JP2020055998A - Curable composition, dry film, cured product and electronic component - Google Patents

Abstract

To provide a curable composition capable of obtaining a cured product which contains a thermosetting polyphenylene ether soluble in various solvents and has excellent dielectric properties and self-extinguishing properties.SOLUTION: There is provided a curable composition which comprises a polyphenylene ether comprising raw material phenols containing phenols (A) satisfying both at least the following condition 1 and the following condition 2, or, a mixture of phenols (B) which satisfy at least the following condition 1 and do not satisfy the following condition 2 and phenols (C) which do not satisfy the following condition 1 and satisfy the following condition 2 and silica. (Condition 1) Having hydrogen atoms at the ortho-position and the para-position. (Condition 2) Having a functional group which has a hydrogen atom at the para-position and contains an unsaturated carbon bond.SELECTED DRAWING: None

Description

  The present invention relates to a curable composition containing polyphenylene ether, a dry film, a prepreg, a cured product, a laminate, and an electronic component.

  With the spread of high-capacity high-speed communication represented by the fifth generation communication system (5G), millimeter-wave radar for automotive ADAS (advanced driving system), and the like, the frequency of signals of communication devices has been increased.

  However, when an epoxy resin or the like is used as a wiring board material, the relative dielectric constant (Dk) and the dielectric loss tangent (Df) are not sufficiently low. Therefore, as the frequency becomes higher, the transmission loss due to the dielectric loss increases. Problems such as attenuation and heat generation have occurred. For this reason, polyphenylene ethers having excellent low dielectric properties have been used. However, since polyphenylene ether is a thermoplastic resin, there is a problem of heat resistance.

  As a means for solving the problem, Non-Patent Document 1 proposes to introduce an allyl group 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 soluble solvent of polyphenylene ether is limited, and the polyphenylene ether obtained by the method of Non-Patent Document 1 is also dissolved only in highly toxic solvents such as chloroform and toluene. For this reason, there is a problem that it is difficult to handle the resin varnish and to control the solvent exposure in a process of forming a coating film and curing such as a wiring board application.

Under the above-mentioned problems, the present inventors have disclosed in Japanese Patent Application No. 2018-134338 that while maintaining low dielectric properties, it is soluble in various solvents (organic solvents other than highly toxic organic solvents, for example, cyclohexanone). Invented polyphenylene ether.
However, there is a demand for a low dielectric loss tangent to cope with high frequencies and an improvement in self-extinguishing properties of electronic components.

  Therefore, the present invention provides a curable composition containing polyphenylene ether which is soluble in various solvents (organic solvents other than highly toxic organic solvents, for example, cyclohexanone), and realizes a low dielectric loss tangent and a self-extinguishing property. It is an object to provide a curable composition suitable for obtaining a cured product having the same.

  The present inventors have conducted intensive studies for realizing the above object, and as a result, completed the present invention by using a combination of polyphenylene ether and silica with a specific phenol as a raw material.

That is, the present invention provides a raw material phenol (A) that satisfies at least the following conditions 1 and 2 or a phenol (B) that satisfies at least the following condition 1 and does not satisfy the following condition 2 and satisfies the following condition 1 A polyphenylene ether comprising a raw material phenol containing a mixture of phenols (C) satisfying the following condition 2:
A curable composition characterized by containing silica.
(Condition 1)
Has hydrogen atoms in ortho and para positions (condition 2)
Has a hydrogen atom at the para position and a functional group containing an unsaturated carbon bond

In the present invention, the raw material phenols (A) satisfying at least both of the following conditions 1 and 2 or the phenols (B) satisfying at least the following conditions 1 and not satisfying the following conditions 2 are preferably used. A polyphenylene ether comprising a raw material phenol containing a mixture of phenols (C) not satisfying Condition 1 but satisfying Condition 2 below, and having a slope calculated by a conformation plot of less than 0.6;
Another object of the present invention is to provide a curable composition characterized by containing silica.
(Condition 1)
Has hydrogen atoms in ortho and para positions (condition 2)
Has a hydrogen atom at the para position and a functional group containing an unsaturated carbon bond

  The curable composition may further contain a thermoplastic elastomer.

  The curable composition may further contain a phosphorus-containing flame retardant.

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

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

  Further, the present invention provides a laminated board including the cured product.

  Further, the present invention provides an electronic component having the cured product.

