WO2014021244A1

WO2014021244A1 - Modified cis-1, 4-polybutadiene and method for producing same

Info

Publication number: WO2014021244A1
Application number: PCT/JP2013/070430
Authority: WO
Inventors: 雅人下川; 斯波　晃司; 村上　真人
Original assignee: 宇部興産株式会社
Priority date: 2012-07-30
Filing date: 2013-07-29
Publication date: 2014-02-06
Also published as: JPWO2014021244A1; MY169946A; CN104487459A; KR20150037853A; TWI602868B; KR102055471B1; JP6015758B2; TW201425421A; CN104487459B

Abstract

The purpose of the present invention is to provide: a modified cis-1, 4-polybutadiene which has excellent processability and low loss tangent; and a method for producing this modified cis-1, 4-polybutadiene. A method for producing a modified cis-1, 4-polybutadiene of the present invention does not require separation of cis-1, 4-polybutadiene after the production thereof, and is therefore an excellent production method which is simple and does not require complicated operations. The present invention is a modified cis-1, 4-polybutadiene which is obtained by reacting cis-1, 4-polybutadiene with a specific mono- to tri-substituted aromatic compound in the presence of a Lewis acid and an organic halogen compound.

Description

Modified cis-1,4-polybutadiene and method for producing the same

The present invention relates to a modified cis-1,4-polybutadiene which is useful as a rubber material and has excellent processability and low loss and a method for producing the same.

Many proposals have been made regarding 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 used. 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 of polymerizing 1,3-butadiene in a solvent composed of a linear or branched aliphatic hydrocarbon using a catalyst composed of diethylaluminum chloride, water, and cobalt octoate. Has been.

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 characteristics such as heat resistance and rebound resilience. 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. However, any of these methods requires a step of modifying the polymer after the polymerization step, and the development of a method that saves complicated operations is desired.

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 instead of carbon black as a reinforcing material. 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 a measure to strengthen 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 technology 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. Are listed.

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 Examined Patent Publication No. 61-54808 JP 51-63891 JP-A-61-225202 JP 2001-114817 A Japanese Patent Laid-Open No. 2004-211048 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.

As a result of intensive investigations to solve the above-mentioned problems, the present inventors have made a modification obtained by reacting cis-1,4-polybutadiene with a specific aromatic compound in the presence of a Lewis acid and an organic halogen compound. The present inventors have found that cis-1,4-polybutadiene is excellent in processability and low loss, and completed the present invention.
That is, in the first embodiment of the present invention, cis-1,4-polybutadiene is reacted with a 1-3 substituted aromatic compound represented by the following general formula (1) in the presence of a Lewis acid and an organic halogen compound. There is provided a modified cis-1,4-polybutadiene characterized by being obtained in the above.

In the 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 each represent hydrogen, a hydroxyl group, an alkyl group or an alkoxy group having 1 to 10 carbon atoms. .

In the modified cis-1,4-polybutadiene according to the first aspect of the present invention, the 1 to 3 substituted aromatic compound is a phenol derivative, a catechol derivative, a resorcin derivative, a hydroquinone derivative, or a 2 to 3 substituted aromatic system. It is preferably at least one selected from the group consisting of alkenyl compounds, and particularly preferably a catechol derivative or a resorcin derivative.

The Lewis acid is preferably an organoaluminum compound, and the organohalogen compound is preferably a tertiary alkyl halide having 4 to 12 carbon atoms.

Further, in the second aspect of the present invention, 1,3-butadiene is polymerized using a polymerization catalyst containing a transition metal compound and an organoaluminum compound to produce cis-1,4-polybutadiene, and then this polymerization is performed. An organic halogen compound and a 1- to 3-substituted aromatic compound represented by the following general formula (1) are added to the system, and the cis-1,4-polybutadiene is added in the presence of Lewis acid and the organic halogen compound. Provided is a process for producing a modified cis-1,4-polybutadiene, characterized by reacting with a 1 to 3 substituted aromatic compound represented by the following general formula (1).

In the method for producing a modified cis-1,4-polybutadiene according to the second aspect of the present invention, the transition metal compound is preferably at least one selected from the group consisting of a cobalt compound, a nickel compound and a titanium compound.

The 1 to 3 substituted aromatic compound may be at least one selected from the group consisting of phenol derivatives, catechol derivatives, resorcin derivatives, hydroquinone derivatives, and 2 to 3 substituted aromatic alkenyl compounds. preferable.

Since the modified cis-1,4-polybutadiene according to the first aspect of the present invention has a polar functional group that interacts with silica particles in the molecule, the rubber composition using this has suppressed silica aggregation. It has excellent low loss properties and can be suitably used for tires. Further, the method for producing a modified cis-1,4-polybutadiene according to the second aspect of the present invention does not require separation after the production of cis-1,4-polybutadiene, and is simple and complicated. It is an excellent manufacturing method that is not required.

