JP6480758B2 - Process for producing conjugated diene polymer - Google Patents

Description

  The present invention relates to a method for producing a conjugated diene polymer.

  A polymer (conjugated diene polymer) obtained by solution polymerization of a conjugated diene monomer is generally brought into contact with a mixture of a conjugated diene polymer obtained after solution polymerization and a solvent and a large amount of steam. The solvent is evaporated (devolatilized). There is also a method in which the solvent in the mixture is devolatilized without bringing steam into direct contact with the mixture of the conjugated diene polymer and the solvent. For example, using a device having a screw such as a twin screw extruder and a kneader, a method of heating the mixture while conveying the mixture with the screw and devolatilizing the solvent has been proposed (see, for example, Patent Document 1). Furthermore, Patent Document 2 proposes a method in which a polymer returning means is installed in the vent portion and the flying polymer is pushed back into the screw.

JP 2011-1116025 A JP 2003-251626 A

  However, in the method of contacting with a large amount of steam, a large amount of steam is consumed, so that a large amount of energy is required, and the moisture remaining in the conjugated diene polymer after devolatilization is removed to remove the moisture. In other words, there are many processes required for the process, and the energy consumption in the process is high, and the final product of the conjugated diene polymer is condensed in the container during transportation.

  Further, in the method described in Patent Document 1, since a fine polymer of a conjugated diene polymer adheres to and accumulates on a vent portion of a biaxial apparatus, the vent can be operated by operating the apparatus for a long period of time. Is blocked. When the vent is blocked, the operation of the apparatus is stopped, and a great deal of labor and time is taken to remove the deposits, resulting in a reduction in production efficiency. Further, in the method described in Patent Document 2, in the case of a conjugated diene polymer having strong adhesiveness, not a little deposit is accumulated in the polymer returning means, and the deposit is deteriorated and deteriorated due to the thermal history. Deteriorated deposits may fall into the screw, causing the molecular weight of the finally obtained conjugated diene polymer to decrease, and causing contamination of the conjugated diene polymer. , There is a concern of causing quality degradation.

  Then, this invention suppresses adhesion of the conjugated diene polymer with respect to the guide part with which the apparatus which has a screw is provided, and the manufacturing method of the conjugated diene polymer which can suppress the thermal deterioration of the attached conjugated diene polymer. The purpose is to provide.

  As a result of intensive studies to solve the above-described problems of the prior art, the present inventors have used a production process for producing a mixture containing a conjugated diene polymer and a solvent, and an apparatus having a biaxial screw. And a devolatilization step for devolatilizing the solvent, and using the method for producing a conjugated diene polymer, in which the apparatus is provided with a specific guide part, adhesion of the conjugated diene polymer to the guide part provided in the apparatus It was found that the thermal degradation of the attached conjugated diene polymer can be suppressed while suppressing the above, and has led to the present invention.

That is, the present invention is as follows.
[1]
A production process for producing a mixture comprising a conjugated diene polymer and a solvent;
Using a device having a biaxial screw, devolatilizing the solvent, and
The apparatus has one or more vent ports for exhausting the gas component of the devolatilized solvent to the outside of the apparatus,
A guide part is provided between the inner wall surface of the device having the biaxial screw and the inner wall surface of the device on the side where the vent port is disposed, and the biaxial screw.
The thermal conductivity at 100 ° C. of the surface of the guide part is less than 50 W / m · K.
A method for producing a conjugated diene polymer.
[2]
The heat conductivity at 100 ° C. of the guide part is less than 50 W / m · K, [1]
A process for producing a conjugated diene polymer as described in 1. above.
[3]
The guide part includes a non-metallic material,
The method for producing a conjugated diene polymer according to [1] or [2], wherein the nonmetallic material has a thermal conductivity at 100 ° C. of less than 50 W / m · K.
[4]
The heat conductivity at 100 ° C. of the surface of the guide part is less than 15 W / m · K.
[1] A method for producing a conjugated diene polymer according to any one of [3].

  According to the production method of the present invention, it is possible to suppress adhesion of the conjugated diene polymer to a guide part provided in an apparatus having a screw and to suppress thermal deterioration of the attached conjugated diene polymer.

It is a longitudinal cross-sectional view which shows typically an example of the apparatus which has a biaxial screw which concerns on this embodiment. It is a cross-sectional view which shows typically an example of the apparatus which has a biaxial screw which concerns on this embodiment.

  Hereinafter, a mode for carrying out the present invention (hereinafter 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 various modifications within the scope of the gist.

[Method for producing conjugated diene polymer]
The method for producing a conjugated diene polymer according to this embodiment includes a production process for producing a mixture containing a conjugated diene polymer and a solvent, and a devolatilization process for devolatilizing the solvent using an apparatus having a biaxial screw. And having. The apparatus includes a guide part, and the thermal conductivity at 100 ° C. of the surface of the guide part is less than 50 W / m · K.

〔Manufacturing process〕
The production process of the present embodiment is not limited to the following as long as it can produce a conjugated diene polymer solution containing a conjugated diene polymer and a solvent. For example, a single amount that is a raw material for the conjugated diene polymer Examples thereof include a method of dissolving a polymer (hereinafter referred to as “conjugated diene monomer”) in a solvent and polymerizing by solution polymerization, and a known method.

  The mixture of the present embodiment refers to a mixture containing at least a conjugated diene polymer and a solvent. For example, a mixture in which a conjugated diene polymer is present in a solvent remaining as a result of polymerizing a conjugated diene monomer by solution polymerization may be mentioned. Here, the conjugated diene polymer in the mixture does not need to be completely dissolved in the solvent, but is completely dissolved, partially dissolved, or not dissolved in the solvent. The thing of the state which is doing is included. Moreover, the conjugated diene monomer may be contained in the mixture.

<Conjugated diene polymer>
The conjugated diene polymer of the present embodiment may be a polymer obtained by polymerizing a conjugated diene monomer, and may be a homopolymer or a copolymer. The conjugated diene monomer is not particularly limited as long as it is a polymerizable monomer. For example, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, Examples include 3-methyl-1,3-pentadiene, 1,3-heptadiene, and 1,3-hexadiene. Among these, 1,3-butadiene and isoprene are preferable from the viewpoint of industrial availability. These may be used alone or in combination of two or more.

  If the conjugated diene monomer contains allenes, acetylenes or the like as impurities, there is a risk of inhibiting the terminal modification reaction of the conjugated diene polymer after polymerization. Therefore, the total content of these impurities is preferably 200 ppm by mass or less, more preferably 100 ppm by mass or less, and 50 ppm by mass or less with respect to the total amount of the conjugated diene monomer. Is more preferable. Examples of the allenes include propadiene and 1,2-butadiene, and examples of the acetylenes include ethylacetylene and vinylacetylene.

  The conjugated diene polymer of this embodiment may be a copolymer of the conjugated diene monomer and the aromatic vinyl monomer listed above. The aromatic vinyl monomer is not limited to the following as long as it is a monomer copolymerizable with the conjugated diene monomer. For example, styrene, m or p-methylstyrene, α-methylstyrene, vinylethylbenzene Vinyl xylene, vinyl naphthalene, diphenylethylene, and divinylbenzene. Among these, styrene is preferable from the viewpoint of industrial availability. These may be used alone or in combination of two or more.

  When the conjugated diene polymer is a copolymer of a conjugated diene monomer and an aromatic vinyl monomer, the aromatic vinyl monomer unit in the conjugated diene polymer is The content is preferably 3% by mass or more and 97% by mass or less, and more preferably 5% by mass or more and 95% by mass or less with respect to 100% by mass of the coalescence. The content of the aromatic vinyl monomer unit is measured according to the conjugated diene monomer and the aromatic vinyl monomer to be used according to the method for measuring the amount of bound styrene described in the examples described later.

