Method of forming tire innerliner and method of producing pneumatic tire

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 W1 of 5 mm to 50 mm, a ratio of L1/W1 of an overlapping amount L1 of the adjacent ends to the width W1 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.