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

(1) Production of cis-1,4-polybutadiene Cis-1,4-polybutadiene is produced by polymerizing 1,3-butadiene in the presence of a polymerization catalyst containing a transition metal compound and an organoaluminum compound. Can do.

(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. Examples of the organoaluminum compound include halogen-containing alkylaluminum compounds and alkylaluminum compounds, which can be used alone or in combination. For example, as a catalyst system using a cobalt compound (hereinafter sometimes referred to as a cobalt-based catalyst composition), a catalyst system comprising a cobalt compound, a halogen-containing alkylaluminum compound and water, or a cobalt compound, a halogen-containing alkylaluminum compound, A catalyst system comprising water and an alkylaluminum compound can be preferably used.

As the cobalt compound in the cobalt-based catalyst composition, a salt or complex of cobalt is preferably used, and particularly preferable are cobalt chloride, cobalt bromide, cobalt nitrate, cobalt 2-ethylhexanoate (cobalt octoate), and naphthenic acid. Cobalt salts such as cobalt, 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 complexes, pyridine complexes and picoline complexes, and cobalt complexes such as ethyl alcohol complexes.

The halogen-containing alkylaluminum compound in the cobalt-based catalyst composition includes 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 1 to It is a number represented by 2). Examples include dialkylaluminum halides such as dialkylaluminum chloride and dialkylaluminum bromide; alkylaluminum sesquihalides such as alkylaluminum sesquichloride and alkylaluminum sesquibromide; 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.

The alkylaluminum compound in the cobalt-based catalyst composition is preferably a compound represented by R ² ₃ Al (wherein R ² represents a hydrocarbon group having 1 to 10 carbon atoms). 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 ′) O—) _n (wherein R ′ is a carbon atom having 1 to 10 carbon atoms). A chain aluminoxane represented by a hydrogen group and partially substituted with a halogen atom and / or an alkoxy group, wherein n is the degree of polymerization and is 5 or more, preferably 10 or more, or a cyclic aluminoxane. Can be mentioned. Preferable R ′ includes a methyl group, an ethyl group, a propyl group, and an isobutyl group, and a methyl group and an ethyl group are particularly preferable. 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)
For example, the polymerization of 1,3-butadiene is performed 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 an 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).

As the order of addition of the catalyst components, it is preferable to add water in an inert solvent and mix uniformly, add an organoaluminum compound, add a cobalt compound, and start polymerization. After adding the 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.

As a polymerization catalyst, a cobalt compound, when using a halogen-containing alkyl aluminum compound and cobalt catalyst composition consisting of water, for cobalt compound, 1 relative to 1,3 mole butadiene × 10 -7 ^{~ 1} × 10 ^- A range of ³ moles is preferred. The halogen-containing alkylaluminum compound is preferably in the range of 1 × 10 ⁻⁵ to 1 × 10 ⁻¹ mol with respect to 1 mol of 1,3-butadiene. The water is preferably in the range of 1 × 10 ⁻⁵ to 1 × 10 ⁻¹ mol per 1 mol of 1,3-butadiene.

The addition amount of the halogen-containing alkylaluminum compound used in the cobalt-based catalyst composition is preferably 0.9 to 3.0 times, more preferably 1.0 to 2.0 times the amount of water to be added. . If it is larger than this range, the desired physical properties cannot be obtained, and if it is smaller than this range, the workability tends to deteriorate. The addition amount of the halogen-containing alkylaluminum 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 butane, pentane, hexane and heptane, alicyclic hydrocarbons such as cyclopentane and cyclohexane, 1-butene, cis- Examples include olefinic hydrocarbons such as C4 fraction such as 2-butene and trans-2-butene, hydrocarbon solvents such as mineral spirit, solvent naphtha, and kerosene, and halogenated hydrocarbon solvents such as methylene chloride. . Further, 1,3-butadiene itself may be used as a polymerization solvent.

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

As the molecular weight regulator, known at the time of polymerization, 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 0.5 to 40 mmol, more preferably 1 to 10 mmol, particularly preferably 1 to 7 mmol per mole of 1,3-butadiene. If an amount outside this range is used, the processability of the polymer tends to deteriorate.

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, more preferably 10 minutes to 6 hours, and particularly preferably 15 minutes to 1 hour.

(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, more preferably 20 to 70. If the Mooney viscosity is greater than the above range, processing is difficult, and if it is less than the above range, wear resistance and low loss tend to be reduced.

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

(2) Modification of cis-1,4-polybutadiene The modified cis-1,4-polybutadiene according to an embodiment of the present invention includes a cis-1,4-polybutadiene and a modifier in the presence of a Lewis acid and an organic halogen compound. It can be produced by reacting with a 1 to 3 substituted aromatic compound represented by the following general formula (1).

