JPH10265517A - Stereo complex polymer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition by mixing isotactic polymethyl methacrylate with syndiotactic polymethyl methacrylate having a high stereoregularity, a high molecular weight and a narrow molecular weight distribution by polymerizing methyl methacrylate monomer by using a specific polymerization initiator. SOLUTION: The objective composition is obtained by mixing both (A) isotactic polymethyl methacrylate obtained by polymerizing methyl methacrylate monomer by using a polymerization initiator of the formula [M is a rare earth metal; R is a (substituted) alkyl, an aryl, a cycloalkyl or an arylalkyl; (n) is 2 or 3] in a nonpolar solvent (e.g. toluene), and having 90-100% isotacticity, 100,000-2,000,000 number average molecular weight, 1.0-1.3 ratio of weight average molecular weight/number average molecular weight, and (B) syndiotactic polymethyl methacrylate obtained by polymerizing the methyl methacrylate monomer in a polar solvent (e.g. tetrahydrofuran) and having 90-100% syndiotacticity, 100,000-2,000,000 number-average molecular weight, 1.0-1.3 ratio of weight-average molecular weight/number-average molecular weight.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polymerization initiator and a polymerization method capable of producing isotactic poly (methyl methacrylate) having a high stereoregularity, a high molecular weight and a narrow molecular weight distribution. The present invention relates to a stereocomplex polymer composition comprising isotactic polymethyl methacrylate and syndiotactic polymethacrylate obtained by the method described above. The stereocomplex polymer composition is characterized by a higher-order structure formed by intermolecular forces, and is a double-helical structure in which an isotactic polymethyl methacrylate chain is surrounded by a syndiotactic polymethacrylate ester chain. It is used as a filler for separation or filtration, a gel material and the like.

[0002]

2. Description of the Related Art Polymethacrylates, especially polymethyl methacrylate, have high transparency and are used as molded articles having excellent transparency in a wide range of fields. Also, a crystalline stereocomplex polymer composition obtained by mixing isotactic polymethyl methacrylate and syndiotactic polymethacrylate under appropriate conditions is isotactic polymethyl methacrylate or syndiotactic. It is known that the polymer exhibits different physical properties from the homopolymer of polymethacrylic acid ester, for example, has improved water permeability and solvent resistance, and is flexible and tough.

Hitherto, various studies have been made on stereocomplex polymer compositions and isotactic polymethyl methacrylate and syndiotactic polymethacrylate constituting the same. For example,
Macromolecules, 22 , 3337 (1989), Polymer, 20, 59
(1979) and JP-A-3-244651 disclose a stereocomplex polymer composition and syndiotactic polymethacrylate and isotactic polymethyl methacrylate constituting the stereocomplex polymer composition. However, in the stereocomplex polymer composition obtained by these conventional techniques, at least one of the syndiotactic polymer and the isotactic polymer constituting the composition has three conditions of high stereoregularity, high molecular weight, and narrow molecular weight. Since it was not satisfied, there were problems such as a low melting point.

Also, Macromolecules, 22 , 3337 (1989)
Discloses an isotactic polymethyl methacrylate that satisfies all the above three requirements, but separates the required isotactic polymethyl methacrylate from the obtained isotactic polymethyl methacrylate. A method for producing isotactic poly (methyl methacrylate), which is obtained and has simplified steps that do not require a separation step and the like, and has high stereoregularity, high molecular weight, and narrow molecular weight distribution. Was required.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to a polymerization initiator capable of producing an isotactic polymethacrylate ester which simultaneously satisfies the properties of high stereoregularity, high molecular weight and narrow molecular weight distribution. The present invention also provides a stereocomplex polymer composition comprising an isotactic polymethyl methacrylate and a syndiotactic polymethacrylate obtained by the present invention, and a polymerization method using the same.

[0006]

In the present invention, the polymethacrylic acid ester forming the stereocomplex polymer composition has a higher molecular weight than the conventionally obtained polymethacrylic acid ester forming the stereocomplex polymer composition. In addition, it has the characteristics of excellent stereoregularity and narrow molecular weight distribution. The monodisperse polymethyl methacrylate having a high isotacticity and a high molecular weight according to the present invention is obtained by polymerizing an organic rare earth compound represented by the following general formula [1] as a polymerization initiator using a non-polar solvent. It is characterized by the following.

