JPH0357128B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention has a 1,2-microstructure content of 7 to 50
%, the content of cis-1,4-microstructure is 50% or more, the content of trans-1,4-microstructure is 5%
The following describes a method for producing polybutadiene having an intrinsic viscosity of 1 or more and a gel content of 0.03% or less, as measured in toluene at 30°C. [Prior art] A copolymer obtained by adding polybutadiene to styrene monomer and performing a radical polymerization reaction has not only the excellent properties of polystyrene but also has improved impact resistance, so it is considered an impact-resistant polystyrene resin. It is widely marketed as The polybutadiene used to produce this impact-resistant polystyrene resin is generally butadiene (1,
cis-1, obtained by polymerizing 3-butadiene)
4 structure content is 30-35%, trans-1,4 structure content is 50-60%, 1,2 structure content is 10-20%
polybutadiene (low cis polybutadiene),
and polymerization of butadiene in the presence of a cobalt or nickel catalyst, with a cis-1,4 structure content of 96 to 98%, a trans-1,4 structure content of 1 to 2%, and a 1,2-structure. Polybutadiene (high cis polybutadiene) with a content of 1 to 2% is known. [Problem to be solved by the invention] The former low cis polybutadiene is trans-1,
4 structure, the rubber properties are not sufficient, and the polystyrene resin obtained using this low-cis polybutadiene and styrene monomer is not fully satisfactory in terms of impact resistance. On the other hand, the latter high-cis polybutadiene has 1,2
Due to its low structural content of 1 to 2%, its reactivity with styrene monomers (graft reactivity) is low, and polystyrene resins obtained using high-cis polybutadiene and styrene monomers are also fully satisfactory in terms of impact resistance. It has the disadvantage that it is not possible. In other words, the polybutadiene used as a raw material for polystyrene resin with high impact resistance is 1,
It is necessary that both the 2 structure content and the cis-1,4 structure content are high. In addition to the above-mentioned 1,2 structure content and cis-1,4 structure content, it is also important that the polybutadiene used as a raw material for the impact-resistant polystyrene resin has a high molecular weight. 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 difficult to develop. Furthermore, it is important that the gel content be low, since the gel contained in polybutadiene has undesirable effects such as lowering the impact resistance of high-impact polystyrene and causing poor appearance of molded products. Therefore, an object of the present invention is to provide a method for producing polybutadiene that has both a high 1,2 structure content and a high cis-1,4 structure content, and has less gel. [Means for Solving the Problems] That is, the present invention provides a halogen-containing organoaluminum compound, (a) a cobalt dithiocarbamate compound, or (b) a reaction product of carbon disulfide, a secondary amine, and a cobalt compound, and water free. In the presence of a catalytic system consisting of a group scavenger,
1,3-butadiene is polymerized to obtain (a) a content of 1,2-microstructure of 7 to 50%, (b) a content of cis-1,4-microstructure of at least 50%, (C) trans-1, 1,2- and cis, characterized in that they produce polybutadiene with a content of 4-microstructure of at most 5%, and (d) an intrinsic viscosity of at least 1, measured at 30° C. in toluene, and (e) a gel content of not more than 0.03%. -1,4-
High microstructure content and trans-1,4-
The present invention relates to a method for producing highly polymerized polybutadiene with a low microstructure content. That is, the present invention achieves both a high 1,2 structure content and a high cis-1,4 structure content by polymerizing butadiene using a specific catalyst system, and has properties as a rubber. This made it possible to produce polybutadiene with excellent properties. The styrenic resin obtained from the polybutadiene and styrene monomer obtained by the present invention has excellent impact resistance such as excellent Izot impact strength and markedly improved Dupont impact strength, making it particularly excellent as an impact resistant material. becomes. Furthermore, it is suitable for manufacturing commercially available rubber products. The halogen-containing organoaluminum compound used in the present invention has the general formula _{AlR o} It can be represented by the number 2). Examples of R include methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, cyclohexyl and phenyl. Specific