JP2003104006A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a production process, to reduce a manufacturing cost, and to enhance durability, by eliminating stranded code. SOLUTION: A portion ranging over from a tread part 1 to a bead part 3 in a tire skeleton structure 4 astride a pair of left and right bead parts 3, 3 is constituted of plural kinds of polymer materials, without using the stranded code, at least two layers of composite layers 4X, 4Y layered in parallel with a plurality of polymer layers different in Young's moduli are formed in the tire skeleton member 4, the layers 4X, 4Y are arranged to make orientation directions thereof inclined to a circumferential direction of a tire and to be crossed each other between the layers, and a tread layer 6 is layered on an outer circumference of the tire skeleton member 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tire having a novel structure that does not include twisted cords. More specifically, the elimination of twisted cords simplifies the manufacturing process, reduces manufacturing costs, and improves durability. TECHNICAL FIELD The present invention relates to a pneumatic tire with improved durability.

[0002]

2. Description of the Related Art In a conventional pneumatic tire, twisted cords such as steel and organic fibers are covered with rubber, and the cord / rubber composite material is used as a tire reinforcing material for belts, carcass and the like. In addition, it is common to prepare a plurality of types of cord / rubber composite materials and use these as appropriate tire reinforcing materials to construct a pneumatic tire. Therefore, in the case of a tire structure using a twisted cord, not only the manufacturing process becomes complicated, but also the manufacturing cost including the material cost is significantly increased.

Further, it is more difficult to withstand, in a pneumatic tire using a twisted cord, separation is apt to occur between the cord and the rubber, especially at the belt end portion or the carcass turn-up portion, which lowers the durability of the tire. There was a problem.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a pneumatic tire capable of simplifying the manufacturing process, reducing the manufacturing cost, and improving the durability by eliminating the twisted cord. is there.

[0005]

A pneumatic tire of the present invention for achieving the above object comprises a tire frame member extending between a pair of left and right bead portions, and a bead from a tread portion without using a twist cord. At least two composite layers formed by arranging a plurality of polymer material layers having different Young's moduli in parallel in the tire frame member, and orienting these composite layers. The tires are arranged so that the directions thereof are inclined with respect to the tire circumferential direction and intersect each other between the layers, and a tread layer is laminated on the outer periphery of the tire frame member.

By thus constructing the tire frame member from a polymeric material and eliminating the twisted cord, the tire manufacturing process can be simplified as compared with the conventional one, and the manufacturing cost including the material cost can be greatly reduced. You can Further, in the conventional tire, separation easily occurs between the cord and the rubber at the belt end portion or the carcass turn-up portion, which has reduced the durability of the tire, but the tire of the present invention has a cord terminal. Since they do not exist, these inconveniences can be eliminated. Further, the absence of the twisted cord also contributes to the improvement of riding comfort.

In the present invention, since the twist cord is not used, when the tire frame member is made of a single polymer material from the tread portion to the bead portion, the factor that determines the rigidity distribution in the tire meridian section is substantially the tire frame. Only the thickness of the member, and if the rigidity distribution is set based on the thickness of the tire frame member, the weight of the tire will increase significantly.

Therefore, in the present invention, the tire frame member is composed of a plurality of types of polymer materials from the tread portion to the bead portion, and the rigidity distribution in the tire meridian section is appropriately determined based on the combination of the plurality of types of polymer materials. Change it. In particular, at least two composite layers are formed in a tire frame member by arranging a plurality of polymer material layers having different Young's moduli in parallel, and the orientation directions of these composite layers are inclined with respect to the tire circumferential direction. The layers are arranged so as to intersect each other. Thus, by forming a composite layer in which a plurality of polymer material layers having different Young's moduli are arranged in parallel and arranged so that their orientation directions are inclined with respect to the tire circumferential direction and intersect each other between layers, It is possible to form a smooth rigidity distribution which is similar to the rigidity distribution of a tire having a conventional structure using a twisted cord and which is not accompanied by a rapid change in rigidity due to the twisted cord. By forming such a rigidity distribution, it is possible to improve the ground contact shape in the standard air pressure filled state.

In the tire of the present invention, in order to reduce the separation at the belt edge, which is a drawback of the conventional radial tire, by reducing the modulus ratio of the twist cord and the coat rubber in the belt portion of the conventional radial tire, It makes up for the shortcomings.

