JPS62156104A - Improved rubbery polymer - Google Patents

Abstract

PURPOSE:To provide a rubbery polymer having specific bonded styrene content, specific Mooney viscosity, etc., and excellent processability in compounding and kneading, giving a vulcanized product having excellent impact resilience, heat-generation, etc., and suitable as a tire. CONSTITUTION:For example, styrene is copolymerized with butadiene in a hydrocarbon in the presence of a catalyst composed of an organic Li compound and Lewis base and the resultant random living polymer is made to react with a branching agent and an active tin compound to obtain the objective polymer having the following characteristics. The bonded styrene content is 10-50(wt)%; a 1,2-vinyl bond content in butadiene segment is <=50%; amount of isolated styrene determined by ozonolysis GPC is >=40% of the total bonded styrene; content of long-chain block styrene is <=5%; 10-50% of the constituent molecule of the polymer is bonded in branched form with a branching agent having 4i3 functionality; an active Sn compound of formula (R1 and R2 are alkyl, etc.; X is halogen; l and m are 0 or integer of >=1; n is 1 or 2; l+m+n=4) is added to >=20% of molecule; and Mooney viscosity of the polymer is 25-150.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a conjugated diene rubber-like polymer with improved processability and vulcanizable properties. The present invention relates to a rubber-like polymer that has excellent properties such as vulcanizate elasticity, exothermic properties, etc. Vulcanized rubber using this rubbery polymer is suitable for tires (mainly Tie A7 tread).

[Conventional technology]

In recent years, due to the soaring price of crude oil, various industries (15
Many attempts have been made to reduce gasoline consumption for automobiles, such as improving the engine, reducing the weight of the car body and ties (A), reducing the air resistance of the car body, and reducing the rolling resistance of the tires. Efforts are being made to reduce the

Among these efforts to save energy related to white ωJ tons, various attempts have been made to reduce the rolling resistance of automobile tires.
Examples include methods for improving vulcanized rubber used in tire treads.

In an attempt to reduce the rolling resistance of these tires, a method for improving J+ [l 5A rubber, namely 11 [
1. Methods to reduce energy loss and improve rebound resilience or heat generation properties of rubber include improving the raw rubber used in vulcanized rubber, changing the type of carbon black, and using carbon black in vulcanized rubber. Methods of reducing the amount of carbon black or oil used to increase repulsion elasticity are being considered.

Among the above improvement methods, the method for improving raw rubber is to use a small aggregate with a higher molecular weight than before, based on the physical properties of raw rubber and the knowledge regarding the LJ of vulcanized rubber. Although elasticity cannot be improved significantly, the Mooney viscosity of the rubber and compound increases, reducing processability. On the other hand, we changed the formulation to reduce the presence of oil and carbon black.
In this method, the Mooney viscosity of the compound increases, and in this case too, the processability deteriorates, and it is difficult to improve the processability without sacrificing the processability.

On the other hand, there are some known techniques for improving the processing capacity by avoiding changes in the structure of small aggregates used as raw rubber. For example, Japanese Patent Publication No. 49-36957 discloses a method of using tetrahalosilane, trihaloalkylsilane, etc. as a coupling agent to form a branched small coalescence to improve processability. In addition, in the case of small merging using this method, the anti-elasticity of the material is insufficient and the improvement in rolling resistance is unsatisfactory.

It is also known that processability can be improved by widening the molecular weight distribution of a polymer or by increasing the number of branches; however, when using rubber-like polymers obtained by these methods,・b. The impact resilience of the vulcanizate is about the same as before the processability improvement.

JP-A-57-87407-, JP-A-58-162
Publication No. 605 discloses that when a styrene-butadiene copolymer rubber with an increased vinyl content is tin-coupled to form a branched styrene-1-tadiene copolymer rubber, a butadiene compound is added immediately before the coupling reaction to polymerize. A method is shown in which rolling resistance is improved by performing. However, even with this method, the improvement in rolling resistance is still not sufficient, and there are problems such as the manufacturing method becoming complicated.

