JP2020132825A - Polybutadiene mixture and method for manufacturing the same - Google Patents

Abstract

To provide: a polybutadiene mixture that makes it possible to obtain a polybutadiene resin excellent in tensile strength, extension and toughness; and a method for manufacturing the polybutadiene mixture.SOLUTION: A polybutadiene mixture is manufactured with a method including the step Y of polymerizing 1,3-butadiene in the presence of 1,2-polybutadiene and a lanthanoid catalyst. A mass ratio of 1,2-polybutadiene and 1,3-butadiene is 1,2-polybutadiene/1,3-butadiene=95/5 to 50/50.SELECTED DRAWING: None

Description

The present invention relates to a polybutadiene mixture and a method for producing the same. More specifically, the present invention relates to a polybutadiene mixture containing 1,2-polybutadiene and 1,4-polybutadiene, and a method for producing the same.

The crystalline 1,2-polybutadiene resin is produced by a method of syndiotactic-1,2 polymerization of 1,3-butadiene in the presence of a catalyst in an inert solvent such as a hydrocarbon. The 1,2-polybutadiene resin having such crystallinity is used in various applications such as shoe sole materials and medical molded products. Further, in a resin material containing a 1,2-polybutadiene resin having crystallinity, attempts have been made to improve various properties required for each application (see, for example, Patent Document 1 and Patent Document 2).

In Patent Document 1, by blending a crystalline 1,2-polybutadiene resin and a specific polymer silicone compound in a specific ratio, the molded appearance is excellent, and flexibility, abrasion resistance, and mechanical strength characteristics are obtained. It is disclosed that an excellent thermoplastic elastomer is obtained. Further, in Patent Document 2, the adhesiveness to the polar resin is improved by blending a crystalline 1,2-polybutadiene resin and a specific styrene-conjugated diene compound block copolymer in a specific ratio. Is disclosed.

Japanese Unexamined Patent Publication No. 2004-217845 JP-A-2007-23062

In recent years, as consumers' awareness of resource saving, energy saving and safety has increased, resin materials with excellent tensile strength, elongation and toughness (tensile product) have been selected in order to improve the durability and wear resistance of products. It is desired to develop.

The present invention has been made in view of the above problems, and one object of the present invention is to provide a polybutadiene mixture capable of obtaining a polybutadiene resin having excellent tensile strength, elongation and toughness, and a method for producing the same.

In order to solve the above problems, the present invention provides the following polybutadiene mixture, a method for producing the same, and a molded product.

[1] A step Y of polymerizing 1,3-butadiene in the presence of 1,2-polybutadiene and a lanthanoid-based catalyst is included, and 1,2-polybutadiene and 1,3-butadiene during the polymerization of the step Y. A method for producing a polybutadiene mixture, wherein the mass ratio is 1,2-polybutadiene / 1,3-butadiene = 95/5 to 50/50.
[2] A polybutadiene mixture containing 1,2-polybutadiene and 1,4-polybutadiene, obtained by polymerizing 1,3-butadiene in the presence of 1,2-polybutadiene and a lanthanoid-based catalyst. , A polybutadiene mixture in which the mass ratio of 1,2-polybutadiene to 1,3-butadiene in the polymerization is 1,2-polybutadiene / 1,3-butadiene = 95/5 to 50/50.
[3] A molded product formed by using the polybutadiene mixture obtained by the production method of the above [1] or the polybutadiene mixture of the above [2].

According to the polybutadiene mixture of the present invention and the method for producing the same, a polybutadiene resin material having excellent tensile strength, elongation and toughness can be obtained.

Hereinafter, matters related to the aspects of the present disclosure will be described in detail. In addition, in this specification, the numerical value range described by using "~" means that the numerical value described before and after "~" is included as the lower limit value and the upper limit value.

The polybutadiene mixture of the present disclosure contains 1,2-polybutadiene and 1,4-polybutadiene. The polybutadiene rubber mixture is produced by a method including a step of polymerizing 1,3-butadiene in the presence of 1,2-polybutadiene and a lanthanoid catalyst (hereinafter referred to as "step Y"). The polybutadiene mixture of the present disclosure is preferably produced by a method that further comprises step X to obtain 1,2-polybutadiene, together with step Y. Hereinafter, each step will be described in detail.

<Step X (1, 2 polymerization steps)>
Step X is a step of producing 1,2-polybutadiene, which is a matrix component of the polybutadiene mixture, by polymerizing 1,3-butadiene in the presence of a cobalt-based catalyst. This step X includes a step of preparing a mixture of 1,3-butadiene and an organic solvent, and a step of polymerizing 1,3-butadiene (more specifically, 1,2-polymerization) in the presence of a cobalt-based catalyst. Includes a step of stopping the polymerization reaction. In the following, the 1,2-polybutadiene obtained by the polymerization reaction in step X is also referred to as "1,2-polybutadiene (A)".

(Preparation process)
The organic solvent used in this step is a solvent containing a hydrocarbon or a halogenated hydrocarbon as a main component. Specific examples of hydrocarbons include saturated aliphatic hydrocarbons having 4 to 10 carbon atoms such as butane, pentane, hexane and heptane; saturated alicyclic hydrocarbons having 6 to 20 carbon atoms such as cyclopentane and cyclohexane; 1- Monoolefins such as butene and 2-butene; aromatic hydrocarbons such as benzene, toluene and xylene can be mentioned. Specific examples of halogenated hydrocarbons include methylene chloride, chloroform, carbon tetrachloride, trichlorethylene, perchloroethylene, 1,2-dichloroethane, chlorobenzene, brombenzene, chlorotoluene and the like. Of these, hydrocarbons can be preferably used as the organic solvent.

