JP2000143741A - New copolymer and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a copolymer having low hygroscopic property and low dielectric characteristics excellent in heat resistance and mechanical properties and useful as a functional material such as an electrical insulating material for electronic parts by constituting the polymer so as to have a specific structure. SOLUTION: This copolymer has a structure of the formula [X, Y and Z are each a 3-8C branched alkyl, a substituted branched alkyl, a 4-8C cycloalkyl or a substituted cycloalkyl; (m) is >=30; (n) is >=10] and preferably has 15,000-60,000 weight average molecular weight and random structure. The copolymer is formed from a fumarate diester of the formula XOOC-CH=CH-COOY and an electron-donating monomer having <=-0.2 e value in Q and e theory of Alfrey-Price [which is a parameter exhibiting degrees of resonance (Q value) of double bond part and polarity (e value) of a polymerizable monomer using styrene as a standard (Q is 1.0 and e is -0.8)].

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used as a functional material such as an electrical insulating material for electronic parts, and has a low hygroscopic property and a low hygroscopicity formed from a fumarate diester having a bulky substituent and an alkyl vinyl ether. The present invention relates to a novel copolymer having excellent dielectric properties and a method for producing the same.

[0002]

2. Description of the Related Art Fumarate diesters (DRFs) have been reported not to undergo radical homopolymerization, but Otsu et al. Reported that almost all DRFs show homopolymerizability [T.
Otsu, et al, Polym. Bull., 12, 449 (1984)]
In particular, it has been clarified that the reactivity of a DRF having a branched alkyl group is higher than that of a DRF having a straight-chain alkyl group [T. Otsu et al, Macromol. Sci-Chem., A25, 5
37 (1988)].

Among various DRFs, homopolymers having relatively high radical homopolymerizability of diisopropyl fumarate (DiPF) and dicyclohexyl fumarate (DcHF) and having a molecular weight of about 100,000 under ordinary radical polymerization conditions are easily obtained. The resulting polymer does not soften even at 200 ° C. or higher, exhibits higher heat resistance than general thermoplastic vinyl polymers, and is a resin having a low hygroscopic property and a low dielectric constant. On the other hand, since the mechanical strength of these polymers is lower than that of other polymers, studies have been made for the purpose of modifying a thermoplastic resin by utilizing the heat resistance of the polymer (Japanese Patent Application Laid-Open (JP-A) No. 2002-110630). Showa 62
-169807).

[0004] Further, as can be easily understood from the structure, DRF is a monomer having a strong electron-accepting property. Therefore, DRF can be used together with a polar monomer such as (meth) acrylate or acrylonitrile. Although the polymerization reactivity is low, the copolymerizability with an electron-donating monomer such as styrene, vinyl ester, and vinyl ether is relatively high, and copolymerization with such a monomer is being studied.

On the other hand, alkyl vinyl ethers are also monomers having very poor radical homopolymerizability, but have high copolymerization reactivity with an electron-accepting monomer such as maleic anhydride, and are therefore useful. It is used in various fields as a radical copolymerizable monomer. For example, a copolymer of maleic anhydride and methyl vinyl ether is known as a water-soluble polymer like polyacrylic acid and polyvinylpyrrolidone, and is a highly useful material.

Recently, Lapin. SC et al and De
cker et al. reported on photo- [ultraviolet (UV)] polymerization of linear dialkyl fumarate and linear alkyl vinyl ether (Lapin. SC, Radtech. Asia, '93, Tokyo,
Japan, 1993, 149, Decker, C., Acta. Pokymer, 45, 33
3 (1994)), showing that it has the same polymerization reactivity as a (meth) acrylic monomer, and states that it can be used as a UV resist.

[0007]

However, even in the case of DiPF or DcHF having relatively high polymerization reactivity in DRF, for example, styrene, (meth) acrylates,
When acryloniloryl, vinyl acetate and the like are compared with their radical homopolymerizability, the reactivity is considerably poor. Moreover, since these DRFs do not have thermal polymerizability (non-catalytic polymerizability), the polymerization conversion limit is at most about 90%. Therefore, when these DRFs are applied to a photocuring system using ultraviolet rays or electron beams, not only the polymerization reaction rate and the polymerization conversion rate but also the mechanical properties of the cured product are higher than those of (meth) acrylates. There is a problem that the performance is inferior.

