JPS6129606B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polybutadiene using a novel catalyst. Copolymers obtained by radical polymerization of polybutadiene added to styrene monomers have improved impact resistance in addition to the excellent properties of polystyrene, and are therefore widely commercially available as impact-resistant polystyrene resins. The polybutadiene used to produce this impact-resistant polystyrene resin generally has a cis-1,4 structure content obtained by polymerizing 1,3-butadiene using an alkyl lithium as a catalyst.
30-35%, trans 1,4-structure content 50-60
%, polybutadiene with a 1,2 structure content of 10 to 20% (low cis polybutadiene) and cis-1,4 structure content obtained by polymerizing 1,3-butadiene with a cobalt or nickel catalyst.
~98%, trans-1,4 structure content 1-2
%, 1,2 structure content is 1 to 2% (high cis polybutadiene). Since the above-mentioned low-cis polybutadiene has a high glass transition point (usually -70°C), the impact-resistant polystyrene resin obtained using this low-cis polybutadiene is not fully satisfactory in terms of impact resistance. On the other hand, the above-mentioned high cis polybutadiene is 1,2
Due to the low structural content of 1 to 2%, the reactivity with styrene monomers (graft reactivity) is low, and impact-resistant polystyrene resins obtained using high-cis polybutadiene are also sufficiently satisfactory in terms of impact resistance. It has some disadvantages. In addition, as the properties of polybutadiene, the above 1,
In addition to the content of 2-structure or cis-1,4 structure, it is important that the molecular weight is high. Impact-resistant polystyrene resins obtained using low-molecular-weight polybutadiene are not fully satisfactory in terms of impact resistance because the rubber properties of polybutadiene are not expressed. When an organic phosphorus compound or an organic sulfur compound is added as a fourth component to a catalyst system of a cobalt compound, a halogen-containing organoaluminum compound, and water for the production of high-cis polybutadiene, the content of 1,2 structures is generally relatively high. A high amount of polybutadiene can be obtained. However, as the 1,2 structure content increases, the molecular weight decreases, resulting in a nearly liquid form that cannot be practically used as a rubber (for example, JP-A-50-91689). The catalyst system of the present invention consists of (a) a cobalt compound, (b) a halogen-containing organoaluminum compound, (c) water or a polyhydric alcohol, and (d) dithiocarbamic acids as a fourth component. When 1,3-butadiene is polymerized using this catalyst system, polybutadiene with a relatively high content of both cis-1,4 and 1,2 structures and a high molecular weight can be obtained. It will be done. This polybutadiene is suitably used as the polybutadiene for producing the above-mentioned impact-resistant polystyrene resin. If the method of the present invention is used, the content of each structure in polybutadiene will vary depending on the polymerization conditions, such as 1,2 structure content of 4 to 50%, preferably 5 to 20%, cis-1, cis-1,
4 structure content of 48 to 96%, preferably 80% or more,
The trans-1,4 structure content can be varied within a range of 2% or less. Further, the intrinsic viscosity [η] (toluene, 30°C) of polybutadiene can be varied within the range of 1 to 10, preferably 1.5 to 7. Cobalt compounds as catalyst components used in the polymerization reaction of the present invention include cobalt β-diketone complexes such as cobalt () acetylacetonate and cobalt () acetylacetonate, and cobalt β-keto complexes such as cobalt acetoacetic acid ethyl ester. Acid esters, cobalt octoate, cobalt naphthenate, cobalt benzate, etc. with 6 carbon atoms
Cobalt salts of the above organic carboxylic acids, cobalt chloride pyridine complexes, cobalt halide complexes such as cobalt chloride ethyl alcohol complexes, and the like can be mentioned. The halogen-containing organoaluminum compound has _the general formula _{AlR o} The compound represented by Examples of halogen-containing organoaluminum compounds include diethylaluminum monochloride, diethylaluminum monobromide,
Examples include dialkyl aluminum halides such as diisobutylaluminum monochloride and alkyl aluminum sesquihalides such as ethylaluminum sesquichloride. Examples of polyhydric alcohols include dihydric alcohols such as ethylene glycol, propylene glycol, trimethylene glycol, α-butylene glycol, β-butylene glycol, and tetramethylene glycol, and trihydric alcohols such as glycerin. Dithiocarbamic acids have the general formula (R is hydrogen or an alkyl group having 1 to 10 carbon atoms,
phenyl group, cycloalkyl group, or pentamethylene group) and salts thereof, such as dimethyldiocarbamic acid, diethyldithiocarbamic acid, dibutyldithiocarbamic acid, pentamethylenedithiocarbamic acid, and their respective ammonium salts and amine salts. can be mentioned. When 1,3-butadiene is polymerized using a catalyst obtained from a cobalt compound, a halogen-containing organoaluminum compound, water (or polyhydric alcohol), and dithiocarbamic acids, 1,3-butadiene alone is used as the monomer. Alternatively, up to 50% by weight (preferably up to 20% by weight) of 1,3-butadiene can be replaced with isoprene, 1,3-pentadiene, 2,3-dimethyl-
1,3-butadiene or the like may be used instead. The amount of catalyst used for 1,3-butadiene polymerization is:
The cobalt compound is preferably at least 0.001 mmol, particularly preferably at least 0.005 mmol, per mole of 1,3-butadiene. The molar ratio of cobalt compound to halogen-containing organic aluminum (Co/Al) is preferably from 1:5 to 1:1000, particularly from 1:15 to 1:500. The molar ratio of cobalt compound to dithiocarbamic acid compound is preferably 1:0.01 to 1.20, particularly 1:0.1 to 1.10. The molar ratio of water (or polyhydric alcohol) to halogen-containing organic aluminum is preferably from 0.01:1 to 1:1, particularly from 0.1:1 to 0.5:1. When polymerizing 1,3-butadiene, aromatic hydrocarbons such as benzene, toluene, and xylene, butane, butene, n-heptane,
The polymerization may be carried out in a polymerization solvent such as an aliphatic hydrocarbon such as n-hexane or n-octane, or an alicyclic hydrocarbon such as cyclohexane or methylcyclohexane. The polymerization temperature of 1,3-butadiene is 5 to 100℃,
In particular, the temperature is preferably 20 to 80°C, and the polymerization pressure may be normal pressure or higher. When polymerizing 1,3-butadiene, known molecular weight modifiers, such as non-conjugated dienes such as cyclooctadiene and allene, or α-olefins such as ethylene, propylene, styrene, and butene-1, can be used. . After the polymerization reaction is completed, polybutadiene can be removed by adding an antiaging agent and treating with alcohol, hot water or water in a known manner. The polybutadiene of the present invention can be produced by, for example, a mixture of 2 to 25 parts by weight, preferably 2 to 20 parts by weight, of polybutadiene and 75 to 98 parts by weight, preferably 80 to 98 parts by weight of styrene. An impact-resistant polystyrene resin can be obtained by radical polymerization, preferably by bulk suspension method. Alternatively, the polybutadiene of the present invention exhibits excellent properties when blended as is with styrene-butadiene rubber (SBR) and used for tire tread. Example 1 Add 62 g of 1,3-butadiene to 200 ml of benzene, then add 0.44 mmol of water and stir at 30°C for 30 minutes to dissolve the water. Then diethylaluminum monochloride
After sequentially adding 1.56 mmol, 0.015 mmol of diethyldithiolbamic acid diethylamine salt (hereinafter abbreviated as ()) and 0.02 mmol of cobalt octenoate, the mixture was stirred at 30°C for 30 minutes to polymerize 1,3-butadiene. After the polymerization reaction, add 2,6 to the polymerization solution.
-0.1% ditert-butyl-4-methylphenol
Add a large amount of methanol and dry the precipitate under reduced pressure at room temperature for 24 hours to obtain 19.05 g of polybutadiene.
I got it. This polybutadiene has a 1,2 structure content of 50%, a cis-1,4 structure content of 93.0%, a trans-1,4 structure content of 20%, and an intrinsic viscosity [η] (toluene, 30°C , hereinafter the same) was 5.28. Examples 2, 3, 4, Comparative Example 1 A polymerization reaction was carried out in the same manner as in Example 1 except that the amount of compound () was changed. The results obtained are shown in Table 1.

