JPH0364527B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing a novel block copolymer comprising a conjugated diene monomer and a vinyl aromatic monomer. Specifically, the present invention relates to a method for producing a block copolymer containing one or more vinyl aromatic hydrocarbon polymer blocks and one or more crystalline trans-conjugated diene polymer blocks in the polymer chain. [Prior art] Production technology using _IA metal compounds such as organolithium as polymerization catalysts utilizes living anionic polymerization properties to sequentially polymerize vinyl aromatic monomers and conjugated diene monomers, and if necessary, A block copolymer of a vinyl aromatic monomer and a conjugated diene monomer can be obtained by performing a coupling reaction. The obtained block copolymers are used in footwear, plastic modifiers, and adhesives.
The trans bond content of the conjugated diene moiety is low, and a block copolymer having a crystalline trans conjugated diene polymer block has not been obtained. On the other hand, it is known that conjugated diene polymers with a high content of trans-1,4-bonds can be produced by the following three techniques. (1) Production technology that uses a so-called Ziegler catalyst that has a transition metal as its main component (2) Production technology that uses an anionic polymerization catalyst system that has an alkaline earth metal compound as its main component (3) A production technology that uses a rare earth metal compound as its main component Production technology using a catalyst system It is known that the first technology, which uses transition metals such as nickel, cobalt, titanium, and vanadium as main components, involves highly stereoregular polymerization of conjugated diene monomers. However, due to the low living nature of polymerization activity and low copolymerizability with vinyl aromatic monomers, it is difficult to produce block copolymers of conjugated diene monomers and vinyl aromatic monomers using these production techniques. It was difficult. As for the technology belonging to the second technology, there are examples in which organometallic compounds of metal _A are used as polymerization catalysts, but in general, organometallic compounds of metal _A other than beryllium and magnesium are difficult to synthesize and have significant polymerization activity. It was very low. Although organometallic compounds of beryllium and magnesium are relatively easy to synthesize, they have no polymerization activity toward conjugated dienes except under special reaction conditions, and no examples have been put to practical use. On the other hand, as a method of combining organic acid salts of metal _A such as barium and strontium with other organometallic compounds, barium di-
Tert-butoxide and organic lithium
3728), barium di-tert-butoxide and organomagnesium (JP-A-52-48910), or
A method is known in which a conjugated diene monomer is polymerized using an organic compound of barium or strontium, an organic compound of organolithium, and metal _B or _A (Japanese Patent Application Laid-Open No. 30543/1983). In the method using a composite catalyst containing these _A metal compounds, copolymerization of a conjugated diene monomer and a vinyl aromatic monomer is also possible, but if the trans bond content of the conjugated diene moiety exceeds 75% When attempting to obtain a polymer exhibiting crystallinity with high stereoregularity, it is generally necessary to lower the polymerization temperature, resulting in a low polymerization activity. In particular, when attempting to block copolymerize a conjugated diene monomer and a vinyl aromatic monomer, it is necessary to complete the reaction in each block of the polymerization reaction, and high living properties are required for the active terminal, so this application It has been difficult to obtain a crystalline block copolymer of a conjugated diene monomer and a vinyl aromatic monomer that has the excellent properties that are the object of the invention. Furthermore, as a technique belonging to the third technique, a technique using neodymium versatate and organic magnesium as a polymerization catalyst is known (Japanese Patent Application Laid-Open No. 1508-1982). According to this technology, a crystalline butadiene polymer with a high trans bond content can be obtained, but the polymerization activity, especially the copolymerization activity with vinyl aromatic monomers such as styrene, is extremely low, and the conjugated diene polymer It has been difficult to obtain a block copolymer of a vinyl aromatic monomer and a vinyl aromatic monomer. (Problems to be Solved by the Present Invention) As described above, in the technology using conventional polymerization catalysts, there are problems with the catalyst properties, so conjugated diene monomers with a high trans bond content and vinyl aromatic It has been extremely difficult to produce block copolymers with monomers. (Means and effects for solving the problem) As a result of our intensive study on the method for producing a copolymer containing a crystalline trans-conjugated diene polymer block and a vinyl aromatic hydrocarbon polymer block, we have found that:
We have arrived at the present invention. That is, the present invention provides (1) the following catalyst components (a), (b) and (c), or
A monomer selected from vinyl aromatic monomers and conjugated diene monomers, or a mixture thereof, obtained from (a), (b), (c) and (d) and characterized in that a composite catalyst is used. A method for producing a copolymer consisting of an aromatic vinyl monomer having two or more block chains having different compositions and a conjugated diene monomer, which is obtained by sequentially polymerizing the following. (a) Organic compounds of barium or strontium (b) Organic compounds of lithium (c) Organomagnesium (d) Organoaluminium or organozinc (2) Trans conjugates in the polymer chain that exhibit crystallinity when unstretched or when stretched A method for producing a copolymer according to item 1 above, which has one or more diene polymer blocks and one or more aromatic vinyl polymer blocks having a glass transition temperature of room temperature or higher. Components (a), (b) and (c), or (a), (b), (c) and (d)
Using a composite catalyst obtained from This is a method for producing a copolymer as described in items 1 to 3 above, which comprises an aromatic vinyl monomer having the above block chain and a conjugated diene monomer. The block copolymer obtained by the present invention has various advantages depending on the composition ratio of the conjugated diene and vinyl aromatic hydrocarbon and the melting point of the conjugated diene moiety, which mainly depends on the trans bond content. It shows the characteristics that That is, the polymer obtained by the production method of the present invention (1) exhibits properties as a so-called thermoplastic elastomer when the content of vinyl aromatic hydrocarbons is relatively low and the melting point of the conjugated diene block is below room temperature. In this case, the conjugated diene block exhibits stretch crystallinity, and the polymer has significantly high strength. Furthermore, the glass transition temperature of the rubber portion is lowered, and the impact resilience is also excellent. (2) When the content of vinyl aromatic hydrocarbons is relatively small and the melting point of the conjugated diene block is above room temperature, the resin-like polymer has even higher hardness and strength and excellent rebound properties. In addition, since this type of polymer is extremely prone to orientation and crystallization, for example, if the glass transition temperature of the vinyl aromatic hydrocarbon block is higher than the melting point of the conjugated diene block, When a sample molded at high temperature is deformed at a temperature below the glass transition temperature of the vinyl aromatic hydrocarbon block and above the melting point of the conjugated diene block, this shape is frozen and maintained when cooled, and when it is heated again to a temperature above the melting point of the conjugated diene block. It exhibits excellent properties as a shape memory resin, such as quickly recovering the shape of molded samples. (3) Furthermore, when the content of vinyl aromatic hydrocarbon is high, the thermoplastic resin has high hardness, high strength, and excellent impact resistance. That is, the object of the present invention is to provide a method for efficiently producing a copolymer containing a vinyl aromatic hydrocarbon polymer block and a crystalline trans-conjugated diene polymer block, which have the above-mentioned various excellent properties. . The organic compound of barium or strontium, which is the catalyst component (a) of the composite catalyst used in the production method of the present invention, has the following general formulas () to (
) to be selected from. R ¹ −X−) ₂ Me ……() [R ³ -O(-CH ₂ -CH ₂ -O) _a ] ₂ ---Me
...() (R ⁸ OSO ₃ −) ₂ Me ... () (R ⁹ SO ₃ -) ₂ Me ... () (wherein, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ represents an aliphatic hydrocarbon group or an aromatic hydrocarbon group, R ⁸ and R ⁹ are respectively an aliphatic hydrocarbon group,
represents an aromatic hydrocarbon group, a and b represent an integer of 1 or more and 6 or less, c represents an integer of 2 or more and 8 or less, X represents an oxygen or sulfur atom, and Me represents barium or strontium metal. represent Examples of general formula () are ethyl alcohol,