That is, the modulus ratio in the conventional tire (modulus of twisted cord / modulus of coated rubber)
Is, for example, several thousand for twisted steel cord and rubber
The value becomes 10000, and this difference in modulus causes the separation at the belt edge. Therefore, in the present invention, this modulus ratio is set to
By setting it to about 00, preferably within 100, separation at the belt edge can be suppressed. Further, although the tire structure of the present invention utilizes the concept of the belt structure of the conventional radial tire, the constitution of the belt layer has the uniqueness of the present invention as shown below. By alternately arranging a material having a high modulus and a material having a low modulus, which are both polymeric materials, as the belt layer, the adhesiveness to each other is good. Furthermore, when conventional steel cords are lined up, separation from the untreated portion at the steel cord terminal at the belt edge (this portion is not plated because the steel cord is cut). There has always been. On the other hand, since the tire of the present invention is basically composed of a polymer material, such a problem of adhesiveness at the belt edge portion does not occur, and also from this point, the separation at the belt edge is suppressed. Has been done. Further, by setting the modulus ratio to about several hundreds, preferably within 100, it is possible to suppress the separation due to the interlayer shearing force at the belt edge.

The tire of the present invention is constructed by bias-laminating at least two composite layers as such a belt layer, and if an auxiliary layer having an appropriate modulus is further provided on either side of the composite layer. good. Specifically, it is preferable to use, as the material of the auxiliary layer, an intermediate material between the material having a high modulus and the material having a low modulus used in the composite layer. As a result, the belt layer can have more uniform rigidity. At this time, in selecting the modulus of this material, the so-called cord angle of the belt layer (in the present invention, the angle formed by the longitudinal direction of the high modulus materials arranged as the belt layer and the tire circumferential direction.
It is called the equivalent code angle. It is necessary to be selected in relation to That is, when the equivalent cord angle is low (10 degrees or less), the rigidity in the circumferential direction can be sufficiently retained by the composite layer, and in this case, the modulus of the material forming the auxiliary layer is lower than that of the composite layer. The modulus of the material is good enough. On the other hand, when the equivalent cord angle is high (10 degrees or more), the peripheral rigidity of the composite layer decreases, and in this case, the modulus of the material forming the auxiliary layer is higher than that of the material used in the composite layer. It is good to set it to a modulus of.

The Young's modulus of the polymer material forming the tire frame member is preferably 10 to 3000 MPa. By selecting such a polymer material, it becomes possible to sufficiently secure the rigidity required for the tire while eliminating the twisted cord.

According to the present invention, it is possible to construct a pneumatic tire in which the tire rigidity with respect to a vertical load in a non-internal pressure state is 30% or more of the tire rigidity with respect to a vertical load in a standard air pressure filled state. That is, this pneumatic tire supports the load applied in the tire radial direction by taking into consideration the tire internal pressure and the tire rigidity. Therefore, even if the tire is flat, the vehicle cannot run immediately and can travel a certain distance at a certain speed.

According to the present invention, there is provided a pneumatic tire for passenger cars, a pneumatic tire for light trucks, or a pneumatic tire for heavy loads having the above tire structure. here,
The standard air pressure filling state described above is a state in which the tire is filled with the air pressure specified during normal use. For example, the pneumatic tire for passenger cars may be 200 kPa, the pneumatic tire for small trucks may be 450 kPa, and the pneumatic tire for heavy loads may be 725 kPa. In the present invention, since the tire rigidity in the state of no internal pressure is large, it is possible to select an air pressure of 30 to 70% with respect to the air pressure specified by JATMA.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of the present invention will be described in detail below with reference to the accompanying drawings.

1 and 2 show a pneumatic tire according to an embodiment of the present invention, in which 1 is a tread portion, 2 is a sidewall portion, and 3 is a bead portion. The tire frame member 4 that straddles between the pair of left and right bead portions 3, 3 does not use a twisted cord, that is, a plurality of types from the tread portion 1 to the bead portion 3 while eliminating the twisted cord as a tensile member. It is composed of a polymer material. That is, in the tire frame member 4, in the tire meridian cross section, a plurality of composite layers 4X and 4Y in which a plurality of polymer material layers 4A and 4B having different Young's moduli are arranged in parallel and a plurality of polymer materials having a different Young's modulus are used. It comprises layers 4C, 4D, 4E, 4F, 4G, 4H.

More specifically, in the composite layers 4X and 4Y, a polymer material layer 4A having a high Young's modulus and a polymer material layer 4B having a Young's modulus lower than the polymer material layer 4A are alternately arranged, The Young's modulus in the direction in which these polymer material layers 4A and 4B are oriented is relatively high. As shown in FIG. 2, the orientation direction is inclined at an angle of 5 to 35 ° with respect to the tire circumferential direction. And are arranged so that the layers intersect each other. These composite layers 4X and 4Y correspond to conventional belt layers. Moreover, each of the polymer material layers 4C to 4H continuously extends in the tire circumferential direction. In particular,
The polymer material layer 4C is an auxiliary layer arranged along the composite layers 4X and 4Y. This auxiliary layer can be disposed above or below the composite layers 4X and 4Y and may be non-oriented or may have any orientation. In the bead portion 3, an annular bead core 5 is embedded in the tire frame member 4. The bead core 5 is preferably made of a material such as a metal wire having a higher tensile strength than the polymer material forming the tire frame member 4.