M [C (SiR ₃ ) ₃ ] _n ··· [1] (wherein M is a rare earth element. R is a hydrogen atom or an alkyl group, an aryl group which may have a substituent, It is at least one group selected from the group consisting of a cycloalkyl group and an arylalkyl group, and n is 2 or 3.) The high-molecular-weight monodisperse polymethacrylate having a high syndiotacticity according to the present invention. Is characterized by being obtained by polymerizing by a known method using a known organic rare earth compound as an initiator. Alternatively, it is characterized by being obtained by polymerization using a polar solvent with an organic rare earth compound represented by the following general formula [1] as an initiator.

M [C (SiR ₃ ) ₃ ] _n [1] (wherein M is a rare earth element. R is a hydrogen atom or an alkyl group, an aryl group which may have a substituent, It is at least one group selected from the group consisting of a cycloalkyl group and an arylalkyl group, and n is 2 or 3. Here, isotacticity and syndiotacticity that indicate the stereoregularity of the polymer are Each is determined by a mesotriad (meso triad [mm]) and a racemic triad (racemic triad [rr]).

A stereocomplex polymer composition according to the present invention is formed, having a high molecular weight and excellent isotacticity and syndiotacticity.
The method for synthesizing polymethacrylic acid ester having the characteristic of narrow molecular weight distribution and the characteristic thereof will be specifically described. The isotactic polymethyl methacrylate used in the present invention has Mn of 100,000 or more and 2,000,000 or less,
And the isotacticity is [mm] 90% or more 1
100% or less, and the ratio of weight average molecular weight / number average molecular weight is 1.0 or more and 1.3 or less. The syndiotactic polymethacrylate used in the present invention has Mn of 100,000 or more and 2,000,000 or less, and has a syndiotacticity of [rr] of 90%.
And a weight average molecular weight / number average molecular weight of 1.0 or more and 1.3 or less.

A stereocomplex polymer composition comprising isotactic polymethyl methacrylate and syndiotactic methacrylate ester having these properties is a novel stereocomplex polymer composition which has never been known before. The polymethacrylate used in the present invention is obtained by polymerizing a methacrylate monomer with a specific organic rare earth compound as a polymerization initiator together with isotactic polymethyl methacrylate and syndiotactic polymethacrylate. .

A polymerization initiator for polymerizing isotactic poly (methyl methacrylate) is an organic rare earth compound represented by the following general formula [1]. During _{M [C (SiR 3) 3} ] n ··· [1] formula, M is a rare earth element selected Sc, Y, lanthanides. Specific examples of the rare earth element include Sc, Y, and L.
a, Ce, Pr, Nd, Pm, Sm, Eu, Gd, T
b, Dy, Ho, Er, Tm, Yb, Lu, among which Y, La, Nd, Sm, Eu, Tm, E
r, Yb, Lu are preferable, and Y, La, Sm, Eu, Y
b and Lu are particularly preferred.

R is a hydrogen atom or a hydrocarbon group,
An optionally substituted methyl group, ethyl group, n-propyl group, isopropyl group, t-butyl group, etc.
To 20 alkyl groups, cycloalkyl groups having 5 to 20 carbon atoms having various structural isomer groups such as cyclopentyl group and cyclohexyl group, and aryl groups having 6 to 20 carbon atoms such as phenyl group, tolyl group and p-methoxyphenyl group. And at least one group selected from an arylalkyl group having 7 to 20 carbon atoms such as a benzyl group and a neophyl group, and an alkenyl group having 2 to 20 carbon atoms. R may be the same or a different combination. n is 2 or 3.

