JPH05331223A - Production of polymer - Google Patents

Abstract

PURPOSE:To efficiently obtain a polymer having low hysteresis loss by adding a tetrahalogenated tin compound to a polymerization system in polymerizing a conjugated diene and/or a vinyl aromatic hydrocarbon using an organolithium compound as an initiator. CONSTITUTION:A halogenated tin compound of the structural formula SnX4 (X is halogen) (e.g. tin tetrachloride or tin tetrabroride) in an amount of <0.25mol equiv. to >=0.18mol equiv. based on 1mol equiv. polymerization active terminal lithium is added to a polymerization system during a polymer chain growth period just after starting the polymerization to 80%, preferably 25% conversion ratio in polymerizing a conjugated diene (preferably 1,3-butadiene) and/or a vinyl aromatic compound (preferably styrene) in a hydrocarbon solvent using an organolithium compound (preferably n-butyl-lithium or t-butyl-lithium) as an initiator to carry out the polymerizing reaction. After completing the polymerizing reaction, a modifying agent such as a tin compound or an isocyanate group-containing compound, as necessary, is added to produce the objective polymer containing >=50% high-molecular weight polymer having tin-carbon bond chain at a low cost with good productivity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for producing a polymer which has a low loss factor and is excellent in breaking properties with high productivity and at low cost.

[0002]

2. Description of the Related Art With the demand for low fuel consumption of automobiles, a rubber having a small loss factor, that is, a hysteresis loss, is desired as a rubber for a tire material. Natural rubber, cis-1,4 polyisoprene rubber, low cis-1,4 or high cis-1,4 polybutadiene rubber and the like are known as rubber materials having a small loss factor. Also, as a synthetic rubber with significantly improved loss factor, in a hydrocarbon solvent,
There is a synthetic rubber obtained by coupling a tin halide compound to the end of a polymer obtained by polymerizing an organic lithium compound as an initiator (for example, JP-A-57-55912). When a coupling reaction is carried out with a tin halide compound at the end of the polymer, the polymerization reaction ends when the tin compound is added, and the reaction system becomes deactivated when the coupling reaction ends. Therefore, it is considered that the polymerization does not continue even if the unreacted monomer remains. On the other hand, considering the molecular structure of the polymer, when the tin compound is added,
The molecular structure such as the degree of polymerization of the polymer is determined, and finally the molecular structure of the polymer having tin in the molecular chain is determined.

Therefore, in order to prevent the unreacted monomer from being left behind, from the viewpoint of reaction mechanism and economic reasons, and from the viewpoint of molecular design in terms of molecular structure, a tin compound is usually added at the time when the polymerization reaction is completed. Is used.

As described above, in the conventional method using a modifier such as a coupling agent such as a tin halide compound, even after the modifier is added to the reaction system, even if the monomer or the like remains. Then, it is considered that no reaction can take place or is no longer utilized, and the process for recovering the target polymer is started. That is, a batch polymerization system is adopted. Compared to the continuous polymerization method, the batch polymerization method has a poor productivity, resulting in high manufacturing cost, and as a result, the polymer becomes expensive, which is a big problem.

On the other hand, when attention is paid only to the continuous polymerization method, as a method of producing a polymer capable of this, a method of producing a blend of polydiene rubber using an organic lithium compound or the like as an initiator (Japanese Patent Laid-Open No. 63-235305). )It has been known. This is because tin-carbon is obtained by adding a certain amount of a branching agent such as tin tetrachloride to the middle stage of the polymerization such as butadiene-styrene copolymerization (conversion rate is 30 to 70%) and coupling 20 to 70% of the polymer. First, a low molecular weight polymer (A) having a bonding chain is produced, and then polymerization is continued with the remaining active terminal lithium to produce a high molecular weight polymer (B) containing no tin-carbon bonding chain. ) A method for producing a polymer blend mainly composed of the polymer (B) with respect to the polymer. This production method is intended to obtain a polymer having improved processability by producing a low molecular weight polymer and a high molecular weight polymer in a polymerization process without using an ordinary blending method. Even though such a continuous polymerization method is known, at present, a method for producing an excellent polymer having a small loss factor is not yet known.

