Polyphenylene ether, curable composition containing polyphenylene ether, dry film, prepreg, cured product, laminate, and electronic component

Abstract

To provide a polyphenylene ether having both of low dielectric properties and excellent insulation reliability.SOLUTION: A polyphenylene ether is obtained from a raw material phenol containing a phenol satisfying at least condition 1 and has an inclination of less than 0.6 calculated by a conformation plot, in which the copper concentration is less than 100 ppm and the chlorine concentration is less than 500 ppm. (Condition 1) It has hydrogen atoms at ortho position and para position.There is also provided a curable composition comprising the polyphenylene ether.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polyphenylene ether and a curable composition containing the polyphenylene ether, and further to a dry film, a prepreg, a cured product, a laminate, and an electronic component which use the curable composition containing the polyphenylene ether. [Background technology]

[0002] Due to the spread of high-capacity, high-speed communications such as those represented by the fifth-generation communication system (5G) and millimeter-wave radar for automotive ADAS (Advanced Driver Assistance Systems), signals from communication devices are becoming increasingly higher in frequency.

[0003] However, for example, when epoxy resin is used as a wiring board material, the relative dielectric constant (Dk) and dielectric loss tangent (Df) are not sufficiently low, so that as the frequency increases, the transmission loss due to dielectric loss increases, causing problems such as signal attenuation and heat generation. Therefore, various materials such as polyphenylene ether, which has excellent low dielectric properties, have been proposed and used for such high-frequency applications.

[0004] For example, Non-Patent Document 1 proposes polyphenylene ether with improved heat resistance by introducing an allyl group into the molecule of polyphenylene ether to form a thermosetting resin. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] J. Nunoshige, H. Akahoshi, Y. Shibasaki, M. Ueda, J. Polym. Sci. Part A: Polym. Chem. 2008, 46, 5278-5282. DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0006] On the other hand, in order to realize excellent insulation reliability, resin components used in insulating films of wiring boards and the like are required to be highly purified resins by reducing impurities such as copper catalysts and chlorine used in the synthesis of the resin components. However, conventional polyphenylene ethers are soluble in limited solvents, 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 in that it is difficult to remove impurities by refining the resin.

[0007] Therefore, an object of the present invention is to provide a highly purified polyphenylene ether which combines low dielectric properties with excellent insulating reliability, and a curable composition containing the polyphenylene ether. [Means for solving the problem]

[0008] As a result of intensive research aimed at achieving the above object, the present inventors have found that polyphenylene ether having a branched structure has improved solubility in a solvent, and can be purified to reduce impurities such as copper catalyst and chlorine, thereby providing polyphenylene ether purified to a high purity, and have completed the present invention.

[0009] The present invention (1) is A polyphenylene ether obtained from a raw material phenol containing at least a phenol satisfying condition 1, and having a slope calculated in a conformation plot of less than 0.6, The chlorine concentration is less than 500 ppm, Characterized by a copper concentration of less than 100 ppm It is a polyphenylene ether.

[0010] The present invention (2) is A curable composition comprising the polyphenylene ether of the invention (1).

[0011] The present invention (3) is A dry film or prepreg is obtained by coating or impregnating a substrate with the curable composition of the above invention (2).

[0012] The present invention (4) is A cured product obtained by curing the curable composition of the above invention (2).

[0013] The present invention (5) is A laminate comprising the cured product of the invention (4).

[0014] The present invention (6) is An electronic part comprising the cured product according to the fourth aspect of the present invention. Effect of the Invention

[0015] According to the present invention, it is possible to provide a highly purified polyphenylene ether which combines low dielectric properties with excellent insulating reliability, and a curable composition containing the polyphenylene ether. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The polyphenylene ether of the present invention and a curable composition containing the polyphenylene ether will be described below, but the present invention is not limited to the following in any way.

[0017] When isomers exist in the described compounds, all possible isomers can be used in the present invention unless otherwise specified.

[0018] In the present invention, phenols that are used as raw materials for polyphenylene ether (PPE) and can become structural units of polyphenylene ether are collectively referred to as "raw material phenols".

[0019] In the present invention, when the raw material phenols are described using expressions such as "ortho position" and "para position", the position of the phenolic hydroxyl group is taken as the reference (ipso position) unless otherwise specified.

[0020] In the present invention, when simply expressed as "ortho position" or the like, it means "at least one of the ortho positions", etc. Therefore, unless there is any particular contradiction, when simply expressed as "ortho position", it may be interpreted as indicating either one of the ortho positions, or it may be interpreted as indicating both ortho positions.

[0021] In the present invention, polyphenylene ether in which some or all of the functional groups (e.g., hydroxyl groups) of the polyphenylene ether have been modified may be simply referred to as "polyphenylene ether". Therefore, when the term "polyphenylene ether" is used, it includes both unmodified polyphenylene ether and modified polyphenylene ether, unless there is a particular contradiction.

[0022] In this specification, monohydric phenols are mainly disclosed as the raw material phenols, but polyhydric phenols may also be used as the raw material phenols within the range that does not impair the effects of the present invention.

[0023] In this specification, the term "resin composition" may be used to mean a "curable composition".

[0024] In this specification, when the upper limit and the lower limit of a numerical range are separately described, all combinations of the lower limit and the upper limit are substantially described, provided that there is no contradiction.

[0025] <<<<Polyphenylene Ether>>>> The polyphenylene ether of the present invention is a polyphenylene ether having a branched structure, which is obtained from a raw material phenol containing a phenol satisfying at least condition 1. Such a polyphenylene ether is referred to as a predetermined polyphenylene ether. (Condition 1) Contains hydrogen atoms at the ortho and para positions

[0026] Phenols satisfying condition 1 {e.g., phenols (A) and (B) described later} have a hydrogen atom at the ortho position, and therefore, when oxidatively polymerized with a phenol, an ether bond can be formed not only at the ipso position and para position but also at the ortho position, making it possible to form a branched chain structure.

[0027] Such a polyphenylene ether having a branched structure may be referred to as a branched polyphenylene ether.

