JPH03281642A - Preparation of rubber composition and rubber composition prepared thereby - Google Patents

Abstract

PURPOSE:To improve the dispersion of carbon black, processability, and vulcanizate properties by mixing a latex or soln. of a rubber polymer with a carbon black in the presence of a specific compd. CONSTITUTION:100 pts.wt. (solid content) latex or soln. of a rubber polymer is mixed with 10-200 pts.wt. carbon black in the presence of a compd. having a group of the formula and including from a low-molecular wt. org. compd. through an oligomer to a high-molecular wt. polymer with a wt.-average mol.wt. of the order of 10<5> in an amt. of 0.01-50 pts.wt. (based on 100 pts.wt. carbon black), and then dried.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a rubber composition with improved processability and vulcanizable properties.

(Prior Art) The performance requirements for various rubber products containing carbon black are becoming higher and higher year by year. It is well known that properties such as tensile strength, impact resilience, and abrasion resistance of carbon black-containing rubber vulcanizates are significantly influenced by the quality of carbon black dispersion.

Normally, carbon blank and rubber are mixed using a mixer such as a Banbury or roll mill using a dry mix method, but the so-called weft carbon method is a method in which carbon blank is mixed with latex or solution rubber. A master bunch method (hereinafter sometimes referred to as WCMB method) is also used. The dispersibility of carbon is WC
Although the MB method is said to be better than the dry mix method, there is not much difference.

(Problems to be Solved by the Invention) As a result of intensive studies to develop a method for producing a rubber composition with improved carbon blank dispersibility, the present inventors found that by using a specific compound in the WCMB method, It has been surprisingly found that the dispersibility of the carbon blank is improved compared to the conventional WCMB method, and the processability of the rubber composition is also improved, and based on this knowledge, the present invention has been completed.

(Means for Solving the Problems) According to the present invention, when mixing rubbery polymer latex or solution with carbon black, a compound having a bond represented by >C=N (in the molecule) Provided is a method for producing a rubber composition, which comprises mixing in the presence of a rubber composition.

The rubber-like polymer used in the present invention is not particularly limited as long as it is a rubber-like polymer that can be made into a latex or a solution.
It is desirable to use a rubbery polymer obtained by conventional emulsion polymerization or solution polymerization techniques. Such polymers include one or more polymers and copolymers of conjugated dienes such as butadiene, isoprene, 2,3-dimethylbutadiene, 1°3-pentadiene, chlorobrene; Aromatic vinyl compounds such as styrene, α-methylstyrene, and vinyltoluene that can be copolymerized with this, unsaturated nitrile compounds such as acrylonitrile and methacrylonitrile, and unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid. Copolymerization with one or more esters of unsaturated carboxylic acids such as acid, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, maleic acid mono- or dimethyl ester methoxyethyl acrylate, ethoxyethyl acrylate, etc. Coalescing (e.g. polybutadiene, polyisoprene, styrene-butadiene copolymer rubber, styrene-isoprene copolymer rubber, acrylonitrile-butadiene copolymer rubber, acrylonitrile-isoprene copolymer rubber, etc.)
, various acrylic rubbers, natural rubber, etc.

The carbon blank (hereinafter sometimes referred to as CB) used in the present invention is not particularly limited, and may include various carbon blacks (FEF, GPF, etc.) conventionally used for reinforcement.
, MAF, HAF, ll5AF.

l5AF, SAF, CB with a smaller particle size than SAF, etc.) can be used.

■ The compound having a bond >C=N (in the molecule used in the present invention) is a polymer (oligomer with a weight average molecular weight of 10
' up to a high molecular weight of the order of magnitude). Low-molecular organic compounds having this bond include ethyllithium, n-propyllithium, n-butyllithium, 5ec-butyllithium, t-octyllithium, n-decyllithium,
Organolithium compounds such as phenyllithium, 2-naphthyllithium, 2-butyl-phenyllithium, cyclohexyltium, 4-cyclopentyllithium, 1,4-dilithio-butene-2, and alkali metal base materials such as sodium naphthalene and sodium biphenyl. a compound having at least one catalyst and atoms in the molecule (modifier I),
N-substituted amino (thio)ketone, N-substituted amino (
It is obtained by reacting a compound (modifier n) such as thio)aldehyde (hereinafter sometimes referred to as a modifier). Polymers having such bonds (including oligomers to high molecular weight polymers) are monomers that can be polymerized with alkali metal-based catalysts and/or alkaline earth metal-based catalysts, such as the above-mentioned conjugated dienes, aromatic The above metal is added to a living (co)polymer obtained by polymerizing or copolymerizing a group vinyl compound, etc., in which the above metal is bonded to the end of the molecular chain, or an unsaturated polymer having a carbon-carbon double bond. (For details, see JP-A-58-162604 and JP-A-60-137913).

