JP2002284931A - Rubber composition for footgear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition which has excellent processability at unvulcanized state, has excellent wet skid resistance and excellent abrasion resistance, and is suitable for footgear. SOLUTION: This rubber composition for footgear is characterized by comprising (A) 100 pts.wt. of a conjugated dienic rubbery polymer or a conjugated diene-styrene-based rubbery copolymer, which contains (1) >60 wt.% of a modified polymer obtained by reacting the rubbery polymer with a multi-functional compound having two or more epoxy groups in the molecule, and has (2) a polymer mol.wt. distribution Mw/Mn of 1.05 to 3.0 and (3) a polymer weight- average mol.wt. of 100,000 to 2,000,000, and (B) 5 to 150 pts.wt. of a filler.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition for footwear, and more particularly to a rubber composition for footwear which is excellent in processability when not vulcanized and physical properties of a vulcanized product.

[0002]

2. Description of the Related Art Conventionally, rubber or elastomer has been used in various fields as a material for footwear. These processed products exhibit the original properties of rubber or elastomer, and have rubber or elastomer as a main component, and various fillers, in order to impart or improve various properties required according to the application. A rubber composition containing an additive, a colorant, a reinforcing agent and the like is used as a raw material. Generally, rubber or elastomer alone does not provide sufficient reinforcement, and therefore carbon black is blended as a filler. However, when the required rubber product is other than black, silica or the like may be blended instead of carbon black. However, rubber compositions using silica as a reinforcing filler have some problems to be solved. For example, silica has a lower affinity for rubber than conventional carbon black, so dispersibility in rubber is not always good, and poor dispersibility tends to cause insufficient wear resistance and insufficient strength characteristics. is there. In order to improve the dispersibility of silica, kneading is performed under specific temperature conditions using a silane coupling agent represented by bis- (triethoxysilylpropyl) -tetrasulfide, and the number of kneading is further increased to disperse the silica. Need to be improved.

[0003]

In footwear such as shoes and sandals, in order to obtain good comfort and safety, an outsole (sole) which is the bottom of the footwear has an excellent anti-slip property against the scaffold. It is required that the vulcanizates have excellent abrasion resistance in a portion having a (gripability) and being exposed to intense abrasion at the bottom of the footwear. The purpose of the present invention is
In particular, it is an object of the present invention to provide a rubber composition having excellent characteristics required for a rubber composition for footwear containing silica.

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have made intensive studies on a rubber composition containing a filler such as silica, and have found that a polymer having a specific structure is used. It has been found that the object can be achieved by the present invention, and the present invention has been completed. That is, the present invention relates to (A) a conjugated diene-based rubber-like polymer or a conjugated diene-styrene-based rubber-like copolymer, wherein (1) the rubber-like polymer and two or more epoxy groups in a molecule. (2) having a molecular weight distribution Mw / Mn of 1.05 to 3.0, and (3) a modified polymer obtained by reacting a polyfunctional compound having the following formula: The weight average molecular weight of the polymer is 1
It is intended to provide a rubber composition for footwear, comprising 100 parts by weight of a diene-based rubbery polymer having a molecular weight of from 0.00000 to 2,000,000 and 5 to 150 parts by weight of a filler (B).

The present invention is basically a rubber composition for footwear comprising (A) a modified conjugated diene-based polymer and (B) a filler as essential components. The modified conjugated diene-based polymer (A) having a specific structure of the present invention comprises at least one conjugated diene-based monomer or at least one conjugated diene-based monomer and an aromatic vinyl monomer. A conjugated diene-based rubbery polymer or a conjugated diene-aromatic polymer containing more than 60% by weight of a modified component (modified polymer) obtained by reacting with a specific modifier after solution polymerization in the presence of a lithium catalyst. It is an aromatic vinyl group copolymer.