In the copolymerization with vinyl esters and vinyl ethers, the problems concerning polymerization are considerably improved, but the mechanical properties and thermal properties of the obtained polymer are not so distinctive, and the development of applications has been advanced. There is no reality.

For this reason, the fumarate diester is almost completely polymerized at a high polymerization conversion without impairing the heat resistance, low moisture absorption and low dielectric constant characteristics, which are the characteristics of the fumarate diester polymer, and the mechanical properties of the polyfumarate are low. There is a demand for a copolymer which can improve the mechanical strength and is useful as a functional material.

The present invention has been made by focusing on the problems existing in the above prior art. It is an object of the present invention to provide a novel copolymer which is excellent in low moisture absorption, low dielectric properties, heat resistance and mechanical properties and is useful as a functional material. Another object is to provide a method for producing a copolymer having excellent polymerization reaction rate and polymerization conversion rate.

[0011]

Means for Solving the Problems The first invention of the present invention is a copolymer represented by the following general formula (1).

[0012]

Embedded image

(Where X in the formula is a branched alkyl group having 3 to 8 carbon atoms or a substituted branched alkyl group;
8 represents a cycloalkyl group or a substituted cycloalkyl group, and Y represents a branched alkyl group or a substituted branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group or a substituted cycloalkyl group having 4 to 8 carbon atoms; Represents an integer of 30 or more, n represents an integer of 10 or more, and Z has 3 carbon atoms.
Represents a branched alkyl group or substituted branched alkyl group having 8 to 8 carbon atoms, or a cycloalkyl group or substituted cycloalkyl group having 4 to 8 carbon atoms. The copolymer of the second invention according to the first invention has a weight average molecular weight of 15,000 to 60,000.

The copolymer according to the third aspect of the present invention is the copolymer according to the first or second aspect, which has a random structure. 4th
The copolymer of the invention according to any one of the first to third inventions is a copolymer of a fumarate diester represented by the following general formula (2) and Alfrey-Price
Is an empirical parameter representing the degree of resonance (Q value) and polarity (e value) of the double bond portion of the polymerizable monomer, based on styrene (Q = 1. 0,
e = -0.8). Is formed from an electron-donating monomer smaller than -0.2.

XOOC-CH = CH-COOY (2) (where X is a branched alkyl group having 3 to 8 carbon atoms or a substituted branched alkyl group, or a cycloalkyl group having 4 to 8 carbon atoms or Represents a substituted cycloalkyl group, and Y represents a branched alkyl group or a substituted branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group or a substituted cycloalkyl group having 4 to 8 carbon atoms.) In the combined structure, in the fourth aspect, the electron donating monomer is an alkyl vinyl ether represented by the following general formula (3).

Z—O—CH ＝ CH ₂ (3) (wherein Z is a branched or substituted branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group having 4 to 8 carbon atoms) Or a substituted cycloalkyl group.) In the copolymer of the sixth invention, in the fifth invention, the fumarate diester is 50 to 95 mol% and the alkyl vinyl ether is 5 to 50 mol%.

A method for producing a copolymer according to a seventh aspect of the present invention is a method of mixing a fumarate diester represented by the following general formula (2) and an alkyl vinyl ether represented by the following general formula (3): It performs a radical polymerization reaction.

XOOC-CH = CH-COOY (2) (where X is a branched alkyl group having 3 to 8 carbon atoms or a substituted branched alkyl group, or a cycloalkyl group having 4 to 8 carbon atoms) Alternatively, Y represents a substituted or unsubstituted cycloalkyl group, and Y represents a branched or substituted branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl or substituted cycloalkyl group having 4 to 8 carbon atoms.) Z—O—CH = CH ₂ (3) (where Z represents a branched alkyl group or a substituted branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group or a substituted cycloalkyl group having 4 to 8 carbon atoms)

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. The novel copolymer is represented by the following general formula (1).

[0020]

Embedded image

(Wherein X in the formula is a branched or substituted branched alkyl group having 3 to 8 carbon atoms,
8 represents a cycloalkyl group or a substituted cycloalkyl group, and Y represents a branched alkyl group or a substituted branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group or a substituted cycloalkyl group having 4 to 8 carbon atoms; Represents an integer of 30 or more, n represents an integer of 10 or more, and Z has 3 carbon atoms.
Represents a branched alkyl group or substituted branched alkyl group having 8 to 8 carbon atoms, or a cycloalkyl group or substituted cycloalkyl group having 4 to 8 carbon atoms. The ranges of X, Y, Z, m and n in the formula are defined from the viewpoint that the copolymer can exhibit low hygroscopicity, low dielectric properties, heat resistance and mechanical properties.

