JPH0364526B2 - - 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. More 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] _IA metal compounds such as organolithium are used as polymerization catalysts, and by utilizing their living anion polymerization properties,
A technology for manufacturing a block copolymer of a vinyl aromatic monomer and a conjugated diene monomer by sequentially polymerizing a vinyl aromatic monomer and a conjugated diene monomer and carrying out an end coupling reaction if necessary. be.
Block copolymers obtained by this technology are used for footwear, plastic modifiers, and adhesives, but the trans bond content in the conjugated diene moiety is low, and the crystalline trans conjugated diene polymer block No block copolymer has 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 using a so-called Ziegler catalyst containing a transition metal as the main component (2) Production technology using an anionic polymerization catalyst system containing an alkaline earth metal compound as the main component (3) Catalyst containing a rare earth metal compound as the main component Among these, the first technology that uses transition metals such as nickel, cobalt, titanium, and vanadium as the main ingredients is
It is known that conjugated diene monomers can be polymerized in a highly stereoregular manner. However, it is difficult to produce block copolymers of conjugated diene monomers and vinyl aromatic monomers using this production technology because of the living nature of polymerization activity and low copolymerizability with vinyl aromatic monomers. Ta. As for 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 extremely low polymerization activity. It was hot. On the other hand, 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, there are various proposals for methods that combine organic acid salts of metal _A such as barium and strontium with other organometallic compounds. For example, barium di-tert-butoxide and organic lithium 47-3728), barium di-tert
-Butoxide and organomagnesium (Unexamined Japanese Patent Publication 1973-
48910) or a method of polymerizing a conjugated diene monomer using an organic compound of barium or strontium and an organic compound of organolithium and metal _B or _A (Japanese Patent Application Laid-open No. 52-30543). . However, although it is also possible to copolymerize a conjugated diene monomer and a vinyl aromatic monomer using a composite catalyst containing these _A metal compounds, the trans bond content of the conjugated diene moiety is
When attempting to obtain a crystalline polymer with high stereoregularity exceeding 75%, 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 end. 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. 1508-1983). 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 monomer It has been difficult to obtain block copolymers of vinyl aromatic monomers and vinyl aromatic monomers. [Problems to be Solved by the Invention] As mentioned above, in the technology using conventional polymerization catalysts, there are problems with the catalyst properties, so it is difficult to use conjugated diene monomers and vinyl aromatic monomers with high trans bond content. It has been extremely difficult to produce block copolymers with [Means and effects for solving the problems] Under these circumstances, the present inventors have conducted extensive studies on a method for producing a copolymer containing a crystalline trans-conjugated diene polymer block and a vinyl aromatic hydrocarbon polymer block. As a result, vinyl aromatic monomers were polymerized using a composite consisting of an organic compound of lithium and an organomagnesium as a polymerization catalyst to form a polymerization block of vinyl aromatic monomers, then a rare earth metal compound was added, and further conjugated The inventors have discovered that the desired block copolymer can be easily produced by block copolymerizing diene monomers, and have thus arrived at the present invention. That is, the present invention is directed to homopolymerizing a vinyl aromatic monomer using a composite catalyst consisting of an organic compound of lithium and an organomagnesium as described in the claims, or after homopolymerizing a vinyl aromatic monomer with one or more other vinyl aromatic monomers. After copolymerizing with the polymer or conjugated diene monomer, an organic acid salt of a rare earth metal, also as claimed, is added and the conjugated diene monomer is homopolymerized or with one or more other The present invention provides a method for producing a block copolymer, which comprises copolymerizing the block copolymer with a conjugated diene monomer or an aromatic vinyl monomer, and further adding and reacting a coupling agent if necessary. The block copolymers obtained in this way exhibit various excellent properties 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. . That is, (1) when the content of vinyl aromatic hydrocarbon is relatively small and the melting point of the conjugated diene block is below room temperature; it exhibits properties as a so-called thermoplastic elastomer. In this case, the conjugated diene block exhibits elongated 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 result is a resinous polymer with even higher hardness and strength and excellent rebound properties. In addition, this type of polymer is easily oriented and crystallized, so for example, if the glass transition temperature of the vinyl aromatic hydrocarbon block is higher than the melting point of the conjugated diene block, it can be molded at a temperature higher than the glass transition temperature of the vinyl aromatic hydrocarbon block. When the sample was deformed and cooled below the glass transition temperature of the vinyl aromatic hydrocarbon block and above the melting point of the conjugated