RU2389741C2 - Rubber mixture for tyres, tyre component and tyre - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a rubber mixture for a tyre component, a tyre component made from said mixture and a tyre made from the tyre component. The rubber mixture for the tyre component contains a rubber component containing at least one of such rubber types as natural rubber and epoxidated natural rubber, silicon dioxide, calcium stearate and a silane binding agent. The tyre component is the coating of the frame chords, main protector, side, squeezing part, seamless belt or board filler.

EFFECT: reduced amount of materials obtained from oil sources for making the rubber mixture, longer tyre life, increased strength of the rubber after thermal ageing, increased abrasive wear resistance of the rubber.

8 cl, 6 ex, 18 dwg

Description

This application is based on Japanese patent applications No. 2007-168699, No. 2007-168700, No. 2007-168701 and No. 2007-168702, filed June 27, 2007, No. 2007-173946 and No. 2007-174018, filed July 2, 2007 to the Japan Patent Office, the full contents of which are incorporated herein by reference.

The present invention relates to a rubber composition for a tire, a tire member and a tire.

In general, for example, in passenger car tires, it is required to provide a low fuel consumption of a passenger car by reducing tire rolling resistance taking into account environmental problems and economy. In addition, tire longevity is also required during the long run of a passenger car.

In such a passenger car tire, mainly, for example, steel cord and organic fiber cord are used as the reinforcing material, and organic fiber cord is often used in the cord cord constituting the tire carcass. If organic fiber cord is used in the carcass cord to improve the adhesion properties between the carcass cord and the rubber composition covering the carcass cord, the carcass cord coating is often made from a rubber composition for coating the carcass cord (for example, see Japanese Patent No. 2006-328194 published) .

In addition, in such a tire for passenger cars, from the point of view of safety when driving, it is necessary that the tread of the tire has excellent grip characteristics. However, the low fuel consumption of a passenger car and the traction characteristics are mutually exclusive.

For this reason, it has been proposed to achieve both low fuel consumption and grip by constructing a tire tread in the form of a two-layer structure of the treadmill / tread base, forming a surface portion in contact with the tread surface, such as a treadmill, from a rubber composition, increasing the adhesion force to the road, and forming the inner part, such as the tread base, from a rubber compound providing low heat generation properties (for example, see Japanese Patent Publication No. 2006-199784, Paragraph [0003], etc.).

In addition, in recent years, with the improvement of vehicle performance and the development of a network of highways, excellent safety is required for the operation of tires for a vehicle. In order to achieve excellent stability during tire operation, it is necessary to increase the hardness of the bead apex filler, and usually a rubber composition for a bead apex containing a large amount of soot is developed (for example, see Japanese Patent Laid-Open No. 2004-339287).

It is possible to increase the hardness of the bead apex by introducing a large amount of soot into the rubber composition of the bead apex. However, there is a problem that due to an increase in the loss tangent (tanδ) in the bead filler, heating easily occurs during vehicle movement, the durability of the bead filler decreases due to heat aging, and the tire rolling resistance (resistance acting in the opposite direction tire movement during tire rotation) increases.

In addition, the bead apex is placed after molding the rubber composition for the bead apex, and if the manufacturability of molding the rubber compound for a bead apex is low, there is a problem that the bead apex will change in shape, therefore, the bead apex properties will also change.

In addition, currently commercially available tires, half or more of the total mass, are composed of components derived from oil sources. For example, in a conventional radial tire for a passenger car, as a component derived from an oil source, approximately 20% synthetic rubber, approximately 20% carbon black, relative to the total weight of the tire, and, in addition, aromatic oil and synthetic fiber, and thus 50 % or more of the total mass of the tire consists of components derived from oil sources.

However, in recent years, environmental issues have been given particular importance, and control over CO ₂ emissions has been strengthened. In addition, since the number of oil sources is limited and the number of reserves decreases year by year, it is predicted that the cost of oil will increase in the future, and there is a restriction on the use of components obtained from oil sources. Moreover, in the event of depletion of oil sources, it is predicted that there will be difficulties in the production of tires consisting of such components obtained from oil sources.

For this reason, attention is paid to environmental tires containing, as the main component, components obtained from non-oil sources (components obtained from sources other than oil) (for example, see Japanese Published Patent No. 2003-063206, etc.).

In the above ecological tire, from the point of view of reducing the number of components obtained from oil sources, it is preferable to use as many components obtained from non-oil sources as possible in the manufacture of tire elements such as carcass, tread base, grade filler, sidewall, which consists of the side of the tire, the clinch, located from the bottom to the side of the bead wire, to reduce abrasive wear between the tire rim and the bead wire, and a seamless tape (hereinafter referred to as May BShL) located on the tire breaker belt.

Accordingly, it is an object of the present invention to provide a rubber composition for a tire that can reduce the amount of materials obtained from petroleum sources, a tire member and a tire made using a rubber composition for a tire.

In addition, it is another object of the present invention to provide a rubber composition for coating a carcass cord that can reduce the amount of material used from oil sources while still providing excellent rolling resistance and tire durability.

In addition, it is another object of the present invention to provide a rubber composition for a tread base that can reduce the amount of material used from petroleum sources and at the same time provides excellent rolling resistance and tire durability.

In addition, another objective of the present invention is to provide a rubber composition for a sidewall, which can reduce the amount of material used from oil sources while maintaining good processability in an unvulcanized state, and by using which it is possible to suppress the decrease in rubber strength after heat aging that occurs after vulcanization .

In addition, another objective of the present invention is to provide a rubber composition for the crimp portion of a tire, which can reduce the amount of material used from oil sources, and which at the same time has better processability in an unvulcanized state and can provide rubber with high resistance to abrasive wear and high strength after vulcanization.

In addition, another objective of the present invention is to provide a rubber composition for BSL, which can reduce the amount of material used from oil sources, and at the same time can suppress the decrease in rubber strength due to thermal aging of BSL and improve the adhesion properties between the rubber and cord.

In addition, another objective of the present invention is to provide a rubber composition for a bead apex which can reduce the amount of material used from petroleum sources and at the same time has excellent molding processability and increases the resistance to thermal aging and the hardness of the bead apex after vulcanization.

The present invention is a rubber composition for a tire comprising a rubber component comprising at least one of components comprising natural rubber and epoxidized natural rubber, and 15 parts by weight or more silicon dioxide per 100 wt.h. rubber component, and 0.5 wt.h. or more calcium stearate per 100 parts by weight rubber component.

In addition, the rubber composition for a tire of the present invention is a rubber composition for coating a carcass cord in which the content of silicon dioxide is at least 60 parts by weight. and not more than 80 parts by weight per 100 parts by weight rubber component, the content of calcium stearate is at least 1 wt.h. and not more than 10 parts by weight per 100 parts by weight rubber component, and the mixture may further include at least 1 wt.h. and not more than 15 parts by weight silane coupling agent per 100 parts by weight rubber component.

In addition, the rubber composition for the tire of the present invention is a rubber composition for a tread base in which the content of silicon dioxide is at least 25 parts by weight. and not more than 80 parts by weight per 100 parts by weight rubber component, the content of calcium stearate is at least 1 wt.h. and not more than 10 parts by weight per 100 parts by weight of the rubber component, and the mixture may further include at least 1 part by weight and not more than 15 parts by weight silane coupling agent per 100 parts by weight rubber component

In addition, the rubber composition for the tire of the present invention is a rubber composition for a sidewall in which the content of silicon dioxide is at least 15 parts by weight. and not more than 60 parts by weight per 100 parts by weight the rubber component and the content of calcium stearate may be at least 2 wt.h. per 100 parts by weight rubber component.

In addition, the rubber composition for a tire of the present invention is a rubber composition for a crimp portion in which the silica content is not less than 60 parts by weight. per 100 parts by weight the rubber component and the content of calcium stearate may be at least 2 wt.h. and not more than 10 parts by weight per 100 parts by weight rubber component.

In addition, the rubber composition for the tire of the present invention is a rubber composition for BSL in which the content of silicon dioxide is at least 40 parts by weight. per 100 parts by weight the rubber component and the content of calcium stearate may be at least 0.5 wt.h. and not more than 10 parts by weight per 100 parts by weight rubber component.

In addition, the rubber composition for a tire of the present invention is a rubber composition for a bead apex in which the silica content is not less than 60 parts by weight. per 100 parts by weight the rubber component and the content of calcium stearate may be at least 2 wt.h. and not more than 10 parts by weight per 100 parts by weight rubber component.

In addition, the present invention is a tire member formed using a rubber composition for a tire.

Moreover, the present invention is a tire manufactured using a tire element.

The above and other objects, features, embodiments, and advantages of the present invention will become apparent from the further detailed description of the present invention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a schematic view of one example of a portion of a carcass made using a rubber composition for coating a carcass cord of the present invention;

2 is a schematic cross-sectional view illustrating part of the manufacturing steps of one example of a tire manufacturing method using a carcass made using a rubber composition for coating a carcass cord of the present invention;

3 is a schematic cross-sectional view illustrating another part of the manufacturing steps of one example of a tire manufacturing process using a carcass made using a rubber composition for coating a carcass cord of the present invention;

Figure 4 shows a schematic cross-sectional view of the upper part of one example of a tire made using a carcass made using a rubber composition for coating a carcass cord of the present invention;

5 is a schematic view illustrating the internal structure of one example of a tire made using a carcass made using a rubber composition for coating a carcass cord of the present invention;

6 is a schematic cross-sectional view of the upper left half of one example tire of the present invention;

7 shows a schematic cross-sectional view of the upper left half of one example tire of the present invention;

Fig. 8 is a schematic cross-sectional view of the upper left half of one example tire of the present invention;

Fig. 9 is a schematic view of one example of a BSL made using the rubber composition of a tire of the present invention;

FIG. 10 is a schematic cross-sectional view illustrating part of the steps of one example of a method for manufacturing a tire using the BSL shown in FIG. 9;

11 is a schematic cross-sectional view illustrating another part of the steps of one example of a method for manufacturing a tire using the BSL shown in FIG. 9;

on Fig shows a top view illustrating the relative position of the UWB and the belt belt behind the UWB, presented in Fig.1 winding;

13 is a schematic cross-sectional view of the upper part of one example tire of the present invention;

14 is a schematic view illustrating an internal structure of yet another example tire of the present invention;

15 is a schematic cross-sectional view illustrating part of the manufacturing steps of one example of a method for manufacturing a tire using a bead filler made from the rubber composition of the present invention;

FIG. 16 is a schematic cross-sectional view illustrating another part of the manufacturing steps of one example of a tire manufacturing method using a bead filler made from the rubber composition of the present invention;

17 is a schematic cross-sectional view of the upper part of one example of a tire made using a bead apex made from the rubber composition of the present invention, and

FIG. 18 shows a schematic cross sectional lead of a tire bead extender region shown in FIG. 17.

Embodiments of the present invention are described below. In the drawings of the present invention, one designation shows the same part or corresponding part.

Rubber component of tire rubber compound

In the present invention, rubber is used as the rubber component, which is any of such rubbers such as natural rubber and epoxidized rubber, or mixed rubber obtained by mixing natural rubber and epoxidized rubber. Thus, by using a rubber component containing any of such rubbers, such as natural rubber and epoxidized rubber as the rubber component, the amount of the component used to be obtained from petroleum sources can be reduced.

In this work, for example, natural rubber containing 1,4-cis-polyisoprene as the main component can be used as natural rubber, but rubber obtained by mixing 1,4-trans-polyisolrene in 1,4-, respectively, can be used. cis-polyisoprene. As such natural rubber, previously known natural rubbers and rubber, which are mainly used in the tire industry, such as RSS # 3 and TSR20, can be used.

As the epoxidized natural rubber, known rubber can be used, for example commercially available epoxidized natural rubber, or rubber obtained by epoxidizing natural rubber.

In this work, as commercially available epoxidized natural rubber, for example, ENR25 having an epoxidation degree of 25% and ENR50 having an epoxidation degree of 50% manufactured by Kumplan Guthrie Berhad can be used.

In addition, methods such as the chlorohydrin method, the direct oxidation method, the alkyl hydroperoxide method and the peroxyacid method can be used as a method for epoxidizing natural rubber. In the present work, for example, a method for reacting natural rubber with an organic peracid such as peracetic acid and permuric acid can be used, for example, as a peracid method.

In the present invention, since at least one of the components, natural rubber or epoxidized natural rubber, is included in the rubber component, at least one rubber of another type, such as butadiene rubber (BDK), styrene butadiene rubber (BSK), isoprene rubber ( IR), and butyl rubber (BK), may be part of the mixture.

Silicon dioxide in a rubber compound for a tire

In the rubber composition for the tire of the present invention, silicon dioxide is contained in an amount of 15 parts by weight or more per 100 parts by weight rubber component. When using such a structure, since the amount of soot used as a filler can be reduced, the amount of the used component obtained from oil sources can be reduced, while it is possible to obtain a sufficient reinforcing effect using silicon dioxide. As silica, a conventionally known material such as anhydrous silica and / or hydrated silica can be used.

Rubber Calcium Stearate for Tire

Among other things, the rubber composition for the tire of the present invention contains calcium stearate in an amount of 0.5 parts by weight or more per 100 parts by weight rubber component. As described above, in the present invention, since silicon dioxide as a filler is contained in an amount of 15 parts by weight or more per 100 parts by weight of the rubber component, it is likely that the processability of the mixture will deteriorate in an unvulcanized state, and the strength of the rubber after vulcanization will decrease due to aging, but when the content of calcium stearate in the amount of 0.5 wt.h. or more per 100 parts by weight the rubber component, the processability of the rubber composition in the unvulcanized state is improved.

Other rubber components for tires

In addition to the above components, various components, for example, carbon black, silane coupling agent, antioxidant, stearic acid, zinc oxide, sulfur and a vulcanization accelerator, which are mainly used in the tire industry, can accordingly be included in the rubber composition for the tire of the present invention.

Soot in a rubber compound for the tire

The rubber composition for a tire of the present invention may contain conventionally known carbon black obtained from petroleum sources. In this work, from the point of view of reducing the amount of the component obtained from oil sources, the carbon black content is preferably 25 parts by weight. or less, more preferably 5 parts by weight or less per 100 parts by weight rubber component, and most preferably the absence of soot.