examples of the halogen-containing organoaluminum compound used in the present invention include dialkylaluminum halides such as diethylaluminum monochloride, diethylaluminum monobromide, and diisobutylaluminum monochloride, and alkylaluminum sesquihalides such as ethylaluminum sesquichloride. can be mentioned. The catalyst (a) component cobalt dithiocarbamate compound used in the present invention has the general formula (): (However, R ¹ and R ² may be the same or different from each other, and each represents a chain or cyclic alkyl group having 1 to 20 carbon atoms, and R ¹ and R ² may be mutually connected. may form a ring containing a nitrogen atom). In the general formula (), R ¹ and R ² are each generally selected from an alkyl group having 1 to 12 carbon atoms, preferably a lower alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, Mention may be made of propyl, butyl, pentyl, hexyl and cyclohexyl. Also, R ¹ and R ²
Examples of a group in which these groups are interconnected to form a ring containing a nitrogen atom include a piperidyl group and a pipecolyl group. Specific examples of the cobalt dithiocarbamate compound used in the present invention include the following compounds. Cobalt dimethyldithiocarbamate, Cobalt diethyldithiocarbamate, Cobalt dipropyldithiocarbamate, Cobalt dibutyldithioalbamate, Cobalt dicyclohexyldithiocarbamate, Cobalt pentamethylenecarbamate, Cobalt pipecolyldithiocarbamate (cobalt methylpentamethylene dithiocarbamate). Any compound can be used as the cobalt compound used to prepare the catalyst component (b) of the present invention, but preferably organic acid salts such as cobalt acetate, cobalt octenoate, cobalt naphthenate, and cobalt stearate, cobalt trisacetylacetonate, cobalt bisacetylacetonate, and inorganic salts such as cobalt chloride, cobalt bromide, cobalt iodide, cobalt nitrate, and cobalt carbonate. Any compound can be used as the secondary amine, but dimethylamine, diethylamine, dipropylamine, dibutylamine, dihexylamine, dioctylamine, piperidine, pipecoline and the like are preferred. Solvents used in preparing the catalyst (b) component include aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as hexane and heptane, and methylene chloride, chloroform, carbon tetrachloride,
Halogenated hydrocarbons such as chlorobenzene are preferred, and may partially contain diene monomers, olefin monomers, and aromatic vinyl monomers. The concentration of the cobalt compound used in preparing the catalyst (b) component is 0.2 mol/l or less, preferably 0.1
mol/l or less, and the molar ratio of cobalt compound to secondary amine is from 1:1 to 1:6, preferably 1:
1 to 1:4, and the molar ratio of secondary amine to carbon disulfide is 1:0.5 or more, preferably 1:0.5 to 1:5.
is within the range of When preparing the catalyst (b) component, a cobalt compound,
There is no particular restriction on the order in which the three components, carbon disulfide and secondary amine, are added. The mixing reaction temperature is also not particularly limited, but preferably 10 to 40°C, and the mixing reaction time is also not particularly limited, but if the cobalt compound is insoluble in the solvent used, time is required for the cobalt compound to react and dissolve. becomes. The catalyst (b) component is prepared by adding a cobalt compound, carbon disulfide, and a secondary amine in a predetermined amount of a solvent according to the respective molar ratios, stirring for a certain period of time, and then diluting to an appropriate concentration. , used in polymerization. Preferred examples of the free radical scavenger used in the present invention include 1,4-benzoquinone, chloranil, 1,1-diphenyl-2-picrylhydrazyl, and galarbinoxyl. When butadiene is polymerized using the catalyst system of the present invention, the catalyst component is preferably used in an amount of 0.001 to 0.5 mmol based on the cobalt compound per mole of butadiene. Hereinafter, the amount of the catalyst (a) component is based on the cobalt compound. The molar ratio of catalyst component to halogen-containing organoaluminum compound is preferably in the range from 1:5 to 1:1000, especially from 1:10 to 1:350. In the catalyst system of the present invention, the presence of water is an essential component for the polymerization reaction to proceed smoothly, and when used, the molar ratio (H ₂ O / Al) of water and halogen-containing organoaluminum compound is 0.01:1 to 0.7. :1, particularly preferably in the range of 0.1:1 to 0.6:1. The molar ratio of the free radical scavenger to the catalyst component is from 0.2:1 to 20:1, preferably from 0.5:1.
