JPH06234303A - Radial tire - Google Patents

Abstract

PURPOSE:To provide a radial tire lightweight with small energy loss so as to realize excellent maneuvering stability by forming the cap tread, base tread, side wall and bead apex of the tire respectively of rubber compositions containing material with specified properties. CONSTITUTION:The cap tread of a tire 4 is formed of a rubber composition of -30 deg.C or higher in tan delta peak temperature after curing. The base tread 1 and a side wall are formed of a rubber composition containing 30wt. parts or less of carbon black of 30-90mg/g in the iodine adsorption number and 10wt. parts or more of short fiber 2 to 10wt. parts of a rubber component, with the direction of the short fiber 2 oriented in the axial direction of the tire 4 in the base tread 1 and circumferentially in the side wall. The bead apex is formed of a rubber composition containing 65wt. parts or more of cabon black of 60-100mg/g in the iodine adsorption number to 100wt. parts of a rubber composition, with short fiber 2 oriented in the axial direction of the tire 4 or in the direction intersecting the axial direction. The tire 4 is thereby lightweight and small in rolling resistance so as to improve fuel consumption and attain excellent maneuvering stability and riding comfort.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radial tire, and more particularly to a radial tire capable of reducing fuel consumption of a vehicle.

[0002]

2. Description of the Related Art In recent years, global environmental problems such as ozone depletion, acid rain and the greenhouse effect of the earth have been taken up. Since these problems are largely due to the components in the exhaust gas generated by the combustion of car fuel such as gasoline, reducing the combustion amount of car fuel can be an effective solution to these problems.

Therefore, for example, in North America, basic laws relating to fuel economy, such as the Gas Guzzler Tax and company average fuel economy (CAFE), are under deliberation. As technological development corresponding to CAFE, efficiency improvement of the engine etc., reduction of energy loss in each part of the vehicle,
Research has been conducted into reducing the weight of cars. That is, reduction of energy loss in the tire and weight reduction of the tire are one solution to the above problems.

In order to reduce the energy loss of the tire,
Decrease in tan δ peak temperature of cap tread (measure
-1) is performed, but when the tan δ peak temperature becomes low, the wet grip tends to decrease. Further, for the same purpose, the carbon content of the cap tread is reduced (Countermeasure-2), but when the carbon content is reduced, the wet / dry grip tends to decrease, and the abrasion resistance tends to decrease. Also, by adopting a cap / base structure for the tread and reducing the carbon content of the base tread rubber (countermeasure), it is possible to reduce tire energy loss, but if the carbon content of the base tread rubber is reduced, the rigidity decreases. Therefore, the steering stability tends to deteriorate. Furthermore, for the same purpose, the energy loss of the sidewall rubber is reduced by reducing the carbon content of the sidewall rubber (countermeasure). However, if the carbon content of the sidewall rubber is reduced, the rigidity decreases. Steering stability tends to deteriorate.

Further, in order to reduce the weight of the tire, the groove depth of the cap tread rubber is made shallow (countermeasure), but if the groove depth becomes shallow, the life of the tire tends to be shortened. Further, for this purpose, the thickness of the sidewall is reduced (countermeasure), but when the thickness of the sidewall is reduced, steering stability tends to deteriorate due to insufficient rigidity of the tire. Further, weight reduction can be achieved by reducing the volume of the bead apex (countermeasure), but when the bead apex becomes smaller, the steering stability tends to deteriorate.

[0006]

[Problems to be Solved by the Invention] Further, the above-mentioned measures-1,
-2-By combining the measures, you can obtain lightweight tires with low energy loss and reduce fuel consumption of the car.
Such tires have poor steering stability such as grip and steering response.

In order to improve steering stability, a tire including short fibers in each component such as a base tread, a side wall, and a bead filler has been devised (Japanese Patent Laid-Open Nos. 59-204637 and 59-204637). -204
No. 638, No. 61-25605, and No. 63-2.
No. 63104) cannot reduce the energy loss and reduce the weight.

