WO2002090396A1

WO2002090396A1 - Sys-1, 4-polybutadiene production method

Info

Publication number: WO2002090396A1
Application number: PCT/JP2002/004525
Authority: WO
Inventors: Tetsuya Toyoshima; Teruhiko Matsuda
Original assignee: Zeon Corporation
Priority date: 2001-05-09
Filing date: 2002-05-09
Publication date: 2002-11-14
Also published as: JPWO2002090396A1; JP3941693B2

Abstract

A sys-1, 4-polybutadiene production method in which 1, 3-butadiene is polymerized by using a catalyst substantially composed of a transition metal compound, an organic aluminum compound, and active hydrogen under presence of a surfactant in an inactive solvent.

Description

TECHNICAL FIELD The present invention relates to a method for producing cis 1,4-polybutadiene, and more specifically, it consists essentially of an organoaluminum compound, a transition metal compound and a compound having active hydrogen. The present invention relates to an improvement in a method for producing cis 1,4-polybutadiene using a polymerization catalyst. BACKGROUND ART Cis 1,4-polybutadiene is widely used as a rubber material for tires or high-impact polystyrene. This polymer is produced by polymerizing 1,3-ptagene using a polymerization catalyst consisting of an organoaluminum compound, a transition metal compound, and water. Although the use of water as a catalyst component has the advantage of increasing the polymerization activity, it has the problem of producing a large amount of gel polymer (hereinafter simply referred to as gel). If a gel is generated during polymerization, it will adhere to the polymerization tank, stirrer, pipes, etc., making it impossible to continue the polymerization reaction for a long time. In addition, when polybutadiene containing a large amount of gel is used for the production of impact-resistant polystyrene, it causes a reduction in the impact resistance of the resin.

Therefore, as a method for suppressing the formation of gel, Japanese Patent Publication No. 57-157665 discloses a method using a hydroquinone-based or phenol-based compound. Japanese Patent Application Publication No. 975/56 proposes a method using thiodipropionic acid diester. However, these gelling inhibitors have no effect unless they are used in large amounts, and on the other hand, there is a problem that the amount of the polymerization catalyst used must be increased since the polymerization activity is reduced. In addition, it adversely affects the vulcanization behavior of the produced polybutadiene. Japanese Patent Application Laid-Open No. H11-222709 discloses that after water and an organoaluminum compound are aged at a specific temperature and time in a polymerization solvent solution of 1,3-butadiene. A method for adding a copart compound has been proposed. However, in this method, the undesired cationic polymer of 1,3-butadiene is formed by the reaction product of water and the organoaluminum compound at the aging stage, and this is insoluble in the polymerization solvent. Before adding the cobalt compound and initiating the polymerization, it is necessary to carry out filtration of the insoluble matter, which causes a problem that the operation at the time of production becomes complicated. DISCLOSURE OF THE INVENTION An object of the present invention is to provide an industrially advantageous method for producing cis 1,4-polybutadiene without lowering the polymerization activity and producing less cationic polymer and gel. .

The present inventors have conducted intensive studies to solve the above-mentioned problems of the prior art, and as a result, by polymerizing 1,3-butadiene in the presence of a surfactant, the formation of a cation polymer and the formation of a gel were achieved. They found that polybutadiene can be produced with high activity while remarkably suppressing them, and based on this finding, the present inventors have completed the present invention.

Thus, according to the present invention, a catalyst consisting essentially of a transition metal compound, an organoaluminum compound and a compound having active hydrogen is used in an inert solvent in the presence of a surfactant. A process for producing cis 1,4-polybutadiene, characterized by polymerizing butadiene, is provided.

In the present invention, the transition metal compound is prepared by mixing an organometallic compound of an element selected from the elements in Groups 1 to 3 and 11 to 13 of the Periodic Table with an inert solvent and then aged in advance. It is preferred to carry out the polymerization using

Further, in the present invention, a mixture of a surfactant and a compound having active hydrogen is added to a solution of 1,3-butadiene in an inert solvent, and then, after addition of an organic aluminum compound, a transition metal compound is added. It is preferable to conduct polymerization BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a transition metal compound, an organoaluminum compound, and a compound having active hydrogen are essentially contained in an inert solvent in the presence of a surfactant. 1,3-butadiene is polymerized using a suitable catalyst.

