JP4376709B2 - Method for producing polyacrylonitrile-based polymer - Google Patents

Description

  The present invention relates to a method for producing a polyacrylonitrile-based polymer. More specifically, the present invention relates to a method for producing a polyacrylonitrile-based polymer having a high degree of stereoregularity.

  Conventionally, polar vinyl polymers having a polar group in the side chain are known to have various functions compared to non-polar vinyl polymers, such as polyacrylonitrile, polyvinyl alcohol (polyvinyl acetate), polyacrylamide, and polymethacrylic acid. Methyl has played an important role in the industrial field.

  To give higher-order functions and performance to these polar vinyl polymers, as with non-polar vinyl polymers, the primary structure of the resulting polymer, that is, the three-dimensional structure, molecular weight, end group control, or the realization of a strict block structure Precise design and control are essential.

  Conventionally, these polymers have been synthesized mainly by a free radical polymerization method in a bulk system. The free radical polymerization method uses highly active free radicals as growth species, and therefore, it is possible to easily realize adjustment of various high molecular weight substances under various polymerization conditions regardless of the structure of the monomer, whether aqueous or non-aqueous. it can. However, while free radical species are highly active, it is difficult to control the reactivity compared to other polymerization methods and it is difficult to realize the primary structure control of the polymer. Not in.

  On the other hand, primary structure control of non-polar polymers, especially control of steric structure, has already been realized by applying organometallic complex catalysts known as Zieglar-Natta catalysts, metallocene catalysts, etc. When the metal complex catalyst is applied, the polar group often becomes a catalyst poison, and the polymerization activity itself of the catalyst is deactivated, so the success example is limited. In particular, regarding stereoregular vinyl polymer polymerization by controlling the steric structure, polymerization of a methacrylic acid ester with a rare earth complex catalyst (for example, see Non-Patent Document 1), polymerization of a polar vinyl monomer (for example, see Non-Patent Document 2). ), Polymerization of methacrylic acid esters with a catalyst comprising a zirconocene complex and a boron compound (see, for example, Non-Patent Document 3), and stereoregular polymer polymerization has also been reported. However, these complexes, for example, acrylonitrile and other polar vinyl monomers other than methacrylic acid esters have poor stereoregularity and poor polymerization activity, and are unstable in air. It has not been industrialized.

  In addition, various reports have been made on the preparation of polymers with controlled stereoregularity by applying anionic polymerization to polar vinyl monomers. These include the polymerization conditions and side reactions to anionic growth species by side chain polar groups. Due to the factors, the practical polymer is poor in terms of the average molecular weight and yield of the polymer obtained. For example, polymerization of syndiotactic methacrylate by t-butyllithium and a trialkylaluminum-based initiator (for example, see Non-Patent Document 4) and alkylaluminum and a phosphine complex (for example, see Non-Patent Document 5) is known. However, the average molecular weight of the obtained polymer is 100,000 or less. When acrylonitrile is used as the polar vinyl monomer, an anionic polymerization catalyst comprising an alkaline earth metal alkylated product such as Mg or Be is allowed to act at 70 ° C., so that the isotactic content is about 50 to 70%. Have been successfully prepared (see, for example, Non-Patent Document 6, Patent Document 1, Patent Document 2, Patent Document 3, etc.), but these are anionic polymerizations and by-products due to side reactions of cyano groups Inevitably, the polymerization yield is about 10 to 30%.

  For these reasons, attempts have also been made to control the stereoregularity of the polymer in free radical polymerization most suitable for the polymerization of polar vinyl monomers. For example, in the past, high isotactic content polyacrylonitrile and high syndiotactic were obtained by using urea, bile acid derivatives, etc. as host molecules, adjusting the inclusion compound with the monomer, and performing radiation solid phase polymerization at low temperature. Polymethyl methacrylate was prepared (see, for example, Non-Patent Document 7).

  Recently, polyvinyl alcohol having a high isotactic and syndiotactic content has been reported by photopolymerizing and saponifying vinyl acetate at a low temperature using a bulky fluoroalcohol as a solvent and a monomer-containing molecule (for example, Non-patent document 8, Patent document 4, Patent document 5, etc.). There is also a report of isotactic-rich polyacrylonitrile photopolymerization using a porous inorganic compound such as zeolite as an inclusion molecule (see, for example, Non-Patent Document 9).