In the present invention, examples of the conjugated diene-based monomer used for producing the conjugated diene-based rubbery polymer or the conjugated diene-aromatic vinyl-based rubbery copolymer include:
1,3-butadiene, isoprene, 2,3-dimethyl-
1,3-butadiene, 1,3-pentadiene, 3-methyl-1,3-pentadiene, 1,3-heptadiene,
1,3-hexadiene and the like are used, and one kind or a combination of two or more kinds is used. Preferred monomers include
Examples thereof include 1,3-butadiene and isoprene. Also,
Examples of the aromatic vinyl monomer include styrene, p-methylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, diphenylethylene, and the like, and may be used alone or in combination of two or more. . Preferred monomers include styrene.

In the case of a copolymer comprising a conjugated diene and a monomer copolymerizable therewith, the content of the copolymerizable monomer or the chain distribution of the copolymerizable monomer in the copolymer chain. Is not particularly limited. In addition, the composition distribution of the monomer capable of being copolymerized with the conjugated diene in the copolymer chain may be uniform in the molecular chain, or may be unevenly distributed in the molecular chain, It may exist as a block. In this method for producing a rubbery polymer, the hydrocarbon solvent is a saturated hydrocarbon or an aromatic hydrocarbon, such as an aliphatic hydrocarbon such as butane, pentane, hexane, pentane or heptane, cyclopentane, cyclohexane or methylcyclohexane. Alicyclic hydrocarbons such as pentane and methylcyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, and hydrocarbons composed of mixtures thereof are used. As the polymerization initiator, an anionic polymerization initiator is used, and an organic alkali metal compound and an organic alkaline earth metal are preferable, and an organic lithium compound is particularly preferable.

The organolithium compound includes all organolithium initiators capable of initiating polymerization, including those having a low molecular weight, solubilized oligomeric organolithium compounds, those having a single lithium in one molecule, 1
Examples include those having a plurality of lithium atoms in the molecule, those having a carbon-lithium bond, those having a nitrogen-lithium bond, those having a tin-lithium bond, and the like in the bonding manner between an organic group and lithium. Specifically, n-butyl lithium, sec-butyl lithium, t-butyl lithium, n-hexyl lithium,
Benzyllithium, phenyllithium, stilbenelithium, 1,4-dilithiobutane as a polyfunctional organic lithium compound, a reaction product of sec-butyllithium and diisopropenylbenzene, 1,3,5-trilithiobenzene,
Reactants of n-butyllithium with 1,3-butadiene and divinylbenzene, reactants of n-butyllithium with polyacetylene compounds, dimethylaminolithium, dihexylaminolithium, hexamethyleneiminolithium, etc. as compounds comprising nitrogen-lithium bonds can give. Particularly preferred are n-butyllithium, sec.
-Butyllithium. These organolithium compounds are used not only as one kind but also as a mixture of two or more kinds. In the polymerization reaction, diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran,
It is also possible to add an aprotic polar compound such as ethers such as 2,2-bis (2-oxolanyl) propane and amines such as triethylamine and tetramethylethylenediamine.

[0009] The polymerization reaction is carried out under the conditions usually carried out, for example, at a polymerization temperature of 20 to 150 ° C and a final polymer concentration of 5 to 30% by weight.
Taking into account that the polymerization is an exothermic reaction, it is controlled by the monomer and solvent feed temperature, monomer concentration and cooling or heating from outside the reactor. The rubbery polymer used in the present invention is a diene polymer having an active terminal,
It is necessary to contain more than 60% by weight of a modified component obtained by reacting a polyfunctional compound having two or more epoxy groups in a molecule.

In order to industrially obtain a rubbery polymer having a high modification rate used in the present invention, it is necessary to efficiently obtain a diene polymer having an active terminal before the modification reaction by a controlled method. Normally, industrially available monomers, solvents, etc. contain various harmful impurities, which react with the active terminal of the polymer during polymerization to cause a termination reaction, a transfer reaction, and a polymerization reaction of the polymer. The number of active ends is reduced, and the modified component of the present invention is added to 6
It is difficult to obtain a polymer containing more than 0% by weight. In particular, when polymerizing at a high temperature exceeding 80 ° C., the influence of impurities such as alkenes, acetylenes, and water is large. In order to obtain a diene polymer having a structure limited by the present invention, it is necessary to feed a monomer and a solvent having a small amount of impurities to a polymerization reactor and to control the polymerization temperature.