[Table] Example 5 Polybutadiene was prepared in the same manner as in Example 2, except that 0.01 mmol of cobalt octenoate was used.
11.55g was obtained. This polybutadiene is cis-
The 1,4 structure content was 89.7%, the trans-1,4 structure content was 1.0%, the 1,2 structure content was 9.3%, and the intrinsic viscosity [η] was 6.54. Examples 6 and 7 A polymerization reaction was carried out in the same manner as in Example 5 except that the polymerization temperature was changed. The results obtained are shown in Table 2.

[Table] Example 8 8.95 g of polybutadiene was obtained in the same manner as in Example 6 using 0.66 mmol of water. This polybutadiene had a cis-1,4 structure content of 88.5%, a trans-1,4 structure content of 1.4%, a 1,2 structure content of 10.1%, and an intrinsic viscosity [η] of 4.17. Example 9 Polybutadiene 15.28 was prepared in the same manner as in Example 6, except that 0.01 mmol of dibutyldithiocarbamic acid dibutylammonium salt (abbreviated as ()) was used instead of compound () as the dithiocarbamic acid compound.
I got g. This polybutadiene had a cis-1,4 structure content of 92.8%, a trans-1,4 structure content of 1.1%, a 1,2 structure content of 6.1%, and an intrinsic viscosity [η] of 5.28. Example 10 Example 9 except that 0.02 mmol of compound () was used
In the same manner as above, 10.24 g of polybutadiene was obtained. This polybutadiene has a cis-1,4 structure content.
89.8%, trans-1,4 structure content 1.0%,
1,2 structure content is 9.2% and intrinsic viscosity [η]
was 5.06. Example 11 10.56 g of polybutadiene was obtained in the same manner as in Example 6, except that 0.44 mmol of ethylene glycol was used instead of water. This polybutadiene is cis-
The 1,4 structure content was 91.5%, the trans-1,4 structure content was 0.9%, the 1,2 structure content was 7.9%, and the intrinsic viscosity [η] was 5.21.

Claims (1)

[Claims] 1. A method for producing polybutadiene by polymerizing 1,3-butadiene in the presence of a catalyst, in which (a) a cobalt compound, (b) a halogen-containing organoaluminum compound, (c) water or a polyhydric alcohol, and (d) A method for producing polybutadiene, which comprises polymerizing 1,3-butadiene using a catalyst obtained from dithiocarbamic acids.