(Modifier)
Specific examples of the modifying agent represented by the general formula (1) 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-trimethoxy Benzene, 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-dimethoxy Phenol, catechol, 3-methoxycatechol, resorcinol, 2-methoxyresorcinol, 5-ethoxyresorcinol, hydroquinone, hydroquinone monomethyl ether, anethole, safrole, isosafrole, eugenol, methyleugenol, isoeugenol, methylisoeugenol, pyrogallol, pyrogallol trimethyl Examples include ether, phloroglucinol, and phloroglucinol trimethyl ether. Among these, it is preferable to use one or more modifiers selected from the group consisting of phenol derivatives, catechol derivatives, resorcin derivatives, hydroquinone derivatives, and 2- to 3-substituted aromatic alkenyl compounds, and phenol derivatives and catechol derivatives. Resorcin derivatives are preferred, and anisole, phenetole, anethole, veratrol, 1,3-dimethoxybenzene, 1,3-diethoxybenzene, 1,2-methylenedioxybenzene, safrole, isosafrole, and methylisoeugenol are particularly 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, An element such as Cd, Sn, Sb, Te, Hf, Ta, W, Hg, Bi, U, or a halide or organic halide of an oxygen-element conjugate such as PO, SeO, SO, SO ₂ , or VO; or These complexes are exemplified. 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 , Sb (OTf) ₃ Bi (OTf) ₃ , and Ga (OTf) ₃ . Among these, aluminum halides or aluminum organic halides are preferable.
In this embodiment, an organoaluminum compound can be used as the Lewis acid in the modification reaction. Therefore, the organoaluminum compound used in the polymerization of 1,3-butadiene can be continuously used as a Lewis acid. The use of the organoaluminum compound used in the polymerization of 1,3-butadiene as the Lewis acid is preferred because it is not necessary to add a new Lewis acid during the modification reaction. In the present embodiment, for example, it is preferable to use the same halogen-containing alkylaluminum compound used for the cobalt-based catalyst composition. The organoaluminum compound can also be added separately as a Lewis acid during the modification reaction.

(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. .

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 to 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 embodiment, a tertiary alkyl halide, particularly a tertiary alkyl halide having 4 to 12 carbon atoms, is preferred in view of the stability of the carbocation to be produced. Specifically, t-butyl chloride and t-Butyl bromide is preferred.

Further, as the organic halogen compound used in the modification reaction, an acyl halide compound represented by the following general formula (3) can be used.

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 may be carried out after the termination of the polymerization of 1,3-butadiene, after the polymerization, or after removing the solvent and unreacted monomers remaining in the reaction product. Alternatively, the polymer may be dried by a steam stripping method or a vacuum drying method and then dissolved again in a solvent such as cyclohexane. 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.

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 preferably 20 to 100 ° C, more preferably 40 to 100 ° C, and still more preferably 50 to 90 ° 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 preferably 1 to 600 minutes. More preferably, it is desirable to stir and mix for 10 to 90 minutes.

The amount of the modifier is preferably 1 × 10 ⁻³ to 100 mol, particularly 1 × 10 ⁻² to 10 mol, per 1 mol of 1,3-butadiene unit in cis-1,4-polybutadiene. preferable. Further, the amount of the organic halogen compound is 0.05 to 50 times, preferably 1 to 20 times that of the organoaluminum compound in 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 this embodiment 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 indicates 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 shows 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 the UV / RI value of a polymer 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 the UV / RI value of the polymer modified by reacting the polymerization terminal with 3,5-dimethoxybenzyl bromide is changed into five different types. 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 UV / RI value of Li-BR (modified) 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.

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

The degree of modification of the cis-1,4-polybutadiene of the present embodiment determined as described above 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.

(3) Production of rubber composition The modified cis-1,4-polybutadiene of this embodiment is blended alone or blended with other synthetic rubber or natural rubber, and if necessary, is oil-extended with process oil, Subsequently, a rubber composition can be obtained by adding a filler (filler) such as carbon black or silica, a silane coupling agent, a vulcanizing agent, a vulcanization accelerator, and other ordinary compounding agents and vulcanizing.

(Other synthetic rubber)
As the other synthetic rubber contained in the rubber composition, a vulcanizable rubber is preferable. Specifically, ethylene propylene diene rubber (EPDM), nitrile rubber (NBR), butyl rubber (IIR), chloroprene rubber (CR), Examples thereof include polyisoprene, high cis polybutadiene rubber, low cis polybutadiene rubber (BR), styrene-butadiene rubber (SBR), butyl rubber, chlorinated butyl rubber, brominated butyl rubber, and acrylonitrile-butadiene rubber. Among these, SBR is preferable. Further, among SBR, solution-polymerized styrene butadiene copolymer rubber (S-SBR) is particularly preferable. These rubbers may be used alone or in combination of two or more.

