JP5488222B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire capable of improving tire durability performance while maintaining a tire mass within an allowable range.

  In recent years, with pneumatic tires applied to heavy trucks and buses, in order to reduce fuel consumption and reduce weight (improve transportation efficiency), tire mounting methods used for vehicle drive shafts and trailer shafts have been used in the past. The dual mounting method is shifting to the single mounting method.

  In such a single mounting type pneumatic tire, since the load load per one is large as compared with (a) a dual mounting type pneumatic tire, the calorific value of the tire tends to increase. In addition, (b) the region located on the inner side in the vehicle width direction when the tire is mounted on the vehicle is more susceptible to thermal failure because it is more susceptible to brake heat, engine heat, and the like than the portion outside the vehicle. Furthermore, in recent years, the demand for low-floor low-flat single tires with a flatness ratio of 55 or less is increasing. However, in such tires, the above trends (a) and (b) tend to appear. For this reason, the internal temperature of the tire rises, and the constituent members of the tire (for example, rubber materials and wires) may be oxidized or deteriorated by the air that has penetrated into the inside, and the durability performance of the tire may deteriorate.

  As a conventional pneumatic tire related to such a problem, a technique described in Patent Document 1 is known.

JP 2009-279977 A

  On the other hand, in a pneumatic tire, it is not preferable that the mass of the tire increases. Accordingly, an object of the present invention is to provide a pneumatic tire capable of improving tire durability performance while maintaining a tire mass within an allowable range.

  In order to achieve the above object, a pneumatic tire according to the present invention includes a first film layer made of a rubber material and a second film layer made of a thermoplastic resin or a thermoplastic elastomer composition obtained by blending an elastomer in a thermoplastic resin. A pneumatic tire including an inner liner formed on a tire inner peripheral surface, wherein the inner liner is formed by laminating the first film layer and the second film layer, and the second film layer is formed of a tire. It is characterized in that it is partially disposed in a predetermined region located on the inner side in the vehicle width direction than the tire equator line in a vehicle mounted state.

  In this pneumatic tire, (1) a second film layer having a low air permeability (lower air permeability than the first film layer made of butyl rubber) is partially disposed in a predetermined area, so that The air permeation prevention performance of the inner liner is enhanced. Thereby, the oxidation deterioration of the tire constituent member in this region is suppressed, and there is an advantage that the durability performance of the tire is improved. Further, (2) since the second film layer is partially disposed in the predetermined region, compared with a configuration in which the first film layer and the second film layer are disposed in the entire area of the tire inner circumferential surface, There is an advantage that the increase can be suppressed.

In addition, the pneumatic tire according to the present invention is provided on the inner side in the vehicle width direction of the tire equator line when the tire is attached to the prescribed rim and applied with the prescribed internal pressure and is attached to the vehicle and applied with the prescribed load. The average gauge G _Bi of the first film layer in the region, the average gauge G _Bo of the first film layer in the region outside the vehicle width direction, the average gauge G _Yi of the second film layer, and the first film layer The air permeability T _B of the second film layer and the air permeability T _Y of the second film layer have a relationship of (G _Bi / T _B + G _Yi / T _Y ) / (G _Bo / T _B ) ≧ 3.5. .

  In this pneumatic tire, since the air permeation prevention index of the inner liner in the arrangement region of the second film layer is appropriately increased, there is an advantage that the oxidative deterioration of the tire constituent member in this region can be effectively suppressed.

  The pneumatic tire according to the present invention includes an inner liner comprising a first film layer made of a rubber material and a second film layer made of a thermoplastic resin or a thermoplastic elastomer composition obtained by blending an elastomer in a thermoplastic resin. The inner liner is formed by laminating the first film layer and the second film layer, and the first film layer is in a vehicle-mounted state of the tire. It is partially disposed in a predetermined region located on the inner side in the vehicle width direction than the tire equator line.

  In this pneumatic tire, (1) the first film layer is partially disposed in a predetermined region, so that the air permeation prevention performance of the inner liner in this region is enhanced. Thereby, the oxidation deterioration of the tire constituent member in this region is suppressed, and there is an advantage that the durability performance of the tire is improved. Also, (2) since the first film layer is partially disposed in the predetermined region, compared with the configuration in which the first film layer and the second film layer are disposed in the entire area of the tire inner circumferential surface, There is an advantage that the increase can be suppressed.

In addition, the pneumatic tire according to the present invention has an average gauge _GBi of the first film layer when the tire is mounted on a specified rim and applied with a specified internal pressure and is mounted on a vehicle and applied with a specified load. And an average gauge _GYi of the second film layer in a region on the inner side in the vehicle width direction from the tire equator line, an average gauge G _Yo of the second film layer in a region on the outer side in the vehicle width direction, and the first film layer having an air permeability _{T B,} the air permeability _{T Y} of the second film _layer, the relation of _{(G Yi / T Y + G} Bi / T B) / (G Yo / T Y) ≧ 1.4 in .

  In this pneumatic tire, since the air permeation prevention index of the inner liner in the arrangement region of the first film layer appropriately increases, there is an advantage that the oxidative deterioration of the tire constituent member in this region can be effectively suppressed.

