JP3538879B2 - Method for producing novel polybutadiene composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for producing a polybutadiene composition consisting essentially of two or more polybutadiene components having mutually different melting points, but both having mainly a 1,2-structure. is there. The polybutadiene composition obtained by the method of the present invention is useful for modifying a synthetic polymer material, reinforcing a rubber material, and the like.

[0002]

2. Description of the Related Art Polybutadiene having a 1,2-structure as a main structure (hereinafter referred to as "1,2-polybutadiene") is
Since it has a vinyl group in the side chain, it is expected to have excellent kneading properties with other polymers and elastomers.
It is generally known that 1,2-polybutadiene having a relatively high melting point of about 150 ° C. or higher is a tough resin. Therefore, attempts have been made to blend such 1,2-polybutadiene with various rubbers and synthetic resins to obtain a tougher polymer alloy.

[0003]

However, when conventional 1,2-polybutadiene having a high melting point of about 150 ° C. or more is simply blended with rubber or synthetic resin, the dispersion of 1,2-polybutadiene often occurs. There was a problem of becoming defective. On the other hand, there is a problem that a sufficient reinforcing effect cannot be obtained even when 1,2-polybutadiene having a low melting point of about 100 to 120 ° C. is blended with a different kind of polymer.

The present invention solves the above-mentioned problems of the conventional 1,2-polybutadiene resin and provides a method for producing a 1,2-polybutadiene composition having a high reinforcing effect on rubber and synthetic resins. It is intended for that purpose.

[0005]

The process for producing the polybutadiene composition of the present invention comprises a transition metal compound, an organic compound of a Group I-III metal, carbon disulfide, phenyl isothiocyanate, and a xanthate compound. When a butadiene monomer containing 1,3-butadiene as a main component is subjected to suspension polymerization in a polymerization system containing water in the presence of a catalyst containing at least one of the above-mentioned polymerization systems, after the initiation of the polymerization, Inside, ketones, aliphatic aldehydes, alcohols, esters, nitriles, sulfoxides,
The above-mentioned polymerization is carried out while adding a melting point modifier consisting of at least one compound selected from amides and phosphoric acid esters at one time, or dividing it into two or more times, or adding continuously, A process for producing a polybutadiene composition thereby consisting essentially of two or more polybutadiene components having mutually different melting points, but both having a 1,2-structure as main structure. In the method for producing a polybutadiene composition of the present invention, the melting point difference between the highest melting point 1,2-polybutadiene component and the lowest melting point 1,2-polybutadiene component among the two or more kinds of polybutadiene components having different melting points from each other. Preferably it is 20 to 125 ° C. In the method for producing a polybutadiene composition of the present invention, each of the two or more polybutadienes is preferably 1,2-polybutadiene substantially having a syndiotactic 1,2-structure. Further, in the polybutadiene composition of the present invention, the two but having different melting points may be used.
The melting point of the component having the highest melting point among the polybutadiene components is preferably 155 ° C. or higher.
In the polybutadiene composition of the present invention, the content of the component having the highest melting point among the two or more polybutadiene components is 5 to 6 with respect to the total weight of the composition.
Preferably it is 5% by weight. In the polybutadiene composition of the present invention, it is preferable that the component having the highest melting point among the two or more polybutadiene components is dispersed in a matrix composed of other components. In the polybutadiene composition of the present invention, it is preferable that the dispersed polybutadiene component having the highest melting point has a shape of particles, scales, flakes, and / or short fibers.

[0006]

In the composition obtained by the method for producing a polybutadiene composition of the present invention, two or more components thereof are two or more polybutadienes having a 1,2-structure as a main structure (hereinafter referred to as 1,2-polybutadiene). ), The total content of which is preferably at least 90% by weight, more preferably at least 95% by weight, based on the total weight of the composition. The polybutadiene composition obtained by the method of the present invention contains 10% by weight or less, preferably 5% by weight or less of cis 1,4-polybutadiene or trans 1,4-
Polybutadiene other than 1,2-polybutadiene such as polybutadiene, and polyisoprene and a polymer derived from impurities contained in a 1,3-butadiene monomer subjected to polymerization such as polybutene may be contained. Good.

The 1,2-polybutadiene as a component constituting the polybutadiene composition obtained by the method of the present invention may be 1,2-polybutadiene substantially having a syndiotactic 1,2-structure. More preferably, the total content of the syndiotactic 1,2-structure is preferably at least 75 mol%, more preferably at least 80 mol%. When the proportion of the syndiotactic 1,2-structure is less than 75 mol%, the melting point of the obtained 1,2-polybutadiene component is as low as 100 ° C. or less, and the rubber-like properties may be strongly exhibited. is there. When such a rubbery 1,2-polybutadiene is blended with a rubber or a synthetic resin, its reinforcing effect is low and may not be practical. However, when the content of the syndiotactic 1,2-structure is 75 mol% or more,
If it is polybutadiene, syndiotactic 1,2-
In addition to the structure, an atactic 1,2-structure, an isotactic 1,2-structure, a cis 1,4-structure, and / or a trans 1,4-structure may be included. The molecular structure of 1,2-polybutadiene can be identified by an infrared absorption method such as the Morero method, ¹ H-NMR, ¹³ C-NMR, or the like. It is also known that there is a certain relationship between the content of the syndiotactic 1,2-structure in 1,2-polybutadiene and the melting point of the obtained polymer. It is considered that the composition containing 1,2-polybutadiene hardly changes. Therefore, a calibration curve indicating the relationship between the ratio of the syndiotactic 1,2-structure and the melting point was prepared in advance, and the calibration curve was determined from the melting point of 1,2-polybutadiene in the composition obtained from the DSC chart. Syndiotactic 1, using lines
2- The content of the structure can be determined.