Modifier 1 includes N-methyl-β-propiolactam, N-t-butyl-β-propiolactam, N-methoxyphenyl-β-propiolactam, and N-naphthyl-β-propiolactam.
-propiolactam, N) thyl-2-pyrrolidone, N-
Phenyl-pyrrolidone, N-methoxyphenyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-benzyl-2-pyrrolidone, N-naphthyl-2-pyrrolidone, N
-Methyl-5-methyl-2-pyrrolidone, N-t-butyl-5-methyl-2-pyrrolidone, N-phenyl-5-methyl-2-pyrrolidone, N-methyl-3,3°-dimethyl-2-pyrrolidone , N-t-butyl-3,3"-dimethyl-2-pyrrolidone, N-phenyl-3,3°-
Dimethyl-2-pyrrolidone, N-methyl-2-piperidone, N-t-butyl-2-pyrrolidone, N-phenyl-
2-piperidone, N-methoxyphenyl-2-piperidone, N-vinyl-2'-piperidone, N-benzyl-2
-piperidone, N-naphthyl-2-piperidone, N-methyl-3,3°-dimethyl-2-piperidone, N-phenyl-3,3°-dimethyl-2-pyrrolidone, N-
Methyl-C-caprolactam, N-phenyl-ε-caprolactam, N-methoxyphenyl-ε-caprolactam, N-vinyl-ε-caprolactam, N-benzyl-
ε-caprolactam, N-naphthyl-ε-caprolactam, N-methyl-ω-laurirolactam, N-phenyl-ω-laurirolactam, N-t-butyl-ω-laurirolactam, N-vinyl-ω- laurirolactam, N-
N-substituted lactams such as benzyl-ω-laurirolactam and their corresponding thiolactams IN; 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-
Imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, 1,3-dimethylethyleneurea, 1-3
Examples include N-substituted cyclic ureas such as diphenylethylene urea, 1,3-di-butylethylene-urea, and 1,3-divinylethylene urea, and corresponding N-substituted cyclic thioureas.

Modifiers (2) include 4-dimethylaminobenzophenone, 4-diethylaminobenzophenone, 4-di-t-butylaminobenzophenone, 4-diphenylbenzophenone, 4,4'-bis(dimethylamino)benzophenone, and 4,4'-bis (diethylamino)benzophenone, 4.4'-bis(di-t-butylamino)benzophenone, 4.4'-bis(di-t-phenylamino)benzophenone, 4.4'-bis(di-t-vinylamino) Benzophenone, 4-dimethylaminoacetophenone, 4
-N-substituted aminoketones such as diethylaminoacetophenone, 1,3-bis(diphenylamino)-2-propane, 1,7-bis(methylethylamino)-4-heptanone and corresponding N-substituted aminothioketones Illustrated.

The amount of the above-mentioned catalyst is usually in the range of 0.1 to 10 mmol per 100 g of the monomer or unsaturated polymer, and the amount of the modifier is in the range of 1 to 10 mmol per 100 g of the monomer or unsaturated polymer.
0.05 to 10 moles per mole, preferably 0.2 to 2 moles per mole. After completion of the reaction, a proton-donating compound such as water or alcohol is added to the reaction system and the reaction product is recovered. A compound (hereinafter sometimes referred to as an additive substance) having a bond represented by >C=N4 in the molecule used in (1) is obtained.

The wet carbon mask batch method (WCMB) using each component explained above will be explained below. The WCMB method of the present invention can be a conventional WCMB method, except that it is carried out in the presence of the above-mentioned specific compound. Carbon blank (CB) is mixed with a latex or solution of a rubbery polymer, and carbon black can also be mixed with a powder, such as TENX, but is usually prepared as a dispersion in water or an organic solvent. Mixed as a liquid.

The concentration of CB in the dispersion is usually 1 to 20% by weight. The method of using the additive substance is not particularly limited, but it is desirable to add a liquid dissolved or suspended in water or an organic solvent to the CB dispersion and mix it with the latex or the like. When the additive substance is used as a suspension, a dispersion agent such as a surfactant may be used as necessary. C.B.
The same applies when producing a dispersion of . The concentration of additives in the solution or suspension is usually between o,ooi and 5% by weight.

