JP2019065102A - Modifier for olefin polymer, modified olefin polymer, method for producing the same, and rubber composition - Google Patents

Abstract

The present invention provides a modifier for an olefin polymer which improves fuel economy (low heat buildup) and abrasion resistance, a modified olefin polymer, a method for producing the same, and a rubber composition.
A modifier for an olefin polymer is characterized by containing a benzimidazole compound represented by the general formula (A). Creation of a new terminal modified polymer for tires that can be used mainly for base treads, sidewalls, etc., and a new modifier that improves the low fuel consumption (low heat buildup) and abrasion resistance, which are the key It is.
【Selection chart】 None

Description

  The present invention relates to a modifier for an olefin polymer, a modified olefin polymer, a method for producing the same, and a rubber composition, and in particular, a benzimidazole having high affinity to carbon black used as a filler of a tire. The present invention relates to a novel modifier for an olefin-based polymer containing a compound, a modified olefin-based polymer produced using the same, a method for producing the same, and a rubber composition containing the modified olefin-based polymer.

  In recent years, with the increasing concern for environmental and resource issues, the demand for low fuel consumption of automobiles has increased. Generally, in order to produce a tire excellent in low fuel consumption, it is said that use of a rubber composition which is excellent in low heat buildup and can form a rubber cross-linked product which hardly generates heat during traveling is effective. There is. As a polymer used for such a rubber composition, for example, an end-modified polymer has the effect of suppressing wasteful movement by binding or interacting the polymer end with the filler, and suppressing unnecessary heat generation, and further, the filler It is said to be effective because it has the effect of improving the dispersibility of

  There are various known terminal modifiers used for producing such terminal modified polymers, depending on the filler used. As a filler generally used for tires, such as a car, silica and carbon black are mentioned. For example, when silica is used as a filler, a modifier of a type capable of chemically bonding a modified polymer end to a silanol group on the silica surface is being actively studied (for example, Patent Documents 1 and 2) ). Moreover, when using carbon black as a filler, terminal modifiers, such as a tin compound, a dialkyl amino benzophenone type | system | group, N-alkyl lactam type | system | group, etc., are known so far, for example (for example, patent documents 3 and 4).

International Publication No. 2012/070625 WO 2000/053671 JP, 2009-7455, A JP, 2017-39877, A

  However, with regard to terminal modifiers when carbon black is used as a filler, there have been few reported cases in recent years, and development of new modifiers for improving fuel economy, abrasion resistance, etc., which has attracted particular attention recently, is expected It is done.

  The present invention has been made in view of the above problems, and is a modifier for an olefin polymer, a modified olefin polymer, a method for producing the same, and a rubber composition for improving low fuel consumption (low heat buildup) and wear resistance. Intended to provide.

  The inventors of the present invention conducted intensive studies to achieve the above objects, and as a result, it is possible to reduce fuel consumption (low heat buildup) or to use an olefin polymer modifier containing a benzimidazole compound represented by a specific chemical formula. The inventors have found that a modified olefin-based polymer and a rubber composition having improved abrasion resistance can be obtained, resulting in the present invention.

That is, the present invention is as follows.
[1] A modifier for an olefin polymer comprising a benzimidazole compound represented by the following general formula (A).

（一般式（Ａ）中、Ｒ^１は、芳香環上の任意の炭素の置換基を表し、水素原子、ハロゲン原子、フッ素原子で置換されていてもよい炭素数１〜６のアルキル基、フッ素原子で置換されていてもよい炭素数１〜６のアルキルオキシ基、フッ素原子で置換されていてもよい炭素数１〜６のジアルキルアミノ基、炭素数１〜６のトリアルキルシリル基、炭素数１〜６のジ［トリ（アルキル）シリル］アミノ基、ニトロ基、及び水酸基のいずれかであり、ｎは、０〜４の整数である。ここで、ｎが２以上の場合、Ｒ^１は、それぞれ同一であっても、異なっていてもよい。
Ｒ^２は、窒素上の置換基を表し、水素原子、フッ素原子で置換されていてもよい炭素数１〜６のアルキル基、及び炭素数１〜６のトリアルキルシリル基のいずれかである。
Ｇは、反応性基を表し、フッ素原子で置換されていてもよい炭素数１〜６のアルキル基を有するカルボン酸アルキルエステル基、フッ素原子で置換されていてもよい炭素数１〜６のアルキルケトン基、フッ素原子で置換されていてもよい炭素数１〜６のアルキルチオケトン基、及びシアノ基のいずれかである。
Ｌは、２価の連結基を表し、フッ素原子で置換されていてもよい炭素数１〜１２のアルキレン基；酸素原子、硫黄原子及びジメチルシリレン基からなる群より選ばれる基を主鎖中に一つ以上含有する炭素数１〜１２のヘテロ含有アルキレン基；ビニレン基；並びにエチニレン基のいずれかである。
但し、一般式（Ａ）で表されるベンズイミダゾール化合物の分子量は１０００を超えない。）

