JP2014108977A - Method of manufacturing branched butadiene polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a continuous manufacturing method of a branched butadiene polymer having reduced generation of a gel.SOLUTION: A method of manufacturing a branched butadiene polymer includes a polymerization process of continuously supplying 1,3-butadiene or 1,3-butadiene and an aromatic vinyl compound, and an inert solvent into a polymerization reactor at a supply temperature of 30°C or lower, continuously polymerizing them with an organic lithium compound as an initiator to obtain an active terminal-containing linear butadiene polymer, and a coupling process of continuously supplying the active terminal-containing linear butadiene polymer into a coupling reactor and continuously adding a coupling agent represented by the formula (1) to conduct a coupling reaction. (1), where R represents each independently an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms and n is an integer of 0 or 1.

Description

  The present invention relates to a method for continuously producing a branched butadiene polymer and a branched butadiene polymer.

As a method for producing a branched butadiene-based polymer having a branched shape and comprising a homopolymer of 1,3-butadiene or a copolymer of 1,3-butadiene and an aromatic vinyl compound, an anionic polymerization initiator is generally used. A linear (co) polymer having an active end obtained by (co) polymerizing a 1,3-butadiene monomer alone or with an aromatic vinyl compound such as styrene in the presence of A method of reacting with a polyfunctional coupling agent having the following is known.
Since the branched butadiene-based polymer can suppress the spread of molecular chains in a dilute solution when the weight average molecular weight is the same as that of the linear butadiene-based polymer, a relatively low solution viscosity (for example, 5 wt% styrene solution viscosity, etc.) and is suitably used for styrenic resin modification applications such as high impact polystyrene (HIPS).
As a method for continuously producing such a branched butadiene-based polymer, for example, as in Patent Documents 1 and 2, there is a method for producing a polyhalogenated compound such as tetrachlorosilane as a coupling agent. Generally known. However, the coupling agent contains a halogen atom as a reaction site, and a halogen compound such as LiCl is produced as a by-product after the coupling reaction and remains in the polymer, which is not preferable. Reduction of the halogen compound is desired. ing.
On the other hand, as a method using a non-halogen coupling agent, for example, Patent Document 3 proposes a method using an epoxy coupling agent, and Patent Document 4 proposes a method using a tetraalkoxysilane compound as a coupling agent. Has been.

JP2012-36400 JP2012-512288A Japanese Patent No. 2538629 Japanese Patent No. 3841485

However, the above prior art has room for improvement when the branched butadiene polymer is continuously produced.
That is, in the process of continuously producing a branched butadiene-based polymer, the present inventors include a reaction for continuously conducting a polymerization reaction while keeping the inside of the polymerization reactor at a high temperature. It has been found that there is a problem that a gel insoluble in a solvent tends to be formed in the vessel.
When the gel is mixed in the polymer, for example, in the manufacturing process of HIPS, it becomes an insoluble substance when used as a styrene solution, which may cause problems such as loss due to clogging of the filter. There has been no proposal for a continuous production method of a branched butadiene-based polymer which is sufficient and has reduced generation of gel.
Further, the branched butadiene-based polymer obtained by the above prior art has room for improvement from the viewpoint of other characteristics in addition to the mixing of the gel.
That is, in the epoxy coupling agent of Patent Document 3, Li remains in the polymer after the coupling reaction, the resulting rubber is yellowish, and there is still room for improvement with respect to the color and appearance of the rubber. The method of patent document 4 is a batch format, and the molecular weight distribution of the polymer obtained is narrow (that is, Mw / Mn is small).
This invention is made | formed in view of the said situation, and it aims at providing the continuous manufacturing method of the branched butadiene type polymer by which generation | occurrence | production of the gel was reduced. It is another object of the present invention to provide a continuous production method of a branched butadiene-based polymer having a broad molecular weight distribution, which does not contain a halogen compound, has reduced gel generation, and has excellent appearance.

（式（１）中、Ｒは、各々独立して、炭素数１〜１０のアルキル基又は炭素数６〜１０のアリール基を表す。ｎは０又は１の整数である。）
［２］前記分岐状ブタジエン系重合体が、測定温度１００℃におけるムーニー粘度（ＭＬ_１＋４）が２５≦ＭＬ_１＋４≦５５であり、２５℃で測定した５重量％スチレン溶液粘度（ＳＶ）が２５≦ＳＶ≦５０（ｍＰａ・ｓ）であり、かつＧＰＣで測定される分子量分布（Ｍｗ／Ｍｎ）が１．５〜２．５である分岐状ブタジエン系重合体である、前記［１］に記載の分岐状ブタジエン系重合体の製造方法。
［３］前記重合反応器に、アレン類化合物を、１，３−ブタジエンに対して５０〜３５０ｐｐｍの割合で連続的に供給する、前記［１］又は［２］に記載の分岐状ブタジエン系重合体の製造方法。
［４］前記カップリング工程におけるカップリング剤がテトラメトキシシラン又はテトラエトキシシランである、前記［１］〜［３］のいずれか１項に記載の分岐状ブタジエン系重合体の製造方法。
［５］前記重合反応器のうちの少なくとも１基及び前記カップリング反応器のうちの少なくとも１基が完全混合型反応器である、前記［１］〜［４］のいずれか１項に記載の分岐状ブタジエン系重合体の製造方法。
［６］前記重合反応器の塔頂部温度が１２０℃以下である、前記［１］〜［５］のいずれか１項に記載の分岐状ブタジエン系重合体の製造方法。
［７］前記分岐状ブタジエン系重合体が分岐状ポリブタジエンである、前記［１］〜［６］のいずれか１項に記載の分岐状ブタジエン系重合体の製造方法。
［８］前記分岐状ブタジエン系重合体が分岐状ブタジエン−スチレン共重合体である、前記［１］〜［６］のいずれか１項に記載の分岐状ブタジエン系重合体の製造方法。
［９］１，３−ブタジエン又は１，３−ブタジエンと芳香族ビニル化合物を不活性溶媒の存在下で重合して得られる活性末端含有線形ブタジエン系重合体を下記式（１）で表されるカップリング剤を用いてカップリング反応させて得られる分岐状ブタジエン系重合体であって、

（式（１）中、Ｒは、各々独立して、炭素数１〜１０のアルキル基又は炭素数６〜１０のアリール基を表す。ｎは０又は１の整数である。）
前記重合時の重合反応器への、１，３−ブタジエン又は１，３−ブタジエンと芳香族ビニル化合物、不活性溶媒の供給温度が３０℃以下であり、測定温度１００℃におけるムーニー粘度（ＭＬ_１＋４）が２５≦ＭＬ_１＋４≦５５であり、２５℃で測定した５重量％スチレン溶液粘度（ＳＶ）が２５≦ＳＶ≦５０（ｍＰａ・ｓ）であり、かつＧＰＣで測定される分子量分布（Ｍｗ／Ｍｎ）が１．５〜２．５である分岐状ブタジエン系重合体。
［１０］１，３−ブタジエン又は１，３−ブタジエンと芳香族ビニル化合物を不活性溶媒の存在下で重合して得られる活性末端含有線形ブタジエン系重合体を下記式（１）で表されるカップリング剤を用いてカップリング反応させて得られる分岐状ブタジエン系重合体であって、

