JP6667126B2 - Cyanate ester compound, curable resin composition containing the compound, and cured product thereof - Google Patents

Description

  The present invention relates to a cyanate compound, a curable resin composition containing the compound, and a cured product thereof.

  The cyanate ester compound forms a triazine ring upon curing and, due to its high heat resistance and excellent electrical properties, can be used for various functional polymer materials such as structural composite materials, adhesives, electrical insulating materials, and electrical and electronic parts. It is widely used as a raw material. However, in recent years, with the advancement of required performance in these application fields, various physical properties required as a functional polymer material have become more and more severe. Examples of such physical properties include flame retardancy, heat resistance, low coefficient of thermal expansion, low water absorption, low dielectric constant, low dielectric loss tangent, weather resistance, chemical resistance, and high fracture toughness. However, to date, these required physical properties have not always been satisfied.

  For example, in the field of semiconductor encapsulating materials, studies for replacing a semiconductor element with a wide gap semiconductor such as silicon carbide (SiC) from silicon (Si) have been actively conducted in order to reduce power loss (energy saving). Since the SiC semiconductor is more chemically stable than the Si semiconductor, it can operate at a high temperature of over 200 ° C. and is expected to be downsized as a device. Along with this, a composition containing a functional polymer material used for an encapsulating material is provided with heat resistance (high glass transition temperature), low thermal expansion, and heat resistance under high temperature for a long time (hereinafter, long term). Heat resistance) is required.

  In addition, from the viewpoint of filling the sealing material into every corner of the object to be sealed (moldability), it is also required that the composition containing the functional polymer material used for the sealing material has a low viscosity. Have been.

  As an example of obtaining a cured product of a single cyanate ester compound having low viscosity and heat resistance, a bifunctional cyanatophenyl type in which hydrogen of a methylene group connecting cyanatophenyl groups is substituted with a specific alkyl group is provided. It has been proposed to use a cyanate compound (1,1-bis (4-cyanatophenyl) isobutane) (see Patent Document 1). However, Patent Document 1 has no description about long-term heat resistance.

  As a composition using a cyanate ester compound having heat resistance and heat resistance at a high temperature for a long time, a composition containing a novolak-type cyanate, a novolak-type phenol resin, and an inorganic filler has been proposed (Patent Document 2). ). However, the long-term heat resistance test in Patent Document 2 is about 50 hours (250 ° C.), which is not sufficient as a test time.

WO 2012/057144 Pamphlet JP 2013-053218 A

Until now, a practical cured product of a single cyanate compound having a high degree of heat resistance and long-term heat resistance using a low-viscosity cyanate compound excellent in moldability has not been obtained.
An object of the present invention is to provide a novel cyanate ester compound, a curable resin composition containing the compound, and the like, which have excellent moldability and can provide a cured product having excellent heat resistance and long-term heat resistance. It is to provide.

  The present inventors have found that a cyanate compound obtained by cyanating an asymmetric phenol novolak resin has excellent moldability and excellent handleability, and a curable resin using such a cyanate compound. The inventors have found that the composition can realize a cured product having excellent heat resistance and long-term heat resistance, and have reached the present invention. That is, the present invention is as follows.

  1. A cyanate compound obtained by cyanating an asymmetric phenol novolak resin.

2. Having a structure represented by the following general formula (1): 3. The cyanate ester compound according to item 1.
(In the formula, n represents 1.04 to 4 as an average value.)

  3. The asymmetric phenol novolak resin is obtained by reacting acetaldehyde and phenol in the presence of an acidic catalyst. Or 2. 3. The cyanate ester compound according to item 1.

  4. 1. The weight average molecular weight Mw is 270 to 700; ~ 3. The cyanate ester compound according to any one of the above.

  5.1. ~ 4. A curable resin composition comprising the cyanate ester compound according to any one of the above.

  6.1. ~ 4. Selected from the group consisting of cyanate ester compounds other than the cyanate ester compound according to any one of the above, a maleimide compound, a phenol resin, an epoxy resin, an oxetane resin, a benzoxazine compound and a compound having a polymerizable unsaturated group. 4. at least one further containing 3. The curable resin composition according to item 1.

  7.5. Or 6. A cured product obtained by curing the curable resin composition according to the above.

  8.5. Or 6. A prepreg for a structural material, obtained by impregnating or applying a curable resin composition according to 1 above to a substrate and drying the substrate.

  9.5. Or 6. A sealing material, comprising the curable resin composition according to item 1.

  10.5. Or 6. A fiber-reinforced composite material, comprising the curable resin composition according to item 1.

  11.5. Or 6. An adhesive, comprising the curable resin composition according to item 1.

2 is a GPC chart of the cyanate ester compound ECN-1-M obtained in Example 1. 2 is an FT-IR chart of the asymmetric phenol novolak resin 1 and the cyanate ester compound ECN-1-M obtained in Example 1. 5 is a GPC chart of the cyanate ester compound ECN-2-M obtained in Example 2. 6 is a GPC chart of the cyanate ester compound ECN-3-M obtained in Example 3. 9 is a GPC chart of the cyanate ester compound ECN-4-M obtained in Example 4. 7 is a GPC chart of the cyanate ester compound PN-1-CN obtained in Comparative Example 1. 4 is an FT-IR chart of the phenol novolak resin 1 used in Comparative Example 1 and the cyanate ester compound PN-1-CN obtained in Comparative Example 1. 9 is a GPC chart of the cyanate ester compound PN-2-CN obtained in Comparative Example 2.

  The present invention is a cyanate compound obtained by cyanating an asymmetric phenol novolak resin, and a curable resin composition containing the cyanate compound.

  In another aspect of the present invention, a cured product obtained by curing the curable resin composition, a sealing material containing the curable resin composition, a fiber-reinforced composite material, and an adhesive are also provided. You.

<Asymmetric phenol novolak resin>
The asymmetric phenol novolak resin as a raw material of the cyanate compound of the present invention,
It is not particularly limited as long as hydrogen on one side of the methylene group connecting the hydroxyphenyl groups is substituted with another group and is asymmetric, and it can be obtained by reacting acetaldehyde and phenol in the presence of an acidic catalyst.

  The acidic catalyst used in the reaction of acetaldehyde and phenol can be appropriately selected from well-known inorganic acids and organic acids, and examples thereof include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid, hydrofluoric acid, and oxalic acid. Acid, malonic acid, succinic acid, adipic acid, sebacic acid, citric acid, fumaric acid, maleic acid, formic acid, p-toluenesulfonic acid, methanesulfonic acid, trifluoroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoromethanesulfonic acid, Organic acids such as benzenesulfonic acid, naphthalenesulfonic acid, and naphthalenedisulfonic acid, and solid acids such as silicotungstic acid, phosphotungstic acid, silicomolybdic acid or phosphomolybdic acid, and ion exchange resin. Among these, p-toluenesulfonic acid, sulfuric acid, hydrochloric acid, and phosphoric acid are preferable from the viewpoint of production. These can be used alone or in combination of two or more.

  The amount of the acidic catalyst to be used is generally 0.001 to 0.1 mol per 1 mol of acetaldehyde.

  In the reaction of acetaldehyde and phenol, a co-catalyst can be used if necessary. Examples of the cocatalyst include mercaptans such as methanethiol, ethanethiol, propionthiol, butanethiol, thiophenol, mercaptopropionic acid, methoxybutyl mercaptopropionate, octyl mercaptopropionate, and tridecyl mercaptopropionate. Among these, mercaptopropionic acid is preferred from the viewpoint of production.

  In the reaction between acetaldehyde and phenol, a solvent inert to the reaction can be used, if necessary. Examples of the solvent include organic solvents such as alcohol solvents such as methanol, ethanol, propanol and isopropanol, and aromatic hydrocarbon solvents such as toluene and xylene. These can be used alone or in combination of two or more. When a solvent is used, its amount is usually 5 to 500 parts by mass, preferably 10 to 300 parts by mass, per 100 parts by mass of phenol.

  The reaction temperature in the above reaction is -10 to 200C, preferably 0 to 180C.

  The reaction time in the above reaction is 1 to 200 hours, preferably 5 to 100 hours.

  In the above reaction, the amount of phenol used is 1.5 to 20 mol, preferably 1.8 to 10 mol, per 1 mol of acetaldehyde.

  The reaction is carried out by adding an acidic catalyst to a mixture of acetaldehyde and phenol (a solvent if necessary) and heating. Acetaldehyde may be gradually added to a place where a mixture of phenol and a catalyst (solvent if necessary) is being heated. The reaction may be performed with stirring, in air or in an inert atmosphere (such as nitrogen, helium, or argon), or may be performed at normal pressure or under pressure. The progress of the reaction can be confirmed (or traced) by high performance liquid chromatography (HPLC), thin layer chromatography (TLC), or the like.

  The reaction mixture after the completion of the reaction contains unreacted acetaldehyde, unreacted phenol, acidic catalyst, by-products, and the like. Therefore, separation and purification may be performed by a conventional method, for example, a separation means such as neutralization, washing, filtration, concentration, extraction, crystallization, recrystallization, and column chromatography, or a combination of these.

  The asymmetric phenol novolak resin obtained by the above production method can be represented by the following general formula (2) (although not particularly limited).

(In the formula, n represents 1.04 to 4 as an average value.)

