JP7344470B2 - Cyanate ester and resin composition - Google Patents

Description

The present invention relates to cyanate esters and resin compositions.

Cyanate ester is known as a thermosetting resin that forms a triazine ring during curing. Cured products obtained from cyanate esters have excellent properties such as a high glass transition temperature, low dielectric constant and dielectric loss tangent, and excellent electrical insulation and flame retardancy. Therefore, cyanate esters have been widely used as raw materials for electrical and electronic materials, structural composite materials, adhesives, and various other functional polymer materials.

Under these circumstances, development of cyanate esters having more excellent properties is underway. For example, Patent Document 1 discloses that it is possible to realize a cured product that has a low dielectric constant and a low dielectric loss tangent, and has excellent flame retardancy and heat resistance, and also has a relatively low viscosity and excellent solvent solubility. A cyanate ester compound obtained by cyanating a phenol-modified xylene formaldehyde resin has been disclosed as a new cyanate ester compound that has excellent handling properties.

Further, Patent Document 2 discloses a novel bifunctional cyanatophenyl type cyanate ester that is liquid at room temperature and can yield a cured product having an excellent low coefficient of thermal expansion.

WO2013/021869A1 WO2012/057144A1

As disclosed in Patent Document 1, cyanate esters having a predetermined resin skeleton are known. A cyanate ester having a resin skeleton composed of a plurality of repeating units as described above is a mixture of cyanate esters having different numbers of repeating units, and has a wide molecular weight distribution.

As a result of the studies conducted by the present inventors, it has been found that when such a mixture of cyanate esters having different numbers of repeating units is cured, the rate of increase in viscosity is not constant, such as a sudden increase in viscosity during curing. I've come to understand. If the rate of viscosity increase during curing is not constant, it may be difficult to control the curing reaction, resulting in poor handling or insufficient curing.

On the other hand, it has been found that low-molecular-weight cyanate esters without dispersion, as disclosed in Patent Document 2, pose problems in terms of weight loss rate.

The present invention has been made in view of the above problems, and provides a novel cyanate ester, which has low viscosity and excellent handling properties, has a constant viscosity increase rate during curing, and has a low weight loss rate. The present invention also aims to provide a resin composition containing the cyanate ester.

The present inventors have made extensive studies to solve the above problems. As a result, they discovered that the above problems can be solved by narrowing the dispersion, and have completed the present invention.

That is, the present invention is as follows.
[1]
It has a structure represented by the following formula (1), and the total content of n = 2 to 4 components is 80 area % or more in area % measured by gel permeation chromatography.
cyanate ester.
(In formula (1), n represents the number of repeating units. R each independently represents a hydrogen atom or a methyl group.)
[2]
In area % measured by gel permeation chromatography, the content of n≧5 components is 15 area % or less,
The cyanate ester described in [1].
[3]
In area % measured by gel permeation chromatography, the content of n = 1 component is 12 area % or less,
The cyanate ester described in [1] or [2].
[4]
The weight average molecular weight (Mw) in terms of polystyrene is 300 or more and 700 or less,
The cyanate ester according to any one of [1] to [3].
[5]
The dispersion ratio (Mw/Mn) between weight average molecular weight (Мw) and number average molecular weight (Mn) in terms of polystyrene is 1 or more and 1.5 or less,
The cyanate ester according to any one of [1] to [4].
[6]
R is a hydrogen atom,
The cyanate ester according to any one of [1] to [5].
[7]
Containing the cyanate ester according to any one of [1] to [6],
Resin composition.
[8]
Furthermore, containing a maleimide compound,
The resin composition according to [7].
[9]
Furthermore, it contains at least one selected from the group consisting of a cyanate ester resin other than the cyanate ester, a phenol resin, an epoxy resin, an oxetane resin, and a compound having a polymerizable unsaturated group.
The resin composition according to [7] or [8].
[10]
obtained by curing the resin composition according to any one of [7] to [9],
cured product.
[11]
base material and
The resin composition according to any one of [7] to [9], which is impregnated or applied to the base material;
has,
prepreg.
[12]
[7] Comprising the resin composition according to any one of [9],
Encapsulation material.
[13]
[7] Comprising the resin composition according to any one of [9] and reinforcing fibers,
Fiber reinforced composite material.
[14]
[7] Comprising the resin composition according to any one of [9],
glue.

According to the present invention, a novel cyanate ester, which has excellent handling properties due to its low viscosity, a constant viscosity increase rate during curing, and a low weight loss rate, and a resin composition containing the cyanate ester are provided. can be provided.

FIG. 2 is a graph showing the progress of curing of the cyanate esters obtained in Example 1 and Comparative Example 1, with the horizontal axis representing time and the vertical axis representing log (viscosity at time of measurement η/initial viscosity η ₀ ). It is a diagram plotting the degree of progress.

Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail, but the present invention is not limited thereto, and various modifications can be made without departing from the gist thereof. It is.

[Cyanate ester]
The cyanate ester of this embodiment has a structure represented by the following formula (1), and the total content of n = 2 to 4 components is 80 area % in area % measured by gel permeation chromatography. That's all.
(In formula (1), n represents the number of repeating units. R each independently represents a hydrogen atom or a methyl group.)

In the above formula (1), each R independently represents a hydrogen atom or a methyl group. Among these, R is preferably a hydrogen atom.

In the above formula (1), n represents the number of repeating units and is an integer of 1 or more, preferably 1 to 20. The cyanate ester of this embodiment is a mixture containing different n components in the above formula (1), including a component where n is 2, a component where n is 3, and a component where n is 4 in the above formula (1). It is a narrowly dispersed cyanate ester in which a certain component occupies the majority.

In area % measured by gel permeation chromatography, the total content of n = 2 to 4 components is 80 area % or more, preferably 82 area % or more, more preferably 85 area % or more. , more preferably 90 area % or more, particularly preferably 95 area % or more. When the total content of n=2 to 4 components is 80 area % or more, the viscosity is low and the viscosity increase rate during curing is constant. Further, the upper limit of the total content of n = 2 to 4 components is not particularly limited, but is preferably 99 area % or less, more preferably 98 area % or less, and even more preferably 97 area % or less. When the total content of n=2 to 4 components is 99% by area or less, manufacturing costs tend to be suppressed.

In area % measured by gel permeation chromatography, the content of n = 1 component is preferably 12 area % or less, more preferably 10 area % or less, still more preferably 5 area % or less, Particularly preferably, it is 3% by area or less. When the content of the n=1 component is 12 area % or less, the weight loss rate tends to decrease. Further, the lower limit of the content of n=1 component is not particularly limited, but is preferably 0.1 area% or more, more preferably 0.3 area% or more, and still more preferably 0.5 area% or more. be. When the content of n=1 component is 0.1 area % or more, manufacturing costs tend to be suppressed.

