JPS6227405A - Production of conjugated diene polymer - Google Patents

Abstract

PURPOSE:To obtain a conjugated diene polymer low in coloration, by using a coordination complex compound of an organoaluminum with an electron- donating compound as the source of Al in the polymerization of a conjugated diene by using a Co-Al-CS2 catalyst. CONSTITUTION:A catalyst system consisting essentially of a cobalt component (A) (e.g., cobalt benzoate), an organoaluminum coordination complex compound (B) of the formula (wherein R is a 6C or lower alkyl, X is a halogen or H, 0<=n<=1 and Y is an electron-donating compound), e.g., triethylaluminum/diethyl ether complex, and a compound (C) selected from among carbon disulfide, phenyl isothiocyanate and a xanthogenic compound (e.g., methyl xanthogenate) is prepared. The purpose conjugated diene polymer is obtained by polymerizing a conjugated diene (e.g., butadiene) in the presence of this catalyst in an aqueous medium or an organic solvent.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a method for producing a conjugated diene polymer.

[Prior art]

As a catalyst for the polymerization of conjugated dienes containing a sulfur compound as one component and using a cobalt compound as a transition metal catalyst, for example, high crystallinity can be obtained by solution polymerization using a catalyst consisting of a soluble cobalt compound, trialkylaluminium, and carbon disulfide. It is known that syndiotactic 1.2 polybutadiene can be obtained (for example, Japanese Patent Publication No. 47-19
Publication No. 892). It is also known that the polymerization of 1°3-butadiene using a microencapsulated aqueous polymerization catalyst consisting of a soluble cobalt compound, trialkylaluminium, and carbon disulfide (Japanese Patent Application Laid-Open No. 78213/1983) can be carried out in an aqueous solvent. ing. However, when 1,3-butadiene is polymerized using these catalysts, the resulting polymer has a drawback that it is colored brownish. In other words, syndiotactic 1,2 polybutadiene is used in sponges, shoe soles, tires, anti-vibration rubber, as well as wrapping films for food packaging, and is an industrially valuable polymer. The product obtained using a catalyst has the disadvantage that the resulting polymer is colored brownish.6 [Object of the Invention] The present invention uses a catalyst system containing a sulfur compound and a cobalt compound to improve the color tone. An object of the present invention is to provide a method for producing an improved polymer.

[Structure of the invention]

According to the present invention (A) a cobalt compound, (B) general formula R
, -nA Q
≦■, Y is an electron-donating compound); and (C) a compound selected from carbon disulfide, phenylisothiocyanate and xanthogen compounds; and (D) a conjugated diene compound. Provided is a method for producing a conjugated diene polymer, which comprises polymerizing a conjugated diene in an aqueous catalyst or an organic solvent.

[Specific Embodiments of the Invention] The present invention will be described in detail below. Examples of the cobalt compound (A) used in the method of the present invention include organic acid salts such as cobalt ofnarate, cobalt naphthate, cobalt benzoate, cobalt shorate, cobalt malonate, and cobalt acetate, cobalt bisacetylacetonate, Cobalt complexes such as cobalt trisacetylacetonate and cobalt acetoacetate ethyl ester, halogens such as triphenylphosphine complexes of cobalt bromide, tri-m-tolylphosphine complexes of cobalt bromide, and tri-m-xylylphosphine complexes of cobalt bromide. Examples include triarylphosphine complexes of cobalt chloride, pyridine complexes of cobalt chloride, pyridine derivative complexes of cobalt halides such as β-picoline complexes of cobalt chloride, and ethyl alcohol complexes of cobalt chloride.

The organoaluminum coordination complex compound of component (B) used in the present invention has the general formula R3-n A fl X n.
Y (wherein, R is an alkyl group having 6 or less carbon atoms.

or a halogen or hydrogen atom, 0≦n≦E, Y is an electron-donating compound).

Preferred halogens for X include chlorine and bromine.