The microstructure of the solution polymerized styrene butadiene copolymer rubber (S-SBR) has a styrene content of 15 to 35% by weight, preferably 17 to 30% by weight, and a vinyl bond content of the butadiene portion of 30 to 75%, preferably 32-72%. By using this S-SBR in an amount of 30 parts by weight or more and less than 90 parts by weight, preferably 50 to 80 parts by weight, based on 100 parts by weight of the rubber component, the above-described effects are exhibited. If the amount of S-SBR is small, the wet performance decreases, which is not preferable. On the other hand, if the amount is large, the wear resistance and low loss property deteriorate, which is not preferable. Such S-SBR is known, and for example, commercially available products such as Nippon Zeon Nipol and Asahi Kasei Asaprene can be used.

(Silane coupling agent)
The silane coupling agent used in the rubber composition is an organosilicon compound represented by the general formula R ⁷ _n SiR ⁸ _4-n , where R ⁷ is a vinyl group, acyl group, allyl group, allyloxy group, amino group. , an epoxy group, a mercapto group, a chloro group, an alkyl group, a phenyl group, hydrogen, a styryl group, a methacryl group, an acryl group, an organic group having 1 to 20 carbon atoms having a reactive group selected from the ureido group, R ⁸ Is a hydrolyzable group selected from a chloro group, an alkoxy group, an acetoxy group, an isopropenoxy group, an amino group and the like, and n represents an integer of 1 to 3.

Among the R ⁷ components of the silane coupling agent, those containing a vinyl group and / or a chloro group are preferable.

Specific commercially available silane coupling agents include, for example, the following, but are not limited to these. Bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3-triethoxysilylpropyl) disulfide, bis (2-triethoxysilylpropyl) tetrasulfide, bis (3 -Trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylpropyl) tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethoxysilane 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilane Ruethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxysilylpropyl Methacrylate monosulfide, vinyltrichlorosilane, methylvinyldichlorosilane, divinyldichlorosilane, dimethylvinylchlorosilane, chloromethyldimethylvinylsilane, methoxydimethylvinylsilane, trimethoxyvinylsilane, dimethyldivinylsilane, ethoxydimethylvinylsilane, diacetoxymethyldinylsilane, allyl Oxydimethylvinylsilane, diethoxymethylvinylsilane, bis (dimethyl) Amino) methylvinylsilane, phenylvinyldichlorosilane, triacetoxyvinylsilane, 3-chloropropylmethyldivinylsilane, diethoxydivinylsilane, methylisobutylketoximevinylsilane, dimethylisobutoxyvinylsilane, triethoxyvinylsilane, methylphenylvinylchlorosilane, methylphenylvinylsilane Dimethylisopentyloxyvinylsilane, 4-bromophenyldimethylvinylsilane, 3-aminophenoxydimethylvinylsilane, 4-aminophenoxydimethylvinylsilane, dimethylpiperidinomethylvinylsilane, dimethyl-2-[(2-ethoxyethoxy) ethoxy] vinylsilane, Divinylmethylphenoxysilane, dimethyl-P-anisylvinylsilane, tris (1-methyl Vinyloxy) vinylsilane, triisopropoxyvinylsilane, diethoxy-2-piperidinoethoxyvinylsilane, diphenylvinylchlorosilane, 3-dimethylvinylphenyl-N, N-diethylcarbomate, triphenoxyvinylsilane, 1,3-divinyl-1,1 , 3,3-tetramethyldisiloxane, 1,3-divinyl-1,1,3,3-tetramethyldisilazane, 1- (4-methylpiperidinomethyl) -1,1,3,3-tetra Methyl-3-vinyldisiloxane, 1,4-bis (dimethylvinylsilyl) benzene, 1,4-bis (dimethylvinylsiloxy) benzene, 1,3-bis (dimethylvinylsiloxy) benzene, 1,1,3 3-tetraphenyl-3-divinyldisiloxane, 1,3,5-trimethyl-1,3,5- Rivinylcyclotrisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, tetrakis (dimethylvinylsiloxymethyl) methane, 3-chloropropyltrimethoxysilane .

The addition amount of the silane coupling agent is preferably 0.2 to 20% and particularly preferably 5 to 15% with respect to the filler amount. If it is less than the above range, it is not preferable because it causes scorch. Moreover, since it will become the cause of a deterioration of a tensile characteristic and elongation when it exceeds more than said range, it is unpreferable.

(4) Production of rubber-modified impact-resistant polystyrene-based resin composition The modified cis-1,4-polybutadiene of this embodiment is used as a modifier for plastics, for example, impact-resistant polystyrene. A modified impact-resistant polystyrene resin composition can also be produced.

As a method for producing the above rubber-modified impact-resistant polystyrene resin composition, a method of polymerizing a styrene monomer in the presence of the modified cis-1,4-polybutadiene of the present embodiment is adopted. Bulk suspension polymerization is an economically advantageous method. As the styrene monomer, for example, styrene, alkyl-substituted styrene such as α-methyl styrene and p-methyl styrene, and halogen-substituted styrene such as chlorostyrene are conventionally known for producing rubber-modified impact-resistant polystyrene resin compositions. One kind or a mixture of two or more kinds of styrenic monomers are used. Of these, styrene is preferred.

