JP2001329118A - Rubber composition and solid tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rubber composition, improved in abrasion resistance and chip-cutting resistance, and also to provide a pneumatic tire by using the rubber composition, improved in the abrasion resistance and chip-cutting resistnace as its tread rubber. SOLUTION: This rubber composition is characterized by exhibiting >=22.0 MPa tensile strength (TB) in JIS K 6301, >=300% elongation (EB) in the JIS K 6301, >=75 hardness in the JIS K 6301 and also >=7,000 of above tensile strength (TB) × above elongation (EB).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a rubber composition having improved processability while maintaining abrasion resistance and chip-cut resistance. The present invention also relates to a heavy duty solid tire using the rubber composition for a tread rubber.

[0002]

2. Description of the Related Art Rubber compositions for tire treads include natural rubber (NR) and styrene-butadiene copolymer rubber (S).
Rubbers such as BR) and polybutadiene rubber (BR) are used, and carbon black or the like is blended as a reinforcing filler for these rubbers.

In order to improve the mixing processability, rubber elasticity, heat generation, abrasion resistance and mechanical properties of a rubber composition for a tire tread, the type and molecular weight of the rubber composition for a tire tread described above are improved. The types, characteristics and blending amounts of the carbon black, and the types and blending amounts of the oils to be blended are appropriately set.

For example, in order to improve the abrasion resistance and the like of a rubber composition, it is known to use carbon black having a small particle size and a large specific surface area, or to increase the amount of carbon black.

[0005] However, these methods increase the viscosity of the rubber composition, significantly lowering the kneading workability, and further worsening the dispersion of carbon black. At the same time, there is a disadvantage that the heat build-up of the rubber composition is increased.

In order to improve the abrasion resistance and the like of the rubber composition for a tire tread, Japanese Patent Application Laid-Open No.
264647, JP-A-64-74242,
JP-A-1-144434, JP-A-2-22348
And Japanese Patent Application Laid-Open Nos. 2-286727 and 6-93137.

[0007] On the other hand, industrial vehicles such as forklifts transport and convey heavy loads, and when transporting and transporting heavy loads, tires of industrial vehicles have high loads. It will take. When a heavy load is applied to a tire, the tire may be worn or a chip may be cut.

[0008] However, the above-mentioned techniques are insufficient for the improvement of wear resistance and chip-cut resistance of a rubber composition for a tire tread used for an industrial vehicle.

In order to improve the abrasion resistance and chip-cut resistance of a rubber composition for a tire tread used for industrial vehicles, specific carbon having a sharp secondary aggregate distribution is mixed into the rubber composition. Technology has been proposed,
Even in such a case, there is a problem that the rubber viscosity of the rubber composition is increased and the processability is deteriorated. for that reason,
It is possible to lower the rubber viscosity of the rubber composition by adding a softener such as oil or IR, but at the same time, there is a problem that the modulus level is lowered and the wear resistance is also deteriorated.

[0010]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a rubber composition for a tire tread used in an industrial vehicle, which has improved abrasion resistance and chip-cut resistance. Another object of the present invention is to provide a solid tire using a tread rubber with a rubber composition having excellently improved wear resistance and chip-cut resistance.

[0011]

The rubber composition according to the present invention has a tensile strength (T _B ) in JIS K 6301 of 22.0 MPa or more and an elongation in JIS K6301 as described in claim 1. (E _B ) is 3
00% or more, the hardness according to JIS K6301 is 75 or more, and the tensile strength (T _B )
X The rubber composition having the elongation (E _B ) of 7000 or more.

Further, the rubber composition according to the present invention has a tensile strength (T _B ) according to JIS K 6301 of 25.0 MPa or more, and
The elongation (E _B ) in ISK 6301 is 500% or more, and the hardness in JIS K6301 is 63
The rubber composition has a tensile strength (T _B ) × the elongation (E _B ) of 12,000 or more and not more than 76.

Further, the solid tire according to the present invention is a solid tire obtained by using the rubber composition according to claim 1 for a tread rubber.

Further, the solid tire according to the present invention is a solid tire using the rubber composition according to claim 2 for a tread rubber.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventor has adopted JIS K630
1, the tensile strength (T _B ) is 22.0 MPa or more, the elongation (E _B ) in JIS K 6301 is 300% or more, and JIS K 6301
A rubber composition having a hardness of 301 or more and a tensile strength (T _B ) × elongation (E _B ) of 7000 or more is excellent in chip-cut resistance and abrasion resistance. The present invention has been completed based on the new finding that

When the tensile strength (T _B ) according to JIS K 6301 is less than 22.0 MPa, there is a case where breakage or the like occurs against the torsional behavior under the compressive condition under a high load, which is disadvantageous. Also, JIS K
Even if the elongation (E _B ) at 6301 is less than 300%, it is disadvantageous for the torsional behavior under compressive conditions under high load. In addition, JIS K 6301
If the hardness is less than 75, road tire performance tends to be inferior.

The tensile strength (T _B ) × the elongation (E _B ) is defined as the breaking energy (% × MPa). If the breaking energy is less than 7,000, satisfactory values can be obtained in chip-cutting resistance and abrasion resistance. Is not shown.

The above rubber composition can be manufactured as shown below. That is, natural rubber (N
R), a raw rubber component having at least one of a conjugated diolefin homopolymer or a copolymer of a conjugated diolefin and an ethylenically unsaturated monomer is prepared.

Then, 5 to 50 parts by weight of carbon black 1 and 20 to 50 parts by weight of carbon black 2 are added to 100 parts by weight of the raw rubber component. Here, the carbon black 1 has a nitrogen adsorption specific surface area (hereinafter, referred to as N ₂ SA) of 90 to 140 m ² / g.
In dibutyl phthalate absorption (hereinafter referred to as DBP oil absorption.) Good carbon black having a property of being 70~140cm ³ / 100g, The carbon black 2, N ₂ SA is at 50~90m ² / g , DBP oil absorption is 3
It refers to a carbon black having a characteristic which is 0~120cm ³ / 100g.

Further, the total amount of carbon, which is the total amount of carbon black 1 and carbon black 2, must be 50 to 80 parts by weight based on 100 parts by weight of the raw rubber component. When the total carbon amount is less than 50 parts by weight, when a solid tire is manufactured using such a rubber composition, the wear resistance of the solid tire tends to be deteriorated. In addition, when the total carbon amount is more than 80 parts by weight, when a solid tire is manufactured using such a rubber composition, the chip cut resistance of the solid tire may be deteriorated. Because.