In area % measured by gel permeation chromatography, the content of n≧5 components is preferably 15 area % or less, more preferably 10 area % or less, still more preferably 5 area % or less, Particularly preferably, it is 3% by area or less. When the content of the n≧5 component is 15 area % or less, the viscosity tends to be further reduced. Further, the lower limit of the content of the n≧5 component is not particularly limited, but is preferably 1 area % or more, more preferably 1.5 area % or more, and even more preferably 2 area % or more. When the content of n≧5 components is 1% by area or more, manufacturing costs tend to be suppressed.

The content of each of the above components is determined by calculating the area of the entire chromatogram corresponding to cyanate ester and the peak area for each n component of cyanate ester from the chromatogram obtained by gel permeation chromatography. It can be expressed as the ratio of the peak area of each component to the area (area %). Measurement conditions for gel permeation chromatography include, for example, the conditions described in Examples, but are not limited thereto, and conditions that allow each component to be quantified by area % can be used as appropriate.

The weight average molecular weight (Mw) of the cyanate ester of the present embodiment in terms of polystyrene (hereinafter also simply referred to as "weight average molecular weight (Mw)") is preferably 300 or more and 700 or less, more preferably 300 or more. It is 600 or less, more preferably 350 or more and 500 or less. When the weight average molecular weight (Mw) of the cyanate ester is 300 or more, the n=1 component becomes relatively small, and the weight reduction rate tends to decrease. Furthermore, when the weight average molecular weight (Mw) of the cyanate ester is 700 or less, the n≧5 component becomes relatively small, and the viscosity tends to decrease.

Dispersion ratio (Mw/Mn) of the cyanate ester of this embodiment between the weight average molecular weight (Мw) and the number average molecular weight (Mn) in terms of polystyrene (hereinafter also simply referred to as "number average molecular weight (Mn)") is preferably 1 or more and 1.5 or less, more preferably 1 or more and 1.4 or less, still more preferably 1 or more and 1.3 or less, particularly preferably 1 or more and 1.2 or less. When the dispersion ratio (Mw/Mn) is 1.5 or less, a cyanate ester with narrower dispersion can be obtained even when the total content of n=2 to 4 components is 80 area % or more. This tends to lower the viscosity and keep the rate of viscosity increase during curing constant.

The weight average molecular weight (Mw), number average molecular weight (Mn), and dispersion ratio (Mw/Mn) of the cyanate ester can be calculated by gel permeation chromatography. Regarding the measurement conditions of gel permeation chromatography used in this case, the same conditions as those for determining the content of the n component can be used.

[Method for manufacturing cyanate ester]
The cyanate ester of this embodiment can be obtained by a production method including a cyanation step of cyanating the hydroxy group of a phenol resin represented by the following formula (2) having a skeleton similar to that of formula (1). .
(In formula (2), n represents the number of repeating units. R each independently represents a hydrogen atom or a methyl group.)

In addition, in the above formula (2), n and R can be exemplified by the same ones as in formula (1). Further, the phenol resin represented by formula (2) is not particularly limited, but for example, a mixture containing different components n in the above formula (2) can be used. In this case, the phenol resin is preferably a narrowly dispersed phenol resin in which the component in which n is 2, the component in which n is 3, and the component in which n is 4 in the above formula (2) occupy the majority.

The method for synthesizing the phenol resin is not particularly limited, and conventionally known methods can be used. For example, when synthesizing phenol novolak resin, phenol and formaldehyde are reacted in the presence of an acid catalyst, and the acid catalyst, water, and unreacted phenol are removed from the resulting reaction product to synthesize phenol novolak resin. There are several ways to obtain it.

Furthermore, as a method for narrowing the dispersion, a method of distilling the obtained phenol novolak resin and removing those having a small number of repeating units can be considered. Methods for obtaining narrowly dispersed phenolic resins are not limited to these, but include repeating reprecipitation using differences in resin solubility, repeating recrystallization, removing unnecessary components by recycling GPC, etc. Examples include a method of removing n=1 component and n≧5 component by applying a known purification method. In addition, there are methods to remove high molecular weight components by distilling the obtained phenol novolac resin and separating those with a relatively small number of repeating units, and methods to remove high molecular weight components by adding catalysts and monomers to the obtained phenol novolak resin. A method of heating at a high temperature to decompose a high molecular weight component, a method of blowing high temperature steam into the obtained phenol novolac resin to decompose a high molecular weight component, etc. can also be used as appropriate.

The method for cyanating the hydroxy group of the phenol resin is not particularly limited, and any known method can be applied. For example, there is a method in which a phenol resin and a cyanogen halide are reacted in a solvent in the presence of a basic compound. More specifically, it is preferable to dissolve the phenol resin as the reaction substrate in advance in either the cyanogen halide solution or the basic compound solution, and then bring the cyanogen halide solution and the basic compound solution into contact. The method of bringing the cyanogen halide solution and the basic compound solution into contact is not particularly limited, but examples include a method of pouring the basic compound solution into the cyanogen halide solution that has been mixed with stirring, a method of pouring the basic compound solution into the cyanogen halide solution that has been stirred and mixed, and a method that has been mixed with the base that has been stirred and mixed. Examples include a method of pouring a cyanogen halide solution into a basic compound solution, and a method of continuously supplying a cyanogen halide solution and a basic compound solution alternately or simultaneously. Among these methods, a method in which a basic compound solution is poured into a cyanogen halide solution stirred and mixed is preferred from the viewpoint of suppressing side reactions and obtaining a higher purity cyanate ester in a high yield.

The cyanogen halide used in the above production method is not particularly limited, and examples thereof include cyanogen chloride and cyanogen bromide. As the cyanogen halide, cyanogen halide obtained by a known production method such as a method of reacting hydrogen cyanide or a metal cyanide with a 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 a metal cyanide with a halogen can also be used as it is.

Further, when cyanide halide is used when cyanating a phenol resin, the amount of cyanogen halide used is preferably 1.0 to 5.0 mol, more preferably is 1.0 to 3.5 mol.