Examples of organic aluminum compounds that can be used in the present invention include dimethylaluminum hydride,
Examples include trimethylaluminum, diethylaluminum chloride, diethylaluminum hydride, triethylaluminum, tripropylaluminum, dipropylaluminium hydride, dipropylaluminum chloride, triisobutylaluminum, diisobutylaluminum chloride, diisobutylaluminum, and the like.

Among these, preferred alkyl groups include ethyl group,
An example is an isobutyl group, and preferred organoaluminum compounds include triethylaluminum, diethylaluminum chloride, triisobutylaluminum, diisobutylaluminum chloride, and diisobutylaluminum hydride.

Examples of electron-donating compounds include ethers and amines.

Ethers include dimethyl ether, diethyl ether, dipropyl ether, dibutyl ether, di-2
- Ethylhexyl ether, diphenyl ether, anisole, etc. can be mentioned. Among these,
Diethyl ether, dibutyl ether, and diphenyl ether are preferred.

Examples of amines include trimethylamine, triethylamine, tributylamine, triphenylamine, dimethylethylamine, diethylmethylamine, and the like. Among these, triethylamine and tributylamine are preferred.

The organoaluminum coordination complex compound (B) is a complex compound of these organoaluminiums and an electron-donating compound,
Any coordination compound can be formed by combining the above-mentioned organoaluminum compound and electron-donating compound.

Examples of organoaluminium coordination complex compounds include triethylaluminum diethyl ether complex, diethylaluminum chloride diethyl ether complex, triisobutylaluminum diethyl ether complex, triisobutylaluminum dibutyl ether complex, triisobutylaluminum diphenyl ether complex, trimethylaluminum trimethylamine complex, triethylaluminum trimethylamine complexes, triethylaluminum triethylamine complexes, triethylaluminum tributylamine complexes, and the like. Among these, triethyl aluminum diethyl ether complex, triethyl aluminum unilum dibutyl ether complex, and tributyl aluminum dibutyl ether complex are preferred. These coordination complex compounds may be isolated and pure, but may be a reaction mixture obtained by adding an organoaluminum compound to an electron donating compound dissolved in an inert solvent such as a hydrocarbon solvent and aging at room temperature, or an organoaluminum compound. The reaction mixture obtained by adding an electron-donating compound to the solution and aging at room temperature may be used as it is.

The isolated coordination complex has a stoichiometric composition, but in the case of a reaction mixture, sufficient effects can be observed even if the composition differs from the stoichiometric composition. In this case, the ratio (mole ratio) of (electron donating compound/organoaluminum compound) is 0.1
to 10, preferably 0.3 to 2. When the amount of the electron-donating compound is smaller than this range, the effect of the present invention is hardly observed. Furthermore, if the amount of the electron-donating compound is greater than this range, the polymerization activity will decrease6 and it is also economically unfavorable.

The use of carbon disulfide and/or phenylisothiocyanate as component (C) used in the present invention is not particularly limited, but it is preferable to remove dissolved oxygen in advance by nitrogen bubbling or the like.

As the xanthogen compound, general formulas include luxanthogenic acid, ethylxanthogenic acid, n-propylxanthogenic acid, isopropylxanthogenic acid, n-
Butyl xanthate, 5ee-butylxanthate, 6-butylxanthate, n-penalxanthate, n-hexylxanthate, n-butylxanthate, n-octylxanthate, 2-ethylhexylxanthate , phenylxanthate, p
- xanthate acids such as tolylxanthate and lithium, sodium, potassium salts of these xanthate acids and dimethylxanthogen disulfide, diethylxanthogen disulfide, di-n-propylxanthogen disulfide, diisopropylxanthogen disulfide, di-n-butylxanthogen disulfide,
Xanthogen disulfides such as di-t-butylxanthogen disulfide, 2-ethylhexylxanthogen disulfide, diphenylxanthogen disulfide, and ethylphenylxanthogen disulfide are preferably used. Among these, particularly preferred are xanthogen disulfides, especially dimethyl xanthogen disulfide, diisopropyl xanthogen disulfide,
Diphenylxanthogen sulfide is preferred.

