JP2009226997A - Pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic tire using for an inner liner layer, a film formed of a thermoplastic resin or a thermoplastic elastomer composition that an elastomer is blended into the thermoplastic resin, while reducing vulcanizing troubles of the inner liner layer resulting from a finishing layer protecting the base face of a bead portion. <P>SOLUTION: In the pneumatic tire, the film 71 is formed of the thermoplastic resin or the thermoplastic elastomer composition that the elastomer is blended into the thermoplastic resin, the inner liner layer 7 formed by holding the film 71 at both sides between rubber layers 72, 73 is arranged on the side of a tire cavity beyond a carcass layer 4, and the finishing layer 8 protecting the base face of the bead portion 3 is arranged so that the inside end in a tire axial direction is overlapped with the inner liner layer 7. As the finishing layer, a finishing layer 8 is provided for generating shrinkage stress smaller than the breaking strength of the inner liner layer 7 and smaller than delamination critical stress between the inner liner layer 7 and itself during releasing the tire from a vulcanizer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pneumatic tire in which a film made of a thermoplastic resin or a thermoplastic elastomer composition obtained by blending an elastomer with a thermoplastic resin is used as an inner liner layer, and more specifically, a finishing layer for protecting a base surface of a bead portion. The present invention relates to a pneumatic tire that reduces the vulcanization failure of an inner liner layer caused by the above.

  In recent years, it has been proposed to dispose a thermoplastic resin or a film made of a thermoplastic elastomer composition obtained by blending an elastomer and a thermoplastic resin as an inner liner layer (air permeation preventive layer) on the tire inner surface (for example, Patent Document 1). To 3).

  However, while the inner liner layer made of such a film is arranged on the inner surface of the tire, the textile finishing layer for protecting the base surface of the bead portion is arranged so that the end on the inner side in the tire axial direction overlaps the inner liner layer. In this case, when the tire heated to a temperature of about 180 ° C. during vulcanization is discharged from the vulcanizer, the organic fiber cord of the finishing layer shrinks, and the film of the inner liner layer in the high temperature state becomes the finishing layer Insufficient endurance of the shrinkage force may cause a vulcanization failure that stretches in the radial direction of the tire and divides or foams. Such a vulcanization failure is not acceptable in terms of performance as well as product appearance. Therefore, when manufacturing a pneumatic tire provided with a film-made inner liner layer, it is desired to reduce the vulcanization failure of the inner liner layer caused by the finishing layer.

JP-A-8-217923 Japanese Patent Laid-Open No. 10-81108 JP-A-11-199713

  An object of the present invention is to use an inner liner layer resulting from a finishing layer for protecting a base surface of a bead portion when a film made of a thermoplastic resin or a thermoplastic elastomer composition obtained by blending an elastomer with a thermoplastic resin is used as an inner liner layer. An object of the present invention is to provide a pneumatic tire that reduces the vulcanization failure.

  In order to achieve the above object, a pneumatic tire according to the present invention includes an inner liner layer formed by sandwiching a thermoplastic resin or a film made of a thermoplastic elastomer composition obtained by blending an elastomer with a thermoplastic resin with rubber layers from both sides. A pneumatic tire that is disposed closer to the tire lumen than the carcass layer and that has a finishing layer that protects the base surface of the bead portion so that an end on the inner side in the tire axial direction overlaps the inner liner layer. When the tire is discharged from the vulcanizer, a finishing layer is provided that generates a shrinkage stress that is smaller than the breaking strength of the inner liner layer and smaller than the delamination limit stress with the inner liner layer. It is characterized by that.

  In the present invention, when a film made of a thermoplastic resin or a thermoplastic elastomer composition is used for the inner liner layer, when the tire is released from the vulcanizer as the finishing layer, the breaking strength of the inner liner layer is smaller, In addition, a finishing layer that generates a shrinkage stress smaller than the delamination limit stress with the inner liner layer is provided. Thereby, the vulcanization failure of the inner liner layer resulting from the finishing layer protecting the base surface of the bead portion can be reduced.

