JP2014189571A - Method for manufacturing a modified cis-1,4-polybutadiene - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a modified cis-1,4-polybutadiene excellent in terms of workability and low-loss profile and to improve the degree of modification thereof.SOLUTION: The provided method for manufacturing a modified cis-1,4-polybutadiene is a method for manufacturing a modified cis-1,4-polybutadiene by polymerizing 1,3-butadiene in the presence of a polymerization catalyst including a transition metal compound and an organoaluminum compound so as to manufacture cis-1,4-polybutadiene and then charging, into this polymerization system, an organohalogen compound and a specified 1- through 3-substituted aromatic compound so as to react the cis-1,4-polybutadiene and the specified 1- through 3-substituted aromatic compound where a modifying reaction is induced by using the specified 1- through 3-substituted aromatic compound after yet-to-be-reacted monomers and other olefin gases have been removed from the reaction system.

Description

  The present invention relates to a process for producing a modified cis-1,4-polybutadiene which is excellent in processability and low-loss properties useful as a rubber material, and easily improves the degree of modification.

  Many proposals have been made on polymerization catalysts for 1,3-butadiene, and particularly high cis-1,4-polybutadiene, that is, polybutadiene having a high cis-1,4 bond content is thermally and mechanically. Many polymerization catalysts have been developed due to their superior properties.

  For example, Patent Document 1 discloses a method for producing high cis-1,4-polybutadiene in which 1,3-butadiene is polymerized using a catalyst comprising a cobalt compound, an acidic metal halide, an alkylaluminum compound, and water. .

  Patent Document 2 discloses a method in which 1,3-butadiene is polymerized in a solvent composed of linear or branched aliphatic hydrocarbons using a catalyst composed of diethylaluminum chloride, water, and cobalt octate. Is disclosed.

  In high cis-1,4-polybutadiene, the polymer chain having a small degree of branching, that is, linear type high cis-1,4-polybutadiene has excellent heat resistance, rebound resilience, and the like. However, as compared with branch-type high cis-1,4-polybutadiene having a high degree of branching, processability is reduced when producing a compound obtained by compounding carbon black or the like with rubber. A method was sought.

  As a method for improving the processability of polybutadiene, Patent Document 3 discloses a method of treating a polybutadiene polymerization solution with an organoaluminum compound and an alkyl halide compound. Patent Document 4 describes a method in which a rubber having an unsaturated bond is dissolved in a solvent and an organic acid halide is reacted in the presence of a Lewis acid to modify the rubber. All of these methods require a step of modifying the polymer after the polymerization step, and it has been desired to develop a method that saves complicated operations.

  On the other hand, as a measure for improving the heat build-up of the rubber composition, in recent years, an increasing number of cases are using silica as a reinforcing material instead of carbon black. However, since there is a polar silanol group on the surface of silica, silica has low affinity with hydrocarbon structures such as polybutadiene, which makes it easier for silica particles to aggregate and disperse in the rubber compounded with silica. There was a problem that the sex became worse. As a result, when the silica aggregate breaks down, that is, the Payne effect occurs, a strong silica-silica interaction is observed inside the silica aggregate, and a large hysteresis loss occurs between the silica and rubber, causing exothermic deterioration. It was.

  As measures for enhancing the affinity and interaction between the polar silica surface and the nonpolar rubber matrix, the use of a silane coupling agent having a dual function and chemical modification of rubber have been intensively studied. As a chemical modification technique for rubber, many of the high-cis 1,4-polybutadienes chemically modified use a variety of effective alkoxysilane coupling agents after living polymerization of 1,3-butadiene using a rare earth catalyst. Thus, a method for functionalizing molecular ends has been reported.

  Patent Document 5 discloses a method for improving cold flow properties by polymerizing polybutadiene rubber with a cobalt compound and further reacting with an acid halide, a halogen-containing sulfur compound, a mercapto group-containing alkoxysilane compound, etc., if necessary. Have been described.

  Thereafter, for the purpose of improving the balance between processability and low loss, polybutadiene rubber is polymerized with a cobalt compound and then modified with a predetermined amount of an organic halogen compound (Patent Documents 6 and 7). However, from the viewpoint of the recent low environmental load and energy saving, there is a growing demand for further improvements in workability and low loss.