The novel copolymer comprises a fumarate diester represented by the following general formula (2) and an e value [Alfrey-Price] Q and e theory [Alfrey-Price theory] This is an empirical parameter indicating the degree of resonance (Q value) and polarity (e value) of the double bond portion, and styrene is used as a reference (Q = 1.0, e = −0.8). ]
Is preferably formed from an electron-donating monomer smaller than -0.2. The e value of this electron donating monomer is
From the viewpoint of polymerization reactivity, it is more preferably in the range of -0.2 to -1.8.

XOOC-CH = CH-COOY (2) (where X is a branched alkyl group having 3 to 8 carbon atoms or a substituted branched alkyl group, or a cycloalkyl group having 4 to 8 carbon atoms or Represents a substituted cycloalkyl group, and Y represents a branched alkyl group or a substituted branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group or a substituted cycloalkyl group having 4 to 8 carbon atoms.) By using the fumarate diester represented by 2) and an electron-donating monomer having a specific e value, the polymerization reactivity can be improved.

Specific examples of the functional group in which X and Y in the formula (2) are a branched alkyl group having 3 to 8 carbon atoms or a substituted branched alkyl include isopropyl, 1-chloro-2-propyl, 1, 3-dichloro-2-propyl group, sec-butyl group, 3-chloro-2-butyl group, tert-butyl group,
sec-amyl group, 3-pentyl group, 2,3-dimethyl-
Examples include a 3-pentyl group, a tert-amyl group, a neopentyl group, an isopentyl group, a 4-methyl-2-pentyl group, and a 2-ethyl-hexyl group.

Specific examples of the fumarate diester include:
Diisopropyl fumarate, di-sec-butyl fumarate,
Di-tert-butyl fumarate, diisobutyl fumarate, di-sec-amyl fumarate, di-tert-amyl fumarate, di-4-methyl-2-pentyl fumarate,
Di-sec-amyl fumarate, di-3-pentyl fumarate, bis (2,4-dimethyl-3-pentyl) fumarate, isopropyl-sec-butyl fumarate, tert-butyl-4-methyl-2-pentyl fumarate, isopropyl -Tert-butyl fumarate, sec-butyl-tert-
Butyl fumarate, sec-butyl-tert-amyl fumarate, di-4-methyl-pentyl fumarate, tert-butyl-isoamyl fumarate and the like.

Specific examples of the functional group in which X and Y are each a cycloalkyl group having 4 to 8 carbon atoms or a substituted cycloalkyl group include cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, 4-chloro- Examples include a cyclohexyl group, a 4-tert-butyl-cyclohexyl group, an isobornyl group, a bornyl group, and a norbornyl group.

Specific examples of the fumarate diester include:
Dicyclobutyl fumarate, dicyclopentyl fumarate, dicyclohexyl fumarate, dicycloheptyl fumarate, dicyclooctyl fumarate, bis (4
-Chloro-cyclohexyl) fumarate, bis (4-te
(rt-butyl-cyclohexyl) fumarate, diisobornyl fumarate, dibornyl fumarate, dinorbonyl fumarate and the like.

Specific examples of fumarate diesters in which X is an alkyl group and Y is a cycloalkyl group include isopropyl-cyclobutyl fumarate, 1-chloro-2-
Propyl-cyclopentyl fumarate, 1,3-dichloro-2-propyl-cyclohexyl fumarate, sec-
Butyl-cyclohexyl fumarate, 3-chloro-2-
Butyl-cyclohexyl fumarate, tert-butyl-cyclopentyl fumarate, tert-butyl cyclohexyl fumarate, sec-amyl-cyclohexyl fumarate, 3-pentyl-bornyl fumarate, 2,3-dimethyl-3-pentyl-adamantyl fumarate Rate, tert-
Amyl-cyclohexyl fumarate, neopentyl-cyclopentyl fumarate, 4-methyl-2-pentyl-
Cyclohexyl fumarate, 2-ethyl-hexyl-cyclohexyl fumarate and the like can be mentioned.