Among the two or more 1,2-polybutadiene components contained in the polybutadiene composition obtained by the method of the present invention, 1,2-polybutadiene having the highest melting point (hereinafter referred to as 1,2-polybutadiene having a high melting point) The content of the component) is preferably in the range of 5 to 65% by weight, more preferably 20 to 54% by weight, based on the total weight of the composition. Compositions containing less than 5% by weight of the high melting point 1,2-polybutadiene component, and compositions containing more than 65% by weight, can be blended with rubber or synthetic resin to obtain a conventional 1,1 polybutadiene component. In some cases, almost the same unsatisfactory reinforcing effect as that of 2-polybutadiene can be obtained. The melting point of the high melting point 1,2-polybutadiene component in the composition is preferably 155 ° C. or higher, more preferably 165 ° C., even more preferably 175 ° C. to 230 ° C.
It is. The melting point of the high melting point 1,2-polybutadiene component is 1
If the temperature is lower than 55 ° C., even if this is blended with a rubber or a synthetic resin, an unsatisfactory reinforcing effect equivalent to that of the conventional 1,2-polybutadiene may be obtained. Further, among the polybutadiene components in the polybutadiene composition obtained by the method of the present invention, the melting point of the component having the lowest melting point (hereinafter referred to as low melting point 1,2-polybutadiene) is as follows:
105 ° C. or higher, but preferably lower than 155 ° C. 1,2-polybutadiene having a melting point lower than 105 ° C. generally has a syndiotactic 1,2-structure content of less than 75 mol%, strongly exhibits properties as an elastomer, and does not exhibit a sufficient reinforcing effect. Sometimes. In the polybutadiene composition obtained by the method of the present invention, a high melting point 1,2-polybutadiene component and a low melting point 1,2
The difference in melting point from the 2-polybutadiene component is preferably 20
To 125 ° C, more preferably 30 to 125 ° C.

The melting point of each 1,2-polybutadiene component in the polybutadiene composition and the content of the high-melting 1,2-polybutadiene can be determined, for example, from a DSC chart. When a DSC chart is measured for the composition of the present invention, usually, two or more endothermic peaks are observed, or a broad endothermic peak appears. Among these endothermic peaks, the temperature corresponding to the high-temperature peak is defined as the melting point of the high-melting 1,2-polybutadiene component, and the temperature corresponding to the low-temperature peak is defined as the melting point of the low-melting 1,2-polybutadiene. Can be. Then, the content ratio of the high melting point 1,2-polybutadiene component and the low melting point 1,2-polybutadiene component can be determined from the area ratio between the high temperature side peak and the low temperature side peak. Further, 1,2-polybutadiene having a melting point of less than 155 ° C. has a property of being soluble in various organic solvents such as toluene, but 1,2-polybutadiene having a melting point of 190 ° C. or more hardly dissolves in toluene. By utilizing this fact, the content of the high-melting 1,2-polybutadiene component in the polybutadiene composition can be determined.

In the polybutadiene composition obtained by the method of the present invention, the high-melting 1,2-polybutadiene component is finely dispersed in a matrix composed of a 1,2-polybutadiene component having a lower melting point. preferable. More specifically, a high melting point 1,2-polybutadiene component is contained in a matrix composed of other components (consisting substantially of a polymer having a lower melting point) in the form of particles, scales, flakes, and / or the like. Alternatively, it is preferable that the particles are dispersed in a short fiber form. And, when dispersed in the form of particles, scales, and / or flakes, the major axis is preferably 10 μm to 0.01 μm,
More preferably, it is in the range of about 2 μm to 0.01 μm, and still more preferably about 1 to 0.1 μm. In addition, high melting point 1,2
When the polybutadiene component is dispersed in the form of short fibers, the short fibers preferably have a fiber diameter of 1 μm to 0.01 μm, more preferably about 1 to 0.1 μm, and have an aspect ratio ( Fiber length / fiber diameter) is 1 to 1
It is preferably in the range of 0.000. High melting point 1,
If the major axis of the particles of the 2-polybutadiene component, scales or flakes exceeds 10 μm, the particles of the high-melting 1,2-polybutadiene instead act as defective dispersoids,
When the resulting composition is blended with rubber or synthetic resin, a sufficient reinforcing effect may not be obtained. The dispersed shape of the high-melting 1,2-polybutadiene is obtained by extracting the lower-melting 1,2-polybutadiene component in the polybutadiene composition using, for example, toluene as a solvent, and observing the shape of the remaining component with an electron microscope. Can be identified. The polybutadiene composition of the present invention is characterized by having a melting point different from each other, but substantially consisting of two or more kinds of polybutadiene components each having a 1,2-structure as a main structure. In the polybutadiene composition of the present invention, each of the polybutadiene is substantially syndiotactic 1,2-
Preferably it is polybutadiene. In the polybutadiene composition of the present invention, the component having the highest melting point among the two or more polybutadiene components having different melting points preferably has a melting point of 155 ° C. or higher. In the polybutadiene composition of the present invention, the content of the component having the highest melting point among the two or more polybutadiene components is based on the total weight of the composition.
It is preferably from 5 to 65% by weight. In the polybutadiene composition of the present invention, it is preferable that the component having the highest melting point among the two or more polybutadiene components is dispersed in a matrix composed of other components. In the polybutadiene composition of the present invention, it is preferable that the dispersed high-melting-point polybutadiene component has a shape of particles, scales, flakes, and / or short fibers. Further, the method of the present invention for producing the polybutadiene composition comprises a transition metal compound, an organic compound of a Group I to III metal, and carbon disulfide, and at least one selected from phenyl isothiocyanate and a xanthate compound. In the presence of a catalyst, when a butadiene monomer containing 1,3-butadiene as a main component is subjected to suspension polymerization in a polymerization system containing water, after the start of the polymerization, ketone, aldehyde, The method is characterized in that a melting point modifier comprising at least one compound selected from alcohol, ester, nitrile, sulfoxide, amide, and phosphate is added once or divided into two or more portions. is there. Further, another method of the present invention for producing the polybutadiene composition includes a transition metal compound, an organic compound of a Group I to III metal, carbon disulfide, and at least one compound selected from phenyl isothiocyanate and a xanthate compound. When a butadiene monomer containing 1,3-butadiene as a main component is subjected to suspension polymerization in a polymerization system containing water, ketones, aldehydes, alcohols, esters, nitriles are contained in the polymerization system. ,
The method is characterized in that the polymerization is carried out while continuously adding a melting point regulator comprising at least one compound selected from sulfoxides, amides and phosphoric esters.

The above polybutadiene composition can be produced by the production method (1) or (2) of the present invention.

In the method of the present invention, the transition metal compound, I
1,3 in the presence of a polymerization catalyst containing an organic compound of a Group III metal and at least one selected from carbon disulfide, phenyl isothiocyanate and a xanthate compound.
When a butadiene monomer containing butadiene as a main component is subjected to suspension polymerization in a polymerization system containing water, a ketone,
After the initiation of the polymerization, the melting point regulator comprising at least one compound selected from aldehydes, alcohols, esters, nitriles, sulfoxides, amides, and phosphates is divided into the polymerization system once or twice or more. The 1,2-polybutadiene composition can be obtained by performing the polymerization while continuously adding the compound to the polymerization system or by continuously adding it to the polymerization system. When a melting point modifier is added to the polymerization system, 1,2-polybutadiene having a low melting point is produced,
It is known that 1,2-polybutadiene having a lower melting point can be obtained by increasing the amount of the melting point modifier.