The solvent used for the cyanogen halide solution is not particularly limited, but includes, for example, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and cyclopentanone; aliphatic solvents such as n-hexane, cyclohexane, and isooctane; Aromatic solvents such as benzene, toluene, and xylene; Ether solvents such as diethyl ether, dimethyl cellosolve, diglyme, tetrahydrofuran, methyltetrahydrofuran, dioxane, and tetraethylene glycol dimethyl ether; dichloromethane, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, Halogenated hydrocarbon solvents such as chlorobenzene and bromobenzene; Alcohol solvents such as methanol, ethanol, isopropanol, methylsolsolve, propylene glycol monomethyl ether; N,N-dimethylformamide, N-methylpyrrolidone, 1,3-dimethyl Aprotic polar solvents such as -2-imidazolidone and dimethyl sulfoxide; Nitrile solvents such as acetonitrile and benzonitrile; Nitro solvents such as nitromethane and nitrobenzene; Ester solvents such as ethyl acetate and ethyl benzoate; Water solvents, etc. can also be used. These can be used alone or in combination of two or more types depending on the reaction substrate.

Basic compounds include, but are not particularly limited to, trimethylamine, triethylamine, tri-n-butylamine, triamylamine, diisopropylethylamine, diethyl-n-butylamine, methyldi-n-butylamine, and methylethyl-n-butylamine. , dodecyldimethylamine, tribenzylamine, triethanolamine, N,N-dimethylaniline, N,N-diethylaniline, diphenylmethylamine, pyridine, diethylcyclohexylamine, tricyclohexylamine, 1,4-diazabicyclo[2.2 .2] Organic bases such as tertiary amines such as octane, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]-5-nonene; or water Examples include inorganic bases such as sodium oxide, potassium hydroxide, and lithium hydroxide.

Among these, trimethylamine, triethylamine, tri-n-butylamine, and diisopropylethylamine are more preferred because the desired product can be obtained in good yield, and organic bases such as triethylamine and inorganic bases such as sodium hydroxide are preferred.

The amount of the basic compound used is preferably 1.0 to 8.0 mol, more preferably 1.0 to 5.0 mol, even more preferably 1.0 to 5.0 mol, per mol of hydroxyl group of the phenol resin. It is 3.5 mol. When the amount of the basic compound used is within the above range, the yield of cyanate ester tends to be further improved.

The basic compound can be used as a solution dissolved in a solvent such as an organic solvent or water.

The progress of the reaction when cyanating a phenol resin can be analyzed by liquid chromatography, IR spectroscopy, or the like. Further, volatile components such as dicyanide and dialkylcyanoamide produced as by-products in the cyanation step can be analyzed by gas chromatography.

The operation for isolating the desired cyanate ester from the reaction solution obtained in the cyanation step is not particularly limited, and ordinary post-treatment operations and separation/purification operations can be used. Specifically, examples include a method in which an organic solvent layer containing a cyanate ester is separated from a reaction solution, washed with water, concentrated, precipitated or crystallized, or washed with water and then replaced with a solvent.

During cleaning, a method using an acidic aqueous solution such as dilute hydrochloric acid is also used to remove excess amines. In order to remove moisture from the thoroughly washed reaction solution, a drying operation can be performed using a common method such as sodium sulfate or magnesium sulfate. During concentration and solvent replacement, in order to suppress polymerization of the cyanate ester, it is preferable to distill off the organic solvent by heating to a temperature of 90° C. or lower under reduced pressure.

During precipitation or crystallization, a solvent with low solubility can be used. For example, a method can be adopted in which an ether solvent, a hydrocarbon solvent such as hexane, or an alcohol solvent is dripped into the reaction solution or is poured back into the reaction solution.

In addition, in order to wash the obtained crude product, a method may be adopted in which the concentrate of the reaction solution or precipitated crystals is washed with an ether solvent, a hydrocarbon solvent such as hexane, or an alcohol solvent. can. It is also possible to re-dissolve the crystals obtained by concentrating the reaction solution and then recrystallize them. Moreover, when crystallizing, the reaction solution may be simply concentrated or cooled.

Further, the obtained cyanate ester may be further narrowly dispersed. Specifically, a method can be considered in which the obtained cyanate ester is distilled to remove those having a small number of repeating units. In addition, the method of obtaining narrowly dispersed cyanate ester is not limited to this, but may include repeating reprecipitation using the difference in solubility of resins, repeating recrystallization, removing unnecessary components by recycling GPC, etc. Other methods include applying conventionally known purification methods to remove n=1 components and n≧5 components.

[Resin composition]
The resin composition of the present embodiment contains the above cyanate ester, and optionally contains a maleimide compound, a cyanate ester other than the above cyanate ester, a phenol resin, an epoxy resin, an oxetane resin, and a polymerizable unsaturated group. It may contain at least one kind selected from the group consisting of compounds having the following.

(maleimide compound)
As the maleimide compound, any known maleimide compound can be used as long as it has one or more maleimide groups in one molecule, and its type is not particularly limited. The number of maleimide groups per molecule of the maleimide compound is 1 or more, preferably 2 or more.

Examples of maleimide compounds include, but are not limited to, N-phenylmaleimide, N-hydroxyphenylmaleimide, bis(4-maleimidophenyl)methane, 2,2-bis{4-(4-maleimidophenoxy)-phenyl}propane. , bis(3,5-dimethyl-4-maleimidophenyl)methane, bis(3-ethyl-5-methyl-4-maleimidophenyl)methane, bis(3,5-diethyl-4-maleimidophenyl)methane, the following formula Examples include a maleimide compound represented by (3), a maleimide compound represented by the following formula (4), a prepolymer of these maleimide compounds, and a prepolymer of the above maleimide compound and an amine compound. One type of maleimide compound may be used alone, or two or more types may be used in combination in any combination and ratio.

(Other cyanate ester resins)
Other cyanate ester resins are not particularly limited as long as they are cyanate ester resins other than the cyanate ester represented by the above formula (1), and each molecule contains one cyanate ester group directly bonded to an aromatic ring. Any known compound can be used as appropriate as long as the compound has at least 1 or more.

Such cyanate ester resins are not particularly limited, but include, for example, naphthol aralkyl cyanate ester resins, aromatic hydrocarbon formaldehyde cyanate ester resins, and biphenylaralkyl cyanate ester resins. The cyanate ester resins may be used alone or in combination of two or more.

(phenolic resin)
Any known phenol resin can be used as long as it is a compound having two or more phenolic hydroxyl groups in one molecule, and its type is not particularly limited.

The phenolic resin is not particularly limited, but includes, for example, a cresol novolac type phenol resin, a biphenylaralkyl type phenol resin represented by the following formula (6), a naphthol aralkyl type phenol resin represented by the following formula (7), and aminotriazine. Examples include novolac type phenolic resin, naphthalene type phenolic resin, phenol novolac resin, alkylphenol novolac resin, bisphenol A type novolac resin, dicyclopentadiene type phenol resin, Zylock type phenol resin, terpene-modified phenol resin, and polyvinylphenols. The phenol resins may be used alone or in combination of two or more.

