JPH05310813A - Production of poly@(3754/24)alpha-methylstyrene) macromonomer - Google Patents

Abstract

PURPOSE:To obtain a poly(alpha-methylstyrene) macromonomer having a narrow mol.wt. distribution by polymerizing alpha-methylstyrene by cationic living polymerization using a polymerization initiator comprising a combination of a specific halogenated ethylenic compound and a metal halide serving as a Lewis acid. CONSTITUTION:alpha-Methylstyrene is polymerized by cationic living polymerization using as a polymerization initiator a combination of an organohalogen compound (a) represented by the formula CH3-CHX-O-CH2CH2-Y (wherein X is a halogen and Y is a substituent having an ethylenically unsaturated bond) and a metal halide (b) serving as a Lewis acid. The ratio of the compound (a) to the halide (b) is preferably 1:(0.5-4) by mole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a radical-polymerizable poly .alpha.-methylstyrene type macromonomer having a vinyl-polymerizable group at one end of the molecule, more specifically, a specific polymerization initiator. Thus, a poly α-methylstyrene type macromonomer having a polymer skeleton formed by living cationic polymerization and having an extremely narrow molecular weight distribution can be easily obtained.

[0002]

2. Description of the Related Art A graft copolymer obtained by copolymerizing a macromonomer having a narrow molecular weight distribution with another monomer is ideal as a graft copolymer because of its uniform branch length. It has a structure and is superior in physical properties to a graft copolymer having random branch lengths.

A method of synthesizing such a macromonomer having a narrow molecular weight distribution has been known for a long time. For example, Japanese Patent Application Laid-Open No. 54-10996 discloses vinyl such as styrene, α-methylstyrene and acrylamide. A method has been proposed in which a living monomer is subjected to living anionic polymerization and then the resulting living polymer is reacted with a terminating agent such as allyl chloride, vinylbenzyl chloride or vinyl 2-chloroethyl ether to produce a macromonomer.

[0004]

However, in the living anionic polymerization method, even slight impurities in the polymerization system pose a problem, and in the case of water, the polymerization will not proceed unless the impurities are almost completely removed, and therefore industrialization is easy. However, the production of macromonomers by such living anionic polymerization method is not actually widely practiced. In contrast to the above living anionic polymerization method, the living cationic polymerization method has less influence of impurities on the polymerization, and thus the polymerization initiator 1
It is generally known that there is no problem even if about 0.04 to 0.06 mol of water is mixed per mol [for example, Ma
cromolecules,
Volume 17, p. 265 (1984)]. Therefore, if the living cationic polymerization method can be used for producing a macromonomer, it becomes possible to synthesize a macromonomer having a narrow molecular weight distribution without requiring a high-level purification operation for the monomer and the solvent.

In view of the above circumstances, the present inventors provide a method for producing a radically polymerizable macromonomer by living cationic polymerization, which has a skeleton of a polymer consisting of α-methylstyrene which is industrially useful as well as styrene. As a result of extensive studies aimed at achieving the use of a polymerization initiator composed of a specific organic halogen compound having an ethylenically unsaturated bond and a metal halide having Lewis acidity, α-methylstyrene having a narrow molecular weight distribution is obtained. It was found that a macromonomer having an ethylenically unsaturated bond derived from the organic halogen compound at the terminal can be obtained in high yield, which is a polymer of The manufacturing method has been completed.

[0006]

The method for producing a poly .alpha.-methylstyrene type macromonomer of the present invention uses, as a polymerization initiator, a compound represented by the following general formula (wherein X is a halogen atom and Y is ethylene). Is a substituent having a polar unsaturated bond) and a metal halide having Lewis acidity, and α-methylstyrene is subjected to living cationic polymerization. .. Chemical formulas 1 and 2 in the specification have the same chemical formula.

[0007]

Embedded image CH ₃ —CHX—O—CH ₂ CH ₂ —Y

The substituent Y of the organohalogen compound represented by the chemical formula 2 used as one component of the polymerization initiator in the present invention is represented by the chemical formula of the following chemical formula 3 or the chemical formula of the following chemical formula 4 (meth) acryloyl. Examples thereof include an oxy group, an allyloxy group and a vinylbenzyloxy group represented by the chemical formula 5 below, and a (meth) acryloyloxy group is more preferable.

