JP2882674B2 - Process for producing polymethacrylate and polyacrylate - Google Patents

Description

The present invention relates to a method for producing syndiotactic polymethacrylate and syndiotactic polyacrylate having a narrow molecular weight distribution and a high molecular weight.

[Prior Art and Problems to be Solved] Conventionally, as a known technique relating to the production of polyacrylic acid esters having a narrow molecular weight distribution, many methods by anionic polymerization using alkali metal and alkaline earth metal compounds are known. For example, when lithium in liquid ammonia is used as an initiator, one having a relatively narrow molecular weight distribution of Mw / Mn = 1.5 can be obtained (WEGood, J. Polym. Sci., 42, 367, 196).
0). When 1,1-diphenylhexyllithium is used, polymethyl methacrylate having Mw / Mn = 1.18 can be obtained (H. Hatada, Kobunshi Ronbunshu, 43, 857, 1986). In addition, a polymethyl methacrylate having Mw / Mn of about 1.2 can be obtained by the Grignard reagent, but the molecular weight distribution is narrow and the syndiotacticity is not sufficient.

As a method for producing a polyacrylate having an extremely narrow molecular weight distribution, a method using sodium-biphenyl (A. Roig, J. Polym. Sci., B3, 171, 1965), a method using aluminum-porphyrin (Japanese Unexamined Patent Publication No. -259008), but has problems such as a low molecular weight of the produced polymer, a low polymerization rate, and the necessity of using an expensive polar solvent.

The present inventors have already reported that syndiotactic polymethyl methacrylate having a high molecular weight and a relatively narrow molecular weight distribution can be obtained using a lanthanide divalent compound as an initiator (Proceedings of the 58th Annual Meeting of the Chemical Society of Japan). I, 1 II B07,198
9). The polymerization using this lanthanide divalent compound as an initiator has attracted attention because it is a living polymerization and a polymer having a narrow molecular weight distribution can be obtained.

However, the molecular weight distribution of polymethyl methacrylate produced by the lanthanide divalent compound is not so narrow as Mw / Mn = 1.2, and the initiator efficiency is as low as 25%. In addition, the lanthanide divalent compound had no polymerization initiating ability with respect to the acrylate.

[Means for Solving the Problems] The inventors of the present invention have conducted further intensive studies and have found that an organic Sc compound, an organic Y compound, an organic lanthanide compound, or a compound obtained from these and an organic aluminum is used as an initiator. When the polymerization of acrylates and methacrylates is performed, the polymerization proceeds in a living manner, the molecular weight distribution is narrower, and it is possible to efficiently obtain high molecular weight polyacrylates and polymethacrylates with initiator efficiency. It has been found that the present invention has been sensitized.

The present invention relates to a trivalent organic Sc compound, a trivalent organic Y compound or a trivalent organic lanthanide (La, Ce, Pr, Nd, P
m, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) or a compound obtained from these and organoaluminum is used as an initiator, and polymethacrylic acid having a narrow molecular weight distribution is used. The present invention relates to a method for producing an ester and a polyacrylate.

The trivalent organic Sc compound, trivalent organic Y compound and trivalent organic lanthanide compound which can be used in the present invention are represented by the formula (1)
(2) [Wherein R _{1 to} R ₁₀ are a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms or a hydrocarbon group containing silicon, and R _{1 to} R ₁₀ are bonded to an adjacent R group via a hydrocarbon group. You may. M
Is Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dv, H
o, Er, Tm, Yb, Lu. X is a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, or a hydrocarbon group containing keiso. Y is an alkylene group or an alkylsilyl group having 1 to 3 carbon atoms. D is a solvent molecule and n = 0 to 3. ].