(In the general formula (A), R ¹ represents a substituent of any carbon on the aromatic ring, and is a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a fluorine atom, fluorine A C1-C6 alkyloxy group which may be substituted by an atom, a C1-C6 dialkylamino group which may be substituted by a fluorine atom, a C1-C6 trialkylsilyl group, a carbon number Is any one of 1 to 6 di [tri (alkyl) silyl] amino group, nitro group, and hydroxyl group, n is an integer of 0 to 4. Here, when n is 2 or more, R ¹ is And each may be the same or different.
R ² represents a substituent on nitrogen, and is any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a fluorine atom, and a trialkylsilyl group having 1 to 6 carbon atoms.
G represents a reactive group, and is a carboxylic acid alkyl ester group having an alkyl group of 1 to 6 carbon atoms which may be substituted by a fluorine atom, or an alkyl of 1 to 6 carbon atoms which may be substituted by a fluorine atom It is any of a ketone group, a C1-C6 alkylthio ketone group which may be substituted by a fluorine atom, and a cyano group.
L represents a divalent linking group, and in the main chain, a group selected from the group consisting of an alkylene group having 1 to 12 carbon atoms which may be substituted with a fluorine atom; an oxygen atom, a sulfur atom and a dimethylsilylene group One or more hetero-containing alkylene groups having 1 to 12 carbon atoms; vinylene group; and ethynylene group.
However, the molecular weight of the benzimidazole compound represented by the general formula (A) does not exceed 1000. )

[2] A modifier for an olefin polymer, comprising a benzimidazole compound represented by the following general formula (A1).

（一般式（Ａ１）中、Ｌ及びＧは、前記一般式（Ａ）に記載のＬ及びＧと同義である。）

(In the general formula (A1), L and G have the same meanings as L and G described in the general formula (A).)

[3] Any one of C 1 to C 6 alkyl ketone groups which may be substituted by a fluorine atom, G 1 to C 6 alkylthio ketone group which may be substituted by a fluorine atom, and cyano group And L is a group selected from the group consisting of an alkylene group having 1 to 12 carbon atoms which may be substituted with a fluorine atom; and an oxygen atom, a sulfur atom and a dimethylsilylene group in the main chain The modifier for an olefin polymer according to the above [1] or [2], which is any one of the above-described hetero-containing alkylene groups having 1 to 12 carbon atoms.

[4] The method according to any one of the above [1] to [3], which contains at least one organic solvent selected from the group consisting of toluene, xylene, n-hexane, n-heptane, cyclohexane and methylcyclohexane. Modifiers for olefin polymers.

[5] A modified olefin polymer produced using the modifier for an olefin polymer according to any one of the above [1] to [4].

[6] The modified olefin polymer according to the above [5], which is produced using at least one olefin monomer selected from the group consisting of butadiene, isoprene and styrene.

[7] A method for producing a modified olefin polymer, comprising using the modifier for an olefin polymer according to any one of the above [1] to [4].

[8] The method for producing a modified olefin polymer according to the above [7], wherein at least one olefin monomer selected from the group consisting of butadiene, isoprene and styrene is used as a raw material.

[9] A rubber composition comprising the modified olefin polymer according to the above [5] or [6] and carbon black.

  As described above, according to the present invention, it is possible to provide a modifying agent for an olefin polymer, a modified olefin polymer, a method for producing the same, and a rubber composition, which improve fuel economy (low heat buildup) and wear resistance. it can.

<Benzimidazole Compound: General Formula (A)>
The benzimidazole compound represented by the following general formula (A), which is used as an active component of the modifier for an olefin polymer of the present invention, will be described.

