Polyphenylene ether, method for producing the same, thermosetting composition, prepreg, and laminate

Abstract

The present invention aims to provide a polyphenylene ether having excellent solubility in a general-purpose ketone-based solvent and a production method thereof. It also aims to provide a thermosetting composition, a prepreg, and a laminate each using the polyphenylene ether. The polyphenylene ether of the present invention is characterized by containing 5 to 85 mol% of repeating units derived from a phenol of formula (1) and 15 to 95 mol% of repeating units derived from a phenol of formula (2) relative to 100 mol% of the total of the repeating units derived from the phenol of formula (1) and the repeating units derived from the phenol of formula (2), and having a specific viscosity (ηsp / c) of 0.03 to 0.30 dL / g measured in a 0.5 g / dL concentration chloroform solution at 30°C.

Description

Technical Field

[0001] This invention relates to polyphenylene oxide, its manufacturing method, thermosetting compositions, prepregs, and laminates. Background Technology

[0002] Polyphenylene oxide (hereinafter also referred to as "PPE") possesses excellent high-frequency properties, flame retardancy, and heat resistance, and is therefore widely used as a material for products / components in the electrical / electronic, automotive, and food / packaging industries, as well as in various other industrial materials. In recent years, in particular, its low dielectric properties and heat resistance have facilitated its application as a substrate material and other electronic materials, as well as as a modifier in various other applications.

[0003] However, high-molecular-weight polyphenylene ethers, typically containing repeating units derived from monophenols such as 2,6-dimethylphenol, are soluble in highly toxic solvents like chloroform, but they are difficult to dissolve in high concentrations in aromatic solvents such as toluene (known as good solvents) at room temperature, and are insoluble in ketone solvents such as methyl ethyl ketone. Therefore, for example, when used as a wiring board material, it is difficult to process with resin varnish solutions such as toluene and methyl ethyl ketone.

[0004] Patent document 1 discloses that low molecular weight polyphenylene ether with a specific particle size has excellent solubility in solvents such as methyl ethyl ketone.

[0005] In addition, Patent Document 2 describes a modified polyphenylene ether compound having a defined polyphenylene ether moiety in its molecular structure and having at least one p-vinylbenzyl, m-vinylbenzyl, etc., at its molecular end.

[0006] In addition, Patent Document 3 describes a modified polymer having a polyphenylene ether moiety within its molecular structure and a methacryloyl group at its molecular end.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2004-99824

[0010] Patent Document 2: Japanese Patent Application Publication No. 2004-339328

[0011] Patent Document 3: Japanese Patent Publication No. 2008-510059 Summary of the Invention

[0012] The problem that the invention aims to solve

[0013] As described above, Patent Documents 1-3 disclose methods for manufacturing polyphenylene ethers (PPEs) by reducing their molecular weight to improve their solvent solubility. However, simply reducing the molecular weight of PPEs is insufficient to significantly improve their solubility in common ketone solvents such as methyl ethyl ketone at room temperature. A method is particularly needed to improve their long-term solvent solubility in ketone solvents.

[0014] The present invention was made in view of the above-mentioned problems, and its object is to provide a polyphenylene ether with excellent solubility in common ketone solvents and a method for manufacturing the same. It also aims to provide thermosetting compositions, prepregs, and laminates using this polyphenylene ether.

[0015] Methods for solving problems

[0016] That is, the present invention is as follows. [1]

[0018] A polyphenylene ether, characterized in that,

[0019] The total 100 mol% of phenol repeating units derived from formula (1) and formula (2) includes 5 to 85 mol% of phenol repeating units derived from formula (1) and 15 to 95 mol% of phenol repeating units derived from formula (2).

[0020] The specific viscosity (ηsp / c) measured in a chloroform solution with a concentration of 0.5 g / dL at 30°C was 0.03–0.30 dL / g.

[0021] [Chemistry 1]

[0022]

[0023] (In equation (1), R) 11 Each is independently a saturated hydrocarbon group with 1 to 6 carbon atoms, with or without substituents; an aryl group with 6 to 12 carbon atoms, with or without substituents; or a halogen atom, R. 12 Each of the following groups is independently a hydrogen atom, a hydrocarbon group with 1 to 6 carbon atoms (with or without substituents), an aryl group with 6 to 12 carbon atoms (with or without substituents), or a halogen atom.

[0024] [Chemistry 2]

[0025]

[0026] (In equation (2), R) 22 Each of the following is independently a hydrogen atom, a saturated or unsaturated hydrocarbon group with or without substituents (1-20 carbon atoms), an aryl group with or without substituents (6-12 carbon atoms), or a halogen atom, with two R atoms.22 R is not simultaneously a hydrogen atom. 21 It is the partial structure represented by the following formula (3).

[0027] [Chemistry 3]

[0028]

[0029] (In equation (3), R) 31 Each is independently a straight-chain alkyl group having 1 to 8 carbon atoms, with or without substituents, or with 2 R groups. 31 A cyclic alkyl structure with 1 to 8 carbon atoms bonded together, R 32 Each is an alkylene group having 1 to 8 carbon atoms, with or without substituents; b is independently 0 or 1; R 33 It can be a hydrogen atom, an alkyl group having 1 to 8 carbon atoms with or without substituents, or a phenyl group having or without substituents. [2]

[0031] As described in [1], the polyphenylene ether, wherein the structure represented by the above formula (3) is tert-butyl. [3]

[0033] Polyphenylene ether as described in [1] or [2], wherein the average number of hydroxyl groups is less than 2.5 per molecule. [4]

[0035] The polyphenylene ether as described in any one of [1] to [3] has an average number of hydroxyl groups of less than 0.2 per molecule. [5]

[0037] The polyphenylene ether as described in any one of [1] to [4] has at least one partial structure selected from the group consisting of formula (4), formula (5), formula (6) and formula (7) below, with an average number of hydroxyl groups less than 0.2 per molecule.

[0038] [Chemistry 4]

[0039]

[0040] [Chemistry 5]

[0041]

[0042] [Chemistry 6]

[0043]

[0044] (In equation (6), R) 6It consists of a hydrogen atom or a saturated or unsaturated hydrocarbon group with 1 to 10 carbon atoms. These saturated or unsaturated hydrocarbons may also contain substituents, provided they meet the requirement of having 1 to 10 carbon atoms.

[0045] [Chemistry 7]

[0046]

[0047] (In equation (7), R) 7 It is a divalent hydrocarbon group with 1 to 10 carbon atoms, either saturated or unsaturated. This saturated or unsaturated divalent hydrocarbon can also contain substituents, provided it satisfies the condition of 1 to 10 carbon atoms. R 8 It consists of a hydrogen atom or a saturated or unsaturated hydrocarbon group with 1 to 10 carbon atoms. The saturated or unsaturated hydrocarbon may also contain substituents, provided it satisfies the requirement of having 1 to 10 carbon atoms. [6]

[0049] The polyphenylene ether as described in any one of [1] to [5] comprises a repeating unit of a monophenol having at least one unsaturated hydrocarbon group on a carbon atom adjacent to the carbon atom bonded to the hydroxyl group of the phenol. [7]

[0051] The polyphenylene ether described in [6] is wherein the monophenol is 2-allylphenol or 2-methyl-6-allylphenol. [8]

[0053] A method for manufacturing polyphenylene ether, which is the method for manufacturing polyphenylene ether described in any one of [1] to [7], comprising the steps of oxidative polymerization of phenol of formula (1) and phenol of formula (2) described above. [9]

[0055] A polyphenylene ether solution comprising any one of [1] to [7], and a ketone solvent.