The ratio is 10:1, and the catalyst component can reduce the amount of gel and increase the 1,2 structure content. If it is less than 0.2:1, the effect of the catalyst (d) component will be small, and if it is more than 20:1, the polymerization activity will be too low, which is not preferable. Polymerization solvents include aromatic hydrocarbons such as benzene, toluene, and xylene, butane, butene, and n-
Aliphatic hydrocarbons such as hexane, n-heptane, cyclohexane, halogenated hydrocarbons such as methylene chloride, carbon tetrachloride, etc. can be used, but aromatic hydrocarbon solvents are preferred. Further, known molecular weight regulators such as cyclooctadiene, 1,2-butadiene, and allene can also be used. The polymerization reaction temperature of butadiene is 5 to 80℃, especially 20℃.
~70°C is preferred. In preparing the catalyst system used in the present invention, it is desirable that the catalyst component and the halogen-containing organoaluminum compound be brought into contact in the presence of butadiene. That is, when preparing the catalyst system, the catalyst component and the halogen-containing organoaluminum compound are brought into contact in a system in which butadiene is not present;
Polybutadiene obtained by a polymerization reaction using a catalyst system prepared by mixing this and water is 1,2
The structural content tends to decrease. In particular, in the case of a catalyst system prepared through an operation in which the catalyst component and the halogen-containing organoaluminum compound are brought into contact with each other for a long period of time in the absence of butadiene at high temperature or even at low temperature, the catalyst system is aged. The trend becomes noticeable. Therefore, when preparing the catalyst system used in the present invention, it is desirable to carry out the contact operation between the catalyst component and the halogen-containing organoaluminum compound in the presence of butadiene. In addition, when the contact operation between the catalyst component and the halogen-containing organoaluminum compound is carried out in the absence of butadiene, the conditions are such that the ripening between these two components does not proceed much, for example, at a temperature of 50°C or lower,
In addition, it is desirable to set a limit such that the contact time in the absence of butadiene is within 5 minutes. The polymerization reaction of the present invention can be carried out according to conventionally known butadiene (1,3-butadiene) polymerization reaction operations. However, when carrying out the present invention, for the above-mentioned reasons, a method is used in which water is dissolved in a mixture of butadiene and a solvent, a halogen-containing organoaluminum compound is added, and then a catalyst component is added to initiate polymerization. Although there is no particular restriction on the order in which the catalyst components are added, it is most preferable to add them after the catalyst components have been added to initiate polymerization. The 1,2 structure content of the obtained polybutadiene increases as the molar ratio (Al/Co) of the halogen-containing organoaluminum compound and the catalyst component decreases.
In the catalyst (b) component, the cobalt compound in the catalyst (b) component,
The 1,2 structure content can also be changed by changing the composition ratio of carbon disulfide and secondary amine. For example, by setting the molar ratio of carbon disulfide and secondary amine to 1:1 and increasing this amount relative to the cobalt compound, the 1,2 structure content can be increased. Also, the molar ratio of water and halogen-containing organoaluminum compound (H ₂ O/Al)
The 1,2 structure content can also be increased by increasing . By further adding catalyst components, 1,2
Polybutadiene with a high structural content and a low gel content can be produced. After the polymerization reaction is completed, if desired, an antiaging agent may be added to the reaction solution, and then polybutadiene can be extracted using a known method, such as a method of treating the reaction solution with alcohol, hot water, or water. can. By the above method according to the present invention 1,2
Structural content is 5 to 45%, cis-1,4 structure content is 50% or more, trans-1,4 structure content is 5%
Below, and intrinsic viscosity [η] (toluene, 30℃)
polybutadiene having a gel content of 1 or more and a gel content of 0.03% or less can be easily produced. The polybutadiene obtained by the present invention is, for example, 2 to 25 parts by weight (preferably 2 to 25 parts by weight) of polybutadiene.
~20 parts by weight) and 75 to 98 parts by weight (preferably 80 to 98 parts by weight) of styrene is subjected to radical polymerization by a lump method or a lump suspension method, preferably a lump suspension method. As a result, a polystyrene resin with excellent impact resistance can be obtained. It is also suitable for manufacturing commercially available rubber products. In addition, the 1,2 structure content described in this specification,
Cis-1,4 structure content and trans-1,4
The structural content (also collectively referred to as microstructure) is a value calculated from the IR spectrum and NMR spectrum, and the intrinsic viscosity [η] is a value measured in toluene at a temperature of 30°C. Gel content is approximately 4g of polymer and 200ml of toluene.
