JP4616593B2 - Stereoregular polyacrylonitrile-based polymerization composition and method for producing the same - Google Patents

Description

  The present invention relates to a stereoregular polyacrylonitrile-based polymerization composition and a method for producing the same. Furthermore, an isotactic triad (hereinafter referred to as a polymer) containing a specific highly isotactic polyacrylonitrile chain unit and a monomer structural unit mainly composed of an unsaturated copolymer component mainly composed of acrylonitrile or acrylonitrile. The present invention relates to a stereoregular polymerization composition having an isotacticity of 35% or more on the basis and a method for producing the polymerization composition.

  Polyacrylonitrile (hereinafter sometimes abbreviated as PAN) has excellent texture, bulkiness and moisture retention during fiber molding, so it is used as a fiber for clothing, and its chemical structure changes due to heat treatment of the molded fiber. In order to form an insoluble and infusible flame-resistant annular structure, it is widely used as a precursor for heat-resistant fiber materials and carbon fibers.

  Conventionally, PAN has been produced by polymerizing acrylonitrile by free radical polymerization using a radical polymerization initiator or anionic polymerization using an anionic polymerization initiator. According to the analysis of the fine structure, that is, the stereochemical structure by the nuclear magnetic resonance spectrum measurement (hereinafter sometimes abbreviated as NMR), the PAN obtained by these conventional methods has the stereoregularity (hereinafter referred to as the molecular chain). , Sometimes referred to as tacticity).

  Therefore, it has been pointed out that when the obtained PAN is molded into a fiber or film, the crystallinity is low and the mechanical properties and / or heat resistance is lacking. PAN with excellent stereoregularity, especially for fibers, which has low dimensional stability, tensile strength, and elastic modulus, and is limited to high-performance / high-performance fibers, industrial materials, and space engineering. The establishment of an industrial manufacturing method has been studied.

  In an attempt to control the stereoregularity of polymers in free radical polymerization, which is most suitable for the polymerization of polar vinyl monomers such as acrylonitrile, in the past, urea and bile acid derivatives were used as host molecules to adjust the inclusion compounds with the monomers. Later, polyacrylonitrile having a high isotactic content was prepared by performing radiation solid phase polymerization at a low temperature (see Non-Patent Document 1).

  In recent years, there has also been a report of isotactic rich polyacrylonitrile photopolymerization using porous inorganic compounds such as zeolite as inclusion molecules (Non-patent Document 2).

  However, these are limited in the combination of monomers / host molecules capable of functioning as a host molecule, and lack versatility. In addition, these inclusion host compounds function effectively only at a low temperature of −30 ° C. or less, and the inclusion compounds are easily dissociated and decomposed at room temperature. Therefore, it is necessary to perform photopolymerization at a low temperature. Therefore, not only is it lacking in practicality in terms of workability and cost, but also high degree of stereoregularity control is difficult.

  In recent years, high syndiotactic properties have been obtained by adding about 0.1 equivalent amount (about catalytic amount) of rare earth metal trifluoromethanesulfonate, which is a strong Lewis acid and exhibiting a unique reaction activity, to the monomer and polymerizing it. Radical polymerization of acrylamide derivatives with tick and isotactic content has been reported (for example, see Non-Patent Document 3).

  However, also in this case, UV irradiation polymerization at a low temperature of about −20 ° C. is necessary to express a satisfactory high stereoregularity, lacking applicability to a practical polymerization process, and expected for monomers such as acrylonitrile. The effect of expression of stereoregularity is not recognized. 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 has been found that a polymer having a high isotacticity can be obtained by adding a radical polymerization initiator to a slurry after being dispersed in a hydrocarbon solvent typified by toluene or heptane and then adding a radical polymerization initiator. . (Non-Patent Document 4).

  However, even in this method, since a molecular complex composed of a monomer and a crystalline metal salt is polymerized, it is necessary to separate and recover the polymer and the metal salt after polymerization, which requires a large number of steps. Further manufacturing process improvements were needed.