  The pneumatic tire according to the present invention includes an inner liner comprising a first film layer made of a rubber material and a second film layer made of a thermoplastic resin or a thermoplastic elastomer composition obtained by blending an elastomer in a thermoplastic resin. The inner liner has a single-layer structure in which the first film layer and the second film layer are arranged in the tire width direction, and the second film layer includes It is arranged on the inner side in the vehicle width direction when the tire is mounted on the vehicle.

  In this pneumatic tire, (1) a second film layer having a low air permeability (lower air permeability than the first film layer made of butyl rubber) is disposed in one side area of the tire, so that The air permeation prevention performance of the inner liner is enhanced. Thereby, the oxidation deterioration of the tire constituent member in this one side region is suppressed, and there is an advantage that the durability performance of the tire is improved. (2) Since the inner liner has a single-layer structure, an increase in tire mass can be suppressed as compared with a configuration in which the inner liner has a two-layer structure formed by laminating the first film layer and the second film layer. There are advantages.

  Further, the pneumatic tire according to the present invention is a pneumatic tire provided with an inner liner made of butyl rubber on the inner peripheral surface of the tire, and the tire is mounted on a specified rim to be applied with a specified internal pressure and mounted on a vehicle. When a specified load is applied, the average gauge of the inner liner in the region on the inner side in the vehicle width direction from the tire equator line is larger than the average gauge of the inner liner in the region on the outer side in the vehicle width direction than the tire equator line. It is characterized by.

  In this pneumatic tire, (1) the average gauge of the inner liner is set large in one side region of the tire, so that the air permeation prevention performance of the inner liner in this one side region is enhanced. Thereby, the oxidation deterioration of the tire constituent member in this one side region is suppressed, and there is an advantage that the durability performance of the tire is improved. Further, (2) since only one side region of the inner liner is formed thick, there is an advantage that an increase in tire mass can be suppressed compared to a configuration in which the entire region of the inner liner is uniformly formed thick. is there.

Moreover, the pneumatic tire according to the present invention, the average gauge G _Bi of the inner liner in a region from the tire width direction inner end of belt edge cushion to the end portion in the tire radial direction outer side of the bead filler, the tire equator line The average gauge G _{Bo of the} inner liner in the region outside in the vehicle width direction has a relationship of 1.2 ≦ G _Bi / G _Bo .

Since this pneumatic tire, an air permeation preventive index of the inner liner is increased properly at the thick portion (portion to be the average gauge G _Bi), effectively suppress the oxidation degradation of the thick portion definitive tire component There are advantages you can do.

  The pneumatic tire according to the present invention has a tire nominal width of 355 [mm] or more, a tire flatness of 55 [%] or less, a rim diameter of a specified rim of 17.5 [inch] or more, and a single tire Applicable to heavy-duty tires that use the mounting method.

  By applying the configuration of the pneumatic tire to such a heavy duty tire, there is an advantage that the effect of suppressing the oxidative deterioration of the tire constituent member can be remarkably obtained.

  The pneumatic tire according to the present invention has an advantage that the tire durability performance can be improved while maintaining the tire mass within an allowable range.

FIG. 1 is a cross-sectional view in the tire meridian direction showing a pneumatic tire according to Embodiment 1 of the present invention. FIG. 2 is a sectional view in the tire meridian direction showing a pneumatic tire according to Embodiment 2 of the present invention. FIG. 3 is a sectional view in the tire meridian direction showing a pneumatic tire according to Embodiment 3 of the present invention. 4 is a sectional view in the tire meridian direction showing a pneumatic tire according to Embodiment 4 of the present invention. FIG. 5 is a table showing the results of the performance test of the pneumatic tire according to the embodiment of the present invention. FIG. 6 is a table showing the results of the performance test of the pneumatic tire according to the embodiment of the present invention.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. Further, the constituent elements of this embodiment include those that can be replaced while maintaining the identity of the invention and that are obvious for replacement. In addition, a plurality of modifications described in this embodiment can be arbitrarily combined within a range obvious to those skilled in the art.

[Pneumatic tire]
The pneumatic tire 1 includes a bead core 2, a bead filler 3, a carcass layer 4, a belt layer 5, a tread rubber 6, a side wall rubber 7, and an inner liner 8 (FIG. 1). reference). The bead core 2 has an annular structure and is configured as a pair of left and right. The bead filler 3 is disposed on the outer periphery of the bead core 2 in the tire radial direction and reinforces the bead portion of the tire. The carcass layer 4 is bridged in a toroidal shape between the left and right bead cores 2 and 2 to constitute a tire skeleton. Further, both end portions of the carcass layer 4 are folded and locked outward in the tire width direction so as to wrap the bead filler 3. The belt layer 5 includes a plurality of stacked belt members 51 to 53 and is disposed on the outer periphery in the tire radial direction of the carcass layer 4. The tread rubber 6 is disposed on the outer circumference in the tire radial direction of the carcass layer 4 and the belt layer 5 to constitute a tread portion of the tire. The sidewall rubber 7 is configured as a pair of left and right sides, and is disposed on the outer side in the tire width direction of the carcass layer 4 to constitute a sidewall portion of the tire. The inner liner 8 is disposed to be bonded to the inner peripheral surface of the carcass layer 4.