  From the viewpoint of quality control, the content of 1,2-bonds and 3,4-bonds (vinyl bond amount) is 5% by mass or more and 95% by mass or less with respect to the total amount of the coupling mode of the conjugated diene polymer. It is preferably 10% by mass or more and 90% by mass or less. The amount of vinyl bonds is measured by the method described in the examples described later.

  When the conjugated diene polymer is a copolymer, the conjugated diene polymer may be a random copolymer or a block copolymer.

  Examples of the random copolymer include, but are not limited to, for example, butadiene-isoprene random copolymer, butadiene-styrene random copolymer, isoprene-styrene random copolymer, butadiene-isoprene-styrene random copolymer. Is mentioned. The composition distribution of each monomer in these copolymer chains is not limited to the following, for example, a completely random copolymer close to a statistical random composition, a taper with a gradient in the composition distribution (gradient) ) Random copolymers. The bonding mode of the conjugated diene polymer, that is, the composition of 1,4-bond, 1,2-bond, etc. may be uniform or different depending on the molecular chain.

  The block copolymer is not limited to the following, for example, a 2-type block copolymer consisting of 2 blocks, a 3-type block copolymer consisting of 3 blocks, and a 4-type block copolymer consisting of 4 blocks. Coalesce is mentioned. Here, a block composed of an aromatic vinyl monomer such as styrene is represented by S, and a block composed of a conjugated diene monomer such as butadiene or isoprene and / or a co-weight of the aromatic vinyl monomer and the conjugated diene compound. When a block composed of a combination is represented by B, it is represented by an S—B2 type block copolymer, an S—B—S3 type block copolymer, a S—B—S—B4 type block copolymer or the like.

  In the above equation, the boundaries of each block need not be clearly distinguished. For example, when the block B is a copolymer of an aromatic vinyl monomer and a conjugated diene monomer, the aromatic vinyl compound in the block B is distributed uniformly or in a tapered shape. Also good. 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 monomer 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.

  From the viewpoint of quality control, the weight average molecular weight (Mw) of the conjugated diene polymer is preferably from 50,000 to 2,000,000, more preferably from 100,000 to 1,800,000, and the molecular weight of the conjugated diene polymer. The distribution (weight average molecular weight relative to number average molecular weight (Mn), Mw / Mn) is preferably 1.0 or more and 3.0 or less, and more preferably 1.5 or more and 2.5 or less. A weight average molecular weight and molecular weight distribution are measured by the method as described in the Example mentioned later.

  From the viewpoint of quality control, the Mooney viscosity of the conjugated diene polymer is preferably 20 or more and 150 or less, and more preferably 30 or more and 130 or less. The Mooney viscosity is measured by the method described in Examples described later.

  Although it will not specifically limit as a polymerization initiator of this embodiment if it is an initiator which polymerizes a conjugated diene monomer, It is preferable that it is an anionic polymerization initiator. Among the anionic polymerization initiators, an alkyl compound of a metal such as aluminum, magnesium, lithium, sodium, and potassium is more preferable from the viewpoint of stability and handleability, and among these, from the viewpoint of polymerization efficiency, organic lithium is more preferable. preferable. Examples of the organic lithium used as the polymerization initiator include low molecular weight compounds or solubilized oligomeric organic lithium. In addition, examples of the organic lithium classified according to the bonding mode between the organic group of the organic lithium and lithium include organic lithium composed of a carbon-lithium bond and organic lithium composed of a nitrogen-lithium bond.

  Examples of the organic lithium having a carbon-lithium bond include, but are not limited to, for example, n-butyllithium, sec-butyllithium, tert-butyllithium, n-hexyllithium, benzyllithium, phenyllithium, and stilbenelithium. Can be mentioned.

  The organic lithium composed of a nitrogen-lithium bond is not limited to the following, 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, and lithium morpholide.

  Examples of organolithium include not only monoorganolithium having a monofunctional group described above but also polyfunctional organolithium having a polyfunctional group. Monoorganolithium and polyfunctional organolithium may be used alone or in combination of two or more.

  Examples of the polyfunctional organolithium include, but are not limited to, for example, 1,4-dilithiobutane, a reaction product of sec-butyllithium and diisopropenylbenzene, 1,3,5-trilithiobenzene, n-butyl. Examples include a reaction product of lithium, 1,3-butadiene and divinylbenzene, and a reaction product of n-butyllithium and a polyacetylene compound. Further, organic lithium disclosed in US Pat. No. 5,708,092, British Patent 2,241,239, US Pat. No. 5,527,753, and the like can also be mentioned.

  Among the above-described organic lithiums, n-butyllithium and sec-butyllithium are more preferable from the viewpoint of industrial availability and ease of control of the polymerization reaction. These organolithiums may be used as a mixture of not only one type but also two or more types.

  When organolithium is used for polymerization, it is preferable to use a solution diluted with a hydrocarbon solvent in order to improve the handleability and dispersibility in the polymerization solution. Examples of the hydrocarbon solvent include C4 to C8 hydrocarbon solvents, toluene, and xylene. The hydrocarbon solvent may be cyclic and may contain an unsaturated bond or a branched structure. Since the boiling point or vapor pressure of the hydrocarbon solvent is easy to handle in the production process, C5 and C6 hydrocarbon solvents are more preferable, and specifically, pentane, normal hexane, and cyclohexane are more preferable.

  The concentration when the organic lithium is diluted in the hydrocarbon solvent is preferably in the range of 0.01% by mass or more and 1.0% by mass or less from the viewpoint of the polymerization initiation efficiency and the uniform mixing property with the monomer. Preferably they are 0.1 mass% or more and 0.8 mass% or less.

  The polymerization reaction of the conjugated diene compound is preferably a solution polymerization reaction in which polymerization is performed in a solvent (hereinafter also referred to as “polymerization reaction solvent”). The solvent for the polymerization reaction is not limited to the following, but examples thereof include hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. Examples of hydrocarbon solvents include aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane, and methylcyclohexane; aromatics such as benzene, toluene, and xylene. Hydrocarbons; hydrocarbons composed of mixtures thereof.

  Treatment of allenes and acetylenes, which are impurities, with an organometallic compound before being subjected to a polymerization reaction tends to yield a polymer having a high concentration of active terminals. It is preferable because a high modification rate tends to be achieved.

  In the production process, a polar compound may be added. The polar compound can also be used for randomly copolymerizing an aromatic vinyl compound with a conjugated diene compound, and can also be used as a vinylating agent for controlling the microstructure of the conjugated diene part. It is also effective in improving the polymerization rate.

  Examples of polar compounds include, but are not limited to, 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). ) Ethers such as propane; Tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, trimethylamine, triethylamine, pyridine, quinuclidine; potassium-t-amylate, potassium-t-butylate, sodium-t-butylate, Examples include alkali metal alkoxide compounds such as sodium amylate; and phosphine compounds such as triphenylphosphine. 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, Although it can select according to the objective etc., it is preferable that they are 0.01 mol or more and 100 mol or less 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 vinyl bond amount as a microstructure regulator of the conjugated diene moiety of the conjugated diene polymer.

  Many polar compounds have an effective randomizing effect in the copolymerization of conjugated diene compounds and aromatic vinyl compounds, and can also be used as regulators of aromatic vinyl compound distribution and styrene block content. . As a method for randomizing the conjugated diene compound and the aromatic vinyl compound, for example, as described in JP-A-59-140221, a part of 1,3-butadiene is intermittently interrupted during the copolymerization. The method of adding automatically is mentioned.

