Multifunctional vinyl compound, composition thereof, and cured product

Abstract

The present invention provides a vinyl compound that has excellent solvent solubility, that yields a cured product having excellent heat resistance, thermal decomposition stability, thermal conductivity, low dielectric constant, low dielectric tangent, and flame retardance, and that is useful for sealing electrical and electronic components and as a circuit board material.　Provided is a multifunctional vinyl compound represented by general formula (1). In formula (1), R1-R4 each independently represent a hydrogen atom or a monovalent C1-6 hydrocarbon group.

Description

Polyfunctional vinyl compound, composition thereof, and cured product

[0001] The present invention relates to a vinyl compound, and more particularly to a polyfunctional vinyl compound having excellent solvent solubility and useful as an insulating material for electric and electronic components such as semiconductor encapsulation, laminates, and heat dissipation substrates; a composition thereof; and a cured resin product obtained by curing the compound or the composition, which has excellent heat resistance, thermal decomposition stability, thermal conductivity, low dielectric constant, low dielectric dissipation factor, and flame retardancy.

[0002] As communication speeds and volumes increase, research into high-speed communication technologies is actively underway to improve signal transmission speeds for printed circuit boards, encapsulants, and casting materials used in communication devices. Electronic materials for such applications require materials that can reduce dielectric loss, and for printed circuit board applications, curable resins that can be multilayered are also required.

[0003] On the other hand, electronic computing components that process such large amounts of data generate a lot of heat, and heat accumulation can cause problems such as a decrease in the processing speed of the electronic computing components, so various methods have been known to appropriately cool printed circuit boards using heat sinks or the like, such as incorporating heat transfer members such as copper coins and copper inlays (Patent Document 1), or using fillers with special shapes (Patent Document 2).However, these methods are undesirable because they lead to increased weight and larger equipment.

[0004] Furthermore, methods for increasing the thermal conductivity of encapsulant compositions have been developed to remove heat from electronic computing components by examining the type and amount of various fillers. For example, attempts have been made to incorporate inorganic fillers with high thermal conductivity, such as crystalline silica, silicon nitride, aluminum nitride, and spherical alumina powder (Patent Documents 3 and 4). However, increasing the content of the inorganic filler increases the viscosity during molding, reducing fluidity and impairing moldability. Therefore, there are limitations to simply increasing the content of the inorganic filler.

[0005] Given the above background, methods for improving the thermal conductivity of compositions by increasing the thermal conductivity of the matrix resin itself have also been investigated. For example, liquid crystalline epoxy resins with rigid mesogenic groups and epoxy resin compositions using such resins have been proposed (Patent Documents 5 and 6). However, these epoxy resin compositions use aromatic diamine compounds as curing agents, which limit the high inorganic filler loading and also pose problems with electrical insulation. Furthermore, when aromatic diamine compounds are used, although liquid crystallinity can be confirmed in the cured product, the degree of crystallinity of the cured product is low, and it is insufficient in terms of high thermal conductivity, low thermal expansion, low moisture absorption, etc. Furthermore, to achieve liquid crystallinity, a strong magnetic field is required to orient the molecules, which poses significant equipment limitations for widespread industrial use. Furthermore, in systems containing inorganic fillers, the thermal conductivity of the inorganic filler is overwhelmingly greater than that of the matrix resin. Therefore, increasing the thermal conductivity of the matrix resin itself does not significantly contribute to improving the thermal conductivity of the composite material, and sufficient thermal conductivity improvement has not been achieved.

[0006] Patent Document 7 proposes a tetra- or higher functional vinyl resin having a biphenyl skeleton as a multifunctional vinyl resin that achieves both high thermal conductivity and low dielectric tangent. However, the document does not describe the solvent solubility of the multifunctional vinyl resin or the polyhydric hydroxyl resin that is its raw material, and does not mention at all the influence that impurities such as residual polar groups have on thermal conductivity.

