JPH10287703A - Method for producing vinyl polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a vinyl polymer in good yields at an increased utilization efficiency of a polymerization initiator by adding a hydrogen-atom-dissociating organic compound in the living polymerization of a vinyl monomer in the presence of a polymerization initiator being an organometallic complex. SOLUTION: An organometallic complex (e.g. an organometallic complex of e.g. a group III a metal) is used as a polymerization initiator and used in an amount of 1×10<-4> to 1×10<-1> mol per mol of the vinyl monomer used. A vinyl monomer, desirably a (meth)acrylic acid ester, is polymerized, and a hydroxyl-free compound having a pKa value in the range of 5-20 typified by e.g. acetylacetone is added to the reaction system after the polymerization. The amount of use is desirably 1.0-20 mol per mol of the organometallic complex. In order to heighten the polymerization initiation activity of the vinyl monomer added in the second state, it is also possible to add e.g. a Lewis acid compound (e.g. an organoaluminum compound). After the polymerization reaction reaches the desired degree, the polymerization is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a vinyl polymer by polymerizing a vinyl monomer using an organometallic complex as a polymerization initiator.

[0002]

2. Description of the Related Art As a method for producing a vinyl polymer whose primary structure is precisely controlled, there is a living polymerization method of a vinyl monomer. Generally, the living polymerization method comprises only a polymerization initiation reaction and a growth reaction, and does not cause a termination reaction or a chain transfer reaction. For this reason, in the living polymerization method, it is possible to control the molecular weight of the obtained polymer by a charge ratio of a polymerization initiator and a monomer, and it is also possible to use a living active terminal to perform block copolymerization or the like. There is an advantage that a functional group can be efficiently introduced into the polymer terminal. But,
In the living polymerization method, since only a polymer having the same number of molecules as the polymerization initiator is formed, when an expensive polymerization initiator such as an organometallic complex is used, the cost of the polymerization initiator per number of polymer molecules is high. turn into. This point is a great limitation in industrially adopting the living polymerization method.

When an aluminum porphyrin complex is used as a polymerization initiator and ring-opening polymerization is carried out in the presence of an alcohol using an epoxide, episulfide or a lactone as a monomer, the aluminum porphyrin complex is bonded via an oxygen atom or a sulfur atom. A polymer having a structure bonded to the above aluminum atom at the end is formed, and undergoes a reversible exchange reaction with the coexisting alcohol to form a hydroxyl-terminated or thiol-terminated polymer and ring-opening polymerization. It has been reported that ring-opening polymerization can be apparently initiated from an alcohol because an aluminum alcoholate complex having an initiating ability is formed, and such a polymerization method is called an immortal polymerization method (Macromolecule). (Macromolecul)
es) Volume 21, pages 1195 to 1202 (1988)
Year); Journal of Chemical Society Chemical Communication (J. Chem. Soc.,
Chem. Commun. ) Pp. 1148-1149,
1985). However, the polymerization reaction to which the immortal polymerization method is applied in the above report is a living ring-opening polymerization of a specific cyclic monomer, and a living addition polymerization of a vinyl monomer such as methacrylic acid ester and acrylic acid ester. No immortal polymerization method has been reported.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is not only to obtain a desired vinyl polymer in a good yield in living polymerization of a vinyl monomer, but also to reduce the number of molecules of a polymerization initiator used. An industrially advantageous method for producing a vinyl polymer, which can reduce the amount of the polymerization initiator used by increasing the utilization efficiency of the polymerization initiator in terms of the number of molecules of the produced polymer on a standard basis. It is to provide.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that the first-stage vinyl-based monomer can be produced using an organometallic complex as a polymerization initiator. After the polymerization, a specific organic compound is added to the reaction mixture and reacted to deactivate the living active terminal of the vinyl-based polymer obtained by the first-stage polymerization (ie, At the same time, the polymerization of the first-stage vinyl monomer can be stopped), and at the same time, the organometallic complex dissociates and can exhibit its activity as a polymerization initiator again (strictly speaking, the living activity). It is presumed that a complex is formed from the metal coordinated at the terminal and the added organic compound, which acts as a new polymerization initiation species). Second stage The living polymerization of the phenyl-based monomer can be newly started, whereby the vinyl-based polymer can be obtained with a high yield and the number of molecules of the produced polymer based on the number of molecules of the polymerization initiator used. It has been found that the polymerization initiator can be produced with a higher utilization efficiency from the viewpoint, and the present invention has been completed.

That is, the present invention provides:

(1) A vinyl monomer is polymerized by using an organometallic complex as a polymerization initiator,

(2) The reaction system after polymerization obtained in the above step (1) has a pKa value in the range of 5 to 20,
And adding an organic compound having no hydroxyl group, reacting the organic compound,

(3) A vinyl monomer is added to the reaction system after the reaction obtained in the above step (2), and the vinyl monomer is polymerized.

[0010] A method for producing a vinyl polymer, characterized in that:

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The reaction operation according to the present invention comprises (1)
The first polymerization step of a vinyl monomer using an organic metal complex as a polymerization initiator, (2) Addition and reaction of an organic compound having a pKa value in the range of 5 to 20 and having no hydroxyl group And (3) a series of steps comprising a second polymerization step by addition of a vinyl monomer.

