JP7375144B2 - Polyphenylene ether, curable compositions containing polyphenylene ether, dry films, prepregs, cured products, laminates, and electronic components - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act (1) Public Interest Incorporated Association, Society of Polymer Science, Proceedings of the Society of Polymer Science, Volume 68, No. 1 [2019] Published on May 14, 2020 (2) Date of the conference: Reiwa 1 May 30th, 68th Annual Meeting of the Society of Polymer Science and Technology

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

With the spread of high-capacity, high-speed communications typified by fifth-generation communication systems (5G) and millimeter-wave radar for automotive ADAS (Advanced Driving Systems), the frequency of communications equipment signals has progressed toward higher frequencies.

However, when using epoxy resin as a wiring board material, the dielectric constant (Dk) and dielectric loss tangent (Df) are not low enough, so as the frequency increases, the transmission loss due to dielectric loss increases, and the signal Problems such as attenuation and heat generation were occurring. Therefore, polyphenylene ether, which has excellent low dielectric properties, has been used, but since polyphenylene ether is a thermoplastic resin, it has a problem with heat resistance.

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

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

However, the solvents in which polyphenylene ether can be dissolved are 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 has been a problem in that it is difficult to handle the resin varnish and control exposure to solvents in the process of forming and curing the resin varnish into a coating film, such as in wiring board applications.

Therefore, an object of the present invention is to provide a polyphenylene ether that maintains low dielectric properties and is soluble in various solvents (organic solvents other than highly toxic organic solvents, such as cyclohexanone).

Furthermore, a second object of the present invention is to provide a thermosetting polyphenylene ether having the above properties.

As a result of intensive studies aimed at achieving the above object, the present inventors discovered that the above problem could be solved by using specific phenols as raw materials for polyphenylene ether, and thus completed the present invention. Ta.

The present invention (1) is
The polyphenylene ether is obtained from raw material phenols containing phenols that satisfy at least Condition 1, and is characterized by having a slope calculated by a conformation plot of less than 0.6.

The present invention (1A) is
In the invention (1),
As the raw material phenols,
Contains at least a phenol (A) that satisfies both Condition 1 and Condition 2 below, or
It may contain at least phenols (B) which satisfy the following condition 1 but do not satisfy the following condition 2, and phenols (C) which do not satisfy the following condition 1 but satisfy the following condition 2.

Moreover, the present invention (2)
A method for producing polyphenylene ether, comprising a step of oxidatively polymerizing raw material phenols,
As the raw material phenols,
Contains at least a phenol (A) that satisfies both Condition 1 and Condition 2 below, or
A method for producing polyphenylene ether, comprising at least a phenol (B) that satisfies the following condition 1 but does not satisfy the following condition 2, and a phenol (C) that does not satisfy the following condition 1 but satisfies the following condition 2. be.
(Condition 1)
Has hydrogen atoms at the ortho and para positions (condition 2)
Has a hydrogen atom in the para position and a functional group containing an unsaturated carbon bond

The present invention (2A) is a polyphenylene ether obtained by the production method of the invention (2).

The phenol (A) may be a phenol (a) represented by the following 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 phenol (B) may be a phenol (b) represented by the following 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 phenol (C) may be a phenol (c) represented by the following 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, R ₇ to R ₁₀ At least one of them is a hydrocarbon group having an unsaturated carbon bond.)

The ratio of the phenols satisfying the above condition 1 to the total of the raw material phenols may be 1 to 50 mol%.

The polyphenylene ether may be soluble in 1 g at 25° C. in 100 g of cyclohexanone.

The present invention (3) is a curable composition containing the polyphenylene ether and a peroxide.

The curable composition may be a curable composition containing a crosslinked curing agent.

The present invention (4) is a dry film or prepreg obtained by applying the curable composition to a base material.

The present invention (5) is a cured product obtained by curing the curable composition.

The present invention (6) is a laminate containing the cured product.

The present invention (7) is an electronic component having the cured product.

According to the present invention, it is possible to provide polyphenylene ether that is soluble in various solvents while maintaining low dielectric properties.

Furthermore, according to the present invention, it is also possible to provide a thermosetting polyphenylene ether having the above properties.

FIG. 1 shows the results of NMR analysis of polyphenylene ether.