Japanese Patent Publication No.38-1243 Japanese Patent Publication No. 61-54808 Japanese Patent Laid-Open No. 51-63891 JP-A-61-225202 JP 2001-114817 A JP 2004-211048 A JP 2011-79954 A

  An object of the present invention is to provide a modified cis-1,4-polybutadiene excellent in processability and low loss and a method for producing the same, and to further improve the degree of modification.

  As a result of intensive studies to solve the above problems, the present inventors polymerized 1,3-butadiene with a polymerization catalyst containing a transition metal compound and an organoaluminum compound to convert cis-1,4-polybutadiene. Then, an organic halogen compound and a 1-3 substituted aromatic compound represented by the following general formula (1) are added to the polymerization system, and cis-1,4-polybutadiene and the following general formula (1) are added. In the method for producing a modified cis-1,4-polybutadiene, the unreacted monomer and other olefin gas are removed from the reaction system. Subsequently, it was found that a cis-1,4-polybutadiene having a higher degree of modification can be synthesized by performing a modification reaction using the 1-3 substituted aromatic compound according to claim 1. Thus, the present invention has been completed.

式（１）において、Ｙは水素、水酸基、アルケニル基または炭素数１〜１０のアルコキシ基、Ｚ¹、Ｚ²は水素、水酸基、アルキル基または炭素数１〜１０のアルコキシ基を示す。

In Formula (1), Y represents hydrogen, a hydroxyl group, an alkenyl group, or an alkoxy group having 1 to 10 carbon atoms, and Z ¹ and Z ² represent hydrogen, a hydroxyl group, an alkyl group, or an alkoxy group having 1 to 10 carbon atoms.

  It is preferable that the removal amount of monomer and other olefin gas is 1 to 3.5 times the volume of gas in the container.

  The monomer and other olefin gas are preferably butadiene and butene.

  It is preferable that the 1-3 substituted aromatic compound is at least one selected from the group consisting of phenol derivatives, catechol derivatives, resorcin derivatives, hydroquinone derivatives, and 2-3 substituted aromatic alkenyl compounds.

  Since the modified cis-1,4-polybutadiene of the present invention has a polar functional group that interacts with silica particles in the molecule, the rubber composition using the modified cis-1,4-polybutadiene has an excellent low-loss property because silica aggregation is suppressed. In particular, it can be suitably used for tires. In addition, the method for producing the modified cis-1,4-polybutadiene of the present invention does not require separation after the production of cis-1,4-polybutadiene, and does not require simple and complicated operations. Is the method. Furthermore, there is an effect of easily improving the degree of modification.

It is a figure for the modification degree calculation of the modified cis-1,4-polybutadiene relating to the present invention.

(1) Production of cis-1,4-polybutadiene cis-1,4-polybutadiene can be produced by polymerizing 1,3-butadiene in the presence of a polymerization catalyst containing a transition metal compound.

(Polymerization catalyst)
Examples of the transition metal compound used for the polymerization catalyst include a cobalt compound, a nickel compound and a titanium compound, and a cobalt compound is preferably used. As the catalyst system, a catalyst system comprising a cobalt compound, a halogen-containing aluminum compound and water or a catalyst system comprising a cobalt compound, a halogen-containing aluminum compound, water and an organoaluminum compound is preferred.

  As a cobalt compound of the cobalt-based catalyst, a salt or complex of cobalt is preferably used, and cobalt chloride, cobalt bromide, cobalt nitrate, cobalt 2-ethylhexanoate (cobalt octoate), cobalt naphthenate, Cobalt salts such as cobalt octenoate, cobalt acetate, cobalt malonate, cobalt bisacetylacetonate, trisacetylacetonate, ethyl acetoacetate cobalt, cobalt halide triarylphosphine complex, trialkylphosphine Examples thereof include organic base complexes such as fin complexes, pyridine complexes and picoline complexes, and ethyl alcohol complexes.