Examples of such compounds include biscyclopentadienyl lutetium hydride,
Biscyclopentadienyl lutetium methyl, biscyclopentadienyl lutetium ethyl, biscyclopentadienyl lutetium bistrimethylsilylmethyl, bispentamethylcyclopentadienyl lutetium hydride, bispentamethylcyclopentadienyl lutetium methyl, bispentamethylcyclo Pentadienyl lutetium bistrimethylsilylmethyl, biscyclopentadienyl ytterbium hydride, biscyclopentadienyl ytterbium methyl, bispentamethylcyclopentadienyl ytterbium hydride, bispentamethylcyclopentadienyl ytterbium Methyl, bispentamethylcyclopentadienyl ytterbium bistrimethylsilylmethyl, biscyclopentadienyl Malium hydride, biscyclopentadienyl samarium methyl, bispentamethylcyclopentadienyl samarium hydride, bispentamethylcyclopentadienyl samarium methyl, bispentamethylcyclopentadienyl samarium bistrimethylsilylmethyl, biscyclopentadienyl europium Hydride, biscyclopentadienyl europium methyl, bispentamethylcyclopentadienyl europium hydride, bispentamethylcyclopentadienyl europium methyl, bispentamethylcyclopentadienyl neodymium methyl, bispentamethylcyclopentadienyl Cerium hydride, bispentamethylcyclopentadienyl yttrium methyl, bispentamethylcyclopentadie Ruscandium hydride, bispentamethylcyclopentadienyl scandium methyl, bisindenyl lutetium methyl, ethylene bisindenyl lutetium methyl, ethylene biscyclopentadienyl lutetium methyl and these compounds, such as noetherate and tetrahydrofuranate. It is not limited.

These compounds can be prepared by known methods (Tobin J. Marks, JA
m.Chem.Soc., 107,8091,1985.; William.J.Evans, J.Am.Ch
em. Soc., 105, 1401, 1983 .; PLWatson, ACSSymp., 495,
1983 .; Tobin J. Marks, WO 8605788), but is not limited by the synthesis method.

The organoaluminum compound used in the present invention is represented by the following formula (3): AlR _n X _3-n [where R is an aliphatic hydrocarbon group, X is a halogen element, n
= An integer of 1 to 3] As the acrylate and methacrylate used in the present invention, formulas (4) and (5) [In the formula, R is a monovalent group selected from an aliphatic hydrocarbon group, an aromatic hydrocarbon group, and a hydrocarbon group containing a functional group such as halogen, amine, and ether. ] Can be effectively used.

Specifically, methyl acrylate, ethyl acrylate,
N-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, sec-butyl acrylate, t-butyl acrylate, isoamyl acrylate, lauryl acrylate, benzyl acrylate,
Phenyl acrylate, vinyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, methacrylic acid Isoamyl, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate, allyl methacrylate,
Vinyl methacrylate, benzyl methacrylate, phenyl methacrylate, naphthyl methacrylate, methacrylic acid 2
-Methoxyethyl, diethylene glycol monomethyl methacrylate, 2-dimethylaminoethyl methacrylate, and the like, but are not limited thereto.

The polymerization is carried out in an inert gas using the above-described organic Sc trivalent compound, organic Y trivalent compound and trivalent organic lanthanide compound as an initiator, and charging a predetermined amount of a monomer, acrylate or methacrylate, in the presence of a solvent. is there.

As the inert gas, nitrogen, helium, argon or the like is used, but argon is preferable.

Solvents used for the polymerization include halogenated hydrocarbons such as methylene chloride, chloroform and carbon tetrachloride, hydrocarbons such as benzene, toluene and xylene, tetrahydrofuran and ether, all of which are completely dehydrated and degassed. It is good to use what was done. Further, polymerization can be performed without a solvent.

As the monomer used for the polymerization, one that has been sufficiently dried with calcium hydride or monocular sieve and distilled under an inert gas immediately before being used for the polymerization is used.

The polymerization temperature can be in a wide range from the freezing point to the boiling point of the solvent used, but is preferably room temperature or lower.
One of the features of the production method of the present invention is that polyacrylates and polymethacrylates having a narrow molecular weight distribution can be produced in a wide temperature range from the freezing point of the solvent to room temperature.

By using the production method of the present invention, polyacrylates and polymethacrylates having a narrow molecular weight distribution can be easily synthesized.