diene block, this shape was frozen and maintained, and when it was heated again to above the melting point of the conjugated diene block, it was quickly molded. It exhibits excellent properties as a shape memory resin that allows it to recover the shape of the sample. (3) Furthermore, when the content of vinyl aromatic hydrocarbon is high; the thermoplastic resin has high hardness, high strength, and excellent impact resistance. SUMMARY OF THE INVENTION Therefore, the object of the present invention is to advantageously produce 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. be. The present invention will be explained in detail below. In the production method of the present invention, in the first stage of polymerization, prior to the addition of the rare earth compound, vinyl aromatic monomers are polymerized using a composite consisting of an organic compound of lithium and an organomagnesium as a polymerization catalyst. The organic compound of lithium used is selected from organic lithium or organic acid salts of lithium represented by the following general formulas () to (). R ¹ (Li) _a ... () R ² (XLi) _b ... () R ³ O (CH ₂ CH ₂ O) _c Li ... () (Here, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ represent an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and a, b, c and d are 1 or more and 6 or less. (e represents an integer from 2 to 8, and X represents an oxygen or sulfur atom.) Examples of the 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-dilithio-1,1,2,2-tetraphenylethane, 1,3-bis(1-lithio-
1,3-dimethylpentyl)benzene, and the like. Preferably n-butyllithium, sec
-butyllithium, tert-butyllithium, 1,
Examples include organic lithium compounds such as 3-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 () 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 lithium 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 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 the general formula () include lithium salts of cyclic imines such as ethyleneimine, triethyleneimine, pyrrolidine, piperidine, and hexamethyleneimine. Particularly preferred organic compounds of lithium are alkyllithiums having 2 to 10 carbon atoms, such as n-butyllithium, sec-buterlithium, and sio-amyllithium. The organic magnesium used is represented by the following general formula (). (Here, R ⁸ and R ⁹ represent an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be the same group or different groups.) In addition, organomagnesium 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. The amount of organomagnesium used depends on the molecular weight of the desired polymer, but is generally
0.1-50 mmol per 100g, preferably 0.5-5
It is in the mmol range. If the amount of organomagnesium used is less than 0.1 mmol, it is generally not preferred because the polymerization activity of the catalyst is markedly reduced and the molecular weight of the resulting polymer is markedly increased, making processing difficult. Furthermore, if the content of organomagnesium is 50 mmol or more, the molecular weight of the resulting polymer will be significantly low, which is generally not preferred. Also, the amount of lithium organic compound used is
Expressed as the molar ratio of lithium and magnesium, Li/
Mg=0.1 to 10, preferably 0.5 to 2
is within the range of If the amount of lithium is less than Li/Mg=0.1, the polymerization activity during the vinyl aromatic monomer polymerization prior to the addition of the rare earth metal compound will drop significantly, which is not preferable. In addition, when the amount of lithium is greater than Li/Mg = 10, the proportion of 1,4-trans bonds in the conjugated diene decreases significantly during the step of adding a rare earth metal compound and polymerizing the conjugated diene monomer, resulting in a polymer obtained. becomes amorphous, and the object of the present invention cannot be achieved. In the first stage of polymerization, the polymer chain polymerized by a composite catalyst consisting of an organic compound of lithium and an organomagnesium is always homopolymerized with a vinyl aromatic monomer whose glass transition temperature is higher than room temperature. Alternatively, it must contain a polymer block copolymerized with other vinyl aromatic monomers or conjugated dienes. However, at the same time, one conjugated diene polymer or a random or tapered copolymer chain of a conjugated diene and a vinyl aromatic monomer that can be copolymerized before or after the polymerization of a polymer block of vinyl aromatic monomers is added. It may include the above. 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. can be mentioned. A particularly preferred vinyl aromatic monomer is styrene. Examples of conjugated dienes that can be copolymerized include butadiene, isoprene, piperylene, and the like. Polymerization can be carried out without a solvent or in the presence of a solvent. In the latter case, usable solvents include n-pentane, n-hexane, n-heptane,
Examples include aliphatic or alicyclic hydrocarbons such as cyclohexane, and aromatic hydrocarbons such as benzene and toluene. Further, the solvent may partially contain a polar organic compound such as tertiary aminos and ethers that do not contain active hydrogen for the purpose of promoting the polymerization reaction and improving the solubility of the catalyst. Polymerization temperature is -30℃~150℃, preferably 50℃~
Performed at 120°C. Although the polymerization reaction format is not particularly limited, a batch method is generally preferred. In the production method of the present invention, generally after polymerizing the bicarbonate aromatic hydrocarbon polymer block, an organic acid salt of a rare earth metal is added and reacted, and then the crystalline trans-conjugated diene polymer block in the second step is added. However, if necessary, substantially the same result can be obtained by simultaneously adding a rare earth metal organic acid salt and a conjugated diene monomer. The rare earth metal organic acid salts used are salts of organic acids represented by the following general formulas () to (). ^R10 −XH……() (Here, R ¹⁰ , R ¹¹ and R ¹⁴ to R ¹⁷ represent an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