A tread layer 6 is laminated on the outer circumference of the tire frame member 4 in the tread portion 1. The tread layer 6 may be composed of a rubber composition for a cap tread that has been conventionally used. Shoulder part 7
Is a portion located between the tread portion 1 and the sidewall portion 2. An inner liner layer may be appropriately provided on the inner surface of the tire.

The pneumatic tire can be formed by winding a sheet material or a strip material of a polymer material around the outer surface of a rigid body such as a core having a shape similar to the tire shape.
Alternatively, the sheet material or the strip material made of a polymer material may be wound around the outer periphery of the cylindrical molding drum, and then the portion corresponding to the tread portion at the central portion in the axial direction may be bulged for molding. These sheet materials and strip materials do not require the rubber coating step for the twisted cord, which has been performed in the conventional tire manufacturing method, and can be easily and efficiently molded into an arbitrary shape by an extruder or the like. Moreover, it is no longer necessary to have many kinds of intermediate members having different numbers of cords and different cord angles as in the conventional case. for that reason,
The tire manufacturing process can be simplified as compared with the conventional one, and the manufacturing cost including material cost can be significantly reduced. Moreover, since the cord end does not exist in the pneumatic tire, it is possible to avoid a decrease in durability due to the separation of the cord and the rubber as in the conventional case.

Further, since the tire frame member 4 is composed of a plurality of kinds of polymer materials from the tread portion 1 to the bead portion 3, the rigidity distribution in the tire meridian cross section is calculated based on the combination of a plurality of kinds of polymer materials. It can be changed appropriately. More specifically, as shown in FIG. 3 (illustration), from the center position of the tread portion 1 to the shoulder portion 7 and further to the maximum width position of the sidewall portion 2 based on the combination of plural kinds of polymer materials. The rigidity is gradually decreased, and the rigidity is gradually increased from the maximum width position of the sidewall portion 2 to the bead portion 3 as shown in FIG. 4 (illustration diagram). For example, a polymer material composite layer 4X located in the tread portion 1,
By setting the Young's modulus of 4Y and the polymer material layer 4C relatively higher than that of the other polymer material layers 4D to 4H, the rigidity of the tread portion 1 can be increased without increasing the thickness. By forming such a rigidity distribution, it is possible to optimize the inflated shape when filling the internal pressure and to improve the ground contact shape when traveling. That is, it is similar to the rigidity distribution of a tire with a conventional structure using twisted cords, and forms a smooth rigidity distribution without a sudden change in rigidity due to twisted cords, improving the ground contact shape in the standard pneumatic filling state. can do.

In the pneumatic tire of the present invention, the tire rigidity against a vertical load in a non-internal pressure state is 30% or more, preferably 40 to 80%, more preferably 50% of the tire rigidity against a vertical load in a standard pneumatic filling state. ~ 70%. Therefore, even if the tire is flat, the vehicle cannot run immediately and can travel a certain distance at a certain speed.

Here, the rigidity due to air pressure (tension rigidity) and the rigidity due to the tire material (bending rigidity) will be described.
That is, in the conventional pneumatic tire, the air pressurized in the tire serves as an inflation pressure and supports the load applied to the tire as a pressure container. Therefore, in the conventional pneumatic tire, if the air pressure becomes zero due to the puncture, the function as the tire will hardly be fulfilled. That is,
As shown in Table 1, when the rigidity of the conventional tire as a whole is decomposed into tensile rigidity and bending rigidity, the ratio is 9
The ratio is 0% to 10%, and the tension rigidity due to the tire internal pressure is overwhelmingly large.

On the other hand, in the tire of the present invention, this ratio is 7
That is, the ratio of flexural rigidity is increased from 0% or less to 30% or more, so that even if the tire is flat, the minimum tire function is fulfilled. The minimum tire function referred to here is, for example, at least 400-
It means that it is possible to travel about 500 km. However,
Even in the tire of the present invention, if the flexural rigidity ratio is less than 30%, the amount of bending of the tire becomes large, and the tire cannot run.

[0024]

[Table 1] FIG. 5 shows the relationship between the vertical spring constant Kv and the air pressure in the conventional radial tire (comparative tire) and the tire of the present invention in FIG. From FIG. 5 as well, it can be seen that the tire of the present invention can run because the longitudinal spring constant Kv is sufficiently large even when the air pressure is zero.

In the tire of the present invention, the flexural rigidity of the tire is particularly important as compared with the conventional tire. Therefore, this bending rigidity is defined as equivalent bending rigidity as follows. That is, equivalent bending rigidity (kgf · mm) = modulus (kgf / mm ² ) × [section thickness (mm)] ³ .