  In the present invention, when the tire is released from the vulcanizer, a finishing layer that generates a shrinkage stress that is smaller than the fracture strength of the inner liner layer and smaller than the delamination limit stress with the inner liner layer. Means a finishing layer having physical properties such that when the tire is discharged from the vulcanizer, the inner liner layer is not destroyed and does not peel from the inner liner layer. More specifically, the following structure can be adopted.

  That is, the finishing layer is composed of a rubber composition and an organic fiber cord textile embedded in the rubber composition, and the thickness of the rubber portion interposed between the film of the inner liner layer and the organic fiber cord of the finishing layer is set. It is good to set it to 0.5 mm-3.0 mm. In this case, the shrinkage stress generated by the finishing layer can be relaxed by the rubber portion.

  Further, the finishing layer may be composed of a rubber composition and an organic fiber cord textile embedded in the rubber composition, and the organic fiber cord of the finishing layer may be arranged in the tire circumferential direction. In this case, it is possible to avoid the shrinkage stress generated by the finishing layer from tearing the film of the inner liner layer in the tire radial direction.

  Further, the finishing layer is composed of a rubber composition and an organic fiber cord textile embedded in the rubber composition, the organic fiber cord of the finishing layer is arranged in a direction crossing the tire circumferential direction, and the organic fiber It is preferable to cut the cord at a position that does not overlap with the film of the inner liner layer and at the inner side in the tire axial direction from the bead core. In this case, the shrinkage stress generated by the finishing layer can be prevented from acting on the film of the inner liner layer.

  Moreover, it is good to comprise a finishing layer only with a rubber composition. In this case, the shrinkage stress generated by the finishing layer can be minimized.

  Further, the finishing layer is composed of a rubber composition and short fibers blended in the rubber composition, the average length L of the short fibers of the finishing layer is 10 μm or more and 5000 μm or less, and the average length L and the average diameter D are The aspect ratio L / D is preferably 10 or more and 500 or less. In this case, the shrinkage stress generated by the finishing layer can be minimized, and the base surface of the bead portion is protected in the same manner as when the textile of organic fiber cord is embedded by the reinforcing effect based on the blending of short fibers. be able to.

  The rubber composition constituting the finishing layer has a Mooney viscosity at 100 ° C. in an unvulcanized state of 35 to 50, and a modulus at 100% elongation at 23 ° C. after vulcanization of 0.6 MPa to 1. It is preferable to use a rubber composition that is 3 MPa and has a dynamic elastic modulus E ′ at 20 ° C. after vulcanization of 2.0 MPa to 5.5 MPa. By using a soft rubber composition having such physical properties, the effect of suppressing vulcanization failure can be enhanced.

  Here, the Mooney viscosity at 100 ° C. in the unvulcanized state is measured based on JIS K6300. The modulus at 100% elongation at 23 ° C. after vulcanization shall be measured based on the tensile test of JIS K6251. The dynamic elastic modulus E ′ at 20 ° C. after vulcanization is measured using a viscoelastic spectrometer manufactured by Toyo Seiki Seisakusho under the conditions of static strain 10%, dynamic strain ± 2%, and frequency 20 Hz. And In measuring physical properties after vulcanization, unvulcanized rubber is pressed for 15 minutes at a temperature of 160 ° C. and a pressure of 2 MPa to produce a vulcanized sheet having a thickness of 2 mm, and a test piece is punched from the vulcanized sheet. It is desirable.

  Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a pneumatic tire according to an embodiment of the present invention, and FIG. 2 shows a pneumatic tire according to another embodiment of the present invention. 1 and 2, 1 is a tread portion, 2 is a sidewall portion, and 3 is a bead portion. A carcass layer 4 is mounted between the pair of left and right bead portions 3, 3, and an end portion of the carcass layer 4 is folded around the bead core 5 from the inside of the tire to the outside. A plurality of belt layers 6 are embedded on the outer peripheral side of the carcass layer 4 in the tread portion 1. These belt layers 6 are disposed such that the reinforcing cords are inclined with respect to the tire circumferential direction, and the reinforcing cords cross each other between the layers.