[0028] In this way, the specific polyphenylene ether has a structure in which a part of the structure is branched by benzene rings having ether bonds at least at three positions, i.e., the ipso, ortho, and para positions. This specific polyphenylene ether is considered to be, for example, a polyphenylene ether compound having at least a branched structure as represented by formula (i) in the skeleton.

[0029] [ka]

[0030] In formula (i), R a ~R k is a hydrogen atom or a hydrocarbon group having 1 to 15 carbon atoms (preferably 1 to 12 carbon atoms).

[0031] Here, the raw material phenols constituting the predetermined polyphenylene ether may contain other phenols not satisfying condition 1 within the range that does not impair the effects of the present invention.

[0032] Examples of such other phenols include phenols (C) and (D) described later, and phenols that do not have a hydrogen atom at the para position. In particular, when phenols (C) and (D) described later are oxidatively polymerized, ether bonds are formed at the ipso and para positions, and the phenols are polymerized in a linear chain. Therefore, in order to increase the molecular weight of polyphenylene ether, it is preferable to further include phenols (C) and (D) as raw material phenols.

[0033] Here, the predetermined polyphenylene ether preferably has a functional group containing an unsaturated carbon bond. The method for incorporating the functional group containing an unsaturated carbon bond into the polyphenylene ether is not particularly limited, but the following [Method 1] or [Method 2] is preferable.

[0034] [Method 1] Method 1 is, As raw phenols, The composition contains a phenol (A) that satisfies at least both of the following conditions 1 and 2 (form 1), or This method (Mode 2) comprises incorporating a mixture of a phenol (B) that satisfies at least 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. (Condition 1) Contains hydrogen atoms at the ortho and para positions (Condition 2) It has a hydrogen atom at the para position and a functional group containing an unsaturated carbon bond.

[0035] According to Method 1, a desired polyphenylene ether having a functional group containing an unsaturated carbon bond derived from the raw material phenol can be obtained.

[0036] [Method 2] Method 2 is, In this method, the terminal hydroxyl groups of a branched polyphenylene ether are modified with functional groups containing unsaturated carbon bonds to obtain a terminal-modified polyphenylene ether.

[0037] According to method 2, even when the starting phenol does not have a functional group containing an unsaturated carbon bond, it is possible to obtain a desired polyphenylene ether into which a functional group containing an unsaturated carbon bond has been introduced.

[0038] [Method 1] and [Method 2] may be carried out simultaneously.

[0039] <<Prescribed polyphenylene ether obtained by method 1>>

[0040] The specific polyphenylene ether obtained by method 1 has at least crosslinkability due to a hydrocarbon group containing an unsaturated carbon bond, since at least a phenol satisfying condition 2 {e.g., either phenol (A) or phenol (C)} is used as a phenol raw material. When the specific polyphenylene ether has such a hydrocarbon group containing an unsaturated carbon bond, it is also possible to carry out modification such as epoxidation using a compound which reacts with the hydrocarbon group and has a reactive functional group such as an epoxy group.

[0041] That is, the specific polyphenylene ether obtained by method 1 is, for example, a polyphenylene ether having at least a branched structure as shown in 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. a ~R k At least one of the above is a hydrocarbon group having an unsaturated carbon bond.

[0042] In particular, in the above embodiment 2, from the industrial and economical viewpoints, it is preferable that the phenol (B) is at least one of o-cresol, 2-phenylphenol, 2-dodecylphenol, and phenol, and the phenol (C) is 2-allyl-6-methylphenol.

[0043] The phenols (A) to (D) will be described in more detail below.

[0044] The phenol (A) is a phenol that satisfies both the condition 1 and the condition 2 as described above, i.e., a phenol that has hydrogen atoms at the ortho-position and the para-position and has a functional group containing an unsaturated carbon bond, and is preferably a phenol (a) represented by the following formula (1).

[0045] [ka]

[0046] In formula (1), R1 to R3 are hydrogen atoms or hydrocarbon groups having 1 to 15 carbon atoms. However, at least one of R1 to R3 is a hydrocarbon group having an unsaturated carbon bond. From the viewpoint of facilitating polymerization by oxidative polymerization, the hydrocarbon group preferably has 1 to 12 carbon atoms.

[0047] Examples of the phenol (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, etc. The phenol represented by formula (1) may be used alone or in combination of two or more.

[0048] As described above, the phenol (B) is a phenol that satisfies the condition 1 but does not satisfy the condition 2, i.e., a phenol that has hydrogen atoms at the ortho- and para-positions and does not have a functional group containing an unsaturated carbon bond, and is preferably a phenol (b) represented by the following formula (2).

[0049] [ka]

[0050] In formula (2), R4 to R6 are hydrogen atoms or hydrocarbon groups having 1 to 15 carbon atoms. However, R4 to R6 do not have unsaturated carbon bonds. From the viewpoint of facilitating polymerization by oxidative polymerization, the hydrocarbon groups preferably have 1 to 12 carbon atoms.

[0051] Examples of the phenol (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, etc. The phenol represented by formula (2) may be used alone or in combination of two or more.

[0052] As described above, the phenol (C) is a phenol that does not satisfy condition 1 but satisfies condition 2, i.e., a phenol that has a hydrogen atom at the para position, does not have a hydrogen atom at the ortho position, and has a functional group containing an unsaturated carbon bond, and is preferably a phenol (c) represented by the following formula (3).

[0053] [ka]

[0054] In formula (3), R7 and R 10 is a hydrocarbon group having 1 to 15 carbon atoms, and R8 and R9 are a hydrogen atom or a hydrocarbon group having 1 to 15 carbon atoms. 10 At least one of the above is a hydrocarbon group having an unsaturated carbon bond. From the viewpoint of facilitating polymerization into a polymer during oxidative polymerization, the hydrocarbon group preferably has 1 to 12 carbon atoms.

[0055] Examples of the 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, etc. The phenols represented by formula (3) may be used alone or in combination of two or more.