The vinyl monomers which can be used in the first and second stages of polymerization according to the present invention include styrenes such as α-methylstyrene, p-methylstyrene, p-chlorostyrene and styrene; Vinyl esters such as vinyl acetate; methacrylates; acrylates;
Representative examples include conjugated dienes such as isoprene and butadiene; vinyl ethers such as methyl vinyl ether; and α-olefins such as 1-hexene and isobutylene. Of these, methacrylic acid esters and acrylic acid esters are preferably used. You.

The methacrylic acid ester preferably used as a vinyl monomer in the present invention is not limited, but may be, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate. N-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, amyl methacrylate,
Isoamyl methacrylate, n-hexyl methacrylate,
Examples thereof include 2-ethylhexyl methacrylate, pentadecyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, 2-hexyldecyl methacrylate, allyl methacrylate, and vinyl methacrylate. One or more of these can be used. The acrylate ester preferably used as a vinyl monomer in the present invention is not necessarily limited. For example, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, acrylic acid n
-Butyl, isobutyl acrylate, acrylic acid sec-
Butyl, t-butyl acrylate, amyl acrylate, isoamyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, 2-hexyldecyl acrylate, allyl acrylate, vinyl acrylate and the like. , One or more of these can be used.

The organometallic complex used in the first stage polymerization reaction according to the present invention is not particularly limited as long as it acts as a polymerization initiator for the vinyl monomer used. As the organometallic complex, Periodic Table III
A group A metal, a group IVA metal of the periodic table, an organometallic complex of aluminum or zinc, and the like are preferable, and typically represented by the following general formula (I), (II) or (III)

[0015]

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[0016]

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[0017]

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(Wherein R ¹ , R ² , R ³ , R ⁴ ,
R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ each represent a hydrogen atom, a monovalent hydrocarbon group having 1 to 5 carbon atoms or an alkylsilyl group having 1 to 5 carbon atoms, Or two adjacent groups together represent a divalent hydrocarbon group having 1 to 10 carbon atoms; M ¹ is a group IIIA periodic table selected from the group consisting of scandium, yttrium and lanthanoid atoms M ² represents a metal atom, M ² represents a metal atom of Group IVA of the Periodic Table selected from the group consisting of a titanium atom, a zirconium atom and a hafnium atom; A represents a carbon atom which may contain a hydrogen atom or a silicon atom Numbers 1-1
B represents a monovalent hydrocarbon group of 0; B represents an alkylene group having 1 to 3 carbon atoms or an alkylsilylene group having 1 to 3 carbon atoms; D represents a carbon number which may contain a halogen atom or a silicon atom. E represents a solvent molecule; m represents 0 or 1; n represents an integer in the range of 0 to 3; )

An organic transition metal complex represented by the following general formula (IV) or (V)

[0020]

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[0021]

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(Wherein Me represents a methyl group, R ¹¹ and R ¹² each represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R ¹³ represents a hydrogen atom or a substituent. Represents a monovalent hydrocarbon group having 1 to 20 carbon atoms which may be possessed, and R ¹⁴ represents an enolate group, a thiolate group or a monovalent hydrocarbon group having 1 to 10 carbon atoms.)

The metal porphyrin complex represented by the formula:
It should be noted that a scandium atom (S) which is a metal atom of Group IIIA of the periodic table represented by M ¹ in the general formulas (I) and (II)
c), yttrium atom (Y) or lanthanoid atom (La, Ce, Pr, Nd, Pm, Sm, Eu, Gd,
Tb, Dy, Ho, Er, Tm, Yb and Lu) are rare earth metal atoms, of which samarium atom (Sm), europium atom (Eu) and ytterbium atom (Yb) are divalent metal atoms and It belongs to both trivalent metal atoms, and the other metal atoms belong to trivalent metal atoms. M in the general formula (I) and (II), M ¹ is 2
It is 0 when it is a valent metal atom, and it is 1 when M ¹ is a trivalent metal atom.

Representative examples of the organometallic complex represented by the above general formula (I) or (II) include the following compound groups represented by (1) or (2).

(1) Representative examples of organometallic complexes containing divalent rare earth metal atoms: bis (cyclopentadienyl) samarium, bis (pentamethylcyclopentadienyl) samarium, dimethylsilylenebis [2,4-bis (Trimethylsilyl) cyclopentadienyl] samarium, dimethylsilylenebis (2-trimethylsilyl-4-t-butylcyclopentadienyl) samarium, bis (pentamethylcyclopentadienyl) europium, bis (cyclopentadienyl) ytterbium, Bis (pentamethylcyclopentadienyl) ytterbium, dimethylsilylenebis [2,4-bis (trimethylsilyl) cyclopentadienyl] ytterbium, dimethylsilylenebis (2-trimethylsilyl-4-t-butylcyclopentadienyl) i Terbium, etherate or tetrahydrofuranyl sulfonates such of the compound.