Here, the cube of the thickness is used for the cross section 2
This is because the second moment is proportional to the cube of the thickness. Well
In addition, if materials with different rigidity overlap in the thickness direction,
The ratio is calculated from the distribution, and it is apparent from the sum of the products
It suffices to calculate the modulus of. For example, a thickness of 3 mm
Jura 100kgf / mm²Material and thickness 2mm, modulus 50kg
f / mm²If the materials in the above overlap, [3/5 x 100kgf
/ mm²] ＋ [2/5 × 50kgf / mm ²] ＝ 80kgf / mm²Becomes

The Young's modulus of the polymer material constituting the tire frame member 4 is preferably 10 to 3000 MPa, more preferably 15 to 2500 MPa, and further preferably 20 to.
2000 MPa. If the Young's modulus of the polymer material forming the tire frame member 4 is too low, the rigidity becomes insufficient when the tire frame member 4 is formed thin, and the tire frame member 4 is formed thick to obtain the required rigidity. If this is done, the weight will be increased. On the other hand, if the Young's modulus of the polymer material forming the tire frame member 4 is too high, the riding comfort deteriorates. In the combination of multiple types of polymer materials,
It is desirable that each polymer material exhibits the Young's modulus, but 80% by weight or more of the total amount of these polymer materials may exhibit the Young's modulus.

Examples of the polymeric material which can be used as a tire material and exhibit the above Young's modulus include the following. (1) Rubber and / or rubber composition The rubber and / or rubber composition is a rubber listed in the following examples, or a mixture of two or more rubbers selected arbitrarily, or a composition comprising the rubber and a compounding agent. is there. Examples of the rubber 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], and olefin. System rubber [eg ethylene propylene rubber (EPDM, EPM), maleic acid-modified ethylene propylene rubber (M-EPM)], butyl rubber (I
IR), isobutylene and aromatic vinyl or diene monomer copolymer, acrylic rubber (ACM), ionomer, halogen-containing rubber [eg Br-IIR, Cl-II
R, bromide of isobutylene paramethylstyrene copolymer (Br-IPMS), chloroprene rubber (CR), hydrin rubber (CHC, CHR), chlorosulfonated polyethylene (CSM), chlorinated polyethylene (CM), maleic acid modified chlorine Polyethylene (M-CM)], silicone rubber (for example, methyl vinyl silicone rubber, dimethyl silicone rubber, methylphenyl vinyl silicone rubber),
It is possible to use sulfur-containing rubber (for example, polysulfide rubber), fluororubber (for example, vinylidene fluoride-based rubber, fluorine-containing vinyl ether-based rubber, tetrafluoroethylene-propylene-based rubber, fluorine-containing silicon-based rubber, fluorine-containing phosphazene-based rubber), etc. it can.

As the rubber composition, a reinforcing agent such as carbon black or silica, which is generally compounded in the rubber composition, a filler, a cross-linking agent, a softening agent, an anti-aging agent, a processing agent, is added to these rubbers or rubber mixtures. Any composition may be used as long as it has a Young's modulus in a desired range by adding an auxiliary agent or the like, and more preferably in order to further strengthen the reinforcing property in order to obtain a material having a high Young's modulus, It is possible to use a composition in which a reinforcing agent such as a short fiber or a phenol resin is appropriately mixed. Examples of the short fiber reinforcing agent capable of imparting such a reinforcing property include aramid, nylon, vinylon, polyester,
Synthetic fibers such as polybenzobisoxazole, rayon,
Natural fibers such as cotton and inorganic fibers such as carbon and glass can be used, and it is preferable that they are subjected to an adhesion treatment with a treatment liquid such as RFL in order to further improve the adhesion with rubber. These long fibers are cut within a length range of 1 to 50 mm, and one kind or two or more kinds are appropriately mixed, respectively, and 2 to 50 parts by weight, preferably 3 to 35 parts by weight based on 100 parts by weight of rubber. It may be appropriately blended according to the desired Young's modulus. The method for producing the rubber composition may be a generally known method, for example, a method in which the above rubber component and the above reinforcing agent or the like are combined or sequentially kneaded at a predetermined temperature with a Banbury mixer or roll mixing and then calendered. By providing as a tire member. (2) Thermoplastic resin and / or thermoplastic resin composition The thermoplastic resin and / or the thermoplastic resin composition is a thermoplastic resin given in the following examples or a mixture of two or more kinds of thermoplastic resins selected arbitrarily. Or a composition comprising these resins and a compounding agent.