[0056] As described 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 a phenol (d) represented by the following formula (4).

[0057] [ka]

[0058] In formula (4), R 11 and R 14 is a hydrocarbon group having 1 to 15 carbon atoms and no unsaturated carbon bond, R 12 and R 13 is a hydrogen atom or a hydrocarbon group having 1 to 15 carbon atoms and no unsaturated carbon bonds. From the viewpoint of facilitating polymerization into a polymer during oxidative polymerization, the hydrocarbon group preferably has 1 to 12 carbon atoms.

[0059] Examples of the phenol (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, 2,6-ditolylphenol, etc. The phenol represented by formula (4) may be used alone or in combination of two or more.

[0060] In the present invention, examples of the hydrocarbon group include an alkyl group, a cycloalkyl group, an aryl group, an alkenyl group, and an alkynyl group, and 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. These hydrocarbon groups may be linear or branched.

[0061] <<Prescribed polyphenylene ether obtained by method 2>> The polyphenylene ether obtained by method 2 is a terminal-modified branched polyphenylene ether.

[0062] Such a terminal-modified branched polyphenylene ether has a branched structure and a modified terminal hydroxyl group, and therefore, while being soluble in various solvents, a cured product having further reduced low dielectric properties can be obtained. Furthermore, since the terminal-modified branched polyphenylene ether has an unsaturated carbon bond at the terminal position, the reactivity is extremely good, and the performance of the obtained cured product is further improved.

[0063] When the terminal hydroxyl group is modified with a modifying compound, an ether bond or an ester bond is usually formed between the terminal hydroxyl group and the modifying compound.

[0064] The modifying compound is not particularly limited as long as it contains a functional group having an unsaturated carbon bond and is capable of reacting with a phenolic hydroxyl group in the presence or absence of a catalyst.

[0065] A suitable example of the modifying compound is an organic compound represented by the following formula (11).

[0066] [ka]

[0067] In formula (11), R A , R B , R C are each independently a hydrogen atom or a hydrocarbon group having 1 to 9 carbon atoms; R D is a hydrocarbon group having 1 to 9 carbon atoms, and X is a group capable of reacting with a phenolic hydroxyl group, such as F, Cl, Br, I or CN.

[0068] From another point of view, a suitable example of the modifying compound is an organic compound represented by the following formula (11-1).

[0069] [ka]

[0070] In formula (11-1), R is a vinyl group, an allyl group, or a (meth)acryloyl group, and X is a group such as F, Cl, Br, or I that can react with a phenolic hydroxyl group.

[0071] The modification of the terminal hydroxyl groups of the branched polyphenylene ether can be confirmed by comparing the hydroxyl values ​​of the branched polyphenylene ether and the terminal-modified branched polyphenylene ether. Note that the terminal-modified branched polyphenylene ether may have some unmodified hydroxyl groups.

[0072] The reaction temperature, reaction time, the presence or absence of a catalyst, the type of catalyst, etc. during the modification can be appropriately designed. Two or more types of compounds may be used as the modifying compound.

[0073] When a specified polyphenylene ether is obtained by method 2, the branched polyphenylene ether before modification may be a branched polyphenylene ether containing an unsaturated carbon bond (the specified polyphenylene ether obtained by the above-mentioned method 1) or may be a branched polyphenylene ether not containing an unsaturated carbon bond.

[0074] The branched polyphenylene ether containing no unsaturated carbon bonds may be a polyphenylene ether obtained from raw material phenols which contain at least a phenol satisfying the following condition 1 and which does not contain a phenol satisfying the following condition Z. (Condition 1) Contains hydrogen atoms at the ortho and para positions (Condition Z) Contains functional groups with unsaturated carbon bonds

[0075] In this way, the branched polyphenylene ether containing no unsaturated carbon bonds satisfies the condition 1 and contains a phenol that does not satisfy the condition Z {for example, the phenol (B)} as an essential component.

[0076] The branched polyphenylene ether containing no unsaturated carbon bonds may contain other phenols not satisfying condition Z as further raw material phenols.

[0077] Other phenols not satisfying condition Z include, for example, phenols (D) which are phenols having a hydrogen atom at the para position, no hydrogen atom at the ortho position, and no functional group containing an unsaturated carbon bond, and phenols which do not have a hydrogen atom at the para position and no functional group containing an unsaturated carbon bond.

[0078] In order to obtain a polyphenylene ether having a high molecular weight, it is preferred that the polyphenylene ether further contains a phenol (D) as a raw material phenol in the polyphenylene ether having no unsaturated carbon bonds.

[0079] When a branched polyphenylene ether not containing unsaturated carbon bonds is used as a raw material, the raw material phenols do not contain phenols satisfying the above condition Z, so that no unsaturated carbon bonds are introduced into the side chains. A part or all of the terminal hydroxyl groups of the polyphenylene ether obtained by oxidative polymerization of the raw material phenols are modified into a functional group having an unsaturated carbon bond, thereby imparting curability. As a result, deterioration of low dielectric properties, light resistance, and environmental resistance due to the terminal hydroxyl groups is suppressed, and the unsaturated carbon bonds at the terminal sites have excellent reactivity, so that a cured product with a crosslinking curing agent described later can obtain high strength and excellent crack resistance.

[0080] When the branched polyphenylene ether does not contain an unsaturated carbon bond, the ratio of phenols that satisfy the condition 1 but do not satisfy the condition Z to the total of the raw material phenols is, for example, 10 mol % or more.

[0081] Here, examples of the hydrocarbon group that does not contain a functional group having an unsaturated carbon bond include an alkyl group, a cycloalkyl group, an aryl group, etc. These hydrocarbon groups may be linear or branched.

[0082] In Method 1 or Method 2, the ratio of the phenols satisfying Condition 1 to the total of the raw material phenols used in the synthesis of the predetermined polyphenylene ether is preferably 1 to 50 mol %.