<Cyanate compound>
The cyanate compound of the present invention can be obtained by cyanating a hydroxy group of an asymmetric phenol novolak resin. The cyanation method is not particularly limited, and a known method can be applied. Specifically, a method in which an asymmetric phenol novolak resin and a cyanogen halide are reacted in a solvent in the presence of a basic compound, in a solvent, in the presence of a base, the cyanogen halide is always present in excess of the base. Thus, a method of reacting an asymmetric phenol novolak resin with a cyanogen halide (US Pat. No. 3,553,244), or using a tertiary amine as a base in excess of a cyanogen halide in the presence of a solvent A method of adding a tertiary amine to an asymmetric phenol novolak resin and then dropping a halogenated cyanide, or simultaneously adding and dropping a halogenated cyanide and a tertiary amine (Japanese Patent No. 3319061). To react a reactive phenol novolak resin, trialkylamine and cyanogen halide (Patent 905559), a method in which a tert-ammonium halide by-produced when a non-aqueous phenol novolak resin is reacted with a cyanogen halide in a non-aqueous solution in the presence of a tert-amine is treated with a cation and anion exchange pair. (Japanese Patent No. 4055210), a tertiary amine and a cyanogen halide are simultaneously added to an asymmetric phenol novolak resin in the presence of a solvent capable of separating with water, and then reacted. A method of precipitating and purifying the resulting solution using a secondary or tertiary alcohol or a poor hydrocarbon solvent (Japanese Patent No. 2991054), further comprising an asymmetric phenol novolak resin, a cyanogen halide, and a tertiary amine. In a two-phase solvent of water and an organic solvent under acidic conditions (Japanese Patent No. 5026727). Etc., it is possible to obtain a cyanate ester compound of the present invention.

As described above, when using a method of reacting an asymmetric phenol novolak resin and a cyanogen halide in a solvent in the presence of a basic compound, the asymmetric phenol novolak resin that is a reaction substrate is treated with a cyanogen halide solution and a basic After previously dissolving in any of the compound solutions, the cyanogen halide solution is brought into contact with the basic compound solution.
The method of contacting the cyanogen halide solution with the basic compound solution (contact method) includes (A) a method of pouring the basic compound solution into the cyanogen halide solution mixed and stirred, and (B) a method of stirring and mixing. A method in which a cyanogen halide solution is poured into the basic compound solution thus obtained, a method (C) in which a cyanogen halide solution and a basic compound solution are continuously and alternately or simultaneously supplied, and the like.
Among the methods (A), (B) and (C), the method (A) is preferable because a side reaction can be suppressed and a higher purity cyanate ester compound can be obtained in a higher yield.
The method for contacting the cyanogen halide solution with the basic compound solution may be any of a semi-batch type or a continuous flow type.
In particular, when the method (A) is used, the reaction can be completed without leaving the hydroxy group of the asymmetric phenol novolak resin, and a higher purity cyanate ester compound can be obtained in a higher yield. Therefore, it is preferable to divide and pour the basic compound. The number of divisions is not particularly limited, but is preferably 1 to 5 times. The type of the basic compound may be the same or different for each division.

  The cyanogen halide used in the present invention includes cyanogen chloride and cyanogen bromide. As the cyanogen halide, a cyanogen halide obtained by a known production method such as a method of reacting hydrogen cyanide or metal cyanide with halogen may be used, or a commercially available product may be used. Further, a reaction solution containing cyanogen halide obtained by reacting hydrogen cyanide or metal cyanide with halogen can be used as it is.

The amount of the cyanogen halide used in the cyanating step of the present invention relative to the asymmetric phenol novolak resin is 0.5 to 5 mol, preferably 1.0 to 3.5 mol, per 1 mol of the hydroxy group of the asymmetric phenol novolak resin. Is a mole.
The reason is to increase the yield of the cyanate ester compound without leaving unreacted asymmetric phenol novolak resin.

  Examples of the solvent used for the cyanogen halide solution include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and cyclopentanone; aliphatic hydrocarbon solvents such as n-hexane, cyclohexane, and isooctane; benzene, toluene, and xylene. Aromatic hydrocarbon solvents such as diethyl ether, dimethyl cellosolve, diglyme, ether solvents such as tetrahydrofuran, methyl tetrahydrofuran, dioxane, tetraethylene glycol dimethyl ether, dichloromethane, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, chlorobenzene, bromo Halogenated hydrocarbon solvents such as benzene, methanol, ethanol, isopropanol, methylsolve, propylene glycol Alcoholic solvents such as methyl ether, aprotic polar solvents such as N, N-dimethylformamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidone, dimethylsulfoxide; nitrile solvents such as acetonitrile and benzonitrile; Examples include nitro solvents such as nitromethane and nitrobenzene, ester solvents such as ethyl acetate and ethyl benzoate, and aqueous solvents. These can be used alone or in combination of two or more in accordance with the reaction substrate.

  As the basic compound used in the cyanation step of the present invention, any of organic and inorganic bases can be used, and one of them can be used alone or in combination of two or more.

  As the organic base, in particular, trimethylamine, triethylamine, tri-n-butylamine, triamylamine, diisopropylethylamine, diethyl-n-butylamine, methyldi-n-butylamine, methylethyl-n-butylamine, dodecyldimethylamine, tribenzylamine, Triethanolamine, N, N-dimethylaniline, N, N-diethylaniline, diphenylmethylamine, pyridine, diethylcyclohexylamine, tricyclohexylamine, 1,4-diazabicyclo [2.2.2] octane, 1,8- Tertiary amines such as diazabicyclo [5.4.0] -7-undecene and 1,5-diazabicyclo [4.3.0] -5-nonene are preferred. Among these, trimethylamine, triethylamine, tri-n-butylamine, and diisopropylethylamine are more preferable, and triethylamine is particularly preferable, since the desired product can be obtained in good yield.

The amount of the organic base to be used is preferably 0.1 to 8 mol, more preferably 1.0 to 3.5 mol, per 1 mol of the hydroxy group of the asymmetric phenol novolak resin.
The reason is to increase the yield of the cyanate ester compound without leaving unreacted asymmetric phenol novolak resin.

  As the inorganic base, an alkali metal hydroxide is preferable. Examples of the alkali metal hydroxide include, but are not particularly limited to, sodium hydroxide, potassium hydroxide, lithium hydroxide and the like generally used in industry. Sodium hydroxide is particularly preferred because it can be obtained at low cost.

The amount of the inorganic base to be used is preferably 1.0 to 5.0 mol, more preferably 1.0 to 3.5 mol, per 1 mol of the hydroxy group of the asymmetric phenol novolak resin.
The reason is to increase the yield of the cyanate ester compound without leaving unreacted asymmetric phenol novolak resin.

  In the reaction of the present invention, the basic compound can be used as a solution dissolved in a solvent as described above. As the solvent, an organic solvent or water can be used.

The amount of the solvent used for the basic compound solution is preferably 0.1 to 100 parts by mass, based on 1 part by mass of the asymmetric phenol novolak resin, when the asymmetric phenol novolak resin is dissolved in the basic compound solution. Preferably it is 0.5 to 50 parts by mass.
When the asymmetric phenol novolak resin is not dissolved in the basic compound solution, the amount of the solvent used is preferably 0.1 to 100 parts by mass, more preferably 0.25 to 50 parts by mass, relative to 1 part by mass of the basic compound. Department.

  The organic solvent for dissolving the basic compound is preferably used when the basic compound is an organic base, for example, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and aromatic hydrocarbon solvents such as benzene, toluene and xylene. Solvents, ether solvents such as diethyl ether, dimethyl cellosolve, diglyme, tetrahydrofuran, methyltetrahydrofuran, dioxane, tetraethylene glycol dimethyl ether; halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, chlorobenzene, bromobenzene Alcohols such as methanol, ethanol, isopropanol, methylsolve, and propylene glycol monomethyl ether; N, N-dimethyl Aprotic polar solvents such as lumamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidone and dimethylsulfoxide; nitrile solvents such as acetonitrile and benzonitrile; nitro solvents such as nitromethane and nitrobenzene; ethyl acetate; benzoic acid Examples thereof include ester solvents such as ethyl acid and aliphatic hydrocarbon solvents such as cyclohexane. The organic solvent can be appropriately selected according to the basic compound, the reaction substrate, and the solvent used for the reaction. These can be used alone or in combination of two or more.

  Water in which the basic compound is dissolved is preferably used when the basic compound is an inorganic base, and is not particularly limited, and may be tap water, distilled water, or deionized water. . From the viewpoint of efficiently obtaining the desired cyanate ester compound, distilled water and deionized water containing less impurities are preferable.

  When the solvent used for the basic compound solution is water, it is preferable to use a catalytic amount of an organic base as a surfactant from the viewpoint of ensuring a more sufficient reaction rate. Among them, tertiary amines which cause few side reactions are preferable. The tertiary amine may be any of an alkylamine, an arylamine and a cycloalkylamine, and specifically, trimethylamine, triethylamine, tri-n-butylamine, triamylamine, diisopropylethylamine, diethyl-n-butylamine, methyldiamine -N-butylamine, methylethyl-n-butylamine, dodecyldimethylamine, tribenzylamine, triethanolamine, N, N-dimethylaniline, N, N-diethylaniline, diphenylmethylamine, pyridine, diethylcyclohexylamine, tricyclohexyl Amine, 1,4-diazabicyclo [2.2.2] octane, 1,8-diazabicyclo [5.4.0] -7-undecene, and 1,5-diazabicyclo [4.3.0] -5- Nonen That. Among these, trimethylamine, triethylamine, tri-n-butylamine, and diisopropylethylamine are more preferable, and triethylamine is particularly preferable, from the viewpoint of solubility in water and the viewpoint of obtaining the target product with higher yield. These may be used alone or in combination of two or more.

  The total amount of the solvent used in the cyanation step of the present invention is preferably 2.5 to 100 parts by mass with respect to 1 part by mass of the asymmetric phenol novolak resin, whereby the asymmetric phenol novolak resin is more uniformly dissolved, and It is preferable from the viewpoint of more efficiently producing an acid ester compound.

In the cyanation step of the present invention, the pH of the reaction solution is not particularly limited, but it is preferable to carry out the reaction while maintaining the state where the pH is less than 7. By controlling the pH to less than 7, generation of by-products such as a polymer of imide carbonate and a cyanate ester compound is suppressed, and a cyanate ester compound can be efficiently produced. In order to maintain the pH of the reaction solution below 7, a method of adding an acid to the reaction solution is preferable. An acid is added to the cyanogen cyanide solution immediately before the cyanation step, and an acid is added to the reaction system while appropriately measuring the pH of the reaction solution with a pH meter during the reaction to maintain a state of less than pH 7. It is more preferable to do so.
Examples of the acid used at that time include inorganic acids such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid, and organic acids such as acetic acid, lactic acid, and propionic acid.