Traditionally known carbon blacks such as SAF, ISAF, HAF and FEF can be used as carbon black.

Silane Coupling Agent in Tire Rubber Compound

Among other things, a silane coupling agent may be included in the rubber composition for a tire of the present invention. Here, conventionally known compounds can be used as the silane coupling agent, and examples include sulfide-based silane coupling agents such as bis (3-triethoxysilylpropyl) tetrasulfide,

bis (2-triethoxysilylethyl) tetrasulfide,

bis (3-trimethoxysilylpropyl) tetrasulfide,

bis (2-trimethoxysilylethyl) tetrasulfide,

bis (3-triethoxysilylpropyl) trisulfide,

bis (3-trimethoxysilylpropyl) trisulfide,

bis (3-triethoxysilylpropyl) disulfide,

bis (3-trimethoxysilylpropyl) disulfide,

3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide,

3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide,

2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide,

2-trimethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide,

3-trimethoxysilylpropylbenzothiazolyltetrasulfide,

3-triethoxysilylpropylbenzothiazole tetrasulfide,

3-triethoxysilylpropylmethacrylate monosulfide,

and 3-trimethoxysilylpropylmethacrylate monosulfide;

mercaptan-based silane coupling agents such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane,

2-mercaptoethyltrimethoxysilane and 2-mercaptoethyltriethoxysilane;

vinyl-based silane coupling agents such as vinyltriethoxysilane and vinyltrimethoxysilane; amine-based silane coupling agents such as 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltriethoxysilane and 3- (2-aminoethyl) aminopropyltrimethoxysilane, glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane and γ-glycidoxypropylmethyldimethoxysilane, nitro-based silane coupling agents such as 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane, and chlorine-based lancing binders such as 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane and 2-chloroethyltriethoxysilane. The silane coupling agent may be used alone or two or more kinds may be used in combination. If a silane coupling agent is included, its amount can be set appropriately.

Rubber compound for tire

As the oil, a conventionally known oil can be used, for example, industrial oil, vegetable fat or oil, or a mixture thereof. As a technical oil, for example, paraffin-based technical oil, naphthalene-based technical oil, aromatic-based technical oil can be used. As vegetable fat or oil can be used, for example, castor oil, cottonseed oil, linseed oil, soybean oil, palm oil, coconut oil, peanut oil, rosin, pine oil, pine resin, tall oil, corn oil, rice oil, safflower dyeing oil, sesame oil, olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, Australian nut oil, and Adam tree oil.

From the point of view of reducing the amount of components used from petroleum sources, it is preferable to use vegetable fat or oil as an oil.

Rubber Wax for Tire

Traditionally known waxes can be used as waxes and, for example, previously known natural-based waxes and petroleum-based waxes can be used. From the point of view of reducing the amount of components used from petroleum sources, it is preferable to use natural wax as a wax.

Rubber Antioxidant for Tire

As the antioxidant, a conventionally known antioxidant can be used, for example, such as an amine-based antioxidant, phenol-based, imidazole-based and a carbamic acid metal salt.

Stearic acid in a rubber compound for a tire

As stearic acid, a known stearic acid, for example, stearic acid, manufactured by Nippon Oil & Fats Co., Ltd. can be used.

Zinc oxide in a rubber compound for a tire

As zinc oxide, a well-known manufactured zinc oxide can be used, for example, Zinc White No.1, manufactured by MITSUI MINING & SMELTING Co., LTD.

Sulfur in the rubber compound for tires

As sulfur, a well-known, for example, powdered sulfur, manufactured by Tsurumi Chemical Industry Co., Ltd., Crystex HSOT20, manufactured by Flexis, and Sunfel EX, manufactured by SANSHIN CHEMICAL INDUSTRY CO., LTD. Can be used.

Rubber vulcanization accelerator for tire

As a vulcanization accelerator, widely known compounds can be used, for example a vulcanization accelerator containing at least one of such compounds as sulfenamide-based, thiazole-based, thiuram-based, thiourea-based, guanidine-based, dithiocarbamic acid-based , based on aminaldehyde or aldehyde ammonia, based on imidazoline and based on xanthate. As a sulfenamide-based vulcanization accelerator, sulfenamide-based compounds such as CBS (N-cyclohexyl-2-benzothiazylsulfenamide), TBBS (N-tert-butyl-2-benzothiazylsulfenamide), N, N-dicyclohexyl-2-benzothiazyls can be used , N-oxydiethylene-2-benzothiazylsulfenamide; and N, N-diisopropyl-2-benzothiazolsulfenamide. As a thiazole-based vulcanization accelerator, thiazole-based compounds such as MBT (2-mercaptobenzothiazole), DBTS (dibenzothiazyl disulfide), sodium salt, zinc salt, copper salt or cyclohexylamine salt of 2-mercaptobenzothiazole, 2- (2,4 -dinitrophenyl) mercaptobenzothiazole and 2- (2,6-diethyl-4-morpholintio) benzothiazole. As a thiuram-based vulcanization accelerator, thiuram-based compounds such as TMTD (tetramethylthiuram disulfide), tetraethyl thiuram disulfide, tetramethyl thiuram monosulfide, dipentamethylentiuram disulfide, dipentamethylumethylumethyluramethylumethimethuratiuramdisumentomethylunturamide sulfide tetramethylumethiurabutyne can be used. As a thiourea-based vulcanization accelerator, thiourea-based compounds such as thiourea, diethylthiourea, dibutylthiourea, trimethylthiourea and diorthotolithiourea can be used. Guanidine-based compounds such as diphenylguanidine, diorthotoliguanidine, triphenylguanidine, ortotolibiguanidine and diphenylguanidine phthalate can be used as a guanidine-based vulcanization accelerator. As the vulcanization accelerator based on the dithiocarbamic acids may be used based compounds such dithiocarbamic acid as ethylphenyldithiocarbamate, zinc butilfenilditiokarbamat zinc, sodium dimethyldithiocarbamate, dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, zinc diamyldithiocarbamate, zinc dipropyldithiocarbamate, zinc complex salt of zinc pentamethylenedithiocarbamate and piperidine, zinc hexadecyl (or octadecyl) isopropyl dithiocarbamate, zinc dibenzyl dithiocarbamate , Sodium diethyldithiocarbamate, piperidine pentametilenditiokarbaminovoy acid, selenium dimethyldithiocarbamate, tellurium diethyldithiocarbamate and cadmium diamyldithiocarbamate. Aminaldehyde-based or aldehyde-ammonia-based vulcanization accelerators can use aminaldehyde-based or aldehyde-ammonia-based compounds such as the reaction product of acetaldehyde and aniline, butylaldehyde-aniline condensate, the reaction product of hexamethylenetetramine and acetaldehyde-ammonia. As the imidazoline-based vulcanization accelerator, imidazoline-based compounds such as 2-mercaptoimidazoline can be used. As a xanthate-based vulcanization accelerator, xanthate-based compounds such as zinc dibutylxanthate can be used. All of these vulcanization accelerators can be used individually, or can be used in combination of two or more kinds.

Bus elements

By molding the rubber composition for a tire of the present invention into a predetermined shape, for example, various tire elements of the present invention forming a tire can be formed by extrusion in an unvulcanized state.

Tire

The tire elements of the present invention thus obtained were arranged in a predetermined position to obtain a crude tire, then the rubber composition constituting the tire elements in the crude tire was vulcanized, thereby obtaining the tire of the present invention.

Frame Coat Rubber Compound

The rubber composition for a tire of the present invention can be used as a rubber composition for coating a carcass cord.

The rubber composition for coating the carcass cord of the present invention comprises at least 60 parts by weight of and not more than 80 parts by weight silicon dioxide, not less than 1 wt.h. and not more than 10 parts by weight calcium stearate, not less than 1 wt.h. and not more than 15 parts by weight silane coupling agent per 100 parts by weight rubber component.

Silicon dioxide in the rubber composition of the coating of the carcass cord

In the rubber composition of the coating of the cord of the carcass of the present invention contains at least 60 parts by weight and not more than 80 parts by weight silica per 100 parts by weight rubber component. Here, if the content of silicon dioxide is at least 60 parts by weight per 100 parts by weight rubber component, there is a tendency to reduce the amount of material obtained from oil. If the content of silicon dioxide is not more than 80 parts by weight, there is a tendency to improve the rolling resistance of a tire made using a rubber composition in the coating of a carcass cord of the present invention. As the silica, the same silica can be used as in the rubber composition for the tire.

In addition, from the point of view of improving the processability of extrusion (reduce shrinkage), it is more preferable that the content of silicon dioxide is at least 65 parts by weight. per 100 parts by weight rubber component.

In addition, in order not to increase the Mooney viscosity, it is more preferable that the content of silicon dioxide is not more than 75 parts by weight. per 100 parts by weight rubber component.

In addition, the specific surface area of silicon dioxide, measured from nitrogen adsorption by the BET method (hereinafter referred to as the “specific surface area by BET”), is preferably not less than 70 m ² / g, more preferably not less than 80 m ² / g. If the BET specific surface area of the silica is at least 70 m ² / g, in particular at least 80 m ² / g, the reinforcing effect of the silica becomes sufficient.

In addition, the BET specific surface area of silica is preferably not more than 250 m ² / g, more preferably not more than 240 m ² / g. If the BET specific surface area of silicon dioxide is not more than 250 m ² / g, in particular not more than 240 m ² / g, there is a tendency that the decrease in the Mooney viscosity of the rubber composition of the carcass cord coating of the present invention can be suppressed, and the processability of the rubber is improved mixtures for coating the carcass cord of the present invention.

In addition, the BET specific surface area of silicon dioxide can be measured by the method in accordance with ASTM-B-4820-93.

Silane coupling agent in a rubber compound for coating a carcass cord

In the rubber composition for coating the carcass cord of the present invention contains at least 1 wt.h. and not more than 15 parts by weight silane coupling agent per 100 parts by weight rubber component. If the content of the binding agent is not less than 1 wt.h. per 100 parts by weight of the rubber component, there is a tendency to improve the strength of the rubber after vulcanization and to improve the durability of the tire if the content of the silane coupling agent is not more than 15 parts by weight, there is a tendency that the strength of the rubber after vulcanization will not be high and the rolling resistance of the tire can be improved. As the silane coupling agent, the same silane coupling agent can be used as in the rubber composition for a tire.

In addition, it is more preferred that the content of the silane coupling agent is at least 2 parts by weight. per 100 parts by weight rubber component. If the content of the binding agent is at least 2 parts by weight per 100 parts by weight rubber component, the effect of adding a silane coupling agent will be sufficient.

In addition, it is more preferable that the content of the silane coupling agent is not more than 14 parts by weight. per 100 parts by weight rubber component. If the content of the silane coupling agent is not more than 14 parts by weight per 100 parts by weight rubber component, the cost may be reduced, and at the same time, the effect of adding a silane coupling agent will be sufficient.

Calcium stearate in a rubber compound for coating a carcass cord

In the rubber composition for coating the carcass cord of the present invention contains at least 1 wt.h. and not more than 10 parts by weight calcium stearate per 100 parts by weight rubber component. If the content of calcium stearate is at least 1 wt.h. and not more than 10 parts by weight per 100 parts by weight the rubber component, the processability of the rubber composition for coating the carcass cord of the present invention is improved, and at the same time, the strength of the rubber after vulcanization can be excellent. Here, the same calcium stearate can be used as the calcium stearate as in the rubber composition for the tire.

In addition, it is more preferable that the content of calcium stearate is at least 2 parts by weight. per 100 parts by weight rubber component. If the content of calcium stearate is at least 2 parts by weight per 100 parts by weight rubber component, the effect of adding stearate will be sufficient.

Moreover, it is more preferable that the content of calcium stearate is not more than 9 parts by weight. per 100 parts by weight rubber component. If the content of calcium stearate is not more than 9 parts by weight per 100 parts by weight rubber component, there is a tendency that the ratio between rolling resistance and rubber strength will be excellent.

Soot in a rubber compound for coating a carcass cord

In the rubber composition for coating the carcass cord of the present invention, the previously known carbon black obtained from oil sources can be included in the rubber composition, and from the point of view of reducing the amount of material used from oil sources, the carbon black content is preferably not more than 25 parts by weight, more preferably not more than 5 parts by weight per 100 parts by weight rubber component, most preferably the absence of soot. In addition, if carbon black is included, the same carbon black may be included as in the rubber composition for the tire.

Other components in the rubber composition for coating the carcass cord

In addition to the above materials, various other materials, for example, oil, wax, antioxidant, stearic acid, zinc oxide, sulfur and a vulcanization accelerator, which are mainly used in the tire industry, can be respectively added to the rubber composition for coating the carcass cord of the present invention . In addition, if these components are added, they may be the same as in the rubber composition for the tire.

A method of manufacturing a rubber composition for coating a carcass cord

The rubber composition for coating the carcass cord of the present invention can be obtained by mixing the above materials, mixing the materials using a well-known open-type Banbury mixer, pressure mixer or continuous mixer.

Fabrication of a carcass using a rubber compound for coating a carcass cord

1 is a schematic view of one example of a carcass made using a rubber composition for coating a carcass cord of the present invention. Here, the carcass 4 has such a structure that a plurality of carcass cords 11 are embedded in the plate rubber composition 15 to cover the carcass cord of the present invention.

A carcass 4 made using a rubber composition for coating a carcass cord of the present invention can be obtained, for example, by first arranging the carcass cords 11 in parallel and in this state by applying unvulcanized rubber composition 15 to them to cover the carcass cord of the present invention.

In the present invention, conventional known cords can be used as the frame cord 11, for example, a cord made of organic fiber or steel can be used.

A tire made using a carcass made using a rubber composition for coating a carcass cord

One example of a method for manufacturing a tire using a carcass made using a rubber composition for coating a carcass cord of the present invention is described below.

First performed, as described above, the frame is annularly wound on the outer longitudinal surface of a conventional known cylindrical drum.

Here, the carcass can be made, for example, by applying a rubber composition for coating a carcass cord of the present invention on the upper and lower surfaces of a plurality of carcass cords made of threads, for example, polyester, to embed a plurality of carcass cords in a rubber composition for coating a carcass cord of the present invention.

