Patent ID: 8801884

Claim:
A method of forming a tire innerliner having a cylindrical inner rubber layer and a cylindrical film formed of a thermoplastic resin or a thermoplastic elastomer composition having a thermoplastic resin and an elastomer blended therewith, the cylindrical film being disposed radially outwardly of the cylindrical inner rubber layer, comprising the steps of: wrapping an unvulcanized rubber layer cylindrically around a building drum to form the cylindrical inner rubber layer; and subsequently wrapping a sheet-shaped film formed of a thermoplastic resin or a thermoplastic elastomer composition having a thermoplastic resin and an elastomer blended therewith cylindrically around the cylindrical inner rubber layer, which is already wrapped around the building drum, to form the cylindrical film, wherein the unvulcanized rubber layer constituting the cylindrical inner rubber layer is a strip-shaped rubber layer, the cylindrical inner rubber layer being formed by spirally winding the strip-shaped rubber layer, wherein the strip-shaped rubber layer is spirally wound so as to partially overlap adjacent ends thereof with each other or so as to butt the adjacent ends against each other, the strip-shaped rubber layer having a width W 1 of 5 mm to 50 mm, a ratio of L 1 /W 1 of an overlapping amount L 1 of the adjacent ends to the width W 1 of the strip-shaped rubber layer being in a range of 0 to 0.8, wherein the unvulcanized rubber layer constituting the cylindrical inner rubber layer has a mean thickness in a range of 0.1 mm to 3.0 mm, wherein the sheet-shaped film has a thickness of 0.001 mm to 0.500 mm.