  In the pneumatic tire, an inner liner layer 7 (air permeation preventive layer) is disposed on the tire lumen side of the carcass layer 4. FIG. 3 is an enlarged cross-sectional view of the inner liner layer of the pneumatic tire. As shown in FIG. 3, the inner liner layer 7 includes a film 71 made of a thermoplastic resin or a thermoplastic elastomer composition, and a rubber layer 72 laminated on the tire lumen side of the film 71 so as to cover the film 71. The rubber layer 73 is laminated on the carcass layer side of the film 71 so as to cover the film 71.

  The thickness of the film 71 is not particularly limited, but can be selected from a range of 0.001 mm to 0.5 mm. The thickness of the rubber layers 72 and 73 is preferably 0.1 mm to 2.0 mm in the state of the material at the time of molding.

  The finishing layer 8 is disposed so as to wrap the bead portion 3 from the inner side in the tire radial direction, and protects the base surface of the bead portion 3. The end of the finishing layer 8 on the inner side in the tire axial direction is disposed so as to overlap the inner liner layer 7. When laminating the finishing layer 8 and the inner liner layer 7, the inner liner layer 7 may be sandwiched between the finishing layer 8 and the carcass layer 4 (FIG. 1). Alternatively, the finishing layer 8 may be combined with the inner liner layer 7. A structure sandwiched between the carcass layers 4 (FIG. 2) may be used.

  In the pneumatic tire configured as described above, the shrinkage stress generated by the finishing layer 8 when the tire is discharged from the vulcanizer is smaller than the breaking strength of the inner liner layer 7, and the inner liner layer 7 It is set to be smaller than the delamination limit stress. That is, the inner liner layer 7 is not destroyed by the shrinkage stress generated by the finishing layer 8 when the tire is discharged from the vulcanizer, and the peeling between the finishing layer 8 and the inner liner layer 7 does not occur. . Thereby, the vulcanization failure of the inner liner layer 7 resulting from the finishing layer 8 protecting the base surface of the bead part 3 can be reduced.

  FIG. 4 is a sectional view showing the first embodiment of the finishing layer. In FIG. 4, the finishing layer 8A is composed of a rubber composition 81A and an organic fiber cord 82A textile embedded in the rubber composition 81A. The arrangement direction of the organic fiber cords 82A is not particularly limited, but here the organic fiber cords 82A are arranged in a direction intersecting with the tire circumferential direction at an angle of, for example, 30 ° to 80 °. A rubber sheet 9 is inserted between the inner liner layer 7 and the finishing layer 8A. Thereby, the thickness t of the rubber portion interposed between the film 71 of the inner liner layer 7 and the organic fiber cord 82A of the finishing layer 8A is set in the range of 0.5 mm to 3.0 mm.

  According to the above structure, when the tire is discharged from the vulcanizer, the shrinkage stress generated mainly due to the shrinkage of the organic fiber cord 82A of the finishing layer 8A is relieved by the rubber portion having the thickness t. Thereby, the vulcanization failure of the inner liner layer 7 resulting from the finishing layer 8A can be reduced. Here, if the thickness t of the rubber portion interposed between the film 71 of the inner liner layer 7 and the organic fiber cord 82A of the finishing layer 8A is less than 0.5 mm, the effect of reducing the vulcanization failure cannot be obtained. Conversely, if it exceeds 3.0 mm, the shape of the bead portion will be adversely affected.