  However, these are poor in versatility because monomer species capable of functioning as a host molecule are limited by the type of host molecule. In addition, these inclusion host compounds function effectively only at a low temperature of −30 ° C. or less, and the inclusion compounds easily dissociate and decompose at room temperature. Therefore, it is necessary to perform photopolymerization at a low temperature, workability, In addition to lack of practicality in terms of cost, it is difficult to control high stereoregularity.

  On the other hand, when a polar monomer such as methacrylic acid ester is polymerized in the presence of zinc chloride, a conventional Lewis acid, the monomer and Lewis acid interact to change the polymerization rate and copolymerization with other nonpolar monomers. It was also known to do. However, in them, the intensity of interaction between the Lewis acid and the monomer is insufficient, so that satisfactory control of stereoregularity has not been achieved.

  In recent years, a rare Lewis metal trifluoromethanesulfonate, which is a strong Lewis acid and has a unique reaction activity, has been added to the monomer in an amount of about 0.1 equivalent (about the usual amount of catalyst used). There has been reported radical polymerization of acrylamide derivatives having a high syndiotactic and isotactic content by polymerization (see, for example, Non-Patent Document 10).

  However, in this case as well, polymerization at a low temperature of about −20 ° C. is necessary to express a satisfactory high stereoregularity, and monomers other than acrylamide, that is, methyl methacrylate, acrylonitrile, vinyl acetate, etc. The useful effects of polar vinyl monomers have not been observed as expected. For example, polyvinyl alcohol obtained by adding an organoaluminum compound as a Lewis acid to vinyl acetate and performing saponification after radical polymerization is at most 1 to 2% higher than ordinary radical polymerization, and the syndiotacticity of the triad is increased. (See, for example, Patent Document 6), and its practical utility is low.

  In addition, since Lewis acids containing rare earth metals are expensive, it is necessary to solve the problem of high cost, recovery and reuse process even if the amount used is 0.1 to 0.2 equivalent to the monomer. It is not suitable for mass polymerization in

  On the other hand, we have already contacted polar metal monomers such as acrylonitrile, methyl methacrylate, vinyl acetate, and 4-vinylpyridine with crystalline metal salts belonging to hexagonal or trigonal crystals to form inclusion complexes. It is proposed that a polymer rich in isotacticity can be obtained when radical polymerization is carried out by adding a radical polymerization initiator after dispersing in a hydrocarbon solvent typified by toluene or heptane and making it into a slurry. Patent Document 11).

  However, this method has problems that the radical initiator and the monomer are heterogeneous, the initiator efficiency is lowered, and the growth end radical is chain-transferred to the solvent, making it difficult to obtain a high molecular weight product.

JP-A-1-203406 JP-A-3-68606 JP-A-7-18012 JP 2000-26537 A JP 2000-44607 A Japanese Patent Laid-Open No. 2001-200008 “Journal of the American Chemical Society” (USA), 1992, 114, 12, p. 4908-4910 “Macromolecules” (USA), 1996, 29, 24, P.A. 8014-8016 “Macromolecules”, (USA), 1995, 28, 9, p. 3067-3073 “Polymer Preprints”, USA, 1988, Vol. 29, No. 2, p. 76-77 “Polymer Preprints Japan”, 1987, Vol. 36, No. 6, p. 3139 “(Polymer International) Polymer International”, 1994, Vol. 35, No. 2, p. 207-213 “Journal of the American Chemical Society” (USA), 1960, Vol. 82, No. 21, p. 5671-5678 “Macromolecules”, 1998, Vol. 31, No. 22, p. 7598-7605 “Materials Letter”, 2002, Vol. 53, No. 3, p. 180-185 “Journal of the American Chemical Society”, 2001, 123, 29, p. 7180-7181 “Polymer Preprints”, USA, 2002, 43, 2, P.A. 978-979

  Based on the above-described problems in the production technology of conventional stereocontrolled polar vinyl monomers, the present inventors have established general-purpose polymerization equipment and conditions (temperature, polymerization start) in anionic polymerization suitable for polymerization of polar vinyl monomers. The purpose of the present invention is to develop a stereoregular anionic polymerization method that can be applied with a high degree of stereoregularity, and to provide a method for producing a stereoregular polymer that is economically and industrially advantageous It is what.