Carbon black 1 and carbon black 2 are added to 100 parts by weight of the raw rubber component, and sulfur and a vulcanization accelerator are further added. Here, the weight ratio of sulfur to the vulcanization accelerator (weight of sulfur / weight of vulcanization accelerator) needs to be 1.5 or more.
When the (weight of sulfur / weight of the vulcanization accelerator) is less than 1.5, the decrease in elongation of the rubber composition is increased, and when a solid tire is manufactured using such a rubber composition. This is because the chip cut resistance of the solid tire tends to deteriorate. In addition, as the vulcanization accelerator, a plurality of types can be mixed and used, but when a plurality of types are mixed and used, the total weight of all the vulcanization accelerators is used. The ratio of the weight of the vulcanization accelerator to the weight of sulfur is calculated. That is, in such a case, (weight of sulfur / weight of total vulcanization accelerator) needs to be 1.5 or more.

Therefore, the method for producing a rubber composition according to the present invention is characterized in that at least one of natural rubber (NR), a homopolymer of a conjugated diolefin, or a copolymer of a conjugated diolefin and an ethylenically unsaturated monomer is used. 5 to 50 parts by weight of carbon black 1 and 2 parts of carbon black 2 based on 100 parts by weight of the raw rubber component
0 to 50 parts by weight, so that the total amount of carbon black 1 and carbon black 2 is 50 to 80 parts by weight based on 100 parts by weight of the raw rubber component, and further, sulfur and a vulcanization accelerator are added. , And vulcanization by heating and then vulcanizing by adding each such that the weight ratio of sulfur to the vulcanization accelerator (sulfur / vulcanization accelerator) is 1.5 or more. You can do it.

Further, the present inventor has proposed JIS K 6301.
In a tensile strength (T _B) together is more than 25.0 MPa, elongation at JIS K 6301 (E _B)
Is not less than 500%, the hardness according to JIS K6301 is not less than 63 and not more than 76, and the tensile strength (T _B ) × the elongation (E _B ) is not less than 12,000, The present invention has been completed based on the new finding that the cutting property is excellent and the abrasion resistance is also excellent.

When the tensile strength (T _B ) according to JIS K 6301 is smaller than 25.0 MPa, there is a case where breakage and tearing may be disadvantageous to the torsional behavior under a compressive condition under a high load. is there. Also, JI
Even if the elongation (E _B ) in SK 6301 is less than 500%, it is disadvantageous for the torsional behavior under compressive conditions under high load.

The hardness according to JIS K6301 is 63
If it is less than 30, even if a solid tire is manufactured using such a rubber composition, the running stability of the solid tire tends to deteriorate. Also, JIS K
If the hardness at 6301 is more than 76, even if a solid tire is manufactured using such a rubber composition, there is a possibility that a problem may occur in the drive tire characteristics of the solid tire.

The tensile strength (T _B ) × the elongation (E _B ) is defined as the breaking energy (% × MPa). If the breaking energy is less than 12,000, satisfactory values can be obtained in chip-cut resistance and wear resistance. It is not shown, and there is a case where there is a problem in convenience as a solid tire.

The above rubber composition can be produced as shown below. That is, natural rubber (N
R), a raw rubber component having at least one of a conjugated diolefin homopolymer or a copolymer of a conjugated diolefin and an ethylenically unsaturated monomer is prepared.

Then, 40 to 70 parts by weight of carbon black 2 is added to 100 parts by weight of the raw rubber component.
It is also possible to add carbon black 3 together with carbon black 2. In addition, carbon black 3 means that N ₂ SA is 20 to 50 m ² / g and DB
P oil absorption refers to the carbon black having a property of being 60~130cm ³ / 100g. Carbon black 3
Is added together with the carbon black 2, the total amount of carbon, which is the total amount of the carbon black 2 and the carbon black 3, is 40 to 70 parts by weight based on 100 parts by weight of the raw rubber component. It is necessary to be. When the total carbon amount is less than 40 parts by weight, when a solid tire is manufactured using such a rubber composition, the abrasion resistance of the solid tire tends to deteriorate. In addition, when the total carbon amount is 70
If the amount is more than the weight part, when a solid tire is manufactured using such a rubber composition, the chip cut resistance of the solid tire may be deteriorated.

Carbon black 2 is added to 100 parts by weight of the raw rubber component, and sulfur and a vulcanization accelerator are further added. Here, the weight ratio of sulfur to the vulcanization accelerator (weight of sulfur / weight of vulcanization accelerator) needs to be 1.5 or more. When the (weight of sulfur / weight of the vulcanization accelerator) is less than 1.5, the decrease in elongation of the rubber composition is increased, and when a solid tire is manufactured using such a rubber composition. This is because the chip cut resistance of the solid tire tends to deteriorate.
In addition, as the vulcanization accelerator, a plurality of types can be mixed and used, but when a plurality of types are mixed and used, the total weight of all the vulcanization accelerators is used. The ratio of the weight of the vulcanization accelerator to the weight of sulfur is calculated. That is, in such a case, (weight of sulfur / weight of total vulcanization accelerator) needs to be 1.5 or more.

Therefore, the method for producing a rubber composition according to the present invention is characterized in that at least one of natural rubber (NR), a homopolymer of a conjugated diolefin, or a copolymer of a conjugated diolefin and an ethylenically unsaturated monomer is used. Carbon black 2 is added in an amount of 40 to 70 parts by weight to 100 parts by weight of the raw rubber component, and sulfur and the vulcanization accelerator are in a weight ratio of sulfur to the vulcanization accelerator (sulfur / vulcanization accelerator). (Accelerator) is 1.5 or more, and the mixture is heated and vulcanized by heating to obtain a rubber composition. It is possible to mix carbon black 3 with the raw rubber component together with carbon black 2, but even in such a case, the raw rubber component 1
It is necessary that the total amount of carbon black 2 and carbon black 3 be added in a state of 40 to 70 parts by weight with respect to 00 parts by weight.