  When the reaction temperature in the cyanation step of the present invention is imidcarbonate, a polymer of a cyanate ester compound, and by-products such as dialkylcyanoamide, coagulation of the reaction solution, and when cyanogen chloride is used as cyanogen halide, From the viewpoint of suppressing volatilization of cyanogen chloride, the temperature is preferably −20 to + 50 ° C., more preferably −15 to 15 ° C., and still more preferably −10 to 10 ° C.

The reaction pressure in the cyanation step of the present invention may be normal pressure or pressurization. If necessary, an inert gas such as nitrogen, helium, or argon may be passed through the reaction system.
The reaction time is not particularly limited, but the pouring time when the contact method is (A) and (B) and the contact time when the contact method is (C) are preferably 1 minute to 20 hours, and 3 minutes to 10 hours. Is more preferred. Further, it is preferable to stir while maintaining the reaction temperature for 10 minutes to 10 hours thereafter.

  By setting the reaction conditions in the above range, the intended cyanate compound can be obtained more economically and more industrially.

  The progress of the reaction in the cyanation step can be analyzed by liquid chromatography or IR spectroscopy. Volatile components such as dicyan and dialkylcyanoamide by-produced can be analyzed by gas chromatography.

  After completion of the reaction, the desired cyanate ester compound can be isolated by performing ordinary post-treatment operations and, if desired, separation / purification operations. Specifically, an organic solvent phase containing a cyanate compound is separated from the reaction solution, and after washing with water, concentration, precipitation or crystallization, or after washing with water, solvent replacement may be performed. At the time of washing, a method using an acidic aqueous solution such as dilute hydrochloric acid can be employed to remove excess amines. In order to remove water from the sufficiently washed reaction solution, the reaction solution can be dried by a general method using sodium sulfate, magnesium sulfate, or the like. At the time of concentration and solvent replacement, in order to suppress polymerization of the cyanate ester compound, the organic solvent is distilled off by heating to 90 ° C. or less under reduced pressure. At the time of precipitation or crystallization, a solvent having low solubility can be used. For example, a method in which an ether-based solvent, a hydrocarbon-based solvent such as hexane, or an alcohol-based solvent is dropped into the reaction solution or reversely poured into the reaction solution can be employed. In order to wash the obtained crude product, a method of washing a concentrate or precipitated crystal of the reaction solution with a hydrocarbon solvent such as an ether solvent or hexane, or an alcohol solvent can be adopted. . After the crystals obtained by concentrating the reaction solution are dissolved again, the crystals can be recrystallized. The crystallization may be performed by simply concentrating or cooling the reaction solution.

  The cyanate compound obtained by the above production method (although not particularly limited) can be represented by the following general formula (1).

(In the formula, n represents 1.04 to 4 as an average value.)

  The cyanate compound represented by the general formula (1) is a mixture of components having different values of n, and n is 1.04 to 4 as an average value. Among them, it is preferably from 1.04 to 3.7, and more preferably from 1.04 to 3.35. The average value of n referred to in this specification refers to a number average value.

  The weight average molecular weight Mw of the cyanate ester compound of the present invention is not particularly limited, but is preferably 270 to 700, more preferably 270 to 650, and further preferably 270 to 600.

  The obtained cyanate compound can be identified by a known method such as NMR. The purity of the cyanate ester compound can be analyzed by liquid chromatography or IR spectroscopy. Volatile components such as by-products such as dialkyl cyanoamide and residual solvents in the cyanate ester compound can be quantitatively analyzed by gas chromatography. The halogen compound remaining in the cyanate ester compound can be identified by a liquid chromatograph mass spectrometer, and can be quantitatively analyzed by ion chromatography after decomposition by a potentiometric titration using a silver nitrate solution or a combustion method. . The polymerization reactivity of the cyanate ester compound can be evaluated by the gel time by a hot plate method or a torque measurement method.

<Curable resin composition>
The curable resin composition of the present invention contains the above-described cyanate compound. This curable resin composition is a cyanate ester compound other than the above-described cyanate ester compound (hereinafter referred to as “another cyanate ester compound”), a maleimide compound, and phenol as long as the desired properties are not impaired. It may contain a resin, an epoxy resin, an oxetane resin, a benzoxazine compound, and / or a compound having a polymerizable unsaturated group.

The other cyanate compound is a compound having an aromatic moiety in which at least one cyanato group is substituted in the molecule, and other compounds obtained by cyanating a naphthol-dihydroxynaphthalene aralkyl resin. Not limited. For example, a compound represented by the general formula (7) is given.
(Wherein, Ar ₁ independently represents a phenylene group, a naphthylene group or a biphenylene group, and when there are a plurality of them, they may be the same or different. Ra is each independently a hydrogen atom, a carbon atom 1 And C 6 to C 12 aryl groups, C 1 to C 4 alkoxy groups, and groups in which C 1 to C 6 alkyl groups and C 6 to C 12 aryl groups are bonded. The aromatic ring in Ra may have a substituent, Ar ₁ and the substituent in Ra can be selected at any positions, p represents the number of cyanato groups bonded to Ar ₁ , and each independently represents 1 to And q is an integer of 3. q represents the number of Ra bonded to Ar ₁ and is 4-p when Ar ₁ is a phenylene group, 6-p when Ar ₁ is a naphthylene group, and 8-p when Ar ₁ is a biphenylene group. T represents the average number of repetitions, and is an integer of 0 to 50. And t may be a mixture of different compounds. X is each independently a single bond, a divalent organic group having 1 to 50 carbon atoms (a hydrogen atom may be substituted with a hetero atom). A divalent organic group having 1 to 10 nitrogen atoms (for example, -N-R-N- (where R represents an organic group)), a carbonyl group (-CO-), a carboxy group (-C (= O) O-), carbonyl dioxide group (-OC (= O) O-) , a sulfonyl group _(-SO 2 -), or represents any divalent sulfur atom or a divalent oxygen atom).

The alkyl group for Ra in the general formula (7) may have any of a linear or branched chain structure and a cyclic structure (for example, a cycloalkyl group or the like).
The hydrogen atom in the alkyl group in the general formula (7) and the aryl group in Ra may be substituted with a halogen atom such as a fluorine atom or a chlorine atom, an alkoxy group such as a methoxy group or a phenoxy group, a cyano group, or the like. Good.
Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a 1-ethylpropyl group, and a 2,2-dimethyl group. Examples include a propyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, and a trifluoromethyl group.
Specific examples of the aryl group include phenyl, xylyl, mesityl, naphthyl, phenoxyphenyl, ethylphenyl, o-, m- or p-fluorophenyl, dichlorophenyl, dicyanophenyl, trifluoro Examples include a phenyl group, a methoxyphenyl group, an o-, m- or p-tolyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, a tert-butoxy group, and the like.
Specific examples of the divalent organic group represented by X in the general formula (7) include an alkylene group such as a methylene group, an ethylene group, a trimethylene group, and a propylene group, a cyclopentylene group, a cyclohexylene group, and a trimethylcyclohexylene group. Examples thereof include divalent organic groups having an aromatic ring such as a cycloalkylene group, a biphenylylmethylene group, a dimethylmethylene-phenylene-dimethylmethylene group, a fluorenediyl group, and a phthalidodiyl group. A hydrogen atom in the divalent organic group may be substituted with a halogen atom such as a fluorine atom and a chlorine atom, an alkoxy group such as a methoxy group and a phenoxy group, a cyano group, and the like.
Examples of the divalent organic group having 1 to 10 nitrogen atoms in X in the general formula (7) include a group represented by —N—R—N—, an imino group, and a polyimide group.

In addition, specific structures of the organic group of X in the general formula (7) include a divalent group represented by the following general formula (8) or the following general formula (9).
(Wherein, Ar ₂ represents a phenylene group, a naphthylene group or a biphenylene group, and when u is 2 or more, they may be the same or different. Rb, Rc, Rf, and Rg are each independently A hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, a trifluoromethyl group, or an aryl group having at least one phenolic hydroxy group, wherein Rd and Re are each independently a hydrogen atom , An alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or a hydroxy group. U represents an integer of 0 to 5.)
(Wherein, Ar ₃ is selected from any one of a phenylene group, a naphthylene group, and a biphenylene group. Ri and Rj are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and an aryl group having 6 to 12 carbon atoms. A benzyl group, an alkoxy group having 1 to 4 carbon atoms, a hydroxy group, a trifluoromethyl group, or an aryl group in which at least one cyanato group is substituted, and v is an integer of 0 to 5, , V may be a mixture of different compounds.)

Furthermore, X in the general formula (7) includes a divalent group represented by the following formula.
(In the formula, m represents an integer of 4 to 7. R independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.)
Specific examples of Ar ₃ of Ar ₂ and of the general formula (8) (9), 1,4-phenylene group, a 1,3-phenylene group, 4,4'-biphenylene, 2,4'- Biphenylene group, 2,2′-biphenylene group, 2,3′-biphenylene group, 3,3′-biphenylene group, 3,4′-biphenylene group, 2,6-naphthylene group, 1,5-naphthylene group, 1 , 6-naphthylene group, 1,8-naphthylene group, 1,3-naphthylene group, 1,4-naphthylene group, 2,7-naphthylene group and the like.
The alkyl group and the aryl group in Rb to Rg in the general formula (8) and Ri and Rj in the general formula (9) are the same as those in the general formula (7).