n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, iso-butyl alcohol, 2-butyl alcohol, tert-butyl alcohol, n-amyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, Cyclohexyl alcohol, allyl alcohol, cyclopentyl alcohol, benzyl alcohol, phenol, 1-naphthol, 2,6-di-tert-butylphenol, 2,
4,6-tri-tert-butylphenol, nonylphenol, 4-phenylphenol, ethanethiol, 1-butanethiol, thiophenol,
Examples include barium or strontium salts of alcohols such as cyclohexanethiol and 2-naphthalenethiol, phenols, thioalcohols, and thiophenols. Examples of general formula () are isovaleric acid, capric acid, octanoic acid, lauric acid, myristic acid,
Consists of a mixture of isomers of palmitic acid, stearic acid, oleic acid, linoleic acid, cyclopentanecarboxylic acid, naphthenic acid, ethylhexanoic acid, pivalic acid, versatic acid, C10 monocarboxylic acids (sold by Siel Chemical) synthetic acid),
Examples include barium or strontium salts of carboxylic acids or sulfur congeners such as phenylacetic acid, benzoic acid, 2-naphthoic acid, hexanethiolic acid, 2,2-dimethylbutanethionic acid, decanethionic acid, tetradecanethionic acid, and thiobenzoic acid. . Examples of general formula () include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether,
Examples include barium or strontium salts such as diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, and diethylene glycol monophenyl ether. Examples of general formula () include dimethylaminoethanol, diethylaminoethanol, di-n-
Examples include barium or strontium salts such as propylaminoethanol. Examples of general formula () are dimethylamine, diethylamine, di-n-propylamine, di-
iso-propylamine, di-n-butylamine,
Examples include barium or strontium salts of secondary amines such as di-n-hexylamine. Examples of the general formula () include barium or strontium salts of cyclic imines such as ethyleneimine, triethyleneimine, pyrrolidine, piperidine, and hexamethyleneimine. Examples of general formula () are butanesulfonic acid,
Hexane sulfonic acid, decane sulfonic acid, tridecane sulfonic acid, dodecylbenzenesulfonic acid,
Examples include barium or strontium salts of tetradecylbenzenesulfonic acid, octadecylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, di-iso-propylnaphthalenesulfonic acid, n-hexylnaphthalenesulfonic acid, dibutylphenylsulfonic acid, and the like. Examples of the general formula () include barium or strontium salts such as sulfuric ester of lauryl alcohol, sulfuric ester of oleyl alcohol, and sulfuric ester of stearyl alcohol. Furthermore, the organic compound of lithium, which is the catalyst component (b) of the composite catalyst used in the production method of the present invention, is selected from organic lithium or organic acid salts of lithium represented by the following general formulas () to (). It will be done. R ¹⁰ V (-Li) _d ... () R ¹¹ (-X-Li) _e ... () R ¹² -O (-CH ₂ -CH ₂ -O-) _f Li ... (XI) (In the formula, R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ represent an aliphatic hydrocarbon group or an aromatic hydrocarbon group, d, e, f and g are 1 or more, represents an integer of 6 or less, h represents an integer of 2 or more and 8 or less, and X represents an oxygen or sulfur atom. Examples of general formula () include methyllithium, ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, isoamyllithium, sec-amyllithium-n-hexyllithium, n-octyllithium, allyllithium, benzyllithium, phenyllithium, 1,
1-diphenyl-n-hexyllithium, tetramethylene dilithium, pentamethylene dilithium, 1,2-diliothio-1,1,2,2-tetraphenylethane, 1,3-bis(1-lithio-
Examples include 1,3-dimethylpentyl)benzene. Preferably n-butyllithium, sec-
Butyllithium, tert-butyllithium, 1,3
Examples include organic lithium compounds such as -bis(1-lithio-1,3-dimethylpentyl)benzene. Examples of general formula () are ethyl alcohol,
n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, iso-butyl alcohol, 2-butyl alcohol, tert-butyl alcohol, n-amyl alcohol, n-hexyl alcohol, n-heptyl alcohol, n-octyl alcohol, Cyclohexyl alcohol, allyl alcohol, cyclopentyl alcohol, benzyl alcohol, phenol, 1-naphthol, 2,6-di-tert-butylphenol, 2,
4,6-tri-tert-butylphenol, nonylphenol, 4-phenylphenol, ethanethiol, 1-butanethiol, thiophenol,
Examples include alcohols such as cyclohexanethiol and 2-naphthalenethiol, phenols, thioalcohols, and lithium salts of thiophenols. Examples of general formula (XI) include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monopropyl ether, diethylene glycol monoether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether and lithium salts such as diethylene glycol monophenyl ether. Examples of general formula (XII) include dimethylaminoethanol, diethylaminoethanol, di-n-