Then, as schematically shown in cross section in FIG. 2, the bead wire 5 obtained by twisting a plurality of wires in the form of a ring is driven along the outer longitudinal surface from both ends of the ring-shaped frame 4 and at the same time a filler 7 of the bead is installed, both ends of the frame 4 are bent inward to enclose the bead wire 5 and the bead filler 7 between the bend 4a and the straight portion 4b of the frame 4.

Then, as schematically shown in cross section in FIG. 3, the frame 4, in which the bead wire 5 and the bead filler 7 are wrapped around the edges, is inflated in the form of a toroid. After that, the first belt 6b and the second belt 6a are layered in this order not on the outer longitudinal surface in the center of the frame 4, thereby forming a belt 6.

After that, the raw tire is assembled in the usual known manner, and the assembled raw tire is placed in the tire forming mold and the unvulcanized rubber mixture comprising each of the parts is tread, tread, sidewall, belt, BSL, inner liner, carcass, and the bead filler, getting the finished tire.

In the above, the description of the stages of assembly of the tread, sidewall, BSH and the inner gasket is omitted.

A schematic cross-sectional view of the upper part of one example of a tire made as described above is shown in FIG. 4. In addition, FIG. 5 is a schematic view for illustrating the internal structure of another example of a tire made using a carcass made using a rubber composition for coating a carcass cord of the present invention.

Here, as shown in FIGS. 4 and 5, in a tire manufactured as described above, a sidewall 9 is formed on a side surface of the carcass 4, into which the bead wire 5 and the bead filler 7 are wrapped at both edges.

In addition, in the center of the outer longitudinal surface of the carcass 4, the belt 6 is assembled, obtained by layering the first belt layer 6b and the second belt layer 6a, in this order, and at the same time, the BSL 1 is set so as to cover the end of the belt 6 and a tread 8 is formed. serving as the tire-ground contact portion, on the outer longitudinal side of the belt 6 and the BSL 1. In addition, an inner gasket 10 is formed in the inner longitudinal surface of the carcass 4 to prevent gas such as air from leaking out while screeching inside the frame 4.

Since a tire with the above structure is manufactured using a carcass made using a rubber composition for coating a carcass cord of the present invention, the rolling resistance of the tire and the tire durability will be excellent.

Moreover, since the amount of material used from oil sources is reduced in the tire of the above construction, an environmentally friendly tire is obtained taking into account the environment, and it is also possible to prepare for lower oil reserves in the future.

From the point of view of reducing the amount of material used, obtained from oil sources, it is obvious that it is preferable to produce other parts of the tire, in addition to the carcass, using materials obtained from non-oil sources in the greatest possible amount.

Also, in the foregoing, an example tire is provided for passenger cars, but this does not limit the present invention, but tires used in various vehicles such as passenger cars, trucks, buses and heavy trucks can be obtained.

Rubber compound for tread base

The above rubber composition for a tire of the present invention can be used, for example, as a rubber composition for a tread base.

The rubber composition for the tread base of the present invention contains at least 25 parts by weight and not more than 80 parts by weight silicon dioxide, not less than 1 wt.h. and not more than 10 parts by weight calcium stearate and not less than 1 wt.h. and not more than 15 parts by weight silane coupling agent per 100 parts by weight rubber component.

Silicon dioxide in rubber compound for tread base

The rubber composition for the tread base of the present invention includes at least 25 parts by weight and not more than 80 parts by weight silica per 100 parts by weight rubber component. If the content of silicon dioxide is at least 25 parts by weight per 100 parts by weight of the rubber component, there is a tendency that the amount of material used from petroleum sources can be reduced, and there is a tendency that the reinforcement of the tire with silicon dioxide becomes sufficient, the strength of the rubber improves, and the durability of the tire is increased. On the other hand, if the content of silicon dioxide is not more than 80 parts by weight per 100 parts by weight of the rubber component, there is a tendency that the rolling resistance of a tire made using a rubber composition for a tread base of the present invention will improve. As the silica, the same silica can be used as in the rubber composition for the tire.

In addition, from the point of view of improving the processability of extrusion (reduction of shrinkage), the content of silicon dioxide is preferably not less than 30 parts by weight, more preferably not more than 40 parts by weight per 100 parts by weight rubber component.

In addition, from the point of view of the absence of increasing Mooney viscosity, the content of silicon dioxide is preferably not more than 70 parts by weight, more preferably not more than 60 parts by weight per 100 parts by weight rubber component.

In addition, the BET specific surface area of the silica is preferably not less than 70 m ² / g, more preferably not less than 80 m ² / g. If the BET specific surface area of silicon dioxide is not less than 70 m ² / g, in particular not less than 80 m ² / g, there is a tendency that the reinforcing effect of silicon dioxide will be sufficient.

In addition, the BET specific surface area of silica is preferably not more than 250 m ² / g, more preferably not more than 240 m ² / g. If the BET specific surface area of the silica is not more than 250 m ² / g, in particular not more than 240 m ² / g, there is a tendency that a decrease in the Mooney viscosity of the rubber composition of the tread base of the present invention can be suppressed, and the processability of the rubber composition is improved for the base of the tread of the present invention.

In addition, the BET specific surface area of silicon dioxide can be measured by the method in accordance with ASTM-B-4820-93.

Silane coupling agent in rubber compound for tread base

In the rubber composition for the tread base of the present invention contains at least 1 wt.h. and not more than 15 parts by weight silane coupling agent per 100 parts by weight rubber component. If the content of the silane coupling agent is at least 1 part by weight per 100 parts by weight rubber component, there is a tendency to improve the strength of rubber after vulcanization and improve durability; if the content is not more than 15 parts by weight, there is a tendency that the strength of the rubber after vulcanization will not be too high and the rolling resistance of the tire will improve. As a silane coupling agent, the same silane coupling agent can be used as in the rubber composition for a tire.

In addition, it is more preferred that the content of the silane coupling agent is at least 2 parts by weight. per 100 parts by weight rubber component. If the content of the silane coupling agent is at least 2 parts by weight per 100 parts by weight rubber component, there is a tendency that the effect of adding a silane coupling agent will be sufficient and the abrasion resistance of rubber after vulcanization will become better.

In addition, it is more preferable that the content of the silane coupling agent is not more than 14 parts by weight. per 100 parts by weight rubber component. If the content of the silane coupling agent is not more than 14 parts by weight per 100 parts by weight rubber component, the cost can be reduced, and at the same time, the effect of adding a silane coupling agent will be sufficient.

Calcium stearate in rubber compound for tread base

In the rubber composition for the tread base of the present invention contains at least 1 wt.h. and not more than 10 parts by weight calcium stearate per 100 parts by weight rubber component. If the content of calcium stearate is at least 1 wt.h. per 100 parts by weight rubber component, there is a tendency to improve the manufacturability of the rubber composition for the tread base of the present invention, and at the same time, the strength of the rubber after vulcanization can be superior. Here, the same calcium stearate can be used as the calcium stearate as in the rubber composition for the tire.

In addition, it is more preferable that the content of calcium stearate is at least 2 parts by weight. per 100 parts by weight rubber component. If the content of calcium stearate is at least 2 parts by weight per 100 parts by weight rubber component, the effect of adding calcium stearate will be sufficient.

Moreover, it is more preferable that the content of calcium stearate is not more than 9 parts by weight. per 100 parts by weight rubber component. If the content of calcium stearate is not more than 9 parts by weight per 100 parts by weight rubber component, the ratio of the characteristics of rolling resistance and rubber strength will be excellent.

Soot in rubber compound for tread base

The rubber composition for the tread base of the present invention may include previously known carbon black obtained from oil sources, and from the point of view of reducing the amount of material used from oil sources, the carbon black content is preferably not more than 25 parts by weight. more preferably not more than 5 parts by weight per 100 parts by weight rubber component, most preferably the absence of soot. Here, soot can be used the same soot as in the rubber composition for tires.

Other components in the rubber compound for the tread base

Other materials, for example, oil, wax, antioxidant, stearic acid, zinc oxide, sulfur, and a vulcanization accelerator, which are mainly used in the tire industry, can accordingly be included in the rubber composition for the tread base of the present invention. In addition, if these components are included, then the same components can be used as in the rubber composition for the tire.

A method of manufacturing a rubber compound for a tread base

The rubber composition for the tread base of the present invention can be obtained by mixing the above materials, mixing them using a conventionally known open type mixer, Banbury mixer, pressure mixer or continuous mixer.

Tread base made using rubber compound for tread base

The tread base can be formed by extruding the rubber composition for the tread base of the present invention in an unvulcanized state.

A tire made using a tread base made using a rubber composition for a tread base

A tire can be obtained by making a raw tire by mounting a tread base formed from a rubber composition for a tread base of the present invention and other tire elements at predetermined positions and then vulcanizing the rubber composition constituting the raw tire elements.

Figure 6 presents a schematic cross-sectional view of the upper left half of one example of a tire made as described above. Here, the tire 61 includes a tread treadmill 62a, which is the ground contact surface of the tire 61, a tread base 62b located inside in the radial direction of the tire relative to the tread treadmill 62a, one pair of sidewalls 63 forming a side surface of the tire 61 extending inwardly in the radial the direction of the tire from both edges of the tread base 62b, and the bead ring 65 located inside in the radial direction of the tire with respect to each sidewall 63. In addition, the carcass 66 forms a jumper between the bead rings 65, 65, and at the same time, the belt 72 is located on the outside of the frame 66 and on the inside of the tread base 62b.

The carcass 66 may be formed, for example, from a sheet of rubber, where a plurality of cords are at an angle, for example, 70-90 ° relative to the equator of the CO tire (an imaginary line formed by a single rotation of the center of the width of the outer longitudinal surface of the tire 1 in the longitudinal direction of the outer longitudinal surface of the tire 1 ) embedded in the rubber compound. In addition, the carcass 66 bends from the inside to the outside in the axial direction of the tire, the bead ring 65 from the tread base 62b through the sidewall 63.

Belt belt 67 may be formed from a sheet of rubber, where a plurality of cords at an angle of, for example, 40 ° relative to the equator of the CO tire are embedded in the rubber composition.

In addition, a BSL (not shown) can be included in the tire 61 to suppress peeling of the belt 67. In this work, the BSL consists, for example, of a sheet of rubber, where many cords are embedded in the rubber mixture, and can be installed by spiral winding on the outside the surface of the belt 72 is approximately parallel to the equator of the CO tire.

In addition, a bead filler 63 is formed in the tire 61, extending outward in the tire radial direction from the bead ring 65, and at the same time, an inner gasket 69 is located on the inner side of the carcass 66, and the outer side of the carcass bend 66 is covered with sidewall 63 and crimp portion 64 extending in the radial direction of the tire from the sidewall 63.

The tire 61 of FIG. 6 is a passenger car tire. The present invention is not limited to this tire, but it is used in various vehicles, such as passenger cars, trucks, buses and heavy trucks.

Since in the rubber composition for the tread base of the present invention, silicon dioxide, a silane coupling agent and calcium stearate are added to the rubber component in the above appropriate amounts, respectively, in the tire using the tread base formed using the rubber composition for the tread base of the present invention The tire rolling resistance can be reduced and, in addition, excellent tire durability can be obtained. Therefore, it is preferable to use a rubber composition for a tread base of the present invention for a tire tread base.

In addition, since the amount of material used from petroleum sources, such as soot, in the tread base 62b is reduced, the tire 61 having the above construction can be considered environmentally friendly, taking into account the environment, and one can also be prepared for a possible reduction in petroleum stocks in the future.

From the point of view of reducing the amount of material obtained from oil sources, it is obvious that it is preferable to produce as many tire elements as possible using materials obtained not from oil sources, and not only the tread base 62b.

In addition, in view of the foregoing, an example passenger car tire does not limit the present invention, but tires used for various vehicles such as passenger cars, trucks, buses and heavy trucks can be obtained.

Rubber compound for sidewall

The rubber composition for a tire of the present invention can be used, for example, as a rubber composition for a sidewall.

The rubber composition for the sidewall of the present invention includes at least 15 parts by weight and not more than 60 parts by weight silicon dioxide and not more than 2 parts by weight calcium stearate per 100 parts by weight rubber component.

Based on in-depth studies, the applicants determined that the use of a rubber compound having a composition comprising a rubber component containing at least one of rubbers such as natural rubber and epoxidized natural rubber, and at the same time including 100 parts by weight the rubber component is not less than 15 parts by weight and not more than 60 parts by weight silicon dioxide and not less than 2 parts by weight Calcium stearate not only reduces the amount of material used from petroleum sources, but also improves processability in an unvulcanized state, and a decrease in strength after heat aging can be suppressed. Applicants believe that if the sidewall is formed using this rubber composition, the manufacturability and properties of the sidewall can be excellent as a result of the implementation of the present invention.

In addition, if both natural rubber and epoxidized natural rubber are used as the rubber component for the sidewall of the present invention, the content of the epoxy groups of the epoxidized natural rubber is preferably 5 wt.% Or more, more preferably 10 wt.% Or more. If the content of the epoxy groups of the epoxidized natural rubber is 5 wt.% Or more, relative to the total mass of the rubber component, and in particular 10 wt.% Or more, there is a tendency that the flexural strength characteristics of the sidewall formed using the rubber composition for the sidewall of the present invention will be excellent.

In addition, if both natural rubber and epoxidized natural rubber are used as the rubber component for the sidewall of the present invention, the epoxy groups of the epoxidized natural rubber are preferably 85 wt.% Or less, more preferably 60 wt.%. or less, more preferably 50 wt.% or less. If the content of the epoxy groups of the epoxidized natural rubber is more than 50 wt.%, In particular more than 80 wt.%, More than 65 wt.%, There is a tendency that the tire containing the sidewall formed using the rubber composition for the sidewall is presently heated invention, when driving reaches high temperatures.

In addition, in the rubber composition for the sidewall of the present invention, if at least one of the rubbers, such as natural rubber and epoxidized natural rubber, is included in the rubber component, then at least one of the other types of rubber, such as butadiene rubber ( BdK), styrene butadiene rubber (BSK), isoprene rubber (IR) and butyl rubber (BK) may be included.

However, rubber, with the exception of natural rubber and epoxidized natural rubber, may be included in the rubber component in the rubber composition for the sidewalls of the present invention in an amount of, preferably, 20 wt.% Or less, more preferably 10 wt.% Or less, even more preferably 5 wt.% or less, most preferably 0 wt.%.