[10]

[0057] A thermosetting composition comprising any one of [1] to [7] polyphenylene ether.

[11]

[0059] A prepreg comprising a substrate and the thermosetting composition described in

[10] .

[12]

[0061] The prepreg as described in

[11] , wherein the substrate is glass cloth.

[13]

[0063] A laminate characterized in that it comprises a cured prepreg as described in

[11] or

[12] , and a metal foil.

[0064] The effects of the invention

[0065] According to the present invention, a polyphenylene ether with excellent solubility in common ketone solvents and a method thereof can be provided. Thermosetting compositions, prepregs, and laminates using the polyphenylene ether can also be provided. Detailed Implementation

[0066] The following provides a detailed description of specific embodiments of the present invention (hereinafter referred to as "this embodiment"). This embodiment is merely an example to illustrate the present invention, and the present invention is not limited to this embodiment; it can be suitably modified and implemented within the scope of its key points.

[0067] In this embodiment, polyphenylene ether formed by modifying some or all of the hydroxyl groups contained in the polyphenylene ether is sometimes simply referred to as "polyphenylene ether". Therefore, when referred to as "polyphenylene ether", it includes both unmodified polyphenylene ether and modified polyphenylene ether, unless there is a particular contradiction.

[0068] It should be noted that in this specification, A (numerical value) to B (numerical value) refers to values ​​above A and below B. Additionally, examples of substituents in this specification include saturated or unsaturated hydrocarbon groups with 1 to 10 carbon atoms, aryl groups with 6 to 10 carbon atoms, and halogen atoms.

[0069] <Polyphenylene ether>

[0070] The polyphenylene ether of this embodiment contains at least repeating units of phenol derived from formula (1) and repeating units of phenol derived from formula (2). The repeating units in the compound may also consist only of repeating units of phenol derived from formula (1) and repeating units of phenol derived from formula (2).

[0071] [Chemistry 8]

[0072]

[0073] (In equation (1), R) 11 Each is independently a saturated hydrocarbon group with 1 to 6 carbon atoms, with or without substituents; an aryl group with 6 to 12 carbon atoms, with or without substituents; or a halogen atom, R. 12 Each of the following groups is independently a hydrogen atom, a hydrocarbon group with 1 to 6 carbon atoms (with or without substituents), an aryl group with 6 to 12 carbon atoms (with or without substituents), or a halogen atom.

[0074] [Chemistry 9]

[0075]

[0076] (In equation (2), R)22 Each of the following is independently a hydrogen atom, a saturated or unsaturated hydrocarbon group with or without substituents (1-20 carbon atoms), an aryl group with or without substituents (6-12 carbon atoms), or a halogen atom, with two R atoms. 22 R is not simultaneously a hydrogen atom. 21 It is the partial structure represented by the following formula (3).

[0077] [Chemistry 10]

[0078]

[0079] (In equation (3), R) 31 Each is independently a straight-chain alkyl group having 1 to 8 carbon atoms, with or without substituents, or with 2 R groups. 31 A cyclic alkyl structure with 1 to 8 carbon atoms bonded together, R 32 Each is an alkylene group having 1 to 8 carbon atoms, with or without substituents; b is independently 0 or 1; R 33 It is any one of hydrogen atoms, an alkyl group having 1 to 8 carbon atoms with or without substituents, or a phenyl group having or without substituents.

[0080] In the above formula (1), R 11 Each of the two R groups is preferably a saturated hydrocarbon group with 1 to 6 carbon atoms or an aryl group with 6 to 12 carbon atoms, more preferably methyl or phenyl, and even more preferably methyl. In formula (1), the two R groups are... 11 Ideally, all should have the same structure.

[0081] As mentioned above, R 11 Substituents in saturated hydrocarbon groups with 1 to 6 carbon atoms and aryl groups with 6 to 12 carbon atoms can be saturated or unsaturated hydrocarbon groups with 1 to 10 carbon atoms, aryl groups with 6 to 10 carbon atoms, and halogen atoms.

[0082] In the above formula (1), R 12 Each of the two R groups is preferably a hydrocarbon group with 1 to 6 carbon atoms, and more preferably a hydrogen atom or a methyl group. In formula (1), the two R groups are... 12 The preferred components are different, and more preferably one component is a hydrogen atom and the other is a hydrocarbon group with 1 to 6 carbon atoms (preferably methyl).

[0083] As mentioned above, R 12 Substituents in hydrocarbon groups with 1 to 6 carbon atoms and aryl groups with 6 to 12 carbon atoms can be saturated or unsaturated hydrocarbon groups with 1 to 10 carbon atoms, aryl groups with 6 to 10 carbon atoms, and halogen atoms.

[0084] In equation (2) above, R 22Each of the following is preferably a hydrogen atom, a saturated or unsaturated hydrocarbon group having 1 to 15 carbon atoms, or an aryl group having 6 to 12 carbon atoms that may be substituted with an alkyl group having 1 to 6 carbon atoms; more preferably a hydrogen atom, a hydrocarbon group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms that may be substituted with an alkyl group having 1 to 6 carbon atoms; and even more preferably a hydrogen atom or a methyl group. In formula (2), the two R groups... 22 The preferred components are different, and more preferably one component is a hydrogen atom and the other is a hydrocarbon group with 1 to 6 carbon atoms (preferably methyl).

[0085] As mentioned above, R 22 Substituents in saturated or unsaturated hydrocarbon groups with 1 to 20 carbon atoms and aryl groups with 6 to 12 carbon atoms can be categorized as saturated or unsaturated hydrocarbon groups with 1 to 10 carbon atoms, aryl groups with 6 to 10 carbon atoms, and halogen atoms.

[0086] As part of the structure represented by the above formula (3), it is preferred to include groups containing secondary carbon and / or tertiary carbon, such as isopropyl, isobutyl, sec-butyl, tert-butyl, tert-pentyl, 2,2-dimethylpropyl, cyclohexyl, structures having phenyl at their ends, etc., more preferably tert-butyl, cyclohexyl, and even more preferably tert-butyl.

[0087] It should be noted that, as mentioned above, R 31 Substituents in straight-chain alkyl groups having 1 to 8 carbon atoms, and the above R 32 Substituents in alkylene groups having 1 to 8 carbon atoms, and the aforementioned R 33 Substituents in alkyl and phenyl groups having 1 to 8 carbon atoms can be saturated or unsaturated hydrocarbon groups having 1 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, and halogen atoms.