In addition, a hexamer was continuously introduced into a polymerization zone with high stirring efficiency controlled at a temperature of 80°C or higher using a catalyst consisting of an organolithium compound and a Lewis base, and the polymerization was carried out by 3J.
A completely Langmustyrene-butadiene copolymer rubber produced by one line has been proposed (Japanese Patent Laid-Open No. 57
-100112>. This polymer showed excellent performance in terms of tensile strength, impact resilience, low heat generation, abrasion resistance/11, wet skid property, etc.

However, there was a need for further improvement in terms of rebound resilience, low heat build-up, etc.

In addition, after copolymerization of all of the styrene and part of the butadiene is initiated using a catalyst consisting of an organic lithium compound and a Lewis base, the remaining butadiene is continuously or intermittently supplied under specific conditions to copolymerize the styrene and a portion of the butadiene. A branched random styrene-butadiene copolymer obtained by adding a polyfunctional coupling agent after the polymerization has been proposed (Japanese Patent Application Laid-Open No. 140211/1989). This polymer has high impact resilience and low heat build-up. However, the needs of the tire market have become more sophisticated, and further improvements are necessary.

For this reason, there has been a demand for a rubber-like polymer that can improve rolling resistance without complicating the manufacturing process and reducing processability.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned points. This was done to increase the merging by 1q.

(Means and methods for solving the problems) The present invention was completed based on the discovery that a styrene-butadiene copolymer rubber having a specific polymer structure satisfies the above objects.

That is, the present invention is a styrene-butadiene copolymer, which (1) has a bound styrene content of 10 to 50% by weight;
The content of 1,2-vinyl bonds in the butadiene moiety is less than 5()%, the isolated styrene analyzed by GPC of A-sin decomposition is more than 40% by weight of the total bonded styrene, and the long chain block styrene is fully bonded. 5% by weight or less of styrene, (2) 10 to 50,000% of the molecules constituting the polymer are bonded in a branched manner by a trifunctional or higher branching agent, and (3) the molecules constituting the polymer are At least 20% of the general formula (
R1) B (R2) m Sn (X) n (
In the formula, R1R2 is alkyl base, aryl base, pencil base,
Alkoxy group, X represents a halogen atom, glml is O
or an integer greater than or equal to 1, "] is 1 or 21.Q + m + r)
= ζ1 is added to the active tin compound represented by The present invention provides a rubbery styrene-butadiene copolymer in which at least 30% of the molecules constituting the polymer have a Mooney viscosity of 25 to 150.

This: l (at least 510,000% polymer in the rubber component)
Carphone black 1 for every 100 car parts of raw rubber containing
A composition containing 0 to 100 parts by weight, 0.3 to 5 parts by weight of sulfur, a vulcanization accelerator, and an organic carboxylic acid is a rubber composition suitable for use in tires, mainly tire treads.

The present invention will now be described in detail.

The rubbery styrene-butadiene copolymer of the present invention is a completely random rubbery living polymer obtained by copolymerizing styrene and butadiene in a hydrocarbon solvent using a catalyst consisting of an organolithium and a Lewis base using a standard method. By reacting a trifunctional or more branching agent with a substantially monofunctional or difunctional specific active tin compound, a part of the living polymer is made into a branched polymer, and the remaining part is made into a branched polymer. It can be obtained by making part or most of it an unbranched tin addition polymer.

As the organolithium catalyst used in the present invention, “)-
-E noalkyl lithium compounds such as butyl lithium cum, 5ec-butyl lithium, n-propyl lithium, etc. are used.

During polymerization, as a co-catalyst component, di[-thyls such as diethyl ether, dimethoxyethane, diglyme, and tetrahydrofuran, amines such as triedylamine and de(-ramethylethylenediamine), hexamethylphosbortriamide, and dodecylbenzene are used. Add a Lewis base, such as the sodium or potassium salt of pinsulfonic acid, or an alcoholade such as sodium butquinide.

Polymerization is carried out in an inert hydrocarbon solvent such as benzene, toluene, l\xane, cyclohexane. The polymerization temperature is generally in the range of 30'C to 180°C, and
In order to prevent deactivation of the 14-terminus, the temperature is preferably 30°C to 150°C.