  The polymerization temperature is not particularly limited as long as the polymerization proceeds, but is preferably 0 ° C. or higher from the viewpoint of productivity, and 120 ° C. or lower from the viewpoint of suppressing deactivation during the polymerization. preferable. In the production process, from the viewpoint of preventing cold flow of the conjugated diene polymer, a polyfunctional aromatic vinyl compound such as divinylbenzene for controlling branching may be used.

  From the viewpoint of vulcanized physical properties, the conjugated diene polymer of the present embodiment is preferably a compound having a functional group of glycidyl group or alkoxysilyl group and modified. After obtaining the conjugated diene polymer by the method as described above, the conjugated diene polymer can be further modified by reacting a compound having a glycidyl group or an alkoxysilyl group with the active terminal of the conjugated diene polymer. it can.

  The compound having a glycidyl group is not limited to the following compounds, but includes, for example, two polyglycidyl ethers of polyhydric alcohols such as ethylene glycol diglycidyl ether and glycerin triglycidyl ether; 4,4′-diglycidyl-bisphenol A and the like. Polyglycidyl ethers of aromatic compounds having the above phenol groups; polyepoxy compounds such as 1,4-diglycidylbenzene, 1,3,5-triglycidylbenzene, polyepoxidized liquid polybutadiene; 4,4′-diglycidyl- Epoxy group-containing tertiary amines such as diphenylmethylamine and 4,4′-diglycidyl-dibenzylmethylamine; diglycidylaniline, diglycidylorthotoluidine, tetraglycidylmetaxylenediamine, tetraglycidylaminodiphenyl Tan, tetraglycidyl -p- phenylenediamine, diglycidyl aminomethyl cyclohexane, diglycidyl amino compounds such as tetraglycidyl-1,3-bis-aminomethyl cyclohexane.

Among the compounds having a glycidyl group, polyfunctional compounds having two or more glycidyl groups and one or more nitrogen-containing groups in the molecule are preferred. From the viewpoint of vulcanized physical properties, a polyfunctional compound represented by the following general formula (1) is more preferable.
In formula (1), R ¹ and R ² each independently represents an alkyl group having 1 to 10 carbon atoms, or an alkyl group having 1 to 10 carbon atoms having an ether group and / or a tertiary amine group. , R ³ and R ⁴ each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms having an ether group and / or a tertiary amine group; ⁵ is an alkyl group having 1 to 20 carbon atoms, or an ether group, a tertiary amine group, an epoxy group, a carbonyl group, and at least one functional group selected from the group consisting of halogen atoms and having 1 to 20 carbon atoms. Represents an alkyl group, and n represents an integer of 1 to 6. When n is an integer of 2 or more, R ^{1 to} R ^{4 when} there are a plurality of R ^{1 to} R ⁴ are independent from each other.

  The polyfunctional compound represented by the formula (1) is not limited to the following, but examples thereof include tetraglycidyl-p-phenylenediamine, diglycidylaminomethylcyclohexane, tetraglycidyl-1,3-bisaminomethylcyclohexane. Can be mentioned. The polyfunctional compound is more preferably a polyfunctional compound having a diglycidylamino group. Further, the polyfunctional compound has two or more epoxy groups in the molecule, preferably three or more, and more preferably four or more.

  The compound having an alkoxysilyl group is not limited to the following compounds, but examples thereof include dimethoxydimethylsilane, xyldimethylsilane, diethoxydiethylsilane, triphenoxyvinylsilane, trimethoxyvinylsilane, triethoxyvinylsilane, and tri (2-methylbutoxy). Ethylsilane, tri (2-methylbutoxy) vinylsilane, triphenoxyphenylsilane, tetraphenoxysilane, tetraethoxysilane, tetramethoxysilane, tetrakis (2-ethylhexyloxy) silane, phenoxydivinylchlorosilane, methoxydiethylchlorosilane, diphenoxymethylchlorosilane, Diphenoxyphenyliodosilane, diethoxymethylchlorosilane, dimethoxyethylchlorosilane, triethoxychlorosilane, Liphenoxychlorosilane, tris (2-ethylhexyloxy) chlorosilane, phenoxymethyldichlorosilane, methoxyethyldichlorosilane, ethoxymethyldichlorosilane, phenoxyphenyldiiodosilane, phenoxydichlorosilane, dimethoxydichlorosilane, bis (2-methylbutoxy) dibromo Examples include silane.

Among the compounds having an alkoxysilyl group, a compound represented by the following general formula (2) having an N atom and a plurality of alkoxysilyl groups in the molecule is preferable from the viewpoint of vulcanization properties.
In formula (2), R ¹ and R ² each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R ³ and R ⁴ are each independently Represents an alkyl group having 1 to 20 carbon atoms, R ⁵ represents an alkyl group having 1 to 6 carbon atoms, and has a ring structure of five or more members with an adjacent nitrogen atom and silicon atom, and R ⁶ represents a carbon number 1 to 20 alkyl group, an alkyl group having 1 to 20 carbon atoms which does not have an active hydrogen atom and is substituted with a hetero atom, or an organic substituted silyl group, m represents an integer of 1 or 2, n Represents an integer of 2 or 3. R ¹ to R ⁴ in the case of the the m and n R ¹ to R ⁴ is present in plural may each be the same or different.

  The compound represented by the formula (2) is not limited to the following compounds. For example, 2,2-dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane, 2 , 2-Diethoxy-1- (3-triethoxysilylpropyl) -1-aza-2-silacyclopentane, 2,2-dimethoxy-1- (4-trimethoxysilylbutyl) -1-aza-2-sila Cyclohexane, 2,2-dimethoxy-1- (5-trimethoxysilylpentyl) -1-aza-2-silacycloheptane, 2,2-dimethoxy-1- (3-dimethoxymethylsilylpropyl) -1-aza- 2-silacyclopentane, 2,2-diethoxy-1- (3-diethoxyethylsilylpropyl) -1-aza-2-silacyclopentane, 2-methoxy, 2-methyl- -(3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane, 2-ethoxy, 2-ethyl-1- (3-triethoxysilylpropyl) -1-aza-2-silacyclopentane, 2 -Methoxy, 2-methyl-1- (3-dimethoxymethylsilylpropyl) -1-aza-2-silacyclopentane, 2-ethoxy, 2-ethyl-1- (3-diethoxyethylsilylpropyl) -1- Aza-2-silacyclopentane. Among these compounds, those in which m is 2 and n is 3 are preferable from the viewpoints of reactivity and interaction between the functional group of the compound and an inorganic filler such as silica, and processability. Specifically, 2,2-dimethoxy-1- (3-trimethoxysilylpropyl) -1-aza-2-silacyclopentane, 2,2-diethoxy-1- (3-triethoxysilylpropyl) -1 -Aza-2-silacyclopentane is more preferred.

  After the polymerization, a deactivator, a neutralizing agent, etc. may be added to the reaction solution as necessary. Examples of the quenching agent include, but are not limited to, water; alcohols such as methanol, ethanol, and isopropanol. Examples of the neutralizing agent include, but are not limited to, carboxylic acids such as stearic acid, oleic acid, and versatic acid; aqueous solutions of inorganic acids, and carbon dioxide.

