JP2020143265A - Curable composition, dry film, cured product and electronic component - Google Patents

Abstract

To provide a curable composition which retains low-dielectric characteristics and is soluble in various solvents, and gives a cured film that achieves a low dielectric loss tangent and has fire retardancy.SOLUTION: A curable composition contains a polyphenylene ether obtained from raw-material phenols including a phenol satisfying at least Requirement 1, and a phosphorus compound not compatible with the polyphenylene ether. (Requirement 1) It has hydrogen atoms in the ortho and para positions.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.

Further, in the wiring board material, low dielectric loss tangent for high frequency and improvement of flame retardancy are required.

Therefore, the present invention is a curable composition containing a polyphenylene ether that is soluble in various solvents (organic solvents other than highly toxic organic solvents, such as cyclohexanone), and realizes low dielectric loss tangent and flame retardancy. An object of the present invention is to provide a curable composition suitable for obtaining a cured product to have.

As a result of diligent studies toward the realization of the above object, the present inventors can solve the above problems by using a curable composition containing a polyphenylene ether made from a specific phenol as a raw material and a specific phosphorus compound. We found that, and came to complete the present invention.

That is, the present invention comprises a polyphenylene ether composed of raw material phenols including phenols satisfying at least condition 1.
A phosphorus compound that is incompatible with the polyphenylene ether,
Provided is a curable composition characterized by containing.
(Condition 1)
Has hydrogen atoms at the ortho and para positions

The present invention preferably comprises a polyphenylene ether comprising a raw material phenol containing at least a phenol satisfying condition 1 and having a slope calculated by a conformation plot of less than 0.6.
A phosphorus compound that is incompatible with the polyphenylene ether,
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, while maintaining low dielectric properties, it is also soluble in various solvents (organic solvents other than highly toxic organic solvents, such as cyclohexanone), achieving low dielectric loss tangent and flame retardancy. It is possible to provide a curable composition suitable for obtaining a cured product to have.

Further, according to the present invention, it is also possible to provide a curable composition suitable for obtaining a cured product having low water absorption. Since water has a high dielectric property among substances, the dielectric property of the cured product is greatly deteriorated according to the amount of water absorption. When it has low water absorption, it exhibits stable dielectric properties even in a high humidity environment.
Further, according to the present invention, it is also possible to provide a curable composition suitable for obtaining a cured product having excellent insulation reliability in a high temperature and high humidity environment. Since it is a material that does not cause problems such as poor insulation due to changes in temperature and humidity, it is useful when it is installed in an automobile or used outdoors or in a place where the environment changes drastically.

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 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 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.

It is preferable that the predetermined polyphenylene ether is in the above-mentioned form 2 or in the above-mentioned form 1 in which the phenols (B) and / or the phenols (C) are further contained as essential components.

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 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 20 to 60% 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, its solubility in various solvents is improved.

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).

(Phosphorus compound)
The curable composition of the present invention contains a predetermined phosphorus compound. By containing the phosphorus compound, the flame retardancy of the cured product obtained by curing the composition can be efficiently improved.

The predetermined phosphorus compound means a compound containing one or more phosphorus elements in its molecular structure and having a property of being incompatible with the above-mentioned branched polyphenylene ether.

Examples of the phosphorus compound include a phosphoric acid ester compound, a phosphinic acid compound, and a phosphorus-containing phenol compound.

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

In formula (6), R _{61 to} R ₆₃ each independently have a hydrogen atom and a linear or branched saturated or unsaturated hydrocarbon group having 1 to 15 carbon atoms (preferably 1 to 12). Represent. The hydrocarbon group is preferably an alkyl group, an alkenyl group, an unsubstituted aryl group or an aryl group having an alkyl group or an alkenyl group as a substituent. Typical examples of such a hydrocarbon group include a methyl group, an ethyl group, an octyl group, a vinyl group, an allyl group, a phenyl group, a benzyl group, a trill group and a vinylphenyl group.

Examples of the phosphoric acid ester compound include trimethyl phosphate, triethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, bisphenol A bisdiphenyl phosphate, resorcinol bis-diphenyl phosphate, and 1,3-phenylene-teslakis (2). , 6-Dimethylphenyl phosphate), 1,4-phenylene-tetrakis (2,6-dimethylphenyl phosphate), 4,4'-biphenylene-teslakis (2,6-dimethylphenyl phosphate).

