JPH08319322A - Chloroprene copolymer - Google Patents

Abstract

PURPOSE: To obtain a chloroprene copolymer composed of chloroprene monomer and maleimide monomer, having excellent crystallization resistance, heat- resistance, rigidity, adhesion, etc., and exhibiting bactericidal property, fungicidal property, etc. CONSTITUTION: This chloroprene copolymer contains (A) the bonding unit of formula I and (B) the bonding unit of formula II (R is H, a 1-15C alkyl, a cycloalkyl or an aryl, preferably cyclohexyl, phenyl, chlorophenyl, methylphenyl, dimethylphenyl, ethylphenyl, dimethylphenyl or lauryl) and satisfies the formulas M/N=4999/1 to 1/4999 and M+N =10 to 50 wherein M and N are degrees of polymerization of the components A and B, respectively. The copolymer is preferably synthesized by solution polymerization or emulsion polymerization method.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a copolymer of a chloroprene monomer and a maleimide monomer. More specifically, it has excellent crystal resistance, heat resistance, high rigidity, adhesiveness, etc.
Further, the present invention relates to a novel copolymer composed of a chloroprene monomer and a maleimide monomer, which has bactericidal properties and antifungal properties not found in conventional chloroprene rubber.

[0002]

2. Description of the Related Art Chloroprene polymers are used in a wide range of fields such as automobile parts, adhesives and various industrial parts by utilizing their balanced properties. Further, maleimides are known to be effective in improving the heat resistance of thermoplastic resins (JP-A-59-11322, etc.).

On the other hand, various attempts have been made to improve the properties of chloroprene polymers, and for example, various chloroprene copolymers obtained by copolymerizing a comonomer component have been proposed. Examples of the comonomer include sulfur, 2,3-dichloro-1,3-butadiene, 1-chloro-1,3-butadiene, styrene, acrylonitrile, methacrylonitrile, isoprene, butadiene, methacrylic acid and esters thereof. Known (Rubber Chemist
ry and Technology, 49,670 (1976)). Also known is a method of improving the properties by grafting a comonomer to a chloroprene polymer (Japanese Patent Publication No. 36-8445).
JP-B-43-6067, JP-A-62-106913, etc.).

[0004]

However, even with the chloroprene copolymers produced by various methods as described above, there are many cases in which the improvement of the properties is still insufficient. Further, the chloroprene monomer has a very high polymerization rate as compared with the comonomer, and the types of comonomer which can be copolymerized were limited in practical use. Further, among the comonomers to be copolymerized, the comonomer excluding sulfur and 2,3-dichloro-1,3-butadiene has a lower copolymerizability as compared with the chloroprene monomer, and thus is difficult to be incorporated into the molecule, and thus the characteristics are naturally obtained. There was a limit to the improvement. As a result of researching a method for improving the properties of a chloroprene polymer, the present inventors have succeeded in synthesizing a novel copolymer of a chloroprene monomer and a maleimide monomer, and reached the present invention. did.

[0005]

Means for Solving the Problems That is, the present invention has a bonding unit represented by the following chemical formulas (1) and (2) in the molecule, and the degree of polymerization of the chemical formula (1) is M and the chemical formula is (2)
When the polymerization degree of N is N, the ratio of M / N is 4999/1.
˜1 / 4999, and M + N is 10 or more and 5000 or less, and relates to a chloroprene copolymer. Chemical formula (1)

Embedded image Chemical formula (2)

[Chemical 4] (However, R in the chemical formula (2) is hydrogen and has 1 to 15 carbon atoms.
An alkyl group, a cycloalkyl group, an aryl group or a substituted aryl group). The present invention also relates to the chloroprene copolymer in which R is any one of a cyclohexyl group, a phenyl group, a chlorophenyl group, a methylphenyl group, a dimethylphenyl group, an ethylphenyl group, a diethylphenyl group and a lauryl group.