The present invention has been made in view of the above problems, and an object thereof is to reduce energy loss, light weight, and
It is intended to provide a radial tire that can provide excellent steering stability of a car.

[0009]

The above object of the present invention is to provide a cap tread made of a rubber composition having a tan δ peak temperature after vulcanization of -30 ° C or higher, and 100 parts (parts by weight; hereinafter the same) of a rubber component. On the other hand, iodine adsorption amount 30-90mg
/ G carbon black 30 parts or less, a rubber composition containing a rubber composition containing 10 parts or more of short fibers, the short fibers being oriented substantially in the axial direction of the tire (hereinafter referred to as the axial direction), a rubber component 100. Iodine adsorption amount to 30 parts
˜90 mg / g of carbon black 30 parts or less, a rubber composition containing 10 parts or more of short fibers, the short fibers being oriented in the tire circumferential direction, and iodine adsorption to 100 parts of the rubber component. Amount 60-100mg
Of a rubber composition containing 65 parts or more of carbon black / g of carbon black and 20 parts or more of short fibers, and the bead apex in which the short fibers are oriented in the axial direction of the tire or in a direction intersecting the axial direction. Achieved by tires.

[0010]

FUNCTION AND EXAMPLE The radial tire of the present invention is a tire characterized by a cap tread, a base tread, a sidewall and a bead apex.

Cap tread The cap tread of the radial tire of the present invention has a tan δ peak temperature after vulcanization of -30 ° C or higher, preferably -3.
It consists of a rubber composition of 0 to -10 ° C. The balance between rolling resistance and wet grip changes depending on the tan δ peak temperature, and when the tan δ peak temperature is lower than -30 ° C, rolling resistance tends to decrease but wet grip tends to deteriorate.

The rubber component of this rubber composition is not particularly limited, but solution polymerization SBR is preferable because of its property of lowering rolling resistance and improving wet grip. This rubber composition is usually 40 to 80 parts of carbon, 1 to 40 parts of oil, 1 to 3 parts of wax, and 100 parts of the rubber component.
1 to 3 parts anti-aging agent, 1 to 3 parts sulfur, 1 to 2 parts accelerator, standard grip orientation, LRR
(Low rolling resistance) Directional composition is applied.

The thickness of the cap tread is usually 5 to 9
It is about mm.

Base tread The rubber composition forming the base tread of the present invention has an iodine adsorption amount of 30 to 90 mg / g, preferably 30 to 70 mg.
30 parts or less, preferably 5 to 30 parts, of 100 parts / g of carbon black. When the iodine adsorption amount is less than 30 mg / g, steering stability deteriorates,
If it exceeds 90 mg / g, the rolling resistance tends to deteriorate (become larger). If the amount of carbon black exceeds 30 parts, the rolling resistance tends to deteriorate.

The rubber composition forming the base tread of the present invention further contains 10 parts or more, preferably 10 to 30 parts, of short fibers per 100 parts of the rubber component. As shown in FIG. Are oriented in the axial direction of the tire 4 in the base tread 1. Here, the axial direction means a direction substantially orthogonal to the tire circumferential direction. When the amount of the short fibers is less than 10 parts, the elastic modulus in the axial direction decreases, the lateral rigidity decreases, the steering stability deteriorates, and the rolling resistance tends to increase. When the orientation direction of the short fibers is not the axial direction of the tire, for example, the circumferential direction, steering stability and rolling resistance cannot be improved. As this short fiber, for example, UBEPOL
-Short fibers grafted on natural rubber such as HE 0100 (manufactured by Ube Industries, Ltd.), that is, an average diameter of about 0.
It is possible to use 6 nylon having a thickness of 3 μm and an average length of about 300 μm.