Silicon dioxide in the rubber composition for the sidewall

The rubber composition for the sidewall of the present invention contains at least 15 parts by weight and not more than 60 parts by weight silica per 100 parts by weight rubber component. By adopting such a composition, the amount of carbon black used as a filler can be reduced, and the amount of carbon black obtained from oil can be reduced, and at the same time, a sufficient reinforcing effect of silicon dioxide can be obtained. In addition, if the content of silicon dioxide is not more than 60 parts by weight per 100 parts by weight of the rubber component, there is a tendency that the bending strength characteristics will become better and the thermal properties of the tire will become better. It should be noted that silicon dioxide can be used the same silicon dioxide as in the rubber composition for tires.

Here, the content of silicon dioxide is preferably 30 parts by weight. or more per 100 parts by weight rubber component. If the content of silicon dioxide is 30 parts by weight or more per 100 parts by weight of the rubber component, there is a tendency that the strength of the rubber after vulcanization of the rubber composition for the sidewall of the present invention improves.

In addition, the BET specific surface area of the silica is preferably not less than 80 m ² / g, more preferably not less than 100 m ² / g. If the BET specific surface area of the silica is not less than 80 m ² / g, in particular not less than 100 m ² / g, there is a tendency that the rubber strength is improved after vulcanization of the rubber composition for the sidewall of the present invention.

Furthermore, the BET specific surface area of the silica is preferably not more than 230 m ² / g, more preferably not more than 210 m ² / g. If the BET specific surface area of silicon dioxide is not more than 230 m ² / g, in particular not more than 210 m ² / g, there is a tendency that the processability of the rubber composition of the present invention is improved.

In addition, the BET specific surface area of silicon dioxide can be measured by the method in accordance with ASTM-D-4320-93.

Calcium stearate in the rubber composition for the sidewall

In the rubber composition for the sidewalls of the present invention contains at least 2 parts by weight calcium stearate per 100 parts by weight rubber component. As described above, since in the rubber composition for the sidewall of the present invention, the content of silicon dioxide as a filler is at least 15 parts by weight and not more than 60 parts by weight, there is a possibility of deterioration of the processability of the mixture in the unvulcanized state and a decrease in the strength of the rubber after vulcanization due to heat aging. However, when the content of calcium stearate 2 wt.h. or more per 100 parts by weight of the rubber component, there is a tendency that the processability of the mixture in the unvulcanized state will be better and the reduction in the strength of the rubber after vulcanization due to heat aging can be effectively suppressed. Here, the same calcium stearate can be used as the calcium stearate as in the rubber composition for the tire.

In particular, when the rubber component contains epoxidized natural rubber, if calcium stearate is included in the amount of 2 parts by weight per 100 parts by weight of the rubber component, there is a tendency that sidewall characteristics such as flexural strength and cut resistance will be excellent.

In addition, it is more preferred that the content of calcium stearate is 5 parts by weight. or more per 100 parts by weight rubber component. If the content of calcium stearate is 5 wt.h. or more per 100 parts by weight of the rubber component, there is a tendency that the cut resistance of the sidewall formed using the rubber composition for the sidewall of the present invention after heat aging will be excellent.

Moreover, the content of calcium stearate is 15 wt.h. or less, more preferably 10 parts by weight or less, per 100 parts by weight rubber component. If the content of calcium stearate is 15 wt.h. or less, in particular 10 parts by weight or less, per 100 parts by weight of the rubber component, there is a tendency that the processability of the rubber composition for the side wall of the present invention and the cut resistance of the side wall formed using the rubber composition for the side wall of the present invention after heat aging will be excellent.

Soot in rubber compound for sidewall

The previously known carbon black obtained from petroleum sources may be included in the rubber composition for a sidewall of the present invention. Here, from the point of view of reducing the amount of material used from oil sources, the carbon black content is preferably not more than 25 parts by mass, more preferably not more than 5 parts by mass. per 100 parts by weight rubber component, most preferably the absence of soot. It should be noted that if soot is included, the same soot can be used as soot as in the rubber composition for a tire.

Silane coupling agent in the rubber composition for the sidewall

A silane coupling agent may be included in the rubber composition for the sidewall of the present invention. If a silane coupling agent is included in the rubber composition for a side wall of the present invention, the content of the silane coupling agent is preferably 6 parts by weight. or more, more preferably 8 parts by weight or more, per 100 parts by weight silica. If the content of the silane coupling agent is 6 parts by weight or more, in particular 8 parts by weight or more, per 100 parts by weight silicon dioxide, there is a tendency to improve the strength of rubber after vulcanization of the rubber composition for the sidewalls of the present invention. In addition, the same silane coupling agent can be used as the silane coupling agent as in the rubber composition for the tire.

In addition, if a silane coupling agent is included in the rubber composition for a side wall of the present invention, the content of the silane coupling agent is preferably 15 parts by weight. or less, more preferably 10 parts by weight or less, per 100 parts by weight silica. If the content of the silane coupling agent is 15 parts by weight or less, in particular 10 parts by weight or less, per 100 parts by weight silica, there is a tendency that the processability of the rubber composition for the sidewalls of the present invention will be excellent and, at the same time, the cost can be reduced.

Other rubber components for sidewall

In addition to the materials mentioned above, various materials, such as oil, wax, antioxidant, stearic acid, zinc oxide, sulfur and a vulcanization accelerator, which are mainly used in the tire industry, can be appropriately included in the rubber composition for the sidewalls of the present invention. In addition, if these components are included, then the same components can be used as in the rubber composition for the tire.

A method of manufacturing a rubber composition for a sidewall

The rubber composition for a sidewall of the present invention can be obtained by mixing the above materials by mixing them using a conventionally known open type mixer, Banbury mixer, pressure mixer or continuous mixer.

Sidewall made using rubber compound for sidewall

The sidewall can be formed by extruding the rubber composition for the sidewalls of the present invention in an unvulcanized state.

A tire made using a sidewall made using a rubber composition for a sidewall

A tire can be obtained by manufacturing a crude tire by installing a sidewall manufactured as described above and other tire elements at predetermined positions, followed by vulcanization of the rubber composition constituting the raw tire elements.

7 is a schematic cross-sectional view of the upper left half of one example of a tire made as described above. Here, the tire 71 is characterized in that the sidewall 63 is made using the rubber composition for the sidewall of the present invention.

Here, the tire 71 includes a tread 62, which is the ground surface of the tire 71, one pair of sidewalls 63 extending in the radial direction of the tire from both ends of the tread 62, forming a side portion of the tire 71, and a bead ring 65 located on the inner end of each side of the sidewall 63. In addition, the frame 66 forms a jumper between the bead rings 65, 85 and, at the same time, the belt belt 67, having a constricting action to strengthen the tread 62, is located on the outside of the frame 66 and on the inside of the tread 62.

The carcass 66 may be formed, for example, from a rubber sheet, where a plurality of cords are at an angle of, for example, 70-90 ° relative to the equator of the CO tire (an imaginary line formed by a single rotation of the center of the width of the outer longitudinal surface of the tire 71 in the longitudinal direction of the outer longitudinal surface of the tire 71 ) embedded in the rubber compound. In addition, the carcass 66 bends from the inside to the outside in the axial direction of the tire side ring 65 from the tread 62 through the sidewall 63.

Belt 67 may be formed from a sheet of rubber, where a plurality of cords at an angle of, for example, 40 ° or less relative to the equator of the CO tire are embedded in the rubber composition.

In addition, a bus bar (not shown) may be included in the tire 71 to suppress peeling of the belt 67. Here, the bus bar consists, for example, of a sheet of rubber, where a plurality of cords are embedded in the rubber composition, and can be installed by spiral winding on the outer surface the belt 67 is approximately parallel to the equator of the CO tire.

In addition, a bead filler 68 is formed in the tire 71, extending outward in the tire radial direction from the bead ring 65, and at the same time, an inner gasket 69 is located on the inner side of the carcass 66, and the outer side of the carcass bend 66 is covered with a sidewall 63 and a crimp portion 64 extending in the radial direction of the tire from the sidewall 63. In addition, the sidewall 63 is formed from a vulcanized rubber composition for the sidewall of the present invention.

Since the tire 71 has the above construction so that the sidewall 63 is formed using the rubber composition of the present invention, the reduction in the rubber strength of the sidewall 63 due to heat aging can be suppressed, the tire durability can be extended, and at the same time, the stability of the vehicle can to be improved.

The tire shown in FIG. 7 is a tire for passenger cars, but the present invention is not limited to this tire and can be used, for example, for passenger cars, trucks, buses and heavy trucks.

In addition, since the amount of material used from oil sources is reduced in the tire 71 with the above construction, the tire can be considered environmentally friendly, taking into account the environment, and one can be prepared to reduce oil reserves in the future.

In addition, from the point of view that the amount of the component obtained from oil sources is reduced, it is obvious that it is preferable to use as many components obtained not from oil sources in the tire elements, and not only in the sidewall 63.

Rubber compound for crimp

The rubber composition for a tire of the present invention can be used, for example, as a rubber composition for a crimp portion.

The rubber composition for the crimp part of the present invention has a composition containing at least 60 parts by weight silicon dioxide and not less than 2 parts by weight and not more than 10 parts by weight calcium stearate per 100 parts by weight rubber component.

As a result of deep research, the applicants determined that the use of a rubber compound having a composition comprising a rubber component containing at least one of such rubbers as natural rubber and epoxidized natural rubber, and at the same time included per 100 wt. hours the rubber component is not less than 60 parts by weight silicon dioxide and not less than 2 parts by weight and not more than 10 parts by weight calcium stearate, not only reduces the amount of material used from oil sources, but also rubber can be made that has good processability in an unvulcanized state and has high abrasion resistance and high strength after vulcanization. Applicants believe that if the crimp portion is formed using this rubber composition, the workability and properties of the crimp portion may be excellent resulting from the implementation of the rubber composition for the crimp portion of the present invention.

In addition, if both natural rubber and epoxidized natural rubber are contained as the rubber component for the crimp portion of the present invention, the epoxy content of the epoxidized natural rubber is preferably 5% by weight. or more, more preferably 10 wt.% or more. If the content of the epoxy groups of the epoxidized natural rubber is 5 wt.% Or more, relative to the total weight of the rubber component, in particular 10 wt.% Or more, there is a tendency that the rubber after vulcanization of the rubber composition of the present invention will be superior in abrasion resistance when high rigidity in these conditions.

Furthermore, if both natural rubber and epoxidized natural rubber are used as the rubber component for the crimp portion of the present invention, the epoxy content of the epoxidized natural rubber is preferably 65 wt.% Or less, more preferably 60 wt.%. or less, even more preferably 50 wt.% or less, relative to the total weight of the rubber component. If the content of the epoxy groups of the epoxidized natural rubber is more than 50 wt.%, In particular more than 60 wt.%, Moreover, more than 65 wt.%, There is a tendency that the tire containing the crimp formed using the rubber composition for crimping is heated parts of the present invention, when moving will reach high temperatures in these conditions.

In addition, in the rubber composition for the crimp part of the present invention, if at least one of the rubbers, such as natural rubber and epoxidized natural rubber, is included in the rubber component, at least one of the other types of rubber, such as butadiene rubber (BDK), styrene butadiene rubber (BSC), isoprene rubber (IR) and butyl rubber (BK) may be included.

Rubber, in addition to natural rubber and epoxidized natural rubber, can be included in the rubber component in the rubber composition for the crimp of the present invention, but its content is preferably 20 wt.% Or less, whiter, preferably 10 wt.% Or less, even more preferably 5 wt.% or less, most preferably 0 wt.%.

Silicon dioxide in rubber compound for crimp

In the rubber composition for the crimp part of the present invention contains 60 parts by weight or more silicon dioxide per 100 wt.h. rubber component. By adopting such a composition, since the amount of soot used as a filler can be reduced, the amount of component used, obtained from oil, can be reduced and, at the same time, a sufficient reinforcing effect due to silicon dioxide can be obtained. As the silica, the same silica can be used as in the rubber composition for the tire.

Here, the content of silicon dioxide is preferably 100 parts by weight. or less, more preferably 90 parts by weight or less, per 100 parts by weight rubber component. If the content of silicon dioxide is 100 parts by weight or less per 100 parts by weight the rubber component, in particular 90 parts by weight or less, there is a tendency that the processability of the rubber composition for the crimp portion of the present invention will improve.

Here, the BET specific surface area of the silica is preferably 80 m ² / g or more, more preferably 100 m ² / g or more. If the BET specific surface area of silicon dioxide is 80 m ² / g or more, in particular 100 m ² / g or more, there is a tendency that the strength of the rubber after vulcanization of the rubber composition for the crimp portion of the present invention will increase.

In addition, the BET specific surface area of the silica is preferably 230 m ² / g or less, more preferably 210 m ² / g or less. If the BET specific surface area of silicon dioxide is 230 m ² / g or less, in particular 210 m ² / g or less, there is a tendency that the processability of the rubber composition for the crimp portion of the present invention will become better.

In addition, the BET specific surface area of silicon dioxide can be measured by the method in accordance with ASTM-D-4820-93.

Rubber Calcium Stearate for Crimp

In the rubber composition for the crimp part of the present invention contains at least 2 parts by weight and not more than 10 parts by weight calcium stearate per 100 parts by weight rubber component. As described above, since the rubber composition for the crimp part of the present invention contains as a filler silicon dioxide in an amount of at least 60 parts by weight per 100 parts by weight rubber component, there is a tendency that manufacturability in a non-vulcanized state will deteriorate. However, when the content of calcium stearate is not less than 2 parts by weight and not more than 10 parts by weight per 100 parts by weight of a rubber component, this processability in an unvulcanized state can be improved, and rubber having a high abrasion resistance and high strength can be obtained. As calcium stearate, the same calcium stearate can be used as in the rubber composition for a tire.

In addition, the content of calcium stearate is preferably at least 5 parts by weight. per 100 parts by weight rubber component. If the content of calcium stearate is at least 5 parts by weight per 100 parts by weight of the rubber component, there is a tendency that the processability of the rubber component of the crimp part of the present invention and the abrasion resistance of the rubber after vulcanization will be excellent.

Moreover, the content of calcium stearate is preferably not more than 7 parts by weight. per 100 parts by weight rubber component.