[0007] JP 2009-170493, WO 2013 / 100172, JP 11-147936, JP 2002-309067, JP 11-323162, JP 9-118673, WO 2021-200414

[0008] An object of the present invention is to provide a vinyl composition that has excellent solvent solubility and gives a cured product that is excellent in heat resistance, thermal decomposition stability, thermal conductivity, low dielectric constant, low dielectric dissipation factor, and flame retardancy, and is useful for sealing electric and electronic components, as a circuit board material, etc., and to provide the cured product. Another object is to provide a vinyl compound that can be used in the vinyl composition.

[0009] The present inventors have conducted extensive research and have found that a polyfunctional vinyl compound having a specific structure is expected to solve the above-mentioned problems, and that a cured product thereof exhibits effects in terms of heat resistance, thermal decomposition stability, thermal conductivity, low dielectric constant, low dielectric dissipation factor, and flame retardancy.

[0010] That is, the present invention is a polyfunctional vinyl compound represented by the following general formula (1). In formula (1), R1 to R4 each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms.

[0011] At least one of R1 to R4 of the polyfunctional vinyl compound is preferably a methyl group or a phenyl group.

[0012] The present invention also provides a polyfunctional vinyl composition containing the above polyfunctional vinyl compound and a radical polymerization initiator as essential components, and a cured polyfunctional vinyl product obtained by curing this polyfunctional vinyl composition.

[0013] The polyfunctional vinyl compound of the present invention has excellent solvent solubility and is suitable for use in vinyl resin compositions and cured products thereof for applications such as lamination, molding, casting, adhesion, etc. Furthermore, the cured products also have excellent heat resistance, thermal decomposition stability, thermal conductivity, low dielectric constant, low dielectric dissipation factor, and flame retardancy, making them suitable for sealing electric and electronic components, circuit board materials, etc.

[0014] 1 is a GPC chart of the polyfunctional vinyl compound obtained in Example 1.

[0015] The present invention will be described in detail below.

[0016] The present invention is a polyfunctional vinyl compound represented by the following general formula (1). R1 to R4 are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms. From the viewpoint of solvent solubility, an alkyl group is preferred, and from the viewpoint of heat resistance and high thermal conductivity, an aromatic group is preferred. With an alkyl group having more than 6 carbon atoms, it becomes difficult to suppress molecular motion, and there is a concern that compatibility may decrease. Furthermore, a bulky structure with significant steric hindrance increases crystallinity, which may result in concerns about solvent solubility. A methyl group or a phenyl group is more preferred. R1 to R4 may be a mixture of different structures.

[0017] In the polyfunctional vinyl compound of the present invention, the substitution positions of the vinylbenzyl ethers are not particularly limited, but from the viewpoints of thermal conductivity and heat resistance, they are preferably para-positions relative to the methine groups connecting the three aromatic rings. In particular, it is more preferable that all three vinylbenzyl ethers are para-positions.

[0018] The number average molecular weight (Mn) of the polyfunctional vinyl compound of the present invention is preferably 2000 or less, more preferably 1500 or less. It may also contain a multi-branched structure represented by the following general formula (2): n is the number of repeating units and represents a number from 0 to 20. Preferably, it is a mixture of components with different n values. From the viewpoint of thermal conductivity, the content of n=0 units is preferably 50 wt% or more, more preferably 80 wt% or more. In formula (2), the isomer where n=0 is the polyfunctional vinyl compound represented by formula (1). When the polyfunctional vinyl compound of the present invention is represented by formula (2), the average value (number average) of n is preferably in the range of 0.01 to 5.0, more preferably in the range of 0.01 to 2.0, and even more preferably in the range of 0.01 to 1.0. Therefore, the polyfunctional vinyl compound of the present invention is also called a polyfunctional vinyl resin.

[0019] The polyfunctional vinyl compound of the present invention has a vinyl equivalent of preferably 150 to 450 g / eq, more preferably 200 to 300 g / eq. If the vinyl equivalent is less than this range, the reaction will proceed too rapidly, making it difficult to control the reaction. If the vinyl equivalent is greater than this range, the reactivity will decrease, making it difficult to obtain a uniform cured product.