[0088] In this embodiment, the structure of polyphenylene ether (PPE) can be identified by analysis using methods such as NMR and mass spectrometry. As a specific method for identifying the structure of PPE, field resolution mass spectrometry (FD-MS), which is known to be less prone to fragmentation, can be performed, and repeating units can be deduced by analyzing the intervals of the detected ions. Alternatively, a method can be employed to deduce the structure of PPE by combining peak analysis of fragment ions using electron ionization (EI) with NMR-based structural analysis.

[0089] In the polyphenylene ether of this embodiment, relative to a total of 100 mol% of repeating units of phenol derived from formula (1) and repeating units of phenol derived from formula (2), it contains 5 to 85 mol% of repeating units of phenol derived from formula (1) and 15 to 95 mol% of repeating units of phenol derived from formula (2). From the viewpoint of obtaining a polyphenylene ether with excellent solvent solubility and low dielectric loss tangent, the repeating units of phenol derived from formula (2) are preferably 18 mol% or more, more preferably 20 mol% or more. From the same viewpoint, the repeating units of phenol derived from formula (1) are preferably 82 mol% or less, more preferably 80 mol% or less.

[0090] The repeating unit of phenol derived from formula (1) contained in the polyphenylene ether of this embodiment may be one or more repeating units. In addition, the repeating unit of phenol derived from formula (2) contained in the polyphenylene ether of this embodiment may be one or more repeating units.

[0091] The total molar percentage of repeating units of phenol derived from formula (1) and repeating units of phenol derived from formula (2) is preferably 75 mol% or more, more preferably 90 mol% or more, and even more preferably 95 mol% or more, relative to 100 mol% of monomer units (e.g., all monomer units derived from phenol contained in polyphenylene ether of this embodiment).

[0092] The ratio of repeating units of phenol derived from formula (1) to repeating units of phenol derived from formula (2) can be used, for example, by... 1 H NMR, 13 The determination can be made using analytical methods such as C NMR, or more specifically, it can be determined using the methods described in the examples below.

[0093] Since the phenol of formula (1) does not have unsubstituted ortho positions (i.e., since no hydrogen atoms are bonded to the two ortho carbon atoms of the carbon atom bonded to the hydroxyl group), it can react with other phenolic monomers only at the carbon atom in the para position of the phenolic hydroxyl group. Therefore, the repeating unit derived from formula (1) contains repeating units having the structure of formula (8) below.

[0094] [Chemistry 11]

[0095]

[0096] (In equation (8), R) 11 and R 12 Same as in equation (1).

[0097] In the phenol of formula (2), except for the phenolic hydroxyl group, it can react with other phenolic monomers at either the ortho or para position. Therefore, the repeating unit of the phenol derived from formula (2) has a monomer unit of formula (9) or formula (10) or a combination thereof.

[0098] [Chemistry 12]

[0099]

[0100] [Chemistry 13]

[0101]

[0102] R in equations (9) and (10) 21 R 22 Same as in equation (2).

[0103] In this embodiment, the specific viscosity of the polyphenylene ether measured in a chloroform solution with a concentration of 0.5 g / dL at 30°C is preferably 0.03 to 0.30 dL / g, more preferably 0.06 to 0.30 dL / g.

[0104] The specific viscosity can be appropriately selected according to the application. For example, when it is desirable to further improve the flowability when dissolved in the solvent for making varnish during the application process of the substrate material, a low specific viscosity is preferred.

[0105] Specific viscosity can be determined using the methods described in the examples below.

[0106] The polyphenylene ether in this embodiment may also contain, in addition to the phenol of formula (1) and the phenol of formula (2), a terpolymer with a structure derived from a diphenol of formula (11) as an impurity (in this specification, it is sometimes simply referred to as "impurity A"). The polyphenylene ether in this embodiment may be a mixture of the above-described polyphenylene ether and the above-described impurity A. The molar percentage of impurity A relative to 100 mol% of the polyphenylene ether in this embodiment is preferably 10 mol% or less, more preferably 5 mol% or less.

[0107] The aforementioned impurity A can be synthesized, for example, as a terpolymer of a structure containing a diphenol source of formula (11) by reacting the following formula (12), which is produced as a byproduct during the oxidative polymerization of monophenol, with polyphenylene ether composed of monophenol.

[0108] [Chemistry 14]

[0109]

[0110] (In equation (11), R) 11 and R 12 Same as in equation (1). z is 0 or 1, Y is

[0111] [Chemistry 15]

[0112] -O-,-S-,

[0113] (where R is in the formula) 41 Each of the following is independently any one of a hydrocarbon group having 1 to 6 carbon atoms (with or without substituents), an aryl group having 6 to 12 carbon atoms (with or without substituents), and a halogen atom.

[0114] [Chemistry 16]

[0115]

[0116] (In equation (12), R) 11 and R 12 Same as in equation (1).

[0117] Regarding the average number of hydroxyl groups in the polyphenylene ether of this embodiment, it is preferably less than 2.5 hydroxyl groups / molecule, more preferably less than 2.2 hydroxyl groups / molecule, and even more preferably less than 2.0 hydroxyl groups / molecule in the case of unmodified polyphenylene ether. If the average number of hydroxyl groups exceeds 2.5 hydroxyl groups / molecule, it means that it is a multi-branched unmodified polyphenylene ether with incomplete structural control.

[0118] The average number of hydroxyl groups can be determined by the method described in the examples below.

[0119] In this embodiment, the polyphenylene ether can be a modified polyphenylene ether in which the hydroxyl groups contained in the polyphenylene ether are modified into functional groups (e.g., functional groups containing unsaturated carbon bonds). In the case of modified polyphenylene ether, it is preferable that the average number of hydroxyl groups is less than 0.2 per molecule, more preferably less than 0.1 per molecule, and even more preferably less than 0.01 per molecule.

[0120] The polyphenylene ether in this embodiment may have at least one partial structure selected from the group consisting of formulas (4), (5), (6) and (7) below.

[0121] [Chemistry 17]

[0122]

[0123] [Chemistry 18]

[0124]

[0125] [Chemistry 19]

[0126]

[0127] (In equation (6), R)6 It consists of a hydrogen atom or a saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms. The aforementioned saturated or unsaturated hydrocarbons can be in R... 6 (The total number of carbon atoms is in the range of 1 to 10, and it contains substituents.)

[0128] [Chemistry 20]

[0129]

[0130] (In equation (7), R) 7 It is a saturated or unsaturated divalent hydrocarbon group with 1 to 10 carbon atoms. The aforementioned saturated or unsaturated divalent hydrocarbons can be in R... 7 The total number of carbon atoms is in the range of 1 to 10, and it contains substituents, R 8 It consists of a hydrogen atom or a saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms. This saturated or unsaturated hydrocarbon can be in the form of R... 8 (The total number of carbon atoms is in the range of 1 to 10, and it contains substituents.)

[0131] It should be noted that the partial structure represented by at least one of the groups selected from the above formulas (4), (5), (6), and (7) can be directly bonded to the hydroxyl groups contained in the polyphenylene ether.