The transition metal compound is a compound containing an iron group and a platinum group element belonging to Groups 8 to 10 of the periodic table.

As the transition metal compound, a salt-complex of these elements is preferably used. Of these elements, cobalt and nickel are preferred, and cobalt is particularly preferred.

Specific examples of the transition metal compound include, for example, inorganic acid salts such as cobalt chloride, cobalt bromide, and cobalt nitrate; cobalt otatenate, cobalt naphthenate, cobalt acetate, cobalt oxalate, and cobalt versatate (having 1 carbon atom). Organic salts such as the above-mentioned aliphatic monocarboxylic acid cobalt salts having 6 to 20 carbon atoms having a carboxyl group at the tertiary carbon where three alkyl groups are bonded), cobalt malonate, and the like; cobalt bisacetyl acetate toner; Organic base complexes such as cobalt trisacetyl acetate, acetate ethyl acetate coparte, cobalt halide triarylphosphine complex, trialkylphosphine complex, pyridine complex and picolin complex; and the like; Nickel compounds corresponding to these are mentioned. One of these transition metal compounds may be used alone, or two or more thereof may be used in combination.

Among the above transition metal compounds, cobalt hexanoate, cobalt octoate, cobalt stearate, cobalt naphthenate, and nickel compounds corresponding thereto are preferable, and cobalt otatenate is particularly preferable.

The amount of these transition metal compounds to be used is preferably 0.0001 to 1 mol, more preferably 0.05 to 1 mol, per mol of 1,3-butadiene used in the polymerization. Millimoles, particularly preferably 0.1 to 0.1 millimoles Range.

Organoaluminum compounds are compounds in which at least one hydrocarbon group is bonded to an aluminum atom. The hydrocarbon group is not particularly limited, but is preferably an alkyl group, more preferably an alkyl group having 1 to 10 carbon atoms, and particularly preferably an alkyl group having 2 to 4 carbon atoms.

Specific examples of the organoaluminum compound include, for example, getyl aluminum monochloride, getinolea / reminimum monobromide, dibutinorea remoleum monochloride, and dicyclohexylamine monochrome. Halogen-containing organic aluminum compounds such as light, diphenylenoleuminium monochloride, etinoleanolinium sesquique mouth light, ethyl aluminum zinc mouth light, etc .; trimethyl aluminum, triethyl aluminum aluminum, Alkyl aluminum compounds such as triisopropylaluminum and triisopropylethyl; and organic aluminum hydrides such as getylaluminum hydride and ethylaluminum sesquihydride. Among these, a halogen-containing organic aluminum compound and an alkyl aluminum compound are preferred, and getyl aluminum monochloride, ethyl aluminum sesquique mouth ride, ethyl aluminum zinc mouth ride, and triisobutyl aluminum are more preferred. Especially preferred is Jechil aluminum monochrome.

These organoaluminum compounds can be used alone or in combination of two or more.

The amount of the organoaluminum compound to be used is preferably from 0.01 to 10 mol, more preferably from 0.1 to 5 mol, particularly preferably from 0.1 to 10 mol, per mol of 1,3-butadiene used in the polymerization. It is in the range of 3 to 2 millimoles.

Examples of the compound having active hydrogen include water; lower alcohols such as methanol and ethanol; carboxylic acids such as formic acid, acetic acid and benzoic acid; and amine compounds such as ammonia and aniline. But water is preferred. The compound having active hydrogen is a component used for stably improving the catalytic activity. The amount used is 0.1 mol per mol of the organoaluminum compound. It is preferably in the range of 1 to 0.8 mol.

The method of adding the transition metal compound, the organoaluminum compound and the compound having active hydrogen used as the catalyst component is not particularly limited, and may be added simultaneously to an inert solvent or a solution of 1,3-butadiene in an inert solvent. You may add sequentially. Among them, it is preferable to sequentially add each of the above components to the inert solvent solution.

When each component is added sequentially, the order of addition is not particularly limited, but it is particularly preferable to add the compound having active hydrogen, the organoaluminum compound, and the transition metal compound in this order. In adding each component, the organic aluminum compound and the transition metal compound are preferably added as a solution having a concentration of 1 to 20% by weight of an inert solvent used for polymerization.