Specific examples of the cyanato-substituted aromatic compound represented by the general formula (7) include cyanatobenzene, 1-cyanato-2-, 1-cyanato-3-, or 1-cyanato-4-methylbenzene, Cyanato-2-, 1-cyanato-3-, or 1-cyanato-4-methoxybenzene, 1-cyanato-2,3-, 1-cyanato-2,4-, 1-cyanato-2,5-, 1 -Cyanato-2,6-, 1-cyanato-3,4- or 1-cyanato-3,5-dimethylbenzene, cyanatoethylbenzene, cyanatobutylbenzene, cyanatooctylbenzene, cyanatononylbenzene, 2- ( 4-cyanatophenyl) -2-phenylpropane (cyanate of 4-α-cumylphenol), 1-cyanato-4-cyclohexylbenzene, 1-cyanato-4-vinylbenzene 1-cyanato-2- or 1-cyanato-3-chlorobenzene, 1-cyanato-2,6-dichlorobenzene, 1-cyanato-2-methyl-3-chlorobenzene, cyanatonitrobenzene, 1-cyanato-4-nitro- 2-ethylbenzene, 1-cyanato-2-methoxy-4-allylbenzene (cyanate of eugenol), methyl (4-cyanatophenyl) sulfide, 1-cyanato-3-trifluoromethylbenzene, 4-cyanatobiphenyl, -Cyanato-2- or 1-cyanato-4-acetylbenzene, 4-cyanatobenzaldehyde, 4-cyanatobenzoic acid methyl ester, 4-cyanatobenzoic acid phenyl ester, 1-cyanato-4-acetoaminobenzene, 4-si Anatobenzophenone, 1-cyanato-2,6-di-tert- Butylbenzene, 1,2-dicyanatobenzene, 1,3-dicyanatobenzene, 1,4-dicyanatobenzene, 1,4-dicyanato-2-tert-butylbenzene, 1,4-dicyanato-2,4- Dimethylbenzene, 1,4-dicyanato-2,3,4-trimethylbenzene, 1,3-dicyanato-2,4,6-trimethylbenzene, 1,3-dicyanato-5-methylbenzene, 1-cyanato or 2- Cianatonaphthalene, 1-cyanato-4-methoxynaphthalene, 2-cyanato-6-methylnaphthalene, 2-cyanato-7-methoxynaphthalene, 2,2 "-dicyanato-1,1" -binaphthyl, 1,3-, 1 , 4-, 1,5-, 1,6-, 1,7-, 2,3-, 2,6- or 2,7-dicyanatosinaphthalene, 2,2'- or 4,4'-dicia Tobiphenyl, 4,4'-dicyanatooctafluorobiphenyl, 2,4'- or 4,4'-dicyanatodiphenylmethane, bis (4-cyanato-3,5-dimethylphenyl) methane, 1,1-bis ( 4-cyanatophenyl) ethane, 1,1-bis (4-cyanatophenyl) propane, 2,2-bis (4-cyanatophenyl) propane, 2,2-bis (4-cyanato-3-methylphenyl) ) Propane, 2,2-bis (2-cyanato-5-biphenylyl) propane, 2,2-bis (4-cyanatophenyl) hexafluoropropane, 2,2-bis (4-cyanato-3,5- Dimethylphenyl) propane, 1,1-bis (4-cyanatophenyl) butane, 1,1-bis (4-cyanatophenyl) isobutane, 1,1-bis (4-cyanatophenyl) Pentane, 1,1-bis (4-cyanatophenyl) -3-methylbutane, 1,1-bis (4-cyanatophenyl) -2-methylbutane, 1,1-bis (4-cyanatophenyl) -2 2,2-dimethylpropane, 2,2-bis (4-cyanatophenyl) butane, 2,2-bis (4-cyanatophenyl) pentane, 2,2-bis (4-cyanatophenyl) hexane, 2, 2-bis (4-cyanatophenyl) -3-methylbutane, 2,2-bis (4-cyanatophenyl) -4-methylpentane, 2,2-bis (4-cyanatophenyl) -3,3- Dimethylbutane, 3,3-bis (4-cyanatophenyl) hexane, 3,3-bis (4-cyanatophenyl) heptane, 3,3-bis (4-cyanatophenyl) octane, 3,3-bis (4-Cyanatofe L) -2-methylpentane, 3,3-bis (4-cyanatophenyl) -2-methylhexane, 3,3-bis (4-cyanatophenyl) -2,2-dimethylpentane, 4,4- Bis (4-cyanatophenyl) -3-methylheptane, 3,3-bis (4-cyanatophenyl) -2-methylheptane, 3,3-bis (4-cyanatophenyl) -2,2-dimethyl Hexane, 3,3-bis (4-cyanatophenyl) -2,4-dimethylhexane, 3,3-bis (4-cyanatophenyl) -2,2,4-trimethylpentane, 2,2-bis ( 4-cyanatophenyl) -1,1,1,3,3,3-hexafluoropropane, bis (4-cyanatophenyl) phenylmethane, 1,1-bis (4-cyanatophenyl) -1-phenyl Ethane, bis (4-sia Tophenyl) biphenylmethane, 1,1-bis (4-cyanatophenyl) cyclopentane, 1,1-bis (4-cyanatophenyl) cyclohexane, 2,2-bis (4-cyanato-3-isopropylphenyl) propane , 1,1-bis (3-cyclohexyl-4-cyanatophenyl) cyclohexane, bis (4-cyanatophenyl) diphenylmethane, bis (4-cyanatophenyl) -2,2-dichloroethylene, 1,3-bis [ 2- (4-cyanatophenyl) -2-propyl] benzene, 1,4-bis [2- (4-cyanatophenyl) -2-propyl] benzene, 1,1-bis (4-cyanatophenyl) -3,3,5-trimethylcyclohexane, 4- [bis (4-cyanatophenyl) methyl] biphenyl, 4,4-dicyanatobenzophene Non, 1,3-bis (4-cyanatophenyl) -2-propen-1-one, bis (4-cyanatophenyl) ether, bis (4-cyanatophenyl) sulfide, bis (4-cyanatophenyl) ) Sulfone, 4-cyanatobenzoic acid-4-cyanatophenyl ester (4-cyanatophenyl-4-cyanatobenzoate), bis- (4-cyanatophenyl) carbonate, 1,3-bis (4-cyanato Phenyl) adamantane, 1,3-bis (4-cyanatophenyl) -5,7-dimethyladamantane, 1,3-bis (3-methyl-4-cyanatophenyl) -5,7-dimethyladamantane, 3, 3-bis (4-cyanatophenyl) isobenzofuran-1 (3H) -one (cyanate of phenolphthalein), 3,3-bis (4-cyanato-3 Methylphenyl) isobenzofuran-1 (3H) -one (cyanate of o-cresolphthalein), 9,9′-bis (4-cyanatophenyl) fluorene, 9,9-bis (4-cyanato-3-methyl) Phenyl) fluorene, 9,9-bis (2-cyanato-5-biphenylyl) fluorene, tris (4-cyanatophenyl) methane, 1,1,1-tris (4-cyanatophenyl) ethane, 1,1 , 3-Tris (4-cyanatophenyl) propane, α, α, α'-tris (4-cyanatophenyl) -1-ethyl-4-isopropylbenzene, 1,1,2,2-tetrakis (4- Cyanatophenyl) ethane, tetrakis (4-cyanatophenyl) methane, 2,4,6-tris (N-methyl-4-cyanatoanilino) -1,3,5-triazine, 2, 4-bis (N-methyl-4-cyanatoanilino) -6- (N-methylanilino) -1,3,5-triazine, bis (N-4-cyanato-2-methylphenyl) -4,4′-oxydi Phthalimide, bis (N-3-cyanato-4-methylphenyl) -4,4′-oxydiphthalimide, bis (N-4-cyanatophenyl) -4,4′-oxydiphthalimide, bis (N-4 -Cyanato-2-methylphenyl) -4,4 '-(hexafluoroisopropylidene) diphthalimide, tris (3,5-dimethyl-4-cyanatobenzyl) isocyanurate, 2-phenyl-3,3-bis ( 4-cyanatophenyl) phthalimidine, 2- (4-methylphenyl) -3,3-bis (4-cyanatophenyl) phthalimidine, 2-phenyl-3,3-bis (4-cy Anato-3-methylphenyl) phthalimidine, 1-methyl-3,3-bis (4-cyanatophenyl) indoline-2-one, 2-phenyl-3,3-bis (4-cyanatophenyl) indoline-2 -One, phenol novolak resin or cresol novolak resin (by reacting a phenol, an alkyl-substituted phenol or a halogen-substituted phenol with a formaldehyde compound such as formalin or paraformaldehyde in an acidic solution by a known method), trisphenol novolak Resin (having hydroxybenzaldehyde and phenol reacted in the presence of an acidic catalyst), fluorene novolak resin (having a fluorenone compound and 9,9-bis (hydroxyaryl) fluorenes reacted in the presence of an acidic catalyst) ), Including furan ring Phenol novolak resin (resin obtained by reacting furfural and phenol in the presence of a basic catalyst), phenol aralkyl resin, cresol aralkyl resin, naphthol aralkyl resin, binaphthol aralkyl resin, naphthol-dihydroxynaphthalene aralkyl resin and biphenyl aralkyl resin (known in the art) Table with (CH 2 _{oR) 2 -} the by _methods, Ar 2 - _(CH 2 _Y) which the bishalogenomethyl compounds represented by ₂ and a phenolic compound is reacted with an acid catalyst or no _catalyst, Ar 2 A bis (alkoxymethyl) compound or a bis (hydroxymethyl) compound represented by Ar ₂ — (CH ₂ OH) ₂ reacted with a phenol compound in the presence of an acidic catalyst, or an aromatic compound Aldehyde compounds, aralkylation Product, a product obtained by polycondensation with a phenol compound), a phenol-modified xylene formaldehyde resin (a product obtained by reacting a xylene formaldehyde resin with a phenol compound by a known method in the presence of an acidic catalyst), a modified naphthalene formaldehyde resin (known in the art) A naphthalene formaldehyde resin and a hydroxy-substituted aromatic compound reacted in the presence of an acidic catalyst), a phenol-modified dicyclopentadiene resin, a phenol resin having a polynaphthylene ether structure (a phenolic hydroxy A phenolic resin such as a polyvalent hydroxynaphthalene compound having two or more groups in one molecule which is dehydrated and condensed in the presence of a basic catalyst), and the like, and the like, and the like. , Especially restricted Not something. These other cyanate compounds can be used alone or in combination of two or more.