Hereinafter, the method for producing polyphenylene ether of the present invention and the polyphenylene ether obtained by the method will be specifically explained, but the present invention is not limited thereto.

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

Furthermore, in the present invention, an "unsaturated carbon bond" refers to an ethylenic or acetylenic carbon-carbon multiple bond (double bond or triple bond) unless otherwise specified.

In the present invention, when describing raw material phenols, when expressed as "ortho position", "para position", etc., unless otherwise specified, the position of the phenolic hydroxyl group is the standard (ipso position).

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, simply "ortho position" may be interpreted as indicating either ortho position, or both ortho positions.

Each step of the polyphenylene ether production method (synthesis method) of the present invention and the polyphenylene ether obtained by the production method will be described below.

<<<Process>>>
In the method for producing polyphenylene ether of the present invention, specific phenols may be included as a raw material during oxidative polymerization, and other than that, conventionally known methods for producing polyphenylene ether can be applied.

In addition, in the method for producing polyphenylene ether of the present invention, phenols that are used as raw materials and can be the constituent units of polyphenylene ether are collectively referred to as "raw material phenols."

The polyphenylene ether of the present invention can be produced by, for example, preparing a polymerization solution containing specific phenols, a catalyst, and a solvent (polymerization solution preparation step), passing oxygen through at least the solvent (oxygen supply step), It can be produced by oxidatively polymerizing phenols in the polymerization solution (polymerization step).

Hereinafter, the polymerization solution preparation process, oxygen supply process, and polymerization process will be explained. Note that each process may be carried out continuously, part or all of one process and part or all of another process may be carried out simultaneously, or one process may be interrupted and Another process may be performed. For example, an oxygen supply step may be carried out during the polymerization solution preparation step or during the polymerization step. Moreover, the method for producing polyphenylene ether of the present invention may include other steps as necessary. Other steps include, for example, a step of extracting polyphenylene ether obtained by the polymerization step (for example, a step of reprecipitation, filtration, and drying).

<<Polymerization solution preparation process>>
The polymerization solution preparation step is a step of mixing raw materials containing phenols to be polymerized in the polymerization step and preparing a polymerization solution. Raw materials for the polymerization solution include raw material phenols, catalysts, and solvents.

<Raw material phenols>
The method for producing polyphenylene ether of the present invention includes, as a raw material phenol, at least a phenol that satisfies the following condition 1 as an essential component. Examples of phenols that satisfy Condition 1 are phenols (A) and phenols (B), which will be described later.
(Condition 1)
Has hydrogen atoms in the ortho and para positions

A preferred method for producing polyphenylene ether of the present invention includes (Form 1) a form containing as an essential component a phenol (A) that satisfies both Conditions 1 and 2 below as a raw material phenol, or (Form 2) ) As raw material phenols, a form containing at least phenols (B) that satisfies condition 1 below but does not satisfy condition 2 and phenols (C) that does not satisfy condition 1 but satisfies condition 2 below as essential components; It is classified into two forms.
(Condition 1)
Has hydrogen atoms at the ortho and para positions (condition 2)
Has a hydrogen atom in the para position and a functional group containing an unsaturated carbon bond

Form 1 may further contain phenols (B) and/or phenols (C) as raw phenols. Moreover, the above-mentioned form 2 may be a form that further contains phenol (A) as the raw material phenol.

The method for producing polyphenylene ether of the present invention is preferably the form 2 above, or the form 1 containing phenols (B) and/or phenols (C) as additional essential components.

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

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

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

The method for producing polyphenylene ether of the present invention is most preferably a mode in which the method further includes phenols (D) as the raw material phenols in the above-mentioned mode 2.

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

The phenols (A) to (D) will be explained in more detail below.

As mentioned above, phenols (A) are phenols that satisfy both Conditions 1 and 2, that is, phenols that have hydrogen atoms at the ortho and para positions and 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. Note that, from the viewpoint of facilitating polymerization during oxidative polymerization, the hydrocarbon group preferably has 1 to 12 carbon atoms.

The 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- Examples include allyl-5-ethylphenol. Only one type of phenols represented by formula (1) may be used, or two or more types may be used.