(Substituent: with respect to R ¹ and R ² )
In the benzimidazole compound represented by the general formula (A), R ¹ represents a substituent of any carbon on the aromatic ring. R ¹ represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a fluorine atom, an alkyloxy group having 1 to 6 carbon atoms which may be substituted with a fluorine atom, a fluorine atom C1-C6 dialkylamino group which may be substituted, C1-C6 trialkylsilyl group, C1-C6 di [tri (alkyl) silyl] amino group, nitro group, and hydroxyl group It is either.
n is the number and is an integer of 0 to 4; Here, when n is 2 or more, R ¹ may be identical to or different from each other. Also, the position of the substituent is not particularly limited.
R ² represents a substituent on nitrogen, and is any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a fluorine atom, and a trialkylsilyl group having 1 to 6 carbon atoms.

The “C1-C6 alkyl” in R ¹ and R ² means, for example, C1-C6 linear alkyl such as methyl and ethyl; C3-C3 such as isopropyl and t-butyl 6 branched alkyl; for example, cyclic alkyl having 3 to 6 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl and the like, and "the alkyl having 1 to 6 carbons which may be substituted with a fluorine atom" means the above-mentioned It represents that a part or all of the hydrogen atoms in "alkyl" may be substituted by a fluorine atom.

In the general formula (A), R ¹ is preferably a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may be substituted with a fluorine atom, and more preferably a hydrogen atom, a fluorine atom, trifluoro It is a methyl group, particularly preferably a hydrogen atom. Further, n is preferably 0 to 2, more preferably 0 (in the case of no substitution). In the general formula (A), R ² is preferably a hydrogen atom. Therefore, the benzimidazole compound contained in the more preferable modifier for olefin polymers of this invention is represented by the following general formula (A1).

(Reactive group: about G)
In the general formula (A) or the general formula (A1), G represents a reactive group, and is a carboxylic acid alkyl ester group having an alkyl group having 1 to 6 carbon atoms which may be substituted with a fluorine atom, a fluorine atom It is any of a C1-C6 alkyl ketone group which may be substituted, a C1-C6 alkyl thio ketone group which may be substituted by the fluorine atom, and a cyano group. Moreover, a C1-C6 alkyl ketone group and a C1-C6 alkylthio ketone group have a C1-C5 linear, branched or C3-C5 cyclic alkyl group. It represents a ketone group (> C = O) and a thioketone group (> C = S).

  In the general formula (A) or the general formula (A1), as G, an alkyl ketone group having 1 to 6 carbon atoms which may be substituted by a fluorine atom, or 1 to 1 carbon which may be substituted by a fluorine atom 6 is either an alkylthio ketone group or a cyano group.

In general formula (A) or general formula (A1), as G, an alkyl ketone group having 1 to 6 carbon atoms, a trifluoromethyl ketone group (CF ₃ -C (= O)-), and a carbon number of 1 to 4 are particularly preferable. And any one of an alkyl thio ketone group of 6, a trifluoromethyl thio ketone group (CF ₃ -C (= S)-), and a cyano group. The reactive group mentioned above is preferable from the viewpoint of the increase in the amount of carbon gel, the solubility in the reaction solvent, and the economy.

(Linking group: L)
In the general formula (A) or the general formula (A1), L represents a divalent linking group connecting a benzimidazole moiety and a reactive group G, and has 1 to 12 carbon atoms which may be substituted by a fluorine atom An alkylene group; one or more groups selected from the group consisting of an oxygen atom, a sulfur atom and a dimethylsilylene group in the main chain thereof, a hetero-containing alkylene group having 1 to 12 carbon atoms; a vinylene group; and an ethynylene group is there.

Examples of the alkylene group having 1 to 12 carbon atoms which may be substituted with a fluorine atom include linear groups having 1 to 12 carbon atoms such as ethylene group, propylene group, butylene group, hexylene group and decamethylene group. alkylene group; dimethylethylene group _{(-CH (CH 3) -CH (} CH 3) -), dimethylpropylene group _{(-CH (CH 3) -CH 2} -CH (CH 3) -) carbon atoms, such as 1 to 12 Branched alkylene groups having 1 to 12 carbon atoms such as cyclohexylene and cyclohexyl-1,4-dimethylene (-CH ₂ -C ₆ H ₁₀ -CH _2- ). Furthermore, hydrogen atoms in these alkylene groups may be substituted with fluorine atoms.

