JPH11322835A - Catalyst for polymerizing polar vinyl monomer and production of polymer from the monomer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject catalyst for polymerization comprising a cobalt complex with coordinated phosphine ligand, capable of polymerizing many kinds of monomers and having a high catalytic activity. SOLUTION: This catalyst for polymerization comprises a cobalt complex with three coordinated phosphine ligands, pref. a complex of the formula, CH3 C (CH2 PPh2 )3 CoH(BH3 ) and is suitable for obtaining a polar polymer through homopolymerization of acrylonitrile or methacrylonitrile. The polar vinyl polymer is pref. obtained by polymerizing a polar vinyl monomer in a solventless state or in such an inert solvent as to be liquid while polymerization (e.g. opentane, hexane, etc.), at 0-80 deg.C for 0.5-100. The quantity consumed of the catalyst is 1×10<-4> -1×10<-2> mol, in terms of cobalt complex, per 1 mol polar vinyl monomer. The polymer is obtained in a yield <=60% and has a number average molecular weight of 1,000-1,000,000.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a catalyst for polymerizing a polar vinyl monomer and a method for producing a polar vinyl polymer.

[0002]

2. Description of the Related Art Vinyl polymers having a polar group in a side chain such as polyacrylonitrile and polymethyl methacrylate are:
It is known to have various functions compared to non-polar vinyl polymers. In order to impart higher functions to these polymers, it is considered that strict control of the primary structure of the resulting polymer is essential. Conventionally, these polymers are mainly synthesized by a radical polymerization method, but when using this polymerization method, since the growing species is a free radical, its reactivity is higher than other polymerization methods and it is difficult to control. However, it is difficult to control the primary structure of the resulting polymer, that is, the three-dimensional structure and molecular weight, or to strictly control the formation of the block polymer and the terminal groups, and so far no new functionality has been imparted.

On the other hand, in polymerization using an organometallic complex catalyst, a metal is always present in the vicinity of a growing species. Therefore, by selecting a combination of the central metal, a ligand and the like,
Since it is relatively easy to control the reactivity of the growing species and the direction of insertion of the monomer, it is considered that the polymerization method is more suitable for imparting the above-described functionality. For non-polar vinyl monomers such as ethylene, propylene, and styrene, stereoregular polymerization and living polymerization using organometallic complex catalysts have become possible based on this concept, and high functionality is achieved by controlling block polymers and terminal groups. The sex has been given.

The polymerization of a vinyl monomer having a polar group with an organometallic complex catalyst is significantly more difficult than the polymerization of the corresponding non-polar vinyl monomer because the polar group often acts as a catalyst poison. Have been.
Examples of the homopolymerization of polar vinyl monomers with organometallic complex catalysts known to date include (a) polymerization of various polar vinyl monomers with iron, cobalt and ruthenium complex catalysts (Journal of Polymer Science.
Polymer Review. , 13, 161 (197
8)), (b) Polymerization of methacrylic acid ester with rare earth complex catalyst (Journal of American Chemical Society, 114, 4908 (1992)),

(C) Polymerization of polar vinyl monomer by rare earth complex catalyst (Macromolecules., 29, 801)
4 (1996)), (d) Polymerization of methacrylic acid esters with a catalyst comprising a zirconocene complex and a boron compound (Macromolecules., 28, 3067 (199)
5)) and the like. However, most of the polymerization by these complexes is based on methacrylic esters, and there are few polymerization examples of acrylonitrile, and the polymerization rate is almost low. In many cases, the types of effective monomers are relatively limited.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a wide variety of monomers such as a polar vinyl monomer having a polar group such as acrylonitrile and methacrylate in a side chain and a vinyl monomer having an aromatic group such as styrene in a side chain. It is an object of the present invention to provide a polymerization catalyst capable of polymerizing a polymer and having a high catalytic activity, and a method for producing these vinyl polymers.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems. As a result, when a cobalt complex containing a tridentate phosphine ligand is used, acrylonitrile, methacrylonitrile, acrylic The present invention is completed by finding that a polymer having a high degree of polymerization can be obtained from a wide range of monomers such as a vinyl monomer having a polar group such as methyl acrylate and methyl methacrylate and a vinyl monomer having an aromatic group such as styrene in a side chain. Reached.

That is, the present invention is a catalyst for polymerizing a polar vinyl monomer, comprising a cobalt complex containing a tridentate phosphine ligand. Also, the present invention
A method for producing a polar vinyl polymer, comprising polymerizing a polar vinyl monomer in the presence of the catalyst for polymerizing a polar vinyl monomer.

[0009]

Embodiments of the present invention will be described below. Examples of the cobalt complex containing a tridentate phosphine ligand which is a catalyst for polymerizing a polar vinyl monomer of the present invention include those represented by the following general formula. X (C _n H _2n Y) ₃ CoH (BH ₃ ) wherein X is CH ₃ C or N, and Y is PR ₁₂ (R 1: aliphatic group or aromatic group) or P (0R ₂ ) ₂ (R 2 : Aliphatic group or aromatic group, and n is 1 ≦ n ≦ 3] Specific examples of these cobalt complexes include N (CH ₂ P
Ph ₂ ) ₃ CoH (BH ₃ ), CH ₃ C (CH ₂ PPh ₂ ) ₃ Co
H (BH ₃ ), CH ₃ C (CH ₂ P (C ₂ H ₅ ) ₂ ) ₃ CoH
(BH ₃ ), CH ₃ C (CH ₂ P (OC ₂ H ₅ ) ₂ ) ₃ CoH
(BH ₃ ), CH ₃ C (CH ₂ P (OPh) ₂ ) ₃ CoH (B
H ₃ ). Of these, particularly preferred cobalt complexes include CH ₃ C (CH ₂ PPh ₂ ) ₃ CoH (B
H ₃ ), wherein Ph is a phenyl group.

