Abstract: An ultrasonic inspection device includes: a longitudinal ultrasonic sensor configured to emit and receive a longitudinal ultrasonic wave; and an ultrasonic transducer unit made of metal and having the shape of a polyhedron. The ultrasonic transducer unit includes: an output surface configured to be disposed facing an object to be inspected; an input surface on which the longitudinal ultrasonic sensor is disposed; and a conversion surface configured to, when the longitudinal ultrasonic wave input through the input surface is reflected by the conversion surface, convert the longitudinal ultrasonic wave into a transverse ultrasonic wave such that the transverse ultrasonic wave propagates toward the output surface, the conversion surface being tilted at a predetermined angle with respect to an in-plane direction of the output surface. Thermal conductivity of the ultrasonic transducer unit is lower than thermal conductivity of the object to be inspected.

Abstract: After step (I) of kneading a diene rubber and a carbon black to be mixed with each other, and then discharging the resultant mixture containing the diene rubber and the carbon black from an internal mixer, step (II) of kneading the mixture again in the internal mixer to crush a re-aggregate of the carbon black in the mixture, and step (III) of charging the dihydrazide compound into the internal mixer, and kneading the mixture and the dihydrazide compound to be mixed with each other are carried out. The period of step (II) for the kneading is 15 seconds or longer, and the rotating speed of the stirring rotor of the internal mixer is 35 rpm or more. The period of step (III) for the kneading is 40 seconds or longer, and the rotating speed of the stirring rotor of the internal mixer is from 15 to 25 rpm.

Abstract: After step (I) of kneading a diene rubber and a carbon black to be mixed with each other, and then discharging the resultant mixture containing the diene rubber and the carbon black from an internal mixer, step (II) of kneading the mixture again in the internal mixer to crush a re-aggregate of the carbon black in the mixture, and step (III) of charging the dihydrazide compound into the internal mixer, and kneading the mixture and the dihydrazide compound to be mixed with each other are carried out. The period of step (II) for the kneading is 15 seconds or longer, and the rotating speed of the stirring rotor of the internal mixer is 35 rpm or more. The period of step (III) for the kneading is 40 seconds or longer, and the rotating speed of the stirring rotor of the internal mixer is from 15 to 25 rpm.

Abstract: A method for manufacturing a tire member, that improves various performances such as abrasion resistance, tear strength, fatigue resistance and the like of the tire member in good balance is provided. The method includes a step (A) for mixing at least a rubber component, a filler and a thiosulfuric acid compound containing an amino group, and a step (B) for mixing the mixture obtained by the step (A), a sulfur component, and a vulcanization accelerator, wherein the thiosulfuric acid compound containing an amino group is added in an amount of 0.2 parts by mass or more to 100 parts by mass of the rubber component in the step (A), and a temperature of the mixture during mixing is maintained within a range of from 145 to 170° C. for 20 seconds or more in the step (A).

Abstract: An ultrasonic measurement waveguide rod which is easy to manufacture and is capable of preventing a noise echo. An ultrasonic flaw detection waveguide rod 2 is arranged with a probe on one axial end thereof and a contact surface to be brought into contact with a test piece on the other end thereof. The cross-sectional shape of the rod 2 perpendicular to the axial direction is a polygon having sides any one (41A) of which is not parallel to any of the other sides 41B, 41C, 41D. Since at least a pair of the sides 41A, 41C opposed to each other are not parallel to each other, an ultrasonic wave P is allowed to reflect off outer surfaces making up the nonparallel sides 41A, 41C, enabling the ultrasonic wave P to be prevented from returning to the probe 3 as a noise echo. For example, the ultrasonic wave component reflected perpendicularly by one outer surface is reflected by the opposite outer surface and travels toward the outer surface having the side 41D. Hence, an echo or a noise hardly returns to the probe.

Abstract: An ultrasonic measurement waveguide rod which is easy to manufacture and is capable of preventing a noise echo. An ultrasonic flaw detection waveguide rod 2 is arranged with a probe on one axial end thereof and a contact surface to be brought into contact with a test piece on the other end thereof. The cross-sectional shape of the rod 2 perpendicular to the axial direction is a polygon having sides any one (41A) of which is not parallel to any of the other sides 41B, 41C, 41D. Since at least a pair of the sides 41A, 41C opposed to each other are not parallel to each other, an ultrasonic wave P is allowed to reflect off outer surfaces making up the nonparallel sides 41A, 41C, enabling the ultrasonic wave P to be prevented from returning to the probe 3 as a noise echo. For example, the ultrasonic wave component reflected perpendicularly by one outer surface is reflected by the opposite outer surface and travels toward the outer surface having the side 41D. Hence, an echo or a noise hardly returns to the probe.

Abstract: A rubber composition for tire, which combines low heat build-up properties and breakage property, reduces fuel consumption of a tire, and has excellent good processability is provided. The rubber composition for tire is obtained by blending sulfur and caprolactam disulfide with a diene rubber component to obtain a pre-mixture which does not contain a reinforcing filler and a vulcanization accelerator, and blending and mixing a reinforcing filler and a vulcanization accelerator with the pre-mixture in a post-mixing step.

Abstract: A rubber composition for tire, which combines low heat build-up properties and breakage property in high level, reduces fuel consumption of a tire, and has excellent durability and good processability is provided. The rubber composition for tire is obtained by kneading a diene rubber component, sulfur and a pyrithione metal salt to obtain a rubber mixture, and adding and kneading a vulcanization accelerator in a post-mixing step using the rubber mixture. The pyrithione metal salt can use a compound represented by the following formula (1): wherein n is 1 or 2, and M represents Zn, Cu, Na or Ca.