As the method for producing the fumarate diesters, all of the commonly used synthesis means can be used. Such synthesis means include, for example, 1) esterification reaction of fumaric acid with the corresponding alcohol, 2) esterification reaction of maleic acid with the corresponding alcohol and isomerization reaction to fumaric acid ester, 3) anhydrous Means such as an equimolar reaction between maleic acid and a primary alcohol, followed by an esterification reaction with a secondary alcohol and an isomerization reaction to a fumaric ester, and 4) a reaction between fumaryl chloride and a corresponding alcohol are employed. You.

Among the above fumarate diesters, those having a relatively small molecular weight are liquids or crystals having a low melting point at room temperature, while those having a large molecular weight tend to be solids. The electron donating monomer is preferably an alkyl vinyl ether represented by the following general formula (3).

Z—O—CH ＝ CH ₂ (3) (wherein Z is a branched alkyl group having 3 to 8 carbon atoms or a substituted branched alkyl group, or a cycloalkyl group having 4 to 8 carbon atoms) Or Z represents a substituted or unsubstituted cycloalkyl group.) Z is a branched or substituted branched alkyl group having 3 to 8, preferably 4 to 6, carbon atoms, or a cycloalkyl group or substituted with 4 to 8, preferably 5 or 6 carbon atoms. Represents a cycloalkyl group.

Specific examples of the functional group in which Z is a branched alkyl group having 3 to 8 carbon atoms or a substituted branched alkyl group include:
Isopropyl group, tert-butyl group, sec-butyl group, isobutyl group, tert-amyl group, 4-methyl-2-pentyl group, 3-pentyl group, 2,4-dimethyl-3-pentyl group, 1-chloroisopropyl And a 1,3-dichloroisopropyl group. Specific examples of the alkyl vinyl ether include isopropyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, sec-butyl vinyl ether, tert-amyl vinyl ether, 4-methyl-2-pentyl vinyl ether, 3-pentyl vinyl ether, and 2,4-dimethyl-
Examples thereof include 3-pentyl vinyl ether, 1-chloroisopropyl vinyl ether, and 1,3-dichloroisopropyl vinyl ether.

Here, for example, the Q value and the e value in the Q and e theory of isobutyl vinyl ether are 0.0
23 and -1.77. Specific examples of the functional group in which Z is a cycloalkyl group having 4 to 8 carbon atoms or a substituted cycloalkyl group include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a 4-hydroxy-cyclohexyl group, and a 4-methylol- group. Cyclohexyl group,
Cycloheptyl group, cyclooctyl group, 4-methyl-cyclohexyl group, 4-tert-butylcyclohexyl group,
Examples include a bornyl group, an isobornyl group, and a menthyl (2-isopropyl-4-methyl-cyclohexyl) group.

Specific examples of cycloalkyl vinyl ethers include cyclobutyl vinyl ether, cyclopentyl vinyl ether, cyclohexyl vinyl ether, 4-hydroxy-cyclohexyl vinyl ether, 4-methylol-cyclohexyl vinyl ether cycloheptyl vinyl ether, cyclooctyl vinyl ether,
4-methyl-cyclohexyl vinyl ether, 4-tert
-Butylcyclohexyl vinyl ether, bornyl vinyl ether, isobornyl vinyl ether, and menthyl (2-isopropyl-4-methyl-cyclohexyl) vinyl ether.

In the method for producing the above-mentioned alkyl vinyl ether, all the synthesis means usually used can be used. For example, by reacting the corresponding alcohol with acetylene in the presence of a catalyst, the desired alkyl vinyl ether can be easily obtained.

The copolymer has a weight average molecular weight of 1
It is desirable to be 5000 to 60000. By the weight average molecular weight in such a high degree of polymerization,
Good electrical and mechanical properties of the copolymer can be maintained.

It is preferable that the copolymer has a random structure. Since the copolymer has a random structure, the copolymer can be easily obtained by radical copolymerization of a fumarate diester and an electron donating monomer such as an alkyl vinyl ether.

