JP2967959B2 - Method for polymerizing α-cyclopropylstyrene compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymerization method characterized by polymerizing an .alpha.-cyclopropylstyrene compound using a radical polymerization initiator. Α- in the present invention
Cyclopropylstyrene compounds exhibit low volume shrinkage during ring-opening isomerization polymerization and are useful as raw materials for molding materials, composite materials, casting materials, sealing materials, medical materials, dental materials, paints and adhesives. . The polymerization method of the α-cyclopropylstyrene compound of the present invention is a useful polymerization method that can be suitably performed in the above-mentioned field.

[0002]

2. Description of the Related Art A part of the α-cyclopropylstyrene compound represented by a specific general formula in the present invention is known, for example, a polymer having the following structure by cationic polymerization using aluminum bromide as a polymerization initiator. (Journalof Polymer)
Science A-1, Vol. 5, p. 227 (1967)
Year)). The report only describes the ¹ H-NMR spectrum and molecular weight of the obtained polymer, does not suggest that the compound undergoes radical polymerization at all, and does not describe any volume change during polymerization. Absent.

[0003]

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[0004]

The polymerization of an α-cyclopropylstyrene compound by cationic polymerization using a Lewis acid-based cationic polymerization initiator such as aluminum bromide is difficult to handle because the Lewis acid is usually a strong acid. The influence of water on the polymer was great, and there were problems such as coloring of the obtained polymer, corrosiveness and toxicity of acid components remaining in the polymer. The polymer obtained when the compound was cationically polymerized was a copolymer of not only the ring-opening polymer unit A but also a vinyl polymer unit B and a polymer unit C having a cyclobutane structure, as shown in Chemical formula 2. . The formation of the ring-opening polymerization unit A contributes to a reduction in volume shrinkage during the polymerization as in the case of ordinary ring-opening polymerization, but the generation of the vinyl polymerization unit B and the polymerization unit C having a cyclobutane structure does not involve ring opening. Therefore, it does not contribute to a reduction in polymerization shrinkage. For this reason, the polymerization shrinkage upon cationic polymerization of the α-cyclopropylstyrene compound is usually as large as 12 to 15%, depending on the molecular weight.

[0005]

Means for Solving the Problems The present inventors have found that an α-cyclopropylstyrene compound is selectively subjected to ring-opening polymerization by a radical polymerization initiator, and only the ring-opening polymerization unit A of the polymer represented by the formula (2) is used. In this case, it was found that the volume shrinkage was about 7 to 10%, which was smaller than that of the cationic polymerization, and the present invention was completed.

That is, the present invention provides the following

[0007]

Embedded image (Wherein, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R
^9, R ^10, R ¹¹ and R ^{1 2} are each hydrogen atom, a lower alkyl group, an alkoxy group, a halogen group, a nitro group, a cyano group, an amino group, amido group, hydroxyl group or alkyl ester group having 20 or less carbon atoms . ), Wherein the α-cyclopropylstyrene compound is polymerized using a radical polymerization initiator.

In the above formula 3, R ¹ , R ² , R ³ , R ⁴ ,
As the lower alkyl group represented by R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ and R ¹² , an alkyl group having 8 or less carbon atoms, for example, a methyl group, an ethyl group, an n-propyl Group, i-propyl group, n-butyl group, i-butyl group, t
-Butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and the like. Examples of the alkoxy group include a methyloxy group, an ethyloxy group and an n-
A propyloxy group, an i-propyloxy group, an n-butyloxy group, an n-pentyloxy group, and the like, and examples of the halogen group include a chloro group, a bromo group, and the like.
Examples of the amino group include an N-methylamino group, N, N-
Examples of the amide group include an aminocarbonyl group and a formylamino group.Examples of the alkyl ester group having 20 or less carbon atoms include a methoxycarbonyl group, an ethoxycarbonyl group, and an acetyloxy group. No.

Preferred examples of the α-cyclopropylstyrene compound in the present invention include the following compounds.

[0010]

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The α-cyclopropylstyrene compound in the present invention may be used not only as one kind of compound but also as a mixture of two or more kinds of compounds.