Examples include lithium salts such as propylaminoethanol. Examples of general formula () are dimethylamine,
diethylamine, di-n-propylamine, di-
iso-propylamine, di-n-butylamine,
Examples include lithium salts of secondary amines such as di-n-hexylamine. Examples of general formula () are ethyleneimine,
triethyleneimine, pyrrolidine, piperidine,
Examples include lithium salts of cyclic imines such as hexamethyleneimine. Particularly preferred organic compounds of lithium are alkyllithiums having 2 to 10 carbon atoms, such as n-butyllithium, sec-butyllithium, and sio-amyllithium. The organic magnesium (c) used is represented by the following general formula (). (Here, R ¹⁷ and R ¹⁸ represent an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be the same group or different groups.) In addition, organomagnesium includes In order to improve its solubility in hydrocarbon solvents, it may contain a small amount of organic aluminum or organic zinc. Such examples include diethylmagnesium,
Di-n-propylmagnesium, di-isopropylmagnesium, di-n-butylmagnesium,
n-butyl-sec-butylmagnesium, di-sec
-butylmagnesium, di-tert-butylmagnesium, di-n-hexylmagnesium, di-n
-Propylmagnesium, diphenylmagnesium, MAGALA-6E, 7,5E (Texas Alkyl Corporation), etc. are preferred, but more preferred are di-isopropylmagnesium, di-n-butylmagnesium, di-sec-butylmagnesium, Examples include MAGALA-6E, -7, 5E. Furthermore, in the production method of the present invention, an organic metal selected from organic aluminum or organic zinc can be used as the catalyst component (d) if necessary. The organic aluminum used is represented by the following general formula (). (Here, R ¹⁹ , R ²⁰ , and R ²¹ are selected from hydrogen, an aliphatic hydrocarbon group, or an aromatic hydrocarbon group, and may be the same group or different groups. However, all is not hydrogen.) Such examples include triethylaluminum, tri-iso-butylaluminum, tri-n
-propyl aluminum, tri-ise-propyl aluminum, tri-n-hexyl aluminum, diethyl aluminum monohydride, and the like. The organic zinc used is represented by the following general formula (). R ²² −Zn−R ²³ ...() (Here, R ²² and R ²³ are selected from hydrogen, an aliphatic hydrocarbon group, or an aromatic hydrocarbon group, and may be the same group or different groups. (Also, it is not all hydrogen.) Such examples include diethylzinc, di-n-
Propyl zinc, di-iso-amyl zinc, di-iso-
Examples include butylzinc. The amount of organomagnesium used as the catalyst component (c) depends on the molecular weight of the target polymer, but
Generally, the amount is in the range from 0.1 to 50 mmol, preferably from 0.5 to 5 mmol, per 100 g of total monomer. If the amount of organomagnesium used is less than 0.1 mmol, the polymerization activity of the catalyst will generally be markedly reduced, and the molecular weight of the resulting polymer will be markedly increased, making processing difficult, which is undesirable. In addition, when the content of organomagnesium exceeds 50 mmol,
The molecular weight of the resulting polymer becomes significantly low, which is generally not preferred. Further, the amount of the lithium organic compound used as the catalyst component (b) is in the range of Li/Mg = 0.1 to 10, expressed as a molar ratio of lithium to magnesium,
Preferably it is in the range of 0.5-2. Li/Mg=0.1
If the amount of lithium is less than that, the polymerization activity, especially the polymerization initiation rate, will be significantly lowered, which is not preferable. Also Li/
If the amount of lithium exceeds Mg=10, the proportion of 1,4-trans bonds in the conjugated diene will significantly decrease during the polymerization stage of the conjugated diene monomer, and the resulting polymer will become amorphous. cannot achieve its purpose. The amount of the catalyst component (a) used, that is, the organic compound of barium or strontium, is expressed in molar ratio with magnesium, Me ¹ /Mg=
It ranges from 0.005 to 10 (Me ¹ is barium or strontium metal), preferably from 0.01 to 1. If ME ¹ /Mg is less than 0.005, the proportion of 1,4-trans bonds in the conjugated diene will be significantly reduced in the step of polymerizing the conjugated diene monomer, and the resulting polymer will become non-crystalline. cannot be achieved. In addition, if the amount exceeds Me ¹ /Mg = 10, the polymerization activity of the composite catalyst will be markedly reduced, which is undesirable. In addition to c), organoaluminium or organozinc may be used as the catalyst component (d) if necessary. The amount of catalyst component (d) used is Me 2 /Mg = 50 or less (Me ² is aluminum or zinc metal) expressed in molar ratio with magnesium, preferably Me ² /Mg = 50 or less (Me ² is aluminum or zinc metal).