The most preferable method for adding each component is to add a compound having active hydrogen to a solution of 1,3-butadiene in an inert solvent, add an organoaluminum compound, and then add a transition metal compound.

In this case, after adding the compound having active hydrogen, the time required for the compound having active hydrogen to sufficiently diffuse into the solution of 1,3-butadiene in an inert solvent, preferably 1 second to 1 second It is preferable to add the organoaluminum compound after 0 minutes have passed, and, after the addition of the organoaluminum compound, the time until the compound having active hydrogen and the organoaluminum compound sufficiently react, preferably It is preferable to add the transition metal compound after 1 second or more, more preferably 1 minute or more, and still more preferably 3 minutes or more.

The temperature at which the catalyst component is added is usually in the range of 0 to 100 ° C, preferably in the range of 10 to 60 ° C.

In the present invention, the polymerization is performed in an inert solvent.

The inert solvent is not particularly limited as long as it dissolves cis 1,4-polybutadiene and does not adversely affect the activity of the polymerization catalyst.

Specific examples thereof include aromatic hydrocarbons such as benzene, toluene, and xylene; and aliphatic hydrocarbons such as n-butane, n-pentane, _n- hexane, and n-heptane. Alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, and cyclopentane; olebuin-based hydrocarbons such as cis-1-butene and trans-1-butene; halogenations such as methylene chloride and carbon tetrachloride Hydrocarbon; and the like. These inert solvents can be used alone or in combination of two or more. The amount of the inert solvent to be used is not particularly limited, but it is used so that the 1,3-butadiene concentration is preferably in the range of 5 to 50% by weight, more preferably 10 to 35% by weight.

In the present invention, the transition metal compound is mixed in an inert solvent with an organometallic compound of an element selected from Group 1 to 3 and 11 to 13 of the Periodic Table, and aged in advance. It is preferable to use those that have been used.

By using a transition metal compound subjected to such aging treatment, it is possible to produce cis 1,4-polybutadiene with higher activity while suppressing the generation of gel.

As the inert solvent, it is preferable to use the same solvent as that used for the polymerization of 1,3-butadiene.

The elements of Groups 1 to 3 and Groups 11 to 13 of the Periodic Table are not particularly limited, and mosquitoes, among them, lithium, magnesium, aluminum, and boron are preferred.

Specific examples of the organometallic compounds of these elements include, for example, the above-mentioned organoaluminum compounds, methyllithium, butyllithium, neopentyllithium, benzyllithium, trimethylsilylmethyllithium, bistrimethylsilylmethyllithium, etc. Organic lithium compounds; organic magnesium compounds such as dibutylmagnesium and dihexylmagnesium; and organic zinc compounds such as dimethylzinc and methylzinc. These organometallic compounds can be used alone or in combination of two or more.

Of these organometallic compounds, organoaluminum compounds are preferred, trialkylaluminum compounds are more preferred, and triisobutylaluminum is particularly preferred.

The mixing ratio of the organometallic compound and the transition metal compound is: transition metal compound 1 The aforementioned organometallic compound is used in an amount of preferably 0.05 to 5 mol, more preferably 0.1 to 2 mol, particularly preferably 0.2 to 0.9 mol, per mol. If the ratio is too small, the gel content in the polymer tends to increase, while if it is too large, the polymerization activity tends to decrease.

When mixing both components, it is preferable to mix them so that the concentration of the transition metal compound in the inert solvent is in the range of 0.1 to 10% by weight, preferably 0.5 to 5% by weight.

The aging is carried out at a temperature of usually from 0 to 80 ° C, preferably from 10 to 40 ° C, usually from 0.1 to 24 hours, preferably from 1 to 20 hours, after mixing both components.

In the present invention, it is essential to carry out the polymerization in the presence of a surfactant. Although the surfactant is not particularly limited, a nonionic surfactant, an anionic surfactant, a cationic surfactant, or the like can be used, and among them, a nonionic surfactant, an iron Nonionic surfactants are preferred, and nonionic surfactants are more preferred.