The bound styrene content of the rubbery copolymer of the present invention is 10
~501i%, preferably 13-40% by market weight. The bound styrene content of the rubbery copolymer is determined by the feed composition of the seven polymers during polymerization, and if it is less than 10% by weight, the tensile strength, modulus, and abrasion resistance will be poor, and if it exceeds 50% by weight, it will generate heat.・11 ability such as rebound elasticity is decreased. More preferably, it is 15% to 35%. In addition, the 1,2-vinyl bond in the butadiene moiety is 50% or less, preferably 13 to 48%, and if the 1,2-vinyl bond in the butadiene moiety exceeds 50%, the abrasion resistance decreases. However, if the number of '1,2-vinyl bonds is reduced, the wet skit performance will deteriorate, and in either case, the excellent performance of the copolymer of the present invention cannot be obtained. More preferably, it is 15 to 45% by weight. The 1.2-vinyl bond is controlled by the ♀ of the Lewis base which is a co-catalyst component and the polymerization temperature.

The styrene chain content 45, which is a measure of randomness in the styrene-butadiene copolymer of the present invention, is analyzed by gel permeation chromatography of a low-temperature ozonolyzed product of the copolymer. This method was developed by Kuninaka et al., and the styrene chain molecule is obtained by cleavage of all the two-handed bonds of butadiene, resulting in GPC of the 17-decomposed product.
analyzed by. (Macromolecule
s, 1983.16.1925).

The rubbery polymer of the present invention was analyzed by this method.
ff1lt styrene accounts for 40% or more of the total styrene, preferably 50% by weight or more, and long-chain blocked styrene, that is, styrene with a chain of 8 or more styrene units, accounts for 5% by weight or less of the total styrene, preferably is 2.5% by weight or less. Even if the amount of isolated styrene is less than 40% by weight or the amount of long-chain block styrene is more than 5% by weight, the excellent properties of the rubber of the present invention are high rebound resilience, low heat generation, and high wet toss. The balance of kit resistance is reduced and θr is not maintained.

In the present invention, styrene and butadiene are copolymerized,
A method for obtaining a completely random rubber-like living polymer is the method of JP-A-57-100112 or JP-A-59-140.
The method of No. 211 is preferred.

The Mooney viscosity of the living polymer to be reacted with the active compound is preferably in the range of about 3 to 60, especially from the viewpoint of the physical properties or processing of the resulting polymer (7). The range of 10 to 50 is preferable.

In addition, the molecule R molecule 1 of this living hand union is preferably relatively narrow when emphasis is placed on the impact resilience or exothermic property of the vulcanizate of the final polymer, and the range is MW/Mn or 1. f3rJ is preferably 1.4 or less, and when emphasis is placed on the balance between the rebound elasticity or heat generation of the final polymer and processability, the range is MW/MrR
]'i 1.6 or more and 3 or less, preferably 1.8 to 2.5.

The rubbery polymer of the present invention is obtained by adding a trifunctional or more branching agent to a polymer having a living miscible end obtained by the above-mentioned polymerization method, and a specific active tin having substantially monofunctional 14 or difunctionality. By reacting with a compound, a part of the above-mentioned living polymer is made into a branched polymer, and a part or most of the remaining part is made into an unbranched tin-added polymer.

The trifunctional or higher branching agent used in the reaction contains 3 or more in one molecule.
Compounds containing three or more halogen-tin bonds, halogen-silicon bonds, halogen-germanium bonds, alkoxytin bonds, aryl-tin bonds, benzyl-tin bonds, dicarboxylic acid diesters, compounds containing three or more epoxy groups, Compounds containing three or more carbonyl groups, compounds having three or more isocyanate groups, etc. are used. Among these compounds, preferably halogen-tin bonds and halogen-silicon bonds having three or more in the molecule are used, which have a fast reaction i1M with Liching lithium terminals.
These include compounds containing hydrogen, dicarboxylic acid diesters, and compounds containing three or more epoxy groups. Particularly preferred are compounds having three or more halogen-tin bonds or halogen-silicon bonds in one molecule.

