JP6288559B2 - Cyanate ester compound, curable resin composition containing the compound, and cured product thereof - Google Patents

Description

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

  Cyanate ester compounds produce triazine rings upon curing, and due to their high heat resistance and excellent electrical properties, various functional polymer materials such as structural composite materials, adhesives, electrical insulating materials, and electrical and electronic parts are used. Widely used as a raw material. However, in recent years, with the sophistication of required performance in these application fields, various physical properties required as a functional polymer material have become increasingly severe. Examples of such physical properties include flame retardancy, heat resistance, low thermal expansion coefficient, low water absorption, low dielectric constant, low dielectric loss tangent, weather resistance, chemical resistance, and high fracture toughness. However, so far, these required physical properties have not always been satisfied.

  For example, in the field of semiconductor packaging materials, there is a problem that warpage occurs with the thinning of the substrate. As a means for solving this, high heat resistance is provided for the functional polymer material itself used for the substrate material. There is a need to improve (dimension stabilization). In addition, lead-free solder is being used for soldering printed wiring boards from the viewpoint of the human body and the environment, and from the point of being able to withstand the high temperature reflow process, the functional polymer material itself is used. Therefore, it is required to improve high heat resistance.

  In addition, halogen-based gases that may cause environmental pollution during combustion may be generated, and required physical properties (heat resistance, moisture resistance, low water absorption) other than halogen atoms and flame retardancy that lower the insulation of the final product It is also demanded to improve the flame retardancy of the functional polymer material itself without including phosphorus atoms, which are often reduced.

  Examples of obtaining a cured product of a cyanate ester compound having flame retardancy and heat resistance include an isocyanuric acid skeleton-containing cyanate ester compound (see Patent Document 1), a triazine skeleton-containing cyanate ester compound (Patent Document 2) For example, a bifunctional cyanatophenyl type cyanate ester compound (see Patent Document 3) in which methylene group hydrogen bonding between cyanatophenyl groups is substituted with a biphenyl group, or a bisphenol A type cyanate ester compound is used. Combining an imide skeleton-containing cyanate ester compound has been proposed (see Patent Document 4). However, in either case, both performances are insufficient.

Japanese Patent No. 4654770 JP 2012-036114 A Japanese Patent No. 5104312 JP 2010-180147 A

So far, a practical cured product of a cyanate ester compound having flame retardancy and heat resistance at a high level has not been obtained.
Accordingly, an object of the present invention is to provide a novel cyanate ester compound, a curable resin composition containing the compound, and the like from which a cured product having excellent flame retardancy and heat resistance can be obtained.

  The present inventors have found that a curable resin composition using a cyanate ester compound obtained by cyanating a fluorene novolak resin can realize a cured product having excellent flame retardancy and heat resistance, and the like. The present invention has been reached. That is, the present invention is as follows.

  1. A cyanate ester compound obtained by cyanating a fluorene novolac resin.

2. 1. It has a structure represented by the following general formula (1). The cyanate ester compound described in 1.
(In the formula, Ar represents an aromatic ring, R ₁ represents a monovalent substituent, each independently represents a hydrogen atom, an alkyl group or an aryl group; R ₂ each independently represents a hydrogen atom, 4 represents an alkyl group, R ₃ is selected from a hydrogen atom, any one of the following general formula (2) or the following general formula (3), n represents an integer of 1 or more, and m is 1 to 3. X represents an integer that can be substituted for R ₁ of Ar, and y independently represents an integer of 1 to 4.)
(In the formula, R ₂ and y are as defined above.)
(In the formula, R ₂ and y are as defined above.)

3. The fluorene novolak resin reacts a fluorenone compound represented by the following general formula (4) with 9,9-bis (hydroxyaryl) fluorene represented by the following general formula (5) in the presence of an acidic catalyst. Obtained by: 1. Or 2. The cyanate ester compound described in 1.
(Wherein R ₂ and y are as defined above.)
(In the formula, Ar, R ₁ , R ₂ , m, x, and y are as defined above.)

  4). The mass average molecular weight Mw is 200-5000. ~ 3. The cyanate ester compound as described in any one of these.

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

  6.1. ~ 4. 5 further including at least one selected from the group consisting of a cyanate ester compound other than the cyanate ester compound according to any one of the above, an epoxy resin, an oxetane resin, and a compound having a polymerizable unsaturated group. . The curable resin composition described in 1.

  7.5. Or 6. A cured product obtained by curing the curable resin composition described in 1.

  8.5. Or 6. A prepreg for a structural material, which is obtained by impregnating or coating a curable resin composition described in 1 above on a substrate and drying.

  9.5. Or 6. A sealing material comprising the curable resin composition described in 1.

  10.5. Or 6. A fiber-reinforced composite material comprising the curable resin composition described in 1.

  11.5. Or 6. An adhesive comprising the curable resin composition described in 1.

  According to the present invention, by using a novel cyanate ester compound, a curable resin composition or a cured product having excellent flame retardancy and heat resistance can be realized.

4 is a GPC chart of the fluorene novolak resin obtained in Example 1. FIG. 4 is a GPC chart of the cyanate ester compound FNCN obtained in Example 1. FIG. 3 is an FT-IR chart of the fluorene novolak resin and cyanate ester compound FNCN obtained in Example 1. FIG.

  The present invention is a cyanate ester compound obtained by cyanating a fluorene novolak resin, and a curable resin composition comprising the cyanate ester compound.

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

<Fluorene novolac resin>
The fluorene novolak resin used as the raw material of the cyanate ester compound of the present invention is not particularly limited as long as it is a novolak resin having a fluorene structure. For example, according to JP 2011-219465 A, the fluorene novolak resin is represented by the following general formula (4). It can be obtained by reacting a fluorenone compound with 9,9-bis (hydroxyaryl) fluorene represented by the following general formula (5) in the presence of an acidic catalyst.
(Wherein R ₂ and y are as defined above.)
(In the formula, Ar, R ₁ , R ₂ , m, x, and y are as defined above.)

  Examples of the fluorenone compound represented by the general formula (4) used in the production of the fluorene novolak resin include fluorenone. The purity of the fluorenones is not particularly limited, but is usually 95% by mass or more, preferably 98% by mass or more, and more preferably 99% by mass or more.