The polybutadiene composition of the present invention can be produced by a solution polymerization method. However, the suspension polymerization method and the emulsion polymerization method are preferably used because the average degree of polymerization of the polybutadiene composition can be increased, and the heat of polymerization can be easily removed and the operation is easy and the safety is high. Hereinafter, the method for producing the polybutadiene composition of the present invention by the suspension polymerization method will be described in detail.

The polymerization system used in the method of the present invention may be, for example, a material obtained by dissolving or dispersing an inorganic salt such as calcium chloride, a dispersant such as polyvinyl alcohol, and, if necessary, a surfactant in water. Those usually used in suspension polymerization are preferably used. The proportion of the dispersant is
The range is preferably 0.01 to 1 part by weight with respect to 100 parts by weight of water. The proportion of water is preferably in the range of 1 to 30 mol per 1 mol of 1,3-butadiene. The generation of coarse particles can be suppressed by coexisting an inert organic solvent having a high specific gravity of 1.1 (20 ° C.) or more in the polymerization system. Here, the inert organic solvent refers to an organic solvent that does not react with 1,3-butadiene or each component of the catalyst, and for example, methylene chloride, carbon tetrachloride, or the like is suitably used.

As the catalyst, transition metal compounds, I to III
Organic compounds of group metals and at least one compound selected from the group consisting of carbon disulfide, phenyl isothiocyanate and xanthate compounds (hereinafter referred to as "catalyst component such as carbon disulfide") Used.
The transition metal compound is based on 1 mol of 1,3-butadiene,
It is preferable that the transition metal atom is used in a range of 0.01 to 0.00001 mol. Transition metal compound 1
The proportion of the organic compound of the group I-III metal used per mole is preferably in the range of 0.1 to 500 mol. The amount of the catalyst component such as carbon disulfide is preferably at least equimolar to the transition metal atom.

As the transition metal compound, a salt or complex of cobalt, titanium, or nickel is preferably used. Particularly preferred are cobalt salts such as cobalt chloride, cobalt bromide, cobalt nitrate, cobalt octylate, cobalt naphthenate, cobalt acetate, cobalt malonate, and bisacetylacetonate, trisacetylacetonate, and acetoacetic acid of cobalt. Organic base complexes such as triarylphosphine complexes and trialkylphosphine complexes of ethyl ester cobalt and cobalt halide, or pyridine complexes and picoline complexes of transition metals;
Alternatively, an ethyl alcohol complex may be used.

As the organic compound of the group I-III metal, an organic lithium compound, an organic magnesium compound, an organic aluminum compound and the like are used. Of these compounds, particularly preferred are trialkylaluminum, dialkylaluminum chloride, dialkylaluminum bromide, alkylaluminum sesquichloride, and alkylaluminum sesquibromide.

The monomers used in the method of the present invention include:
Although those having 1,3-butadiene as a main component can be used, in addition to 1,3-butadiene, a small amount (10 mol% or less) of conjugated dienes such as isoprene, chloroprene, and myrcene, ethylene, propylene, An olefin such as butene-1, butene-2, isobutene, and pentene-1 and / or an aromatic vinyl compound such as styrene and α-methylstyrene may be contained.

The following may be mentioned as alcohols, aliphatic aldehydes, ketones, esters, nitriles, sulfoxides, amides and phosphates used as melting point regulators added to the polymerization system. These compounds may have one functional group, or may have two or more functional groups.

Alcohols used as melting point regulators include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, and tert-butyl alcohol.
Aliphatic alcohols such as butyl alcohol, pentyl alcohol, hexanol and octanol; alicyclic alcohols such as cyclobutanol, cyclopentanol, cyclohexanol and cyclododecanol; benzyl alcohol; diphenylcarbinol; cinnamyl alcohol; o-anis alcohol , M-anis alcohol, p
-An aromatic alcohol such as anis alcohol is preferably used. Also, diols such as ethylene glycol and propylene glycol, and polyhydric alcohols such as glycerin are preferably used.

Examples of the ketone include acetone, acetylacetone, methyl ethyl ketone, methyl propyl ketone, isopropyl methyl ketone, butyl methyl ketone,
Aliphatic ketones such as isobutyl methyl ketone, pinacolone, diethyl ketone, butyrone, diisopropyl ketone and diisobutyl ketone, and alicyclic ketones such as cyclobutanone, cyclopentanone, cyclohexanone and cyclododecanone, acetophenone, propiophenone, butyrophenone and valerophenone And aromatic ketones such as benzophenone, dibenzyl ketone and acetonaphthone. Diketones and the like are also used. Aliphatic aldehydes include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, valeraldehyde, isovaleraldehyde, pivalinaldehyde, caproaldehyde, heptaldehyde, capryaldehyde, pelargonaldehyde, caprinaldehyde, undecylaldehyde, laurin Aldehydes, tridecylaldehyde, myristic aldehyde, pentadecylaldehyde, palmitaldehyde,
An aliphatic monoaldehyde such as stearyl aldehyde and an aromatic aldehyde such as an aliphatic dialdehyde such as glyoxal and succinaldehyde are used.

Examples of the ester include acetate, propionate, butyrate, valerate, caproate, enanthate, caprylate, pelargonate, undecylate,
And unsaturated fatty acid esters such as crotonic acid esters, isocrotonic acid esters, undecylenic acid esters, and oleic acid esters; aromatic carboxylic acid esters such as benzoic acid esters and phenylacetic acid esters; and keto such as acetoacetic acid esters. Acid esters and the like are used.

As the nitrile, a general formula RCN (provided that
R represents an organic group). Such compounds include, for example, acetonitrile, benzonitrile, acrylonitrile, propionitrile and the like.

As the sulfoxide, R ₁ R ₂ S ＝ O
(Wherein, R ₁ and R ₂ each represent an organic group). Such compounds include dimethylsulfoxide, diethylsulfoxide,
Examples thereof include di-n-propylsulfoxide, di-n-butylsulfoxide, diisoamylsulfoxide, di-n-heptylsulfoxide, divinylsulfoxide, diallylsulfoxide, diphenylsulfoxide, dibensylsulfoxide, and methylallylsulfoxide.