Specifically, tin tetrachloride, monobutyltin trichloride, silicon tetrachloride, ethylene bistrichlorosilane, diethyl adipate, and the like are preferably used.

The polymer bonded in a branched manner by reacting with a trifunctional or more functional branching agent has at least one of the molecules constituting the rubbery polymer.
It is 0Φ amount%.

If the polymer molecules coupled with a trifunctional or more branching agent are less than 10% by weight, cold flow will result in yellowing and processability will be insufficient.The polymer molecules are preferably 15% by weight or more, more preferably 20% by weight or more. It is necessary.

On the other hand, less than 50% of the branched polymer molecules are coupled with a trifunctional or more functional branching agent. In order to achieve the high impact resilience and low heat generation properties of the present invention, it is preferably less than 40%.

On the other hand, the compounds used in the present invention to form linear polymer molecules with tin attached are co-functional or di-functional.
Specific functional tin compounds have the general formula (R1)U (R
2), Sn (x> n [R1.

R2 is an alkyl group, an aryl group, a benzyl group, an alkoxy group, Specific compounds include trimethyltin chloride, tributyltin chloride, trioctyltin chloride, trioctyltin chloride,
Examples include dibutyltin dichlorite, dioquidyltin dichloride, diphenyltin chloride, phenyltributyltin, methoxytributyltin, etc.

The linear polymer molecules bonded to tin in the present invention are at least 20% by weight of the molecules making up the polymer. If the amount of the linear (F) polymer molecules to which these tin compounds are added is less than 20 weight %, on the other hand, the effect of improving elasticity will be small, and the amount is preferably at least 30 weight %.

And the trifunctional or higher branching agent is an active tin compound! Combination is the sum of molecules coupled by a trifunctional or more active tin compound and a linear polymer molecule to which a specific monofunctional or difunctional tin compound is attached, i.e., activated tin. When the polymer molecules bonded to the compound account for at least 30% by weight of the molecules constituting the polymer, and the trifunctional or more branching agent is a compound other than an activated tin compound, it is practically monofunctional or The vulcanizability of the final rubber composition and the vulcanizability of the final rubber composition are determined by the fact that the linear polymer molecules to which the specific difunctional tin compound is added constitute at least 3% by weight of the molecules constituting the polymer. This is necessary in view of the balance between the product's elasticity and heat resistance, and it is preferable that at least 5% and 1% of the polymer molecules be treated with an active tin compound.

The reaction with such an active compound is carried out subsequent to the conjugation reaction, and the reaction is within the same scope as the Φ combination reaction.

The reaction between living polymers and tin-halogen bonds is extremely fast and instantaneous, while aryl-tin bonds, alkoxytin bonds, and benzyl-tin bonds react at a rather slow rate. Therefore, in order to obtain a rubber-like polymer consisting of a branched component of the present invention and a linear component to which an active tin compound has been added, the reaction with a living polymer is carried out with a branching agent having trifunctionality or more, and a substantially monofunctional branching agent. 1) 1 specific tin compound may be reacted at the same time, or preferably a trifunctional or more functional branching agent may be added first and then a substantially monofunctional or bifunctional specific tin compound may be reacted. The tin compound is reacted in an amount of 0.5 mole or more per mole of the remaining living polymer. If the molar ratio of the living polymer to the specific monofunctional or difunctional tin compound is outside this range, the branched polymer will increase /J[I, and the Mooney viscosity of the polymer will increase. Not only does this increase the processability, but it also reduces performance such as elasticity and low heat build-up. On the other hand, if you avoid reacting more than 1 mol of tin compounds, a lot of compounds will remain unreacted, resulting in loss.
In some cases, problems such as single-plant erosion of the device may occur.

Since the reaction between the living polymer and the active tin compound is almost quantitative, the ♀ treated with the above active 14 tin compound can be controlled by the equivalent ratio of the active lithium and each tin compound. . However, compared to the amount of lithium compound used at the start of polymerization, the amount of active cuttlefish is generally small due to the influence of trace amounts of impurities contained in the polymerization system, and taking these into consideration,
The amount of active tin compound used is controlled.