[0132] The ratio of repeating units of phenol derived from formula (1) to repeating units of phenol derived from formula (2) contained in a modified polyphenylene ether having a partial structure represented by at least one of the group consisting of formulas (4), (5), (6), and (7) above can be used, for example, by using... 1 H NMR, 13 The determination can be made using analytical methods such as C NMR, or more specifically, it can be determined using the methods described in the examples below.

[0133] The polyphenylene ether in this embodiment may be a monohydric phenol having at least one unsaturated hydrocarbon group on the carbon atom adjacent to the carbon atom bonded to the hydroxyl group of the phenol. In the aforementioned monohydric phenol, the unsaturated hydrocarbon group bonded to the carbon atom adjacent to the carbon atom bonded to the hydroxyl group of the phenol is preferably one. The unsaturated hydrocarbon group may be bonded to one of each of the two adjacent carbon atoms of the carbon atom bonded to the hydroxyl group of the monohydric phenol, or it may be bonded to one adjacent carbon atom. It should be noted that the aforementioned monohydric phenol having at least one unsaturated hydrocarbon group on the carbon atom adjacent to the carbon atom bonded to the hydroxyl group of the phenol refers to a monohydric phenol different from the phenol of formula (1) or the phenol of formula (2) above.

[0134] The unsaturated hydrocarbon group is preferably an unsaturated hydrocarbon group with 3 to 10 carbon atoms, and more preferably an unsaturated hydrocarbon group with 3 to 5 carbon atoms. Examples of such unsaturated hydrocarbon groups include alkenyl (e.g., vinyl, allyl, etc.) and alkynyl (e.g., ethynyl, 1-propynyl, 2-propynyl, etc.).

[0135] The unsaturated hydrocarbons mentioned above can also have substituents as long as they meet the condition of having 3 to 10 carbon atoms.

[0136] The introduction rate of monophenol having at least one unsaturated hydrocarbon group on the carbon atom adjacent to the carbon atom bonded to the hydroxyl group of phenol can be appropriately adjusted to adjust the number of curable functional groups. The total amount of monophenol having at least one unsaturated hydrocarbon group on the carbon atom adjacent to the carbon atom bonded to the hydroxyl group of phenol is preferably 0.1 to 30 mol%, more preferably 0.1 to 25 mol%, relative to the total amount of phenol of formula (1) and monophenol having at least one unsaturated hydrocarbon group on the carbon atom adjacent to the carbon atom bonded to the hydroxyl group of phenol.

[0137] The molar ratio of the repeating units of phenol derived from formula (1) in the polyphenylene ether of this embodiment to the repeating units of monophenol derived from phenol having at least one unsaturated hydrocarbon group on the carbon atom adjacent to the carbon atom bonded to the carbon atom of the hydroxyl group of phenol is preferably 0.1 to 40 mol%, more preferably 0.1 to 10 mol%, as the total of the repeating units of monophenol derived from phenol having at least one unsaturated hydrocarbon group on the carbon atom adjacent to the carbon atom bonded to the carbon atom of the hydroxyl group of phenol.

[0138] <Manufacturing Method of Polyphenylene Ether>

[0139] The polyphenylene ether of this embodiment is obtained, for example, by a method including at least a step of oxidative polymerization of the monophenolic compounds represented by formulas (1) and (2) above. In the above-described oxidative polymerization step, it is preferable to oxidatively polymerize a raw material containing at least the phenol of formula (1) and the phenol of formula (2).

[0140] Examples of monophenol compounds represented by formula (1) above include 2,6-dimethylphenol, 2-methyl-6-ethylphenol, 2,6-diethylphenol, 2-ethyl-6-n-propylphenol, 2-methyl-6-chlorophenol, 2-methyl-6-bromophenol, 2-methyl-6-n-propylphenol, 2-ethyl-6-bromophenol, 2-methyl-6-n-butylphenol, 2,6-di-n-propylphenol, 2- Ethyl-6-chlorophenol, 2-methyl-6-phenylphenol, 2,6-diphenylphenol, 2-methyl-6-tolylphenol, 2,6-xylylphenol, 2,3,6-trimethylphenol, 2,3-diethyl-6-n-propylphenol, 2,3,6-tributylphenol, 2,6-di-n-butyl-3-methylphenol, 2,6-dimethyl-3-n-butylphenol, 2,6-dimethyl-3-tert-butylphenol, etc. Among these, 2,6-dimethylphenol, 2,3,6-trimethylphenol, and 2,6-diphenylphenol are preferred, especially due to their low cost and ease of availability.

[0141] The monophenol compound represented by formula (1) above can be used alone or in combination of two or more.

[0142] Examples of monophenol compounds represented by formula (2) above include 2-isopropyl-5-methylphenol, 2-cyclohexyl-5-methylphenol, 2-tert-butyl-5-methylphenol, and 2-isobutyl-5-methylphenol. From the viewpoint of suppressing multibranching and gelation, 2-tert-butyl-5-methylphenol and 2-cyclohexyl-5-methylphenol, which are bulky substituents, are more preferred.

[0143] The monophenol compound represented by formula (2) above can be used alone or in combination of two or more.

[0144] The above-mentioned oxidative polymerization process can be, for example, a process of oxidative polymerization of a monophenolic raw material that contains at least one unsaturated hydrocarbon group on the carbon atom adjacent to the carbon atom bonded to the hydroxyl group of phenol, in addition to the phenol of formula (1) and the phenol of formula (2) above.

[0145] As a monohydric phenol having at least one unsaturated hydrocarbon group on the carbon atom adjacent to the carbon atom bonded to the hydroxyl group of phenol, it is preferably a monohydric phenol having at least one (preferably one) unsaturated hydrocarbon group bonded to the aforementioned adjacent carbon atom and hydrogen atoms bonded to the carbon atoms at the meta and para positions, more preferably 2-allylphenol or 2-allyl-6-methylphenol, and even more preferably 2-allylphenol.

[0146] The monohydric phenols described above, which have at least one unsaturated hydrocarbon group on the carbon atom adjacent to the carbon atom bonded to the hydroxyl group of phenol, can be used alone or in combination with two or more.

[0147] Typically, since the oxidative polymerization of phenols with hydrogen atoms in the ortho position (e.g., 2-methylphenol, 2,5-dimethylphenol, 2-phenylphenol) can also form ether bonds in the ortho position, it is difficult to control the bonding position of phenol compounds during oxidative polymerization, resulting in high molecular weight polymers with an average number of hydroxyl groups of 3 or more per molecule that are polymerized into branched structures, ultimately producing a gel component that is insoluble in solvents (refer to the oxidative polymerization of 2,5-dimethylphenol and 2,6-dimethylphenol in Reference Example 1 below).

[0148] On the other hand, when using the phenol represented by the above formula (2) with a large volume substituent on one side, even if there is a hydrogen atom on the opposite side, the bonding position of the phenol compound during oxidative polymerization can be controlled, and polyphenylene ether with an average of less than 2.5 hydroxyl groups per molecule can be obtained.