  On the other hand, steric control of PAN using anionic polymerization has also been studied. For example, a method of polymerizing acrylonitrile in a polar or nonpolar solvent using a complex of an alkoxide and an amide compound of an alkali metal as a polymerization initiator is known (see Non-Patent Document 5).

  However, the PAN obtained by this method has a molecular weight of about several thousand to 10,000, and a PAN having a molecular weight of about 100,000 capable of expressing sufficient mechanical properties cannot be obtained. In recent years, polyacrylonitrile having an isotactic content of about 50 to 70% by reacting acrylonitrile with an anionic polymerization catalyst containing an alkaline earth metal alkylated product such as Mg or Be at 70 ° C. (See Non-Patent Document 6 and Patent Documents 1 to 3).

  However, this system is anionic polymerization at a high temperature, and it is unavoidable to mix by-products due to side reactions of cyano groups, and the polymerization yield is about 10 to 30%. In order to produce highly isotactic PAN by anionic polymerization, it is indispensable to use a highly toxic Be-based catalyst, and it is difficult to completely separate and remove the catalyst from the produced polymer. The impact is concerned and it is not used in reality.

  Various polar vinyl polymers, including polyacrylonitrile, have been synthesized primarily by free radical polymerization methods in bulk systems. Free radical polymerization uses highly active free radicals as growth species, and therefore, it is possible to easily realize the adjustment of various high molecular weight substances under various polymerization conditions regardless of the structure of the monomer, whether aqueous or non-aqueous. . As mentioned above, free radicals are highly active, but it is difficult to control the reactivity compared to other polymerization methods and it is difficult to control the primary structure of the polymer. Has not reached.

  In order to control the stereoregularity by free radical polymerization, many studies have been made on methyl methacrylate so far. For example, as a method for controlling stereoregularity by radical polymerization, a method in which a part of the monomer is substituted in advance with a bulky substituent and the substituent is replaced after polymerization has been reported. There was a problem that it was increased and the cost was high.

  Similarly, techniques relating to stereoregularity control using radical polymerization have been disclosed (see, for example, Patent Documents 4 to 6), but these techniques are isotactic using isotactic poly (methyl methacrylate). It produces a stereocomplex composed of tick poly (methyl methacrylate) and syndiotactic poly (methyl methacrylate), and it does not disclose the production of a polymer composed solely of syndiotactic poly (methyl methacrylate). . A method of polymerizing syndiotactic poly (methyl methacrylate) by radical polymerization of methyl methacrylate in a protic solvent such as fluoroalcohol has been reported (see Non-Patent Document 7). The method is expensive and has a problem of using a large amount of a fluorinated compound that adversely affects the environment as a solvent. Furthermore, since the obtained polymer must be reprecipitated or the solvent must be evaporated to recover the polymer, there is a problem that the production of the polymer is not easy.

  On the other hand, various reports have been made in the past regarding stereoregular polymer polymerization using a stereoregular polymer itself such as polyacrylamide (PAAm) and stereoregular polymethacrylic acid (PMA) as a template. For example, with respect to stereoregular polymer polymerization using stereoregular polymethyl methacrylate (PMMA) as a template, a technique for bulk polymerization of methyl methacrylate in the presence of syndiotactic PMMA is described (see Non-Patent Document 8). .

  On the other hand, a technique for polymerizing methyl methacrylate in dimethylformamide in the presence of syndiotactic PMMA has also been reported (see Non-Patent Document 9).

  Furthermore, a technique is also disclosed in which syndiotactic PMMA is swollen with a methyl methacrylate monomer and radically polymerized in a bulk form (see Non-Patent Document 10).

  However, these techniques produce a stereocomplex composed of isotactic PMMA and syndiotactic PMMA, and production of a polymer composed only of isotactic PMMA is not disclosed, and the radical polymerization temperature is high. Therefore, sufficient stereoregularity cannot be controlled, and the tacticity of the obtained polymer is not satisfactory.