(2) Representative examples of organometallic complexes containing a trivalent rare earth metal atom: bis (pentamethylcyclopentadienyl) scandium hydride, bis (pentamethylcyclopentadienyl) scandium methyl, bis (cyclopentadiene) (Enyl) yttrium hydride, bis (cyclopentadienyl) yttrium methyl, bis (cyclopentadienyl) yttrium bis (trimethylsilyl) methyl, bis (pentamethylcyclopentadienyl) yttrium hydride, bis (pentamethylcyclopentadienyl) Yttrium methyl, bis (pentamethylcyclopentadienyl) yttrium bis (trimethylsilyl) methyl, bis (cyclopentadienyl) lanthanum hydride, bis (cyclopentadienyl) lanthanum meth Bis (cyclopentadienyl) lanthanum bis (trimethylsilyl) methyl, bis (pentamethylcyclopentadienyl) lanthanum hydride, bis (pentamethylcyclopentadienyl) lanthanum methyl, bis (pentamethylcyclopentadienyl) lanthanum bis (Trimethylsilyl) methyl, bis (pentamethylcyclopentadienyl) cerium methyl, bis (pentamethylcyclopentadienyl) neodymium methyl, bis (cyclopentadienyl) samarium hydride, bis (cyclopentadienyl) samarium methyl, bis (Cyclopentadienyl) samarium bis (trimethylsilyl) methyl, bis (pentamethylcyclopentadienyl) samarium hydride, bis (pentamethylcyclopentadienyl) samarium Butyl, bis (pentamethylcyclopentadienyl) samarium ethyl, bis (pentamethylcyclopentadienyl) samarium butyl, bis (pentamethylcyclopentadienyl) samarium bis (trimethylsilyl) methyl, bis [1,3-bis ( Trimethylsilyl) cyclopentadienyl] samarium methyl, bis (1,3-di-
t-butylcyclopentadienyl) samarium methyl,
Dimethylsilylenebis [2,4-bis (trimethylsilyl) cyclopentadienyl] samarium methyl, dimethylsilylenebis (2-trimethylsilyl-4-t-butylcyclopentadienyl) samarium methyl, bis (cyclopentadienyl) europium hydride Bis (cyclopentadienyl) europium methyl, bis (cyclopentadienyl) europium bis (trimethylsilyl) methyl, bis (pentamethylcyclopentadienyl) europium hydride, bis (pentamethylcyclopentadienyl) europium methyl, bis (Cyclopentadienyl) ytterbium hydride, bis (cyclopentadienyl) ytterbiummethyl, bis (cyclopentadienyl) ytterbiumbis (trimethylsilyl) methyl Bis (pentamethylcyclopentadienyl) ytterbium hydride, bis (pentamethylcyclopentadienyl) ytterbium methyl, bis (pentamethylcyclopentadienyl) ytterbium bis (trimethylsilyl) methyl, bis [1,3-bis ( Trimethylsilyl) cyclopentadienyl] ytterbiummethyl, bis (1,3-di-t-
Butylcyclopentadienyl) ytterbium methyl,
Dimethylsilylenebis [2,4-bis (trimethylsilyl) cyclopentadienyl] ytterbiummethyl, dimethylsilylenebis (2-trimethylsilyl-4-t-
Butylcyclopentadienyl) ytterbium methyl,
Bis (cyclopentadienyl) lutetium hydride, bis (cyclopentadienyl) lutetium methyl,
Bis (cyclopentadienyl) lutetium bis (trimethylsilyl) methyl, bis (pentamethylcyclopentadienyl) lutetium hydride, bis (pentamethylcyclopentadienyl) lutetium methyl, bis (pentamethylcyclopentadienyl) lutetium bis ( Trimethylsilyl) methyl, bis [1,3-bis (trimethylsilyl) cyclopentadienyl] lutetiummethyl, bis (1,3-di-t-butylcyclopentadienyl) lutetiummethyl, dimethylsilylenebis [2,4
-Bis (trimethylsilyl) cyclopentadienyl] lutetium methyl, dimethylsilylenebis (2-trimethylsilyl-4-t-butylcyclopentadienyl) lutetium methyl, etherate of the above compound or tetrahydrofuranate.

As a typical example of the organometallic complex represented by the general formula (III), there may be mentioned a compound group represented by the following (3).

(3) Representative examples of organometallic complexes containing Group IVA metal atoms: bis (cyclopentadienyl) titanium dichloride, bis (cyclopentadienyl) titanium dimethyl, bis (pentamethylcyclopentadiene) (Enyl) titanium dichloride, bis (pentamethylcyclopentadienyl) titanium dimethyl, bis (cyclopentadienyl) zirconium dichloride, bis (cyclopentadienyl) zirconium dimethyl, bis (pentamethylcyclopentadienyl) zirconium dichloride, bis (Pentamethylcyclopentadienyl) zirconium dimethyl, bis (cyclopentadienyl) hafnium dichloride, bis (cyclopentadienyl) hafnium dimethyl, bis (pentamethylcyclopentadienyl) hafnium Chloride, bis (pentamethylcyclopentadienyl) hafnium dimethyl and the like.

The above general formula (I), (II) or (II)
Among the organometallic complexes represented by I), general formula (I),
In (II) and (III), R ¹ , R ² , R ³ , R ⁴ ,
An organometallic complex in which R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are each a methyl group (ie, an organometallic complex having a pentamethylcyclopentadienyl group as a ligand)
Is preferred.

The above general formula (I), (II) or (II)
The organometallic complexes represented by I) are, for example,
Of the American Chemical Society (J.
Am. Chem. Soc. ) 110, 976 (1988); 107, 8103 (198).
Vol. 107, pp. 8091 (1985);
The composition can be synthesized according to a known method described in, for example, vol. 105, p. 1401 (1983), etc., but the synthesis method is not necessarily limited.

Representative examples of the aluminum porphyrin complex represented by the general formula (IV) include a compound group represented by the following (4).