  The present inventors conducted research on stereoregular anionic polymerization of polar vinyl monomers, and examined Lewis acidic layered compounds and base catalysts that interact with and include oxygen and nitrogen atoms in the polar monomers described above. went. As a result, surprisingly, when a base catalyst is added to a complex in which a monomer is coordinated to an inorganic layered compound belonging to Groups IIA to IIB of the periodic table, the complex efficiently starts by the Lewis base / acid interaction between the catalyst and the layered compound. It has been found that an agent can be dispersed, and then anionic polymerization can be carried out, whereby a high degree of stereoregularity control of a polar vinyl monomer can be easily and effectively performed without causing a chain transfer reaction.

That is, the object of the present invention is to
A monomer for polymerization selected from an acrylonitrile component or an unsaturated copolymerization component in which the acrylonitrile component accounts for 70% or more based on all components, a hexagonal system and / or a trigonal crystal of Group IIA to IIB of the periodic table as a template compound Absorbed by metal compounds belonging to the system to form a complex, and anionic polymerization is carried out in the presence of an organic amine using the complex as a base catalyst in the presence or absence of a solvent, on the basis of isotactic triad (mm%). This is achieved by a method for producing a polyacrylonitrile-based polymer having an isotacticity of 35% or more.

  According to the production method of the present invention, general-purpose polymerization equipment and conditions (temperature, polymerization initiator) can be applied in anionic polymerization suitable for polymerization of polar vinyl monomers, and high degree of stereoregularity can be controlled. Development of a stereoregular anionic polymerization method and a method for producing a stereoregular polymer that is economically and industrially advantageous can be provided.

Hereinafter, the present invention will be described in detail.
The polymerization monomer used in the present invention is a compound selected from an acrylonitrile component or an unsaturated copolymerization component mainly composed of an acrylonitrile component. Here, “mainly” means that the component is 50 based on all components. % Or more, preferably 70% or more, and more preferably 80 mol% or more (hereinafter, an unsaturated copolymer component mainly composed of an acrylonitrile component or an acrylonitrile component may be simply abbreviated as a polymerization monomer. ).

  In the present invention, conventionally known unsaturated copolymerization components other than the acrylonitrile component can be used. However, unsaturated carboxylic acids having a large anionic polymerization activity and / or esters or amide derivatives of unsaturated carboxylic acids, particularly acrylics. Particular preference is given to using acids, methacrylic acid, itaconic acid and / or their alkyl esters and alkylamides. As the alkyl ester, an ester having an alkyl group having 1 to 6 carbon atoms such as at least one group selected from methyl, ethyl, propyl, isopropyl, normal butyl, isobutyl, t-butyl group, and cyclohexyl can be preferably used.

  Further, as unsaturated copolymerization components other than acrylonitrile components, anionic polymerization active polar vinyl monomers such as methacrylonitrile, vinyl acetate, acrylamide, maleic anhydride, N-vinylpyrrolidone, styrene, vinyl pyridine, vinyl imidazole. Such aromatic vinyl compounds can also be preferably used.

  These unsaturated copolymer components other than the acrylonitrile component may be used alone or in combination, and acrylic acid, methacrylic acid, itaconic acid, or alkyl esters thereof, methacrylonitrile, vinyl acetate, acrylamide, maleic anhydride. At least one compound selected from the group consisting of acids, polar vinyl monomers such as N-vinylpyrrolidone, and aromatic vinyl compounds such as styrene, vinylpyridine, and vinylimidazole can be particularly preferably selected.

  Unsaturated copolymer components other than these acrylonitrile components can be present in amounts that do not destroy the coordination structure of the complex. The addition amount of the unsaturated copolymerization component to the template compound is 0 to 50 mol%, preferably 0 to 30 mol%, particularly preferably 0 to 20 mol%, based on the whole polymerization monomer. As a result of the copolymerization, a random copolymer having a random arrangement with acrylonitrile or a block copolymer in which a chain of an acrylonitrile chain and an unsaturated copolymerization component is formed is obtained.