In the present invention, all impurities in the monomer and the solvent fed to the polymerization reactor are less than 0.40 equivalents relative to the initiator fed to the polymerization reactor.
Preferably it should be no more than 0.30 equivalents. Specifically, as impurities in the conjugated diene monomer, for example, compounds reacting with a plurality of moles of an organic alkali metal such as vinyl acetylene, 1,2-butadiene, and butyne-1, and equimolar to an organic alkali metal such as an aldehyde Compounds which react, and impurities in the styrene monomer include, for example, compounds which react equimolarly with organic alkali metals such as phenylacetylene and benzaldehyde, and TBC such as a polymerization inhibitor TBC which is common to various monomers and solvents. There are compounds that react with 2 moles of the organic alkali metal and compounds that react equimolarly with the organic alkali metal such as water. In the present invention, it is preferable that the calculation is performed on the assumption that a compound reacting in a plurality of moles reacts in two moles.

As a method of reducing the influence of these impurities,
Naturally, it is preferable to use a raw material having a small amount of impurities. However, in practice, it is common to use a raw material containing impurities and remove it by a chemical engineering method such as distillation or adsorption. However, these methods are not effective enough,
In order to obtain a sufficient effect, a large cost is required economically. Therefore, in the present invention, since a small amount of impurities is greatly affected due to a high molecular weight, as a method of reducing the influence of impurities more than usual, preferably before the monomer and the solvent fed to the polymerization reactor are fed. In addition, a method in which an organic metal compound in an amount corresponding to an impurity, specifically, a polymerization catalyst or the like is reacted in advance to substantially inactivate it is preferable. These methods alone or in combination greatly reduce the deactivation of active ends during polymerization by impurities contained in the monomer solution fed to the polymerization reactor, resulting in temperatures above 80 ° C. Preferably, the denaturation reaction can be carried out industrially efficiently at a temperature of 120 ° C. or lower.

As the modifier used to obtain the modified conjugated diene polymer (component A) of the present invention, a polyfunctional compound having two or more epoxy groups in a molecule is used.
Any compound can be used as the polyfunctional compound having two or more epoxy groups in the molecule. Specifically, polyglycidyl ethers of polyhydric alcohols such as ethylene glycol diglycidyl ether and glycerin triglycidyl ether; polyglycidyl ethers of aromatic compounds having two or more phenol groups such as diglycidylated bisphenol A; -Diglycidylbenzene, 1,3
Polyepoxy compounds such as 5-triglycidylbenzene and polyepoxidized liquid polybutadiene; tertiary amines containing epoxy groups such as 4,4'-diglycidyl-diphenylmethylamine and 4,4'-diglycidyl-dibenzylmethylamine; diglycidyl Diglycidylamino compounds such as aniline, diglycidyl orthotoluidine, tetraglycidylmethaxylenediamine, tetraglycidylaminodiphenylmethane, tetraglycidyl-p-phenylenediamine, diglycidylaminomethylcyclohexane, and tetraglycidyl-1,3-bisaminomethylcyclohexane can give. Preferably, a polyfunctional compound having two or more epoxy groups and one or more nitrogen-containing groups in the molecule is used. More preferably, a polyfunctional compound of the following general formula is used.