  In addition, syndiotactic PMMA having a syndiotacticity of 75% or more based on the syndiotactic triad standard (rr%) may radically polymerize methyl methacrylate in the presence of a solvent having a specific solubility parameter capable of gel formation. PMMA rich in syndiotacticity can be obtained by this method (see Patent Document 7), but this method has not been reported on stereocontrol of acrylonitrile, and stereocontrol of PAN using stereoregular PMMA is possible. Even if it is, it is necessary to separate and collect the obtained PAN and stereoregular PMMA as a template, and practicality cannot be expected from an industrial point of view. Thus, stereoregular polymer polymerization using a template polymer has not been put to practical use until now because the combination of monomers that can be generally applied and the stereoregularity of the resulting polymer are insufficient.

JP-A-1-203406 JP-A-3-68606 JP-A-7-18012 JP-A-6-287398 Japanese Patent Laid-Open No. 7-242705 JP-A-8-301937 JP 2001-89528 A “Journal of the American Chemical Society” (USA), 1960, Vol. 82, No. 21, p. 5671-5678 “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 European Polymer Journal, vol. 22, 1986, 559 “(Polymer International) Polymer International”, 1994, Vol. 35, No. 3, p. 249-255 “Polymer Preprints Japan”, 1998, 47, 7, p. 1291 “Journal of Polymer Science: Polymer Chemistry Edition”, USA, 1973, 11, 5, p. 989 “Journal of Polymer Science: Polymer Chemistry Edition”, USA, 1973, 11, 5, p. 1003 “Journal of Polymer Science; Polymer Chemistry Edition”, USA, 1985, Vol. 23, No. 3, p. 813

  The object of the present invention is to provide general polymerization equipment and conditions (temperature, polymerization initiator) in radical polymerization and anionic polymerization suitable for polymerization of acrylonitrile, which is a polar vinyl monomer, in response to the problem of stereoregular polyacrylonitrile production technology. Development of template polymerization method using stereoregular polymer for obtaining applicable and simple stereoregular polymer composition, and stereoregular polymer composition which is economically and industrially advantageous, and production method thereof Is to provide.

  As a result of intensive studies in view of the above-described conventional techniques, the present inventors have conducted research on a high molecular weight stereoregular polyacrylonitrile-based polymer that is excellent in isotacticity by means of template polymerization, and the production thereof. In particular, by polymerizing an unsaturated copolymerization component mainly composed of acrylonitrile or acrylonitrile in the presence of a polymer containing polyacrylonitrile chain units having an isotacticity of 50% or more based on isotactic triad (mm%). Polyacrylonitrile-based polymerization in which stereospecific polymerization of acrylonitrile monomer is manifested by the steric effect of the template polymer, and the resulting polymerization composition has an isotacticity of 35% or more based on isotactic triad (mm%) Find a composition and book This has led to the achievement of a light.

That is, the object of the present invention is to
A stereoregular polyacrylonitrile composed of an unsaturated copolymerization component mainly composed of acrylonitrile or acrylonitrile,
It has an isotacticity of 35% or more on the basis of isotactic triad (mm%), and the isotactic triad content accounts for 40 mol% or more of the repeating units of all polyacrylonitrile, This can be achieved by a stereoregular polyacrylonitrile-based polymerization composition.

Furthermore, the object of the present invention is to
The unsaturated copolymer component acrylonitrile or acrylonitrile account for at least 75 mol%, isotactic triads (mm%) of a polymer comprising polyacrylonitrile chain units of more than 50% by reference, polyacrylonitrile heavy finally obtained Polymerized in the presence of 5 to 50% by weight on the basis of the coalescence composition, has an isotacticity of 35% or more on the basis of isotactic triad (mm%), and has an isotactic triad content Is achieved by a method for producing a stereoregular polyacrylonitrile-based polymer composition that obtains a polyacrylonitrile-based polymer composition that accounts for 40 mol% or more of the repeating units of all polyacrylonitrile.

  According to the present invention, general radical equipment and conditions (temperature, polymerization initiator) can be applied in radical polymerization and anionic polymerization suitable for polymerization of acrylonitrile, which is a polar vinyl monomer, and a simple stereoregular polymer composition. Development of a template polymerization method using a stereoregular polymer for obtaining a product, and a stereoregular polymer composition that is economically and industrially advantageous and a method for producing the same are provided.