The rubber composition forming the base tread of the present invention usually contains a total of 30 parts or less of carbon per 100 parts of the rubber component (the iodine adsorption amount may include those other than 30 to 90 mg / g), It comprises 0 to 10 parts oil, 0 to 2 parts wax, 0 to 3 parts antioxidant, 1 to 3 parts sulfur, 1 to 2 parts accelerator.

The thickness of the base tread is usually 1 to 5 m.
It is about m. The total thickness of the base tread and the cap tread is usually about 10 mm.

The base tread used in the present invention can be produced, for example, by the following method.

Method for producing base tread 1 The above-mentioned rubber, carbon black, short fibers and other additives are kneaded using a Banbury mixer to prepare a rubber composition for the base tread. This rubber composition 5
Is rolled using a calender roll 6 as shown in FIG. 3 to obtain a sheet having a thickness of 1 to 6 mm. In the case of the axial orientation, as shown in FIG. 3, sheet pieces whose longitudinal direction is the direction perpendicular to the rolling direction are cut out and joined so as to have a predetermined length to form a base tread.

Base tread preparation method 2 The rubber composition for base tread prepared by kneading as described above is extruded into a tube shape by an extruder. As a result, the short fibers in the rubber composition are oriented parallel to the longitudinal direction of the tube. As shown in FIG. 4, this tubular extrudate has a predetermined cutting angle θ (angle with respect to a direction perpendicular to the tube axis).
A sheet piece is cut out in a spiral shape to form a base tread. If the tube diameter is large enough and the cutting angle θ is small, the base tread will be axially oriented.

Sidewall The rubber composition forming the sidewall of the present invention has an iodine adsorption amount of 30 to 90 mg / g, preferably 30 to 70 mg.
/ G, carbon black in an amount of 30 parts or less, preferably 10 to 30 parts per 100 parts of the rubber component. When the iodine adsorption amount is less than 30 mg / g, the steering stability tends to deteriorate, and when it exceeds 90 mg / g, the rolling resistance tends to deteriorate. If the amount of carbon black exceeds 30 parts, the rolling resistance tends to increase.

The rubber composition forming the side wall of the present invention further contains 10 parts or more, preferably 10 to 30 parts, of short fibers to 100 parts of the rubber component. As shown in FIG. Are oriented in the sidewall 3 in the circumferential direction of the tire 4. When the amount of the short fibers is less than 10 parts, the steering stability tends to deteriorate. If the orientation direction of the short fibers is not the circumferential direction of the tire, for example, the axial direction, the steering stability cannot be improved. As the short fibers, for example, the above-mentioned UBEPOL-HE 0100 (manufactured by Ube Industries, Ltd.) or the like can be used.

The rubber composition forming the side wall of the present invention is usually 30 parts or less in total of carbon per 100 parts of the rubber component (Iodine adsorption amount may be other than 30 to 90 mg / g), It comprises 0-10 parts oil, 1-3 parts wax, 2-5 parts antioxidant, 1-3 parts sulfur, 1-2 parts accelerator.

The thickness of the side wall is usually 1 to 5 m.
It is about m.

In the base tread manufacturing method 1,
As shown in FIG. 3, a sheet having a predetermined length with the rolling direction as the longitudinal direction may be cut out to form a sidewall, or may be extruded by an extruder by a conventional method.
However, it is preferable that the sidewall is formed by the ORBI method. The ORBI method is a method in which a string-shaped extrudate is wound around the side wall part by an extruder and molded, and since there is no joint, there is no opening at the time of processing the joint part and the circumference is uniform. It is preferable in that it is molded into. For example, in a normal molding method in which a sidewall-integrated extrudate is molded and inflated, the green strength in the circumferential direction is high, and the joint is separated during inflation.

