A pneumatic tire comprising an air permeation preventive layer comprising a film of a thermoplastic resin composition containing a polyvinyl alcohol or ethylene vinyl alcohol copolymer, to which a protective film of a rubber composition containing an ethylene propylene rubber (EPM) or ethylene propylene diene rubber (EPDM) is, directly or via an adhesive, placed adjacent thereto, as one layer in at least one side thereof, whereby both a further reduction in the air leakage rate of the pneumatic tire and a good durability can be achieved and furthermore a reduction in the weight of the tire can be achieved.
1. A pneumatic tire comprising:
(A) an air permeation preventive layer containing a film of a thermoplastic resin composition containing a polyvinyl alcohol or ethylene vinyl alcohol copolymer having an air permeation coefficient of 2×10 −12 cc·cm/cm 2 ·sec·cmHg or less; and
(B) a protective film of a rubber composition consisting essentially of, as a main component, an ethylene propylene rubber (EPM) or ethylene propylene diene rubber (EPDM) and, as a smaller component, at least one member selected from the group consisting of a diene-based rubber, an olefin-based rubber and a thermoplastic rubber, adjacent to the air permeation preventive layer, directly or via an adhesive, as one layer located at least at the innermost surface of the air permeation preventive layer (A), which is arranged at the innermost surface of the tire ,whereby said tire includes a further reduction in the air leakage rate of the pneumatic tire with a good durability and a reduction in the weight of the tire.
2. A pneumatic tire as claimed in claim 1 , wherein the air permeation preventive layer (A) has a thickness of 0.1 to 20 μm.
3. A pneumatic tire as claimed in claim 1 , wherein the rubber composition containing EPM or EPDM has an EPM or EPDM content of 10 parts by weight or more, based upon 100 parts by weight of the rubber.
4. A pneumatic tire as claimed in claim 1 , wherein the air permeation preventive layer (A) is sandwiched with the protective film (B) at both the inner and outer surfaces thereof.
5. A pneumatic tire as claimed in claim 1 , wherein the protective film (B) containing EPM or EPDM has a thickness of 0.05 to 7 mm.
6. A pneumatic tire as claimed in claim 2 , wherein the rubber composition containing EPM or EPDM has an EPM or EPDM content of 10 parts by weight or more, based upon 100 parts by weight of the rubber.
7. A pneumatic tire as claimed in claim 2 , wherein the protective film (B) containing EPM or EPDM has a thickness of 0.05 to 7 mm.
8. A pneumatic tire as claimed in claim 3 , wherein the protective film (B)-containing EPM or EPDM has a thickness of 0.05 to 7 mm.
9. A pneumatic tire as claimed in claim 4 , wherein the protective film (B) containing EPM or EPDM has a thickness of 0.05 to 7 mm.
10. A pneumatic tire as claimed in claim 5 , wherein the protective film (B) containing EPM or EPDM has a thickness of 0.05 to 7 mm.