  In addition, a hetero-containing alkylene group having 1 to 12 carbon atoms in the main chain in which L contains at least one group selected from the group consisting of an oxygen atom, a sulfur atom and a dimethylsilylene group is, for example, an ether bond or a thioether It represents a C1-C12 divalent linear, branched or cyclic alkylene group having a bond or a dimethylsilylene bond in its main chain.

Furthermore, L may be a vinylene group (-CH ₂ = CH _2- ) having an unsaturated bond or an ethynylene group. In addition, hydrogen atoms in the vinylene group and the ethynylene group may be substituted by a fluorine atom.

  In the general formula (A) or the general formula (A1), as L, preferably an alkylene group having 1 to 12 carbon atoms which may be substituted with a fluorine atom; and an oxygen atom, a sulfur atom and a dimethylsilylene group Any one of C1 to C12 hetero-containing alkylene groups containing one or more selected groups in the main chain, particularly preferably a C2 to C12 linear or branched alkylene group; an ether bond And a bivalent linear alkylene group having 1 to 12 carbon atoms containing a thioether bond and a dimethylsilylene bond in the main chain. The linking group mentioned above is preferable from the viewpoint of solubility in a reaction solvent and economy.

  In the present invention, the molecular weight of the benzimidazole compound represented by the general formula (A) does not exceed 1000 from the viewpoint of solubility in a reaction solvent and economy.

<Modifier for olefin polymers>
Next, a terminal modifier containing the benzimidazole compound represented by the general formula (A) or the general formula (A1) of the present invention will be described. The modifier for an olefin polymer according to the present invention is dissolved or suspended in a powder, granules, solid or organic solvent containing the benzimidazole compound represented by the above general formula (A) or the above general formula (A1) as an active ingredient Represents a non-aqueous solution (homogeneous solution or slurry).

  When the modifier for an olefin polymer according to the present invention is produced in the form of powder (powder), granules, or solid, the method includes the benzimidazole compound represented by the general formula (A) or the general formula (A1) Is not particularly limited as long as it is a manufacturing method that can stably exist. Moreover, when manufacturing in solid form, the dosage form, such as a pellet, a tablet, etc. is not specifically limited, either. Moreover, you may use if it is an additive which does not inhibit the polymerization reaction of an olefin polymer using the modifier for olefin polymers of this invention.

  When the modifier for olefin polymers of the present invention is produced as an organic solution (in the form of solution), examples of the organic solvent to be used include aromatics having 6 to 18 carbon atoms such as benzene, toluene, and xylene (including isomers). Group solvents; halogen-containing aromatic solvents such as chlorobenzene and dichlorobenzene; and aliphatic solvents having 6 to 18 carbon atoms such as n-pentane, n-hexane, n-heptane, cyclohexane and methylcyclohexane. These organic solvents may be used alone or in combination of two or more. The organic solvent used for the modifier for an olefin polymer of the present invention is preferably at least one organic solvent selected from the group consisting of toluene, xylene, n-hexane, n-heptane, cyclohexane and methylcyclohexane.

  The amount of the organic solvent is not particularly limited as long as the benzimidazole compound represented by the general formula (A) or the general formula (A1) is suspended to such an extent that the dissolution or production is not hindered. As the amount of the organic solvent used for the modifier for olefin polymers of the present invention, the concentration relative to 1 mol of the total amount of the benzimidazole compound represented by the general formula (A) or the general formula (A1) is usually 0 0.01 to 5.0 mol / L, preferably 0.01 to 1.0 mol / L. If the concentration is higher than this concentration, there is no serious problem, but if the concentration is lower, the reaction vessel may need to be enlarged, and the above range is preferable from the viewpoint of economy and reactivity.

  When the modifier for an olefin polymer of the present invention is produced as an organic solution, for example, the benzimidazole compound represented by the above general formula (A) or the above general formula (A1) is added to an organic solvent and stirred, ultrasonicated The mixture is prepared by mixing. The organic solvent may be, for example, one previously dehydrated, a commercial product of dehydration grade, or the like, but if there is a large amount of water, the polymerization reaction may be interrupted, so the general formula (A) or the general formula The water content relative to the total weight of the benzimidazole compound and the organic solvent (A1) is preferably 100 ppm or less, more preferably 75 ppm or less, still more preferably 50 ppm or less, and particularly preferably 30 ppm or less.