Hereinafter, the present invention will be described in detail.
The monomer for polymerization that is a raw material of the polymerization composition of the present invention is acrylonitrile and a copolymer with an unsaturated copolymer component mainly composed of acrylonitrile.
Here, “mainly” means that the component occupies 50 mol% or more, preferably 75 mol% or more, particularly 95 mol% or more based on all components.

  As the unsaturated copolymerization component to be a copolymerization partner of acrylonitrile, conventionally known ones can be used. However, unsaturated carboxylic acid and / or unsaturated carboxylic acid ester having high radical polymerization activity and / or anionic polymerization activity, Particular preference is given to using amide derivatives, in particular acrylic acid, methacrylic acid, itaconic acid and / or their alkyl esters, alkyl amides. 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.

  Other copolymer components include anionic polymerization active polar vinyl monomers such as methacrylonitrile, vinyl acetate, acrylamide, maleic anhydride, N-vinylpyrrolidone, aromatic vinyl compounds such as styrene, vinyl pyridine and vinyl imidazole, etc. Can also be preferably used. These copolymerization components may be used alone or in combination, and polar vinyl such as acrylic acid, methacrylic acid, itaconic acid, or alkyl esters thereof, methacrylonitrile, vinyl acetate, acrylamide, maleic anhydride, and N-vinylpyrrolidone. At least one compound selected from the group consisting of monomers, aromatic vinyl compounds such as styrene, vinyl pyridine and vinyl imidazole can be particularly preferably selected.

  The addition amount of these copolymerizable monomer components is 0 to 50 mol%, preferably 0 to 30 mol%, particularly preferably 0 to 20 mol%. 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 resulting polymer is not only used as a material for fibers, films, and other various molded products, but it can be blended and compounded according to the type and structure of the copolymerization component to improve and functionalize other materials. It can also be used as a prepolymer and subsequently applied to components copolymerized with various monomers.

  In the polymerization composition of the present invention, the isotactic triad content needs to occupy 40 mol% or more of the repeating units of all polyacrylonitrile. Here, if it is less than 40 mol%, the contribution of fine structure to physical and chemical properties such as excellent mechanical properties, heat resistance, solvent resistance, and chemical resistance of polyacrylonitrile, which is a stereoregular polar polymer, may occur. There are few, and the effect to the physical-property improvement expected is few or it is not connected. The higher the content of isotactic triad, the better, and preferably 45 mol% or more.

  In the production method of the present invention, the monomer for polymerization is polymerized in the presence of a polymer containing a polyacrylonitrile chain unit having an isotacticity of 50% or more based on isotactic triad (mm%). And

  Such an isotactic polyacrylonitrile-based polymer may be a homopolymer consisting only of acrylonitrile units or a copolymer containing 0 to 50 mol% of other unsaturated copolymerization components. The tacticity of the acrylonitrile chain in the polymer is preferably in the form of triplets and the meso-meso (mm) chain is preferably 50% or more, more preferably 60% or more. The number average molecular weight of the polymer is not particularly limited, but is preferably 100 or more.

  As the unsaturated copolymerization component to be a copolymerization partner of acrylonitrile, conventionally known ones can be used. However, unsaturated carboxylic acid and / or unsaturated carboxylic acid ester having high radical polymerization activity and / or anionic polymerization activity, Particular preference is given to using amide derivatives, in particular acrylic acid, methacrylic acid, itaconic acid and / or their alkyl esters, alkyl amides. 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.

Other copolymerization components include methacrylonitrile, vinyl acetate, acrylamide, maleic anhydride, anionic polymerization-active polar vinyl monomers such as N-vinylpyrrolidone, aromatic vinyl compounds such as styrene, vinylpyridine, and vinylimidazole. Can also be preferably used. A method for producing such stereoregular acrylonitrile-based polymer for a template is not particularly limited as long as it is a method capable of expressing isotacticity, but as an effective method, for example, reported in Non-Patent Document 1 described above. A solid phase photopolymerization method at a low temperature (−78 ° C.) using the prepared urea / monomer inclusion complex, an anionic polymerization method using organomagnesium or the like as an initiator (Non-patent Document 6), or magnesium chloride or the like. The radical polymerization method used in the molecular template and carrier (Non-Patent Document 4 mentioned above) can be used. The composition of the obtained polymer, and tacticity of the polyacrylonitrile main chain may be quantified identified by ¹ H-NMR and ¹³ C-NMR.