(Epoxy resin)
Any known epoxy resin can be used as long as it is a compound having one or more epoxy groups in one molecule, and its type is not particularly limited. The number of epoxy groups per molecule of the epoxy resin is 1 or more, preferably 2 or more.

The epoxy resin is not particularly limited, and conventionally known epoxy resins can be used, such as biphenylaralkyl epoxy resin, naphthalene epoxy resin, bisnaphthalene epoxy resin, polyfunctional phenol epoxy resin, and naphthylene ether type epoxy resin. Epoxy resin, phenol aralkyl epoxy resin, phenol novolak epoxy resin, cresol novolak epoxy resin, xylene novolac epoxy resin, naphthalene skeleton-modified novolac epoxy resin, dicyclopentadiene novolak epoxy resin, biphenyl novolak epoxy resin, phenol Aralkyl novolac type epoxy resin, naphthol aralkyl novolac type epoxy resin, aralkyl novolac type epoxy resin, aromatic hydrocarbon formaldehyde type epoxy resin, anthraquinone type epoxy resin, anthracene type epoxy resin, naphthol aralkyl type epoxy resin, dicyclopentadiene type epoxy resin , Zylock type epoxy resin, 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, phenol type epoxy resin, biphenyl type epoxy resin, aralkyl novolac type Compounds in which the double bonds of double bond-containing compounds such as epoxy resins, triazine skeleton epoxy resins, triglycidyl isocyanurate, alicyclic epoxy resins, polyol-type epoxy resins, glycidyl amines, glycidyl-type ester resins, and butadiene are epoxidized, and compounds obtained by reacting hydroxyl group-containing silicone resins with epichlorohydrin. One type of epoxy resin may be used alone, or two or more types may be used in combination in any combination and ratio.

(Oxetane resin)
As the oxetane resin, generally known ones can be used, and the type thereof is not particularly limited. Specific examples include alkyloxetanes such as oxetane, 2-methyloxetane, 2,2-dimethyloxetane, 3-methyloxetane, 3,3-dimethyloxetane, 3-methyl-3-methoxymethyloxetane, 3,3' -di(trifluoromethyl)perfluoroxetane, 2-chloromethyloxetane, 3,3-bis(chloromethyl)oxetane, biphenyl-type oxetane, OXT-101 (trade name manufactured by Toagosei Co., Ltd.), OXT-121 (manufactured by Toagosei Co., Ltd.) product name), etc. These oxetane resins can be used alone or in combination of two or more.

(Compound having a polymerizable unsaturated group)
As the compound having a polymerizable unsaturated group, generally known compounds can be used, and the type thereof is not particularly limited. Specific examples include vinyl compounds such as ethylene, styrene, divinylbenzene, and divinylbiphenyl; methyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and polypropylene glycol di(meth)acrylate. (meth)acrylates of monohydric or polyhydric alcohols such as acrylate, trimethylolpropane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc. ; Epoxy (meth)acrylates such as bisphenol A type epoxy (meth)acrylate and bisphenol F type epoxy (meth)acrylate; allyl chloride, allyl acetate, allyl ether, propylene, triallyl cyanurate, triallyl isocyanurate, phthalic acid Examples include allyl compounds such as diallyl, diallyl isophthalate, and diallyl maleate; benzocyclobutene resins. These compounds having a polymerizable unsaturated group can be used alone or in combination of two or more.

(hardening accelerator)
The resin composition of this embodiment may further contain a curing accelerator. Examples of the curing accelerator include, but are not limited to, imidazoles such as triphenylimidazole; benzoyl peroxide, lauroyl peroxide, acetyl peroxide, parachlorobenzoyl peroxide, di-tert-butyl-di-perphthalate, etc. organic peroxides; azo compounds such as azobisnitrile; N,N-dimethylbenzylamine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2-N-ethylanilinoethanol, tri-n-butylamine , pyridine, quinoline, N-methylmorpholine, triethanolamine, triethylenediamine, tetramethylbutanediamine, N-methylpiperidine, and other tertiary amines; phenols, xylenol, cresol, resorcinol, catechol, and other phenols; naphthenic acid Organic metal salts such as lead, lead stearate, zinc naphthenate, zinc octylate, tin oleate, dibutyltin malate, manganese naphthenate, cobalt naphthenate, iron acetylacetonate; Examples include those dissolved in compounds; inorganic metal salts such as tin chloride, zinc chloride, and aluminum chloride; organic tin compounds such as dioctyltin oxide, other alkyltins, and alkyltin oxides; Among these, triphenylimidazole is particularly preferred because it accelerates the curing reaction and tends to further improve the glass transition temperature.

(filling material)
The resin composition of this embodiment may further contain a filler. The filler is not particularly limited, but includes, for example, inorganic fillers and organic fillers. One type of filler may be used alone, or two or more types may be used in combination.

Examples of inorganic fillers include, but are not limited to, silicas such as natural silica, fused silica, synthetic silica, amorphous silica, Aerosil, and hollow silica; silicon compounds such as white carbon; titanium white, zinc oxide, magnesium oxide, Metal oxides such as zirconium oxide; nitrides such as boron nitride, agglomerated boron nitride, silicon nitride, and aluminum nitride; metal sulfides such as barium sulfate; aluminum hydroxide, heat-treated aluminum hydroxide products (heat-treated aluminum hydroxide) metal hydrates such as boehmite and magnesium hydroxide; molybdenum compounds such as molybdenum oxide and zinc molybdate; zinc compounds such as zinc borate and zinc stannate; alumina, Clay, kaolin, talc, fired clay, fired kaolin, fired talc, mica, E glass, A glass, NE glass, C glass, L glass, D glass, S glass, M glass G20, short glass fibers (E glass, T glass, D glass, S glass, Q glass, etc.), hollow glass, spherical glass, etc.

Examples of organic fillers include, but are not limited to, rubber powders such as styrene-type powder, butadiene-type powder, and acrylic-type powder; core-shell type rubber powder; silicone resin powder; silicone rubber powder; and silicone composite powder. It will be done.

[Silane coupling agent and wetting and dispersing agent]
The resin composition of this embodiment may further contain a silane coupling agent and a wetting and dispersing agent.