[0020] The polyfunctional vinyl compound of the present invention can be obtained by reacting a trifunctional hydroxy compound with chloromethylstyrene. If the amount of unreacted hydroxyl groups remaining is less than 5,000 g / eq, curing will be insufficient, resulting in reduced thermal conductivity and heat resistance. Furthermore, since hydroxyl groups are polar groups, their remaining presence may hinder the reduction of the dielectric constant and dielectric loss tangent. The hydroxyl group equivalent is preferably 5,000 g / eq or more, more preferably 10,000 g / eq or more. Meanwhile, the chlorine component is derived from the raw material chloromethylstyrene. If chlorine components remain, as with hydroxyl groups, there is a concern that they may hinder the reduction of the dielectric constant and dielectric loss tangent, and that the curing reaction may be inhibited by polar groups, resulting in reduced thermal conductivity and heat resistance. The total chlorine content is preferably 2,000 ppm or less, more preferably 1,000 ppm or less.

[0021] The polyfunctional vinyl compound of the present invention can be obtained by reacting a trifunctional hydroxy compound represented by formula (3) with an aromatic vinylating agent. R1 to R4 are the same as those in the vinyl compound of formula (1).

[0022] The trifunctional hydroxy compound of formula (3) preferably has a hydroxyl group equivalent of 90 to 350 g / eq, more preferably 100 to 200 g / eq. The trifunctional hydroxy compound of formula (3) can be produced by a general method, for example, by polycondensation of a monohydric phenol compound and an aromatic aldehyde.

[0023] Examples of the monohydric phenol compound include monoalkylphenols such as phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, p-octylphenol, p-t-butylphenol, o-cyclohexylphenol, m-cyclohexylphenol, and p-cyclohexylphenol; dialkylphenols such as 2,5-xylenol, 3,5-xylenol, 3,4-xylenol, 2,4-xylenol, and 2,6-xylenol; trialkylphenols such as 2,3,5-trimethylphenol and 2,3,6-trimethylphenol; and hydroxybiphenyls such as 2-phenylphenol, 4-phenylphenol, 3-benzyl-1,1'-biphenyl-2-ol, 3-benzyl-1,1'-biphenyl-4-ol, 3-phenylphenol, and 2,6-diphenylphenol. In terms of solvent solubility, reactivity, and supplyability, 2,5-xylenol, 2,6-xylenol, and 2-phenylphenol are particularly preferred. These phenolic compounds can be used alone or in combination of two or more.

[0024] Examples of aromatic aldehydes include hydroxybenzaldehydes such as 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, and 4-hydroxybenzaldehyde. From the viewpoints of heat resistance and thermal conductivity, 4-hydroxybenzaldehyde is preferred.

[0025] The polycondensation of a phenol compound and an aromatic aldehyde may be carried out using an acid catalyst, such as acetic acid, oxalic acid, sulfuric acid, hydrochloric acid, phenolsulfonic acid, paratoluenesulfonic acid, zinc acetate, manganese acetate, etc. These acid catalysts may be used alone or in combination of two or more. Among these acid catalysts, sulfuric acid and paratoluenesulfonic acid are preferred because of their excellent activity. The acid catalyst may be added before or during the reaction.

[0026] The polycondensation of the phenol compound and the aromatic aldehyde may be carried out in the presence of a solvent, if necessary, to obtain a polycondensation product. Examples of the solvent include monoalcohols such as methanol, ethanol, and propanol; polyols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, trimethylene glycol, diethylene glycol, polyethylene glycol, and glycerin; glycol ethers such as 2-ethoxyethanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monopentyl ether, ethylene glycol dimethyl ether, ethylene glycol ethyl methyl ether, and ethylene glycol monophenyl ether; cyclic ethers such as 1,3-dioxane, 1,4-dioxane, and tetrahydrofuran; glycol esters such as ethylene glycol acetate; and ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. These solvents can be used alone or in combination of two or more. Among these solvents, 2-ethoxyethanol is preferred because it has excellent solubility for the resulting compound.

[0027] The reaction temperature during polycondensation of the phenol compound and the aromatic aldehyde is in the range of 20 to 140°C, preferably in the range of 80 to 110°C.

