JP2020147735A - Curable composition, dry film, cured product, laminate and electronic component - Google Patents

Abstract

To provide a curable composition that maintains low dielectric properties and yet is soluble in various solvents, and is cured to give a film that has excellent heat resistance, elongation, and strength.SOLUTION: A curable composition contains a polyphenylene ether composed of a raw material phenol containing a phenol satisfying at least Condition 1, and a cyanate ester resin. (Condition 1) It has hydrogen atoms at an ortho position and a para position.SELECTED DRAWING: None

Description

The present invention relates to curable compositions containing polyphenylene ethers, dry films, prepregs, cured products, laminates, and electronic components.

With the widespread use of large-capacity high-speed communications represented by the 5th generation communication system (5G) and millimeter-wave radars for ADAS (advanced driver assistance systems) of automobiles, the frequency of signals of communication equipment has been increasing.

However, when a conventional epoxy resin or the like is used as the wiring board material, the relative permittivity (Dk) and the dielectric loss tangent (Df) are not sufficiently low, so that the higher the frequency, the larger the transmission loss due to the dielectric loss occurs. Problems such as signal attenuation and heat generation have occurred. Therefore, polyphenylene ether having excellent low dielectric properties has been used, but since polyphenylene ether is a thermoplastic resin, there is a problem of heat resistance.

As a means for solving this problem, Non-Patent Document 1 proposes that an allyl group is introduced into the molecule of polyphenylene ether to obtain a thermosetting resin.

J. Nunoshige, H. Akahoshi, Y. Shibasaki, M. Ueda, J. Polym. Sci. Part A: Polym. Chem. 2008, 46, 5278-3223.

However, the solvent in which the polyphenylene ether is soluble is limited, and the polyphenylene ether obtained by the method of Non-Patent Document 1 is also soluble only in a highly toxic solvent such as chloroform and toluene. Therefore, there is a problem that it is difficult to handle the resin varnish and control the solvent exposure in the process of forming a coating film and curing it, such as for wiring board applications.

Furthermore, the insulating film for electronic components has excellent heat resistance from the viewpoint of use as an electronic material, excellent elongation characteristics from the viewpoint of ease of handling as a film and prevention of cracks, coreless substrate and the substrate itself. It is required to have excellent strength from the viewpoint of lightness, thinness, shortness and miniaturization.

Therefore, an object of the present invention is that a film obtained by curing is excellent because it is soluble in various solvents (organic solvents other than highly toxic organic solvents such as cyclohexanone) while maintaining low dielectric properties. An object of the present invention is to provide a curable composition having heat resistance, elongation characteristics, and strength.

As a result of diligent studies toward the realization of the above object, the present inventors have solved the above problems by using a curable composition containing a polyphenylene ether made from a specific phenol as a raw material and a cyanate ester resin. We have found what is possible and have completed the present invention.

That is, the present invention
Polyphenylene ether composed of raw material phenols including phenols satisfying at least condition 1 and
Cyanate ester resin and
Provided is a curable composition characterized by containing.
(Condition 1)
Has hydrogen atoms at the ortho and para positions

The present invention preferably
Polyphenylene ether, which consists of raw material phenols including phenols that satisfy at least condition 1, and has a slope of less than 0.6 calculated by the conformation plot.
Cyanate ester resin and
To provide a curable composition characterized by containing.
(Condition 1)
Has hydrogen atoms at the ortho and para positions

Part or all of the polyphenylene ether
Phenols (A) that satisfy at least both the following condition 1 and the following condition 2, or phenols (B) that satisfy at least the following condition 1 and do not satisfy the following condition 2 and phenols that do not satisfy the following condition 1 and satisfy the following condition 2 It may be a polyphenylene ether composed of raw material phenols containing a mixture of class (C).
(Condition 1)
It has hydrogen atoms at the ortho and para positions (Condition 2)
It has a hydrogen atom at the para position and has a functional group containing an unsaturated carbon bond.

The present invention also provides a dry film or prepreg, which is obtained by applying the curable composition to a substrate.

The present invention also provides a cured product obtained by curing the curable composition.

The present invention also provides a laminated board containing the cured product.

The present invention also provides an electronic component characterized by having the cured product.

According to the present invention, a film obtained by curing is excellent because it is soluble in various solvents (organic solvents other than highly toxic organic solvents such as cyclohexanone) while maintaining low dielectric properties. It is possible to provide a curable composition having heat resistance, elongation characteristics, strength and the like.

All statements of Japanese Patent Application No. 2018-13433338 are cited by reference and incorporated herein by reference.

When isomers are present in the described compounds, all possible isomers can be used in the present invention unless otherwise specified.

Further, in the present invention, "unsaturated carbon bond" indicates an ethylenic or acetylene carbon-carbon multiple bond (double bond or triple bond) unless otherwise specified.

In the present invention, when the raw material phenols are described as "ortho-position", "para-position", etc., the position of the phenolic hydroxyl group is used as a reference (ipso-position) unless otherwise specified.

In the present invention, when simply expressed as "ortho position" or the like, it means "at least one of the ortho positions" or the like. Therefore, unless there is a particular contradiction, the term "ortho position" may be interpreted as indicating either one of the ortho positions or both of the ortho positions.

