Pneumatic tire

Abstract

A pneumatic tire using as an air permeation prevention layer a film consisting of thermoplastic resin or thermoplastic elastomer composition obtained by blending thermoplastic resin with elastomer, wherein the film is prevented form being peeled off to prevent entry of a release agent into the interior and the internal view of the tire is improved. An air permeation prevention layer (10) disposed on the inner side of the tire is constituted of a laminate (14) obtained by layering ribbon-form elastomer layers (12, 13) on the opposite sides of a ribbon-form film (11). The laminate (14) is wound in the tire circumferential direction while being overlapped partially and deviated at specified intervals. Respective adjoining winding portions (14A1, 14A2) of the laminate (14) are joined by being overlapped partially with ribbon-form films (11) kept separated from each other.

Description

TECHNICAL FIELD[0001]The present invention relates to a pneumatic tire in which a film formed of a thermoplastic resin or thermoplastic elastomer composition comprising a blend of a thermoplastic resin and an elastomer is used for an air impermeable layer, and more particularly, to a pneumatic tire which can prevent separation of the film and improve an inner appearance of the tire.TECHNICAL BACKGROUND[0002]There have conventionally been known a pneumatic tire in which a film formed of a thermoplastic resin or thermoplastic elastomer composition comprising a blend of a thermoplastic resin and an elastomer is used for an air impermeable layer (inner liner) disposed on the inner side of the tire (see a patent document 1, for example).[0003]The opposite ends of the film in the circumferential direction of the tire are spliced to each other in an overlapping manner to form the above air impermeable layer. However, the film having the thermoplastic resin as a main component has a low adh...

AI Technical Summary

Benefits of technology

[0008]According to the present invention described above, the air impermeable layer is formed from a laminated body comprising a ribbon-shaped film and ribbon-shaped elastomer plies laminated on opposite sides thereof, and each pair of adjacent wound portions are spliced to each other in a state where the ribbon-shaped film is disengaged from itself. Therefore, the spliced parts of the adjacent wound portions can be prevented from easily separating from each other during building of a green tire. Accordingly, a mold release agent applied to the inner surface of the green tire does not come inside during curing of the green tire.

[0009]Since the ribbon-shaped elastomer plies are laminated on the film, the ribbon-shaped film is not exposed in the inner surface of the tire but one of the ribbon-shaped elastomer plies which are not easily subjected to blemishes is exposed. Therefore, occurrence of blemishes in the inner surface of the tire is avoided after curing, enabling an inner appearance of the tire to be improved.

Problems solved by technology

However, the film having the thermoplastic resin as a main component has a low adhesion.

Therefore, even if the opposite ends of the film are spliced by pressing, the spliced opposite ends of the film are separated from each other during building of a green tire, which creates a problem of a mold release agent, applied to the inner surface of the tire, which comes in between the opposite ends of the film from the separated place of the film during curing of the green tire.

If the mold release agent comes in between the opposite ends of the film as described above, adhesion of the film between the opposite ends is lowered, whereby the film is opened between the opposite ends during running, and the opened part becomes a starting point of tire trouble.

Further, the above film is subject to blemish because it is soft under high temperatures.

Therefore, when the curing bladder is folded in order to remove a tire from a tire curing press after curing, the film receives a blemish if the curing bladder comes into contact with the film on the inner side of the tire and is rubbed against the surface of the film, which produces a problem of deteriorating an inner appearance of a brand-new tire.

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