The above-mentioned copolymer is easily synthesized by polymerizing a mixture of a fumarate diester and an alkyl vinyl ether. However, the molecular weight, mechanical physical properties, heat resistance, etc. of the copolymer are fumarate-based. It is greatly affected by the type and composition of diester and alkyl vinyl ether. From the viewpoints of electrical insulation, dielectric properties, heat resistance and the like of the copolymer, the molar fraction of the fumarate diester charged when forming the copolymer is usually 50 to 95 mol%, preferably 65 to 85 mol. %. Therefore, the molar fraction of the alkyl vinyl ether is usually 5 to 50 mol%, preferably 15 to 35 mol%. When the molar fraction of the fumarate diester exceeds 95 mol%, the polymerization becomes difficult, and the conversion to the polymer decreases. On the other hand, when the molar fraction of the fumarate diester is less than 50%, not only does the copolymerization rate decrease sharply, but also the electrical properties and heat resistance of the copolymer decrease.

The copolymer can be produced by adding a polymerization initiator which generates radicals thermally to a mixture of a fumarate diester and an alkyl vinyl ether and carrying out bulk polymerization as it is, or using a water-soluble polymer or an inorganic polymer. It is produced by dispersing in an aqueous solution containing a dispersant and performing suspension polymerization, or by performing solution polymerization in an organic solvent that dissolves the copolymer. Examples of such a polymerization initiator include, for example, 2,
2′-azobisisobutyronitrile (AIBN), 2,
2'-azobiscyclohexanecarbonitrile (AC
Azo-based organic compounds such as benzoyl peroxide (BP)
O), tert-butyl hydroperoxide (TBHP),
Organic peroxides such as di-tert-butyl peroxide (DtBP) and dicumyl peroxide (DCP) are exemplified.

The mixture is emulsified with an aqueous solution containing a suitable surfactant (emulsifier) and the like, and then an inorganic thermal polymerization initiator such as potassium persulfate and sodium persulfate is added to carry out emulsion polymerization. It can also be manufactured by the following.

When the copolymer is used as an electric insulating material (dielectric), a polymerization method in which impurities are mixed as little as possible, that is, a bulk polymerization method or a solution polymerization method is preferable. Further, a copolymer can be produced by photopolymerization by adding a polymerization initiator which generates a radical upon irradiation with light to the monomer mixture. Examples of such a polymerization initiator include, for example, benzophenone, xanthone, thioxanthone, acetophenone, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-2-methyl-4′-isopropylpropiophenone, 1-hydroxycyclohexyl. Examples include phenyl ketone, 2,2-diethoxyacetophenone, benzyl, methylbenzoyl formate, and benzoin isopropyl ether. In addition, in the absence of a photopolymerization initiator, the polymerization proceeds even when irradiated with γ-rays or electron beams to obtain a copolymer.

Further, the above-mentioned monomer mixture containing a polymerization initiator is applied on the surface of a material such as paper, wood, plastic, metal, etc., and is heated or irradiated with light or inert light in an inert gas. A polymer can be formed.

According to the above embodiment, the following effects are exhibited. -The novel copolymer of the embodiment is represented by the general formula (1), and has a branched alkyl group or a cycloalkyl group as the substituents X, Y and Z. For this reason, it is formed by copolymerization of an electron-accepting fumarate diester having good polymerizability and an alkyl vinyl ether having good copolymerization reactivity therewith, and is almost completely polymerized. Therefore, the copolymer can exhibit excellent low moisture absorption, low dielectric properties, heat resistance and mechanical properties.

Since the novel copolymer of the embodiment has excellent electrical, thermal and mechanical properties as described above, it has functions as an electrical insulating material for electronic parts and the like, a resist material and the like. Useful as a conductive material.

According to the method for producing a copolymer of the embodiment, an electron-accepting fumarate diester having good polymerizability and an alkyl vinyl ether having good copolymerization reactivity therewith are radically copolymerized. For this reason, the polymerization reaction rate and the polymerization conversion can be improved.

[0046]

EXAMPLES The following embodiments will be described more specifically with reference to examples, but the present invention is not limited thereto. (Example 1) Dicyclohexyl fumarate (DcHF) (50 mmo) was added to a glass ampoule having a content of 30 ml.
l), tert-butyl vinyl ether (tBuVE) (5
0 mmol) and tert-butyl peroxyneodecanoate (perbutyl ND) (2 mmol), and bubbling with dry nitrogen gas was performed to sufficiently purge with nitrogen, and then the ampoule was sealed with a burner. The ampoule was placed in a shaking water bath set at 60 ° C.
Time went.