（式（１）中、Ｒは、各々独立して、炭素数１〜１０のアルキル基又は炭素数１〜１０のアリール基を表す。ｎは０又は１の整数である。）
測定温度１００℃におけるムーニー粘度（ＭＬ_１＋４）が２５≦ＭＬ_１＋４≦５５であり、２５℃で測定した５重量％スチレン溶液粘度（ＳＶ）が２５≦ＳＶ≦５０（ｍＰａ・ｓ）であり、かつＧＰＣで測定される分子量分布（Ｍｗ／Ｍｎ）が１．５〜２．５であり、可視ゲルが５個以下である分岐状ブタジエン系重合体：
ここで、可視ゲルは、分岐状ブタジエン系重合体５ｇをトルエン２００ｍｌに溶解し、ろ紙で吸引ろ過した後、前記ろ紙に、０．４ｇのＣ．Ｉ．Ｓｏｌｖｅｎｔ Ｖｉｏｌｅｔ３６をトルエン８００ｍｌに溶解した染料溶液を滴下させて全体を着色した後、トルエンを蒸発させたろ紙を観察し、認められるゲルの数をいう。
［１１］前記［１］〜［８］のいずれか１項に記載の製造方法により得られる、前記［９］又は［１０］に記載の分岐状ブタジエン系重合体。
［１２］前記［９］〜［１１］のいずれか１項に記載の分岐状ブタジエン系重合体１００質量部に対し、フェノール系安定剤とリン系安定剤のうち少なくとも一種を０．０１〜２．０質量部、及び含イオウフェノール系化合物を０．０１〜２．０質量部含有する分岐状ブタジエン系重合体組成物。
［１３］前記［９］〜［１１］のいずれか１項に記載の分岐状ブタジエン系重合体１００質量部に対し、有機脂肪酸を０．０１〜０．５質量部含有する分岐状ブタジエン系重合体組成物。 As a result of intensive studies to solve the above problems, the present inventors have found that in the continuous method of a branched butadiene polymer, in order to suppress the generation of gel, the monomer is supplied to the polymerization reactor. The inventors have found that temperature is important and have completed the present invention.
That is, the present invention is as follows.
[1] 1,3-butadiene or 1,3-butadiene and an aromatic vinyl compound, and an inert solvent are continuously supplied to a polymerization reactor at a supply temperature of 30 ° C. or lower, and an organic lithium compound is continuously used as an initiator. Polymerization step to obtain an active end-containing linear butadiene polymer,
A coupling step in which the active terminal-containing linear butadiene-based polymer is continuously supplied to a coupling reactor, and a coupling agent represented by the following formula (1) is continuously added to continuously perform a coupling reaction; ,
A method for producing a branched butadiene-based polymer.

(In the formula (1), each R independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms. N is an integer of 0 or 1.)
[2] The branched butadiene-based polymer has a Mooney viscosity (ML _{1 + 4} ) at a measurement temperature of 100 ° C. of 25 ≦ ML _{1 + 4} ≦ 55, and a 5 wt% styrene solution viscosity (SV) measured at 25 ° C. of 25 ≦ 25. SV ≦ 50 (mPa · s) and the molecular weight distribution (Mw / Mn) measured by GPC is a branched butadiene-based polymer according to [1], which is 1.5 to 2.5. A method for producing a branched butadiene-based polymer.
[3] The branched butadiene heavy polymer according to [1] or [2], wherein the allene compound is continuously supplied to the polymerization reactor at a ratio of 50 to 350 ppm with respect to 1,3-butadiene. Manufacturing method of coalescence.
[4] The method for producing a branched butadiene polymer according to any one of [1] to [3], wherein the coupling agent in the coupling step is tetramethoxysilane or tetraethoxysilane.
[5] The method according to any one of [1] to [4], wherein at least one of the polymerization reactors and at least one of the coupling reactors are completely mixed reactors. A method for producing a branched butadiene-based polymer.
[6] The method for producing a branched butadiene polymer according to any one of [1] to [5], wherein the temperature at the top of the polymerization reactor is 120 ° C. or lower.
[7] The method for producing a branched butadiene polymer according to any one of [1] to [6], wherein the branched butadiene polymer is a branched polybutadiene.
[8] The method for producing a branched butadiene polymer according to any one of [1] to [6], wherein the branched butadiene polymer is a branched butadiene-styrene copolymer.
[9] An active-terminal-containing linear butadiene polymer obtained by polymerizing 1,3-butadiene or 1,3-butadiene and an aromatic vinyl compound in the presence of an inert solvent is represented by the following formula (1). A branched butadiene-based polymer obtained by a coupling reaction using a coupling agent,

(In the formula (1), each R independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms. N is an integer of 0 or 1.)
The supply temperature of 1,3-butadiene or 1,3-butadiene and an aromatic vinyl compound and an inert solvent to the polymerization reactor during the polymerization is 30 ° C. or less, and the Mooney viscosity (ML _{1 + 4 at} a measurement temperature of 100 ° C. ) Is 25 ≦ ML _{1 + 4} ≦ 55, 5 wt% styrene solution viscosity (SV) measured at 25 ° C. is 25 ≦ SV ≦ 50 (mPa · s), and molecular weight distribution (Mw / A branched butadiene-based polymer having a Mn) of 1.5 to 2.5.
[10] An active terminal-containing linear butadiene polymer obtained by polymerizing 1,3-butadiene or 1,3-butadiene and an aromatic vinyl compound in the presence of an inert solvent is represented by the following formula (1). A branched butadiene-based polymer obtained by a coupling reaction using a coupling agent,

(In formula (1), each R independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 1 to 10 carbon atoms. N is an integer of 0 or 1.)
The Mooney viscosity (ML _{1 + 4} ) at a measurement temperature of 100 ° C. is 25 ≦ ML _{1 + 4} ≦ 55, the 5 wt% styrene solution viscosity (SV) measured at 25 ° C. is 25 ≦ SV ≦ 50 (mPa · s), and A branched butadiene-based polymer having a molecular weight distribution (Mw / Mn) measured by GPC of 1.5 to 2.5 and 5 or less visible gels:
Here, the visible gel was prepared by dissolving 5 g of a branched butadiene-based polymer in 200 ml of toluene, suction filtering with filter paper, and then adding 0.4 g of C.I. I. The dye solution in which Solvent Violet 36 is dissolved in 800 ml of toluene is dropped to color the whole, and then the filter paper on which toluene is evaporated is observed, and the number of gels recognized is observed.
[11] The branched butadiene-based polymer according to [9] or [10], which is obtained by the production method according to any one of [1] to [8].
[12] With respect to 100 parts by mass of the branched butadiene polymer according to any one of [9] to [11], at least one of a phenol stabilizer and a phosphorus stabilizer is 0.01-2. A branched butadiene-based polymer composition containing 0.0 part by mass and 0.01 to 2.0 parts by mass of the sulfur-containing phenol-based compound.
[13] A branched butadiene-based heavy containing 0.01 to 0.5 parts by mass of an organic fatty acid with respect to 100 parts by mass of the branched butadiene-based polymer according to any one of [9] to [11]. Combined composition.

  ADVANTAGE OF THE INVENTION According to this invention, the continuous manufacturing method of the branched butadiene type polymer with which generation | occurrence | production of gel was reduced can be provided. Furthermore, it is possible to provide a continuous production method of a branched butadiene-based polymer having a broad molecular weight distribution, which does not contain a halogen compound, has reduced gel generation, and has excellent appearance.

