Method for manufacturing pneumatic tire

Abstract

In a method for manufacturing a pneumatic tire, molding of a green tire has an assembly step of bonding an inner liner and an unvulcanized rubber sheet with end portions thereof in a width direction being displaced from each other by 50 mm to 500 mm in the width direction to manufacture a laminate, cutting the laminate to have a constant length corresponding to a width of a drum to manufacture a cut sheet, and a joining step of winding the cut sheet on entire circumference of the drum such that a cut surface thereof extends in a circumferential direction of the drum and the inner liner is disposed on an inner surface side, and joining the end portions of the inner liner and joining the end portions of the unvulcanized rubber sheet such that positions of the joined end portions are displaced by a constant distance.

1 - 49 . (canceled) 
     
     
         50 . A method for manufacturing a pneumatic tire having an inner liner on an inner side of the tire, molding of a green tire comprising:
 (a) an assembly step of preparing an unvulcanized rubber sheet and the inner liner having a width larger than that of said unvulcanized rubber sheet, and bonding said inner liner and said unvulcanized rubber sheet with end portions thereof in a width direction being displaced from each other by 50 mm to 500 mm in the width direction such that both end portions of said unvulcanized rubber sheet in the width direction are located on an inner side of both end portions of said inner liner in the width direction to manufacture a laminate;   (b) a cutting step of cutting said laminate to have a constant length corresponding to a width of a drum to manufacture a cut sheet; and   (c) a joining step of winding said cut sheet on entire circumference of the drum such that a cut surface thereof extends in a circumferential direction of the drum and the inner liner is disposed on an inner surface side, and joining said cut sheet such that the both end portions of said inner liner in the width direction overlap each other,   said inner liner being a laminate of a first layer and a second layer, the first layer being a polymer composition containing 0.1 to 50 parts by mass of an organic derivative of a clay mineral relative to 100 parts by mass of a thermoplastic elastomer mixture containing 60 to 99% by mass of a styrene-isobutylene-styrene block copolymer and 1 to 40% by mass of a polyamide-based polymer which contains polyimide in a molecular chain and has a Shore D hardness of 70 or less, and having a thickness of 0.05 mm to 0.6 mm, the second layer being disposed on a side of the unvulcanized rubber sheet, made of a thermoplastic elastomer composition, and having a thickness of 0.01 mm to 0.3 mm.   
     
     
         51 . The method for manufacturing the pneumatic tire according to  claim 50 , wherein, in said joining step, the both end portions of the unvulcanized rubber sheet in the width direction are joined using an unvulcanized rubber piece. 
     
     
         52 . The method for manufacturing the pneumatic tire according to  claim 50 , wherein said second layer is a thermoplastic elastomer composition containing at least one of a styrene-isoprene-styrene block copolymer and a styrene-isobutylene block copolymer. 
     
     
         53 . The method for manufacturing the pneumatic tire according to  claim 50 , wherein 15 to 30% by mass of an ethylene-vinyl alcohol copolymer is contained in a polymer component of the thermoplastic elastomer mixture of said first layer. 
     
     
         54 . The method for manufacturing the pneumatic tire according to  claim 50 , wherein said styrene-isobutylene-styrene block copolymer contains 10 to 30% by mass of a styrene component. 
     
     
         55 . The method for manufacturing the pneumatic tire according to  claim 50 , wherein said polyamide-based polymer is a block copolymer composed of a polyamide component and a polyether component. 
     
     
         56 . The method for manufacturing the pneumatic tire according to  claim 50 , wherein said unvulcanized rubber sheet is a carcass ply. 
     
     
         57 . A method for manufacturing a pneumatic tire having an inner liner on an inner side of the tire, molding of a green tire comprising:
 (a) an assembly step of preparing an unvulcanized rubber sheet and the inner liner having a width larger than that of said unvulcanized rubber sheet, and bonding said inner liner and said unvulcanized rubber sheet with end portions thereof in a width direction being displaced from each other by 50 mm to 500 mm in the width direction such that both end portions of said unvulcanized rubber sheet in the width direction are located on an inner side of both end portions of said inner liner in the width direction to manufacture a laminate;   (b) a cutting step of cutting said laminate to have a constant length corresponding to a width of a drum to manufacture a cut sheet; and   (c) a joining step of winding said cut sheet on entire circumference of the drum such that a cut surface thereof extends in a circumferential direction of the drum and the inner liner is disposed on an inner surface side, and joining said cut sheet such that the both end portions of said inner liner in the width direction overlap each other,   said inner liner being formed of a laminate of a first layer and a second layer, the first layer containing more than or equal to 60% by mass and less than or equal to 99.5% by mass of a styrene-isobutylene-styrene triblock copolymer and more than or equal to 0.5% by mass and less than or equal to 40% by mass of a polymer obtained by polymerizing a monomer having 4 carbon atoms, and having a thickness of more than or equal to 0.05 mm and less than or equal to 0.6 mm, the second layer being disposed on a side of the unvulcanized rubber sheet, made of a thermoplastic elastomer, and having a thickness of 0.01 mm to 0.3 mm.   
     