As mentioned above, the phenol (B) is a phenol that satisfies condition 1 and does not satisfy condition 2, that is, it has hydrogen atoms at the ortho and para positions and does not have a functional group containing an unsaturated carbon bond. It is a phenol, preferably a phenol (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 an unsaturated carbon bond. Note that, from the viewpoint of facilitating polymerization during oxidative polymerization, the hydrocarbon group preferably has 1 to 12 carbon atoms.

The 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. The phenols represented by formula (2) may be used alone or in combination of two or more.

As mentioned above, phenols (C) are phenols that do not satisfy condition 1 but satisfy condition 2, that is, have a hydrogen atom in the para position, do not have a hydrogen atom in the ortho position, and have an unsaturated carbon bond. A phenol having a functional group containing the following, 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. Note that, from the viewpoint of facilitating polymerization during oxidative polymerization, the hydrocarbon group preferably has 1 to 12 carbon atoms.

The phenols (c) represented by 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 include -methyl-6-styrylphenol, 2-vinyl-6-methylphenol, and 2-vinyl-6-ethylphenol. Only one type of phenol represented by formula (3) may be used, or two or more types may be used.

As mentioned above, the phenol (D) is a phenol having a hydrogen atom at the para position, no hydrogen atom at the ortho position, and no functional group containing an unsaturated carbon bond, and is preferably one of the following: It is a phenol (d) represented by 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 are hydrogen atoms or having no unsaturated carbon bond. It is a hydrocarbon group having 1 to 15 carbon atoms. Note that, from the viewpoint of facilitating polymerization during oxidative polymerization, the hydrocarbon group preferably has 1 to 12 carbon atoms.

The phenols (d) represented by formula (4) include 2,6-dimethylphenol, 2,3,6-trimethylphenol, 2-methyl-6-ethylphenol, 2-ethyl-6-n-propylphenol. , 2-methyl-6-n-butylphenol, 2-methyl-6-phenylphenol, 2,6-diphenylphenol, and 2,6-ditolylphenol. Only one type of phenol represented by formula (4) may be used, or two or more types may be used.

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

Furthermore, other phenols may include phenols that do not have a hydrogen atom at the para position.

It is preferable that the proportion of phenols satisfying condition 1 to the total of raw material phenols is 1 to 50 mol%.

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

<Catalyst>
The catalyst is not particularly limited, and may be any suitable catalyst used in the oxidative polymerization of polyphenylene ether.

Examples of the catalyst include amine compounds and metal amine compounds consisting of heavy metal compounds such as copper, manganese, and cobalt and amine compounds such as tetramethylethylenediamine. It is preferable to use a copper-amine compound in which a copper compound is coordinated to an amine compound. Only one type of catalyst may be used, or two or more types may be used.

The content of the catalyst is not particularly limited, but may be 0.1 to 0.6 mol % based on the total amount of raw material phenols in the polymerization solution.

Such a catalyst may be dissolved in an appropriate solvent in advance.

<Solvent>
The solvent is not particularly limited, and may be any suitable solvent used in the oxidative polymerization of polyphenylene ether. It is preferable to use a solvent that can dissolve or disperse the phenolic compound and the catalyst.

Specific examples of the solvent include aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene, halogenated aromatic hydrocarbons such as chloroform, methylene chloride, chlorobenzene, dichlorobenzene, and trichlorobenzene, and nitro compounds such as nitrobenzene. Methyl ethyl ketone (MEK), cyclohexanone, tetrahydrofuran, ethyl acetate, N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), propylene glycol monomethyl ether acetate (PMA), diethylene glycol monoethyl ether acetate (CA) etc. Only one type of solvent may be used, or two or more types may be used.

Note that the solvent may include water, a solvent compatible with water, and the like.

The content of the solvent in the polymerization solution is not particularly limited and may be adjusted as appropriate.

<Other raw materials>
The polymerization solution may contain other raw materials to the extent that the effects of the present invention are not impaired.

<<Oxygen supply process>>
The oxygen supply step is a step in which oxygen-containing gas is passed through the polymerization solution.

The oxygen gas ventilation time and the oxygen concentration in the oxygen-containing gas used can be changed as appropriate depending on the atmospheric pressure, temperature, and the like.

<<Polymerization process>>
The polymerization step is a step in which phenols in the polymerization solution are oxidatively polymerized under conditions in which oxygen is supplied to the polymerization solution.