[0028] The charging ratio of the phenol compound to the aromatic aldehyde is in the range of 1 / 0.1 to 1 / 0.5 in terms of molar ratio, and more preferably in the range of 1 / 0.3 to 1 / 0.5, since the phenol compound after the reaction can be easily removed by reprecipitation or the like.

[0029] The polyfunctional vinyl compound of the present invention can be suitably obtained by reacting a trifunctional hydroxy compound with an aromatic vinylating agent. For example, the vinyl compound of the present invention represented by the above formula (1) can be obtained by reacting a trifunctional hydroxy compound represented by the above formula (3) with chloromethylstyrene. This reaction can be carried out in the same manner as well-known vinylation reactions. The blending ratio is preferably 0.8 to 1.2 equivalents of aromatic vinylating agent (e.g., chloromethylstyrene) per 1.0 equivalent of the hydroxyl group, which is the functional group of the trifunctional hydroxy compound. However, if the reactivity of the trifunctional hydroxy compound is low, it is advisable to charge an excess amount of aromatic vinylating agent and remove it after the reaction.

[0030] As the aromatic vinylating agent, halomethylstyrene, particularly chloromethylstyrene, is preferred. Other examples include bromomethylstyrene and its isomers, and those having a substituent. Regarding the substitution position of the halomethyl compound, for example, in the case of halomethylstyrene, the 4-position is preferred, and it is preferred that the 4-position compound accounts for 60% by weight or more of the total.

[0031] The reaction between a trifunctional hydroxy compound and an aromatic vinylating agent can be carried out in the absence of a solvent or in the presence of a solvent. The reaction can be carried out by adding the aromatic vinylating agent to the hydroxy compound, adding a metal hydroxide, and then removing the resulting metal salt by filtration, washing with water, or other methods. Examples of solvents include, but are not limited to, methyl ethyl ketone, benzene, toluene, xylene, methyl isobutyl ketone, diethylene glycol dimethyl ether, cyclopentanone, and cyclohexanone. From the viewpoint of reactivity, methyl ethyl ketone is preferred. Specific examples of metal hydroxides include, but are not limited to, sodium hydroxide and potassium hydroxide.

[0032] The vinylation reaction is preferably carried out at a temperature of 90° C. or less, more preferably 70° C. or less. At temperatures higher than this temperature, self-polymerization of the vinylbenzyl ether group due to heat proceeds, making it difficult to control the reaction. To suppress self-polymerization, a polymerization inhibitor such as quinones, nitro compounds, nitrophenols, nitroso compounds, nitrone compounds, or oxygen may be used.

[0033] The end point of the reaction can be determined by tracking the remaining amount of halomethylstyrene as an aromatic vinylating agent using various chromatograms such as GPC, and the reaction rate can be adjusted by the type and amount of metal hydroxide, the addition rate, the solids concentration, etc.

[0034] The polyfunctional vinyl compound of the present invention can be cured by itself, but it is also suitable to use it as a polyfunctional vinyl composition containing various additives. In particular, it can be cured by adding a radical polymerization initiator such as an azo compound or an organic peroxide to accelerate curing.

[0035] The polyfunctional vinyl composition of the present invention contains a polyfunctional vinyl compound and a radical polymerization initiator as essential components, but can also contain other vinyl compounds and other thermosetting resins, such as epoxy resins, oxetane resins, maleimide resins, acrylate resins, polyester resins, polyurethane resins, polyphenylene ether resins, and benzoxazine resins.

[0036] In order to increase the thermal conductivity, inorganic fillers such as glass cloth, carbon fiber, alumina, and boron nitride may be added.

[0037] For the purpose of imparting higher thermal conductivity, inorganic fillers with higher thermal conductivity are preferred. It is preferably 20 W / m K or higher, more preferably 30 W / m K or higher, and even more preferably 50 W / m K or higher. At least a portion of the inorganic filler, preferably 50 wt % or more, has a thermal conductivity of 20 W / m K or higher. The average thermal conductivity of the inorganic filler as a whole increases in order of preference from 20 W / m K or higher, to 30 W / m K or higher, and to 50 W / m K or higher.