  The final polymer is not only used alone as a material for fibers, films, and other molded products, but it can also be modified and functioned by blending and combining other materials depending on the type and structure of the copolymerization component. It can also be used as a prepolymer and subsequently applied to a copolymerization component with various monomers.

  The metal compound used as the template compound in the present invention belongs to groups IIA to IIB of the periodic table, and its crystal system is a hexagonal or trigonal crystal compound, that is, a halide or an oxide. And at least one compound selected from the group consisting of hydroxide, sulfide, nitrate, nitrite, sulfate, carbonate, thiosulfate, phosphate, aliphatic carboxylate and aromatic carboxylate be able to.

  The metal compound in the crystalline state has a structure in which a metal cation and a counter anion pairing with the metal cation are arranged in order, and the unsaturated copolymerization component other than acrylonitrile and acrylonitrile includes a carboxyl group, an amide group, or a carboxylic acid. It can coordinate to a metal cation via an unpaired electron on the oxygen atom or nitrogen atom contained in the ester group. At that time, the arrangement of the acrylonitrile and the unsaturated copolymer component other than acrylonitrile is regulated according to the order of the metal cation and the counter anion, the size, or the distance between the ions.

  The arrangement restriction is considered to depend on the type and crystal state of the metal compound to be selected, but the metallized compound in the crystalline state belonging to Groups IIA to IIB of the periodic table and having a crystal system of hexagonal or trigonal is isotopic. It is preferably used as a template compound for tactic stereocontrolled polymerization. Many of these hexagonal and trigonal metal compounds have a lamellar structure when viewed macroscopically, and acrylonitrile and unsaturated copolymer components are included between layers of crystalline metal compounds to form polar groups. Can be aligned in the same direction and regularly arranged. Examples of such metal compounds include calcium bromide hexahydrate, calcium iodide, calcium iodide hexahydrate, cobalt (II) chloride, cobalt (II) bromide, cobalt (II) iodide, iodine Cobalt (II) iodide hexahydrate, cesium nitrate, cadmium chloride, cadmium bromide, cadmium iodide, iron (II) chloride, iron (III) chloride, iron (II) bromide, iron (III) bromide, Iron (II) iodide, potassium disulfide, potassium nitrite dihydrate, lithium iodide trihydrate, magnesium chloride, magnesium bromide, magnesium hydroxide, manganese chloride (II), manganese bromide (II), Sodium nitrite, nickel chloride (II), tin sulfate dihydrate, titanium chloride (II), titanium chloride (III), vanadium chloride (II), vanadium bromide (II), vanadium bromide Indium (III), but zinc chloride, preferably magnesium chloride, magnesium bromide, cobalt chloride (II), particularly preferably magnesium chloride.

  These may be used as a mixture of two or more, and may be a so-called double salt such as alum or hydrotalcite in which two or more metal cations are present in a single crystal system. In the case of crystal systems other than hexagonal and trigonal crystals, that is, cubic, orthorhombic, or monoclinic metal compounds, regular arrangement of unsaturated copolymerization components other than acrylonitrile and acrylonitrile cannot be realized. Is essentially atactic.

  The monomer for polymerization is brought into contact with and absorbed into a crystalline metal compound in an inert gas atmosphere to form a complex. This step is preferably performed in an atmosphere of inert gas such as nitrogen or argon. When a mixed gas containing water or carbon dioxide such as air is used, it becomes an anionic polymerization initiator or the anion growth terminal is deactivated. In some cases, a polymer having a sufficient degree of polymerization may not be obtained.

  In the production method of the present invention, the molar ratio (A / M) between the polymerization monomer and the template compound is preferably 0.1 or more and less than 3.0, and (A / M) is 0.1 or more. If present, the amount of the polymerizing monomer coordinated to the crystalline metal compound is sufficient to give a high molecular weight product. Further, if (A / M) is less than 3.0, the maximum amount of the polymerizable monomer that can be absorbed and coordinated by the metal compound in the crystalline state is not exceeded, and no surplus monomer is generated. It can be remarkably suppressed, and the stereoregularity of the obtained polymer is further improved.