Specific examples of the transition metal compound represented by the general formula [1] include the following compounds. However, it is not limited by these examples. Sc ｛C [Si (CH ₃ ) ₃ ] ₃ ｝ ₂ , Y ｛C
[Si (CH ₃ ) ₃ ] ₃ ｝ ₂ , La ｛C [Si (C
H ₃ ) ₃ ] ₃ } ₂ , Ce ｛C [Si (CH ₃ ) ₃ ] ₃ }
₂ , Pr ｛C [Si (CH ₃ ) ₃ ] ₃ ｝ ₂ , Nd ｛C
[Si (CH ₃ ) ₃ ] ₃ ｝ ₂ , Pm ｛C [Si (C
H ₃ ) ₃ ] ₃ } ₂ , Eu {C [Si (CH ₃ ) ₃ ] ₃ }
_{2, Gd {C [Si (} CH 3) 3] 3} 2, Tb {C
[Si (CH ₃ ) ₃ ] ₃ ｝ ₂ , Dy ｛C [Si (C
H ₃ ) ₃ ] ₃ } ₂ , Ho {C [Si (CH ₃ ) ₃ ] ₃ }
₂ , Er ｛C [Si (CH ₃ ) ₃ ] ₃ ｝ ₂ , Tm ｛C
[Si (CH ₃ ) ₃ ] ₃ ｝ ₂ , Yb ｛C [Si (C
H ₃ ) ₃ ] ₃ } ₂ , Lu {C [Si (CH ₃ ) ₃ ] ₃ }
₂ , Yb ｛C [Si (CH ₂ CH ₂ CH ₂ CH ₃ ) ₃ ]
₃ ｝ ₂ , Yb ｛C [SiH (CH ₃ ) ₂ ] ₃ ｝ ₂ , Yb
{C [SiH ₂ (CH ₃ ) ₂ ] ₃ } ₂ , Yb ｛C [Si
(CH ₃ ) ₂ (C ₆ H ₅ )] ₃ ｝ ₂ , Yb ｛C [Si
(CH ₃ ) (C ₆ H ₅ ) ₂ ] ₃ ｝ ₂ , Yb ｛C [Si
(C ₆ H ₅ ) ₃ ] ₃ ｝ ₂ , Yb ｛C [Si (C ₆ H ₁₀ )
₃ ] ₃ ｝ ₂ , Yb ｛C [Si (CH ₂ C
₆ H ₅ ) ₃ ] ₃ } ₂ , Yb ｛C [Si (CHCHC
H ₃ ) ₃ ] ₃ ｝ ₂ etc.

An example of a method for producing the above organic rare earth compound will be described. A compound represented by the following general formula [2], and MX _n ... [2] (wherein, M and n are the same as those in the general formula [1]. X is fluorine, chlorine, bromine, iodine. And the like.) From the compound represented by the following general formula [3], ZC (SiR ₃ ) ₃ ... [3] (wherein R is the same as that of the general formula [1]) Z is an alkali metal atom selected from lithium, sodium, potassium, etc.) This is a method of producing according to the following reaction formula.

MX _n + n ZC (SiR ₃ ) ₃ → M [C
The reaction conditions in the production of (SiR ₃ ) ₃ ] _n + n ZX vary depending on the composition of the compound to be obtained, but the compound [3] is 1 to 5 times, preferably 2 to 4 times, the mole of the compound [2]. Used in double molar amounts. Further, the reaction temperature is desirably -50 ° C to 100 ° C, preferably -20 ° C to 50 ° C, and the reaction time is desirably 0.1 to 100 hours, preferably 1 to 36 hours. As the solvent used in the reaction, aliphatic hydrocarbons such as hexane and decane, and aromatic hydrocarbons such as benzene and toluene are used. Of these, benzene is preferred. Such a reaction solvent is a compound [2]
Usually 1 to 1000 times, preferably 10 to 5 times
It is used in an amount of 00 times.

According to the above-described production method, a desired organic rare earth compound can be produced with a high yield. The organic rare earth compound thus obtained can be isolated and purified by extracting with an aliphatic hydrocarbon such as hexane and recrystallizing at a low temperature. This production example is disclosed and known, for example, in Journal of American Chemical Society (J. Am. Chem. Soc.), 116, 12071-12072 (1994). Isotactic poly (methyl methacrylate) can be obtained by polymerization using the above organic rare earth compound as a polymerization initiator and a non-polar solvent.
Specific examples of the nonpolar solvent include, for example, aliphatic hydrocarbons such as pentane and hexane, aromatic hydrocarbons such as benzene, toluene, and xylene, preferably aromatic hydrocarbons, and more preferably toluene.