As the rubber component in the raw rubber component,
As described above, a raw rubber component having at least one of natural rubber (NR), a homopolymer of a conjugated diolefin, or a copolymer of a conjugated diolefin and an ethylenically unsaturated monomer is used. Can use a rubber component containing at least one of natural rubber (NR) and diene-based synthetic rubber. Examples of the diene-based synthetic rubber include styrene-butadiene rubber (SBR), polybutadiene rubber (BR), Polyisoprene rubber (IR), ethylene-propylene-diene rubber (EPDM), chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR), and the like can be used, and one or more rubber components are used in the present invention. May be included. In addition, ethylene-propylene-diene rubber (EPDM) is a material containing a third diene component in ethylene-propylene rubber (EPM),
Here, the third diene component is a non-conjugated diene having 5 to 20 carbon atoms, such as 1,4-pentadiene and 1,4-pentadiene.
Hexadiene, 1,5-hexadiene, 2,5-dimethyl-1,5-hexadiene and 1,4-octadiene, and cyclic dienes such as 1,4-cyclohexadiene, cyclooctadiene and dicyclopentadiene, for example, 5- Examples include alkenyl norbornene such as ethylidene-2-norbornene, 5-butylidene-2-norbornene, 2-methallyl-5-norbornene and 2-isopropenyl-5-norbornene, and among diene, dicyclopentadiene, 5 -Ethylidene-2-
Norbornene and the like can be preferably used.

In preparing the rubber composition according to the present invention,
It is necessary to mix a vulcanizing agent. The rubber composition is prepared by kneading with a Banbury mixer or the like. As the vulcanizing agent, an organic peroxide or a sulfur-based vulcanizing agent can be used, and a mixture thereof can also be used as the vulcanizing agent. After mixing the vulcanizing agent, the rubber composition can be obtained by a vulcanization reaction by heating.

As the organic peroxide, for example, benzoyl peroxide, dicumyl peroxide, di-t
-Butyl peroxide, t-butylcumyl peroxide, methyl ethyl ketone peroxide, cumene hydroperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5 Di (benzoylperoxy) hexane, 2,
5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 or 1,3-bis (t-butylperoxypropyl) benzene, di-t-butylperoxy-diisopropylbenzene, t-butylperoxy Oxybenzene, 2,4-dichlorobenzoyl peroxide, 1,
1-di-t-butylperoxy-3,3,5-trimethylsiloxane, n-butyl-4,4-di-t-butylperoxyvalerate and the like can be used. Among them, dicumyl peroxide, t-butylperoxybenzene and di-t-butylperoxy-diisopropylbenzene are suitable for appropriately vulcanizing the rubber composition.

As the sulfur vulcanizing agent, for example, sulfur,
Morpholine disulfide and the like can be used.
Of these, sulfur is preferred. As the sulfur, powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur and the like can be used.

In preparing the rubber composition according to the present invention, a vulcanization accelerator can be added in addition to the vulcanizing agent in order to carry out vulcanization efficiently in a short time. As the vulcanization accelerator, sulfenamide compounds, thiazole compounds,
A thiuram-based compound, a thiourea-based compound, a guanidine-based compound, a dithiocarbamic acid-based compound, an aldehyde-amine-based or aldehyde-ammonia-based compound, an imidazoline-based compound, and a xanthate-based compound can be used, and a mixture thereof is also used. It is possible.

Examples of the sulfenamide compound include CBS (N-cyclohexyl-2-benzothiazylsulfenamide) and TBBS (N-tert-butyl-
2-benzothiazylsulfenamide), N, N-dicyclohexyl-2-benzothiazylsulfenamide,
It is possible to use N-oxydiethylene-2-benzothiazylsulfenamide, N, N-diisopropyl-2-benzothiazolesulfenamide and the like.

As the thiazole compound, for example,
MBT (2-mercaptobenzothiazole), MBTS
(Dibenzothiazyl disulfide), sodium salt, zinc salt, copper salt, cyclohexylamine salt of 2-mercaptobenzothiazole, 2- (2,4-dinitrophenyl)
It is possible to use mercaptobenzothiazole, 2- (2,6-diethyl-4-morpholinothio) benzothiazole and the like.

As the thiuram-based compound, for example, T
MTD (tetramethylthiuram disulfide), tetraethylthiuram disulfide, tetramethylthiuram monosulfide, dipentamethylenethiuram disulfide, dipentamethylenethiuram monosulfide, dipentamethylenethiuram tetrasulfide, dipentamethylenethiuram hexasulfide, tetrabutylthiuram disulfide, Pentamethylenethiuram tetrasulfide and the like can be used.

As the thiourea compound, for example,
It is possible to use thiacarbamide, diethylthiourea, dibutylthiourea, trimethylthiourea, dioltotolylthiourea and the like.

As the guanidine compound, for example,
It is possible to use diphenylguanidine, diortitolylguanidine, triphenylguanidine, orthotolylbiguanide, diphenylguanidine phthalate and the like.

Examples of the dithiocarbamic acid-based compound include zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, zinc diamildithiocarbamate,
Zinc dipropyldithiocarbamate, complex salt of zinc pentamethylenedithiocarbamate and piperidine, zinc hexadecyl (or octadecyl) isopropyldithiocarbamate, zinc dibenzyldithiocarbamate, sodium diethyldithiocarbamate, piperidine pentamethylenedithiocarbamate, selenium dimethyldithiocarbamate, diethyldithiocarbamine It is possible to use tellurium acid, cadmium diamyldithiocarbamate and the like.

Aldehyde-amine or aldehyde-
As the ammonia-based compound, an acetaldehyde-aniline reactant, a butyraldehyde-aniline condensate, hexamethylenetetramine, an acetaldehyde-ammonia reactant, or the like can be used.

As the imidazoline compound, for example, an imidazoline compound such as 2-mercaptoimidazoline can be used, and as the xanthate compound, for example, zinc dibutylxanthogenate can be used.

In preparing the rubber composition of the present invention, a softener may be used in combination, if desired, in order to further improve the kneading processability. Such softeners include, for example, process oils, lubricating oils, paraffins,
Liquid paraffin, petroleum asphalt, petroleum softener such as petrolatum; castor oil, linseed oil, rapeseed oil, fatty oil softener such as coconut oil; tall oil; sub; waxes such as beeswax, carnauba wax, lanolin; It is possible to use acids, palmitic acid, stearic acid, lauric acid and the like.

When the rubber composition of the present invention is prepared, an antioxidant can be added to improve the durability of the rubber composition. Anti-aging agents (ie, anti-deterioration agents) include amines, phenols,
It is possible to use imidazoles, metal carbamates, waxes and the like.