The present invention will be described in detail below. In the present invention, a chloroprene monomer alone or a mixture with a comonomer (hereinafter, often referred to as chloroprene-based monomer) is used. Examples of the comonomer include sulfur, 2,3-dichloro-1,3-butadiene, 1-chloro-1,3-butadiene, styrene, acrylonitrile, methacrylonitrile, isoprene, butadiene, methacrylic acid and esters thereof. Is. These can be used within a range that does not impair the properties of chloroprene.

The maleimide monomer used in the present invention is represented by the following general formula (3). General formula (3)

Embedded image (However, R is hydrogen, an alkyl group having 1 to 15 carbon atoms, a cycloalkyl group, an aryl group, or a substituted aryl group). The maleimide monomer is not particularly limited as long as it satisfies the formula (3). For example, maleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-butylmaleimide,
N-cyclohexylmaleimide, N-laurylmaleimide, N-phenylmaleimide, N-chlorophenylmaleimide, N-bromophenylmaleimide, N-methylphenylmaleimide, N-ethylphenylmaleimide, N
-Dimethylphenylmaleimide, N-diethylphenylmaleimide, N-nitrophenylmaleimide, N-hydroxyphenylmaleimide, N-methoxyphenylmaleimide, N-ethoxyphenylmaleimide, N-carboxyphenylmaleimide and the like can be mentioned. Among these,
From the viewpoint of economical efficiency, the maleimide unit wherein R in the formula (3) is any one of a cyclohexyl group, a phenyl group, a chlorophenyl group, a methylphenyl group, a dimethylphenyl group, an ethylphenyl group, a diethylphenyl group and a lauryl group. A monomer is preferable, and it is used as one kind or a mixture of two or more kinds (hereinafter, often referred to as maleimide-based monomer).

The copolymer according to the present invention can be synthesized by a well-known polymerization method such as solution polymerization, emulsion polymerization and bulk polymerization. From the viewpoint of heat removal during polymerization and temperature control, solution polymerization or emulsion polymerization is preferred. .

In the case of solution polymerization, for example, toluene, benzene, xylene, acetone, tetrahydrofuran, dimethylsulfoxide, dimethylformamide, etc., which are common solvents for the chloroprene-based monomer and the maleimide-based monomer, are prepared and the chloroprene-based monomer is prepared. A monomer and a maleimide-based monomer are separately dissolved in a solvent, or a maleimide-based monomer is previously dissolved in a chloroprene-based monomer and then dissolved in a solvent, and a polymerization reaction is started with a known radical initiator. be able to. The polymerization initiator is not particularly limited as long as it is a compound that generates a free radical at the polymerization temperature, and examples thereof include azobis (4-methoxy-2,4-dimethylvaleronitrile) and azobis (2,4-dimethylvaleronitrile). Azo compounds, organic peroxides such as di-n-propylperoxydicarbonate and lauroyl peroxide.

In the case of emulsion polymerization, it is desirable to dissolve and disperse the maleimide-based monomer in the chloroprene-based monomer in advance in order to avoid poor dispersion of the maleimide-based monomer before the polymerization. Examples of the emulsifier include alkali metal salts and ammonium salts such as higher alcohol sulfuric acid ester, higher alkyl ether sulfuric acid ester, alkylphenyl ether sulfuric acid ester, and sulfated fatty acid ester, alkali metal salt of alkylbenzenesulfonic acid, disproportionated rosin acid, and unmodified. An alkali metal salt of rosin acid, an alkali metal salt of formalin condensate of β-naphthalene sulfonic acid, polyoxyethylene alkyl ether and the like are used. Among these, sodium lauryl sulfate and sodium dodecylbenzene sulfonate are preferably used. As the chain transfer agent, alkyl mercaptan, dialkyl xanthogen disulfide and the like are used. As the polymerization initiator, potassium persulfate, benzoyl peroxide and the like used in ordinary radical polymerization are used. Further, in order to avoid hydrolysis of the maleimide monomer during polymerization, the system pH should be 7 or less,
Polymerization is preferably carried out by controlling the amount to 5 or less.