The syndiotactic polymethacrylic acid ester can be obtained by a method in which the above organic rare earth compound is used as a polymerization initiator and polymerization is carried out using a polar solvent instead of a nonpolar solvent. Specific examples of the polar solvent include ethers such as ether and tetrahydrofuran, and nitrogen compounds such as dimethylformamide and triethylamine. The organic rare earth compound is usually used in an amount of 0.0
001 mol% to 20 mol%, preferably 0.0002 to
Used in the range of 10 mol%.

In the present invention, the production of polymethacrylate is carried out by solution polymerization or slurry polymerization. The reaction medium used in the solution polymerization or slurry polymerization includes, for example, aliphatic hydrocarbons such as pentane and hexane, aromatic hydrocarbons such as benzene and toluene, ethers such as diethyl ether and tetrahydrofuran, dimethylformamide, triethylamine and the like. And the like. These reaction media can be used alone or as a mixture of two or more. When the methacrylate monomer as a raw material is liquid under the polymerization conditions, the methacrylate monomer can be used as a reaction medium.

The polymerization temperature is usually in the range of -150 to 50 ° C, preferably -100 to 20 ° C. The molecular weight adjustment at the time of polymerization includes, for example, control of the concentration ratio between a polymethacrylate monomer and an organic rare earth compound,
It can be performed by a known method such as temperature control. Furthermore, the syndiotactic polymethacrylic acid ester can also be obtained by polymerization using a known organic rare earth compound represented by the following general formula [4] as a polymerization initiator by a known method.

[Cp ₂ MRL _{1 l} ] _m ... [4] (where Cp is a cyclopentadienyl group which may have a substituent. M is a rare earth element, and L ₁ is an electron donor. R is a hydrogen atom or a methyl group.
m is 1 or 2, and 1 is an integer of 0 to 2. Examples of the electron donating ligand L ₁ include tetrahydrofuran (THF), diethyl ether (Et ₂ O),
Ethers such as 1,2-dimethoxyethane (DME) are exemplified.

Examples of these polymerization initiators and polymerization using the same are described in, for example, Journal of American Chemical Society (J. Am. Chem. Soc.), 114, 4908-4910 (1.
992), Journal of Synthetic Organic Chemistry, 51, 931-941 (1993), and JP-A-7-258319. Specific examples of the methacrylic acid ester monomer used for the polymerization of the syndiotactic polymethacrylic acid ester in the present invention include methyl methacrylate, isobutyl methacrylate, (m-methyl) benzyl methacrylate, and methacrylic acid (p-methoxy). Examples include benzyl-substituted methacrylic acid-substituted benzyl, methacrylic methacrylate, cyclopropanemethyl methacrylate, and the like. this house,
Preferred are methyl methacrylate, isobutyl methacrylate, and benzyl methacrylate.

By the above method, mesotriad [mm]
Is 90% or more and 100% or less, and the number average molecular weight is 100,000 or more and 2 or more.
Isotactic polymethyl methacrylate having a weight average molecular weight / number average molecular weight of 1.0 to 1.3 and a syndiotacticity determined by racemic triad [rr] of 90% or more 100
% And the number average molecular weight is 100,000 or more 2
It is possible to obtain a syndiotactic polymethacrylate ester having a weight-average molecular weight / number-average molecular weight of 1.0 or more and 1.3 or less.

Next, the synthesis of a stereocomplex polymer composition using the above isotactic polymethyl methacrylate and syndiotactic polymethacrylate as raw materials will be described. The composition ratio of isotactic polymethyl methacrylate and syndiotactic polymethacrylate forming the stereocomplex polymer composition of the present invention is in the range of 99: 1 to 1:99 by weight, preferably 90:10. The range is from 10 to 90. When the composition ratio is out of the above range, a stereocomplex polymer composition is formed, but properties based on the stereocomplex polymer composition are not sufficiently exhibited.

The stereocomplex polymer composition of the present invention can be prepared by mixing a predetermined amount of isotactic polymethyl methacrylate and syndiotactic polymethacrylate under appropriate conditions or by sintering the solution. Is prepared. The solvent used for the solution mixing may be any solvent that can dissolve the isotactic polymethyl methacrylate and the syndiotactic polymethacrylate. Specific examples of the solvent include dimethylformamide, acetone, acetonitrile, carbon tetrachloride, tetrahydrofuran, benzene, toluene, chloroform, dichloromethane, etc. A complex polymer composition is formed, but chloroform and dichloromethane need to be calcined after mixing the solution.