Soot in rubber compound for crimp

The previously known carbon black obtained from oil sources may be included in the rubber composition for the crimp portion of the present invention. However, from the point of view of reducing the amount of the component used, obtained from oil sources, the carbon black content is preferably not more than 25 parts by mass, more preferably not more than 5 parts by mass. per 100 parts by weight rubber component, most preferably the absence of soot. It should be noted that if soot is included, the same soot can be used as soot as in the rubber composition for the tire.

The silane coupling agent in the rubber composition for the crimp part

In the rubber composition for the crimp portion of the present invention, a silane coupling agent may be included. If the silane coupling agent is included in the rubber composition for the crimp portion of the present invention, the content of the silane coupling agent is preferably at least 6 parts by weight, more preferably at least 8 parts by weight. per 100 parts by weight silica. If the content of the silane coupling agent is not less than 6 parts by weight, in particular not less than 8 parts by weight, per 100 parts by weight silica, there is a tendency that the strength of the rubber after vulcanization of the rubber composition for the crimp of the present invention and the abrasion resistance will be excellent.

In addition, if the silane coupling agent is included in the rubber composition for the crimp portion of the present invention, the content of the silane coupling agent is preferably not more than 15 parts by mass, more preferably not more than 10 parts by mass. per 100 parts by weight silica. If the content of the silane coupling agent is not more than 15 parts by weight, in particular not more than 10 parts by weight, per 100 parts by weight silicon dioxide, there is a tendency that the processability of the rubber composition for the crimp part of the present invention will be excellent and, at the same time, the cost can be reduced.

Other rubber components for crimp

Various materials, such as oil, wax, antioxidant, stearic acid, zinc oxide, sulfur and a vulcanization accelerator, which are mainly used in the tire industry, can be appropriately included in the rubber composition for the crimp part of the present invention, in addition to the above materials. In addition, if these components are included, then the same components can be used as in the rubber composition for the tire.

A method of manufacturing a rubber composition for crimp

The rubber composition for the crimp portion of the present invention can be obtained by mixing the above materials by mixing them using a conventionally known open type mixer, Banbury mixer, pressure mixer or continuous mixer.

Crimp part made using rubber compound for crimp part

The crimp portion can be formed by extruding the rubber composition of the crimp portion of the present invention in an unvulcanized state.

Tire made using crimp made using rubber compound for crimp

A tire can be obtained by making a crude tire by installing a crimp made as described above and other tire elements at predetermined positions, followed by vulcanization of the rubber compound constituting the raw tire elements.

On Fig presents a schematic cross-sectional view of the upper left half of one example of a tire made as described above. Here, the tire 81 is characterized in that the crimp portion 64 is formed using a rubber composition for the crimp portion of the present invention. The remaining explanations are similar to the foregoing.

Since the tire 81 has the above construction so that the crimp portion 64 is formed using the rubber composition for the crimp portion of the present invention, the crimp portion 64 may have high abrasion resistance and high strength, whereby the abrasive wear of the rim and bead wire of the tire 81 may to be lowered.

The tire 81 shown in FIG. 8 is a tire for passenger cars, but the present invention is not limited to this tire and can be used, for example, for passenger cars, trucks, buses and heavy trucks.

In addition, since the amount of material used from oil sources is reduced in a tire 81 with the above structure, the tire can be considered environmentally friendly, taking into account the environment, and one can also be prepared to reduce oil reserves in the future.

In addition, from the point of view of reducing the amount of component obtained from oil sources, it is obvious that it is preferable to manufacture the tire using as many components as possible obtained from non-oil sources in other elements of the tire, in addition to the crimp portion 64.

BShL rubber compound

The above rubber composition for a tire of the present invention can be used, for example, as a rubber composition for a BCL. The rubber composition for BSL of the present invention contains at least 40 parts by weight silicon dioxide and not less than 0.5 wt.h. and not more than 10 parts by weight calcium stearate per 100 parts by weight of rubber component.

As a result of in-depth studies, the applicants determined that the use of a rubber compound having a composition comprising a rubber component containing at least one of such rubbers as natural rubber and epoxidized natural rubber, and at the same time included at least 40 parts by weight . silicon dioxide and not less than 0.5 wt.h. and not more than 10 parts by weight calcium stearate per 100 parts by weight the rubber component not only reduces the amount of material used from oil sources, but also improves the strength of rubber after heat aging and the adhesive properties between rubber and cord. Applicants believe that if this rubber composition is used for the manufacture of BSL, the properties of BSL may be excellent as a result of the implementation of the present invention.

Here, in the rubber composition for the BSL of the present invention, rubber, such as natural rubber and epoxidized natural rubber, or a mixture of rubbers obtained by mixing natural rubber and epoxidized natural rubber, is used as the rubber component. As described above, by using at least one of rubbers such as natural rubber and epoxidized natural rubber as the rubber component, the amount of material used from petroleum sources can be reduced.

It should be noted that the rubber component in the BSL rubber composition of the present invention may contain a rubber other than natural rubber and epoxidized natural rubber, and the content of such rubber is preferably not more than 20 wt.%, More preferably not more than 10 wt.% even more preferably not more than 5 wt.%, most preferably 0 wt.%, relative to the total weight of the rubber component.

In addition, if both natural rubber and epoxidized natural rubber are used in the BSH rubber composition of the present invention, the epoxy groups of the epoxidized natural rubber are preferably at least 5 wt.%, More preferably at least 10 wt.%, Relative to the total mass of the rubber component. If the content of the epoxy groups of the epoxidized natural rubber is at least 5 wt.%, In particular less than 10 wt.%, Relative to the total weight of the rubber component, there is a tendency that the strength of the rubber after vulcanization of the rubber composition for BSL of the present invention will increase in that order.

In addition, if rubber containing both natural rubber and epoxidized natural rubber in the BSH rubber composition of the present invention is used, the content of the epoxy groups of the epoxidized natural rubber is preferably not more than 65 wt.%, More preferably not less than 60 wt.% , even more preferably, at least 50 wt.%, relative to the total weight of the rubber component. If the content of the epoxy groups of the epoxidized natural rubber is not more than 65 wt.%, In particular not more than 60 wt.%, Moreover, not more than 50 wt.%, Relative to the total mass of the rubber component, there is a tendency that the tire heats up during the movement of the car decreases in this order, in a tire containing a BSL formed from a rubber composition for a BSL of the present invention.

In addition, in the rubber composition for the BSL of the present invention, as natural rubber and epoxidized natural rubber, natural rubber and epoxidized natural rubber can be used the same as in the rubber composition for the tire.

Silicon dioxide in a rubber compound for BShL

The rubber composition for BSL of the present invention contains at least 40 parts by weight silica per 100 parts by weight rubber component. By adopting such a composition, since the amount of soot used as a filler can be reduced, the amount of component used obtained from oil sources can be reduced. As the silica, the same silica can be used as in the rubber composition for the tire.

Here, the BET specific surface area of the silica is preferably not less than 80 m ² / g, more preferably not less than 100 m ² / g. If the BET specific surface area of silicon dioxide is at least 80 m ² / g, in particular at least 100 m ² / g, there is a tendency that the strength of the rubber after vulcanization of the BSL rubber composition of the present invention will increase.

Furthermore, the BET specific surface area of the silica is preferably not more than 230 m ² / g, more preferably not more than 210 m ² / g. If the BET specific surface area of silicon dioxide is not more than 230 m ² / g, in particular not more than 210 m ² / g, there is a tendency that the dispersibility (processability) of silicon dioxide in the rubber composition for BSL of the present invention will improve.

In addition, the specific surface area of silicon dioxide by BET can be measured by the method in accordance with ASTM-D-4820-93.

Calcium Stearate in BShL Rubber Compound

In the rubber composition for BSL according to the present invention contains at least 0.5 wt.h. and not more than 10 parts by weight calcium stearate per 100 parts by weight rubber component. Here, the content of calcium stearate is preferably not less than 1 part by mass, more preferably not less than 5 parts by mass, per 100 parts by mass. rubber component. As calcium stearate, the same calcium stearate can be used as in the rubber composition for a tire.

In the rubber composition for BSL of the present invention, taking a composition containing a rubber component comprising at least one of rubbers such as natural rubber and epoxidized natural rubber, and at least 40 parts by weight silica per 100 parts by weight rubber component and not less than 0.5 wt.h. and not more than 10 parts by weight, preferably not less than 1 part by weight and not more than 10 parts by weight, more preferably not less than 5 parts by weight and not more than 10 parts by weight calcium stearate, per 100 parts by weight of this rubber component, it is possible to suppress the decrease in strength due to thermal aging after vulcanization of the BSH rubber composition of the present invention, and at the same time, the adhesion properties between the rubber after vulcanization and the cord are improved.

BSL

The BSL is located annularly along the longitudinal direction of the annular carcass on an annular belt, located along the longitudinal direction of the carcass, on the outer longitudinal surface of the carcass and keeps the belt from slipping off the carcass under the action of the centrifugal force of the tire during vehicle movement. Preferably, the BSL is located along the longitudinal direction of the frame, but, for example, it can be inclined at an angle in the range of not less than 0 ° and not more than 10 ° relative to the longitudinal direction of the frame.

In addition, the BSL design can be, for example, a structure in which the cord is pressed into the rubber, but the BSL is exposed to heat that occurs in the tire during the movement of the vehicle and heat aging occurs and the strength of the BSL rubber decreases, so that it is not possible to sufficiently press the belt belt and the function of preventing the belt from slipping off the frame when the vehicle is moving is weakened. In addition, if the adhesion properties between the rubber constituting the BSL and the cord pressed into the rubber deteriorate, the pressing of the belt is insufficient, and the function of preventing the belt from slipping off the carcass when the vehicle is moving is suppressed.

Thus, it is believed that if the BSL is formed using the BSL rubber composition of the present invention, which can suppress the decrease in rubber strength due to heat aging after vulcanization and, at the same time, can improve the adhesion properties between the rubber after vulcanization and the cord, then a tire made using a BSL can be sufficiently suppressed by the slipping of the belt when the vehicle is moving. Therefore, the rubber composition for BSL of the present invention is preferably used to form BSL. Moreover, if the BSL is formed using the rubber composition for the BSL of the present invention, the amount of the used component obtained from oil sources can also be reduced compared to the previous BSL formed using a component obtained from oil sources, such as synthetic rubber and soot.

Soot in a rubber compound for BShL

In addition, previously known carbon black obtained from oil sources may be included in the rubber composition for BSL of the present invention. However, from the point of view of reducing the amount of material used from petroleum sources, the carbon black content is preferably not more than 25 parts by mass, more preferably not more than 5 parts by mass, per 100 parts by mass. rubber component, most preferably the absence of soot. It should be noted that if soot is included, the same soot can be used as soot as in the rubber composition for the tire.

Other rubber components for BShL

Various materials, such as oil, wax, antioxidant, stearic acid, zinc oxide, sulfur and a vulcanization accelerator, which are mainly used in the tire industry, can be appropriately included in the rubber composition for BSL of the present invention, in addition to the above materials. If these components are included, then the same components can be used as in the rubber composition for the tire.

A method of manufacturing a rubber compound for BShL

The BSL rubber composition of the present invention can be obtained, for example, by mixing a rubber component containing at least one of rubbers such as natural rubber and epoxidized natural rubber, silicon dioxide and calcium stearate. Here it is obvious that, if necessary, previously known additives may be included.

In addition, previously known mixing methods can be used as the mixing method used in the manufacture of the BSL rubber composition of the present invention, and examples include a method for mixing components using a well-known open type mixer, a Banbury mixer, a pressure mixer or a mixer continuous action.

BShL made using rubber compound for BShL

Fig. 9 is a schematic view of one example of a BSL made using the rubber composition for BSL of the present invention.

Here, the BSL 91 has a structure in which three cords 93 are pressed into the cubic rubber composition 92 for the BSL of the present invention, and the three cords 93 are spaced parallel to each other. In addition, as cord 93, for example, nylon cord or rayon cord can be used, but from the point of view of reducing the amount of component used from oil sources, and from the point of view of improving the adhesion properties with respect to vulcanized rubber obtained by vulcanizing the rubber composition according to the present invention, preferably the use of viscose cord. In addition, it is apparent that the BSL made using the BSL rubber composition of the present invention is not limited to the design shown in FIG. 9 while the cord is pressed into the BSL rubber composition of the present invention.

A tire made using BShL made using a rubber compound for BShL

One example of tire manufacturing using the BSL 91 shown in FIG. 9 is described below. First, for example, a carcass with a structure in which a cord made of polyester fiber is pressed into a rubber sheet is wound around the outer longitudinal surface of a previously known rotating drum in an annular fashion.

Then, the bead wire obtained by twisting into a ring of a bundle of many wires is driven along the outer longitudinal surface from both ends of the annular frame and, at the same time, the bead filler is inserted, and both ends of the bead are folded inward to wrap the bead wire and bead filler with the frame .

Further, as shown in FIG. 10 in a schematic cross-sectional view, the frame 94, at the ends of which the bead wire 95 and the bead filler 97 are wrapped, are inflated in the shape of a toroid, and the belt 96 is ring-shaped to receive it by successive layering of the first layer 96b of the belt and a second layer 96a of the belt of the belt on the outer longitudinal surface in the center of the frame 94.

Here, the first belt belt layer 96b and the second belt zone layer 96a that make up the belt 96, respectively, have a structure in which a cord, such as steel cord, is embedded in a cubic rubber composition for the belt.

Then, as shown in FIG. 11 in a schematic cross-sectional view, the BSL 91 with the structure shown in FIG. 9 is wound ring-wise along the longitudinal direction of the chassis 94 so as to cover the end of the belt 96 along the outer longitudinal surface of the chassis 94.

12 is an enlarged schematic view showing the relative position of the BSL 91 and the belt belt 96 after winding the BSL 91 shown in FIG. 11. Here, as shown in FIG. 12, two BSLs 91 are located, respectively, so that part of them covers the end of the outer longitudinal surface of the belt of the belt 96, and the remaining part protrudes on the outer longitudinal surface of the frame 94. In addition, two BSL 91 are located, respectively, so that part of them covers the end of the first layer 96b of the belt and the second layer 96a of the belt. The foreseen position of the BSL is generally not limited as long as at least a portion of the BSL is located on the outer longitudinal surface of the belt.