[0149] Furthermore, when using phenol represented by the above formula (2) with a large substituent at one of the adjacent positions, and using a monophenol with a non-large substituent (e.g., hydrogen atom, allyl, methyl, ethyl, methoxy, etc.) at the adjacent position of the oxygen atom of phenol as the third component, it is also possible to obtain polyphenylene ether that does not undergo gelation and has an average of less than 2.5 hydroxyl groups per molecule.

[0150] In this embodiment, the molecular weight of the polyphenylene ether can be adjusted by the molar ratio of the repeating unit derived from formula (2) to the total of the repeating units derived from formula (1) and formula (2). That is, when the molar ratio of the repeating unit derived from formula (2) is high, the achieved molecular weight (specific viscosity) can be reduced, and when the molar ratio of the repeating unit derived from formula (2) is low, the molecular weight (specific viscosity) can be adjusted to be higher. The reason for this is not yet clear, but it is speculated that the high molecular weight is suppressed by the large volume substitution at the ortho position of formula (2).

[0151] (Oxidative polymerization process)

[0152] Here, in the method for manufacturing polyphenylene ether, in the oxidative polymerization step, an aromatic solvent that is a good solvent for polyphenylene ether can be used as the polymerization solvent.

[0153] Here, a good solvent for polyphenylene ether (PPE) refers to a solvent that can dissolve PPE. Examples of such solvents include aromatic hydrocarbons such as benzene, toluene, xylene (including isomers of o-xylene, m-xylene, and p-xylene), and ethylbenzene; halogenated hydrocarbons such as chlorobenzene and dichlorobenzene; nitro compounds such as nitrobenzene; and so on.

[0154] As the polymerization catalyst used in this embodiment, a known catalyst system commonly used in the manufacture of polyphenylene ether can be used. Commonly known catalyst systems include those consisting of a transition metal ion with redox capabilities and an amine compound capable of forming a complex with that transition metal ion, such as catalyst systems consisting of copper compounds and amine compounds, catalyst systems consisting of manganese compounds and amine compounds, and catalyst systems consisting of cobalt compounds and amine compounds. Since the polymerization reaction proceeds efficiently under slightly alkaline conditions, a small amount of alkali or further amine compounds may be added.

[0155] In this embodiment, the catalyst suitable for polymerization is a catalyst composed of copper compounds, halides and amine compounds that are components of the catalyst, and more preferably a catalyst containing a diamine compound represented by the following formula (13) as an amine compound.

[0156] [Chemistry 21]

[0157]

[0158] In equation (13), R 14 R 15 R 16 R 17 Each is an independent hydrogen atom or a straight-chain or branched alkyl group having 1 to 6 carbon atoms, and not all of them are hydrogen atoms simultaneously. R 18 It is a straight-chain alkylene group with 2 to 5 carbon atoms or a methyl-branched alkylene group.

[0159] Examples of copper compounds that form the catalyst components described above are given here. Suitable copper compounds can be monovalent copper compounds, divalent copper compounds, or mixtures thereof. Examples of divalent copper compounds include copper chloride, copper bromide, copper sulfate, and copper nitrate. Examples of monovalent copper compounds include cuprous chloride, cuprous bromide, cuprous sulfate, and cuprous nitrate. Among these, cuprous chloride, copper chloride, cuprous bromide, and copper bromide are particularly preferred metal compounds. Furthermore, these copper salts can also be synthesized in use from oxides (e.g., cuprous oxide), carbonates, hydroxides, etc., with the corresponding halogens or acids. A commonly used method is the method described above, which involves mixing cuprous oxide with hydrogen halide (or a solution of hydrogen halide).

[0160] Examples of halides include hydrogen chloride, hydrogen bromide, hydrogen iodide, sodium chloride, sodium bromide, sodium iodide, potassium chloride, potassium bromide, potassium iodide, tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium iodide, tetraethylammonium chloride, tetraethylammonium bromide, and tetraethylammonium iodide. Furthermore, they can be used in the form of aqueous solutions or solutions using suitable solvents. These halides can be used alone or in combination of two or more. Preferred halides are aqueous solutions of hydrogen chloride and hydrogen bromide.

[0161] The amount of these compounds is not particularly limited, but is preferably more than 2 to 20 times the molar amount of copper atoms, calculated in terms of halogen atoms. The amount of copper atoms is preferably in the range of 0.02 to 0.6 moles relative to 100 moles of phenol compound added to the polymerization reaction.

[0162] Next, examples of diamine compounds that are catalyst components are listed. For example, N,N,N',N'-tetramethylethylenediamine, N,N,N'-trimethylethylenediamine, N,N'-dimethylethylenediamine, N,N-dimethylethylenediamine, N-methylethylenediamine, N,N,N',N'-tetraethylethylenediamine, N,N,N'-triethylethylenediamine, N,N'-diethylethylenediamine, N,N-diethylethylenediamine, N,N-diethylethylenediamine, N-ethylethylenediamine, N,N-dimethyl-N'-ethylethylenediamine, N,N'-dimethyl-N-ethylethylenediamine, N-n-propylethylenediamine, N,N'-n-propylethylenediamine, N-isopropylethylenediamine, N,N'-isopropylethylenediamine, N-n-butylethylenediamine, N,N'-n-butylethylenediamine, etc. N-Isobutylethylenediamine, N,N'-Isobutylethylenediamine, N-tert-butylethylenediamine, N,N'-tert-butylethylenediamine, N,N,N',N'-Tetramethyl-1,3-diaminopropane, N,N,N'-Trimethyl-1,3-diaminopropane, N,N'-Dimethyl-1,3-diaminopropane, N-Methyl-1,3-diaminopropane, N,N,N',N'-Tetramethyl-1,3-diamino-1-methylpropane, N,N,N',N'-Tetramethyl-1,3-diamino-2-methylpropane, N,N,N',N'-Tetramethyl-1,4-diaminobutane, N,N,N',N'-Tetramethyl-1,5-diaminopentane, etc. In this embodiment, the preferred diamine compound is a diamine compound in which the alkylene group connected to two nitrogen atoms has two or three carbon atoms. The amount of these diamine compounds is not particularly limited, but is preferably in the range of 0.01 to 10 moles relative to 100 moles of phenol compound added in the polymerization reaction.

[0163] In this embodiment, the components of the polymerization catalyst may include primary amines and secondary monoamines. Examples of secondary monoamines include, but are not limited to, dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-butylamine, diisobutylamine, di-tert-butylamine, dipentylamine, dihexylamine, dioctylamine, didecylamine, dibenzylamine, methylethylamine, methylpropylamine, methylbutylamine, cyclohexylamine, N-phenylmethanolamine, N-phenylethanolamine, N-phenylpropanolamine, N-(m-methylphenyl)ethanolamine, N-(p-methylphenyl)ethanolamine, N-(2',6'-dimethylphenyl)ethanolamine, N-(p-chlorophenyl)ethanolamine, N-ethylaniline, N-butylaniline, N-methyl-2-methylaniline, N-methyl-2,6-dimethylaniline, and diphenylamine.