The concentration of the solution at the time of mixing the solution is 0.000
It is in the range of 1% to 10% by weight, preferably 0.0%.
The range is from 01% to 5% by weight. When firing after mixing the solution, the firing temperature is in the range of 80C to 250C,
Preferably it is in the range of 160 ° C to 240 ° C. The firing time is in the range of 1 hour to 60 days, preferably 6 hours.
It ranges from hours to 30 days.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail based on examples and the like. In the production of the organic rare earth compound, a commercial product was used as a raw material. Number average molecular weight (Mn) and molecular weight distribution (Mw / Mn) in Examples
Was measured at 40 ° C. using chloroform as a solvent using an SC8010 gel permeation chromatography (GPC) apparatus manufactured by Tosoh Corporation. The triads ([mm], [rr]) of the polymethacrylic acid ester (such as PMMA) in the examples were manufactured by JEOL Ltd., JNM.
¹ H-NMR using LA400 spectrometer
Was measured and calculated from the integral ratio of the methyl group of the straight-chain branch.
The melting points in the examples are those manufactured by Seiko Electronics Industries, Ltd.
SSC5100 DSC22C Differential Scanning Calorimeter (D
SC).

Example 1 Bis [tris (trimethylsilyl) methyl] ytterbii
Preparation of Yb ｛C [Si (CH ₃ ) ₃ ] ₃ ｝ ₂ YbI ₂ ; 0.62 g of benzene suspension 15 in a 100 ml glass reactor which was sufficiently purged with argon.
30 ml of a benzene solution containing 0.78 g of KC [Si (CH ₃ ) ₃ ] ₃ was added to the mixture, and the mixture was stirred at room temperature for 48 hours. After distilling off the solvent from the reaction solution under reduced pressure, the residue was extracted with hexane and recrystallized at −25 ° C. to obtain orange plate-like Y
0.51 g of b {C [Si (CH ₃ ) ₃ ] ₃ } ₂ was obtained.
(57% yield)

Isotactic polymethyl methacrylate
A polymerization initiator Yb ｛C [Si (CH ₃ ) ₃ ] was placed in a 100 ml glass reactor in which the inside of the process was vacuum degassed and purged with argon.
₃ ｝ ₂ 20μmol and dehydrated and deoxygenated toluene 90m
1 was added. Keep the internal temperature of the glass reactor at -78 ° C,
2.0 g of methyl methacrylate was added. After stirring for 3 hours, the reaction was stopped with excess methanol. After the solvent was distilled off under reduced pressure, the residue was washed with methanol. Further, vacuum drying was performed at 50 ° C. to obtain 2.0 g of a polymer. The obtained polymer had Mn = 163000 and Mw / Mn = 1.1.
4. The isotacticity [mm] was 97.1%.

Syndiotactic polymethacrylate
The polymerization initiator Yb @ C [Si (CH ₃ ) ₃ ] was placed in a 100 ml glass reactor in which the inside of the reactor was vacuum degassed and purged with argon.
10 μmol of ₃ ｝ ₂ and 60 ml of dehydrated and deoxygenated tetrahydrofuran (THF) were added. The internal temperature of the glass reactor was kept at -78 ° C, and 3.0 g of methyl methacrylate was added. After stirring for 3 hours, the reaction was stopped with excess methanol. After the solvent was distilled off under reduced pressure, the residue was washed with methanol. Further, vacuum drying was performed at 50 ° C. to obtain 0.9 g of a polymer. The resulting polymer had Mn = 10300
0, Mw / Mn = 1.25, syndiotacticity [rr] = 90.4%.

The stereocomplex polymer composition
Production 1% by weight of the isotactic polymethyl methacrylate
30 g of an acetone solution and 30 g of a 1% by weight acetone solution of the syndiotactic polymethyl methacrylate were mixed and stirred at room temperature for 2 hours. After centrifugal filtration of the gel,
Vacuum dried at 0 ° C. to obtain 0.4 g of solid. DSC measurement of the obtained solid showed a melting temperature of 201 ° C.