[Inner liner]
In recent years, with pneumatic tires applied to heavy trucks and buses, in order to reduce fuel consumption and reduce weight (improve transportation efficiency), tire mounting methods used for vehicle drive shafts and trailer shafts have been used in the past. The dual mounting method is shifting to the single mounting method.

  In such a single mounting type pneumatic tire, since the load load per one is large as compared with (a) a dual mounting type pneumatic tire, the calorific value of the tire tends to increase. In addition, (b) the region located on the inner side in the vehicle width direction when the tire is mounted on the vehicle is more susceptible to thermal failure because it is more susceptible to brake heat, engine heat, and the like than the portion outside the vehicle. Furthermore, in recent years, the demand for low-floor low-flat single tires with a flatness ratio of 55 or less is increasing. However, in such tires, the above trends (a) and (b) tend to appear. For this reason, the internal temperature of the tire rises, and the constituent members of the tire (for example, rubber materials and wires) may be oxidized or deteriorated by the air that has penetrated into the inside, and the durability performance of the tire may deteriorate.

  On the other hand, in a pneumatic tire, it is not preferable that the mass of the tire increases.

  Therefore, in the pneumatic tire 1, the inner liner 8 has the following structure in order to improve the tire durability performance while maintaining the tire mass within an allowable range (see FIGS. 1 to 4).

  FIG. 1 is a cross-sectional view in the tire meridian direction showing a pneumatic tire according to Embodiment 1 of the present invention.

  In the pneumatic tire 1 of Example 1, the inner liner 8 includes a first film layer 81 made of a rubber material, and a second film made of a thermoplastic elastomer composition obtained by blending a thermoplastic resin or an elastomer into a thermoplastic resin. And is disposed on the inner circumferential surface of the tire. The inner liner 8 is configured by laminating a first film layer 81 and a second film layer 82. Further, the second film layer 82 is partially disposed in a predetermined region located on the inner side in the vehicle width direction from the tire equator line when the tire is mounted on the vehicle.

  For example, in the first embodiment, the inner liner 8 has a two-layer structure in which a first film layer 81 and a second film layer 82 are laminated, and the first film layer 81 is on the tire inner side, and the carcass is formed. It is affixed and arrange | positioned at the internal peripheral surface of the layer 4 (refer FIG. 1). The first film layer 81 is made of butyl rubber, and is arranged over the entire area of the tire inner peripheral surface to constitute the tire inner peripheral surface. Further, the second film layer 82 is disposed so as to be sandwiched between the first film layer 81 and the carcass layer 4. In addition, the second film layer 82 is one region having the tire equator line CL as a boundary in a cross-sectional view in the tire meridian direction (a region on the inner side in the vehicle width direction of the tire equator line when the tire is mounted on the vehicle). Only partially arranged. Specifically, the second film layer 82 is formed from the shoulder portion to the sidewall portion (more specifically, the tire of the bead filler 3 from the inner end in the tire width direction of the belt edge cushion 9 in one side region of the tire. It is arranged over the radially outer end).

  In the above configuration, in the laminated structure of the first film layer 81 and the second film layer 82, the second film layer 82 may be disposed on the inner side in the tire radial direction than the first film layer 81.

  In this configuration, (1) the second film layer 82 having a low air permeability (lower air permeability than the first film layer 81 made of butyl rubber) is partially disposed in the predetermined area, so that The air permeation prevention performance of the inner liner 8 is enhanced. Thereby, the oxidation deterioration of the tire constituent member in this region is suppressed, and there is an advantage that the durability performance of the tire is improved. In particular, in a region located on the inner side in the vehicle width direction of the tire equator line when the tire is mounted on the vehicle, there is a problem that oxidation deterioration of the tire constituent member easily occurs due to the influence of brake heat, engine heat, and the like. Therefore, the region where the second film layer 82 is disposed is positioned on the inner side in the vehicle width direction when the tire is mounted on the vehicle, and thus there is an advantage that the oxidative deterioration of the tire constituent member can be effectively suppressed. (2) Since the second film layer 82 is partially disposed in the predetermined region, the tire mass is compared with the configuration in which the first film layer and the second film layer are disposed in the entire area of the tire inner peripheral surface. There is an advantage that the increase of can be suppressed.

In Example 1, as described above, the first film layer 81 is made of butyl rubber. Air permeability _{T B} of such butyl rubber is ^{4.5~5.5 × 10 -9 [cc · cm} / cm 3 · sec · cmHg], compared with the rubber material of the general used such as a tread rubber 6 And small. Therefore, the first film layer 81 and the second film layer 82 are laminated to form the inner liner 8, which is preferable in that the air permeation prevention performance of the inner liner 8 is further improved.

  However, the present invention is not limited thereto, and the first film layer 81 may be a rubber material that can be used for a pneumatic tire. For example, the first film layer 81 is made of natural rubber (NR), isoprene rubber (IR), epoxidized natural rubber, styrene butadiene rubber (SBR), butadiene rubber (BR, high cis BR and low cis BR), nitrile rubber ( NBR), halogenated butyl rubber, and other diene rubbers.

Moreover, in this pneumatic tire 1, as described above, the second film layer 82 is composed of a thermoplastic resin or a thermoplastic elastomer composition obtained by blending an elastomer in a thermoplastic resin. Such air permeability _{T Y} of the second film layer 82 is ^{1.5~3.0 × 10 -11 [cc · cm} / cm 3 · sec · cmHg], the first film layer 81 made of butyl rubber It is small compared with the air permeability. Therefore, it is preferable that the second film layer 82 is disposed in a predetermined region of the inner liner 8 to suppress oxidative deterioration of the tire constituent member in this region.