In the present invention, when a conjugated diene is polymerized in an organic solvent,
Each compound (A), (B), and (C) can be added and polymerized in the presence of a conjugated diene.

Examples of polymerization solvents include aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as pentane, hexane, heptane, and octane, and halogenated hydrocarbons such as methylene chloride, methylene dichloride, trichloroethane, and chlorobenzene. These can be present together from the time of preparation of the catalyst.

In addition, when using a polar solvent such as water or an ester, the compound (A) and the compound CB) are first brought into contact with the conjugated diene compound (D) in the absence of the solvent, and then the solvent It is necessary to bring it into contact with the catalyst. Such polar solvents include water, ester solvents such as ethyl acetate, propyl acetate, butyl acetate, ethyl octylate, caprolactone, and γ-valerolactone; methanol, ethanol, isopropyl alcohol, n-butanol, and
Alcohol solvents such as ec-butanol, octatool, and ethylene glycol; Ketone solvents such as acetone, methyl ethyl ketone, acetophenone, and acetylacetone; Nitrile solvents such as acetonitrile, adiponitrile, and benzonitrile; ε-caprolactam, propiolactam, butyrolactam, The conjugated diene can be polymerized using an amide solvent such as valerolactam, N-methylpyrrolidone, N-ethylpyrrolidone, N-methylformamide, N-ethylformamide, and N,N-dimethylformamide.

The conjugated diene compound of component (D) used here is:
In addition to hydrocarbon compounds such as butadiene, isoprene, and piperylene, ester compounds having an internal conjugated double bond such as methyl sorbate and ethyl sorbate may be mentioned. Among these, butadiene is most preferred.

As a method for catalytic reaction of compounds (A), (B), and (D), compound (A) is added to a hydrocarbon solvent or a halogenated hydrocarbon solvent for compounds (B) and (D). Alternatively, a method may be mentioned in which the compound (B) is added to a hydrocarbon solvent or a halogenated hydrocarbon solvent for the compounds (A) and (D).

The temperature during the catalytic reaction is -78°C to 100°C, preferably -30°C to 50°C.

Hydrocarbon solvents or halogenated hydrocarbon solvents used in the catalytic reaction include aromatic hydrocarbons such as benzene, toluene, and xylene, butane, aliphatic hydrocarbon compounds such as pentane, n-hexane, heptane, cyclohexane, and octane, and methylene chloride. hydrocarbon solvents.

By stirring the solvent and catalyst component as necessary during the catalytic reaction of (A), (B) and (D) compounds, (A)
The reactions of compounds B) and (D) can be carried out uniformly. The contact time of the catalyst components is usually about 5 minutes to 2 hours, although it is influenced by the temperature during the contact reaction.

(D) during catalytic reaction of (A) (B) and (D) compounds
The molar ratio of compound/(A) compound is preferably 1-100, more preferably 6-50.

In addition, the molar ratio of compound (B)/compound (A) is 0°3 to 1
00 is preferable, and 0.9-50 is more preferable.

Component (C) may be added in advance to an aqueous suspension or emulsion of the monomer or monomer solvent, or may be added to an organic solvent, or may be added to the catalytic reaction product of the cobalt compound described above. It may be added to the polymerization system at the same time. Of these, the first method is preferred. The above component (C) is preferably 0.01 to 100 mol, more preferably 0.3 to 1 mol, per 1 mol of cobalt compound (A).
0 mol is preferred.

Further, in the present invention, the polymerization temperature is from 0°C to 80°C, preferably from 5 to 50°C.

The present invention further includes BR, SBR, IR, and EPR.

In addition to solutions of synthetic rubbers such as EPDM and NBR, conjugated dienes are added to polymer solutions obtained by known methods.
The components (A), (B), and (D) may be reacted in advance in a contact reaction, and then the compound (C) may be added for polymerization.

The polymer obtained by the present invention can be used alone or in combination with other rubbers, synthetic resins, etc., and can be used for tires, footwear, etc.
Suitable for films, sponges, anti-vibration rubber, bottles, and other rubber and resin modification materials.