[0083] Furthermore, it is not necessary to use phenols satisfying the above condition 2. However, if used, the ratio of phenols satisfying the condition 2 to the total amount of raw material phenols is preferably 0.5 to 99 mol %, and more preferably 1 to 99 mol %.

[0084] The specific polyphenylene ether obtained by the method 1 or method 2 described above has a branched structure, which improves the solubility and compatibility in various solvents. For this reason, after synthesis, the specific polyphenylene ether is dissolved in a hydrophilic solvent and mixed with water at the same time, so that the copper catalyst used in the synthesis is dissolved in water without remaining in the resin, and further, the chlorine remaining due to hydrochloric acid can be reduced, and the polyphenylene ether can be purified to a high purity. When the specific polyphenylene ether of the present invention obtained and purified to a high purity is used as a component of a curable composition described later, the components in the composition are uniformly dissolved or dispersed, making it possible to obtain a uniform cured product. As a result, the cured product has low dielectric properties, excellent insulation reliability, and excellent mechanical properties.

[0085] The physical properties and characteristics of the highly purified polyphenylene ether of the present invention will now be described. <<Physical properties and characteristics of specific polyphenylene ethers>> <Degree of branching of a given polyphenylene ether> The branched structure (degree of branching) of a given polyphenylene ether can be confirmed based on the following analytical procedure.

[0086] (Analysis Procedure) After preparing polyphenylene ether chloroform solutions at intervals of 0.1, 0.15, 0.2, and 0.25 mg / mL, a graph of refractive index difference and concentration is created while feeding at 0.5 mL / min, and the refractive index increment dn / dc is calculated from the slope. Next, the absolute molecular weight is measured under the following device operating conditions. Using the chromatograms from the RI detector and the MALS detector, a regression line is obtained by the least squares method from a logarithmic graph (conformation plot) of molecular weight and radius of gyration, and the slope is calculated.

[0087] (Measurement conditions) Device 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 15 mg of sample in 10 mL of mobile phase. Analysis time: 100min

[0088] In resins with the same absolute molecular weight, the more the branching of the polymer chain progresses, the smaller the distance from the center of gravity to each segment (radius of gyration). Therefore, the slope of the logarithmic plot of absolute molecular weight and radius of gyration obtained by GPC-MALS indicates the degree of branching, and the smaller the slope, the more the branching progresses. In the present invention, the smaller the slope calculated in the above conformation plot indicates the more the polyphenylene ether branches, and the larger the slope, the less the polyphenylene ether branches.

[0089] In the specific polyphenylene ether of the present invention, the inclination is preferably less than 0.6, 0.55 or less, 0.50 or less, 0.45 or less, 0.40 or less, or 0.35 or less. When the inclination is within this range, the polyphenylene ether is considered to have sufficient branching. The lower limit of the inclination is not particularly limited, and is, for example, 0.05 or more, 0.10 or more, 0.15 or more, or 0.20 or more.

[0090] The slope of the conformation plot can be adjusted by changing the temperature, amount of catalyst, stirring speed, reaction time, amount of oxygen supplied, and amount of solvent during the synthesis of polyphenylene ether. More specifically, the slope of the conformation plot tends to become lower (polyphenylene ether becomes more easily branched) by increasing the temperature, increasing the amount of catalyst, increasing the stirring speed, lengthening the reaction time, increasing the amount of oxygen supplied, and / or decreasing the amount of solvent.

[0091] <Molecular weight of specified polyphenylene ether> The number average molecular weight of the specific polyphenylene ether of the present invention is preferably 2,000 to 30,000, more preferably 5,000 to 30,000, further preferably 8,000 to 30,000, and particularly preferably 8,000 to 25,000. By setting the molecular weight within such a range, it is possible to improve the film-forming property of the curable resin composition while maintaining the solubility in a solvent. Furthermore, the specific polyphenylene ether constituting the curable composition of the present invention preferably has a polydispersity index (PDI: weight average molecular weight / number average molecular weight) of 1.5 to 20.

[0092] In the present invention, the number average molecular weight and the weight average molecular weight are measured by gel permeation chromatography (GPC) and converted based on a calibration curve prepared using standard polystyrene.

[0093] <Hydroxyl value of specified polyphenylene ether> The hydroxyl value of the predetermined polyphenylene ether of the present invention is preferably 15.0 or less, more preferably 2 or more and 10 or less, and further preferably 3 or more and 8 or less, when the number average molecular weight (Mn) is in the range of 2,000 to 30,000.

[0094] In addition, when the specified polyphenylene ether is a specified polyphenylene ether obtained by method 2, etc., the hydroxyl value may be lower than the above-mentioned value.

[0095] <Solubility of specific polyphenylene ether in solvent> 1 g of a specific polyphenylene ether is preferably soluble in 100 g of cyclohexanone (more preferably, 100 g of cyclohexanone, DMF and PMA) at 25° C. Here, 1 g of polyphenylene ether is soluble in 100 g of a solvent (e.g., cyclohexanone) means that when 1 g of polyphenylene ether is mixed with 100 g of a solvent, no turbidity or precipitation can be visually confirmed. More preferably, this specific polyphenylene ether is soluble in 1 g or more of cyclohexanone at 25° C. in 100 g of cyclohexanone.

[0096] <Copper and chlorine concentrations> Certain polyphenylene ethers of the present invention have a copper concentration of less than 100 ppm, preferably less than 20 ppm.

[0097] The copper concentration of polyphenylene ether can be obtained by weighing out a sample of polyphenylene ether into a platinum crucible, heating it in an electric furnace at 600°C for 1 hour to volatilize and burn the resin, and then dissolving the residue in nitric acid, adjusting the volume to 100 ml, and measuring it by ICP optical emission spectrometry (apparatus: ICP optical emission spectrometer Varian 720-ES).

[0098] Certain polyphenylene ethers of the present invention have a chlorine concentration of less than 500 ppm, preferably less than 70 ppm.

[0099] The chlorine concentration of polyphenylene ether is measured by burning the polyphenylene ether sample under oxygen flow, absorbing the generated gas into 0.3% hydrogen peroxide solution, and then measuring the chloride ions in the absorbed solution by ion chromatography (instrument: Thermo Fisher Scientific Integrion).