Examples of the halogen-containing aluminum compound in the cobalt-based catalyst composition include R ¹ _3-n AlX _n (wherein R ¹ represents a hydrocarbon group having 1 to 10 carbon atoms, X represents a halogen, and n represents a number of 1 to 2). Is preferred). Examples thereof include dialkylaluminum halides such as dialkylaluminum chloride and dialkylaluminum bromide, alkylaluminum sesquichlorides such as alkylaluminum sesquichloride and alkylaluminum sesquibromide, and alkylaluminum dihalides such as alkylaluminum dichloride and alkylaluminum dibromide. Specific examples of the compound include diethylaluminum monochloride, diethylaluminum monobromide, dibutylaluminum monochloride, ethylaluminum sesquichloride, ethylaluminum dichloride, dicyclohexylaluminum monochloride, and diphenylaluminum monochloride. Ride and diisobutylaluminum monochloride are preferred.

As the organoaluminum compound in the cobalt-based catalyst composition, R ² ₃ Al (wherein, R ² represents a hydrocarbon group having 1 to 10 carbon atoms.) Preferably represented by. For example, a trialkylaluminum compound, more specifically, triethylaluminum, trimethylaluminum, trinormalpropylaluminum, trinormalbutylaluminum, triisobutylaluminum, trihexylaluminum, trioctylaluminum and the like can be mentioned.

Aluminoxane may also be used. The aluminoxane is obtained by bringing an organoaluminum compound and a condensing agent into contact with each other, and has a general formula (—Al (R ′
And a chain aluminoxane represented by O-) n or cyclic aluminoxane.
(R ′ is a hydrocarbon group having 1 to 10 carbon atoms, including those partially substituted with a halogen atom and / or an alkoxy group. N is the degree of polymerization and is 5 or more, preferably 10 or more) . R
Examples of 'include methyl, ethyl, propyl, and isobutyl groups, with methyl and ethyl groups being preferred. Examples of the organoaluminum compound used as an aluminoxane raw material include trialkylaluminums such as trimethylaluminum, triethylaluminum, and triisobutylaluminum, and mixtures thereof.

(Polymerization of 1,3-butadiene)
The polymerization of 1,3-butadiene is performed, for example, as follows. First, 1,3-butadiene and a solvent are charged into a pressure-resistant container whose interior is purged with nitrogen, and then water, a molecular weight regulator and a halogen-containing organoaluminum compound are charged and stirred. After bringing the pressure vessel to a predetermined temperature, a transition metal polymerization catalyst is charged and polymerization is started. The polymerization is carried out under normal pressure or a pressure up to about 10 atm (gauge pressure).

When a cobalt-based catalyst composition comprising a cobalt compound, a halogen-containing organoaluminum compound, and water is used as the polymerization catalyst, 1 × 10 ⁻⁷ to 1 × for the cobalt compound with respect to 1 mol of 1,3-butadiene. A range of 10 ⁻³ mol is preferred. The halogen-containing organoaluminum compound is preferably in the range of 1 × 10 ⁻⁵ to 1 × 10 ⁻¹ mol. Moreover, it is preferable that it exists in the range of 1 * 10 < ^-5 > ^-1 * 10 <^-1> mol about water.

As the order of addition of the catalyst components, it is preferable to add water in an inert solvent and mix uniformly, add a halogen-containing organoaluminum compound, add a cobalt compound, and start polymerization. After adding the halogen-containing organoaluminum compound, it is preferable to age for a predetermined time and add the cobalt compound. The aging time is preferably 0.1 to 24 hours, and the aging temperature is preferably 0 to 80 ° C.

  The addition amount of the halogen-containing organoaluminum compound used in the cobalt-based catalyst composition is preferably 0.9 to 2.0 times, more preferably 1.0 to 1.8 times the amount of water to be added. When it is larger than this range, desired physical properties cannot be obtained, and when it is smaller than this range, workability is deteriorated. The addition amount of the halogen-containing organoaluminum compound and the ratio of water to be added are particularly important in controlling the linearity of polybutadiene.