  In the production method of the present invention, the anionic polymerization can be carried out in the presence or absence (solid phase polymerization) of a solvent. When polymerization is carried out in the presence of a solvent, the polarity is low so as not to destroy the structure of the complex. If an aprotic solvent is used, there is no particular problem. Preferred examples include aliphatic hydrocarbons such as pentane, hexane, heptane, and octane, aromatic hydrocarbons such as benzene, toluene, and xylene, or dichloromethane, diethyl ether, and tetrahydrofuran. be able to.

  In the present anionic polymerization system, since the chain transfer to the solvent is less than that in radical polymerization, the resulting polymer is relatively easy to obtain a high molecular weight, but in particular, the viscosity average molecular weight (hereinafter simply abbreviated as Mv) with good mechanical properties. However, when it is intended to obtain a high molecular weight polyacrylonitrile polymer having a molecular weight of 100,000 or more and a copolymer thereof, it is preferable to perform solid phase polymerization.

  In the solid phase polymerization, as described above, a complex prepared by contacting a monomer for polymerization with a metal compound as a template compound in an inert gas atmosphere is polymerized as it is in an inert gas atmosphere in the presence of an anionic polymerization initiator. To be achieved.

  There are roughly two types of solid-phase polymerization methods. After adjusting the complex of the monomer and crystalline metal compound, an anionic polymerization initiator is dissolved in a small amount of an organic solvent and the anionic polymerization initiator is dissolved in the monomer in advance. The method of adding the product to the metal compound in the crystalline state can be mentioned.

  When the polymerization activity of the anionic initiator is high, it is preferable to use the former because the anionic polymerization in bulk occurs and the stereoregularity does not appear when the monomer and the initiator are mixed in advance without the metal compound. Further, when the activity of the anionic polymerization initiator is not so high, the latter method can be carried out by controlling the polymerization so as not to start by sufficiently cooling the monomer and the initiator when they are mixed. Considering the uniform distribution of the initiator, the latter is preferable, and therefore the latter is preferable when the polymerization initiation reaction can be controlled by temperature. During the addition, both a method of allowing the complex to stand and allowing it to absorb spontaneously and a method of giving an appropriate agitation to the complex are possible, but the agitation should not be so intense as to pulverize the complex.

  The anionic polymerization initiator in the present invention may be any one that is usually used in anionic polymerization. Such anionic polymerization initiators include lithium methoxide, sodium methoxide, potassium methoxide, lithium ethoxide, sodium ethoxide, potassium ethoxide, sodium isopropoxide, potassium butoxide, lithium tert. Metal alkoxides typified by butoxide, aluminum tributoxide, organometallic compounds typified by diethylmagnesium, triethylaluminum, phenyllithium, Grignard reagents typified by phenylmagnesium bromide, ethylmagnesium chloride, allylmagnesium iodide, lithium Metal amide compounds represented by amide, potassium succinimide, potassium acetamide, etc., triethylamine, tributylamine, methylpiperidine, morpholine, triethylenediamine, 1,8-diazabicyclo [5.4.0] undec-7-ene, etc. And organic amines represented by

  Among them, lithium tert. Particularly preferred examples include butoxide, aluminum tributoxide, diethylmagnesium, triethylaluminum, triethylamine, tributylamine, methylpiperidine, morpholine, triethylenediamine, 1,8-diazabicyclo [5.4.0] undec-7-ene and the like. it can.

  A temperature condition suitable for anionic polymerization is −80 ° C. or higher and lower than 150 ° C. Below −80 ° C., not only the polymerization reaction rate is extremely reduced, but also the energy consumption for cooling increases. Conversely, at 150 ° C. or higher, side reactions other than the polymerization reaction occur simultaneously, and the monomer dissociates as a gas from the crystalline metal compound, so that a sufficiently high molecular weight stereoregular polymer cannot be obtained.