  Examples of the 9,9-bis (hydroxyaryl) fluorenes represented by the general formula (5) used in the production of the fluorene novolak resin include 9,9-bis (4-hydroxyphenyl) fluorene, -Bis (3-methyl-4-hydroxyphenyl) fluorene, 9,9-bis (3,5-dimethyl-4-hydroxyphenyl) fluorene, 9,9-bis (3-phenyl-4-hydroxyphenyl) fluorene, 9,9-bis (3,4-dihydroxyphenyl) fluorene, 9,9-bis [6- (2-hydroxynaphthyl)] fluorene (or 6,6- (9-fluorenylidene) -di (2-naphthol)) 9,9-bis [1- (6-hydroxynaphthyl)] fluorene (or 5,5- (9-fluorenylidene) -di (2-naphthol)) 9,9-bis [1- (5-hydroxy-naphthyl)] fluorene (or 5,5- (9-fluorenylidene) - di (1-naphthol)) and the like. The 9,9-bis (hydroxyaryl) fluorenes represented by the general formula (5) may be commercially available, and can be used in a conventional manner (for example, fluorenone in the presence of an acid catalyst and thiols). You may use what was manufactured by the method (The method as described in Unexamined-Japanese-Patent No. 2007-99741) etc. which react with corresponding phenols (Phenol, cresol, naphthol, etc.).

  The acidic catalyst used in the production of the fluorene novolak resin can be appropriately selected from known inorganic acids and organic acids. For example, inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid, hydrofluoric 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, Examples thereof include organic acids such as benzenesulfonic acid, naphthalenesulfonic acid and naphthalene disulfonic acid, and solid acids such as silicotungstic acid, phosphotungstic acid, silicomolybdic acid, phosphomolybdic acid and ion exchange resins. Among these, sulfuric acid, sulfonic acid, and solid 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 used is 1 mol of the total amount of the fluorenone compound represented by the general formula (4) and the 9,9-bis (hydroxyaryl) fluorene represented by the general formula (5). 0.05 to 200 mol, preferably 0.5 to 80 mol, more preferably 1 to 50 mol.

In the production of the fluorene novolac resin, in addition to the acidic catalyst, thiols may be used in combination as a cocatalyst. When an acidic catalyst and thiols are combined, the reaction proceeds efficiently.

  Examples of thiols include conventional thiols that function as promoters, such as thioacetic acid, β-mercaptopropionic acid, α-lucaptopropionic acid, thioglycolic acid, thiooxalic acid, mercaptosuccinic acid, mercaptobenzoic acid and the like. Examples thereof include alkyl mercaptans such as carboxylic acid, methyl mercaptan, ethyl mercaptan, propyl mercaptan, isopropyl mercaptan, n-butyl mercaptan, dodecyl mercaptan, and aralkyl mercaptans such as benzyl mercaptan. Of these thiols, mercaptocarboxylic acids such as β-mercaptopropionic acid and alkyl mercaptans are preferred, and mercaptocarboxylic acids are particularly preferred. These can be used alone or in combination of two or more.

  The amount of the thiols used is 100 parts by mass with respect to the total amount of the fluorenone compound represented by the general formula (4) and the 9,9-bis (hydroxyaryl) fluorenes represented by the general formula (5). 0.001 to 0.8 parts by mass, preferably 0.005 to 0.5 parts by mass, and more preferably 0.007 to 0.3 parts by mass.

  If necessary, a solvent inert to the reaction can also be used. Examples of the solvent include aromatic hydrocarbon solvents such as toluene, ethylbenzene and xylene, alcohol solvents such as methanol, ethanol and isopropanol, ether solvents such as diethyl ether, tetrahydrofuran and dioxane, dichloromethane, chloroform and carbon tetrachloride. And organic solvents such as halogenated hydrocarbon solvents and the like. These can be used alone or in combination of two or more.

  The amount of the solvent used is based on 1 part by mass of the total amount of the fluorenone compound represented by the general formula (4) and the 9,9-bis (hydroxyaryl) fluorene represented by the general formula (5). It is 0.1-100 mass parts, Preferably it is 0.5-30 mass parts, More preferably, it is 1-10 mass parts.

  The reaction temperature in the above reaction is 0 to 150 ° C, preferably 10 to 120 ° C, more preferably 20 to 100 ° C.

  The reaction time in the reaction is 30 minutes to 120 hours, preferably 1 to 96 hours, more preferably 3 to 48 hours.

  In the reaction, the amount of 9,9-bis (hydroxyaryl) fluorene represented by the general formula (5) is 1 to 1 mol per 1 mol of the fluorenone compound represented by the general formula (4). 1000 mol, preferably 3 to 500 mol, more preferably 5 to 200 mol.

  The reaction may be performed with stirring, may be performed 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 completion of the reaction includes unreacted fluorenone compound represented by the general formula (4), unreacted 9,9-bis (hydroxyaryl) fluorenes represented by the general formula (5), Catalysts (acidic catalysts, thiols), side reaction products and the like are included. Therefore, it may be separated and purified by a conventional method, for example, a separation means such as neutralization, washing with water, filtration, concentration, extraction, crystallization, recrystallization, column chromatography, or a combination of these.

  The fluorene novolak resin that can be used in the present invention is obtained by reacting a fluorenone compound represented by the general formula (4) and a 9,9-bis (hydroxyaryl) fluorene represented by the general formula (5). Can be represented by the following general formula (6).

(In the formula, Ar represents an aromatic ring. Each R ₁ is independently a monovalent substituent and is selected from any one of a hydrogen atom, an alkyl group and an aryl group. R ₂ is each independently monovalent. And is selected from any one of a hydrogen atom and an alkyl group having 1 to 4 carbon atoms, and R ₃ is a hydrogen atom, any one of the following general formula (2) or the following general formula (3). N represents an integer greater than or equal to 1. In this case, n may be a mixture of different compounds, m is an integer of ₁ to 3. x can be substituted for R ₁ of Ar. (Y represents an integer of 1 to 4 each independently)
(In the formula, R ₂ and y are as defined above.)
(In the formula, R ₂ and y are as defined above.)