  Polymerization solvents include aromatic hydrocarbons such as toluene, benzene and xylene, aliphatic hydrocarbons such as normal hexane, butane, heptane and pentane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, 1-butene, cis Examples include olefinic hydrocarbons such as C4 fractions such as 2-butene and trans-2-butene, hydrocarbon solvents such as mineral spirits, solvent naphtha, and kerosene, and halogenated hydrocarbon solvents such as methylene chloride. It is done. Further, 1,3-butadiene itself may be used as a polymerization solvent.

Among these, benzene, cyclohexane, or a mixture of cis-2-butene and trans-2-butene is preferably used.

  As the molecular weight regulator, for example, non-conjugated dienes such as cyclooctadiene and allene, or α-olefins such as ethylene, propylene, and 1-butene can be used. Particularly preferred is cyclooctadiene, preferably 1 to 40 mmol, more preferably 5 to 30 mmol per mole of 1,3-butadiene. Use of an amount outside this range is not preferable because the processability of the polymer is deteriorated.

The polymerization temperature is preferably in the range of -30 to 100 ° C, particularly preferably in the range of 30 to 80 ° C.
The polymerization time is preferably in the range of 5 minutes to 12 hours, particularly preferably 10 minutes to 6 hours. Also,

(Properties of cis-1,4-polybutadiene)
The Mooney viscosity of the cis-1,4-polybutadiene used in the present invention is 10 to 120, preferably 15 to 100, and more preferably 20 to 90. If the Mooney viscosity is larger than the above range, the processing is difficult, and if it is smaller than the above range, the wear resistance and low loss property are deteriorated.

Further, the ratio (Tcp / ML _{1 + 4} ) of the solution viscosity (Tcp) and Mooney viscosity of a 5 wt% toluene solution is preferably 1.0 to 6.0. Further, Mw / Mn is preferably 1.2 to 5.0, and particularly preferably 1.5 to 4.5.

(2) Modification of cis-1,4-polybutadiene The modified cis-1,4-polybutadiene of the present invention is a cis-1,4-polybutadiene and a modifier represented by the following general formula in the presence of a Lewis acid and an organic halogen compound. It can manufacture by making the 1-3 valent aromatic compound represented by (1) react.

式（１）において、Ｙは水酸基、アルケニル基または炭素数１〜１０のアルコキシ基、Ｚ¹、Ｚ²は水素、水酸基、アルキル基または炭素数１〜１０のアルコキシ基を示す。

In the formula (1), Y represents a hydroxyl group, an alkenyl group or an alkoxy group having 1 to 10 carbon atoms, and Z ¹ and Z ² represent hydrogen, a hydroxyl group, an alkyl group or an alkoxy group having 1 to 10 carbon atoms.

(Modifier)
Examples of the modifier include anisole, phenetole, n-propoxybenzene, isopropoxybenzene, n-butoxybenzene, isobutoxybenzene, sec-butoxybenzene, n-pentyloxybenzene, isopentyloxybenzene, neopentyloxybenzene, n-hexyloxybenzene, (2-ethylbutyloxy) benzene, n-octyloxybenzene, n-decyloxybenzene, veratrol, 1,3-dimethoxybenzene, 1,4-dimethoxybenzene, 1,2-diethoxybenzene 1,3-diethoxybenzene, 1,4-diethoxybenzene, 1,2-di-n-propoxybenzene, 1,3-di-n-propoxybenzene, 1,4-di-n-propoxybenzene, 1,2-di-n-butoxybenzene, 1 3-di-n-butoxybenzene, 2-ethoxy-methoxybenzene, 3-ethoxy-methoxybenzene, 4-ethoxy-methoxybenzene, 2-propoxy-methoxybenzene, 3-propoxy-methoxybenzene, 4-propoxy-methoxybenzene 1,4-di-n-butoxybenzene, 1,2-methylenedioxybenzene, 1,2,3-trimethoxybenzene, 1,2,4-trimethoxybenzene, 1,3,5-trimethoxybenzene , Phenol, 2-methoxyphenol, 3-methoxyphenol, 4-methoxyphenol, 2-ethoxyphenol, 3-ethoxyphenol, 4-ethoxyphenol, 2,6-dimethoxyphenol, 3,4-dimethoxyphenol, 3, 5 -Dimethoxyphenol, catechol, 3-metho Cicatechol, resorcinol, 2-methoxyresorcinol, 5-ethoxyresorcinol, hydroquinone, hydroquinone monomethyl ether, hydroquinone dimethyl ether, anethole, safrole, isosafrole, eugenol, methyl eugenol, isoeugenol, methylisoeugenol, pyrogallol, pyrogallol trimethyl ether, phlorog Compounds such as lucinol and phloroglucinol trimethyl ether and alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group, n-pentyl group, isopentyl group Phenol, anisole having one or two neopentyl groups, phenyl groups, etc., catechol having the aforementioned alkyl groups, Ayacoal, Guetor, etc. are listed. Among these, it is preferable to use one or more modifiers selected from the group consisting of alkoxybenzenes, catechol derivatives, and resorcin derivatives. Particularly, anisole, phenetole, anethole, veratrol, 1,3-dimethoxybenzene, 1,3-di Ethoxybenzene, 1,2-methylenedioxybenzene, safrole, isosafrole, and methylisoeugenol are preferred. Moreover, there is no problem even if two or more of these are used in combination.