After the polymerization was completed, toluene was added to the ampoule to dissolve it, and the content was poured into a large amount of methanol to precipitate and separate the copolymer. This copolymer is treated with toluene-
After performing a reprecipitation purification operation with a methanol-based solvent, the precipitate was dried under reduced pressure to obtain a DnPF-tBVE copolymer in a yield of 83%. Tables 1 and 2 summarize the copolymerization conditions, copolymerization results, and the results of measuring the molecular weight of the obtained copolymer by GPC.

The abbreviations in Table 1 have the following meanings. DnBF: di-n-butyl fumarate, DiBF: diisobutyl fumarate, DsBF: dis-butyl fumarate, D3PF: di-3-pentyl fumarate, DtBF:
Di-t-butyl fumarate, DNeopF: Dineopentyl fumarate, D4MPF: Di-4-methyl-2-pentyl fumarate, DcPF: Dicyclopentyl fumarate, DcHF: Dicyclohexyl fumarate, tAmV
E: tert-amyl vinyl ether, cHVE: cyclohexyl vinyl ether, iPVE: isopropyl vinyl ether, tBVE: tert-butyl vinyl ether, perbutyl PV: tert-butyl peroxypivalate, Parkmill ND: cumyl peroxy neodecanoate.

The above tAmVE, cHVE, iP
The e value in the Q and e theory of VE and tBVE is −0.
Thermal analysis of the resulting copolymer in the range of 2-1.8, ie, differential scanning calorimetry (DSC) and thermogravimetry (TGA), was performed and the results are shown in Table 3. Summarized. For the copolymer, an infrared absorption spectrum (IR) analysis and a nuclear magnetic resonance spectrum (NM)
R) An analysis was performed and their spectra are shown in FIGS.

In the infrared absorption spectrum shown in FIG.
The following absorption was observed. 1750 cm ^-1 : carbonyl group (> C = O), 2950
m ^-1: methylene group (-CH ₂ -) or a methyl group (-CH
₃ ) 1100 cm ^-1 : ether group (-C-OC), 1
400 cm ^-1 : t-butyl group [-C (CH ₃ ) ₃ ], 1
450 cm ^-1 : methylene group (-CH _2- ) or methyl group (-CH ₃ ), 1150 cm ^-1 : ester group (-COO
-), 1000 cm ^-1 : methylene group of a cyclo ring (-CH
_2- ) In the nuclear magnetic resonance spectrum of FIG. 2, the following peaks were observed.

Around 4.8 ppm: methine proton on the cyclohexane ring; around 3.8 ppm: vinyl ether methine proton in the main chain; around 2.8 ppm: methine proton of fumarate in the main chain; around 1.8 ppm: in the main chain Vinyl ether methylene proton, 1.7 to 1.3 pp
Near m: methylene proton of cyclohexane ring, 1.2
Around ppm: methyl proton of t-butyl group From the infrared absorption spectrum and the nuclear magnetic resonance spectrum as described above, the obtained copolymer is a compound in which X and Y in the above general formula (1) are cyclohexyl groups, and Z is tert- It was confirmed that the compound had a butyl group. (Example 2) Radical copolymerization was carried out in the same manner as in Example 1 except that tert-amyl vinyl ether (tAmVE) (50 mmol) was used instead of tBuVE in Example 1. Tables 1 and 2 show the polymerization conditions and copolymerization results.
Summarized in

The obtained copolymer was subjected to DSC and T
Analysis by GA was performed and the results are summarized in Table 3. In addition, the copolymer was subjected to IR and NMR analyses, and the spectra thereof are shown in FIGS.

In the infrared absorption spectrum shown in FIG.
The following absorption was observed. 1750 cm ^-1 : carbonyl group (> C = O), 2950
m ^-1: methylene group (-CH ₂ -) or a methyl group (-CH
₃ ) 1100 cm ^-1 : ether group (-C-OC), 1
400 cm ^-1 : tert-amyl group [-C (CH ₃ ) ₂ CH
₂ CH ₃ ], 1450 cm ^-1 : methylene group (-CH
_2- ) or a methyl group (-CH ₃ ), 1150 cm ^-1 : an ester group (-COO-), 1000 cm ^-1 : a methylene group of a cyclo ring (-CH _2- ). The following peaks were observed.