[0032] (4) Representative examples of the aluminum porphyrin complex: In the general formula (IV), R ¹¹ and R ¹² are each a hydrogen atom, aluminum tetraphenylporphyrin complex R ¹³ is a phenyl group; R ¹¹ and R
Aluminum tetra (p-chlorophenyl) in which ¹² is a hydrogen atom and R ¹³ is a p-chlorophenyl group
An R ¹¹ and R ¹² are each a hydrogen atom, aluminum tetra (p- fluorophenyl) porphyrin complexes R ¹³ is p- fluorophenyl group; porphyrin complexes R ¹¹ and R ¹² are each hydrogen atom, R ¹³ Is a pentafluorophenyl group; an aluminum tetra (pentafluorophenyl) porphyrin complex; R ¹¹ and R ¹² are each a hydrogen atom, and R ¹³ is a p-methoxyphenyl group; an aluminum tetra (p-methoxyphenyl) porphyrin complex; An aluminum tetra (2,4,6-trimethoxyphenyl) porphyrin complex in which R ¹¹ and R ¹² are each a hydrogen atom and R ¹³ is a 2,4,6-trimethoxyphenyl group; R ¹¹ and R ¹²
Is a hydrogen atom, and R ¹³ is a p-methoxycarbonylphenyl group; an aluminum tetra (p-methoxycarbonylphenyl) porphyrin complex; R ¹¹ is a methyl group, R ¹² is an ethyl group, and R ¹³ is hydrogen An aluminum ethioporphyrin complex in which R ¹¹ and R ¹² are each an ethyl group and R ¹³ is a hydrogen atom; However, in the above representative examples, R ¹⁴ is an enolate based on a methyl methacrylate oligomer of 10 or less (eg:
Alkyl _{- (- CH 2 -C (CH} 3) (CO 2 CH 3) -) x-C
H ₂ -C (CH ₃ ) = C (OCH ₃ ) -O- (where x is 1 to
An enolate group such as an integer 9)); ethanethiolate, 1
-Propanethiolate, phenylthiolate, 2,6-
Di-t-butylbenzenethiolate, 2,6-di-t-
A thiolate group such as butyl-4-methylbenzenethiolate; or a hydrocarbon group having 1 to 10 carbon atoms such as an alkyl group such as methyl, ethyl, isopropyl and t-butyl.

As a typical example of the zinc porphyrin complex represented by the general formula (V), a compound group represented by the following (5) can be given.

(5) Representative example of a zinc porphyrin complex: a zinc tetraphenyl-N-methylporphyrin complex in which R ¹¹ and R ¹² are each a hydrogen atom and R ¹³ is a phenyl group in the general formula (V); A zinc tetra (p-chlorophenyl) -N-methylporphyrin complex in which R ¹¹ and R ¹² are each a hydrogen atom and R ¹³ is a p-chlorophenyl group; R ¹¹ and R ¹² are each a hydrogen atom, and R ¹³ is zinc tetra (p-fluorophenyl) -N-methylporphyrin complex which is a p-fluorophenyl group; zinc tetra (pentafluorophenyl) wherein R ¹¹ and R ¹² are each a hydrogen atom and R ¹³ is a pentafluorophenyl group —N-methylporphyrin complex; R ¹¹
And R ¹² are each hydrogen atom, R ¹³ is a zinc-tetra (p- methoxyphenyl) -N- methyl-porphyrin complex is p- methoxyphenyl group; a R ¹¹ and R ¹² are each a hydrogen atom, R ¹³ is A zinc tetra (2,4,6-trimethoxyphenyl) -N-methylporphyrin complex which is a 2,4,6-trimethoxyphenyl group; R ¹¹
And a zinc tetra (p-methoxycarbonylphenyl) -N-methylporphyrin complex in which R ¹² is a hydrogen atom and R ¹³ is a p-methoxycarbonylphenyl group; R ¹¹ is a methyl group, and R ¹² is an ethyl group And R
^A zinc ethio-N-methylporphyrin complex which is a hydrogen atom; R ¹¹ and R ¹² are each an ethyl group, and R ¹³
Is a hydrogen atom, such as a zinc octaethyl-N-methylporphyrin complex. However, in the above representative example, R
¹⁴ is an enolate based on a methyl methacrylate oligomer of 10 or less (eg, alkyl-(-CH ₂ -C (C
_{H 3) (CO 2 CH 3} ) -) x-CH 2 -C (CH 3) = C (OCH
₃ ) an enolate group such as -O- (where x is an integer of 1 to 9); ethanethiolate, 1-propanethiolate, phenylthiolate, 2,6-di-t-butylbenzenethiolate, 2,6-di- a thiolate group such as t-butyl-4-methylbenzenethiolate; or methyl, ethyl,
1 carbon atom such as an alkyl group such as isopropyl and t-butyl
And 10 to 10 hydrocarbon groups.

The metal porphyrin complex represented by the general formula (IV) or (V) can be used, for example, in Journal of Organic Chemistry (Journal of Organic Chemistry).
Organic Chemistry) 32, 476 (1967), Macromolecules (Ma)
Chromolecules), vol. 21, p. 1195 (1988), etc., but the synthesis method is not necessarily limited.

The above organometallic complex can be used by dissolving it uniformly in a solution constituting a polymerization reaction system, or can be used in the form of MgCl ₂ , MgCl (OC ₂ H ₅ ), Mg (OC ₂ H ₅ ).
₅ ) It can also be used by supporting it on a carrier such as ₂ , SiO ₂ or Al ₂ O ₃ . The use amount of the organometallic complex is not necessarily limited, but is in the range of 1 × 10 ^-4 to 1 × 10 ^-1 mol per mol of the vinyl monomer used in the first stage polymerization. Ratios are preferred.