In the mixture of 1,3-butadiene and the organic solvent, the amount of 1,3-butadiene with respect to the total amount of 1,3-butadiene and the organic solvent is preferably 3 to 80% by mass, and 15 to 30% by mass. Is more preferable. The temperature at which the mixture of 1,3-butadiene and the organic solvent is prepared is preferably 10 to 50 ° C, more preferably 30 to 40 ° C.

(1, 2 polymerization steps)
In this step, a mixture of 1,3-butadiene and an organic solvent obtained in the above preparation step is used, and in the presence of a cobalt-based catalyst, in an organic solvent containing a hydrocarbon or a halogenated hydrocarbon as a main component 1, 3-butadiene is polymerized 1,2. As a result, 1,2-syndiotactic polybutadiene can be produced as 1,2-polybutadiene (A).

The cobalt-based catalyst used contains a cobalt compound. The cobalt compound is preferably a cobalt salt, and specifically, a cobalt halide salt such as cobalt chloride, cobalt bromide, and cobalt iodide; an organic acid cobalt salt such as cobalt octylate, cobalt versaticate, and cobalt naphthenate. , And so on. Of these, it is preferable to use an organic acid cobalt salt as the cobalt compound in that it does not contain a halogen atom.

The proportion of the cobalt compound used is such that the molar ratio of 1,3-butadiene used (1,3-butadiene / Co) to the cobalt atom of the cobalt compound is l5,000 to 150,000. The amount is preferably 10,000 to 100,000, and more preferably 10,000 to 100,000. By setting the 1,3-butadiene / Co (molar ratio) to 5,000 or more, it is preferable in that the molecular weight of 1,2-polybutadiene (A) can be suppressed from becoming too low. Further, it is preferable to set 1,3-butadiene / Co (molar ratio) to 150,000 or less in that a decrease in polymerization activity can be suppressed.

The cobalt-based catalyst used in step X preferably further contains a phosphine compound and an organoaluminum compound together with the cobalt compound. The phosphine compound is a phosphine compound having one branched aliphatic hydrocarbon group having 3 or more carbon atoms or an alicyclic hydrocarbon group having 5 or more carbon atoms and two aromatic hydrocarbon groups. Is preferable. The branched aliphatic hydrocarbon group having 3 or more carbon atoms is preferably a branched alkyl group having 3 to 10 carbon atoms. The alicyclic hydrocarbon group having 5 or more carbon atoms is preferably a substituted or unsubstituted cycloalkyl group having 5 to 10 carbon atoms. The aromatic hydrocarbon group is preferably a phenyl group.

Preferred specific examples of the phosphine compound include diphenylcyclohexylphosphine, diphenylisopropylphosphine, diphenylisobutylphosphine, diphenylt-butylphosphine, diphenylcyclopentylphosphine, diphenyl (4-methylcyclohexyl) phosphine, diphenylcycloheptylphosphine, diphenylcyclooctylphosphine and the like. Can be mentioned. As the phosphine compound, one type can be used alone or two or more types can be used in combination. The blending ratio of the phosphine compound is preferably 1 to 5 mol, more preferably 1.5 to 4 mol, with respect to 1 mol of the cobalt compound.

Examples of the organoaluminum compound include aluminoxane (methylaminoxane and the like) and a compound formed by contacting trialkylaluminum with water (hereinafter referred to as “aluminum hydride compound”). As the aluminoxane, one synthesized in advance may be used, or one synthesized in a polymerization system may be used. For the aluminum hydride compound, the method of contacting trialkylaluminum with water is that water is brought into contact with the inert organic solvent solution of trialkylaluminum in any of steam, liquid and solid (ice) states. Good. Further, the contact may be carried out as a dissolved state, a dispersed state or an emulsified state in an inert organic solvent, or as a gas state or a mist state existing in the inert gas.

In the cobalt-based catalyst, the ratio of the organoaluminum compound used is such that the molar ratio of 1,3-butadiene (1,3-butadiene / Al) to the aluminum atom of the organoaluminum compound is 500 to 4,000. The amount is preferably 800 to 2,000, and more preferably 800 to 2,000. When 1,3-butadiene / Al (molar ratio) is 500 or more, the reaction easily proceeds sufficiently, while when it is 4,000 or less, the polymerization activity tends to be increased, which is preferable.

1, 2, The reaction temperature in the polymerization is usually −20 ° C. to 80 ° C., preferably 30 ° C. to 70 ° C. The reaction time is preferably 5 minutes to 6 hours, more preferably 10 to 3 hours. The polymerization reaction may be a batch type or a continuous type. The concentration of 1,3-butadiene in the reaction solution is usually 5 to 80% by mass, preferably 8 to 25% by mass. Further, in order to prevent the catalyst and the polymer from being inactivated, measures may be taken to suppress the mixing of inactivating compounds such as oxygen, water, and carbon dioxide in the polymerization system.

(Stop process)
In step X, it is preferable to stop the 1,2 polymerization reaction by adding an organoaluminum compound to the polymerization system after the syndiotactic-1,2 polymerization reaction reaches a desired reaction conversion rate.

1, As the organoaluminum compound used for terminating the polymerization reaction, for example, trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-t- Alkylaluminum compounds such as butylaluminum, tripentylaluminum, trihexylaluminum, tricyclohexylaluminum, trioctylaluminum;
Diethyl aluminum hydride, di-n-propyl aluminum hydride, di-n-butyl aluminum hydride, diisobutyl aluminum hydride, dihexyl aluminum hydride, diisohexyl hydride, dioctyl aluminum hydride, diisooctyl hydride Examples include hydrogenated aluminum compounds such as aluminum. Of these, the organoaluminum compound used for terminating the 1, 2 polymerization reaction is at least one selected from the group consisting of diisobutylaluminum hydride, triethylaluminum, triisobutylaluminum, and diethylaluminum hydride. Is preferable. As the organoaluminum compound, it can be used alone or in combination of two or more.

