JP7339801B2 - Curable compositions, dry films, cured products and electronic components - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act (1) The Society of Polymer Science, Japan, Proceedings of the Society of Polymer Science, Vol. 68, No. 1 [2019] Issued May 14, 2019 May 30, 2019 The 68th SPSJ Annual Meeting

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

With the spread of high-capacity high-speed communications represented by fifth-generation communication systems (5G) and millimeter-wave radars for automobile ADAS (advanced driving systems), the signals of communication devices have become increasingly high-frequency.

However, when conventional epoxy resins are used as wiring board materials, the dielectric constant (Dk) and dielectric loss tangent (Df) are not sufficiently low. Problems such as signal attenuation and heat generation occurred. For this reason, polyphenylene ether, which has excellent low dielectric properties, has been used. However, since polyphenylene ether is a thermoplastic resin, it has a problem of heat resistance.

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

J. Nunoshige, H. Akahoshi, Y. Shibasaki, M. Ueda, J. Polym. Sci. Part A: Polym. Chem. 2008, 46, 5278-5282.

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

Furthermore, wiring board materials are required to have a low dielectric loss tangent and an improvement in flame retardancy in order to cope with high frequencies.

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

The present inventors have made intensive studies to achieve the above objects, and found that the above problems can be solved by using a curable composition containing polyphenylene ether made from a specific phenol as a raw material and a specific phosphorus compound. We have found that and completed the present invention.

That is, the present invention provides a polyphenylene ether composed of raw material phenols containing phenols that satisfy at least Condition 1,
a phosphorus compound incompatible with the polyphenylene ether;
To provide a curable composition characterized by containing
(Condition 1)
have hydrogen atoms in the ortho and para positions

The present invention preferably comprises a polyphenylene ether comprising raw material phenols containing phenols that satisfy at least Condition 1 and having a slope of less than 0.6 as calculated by a conformation plot,
a phosphorus compound incompatible with the polyphenylene ether;
To provide a curable composition characterized by containing
(Condition 1)
have hydrogen atoms in the ortho and para positions

Part or all of the polyphenylene ether is
Phenols (A) that meet at least the following conditions 1 and 2 below, or phenols (B) that meet at least the following conditions 1 and do not meet the following conditions 2 and phenols that meet the following conditions 1 but do not meet the following conditions 2 It may also be a polyphenylene ether consisting of raw material phenols including mixtures of class (C).
(Condition 1)
Having hydrogen atoms at the ortho and para positions (Condition 2)
Having a hydrogen atom at the para position and having a functional group containing an unsaturated carbon bond

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.

Moreover, this invention provides the laminated board characterized by including the said hardened|cured material.

Moreover, this invention provides the electronic component characterized by having the said hardened|cured material.

According to the present invention, while maintaining low dielectric properties, it is soluble in various solvents (organic solvents other than highly toxic organic solvents, such as cyclohexanone), realizes low dielectric loss tangent, and exhibits flame retardancy. It is possible to provide a curable composition suitable for obtaining a cured product having

Furthermore, 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 high dielectric properties among substances, the dielectric properties of the cured product deteriorate greatly depending on the amount of water absorption. With low water absorption, it exhibits stable dielectric properties even in high-humidity environments.
Furthermore, 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 insulation failure due to changes in temperature and humidity, it is useful when it is installed in automobiles or used in places where the environment changes drastically, such as outdoors.

In addition, when isomers exist in the described compounds, all possible isomers can be used in the present invention unless otherwise specified.

In the present invention, unless otherwise specified, the term "unsaturated carbon bond" refers to an ethylenic or acetylenic multiple bond (double bond or triple bond) between carbon atoms.

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

In the present invention, simply expressing "ortho position" or the like means "at least one of the ortho positions" or the like. Therefore, as long as there is no particular contradiction, the simple expression "ortho position" may be interpreted as indicating either one of the ortho positions or both of the ortho positions.

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

The curable composition (also simply referred to as composition) of the present invention is described below.

(polyphenylene ether)
The curable compositions of the present invention contain certain polyphenylene ethers. As will be described later, the predetermined polyphenylene ether is a polyphenylene ether having a branched structure. Therefore, a certain 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.

Phenols satisfying condition 1 {for example, phenols (A) and phenols (B) described later} have a hydrogen atom at the ortho position. In addition, since an ether bond can be formed at the ortho position as well, it is possible to form a branched chain structure.