Then, in a previously known manner, a crude tire is made, the obtained crude tire is placed in a molding mold and, thereby, vulcanized rubber mixture comprising each of the parts such as the raw tire tread, sidewall, inner liner, belt belt, carcass, BSL and filler is vulcanized. beads, vulcanize, getting a tire.

In the foregoing, the description of the steps for preparing the tread, sidewall and inner liner is omitted.

On Fig presents a cross section of the upper part of one of the parts obtained, as described above, tires. In addition, FIG. 14 is a schematic view for illustrating the internal structure of another example of a tire obtained as described above.

Here, in the tires of FIG. 13 and FIG. 14. a sidewall 99 is formed on the side of the carcass 94, into which the bead wire 95 and the bead filler 97 are wrapped at both ends thereof. In addition, in the center of the outer longitudinal surface of the frame 94, there is a belt belt 96, and at the same time, the BSL 91 is located so as to cover the end of the belt belt 96; a tread 98, which is the contact area with the tire ground, is formed on the outer longitudinal side of the belt 96 and the BSL 91. In addition, an inner gasket 910 is located on the inner longitudinal surface of the carcass 94 to suppress leakage of gas, such as air, from the inner region of the carcass 94.

Since the tire with the above construction uses a BSL made using the rubber mixture for the BSL of the present invention, it is possible not only to reduce the amount of material used from oil sources and suppress the decrease in rubber strength due to thermal aging of the BSL, but also the adhesion properties between the BSL rubber and the cord can be improved, as a result of which the slipping of the belt when the vehicle is moving can be substantially suppressed.

From the point of view of reducing the number of components obtained from oil sources, it is preferable to manufacture other elements of the tire, in addition to BSL, using as many components as possible obtained from non-oil sources.

Rubber compound for a board filler

The rubber composition for a tire of the present invention can be used, for example, as a rubber composition for a bead apex. The rubber composition for a bead apex according to the present invention has a composition containing at least 60 parts by weight silicon dioxide, and at least 2 parts by weight and not more than 10 parts by weight calcium stearate per 100 parts by weight rubber component.

As a result of in-depth studies, the applicants determined that the use of a rubber composition having a composition comprising a rubber component containing at least one of such rubbers as natural rubber and epoxidized natural rubber, and at the same time included per 100 parts by weight. the rubber component is not less than 60 parts by weight silicon dioxide and not less than 2 parts by weight and not more than 10 parts by weight Calcium stearate, not only reduces the amount of material used from oil sources, but also improves molding processability and can increase thermal aging resistance and rubber hardness after vulcanization. Applicants believe that if this rubber composition is used to make a bead apex, the bead apex properties will be excellent as a result of the implementation of the bead apex rubber composition of the present invention.

Here, in the rubber composition for the bead apex of the present invention, rubber such as natural rubber and epoxidized natural rubber, or a mixture of rubbers obtained by mixing natural rubber and epoxidized natural rubber, is used as the rubber component. By using a rubber component containing at least one of rubbers such as natural rubber and epoxidized natural rubber as the rubber component as described above, the use of the component obtained from petroleum sources can be reduced.

In addition, the rubber component of the rubber composition for the bead apex of the present invention may contain other rubber than natural rubber and epoxidized natural rubber, and its content is preferably not more than 20 wt.%, More preferably not more than 10 wt.%, Still more preferably not more than 5 wt.%, most preferably 0 wt.%, relative to the total weight of the rubber component.

In addition, if a rubber mixture obtained by mixing natural rubber and epoxidized natural rubber is used as the rubber component for the bead filler of the present invention, the epoxy content of the epoxidized natural rubber is preferably not more than 65 wt.%, More preferably not more than 60 wt. %, even more preferably, not more than 50 wt.%, relative to the total weight of the rubber component. If the content of the epoxy groups of the epoxidized natural rubber is not more than 65 wt.%, And in particular not more than 60 wt.%, Especially not more than 50 wt.%, Relative to the total mass of the rubber component, there is a tendency that tire heating during vehicle movement is reduced in this order, in a tire containing a bead apex formed from a rubber composition for a bead apex according to the present invention.

In addition, in a rubber composition for a bead apex according to the present invention, the same rubbers as in a rubber composition for a tire can be used as natural rubber and epoxidized natural, respectively.

Silicon dioxide in a rubber compound for a bead apex

In the rubber composition for a bead apex according to the present invention contains at least 60 parts by weight silica per 100 parts by weight rubber component. By adopting such a composition, since the amount of soot used as filler can be reduced, the amount of component used from petroleum sources can be reduced. It should be noted that silicon dioxide can be used the same silicon dioxide as in the rubber composition for tires.

Here, the BET specific surface area of the silica is preferably not less than 80 m ² / g, more preferably not less than 100 m ² / g. If the BET specific surface area of silicon dioxide is not less than 80 m ² / g, in particular not less than 100 m ² / g, there is a tendency that the rubber strength increases after vulcanization of the rubber composition for the bead apex of the present invention.

Furthermore, the BET specific surface area of the silica is preferably not more than 230 m ² / g, more preferably not more than 210 m ² / g. If the BET specific surface area of silicon dioxide is not more than 230 m ² / g, in particular not more than 210 m ² / g, there is a tendency that the dispersibility (processability) of silicon dioxide in the rubber composition for the bead apex of the present invention will become better.

In addition, the BET specific surface area of silicon dioxide can be measured by the method in accordance with ASTM-D-4820-93.

Calcium stearate in a rubber compound for a bead apex

In the rubber composition for a bead apex according to the present invention contains at least 2 parts by weight and not more than 10 parts by weight calcium stearate per 100 parts by weight rubber component. In addition, the same calcium stearate can be used as the calcium stearate as in the rubber composition for the tire.

With respect to the rubber composition for the bead apex according to the present invention, taking a composition comprising a rubber component containing at least one of rubbers such as natural rubber and epoxidized natural rubber, and per 100 parts by weight the rubber component is not less than 50 parts by weight silicon dioxide and not less than 2 parts by weight and not more than 10 parts by weight calcium stearate receive excellent molding processability and resistance to thermal aging, and the rubber hardness after vulcanization can be increased, as shown.

In addition, if the content of calcium stearate is at least 5 parts by weight and not more than 10 parts by weight per 100 parts by weight rubber component, there is a tendency that the molding processability will further improve.

Side filler

The bead filler enhances the rigidity of the bead wire, improving the stability of the tire when at least a part is located between the straight part and the bent part of the annular carcass, which is bent so that it surrounds the bead wire located on the outer longitudinal surface of the carcass at the end in a direction perpendicular to the longitudinal direction frame. Therefore, it is necessary that the bead filler possess high resistance to thermal aging in order to suppress the deterioration of strength due to heating when the vehicle is moving and it is necessary that it has high hardness in order to increase the rigidity of the bead wire. In addition, the bead filler may be positioned so that a portion thereof protrudes from the area between the straight portion and the bent portion of the frame bend.

In addition, the bead apex is located between the straight part and the bend of the carcass, which is bent at the stage of forming the unvulcanized rubber mixture into a predetermined shape, and if changes occur in the formed form, changes also occur in the properties of the bead apex after vulcanization. Therefore, it is necessary to use such an unvulcanized rubber composition to form a bead filler, which has excellent processability in molding.

Then, if the bead apex is made using the rubber composition of the present invention, which can increase the thermal resistance and hardness of the rubber after vulcanization and, at the same time, improve the molding processability, it is obvious that in a tire made using a bead apex, stability tire operation during long-term vehicle movement can be stably improved. Therefore, the rubber composition of the present invention is preferably used for the qualitative formation of the bead apex. In addition, if the bead apex is formed using the rubber composition of the present invention, the amount of component used obtained from petroleum sources can be reduced compared to the previous bead apex using a component obtained from petroleum sources, such as synthetic rubber and soot.

Soot in a rubber compound for a board filler

In addition, the rubber composition for a bead apex according to the present invention may contain previously known carbon black obtained from petroleum sources. However, in terms of reducing the amount of material used from petroleum sources, the carbon black content is preferably not more than 25 parts by mass, more preferably not more than 5 parts by mass. per 100 parts by weight rubber component. In addition, the same carbon black can be used as soot as in the rubber composition for a tire.

Other components of the rubber composition for the bead filler

In addition to the above materials, various materials such as oil, wax, antioxidant, stearic acid, zinc oxide, sulfur and a vulcanization accelerator, which are mainly used in the tire industry, can accordingly be included in the rubber composition for the bead apex of the present invention. If these components are included, then the same components can be used as in the rubber composition for the tire.

A method of manufacturing a rubber composition for a bead apex

The rubber composition for a bead apex according to the present invention can be obtained, for example, by mixing a rubber component containing at least one of rubbers such as natural rubber and epoxidized natural rubber with silicon dioxide and calcium stearate. It is obvious here that, if necessary, previously known additives can be included.

In addition, previously known mixing methods can be used as the mixing method used in preparing the rubber composition for the bead apex of the present invention, and examples include a method for mixing components using a well-known open type mixer, a Banbury mixer, a pressure mixer, or continuous mixer.

Bead filler made using a rubber compound for bead filler

The bead apex can be formed by extruding the rubber composition for the bead apex of the present invention in an unvulcanized state.

A tire made using a bead apex made using a rubber composition for a bead apex

One example of a method for manufacturing a tire using a bead apex made using the rubber composition for a bead apex of the present invention is described below.

First, a carcass with a structure in which the cord is made, for example, of polyester fiber pressed into a rubber sheet, is ring-wound onto the outer longitudinal surface of a previously known rotating drum.

Then, as shown in a schematic cross-sectional view of Fig. 15, the bead wire 155 obtained by twisting into a ring of a bundle of multiple wires is driven along the outer longitudinal surface from both ends of the annular frame 154, and at the same time, a bead filler 157 consisting of the rubber composition for the bead filler of the present invention, both ends of the carcass 154 are folded inward to wrap the bead wire 155 and the bead filler 157 between the bent portion 154a and the straight portion 154b of the carcass 154.

Then, as shown in a schematic cross-sectional view of FIG. 16, the frame 154, the ends of which are wrapped by the bead wire 155 and the bead filler 157, is pumped into a toroid.

The raw tire is then made in a previously known manner, and the prepared raw tire is placed in a tire mold and the unvulcanized rubber composition constituting each part of the tire, such as tread, sidewall, belt, BSL, inner liner, carcass and bead, is vulcanized. unvulcanized tires, thereby obtaining a tire.

In the foregoing, the description of the stages of placement of the tread, sidewall and inner liner is omitted.

On Fig in a schematic cross-sectional view shows the upper part of one of the examples made, as indicated above, of the tire. On Fig in an enlarged schematic cross-sectional view shows the area of the tire bead filler shown in Fig.17.

Here, as shown in FIG. 17, in the tire manufactured as described above, the sidewall 159 is formed on the side of the carcass 154 wrapping the bead wire 155 and the bead filler 157 at both ends thereof. In addition, in the center of the outer longitudinal surface of the carcass 154, there is a belt 156 obtained by layering the first layer 156b of the belt and the second layer 156a of the belt in this order, and at the same time, the BSL 151 is positioned to cover the end of the belt 156; and a tread 158, which is the area of contact with the tire ground, is formed on the outer longitudinal side of the belt 156 and BSL 151. In addition, an inner gasket 1510 is disposed on the inner longitudinal surface of the chassis 154 to suppress leakage of gas, such as air, from the chassis 154.

In addition, in FIG. 18, a portion of the bead filler 157 is located between the folded portion 154a and the straight portion 154b of the chassis 154, and is shaped so that the thickness of the bead filler 157 decreases as it extends toward the outside of the tire diameter.

Since the tire with the above construction is made using a bead apex made using a rubber composition for a bead apex according to the present invention, which can not only reduce the amount used from a material obtained from oil sources, but also improve the manufacturability of molding a rubber compound in an unvulcanized state as well as improve the resistance to thermal aging and the hardness of the bead filler after vulcanization, the stability of the tire during prolonged testing His car can be steadily improved.

In addition, from the point of view of reducing the amount of component used, obtained from oil sources, it is preferable to manufacture other tire elements, in addition to the bead filler, using as many components as possible obtained from non-oil sources.

Experimental Example 1

Preparation of unvulcanized rubber compound

First, in accordance with the composition shown in Table 1, materials, with the exception of sulfur and a vulcanization accelerator, were fed into a closed type mixer and mixed at a temperature of 150 ° С for 3 min. Then, sulfur and a vulcanization accelerator were added to the resulting mixture and stirred at 90 ° C for 3 min to obtain each of samples 1-5 of uncured rubber compounds.

The numerical values presented in the “Other Components” section of Table 1 show the amount of each component, expressed in parts by weight, assuming that the amount of the rubber component is 100 parts by weight.

Frame manufacturing

Each of samples 1-5 of unvulcanized rubber compounds made as described above was processed into a thin film 1 mm thick or less using a calender roll, then the frame cord was coated with unvulcanized rubber mixture processed into a film, and frame samples 1-5 were made of samples 1-5 unvulcanized rubber compound, respectively.

In addition, samples 1-5 of the frame differed only in the composition of the unvulcanized rubber composition. In addition, since with increasing Mooney viscosity of the unvulcanized rubber composition, in some cases, the heating of the unvulcanized rubber composition during processing becomes large, the linear speed was accordingly adjusted to suppress the increase in Mooney viscosity.

Rolling Resistance Measurement

Using each of the 1-5 carcass samples manufactured as described above, 1-5 tire samples were manufactured for a passenger car, size 195 / 65R15. Samples of 1-5 tires for a passenger car differ from each other only in frame.

Here, the main design of the manufactured tire for a passenger car was as follows.

Frame

Cord angle - 90 degrees in the longitudinal direction of the tire

Cord material - viscose fiber 1840 dtex / 2

Belt

Cord angle - 24 degrees × 26 degrees in the longitudinal direction of the tire

Cord material - steel (brass coating (copper-zinc alloy coating))

BSL

Cord angle - 0 degrees in the longitudinal direction of the tire

Cord material - steel cord 3 × 3 × 0.17

Each of samples 1-5 of a passenger car tire manufactured as described above was mounted on a standard rim (6JJ × 15), and rolling resistance was measured under conditions of internal pressure of 230 kPa, speed of 80 km / h and a load of 49 N, using a stand rolling resistance tests manufactured by STL.