  According to the present invention, a curable composition containing a polyphenylene ether that is also soluble in various solvents, the curable composition being suitable for achieving a low dielectric loss tangent and obtaining a cured product having self-extinguishing properties Can be provided.

  The entire description of Japanese Patent Application No. 2018-1433338 is incorporated by reference and incorporated herein.

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

  In the present invention, “unsaturated carbon bond” indicates an ethylenic or acetylenic carbon-carbon multiple bond (double bond or triple bond) unless otherwise specified.

  In the present invention, when describing the raw material phenols as "ortho position" or "para position", 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 ortho positions” or the like. Therefore, unless otherwise contradicted, when the term “ortho position” is simply used, it may be interpreted to indicate one of the ortho positions or to indicate both the ortho positions.

  In the present invention, phenols that are used as a raw material of polyphenylene ether and can be a structural unit of polyphenylene ether are collectively referred to as “raw phenols”.

  The curable composition of the present invention contains a predetermined polyphenylene ether (PPE) described below.

  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 based on the total solid content of the composition.

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

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

  The composition of the present invention is a phenol (A) that satisfies at least the following conditions 1 and 2 or a phenol (B) that satisfies at least the following condition 1 and does not satisfy the following condition 2 and satisfies the following condition 1 In addition, it is characterized by containing polyphenylene ether composed of a raw material phenol containing a mixture of phenols (C) satisfying the following condition 2, and silica.

Specifically, the polyphenylene ether is
(Mode 1) Phenols satisfying at least both of the following conditions 1 and 2 (A) Raw phenols containing as an essential component, or
(Form 2) Raw material phenols containing at least a mixture of a phenol (B) that satisfies the following condition 1 and does not satisfy the following condition 2 and a phenol (C) that does not satisfy the following condition 1 and satisfies the following condition 2 ,
Is obtained by oxidative polymerization of
(Condition 1)
Has hydrogen atoms in ortho and para positions (condition 2)
Has a hydrogen atom at the para position and a functional group containing an unsaturated carbon bond

  Here, phenols satisfying the condition 1 (for example, phenols (A) and phenols (B)) have a hydrogen atom in the ortho position, and therefore, when oxidized and polymerized with the phenol, the phenols are in the ipso position and the para position. In addition, since an ether bond can be formed at the ortho position, a branched structure can be formed.

  Phenols that do not satisfy condition 1 (for example, phenols (C) and phenols (D) below) form ether bonds at the ipso and para positions when oxidatively polymerized, and are polymerized linearly. Will be done.

  Phenols satisfying the condition 2 (for example, phenols (A) and phenols (C)) have a hydrocarbon group containing at least an unsaturated carbon bond. Therefore, a polyphenylene ether synthesized from a phenol satisfying the 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 polyphenylene ether is branched by a 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 at least a branched structure represented by the formula (5) in a skeleton, and is considered to be a compound having a hydrocarbon group containing at least one unsaturated carbon bond as a functional group.

In the formula (5), R _{a to} R _k are a hydrogen atom or a hydrocarbon group having 1 to 15 carbon atoms (preferably having 1 to 12 carbon atoms). However, at least one of R _{a to} R _k is a hydrocarbon group having an unsaturated carbon bond.

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

  It is preferable that the polyphenylene ether is in the form 2 or in the form 1 in which the phenol (B) and / or the phenol (C) is contained as a further essential component.

  The raw 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, having no hydrogen atom at the ortho-position, and having no functional group containing an unsaturated carbon bond. Can be

  In any of the above-described embodiments 1 and 2, it is preferable that phenols (D) be further contained as a raw material phenol in order to increase the molecular weight of the polyphenylene ether.

  It is most preferable that the polyphenylene ether is a form in which the phenol (D) is further contained as the raw material phenol in the above-mentioned form 2.

  Furthermore, in the above-mentioned form 2, from the industrial and economical viewpoint, the phenol (B) is at least one of o-cresol, 2-phenylphenol, 2-dodecylphenol and phenol, (C) is preferably 2-allyl-6-methylphenol.

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

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

In the formula (1), R _{1 to} R ₃ are a hydrogen atom or a hydrocarbon group 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 that it is easy to polymerize 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- Allyl-5-ethylphenol and the like can be exemplified. As the phenol represented by the formula (1), only one kind may be used, or two or more kinds may be used.