When the rubber composition of the present invention is prepared, a white filler may be contained for the purpose of reinforcing the rubber composition. As the white filler, specifically, silica, clay, alumina, talc, calcium carbonate, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, magnesium oxide, titanium oxide, and the like can be used. They can be used alone or in combination of two or more. Particularly preferred white fillers are silica, clay, aluminum hydroxide and alumina. The compounding amount of the white filler contained in the rubber composition of the present invention is 5 to 65 parts by weight based on 100 parts by weight of the rubber component used in the present invention. If the amount of the white filler is less than 5 parts by weight, the reinforcing effect is small, and if it exceeds 65 parts by weight, the workability may be deteriorated, which is not preferable. From the viewpoint of low heat generation and workability, the amount of the white filler is preferably 65 parts by weight or less.

A silane coupling agent can be blended to prevent the white filler from settling. That is, the silane coupling agent bonds to the white filler and the polymer (rubber component) due to its chemical structure, so that the bond between the white filler and the rubber component is strongly strengthened via the silane coupling agent. it can. As a silane coupling agent, bis (triethoxysilylpropyl)
Tetrasulfide (for example, Si96 manufactured by Degussa,
Shin-Etsu Chemical's KBE846 and OSI Specialty's A-1289 and A-189 are preferably used. The silane coupling agent is not limited to one type, and a plurality of types of silane coupling agents having a thiol-based, amine-based, or halogen-based functional group may be mixed and used.

In preparing the rubber composition of the present invention, a foaming agent may be added. Examples of the foaming agent include organic compounds such as azodicarbonamide, azobisisobutyronitrile, dinitrosopentamethylenetetramine, hydrazodicarbonamide, and p-toluenesulfonylacetone hydrazone;
An inorganic material such as ₃ can be used.

The tensile strength (T _B ) in JIS K 6301 is 22.0 MPa or more, and
The elongation (E _B ) in K 6301 is 300% or more, and the hardness in JIS K 6301 is 75%.
The rubber composition having the tensile strength (T _B ) × the elongation (E _B ) of 7000 or more has excellent wear resistance and chip-cut resistance. Therefore, a solid tire using this as a tread rubber is particularly suitable for a tire used in an industrial vehicle such as a forklift. A conventional method can be used for manufacturing a solid tire. For example, a solid tire is manufactured through a vulcanization step of molding a tire green cover with a vulcanization mold. In the vulcanization step, the uncured tire green cover is inserted into a heated mold, and pressure is applied to the inner surface of the tire green cover via a bladder to form the tire green cover into a mold for molding the tire. This is performed by closely adhering to the surface. The raw tire cover is obtained by molding a carcass, a belt, rubber and the like in advance.

The tensile strength (T _B ) in JIS K 6301 is 25.0 MPa or more, and
The elongation (E _B ) in K 6301 is 500% or more, and the hardness in JIS K 6301 is 63
The rubber composition having a tensile strength (T _B ) × the elongation (E _B ) of not less than 76 and not more than 12,000 is as follows:
Excellent wear resistance and excellent chip cut resistance. Therefore, a solid tire using this as a tread rubber is particularly suitable for a tire used in an industrial vehicle such as a forklift. A conventional method can be used for manufacturing a solid tire.

The manufactured solid tire has a toroidal shape with bead portions provided at the respective inner ends of the sidewall portions extending radially inward from both ends of the tread portion. Further, the solid tire is reinforced by a cord layer including a carcass bridged between the bead portions and a breaker arranged radially outside of the carcass and inside the tread portion, so that the necessary tire strength and rigidity are obtained. Granted. The bead portion is provided with a bead apex rubber having a triangular cross section extending radially outward from the bead core to increase the bead rigidity. The solid tire according to the present invention can be used not only for industrial vehicles but also for general vehicles.

[0052]

EXAMPLES Tensile strength (T) according to JIS K6301
_B ) is 22.0 MPa or more and JIS K
The elongation (E _B ) at 6301 is 300% or more, and the tensile strength (T _B ) × the elongation (E _B ) is 7%.
The fact that the rubber composition having a molecular weight of 000 or more is excellent in chip-cut resistance and also in abrasion resistance is shown in Examples 1 to 4 shown below in comparison with Comparative Examples 1 to 5.

(Example 1) 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 30 parts by weight of carbon black 1 and 30 parts by weight of carbon black 2
Parts by weight, 3 parts by weight of aromatic oil, 5 parts by weight of phenol-modified resin
Parts by weight, 2.5 parts by weight of sulfur, 0.7 parts by weight of a sulfenamide-based vulcanization accelerator, and 0.4 parts by weight of an aldehyde-ammonia-based vulcanization accelerator are mixed and vulcanized. Thus, a rubber composition was obtained. NR (natural rubber)
Used STR20 (manufactured by TECK BEE HANG). BR (polybutadiene rubber) is BR15
(Nippon Synthetic Rubber Co., Ltd.) was used. Carbon black 1 used was Show Black N2201 (manufactured by Showa Cabot). The carbon black 2 used was Seast 3 (manufactured by Tokai Carbon Co., Ltd.). As the phenol-modified resin, PR12686 (manufactured by Sumitomo Durez) was used.

The tensile strength of the rubber composition is JIS K 63
01 was 19.8 MPa. The elongation of the rubber composition was 290% as measured by JIS K6301. The hardness of the rubber composition was 77 as measured by a spring hardness test according to JIS K6301. The breaking energy is 5742 (MPa)
·%)Met.

The wear resistance was measured according to JIS K6242. The abrasion resistance in Example 1, the following Examples 2 to 4 and Comparative Examples 2 to 5 was determined in Comparative Example 1 shown below.
Is represented by an index with the value of 100 as 100.
The larger the index, the better the abrasion resistance. The abrasion resistance in Example 1 was 141.

The chip-cut resistance was measured as described below. That is, a needle mountain block in which three pieces of iron quenching pins each having a diameter of 5 mm are embedded on each side of an iron hexahedron made of an equilateral triangle having a diameter of 45 mm, with an inner diameter of 15 mm.
A vulcanization molding using a molding frame was performed on a 5 mm, 177 mm height cylindrical iron container inner surface, and the weight was measured in advance to 120 m.
Six sample rubbers of mx 82 mm x 5 mm (thickness) were fixed in the drum. After that, the temperature inside the drum is reduced to about 70 ° C.
After rotating for 7 days at a speed of 36 rpm, remove the needle mountain block, remove the sample rubber from the drum, completely remove the attached rubber chips, measure the weight, and change the specific gravity to volume. By conversion, the volume change rate was determined. The chip-cutting resistance in Example 1, Examples 2 to 4 and Comparative Examples 2 to 5 shown below is represented by an index with the value in Comparative Example 1 shown below being 100. The larger the index is, the better the chip cut resistance is. The chip-cut resistance in Example 1 was 121.

