical properties proper to natural rubber. The rubber composition exhibits an improved low hysteresis loss property and improved abrasion resistance and can be advantageously used for the tire case members and the tire tread of pneumatic tires.

Abstract: A process for producing a conjugated diene-based polymer which comprises, in the first modification, modifying a conjugated diene-based polymer having active chain ends, which is obtained by polymerizing a diene-based monomer singly or with other monomers and has a content of a cis-1,4 unit of 75% by mole or greater in the conjugated diene portion of the main chain, by reacting the active chain ends with a hydrocarbyloxysilane compound and reacting the modified polymer with a specific compound such as a hydrocarbyloxysilane compound, and a rubber composition containing the polymer modified in accordance with the above process and, preferably, 10 to 100 parts by weight of silica and/or carbon black per 100 parts by weight of the rubber component containing the modified polymer, are provided. The rubber composition containing silica and/or carbon black exhibits improved fracture properties, abrasion resistance, low heat buildup property and excellent workability.

Abstract: Provided is a process for producing a modified polymer, characterized by carrying out primary modification in which a hydrocarbyloxysilane compound is reacted with the active site of a polymer having an active site of an organic metal type in a molecule and then carrying out secondary modification in which the hydrocarbyloxysilane compound is further reacted therewith. This makes it possible to provide a modified polymer which enhances interactions with silica and carbon black when used for both of silica-blended and carbon black-blended rubber compositions and which elevates the fracture characteristic, the abrasion resistance and the low heat buildup property at the same time and can exhibit a good workability.

Abstract: It is an object of the present invention to provide a rubber composition which can give a vulcanized rubber with low rolling resistance and excellent wet skid resistance and wear resistance, which is particularly useful for automobile tire treads and the like. The rubber composition of the invention comprises (1) a crosslinked rubber particle containing, as repeating units, 40 to 79.99% by weight of a monomer unit formed by a conjugated diene such as 1,3-butadiene, 20 to 50% by weight of a monomer unit formed by an aromatic vinyl monomer such as styrene and 0.01 to 10% by weight of a monomer unit formed by a monomer having at least two polymerizable unsaturated groups such as divinylbenzene, and (2) a conjugated diene/aromatic vinyl copolymeric rubber whose vinyl content of the conjugated diene monomer unit is 10 to 30% and whose 1,4-trans bond content is more than 55%, such as styrene-butadiene copolymeric rubber.

Abstract: It is an object of the present invention to provide a rubber composition which can give a vulcanized rubber with low rolling resistance and excellent wet skid resistance and wear resistance, which is particularly useful for automobile tire treads and the like.

Abstract: A control apparatus for an electric vehicle is provided, which is capable of reducing the weight of the electric vehicle and preventing the inverter circuit from overheating. When the vehicle stops on an uphill due to stalling, the control unit 30 starts counting the time over which current is supplied through the same IGBT element. When the count value reaches a value corresponding to the time at which the IGBT 40 starts generating heat, the control unit 30 outputs a control signal to reduce the motor driving current to the IPM 20. The rotation sensor 60 detects the rotational position when the motor rotates in the reverse direction, while the reduction of the motor driving current reduces the driving power of the motor. Based on the detection of the rotational position, the control unit 30 performs switching of the phase of the IGBT 40, and when the normal current supply phase is connected, the motor driving current which drives the motor is increased.

Abstract: A control device for an alternating current motor includes: a target current generating unit which generates a current order value, based on a torque order, as a d-axis target current and a q-axis target current on dq coordinates; a current detection device which detects an alternating current supplied to each phase of a polyphase alternating current motor; a coordinate transforming unit which transforms the alternating current detected by the current detection device into a d-axis current and a q-axis current on the dq coordinates; and a vector control unit which carries out a current feedback control so that the d-axis current follows up the d-axis target current and the q-axis current follows up the q-axis target current.