[0006]

As described above, there has been a demand for a production method for obtaining an excellent polymer by a continuous polymerization method having high productivity, instead of the batch polymerization method having high production cost.

In view of the above circumstances, the present invention is a polymer which is a polymer having excellent breaking properties and which is mainly composed of a high molecular weight polymer having a tin-carbon bond chain, that is, a loss factor is small. It is an object of the present invention to provide a method for producing a polymer, which enables the polymer to be obtained with good productivity and at low cost.

[0008]

The method according to claim 1 is a method for producing a polymer by polymerizing a conjugated diene and / or a vinyl aromatic hydrocarbon with an organolithium compound as an initiator in a hydrocarbon solvent. At the structural formula SnX
_The tin halide compound represented by ₄ (X: halogen) is added in an amount of 0.25 with respect to 1 molar equivalent of lithium at the polymerization active terminal
An amount of less than 0.18 molar equivalents or more than 0.18 molar equivalents is added to the polymerization system immediately after the initiation of the polymerization until the conversion rate reaches 80% in the polymerization system to carry out a polymerization reaction to form a tin-carbon bond chain. It is characterized in that a polymer containing 50% or more of the high molecular weight polymer is produced.

A second aspect of the present invention is the method according to the first aspect, wherein the tin halide compound is added into the polymerization system immediately after the initiation of the polymerization until the conversion rate reaches 25% during the growth of the polymerization chain. And

A third aspect of the present invention is the production method according to the first or second aspect, in which the tin compound, the isocyanate group-containing compound and -CM-N <bond (M: O or S is represented after completion of the polymerization reaction. ) At least one compound selected from the contained compounds is added as a modifier.

As a result of intensive investigations, the present inventors have paid attention to the polymerization reaction with organolithium, the coupling reaction with a tin halide compound, the bond structure of tin and its reactivity, and as a result, surprisingly, under certain conditions. At, the tin-carbon bond chain-containing polymer is activated, a polymerization initiation point is generated in the polymer, polymerization of the monomer continues, and a chain grows to produce a tin-carbon bond chain-containing high molecular weight polymer. It was found that This made it possible to use a continuous polymerization method instead of the batch polymerization method. As described above, this is a new fact that overturns the established theory that the tin-carbon bond chain-containing polymer is conventionally inactive and the monomer polymerization is not continued, so that the batch polymerization method is inevitably adopted.

More specifically, SnCl ₄ is added as a coupling agent when random copolymerization of butadiene and styrene is carried out in a hydrocarbon solvent using a butyllithium compound as an initiator and an ether compound or the like. For example, if SnCl ₄ is added from less than 0.25 molar equivalent to 0.18 molar equivalent or more with respect to 1 molar equivalent of polymerization active terminal lithium after the initiation of polymerization, it is involved in the reaction with SnCl ₄ in the system. If there is a polymerization active terminal lithium, the polymerization continues due to a part of its active points, but at the same time, the tin-carbon bond chain-containing polymer obtained by coupling is newly imparted with a polymerization ability, and the polymerization chain Continued to grow, a high-molecular-weight tin-carbon bond chain-containing random butadiene-styrene copolymer was obtained, and the vulcanized rubber obtained from this polymer contained Small effect of factors was found to be recognized significantly.

To mention that the tin-carbon bond chain-containing polymer is endowed with polymerization ability, for example, homopolymerization of butadiene is carried out in the same manner as described above, and the molecular weight of the polymer is a number average molecular weight. When it reaches 1.8 × 10 ⁴ , S
When 0.21 molar equivalent of nCl ₄ was added to 1 molar equivalent of lithium at the polymerization active terminal, the number average molecular weight of this polymer was 7.2 × 10 ⁴ , and the total number of the polymers after the continuous polymerization was further increased. It became clear that the number-average molecular weight of the tin-carbon bond chain-containing polybutadiene contained in No. 1 reached 50 × 10 ⁴ .

Although the mechanism of imparting the polymerization ability of the tin-carbon bond chain-containing polymer is unknown, the polymerization ability is not limited to butyllithium or polymerization active terminal lithium and tetraallyltin type or tetrabenzyltin in the polymer. Since it functions when a type bond is present, it is presumed that a polymerization active point is generated by some interaction between the polymerization active terminal lithium and this tin bond.