As the thermoplastic resin, for example, polyamimid resin [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 MX
D6, nylon 6T, nylon 6 / 6T copolymer, nylon 66 / PP copolymer, nylon 66 / PPS copolymer], polyester resin [eg polybutylene terephthalate (PBT), polyethylene terephthalate (P
ET), polyethylene isophthalate (PEI), polybutylene terephthalate / tetramethylene glycol copolymer, PET / PEI copolymer, polyarylate (P
AR), polybutylene naphthalate (PBN), liquid crystal polyester, aromatic polyester such as polyoxyalkylene diimide diacid / polybutylene terephthalate copolymer], polynitrile resin [eg polyacrylonitrile (PAN), polymethacrylonitrile, Acrylonitrile / styrene copolymer (AS), methacrylonitrile / styrene copolymer, methacrylonitrile / styrene / butadiene copolymer], poly (meth) acrylate resin [eg polymethylmethacrylate (PMMA), polymethacryl) Ethyl acid, ethylene ethyl acrylate copolymer (EEA), ethylene acrylic acid copolymer (EA
A), ethylene methyl acrylate resin (EMA)],
Polyvinyl resin [eg vinyl acetate (EVA), polyvinyl alcohol (PVA), vinyl alcohol / ethylene copolymer (EVOH), polyvinylidene chloride (PV
DC), 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 (PCTF
E), tetrafluoroethylene / ethylene copolymer (ET
FE)], imide resin [eg aromatic polyimide (P
I)], a thermoplastic elastomer (for example, a styrene-based elastomer, an olefin-based elastomer, a polyester-based elastomer, a urethane-based elastomer, a polyamide-based elastomer) or the like can be used.

Further, fillers (calcium carbonate, titanium oxide, alumina, clay, etc.), carbon black, white carbon, the above-mentioned short fibers, etc., which are generally added to the resin blend, are added to these resins or resin mixtures or resin compositions. A reinforcing agent, a softening agent, a plasticizer, a processing aid, a pigment, a dye, an antiaging agent, etc. may be appropriately blended in an amount that does not impair the intended Young's modulus.
The method for producing the thermoplastic resin and / or the thermoplastic resin composition is to melt-knead together the pelletized resin raw material and the above-mentioned filler as appropriate. The kneading machine used for kneading the thermoplastic resin is not particularly limited, and examples thereof include a screw extruder, a kneader, a Banbury mixer, a single-screw kneading extruder, and a two-screw kneading extruder. As the conditions for melt-kneading, the temperature may be equal to or higher than the temperature at which the thermoplastic resin melts. The shear rate during kneading is 2500 to 7500 s.
It is preferably ec ⁻¹ , and the total kneading time is preferably 30 seconds to 10 minutes. The obtained kneaded product is then extruded or calendered to be molded into a predetermined member shape or thinned to be used as a tire member. (3) Elastomer composition As the elastomer composition, a thermoplastic resin or a thermoplastic resin composition is used as a matrix, and a rubber and / or a rubber composition is dispersed as a domain (dispersed phase), more preferably at least the domain. A partially cross-linked composition can be appropriately used according to the desired Young's modulus.

The thermoplastic resin component used in the elastomer composition according to the present invention has a Young's modulus of 1 MPa.
Any thermoplastic resin having an ultra-high pressure, preferably 10 to 2000 MPa, and more preferably 10 to 1500 MPa can be used, and one selected from the resins given as examples in (2) above is used. You can Further, as the rubber component, one arbitrarily selected from the rubbers listed in the example in (1) above can be used. The composition ratio of the thermoplastic resin component (A) and the rubber component (B) is preferably 10/90 to 90/10, more preferably 20.
/ 80 to 85/15.

When the Young's modulus of the thermoplastic resin component is 1 MPa or less, the rigidity of the tire polymer composition is low,
It will no longer fulfill its function. Further, when the thermoplastic resin composition ratio is less than 10, the rigidity similarly decreases,
It is not preferable because it cannot be used for tires.

In addition to the above-mentioned components (A) and (B), other polymers and compounding agents such as a compatibilizer can be added to this elastomer composition as a third component. The purpose of mixing the other polymer is to improve the compatibility of the thermoplastic resin component and the elastomer component, to improve the film moldability of the material, to improve the heat resistance, to reduce the cost, etc., Materials used for this include, for example, polyethylene, polypropylene,
Examples thereof include polystyrene, ABS, SBS, and polycarbonate.

Further, the elastomer composition according to the present invention further comprises fillers (calcium carbonate, titanium oxide, alumina, clay, etc.), carbon black, white carbon, etc., which are generally added to polymer blends. A softening agent, a plasticizer, a processing aid, a pigment, a dye, an antiaging agent and the like may be optionally added as long as the Young's modulus requirement is not impaired. Also, the elastomer component may be dynamically vulcanized during mixing with the thermoplastic resin. Vulcanizing agents, vulcanization aids, vulcanization conditions (temperature, time), etc. for dynamically vulcanizing the elastomer component may be appropriately determined according to the composition of the elastomer component to be added, and are not particularly limited. Not a thing.