When stopping the 1,2 polymerization reaction, the proportion of the organoaluminum compound used is preferably 1 to 20 mol, more preferably 5 to 15 mol, per 1 mol of the cobalt compound used in the 1,2 polymerization reaction. .. By setting the proportion of the organoaluminum compound used within the above range, the molecular weight of 1,2-polybutadiene (A) does not become too high, or the molecular weight of 1,4-polybutadiene obtained in step Y does not become too low. Suitable. The temperature at which the polymerization termination reaction is carried out is usually −20 ° C. to 80 ° C., preferably 30 ° C. to 70 ° C.

According to step X, 1,2-syndiotactic polybutadiene can be produced as 1,2-polybutadiene (A). The melting point of the obtained 1,2-polybutadiene (A) is preferably 60 ° C. or higher, more preferably 100 ° C. or higher, and even more preferably 120 ° C. or higher. By setting the melting point of 1,2-polybutadiene (A) to 60 ° C. or higher, the tensile strength of the elastic body (molded article) obtained by using the polybutadiene mixture can be sufficiently increased, which is preferable.

The polystyrene-equivalent weight average molecular weight (Mw) of 1,2-polybutadiene (A) by gel permeation chromatography (GPC) is preferably 50,000 or more, more preferably 70,000 or more. It is particularly preferably 100,000 or more. The weight average molecular weight (Mw) of 1,2-polybutadiene (A) is preferably 600,000 or less, more preferably 500,000 or less, and particularly preferably 450,000 or less. .. When the weight average molecular weight of 1,2-polybutadiene (A) is less than 50,000, the abrasion resistance of the molded product obtained by using the polybutadiene mixture tends to decrease, and when it exceeds 600,000, it is processed. The sex tends to decrease.

The content of the 1,2-vinyl bond in 1,2-polybutadiene (A) is preferably 90% or more, more preferably 95% or more. When the content of the 1,2-vinyl bond is 90% or more, it is preferable that the abrasion resistance of the molded product obtained by using the polybutadiene mixture can be improved.

<Step Y (cis-1,4 polymerization step)>
In step Y, 1,4-polybutadiene is produced by polymerizing 1,3-butadiene (cis-1,4 polymerization) in the presence of 1,2-polybutadiene and a lanthanoid-based catalyst. In this step, it is preferable to use 1,2-polybutadiene (A) produced in step X as 1,2-polybutadiene. At that time, it is preferable to add a lanthanoid catalyst to the reaction mixture obtained in the above step X to polymerize 1,3-butadiene in order to simplify the production process. In the following, the 1,4-polybutadiene obtained by the polymerization reaction in step Y is also referred to as "1,4-polybutadiene (B)".

The ratio (mass ratio) of 1,2-polybutadiene and 1,3-butadiene during cis-1,4 polymerization is 1,2-polybutadiene / 1,3-butadiene = 95/5 to 50/50. If the ratio of 1,2-polybutadiene to 1,3-butadiene is too high, the content ratio of 1,4-polybutadiene in the polybutadiene mixture is small, and the effect of improving tensile strength cannot be sufficiently obtained. Further, if the ratio of 1,2-polybutadiene to 1,3-butadiene is too low, the content ratio of 1,2-polybutadiene in the polybutadiene mixture is small, and sufficient thermoplasticity cannot be obtained. The ratio of 1,2-polybutadiene to 1,3-butadiene is preferably 95/5 to 60/40, more preferably 90/10 to 60/40, and even more preferably 90/10 to 65/40. 35.

The lanthanoid catalyst used in step Y contains a lanthanoid compound. A lanthanoid compound is a compound having at least one element belonging to a lanthanoid. The lanthanoid compound may be a reaction product of a compound having a lanthanoid and a Lewis base. The lanthanoid contained in the lanthanoid compound is preferably at least one selected from the group consisting of neodymium, praseodymium, cerium, lanthanum, gadolinium and samarium, and neodymium is particularly preferable. Specific examples of the lanthanoid compound include lanthanoid carboxylates, alcoholides, β-diketone complexes, phosphates and phosphates.

Specific examples of the lanthanoid carboxylate include the compound represented by the formula (1); "(R ^1- CO ₂ ) ₃ M" (where M is a lanthanoid and R ¹ has 1 to 20 carbon atoms. It is a monovalent hydrocarbon group.). In the above formula (1), R ¹ is preferably a saturated or unsaturated monovalent chain hydrocarbon group, and preferably a linear, branched or cyclic alkyl group. The carbonyl group in the above formula (1) is bonded to the primary, secondary or tertiary carbon atom of R ¹ . As M, neodymium, praseodymium, cerium, lanthanum, gadolinium or samarium are preferable, and neodymium is more preferable.
Specific examples of the compound represented by the above formula (1) include octanoic acid, 2-ethylhexanoic acid, oleic acid, stearic acid, benzoic acid, naphthenic acid, and trade name "versatic acid" (manufactured by Shell Chemical Co., Ltd., carboxyl). Examples thereof include salts such as carboxylic acid) whose group is bonded to a tertiary carbon atom. Of these, the compound represented by the above formula (1) is preferably a salt of versatic acid, 2-ethylhexanoic acid or naphthenic acid.

Specific examples of the alkoxide of lanthanoid has the formula ^{(2); (R 2 O} ) compound represented by the ₃ M (however, M is a lanthanoid, ^{R 2} is a monovalent hydrocarbon group having 1 to 20 carbon atoms Is mentioned.). In the above formula (2), examples of R ² include a monovalent chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. R ² is preferably a monovalent aromatic hydrocarbon group. Specific examples of the group "R ² O-" in the above formula (2) include 2-ethyl-hexylalkoxy group, oleylalkoxy group, stearylalkoxy group, phenoxy group, benzylalkoxy group and the like. Of these, the group "R ² O-" is preferably a 2-ethyl-hexyl alkoxy group or a benzyl alkoxy group. The explanation of the above formula (1) is applied to the explanation of M and the preferable example.