As described above, in the present invention, if the quantitative requirements for the lithium having a polymerization active terminal and the tin halide compound are satisfied, the tin compound is not obtained after the polymerization of the monomer but at the time of chain growth, that is, in the presence of the lithium having a polymerization active terminal. Since the chain growth of the tin-carbon bond chain-containing polymer is continued as long as the monomer is present even after carrying out the coupling reaction by adding, it is possible for the first time to achieve a highly productive continuous polymerization method, and still obtain it. The obtained polymer was mainly composed of a high-molecular weight polymer containing a tin-carbon bond chain, and it was revealed that it has useful physical properties with a small loss factor, and the present invention has been completed.

The present invention will be described in more detail below.
The polymerization solvent is an inert organic solvent, for example, benzene, toluene, an aromatic hydrocarbon solvent such as xylene,
Aliphatic hydrocarbon solvents such as n-pentane, n-hexane and n-heptane, alicyclic hydrocarbon solvents such as methylcyclopentane and cyclohexane, and mixtures thereof can be used.

In the above production method, the organolithium compound used as the initiator is n-butyllithium,
Examples include ethyllithium, propyllithium, tert-butyllithium, hexyllithium, 1,4-dilithiobutane, alkyllithium such as a reaction product of butyllithium and divinylbenzene, alkylenedilithium, phenyllithium, stilbendilithium, and the like. .. Preferred is n-butyl lithium or tert-butyl lithium. These organolithium initiators may be used alone or in combination of two or more. The amount of these organolithium compounds used can be used in the range of 0.2 to 30 mmol per 100 grams of the monomer.

In the present invention, the monomer used for the polymerization is a conjugated diene and / or a vinyl aromatic hydrocarbon, and the conjugated diene contains a conjugated diene containing 4 to 12 carbon atoms, preferably 4 to 8 carbon atoms. It is a diene hydrocarbon. For example, 1,3-butadiene, isoprene, piperylene, 2,3-dimethyl-1,3-butadiene, 1,3-
Pentadiene, octadiene and the like can be mentioned, and these conjugated dienes can be used alone or in combination of two or more kinds,
Particularly, 1,3-butadiene is preferable.

As the vinyl aromatic hydrocarbon, styrene, α-methylstyrene, p-methylstyrene,
Included are o-methylstyrene, p-butylstyrene, vinylnaphthalene and the like, with styrene being particularly preferred.

Examples of the tin halide compound represented by the structural formula SnX ₄ (X: halogen) of the method of the present invention include tin tetrachloride and tin tetrabromide. The amount of addition to the reaction system is from less than 0.25 molar equivalent to 0.18 molar equivalent or more with respect to 1 molar equivalent of lithium at the polymerization active terminal.

The amount of the tin halide compound added to the polymerization active terminal lithium is an important factor for achieving the object of the present invention. Although the ratio of the high molecular weight polymer containing a tin-carbon bond chain to the polymer not containing a tin-carbon bond chain in the entire polymer is 50% or more, it can be said that the polymer has a small loss factor, The larger this ratio, the smaller the loss factor, which is preferable. The proportion of the high molecular weight polymer depends largely on the proportion of lithium and tin halide, and a polymer having a small loss factor can be easily obtained within the range of the tin halide compound addition amount. Can be reached.

When the addition amount is 0.25 molar equivalent or more, unreacted polymerization active terminal lithium does not remain, so that the polymerization reaction cannot be continued at all. That is, since chain formation of the tin-carbon bond chain-containing polymer, which is an important feature of the present invention, does not occur, the present invention cannot be realized. Further, when the addition amount is less than 0.18 molar equivalent, chain growth of the tin-carbon bond chain-containing polymer occurs, but the tin-carbon bond chain-containing polymer starts at the concentration of the polymerization initiation point. Due to the relative increase in the concentration of free active terminal lithium, which does not seem to be involved in the point formation, tin-independent polymerization at this active point predominantly proceeded, and the obtained total polymer was tin-carbon. For polymers that do not contain a binding chain, tin-
The proportion of the high molecular weight polymer containing a carbon-bonded chain is less than 50%, and the desired physical properties become poor, which is not preferable.