  In the present invention, the isotactic polyacrylonitrile-based polymer acts as a stereoregular template polymer, and the polymerization monomer and the polymerization composition are obtained by polymerizing the polymer in the presence of 50% by weight or more of the monomer. Accordingly, the content of the template polymer in the obtained composition is 5% by weight or more.

  The content of the template polymer in the polymerization composition is preferably 5% by weight or more, more preferably 20% by weight or more based on the finally obtained polyacrylonitrile-based polymer composition, and 50% by weight. Although it is particularly preferred that the amount exceeds 50% by weight, there is a problem that the amount of the template polymer to be prepared becomes too large.

  In the polymerization using the stereoregular template polymer of the present invention, an appropriate solvent can be used. Specifically, it may be a polar solvent in which the polymer and the monomer are dissolved, but it must be in a solvent form in which the initiator is not deactivated particularly in anionic polymerization. Preferred examples of such a solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidinone, dimethyl sulfoxide and the like.

  In addition, in the radical polymerization system, in addition to these solvents, for example, an aqueous solvent in which the stereoregular PAN polymer as a template dissolves like a concentrated aqueous solution of zinc chloride can be preferably used. In particular, in the case of radical polymerization in the case of radical polymerization, the polymer obtained is relatively easy to obtain a high molecular weight because there is little chain transfer to the solvent, but in particular, the viscosity average molecular weight with good mechanical properties (hereinafter sometimes simply referred to as Mv) Can obtain a high molecular weight polyacrylonitrile-based polymer having a molecular weight of 100,000 or more.

  The radical polymerization initiator and the anionic polymerization initiator in the present invention may be those used in ordinary radical polymerization and anionic polymerization. As such an initiator, examples of radical polymerization initiators include AIBN (azobisisobutyronitrile), azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2, 2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), dimethyl-2,2-azobis (2-methylpropionate), 1,1- (cyclohexane-1-carbonitrile), 2,2 -Azo compounds represented by azobis (2-methylbutyronitrile), 2,2-azobis [N- (2-propenyl) -2-methylpropionamide] and the like, organic peroxides such as benzoyl peroxide and / or Or redox by combination of peroxide and reducing agent such as potassium peroxysulfate / sodium sulfite and N, N-dimethylaniline / benzoyl peroxide Radical polymerization proceeds by redox reactions such as initiators, manganese acetylacetonate (III), cobalt acetylacetonate (II), and pentacyanobenzylcobaltate, iron (II) sulfate / hydrogen peroxide (Fenton reagent) Transition metal compounds and organoboron compounds / oxygen systems that can be prepared. In addition, radiation such as γ-rays and X-rays, electron beams, ultraviolet rays, monochromatic visible rays, natural light, and even heating can be used suitably for the polymerization initiation reaction because radicals can be generated from the monomer. I can do it. These can be preferably carried out alone or in combination with an initiator such as a combination of an azo initiator and heat and light irradiation.

  Regarding the polymerization temperature, it is desirable that the polymerization be carried out at a relatively low temperature, preferably 150 ° C., more preferably 100 ° C., and even more preferably 80 ° C. or less so as not to cause decomposition into monomers and side reactions during polymerization. It is.

  On the other hand, as an anionic polymerization initiator, 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, etc., 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, a sufficiently high molecular weight polymerization composition cannot be obtained due to side reactions other than the polymerization reaction, polymer decomposition, and the like.

  Although the steric control mechanism in the polymerization process in the present invention has not been fully elucidated, it is presumed that the template polymerization is performed under the condition that the stereoregular polyacrylonitrile chain as the template exists in the vicinity of the acrylonitrile as the monomer. By doing so, stereospecific addition during monomer polymerization is induced by the steric effect of the polymer, and as a result, a polymer composition rich in isotacticity is expected to be obtained.