Organic solvents used to make CB dispersions, solutions or suspensions of additives include butane, pentane, 2-methylbutene, 1-methylbutene, hexane, heptane,
Examples include octane, methylcyclopentane, cyclohexane, benzene, xylene, styrene, and isoprene, and these may be used alone or in a mixture of two or more. Solvents other than these may also be used. When rubbery polymers are used as solutions, it is advantageous to use cements of these polymers obtained by solution polymerization. Further, when a rubbery polymer is used as the latex, it is preferable to use the polymer latex obtained by emulsion polymerization. The amount of carbon black used is 10 to 200 parts by weight per 100 parts by weight of rubber (solid content), and the amount of additives used is 0.0 parts by weight per 100 parts by weight of carbon black.
The amount is 1 to 50 parts by weight, preferably 0.1 to 30 parts by weight. Mixing of these components is usually carried out by stirring with an agitator or using a mixer such as a homogenizer or homodisper.

During mixing, aromatic or naphthenic process oils, anti-aging oils, etc. can be added as required.

After forming a homogeneous liquid mixture, the homogeneous mixture of the rubbery polymer, additives, and carbon black is recovered by a conventional coagulation method, and then subjected to a drying process to obtain the desired rubber composition.

As the coagulation method, a method of adding an inorganic salt such as MacI, CaClz, etc. and/or an acid such as hydrochloric acid or sulfuric acid, a coagulating agent such as a polymer flocculant, a steam stripping method, etc. are used.

Since the rubber composition thus obtained contains a carbon blank in the rubber component like the conventional WCMB, the time and power required for crosstalk are small. In addition, in the conventional WCMB, the final dispersibility of carbon black is only comparable to that in the tri-blend method.However, in the rubber composition of the present invention, an organic substance having a group represented by 〉C=N In order to improve the dispersibility of carbon black, it is ultimately possible to obtain a dispersibility of carbon black that is higher than that achieved by the triblend method, and as a result, rubber physical properties such as impact resilience are also improved.Furthermore, the rubber composition obtained by the present invention The rubber component is inexpensive because rubber obtained by emulsion polymerization, which is cheaper to produce than solution polymerization, can also be used.

When used, the rubber composition of the present invention is sulfur-vulcanized, consisting of sulfur, zinc white, stearic acid, vulcanization accelerators (guanidine-based, thiazole-based, thiuram-based, dithioate-based, etc.) commonly used in the rubber industry. system, or organic oxide system,
It is used as a compounded rubber composition that further contains various compounding agents such as processing oil, plasticizer, processing aid, anti-aging agent, etc.

Since the rubber composition of the present invention provides a vulcanizate with improved impact resilience, it is particularly suitable for trend tires such as automobile tires and motorcycle tires, and for carcass, but is not limited to these uses.

(Example) The present invention will be described in detail below with reference to Examples.

Examples 1 to 3 A stainless steel polymerization reactor with an internal volume of 21 cm was washed, dried,
After purging with dry nitrogen, 120 g of 1,3-butadiene
, 40 g of styrene, 840 g of cyclohexane, 0.5 mmol of tetramethylethylenediamine, and 0.4 mmol of n-butyllithium (n-hexane solution) were added, and the contents were polymerized at 45° C. for 5 hours while stirring. After the polymerization reaction was completed, 1.5 mmol of the modifier compound shown in Table 1 was added, and the addition reaction was carried out for 30 minutes. Thereafter, 5 ml of methanol was added to stop the reaction. Next, 15 ml of a 10% methanol solution of 2,6-di-t-butyl-p-cresol was added to the polymer solution. Each of the rubbery polymers thus obtained (weight average molecular weight: 400.0
20g of the cyclohexane solution of 00) was added to emulsion-polymerized styrene-butadiene copolymer rubber (SBR).
Latex (bound styrene content 25%, polystyrene equivalent weight average molecular weight 400,000, solid content in latex 2
5%) to 400 g, add 10 g of surfactant (sodium laurylbenzenesulfonate), and mix with an agitator for 20 g.
A stable dispersion was obtained by stirring and mixing for a minute. HAF on this
grade carbon blank 60g, water 1200g,
A dispersion obtained by stirring and mixing 2 g of the above-mentioned surfactant with an agitator for 10 minutes was added, and the mixture was further stirred and mixed with an agitator for 30 minutes. This dispersion was then dried under reduced pressure using an evaporator at 50° C. and 5 QmmHg for 20 minutes to evaporate volatile components (mainly cyclohexane) in the dispersion. Thereafter, the pH of the dispersion liquid was adjusted to 3 using sulfuric acid to coagulate the rubber composition. The further coagulated rubber composition was 60
It was vacuum dried at 10 mdg for 24 hours. Rubber compositions A-C were thus obtained. Zinc white No. 1 No. 3 in rubber composition
g, 2 g of stearic acid, 1.75 g of sulfur, 5 g of aromatic processing oil and 1.1 g of N-cyclohexyl-2-benzothiazolesulfenamide were added, and the rubber composition was kneaded using a roll.

