| abstract |
A thermoplastic elastomer composition dynamically vulcanized to a gelation rate of 50 to 95% which is superior in heat resistance and durability while maintaining flexibility and superior in air permeation preventive property which can be efficiently used as, for example, a pneumatic tire as an air permeation preventive layer. In particular, a thermoplastic elastomer composition having a reduced particle size of the domain rubber is produced by a material having a high rubber ratio by mixing a composition (C) mixed under conditions of a ratio of melt viscosities of the rubber composition (A)/resin (B) of 0.8 to 1.2 and the formula (φ A /φ B )×(η B /η A )< 1.0 under conditions of a ratio of melt viscosities of the rubber composition (D)/composition (C) of 0.8 to 1.2 and the formula (φ D /φ C )×(η C /η D )< 2.0 , wherein φ A : volume fraction of rubber composition (A), φ B : volume fraction of resin (B), η A : melt viscosity of rubber composition (A), η B : melt viscosity of resin (B), φ C : volume fraction of composition (C), φ D : volume fraction of rubber composition (D), η C : melt viscosity of composition (C), η D : melt viscosity of rubber composition (D). Further, a thermoplastic elastomer composition having an elastomer composition (A) as a dispersion phase and a thermoplastic resin composition (B) as a matrix and having a thermoplastic resin composition composed of a blend of at least two thermoplastic resins. |