Specific polymerization conditions are not particularly limited, but for example, stirring may be performed at 25 to 100°C for 2 to 24 hours.

<<<Polyphenylene ether>>>
The polyphenylene ether of the present invention is a polyphenylene ether obtained from the above-mentioned raw material phenols. More specifically, the polyphenylene ether of the present invention is obtained by the above-mentioned production method, in other words, it is a polyphenylene ether obtained by oxidative polymerization of the above-mentioned raw material phenols.

Note that the raw material phenols shown here include phenols that satisfy at least Condition 1, as described above. The raw material phenols preferably include a phenol (A) that satisfies both Condition 1 and Condition 2, or a phenol (B) that satisfies Condition 1 but does not satisfy Condition 2, and Condition 1. and phenols (C) that do not satisfy the above condition 2 but satisfy the above condition 2. The raw material phenols are as described above.

Here, an example of structural analysis of the polyphenylene ether of the present invention will be shown.

Figure 1 is a 13C-NMR spectrum, the upper spectrum is that of the copolymer of o-cresol and 2-allyl-6-methylphenol of the present invention, and the lower spectrum is 2,6-dimethyl phenol. It is a copolymer of phenol and 2-allyl-6-methylphenol. As shown in the spectrum chart, it is difficult to identify the peaks of the polyphenylene ether (PPE) of the present invention, so the polyphenylene ether of the present invention was identified using synthetic raw materials.

Here, the structure of the polyphenylene ether of the present invention will be considered.

Phenols that satisfy Condition 1 {for example, phenols (A) and phenols (B)} have a hydrogen atom at the ortho position, so when they are oxidatively polymerized with phenols, they are not only at the ipso and para positions but also at the para position. Since an ether bond can be formed also at the ortho position, it is possible to form a branched structure.

When phenols that do not satisfy Condition 1 {for example, phenols (C) and phenols (D)} are oxidatively polymerized, ether bonds are formed at the ipso and para positions, and they are linearly polymerized. To go.

Moreover, phenols {for example, phenols (A) and phenols (C)} that satisfy Condition 2 have a hydrocarbon group containing at least an unsaturated carbon bond. Therefore, polyphenylene ether synthesized using phenols satisfying Condition 2 as a raw material has thermal crosslinkability because it has a hydrocarbon group containing an unsaturated carbon bond as a functional group.

As described above, the polyphenylene ether of the present invention has a part of its structure branched by a benzene ring having ether bonds at at least three positions: the ipso position, the ortho position, and the para position. The polyphenylene ether of the present invention is, for example, a polyphenylene ether having at least a branched structure as shown by formula (5) in the skeleton, and preferably has a hydrocarbon group containing at least one unsaturated carbon bond as a functional group. It is considered to be a compound.

In formula (5), R _a to R _k are hydrogen atoms or hydrocarbon groups having 1 to 15 carbon atoms (preferably 1 to 12 carbon atoms). However, it is preferable that at least one of R _a to R _k is a hydrocarbon group having an unsaturated carbon bond.

The polyphenylene ether of the present invention preferably has a number average molecular weight of 2,000 to 30,000. It is more preferably from 5,000 to 30,000, even more preferably from 8,000 to 30,000, and particularly preferably from 8,000 to 25,000. Further, the polyphenylene ether of the present invention preferably has a polydispersity index (PDI: weight average molecular weight/number average molecular weight) of 1.5 to 20. The number average molecular weight and weight average molecular weight are values measured by gel permeation chromatography (GPC) and converted using a calibration curve prepared using standard polystyrene.

From the viewpoint of solvent solubility, the hydroxyl value of the polyphenylene ether of the present invention is preferably 7.0 or more when the number average molecular weight (Mn) is 10,000 or more. In other words, when it is 5,000 or more, it is preferably 14.0 or more, and when it is 20,000 or more, it is preferably 3.5 or more.

The polyphenylene ether of the present invention has a weight average molecular weight (Mw) of 130,000 or more and a solution viscosity of 250 or less (P) when dissolved in chloroform at a concentration of 0.5 (g/mL). It is preferable that there be. Further, when the weight average molecular weight (Mw) is 35,000 or more and the concentration is 0.5 (g/mL), it is preferable that the solution viscosity is 250 or less (P).

