Polyfunctional vinyl compound, composition thereof, and cured product

Abstract

Provided is a vinyl compound that: has excellent solvent solubility; produces a cured product having excellent heat resistance, pyrolysis stability, thermal conductivity, low dielectric constant, low dielectric tangent, and fire resistance; and is useful for sealing electric and electronic parts and as a circuit board material.　The polyfunctional vinyl compound is represented by general formula (1).　In formula (1), R1 through R4 are each independently a hydrogen atom or a C1-6 alkoxy group, where at least one thereof is an alkoxy group.

Description

Polyfunctional vinyl compound, composition thereof, and cured product

[0001] The present invention relates to a vinyl compound that can be made from plant-derived raw materials and is also carbon-neutral. More specifically, the present invention relates to a polyfunctional vinyl compound that has excellent solvent solubility and is useful as an insulating material for electric and electronic components such as semiconductor encapsulation, laminates, and heat dissipation substrates; a composition thereof; and a resin cured 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 data 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 capable of reducing dielectric loss, and for printed circuit board applications, curable resins that can be multilayered are also required. Furthermore, electronic computing components that process such large amounts of data generate a large amount of heat, and heat accumulation can cause problems such as a decrease in the processing speed of the electronic computing components. To address this issue, various cooling techniques for printed circuit boards using heat sinks and other methods have been proposed, including incorporating heat transfer components such as copper coins and copper inlays (Patent Document 1) and incorporating specially shaped fillers (Patent Document 2). However, these methods are undesirable because they increase the weight and size of the device.

[0003] In encapsulant compositions, methods for increasing thermal conductivity have been adopted 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 inorganic fillers increases viscosity during molding, reducing fluidity and impairing moldability. Therefore, there are limitations to simply increasing the content of inorganic fillers.

[0004] 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 must be applied to orient the molecules, which poses significant equipment limitations for widespread industrial use.

[0005] Meanwhile, in the design of thermosetting plastics, materials development that actively uses biomass materials as raw materials is actively underway with the aim of conserving petroleum resources and reducing carbon dioxide emissions. For example, to form thermosetting plastics, it is known to use plant-derived raw materials as curing agents and perform a curing reaction to obtain a cured product. Many of these biomass materials are aliphatic compounds obtained by modifying sugar-derived alcohols or vegetable oils. A specific example of the use of aliphatic compounds modified from vegetable oils is a method of producing a cured product using epoxidized vegetable oils in which double bonds are modified with epoxy groups (Patent Document 7). Alternatively, it is known to obtain a cured product using a biomass material containing a benzene ring, such as lignin, as a curing agent (Patent Document 8). Lignin is a wood component and a polymeric phenolic compound. It is known that the use of such lignin in a curing reaction to produce a cured product can be expected to exhibit high heat resistance.

[0006] However, the cured product formed by the method of Patent Document 7 had a very low glass transition temperature, sometimes dropping to around 5°C. This meant that it could not be used as electronic materials or building structural components, which require high heat resistance, and its applications were severely limited. Furthermore, the cured product obtained from biomass materials containing benzene rings, as in Patent Document 8, had a large molecular weight and strong intermolecular hydrogen bonds, so it had no melting point and was difficult to dissolve in solvents. Therefore, while highly heat-resistant thermosetting plastics could indeed be obtained, moldability was impaired, making it difficult to use as a thermosetting plastic raw material.

[0007] Japanese Patent Application Laid-Open No. 2009-170493 International Publication No. 2013 / 100172 Japanese Patent Application Laid-Open No. 11-147936 Japanese Patent Application Laid-Open No. 2002-309067 Japanese Patent Application Laid-Open No. 11-323162 Japanese Patent Application Laid-Open No. 9-118673 Japanese Patent Application Laid-Open No. 2006-241331 Japanese Patent Application Laid-Open No. 2009-263549

[0008] An object of the present invention is to provide a vinyl composition that is useful for sealing electric and electronic components, circuit board materials, etc., and that gives a cured product that has excellent solvent solubility as well as excellent heat resistance, thermal decomposition stability, thermal conductivity, low dielectric constant, low dielectric dissipation factor, and flame retardancy, and to provide the cured product. Another object is to provide a carbon-neutral 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 an alkoxy group having 1 to 6 carbon atoms, and at least one is an alkoxy group.

[0011] The polyfunctional vinyl compound described above is preferably made from a plant-derived phenolic compound.