Nonionic surfactants include, for example, a block condensation polymer of two or more alkylene oxides such as oxyethylene oxypropylene block polymer; lauryl anolecol, cetyl alcohol, stearyl phenol Higher alcohols having 5 to 50 carbon atoms, such as Anorekonore and Oleylanorechol, etc. Polyoxyethylene peryl ether, polyoxyethylene cetyl 'ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene terephenyl ether Polyxylene / alkylene ether compounds such as polyxylene ethylene / lefeninoleate / le; alkylene oxides to higher fatty acids having 5 to 50 carbon atoms such as lauric acid, palmitic acid, stearic acid, and oleic acid Polyoxyethylene glycol monolaurate, polyoxyethylene glycol monopalmitate, polyethylene glycol monostearate, polyethylene glycol distearate, polyethylene glycol monoremo Polyoxyalkylene glycol fatty acid ester-based compounds such as phenols;

An ester compound of a polyhydric alcohol having three or more hydroxyl groups in a molecule such as glycerin, pentaerythritol tonole, sonorebitan, manethane, hexitane, or a polycondensate thereof and a higher fatty acid having 5 to 50 carbon atoms. Certain dariseri monoreostate, glyceryl monooleate, sonorebitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan distearate, so ^ / bitan tristearate, sonorebitan monolate Rate, Sorbitandiolate, Mannitan monolaurate, Mannitan monostearate, Mannitan distearate, Mannitan monooleate, Hexitane monolaurate, Hexitane monono, V Remitate , Hexitan monostearate, Polyhydric alcohol-based fatty acid ester compounds such as citane distearate, hexitane tristearate, hexitan monooleate, and hexitane dioleate; alkylene oxide is used as the polyhydric alcohol-based fatty acid ester compound. Polyoxyethylene sorbitan monoperate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan distearate, polyoxyethylene sonolebitan monooleate, polyoxyethylene mannitan monopalmitate Polyoxyethylene Manthane Monostearate, Polyoxyethylene Mannitane Monoester, Polyoxyethylene Hexitane Monolate, Polyoxyalkylene such as Polyoxyethylene Hexitane Monostearate Polyhydric alcohol fatty acid ester compounds, polyoxyethylene stearyl § Mi emissions, poly O xylene alkylether § amine compounds such Poriokishechire Noreiruamin; al Kiruaru force Noruami de compounds; and the like.

Among them, block condensation polymers of two or more alkylene oxides, polyoxyalkylene ether compounds, polyoxyalkylene glycol fatty acid ester compounds, and polyoxyalkylene polyhydric alcohol fatty acid esters Polyoxyalkylene compounds such as ter compounds and polyoxyalkylene alkylamine compounds are preferred. Polymer, polyoxyethylene peryl ether, polyoxyethylene stearyl ether, polyoxyethylene nourphenyl ether, polyethylene glycol monostearate, polyoxyethylene sonolebitan monostearate, polyoxyethylene stearylamine Particularly preferred.

Examples of the anionic surfactant include carbon numbers such as sodium laurate, sodium myristate, sodium palmitate, sodium stearate, potassium stearate, sodium oleate, and potassium oleate. Fatty acid salts of 5 to 50; higher alcohol sulfates of 5 to 50 carbon atoms, such as sodium radium sulfate; liquid fatty acid sulfates, such as sodium salt of dodecylsulfoacetate; sodium salt of oleyltaurine Sulfates of aliphatic amines or aliphatic amides having 5 to 50 carbon atoms, such as N-methyloleate sodium salt; aliphatics having 5 to 50 carbon atoms, such as sodium dodecyl phosphate Alcohol phosphate salts; di (2-ethylhexyl) sulfosuccinate sodium salt What dibasic fatty E ester sulfonic acid salts; naphthalenesulfonic acid sodium Umushio and _c and aromatic sulfonates such as dodecyl base Nzensuruhon acid sodium © beam salts, which are used in the form of the free acid You may.

As the anionic surfactant, a polymer type anionic surfactant can be used. Examples thereof include polycarboxylic acids and salts thereof; sulfonic acid group-containing polymers and salts thereof; carboxymethyl cellulose, and alginic acid. And other anionic polymers such as soda, lipstick and the like.