  Examples of the thermoplastic resin used for the second film layer 82 include polyamide-based 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 Cole 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 resins [for example, polymethyl methacrylate (PMMA), polyethyl methacrylate, ethylene ethyl acrylate copolymer (EEA), ethylene acrylic acid copolymer (EAA), ethylene methyl acrylate resin (EMA)], polyvinyl chloride 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], fluororesin [eg polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), polychlorofluoroethylene (PCTFE) , Tetrafluoroethylene / ethylene copolymer (ETFE)], imide resins [for example, aromatic polyimide (PI)], and the like.

  Examples of the elastomer used for the second film layer 82 include diene rubber 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 system Monomer copolymer, acrylic rubber (ACM), ionomer, halogen-containing rubber [for example, bromide of Br-IIR, Cl-IIR, 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), fluorine Rubber (for example, vinylidene fluoride rubber, fluorine-containing vinyl ether rubber, tetrafluoroethylene-propylene rubber, fluorine-containing silicon rubber, fluorine-containing phosphazene rubber), thermoplastic elastomer (for example, styrene elastomer, olefin elastomer, polyester) -Based elastomers, urethane-based elastomers, polyamide-based elastomers).

  Moreover, in the thermoplastic elastomer composition used for the second film layer 82, the composition ratio of the thermoplastic resin component (A) and the elastomer component (B) may be appropriately determined depending on the balance of the thickness and flexibility of the film. However, the preferred range is 10/90 to 90/10, more preferably 20/80 to 85/15 (mass ratio).

  In addition to the essential components (A) and (B), other polymers and compounding agents such as a compatibilizer can be mixed in the thermoplastic elastomer composition as a third component. 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.

In addition, such a thermoplastic elastomer composition is prepared by previously melting and kneading a thermoplastic resin and an elastomer (unvulcanized product in the case of rubber) with a twin-screw kneading extruder or the like to form a continuous phase. It is obtained by dispersing the elastomer component. 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 component 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. Moreover, it is preferable that the shear rate at the time of kneading | mixing is 2500-7500 [sec ^<-2 >]. 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.

Further, in the pneumatic tire 1, when the tire is mounted on the specified rim and applied with the specified internal pressure, and is mounted on the vehicle and applied with the specified load, the region on the inner side in the vehicle width direction from the tire equator line CL. in average gauge G _Bi of the first film layer 81, and the average gauge G _Bo of the first film layer 81 in the vehicle width direction outer region, the average gauge G _Yi of the second film layer 82, the first film layer 81 The air permeability T _B and the air permeability T _Y of the second film layer 82 have a relationship of (G _Bi / T _B + G _Yi / T _Y ) / (G _Bo / T _B ) ≧ 3.5. Is preferred (see FIG. 1).

In such a configuration, the air permeation prevention index RA (= (G _Bi / T _B + G _Yi / T _Y ) / (G _Bo / T _B )) of the inner liner 8 in the arrangement region of the second film layer 82 is appropriately increased. Therefore, there is an advantage that oxidation deterioration of the tire constituent member in this region can be effectively suppressed.

Moreover, although the air permeation | prevention prevention index RA is so preferable that it is large, the upper limit is _GYi <= 0.5, for example. The air permeability was measured under the conditions of test gas: air (N ₂ = 0 ₂ = 8: 2), test temperature: 30 ° C., J1S K7126 “Plastic film and sheet gas permeability test method (Method A) ) ".

  The specified rim refers to “applied rim” defined in JATMA, “Design Rim” defined in TRA, or “Measuring Rim” defined in ETRTO. The specified internal pressure means “maximum air pressure” defined by JATMA, the maximum value of “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined by TRA, or “INFLATION PRESSURES” defined by ETRTO. The specified load means the “maximum load capacity” defined by JATMA, the maximum value of “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined by TRA, or “LOAD CAPACITY” defined by ETRTO.

The average gauge G _Yi of the second film layer 82 is, for example, a pitch of 10 [mm] from the end of the belt edge cushion 9 in the tire width direction toward the end of the bead filler 3 in the tire radial direction. It is calculated by measuring the gauge.

  FIG. 2 is a sectional view in the tire meridian direction showing a pneumatic tire according to Embodiment 2 of the present invention. In the figure, the same components as those of the pneumatic tire 1 of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The pneumatic tire 1 of Example 2 is common to the pneumatic tire 1 of Example 1 in that the inner liner 8 is configured by laminating a first film layer 81 and a second film layer 82 (FIG. 1 and FIG. 2). On the other hand, in the pneumatic tire 1 of the second embodiment, the first film layer 81 is partially disposed in a predetermined region located on the inner side in the vehicle width direction of the tire equator line CL when the tire is mounted on the vehicle. The second film layer 82 is different from the pneumatic tire 1 of the first embodiment in which the second film layer 82 is partially disposed in a predetermined region.