（式（１）中、Ｒは、各々独立して、炭素数１〜１０のアルキル基又は炭素数６〜１０のアリール基を表す。ｎは０又は１の整数である。） Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with appropriate modifications within the scope of the gist thereof.
〔Production method〕
In the method for producing a branched butadiene polymer of the present embodiment, 1,3-butadiene or 1,3-butadiene and an aromatic vinyl compound and an inert solvent are supplied to a polymerization reactor at an average temperature of 30 ° C. or lower. A polymerization step of continuously polymerizing an organolithium compound as an initiator to obtain an active end-containing linear butadiene polymer, and continuously supplying the active end-containing linear butadiene polymer to the coupling reactor, A coupling step of continuously adding a coupling agent represented by the formula (1) and continuously performing a coupling reaction.

(In the formula (1), each R independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms. N is an integer of 0 or 1.)

<Polymerization process>
In the production method of this embodiment, in the polymerization step, a monomer (1,3-butadiene alone or 1,3-butadiene and an aromatic vinyl compound) and an inert solvent are continuously supplied to the polymerization reactor, and organic A linear butadiene-based polymer having an active end is obtained by continuously (co) polymerizing monomers using a lithium compound as an initiator.
The linear butadiene-based polymer is a homopolymer of 1,3-butadiene or a copolymer of 1,3-butadiene and an aromatic vinyl compound.
In the production method of this embodiment, a raw material monomer and an inert solvent are supplied to the polymerization reactor, and the monomer is continuously polymerized to finally obtain a polymer having a wide molecular weight distribution. Can do.

(Raw material supply temperature, polymerization temperature)
In the production method of this embodiment, from the viewpoint of suppressing the formation of gel, in the polymerization step, it is necessary that the supply temperature of the monomer and the inert solvent to the polymerization reactor is 30 ° C. or less. It is preferably 30 ° C, more preferably 2 ° C to 25 ° C, and still more preferably 5 ° C to 20 ° C. Here, the supply temperature is the average temperature of the monomer and inert solvent mixture in the piping at the reactor inlet when supplying the monomer and the inert solvent to the reactor. In order to allow the polymerization reaction to proceed rapidly, the supply temperature is preferably 0 ° C. or higher, and the gel is kept as low as possible within the range that does not affect the monomer conversion at the end of the polymerization reaction. In order to suppress generation, the supply temperature is preferably 30 ° C. or lower.
From the viewpoint of sufficiently ensuring the reaction rate of the coupling agent with respect to the active terminal after the completion of the polymerization, the tower top temperature of the polymerization reactor is preferably 120 ° C. or lower. Here, the tower top temperature refers to the average temperature of the polymer solution in the piping at the outlet of the reactor. In order to maintain the conversion rate of the polymerization reaction, the tower top temperature is preferably 60 ° C. or higher.

(Polymerization reactor)
In the production method of the present embodiment, the shape of the polymerization reactor is not particularly limited, and for example, a tank type reactor with a stirrer, a tube type, a column type reactor or the like is used.
The form of the polymerization reactor is not particularly limited. For example, the polymerization reactor may be a complete mixing reactor or a plug flow reactor. The reactor includes a reactor provided in the middle of a pipe to be transferred. The plug flow reactor is not particularly limited, and includes a static mixer and a dynamic mixer having a stirring function.
In the production method of the present embodiment, one or two or more reactors connected in parallel or in series can be used.
From the viewpoint of preventing gel formation, at least one of the polymerization reactors is preferably a fully mixed reactor.

(Aromatic vinyl compound)
In the production method of the present embodiment, the aromatic vinyl compound may be any monomer that is copolymerizable with a conjugated diene compound, particularly 1,3-butadiene, and is not particularly limited. Examples include p-methylstyrene, α-methylstyrene, vinylethylbenzene, vinylxylene, vinylnaphthalene, diphenylethylene and the like. Among these, styrene is preferable from the viewpoint of industrial availability. Moreover, you may use polyfunctional aromatic vinyl compounds, such as divinylbenzene for controlling a branch from a viewpoint of preventing the cold flow of the polymer obtained by a superposition | polymerization process. These may be used alone or in combination of two or more.

(Organic lithium compound)
In the production method of the present embodiment, the organolithium compound used as the polymerization initiator is not particularly limited, and examples thereof include a monoorganolithium compound and a polyfunctional organolithium compound.
Examples of monoorganolithium compounds include, but are not limited to, for example, low molecular weight compounds, solubilized oligomeric organolithium compounds, compounds having a carbon-lithium bond in the bonding mode between an organic group and lithium, and nitrogen- Examples thereof include a compound having a lithium bond.
Although it does not specifically limit as a carbon-lithium compound, For example, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, n-hexyl lithium, benzyl lithium, phenyl lithium, stilbene lithium, etc. are mentioned. .
The compound having a nitrogen-lithium bond is not particularly limited. For example, lithium dimethylamide, lithium diethylamide, lithium dipropylamide, lithium di-n-hexylamide, lithium diisopropylamide, lithium hexamethyleneimide, lithium Examples include pyrrolidide, lithium piperidide, lithium heptamethylene imide, lithium morpholide and the like.

Although it does not specifically limit as a polyfunctional organolithium compound, For example, the reaction material of 1, 4- dilithiobutane, sec-butyl lithium, and diisopropenyl benzene, 1,3,5-trilithiobenzene, n- Examples include a reaction product of butyl lithium, 1,3-butadiene and divinylbenzene, a reaction product of n-butyl lithium and a polyacetylene compound, and the like.
Although it does not specifically limit as an organic alkali metal compound, For example, US Patent 5,708,092 specification, British Patent 2,241,239 specification, US Patent 5,527,753 The well-known thing currently disclosed by No. specification etc. can also be used.
As the organic lithium compound, n-butyllithium and sec-butyllithium are preferable from the viewpoint of industrial availability and ease of control of the polymerization reaction.
An organic lithium compound may be used individually by 1 type, and may use 2 or more types together.

(Polymerization solvent)
In the production method of this embodiment, the monomer polymerization reaction is carried out in an inert solvent.
The inert solvent is not particularly limited, and examples thereof include hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. Specific examples include, but are not limited to, aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane; benzene, Examples thereof include aromatic hydrocarbons such as toluene and xylene, and hydrocarbons composed of mixtures thereof.

(Allen)
In the production method of the present embodiment, it is preferable that allenes are allowed to coexist in the polymerization system together with the monomer and the inert solvent from the viewpoint of improving the effect of suppressing gel formation. On the other hand, in order to sufficiently advance the coupling reaction and obtain a necessary and sufficient degree of branching, it is preferable to control the total content concentration (mass) of allenes in the polymerization system within a specific range. The total content concentration (mass) of allenes is preferably 50 ppm to 350 ppm, more preferably 60 ppm to 300 ppm, and still more preferably 70 ppm to 250 ppm with respect to the monomer.
Examples of allenes include propadiene and 1,2-butadiene.

