Abstract: Provided is a self-restoring macromolecular material that not only has excellent stress relaxation but that can also be easily restored to its original state, even when damaged or severed. Also provided is a method for producing the self-restoring macromolecular material. The self-restoring macromolecular material contains a crosslinked structure that is formed by crosslinking a polymer containing at least a polyrotaxane molecule. The polyrotaxane molecule is formed so as to include a cyclic molecule 21 and a linear molecule that passes through an opening 21a of the cyclic molecule. The crosslinked structure 1 is crosslinked via a reversible bond between the cyclic molecule of the polyrotaxane molecule and a polymer molecule other than the polyrotaxane molecule.

Abstract: Provided is a rubber composition for tires which contains: a rubber component including an aromatic vinyl-conjugated diene copolymer that contains aromatic vinyl units and conjugated diene units, a high-cis polybutadiene rubber having a cis microstructure content of 95% by mass or higher, and an isoprene-based rubber; carbon black; and a silica having a N2SA of 40 m2/g or more, the copolymer containing at least 80% of isolated aromatic vinyl units based on the total aromatic vinyl units, the copolymer having a ?Tg of more than 10° C. but less than 20° C. as determined by DSC, the rubber component including, based on 100% by mass thereof, 1-45% by mass of the copolymer, 20-64% by mass of the high-cis polybutadiene rubber, and 35-60% by mass of the isoprene-based rubber, the rubber composition containing 5 parts by mass or more of the silica per 100 parts by mass of the rubber component.

Abstract: Provided is a self-restoring macromolecular material that not only has excellent stress relaxation but that can also be easily restored to its original state, even when damaged or severed. Also provided is a method for producing the self-restoring macromolecular material. The self-restoring macromolecular material contains a crosslinked structure that is formed by crosslinking a polymer containing at least a polyrotaxane molecule. The polyrotaxane molecule is formed so as to include a cyclic molecule 21 and a linear molecule that passes through an opening 21a of the cyclic molecule. The crosslinked structure 1 is crosslinked via a reversible bond between the cyclic molecule of the polyrotaxane molecule and a polymer molecule other than the polyrotaxane molecule.