  From the viewpoint of further suppressing gel formation after polymerization and improving the stability during processing, it is preferable to add a stabilizer for rubber to the obtained conjugated diene polymer. The rubber stabilizer is not limited to the following, and known ones can be used. For example, 2,6-di-tert-butyl-4-hydroxytoluene (BHT), n-octadecyl-3- Antioxidants of (4′-hydroxy-3 ′, 5′-di-tert-butylphenol) propinate and 2-methyl-4,6-bis [(octylthio) methyl] phenol are preferred.

  The mixture of the conjugated diene polymer and the solvent preferably contains oil. Examples of the oil include, but are not limited to, aromatic, naphthenic, paraffinic oil, MES (Mil Extracted Solvates), T-DAE (Treated-Distilled Aromatic Extracts), and among these, An oil having a high boiling point of 250 ° C. or higher is more preferable. These oils remain together with the conjugated diene polymer without being devolatilized even when the solvent is devolatilized from the mixture of the conjugated diene polymer and the solvent in the devolatilization step described later. The remaining oil has an effect of improving processability when the conjugated diene polymer is mixed and processed with other materials. These oils are generally called rubber extension oils.

  The blending amount when blending the oil is preferably 5 parts by mass or more and 100 parts by mass or less, more preferably 10 parts by mass or more and 50 parts by mass or less, with respect to 100 parts by mass of the conjugated diene polymer. More preferably, they are 15 to 40 mass parts. When the blending amount is 5 parts by mass or more, the workability improving effect tends to be expressed. When the blending amount is 100 parts by mass or less, the mechanical properties of the conjugated diene polymer vulcanizate tend to be excellent. .

  From the viewpoint of quality control, the Mooney viscosity of the conjugated diene polymer containing the oil after the devolatilization step is preferably 20 or more and 120 or less, and more preferably 30 or more and 100 or less.

  The mixture of the conjugated diene polymer and the solvent of this embodiment is produced, for example, as a result of polymerizing a conjugated diene monomer in a polymerization reaction solvent as described above. Further, the mixture of the conjugated diene polymer and the solvent may be subjected to a step of devolatilizing the solvent by another method other than the devolatilization step described later, for example, concentrated using a means such as flash drying after the polymerization. It may be devolatilized using a thing.

<Solvent>
Therefore, the solvent of the present embodiment is not limited to the above-described polymerization reaction solvent, but examples thereof include the same solvents as the polymerization reaction solvent. Examples thereof include hydrocarbon solvents such as saturated hydrocarbons and aromatic hydrocarbons. Specifically, aliphatic hydrocarbons such as butane, pentane, hexane and heptane; alicyclic hydrocarbons such as cyclopentane, cyclohexane, methylcyclopentane and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene; A hydrocarbon composed of a mixture of these may be mentioned.

  In the mixture of conjugated diene polymer and solvent, solvent for diluting initiator, polar compound added in polymerization process, quencher added at the end of polymerization, neutralizing agent, rubber stabilizer, antioxidant An agent may further be included. In addition to these, the mixture of the conjugated diene polymer and the solvent may be adjusted by mixing the conjugated diene polymer with a solvent capable of dissolving. Further, in the mixture of the conjugated diene polymer and the solvent, the conjugated diene polymer may be dissolved in the solvent or separated.

  The solvent composition in the mixture of the conjugated diene polymer and the solvent is preferably 1.0% by mass or more and 99% by mass or less, more preferably 30% by mass or more and 93% by mass or less, and more preferably 50% by mass or more. More preferably, it is 90 mass% or less. The concentration of the conjugated diene polymer in the mixture of the conjugated diene polymer and the solvent is preferably 5.0% by mass or more and 95% by mass or less from the viewpoint of fluidity of the mixture, and is 7.0% by mass. It is more preferably 50% by mass or less, and further preferably 10% by mass or more and 30% by mass or less.

  The viscosity of the mixture of the conjugated diene polymer and the solvent is not particularly limited, but from the viewpoint of handling at the time of supply, it is 0.01 Pa · s or more and 100,000 Pa.s. s or less, and from the viewpoint of screw transportability, 10 Pa · s or more and 10,000 Pa.s. More preferably, it is s or less.

[Volatilization process]
The devolatilization step of this embodiment is a step of devolatilizing the solvent of the mixture of the conjugated diene polymer obtained in the production process and the solvent using an apparatus having a biaxial screw. Here, it is preferable to isolate the conjugated diene polymer by rotating the biaxial screw of the device and heating the biaxial screw while conveying the mixture, thereby evaporating the solvent.

  The step of devolatilizing the solvent may be only the devolatilization step, or may include a step of devolatilizing the solvent by another method before the manufacturing step and after the devolatilization step. In addition, after the production process and before the devolatilization process, after performing a process of devolatilizing the solvent by another method other than the devolatilization process, the solvent is further devolatilized in the devolatilization process, and the conjugated diene polymer is obtained. It may be isolated.

<Apparatus with screw>
The apparatus having a screw according to the present embodiment is not particularly limited as long as it is an apparatus having a biaxial screw, but an apparatus having a rotating biaxial screw is preferable. The apparatus having a rotating biaxial screw is not particularly limited as long as it has an extruder type, a kneader type, or a similar structure used for resin kneading. The shape of the screw may be appropriately selected from a seal ring, a disk, a rotor, a retrograde flight, etc. in addition to a normal flight screw, and may be combined as necessary. Further, the screws may or may not mesh with each other with the shaft cores parallel to each other.

  From the viewpoint of the residual solvent composition of the devolatilized conjugated diene polymer, it is preferable to use two or more apparatuses having a rotating biaxial screw in the devolatilization step. When rotating a plurality of screws, the rotation direction may be the same direction or the reverse direction, and the rotation speeds may be the same or different. However, from the viewpoint of suppressing the conjugated diene polymer from adhering to the screw, the rotation direction is preferably different and the rotation speed is preferably different.

  A device having a biaxial screw can heat a mixture of a conjugated diene polymer and a solvent by circulating a heat medium such as high-temperature steam or oil through a jacket provided in the device. The temperature of the heat medium at this time is preferably 50 ° C. or higher and 300 ° C. or lower from the viewpoint of devolatilization speed, and is 100 ° C. or higher and 200 ° C. or lower from the viewpoint of the transportability of the mixture and gel suppression. Is more preferable. These ranges are also preferable for the temperature of the conjugated diene polymer to be devolatilized. However, the temperature of the conjugated diene polymer may be lower than the temperature of the heat medium due to vaporization heat consumption accompanying the devolatilization of the solvent.

  A device having a biaxial screw has one or more vent ports for exhausting the gas component of the devolatilized solvent out of the device. The devolatilized gas is discharged from the vent port, and then cooled and condensed by a cooler or the like, and may be recovered and reused as a liquid. If the conjugated diene polymer adheres to the vent port, the exhaust amount may decrease. Therefore, in addition to the guide parts described later, a device for removing the deposit on the vent port may be attached. Examples of the apparatus include a scraper and a rotary blade that rotate along the inner wall surface of the vent port. The device for removing the deposits on the vent port is a device for forcibly peeling the deposits on the vent port, and the guide parts used in this embodiment prevent the material from flying to the vent port. Therefore, both have completely different effects.

  When using the device of this embodiment or the device of a different mechanism before or after the device having a biaxial screw or continuously with the device, two or more devices are connected in series, and the conjugated diene polymer and Although the method of sending the mixture with a solvent continuously and the method of processing batchwise with each apparatus are mentioned, the method of sending continuously is more preferable from the viewpoint of production efficiency. Examples of the device for continuously feeding the mixture of the conjugated diene polymer and the solvent include a pump such as a gear pump, a screw type device such as a twin screw extruder, and a conveyor. In a method in which two or more apparatuses are connected and continuously devolatilized, conditions for devolatilization such as temperature and pressure may be different for each apparatus.