Further, an organic aluminum compound such as trimethylaluminum, triethylaluminum, triisobutylaluminum or methylaluminoxane may be used in combination with the above-mentioned organometallic complex. The amount of these organoaluminum compounds used is not particularly limited, but is generally 1 to 1 with respect to the organometallic complex used.
It is 0 times or less.

In the first stage polymerization reaction according to the present invention, any of batch addition, continuous addition, and sequential addition may be employed as a method for adding the vinyl monomer to the reaction system. It is also possible to produce a block copolymer by using a plurality of types of vinyl monomers and making a difference in the timing of adding each monomer. The polymerization reaction may be carried out in the absence of a solvent in some cases, but is generally preferably carried out with stirring in a solution system in an organic solvent. Examples of the organic solvent include hydrocarbon solvents such as benzene, toluene, and xylene; halogenated hydrocarbon solvents such as chloroform, methylene chloride, and carbon tetrachloride; ether solvents such as tetrahydrofuran and diethyl ether; , Or in combination. The amount of the organic solvent to be used is not particularly limited, but is preferably in a range of 2 to 20 times the weight of the total amount of the monomers used in the two or more polymerization steps according to the present invention. The vinyl monomer and organic solvent used for polymerization must be sufficiently degassed and dried in advance using a dehydrating / drying agent such as calcium hydride, molecular sieves, or activated alumina under an inert gas stream. Is preferred. Further, the atmosphere of the polymerization reaction is preferably in an inert gas, and preferable inert gases include nitrogen, argon, helium and the like, and particularly preferably argon. Suitable conditions for the polymerization reaction temperature differ depending on the type of the organometallic complex or monomer used, but usually, a suitable temperature is appropriately selected from the range of -100 ° C to + 100 ° C. Can be. The required polymerization time is not necessarily uniform depending on the conditions such as the type of the organometallic complex or monomer used, and the polymerization temperature employed,
While analyzing the state of the monomer and the polymer present in the reaction system, the polymerization can be terminated when the desired state is achieved, but the polymerization time is usually from 0.1 minute to 24 hours. Within range. When a porphyrin complex is used as the organometallic complex, it is preferable to irradiate the reaction system with visible light during the polymerization reaction.

In the present invention, when the predetermined first-stage polymerization is achieved, an organic compound having a pKa value in the range of 5 to 20 and having no hydroxyl group (hereinafter, referred to as “the compound”) is added to the reaction system. The organic compound is sometimes referred to as “hydrogen atom dissociable organic compound”).

Representative examples of the hydrogen atom dissociable organic compound usable in the present invention include acetylacetone (pKa value 9), methyl acetoacetate (pKa value 11), dimethyl malonate (pKa value 13), and chloroacetone (pKa value 13). Value 1
7) compounds that form an enolate anion structure by dissociation of protons such as methyl phenoxyacetate (pKa value 15); compounds that form a thiolate anion structure by dissociation of protons such as thiophenol (pKa value 7). In addition, as a hydrogen atom dissociable organic compound, 3-chloro-2,4-pentanedione, methyl 2-chloroacetoacetate, dimethyl chloromalonate, methyl phenylacetate, methyl chloroacetate, methyl dichloroacetate,
Compounds forming an enolate anion structure by dissociation of protons such as methyl phenylthioacetate and dimethyl glutaconate; 2,6-di-t-butylbenzenethiol;
Compounds that form a thiolate anion structure by dissociation of a proton, such as 2,6-diisopropylbenzenethiol and 2,6-di-t-butyl-4-methylbenzenethiol, can also be used. It is not limited. In addition, two or more of these hydrogen atom dissociable organic compounds may be used in combination.

PKa in hydrogen atom dissociable organic compounds
The value refers to the acid dissociation constant (K) of the compound in an aqueous solution.
It is the product of the common logarithm value of a) and -1. The pKa value of the hydrogen atom dissociating organic compound used in the present invention needs to be in the range of 5 to 20, and the hydrogen atom which dissociates in the form of a proton at the pKa value in the range is derived from a hydroxyl group. It must not be. When the pKa value of the hydrogen atom dissociating organic compound is less than 5 (for example, the pKa value is 3
In the case of chloroacetic acid, which is a compound of the formula (1), and in the case where the hydrogen atom dissociable organic compound has a hydroxyl group (for example, in the case of methanol), when the organic compound is added after the first-stage polymerization, a vinyl monomer The active anion terminus of the active living polymer formed from the body loses its activity. At this time, a complex is formed from the metal coordinated to the active anion terminus and the added organic compound. It has no function as a polymerization initiating species for the vinyl monomer to be added.
Further, when the pKa value of the hydrogen atom dissociable organic compound is 21 or more (for example, in the case of methyl acetate having a pKa value of 25), even if the organic compound is added after the first-stage polymerization, The active anion terminal of the active living polymer generated from the vinyl monomer cannot lose its activity, and the vinyl monomer to be added next is continuously polymerized at the terminal of the active living polymer. A vinyl polymer having a number of molecules exceeding the number of molecules of the polymerization initiator obtained cannot be obtained.

The amount of the hydrogen atom dissociable organic compound to be used is not necessarily limited, but is preferably in the range of 1.0 to 20 times mol based on the organometallic complex used for the polymerization initiator. In addition, the above-mentioned hydrogen atom dissociable organic compound is sufficiently degassed and dried under an inert gas flow using a dehydrating / drying agent such as calcium hydride, molecular sieves, or activated alumina before use. Is preferred.

