Pneumatic tire

Abstract

A pneumatic tire constituting part or all of the part members constituting the pneumatic tire by a rubber composition containing, based on a total 100 parts by weight of a rubber containing at least 70 parts by weight of an ethylenic unsaturated nitrile-conjugated diene-based highly saturated rubber having a content of conjugated diene units of not more than 30 percent by weight, 0 to 120 parts by weight of zinc methacrylate and 0 to 60 parts by weight of carbon black and having a total formulations of zinc methacrylate and carbon black of 10 to 120 parts by weight, and providing, between the above part members and the adjoining diene-based rubber layer, a bonding rubber layer comprising of a rubber composition containing, based on a total 100 parts by weight of a predetermined diene-based rubber and acrylonitrile butadiene copolymer rubber, 5 to 80 parts by weight of a predetermined aromatic petroleum resin.

1 . A pneumatic tire providing a rubber composition containing, based on a total 100 parts by weight of a rubber containing 70 to 100 parts by weight of an ethylenic unsaturated nitrile-conjugated diene-based highly saturated copolymer rubber having a content of conjugated diene units of not more than 30 percent by weight, 40 to 120 parts by weight of zinc methacrylate, containing no carbon black or containing not more than 40 parts by weight of the same, and having a total of formulations of zinc methacrylate and carbon black of not more than 120 parts by weight as the reinforcing rubber layer of the bead portion at least at part of a bead filler, and/or providing it as an auxiliary bead filler at the outside of the axial direction of the carcass wrapping layer, and bonding with the adjoining rubber layer through a bonding rubber layer containing, based on a total 100 parts by weight of (A) at least one type of diene-based rubber selected from the group consisting of a natural rubber, polyisoprene rubber, polybutadiene rubber, and conjugated diene-aromatic vinyl copolymer rubber and (B) an acrylonitrile-butadiene copolymer rubber, (C) 5 to 80 parts by weight of an aromatic petroleum resin having an average molecular weight of 300 to 1500, a softening point of 50 to 160° C., and an iodine adsorption value of at least 20 g/100 g.  
     
     
         2 . A pneumatic tire as set forth in  claim 1 , wherein the thickness of the bonding rubber layer is 0.1 to 2.0 mm.  
     
     
         3 . A pneumatic tire as set forth in  claim 1 , wherein the (A) diene-based rubber and (B) acrylonitrile-butadiene copolymer rubber contained in the bonding rubber layer have a ratio by weight in the range of A:B=10:90 to 90:10.  
     
     
         4 . A pneumatic tire as set forth in  claim 1 , wherein the bonding rubber layer further contains at least one co-cross-linking agent selected from the group consisting of a methacrylic acid higher ester, triallyl isocyanurate, metal salt of methacrylic acid or acrylic acid, diallyl phthalate ester, and 1,2-polybutadiene, and is cross-linked by an organic peroxide.  
     
     
         5 . A pneumatic tire providing at least at part of the bead toe portion a rubber composition containing 70 to 100 parts by weight of an ethylenic unsaturated nitrile-conjugated diene-based highly saturated rubber having a content or conjugated diene units of not more than 30 percent by weight and containing 20 to 120 parts by weight of zinc methacrylate.  
     
     
         6 . A pneumatic tire as set forth in  claim 5 , having a rubber composition of the bead toe portion further containing not more than 40 parts by weight of carbon black and having a total of formulations of zinc methacrylate and carbon black of not more than 120 parts by weight.  
     
     
         7 . A pneumatic tire as set forth in  claim 5 , bonding the rubber members of the bead toe portion with the adjoining rubber layers through a bonding rubber layer comprised of a rubber composition containing, based on a total 100 parts by weight of (A) at least one type of diene-based rubber selected from the group consisting of a natural rubber, polyisoprene rubber, polybutadiene rubber, and conjugated diene-aromatic vinyl copolymer rubber and (B) an acrylonitrile-butadiene copolymer rubber, (C) 5 to 80 parts by weight of an aromatic petroleum resin having an average molecular weight of 300 to 1500, a softening point of 50 to 160° C., and an iodine adsorption value of at least 20 g/l 100 g.  
     
     
         8 . A pneumatic tire as set forth in  claim 7 , wherein the ratio of weight (A)/(B) of the component (A) and component (B) in the bonding rubber layer is 90/10 to 10/90.  
     
     
         9 . A pneumatic tire as set forth in  claim 7 , wherein the thickness of the bonding rubber layer is 0.1 to 1.5 mm.  
     
     
         10 . A pneumatic tire as set forth in  claim 7 , wherein the bonding rubber layer further contains at least one co-cross-linking agent selected from the group consisting of a methacrylic acid higher ester, triallyl isocyanurate, metal salt of methacrylic acid or acrylic acid, diallyl phthalate ester, and 1,2-polybutadiene, and is cross-linked by an organic peroxide.