Pneumatic radial tire and process for producing retreaded tire

A pneumatic radial tire comprising:

• at least one carcass layer suspended across left and right bead parts;
• a belt layer arranged on an outer circumferential side of the carcass layer;
• and
• a tread arranged on an outer circumferential side of the belt layer, wherein the tread has a laminated structure in which a thermoplastic film layer, made of any one of a thermoplastic resin and a thermoplastic elastomer composition obtained by blending an elastomer in a thermoplastic resin, is interposed between a tread-side rubber layer and a belt layer-side rubber layer, wherein
• a thickness of the belt layer-side rubber layer is not less than 2 mm and not more than 5 mm, wherein when the tread is sufficiently heated the thermoplastic film layer is softened by the heating whereby the tread-side rubber layer can be separated from the belt-side rubber layer at the softened thermoplastic film layer without a buffing operation,
• a thickness of the thermoplastic film layer is 50 to 150 μm, and
• a large number of through-holes are provided in the thermoplastic film layer.

A process for producing a retreaded tire, comprising the steps of:

• forming a base tire from a pneumatic radial tire comprising:
• at least one carcass layer suspended across left and right bead parts;
• a belt layer arranged on an outer circumferential side of the carcass layer;
• and
• a tread arranged on an outer circumferential side of the belt layer, wherein the tread has a laminated structure in which a thermoplastic film layer, made of any one of a thermoplastic resin and a thermoplastic elastomer composition obtained by blending an elastomer in a thermoplastic resin, is interposed between a tread-side rubber layer and a belt layer-side rubber layer, and the tread-side rubber layer being partially worn away;
• wherein the base tire is formed by sufficiently heating the tread so as to soften the thermoplastic film layer through the heating, then separating and removing the tread-side rubber layer from the belt-side rubber layer at the softened thermoplastic film layer without a buffing operation, and
• subsequently bonding a new tread-side rubber layer onto the base tire.

A process for producing a retreaded tire, comprising the steps of:

• forming a base tire from a pneumatic radial tire comprising:
• at least one carcass layer suspended across left and right bead parts;
• a belt layer arranged on an outer circumferential side of the carcass layer;
• and
• a tread arranged on an outer circumferential side of the belt layer, wherein the tread has a laminated structure in which a thermoplastic film layer, made of any one of a thermoplastic resin and a thermoplastic elastomer composition obtained by blending an elastomer in a thermoplastic resin, is interposed between a tread-side rubber layer and a belt layer-side rubber layer, and the tread-side rubber layer being partially worn away;
• wherein a width of the thermoplastic film layer is at least equal to or larger than a maximum width of the belt layer;
• and wherein the base tire is formed by sufficiently heating the tread so as to soften the thermoplastic film layer through the heating, then separating and removing the tread-side rubber layer from the belt-side rubber layer at the softened thermoplastic film layer without a buffing operation, and
• subsequently bonding a new tread-side rubber layer onto the base tire.