[0164] As a component of the polymerization catalyst in this embodiment, a tertiary monoamine compound may also be included. Tertiary monoamine compounds refer to aliphatic tertiary amines, including alicyclic tertiary amines. Examples include trimethylamine, triethylamine, tripropylamine, tributylamine, triisobutylamine, dimethylethylamine, dimethylpropylamine, allyl diethylamine, dimethyl n-butylamine, diethylisopropylamine, and N-methylcyclohexylamine. These tertiary monoamines can be used alone or in combination of two or more. Their amounts are not particularly limited, but are preferably in the range of 15 moles or less relative to 100 moles of the phenol compound added in the polymerization reaction.

[0165] In this embodiment, there are no limitations on the addition of existing surfactants known to enhance polymerization activity. Examples of such surfactants include trioctylmethylammonium chloride, known by trade names Aliquat336 and Capriquat. The amount used is preferably no more than 0.1% by mass relative to 100% of the total polymerization reaction mixture.

[0166] In addition to pure oxygen, the oxygen-containing gas used in the polymerization of this embodiment can also be a gas formed by mixing oxygen and inert gases such as nitrogen in any proportion, air, or a gas formed by mixing air and inert gases such as nitrogen in any proportion. Atmospheric pressure is sufficient within the system during the polymerization reaction, but depressurization or pressurization can be used as needed.

[0167] There is no particular limitation on the polymerization temperature, but if the temperature is too low, the reaction will be difficult to proceed. In addition, if the temperature is too high, the reaction selectivity may be reduced and a gel may be formed. Therefore, the temperature range is 0 to 60°C, preferably 10 to 40°C.

[0168] In the manufacturing process of polyphenylene ether, polymerization can also be carried out in undesirable solvents such as alcohols.

[0169] (Copper extraction and by-product removal process)

[0170] In this embodiment, there are no particular limitations on the post-treatment method after the polymerization reaction. Typically, acids such as hydrochloric acid or acetic acid, or ethylenediaminetetraacetic acid (EDTA) and its salts, hypozinotriacetic acid and its salts, are added to the reaction solution to deactivate the catalyst. Furthermore, existing known methods can be used to remove the byproducts of the diphenols produced by the polymerization of polyphenylene ether. If the metal ions acting as the catalyst are substantially deactivated as described above, decolorization can be achieved simply by heating the mixture. Alternatively, a method can be used that involves adding a necessary amount of a known reducing agent. Examples of known reducing agents include hydroquinone and sodium dithionite.

[0171] (Liquid-liquid separation process)

[0172] In the manufacturing process of polyphenylene ether, to extract the compounds resulting from the deactivation of the copper catalyst, water can be added to perform liquid-liquid separation, separating the liquid phase into an organic phase and an aqueous phase. The aqueous phase is then removed, thereby removing the copper catalyst from the organic phase. This liquid-liquid separation process is not particularly limited, and methods such as static separation or separation using a centrifuge can be cited. To facilitate the liquid-liquid separation, known surfactants can be used.

[0173] (Concentration-Drying Process)

[0174] Next, in the method for manufacturing polyphenylene ether according to this embodiment, concentration and drying can be carried out by evaporating the solvent in the organic phase containing the above-mentioned polyphenylene ether after liquid-liquid separation.

[0175] There are no particular limitations on the method for evaporating the solvent contained in the organic phase. Examples include: transferring the organic phase to a high-temperature concentration tank and concentrating it by distilling off the solvent; concentrating it by distilling off toluene using equipment such as a rotary evaporator; and so on.

[0176] The drying temperature in the drying process is preferably at least 60°C or higher, more preferably 80°C or higher, even more preferably 120°C or higher, and most preferably 140°C or higher. Drying polyphenylene ether at a temperature of 60°C or higher can effectively reduce the content of high-boiling-point volatile components in the polyphenylene ether powder.

[0177] To efficiently obtain polyphenylene ether, methods such as increasing the drying temperature, increasing the vacuum level in the drying atmosphere, and stirring during drying are effective. In particular, from a manufacturing efficiency perspective, increasing the drying temperature is preferred. The drying process preferably uses a dryer with a mixing function. Examples of dryers with agitation or rotary mixing functions include stirred dryers. This increases throughput and maintains high productivity.

[0178] The polyphenylene ether of this embodiment can also be manufactured by a redistribution reaction of a polyphenylene ether derived from phenol of formula (1) above with a phenol compound of formula (2) above in the presence of an oxidant. Redistribution reactions are well known in the art, for example described in U.S. Patent No. 3,496,236 to Cooper et al. and U.S. Patent No. 5,880,221 to Liska et al.

[0179] (Modification reaction process)

[0180] There is no limitation on the method of introducing functional groups into the hydroxyl groups of unmodified polyphenylene ether. For example, it can be obtained by reacting the hydroxyl groups of unmodified polyphenylene ether with a carboxylic acid (hereinafter referred to as carboxylic acid) having a carbon-carbon double bond to form an ester bond. Various known methods can be used to form the ester bond. Examples include: a. the reaction of a carboxyl halide with the terminal hydroxyl group of the polymer; b. the formation of an ester bond by reacting with a carboxylic anhydride; c. the direct reaction with a carboxylic acid; d. methods based on transesterification; and so on. The reaction of a with a carboxyl halide is one of the most common methods. Chlorides and bromides are commonly used as carboxyl halides, but other halogens can also be used. The reaction can be either a direct reaction with a hydroxyl group or a reaction with an alkali metal salt of a hydroxyl group. In the direct reaction of a carboxyl halide with a hydroxyl group, acids such as hydrogen halides are produced; therefore, to capture the acid, a weak base such as an amine can coexist. In the reactions b with carboxylic anhydrides and c with carboxylic acids, compounds such as carbodiimides and dimethylaminopyridines can be coexisted to activate the reaction sites and promote the reaction. In the case of the transesterification reaction d, it is preferable to remove the generated alcohol as needed. Alternatively, known metal catalysts can be coexisted to promote the reaction. After the reaction, to remove byproducts such as amine salts, washing with water, acidic or alkaline aqueous solutions is possible. The polymer solution can also be added dropwise to a poor solvent such as an alcohol, and the target product can be recovered by reprecipitation. Alternatively, after washing the polymer solution, the solvent can be removed by distillation under reduced pressure to recover the polymer.

[0181] The method for manufacturing modified polyphenylene ether in this embodiment is not limited to the method for manufacturing multifunctional modified polyphenylene ether described in this embodiment. The order and number of steps of the oxidation polymerization process, copper extraction and by-product removal process, liquid-liquid separation process, and concentration-drying process can be appropriately adjusted.

[0182] (polyphenylene ether solution)

[0183] The polyphenylene ether solution of this embodiment contains at least the polyphenylene ether and ketone solvent described in this embodiment, and may further contain other components. Additionally, solvents other than ketone solvents may also be included as solvents.

[0184] Examples of ketone solvents include acetone, methyl ethyl ketone, methyl propyl ketone, methyl isobutyl ketone, diisobutyl ketone, and cyclohexanone.

[0185] The ratio of the total mass of the above-mentioned polyphenylene ether and the above-mentioned ketone solvent to 100% by mass of the above-mentioned polyphenylene ether solution is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, and particularly preferably 100% by mass.