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

Here, as described above, it is difficult to analyze the structure of polyphenylene ether by NMR spectroscopy, but the branched structure (degree of branching) of polyphenylene ether can be confirmed based on the following analysis procedure.

<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 the refractive index difference and concentration was created 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 device operating conditions. With reference to the chromatogram of the RI detector and the chromatogram of the MALS detector, a regression line is determined by the least squares method from a logarithmic graph (conformation plot) of molecular weight and radius of gyration, and its slope is calculated.

<Measurement conditions>
Equipment name: HLC8320GPC
Mobile phase: Chloroform column: TOSOH TSKguardcolumnHHR-H
+TSKgelGMHHR-H (2 pieces)
+TSKgelG2500HHR
Flow rate: 0.6mL/min.
Detector: DAWN HELEOS (MALS detector)
+Optilab rEX (RI detector, wavelength 254 nm)
Sample concentration: 0.5mg/mL
Sample solvent: Same as mobile phase. Dissolve 5 mg of sample in 10 mL of mobile phase Injection volume: 200 μL
Filter: 0.45μm
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

In resins having the same absolute molecular weight, the more branching of the polymer chain progresses, 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 radius of gyration obtained by GPC-MALS indicates the degree of branching, and the smaller the slope, the more advanced the branching is. In the present invention, the smaller the slope calculated by the above conformation plot, the more branches the polyphenylene ether has, and the larger the slope, the less branches the polyphenylene ether has.

In polyphenylene ether, the above-mentioned 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. When the above slope is within this range, it is considered that the polyphenylene ether has sufficient branching. Note that the lower limit of the above-mentioned slope 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.

Note that the slope of the conformation plot can be adjusted by changing the temperature, amount of catalyst, stirring speed, reaction time, amount of oxygen supply, and amount of solvent during synthesis of polyphenylene ether. More specifically, the slope of the conformation plot can be reduced 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. (polyphenylene ether tends to branch more easily).

<<Applications>>
The polyphenylene ether of the present invention maintains low dielectric properties and is soluble in various solvents (other than highly toxic solvents), so it can be applied to various uses.

Hereinafter, as specific uses of the polyphenylene ether of the present invention, a curable composition and a cured product obtained by curing the curable composition will be described.

<Curable composition>
The curable composition contains the polyphenylene ether of the present invention and a peroxide, and preferably further contains a crosslinked curing agent. Further, the curable composition may contain other components within a range that does not impede the effects of the present invention.

Since the polyphenylene ether of the present invention is as described above, the peroxide, crosslinked curing agent, and other components will be explained.

Peroxide has the effect of opening unsaturated carbon bonds contained in the preferred polyphenylene ether of the present invention and promoting the crosslinking reaction.

Examples of 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) Examples include benzene, etc. Only one kind of peroxide may be used, or two or more kinds of peroxides may be used.

Among these peroxides, those 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 peroxides have a relatively high reaction initiation temperature, they are difficult to accelerate curing at a time when curing is not necessary, such as during drying, and do not impair the storage stability of the polyphenylene ether resin composition, and also reduce volatility. Because of its low value, it does not volatilize during drying or storage, and has good stability.

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

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

The crosslinking type curing agent three-dimensionally crosslinks polyphenylene ether.

As a crosslinking type curing agent, one that has good compatibility with polyphenylene ether is used, but polyfunctional vinyl compounds such as divinylbenzene, divinylnaphthalene, and divinylbiphenyl; vinylbenzyl synthesized from the reaction of phenol and vinylbenzyl chloride; Ether compounds; allyl ether compounds synthesized from the reaction of styrene monomer, phenol, and allyl chloride; furthermore, trialkenyl isocyanurate and the like are good. As the cross-linked curing agent, trialkenyl isocyanurate is preferred because it has particularly good compatibility with polyphenylene ether, and specific examples include triallyl isocyanurate (hereinafter referred to as TAIC (registered trademark)) and triallyl cyanurate (hereinafter referred to as TAIC (registered trademark)). TAC) is preferred. These exhibit low dielectric properties and can enhance heat resistance. In particular, TAIC (registered trademark) is preferred because it has excellent compatibility with polyphenylene ether.