The silane coupling agent is not particularly limited as long as it is a silane coupling agent that is generally used for surface treatment of inorganic materials, but examples include γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ - Aminosilane compounds such as aminopropyltrimethoxysilane; Epoxysilane compounds such as γ-glycidoxypropyltrimethoxysilane; Acrylic silane compounds such as γ-acryloxypropyltrimethoxysilane; N-β-(N- Examples include cationic silane compounds such as vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride; phenylsilane compounds. The silane coupling agents may be used alone or in combination of two or more.

The wetting and dispersing agent is not particularly limited as long as it is a dispersion stabilizer used for paints, but for example, DISPER-110, 111, 118, 180, 161, BYK-W996 manufactured by Big Chemie Japan Co., Ltd. , W9010, W903, etc.

(solvent)
The resin composition of this embodiment may further contain a solvent. By including a solvent, the viscosity at the time of preparation of the resin composition is lowered, handling properties are further improved, and the impregnating property into a base material, which will be described later, tends to be further improved.

The solvent is not particularly limited as long as it can dissolve some or all of the resin components in the resin composition, but examples include ketones such as acetone and methyl ethyl ketone; aromatic hydrocarbons such as toluene and xylene. Amides such as dimethylformamide; Methyl cellosolve, propylene glycol monomethyl ether and its acetate. One type of solvent may be used alone, or two or more types may be used in combination.

[Application]
The resin composition of this embodiment can be suitably used as a cured product, prepreg, metal foil-clad laminate, laminated resin sheet, resin sheet, printed wiring board, sealing material, fiber reinforced composite material, or adhesive. can. These will be explained below.

[Cured product]
The cured product of this embodiment is obtained by curing the above resin composition. The method for producing the cured product is not particularly limited, but for example, the resin composition may be melted or dissolved in a solvent, poured into a mold, and cured under normal conditions using heat, light, etc. I can do it. In the case of thermal curing, the curing temperature is not particularly limited, but is preferably within the range of 120°C to 300°C from the viewpoint of efficient curing and prevention of deterioration of the obtained cured product. In the case of photocuring, the wavelength range of light is not particularly limited, but it is preferable to carry out curing in the range of 100 nm to 500 nm, where curing proceeds efficiently using a photopolymerization initiator or the like.

[Prepreg]
The prepreg of this embodiment includes a base material and the resin composition impregnated or applied to the base material. The prepreg manufacturing method can be carried out according to a conventional method and is not particularly limited. For example, after impregnating or coating a base material with the resin component in this embodiment, semi-curing (converting to B stage) by heating in a dryer at 100 to 200°C for 1 to 30 minutes, The prepreg of this embodiment can be produced.

The content of the resin composition (including fillers) is preferably 30 to 90% by mass, more preferably 35 to 85% by mass, and even more preferably 40 to 80% by mass, based on the total amount of prepreg. %. When the content of the resin composition is within the above range, moldability tends to be further improved.

The base material is not particularly limited, and any known material used in various printed wiring board materials can be appropriately selected and used depending on the intended use and performance. Specific examples of fibers constituting the base material include, but are not particularly limited to, glass fibers such as E glass, D glass, S glass, Q glass, spherical glass, NE glass, L glass, and T glass; Inorganic fibers other than glass: polyparaphenylene terephthalamide (Kevlar (registered trademark), manufactured by DuPont), copolyparaphenylene 3,4'oxydiphenylene terephthalamide (Technora (registered trademark), Teijin Techno Products (trademark) Fully aromatic polyamides such as 2,6-hydroxynaphthoic acid/parahydroxybenzoic acid (Vectran (registered trademark), manufactured by Kuraray Co., Ltd.), polyesters such as Zexion (registered trademark, manufactured by KB Seiren); Examples include organic fibers such as polyparaphenylenebenzoxazole (Zylon (registered trademark), manufactured by Toyobo Co., Ltd.) and polyimide. Among these, at least one selected from the group consisting of E glass cloth, T glass cloth, S glass cloth, Q glass cloth, and organic fibers is preferred. These base materials may be used alone or in combination of two or more.

The shape of the base material is not particularly limited, and examples thereof include woven fabric, nonwoven fabric, roving, chopped strand mat, and surfacing mat. The method of weaving the woven fabric is not particularly limited, but for example, plain weaving, Nanako weaving, twill weaving, etc. are known, and the weaving method can be appropriately selected from these known methods depending on the intended use and performance. . Further, glass woven fabrics subjected to fiber opening treatment or surface treated with a silane coupling agent or the like are preferably used. The thickness and mass of the base material are not particularly limited, but those having a thickness of about 0.01 to 0.3 mm are usually suitably used. In particular, from the viewpoint of strength and water absorption, the base material is preferably a woven glass fabric with a thickness of 200 μm or less and a mass of 250 g/m ² or less, and a glass woven fabric made of glass fibers of E glass, S glass, and T glass is preferable. More preferred.

[Laminated resin sheet]
The laminated resin sheet of this embodiment includes a support and the resin composition disposed on the support. A laminated resin sheet is used as a means of thinning the sheet, and can be manufactured by, for example, directly coating and drying a resin composition on a support such as a metal foil or film.

The support is not particularly limited, but known materials used for various printed wiring board materials can be used. For example, polyimide film, polyamide film, polyester film, polyethylene terephthalate (PET) film, polybutylene terephthalate (PBT) film, polypropylene (PP) film, polyethylene (PE) film, polycarbonate film, ethylenetetrafluoroethylene copolymer film, and Organic film base materials such as release films coated with a release agent on the surface of these films, conductor foils such as aluminum foil, copper foil, and gold foil, plate-like inorganic materials such as glass plates, SUS plates, and FPR. An example is film. Among these, electrolytic copper foil and PET film are preferred.

Examples of the coating method include a method in which a solution prepared by dissolving the resin composition of the present embodiment in a solvent is coated onto the support using a bar coater, a die coater, a doctor blade, a baker applicator, or the like.

The laminated resin sheet is preferably one in which the resin composition is applied to a support and then semi-cured (B-staged). Specifically, for example, after coating the resin composition on a support such as copper foil, it is semi-cured by heating for 1 to 60 minutes in a dryer at 100 to 200°C to form a laminated resin sheet. Examples include manufacturing methods. The amount of the resin composition adhered to the support is preferably in the range of 1 to 300 μm based on the resin thickness of the laminated resin sheet.