In the present invention, an important factor together with the addition amount of the tin halide compound is the timing of addition of the tin halide compound. The timing of this addition is 80%, preferably 25%, immediately after the start of the polymerization with the organolithium compound.
It is added to the polymerization system during the period of growth of the polymerization chain until reaching. From the viewpoint of satisfying the two effects of achieving the continuous polymerization method and obtaining a polymer having a small loss factor, the conversion rate of 80% immediately after the initiation of the above polymerization.
However, the coupling efficiency is good if the coupling reaction is carried out at the stage of low viscosity after the initiation of the polymerization, and the coupling efficiency is good for various reasons at the initial stage of the polymerization. Due to the low deactivation of the active terminal lithium, a tin-carbon bond chain-containing high molecular weight polymer, that is, a polymer having a small loss factor can be efficiently obtained, and a continuous polymerization method can be stably carried out for the reason. It is preferable to add the tin halide compound immediately after the initiation of the polymerization and at the beginning of the polymerization such that the conversion is 25%. If a tin halide compound is added before the polymerization starts, the desired polymer cannot be obtained because it reacts with the organolithium initiator to form organotin, and after the initiation of the polymerization, the conversion exceeds 80%, If you add it after the end,
The features of the continuous polymerization method of the present invention will be lost.

In the present invention, the molecular structure of the desired polymer (molecular weight, microstructure, in the case of a copolymer, in addition to this, the composition of the monomer unit, its composition distribution, etc.) depending on the improvement of the polymerization activity and / or the application The conventional additives used for this purpose, for example, Lewis bases such as ether compounds and tertiary amine compounds, can be added to the reaction system in order to adjust the above). Examples of the ether compound used include diethyl ether, dibutyl ether, tetrahydrofuran,
2-methoxytetrahydrofuran, 2-methoxymethyltetrahydrofuran, dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether and the like can be mentioned. Further, as secondary amine compounds, triethylamine, tripropylamine, pyridine, N, N,
N ', N'-tetramethylethylenediamine, N, N,
Examples thereof include N ', N'-tetraethylethylenediamine and N-methylmorpholine. Ether compounds and third
The amount of the primary amine compound used is 0.05 to 1000 mol per mol of the organic lithium compound.

In the present invention, when the continuous polymerization method has to be interrupted due to the convenience of the process, or when it is desired to impart a desired physical property to the polymer by changing the molecular design, a modifier is added after the completion of the polymerization reaction. It can be added. As the modifier, a tin compound, an isocyanate group-containing compound and -CM
At least one compound selected from the compounds containing -N <bond (representing M: O or S).

Examples of the tin compound include tin halides such as tin tetrachloride and tin tetrabromide, and halogenated organic compounds such as diethyldichlorotin, dibutyldichlorotin, tributyltin chloride, diphenyldichlorotin and triphenyltin chloride. A tin compound etc. can be mentioned.

Examples of the isocyanate group-containing compound include phenyl isocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenyl methane diisocyanate, naphthalene diisocyanate and their two amounts. And trimeric aromatic polyisocyanate compounds can be used.