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

Preferred polyphenylene ethers of the present invention include hydrocarbon groups having unsaturated carbon bonds, although having a branched structure improves solubility with various solvents, but it may be difficult to improve dielectric properties. Therefore, by curing with TAIC (registered trademark), a cured product with excellent dielectric properties can be obtained.

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

The curable composition is usually provided or used in a state in which polyphenylene ether is dissolved in a 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 intended 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. (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 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 adjusted as appropriate 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 within a range that does not impede the effects of the present invention.

Note that such a curable composition can be obtained by appropriately mixing each raw material.

<Cured product>
The cured product can be obtained by curing the above-mentioned curable composition.

The method for obtaining a cured product from a curable composition is not particularly limited, and can be changed as appropriate depending on the composition of the curable composition. As an example, after carrying out the step of coating the curable composition on the substrate as described above (e.g., coating with an applicator, etc.), a drying step of drying the curable composition is carried out as necessary. Then, a thermosetting step may be carried out in which the polyphenylene ether is thermally crosslinked by heating (for example, heating using an inert gas oven, hot plate, vacuum oven, vacuum press machine, etc.). Note that the conditions for implementing each step (for example, coating thickness, drying temperature and time, heating temperature and time, etc.) may be changed as appropriate depending on the composition, use, etc. 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 base material.

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

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

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

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

To explain in detail, one or more prepregs of the present invention are stacked, metal foils such as copper foils are stacked on both sides or one side of the top and bottom, and the laminate is heated and press-molded to form an integrated laminate. It is possible to produce a laminate having metal foil on both sides or metal foil on one side.

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

Electronic components having a cured product are not particularly limited, but preferably include millimeter wave radars for high-capacity high-speed communications represented by 5th generation communication systems (5G) and automobile ADAS (advanced driving systems). .

The polyphenylene ether of the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

<<<Synthesis of polyphenylene ether>>>
In a 3L two-necked eggplant flask, 5.3g 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 sufficiently dissolved, and oxygen was supplied at 10 ml/min. 7.00 g of о-cresol, 13.7 g of 2-allyl-6-methylphenol, and 93.9 g of 2,6-dimethylphenol were dissolved in 1.5 L of toluene, added dropwise to a flask, and stirred at a rotation speed of 600 rpm. The reaction was carried out at 40°C for 6 hours. After the reaction was completed, it was reprecipitated with a mixed solution of 20 L of methanol and 22 mL of concentrated hydrochloric acid, filtered out, and dried at 80° C. for 24 hours to obtain a composite according to Example 1.

Compounds according to Examples 2 to 17 were obtained in the same manner as in Example 1 by changing the types of phenols and their blending ratios, but without changing the total blending amount of phenols. Table 1 shows the phenols used in the synthesis of Examples 1 to 17 and their blending ratios (molar ratios).

In addition, the number average molecular weight (Mn) and weight average molecular weight (Mw) of each compound were determined by gel permeation chromatography (GPC). The resulting Mn and polydispersity index (PDI: Mw/Mn) are shown in Table 1. In GPC, Shodex K-805L was used as a column, the column temperature was 40° C., the flow rate was 1 mL/min, the eluent was chloroform, and the standard material was polystyrene.

The slope of the conformational plot of each compound was determined according to the method described above. The measurement results are shown in Table 1.

＜＜Evaluation＞＞
<Solvent solubility test>
Chloroform, methylene chloride, toluene, methyl ethyl ketone (MEK), N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidone (NMP), tetrahydrofuran (THF), ethyl acetate, cyclohexanone, propylene glycol monomethyl Solubility tests were conducted in ether acetate (PMA) and diethylene glycol monoethyl ether acetate (CA).

100 g of various solvents and various compounds were placed in a 200 mL sample bottle, stirred for 10 minutes using a stirrer, and then left at 25° C. for 10 minutes, and the condition was visually observed and evaluated.

The evaluation criteria are: ◎ if 1g of the compound is dissolved and transparent, ○ if 0.01g of the compound is dissolved and transparent, and △ if there is turbidity when 0.01g of the compound is dissolved. , Those that precipitated were marked as ×. The evaluation results are shown in Table 2.

It was revealed that all the samples of Examples (Examples 1 to 14) were soluble in a wide range of solvents with SP values of 8.7 to 12.0.