(Lewis acid)
As the Lewis acid used for the modification reaction, a generally known Lewis acid can be used. Typical examples are metal or metalloid halides such as Be, B, Al, Si, P, S, Ti, V, Fe, Zn, Ga, Ge, As, Se, Zr, Nb, Mo, Elements such as Cd, Sn, Sb, Te, Hf, Ta, W, Hg, Bi, U, or oxygen-element conjugate halides such as PO, SeO, SO, SO ₂ , VO, or organic halides; Or these complexes. More specifically, BF ₃ , BF ₃ .O (C ₂ H ₅ ) ₂ , (CH ₃ ) ₂ BF, BCl ₃ , AlCl ₃ , AlBr ₃ , (C ₂ H ₅ ) AlCl ₂ , POCl ₃ , TiCl ₄ , VCl ₄ , MoCl ₆ , SnCl ₄ , (CH ₃ ) SnCl ₃ , SbCl ₅ , TeCl ₄ , TeBr ₄ , FeCl ₃ , WCl ₆ , Sc (OTf) ₃ , Hf (OTf) ₃ , Sb (OTf) ₃ Bi (OTf) ₃ , and Ga (OTf) ₃ . Among these, aluminum halides or organic halides are preferable, and for example, the same halogen-containing aluminum compounds used for the cobalt-based catalyst can be used.

(Organic halogen compounds)
The organic halogen compound used for the modification reaction is not particularly limited as long as it reacts with a Lewis acid to generate a carbocation. For example, an alkyl halide represented by the following general formula (2) can be used. .

式（２）において、Ｒ³、Ｒ⁴は水素、クロル、ブロムまたは炭素数１〜１２のアルキル基、アリール基、クロル置換アルキル基、アルコキシ基などであり、Ｒ⁵はクロル、ブロムまたは炭素数１〜６のアルキル基、アリール基、クロル置換アルキル基、アルコキシ基などであり、Ｘはクロル、ブロムなどのハロゲンである。Ｒ³およびＲ⁴が水素である場合は、Ｒ⁵はアリール基であることが好ましい。上記のアルキル基は、飽和あるいは不飽和であってもよく、また、直鎖状、分岐状または環状のものであってもよい。

In the formula (2), R ³ and R ⁴ are hydrogen, chloro, bromo or an alkyl group having 1 to 12 carbon atoms, an aryl group, a chloro-substituted alkyl group, an alkoxy group, etc., and R ⁵ is chloro, bromo or carbon number. 1-6 alkyl groups, aryl groups, chloro-substituted alkyl groups, alkoxy groups and the like, and X is a halogen such as chloro and bromo. When R ³ and R ⁴ are hydrogen, R ⁵ is preferably an aryl group. The above alkyl group may be saturated or unsaturated, and may be linear, branched or cyclic.

