JP2850152B2 - Method for producing ethylene copolymer - Google Patents

Description

The present invention relates to a method for efficiently producing an ethylene-based block copolymer by copolymerizing ethylene and an unsaturated carboxylic acid ester in the presence of a trivalent organic lanthanide compound. About.

[Conventional Technology and Problems to be Solved] Conventional polyolefins have a defect that they have poor polarizability, printability and compatibility with other polymers because there is no polar group in the molecule.

In order to improve these drawbacks, attempts have been made to copolymerize an α-olefin with a polar vinyl monomer. For example, JP-A-59-43003 discloses that TiCl ₄ , Al
A method for copolymerizing propylene with an unsaturated carboxylic acid ester using (C ₂ H ₅ ) ₂ Cl as a catalyst has been proposed. According to JP-A-64-14217, copolymerization of ethylene and an unsaturated carboxylic acid ester using a zero-valent nickel chelate compound and an aluminoxane has been proposed, but any of them requires a large amount of Lewis acid. However, there is a problem that a large excess of aluminoxane as a cocatalyst is required.

The present inventors have already reported the synthesis of an ethylene-MMA block copolymer using a dinuclear complex of a divalent lanthanide compound and an alkyl aluminum (Preprints of the 58th Annual Meeting of the Chemical Society of Japan I, 1 II B07) However, when such a divalent lanthanide compound is used, there is a problem that the polymerization activity is low.

[Means for Solving the Problems] The inventors of the present invention have conducted intensive studies and found that
A trivalent yttrium compound or a trivalent lanthanide compound having two (substituted) cyclopentagenyl groups or a trivalent lanthanide compound or an organoaluminum compound is used as an initiator (also referred to as a catalyst) to polymerize ethylene in a living manner and at the growth terminal The present inventors have found that an ethylene-unsaturated carboxylic acid ester block copolymer can be obtained by acting an unsaturated carboxylic acid ester, thereby completing the present invention.

In the present invention, when block copolymerizing ethylene and an unsaturated carboxylic acid ester, a trivalent yttrium compound or a trivalent lanthanide compound having two (substituted) cyclopentadienyl groups or an organoaluminum compound is used. The present invention relates to a method for producing a block copolymer of ethylene and an unsaturated carboxylic acid ester, which is used as an initiator.

The trivalent organic Y compound and the trivalent organic lanthanide compound which can be used in the present invention are represented by formulas (1) and (2). [Wherein R _{1 to} R ₁₀ are a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms or a silicon-containing hydrocarbon group, and R _{1 to} R ₁₀ are bonded to an adjacent R group via a hydrocarbon group. May be. In the present invention, "(substituted) cyclopentadienyl group" means an unsubstituted or substituted cyclopentadienyl group. M is Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Ga, Tb, D
They are y, Ho, Er, Tm, Yb, and 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, bispentamethylcyclopentadienyl lutetium bistrimethylsilylmethyl, biscyclopentadienyl ytterbium hydride, biscyclopentadienyl ytterbium methyl, bispentamethylcyclopentadi Any ytterbium hydride, bispentamethylcyclopentadienyl ytterbium methyl, bispentamethylcyclopenta Any ytterbium bistrimethylsilylmethyl, biscyclopentadienyl samarium hydride, biscyclopentadienyl samarium methyl, bispentamethylcyclopentadienyl samarium hydride, bispentamethylcyclopentadienyl samarium methyl, bispentamethylcyclopentadi Enylsamarium bistrimethylsilylmethyl, biscyclopentadienyl europium hydride, biscyclopentadienyl europium methyl, bispentamethylcyclopentadienyl europium hydride, bispentamethylcyclopentadienyl europium methyl, bispentamethylcyclo Pentadienyl neodymium methyl, bispentamethylcyclopentadienyl cerium hydride, bispentame Le cyclopentadienyl yttrium methyl, bis indenyl lutetium methyl, ethylene bis indenyl lutetium methyl,
Examples include, but are not limited to, ethylene biscyclopentadienyl lutetium methyl and their compounds noetherate, tetrahydrofuranate, and the like.

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 formula (3) AlR _n X _3-n (3) wherein R is an aliphatic hydrocarbon group, X is a halogen element, and n =
Integer of 1-3] The carboxylic acid ester used in the present invention is represented by the formula (4) or (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.

In the polymerization, the above-mentioned trivalent organic Y compound and trivalent organic lanthanide compound are used as a catalyst in an inert gas, ethylene is introduced as a first monomer at normal pressure in the presence of a solvent, and ethylene polymerization is performed. A block copolymer is obtained by adding an unsaturated carboxylic acid ester as a monomer into the system and copolymerizing the system.

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 hexane, heptane, benzene, toluene and xylene, tetrahydrofuran and ether, all of which are complete. It is preferable to use dewatered and degassed water.

As the unsaturated carboxylic acid ester monomer used for the polymerization, one that has been sufficiently dried with calcium hydride or molecular 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 about room temperature.