In addition to the above-mentioned modified cis-1,4-polybutadiene at the time of production, the modified cis-1,4-polybutadiene, styrene-butadiene copolymer, ethylene-propylene polymer, ethylene-vinyl acetate polymer, acrylic rubber, etc. It can be used in combination within 50% by weight based on 4-polybutadiene. Moreover, you may blend the resin manufactured by these methods. Furthermore, you may manufacture by mixing the polystyrene-type resin which does not contain resin manufactured by these methods. As an example of the above bulk polymerization method, a modified cis-1,4-polybutadiene (1 to 25% by weight) is dissolved in a styrene monomer (99 to 75% by weight). Then, a polymerization initiator or the like is added to convert into particles in which the modified cis-1,4-polybutadiene is dispersed to a styrene monomer conversion rate of 10 to 40%. Until the rubber particles are produced, the rubber phase forms a continuous phase. Further, the polymerization is continued until the conversion into a dispersed phase as a rubber particle (particle formation process), and the polymerization is carried out to a conversion rate of 50 to 99% to produce a rubber-modified impact-resistant polystyrene resin composition.

The dispersed particles (rubber particles) of modified cis-1,4-polybutadiene are particles dispersed in a resin, and are composed of modified cis-1,4-polybutadiene and a polystyrene resin. The polystyrene resin is a modified cis-1,4-polybutadiene. It is occluded with 4-polybutadiene grafted or not grafted. In this embodiment, the modified cis-1,4-polybutadiene having a dispersed particle diameter in the range of 0.5 to 7.0 μm, preferably in the range of 1.0 to 3.0 μm, can be suitably produced.

A graft ratio in the range of 150 to 350 can be preferably produced. It may be a batch type or a continuous production method and is not particularly limited.

The raw material solution mainly composed of the styrene monomer and the modified cis-1,4-polybutadiene is polymerized in a complete mixing type reactor. However, in the complete mixing type reactor, the raw material solution is uniformly mixed in the reactor. What is necessary is just to maintain a state, As a preferable thing, a stirring blade of types, such as a helical ribbon, a double helical ribbon, an anchor, is mentioned. It is preferable that a draft tube is attached to the helical ribbon type stirring blade to further enhance the vertical circulation in the reactor.

The rubber-modified impact-resistant polystyrene-based resin composition includes a stabilizer such as an antioxidant and an ultraviolet absorber, a release agent, a lubricant, a colorant, various fillers, and various fillers as necessary at the time of production and after production. Known additives such as plasticizers, higher fatty acids, organic polysiloxanes, silicone oils, flame retardants, antistatic agents and foaming agents may be added.

The rubber composition obtained from the modified cis-1,4-polybutadiene of this embodiment includes industrial articles such as tires, vibration-insulating rubbers, belts, hoses, seismic isolation rubbers, footwear such as men's shoes, women's shoes, and sports shoes. Used for various rubber applications. In that case, the rubber component is preferably blended so as to contain at least 10% by weight of the modified cis-1,4-polybutadiene of the present embodiment. In addition, the rubber-modified impact-resistant polystyrene resin composition can be used in various known molded products, but has excellent flame retardancy, impact strength, and tensile strength, so that it can be used in electrical and industrial applications, packaging materials, and housing. Suitable for related materials, OA equipment materials, tools, daily necessities, etc. For example, it can be used in a wide range of applications such as housings for televisions, personal computers, air conditioners, exterior materials for office equipment such as copiers and printers, and food containers for frozen foods, lactic acid beverages, and ice creams.

(Evaluation methods)
Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. The Mooney viscosity, toluene solution viscosity, number average molecular weight, processability, rebound resilience of the vulcanized product, tan δ of the vulcanized product, and permanent set in the examples were measured by the following methods.

Mooney viscosity (ML _{1 + 4} , 100 ° C.): In accordance with JIS-K6300, pre-heated at 100 ° C. for 1 minute using a Mooney viscometer (SMV-300) manufactured by Shimadzu Corporation, and measured for 4 minutes. Expressed as Mooney viscosity (ML _{1 + 4} , 100 ° C.).

Toluene solution viscosity (Tcp): After 2.28 g of polymer was dissolved in 50 ml of toluene, a standard solution for viscometer calibration (JIS Z8809) was used as a standard solution. 400 was used and measured at 25 ° C.

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.

Processability: Evaluated by Mooney viscosity of unvulcanized product. The prototype 2 or 3 was displayed as an index, and the value was converted so that the larger the index, the better.

Rebound resilience of the vulcanizate: According to BS903, the rebound resilience was measured at room temperature using a Dunlop trypometer, and the prototype 2 or 3 was displayed as an index. The larger the index, the better the low loss property.

