JP4273887B2 - Process for producing modified conjugated diene polymer - Google Patents

Description

  The present invention relates to a method for producing a novel modified conjugated diene polymer. More specifically, the present invention has a high 1,4-cis bond amount and a narrow molecular weight distribution, and more excellent rebound resilience and wear resistance by modification. The present invention relates to a method for producing a modified conjugated diene polymer.

In general, rubber for tires needs to have an excellent balance of impact resilience, abrasion resistance and low heat build-up, and for this purpose, polybutadiene having a 1,4-cis bond amount as high as possible and a narrow molecular weight distribution is required. ing.
The use of a polymerization catalyst containing a lanthanum series metal such as neodymium is known to be advantageous for the production of such polybutadiene (hereinafter sometimes referred to as “PB”). It has been broken.

For example, Patent Document 1 discloses a technique for polymerizing butadiene using a catalyst obtained by mixing and aging neodymium octoate, an organoaluminum compound, a hydrogenated organoaluminum compound, and a halogenated organoaluminum. However, although PB obtained by this has a high 1,4-cis bond amount, it is about 93%, which is not sufficient.
In Patent Document 2, butadiene is preferably polymerized using a polymerization catalyst mainly composed of a rare earth element-containing compound such as neodymium, an alumoxane, an organoaluminum compound, and a reaction product of a metal halide and a Lewis base. PB having a 1,4-cis bond amount of 93% or more and a molecular weight distribution index (weight average molecular weight / number average molecular weight) of 3.0 or less is obtained, and various compounds are added after the polymerization reaction to obtain a polymer. It has been reported that the modified PB reacted with is superior in resilience and abrasion resistance. However, the synthesis of alumoxane is complicated in this catalyst system, the reproducibility of the catalytic activity is not sufficient, and it is more expensive than the organic aluminum compound, so that improvement is desired from the viewpoint of industrial productivity. It was.

Japanese Patent Publication No. 1-55287 JP 2000-34320 A

  An object of the present invention is to provide a method capable of industrially advantageously producing a modified conjugated diene polymer having a high rebound resilience and abrasion resistance.

  As a result of intensive research to achieve the above object, the present inventor is composed of a lanthanum series metal, a specific organoaluminum compound, an organoaluminum hydride compound, and an organoaluminum halide compound, and is prepared by a particular method. It has been found that by polymerizing a conjugated diene using a polymerization catalyst, a conjugated diene polymer having an unprecedented high 1,4-cis bond amount and a narrow molecular weight distribution can be produced industrially and stably. Furthermore, it has been found that rebound resilience and wear resistance are further improved by reacting and modifying a specific compound with this conjugated diene polymer, and the present invention has been completed based on this finding.

Thus, according to the present invention, the following 1-2 are provided.
1. A lanthanum series metal compound (A), an organoaluminum compound (B) represented by the following general formula (1), an organoaluminum hydride compound (C) and an organoaluminum halide compound (D) are sequentially blended in this order. And after compounding the organoaluminum compound (B), before compounding the organoaluminum hydride compound (C), polymerizing the conjugated diene in the presence of a polymerization catalyst prepared by providing an aging step ,
A method for producing a modified conjugated diene polymer, comprising: reacting a conjugated diene polymer with a modifier that is at least one compound selected from the group consisting of a tin compound, an isocyanate compound, and an epoxy compound after the polymerization reaction.
Al (R ¹ ) (R ² ) (R ³ ) (1)
(R ¹ , R ² and R ³ each independently represent a hydrocarbon group having 1 to 20 carbon atoms.)
2. The lanthanum series metal compound (A) methods for producing the aforementioned 1 Symbol placement of modified conjugated diene polymer is a neodymium compound.

  According to the method of the present invention, there is provided a method capable of industrially advantageously producing a modified conjugated diene polymer having high rebound resilience and wear resistance.

The polymerization catalyst used in the present invention includes a lanthanum series metal compound (A), an organoaluminum compound (B) represented by the following general formula (1), an organoaluminum hydride compound (C), and an organoaluminum halide compound (D). Are sequentially blended in this order , and after the organoaluminum compound (B) is blended, it is prepared by providing an aging step before blending the organoaluminum hydride compound (C) .
Al (R ¹ ) (R ² ) (R ³ ) (1)
(R ¹ , R ² and R ³ each independently represent a hydrocarbon group having 1 to 20 carbon atoms.)

The lanthanum series metal compound (A) is a salt, alkoxide or complex of the lanthanum series metal (A1), and among them, a salt is preferable.
The lanthanum series metal (A1) is at least one metal selected from lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium. Among these, lanthanum, cerium, praseodymium, neodymium, samarium and gadolinium are preferable, and the amount of 1,4-cis bond and polymerization activity of the resulting polymer can be increased, and neodymium is particularly easy to obtain and easy to handle. preferable.