The time required for kneading was 10 minutes. Then 16 (1℃
A test piece was obtained by press vulcanization for 25 minutes at 60° C., and its impact resilience at 60° C., wet skid resistance, and pico abrasion were measured.

The impact resilience at 60°C was measured using a test piece described in JIS K-6301 on a test piece left in an atmosphere at 60°C. Wet skid resistance was measured by ASTM at 23°C using a portaple skin tester (manufactured by Stansey, UK).
Measurements were made on the road surface of E-303-74 (3M outdoor type B, black Safety Walk). Also, pico wear is A
The method specified in STM D-2228 was used.

Wet skid resistance and abrasion resistance were expressed as an index, with Example I set at 100 based on the measurement results of pico abrasion. The smaller the numerical value, the worse the wear resistance. The results are shown in Table 1.

Comparative Example 1 480 g of emulsion polymerized SBR latex used in Example 1, 60 g of HAF grade carbon black, and 1200 g of water
A rubber composition was prepared in the same manner as in Example 1, except that a dispersion obtained by stirring and mixing g and 2 g of the above-mentioned surfactant (sodium laurylbenzenesulfonate) with an agitator for 10 minutes was added, and the mixture was further stirred and mixed with an agitator for 30 minutes. I got it. At this time, the kneading time with the rolls was 10 minutes. The measurement results of the rubber physical properties are also listed in Table 1.

Comparative Example 2 480 g of the emulsion polymerized SBR latex used in Example 1 was coagulated and dried by a conventional method to obtain 100 g of rubber. To this, 2 g of the above-mentioned surfactant, 60 g of HAF grade carbon black, 3 g of zinc white No. 1, 2 g of stearic acid, 1.75 g of sulfur, 5 g of aromatic processing oil, and N-cyclohexyl-2-benzothiazole sulphate. 1.1 g of phenamide was added, and the rubber composition was kneaded using a roll. The time required for kneading was 10 minutes. Then 160
A test piece was obtained by press vulcanization at .degree. C. for 25 minutes, and its impact resilience at 60.degree. C., wet skid resistance, and pico abrasion were measured. The measurement results of the rubber physical properties are also listed in Table 1.

Comparative Example 3 A stainless steel polymerization reactor with an internal volume of 21 cm was washed and dried,
After purging with dry nitrogen, 120 g of 1,3-butadiene
, 40 g of styrene, 840 g of cyclohexane, 0.5 mmol of tetramethylethylenediamine, and 0.4 mmol of n-butyllithium (n-hexane solution) were added, and the contents were polymerized at 45°C for 5 hours while stirring. Ta. After the polymerization reaction, 4,4'-bis(diethylamino)
1.5 mmol of benzophenone was added and the addition reaction was carried out for 30 minutes. Then add 5 mI of methanol! 6 Next, add 15 m of a 10% methanol solution of 2,6-di-t-butyl-p-cresol to the polymer solution to stop the reaction.
f was added. The rubbery polymer thus obtained was coagulated and dried by a conventional method to obtain Polymer I (weight average molecular weight: 400.000).

The SBR latex used in Example 1 was coagulated and dried in a conventional manner to obtain polymer (2).

Polymer I20g, Polymer! 1100g, HAF grade carbon blank 60g, zinc white No. 1 3g, stearic acid 2g, sulfur 1.75g, aromatic process oil 5g
, and 1.1 g of N-cyclohexyl-2benzothiazole sulfenamide were added, and the rubber composition was kneaded using a roll. The time required for kneading was 10 minutes. The rubber composition thus obtained was vulcanized in the same manner as in Example 1, and the physical properties of the rubber were measured. The results are also listed in Table 1.