  FIG. 5 is a perspective cross-sectional view showing a second embodiment of the finishing layer. In FIG. 5, the finishing layer 8B is composed of a rubber composition 81B and a textile (woven fabric) of organic fiber cords 82B embedded in the rubber composition 81B. The organic fiber cords 82B of the finishing layer 8B are arranged in the tire circumferential direction. The organic fiber cords 82B of the finishing layer 8B are desirably arranged at 0 ° with respect to the tire circumferential direction, but may be arranged at an angle of 10 ° or less with respect to the tire circumferential direction.

  According to the above structure, even if the organic fiber cord 82B of the finishing layer 8B contracts when the tire is discharged from the vulcanizer, the contraction stress does not tear the inner liner layer 7 in the tire radial direction. Thereby, the vulcanization failure of the inner liner layer 7 resulting from the finishing layer 8B can be reduced.

  FIG. 6 is a cross-sectional view showing a third embodiment of the finishing layer. In FIG. 6, the finishing layer 8 </ b> C is composed of a rubber composition 81 </ b> C and an organic fiber cord 82 </ b> C textile embedded in the rubber composition 81 </ b> C. The organic fiber cords 82C of the finishing layer 8C are arranged in a direction that intersects the tire circumferential direction at an angle of, for example, 30 ° to 80 °. The organic fiber cord 82 </ b> C is cut at a position that does not overlap with the film 71 of the inner liner layer 7 and at a position on the inner side in the tire axial direction from the bead core 5.

  According to the above structure, even when the organic fiber cord 82C of the finishing layer 8C contracts when the tire is discharged from the vulcanizer, the contraction stress does not act on the film 71 of the inner liner layer 7. That is, when the organic fiber cord 82C is not cut, the organic fiber cord 82C is fixed in the lower region of the bead core 5, while the end portion on the inner side in the tire axial direction of the organic fiber cord 82C is a free end. When the organic fiber cord 82C contracts, the inner liner layer 7 is pulled inward in the tire radial direction. In contrast, by cutting the organic fiber cord 82C at the above position, the displacement of the organic fiber cord 82C inward in the tire radial direction is suppressed. Thereby, the vulcanization failure of the inner liner layer 7 resulting from the finishing layer 8C can be reduced.

  FIG. 7 is a cross-sectional view showing a fourth embodiment of the finishing layer. In FIG. 7, the finishing layer 8D is composed of only the rubber composition 81D. Of course, in addition to the rubber component, it is possible to add compounding agents such as carbon black, a softening agent, a vulcanization accelerator, and an anti-aging agent to the rubber composition 81D.

  According to the above structure, since the finishing layer 8D does not include the textile of the organic fiber cord, the shrinkage stress generated by the finishing layer 8D when the tire is discharged from the vulcanizer can be minimized. Thereby, the vulcanization failure of the inner liner layer 7 resulting from the finishing layer 8D can be reduced.

  FIG. 8 is a sectional view showing a fifth embodiment of the finishing layer. In FIG. 8, the finishing layer 8E is composed of a rubber composition 81E and short fibers 83E blended in the rubber composition 81E. The average length L of the short fibers of the finishing layer 8E is 10 μm or more and 5000 μm or less, and the aspect ratio L / D between the average length L and the average diameter D is 10 or more and 500 or less. Short fibers having such an average length L and aspect ratio L / D are effective as a rubber reinforcing material.

  According to the above structure, since the finishing layer 8E does not include the textile of the organic fiber cord, it is possible to minimize the shrinkage stress generated by the finishing layer 8E when the tire is discharged from the vulcanizer. Thereby, the vulcanization failure of the inner liner layer 7 resulting from the finishing layer 8E can be reduced. Moreover, the finishing layer 8E can exhibit the function of protecting the base surface of the bead portion 3 in the same manner as when the textile of the organic fiber cord is embedded by blending the short fibers 83E defined by the above dimensions.