As the vulcanizing agent, a general rubber vulcanizing agent (crosslinking agent) can be used. Specifically, as the ionic vulcanizing agent, powdered sulfur, precipitated sulfur, highly dispersible sulfur, surface-treated sulfur, insoluble sulfur, dimorpholine disulfide, alkylphenamide (CBS), N
-Oxydiethylene benzothiazyl-2-sulfenamide, Nt-butyl-2-benzothiazole sulfenamide, 2- (thymolpolynyldithio) benzothiazole, etc. can be exemplified, and for example, 0.5 to 4 phr [Parts by weight per 100 parts by weight of the rubber component (polymer)] can be used. Examples of organic peroxide-based vulcanizing agents include benzoyl peroxide, t-butyl hydroperoxide, 2,4-bichlorobenzoyl peroxide, 2,5-dimethyl-2,5-di (t-butyl). Peroxy) hexane, 2,5-dimethylhexane-2,5
-Di (peroxylbenzoate) and the like are exemplified, and for example, about 1 to 20 phr can be used. Examples of the phenol resin-based vulcanizing agent include bromides of alkylphenol resins and mixed crosslinking systems containing a halogen donor such as tin chloride and chloroprene and an alkylphenol resin. For example, 1 to 20 phr is used. You can Others include zinc white (about 5 phr), magnesium oxide (about 4 phr), litharge (10-20).
Degree), p-quinonedioxime, p-dibenzoylquinonedioxime, tetrachloro-p-benzoquinone, poly-p-dinitrosobenzene (about 0.2 to 10 phr),
Examples include methylenedianiline (about 0.2 to 10 phr).

If desired, a vulcanization accelerator may be added. Examples of the vulcanization accelerator include aldehyde / ammonia type, guanidine type, thiazole type, sulfenamide type, thiuram type and dithioate salts. A general vulcanization accelerator such as a system or thiourea system can be used, for example, in an amount of about 0.5 to 2 phr. Specifically, aldehyde / ammonia-based vulcanization accelerators include hexamethylenetetramine, guanidine-based vulcanization accelerators such as diphenylguadinine, and thiazole-based vulcanization accelerators such as dibenzothiazyl sulfide (DM). ), 2-mercaptobenzothiazole and its Zn salt, cyclohexylamine salt, etc., and sulfenamide vulcanization accelerators include cyclohexylbenzothiazylsulfenamide (CBS) and N-oxydiethylenebenzothiazyl-2-sulfate. Fenamide, Nt-butyl-2-benzothiazole sulfenamide, 2- (thymolpolynyldithio) benzothiazole, and the like, as thiuram-based vulcanization accelerators, tetramethylthiuram disulfide (TMTD), tetraethylthiuram Disulfide, Tetramethy Monosulfide (TMTM), di preventor thiuram tetrasulfide and the like, as the dithio acid salt-based vulcanization accelerator,
Zn-dimethyldithiocarbamate, Zn-diethyldithiocarbamate, Zn-di-n-butyldithiocarbamate, Zn-ethylphenyldithiocarbamate, T
e-diethyldithiocarbamate, Cu-dimethyldithiocarbamate, Fe-dimethyldithiocarbamate,
Examples of the thiourea-based vulcanization accelerator such as pipecoline pipecolyl dithiocarbamate include ethylene thiourea and diethyl thiourea. As the vulcanization accelerating aid, general rubber auxiliaries can be used in combination, for example, zinc white (about 5 phr), stearic acid, oleic acid and their Zn salts (about 2 to 4 phr). Etc. can be used.

In the method for producing the elastomer composition, the thermoplastic resin and the rubber component (unvulcanized product) are melt-kneaded in advance with a biaxial kneading extruder or the like, and the rubber component is added to the thermoplastic resin forming the continuous phase. By dispersing. When vulcanizing the rubber component, a vulcanizing agent may be added under kneading to dynamically vulcanize the rubber component. Further, various compounding agents (excluding the vulcanizing agent) to the thermoplastic resin or the rubber component may be added during the above kneading, but it is preferable to mix them in advance before the kneading. The kneading machine used for kneading the thermoplastic resin and the rubber component is not particularly limited, and examples thereof include a screw extruder, a kneader, a Banbury mixer, and a twin-screw kneading extruder. Above all, it is preferable to use a twin-screw kneading extruder for kneading the resin component and the rubber component and dynamically vulcanizing the rubber component.
Further, two or more kinds of kneaders may be used and kneading may be sequentially performed. As a condition for melt-kneading, the temperature may be equal to or higher than the temperature at which the thermoplastic resin melts. The shear rate during kneading is preferably 2500 to 7500 sec ^-1 . The total kneading time is preferably 30 seconds to 10 minutes, and when the vulcanizing agent is added, the vulcanization time after addition is preferably 15 seconds to 5 minutes. The thermoplastic elastomer composition produced by the above method is then extruded or calendered into a predetermined member shape or formed into a thin film.
The member or thin film having a predetermined shape thus obtained is
It has a structure in which the rubber component (B) is dispersed as a discontinuous phase in the matrix of the thermoplastic resin (A). By adopting such a structure, it is possible to impart sufficient Young's modulus and flexibility to a member or a thin film, and at the same time as forming a member and forming a thin film, regardless of the amount of the rubber component, a molding process equivalent to that of a thermoplastic resin. You can get sex.