Next, in the present invention, it is important that M + N is 10 or more and 5000 or less, where M is the degree of polymerization of the chemical formula (1) and N is the degree of polymerization of the chemical formula (2). , M + N is in the range of 10 to 5000, the polymer can be a practically useful polymer.

The polymerization temperature is not particularly limited, but it is generally 0 to 60 ° C., preferably 10 to 60 ° C.
50 ° C.

From a practical point of view, the polymerization rate is preferably 50% or more. When the predetermined polymerization rate is reached, the reaction solution is cooled, and a small amount of a polymerization inhibitor is added to stop the reaction. As the polymerization inhibitor, known radical polymerization inhibitors such as thiodiphenylamine, 4-tert-butylcatechol, diethylhydroxylamine and the like are used. In the case of solution polymerization, after the reaction is stopped, if necessary, concentration adjustment operations such as desolventization and post-solvent addition can be performed, and further, a thickener, a plasticizer, etc. within a range that does not impair the excellent properties of the present invention. Can be added. Isolation of the copolymer in the emulsion polymerization is carried out by adopting the well-known freeze coagulation-water washing method.

[0014]

EXAMPLES The following will specifically describe the method for producing the copolymer of the present invention with reference to Examples, but the present invention is not limited thereto.

Examples 1 to 3 Maleimide monomers were added to the predetermined amount of chloroprene monomers shown in Table 1, and dispersed and dissolved with a magnetic stirrer at room temperature. Next, after pouring the solvent and the above-mentioned monomer mixture shown in Table 1 into a pressure-resistant glass-made polymerization vessel having an internal volume of 1 liter equipped with a SUS pipe, a valve and the like, and repeating vacuum and dry nitrogen gas charging twice, The nitrogen atmosphere was maintained by applying a nitrogen gas pressure of 1 kg / cm 2. After stirring the charging liquid and adjusting the temperature, the initiator azobis (2,4-dimethylvaleronitrile) 30 dissolved in toluene so as to have a concentration of 10% by weight in advance 30
cc was intermittently pressed and dropped with nitrogen gas from another pipe attached to the polymerization vessel to start the polymerization reaction. The residual amount of the monomer in the reaction solution was sequentially analyzed by gas chromatography to trace the monomer conversion rate during the polymerization. When the conversion rate reached a predetermined value, the reaction solution was cooled, and the toluene solution of the polymerization inhibitor thiodiphenylamine was added at 50 ppm with respect to the total amount of the charged monomers to stop the reaction. Thus, a copolymer according to the present invention (hereinafter referred to as a polymer) was obtained.

Next, the above polymer was purified with benzene and methanol, a part of the purified polymer was dissolved in deuterated chloroform, and the molecular structure and binding state were analyzed by ¹ H nuclear magnetic resonance spectrum and ¹³ C nuclear magnetic resonance spectrum. Identified. on the other hand,
Apply a part of the purified polymer to a KRS plate, dry it,
The infrared absorption spectrum of the polymer was measured. The degree of polymerization of the polymer was calculated from the measurement result of gel permeation chromatography.

Examples 4 to 5 Maleimide-type monomers were added to a predetermined amount of chloroprene-type monomers shown in Table 2, and dispersed and dissolved at room temperature. On the other hand, a soap solution for polymerization was prepared separately. A mixture of the above soap solution and a chloroprene-based monomer and a maleimide-based monomer was added to a 3-liter 4-neck separable flask, and the mixture was stirred and emulsified. The polymerization was carried out under a nitrogen atmosphere at a polymerization temperature of 30 ° C. while intermittently dropping an aqueous solution of potassium persulfate. The progress of the polymerization reaction was followed by measuring the specific gravity. Conversion of monomer is 8
When it reached 0%, thiodiphenylamine was added as a polymerization inhibitor in an amount of 100 ppm per the amount of the produced polymer to terminate the polymerization. Unreacted monomers contained in the polymer latex were removed under reduced pressure to obtain a polymer. A part of the latex was purified with benzene and methanol, and the structure of the polymer was identified by infrared absorption spectrum. The degree of polymerization was calculated from the result of gel permeation chromatography measurement.