<Cyanate ester compound>
The cyanate ester compound of the present invention can be obtained by cyanating the hydroxy group of the above resin. The cyanating method is not particularly limited, and a known method can be applied. Specifically, a method in which a fluorene novolak resin and cyanogen halide are reacted in a solvent in the presence of a basic compound, and in the solvent, in the presence of a base, the cyanogen halide is always present in excess in excess of the base. Then, a method of reacting a fluorene novolac resin and a cyanogen halide (US Pat. No. 3,553,244), or a tertiary amine as a base and using this in excess of the cyanogen halide, in the presence of a solvent in the fluorene novolac resin, After adding a tertiary amine, a cyan halide is added dropwise, or a cyanide halide and a tertiary amine are added dropwise together (Patent No. 3319061), a continuous plug flow method, a fluorene novolac resin, a trialkylamine And a method of reacting with cyanogen halide (Japanese Patent No. 3905559), A method of treating a tert-ammonium halide produced as a by-product when a non-novolak resin and a cyanogen halide are reacted in a non-aqueous solution in the presence of a tert-amine with a cation and an anion exchange pair (Japanese Patent No. 4055210), In the presence of water and a solvent capable of liquid separation, a fluorene novolac resin was reacted with a tertiary amine and a cyanogen halide added at the same time, followed by washing with water and separation from the resulting solution. A method of precipitation purification using a poor solvent for alcohols or hydrocarbons (Patent No. 299954), and further, a fluorene novolac resin, a cyanogen halide, and a tertiary amine in a two-phase solvent of water and an organic solvent. The cyanate ester compound of the present invention can be obtained by a method of reacting under acidic conditions (Japanese Patent No. 5026727). That.

When the above-described method of reacting a fluorene novolak resin and a cyanide halide in a solvent in the presence of a basic compound is used, the reaction substrate fluorene novolak resin is either a cyanide halide solution or a basic compound solution. After dissolving in advance, the cyanide halide solution and the basic compound solution are brought into contact with each other.
The cyan halide solution and the basic compound solution are brought into contact with each other as follows: (A) a method in which the basic compound solution is poured into the stirred cyan halide solution, and (B) a basic mixture that is stirred and mixed. Examples include a method in which a cyan halide solution is poured into a compound solution, and a method (C) in which a cyan halide solution and a basic compound solution are continuously or alternately supplied.
Among the methods (A) to (C), side reactions are suppressed and a higher purity cyanate ester compound can be obtained in a high yield. Therefore, the method (A) is preferable.
Moreover, the contact method of the said cyanogen halide solution and a basic compound solution can be performed either in a semi-batch format or a continuous flow format.
In particular, when the method (A) is used, the reaction can be completed without leaving the hydroxy group of the fluorene novolak resin, and a higher purity cyanate compound can be obtained in a high yield. From this, it is preferable to divide and drop the basic compound. The number of divisions is not particularly limited, but is preferably 1 to 5 times. In addition, the type of basic compound may be the same or different for each division.

  Examples of the cyanogen halide used in the present invention include cyanogen chloride and cyanogen bromide. As the cyanide halide, a cyanide 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. In addition, a reaction liquid containing cyanogen halide obtained by reacting hydrogen cyanide or metal cyanide with halogen can be used as it is.

The amount of cyanogen halide used in the cyanate formation step of the present invention is 0.5 to 5 mol, preferably 1.0 to 3.5 mol, per mol of hydroxy group of the fluorene novolak resin.
The reason is to increase the yield of the cyanate ester compound without leaving unreacted fluorene novolak resin.

  Solvents used for the cyanogen halide solution include ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, aliphatic solvents such as n-hexane, cyclohexane, isooctane, cyclohexanone, cyclopentanone, and 2-butanone, benzene, and toluene. , Aromatic solvents such as xylene, diethyl ether, dimethyl cellosolve, diglyme, tetrahydrofuran, methyltetrahydrofuran, dioxane, tetraethylene glycol dimethyl ether and other ether solvents, dichloromethane, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, chlorobenzene, bromo Halogenated hydrocarbon solvents such as benzene, methanol, ethanol, isopropanol, methylsolvosolve, propylene glycol mono Alcohol solvents such as tilether, aprotic polar solvents such as N, N-dimethylformamide, N-methylpyrrolidone, 1,3-dimethyl-2-imidazolidone and dimethyl sulfoxide, nitrile solvents such as acetonitrile and benzonitrile, nitromethane Nitro solvents such as nitrobenzene, ester solvents such as ethyl acetate and ethyl benzoate, hydrocarbon solvents such as cyclohexane, water solvents and the like can be used. Can be used in combination.

  As the basic compound used in the cyanate formation step of the present invention, either an organic or inorganic base can be used.

  Examples of organic bases include 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 because the target product can be obtained with high yield.

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

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

The usage-amount of the said inorganic base is 1.0-5.0 mol normally with respect to 1 mol of hydroxy groups of a fluorene novolak resin, Preferably it is 1.0-3.5 mol.
The reason is to increase the yield of the cyanate ester compound without leaving unreacted fluorene 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.

As a usage-amount of the solvent used for a basic compound solution, when dissolving a fluorene novolak resin in a basic compound solution, it is 0.1-100 mass parts normally with respect to 1 mass part of fluorene novolak resins, Preferably it is 0.5. -50 mass parts.
When the fluorene novolac resin is not dissolved in the basic compound solution, the amount is usually 0.1 to 100 parts by mass, preferably 0.25 to 50 parts by mass with respect to 1 part by mass of the basic compound.

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

  The water for dissolving the basic compound 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. . In order to efficiently obtain the target cyanate ester compound, it is preferable to use distilled water or deionized water with less impurities.

  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 securing the reaction rate. Of these, tertiary amines with few side reactions are preferred. The tertiary amine may be any of alkylamine, arylamine, and cycloalkylamine. Specifically, 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-diazabicyclo [5.4.0] -7-undecene, 1,5-diazabicyclo [4.3.0] -5-nonene. . Among these, trimethylamine, triethylamine, tri-n-butylamine, and diisopropylethylamine are more preferable, and triethylamine is particularly preferable because the target product can be obtained with high solubility and yield in water.

  The total amount of the solvent used in the cyanate formation step of the present invention is 2.5 to 100 parts by mass with respect to 1 part by mass of the fluorene novolac resin, so that the fluorene novolac resin is uniformly dissolved and the cyanate ester compound is efficiently used. It is preferable from the viewpoint of manufacturing well.