  In each of the above-described embodiments, the rubber compositions 81A to 81E constituting the finishing layers 8A to 8E have a Mooney viscosity at 100 ° C. in an unvulcanized state of 35 to 50 (preferably 40 to 45). The modulus at 100% elongation at 23 ° C. after vulcanization is 0.6 MPa to 1.3 MPa (preferably 0.7 MPa to 0.9 MPa), and the dynamic elastic modulus E ′ at 20 ° C. after vulcanization is A rubber composition having a pressure of 2.0 MPa to 5.5 MPa (preferably 2.5 MPa to 3.5 MPa) is used. Use of a soft rubber composition for the finishing layers 8A to 8E is advantageous in suppressing vulcanization failure. That is, by using a soft rubber composition for the finishing layers 8A to 8E, the destruction of the inner liner layer 7 and the peeling between the inner liner layer 7 and the finishing layers 8A to 8E can be avoided more reliably.

  Below, the film used by this invention is demonstrated. This film can be composed of a thermoplastic resin or a thermoplastic elastomer composition obtained by blending an elastomer in a thermoplastic resin.

  Examples of the thermoplastic resin used in the present invention include polyamide resins [for example, nylon 6 (N6), nylon 66 (N66), nylon 46 (N46), nylon 11 (N11), nylon 12 (N12), nylon 610 (N610), nylon 612 (N612), nylon 6/66 copolymer (N6 / 66), nylon 6/66/610 copolymer (N6 / 66/610), nylon MXD6, nylon 6T, nylon 6 / 6T copolymer, nylon 66 / PP copolymer, nylon 66 / PPS copolymer], polyester resin [for example, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyethylene isophthalate (PEI), polybutylene terephthalate / Tetramethylene glycol copolymer, PET PEI copolymer, polyarylate (PAR), polybutylene naphthalate (PBN), liquid crystal polyester, aromatic polyester such as polyoxyalkylene diimide diacid / polybutylene terephthalate copolymer], polynitrile resin [for example, polyacrylonitrile ( PAN), polymethacrylonitrile, acrylonitrile / styrene copolymer (AS), methacrylonitrile / styrene copolymer, methacrylonitrile / styrene / butadiene copolymer], poly (meth) acrylate resin [eg polymethacryl Acid methyl (PMMA), polyethyl methacrylate, ethylene ethyl acrylate copolymer (EEA), ethylene acrylic acid copolymer (EAA), ethylene methyl acrylate resin (EMA)], polyvinyl resin [for example, vinyl acetate (EVA), polyvinyl alcohol (PVA), vinyl alcohol / ethylene copolymer (EVOH), polyvinylidene chloride (PVDC), polyvinyl chloride (PVC), vinyl chloride / vinylidene chloride copolymer, vinylidene chloride / methyl acrylate Copolymer], cellulose resin [eg, cellulose acetate, cellulose acetate butyrate], fluorine resin [eg, polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polychlorofluoroethylene (PCTFE), tetrafluoroethylene / ethylene Copolymer (ETFE)], imide resin [for example, aromatic polyimide (PI)] and the like.

  Examples of the elastomer used in the present invention include diene rubbers and hydrogenated products thereof [for example, NR, IR, epoxidized natural rubber, SBR, BR (high cis BR and low cis BR), NBR, hydrogenated NBR, Hydrogenated SBR], olefin rubber [eg ethylene propylene rubber (EPDM, EPM), maleic acid modified ethylene propylene rubber (M-EPM)], butyl rubber (IIR), isobutylene and aromatic vinyl or diene monomer copolymer, Acrylic rubber (ACM), ionomer, halogen-containing rubber [for example, Br-IIR, Cl-IIR, brominated product of isobutylene paramethylstyrene copolymer (Br-IPMS), chloroprene rubber (CR), hydrin rubber (CHC, CHR), Chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), maleic acid-modified chlorinated polyethylene (M-CM)], silicone rubber (eg, methyl vinyl silicone rubber, dimethyl silicone rubber, methyl phenyl vinyl silicone rubber), sulfur-containing rubber (eg, polysulfide rubber), fluoro rubber (eg, Vinylidene fluoride rubber, fluorine-containing vinyl ether rubber, tetrafluoroethylene-propylene rubber, fluorine-containing silicone rubber, fluorine-containing phosphazene rubber), thermoplastic elastomer (eg, styrene elastomer, olefin elastomer, polyester elastomer, And urethane elastomers and polyamide elastomers).