[0039]

EXAMPLES Examples of the present invention will be described below. However, the polymer material used in the present invention is not limited to this example.

Tire size is 205 / 65R15,
Tires A, B and C of the present invention having the following tire structures were manufactured. As a comparative tire, a carcass layer having the same tire size and having a plurality of organic fiber cords aligned and rubber-coated, and a two-layer belt layer having a plurality of steel cords aligned and rubber-coated. A commercially available tire having a conventional structure was used.

Tire A of the present invention: As shown in FIG. 1, a tire frame member extending between a pair of left and right bead portions is formed from a tread portion to a bead portion without using a twist cord, and a plurality of kinds of polymer materials ( Elastomer composition) to form a plurality of composite layers in which a plurality of polymer material layers having different Young's moduli are arranged in parallel in a tire frame member, and the orientation directions of these composite layers are relative to the tire circumferential direction. And are arranged so that they intersect each other between layers,
A tread layer made of a rubber composition was laminated on the outer periphery of the tire frame member.

The elastomer composition was prepared based on the compounding ratio shown in Table 2. First, samples were prepared using the compounding ratios shown in Table 2. After the polyester resin pellets are charged through the first charging port of the twin-screw kneading extruder and melt-kneaded,
Pellets of the polymer component are charged through the second charging port, the rubber component is finely dispersed in the polyester resin, and then the cross-linking agent component is charged through the third charging port at the indicated ratio to move the rubber component. Were cross-linked and the rubber phase was fixed. The thermoplastic elastomer component thus obtained was extruded in a strand form from the tip of a twin-screw kneading extruder, cooled with water, and then pelletized with a pelletizer for resin. The Young's modulus of the elastomer composition used for each material layer is as shown in Table 2.

[0043]

[Table 2] In Table 2, ¹⁾ Product name: Ultradurer B4550 (BASF) ²⁾ Product name: EXXPRO90-10 (ExxonMobil Chemical) ³⁾ Product name: Zinc Hua No. ³ (Shodochemical) ⁴⁾ Product name: Bead stearic acid (Nippon Yushi) ⁵⁾ Trade name: Zinc stearate (Chemical Chemicals Co., Ltd.) When material layers having a high Young's modulus and material layers having a low Young's modulus are alternately arranged, they are co-extruded at the tips of two 40 mm caliber single screw extruders Type T type die is installed, pelletized high Young's modulus material and low Young's modulus material are extruded from different extruders, and the die is integrated while controlling the die structure so that the die is even on the left and right, and the width is 4 mm. , Thickness 2.0 mm
Extruded into strips. Further, these were arranged side by side so as to have an appropriate width and cut with a bias cutter at an appropriate angle to produce a so-called composite layer corresponding to a belt layer.
At that time, an adhesive tape was attached to the upper surface of the aligned members so that the aligned members would not come apart. The surfaces of the composite layer, which had been bias-cut as described above, on which the adhesive tape was not adhered were overlapped so as to form a bias laminate, and then the adhesive tape was peeled off. The composite layer thus formed was subjected to tire molding so that the orientation direction was inclined with respect to the tire circumferential direction. However, the equivalent cord angle of the composite layer corresponding to the belt layer was -20 ° in the upper stage and 20 ° in the lower stage. For the other material layers, a T-type sheeting die was installed at the tip of one single-screw extruder, and the width was 5 mm.
It was extruded into a strip having a thickness of 1.0 mm. These strips were wound up and used for tire molding.

The above-mentioned tape-shaped member was wound around a composite layer of bias laminated layers at an appropriate position on a drum to form a tire frame member with a predetermined tire sectional shape. And, in order to secure the adhesiveness between the tread rubber and the thermoplastic elastomer composition in the region where the tread member is wound, a chlorinated rubber adhesive, a phenolic resin adhesive and an isocyanate adhesive that can be usually used. Of these, an isocyanate adhesive, Chemlock 402, was sufficiently applied and then dried. In addition, the bead portion was sufficiently coated with Chemloc 205, which is a chlorinated rubber adhesive, on a member in which an ordinary steel bead wire was wound in advance, and then dried, and the adhesive-treated product was used and subjected to a molding treatment. .

After molding the above-mentioned molded product on a drum, it is blow-molded into a predetermined tire vulcanized shape, and after maintaining the shape, the tread rubber composition extruded to a predetermined size is attached to the tread portion and added. The molded body was subjected to the vulcanization process.
This molded body is put into a normal tire vulcanizing mold, and after degassing gas components such as air that have been caught during molding, it is heated and pressed at 220 ° C. for 5 minutes to obtain a tire frame member made of a thermoplastic elastomer. After completing the shape of the rubber tread into the predetermined shape, the shape of the rubber tread and the vulcanization, and the adhesion of the tire frame member to the beads and the tread, the mold temperature is lowered to 100 ° C. under pressure, and the tire is removed from the mold. Was taken out to obtain a pneumatic tire having a desired shape shown in FIG.