Specific examples of the β-diketone complex of the lanthanoid include an acetylacetone complex, a benzoylacetone complex, a propionitrile acetone complex, a valeryl acetone complex, an ethyl acetylacetone complex and the like. Of these, an acetylacetone complex or an ethylacetylacetone complex is preferable.

Specific examples of lanthanoid phosphate or phosphite include bis phosphate (2-ethylhexyl) bis phosphate (1-methylheptyl), bis phosphate (p-nonylphenyl), and bis phosphate (polyethylene glycol). -P-nonylphenyl), phosphoric acid (1-methylheptyl) (2-ethylhexyl), phosphoric acid (2-ethylhexyl) (p-nonylphenyl), 2-ethylhexylphosphonate mono-2-ethylhexyl, 2-ethylhexylphosphon Acids Mono-p-nonylphenyl, bis (2-ethylhexyl) phosphinic acid, bis (1-methylheptyl) phosphinic acid, bis (p-nonylphenyl) phosphinic acid, (1-methylheptyl) (2-ethylhexyl) phosphinic acid , (2-Ethylhexyl) (p-nonylphenyl) phosphinic acid and the like. Of these, the phosphate or phosphite includes bis phosphate (2-ethylhexyl), bis phosphate (1-methylheptyl), mono-2-ethylhexyl 2-ethylhexylphosphonate or bis (2-ethylhexyl). ) Phosphonic acid salts are preferred.

Of these, the lanthanoid compound used in step Y is preferably a carboxylate or a phosphate, and more preferably a carboxylate. Among these, neodymium phosphate or neodymium carboxylic acid salt is more preferable, and neodymium versaticate or neodymium 2-ethylhexanoate is particularly preferable.

In order to solubilize the lanthanoid compound in a solvent or to store it stably for a long period of time, the lanthanoid compound and a Lewis base may be mixed, or the lanthanoid compound and a Lewis base may be reacted to obtain a reaction product. preferable. The amount of the Lewis base used is preferably 0 to 30 mol, more preferably 1 to 10 mol, with respect to 1 mol of the lanthanoid contained in the lanthanoid compound. Specific examples of Lewis bases include acetylacetone, tetrahydrofuran, pyridine, N, N-dimethylformamide, thiophene, diphenyl ether, triethylamine, organophosphorus compounds, monohydric or divalent alcohols and the like. In step Y, one type of lanthanoid compound may be used alone or two or more types may be used in combination.

The ratio of the lanthanoid compound used in the step Y is preferably 0.00001 to 1.0 mmol, preferably 0.0001 to 0.5 mmol, based on 100 g of 1,3-butadiene used in the step Y. Is more preferable. It is preferable that the ratio of the lanthanoid compound used is 0.00001 mmol or more because the polymerization activity can be sufficiently increased. Further, it is preferable that the usage ratio is 1.0 mmol or less because it is possible to prevent the catalyst concentration from becoming too high and it is not necessary to provide a decalcification step.

The lanthanoid catalyst used in step Y preferably further contains an organoaluminum compound and a halogen compound together with the lanthanoid compound.

As the organoaluminum compound, it is preferable to use at least one selected from the group consisting of aluminoxane, an alkylaluminum compound and an aluminum hydride compound. Of these, it is particularly preferable to use at least one compound selected from the group consisting of an alkylaluminum compound and an aluminum hydride compound (hereinafter referred to as "aluminum compound (L)") in combination with aluminoxane.

（式（３）及び式（４）中、Ｒ^３及びＲ^４は、それぞれ独立に炭素数１〜２０の１価の炭化水素基であり、ｋ及びｍは、それぞれ独立に２以上の整数である。式（３）中の複数のＲ^３は互いに同じでも異なっていてもよい。ｍが２以上の場合、式（４）中の複数のＲ^４は互いに同じでも異なっていてもよい。） Preferred specific examples of the aluminoxane used in this step include a compound represented by the following formula (3) and a compound represented by the following formula (4). It should be noted in Fine Chemicals, 23, (9) 5 (1994), J.Am.Chem.Soc., 115,4971 (1993), and J.Am.Che.Soc., 117,6465 (1995). You may use an aggregate of aluminoxane.

(In formulas (3) and (4), R ³ and R ⁴ are independently monovalent hydrocarbon groups having 1 to 20 carbon atoms, and k and m are independently integers of 2 or more. there. equation (3) a plurality of R ³ when good .m be the same or different are 2 or more mutually in a plurality of R ⁴ in the formula (4) may be the same or different from each other.)

Examples of R ³ in the above formula (3) and R ⁴ in the above formula (4) include methyl group, ethyl group, propyl group, butyl group, isobutyl group, t-butyl group, hexyl group, isohexyl group and octyl. Groups, isooctyl groups and the like can be mentioned. Of these, a methyl group, an ethyl group, an isobutyl group or a t-butyl group is preferable, and a methyl group is particularly preferable. k and m are preferably integers of 4 to 100.

Specific examples of the aluminoxane include methylaluminoxane (hereinafter, also referred to as “MAO”), ethylaluminoxane, n-propylaluminoxane, n-butylaluminoxane, isobutylaluminoxane, t-butylaluminoxane, hexylaluminoxane, isohexylaluminoxane and the like. Can be done. Among these, MAO is preferable. As the aluminoxane, one type can be used alone or two or more types can be used in combination.

The ratio of aluminoxane used in the lanthanoid catalyst is preferably such that the amount of aluminum (Al) contained in aluminoxane is 1 to 500 mol with respect to 1 mol of the lanthanoid compound used in the 1,4 polymerization reaction. The amount is more preferably 3 to 250 mol, and even more preferably 5 to 200 mol. By setting the usage ratio of aluminum oxane within the above range, it is preferable in that a decrease in catalytic activity is suppressed and a step of removing the catalyst residue does not need to be provided.