  Specific examples of the compound include chlorides, bromides, and iodides such as methyl, ethyl, isopropyl, isobutyl, t-butyl, phenyl, benzyl, benzoyl, and benzylidene. Further, methyl chloroformate, bromoformate, chlorodiphenylmethane, chlorotriphenylmethane, and the like can be given. In the present invention, tertiary alkyl halides, particularly tertiary alkyl halides having 4 to 12 carbon atoms, are preferred in view of the stability of the generated carbocation, and specifically, t-butyl chloride and t -Butyl bromide is preferred.

  Moreover, the acyl halide compound represented by following General formula (3) can be used.

式（３）において、Ｒ⁶は水素、クロル、ブロムまたは炭素数１〜１２のアルキル基、アリール基、クロル置換アルキル基、アルコキシ基などであり、Ｘはクロル、ブロムなどのハロゲンである。

In the formula (3), R ⁶ is hydrogen, chloro, bromo or an alkyl group having 1 to 12 carbon atoms, an aryl group, a chloro-substituted alkyl group, an alkoxy group, and the like, and X is a halogen such as chloro and bromo.

(Denaturation reaction)
The modification reaction is preferably carried out after removing the unreacted monomer and other olefin gas remaining in the polymerization system after the polymerization is stopped. When the polymerization system contains a Lewis acid component such as a halogen-containing aluminum compound, it is preferable to carry out a modification reaction subsequent to the polymerization of 1,3-butadiene.

  The amount of the monomer and other olefin gas removed is preferably 1 to 3.5 times, more preferably 2 to 3.5 times the volume of gas in the container. If it is 3.5 times or more, stirring becomes difficult, and if it is 1 time or less, the effect of removing the gas becomes thin. Here, the capacity of the gas in the container is obtained by subtracting the volume of the charged butadiene solution from the total capacity of the container.

  As for the pressure in the container, the gas is preferably removed to 0.2 MPa or less at 60 ° C., more preferably 0.1 MPa or less.

  When the modification reaction is carried out following the polymerization of 1,3-butadiene, a modifier is added after the polymerization, and then an organic halogen compound is added at a predetermined temperature, followed by stirring and mixing for a predetermined time. At this time, a Lewis acid may be added as necessary. The temperature at which the modifier is reacted with polybutadiene is 20 to 100 ° C, preferably 30 to 80 ° C. If it is higher than this temperature range, gelation is promoted, which is not preferable. On the other hand, when the temperature is lower than this temperature range, the modification reaction hardly occurs effectively. The reaction time is 1 minute to 600 minutes. Preferably, it is desirable to stir and mix for 10 minutes to 90 minutes.

The amount of the modifier is preferably 1 × 10 ^{−3 to} 100 mol, particularly 1 × 10 ⁻² to 10 mol with respect to 1 mol of 1,3-butadiene unit in cis-1,4-polybutadiene. preferable. Furthermore, the amount of the organic halogen compound is 0.05 to 50 times, preferably 1 to 20 times that of the halogen-containing organoaluminum compound during the polymerization reaction. If the amount is less than this amount, the modification reaction does not proceed sufficiently and the desired polymer may not be obtained. Moreover, when there are too many, gelation by reaction of polybutadiene molecules will be accelerated | stimulated and a desired polymer may not be obtained. After the denaturation reaction, the inside of the reaction vessel is released as necessary, and post-treatment such as washing and drying steps is performed.

(Denatured degree)
The degree of modification of the modified cis-1,4-polybutadiene of the present invention is calculated by a technique using gel permeation chromatography (GPC) measurement. This will be described in detail with reference to FIG.

  In FIG. 1, the vertical axis represents the ratio of the peak area value UV obtained from the UV absorbance of the polymer obtained by GPC measurement and the peak area value RI obtained from the differential refractive index (RI), the value of UV / RI.

The horizontal axis indicates a value of (1 / Mn) × 10 ⁴ , and Mn is the number average molecular weight. In FIG. 1, Li-BR (unmodified) is a plot of UV / RI values of a polymer itself obtained by polymerizing 1,3-butadiene by anionic polymerization using a Li-based catalyst, for five different types of polymers having a number average molecular weight Mn. It can be approximated as a straight line. In addition, Li-BR (modified) is polymerized by anionic polymerization using a Li-based catalyst, and then reacted with a polymerization terminal and 3,5-dimethoxybenzyl bromide to change the UV / RI values of five different types of polymers. This is plotted for a polymer having a number average molecular weight Mn and can be approximated as a straight line.