[0018]

[Table 1]

[0019]

[Table 2]

Here, as the chloroprene monomer and the 2,3-dichloro-1,3-butadiene monomer, monomers manufactured by Denki Kagaku Kogyo Co., Ltd. were used. As the N-cyclohexylmaleimide monomer, a monomer manufactured by NOF CORPORATION was used, and as the N-phenylmaleimide monomer, a monomer manufactured by Nippon Shokubai Co., Ltd. was used.

400 MH of the copolymer obtained in Example 1
With respect to the ¹ H nuclear magnetic resonance spectrum of z (FIG. 1), the attributions relating to the main components are shown in Table 3 and chemical formula (4).

[0022]

[Table 3]

Chemical formula (4)

[Chemical 6]

Similarly, 40% of the copolymer obtained in Example 1 was used.
With respect to the ¹³ C nuclear magnetic resonance spectrum at 0 MHz (FIG. 2), the attributions relating to the main components are shown in Table 4 and chemical formula (5).

[0025]

[Table 4]

Chemical formula (5)

[Chemical 7]

Table 5 shows the attributions of the main components of the Fourier infrared absorption spectrum (FIG. 3) of the copolymer obtained in Example 1.

[0028]

[Table 5]

400 MH of the copolymer obtained in Example 2
With respect to the ¹ H nuclear magnetic resonance spectrum of z (FIG. 4), the attributions relating to the main components are shown in Table 6 and chemical formula (6).

[0030]

[Table 6]

Chemical formula (6)

Embedded image

Table 7 shows the attributions of the main components in the Fourier-infrared absorption spectrum (FIG. 5) of the copolymer obtained in Example 2.

[0033]

[Table 7]

Table 8 shows the attributions of the main components in the Fourier-infrared absorption spectrum (FIG. 6) of the copolymer obtained in Example 4.

[0035]

[Table 8]

[0036]

INDUSTRIAL APPLICABILITY The chloroprene copolymer according to the present invention is a copolymer which can be expected to have excellent properties such as crystal resistance, heat resistance, high rigidity, adhesiveness, bactericidal property and mildew resistance due to its molecular structure. Therefore, it can be expected that the copolymer itself will be used as an industrial part or product, and also as a modifier of chloroprene rubber.

[Brief description of drawings]

FIG. 1 shows the copolymer obtained in Example 1 at 400 MHz.
^{It is a 1} H nuclear magnetic resonance spectrum.

2 is a graph of 400 MHz of the copolymer obtained in Example 1. FIG.
^{It is a 13} C nuclear magnetic resonance spectrum.

3 is a Fourier infrared absorption spectrum of the copolymer obtained in Example 1. FIG.

FIG. 4 shows the copolymer obtained in Example 2 at 400 MHz.
^{It is a 1} H nuclear magnetic resonance spectrum.

5 is a Fourier infrared absorption spectrum of the copolymer obtained in Example 2. FIG.

6 is a Fourier infrared absorption spectrum of the copolymer obtained in Example 4. FIG.

Claims (2)

[Claims] 1. A molecule has a bonding unit represented by the following chemical formulas (1) and (2), and the degree of polymerization of the chemical formula (1) is M and the degree of polymerization of the chemical formula (2) is N. Sometimes M / N
Is 4999/1 to 1/4999, and M + N is 10 or more and 5,000 or less. Chemical formula (1) Chemical formula (2) (However, R in the chemical formula (2) is hydrogen and has 1 to 15 carbon atoms.
Is an alkyl group, a cycloalkyl group, an aryl group or a substituted aryl group) 2. The chloroprene copolymer according to claim 1, wherein R is any one of a cyclohexyl group, a phenyl group, a chlorophenyl group, a methylphenyl group, a dimethylphenyl group, an ethylphenyl group, a diethylphenyl group and a lauryl group.