[0014]

Embedded image (However, R ¹ and R ² are a hydrocarbon group or ether having 1 to 10 carbon atoms and / or a hydrocarbon group having 1 to 10 carbon atoms having a tertiary amine; R ³ and R ⁴ are hydrogen and 1 carbon atoms. A hydrocarbon group or ether having from 1 to 20 carbon atoms and / or a hydrocarbon group having 1 to 20 carbon atoms having a tertiary amine, R
⁵ is a hydrocarbon group having 1 to 20 carbon atoms or a hydrocarbon group having 1 to 20 carbon atoms having at least one group among ether, tertiary amine, epoxy, carbonyl and halogen. It is an integer. )

[0015] More preferably, it is a polyfunctional compound having a diglycidylamino group. Further, the number of epoxy groups in the molecule needs to be two or more, more preferably three or more, and still more preferably four or more. However, in these compounds, a functional group that reacts with the active terminal of the polymer to inactivate the active terminal, for example, a functional group having active hydrogen, such as a hydroxyl group, a carboxyl group,
Compounds having a primary or secondary amino group or the like in the molecule, and polyfunctional compounds having a functional group capable of releasing alcohol or amine, for example, ether or amide, in the molecule are not preferred. On the other hand, there may be a functional group which reacts with and binds to the active terminal of the polymer, such as carbonyl and halogen.

The polyfunctional compound having two or more epoxy groups in these molecules, preferably, the epoxy group of the polyfunctional compound exceeds 0.6 equivalent relative to the active terminal of the polymer,
The molecules of the polyfunctional compound are reacted at a molar ratio of 10 times or less with respect to the active terminal of the polymer. In the case of the active terminal of a polymer polymerized with a monofunctional initiator, below this, the modified component of the present invention does not contain more than 60% by weight. On the other hand, if it exceeds this, the number of unreacted polyfunctional compounds having an epoxy group increases, and the performance is rather deteriorated.

When the active terminal of the polymer reacts with the epoxy group, a hydroxyl group is introduced into the polymer chain. When the epoxy group of the polyfunctional compound is more than 0.6 equivalent and not more than 1 equivalent based on the active terminal of the polymer, the active terminal of most of the polymer reacts with the epoxy group of the polyfunctional compound to form a plurality of molecules. The coupling reaction produces a modified polymer molecule having a plurality of hydroxyl groups. When the epoxy group of the polyfunctional compound exceeds 1 equivalent relative to the active terminal of the polymer, the polymer molecule having a plurality of hydroxyl groups is bonded to the polymer together with the hydroxyl group generated by the reaction between the active terminal of the polymer and the epoxy group. Both modified polymer molecules in which both unreacted epoxy groups are present in the resulting polyfunctional compound molecule are formed. When a polyfunctional compound having two or more epoxy groups and one or more nitrogen-containing groups in the molecule is used, a nitrogen-containing group is introduced together with a hydroxyl group generated by the reaction between the active terminal of the polymer and the epoxy group. .

The specific rubbery polymer used in the present invention is required to have a polyfunctional compound-modified component content of more than 60% by weight of the whole polymer. Preferably, 7
0% by weight or more. When the content of the modifying component is large, the effect of the filler with silica is more exhibited. The content of the denatured component can be measured by chromatography capable of separating the denatured component and the non-denatured component. As a method of this chromatography, a method of using a GPC column filled with a polar substance such as silica that adsorbs denatured components and using an internal standard for non-adsorbed components,
There is a method in which GPC of the polymer before modification and the polymer after modification are measured, and the amount of the modified portion is calculated based on changes in the shape and molecular weight. The molecular weight distribution Mw / Mn of the rubbery polymer (A) used in the present invention is in the range of 1.05 to 3.0. The molecular weight distribution is determined by using GPC and measuring from the molecular weight of standard polystyrene. When the molecular weight distribution is less than 1.05, processability is poor, and it is difficult to produce industrially. When it exceeds 3.0, the mechanical strength of the obtained rubber composition is inferior.