Specific examples of the aluminum compound (L) include the alkylaluminum compound and the aluminum hydride compound exemplified in the description of the stopping step. As the aluminum compound (L), one type may be used alone, or two or more types may be used in combination. Of these, the aluminum compound (L) is preferably at least one selected from the group consisting of diisobutylaluminum hydride, triethylaluminum, triisobutylaluminum, and diethylaluminum hydride. In the preparation of the lanthanoid catalyst, the ratio of the aluminum compound (L) used is 1 to 700 mol, which is the total amount of the aluminum compound (L) used with respect to 1 mol of the lanthanoid compound used in the 1,4 polymerization reaction. It is preferable that the amount is 3 to 500 mol.

The halogen compound used as one component of the lanthanoid-based catalyst is preferably a chlorine-containing compound, and more preferably at least one selected from the group consisting of silicon chloride compounds and hydrocarbon compounds. Examples of the silicon chloride compound used include trimethylsilyl chloride, triethylsilyl chloride, dimethylsilyl dichloride and the like. Of these, trimethylsilyl chloride can be preferably used as the silicon chloride compound. Specific examples of the chlorinated hydrocarbon compound include methyl chloride, butyl chloride, hexyl chloride, octyl chloride, chloroform, dichloromethane, benzylene chloride and the like. Of these, it is preferable to use methyl chloride, chloroform or dichloromethane.

In the preparation of the lanthanoid-based catalyst, the ratio of the halogen compound used is preferably 0.5 to 3 in terms of the molar ratio of the halogen atom (halogen atom / lanthanoid compound) of the halogen compound to 1 mol of the lanthanoid compound. It is more preferably 1.0 to 2.5, and even more preferably 1.2 to 1.8. It is preferable that the molar ratio of the halogen atom / lanthanoid compound is 0.5 or more because the polymerization catalytic activity can be sufficiently increased. Further, when the molar ratio is 3 or less, it is preferable that the halogen compound can be prevented from becoming a catalytic poison.

The reaction temperature at the time of 1,4 polymerization in the step Y is preferably −30 ° C. to 200 ° C., more preferably 0 ° C. to 150 ° C. The type of the polymerization reaction is not particularly limited, and it may be carried out by using a batch reactor or by using a multi-stage continuous reactor or the like. When the 1,4 polymerization reaction is carried out using a polymerization solvent, the monomer concentration in the solvent is preferably 5 to 50% by mass, more preferably 7 to 35% by mass. From the viewpoint of producing 1,4-polybutadiene and preventing the inactivation of 1,4-polybutadiene having an active terminal, the polymerization system has an inactivating action such as oxygen, water or carbon dioxide. It is preferable to take measures to prevent the compound from being mixed.

The content ratio of 1,4-polybutadiene (B) is preferably 1% by mass or more, more preferably 5% by mass or more, and 8% by mass, based on the total amount of the polybutadiene mixture obtained by this production method. It is more preferably% or more. The content ratio of 1,4-polybutadiene (B) is preferably 30% by mass or less, and more preferably 25% by mass or less, based on the total amount of the polybutadiene mixture obtained by this production method. When the content ratio of 1,4-polybutadiene (B) is 1% by mass or more, it is preferable in that the tensile strength, elongation and tensile product of the molded product obtained by using the polybutadiene mixture can be sufficiently increased. .. Further, when the content ratio of 1,4-polybutadiene (B) is 30% by mass or less, it is preferable in that the abrasion resistance of the molded product obtained by using the polybutadiene mixture can be sufficiently increased.

By the above 1,4 polymerization reaction, 1,4-polybutadiene having an active terminal can be obtained. The polystyrene-equivalent weight average molecular weight (Mw) of the obtained 1,4-polybutadiene (B) by GPC is preferably 50,000 or more, more preferably 100,000 or more, and 150,000 or more. It is particularly preferable to have. The weight average molecular weight (Mw) of 1,4-polybutadiene (B) is preferably 2,000,000 or less, more preferably 1,500,000 or less, and 1,000,000 or less. Is particularly preferable. When the weight average molecular weight of 1,4-polybutadiene (B) is less than 50,000, the wear resistance tends to decrease, and when it exceeds 2,000,000, the workability tends to decrease. ..

For 1,4-polybutadiene (B), the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is preferably 2.0 to 4.0, preferably 2.1 to 3.5. More preferred. When the Mw / Mn of the 1,4-polybutadiene rubber is 4.0 or less, it is preferable in that the toughness (tensile product) of the obtained molded product can be improved.

The content of the cis-1,4 structure in 1,4-polybutadiene (B) is preferably 89% or more, and more preferably 93% or more. When the content of the cis-1,4 structure is 89% or more, the abrasion resistance of the molded product obtained by using the polybutadiene mixture can be improved, which is preferable. According to the step Y, as a polybutadiene mixture, a mixture of 1,2-syndiotactic polybutadiene which is a matrix component and 1,4-polybutadiene (B) is obtained.
The content ratio of 1,2-polybutadiene (A) is preferably 70% by mass or more, more preferably 75% by mass or more, based on the total amount of the polybutadiene mixture obtained by this production method. The content of 1,2-polybutadiene (A) is preferably 99% by mass or less, more preferably 95% by mass or less, still more preferably 92% by mass or less, based on the total amount of the polybutadiene mixture. is there.

<Other processes>
The present manufacturing method may further include steps other than the above steps X and Y.
・ Process Z (denaturation process)
In step Y above, after the cis-1,4 polymerization reaction reaches the desired reaction conversion rate, an anti-aging agent (eg, 2,4-di-tert-butyl-p-cresol, 4,6) is immediately followed according to a conventional method. -Bis (octylthiomethyl) -o-cresol, etc.) may be added to the polymerization system, or the polymerization terminal of 1,4-polybutadiene (B) may be modified with an alkoxysilane compound. By such a modification reaction, the active terminal of 1,4-polybutadiene (B) reacts with the alkoxysilane compound, and 1,4-polybutadiene having a silicon-containing group introduced at the polymerization terminal can be obtained. When the 1,4-polybutadiene contained in the polybutadiene mixture is terminal-modified, the polybutadiene mixture is a material for obtaining vulcanized rubber which is excellent in tensile strength, elongation and tensile strength, and also excellent in fuel efficiency. Is suitable as.