Bead apex The rubber composition forming the bead apex of the present invention has an iodine adsorption amount of 60 to 100 mg / g, preferably 60 to 9
65 mg or more, preferably 65 to 100 parts, of 0 mg / g of carbon black is contained per 100 parts of the rubber component. When the iodine adsorption amount is less than 60 mg / g, the steering stability is deteriorated, and when it exceeds 100 mg / g, extrusion tends to be difficult. When the amount of carbon black is less than 65 parts, steering stability tends to deteriorate.

The rubber composition forming the bead apex of the present invention further contains 20 parts or more, preferably 20 to 50 parts, of short fibers with respect to 100 parts of the rubber component, and the short fibers are contained in the tire of the base tread. Is oriented in the axial direction or in a direction intersecting the axial direction. Here, the direction intersecting the axial direction means that the angle intersecting the axial direction is ± 30 to 6
The direction is 0 °, preferably ± 45 °. When the amount of short fibers is less than 20 parts, the steering stability tends to deteriorate. When the orientation direction of the short fibers is not the axial direction of the tire or the direction intersecting the axial direction, for example, the circumferential direction, the steering stability is not improved. As the short fibers, for example, the above-mentioned UBEPOL-HE 0100 (manufactured by Ube Industries, Ltd.) or the like can be used.

The rubber composition forming the bead apex of the present invention is usually 50 to 80 relative to 100 parts of the rubber component.
Part of carbon (total amount including iodine adsorption amount other than 30-100 mg / g), 0-5 parts oil, 0-2
Parts wax, 0-3 parts anti-aging agent, 2-6 parts sulfur, 2-5 parts accelerator.

The height of the bead apex is usually 10
It is about 70 mm.

The radial tire of the present invention is manufactured by a general manufacturing method, in which the compounded and mixed unvulcanized rubber is subjected to steps such as calendering, topping, extrusion, and after being molded and then vulcanized.

The radial tire of the present invention is particularly suitable for passenger vehicles and commercial vehicles.

The present invention will be described below with reference to production examples and examples, but the present invention is not limited thereto. The tire testing methods and results notation methods in the production examples and examples are listed below.

Rolling resistance: 2.5 kg of tire internal pressure
The rolling resistance was measured using a uniaxial drum tester at a load of 350 kgf and a speed of 80 km / h. The results are expressed as relative values with the reference tire as 100, and the smaller the index, the better.

Steering response / grip (driving stability): Tires to be tested were mounted on four wheels of a 1600cc class domestic FF vehicle, and steering stability was evaluated at the Sumitomo Rubber Okayama test course. The steering wheel responsiveness is the responsiveness of the vehicle to the steering wheel operation during straight running, and the grip is the limit speed and behavior when the vehicle starts to slide due to centrifugal force during coupling. It was expressed by the law. The higher the score, the better, and the one with + indicates the better at that point.

Wet brake: Four tires of the same passenger car used for steering stability were fitted with tires to be tested,
In the test course, water was sprayed on the asphalt road surface, and μ depending on the braking distance from 40 km / h to the stop

[0036]

[Equation 1]

Was calculated. The result is expressed as a relative value with the reference tire as 100, and the larger the index, the better.

Ride comfort: Tires to be tested were mounted on the four wheels of the same passenger car used for steering stability, and shocks on various road surfaces (stone damage road, step road, repair road, etc.) on the test course. The feeling, damping, hardness, etc. were evaluated. The display method of the result is the same as that of the steering stability.

Table 1 shows the compositions of members other than those manufactured as the characteristic constituent members in the manufacturing examples.

