Abstract: To provide an analysis method that can analyze a crystal structure, a crystal morphology, a crystal distribution of a rubber material in stretching even in a local portion of the rubber material. The present disclosure relates to a method of analyzing a crystal structure, a crystal morphology, or a crystal distribution of a rubber material in stretching using a nanodiffraction imaging technique that analyzes an electron diffraction pattern acquired by scanning electron beams converged to a diameter of 100 nm or less on a surface of the rubber material while a behavior of stretching deformation of the rubber material and/or a state of the rubber material in stretching are observed using a transmission electron microscope.

Abstract: A chemical bond evaluation method capable of directly evaluating the presence or absence of a chemical bond between silica and a silane coupling agent includes performing multidimensional solid-state nuclear magnetic resonance (NMR) analysis on a rubber composition comprising a rubber component, a silica, and a silane coupling agent; and evaluating the presence or absence of a chemical bond between silica and the silane coupling agent in the rubber composition containing a rubber component, the silica, and the silane coupling agent.

Abstract: The present disclosure provides a chemical bond evaluation method capable of directly evaluating the presence or absence of a chemical bond between silica and a silane coupling agent. Included is a chemical bond evaluation method including evaluating the presence or absence of a chemical bond between silica and a silane coupling agent in a rubber composition containing a rubber component, the silica, and the silane coupling agent.

Abstract: The present invention provides a rubber composition for tires which provides improved abrasion resistance, and a pneumatic tire containing the rubber composition. The present invention relates to a rubber composition for tires containing a rubber component including at least 80% by mass in total of at least one of an isoprene-based rubber, a polybutadiene rubber, or a styrene-butadiene rubber, the rubber composition containing, per 100 parts by mass of the rubber component, 3 to 250 parts by mass of a reinforcing filler and 0.2 to 10 parts by mass of a specific tetrazine compound.

Abstract: The invention provides natural rubbers having improved processability and/or abrasion resistance, rubber compositions containing the natural rubbers, and pneumatic tires formed from the rubber compositions. The invention relates to a natural rubber which shows a 1H-NMR spectrum where the sum of peak intensities at about 4.17, 3.94, 3.84, 3.73, 3.50, and 3.41 ppm, normalized to 10,000 for the peak intensity at about 5.11 ppm, is 8.0 or less.

Abstract: The invention provides natural rubbers having improved processability and/or abrasion resistance, rubber compositions containing the natural rubbers, and pneumatic tires formed from the rubber compositions. The invention relates to a natural rubber which shows a 1H-NMR spectrum where the sum of peak intensities at about 4.17, 3.94, 3.84, 3.73, 3.50, and 3.41 ppm, normalized to 10,000 for the peak intensity at about 5.11 ppm, is 8.0 or less.

Abstract: The present invention provides a rubber composition for tires which provides improved abrasion resistance, and a pneumatic tire containing the rubber composition. The present invention relates to a rubber composition for tires containing a rubber component including at least 80% by mass in total of at least one of an isoprene-based rubber, a polybutadiene rubber, or a styrene-butadiene rubber, the rubber composition containing, per 100 parts by mass of the rubber component, 3 to 250 parts by mass of a reinforcing filler and 0.2 to 10 parts by mass of a specific tetrazine compound.