The mother of polymer molecules coupled by a trifunctional or more branching agent, the amount of polymer molecules linearly coupled by a difunctional tin compound, and the polymer to which a monofunctional tin compound has been added or untreated. The speed of polymerization can be determined by separating them using G, P, and C (gel permeation chromatography) or by comparing the curves of G, P, and C before and after the reaction. .

The rubber-like polymer of the present invention prepared as described above has a processability of ci-3 and a vulcanizable property of 11.

When the Mooney viscosity is less than 25), the tensile strength or abrasion resistance of the vulcanizate becomes a problem, and when the Mooney viscosity exceeds 150, processability deteriorates. The Mooney viscosity is preferably 30-100, more preferably 35-80.

, and the weight average molecular weight (fVIW>) measured by G, P, and C of the rubbery polymer of the present invention, and the number average molecular weight f
According to the above manufacturing method, the ratio (Fl'; v 775) to f1 (1'l5) is generally in the range of 1.3 to 3.5, and Mw /Mn is preferably in the range of 1.3 to 2.0 from the viewpoint of anti-repulsion elasticity and heat generation properties of the obtained vulcanized rubber, and when emphasis is placed on the balance between rebound elasticity, heat generation properties, and processability. Mw/A〒 is 2.0~3.
A range of 0 is preferred.

The rubbery hand aggregate of the present invention may be used alone or blended with rubber. When used in a blend with other rubber, the rubbery polymer of the present invention can be used as a raw material rubber.
Used by more than % of vehicles. io @ % Premature ejaculation The excellent properties of the composition of the present invention include high rebound elasticity, low heat build-up, and high heat] ~ The balance between skid resistance is reduced.

Other rubbers that can be used with the rubbery polymers of the present invention include various diene rubbers that are vulcanized by sulfur, such as natural rubber, synthetic cis-polyisoprene, styrene-butadiene copolymer rubber, and polybutadiene rubber. . The rubbery polymer of the present invention, alone or blended with other rubbers,
The composition is suitable for tire treads and consists of carbon black, a vulcanizing agent and a vulcanization accelerator, and an organic carboxylic acid.

The carbon black used to make the composition using the rubbery hand coalescence of the present invention preferably has a rubber 10
10 to 100 parts by weight of carbon black is used for the 0Φ hanging part. If it is less than 10 parts by mass, the tensile strength and abrasion resistance of 4T, etc. will not be sufficient, and if it exceeds 100 parts by mass, the rubber elasticity will be significantly lowered, which is undesirable. More preferably, it is 20·-80 parts by weight.

Iodine adsorption m (I A
) Carbon black with a sibdelphthalate oil absorption M (DBP > 70 ml/100 g or more) is used. Otherwise, the high balance of high tensile strength, high rebound resilience, and abrasion resistance of the present invention may not be obtained. Preferably, the IA is 60 my/U or more and the DBP is 8.
There are carbon blacks with a power rating of 0/1009 or higher. These carbon blacks include, for example, HAF, 15A
There is something called F, SAF.

In creating a composition using the rubbery polymer of the present invention,
0.0% sulfur was added as a vulcanizing agent to the 100Φ hanging part of the raw rubber.
1 to 5 parts are used.

If there is too little sulfur, tensile strength, rebound resilience, and abrasion resistance will be insufficient, and if it is too large, rubber elasticity will decrease. Preferably(),
It is 5 to 2.5 parts by weight. Further, as a vulcanization accelerator, one or more selected from sulfenamide type, guanidine type, diuram type, etc. can be used in an amount of 0.05 to 2 parts by weight per 100 parts of the raw rubber component.

Organic carboxylic acids, typically stearic acid, are used as vulcanization aids or processing aids in vulcanized rubber compositions, and in the rubbery polymer of the present invention, such organic carboxylic acids are particularly reacts with the tin compound bonded to the polymer, and the reaction product increases the interaction between the rubbery polymer and the reinforcing carbon black, resulting in improved rebound properties, low heat generation, tensile strength, etc. signs are exhibited.