R ¹² represents an aromatic hydrocarbon group, R ¹³ represents an aliphatic hydrocarbon group, and R ¹⁸ to ^{R 21} represent an aliphatic hydrocarbon group, an aromatic hydrocarbon group, an alkoxy group, or a phenoxy group. X represents an oxygen atom or a sulfur atom. Furthermore, f, g, h and i represent integers of 1 or more and 6 or less. ) The above general formula () represents alcohol, thioalcohol, phenol or thiophenol. Examples of these are methyl alcohol, ethyl alcohol, n-propyl alcohol, iso-
propyl alcohol, tert-butyl alcohol,
tert-amyl alcohol, n-hexyl alcohol, cyclohexyl alcohol, allyl alcohol, 2-butenyl alcohol, 3-hexenyl alcohol, 2,5-decadienyl alcohol, benzyl alcohol, phenol, catechol, 1
-naphthol, 2-naphthol, 2,6-di-
tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, 2,4,6-tri-tert-butylphenol, 4-phenylphenol, ethanethiol, 1-butanethiol, 2
-pentanethiol, 2-iso-butanethiol,
Examples include thiophenol, 2-naphthalenethiol, cyclohexanethiol, 3-methylcyclohexanethiol, 2-naphthalenethiol, benzenemethanethiol, 2-naphthalenemethanethiol, and the like. The general formula () represents a carboxylic acid or a sulfur congener. Examples of these are isovaleric acid, caprylic acid, octanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid,
linoleic acid, cyclopentanecarboxylic acid, naphthenic acid, ethylhexanoic acid, pivalic acid, versatic acid (a synthetic acid composed of a mixture of isomers of C10 monocarboxylic acids sold by Siel Chemical),
Examples include phenylacetic acid, benzoic acid, 2-naphthoic acid, hexanethiolic acid, 2,2-dimethylbutanethionic acid, decanethionic acid, tetradecanethionic acid, and thiobenzoic acid. General formula () represents alkylarylsulfonic acid. Examples include dodecylbenzenesulfonic acid, tetradecylbenzenesulfonic acid, hexadecylbenzenesulfonic acid, octadecylbenzenesulfonic acid, dibutylnaphthalenesulfonic acid, n
-hexylnaphthalene sulfonic acid, dibutylphenyl sulfonic acid, etc. General formula (XI) represents a monoalcohol ester of sulfuric acid. Examples of these include sulfuric monoester of lauryl alcohol, sulfuric monoester of oleyl alcohol, sulfuric monoester of stearyl alcohol, and the like. General formula (XII) represents a phosphoric diester of an ethylene oxide adduct of alcohol or phenol. Examples of these are phosphoric diesters of ethylene oxide adducts of dodecyl alcohol, phosphoric diesters of ethylene oxide adducts of octyl alcohol, phosphoric diesters of ethylene oxide adducts of stearyl alcohol, and phosphoric diesters of ethylene oxide adducts of oleyl alcohol. Examples include acid diesters, phosphoric esters of ethylene oxide adducts of nonylphenol, and phosphoric esters of ethylene oxide adducts of dodecylphenol. The general formula () represents a phosphorous diester of an ethylene oxide adduct of alcohol or phenol. Examples of these are the phosphite diester of the ethylene oxide adduct of dodecyl alcohol, the phosphite diester of the ethylene oxide adduct of stearyl alcohol, the phosphite diester of the ethylene oxide adduct of stearyl alcohol, and the ethylene oxide of nonylphenol. Examples include phosphorous acid diester of an adduct, phosphorous acid diester of an ethylene oxide adduct of dodecylphenol, and the like. General formula () represents a pentavalent organic phosphoric acid compound. Examples include dibutyl phosphate, dipentyl phosphate, dihexyl phosphate, diheptyl phosphate, dioctyl phosphate, bis(1-methylheptyl) phosphate, bis(2-ethylhexyl) phosphate,
dilauryl phosphate, dioleyl phosphate, diphenyl phosphate, bis(p-nonylphenyl) phosphate,
(Butyl) phosphate (2-ethylhexyl), (1-methylheptyl) phosphoric acid (2-ethylhexyl),
Phosphoric acid (2-ethylhexyl) (p-nonylphenyl), monobutyl 2-ethylhexylphosphonate, mono-2-ethylhexyl 2-ethylhexylphosphonate, mono-2-ethylhexyl phenylphosphonate, mono-2-ethylhexyl 2-ethylhexylphosphonate, Mono-p-nonylphenyl 2-ethylhexylphosphonate, dibutylphosphinic acid, bis(2-ethylhexyl)phosphinic acid, bis(1-methylheptyl)phosphinic acid, dilaurylphosphinic acid, dioleylphosphinic acid, diphenylphosphinic acid Inic acid, bis(p-nonylphenyl)phosphinic acid, butyl(2-ethylhexyl)phosphinic acid, (2-ethylhexyl)(1-methylheptyl)phosphinic acid, (2-
Examples include ethylhexyl)(p-nonylphenyl)phosphinic acid. General formula () represents a trivalent phosphoric acid compound. Examples of this include bis(2-ethylhexyl) phosphate, bis(1-methylhexyl) phosphate, and 2-ethylhexyl phosphate.
Examples include mono-2-ethylhexyl ethylhexylphosphonate and bis(2-ethylhexyl)phosphinic acid. Rare earth metals that can be used are lanthanide elements with an atomic number of 57 to 71, preferably 57 to 64.
Particularly preferred are lanthanum, cerium, neodymium and samarium. These rare earth metals do not need to have particularly high purity, and may be a mixture with other rare earth elements, or may contain a small amount of metal elements other than rare earth elements. Furthermore, the rare earth metal organic acid salt may contain a small amount of unreacted organic acid. The amount of organic acid salt of rare earth metal used is expressed as a molar ratio with respect to the organic magnesium used.