  The complex that has completed the solid-phase polymerization is composed of a metal compound in a crystalline state and a stereoregular polymer component obtained by polymerization. There are several ways to separate the stereoregular polymer from the metal compound. When the metal compound is easily soluble, it can be removed from the stereoregular polymer by elution with water, methanol, ethanol or the like. On the other hand, when the metal compound is hardly soluble, it is isolated by eluting the stereoregular polymer with a polar organic solvent such as dimethyl sulfoxide, N, N′-dimethylformamide, N-methylpyrrolidone and reprecipitation. Is possible.

  Regarding the microstructure of the polyacrylonitrile-based stereoregular polymer thus obtained, the content of isotactic triad (mm) in which adjacent polar groups are aligned in a meso-meso configuration is aligned in a racemo-racemo configuration. It has a stereoregularity such that it is present in 35% or more in the entire microstructure including the syndiotactic triad (rr) and the mr (heterotactic triad) arranged in the meso-racemo arrangement. In the case of α-mono-substituted polar vinyl polymer such as polyacrylonitrile, the mm and / or rr content here refers to three types of three-dimensional structures of mm, mr, and rr in the 13C-NMR spectrum of α-carbon. It can be calculated from the peak intensity ratio based on it.

  In the case of a polymer having a substituent such as an alkyl group at the α-position as a copolymer component such as polymethyl methacrylate, the copolymer component is calculated from the three peak intensity ratios of mm, mr and rr of hydrogen atoms on the α-substituent. It is also possible. By exhibiting the stereoregular structure, physical and chemical properties such as mechanical properties, heat resistance, solvent resistance and chemical resistance of the polar polymer can be improved. Isotactic polyacrylonitrile can improve thermal and mechanical properties compared to atactic materials, and can selectively coordinate metal ions, which can be applied to metal adsorbing materials and conductive polymers. It is also useful for applications. When the mm and / or rr content is less than 50%, the fine structure contributes to the above-mentioned physical and chemical properties, and the effect on the expected function development is small or not linked.

Hereinafter, the present invention will be described in more detail with reference examples and examples. However, the present invention is not limited to the following reference examples and examples.
In Examples, the composition of the polymer is determined by ¹ H-NMR, and the stereoregularity (tacticity) is determined by ¹³ C-NMR measurement (270 MHz JNR-EX-270, manufactured by JEOL Datum Co., Ltd., solvent DMSO-d ₆ ). Then, isotactic triad (mm), syndiotactic triad (rr), and heterotactic triad (mr) were determined. The intrinsic viscosity [η] of the polymer was calculated by substituting ηsp / C measured in N, N′-dimethylformamide at 35 ° C. into the following empirical formula (1) using an S-40 standard Ubbelohde viscometer. did.
[Equation 1]
[Η] = 0.6712 × ηsp / C + 0.063 (1)

[Example 1]
The three-necked flask was replaced with dry nitrogen. Subsequently, 50 g of anhydrous magnesium chloride was placed in the three-necked flask under a dry nitrogen stream and kept at 0 ° C. or lower with an ice bath. A separately prepared three-necked flask was replaced with dry nitrogen, and 34.6 ml of acrylonitrile and 80 μl of 1,8-diazabicyclo [5.4.0] undec-7-ene (152.24, d = 1.02) were mixed. A monomer / initiator solution was obtained. This was added to anhydrous magnesium chloride cooled to −10 ° C. with a syringe to form a complex of A / M = 1/1. The three-necked flask containing this complex was sealed with a sealing tape, then placed in a thermostatic bath set at 25 ° C., and solid phase polymerization was performed at 25 ° C. for 24 hours. After solid phase polymerization, the complex was poured into methanol, and anhydrous magnesium chloride was dissolved and extracted and removed to collect polyacrylonitrile insoluble in methanol by filtration. After washing with ion exchanged water and acetone in that order, it was dried under reduced pressure at 40 ° C. for a whole day and night. The obtained polymer was 12.7 g (yield 45.5%). ^{When 13} C-NMR measurement was performed and the tacticity was quantified, it was mm / mr / rr = 60.3 / 29.3 / 10.4, and it was confirmed to have high isotacticity. The intrinsic viscosity [η] calculated based on ηsp / C measured in N, N′-dimethylformamide at 35 ° C. was 1.67.