Comparative Example 1 Production of Isotactic Poly (methyl methacrylate ) A polymerization initiator t-BuMgBr was added to a 100 ml glass reactor in which the inside was degassed under vacuum and replaced with argon, and 10 μmo of the polymerization initiator was added.
and 60 ml of dehydrated and deoxygenated toluene were added. The internal temperature of the glass reactor was kept at -78 ° C, and 1.0 g of methyl methacrylate was added. After stirring for 24 hours, the reaction was stopped with excess methanol. After the solvent was distilled off under reduced pressure, the residue was washed with methanol. Further vacuum drying at 50 ℃,
0.4 g of polymer was obtained. The resulting polymer has Mn
= 43000, Mw / Mn = 1.15, isotacticity [mm] = 96.1%.

Syndiotactic polymethacrylate
A polymerization initiator t-BuLi; 10 μmol; and Al (CH ₂ CH ₃ ) ₃ ; 30 μmol, together with 30 ml of dehydrated and deoxygenated toluene, were placed in a 100 ml glass reactor in which the inside of the reactor was vacuum degassed and purged with argon. Keep the internal temperature of the glass reactor at -78 ° C, and add 1.0 g of methyl methacrylate.
added. After stirring for 24 hours, the reaction was stopped with excess methanol. After the solvent was distilled off under reduced pressure, the residue was washed with methanol. Furthermore, vacuum drying was performed at 50 ° C. to obtain 0.3 g of a polymer. The resulting polymer had Mn = 3600
0, Mw / Mn = 1.25, syndiotacticity [rr] = 88.1%.

The stereocomplex polymer composition
Production 1% by weight of the isotactic polymethyl methacrylate
30 g of an acetone solution and 30 g of a 1% by weight acetone solution of the syndiotactic polymethyl methacrylate were mixed and stirred at room temperature for 2 hours. After centrifugal filtration of the gel,
Vacuum dried at 0 ° C. to obtain 0.4 g of solid. DSC measurement of the obtained solid showed a melting temperature of 188 ° C.

Example 2 Preparation of Stereocomplex Polymer Composition 10 g of a 1 wt% THF solution of isotactic polymethyl methacrylate synthesized in Example 1 and syndiotactic polymethyl methacrylate synthesized in Example 1 50 g of a 1% by weight THF solution was mixed and stirred at room temperature for 2 hours.
After the gel was centrifugally filtered, it was vacuum-dried at 50 ° C. to obtain 0.3 g of a solid. DSC measurement of the obtained solid showed a melting temperature of 202 ° C.

Example 3 Preparation of Syndiotactic Polybenzyl Methacrylate A polymerization initiator [(C ₅ Me ₅ ) ₂ SmH] _{2 was} placed in a 100 ml glass reactor whose inside was degassed under vacuum and replaced with argon.
And 90 ml of dehydrated and deoxygenated toluene. The internal temperature of the glass reactor was kept at -78 ° C, and 3.5 g of benzyl methacrylate was added. After stirring for 24 hours, the reaction was stopped with excess methanol. After the solvent was distilled off under reduced pressure, the residue was washed with methanol. Further, vacuum drying was performed at 50 ° C. to obtain 3.3 g of a polymer. The obtained polymer had Mn = 172000 and Mw / Mn = 1.0.
8. Syndiotacticity [rr] = 92.7%.

The stereocomplex polymer composition
20 g of a 3 wt% chloroform solution of isotactic polymethyl methacrylate synthesized in Production Example 1 and 20 g of a 3 wt% chloroform solution of the syndiotactic polybenzyl methacrylate were mixed and stirred at room temperature for 2 hours. The mixed solution was precipitated in hexane and filtered by centrifugation.
Vacuum dried to obtain 1.1 g of a solid. Then 190
The heat treatment was performed at 48 ° C. for 48 hours. DSC measurement of the obtained solid showed a melting temperature of 213 ° C.

Example 4 Preparation of Stereocomplex Polymer Composition 30 g of a 2% by weight dimethylformamide solution of isotactic polymethyl methacrylate synthesized in Example 1 and syndiotactic polybenzyl methacrylate synthesized in Example 3 Was mixed with 15 g of a 1% by weight dimethylformamide solution and stirred at room temperature for 2 hours. After the gel was centrifugally filtered, it was vacuum-dried at 50 ° C. to obtain 0.4 g of a solid.
DSC measurement of the obtained solid showed a melting temperature of 203 ° C.