Strain dependency of storage elastic modulus (G ′) (Pain effect): Dynamic strain analysis was performed under the conditions of a frequency of 120 ° C. and 1 Hz using a rubber processability analyzer RPA-2000 manufactured by Alpha Technology. For the Payne effect, the ratio of G 'when strain is 45% and G' when strain is 0.5% (G'45 _% / _G'0.5% ) is displayed as an index with prototype 2 or 3 as 100. . It shows that the dispersibility of a reinforcing agent is so favorable that an index | exponent is large.

Vulcanized tan δ: Measured under conditions of temperature 50 ° C., frequency 10 Hz, dynamic strain 0.3% using EBO LEXOR 100N manufactured by GABO, and the index is shown with prototype 2 or 3 as 100, the index being large It converted so that it might become so favorable.

Heat generation amount / permanent strain: Measured according to the measurement method stipulated in JIS K6265, displayed as an index with prototype 2 or 3 as 100, and converted so that the larger the index, the better.

(Example 1)
In a 1.5 liter stainless steel autoclave with sufficient nitrogen substitution inside, 600 mL of a cyclohexane-C4 fraction mixed solution containing 32.4% by weight of 1,3-butadiene (26.4% by weight of cyclohexane, cis-2) -39.2% by weight of C4 fraction containing butene as the main component), and then stirred by adding 1.3 mmol of water and 1.9 mmol of diethylaluminum monochloride, and adding 5.1 mmol of cyclooctadiene did. After the temperature of the autoclave was raised and the internal temperature reached 60 ° C., 0.005 mmol of cobalt octoate was added, and a polymerization reaction was performed at 60 ° C. for 25 minutes. After the polymerization reaction, 430 mmol of a modifier 1,3-dimethoxybenzene (DMOB) was added, and the temperature of the autoclave was increased. After the internal temperature reached 70 ° C., 3.8 mmol of t-butyl chloride was added and reacted for 60 minutes. Antiaging agent was added there and it vacuum-dried at 80 degreeC for 3 hours. The degree of modification of the resulting modified cis-1,4-polybutadiene was 0.35. Table 1 shows the physical properties of the resulting modified cis-1,4-polybutadiene.

(Example 2)
In a 1.5 liter stainless steel autoclave with sufficient nitrogen substitution inside, 500 mL of cyclohexane-C4 fraction mixed solution containing 30.3% by weight of 1,3-butadiene (37.3% by weight of cyclohexane, cis-2) -C4 fraction containing butene as the main component (containing 31.2% by weight)), and then stirred by adding 1.1 mmol of water and 1.6 mmol of diethylaluminum monochloride, 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, 9.1 mmol of a modifier 1,3-dimethoxybenzene (DMOB) was added, and the autoclave was heated to an internal temperature of 70 ° C. Then, 15.8 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 modified cis-1,4-polybutadiene.

(Example 3)
In a 1.5 liter stainless steel autoclave with sufficient nitrogen substitution inside, 500 mL of cyclohexane-C4 fraction mixed solution containing 30.3% by weight of 1,3-butadiene (37.3% by weight of cyclohexane, cis-2) -31.2% by weight of C4 fraction containing butene as the main component), then add 1.1 mmol of water and 1.6 mmol of diethylaluminum monochloride, stir, and add 4.5 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, 9.0 mmol of a modifier 1,3-dimethoxybenzene (DMOB) was added, and the temperature was raised to 80 ° C. Next, 3.3 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 modified cis-1,4-polybutadiene.

Example 4
The reaction was conducted in the same manner as in Example 3 except that 1,3-diethoxybenzene (DEOB) was used as the modifier. Table 1 shows the physical properties of the resulting modified cis-1,4-polybutadiene.

(Example 5)
In a 1.5 liter stainless steel autoclave with sufficient nitrogen substitution inside, 500 mL of cyclohexane-C4 fraction mixed solution containing 30.3% by weight of 1,3-butadiene (37.3% by weight of cyclohexane, cis-2) -C4 fraction containing butene as the main component (containing 31.2% by weight)), and then stirred by adding 1.1 mmol of water and 1.6 mmol of diethylaluminum monochloride, 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, 9.2 mmol of the modifier veratrol was added, and the temperature was raised to 70 ° C. Next, 31.3 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 modified cis-1,4-polybutadiene.

(Example 6)
The reaction was conducted in the same manner as in Example 3 except that 1,2-methylenedioxybenzene (MDB) was used as the modifier. Table 1 shows the physical properties of the resulting modified cis-1,4-polybutadiene.

(Example 7)
In a 1.5 liter stainless steel autoclave with sufficient nitrogen substitution inside, 500 mL of cyclohexane-C4 fraction mixed solution containing 30.3% by weight of 1,3-butadiene (37.3% by weight of cyclohexane, cis-2) -31.2% by weight of C4 fraction containing butene as the main component), then add 1.1 mmol of water and 1.6 mmol of diethylaluminum monochloride, stir, and add 4.5 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, 9.3 mmol of the modifier anisole was added, and the temperature was raised to 70 ° C. Next, 3.3 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 modified cis-1,4-polybutadiene.