A polymer having a molecular weight distribution of 2.2 or more has advantages such as excellent workability during kneading, a small torque during processing, and a short kneading time. on the other hand,
When the molecular weight distribution is less than 2.2, the processability is generally poor, and particularly in the case of compounding silica, the torque at the time of processing becomes large. Therefore, conventionally, it was necessary to use a large amount of carbon black in combination. In the case of the present invention, the processability is excellent even when the compounding amount of carbon black is small because the affinity for silica is increased, and the wet skid resistance (slip resistance, grip) of the obtained rubber composition is further improved. sex)
And the strength properties are also better. The weight average molecular weight of the rubbery polymer (A) of the present invention is 100,00
It must be between 0 and 2,000,000. The weight average molecular weight is determined by using GPC and measuring from the molecular weight of standard polystyrene. Weight average molecular weight is 1
If it is less than 00,000, the strength and abrasion resistance of the obtained rubber composition are reduced, and if it is more than 2,000,000, the processability is extremely reduced and it becomes difficult to obtain the rubber composition.

The rubbery polymer (A) of the present invention preferably has a Mooney viscosity in the range of 20 to 200. The Mooney viscosity was measured using a Mooney viscometer specified in the standard specification at a temperature of 100 ° C. (ML1 + 4
(100 ° C.)). However, the value of Mooney viscosity is about 150
If it is difficult to measure at 100 ° C exceeding
Measure at a temperature of 30 ° C. and convert to a value at 100 ° C. When the Mooney viscosity is less than 20, the strength and abrasion resistance of the obtained rubber composition are reduced, and when it exceeds 200, the processing performance is extremely reduced and it becomes difficult to obtain the rubber composition. The Mooney viscosity is more preferably in the range of 25 to 180. The rubbery polymer of (A) of the present invention is put into practical use as an oil-extended rubber obtained by adding 20 to 60 parts by weight of a normal rubber extender oil per 100 parts by weight of rubber in order to make the processing easier. Is also possible.

The glass transition temperature of the rubbery polymer (A) of the present invention is preferably in the range of -100 to 0 ° C. so that the finally obtained rubber composition exhibits rubber elasticity. Furthermore,-
The range of 95 to -10C is more preferable. The range of the glass transition temperature of the rubbery polymer used in the present invention is selected according to the intended use of the rubber composition.For example, a rubbery polymer having a low range of the glass transition temperature in applications where low-temperature performance is more important Is mainly selected, and in applications where a braking ability is required, a rubbery polymer having a glass transition temperature in a high range is mainly selected. The glass transition temperature is controlled by the composition of the constituent conjugated diene and styrene, and when the conjugated diene is butadiene or isoprene, the microstructure in the polymer chain (1,4-bond and 1,2- and 3,4- (Combination) ratio. When the rubber-like polymer of the present invention is polybutadiene, the 1,2-bond amount of the micro bond of butadiene is preferably from 10 to 80%. When the rubber-like polymer of the present invention is a styrene-butadiene copolymer, It is preferable that the amount of styrene is 5 to 45%, and the amount of 1,2-bond in the micro bond of the butadiene portion is in the range of 10 to 70%. The rubbery polymer as the component (A) of the present invention may be not only one kind but also, for example, two or more kinds of rubbery polymers. In that case, styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (B
R), NR, NBR, polyisoprene rubber (IR), polychloroprene rubber (CR), ethylene-propylene copolymer rubber (EPM, EPDM) and the like are used.

In the rubber composition of the present invention, the mixing ratio of (A) the modified conjugated diene polymer and (B) the filler is as follows:
The proportion of the filler (B) is 5 to 150 parts by weight based on 100 parts by weight of the modified conjugated diene-based polymer (A), and preferably (B) is based on 100 parts by weight of the modified conjugated diene-based polymer (A). The ratio of the filler is 10 to 100 parts by weight. (A)
With respect to 100 parts by weight of the modified conjugated diene polymer, (B)
If the compounding ratio of the filler is less than 5 parts by weight, no compounding effect can be obtained, and if it exceeds 150 parts by weight, processability is impaired. Further, in the rubber composition of the present invention,
The filler as the component (B) includes general inorganic fillers (for example, calcium carbonate, clay, talc, diatomaceous earth, mica, alumina, aluminum sulfate, barium sulfate, calcium sulfate, etc.), and furthermore. , Carbon black, silica and the like. In the present invention, one or a combination of two or more of these may be used as the filler.