     
         58 . The method for manufacturing the pneumatic tire according to  claim 57 , wherein, in said joining step, the both end portions of the unvulcanized rubber sheet in the width direction are joined using an unvulcanized rubber piece. 
     
     
         59 . The method for manufacturing the pneumatic tire according to  claim 57 , wherein said second layer has at least one of a styrene-isoprene-styrene triblock copolymer and a styrene-isobutylene diblock copolymer, has a thickness of more than or equal to 0.01 mm and less than or equal to 0.3 mm, and contains a polymer obtained by polymerizing a monomer having 4 carbon atoms by more than or equal to 0.5% by mass and less than or equal to 40% by mass of a polymer component. 
     
     
         60 . The method for manufacturing the pneumatic tire according to  claim 57 , wherein said polymer obtained by polymerizing a monomer having 4 carbon atoms is at least one of polybutene and polyisobutylene. 
     
     
         61 . The method for manufacturing the pneumatic tire according to  claim 57 , wherein said polymer obtained by polymerizing a monomer having 4 carbon atoms satisfies at least one of a number-average molecular weight of more than or equal to 300 and less than or equal to 3,000, a weight-average molecular weight of more than or equal to 700 and less than or equal to 100,000, and a viscosity-average molecular weight of more than or equal to 20,000 and less than or equal to 70,000. 
     
     
         62 . The method for manufacturing the pneumatic tire according to  claim 57 , wherein said styrene-isobutylene-styrene triblock copolymer has a weight-average molecular weight of more than or equal to 50,000 and less than or equal to 400,000, and a styrene unit content of more than or equal to 10% by mass and less than or equal to 30% by mass. 
     
     
         63 . The method for manufacturing the pneumatic tire according to  claim 59 , wherein said styrene-isoprene-styrene triblock copolymer has a weight-average molecular weight of more than or equal to 100,000 and less than or equal to 290,000, and a styrene unit content of more than or equal to 10% by mass and less than or equal to 30% by mass. 
     
     
         64 . The method for manufacturing the pneumatic tire according to  claim 59 , wherein said styrene-isobutylene diblock copolymer is a linear copolymer, and has a weight-average molecular weight of more than or equal to 40,000 and less than or equal to 120,000, and a styrene unit content of more than or equal to 10% by mass and less than or equal to 35% by mass. 
     
     
         65 . A method for manufacturing a pneumatic tire having an inner liner on an inner side of the tire, molding of a green tire comprising:
 (a) an assembly step of preparing an unvulcanized rubber sheet and the inner liner having a width larger than that of said unvulcanized rubber sheet, and bonding said inner liner and said unvulcanized rubber sheet with end portions thereof in a width direction being displaced from each other by 50 mm to 500 mm in the width direction such that both end portions of said unvulcanized rubber sheet in the width direction are located on an inner side of both end portions of said inner liner in the width direction to manufacture a laminate;   (b) a cutting step of cutting said laminate to have a constant length corresponding to a width of a drum to manufacture a cut sheet; and   (c) a joining step of winding said cut sheet on entire circumference of the drum such that a cut surface thereof extends in a circumferential direction of the drum and the inner liner is disposed on an inner surface side, and joining said cut sheet such that the both end portions of said inner liner in the width direction overlap each other,   said inner liner including a polymer sheet containing more than or equal to 0.1 parts by mass and less than or equal to 5 parts by mass of sulfur relative to 100 parts by mass of a polymer component containing more than or equal to 5% by mass and less than or equal to 40% by mass of a styrene-isobutylene-styrene triblock copolymer and more than or equal to 60% by mass and less than or equal to 95% by mass of at least one rubber component selected from the group consisting of natural rubber, isoprene rubber, and butyl rubber.   
     
     
         66 . The method for manufacturing the pneumatic tire according to  claim 65 , wherein, in said joining step, the both end portions of the unvulcanized rubber sheet in the width direction are joined using an unvulcanized rubber piece. 
     