In the present invention, phenols used as a raw material for polyphenylene ether (PPE) and which can be a constituent unit of polyphenylene ether are collectively referred to as "raw material phenols".

Hereinafter, the curable composition of the present invention (also simply referred to as a composition) will be described.

(Polyphenylene ether)
The curable composition of the present invention contains a predetermined polyphenylene ether. As will be described later, the predetermined polyphenylene ether is a polyphenylene ether having a branched structure. Therefore, a predetermined polyphenylene ether may be expressed as a branched polyphenylene ether.

The predetermined polyphenylene ether is obtained by oxidative polymerization of raw material phenols containing phenols satisfying the following condition 1 as an essential component.
(Condition 1)
It has hydrogen atoms at the ortho and para positions.

Since phenols satisfying condition 1 {for example, phenols (A) and phenols (B) described later} have hydrogen atoms at the ortho position, only the ipso position and the para position are oxidatively polymerized with the phenols. In addition, since an ether bond can be formed even at the ortho position, it is possible to form a branched chain-like structure.

Phenols that do not satisfy condition 1 {for example, phenols (C) and phenols (D) described later} are linearly formed by forming ether bonds at the ipso and para positions when oxidatively polymerized. It will be polymerized.

As described above, a part of the structure of the predetermined polyphenylene ether is branched by the benzene ring in which at least three positions of the ipso position, the ortho position and the para position are ether-bonded. The polyphenylene ether is considered to be, for example, a compound which is a polyphenylene ether having a branched structure as represented by the formula (i) in the skeleton.

In formula (i), R _{a to} R _k are hydrogen atoms or hydrocarbon groups having 1 to 15 carbon atoms (preferably 1 to 12 carbon atoms).

The raw material phenols may contain other phenols that do not satisfy the condition 1 as long as the effects of the present invention are not impaired.

Examples of other phenols include phenols (C) and phenols (D) described later, and phenols having no hydrogen atom at the para position. In order to increase the molecular weight of the polyphenylene ether, it is preferable to further contain phenols (C) and phenols (D) as raw material phenols.

Particularly preferable predetermined polyphenylene ethers are phenols (A) that satisfy at least both the following condition 1 and the following condition 2, or phenols (B) that satisfy at least the following condition 1 and do not satisfy the following condition 2 and the following condition 1. It is a polyphenylene ether composed of raw material phenols containing a mixture of phenols (C) satisfying the following condition 2. As described below, preferred predetermined polyphenylene ethers have unsaturated carbon bonds in their side chains. When cured, this unsaturated carbon bond allows for three-dimensional cross-linking. As a result, it is extremely excellent in heat resistance and solvent resistance.

Specifically, the predetermined polyphenylene ether is
(Form 1) Phenols that satisfy at least both the following condition 1 and the following condition 2 (A) Raw material phenols contained as essential components, or
(Form 2) Raw material phenols containing at least a mixture of phenols (B) that satisfy the following condition 1 and not satisfying the following condition 2 and phenols (C) that do not satisfy the following condition 1 and satisfy the following condition 2 as essential components. ,
Is obtained by oxidative polymerization.
(Condition 1)
It has hydrogen atoms at the ortho and para positions (Condition 2)
It has a hydrogen atom at the para position and has a functional group containing an unsaturated carbon bond.

Phenols that satisfy condition 2 {for example, phenols (A) and phenols (C)} have a hydrocarbon group containing at least an unsaturated carbon bond. Therefore, the polyphenylene ether synthesized from phenols satisfying condition 2 as a raw material has crosslinkability by having a hydrocarbon group containing an unsaturated carbon bond as a functional group.

As described above, a part of the structure of the preferable predetermined polyphenylene ether is branched by the benzene ring in which at least three positions of the ipso position, the ortho position and the para position are ether-bonded. The polyphenylene ether is, for example, a polyphenylene ether having a branched structure represented by at least the formula (i) in the skeleton, and is considered to be a compound having a hydrocarbon group containing at least one unsaturated carbon bond as a functional group. That is, at least one of R _{a to} R _{k in} the above formula (i) is a hydrocarbon group having an unsaturated carbon bond.

Next, the above-mentioned form 1 may be a form containing phenols (B) and / or phenols (C) as raw material phenols. Further, the above-mentioned form 2 may further contain phenols (A) as raw material phenols.

In addition, the raw material phenols may contain other phenols as long as the effects of the present invention are not impaired.

Examples of other phenols include phenols (D), which are phenols having a hydrogen atom at the para position, no hydrogen atom at the ortho position, and no functional group containing an unsaturated carbon bond. Be done.

In both the first and second forms, it is preferable to further contain phenols (D) as raw material phenols in order to increase the molecular weight of the polyphenylene ether.

In the above form 2, the polyphenylene ether is most preferably in a form further containing the phenols (D) as the raw material phenols.

Further, in the above form 2, from the viewpoint of industrial and economic viewpoints, the phenols (B) are at least one of o-cresol, 2-phenylphenol, 2-dodecylphenol and phenol, and the phenols. It is preferable that (C) is 2-allyl-6-methylphenol.

Hereinafter, the phenols (A) to (D) will be described in more detail.

As described above, the phenols (A) are phenols that satisfy both conditions 1 and 2, that is, phenols having hydrogen atoms at the ortho and para positions and having a functional group containing an unsaturated carbon bond. It is preferably the phenols (a) represented by the following formula (1).