Example 5 Production of Isotactic Poly (methyl methacrylate ) A polymerization initiator Yb @ C [Si (CH ₃ ) ₃ ] was placed in a 100 ml glass reactor in which the inside was degassed under vacuum and replaced with argon.
₃ ｝ ₂ 10 μmol and dehydrated and deoxygenated toluene 90m
1 was added. Keep the internal temperature of the glass reactor at -78 ° C,
4.0 g of methyl methacrylate was added. After stirring for 6 hours, the reaction was stopped with excess methanol. After the solvent was distilled off under reduced pressure, the residue was washed with methanol. Further, vacuum drying was performed at 50 ° C. to obtain 3.8 g of a polymer. The obtained polymer had Mn = 659000 and Mw / Mn = 1.2.
1. Isotacticity [mm] = 96.8%.

Syndiotactic polymethacrylate
The polymerization initiator [(C ₅ Me ₅ ) ₂ SmH] _{2 was} placed in a 100-ml glass reactor in which the inside of the reactor was vacuum degassed and purged with argon.
And 90 ml of dehydrated and deoxygenated toluene. The internal temperature of the glass reactor was kept at -78 ° C, and 2.0 g of methyl methacrylate was added. After stirring for 24 hours,
The reaction was stopped with excess methanol. After the solvent was distilled off under reduced pressure, the residue was washed with methanol. Further, vacuum drying was performed at 50 ° C. to obtain 1.9 g of a polymer. The obtained polymer had Mn = 306000, Mw / Mn = 1.04, and syndiotacticity [rr] = 93.4%.

The stereocomplex polymer composition
Production 3% by weight of the isotactic polymethyl methacrylate
20 g of a chloroform solution and 20 g of a 3% by weight chloroform solution of the syndiotactic polybenzyl methacrylate
And stirred at room temperature for 2 hours. The mixed solution was precipitated in hexane, centrifugally filtered, and dried in vacuo at 50 ° C. to obtain 1.1 g of a solid. Subsequently, heat treatment was performed at 200 ° C. for 3 days. DSC measurement of the obtained solid showed a melting temperature of 217 ° C.

Example 6 Preparation of Stereocomplex Polymer Composition 50 g of 0.5% by weight dichloromethane solution of isotactic polymethyl methacrylate synthesized in Example 5 and syndiotactic polymethacrylic acid synthesized in Example 5 50 g of a 1% by weight solution of benzyl in dichloromethane was mixed and stirred at room temperature for 2 hours. The mixed solution was precipitated in hexane, centrifugally filtered, and dried in vacuo at 50 ° C. to obtain 0.7 g of a solid. Subsequently, heat treatment was performed at 230 ° C. for 15 days. The obtained solid was measured by DSC to find that it was 242.
A melting temperature of ° C was indicated.

Example 7 Bis [tris (bismethylphenylsilyl) methyl] yu
Uropium: Eu @ C [Si (CH ₃ ) ₂ (C
₆ H _{5)] 3} 2} in the production well glass reactor having an inner volume of 100ml which was replaced with argon, EuI _2; benzene suspension of 0.65 g 20
ml of KC [Si (CH ₃ ) ₂ (C ₆ H ₅ )] ₃ ;
Add 51 g of benzene solution (40 ml) and add 48 g at room temperature.
Stirred for hours. After evaporating the solvent from the reaction solution under reduced pressure, the residue was extracted with hexane and recrystallized at −25 ° C. to obtain Eu ｛C [Si (CH ₃ ) ₂ (C
₆ H _{5)] 3} 2} was obtained 0.66 g. (Yield 42%)

Isotactic polymethyl methacrylate
A polymerization initiator Eu @ C [Si (CH ₃ ) was placed in a 100 ml glass reactor in which the inside of the process was vacuum degassed and purged with argon.
₂ (C ₆ H ₅ )] ₃ μm ₂ and 60 ml of dehydrated and deoxygenated toluene were added. The internal temperature of the glass reactor was kept at -78 ° C, and 2.0 g of methyl methacrylate was added. After stirring for 6 hours, the reaction was stopped with excess methanol. After the solvent was distilled off under reduced pressure, the residue was washed with methanol.
Further, vacuum drying was performed at 50 ° C. to obtain 1.8 g of a polymer. The obtained polymer had Mn = 322000, M
w / Mn = 1.22, isotacticity [mm]
= 97.2%.