[Single layer resin sheet]
The single-layer resin sheet of this embodiment contains a resin composition. A single-layer resin sheet is formed by molding a resin composition into a sheet shape. The method for producing the resin sheet can be carried out according to a conventional method and is not particularly limited. For example, it can be obtained by peeling or etching the support from the laminated resin sheet. Note that by supplying a solution in which the resin composition of this embodiment is dissolved in a solvent into a mold having a sheet-like cavity and drying it to form it into a sheet, it is possible to form the resin composition into a sheet without using a sheet base material. A single layer resin sheet can also be obtained.

[Metal foil clad laminate]
The metal foil-clad laminate of this embodiment includes at least one prepreg laminated above, and metal foils disposed on one or both sides of the prepreg. That is, the metal foil-clad laminate of this embodiment is obtained by laminating and curing the prepreg and metal foil.

The conductor layer can be a metal foil such as copper or aluminum. The metal foil used here is not particularly limited as long as it is used for printed wiring board materials, but known copper foils such as rolled copper foil and electrolytic copper foil are preferred. Further, the thickness of the conductor layer is not particularly limited, but is preferably 1 to 70 μm, more preferably 1.5 to 35 μm.

The method and conditions for forming the metal foil-clad laminate are not particularly limited, and methods and conditions for general printed wiring board laminates and multilayer boards can be applied. For example, when molding a metal foil-clad laminate, a multistage press machine, a multistage vacuum press machine, a continuous molding machine, an autoclave molding machine, etc. can be used. Further, in forming a metal foil-clad laminate, the temperature is generally 100 to 350°C, the pressure is 2 to 100 kgf/cm ² , and the heating time is generally 0.05 to 5 hours. Furthermore, if necessary, post-curing can be performed at a temperature of 150 to 350°C. Moreover, it is also possible to form a multilayer board by laminating and molding a combination of the above-mentioned prepreg and a separately prepared inner layer wiring board.

[Printed wiring board]
The printed wiring board of this embodiment includes an insulating layer and a conductor layer formed on the surface of the insulating layer, and the insulating layer includes the resin composition. The metal foil-clad laminate described above can be suitably used as a printed wiring board by forming a predetermined wiring pattern. The metal foil-clad laminate described above has good moldability and chemical resistance, and can be particularly effectively used as a printed wiring board for semiconductor packages, which requires such performance.

Specifically, the printed wiring board of this embodiment can be manufactured, for example, by the following method. First, the above-mentioned metal foil-clad laminate (copper-clad laminate, etc.) is prepared. An inner layer circuit is formed by etching the surface of the metal foil-clad laminate to produce an inner layer substrate. The surface of the inner layer circuit of this inner layer board is subjected to surface treatment to increase adhesive strength as required, and then the required number of sheets of prepreg described above are layered on the surface of the inner layer circuit, and then metal foil for the outer layer circuit is laminated on the outside. Then heat and press to form an integral mold. In this way, a multilayer laminate is produced in which an insulating layer made of a base material and a cured resin composition is formed between the inner layer circuit and the metal foil for the outer layer circuit. Next, after drilling holes for through holes and via holes in this multilayer laminate, a desmear process is performed to remove smear, which is resin residue derived from the resin components contained in the cured material layer. . After that, a plating metal film is formed on the wall of this hole to conduct the inner layer circuit and the metal foil for the outer layer circuit, and then the metal foil for the outer layer circuit is etched to form the outer layer circuit, and the printed wiring board is manufactured. be done.

The printed wiring board obtained in the above manufacturing example has an insulating layer and a conductor layer formed on the surface of the insulating layer, and the insulating layer contains the resin composition of the present embodiment described above. That is, the prepreg described above (the base material and the resin composition attached thereto) and the resin composition layer of the metal foil-clad laminate (layer made of the resin composition described above) contain the resin composition described above. This will constitute an insulating layer.

Furthermore, when a metal foil-clad laminate is not used, a printed wiring board may be produced by forming a conductor layer to form a circuit on the prepreg, the laminated resin sheet, or the resin composition. At this time, an electroless plating method can also be used to form the conductor layer.

The printed wiring board of this embodiment can be particularly effectively used as a printed wiring board for semiconductor packages because the above-mentioned insulating layer has excellent properties in terms of plating peel strength, bending strength, dielectric constant, and thermal weight reduction rate. be able to.

[Sealing material]
The sealing material of this embodiment includes the resin composition of this embodiment. The method for producing the sealing material is not particularly limited, and any generally known method can be appropriately applied. For example, a sealing material can be produced by mixing the above-described resin composition and various known additives or solvents commonly used in sealing material applications using a known mixer. Note that the method of adding each component during mixing is not particularly limited, and generally known methods can be appropriately applied.

[Fiber-reinforced composite material]
The fiber reinforced composite material of this embodiment includes the resin composition of this embodiment and reinforcing fibers. Generally known reinforcing fibers can be used and are not particularly limited. Specific examples include glass fibers such as E glass, D glass, L glass, S glass, T glass, Q glass, UN glass, NE glass, spherical glass, carbon fiber, aramid fiber, boron fiber, PBO fiber, high Examples include strong polyethylene fibers, alumina fibers, and silicon carbide fibers. The form and arrangement of the reinforcing fibers are not particularly limited, and can be appropriately selected from woven fabrics, nonwoven fabrics, mats, knits, braided cords, unidirectional strands, rovings, chopped, etc. In addition, as a form of reinforcing fiber, a preform (a laminated fabric base fabric made of reinforcing fibers, a fabric that is sewn together with stitch thread, or a fiber structure such as a three-dimensional fabric or a braided fabric) can be applied. You can also do it.

The method for manufacturing these fiber reinforced composite materials is not particularly limited, and generally known methods can be applied as appropriate. Specific examples include a liquid composite molding method, a resin film infusion method, a filament winding method, a hand layup method, a pultrusion method, and the like. Among these, the resin transfer molding method, which is one of the liquid composite molding methods, allows materials other than preforms, such as metal plates, foam cores, and honeycomb cores, to be set in the mold in advance. Since it can be used for various purposes, it is preferably used when mass-producing composite materials with relatively complex shapes in a short period of time.

〔glue〕
The adhesive of this embodiment includes the resin composition of this embodiment. The method for producing the adhesive is not particularly limited, and any generally known method can be appropriately applied. For example, an adhesive can be manufactured by mixing the above-described resin composition and various known additives or solvents commonly used in adhesive applications using a known mixer. Note that the method of adding each component during mixing is not particularly limited, and generally known methods can be appropriately applied.

Hereinafter, the present invention will be explained in more detail using Examples and Comparative Examples. The present invention is not limited in any way by the following examples. The phenol novolaks used as raw materials in the examples were synthesized with reference to documents such as JP-A-8-57578, JP-A-2006-137928, and Patent No. 6422666.