In the formula (1), R _{1 to} R ₃ are hydrogen atoms or hydrocarbon groups having 1 to 15 carbon atoms. However, at least one of R _{1 to} R ₃ is a hydrocarbon group having an unsaturated carbon bond. The hydrocarbon group preferably has 1 to 12 carbon atoms from the viewpoint of facilitating polymerization during oxidative polymerization.

Examples of the phenols (a) represented by the formula (1) include o-vinylphenol, m-vinylphenol, o-allylphenol, m-allylphenol, 3-vinyl-6-methylphenol, and 3-vinyl-6-. Ethylphenol, 3-vinyl-5-methylphenol, 3-vinyl-5-ethylphenol, 3-allyl-6-methylphenol, 3-allyl-6-ethylphenol, 3-allyl-5-methylphenol, 3- Examples thereof include allyl-5-ethylphenol. As the phenols represented by the formula (1), only one kind may be used, or two or more kinds may be used.

As described above, the phenols (B) have a hydrogen atom at the ortho-position and a para-position and do not have a functional group containing an unsaturated carbon bond, that is, a phenol that satisfies condition 1 and does not satisfy condition 2. It is a phenol, preferably a phenol (b) represented by the following formula (2).

In the formula (2), R _{4 to} R ₆ are hydrogen atoms or hydrocarbon groups having 1 to 15 carbon atoms. However, R _{4 to} R ₆ do not have unsaturated carbon bonds. The hydrocarbon group preferably has 1 to 12 carbon atoms from the viewpoint of facilitating polymerization during oxidative polymerization.

Examples of the phenols (b) represented by the formula (2) include phenol, o-cresol, m-cresol, o-ethylphenol, m-ethylphenol, 2,3-xylenol, 2,5-xylenol, 3,5. Examples thereof include -xylenol, o-tert-butylphenol, m-tert-butylphenol, o-phenylphenol, m-phenylphenol, 2-dodecylphenol, and the like. As the phenols represented by the formula (2), only one kind may be used, or two or more kinds may be used.

As described above, the phenols (C) are phenols that do not satisfy condition 1 and satisfy condition 2, that is, they have a hydrogen atom at the para position, do not have a hydrogen atom at the ortho position, and have an unsaturated carbon bond. It is a phenol having a functional group containing, and is preferably a phenol (c) represented by the following formula (3).

In the formula (3), R ₇ and R ₁₀ are hydrocarbon groups having 1 to 15 carbon atoms, and R ₈ and R ₉ are hydrogen atoms or hydrocarbon groups having 1 to 15 carbon atoms. However, at least one of R _{7 to} R ₁₀ is a hydrocarbon group having an unsaturated carbon bond. The hydrocarbon group preferably has 1 to 12 carbon atoms from the viewpoint of facilitating polymerization during oxidative polymerization.

Examples of the phenols (c) represented by the formula (3) include 2-allyl-6-methylphenol, 2-allyl-6-ethylphenol, 2-allyl-6-phenylphenol, and 2-allyl-6-styrylphenol. , 2,6-divinylphenol, 2,6-diallylphenol, 2,6-diisopropenylphenol, 2,6-dibutenylphenol, 2,6-diisobutenylphenol, 2,6-diisopentenylphenol, 2, Examples thereof include -methyl-6-styrylphenol, 2-vinyl-6-methylphenol, 2-vinyl-6-ethylphenol and the like. As the phenols represented by the formula (3), only one kind may be used, or two or more kinds may be used.

As described above, the phenols (D) are phenols having a hydrogen atom at the para position, no hydrogen atom at the ortho position, and no functional group containing an unsaturated carbon bond, preferably the following. It is a phenol (d) represented by the formula (4).

In formula (4), R ₁₁ and R ₁₄ are hydrocarbon groups having 1 to 15 carbon atoms having no unsaturated carbon bond, and R ₁₂ and R ₁₃ have no hydrogen atom or unsaturated carbon bond. It is a hydrocarbon group having 1 to 15 carbon atoms. The hydrocarbon group preferably has 1 to 12 carbon atoms from the viewpoint of facilitating polymerization during oxidative polymerization.

Examples of the phenols (d) represented by the formula (4) include 2,6-dimethylphenol, 2,3,6-trimethylphenol, 2-methyl-6-ethylphenol, and 2-ethyl-6-n-propylphenol. , 2-Methyl-6-n-butylphenol, 2-methyl-6-phenylphenol, 2,6-diphenylphenol, 2,6-ditolylphenol and the like can be exemplified. As the phenols represented by the formula (4), only one kind may be used, or two or more kinds may be used.

Here, in the present invention, examples of the hydrocarbon group include an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group and an alkynyl group, and an alkyl group, an aryl group and an alkenyl group are preferable. Examples of the hydrocarbon group having an unsaturated carbon bond include an alkenyl group and an alkynyl group. In addition, these hydrocarbon groups may be linear or branched chain.

Further, as other phenols, phenols and the like having no hydrogen atom at the para position may be contained.

The ratio of phenols satisfying condition 1 to the total amount of raw material phenols is preferably 1 to 50 mol%.

It is not necessary to use phenols satisfying condition 2, but when they are used, the ratio of phenols satisfying condition 2 to the total amount of raw material phenols is preferably 0.5 to 99 mol%, preferably 1 to 99 mol%. Is more preferable.