Examples of the polycarboxylic acids and salts thereof include polymers of (meth) atalilic acid and salts thereof; polymers of unsaturated dibasic acids such as maleic anhydride, maleic acid, fumaric acid, and itaconic acid, and other monomers. And salts thereof and the like. Examples of the sulfonic acid group-containing polymer include, for example, lignin sulfonic acid, formalin condensate of (alkyl) naphthalene sulfonic acid, honole marin condensate of (alkynole) benzene sulfonic acid and formalin condensate of sulphonate of creosote oil Formalin condensates of aromatic sulfonic acids, such as products, and polymers of vinyl sulfonic acids. Among these anionic surfactants, higher alcohol sulfates, aromatic sulfonic acids, polycarboxylic acids and salts thereof are preferable, and sodium lauryl sulfate and sodium dodecylbenzene sulfonate are particularly preferable. It is good.

Cationic surfactants include, for example, aliphatic amine salts; lauryl trimethylammonium mouthride, stearyltrimethylammonium mouthride, cetyltrimethylammonium mouthride, distearyldimethylammonium Quaternary ammonium salts such as -muk mouth ride; alkylpyridinium salts; polyoxyethylene alkylamine salts; and imidazoline derivatives.

In addition, cationic polymers such as polyvinylpyridine-based polysoap, acrylic ester-based cationic activator, and polyacrylamide-based cationic activator can also be used.

These surfactants may be used alone or in combination of two or more.

The amount of the surfactant used is preferably from 0.01 to 50 parts by weight, more preferably from 0.05 to 30 parts by weight, based on 100 parts by weight of the compound having active hydrogen used for the catalyst. Parts, particularly preferably 0.1 to 10 parts by weight. If the amount of the surfactant is excessively small, the amount of the cationic polymer produced and the amount of the gel in the polybutadiene increase, and if the amount is excessive, the polymerization activity tends to decrease. The method of adding the surfactant is not particularly limited, but may be added to the inert solvent or a solution of 1,3-butadiene in the inert solvent together with the above-mentioned catalyst component, or may be added separately. Among them, it is preferable to add the surfactant and the catalyst component together, and it is more preferable to add the surfactant and the compound having active hydrogen as a mixture.

When a mixture of a surfactant and a compound having active hydrogen is added to an inert solvent or a solution of 1,3-butadiene in an inert solvent, the mixture is added through a porous filter medium to further improve the gelation suppressing effect. Is preferred. The material of the filter medium is not particularly limited, and may be stainless steel, steel, brass, nickel-based. Examples include heat-resistant alloys, carbon, graphite, alundum, silica, and porcelain. The filter medium is obtained by sintering these materials.

The pore size of the filter medium is preferably 5 microns or less, more preferably 2 microns or less.

According to the method of the present invention, it is possible to obtain cis-1,4-polybutadiene having almost no gel. However, if desired, a gelation inhibitor can be further used.

Specific examples of the gelation inhibitor include, for example, diester compounds of thiodipropionic acid such as dilauryl-1,3,3-thiodipropionate and distearyl-1,3,3-thiodipropionate; 4,4′-thiobis ( Phenol compounds such as 3-methyl-6-t-butylphenol, 2,5-dibutylbutyrohydroquinone, and 2,5-dibutylamylhydroquinone; trimethylphosphate, triethynolephosf: — Phosphoric acid triester compounds such as trimethyl phosphate, trimethyl phosphate, triethyl phosphite, tributyltin phosphite, tributyl phosphite, triphenyl phosphite, tris / Re) Phosphorous acid triester compounds such as phosphites; thiourea, N, N-methylthiourea, N, Thiourea compounds such as N_dibutylthiourea and N, N-diphenylthiourea; thiols such as n-octylmercaptan, n-dodecylmercaptan, t-dodecylmercaptan, and 2-mercaptobenzothiazoyl Olenoester compounds such as trimethyl orthoformate, triethyl orthoformate, trimethyl orthoacetate, triethyl orthoacetate, trimethyl orthobutyrate, and triethyl orthobutyrate; dimethyl phenylephosphonate, Phenylphosphonic acid diester compounds such as getyl phosphonate; and the like.