[0040]

[Table 1]

Production Example 1 (Cap tread) 60 parts of solution-polymerized SBR (15% by weight of bound styrene, 30 mol% of vinyl content), 40 parts of NR, 60 parts of N351 (carbon black), 25 parts of aromatic oil, wax 1. 5 parts, anti-aging agent 6PPD 1.5 parts, stearic acid 2 parts, zinc white 3 parts, sulfur 1.75 parts, accelerator C
A cap tread rubber was prepared by kneading with 1.5 parts of Z in a Banbury. A base tread rubber was prepared using the composition of the base tread shown in Table 1. A tread having a cap / base structure was prepared by extruding these rubbers with an extruder so that the cap tread was the upper layer and the base tread was the lower layer.
Molding and vulcanization are performed using this tread and the sidewalls and bead apex whose compositions are shown in Table 1, so that DUNL except for the cap tread, base tread, sidewall and bead apex is formed.
Radial tire A (185 / 65R14) corresponding to OP SP7 (manufactured by Sumitomo Rubber Industries, Ltd.) was manufactured. This radial tire A was tested for rolling resistance and wet brake. Further, the rubber was taken out from the cap tread and the tan δ peak temperature was measured.

The composition and t of this cap tread rubber
Table 2 shows the an δ peak temperature and the test results of the radial tire A.

As shown in Table 2, radial tires B, C and D were produced by the same method as described above with the same composition of cap tread rubber as described above except that the compositions of rubber and carbon black were changed. Table 2 shows the test results of the tan δ peak temperature of each cap tread, the rolling resistance of the tire, and the wet brake.

The radial tire D is a tire having general wet grip performance, and the rolling resistance and wet brake test results of other tires are shown with the radial tire D as a reference.

[0045]

[Table 2]

From the results shown in Table 2, it can be seen that when the tan δ peak temperature after vulcanization of the cap tread is lower than -30 ° C, rolling resistance is reduced but wet grip is deteriorated.

Production Example 2 (base tread) NR 70 parts, BR 30 parts, short fiber (UBEPOL-HE)
0100 short fiber) 15 parts, FEF 10 parts, aromatic oil 5 parts, phenolic resin 3 parts, wax 1.5 parts, antioxidant 6PPD 2 parts, stearic acid 2
Base, 4 parts of zinc white, 2 parts of sulfur and 1.3 parts of accelerator CZ to prepare a base tread rubber by kneading in a Banbury. Further, a cap tread rubber was prepared using the composition of the cap tread shown in Table 1.
When short fibers are not blended and short fibers are oriented in the tire circumferential direction, these rubbers are extruded with an extruder so that the cap tread is the upper layer and the base tread is the lower layer. A structural tread was prepared. When the short fibers were oriented in the axial direction, the cap tread was extruded, and the base tread was cut out from the calender sheet separately from the cap tread and attached at the time of molding. By using this tread and the sidewalls and bead apex whose composition is shown in Table 1, molding and vulcanization are performed to obtain a radial tire corresponding to DUNLOP SP7 except for the cap tread, base tread, sidewall and bead apex ( A)
(185 / 65R14) was produced. The radial tire (A) was tested for rolling resistance and steering stability (handle response).

Table 3 shows the composition of the base tread rubber, the orientation direction of the short fibers in the base tread rubber, and the test results of the radial tire (A).

As shown in Table 3, the composition of the rubber, carbon black and short fibers and the orientation direction of the short fibers were changed, and the same composition of the base tread rubber as that described above was used. (I) was produced. Here, the iodine adsorption amount of carbon black is FE
F43 mg / g, HAF82 mg / g, ISAF121
mg / g, ISAF does not correspond to the present invention. Table 3 shows the results of testing the rolling resistance and steering stability (handle response) of each radial tire.

The radial tire (B) is a tire having general rolling resistance and steering stability, and the test results of rolling resistance and steering stability (handle response) of other tires based on the radial tire (B). Represents

[0051]

[Table 3]

From the results of Table 3, carbon black is FE
HAF improves steering stability more than F, and when the amount of short fibers is less than 10 parts, steering stability is poor,
If the compounding amount of carbon black is more than 30 parts, the rolling resistance is inferior (increased). If the iodine adsorption amount of carbon black is more than 90 mg / g, the rolling resistance is inferior, and if the orientation direction of the short fibers is the circumferential direction, the steering is controlled. It can be seen that the stability (handle response) is poor.