Mg=5 or less. The proportion of 1,4-trans bonds in the conjugated diene moiety can be increased by adding catalyst component (d), but if the amount exceeds Me ² /Mg = 50, the polymerization activity of the composite catalyst will decrease significantly. I don't like it. In the polymer obtained by the production method of the present invention, a vinyl aromatic monomer having a glass transition temperature equal to or higher than room temperature must be homopolymerized or other vinyl aromatic monomer or conjugated diene monomer must be present in the polymer chain. A polymerization block mainly composed of a vinyl aromatic monomer copolymerized with a conjugated diene monomer and a conjugated diene monomer that can exhibit crystallinity based on a high 1,4-trans bond content is used as a homopolymer or other conjugated diene monomer. Each of them contains one or more polymerization blocks whose main component is a conjugated diene monomer copolymerized with a monomer or a vinyl aromatic monomer. These polymers can be obtained by sequentially charging each monomer alone or a mixture into a reactor and polymerizing them using the composite catalyst shown in the claims of the present invention. Examples of vinyl aromatic monomers that can be used in the present invention include styrene, α-methylstyrene, p-methylstyrene, m-methylstyrene, o-methylstyrene, p-tert-butylstyrene, dimethylstyrene, vinylnaphthalene. etc. A particularly preferred vinyl aromatic monomer is styrene. In addition, conjugated diene monomers that can be copolymerized include:
Examples include 1,3-butadiene, isoprene, piperylene, and the like. A particularly preferred conjugated diene monomer is 1,3-butadiene. Polymerization can be carried out without a solvent or in the presence of a solvent. In the latter case, usable solvents include aliphatic or alicyclic hydrocarbons such as n-pentane, n-hexane, n-heptane, and cyclohexane, and aromatic hydrocarbons such as benzene and toluene. Further, the solvent may partially contain a polar organic compound that does not contain active hydrogen, such as tertiary amines and ethers, for the purpose of promoting the polymerization reaction, improving the solubility of the catalyst, and the like. Polymerization temperature is -30℃~150℃, preferably 50~120℃
Conducted at °C. Although the polymerization reaction format is not particularly limited, a batch method is generally preferred. After the polymerization reaction is completed, depending on the desired polymer, further coupling with a coupling agent is possible, and thereby the physical properties of the resulting polymer can be improved. As the coupling agent, coupling agents used in terminal coupling reactions in anionic polymerization of general dienes can be used. Examples of coupling agents that can be used include multiepoxides, multiisocyanates, multiimines, althialdehydes, multiketones, multianhydrides, multiesters, monoesters, multihalides, carbon monoxide, and carbon dioxide. Particularly preferred coupling agents include multihalogenated silicon compounds such as tetrachlorosilane, trichloromonomethylsilane, trichloromonoethylsilane, and dichlorodiethylsilane, and multihalogenated tin compounds such as tetrachlortin, trichlormonomethyltin, and trichlormonoethyltin. , diphenyl carbonate,
It is an ester compound such as diethyl adipate. Regarding the amount of coupling agent used, it is considered that the amount equivalent to the organic metal used is the optimum amount for maximum branching. However, any range of coupling agent amounts can be used depending on the degree of coupling desired. Generally, the coupling agent is used in an amount of 0.1 to 1.5 equivalents per organomagnesium. The coupling agent can be added alone or as an inert hydrocarbon solution. Also, the coupling agent can be added all at once, in portions, or continuously. Although the coupling reaction varies depending on its reactivity, it is usually carried out at a temperature close to the polymerization temperature for several minutes to several hours. After the reaction, the polymer can be recovered by adding stabilizers, antioxidants known in the art, and by methods known in the art. Particularly preferred examples of stabilizers and antioxidants include 2,6-di-tert-butyl-4-methylphenol and tri-