Examples of the compound containing -CM-N <bond (representing M: O or S) include formamide, N,
N-dimethylformamide, acetamide, N, N-diethylacetamide, aminoacetamide, N, N-dimethyl-N ′, N′-dimethylaminoacetamide,
N, N-dimethylaminoacetamide, N, N-dimethyl-N'-ethylaminoacetamide, acrylamide, N, N-dimethylacrylamide, N, N-dimethylmethacrylamide, nicotinamide, isonicotinamide, picolinic acid amide, N , N-dimethylisonicotinamide, succinamide, phthalamide, N, N,
N ', N'-tetramethylphthalamide, oxamide, N, N, N', N'-tetramethyloxamide,
1,2-cyclohexanedicarboxamide, 2-furancarboxylic acid amide, N, N-dimethyl-2-furancarboxylic acid amide, quinoline-2-carboic acid amide, N
Amide compounds such as -ethyl-N-methyl-quinolinecarboxylic acid amide, succinimide, N-methylsuccinimide, maleimide, N-methylmaleimide, phthalimide, imide compounds such as N-methylphthalimide, ε-caprolactam, N-methyl- ε-caprolactam, 2-
Pyrrolidone, N-methyl-2-pyrrolidone, 2-piperidone, N-methyl-2-piperidone, 2-quinolone, N
-Lactam compounds such as methyl-2-quinolone, urea,
N, N'-dimethylurea, N, N-diethylurea, N,
N, N ', N'-tetramethylurea, N, N-dimethyl-N', N'-tetramethylurea, N, N'-dimethyl-N ', N'-diphenylurea, N, N'-dimethyl Urea compounds such as ethylene urea, methyl carbamate, N,
Examples thereof include carbamic acid derivatives such as methyl N-diethylcarbamate, isocyanuric acid, isocyanuric acid derivatives such as N, N ′, N ″ -trimethylisocyanuric acid, and their corresponding thiocarbonyl-containing compounds. The compound is not particularly limited as long as it is a compound that reacts with the active end of the united chain.

The polymerization temperature is usually from -20 ° C to 150 ° C.
And preferably 0 ° C to 120 ° C.

The monomer concentration in the solvent is usually 5 to 5.
It is 50% by weight, preferably 10 to 35% by weight. In the case of copolymerization of conjugated diene and vinyl aromatic hydrocarbon, the content of vinyl aromatic hydrocarbon in the charged monomer mixture is 3 to
It is 50% by weight, preferably 5-40% by weight. Also,
The reaction time is not particularly limited, but is usually several seconds to several hours.

The polymerization reaction is carried out by contacting the monomer in the liquid phase with the catalyst, but it is usually preferred to operate at a pressure which is essentially sufficient to maintain the liquid phase. Also,
It is preferable to exclude substances interfering with the catalytic action from all of the above substances charged into the reaction system.

After the reaction is completed, steam is blown into the polymer solution to remove the solvent, or a poor solvent such as methanol is added to coagulate the polymer and then dried on a hot roll or under reduced pressure to obtain the polymer. be able to. Alternatively, the polymer solution can be obtained by directly removing the solvent from the polymer solution on a hot roll or under reduced pressure.

The polymer of the present invention is a polymer containing 50% or more of a high molecular weight polymer having a tin-carbon bond chain, and it is a homopolymer of a conjugated diene or a vinyl aromatic hydrocarbon, a conjugated diene and a vinyl aromatic. It includes a copolymer with a hydrocarbon or a mixture of both polymers. Particularly useful is a high molecular weight polybutadiene or a butadiene-styrene copolymer, and the molecular weight of the high molecular weight polymer having a tin-carbon bond chain contained in 50% or more thereof can be arbitrarily controlled depending on the application. However, in many cases, a polymer having a number average molecular weight of 1 × 10 ⁵ to 15 × 10 ⁵ is useful.

Taking polybutadiene or a butadiene-styrene copolymer as an example, the microstructure of the butadiene part (cis-1,4, trans-1,4, vinyl), butadiene / styrene for the copolymer. Composition, its composition distribution (random structure, block structure or mixed structure)
Can easily obtain a polymer having a molecular structure freely selected according to the purpose, and can be applied to various uses.

For example, the butadiene-styrene copolymer of the present invention may be used alone or in a blend with a natural rubber or a synthetic rubber, and if necessary, oil-extended, and then a conventional compounding agent for vulcanized rubber is added and vulcanized. Used for anti-vibration rubber, belts, hoses and other industrial products, including tires.

[0036]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples as long as the gist of the present invention is not exceeded.

In the examples, "parts" and "%" mean "parts by weight" and "% by weight" unless otherwise specified.

Various measurements were made by the following methods. The loss factor (Tan δ) was measured using a rheometrics viscoelasticity measuring device at a temperature of 50 ° C., strain of 1%, frequency of 1
It was determined at 5 Hz. The tensile properties were measured according to JIS K6301.