  For example, in this Example 2, the pneumatic tire 1 has the structure which replaced the 1st film layer 81 and the 2nd film layer 82 in the pneumatic tire 1 of Example 1 (refer FIG. 2). . That is, the inner liner 8 has a two-layer structure in which a first film layer 81 and a second film layer 82 are laminated, and the inner peripheral surface of the carcass layer 4 with the second film layer 82 on the tire inner side. It is pasted and arranged. At this time, the second film layer 82 is disposed over the entire area of the tire inner peripheral surface to constitute the tire inner peripheral surface. On the contrary, the first film layer 81 is sandwiched and disposed between the second film layer 82 and the carcass layer 4. In addition, the first film layer 81 has one region with the tire equator line CL as a boundary in a cross-sectional view in the tire meridian direction (a region located inward of the tire equator line in the vehicle width direction when the tire is mounted on the vehicle). Only partially arranged. Specifically, the first film layer 81 is formed from the shoulder portion to the sidewall portion (more specifically, the tire of the bead filler 3 from the inner end in the tire width direction of the belt edge cushion 9 in one side region of the tire. It is arranged over the radially outer end).

  In the above configuration, in the laminated structure of the first film layer 81 and the second film layer 82, the first film layer 81 may be disposed on the inner side in the tire radial direction than the second film layer 82.

  In such a configuration, (1) the first film layer 81 is partially disposed in a predetermined region, so that the air permeation prevention performance of the inner liner 8 in this region is enhanced. Thereby, the oxidation deterioration of the tire constituent member in this region is suppressed, and there is an advantage that the durability performance of the tire is improved. In particular, in a region located on the inner side in the vehicle width direction of the tire equator line when the tire is mounted on the vehicle, there is a problem that oxidation deterioration of the tire constituent member easily occurs due to the influence of brake heat, engine heat, and the like. Therefore, the region where the first film layer 81 is disposed is located on the inner side in the vehicle width direction when the tire is mounted on the vehicle, and thus there is an advantage that the oxidative deterioration of the tire constituent member can be effectively suppressed. (2) Since the first film layer 81 is partially disposed in the predetermined region, the tire mass is compared with the configuration in which the first film layer and the second film layer are disposed over the entire inner circumferential surface of the tire. There is an advantage that the increase of can be suppressed.

Further, in the pneumatic tire 1, when the tire is attached to the prescribed rim and applied with the prescribed internal pressure and is attached to the vehicle and the prescribed load is applied, the average gauge _GBi of the first film layer 81, The average gauge G _Yi of the second film layer 82 in the inner region in the vehicle width direction from the tire equator line CL, the average gauge G _Yo of the second film layer 82 in the outer region in the vehicle width direction, and the first film layer 81 The air permeability T _B and the air permeability T _Y of the second film layer 82 have a relationship of (G _Yi / T _Y + G _Bi / T _B ) / (G _Yo / T _Y ) ≧ 1.4. Is preferred (see FIG. 2).

In such a configuration, the air permeation prevention index RA (= (G _Yi / T _Y + G _Bi / T _B ) / (G _Yo / T _Y )) of the inner liner 8 in the arrangement region of the first film layer 81 is appropriately increased. Therefore, there is an advantage that oxidation deterioration of the tire constituent member in this region can be effectively suppressed.

  FIG. 3 is a sectional view in the tire meridian direction showing a pneumatic tire according to Embodiment 3 of the present invention. In the figure, the same components as those of the pneumatic tire 1 of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In this pneumatic tire 1, the inner liner 8 has a single-layer structure in which a first film layer 81 and a second film layer 82 are arranged in the tire width direction (see FIG. 3). And the 2nd film layer 82 is arrange | positioned inside a vehicle width direction in the vehicle mounting state of a tire.

  For example, in the third embodiment, the inner liner 8 is configured by aligning and bonding a first film layer 81 and a second film layer 82 in the tire width direction (see FIG. 3). Further, the inner liner 8 is disposed by being bonded to the inner peripheral surface of the carcass layer 4 so that the first film layer 81 and the second film layer 82 are symmetric with respect to the tire equator line CL. At this time, the 1st film layer 81 and the 2nd film layer 82 are arrange | positioned over the one side whole region of a tire internal peripheral surface by extending to the downward direction of the bead cores 2 and 2, respectively. Further, the second film layer 82 is located on the inner side in the vehicle width direction when the tire is mounted on the vehicle.

  In such a configuration, (1) the second film layer 82 having a low air permeability (lower air permeability than the first film layer 81 made of butyl rubber) is disposed in one side area of the tire, so that The air permeation prevention performance of the inner liner 8 is enhanced. Thereby, the oxidation deterioration of the tire constituent member in this one side region is suppressed, and there is an advantage that the durability performance of the tire is improved. In particular, in a region located on the inner side in the vehicle width direction of the tire equator line when the tire is mounted on the vehicle, there is a problem that oxidation deterioration of the tire constituent member easily occurs due to the influence of brake heat, engine heat, and the like. Therefore, the region where the second film layer 82 is disposed is positioned on the inner side in the vehicle width direction when the tire is mounted on the vehicle, and thus there is an advantage that the oxidative deterioration of the tire constituent member can be effectively suppressed. (2) Since the inner liner 8 has a single-layer structure, an increase in tire mass is suppressed compared to a structure in which the inner liner has a two-layer structure formed by laminating a first film layer and a second film layer. There are advantages you can do.