  As described above, the phenol (B) satisfies the condition 1 and does not satisfy the condition 2, that is, has a hydrogen atom in the ortho position and the para position, and has no functional group containing an unsaturated carbon bond. Phenols, and preferably phenols (b) represented by the following formula (2).

In the formula (2), R _{4 to} R ₆ are a hydrogen atom or a hydrocarbon group having 1 to 15 carbon atoms. However, R _{4 to} R ₆ do not have an unsaturated carbon bond. The hydrocarbon group preferably has 1 to 12 carbon atoms from the viewpoint that it is easy to polymerize 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 -Xylenol, o-tert-butylphenol, m-tert-butylphenol, o-phenylphenol, m-phenylphenol, 2-dodecylphenol, and the like. As the phenol 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) do not satisfy the condition 1 and satisfy the condition 2, that is, they have a hydrogen atom at the para position, no hydrogen atom at the ortho position, and an unsaturated carbon bond. And a phenol (c) represented by the following formula (3).

In the formula (3), R ₇ and R ₁₀ are a hydrocarbon group having 1 to 15 carbon atoms, and R ₈ and R ₉ are a hydrogen atom or a hydrocarbon group 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 that it is easy to polymerize 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, and 2-vinyl-6-ethylphenol. As the phenol 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, having no hydrogen atom at the ortho-position, and having no functional group containing an unsaturated carbon bond. A phenol (d) represented by the formula (4).

In the formula (4), R ₁₁ and R ₁₄ are a hydrocarbon group having 1 to 15 carbon atoms having no unsaturated carbon bond, and R ₁₂ and R ₁₃ have no hydrogen atom or no 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 that it is easy to polymerize 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. As the phenol 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, an alkynyl group, and the like, and preferably an alkyl group, an aryl group, and an alkenyl group. 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.

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

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

  The ratio of the phenol satisfying the condition 2 to the total of the raw material phenols is preferably 0.5 to 99 mol%, more preferably 1 to 99 mol%.

  The polyphenylene ether obtained by oxidatively polymerizing the raw material phenols described above by a known and commonly used method preferably has a number average molecular weight of 2,000 to 30,000. It is more preferably from 5,000 to 30,000, further preferably from 8,000 to 30,000, and particularly preferably from 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 addition, 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.

  Here, the branched structure (degree of branching) of 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, and 0.25 mg / mL, a graph of the refractive index difference and the concentration was created while sending the solution at 0.5 mL / min. , The refractive index increment dn / dc is calculated from the slope. Next, the absolute molecular weight is measured under the following apparatus operating conditions. With reference to the chromatogram of the RI detector and the chromatogram of the MALS detector, a regression line by the least square method is obtained from a logarithmic graph (conformation plot) of the molecular weight and the radius of gyration, and the slope is calculated.

<Measurement conditions>
Equipment name: HLC8320GPC
Mobile phase: chloroform Column: TOSOH TSKguardcolumnHHR-H
+ TSKgel GMHHR-H (2)
+ TSKgelG2500HHR
Flow rate: 0.6 mL / min.
Detector: DAWN HELEOS (MALS detector)
+ Optilab rEX (RI detector, wavelength 254 nm)
Sample concentration: 0.5mg / 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. Dissolution analysis of 15 mg of sample in 10 mL of mobile phase: 100 min

  In a resin having the same absolute molecular weight, the distance (rotation radius) from the center of gravity to each segment becomes smaller as the branching of the polymer chain progresses. 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 advanced the branching. In the present invention, the smaller the slope calculated from the conformation plot, the more the polyphenylene ether branches, and the larger the slope, the less the polyphenylene ether branches.

  In the polyphenylene ether, the inclination is, for example, less than 0.6 and preferably 0.55 or less, 0.50 or less, 0.45 or less, or 0.40 or less. When the inclination is within 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 supplied oxygen, and the amount of solvent in the synthesis of polyphenylene ether. More specifically, 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 reduces the slope of the conformation plot. (The polyphenylene ether is more likely to be branched).

  1 g of polyphenylene ether is soluble at 25 ° C., preferably in 100 g of cyclohexanone (more preferably in 100 g of cyclohexanone, DMF and PMA). In addition, that 1 g of polyphenylene ether is soluble in 100 g of a solvent (for example, cyclohexanone) indicates that when 1 g of polyphenylene ether and 100 g of the solvent are mixed, turbidity and precipitation cannot be visually confirmed. The polyphenylene ether of the present invention is more preferably soluble in 100 g of cyclohexanone at 25 ° C. in an amount of 1 g or more.