The molecular weight was measured by gel permeation chromatography (GPC), and the monodisperse polystyrene was used as a standard by using the differential refractive index (RI) and the ultraviolet absorption coefficient (UV) at 254 nm. It was performed in terms of polystyrene.

The molecular weight of the tin-bonded polybutadiene polymer is a strong U.S.C. derived from the structure of the bond between the tin and the polymer. V. Utilizing the absorption characteristics, G.I. P. C. U. V.
The G.V. determined by the detector. P. C. It was calculated from the data.

The content of tin-bonded polymer is determined by G.I. P.
C. G.I. determined by the RI detector of G.G. P. C. In the above data, the area of the portion corresponding to the polymer coupled with tin, obtained as described above, was obtained by comparing with the total area. Also for the butadiene-styrene copolymer, it was determined by the RI detector that it was the same as in the case of polybutadiene.

The microstructure of the butadiene portion of the styrene-butadiene copolymer is determined by the infrared method (Morero method: DM
orero, Chim. e. Ind. , Vol. 41,
758 (1959)). The bound styrene content was determined from an infrared calibration curve based on the absorption of a phenyl group at 699 cm ^-1 .

There are various methods for measuring the concentration of the polymerization active terminal lithium, but the concentration was 68 mol% of the organolithium initiator charged at the start of the polymerization. In the polymerization using the organolithium initiator, the solvent and the like are used after being sufficiently purified in advance, but in the usual polymerization, some of the organolithium initiator is water in the polymerization system, such as carbon dioxide. It is deactivated by impurities. Generally, in the polymerization of a conjugated diene and / or a vinyl aromatic hydrocarbon having an organolithium compound as an initiator as in the present invention, the molecular weight distribution is sufficiently narrow as about 1.1, and thus the polymerization was theoretically performed. It is known that the number average molecular weight (Mn) of a polymer is satisfied by the following formula 1 (Takayuki Otsu, Experimental method for polymer synthesis, p2).
12, chemistry coterie).

Formula 1 Mn = (number of moles of monomer / number of moles of organolithium initiator)
× Monomer molecular weight It has been found that the formula 1 is substantially valid also in the polymerization experiment carried out in the present invention, and the concentration of the organolithium is assumed to be the formula 2 at a certain ratio due to impurities.

Formula 2 Active polymerization terminal lithium concentration = Effective organolithium initiator mole number = Mole number of organolithium initiator charged at the time of initiation of polymerization × Organolithium residual rate Using the same reactor, solvent and polymerization monomer of the same lot It is clear that the assumption of the equation 2 holds when the above equation is used, and this equation is objectively used both industrially and empirically. Therefore, a preliminary experiment was conducted before carrying out this series of examinations, and
The residual rate of organolithium determined by using was determined to be 68%. Therefore, the concentration of active polymerization terminal lithium was 68% of the number of moles of the organolithium initiator charged in the polymerization initiator.

Example 1 1500 g of cyclohexane and 250 of 1,3-butadiene were placed in a 5 l reactor equipped with a stirrer.
g and tetrahydrofuran 0.80 g were charged, the temperature inside the reaction vessel was adjusted to 60 ° C., and then 0.140 g of n-butyllithium was added to initiate polymerization.

After n-butyllithium was charged and the polymerization was initiated, 5 minutes later, 0.0795 g of tin tetrachloride (manufactured by Aldrich Chemical Co., high purity product) was added. At this point, butadiene had initiated polymerization, but almost no increase in the viscosity of the polymerization solvent was observed. A part of the polybutadiene at this point was taken out, the polymerization was stopped with isopropyl alcohol, and the polymerization conversion rate and the molecular weight of the polymer were measured. The conversion rate was about 10%, and the number average molecular weight was 1.8 × 10 8. ^{Was 4} . After adding tin tetrachloride, the polymerization was further continued at 60 ° C. for 12 hours.
After 0 minutes, the polymerization was stopped with isopropyl alcohol.