     
         67 . The method for manufacturing the pneumatic tire according to  claim 65 , wherein said polymer sheet further contains more than or equal to 1 part by mass and less than or equal to 5 parts by mass of stearic acid, more than or equal to 0.1 parts by mass and less than or equal to 8 parts by mass of zinc oxide, more than or equal to 0.1 parts by mass and less than or equal to 5 parts by mass of an age inhibitor, and more than or equal to 0.1 parts by mass and less than or equal to 5 parts by mass of a vulcanization accelerator, relative to 100 parts by mass of the polymer component. 
     
     
         68 . The method for manufacturing the pneumatic tire according to  claim 65 , wherein said styrene-isobutylene-styrene triblock copolymer has a weight-average molecular weight of more than or equal to 50,000 and less than or equal to 400,000, and a styrene unit content of more than or equal to 10% by mass and less than or equal to 30% by mass. 
     
     
         69 . The method for manufacturing the pneumatic tire according to  claim 65 , wherein said inner liner is a laminate of a first layer and a second layer, the first layer being a polymer sheet made of a polymer composition containing more than or equal to 0.1 parts by mass and less than or equal to 5 parts by mass of sulfur relative to 100 parts by mass of a polymer component containing more than or equal to 5% by mass and less than or equal to 40% by mass of a styrene-isobutylene-styrene triblock copolymer and more than or equal to 60% by mass and less than or equal to 95% by mass of at least one rubber component selected from the group consisting of natural rubber, isoprene rubber, and butyl rubber, the second layer being made of a thermoplastic resin composition containing more than or equal to 0.1 parts by mass and less than or equal to 5 parts by mass of sulfur relative to 100 parts by mass of a thermoplastic elastomer. 
     
     
         70 . The method for manufacturing the pneumatic tire according to  claim 69 , wherein the polymer composition of said first layer further contains more than or equal to 1 part by mass and less than or equal to 5 parts by mass of stearic acid, more than or equal to 0.1 parts by mass and less than or equal to 8 parts by mass of zinc oxide, more than or equal to 0.1 parts by mass and less than or equal to 5 parts by mass of an age inhibitor, and more than or equal to 0.1 parts by mass and less than or equal to 5 parts by mass of a vulcanization accelerator, relative to 100 parts by mass of said polymer component. 
     
     
         71 . The method for manufacturing the pneumatic tire according to  claim 69 , wherein said thermoplastic elastomer is at least one selected from the group consisting of a styrene-isoprene-styrene triblock copolymer, a styrene-isobutylene diblock copolymer, a styrene-butadiene-styrene triblock copolymer, a styrene-isoprene.butadiene-styrene triblock copolymer, a styrene-ethylene.butene-styrene triblock copolymer, a styrene-ethylene.propylene-styrene triblock copolymer, a styrene-ethylene.ethylene.propylene-styrene triblock copolymer, a styrene-butadiene.butylene-styrene triblock copolymer, and epoxy-modified thermoplastic elastomers thereof. 
     
     
         72 . The method for manufacturing the pneumatic tire according to  claim 69 , wherein said second layer includes at least one of an SIS layer in which the thermoplastic elastomer contains a styrene-isoprene-styrene triblock copolymer, an SIB layer in which the thermoplastic elastomer contains a styrene-isobutylene diblock copolymer, and an epoxidized SBS layer in which the thermoplastic elastomer contains an epoxidized styrene-butadiene-styrene triblock copolymer. 
     
     
         73 . The method for manufacturing the pneumatic tire according to  claim 65 , wherein said styrene-isobutylene-styrene triblock copolymer has a weight-average molecular weight of more than or equal to 50,000 and less than or equal to 400,000, and a styrene unit content of more than or equal to 10% by mass and less than or equal to 30% by mass. 
     
     
         74 . The method for manufacturing the pneumatic tire according to  claim 72 , wherein said styrene-isoprene-styrene triblock copolymer has a weight-average molecular weight of more than or equal to 100,000 and less than or equal to 290,000, and a styrene unit content of more than or equal to 10% by mass and less than or equal to 30% by mass. 
     
     
         75 . The method for manufacturing the pneumatic tire according to  claim 72 , wherein said styrene-isobutylene diblock copolymer is a linear copolymer, and has a weight-average molecular weight of more than or equal to 40,000 and less than or equal to 120,000, and a styrene unit content of more than or equal to 10% by mass and less than or equal to 35% by mass. 
     