As the phosphinic acid compound, a phosphinic acid metal salt compound represented by the following formula (8) is preferable.

In formula (8), R ₈₁ and R ₈₂ are independently hydrogen atoms or linear or branched saturated or unsaturated hydrocarbon groups. The hydrocarbon group is a linear or branched alkyl group having 1 to 6 carbon atoms, a linear or branched alkenyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or a phenyl group. Groups, benzyl groups or trill groups are preferred. The hydrocarbon group is particularly preferably an alkyl group having 1 to 4 carbon atoms.

In formula (8), M represents an n-valent metal ion. The metal ion M is an ion of at least one metal in the group consisting of Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na and K. It is preferable that at least a part thereof is Al ion.

Examples of the phosphinic acid metal salt compound include aluminum diethylphosphinate.

The phosphinic acid metal salt compound may be surface-treated with a coupling agent so as to have an organic group. By treating the surface with a silane coupling agent, the affinity with an organic solvent can also be improved. Further, if an unsaturated carbon bond such as a vinyl group or a cyclic ether bond such as an epoxy group is present, it becomes possible to crosslink with other components at the time of curing, which leads to improvement of heat resistance and prevention of bleed-out.

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.

Examples of the phosphorus-containing phenol compound include diphenylphosphinyl hydroquinone, diphenylphosphenyl-1,4-dioxynaphthalin, 1,4-cyclooctylenephosphinyl-1,4-phenyldiol, and 1,5-cyclo. Examples include octylenephosphinyl-1,4-phenyldiol.

As the predetermined phosphorus compound, a phosphinic acid metal salt compound having no compatibility with the branched polyphenylene ether is particularly preferable because the phosphorus content per molecule is high.

In the present invention, whether or not the phosphorus compound is compatible with the branched polyphenylene ether is determined based on the following test.

Branched polyphenylene ethers are usually soluble in cyclohexanone. That is, if the phosphorus compound is also soluble in cyclohexanone, it can be said that the mixture of the branched polyphenylene ether and the phosphorus compound is uniformly compatible. Based on this, by confirming the solubility of the phosphorus compound in cyclohexanone, it is determined whether or not the phosphorus compound is compatible with the branched polyphenylene ether.

Specifically, 10 g of a phosphorus compound and 100 g of cyclohexanone are placed in a 200 mL sample bottle, a stirrer is added, the mixture is stirred at 25 ° C. for 10 minutes, and then left at 25 ° C. for 10 minutes. Phosphorus compounds having a solubility of less than 0.1 (10 g / 100 g) are judged to be incompatible with the branched polyphenylene ether, and phosphorus compounds having a solubility of 0.1 (10 g / 100 g) or more are judged to be incompatible with the branched polyphenylene ether. Judged to be compatible with.

The solubility of the phosphorus compound may be less than 0.08 (8 g / 100 g) or less than 0.06 (6 g / 100 g).

When the branched polyphenylene ether and the flame retardant compatible with the branched polyphenylene ether are used in combination, the heat resistance of the obtained cured product may decrease as a result of the branched polyphenylene ether and the flame retardant being excessively compatible with each other. , Was found. It is possible to solve such a problem by using a flame retardant that is incompatible with the branched polyphenylene ether.

The content of the phosphorus compound may be 1 to 10% by mass, 2 to 8% by mass, or 3 to 6% by mass based on the total solid content of the composition. Within the above range, flame retardancy, heat resistance, and dielectric properties of the cured product obtained by curing the composition can be achieved at a high level in a well-balanced manner.

(silica)
The curable composition of the present invention may contain silica. By blending silica into the composition, 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 amount of silica blended may be 50 to 100 parts by mass with respect to 100 parts by mass of polyphenylene ether. Alternatively, the blending amount of silica may be 10 to 30% by mass based on the total solid content of the composition.

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 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 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.

The curable composition may contain known and commonly used raw materials such as resins 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, a flame retardant containing no phosphorus atom, or the like.

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 that is soluble in various solvents, and is suitable for obtaining a cured product having low dielectric loss tangent and self-extinguishing property, and thus has various uses. Can be applied to.

<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 the above-mentioned curable composition to a substrate.