[0100] The specified polyphenylene ether of the present invention having such copper and chlorine concentrations can be obtained by carrying out the purification step described below.

[0101] The method for producing the highly purified polyphenylene ether of the present invention will be described below. <<Method of producing a specific polyphenylene ether>> The highly purified specific polyphenylene ether of the present invention can be produced by applying a conventionally known method for synthesizing polyphenylene ether (polymerization conditions, the presence or absence of a catalyst, the type of catalyst, etc.), except for using a specific raw material phenol.

[0102] Next, an example of a method for producing the predetermined polyphenylene ether will be described.

[0103] The specified polyphenylene ether can be produced, for example, by preparing a polymerization solution containing a specific phenol, a copper catalyst, and a solvent (polymerization solution preparation step), bubbling oxygen into at least the solvent (oxygen supply step), oxidatively polymerizing the phenol in the oxygen-containing polymerization solution (polymerization step), and reducing the copper concentration (copper concentration derived from the copper catalyst) contained in the specified polyphenylene ether (purification step).

[0104] The polymerization solution preparation step, oxygen supply step, polymerization step, and purification step will be described below. Each step may be carried out continuously, or a part or all of a certain step may be carried out simultaneously with a part or all of another step, or a certain step may be interrupted and another step may be carried out during that time. For example, an oxygen supply step may be carried out during the polymerization solution preparation step or the polymerization step. In addition, the method for producing polyphenylene ether of the present invention may include other steps as necessary. Examples of the other steps include a step of extracting polyphenylene ether obtained by the polymerization step (for example, a step of performing reprecipitation, filtration, and drying), the above-mentioned modification step, and the like.

[0105] <Polymerization solution preparation process> The polymerization solution preparation step is a step of preparing a polymerization solution by mixing raw materials including phenols to be polymerized in the polymerization step described below. The raw materials for the polymerization solution include raw phenols, a copper catalyst, and a solvent.

[0106] (copper catalyst) The copper catalyst is not particularly limited, and may be any suitable copper catalyst used in the oxidative polymerization of polyphenylene ether.

[0107] The copper catalyst may be, for example, a metal amine compound consisting of copper and an amine compound such as tetramethylethylenediamine, and in order to obtain a copolymer with a sufficient molecular weight, it is particularly preferable to use a copper-amine compound in which a copper compound is coordinated to an amine compound. Only one type of copper catalyst may be used, or two or more types may be used.

[0108] The content of the copper catalyst is not particularly limited, but may be, for example, 0.1 to 0.6 mol % based on the total amount of the raw material phenols in the polymerization solution.

[0109] Such a copper catalyst may be dissolved in advance in a suitable solvent.

[0110] (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 capable of dissolving or dispersing the phenolic compound and the catalyst.

[0111] 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, nitro compounds such as nitrobenzene, methyl ethyl ketone (MEK), cyclohexanone, tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), ethyl acetate, N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), propylene glycol monomethyl ether acetate (PMA), diethylene glycol monoethyl ether acetate (CA), 1,4-dioxane, and acetonitrile. Among these, toluene is preferred because it does not inhibit the synthesis reaction and can stably carry out the reaction. Only one type of solvent may be used, or two or more types may be used.

[0112] The solvent may include water or a solvent compatible with water.

[0113] The content of the solvent in the polymerization solution is not particularly limited and may be appropriately adjusted.

[0114] (Other ingredients) The polymerization solution may contain other raw materials as long as the effects of the present invention are not impaired.

[0115] <Oxygen supply process> The oxygen supplying step is a step of bubbling an oxygen-containing gas into the polymerization solution.

[0116] The time for which oxygen gas is passed through and the oxygen concentration in the oxygen-containing gas used can be appropriately changed depending on the atmospheric pressure, temperature, and the like.

[0117] <Polymerization process> The polymerization step is a step in which phenols in a polymerization solution are oxidatively polymerized under conditions in which oxygen is supplied to the polymerization solution.

[0118] Specific polymerization conditions are not particularly limited, but may be, for example, stirring at 25 to 100° C. for 2 to 24 hours.

[0119] In the polymerization of a specific polyphenylene ether through the steps as described above, a specific method for introducing a branched polyphenylene ether and further a functional group containing an unsaturated carbon bond can be understood by referring to the above-mentioned Method 1 and Method 2. That is, a specific polyphenylene ether having a functional group containing an unsaturated carbon bond (polymer solution) can be obtained by using a specific type of raw material phenol or by further providing a step (modification step) of modifying a terminal hydroxyl group after the polymerization step.

[0120] <Purification process> The purification step may, for example, be a primary purification step of contacting a solution containing the predetermined polyphenylene ether (polymer solution) obtained in the polymerization step and a good solvent which is an organic solvent in which the predetermined polyphenylene ether is soluble with an aqueous solvent and a poor solvent containing hydrochloric acid to precipitate a polymer by reprecipitation, thereby obtaining a primarily purified predetermined polyphenylene ether; a drying step of drying the first purified predetermined polyphenylene ether obtained in the first purification step; a secondary purification step of contacting a solution containing the first purified polyphenylene ether and a good solvent, preferably a hydrophilic solvent, in which the polyphenylene ether is soluble, with a poor solvent containing an aqueous solvent (having a chlorine concentration of less than 500 ppm) to precipitate a polymer by reprecipitation, thereby obtaining a second purified polyphenylene ether; Includes.

[0121] Each step may be performed while adjusting the pressure or temperature as long as the effects of the present invention are not impaired.

[0122] In the purification step, filtration may be performed at any timing (for example, before the first purification step), and filtration may be performed multiple times.