  In addition, the 1st film layer 81 and the 2nd film layer 82 may be partially overlapped for bonding at the boundary part. In such a configuration, it is preferable that the number of overlapping portions is smaller because the inner liner 8 is lighter and an increase in tire mass can be suppressed. For example, it is preferable that the overlapping portion of the first film layer 81 and the second film layer 82 be within a region on the inner side in the tire width direction than the shoulder portion (the end portion on the inner side in the tire width direction of the belt edge cushion 9). .

  4 is a sectional view in the tire meridian direction showing a pneumatic tire according to Embodiment 4 of the present invention. In the figure, the same components as those of the pneumatic tire 1 of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In this pneumatic tire 1, the inner liner 8 is made of butyl rubber (see FIG. 4). The average gauge of the inner liner 8 in the inner region in the vehicle width direction from the tire equator line CL when the tire is mounted on the specified rim and applied with the specified internal pressure and is applied to the vehicle and applied with the specified load. Is larger than the average gauge of the inner liner 8 in the region outside the tire equator line CL in the vehicle width direction.

  For example, in this Example 4, the inner liner 8 has a single-layer structure made only of butyl rubber (first film layer 81), and is affixed to the inner peripheral surface of the carcass layer 4 so as to cover the entire inner peripheral surface of the tire. It extends across. Further, in the tire meridian cross-sectional view, the inner liner 8 is a region on one side of the tire from the shoulder portion to the sidewall portion (more specifically, the end of the belt edge cushion 9 on the inner side in the tire width direction). A thick portion 83 is provided in a region from the first portion to the end of the bead filler 3 on the outer side in the tire radial direction. Due to the thick portion 83, the average gauge of the inner liner 8 in the region on the inner side in the vehicle width direction from the tire equator line is larger than the average gauge in the region on the outer side in the vehicle width direction. The thick portion 83 may be configured by laminating another butyl rubber sheet on the base butyl rubber sheet, or may be configured by extrusion so that a part of the butyl rubber sheet is thick. .

  In such a configuration, (1) the average gauge of the inner liner 8 is set large in the one side region of the tire, so that the air permeation prevention performance of the inner liner 8 in the one side region is enhanced. Thereby, the oxidation deterioration of the tire constituent member in this one side region is suppressed, and there is an advantage that the durability performance of the tire is improved. In particular, in a region located on the inner side in the vehicle width direction of the tire equator line when the tire is mounted on the vehicle, there is a problem that oxidation deterioration of the tire constituent member easily occurs due to the influence of brake heat, engine heat, and the like. Therefore, there is an advantage that the oxidation deterioration of the tire constituent member can be effectively suppressed by positioning the side with the larger average gauge of the inner liner 8 on the inner side in the vehicle width direction when the tire is mounted on the vehicle. Further, (2) since only one side region of the inner liner 8 is formed thick, an advantage that an increase in tire mass can be suppressed as compared with a configuration in which the entire region of the inner liner is uniformly formed thick. There is.

Incidentally, in the pneumatic tire 1, the average gauge G _Bi of the inner liner 8 in the region from the tire width direction inner end of belt edge cushion 9 to the end portion in the tire radial direction outer side of the bead filler 3, a tire equator line It is preferable that the average gauge G _Bo of the inner liner 8 in the region on the outer side in the vehicle width direction from CL has a relationship of 1.2 ≦ G _Bi / G _Bo .

In such a configuration, since the air permeation preventive index RA of the thick portion 83 (average gauge G _Bi portion serving) in the inner liner 8 is increased appropriately, effective oxidative degradation of the thick portion 83 definitive tire component There is an advantage that can be suppressed.

In the above configuration, it is more preferable that the inner liner 8 has a relationship of G _Bi / G _Bo ≦ 2.0. Thereby, there is an advantage that the mass difference between the right and left tires is alleviated and the riding performance of the tire is properly maintained. For example, if 2.0 <G _Bi / G _Bo , the mass difference between the left and right tires becomes excessive, and the generated vibration increases, which may deteriorate the riding comfort performance of the tire.

The average gauge G _Bi of the thick portion 83 is, for example, towards the end of the outer side in the tire radial direction of the bead filler 3 the ends of the tire width direction inner side of the belt edge cushion 9 as a starting point 10 in [mm] Pitch Calculated by measuring the gauge.

[Applicable to]
For heavy-duty tires that have a nominal tire width of 355 [mm] or more, a tire flatness of 55 [%] or less, a rim diameter of a specified rim of 17.5 [inch] or more, and a single mounting method, There is a problem that the amount of heat generated by the tire is likely to increase because the load load per tire is large as compared with a pneumatic tire of a mounting method. Therefore, by applying the configuration of the pneumatic tire 1 (see FIGS. 1 to 4) to such a heavy duty tire, there is an advantage that the effect of suppressing the oxidative deterioration of the tire constituent member can be obtained remarkably.

[performance test]
5 and 6 are tables showing the results of the performance test of the pneumatic tire according to the embodiment of the present invention. In this embodiment, a performance test related to durability performance was performed on a plurality of pneumatic tires with different conditions, and the tire mass was measured.