(Other additives)
For the purpose of randomly copolymerizing butadiene and aromatic vinyl compounds, or for the purpose of controlling the amount of 1,2-vinyl bonds in the butadiene bond unit, and for the purpose of accelerating the polymerization reaction, polar Compounds can be added.
The polar compound is not particularly limited, and examples thereof include tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, dimethoxybenzene, 2,2-bis (2-oxolanyl) propane, and the like. Ethers; tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, quinuclidine; potassium-tert-amylate, potassium-tert-butyrate, sodium-tert-butyrate, sodium amylate, etc. Alkali metal alkoxide compounds of the above; phosphine compounds such as triphenylphosphine can be used.
These polar compounds may be used alone or in combination of two or more.
The usage-amount of a polar compound is not specifically limited, It can select according to the objective etc. Specifically, it is preferable that it is 0.01-100 mol with respect to 1 mol of polymerization initiators. Such a polar compound (vinylating agent) can be used in an appropriate amount depending on the desired amount of vinyl bonds as a regulator of the microstructure of the polymer butadiene portion. Many polar compounds simultaneously have an effective randomizing effect in the copolymerization of butadiene and an aromatic vinyl compound, and can be used as an adjustment of the distribution of the aromatic vinyl compound and an adjuster of the amount of styrene block. As a method for randomizing butadiene and an aromatic vinyl compound, for example, a copolymerization reaction is started with styrene and a part of 1,3-butadiene, and the remaining 1,3-butadiene is mixed during the copolymerization reaction. You may use the method of adding intermittently.

(Linear butadiene polymer containing active ends)
In the production method of the present embodiment, in the polymerization step, a linear butadiene polymer containing active ends (active end containing linear butadiene polymer) is obtained.
The microstructure of the butadiene portion in the linear butadiene-based polymer is not particularly limited, but may have a 1,2-vinyl content of 10 to 80% and a cis-1,4-content of 10 to 85%. preferable. In particular, those having a 1,2-vinyl content of 10 to 25% are preferred for use as a modifier for styrene resins.
With respect to the method for adjusting the 1,2-vinyl content, polar compounds as described above can be used. For example, in the polymerization step, the polymerization can be achieved by supplying an ether such as tetrahydrofuran (THF) into the reactor together with a monomer and an inert solvent.
Here, when the aromatic vinyl compound in the production method of the present embodiment is styrene, the vinyl bond amount (1,2-bond amount) in the butadiene bond unit is determined by the Hampton method (RR Hampton, Analytical Chemistry, 21, 923 (1949)), the vinyl bond amount (1,2-bond amount) in the butadiene bond unit can be determined.
The amount of bonded aromatic vinyl in the linear butadiene-based polymer is not particularly limited, but is preferably 0 to 20% by mass, and more preferably 1 to 10% by mass.
Here, the amount of bonded aromatic vinyl can be measured by ultraviolet absorption of a phenyl group.

When two or more types of monomers are used in the present embodiment, the active terminal-containing linear butadiene-based polymer (copolymer) may be a random copolymer or a block copolymer.
The composition distribution of each monomer unit in the random copolymer chain is not particularly limited. For example, a completely random copolymer close to a statistical random composition, a taper (gradient) in which the composition is distributed in a tapered shape. A random copolymer etc. are mentioned. The bonding mode of butadiene, that is, the composition such as 1,4-bonds and 1,2-bonds may be uniform or distributed.
As the block copolymer, for example, a 2 type block copolymer (diblock) composed of 2 blocks, a 3 type block copolymer (triblock) composed of 3 blocks, and a 4 type block copolymer composed of 4 blocks Examples include coalescence (tetrablock). For example, when a block composed of an aromatic vinyl compound such as styrene is represented by “S” and a block composed of butadiene is represented by “B”, an S—B2 type block copolymer or an S—B—S3 type block copolymer S-B-S-B4 type block copolymer and the like.
In the above formula, the composition of each block is not necessarily uniform. For example, the block B may be a copolymer of butadiene and an aromatic vinyl compound.
Similarly, in the above formula, the boundaries of the blocks do not necessarily have to be clearly distinguished. For example, when the block B is a copolymer of butadiene and an aromatic vinyl compound, the aromatic vinyl compound in the block B may be distributed uniformly or in a tapered shape. Further, a plurality of portions where the aromatic vinyl compound is uniformly distributed and / or portions where the aromatic vinyl compound is distributed in a tapered shape may coexist in the block B. Furthermore, a plurality of segments having different aromatic vinyl compound contents may coexist in the block B. When a plurality of blocks S and blocks B are present in the copolymer, the structures such as molecular weight and composition thereof may be the same or different. Here, the composition distribution of the monomer can be measured by an osmium acid decomposition method or an ozonolysis method.

（式（１）中、Ｒは、各々独立して、炭素数１〜１０のアルキル基又は炭素数６〜１０のアリール基を表す。ｎは０又は１の整数である。）
本実施形態の製造方法では、前記カップリング反応を連続的に行うことにより、分子量分布の広い重合体を得ることができる。 <Coupling process>
The manufacturing method of this embodiment includes a coupling step.
In the coupling step, a branched butadiene polymer is continuously obtained by continuously adding and reacting a coupling agent represented by the following formula (1) to the active terminal of the linear butadiene polymer.

(In the formula (1), each R independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms. N is an integer of 0 or 1.)
In the production method of this embodiment, a polymer having a wide molecular weight distribution can be obtained by continuously performing the coupling reaction.

(Coupling agent)
In the production method of the present embodiment, by using the coupling agent represented by the formula (1), a branched butadiene-based polymer that does not contain a halogen compound and has an excellent appearance can be produced.
Examples of the coupling agent include, but are not limited to, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, and ethyltriethoxysilane.
Among these, tetramethoxysilane and tetraethoxysilane are preferable from the viewpoint of industrial availability and ease of branching reaction.
These compounds may be used as they are, or may be used after being dissolved in a solvent. However, when using a solvent, a hydrocarbon solvent which is inactive with respect to the active terminal of the linear butadiene polymer may be used. preferable. Examples of the hydrocarbon solvent include benzene, toluene, cyclohexane, n-hexane and the like.

(Coupling agent addition amount)
In the production method of the present embodiment, the amount of the coupling agent added is not particularly limited, but is preferably 0.1 to 0.6 mol with respect to 1 mol of the polymerization initiator described above, and 0.13 More preferably, it is -0.5 mol, and it is further more preferable that it is 0.15-0.4 mol. In order for the branched butadiene-based polymer to have a sufficient degree of branching, it is preferably 0.1 mol or more, and a coupling agent is added in an amount more than necessary, so that the degree of branching is not reduced and the cost is not increased. It is preferable to make it 6 mol or less.

(Coupling reactor)
In the production method of this embodiment, the shape of the coupling reactor is not particularly limited, and for example, a tank type reactor with a stirrer, a tube type, a tower type, or the like is used.
The form of the coupling reactor is not particularly limited, and may be, for example, a complete mixing type reactor or a plug flow type reactor. The reactor includes a reactor provided in the middle of a pipe to be transferred. The plug flow reactor is not particularly limited, and includes a static mixer and a dynamic mixer having a stirring function.
In the production method of the present embodiment, one or two or more reactors connected in parallel or in series can be used.
The coupling reactor is preferably a fully mixed reactor from the viewpoint of sufficient mixing and reaction time.

(Coupling reaction temperature)
Although the coupling reaction temperature in the manufacturing method of this embodiment is not specifically limited, It is preferable that it is 50-130 degreeC, and it is more preferable that it is 60-120 degreeC. In order to advance the coupling reaction with high efficiency without deactivating the active terminal, the reaction is preferably carried out at 130 ° C. or lower, and the reaction is preferably carried out at 50 ° C. or higher from the viewpoint of the coupling reaction rate. Here, the coupling reaction temperature is an average temperature in the coupling reactor.

(Coupling reaction time)
The reaction time when the coupling agent is reacted with the active terminal of the linear butadiene-based polymer is not particularly limited, but from the viewpoint of the coupling reaction rate, the reaction time is preferably 30 seconds to 120 minutes, more preferably. Is from 1 minute to 60 minutes, more preferably from 2 minutes to 45 minutes. Here, the coupling reaction time refers to the average residence time of the active end-containing linear butadiene polymer in the coupling step.