  Regarding the microstructure of the polyacrylonitrile-based polymer polymerization composition 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 stereoregular polyacrylonitrile chain unit that is present in 35% or more in all microstructures including syndiotactic triad (rr) and mr (heterotactic triad) aligned in a meso-racemo configuration.

The term “mm” and / or “rr” as used herein means three-dimensional structures of mm, mr, and rr in the ¹³ C-NMR spectrum of α-carbon in the case of an α-mono-substituted polar vinyl polymer such as polyacrylonitrile. It can be calculated from the peak intensity ratio based on.

  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 35%, the fine structure contributes little to the above-mentioned physical and chemical properties, and the expected effect on the functional expression is small or not linked.

Hereinafter, although a reference example and an example explain the present invention still more concretely, the present invention does not receive any limitation by this.
In the examples, the composition of the polymer is ¹ H-NMR, and the stereoregularity (tacticity) is ¹³ C-NMR measurement (270 MHz JNR-EX-270, manufactured by JEOL Datum Co., Ltd., solvent DMSO-d6). The isotactic triad (mm), the syndiotactic triad (rr), and the heterotactic triad (mr) were determined.

The viscosity average molecular weight (Mv) of the polymer is empirical formula (1) using ηsp / C measured in N, N′-dimethylformamide at 35 ° C. using an S-40 standard Ubbelohde viscometer.
[Equation 1]
[Η] = 0.6712 × ηsp / C + 0.063 (1)
Using the intrinsic viscosity [η] calculated by substituting for, the following formula (2) was used.
[Equation 2]
^{[Η] = 3.17 × 10 -4} × Mv 0.746 (2)

[Reference Example 1] Polymerization of template polymer (polyacrylonitrile):
In a dry nitrogen stream, 9.5 parts by weight of anhydrous magnesium chloride is placed in a 30 ml two-neck pear-type flask, kept at 5 to 10 ° C., and 5.30 parts by weight of acrylonitrile (1 mole equivalent to magnesium chloride) as an initiator. A solution prepared by dissolving 0.033 parts by weight of azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) was added dropwise and stirred for 24 hours to prepare a powdery complex composed of acrylonitrile / magnesium chloride. Polymerization was carried out by maintaining this in a thermostat kept at 60 ° C. for 24 hours.

  After the polymerization, the complex is poured into methanol, and the produced white precipitate is filtered off, washed with 1N hydrochloric acid aqueous solution, deionized water, and then with acetone in order and vacuum dried overnight to obtain 3.75 parts by weight of the produced polymer. It was.

100 mg of the produced polymer was dissolved by heating in 1 ml of deuterated dimethyl sulfoxide, and triad tacticity was determined from ¹³ C-NMR measurement at 50 ° C., and (mm / mr / rr) = (55.0 / 32. 9 / 12.1) and was confirmed to have high isotacticity. The viscosity average molecular weight Mv calculated based on ηsp / C measured in N, N′-dimethylformamide at 35 ° C. was 109965.

[Reference Example 2] Polymerization of template polymer (polyacrylonitrile):
In Reference Example 1, 2.21 g of a produced polymer was obtained by performing polymerization and treatment under the same conditions except that magnesium chloride was changed to 12.9 parts by weight of cobalt chloride.

100 mg of the polymer was dissolved in 1 ml of deuterated dimethyl sulfoxide with heating, and triad tacticity was quantified from ¹³ C-NMR measurement at 50 ° C. As a result, (mm / mr / rr) = (88.5 / 9.5 / 2. 0), which was confirmed to have extremely high isotacticity. The viscosity average molecular weight Mv calculated on the basis of ηsp / C measured in N, N′-dimethylformamide at 35 ° C. was 89,173.