(Example 8)
The reaction was performed in the same manner as in Example 7 except that the denaturant was phenetole. Table 1 shows the physical properties of the resulting modified cis-1,4-polybutadiene.

Example 9
In a 1.5 liter stainless steel autoclave with sufficient nitrogen substitution inside, 500 mL of cyclohexane-C4 fraction mixed solution containing 30.3% by weight of 1,3-butadiene (37.3% by weight of cyclohexane, cis-2) -31.2% by weight of C4 fraction containing butene as the main component), then add 1.1 mmol of water and 1.6 mmol of diethylaluminum monochloride, stir, and add 4.5 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, 9.3 mmol of the modifier anethole was added, and the temperature was raised to 70 ° C. Subsequently, 7.9 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 modified cis-1,4-polybutadiene.

(Example 10)
The reaction was performed in the same manner as in Example 3 except that the modifier was safrole. Table 1 shows the physical properties of the resulting modified cis-1,4-polybutadiene.

(Example 11)
In a 1.5 liter stainless steel autoclave with sufficient nitrogen substitution inside, 500 mL of cyclohexane-C4 fraction mixed solution containing 30.3% by weight of 1,3-butadiene (37.3% by weight of cyclohexane, cis-2) -31.2% by weight of C4 fraction containing butene as the main component), then add 1.1 mmol of water and 1.6 mmol of diethylaluminum monochloride, stir, and add 4.5 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, 9.0 mmol of a modifier isosafrole was added, and the temperature was raised to 70 ° C. Next, 3.3 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 modified cis-1,4-polybutadiene.

Example 12
In a 1.5 liter stainless steel autoclave with sufficient nitrogen substitution, 600 mL of a cyclohexane-C4 fraction mixed solution containing 30.6% by weight of 1,3-butadiene (36.8% by weight of cyclohexane, cis-2) -Containing 31.1% by weight of 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 4.5 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, 18 mmol of a modifier 1,2-methylenedioxybenzene (MDB) was added, and the temperature was raised to 80 ° C. Next, 3.3 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 modified cis-1,4-polybutadiene.

(Example 13)
In a 1.5 liter stainless steel autoclave with sufficient nitrogen substitution, 600 mL of a cyclohexane-C4 fraction mixed solution containing 30.6% by weight of 1,3-butadiene (36.8% by weight of cyclohexane, cis-2) -Containing 31.1% by weight of 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 4.5 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, 9.0 mmol of a modifier isosafrole was added, and the temperature was raised to 80 ° C. Next, 3.3 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 modified cis-1,4-polybutadiene.

(Comparative Example 1)
In a 1.5 liter stainless steel autoclave with sufficient nitrogen substitution inside, 600 mL of a cyclohexane-C4 fraction mixed solution containing 32.4% by weight of 1,3-butadiene (26.4% by weight of cyclohexane, cis-2) -Containing 39.2% by weight of C4 fraction containing butene as the main component), then adding 1.3 mmol of water and 1.9 mmol of diethylaluminum monochloride, stirring, and adding 5.3 mmol of cyclooctadiene did. After the temperature of the autoclave was raised and the internal temperature reached 60 ° C., 0.005 mmol of cobalt octoate was added, and a polymerization reaction was performed at 60 ° C. for 25 minutes. After adding the anti-aging agent, the polymer was precipitated with ethanol and vacuum dried at 80 ° C. for 3 hours. The physical properties of the resulting cis-1,4-polybutadiene are shown in Table 1.

(Comparative Example 2)
In a 1.5 liter stainless steel autoclave with sufficient nitrogen substitution, 600 mL of a cyclohexane-C4 fraction mixed solution containing 30.6% by weight of 1,3-butadiene (36.8% by weight of cyclohexane, cis-2) -Containing 31.1% by weight of C4 fraction containing butene as the main component), then adding 1.3 mmol of water and 1.9 mmol of diethylaluminum monochloride, stirring, and adding 5.3 mmol of cyclooctadiene did. After the temperature of the autoclave was raised and the internal temperature reached 60 ° C., 0.005 mmol of cobalt octoate was added, and a polymerization reaction was performed at 60 ° C. for 25 minutes. After adding the anti-aging agent, the polymer was precipitated with ethanol and vacuum dried at 80 ° C. for 3 hours. The physical properties of the resulting cis-1,4-polybutadiene are shown in Table 1.

(Prototype 1)
Using the modified cis-1,4-polybutadiene obtained in Example 1 and kneading with SBR, silica, etc. by a 250 cc lab plast mill according to the formulation shown in Table 2, the vulcanizing agent and vulcanizing aid are opened. Mixed by roll. Subsequently, press vulcanization was performed at a temperature of 160 ° C., and physical properties of the obtained vulcanized test piece were evaluated. The results are shown in Table 3.