[0012] The present invention relates to a polyfunctional vinyl composition containing the above polyfunctional vinyl compound and a radical polymerization initiator as essential components, and to a polyfunctional vinyl cured product obtained by curing this polyfunctional vinyl resin 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, and adhesion. 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 electrical and electronic components, circuit board materials, and the like. Furthermore, since the compound can be obtained from plant-derived raw materials, it is suitable as a material that conserves petroleum resources and reduces carbon dioxide emissions.

[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 each independently represent a hydrogen atom or an alkoxy group having 1 to 6 carbon atoms, with at least one being an alkoxy group. From the viewpoint of solvent solubility, the greater the number of alkoxy groups, the better. From the viewpoint of thermal conductivity, the alkoxy group preferably has 2 or less carbon atoms, and a methoxy group or an ethoxy group is preferred. A more preferred structure is one in which R1 to R3 are methoxy groups. In particular, a structure in which at least one of R1 to R4 is a methoxy group can be obtained from plant-derived materials.

[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 (number average) 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.

[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] An example of a monohydric phenol compound derived from a plant is 2-methoxyphenol (also known as baguayacol). Examples of monohydric phenols having an alkoxy group include 3-methoxyphenol, 4-methoxyphenol, 2-ethoxyphenol, 3-ethoxyphenol, and 4-ethoxyphenol. Other monohydric phenol compounds include, for example, 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. These phenol compounds can also be used in combination.

[0024] Examples of plant-derived aromatic aldehydes include 4-hydroxy-3-methoxybenzaldehyde (also known as vanillin) and 3,5-dimethoxy-4-hydroxybenzaldehyde (also known as syringaldehyde), and examples of other hydroxybenzaldehydes having an alkoxy group include 4-hydroxy-3-ethoxybenzaldehyde and 4-hydroxy-2-methoxybenzaldehyde. Examples of other aromatic aldehydes include hydroxybenzaldehydes such as 2-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, and 4-hydroxybenzaldehyde; alkoxybenzaldehydes such as 4-methoxybenzaldehyde, 3-methoxybenzaldehyde, 2-methoxybenzaldehyde, 4-ethoxybenzaldehyde, 3-ethoxybenzaldehyde, and 2-ethoxybenzaldehyde; and 2-hydroxy-4-methylbenzaldehyde, and these can also be used in combination.

[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 0.5 to 1.5 equivalents, more preferably 0.8 to 1.2 equivalents, of the 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 the 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 alone, but it is also suitable to use it as a polyfunctional vinyl composition containing various additives. In particular, to accelerate curing, a radical polymerization initiator such as an azo compound or an organic peroxide can be added to the composition to effect curing. The amount of the radical polymerization initiator is, for example, 0.01 to 3.0 parts by weight, preferably 0.05 to 1.0 parts by weight, per 100 parts by weight of the polyfunctional vinyl compound. An antioxidant may also be added, and the amount is, for example, 0.01 to 3.0 parts by weight, preferably 0.03 to 0.10 parts by weight, per 100 parts by weight of the polyfunctional vinyl compound.

[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] To increase thermal conductivity, inorganic fillers such as glass cloth, carbon fiber, alumina, and boron nitride may be blended. Polyfunctional vinyl compositions blended with inorganic fillers are suitable for semiconductor encapsulation and circuit boards. In the case of semiconductor encapsulation, the blending amount of inorganic filler is, for example, 50% by weight or more, preferably 80 to 95% by weight. In the case of circuit boards, the blending amount of inorganic filler is, for example, 50% by weight or more, preferably 70 to 90% by weight.

[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 a 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 (Tosoh Corporation, HLC-8220GPC) equipped with four columns (Tosoh Corporation, TSKgel SuperMultipore HZ-N) 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 Tosoh Corporation's GPC-8020 Model II Version 6.00.

[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, 74.5 g (0.60 mol) of 2-methoxyphenol (structural formula below), 4-hydroxy-3-methoxybenzaldehyde (structural formula below) 30.4 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 R3 are all methoxy groups and R4 is a hydrogen atom in formula (3). The hydroxyl group equivalent was 128 g / e.g.