Among them, an orthoester compound and a phenol phosphonate ester compound are preferred, and trimethyl orthoformate and dimethyl phenylphosphonate are more preferred. These gelling inhibitors can be used alone or in combination of two or more.

The amount of the gelling inhibitor used is, per mole of 1,3-butadiene used in the polymerization, Preferably it is in the range of 0.002 to 0.06 mol.

In the present invention, if necessary, a molecular weight regulator generally used in a method for producing cis-1,4-polybutadiene can be used.

Specific examples of the molecular weight regulator include, for example, α-olefin compounds such as 1-butene and 1-pentene; terminal acetylene compounds such as 1-butyne; internal acetylene compounds such as 2-hexyne and 3-hexyne; Allene conjugates such as provadene, 1,2-butadiene and 1,2-pentadiene; non-available compounds such as 1,4-pentadiene, 1,5-pentadiene, 1,5-cyclooctadiene, norbonolenadiene and dicyclopentadiene A conjugated diene compound; and the like. Among them, allene compounds and cyclic non-conjugated diene compounds are preferred, and propagene, 1,2-butadiene, 1,2-pentadiene and 1,5-cyclooctadiene are more preferred. These molecular weight regulators can be used alone or in combination of two or more.

The polymerization reaction may be a batch type or a continuous type. The polymerization temperature is usually in the range of 0 to 100 ° C, preferably 10 to 60 ° C. The polymerization pressure is usually in the range from 0 to 0.5 MPa (gauge pressure).

After completion of the reaction, a polymerization terminator such as alcohol, an antioxidant, an antioxidant, an ultraviolet absorber, etc. are added to the reaction mixture, and then the produced polymer is separated, washed and dried according to a conventional method to obtain the desired polybutadiene. be able to.

According to the method of the present invention, cis-1,4-polybutadiene having an extremely small amount of gel and having a cis-1,4 bond amount of 90% or more, preferably 95% or more, can be obtained with high polymerization activity. The cis-1,4-polybutadiene can be suitably used as a rubber raw material for improving the impact resistance of a crosslinked rubber such as a tire or a vibration-proof rubber or a thermoplastic resin.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. Parts and percentages in the following are by weight unless otherwise specified. The measurement of various physical properties was performed according to the following methods.

(1) The gel content of the polybutadiene rubber was measured according to the following procedure, and indicated as the number of gels per 5 g of the polybutadiene rubber. 5 g of polybutadiene rubber was dissolved in 250 ml of xylene and filtered under reduced pressure through a 7 cm diameter Buchner funnel fitted with No. 2 filter paper (manufactured by Toyo Roshi Kaisha, Ltd.). After filtration, the xylene solution of Sudan III was sprayed on the filter paper, dried at room temperature, and the number of red colored gels with a diameter of 0.1 mm or more was counted with the naked eye, and the number was indicated as the number of gels .

(2) The number average molecular weight of the polymer was measured by gel permeation.chromatography (GPC), and the number average molecular weight in terms of standard polystyrene was determined. GPC is HLC-820 (Toso-I) and GMH-HR-H and G7000 (all from Toso-I) are used as columns. Differential refraction is used for detection. This was performed using a total of R 1-8020 (manufactured by Tosoh Corporation).

(3) The solution viscosity was 25 using polybutadiene rubber as a 5% styrene solution. C was measured using an Ostwald viscometer.

(4) The amount of cationic polymer produced was represented by the number of times the filter strainer was switched. The larger the number of times of switching, the larger the generation of the cationic polymer. The following surfactants were used in the examples.