The α-cyclopropylstyrene compound in the present invention may be used as a mixture with another polymerizable monomer. The other polymerizable monomer may be one having radical polymerizability, and preferred examples include styrene, acrylic acid, methacrylic acid, methyl methacrylate, ethyl acrylate, acrylonitrile, acrylamide, vinyl chloride, vinyl acetate and the like.

The method for producing the α-cyclopropylstyrene compound represented by the above formula (3) is not particularly limited, and a known method (Journal of Organic Chem) is used.
Istry, Vol. 30, p. 942 (1965)) can be used.

Examples of the radical polymerization initiator used in the present invention include azobis-based polymerization initiators such as azobisisobutyronitrile, methyl azobisisobutyrate, azobis-2,4-dimethylvaleronitrile and azobiscyclohexanecarbonitrile; Peroxydicarbonate, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, benzoyl peroxide, cyclohexanone peroxide, t-butyl perbenzoate, dicumyl peroxide, di-t-butyl peroxide, p-menthane hydroperoxide, pinane hydroperoxide, Examples include peroxide-based polymerization initiators such as cumene hydroperoxide and t-butyl hydroperoxide.

Benzophenone, Michler's ketone,
Aromatic ketones such as xanthone, thioxanthone, 2-chlorothioxanthone and 2-ethylanthraquinone; acetophenone, trichloroacetophenone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-2
-Methyl-4'-isopropylpropiophenone, 1-
Ultraviolet radical polymerization using an initiator such as acetophenones such as hydroxycyclohexyl phenyl ketone, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-diethoxyacetophenone, and 2,2-dimethoxy-2-phenyl-acetophenone benzyl dimethyl ketal; , Norcan furquinone / N, N-
Visible light radical polymerization using an α-diketone / amine initiator such as dimethylaminoethyl methacrylate, camphorquinone / N, N-dimethylaminoethyl methacrylate, camphorquinone / ethyl p-N, N-dimethylaminobenzoate is also used. Is done.

The polymerization initiator is used in an amount of 0.01 to 10 mol%, preferably 0.05 to 3 mol%, based on the α-cyclopropylstyrene compound represented by the formula (3).

The temperature of the polymerization reaction varies depending on the type of polymerization initiator used, but is selected from the range of room temperature to 200 ° C., preferably 50 to 180 ° C.

The polymerization reaction can be carried out under any pressure from reduced pressure to increased pressure, but is preferably carried out at normal pressure.

The polymerization reaction may be carried out in the absence of a solvent, but may be benzene, toluene, xylene, hemimelitene,
Aromatic hydrocarbons such as pseudocumene and mesitylene; aliphatic hydrocarbons such as hexane, heptane and octane; alicyclic hydrocarbons such as cyclohexane and cyclooctane;
Methylene chloride, chloroform, tetrachloroethylene,
The reaction may be performed in the presence of a solvent such as a halogenated hydrocarbon such as chlorobenzene, dichlorobenzene, and trichlorobenzene.

The polymerization reaction time is usually selected from the range of 1 to 100 hours. After reaching the desired degree of polymerization, the polymer obtained is isolated and purified by known methods.

[0021]

EXAMPLES The present invention will be described more specifically with reference to the following examples. In addition, the physical property value was measured by the following method. ¹ H-NMR: JMX PMX60 _SI (measurement frequency; 60 MHz) IR: JASCO Fourier transform infrared spectrophotometer FT
/ IR-3 type number average molecular weight: Tosoh GPC-8000 system (polystyrene gel column; TSK gel G5000HXL,
G4000HXL, G2500HXL, mobile phase solvent; T
HF, flow rate: 1.0 mL / min, detector: RI, converted to polystyrene) Density: Density gradient tube method specific gravity measurement device A type manufactured by Shibayama Scientific Instruments Co., Ltd. (Measurement temperature; 25 ° C)

Example 1 433 mg of α-cyclopropylstyrene and di-t-
13.2 mg of butyl peroxide was charged into a glass container, degassed, sealed, and heated at 130 ° C. for 20 hours. The reaction mixture was diluted with methylene chloride and then re-precipitated in methanol to obtain 150 mg of a colorless transparent viscous liquid. The number average molecular weight of the product was 1380.