Nonylphenylhoffate, phenyl-β-naphthylamine, N,N'-dialkyl-diphenylamine, N-alkyl-diphenylamine and the like can be mentioned. Examples of methods for recovering the polymer include steam stripping and heat drying. In addition, the block copolymer obtained by the production method of the present invention can be prepared by adding fillers, dyes, pigments, curing agents or crosslinking agents, softeners, reinforcing agents, etc. by methods known in the art. etc. can be blended. Still further, the polymer can be extruded, injection molded or press molded to produce the final product. (Effects of the Invention) As detailed above, the present invention has various excellent properties depending on the purpose, such as being useful as a thermoplastic elastomer with high strength and high impact resilience, or hardness, strength, impact resilience, etc. Vinyl aromatic hydrocarbons have various properties that make them useful as excellent resins (in addition, they also have properties useful as shape memory resins) and that they can also be made into products with excellent impact resistance. A copolymer containing a polymer block and a crystalline trans-conjugated diene polymer block is
The novel manufacturing method discovered by the present inventors has achieved the excellent effect of extremely advantageous manufacturing. (Example) The present invention will be specifically described below with reference to Examples, but the scope of the present invention is not limited thereto. Example 1 1.5 kg of a cyclohexane solution containing previously purified and dried styrene at a concentration of 20% by weight was charged into a 10-capacity polymerization vessel equipped with a stainless steel stirrer and the interior was purged with nitrogen gas, and then the catalyst components were added. as barium dinonyl phenoxide 0.0075 mol, dibutylmagnesium ^* 0.0113 mol, sec-butyl lithium 0.0113 mol, triethylaluminum 0.015
mol was added and polymerized for 3 hours at 70°C. At this point, a small amount of the polymerization solution was extracted from the polymerization vessel and analyzed, and the polymerization conversion rate was 100% as determined by gas chromatography analysis, and the number average molecular weight n =
9700, and the molecular weight distribution w/n expressed as a ratio to the weight average molecular weight was 1.14. The GPC measurement conditions were as follows. (a) GPC = Shimadzu LC-6A (b) Developing solution = THF (c) Column temperature = 40°C Next, a cyclohexane solution containing purified and dried 1,3-butadiene at a concentration of 20% by weight in the polymerization solution. 3.5 kg was charged and polymerization was further carried out at 65°C for 3 hours. At this point, a portion of the polymerization solution was extracted and analyzed, and the polymerization conversion rate of butadiene was 94.
It was %. Furthermore, the polymer at this point is the first
As is clear from the GPC measurement results shown in the figure, it was a polymer mixture containing large amounts of styrene-butadiene and diblock polymer. The bound styrene concentration distribution in FIG. 1 was calculated by correcting the copolymerized styrene concentration from the refractive index in GPC, measuring the molecular weight distribution, and measuring the copolymerized styrene concentration from the ultraviolet absorbance. The polymer as a whole had n=34100 and w/n=1.33. The polymerization solution was further charged with an equimolar amount of magnesium using diphenyl carbonate as an end coupling agent, and reacted at 65° C. for 1 hour. As a result of this coupling reaction, the molecular weight of the polymer was found to be w=91900 and w/n=1.42, indicating a significant increase in molecular weight. After the reaction, stop the reaction by adding 10ml of methanol.
Add 0.3 parts by weight of BHT per 100 parts by weight of polymer,
The solvent was evaporated and the polymer was recovered. The final polymer recovery rate was 93%. *Manufactured by Lithium Corpo (n-Butyl, s-Butyl)
(approximately 1:1) Also, from Figure 1, although it contains small amounts of styrene homopolymer and butadiene homopolymer,
It can be seen that most of the polymer is a styrene-butadiene diblock polymer, which is one of the objects of the present invention. The weight content of diblock polymer in the total polymer calculated from these GPC measurement results was 92%. Comparative Example 1 A reaction was carried out under exactly the same conditions as in Example 1, except that 0.0339 mol of n-butyllithium was used alone as the polymerization catalyst. The final polymer yield was 98%. Table 1 shows the polymerization results and the properties of the obtained polymer. From Table 1, styrene produced by the method of the present invention
It turns out that the butadiene block copolymer has unique properties. That is, it exhibits crystallinity based on the trans-polybutadiene moiety, and has the characteristics of high hardening, modulus, tensile strength, and impact resilience. It also showed a significantly large residual elongation at break, but when heated to 70°C, above the melting point, it quickly shrunk and recovered its original shape.