<Acquisition method of branched butadiene-based polymer>
In the production method of the present embodiment, the method for obtaining the branched butadiene-based polymer from the polymer solution is not particularly limited, and a known method can be used. For example, after separating the solvent by steam stripping or the like, the polymer is filtered off, further dehydrated and dried to obtain the polymer, concentrated in a flushing tank, and further devolatilized by a vent extruder or the like. The method, the method of devolatilizing directly with a drum dryer etc. are mentioned.

<Reactor arrangement>
In the production method of the present embodiment, the arrangement method of the reactor is not particularly limited, and reactors connected in parallel or in series can be used. From the viewpoint of narrowing the molecular weight distribution of the obtained polymer, the reactor Are preferably connected in series, at least one of which is a polymerization reactor, and at least one of the other reactors is a coupling reactor.

<Other processes>
The manufacturing method of this embodiment may include steps other than the polymerization step and the coupling step. Preferable steps include a step for removing impurities and a step for deactivating or neutralizing the reaction.

(Removal of impurities)
For example, treating an acetylene or the like contained as an impurity in a monomer and an inert solvent with an organometallic compound before being subjected to a polymerization reaction tends to yield a polymer having a high concentration of active terminals. Further, it is preferable because a high coupling rate tends to be achieved.

(Deactivation, neutralization)
Moreover, after performing a coupling reaction, you may provide the deactivation process and neutralization process which add a deactivator, a neutralizing agent, etc. to the solution of the obtained branched butadiene type polymer.
The quenching agent is not particularly limited, and examples thereof include water, alcohols such as methanol, ethanol, and isopropanol.
The neutralizing agent is not particularly limited, and examples thereof include carboxylic acids such as benzoic acid, stearic acid, oleic acid, and versatic acid (a mixture of carboxylic acids having 9 to 11 carbon atoms, mainly 10 and having many branches). Examples thereof include an acid, an inorganic acid aqueous solution, and carbon dioxide gas.

(Hydrogenation reaction)
In the manufacturing method of this embodiment, you may provide the process which converts all or one part of a double bond into a saturated hydrocarbon by further hydrogenating a branched butadiene type polymer in an inert solvent. Providing such a process is preferable from the viewpoint of improving heat resistance and weather resistance, and preventing deterioration of the product when processed at high temperatures, and as a result, the product is more excellent in various applications such as automobile applications. Demonstrate performance.
More specifically, the hydrogenation rate of unsaturated double bonds based on butadiene (hereinafter sometimes referred to as “hydrogenation rate”) can be arbitrarily selected according to the purpose, and is not particularly limited.
When used as a resin-modifying rubber such as HIPS, it is preferable that the double bond of the butadiene portion partially remains. From this viewpoint, the hydrogenation rate of the butadiene portion in the branched butadiene-based polymer is preferably 3 to 70%, more preferably 5 to 65%, and further preferably 10 to 60%. preferable.
When the branched butadiene-based polymer contains a monomer unit based on an aromatic vinyl compound, the hydrogenation rate of the aromatic double bond based on the aromatic vinyl compound is not particularly limited. However, it is preferably 50% or less, more preferably 30% or less, and even more preferably 20% or less. The hydrogenation rate can be determined by a nuclear magnetic resonance apparatus (NMR) or the like.
The method of hydrogenation is not specifically limited, A well-known method can be utilized. As a particularly suitable hydrogenation method, a method of hydrogenation by blowing gaseous hydrogen into a polymer solution in the presence of a catalyst may be mentioned. Catalysts include heterogeneous catalysts such as catalysts in which noble metals are supported on porous inorganic materials; catalysts in which salts such as nickel and cobalt are solubilized and reacted with organoaluminum, etc., catalysts using metallocenes such as titanocene, etc. And homogeneous catalysts. Among these, a titanocene catalyst is particularly preferable from the viewpoint of selecting mild hydrogenation conditions. The hydrogenation of the aromatic group can be performed by using a noble metal supported catalyst.
Specific examples of the hydrogenation catalyst include (1) a supported heterogeneous hydrogenation catalyst in which a metal such as Ni, Pt, Pd, or Ru is supported on carbon, silica, alumina, diatomaceous earth, or the like. (2) Ni, A so-called Ziegler type hydrogenation catalyst using a transition metal salt such as an organic acid salt such as Co, Fe or Cr or an acetylacetone salt and a reducing agent such as organoaluminum, and (3) an organic metal such as Ti, Ru, Rh or Zr. Examples include so-called organometallic complexes such as compounds. For example, as a hydrogenation catalyst, JP-B-42-8704, JP-B-43-6636, JP-B-63-4841, JP-B-1-37970, JP-B-1-53851, JP-B-2- Known hydrogenation catalysts described in Japanese Patent No. 9041 and Japanese Patent Laid-Open No. 8-109219 can be used. A preferred hydrogenation catalyst is a reaction mixture of a titanocene compound and a reducing organometallic compound.

(Addition of additives, etc.)
In the production method of the present embodiment, a rubber stabilizer is added to the obtained branched butadiene-based polymer from the viewpoint of suppressing the formation of gel due to the thermal history of an extruder or the like, or from the viewpoint of improving the stability during processing. It is preferable to do.
It does not specifically limit as a stabilizer for rubber | gum, Well-known things, such as a phenol type stabilizer, a phosphorus stabilizer, and a sulfur-containing phenol type compound, can be used.
The phenolic stabilizer is not particularly limited, and examples thereof include 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, and 2,6-di- tert-butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-i-butylphenol, n-octadecyl-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl ) Propionate, 2,2-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2-ethylene-bis- (4-methyl-6-tert-butylphenol) and the like.
The phosphorus stabilizer is not particularly limited, and examples thereof include tris (nonylphenyl) phosphite, tris- (2,4-di-tert-butylphenyl) phosphite, and cyclic neopentanetetraylbis (octadecyl phosphite). ) Etc.
The sulfur phenol-based compound is not particularly limited, and examples thereof include 2,4-bis (n-octylthiomethyl) -6-methylphenol and 2,4-bis (2 ′, 3′-di-hydroxypropylthiomethyl). ) -3,6-di-methylphenol, 2,4-bis (2'-acetyloxyethylthiomethyl) -3,6-di-methylphenol.

（式（１）中、Ｒは、各々独立して、炭素数１〜１０のアルキル基又は炭素数６〜１０のアリール基を表す。ｎは０又は１の整数である。） [Branched butadiene polymer]
Hereinafter, the branched butadiene-based polymer of this embodiment will be described. The production method of the present embodiment is not limited to the production method of obtaining the branched butadiene polymer of the following embodiment, but the branched butadiene polymer of the following embodiment is obtained. Is preferred.
The branched butadiene polymer of the present embodiment represents an active terminal-containing linear butadiene polymer obtained by polymerizing 1,3-butadiene or 1,3-butadiene and an aromatic vinyl compound by the following formula (1). A branched butadiene-based polymer obtained by a coupling reaction using a coupling agent that has a Mooney viscosity (ML _{1 + 4} ) at a measurement temperature of 100 ° C. of 25 ≦ ML _{1 + 4} ≦ 55 and measured at 25 ° C. Branched butadiene having a viscosity of 5 wt% styrene solution (SV) of 25 ≦ SV ≦ 50 (mPa · s) and a molecular weight distribution (Mw / Mn) measured by GPC of 1.5 to 2.5 Based polymer.