Approximately 4.8 ppm: methine proton on the cyclohexane ring; approximately 3.8 ppm: vinyl ether methine proton in the main chain; approximately 2.8 ppm: methine proton of fumarate in the main chain; approximately 1.8 ppm: methine proton in the main chain Vinyl ether methylene proton, 1.7 to 1.3 pp
Near m: methylene proton of cyclohexane ring, 1.2
Around ppm: methyl proton of t-butyl group, 0.8 p
Near pm: methyl proton of an ethyl group in the tert-amyl group From these infrared absorption spectrum and nuclear magnetic resonance spectrum, the obtained copolymer is a compound in which X and Y in the above general formula (1) are cyclohexyl group, Z Was confirmed to have a tert-amyl group. (Examples 3 to 12) In place of DnPF, tBVE and perbutyl ND in Example 1, copolymerization was carried out in place of the fumarate diester, vinyl ether and polymerization initiator shown in Table 1. Tables 1 and 2 show the copolymerization conditions and copolymerization results.
Summarized in

[0055]

[Table 1]

[0056]

[Table 2]

[0057]

[Table 3]

As shown in Table 2, it was found that the copolymers of Examples 1 to 12 generally had a high polymerization yield and a high molecular weight. Further, as shown in Table 3, Example 1
In addition, it was confirmed that the copolymer of Example 2 had a high glass transition temperature and a high thermal decomposition temperature. (Example 13) Dicyclohexyl fumarate (DcHF) was added to each of five Pyrex glass ampules.
(0.07 mol), tert-amyl vinyl ether (TA
mVE) (0.03 mol) and benzoin methyl ether (BME) (0.002 mol) as a photopolymerization initiator
Was taken. Then, a sufficiently dried nitrogen gas was bubbled to sufficiently purge the inside with nitrogen, and then the ampule was sealed with a burner.

These five ampules were set in a merry-go-round type UV irradiation device (high-pressure mercury lamp) equipped with a filter, and irradiated with UV while cooling with water. Based on the relationship between UV irradiation intensity and time, which was checked in advance, after UV irradiation was performed for a predetermined time, the ampoule was taken out, polymerization was stopped, and the content was dissolved in toluene, and then poured into a large amount of methanol for common use. The polymer was precipitated. The obtained copolymer was purified by reprecipitation, dried, and weighed. UV irradiation conditions and UV
Table 4 summarizes the copolymerization results.

[0060]

[Table 4]

As shown in Table 4, the copolymer of Example 13 had a higher polymerization conversion and a higher molecular weight as the amount of UV irradiation increased. (Examples 14 to 17) DcHF and tAm of Example 13
In place of VE, the monomers shown in Table 5 were used, and UV polymerization was performed using the UV irradiation apparatus of Example 13. Table 5 summarizes the UV irradiation conditions and the polymerization results.

[0062]

[Table 5]

As shown in Table 5, it was found that the copolymers of Examples 14 to 17 generally had a high molecular weight.
The technical idea grasped from the above embodiment will be described below.

In the general formula (3), Z is a group having 4 to 4 carbon atoms.
The copolymer according to claim 5, which is a branched alkyl group or a substituted branched alkyl group having 6 or a cycloalkyl group or a substituted cycloalkyl group having 5 or 6 carbon atoms.

With such a constitution, the polymerization reactivity and the physical properties of the obtained copolymer can be further improved. -The fumarate diester is 65 to 85 mol%,
The copolymer according to claim 6, wherein the content of the alkyl vinyl ether is 15 to 35 mol%.

With such a constitution, the polymerization reactivity between the fumarate diester and the alkyl vinyl ether can be more favorably maintained. The method for producing a copolymer according to claim 7, wherein the radical polymerization reaction is performed by a bulk polymerization method or a solution polymerization method.

According to this production method, impurities mixed into the obtained copolymer can be suppressed as much as possible, and a material suitable as an electric insulating material can be obtained.

[0068]

As described above, according to the present invention, the following effects can be obtained. According to the copolymer of the first invention, the copolymer is a novel one and has excellent low moisture absorption, low dielectric properties, excellent heat resistance and mechanical properties, and functions as an electrical insulating material and a resist material. Useful as a material.

According to the copolymer of the second invention, in addition to the effect of the first invention, the weight average molecular weight of the copolymer is 1500
Since the value is set in the range of 0 to 60000, the physical properties of the copolymer can be favorably maintained.