[0053] (Synthesis Example 2) 36.5 g (0.20 mol) of 3,5-dimethoxy-4-hydroxybenzaldehyde was used instead of 73.6 g of 4-hydroxy-3-methoxybenzaldehyde. The same procedure as in Synthesis Example 1 was carried out except that the following compound was used: (1) Trifunctional hydroxy compound b (68.5 g) was obtained. In trifunctional hydroxy compound b, R1 to R4 in formula (3) were all methoxy groups, and the hydroxyl group equivalent was 137 g / e.g.

[0054] Example 1 Into a 1000 ml four-neck flask, 38.4 g (0.30 equivalents) of the trifunctional hydroxy compound a obtained in Synthesis Example 1, 500 g of methyl ethyl ketone, and 54.9 g (0.36 equivalents) of chloromethylstyrene (structural formula below) were added. The mixture was heated to 60°C, and 20.2 g of potassium hydroxide dissolved in 60.6 g of methanol was added dropwise over 3 hours, followed by a reaction for an additional 6 hours. After the reaction was completed, 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 62.6 g of a multifunctional vinyl compound (vinyl compound A). The vinyl equivalent of vinyl compound A was 244 g / eg., the hydroxyl equivalent was 15,000 g / eg., and the total chlorine content was 500 ppm.

[0055] Example 2 The same procedure as in Example 1 was carried out, except that 41.1 g (0.30 equivalents) of trifunctional hydroxy compound b obtained in Synthesis Example 2 was used instead of trifunctional hydroxy compound a, to obtain 56.7 g of a multifunctional vinyl compound (vinyl compound B). Vinyl compound B had a vinyl equivalent of 252 g / e.g., a hydroxyl equivalent of 14,000 g / e.g., and a total chlorine content of 600 ppm.

[0056] Comparative Example 1 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 172 g of a multifunctional vinyl resin (vinyl resin C). The vinyl equivalent of the resulting vinyl resin C was 256 g / eq., the hydroxyl equivalent was 1500 g / eq., and the total chlorine was 1270 ppm.

[0057] (Comparative Example 2) 30.6 g (0.30 equivalents) of 1,1,1-tris(p-hydroxyphenyl)ethane (structural formula below) was used instead of polyhydric hydroxy resin a. The same procedure as in Example 1 was carried out except that 58.9 g of a vinyl compound (vinyl compound D) was obtained. 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.

[0058] (Comparative Example 3) Into a 1000 ml four-neck flask, 50.0 g of dihydroxydiphenylmethane (4,4'-dihydroxydiphenylmethane (structural formula below): 36.2%, 2,4'-dihydroxydiphenylmethane: 46.6%, 2,2'-dihydroxydiphenylmethane: 17.2%), 400 g of methyl ethyl ketone and 80.1 g of chloromethylstyrene were added, and the mixture was heated to 60°C. 29.5 g of potassium hydroxide dissolved in 88 g of methanol was added dropwise over 3 hours, and the reaction was continued for another 6 hours. After the reaction was completed, 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 95.4 g of a vinyl compound (vinyl compound E). The vinyl equivalent of vinyl compound E was 217 g / eg., the hydroxyl equivalent was 17,000 g / eg., and the total chlorine content was 400 ppm.

[0059] Examples 3-4, Comparative Examples 4-7 As the polyfunctional vinyl compound, vinyl compounds A-E obtained in Examples 1-2 and Comparative Examples 1-3 and vinyl resin F (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 radical polymerization initiator, and Adeka Stab AO-60 (manufactured by ADEKA Corporation) was used as the antioxidant. These were mixed in the formulation 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.

[0060]

[0061] 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.

[0062] The polyfunctional vinyl compound of the present invention is useful as an electronic material for high-speed communication devices, as it allows heat to escape easily from electronic components and wiring, resulting in little signal loss. Furthermore, since it can be obtained from plant-derived raw materials, it is suitable as a material that saves petroleum resources and reduces carbon dioxide emissions.

Claims

1. A polyfunctional vinyl compound represented by the following general formula (1): In formula (1), R1 to R4 each independently represent a hydrogen atom or an alkoxy group having 1 to 6 carbon atoms, and at least one is an alkoxy group.

2. The polyfunctional vinyl compound according to claim 1, which is made from a plant-derived phenolic compound.

3. A polyfunctional vinyl composition comprising, as essential components, the vinyl compound according to claim 1 or 2 and a radical polymerization initiator.

4. A cured polyfunctional vinyl product obtained by curing the polyfunctional vinyl composition according to claim 3.

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