Phenols that do not satisfy condition 1 (for example, phenols (C) and phenols (D) described later) form ether bonds at the ipso and para positions when oxidatively polymerized, resulting in linear being polymerized.

Thus, a part of the structure of the predetermined polyphenylene ether is branched by the benzene ring ether-bonded at at least three positions of the ipso-, ortho- and para-positions. A polyphenylene ether is, for example, considered to be a polyphenylene ether compound having at least a branched structure as represented by formula (i) in its 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 within a range that does not impair the effects of the present invention.

Other phenols include, for example, 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 include phenols (C) and phenols (D) as raw material phenols.

A particularly preferred predetermined polyphenylene ether is a phenol (A) that satisfies at least the following condition 1 and the following condition 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 First, it is a polyphenylene ether composed of raw material phenols containing a mixture of phenols (C) that satisfies condition 2 below. Preferred polyphenylene ethers have unsaturated carbon bonds in the side chains, as described below. Upon curing, the unsaturated carbon bonds allow three-dimensional cross-linking. As a result, it has excellent heat resistance and solvent resistance.

Specifically, the polyphenylene ether is
(Mode 1) At least, phenols that satisfy both the following conditions 1 and 2 below (A) Raw material phenols containing as essential components, or
(Mode 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 satisfies the following condition 1 but does not satisfy the following condition 2 as an essential component ,
is obtained by oxidative polymerization.
(Condition 1)
Having hydrogen atoms at the ortho and para positions (Condition 2)
Having a hydrogen atom at the para position and having a functional group containing an unsaturated carbon bond

Phenols satisfying Condition 2 {eg, phenols (A) and phenols (C)} have at least a hydrocarbon group containing an unsaturated carbon bond. Therefore, a polyphenylene ether synthesized from phenols satisfying condition 2 as a raw material has a hydrocarbon group containing an unsaturated carbon bond as a functional group, and thus has crosslinkability.

Thus, a preferred predetermined polyphenylene ether has a part of its structure branched by a benzene ring ether-bonded at at least three positions of ipso-, ortho- and para-positions. Polyphenylene ether is, for example, a polyphenylene ether having at least a branched structure as represented by 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 formula (i) above is a hydrocarbon group having an unsaturated carbon bond.

Next, the form 1 may be a form further containing phenols (B) and/or phenols (C) as raw material phenols. Moreover, the said form 2 may be the form which further contains phenols (A) as raw material phenols.

The predetermined polyphenylene ether is preferably in form 2 above, or in form 1 containing phenols (B) and/or phenols (C) as further essential components.

Moreover, the raw material phenols may contain other phenols within a range that does not impair the effects of the present invention.

Other phenols include, for example, phenols (D) that are phenols that have a hydrogen atom at the para position, do not have a hydrogen atom at the ortho position, and do not have a functional group containing an unsaturated carbon bond. be done.

In both of the above-mentioned form 1 and the above-mentioned form 2, it is preferable to further contain phenols (D) as raw material phenols in order to increase the molecular weight of the polyphenylene ether.

It is most preferable that the polyphenylene ether in the form 2 above further contains phenols (D) as raw material phenols.

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

Phenols (A) to (D) are described in more detail below.

Phenols (A) are phenols that satisfy both conditions 1 and 2 as described above, that is, phenols having hydrogen atoms 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 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. From the viewpoint of facilitating polymerization during oxidative polymerization, the hydrocarbon group preferably has 1 to 12 carbon atoms.

Phenols (a) represented by formula (1) include o-vinylphenol, m-vinylphenol, o-allylphenol, m-allylphenol, 3-vinyl-6-methylphenol, 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. Only one kind of the phenols represented by the formula (1) may be used, or two or more kinds thereof may be used.

Phenols (B) are, as described above, phenols that satisfy condition 1 but do not satisfy condition 2, i.e., have hydrogen atoms at the ortho and para positions and do not have a functional group containing an unsaturated carbon bond. Phenols, preferably phenols (b) represented by the following formula (2).

In 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. From the viewpoint of facilitating polymerization during oxidative polymerization, the hydrocarbon group preferably has 1 to 12 carbon atoms.

Phenols (b) represented by 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. Only one kind of phenols represented by the formula (2) may be used, or two or more kinds thereof may be used.

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

In 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. From the viewpoint of facilitating polymerization during oxidative polymerization, the hydrocarbon group preferably has 1 to 12 carbon atoms.