Example 4 A stainless steel polymerization reactor with an internal volume of 21 cm was washed, dried,
After purging with dry nitrogen, 120 g of 1,3-butadiene
, 40 g of styrene, 840 g of cyclohexane, 0.5 mmol of tetramethylethylenediamine, and 0.4 mmol of n-butyllithium (n-hexane solution) were added, and the contents were polymerized at 45°C for 5 hours while stirring. I did it. After the polymerization reaction was completed, 1.5 mmol of 4,4'-bis(diethylamino)penzophenone was added, and the addition reaction was allowed to proceed for 30 minutes. Thereafter, 5 ml of methanol was added to stop the reaction. Next, add 10% methanol solution of 2.6-di-t-butyl-p-cresol to the polymer solution.
! Added. The thus obtained organic solution containing 20 g of the rubbery polymer (weight average molecular weight 400.000) was added to 250 g of water, and the above-mentioned surfactant 5.
Add g and stir and mix with an agitator for 10 minutes, and add
Micelles of organic solvent were formed in which the rubbery polymer was dissolved. Then, use an aspirator to increase the temperature to 60+ssHg and 60℃.
The organic solvent was evaporated under the following conditions to obtain a liquid mixture in which the rubbery polymer was suspended in water (mixture I). Add to this 60g of HAF grade carbon black and 60g of cyclohexane.
A dispersion prepared by stirring and mixing 0g for 10 minutes was added, and further 3
The mixture was stirred and mixed with an agitator for 0 minutes. Then, 400 g of the emulsion polymerized SBR latex used in Example 1 was added and mixed with an agitator for 20 minutes. Thereafter, test pieces were obtained in the same manner as in Example 1, and the physical properties of the rubber were measured. At this time, the time required for crosstalk due to the rolls was 10 minutes. Rubber physical properties are also listed in Table 1.

Example 5 120 g of 4,4'-bis(diethylamino)benzophenone was added to 509 mj of benzene in a 21 eggplant type flask.
After dissolving the solution in and purging with nitrogen, n-butyllithium (n-hexane solution) was added in an amount 1.3 times the molar amount of the benzophenone. Stirring was continued for 2 hours while cooling in ice water. Thereafter, a large excess of methanol relative to the number of moles of n-butyllithium was added to perform hydrolysis. After filtering off the resulting precipitate, the filtrate was mixed with a large amount of ether and water. After shaking thoroughly, the mixture was allowed to stand and the supernatant ether layer was separated. Powders of Na, SO, and anhydride were added to the separated ether layer, and after dehydration, the precipitated Na, So.

2) 1.0 was filtered out. Ether and benzene were evaporated from the filtrate using an evaporator according to a conventional method to obtain a yellow powder. Hydrochloric acid 1.5 times the molar amount of the original 4,4'-bis(diethylamino)benzophenone was added to the powder to obtain Substance I exhibiting a blue color. 120g of the substance in 2000ml of water
g and mixed using an agitator. H to this liquid
AF grade carbon black 60g, water 1600g
Add a dispersion prepared by stirring and mixing 10 g of
The mixture was stirred and mixed using an agitator for a minute. Furthermore, 400 g of the emulsion polymerized SBR latex used in Example 1 was added and mixed for 20 minutes using an agitator. Thereafter, test pieces were obtained in the same manner as in Example 1, and the physical properties of the rubber were measured. At this time, the time required for kneading with rolls was 10 minutes.

Rubber physical properties are also listed in Table 1.

Example 6 A stainless steel polymerization reactor with an internal volume of 21 cm was washed, dried,
After purging with dry nitrogen, 120 g of 1,3-butadiene
, 40 g of styrene, 840 g of cyclohexane, 0.5 mmol of tetramethylethylenediamine, and 0.4 mmol of n-butyllithium (n-hexane solution) were added, and the contents were polymerized at 45°C for 5 hours while stirring. 0 After the polymerization reaction was completed, 5 ml of methanol was added, and 2 ml of methanol was added.
．． 10% methanol solution of 6-di-t-butyl-p-cresol at 15 mA! Added. In this way, the amount of bound styrene is 25%, and the weight average molecular weight in terms of polystyrene is 400.0.
A cyclohexane solution of SBR of 00 was obtained.

Next, an aqueous solution in which 120 g of the substance used in Example 5 was dissolved in 2000 g of water was added and mixed, and then 60 g of HAF grade carbon black and 1600 g of water were stirred and mixed for 10 minutes to prepare a dispersion liquid in advance, and the above-mentioned solution was prepared. The mixture was added to 625 g of a cyclohexane solution of SBR, and further stirred and mixed using an agitator for 30 minutes. Thereafter, test pieces were obtained in the same manner as in Example 1, and the physical properties of the rubber were measured. At this time, the time required for kneading with rolls was 10 minutes. Rubber physical properties first
Also listed in the table.