(In the formula (1), each R independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms. N is an integer of 0 or 1.)

<Branch structure>
The branched butadiene polymer of the present embodiment represents an active terminal-containing linear butadiene polymer obtained by polymerizing 1,3-butadiene or 1,3-butadiene and an aromatic vinyl compound by the following formula (1). It has a branched structure centered on silicon atoms derived from the coupling agent, and thus does not contain a halogen compound and is excellent in appearance. .
Here, the degree of branching is the number of bonds of the linear butadiene polymer bonded to the central silicon atom in the branched butadiene polymer of the present embodiment, and the Mooney viscosity and 5 wt% styrene solution viscosity described later. It can be evaluated indirectly based on the relationship. For example, when the 5 wt% styrene solution viscosity of a linear butadiene polymer and a branched butadiene polymer showing the same Mooney viscosity is compared, the branched butadiene polymer shows a much lower solution viscosity.
In addition, as described above, the amount of allenes added in the polymerization reaction affects the degree of branching. Therefore, the production condition of adding 350 ppm or less of allenes during the polymerization is indirectly related to the branched structure of the branched butadiene-based polymer. Since it can be said that it is specified, the branched butadiene-based polymer of this embodiment is preferably obtained by a production method in which 350 ppm or less of allenes are added during polymerization.

(Mooney viscosity)
The branched butadiene polymer of the present embodiment has a Mooney viscosity (ML _{1 + 4} ) at a measurement temperature of 100 ° C. of 25 to 55. When the Mooney viscosity (ML _{1 + 4} ) is 25 or more, cold flow can be further suppressed, and when the Mooney viscosity (ML _{1 + 4} ) is 55 or less, the solution viscosity (for example, a 5 wt% styrene solution viscosity (described later) ( SV) etc.) is kept low.
The preferable Mooney viscosity (ML _{1 + 4} ) is 27 to 52, more preferably 30 to 50.

(5 wt% styrene solution viscosity (SV))
The branched butadiene polymer of the present embodiment has a 5 wt% styrene solution viscosity (SV) at a measurement temperature of 25 ° C. of 25 to 50 (mPa · s). When the SV is 25 mPa · s or more, it becomes easy to control the rubber particle diameter so as not to be too small when used for a high gloss styrene resin, and sufficient impact resistance can be ensured, and at 50 mPa · s or less. As a result, there is an effect that the stirring power for controlling the particle diameter can be suppressed during the polymerization of the high gloss styrene resin. SV is preferably 25 to 45 (mPa · s), more preferably 25 to 40 (mPa · s).

(Molecular weight, molecular weight distribution)
The branched butadiene-based polymer of the present embodiment has a polystyrene-equivalent weight average molecular weight (Mw) obtained by gel permeation chromatography (GPC) measurement, preferably 50,000 to 600,000, more preferably 70,000. ˜500,000, more preferably 100,000 to 400,000. From the viewpoint of suppressing the cold flow of the obtained branched butadiene-based polymer, the above lower limit value is preferable, and from the correlation with the solution viscosity of the branched butadiene-based polymer, the above upper limit value is preferable.
Moreover, from the viewpoint of improving productivity, the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.5 to 2.5. The molecular weight distribution can vary depending on the production conditions of the branched butadiene-based polymer, and one of the conditions is whether it is produced by a continuous method or a batch method. As described above, since the continuous type generally has a wider molecular weight distribution than the batch type, it can be said that the production condition of the continuous type indirectly specifies the molecular weight distribution of the branched butadiene-based polymer. The branched butadiene polymer is preferably obtained by a continuous production method.

(gel)
The branched butadiene-based polymer of the present embodiment has a feature that there are few gels.
Although the above characteristics can be evaluated to some extent by a visible gel described later, as described above, the supply temperature to the polymerization reactor such as a monomer affects the generation of the gel, so It can also be specified indirectly by the supply temperature.
That is, the branched butadiene-based polymer of the present embodiment is obtained by a production method in which the supply temperature to a polymerization reactor such as a monomer is 30 ° C. or less, or the number of visible gels is 5 or less. When it uses for HIPS, there exists an effect of being able to suppress clogging of a filter at the time of a HIPS manufacturing process, and being able to reduce the irregularity at the time of forming into a sheet form.

The first branched butadiene polymer of the present embodiment is such that the supply temperature of 1,3-butadiene or 1,3-butadiene and an aromatic vinyl compound and an inert solvent to the polymerization reactor during polymerization is 30 ° C. It is obtained by the following manufacturing method.
The production conditions indirectly indicate that there are few gels in the branched butadiene-based polymer.

The second branched butadiene polymer of this embodiment has 5 or less visible gels. Here, the visible gel means that 5 g of a branched butadiene polymer is dissolved in 200 mL of toluene, suction filtered with a filter paper, and then 0.4 g of C.I. I. This refers to the number of gels observed by observing the filter paper from which toluene was evaporated after dripping several drops of a dye solution obtained by dissolving Solvent Violet 36 in 800 mL of toluene and coloring the whole.
Further, when the recognized gel size is less than 0.5 mm as class A, 0.5 mm or more and less than 1.0 mm as class B, and 1.0 mm or more as class C, during the HIPS manufacturing process From the standpoint of suppressing filter clogging of the filter and reducing fuzz when molded into a sheet, it is more preferable that the number of gels is 5 or less, 2 or less B-class gels, and no C-class gel is present. It is more preferable that the number of is 2 or less and all are class A.

[Branched butadiene-based polymer composition]
The branched butadiene-based polymer composition of the present embodiment is 0.01 to 2.0 parts by mass of at least one of a phenol-based stabilizer and a phosphorus-based stabilizer with respect to 100 parts by mass of the branched butadiene-based polymer. And a branched butadiene-based polymer composition containing 0.01 to 2.0 parts by mass of a sulfur-containing phenol-based compound.
The phenol-based stabilizer is not particularly limited, and examples thereof include 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, and 2,6-di-tert. -Butyl-4-n-butylphenol, 2,6-di-tert-butyl-4-i-butylphenol, n-octadecyl-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) Examples include propionate, 2,2-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2-ethylene-bis- (4-methyl-6-tert-butylphenol), and the like.
The phosphorus stabilizer is not particularly limited. For example, tris (nonylphenyl) phosphite, tris- (2,4-di-tert-butylphenyl) phosphite, cyclic neopentanetetraylbis (octadecylphosphite) Etc.
The sulfur phenol compound is not particularly limited, and examples thereof include 2,4-bis (n-octylthiomethyl) -6-methylphenol and 2,4-bis (2 ′, 3′-di-hydroxypropylthiomethyl). -3,6-di-methylphenol, 2,4-bis (2'-acetyloxyethylthiomethyl) -3,6-di-methylphenol, and the like.
The total content of the phenol-based stabilizer and the phosphorus-based stabilizer is 0.01 to 2.0 parts by mass with respect to 100 parts by mass of the branched butadiene-based polymer, from the viewpoint of thermal stability improvement effect and cost. Preferably there is.
The content of the sulfur-containing phenol-based compound is preferably 0.01 to 2.0 parts by mass in total from the viewpoint of improving the thermal stability and coloring / odor.