Production Example 3 (sidewall) NR 45 parts, BR 55 parts, short fibers (UBEPOL-HE)
15 parts of 0100), FEF 20 parts, aromatatic oil 5 parts, wax 2 parts, antioxidant 6P
PD 3 parts, stearic acid 2 parts, zinc white 3 parts, sulfur 1.
A sidewall was prepared by kneading 5 parts and accelerator CZ 1 part in a Banbury, and then extruding into a predetermined shape with an extruder. Molding and vulcanization are performed using this sidewall and the cap tread, base tread, and bead apex whose composition is shown in Table 1, except for DUNLOP SP except for the cap tread, base tread, sidewall, and bead apex.
Radial tire (A) equivalent to 7 (185 / 65R1
4) was produced. About this radial tire (1)
The rolling resistance and steering stability (handle response) were tested.

Table 4 shows the composition of the sidewall rubber, the orientation direction of the short fibers in the sidewall, and the test result of the radial tire (1).

As shown in Table 4, the radial tires (2) to (2) were prepared in the same manner as above with the same sidewall rubber composition as described above except that the composition of rubber, carbon black and short fibers and the orientation direction of the short fibers were changed. (8) was produced. Table 4 shows the results of testing rolling resistance and steering stability (handle response) of each radial tire.
Shown in.

The radial tire (4) is a tire having general rolling resistance and steering stability, and the test results of rolling resistance and steering stability (handle response) of other tires based on the radial tire (4). Represents

[0057]

[Table 4]

From the results shown in Table 4, it can be seen that steering stability (handle response) is poor when the fibers are oriented in the axial direction. Further, since the radial tire (8) has a small amount of short fibers of 5 parts, it is slightly inferior in handle responsiveness to the standard (4).

Production Example 4 (Bead Apex) NR 100 parts, short fibers (UBEPOL-HE 0100)
Medium staple fiber) 30 parts, HAF 70 parts, PR12686 resin (thermosetting resin) (Sumitomo Dures Co., Ltd.) 15
Parts, phenolic resin (adhesive) 3 parts, stearic acid 2 parts, zinc white 5 parts, sulfur 3 parts, accelerator CZ 3.8 parts,
A bead apex was prepared by kneading in a Banbury using 0.4 part of retarder PVI and then extruding into a predetermined shape. Molding and vulcanization are performed using this bead apex and the cap tread, base tread, and side wall whose compositions are shown in Table 1, so that all but the cap tread, base tread, side wall, and bead apex are equivalent to DUNLOP SP7. Radial tire (A) (185 / 65R14) was manufactured. The radial tire was tested for rolling resistance and steering stability (handle response).

Table 5 shows the composition of the bead apex, the orientation direction of the short fibers in the bead apex, and the test results of the radial tire.

As shown in Table 5, radial tires and tires were produced by the same method as described above with the same composition of the bead apex rubber as described above except that the composition of rubber, carbon black and short fibers and the orientation direction of the short fibers were changed. did. Table 5 shows the results of testing rolling resistance and steering stability (handle response) of each radial tire.
Shown in.

The radial tire is a tire having general rolling resistance and steering stability, and the test results of rolling resistance and steering stability of other tires are shown with the radial tire as a reference.

[0063]

[Table 5]

From the results shown in Table 5, when the short fibers are contained in the bead apex oriented in the axial direction or the direction intersecting the axial direction, the steering stability (handle response) is improved. Recognize.

[0065] Using the formulation T _B of the cap tread shown in Example 1 in Table 6, the cap tread was prepared by kneading and extrusion. Here, the iodine adsorption amount of carbon black N-351 is 68 mg / g. The tan δ peak temperature of this cap tread was -24 ° C.

[0066] Using the formulation B _B of the base tread shown in Table 6, and the base tread prepared by kneading and extrusion.

The sidewall formulation S _B shown in Table 6 was used to prepare a sidewall by kneading and extruding.