  As the maleimide compound, a generally known compound having one or more maleimide groups in one molecule can be used. Examples of the maleimide compound include o-phenylenebismaleimide, m-phenylenebismaleimide, p-phenylenebismaleimide, o-phenylenebiscitraconimide, m-phenylenebiscitraconimide, p-phenylenebiscitraconimide, 4,4 ′ -Diphenylmethanebismaleimide, bis (3,5-dimethyl-4-maleimidophenyl) methane, bis (3-ethyl-5-methyl-4-maleimidophenyl) methane, bis (3,5-diethyl-4-maleimidophenyl) Methane, 2,2′-bis [4- (4-maleimidophenoxy) phenyl] propane, 4-methyl-1,3-phenylenebismaleimide, 1,6′-bismaleimide- (2,2,4-trimethyl) Hexane, 4,4-diphenyl ether bismaleimide, 1,4-diphenylsulfonebismaleimide, 1,3-bis (3-maleimidophenoxy) benzene, 1,3-bis (4-maleimidophenoxy) benzene, 4,4′-diphenylmethanebiscitraconimide, 2,2′-bis [4- (4-citraconic imidophenoxy) phenyl] propane, bis (3,5-dimethyl-4-citraconic imidophenyl) methane, bis (3-ethyl-5-methyl-4-citraconic imidophenyl) methane, bis ( 3,5-diethyl-4-citraconimidophenyl) methane, polyphenylmethanemaleimide, and a prepolymer of these maleimide compounds, or a prepolymer of the above-mentioned maleimide compound and an amine compound, but are not particularly limited. is not. These maleimide compounds can be used alone or in combination of two or more.

  As the phenol resin, a phenol resin having two or more hydroxy groups in one molecule is preferable, and a generally known phenol resin can be used. Examples of the phenol resin include bisphenol A phenol resin, bisphenol E phenol resin, bisphenol F phenol resin, bisphenol S phenol resin, phenol novolak resin, bisphenol A novolak phenol resin, glycidyl ester phenol resin, and aralkyl novolak. Phenolic resin, biphenylaralkyl phenolic resin, cresol novolak phenolic resin, polyfunctional phenolic resin, naphthol resin, naphthol novolak resin, polyfunctional naphthol resin, anthracene phenolic resin, naphthalene skeleton modified novolak phenolic resin, phenol aralkyl phenol Resin, naphthol aralkyl phenol resin, dicyclopentadiene phenol resin, Phenyl type phenolic resin, alicyclic phenolic resin, polyol type phenolic resin, phosphorus-containing phenolic resin, polymerizable unsaturated hydrocarbon group-containing phenolic resin, and hydroxyl group-containing silicone resin, but are not particularly limited. . These phenol resins can be used alone or in combination of two or more.

  As the epoxy resin, a generally known epoxy resin can be used as long as the compound has two or more epoxy groups in one molecule. Examples of the epoxy resin include bisphenol A epoxy resin, bisphenol E epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol A novolak epoxy resin, biphenyl epoxy resin, phenol novolak epoxy resin, and cresol novolak. Epoxy resin, xylene novolak epoxy resin, naphthalene epoxy resin, anthracene epoxy resin, trifunctional phenol epoxy resin, tetrafunctional phenol epoxy resin, triglycidyl isocyanurate, glycidyl ester epoxy resin, alicyclic epoxy resin , Dicyclopentadiene novolak epoxy resin, biphenyl novolak epoxy resin, phenol aralkyl novolak epoxy resin, naph Aralkyl novolak type epoxy resin, aralkyl novolak type epoxy resin, biphenyl aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, dicyclopentadiene type epoxy resin, polyol type epoxy resin, alicyclic epoxy resin, or a halide thereof. No. These epoxy resins can be used alone or in combination of two or more.

  As the oxetane resin, generally known ones can be used. Examples of the oxetane resin include alkyl oxetanes such as oxetane, 2-methyloxetane, 2,2-dimethyloxetane, 3-methyloxetane, and 3,3-dimethyloxetane; 3-methyl-3-methoxymethyloxetane; In addition to '-di (trifluoromethyl) perfluoxetane, 2-chloromethyloxetane, and 3,3-bis (chloromethyl) oxetane, commercially available products such as OXT-101 (trade name, manufactured by Toagosei) and OXT- 121 (trade name, manufactured by Toagosei Co., Ltd.). These oxetane resins can be used alone or in combination of two or more.

  As the benzoxazine compound, a compound having two or more dihydrobenzoxazine rings in one molecule is preferable, and generally known compounds can be used. Examples of the benzoxazine compound include bisphenol A-type benzoxazine, BA-BXZ (trade name of Konishi Chemical), bisphenol F-type benzoxazine, BF-BXZ (trade name of Konishi Chemical), and bisphenol S-type benzoxazine. BS-BXZ (trade name, manufactured by Konishi Chemical) and phenolphthalein-type benzoxazine. These benzoxazine compounds can be used alone or in combination of two or more.

  As the compound having a polymerizable unsaturated group, generally known compounds can be used. Examples of the compound having a polymerizable unsaturated group include, for example, vinyl compounds such as ethylene, propylene, styrene, divinylbenzene, and divinylbiphenyl, methyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, and 2-hydroxypropyl ( Monovalent such as (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate Or epoxy (meth) acrylates such as polyhydric alcohol (meth) acrylates, bisphenol A type epoxy (meth) acrylate, and bisphenol F type epoxy (meth) acrylate , Benzocyclobutene resins. These compounds having a polymerizable unsaturated group can be used alone or in combination of two or more. The “(meth) acrylate” is a concept including acrylate and methacrylate corresponding thereto.

  In the curable resin composition of the present invention, in addition to the compounds and resins described above, further, a cyanate ester compound, a maleimide compound, a phenol resin, an epoxy resin, an oxetane resin, and a polymer having a polymerizable unsaturated group. Compounds that act as catalysts can be included. Examples of the polymerization catalyst include metal salts such as zinc octylate, zinc naphthenate, cobalt naphthenate, copper naphthenate, and iron acetylacetone; phenol compounds such as octylphenol and nonylphenol; and alcohols such as 1-butanol and 2-ethylhexanol. 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4,5- Imidazole derivatives such as dihydroxymethylimidazole and 2-phenyl-4-methyl-5-hydroxymethylimidazole; amine compounds such as dicyandiamide, benzyldimethylamine and 4-methyl-N, N-dimethylbenzylamine; Systems include phosphorus compounds phosphonium. Further, an epoxy-imidazole adduct compound, benzoyl peroxide, p-chlorobenzoyl peroxide, di-t-butyl peroxide, diisopropyl peroxycarbonate, peroxide such as di-2-ethylhexyl peroxycarbonate, or azobis An azo compound such as isobutyronitrile may be used as a polymerization catalyst. Commercially available polymerization catalysts may be used, and examples of commercially available products include Amicure PN-23 (trade name, manufactured by Ajinomoto Fine Techno Co.), Novacure HX-3721 (trade name, manufactured by Asahi Kasei Corporation), and Fujicure FX-1000. (Trade name, manufactured by Fuji Chemical Industry Co., Ltd.). These polymerization catalysts can be used alone or in combination of two or more.

  An inorganic filler can be used for the curable resin composition in the present invention. Examples of the inorganic filler include talc, calcined clay, unfired clay, mica, E glass, A glass, NE glass, C glass, L glass, D glass, S glass, M glass G20, short glass fiber (E glass And fine glass powders such as T glass, D glass, S glass, and Q glass), silicates such as hollow glass, spherical glass, silica, and fused silica, titanium oxide, alumina, gibbsite, boehmite, and zinc oxide. Oxides such as magnesium oxide, magnesium oxide, zirconium oxide and molybdenum oxide, carbonates such as calcium carbonate, magnesium carbonate and hydrotalcite, hydroxides such as aluminum hydroxide, magnesium hydroxide and calcium hydroxide, barium sulfate and calcium sulfate , Sulfate or sulfite such as calcium sulfite, zinc borate, barium metaborate, borate Aluminum, calcium borate, borate such as sodium borate, aluminum nitride, boron nitride, silicon nitride, nitride such as carbon nitride, carbide such as silicon carbide, strontium titanate, titanate such as barium titanate, Examples include zinc molybdate, silicone composite powder, silicone resin powder, and the like. These inorganic fillers can be used alone or in combination of two or more. These can be used by increasing the filling amount by mixing those having different shapes (spherical or crushed) or different sizes.

  The inorganic filler may have been previously treated with a treating agent for surface treatment. As the treating agent, at least one compound selected from the group consisting of functional group-containing silanes, cyclic oligosiloxanes, organohalosilanes, and alkylsilazanes can be suitably used. Among them, the surface treatment of spherical silica using organohalosilanes and alkylsilazanes is suitable for hydrophobizing the silica surface, and the dispersibility of the spherical silica in the curable resin composition. It is preferable because of its superiority.

  Further, the curable resin composition of the present invention, if necessary, a thermoplastic resin, a curing catalyst, a curing accelerator, a coloring pigment, a defoaming agent, a surface conditioner, a flame retardant, an ultraviolet absorber, an antioxidant, Contains known additives such as photopolymerization initiators, fluorescent brighteners, photosensitizers, dyes, pigments, thickeners, lubricants, flow regulators, dispersants, leveling agents, brighteners, and polymerization inhibitors. May be. Further, if necessary, a solvent may be contained. These optional additives can be used alone or in combination of two or more.