Examples of the compound (A2) which forms a salt, alkoxide or complex with the lanthanum series metal (A1) include carboxylic acid, phosphorus-containing organic acid, phenols, alcohols and β-diketones. Of these, carboxylic acids and phosphorus-containing organic acids are preferable, and carboxylic acids are more preferable.
Examples of the salt include carboxylate and phosphorus-containing organic acid salt. These may also be of a complex salt structure consisting of different bonding modes, such as a complex salt of a carboxylate and a phosphorus-containing organic acid salt ([carboxylate] [phosphorus-containing organic acid salt]). Good. Among these, carboxylates are more preferable.

  The carboxylic acid that forms the carboxylate is not particularly limited. Carbon number of carboxylic acid is C2-C20 normally. Specific examples thereof include acetic acid, octanoic acid, octenoic acid, lauric acid, versatic acid (aliphatic monocarboxylic acid having 6 to 20 carbon atoms having a carboxyl group on a tertiary carbon in which three alkyl groups having 1 or more carbon atoms are bonded). Examples thereof include aliphatic carboxylic acids such as Versatic-10 sold by Shell Chemical Co .; aryl-substituted aliphatic carboxylic acids such as phenylacetic acid; alicyclic rings such as cyclopentanecarboxylic acid Aromatic carboxylic acids such as benzoic acid and naphthenic acid; and the like. Among these, aliphatic carboxylic acids having 6 to 20 carbon atoms are preferable, and versatic acid is more preferable from the viewpoint of obtaining a catalyst with high polymerization activity.

  The phosphorus-containing organic acid is not particularly limited, but a compound represented by the following general formula (2) is preferable.

（Ｒ^４及びＲ^５は独立して、水素原子、水酸基または炭素数１〜２０の、アルキル基、アラルキル基、アリール基、アルコキシ基、フェノキシ基若しくはアルキルフェノキシ基を表わす。）

(R ⁴ and R ⁵ independently represent a hydrogen atom, a hydroxyl group, or an alkyl group, aralkyl group, aryl group, alkoxy group, phenoxy group or alkylphenoxy group having 1 to 20 carbon atoms.)

  Specific examples of the compound represented by the above formula (2) include dibutyl phosphate, dihexyl phosphate, dioctyl phosphate, bis (2-ethylhexyl phosphate), bis (1-methylheptyl phosphate), dioleyl phosphate, Phosphoric acid dialkyl ester such as butyl phosphate (2-ethylhexyl) and phosphoric acid (1-methylheptyl) (2-ethylhexyl); phosphoric acid diaryl ester such as diphenyl phosphate; 2-ethylhexylphosphonic acid mono-2-ethylhexyl; Monoalkylphosphonic acid monoalkyl esters such as 2-ethylhexylphosphonic acid monobutyl; monoalkylphosphonic acid monoaryl esters such as 2-ethylhexylphosphonic acid monophenyl; mono-2-ethylhexyl phosphonate, mono-1-methylheptyl phosphonate, etc. The phospho Acid monoalkyl ester; phosphonic acid monoaryl ester such as monophenyl phosphonate; dibutylphosphinic acid, bis (2-ethylhexyl) phosphinic acid, bis (1-methylheptyl) phosphinic acid, dioleylphosphinic acid, (2-ethylhexyl) (1-methylheptyl) phosphinic acid and other dialkylphosphinic acids; diphenylphosphinic acid and other diarylphosphinic acids; and the like.

  Examples of phenols include alkyl-substituted monophenols such as 2,6-t-butylphenol and 2,6-t-butyl-4-methylphenol.

  Examples of alcohols include aliphatic alcohols having 1 to 10 carbon atoms such as methanol, ethanol, isopropanol, t-butanol, t-amyl alcohol, 2-butenyl alcohol, and 3-hexenyl alcohol; carbon numbers such as cyclohexyl alcohol. 3-6 alicyclic alcohols; aryl substituted aliphatic alcohols having 7 to 10 carbon atoms such as benzyl alcohol; and the like.

  Examples of β-diketones include acetylacetone, benzoylacetone, ethylacetylacetone and the like having 5 to 12 carbon atoms.

General formula (1) used in the present invention
Al (R ¹ ) (R ² ) (R ³ ) (1)
(R ¹ , R ² and R ³ each independently represent a hydrocarbon group having 1 to 20 carbon atoms.)
Examples of the hydrocarbon group having 1 to 20 carbon atoms represented by the organoaluminum compound (B) represented by the formula: methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl An alkyl group having 1 to 20 carbon atoms such as a group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group; cyclopentyl group, A cycloalkyl group having 3 to 6 carbon atoms such as a cyclohexyl group; an aralkyl group having 7 to 20 carbon atoms such as a benzyl group, a 2-phenylethyl group and a 3-phenylpropyl group; a phenyl group, a 1-naphthyl group and a 2-naphthyl group An aryl group having 6 to 20 carbon atoms, such as a group;
Among these, an alkyl group is most preferable. Further, the alkyl group, aralkyl group and aryl group may have a substituent at any position.