As the amide, a compound represented by the general formula consisting of R ₃ R ₄ NCOR ₅ (where R ₃ , R ₄ and R ₅ each represent a hydrogen atom or an organic group) is used.
Examples of such a compound include N-methylformamide, N-ethylformamide, N-propylformamide, N, N-dimethylformamide, N, N-diethylformamide, N, N-dipropylformamide,
-Methylacetamide, N-ethylacetamide, N,
Use of N-dimethylacetamide, N, N-diethylacetamide, N, N-dipropylacetamide, N-methylformanilide, N-ethylformanilide, N, N-diphenylformamide, N, N-diphenylformanilide and the like Can be. In addition, propiolactam, butyrolactam, valerolactam, caprolactam, N-methylpyrrolidone, N-ethylpyrrolidone, N
Cyclic amides such as -phenylpyrrolidone can also be used.

The phosphoric ester is represented by the general formula (R ₆ O)
₃ PO, or _{(R 7 O) (R 8} O) 2 PO, or _{(R 9 O) (R 10} O) (R 11 O) PO ( where, R _6, R
₇ , R ₈ , R ₉ , R ₁₀ and R ₁₁ each represent an organic group)
The compound shown by is used. Examples of such a material include trimethyl phosphate, triethyl phosphate, tributyl phosphate, tri-p-methylphenyl phosphate, and the like.

A high specific gravity inert organic solvent used in the polymerization system of the present invention may be contained. Such organic solvents include, for example, halogenated aliphatic hydrocarbons such as methylene chloride, carbon tetrachloride, chloroform, bromoform, and trichlene, chlorobenzene, bromobenzene, chlorotoluene, dichlorobenzene, dibromobenzene, hexachlorobenzene, and hexafluorobenzene. And halogenated aromatic hydrocarbons such as chlorophenol, bromophenol, pentachlorophenol, halogenated phenol compounds such as pentabromophenol, sulfoxides such as dimethyl sulfoxide, and sulfuric acid diesters such as dimethyl sulfate and diethyl sulfate. Used. Among them, it is particularly preferable to use a halogenated hydrocarbon in that there is almost no effect of lowering the melting point of 1,2-polybutadiene. The content of high specific gravity organic solvent is
10 to 100 parts of 1,3-butadiene in the polymerization system
100 volumes, preferably 20-80 volumes, particularly preferably 4
It is in the range of 0 to 60 volumes. If the ratio of the high specific gravity inert organic solvent to 100 volumes of 1,3-butadiene exceeds 100 volumes, the productivity of the polybutadiene composition may decrease, which is not preferable. May be easily generated.

The polybutadiene composition of the present invention can be produced, for example, according to the following procedure.

First, 1,3-butadiene, isoprene,
And / or aging by contacting a conjugated diene such as myrcene with a transition metal compound and an organometallic compound. The aging temperature is-
A range from 60 to 50 ° C is preferred. This aging may be performed in a solvent such as a hydrocarbon solvent such as toluene, benzene, xylene, n-hexane, mineral spirit, solvent naphtha, or kerosene, or a halogenated hydrocarbon solvent such as methylene chloride. However, these solvents include conjugated dienes, transition metal compounds,
It is preferable to use one that does not react with the organometallic compound.

The aging solution obtained in the aging step is then dispersed in the polymerization system. The organic solvent having a high specific gravity may be dispersed in the polymerization system in advance, or may be previously mixed with the aging solution. Further, after the aging solution is added to the polymerization system, an organic solvent having a high specific gravity may be added.

After dispersing the aging solution, a catalyst component such as carbon disulfide is added to the polymerization system, and polymerization is started. The catalyst component such as carbon disulfide may be dispersed in the polymerization system in advance, may be added together with a high specific gravity organic solvent, or may be added after adding a high specific gravity organic solvent. The polymerization temperature is preferably in the range of 0 to 100C, more preferably in the range of 10 to 50C. This is because the polybutadiene composition obtained by polymerization at a temperature in this range has an excellent reinforcing effect on rubber, synthetic resin, and the like.

In the method (1) of the present invention, the above-mentioned melting point modifier comprising alcohol, aldehyde, ketone, ester and the like is added to the polymerization system once or in two or more portions after the initiation of polymerization. . However, it is preferable to perform the first addition at least 30 seconds after the start of the polymerization. When adding in two or more portions after the initiation of polymerization, the same type of melting point regulator may be added each time, or a different type of melting point regulator may be added each time. Also,
In the case of divided addition in two or more times, it is preferable to perform the next addition at least 30 seconds after the previous addition. In the method (1) of the present invention, a part of the melting point regulator may be previously added to the polymerization system, and the remainder may be added as described above after the initiation of the polymerization. Also in this case, the melting point regulator added after the initiation of the polymerization may be the same as or different from the melting point regulator added to the polymerization system in advance. The addition of the melting point regulator after the initiation of the polymerization is preferably performed at least 30 seconds after the initiation of the polymerization.
In the methods (1) and (2) of the present invention, the total amount of the melting point modifier to be added to the polymerization system is 1,3-
It is preferably 20 to 400 ml for a total volume of 1000 ml of butadiene, water and a high specific gravity inert organic solvent. Further, water is preferably used in an amount of 300 to 800 ml based on a total volume of 1,000 ml of 1,3-butadiene, water and a high specific gravity inert organic solvent in the polymerization system. In the above method (1) of the present invention, the addition of the melting point regulator is preferably performed at the following timing. (1) In the case where the melting point modifier is added only after the initiation of the polymerization, the conversion to 1,2-polybutadiene is 5 after the initiation of the polymerization.
Make the first addition when ~ 65% is reached. For example, (batch type, polymerization time: 1 hour) First addition: performed when 30 seconds to 20 minutes have elapsed from the start of polymerization. Addition from the second time onward: complete within 35 minutes from the start of polymerization. Is preferred. (2) A part of the melting point regulator is previously added to the polymerization system, or mixed with a catalyst component such as carbon disulfide in the polymerization system, and the remaining melting point regulator is added after the initiation of the polymerization. After the start of the polymerization, the conversion to 1,2-polybutadiene is 5
When ~ 65% is reached, the first addition is made. For example, (batch type, polymerization time: 1 hour) First addition: performed when 30 seconds to 20 minutes have elapsed from the start of polymerization. Addition from the second time onward: Completed within 35 minutes from the start of polymerization. Is preferred. In the method (2) of the present invention, the melting point modifier may be continuously added to the polymerization system during the polymerization. In this case: The addition of the melting point modifier may be started at the same time as the start of the polymerization, and may be continuously performed. Alternatively, the addition of the melting point modifier may be continuously performed only for a part of the period during which the polymerization is performed, or over the entire period.

