Sumitomo Rubber Industries Limited

Shin-etsu Chemical Co., Ltd.

Hiroyuki Kishimoto

Ryo Mashita

Fusae Kaneko

Ryota Kitago

Kiyoshige Muraoka

Tomomi Masui

Masatoshi Yokota

Munenao Hirokami

Takahiro Mabuchi

Ryuichi Tokimune

Tetsuro Yamada

Seigou Sakagami

Soh Ishino

Kazuyuki Nishioka

Noriko Yagi

Isamu Tsumori

Shinichi Ueno

Tsuyoshi Tsuchida

Kohei Takemura

Akira Minakoshi

Hiroshi Jinnai

Marina Kotani

Hidehiko Dohi

Yasumasa Bito

Hirofumi Nakamae

Takeshi Kaneko

A performance evaluation method for elastic material including rubber or elastomer, the method includes a step of applying a strain to a test piece made of the elastic material to form at least one void inside the test piece, a step of obtaining projected images of the test piece by irradiating the test piece with X-rays at a plurality of times after the at least one void is formed, and a step of obtaining a volume change of the at least one void between the plurality of times based on the projected images, as one of indexes of performance.

Performance evaluation method for elastic material

A pneumatic tire includes bead cores, a carcass ply, an inner liner and the tread, and the crosslinked rubber composition, of the present invention, wherein the tread and the crosslinked rubber composition have a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5 or less at elongation by an applied stress of 3.0 MPa and a ratio of 40% by mass or more of a component having a weight-average molecular weight of not less than 1,000,000 in a molecular weight distribution measured by gel permeation chromatography are excellent in abrasion resistance.

Pneumatic tire and crosslinked rubber composition

The pneumatic tire of the present invention characterized by comprising: bead cores, a carcass ply, an inner liner and a tread having a volume of the low density region of 35% or more, at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5% or less at elongation by an applied stress of 3.0 MPa and a glass transition temperature of &#x2212;20&#xb0; C. or lower, and the crosslinked rubber composition of the present invention having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5 or less at elongation by an applied stress of 3.0 MPa and a glass transition temperature of &#x2212;20&#xb0; C. or lower are excellent in abrasion resistance.

A pneumatic tire includes bead cores, a carcass ply, an inner liner, and a tread having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5% or less at elongation by an applied stress of 3.0 MPa and a hardness of 65 or more and the crosslinked rubber composition of the present invention having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5 or less at elongation by an applied stress of 3.0 MPa and a hardness of 65 or more are excellent in abrasion resistance.

Provided is a method for estimating abrasion resistance and fracture resistance by highly accurately analyzing aggregation (dispersion) of sulfur-based materials in polymer composite materials. The present invention relates to a method for estimating abrasion resistance and fracture resistance, the method including: irradiating a polymer composite material containing at least one sulfur-based material selected from the group consisting of sulfur and sulfur compounds with high intensity X-rays; measuring X-ray absorption of a measurement region of the polymer composite material while varying the energy of the X-rays; calculating areas of spots having a high sulfur concentration equal to or greater than a predetermined level in a two-dimensional mapping image of sulfur concentration of the measurement region; and estimating abrasion resistance and fracture resistance based on the areas.

Method for estimating abrasion resistance and fracture resistance

The pneumatic tire characterized by comprising the tread and the crosslinked rubber composition, of the present invention, wherein the tread and the crosslinked rubber composition comprise two or more kinds of rubber components and a filler and have a volume of the low density region of 35% or more, a volume of the void portion of 7.5 or less and a filler distribution D represented by the following formula (I) of 2.0 or less are excellent in abrasion resistance.=()/()&#x2003;&#x2003;(I) In the formula (I),

The pneumatic tire of the present invention characterized by comprising: bead cores, a carcass ply, an inner liner disposed at an inner side than the carcass ply in a direction of a tire diameter, and a tread disposed at an outer side than the carcass ply in a direction of a tire diameter and having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5% or less at elongation by an applied stress of 3.0 MPa and a filler dispersibility index &#x394;G* shown by the following equation (I) of 3 or less and the crosslinked rubber composition having a volume of the low density region of 35% or more at elongation by an applied stress of 1.5 MPa, a volume of the void portion of 7.5 or less at elongation by an applied stress of 3.0 MPa and a filler dispersibility index &#x394;G* shown by the following equation (I) of 3 or less are excellent in abrasion resistance.&#x394;*=(*(4%)&#x2212;*(256%))/*(256%)&#x2003;&#x2003;(I)In the equation (I), G* (n %) indicates a shear modulus when an n % strain is applied.