The polyphenylene ether obtained by oxidatively polymerizing the raw material phenols as described above by a known and commonly used method preferably has a number average molecular weight of 8,000 to 100,000. In the case of the predetermined polyphenylene ether of the present invention, the polymer polyphenylene ether can be mixed with the cyanate ester, and a cured film having improved various performances can be obtained. The number average molecular weight may be 2,000 to 30,000. It is more preferably 5,000 to 30,000, further preferably 8,000 to 30,000, and particularly preferably 8,000 to 25,000. Further, the polyphenylene ether preferably has a polydispersity index (PDI: weight average molecular weight / number average molecular weight) of 1.5 to 20.

In the present invention, the number average molecular weight and the weight average molecular weight are measured by gel permeation chromatography (GPC) and converted by a calibration curve prepared using standard polystyrene.

1 g of the given polyphenylene ether is soluble at 25 ° C., preferably with respect to 100 g of cyclohexanone (more preferably with respect to 100 g of cyclohexanone, DMF and PMA). The fact that 1 g of polyphenylene ether is soluble in 100 g of a solvent (for example, cyclohexanone) means that when 1 g of polyphenylene ether and 100 g of solvent are mixed, turbidity and precipitation cannot be visually confirmed. It is more preferable that the predetermined polyphenylene ether is soluble in 1 g or more with respect to 100 g of cyclohexanone at 25 ° C.

The predetermined polyphenylene ether can be produced by applying conventionally known methods for synthesizing polyphenylene ether (polymerization conditions, presence / absence of catalyst, type of catalyst, etc.) except that specific ones are used as raw material phenols. is there.

The content of the predetermined polyphenylene ether is the balance excluding other components described later. Although it depends on the content of these other components, it is typically 5 to 30% by mass or 10 to 20% by mass based on the total solid content of the composition.

The solid content of the composition means a component other than the solvent (particularly an organic solvent), or the mass or volume thereof.

Since the predetermined polyphenylene ether has a branched structure, the solubility in various solvents and the compatibility with other components of the composition are improved. Therefore, each component of the composition is uniformly dissolved or dispersed, and a uniform cured product can be obtained. As a result, this cured product is extremely excellent in heat resistance, tensile strength, and solvent resistance. In particular, preferred predetermined polyphenylene ethers (branched polyphenylene ethers containing unsaturated carbon bonds) can be crosslinked with each other or with other components containing unsaturated carbon bonds. As a result, the heat resistance and the like of the obtained cured product become better.

Here, the branched structure (degree of branching) of the polyphenylene ether can be confirmed based on the following analysis procedure.

<Analysis procedure>
After preparing a chloroform solution of polyphenylene ether at intervals of 0.1, 0.15, 0.2, 0.25 mg / mL, create a graph of refractive index difference and concentration while sending the solution at 0.5 mL / min. , The index of refractive index increment dn / dc is calculated from the slope. Next, the absolute molecular weight is measured under the following device operating conditions. With reference to the chromatogram of the RI detector and the chromatogram of the MALS detector, the regression line by the least squares method is obtained from the logarithmic graph (conformation plot) of the molecular weight and the radius of gyration, and the slope is calculated.

<Measurement conditions>
Device name: HLC8320GPC
Mobile phase: Chloroform column: TOSOH TSKquadcolumn HHR-H
+ TSKgelGMHHR-H (2)
+ TSKgelG2500HHR
Flow velocity: 0.6 mL / min.
Detector: DAWN HELEOS (MALS detector)
+ Optilab rEX (RI detector, wavelength 254 nm)
Sample concentration: 0.5 mg / mL
Sample solvent: Same as mobile phase. Dissolve 5 mg of sample in 10 mL of mobile phase Injection volume: 200 μL
Filter: 0.45 μm
STD Reagent: Standard Polystyrene Mw 37,900
STD concentration: 1.5 mg / mL
STD solvent: Same as mobile phase. Dissolve 15 mg of sample in 10 mL of mobile phase Analysis time: 100 min

In resins having the same absolute molecular weight, the distance (radius of rotation) from the center of gravity to each segment becomes smaller as the polymer chain branches more. Therefore, the slope of the logarithmic plot of the absolute molecular weight and the radius of gyration obtained by GPC-MALS indicates the degree of branching, and the smaller the slope, the more the branching progresses. In the present invention, the smaller the slope calculated in the conformation plot, the more polyphenylene ether branches, and the larger the slope, the less polyphenylene ether branches.

In the polyphenylene ether, the inclination is, for example, less than 0.6, preferably 0.55 or less, 0.50 or less, 0.45 or less, or 0.40 or less. When the above slope is in this range, it is considered that the polyphenylene ether has sufficient branching. The lower limit of the inclination is not particularly limited, but is, for example, 0.05 or more, 0.10 or more, 0.15 or more, or 0.20 or more.

The slope of the conformation plot can be adjusted by changing the temperature, the amount of catalyst, the stirring speed, the reaction time, the amount of oxygen supplied, and the amount of solvent in the synthesis of polyphenylene ether. More specifically, by increasing the temperature, increasing the amount of catalyst, increasing the stirring speed, increasing the reaction time, increasing the amount of oxygen supply, and / or decreasing the amount of solvent, the inclination of the conformation plot is increased. It tends to be low (polyphenylene ether is more likely to branch).