After dissolving it in a 400-mesh wire mesh, the wire mesh was thoroughly washed with toluene, and the weight increase was calculated from the weight increase after vacuum drying the wire mesh at 80° C. for 5 hours. [Example] Examples 1 to 4 After replacing the air in an autoclave with a capacity of 1.5 with dry nitrogen gas, 717 ml of dehydrated benzene and 1,
176 g of 3-butadiene was added, 1.33 mmol of water was added, and the mixture was stirred at 30°C for 30 minutes to dissolve the water. Next, 4.0 mmol of diethylaluminium monochloride and 49 mmol of 1,5-cyclooctadiene were added, the temperature was raised to 60°C, 0.07 mmol of cobalt diethyldithiocarbamate was added, and then, after 1 minute, 1,4-benzoquinone A predetermined amount (listed in Table 1) was added, and polymerization was carried out by stirring at 60° C. for a prescribed time (listed in Table 1). After the polymerization reaction, 2,6-di-t-butyl-p
- Add 15 ml of methanol containing a small amount of cresol to the reaction solution to stop the polymerization reaction, and add 15 ml of methanol containing a small amount of cresol to the reaction solution.
of methanol to precipitate the produced polymer, and this polymer was dried under reduced pressure at room temperature for 24 hours. The microstructure, intrinsic viscosity, and gel content of the obtained polymer were measured. The results are shown in Table 1.

[Table] Examples 5 to 8 Polymerization of butadiene in the same manner as in Example 3 except that the catalyst components shown in Table 2 were used instead of 1,4-benzoquinone, and the polymerization time was changed as shown in Table 2. The reaction was carried out and the produced polymer was taken out. The results are shown in Table 2.

[Table] However
(a) 1,1〓diphenyl〓2〓picrylhydrazyl
(b) Galvinoxyl Examples 9 and 10 A 1,3-butadiene solution having the following weight composition was polymerized. 1,3-butadiene 24.0% Cis-2-butene 19.5〃 Trans-2-butene 6.3〃 Isobutene 0.5〃 1-Butene 0.2〃 Ethane 0.1〃 Benzene 49.4〃 After replacing the air in the autoclave with a capacity of 1.5 with dry nitrogen gas , add 1000 ml of the above 1,3-butadiene solution, add 1.5 mmol of water, and add 1.5 mmol of water.
The mixture was stirred at ℃ for 30 minutes to dissolve the water. Next, 3.3 mmol of diethylaluminum monochloride and 1,
After adding 20 mmol of 5-cyclooctadiene, the temperature was raised to 60°C, 0.07 mmol of cobalt diethyldithiocarbamate was added, and then, after 1 minute, 0.074 mmol of 1,4-benzoquinone was added.
Polymerization was carried out by stirring at 60° C. for a predetermined period of time (listed in Table 3). The treatment after the completion of the polymerization reaction was carried out in the same manner as in Example 1.

[Table] Example 11 Amount of diethylaluminum monochloride
The polymerization reaction of butadiene was carried out in accordance with Example 10 except that the amount of 1,4-benzoquinone was changed to 4.0 mmol and 0.35 mmol, and the resulting polymer was recovered. The yield of polybutadiene obtained is
78g, [η] is 2.20, cis-1,4 structure content 82.1%, trans-1,4 structure content 1.8%,
The 1,2 structure content was 16.1% and the gel content was 0.012%. Example 12 A butadiene polymerization reaction was carried out in the same manner as in Example 4, except that 20 ml of the catalyst (b) component solution shown below was used instead of cobalt diethyldithiocarbamate.
The produced polymer was taken out. Catalyst (b) component preparation method Add 2.8 ml of a benzene solution of 0.7 mol/carbon disulfide to 20 ml of a benzene solution of 0.035 mol/cobalt octenoate, then add 2.8 ml of a benzene solution of 0.7 mol/diethylamine under stirring.