  Such a polyphenylene ether can be produced by applying a conventionally known method for synthesizing a polyphenylene ether (polymerization conditions, presence / absence of a catalyst, type of a catalyst, etc.) except that a specific phenol is used as a raw material phenol. It is possible.

  The curable composition of the present invention contains silica. By blending silica in the composition, the self-extinguishing property and low dielectric loss tangent of the cured product can be realized at a high level.

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

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

  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. Further, the affinity with an organic solvent can be improved.

  As the silane coupling agent, for example, an epoxy silane coupling agent, a mercapto silane coupling agent, a vinyl silane coupling agent and 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 can be used. As the vinyl silane coupling agent, for example, vinyl triethoxy silane 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 compounding amount of silica may be 200 to 600 parts by mass based on 100 parts by mass of polyphenylene ether. In other words, the compounding amount of silica may be 40 to 80% by mass based on the total solid content of the composition.

  The curable composition of the present invention preferably contains a thermoplastic elastomer. By blending a thermoplastic elastomer into the composition, the tensile properties of the cured product can be improved. Although the cured product of polyphenine ether used in the present invention has a low elongation at break and tends to be brittle, the combined use of a thermoplastic elastomer can improve the elongation at break while maintaining dielectric properties.

  Examples of the thermoplastic elastomer include a styrene elastomer, an olefin elastomer, a urethane elastomer, a polyester elastomer, a polyamide elastomer, an acrylic elastomer, and a silicone elastomer. Styrene-based elastomers are particularly preferred because of their high compatibility with polyphenylene ether and high dielectric properties.

  Styrene-based elastomers include styrene-butadiene copolymers such as styrene-butadiene-styrene block copolymers; styrene-isoprene copolymers such as styrene-isoprene-styrene block copolymers; styrene-ethylene-butylene-styrene block copolymers; Ethylene-propylene-styrene block copolymer and the like can be mentioned. In addition, hydrogenated products of these copolymers may be mentioned.

  The content ratio of the styrene block in the styrene-based elastomer is preferably 20 to 70 mol%.

  Here, the raw material monomer of the styrene-based elastomer includes not only styrene but also styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene, and 4-cyclohexylstyrene.

  The weight average molecular weight of the thermoplastic elastomer may be between 1,000 and 300,000 or between 2,000 and 150,000. When the weight average molecular weight is not less than the lower limit, excellent low thermal expansion property is obtained, and when it is not more than the upper limit, compatibility with other components is excellent. The weight average molecular weight of the thermoplastic elastomer is measured by GPC and converted by a calibration curve prepared using standard polystyrene.

  The blending amount of the thermoplastic elastomer may be 30 to 100 parts by mass with respect to 100 parts by mass of the polyphenylene ether. In other words, the blending amount of the thermoplastic elastomer may be 3 to 20% by mass based on the total solid content of the composition. When it is in the above range, good curability, moldability and chemical resistance can be realized in a well-balanced manner.

  The curable composition preferably contains a phosphorus-containing flame retardant. By blending a phosphorus-containing flame retardant into the composition, the self-extinguishing property of a cured product obtained by curing the composition can be improved.

  Examples of the phosphorus-containing flame retardant include phosphoric acid or an ester thereof, and phosphorous acid or an ester thereof. Alternatively, these condensates may be mentioned.

  The phosphorus-containing flame retardant is preferably compatible with polyphenylene ether from the viewpoint of high filling of silica. On the other hand, there was a risk that the phosphorus-containing flame retardant would bleed out.

  In a preferred embodiment that reduces the risk of bleed-out, the phosphorus-containing flame retardant has one or more unsaturated carbon bonds in the molecular structure. When the composition is cured, the phosphorus-containing flame retardant having an unsaturated carbon bond can react with the unsaturated carbon bond of the polyphenylene ether to be integrated. As a result, the risk of bleeding out of the phosphorus-containing flame retardant is reduced.

  In a particularly preferred embodiment of the present invention, the phosphorus-containing flame retardant has a plurality of unsaturated carbon bonds in the molecular structure. These phosphorus-containing flame retardants having a plurality of unsaturated carbon bonds can also function as a crosslinking type curing agent described later. From the viewpoint of contributing to the crosslinking of the polyphenylene ether of the present invention, the phosphorus-containing flame retardant having a plurality of unsaturated carbon bonds can be expressed as a phosphorus-containing crosslinking curing agent or a phosphorus-containing crosslinking assistant.