  As the solvent, generally known solvents can be used. Examples of the solvent include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, cellosolve solvents such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate, methyl lactate, methyl acetate, methyl acetate, ethyl acetate, butyl acetate and acetic acid. Ester solvents such as isoamyl, ethyl lactate, methyl methoxypropionate, and methyl hydroxyisobutyrate; alcohol solvents such as methanol, ethanol, isopropanol and 1-ethoxy-2-propanol; and aromatic carbonization such as toluene, xylene and anisole. Hydrogen and the like. These solvents can be used alone or in combination of two or more.

  The curable resin composition in the present invention contains the cyanate ester compound described above, and if necessary, another cyanate ester compound, a maleimide compound, a phenol resin, an epoxy resin, an oxetane resin, a benzoxazine compound, and / or Compounds having a polymerizable unsaturated group and various additives, together with a solvent, using a known mixer, for example, a high-speed mixer, a Nauter mixer, a ribbon-type blender, a kneader, an intensive mixer, a universal mixer, a dissolver, a static mixer, etc. Can be obtained by mixing. The method of adding the cyanate ester compound, various additives, and the solvent at the time of mixing is not particularly limited.

  The curable resin composition according to the present invention can be cured by curing with heat, light, or the like. The cured product can be obtained, for example, by melting or dissolving the curable resin composition in a solvent, then pouring the same into a mold, and curing under ordinary conditions. In the case of thermal curing, the curing temperature is preferably in the range of 120 ° C to 300 ° C from the viewpoint of further promoting curing and further suppressing deterioration of the cured product.

<Use of curable resin composition>
The encapsulating material of the present invention contains the above curable resin composition, and can be manufactured using the curable resin composition. As a method for producing the sealing material, a generally known method can be appropriately applied, and is not particularly limited. For example, the curable resin composition, and various additives or solvents that are known to be used in the production of the sealing material, for mixing by using a known mixer for sealing Material can be manufactured. In addition, the method of adding the curable resin composition, various additives, and the solvent at the time of mixing can be appropriately selected from generally known ones, and is not particularly limited.

  The prepreg for a structural material of the present invention includes a base material and the curable resin composition impregnated or applied to the base material. The prepreg for a structural material can be manufactured by impregnating or applying the above-mentioned curable resin composition to an inorganic and / or organic fiber base material, and further drying as necessary.

  The base material is not particularly limited, but includes, for example, inorganic fiber materials such as glass fiber base materials such as glass woven fabric and glass non-woven fabric, polyamide-based fibers such as polyamide resin fibers, aromatic polyamide resin fibers and wholly aromatic polyamide resin fibers. Synthetic fiber base composed of woven or non-woven fabric mainly composed of polyester resin fiber such as resin fiber, polyester resin fiber, aromatic polyester resin fiber and wholly aromatic polyester resin fiber, polyimide resin fiber, fluororesin fiber, etc. And organic fiber base materials such as paper base materials mainly composed of materials, kraft paper, cotton linter paper, and mixed paper of linter and kraft pulp. According to the performance required for the prepreg, for example, the strength, the water absorption and the coefficient of thermal expansion, these known ones can be appropriately selected and used. The glass constituting the glass fiber substrate is not particularly limited, and examples thereof include E glass, C glass, A glass, S glass, D glass, NE glass, T glass, and H glass.

  As a method for producing a prepreg for a structural material, a generally known method can be appropriately applied, and is not particularly limited. For example, by preparing a resin varnish using the curable resin composition described above, a method of immersing the substrate in the resin varnish, a method of applying the resin varnish to the substrate with various coaters, a method of spraying with a spray, and the like. , Prepreg can be manufactured. Among these, the method of immersing the base material in the resin varnish is preferable. Thereby, the impregnation property of the resin composition to the base material can be improved. When the substrate is immersed in the resin varnish, ordinary impregnation coating equipment can be used. For example, a method in which a resin composition varnish is impregnated into an inorganic and / or organic fiber base material, dried, and B-staged to produce a prepreg can be applied.

  The fiber-reinforced composite material of the present invention contains the above curable resin composition, and can be produced using the curable resin composition and the reinforcing fibers. As the reinforcing fibers contained in the fiber-reinforced composite material, for example, fibers such as carbon fiber, glass fiber, aramid fiber, boron fiber, PBO fiber, high-strength polyethylene fiber, alumina fiber, and silicon carbide fiber can be used. The form and arrangement of the reinforcing fibers are not particularly limited, and can be appropriately selected from woven fabrics, nonwoven fabrics, mats, knits, braids, unidirectional strands, rovings, chopped and the like. In addition, as a form of the reinforcing fibers, a preform (a laminated fabric base fabric made of reinforcing fibers, a stitch-integrated stitching fabric, or a fibrous structure such as a three-dimensional woven fabric or a braided fabric) is applied. Can also. Specific examples of the method for producing these fiber-reinforced composite materials include a liquid composite molding method, a resin film infusion method, a filament winding method, a hand lay-up method, and a pultrusion method. Among these, the resin transfer molding method, which is one of the liquid composite molding methods, requires that materials other than preforms, such as metal plates, foam cores, and honeycomb cores, be set in a molding die in advance. Can be applied to various uses. Therefore, the resin transfer molding method is preferably used when mass-producing a relatively complex composite material in a short time.

  The adhesive of the present invention contains the above curable resin composition, and can be produced using the curable resin composition. The method for producing the adhesive is not particularly limited, and generally known methods can be appropriately applied. For example, an adhesive is produced by mixing the curable resin composition and various additives or solvents that are known to be used in producing the adhesive with a known mixer. be able to. In addition, the method of adding the curable resin composition, various additives, and the solvent at the time of mixing can be appropriately selected from generally known ones, and is not particularly limited.

  The curable resin composition according to the present invention has excellent low thermal expansion properties, flame retardancy, and heat resistance, and is therefore extremely useful as a high-functional polymer material, and has excellent thermal, electrical, and mechanical properties. In addition to electrical insulation materials, sealing materials, adhesives, laminate materials, resists, build-up laminate materials, civil engineering and construction, electricity and electronics, automobiles, railways, ships, aircraft, sporting goods, arts and crafts, etc. Used in the field of fixing materials, structural members, reinforcing agents, molding materials, and the like. Among them, it is suitable for electrical insulating materials, semiconductor sealing materials, adhesives for electronic components, aircraft structural members, satellite structural members, and railway vehicle structural members requiring low thermal expansion properties, flame resistance and high mechanical strength. is there.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not particularly limited by the following examples.

(Measurement of OH group (g / eq.) Equivalent of hydroxyl group-containing aromatic compound)
The OH group equivalent (g / eq.) Was determined by the pyridine-acetyl chloride method according to JIS-K0070.

(Measurement of weight average molecular weight Mw of cyanate compound)
10 μL of a solution in which 1 g of the cyanate ester compound was dissolved in 100 g of tetrahydrofuran (solvent) was injected into high-performance liquid chromatography (High-Performance Liquid Chromatograph LacromElite manufactured by Hitachi High-Technologies Corporation) to perform analysis. The column is two TSKgel GMH _HR- M (30 cm length x 7.8 mm inner diameter) manufactured by Tosoh Corporation, the mobile phase is tetrahydrofuran, and the flow rate is 1 mL / min. , The detector is RI. The weight average molecular weight Mw was determined by GPC using polystyrene as a standard substance.

(Example 1) Synthesis of cyanate ester compound 1 of asymmetric phenol novolak resin 1 (hereinafter abbreviated as ECN-1-M) ECN-1-M represented by the following formula (1) was prepared as described below. And synthesized.
(In the formula, n is 1.8 as an average value.)

<Synthesis of asymmetric phenol novolak resin 1 (hereinafter abbreviated as “EOH-1-M”)>
First, EOH-1-M represented by the following formula (2) was synthesized.
(In the formula, n is 1.8 as an average value.)

  Specifically, 85 g of phenol, 10 g of acetaldehyde, and 0.5 mL of 96% sulfuric acid were placed in a 300 mL four-necked flask equipped with a Liebig condenser, a thermometer, and a stirring blade under a nitrogen stream at a cooling temperature (0 to 10%). ℃) and stirred. After confirming dissolution, the reaction was carried out at 20 ° C. for 48 hours. After adding 100 g of ethyl acetate and repeating washing with water, magnesium sulfate was added and dried. The solid content was removed by filtration, and unreacted phenol and ethyl acetate were distilled off under reduced pressure under heating to obtain 23 g of EOH-1-M. The OH group equivalent of the obtained EOH-1-M was 128 g / eq. Met.

<Synthesis of ECN-1-M>
Next, 15 g of EOH-1-M (OH group equivalent 128 g / eq.) (0.12 mol in terms of OH group) and 17.8 g (0.18 mol) of triethylamine (1 mol per mol of hydroxy group) obtained by the above method were obtained. (0.5 mol) was dissolved in 75 mL of dichloromethane.
14.4 g (0.23 mol) of cyanogen chloride (1.5 mol per mol of hydroxy group), 63.0 g of dichloromethane, 26.7 g (0.26 mol) of 36% hydrochloric acid (2 mol per mol of hydroxy group). 25 mol) and 133.5 g of water were dropped into the solution 1 over 30 minutes while maintaining the liquid temperature at −2 to −0.5 ° C. with stirring. After the addition of the solution 1 was completed, the mixture was stirred at the same temperature for 30 minutes, and then a solution in which 19.0 g (0.19 mol) of triethylamine (1.6 mol per mol of hydroxy group) was dissolved in 28.5 g of dichloromethane ( Solution 2) was poured in over 30 minutes. After the addition of the solution 2 was completed, the mixture was stirred at the same temperature for 30 minutes to complete the reaction.
Thereafter, the reaction solution was allowed to stand, and an organic phase and an aqueous phase were separated. The obtained organic phase was washed with 100 mL of 0.1N hydrochloric acid and then with 100 g of water seven times. The electric conductivity of the wastewater after the seventh washing was 20 μS / cm, and it was confirmed that the ionic compounds that could be removed by the washing with water were sufficiently removed.
The organic phase after washing with water was concentrated under reduced pressure, and finally concentrated at 80 ° C. for 1 hour to obtain 21.2 g of a target cyanate ester compound ECN-1-M (black purple viscous substance). The weight average molecular weight Mw of the obtained cyanate ester compound ECN-1-M was 385. The GPC chart is shown in FIG. Further, the IR spectrum of ECN-1-M showed absorptions at 2235 cm ^-1 and 2263 cm ^-1 (cyanate group), and no absorption of a hydroxy group. FIG. 2 shows the IR chart.