In order to increase the polymerization initiation reactivity with respect to the vinyl monomer added in the second stage, the second stage is carried out simultaneously with or after the addition of the hydrogen atom dissociable organic compound. Before the addition of the vinyl monomer, Lewis acids such as organoaluminum compounds such as bis (2,6-di-t-butyl-4-methylphenoxy) methylaluminum and organozinc compounds such as diethylzinc A compound; or a Lewis base compound such as an organic phosphorus compound such as hexamethylphosphoric triamide may be added as long as the effects of the present invention are not impaired.

The addition and reaction of the hydrogen atom-dissociable organic compound are preferably performed in an atmosphere of an inert gas. Preferred inert gases include nitrogen, argon, helium, etc., and particularly preferred. Argon. Suitable conditions for the reaction temperature vary depending on the type of the monomer and the hydrogen atom dissociable organic compound to be used, but are usually in the range of -100 ° C to + 100 ° C, preferably -80 ° C. To + 70 ° C. The time required for the reaction is not necessarily uniform depending on the type of the monomer or the hydrogen atom dissociable organic compound to be used, the reaction temperature to be employed, and the like, but is usually 0.1 minute to 10 minutes.
Within hours. In the case where a porphyrin complex is used as the organometallic complex in the polymerization reaction,
During the reaction using the hydrogen atom dissociable organic compound, it is preferable to irradiate the reaction system with visible light.

In the present invention, after the reaction of the above hydrogen atom dissociable organic compound, a vinyl monomer is added to the reaction system, and this is polymerized. In order to produce a vinyl polymer having the same chemical structure and molecular weight as the vinyl polymer produced by the polymerization of the vinyl monomer of the first stage, the first polymerization step comprises the steps of: It is preferable to carry out the polymerization reaction under the same conditions except that the same vinyl-based monomer as in the stage is used and the addition of the organometallic complex is not performed.

When the polymerization reaction of the second stage reaches a desired degree, the obtained reaction mixture is mixed with an organic compound having a hydroxyl group such as methanol, commercially available tetrahydrofuran which has not been subjected to a dehydration treatment, toluene or the like. The polymerization can be completed by adding an organic compound containing a large amount of water, water, or the like as a polymerization terminator. The amount of the polymerization terminator used is not particularly limited, but generally,
The ratio is preferably in the range of 1 to 100 moles based on the organometallic complex used. Further, when the polymerization of the vinyl monomer of the second stage reaches a desired degree, a hydrogen atom dissociable organic compound is added to the reaction system and reacted, and then the vinyl monomer is added. By adding a hydrogen atom dissociable organic compound and interposing a reaction step, such as performing a third-stage polymerization reaction of a vinyl monomer,
The polymerization reaction of the vinyl monomer can be further repeated.

The desired vinyl polymer is obtained from the reaction mixture after completion of the polymerization by addition of a polymerization terminator. The reprecipitation method comprises pouring the reaction mixture into a poor solvent for the polymer, and removing the solvent from the reaction mixture. It can be carried out by arbitrarily applying a known method such as a coagulation method comprising distillation.

[0048]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In the following Examples and Comparative Examples, the number average molecular weight of each polymer,
The molecular weight distribution was determined by gel permeation chromatography (hereinafter referred to as “GPC”). The production efficiency of the obtained vinyl polymer with respect to the polymerization initiator used was evaluated as follows.

(1) Production Efficiency of Vinyl Polymer The number average molecular weight (a1) of the polymer derived from only the monomer added in the first stage and the GPC curve of the product after completion of all the reaction steps , The number-average molecular weight (b1) of the polymer derived from only the monomer added in the second stage, and the GPC curve of the product after the completion of all the reaction steps. The peak area ratio (b2) of the polymer, the number average molecular weight (c1) of the polymer derived from both the monomer added in the first stage and the monomer added in the second stage, and the total reaction The area ratio of the peak of the polymer in the GPC curve of the product after the step (c
2) Based on the total yield (d) of the product after the completion of all the reaction steps, the number of molecules (Na) of the polymer derived from only the monomer added in the first stage is represented by the formula: d × a2 / a1,
The molecular number (Nb) of the polymer derived from only the monomer added in the second stage is represented by the formula: d × b2 / b1, where the monomer added in the first stage and the monomer added in the second stage are The molecular number (Nc) of the polymer derived from both of the monomers is represented by the formula: d × c2 / c1, and the production efficiency of the vinyl polymer is calculated by the formula: (Na + Nb)
+ Nc) / (number of polymerization initiator molecules).
In a normal living polymerization that does not involve a chain transfer reaction, the formula (Na) representing the production efficiency of the vinyl polymer described above:
+ Nb + Nc) / (number of polymerization initiator molecules) does not exceed 1.

Example 1 (1) First Stage Polymerization of Methyl Methacrylate In a 500 ml flask having an inner volume replaced with argon,
200 ml of toluene obtained by drying under sodium atmosphere after drying with sodium and a bis (pentamethylcyclopentadienyl) samarium methyl tetrahydrofuranate complex which is an organometallic complex containing a trivalent rare earth metal atom [(C ₅ Me ₅ ) ₂ Sm (CH ₃ ) (THF)] 0.51 g
(1.0 mmol) of a dry toluene solution (50 ml) was added. Then, at 0 ° C., 10 ml of methyl methacrylate (MMA) (94 mm
l) Added and stirred at 0 ° C. for 30 minutes. As a result of extracting a 10 ml sample from the system and dissolving about 0.2 ml of the sample in deuterated chloroform and measuring the ¹ H-NMR spectrum,
The unreacted rate of MMA was found to be less than 1%. In addition, the remaining of the sample solution withdrawn was methanol 200 ml.
The white precipitate [polymethyl methacrylate (PMMA)] was taken out and dried under reduced pressure to obtain 0.36 g (99% yield). A sample of the PMMA obtained in this manner was treated with tetrahydrofuran (TH
F), and the solution was measured by GPC. As a result, it was found that the number average molecular weight (Mn) was 9,400 and the molecular weight distribution (weight average molecular weight / number average molecular weight ratio; Mw / Mn) was 1.03. .