The organic carboxylic acid is 0.5 to 100 parts by weight of raw rubber.
Five-fold φ section is used.

The purpose of the composition using the rubbery polymer of the present invention is to use a process oil that is normally used as a rubber compound.
It is used depending on the purpose. Process oil is its chemical groove;
They are divided into paraffinic, naphthenic, and aromatic based materials.Aromatic materials are suitable for applications where tensile strength and abrasion resistance are important, while naphthenic materials and even paraffinic materials are suitable for applications where rebound resilience and low-temperature properties are important. used for.

The appropriate amount of suspension is 5 to 100 parts by weight per 100 parts by weight of the raw rubber; if it is less than 5 parts by weight, the processability will be poor and the dispersion of carbon black will be poor, resulting in poor performance such as tensile strength and elongation. , on the other hand, if it exceeds 100 parts by weight, the tensile strength
This is undesirable as it causes a significant decrease in elasticity and hardness.

Further, if necessary, rubber compounds used in ordinary rubber compositions may be used in the rubber composition of the present invention in appropriate amounts depending on the purpose of use.

The copolymer rubber composition of the present invention is obtained by kneading the above-mentioned components by various known methods using a mixer known for use in the rubber industry, such as an oven roll or an internal mixer. Rubber products obtained through the vulcanization process exhibit superior performance compared to rubber products obtained from conventionally known rubber compositions. Among them, it exhibits particularly high rebound resilience, low heat generation, tensile strength, and wet skid property. Therefore, as mentioned above, it is suitable for tire treads, especially fuel-efficient tires, all-season tires,
It is used for cap treads, undertreads, etc. of high-performance tires, and by taking advantage of its outstanding performance, it is also used for tire parts such as tire lead walls, carcass, and cushion rubber, as well as for applications such as security rubber and industrial products. Needless to say, it can also be used.

[Examples] Examples are shown below, but these are intended to more specifically illustrate the present invention, and are not intended to limit the scope of the present invention.

Example 1 and Comparative Example 1 Cyclohexane 4 was added to a stirrer reactor with an internal volume of 10 mm.
5987, 780 g of purified 1,3-butadiene, 1629 purified styrene, and 389 g of tetrahydrofuran, and after maintaining the temperature at 40°C, 0.52 g of n-butyllithium was injected to start polymerization. Thereafter, the polymerization temperature was increased adiabatically. Once the internal temperature reached 75°C, a mixture of 138 g of butadiene and 322 g of cyclohekiline was added over 15 minutes using a metering pump, and 1 minute after the addition was complete, 0.185 g of tin tetrachloride (
(against Li).

After another minute, 1.726 g of 1
After adding helinoenyltin chloride (0.55 mol to Li) and reacting for 20 minutes, 8 g of BHT was added as an antioxidant to the polymer solution, and the solvent was removed by heating to recover the polymer. . 1q polymer (Document A) 1+4 content is 15% by weight, the microstructure of the butadiene moiety is:
1.4-trans bond 34%, 1,4-cis bond 23%
, 1,2 vinyl bond was 43%. Also, Mw/Mn
= 1.60, indicating that the GPC curve has two peaks.

In addition, the styrene content and the microstructure of the butadiene moiety were determined by measuring the IR spectrum and using the Hf Hampton method.
Obtained by playing 1E. )1w/)In is G, P, CC Shimadzu Corporation, LC-5A, column 104.10".

106, solvent, tetrahydrofuran, detector: differential refractometer), and a calibration curve using polystyrene as a standard substance.

Further, isolated styrene determined by GPC of the ozone decomposition product was 67% by weight based on the total styrene, and long chain block styrene was 0.8% by weight.

The Mooney viscosity of the polymer immediately before addition of tin tetrachloride was 22, and Mw/Mn=1.10.

In addition, polymers within the scope of the present invention and comparative polymers as shown in Table 1 were obtained by batch polymerization using various methods similar to those obtained for sample A8.