<Measurement of hydroxyl value>
Accurately weigh approximately 2.0 g of the sample into a two-necked flask, add 10 mL of pyridine to dissolve it completely, and then add exactly 5 mL of an acetylating agent (a solution of 25 g of acetic anhydride dissolved in pyridine to a volume of 100 mL). The mixture was heated at 60° C. for 2 hours to acetylate the hydroxyl groups. After the reaction was completed, the reaction mother liquor was diluted with 10 mL of pyridine and purified by reprecipitation with 200 mL of warm water to decompose unreacted acetic anhydride. Furthermore, the two-necked flask was washed with 5 mL of ethanol. A few drops of phenolphthalein solution was added as an indicator to the hot water subjected to reprecipitation purification and titrated with 0.5 mol/L potassium hydroxide ethanol solution, and the end point was defined as when the indicator remained pale red for 30 seconds. In addition, in a blank test, the same operation was performed without adding a sample.
The measurement samples used were PPE (Nos. 1 to 3) with a number average molecular weight (Mn) of about 10,000 and different cresol contents.
The measurement results are shown in Table 3.

The hydroxyl value was determined from the following formula (unit: mgKOH/g).
Hydroxyl value (mgKOH/g)
= [{(ba)×F×28.05}/S]+D
however,
S: Sample amount (g)
a: Consumption amount (mL) of 0.5 mol/L potassium hydroxide ethanol solution
b: Consumption amount (mL) of blank test 0.5 mol/L potassium hydroxide ethanol solution
F: Factor D of 0.5 mol/L potassium hydroxide ethanol solution: Acid value (mgKOH/g)

<Measurement of solution viscosity>
The solution viscosities of cresol-containing PPE having similar weight average molecular weights (Mw) and conventional cresol-free PPE were measured.

1 g of cresol-containing PPE resin and cresol-free PPE resin each having the same Mw were accurately weighed, 2.5 mL of chloroform was added, a stirring bar was added, and the mixture was stirred for 10 minutes to completely dissolve (concentration c = 0). .4g/mL). Thereafter, the solution viscosity (η) was measured using a TV type viscometer. Similarly, the solution viscosity at c=0.45 and 0.5 g/mL was measured.
The measurement results are shown in Table 4.
These results indicate that when PPE contains cresol as a constituent unit, the thickening of the solution is suppressed even when this PPE is dissolved, and that the thickening suppressing effect increases as the content of cresol in PPE increases. It was done.

<<<Preparation of composition>>>
Varnishes were obtained by dissolving 50 g of the compounds of Examples 1 to 14 in 150 g of cyclohexanone. These varnishes were named PPE-1 to PPE-14.

Further, varnish was obtained by dissolving 50 g of the composites of Examples 15 to 17 in 150 g of chloroform. These varnishes were named PPE-15 to PPE-17.

Each material was blended according to Table 5 and dissolved by stirring to obtain each composition (compositions of Examples 15 to 32 and Comparative Examples 4 to 6). The units of numbers are parts by mass.

Furthermore, as an evaluation of environmental friendliness, varnishes using cyclohexanone as a solvent were rated ○, and varnishes using chloroform as a solvent were rated x. The results are shown in Table 5.

Note that "Perbutyl P" in Table 5 indicates α,α'-bis(t-butylperoxy-m-isopropyl)benzene.

＜＜Evaluation＞＞
<Method for measuring dielectric properties>
The dielectric properties, dielectric constant Dk and dielectric loss tangent Df, were measured according to the following methods.

The compositions of Examples 15 to 32 and Comparative Examples 4 to 6 were applied to the shine side of 18 μm thick copper foil using an applicator so that the thickness of the cured product was 50 μm. Next, it was dried at 90° C. for 30 minutes in a hot air circulation drying oven. Thereafter, the inert oven was completely filled with nitrogen and the temperature was raised to 200° C., followed by curing for 60 minutes. Thereafter, the copper foil was etched and cut into pieces having a length of 80 mm, a width of 45 mm, and a thickness of 50 μm, which were used as test pieces and measured by the SPDR (Split Post Dielectric Resonator) resonator method. The measuring equipment used was a vector network analyzer E5071C manufactured by Keysight Technologies LLC, an SPDR resonator, and a calculation program manufactured by QWED. The conditions were a frequency of 10 GHz and a measurement temperature of 25°C.