The alkoxysilane compound used in the modification step (hereinafter, also referred to as “alkoxysilane compound (S)”) has at least one alkoxysilyl group and can react with the active terminal of 1,4-polybutadiene. It is preferably a compound. Of these, the alkoxysilane compound (S) is an alkoxysilane compound having at least one functional group selected from the group consisting of an epoxy group, an isocyanate group, a carbonyl group and a cyano group in that it has high reactivity with an active terminal. Is preferable. The alkoxysilane compound (S) may be a partial condensate or a mixture of the alkoxysilane compound and the partial condensate.

The denaturation reaction is preferably carried out in solution. As the solution, the solution containing the unreacted monomer obtained in the above step Y can be used as it is. In this case, it is preferable in that the manufacturing process can be simplified. Further, in the modification reaction, the ratio of the alkoxysilane compound (S) used is preferably 0.01 to 200 mol, preferably 0.1 to 150 mol, based on 1 mol of the lanthanoid compound used in the above step Y. Is more preferable. The temperature of the denaturation reaction is preferably the same as the polymerization temperature of 1,4-polybutadiene. The reaction time in the denaturation reaction is preferably 5 minutes to 5 hours, more preferably 15 minutes to 1 hour. In the production method of the present disclosure, if the modification reaction is not carried out, after the completion of 1,4 polymerization by step Y, and if the modification reaction is carried out, after the modification reaction, if desired, a known antioxidant or reaction terminator. Can be added in the denaturation step.

When the terminal modification of 1,4-polybutadiene (B) is carried out in step Z, the residue of the alkoxysilane compound (S) introduced into the active terminal is condensed and consumed in the desolubilization step after the modification reaction. The compound to be used (hereinafter, also referred to as “condensation catalyst”) may be further added. As a specific example of the condensation catalyst, a condensation catalyst containing at least one element among the elements contained in the groups 4A, 2B, 3B, 4B and 5B of the periodic table is preferable. By adding the condensation catalyst, the condensation reaction of the residue of the alkoxysilane compound (S) can be promoted more effectively, and 1,4-polybutadiene having excellent processability, low temperature characteristics and abrasion resistance can be obtained. It becomes possible.

The polybutadiene mixture of the present disclosure can be obtained by removing the solvent from the solution obtained above and isolating the polymer. The polymer can be isolated by a known desolvation method such as steam stripping and a drying operation such as heat treatment.

The polybutadiene mixture obtained by this production method has 1,4-polybutadiene, 1,4-polybutadiene and 1,2-syndiotactic polybutadiene, as opposed to 1,2-syndiotactic polybutadiene having a melting point of 60 to 150 ° C. It is preferable that the content is 5 to 30% by mass with respect to the total amount of. The polybutadiene mixture of the present disclosure can be used alone or, if necessary, blended with other synthetic resins, synthetic rubbers or natural rubbers to form a raw material resin or rubber, and if necessary with a process oil. It is oil-expanded, and then a commonly used vulcanized rubber compounding agent such as various fillers such as carbon black, a vulcanizing agent, and a vulcanization accelerator is added and vulcanized as a rubber composition to be tensioned. Applications that require strength, elongation and tensile strength, such as tires, hoses, belts, sponges, footwear materials, sheets, films, tubes, packaging materials, resin modifiers, photosensitive materials, etc. It can be used for various industrial products.

The vinyl content (content of 1,2-vinyl bond) of the polybutadiene mixture obtained by this production method is preferably 90% or more, more preferably 93% or more. When the vinyl content is 90% or more, it is preferable in that the abrasion resistance of the molded product obtained by using the polybutadiene mixture can be sufficiently ensured. In this specification, the "vinyl content" is a value measured by ^{1 1} H-NMR.

The polystyrene-equivalent weight average molecular weight (Mw) of the polybutadiene mixture by GPC is preferably 50,000 or more, more preferably 70,000 or more, and further preferably 100,000 or more. The weight average molecular weight (Mw) of the polybutadiene mixture is preferably 700,000 or less, more preferably 600,000 or less, and particularly preferably 500,000 or less. The ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) in the obtained polybutadiene mixture is preferably 2.0 to 4.0, more preferably 2.1 to 3.5. When the Mw / Mn of the polybutadiene mixture is 4.0 or less, it is preferable in that the fracture characteristics of the molded product can be improved.

Hereinafter, the present invention will be specifically described based on Examples, but the present invention is not limited to these Examples. In addition, "part" and "%" in Examples and Comparative Examples are based on mass unless otherwise specified. The method for measuring various physical property values of the polymer is shown below.