<Production of Modified Olefin-Based Polymer>
Next, a method for producing a modified olefin polymer using the modifier for an olefin polymer of the present invention will be described. The method for producing a modified olefin polymer using the modifier for an olefin polymer of the present invention is not particularly limited as long as the modified olefin polymer of the present invention can be obtained, and for example, it is synthesized by a solution polymerization method. Alternatively, it may be synthesized by an emulsion polymerization method. From the viewpoint of the reactivity and operability of the modifier, a solution polymerization method using an inert solvent is preferable.

(Olefin based monomer)
The modifier for an olefin polymer of the present invention is used for the purpose of sealing the polymerization reactive terminal when polymerizing an olefin monomer. Here, the olefin-based monomer which is a production raw material is, for example, butadiene, isoprene, chloroprene, 2,3-dimethyl-1,3-butadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, etc. Diene-based monomers; aromatic vinyl-based monomers such as styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene or 2,4-diisopropylstyrene; ethylene, propylene, isobutylene, acrylonitrile or acrylic acid And vinyl monomers such as esters. In addition. These compounds may be used alone or in combination of two or more. Among these compounds, the olefin-based monomer is preferably at least one selected from the group consisting of butadiene, isoprene and styrene.

(Polymerization catalyst)
Here, as a polymerization reaction catalyst capable of polymerization reaction of an olefin monomer using the modifier for an olefin polymer of the present invention, for example, n-butyl lithium described in JP-A-2015-196759, Alkyl lithium reagents such as i-butyllithium, tert-butyllithium, etc .; titanium, cobalt, nickel, neodymium described in WO 2016/006665, WO 2013/130522, JP 2001-302703 etc. Or a combination of an organic metal compound such as an aliphatic carboxylic acid salt such as gadolinium or a diketone coordination substance and an organic aluminum such as triethylaluminum.

(Method of using modifier for olefin polymer in polymerization)
The modifier for an olefin-based polymer of the present invention is, for example, an active terminal of a polymer chain of an olefin-based monomer such as butadiene, isoprene or styrene as in the aromatic ketone compound described in JP-A-58-162604. By acting as a coupling agent to be reacted with, it is possible to denature the ends of the polymer chains and to stop the chain extension reaction. At this time, the amount (equivalent amount), concentration and use temperature of the modifying agent are not particularly limited.

(Modified olefin polymer)
The modified olefin-based polymer of the present invention obtained by the above production method is, for example, an olefin-based polymer (homopolymer, copolymer) obtained by polymerizing butadiene, isoprene, styrene or the like, and one side of the molecular end of the polymer (One end: the following formula (1)) or both sides (both ends: the following formula (2)) are treated with the modifier for an olefin polymer of the present invention. The introduction of the modifying agent can be specified, for example, from the fact that a benzene ring derived from a benzimidazole compound is bonded to the polymer using nuclear magnetic resonance spectroscopy (NMR) or the like. However, it is difficult to accurately identify G ′ after bonding, and it is difficult to directly specify the chemical structure of the terminally modified olefin polymer of the present invention.

（式（１）及び式（２）中、Ｒ^１、Ｒ^２、Ｌ及びｎは、前記一般式（Ａ）に記載のＲ^１、Ｒ^２、Ｌ及びｎと同義である。また、Ｐｏｌｙｍｅｒは、オレフィン系ポリマー（ホモポリマー、コポリマー）を表し、Ｇ’はＰｏｌｙｍｅｒ末端と変性剤との化学反応によって新たにできる結合である。）

(In Formula (1) and Formula (2), R ¹ , R ² , L and n have the same meanings as R ¹ , R ² , L and n described in the general formula (A), and Polymer is , An olefin-based polymer (homopolymer, copolymer), G 'is a bond that can be renewed by the chemical reaction of the polymer end with the modifier.

(Polymer)
In the above formulas (1) and (2), Polymer means, for example, an olefin-based polymer (homopolymer, copolymer) obtained by polymerizing at least one monomer selected from the group consisting of butadiene, isoprene and styrene .