     
         76 . A method for manufacturing a pneumatic tire having an inner liner on an inner side of the tire, molding of a green tire comprising:
 (a) an assembly step of preparing an unvulcanized rubber sheet and the inner liner having a width larger than that of said unvulcanized rubber sheet, and bonding said inner liner and said unvulcanized rubber sheet with end portions thereof in a width direction being displaced from each other by 50 mm to 500 mm in the width direction such that both end portions of said unvulcanized rubber sheet in the width direction are located on an inner side of both end portions of said inner liner in the width direction to manufacture a laminate;   (b) a cutting step of cutting said laminate to have a constant length corresponding to a width of a drum to manufacture a cut sheet; and   (c) a joining step of winding said cut sheet on entire circumference of the drum such that a cut surface thereof extends in a circumferential direction of the drum and the inner liner is disposed on an inner surface side, and joining said cut sheet such that the both end portions of said inner liner in the width direction overlap each other,   said inner liner being composed of a first layer disposed on the inner side of the tire and a second layer disposed in contact with a rubber layer of a carcass ply, said first layer being a thermoplastic elastomer composition mainly composed of a styrene-isobutylene-styrene block copolymer, said second layer being a styrene-based thermoplastic elastomer composition,   (1) at least one of the thermoplastic elastomer compositions of said first and second layers containing 0.1 to 100 parts by mass of a tackifier relative to 100 parts by mass of a thermoplastic elastomer component, or   (2) said second layer containing a styrene-isobutylene-styrene block copolymer by 10 to 80% by mass of a thermoplastic elastomer component.   
     
     
         77 . The method for manufacturing the pneumatic tire according to  claim 76 , wherein, in said joining step, the both end portions of the unvulcanized rubber sheet in the width direction are joined using an unvulcanized rubber piece. 
     
     
         78 . The method for manufacturing the pneumatic tire according to  claim 76 , wherein said tackifier has a weight-average molecular weight Mw of 1×10 2  to 1×10 6 , and a softening point within a range of 50° C. to 150° C. 
     
     
         79 . The method for manufacturing the pneumatic tire according to  claim 76 , wherein said second layer is a thermoplastic elastomer composition containing at least one of a styrene-isoprene-styrene block copolymer and a styrene-isobutylene diblock copolymer. 
     
     
         80 . The method for manufacturing the pneumatic tire according to  claim 76 , wherein said first layer has a thickness of 0.05 mm to 0.6 mm and the second layer has a thickness of 0.01 mm to 0.3 mm. 
     
     
         81 . The method for manufacturing the pneumatic tire according to  claim 76 , wherein said styrene-isobutylene-styrene triblock copolymer has a weight-average molecular weight of more than or equal to 50,000 and less than or equal to 400,000, and a styrene unit content of more than or equal to 10% by mass and less than or equal to 30% by mass. 
     
     
         82 . The method for manufacturing the pneumatic tire according to  claim 79 , wherein said styrene-isoprene-styrene triblock copolymer has a weight-average molecular weight of more than or equal to 100,000 and less than or equal to 290,000, and a styrene unit content of more than or equal to 10% by mass and less than or equal to 30% by mass. 
     
     
         83 . The method for manufacturing the pneumatic tire according to  claim 79 , wherein said styrene-isobutylene diblock copolymer is a linear copolymer, and has a weight-average molecular weight of more than or equal to 40,000 and less than or equal to 120,000, and a styrene unit content of more than or equal to 10% by mass and less than or equal to 35% by mass. 
     
     
         84 . A method for manufacturing a pneumatic tire having an inner liner on an inner side of the tire, molding of a green tire comprising:
 (a) an assembly step of preparing an unvulcanized rubber sheet and the inner liner having a width larger than that of said unvulcanized rubber sheet, and bonding said inner liner and said unvulcanized rubber sheet with end portions thereof in a width direction being displaced from each other by 50 mm to 500 mm in the width direction such that both end portions of said unvulcanized rubber sheet in the width direction are located on an inner side of both end portions of said inner liner in the width direction to manufacture a laminate;   (b) a cutting step of cutting said laminate to have a constant length corresponding to a width of a drum to manufacture a cut sheet; and   (c) a joining step of winding said cut sheet on entire circumference of the drum such that a cut surface thereof extends in a circumferential direction of the drum and the inner liner is disposed on an inner surface side, and joining said cut sheet such that the both end portions of said inner liner in the width direction overlap each other,   said inner liner being composed of a composite layer of a first layer disposed on the inner side of the tire and a second layer disposed in contact with said unvulcanized rubber sheet,   at least one of said first layer and said second layer being made of an elastomer composition containing an isobutylene-based modified copolymer which is made of a polymer block (A) mainly composed of isobutylene and a polymer block (B) mainly composed of an aromatic vinyl-based compound, and in which at least one of the blocks contains β-pinene.   
     