  Specific examples of the organoaluminum compound (B) include trimethylaluminum, triethylaluminum, tri-n-propylaluminum, triisopropylaluminum, trin-butylaluminum, triisobutylaluminum, methyldiisobutylaluminum, trin-pentylaluminum, trin -Hexylaluminum, tricyclohexylaluminum, tribenzylaluminum, dimethylbenzylaluminum, diethylbenzylaluminum, triphenylaluminum, tri (4-methylphenyl) aluminum, trinaphthylaluminum, phenyldimethylaluminum, phenyldiethylaluminum and the like. Among these, triethylaluminum or triisobutylaluminum is preferable from the viewpoints of availability and ease of handling and imparting high activity to the catalyst.

The organoaluminum hydride compound (C) used in the present invention is a compound represented by the following formula (3).
Al (R ⁶ ) _3-n (H) _n (3)
(R ⁶ represents a hydrocarbon group having 1 to 10 carbon atoms, n is 1 or 2, and preferably 1. When n is 1, two R ⁶ are the same or different. May be.)

Examples of the hydrocarbon group having 1 to 10 carbon atoms of R ⁶ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, an alkyl group having 1 to 10 carbon atoms such as n-pentyl group and n-hexyl group; a cycloalkyl group having 3 to 6 carbon atoms such as cyclopentyl group and cyclohexyl group; 7 carbon atoms such as benzyl group and 2-phenylethyl group -10 aralkyl groups; aryl groups having 6 to 10 carbon atoms such as phenyl groups; and the like. Among these, an alkyl group is preferable. The alkyl group, aralkyl group and aryl group may have a substituent at any position.

Specific examples of the organic aluminum hydride compound (C) include methylaluminum hydride, ethylaluminum hydride, hydrogenated n-propylaluminum, hydrogenated isopropylaluminum, hydrogenated n-butylaluminum, hydrogenated isobutylaluminum, hydrogenated n - pentyl aluminum hydride, neopentyl aluminum hydride, n- hexyl aluminum hydride, iso-hexyl aluminum hydride, cyclohexyl aluminum, such as hydrogenated phenyl aluminum, formula: Al (R ⁶⁾ aluminum represented with H ₂ hydrogen Hydride: dimethylaluminum hydride, diethylaluminum hydride, di-n-propylaluminum hydride, diisopropylaluminum hydride, di-n-butylaluminum hydride, diisobutylaluminum hydride Arm, hydrogen di n- pentyl aluminum hydride, di-neopentyl aluminum, hydrogen di n- hexyl aluminum hydride, di-iso-hexyl aluminum hydride, dicyclohexyl aluminum, such as hydrogenated diphenyl aluminum formula: Al (R ⁶ ) Aluminum hydride represented by ₂ H;

The organoaluminum halide compound (D) used in the present invention is a compound represented by the following formula (4).
Al (R ⁷ ) _m (X) _3-m (4)
(R ⁷ represents a hydrocarbon group having 1 to 10 carbon atoms, X represents a halogen atom such as chlorine or bromine, m is 1 or 2, and is preferably 1. When m is 2, two R ⁷ may be the same or different. Examples of the hydrocarbon group having 1 to 10 carbon atoms of the R ^7, include those similar to the hydrocarbon group having 1 to 10 carbon atoms of the R ⁶ Among them, an alkyl group is preferable.)

  Specific examples of the organic aluminum halide compound (D) include dimethylaluminum chloride, dimethylaluminum bromide, diethylaluminum chloride, diethylaluminum bromide, dibutylaluminum chloride, dibutylaluminum bromide, methylaluminum sesquichloride, ethylaluminum sesquichloride, methylaluminum dichloride. , Ethylaluminum dichloride, butylaluminum dichloride, and the like. These can be used alone or in combination of two or more.

Conjugate diene polymerization catalyst is a lanthanum series metal compound (A) (hereinafter sometimes referred to as "component (A)".), Organic aluminum compound (B) (hereafter, referred to sometimes as "component (B)". ), An organoaluminum hydride compound (C) (hereinafter sometimes referred to as “component (C)”), and an organoaluminum halide compound (D) (hereinafter sometimes referred to as “component (D)”). And the component (C) is blended after the component (B).
Furthermore, it is preferable to prepare by mixing the component (A), the component (B), the component (C) and the component (D) in this order. By blending the components in this order, a polymerization catalyst having a high polymerization activity, a high cis-1,4-bond content, and a conjugated diene polymer having a narrow molecular weight distribution can be obtained. .

  The usage-amount of a component (B) is 5-60 mol normally with respect to 1 mol of lanthanum series metals of a component (A), Preferably it is 10-50 mol, More preferably, it is 15-40 mol. The amount of component (C) to be used is generally 1-50 mol, preferably 3-30 mol, more preferably 5-20 mol, per 1 mol of the lanthanum series metal of component (A). The amount of component (D) used is usually 0.1 to 20 mol, preferably 0.5 to 10 mol, more preferably 1 to 5 mol, per 1 mol of the lanthanum series metal of component (A).