Here, in the case of an olefin-based polymer obtained by polymerizing 1,3-butadiene as a monomer, the 1,4-polybutadiene which is a polymer is a cis-1,4 structure as a main component and a cis-1,4 structure The content is preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more. The Mooney viscosity (ML _{1 + 4} , 100 ° C.) is preferably 10 to 130, more preferably 15 to 80. Furthermore, the 5% toluene solution viscosity (Tcp) is preferably 25 to 300.

(Weight average molecular weight)
The weight average molecular weight (Mw) of the modified olefin polymer obtained using the modifier for an olefin polymer of the present invention is not particularly limited, but preferably 10,000 to 3,000,000, more preferably 100,000. -2,000,000, particularly preferably 100,000 to 1,500,000. The molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the modified olefin polymer is not particularly limited, but preferably 1.0 to 3.0. It is. In addition, these measurements are performed by GPC (gel permeation chromatography, polystyrene conversion) etc., for example. If the weight average molecular weight and molecular weight distribution of the modified olefin polymer are within this range, the balance between the processability of the rubber composition produced from this and the low heat buildup of the resulting crosslinked product is particularly good It becomes.

<Rubber composition>
The rubber composition of the present invention is produced using the modified olefin polymer of the present invention and carbon black as raw materials.

  Examples of the carbon black to be used include furnace black, acetylene black, thermal black, channel black and graphite. The carbon black to be used is not particularly limited, but the grade of carbon black to be used is appropriately determined depending on the type of car used, such as passenger car, truck, bus, etc., and the used portion of the tire such as base tread, sidewall, carcass or bead. Among carbon blacks, furnace black is more preferable, and specific examples thereof include SAF, ISAF, ISAF-HS, ISAF-LS, IISAF-HS, HAF, HAF-HS, HAF-LS, T-HS, T- NS, MAF, N234, FEF and the like can be mentioned. These carbon blacks can be used alone or in combination of two or more. Further, the compounding amount of carbon black is not particularly limited, but is, for example, 120 parts by weight or less with respect to 100 parts by weight of the rubber component in the rubber composition. The total amount of silica and carbon black is also not particularly limited, but is preferably 25 to 120 parts by weight, more preferably 30 to 100 parts by weight, and 35 to 90 parts by weight per 100 parts by weight of the rubber component in the rubber composition. Parts by weight are more preferred.

Furthermore, the nitrogen adsorption specific surface area (N ₂ SA) of the carbon black used in the present invention is not particularly limited, but preferably 5 to 250 m ² / g, more preferably 20 to 150 m ² / g, further preferably 40 to 40 It is 130 m ² / g. Further, the dibutyl phthalate (DBP) adsorption amount of carbon black is also not particularly limited, but is preferably 5 to 200 ml / 100 g, more preferably 50 to 160 ml / 100 g, and still more preferably 70 to 130 ml / 100 g. When the nitrogen adsorption specific surface area of carbon black is in this range, a rubber composition such as a rubber composition for tires having good processability which gives a crosslinked product which is particularly excellent in low heat buildup can be obtained.

(Other additives)
The rubber composition of the present invention may contain additives as appropriate in addition to the modified olefin polymer and carbon black. The type and amount of the additive are not particularly limited, and, for example, are appropriately used in accordance with the product specification, application, and the like.

<Method of producing rubber composition>
The method for blending the carbon black into the rubber composition of the present invention is not particularly limited. For example, a method of adding the carbon black to a modified olefin polymer and kneading it (dry kneading method) or a solution of a modified olefin polymer It is possible to apply a method (wet kneading method) or the like in which the above carbon black is added to coagulate and dry.

  Next, the present invention will be specifically described by way of examples. The raw materials and synthetic intermediates, the amounts used, the reaction conditions (temperature, time, reaction environment) and the operations described in the examples can be appropriately modified without departing from the technical concept of the present invention. That is, the scope of the present invention is not limited to the examples described below.