[0009]

Embedded image —OC (═O) —CH═CH ₂

[0010]

Embedded image —OC (═O) —C (CH ₃ ) ═CH ₂

[0011]

Embedded image —O—CH ₂ —CH═CH ₂

Specific examples of the organic halogen compound represented by the general formula of Chemical formula 2 include 1- (2-allyloxyethoxy)
Examples thereof include ethyl halide, 1- (2-acryloyloxyethoxy) ethyl halide, 1- (2-methacryloyloxyethoxy) ethyl halide and 1- (2-vinylbenzyloxyethoxy) ethyl halide. Among these compounds, As the halogen atom, a chlorine atom, a bromine atom or an iodine atom is preferably used. Particularly preferred organic halogen compounds among the above are 1-
(2-acryloyloxyethoxy) ethyl chloride and 1- (2-methacryloyloxyethoxy) ethyl chloride.

The above organic halogen compounds are, for example, 2-
A vinyl compound such as vinyloxyethyl acrylate or 2-vinyloxyethyl methacrylate and a hydrogen halide such as hydrogen chloride, hydrogen bromide or hydrogen iodide are subjected to an equimolar reaction at a low temperature of about −78 to 0 ° C. , Can be synthesized by reacting.

On the other hand, as a metal halide having Lewis acidity (hereinafter simply referred to as a metal halide) used together with an organic halogen compound, tin tetrachloride (SnC) is used.
l ₄ ), tin tetrabromide (SnBr ₄ ), boron trifluoride (BF ₃ ), aluminum trichloride (AlCl ₃ ), aluminum tribromide (AlBr ₃ ), zinc dichloride (ZnCl)
₂ ), antimony pentachloride (SbCl ₅ ), iron trichloride (F
eCl ₃ ), titanium tetrachloride (TiCl ₄ ), titanium tetrabromide (TiBr ₄ ), rhenium pentachloride (ReCl ₅ ), diethyl aluminum monochloride (AlEt ₂ Cl)
And monoethyl aluminum dichloride (AlEt
Cl ₂ ), etc., among which tin tetrachloride (SnCl ₄ ) and tin tetrabromide (SnBr) are preferred.
₄ ), and more preferably tin tetrabromide (SnB)
r ₄ ). When this tin tetrabromide (SnBr ₄ ) is used, the polymerization proceeds at an appropriate rate, and a poly α-methylstyrene type macromonomer having a particularly narrow molecular weight distribution can be obtained.

The above-mentioned organic halogen compound and metal halide are preferably used in an amount of 0.1 to 10 mol, and more preferably 0.5 to 4 mol of metal halide per mol of the organic halogen compound. As a method of adding the organic halogen compound and the metal halide to the polymerization system, α-
A method of adding an organic halogen compound and then adding a metal halide to a solution in which methylstyrene is dissolved in a polymerization solvent to be described later is preferable, and the polymerization is started immediately when the metal halide is added.

The amount of the above-mentioned polymerization initiator to be used is selected according to the molecular weight of the desired poly α-methylstyrene type macromonomer. For example, in the case of producing a macromonomer having a number average molecular weight of 1200, Is 0.1 mol per 1 mol of α-methylstyrene monomer, and the number average molecular weight is 590.
For the purpose of producing a macromonomer of 00, α
-It is preferable to use the organic halogen compound in a ratio of 0.002 mol per mol of the methylstyrene monomer.

Examples of the solvent used for the polymerization include methylene chloride, chloroform, carbon tetrachloride, ethylene dichloride, benzene, toluene, nitromethane and nitrobenzene, and more preferably methylene chloride. The preferred solution concentration of the α-methylstyrene monomer in the polymerization is about 5 to 30% by weight, and the polymerization temperature is preferably about −78 to 0 ° C. Under the above conditions, the polymerization reaction is usually completed in about 10 to 30 minutes. The ethylenically unsaturated bond introduced at one end of the obtained polymer can be confirmed by measuring a nuclear magnetic resonance spectrum (NMR).