  The molar ratio of component (B) to component (C) used is the ratio of component (B) / component (C), preferably 0.1 to 10, more preferably 0.5 to 5. preferable. If this value is too small, the molecular weight distribution of the resulting conjugated diene polymer will be wide, and the cis content may be low. Conversely, if this value is too large, the molecular weight of the resulting conjugated diene polymer may increase.

When producing the polymerization catalyst, it is preferable to dissolve in a solvent when the catalyst component used is solid. Although it does not specifically limit as a solvent used here, C1-C10 linear or cyclic hydrocarbon which may be substituted by the halogen atom, and C6-C12 which may be substituted by the halogen atom Examples include aromatic hydrocarbons and monoolefins.
Examples of the chain or cyclic hydrocarbon include n-butane, n-pentane, n-hexane, n-heptane, n-octane, and cyclohexane. Examples of the hydrocarbon substituted with a halogen atom include chloroform, methylene chloride, dichloroethane, and the like. Aromatic hydrocarbons include benzene, toluene, xylene and the like. Examples of the aromatic hydrocarbon substituted with a halogen atom include chlorobenzene. Examples of monoolefins include 1-butene and 2-butene. Among these, n-hexane and cyclohexane are preferable.

  The reaction temperature and reaction time for preparing the polymerization catalyst are not particularly limited, but the mixture of components (A) to (D) is usually −78 to + 100 ° C., preferably −20 to + 80 ° C., usually 1 second to It is preferable to stir for 24 hours.

Moreover, it is preferable to provide an aging process after mix | blending a component (B) and before mix | blending a component (C). In the present invention, an aging process is provided. The aging process is a process in which a certain period of time is passed after the blending of the component (B) and the blending of the component (C) in order to sufficiently react the component (A) and the component (B) before blending the component (C). It is. The time (aging time) is preferably 1 to 60 minutes, more preferably 5 to 30 minutes. When the aging time is too short, for example, when the component (B) is blended almost simultaneously without blending the component (B), a catalyst having high polymerization activity cannot be obtained, and the molecular weight distribution However, it becomes impossible to obtain a conjugated diene polymer having a narrow width. Conversely, when the aging time is too long, the polymerization activity is lowered, which is not preferable.

  Furthermore, after blending the component (B), it is more preferable to blend a small amount of conjugated diene before blending the component (C). By blending a small amount of conjugated diene, the activity of the polymerization catalyst becomes higher. The conjugated diene used here is preferably a conjugated diene used for polymerization. The amount of the conjugated diene used is not particularly limited, but is usually 1 to 200 mol, preferably 10 to 100 mol, per 1 mol of the lanthanum series metal of the component (A).

  The polymerization catalyst of the present invention obtained as described above can be used as it is for the polymerization of a conjugated diene, or can be used after the solvent is distilled off. Moreover, it can also be used after refine | purifying as needed.

The polymerization catalyst used in the present invention may be supported on a carrier such as carbon black, an inorganic compound, or an organic polymer compound. By carrying it, it is possible to prevent contamination of the polymerization reactor due to adhesion of the catalyst.
Preferred examples of the inorganic compound serving as a carrier include inorganic oxides such as silica, alumina, magnesia, titania, zirconia, and calcia, and inorganic chlorides such as magnesium chloride. These inorganic compounds are preferably porous particles having an average particle diameter of 5 to 150 μm and a specific surface area of ² to 800 m ² / g. Usually, heat treatment is performed at 100 to 800 ° C. to remove moisture and use as a carrier. use.

  Examples of the organic polymer compound as a simple substance include a carboxy-modified crosslinked styrene copolymer composed of styrene-methacrylic acid-divinylbenzene. These organic polymer compounds are preferably spherical particles having an average particle diameter of 5 to 250 μm.

In addition to the components (A) to (D), the polymerization catalyst used in the present invention further contains at least one metal organic compound selected from Periodic Tables 1 to 3, 12 and Group 13 elements. Also good. Although it does not specifically limit as this organometallic compound, For example, an organolithium compound, an organomagnesium compound, an organomagnesium halide, etc. are mentioned.
Examples of the organic lithium compound include methyl lithium, butyl lithium, and phenyl lithium. Examples of the organic magnesium compound include dibutyl magnesium. Examples of the organic magnesium halide include ethyl magnesium chloride and butyl magnesium chloride.

The conjugated diene polymer which is the base polymer of the modified conjugated diene polymer produced by the method of the present invention is a conjugated diene in the presence of the above conjugated diene polymerization catalyst, or a conjugated diene and other monomers copolymerizable therewith. The polymer is produced by anionic polymerization.
Conjugated dienes include 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, 1,3-pentadiene, , 3-hexadiene and the like. These can be used alone or in combination of two or more. Among these, 1,3-butadiene and 2-methyl-1,3-butadiene are preferable, and 1,3-butadiene is more preferable.