(Prototype 2)
Except for using the cis-1,4-polybutadiene obtained in Comparative Example 1, the compounding and processing were performed in the same manner as in Prototype 1, and the physical properties were evaluated. The results are shown in Table 3.

Details of the compounds used in the blending are as follows.
SBR: 23% styrene content, ML _{1 + 4} (100 ° C.) 70
Silica: Tosoh Silica Co., Ltd., trade name: Nip seal AQ
Silane coupling agent: Evonik, product name Si69
Oil: San Petroleum (SUNOCO), Sansen Oil 4240
Zinc oxide: Sakai Chemical Industry Sazex No. 1 stearic acid: Kao stearate anti-aging agent: Sumitomo Chemical Antigen 6C
Sulfur: Vulcanization accelerator manufactured by Hosoi Chemical Industry Co., Ltd. 1: Noxeller CZ manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.
Vulcanization accelerator 2: NOCELLER D manufactured by Ouchi Shinsei Chemical Co., Ltd.

Table 3 shows the evaluation results of the obtained blend. Each evaluation item of prototype 2 was defined as 100 and compared with prototype 1. For each item, the larger the value, the better the characteristics.

(Prototype 3)
The cis-1,4-polybutadiene obtained in Comparative Example 2 was used and kneaded with SBR, silica, etc. by a 250 cc lab plast mill according to the formulation shown in Table 4, and then the vulcanizing agent and vulcanizing aid were opened rolls. Mixed with. Subsequently, press vulcanization was performed at a temperature of 160 ° C., and physical properties of the obtained vulcanized test piece were evaluated. The results are shown in Table 5.

(Prototype 4)
Except that the modified cis-1,4-polybutadiene obtained in Example 12 was used, the compounding and processing were performed in the same manner as in prototype 3, and the physical properties were evaluated. The results are shown in Table 3.

(Prototype 5)
Except for using the modified cis-1,4-polybutadiene obtained in Example 13, the compounding and processing were performed in the same manner as in Prototype 3, and the physical properties were evaluated. The results are shown in Table 5.

Details of the compounds used in the blending are as follows.
SBR: 23% styrene content, ML _{1 + 4} (100 ° C.) 70
Silica: Product name made by Evonik, Ultrasil 7000GR
Silane coupling agent: Evonik Degussa, trade name Si75
Oil: Alternative aroma oil Zinc oxide: Sakai Chemical Industry Sazex No. 1 Stearic acid: Kao Stearic acid anti-aging agent: Sumitomo Chemical Antigen 6C
Sulfur: Vulcanization accelerator manufactured by Hosoi Chemical Industry Co., Ltd. 1: Noxeller CZ manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.
Vulcanization accelerator 2: NOCELLER D manufactured by Ouchi Shinsei Chemical Co., Ltd.

Table 5 shows the evaluation results of the obtained blend. Each evaluation item of prototype 3 was defined as 100 and compared with prototypes 4 and 5. For each item, the larger the value, the better the characteristics.

Claims

A modification obtained by reacting cis-1,4-polybutadiene with a 1 to 3 substituted aromatic compound represented by the following general formula (1) in the presence of a Lewis acid and an organic halogen compound Cis-1,4-polybutadiene.

In the 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 each represent hydrogen, a hydroxyl group, an alkyl group or an alkoxy group having 1 to 10 carbon atoms. .
The 1 to 3 substituted aromatic compound is at least one selected from the group consisting of phenol derivatives, catechol derivatives, resorcin derivatives, hydroquinone derivatives, and 2 to 3 substituted aromatic alkenyl compounds. The modified cis-1,4-polybutadiene according to claim 1.
3. The modified cis-1,4-polybutadiene according to claim 1, wherein the Lewis acid is an organoaluminum compound.
The modified cis-1,4-polybutadiene according to any one of claims 1 to 3, wherein the organic halogen compound is a tertiary alkyl halide having 4 to 12 carbon atoms.
1,3-butadiene is polymerized using 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 to 3 substituted aromatic compound represented by 1) is added, and in the presence of Lewis acid and the organic halogen compound, the cis-1,4-polybutadiene and 1 represented by the following general formula (1) A process for producing a modified cis-1,4-polybutadiene, which comprises reacting with a 3-substituted aromatic compound.

In the 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 each represent hydrogen, a hydroxyl group, an alkyl group or an alkoxy group having 1 to 10 carbon atoms. .
6. The method for producing a modified cis-1,4-polybutadiene according to claim 5, wherein the transition metal compound is at least one selected from the group consisting of a cobalt compound, a nickel compound and a titanium compound.
The 1 to 3 substituted aromatic compound is at least one selected from the group consisting of phenol derivatives, catechol derivatives, resorcin derivatives, hydroquinone derivatives, and 2 to 3 substituted aromatic alkenyl compounds. A process for producing the modified cis-1,4-polybutadiene according to claim 6.