  In the case of anionic polymerization, since one polymer molecule and one modifier molecule react quantitatively, the Li / BR (modified) UV / RI value and Li-BR (unmodified) at a certain number average molecular weight (Mn1). The difference between the UV / RI values of A is A. This indicates the amount of change in the UV / RI value when one molecule of the modifying agent reacts with one molecular chain having the number average molecular weight (Mn1), and the degree of modification can be calculated based on this value.

  Similar to Li-BR, the modified cis-1,4-polybutadiene of the present invention having a number average molecular weight (Mn1) and the unmodified cis-1,4 obtained by the same method as used for modification. -For polybutadiene, when the UV / RI value is calculated and the difference is B, the modification degree of the modified cis-1,4-polybutadiene of the present invention can be expressed by the following equation.

  The degree of modification of the cis-1,4-polybutadiene of the present invention is not particularly limited, but is preferably more than 0.1 and more preferably more than 0.5. Further, the degree of modification preferably does not exceed 20, and more preferably does not exceed 15. If the degree of modification is 0.1 or less, the effect of modification may not be sufficient, and if the degree of modification is 20 or more, the characteristics of the original cis-1,4-polybutadiene may be impaired.

Number average molecular weight: Calculated using a calibration curve obtained from a molecular weight distribution curve obtained by GPC (manufactured by Shimadzu Corporation) using polystyrene as a standard substance and tetrahydrofuran as a solvent at a temperature of 40 ° C. Asked.

Degree of modification: As described above, A is the difference between the UV / RI value of Li-BR (modified) and the UV / RI value of Li-BR (unmodified) at the same number average molecular weight as the target example. The UV / RI value of the example was set as B, and was calculated from the following formula.
Degree of modification = B / A

Example 1
In a 1.5 liter stainless steel autoclave sufficiently purged with nitrogen, 500 mL of a cyclohexane-C4 fraction mixed solution containing 30.3% by weight of 1,3-butadiene (37.3% by weight of cyclohexane, cis-2) -Containing 31.2% by weight of a C4 fraction containing butene as the main component), then adding 1.1 mmol of water and 1.6 mmol of diethylaluminum monochloride, stirring, and adding 7.3 mmol of cyclooctadiene did. After the temperature of the autoclave was raised and the internal temperature reached 60 ° C., 0.003 mmol of cobalt octoate was added, and a polymerization reaction was performed at 60 ° C. for 25 minutes. After the polymerization reaction, 9 mmol of a modifier 1,3-dimethoxybenzene was added, and the gas in the autoclave was released to 3 L (3 times the removal amount) and 0.1 MPa. Next, the temperature was raised to 70 ° C., and 3.2 mmol of t-butyl chloride was added and reacted for 15 minutes. After adding the anti-aging agent, the polymer was precipitated with ethanol and vacuum dried at 80 ° C. for 3 hours. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

(Example 2)
The reaction was conducted in the same manner as in Example 1 except that 1,2-methylenedioxybenzene was used as the modifier. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

(Example 3)
The reaction was carried out in the same manner as in Example 1 except that the modifier was safrole. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

Example 4
The reaction was performed in the same manner as in Example 1 except that the modifier was isosafrole. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

(Example 5)
The reaction was performed in the same manner as in Example 1 except that the denaturant was anethole. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

(Example 6)
The reaction was performed in the same manner as in Example 1 except that veratrol was used as the modifier. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

(Example 7)
The reaction was conducted in the same manner as in Example 1 except that methyl isoeugenol (MIE) was used as the denaturing agent. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