The branched butadiene polymer composition of the present embodiment is a branched butadiene polymer composition containing 0.01 to 0.5 parts by mass of an organic fatty acid with respect to 100 parts by mass of the branched butadiene polymer. Is also included.
Organic fatty acid is not particularly limited, capric acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, palmitoleic acid, margaric acid, stearic acid, oleic acid, vaccenic acid, linoleic acid, succinic acid, citric acid, malic acid Etc.
The content of the organic fatty acid is 0 in total with respect to 100 parts by mass of the branched butadiene-based polymer from the viewpoint of not inhibiting the radical polymerizability during the production of HIPS while ensuring the releasability of the rubber in the extruder. It is preferable that it is 0.01-0.5 mass part.

[Styrene resin modifying rubber composition]
When the branched butadiene polymer obtained by this technology is used for styrene resin modification applications such as high impact polystyrene (HIPS), mass ABS, and transparent MBS resin, the branched butadiene polymer obtained by this technology is It may be used alone or, if necessary, may be blended with other rubbers. Examples of other rubber include linear polybutadiene, branched polybutadiene by batch polymerization, linear butadiene-styrene random copolymer, branched butadiene-styrene random copolymer by batch polymerization, and linear butadiene-styrene block copolymer. Examples thereof include branched butadiene-styrene block copolymers obtained by polymerization and batch polymerization. The SV of other rubbers is preferably 25 to 200 mPa · s, more preferably 25 to 100 mPa · s from the viewpoint of emphasizing the appearance such as gloss and transparency, and a high impact resistance. From the point of view, it is 100 to 200 mPa · s. When used for high gloss HIPS or mass ABS, it is more preferable to use a linear butadiene-styrene block copolymer or a branched butadiene-styrene block copolymer by batch polymerization as the other rubber.
As a method for producing the styrene-based resin, any method such as solution polymerization, mass polymerization, and mass-suspension polymerization may be used. In the styrene resin polymerization method, a radical initiator may be used, or polymerization may be performed by a thermal radical without using a radical initiator.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples. The sample was analyzed by the method shown below.
(1) Mooney Viscosity Mooney viscosity was measured using a Mooney viscometer ("VR1132" manufactured by Ueshima Seisakusho Co., Ltd.) in accordance with JIS K6300 (ISO 289-1). The measurement temperature was 100 ° C.
First, after preheating the sample for 1 minute, the rotor was rotated at 2 rpm, and the torque after 4 minutes was measured to obtain the Mooney viscosity (ML _{1 + 4} ).

(2) Molecular weight distribution (Mw / Mn)
A chromatogram was measured using a GPC measuring apparatus (HLC-8320GPC manufactured by Tosoh Corporation) in which three columns using polystyrene gel as a filler were connected, and a weight average molecular weight (based on a calibration curve using standard polystyrene) Mw) and number average molecular weight (Mn) were determined, and molecular weight distribution (Mw / Mn) was calculated. Tetrahydrofuran (THF) was used as the eluent. As the column, a guard column: TSKguardcolumn SuperMP (HZ) -H manufactured by Tosoh Corporation, and a column: TSKgel SuperMultipore HZ-H manufactured by Tosoh Corporation were connected in series were used. An RI detector (manufactured by Tosoh Corporation, “HLC8320”) was used under the conditions of an oven temperature of 40 ° C. and a THF flow rate of 1.0 mL / min. 10 mg of a sample for measurement was dissolved in 20 mL of THF to prepare a measurement solution, and 200 μL of the measurement solution was injected into a GPC measurement device and measured.

(3) Viscosity of 5 wt% styrene solution (SV)
2.385 g of the branched polymer was dissolved in 50 mL of styrene and measured at 25 ° C. using a Cannon Fenceke viscometer.

(4) Visible gel A 500 mL conical beaker was added with a rotor, 5 g of a branched butadiene polymer, and 200 mL of toluene, and stirred for 2 hours with a magnetic stirrer to dissolve the rubber. Thereafter, a Buchner funnel was laid with a 70 mm diameter filter paper of JIS P3801, and the dissolved rubber solution was suction filtered. After filtration of the total amount, the conical beaker was washed with 20 mL of toluene, and the washing was suction filtered with the above-mentioned filter paper. After completion of the filtration, a dye solution (in which 0.4 g of CI Solvent Violet 36 was dissolved in 800 mL of toluene) was dropped onto the filter paper with a dropper on the filter paper so that the whole was colored. Observe the filter paper from which the solvent has been evaporated, and the recognized gel size is less than 0.5 mm for class A, 0.5 mm to less than 1.0 mm for class B, and 1.0 mm or more for class C. When the number of gels is 2 or less and all are A grades, the visible gel level is 1 grade, the number of gels is 5 or less, 2 or less B grade gels, and there is no C grade gel Visible gel level that is not first grade and visible gel level is second grade, and the number of gels is 8 or less and no more than 3 grade C gels that are not visible gel level first grade or second grade. One or more was evaluated as a visible gel level 4 grade.

(5) Appearance (b value)
A branched butadiene polymer sample having a length of 4 cm, a width of 4 cm and a thickness of 2 cm was prepared by press molding, and the b value in the thickness direction was measured with a color difference meter. The measurement was performed by reflection measurement using NDJ-400 manufactured by Nippon Denshoku Industries Co., Ltd.

[Example 1]
An autoclave (a tank with a stirrer) having an internal volume of 11 L, an internal height-to-diameter ratio (L / D) of 4, an inlet at the bottom, an outlet at the top, a stirrer and a temperature adjusting jacket Two reactors were connected in series, and the first reactor was a polymerization reactor and the second reactor was a coupling reactor.
In advance, impurities such as moisture were removed, 1,3-butadiene was mixed at 42.2 g / min, 1,2-butadiene at 0.008 g / min, and n-hexane at 198.8 g / min. Was continuously fed to the bottom of the first reactor while adjusting the temperature to 15 ° C. Further, n-butyllithium as a polymerization initiator was supplied to the bottom of the first reactor at a rate of 1.2 mmol / min, and the polymerization reaction was continued so that the internal temperature of the reactor outlet was 100 ° C. .
The temperature of the second reactor is kept at 100 ° C., and a linear butadiene polymer solution flowing out from the top of the first reactor is continuously fed from the bottom, and tetramethoxysilane is further added as a coupling agent at 0.31 mmol / min. Was added from the bottom of the second reactor at a rate of To the branched butadiene polymer solution flowing out from the top of the second reactor, n-octadecyl-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate, 2,4- Bis [(octylthio) methyl] -O-cresol, water, and stearic acid are continuously added to give 0.1 g, 0.1 g, 10.0 g, and 0.035 g, respectively, per 100 g of the branched butadiene polymer. Further, carbon dioxide gas was continuously added at a molar ratio of 1: 1.5 with respect to the added n-butyllithium to complete the coupling reaction. The resulting branched butadiene-based polymer solution was desolvated by steam stripping, and residual moisture was removed with an open roll to obtain Sample A.
As a result of analyzing sample A, the Mooney viscosity at 100 ° C. was 42, and the viscosity of a 5 wt% styrene solution was 35 mPa · s. The molecular weight distribution was 1.75, the visible gel level was first grade, and the appearance (b value) was 3.2. The analysis results of Sample A are shown in Table 2.

[Example 2]
Sample B was obtained in the same manner as in the preparation of Sample A, except that the amount of 1,2-butadiene added was 0.017 g / min.
As a result of analyzing Sample B, the Mooney viscosity at 100 ° C. was 29, and the viscosity of a 5% by weight styrene solution was 34 mPa · s. The molecular weight distribution was 1.92, the visible gel level was first grade, and the appearance (b value) was 3.5. The analysis result of Sample B is shown in Table 1.