Surfactant A: oxyethylene oxypropylene block polymer (Asahi Denka; pull mouth nick L-64)

Surfactant B: Polyoxyethylene lauryl ether (Kao Corporation; Emulgen 104P)

Surfactant C: polyoxyethylene stearylamine (manufactured by Kao Corporation; Ameat 105)

Surfactant D: sodium dodecylbenzenesulfonate

(Example 1)

Two stainless polymerization reactors equipped with a stirrer, cooling jacket and reflux condenser were connected in series, and continuous polymerization was performed as follows. 1,3-butadiene 34%, toluene 11%, cis-1-butene 40%, trans-2-butene 9%, containing 6% of other inert hydrocarbons such as n-butane, 1,3 — While flowing the butadiene mixture through the pipe at a flow rate of 70 kg / h, 800 mmol / h of 1,2-butadiene, 5 mmol / h of trimethyl orthoformate, and pores A 5% aqueous solution of surfactant A was added through a sintered stainless steel filter having a diameter of 2 μm for 2.5 _§ / hour and dispersed. To this mixture was further added 350 mmol / h (as a toluene solution) of getyl aluminum monochloride per hour, and the mixture was mixed and dispersed with a static mixer. Place the 80-mesh metal filter strainer in a position where the average residence time of the mixture between the static mixer and the metal filter strainer is 5 minutes, and place the mixture in this metal filter strainer. To the polymerization reactor. Differential pressure gauges were installed before and after this metal filter so that when the differential pressure became 350 kPa or more, it was possible to continuously switch to a spare strainer.

From a separate pipe, 28 g of a 3% cobalt otate solution in toluene was added to the polymerization reactor every hour, and continuous polymerization was performed at 20 ° C. and residence time of 2 hours for 120 hours. The polybutadiene solution generated from the second reactor was continuously withdrawn, and a 15% toluene solution of 2,4-bis (n-octylthiomethyl) -16-methylphenol was added as an antioxidant every hour. 140 g of methanol and 36.2 g of methanol were added per hour to completely stop the polymerization reaction. Polybutadiene was recovered from the obtained rubber solution by steam stripping, and dried with hot air at 80 ° C. for 1 hour. Table 1 shows the gel content, number average molecular weight, and solution viscosity of the obtained polybutadiene, the polymerization conversion rate, and the number of times the metal filter strainer was switched within a continuous polymerization time of 120 hours.

(Examples 2 and 3)

Continuous polymerization was performed under the same conditions as in Example 1 except that the concentration of the surfactant A aqueous solution used in Example 1 was changed to 10% and 20%. Table 1 shows the results.

(Example 4)

Continuous polymerization was carried out under the same conditions as in Example 1 except that the trimethyl orthoformate used in Example 1 was not added. Table 1 shows the results.

(Examples 5 to 7)

Continuous polymerization was performed under the same conditions as in Example 1 except that surfactants B to D were used instead of surfactant A of Example 1. Table 1 shows the results.

(Comparative Example 1) Continuous polymerization was performed under the same conditions as in Example 1 except that only water was added instead of adding the aqueous solution of surfactant A used in Example 1. Table 1 shows the results. (Example 8)

While flowing the 1,3-butadiene mixture through the pipe at a flow rate of 70 kg / h, 580 mmol / h of 1,2-butadiene, 5.3 mmol / h of trimethyl orthoformate, and surfactant A 2.3 g / h of a 5% aqueous solution and 230 mmol / h of getyl aluminum monochloride (as a toluene solution) were added in the same manner as in Example 1 and introduced into the polymerization reactor.

Separate pipes into the polymerization reactor were charged with 70 g of trisobutylaluminum 10% toluene solution and 650 g of cobalt otate 3% solution of toluene in 15 L of stainless steel with a stirrer. 36.4 g of an aging solution aged for 8 hours in an aging tank was added per hour, and continuous polymerization was carried out at 20 ° C. and residence time of 2 hours for 120 hours. The recovery of polybutadiene was performed in the same manner as in Example 1. Table 1 shows the results.

(Comparative Example 2)

Continuous polymerization was carried out under the same conditions as in Example 8, except that only water was added instead of adding the aqueous solution of surfactant A used in Example 8. Table 1 shows the results. (Example 9)

While flowing the 1,3-butadiene mixture through the pipe at a flow rate of 70 kg / h, 3.2 g / h of a 5% aqueous solution of surfactant A and 377 h / h of getyl aluminum monochloride Millimol (as a toluene solution) was added in the same manner as in Example 1 and introduced into the polymerization reactor.

10.5 g / h of a toluene solution of nickel naphthenate (concentration: 3% in nickel) was added per hour to the polymerization reactor from another pipe, and continuous polymerization was continued for 120 hours at 20 ° C and a residence time of 2 hours. went. The recovery of polybutadiene was performed in the same manner as in Example 1. Table 1 shows the results.