  In general, an apparatus having a screw is preferably an apparatus having a wide heat transfer area because the heating rate is a rate-determining rate of devolatilization treatment in the initial stage of concentration. Therefore, it is also preferable to make the screw surface into a heat transfer section by making the inside of the screw hollow and passing the heat medium therethrough. As the concentration progresses, solids may precipitate. In that case, in order to devolatilize the solvent contained in the solid material, a function of applying shear to the solid material and renewing the surface is required.

  The pressure in the gas phase when the solvent is devolatilized is preferably not more than normal pressure from the viewpoint of devolatilization speed, but the devolatilization speed and conjugated diene polymer are prevented from being accompanied by solvent gas. Therefore, it is more preferable that it is 50 to 700 torr.

  The apparatus having a biaxial screw according to this embodiment includes guide parts. Further, the thermal conductivity at 100 ° C. of the surface of the guide baht is less than 50 W / m · K. Adhesion is strong by devolatilizing the solvent in the above-mentioned mixture using an apparatus having a biaxial screw including guide parts having a thermal conductivity at 100 ° C. of less than 50 W / m · K. Even in the conjugated diene polymer, accumulation of deposits in the apparatus can be suppressed, and deterioration of the conjugated diene polymer due to thermal history can also be suppressed.

  Hereinafter, although the apparatus which has a biaxial screw provided with a guide part using a drawing is demonstrated concretely, these are not restricted to the following.

  FIG. 1 is a longitudinal sectional view schematically showing an example of a device having a biaxial screw according to the present embodiment. FIG. 2 is a schematic view of an example of a device having a biaxial screw according to the present embodiment. FIG. The charging port 1 is a port into which the mixture manufactured in the manufacturing process is charged. The introduced mixture is conveyed and heated by the screw 7 to devolatilize the solvent in the devolatilization step, and is discharged from the outlet 8 as a conjugated diene polymer. The apparatus includes an apparatus outer wall surface 2 and an apparatus inner wall surface 3, and guide parts are provided for the apparatus inner wall surface 3. The guide part 6 is provided inside the apparatus in order to prevent a substance that flies along with the gas of the volatilized solvent from flying up to the vent port 5. The guide part 6 is installed in the evaporation chamber 4 of the apparatus. The guide parts are preferably installed in a direction parallel to the screws 7 in the evaporation chamber 4 of the apparatus. The guide parts 6 are installed at the boundary between all the screws 7 and the inner wall surface 3 of the apparatus, but may be installed at the boundary between some of the screws 7 and the inner wall surface 3 of the apparatus. Further, from the viewpoint of preventing the conjugated diene polymer from adhering to the inner wall surface 3 of the apparatus, when the cross section of the screw 7 is observed from the direction of rotation of the outer rotation direction, that is, the direction perpendicular to the screw 7, the screws 7 may be separated from each other. It is more preferable to install at the boundary between the screw 7 rotating in the direction of

  The evaporation chamber 4 is a space generated between the screw 7 inside the apparatus and the inner wall surface 3 of the apparatus. From the viewpoint of suppressing flying objects accompanying the volatile gas, the volume of the evaporation chamber 4 is preferably as large as possible. Since the size of the evaporation chamber 4 increases, it is preferable to set the volume of the evaporation chamber 4 according to the installation area of the apparatus.

  The shape of the guide part is not particularly limited, but is preferably a shape that can widely cover the boundary between the screw 7 and the inner wall surface 3 of the apparatus, more preferably a triangular column or a trapezoidal columnar body, and a cross section of 60 °. More preferably, the columnar body has an acute angle of less than. The size of the guide parts is not particularly limited, but can be freely designed according to the shape of the screw 7 and the inner wall surface 3 of the apparatus. The installation direction of the guide parts is not particularly limited, but when using a columnar body whose guide part has an acute angle in its cross-sectional shape, if the acute angle is installed so as to contact the boundary between the screw 7 and the inner wall surface 3 of the apparatus, Since there exists a tendency which can suppress accumulation | storage of the deposit | attachment in an apparatus efficiently, it is preferable.

  Since the thermal conductivity at 100 ° C. of the surface of the guide part is less than 50 W / m · K, the temperature of the part where the guide part and the deposit come into contact is lower than the inner wall surface of the device. Is updated efficiently. Moreover, since the guide parts have a lower temperature than the inner wall surface of the apparatus, it is possible to suppress thermal deterioration of the deposits. The heat conductivity of the surface of the guide part is less than 50 W / m · K, preferably less than 15 W / m · K, more preferably less than 1.0 W / m · K, and 0.1 W / m More preferably, it is less than m · K. The lower limit of the thermal conductivity of the surface of the guide part is not particularly limited, and may be below the detection limit. Further, when the guide part is made of a single material, the thermal conductivity of the surface of the guide part is the same as the thermal conductivity of the material of the guide part.

  The surface of the guide part refers to a portion having a thickness of 10 μm from the outer surface of the guide part. When the guide part is coated with an arbitrary material and the thickness of the material covered is 10 μm or more, the surface of the guide part means the entire material covered.

  When the heat conductivity at 100 ° C. of the surface of the guide part is less than 50 W / m · K, it is sufficient that at least the surface has a heat conductivity of less than 50 W / m · K. That is, the surface of the guide part and the other guide part part may be the same material, and the thermal conductivity of the entire guide part including the surface may be less than 50 W / m · K, or both may be different materials. Yes, the thermal conductivity of the entire guide part may be 50 W / m · K or more.

  From the viewpoint of guide part manufacturing cost, the heat conductivity at 100 ° C. of the guide part is preferably less than 50 W / m · K, more preferably less than 15 W / m · K, and 1.0 W / m · More preferably, it is less than K, and even more preferably less than 0.01 W / m · K. The lower limit of the thermal conductivity of the guide part is not particularly limited, and may be below the detection limit. In this specification, the thermal conductivity of a guide part refers to the thermal conductivity of the entire guide part including the surface.

  The material of the guide part and / or the guide part surface is not limited to the following as long as the thermal conductivity at 100 ° C. is less than 50 W / m · K. For example, metals such as cast iron, carbon steel, stainless steel, Nonmetals such as alumina ceramics, and resins such as Teflon (registered trademark) can be used. The material is preferably stainless steel having a thermal conductivity of less than 50 W / m · K at 100 ° C. (more preferably, 15 W / m · K to 30 W / m · K). From the viewpoint of the manufacturing cost of the guide parts, the material preferably includes a nonmetallic material having a thermal conductivity of less than 50 W / m · K, and more preferably includes a resin of less than 1.0 W / m · K.

  From the viewpoint of guide part manufacturing cost, the apparatus having a biaxial screw further includes a main member, and the difference between the thermal conductivity at 100 ° C. of the surface of the guide part and the thermal conductivity at 100 ° C. of the main member is 5.0 W / m · K or more, preferably 20 W / m · K or more, more preferably 40 W / m · K or more, and 200 W / m · K or more. Is even more preferable. The upper limit of the above difference is not particularly limited, and may be equal to or greater than the detection limit. In this specification, a main member is a member with the largest volume in the members which comprise the apparatus which has a biaxial screw. Various thermal conductivities at 100 ° C. are measured by the methods described in Examples described later.

  Examples of the main member include, but are not limited to, metal materials such as cast iron, carbon steel, and stainless steel, non-metallic materials such as alumina ceramics, and resins such as Teflon.