(Example 2)
<Preparation of curable resin composition and preparation of cured product>
100 parts by mass of the cyanate ester compound ECN-1-M obtained in Example 1 was put into an eggplant-shaped flask, heated and melted at 150 ° C., deaerated by a vacuum pump, and then zinc octylate (Nippon Chemical Industry Co., Ltd.) Curable resin composition was prepared by adding 0.05 parts by mass of the product (trade name, zinc nikka octate, metal content 18%) and shaking for 1 minute to mix.
The obtained curable resin composition is poured into a mold described in JIS-K7238-2-2009, placed in an oven, cured at 180 ° C. for 3 hours, and then heated at 250 ° C. for 5 hours, and cured. A cured product having a side of 100 mm and a thickness of 2 mm was obtained.

(Example 3) Synthesis of cyanate ester compound 2 of asymmetric phenol novolak resin 2 (hereinafter abbreviated as ECN-2-M) ECN-2-M represented by the following formula (1) was synthesized as described below. And synthesized.
(In the formula, n is 1.2 as an average value.)

<Synthesis of asymmetric phenol novolak resin 2 (hereinafter abbreviated as “EOH-2-M”)>
First, EOH-2-M represented by the following formula (2) was synthesized.
(In the formula, n is 1.2 as an average value.)

  Specifically, 85 g of phenol, 10 g of acetaldehyde, and 0.5 mL of phosphotungstic acid hydride were placed in a 300 mL four-necked flask equipped with a Liebig condenser, a thermometer, and a stirring blade under a nitrogen stream at a cooling temperature (0 to 0). (10 ° C.) and stirred. After confirming dissolution, the reaction was carried out at 20 ° C. for 48 hours. After adding 100 g of ethyl acetate and repeating washing with water, magnesium sulfate was added and dried. The solid content was removed by filtration, and unreacted phenol and ethyl acetate were distilled off under reduced pressure under heating to obtain 22 g of EOH-2-M. The OH group equivalent of the obtained EOH-2-M was 128 g / eq. Met.

<Synthesis of ECN-2-M>
Next, 15 g of EOH-2-M (OH group equivalent 128 g / eq.) (0.12 mol in terms of OH group) and 17.8 g (0.18 mol) of triethylamine (1 mol per 1 mol of hydroxy group) obtained by the above method were used. (0.5 mol) was dissolved in 75 mL of dichloromethane.
14.4 g (0.23 mol) of cyanogen chloride (1.5 mol per mol of hydroxy group), 63.0 g of dichloromethane, 26.7 g (0.26 mol) of 36% hydrochloric acid (2 mol per mol of hydroxy group). 25 mol) and 133.5 g of water were dropped into the solution 3 over 30 minutes while maintaining the liquid temperature at −2 to −0.5 ° C. with stirring. After the addition of the solution 3 was completed, the mixture was stirred at the same temperature for 30 minutes, and then a solution in which 19.0 g (0.19 mol) of triethylamine (1.6 mol per 1 mol of hydroxy group) was dissolved in 28.5 g of dichloromethane ( Solution 4) was poured in over 30 minutes. After the addition of the solution 4 was completed, the mixture was stirred at the same temperature for 30 minutes to complete the reaction.
Thereafter, the reaction solution was allowed to stand, and an organic phase and an aqueous phase were separated. The obtained organic phase was washed with 100 mL of 0.1N hydrochloric acid and then with 100 g of water seven times. The electric conductivity of the wastewater after the seventh washing was 20 μS / cm, and it was confirmed that the ionic compounds that could be removed by the washing with water were sufficiently removed.
The organic phase after washing with water was concentrated under reduced pressure, and finally concentrated at 80 ° C. for 1 hour to obtain 20.5 g of the desired cyanate ester compound ECN-2-M (black purple viscous substance). The weight average molecular weight Mw of the obtained cyanate ester compound ECN-2-M was 288. FIG. 3 shows the GPC chart.

(Example 4)
In Example 2, a cured product was obtained in the same manner as in Example 2 except that 100 parts by mass of ECN-1-M obtained in Example 3 was used instead of using 100 parts by mass of ECN-1-M. Obtained.

(Example 5) Synthesis of cyanate ester compound 3 of asymmetric phenol novolak resin 3 (hereinafter abbreviated as ECN-3-M) ECN-3-M represented by the following formula (1) was synthesized as described below. And synthesized.
(In the formula, n is 2.0 as an average value.)

<Synthesis of asymmetric phenol novolak resin 3 (hereinafter abbreviated as “EOH-3-M”)>
First, EOH-3-M represented by the following formula (2) was synthesized.
(In the formula, n is 2.0 as an average value.)

  Specifically, 85 g of phenol, 10 g of acetaldehyde, and 0.5 mL of 36% hydrochloric acid were placed in a 300 mL four-necked flask equipped with a Liebig condenser, a thermometer, and a stirring blade under a nitrogen stream at a cooling temperature (0 to 10%). ℃) and stirred. After confirming dissolution, the reaction was carried out at 95 ° C. for 4 hours and then at 160 ° C. for 7 hours. Then, 10 g of acetaldehyde was added dropwise and reacted at 160 ° C. for 3 hours. After adding 100 g of ethyl acetate and repeating washing with water, magnesium sulfate was added and dried. The solid content was removed by filtration, and unreacted phenol and ethyl acetate were distilled off under reduced pressure under heating to obtain 30 g of EOH-3-M. The OH group equivalent of the obtained EOH-3-M was 128 g / eq. Met.

<Synthesis of ECN-3-M>
Next, 15 g of EOH-3-M (OH group equivalent 128 g / eq.) (0.12 mol in terms of OH group) and 17.8 g (0.18 mol) of triethylamine (1 mol per 1 mol of hydroxy group) obtained by the above method. (0.5 mol) was dissolved in 75 mL of dichloromethane, and this was designated as solution 5.
14.4 g (0.23 mol) of cyanogen chloride (1.5 mol per mol of hydroxy group), 63.0 g of dichloromethane, 26.7 g (0.26 mol) of 36% hydrochloric acid (2 mol per mol of hydroxy group). 25 mol) and 133.5 g of water were poured over 30 minutes while stirring at a liquid temperature of −2 to −0.5 ° C. After the addition of the solution 5 was completed, the mixture was stirred at the same temperature for 30 minutes, and then a solution in which 19.0 g (0.19 mol) of triethylamine (1.6 mol per mol of hydroxy group) was dissolved in 28.5 g of dichloromethane ( Solution 6) was poured in over 30 minutes. After the addition of the solution 6, the mixture was stirred at the same temperature for 30 minutes to complete the reaction.
Thereafter, the reaction solution was allowed to stand, and an organic phase and an aqueous phase were separated. The obtained organic phase was washed with 100 mL of 0.1N hydrochloric acid and then with 100 g of water seven times. The electric conductivity of the wastewater after the seventh washing was 20 μS / cm, and it was confirmed that the ionic compounds that could be removed by the washing with water were sufficiently removed.
The organic phase after washing with water was concentrated under reduced pressure, and finally concentrated at 80 ° C. for 1 hour to obtain 20.5 g of a desired cyanate ester compound ECN-3-M (black purple viscous substance). The weight average molecular weight Mw of the obtained cyanate ester compound ECN-3-M was 378. The GPC chart is shown in FIG.

(Example 6)
In Example 2, a cured product was obtained in the same manner as in Example 2, except that 100 parts by mass of ECN-1-M obtained in Example 5 was used instead of using 100 parts by mass of ECN-1-M. Obtained.

(Example 7) Synthesis of cyanate ester compound 4 (hereinafter abbreviated as ECN-4-M) of asymmetric phenol novolak resin 4 ECN-4-M represented by the following formula (1) was synthesized as described below. And synthesized.
(In the formula, n is 2.9 as an average value.)

<Synthesis of asymmetric phenol novolak resin 4 (hereinafter abbreviated as “EOH-4-M”)>
First, EOH-4-M represented by the following formula (2) was synthesized.
(In the formula, n is 2.9 as an average value.)

  Specifically, 85 g of phenol, 10 g of acetaldehyde, 0.5 mL of 98% sulfuric acid, 0.5 mL of mercaptopropionate aldehyde were placed in a 300 mL four-necked flask equipped with a Liebig condenser, a thermometer and a stirring blade under a nitrogen stream. 40 mL was charged at a cooling temperature (0 to 10 ° C.) and stirred. After confirming dissolution, the reaction was carried out at 10 ° C. for 24 hours. The reaction was performed at 160 ° C. for 3 hours. After adding 100 g of ethyl acetate and repeating washing with water, magnesium sulfate was added and dried. The solid content was removed by filtration, and unreacted phenol and ethyl acetate were distilled off under reduced pressure under heating to obtain 30 g of EOH-4-M. The OH group equivalent of the obtained EOH-4-M was 128 g / eq. Met.