[Example 2]
The three-necked flask was replaced with dry nitrogen. Subsequently, 50 g of anhydrous magnesium chloride was placed in the three-necked flask under a dry nitrogen stream and kept at 0 ° C. or lower with an ice bath. A separately prepared three-necked flask was replaced with dry nitrogen, and 34.6 ml of acrylonitrile and 80 μl of 1,8-diazabicyclo [5.4.0] undec-7-ene (152.24, d = 1.02) were mixed. A monomer / initiator solution was obtained. This was added to anhydrous magnesium chloride cooled to −10 ° C. with a syringe to form a complex of A / M = 1/1. Separately prepared 300 ml of dehydrated methylcyclohexane was added to this complex and mixed uniformly to form a slurry solution. The three-necked flask was sealed with a sealing tape and then placed in a thermostatic bath set at 25 ° C., and slurry polymerization was performed at 25 ° C. for 24 hours. Went. After polymerization, the complex was poured into methanol, and anhydrous magnesium chloride was dissolved and extracted and removed to collect polyacrylonitrile insoluble in methanol by filtration. After washing with ion exchanged water and acetone in that order, it was dried under reduced pressure at 40 ° C. for a whole day and night. The obtained polymer was 10.5 g (yield 37.6%). ^{When 13} C-NMR measurement was performed and tacticity was quantified, it was mm / mr / rr = 60.1 / 29.4 / 10.5, and it was confirmed to have high isotacticity. The intrinsic viscosity [η] calculated based on ηsp / C measured in N, N′-dimethylformamide at 35 ° C. was 1.32.

[Example 3]
In Example 1, 80 μl of 1,8-diazabicyclo [5.4.0] undec-7-ene (152.24, d = 1.02) was changed to 100 μl of tri-n-propylamine (143.27). Otherwise, 10.5 g of polyacrylonitrile (yield 37.6%) was obtained in the same manner. ^{When 13} C-NMR measurement was performed and the tacticity was quantified, it was mm / mr / rr = 59.0 / 30.0 / 11.0, and it was confirmed to have high isotacticity. The intrinsic viscosity [η] calculated based on ηsp / C measured in N, N′-dimethylformamide at 35 ° C. was 1.28.

[Example 4]
In Example 1, 13.2 g of polyacrylonitrile (yield 47.3%) was obtained in the same manner except that 50 g of anhydrous magnesium chloride (95.21) was changed to 96.7 g of anhydrous magnesium bromide (184.113). ) ^{When 13} C-NMR measurement was performed and the tacticity was quantified, it was mm / mr / rr = 59.0 / 30.0 / 11.0, and it was confirmed to have high isotacticity. The intrinsic viscosity [η] calculated based on ηsp / C measured in N, N′-dimethylformamide at 35 ° C. was 1.71.

[ Comparative Example 3 ]
The three-necked flask was replaced with dry nitrogen. Subsequently, 50 g of anhydrous magnesium chloride was placed in the three-necked flask under a dry nitrogen stream and kept at 0 ° C. or lower with an ice bath. Separately prepared 34.6 ml of acrylonitrile was added to anhydrous magnesium chloride cooled to 0 ° C. with a syringe to form a complex of A / M = 1/1. Separately, lithium tert. -0.042 g of butoxide (molecular weight 80.05) and 100 ml of dry n-heptane were mixed to form an initiator solution, which was added to an acrylonitrile / anhydrous magnesium chloride complex cooled to -20 ° C and stirred to obtain a slurry dispersion. It was adjusted. This slurry was placed in a thermostatic bath set at 15 ° C., and stirred for 24 hours for polymerization. After solid phase polymerization, the complex was poured into methanol, and anhydrous magnesium chloride was dissolved and extracted and removed to collect polyacrylonitrile insoluble in methanol by filtration. After washing with ion exchanged water and acetone in that order, it was dried under reduced pressure at 40 ° C. for a whole day and night. The obtained polymer was 11.1 g (yield 39.8%). ^{When 13} C-NMR measurement was performed and the tacticity was quantified, it was mm / mr / rr = 58.5 / 30.3 / 11.2, and it was confirmed to have high isotacticity. The intrinsic viscosity [η] calculated based on ηsp / C measured in N, N′-dimethylformamide at 35 ° C. was 1.34.