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

Phenols (D) are, as described above, 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. Phenols (d) represented by the formula (4).

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

Phenols (d) represented by 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. Only one kind of phenols represented by the formula (4) may be used, or two or more kinds thereof may be used.

Here, in the present invention, the hydrocarbon group includes an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, an alkynyl group and the like, preferably an alkyl group, an aryl group and an alkenyl group. Examples of hydrocarbon groups having unsaturated carbon bonds include alkenyl groups and alkynyl groups. These hydrocarbon groups may be linear or branched.

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

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

Phenols satisfying condition 2 may not be used, but when used, the ratio of phenols satisfying condition 2 to the total of raw material phenols is preferably 0.5 to 99 mol%, preferably 1 to 99 mol%. is more preferable.

The polyphenylene ether obtained by subjecting the raw material phenols described above to oxidation polymerization 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, even more 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 1.5-20.

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

One gram of a given polyphenylene ether is soluble in preferably 100 grams of cyclohexanone (more preferably 100 grams of cyclohexanone, DMF and PMA) at 25°C. The expression 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. More preferably, the predetermined polyphenylene ether is soluble in 1 g or more of 100 g of cyclohexanone at 25°C.

The predetermined polyphenylene ether can be produced by applying a conventionally known polyphenylene ether synthesis method (polymerization conditions, presence or absence of catalyst, type of catalyst, etc.), except for using specific phenols as raw materials. be.

The content of the predetermined polyphenylene ether is the balance after 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 components constituting the composition other than the solvent (especially organic solvent), or the mass or volume thereof.

Certain polyphenylene ethers have branched structures that improve their solubility in various solvents.

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

<Analysis procedure>
After preparing chloroform solutions of polyphenylene ether at intervals of 0.1, 0.15, 0.2, and 0.25 mg/mL, a graph of refractive index difference and concentration was drawn while feeding the solution at 0.5 mL/min. , calculate the refractive index increment dn/dc 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 is obtained by the least-squares method from the logarithmic graph (conformation plot) of the molecular weight and the radius of gyration, and the slope thereof is calculated.

<Measurement conditions>
Device name: HLC8320GPC
Mobile phase: Chloroform Column: TOSOH TSKguardcolumnHHR-H
+TSKgelGMHHR-H (2 pieces)
+TSKgelG2500HHR
Flow rate: 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: 1.5mg/mL
STD solvent: Same as mobile phase. Dissolve 15 mg of sample in 10 mL of mobile phase Analysis time: 100 min

Among resins having the same absolute molecular weight, the more branched the polymer chain, the smaller the distance (radius of rotation) from the center of gravity to each segment. 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, a smaller slope calculated from the conformation plot indicates more branching of the polyphenylene ether, and a larger slope indicates less branching of the polyphenylene ether.

In polyphenylene ether, the slope 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. If the slope is within this range, the polyphenylene ether is considered to have sufficient branching. Although the lower limit of the slope is not particularly limited, it 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, catalyst amount, stirring speed, reaction time, oxygen supply amount, and solvent amount during 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 supplied, and/or decreasing the amount of solvent, the slope of the conformation plot is reduced. tend to be lower (the polyphenylene ether tends to branch more easily).

(Phosphorus compound)
The curable compositions of the present invention contain certain phosphorus compounds. 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 branched polyphenylene ether described above.

Phosphorus compounds include, for example, phosphate ester compounds, phosphinic acid compounds, and phosphorus-containing phenol compounds.

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

In formula (6), R ₆₁ to R ₆₃ each independently represent a hydrogen atom or a linear or branched saturated or unsaturated hydrocarbon group having 1 to 15 (preferably 1 to 12) carbon atoms. 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 alkenyl group as a substituent. Such hydrocarbon groups typically include methyl, ethyl, octyl, vinyl, allyl, phenyl, benzyl, tolyl, and vinylphenyl groups.

Examples of phosphoric acid ester compounds include trimethyl phosphate, triethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, bisphenol A bisdiphenyl phosphate, resorcinol bis-diphenyl phosphate, 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, phenyl , benzyl or tolyl 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 selected from the group consisting of Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe, Zr, Ce, Bi, Sr, Mn, Li, Na and K; At least part of it is preferably Al ions.

Examples of metal phosphinate compounds include aluminum diethylphosphinate.