The polyphenylene ether may be a terminally modified polyphenylene ether. That is, some or all of the terminal hydroxyl groups in the polyphenylene ether can be modified by a conventionally known method using a modification compound. The type of denaturing compound, reaction temperature, reaction time, presence / absence of catalyst, type of catalyst, etc. can be appropriately designed. Two or more kinds of compounds may be used as a modification compound.

Here, the modification compound may be any compound capable of modifying the terminal hydroxyl group, and specifically, an organic compound having 1 or more carbon atoms that can react with a phenolic hydroxyl group in the presence or absence of a catalyst. Examples include compounds. Such an organic compound may contain an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a halogen atom and the like.

When the terminal hydroxyl group is modified with the modification compound, an ether bond or an ester bond is usually formed between the terminal hydroxyl group and the modification compound.

It is also possible to impart properties derived from the modification compound to the terminally modified polyphenylene ether. For example, when the modification compound contains a phosphorus atom (more specifically, the modification compound is a halogenated organic phosphorus compound), the flame retardancy of the cured product can be improved. Further, from the viewpoint of heat resistance of the cured product, the modifying compound preferably contains a heat- or photoreactive functional group. For example, when the modifying compound contains an unsaturated carbon bond, a cyanate group or an epoxy group, the reactivity of the terminal modified polyphenylene ether of the present invention can be improved.

Preferable examples of the modification compound include an organic compound represented by the following formula (A).

Wherein _{(A), R A, R} B, R C are each independently hydrogen or a hydrocarbon group having 1 to 9 carbon atoms, _{R D} is a hydrocarbon group having 1 to 9 carbon atoms Yes, X is a group capable of reacting with phenolic hydroxyl groups such as F, Cl, Br, I or CN.

The modification of the terminal hydroxyl group of the polyphenylene ether can be confirmed by comparing the hydroxyl values of the polyphenylene ether and the terminal-modified polyphenylene ether. The terminal-modified polyphenylene ether may remain partially unmodified hydroxyl groups.

(Cyanate ester resin)
The curable composition of the present invention contains a cyanate ester resin. By using the predetermined polyphenylene ether of the present invention in combination with the cyanate ester resin, it is possible to form a cured film having excellent heat resistance and elongation characteristics while maintaining low dielectric properties.

Cyanate ester resin is a compound having two or more cyanate ester groups (-OCN) in one molecule.

As the cyanate ester resin, any conventionally known resin can be used. Examples of the cyanate ester resin include phenol novolac type cyanate ester resin, alkylphenol novolac type cyanate ester resin, dicyclopentadiene type cyanate ester resin, bisphenol A type cyanate ester resin, bisphenol F type cyanate ester resin, and bisphenol M type cyanate ester resin. , Bisphenol S type cyanate ester resin. Further, it may be a prepolymer in which a part is triazine-ized.

Such cyanate ester resin may be any of a monomer, an oligomer, and a polymer.

The cyanate ester resin may be used alone or in combination of two or more.

The content of the cyanate ester resin is, for example, a predetermined polyphenylene ether: cyanate ester resin = 1: 99 to 99: 1, preferably 10:90 to 90:10, in terms of mass ratio.

(silica)
The curable composition of the present invention may contain silica. When the composition contains silica, the film-forming property of the composition can be improved. Furthermore, flame retardancy can be imparted to the obtained cured product.

The average particle size of silica is preferably 0.02 to 10 μm, more preferably 0.02 to 3 μm. Here, the average particle size can be obtained as the median diameter (d50, volume standard) based on the cumulative distribution from the measured value of the particle size distribution by the laser diffraction / scattering method using a commercially available laser diffraction / scattering type particle size distribution measuring device. it can.

It is also possible to use silicas having different average particle sizes together. From the viewpoint of increasing the filling of silica, for example, nano-order fine silica having an average particle size of less than 1 μm may be used in combination with silica having an average particle size of 1 μm or more.

The silica may be surface-treated with a coupling agent. By treating the surface with a silane coupling agent, the dispersibility with polyphenylene ether can be improved. Moreover, the affinity with an organic solvent can be improved.

As the silane coupling agent, for example, an epoxysilane coupling agent, a mercaptosilane coupling agent, a vinylsilane coupling agent, or the like can be used. As the epoxysilane coupling agent, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane and the like can be used. As the mercaptosilane coupling agent, for example, γ-mercaptopropyltriethoxysilane or the like can be used. As the vinylsilane coupling agent, for example, vinyltriethoxysilane or the like can be used.

The amount of the silane coupling agent used may be, for example, 0.1 to 5 parts by mass or 0.5 to 3 parts by mass with respect to 100 parts by mass of silica.

The content of silica may be 50 to 400 parts by mass or 100 to 400 parts by mass with respect to 100 parts by mass of polyphenylene ether. Alternatively, the silica content may be 10 to 30% by mass based on the total solid content of the composition.

(Other ingredients)
The curable composition may contain a peroxide. The curable composition may also contain a cross-linking curing agent. In addition, the curable composition may contain other components as long as the effects of the present invention are not impaired.

The peroxide has an action of opening an unsaturated carbon bond contained in a preferable polyphenylene ether and promoting a cross-linking reaction.