[0033]

The present invention is further described by the following examples. In the following examples, the following characteristics were measured. [Measurement method] (1) Melting point The melting point of each 1,2-polybutadiene in the polybutadiene compositions obtained in Examples and Comparative Examples was determined from a DSC chart, and the temperature corresponding to the endothermic peak was defined as the melting point. D
SC was measured using a SSC5200 manufactured by Seiko Denshi Kogyo KK under a nitrogen atmosphere under the conditions of a sample amount of 10 mg and a heating rate of 10 ° C./min. (2) Content of syndiotactic 1,2-structure The content of syndiotactic 1,2-structure in each 1,2-polybutadiene component in the polybutadiene compositions obtained in Examples and Comparative Examples is as follows. It was measured as follows. First, in the range from melting point 100 ° C. to 210 ° C., for each of the different 1,2-polybutadiene component having a melting point, and measuring the ¹ H-NMR, to determine the content of 1,2-structure from the peak area. Further, it was confirmed by ¹³ C-NMR that most of the 1,2-structure had a syndiotactic structure. Plot this result on a graph,
The calibration curve was used. This calibration curve is shown in FIG. ¹ H-NMR
And ¹³ C-NMR were measured by FX manufactured by JEOL Ltd.
-200 was used, and o-dichlorobenzene was used as a solvent. The polybutadiene compositions obtained in the examples and the comparative examples have high melting points of 1,2.
The melting points of the polybutadiene component and the low-melting 1,2-polybutadiene component were determined, and then using the calibration curve of FIG. 2- The content of the structure was determined. (3) Content of high melting point 1,2-polybutadiene component A 2 g sample was taken from the polybutadiene composition obtained in each of the examples and comparative examples, wrapped in a 250-mesh wire net, and dissolved in toluene at a temperature of 80 to 90 ° C. For 1 hour,
The toluene-soluble portion was extracted. Anti-aging agent for toluene
What melted Irganox 1076 was used. The polybutadiene composition from which the toluene-soluble part was extracted was immersed again in fresh toluene for 30 minutes, and the toluene-soluble part was extracted at a temperature of 80 to 90 ° C. After extracting the toluene-soluble part,
The remaining insoluble portion was immersed in cyclohexane overnight and freeze-dried. DS for insoluble part after lyophilization
C was measured and it was confirmed that this was a high melting point 1,2-polybutadiene. The amount of the insoluble portion after lyophilization was defined as the amount of the high melting point 1,2-polybutadiene, and the content of the high melting point 1,2-polybutadiene component was determined from this amount. For the toluene solution containing the toluene-soluble part after extraction,
The total amount of the product obtained in the first extraction and the second extraction was collected, acetone was added thereto to reprecipitate 1,2-polybutadiene, and the precipitated 1,2-polybutadiene was separated by filtration.
Collected and vacuum dried at 60 ° C. overnight. The DSC of the toluene-soluble portion thus obtained was measured in the same manner, and it was confirmed that it was a low-melting 1,2-polybutadiene. Next, this weight was defined as the content of the low-melting 1,2-polybutadiene component, and the content of the high-melting 1,2-polybutadiene was determined from this amount. (4) Molecular weight The polybutadiene compositions obtained in Examples and Comparative Examples were
-Dissolved in dichlorobenzene and the molecular weight was measured using GPC (gel permeation chromatography). The measurement was performed at a temperature of 135 ° C. using o-dichlorobenzene as an eluent for GPC. As a standard substance, a molecular weight of 2.89 × 10 ⁶ ,
7.75 × 10 ⁵ , 1.90 × 10 ⁵ , 35,000,
Eighteen standard polystyrenes of 17,500, 4,000, 580, and 418 were used.

Example 1 [Preparation of Aging Solution] A 300 ml autoclave filled with nitrogen in advance was supplied with 240 ml of a butadiene monomer, and a heptane solution of cobalt octanoate (0.5 mol of cobalt octanoate / l liter of heptane) was used. 6 ml were added, and 2.4 ml of a solution of triethylaluminum in heptane (1 mol of triethylaluminum / 1 l of heptane) was further added. The cobalt to aluminum atomic ratio was 1: 3. Then, the mixture was stirred at room temperature with a stirrer at a rotation speed of 5.
The mixture was stirred at 00 rpm for 10 minutes to prepare an aging solution. [Polymerization] The inside of a 1.5-liter autoclave having an anchor-type stirring blade was purged with nitrogen, and 560 ml of ion-exchanged water and 120 ml of methylene chloride, which had been subjected to nitrogen bubbling, and polyvinyl alcohol (hereinafter referred to as "PVA") 0. .
A solution in which 56 g was dissolved in 40 ml of ion-exchanged water was fed. Add the aging solution to this, 10 ° C, 600 rpm
After stirring for 10 minutes, 1.6 mmol of carbon disulfide was added to initiate polymerization. The polymerization was carried out at 30 ° C. and the number of revolutions of the stirring blade was 60.
It was performed at 0 rpm. 2.5 minutes after the start of polymerization, acetone 35
ml (0.48 mol) was added. One hour after the start of the polymerization, the resulting particulate polybutadiene composition was filtered off,
After being immersed in a 1% methanol solution of BHT (butylated hydroxytoluene), it was dried in a vacuum dryer at 50 ° C. overnight. The resulting polybutadiene composition was 190.5
C. and 150.7.degree. C. DSC
The chart is shown in FIG. The yield was 90.9%.
The content of the high melting point 1,2-polybutadiene component is 23.
% By weight, the content of the low-melting 1,2-polybutadiene component was 77% by weight. ¹ H-NMR was measured on the obtained polybutadiene composition, and the content of the syndiotactic 1,2-structure of the entire composition was calculated from the chart. As a result, 88.9 mol of the entire polybutadiene composition was obtained.
%Met. Table 1 shows the test results. On the other hand, the content of the syndiotactic 1,2-structure determined from the calibration curve of FIG. 1 is 92.8 for the high-melting 1,2-polybutadiene component.
%, 87.5% for the low melting point 1,2-polybutadiene component
Met. High melting point 1,2-polybutadiene and low melting point 1,
Syndiotactic 1,2-polybutadiene
From the polybutadiene content, the high melting point 1,2-polybutadiene content in the polybutadiene composition, and the low melting point 1,2-polybutadiene content, the syndiotactic 1,2-polybutadiene in the entire polybutadiene composition; When the content was determined, 92.8 mol% × 0.23 + 87.5 mol% × 0.77
= 88.7 mol%, and the measured value obtained from the ¹ H-NMR chart was 88.
This showed a very good agreement with 9 mol%. A 1,2-vinyl structure of high and low melting 1,2-polybutadiene components,
Table 2 shows the content of the 1,4-cis structure. The structures of this polybutadiene composition before and after toluene extraction were photographed by electron microscopy. FIGS. 2 and 3 (enlarged) show electron micrographs of cross sections of the polybutadiene composition before extraction with toluene, and FIGS. 4 and 5 (enlarged) show electron micrographs of cross sections of the polybutadiene composition after extraction with toluene. Cross-sectional photographs of the polybutadiene composition before and after extraction (FIG. 2)
Comparison of (5) to (5) shows that in the polybutadiene composition after toluene extraction, a toluene-insoluble part, that is, a high-melting 1,2-polybutadiene component remains, which is dispersed in a small piece or scale shape. About this polybutadiene composition
^{When 13} C-NMR was measured, almost no peak corresponding to the vinyl group was found except for the peak corresponding to the syndiotactic 1,2-structure. As a structure other than the syndiotactic 1,2-structure, a cis-1,4-structure was mainly used.