[Reference Example 3] Polymerization of template polymer (polyacrylonitrile copolymer):
Under a dry nitrogen stream, 9.5 parts by weight of anhydrous magnesium chloride was placed in a 30 ml two-neck pear-shaped flask, kept at 5 to 10 ° C., 5.30 parts by weight of acrylonitrile (1 mole equivalent to magnesium chloride), methyl acrylate, 0. 66 parts by weight, 0.4 parts by weight of dibutyl itaconate and 0.033 parts by weight of azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as an initiator were added dropwise and stirred for 24 hours. A powdery complex was prepared. Polymerization was carried out by maintaining this in a thermostat kept at 60 ° C. for 24 hours. After the polymerization, the complex was poured into methanol, and the produced white precipitate was filtered off, washed thoroughly in the order of 1N hydrochloric acid aqueous solution, deionized water and acetone, and dried in vacuum overnight to obtain 3.93 parts by weight of the produced polymer. . ^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.

The polymer 100mg were dissolved by heating in deuterated dimethyl sulfoxide 1 ml, performed ¹³ C-NMR measurement at 50 ° C., was quantified tacticity, (mm / mr / rr) = (67.5 / 26.3 / 6.2), which was confirmed to have high isotacticity. The viscosity average molecular weight Mv obtained from [η] calculated based on ηsp / C measured in N, N′-dimethylformamide at 35 ° C. was 119315.

[Example 1]
A highly isotactic PAN dope solution was prepared by dissolving 1.06 parts by weight of the high isotactic PAN obtained by the operation of Reference Example 1 as a template polymer in 9 parts by weight of a 64% by weight zinc chloride aqueous solution at room temperature. . To this, 1.06 parts by weight of acrylonitrile monomer was added and stirred to obtain a uniform solution.

  Subsequently, 2,2'-azobis (4-methoxyvaleronitrile) was added as a radical polymerization initiator so as to be 0.25 mol% with respect to the acrylonitrile monomer, and the mixture was stirred and polymerized at room temperature for 6 hours. After completion of the polymerization, the dope solution was poured into 100 ml of pure water, and the precipitated polymer was collected and washed once each with methanol and acetone. The polymer after washing was filtered and dried under reduced pressure at 50 ° C. to obtain 2.1 parts by weight of a polymer composition. When 100 mg of the polymer was dissolved in 1 ml of deuterated dimethyl sulfoxide with heating, and triad tacticity was determined from 13C-NMR measurement at 50 ° C., (mm / mr / rr) = (43.3 / 40.3 / 16.4). ) And was confirmed to have high isotacticity. The viscosity average molecular weight Mv calculated based on ηsp / C measured in N, N′-dimethylformamide at 35 ° C. was 839100.

[Example 2]
In Example 1, 2.05 parts by weight of a polyacrylonitrile polymerization composition was obtained in the same manner except that 1.06 parts by weight of highly isotactic PAN obtained by the operation of Reference Example 2 was used as a template polymer.

^{When 13} C-NMR measurement was performed and tacticity was quantified, (mm / mr / rr) = (60.1 / 27.9 / 12.0), which was confirmed to have high isotacticity. . The viscosity average molecular weight Mv calculated on the basis of ηsp / C measured in N, N′-dimethylformamide at 35 ° C. was 931100.

[Example 3]
A dope solution of high isotactic PAN was prepared by dissolving 1.06 parts by weight of high isotactic PAN obtained by the operation of Reference Example 1 as a template polymer in 9 parts by weight of dehydrated dimethylacetamide at room temperature. To this, 1.06 parts by weight of acrylonitrile monomer was added and stirred to obtain a uniform solution.

  The solution was cooled to −50 ° C. under a dry nitrogen stream, potassium t-butoxide was added as an anionic polymerization initiator so as to be 0.25 mol% based on acrylonitrile, and anionic polymerization was performed at −50 ° C. for 24 hours. . After completion of the polymerization, 1 ml of a 1% by weight hydrochloric acid / water-methanol solution was added to the reaction system, stirred for 30 minutes, the dope solution was poured into 100 ml of pure water, and the precipitated polymer was collected and washed once each with methanol and acetone. Went. The polymer after washing was filtered and dried under reduced pressure at 50 ° C. to obtain 1.9 parts by weight of a polymer composition.