  The phosphoric acid or its ester is a compound represented by the following formula (6).

In the formula (6), R _{61 to} R ₆₃ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 15 (preferably 1 to 12) carbon atoms. The hydrocarbon group may have an unsaturated carbon bond. Further, the hydrocarbon group may contain one or more hetero atoms such as oxygen, nitrogen, and sulfur. However, if these hetero atoms are included, the polarity becomes high, which may adversely affect the dielectric properties. Therefore, it is preferable that the hydrocarbon group does not contain any hetero atoms. Examples of such a hydrocarbon group typically include a methyl group, an ethyl group, an octyl group, a phenyl group, a cresyl group, a butoxyethyl group, a vinyl group, an allyl group, an acryloyl group, and a methacryloyl group.

  Examples of the phosphoric ester include trimethyl phosphate, triethyl phosphate, tributyl phosphate, trioctyl phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, and tri (2-ethylhexyl). Phosphate, diisopropylphenyl phosphate, trixylenyl phosphate, tris (isopropylphenyl) phosphate, trinaphthyl phosphate, bisphenol A bisphosphate, hydroquinone bisphosphate, resorcinol bisphosphate, resorcinol-diphenyl phosphate, trioxybenzene triphosphate.

  Examples of the phosphate having an unsaturated carbon bond in the molecular structure include trivinyl phosphate, triallyl phosphate, triacryloyl phosphate, trimethacryloyl phosphate, trisacryloyloxyethyl phosphate, and trismethacryloyloxyethyl ethyl phosphate.

  The phosphorous acid or an ester thereof is a compound represented by the following formula (7).

In the formula (7), the description of R _{61 to} R _{63 in} the formula (6) applies to R _{71 to} R ₇₃ .

  Examples of the phosphite include trimethyl phosphite, triethyl phosphite, tributyl phosphite, trioctyl phosphite, tributoxyethyl phosphite, triphenyl phosphite, tricresyl phosphite, cresyl diphenyl phosphite, octyl Diphenyl phosphite, tri (2-ethylhexyl) phosphite, diisopropyl phenyl phosphite, trixylenyl phosphite, tris (isopropyl phenyl) phosphite, trinaphthyl phosphite, bisphenol A bisphosphite, hydroquinone bisphosphite, resorcin bis Examples include phosphite, resorcinol-diphenyl phosphite, and trioxybenzene triphosphite.

  Examples of the phosphite having an unsaturated carbon bond in the molecular structure include trivinyl phosphite, triallyl phosphite, triacryloyl phosphite, and trimethacryloyl phosphite.

  The content of the phosphorus-containing flame retardant may be 1 to 5% by mass as the phosphorus amount based on the total solid content of the composition. Within the above-mentioned range, a self-extinguishing property, heat resistance and dielectric properties of a cured product obtained by curing the composition can be achieved at a high level in a well-balanced manner.

  The curable composition may include a peroxide. Further, the curable composition may contain a cross-linking type curing agent. Further, the curable composition may contain other components as long as the effects of the present invention are not impaired.

  The peroxide has an effect of opening an unsaturated carbon bond contained in the polyphenylene ether of the present invention and promoting a crosslinking reaction.

  As the peroxide, methyl ethyl ketone peroxide, methyl acetoacetate peroxide, acetyl aceto peroxide, 1,1-bis (t-butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) butane, t -Butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, di-t -Butyl hydroperoxide, t-butyl hydroperoxide, dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di ( t-butylperoxy) hexyne, 2,5-di Tyl-2,5-di (t-butylperoxy) -3-butene, acetyl peroxide, octanoyl peroxide, lauroyl peroxide, benzoyl peroxide, m-toluyl peroxide, diisopropylperoxydicarbonate, t- Butylene peroxybenzoate, di-t-butyl peroxide, t-butyl peroxyisopropyl monocarbonate, α, α′-bis (t-butylperoxy-m-isopropyl) benzene, and the like. Peroxide may be used alone or in combination of two or more.