Syndiotactic polymethacrylate
The polymerization initiator (C ₅ Me ₅ ) ₂ Lu (C) was placed in a 100 ml glass reactor in which the inside of the butyl production was degassed under vacuum and replaced with argon.
10 μmol of H ₃ ) (THF) and 90 ml of dehydrated and deoxygenated toluene were added. The internal temperature of the glass reactor was -78.
C., and 1.4 g of isobutyl methacrylate was added.
After stirring for 48 hours, the reaction was stopped with excess methanol. After the solvent was distilled off under reduced pressure, the residue was washed with methanol. Further, vacuum drying was performed at 50 ° C. to obtain 0.8 g of a polymer. The obtained polymer had Mn = 149,000 and Mw
/Mn=1.06, syndiotacticity [rr]
= 92.6%.

The stereocomplex polymer composition
Production 1% by weight of the isotactic polymethyl methacrylate
30 g of a THF solution and 45 g of a 1% by weight THF solution of the syndiotactic polyisobutyl methacrylate were mixed and stirred at room temperature for 3 hours. After centrifugal filtration of the gel,
Vacuum drying at 0 ° C. yielded 0.5 g of a solid. DSC measurement of the obtained solid showed a melting temperature of 207 ° C.

[0046]

According to the method of the present invention, it is possible to obtain an isotactic poly (methyl methacrylate) which simultaneously satisfies the properties of high stereoregularity, high molecular weight and narrow molecular weight distribution without requiring a separation step or the like. Can be. Furthermore, a stereocomplex polymer having a high melting point and comprising a syndiotactic polymethacrylate having a high stereoregularity, a high molecular weight, and a narrow molecular weight distribution with the obtained isotactic polymethacrylate can be obtained.

Continued on the front page (72) Inventor Gen Yasuda 531-401, Iida, Hachihonmatsu-cho, Higashihiroshima City, Hiroshima Prefecture (72) Inventor Eiji Ihara 2-360-3-301 Kagamiyama, Higashihiroshima City, Hiroshima Prefecture

Claims (4)

[Claims] 1. A polymerization initiator used for producing an isotactic polymethyl methacrylate by polymerizing a methyl methacrylate monomer, wherein the polymerization initiator is an isotactic polymethacrylic acid represented by the following general formula [1]: Polymerization initiator for methyl. M [C (SiR ₃ ) ₃ ] _n ··· [1] (wherein, M is a rare earth element. R is a hydrogen atom or an optionally substituted alkyl group, aryl group, cycloalkyl group , An arylalkyl group, and n is 2 or 3.) 2. A method for polymerizing isotactic poly (methyl methacrylate), comprising polymerizing a methyl methacrylate monomer using the polymerization initiator according to claim 1 and a non-polar solvent. 3. The (A) isotacticity determined by the mesotriad [mm] obtained by the polymerization method according to claim 2 is 90% or more and 100% or less, and the number average molecular weight is 100,000 or more and 2,000,000 or less. And an isotactic polymethyl methacrylate having a weight average molecular weight / number average molecular weight of 1.0 or more and 1.3 or less.
% By weight and (B) syndiotacticity determined by racemic triad [rr] is 90% or more and 100% or less, number average molecular weight is 100,000 or more and 2,000,000 or less, and weight average molecular weight / number average molecular weight Is a syndiotactic polymethacrylate having a content of from 1.0 to 1.3, inclusive. 4. The method according to claim 1, wherein the syndiotactic polymethacrylate is obtained by a polymerization method using an organic rare earth compound represented by the following general formula [1] as a polymerization initiator and a polar solvent. The stereocomplex polymer composition according to claim 3, wherein M [C (SiR ₃ ) ₃ ] _n ··· [1] (wherein, M is a rare earth element. R is a hydrogen atom or an optionally substituted alkyl group, aryl group, cycloalkyl group , An arylalkyl group, and n is 2 or 3.)