  A stripping agent may be added for the purpose of promoting the devolatilization of the solvent. Examples of the stripping agent include water, alcohol, and supercritical carbon dioxide gas.

  It is preferable that the mixture of the conjugated diene polymer and the solvent is heated before being supplied to a device having a biaxial screw because the devolatilization rate tends to be improved. The heating temperature is not particularly limited, but it is preferable to heat the solvent to the boiling point of the solvent at the pressure in the apparatus having a biaxial screw because the devolatilization rate tends to increase. For example, when the solvent in the mixture of the conjugated diene polymer and the solvent is hexane and the pressure in the apparatus having a twin screw is 400 torr, the boiling point of hexane at 400 torr is about 50 ° C., so the temperature of the mixture is 50 ° C. It is good to heat above.

  The mixture of the conjugated diene polymer and the solvent after the production process can be devolatilized by another apparatus having no biaxial screw before using the apparatus having the biaxial screw. Examples of another apparatus include a flash tank, a thin film type concentrator, a drum dryer, and a concentration vessel with a stirring blade.

  After devolatilizing the mixture of the conjugated diene polymer and the solvent, when leaving the device out of the device having a twin screw, the atmosphere of water or inert gas is used to prevent deterioration due to heat and atmospheric oxygen. It is preferable to be in an environment under or under reduced pressure.

  The residual volatile content in the conjugated diene polymer after the devolatilization step is preferably 10 mass ppm or more and 50,000 mass ppm or less from the viewpoint of workability when processing into a product. The residual volatile matter may contain water in addition to the raw materials such as the solvent used for the polymerization. The residual volatile matter is measured by the method described in the examples described later.

  The gel content in the conjugated diene polymer after the devolatilization step is preferably 5% by mass or less from the viewpoint of product performance and appearance. The gel content is measured by the method described in Examples described later.

  According to the manufacturing method of the present embodiment, it is possible to suppress adhesion of the conjugated diene polymer to the guide part provided in the device having a screw, and to suppress thermal deterioration of the attached conjugated diene polymer. In addition, due to the provision of such guide parts, adhesion and blockage of the conjugated diene polymer to the vent port of the device having a screw can be suppressed.

  The conjugated diene polymer is compression molded into a rectangular parallelepiped referred to in the industry as bale. The conjugated diene polymer is preferably blended with a rubber material such as natural rubber; an inorganic material such as silica or carbon, and processed into a tire, various industrial belts, footwear or the like.

  Hereinafter, the present embodiment will be described in more detail with specific examples and comparative examples. However, the present embodiment is not limited to the following examples and comparative examples as long as the gist of the present embodiment is not exceeded. Various physical properties in Production Examples, Examples, and Comparative Examples described later were measured by the following methods.

(Physical property 1) Amount of bound styrene A conjugated diene polymer sample was used as a chloroform solution, and the amount of bound styrene with respect to 100% by mass of the conjugated diene polymer was determined based on the amount of absorption at the ultraviolet absorption wavelength (near 254 nm) by the phenyl group of styrene (Mass%) was measured (trade name “UV-2450” manufactured by Shimadzu Corporation). Further, the combined amount of bound styrene was calculated by assuming that the combined amount of bound styrene and bound butadiene was 100% by mass.

(Physical property 2) Microstructure of butadiene part Using an infrared spectrophotometer (trade name “FT-IR230” manufactured by JASCO Corporation) with respect to a sample of a conjugated diene copolymer, a sample of 600 to 1000 cm ⁻¹ . Infrared spectra were measured in the range. The sample was a carbon disulfide solution and a solution cell was used. From the resulting absorbance, the microstructure of the butadiene portion, that is, the amount of vinyl bonds (mass%) was determined according to the formula of the Hampton method.

(Physical property 3) Mooney viscosity The sample of the conjugated diene copolymer was preheated at 100 ° C for 1 minute in accordance with JIS K6300-1: 2001, and the viscosity after 4 minutes was measured.

(Physical property 4) Molecular weight and molecular weight distribution The sample and the standard polystyrene chromatogram were measured using GPC which connected three columns which made the polystyrene-type gel the filler with respect to the sample of the conjugated diene polymer. (Guard column; trade name “TSKguardcummn HHR-H” manufactured by Tosoh Corporation, column; trade names “TSKgel G6000HHR”, “TSKgel G5000HHR”, “TSKgel G4000HHR” manufactured by Tosoh Corporation)). A calibration curve was created from the measurement results of standard polystyrene, thereby calculating the weight average molecular weight and molecular weight distribution. Tetrahydrofuran (THF) was used as the eluent. 10 mg of a sample was dissolved in 20 mL of THF, and this was injected into a 200 μL column and measured. The measurement was carried out under the conditions of an oven temperature of 40 ° C. and a THF flow rate of 1.0 mL / min, using a trade name “HLC8020” (detector; RI) manufactured by Tosoh Corporation.

(Physical property 5) Measurement of residual volatile content of polymer 1 g of the conjugated diene polymer obtained after the devolatilization step was placed under conditions of 180 ° C. and 50 torr for 3 hours. The weight loss (δ [g]) of the conjugated diene polymer by this operation was regarded as the residual volatile content, and the residual volatile content (mass%) was determined from the calculation formula of 100 × δ / (1-δ).

(Physical Property 6) Measurement of Gel Content 3 g of the conjugated diene polymer obtained after the devolatilization step was completely dissolved in 100 g of toluene and filtered through 100 mesh filter paper (α1 [g]). The filtered filter paper was dried and weighed (α2 [g]), and the gel content (mass%) was determined from the calculation formula of (100 × (α2-α1) / 3).

(Physical property 7) Thermal conductivity of guide part at 100 ° C. In accordance with ASTM D5470, a test piece made of the same material as the guide part is prepared, and the thermal resistance at 100 ° C. is measured with various test piece thicknesses. Conductivity was calculated.

(Production Example 1) Mixture of conjugated diene polymer and solvent (A)
Two 10 L reactors (4 ratios of reactor length (L) to reactor diameter (D) as L / D = 4) are arranged in series with four paddle stirring blades. A polymerization reactor and a second reactor were used as a modification reactor. Preliminary impurities such as moisture, 1,3-butadiene, 22.0 g / min, styrene, 7.1 g / min, n-hexane, 144 g / min. As before, after mixing with 0.10 mmol / min of n-butyllithium (treated n-butyllithium) with a static mixer immediately before entering the polymerization reactor, it is continuously fed to the bottom of the polymerization reactor, and further as a polar compound 2,2-bis (2-oxolanyl) propane was fed to the bottom of the polymerization reactor at a rate of 0.040 g / min and n-butyllithium as a polymerization initiator was fed at a rate of 0.210 mmol / min. The polymerization reaction was continued so that the internal temperature of the outlet was 90 ° C. The polymerization solution extruded from the first group was supplied to the modification reactor as it was. The temperature of the denaturing reactor was kept at 85 ° C., and tetraglycidyl-1,3-bisaminomethylcyclohexane as a denaturing agent was added at a rate of 0.42 mmol / min from the bottom of the denaturing reactor to carry out the denaturing reaction. The reaction solution was discharged so that the liquid level in the reactor was 70% of the entire reactor, and an antioxidant (2,6-di-tert-butyl-4-hydroxytoluene (BHT) was added to the effluent. ) 0.048 g / min (n-hexane solution), S-RAE oil (manufactured by JX Nippon Mining & Energy Co., Ltd., NC-140) as process oil was continuously added at 5.80 g / min. A mixture (A) of a diene copolymer and a solvent was obtained.