In the cyanating 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 pH below 7. This is because by suppressing the pH to less than 7, the production of by-products such as a polymer of imide carbonate and cyanate ester compound is suppressed, and the cyanate ester compound can be produced efficiently. In order to keep the pH of the reaction solution below 7, it is preferable to add an acid. As the method, an acid is added to the cyanogen halide solution immediately before the cyanation step, and a pH meter is used as needed during the reaction. However, it is preferable to add an acid to the reaction system so as to keep the pH below 7.
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.

  The reaction temperature in the cyanation step of the present invention is such that byproducts such as imide carbonate, a polymer of cyanate ester compound, and dialkylcyanoamide, condensation of the reaction solution, and cyanide chloride as cyanide halide are used. From the viewpoint of suppressing the volatilization of cyanogen chloride, it is usually -20 to + 50 ° C, preferably -15 to 15 ° C, more preferably -10 to 10 ° C.

The reaction pressure in the cyanation step of the present invention may be normal pressure or increased pressure. If necessary, an inert gas such as nitrogen, helium, or argon may be passed through the system.
Moreover, although reaction time is not specifically limited, 1 minute-20 hours are preferable as dropping time in the case of the said contact method being (A) and (B), and contact time in the case of (C), 3 minutes-10 hours Is more preferable. Furthermore, it is preferable to stir while maintaining the reaction temperature for 10 minutes to 10 hours thereafter.
By setting it as such a range, the target cyanate ester compound can be obtained economically and industrially.

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

  After completion of the reaction, the intended cyanate ester compound can be isolated by carrying out ordinary post-treatment operations and, if desired, separation / purification operations. Specifically, an organic solvent layer containing a cyanate ester compound is separated from the reaction solution, washed with water, concentrated, precipitated or crystallized, or washed with water and then replaced with a solvent. At the time of washing, in order to remove excess amines, a method using an acidic aqueous solution such as dilute hydrochloric acid is also employed. In order to remove water from the sufficiently washed reaction solution, a drying operation can be performed using a general method such as sodium sulfate or magnesium sulfate. 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 a temperature of 90 ° C. or lower under reduced pressure. In precipitation or crystallization, a solvent having low solubility can be used. For example, an ether solvent, a hydrocarbon solvent such as hexane, or an alcohol solvent may be dropped into the reaction solution, or a reverse pouring method may be employed. In order to wash the obtained crude product, a method of washing the concentrate of the reaction solution and the precipitated crystals with an ether solvent, a hydrocarbon solvent such as hexane, or an alcohol solvent can be employed. The crystals obtained by concentrating the reaction solution can be dissolved again and then recrystallized. In the case of crystallization, the reaction solution may be simply concentrated or cooled.

  When the cyanate ester compound of the present invention is obtained by cyanating a fluorenone novolak resin represented by the general formula (6), it can be represented by the following general formula (1).

(In the formula, Ar, R ₁ , R ₂ , R ₃ , n, m, x, and y are as defined above.)
(In the formula, R ₂ and y are as defined above.)
(In the formula, R ₂ and y are as defined above.)

  Although the weight average molecular weight Mw of the cyanate ester compound of this invention is not specifically limited, It is preferable that it is 200-5000, More preferably, it is 300-3000, More preferably, it is 300-2000.

  The obtained cyanate ester 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. Byproducts such as dialkylcyanoamide in the cyanate ester compound and volatile components such as residual solvent can be quantitatively analyzed by gas chromatography. Halogen compounds remaining in the cyanate ester compound can be identified by a liquid chromatograph mass spectrometer, and can be quantitatively analyzed by potentiometric titration using a silver nitrate solution or ion chromatography after decomposition by a combustion method. . The polymerization reactivity of the cyanate ester compound can be evaluated by gelation time by a hot plate method or a torque measurement method.

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

The other cyanate compound is a compound having an aromatic moiety substituted with at least one cyanate group in the molecule, and is not particularly limited as long as it is other than the cyanate ester compound represented by the general formula (1). Not. For example, what is represented by General formula (7) is mentioned.
(In the formula, each Ar ₁ independently represents a phenylene group that may have a substituent, a naphthylene group that may have a substituent, or a biphenylene group that may have a substituent. Ra represents each. Independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, an aryl group having 6 to 12 carbon atoms which may have a substituent, and 1 carbon atom which may have a substituent -4 alkoxy group, C1-C6 alkyl group and C6-C12 aryl group optionally having a substituent bonded thereto or C1-C6 alkyl group and C6 may have a substituent group and 12 of the aryl group is bonded is selected from any one of an alkyl aryl group .p represents the number of cyanate groups bonded to Ar _1, is an integer from 1 to 3 .q represents the number of Ra to bind to Ar _1, when Ar ₁ is a phenylene group 4 When p is a naphthylene group, it is 6-p, and when it is a biphenylene group, it is 8-p, t represents an average number of repetitions, an integer of 0 to 50, and a mixture of compounds in which t is different. X is independently a single bond, a divalent organic group having 1 to 50 carbon atoms (a hydrogen atom may be substituted with a hetero atom), or a divalent organic group having 1 to 10 nitrogen atoms (—N -R-N-like), a carbonyl group (-CO-), a carboxy group (-C (= O) O-) , carbonyl dioxide group (-OC (= O) O-) , a sulfonyl group (-SO ₂ -) Alternatively, it is selected from any one of a divalent sulfur atom and a divalent oxygen atom.)