[Melting point]: Measured using a differential scanning calorimeter (trade name: X-DSC7000, manufactured by SII Technology Co., Ltd.).
[Weight average molecular weight and molecular weight distribution]: Using a gel permeation chromatograph (trade name: VISCOTEC GPCmax, manufactured by Malvern), measure under the following conditions using a differential refractometer as a detector, and use it as a standard polystyrene conversion value. Calculated.
Column: 2 product names "GMHHR-H" (manufactured by Tosoh Corporation), column temperature: 38 ° C
Mobile phase; tetrahydrofuran, flow rate; 1.0 ml / min Sample concentration; 10 mg / 20 ml

[Cys-1,4 bond content and vinyl content]: Using an infrared spectrophotometer (trade name: FT / IR-4100 series, manufactured by Jasco) and using a ZnSe prism, a wave number of 1000 to 600 cm ^-1 is measured. It was measured.
[1,2-Polybutadiene content and 1,4-polybutadiene content]: The content of 1,2-syndiotactic polybutadiene in the polybutadiene mixture α [%] according to the following formulas (1) to (5). And the content β [%] of 1,4-polybutadiene was calculated. The abbreviations in the calculation formulas (1) to (5) have the following meanings.
Q1: 1,3-butadiene (for syndiotactic-1,2 polymerization) input amount Q2: 1,2-polybutadiene production amount Q3: 1,3-butadiene unreacted amount in 1,3-butadiene Q4: 1,3- Butadiene (for cis-1,4 polymerization) input amount Q5: 1,4-polybutadiene production amount Q2 = Q1 × (reaction conversion rate of syndiotactic-1 and 2 polymerization) ... (1)
Q3 = Q1-Q2 ... (2)
Q5 = (Q3 + Q4) × (reaction conversion rate of cis-1,4 polymerization) ... (3)
Content rate α = (Q2 ÷ (Q2 + Q5)) × 100… (4)
Content rate β = 100-α ... (5)

1. 1. Production of Polybutadiene Mixture [Example 1]
1.5 kg of cyclohexane and 300 g of 1,3-butadiene were placed in a nitrogen-substituted 3 L autoclave. Separately, a dichloride solution containing 0.12 mmol of cobalt chloride, a dichloride solution containing 0.24 mmol of diphenylcyclohexylphosphine, and a toluene solution containing 3.60 mmol of methylaluminoxane (MAO) were mixed. The catalyst composition A was prepared by reacting at 30 ° C. for 60 minutes. This catalyst composition A was put into the above autoclave and reacted at 55 ° C. for 1 hour (syndiotactic-1 and 2 polymerization) to obtain a polymer solution. The reaction conversion rate of the added 1,3-butadiene was about 80%. Then, in order to stop the polymerization reaction, a toluene solution containing 1.2 mmol of diisobutylaluminum hydride was put into the autoclave and stirred for 15 minutes.

In order to measure various physical properties of the polybutadiene resin obtained by the above reaction, 18 g of the polymer solution was extracted from the above polymer solution, and 2,6-di-t-butyl-p-cresol was added to the extracted polymer solution. A toluene solution containing the mixture was added to stop the polymerization reaction. Then, the solvent was removed by heating on a hot plate. When various physical property values of the obtained polybutadiene resin (1,2-syndiotactic polybutadiene) were measured, the melting point was 121 ° C., and the weight average molecular weight (Mw) of 1,2-polybutadiene was 290,000.

Subsequently, a cyclohexane solution containing 8.7 micromoles of neodymium versaticate (Nd (ver) ₃ ), a toluene solution containing 0.28 mmol MAO, and toluene containing 0.67 mmol diisobutylaluminum hydride. A solution and a toluene solution containing 10.6 micromoles of trimethylsilyl chloride (Me ₃ SiCl) and 1,3-butadiene 1.1 mmol (1,2-polybutadiene / 1,3-butadiene = 80/20) The catalyst composition B was prepared by reacting the mixture at 30 ° C. for 60 minutes. This catalyst composition B was put into the above autoclave and reacted at 70 ° C. for 1 hour (cis-1,4 polymerization) to obtain a polymer solution containing a polybutadiene mixture. The reaction conversion rate of unreacted 1,3-butadiene in 1,4 polymerization was about 25%.

Next, in order to measure various physical property values of the polybutadiene mixture obtained by the above reaction, 200 g of the polymer solution was extracted from the above polymer solution, and 2,6-di-tert-butyl-p- was added to the extracted polymer solution. A toluene solution containing 1.5 g of cresol was added to terminate the polymerization reaction. Then, the solvent was removed by heating on a hot plate to obtain a polybutadiene mixture P1. When various physical property values of the polybutadiene mixture P1 were measured, the 1,2-polybutadiene content was 93.6%, the 1,4-polybutadiene content was 6.4%, and the molecular weight distribution (Mw / Mn) was 2.82. The content of cis-1,4 bond was 5.0%, the content of 1,2-vinyl bond was 95.0%, and the weight average molecular weight (Mw) was 300,000. The melting point of 1,2-polybutadiene contained in the polybutadiene mixture P1 was 121 ° C., and the weight average molecular weight (Mw) was 290,000.

[Example 2]
In Example 1, the same operations as in Example 1 were performed except that the polymerization formulations for the 1st and 2nd polymerizations were as shown in Table 1 below and the polymerization formulations for the cis-1 and 4 polymerizations were as shown in Table 2 below. , Polybutadiene mixture P2 was obtained. The measurement results of the physical property values of the obtained polybutadiene mixture P2 are shown in Table 3 below. In Table 3, Reference Example 1 shows the measurement results of a commercially available syndiotactic 1,2-polybutadiene resin (trade name "RB840", manufactured by JSR Corporation).

The abbreviations in Tables 1 and 2 have the following meanings.
CoCL2: cobalt chloride (CoCl ₂₎
PCH: diphenylcyclohexylphosphine AlBuH: diisobutylaluminum hydride (AlBu ₂ H)
NdVer: Neodymium Versatic Acid (Nd (ver) ₃ )
MeSiCl: Trimethylsilyl chloride (Me ₃ SiCl)

2. 2. Evaluation of Polybutadiene Mixture [Examples 3 and 4]
For each of the polybutadiene mixtures P1 and P2 obtained in Example 1 and Example 2, the tensile strength at cutting (TB), the elongation at cutting (EB), and the tensile product were evaluated. The evaluation was performed by the following procedure.
First, the polybutadiene mixture was formed into a sheet and punched out with a JIS-3 dumbbell cutter in accordance with JIS K6251: 2010 to obtain a test piece for evaluation (dumbbell-shaped test piece). Using a tensile tester (model name "AG-2000", manufactured by Shimadzu Corporation), the sample piece is pulled at a load speed of 500 mm / min, and the tensile strength at cutting (TB) and elongation at cutting (EB). ) Was measured. Further, the tensile product was obtained from the product of the measurement results of the tensile strength at the time of cutting (TB) and the elongation at the time of cutting (EB). The results are shown in Table 4 below. The results were expressed as an index with Comparative Example 1 as 100.