  In the thermoplastic elastomer composition used in the present invention, the composition ratio of the thermoplastic resin component (A) and the elastomer component (B) may be appropriately determined depending on the balance of film thickness and flexibility, but the preferred range is 10/90 to 90/10, more preferably 20/80 to 85/15 (weight ratio).

  In the thermoplastic elastomer composition according to the present invention, in addition to the essential components (A) and (B), as a third component, other polymers such as a compatibilizer and a compounding agent can be mixed. The purpose of mixing other polymers is to improve the compatibility between the thermoplastic resin component and the elastomer component, to improve the film molding processability of the material, to improve heat resistance, to reduce costs, etc. Examples of the material used for this include polyethylene, polypropylene, polystyrene, ABS, SBS, and polycarbonate.

The thermoplastic elastomer composition is prepared by melt-kneading a thermoplastic resin and an elastomer (unvulcanized material in the case of rubber) in advance using a twin-screw kneading extruder or the like, and adding an elastomer component in the thermoplastic resin forming a continuous phase. It is obtained by dispersing. When the elastomer component is vulcanized, a vulcanizing agent may be added under kneading to dynamically vulcanize the elastomer. Further, various compounding agents (excluding the vulcanizing agent) to the thermoplastic resin or the elastomer component may be added during the kneading, but are preferably mixed in advance before kneading. The kneading machine used for kneading the thermoplastic resin and the elastomer is not particularly limited, and examples thereof include a screw extruder, a kneader, a Banbury mixer, and a biaxial kneading extruder. Among these, it is preferable to use a twin-screw kneading extruder for kneading the resin component and the rubber component and for dynamic vulcanization of the rubber component. Further, two or more types of kneaders may be used and kneaded sequentially. As conditions for melt-kneading, the temperature may be higher than the temperature at which the thermoplastic resin melts. The shear rate during kneading is preferably 2500 to 7500 sec ⁻¹ . The entire kneading time is from 30 seconds to 10 minutes, and when a vulcanizing agent is added, the vulcanization time after addition is preferably from 15 seconds to 5 minutes. The thermoplastic elastomer composition produced by the above method is formed into a film by molding with a resin extruder or calender molding. The method for forming a film may be a method of forming a film of a normal thermoplastic resin or thermoplastic elastomer.

  The thin film of the thermoplastic elastomer composition thus obtained has a structure in which the elastomer is dispersed as a discontinuous phase in a thermoplastic resin matrix. By adopting the dispersion structure in such a state, it is possible to set the Young's modulus in a range of 1 to 500 MPa and to impart appropriate rigidity as a tire constituent member.

  The thermoplastic resin or thermoplastic elastomer composition can be molded into a sheet or film and embedded alone in the tire, but an adhesive layer may be laminated to improve the adhesion to the adjacent rubber. good. Specific examples of the adhesive polymer constituting the adhesive layer include ultrahigh molecular weight polyethylene (UHMWPE), ethylene ethyl acrylate copolymer (EEA), ethylene methyl acrylate resin (EMA) having a molecular weight of 1 million or more, preferably 3 million or more. ), Acrylate copolymers such as ethylene acrylic acid copolymer (EAA) and their maleic anhydride adducts, polypropylene (PP) and its maleic acid modification, ethylene propylene copolymer and its maleic acid modification, Polybutadiene resin and its modified maleic anhydride, styrene-butadiene-styrene copolymer (SBS), styrene-ethylene-butadiene-styrene copolymer (SEBS), fluorine thermoplastic resin, polyester thermoplastic resin, etc. Can be mentioned. These can be extruded into a sheet form or a film form by a conventional method, for example, using a resin extruder. The thickness of the adhesive layer is not particularly limited, but it is preferable that the thickness is small for weight reduction of the tire, and 5 μm to 150 μm is preferable.