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

Specific examples of the organic group represented by X in the general formula (7) include those represented by the following general formula (8), the following general formula (9), or the following formula.
(In the formula, Ar ₂ represents one selected from a phenylene group, a naphthylene group, and a biphenylene group. Rb, Rc, Rf, and Rg are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, It is selected from any one of an aryl group having 6 to 12 carbon atoms, an aryl group substituted with at least one phenolic hydroxy group, and Rd and Re are each independently a hydrogen atom, 6 is selected from any one of an alkyl group having 6 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms, u is an integer of 0 to 5, but a mixture of compounds in which u is different. It may be.)
(In the formula, 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 group, a benzyl group, an alkoxy group having 1 to 4 carbon atoms, a hydroxy group, a trifluoromethyl group, and an aryl group substituted with at least one cyanato group, and v is an integer of 0 to 5. As shown, it may be a mixture of compounds with different v.)
(In the formula, m represents an integer of 4 to 7. Each R independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.)
Specific examples of Ar _{2 in the} general formula (8) and Ar _{3 in} the general formula (9) include 1,4-phenylene group, 1,3-phenylene group, 4,4′-biphenylene group, 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 aryl group in Rb to Rg of the general formula (8) and Ri and Rj of the general formula (9) are the same as those described 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, 1- 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-cyanphenyl) -2-phenylpropane (cyanate of 4-α-cumylphenol), 1-cyanato-4-cyclohexylbenzene, 1-cyanato-4-vinylbenzene, -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 (eugenol cyanate), methyl (4-cyanatophenyl) sulfide, 1-cyanato-3-trifluoromethylbenzene, 4-cyanatobiphenyl, 1- Cyanato-2- or 1-cyanato-4-acetylbenzene, 4-cyanatobenzaldehyde, 4-cyanatobenzoic acid methyl ester, 4-cyanatobenzoic acid phenyl ester, 1-cyanato-4-acetaminobenzene, 4-cyanato Benzophenone, 1-cyanato-2,6-di-tert-butyl Tylbenzene, 1,2-dicyanatobenzene, 1,3-dicyanatobenzene, 1,4-dicyanatobenzene, 1,4-dicyanato-2-tert-butylbenzene, 1,4-dicyanato-2,4-dimethyl Benzene, 1,4-dicyanato-2,3,4-dimethylbenzene, 1,3-dicyanato-2,4,6-trimethylbenzene, 1,3-dicyanato-5-methylbenzene, 1-cyanato or 2-si Anatonaphthalene, 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'-dicyanatobiphenyl, 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, -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-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-cyanato Phenyl) heptane 3,3-bis (4-cyanatophenyl) octane, 3,3-bis (4-cyanatophenyl) -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-dimethylhexane, 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) phenyl 1,1-bis (4-cyanatophenyl) -1-phenylethane, bis (4-cyanatophenyl) 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-si Anatophenyl) 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-dicyanatobenzophenone, 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-cyanatophenyl) adamantane, 1,3-bis (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, -Bis (N-methyl-4-cyanatoanilino) -6- (N-methylanilino) -1,3,5-triazine, bis (N-4-cyanato-2-methylphenyl) -4,4'-oxydiphthalimide 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-si Nato-3-methylphenyl) phthalimidine, 1-methyl-3,3-bis (4-cyanatophenyl) indoline-2-one, 2-phenyl-3,3-bis (4-cyanatophenyl) indoline-2 -On, phenol novolac resin or cresol novolak resin (reacted phenol, alkyl-substituted phenol or halogen-substituted phenol with formaldehyde compounds such as formalin and paraformaldehyde in an acidic solution by a known method), phenol aralkyl resin , Cresol aralkyl resin, naphthol aralkyl resin and biphenyl aralkyl resin (by a known method, a bishalogenomethyl compound represented by Ar _2- (CH ₂ Y) ₂ and a phenol compound were reacted with an acidic catalyst or without a catalyst. goods and Ar ₂ - ( H ₂ OR) expressed by such bis ₂ (alkoxymethyl) compound or Ar ₂ - (CH ₂ OH) bis (hydroxymethyl as represented by ₂₎ reacting the compound with a phenol compound in the presence of an acidic catalyst ), Phenol-modified xylene formaldehyde resin (reacted xylene formaldehyde resin and phenol compound in the presence of an acidic catalyst by a known method), modified naphthalene formaldehyde resin (Naphthalene formaldehyde resin and hydroxy by a known method) A compound obtained by reacting a substituted aromatic compound in the presence of an acidic catalyst), a phenol-modified dicyclopentadiene resin, a phenol resin having a polynaphthylene ether structure (two phenolic hydroxy groups per molecule by a known method) Having polyhydric hydroxynaphthalene Things and, although basic catalyst in the presence as a dehydration condensation) as such was cyanated phenolic resin by methods similar to those described above, and the like, but is not particularly limited. These cyanate ester compounds can be used alone or in combination.

  As the epoxy resin, generally known compounds can be used as long as they are compounds having two or more epoxy groups in one molecule. For example, bisphenol A type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol A novolac type epoxy resin, biphenyl type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, Xylene novolac type epoxy resin, naphthalene type epoxy resin, anthracene type epoxy resin, trifunctional phenol type epoxy resin, tetrafunctional phenol type epoxy resin, triglycidyl isocyanurate, glycidyl ester type epoxy resin, alicyclic epoxy resin, dicyclopentadiene Novolac epoxy resin, biphenyl novolac epoxy resin, phenol aralkyl novolac epoxy resin, naphthol aralkyl novo -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 halides thereof It is done. These epoxy resins can be used alone or in combination.

  As the oxetane resin, generally known oxetane resins can be used. For example, oxetane, 2-methyloxetane, 2,2-dimethyloxetane, 3-methyloxetane, alkyloxetane such as 3,3-dimethyloxetane, 3-methyl-3-methoxymethyloxetane, 3,3′-di (tri Fluoromethyl) perfluoxetane, 2-chloromethyloxetane, 3,3-bis (chloromethyl) oxetane, OXT-101 (trade name, manufactured by Toagosei Co., Ltd.), OXT-121 (trade name, manufactured by Toagosei Co., Ltd.) and the like. These oxetane resins can be used alone or in combination.

  As the benzoxazine compound, generally known compounds can be used as long as they have two or more dihydrobenzoxazine rings in one molecule. For example, bisphenol A type benzoxazine BA-BXZ (trade name, manufactured by Konishi Chemical) bisphenol F type benzoxazine BF-BXZ (trade name, manufactured by Konishi Chemical), bisphenol S type benzoxazine BS-BXZ (trade name, manufactured by Konishi Chemical), phenol Examples include phthalein type benzoxazine. These benzoxazine compounds can be used alone or in combination.