(Evaluation criteria)
As for dielectric property evaluation, those with Df less than 0.004 were evaluated as ◎, those with Df of 0.004 or more and less than 0.008 were evaluated as ○, and those with Df of 0.008 or more were evaluated as ×. The measurement results are shown in Table 5.

<Heat resistance test>
A 150 mm x 95 mm, 1.6 mm thick FR-4 copper clad laminate was buffed, and the compositions of Examples 15 to 32 and Comparative Examples 4 to 6 were cured to a thickness of 50 μm. It was applied with an applicator. Next, it was dried for 30 minutes at 90°C in a hot air circulation type drying oven. Then, using an inert oven, it was completely filled with nitrogen, heated to 200° C., and then cured for 60 minutes to prepare a test piece.

Rosin-based flux was applied to each test piece, flowed into a solder bath at 260°C for 30 seconds, washed with propylene glycol monomethyl ether acetate, and visually evaluated for swelling and peeling. Furthermore, this test was repeated twice and evaluated in the same manner.

(Evaluation criteria)
A sample with no blistering or peeling after three tests was rated as ◎, a sample with no blistering or peeling after one test was rated as ○, and a sample with blistering or peeling after one test was graded as ×. The measurement results are shown in Table 5.

Claims (11)

A curable composition containing a polyphenylene ether having an allyl group or a vinyl group, which is obtained from raw material phenols and has a slope calculated in a conformation plot measured by the following analytical procedure , and has an allyl group or a vinyl group,
The polyphenylene ether has, as the raw material phenols,
Contains at least a phenol (A) that satisfies both Condition 1 and Condition 2 below, or
Contains at least a phenol (B) that satisfies the following condition 1 but does not satisfy the following condition 2, and a phenol (C) that does not satisfy the following condition 1 but satisfies the following condition 2,
A resin composition characterized by:
(Condition 1)
Has hydrogen atoms at the ortho and para positions (condition 2)
Has a hydrogen atom in the para position and has an allyl group or a vinyl group
(Analysis procedure)
After preparing chloroform solutions of polyphenylene ether at intervals of 0.1, 0.15, 0.2, and 0.25 mg/mL, create a graph of refractive index difference and concentration while feeding the solution at 0.5 mL/min. Then, the 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, a regression line is determined by the least squares method from a logarithmic graph (conformation plot) of molecular weight and radius of gyration, and its slope is calculated.
(Device operating conditions)
Equipment name: HLC8320GPC
Mobile phase: Chloroform
Column: TOSOH TSKguardcolumnHHR-H
+TSKgelGMHHR-H (2 pieces)
+TSKgelG2500HHR
Flow rate: 0.6mL/min.
Detector: DAWN HELEOS (MALS detector)
+Optilab rEX (RI detector, wavelength 254 nm)
Sample concentration: 0.5mg/mL
Sample solvent: Same as mobile phase. Dissolve 5 mg of sample in 10 mL of mobile phase
Injection volume: 200μL
Filter: 0.45μm
STD reagent: Standard polystyrene Mw 37,900
STD concentration: 1.5mg/mL
STD solvent: Same as mobile phase. Dissolve 15mg of sample in 10mL of mobile phase
Analysis time: 100min The resin composition according to claim 1, wherein the phenol (A) is a phenol (a) represented by the following 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 an allyl group or a vinyl group.) The resin composition according to claim 1 or 2, wherein the phenol (B) is a phenol (b) represented by the following 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 resin composition according to any one of claims 1 to 3, wherein the phenol (C) is a phenol (c) represented by the following 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, R ₇ to R ₁₀ At least one of them is an allyl group or a vinyl group.) The resin composition according to any one of claims 1 to 4, wherein the ratio of the phenols satisfying the condition 1 to the total of the raw material phenols is 1 to 50 mol%. The resin composition according to any one of claims 1 to 5, wherein the polyphenylene ether is soluble in 1 g of cyclohexanone at 25°C. The resin composition according to any one of claims 1 to 6, characterized in that it contains a crosslinked curing agent. A dry film or prepreg obtained by applying the resin composition according to any one of claims 1 to 7 to a base material. A cured product obtained by curing the resin composition according to any one of claims 1 to 7. A laminate comprising the cured product according to claim 9. An electronic component comprising the cured product according to claim 9.