  In a pneumatic tire having a tire size of 195 / 65R15, an inner liner layer formed by sandwiching a film made of a thermoplastic elastomer composition in which an elastomer is blended with a thermoplastic resin from both sides is sandwiched between rubber layers from the carcass layer to the tire lumen side. Comparative Example 1 and Example in which the finishing layer that protects the base surface of the bead portion is arranged so that the end on the inner side in the tire axial direction overlaps the inner liner layer, and only the structure of the finishing layer is varied 1 to 6 tires were produced.

  The inner liner layer was obtained as follows. First, using a two-layer cylindrical molding apparatus, a peripheral length of 800 mm and a thickness of 55 μm having a laminated structure of a vinyl alcohol / ethylene copolymer (EVOH) film (thickness 5 μm) and a base material (thickness 50 μm). A cylindrical member was formed. Next, the cylindrical member was cut into a sheet having a width of 390 mm, and a rubber layer having a thickness of 0.2 mm was laminated on both surfaces of the film after the substrate was peeled, and this laminate was used as an inner liner layer.

  The tire of Comparative Example 1 uses a textile finishing layer, has a cord angle of 55 ° with respect to the tire circumferential direction of the finishing layer, and is arranged so that the inner liner layer is sandwiched between the finishing layer and the carcass layer.

  The tire of Comparative Example 2 uses a textile finishing layer, has a cord angle of 55 ° with respect to the tire circumferential direction of the finishing layer, and is disposed so as to be sandwiched between the inner liner layer and the carcass layer.

  The tire of Example 1 uses a textile finishing layer, the cord angle of the finishing layer with respect to the tire circumferential direction is 55 °, the inner liner layer is disposed so as to be sandwiched between the finishing layer and the carcass layer, and the inner liner A rubber sheet with a thickness of 0.5 mm is inserted between the layer and the finishing layer, and the thickness of the rubber part interposed between the film of the inner liner layer and the organic fiber cord of the finishing layer is 0.7 mm It is.

  The tire of Example 2 uses a textile finishing layer, the cord angle of the finishing layer with respect to the tire circumferential direction is 55 °, the finishing layer is disposed between the inner liner layer and the carcass layer, and the inner liner A rubber sheet with a thickness of 0.5 mm is inserted between the layer and the finishing layer, and the thickness of the rubber part interposed between the film of the inner liner layer and the organic fiber cord of the finishing layer is 0.7 mm It is.

  The tire of Example 3 uses a textile finishing layer, has a cord angle of 0 ° with respect to the tire circumferential direction of the finishing layer, and is arranged so that the inner liner layer is sandwiched between the finishing layer and the carcass layer.

  The tire of Example 4 uses a textile finishing layer, the cord angle of the finishing layer with respect to the tire circumferential direction is 55 °, and the inner liner layer is disposed between the finishing layer and the carcass layer, and the finishing layer The organic fiber cord is cut at a position that does not overlap with the film of the inner liner layer and at the inner side in the tire axial direction than the bead core.

  The tire of Example 5 uses a finishing layer composed only of a rubber composition, and is arranged so that the inner liner layer is sandwiched between the finishing layer and the carcass layer.

  The tire of Example 6 uses a finishing layer made of a rubber composition blended with short fibers, and is arranged so that an inner liner layer is sandwiched between the finishing layer and the carcass layer.

  In these Comparative Examples 1-2 and Examples 1-6, the rubber composition constituting the finishing layer has a Mooney viscosity of 40 at 100 ° C. in an unvulcanized state, and 100 at 23 ° C. after vulcanization. A rubber composition having a modulus at% elongation of 0.8 MPa and a dynamic elastic modulus E ′ at 20 ° C. after vulcanization of 3.0 MPa was used.