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 Example A: Branched PPE)
<Explanation of Synthesis Example A of Branched Polyphenylene Ether for Examples>
In a 3 L two-necked eggplant flask, 5.3 g of di-μ-hydroxobis [(N, N, N', N'-tetramethylethylenediamine) copper (II)] chloride (Cu / TMEDA) and tetramethyl 5.7 mL of ethylenediamine (TMEDA) was added to sufficiently dissolve the mixture, and oxygen was supplied at 10 ml / min. A raw material solution was prepared by dissolving 10.1 g of raw material phenols о-cresol, 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 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 a branched PPE resin. The slope of the conformation plot was 0.34.

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 PPE resin of Synthesis Example A had a number average molecular weight of 12,700 and a weight average molecular weight of 77,470.

(Synthesis Example B: Non-branched PPE)
<Explanation of Synthesis Example B of Polyphenylene Ether for Comparative Examples>
Synthesis similar to ternary copolymer PPE resin except that a raw material solution prepared by dissolving 13.8 g of 2-allyl-6-methylphenol and 103 g of 2,6-dimethylphenol, which are raw material phenols, in 0.38 L of toluene was used. A non-branched PPE resin was obtained by the method. The slope of the conformation plot was 0.61.

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

<Phosphinate compound>
As the phosphinate compound, "EXOLIT ОP935" manufactured by Clariant Chemicals Co., Ltd. was used. The ОP935 used was a powder having an average particle size of 2.5 μm.

(Preparation of vinyl group-modified phosphinate compound (ОP935))
Cyclohexanone (70% by mass in solid content in cyclohexanone) was added to ОP935, 4 wt% vinylsilane was added to ОP935, and the mixture was treated with a bead mill for 10 minutes to obtain a solution of vinyl group-modified ОP935 (70% by mass in solid content). It was. As the vinylsilane, KBM-1003 manufactured by Shinetsu Silicone Co., Ltd. was used.

(Preparation of amino group-modified phosphinate compound (ОP935))
Cyclohexanone (70% by mass in solid content in cyclohexanone) was added to ОP935, 4 wt% aminosilane was added to ОP935, and the mixture was treated with a bead mill for 10 minutes to obtain a solution of amino group-modified ОP935 (70% by mass in solid content). It was. As the aminosilane, KBM-573 manufactured by Shinetsu Silicone Co., Ltd. was used.

Mixing with various components shown in Examples and Comparative Examples at the ratio (parts by mass) shown in Table 1, stirring for 15 minutes with a stirrer to premix, and then kneading with a 3-roll mill to obtain a thermosetting resin. A composition varnish was prepared. Since all of the phosphorus compounds used have low solubility in cyclohexanone, it can be seen that they are incompatible with the branched PPE of Synthesis Example A.

<Preparation of Resin Composition Varnish of Example 1>
Add 100 parts by mass of cyclohexanone as a solvent to 17.4 parts by mass of branched PPE resin and 11.4 parts by mass of elastomer (Asahi Kasei Co., Ltd .: trade name "H1051"), mix at 40 ° C. for 30 minutes, and stir to complete. It was dissolved. In the PPE resin solution thus obtained, 11.6 parts by mass of TAIC (manufactured by Mitsubishi Chemical Corporation) and spherical silica (manufactured by Admatex Co., Ltd .: trade name "SC2500-SVJ") were added as a cross-linking curing agent to 94.4 parts. By mass, 11.1 g of OP935 (manufactured by Clariant Chemicals, Inc.) was added as a flame retardant, mixed, and then dispersed by a three-roll mill. Finally, 0.58 parts by mass of α, α'-bis (t-butylperoxy-m-isopropyl) benzene (manufactured by Nippon Oil & Fats Co., Ltd .: trade name "Perbutyl P"), which is a curing catalyst, was blended and magnetic. Stirred with a stirrer. In this way, the varnish of the resin composition of Example 1 was obtained.

<Preparation of Resin Composition Varnish of Example 2>
The same operation as in Example 1 was carried out except that the amount of PPE and the amount of TAIC were changed to 14.5 parts by mass to obtain a varnish of the resin composition of Example 2.