Among these, silica is particularly poor in mixing processability, and the effect of the present invention is remarkable. As the silica to be used, any of wet-process silica, dry-process silica, and synthetic silicate-based silica can be used. Silica having a small particle diameter has a high reinforcing effect and a high effect of improving grip performance, and a small particle diameter and high aggregation type is preferable. Silica is used as a filler having a reinforcing effect in an amount of 5 to 150 parts by weight per 100 parts by weight of the raw rubber. 5
If the amount is less than 150 parts by weight, the strength and other physical properties are inferior. Silica amount is 25-100
Parts by weight are preferred. Next, when silica is used as the filler, an organic silane coupling agent can be used. The organic silane coupling agent is preferably added in an amount of 0.1 to 20% by weight of silica in order to make the coupling action (interaction) between the silica filler and the raw rubber tight. When the amount of the organic silane coupling agent is 20
When the amount is more than the weight part, the reinforcing property is impaired. The amount of the organic silane coupling agent is more preferably in the range of 0.1% by weight or more and 6% by weight or less of the amount of the reinforcing silica filler.

The organic silane coupling agent has an affinity or a bonding group in the molecule for the double bond of the polymer and the surface of the silica, respectively. An example is bis- [3- (triethoxysilyl) -propyl]-
Tetrasulfide, bis- [3- (triethoxysilyl) -propyl] -disulfide, bis- [2- (triethoxysilyl) -ethyl] -tetrasulfide, 3-
Mercaptopropyl-trimethoxysilane, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide and the like. In the present invention, since the rubbery polymer having a specific modifying component has a high binding performance with reinforcing silica, it does not use an organic silane coupling agent or has a silane as compared to the case where another polymer is used. Instead of reducing the amount of the coupling agent, it is possible to obtain a high-performance rubber composition.

The rubber composition of the present invention is compounded as necessary to further improve the properties such as the modified conjugated diene polymer (A), the filler (B) and the abrasion resistance. In addition to the silane coupling agents used, vulcanizing or cross-linking agents, vulcanizing or cross-linking accelerators, various oils, anti-aging agents, plasticizers, anti-scorch agents, flame retardants, etc. Various additives that have been blended can be blended. These additives can be blended in conventional general amounts of these additives, as long as they do not contradict the purpose of the present invention.

The production of the rubber composition for footwear of the present invention is carried out by subjecting the modified conjugated diene polymer of the above-mentioned component (A) to (B)
The filler used for the component and the silane coupling agent to be blended if necessary, and the above-mentioned various additives are added, and a method used in the production of a normal rubber composition, for example, a Banbury mixer, a heating roll, various kneaders The components can be uniformly kneaded using a melt kneader such as a single-screw extruder or a twin-screw extruder and vulcanized or cross-linked, and the production method is not limited. The rubber composition for footwear of the present invention frequently becomes wet with water such as trekking shoes, fishing boots, diving shoes, motorcycle shoes, bath shoes, rain shoes, beach sandals and the like used on rocky places. It is suitable for the outsole of shoes used on a scaffold. Of course, it can be used for shoes other than these.

[0027]

The characteristics of the composition of the present invention will be described in more detail with reference to the following examples. (Synthesis of raw rubber) Production method of SBR-1: an internal volume of 10 liters, an inlet at the bottom and an outlet at the head, two autoclaves equipped with a stirrer and a jacket were connected in series as reactors, and butadiene was After mixing 16.38 g / min, styrene at 8.82 g / min, and n-hexane at 132.3 g / min, the mixed solution was passed through a dehydration column filled with activated alumina to remove impurities. After mixing n-butyllithium in a static mixer at a rate of 0.0046 g / min, it was continuously supplied from the bottom of the first reactor using a metering pump, and furthermore, 2,2-bis ( 2-oxolanyl) propane in 0.0
Feeding n-butyllithium as a polymerization initiator at a rate of 0.0070 g / min directly to the reactor at a rate of 28 g / min,
The reactor internal temperature was maintained at 86 ° C. The polymer solution was continuously withdrawn from the reactor head and supplied to the second reactor. 1
After the state of the base reactor was stabilized, the Mooney viscosity of the resulting polymer before the modification reaction was 55 as measured at 100 ° C. The temperature of the second reactor was kept at 80 ° C., and 0.009 g / min of tetraglycidyl-1,3-bisaminomethylcyclohexane (equivalent ratio to active lithium = 0.09 g / min).
It was added from the bottom of the reactor at the rate of 9) to cause a denaturation reaction.
An antioxidant was continuously added to the polymer solution to terminate the modification reaction, and then the solvent was removed to obtain a sample A having a desired modified component. Further, a sample B having a different structure was obtained by the same continuous polymerization method as that for obtaining the sample A.