  The mixture (A) of the conjugated diene copolymer and the solvent was composed of 84 parts by mass of normal hexane, 16 parts by mass of the conjugated diene polymer, and 6.0 parts by mass of process oil. Here, as a result of analyzing the conjugated diene polymer by the measurement method described above, the amount of bound styrene was 27% by weight, the amount of bound butadiene was 73% by weight, the amount of vinyl bonds in butadiene was 65%, and the molecular weight in terms of polystyrene was the weight average molecular weight ( Mw) was 1.1 million, and the molecular weight distribution (Mw / Mn) was 2.2. Moreover, the Mooney viscosity of the conjugated diene polymer containing oil after the devolatilization step described later was 55.

(Production Example 2) Mixture of conjugated diene polymer and solvent (B)
Except having adjusted the content of process oil to 3.0 mass parts, it manufactured by the manufacturing method similar to manufacture example 1, and obtained the mixture (B) of the conjugated diene polymer and the solvent. The mixture (B) is the same as the mixture (A) in the amount of solvent and the structure of the conjugated diene polymer. The Mooney viscosity of the conjugated diene polymer containing oil was 70.

(Production Example 3) Mixture of Conjugated Diene Polymer and Solvent (C)
Except not using process oil at all, it manufactured by the manufacturing method similar to manufacture example 1, and obtained the mixture (C) of the conjugated diene polymer and the solvent. The mixture (C) is the same as the mixture (A) in the amount of solvent and the structure of the conjugated diene polymer. The Mooney viscosity of the conjugated diene polymer was 90.

Example 1 Conjugated Diene Polymer P1
In a twin screw kneader having a screw diameter (D) of 150 mm and a ratio (L / D) of screw length (L) to screw diameter (D) of 6.0, the mixture (A) is fed from the supply port to 50 kg / h. Continuously fed. At this time, the screw rotation speed and the rotation direction when viewed from the motor drive unit were 100 rpm counterclockwise on both axes. The mixture (A) was heated while supplying a heat transfer oil at 200 ° C. to the jacket of the kneader. The vent port was connected to a vacuum pump through piping, and the inside of the apparatus was kept at 100 torr. The thermal conductivity at 100 ° C. of the main member (carbon steel) of the twin screw kneader body was 54 W / m · K. A metal (carbon steel) guide part having a thermal conductivity of 48 W / m · K at 100 ° C. was installed so as to cover the boundary between the screw and the inner wall surface of the evaporation chamber. The mixture (A) was concentrated while being conveyed by a screw, and finally a solid conjugated diene polymer P1 was obtained. The devolatilized solvent gas was condensed through a condenser through a vent port and recovered as a liquid. During operation, a small amount of deposit on the guide parts was observed, but no deposit on the inner wall of the evaporation chamber was observed. The residual volatile content of the conjugated diene polymer P1 was 0.65% by mass, and no gel was detected. As a result, it was within the allowable range (possible).

Example 2 Conjugated Diene Polymer P2
The solid conjugated diene polymer P2 was prepared in the same manner as in Example 1 except that the guide part used was changed to a metal (stainless steel) having a thermal conductivity of 36 W / m · K at 100 ° C. Obtained. The devolatilized solvent gas was condensed through a condenser through a vent port and recovered as a liquid. During operation, almost no deposits were found on the guide parts, and no deposits were found on the inner wall of the evaporation chamber. The residual volatile content of the conjugated diene polymer P2 was 0.73% by mass, and no gel was detected. As a result, it was good (good).

(Example 3) Conjugated diene polymer P3
A solid conjugated diene polymer P3 was prepared in the same manner as in Example 1 except that the guide parts used were changed to nonmetals (alumina ceramics) having a thermal conductivity of 24 W / m · K at 100 ° C. Got. The devolatilized solvent gas passed through the vent port, was condensed by the condenser, and was recovered as a liquid. During operation, almost no deposits were found on the guide parts, and no deposits were found on the inner wall of the evaporation chamber. The residual volatile content of the conjugated diene polymer P3 was 0.59% by mass, and no gel was detected. As a result, it was good (good).

Example 4 Conjugated Diene Polymer P4
The solid conjugated diene polymer P4 was obtained in the same manner as in Example 1 except that the guide part used was changed to a nonmetal (alumina ceramic) having a thermal conductivity of 13 W / m · K at 100 ° C. Got. The devolatilized solvent gas passed through the vent port, was condensed by the condenser, and was recovered as a liquid. During operation, almost no deposits were found on the guide parts, and no deposits were found on the inner wall of the evaporation chamber. The residual volatile content of the conjugated diene polymer P4 was 0.68% by mass, and no gel was detected. As a result, it was good (good).

(Example 5) Conjugated diene polymer P5
A solid conjugated diene polymer P5 was prepared in the same manner as in Example 1 except that the guide parts used were changed to a resin (Teflon) having a thermal conductivity of 1.0 W / m · K at 100 ° C. Got. The devolatilized solvent gas passed through the vent port, was condensed by the condenser, and was recovered as a liquid. During operation, no deposits were observed on the guide parts, and no deposits were observed on the inner wall of the evaporation chamber. The residual volatile content of the conjugated diene polymer P5 was 0.62% by mass, and no gel was detected. As a result, it was very good (excellent).

(Example 6) Conjugated diene polymer P6
The used guide parts are a metal plate (carbon steel) having a thickness of 100 μm and a thermal conductivity of 48 W / m · K at 100 ° C. on the surface of a metal (carbon steel) having a thermal conductivity of 54 W / m · K at 100 ° C. ) Was carried out by the same method as in Example 1 except that the solid conjugated diene polymer P6 was obtained. The devolatilized solvent gas passed through the vent port, was condensed by the condenser, and was recovered as a liquid. During operation, a small amount of deposit on the guide parts was observed, but no deposit on the inner wall of the evaporation chamber was observed. The residual volatile content of the conjugated diene polymer P6 was 0.82% by mass, and no gel was detected. As a result, it was within the allowable range (possible).

(Example 7) Conjugated diene polymer P7
The non-metallic plate (alumina) having a thickness of 100 μm and a thermal conductivity of 13 W / m · K at 100 ° C. on the surface of a metal (carbon steel) having a thermal conductivity of 54 W / m · K at 100 ° C. The solid conjugated diene polymer P7 was obtained in the same manner as in Example 1 except that the ceramics was changed to the bonded one. The devolatilized solvent gas passed through the vent port, was condensed by the condenser, and was recovered as a liquid. During operation, a small amount of deposit on the guide parts was observed, but no deposit on the inner wall of the evaporation chamber was observed. The residual volatile content of the conjugated diene polymer P7 was 0.79% by mass, and no gel was detected. As a result, it was within the allowable range (possible).

(Example 8) Conjugated diene polymer P8
The non-metallic plate (alumina) with a thickness of 2000 μm and a thermal conductivity of 24 W / m · K at 100 ° C. on the surface of a metal (carbon steel) with a thermal conductivity of 48 W / m · K at 100 ° C. The solid conjugated diene polymer P8 was obtained in the same manner as in Example 1 except that the ceramics was changed to the bonded one. The devolatilized solvent gas passed through the vent port, was condensed by the condenser, and was recovered as a liquid. During operation, almost no deposits were found on the guide parts, and no deposits were found on the inner wall of the evaporation chamber. The residual volatile content of the conjugated diene polymer P8 was 0.60% by mass, and no gel was detected. As a result, it was good (good).