Bead Apex Formulation A _B Shown in Table 6
A bead apex was prepared by kneading and extruding.

By using these cap tread, base tread, sidewall and bead apex to carry out molding and vulcanization, a radial tire (185 / 65R14) corresponding to DUNLOP SP7 except for these four constituent members is obtained. Manufactured. The orientation direction of the short fibers is the axial direction in the base tread, the circumferential direction in the sidewall, and the axial direction in the bead apex. The construction of this tire is summarized in Table 7.

The radial tire was weighed and tested for rolling resistance, grip (steering stability), steering wheel response (steering stability) and riding comfort. The results are also shown in Table 7.

Table 8 shows the dimensions of each component.

Examples 2 and 3 Similar tires were produced in the same manner as in Example 1 except that the cap tread, base tread, sidewall and bead apex formulations shown in Table 7 were used. Table 7 also shows the result of performing the same test as in Example 1 on this tire. Table 8 shows the dimensions of each component.

Comparative Examples 1 to 3 Radial tires similar to those of Example 1 were produced using the formulations shown in Table 6 and the configurations shown in Table 7.

Table 7 shows the weight, rolling resistance, grip, responsiveness of the steering wheel and riding comfort of these radial tires.

The tire of Comparative Example 3 is an ordinary tire having a general rolling resistance, and the test results of each are based on Comparative Example 3.

Table 8 shows the dimensions of each component.

[0077]

[Table 6]

[0078]

[Table 7]

[0079]

[Table 8]

In Table 6, T _A , B _A , S _A , S _C ,
A _A is the conventional general formulation.

From the results of Examples 1 to 3 and Comparative Examples 1 to 3, the radial tire of the present invention is light in weight, has very low rolling resistance, and can provide excellent steering stability and riding comfort. I understand.

[0082]

Since the radial tire of the present invention is lightweight and has a low rolling resistance, it is possible to improve the fuel consumption of a vehicle equipped with the radial tire. In addition, since the steering stability (grip, steering wheel response) is excellent, safe high-speed driving can be ensured, and more excellent riding comfort can be provided.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a state in which short fibers are oriented in an axial direction of a tire in a base tread.

FIG. 2 is a schematic perspective view showing a state in which short fibers are oriented in a tire circumferential direction in a sidewall.

FIG. 3 is an explanatory diagram showing a method for producing a base tread and a sidewall.

FIG. 4 is an explanatory view showing a method of cutting out a base tread from a tubular extrudate.

[Explanation of symbols]

 1 Base Tread 2 Short Fiber 3 Sidewall 4 Tire 5 Rubber Composition 6 Calendar Roll

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B60C 15/06 B8408-3D

Claims (2)

[Claims] 1. The (A) tan δ peak temperature after vulcanization is −
A cap tread made of a rubber composition having a temperature of 30 ° C. or higher, and (B) an iodine adsorption amount of 30 with respect to 100 parts by weight of a rubber component.
A base tread comprising a rubber composition containing 30 parts by weight or less of carbon black of 90 to 90 mg / g and 10 parts by weight or more of short fibers, wherein the short fibers are oriented substantially in the axial direction of the tire, (C) rubber component Iodine adsorption amount of 30 per 100 parts by weight
A sidewall composed of a rubber composition containing 30 parts by weight or less of carbon black of 90 to 90 mg / g and 10 parts by weight or more of short fibers, the short fibers being oriented in the circumferential direction of the tire,
And (D) an iodine adsorption amount of 60 per 100 parts by weight of the rubber component
65 parts by weight or more of carbon black of 100 mg / g,
A radial tire comprising a rubber composition containing 20 parts by weight or more of short fibers, the bead apex in which the short fibers are oriented substantially in the axial direction of the tire or in a direction intersecting substantially the axial direction. . 2. The radial tire according to claim 1, wherein the sidewall is formed by an ORBI method.