  Among these, those having a one-minute half-life temperature of 130 ° C. to 180 ° C. are desirable among these from the viewpoint of ease of handling and reactivity. Since such a peroxide has a relatively high reaction initiation temperature, it is difficult to promote curing at a point where curing is not necessary, such as during drying, and does not deteriorate the storage stability of the polyphenylene ether resin composition, and , It does not volatilize during drying or storage and has good stability.

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

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

  The cross-linking type curing agent cross-links polyphenylene ether three-dimensionally. The crosslinkable curing agent that is also a phosphorus-containing compound (phosphorus-containing flame retardant) is particularly called a phosphorus-containing crosslinkable curing agent. The cross-linking curing agent may particularly mean a cross-linking curing agent containing no phosphorus (a phosphorus-free cross-linking curing agent).

  As the cross-linking type curing agent, one having good compatibility with polyphenylene ether is used. Polyfunctional vinyl compounds such as divinylbenzene, divinylnaphthalene, and divinylbiphenyl; vinylbenzyl synthesized from the reaction of phenol and vinylbenzyl chloride Preferred are ether compounds; styrene monomers, allyl ether compounds synthesized from the reaction of phenol and allyl chloride; and trialkenyl isocyanurates. As the cross-linking type curing agent, trialkenyl isocyanurate having particularly good compatibility with polyphenylene ether is preferred, and specifically, triallyl isocyanurate (hereinafter, TAIC (registered trademark)) and triallyl cyanurate (hereinafter, referred to as triaryl cyanurate) TAC) is preferred. These exhibit low dielectric properties and can increase heat resistance. Particularly, TAIC (registered trademark) is preferable because it has excellent compatibility with polyphenylene ether.

  Further, a (meth) acrylate compound (methacrylate compound and acrylate compound) may be used as the cross-linking curing agent. In particular, it is preferable to use a 3- to 5-functional (meth) acrylate compound. As the 3- to 5-functional methacrylate compound, trimethylolpropane trimethacrylate or the like can be used. On the other hand, as the 3- to 5-functional acrylate compound, trimethylolpropane triacrylate or the like can be used. Use of these crosslinking agents can increase heat resistance. As the crosslinking type curing agent, only one type may be used, or two or more types may be used.

  Although the polyphenylene ether of the present invention has a branched structure, it is difficult to improve the dielectric properties while improving the solubility with various solvents, but it contains a hydrocarbon group having an unsaturated carbon bond. By curing with a crosslinking type curing agent, a cured product having excellent dielectric properties can be obtained.

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

  The curable composition is usually provided or used in a state in which polyphenylene ether is dissolved in a solvent (solvent). Since the polyphenylene ether of the present invention has higher solubility in a solvent than conventional polyphenylene ether, the choice of the solvent to be used can be broadened according to the use of the curable composition.

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

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

  The curable composition may contain a known and commonly used raw material such as a resin other than the polyphenylene ether of the present invention and other additives as long as the effects of the present invention are not impaired. For example, it may contain an inorganic filler other than silica or a flame retardant containing no phosphorus atom.

  In addition, such a curable composition is obtained by mixing and dispersing each raw material. The composition of the present invention is a composition containing polyphenylene ether which is also soluble in various solvents, and is suitable for realizing a low dielectric loss tangent and obtaining a cured product having self-extinguishing properties. Can be applied to

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

  The method for obtaining a cured product from the curable composition is not particularly limited, and can be appropriately changed according to the composition of the curable composition. As an example, after performing a step of applying the curable composition on the substrate as described above (for example, applying with an applicator or the like), performing a drying step of drying the curable composition as necessary Then, a heat curing step of thermally crosslinking the polyphenylene ether by heating (for example, heating with an inert gas oven, a hot plate, a vacuum oven, a vacuum press, or the like) may be performed. 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 and use of the curable composition.

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

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

  The dry film is obtained, for example, by coating and drying the curable composition on a polyethylene terephthalate film and, if necessary, laminating a polypropylene film.

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

<Laminated plate>
In the present invention, a laminate can be manufactured using the above-described prepreg.

  More specifically, one or more prepregs of the present invention are stacked, and further, a metal foil such as a copper foil is stacked on both upper and lower surfaces or one surface thereof, and the laminate is laminated and integrated by heating and pressing. Further, a laminate having metal foil on both sides or 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 the cured product is not particularly limited, but preferably includes a large-capacity high-speed communication represented by a fifth generation communication system (5G), a millimeter wave radar for an ADAS (advanced driving system) of an automobile, and the like. .