[Example 6]
The three-necked flask was replaced with dry nitrogen. Subsequently, 50 g of anhydrous magnesium chloride was placed in the three-necked flask under a dry nitrogen stream, and this was kept at −10 ° C. or lower with a methanol / ice bath. A separately prepared three-necked flask was replaced with dry nitrogen, and 34.6 ml (27.9568 g) of acrylonitrile (0.808), 2 ml (1.942 g) of methyl acrylate (d = 0.962), dibutyl itaconate (0. 985) 1.2 ml (1.182 g) and 0.059 g of triethylenediamine (112.17) were mixed at −10 ° C. to prepare a monomer / initiator solution. This was added to anhydrous magnesium chloride cooled to −10 ° C. with a syringe to form a complex of A / M = 1/1. The three-necked flask containing this complex was sealed with a sealing tape, then placed in a thermostatic bath set at 25 ° C., and subjected to solid phase polymerization as it was. After solid phase polymerization, the complex was poured into methanol, and anhydrous magnesium chloride was dissolved and extracted and removed to collect a polyacrylonitrile copolymer (31.0808) insoluble in methanol by filtration. After washing with ion exchanged water and acetone in that order, it was dried under reduced pressure at 40 ° C. for a whole day and night. The obtained polymer was 10.1 g (yield 32.5%). ^When the composition of the copolymer was estimated by ¹ H-NMR measurement, the acrylonitrile component, methyl acrylate component, and dibutyl itaconate component were 94.7%, 2.3%, and 3.0%, respectively. Moreover, when ¹³ C-NMR measurement was performed and tacticity was quantified, it was mm / mr / rr = 67.5 / 26.3 / 6.2, and it was confirmed to have high isotacticity. The intrinsic viscosity [η] calculated based on ηsp / C measured in N, N′-dimethylformamide at 35 ° C. was 1.35.

[Comparative Example 1]
In Example 1, polymerization was carried out under the same conditions except that anhydrous magnesium chloride was not used. ^When triad tacticity was quantified by ¹³ C-NMR measurement, it was mm / mr / rr = 25.8 / 49.0 / 25.2, and 10.9 g of substantially atactic polyacrylonitrile (yield 39.1). %) Was obtained. The intrinsic viscosity [η] obtained using an Ubbelohde viscometer in N, N′-dimethylformamide at 35 ° C. was 1.42.

[Comparative Example 2]
In Example 1, polymerization was carried out under the same conditions except that 58 g of calcium chloride belonging to the monoclinic system was used in place of anhydrous magnesium chloride. ^When triad tacticity was quantified by ¹³ C-NMR measurement, it was mm / mr / rr = 26.7 / 49.2 / 24.1, and 9.8 g of substantially atactic polyacrylonitrile (yield 35.2). %) Was obtained. The intrinsic viscosity [η] obtained using an Ubbelohde viscometer in N, N′-dimethylformamide at 35 ° C. was 1.38.

Claims (5)

A monomer for polymerization selected from an acrylonitrile component or an unsaturated copolymerization component in which the acrylonitrile component accounts for 70% or more based on all components, a hexagonal system and / or a trigonal crystal of Group IIA to IIB of the periodic table as a template compound Absorbed by metal compounds belonging to the system to form a complex, and anionic polymerization is carried out in the presence of an organic amine using the complex as a base catalyst in the presence or absence of a solvent, on the basis of isotactic triad (mm%). A method for producing a polyacrylonitrile-based polymer having an isotacticity of 35% or more.   The manufacturing method according to claim 1, wherein the template compound is a metal compound having a layered structure of a cadmium iodide type, a cadmium chloride type, and a molybdenum sulfide type.   The production method according to claim 1, wherein anionic polymerization is achieved by solid phase polymerization in the presence of an anionic polymerization initiator in the complex.   The manufacturing method of Claim 1 which makes the molar ratio (A / M) of the said monomer for polymerization and a template compound 0.1 or more and less than 3.0 in the said complex. Organic amine is a base catalyst, triethylamine, tributylamine, is either methyl piperidine, morpholine, triethylenediamine, 1,8-diazabicyclo [5.4.0] undec-7-ene, according to claim 1 Manufacturing method.