<Preparation of resin composition varnish of Example 3>
The same operation as in Example 2 was carried out except that the phosphinate compound was changed to a vinyl group-modified phosphinate compound solution (solid content 70%) of 15.9 parts by mass, and the varnish of the resin composition of Example 3 was carried out. Got

<Preparation of Resin Composition Varnish of Example 4>
The same operation as in Example 2 was carried out except that the phosphinate compound was changed to a 15.9 parts by mass amino group-modified phosphinate compound solution (solid content 70%), and the varnish of the resin composition of Example 4 was carried out. Got

<Preparation of Resin Composition Varnish of Example 5>
The same operation as in Example 2 was carried out except that the phosphorus compound was changed to "PX-202" manufactured by Daihachi Chemical Industry Co., Ltd. to obtain a varnish of the resin composition of Example 5.

<Preparation of Resin Composition Varnish of Example 6>
The same operation as in Example 2 was carried out except that the phosphorus compound was changed to "FCX-210" manufactured by Teijin Limited, to obtain a varnish of the resin composition of Example 6.

<Preparation of resin composition varnish of Comparative Example 1>
The same operation as in Example 2 was performed except that the branched PPE was changed to a conventional PPE (non-branched PPE) to obtain a varnish of the resin composition of Comparative Example 1.

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>
The composition in which cyclohexanone was used as the solvent was evaluated as “◯”, and the composition in which chloroform was used as the solvent was evaluated as “x”. As described above, the conventional PPE resin (non-branched PPE resin) is insoluble in cyclohexanone, but the PPE resin (branched PPE resin) according to the present invention is soluble in cyclohexanone.

(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 became a desired thickness. 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.

<Dielectric property>
The relative permittivity Dk and the dielectric loss tangent Df, which are the dielectric properties, were measured according to the following methods.
According to the above method, a cured film was prepared so as to have a thickness of 50 μm. 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 Dk of less than 3.0 and a Df of less than 0.002 were evaluated as "◯", and those not corresponding to this were evaluated as "x".

<Heat resistance>
According to the above method, a cured film was prepared so as to have a thickness of 50 μm. 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 Corporation). 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 200 ° C. or higher was evaluated as “⊚”, a glass transition temperature (Tg) of 170 ° C. or higher and lower than 200 ° C. was evaluated as “◯”, and a glass transition temperature (Tg) of less than 170 ° C. was evaluated as “x”.

<Water absorption>
It was performed according to IPC-TM-650 2.6.2.1. According to the above method, a cured film was prepared so as to have a thickness of 200 μm, and three sheets of the cured film cut into a length of 50 mm, a width of 50 mm, and a thickness of 200 μm were prepared. The test piece was immersed in a water bath set at 23.5 ° C. for 24 hours, and the water absorption rate (%) was calculated from the weight change of the coating film before and after water absorption.

Those having a water absorption rate of less than 0.07% were evaluated as "◯", and those having a water absorption rate of 0.07% or more were evaluated as "x".

<Flame retardant>
This was performed according to Test for Flammability of Plastic Materials-UL94 of Underwriters Laboratories. According to the above method, a cured film was prepared so as to have a thickness of 200 μm, and 10 sheets of the cured film cut into a length of 125 mm, a width of 12.5 mm and a thickness of 200 μm were prepared. Each of the five test pieces was burned twice (10 times in total) and evaluated.

Those with a flammability classification of V-0 were evaluated as "⊚", those with V-1 were evaluated as "○", and those not corresponding to these were evaluated as "x".

<BHAST resistance>
After the BT substrate on which the comb-shaped electrode (line / space = 20 μm / 15 μm) was formed was chemically polished, the resin varnish was applied using a lip coater so that the thickness of the cured product was 40 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 then cured for 60 minutes to prepare an evaluation substrate. The evaluation substrate was placed in a high-temperature and high-humidity tank in an atmosphere of a temperature of 130 ° C. and a humidity of 85%, charged with a voltage of 5.5 V, and a HAST test in the tank was performed. The insulation resistance value in the tank after 300 hours of the cured film of the resin layer was evaluated according to the following criteria.

Tank insulation resistance at 300 hours elapsed The symbol "" of not less than 10 ⁷ Omega, were those less than 10 ⁷ Omega was evaluated as "×".

Claims (6)

Polyphenylene ether composed of raw material phenols including phenols satisfying at least condition 1 and
A phosphorus compound that is incompatible with the polyphenylene ether,
A curable composition comprising.
(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 the curable composition according to claim 1 or 2 to a substrate. A cured product obtained by curing the curable composition according to claim 1 or 2. A laminated board comprising the cured product according to claim 4. An electronic component having the cured product according to claim 4.