  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.

<<< Preparation of composition >>>
The preparation procedure of each composition (the compositions of Examples 1 to 6, Reference Examples 1 to 3, and Comparative Examples 1 and 2) will be described below.

<Description of Synthesis Example A of Polyphenylene Ether for Examples and Reference Examples>
5.3 g of di-μ-hydroxo-bis [(N, N, N ′, N′-tetramethylethylenediamine) copper (II)] chloride (Cu / TMEDA) and tetramethyl 5.7 mL of ethylenediamine (TMEDA) was added to sufficiently dissolve, and oxygen was supplied at 10 ml / min. A raw material solution was prepared by dissolving 10.1 g of raw material phenols, 13.8 g of 2-allyl-6-methylphenol, and 91.1 g of 2,6-dimethylphenol in 1.5 L of toluene. This raw material solution was dropped into the flask, and reacted at 40 ° C. for 6 hours while stirring at a rotation speed of 600 rpm. After completion of the reaction, the precipitate was reprecipitated with a mixed solution of 20 L of methanol: 22 mL of concentrated hydrochloric acid, taken out by filtration, and dried at 80 ° C. for 24 hours to obtain a terpolymer PPE resin.

  The PPE resin of Synthesis Example A was soluble in various organic solvents such as cyclohexanone, N, N-dimethylformamide (DMF), and propylene glycol monomethyl ether acetate (PMA). The number average molecular weight of the PPE resin of Synthesis Example A was 12,700, and the weight average molecular weight was 77,470.

  The slope of the conformation plot of Synthesis Example A was 0.32.

<Description of Synthesis Example B of Polyphenylene Ether for Comparative Example>
The same synthesis as the terpolymer PPE resin except that a raw material solution obtained by dissolving 13.8 g of 2-allyl-6-methylphenol and 103 g of 2,6-dimethylphenol as raw material phenols in 0.38 L of toluene was used. A binary copolymerized PPE resin was obtained by the method.

  The PPE resin of Synthesis Example B was not soluble in cyclohexanone, but was soluble in chloroform. The number average molecular weight of the PPE resin of Synthesis Example B was 19,000, and the weight average molecular weight was 39,900.

  The slope of the conformation plot of Synthesis Example B was 0.61.

  The number average molecular weight (Mn) and weight average molecular weight (Mw) of each PPE resin were determined by gel permeation chromatography (GPC). In GPC, Shodex K-805L was used as a column, the column temperature was 40 ° C., the flow rate was 1 mL / min, the eluent was chloroform, and the standard substance was polystyrene.

<Preparation of composition of Example 1>
To 15.9 parts by mass of the PPE resin of Synthesis Example A, 80 parts by mass of cyclohexanone was added as a solvent, mixed at 40 ° C. for 30 minutes, stirred and completely dissolved. In the PPE resin solution thus obtained, 15.9 parts by mass of TAIC (manufactured by Mitsubishi Chemical Corporation) and 60.2 parts by mass of spherical silica (manufactured by Admatechs Co., Ltd .: trade name “SC2500-SVJ”) are used as a crosslinking type curing agent. The mixture was added and mixed, and then dispersed by a three-roll mill. Finally, 0.6 parts by mass of α, α′-bis (t-butylperoxy-m-isopropyl) benzene (trade name “Perbutyl P” manufactured by NOF Corporation) as a curing catalyst was blended and mixed. Thereafter, the mixture was dispersed by a three-roll mill. Thus, a varnish of the resin composition of Example 1 was obtained.

<Preparation of composition of Example 2>
A varnish of the resin composition of Example 2 was obtained in the same procedure as in Example 1, except that 7.5 parts by mass of the hydrogenated styrene-based thermoplastic elastomer was further added.

<Preparation of compositions of Examples 3 to 5>
Except that TAIC was changed to triallyl phosphite, trisacryloyloxyethyl phosphate, and trismethacrylolyloxyethyl phosphate, respectively, the varnish of the resin composition of Examples 3-5 was performed in the same procedure as Example 2. Obtained.

<Preparation of composition of Example 6>
A varnish of the resin composition of Example 6 was obtained in the same procedure as in Example 5, except that the silica was not surface-treated.

<Preparation of compositions of Reference Examples 1 and 2>
A varnish of the resin compositions of Reference Examples 1 and 2 was obtained in the same procedure as in Examples 1 and 2, except that silica was not blended.