Then, for each of samples 1-5 of the tire for a passenger car, the coefficient of rolling resistance (KSK) was calculated by dividing the measured value of rolling resistance by load, and taking the coefficient of rolling resistance (KSK) of sample 3 of the tire for a passenger car for 100, relative quantities. The results are presented in table 1. Higher numerical values in the column “Rolling Resistance” of Table 1 show that the rolling resistance is less and the tire performance is better.

Rubber strength

Each of samples 1-5 of the uncured rubber composition was vulcanized at a temperature of 170 ° C. for 10 minutes to obtain each of samples 1-5 of the vulcanized rubber sheet.

For vulcanized rubber sheets obtained as described above, tensile tests were performed using a dumbbell-shaped test specimen No. 3 in accordance with JIS K6251, and tensile strength (PR) and elongation at break (UR) were obtained. As an indicator of the rubber strength of each of samples 1-5 of the vulcanized rubber sheet, the product of tensile strength (PR) and elongation at break (UR) were calculated. The results are presented in table 1.

In the column “Rubber Strength” of Table 1, higher numerical values indicate that the rubber strength is better. In addition, when calculating the product of tensile strength (PR) and elongation at break (UR), the units of measurement of tensile strength (PR) are expressed in MPa, and the units of measurement of elongation at break (UR) are expressed in%.

Rating

As shown in table 1, if each sample 1 and 2 of an unvulcanized rubber composition containing calcium stearate of at least 1 part by weight is used. and not more than 10 parts by weight per 100 parts by weight natural rubber (NR), even if a large amount of silicon dioxide is included as a filler, namely 60 wt.h. per 100 parts by weight natural rubber (NR), the rolling resistance of a passenger car tire is reduced and, at the same time, the strength of the rubber after vulcanization is superior to that of the unvulcanized rubber compound of each of samples 3 and 4 that do not contain calcium stearate, and sample 5 that contains calcium stearate in the amount of 15 parts by weight per 100 parts by weight natural rubber (NK), therefore, it can be assumed that the durability of the tire will also be excellent.

Experimental Example 2

Preparation of unvulcanized rubber compound

First, in accordance with the composition shown in Table 2, materials, with the exception of sulfur and a vulcanization accelerator, were fed into a closed-type mixer, and the mixture was stirred at a temperature of 150 ° C for 3 min. Then sulfur and a vulcanization accelerator were added to the resulting mixture and stirred at a temperature of 90 ° C for 3 min to obtain each of the samples 6-10 unvulcanized rubber compounds.

In addition, the numerical values presented in the column of the other components of Table 2 show the amount of each component, expressed in parts by weight, if we assume that the amount of the rubber component is 100 parts by weight.

Making the base of the tread

Each of samples 6-7 of uncured rubber compounds made as described above was processed into a thin film of 2 mm or less thickness using a calender shaft to make each of samples 6-10 of the tread base. Each of samples 6-10 of the tread base differed only in unvulcanized rubber compound.

Rolling Resistance Measurement

Using each of samples 6-10 of the tread base made as described above, each of samples 6-10 of a tire for a passenger car of size 195 / 65R15 was made. Samples of 6-10 tires for a passenger car, all elements, such as a treadmill, etc., were the same, except for the tread base.

Here, the main design of the manufactured tire for a passenger car was as follows.

Frame

Cord angle - 90 degrees in the longitudinal direction of the tire

Cord material - viscose fiber 1840 dtex / 2

Belt

Cord angle - 24 degrees × 26 degrees in the longitudinal direction of the tire

Cord material - steel (brass coating (copper-zinc alloy coating))

BSL

Cord angle - 0 degrees in the longitudinal direction of the tire

Cord material - steel cord 3 × 3 × 0.17

Each of the samples of 6-10 tires for a passenger car made as described above was mounted on a standard rim (6JJ × 15), and rolling resistance was measured under conditions of an internal pressure of 230 kPa, a speed of 80 km / h, and a load of 49 N using a stand for rolling resistance tests manufactured by STL.

Then, for each of the samples of 6-10 tires for a passenger car, the rolling resistance coefficient (KCK) was calculated by dividing the measured value of rolling resistance by load, and, taking the rolling resistance coefficient (KSK) of sample 8 of the tire for a passenger car for 100, relative values . The results are presented in table.2. Higher numerical values in the column “Rolling resistance” of Table 2 show that the rolling resistance is less and the tire performance is better.

Each of samples 6-10 of the uncured rubber composition was vulcanized at a temperature of 170 ° C for 10 minutes to obtain each of samples 6-10 of the vulcanized rubber sheet.

In relation to the vulcanized rubber sheet obtained as described above, tensile tests were performed using a dumbbell-shaped test specimen No. 3, in accordance with JiS K6251, and tensile strength (PR) and elongation at break (UR) were obtained. The product of tensile strength (PR) and elongation at break (UR) were calculated as an indicator of the rubber strength of each of samples 6-10 of the vulcanized rubber sheet. The results are presented in table.2.

In the column “Rubber Strength” of Table 2, higher numerical values show that the rubber strength is better. In addition, when calculating the product of tensile strength (PR) and elongation at break (UR), the units of measurement of tensile strength (PR) were expressed in MPa, and the units of measurement of elongation at break (UR) were expressed in%.

Rating

As shown in table 2, if you use unvulcanized rubber mixture of each sample 6 and 7, containing calcium stearate of at least 1 wt.h. and not more than 10 parts by weight per 100 parts by weight natural rubber (NR), even if a large amount of silicon dioxide is included as a filler, namely 50 wt.h. per 100 parts by weight natural rubber (NR), the rolling resistance of a passenger car’s tire is reduced and, at the same time, the strength of the rubber after vulcanization is excellent compared to the use of unvulcanized rubber mixture of each of samples 8 and 9, not containing calcium stearate, and sample 10, containing calcium stearate in the amount of 15 parts by weight per 100 parts by weight natural rubber (NK), therefore, it can be assumed that the durability of the tire will also be excellent.

Experimental Example 3

In accordance with the composition shown in Table 3, the components, with the exception of sulfur and a vulcanization accelerator, were mixed at a temperature of 150 ° C for 6 min using a Banbury mixer to obtain a mixture. Then sulfur and a vulcanization accelerator were added to the resulting mixture, and the mixture was stirred at 80 ° C. for 3 minutes to obtain each of 11-13 unvulcanized rubber mixtures.

In addition, the numerical values presented in the column “Other components” of Table 3 show the amount of each component, expressed in parts by weight, if we assume that the total amount of the rubber component is 100 parts by weight.

Manufacturability of extrusion

Each of samples 11-13 of uncured rubber compounds made as described above was extruded using a laboratory extruder to produce a rubber sheet. The shape quality of the obtained rubber sheets was evaluated visually. The results are presented in table.3.

In addition, the extrusion processability is expressed as a relative value, taking the state of the edge of the rubber sheet of sample 13 as 100. In the extrusion processability column of Table 3, the best edge condition shows a higher numerical value.

Durability of rubber after thermal aging

Each of samples 11-13 of the unvulcanized rubber composition obtained as described above was vulcanized at a temperature of 150 ° C for 30 minutes to obtain each of the samples 11-13 of the vulcanized rubber sheet.

Then, samples 11-13 of vulcanized rubber sheets obtained as described above were subjected to thermal aging at 100 ° C and 48 hours, dumbbell-shaped test samples No. 3 were made from samples 11-13 of vulcanized rubber sheets, and used for tensile testing in in accordance with JIS K6251 "Vulcanized Rubber and Thermoplastics - How to Obtain Tensile Strength Properties", and measured tensile strength (PR) and elongation at break (UR) of the tested samples, and calculated the rate of strength after heat Vågå aging Tire according to equation (1), thereby evaluating the rubber strength after thermal aging. The results are presented in table.3. A higher numerical value in the column “Strength index after thermal aging of rubber” of Table 3 shows that the strength of rubber after thermal aging is higher.

Rating

As can be seen from the results presented in table 3, unvulcanized rubber mixture of each sample 11 and 12, containing 40 wt.h. silica, 5 parts by weight and 10 parts by weight calcium stearate, respectively, per 100 wt.h. the rubber component, shows a better processability of extrusion in an unvulcanized state compared to the unvulcanized rubber composition of sample 13 that does not contain calcium stearate, leading to suppression of the decrease in rubber strength due to thermal aging after vulcanization.

Of the above results, the unvulcanized rubber mixture of samples 11 and 12 has high processability in the unvulcanized state and can also suppress the decrease in rubber strength due to thermal aging after vulcanization. Therefore, the unvulcanized rubber composition of samples 11 and 12 is preferably used to form the tire sidewall, and if the sidewall of the tire is formed using this unvulcanized rubber composition, it can be assumed that the tire longevity can be extended and, at the same time, the stability of the vehicle is improved.

In addition, since the unvulcanized rubber mixture of samples 11 and 12 is such that the amount of carbon black is noticeably lower than the previously used amount, the amount of component used from oil sources can also be reduced.

Experimental Example 4

Production of unvulcanized rubber compound

According to the composition shown in Table 4, the components, with the exception of sulfur and a vulcanization accelerator, were mixed at a temperature of 150 ° C for 6 min using a Banbury mixer to obtain a mixture. Then, sulfur and a vulcanization accelerator were added to the resulting mixture, and the mixture was stirred at 80 ° C. for 5 minutes using an open type mixer to obtain samples 14-19 of unvulcanized rubber compounds. The numerical values presented in the column “Other components” of Table 4 show the amount of each component, expressed in parts by weight, if we assume that the amount of the rubber component is 100 parts by weight.

Manufacturability of extrusion

Each of samples 14-19 of uncured rubber compounds made as described above was extruded using a laboratory extruder to produce a rubber sheet. Then, the mold quality of the obtained rubber sheets was evaluated visually. The results are presented in table 4.

In the column “Extrusion processability” of Table 4, samples on which there are no chipped edges and no processing problems are indicated by A, and samples on which there are chipped edges and there are problems during processing are indicated by B.

Resistance to intense abrasion

Each of samples 14-19 of the uncured rubber composition obtained as described above was vulcanized at a temperature of 150 ° C. for 30 minutes to obtain each of the samples 14-19 of vulcanized rubber sheets.

Then, in accordance with JIS K6251 "Vulcanized Rubber and Thermoplastic - How to Obtain Abrasion Resistance", samples of 14-19 vulcanized rubber sheets obtained as described above were subjected to wear on a picoabrasion wear test apparatus manufactured by Ueshima Seisakusho Co., Ltd ., the change in mass of each test piece of vulcanized rubber before and after the test was measured, and the pico-abrasion index was calculated according to equation (2), thus, the resistance to intense abrasion was determined. The results are presented in table 4. A larger numerical value in the column for intensive abrasion resistance of Table 4 shows that the resistance to intense abrasive wear is higher.

Rubber strength

From samples 14-19 of vulcanized rubber sheets obtained as described above, a dumbbell-like test piece No. 3 was made, tensile tests were performed in accordance with JIS K6251 "Vulcanized Rubber and Thermoplastics - How to Obtain Tensile Strength Properties", and strength was measured tensile strength (PR) and elongation at break (UR) of the tested samples, and the rubber strength index was calculated according to the following equation (3), thus, the rubber strength was evaluated. The results are presented in table 4. The largest numerical value in the graph of the rubber strength of Table 4 shows that the rubber strength is higher.

Rating

As can be seen from the results presented in table 4, unvulcanized rubber mixture of each sample 14-16, containing 60 wt.h. silicon dioxide and not less than 2 parts by weight and not more than 10 parts by weight calcium stearate per 100 parts by weight rubber component, has the best adaptability of extrusion, which leads to increased resistance to intensive abrasive wear and rubber strength after vulcanization.

On the other hand, since the unvulcanized rubber composition of sample 17 does not contain calcium stearate, the extrusion processability is low. Since the unvulcanized rubber composition of sample 18 contains calcium stearate, but the content is less than 0.5 parts by weight. relative to the rubber component, the extrusion processability is low.

Moreover, since the unvulcanized rubber composition of sample 19 contains calcium stearate 15 parts by weight, relative to the rubber component, there is a tendency to decrease the strength of the rubber.

Based on the above results, since unvulcanized rubber compounds of samples 14-16 have high processability during devulcanization and have high resistance to intense abrasive wear and high strength after vulcanization, they are preferably used to form the crimp part of the tire, and we can assume that they can reduce abrasion between the rim and the bead wire of the tire.

In addition, since unvulcanized rubber mixtures of samples 14-16 are such mixtures in which the amount of soot used is significantly reduced than the amount used previously, therefore, the amount of component used obtained from oil sources can also be reduced.

Experimental Example 5

Production of unvulcanized rubber compound

According to the composition shown in Table 5, the components, with the exception of sulfur and a vulcanization accelerator, were mixed at a temperature of 150 ° C for 6 min using a Banbury mixer to obtain a mixture. Then sulfur and a vulcanization accelerator were added to the resulting mixture using an open type mixer, the mixture was stirred at 80 ° C for 5 min and formed into a sheet, so that each of the unvulcanized sheets (2 mm thick) made from samples 20 was obtained -26 unvulcanized rubber compound. The numerical values presented in the column “Other components” of Table 5 show the amount of each component, expressed in parts by weight, if we assume that the amount of the rubber component of the mixture of NK and ENK is 100 parts by weight.

Thermal aging tests

Each of samples 20-26 of unvulcanized rubber sheets was vulcanized under a press at a temperature of 150 ° C for 30 minutes to obtain samples for thermal aging testing of each of samples 20-26.

Then, each test sample for thermal aging of samples 20-26 was kept at a temperature of 100 ° C for 48 h, tensile tests were performed in accordance with JIS K6251, elongation at break (UR) and tensile strength (PR) of each sample were measured for testing for thermal aging, the fracture strength (URhPR / 2) was calculated based on the measured values, and this fracture strength was taken as the strength of the rubber after the thermal aging test. The results are presented in table.5.

Here, in the column “Strength of rubber after the thermal aging test” of Table 5, the strength of rubber after the thermal aging test of each specimen for the thermal aging test of samples 20-26 was expressed in relative terms, taking the rubber strength (fracture strength) after the thermal test aging of vulcanized rubber sample 24 per 100.

Here, the greater numerical value of the rubber strength after the thermal aging test shows that a decrease in rubber strength due to thermal aging can be suppressed.