Example 7 A stainless steel polymerization reactor with an internal volume of 21 cm was washed, dried,
After purging with dry nitrogen, 120 g of 1,3-butadiene
, 40 g of styrene, 840 g of cyclohexane, 0.5 mmol of tetramethylethylenediamine, and 0.4 mmol of n-butyllithium (n-hexane solution) were added, and polymerization was carried out at 45°C for 5 hours while stirring the contents ( Weight average molecular weight 400.000). After completion of polymerization reaction 4
．． 4'-bis(diethylamino)benzophenone in 1.
5 mmol was added and the addition reaction was carried out for 30 minutes. Thereafter, 5 mjt of methanol was added to stop the reaction.

Next, 15 ml of a 10% methanol solution of 2,6-di-t-butyl-p-cresol was added to the polymer solution. The S used in Example 6 was added to 125 g of the rubber solution thus obtained.
625 g of a cyclohexane solution of BR was added and mixed.

Add 60g of HAF grade carbon black to this solution.
A dispersion obtained by stirring and mixing 1600 g of water for 10 minutes was added, and the mixture was further stirred and mixed using an agitator for 30 minutes. Thereafter, test pieces were obtained in the same manner as in Example 1, and the physical properties of the rubber were measured.

At this time, the time required for crosstalk due to the rolls was 10 minutes. Rubber physical properties are also listed in Table 1.

Example 8 A dispersion obtained by stirring and mixing 60 g of HAF grade carbon blank and 600 g of cyclohexane for 10 minutes was added to a liquid separated so that the rubber component in Mixed Liquid I used in Example 4 was 20 g, and further 30 g of rubber component was added. The mixture was stirred and mixed using an agitator for a minute. Next, 625 g of the cyclohexane solution of SBH used in Example 6 was added to and mixed with this mixed solution, and the mixture was stirred for 10 minutes. Thereafter, test pieces were obtained in the same manner as in Example 1, and the physical properties of the rubber were measured. At this time, the time required for jRH using the roll was 10 minutes. Rubber physical properties are also listed in Table 1.

Example 9 A stainless steel polymerization reactor with an internal volume of 21 cm was washed, dried,
After purging with dry nitrogen, 1,3-butadiene 112.
5 g, styrene 37.5 g, benzene 820 g,
0.75 g of tetrahydrofuran and 30 mmol of n-butyllithium (n-hexane solution) were added, and the contents were polymerized at 45° C. for 2 hours while stirring. After the polymerization reaction was completed, 250 mmol of 4,4'bis(diethylamino)benzophenone was added and the addition reaction was carried out for 30 minutes.

Thereafter, 5 ml of methanol was added to stop the reaction (weight average molecular weight 6,000), and then 2.6 ml of methanol was added to the polymer solution.
15 ml of a 10% methanol solution of -di-t-butyl-p-cresol was added. Each of the polymer solutions thus obtained was vacuum-dried using an evaporator at 50°C and 10 sHg for 20 hours to evaporate volatile components (mainly benzene) in the solutions to obtain liquid rubbers. All of the produced polymers had a weight average molecular weight of 5000 and were fluid at room temperature. To 20 g of this liquid rubber were added 250 g of the emulsion polymerized SBR latex used in Example 1 and 10 g of MA-type sodium alkylbenzenesulfonate, and the mixture was thoroughly stirred. A dispersion prepared by stirring and mixing 60 g of HAF grade carbon blank and 1,600 g of water for 10 minutes was added to this mixture, and the mixture was further stirred and mixed using an agitator for 30 minutes. Thereafter, test pieces were obtained in the same manner as in Example 1, and the physical properties of the rubber were measured. At this time, the time required for kneading with rolls was 10 minutes.

Rubber physical properties are also listed in Table 1.

The kneading time of the rubber compositions of the present Examples and Comparative Examples was 10
However, there is a large difference in the physical properties of the rubber. This is probably due to the large difference in the dispersibility of carbon black in the rubber composition.

Claims (3)

[Claims] (1) A rubber composition characterized by mixing rubbery polymer latex or solution and carbon black in the presence of a compound having a bond represented by ▲ mathematical formula, chemical formula, table, etc. ▼ in the molecule. manufacturing method. (2) (a) Latex or solution of rubber-like polymer and (
2) The method for producing a rubber composition according to claim 1, wherein a dispersion of a mixture of carbon black and the compound is mixed. (3) A rubber composition obtained by the method according to claim (1).