¹ H-NMR spectrum (the result is shown in FIG.
Measurement solvent; heavy chloroform Internal standard substance; tetramethylsilane

[0024]

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[0025]

[Table 1]

IR spectrum (the results are attached as FIG. 2) From these results, it was confirmed that the product was a polymer having a structure comprising a repeating unit represented by the following chemical formula 6.

[0027]

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The density of the polymer was measured.
040, and the volumetric shrinkage calculated from the monomer density was 8.6%.

Example 2 In Example 1, di-t-butyl peroxide was used.
Azobisisobutyronitrile 14.8m instead of 2mg
g, and polymerization was carried out in the same manner as in Example 1 except that the polymerization temperature was changed to 120 ° C. and 60 ° C. to obtain 94 mg of a colorless and transparent viscous liquid. The number average molecular weight of the product is 36
It was 10. From the ¹ H-NMR spectrum and IR spectrum, the product was confirmed to be a polymer having the same structure as the polymer obtained in Example 1.

Example 3 In Example 1, α-cyclopropylstyrene 433 was used.
Polymerization was carried out in the same manner as in Example 1 except that 523 mg of 4-methoxy-α-cyclopropylstyrene was used instead of mg to obtain 160 mg of a colorless and transparent viscous liquid. The number average molecular weight of the product was 1440. The product is 1
From the 1 H-NMR spectrum and the IR spectrum, it was confirmed that the polymer had a structure comprising a repeating unit represented by the following chemical formula (7).

[0031]

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The density of the polymer was measured.
083, and the volumetric shrinkage calculated from the monomer density was 7.2%.

Example 4 The procedure of Example 1 was repeated except that α-cyclopropylstyrene 433 was used.
Polymerization was carried out in the same manner as in Example 1 except that 104 mg of styrene was added to 100 mg of styrene.
9 mg were obtained. The number average molecular weight of the product was 3520. From the ¹ H-NMR spectrum and the IR spectrum, the product was confirmed to be a polymer having a structure comprising a repeating unit represented by the following formula (8).

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The density of the polymer was measured.
060, and the volumetric shrinkage calculated from the monomer density was 9.9%.

Comparative Example 1 In Example 1, α-cyclopropylstyrene 433
Polymerization was carried out in the same manner as in Example 1 except that 312 mg of styrene was used instead of mg to obtain polystyrene. The volume shrinkage calculated from the monomer density was 14.7%.

Comparative Example 2 In Example 1, di-tert-butyl peroxide 13.2
12.8 mg of boron trifluoride ether complex instead of mg
Polymerization was carried out in the same manner as in Example 1 except for using, to obtain a polymer. The volume shrinkage calculated from the density of the monomer was 13.0%.

[0037]

According to the method of the present invention, there is provided a method for polymerizing an α-cyclopropylstyrene compound using a radical polymerization initiator.

[Brief description of the drawings]

FIG. 1 is a diagram showing a ¹ H-NMR spectrum of one example of a compound polymerized by a polymerization method according to the present invention.

FIG. 2 is a view showing an IR spectrum of one example of a compound polymerized by the polymerization method according to the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (56) References A. D. KETREY, A. J. BE RLIN, L.A. P. FISHER, Journal of Polymer Science: part A-1, p. 227-230 (1967) (58) Fields investigated (Int. Cl. ⁶ , DB name) C08G 61/00-61/12 CA (STN) REGISTRY (STN)

Claims (1)

(57) [Claims] 1. The following chemical formula 1 (Wherein, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R
^9, R ^10, R ¹¹ and R ^{1 2} are each hydrogen atom, a lower alkyl group, an alkoxy group, a halogen group, a nitro group, a cyano group, an amino group, amido group, hydroxyl group or alkyl ester group having 20 or less carbon atoms . ), Wherein the α-cyclopropylstyrene compound is polymerized using a radical polymerization initiator.