In addition, the present method comprises the use of an equivalent amount of a halide of an organic trivalent compound of organic Sc, a trivalent compound of organic Y and an organic lanthanide compound (eg, biscyclopentadienyl lutetium chloride, bispentamethylcyclopentadienyl ytterbium bromide, etc.). A polymerization catalyst can also be obtained by reacting the following alkyl alkali compounds in a system.

Further, in the present invention, when the initiator concentration and the monomer concentration are determined, the molecular weight of the produced polymer can be freely controlled with a narrow molecular weight distribution over a wide range of 1,000 to 1,000,000 by adjusting the reaction temperature and the polymerization time. It is.

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.

The molecular weight of the polymers produced in Examples and Comparative Examples was GP
It was determined by C (gel permeation chromatography), and the molecular weight distribution was estimated by Mw / Mn. The regularity of the polymer was calculated by ¹ H-NMR.

Example 1 A toluene solution of bispentamethylcyclopentadienyl ytterbium methyl monoetherate synthesized by a known method (PLWatson, ACS Symp., 495, 1983.) was placed in a 50 ml flask which had been sufficiently dried and purged with argon gas. 0.02
M) 1 ml and dry-toluene 20 ml were charged, and the polymerization temperature was adjusted to 0 ° C. while stirring using a magnetic stirrer. To this, 1 ml of methyl methacrylate dried over calcium hydride and molecular sieve was added via syringe. After the reaction, the reaction solution was poured into a large amount of methanol to precipitate a polymer, washed, dried, weighed, and subjected to GPC measurement.

Example 2 The same procedure as in Example 1 was carried out except that the polymerization temperature was changed to -40 ° C.

Example 3 Example 3 was repeated except that bispentamethylcyclopentadienyl samarium hydride was used as an initiator.

Example 4 The same operation as in Example 1 was carried out except that bispentamethylcyclopentadienyl samarium hydride was used as an initiator and the polymerization temperature was -40 ° C.

Example 5 The same operation as in Example 1 was carried out except that bispentamethylcyclopentadienyl samarium hydride was used as an initiator and the polymerization temperature was -78 ° C.

Example 6 It carried out like Example 1 except using bispentamethylcyclopentadienyl samarium bistrimethylsilylmethyl as an initiator.

Example 7 The same operation as in Example 1 was carried out except that bispentamethylcyclopentadienyl samarium bistrimethylsilylmethyl was used as an initiator and the polymerization temperature was -40 ° C.

Example 8 Example 8 was repeated except that bispentamethylcyclopentadienyl ytterbium methyltrimethylaluminum was used as the initiator.

Example 9 The same operation as in Example 1 was carried out except that bispentamethylcyclopentadienyl samarium hydride was used as an initiator and methyl acrylate was used as a monomer.

Comparative example 1 It carried out like Example 1 except using 1,1, diphenylhexyl lithium as an initiator.

Table 1 summarizes the conditions and results of Example 1-9 and Comparative Example 1 described above.

[Effects of the Invention] According to the method of the present invention, it is possible to produce syndiotactic polymethacrylates and polyacrylates having a narrow molecular weight distribution and a high molecular weight. This polymer is GPC (gel permeation chromatograph)
Ideal as a reference material for

Claims (2)

(57) [Claims] 1. a) a trivalent organic Sc compound; b) a trivalent organic Y compound; c) a trivalent organic lanthanide (La, Ce, Pr, Nd, Pm,
Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) Compound
A process for producing a polymethacrylate ester and a polyacrylate ester, characterized in that at least one organometallic compound of the group consisting of a), b) and c) is used as an initiator. 2. a) a trivalent organic Sc compound; b) a trivalent organic Y compound; c) a trivalent organic lanthanide (La, Ce, Pr, Nd, Pm,
Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) Compound
A method for producing a polymethacrylic acid ester and a polyacrylic acid ester, wherein a compound obtained from at least one organometallic compound of the group consisting of a) b) c) and an organoaluminum is used as an initiator.