(2) Addition of a hydrogen atom dissociable organic compound
Reaction After the first stage polymerization of MMA, the reaction mixture was added at 0 ° C.
And 0.09 ml of dried and purified chloroacetone (pKa value: 17) as a hydrogen atom dissociable organic compound.
(1.1 mmol), and the mixture was stirred at 0 ° C. for 1 hour.

(3) Second Stage Polymerization of Methyl Methacrylate After the above reaction of chloroacetone, 20 ml of the second stage methyl methacrylate (188 m
mol) was added at 0 ° C, and the mixture was stirred at 0 ° C for 2 hours.

About 0.2 ml of a sample was extracted from the obtained reaction mixture, dissolved in deuterated chloroform, and ¹ H-NMR spectrum was measured. As a result, it was found that the unreacted rate of MMA was less than 1%. . Further, the entire amount of the remaining mixed solution extracted from the sample was poured into 4000 ml of methanol, and the obtained precipitate (PMMA) was taken out and dried under reduced pressure. The yield was 27.5 g (99% yield). When the obtained PMMA was dissolved in THF and measured by GPC,
The GPC curve has three peaks (peak area ratio is 55: 3
0:15), indicating that three types of PMMA were present. 3 whose peak area ratio is 55:30:15
Each kind of PMMA has a number average molecular weight (Mn) of 28
The molecular weight distribution (ratio of weight average molecular weight / number average molecular weight; Mw / Mn) was 1.04, 1.03 and 1.03, respectively. From these results, the production efficiency of the polymer was calculated to be 1.4.
It was one.

Example 2 Instead of the chloroacetone used in Example 1, 0.17 ml (1.2 m) of methyl phenoxyacetate (pKa value: 15) was used.
mol) except that it was used in the same manner as in Example 1.
As a result of polymerization of MMA in the second stage, addition and reaction of a hydrogen atom dissociable organic compound and polymerization of MMA in the second stage,
MMA was obtained in a yield of 27.3 g (98% yield). When the obtained precipitate was dissolved in THF and measured by GPC, the GPC curve showed three peaks (peak area ratio was 46:
36:18), and it was found that three types of PMMA were present. The three types of PMMA having a peak area ratio of 46:36:18 each have a number average molecular weight (Mn) of 2
8400, 18900 and 9500, and the molecular weight distributions (weight average molecular weight / number average molecular weight ratio; Mw / Mn) were 1.05, 1.03 and 1.04, respectively.
From these results, the polymer production efficiency was calculated as follows.
48.

Example 3 Instead of the bis (pentamethylcyclopentadienyl) samariummethyl tetrahydrofuranate complex used in Example 1 as a polymerization initiator, the enolate group of a pentamer of an axial group of methyl methacrylate (CH ₃ -(-CH _{2
-C (CH 3) (CO 2} CH 3) -) 4 -CH 2 -C (CH 3) = C
1.15 g (1.0 mmol) of an aluminum tetraphenylporphyrin complex (OCH ₃ ) —O—) was used, and 0.11 ml of thiophenol (pKa value 7) was used as a hydrogen atom dissociating organic compound instead of chloroacetone.
(1.1 mmol), the polymerization time of the first stage MMA was 2 hours, and the reaction time of the hydrogen atom dissociable organic compound was 3 hours.
Time and the polymerization time of the second stage MMA were changed to 5 hours, respectively, and all the polymerization and reaction times were irradiated with visible light (mercury lamp light obtained by cutting light having a wavelength of 420 nm or less through a filter). Except for the following, in the same manner as in Example 1, polymerization of MMA in the first stage, addition and reaction of a hydrogen atom dissociable organic compound, and MMA in the second stage
As a result, PMMA was obtained in a yield of 27.3 g (98% yield). The obtained precipitate was dissolved in THF and measured by GPC. The GPC curve had three peaks (peak area ratio was 68:21:11) and had three types of P
MMA was found to be present. The three types of PMMA having a peak area ratio of 68:21:11 have number average molecular weights (Mn) of 28300, 18900 and 9 respectively.
The molecular weight distribution (weight average molecular weight / number average molecular weight ratio; Mw / Mn) was 1.04, 1.03 and 1.04, respectively. From these results, the production efficiency of the polymer was calculated to be 1.28.

Comparative Example 1 Instead of chloroacetone having a pKa value of 17, pK
0.09 ml of methyl acetate having an a value of 25 (1.1 mm
ol), the same procedure as in Example 1 was used to carry out the polymerization of MMA in the first stage, the same operation as the addition and reaction of chloroacetone, and the same operation as the polymerization of MMA in the second stage. As a result, a yield of 27.6 g of PMMA (yield 99
%). The obtained precipitate is dissolved in THF and subjected to GPC.
As a result, it was found that the GPC curve had only one peak and that only one kind of PMMA was present. The obtained PMMA had a number average molecular weight (Mn) of 28,500 and a molecular weight distribution (ratio of weight average molecular weight / number average molecular weight; Mw / Mn) of 1.03. From these results, the production efficiency of the polymer was calculated to be 0.97.