[Comparative Example 1]
Tension strength at cutting (same as in Examples 1 and 2) except that a commercially available syndiotactic 1,2-polybutadiene resin (trade name "RB840", manufactured by JSR Corporation) was used instead of the polybutadiene mixture. TB) and elongation at cutting (EB) were measured, and the tensile volume was determined. The results are shown in Table 4 below.
[Comparative Example 2]
To 95 parts of the syndiotactic 1,2-polybutadiene resin used in Comparative Example 1, 5 parts of a commercially available high cis polybutadiene rubber (trade name "BR740", manufactured by JSR Corporation) was mixed, and a plast mill was used. By kneading, a polybutadiene mixture Q1 was obtained. Further, using the obtained polybutadiene mixture Q1, the tensile strength at cutting (TB) and the elongation at cutting (EB) were measured in the same manner as in Examples 1 and 2, and the tensile product was determined. The results are shown in Table 4 below.
[Comparative Example 3]
Kneading was carried out in the same manner as in Comparative Example 2 except that the formulation was changed to the formulation shown in Table 4 below to obtain a polybutadiene mixture Q2. Further, using the obtained polybutadiene mixture Q2, the tensile strength at cutting (TB) and the elongation at cutting (EB) were measured in the same manner as in Examples 1 and 2, and the tensile product was determined. The results are shown in Table 4 below.

In Table 4, "blending ratio" and "content ratio" indicate the ratio of each polymer to the total amount of polybutadiene used for preparing the sample piece. The "1,2-PBD / 1,3-BD ratio at the time of 1,4 polymerization" is the mass ratio of 1,2-polybutadiene and 1,3-butadiene at the time of cis 1,4-polymerization (1,2). -Polybutadiene / 1,3-butadiene). The abbreviations in Table 4 have the following meanings.
RB840: 1,2-polybutadiene (trade name "RB840", manufactured by JSR Corporation)
BR740: High cis polybutadiene rubber (trade name "BR740", manufactured by JSR Corporation)
1,2-PBD: 1,2-polybutadiene 1,4-PBD: 1,4-polybutadiene 1,3-BD: 1,3-butadiene

As shown in Table 4, the polybutadiene mixtures P1 and P2 of Examples 1 and 2 are superior to the polybutadiene of Comparative Example 1 and the polybutadiene mixture of Comparative Examples 2 and 3 in tensile strength, elongation and tensile strength. Evaluation results were obtained. In particular, the tensile product of the polybutadiene mixture P1 of Example 1 was about 1.7 times that of Comparative Example 1, 1.9 times that of Comparative Example 2, and about 2.2 times that of Comparative Example 3. Further, the polybutadiene mixture P2 of Example 2 was about 1.9 times that of Comparative Example 1, about 2.1 times that of Comparative Example 2, and about 2.4 times that of Comparative Example 3, which were greatly improved.

From the above, it was clarified that according to the method for producing a polybutadiene mixture of the present invention, a polybutadiene mixture having excellent tensile strength, elongation and tensile strength can be obtained.

Claims (11)

Including step Y of polymerizing 1,3-butadiene in the presence of 1,2-polybutadiene and a lanthanoid catalyst.
Production of a polybutadiene mixture in which the mass ratio of 1,2-polybutadiene to 1,3-butadiene during the polymerization of step Y is 1,2-polybutadiene / 1,3-butadiene = 95/5 to 50/50. Method. Further comprising step X to obtain 1,2-polybutadiene by polymerizing 1,3-butadiene in the presence of a cobalt-based catalyst.
The method for producing a polybutadiene mixture according to claim 1, wherein the step Y is a step of polymerizing 1,3-butadiene in the presence of the 1,2-polybutadiene obtained in the step X and the lanthanoid catalyst. .. The method for producing a polybutadiene mixture according to claim 2, wherein in the step X, the polymerization of 1,2-polybutadiene is stopped by adding an organoaluminum compound. The method for producing a polybutadiene mixture according to claim 2 or 3, wherein the step Y is a step of adding the lanthanoid catalyst to the reaction mixture obtained in the step X to polymerize 1,3-butadiene. The method for producing a polybutadiene mixture according to any one of claims 2 to 4, wherein the cobalt-based catalyst contains a cobalt compound, a phosphine compound, and an organoaluminum compound. The method for producing a polybutadiene mixture according to any one of claims 1 to 5, wherein the 1,2-polybutadiene used in the step Y is 1,2-syndiotactic polybutadiene. The method for producing a polybutadiene mixture according to any one of claims 1 to 6, wherein the lanthanoid catalyst contains a lanthanoid compound, an organoaluminum compound, and a halogen compound. The method for producing a polybutadiene mixture according to any one of claims 1 to 7, wherein the polybutadiene mixture contains 5 to 30% by mass of 1,4-polybutadiene. A polybutadiene mixture containing 1,2-polybutadiene and 1,4-polybutadiene.
It is obtained by polymerizing 1,3-butadiene in the presence of 1,2-polybutadiene and a lanthanoid-based catalyst, and the mass ratio of 1,2-polybutadiene and 1,3-butadiene in the polymerization is 1,2. -Polybutadiene mixture / 1,3-butadiene = 95/5 to 50/50. The polybutadiene mixture according to claim 9, which contains 5 to 30% by mass of 1,4-polybutadiene. A molded product formed by using the polybutadiene mixture obtained by the production method according to any one of claims 1 to 8 or the polybutadiene mixture according to claim 9 or 10.