[0123] (Primary purification process) The first purification step can be carried out according to a conventionally known method. For example, the first purification step can be carried out as follows. A solution of a given polyphenylene ether (polymer solution) to which a good solvent is added as necessary is dropped into an aqueous solvent and a poor solvent containing hydrochloric acid to reprecipitate the given polyphenylene ether (polymer solution). In the first purification step, the copper catalyst contained in the predetermined polyphenylene ether (polymer solution) is reacted with hydrochloric acid by stirring, and the efficiency of transferring the copper catalyst to the poor solvent can be improved. In the first purification step, the hydrochloric acid functions as a complexing agent for the copper catalyst. Next, the primarily purified predetermined polyphenylene ether is taken out by filtration. Furthermore, the primarily purified polyphenylene ether may be washed with a solvent or the like.

[0124] The good solvent is not particularly limited, and examples thereof include aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene, halogenated aromatic hydrocarbons such as chloroform, methylene chloride, chlorobenzene, dichlorobenzene, and trichlorobenzene, nitro compounds such as nitrobenzene, methyl ethyl ketone (MEK), cyclohexanone, tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), ethyl acetate, N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), propylene glycol monomethyl ether acetate (PMA), diethylene glycol monoethyl ether acetate (CA), 1,4-dioxane, and acetonitrile. Among these, a good solvent having affinity with the good solvent used in the polymerization step is preferred.

[0125] A poor solvent is a solvent in which a given polyphenylene ether has a relatively lower solubility than a good solvent. The poor solvent is not particularly limited as long as it is an aqueous solvent. The aqueous solvent may contain only water, or may be a mixture of water and an aqueous solvent (e.g., methanol, ethanol, isopropanol, acetone, etc.). Among them, an aqueous solvent that combines water and methanol is preferred because it has excellent work efficiency in the subsequent filtration step.

[0126] The conditions for dropping, stirring, and filtration are not particularly limited, and known conditions for carrying out the reprecipitation method or the like may be adopted.

[0127] The concentration of hydrochloric acid used is not particularly limited, and it is sufficient to make the concentration sufficient to react with the copper catalyst.

[0128] The solvent may contain a known chelating agent (eg, ethylenediamineacetic acid, disodium ethylenediamineacetate, diethylenetriaminepentaacetic acid, etc.).

[0129] (drying process) The drying in the drying step may be carried out according to a known method depending on the used solvent, etc. As an example, the drying step may be carried out by heating at −80 to 130° C. for 1 to 6 hours.

[0130] By carrying out the drying, it becomes possible to remove hydrochloric acid contained in the primary purified polyphenylene ether and to shorten the filtration time in the secondary purification step.

[0131] (Secondary purification process) The secondary purification step can be carried out according to a conventionally known method. For example, the secondary purification step can be carried out as follows. A solution in which a high concentration of a primary purified predetermined polyphenylene ether (polymer solution) is contained in a good solvent is dropped into a poor solvent containing an aqueous solvent to reprecipitate the predetermined polyphenylene ether. In the secondary purification step, the efficiency of transferring chlorine contained in the predetermined polyphenylene ether (polymer solution) to the poor solvent can be improved by stirring the solution. Next, the second purified predetermined polyphenylene ether is taken out by filtration or the like. The second purified predetermined polyphenylene ether may be further washed with a solvent or the like.

[0132] The good solvent is not particularly limited, and examples thereof include aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene, halogenated aromatic hydrocarbons such as chloroform, methylene chloride, chlorobenzene, dichlorobenzene, and trichlorobenzene, nitro compounds such as nitrobenzene, methyl ethyl ketone (MEK), cyclohexanone, tetrahydrofuran (THF), 2-methyltetrahydrofuran (2-MeTHF), ethyl acetate, N-methyl-2-pyrrolidone (NMP), N,N-dimethylformamide (DMF), propylene glycol monomethyl ether acetate (PMA), diethylene glycol monoethyl ether acetate (CA), 1,4-dioxane, and acetonitrile. Among them, it is preferable that the solvent has affinity (hydrophilicity) with the poor solvent (aqueous solvent), and examples thereof include N-methyl-2-pyrrolidone, tetrahydrofuran, 1,4-dioxane, and acetonitrile. In particular, tetrahydrofuran and NMP are more preferable because they have excellent solubility of a specific polyphenylene ether and excellent affinity with the poor solvent.

[0133] The solvent may contain a known chelating agent. Examples of the chelating agent include ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, hydroxylethylenediaminetriacetic acid, and salts thereof. By using a chelating agent in the second purification step, the copper catalyst that was not removed in the first purification step can be removed without leaving any residual chlorine.

[0134] A poor solvent is a solvent in which a given polyphenylene ether has a relatively lower solubility than a good solvent. The poor solvent is not particularly limited as long as it is an aqueous solvent. The aqueous solvent may contain only water, or may be a mixture of water and an aqueous solvent (e.g., methanol, ethanol, isopropanol, acetone, etc.). The chlorine concentration of the poor solvent is less than 500 ppm, preferably less than 100 ppm, more preferably less than 50 ppm, even more preferably less than 10 ppm, and particularly preferably 0 ppm (however, unavoidable chlorine content is permitted).

[0135] The conditions for dropping, stirring, and filtration are not particularly limited, and the conditions for carrying out a known reprecipitation method or the like may be adopted.

[0136] After the secondary purification step, a drying step may be further carried out, which can be carried out under the same conditions as the drying step after the primary purification step.

[0137] <<<<Curable composition>>>> The curable compositions of the present invention comprise a highly purified selected polyphenylene ether having a copper concentration of less than 100 ppm and a chlorine concentration of less than 500 ppm. The polyphenylene ether may be used alone or in combination of two or more kinds. Here, in the present invention, curing refers to one or more reactions including a self-crosslinking reaction of a specific polyphenylene ether in the curable composition, a crosslinking reaction between the specific polyphenylene ether and other components, and a crosslinking reaction between other components other than the specific polyphenylene ether. The curable composition may also contain other components within a range that does not impair the effects of the present invention. Each component will be described below.

[0138] <<Prescribed polyphenylene ether>> The predetermined polyphenylene ether constituting the curable composition of the present invention is as described above.