Example 2 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 40 parts by weight of carbon black 1 and 30 parts by weight of carbon black 2
Parts by weight, 3 parts by weight of aromatic oil, 5 parts by weight of phenol-modified resin
Parts by weight, 2.5 parts by weight of sulfur, 0.7 parts by weight of a sulfenamide-based vulcanization accelerator, and 0.4 parts by weight of an aldehyde-ammonia-based vulcanization accelerator are mixed and vulcanized. Thus, a rubber composition was obtained. Each of the compounds used had the same trade name as the compound used in Example 1 described above.

The tensile strength of the rubber composition is JIS K 63
01, it was 23.9 MPa. The elongation of the rubber composition was 320% as measured by JIS K6301. The hardness of the rubber composition was 82 as measured by a spring hardness test according to JIS K6301. The breaking energy is 7648 (MPa)
·%)Met. The wear resistance is measured according to JIS K 6242 and, as described above, is represented by an index with the value in Comparative Example 1 shown below being 100. The abrasion resistance in Example 2 was 153. The chip-cut resistance is measured in the same manner as in the measurement method described in Example 1 described above, and is represented by an index with the value in Comparative Example 1 shown below being 100. The chip cut resistance in Example 2 was 117.

(Example 3) 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 20 parts by weight of carbon black 1 and 40 parts by weight of carbon black 2
Parts by weight, 3 parts by weight of aromatic oil, 5 parts by weight of phenol-modified resin
Parts by weight, 2.5 parts by weight of sulfur, 0.7 parts by weight of a sulfenamide-based vulcanization accelerator, and 0.4 parts by weight of an aldehyde-ammonia-based vulcanization accelerator are mixed and vulcanized. Thus, a rubber composition was obtained. Each of the compounds used had the same trade name as the compound used in Example 1 described above.

The tensile strength of the rubber composition is JIS K 63
As a result, it was 23.2 MPa. The elongation of the rubber composition was 370% as measured by JIS K6301. The hardness of the rubber composition was 79 as measured by a spring hardness test according to JIS K6301. The breaking energy is 8584 (MPa)
·%)Met. The wear resistance is measured according to JIS K 6242 and, as described above, is represented by an index with the value in Comparative Example 1 shown below being 100. The wear resistance in Example 3 was 139. The chip-cut resistance is measured in the same manner as in the measurement method described in Example 1 described above, and is represented by an index with the value in Comparative Example 1 shown below being 100. The chip cut resistance in Example 3 was 118.

Example 4 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 10 parts by weight of carbon black 1 and 40 parts of carbon black 2
Parts by weight, 3 parts by weight of aromatic oil, 5 parts by weight of phenol-modified resin
Parts by weight, 2.5 parts by weight of sulfur, 0.7 parts by weight of a sulfenamide-based vulcanization accelerator, and 0.4 parts by weight of an aldehyde-ammonia-based vulcanization accelerator, and vulcanization Thus, a rubber composition was obtained. Each of the compounds used had the same trade name as the compound used in Example 1 described above.

The tensile strength of the rubber composition is JIS K 63
It was 22.7 MPa when measured at 01. The elongation of the rubber composition was 380% as measured by JIS K6301. The hardness of the rubber composition was 78 as measured by a spring hardness test according to JIS K6301. The breaking energy is 8626 (MPa)
·%)Met. The wear resistance is measured according to JIS K 6242 and, as described above, is represented by an index with the value in Comparative Example 1 shown below being 100. The abrasion resistance in Example 4 was 136. The chip-cut resistance is measured in the same manner as in the measurement method described in Example 1 described above, and is represented by an index with the value in Comparative Example 1 shown below being 100. The chip-cut resistance in Example 4 was 111.

Comparative Example 1 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 30 parts by weight of carbon black 2 and 30 parts by weight of carbon black 3
Parts by weight, 3 parts by weight of aromatic oil, 5 parts by weight of phenol-modified resin
Parts by weight, 2.5 parts by weight of sulfur, 1.3 parts by weight of a sulfenamide-based vulcanization accelerator, and 0.4 parts by weight of an aldehyde-ammonia-based vulcanization accelerator are mixed and vulcanized. Thus, a rubber composition was obtained. As the carbon black 3, Nichiron # 105 (manufactured by Shin-Nikka Carbon Co., Ltd.) was used. Other formulations used had the same trade name as the formulation used in Example 1 described above.

The tensile strength of the rubber composition is JIS K 63
01 was 19.8 MPa. The elongation of the rubber composition was 290% as measured by JIS K6301. The hardness of the rubber composition was 77 as measured by a spring hardness test according to JIS K6301. The breaking energy is 5742 (MPa)
·%)Met. The wear resistance was measured according to JIS K 6242, and the value in Comparative Example 1 was set to 100 as described above. The chip cutting resistance is the same as that of Example 1 described above.
The measurement was performed in the same manner as in the measurement method shown in FIG.

Comparative Example 2 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 15 parts by weight of carbon black 1, and 30 parts by weight of carbon black 2
Parts by weight, 3 parts by weight of aromatic oil, 5 parts by weight of phenol-modified resin
Parts by weight, 2.5 parts by weight of sulfur, 0.7 parts by weight of a sulfenamide-based vulcanization accelerator, and 0.4 parts by weight of an aldehyde-ammonia-based vulcanization accelerator are mixed and vulcanized. Thus, a rubber composition was obtained. Each of the compounds used had the same trade name as the compound used in Example 1 described above.

The tensile strength of the rubber composition was determined according to JIS K63.
When measured at 01, it was 20.3 MPa. The elongation of the rubber composition was 410% as measured by JIS K6301. The hardness of the rubber composition was 77 as measured by a spring hardness test according to JIS K6301. The breaking energy is 8323 (MPa
·%)Met. The wear resistance is measured according to JIS K 6242, and expressed as an index with the value in Comparative Example 1 set to 100 as described above. The abrasion resistance in Comparative Example 2 was 96. The chip-cut resistance was measured in the same manner as in the measurement method described in Example 1 described above.
It is represented by an index with the value in Comparative Example 1 being 100. The chip-cut resistance in Comparative Example 2 was 105.