One feature of the production method of the present invention is that a block copolymer having a narrow molecular weight distribution can be produced.

By using the production method of the present invention, an ethylene-based block copolymer having a narrow molecular weight distribution can be easily synthesized.

In addition, the present method comprises the use of a halide of a corresponding trivalent organic Y compound and an organic lanthanide compound (for example, biscyclopentadienyl lutetium chloride, bispentamethylcyclopentadienyl ytterbium bromide, etc.) and an equivalent or less of an alkyl alkali. The reaction of the compound in the system also serves as a polymerization catalyst.

Further, in the present invention, when the catalyst concentration and the ethylene monomer concentration are determined, the degree of polymerization of the ethylene chain portion of the copolymer can be freely controlled by adjusting the reaction temperature and the polymerization time. Another major feature is that the degree of polymerization of the carboxylic acid ester portion of the block copolymer can be freely controlled by adjusting the concentration of the acid ester and the polymerization time.

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 copolymers produced in Examples and Comparative Examples was CP
The molecular weight distribution was estimated by Mw / Mn. The quantitative ratio of ethylene and carboxylic acid ester in the copolymer was calculated from ¹ H-NMR and ¹³ C-NMR.

Example 1 A toluene solution of bispentamethylcyclopentadienyl ytterbium methyl monoetherate synthesized by a known method (PLWatson, ACS Symp., 495, 1983.) in a well-dried argon gas purged 50 ml flask (0.02
M) 1 ml and dry-toluene 20 ml were charged, and the argon gas was replaced with ethylene by cooling under reduced pressure. After that, the temperature was raised to a polymerization temperature of 30 ° C. while stirring using a magnetic stirrer. After ethylene polymerization was performed for 5 minutes, unreacted ethylene gas was replaced with argon gas again under cooling and reduced pressure. At this time, the produced polyethylene was sampled with a syringe at 5 ml. 1 ml of methyl methacrylate dried with calcium hydride and molecular sieve was added to the remaining reaction solution with a syringe, and stirring was continued for about 1 hour. After the reaction, the reaction solution was poured into a large amount of methanol to precipitate a polymer. The obtained polymer was heated and refluxed in chloroform, and the chloroform-insoluble portion was collected by filtration. After drying, weighing, GPC, and NMR measurement were performed.

Example 2 The same procedure as in Example 1 was carried out except that the polymerization time for polyethylene was changed to 10 minutes.

Example 3 It carried out similarly to Example 1 except having made polyethylene polymerization time into 15 minutes.

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 time of polyethylene was 1 minute.

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 time of polyethylene was 3 minutes.

Comparative Example 1 Copolymerization was carried out in the same manner as in Example 1 except that bispentamethylytterbium bistetrahydrofuranate (divalent) was used as an initiator, but no copolymer was obtained.

Example 6 The same operation as in Example 1 was performed except that bispentamethylcyclopentadienyl ytterbium methyltrimethylaluminum was used as an initiator.

 Table 1 summarizes the results of Examples 1 to 6.

Example 7 It carried out like Example 1 except using bispentamethylcyclopentadienyl ytterbium methyl as an initiator and using methyl acrylate as a monomer.
Yield 57mg.

Example 8 Example 8 was repeated except that bispentamethylcyclopentadienyl lutetium methyl monoetherate was used as the initiator and the polymerization time of polyethylene was changed to 10 minutes.

Example 9 The same operation as in Example 1 was carried out except that bispentamethylcyclopentadienyl yttrium methyl monoetherate was used and the polymerization time of polyethylene was changed to 5 minutes.

 Table 2 shows the results of Examples 8 and 9.

[Effects of the Invention] By blending the copolymer of the present invention with a thermoplastic resin such as polyolefin, various properties of the resin can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an IR spectrum of the polyethylene-PMMA copolymer obtained in Example 1. (Those obtained in Examples 2 to 6 also showed similar spectra.)

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C08F 297/06-297/08 C08F 4/52 C08F 4/60-4/70 C08F 10/00-10 / 14 C08F 110/00-110/14 C08F 210/00-210/18 C08F 20/00-20/40 C08F 120/00-120/40 C08F 220/00-220/40 CAS ONLINE

Claims (2)

(57) [Claims] (1) When block copolymerizing ethylene and an unsaturated carboxylic acid ester, a trivalent yttrium compound or a trivalent lanthanide compound having two (substituted) cyclopentadienyl groups is used as an initiator. A method for producing a block copolymer of ethylene and an unsaturated carboxylic acid ester, which is a feature of the present invention. 2. A block copolymer of ethylene and an unsaturated carboxylic acid ester is started with a trivalent yttrium compound or trivalent lanthanide compound having two (substituted) cyclopentadienyl groups and an organoaluminum compound. A method for producing a block copolymer of ethylene and an unsaturated carboxylic acid ester, which is used as an agent.