(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 in accordance with JIS-K0070.

(Example 1) Synthesis of narrowly dispersed novolac cyanate ester 1 30.0 g of narrowly dispersed phenol novolak resin 1 (weight average molecular weight Mw 310; OH group equivalent 102 g/eq.; 0.294 mol in terms of OH group) and 22.0 g of triethylamine. 4 g (0.221 mol; 0.75 mol per 1 mol of hydroxyl group) was dissolved in 150 g of dichloromethane, and this was designated as Solution 1.

Cyanogen chloride 28.9 g (0.470 mol; 1.60 mol per 1 mol of hydroxy group), dichloromethane 67.4 g, 36% hydrochloric acid 49.1 g (0.485 mol; 1.65 mol per 1 mol of hydroxy group), water 305 g Solution 1 was poured into the solution over 11 minutes while stirring and keeping the liquid temperature at -6 to -2°C. After pouring solution 1, stir at the same temperature for 5 minutes, and then dissolve 37.2 g of triethylamine (0.368 mol; 1.25 mol per 1 mol of hydroxyl group) in 37.2 g of dichloromethane (solution 2). was injected over 11 minutes. After pouring the second solution, the mixture was stirred at the same temperature for 30 minutes to complete the reaction.

Thereafter, the reaction solution was allowed to stand still to separate the organic phase and the aqueous phase. The obtained organic phase was washed twice with 150 mL of 0.1N hydrochloric acid and then six times with 150 mL of water. The electrical conductivity of the wastewater after the sixth washing with water was 8 μS/cm, confirming that the ionic compounds to 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 70° C. for 1 hour to obtain 36.2 g of the target narrowly dispersed novolac cyanate ester 1 (pale yellow viscous material). The weight average molecular weight Mw of the obtained narrowly dispersed novolac cyanate ester 1 was 409. Further, the IR spectrum of the narrowly dispersed novolac type cyanate ester 1 showed absorption at 2235 m ^-1 and 2261 cm ^-1 (cyanate ester group), and no absorption at hydroxyl group.

(Example 2) Synthesis of narrowly dispersed novolac cyanate ester 2 30.0 g of narrowly dispersed phenol novolak resin (weight average molecular weight Mw 338; OH group equivalent 106 g/eq.; 0.283 mol in terms of OH group) and 21.5 g of triethylamine (0.212 mol; 0.75 mol per 1 mol of hydroxy group) was dissolved in 150 g of dichloromethane, and this was used as Solution 3.

Cyanogen chloride 27.8 g (0.452 mol; 1.60 mol per 1 mol of hydroxy group), dichloromethane 64.9 g, 36% hydrochloric acid 47.3 g (0.467 mol; 1.65 mol per 1 mol of hydroxy group), water 293 g Solution 3 was poured into the solution over 11 minutes while stirring and keeping the liquid temperature at -7 to -4°C. After pouring solution 3, stir at the same temperature for 5 minutes, and then dissolve 35.8 g of triethylamine (0.354 mol; 1.25 mol per 1 mol of hydroxyl group) in 35.8 g of dichloromethane (solution 4). was injected over 11 minutes. After pouring the solution 4, the mixture was stirred at the same temperature for 30 minutes to complete the reaction.

Thereafter, the reaction solution was allowed to stand still to separate the organic phase and the aqueous phase. The obtained organic phase was washed twice with 150 mL of 0.1N hydrochloric acid and then six times with 150 mL of water. The electrical conductivity of the wastewater after the sixth washing with water was 9 μS/cm, confirming that the ionic compounds to 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 70° C. for 1 hour to obtain 36.0 g of the target narrowly dispersed novolac cyanate ester 2 (pale yellow viscous material). The weight average molecular weight Mw of the obtained narrowly dispersed novolac cyanate ester 2 was 442. Further, the IR spectrum of the narrowly dispersed novolak cyanate ester 2 showed absorption at 2234 cm ^-1 and 2261 cm ^-1 (cyanate ester group), and no absorption at hydroxyl group.

(Comparative Example 1) Synthesis of general-purpose novolac type cyanate ester 1 30.0 g of general-purpose phenol novolac resin (weight average molecular weight Mw 493; OH group equivalent 105 g/eq.; 0.286 mol in terms of OH group) and triethylamine 21.8 g (0 .215 mol; 0.75 mol per mol of hydroxy group) was dissolved in 150 g of dichloromethane, and this was designated as Solution 5.

Cyanogen chloride 28.1 g (0.457 mol; 1.60 mol per 1 mol of hydroxy group), dichloromethane 65.6 g, 36% hydrochloric acid 47.7 g (0.471 mol; 1.65 mol per 1 mol of hydroxy group), water 296 g Solution 5 was poured into the solution over 11 minutes while stirring and keeping the liquid temperature at -6 to -3°C. After pouring solution 5, stir at the same temperature for 5 minutes, and then dissolve 39.1 g of triethylamine (0.386 mol; 1.35 mol per 1 mol of hydroxyl group) in 39.1 g of dichloromethane (solution 6). was injected over 11 minutes. After pouring 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 still to separate the organic phase and the aqueous phase. The obtained organic phase was washed twice with 150 mL of 0.1N hydrochloric acid and then six times with 150 mL of water. The electrical conductivity of the wastewater after the sixth washing with water was 10 μS/cm, confirming that the ionic compounds to 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 70° C. for 1 hour to obtain 36.0 g of the desired general-purpose novolak cyanate ester 1 (pale yellow viscous material). The weight average molecular weight Mw of the obtained general-purpose novolac type cyanate ester 1 was 848. Further, the IR spectrum of the general-purpose novolac type cyanate ester 1 showed absorption at 2234 cm ^-1 and 2261 cm ^-1 (cyanate ester group), and no absorption at hydroxyl group.

(Comparative Example 2) Synthesis of general-purpose novolac cyanate ester 2 25.0 g of general-purpose phenol novolac resin (weight average molecular weight Mw 480; OH group equivalent 105 g/eq.; 0.238 mol in terms of OH group) and triethylamine 24.1 g (0 .238 mol; 1.0 mol per 1 mol of hydroxy group) was dissolved in 150 g of dichloromethane, and this was designated as Solution 7.

Cyanogen chloride 23.4 g (0.381 mol; 1.60 mol per mol of hydroxy group), dichloromethane 54.6 g, 36% hydrochloric acid 39.8 g (0.393 mol; 1.65 mol per mol of hydroxy group), water 282 g Solution 7 was poured into the solution over 10 minutes while stirring and keeping the liquid temperature at -6 to -1°C. After pouring solution 7, stir at the same temperature for 5 minutes, and then dissolve 21.7 g of triethylamine (0.214 mol; 0.90 mol per 1 mol of hydroxy group) in 21.7 g of dichloromethane (solution 8). was poured over 8 minutes. After pouring the solution 8, the mixture was stirred at the same temperature for 30 minutes to complete the reaction.