[0018]

The method for producing a poly-α-methylstyrene type macromonomer of the present invention is characterized in that a specific organic halogen compound represented by the general formula of the above Chemical Formula 2 and Lewis acid are used as a polymerization initiator for α-methylstyrene. By using a metal halide having a living cationic polymerization to polymerize α-methylstyrene using the group —CHX— located at the α-position of the oxygen atom in the general formula of Chemical Formula 2 as a polymerization initiation point. Occurs, and the substituent Y undergoes almost no chemical change during the polymerization. As a result, it is possible to obtain a poly α-methylstyrene type macromonomer having an ethylenically unsaturated group derived from the substituent Y on the polymerization initiation side.

According to the production method of the present invention, poly α-methyl styrene having a narrow molecular weight distribution can be obtained without the need for a particularly high degree of purification operation for the α-methyl styrene monomer and the solvent and by the ordinary polymerization operation. The type macromonomer can be easily produced.

[0020]

EXAMPLES Hereinafter, the method for producing the poly .alpha.-methylstyrene type macromonomer of the present invention will be described more specifically by way of examples.

Example 1 All the following operations were performed in a dry nitrogen atmosphere, and the reagents were sampled and added by a syringe. In 50 ml of a 1.0 M n-hexane solution of vinyloxyethyl acrylate,
Blow hydrogen chloride gas for 30 minutes at a temperature of 0 ° C, and 1.0M
A concentrated 1- (2-acryloyloxyethoxy) ethyl chloride solution was quantitatively synthesized. 0.33 ml of α-methylstyrene, 0.10 ml of tetralin (used as an internal standard substance for gas chromatography) and 3.57 ml of methylene chloride were sampled in a Schlenk tube, uniformly mixed, and then cooled to a temperature of −78 ° C. In the resulting solution,
0.5 ml of a 0.1 M n-hexane solution of 1- (2-acryloyloxyethoxy) ethyl chloride prepared in advance was added, and subsequently prepared separately, and tin tetrabromide cooled to a temperature of −78 ° C. Polymerization was initiated by adding 0.5 ml of 0.1 M methylene chloride solution.

After polymerizing for 42 seconds at a temperature of -78 ° C.,
2 ml of methanol cooled in advance to a temperature of −78 ° C. was added to the polymerization system to terminate the polymerization. When the unreacted α-methylstyrene in the reaction solution was measured by gas chromatography using the above-mentioned tetralin previously added to the polymerization system as an internal standard substance, it was found that the polymerization conversion rate of the monomer was 28%. It was Then, the reaction solution is diluted with toluene, diluted hydrochloric acid, water, diluted sodium hydroxide solution,
Washed with water in sequence. The solvent in the obtained polymer solution was distilled off under reduced pressure to isolate the macromonomer.

The thus obtained macromonomer was subjected to measurement by gel permeation chromatography and each magnetic resonance spectrum to obtain a number average molecular weight (M
n), the weight average molecular weight (Mw), and the amount of acryloyloxy groups introduced at the terminal were determined. As a result, the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the obtained macromonomer were 3400 and 3870, respectively.
And the dispersity (Mw / Mn) was 1.14. The introduction rate of acryloyloxy groups was 84 mol% (average of 0.84 introductions per polymer molecule).

[0024]

Industrial Applicability The method for producing a poly-α-methylstyrene type macromonomer of the present invention uses a polymerization initiator composed of a specific organic halogen compound and a metal halide having Lewis acidity to produce α-methylstyrene. By polymerizing, a poly α-methylstyrene type macromonomer having a narrow molecular weight distribution can be easily produced without requiring a particularly sophisticated purification operation for the monomer and the solvent. By copolymerizing this macromonomer with another radically polymerizable monomer, a graft copolymer suitable for various uses such as paints, adhesives and molding materials can be obtained.

Claims (1)

[Claims] 1. An organic halogen compound represented by the following general formula (1) (wherein X is a halogen atom and Y is a substituent having an ethylenically unsaturated bond) as a polymerization initiator: A method for producing a poly-α-methylstyrene type macromonomer, which comprises subjecting α-methylstyrene to living cationic polymerization using a metal halide having Lewis acidity. Embedded image CH ₃ —CHX—O—CH ₂ CH ₂ —Y