[0186] The mass ratio of the polyphenylene ether to the polyphenylene ether solution (100% by mass) is preferably 1 to 40% by mass. Furthermore, the mass ratio of the ketone solvent to the polyphenylene ether solution (100% by mass) is preferably 60 to 99% by mass.

[0187] The above-mentioned polyphenylene ether solution can be manufactured, for example, by mixing the above-mentioned polyphenylene ether, the above-mentioned ketone solvent, and optional other components and other solvents.

[0188] <Thermosetting Compositions>

[0189] The polyphenylene ether of this embodiment can be used as a raw material for thermosetting compositions. There are no particular limitations as long as the thermosetting composition contains polyphenylene ether; it is preferable to further contain a crosslinking agent and an organic peroxide, and it may further contain thermoplastic resins, flame retardants, other additives, silica fillers, solvents, etc., as desired. The constituent elements of the thermosetting composition of this embodiment will be described below.

[0190] (polyphenylene oxide)

[0191] As described above, the polyphenylene ether of this embodiment can be used as a standalone resin in a thermosetting composition, or in combination with polyphenylene ethers having other structures, or in combination with various known additives.

[0192] When used in combination with other components, the content of polyphenylene ether in the thermosetting composition is preferably 0.5 to 95% by mass, more preferably 20 to 93% by mass, and even more preferably 40 to 90% by mass.

[0193] (Cross-linking agent)

[0194] In the thermosetting composition of this embodiment, any crosslinking agent capable of initiating or promoting a crosslinking reaction can be used.

[0195] The crosslinking agent preferably has a number average molecular weight of 4,000 or less. When the number average molecular weight of the crosslinking agent is 4,000 or less, it can suppress the increase in viscosity of the thermosetting composition and obtain good resin flowability during heat molding.

[0196] It should be noted that the number-average molecular weight can be the value determined using conventional molecular weight determination methods, such as the value determined using GPC.

[0197] From the perspective of cross-linking reaction, the cross-linking agent preferably has an average of more than two carbon-carbon unsaturated double bonds per molecule. The cross-linking agent can be composed of one compound or two or more compounds.

[0198] It should be noted that, when referring to "carbon-carbon unsaturated double bonds" in this specification, in the case of a polymer or oligomer as the crosslinking agent, it refers to double bonds located at the ends of branches originating from the main chain. An example of a carbon-carbon unsaturated double bond is the 1,2-vinyl bond in polybutadiene.

[0199] When the number average molecular weight of the crosslinking agent is less than 600, the number (average) of carbon-carbon unsaturated double bonds per molecule of the crosslinking agent is preferably 2 to 4. When the number average molecular weight of the crosslinking agent is 600 or more and less than 1,500, the number (average) of carbon-carbon unsaturated double bonds per molecule of the crosslinking agent is preferably 4 to 26. When the number average molecular weight of the crosslinking agent is 1,500 or more and less than 4,000, the number (average) of carbon-carbon unsaturated double bonds per molecule of the crosslinking agent is preferably 26 to 60. When the number average molecular weight of the crosslinking agent is within the above range, by making the number of carbon-carbon unsaturated double bonds above the above-mentioned specific value, the reactivity of the crosslinking agent in the thermosetting composition of this embodiment is further improved, the crosslinking density of the cured thermosetting composition is further improved, and as a result, superior heat resistance can be imparted. On the other hand, when the number average molecular weight of the crosslinking agent is within the above range, by making the number of carbon-carbon unsaturated double bonds below the above-mentioned specific value, superior resin flowability can be imparted during thermoforming.

[0200] Examples of crosslinking agents include: triallenyl isocyanurate compounds such as triallenyl isocyanurate (TAIC), triallenyl cyanurate compounds such as triallenyl cyanurate (TAC), polyfunctional methacrylate compounds having two or more methacryloyl groups in the molecule, polyfunctional acrylate compounds having two or more acryloyl groups in the molecule, polyfunctional vinyl compounds having two or more vinyl groups in the molecule such as polybutadiene, vinylbenzyl compounds such as divinylbenzene having a vinyl benzyl group in the molecule, and polyfunctional maleimide compounds having two or more maleimide groups in the molecule such as 4,4'-bismaleimide diphenylmethane. These crosslinking agents can be used alone or in combination of two or more. Preferably, the crosslinking agent comprises at least one compound selected from the group consisting of triallenyl cyanurate, triallenyl isocyanurate, and polybutadiene. By including at least one of the compounds described above in the crosslinking agent, the thermosetting composition tends to have better compatibility and coatability with the crosslinking agent and better substrate properties when mounted on an electronic circuit board.

[0201] From the perspective of improving the compatibility of the crosslinking agent with the modified polyphenylene ether, the coatability of the thermosetting composition, and the properties of the mounted electronic circuit board, the mass ratio of polyphenylene ether to crosslinking agent (polyphenylene ether: crosslinking agent) is preferably 25:75 to 95:5, more preferably 32:68 to 85:15.

[0202] (Organic peroxides)

[0203] In this embodiment, any organic peroxide that has the ability to promote the polymerization reaction of a thermosetting composition containing polyphenylene ether and a crosslinking agent can be used. Examples of organic peroxides include benzoyl peroxide, cumene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)-3-hexyne, di-tert-butyl peroxide, tert-butylcumyl peroxide, di(2-tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, dicumyl peroxide, di-tert-butylperoxyisophthalate, tert-butyl peroxybenzoate, 2,2-bis(tert-butylperoxy)butane, 2,2-bis(tert-butylperoxy)octane, 2,5-dimethyl-2,5-di(benzoyl peroxide)hexane, di(trimethylsilyl)peroxide, trimethylsilyltriphenylsilyl peroxide, and other peroxides. It should be noted that free radical initiators such as 2,3-dimethyl-2,3-diphenylbutane can also be used as reaction initiators for thermosetting compositions. Among them, 2,5-dimethyl-2,5-di(tert-butylperoxy)-3-hexyne, di(2-tert-butylperoxyisopropyl)benzene, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane are preferred from the perspective of obtaining a cured product with excellent heat resistance and mechanical properties and thus providing a low dielectric loss tangent (and preferably a low dielectric constant).

[0204] The 1-minute half-life temperature of the organic peroxide is preferably 155–185°C, more preferably 160–180°C, and even more preferably 165–175°C. By keeping the 1-minute half-life temperature of the organic peroxide in the range of 155–185°C, there is a tendency for the organic peroxide to have better compatibility with modified PPE, better coatability of the thermosetting composition, and better properties of the mounted electronic circuit board.

[0205] It should be noted that, in this specification, the 1-minute half-life temperature is the temperature at which the organic peroxide decomposes and its reactive oxygen species reach half their original value within one minute. The 1-minute half-life temperature is a value determined by dissolving the organic peroxide in a solvent inert to free radicals, such as benzene, to a concentration of 0.05–0.1 mol / L, and then thermally decomposing the organic peroxide solution under a nitrogen atmosphere.