The analytical values are shown in Table 1.

Abbreviations in Table 1 THF: Tetrahydrofuran phm: parts by weight per 100 parts by weight of monomer.

The evaluation of cold flow properties is carried out by gluing a rectangular parallelepiped rubber onto a slope and heating it for 8 hours at room temperature. Items with significant deformation are considered poor, and items with slight deformation are considered good.

In addition, in Example 1-3 (sample F), all of the seven polymers were charged into the reactor at the start of polymerization, and then 1-butyllithium was injected to start the polymerization. It is outside the scope of this invention.

(The following are blank spaces) Example 2 and Comparative Example 2 Contents i1.7. Blends were obtained according to method B of the standard blending procedure of ASTM-D-3403-75 using the test Banbury Milly of I), and these were vulcanized and their respective physical properties were measured.

The measurements were performed using the method shown below.

(1) Hardness, tensile strength: According to JIS-6301.

(2) Repulsion elasticity; Lubke method according to JIS-6301. However, the rebound elasticity at 70°C was measured by preheating the sample in a 70°C oven for 1 hour and then quickly taking it out.

(3) Using a Gutkatch heat-generating Goodship flexometer, a test was conducted on line 11 with a load of 48 pounds, a displacement of 0.225 inches, and a starting speed of 50° C. and 1 rotation and 180 rpm, and the temperature rise difference after 20 minutes was expressed.

(4) Wet skid resistance Using Stanley London's Portable Skid Tester, we tested the road surface as a safety test (manufactured by 3M).
was measured according to the method of ASTM-E-808-74. It was expressed as an index with the measured value of 3B R1502 set as 100.

From the results shown in Table 3, the characteristics of the rubber using the rubbery polymer of the present invention are clear as follows.

From a comparison of Example 2-1 (Sample A) and Comparative Example 2-1 (Sample D), the impact resilience and heat generation properties were improved by using a tetrafunctional compound and a monofunctional compound together. There is.

On the other hand, Comparative Example 2-2 (Sample E) has good rebound properties and heat generation properties, but has a high Mooney viscosity and poor processability, and has poor cold flow properties when only a monofunctional compound is used. It shows the shortcomings of

Comparative Example 2-3 (Sample ``)'' is out of the scope of the present invention because it contains a large amount of long-chain blocked styrene, and has poor impact resilience and heat generation properties. Comparative Example 2-4 (Sample G) is polybutadiene and falls outside the scope of the present invention. In Comparative Example 2-5 (sample 1-1), the styrene content was outside the range of the present invention, and the rebound and heat generation properties were poor.

The effects of the present invention are also exhibited in other embodiments, and
High elasticity, low heat generation and heat generation.

The vulcanized rubbers of these examples have a good balance between rolling resistance, anti-rolling elasticity and heat generation properties, and web (...skid) resistance, and are particularly suitable for tie A7.

(Left below) Table-2 Compound No. 1 Raw material rubber 100 parts by weight Aromatic oil 10 parts by weight E3 parts N-33
9 Carbon Brazda 250 Parts by weight Stearic acid
2 parts by weight Naka lead flower
3.5 parts by weight Accelerator CZ"' 1
．． 3 parts by weight Sulfur 2 parts by weight *1 Kyodo Sekiyu X-140 *2 Iodine adsorption m (IA) 90 mg/g dibutyl phthalate adsorption ffl (DBP) 119d/100
9*3 N-Cyclohexyl-2-benzothiazylsulfenamide Vulcanization conditions: 160'CX 20 minutes Example 3 and Comparative Example 3 As shown in Table 4, sample A or C was blended with another rubber to produce rubber. A composition was prepared using the ingredients shown in Table 2, and the physical properties were measured in the same manner as in Example 2.

As is clear from the results in Table 4, even when blended with other rubbers, the polymer of the present invention has an excellent balance between anti-elasticity and wet skid properties of the vulcanizate, and is useful for vulcanizates. It is the source of rubber.