Provided are a rubber composition for tires which achieves both abrasion resistance and processability while maintaining fuel economy, and a pneumatic tire including the rubber composition. A rubber composition for tires, containing an organosilicon compound represented by the average compositional formula (I) below having a ratio of the number of sulfur atoms to the number of silicon atoms of 1.0 to 1.5, wherein x represents the average number of sulfur atoms; m represents an integer of 6 to 12; and Rto Rare the same or different and each represent a C1-C6 alkyl or alkoxy group, at least one of Rto Rand at least one of Rto Rare the alkoxy groups, and two or more of the alkyl or alkoxy groups for Rto Rmay be joined to form a ring.

Rubber composition for tires and pneumatic tire

A method for observing deformation of an elastic material including rubber or elastomer, includes a first step of capturing projection images of at least a part of the elastic material from directions perpendicular to an arbitrary axis of the elastic material and a second step of constructing a three-dimensional image of the elastic material from the projection images. The first step includes deforming the elastic material in predetermined constant cycles, outputting capture signals at the same time points of the predetermined constant cycles, and capturing the projection images based on the respective capture signals.

Method for observing deformation of elastic material and apparatus for capturing projection image of elastic material

A method for evaluating the crosslink concentration in a crosslinked rubber is provided. The present invention relates to a method for evaluating the crosslink concentration in a crosslinked rubber by small-angle X-ray scattering or small-angle neutron scattering using measurement samples prepared by swelling the crosslinked rubber to different degrees of swelling.

Method for evaluating crosslink concentration in crosslinked rubber

The present invention provides deterioration analysis method which allows a detailed analysis of deterioration, especially deterioration of surface conditions, of a polymer material. The present invention relates to a deterioration analysis method, including irradiating a polymer material with high intensity X-rays, and measuring X-ray absorption while varying the energy of the X-rays, to analyze deterioration of the polymer.

Deterioration analysis method

A computerized simulation method for evaluating dispersion of fillers in a high polymer material includes a step of defining a filler model comprising at least one particle, a step of defining a polymer model comprising a plurality of particles each having a first potential with respect to the particle of the filler model, a step of performing a molecular dynamics calculation of the filler model and the polymer model placed in a predetermined virtual space on the computer, and a step of observing the dispersion of the filler model from data obtained in the molecular dynamics calculation. The polymer model further includes at least one modified basal particle having a second potential with respect to the particle of the filler model, and the second potential differs from the first potential.

Simulation method for high polymer material

Provided is an evaluation method that provides detailed information on the crosslink densities in sulfur-containing polymer composite materials. The present invention relates to a method of measuring crosslink densities in a sulfur-containing polymer composite material, the method including: a measurement step of irradiating the sulfur-containing polymer composite material with high intensity X-rays and measuring an X-ray absorption spectrum of the composite material while varying the energy of the X-rays; a visualization step of determining the three-dimensional structure of sulfur atoms in the sulfur-containing polymer composite material by the reverse Monte Carlo method from the X-ray absorption spectrum; and a calculation step of calculating, from the three-dimensional structure of sulfur atoms, a crosslink density for each number of sulfur atoms bonded.

Method of measuring crosslink densities in sulfur-containing polymer composite material

The present invention provides a method of deterioration analysis that enables detailed analysis of the deterioration, especially of the surface, of a polymer material containing at least two diene polymers. The present invention relates to a method of deterioration analysis including: irradiating a polymer material containing at least two diene polymers with high intensity x-rays; and measuring x-ray absorption while varying the energy of the x-rays, to analyze the deterioration of each diene polymer.

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Kobe, Japan

Hiroyuki Kishimoto