Next, 2,6-di-te was added to the polymer-containing liquid.
After adding 2.5 g of rt-butyl-p-cresol, the solvent was removed by steam stripping, and the obtained solid was dried on a hot roll at 100 ° C. to obtain a rubbery polymer. The polymer properties such as the number average molecular weight (Mn) of each of the obtained all polymers and all the polymers bound to tin in all the polymers, and the content of tin-carbon bonded chain polymer in all the polymers are shown in Table 1. ..

The polymer was 25 according to the formulation shown in Table 3.
After kneading and blending with a 0 cc Labo Plastomill and a 3-inch roll, vulcanization was performed at 145 ° C. for 35 minutes. The physical properties of the vulcanized product are shown in Table 2.

[Examples 2 and 3] In Examples 2 and 3, the amounts of tin tetrachloride added were 0.0710 g and 0.0830, respectively.
Example 1 was repeated except for g. As in Example 1, the properties of the obtained polymer and the vulcanized physical properties of the polymer are shown in Tables 1 and 2, respectively.

Comparative Example 1 The procedure of Example 1 was repeated except that tin tetrachloride was not added. As in Example 1, the properties of the obtained polymer and the vulcanized physical properties of the polymer are shown in Tables 1 and 2, respectively.

Comparative Examples 2 to 3 In Comparative Examples 2 and 3, the amounts of tin tetrachloride added were 0.0602 g and 0.0503, respectively.
Example 1 was repeated except for g. As in Example 1, the properties of the obtained polymer and the vulcanized physical properties of the polymer are shown in Tables 1 and 2, respectively.

Example 4 1500 g of cyclohexane and 200 g of 1,3-butadiene were placed in a 5 l reactor equipped with a stirrer.
g, 50 g of styrene and 0.80 g of tetrahydrofuran were charged, and the temperature in the reaction vessel was adjusted to 60 ° C., then n-
Butyl lithium (0.140 g) was added to initiate polymerization.

After n-butyllithium was charged and the polymerization was started, 10 minutes later (polymerization conversion of about 20%), 0.0951 g of tin tetrachloride was added. Then, the polymerization was further performed at 60 ° C. for 120 minutes and then stopped with isopropyl alcohol.

Next, 2,6-di-te was added to the polymer-containing liquid.
After adding 2.5 g of rt-butyl-p-cresol, the solvent was removed by steam stripping, and the obtained solid was dried on a hot roll at 100 ° C. to obtain a rubbery polymer. The properties of the polymer are shown in Table 1. As with the polybutadiene of the present invention, the polymer having a tin-carbon bond chain had a high molecular weight and a high content.

The polymer was 25 according to the formulation shown in Table 3.
After kneading and blending with a 0 cc Labo Plastomill and a 3-inch roll, vulcanization was performed at 145 ° C. for 35 minutes. The physical properties of the vulcanized product are shown in Table 2.

[Examples 5 to 8] Examples 5, 6 and 7 are as follows.
Each of tin tetrachloride was 0.0879 g, 0.0795 g and 0.0716 g, and in Example 8, tin tetrabromide was 0.13 g.
Polymerization was performed in the same manner as in Example 4 except that 4 g was added.
As in Example 4, the properties of the polymer and the vulcanized physical properties of the polymer are shown in Tables 1 and 2, respectively.

Example 9 Immediately after the initiation of polymerization (polymerization conversion rate is about several%, polymerization active terminal lithium content is 0.59).
5 mmol / 100g monomer; A) 0.076 with tin tetrachloride
2 g (0.117 mmol / 100 g monomer; B, B / A =
0.197) was added, and after the polymerization conversion reached about 100%, tributyltin chloride was polymerized in the same manner as in Example 4 except that a predetermined amount was added until the color of the polymerization solvent disappeared. The number average molecular weight of all the obtained polymers was 46.
× 10 ⁴ and the vinyl content of the butadiene part is 41%
The styrene content was 20%. The physical properties of the polymer vulcanizate are 400% elongation and 258 kgf / tensile strength.
cm ² , 1% Tan δ (50 ° C.) was 0.083.

Comparative Example 4 Polymerization was carried out in the same manner as in Example 4 except that tin tetrachloride was not added. As in Example 4, the properties of the polymer and the vulcanized physical properties of the polymer are shown in Tables 1 and 2, respectively.