  The other monomer is not particularly limited as long as it can be copolymerized with a conjugated diene, but styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, o- Ethyl styrene, m-ethyl styrene, p-ethyl styrene, pt-butyl styrene, α-methyl styrene, α-methyl-p-methyl styrene, o-chloro styrene, m-chloro styrene, p-chloro styrene, p -Aromatic vinyl monomers such as bromostyrene, 2-methyl-4,6-dichlorostyrene, 2,4-dibromostyrene, vinylnaphthalene; carbon such as ethylene, propylene, 1-butene, cyclopentene, 2-norbornene Monoolefin monomer having 2 to 10; 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene C5-C10 non-conjugated diene monomer such as ene, dicyclopentadiene, 5-ethylidene-2-norbornene; C1-C8 such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate α, β-ethylenically unsaturated carboxylic acid alkyl ester monomer; and the like. The amount of other monomers copolymerizable with the conjugated diene is usually 80% by weight or less, preferably 50% by weight or less of the conjugated diene.

  The amount of the polymerization catalyst used (indicated by the molar amount of the component (A) relative to 1 mol of the monomer) is usually 0.001 to 100 mmol, preferably 0.005 to 50 mmol. If the amount of (A) used is excessively small, the polymerization activity may be insufficient. If it is excessively large, the molecular weight of the resulting polymer may be too small, or removal of the catalyst residue may be difficult. .

  The polymerization method is not particularly limited, and examples thereof include a bulk polymerization method, a solution polymerization method and a slurry polymerization method in an inert solvent, and a gas phase polymerization method using a gas phase stirring tank and a gas phase fluidized bed. Among these methods, the solution polymerization method capable of narrowing the molecular weight distribution is preferable. The solution polymerization method may be a batch type or a continuous type.

  Although it does not specifically limit as an inert solvent used by a solution polymerization method, A C4-C10 linear or cyclic saturated hydrocarbon and C6-C12 aromatic hydrocarbon, 1-butene, 2-butene, etc. And these monoolefins may be substituted with a halogen atom. Examples of the saturated hydrocarbon include n-butane, n-pentane, n-hexane, n-heptane, n-octane, and cyclohexane. Examples of the saturated hydrocarbon substituted with a halogen atom include chloroform, methylene chloride, dichloroethane and the like. Aromatic hydrocarbons include benzene, toluene, xylene and the like. Examples of the aromatic hydrocarbon substituted with a halogen atom include chlorobenzene. Among these, n-hexane and cyclohexane are preferable.

  The polymerization temperature is usually −50 to + 200 ° C., preferably 0 to 150 ° C., more preferably 20 to 90 ° C. The polymerization time is about 1 second to 20 hours, and the polymerization pressure is about 0.1 to 3 MPa.

  Chain transfer agents can be used to control the molecular weight of the conjugated diene polymer. As the chain transfer agent, those conventionally used in the production of 1,4-cis polybutadiene rubber can be used. Specific examples thereof include allenes such as 1,2-butadiene and cyclic dienes such as cyclooctadiene. Is mentioned. Further, the same effect can be obtained even when the polymerization reaction is carried out in the presence of hydrogen gas.

  The conjugated diene polymer obtained by the polymerization reaction has a 1,4-cis bond amount of usually 96 mol% or more, a number average molecular weight (Mn) of usually 100,000 to 500,000, and an index of molecular weight distribution. The value of the ratio (Mw / Mn) of a certain weight average molecular weight (Mw) and number average molecular weight (Mn) is usually 2-5. Polymerization using a catalyst prepared by mixing the components (A), (B), (C), and (D) and blending the component (C) after the component (B). Thus, a conjugated diene polymer having such a high 1,4-cis bond amount and a narrow molecular weight distribution can be obtained.

The method of manufacturing a variant conjugated diene polymer, the modifying agent used to modify the conjugated diene polymer after the completion of the polymerization reaction, introducing a functional group into the active end of the conjugated diene polymer by anionic polymerization The compound is not particularly limited as long as the compound can be used. Such a modifier is preferably a tin compound, an isocyanate compound, an epoxy compound, a quinone compound, an ester compound, a carbonic acid ester compound, a carboxylic acid, an acid halide or the like, and at least selected from the group consisting of a tin compound, an isocyanate compound and an epoxy compound. One compound is more preferred. In the present invention, at least one compound selected from the group consisting of tin compounds, isocyanate compounds and epoxy compounds is used.

The tin compound used as the modifier has a tin halide which may have 1 to 3 hydrocarbon groups having 1 to 10 carbon atoms, or 1 to 3 hydrocarbon groups having 1 to 20 carbon atoms. Organotin organic acid salt.
Specific examples of tin halides include tributyl tin chloride, triisopropyl tin chloride, trihexyl tin chloride, trioctyl tin chloride, triphenyl tin chloride, diphenyl tin dichloride, dibutyl tin dichloride, dihexyl tin dichloride, dioctyl tin dichloride, phenyl tin trichloride. Butyltin trichloride, octyltin trichloride, tin tetrachloride and the like. Among them, butyltin trichloride, octyltin trichloride and tin tetrachloride are preferable.