[Comparative Example 1]
Sample C was obtained in the same manner as in the preparation of Sample A except that the addition temperature of the 1,3-butadiene / n-hexane mixed solution was changed to 40 ° C.
As a result of analyzing Sample C, the Mooney viscosity at 100 ° C. was 40, and the viscosity of a 5 wt% styrene solution was 34 mPa · s. The molecular weight distribution was 1.84, the visible gel level was tertiary, and the appearance (b value) was 3.6. The analysis result of Sample C is shown in Table 1.

[Comparative Example 2]
Sample D was obtained in the same manner as in the preparation of Sample A, except that tetraglycidyl-1,3-bisaminomethylcyclohexane was used as the coupling agent and the addition amount was 0.25 mmol / min.
As a result of analyzing sample D, the Mooney viscosity at 100 ° C. was 49, and the viscosity of a 5 wt% styrene solution was 39 mPa · s. The molecular weight distribution was 1.81, the visible gel level was grade 2, and the appearance (b value) was 8.2. The analysis result of Sample D is shown in Table 1.

As shown in Table 1, Samples A and B (Examples 1 and 2) with a supply temperature of 15 ° C. had a smaller amount of visible gel than Sample C (Comparative Example 1) with a supply temperature of 40 ° C., and the supply temperature It was confirmed that the gel amount was suppressed by lowering. Samples A and B (Examples 1 and 2) using tetramethoxysilane as a coupling agent have a lower b value than the sample D (Comparative Example 2) using an epoxy coupling agent, and the appearance is improved. It was confirmed to be excellent. Further, Sample B (Example 2) in which 400 ppm of 1,2-butadiene was added to 1,3-butadiene was almost the same as Sample A (Example 1) in which 200 ppm was added, although the amount of visible gel was small. The Mooney viscosity was lowered despite the solution viscosity, suggesting that the degree of branching was reduced.
From the above, it was confirmed that the branched polymer mainly composed of polybutadiene of this example was substantially free of gel and excellent in appearance.

ADVANTAGE OF THE INVENTION According to this invention, the continuous manufacturing method of the branched butadiene type polymer with which generation | occurrence | production of gel was reduced can be provided. Furthermore, it is possible to provide a continuous production method of a branched butadiene-based polymer having a broad molecular weight distribution, which does not contain a halogen compound, has reduced gel generation, and has excellent appearance.
Therefore, the present invention is useful in the field of rubber for modifying styrenic resins such as high impact polystyrene (HIPS), mass ABS, and transparent MBS resin.

Claims (13)

1,3-butadiene or 1,3-butadiene and an aromatic vinyl compound and an inert solvent are continuously supplied to a polymerization reactor at a supply temperature of 30 ° C. or lower, and polymerization is continuously performed using an organolithium compound as an initiator. And a polymerization step for obtaining an active terminal-containing linear butadiene-based polymer,
A coupling step in which the active terminal-containing linear butadiene-based polymer is continuously supplied to a coupling reactor, and a coupling agent represented by the following formula (1) is continuously added to continuously perform a coupling reaction; ,
A method for producing a branched butadiene-based polymer.

(In the formula (1), each R independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms. N is an integer of 0 or 1.) The branched butadiene-based polymer has a Mooney viscosity (ML _{1 + 4} ) at a measurement temperature of 100 ° C. of 25 ≦ ML _{1 + 4} ≦ 55, and a 5 wt% styrene solution viscosity (SV) measured at 25 ° C. of 25 ≦ SV ≦ 50. The branched butadiene-based polymer according to claim 1, which is a branched butadiene-based polymer having a molecular weight distribution (Mw / Mn) measured by GPC of 1.5 to 2.5. A method for producing a polymer.   The method for producing a branched butadiene-based polymer according to claim 1 or 2, wherein the allene compound is continuously supplied to the polymerization reactor at a ratio of 50 to 350 ppm with respect to 1,3-butadiene.   The manufacturing method of the branched butadiene-type polymer of any one of Claims 1-3 whose coupling agent in the said coupling process is tetramethoxysilane or tetraethoxysilane.   The branched butadiene-based polymer according to any one of claims 1 to 4, wherein at least one of the polymerization reactors and at least one of the coupling reactors are fully mixed reactors. Manufacturing method.   The method for producing a branched butadiene-based polymer according to any one of claims 1 to 5, wherein a temperature at the top of the polymerization reactor is 120 ° C or lower.   The method for producing a branched butadiene polymer according to any one of claims 1 to 6, wherein the branched butadiene polymer is a branched polybutadiene.   The method for producing a branched butadiene polymer according to any one of claims 1 to 6, wherein the branched butadiene polymer is a branched butadiene-styrene copolymer. A coupling agent represented by the following formula (1) is an active terminal-containing linear butadiene polymer obtained by polymerizing 1,3-butadiene or 1,3-butadiene and an aromatic vinyl compound in the presence of an inert solvent. A branched butadiene-based polymer obtained by a coupling reaction using

(In the formula (1), each R independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms. N is an integer of 0 or 1.)
The supply temperature of 1,3-butadiene or 1,3-butadiene and an aromatic vinyl compound and an inert solvent to the polymerization reactor during the polymerization is 30 ° C. or less, and the Mooney viscosity (ML _{1 + 4 at} a measurement temperature of 100 ° C. ) Is 25 ≦ ML _{1 + 4} ≦ 55, 5 wt% styrene solution viscosity (SV) measured at 25 ° C. is 25 ≦ SV ≦ 50 (mPa · s), and molecular weight distribution (Mw / A branched butadiene-based polymer having a Mn) of 1.5 to 2.5. A coupling agent represented by the following formula (1) is an active terminal-containing linear butadiene polymer obtained by polymerizing 1,3-butadiene or 1,3-butadiene and an aromatic vinyl compound in the presence of an inert solvent. A branched butadiene-based polymer obtained by a coupling reaction using

(In formula (1), each R independently represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 1 to 10 carbon atoms. N is an integer of 0 or 1.)
The Mooney viscosity (ML _{1 + 4} ) at a measurement temperature of 100 ° C. is 25 ≦ ML _{1 + 4} ≦ 55, the 5 wt% styrene solution viscosity (SV) measured at 25 ° C. is 25 ≦ SV ≦ 50 (mPa · s), and A branched butadiene-based polymer having a molecular weight distribution (Mw / Mn) measured by GPC of 1.5 to 2.5 and 5 or less visible gels:
Here, the visible gel was prepared by dissolving 5 g of a branched butadiene-based polymer in 200 ml of toluene, suction filtering with filter paper, and then adding 0.4 g of C.I. I. This refers to the number of gels observed by observing the filter paper on which toluene was evaporated after dropping several drops of a dye solution obtained by dissolving Solvent Violet 36 in 800 ml of toluene and coloring the whole.   The branched butadiene-based polymer according to claim 9 or 10 obtained by the production method according to any one of claims 1 to 8.   12 to 100 parts by mass of the branched butadiene polymer according to any one of claims 9 to 11, 0.01 to 2.0 parts by mass of at least one of a phenol stabilizer and a phosphorus stabilizer, and A branched butadiene-based polymer composition containing 0.01 to 2.0 parts by mass of a sulfur-containing phenol-based compound.   The branched butadiene-type polymer composition which contains 0.01-0.5 mass part of organic fatty acids with respect to 100 mass parts of branched butadiene-type polymers of any one of Claims 9-11.