Examples of peroxides include methyl ethyl ketone peroxide, methyl acetoacetate peroxide, acetyl aceto peroxide, 1,1-bis (t-butyl peroxy) cyclohexane, 2,2-bis (t-butyl peroxy) butane, and t. -Butylhydroperoxide, cumenehydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutylhydroperoxide, di-t -Butylhydroperoxide, t-butylhydroperoxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di ( t-butylperoxy) hexine, 2,5-dimethyl-2,5-di (t-butylperoxy) -3-butene, acetyl peroxide, octanoyl peroxide, lauroyl peroxide, benzoyl peroxide, m- Truyl peroxide, diisopropyl peroxydicarbonate, t-butylene peroxybenzoate, di-t-butyl peroxide, t-butyl peroxyisopropyl monocarbonate, α, α'-bis (t-butyl peroxy-m-isopropyl) Examples include benzene. Only one type of peroxide may be used, or two or more types may be used.

Among these peroxides, those having a one-minute half-life temperature of 130 ° C. to 180 ° C. are desirable from the viewpoint of ease of handling and reactivity. Since such peroxides have a relatively high reaction start temperature, it is difficult to accelerate curing when curing is not required, such as during drying, and the polyphenylene ether resin composition does not impair the storage stability and is volatile. Because of its low temperature, it does not volatilize during drying or storage, and its stability is good.

The amount of peroxide added is the total amount of peroxide, preferably 0.01 to 20 parts by mass, and 0.05 to 10 parts by mass with respect to 100 parts by mass of the solid content of the curable composition. Is more preferable, and 0.1 to 10 parts by mass is particularly preferable. By setting the total amount of peroxide in this range, it is possible to prevent deterioration of the film quality at the time of forming a coating film while making the effect at a low temperature sufficient.

Further, if necessary, an azo compound such as azobisisobutyronitrile or azobisisobutyronitrile or a radical initiator such as dicumyl or 2,3-diphenylbutane may be contained.

The cross-linked curing agent reacts with unsaturated carbon bonds contained in a preferable polyphenylene ether to form a three-dimensional cross-link.

As the cross-linking type curing agent, one having good compatibility with polyphenylene ether is used, but a polyfunctional vinyl compound such as divinylbenzene, divinylnaphthalene or divinylbiphenyl; vinylbenzyl synthesized from the reaction of phenol and vinylbenzyl chloride. Ether-based compounds; styrene monomers, allyl ether-based compounds synthesized from the reaction of phenol and allyl chloride; and trialkenyl isocyanurate are preferable. As the cross-linking type curing agent, trialkenyl isocyanurate having particularly good compatibility with polyphenylene ether is preferable, and specifically, triallyl isocyanurate (hereinafter, TAIC®) and triallyl cyanurate (hereinafter, registered trademark) are preferable. TAC) is preferred. These exhibit low dielectric properties and can enhance heat resistance. In particular, TAIC (registered trademark) is preferable because it has excellent compatibility with polyphenylene ether.

Moreover, you may use (meth) acrylate compound (methacrylate compound and acrylate compound) as a cross-linking type curing agent. In particular, it is preferable to use a (meth) acrylate compound having 3 to 5 functions. As the 3- to 5-functional methacrylate compound, trimethylolpropane trimethacrylate or the like can be used, while as the 3- to 5-functional acrylate compound, trimethylolpropane triacrylate or the like can be used. Heat resistance can be improved by using these cross-linking agents. As the cross-linking type curing agent, only one kind may be used, or two or more kinds may be used.

Since the preferred predetermined polyphenylene ether contains a hydrocarbon group having an unsaturated carbon bond, a cured product having excellent dielectric properties can be obtained by curing with a crosslinked curing agent in particular.

The blending ratio of the polyphenylene ether and the crosslinked curing agent is preferably 20:80 to 90:10 by mass, and more preferably 30:70 to 90:10. When the content of polyphenylene ether is 20 parts by mass or more, appropriate toughness is obtained, and when it is 90 parts by mass or less, heat resistance is excellent.

The composition of the present invention may contain a thermosetting catalyst.

As a thermosetting catalyst
Imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1- (2-cyanoethyl) -2- Imidazole derivatives such as ethyl-4-methylimidazole;
Amine compounds such as dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N-dimethylbenzylamine, 4-methyl-N, N-dimethylbenzylamine, adipic acid Hydrazine compounds such as acid dihydrazide and sebacic acid dihydrazide;
Guanamin, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino-S S-triazine derivatives such as -triazine isocyanuric acid adduct, 2,4-diamino-6-methacryloyloxyethyl-S-triazine isocyanuric acid adduct;
Phosphorus compounds such as triphenylphosphine; and the like;

Among these, triphenylphosphine is preferable because yellowing can be prevented even when the cured product is exposed to a temperature of 200 ° C. or higher.

The curable composition is usually provided or used in a state where the polyphenylene ether is dissolved in a solvent (solvent). Since the polyphenylene ether of the present invention has higher solubility in a solvent than the conventional polyphenylene ether, a wide range of solvent options can be selected depending on the use of the curable composition.