(Reference Example 1)
In a 1.5 liter stainless steel autoclave sufficiently purged with nitrogen, 500 mL of a cyclohexane-C4 fraction mixed solution containing 30.3% by weight of 1,3-butadiene (37.3% by weight of cyclohexane, cis-2) -Containing 31.2% by weight of a C4 fraction containing butene as the main component), then adding 1.1 mmol of water and 1.6 mmol of diethylaluminum monochloride, stirring, and adding 7.3 mmol of cyclooctadiene did. After the temperature of the autoclave was raised and the internal temperature reached 60 ° C., 0.003 mmol of cobalt octoate was added, and a polymerization reaction was performed at 60 ° C. for 25 minutes. After the polymerization reaction, 9 mmol of a modifier 1,3-dimethoxybenzene was added, and the temperature was raised to 70 ° C. Subsequently, 3.2 mmol of t-butyl chloride was added and reacted for 15 minutes. After adding the anti-aging agent, the polymer was precipitated with ethanol and vacuum dried at 80 ° C. for 3 hours. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

(Reference Example 2)
The reaction was performed in the same manner as in Comparative Example 1 except that 1,2-methylenedioxybenzene was used as the modifier. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

(Reference Example 3)
The reaction was performed in the same manner as in Comparative Example 1 except that the modifier was safrole. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

(Reference Example 4)
The reaction was performed in the same manner as in Comparative Example 1 except that the modifier was isosafrole. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

(Reference Example 5)
The reaction was carried out in the same manner as in Comparative Example 1 except that the modifier was anethole. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

(Reference Example 6)
The reaction was performed in the same manner as in Comparative Example 1 except that veratrol was used as the modifier. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

(Reference Example 7)
The reaction was performed in the same manner as in Comparative Example 1 except that methyl isoeugenol was used as the modifying agent. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

(Reference Example 8)
In a 1.5 liter stainless steel autoclave sufficiently purged with nitrogen, 500 mL of a cyclohexane-C4 fraction mixed solution containing 30.3% by weight of 1,3-butadiene (37.3% by weight of cyclohexane, cis-2) -Containing 31.2% by weight of a C4 fraction containing butene as the main component), then adding 1.1 mmol of water and 1.6 mmol of diethylaluminum monochloride, stirring, and adding 7.3 mmol of cyclooctadiene did. After the temperature of the autoclave was raised and the internal temperature reached 60 ° C., 0.003 mmol of cobalt octoate was added, and a polymerization reaction was performed at 60 ° C. for 25 minutes. An anti-aging agent was added to terminate the polymerization, and the polymer was precipitated with ethanol, followed by vacuum drying at 80 ° C. for 3 hours. Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

  Table 1 shows the physical properties of the resulting cis-1,4-polybutadiene.

Claims (4)

1,3-butadiene is polymerized by a polymerization catalyst containing a transition metal compound and an organoaluminum compound to produce cis-1,4-polybutadiene. Then, an organic halogen compound and the following general formula (1) are contained in this polymerization system. The cis-1,4-polybutadiene is reacted with a 1-3 substituted aromatic compound represented by the following general formula (1) by adding a 1-3 substituted aromatic compound represented by In the method for producing modified cis-1,4-polybutadiene, after removing unreacted monomers and other olefin gas from the reaction system, the modified cis is subjected to a modification reaction using the above 1 to 3 substituted aromatic compounds. A method for producing -1,4-polybutadiene.

In Formula (1), Y represents hydrogen, a hydroxyl group, an alkenyl group, or an alkoxy group having 1 to 10 carbon atoms, and Z ¹ and Z ² represent hydrogen, a hydroxyl group, an alkyl group, or an alkoxy group having 1 to 10 carbon atoms. The modified cis-1,4-polybutadiene according to claim 1, wherein the removal amount of the monomer and other olefin gas according to claim 1 is 1 to 3.5 times the volume of gas in the container. Manufacturing method. The method for producing a modified cis-1,4-polybutadiene according to claim 1 or 2, wherein the monomer and the other olefin gas according to claim 1 are butadiene and butene.   The 1-3 substituted aromatic compound is at least one selected from the group consisting of phenol derivatives, catechol derivatives, resorcin derivatives, hydroquinone derivatives, and 2-3 substituted aromatic alkenyl compounds. Item 4. A method for producing a modified cis-1,4-polybutadiene according to any one of Items 1 to 3.

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