(Comparative Example 3)

Continuous polymerization was performed under the same conditions as in Example 9 except that only water was added instead of adding the aqueous solution of surfactant A used in Example 9. Table 1 shows the results. Table 1 Example Comparative example

1 2 3 4 5 6 7 8 9 1 2 3 Transition metal type Co Co Co Co Co Co Co Co Ni Co Co Ni Maturation of transition metal compound

N / A N / A N / A N / A N / A N / A N / A N / A N / A N / A Surfactant type Δ A Δ A R c π A Δ K f 卜 f ½ 5 1 1 o 2Ω 5 5 5 5 5 5 Ant, acid Ρ3ίtrim 11 + na 1 r i 4- I I t r f

Yes Yes Yes Yes Yes Yes Yes Yes Yes

Switch strainer • i ^ Ί

1 1 0 5 2 1 3 2 1 10 1 o 1 1 times (times) Number of gels (pieces) 1 0 2 2 1 0 2 1 1 43 74 62 Polymerization conversion (%) 54 53 47 55 46 48 56 36 54 56 37 Number average molecular weight 189 191 189 193 192 188 188 187 229 21 192 231 23 (X 1,000) Solution viscosity (mPa) 98 99 97 95 98 94 95 135 4. 6 98 132 4.8

Table 1 shows the following.

In Comparative Examples 1 to 3 where no surfactant was added, both the number of gels and the number of times the filter strainer was switched were large.

On the other hand, in Examples 1 to 9 in which a surfactant was added, both the number of times the filter strainer was switched and the number of gels were reduced without lowering the polymerization activity and physical properties. It is clear that the generation of is suppressed. Industrial applicability

According to the present invention, there is provided an industrially advantageous method for producing cis 1,4-polybutadiene without lowering the polymerization activity and producing less cationic polymer or gel. By carrying out the method of the present invention, adhesion of a gel or scale to a polymerization reaction tank, a stirrer or a pipe is reduced, and a long-term continuous operation can be performed. In addition, the obtained cis 1,4-polybutadiene contains substantially no gel, so that the use of polybutadiene is not limited.

Claims

The scope of the claims

1. Polymerization of 1,3-butadiene using a catalyst consisting essentially of a transition metal compound, an organic aluminum compound and a compound having active hydrogen in an inert solvent in the presence of a surfactant. A characteristic method for producing cis 1,4-polybutadiene.

2. The production method according to claim 1, wherein the surfactant is used in an amount of 0.01 to 50 parts by weight based on 100 parts by weight of the compound having active hydrogen.

3. The method according to claim 1, wherein the surfactant is a nonionic surfactant.

4. As a transition metal compound, an inert metal is mixed with an organometallic compound of an element selected from Groups 1 to 3 and 11 to 13 of the Periodic Table and aged beforehand. 2. The production method according to claim 1, wherein the polymerization is carried out.

5. One mole of the transition metal compound is mixed with an organometallic compound of an element selected from Groups 1 to 3 and 11 to 13 of the periodic table in a range of 0.05 to 5 moles. The production method according to range 4.

6. A mixture of a surfactant and a compound having active hydrogen is added to a solution of 1,3-butadiene in an inert solvent, and then an organoaluminum compound is added, and then a transition metal compound is added for polymerization. The method according to claim 1.

7. The method according to claim 6, wherein the mixture of the surfactant and the compound having active hydrogen is added to a solution of 1,3-butadiene in an inert solvent through a porous filter medium having a pore size of 5 microns or less. Production method.

8. The transition metal compound is used in the range of 0.001 to 1 mmol and the organoaluminum compound in the range of 0.01 to 10 millimol per 1 mol of 1,3-butadiene used for the polymerization. 2. The method according to claim 1, wherein the compound having active hydrogen is used in an amount of 0.1 to 0.8 mol per 1 mol of the compound. "

9. The production method according to claim 1, further comprising a gelling inhibitor.

10. If the transition metal compound is a cobalt compound or a nickel compound, The production method according to claim 1.

11. The method according to claim 10, wherein the transition metal compound is a cobalt compound.