(Example 9) Conjugated diene polymer P9
The solid conjugated diene polymer P9 was obtained in the same manner as in Example 1, except that the mixture (B) was used instead of the mixture (A). The devolatilized solvent gas passed through the vent port, was condensed by the condenser, and was recovered as a liquid. During operation, a small amount of deposit on the guide parts was observed, but no deposit on the inner wall of the evaporation chamber was observed. The residual volatile content of the conjugated diene polymer P9 was 0.41% by mass, and no gel was detected. As a result, it was within the allowable range (possible).

(Example 10) Conjugated diene polymer P10
The solid conjugated diene polymer P10 was obtained in the same manner as in Example 4 except that the mixture (B) was used instead of the mixture (A). The devolatilized solvent gas passed through the vent port, was condensed by the condenser, and was recovered as a liquid. During operation, almost no deposits were found on the guide parts, and no deposits were found on the inner wall of the evaporation chamber. The residual volatile content of the conjugated diene polymer P10 was 0.35% by mass, and no gel was detected. As a result, it was good (good).

(Example 11) Conjugated diene polymer P11
The solid conjugated diene polymer P11 was obtained in the same manner as in Example 1 except that the raw material used was the mixture (C) instead of the mixture (A). The devolatilized solvent gas passed through the vent port, was condensed by the condenser, and was recovered as a liquid. During operation, a small amount of deposit on the guide parts was observed, but no deposit on the inner wall of the evaporation chamber was observed. The residual volatile content of the conjugated diene polymer P11 was 0.23% by mass, and no gel was detected. As a result, it was within the allowable range (possible).

(Example 12) Conjugated diene polymer P12
The solid conjugated diene polymer P12 was obtained in the same manner as in Example 4 except that the mixture (C) was used instead of the mixture (A). The devolatilized solvent gas passed through the vent port, was condensed by the condenser, and was recovered as a liquid. During operation, almost no deposits were found on the guide parts, and no deposits were found on the inner wall of the evaporation chamber. The residual volatile content of the conjugated diene polymer P12 was 0.31% by mass, and no gel was detected. As a result, it was good (good).

Comparative Example 1 Conjugated Diene Polymer P13
In a twin screw kneader having a screw diameter (D) of 150 mm and a ratio (L / D) of the screw length (L) to the screw diameter (D) of 6.0, the mixture (A) is fed from the supply port at 50 kg / h. Continuously fed. At this time, the screw rotation speed and the rotation direction when viewed from the motor drive unit were 100 rpm counterclockwise on both axes. The mixture (A) was heated while supplying a heat transfer oil at 200 ° C. to the jacket of the kneader. The vent port was connected to a vacuum pump through piping, and the inside of the apparatus was kept at 100 torr. The main member (carbon steel) of the twin-screw kneader body had a thermal conductivity of 54 W / m · K at 100 ° C. The mixture (A) was concentrated while being conveyed by a screw, and finally a solid conjugated diene polymer P13 was obtained. The devolatilized solvent gas passed through the vent port, was condensed by the condenser, and was recovered as a liquid. During operation, deposits were found to deposit on the inner wall of the evaporation chamber, and a powdery concentrate flew to the vent port. After 12 hours, the vent was clogged. The residual volatile content was 0.57% by mass, and no gel was detected immediately after the start of operation, but after 12 hours of operation, the gel content was 5.3% by mass. Since no guide parts were provided, it was inferred that the flying powdery substance blocked the vent, and the polymer adhering to the inside of the apparatus was altered by heating for a long time to produce a gel. As a result, it was out of the allowable range (impossible).

Comparative Example 2 Conjugated Diene Polymer P14
In a twin screw kneader having a screw diameter (D) of 150 mm and a ratio (L / D) of the screw length (L) to the screw diameter (D) of 6.0, the mixture (A) is fed from the supply port at 50 kg / h. Continuously fed. At this time, the screw rotation speed and the rotation direction when viewed from the motor drive unit were 100 rpm counterclockwise on both axes. The mixture (A) was heated while supplying a heat transfer oil at 200 ° C. to the jacket of the kneader. The vent port was connected to a vacuum pump through piping, and the inside of the apparatus was kept at 100 torr. The main member (carbon steel) of the twin-screw kneader body had a thermal conductivity of 54 W / m · K at 100 ° C. A metal (carbon steel) guide part having a thermal conductivity of 54 W / m · K at 100 ° C. was installed so as to cover the boundary between the screw and the inner wall surface of the evaporation chamber. The mixture (A) was concentrated while being conveyed by a screw, and finally a solid conjugated diene polymer P14 was obtained. The devolatilized solvent gas passed through the vent port, was condensed by the condenser, and was recovered as a liquid. During operation, deposits were found on the guide parts, deposits were found on the inner wall of the evaporation chamber, and the powdered concentrate jumped to the vent opening. It was. The residual volatile content was 0.49% by mass, and no gel was detected. As a result, it was out of the allowable range (impossible).

Comparative Example 3 Conjugated Diene Polymer P15
In a twin screw kneader having a screw diameter (D) of 150 mm and a ratio (L / D) of the screw length (L) to the screw diameter (D) of 6.0, the mixture (A) is fed from the supply port at 50 kg / h. Continuously fed. At this time, the screw rotation speed and the rotation direction when viewed from the motor drive unit were 100 rpm counterclockwise on both axes. The mixture (A) was heated while supplying a heat transfer oil at 200 ° C. to the jacket of the kneader. The vent port was connected to a vacuum pump through piping, and the inside of the apparatus was kept at 100 torr. The main member (carbon steel) of the twin-screw kneader body had a thermal conductivity of 54 W / m · K at 100 ° C. On the surface of a nonmetal (alumina ceramic) whose thermal conductivity at 100 ° C. is 24 W / m · K so as to cover the boundary between the screw and the inner wall surface of the evaporation chamber, the thermal conductivity at 100 ° C. with a thickness of 100 μm The guide part which bonded the metal plate (carbon steel) which is 54 W / m * K was installed. The mixture (A) was concentrated while being conveyed by a screw, and finally a solid conjugated diene polymer P15 was obtained. The devolatilized solvent gas passed through the vent port, was condensed by the condenser, and was recovered as a liquid. During operation, deposits were found on the guide parts, deposits were found on the inner wall of the evaporation chamber, and the powdered concentrate jumped to the vent opening. It was. The residual volatile content was 0.55% by mass, and no gel was detected. As a result, it was outside the allowable range (impossible).

  DESCRIPTION OF SYMBOLS 1 ... Input port, 2 ... Apparatus outer wall surface, 3 ... Apparatus inner wall surface, 4 ... Evaporation chamber, 5 ... Vent port, 6 ... Guide part, 7 ... Screw, 8 ... Discharge port.

Claims (4)

A production process for producing a mixture comprising a conjugated diene polymer and a solvent;
Using a device having a biaxial screw, devolatilizing the solvent, and
The apparatus has one or more vent ports for exhausting the gas component of the devolatilized solvent to the outside of the apparatus,
A guide part is provided between the inner wall surface of the device having the biaxial screw and the inner wall surface of the device on the side where the vent port is disposed, and the biaxial screw.
The thermal conductivity at 100 ° C. of the surface of the guide part is less than 50 W / m · K.
A method for producing a conjugated diene polymer. The manufacturing method of the conjugated diene polymer of Claim 1 whose heat conductivity in 100 degreeC of the said guide parts is less than 50 W / m * K. The guide part includes a non-metallic material,
The thermal conductivity at 100 ° C of the nonmetallic material is less than 50 W / m · K.
Or the manufacturing method of the conjugated diene polymer of 2. The heat conductivity at 100 ° C. of the surface of the guide part is less than 15 W / m · K.
The manufacturing method of the conjugated diene polymer as described in any one of Claims 1-3.