After stirring for one day at room temperature (25°C), 25.6 ml of this solution
was diluted with 174.4 ml of benzene to prepare a 0.0035 mol/catalyst (b) component solution. The yield of the obtained polybutadiene was 75g,
[η] is 2.22, cis-1,4 structure content 78.6%,
The trans-1,4 structure content was 0.8%, the 1,2 structure content was 20.6%, and the gel content was 0.008%. Example 13 Impact-resistant polystyrene resins were produced using the polybutadiene produced in Examples 11 and 12 by the method shown below, and impact resistance tests were conducted on each of them. In addition, commercially available high cis polybutadiene rubber (high cis polybutadiene rubber)
BR: Cis-1,4 structure content 95.1%, trans-1,4 structure content 2.5%, 1,2 structure content 2.4
%, [η] = 2.0), and commercially available low-cis polybutadiene rubber (low-cis BR: cis-1,4 structure content
31.7%, trans-1,4 structure content 54.9%,
From the 1,2 structure content of 13.4%, [η] = 1.9),
Impact resistant polystyrene resins were produced in a similar manner and impact resistance tests were conducted on each. Manufacturing method of impact-resistant polystyrene resin After replacing the air in the separable flask in step 1 with nitrogen gas, 570 g of styrene and polybutadiene
30g (5% by weight) was added and dissolved, and then n-
After adding 0.3 g of dodecyl mercaptan and 11.4 g of n-butyl stearate, polymerization was carried out at 120°C with stirring until the styrene polymerization rate reached 30%.
Next, 0.5% by weight polyvinyl alcohol aqueous solution
Add the reaction solution to 600 ml, pour this into an autoclave, add 0.93 g of benzoyl peroxide and 0.93 g of dicumyl peroxide, and incubate at 100°C for 2 hours, then at 125°C for 3 hours, and then at 140°C for 2 hours.
Polymerization was carried out under stirring for hours. Bead-shaped polymers are collected from this reaction mixture by filtration, washed with water, dried, and pelletized using an extruder to form polystyrene resin.
Got 500g. The measurement results are shown in Table 4.

〔Effect of the invention〕

As mentioned above, according to the present invention, it is possible to produce polybutadiene with a high yield that has both a 1,2 structure content and a high cis-1,4 structure content and also has excellent properties as a rubber. can.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing a method for producing polybutadiene according to claim 1.

Claims (1)

[Scope of Claims] 1 Presence of a catalyst system consisting of a halogen-containing organoaluminum compound (a) a cobalt dithiocarbamate compound or (b) a reaction product of carbon disulfide, a secondary amine and a cobalt compound, and water a free radical scavenger Below,
1,3-butadiene is polymerized to obtain (a) a content of 1,2-microstructure of 7 to 50%, (b) a content of cis-1,4-microstructure of at least 50%, (C) trans-1, 1,2- and cis, characterized in that they produce polybutadiene with a content of 4-microstructure of at most 5%, and (d) an intrinsic viscosity of at least 1, measured at 30° C. in toluene, and (e) a gel content of not more than 0.03%. -1,4-
A method for producing a highly polymerized polybutadiene having a high microstructure content and a low trans-1,4-microstructure content. 2 The halogen-containing organoaluminum compound has the following general formula () AlR _o X _3-o () where R represents an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group, or a phenyl group, and , n is a number from 1.5 to 2. 3 The above cobalt dithiocarbamate compound (a) has the following general formula () Here, R ¹ and R ² may be the same or different and represent an alkyl group, phenyl group, or cycloalkyl group having 1 to 20 carbon atoms, or R ¹
and R ² may be bonded to each other and together with the nitrogen atom to which they are bonded to form a heterocycle, and n is a number from 2 to 3. The method described in section. 4 The reaction product (b) is carbon disulfide, a secondary amine and A method according to claim 1, wherein the reaction product is a mixture of cobalt compounds. 5. When preparing the above catalyst system, at least a halogen-containing organoaluminum compound and a cobalt dithiocarbamate compound (a) or a reaction product of carbon disulfide, a secondary amine, and a cobalt compound (b) are combined into 1,3 - The method according to claim 1, wherein the contacting is carried out in the presence of butadiene.