The metal phosphinate compound may be surface-treated with a coupling agent so as to have an organic group. Affinity with organic solvents can also be improved by treating the surface with a silane coupling agent. Also, if it has an unsaturated carbon bond such as a vinyl group or a cyclic ether bond such as an epoxy group, it becomes possible to crosslink with other components during curing, which leads to improvement in heat resistance and prevention of bleeding out.

Examples of silane coupling agents that can be used include epoxysilane coupling agents, mercaptosilane coupling agents, and vinylsilane coupling agents. Examples of epoxysilane coupling agents that can be used include γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropylmethyldimethoxysilane. As a mercaptosilane coupling agent, for example, γ-mercaptopropyltriethoxysilane can be used. As the vinylsilane coupling agent, for example, vinyltriethoxysilane can be used.

Examples of phosphorus-containing phenol compounds include diphenylphosphinylhydroquinone, diphenylphosphenyl-1,4-dioxynaphthalene, 1,4-cyclooctylenephosphinyl-1,4-phenyldiol, 1,5-cyclo and 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 of its high phosphorus content per molecule.

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

Branched polyphenylene ethers are generally soluble in cyclohexanone. In other words, 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, it is determined whether or not the phosphorus compound is compatible with the branched polyphenylene ether by checking the solubility of the phosphorus compound in cyclohexanone.

Specifically, 10 g of a phosphorus compound and 100 g of cyclohexanone are placed in a 200 mL sample bottle, a stirring bar is added, and the mixture is stirred at 25° C. for 10 minutes, and then allowed to stand at 25° C. for 10 minutes. For phosphorus compounds with a solubility of less than 0.1 (10 g / 100 g), it is judged to be incompatible with branched polyphenylene ether, and for phosphorus compounds with a solubility of 0.1 (10 g / 100 g) or more, branched polyphenylene ether It is 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 a branched polyphenylene ether and a flame retardant compatible with the branched polyphenylene ether are used in combination, the branched polyphenylene ether and the flame retardant are too compatible, and as a result, the heat resistance of the resulting cured product may decrease. problem was found. It is possible to solve such problems 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 formability of the composition can be improved. Furthermore, flame retardancy can be imparted to the resulting 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 diameter can be obtained as the median diameter (d50, volume basis) based on the cumulative distribution from the particle size distribution measured by the laser diffraction/scattering method using a commercially available laser diffraction/scattering particle size distribution analyzer. can.

Silicas with different average particle sizes can be used together. From the viewpoint of achieving a high filling of silica, for example, silica having an average particle size of 1 μm or more may be used in combination with nano-order fine silica having an average particle size of less than 1 μm.

Silica may be surface-treated with a coupling agent. Dispersibility with polyphenylene ether can be improved by treating the surface with a silane coupling agent. In addition, affinity with organic solvents can also be improved.

Examples of silane coupling agents that can be used include epoxysilane coupling agents, mercaptosilane coupling agents, and vinylsilane coupling agents. Examples of epoxysilane coupling agents that can be used include γ-glycidoxypropyltrimethoxysilane and γ-glycidoxypropylmethyldimethoxysilane. As a mercaptosilane coupling agent, for example, γ-mercaptopropyltriethoxysilane can be used. As the vinylsilane coupling agent, for example, vinyltriethoxysilane 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 compounded may be 50 to 100 parts by mass with respect to 100 parts by mass of polyphenylene ether. Alternatively, the silica content may be 10 to 30% by mass based on the total solid content of the composition.

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.

A peroxide has the effect of opening the unsaturated carbon bonds contained in the preferred polyphenylene ether and promoting the cross-linking reaction.

Peroxides include methyl ethyl ketone peroxide, methyl acetoacetate peroxide, acetylacetoperoxide, 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-dimethyl-2,5-di(t-butylperoxy)-3-butene, acetyl peroxide, octanoyl peroxide, lauroyl peroxide, benzoyl peroxide, m- toluyl peroxide, diisopropyl peroxydicarbonate, t-butylene peroxybenzoate, di-t-butyl peroxide, t-butylperoxyisopropyl monocarbonate, α,α'-bis(t-butylperoxy-m-isopropyl) benzene, and the like. Only one type of peroxide may be used, or two or more types may be used.

Among these, peroxides having a 1-minute half-life temperature of 130° C. to 180° C. are desirable from the viewpoint of ease of handling and reactivity. Since such a peroxide has a relatively high reaction initiation temperature, it is difficult to accelerate curing at a time such as drying when curing is not required, does not reduce the storage stability of the polyphenylene ether resin composition, and is volatile It does not volatilize during drying or storage due to its low volatility, and has good stability.