[0038] Examples of inorganic fillers having such thermal conductivity include inorganic powder fillers such as boron nitride, aluminum nitride, silicon nitride, silicon carbide, titanium nitride, zinc oxide, tungsten carbide, alumina, and magnesium oxide.

[0039] Various additives may be added to improve adhesive strength and ease of handling of the composition, such as silane coupling agents, antifoaming agents, internal mold release agents, and flow control agents.

[0040] The polyfunctional vinyl compound or polyfunctional vinyl composition of the present invention can also be dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, or methyl isobutyl ketone, impregnated into a substrate such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, or paper, and heated and dried to obtain a prepreg, which can then be hot-press molded to obtain a cured product.

[0041] In some cases, the composition can be applied to a sheet-like material such as copper foil, stainless steel foil, polyimide film, or polyester film to form a laminate, and the resin sheet obtained by heating and drying can be hot-press molded to obtain a cured product.

[0042] The present invention will be specifically explained below with reference to examples and comparative examples. However, the present invention is not limited to these. Unless otherwise specified, "parts" means parts by weight, and "%" means % by weight. Measurement methods were as follows.

[0043] 1) OH equivalent (hydroxyl group equivalent) Using a potentiometric titrator, acetylation was carried out with 1.5 mol / L acetyl chloride in 1,4-dioxane as a solvent, and the excess acetyl chloride was decomposed with water, followed by titration with 0.5 mol / L potassium hydroxide.

[0044] 2) Vinyl equivalent: The sample was reacted with Wiess's solution (iodine monochloride solution) and left in the dark. After that, excess iodine chloride was reduced to iodine, and the iodine content was titrated with sodium thiosulfate to calculate the iodine value. The iodine value was converted to vinyl equivalent.

[0045] 3) Total chlorine: 1.0 g of sample was dissolved in 25 ml of butyl carbitol, 25 ml of 1N KOH propylene glycol solution was added, and the mixture was heated under reflux for 10 minutes. After cooling to room temperature, 100 ml of 80% acetone water was added, and the total chlorine was measured by potentiometric titration with a 0.002 N AgNO3 aqueous solution.

[0046] 4) GPC Measurement A main body (HLC-8220GPC manufactured by Tosoh Corporation) equipped with four columns (TSKgel Super Multipore HZ-N manufactured by Tosoh Corporation) in series was used, and the column temperature was set to 40°C. Tetrahydrofuran (THF) was used as the eluent at a flow rate of 0.35 mL / min, and a differential refractive index detector was used as the detector. 0.1 g of sample was dissolved in 10 mL of THF and filtered through a microfilter, and 50 μL of the solution was used as the measurement sample. Data processing was performed using GPC-8020 Model II Version 6.00 manufactured by Tosoh Corporation.

[0047] 5) Solvent solubility (precipitation temperature) 2 g of resin and 1 g of methyl ethyl ketone were weighed into a sample bottle, heated to dissolve, and then the temperature was gradually lowered in a thermostatic chamber, and the temperature in the chamber at which the resin precipitated was measured. The higher the precipitation temperature (°C), the poorer the solvent solubility.

[0048] 6) Glass Transition Point (Tg) Tg was determined using a thermomechanical measuring device (EXSTAR TMA / 7100 manufactured by SII Nanotechnology Inc.) at a temperature rise rate of 10°C / min.

[0049] 7) 5% Weight Loss Temperature (Td5), Carbon Residual Ratio The 5% weight loss temperature (Td5) was measured under a nitrogen atmosphere at a heating rate of 10°C / min using a thermogravimetric / differential thermal analyzer (EXSTAR TG / DTA7300 manufactured by SII NanoTechnology). The weight loss at 700°C was also measured and calculated as the carbon residual ratio.

[0050] 8) Thermal Conductivity The thermal conductivity was measured by the transient hot wire method using a thermal conductivity meter LFA447 manufactured by NETZSCH.

[0051] 9) Dielectric constant and dielectric loss tangent Measured in accordance with JIS C 2138. The measurement frequency was 1 GHz.