In addition, it goes without saying that when examining the samples for the thermal aging test of samples 20-26, the thermal aging tests were performed by the same method and under the same conditions.

Peel test

Each of the samples of 20-28 unvulcanized rubber sheets was applied to the upper and lower surfaces of viscose cords located at the same distance from each other, pressed and vulcanized under a press at a temperature of 150 ° C for 30 min to obtain samples for testing for peeling of each of the samples 20-26.

Then, a 25 mm wide incision was made on the surface of the specimen to test the peeling of samples 20–26, and they were peeled off on a tensile testing machine at a tensile speed of 50 mm / min.

Then, the fraction of the outer longitudinal surface of the viscose cord coated with rubber after peeling was calculated as the degree of coverage (%) after the peeling test (the degree of coverage of 100% indicates that the entire outer longitudinal surface of the viscose cord is coated with rubber). The results are presented in table.5.

Here, a greater value of the degree of coating (%) after the peeling test indicates that the adhesive properties with viscose cord are excellent.

It is obvious in relation to samples for testing for peeling from samples 20-26, that tests for peeling were performed by the same method and under the same conditions in all cases.

Test results

As can be seen from the results presented in table 5, the samples obtained by vulcanization of samples 20-23 unvulcanized rubber mixture, in which the carbon black content is reduced to 5 parts by weight, the content of silicon dioxide is 50 parts by weight and the content of calcium stearate is not less than 0.5 wt.h. and not more than 10 parts by weight per 100 parts by weight the rubber component of NK and ENK, show excellent characteristics both in terms of the strength of the rubber after the thermal aging test and the degree of surface coverage after the peeling test, as compared to the samples obtained by vulcanizing samples 24 and 25 of unvulcanized rubber mixture not containing calcium stearate , and a sample obtained by vulcanizing a sample 26 of an unvulcanized rubber composition containing 12 parts by weight calcium stearate.

Therefore, as can be seen from the above results, it can be assumed that if the BSL is made using samples of 20-23 unvulcanized rubber mixtures, a BSL is obtained that excellently suppresses the slipping of the belt when the car is moving, compared to the case when the BSL is made using samples 24 -26 unvulcanized rubber compound.

In addition, samples obtained by vulcanization of samples 20-22 of an unvulcanized rubber composition, in which the content of calcium stearate is not less than 1 wt.h. and not more than 10 parts by weight per 100 parts by weight rubber component, show excellent characteristics on the strength of the rubber after the test for thermal aging, compared with the sample obtained by vulcanization of sample 23 of the uncured rubber compound, in which the content of calcium stearate is 0.5 wt.h. per 100 parts by weight rubber component.

Therefore, it can be assumed that if the BSL is made using samples of 20-22 unvulcanized rubber compound, a BSL is obtained that excellently suppresses the slipping of the belt when the car is moving, compared to the case when the BSL is made using the unvulcanized rubber sample 23.

Moreover, the samples obtained by vulcanization of samples 21 and 22 of the unvulcanized rubber composition, in which the content of calcium stearate is at least 5 parts by weight and not more than 10 parts by weight per 100 parts by weight rubber component, show excellent characteristics on the strength of the rubber after the test for thermal aging, compared with the sample obtained by vulcanization of sample 20 of the uncured rubber composition, in which the content of calcium stearate is 1 wt.h. per 100 parts by weight rubber component.

Therefore, it can be assumed that if the BSL is made using samples 21-22 of an unvulcanized rubber compound, a BSL is obtained that excellently suppresses the slipping of the belt when the car is moving, compared to the case when the BSL is made using an unvulcanized rubber sample 20.

Experimental Example 6

Production of unvulcanized rubber compound

In accordance with the composition shown in Table 6, the components, with the exception of sulfur and a vulcanization accelerator, were mixed at a temperature of 150 ° C for 6 min using a Banbury mixer to obtain a mixture. Then sulfur and a vulcanization accelerator were added to the resulting mixture, and the mixture was stirred at a temperature. 80 ° C for 5 min using an open type mixer to obtain samples 27-33 of the uncured rubber compound. The numerical values presented in the column “Other components” of Table 6 show the amount of each component, expressed in parts by weight, if we assume that the amount of rubber component made from NK is 100 parts by weight.

Mooney Viscosity

For each of the samples 27-33 of the uncured rubber compound, the Mooney viscosity was measured according to JIS K6300. The result is presented in table.6.

The larger numerical value in the “Mooney viscosity” column in Table 6 shows that the Mooney viscosity is higher.

Manufacturability of extrusion

Extrusion molding of each of the samples 27-33 of the unvulcanized rubber mixture was carried out using a press extruder, and the condition of the edges of the molded products obtained by molding of the samples 27-33 of the unvulcanized rubber mixture after extrusion into the desired shape of the bead apex was evaluated visually. The results are presented in table.6.

In addition, the extrusion processability presented in Table 6 was evaluated using a five-point system, and the state in which the smallest number of edge defects was evaluated at 5 points, and the highest at 1 point. Therefore, the largest numerical value in the column “Extrusion processability” of Table 1 shows that the extrusion processability is excellent.

Hardness

Each of the unvulcanized rubber composition samples 27-33 was formed into sheets to obtain unvulcanized rubber sheets, and then each unvulcanized rubber sheet was press vulcanized at a temperature of 150 ° C for 30 minutes to obtain each of the 27-33 vulcanized rubber sheet .

Then, for each of the above samples of 27-33 vulcanized rubber sheets, the durometer hardness was measured in accordance with JIS K8253. The results are presented in table.6. The largest numerical value in the “Hardness” column of Table 1 shows that the hardness by durometer is higher.

Resistance to thermal aging

After holding each of the samples of 27-33 vulcanized rubber sheets at a temperature of 100 ° C for 48 hours, tensile tests were performed in accordance with JIS K6251; measured elongation at break (UR) and tensile strength (PR) of each of the samples 27-33 vulcanized rubber sheets, calculated the fracture force (UR × PR / 2) based on the measured values, and this fracture force was taken as an indicator of resistance to thermal aging. The results are presented in table.6.

Here, in the column “Resistance to thermal aging” of Table 6, each numerical value for samples 27-33 is expressed in relative values, taking the fracture force of sample 30 for 100.

Here, the greater numerical value in the column “Resistance to thermal aging” of Table 6 shows that the resistance to thermal aging is excellent.

Rating

As can be seen from the results presented in table 6, samples 27-29 unvulcanized rubber compounds, in which the carbon black content is reduced to 2 parts by weight, the content of silicon dioxide is 65 parts by weight. and the content of calcium stearate is not less than 2 wt.h. and not more than 10 parts by weight per 100 parts by weight the rubber component of NK have a low Mooney viscosity and excellent extrusion processability compared to sample 30 of unvulcanized rubber composition not containing calcium stearate.

In addition, as can be seen from the results presented in table 6, samples 27-29 vulcanized rubber sheets obtained by vulcanization of the corresponding samples 27-29 unvulcanized rubber compounds in which the carbon black content is reduced to 2 parts by weight, the silicon dioxide content is 65 parts by weight and the content of calcium stearate is not less than 2 wt.h. and not more than 10 parts by weight per 100 parts by weight the rubber component of NK have a high hardness and markedly superior resistance to thermal aging, compared with the vulcanized rubber sheet sample 31 obtained by vulcanizing the unvulcanized rubber composition sample 31 without calcium stearate.

In addition, as can be seen from the results presented in table 6, samples 27-29 unvulcanized rubber compounds, in which the carbon black content is reduced to 2 parts by weight, the content of silicon dioxide is 65 parts by weight. and the content of calcium stearate is not less than 2 wt.h. and not more than 10 parts by weight per 100 parts by weight the rubber component of NK is superior in extrusion processability and, after vulcanization, superior in resistance to thermal aging, sample 32 of unvulcanized rubber compound, in which the content of calcium stearate is 0.5 wt.h. per 100 parts by weight rubber component from NK.

In addition, as can be seen from the results presented in table 8, samples 27-29 vulcanized rubber sheets obtained by vulcanization of the corresponding samples 27-29 unvulcanized rubber compounds in which the carbon black content is reduced to 2 parts by weight, the silicon dioxide content is 65 parts by weight, and the content of calcium stearate is not less than 2 parts by weight and not more than 10 parts by weight per 100 parts by weight the rubber component of the NC, have a high hardness and are superior in resistance to thermal aging, the sample 33 of the vulcanized rubber sheet, in which the content of calcium stearate is 12 wt.h. per 100 parts by weight rubber component from NK.

Therefore, as can be seen from the above results, it can be assumed that if the bead filler is made using samples 27-29 of an unvulcanized rubber compound, compared with the case when the bead filler is made using samples 30-33 of an unvulcanized rubber mixture, the resulting shape and the properties of the bead apex can be reduced, and the stability of the tire during a long run of the car can be improved.

In addition, since the rubber composition of sample 30 had a too high Mooney viscosity, edge damage occurred during extrusion molding.

In addition, the vulcanized rubber sheet sample 31 obtained by vulcanizing the rubber mixture sample 31 had a too low hardness and significantly worse resistance to thermal aging compared to the vulcanized rubber sheet samples 27-29.

In addition, the sample 32 of the rubber composition had the worst extrusion processability and, after vulcanization, the worst resistance to thermal aging, compared with samples 27-29 rubber compounds.

In addition, the vulcanized rubber sheet sample 33 obtained by vulcanizing the rubber compound sample 33 had a low hardness and worse resistance to thermal aging, compared with the vulcanized rubber sheet samples 27-29.

In addition, samples 28-29 of unvulcanized rubber compounds, in which the content of calcium stearate is not less than 5 parts by weight and not more than 10 parts by weight per 100 parts by weight the rubber component significantly exceeded in extrusion technology the sample 27 of the uncured rubber compound, in which the content of calcium stearate is outside this range.

In accordance with the present invention, a rubber composition for coating a carcass cord can be obtained in which the amount of material obtained from oil sources can be reduced, and at the same time, this mixture will make the rolling resistance of the tire and the durability of the tire excellent; it is possible to provide a carcass and a tire obtained using a rubber composition for coating a carcass cord, as well as a method for manufacturing a tire.

In accordance with the present invention, a rubber composition for a tread base can be obtained in which the amount of material obtained from oil sources can be reduced, and at the same time this mixture will make the tire rolling resistance and tire durability excellent; and it is also possible to provide a tread base and a tire obtained using a rubber composition for a tread base.

In accordance with the present invention, a rubber composition can be obtained for forming a sidewall of a tire, in which the amount of the used component obtained from oil sources can be reduced, and which has better workability in the unvulcanized state and can suppress the decrease in rubber strength after thermal aging after vulcanization; and a sidewall and tire obtained using this rubber composition may also be provided.

In accordance with the present invention, a rubber composition can be obtained for forming a crimp portion of a tire, where the amount of the component used from oil sources can be reduced, and which has better processability in the unvulcanized state and contributes to the production of rubber having high wear resistance and high strength after vulcanization, the crimp part and tire obtained using this rubber compound can also be provided.

In accordance with the present invention, a rubber composition for BSHL, BSHL and a tire can be obtained, where the decrease in rubber strength due to thermal aging can be suppressed, and at the same time, the adhesion properties between the rubber and the cord can be improved, moreover, a reduction in the amount used component obtained from oil sources.

In accordance with the present invention, a rubber composition for a bead apex, a bead apex and a tire can be obtained, where the amount of component used from oil sources can be reduced, and at the same time this rubber composition has excellent molding processability, and resistance can be improved thermal aging and hardness of the bead filler after vulcanization.

Although the present invention is described in detail and demonstrated, it is obvious that this is done only for illustration and example and is not a limitation, and the scope of the present invention is indicated in the attached claims.

Claims (8)

1. The rubber composition for a tire element, where the tire element is a carcass cord coating comprising a rubber component comprising at least one of rubbers such as natural rubber and epoxidized natural rubber, silicon dioxide containing at least 60 parts by weight. and not more than 80 parts by weight per 100 parts by weight the specified rubber component, calcium stearate with a content of at least 1 wt.h. and not more than 10 parts by weight per 100 parts by weight the specified rubber component, and a silane coupling agent with a content of at least 1 wt.h. and not more than 15 parts by weight per 100 parts by weight the specified rubber component. 2. The rubber composition for a tire element, where the tire element is a tread base comprising a rubber component comprising at least one of rubbers such as natural rubber and epoxidized natural rubber, silicon dioxide containing at least 25 parts by weight. and not more than 80 parts by weight per 100 parts by weight the specified rubber component, calcium stearate with a content of at least 1 wt.h. and not more than 10 parts by weight per 100 parts by weight the specified rubber component, and a silane coupling agent with a content of at least 1 wt.h. and not more than 15 parts by weight per 100 parts by weight the specified rubber component. 3. The rubber composition for the tire element, where the tire element is a sidewall, comprising a rubber component containing at least one of such rubbers as natural rubber and epoxidized natural rubber, silicon dioxide with a content of at least 15 parts by weight and not more than 60 parts by weight per 100 parts by weight the specified rubber component and calcium stearate with a content of at least 2 wt.h. per 100 parts by weight the specified rubber component. 4. The rubber composition for a tire element, where the tire element is a crimp portion comprising a rubber component comprising at least one of rubbers such as natural rubber and epoxidized natural rubber, silicon dioxide containing at least 60 parts by weight. per 100 parts by weight the specified rubber component and calcium stearate with a content of at least 2 wt.h. and not more than 10 parts by weight per 100 parts by weight the specified rubber component. 5. The rubber composition for the tire element, where the tire element is a seamless tape comprising a rubber component containing at least one of rubbers such as natural rubber and epoxidized natural rubber, silicon dioxide with a content of at least 40 parts by weight per 100 parts by weight the specified rubber component and calcium stearate with a content of not less than 0.5 wt.h. and not more than 10 parts by weight per 100 parts by weight the specified rubber component. 6. The rubber composition for the tire element, where the tire element is a bead apex comprising a rubber component containing at least one of rubbers such as natural rubber and epoxidized natural rubber, silicon dioxide with a content of at least 60 parts by weight. per 100 parts by weight the specified rubber component and calcium stearate with a content of at least 2 wt.h. and not more than 10 parts by weight per 100 parts by weight the specified rubber component. 7. The tire element formed using the rubber composition for the tire according to claims 1 to 6. 8. A tire made using the tire element according to claim 7.

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