<Preparation of composition of Reference Example 3>
A varnish of the resin composition of Reference Example 3 was obtained in the same procedure as in Example 2, except that silica was changed to 20 parts by mass of alumina.

<Preparation of Compositions of Comparative Examples 1 and 2>
A varnish of the resin composition of Comparative Examples 1-2 was obtained in the same procedure as in Examples 2-3 except that the PPE resin according to the present invention was changed to the PPE resin of Synthesis Example B.

  Table 3 shows the composition of each composition and the amount thereof. The unit of the number is parts by mass.

  A varnish of the obtained resin composition was applied to the shine surface of a copper foil having a thickness of 18 μm using an applicator so that the thickness of the cured product became 50 μm. Next, drying was performed at 90 ° C. for 30 minutes in a hot-air circulation drying oven. Thereafter, the atmosphere was completely filled with nitrogen using an inert oven, heated to 200 ° C., and cured for 60 minutes. Thereafter, the copper foil was etched to obtain a cured product (cured film).

<< Evaluation >>
With respect to the following items, each composition and a cured film obtained therefrom were evaluated by the following evaluation methods.

<Film forming property>
The varnish from which a cured film was obtained was evaluated as “○”, and the varnish from which a cured film was not obtained was evaluated as “x”. Naturally, the varnish from which a cured film could not be obtained could not be evaluated for the cured film described below.

<Dielectric properties>
The relative permittivity Dk and the dielectric loss tangent Df, which are dielectric properties, were measured according to the following methods.
The cured film was cut into a piece having a length of 80 mm, a width of 45 mm, and a thickness of 50 μm, and a test piece was measured by a SPDR (Split Post Dielectric Resonator) resonator method. As a measuring instrument, a vector type network analyzer E5071C and SPDR resonator manufactured by Keysight Technology GK, and a calculation program used by QWED were used. The conditions were a frequency of 10 GHz and a measurement temperature of 25 ° C.

(Evaluation criteria)
The dielectric properties were evaluated as follows.
Those with a Dk of less than 3.0 were evaluated as “◎”, those with a Dk of less than 3.5 as “○”, and those with a Dk of 3.5 or more as “x”.
Those having a Df of less than 0.003 were evaluated as “◎”, those having a Df of 0.003 or more and less than 0.01 were evaluated as “〇”, and those having a Df of 0.01 or more were evaluated as “x”.

<Self-extinguishing>
The cured film was cut into a length of 200 mm, a width of 15 mm, and a thickness of 50 μm, and a flame of a gas burner was brought into contact with a lower end of the test piece for 5 seconds to measure a burning duration. Specifically, each of the five test pieces was tested twice, and the average time of the combustion duration of a total of ten tests was calculated.

(Evaluation criteria)
"◎" indicates that the average burning duration was less than 20 seconds, "〇" indicates that the burning time was from 20 seconds to 30 seconds, and "x" indicates that the burning time was 30 seconds or more.

<Tensile properties>
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 was measured under the following conditions.
[Measurement condition]
Testing machine: Tensile testing machine EZ-SX (manufactured by Shimadzu Corporation)
Distance between chucks: 50mm
Test speed: 1mm / min
Elongation calculation: (Tension moving distance / Distance between chucks) × 100

(Evaluation criteria)
Those with a tensile elongation at break of 1.0% or more and less than 2.0% were evaluated as "〇", and those with 2.0% or more as "◎".

Claims (7)

Raw phenols (A) satisfying at least the following conditions 1 and 2 or phenols (B) satisfying at least the following conditions 1 and not satisfying the following conditions 2 and satisfying the following conditions 2 without satisfying the following conditions 1 A polyphenylene ether comprising a raw material phenol containing a mixture of phenols (C);
A curable composition characterized by containing silica.
(Condition 1)
Has hydrogen atoms in ortho and para positions (condition 2)
Has a hydrogen atom at the para position and a functional group containing an unsaturated carbon bond   The curable composition according to claim 1, further comprising a thermoplastic elastomer.   The curable composition according to claim 1, further comprising a phosphorus-containing flame retardant.   A dry film or a prepreg obtained by applying the curable composition according to claim 1 to a substrate.   A cured product obtained by curing the curable composition according to claim 1.   A laminate comprising the cured product according to claim 5. An electronic component comprising the cured product according to claim 5.