〔Example〕

The present invention will be described below in more detail with reference to Examples, but the present invention is not restricted to these Examples as long as the gist of the present invention is not exceeded.

Example 1 (Preparation of coordination complex compound) Into a flask purged with 100 wQ of nitrogen, 2.0 mol/liter of a methylene chloride solution of dibutyl ether was added.
0 mQ, 1.0 mol/liter of methylene chloride solution of triisobutylaluminum 20 [IIQ was added at 20°C, left for 10 hours, dibutyl ether/triisobutylaluminum = 1/1 (mole ratio) 0.5 mol/ A methylene chloride solution of Ritter's triisobutylaluminum dibutyl ether complex compound was obtained.

(Preparation of catalyst) A Teflon-coated stirring bar and 10 mQ of a 0.20 mol/liter methylene chloride solution of cobalt octylic acid were put into a 300 mQ pressure pin which had been purged with nitrogen in advance, and then the pin was capped. After adding 3.5 mQ of butadiene, place it in a water bath at 0°C, and while rotating the stirrer vigorously.
8 + afl of a methylene chloride solution of 5 mol/liter of triisobutyl aluminum dibutyl ether complex compound was added (AQ/Co (molar ratio) was 2). Approximately 15 of these
The reacted cobalt solution was made into a reacted cobalt solution and used in the following polymerization.

(Polymerization) Add 20OIIQ of distilled water to a 350mQ pressure bottle, and after bubbling with nitrogen for 5 minutes, add 17.7% of butadiene.
g and capped. To this was added 0.20 mmol of carbon disulfide and 10 m12 of ε-caprolactone, 2.15+oQ of reacted cobalt solution (0.20 mmol as cobalt amount), and after vigorous shaking, the polymerization was carried out in a rotating polymerization tank at 15°C. I did it for an hour.

After polymerization, the polymer was collected by filtration using Tetron cloth. After immersion in methanol solution containing anti-aging agent BHT 5
Vacuum drying was performed at 0°C. Yield 9×5%; vinyl content of polymer 85%; T by DSC
II+ is 135°C; intrinsic viscosity in toluene at 30°C is 2
．． 1 (alt/g). The produced 1,2-polybutadiene was in the form of pearls of 3 to 5 maφ, with some large lumps. The color of the polymer was pale yellow.

*DSC: Abbreviation for differential scanning calorimeter. Determined using DuPont Model 900 DSC analyzer. The heating rate was 20° C./min, the sample was 10 μm, and alumina was used as a reference.

The microstructure of the polymer was determined using infrared absorption spectroscopy.
It was calculated using the rero method.

Example 2 (Preparation of coordination complex compound) A coordination complex compound was prepared in the same manner as in Example 1 except that the dibutyl ether/triisobutylaluminum molar ratio in Example 1 was changed to 0.5/1.

(Preparation of catalyst) A catalyst was prepared in the same manner as in Example 1 with AQ/Co (molar ratio)=2.

(Polymerization) Polymerization and post-treatment were carried out in the same manner as in Example 1. Yield is 92
%; vinyl content of the polymer is 83%; Tm by DSC is 130°C; intrinsic viscosity in toluene at 30°C is 2.3 (
dQ/g). The produced 1,2-polybutadiene was in the form of pearls of 3 to 5IIIφ, with some large lumps. The color of the polymer was yellow.

Example 3 (Preparation of coordination complex compound) Triethyl aluminum diethyl ether complex (CH
It was synthesized according to the method of EM, BER, Vol. 91, p. 2446 (1958), and purified by distillation after synthesis. The boiling point is 115
°C/15 +nm Hg. (Literature value 112℃
/ 16 mm Hg) The synthesized triethyl aluminum diethyl ether complex was diluted with cyclohexane to form a 0.5 mol/liter solution.