[0052] Synthesis Example 1 Into a 1000 mL four-neck flask, 73.6 g (0.60 mol) of 2,5-xylenol (structural formula below), p-Hydroxybenzaldehyde (structural formula below) 24.4 g (0.20 mol) and dissolved in 200.0 g of 2-ethoxyethanol. While cooling in an ice bath, 20.0 g of sulfuric acid was added, and then the mixture was heated at 100°C for 3 hours with stirring to allow the reaction to proceed. After the reaction, the resulting solution was reprecipitated with water, washed with water, filtered, and vacuum dried to obtain 65.0 g of trifunctional hydroxy compound a. In trifunctional hydroxy compound a, R1 to R4 in formula (3) were all methyl groups, and the hydroxyl group equivalent was 118 g / e.g.

[0053] Synthesis Example 2 The same procedure as in Synthesis Example 1 was carried out, except that 36.8 g (0.30 mol) of 2,5-xylenol and 28.2 g (0.30 mol) of phenol were used instead of 73.6 g of 2,5-xylenol, to obtain 60.8 g of trifunctional hydroxy compound b. Trifunctional hydroxy compound b was a mixture of compounds represented by formula (3) in which R1 to R4 were all hydrogen atoms or methyl groups, and had a hydroxyl group equivalent of 105 g / e.g.

[0054] (Synthesis Example 3) 102.0 g (0.60 mol) of 2-phenylphenol (structural formula below) was used instead of 73.6 g of 2,5-xylenol. The same procedure as in Synthesis Example 1 was carried out, except that the compound was replaced with a compound represented by the formula (3), where R1 to R4 were all phenyl groups, and the hydroxyl group equivalent was 149 g / e.g., to obtain 81.0 g of trifunctional hydroxy compound c.

[0055] Example 1 Into a 1000 ml four-neck flask, 59.0 g (0.17 mol) of the trifunctional hydroxy compound a obtained in Synthesis Example 1, 400 g of methyl ethyl ketone, and 91.6 g (0.60 mol) of chloromethylstyrene (structural formula below) were added. The mixture was heated to 60°C, and 33.7 g of potassium hydroxide dissolved in 101 g of methanol was added dropwise over 3 hours, followed by a reaction for an additional 6 hours. After completion of the reaction, the mixture was filtered, the solvent was distilled off, and the mixture was reprecipitated with methanol, washed with a large amount of water, and dried under reduced pressure to obtain 102.4 g of a multifunctional vinyl compound (vinyl compound A). The vinyl equivalent of vinyl compound A was 225 g / e.g., the hydroxyl equivalent was 12,000 g / e.g., and the total chlorine content was 600 ppm.

[0056] Example 2 The same procedure as in Example 1 was carried out, except that 52.5 g (0.17 mol) of trifunctional hydroxy compound b obtained in Synthesis Example 2 was used instead of trifunctional hydroxy compound a, to obtain 100.3 g of a multifunctional vinyl compound (vinyl compound B). Vinyl compound B had a vinyl equivalent of 212 g / e.g., a hydroxyl equivalent of 14,000 g / e.g., and a total chlorine content of 500 ppm.

[0057] Example 3 The same procedure as in Example 1 was carried out, except that 74.5 g (0.17 mol) of trifunctional hydroxy compound c obtained in Synthesis Example 3 was used instead of trifunctional hydroxy compound a, to obtain 121.2 g of a multifunctional vinyl compound (vinyl compound C). Vinyl compound C had a vinyl equivalent of 260 g / e.g., a hydroxyl equivalent of 11,000 g / e.g., and a total chlorine content of 800 ppm.

[0058] Comparative Example 1: 51.0 g of 1,1,1-tris(p-hydroxyphenyl)ethane (structural formula below) was used instead of the trifunctional hydroxy compound a. The same procedure as in Example 1 was carried out except that a polyfunctional vinyl compound (vinyl compound D) was used, to obtain 93.3 g. The vinyl equivalent of vinyl compound D was 214 g / eg., the hydroxyl equivalent was 7000 g / eg., and the total chlorine content was 1500 ppm.