The amount of peroxide added is preferably 0.01 to 20 parts by mass, preferably 0.05 to 10 parts by mass, based on 100 parts by mass of the solid content of the curable composition, in terms of the total amount of peroxides. is more preferable, and 0.1 to 10 parts by mass is particularly preferable. By setting the total amount of the peroxide within this range, it is possible to prevent deterioration of film quality when formed into a coating film, while ensuring sufficient effects at low temperatures.

In addition, if necessary, azo compounds such as azobisisobutyronitrile and azobisisovaleronitrile and radical initiators such as dicumyl and 2,3-diphenylbutane may be contained.

The crosslinkable curing agent reacts with unsaturated carbon bonds contained in the preferred polyphenylene ether to form three-dimensional crosslinks.

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

A (meth)acrylate compound (methacrylate compound and acrylate compound) may also be used as the cross-linking curing agent. In particular, it is preferable to use tri- to penta-functional (meth)acrylate compounds. Trimethylolpropane trimethacrylate and the like can be used as tri- to penta-functional methacrylate compounds, while trimethylolpropane triacrylate and the like can be used as tri- to penta-functional acrylate compounds. Heat resistance can be enhanced by using these cross-linking agents. Only one type of cross-linking curing agent may be used, or two or more types 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 cross-linking curing agent.

The mixing ratio of the polyphenylene ether and the crosslinking type curing agent is preferably 20:80 to 90:10, more preferably 30:70 to 90:10, by mass. When the 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, adipine hydrazine compounds such as acid dihydrazide and sebacic acid dihydrazide;
Guanamine, 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 adducts and 2,4-diamino-6-methacryloyloxyethyl-S-triazine/isocyanuric acid adducts;
phosphorus compounds such as triphenylphosphine;

Among these, triphenylphosphine is preferable because it can prevent yellowing 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 in which polyphenylene ether is dissolved in a solvent (solvent). Since the polyphenylene ether of the present invention has higher solubility in solvents than conventional polyphenylene ethers, a wide range of solvents can be used depending on the application 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, toluene, N,N-dimethylformamide (DMF), and N-methyl-2-pyrrolidone. (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. Only one solvent may be used, or two or more solvents may be used.

The content of the solvent in the curable composition is not particularly limited, and can be appropriately adjusted depending on the application 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, or a flame retardant containing no phosphorus atom.

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 soluble in various solvents, and is suitable for obtaining a cured product having a low dielectric loss tangent and self-extinguishing properties. can be applied to

<Cured product>
A 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 changed as appropriate according to the composition of the curable composition. As an example, after performing the step of applying the curable composition onto the substrate as described above (for example, coating with an applicator or the like), a drying step of drying the curable composition is performed as necessary. Then, a thermosetting step of thermally cross-linking the polyphenylene ether by heating (for example, heating with an inert gas oven, hot plate, vacuum oven, vacuum press, etc.) may be performed. The implementation conditions (for example, coating thickness, drying temperature and time, heating temperature and time, etc.) in each step may be appropriately changed according to the composition, application, etc. of the curable composition.

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

Here, the substrate includes metal foil such as copper foil, film such as polyimide film, polyester film and polyethylene naphthalate (PEN) film, glass cloth, fiber such as aramid fiber.

A dry film is obtained, for example, by coating a curable composition on a polyethylene terephthalate film, drying it, and laminating a polypropylene film as necessary.

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

<Laminate>
In the present invention, a laminate can be produced using the prepreg described above.

Specifically, one or more layers of the prepreg of the present invention are stacked, metal foils such as copper foils are stacked on both sides or one side of the prepreg, and the laminate is heat-pressed to form an integrated laminate. Laminates having metal foil on both sides or metal foil on one side can be made.

<Electronic parts>
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 includes millimeter-wave radar for large-capacity high-speed communication and automobile ADAS (advanced driving system) typified by the fifth generation communication system (5G). .

The curable composition of the present invention will be described in more detail by way of Examples and Comparative Examples, but the present invention is in no way limited to these.