Example 2 Polymerization was carried out in the same manner as in Example 1 except that the time when acetone was added to the polymerization system was 5 minutes after the start of polymerization. The resulting particles of the polybutadiene composition are
And then dried in a vacuum dryer at 50 ° C. for 24 hours. The resulting polybutadiene composition had two melting points, 190.4 ° C and 149.3 ° C. The yield of this polybutadiene composition is 92.3%.
Met. The content of the high melting point 1,2-polybutadiene component was 42% by weight. This polybutadiene composition,
^It was subjected to ¹ H-NMR measurement, and the content of the 1,2-structure was determined from the obtained ¹ H-NMR chart. 1,2
The structure content was 87.4 mol%, based on the total weight of the polybutadiene composition; The content of the 1,2-structure in the high melting point 1,2-polybutadiene component and the low melting point 1,2-polybutadiene component was determined from the calibration curve of FIG. The content of the 1,2-structure in the high melting point 1,2-polybutadiene component was 92.7 mol%, and the content of the 1,2-structure in the low melting point 1,2-polybutadiene component was 87.2 mol%. %Met. Next, the content of the 1,2-structure was determined using the high melting point of 1,2.
Calculated as follows from those of the polybutadiene component and the low-melting 1,2-polybutadiene component. 92.7% × 0.42 + 87.2% × 0.58 = 89.
5% Calculated content of 1,2-structure obtained 89.5 mol%
Was very close to the measured actual content of 87.4 mol% determined from the ¹ H-NMR chart. Next, this polybutadiene composition was subjected to ¹³ C-NMR measurement. In the obtained ¹³ C-NMR chart, most of the peaks corresponding to the vinyl group were syndiotactic 1,2-
Corresponding to the structure, and syndiotactic 1,2-
1,2-structures other than the structure, for example, atactic 1,2-
It was found that no peak corresponding to the structure or the isotactic 1,2-structure was observed. It was found that peaks other than the peak corresponding to the 1,2-structure corresponded to the cis-1,4-structure. Table 1 and Table 2 show the test results.
Shown in

Example 3 Polymerization was carried out in the same manner as in Example 1 except that the amount of acetone was changed to 100 ml. After immersing the resulting polybutadiene composition particles in a 1% methanol solution of BHT,
It was dried in a vacuum dryer at 50 ° C. overnight. The resulting polybutadiene composition had two melting points, 194.6 ° C. and 125.9 ° C., and the yield was 86.5%. This polybutadiene composition was subjected to ¹ H-NMR measurement, and the content of the 1,2-structure was measured for the obtained ¹ H-N
It was determined from the MR chart. The content of the 1,2-structure was 86.5 mol% based on the total amount of the polybutadiene composition. The content of the 1,2-structure in the high melting point 1,2-polybutadiene component and the low melting point 1,2-polybutadiene component was determined from the calibration curve of FIG. The content of the 1,2-structure in the high melting point 1,2-polybutadiene component was 94.2% by mole, and
The content of the structure was 79.0 mol%. Next, this polybutadiene composition was subjected to ¹³ C-NMR measurement. In the obtained ¹³ C-NMR chart, most of the peaks corresponding to the vinyl group were syndiotactic 1,2-
Corresponding to the structure, and syndiotactic 1,2-
1,2-structures other than the structure, for example, atactic 1,2-
It was found that no peak corresponding to the structure or the isotactic 1,2-structure was observed. It was found that peaks other than the peak corresponding to the 1,2-structure corresponded to the cis-1,4-structure. Table 1 and Table 2 show the test results.
Shown in

Example 4 Polymerization was carried out in the same manner as in Example 3 except that the time when acetone was added to the polymerization system was 5 minutes after the start of polymerization. The resulting particles of the polybutadiene composition were immersed in a 1% methanol solution of BHT, and then dried at 50 ° C. in a vacuum dryer for 24 hours. The resulting polybutadiene composition had two melting points, 191.6 ° C and 123.4 ° C, and the yield was 90.7%. This polybutadiene composition was subjected to ¹ H-NMR measurement, and 1,2-
The content of the structure was determined from the obtained ¹ H-NMR chart. The content of the 1,2-structure was 85.8 mol% based on the total amount of the polybutadiene composition. High melting point 1,2-
The content of the 1,2-structure in the polybutadiene component and the low-melting 1,2-polybutadiene component was determined from the calibration curve of FIG. 1,2-polybutadiene component of high melting point
The content of the structure was 93.1 mol%,
The content of the 1,2-structure in the polybutadiene component was 79.
It was 5 mol%. Next, this polybutadiene composition is
^It was subjected to ¹³ C-NMR measurement. In the obtained ¹³ C-NMR chart, most of the peaks corresponding to the vinyl group correspond to the syndiotactic 1,2-structure,
It was also found that no peak corresponding to a 1,2-structure other than the syndiotactic 1,2-structure, for example, an atactic 1,2-structure or an isotactic 1,2-structure was observed. It was found that peaks other than the peak corresponding to the 1,2-structure corresponded to the cis-1,4-structure. FIG. 6 is an electron micrograph of the whole polybutadiene composition particles of Example 4 before extraction with toluene. FIG.
7 is an enlarged photograph of a portion of the polybutadiene composition of FIG. FIG. 8 is an electron micrograph of the whole polybutadiene composition particles of Example 5 after extraction with toluene. FIG.
9 is an enlarged photograph of a portion of the polybutadiene composition of FIG. Comparing FIGS. 6 and 7 with FIGS. 8 and 9, it can be seen that the particle surface is smooth in FIGS. 6 and 7, whereas the particle surface is porous in FIGS. this is,
It can be seen that the low-melting 1,2-polybutadiene was removed from the particles by toluene extraction.