  In the performance test regarding the durability performance, a pneumatic tire having a tire size of 445 / 50R22.5 is assembled to a rim having a rim size of 22.5 × 14.00, and an internal pressure of 830 [kPa] and a load of 63.50 [kN] are attached to the pneumatic tire. ] Is loaded. A pneumatic tire is disposed in a cover simulating a tire house and attached to an indoor drum testing machine. Then, the travel distance until the tire breaks is measured at a speed of 45 [km / h], and based on the measurement result, index evaluation is performed with the conventional example 1 as a reference (100). This evaluation is more preferable as the numerical value is larger, and can be said to be superior at 105 or more.

  The tire mass is an index evaluation based on Conventional Example 2 (100). In this evaluation, the smaller the value, the better. If it is 105 or less, it can be said that it is within the allowable range.

In the pneumatic tire of Conventional Example 1, the inner liner has a single-layer structure (only the first film layer) made of butyl rubber, and has a uniform gauge (G _Bi = G _Bo = 2.0 [mm]). (Not shown). The air permeability _{T B} of the inner liner (butyl rubber) is ^{5.0 × 10 -9 [cc · cm} / cm 3 · sec · cmHg].

In the pneumatic tire of Conventional Example 2, the inner liner has a two-layer structure in which a first film layer made of butyl rubber and a second film layer made of a thermoplastic resin are laminated. Both of the two film layers extend over the entire area of the tire inner peripheral surface (not shown). The first film layer has a uniform gauge (G _Bi = G _Bo = 2.0 [mm]), and the second film layer has a uniform gauge (G _Yi = G _Yo = 0.03). [Mm]). The air permeability _{T B} of the first film layer (rubber) is a ^{5.0 × 10 -9 [cc · cm} / cm 3 · sec · cmHg], air of the second film layer (thermoplastic resin) transmittance _{T Y} is a ^{0.03 × 10 -9 [cc · cm} / cm 3 · sec · cmHg].

In the pneumatic tire 1 of Examples 1-1 to 1-3, the inner liner 8 has a two-layer structure in which a first film layer 81 made of butyl rubber and a second film layer 82 made of a thermoplastic resin are laminated. (See FIG. 1). However, the 2nd film layer 82 is partially arrange | positioned only to the area | region from the edge part of the tire width direction inner side of the belt edge cushion 9 to the edge part of the tire radial direction outer side of the bead filler 3 only in one side area | region. In this respect, it is different from the pneumatic tire of Conventional Example 2. The pneumatic tire 1 is attached to the indoor drum testing machine with the second film layer 82 side facing the tire house (cover) side. The first film layer 81 has a uniform gauge (G _Bi = G _Bo = 2.0 [mm]), and the second film layer 82 has a uniform gauge (G _Yi = 0.03 [ mm], 0.10 [mm] or 0.50 [mm]). Further, in the pneumatic tires 1 of Examples 1-1 to 1-3, the gauges G _Yi of the second film layer 82 are different, and thus the air transmission of the inner liner 8 at the installation position of the second film layer 82 is different. protection factor _{RA (= (G Bi / T} B + G Yi / T Y) / (G Bo / T B) ≧ 3.5) is different from. The air permeability T _Y air permeability T _B and the second film layer 82 of the first film layer 81 is the same as the conventional example 2.

In the pneumatic tire 1 of Examples 2-1 to 2-3, the inner liner 8 has a two-layer structure in which a first film layer 81 made of butyl rubber and a second film layer 82 made of a thermoplastic resin are laminated. (See FIG. 2). However, the 1st film layer 81 is partially arrange | positioned only to the area | region from the edge part of the tire width direction inner side of the belt edge cushion 9 to the edge part of the tire radial direction outer side of the bead filler 3 only in one side area | region. In this respect, it is different from the pneumatic tire of Conventional Example 2. The pneumatic tire 1 is attached to the indoor drum testing machine with the first film layer 81 side facing the tire house (cover) side. The first film layer 81 has a uniform gauge (G _Bi = 2.0 [mm], 3.0 [mm] or 4.0 [mm]), and the second film layer 82 Various gauges (G _Yi = G _Yo = 0.03 [mm]). In the pneumatic tire 1 of the embodiment 2-1 to 2-3, the gauge _{G Bi} the phase of the first film layer 81 cradling, Therefore, the air permeability of the inner liner 8 at the installation position of the first film layer 81 protection factor _{RA (= (G Yi / T} Y + G Bi / T B) / (G Yo / T Y) ≧ 1.4 is different from. the air permeability of the first film layer 81 _{T B} and the second air permeability T _Y of the film layer 82 is the same as the conventional example 2.

In the pneumatic tire 1 of Example 3, the inner liner 8 is configured by laminating a first film layer 81 made of butyl rubber and a second film layer 82 made of a thermoplastic resin side by side in the tire width direction (see FIG. 3). The inner liner 8 has a structure in which the first film layer 81 and the second film layer 82 are arranged symmetrically with respect to the tire equator line CL. Moreover, the 1st film layer 81 and the 2nd film layer 82 are each extended in the one side whole region of a tire internal peripheral surface. The pneumatic tire 1 is attached to the indoor drum testing machine with the second film layer 82 side facing the tire house (cover) side. The air permeability T _Y air permeability T _B and the second film layer 82 of the first film layer 81 is the same as the conventional example 2.