= in the range of 0.01 to 1, preferably in the range of 0.05 to 0.5. When adding an organic salt of a rare earth metal, from an organic compound of lithium represented by the general formulas () to () above, an organomagnesium represented by the general formula (), an alkyl group having 1 to 10 carbon atoms, A compound selected from trialkyl aluminum or dialkyl zinc having 1 to 10 carbon atoms is preliminarily converted into an organic acid salt of a rare earth metal in order to increase the 1,4-trans bond of the conjugated diene or to promote the living growth of the reaction terminal. They may be mixed or added directly to the polymerization system. Further, in order to promote the polymerization reaction, a polar organic compound having no active hydrogen selected from tertiary amines or ethers may be newly added to the polymerization system. Examples of conjugated diene monomers that can be used include 4-carbon monomers such as butadiene, isoprene, and piperylene.
-12 conjugated dienes alone or mixtures thereof, with butadiene and isoprene being particularly preferred. The polymerization temperature in the second stage of polymerization depends on the structure of the crystalline trans-conjugated diene polymer block in the target copolymer, but is carried out at -30°C to 150°C, preferably 30°C to 100°C. . After the polymerization reaction is completed, depending on the desired polymer, further coupling with a coupling agent may be possible, thereby improving the physical properties of the resulting polymer. As the coupling agent, there can be used a coupling agent that is generally used in the terminal coupling reaction in anionic polymerization of conjugated dienes. Examples of coupling agents that can be used include multiepoxides, multiisocyanates, multiimines, multialdehydes, 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; multihalogenated tin compounds such as tetrachlortin, trichlormonomethyltin, and trichlormonoethyltin; These are ester compounds such as diphenyl carbonate and diethyl adipate. The amount of coupling agent used is considered to be the optimum amount for maximum branching if the amount is equivalent to the organic metal used.
However, any range of coupling agent amounts may 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 and antioxidants known in the art, and by methods known in the art. Particularly preferred examples of stabilizers and antioxidants include 2,6-di-
Examples include tert-butyl-4-methylphenol, tri-nonylphenyl phosphate, phenyl-β-naphthylamine, NN'-dialkyl-diphenylamine, and N-alkyl-diphenylamine. 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. 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 provides various excellent properties depending on the purpose, such as 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. [Examples] 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. 0.0113 mol of dibutylmagnesium ^* , 0.0113 mol of sec-butyllithium, and 0.034 mol of tetrahydrofuran (THF) as a polymerization accelerator were added at 65°C.
Polymerization was carried out for 3 hours. 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, and the number average molecular weight n = 8900 as determined by gel permeation chromatography (GPC) analysis, and the ratio to the weight average molecular weight. The molecular weight distribution shown by w/n was 1.16. The GPC measurement conditions are as follows. (a) GPC = Shimadzu LC-6A (b) Developing solution = THF (c) Column temperature = 40°C Next, after adding 0.0023 mol of lanthanum metal bis(2-ethylhexyl) phosphate to the polymerization solution, 3.5 kg of a cyclohexane solution containing purified and dried 1,3-butadiene at a concentration of 20% by weight 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 98%. Further, the polymer at this point was a polymer mixture containing a large amount of styrene-butadiene diblock polymer, as is clear from the GPC measurement results shown in FIG. The bonded styrene concentration distribution in FIG. 1 was calculated by measuring the molecular weight distribution by correcting the styrene concentration from the refractive index in GPC and measuring the styrene concentration from the ultraviolet absorbance. The polymer as a whole has Mn=32600, w/
n=1.40. 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 calculated from these GPC measurement results was 87%. The polymerization solution was further charged with diphenyl carbonate as a terminal coupling agent in an amount equimolar to the amount of magnesium remaining in the polymerization vessel, and the mixture was reacted at 65°C for 1 hour. As a result of this coupling reaction, the molecular weight of the polymer was n=64000, w/n=1.45, and a significant increase in molecular weight was observed. The final polymer recovery rate was 97%. *Manufactured by Lithium Corpo (n-Butyl, s-Butyl approx. 1:1) Comparative Example 1 Reaction was carried out under exactly the same conditions as in Example 1, except that lanthanum metal bis(2-ethylhexyl) phosphate was not added during polymerization. did. Moreover, the final polymer recovery rate was 99%. Table 1 shows the polymerization results and the properties of the obtained polymer. Comparative Example 2 All of the polymerization monomers were butadiene, and at the start of polymerization, a solution of butadiene in cyclohexane was added to 50% of the total amount.
Kg, dibutylmagnesium, sec-butyllithium, lanthanum metal bis(2-ethylhexyl) phosphate as catalyst components, and THF as a polymerization accelerator were added in the same amounts as in Example 1, and polymerization was carried out at 65° C. for 3 hours. The post-polymerization coupling reaction was carried out in the same manner. The final polymer recovery rate was 98%. Table 1 shows the polymerization results and the properties of the obtained polymer. Comparative Example 3 A reaction was carried out under exactly the same conditions as in Example 1, except that lanthanum metal bis(2-ethylhexyl) phosphate was added simultaneously with organomagnesium, organolithium, etc. during styrene polymerization. The conversion rate during styrene polymerization was extremely low at 3%, and the final butadiene conversion rate was 65%.