[0139] The content of the specific polyphenylene ether in the curable composition of the present invention is typically 5 to 30 mass % or 10 to 20 mass % based on the total solid content of the composition. From another viewpoint, the content of the specific polyphenylene ether in the curable composition is 20 to 60 mass % based on the total solid content of the composition.

[0140] The solid content in the curable composition means the components constituting the composition other than the solvent (particularly the organic solvent), or the mass or volume thereof.

[0141] <<Other ingredients>> Other components may include known components such as fillers (inorganic fillers and organic fillers such as PTFE powder), flame retardancy improvers (phosphorus-based compounds, etc.), cellulose nanofibers, cyanate ester resins, epoxy resins, phenol novolac resins, elastomers, dispersants, curing accelerators, crosslinking curing agents (crosslinking agents), polymerization initiators, adhesion promoters, and solvents.

[0142] <<<<Dry film, prepreg>>>> The dry film or prepreg of the present invention is obtained by coating or impregnating a substrate with the above-mentioned curable composition.

[0143] Examples of the substrate include metal foils such as copper foil, films such as polyimide films, polyester films, and polyethylene naphthalate (PEN) films, and fibers such as glass cloth and aramid fibers.

[0144] The dry film can be obtained, for example, by applying a curable composition onto a polyethylene terephthalate film, drying the composition, and laminating a polypropylene film, if necessary.

[0145] The prepreg can be obtained, for example, by impregnating a glass cloth with a curable composition and drying the same.

[0146] <<<<Cured product>>>> The cured product of the present invention can be obtained by curing the above-mentioned curable composition.

[0147] The method for obtaining a cured product from the curable composition is not particularly limited, and can be appropriately changed depending on the composition of the curable composition. As an example, after carrying out a step of coating the curable composition on a substrate as described above (for example, coating with an applicator, etc.), a drying step of drying the curable composition is carried out as necessary, and a thermal curing step of thermally crosslinking the polyphenylene ether by heating (for example, heating with an inert gas oven, a hot plate, a vacuum oven, a vacuum press, etc.) may be carried out. The conditions for carrying out each step (for example, coating thickness, drying temperature and time, heating temperature and time, etc.) may be appropriately changed depending on the composition and use of the curable composition.

[0148] <<<<Laminates>>>> The laminate of the present invention contains the above-mentioned cured product of the present invention and can be produced, for example, by using the above-mentioned prepreg.

[0149] More specifically, one or more prepregs of the present invention are stacked, and then a metal foil such as copper foil is stacked on both or just one of the upper and lower surfaces of the prepreg, and the resulting laminate is heated and pressurized to produce an integrated laminate having metal foil on both sides or just one side.

[0150] <<<<Electronic Components>>>> The electronic part of the present invention comprises the above-mentioned cured product of the present invention, and has excellent dielectric properties and heat resistance, and therefore can be used for various applications.

[0151] Its applications are not particularly limited, but preferred applications include large-capacity, high-speed communications such as those represented by the fifth-generation communication system (5G) and millimeter-wave radar for automotive ADAS (advanced driving systems). EXAMPLES

[0152] EXAMPLES Next, the present invention will be described in detail with reference to examples and comparative examples, but the present invention is not limited to these in any way.

[0153] <<<Synthesis and purification of PPE resin in Example 1>>> 0.5 g of di-μ-hydroxo-bis[(N,N,N',N'-tetramethylethylenediamine)copper(II)] chloride (Cu / TMEDA) and 0.6 mL of tetramethylethylenediamine (TMEDA) were added to a 1 L two-necked flask equipped with a reflux tube and a stirrer and stirred at 700 rpm. 19.8 g of 2,6-dimethylphenol and 2.42 g of 2-allylphenol, which are raw phenols, were dissolved in 0.3 L of toluene to prepare a raw material solution. This raw material solution was added to the flask and heated and stirred at 40°C for 6 hours at 700 rpm while bubbling oxygen gas. After the reaction was completed, the Cu catalyst was removed by suction filtration, and the reaction solution was dropped into a mixture of 1.2 L of methanol, 27 ml of water, and 4 mL of hydrochloric acid, and the mixture was stirred at 900 rpm at room temperature for 12 hours, and polyphenylene ether was recovered by suction filtration (primary purification step). The polyphenylene ether obtained in the first purification step was dried under reduced pressure at 80° C. for 4 hours (drying step). The solid polyphenylene ether obtained in the drying process was dissolved in 200 ml of NMP, dropped into a mixture of 0.6 L of methanol, 75 ml of water, and 0.9 g of EDTA-4Na, and stirred at 900 rpm at room temperature for 12 hours. The polyphenylene ether was then recovered by suction filtration (secondary purification process). The polyphenylene ether obtained in the second purification step was dried under reduced pressure at 100°C for 6 hours to obtain a branched PPE. The number average molecular weight of the branched PPE was 15,000 and the weight average molecular weight was 55,000. The slope of the conformation plot of the branched PPE was 0.33.

[0154] <<<Synthesis and purification of PPE resins in Examples 2-4 and Comparative Examples 1-4>>> The synthesis and purification of the PPE resins of Examples 2-4 and Comparative Examples 1-4 were carried out in the same manner as in Example 1, except that the type of poor solvent used in the first purification step was changed, the drying step was changed, and the types of good solvent and poor solvent used in the second purification step were changed to meet the conditions shown in the table.

[0155] The times required for the filtration in the first and second purification steps are shown in the table.

[0156] <<<Evaluation>>> <<Impurity concentration>> The copper and chlorine concentrations in each PPE resin were measured using the method described above. The copper and chlorine concentrations in each PPE resin are shown in the table below.

[0157] When the copper concentration was less than 20 ppm, it was evaluated as "A", when it was 20 ppm or more and less than 100 ppm, it was evaluated as "O", and when it was 100 ppm or more, it was evaluated as "X".

[0158] The chlorine concentration was evaluated as "◎" when it was less than 70 ppm, "◯" when it was 70 ppm or more and less than 500 ppm, and "×" when it was 500 ppm or more.