When 100 mg of the polymer was dissolved by heating in 1 ml of deuterated dimethyl sulfoxide and triad tacticity was determined from ¹³ C-NMR measurement at 50 ° C., (mm / mr / rr) = (47.2 / 37.4 / 15. 4), which was confirmed to have high isotacticity. The viscosity average molecular weight Mv calculated based on ηsp / C measured in N, N′-dimethylformamide at 35 ° C. was 81815.

[Example 4]
As a template polymer, 1.06 parts by weight of the highly isotactic PAN copolymer obtained by the operation of Reference Example 3 above was dissolved in 9 parts by weight of a 64% by weight zinc chloride aqueous solution at room temperature to obtain a highly isotactic PAN copolymer. A polymer dope solution was prepared. To this, 1.06 parts by weight of acrylonitrile (1 molar equivalent to magnesium chloride) 0.132 parts by weight of methyl acrylate and 0.08 parts by weight of dibutyl itaconate were added and stirred to obtain a homogeneous solution. 2,2′-Azobis (4-methoxyvaleronitrile) was added as a radical polymerization initiator so as to be 0.25 mol% based on the acrylonitrile monomer, and the mixture was stirred and polymerized at room temperature for 6 hours.

  After completion of the polymerization, the dope solution was poured into 100 ml of pure water, and the precipitated polymer was collected and washed once each with methanol and acetone. The polymer after washing was filtered and dried under reduced pressure at 50 ° C. to obtain 2.2 parts by weight of a polymer composition.

¹ was estimated composition of H-NMR copolymerization composition by measuring, acrylonitrile component, methyl acrylate component, 94.6% dibutyl itaconate component, respectively, 2.4%, was 3.0%. When 100 mg of the polymer was dissolved in 1 ml of deuterated dimethyl sulfoxide with heating, and triad tacticity was determined from ¹³ C-NMR measurement at 50 ° C., (mm / mr / rr) = (48.9 / 36.5 / 14. 6), which was confirmed to have high isotacticity. The viscosity average molecular weight Mv calculated based on ηsp / C measured in N, N′-dimethylformamide at 35 ° C. was 1,257712.

[Comparative Example 1]
Polymerization was carried out under the same conditions as in Example 1 except that the template was not used. ¹³ was quantified triad tacticity by C-NMR measurement, (mm / mr / rr) a = (28.0 / 47.0 / 25.0), substantially atactic polyacrylonitrile 1.0 part by weight It was confirmed that it was only obtained. The viscosity average molecular weight Mv calculated based on ηsp / C obtained using an Ubbelohde viscometer in N, N′-dimethylformamide at 35 ° C. was 532510.

[Comparative Example 2]
Polymerization was carried out under the same conditions as in Example 3 except that the template was not used. ^When triad tacticity was quantified by ¹³ C-NMR measurement, it was (mm / mr / rr) = (25.4 / 49.8 / 24.8), and 0.85 parts by weight of substantially atactic polyacrylonitrile. Only confirmed that it was obtained. The viscosity average molecular weight Mv calculated on the basis of ηsp / C obtained by using an Ubbelohde viscometer in N, N′-dimethylformamide at 35 ° C. was 75245.

Claims (3)

The unsaturated copolymer component acrylonitrile or acrylonitrile account for at least 75 mol%, isotactic triads (mm%) of a polymer comprising polyacrylonitrile chain units of more than 50% by reference, polyacrylonitrile heavy finally obtained Polymerized in the presence of 5 to 50% by weight on the basis of the coalescence composition, has an isotacticity of 35% or more on the basis of isotactic triad (mm%), and has an isotactic triad content A method for producing a stereoregular polyacrylonitrile-based polymerization composition, wherein a polyacrylonitrile-based polymerization composition occupying 40 mol% or more of the repeating units of all polyacrylonitrile is obtained. The polymerization reaction, a radical polymerization initiator addition, irradiation, electron beam irradiation, initiated by at least one treatment selected from the group consisting of ultraviolet irradiation and heat treatment process according to claim 1 polymer composition. The polymerization reaction is carried out by adding an anionic polymerization initiator, the manufacturing method according to claim 1 polymer composition.