According to the copolymer of the third invention, in addition to the effects of the first or second invention, the copolymer can be easily obtained because the copolymer has a random structure. According to the copolymer of the fourth invention, in addition to the effects of any one of the first to third inventions, the copolymer is obtained by combining the predetermined fumarate diester with an electron-donating monomer having a specific e value. Since it is formed from a body, the polymerization reactivity can be improved.

According to the copolymer of the fifth invention, in addition to the effect of the fourth invention, since a specific alkyl vinyl ether is used as the electron-donating monomer, the polymerization reactivity and the obtained copolymer are improved. Physical properties can be improved.

According to the copolymer of the sixth invention, in addition to the effects of the fifth invention, the copolymer containing fumarate diester as a main component,
By using alkyl vinyl ether as a minor component,
Good polymerization reactivity can be maintained.

According to the method for producing a copolymer of the seventh aspect, the rate of polymerization reaction between fumarate diester and alkyl vinyl ether can be improved, the polymerization conversion can be increased, and the copolymer can be obtained in good yield. Can be.

[Brief description of the drawings]

FIG. 1 is an infrared absorption spectrum of the copolymer of Example 1.

FIG. 2 is a nuclear magnetic resonance spectrum of the copolymer of Example 1.

FIG. 3 is an infrared absorption spectrum of the copolymer of Example 2.

FIG. 4 is a nuclear magnetic resonance spectrum of the copolymer of Example 2.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J100 AE02Q AE06Q AE09Q AL34P AL39P BA03Q BB01P BC02P BC02Q BC03P BC03Q BC04P BC04Q BC08P BC08Q CA04 DA01 JA37 JA44

Claims (7)

[Claims] 1. A copolymer represented by the following general formula (1). Embedded image (However, X in the formula represents a branched alkyl group having 3 to 8 carbon atoms or a substituted branched alkyl group, or a cycloalkyl group having 4 to 8 carbon atoms or a substituted cycloalkyl group, and Y represents a branched alkyl group having 3 to 8 carbon atoms. Represents an alkyl group or a substituted branched alkyl group, or a cycloalkyl group or a substituted cycloalkyl group having 4 to 8 carbon atoms, m represents an integer of 30 or more;
n represents an integer of 10 or more; Z represents a branched alkyl group having 3 to 8 carbon atoms or a substituted branched alkyl group;
8 represents a cycloalkyl group or a substituted cycloalkyl group. ) 2. The weight average molecular weight is 15,000 to 6000.
The copolymer according to claim 1, which is 0. 3. The copolymer according to claim 1, which has a random structure. 4. A fumarate diester represented by the following general formula (2), and Alfrey-Price
E, an empirical parameter representing the degree of resonance (Q value) and polarity (e value) of the double bond portion of the polymerizable monomer, based on styrene (Q = 1. 0,
e = -0.8). Is formed from an electron-donating monomer smaller than -0.2. XOOC-CH = CH-COOY (2) (wherein X is a branched alkyl group or substituted branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group or substituted cycloalkyl having 4 to 8 carbon atoms) Y represents a branched alkyl group or a substituted branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group or a substituted cycloalkyl group having 4 to 8 carbon atoms.) 5. The copolymer according to claim 4, wherein the electron donating monomer is an alkyl vinyl ether represented by the following general formula (3). Z—O—CH ＝ CH ₂ (3) (wherein, Z represents a branched alkyl group or a substituted branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group or a substituted cycloalkyl group having 4 to 8 carbon atoms) Represents an alkyl group.) 6. The method according to claim 1, wherein the fumarate diester is 50 to 95.
The copolymer according to claim 5, wherein the amount of the alkyl vinyl ether is 5 to 50% by mol. 7. A method for producing a copolymer in which a fumarate diester represented by the following general formula (2) is mixed with an alkyl vinyl ether represented by the following general formula (3) to perform a radical polymerization reaction: . XOOC-CH = CH-COOY (2) (where X is a branched alkyl group or substituted branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group or substituted cycloalkyl having 4 to 8 carbon atoms) Represents an alkyl group, and Y represents a branched alkyl group or a substituted branched alkyl group having 3 to 8 carbon atoms, or a cycloalkyl group or a substituted cycloalkyl group having 4 to 8 carbon atoms.) Z—O—CH ＝ CH _2. ··· (3) (where, Z in the formula represents a branched alkyl group having 3 to 8 carbon atoms or a substituted branched alkyl group, or a cycloalkyl group having 4 to 8 carbon atoms or a substituted cycloalkyl group)