Comparative Example 3 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 60 parts by weight of carbon black 1 and 30 parts by weight of carbon black 2
Parts by weight, 3 parts by weight of aromatic oil, 5 parts by weight of phenol-modified resin
Parts by weight, 2.5 parts by weight of sulfur, 0.7 parts by weight of a sulfenamide-based vulcanization accelerator, and 0.4 parts by weight of an aldehyde-ammonia-based vulcanization accelerator are mixed and vulcanized. Thus, a rubber composition was obtained. Each of the compounds used had the same trade name as the compound used in Example 1 described above.

The tensile strength of the rubber composition was determined according to JIS K63.
It was 20.4 MPa when measured at 01. The elongation of the rubber composition was 260% as measured by JIS K6301. The hardness of the rubber composition was 84 as measured by a spring hardness test according to JIS K6301. The breaking energy is 5304 (MPa
·%)Met. The wear resistance is measured according to JIS K 6242, and expressed as an index with the value in Comparative Example 1 set to 100 as described above. The wear resistance in Comparative Example 3 was 163. Chip-cut resistance is
The measurement is performed in the same manner as in the measurement method described in Example 1 described above, and is represented by an index with the value in Comparative Example 1 being 100. The chip-cut resistance in Comparative Example 3 was 93.

Comparative Example 4 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 30 parts by weight of carbon black 2 and 30 parts by weight of carbon black 3
Parts by weight, 3 parts by weight of aromatic oil, 5 parts by weight of phenol-modified resin
Parts by weight, 2.5 parts by weight of sulfur, 1.7 parts by weight of a sulfenamide-based vulcanization accelerator, and 0.4 parts by weight of an aldehyde-ammonia-based vulcanization accelerator are mixed and vulcanized. Thus, a rubber composition was obtained. Each of the compounds used had the same trade name as the compound used in Comparative Example 1 described above.

The tensile strength of the rubber composition was determined according to JIS K63.
It was 20.7 MPa when measured at 01. The elongation of the rubber composition was 260% as measured by JIS K6301. The hardness of the rubber composition was 79 as measured by a spring hardness test according to JIS K6301. The breaking energy is 5382 (MPa
·%)Met. The wear resistance is measured according to JIS K 6242, and expressed as an index with the value in Comparative Example 1 set to 100 as described above. The wear resistance in Comparative Example 4 was 99. The chip-cut resistance was measured in the same manner as in the measurement method described in Example 1 described above.
It is represented by an index with the value in Comparative Example 1 being 100. The chip-cut resistance in Comparative Example 4 was 96.

Comparative Example 5 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 30 parts by weight of carbon black 2 and 30 parts by weight of carbon black 3
Parts by weight, 3 parts by weight of aromatic oil, 5 parts by weight of phenol-modified resin
Parts by weight, 1.8 parts by weight of sulfur, 0.7 parts by weight of a sulfenamide-based vulcanization accelerator, and 0.4 parts by weight of an aldehyde-ammonia-based vulcanization accelerator are mixed and vulcanized. Thus, a rubber composition was obtained. Each of the compounds used had the same trade name as the compound used in Comparative Example 1 described above.

The tensile strength of the rubber composition was determined according to JIS K63.
01, it was 16.5 MPa. The elongation of the rubber composition was 330% as measured by JIS K6301. The hardness of the rubber composition was 73 as measured by a spring hardness test according to JIS K6301. The breaking energy is 5445 (MPa)
·%)Met. The wear resistance is measured according to JIS K 6242, and expressed as an index with the value in Comparative Example 1 set to 100 as described above. The wear resistance in Comparative Example 5 was 91. The chip-cut resistance was measured in the same manner as in the measurement method described in Example 1 described above.
It is represented by an index with the value in Comparative Example 1 being 100. The chip-cut resistance in Comparative Example 5 was 94.

The above Examples 1 to 4 and Comparative Examples 1 to 5
Are shown in Table 1 below. It is understood that the rubber compositions according to Examples 1 to 4 show good values in both wear resistance and chip-cut resistance. On the other hand, in Comparative Examples 1 to 5, either the wear resistance or the chip cut resistance is insufficient. Or
Comparative Examples 1 to 5 show insufficient values in any of the wear resistance and the chip cut resistance.

[0074]

[Table 1]

Next, while the tensile strength (T _B ) according to JIS K 6301 is 25.0 MPa or more,
The elongation (E _B ) in IS K 6301 is 500% or more, the hardness in JIS K 6301 is 63 or more and 76 or less, and the tensile strength (T _B )
× The fact that the rubber composition having an elongation (E _B ) of 12000 or more is excellent in chip-cut resistance and abrasion resistance is shown in Comparative Examples 6 to 9 in Examples 5 to 9 below. This is shown in comparison with Nos.

Example 5 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 50 parts by weight of carbon black 2, 8 parts by weight of aromatic oil, and 2.6 parts by weight of sulfur Parts of a sulfenamide-based vulcanization accelerator in 0.1 part.
A rubber composition was obtained by mixing and vulcanizing 7 parts by weight of each. Each of the compounds used had the same trade name as the compound used in Example 1 described above.

The tensile strength of the rubber composition is JIS K 63
01, it was 25.7 MPa. The elongation of the rubber composition was 550% as measured by JIS K6301. The hardness of the rubber composition was 65 as measured by a spring hardness test in JIS K6301. The breaking energy is 14135 (MP
a.%).

The abrasion resistance was measured according to JIS K 6242. The wear resistance in Example 5, the following Examples 6 to 9 and Comparative Examples 6 to 11 is represented by an index with the value in Comparative Example 6 shown below being 100. The larger the index, the better the abrasion resistance. The abrasion resistance in Example 5 was 98.

The chip-cut resistance is measured in the same manner as in the above-described measurement method of Example 1, and is represented by an index with the value of Comparative Example 6 shown below being 100. Example 5
Was 113.

Example 6 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 50 parts by weight of carbon black 2 and 10 parts by weight of carbon black 3
Parts by weight, 8 parts by weight of aromatic oil, 2.6 parts by weight of sulfur, and 0.7 parts by weight of a sulfenamide-based vulcanization accelerator were mixed and vulcanized to obtain a rubber composition. Each of the compounds used had the same trade name as the compound used in Comparative Example 1 described above.