[Comparative Example 5] 0.1035 g of tin tetrachloride
Polymerization was performed in the same manner as in Example 4 except that the addition was made. However, in this Comparative Example 5, the polymerization was deactivated immediately after the addition of tin tetrachloride and the polymerization did not proceed. Therefore, a polymer could not be obtained, and therefore physical properties could not be examined.

[0061]

[Table 1]

[0062]

[Table 2]

[0063]

[Table 3]

As shown in Tables 1 and 2, in the examples of the present invention, a tin halide compound was used as a coupling agent at a polymerization active terminal lithium 1 molar equivalent at the initial stage of polymerization of butadiene polymerization and butadiene-styrene copolymerization. For 0.
Polymerization was carried out by adding less than 25 molar equivalents [Table 1 (B) / (A)], and the obtained polymer had a high-molecular weight tin-carbon bond as shown in Examples 1 to 3 and the like. It was a high molecular weight rubbery polymer containing 50% or more of chain-containing polymer. The vulcanizates of this polymer are compared with Comparative Examples 1 to 3 in the case of polybutadiene (Examples 1 to 3) and Comparative Example 4 in the case of butadiene-styrene copolymer (Examples 4 to 8). As can be seen, it exhibited excellent fracture characteristics and had well-balanced physical properties with a small Tan δ at 50 ° C.

Further, as shown in Example 9, it was confirmed that by adding tributyltin chloride after the completion of the polymerization and terminating the polymerization end not bound to tin with tin, the effect is further enhanced.

As described above, even though a considerable amount of the coupling agent is added at the initial stage of the polymerization, the polymerization proceeds stoichiometrically as in the ordinary living polymerization, and useful tin having a high molecular weight is used. The fact that a polymer having a carbon-bonded chain was obtained is not known in the related art, and at the same time, it is clearly shown that a continuous polymerization system was possible.

In Comparative Examples 1 and 4, tin tetrachloride (coupling agent) was not added, and the vulcanizates obtained were inferior in fracture characteristics and had a large loss factor and were not preferable in terms of heat generation. This is a phenomenon contrasted with the fact that the loss factor of the tin-carbon bonded chain-containing polymer is small, as shown in the examples.

In Comparative Examples 2 and 3, tin tetrachloride was added in an amount of less than 0.18 molar equivalent with respect to 1 molar equivalent of lithium at the polymerization active terminal. The obtained polymer was a tin-carbon bonded chain polymer. The content and the number average molecular weight are low, and the vulcanized product is inferior in fracture characteristics, has a large loss factor, and is not preferable in terms of heat generation.

In Comparative Example 5, the tin halide compound was added in an amount of 0.25 molar equivalent or more per 1 molar equivalent of the lithium at the polymerization active terminal, and the active terminal lithium was completely deactivated. It didn't happen.

[0070]

Since the method for producing a polymer of the present invention has the above-mentioned constitution, the polymer has an excellent breaking property and a continuous polymerization system is possible, and a polymer having a small loss factor can be obtained with high productivity. It has an excellent effect.

Claims (3)

[Claims] 1. A method for producing a polymer by polymerizing a conjugated diene and / or a vinyl aromatic hydrocarbon with an organolithium compound as an initiator in a hydrocarbon solvent, which is represented by a structural formula SnX ₄ (X: halogen). The tin halide compound prepared as described above is used in an amount of 0.
An amount of less than 25 molar equivalents to 0.18 molar equivalents or more is added to the polymerization system immediately after the initiation of the polymerization until the conversion rate reaches 80% to carry out the polymerization reaction, and the tin-carbon bond chain is added. A method for producing a polymer, which comprises producing a polymer containing 50% or more of a high molecular weight polymer having 2. The process for producing a polymer according to claim 1, wherein the tin halide compound is added to the polymerization system immediately after the initiation of the polymerization until the conversion rate reaches 25% during the growth of the polymerization chain. Method. 3. After the polymerization reaction is completed, at least one compound selected from a tin compound, an isocyanate group-containing compound, and a compound containing -CM-N <bond (representing M: O or S) is used as a modifier. The method for producing a polymer according to claim 1 or 2, wherein the polymer is added as.