Table 1 shows the analysis values of the above samples. SBR production method-2: 645 g of butadiene, 280 g of styrene, and 55 g of cyclohexane were used as reactors, using a temperature-controllable autoclave equipped with a stirrer and a jacket and having an internal volume of 10 liters.
To the reactor, 00 g and 0.70 g of 2,2-bis (2-oxolanyl) propane as a polar substance were charged, and the temperature inside the reactor was maintained at 30 ° C. A cyclohexane solution containing 0.85 g of n-butyllithium as a polymerization initiator was supplied to the reactor. After the start of the reaction, the sound in the reactor gradually increased due to the heat generated by the polymerization. 7 to 5 minutes after addition of polymerization initiator
Over a minute period, 75 g of butadiene was fed at a rate of 15 g / min. The final reactor temperature reached 75 ° C. After the completion of the polymerization reaction, a part of the polymer solution was collected. The Mooney viscosity of the polymer before the modification reaction measured after removing the solvent is 10
It was 7 when measured at 0 ° C. 1.2 g of tetraglycidyl-1,3-bisaminomethylcyclohexane was added as a denaturant to the reactor, and the mixture was kept at 75 ° C. for 5 minutes to carry out a denaturation reaction. After adding an antioxidant to this polymer solution, the solvent was removed to obtain a styrene-butadiene copolymer having a modified component (Sample C). Further, Samples D and E were prepared in the same manner as Sample C was obtained. Table 1 shows the analysis values of the above samples.

The analysis of the sample was performed by the following method. 1) Amount of bound styrene A sample was prepared as a chloroform solution, and the amount of bound styrene [S] was determined by the absorption of UV at 254 nm by the phenyl group of styrene.
(Wt%) was measured. 2) Microstructure of butadiene portion The sample was prepared as a carbon disulfide solution, the infrared spectrum was measured in the range of 600 to 1000 cm ^-1 using a solution cell, and the microstructure of the butadiene portion was calculated from the predetermined absorbance according to the Hampton formula. I asked. 3) Mooney viscosity According to JIS K 6300, 4 minutes at 100 ° C and 1 minute of preheating.
Measure the viscosity after one minute.

4) Molecular weight and molecular weight distribution A chromatogram is measured using GPC using three columns connected with a polystyrene-based gel as a packing material, and the molecular weight and molecular weight distribution are calculated from a calibration curve using standard polystyrene. . 5) Modification ratio The property of adsorbing the denatured component is applied to a GPC column using silica gel as a filler, and the polystyrene gel (4) manufactured by Showa Denko KK is used for the sample and the sample solution containing low-molecular-weight internal standard polystyrene. : Shodex) GPC
And silica column GPC (Zorba manufactured by DuPont)
Both chromatograms of x) were measured, and the amount of adsorption on the silica column was measured from the difference between them to determine the denaturation rate (% by weight).

6) Formulation Mooney Viscosity Using a Mooney viscometer, measure the viscosity after 1 minute of preheating and 4 minutes of 2 rotations at 130 ° C. according to JIS K 6300. If the Mooney viscosity greatly exceeds 80, the processability is poor. When the Mooney viscosity is 30 or less, the adhesion becomes large and processing becomes difficult. 7) 300% modulus and tensile strength Measured by a tensile test method of JIS K6251. 8) Wet skid resistance performance (anti-slip property, grip property) Tested with Tan δ at 0 ° C. Rheometrics
Measured by ARES viscoelasticity tester at a frequency of 10 Hz, strain of 3% and 0 ° C. by the torsion method The higher the number, the better the wet skid resistance performance.