Comparative Example 2 Instead of chloroacetone having a pKa value of 17, pK
0.1 ml of chloroacetic acid (1.1 mmol
Except for using l), the same procedure as in Example 1 was performed for the polymerization operation of MMA in the first stage, the same operation as the addition and reaction of chloroacetone, and the same operation as the polymerization for MMA in the second stage. As a result, 9.2 g of PMMA was obtained (33% yield). When the obtained precipitate was dissolved in THF and measured by GPC, it was found that the GPC curve had only one peak and that only one kind of PMMA was present. The obtained PMMA has a number average molecular weight (Mn) of 95.
The molecular weight distribution (weight-average molecular weight / number-average molecular weight ratio; Mw / Mn) was 1.03. From these results, the production efficiency of the polymer was calculated to be 0.97.

[0058]

As is apparent from the above examples, according to the production method of the present invention, a specific hydrogen atom dissociable organic compound is used in living polymerization of a vinyl monomer using an organometallic complex as a polymerization initiator. By adding, a desired vinyl polymer such as poly (methyl methacrylate) can be produced with a high yield and with an increased utilization efficiency of the polymerization initiator.

Claims (19)

[Claims] (1) A vinyl monomer is polymerized by using an organometallic complex as a polymerization initiator, and (2) a pKa value is added to a reaction system after polymerization obtained in the step (1). An organic compound in the range of 5 to 20 and having no hydroxyl group is added, the organic compound is reacted, and then (3)
A method for producing a vinyl polymer, comprising adding a vinyl monomer to the reaction system after the reaction obtained in the step (2), and polymerizing the vinyl monomer. 2. In the above steps (1) and (3),
The method according to claim 1, wherein an acrylate and / or a methacrylate is used as at least a part of the vinyl monomer. 3. The method according to claim 1, wherein the type of the vinyl monomer used is the same between the steps (1) and (3). 4. In the above steps (1) and (3),
Claims 1 to 4 each using a plurality of types of vinyl monomers.
4. The production method according to one of the three aspects. 5. In the above steps (1) and (3),
5. The production method according to claim 4, wherein the block copolymer is formed by making a difference in the addition time of a plurality of kinds of vinyl monomers. 6. The organic metal complex used in the step (1) is a metal of Group IIIA of the periodic table, a metal of Group IVA of the periodic table,
2. An organometallic complex of aluminum or zinc.
6. The production method according to any one of Items 1 to 5. 7. The use amount of the organometallic complex in the above step (1) is within a range of 1 × 10 ^-4 to 1 × 10 ^-1 mol based on the vinyl monomer used in the step (1). The method according to claim 1. 8. The method according to claim 1, wherein the organometallic complex used in the step (1) is supported on a carrier. 9. An organic aluminum compound is used in combination with the organometallic complex in the step (1).
The production method according to one of the above. 10. The method according to claim 1, wherein the polymerization in the steps (1) and (3) is carried out at a temperature within a range from -100 ° C. to + 100 ° C. 11. In the step (2), the organic compound having a pKa value in the range of 5 to 20 and having no hydroxyl group is a compound which forms an enolate anion structure or a thiolate anion structure by dissociation of a proton. The method according to claim 1. 12. In the step (2), the organic compound having a pKa value in the range of 5 to 20 and having no hydroxyl group is acetylacetone, methyl acetoacetate, dimethyl malonate, chloroacetone, methyl phenoxyacetate,
3-chloro-2,4-pentanedione, methyl 2-chloroacetoacetate, dimethyl chloromalonate, methyl phenylacetate, methyl chloroacetate, methyl dichloroacetate, methyl phenylthioacetate, dimethyl glutaconate, thiophenol, 2,6-di -T-butylbenzenethiol,
2,6-diisopropylbenzenethiol and 2,6
The method according to claim 11, which is at least one compound selected from the group consisting of -di-t-butyl-4-methylbenzenethiol. 13. The pKa value in the step (2) is 5
The amount of the organic compound having no hydroxyl group is in the range of 1.0 to 20 moles based on the organometallic complex used in the step (1).
3. The production method according to one of items 2. 14. The method according to claim 1, wherein a Lewis acid compound or a Lewis base compound is further added in the step (2).
14. The production method according to one of the thirteenth aspects. 15. The reaction in the step (2) is carried out by -10.
2. The method according to claim 1, wherein the heating is performed at a temperature within a range from 0 ° C. to + 100 ° C.
15. The production method according to any one of Items 14 to 14. 16. The above steps (1), (2) and (3)
An organic solvent is present in the reaction system in the above.
The production method according to one of the above. 17. The above steps (1), (2) and (3)
The method according to claim 1, wherein the reaction system is under an inert gas atmosphere.
The method according to one of the sixteenth aspects. 18. The above steps (1), (2) and (3)
The vinyl monomer used in the above and pKa value is 5
The method according to any one of claims 1 to 17, wherein the organic compound within the range of 20 and having no hydroxyl group has been dried in advance. 19. After the polymerization in the step (3),
(4) An organic compound having a pKa value in the range of 5 to 20 and having no hydroxyl group is added to the reaction system, and the organic compound is reacted. (5) The reaction obtained in the above step (4) 19. The production method according to claim 1, wherein a vinyl monomer is added to the subsequent reaction system, and the vinyl monomer is polymerized.