Thereafter, the reaction solution was allowed to stand still to separate the organic phase and the aqueous phase. The obtained organic phase was washed twice with 150 mL of 0.1N hydrochloric acid and then six times with 150 mL of water. The electrical conductivity of the wastewater after the sixth washing with water was 14 μS/cm, confirming that the ionic compounds to 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 70° C. for 1 hour to obtain 30.0 g of the desired general-purpose novolak cyanate ester 2 (pale yellow viscous material). The weight average molecular weight Mw of the obtained general-purpose novolac type cyanate ester 2 was 763. Further, the IR spectrum of the general-purpose novolac type cyanate ester 2 showed absorption at 2234 cm ^-1 and 2262 cm ^-1 (cyanate ester group), and no absorption at hydroxyl group.

[Measurement of area ratio, weight average molecular weight (Mw), number average molecular weight (Mn), and degree of dispersion (Mw/Mn) of n component]
From the chromatogram obtained by gel permeation chromatography (GPC) analysis, the area of the entire chromatogram and the peak area of each n component of the cyanate esters obtained in Examples and Comparative Examples were calculated. In addition, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the entire chromatogram of the cyanate esters obtained in Examples and Comparative Examples were determined, and the degree of dispersion (Mw/Mn) was determined. The measurement conditions are shown below.

(Measurement condition)
Device: LaChromElite (manufactured by Hitachi High-Technologies Corporation)
Column: TSKgel GMHHR-M×2 (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Flow rate: 1mL/min
Temperature: 40℃
Detector: RI
Standard material: polystyrene standard

〔viscosity〕
Using a dynamic viscoelasticity measuring device (Discovery HR-2 manufactured by TA Instruments Co., Ltd.), the cyanate esters obtained in the Examples and Comparative Examples were measured at 40°C and 80°C. The viscosity was measured.

[Weight reduction rate (%)]
Using a differential thermogravimetric simultaneous measurement device (TG/DTA6200 manufactured by SII Nanotechnology Co., Ltd.), the cyanate esters obtained in the Examples and Comparative Examples were heated at a starting temperature of 40°C under a nitrogen atmosphere. The weight loss rate was calculated based on the following formula by measuring the weight after increasing the temperature to 150° C. at a rate of 10° C./min and maintaining the same temperature for 30 minutes.
Weight reduction rate (%) = (I-J)/I x 100
I represents the weight at the starting temperature, and J represents the weight after being held at 150° C. for 30 minutes.

As shown in Table 1, the cyanate ester of the example has a higher ratio of n=2 to 4 components than the cyanate ester of the comparative example, and the degree of dispersion is also lower, confirming that the cyanate ester is narrowly dispersed. . Furthermore, it can be seen that the cyanate esters of Examples have lower viscosities at 40°C and 80°C than the cyanate esters of Comparative Examples, and the weight loss rate is also the same or lower.

[Preliminary polymerization test]
In addition to the above evaluation, a preliminary polymerization test using the cyanate esters of Example 1 and Comparative Example 1 was conducted. In the preliminary polymerization test, 50 g of each of the cyanate esters of Example 1 and Comparative Example 1 were charged into a 100 mL three-necked flask equipped with a stirring bar, heated to 150°C, and reacted for a predetermined period of time with stirring. A polymer was obtained. The viscosity of the obtained prepolymerized product at 125° C. was measured over time to confirm the progress rate of polymerization. FIG. 1 shows a diagram in which the progress of polymerization is plotted, with the horizontal axis representing time and the vertical axis representing log (viscosity at time of measurement η/initial viscosity η ₀ ).

As shown in FIG. 1, it was found that when the cyanate ester of Example 1 was used, polymerization proceeded at a constant viscosity increase rate. On the other hand, when the cyanate ester of Comparative Example 1 was used, the rate of increase in viscosity increased over time, and it was found that the rate of increase in viscosity was not constant. The reason for this is that the cyanate ester of Comparative Example 1 has a wide dispersion and contains a large amount of high n components, so high molecular weight substances are rapidly generated from the middle, whereas the cyanate ester of Example 1 has a narrow dispersion and contains a large amount of high n components. This is thought to be because the presence of a small amount of high-n components leads to multimerization in a relatively orderly manner. However, the reasons are not limited to the above.

The cyanate ester of the present invention has industrial applicability as a material for prepregs, sealing materials, fiber-reinforced composite materials, adhesives, and the like.

Claims (14)

It has a structure represented by the following formula (1), and the total content of n = 2 to 4 components is 80 area % or more in area % measured by gel permeation chromatography.
cyanate ester.
(In formula (1), n represents the number of repeating units. R each independently represents a hydrogen atom or a methyl group.) In area % measured by gel permeation chromatography, the content of n≧5 components is 15 area % or less,
The cyanate ester according to claim 1. In area % measured by gel permeation chromatography, the content of n = 1 component is 12 area % or less,
Cyanate ester according to claim 1 or 2. The weight average molecular weight (Mw) in terms of polystyrene is 300 or more and 700 or less,
Cyanate ester according to any one of claims 1 to 3. The dispersion ratio (Mw/Mn) between weight average molecular weight (Мw) and number average molecular weight (Mn) in terms of polystyrene is 1 or more and 1.5 or less,
Cyanate ester according to any one of claims 1 to 4. R is a hydrogen atom,
Cyanate ester according to any one of claims 1 to 5. Containing the cyanate ester according to any one of claims 1 to 6,
Resin composition. Furthermore, containing a maleimide compound,
The resin composition according to claim 7. Furthermore, it contains at least one selected from the group consisting of a cyanate ester resin other than the cyanate ester, a phenol resin, an epoxy resin, an oxetane resin, and a compound having a polymerizable unsaturated group.
The resin composition according to claim 7 or 8. A resin composition obtained by curing the resin composition according to any one of claims 7 to 9.
cured product. base material and
The resin composition according to any one of claims 7 to 9, impregnated or applied to the base material,
has,
prepreg. comprising the resin composition according to any one of claims 7 to 9.
Encapsulation material. comprising the resin composition according to any one of claims 7 to 9 and reinforcing fibers,
Fiber reinforced composite material. comprising the resin composition according to any one of claims 7 to 9.
glue.