[0159] <<Filtration time>> In the filtration of the secondary purification step, filtration times of less than 40 minutes were evaluated as "◎", those of 40 minutes or more but less than 10 minutes as "○", and those of 100 minutes or more as "×".

[0160] [Table 1]

[0161] <Preparation of Curable Composition> 13.25 parts by mass of the PPE resin of Example 1, 13.25 parts by mass of TAIC (manufactured by Mitsubishi Chemical Corporation) as a cross-linking curing agent, 6.2 parts by mass of Tuftec H1051 (manufactured by Asahi Kasei Corporation) as an adhesion imparting agent, and 100 parts by mass of cyclohexanone were added and stirred, and 58.4 parts by mass of spherical silica (manufactured by Admatechs Co., Ltd.: product name "SC2500-SVJ") was further added as an inorganic filler, stirred, and then uniformly dispersed using a triple roll mill. Finally, 0.53 parts by mass of the peroxide α,α'-bis(t-butylperoxy-m-isopropyl)benzene (manufactured by NOF Corporation: product name "Perbutyl P") was added and stirred to prepare a curable composition containing the PPE resin of Example 1.

[0162] A curable composition containing the PPE resin of Comparative Example 3 was prepared in the same manner as in Example 1, except that the PPE resin of Example 1 was replaced with the PPE resin of Comparative Example 3.

[0163] <<Dielectric properties>> Cured products were prepared using the PPE resin of Example 1 and the PPE resin of Comparative Example 3, and the dielectric properties, that is, the relative dielectric constant Dk and the dielectric loss tangent Df, were measured according to the following method.

[0164] Each curable composition containing the PPE resin of Example 1 or Comparative Example 3 was applied to the shine side of a 18 μm thick copper foil with an applicator so that the thickness of the cured product was 50 μm, and then dried at 90° C. for 30 minutes in a hot air circulation drying oven. Next, after curing at 200° C. for 1 hour in an inert oven, the copper foil was etched to obtain a cured product (cured film) made of each composition.

[0165] The prepared cured film was cut into a length of 80 mm, width of 45 mm, and thickness of 50 μm to be used as a test piece, and the relative dielectric constant Dk and dielectric loss tangent Df were 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.

[0166] <Dielectric properties test results> Cured product using PPE resin of Example 1 Dk: 3.0, Df: 0.0015 Cured product using PPE resin of Comparative Example 3 Dk: 3.0, Df: 0.0016

[0167] <<Insulation reliability>> A substrate for HAST was fabricated using the PPE resin of Example 1 and the PPE resin of Comparative Example 3, and the insulation reliability was evaluated by HAST (High Accelerated Stress Test) for 500 hours.

[0168] <Fabrication of Substrate for HAST> Each curable composition containing the PPE resin of Example 1 or Comparative Example 3 was applied to a roughened copper-clad BT (bismaleimide triazine) substrate with an applicator to a dry film thickness of 60 μm, and dried in a hot air circulation drying oven at 90 °C for 30 minutes. Next, on the dried film of each composition, FV-WS (HVLP foil) manufactured by Furukawa Electric Co., Ltd. was placed as a copper foil so that the roughened surface was in contact, and laminated using a vacuum laminator (hot plate temperature: 100 °C, vacuum drawing: 30 s, pressurization: 30 s (0.5 MPa)). Thereafter, a laminate having a cured product layer and a copper foil made of each composition was obtained by curing at 200 °C for 1 h in an inert oven. Thereafter, the surface copper foil was etched into a circle with a diameter of 10 mm using an etching solution for printed circuit boards manufactured by Sunhayato, and a substrate for HAST was fabricated.

[0169] <Test Conditions for Insulation Resistance Value> In each substrate for HAST, the surface (circular with a diameter of 10 mm) copper foil was used as the anode, and the copper foil surface of the copper-clad BT substrate was used as the cathode. Using a HAST device (MIGRATION TESTER MODEL MIG-8600B manufactured by IMV) and a chamber (HASTEST (registered trademark) MODEL PC-R8D manufactured by Hirayama), the test was conducted under the conditions: 110 °C / 85% RH / 50 V / 500 h.

[0170] <Test Results of Insulation Resistance Value> The resistance values when the voltage was applied for 500 hours were as follows. Substrate having a cured product using the PPE resin of Example 1 1.5×10 11 (Ω) Substrate having a cured product using the PPE resin of Comparative Example 3 1.5×10 9 (Ω)

[0171] Thus, it was confirmed that the cured product using the PPE resin of Example 1 had both low dielectric properties and excellent insulation reliability, compared to the cured product using the PPE resin of Comparative Example 3.

Claims

1. A polyphenylene ether-containing composition obtained from a raw material phenol containing a phenol satisfying at least condition 1, the composition containing a polyphenylene ether having a slope calculated in a conformation plot of less than 0.6, The copper concentration is less than 100 ppm; The chlorine concentration is less than 500 ppm; A polyphenylene ether-containing composition, characterized in that the phenols satisfying at least condition 1 are composed of a phenol (a) represented by the following formula (1) and / or a phenol (b) represented by the following formula (2): (Condition 1) Contains hydrogen atoms at the ortho and para positions [Formula 1] (In the formula (1), R １ ~R ３ is a hydrogen atom, or an alkyl, alkenyl, or alkynyl group having 1 to 15 carbon atoms. １ ~R ３ At least one of is an alkenyl group or an alkynyl group. [chemical 2] (In the formula (2), R ４ ~R ６ is a hydrogen atom or an alkyl group having 1 to 15 carbon atoms.

2. A curable composition, wherein the phenols satisfying at least condition 1 include the phenols (a).

3. A dry film or prepreg obtained by coating or impregnating a substrate with the polyphenylene ether-containing composition according to claim 2.

4. A cured product obtained by curing the polyphenylene ether-containing composition according to claim 2.

5. A laminate comprising the cured product according to claim 4.

6. An electronic part comprising the cured product according to claim 4.

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