  After vulcanizing the tires of Comparative Examples 1 and 2 and Examples 1 to 6 having the above configuration with a vulcanizer, the tire is taken out from the vulcanizer, and the inner surface state of the tire is visually observed in the region where the finishing layer is present. The results are shown in Table 1. The evaluation results are indicated by “◯” when no vulcanization failure is observed, and by “X” when peeling is observed between the finishing layer and the inner liner layer.

  As apparent from Table 1, in the tires of Examples 1 to 6, no vulcanization failure of the inner liner layer due to the finishing layer was observed, but in the tires of Comparative Examples 1 and 2, the finishing layer and the inner liner There was peeling between the layers.

It is a meridian half section view showing a pneumatic tire according to an embodiment of the present invention. It is a meridian half sectional view showing a pneumatic tire according to another embodiment of the present invention. It is sectional drawing which shows the inner liner layer of the pneumatic tire in this invention. It is sectional drawing which shows 1st Embodiment of the finishing layer in this invention. It is a perspective sectional view showing a 2nd embodiment of a finishing layer in the present invention. It is sectional drawing which shows 3rd Embodiment of the finishing layer in this invention. It is sectional drawing which shows 4th Embodiment of the finishing layer in this invention. It is sectional drawing which shows 5th Embodiment of the finishing layer in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tread part 2 Side wall 3 Bead part 4 Carcass layer 5 Bead core 6 Belt layer 7 Inner liner layer 71 Film 72,73 Rubber layer 8,8A-8E Finishing layer 81A-81E Rubber composition 82A-81C Organic fiber cord 83E Short fiber 9 Rubber sheet

Claims (7)

  An inner liner layer constituted by sandwiching a film made of a thermoplastic elastomer composition or a thermoplastic elastomer composition obtained by blending an elastomer and a thermoplastic resin with rubber layers from both sides is arranged on the tire lumen side from the carcass layer, and the bead portion A pneumatic tire in which a finishing layer that protects the base surface is disposed so that an end on the inner side in the tire axial direction overlaps the inner liner layer, and when the tire is released from the vulcanizer as the finishing layer, A pneumatic tire comprising a finishing layer that generates a shrinkage stress that is smaller than a breaking strength of the inner liner layer and smaller than a delamination limit stress with the inner liner layer.   The finishing layer is composed of a rubber composition and an organic fiber cord textile embedded in the rubber composition, and the thickness of the rubber portion interposed between the film of the inner liner layer and the organic fiber cord of the finishing layer The pneumatic tire according to claim 1, wherein the tire is 0.5 mm to 3.0 mm.   The said finishing layer is comprised from the textile of the organic fiber cord embedded in the rubber composition and this rubber composition, The organic fiber cord of this finishing layer was arranged in the tire circumferential direction, The tire of Claim 1 characterized by the above-mentioned. Pneumatic tire.   The finishing layer is composed of a rubber composition and an organic fiber cord textile embedded in the rubber composition, the organic fiber cord of the finishing layer is arranged in a direction crossing the tire circumferential direction, and the organic fiber cord The pneumatic tire according to claim 1, wherein the tire is cut at a position that does not overlap the film of the inner liner layer and at a position inside the tire axial direction from the bead core.   The pneumatic tire according to claim 1, wherein the finishing layer is composed only of a rubber composition.   The finishing layer is composed of a rubber composition and short fibers blended in the rubber composition, the average length L of the short fibers of the finishing layer is 10 μm to 5000 μm, and the average length L and the average diameter D are The pneumatic tire according to claim 1, wherein an aspect ratio L / D is 10 or more and 500 or less.   As the rubber composition constituting the finishing layer, the Mooney viscosity at 100 ° C. in an unvulcanized state is 35-50, and the modulus at 100% elongation at 23 ° C. after vulcanization is 0.6 MPa-1. 7. The rubber composition according to claim 2, wherein the rubber composition is 3 MPa and has a dynamic elastic modulus E ′ at 20 ° C. after vulcanization of 2.0 MPa to 5.5 MPa. Pneumatic tire.

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