<Synthesis of ECN-4-M>
Next, 15 g of EOH-4-M (OH group equivalent 128 g / eq.) (0.12 mol in terms of OH group) and 17.8 g (0.18 mol) of triethylamine (1 mol per mol of hydroxy group) obtained by the above method were used. (5.5 mol) was dissolved in 75 mL of dichloromethane, and this was designated as solution 7.
14.4 g (0.23 mol) of cyanogen chloride (1.5 mol per mol of hydroxy group), 63.0 g of dichloromethane, 26.7 g (0.26 mol) of 36% hydrochloric acid (2 mol per mol of hydroxy group). 25 mol) and 133.5 g of water were poured in the solution 7 over 30 minutes while maintaining the liquid temperature at −2 to −0.5 ° C. with stirring. After the addition of the solution 7 was completed, the mixture was stirred at the same temperature for 30 minutes, and then a solution in which 19.0 g (0.19 mol) of triethylamine (1.6 mol per mol of hydroxy group) was dissolved in 28.5 g of dichloromethane ( Solution 8) was poured in over 30 minutes. After the addition of the solution 8 was completed, the mixture was stirred at the same temperature for 30 minutes to complete the reaction.
Thereafter, the reaction solution was allowed to stand, and an organic phase and an aqueous phase were separated. The obtained organic phase was washed with 100 mL of 0.1N hydrochloric acid and then with 100 g of water seven times. The electric conductivity of the wastewater after the seventh washing was 20 μS / cm, and it was confirmed that the ionic compounds that could be removed by the washing with water were sufficiently removed.
The organic phase after washing with water was concentrated under reduced pressure, and finally concentrated at 80 ° C. for 1 hour to obtain 20.5 g of a desired cyanate ester compound ECN-4-M (black purple viscous substance). The weight average molecular weight Mw of the obtained cyanate ester compound ECN-4-M was 536. The GPC chart is shown in FIG.

(Example 8)
In Example 2, a cured product was obtained in the same manner as in Example 2 except that 100 parts by mass of ECN-1-M obtained in Example 7 was used instead of using 100 parts by mass of ECN-1-M. Obtained.

(Comparative Example 1) Synthesis of cyanate ester compound 1 of phenol novolak resin 1 (hereinafter abbreviated as PN-1-CN) PN-1-CN represented by the following formula (3) was prepared as described below. Synthesized.
(In the formula, n is 1.3 as an average value.)

Phenol novolak resin 1 (manufactured by Gunei Chemical Co., Ltd .: trade name: LVR-821DL: OH group equivalent: 105 g / eq.) 20 g (0.19 mol in terms of OH group) and 28.9 g (0.29 mol) of triethylamine (1 mol of hydroxyl group) Was dissolved in 140 mL of dichloromethane, and this was used as solution 9.
19.9 g (0.32 mol) of cyanogen chloride (1.7 mol per mol of hydroxy group), 46.4 g of dichloromethane, 43.4 g (0.43 mol) of 36% hydrochloric acid (2 mol per mol of hydroxy group). 25 mol) and 217 g of water were poured over 30 minutes while stirring at a liquid temperature of −2 to −0.5 ° C. After the addition of the solution 9 was completed, the mixture was stirred at the same temperature for 30 minutes, and then a solution in which 19.0 g (0.19 mol) of triethylamine (1.6 mol per mol of hydroxy group) was dissolved in 28.5 g of dichloromethane ( Solution 10) was poured in over 30 minutes. After the addition of the solution 10 was completed, the mixture was stirred at the same temperature for 30 minutes to complete the reaction.
Thereafter, the reaction solution was allowed to stand, and an organic phase and an aqueous phase were separated. The obtained organic phase was washed with 100 mL of 0.1N hydrochloric acid and then with 100 g of water seven times. The electric conductivity of the wastewater after the seventh washing was 20 μS / cm, and it was confirmed that the ionic compounds that could be removed by the washing with water were sufficiently removed.
The organic phase after washing with water was concentrated under reduced pressure, and finally concentrated at 80 ° C. for 1 hour to obtain 25 g of the objective cyanate ester compound PN-1-CN (black purple viscous substance). The weight average molecular weight Mw of the obtained cyanate compound PN-1-CN was 300. The GPC chart is shown in FIG. In addition, the IR spectrum of PN-1-CN showed absorptions at 2234 cm ^-1 and 2260 cm ^-1 (cyanate ester group) and no absorption of a hydroxy group. FIG. 7 shows the IR chart.

(Comparative Example 2)
In Example 2, a cured product was prepared in the same manner as in Example 2 except that 100 parts by mass of PN-1-CN obtained in Comparative Example 1 was used instead of using 100 parts by mass of ECN-1-M. Obtained.

Comparative Example 3 Synthesis of Cyanate Ester Compound 2 of phenol novolak resin 2 (hereinafter abbreviated as PN-2-CN) PN-2-CN represented by the following formula (3) was prepared as described below. Synthesized.
(In the formula, n is 2.7 as an average value.)

Phenol novolak resin 2 (manufactured by Asahi Organic Materials Co., Ltd .: trade name PAPS-PN02: OH group equivalent 105 g / eq.) 25 g (0.24 mol in terms of OH group) and 36.1 g (0.36 mol) of triethylamine (1 mol of hydroxyl group) Was dissolved in 125 mL of dichloromethane, and this was used as solution 11.
21.9 g (0.36 mol) of cyanogen chloride (1.5 mol per mol of hydroxy group), 51.2 g of dichloromethane, 54.3 g (0.54 mol) of 36% hydrochloric acid (2 mol per mol of hydroxy group). 25 mol) and 271 g of water were dropped into the solution 11 over 30 minutes while maintaining the liquid temperature at −2 to −0.5 ° C. with stirring. After the addition of the solution 11 was completed, the mixture was stirred at the same temperature for 30 minutes, and then a solution in which 35.0 g (0.34 mol) of triethylamine (1.45 mol per 1 mol of hydroxy group) was dissolved in 35.0 g of dichloromethane ( Solution 12) was poured in over 30 minutes. After the addition of the solution 12 was completed, the mixture was stirred at the same temperature for 30 minutes to complete the reaction.
Thereafter, the reaction solution was allowed to stand, and an organic phase and an aqueous phase were separated. The obtained organic phase was washed with 100 mL of 0.1N hydrochloric acid and then with 100 g of water seven times. The electric conductivity of the wastewater after the seventh washing was 20 μS / cm, and it was confirmed that the ionic compounds that could be removed by the washing with water were sufficiently removed.
The organic phase after washing with water was concentrated under reduced pressure, and finally concentrated at 80 ° C. for 1 hour to obtain 30 g of the desired cyanate ester compound PN-2-CN (black purple viscous substance). The weight average molecular weight Mw of the obtained cyanate compound PN-2-CN was 467. The GPC chart is shown in FIG.

(Comparative Example 4)
In Example 2, a cured product was obtained in the same manner as in Example 2 except that 100 parts by mass of the PN-2-CN obtained in Comparative Example 2 was used instead of using 100 parts by mass of ECN-1-M. Obtained.

The properties of each cured product obtained as described above were evaluated by the following methods.
Glass transition temperature (Tg): Based on JIS-K-7197-2012 (JIS C6481), using a thermomechanical analyzer (trade name “TMA / SS7100” manufactured by SII Nano Technology Co., Ltd.) A thermomechanical analysis was performed in an expansion / compression mode using a test piece of 5 mm × 5 mm × 2 mm, a starting temperature of 30 ° C., an ending temperature of 330 ° C., a heating rate of 10 ° C./min, and a load of 0.05 N (49 mN). The inflection point of the obtained coefficient of thermal expansion was defined as the glass transition temperature. Glass transition temperature is an indicator of heat resistance.
Long-term heat resistance: The cured product prepared by the above method was stored in a hot-air oven at 250 ° C. for 360 hours in an air atmosphere, and the glass transition temperature after storage was measured. Those having a decrease in the glass transition temperature of 20% or less were regarded as acceptable, and those exceeding 20% were rejected.
Table 1 shows the evaluation results.

  As is clear from Table 1, it was confirmed that the cyanate ester compound of the asymmetric phenol novolak resin of the present invention had low viscosity and excellent handleability. Further, the cured product of the curable resin composition using the cyanate ester compound of the present invention has excellent heat resistance and long-term heat resistance as compared with those using the conventional cyanate ester compound. confirmed.

Claims (8)

A cyanate compound obtained by cyanating an asymmetric phenol novolak resin,
A cured product obtained by curing a curable resin composition having a structure represented by the following general formula (1) and containing a cyanate ester compound.
(In the formula, n represents 1.04 to 4 as an average value.) The cured product according to claim 1, wherein the asymmetric phenol novolak resin is obtained by reacting acetaldehyde and phenol in the presence of an acidic catalyst. The cured product according to claim 1, wherein the cyanate ester compound has a weight average molecular weight Mw of 270 to 700. 4 . The curable resin composition is selected from the group consisting of a cyanate compound other than the cyanate compound, a maleimide compound, a phenol resin, an epoxy resin, an oxetane resin, a benzoxazine compound, and a compound having a polymerizable unsaturated group. The cured product according to any one of claims 1 to 3 , further comprising at least one or more of the following . A cyanate compound obtained by cyanating an asymmetric phenol novolak resin,
A prepreg for a structural material, which is obtained by impregnating or applying a curable resin composition containing a cyanate ester compound having a structure represented by the following general formula (1) onto a substrate, followed by drying.
(In the formula, n represents 1.04 to 4 as an average value.) A cyanate compound obtained by cyanating an asymmetric phenol novolak resin,
A sealing material comprising a curable resin composition containing a cyanate ester compound having a structure represented by the following general formula (1) .
(In the formula, n represents 1.04 to 4 as an average value.) A cyanate compound obtained by cyanating an asymmetric phenol novolak resin,
A fiber-reinforced composite material comprising a curable resin composition containing a cyanate ester compound, having a structure represented by the following general formula (1) .
(In the formula, n represents 1.04 to 4 as an average value.) A cyanate compound obtained by cyanating an asymmetric phenol novolak resin,
An adhesive comprising a curable resin composition containing a cyanate ester compound having a structure represented by the following general formula (1) .
(In the formula, n represents 1.04 to 4 as an average value.)