In the pneumatic tires 1 of Examples 4-1 to 4-3, the inner liner 8 has a single-layer structure made only of butyl rubber (first film layer 81) (see FIG. 4). Further, the inner liner 8 has a thick portion 83 only in one side region and in a region from the inner end in the tire width direction of the belt edge cushion 9 to the outer end in the tire radial direction of the bead filler 3. Further, in the pneumatic tire 1 of Examples 4-1 to 4-3, the gauge of the thick portion 83 (G _Bi = 2.4 [mm], 3.2 [mm] or 4.0 [mm]) Therefore, the air permeation prevention index RA of the inner liner 8 at the position of the thick portion 83 is different. The pneumatic tire 1 is attached to the indoor drum testing machine with the thick portion 83 side facing the tire house (cover) side. The air permeability T _B of the butyl rubber is the same as the conventional example 1.

  As shown in the test results, in the pneumatic tires 1 of Examples 1-1 to 4-3, it can be seen that the tire durability performance can be improved while maintaining the tire mass within an allowable range (see FIGS. 5 and 6). . Further, when Examples 1-1 to 1-3, Examples 2-1 to 2-3, or Examples 4-1 to 4-3 are compared, the tire durability performance is improved by increasing the air permeation prevention index RA. I understand that.

  As described above, the pneumatic tire according to the present invention is useful in that the tire durability performance can be improved while maintaining the tire mass within an allowable range.

DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Bead core 3 Bead filler 4 Carcass layer 5 Belt layer 51-53 Belt material 6 Tread rubber 7 Side wall rubber 8 Inner liner 9 Belt edge cushion 81 First film layer 82 Second film layer 83 Thick part

Claims (8)

A pneumatic tire comprising an inner liner comprising a first film layer made of a rubber material and a second film layer made of a thermoplastic elastomer or a thermoplastic elastomer composition obtained by blending an elastomer in a thermoplastic resin on a tire inner peripheral surface. There,
The inner liner is formed by laminating the first film layer and the second film layer, and the second film layer is a predetermined region located on the inner side in the vehicle width direction of the tire equator line when the tire is mounted on the vehicle. A pneumatic tire characterized in that it is partially disposed on the tire. The average gauge G of the first film layer in the region on the inner side in the vehicle width direction from the tire equator line when the tire is mounted on the specified rim and applied with the specified internal pressure and is applied to the vehicle and applied with the specified load. and _Bi, and the average gauge G _Bo of the first film layer in the vehicle width direction outer region, the average gauge G _Yi of the second film layer, and the air permeability T _B of the first film layer, the second and air permeability _{T Y} of the film _layer, the pneumatic tire according to claim 1 having a relationship of _{(G Bi / T B + G} Yi / T Y) / (G Bo / T B) ≧ 3.5. A pneumatic tire comprising an inner liner comprising a first film layer made of a rubber material and a second film layer made of a thermoplastic elastomer or a thermoplastic elastomer composition obtained by blending an elastomer in a thermoplastic resin on a tire inner peripheral surface. There,
The inner liner is formed by laminating the first film layer and the second film layer, and the first film layer is located in a vehicle width direction inside of the tire equator line when the tire is mounted on the vehicle. A pneumatic tire characterized in that it is partially disposed on the tire. When the tire is mounted on the specified rim and applied with the specified internal pressure and mounted on the vehicle and applied with the specified load, the average gauge _GBi of the first film layer and the inner side in the vehicle width direction than the tire equator line the average gauge G _Yi of the in the region the second film layer, and the average gauge G _Yo of said second film layer in the vehicle width direction outer region, the air permeability T _B of the first film layer, the second and air permeability _{T Y} of the film _layer, the pneumatic tire according to claim 3 having a relationship of _{(G Yi / T Y + G} Bi / T B) / (G Yo / T Y) ≧ 1.4. A pneumatic tire comprising an inner liner comprising a first film layer made of a rubber material and a second film layer made of a thermoplastic elastomer or a thermoplastic elastomer composition obtained by blending an elastomer in a thermoplastic resin on a tire inner peripheral surface. There,
The inner liner has a single layer structure in which the first film layer and the second film layer are arranged in the tire width direction, and the second film layer is disposed on the inner side in the vehicle width direction when the tire is mounted on the vehicle. A pneumatic tire characterized by that. A pneumatic tire provided with an inner liner made of butyl rubber on a tire inner peripheral surface,
When the tire is mounted on the specified rim and applied with the specified internal pressure and is mounted on the vehicle and applied with the specified load, the average gauge of the inner liner in the region in the vehicle width direction from the tire equator line is the tire equator. A pneumatic tire characterized by being larger than an average gauge of the inner liner in a region outside the line in the vehicle width direction. Wherein the belt edge average gauge G _Bi of the inner liner in a region from the end portion in the tire width direction inner side to the end portion of the outer side in the tire radial direction of the bead filler of the cushion, in the vehicle width direction outer region than the tire equator line Inner The pneumatic tire according to claim 6, wherein the liner average gauge G _Bo has a relationship of 1.2 ≦ G _Bi / G _Bo .   Applicable to heavy duty tires with a nominal tire width of 355 [mm] or more, a tire flatness of 55 [%] or less, a rim diameter of a specified rim of 17.5 [inch] or more, and a single mounting method. The pneumatic tire according to any one of claims 1 to 7.

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