  Specific examples of organic tin organic acid salts include tri-n-butyltin acetate, tri-n-butyltin laurate, tri-n-butyltin-2-ethylhexaate, tri-n-butyltin acrylate, trioctyltin acetate, Tristearyl tin acrylate, triphenyltin laurate, tribenzyltin laurate, di-n-butyltin diacetate, di-t-butyltin di-2-ethylhexaate, dioctyltin dinaphthate, diphenyltin diacrylate, n-butyltin Organotin monobasic organic acid salts such as trilaurate, t-butyltin tri-2-ethylhexate, octyltin triacrylate; di-t-butyltin bismethyl adipate, di-t-butyltin bisoctyl adipate, di- t-butyltin Subenzyl adipate, di-n-butyltin bisbenzyl malate, di-n-butyltin bisbutyl malate, dihexyltin bismethylmalate, di-2-ethylhexyltin bis-2-ethylhexyl taconate, dioctyltin bisoctylitaco , Diphenyltin bisoctyl itaconate, di-n-butyltin bismethylmesaconate, di-n-butyltin bis-2-ethylhexyl mesaconate, diisopropyltin bisbenzylmesaconate, dihexyltin bisoctyl succinate, distearyl tin bis Organotin dibasic organic acid monoester salts such as 2-ethylhexyl succinate, diphenyltin bisbenzyl succinate; and di-t-butyltin adipate, diisopropyltin malate, di Hexyl tin malate, di-2-ethylhexyl tin itaconate, distearyl sparrow Sako sulfonates, and organic tin dibasic organic acid salts such as diphenyl tin succinate.

The isocyanate compound used as the modifier is a monoisocyanate, diisocyanate or triisocyanate having a hydrocarbon group having 1 to 20 carbon atoms.
Specific examples of monoisocyanates include phenyl isocyanate. Specific examples of diisocyanates include 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), 4,4'-diphenylmethane diisocyanate (MDI), hexa Examples include methylene diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, and 1,5-naphthylene diisocyanate. Specific examples of triisocyanates include 1,3,6-hexamethylene triisocyanate, 1,6,11-undecane triisocyanate, and bicycloheptane triisocyanate.

Epoxy compounds used as modifiers include monoepoxy hydrocarbons having 2 to 12 carbon atoms; glycidyl ethers having a hydrocarbon group having 1 to 12 carbon atoms; glycidyl esters of organic acids; glycidyl amines; An epoxy group-containing polymer or an epoxy group-containing silane compound.
Examples of the monoepoxy hydrocarbons include ethylene oxide, propylene oxide, cyclohexene oxide, and styrene oxide. Examples of glycidyl ethers include butyl glycidyl ether, phenyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, ethylene glycol diglycidyl ether, and neopentyl glycol diglycidyl ether. Examples of organic acid glycidyl esters include glycidyl methacrylate and glycidyl acrylate. Examples of glycidylamines include N, N-diglycidylaniline, N, N-diglycidyltoluidine, N, N-glycidylglycidyloxyaniline, and the like. Examples of the fat epoxidized product include epoxidized soybean oil and epoxidized linseed oil. Examples of the epoxy group-containing polymer include epoxidized polybutadiene, epoxidized natural rubber, trimethylolpropane polyglycidyl ether, glycerol polyglycidyl ether, polypropylene glycol diglycidyl ether, and polyethylene glycol diglycidyl ether. Examples of the epoxy group-containing silane compound include 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropyltriphenoxysilane, (3-glycidyloxypropyl) methyldimethoxysilane, (3 -Glycidyloxypropyl) methyldiethoxysilane, (3-glycidyloxypropyl) methyldiphenoxysilane, (3-glycidyloxypropyl) methyldimethoxysilane condensate, (3-glycidyloxypropyl) methyldiethoxysilane condensate , Β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like.

The above-mentioned modifiers such as tin compounds, isocyanate compounds, and epoxy compounds can be used alone or in combination of two or more. The amount of the modifier used is usually 0.01 to 200, preferably 0.05 to 150, in a molar ratio with respect to the lanthanum series metal compound (A) of the polymerization catalyst of the conjugated diene polymer. If the amount of the modifier used is excessively small, the modification reaction may not be sufficiently performed. Conversely, even if the modifier is excessively increased, there may be no difference in the physical property improving effect, which is not economical.
The modification reaction of the conjugated diene polymer is performed by adding the above modifier to the polymerization system and mixing when the polymerization reaction to obtain the conjugated diene polymer of the base polymer reaches a predetermined polymerization conversion rate, usually 95 mol% or more. To do. The reaction temperature is usually −30 ° C. to + 130 ° C., preferably 20 to 80 ° C., and the reaction time is usually 5 minutes to 10 hours, preferably 10 minutes to 5 hours.