【table】

[Table] *1 Measured by differential thermal analyzer *2 150℃, weight 2.16Kg
*3 Measured according to JISK-6301 From Table 1, styrene produced by the method of the present invention.
It can be seen that the butadiene block copolymer has unique properties. That is, it exhibits crystallinity based on the trans-polybutadiene moiety, and has the characteristics of having high hardness, modulus, tensile strength, and impact resilience. It also showed a significantly large residual elongation at break, but when heated to 75°C, above the melting point, it quickly shrunk and recovered its original shape. Examples 2 to 10 and Comparative Examples 4 and 5 After replacing the inside with nitrogen gas, the capped capacity was
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, the organic compounds of organomagnesium and lithium shown in Table 2 were added in the amounts shown in the same table.
Polymerization was carried out with stirring for hours. At this point, a small amount of the polymerization solution was extracted and analyzed. Next, 0.15 mmol of bis(2-ethylhexyl) phosphate of lanthanum metal was added to the polymerization solution, and then 280 g of a cyclohexane solution containing purified and dried 1,3-butadiene at a concentration of 20% by weight was added, and the mixture was further heated at 65°C.
Polymerization was carried out 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 results are shown in Table-2.
The polymerization conversion rate of styrene and butadiene was determined by gas chromatography analysis, the molecular weight of the polymer,
The molecular weight distribution and polymer composition were analyzed by gel permeation chromatography (GPC) under the conditions of Example 1, and the trans-1,4-bond content of the butadiene moiety in the polymer was determined using an infrared spectrophotometer. The melting point was determined by analysis using a differential thermal analyzer (DSC).