The tensile strength of the rubber composition is JIS K 63
01, it was 26.5 MPa. The elongation of the rubber composition was 530% as measured by JIS K6301. The hardness of the rubber composition was 67 as measured by a spring hardness test according to JIS K6301. The breaking energy is 14045 (MP
a.%). Abrasion resistance is based on JIS K 6242
And Comparative Example 6 shown below as described above.
Is represented by an index with the value of 100 as 100.
The wear resistance in Example 6 was 102. The chip cut resistance was measured in the same manner as in the measurement method described in Example 1 described above, and the value in Comparative Example 6 shown below was set to 100
Expressed as an exponent. The chip cut resistance in Example 6 was 110.

(Example 7) 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 50 parts by weight of carbon black 2 and 20 parts by weight of carbon black 3
Parts by weight, 8 parts by weight of aromatic oil, 2.6 parts by weight of sulfur, and 0.7 parts by weight of a sulfenamide-based vulcanization accelerator were mixed and vulcanized to obtain a rubber composition. Each of the compounds used had the same trade name as the compound used in Comparative Example 1 described above.

The tensile strength of the rubber composition was determined according to JIS K63.
01 was 26.9 MPa. The elongation of the rubber composition was 510% as measured by JIS K6301. The hardness of the rubber composition was measured by a spring hardness test according to JIS K6301, and was 69. The breaking energy is 13719 (MP
a.%). Abrasion resistance is based on JIS K 6242
And Comparative Example 6 shown below as described above.
Is represented by an index with the value of 100 as 100.
The wear resistance in Example 7 was 105. The chip cut resistance was measured in the same manner as in the measurement method described in Example 1 described above, and the value in Comparative Example 6 shown below was set to 100
Expressed as an exponent. The chip cut resistance in Example 7 was 106.

Example 8 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 40 parts by weight of carbon black 2 and 20 parts by weight of carbon black 3
Parts by weight, 8 parts by weight of aromatic oil, 2.6 parts by weight of sulfur, and 0.7 parts by weight of a sulfenamide-based vulcanization accelerator were mixed and vulcanized to obtain a rubber composition. Each of the compounds used had the same trade name as the compound used in Comparative Example 1 described above.

The tensile strength of the rubber composition is JIS K 63
It was 26.1 MPa when measured at 01. The elongation of the rubber composition was 550% as measured by JIS K6301. The hardness of the rubber composition was 67 as measured by a spring hardness test according to JIS K6301. The breaking energy is 14355 (MP
a.%). Abrasion resistance is based on JIS K 6242
And Comparative Example 6 shown below as described above.
Is represented by an index with the value of 100 as 100.
The abrasion resistance in Example 8 was 100. The chip cut resistance was measured in the same manner as in the measurement method described in Example 1 described above, and the value in Comparative Example 6 shown below was set to 100
Expressed as an exponent. The chip cut resistance in Example 8 was 109.

Example 9 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 40 parts by weight of carbon black 2 and 20 parts by weight of carbon black 3
Parts by weight, 8 parts by weight of aromatic oil, 1 part of phenol-modified resin
Parts by weight, 2.6 parts by weight of sulfur, 0.7 parts by weight of a sulfenamide-based vulcanization accelerator, and 0.08 parts by weight of an aldehyde-ammonia-based vulcanization accelerator are mixed and vulcanized to obtain a rubber. A composition was obtained. In addition, each compound used had the same trade name as the compound used in Example 1 and Comparative Example 1 described above.

The tensile strength of the rubber composition was determined according to JIS K63.
It was 26.4 MPa when measured at 01. The elongation of the rubber composition was 490% as measured by JIS K6301. The hardness of the rubber composition was 68 as measured by a spring hardness test according to JIS K6301. The breaking energy is 12936 (MP
a.%). Abrasion resistance is based on JIS K 6242
And Comparative Example 6 shown below as described above.
Is represented by an index with the value of 100 as 100.
The wear resistance in Example 8 was 110. The chip cut resistance was measured in the same manner as in the measurement method described in Example 1 described above, and the value in Comparative Example 6 shown below was set to 100
Expressed as an exponent. The chip cut resistance in Example 8 was 102.

Comparative Example 6 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 50 parts by weight of carbon black 2, 4 parts by weight of aromatic oil, and 1 part by weight of phenol-modified resin Parts, 2.1 parts by weight of sulfur, 1.2 parts by weight of a sulfenamide-based vulcanization accelerator, and 0.08 parts by weight of an aldehyde-ammonia-based vulcanization accelerator, and vulcanization. I got something. In addition,
Each formulation used had the same trade name as the formulation used in Example 1 described above.

The tensile strength of the rubber composition was determined according to JIS K63.
It was 24.7 MPa when measured at 01. The elongation of the rubber composition was 470% as measured by JIS K6301. The hardness of the rubber composition was 68 as measured by a spring hardness test according to JIS K6301. The breaking energy is 11609 (MP
a.%). Abrasion resistance is based on JIS K 6242
And the value in Comparative Example 6 was set to 100 as described above. The chip-cut resistance was measured in the same manner as in the measurement method described in Example 1 described above, and the value in Comparative Example 6 was set to 100.

Comparative Example 7 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 60 parts by weight of carbon black 2, 4 parts by weight of aromatic oil, and 1 part by weight of phenol-modified resin Parts, 2.6 parts by weight of sulfur, 0.7 parts by weight of a sulfenamide-based vulcanization accelerator, and 0.08 parts by weight of an aldehyde-ammonia-based vulcanization accelerator, and vulcanization. I got something. In addition,
Each formulation used had the same trade name as the formulation used in Example 1 described above.

The tensile strength of the rubber composition was determined according to JIS K63.
01, it was 25.6 MPa. The elongation of the rubber composition was 440% as measured by JIS K6301. The hardness of the rubber composition was 71 as measured by a spring hardness test according to JIS K6301. The breaking energy is 11264 (MP
a.%). Abrasion resistance is based on JIS K 6242
, And as described above, the value is represented by an index with the value in Comparative Example 6 being 100. The wear resistance in Comparative Example 7 was 123. The chip-cut resistance is measured in the same manner as in the measurement method described in Example 1 described above, and is represented by an index with the value in Comparative Example 6 being 100. The chip cut resistance in Comparative Example 7 was 94.