  When the modification reaction is completed, polymerization stoppers such as water, methanol, propanol, hydrochloric acid, citric acid, etc .; anti-aging agents such as phenols, phosphoruss, amines, etc .; mineral process oils, synthetic process oils, etc. After adding the extender; and the like, the polymer is recovered from the polymer solution. As a method for recovering the polymer, a known method such as steam stripping or a coagulation method using a poor solvent or a direct drying method can be employed.

The modified conjugated diene polymer obtained by the method of the present invention has a 1,4-cis bond amount of usually 90 mol% or more, preferably 96 mol% or more, and a number average molecular weight (Mn) of usually 50,000. ˜1,000,000, preferably 100,000 to 500,000, and Mw / Mn is usually 2 to 5. Compared with the end of the polymerization reaction of the conjugated diene polymer, Mn becomes higher, and the influence of modification of the molecular chain terminal by the modifying agent appears.
If the amount of 1,4-cis bond is excessively small, the wear resistance may not be improved, and even if Mw / Mn is excessively large, the wear resistance may not be improved.
The Mooney viscosity (ML _{1 + 4} , 100 ° C.) of the modified conjugated diene polymer obtained by the method of the present invention is usually 10 to 150, preferably 20 to 100. If the Mooney viscosity is excessively small, the abrasion resistance after vulcanization may be inferior. Conversely, if it is excessively large, the workability during kneading may be deteriorated.
The modified conjugated diene copolymer was introduced into the polymer molecule in addition to the conjugated diene polymer of the base polymer having a high 1,4-cis bond amount and a narrow molecular weight distribution due to the effect of the polymerization catalyst. Since the compatibility with fillers such as carbon black and silica is improved by the action of the functional group, mechanical strength, abrasion resistance, rebound resilience and the like are further improved.

  The modified conjugated diene polymer obtained by the method of the present invention may be used as an extender, plasticizer, lubricant, filler, vulcanizing agent, vulcanization accelerator, vulcanization activator, anti-aging agent, or isoprene rubber. In addition to tires that require characteristics such as impact resilience, wear resistance, mechanical strength and low heat build-up, hose, other rubbers such as styrene-butadiene rubber and natural rubber are compounded and vulcanized. , Belts, and other various industrial products. It can also be used as a resin impact resistance improver.

The present invention will be specifically described below with reference examples, examples and comparative examples. In the following, “part” and “%” are based on weight unless otherwise specified. The test, evaluation, and production of neodymium salt versatic acid were as follows.
(1) Polymer analysis method

The amount of 1,4-cis bond was determined by ¹ H-NMR and ¹³ C-PST-NMR analysis.
Mw, Mn, and molecular weight distribution index (Mw / Mn) of the polymer were determined by gel permeation chromatography. That is, Mw and Mn were determined based on a calibration curve prepared using a standard polybutadiene sample (manufactured by Polymer Laboratories) using two Tohso GMH columns connected together and tetrahydrofuran as an eluent.
(2) Rebound resilience

According to JIS K6255, Lupke rebound resilience was measured at 60 ° C. This value was expressed as an index with the measured value in Comparative Example 2 below as 100. It shows that it is excellent in impact resilience, so that this value is high.
(3) Abrasion resistance

According to JIS K6264, the measurement was performed using a Lambourne abrasion tester. This value is shown as an index with the measured value in Comparative Example 2 as 100. It shows that it is excellent in abrasion resistance, so that this value is high.
(4) Manufacture of neodymium salt versatic acid

Versatic acid (Versatic-10, manufactured by Shell) 3.5 parts was added to 15 parts of an aqueous solution in which 0.8 parts of sodium hydroxide had been dissolved to prepare an aqueous solution of sodium versatate. Next, the above-mentioned sodium versatate aqueous solution was added dropwise to an aqueous solution in which 4 parts of neodymium chloride had been dissolved, with vigorous stirring. The blue-violet viscous material formed in the aqueous solution was sufficiently washed with water and dried to obtain a neodymium salt of versatic acid.
(Examples 1-3)

The neodymium salt (1 mol) obtained in the above (4) is dissolved in 200 parts of n-hexane, and the amounts of triisobutylaluminum (TIBAL) and 1,3-butadiene (n-hexane solution) shown in Table 1 are dissolved therein. ), Diisobutylaluminum hydride (DIBAH) and diethylaluminum chloride (DEAC) were sequentially formulated in this order at room temperature. The mixture was further stirred at room temperature for 1 hour to obtain three types of catalyst solutions. An aging time was provided from the TIBAL formulation to the DIBAH formulation.
TIBAL, DIBAH and DEAC charge (relative aluminum moles relative to neodymium), 1,3-butadiene charge (relative moles butadiene relative to neodymium), TIBAL and DIBAH charge ratio (relative moles of TIBAL / DIBAH) Ratio) and the aging time (minutes) from the blending of TIBAL to the blending of DIBAH are shown in Table 1.