Examples of solvents that can be used in the curable composition of the present invention include conventionally usable solvents such as chloroform, methylene chloride, and toluene, as well as N, N-dimethylformamide (DMF), and N-methyl-2-pyrrolidone. Examples thereof include relatively safe solvents such as (NMP), tetrahydrofuran (THF), cyclohexanone, propylene glycol monomethyl ether acetate (PMA), diethylene glycol monoethyl ether acetate (CA), methyl ethyl ketone, ethyl acetate and the like. Only one type of solvent may be used, or two or more types may be used.

The content of the solvent in the curable composition is not particularly limited, and can be appropriately adjusted depending on the use of the curable composition.

<Cured product>
The cured product is obtained by curing the curable composition described above.

The method for obtaining the cured product from the curable composition is not particularly limited, and can be appropriately changed depending on the composition of the curable composition. As an example, after performing a step of applying a curable composition (for example, coating with an applicator or the like) on a substrate as described above, a drying step of drying the curable composition is carried out if necessary. Then, a thermosetting step of thermally cross-linking the polyphenylene ether by heating (for example, heating with an inert gas oven, a hot plate, a vacuum oven, a vacuum press, etc.) may be carried out. The conditions for implementation in each step (for example, coating thickness, drying temperature and time, heating temperature and time, etc.) may be appropriately changed according to the composition, application, and the like of the curable composition.

<Dry film, prepreg>
The dry film or prepreg of the present invention is obtained by applying or impregnating a substrate with the above-mentioned curable composition.

Here, examples of the base material include metal foils such as copper foils, polyimide films, polyester films, films such as polyethylene naphthalate (PEN) films, and fibers such as glass cloth and aramid fibers.

The dry film can be obtained, for example, by applying a curable composition on a polyethylene terephthalate film, drying it, and laminating a polypropylene film as needed.

The prepreg is obtained, for example, by impregnating a glass cloth with a curable composition and drying it.

<Laminate board>
In the present invention, a laminated board can be produced using the above-mentioned prepreg.

More specifically, one or more prepregs of the present invention are laminated, and metal foils such as copper foils are laminated on both upper and lower surfaces or one side thereof, and the laminate is heat-pressed and integrated. A laminated plate having a metal foil on both sides or a metal foil on one side can be produced.

<Electronic components>
Since such a cured product has excellent dielectric properties and heat resistance, it can be used for electronic parts and the like.

The electronic component having a cured product is not particularly limited, but preferably, a large-capacity high-speed communication represented by a 5th generation communication system (5G), a millimeter-wave radar for an automobile ADAS (advanced driver assistance system), and the like can be mentioned. ..

The curable composition of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

<Synthesis of branched PPE>
In a 3 L two-necked eggplant flask, 2.6 g of di-μ-hydroxobis [(N, N, N', N'-tetramethylethylenediamine) copper (II)] chloride (Cu / TMEDA) and tetramethyl 3.18 mL of ethylenediamine (TMEDA) was added to dissolve it sufficiently, and oxygen was supplied at 10 ml / min. A raw material solution was prepared by dissolving 105 g of 2,6-dimethylphenol, 2-allylphenol and 13 g of raw material phenols in 1.5 L of toluene. This raw material solution was added dropwise to the flask, and the mixture was reacted at 40 ° C. for 6 hours with stirring at a rotation speed of 600 rpm. After completion of the reaction, the mixture was reprecipitated with a mixed solution of 20 L of methanol and 22 mL of concentrated hydrochloric acid, removed by filtration, and dried at 80 ° C. for 24 hours to obtain branched PPE. The branched PPE was soluble in various organic solvents such as cyclohexanone, N-methylpyrrolidone (NMP) and tetrahydrofuran (THF). The number average molecular weight of the branched PPE was 20,000, and the weight average molecular weight was 60,000. The slope of the conformation plot was 0.31.

<Synthesis of non-branched PPE>
Synthesis similar to branched PPE except that 34 mL of water was added to a raw material solution in which 7.6 g of 2-allyl-6-methylphenol and 34 g of 2,6-dimethylphenol, which are raw material phenols, were dissolved in 0.23 L of toluene. Non-branched PPE was obtained based on the method. The non-branched PPE was not soluble in cyclohexanone and was soluble in chloroform. The number average molecular weight of the non-branched PPE was 1,000, and the weight average molecular weight was 2,000.

Mix with various components shown in Examples, Comparative Examples, and Reference Examples at the ratio (parts by mass) shown in Table 1, stir for 15 minutes with a stirrer to premix, then knead with a 3-roll mill, and heat. A curable resin composition was prepared.

Each composition varnish and the cured film obtained from it were evaluated by the following evaluation methods. The results are also shown in Table 1.

<Environmental support>
As an environmentally friendly evaluation, a composition using cyclohexanone as a solvent was evaluated as “◯”, and a composition using chloroform as a solvent was evaluated as “x”.