Example 1
First, as a modifying agent according to Example 1, a benzimidazole compound represented by the following formula (A1a) was synthesized. Specifically, under atmospheric pressure, 10.0 g (92.5 mmol) of 1,2-diaminobenolefin and 9.9 mL (92.5 mmol) of levulinic acid are added to 100 mL of 6 N aqueous hydrochloric acid solution in a 300 mL eggplant-type flask The mixture was heated to reflux for 18 hours. After completion of the reaction, aqueous ammonia was slowly added to the reaction solution cooled to room temperature for neutralization, and then 300 mL of ethyl acetate was added to extract the organic layer. The obtained organic layer was washed twice with 100 mL of saturated brine and dried over magnesium sulfate (anhydrous). Next, the dried organic layer was concentrated using an evaporator, and 50 mL of ethyl acetate was added again. To the resulting solution, 200 mL of IPE / heptane (50/50 wt%) was slowly added at room temperature to precipitate a solid. The precipitated solid was collected by filtration to obtain 4.30 g of a benzimidazole compound represented by the following formula (A1a), which is a target substance, as a pale yellow solid (primary crystal acquisition yield: 25%). The analytical data of the obtained compound are as follows.

(Analytical data: Formula (A1a): 4- (1H-benzoimidazol-2-yl) butan-2-one)
¹ H-NMR (heavy acetone, 400 MHz δ ppm): 2.05 (s, 3 H), 2.17 (s, 4 H), 3.08 (s, 4 H), 7.05 to 7.14 (m, 2 H) ), 7.42, 7.53 (d, 2 H), 11. 19 (bs, 1 H)
CI-MS (M ⁺ ): 188
EI-MS (M ⁺ +1): 189

  Next, the obtained benzimidazole compound (formula (A1a)) was heated and dissolved while adding toluene to obtain a modifier for an olefin polymer according to Example 1 as a toluene solution of about 0.2 mol / L.

  Next, a modified olefin-based polymer was manufactured using the obtained modifier for an olefin-based polymer according to Example 1. Specifically, 47.8 wt while maintaining an internal temperature of 3 ° C. or less in an autoclave (internal volume: 1.5 L) equipped with a stirrer, a thermometer, and a reagent inlet, the interior of which has been sufficiently replaced with nitrogen gas 600 ml of a solution of 1% 1,3-butadiene-cyclohexane was added. Then, 7 mL (4.2 mmol) of a 10.2 wt% triethylaluminum hexane solution (about 0.6 M) in this solution, 5 mM tris (2,2,6,6-tetramethylheptane-3,5-dionato) Add 3.6 mL (18 μmol) of a solution of gadolinium in cyclohexane and 9 mL (36 μmol) of a 4 mM solution of triphenylcarbenium tetrakis (pentafluorophenyl) borate in toluene while maintaining the internal temperature below 3 ° C, and add the internal temperature to 20 The temperature was raised to ° C., and the mixture was stirred for 25 minutes to carry out a polymerization reaction. At the end of the reaction, the prepared modifier (benzimidazole compound: 500 μM amount) was added to terminate the polymerization reaction. After completion of the reaction, 3 ml of 5.0 wt% anti-aging solution (Irganox, ethanol / n-heptane (vol / vol) = 1/1) is added and stirred for 3 minutes, and then about 300 ml of ethanol is added, The formed polymer was precipitated. The precipitated polymer was vacuum dried at 80 ° C. for 3 hours under reduced pressure (vacuum) to obtain 28.2 g of the terminally modified polybutadiene according to Example 1 as an objective product as a cloudy rubbery solid.

(result of analysis)
Since the peak derived from the benzene skeleton of benzimidazole (δ: between 8 and 6 ppm) was observed by ¹ H-NMR measurement (400 mHz, heavy toluene solvent), the terminally modified polybutadiene obtained was subjected to terminal modification. I judged that. Also, according to analysis by gel permeation chromatography (GPC, polystyrene standard), Mn: 25.7 × 10 ⁴ , Mw: 71.1 × 10 ⁴ , Mw / Mn: 2.77, Mooney viscosity (ML _{1 + 4/4} ) 100 DEG C. _, JIS-K6300): 56.4.

(Comparative example 1)
The same procedure as in Example 1 was carried out except that no modifier component was used, to obtain a terminal unmodified polybutadiene.

(Measurement of carbon gel sample)
Using about 1.0 g of the terminally modified polybutadiene (1-A1a) obtained in Example 1 as unvulcanized rubber, rubber test method third edition (Japan Rubber Association ed., Maruzen Publishing Co., Ltd.), “3.10 unadded Method of Analysis of Vulcanized Rubber "The amount of carbon gel was calculated according to the method described in the section (pages 164-165). Similarly, using the terminal unmodified polybutadiene obtained in Comparative Example 1, the amount of carbon gel was calculated.

