Abstract: A method of manufacturing a pneumatic tire includes forming a green tire. Forming the green tire includes: a first step of forming a first belt portion by winding a first belt on an outer peripheral surface of an inner liner and, thereafter, forming a second belt portion by winding a second belt on the first belt portion thus acquiring a belt layer; and a second step of acquiring a reinforcing layer by winding a reinforcing belt on the second belt portion. The second step includes: a first parallel winding treatment where the reinforcing belt is wound one turn on a first circumference; a spiral winding treatment where the reinforcing belt is spirally wound in a tire width direction; and a second parallel winding treatment where the reinforcing belt is wound on a second circumference within a range of from 240°±30° with one turn set to 360°.

Abstract: A pneumatic tire has a carcass layer, a side wall rubber which forms an outer surface of a side wall portion, and a rim strip rubber which forms an outer surface of a bead portion. The rim strip rubber extends in a tire radial direction between the carcass layer and the side wall rubber. A height of the rim strip rubber on the basis of an outer diameter position of a bead core buries in the bead portion is equal to or more than 70% of a height of a tire outer diameter position. A thickness Tw of the rim strip rubber at the tire maximum width position is smaller than the maximum thickness Tm of the rim strip rubber which is closer to an outer side in the tire radial direction than the tire maximum width position.

Abstract: Provided is a tire vulcanization mold which includes a sector mold configured to mold a tread portion; and a pair of upper and lower side plates positioned on an inner diameter side of the sector mold and configured to mold side wall portions, the sector mold and the pair of upper and lower side plates being configured to engage with each other by fitting engagement by way of fitting portions which opposedly face each other in a radial direction. At least either one of the sector mold and the side plate has: a recessed portion extending from each fitting surface in a tire radial direction and indented outward in a tire width direction; and a saw cut groove having a groove shape extending in a tire radial direction along at least one of an edge portion and a corner portion of the recessed portion and communicating with the fitting surface.

Abstract: A pneumatic tire has a rim strip rubber. A height of the rim strip rubber on the basis of an outer diameter position of a bead core is equal to or more than 70% of a height of a tire outer diameter position. An upper end of a side reinforcing layer is arranged closer to an outer side radially than an upper end of a bead filler. A distance from a tire maximum width position to the upper end of the side reinforcing layer is equal to or less than 5 mm. The maximum thickness Tw of the rim strip rubber between the upper end of the bead filler and the upper end of the side reinforcing layer is greater than the maximum thickness Tm of the rim strip rubber closer to the outer side radially than the upper end of the side reinforcing layer.

Abstract: A plurality of rollers each having a rotary shaft parallel to a rotary shaft of a rotary support body are moved toward a tire member in a synchronized manner so that the tire member is disposed between the plurality of rollers and the rotary support body while the rollers are brought into contact with at least one of the rotary support body and the tire member supported by the rotating rotary support body and the rotary support body is contracted in a state where the tire member is disposed between the plurality of rollers and the rotary support body so that the tire member is delivered from the rotary support body to the plurality of rollers.

Abstract: A method for producing a wet rubber masterbatch, comprising a step (I) of adding, at the time of dispersing the filler into the dispersing solvent, at least one portion of the synthetic styrene butadiene rubber latex solution into the dispersing solvent to produce a slurry solution comprising the filler to which rubber latex particles adhere, a step (II) of mixing the slurry solution with the rest of the rubber latex solution to produce a filler-containing rubber latex solution in which the rubber latex particles adhere to the filler, a step (III) of solidifying the filler-containing rubber latex solution, in which the rubber latex particles adhere to the filler, to produce a rubber solidified product, and a step (IV) of dehydrating and drying the rubber solidified product, wherein in anyone of the steps (I) to (IV), the rubber powder is mixed with the wet-rubber-masterbatch-producing phase present in the step.

Abstract: A problem which is addressed is the provision of a method for manufacturing a wet rubber masterbatch that will serve as raw material for vulcanized rubber which excels in fatigue resistance, ability to achieve reduced heat generation, and tensile characteristics. A wet rubber masterbatch is manufactured by means of a method comprising an operation in which a latex that has magnesium present therein in an amount which is not greater than 150 ppm is prepared; an operation in which a liquid mixture is made; and an operation in which the liquid mixture is coagulated to obtain a coagulum. The latex comprises rubber particles for which the 90 vol % particle diameter is not greater than 2 ?m. The operation in which the liquid mixture is made comprises a step in which the latex and a dispersion solvent are mixed together.

Abstract: A problem which is addressed is the provision of a method for manufacturing a wet rubber masterbatch and so forth permitting improvement in fatigue resistance without causing worsening in ability to achieve reduced heat generation. Wet rubber masterbatch and so forth are manufactured by means of a method comprising an operation in which a latex that comprises rubber particles for which 90 vol % particle diameter is not greater than 2 ?m and that has magnesium present therein in an amount which is not greater than 150 ppm is prepared.

Abstract: A tire has a cap rubber, a base rubber, and a conductive rubber. The cap rubber which is formed by a nonconductive rubber and constructs a ground surface. The base rubber which is provided in an inner side in a tire radial direction of the cap rubber. The conductive rubber which extends in a thickness direction of the cap rubber, passes an inner portion of the cap rubber and gets to a bottom surface of the base rubber from the ground surface. An interface end which is in contact with the conductive rubber in an interface between the cap rubber and the base rubber comes down to an inner side in a radial direction in comparison with an interface in a periphery of the interface end.