Example 4 Two reactors with an internal volume of 10.0 and a stirrer were connected in series to produce purified 1,3-butadiene 1 as a monomer.
7.9 g/min, purified styrene 7.5 g/min
.

n-hexane as a solvent at a rate of 109.3 g/min, and n-butyllithium as a catalyst at a rate of 0.0 g/min for all seven units.
65 phm, butramethylethylenediamine o, 0
30 phm was fed from the bottom of the first day using a metering pump, and purified 1,3-butadiene 4.6 g/min and n-hexane 10. 7 g/min, stirring rotation speed 25 rpm, internal temperature 105°C average) (■ Rumoi time was 45 minutes. Polymer was sampled at the outlet of the first unit, and Mooney viscous 100
'C degree was measured and ML 4o was obtained. Furthermore, polymer 1
+4 Continuously introduce the solution into the bottom of the second unit, and
Silicon chloride 0.00651) hm (0 for Li
．． 15 equivalents) was continuously added to 7J [I L, and then 0.293 phm of triphenyltin chloride (0.7 to L
A solution of 5 phm) was continuously added to carry out the reaction.

The temperature of the second unit was controlled at 100°C. Continuously add BHTo, 75ph, to the polymer solution that came out of the second group.
m was added, the solvent was removed by heating, and the polymer was recovered. The obtained polymer has a Mooney viscosity of 100°C ML 60. Contains styrene @ 25% by weight, but 1+4 The microstructure of the diene part is 1,4-trans bond 46
%, 1,4-cis bond 32%, 1,2-vinyl bond 22
%Met. Further, MW/Mn was 2.2, indicating that the GPC curve had one peak. In addition, isolated styrene determined by GPC of ozone decomposed product is 6% of total styrene.
5% by weight, and long chain block styrene is 0.2% by weight.
Met. The obtained polymer was vulcanized into a compound No. 11 in the same manner as in Example 2, and its physical properties were measured. The results are shown in Table-5.

Comparative Example 4-1 The same procedure as in Example 4 was carried out. However, all of the seven stirrings were performed from the bottom of the first reactor, and the stirring rotation speed of the first reactor was set to 25 rpm, which is 1/10. The resulting polymer is rich in long chain block styrene. Table 5 shows the results.
Shown below.

Comparative Example 4-2 The same procedure as in Example 4 was carried out. However, triphenyltin chloride was not added to the second reactor. The results are shown in Table-5.

As is clear from the results in Table 5, the polymer of the present invention is extremely excellent in the impact resilience of the vulcanizate and the balance of wet skid, and is also excellent in tensile strength.

Table 5 0-roll processability using an 8-inch roll, winding property of the roll, operation 1!1. was evaluated.

〔Effect of the invention〕

As mentioned above, the rubbery polymer according to the present invention has improved cold flow properties and roll lJ0 workability, and the vulcanizate has a balance between rebound resilience and heat generation, which are a measure of rolling resistance, and wet skid resistance. These properties are also good when blended with other rubbers. Vulcanized rubber using the rubbery polymer of the present invention is particularly suitable for tire applications, mainly tire treads, and has great industrial significance.

Claims (1)

[Scope of Claims] A styrene-butadiene copolymer, comprising: (1) a bound styrene content of 10 to 50% by weight;
The content of 1,2-vinyl bonds in the butadiene moiety is 50% or less, and the isolated styrene analyzed by ozonolysis GPC is (40% by weight or more of the total bonded styrene), and the long chain block styrene is 5% of the total bonded styrene. (2) 10 to 50% by weight of the molecules constituting the polymer are bonded in a branched manner by a branching agent having trifunctionality or more, and (3) at least 20% by weight of the molecules constituting the polymer. The general formula (
R_1)_l(R_2)_mSn(X)_n [in the formula R_
1R_2 is an alkyl group, an aryl group, a benzyl group, an alkoxy group, (4) Of the molecules treated in (2) or (3), the molecules bonded to the active tin compound form at least one of the molecules constituting the polymer. (5) A rubbery styrene-butadiene copolymer having a Mooney viscosity of 25 to 150.