Example 5 The procedure of Example 1 was repeated except that 35 ml of acetone was added to the polymerization system 2.5 minutes after the start of the polymerization, and 65 ml of acetone was further added 5 minutes after the start of the polymerization. To perform polymerization. The particles of the resulting polybutadiene composition are represented by B
After being immersed in a 1% methanol solution of HT, it was dried at 50 ° C. in a vacuum dryer all day and night. The resulting polybutadiene composition had a temperature of 190.5 ° C, 148.4 ° C, and 124.
It had three melting points of 2 ° C. FIG. 11 shows the DSC chart. The yield of the polybutadiene composition was 90.4.
%Met. Table 1 shows the test results.

Example 6 The polymerization was carried out in the same manner as in Example 1 except that the addition of acetone was started 2 minutes after the start of the polymerization and the addition was continued at a rate of 3.3 ml / min for 30 minutes. Was done. The resulting polybutadiene composition particles were immersed in a 1% methanol solution of BHT, and dried at 50 ° C. in a vacuum dryer for 24 hours. The highest melting point of the obtained polybutadiene particles was 191.2 ° C., and the DSC curve had a plateau-like flat portion. FIG. 12 shows the DSC chart. The yield was 88.5%. Table 1 shows the test results.

Example 7 Polymerization was started in the same manner as in Example 1 except that 20 ml of acetone was added to the polymerization system before the start of polymerization. Five minutes after the start of polymerization, 80 ml of acetone was added to continue the polymerization. And
Polybutadiene particles were obtained. The yield of the polybutadiene composition was 90.5%. The resulting polybutadiene composition had two melting points, 159.9 ° C and 123.2 ° C. FIG. 13 shows the DSC chart. ¹ H-
The proportion of the syndiotactic 1,2-structure in the entire composition determined from the NMR spectrum was 82.5 mol%.
Table 1 shows the test results.

Example 8 Polymerization was started in the same manner as in Example 1 except that 15 ml of acetone was added to the polymerization system before the start of polymerization. Five minutes after the start of polymerization, 85 ml of acetone was added to continue the polymerization. And
A polybutadiene composition was obtained. The yield of the polybutadiene composition was 91.3%. The resulting polybutadiene composition had two melting points, 169.5 ° C and 122.8 ° C. The ratio of the syndiotactic 1,2-structure of the entire composition determined from the ¹ H-NMR spectrum was 83.
It was 2 mol%. Table 1 shows the test results.

[0042]

[Table 1]

[0043]

[Table 2]

[0044] natural rubber in each of Examples 9-12 Examples 9-12, Example 1,
The polybutadiene composition obtained in each of 2, 4, and 5, carbon black, sulfur, a vulcanization accelerator and the like were blended to prepare a rubber composition. The rubber composition was sheeted out and then vulcanized. The formulation and vulcanization conditions are shown below. (2) Kneading method: primary setting using a plast mill at 90 ° C. for 30 seconds NR winding—kneading for 4 minutes—160 ° C. dumping secondary setting using a 6-inch roll at 60 ° C., gap: 1 mm, winding for 1 minute—injection of filler—circling through—1. 5mm
Sheeting (3) Test items-Mooney viscosity ML _{1 ++} of the compound-Vulcanization conditions 145 ° C t90 × 3 (measured with a curast meter)-Tensile test (25 ° C, 100 ° C) 100, 200, 300% modulus Breaking strength TB, breaking elongation EB The obtained vulcanized rubber sheet was measured for 100% modulus, 200% modulus, 300% modulus, breaking strength and breaking elongation. Table 3 shows the test results of Examples 9 to 12. 14 and 15 show test results of Examples 9 and 10. From these results, Examples 1 to
It can be seen that the rubber composition containing the polybutadiene composition of No. 2 has a particularly high modulus and a high tensile strength. In addition, the increase in the Mooney viscosity ML of the blend due to the addition of the polybutadiene composition was small.

Comparative Example 1 A rubber composition was prepared and vulcanized in the same manner as in Example 9 except that 1,2-polybutadiene having a single melting point of 150 ° C. was used as the polybutadiene composition. Thus, a vulcanized rubber sheet was obtained. For the obtained vulcanized rubber sheet, 100% modulus, 200% modulus, 300%
The% modulus, breaking strength and breaking elongation were measured. The test results are shown in Tables 1 and 3, and FIGS. Table 3 shows the performance of natural rubber as a reference example.

Comparative Example 2 A rubber composition was prepared and vulcanized in the same manner as in Example 9 except that 1,2-polybutadiene having a single melting point of 193 ° C. was used as the polybutadiene composition. Thus, a vulcanized rubber sheet was obtained. For the obtained vulcanized rubber sheet, 100% modulus, 200% modulus, 300%
The% modulus, breaking strength and breaking elongation were measured. The test results are shown in Table 3, FIG. 14 and FIG.

Comparative Example 3 A polybutadiene composition was prepared by using a mixture of 42 parts by weight of 1,2-polybutadiene having a melting point of 193 ° C. and 58 parts by weight of 1,2-polybutadiene having a melting point of 150 ° C. A rubber composition was prepared and vulcanized in the same manner as in Example 9 to obtain a vulcanized rubber sheet. With respect to the obtained vulcanized rubber sheet, 100% modulus, 2
When the 00% modulus, the 300% modulus, the breaking strength and the breaking elongation were measured, it was found that each of the modulus was low. The test results are shown in Tables 1 and 3, and FIGS.

[0048]

[Table 3]

[0049] In each of Examples 13, 14 and 15 Examples 13, 14 and 15, Example 1
The same operation as was performed. However, the polymerization temperature was changed from 30 ° C. to 40 ° C., and the addition of acetone was performed 2 minutes (Example 13), 3 minutes (Example 14), and 7 minutes (Example 15) after the start of the polymerization. Was made. Table 4 shows the test results.