(Synthesis Example A: Branched PPE)
<Description of Synthesis Example A of Branched Polyphenylene Ether for Examples>
In a 3 L two-necked eggplant flask, 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 and dissolved sufficiently, and oxygen was supplied at 10 ml/min. A raw material solution was prepared by dissolving 10.1 g of o-cresol, 13.8 g of 2-allyl-6-methylphenol and 91.1 g of 2,6-dimethylphenol as raw material phenols in 1.5 L of toluene. This raw material solution was added dropwise to the flask and reacted at 40° C. for 6 hours while stirring at a rotational speed of 600 rpm. After completion of the reaction, the precipitate was reprecipitated with a mixed solution of 20 L of methanol and 22 mL of concentrated hydrochloric acid, filtered and dried at 80° C. for 24 hours to obtain a branched PPE resin. Also, the slope of the conformation plot was 0.34.

The PPE resin of Synthesis A was soluble in various organic solvents such as cyclohexanone, N,N-dimethylformamide (DMF), 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: Unbranched PPE)
<Description of Synthesis Example B of Polyphenylene Ether for Comparative Example>
The same synthesis as for the terpolymerized 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. An unbranched PPE resin was obtained in the process. Also, the slope of the conformation plot was 0.61.

The PPE resin of Synthesis B was not soluble in cyclohexanone but was 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 OP935" manufactured by Clariant Chemicals Co., Ltd. was used. The OP935 used was a powder with an average particle size of 2.5 μm.

(Preparation of vinyl group-modified phosphinate compound (OP935))
Cyclohexanone (solid content: 70% by mass in cyclohexanone) was added to OP935, 4% by weight of vinylsilane was added to OP935, and treated with a bead mill for 10 minutes to obtain a solution of vinyl group-modified OP935 (solid content: 70% by mass). Ta. As the vinyl silane, KBM-1003 manufactured by Shin-Etsu Silicone Co., Ltd. was used.

(Preparation of amino group-modified phosphinate compound (OP935))
Cyclohexanone (solid content: 70% by mass in cyclohexanone) was added to OP935, 4% by weight of aminosilane was added to OP935, and treated with a bead mill for 10 minutes to obtain a solution of amino group-modified OP935 (solid content: 70% by mass). Ta. As the aminosilane, KBM-573 manufactured by Shin-Etsu Silicone Co., Ltd. was used.

Various components shown in Examples and Comparative Examples were blended in the proportions (parts by mass) shown in Table 1, premixed by stirring with a stirrer for 15 minutes, and then kneaded with a three-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>
To 17.4 parts by mass of a branched PPE resin and 11.4 parts by mass of an elastomer (Asahi Kasei Co., Ltd., trade name "H1051"), 100 parts by mass of cyclohexanone was added as a solvent, and the mixture was mixed at 40°C for 30 minutes and stirred until complete. Dissolved. To the PPE resin solution thus obtained, 11.6 parts by mass of TAIC (manufactured by Mitsubishi Chemical Corporation) as a cross-linking curing agent and 94.4 parts of spherical silica (manufactured by Admatechs Co., Ltd.: trade name "SC2500-SVJ") were added. Part by mass, 11.1 g of OP935 (manufactured by Clariant Chemicals) as a flame retardant was added and mixed, followed by dispersion with a three-roll mill. Finally, 0.58 parts by mass of α,α'-bis(t-butylperoxy-m-isopropyl)benzene (manufactured by NOF Co., Ltd.: product name "Perbutyl P"), which is a curing catalyst, is blended to form a magnetic Stirred with a stirrer. Thus, a varnish of the resin composition of Example 1 was obtained.

<Preparation of resin composition varnish of Example 2>
A varnish of the resin composition of Example 2 was obtained in the same manner as in Example 1 except that the amount of PPE and the amount of TAIC were changed to 14.5 parts by mass.

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

<Preparation of resin composition varnish of Example 4>
The varnish of the resin composition of Example 4 was prepared in the same manner as in Example 2, except that the phosphinate compound was changed to 15.9 parts by mass of an amino group-modified phosphinate compound solution (solid content: 70%). got

<Preparation of resin composition varnish of Example 5>
A varnish of the resin composition of Example 5 was obtained in the same manner as in Example 2 except that the phosphorus compound was changed to "PX-202" manufactured by Daihachi Chemical Industry Co., Ltd.

<Preparation of resin composition varnish of Example 6>
A varnish of the resin composition of Example 6 was obtained in the same manner as in Example 2 except that the phosphorus compound was changed to "FCX-210" manufactured by Teijin Limited.