  As the compound having a polymerizable unsaturated group, generally known compounds can be used. For example, vinyl compounds such as ethylene, propylene, styrene, divinylbenzene, divinylbiphenyl, methyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, polypropylene glycol di (meth) acrylate, Mono- or polyhydric alcohol (meth) acrylates such as trimethylolpropane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, bisphenol Epoxy (meth) acrylates such as A-type epoxy (meth) acrylate and bisphenol F-type epoxy (meth) acrylate, benzocyclobutene resin, (bis) male De resins. These compounds having an unsaturated group can be used alone or in combination.

  In addition to the above-described compounds and resins, the curable resin composition in the present invention further contains a compound that catalyzes the polymerization of a cyanate ester, an epoxy resin, an oxetane resin, or a compound having a polymerizable unsaturated group. be able to. Examples of the polymerization catalyst include zinc octylate, zinc naphthenate, cobalt naphthenate, copper naphthenate, acetylacetone iron and the like, phenol compounds such as octylphenol and nonylphenol, 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-dihydroxymethyl Imidazole, imidazole derivatives such as 2-phenyl-4-methyl-5-hydroxymethylimidazole, dicyandiamide, benzyldimethylamine, amine compounds such as 4-methyl-N, N-dimethylbenzylamine, Honiumu phosphorus-compounds of. Also, peroxides such as epoxy-imidazole adduct compounds, benzoyl peroxide, p-chlorobenzoyl peroxide, di-t-butyl peroxide, diisopropyl peroxycarbonate, di-2-ethylhexyl peroxycarbonate, or azobis An azo compound such as isobutyronitrile may be used. Commercially available catalysts may be used such as Amicure PN-23 (manufactured by Ajinomoto Fine Techno Co., NovaCure HX-3721 (manufactured by Asahi Kasei Co., Ltd.), Fujicure FX-1000 (manufactured by Fuji Kasei Kogyo Co., Ltd.) These catalysts can be used alone or in combination.

  An inorganic filler can be used for the curable resin composition in the present invention. Examples of inorganic fillers that can be used include talc, fired clay, unfired clay, mica, E glass, A glass, NE glass, C glass, L glass, D glass, S glass, M glass G20, and short glass fiber (E glass). And glass fine powders such as T glass, D glass, S glass, and Q glass.), Hollow glass, spherical glass, silica, fused silica and other silicates, titanium oxide, alumina, gibbsite, boehmite, zinc oxide , Oxides such as 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 , Sulfates or sulfites such as calcium sulfite, zinc borate, barium metaborate, Borates such as aluminum oxide, calcium borate and sodium borate, nitrides such as aluminum nitride, boron nitride, silicon nitride and carbon nitride, carbides such as silicon carbide, titanates such as strontium titanate and barium titanate Zinc molybdate, silicone composite powder, silicone resin powder and the like. These inorganic fillers can be used alone or in combination. These can be used by increasing the filling amount by mixing different shapes (spherical or crushed molds) or different sizes.

  The inorganic filler may be further treated with a treatment agent for surface treatment in advance. 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 these, the surface treatment of spherical silica using organohalosilanes and alkylsilazanes is suitable for hydrophobizing the silica surface, and improves the dispersibility of the spherical silica in the curable resin composition. It is preferable in terms of superiority.

  Furthermore, the curable resin composition of the present invention may be a thermoplastic resin, a curing catalyst, a curing accelerator, a color pigment, an antifoaming agent, a surface conditioner, a flame retardant, an ultraviolet absorber, an antioxidant, if necessary. Contains known additives such as photopolymerization initiators, fluorescent brighteners, photosensitizers, dyes, pigments, thickeners, lubricants, flow regulators, dispersants, leveling agents, brighteners, polymerization inhibitors, etc. It may be. Moreover, you may contain the solvent as needed. These optional additives can be used alone or in combination.

  As the solvent, generally known solvents can be used. For example, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, cellosolv solvents such as propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, methyl lactate, methyl acetate, ethyl acetate, butyl acetate, isoamyl acetate, ethyl lactate And ester solvents such as methyl methoxypropionate and methyl hydroxyisobutyrate, alcohol solvents such as methanol, ethanol, isopropanol and 1-ethoxy-2-propanol, and aromatic hydrocarbons such as toluene, xylene and anisole. It is done. These solvents can be used alone or in combination.

  The curable resin composition in the present invention includes the above-described cyanate ester compound and, if necessary, other cyanate ester compounds, epoxy resins, oxetane resins, benzoxazine compounds, and / or polymerizable unsaturated groups. Can be obtained by mixing together with a solvent using a known mixer such as a high speed mixer, a nauter mixer, a ribbon blender, a kneader, an intensive mixer, a universal mixer, a dissolver, a static mixer, etc. it can. The mixing method of the cyanate ester compound, various additives, and the solvent during mixing is not particularly limited.

  The curable resin composition according to the present invention can be made into a cured product by curing with heat or light. The cured product can be obtained by melting the curable resin composition or dissolving it in a solvent, then pouring it into a mold and curing it under normal conditions. In the case of thermosetting, if the curing temperature is too low, curing does not proceed, and if it is too high, the cured product is deteriorated. Therefore, it is preferably in the range of 120 ° C to 300 ° C.

<Use of curable resin composition>
A sealing material can be produced using the curable resin composition of the present invention. As a method for producing the sealing material, generally known methods can be appropriately applied and are not particularly limited. For example, a sealing material can be manufactured by mixing the above-described curable resin composition and various known additives or solvents for sealing material applications using a known mixer. In addition, the mixing method of the cyanate ester compound, various additives, and the solvent at the time of mixing can generally apply a well-known method suitably, and is not specifically limited.

  Moreover, a prepreg can be manufactured by impregnating or apply | coating an above-described curable resin composition to an inorganic and / or organic fiber base material.

  The base material is not particularly limited, but glass fiber base materials such as glass woven fabric and glass nonwoven fabric, polyamide resin fibers, aromatic polyamide resin fibers, polyamide resin fibers such as wholly aromatic polyamide resin fibers, polyester resin fibers, Synthetic fiber substrate, kraft paper, cotton linter composed of woven or non-woven fabric mainly composed of polyester resin fiber such as aromatic polyester resin fiber, wholly aromatic polyester resin fiber, polyimide resin fiber, fluororesin fiber, etc. Examples thereof include organic fiber base materials such as paper base materials mainly composed of paper, mixed paper of linter and kraft pulp, and the like. These known materials can be appropriately selected and used according to the performance required for the prepreg, for example, strength, water absorption, thermal expansion coefficient, and the like.