Abstract: A method for forming a cylindrical rubber member includes bringing a die 11 close to a forming drum 2, forming a winding start portion S1 by extruding a rubber S and simultaneously starting to rotate the forming drum 2 to gradually increase an extruding amount to an amount Q1 and gradually increase a distance between the die 11 and the forming drum 2 to a distance D2 corresponding to a desired thickness of the cylindrical rubber member, winding the rubber S by maintaining the extruding amount at the amount Q1, and maintaining the distance between the die 11 and the forming drum 2 at the distance D2, and forming a winding end portion S2 on the winding start portion S1 by maintaining the distance between the die 11 and the forming drum 2 at the distance D2 and gradually reducing the extruding amount from the amount Q1.

Abstract: A tire vulcanization mold including a sector mold divided into a plurality of pieces along a circumferential direction of a green tire, the sector mold configured to vulcanization mold a tread portion of the green tire into a predetermined shape, and an upper mold and a lower mold disposed on both sides of the green tire so as to sandwich the green tire therebetween in an axial direction of the green tire, the upper mold and lower mold configured to vulcanization mold a side portion of the green tire into a predetermined shape. The sector mold has a weir portion in a vicinity of a fitting portion between the sector mold, and the upper mold and the lower mold.

Abstract: There are provided a rubber masterbatch which can give a vulcanized rubber having a low hysteresis loss while having a low electrical resistance (low volume electrical resistance value); and a method for producing the rubber masterbatch. The rubber master-batch is a rubber masterbatch including a diene rubber, a carbon nanotube, and a silane coupling agent, and the carbon nanotube shows a weight loss proportion of 10 to 30% by weight in a range from 200 to 600° C. in a thermogravimetry of the carbon nanotube.

Abstract: A junction with an antivibration base body joined to its outer periphery is equipped with a chamfer portion where a corner connecting a flange portion with the junction is removed, a base portion connected to the chamfer portion in the axial direction, and an end portion connected to the base portion in the axial direction. At the junction, a first projection plane made by projecting at least the end portion in a first direction orthogonal to the axis is set to be smaller in area than a second projection plane made by projecting at least the end portion in a second direction orthogonal to the axis and the first direction.

Abstract: A junction with an antivibration base body joined to its outer periphery is equipped with a chamfer portion where a corner connecting a flange portion to the junction is removed, a base portion connected to the chamfer portion in the axial direction, and an end portion connected to the base portion in the axial direction. At the base portion, a first projection plane made by being projected in a first direction orthogonal to the axis is substantially the same in area as a second projection plane made by being projected in a second direction orthogonal to the axis and the first direction. At the end portion, the area of the second projection plane is set to be larger than the area of the first projection plane.

Abstract: A tire includes a tread rubber which is formed by a plurality kinds of rubber having different elastic modulus, the tread rubber is provided with peripheral joint portions where the plurality kinds of rubber having the different elastic modulus is joined in a tire peripheral direction, and a ground end portion of an outside surface of the tread rubber in a tire width direction is formed by the rubber having the greatest elastic modulus among the plurality kinds of rubber constructing the peripheral joint portions.

Abstract: A pneumatic tire includes a sidewall portion extending in a tire radial-direction. The sidewall portion includes a plurality of projecting portions projecting in a tire width-direction, and at least one reinforcing portion which is at least partly different in a projecting amount from a projecting amount of the projecting portions at the same position in the tire radial-direction, and is connected to the projecting portion in a tire circumferential-direction.

Abstract: The purpose of the present invention is to provide: a thermally responsive liquid-crystal polyurethane elastomer which is capable of being industrially continuously molded, and which is liquid crystal and has rubber elasticity at low temperatures (in the vicinity of room temperature); and a production method and a starting material therefor. This liquid-crystal urethane compound is obtained by reacting a mesogenic group-containing compound having at least active hydrogen groups, an alkylene oxide and/or a styrene oxide, and a diisocyanate compound.

Abstract: A rubber composition, comprising one or more rubber components, and an oil of a plant in the family Euphorbiaceae in an amount of 1 to 60 parts by mass for the entire amount of the rubber component(s) when the entire amount is regarded as 100 parts by mass. It is preferred that the plant oil is an oil originating from an inedible resource and comprising an unsaturated fatty acid in a proportion of 50% by mass or more of the plant oil.

Abstract: A rubber composition, comprising a rubber component which includes a diene rubber, a filler, and a powdery rubber, and further comprising an aromatic polyoxyethylene derivative. When the entire amount of the rubber component is regarded as 100 parts by mass, the aromatic polyoxyethylene derivative is preferably included in an amount of 0.1 to 10 parts by mass.

Abstract: A tire vulcanization mold including a sector mold divided into a plurality of pieces along a circumferential direction of a green tire, the sector mold configured to vulcanization mold a tread portion of the green tire into a predetermined shape, and an upper mold and a lower mold disposed on both sides of the green tire so as to sandwich the green tire therebetween in an axial direction of the green tire, the upper mold and the lower mold configured to vulcanization mold a side portion of the green tire into a predetermined shape. The sector mold has a relief groove in a vicinity of a fitting portion between the sector mold, and the upper mold and the lower mold.