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

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

<Environmental response>
A composition using cyclohexanone as a solvent was evaluated as "good", and a composition using chloroform as a solvent was evaluated as "poor". As mentioned above, conventional PPE resins (unbranched PPE resins) are not soluble in cyclohexanone, but the PPE resins of the present invention (branched PPE resins) are soluble in cyclohexanone.

(Preparation of cured film)
The varnish of the obtained resin composition was applied to the shiny side of a copper foil having a thickness of 18 μm with an applicator so that the cured product had a desired thickness. Next, it was dried at 90° C. for 30 minutes in a hot air circulation drying oven. Thereafter, an inert oven was used to completely fill nitrogen, and the temperature was raised to 200° C., followed by curing for 60 minutes. After that, the copper foil was removed by etching to obtain a cured film.

<Dielectric properties>
The relative dielectric constant Dk and dielectric loss tangent Df, which are dielectric properties, were measured according to the following methods.
A cured film having a thickness of 50 μm was produced according to the method described above. 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. A vector-type network analyzer E5071C and an SPDR resonator manufactured by Keysight Technologies LLC were used as measuring instruments, and a calculation program manufactured by QWED was used. The conditions were a frequency of 10 GHz and a measurement temperature of 25°C.

As a dielectric property evaluation, a sample having a Dk of less than 3.0 and a Df of less than 0.002 was evaluated as "◯", and a sample that did not correspond to this was evaluated as "X".

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

A sample having a glass transition temperature (Tg) of 200°C or higher was evaluated as "⊚", a sample having a glass transition temperature (Tg) of 170°C or more and less than 200°C was evaluated as "◯", and a sample having a glass transition temperature (Tg) of less than 170°C was evaluated as "x".

<Water absorption>
It was carried out according to IPC-TM-650 2.6.2.1. According to the method described above, a cured film having a thickness of 200 μm was produced, and the cured film was cut into 50 mm long, 50 mm wide, and 200 μm thick test pieces to prepare three specimens. The test piece was immersed in a water bath set at 23.5° C. for 24 hours, and the water absorption (%) was calculated from the weight change of the coating film before and after water absorption.

A sample with a water absorption rate of less than 0.07% was evaluated as "◯", and a sample with a water absorption rate of 0.07% or more was evaluated as "X".

<Flame Retardant>
It was carried out according to Underwriters Laboratories' Test for Flammability of Plastic Materials-UL94. According to the method described above, a cured film having a thickness of 200 μm was prepared, and 10 specimens were prepared by cutting the cured film into a length of 125 mm, a width of 12.5 mm, and a thickness of 200 μm. Each of the five test pieces was subjected to the combustion test twice (10 times in total) and evaluated.

Those with a flammability classification of V-0 were evaluated as "⊚", those with V-1 as "◯", and those that did not fall under these categories as "x".

<BHAST resistance>
After chemically polishing a BT substrate on which comb-type electrodes (line/space=20 μm/15 μm) were formed, the resin varnish was applied using a lip coater so that the thickness of the cured product would be 40 μm. Next, it was dried at 90° C. for 30 minutes in a hot air circulation drying oven. Thereafter, an inert oven was used to completely fill nitrogen, and the temperature was raised to 200° C., followed by curing for 60 minutes to prepare an evaluation substrate. The evaluation board was placed in a high-temperature and high-humidity chamber under an atmosphere of 130° C. and 85% humidity, and charged with a voltage of 5.5 V to perform an in-chamber HAST test. The in-tank insulation resistance value of the cured film of the resin layer after 300 hours was evaluated according to the following criteria.

When the in-tank insulation resistance value after 300 hours had passed was 10 ⁷ Ω or more, it was evaluated as “◯”, and when it was less than 10 ⁷ Ω, it was evaluated as “X”.

Claims (5)

A polyphenylene ether made of raw material phenols containing phenols that satisfy at least condition 1;
a phosphorus compound incompatible with the polyphenylene ether;
contains
Part or all of the polyphenylene ether is
Phenols (A) that meet at least the following conditions 1 and 2 below, or phenols (B) that meet at least the following conditions 1 and do not meet the following conditions 2 and phenols that meet the following conditions 1 but do not meet the following conditions 2 It is a polyphenylene ether composed of raw material phenols containing a mixture of class (C)
A curable composition characterized by:
(Condition 1)
have hydrogen atoms in the ortho and para positions
(Condition 2)
Having a hydrogen atom at the para position and having a hydrocarbon group containing an unsaturated carbon bond A dry film or 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 3 . An electronic component comprising the cured product according to claim 3 .