(Preparation of catalyst) A Teflon-coated stirrer and 0.00% cobalt octylic acid were placed in a 30011In pressure bottle that had been purged with nitrogen in advance.
After adding 10 mQ of a 20 mol/liter cyclohexane solution, the flask was capped. After adding 3.5 rtrQ of butadiene, place in a water bath at 0°C, and while rotating the stirrer vigorously, add 8 mg of a cyclohexane solution of 0.5 mol/liter of triethyl aluminum diethyl ether complex.
added.

(AQ/Co molar ratio is 2) After about 15 minutes of reaction, the reacted cobalt solution was used in the following polymerization.

(Polymerization) E-caprolactone in Example 1 was replaced with ethyl acetate, and polymerization and post-treatment were carried out using the above-mentioned reacted cobalt solution. Yield is 95%; vinyl content of polymer is 89%, DS
Tm by C was 143°C; intrinsic viscosity in toluene at 30°C was 2.5 (cii+/g). Generated 1,
The 2-polybutadiene was in the form of pearls of 3 to 6 IIWIlφ, with some large lumps.

The color of the polymer was pale yellow.

Example 4 Polymerization and post-treatment were carried out in the same manner as in Example 1, except that tributylamine was used instead of dibutyl ether. Yield 78%; polymer vinyl content 81%, DS
The Tm by C was 128°C; the intrinsic viscosity in toluene at 30°C was 2.6 (dQ/g). The 1,2 polybutadiene produced was pearl-like with a size of 3 to 5 IIllφ, with some large lumps. Ta.

The color of the polymer was yellow.

Comparative Example 1 A catalyst was prepared using triisobutylaluminum without using dibutyl ether or forming a coordination complex compound as in Example 1.

(Preparation of catalyst) A Teflon-coated stirring bar and 10+Q of a 0.20 mol/liter methylene chloride solution of cobalt octylic acid were placed in a 300 mQ pressure-resistant bottle that had been purged with nitrogen in advance, and then the bottle was capped. After adding 3.5 mA of butadiene, place it in a water bath at 0°C and while rotating the stirrer vigorously, add 0.5 mA of butadiene.
8n+Q of a methylene chloride solution of triisobutylaluminum in moles/liter was added. (AQ/Co molar ratio is 2
) The reaction was carried out for about 15 minutes.

(overlapping) Polymerization and post-treatment were carried out in the same manner as in Example 1.

The yield was 89%; the vinyl content of the polymer was 83%; T11 by DSC was 133°C; the intrinsic viscosity in toluene at 30°C was 1.9 (dQ/g). The produced 1,2-polybutadiene was in the form of pearls of 2 to 5 Iφ, with some large lumps. The color of the polymer was a dark brownish color.

〔Effect of the invention〕

1.2 Polybutadiene is an industrially valuable polymer that is used in sponges, shoe soles, tires, anti-vibration rubber, as well as wrapping films for food packaging. However, the polymer obtained using the conventional Go-A n -CS2 catalyst retains its deep brown color, which is thought to be due to the polymerization catalyst.

The present invention has succeeded in obtaining a polymer with little coloring by using a coordination complex compound of an organoaluminum and an electron-donating compound as an organoaluminum compound, which is a type of catalyst component. Namely, 1 Examples 1 to 4 of the present invention
By using an organoaluminum ether or amine coordination complex compound as shown in Figure 1, the formation of 1
It has become clear that coloring of ゜2 polybutadiene can be suppressed.

Claims (1)

[Claims] (1) (A) Cobalt compound (B) General formula R_3_-nAlXn・Y (wherein, R is an alkyl group having 6 or less carbon atoms, X is a halogen or hydrogen atom O≦n≦1, Y: electron donating A conjugated diene is produced in an aqueous medium or an organic solvent using a catalyst system containing an organoaluminum coordination complex compound represented by (compound) and (C) a type of compound selected from carbon disulfide, phenylisothiocyanic acid, and a xanthogen compound in an aqueous medium or an organic solvent. A method for producing a conjugated diene polymer, which comprises polymerizing a conjugated diene polymer.