Comparative Example 4 The same operation as in Example 13 was performed. However, 35 ml of acetone were added to the polymerization mixture before the start of the polymerization. The resulting polymer was a single type of syndiotactic 1,2-polybutadiene and had a melting point of 150 ° C. Table 4 shows the test results.

[0051] In each of Examples 16 to 18 Examples 16 to 18 The operation was performed in the same manner as in Example 1. However, the polymerization temperature was changed from 30 ° C. to 10 ° C., and acetone was added one minute after the start of the polymerization (Example 1).
6) After 3 minutes (Example 17) and after 5 minutes (Example 1)
8). Table 4 shows the test results.

Comparative Example 5 The same operation as in Example 16 was performed. However, 35 ml of acetone was added to the polymerization mixture before the start of the polymerization. The resulting polymer is a single type of syndiotactic 1,2-
Polybutadiene having a melting point of 150 ° C. Table 4 shows the test results.

[0053]

[Table 4]

Examples 19 to 24 and Comparative Examples 6 and 7 Each of the polymers obtained in Examples 13 to 18 and Comparative Examples 4 and 5 was subjected to the same rubber composition preparation procedure as described in Example 9. And tested. Table 5 shows the test results.

[0055]

[Table 5]

[0056]

The polybutadiene composition obtained by the method of the present invention contains two or more kinds of 1,2-polybutadiene components having different melting points, and 1,2 having the highest melting point.
In many cases, the 2-butadiene component has a structure in which the 2-butadiene component is substantially uniformly dispersed in the polybutadiene component having a lower melting point. For this reason, when the polybutadiene composition obtained by the method of the present invention is blended with another rubber or a synthetic resin, 1,2-polybutadiene having a high melting point in the rubber or the synthetic resin is in the form of fine particles, scale, flake, Since the rubber composition is uniformly dispersed in a short fiber form, a rubber composition having particularly excellent modulus and elongation, or a high-strength polymer alloy can be obtained. When the polybutadiene obtained by the method of the present invention is injection-molded into a desired shape or formed into a film, an injection-molded product or film having excellent strength and impact resistance can be obtained. The method of the present invention can produce the above polybutadiene composition in high yield.

[Brief description of the drawings]

FIG. 1 is a calibration curve graph showing the relationship between the melting point of 1,2-polybutadiene and the content of a syndiotactic 1,2-structure.

FIG. 2 is an electron micrograph of a cross section of the polybutadiene composition of Example 1 before extraction with toluene.

FIG. 3 is an enlarged photograph of FIG. 2;

FIG. 4 is an electron micrograph of a cross section of the polybutadiene composition of Example 1 after extraction with toluene.

FIG. 5 is an enlarged photograph of FIG.

FIG. 6 is an electron micrograph of the whole particles of the polybutadiene composition of Example 4 before extraction with toluene.

FIG. 7 is an enlarged photograph of FIG. 6;

FIG. 8 is an electron micrograph of the whole particles of the polybutadiene composition of Example 4 after extraction with toluene.

FIG. 9 is an enlarged photograph of FIG.

FIG. 10 is a DSC chart of the polybutadiene composition of Example 1.

FIG. 11 is a DSC chart of the polybutadiene composition of Example 5.

FIG. 12 is a DSC chart of the polybutadiene composition of Example 6.

FIG. 13 is a DSC chart of the polybutadiene composition of Example 7.

FIG. 14 is a graph showing the relationship between the content of a high-melting 1,2-polybutadiene component in a polybutadiene composition and tensile strength in Examples 9 to 10 and Comparative Examples 1 to 3.

FIG. 15 shows Examples 9 to 10 and Comparative Examples 1 to
3, the high melting point 1,2-
The graph which shows the relationship between the content rate of a polybutadiene component, and 100% modulus.

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tomonori Suzuki 8-1 Goi-minamikaigan, Ichihara-shi, Chiba Ube Industries, Ltd. Chiba Research Institute (72) Inventor Kazuhiro Akikawa 8th Goi-minamikaigan, Ichihara-shi, Chiba 1 Ube Industries, Ltd. Chiba Research Institute (56) References JP-A-54-85270 (JP, A) JP-A-55-120611 (JP, A) JP-A-4-234402 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) C08F 36/06 C08F 2/18 C08F 2/38

Claims (7)

(57) [Claims] 1. The method according to claim 1, wherein the catalyst comprises a transition metal compound, an organic compound of a Group I to III metal, and a catalyst containing at least one selected from carbon disulfide, phenyl isothiocyanate and a xanthate compound. When butadiene monomer containing butadiene as a main component is subjected to suspension polymerization in a polymerization system containing water, after the initiation of the polymerization, in the polymerization system, ketone, aliphatic aldehyde, alcohol, ester, nitrile, sulfoxide, The above-mentioned polymerization is carried out while adding a melting point modifier consisting of at least one compound selected from amides and phosphoric acid esters at one time, or dividing it into two or more times, or adding continuously, Thereby, it consists essentially of two or more polybutadiene components having mutually different melting points, but both having a 1,2-structure as main structure Method of producing a re-butadiene composition. 2. A melting point difference between the highest melting point 1,2-polybutadiene component and the lowest melting point 1,2-polybutadiene component of the two or more kinds of polybutadiene components different in melting point from each other is 20 to 125 ° C. A method for producing the polybutadiene composition according to claim 1. 3. The 1,2-polybutadiene component wherein each of the polybutadiene components substantially comprises a syndiotactic 1,2-structure.
The method for producing a polybutadiene composition according to claim 2, which is a polybutadiene. 4. The melting point of the component having the highest melting point among the two or more polybutadiene components having different melting points is 1
The method for producing a polybutadiene composition according to claim 2, wherein the temperature is 55 ° C. or higher. 5. The composition according to claim 2, wherein the content of the component having the highest melting point among the two or more polybutadiene components is 5 to 65% by weight based on the total weight of the composition. 13. The method for producing a polybutadiene composition according to the above item. 6. The polybutadiene according to claim 2, wherein the component having the highest melting point among the two or more polybutadiene components is dispersed in a matrix composed of other components. A method for producing the composition. 7. The method for producing a polybutadiene composition according to claim 6, wherein the dispersed polybutadiene component having the highest melting point has a shape of particles, scales, flakes, and / or short fibers. .