9) Abrasion resistance index The abrasion loss of the sample was measured using an Akron-type tester, and the index determined by the following equation was determined as an index of abrasion resistance.
Index = [(abrasion loss of standard example) / (abrasion loss of sample)] × 100 (3) [Adjustment and measurement of rubber composition] In the present invention, the rubber compound is prepared according to the evaluation compound shown in Table 2. 1.7 l
ASTM-D-3403-7 using a test Banbury mixer and a 10 inch mixing roll for test.
Kneading was performed according to the mixing procedure of Method B of the standard mixing procedure shown in No. 5, and was molded into a predetermined shape, and then vulcanized at 145 ° C. for 35 minutes to obtain a rubber composition sample, and various physical properties were measured.

[0033]

Examples 1 to 6,

Comparative Example 1 A footwear composition having the composition shown in Table 2 was prepared.
A test piece was prepared by vulcanization at 160 ° C. for 20 minutes and a predetermined test was performed. Table 3 shows the results. From the results shown in Table 3, the footwear rubber compositions of Examples 1 to 5 using the modified styrene-butadiene copolymer defined in the present invention as the component (A) of the raw rubber had good processability and wet skid resistance. (Anti-slip, grip) and wear resistance,
The rubber composition of Comparative Example 1 using a rubbery polymer outside the range of the present invention as the component (A) of the raw rubber resulted in inferior wet skid resistance (slip resistance, grip properties) and abrasion resistance. .

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

As is clear from the above, the rubber composition of the present invention is excellent in workability in the unvulcanized state, and is excellent in wet skid resistance (slip resistance and grip properties) and abrasion resistance. It is a suitable rubber composition.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4F050 AA01 AA06 BA01 BA56 HA53 HA55 4J002 AC111 DA036 DE236 DG046 DG056 DJ006 DJ016 DJ036 DJ046 DJ056 FB096 FB156 FD016 GC00 4J100 AB00Q AB02Q AB03Q AB04Q AB13Q AS01 AS03BAH30P CA01 CA04 DA01 DA04 DA09 HA29 HA35 HA61 JA57

Claims (3)

[Claims] 1. A conjugated diene rubbery polymer or a conjugated diene-styrene rubbery copolymer,
(1) a modified polymer obtained by reacting the rubber-like polymer with a polyfunctional compound having two or more epoxy groups in a molecule in an amount exceeding 60% by weight; The molecular weight distribution Mw / Mn of the union is 1.05 to 3.0, (3)
The weight average molecular weight of the polymer is from 100,000 to 2,000.
100 parts by weight of a diene rubbery polymer having a molecular weight of 0.000,
(B) A rubber composition for footwear, comprising 5 to 150 parts by weight of a filler. 2. The rubber composition for footwear according to claim 1, wherein the polyfunctional compound having two or more epoxy groups in the molecule further has one or more nitrogen-containing groups. 3. The rubber composition according to claim 1, wherein the polyfunctional compound having two or more epoxy groups in the molecule is represented by the following general formula. Embedded image (However, R ¹ and R ² are a hydrocarbon group or ether having 1 to 10 carbon atoms and / or a hydrocarbon group having 1 to 10 carbon atoms having a tertiary amine; R ³ and R ⁴ are hydrogen and 1 carbon atoms. A hydrocarbon group or ether having from 1 to 20 carbon atoms and / or a hydrocarbon group having 1 to 20 carbon atoms having a tertiary amine, R
⁵ is a hydrocarbon group having 1 to 20 carbon atoms or a hydrocarbon group having 1 to 20 carbon atoms having at least one group among ether, tertiary amine, epoxy, carbonyl and halogen. It is an integer. )