  Although the glass which comprises the said glass fiber base material is not specifically limited, For example, E glass, C glass, A glass, S glass, D glass, NE glass, T glass, H glass etc. are mentioned.

  The method for producing the prepreg is not particularly limited, and generally known methods can be appropriately applied. For example, a resin varnish is prepared using the curable resin composition described above, and a method of immersing the substrate in the resin varnish, a method of applying with various coaters, a method of spraying with a spray, etc. are applied to produce a prepreg. Can do. Among these, the method of immersing the base material in the resin varnish is preferable. Thereby, the impregnation property of the resin composition with respect to a base material can be improved. In addition, when a base material is immersed in a resin varnish, a normal impregnation coating equipment can be used. For example, a method of manufacturing a prepreg by impregnating a resin composition varnish into an inorganic and / or organic fiber base material, drying and forming a B-stage can be applied.

  Moreover, the curable resin composition of this invention can also be used for a metal-clad laminated board and a multilayer board use. As a method for producing these laminated plates and the like, generally known ones can be appropriately applied and are not particularly limited. For example, a laminate can be obtained by laminating the above prepreg and a metal foil and then heat-pressing the laminate. At this time, although the temperature to heat is not specifically limited, 65-300 degreeC is preferable normally and 120-270 degreeC is more preferable. Moreover, the pressure to pressurize is not particularly limited, but usually 2 to 5 MPa is preferable, and 2.5 to 4 MPa is more preferable.

  Moreover, a fiber reinforced composite material can be manufactured using the curable resin composition by this invention. As the reinforcing fibers, carbon fibers, glass fibers, aramid fibers, boron fibers, PBO fibers, high-strength polyethylene fibers, alumina fibers, silicon carbide fibers, and the like 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, choppeds, and the like. In addition, as a form of the reinforcing fiber, a preform (a laminate of woven fabrics made of reinforcing fibers, or a structure obtained by stitching them together with stitch yarn, or a fiber structure such as a three-dimensional woven fabric or a braided fabric) is applied. You can also. Specific examples of methods for producing these fiber-reinforced composite materials include a liquid composite molding method, a resin film infusion method, a filament winding method, a hand layup method, and a pultrusion method. Among these, the resin transfer molding method, which is one of the liquid composite molding methods, is to set materials other than preforms such as metal plates, foam cores, and honeycomb cores in the mold in advance. Therefore, it can be used in various applications, and is therefore preferably used when a composite material having a relatively complicated shape is mass-produced in a short time.

  Since the curable resin composition according to the present invention has excellent low thermal expansion, flame retardancy and heat resistance, it is extremely useful as a highly functional polymer material, and is excellent in thermal, electrical and mechanical properties. As well as electrical insulation materials, sealing materials, adhesives, laminate materials, resists, build-up laminate materials, civil engineering / architecture, electricity / electronics, automobiles, railways, ships, aircraft, sporting goods, arts / crafts, etc. It is preferably used for a fixing material, a structural member, a reinforcing agent, a molding material, etc. in the field. Among these, it is suitable for electrical insulating materials, semiconductor encapsulating materials, adhesives for electronic components, aircraft structural members, satellite structural members, and railway vehicle structural members that require low thermal expansion, 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 weight average molecular weight Mw of cyanate ester compound)
10 μL of a solution in which 1 g of cyanate ester compound was dissolved in 100 g of tetrahydrofuran (solvent) was injected into high performance liquid chromatography (high performance liquid chromatograph LachromElite manufactured by Hitachi High-Technologies Corporation) for analysis. Two columns are TSKgel GMH _HR- M (length 30 cm × inner diameter 7.8 mm) 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 using polystyrene as a standard substance by the GPC method.

(Example 1) Synthesis of cyanate ester compound (abbreviated as FNCN) of fluorene novolak resin

<Synthesis of FNCN>
170 g of fluorene novolac resin (NV-203-R4 OH group equivalent 194 g / eq., Manufactured by Osaka Gas Chemical Co., Ltd.) (0.88 mol in terms of OH group) (weight average molecular weight Mw410: GPC chart is shown in FIG. 1) and triethylamine 66. 5 g (0.66 mol) (0.75 mol with respect to 1 mol of hydroxy group) was dissolved in 1100 g of dichloromethane, and this was used as solution 1.
86.2 g (1.40 mol) of cyanogen chloride (1.6 mol with respect to 1 mol of hydroxy group), 201.1 g of dichloromethane, 133.1 g (1.31 mol) of 36% hydrochloric acid (1. 5 mol) and 825.2 g of water were mixed into a 3 L three-necked flask, and the solution 1 was poured using a dropping funnel over 75 minutes while maintaining the liquid temperature at −2 to −0.5 ° C. with stirring. I gave it. After the completion of the pouring of solution 1, after stirring at the same temperature for 30 minutes, a solution (solution 2) in which 133 g (1.31 mol) of triethylamine (1.5 mol with respect to 1 mol of hydroxy group) was dissolved in 133 g of dichloromethane was obtained. It was poured over 38 minutes. After the end of pouring the solution 2, the reaction was completed by stirring at the same temperature for 30 minutes.
Thereafter, the reaction solution was allowed to stand to separate an organic phase and an aqueous phase. The obtained organic phase was washed 5 times with 500 g of water. The electric conductivity of the waste water in the fifth washing with water was 20 μS / cm, and it was confirmed that the ionic compounds that could be removed were sufficiently removed by washing with water.
The organic phase after washing with water was concentrated under reduced pressure and finally concentrated to dryness at 90 ° C. for 1 hour to obtain 190 g of the intended cyanate ester compound FNCN (orange viscous product). The obtained cyanate ester compound FNCN had a weight average molecular weight Mw of 510. A GPC chart is shown in FIG. Further, the IR spectrum of FNCN showed an absorption of 2250 cm ⁻¹ (cyanate ester group) and no absorption of a hydroxy group. An IR chart is shown in FIG.