Comparative Example 8 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 70 parts by weight of carbon black 2, 4 parts by weight of aromatic oil, and 1 part by weight of phenol-modified resin Parts, 2.6 parts by weight of sulfur, 0.7 parts by weight of a sulfenamide-based vulcanization accelerator, and 0.08 parts by weight of an aldehyde-ammonia-based vulcanization accelerator, and vulcanization. I got something. In addition,
Each formulation used had the same trade name as the formulation used in Example 1 described above.

The tensile strength of the rubber composition was determined according to JIS K63.
01, it was 26.3 MPa. The elongation of the rubber composition was 390% as measured by JIS K6301. The hardness of the rubber composition was 75 as measured by a spring hardness test in JIS K6301. The breaking energy is 10257 (MP
a.%). Abrasion resistance is based on JIS K 6242
, And as described above, the value is represented by an index with the value in Comparative Example 6 being 100. The wear resistance in Comparative Example 8 was 145. The chip-cut resistance is measured in the same manner as in the measurement method described in Example 1 described above, and is represented by an index with the value in Comparative Example 6 being 100. The chip-cut resistance in Comparative Example 8 was 90.

Comparative Example 9 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 80 parts by weight of carbon black 2, 4 parts by weight of aromatic oil, and 1 part by weight of phenol-modified resin Parts, 2.6 parts by weight of sulfur, 0.7 parts by weight of a sulfenamide-based vulcanization accelerator, and 0.08 parts by weight of an aldehyde-ammonia-based vulcanization accelerator, and vulcanization. I got something. In addition,
Each formulation used had the same trade name as the formulation used in Example 1 described above.

The tensile strength of the rubber composition was determined according to JIS K63.
It was 25.2 MPa when measured at 01. The elongation of the rubber composition was 280% as measured by JIS K6301. The hardness of the rubber composition was 78 as measured by a spring hardness test according to JIS K6301. The breaking energy is 7056 (MPa)
·%)Met. The abrasion resistance is measured according to JIS K 6242, and expressed as an index with the value in Comparative Example 6 being 100 as described above. The wear resistance in Comparative Example 9 was 130. Chip-cut resistance is
The measurement is performed in the same manner as in the measurement method described in Example 1 described above, and is represented by an index with the value in Comparative Example 6 being 100. The chip-cut resistance in Comparative Example 9 was 86.

Comparative Example 10 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 50 parts by weight of carbon black 2, 10 parts by weight of aromatic oil,
2.6 parts by weight of sulfur and 0.7 parts by weight of a sulfenamide-based vulcanization accelerator were mixed and vulcanized to obtain a rubber composition. Each of the compounds used had the same trade name as the compound used in Example 1 described above.

The tensile strength of the rubber composition was determined according to JIS K63.
01, it was 25.6 MPa. The elongation of the rubber composition was 580% as measured by JIS K6301. The hardness of the rubber composition was 62 as measured by a spring hardness test according to JIS K6301. The breaking energy is 14848 (MP
a.%). Abrasion resistance is based on JIS K 6242
, And as described above, the value is represented by an index with the value in Comparative Example 6 being 100. Comparative Example 10
Was 90. The chip-cut resistance is measured in the same manner as in the measurement method described in Example 1 described above, and is represented by an index with the value in Comparative Example 6 being 100. The chip-cut resistance in Comparative Example 10 was 116.

(Comparative Example 11) 70 parts by weight of NR (natural rubber), 30 parts by weight of BR (polybutadiene rubber), 50 parts by weight of carbon black 2, 12 parts by weight of aromatic oil,
2.6 parts by weight of sulfur and 0.7 parts by weight of a sulfenamide-based vulcanization accelerator were mixed and vulcanized to obtain a rubber composition. Each of the compounds used had the same trade name as the compound used in Example 1 described above.

The tensile strength of the rubber composition was determined according to JIS K63.
01, it was 25.3 MPa. The elongation of the rubber composition was 590% as measured by JIS K6301. The hardness of the rubber composition was 61 as measured by a spring hardness test according to JIS K6301. The breaking energy is 14927 (MP
a.%). Abrasion resistance is based on JIS K 6242
, And as described above, the value is represented by an index with the value in Comparative Example 6 being 100. Comparative Example 11
Was 83 in abrasion resistance. The chip-cut resistance is measured in the same manner as in the measurement method described in Example 1 described above, and is represented by an index with the value in Comparative Example 6 being 100. The chip cut resistance in Comparative Example 11 was 120.

The above Examples 5 to 9 and Comparative Examples 6-1
The results of No. 1 are shown in Table 2 below. It is understood that the rubber compositions according to Examples 5 to 9 show good values in both wear resistance and chip-cut resistance. On the other hand, in Comparative Examples 6 to 11, either the wear resistance or the chip cut resistance is insufficient. Or, it is understood that Comparative Examples 6 to 11 show insufficient values in any of the wear resistance and the chip cut resistance.

[0101]

[Table 2]

The embodiments and examples disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0103]

According to the present invention, a rubber composition having excellent abrasion resistance and chip-cut resistance can be obtained. Solid tires using the rubber composition according to the present invention, as compared with the conventional, can reduce abrasion and chip cutting properties that occur when used under high load conditions,
It was possible to prevent a decrease in tire life. Solid tires using the rubber composition according to the present invention can be particularly suitably used for tires used in industrial vehicles such as forklifts, and can be used at the same level as in normal use even under high load. Since it is possible, a remarkable effect can be obtained in both workability and economy.

Claims (4)

[Claims] The tensile strength (T _B ) according to JIS K 6301 is 22.0 MPa or more and the JIS K 6301
The elongation (E _B ) in K 6301 is 300% or more, the hardness in JIS K 6301 is 75 or more, and the tensile strength (T _B ) × the elongation (E _B ) is 700.
A rubber composition having 0 or more. 2. Tensile strength (T _B ) according to JIS K 6301 is 25.0 MPa or more and JIS K 6301
The elongation (E _B ) in K 6301 is 500% or more, and the hardness in JIS K 6301 is 63 or more 7
6 or less, and the tensile strength (T _B ) × the elongation (E _B ) is 120 or less.
A rubber composition of not less than 00. 3. A solid tire using the rubber composition according to claim 1 for a tread rubber. 4. A solid tire using the rubber composition according to claim 2 for a tread rubber.