(Measurement of carbon gel increase rate)
The carbon gel increase rate was calculated as the carbon gel increase rate (relative carbon gel increase rate) of Comparative Example 1 and Example 1 when the amount of carbon gel of a commercially available butadiene rubber was 1. The results are shown in Table 1.

  From Table 1, it was confirmed that the amount of carbon gel of the modified olefin polymer of the present invention is more increased than that of the unmodified polymer (BR 150 L, Comparative Example 1). From this result, when the modified olefin polymer of the present invention is used, for example, as a rubber for a tire, it is expected that the heat generation associated with the friction of tire components generated during traveling can be reduced and the fuel economy can be improved.

As described above, the modifier for an olefin polymer containing the benzimidazole compound of the present invention is obtained, for example, by using it as a modifier in the production of an olefin polymer (homopolymer, copolymer) such as butadiene, isoprene and styrene. It is useful to provide the modified olefin-based polymer (homopolymer, copolymer) described above mainly as a rubber composition for producing a tire that can be used as a base tread, a sidewall, etc. because improvement in fuel economy is expected.

Claims (9)

A modifier for an olefin polymer, comprising a benzimidazole compound represented by the following general formula (A).

(In the general formula (A), R ¹ represents a substituent of any carbon on the aromatic ring, and is a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a fluorine atom, fluorine A C1-C6 alkyloxy group which may be substituted by an atom, a C1-C6 dialkylamino group which may be substituted by a fluorine atom, a C1-C6 trialkylsilyl group, a carbon number Is any one of 1 to 6 di [tri (alkyl) silyl] amino group, nitro group, and hydroxyl group, n is an integer of 0 to 4. Here, when n is 2 or more, R ¹ is And each may be the same or different.
R ² represents a substituent on nitrogen, and is any of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may be substituted with a fluorine atom, and a trialkylsilyl group having 1 to 6 carbon atoms.
G represents a reactive group, and is a carboxylic acid alkyl ester group having an alkyl group of 1 to 6 carbon atoms which may be substituted by a fluorine atom, or an alkyl of 1 to 6 carbon atoms which may be substituted by a fluorine atom It is any of a ketone group, a C1-C6 alkylthio ketone group which may be substituted by a fluorine atom, and a cyano group.
L represents a divalent linking group, and in the main chain, a group selected from the group consisting of an alkylene group having 1 to 12 carbon atoms which may be substituted with a fluorine atom; an oxygen atom, a sulfur atom and a dimethylsilylene group One or more hetero-containing alkylene groups having 1 to 12 carbon atoms; vinylene group; and ethynylene group.
However, the molecular weight of the benzimidazole compound represented by the general formula (A) does not exceed 1000. ) A modifier for an olefin polymer comprising a benzimidazole compound represented by the following general formula (A1).

(In the general formula (A1), L and G have the same meanings as L and G described in the general formula (A).) G is any one of a C1-C6 alkyl ketone group which may be substituted by a fluorine atom, a C1-C6 alkylthio ketone group which may be substituted by a fluorine atom, and a cyano group; ,
A carbon having at least one group selected from the group consisting of an oxygen atom, a sulfur atom and a dimethylsilylene group in the main chain, wherein L is an alkylene group having 1 to 12 carbon atoms which may be substituted with a fluorine atom; The modifier for olefin polymers according to claim 1 or 2, which is any one of the hetero-containing alkylene groups of 1 to 12.   4. A modification according to any one of claims 1 to 3, characterized in that it contains at least one organic solvent selected from the group consisting of toluene, xylene, n-hexane, n-heptane, cyclohexane and methylcyclohexane. Agent.   A modified olefin polymer produced using the modifier for an olefin polymer according to any one of claims 1 to 4.   The modified olefin polymer according to claim 5, which is produced using at least one olefin monomer selected from the group consisting of butadiene, isoprene and styrene.   A method for producing a modified olefin polymer comprising using the modifier for an olefin polymer according to any one of claims 1 to 4.   8. The method for producing a modified olefin polymer according to claim 7, wherein at least one olefin monomer selected from the group consisting of butadiene, isoprene and styrene is used as a raw material. A rubber composition comprising the modified olefin polymer according to claim 5 and carbon black.