The polar vinyl monomer applicable in the present invention is a vinyl monomer having a polar group such as a cyano group, a carboxyl group, an alkoxycarbonyl group, and a phenyl group in a side chain. Such materials include acrylonitrile, methacrylonitrile, methacrylate, acrylate, styrene and the like. The polymerization catalyst of the present invention is particularly suitable for homopolymerizing acrylonitrile and methyl methacrylate to produce their polar polymers.

In order to obtain a polar vinyl polymer according to the present invention, a polar vinyl monomer is polymerized in the presence of the polymerization catalyst. In this case, the polymerization reaction is desirably performed without a solvent or in a solvent that is inert to the polymerization reaction and is liquid at the time of polymerization. Examples of the polymerization solvent in this case include saturated aliphatic hydrocarbons such as pentane, hexane and heptane, saturated cyclic hydrocarbons such as cyclohexane and cycloheptane, aromatic hydrocarbons such as benzene and toluene, and N, N-dimethylhofm. Examples include a nitrogen-containing solvent such as amide (DMF).

The amount of the catalyst used for homopolymerizing the polar vinyl monomer cannot be specified unconditionally. For example, the ratio of the Co complex is 1 × 10 ^-4 mol to 1 × 10 ^-2 mol per mol of the polar vinyl monomer. It is. The polymerization is usually carried out at 0 to 80 ° C. for 0.5 to 100 hours.
The yield of the obtained polymer varies depending on the polymerization temperature, the polymerization time, the amount of the catalyst, the type and amount of the solvent, and the like.
0% or less. Furthermore, the number average molecular weight of the obtained polymer also depends on the polymerization conditions, etc.
0 to about 1,000,000.

[0013]

The present invention will be described below in more detail with reference to examples. The molecular weight of the polymer was measured using GPC, the developing solvent was N, N-dimethylformamide (DMF), and the column temperature was 40 ° C. The measured molecular weight is in terms of polystyrene.

Example 1 A 20 mL flask sufficiently purged with nitrogen gas was charged with DM.
3 mL of F, 3 mL of acrylonitrile, and 7.5 mmol of CH ₃ C (CH ₂ PPh ₂ ) ₃ CoH (BH ₃ ) were added, and the mixture was stirred at room temperature for 15 minutes. The reaction solution was poured into hydrochloric acid-methanol to precipitate a polymer, and the polymer was dried. As a result, 49% of the polymer relative to the charged monomers was obtained. GPC analysis of the produced polymer showed a number average molecular weight (Mn).
Was 520000.

Example 2 In the same manner as in Example 1, acrylonitrile was polymerized at room temperature for 3 minutes to obtain a polymer with a yield of 32%. GPC analysis of the resulting polymer revealed a number average molecular weight (M
n) was 500,000.

Example 3 In the same manner as in Example 1, when methyl methacrylate was polymerized at room temperature for 24 hours, a polymer was obtained with a yield of 23%. GPC analysis of the resulting polymer showed a number average molecular weight (Mn) of 43,000.

Example 4 In the same manner as in Example 1, methacrylonitrile was polymerized at room temperature for 3 hours to obtain a polymer in a yield of 12%. GPC analysis of the resulting polymer showed a number average molecular weight (Mn) of 35,000.

Example 5 As in Example 1, styrene was polymerized at room temperature for 24 hours to obtain a polymer in a yield of 15%. GPC analysis of the resulting polymer showed a number average molecular weight (Mn) of 15,000.

As is clear from the results of the examples, the cobalt complex containing a tridentate phosphine ligand, CH ₃ C (CH ₂ PPh ₂ ) ₃ CoH (B
H ₃ ) readily produces polymers when used in the polymerization of many types of polar vinyl monomers, such as acrylonitrile and methacrylate. Particularly in the polymerization of acrylonitrile, a polymer having a high molecular weight is produced in a very short time in a high yield.

[0020]

Industrial Applicability The catalyst of the present invention can be used for polymerization of various polar vinyl monomers, and a polar vinyl polymer can be obtained in a good yield.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Masanao Kawabe 2-6-1203 Takezono, Tsukuba-shi, Ibaraki Prefecture (72) Inventor Kazuo Soga 9-6-1, Midorigaoka, Tatsunokuchi-cho, Nomi-gun, Ishikawa Prefecture (72) Inventor Michihiko Asai 3-711 Namiki, Tsukuba, Ibaraki Prefecture (72) Inventor Yasuzou Suzuki 2-805-808, Azuma, Tsukuba, Ibaraki (72) Inventor Tetsu Miyazawa 4-403, 103-103 Matsushiro, Matsushiro, Tsukuba, Ibaraki Prefecture ( 72) Inventor: Masahide Murata, 2-3-15-1, Suido, Bunkyo-ku, Tokyo (72) Inventor: Toshio Kase 5-2-2, Matsushiro, Tsukuba-shi, Ibaraki (72) Inventor: Hiroyuki Ozaki 4-chome Onogawa, Tsukuba-shi, Ibaraki No. 6-202 (72) Inventor Yoshifumi Fukui 4-6-1 Ninomiya 4-507, Tsukuba, Ibaraki Prefecture

Claims (3)

[Claims] 1. A catalyst for polymerizing a polar vinyl monomer, comprising a cobalt complex containing a tridentate phosphine ligand. 2. The catalyst for polymerizing a polar vinyl monomer according to claim 1, wherein the cobalt complex is represented by the following chemical formula: CH ₃ C (CH ₂ PPh ₂ ) ₃ CoH (BH ₃ ). 3. A method for producing a polar vinyl polymer, comprising polymerizing a polar vinyl monomer in the presence of the polymerization catalyst according to claim 1 or 2.