【table】

[Table] *1 Measured by differential thermal analyzer *2 150℃, weight 2.16Kg
*3 Examples 2 to 10 Measured according to JISK-6301 The capped volume after replacing the inside with nitrogen gas is
A 700 ml pressure glass bottle is charged with 120 g of a cyclohexane solution containing 20% by weight styrene that has been purified and dried in advance. Next, 0.50 mmol of barium salt of the organic acid shown in Table 2 as a catalyst component,
0.67 mmol of dibutylmagnesium ^* , 0.67 mmol of sec-butyllithium and 0.89 mmol of triethylaluminum were added and polymerized at 70°C for 3 hours.
At this point, a small amount of the polymerization solution was extracted and analyzed. Then purified and dried 1,3 was added to the polymerization solution.
280 g of a cyclohexane solution containing -butadiene at a concentration of 20% by weight was charged, and polymerization was further carried out at 65°C for 3 hours. After the polymerization, 1 ml of methanol was added to stop the polymerization, 0.3 parts by weight of BHT per 100 parts by weight of the polymer was added, and the solvent was evaporated to recover the polymer. The analysis method was the same as in Example 1. The results are shown in Table-2. The polymerization conversion rates of styrene and butadiene were analyzed by gas chromatography, and the molecular weight, molecular weight distribution, and composition of the polymer were analyzed by gel permeation chromatography (GPC) under the conditions of Example 1. The content of trans-1,4-bonds in the butadiene moiety was analyzed using an infrared spectrophotometer, calculated using the Hampton method,
The melting point was determined by analysis using a differential thermal analyzer (DSC). *Manufactured by Lithium Corporation (n-Buty1, s-Bμty
approx. 1:1)

[Table] Example 11 An experiment was carried out in the same manner as in Examples 2 to 10, except that strontium dinonyl phenoxide was used as the catalyst component (a). The results are shown in Table-3.

[Table] Examples 12 to 20 and Comparative Examples 2 and 3 Capacity after replacing the inside with nitrogen gas
A 700 ml pressure glass bottle is charged with 120 g of a cyclohexane solution containing 20% by weight styrene that has been purified and dried in advance. Next, as catalyst components, 0.5 mmol of barium dinonyl phenoxide, the organic compounds of organomagnesium and lithium shown in Table 4 in the amounts shown in the same table, and 0.89 mmol of triethylaluminum were added, and the mixture was heated at 70°C. Polymerization was carried out with stirring for hours. At this point, a small amount of the polymerization solution was extracted and analyzed. Next, 280g of a cyclohexane solution containing purified and dried 1,3-butadiene at a concentration of 20% by weight was charged into the polymerization solution, and the mixture was further heated at 65°C for 3 hours. Polymerized. 1 after polymerization
Polymerization was stopped by adding ml of methanol, 0.3 parts by weight of BHT per 100 parts by weight of polymer was added, and the solvent was evaporated to recover the polymer. The results are shown in Table 4.

【table】

[Table] Examples 21 to 26 The capped capacity after replacing the inside with nitrogen gas is
A 700 ml pressure glass bottle is charged with 120 g of a cyclohexane solution containing 20% by weight styrene that has been purified and dried in advance. Next, as a catalyst component,
Adding 0.5 mmol of barium dinonyl phenoxide, 0.67 mmol of dibutylmagnesium ^* , 0.67 mmol of sec-butyl lithium, and the amounts of organic aluminum or organic zinc shown in Table 5,
Polymerization was carried out at 70°C with stirring for 3 hours. At this point, a small amount of the polymerization solution was extracted and analyzed. Next, a cyclohexane solution containing purified and dried 1,3-butadiene at a concentration of 20% by weight was added to the polymerization solution.
280g was charged, and polymerization was further carried out at 65°C for 3 hours.
After the reaction, 1 ml of methanol was added to stop the reaction, 0.3 parts by weight of BHT was added per 100 parts by weight of the polymer, and the solvent was evaporated to recover the polymer. The results are shown in Table-5. The analytical method is the same as that shown in Examples 2-10.