Next, cyclohexane and 1,3-butadiene were charged into a pressure-resistant glass autoclave so that the concentration of 1,3-butadiene was 15%. Next, the catalyst solution was added and the polymerization reaction was carried out at 40 ° C. for 100 minutes while stirring. When the polymerization conversion rate of the base polymer reached 100%, a modifier having the substance name and amount shown in Table 2 was added, and the mixture was stirred at 40 ° C. for 60 minutes to carry out a modification reaction. Thereafter, a small amount of methanol was added to stop the reaction. After adding 0.2 part of 2,4-bis (n-octylthiomethyl) -6-methylphenol as an anti-aging agent per 100 parts of the polymer, A polymer was precipitated by a ripping method and dried to obtain a modified conjugated diene polymer. The obtained modified conjugated diene polymer (modified PB) was measured for 1,4-cis bond amount, number average molecular weight (Mn), and molecular weight distribution index (Mw / Mn).
100 parts of the modified PB obtained are 50 parts of carbon black (N339), 5 parts of aroma oil, 3 parts of zinc oxide (zinc white # 1), 2 parts of stearic acid and 1 part of anti-aging agent (6PPD). After kneading in a mixer for 6 minutes so that the discharge temperature of the kneaded product is 120 ° C., the resulting mixture is transferred to an open roll at 50 ° C. and 1.5 parts of sulfur (S # 325) and vulcanized. A rubber compound was obtained by adding 1.1 parts of accelerator (CBS) and kneading. A test piece of vulcanized rubber was obtained by performing press vulcanization at 160 ° C. for 10 to 15 minutes, and a test for rebound resilience and wear resistance was performed using the test piece.
The amount of catalyst used with respect to the total 1,3-butadiene used in the polymerization reaction (number of millimoles of neodymium with respect to 1 mol of monomer), yield, 1,4-cis bond amount, Mw, of the obtained polymer Table 2 shows the test results of Mn, Mw / Mn, impact resilience, and abrasion resistance. The yield is a yield per unit quantity of neodymium used.
(Comparative Example 1)

In Example 1, when the polymerization conversion rate reached 100%, the reaction was stopped by adding a small amount of methanol without adding a modifier, and the same procedure as in Example 1 was performed. The preparation conditions of the polymerization catalyst are shown in Table 1, and the analysis results and test results of the obtained PB are shown in Table 2.
(Comparative Example 2)

  In Example 1, a catalyst was obtained in the same manner as in Example 1 except that the blending amounts of TIBAL and DIBAH were each doubled, the blending order of these two components was changed, and no aging was performed. A modified PB was obtained by conducting a polymerization reaction and a modification reaction in the same manner as in Example 1 except that this catalyst was used. The conditions for preparing the polymerization catalyst are shown in Table 1, and the analysis results and test results of the obtained modified PB are shown in Table 2.

As Table 2 shows, the modified PB obtained by the method of the present invention has a high 1,4-cis bond amount and a suitable Mn, and has a narrow molecular weight distribution with Mw / Mn close to 1. The rubber obtained by vulcanizing it has remarkably large resilience and extremely excellent wear resistance (Examples 1 to 3).
On the other hand, when polymerization was performed with the polymerization catalyst used in the method of the present invention, but no modification reaction was performed after polymerization, PB itself had a high 1,4-cis bond amount, Mn was preferable, and Mw / Mn was 1 A polymer close to the above is obtained, and the resilience and wear resistance are excellent to some extent, but the resilience and wear resistance in the above-mentioned examples of the present invention are not reached (Comparative Example 1). In addition, when polymerization is performed using a catalyst prepared without reversing the blending order of TIBAL and DI BAH and without providing aging, the polymerization activity decreases, and the resulting PB has a low 1,4-cis bond amount, Mw / Mn also had a broad molecular weight distribution at a value away from 1, and even when it was modified, both resilience and wear resistance were insufficient (Comparative Example 2).

Claims (2)

A lanthanum series metal compound (A), an organoaluminum compound (B) represented by the following general formula (1), an organoaluminum hydride compound (C) and an organoaluminum halide compound (D) are sequentially blended in this order. And after compounding the organoaluminum compound (B), before compounding the organoaluminum hydride compound (C), polymerizing the conjugated diene in the presence of a polymerization catalyst prepared by providing an aging step ,
A method for producing a modified conjugated diene polymer, comprising: reacting a conjugated diene polymer with a modifier that is at least one compound selected from the group consisting of a tin compound, an isocyanate compound, and an epoxy compound after the polymerization reaction.
Al (R ¹ ) (R ² ) (R ³ ) (1)
(R ¹ , R ² and R ³ each independently represent a hydrocarbon group having 1 to 20 carbon atoms.) The lanthanum series metal compound (A) The process of claim 1 Symbol placement of modified conjugated diene polymer is a neodymium compound.