The vulcanization step is not limited to this example, and various known molding / vulcanization methods such as so-called injection molding / vulcanization, transfer molding / vulcanization and the like can be used. Of course.

Tire B of the present invention: An elastomer composition used for a tire frame member was prepared based on the compounding ratio of Table 3, and the equivalent cord angle of the composite layer corresponding to the belt layer was -6 ° in the upper stage and the lower stage. A pneumatic tire having a desired shape shown in FIG. 1 was obtained by the same procedure as the tire A of the present invention except that the tire was set to 6 °. The materials in Table 3 are the same as those in Table 2.

[0048]

[Table 3] Inventive tire C: The desired cord shown in FIG. 1 was obtained by the same procedure as in inventive tire A except that the equivalent cord angle of the composite layer corresponding to the belt layer was -16 ° in the upper stage and 16 ° in the lower stage. A pneumatic tire having a shape was obtained. Table 4 collectively shows the differences between the tires A to C of the present invention.

[0049]

[Table 4] Regarding these test tires, the amount of deflection, the actual ground contact area, the vertical spring constant, and the rim width of 6.5 JJ and the test load of 4 kN were used.
The lateral spring constant and the peripheral spring constant were measured, and the results are shown in Table 5. These measurement results are shown by an index with the comparative tire being 100. The larger the index value, the larger the measured value.

[0050]

[Table 5] As can be seen from Table 5, the tire of the present invention exhibited a good spring constant when the air pressure was set to about half that of the comparative tire, and it was possible to secure the necessary actual ground contact area. The tire of the present invention, in terms of tire internal pressure and tire rigidity, in exhibiting the function as a tire, may be the same as the internal pressure of the conventional tire, but in order to more effectively exhibit the effect of the present invention, it is preferably a conventional tire Internal pressure of 30 to 7
It is good to set it to 0%, more preferably to about 50%.

[0051]

As described above, according to the present invention, the tire frame member that extends between the pair of left and right bead portions is provided with plural kinds of polymer materials from the tread portion to the bead portion without using a twist cord. And forming at least two composite layers in which a plurality of polymer material layers having different Young's moduli are arranged in parallel in the tire frame member, and the orientation direction of these composite layers is inclined with respect to the tire circumferential direction. In addition, the tread layer is laminated on the outer periphery of the tire frame member while being arranged so as to intersect each other between layers, so that the tire manufacturing process can be simplified, the manufacturing cost can be reduced, and the durability can be improved. . The rigidity distribution in the tire meridian section can be arbitrarily adjusted based on the combination of plural kinds of polymer materials.

[Brief description of drawings]

FIG. 1 is a meridian half cross-sectional view showing a pneumatic tire according to an embodiment of the present invention.

FIG. 2 is a cutaway perspective view showing a main part of a pneumatic tire according to an embodiment of the present invention.

FIG. 3 is a graph showing the rigidity distribution from the center position of the tread portion to the shoulder portion in the pneumatic tire of the present invention.

FIG. 4 is a graph showing a rigidity distribution from a maximum width position of a sidewall portion to a bead portion in the pneumatic tire of the present invention.

FIG. 5 is a graph showing the relationship between the vertical spring constant Kv and the air pressure in the pneumatic tire of the present invention (FIG. 1).

[Explanation of symbols]

1 tread section 2 Side wall part 3 bead part 4 Tire frame members 4A-4C composite layer 4D-4H polymer material layer 5 bead core 6 tread layers 7 Shoulder

Continued front page    (72) Inventor Kazuyuki Kabe             2-1, Oiwake, Hiratsuka-shi, Kanagawa Yokohama Rubber Co., Ltd.             Ceremony Company Hiratsuka Factory

Claims (7)

[Claims] 1. A tire frame member that straddles between a pair of left and right bead portions is made of a plurality of types of polymer materials from a tread portion to a bead portion without using a twist cord.
In the tire frame member, at least two composite layers are formed by arranging a plurality of polymer material layers having different Young's moduli in parallel, and these composite layers have an orientation direction inclined with respect to the tire circumferential direction and an interlayer. And a tread layer laminated on the outer circumference of the tire frame member. 2. The pneumatic tire according to claim 1, wherein an auxiliary layer made of a material having non-orientation or any orientation is arranged on the upper and / or lower part of the composite layer. 3. The pneumatic tire according to claim 1, wherein the polymeric material forming the tire frame member has a Young's modulus of 10 to 3000 MPa. 4. The pneumatic tire according to any one of claims 1 to 3, wherein a tire rigidity against a vertical load in a non-internal pressure state is 30% or more of a tire rigidity against a vertical load in a standard pneumatic filling state. 5. A pneumatic tire for passenger cars having the tire structure according to any one of claims 1 to 4. 6. A pneumatic tire for a light truck having the tire structure according to claim 1. 7. A heavy duty pneumatic tire having the tire structure according to claim 1.