[Table] Examples 27 to 34 The capped capacity after replacing the inside with nitrogen gas is
A 700 ml pressure glass bottle is charged with 120 g of a cyclohexane solution containing 20% by weight styrene that has been purified and dried in advance. Next, as a catalyst component,
Barium dinonyl phenoxide 0.5 mmol, dibutylmagnesium ^* 0.67 mmol, sec-butyl lithium 0.67 mmol and triethyl aluminum
0.89 mmol was added and polymerization was carried out at 70° C. with stirring for 3 hours. At this point, a small amount of the polymerization solution is extracted and
conducted an analysis. Next, 280 g of a cyclohexane solution containing purified and dried 1,3-butadiene at a concentration of 20% by weight was added to the polymerization solution, and an additional 65 g of a cyclohexane solution was added.
Polymerization was carried out at ℃ for 3 hours. After the polymerization, the compounds shown in Table 5 were added as terminal coupling agents in the amounts shown in Table 5, and the mixture was reacted at 65°C for 1 hour. 1 ml after reaction
The reaction was stopped by adding methanol, 0.3 parts by weight of BHT per 100 parts by weight of the polymer was added, and the solvent was evaporated to recover the polymer. The results are shown in Table-6. The analytical method is the same as that shown in Examples 2-10.

[Table] Example 35 An experiment was carried out in the same manner as in Example 17, except that isoprene was used as the conjugated diene monomer.
The results are shown in Table-7.

【table】 [Brief explanation of drawings]

FIG. 1 shows an example of a copolymer according to the invention.
The results of analysis by GPC are shown.

Claims (1)

[Claims] 1. A vinyl aromatic product characterized by using (a), (b) and (c), or a composite catalyst obtained from (a), (b), (c) and (d). Aromatic vinyl monomers and conjugated diene monomers having two or more block chains with different compositions, which are obtained by sequentially polymerizing monomers selected from group monomers and conjugated diene monomers, or mixtures thereof. A method for producing a copolymer consisting of Here, the usage amount of each catalyst component is (c)
is 0.1 to 50 mmol per 100 g of total monomers, (a) is expressed as a molar composition ratio (a) / (c) = 0.005 to 10, (b) is expressed as a molar composition ratio (b) / (c ) = 0.1 to 10, (d) is (b)/(c) = 0 to 50 expressed as a molar composition ratio, and (a) is barium or strontium represented by general formulas () to (). Organic compound, (b) is general formula () ~
An organic compound of lithium represented by (), (c) an organomagnesium represented by the general formula (), (d)
is an organoaluminium represented by the general formula () or an organozinc represented by the general formula (). (R ¹ −X−) ₂ Me ……() R ³ −O(−CH ₂ CH ₂ −O) _a 〕 ₂ ---Me ……() R ⁸ OSO ₃ −) ₂ Me ……() R ⁹ SO ₃ −) ₂ Me ……() (wherein, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ are fat represents a group hydrocarbon group or an aromatic hydrocarbon group,
R ⁸ and R ⁹ represent an aliphatic hydrocarbon group and an aromatic hydrocarbon group, respectively, a and b represent an integer from 1 to 6, c represents an integer from 2 to 8, and X represents oxygen or sulfur. (Me represents barium _or strontium metal) R ¹⁰ (−Li) _d ... () R ¹¹ ( _-X -Li) _e ... () R ¹² −) _f Li ……(XI) (In the formula, R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and
R ¹⁶ represents an aliphatic hydrocarbon group or an aromatic hydrocarbon group, d, e, f and g represent an integer of 1 or more and 6 or less, h represents an integer of 2 or more and 8 or less,
x represents an oxygen or sulfur atom) (In the formula, R ¹⁷ and R ¹⁸ represent an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be the same group or different groups.) (In the formula, R ¹⁹ , R ²⁰ , and R ²¹ are selected from hydrogen, aliphatic hydrocarbon groups, or aromatic hydrocarbon groups, and may be the same or different groups, but all of them are hydrogen.) ) R ²² −Zn−R ²³ ...() (In the formula, R ²² and R ²³ are selected from hydrogen, an aliphatic hydrocarbon group, or an aromatic hydrocarbon group, and even if they are the same group, they are different) It doesn't matter if it's a group, but not all of it is hydrogen).