(Example 2)
<Preparation of curable resin composition and creation of cured product>
100 parts by mass of the cyanate ester compound FNCN obtained in Example 1 was put into an eggplant-shaped flask, heated and melted at 150 ° C., degassed with a vacuum pump, and then zinc octylate (trade name Nikka, manufactured by Nippon Chemical Industry Co., Ltd.). A curable resin composition was prepared by adding 0.1 part by mass of zinc octate (metal content: 18%) and shaking and mixing for 1 minute.
The obtained curable resin composition was poured into a mold made of an aluminum plate, copper foil, and fluorine-coated stainless steel, placed in an oven, and the resin was made uniform at 150 ° C., then at 220 ° C. for 90 minutes, 20 kg / It hardened | cured by the vacuum press at cm < ² >, and the hardened | cured material of 1 side 100mm and thickness 1.5mm was obtained.

(Example 3)
In Example 2, a cured product was obtained in the same manner as in Example 2 except that heating was performed at 220 ° C. for 6 hours after vacuum pressing at 220 ° C. for 90 minutes and 20 kg / cm ² .

(Comparative Example 1)
In Example 2, instead of using 100 parts by mass of FNCN, 100 parts by mass of 2,2-bis (4-cyanatophenyl) propane (trade name skylex manufactured by Mitsubishi Gas Chemical) was used, and zinc octylate (Nippon Chemical Industry Co., Ltd.) was used. A cured product was obtained in the same manner as in Example 2 except that the trade name, zinc nikka octate, metal content 18%) was not added.

(Comparative Example 2)
In Example 3, instead of using 100 parts by mass of FNCN, 100 parts by mass of 2,2-bis (4-cyanatophenyl) propane (trade name skylex manufactured by Mitsubishi Gas Chemical) was used, and zinc octylate (Nippon Chemical Industry Co., Ltd.) was used. A cured product was obtained in the same manner as in Example 3 except that no trade mark, zinc nikka octate, metal content 18%) was added.

(Comparative Example 3)
In Example 2, instead of using 100 parts by mass of FNCN, 100 parts by mass of 2,2-bis (4-cyanatophenyl) propane (trade name skylex manufactured by Mitsubishi Gas Chemical) was used, and zinc octylate (Nippon Chemical Industry Co., Ltd.) was used. A cured product was obtained in the same manner as in Example 2 except that 0.05 part by mass of trade name Zinc Octamate, trade name, metal content 18%) was used.

(Comparative Example 4)
In Example 3, instead of using 100 parts by mass of FNCN, 100 parts by mass of 2,2-bis (4-cyanatophenyl) propane (trade name skylex manufactured by Mitsubishi Gas Chemical) was used, and zinc octylate (Nippon Chemical Industry Co., Ltd.) was used. A cured product was obtained in the same manner as in Example 3 except that 0.05 part by mass of trade name, zinc nikka octate, trade name, metal content 18%) was used.

The characteristics of each cured product obtained as described above were evaluated by the following methods.
Glass transition temperature (Tg): Based on JIS-K7244-3 (JIS C6481), using a dynamic viscoelasticity measuring device (Q800 manufactured by TA Instruments Japan Co., Ltd.), start temperature 30 ° C., end Dynamic viscoelasticity was measured at a temperature of 400 ° C., a heating rate of 10 ° C./min, and a measurement frequency of 10 Hz, and the loss elastic modulus (E ″) obtained at that time was taken as the glass transition temperature.
Mass reduction rate (%): Based on JIS-K7120-1987, using a differential thermothermal mass simultaneous measurement device (TG / DTA6200, manufactured by SII NanoTechnology Co., Ltd.), test piece 3 mm × 3 mm × 1.5 mm, start The mass was measured at a temperature of 30 ° C., an end temperature of 550 ° C., a heating rate of 10 ° C./min, and a nitrogen atmosphere, and the mass reduction rate at 500 ° C. was calculated based on the following equation.
Mass reduction rate (%) = (DE) / D × 100
D represents the mass at the starting temperature, and E represents the mass at 500 ° C.
Here, the flame retardancy in the present invention is separately defined as a large amount of residue during pyrolysis, that is, a low mass reduction rate.
The evaluation results are shown in Table 1.

  As is clear from Table 1, the cured product of the curable resin composition using the cyanate of the fluorene novolak resin of the present invention is more difficult than the conventional product using the cyanate ester compound. It was confirmed to have flammability and heat resistance.

Claims (10)

A cyanate ester compound having a structure represented by the following general formula (1) .
(In the formula, Ar represents an aromatic ring. Each R ₁ is independently a monovalent substituent and is selected from any one of a hydrogen atom, an alkyl group and an aryl group. R ₂ is each independently monovalent. And is selected from any one of a hydrogen atom and an alkyl group having 1 to 4 carbon atoms, and R ₃ is a hydrogen atom, any one of the following general formula (2) or the following general formula (3). N is an integer of 1 or more, m is an integer of 1 to 3, x is a number that can be substituted for R ₁ of Ar, and y is independently an integer of 1 to 4. Represents.)
(In the formula, R ₂ and y are as defined above.)
(In the formula, R ₂ and y are as defined above.) A fluorenone compound represented by the following general formula (4), that obtained by the 9,9-bis (hydroxyaryl) fluorene compound represented by the following general formula (5) is reacted in the presence of an acidic catalyst comprising the step of cyanated fluorene novolak resin, the manufacturing method of the uninstall ester compound.
(Wherein R ₂ and y are as defined above.)
(In the formula, Ar, R ₁ , R ₂ , m, x, and y are as defined above.) The weight average molecular weight Mw of 200 to 5,000, cyanate ester compound according to claim 1. A curable resin composition comprising the cyanate ester compound according to claim 1 . It further includes at least one selected from the group consisting of a cyanate ester compound other than the cyanate ester compound according to claim 1 or 3 , an epoxy resin, an oxetane resin, and a compound having a polymerizable unsaturated group. Item 6. The curable resin composition according to Item 5. Hardened | cured material formed by hardening the curable resin composition of Claim 4 or 5 . A prepreg for a structural material, wherein the curable resin composition according to claim 4 or 5 is impregnated or coated on a substrate and dried. The sealing material containing the curable resin composition of Claim 4 or 5 . A fiber-reinforced composite material comprising the curable resin composition according to claim 4 or 5 . An adhesive comprising the curable resin composition according to claim 4 .