<Adhesion (peeling strength)>
Adhesion (peeling strength against low-roughness copper foil) was measured in accordance with the copper-clad laminate test standard JIS-C-6481. A resin composition is applied to the rough surface of a low-roughness copper foil (FV-WS (manufactured by Furukawa Electric Co., Ltd.): Rz = 1.5 μm) so that the thickness of the cured product is 50 μm, and the hot air circulation type drying oven is used. It was dried at 90 ° C. for 30 minutes. Then, it was completely filled with nitrogen using an inert oven, heated to 200 ° C., and then cured for 60 minutes. An epoxy adhesive (Araldide) is applied to the obtained cured film side, a copper-clad laminate (length 150 mm, width 100 mm, thickness 1.6 mm) is placed on the cured film, and the film is cured in a hot air circulation drying oven at 60 ° C. for 1 hour. It was. Next, a notch having a width of 10 mm and a length of 100 mm was made in the low-roughness copper foil portion, and one end of the notch was peeled off and grasped with a gripper to measure the 90 ° peel strength.
[Measurement condition]
Testing machine: Tensile testing machine EZ-SX (manufactured by Shimadzu Corporation)
Measurement temperature: 25 ° C
Stroke: 35mm
Stroke speed: 50 mm / min
Number of measurements: Calculate the average value of 5 times

90 ° peel strength of 7.0 N / cm or more is "◎", 6.0 N / cm or more is "○", 2 or more and less than 6.0 N / cm is "△", and less than 2. Was evaluated as "x".

(Preparation of cured film)
The varnish of the obtained resin composition was applied to the shine surface of a copper foil having a thickness of 18 μm with an applicator so that the thickness of the cured product was 50 μm. Next, it was dried at 90 ° C. for 30 minutes in a hot air circulation type drying oven. Then, nitrogen was completely filled using an inert oven, the temperature was raised to 200 ° C., and the mixture was cured for 60 minutes. Then, the copper foil was removed by etching to obtain a cured film. The following evaluation was performed using this cured film.

<Compatibility>
As the compatibility, those in which no spots were visually observed on the coating film were evaluated as "◯", and those in which spots were visually observed on the coating film were evaluated as "x".

<Breaking elongation and tensile strength>
The cured film was cut into a length of 8 cm, a width of 0.5 cm, and a thickness of 50 μm, and the tensile elongation at break and the tensile strength (tensile breaking strength) were measured under the following conditions.
[Measurement condition]
Testing machine: Tensile testing machine EZ-SX (manufactured by Shimadzu Corporation)
Distance between chucks: 50 mm
Test speed: 1 mm / min
Elongation calculation: (tensile movement amount / distance between chucks) x 100

Tensile breaking elongation of 4.0% or more is "◎", 3.5% or more is "○", 1.0% or more and less than 3.5% is "△", less than 1.0% Those were evaluated as "x".

Those having a tensile strength of 70 MPa or more were evaluated as "⊚", those having a tensile strength of 60 MPa or more were evaluated as "◯", those having a tensile strength of 20 MPa or more and less than 60 MPa were evaluated as "Δ", and those having a tensile strength of less than 20 MPa were evaluated as "x".

<Dielectric property>
The dielectric loss tangent Df, which is a dielectric property, was measured according to the following method.
The cured film was cut into a length of 80 mm, a width of 45 mm, and a thickness of 50 μm, and this was measured as a test piece by the SPDR (Split Post Dielectric Resonator) resonator method. The measuring instrument used was a vector network analyzer E5071C manufactured by Keysight Technologies, Inc., an SPDR resonator, and the calculation program used was manufactured by QWED. The conditions were a frequency of 10 GHz and a measurement temperature of 25 ° C.

As the dielectric property evaluation, those having a Df of less than 0.01 were evaluated as "◯", and those having a Df of 0.01 or more were evaluated as "x".

<Heat resistance>
The heat resistance was evaluated by the glass transition temperature. The cured film was cut into a length of 30 mm, a width of 5 mm, and a thickness of 50 μm, and the glass transition temperature (Tg) was measured with DMA7100 (manufactured by Hitachi High-Tech Science Co., Ltd.). The temperature range was 30 to 280 ° C., the heating rate was 5 ° C./min, the frequency was 1 Hz, the strain amplitude was 7 μm, the minimum tension was 50 mN, and the distance between the grippers was 10 mm. The glass transition temperature (Tg) was defined as the temperature at which tan δ showed the maximum.

A glass transition temperature (Tg) of 220 ° C or higher is marked with "◎", a glass transition temperature of 200 ° C or higher is marked with "○", a glass transition temperature (Tg) of 170 ° C or higher and lower than 200 ° C is marked with "△", and a glass transition temperature (Tg) of lower than 170 ° C is marked with "x". evaluated.

Claims (6)

Polyphenylene ether composed of raw material phenols including phenols satisfying at least condition 1 and
A curable composition containing a cyanate ester resin.
(Condition 1)
Has hydrogen atoms at the ortho and para positions Part or all of the polyphenylene ether
Phenols (A) that satisfy at least both the following condition 1 and the following condition 2, or phenols (B) that satisfy at least the following condition 1 and do not satisfy the following condition 2 and phenols that do not satisfy the following condition 1 and satisfy the following condition 2 The curable composition according to claim 1, which is a polyphenylene ether composed of a raw material phenol containing a mixture of class (C).
(Condition 1)
It has hydrogen atoms at the ortho and para positions (Condition 2)
It has a hydrogen atom at the para position and has a functional group containing an unsaturated carbon bond. A dry film or prepreg obtained by applying or impregnating a substrate with the curable composition according to any one of claims 1 and 2. A cured product obtained by curing the curable composition according to any one of claims 1 to 2. A laminated board comprising the cured product according to claim 4. An electronic component having the cured product according to claim 4.