【table】

【table】

[Table] Examples 11 to 17 and Comparative Example 6 Capacity after replacing the inside with nitrogen gas
A 700 ml pressure-resistant glass bolt is charged with 120 g of a cyclohexane solution containing previously purified and dried styrene at a concentration of 20% by weight. Next, 0.67 mmol of dibutylmagnesium ^* and 0.67 mmol of sec-butyllithium were added as catalyst components, and polymerization was carried out at 65°C for 3 hours. At this point, a small amount of the polymerization solution was extracted and analyzed. Next, bis(2-ethylhexyl) phosphate of the rare earth metal shown in Table 3 was added to the polymerization solution.
After adding 0.15 mmol of salt, purified and dried 1.
A cyclohexane solution containing 3-butadiene at a concentration of 20% by weight was charged, and polymerization was further carried out at 65°C for 3 hours. After polymerization, the polymerization was stopped by adding 1 ml of methanol, and the concentration was 0.3 per 100 parts by weight of the polymer.
Parts by weight of BHT were added, and the solvent was evaporated to recover the polymer. In Comparative Example 6, polymerization was carried out in exactly the same manner except that the rare earth metal salt was not added. The analysis method is the same as in Examples 2-10. The results are shown in Table-3. *Manufactured by Lithium Corpo (n-Butyl, S-Butyl
approximately 1:1)

[Table] Examples 18 to 26 Examples 11 to 26 except that lanthanum metal salts of organic acids shown in Table 4 were used as organic acid salts of rare earth metals.
It was carried out in exactly the same manner as in 17. The results are shown in Table 4.

【table】

[Table] ｜
C ₂ H ₅
Examples 27-34 After replacing the inside with nitrogen gas, the capped capacity is
A 700 ml pressure-resistant glass bolt is charged with 120 g of a cyclohexane solution containing previously purified and dried styrene at a concentration of 20% by weight. Next, 0.67 mmol of dibutylmagnesium and 0.67 mmol of sec-butyllithium were added as catalyst components, and polymerization was carried out at 65°C for 3 hours. At this point, a small amount of the polymerization solution was extracted and analyzed. Next, 0.15 mmol of bis(2-ethylhexyl) phosphate of lanthanum metal was added to the polymerization solution, and then a cyclohexane solution containing purified and dried 1,3-butadiene at a concentration of 20% by weight was added, and the mixture was further heated at 65°C. Polymerization was carried out 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. After the reaction, 1 ml of methanol was added to stop the reaction, 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-5. The analytical method is the same as that shown in Examples 2-10.

【table】

[Table] Example 35 The same procedure as in Example 7 was carried out except that isoprene was used as the conjugated diene monomer. Table 6 of the results
Shown below.

【table】 [Brief explanation of drawings]

FIG. 1 is a diagram (graph) showing the GPC measurement results of the polymer produced in Example 1.

Claims (1)

[Scope of Claims] 1 Consists of an organic compound of lithium represented by the following general formulas () to () and an organic magnesium represented by the following general formula () in an amount of 0.1 to 50 mmol per 100 g of total monomers, and The composition of organic compounds and organomagnesium is expressed in molar ratio Li/Mg.
= After homopolymerization of a vinyl aromatic monomer or copolymerization with one or more other vinyl aromatic monomers or conjugated diene monomers by a composite catalyst in the range of 0.1 to 10. , the following general formula () ~ (
) is added in an amount such that the molar ratio of rare earth metal/Mg is in the range of 0.01 to 1, and the conjugated diene monomer is homopolymerized, or one or more other A method for producing a block copolymer, which comprises copolymerizing with a conjugated diene monomer or an aromatic vinyl monomer, and further adding and reacting a coupling agent if necessary. R ¹ (Li) _a ... () R ² (XLi) _b ... () R ³ O (CH ₂ CH ₂ O) _c Li ... () (Here, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ represent an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and a, b, c and d are 1 or more and 6 or less. (e represents an integer from 2 to 8, and X represents an oxygen or sulfur atom.) (Here, R ⁸ and R ⁹ represent an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be the same group or different groups.) R ¹⁰ −XH... () (Here, R ¹⁰ , R ¹¹ and R ¹⁴ to R ¹⁷ represent an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
R ¹² represents an aromatic hydrocarbon group, R ¹³ represents an aliphatic hydrocarbon group, and R ¹⁸ to ^{R 21} represent an aliphatic hydrocarbon group, an aromatic hydrocarbon group, an alkoxy group, or a phenoxy group. X represents an oxygen atom or a sulfur atom. Furthermore, f, g, h and i represent integers of 1 or more and 6 or less. )