[0059] Comparative Example 2 Into a 1000 ml four-neck flask, 40.8 g of 4,4'-bis(chloromethyl)biphenyl (structural formula below) 75.5 g of 4,4'-biphenol (structural formula below), 120 g of diethylene glycol dimethyl ether was charged, and the mixture was heated to 160 ° C. under a nitrogen stream while stirring and reacted for 10 hours. Subsequently, the temperature was raised to 70 ° C., and 280 g of diethylene glycol dimethyl ether and 129.5 g of chloromethylstyrene were added. 100.0 g of 48% potassium hydroxide was added dropwise to the mixture. Gas chromatography confirmed that there was no residual chloromethylstyrene, and the solvent was recovered under reduced pressure. The resulting resin was dissolved in toluene, neutralized, and washed with water to obtain a multifunctional vinyl resin g (vinyl resin E). The vinyl equivalent of the resulting vinyl resin E was 256 g / eq., the hydroxyl equivalent was 1500 g / eq., and the total chlorine was 1270 ppm.

[0060] Comparative Example 3 Into a 1000 ml four-neck flask, 50.0 g of dihydroxydiphenylmethane (an isomer mixture consisting of 36.2% 4,4'-dihydroxydiphenylmethane (structural formula below), 46.6% 2,4'-dihydroxydiphenylmethane, and 17.2% 2,2'-dihydroxydiphenylmethane) was added. 400 g of methyl ethyl ketone and 80.1 g of chloromethylstyrene were added, the mixture was heated to 60°C, and 29.5 g of potassium hydroxide dissolved in 88 g of methanol was added dropwise over 3 hours, followed by a reaction time of 6 hours. After the reaction was completed, the mixture was filtered, the solvent was removed by distillation, and the mixture was reprecipitated with methanol, washed with a large amount of water, and dried under reduced pressure to obtain 95.4 g of a multifunctional vinyl resin (Vinyl Resin F). The vinyl equivalent of Vinyl Resin F was 217 g / e.g., the hydroxyl equivalent was 17,000 g / e.g., and the total chlorine content was 400 ppm.

[0061] Examples 4-6, Comparative Examples 4-7 As the polyfunctional vinyl compound, vinyl compounds A-F obtained in Examples 1-3 and Comparative Examples 1-3 and vinyl resin G (OPE-2ST: manufactured by Mitsubishi Gas Chemical Company, Inc., vinyl group equivalent: 590.0 g / eq, number average molecular weight 1187) were used, and the organic peroxide Perbutyl P (manufactured by NOF Corporation) was used as the curing accelerator (radical polymerization initiator), and Adeka Stab AO-60 (manufactured by ADEKA Corporation) was used as the antioxidant. These were mixed in the blending ratios shown in Table 1 and dissolved in a solvent to form a homogeneous composition. This composition was applied to a PET film and dried at 130 ° C. for 5 minutes to obtain a resin composition. The composition removed from the PET film was sandwiched between mirror plates and cured under reduced pressure at 130 ° C. for 15 minutes and at 210 ° C. for 80 minutes while applying a pressure of 2 MPa. The properties of the resulting cured product are shown in Table 1.

[0062]

[0063] The polyfunctional vinyl compounds of the Examples exhibited excellent physical properties such as high thermal conductivity, low dielectric constant and low dielectric loss tangent, as compared with the Comparative Examples.

[0064] The polyfunctional vinyl compound of the present invention is useful as an electronic material for high-speed communication devices, as it allows heat generated from electronic components and wiring to easily escape and reduces signal loss.

Claims

Claim 1 A polyfunctional vinyl compound represented by the following general formula (1). 【Chemical 1】 In formula (1), R1 to R4 each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms. However, at least one of R1 to R4 represents an alkyl group or an aromatic group. Claim 2 The polyfunctional vinyl compound according to claim 1, wherein at least one of R1 to R4 is a methyl group or a phenyl group. Claim 3 A polyfunctional vinyl composition containing, as essential components, the polyfunctional vinyl compound according to claim 1 or 2 and a radical polymerization initiator. Claim 4 A polyfunctional vinyl cured product obtained by curing the polyfunctional vinyl composition according to claim 3.

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