     
         85 . The method for manufacturing the pneumatic tire according to  claim 84 , wherein, in said joining step, the both end portions of the unvulcanized rubber sheet in the width direction are joined using an unvulcanized rubber piece. 
     
     
         86 . The method for manufacturing the pneumatic tire according to  claim 84 , wherein the elastomer composition of said first layer contains the isobutylene-based modified copolymer by 10 to 100% by mass of an entire elastomer component. 
     
     
         87 . The method for manufacturing the pneumatic tire according to  claim 84 , wherein the elastomer composition of said second layer contains the isobutylene-based modified copolymer by 5 to 80% by mass of an entire elastomer component. 
     
     
         88 . The method for manufacturing the pneumatic tire according to  claim 84 , wherein a content of β-pinene in said isobutylene-based modified copolymer is 0.5 to 25% by mass. 
     
     
         89 . The method for manufacturing the pneumatic tire according to  claim 84 , wherein said isobutylene-based modified copolymer has a weight-average molecular weight of 30,000 to 400,000, and a value of molecular weight distribution (Mw/Mn) of less than or equal to 1.3. 
     
     
         90 . The method for manufacturing the pneumatic tire according to  claim 84 , wherein, in said isobutylene-based modified copolymer, fβ-pinene is contained in a styrene block of a styrene-isobutylene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, or a styrene-isobutylene block copolymer. 
     
     
         91 . A method for manufacturing a pneumatic tire having an inner liner on an inner side of the tire, molding of a green tire comprising:
 (a) an assembly step of preparing an unvulcanized rubber sheet and the inner liner having a width larger than that of said unvulcanized rubber sheet, and bonding said inner liner and said unvulcanized rubber sheet with end portions thereof in a width direction being displaced from each other by 50 mm to 500 mm in the width direction such that both end portions of said unvulcanized rubber sheet in the width direction are located on an inner side of both end portions of said inner liner in the width direction to manufacture a laminate;   (b) a cutting step of cutting said laminate to have a constant length corresponding to a width of a drum to manufacture a cut sheet; and   (c) a joining step of winding said cut sheet on entire circumference of the drum such that a cut surface thereof extends in a circumferential direction of the drum and the inner liner is disposed on an inner surface side, and joining said cut sheet such that the both end portions of said inner liner in the width direction overlap each other,   said inner liner being composed of a composite layer of a first layer disposed on the inner side of the tire and a second layer disposed in contact with said unvulcanized rubber sheet,   said first layer being made of an elastomer composition containing an SIBS modified copolymer having a styrene block moiety of a styrene-isobutylene-styrene block copolymer modified with an acid chloride having an unsaturated bond or an acid anhydride and having a thickness of 0.05 mm to 0.6 mm,   said second layer being made of an elastomer composition containing at least one of a styrene-isoprene-styrene block copolymer and a styrene-isobutylene block copolymer, and having a thickness of 0.01 mm to 0.3 mm.   
     
     
         92 . The method for manufacturing the pneumatic tire according to  claim 91 , wherein, in said joining step, the both end portions of the unvulcanized rubber sheet in the width direction are joined using an unvulcanized rubber piece. 
     
     
         93 . The method for manufacturing the pneumatic tire according to  claim 91 , wherein a blending quantity of the SIBS modified copolymer in said first layer ranges from 10% by mass to 100% by mass of an elastomer component. 
     
     
         94 . The method for manufacturing the pneumatic tire according to  claim 91 , wherein said second layer contains an SIBS modified copolymer, and a blending quantity thereof ranges from 5% by mass to 80% by mass of a thermoplastic elastomer component. 
     
     
         95 . The method for manufacturing the pneumatic tire according to  claim 91 , wherein said first layer is a mixture of the styrene-isobutylene-styrene block copolymer and the SIBS modified copolymer. 
     
     
         96 . The method for manufacturing the pneumatic tire according to  claim 91 , wherein one of said first and second layers is blended with a tackifier. 
     
     
         97 . The method for manufacturing the pneumatic tire according to  claim 91 , wherein one of said first and second layers is blended with a rubber component by 5 to 75% by mass of an elastomer component. 
     
     
         98 . The method for manufacturing the pneumatic tire according to  claim 91 , wherein said first layer is blended with at least one of an ultraviolet absorber and an antioxidant by 0.5 parts by mass to 40 parts by mass relative to 100 parts by mass of an elastomer component.