[0206] Examples of organic peroxides with a 1-minute half-life temperature in the range of 155–185°C include tert-hexyl isopropyl peroxide (155.0°C), tert-butyl peroxide-3,5,5-trimethylhexanoate (166.0°C), tert-butyl perlaurate (159.4°C), tert-butyl isopropyl peroxide (158.8°C), tert-butyl 2-ethylhexyl peroxide (161.4°C), tert-hexyl peroxide (160.3°C), and 2,5-dimethyl-2,5-di(benzoyl peroxide)hexane (158.2°C). The following are examples of peroxides: tert-butyl peroxyacetate (159.9℃), 2,2-di(tert-butylperoxy)butane (159.9℃), tert-butyl peroxybenzoate (166.8℃), n-butyl 4,4-di(tert-butylperoxy)valerate (172.5℃), di(2-tert-butylperoxyisopropyl)benzene (175.4℃), dicumyl peroxide (175.2℃), ditert-hexyl peroxide (176.7℃), 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (179.8℃), and tert-butylcumyl peroxide (173.3℃).

[0207] Regarding the content of organic peroxide, based on 100 parts by mass of polyphenylene ether and crosslinking agent, from the perspective of improving the compatibility of organic peroxide with modified PPE and the coatability of thermosetting composition, it is preferably 0.05 parts by mass or more, more preferably 0.5 parts by mass or more, further preferably 1 part by mass or more, and even more preferably 1.5 parts by mass or more. From the perspective of improving the substrate characteristics when the thermosetting composition is mounted on an electronic circuit board, it is preferably 5 parts by mass or less, more preferably 4.5 parts by mass or less.

[0208] (Thermoplastic resin)

[0209] The thermoplastic resin is preferably at least one selected from the group consisting of block copolymers of vinyl aromatic compounds and olefinic compounds and their hydrogenates (hydrogenated block copolymers obtained by hydrogenating block copolymers of vinyl aromatic compounds and olefinic compounds), and homopolymers of vinyl aromatic compounds.

[0210] Furthermore, from the perspective of improving compatibility with polyphenylene ether, resin flowability, coatability of thermosetting compositions, and heat resistance during curing, the weight-average molecular weight of the thermoplastic resin is preferably greater than 50,000 and less than 780,000, more preferably 60,000 to 750,000, and even more preferably 70,000 to 700,000.

[0211] When a thermosetting composition contains polyphenylene ether, a crosslinking agent, an organic peroxide, and a thermoplastic resin having the types and weight-average molecular weights described above, it tends to have good compatibility with modified PPE and other containing components, as well as good coatability to substrates, and thus, when assembled into an electronic circuit board, the substrate properties are also excellent.

[0212] It should be noted that the weight-average molecular weight was determined by the method described in the examples below.

[0213] The lower limit of the content of vinyl aromatic compound-derived units in the above-mentioned block copolymers or their hydrogenated derivatives is preferably 20% by mass or more, more preferably 22% by mass or more, 24% by mass or more, 26% by mass or more, 28% by mass or more, 30% by mass or more, or 32% by mass or more. Furthermore, the upper limit is preferably 70% by mass or less, more preferably 69% by mass or less, 68% by mass or less, or 67% by mass or less. By setting the content of vinyl aromatic compound-derived units in the above-mentioned block copolymers or their hydrogenated derivatives to 20 to 70% by mass, there is a tendency to further improve the compatibility with modified polyphenylene ether and / or further improve the adhesion strength with the metal foil.

[0214] As a vinyl aromatic compound, it is sufficient to have an aromatic ring and a vinyl group within the molecule; for example, styrene can be cited.

[0215] As a chain olefin compound, any olefin that has a straight-chain or branched structure within the molecule can be used, such as ethylene, propylene, butene, isobutene, butadiene, and isoprene.

[0216] As a thermoplastic resin, from the perspective of superior compatibility with polyphenylene ether, it is preferably selected from at least one of the group consisting of styrene-butadiene block copolymer, styrene-ethylene-butadiene block copolymer, styrene-ethylene-butene block copolymer, styrene-butadiene-butene block copolymer, styrene-isoprene block copolymer, styrene-ethylene-propylene block copolymer, styrene-isobutylene block copolymer, hydride of styrene-butadiene block copolymer, hydride of styrene-ethylene-butadiene block copolymer, hydride of styrene-butadiene-butene block copolymer, hydride of styrene-isoprene block copolymer, and homopolymer of styrene (polystyrene), more preferably one or more selected from the group consisting of styrene-butadiene block copolymer, hydride of styrene-butadiene block copolymer, and polystyrene.

[0217] There is no particular limitation on the hydrogenation rate in the above-mentioned hydrides, and some carbon-carbon unsaturated double bonds from olefin compounds may remain.

[0218] Based on 100 parts by weight of the total polyphenylene ether and crosslinking agent, the content of thermoplastic resin is preferably 2 to 20 parts by weight, more preferably 3 to 19 parts by weight, further preferably 4 to 18 parts by weight, and particularly preferably 5 to 17 parts by weight. By keeping this content within the above-mentioned range, the thermosetting composition of this embodiment tends to have better compatibility and coatability between the thermoplastic resin and the modified polyphenylene ether, and better substrate properties when mounted on an electronic circuit board.

[0219] It should be noted that the thermosetting composition of this embodiment may also contain thermoplastic resins other than those of the types and weight-average molecular weights described above.

[0220] (Flame retardant)

[0221] The thermosetting composition of this embodiment preferably includes a flame retardant. As a flame retardant, there are no particular limitations as long as it is incompatible with other components in the thermosetting composition after curing, from the perspective of improving heat resistance. Preferably, the flame retardant is incompatible with the polyphenylene ether and / or crosslinking agent in the thermosetting composition after curing.

[0222] Examples of flame retardants include: inorganic flame retardants such as antimony trioxide, aluminum hydroxide, magnesium hydroxide, and zinc borate; aromatic bromine compounds such as hexabromobenzene, decabromodiphenyl ethane, 4,4-dibromobiphenyl, and ethylene bis(tetrabromophthalimide); and phosphorus-based flame retardants such as resorcinol bis(diphenyl phosphate) and resorcinol bis(di(xylyl) phosphate). These flame retardants can be used alone or in combination of two or more. Among these, decabromodiphenyl ethane is preferred due to its superior compatibility with modified PPE, the coatability of the thermosetting composition, and the properties of the mounted electronic circuit board.

[0223] The content of the flame retardant is not particularly limited, but from the perspective of maintaining the flame retardancy of the V-0 rating of UL Standard 94, it is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, relative to a total of 100 parts by mass of polyphenylene ether and crosslinking agent. In addition, from the perspective of maintaining a low dielectric loss tangent of the obtained cured product (and preferably also maintaining a low dielectric constant), the content of the flame retardant is preferably 50 parts by mass or less, more preferably 45 parts by mass or less, and even more preferably 40 parts by mass or less.

[0224] (Silica filler)

[0225] The thermosetting composition of this embodiment may contain silica filler. Examples of silica fillers include natural silica, molten silica, synthetic silica, amorphous silica, AEROSIL, and hollow silica.

[0226] The content of silica filler can be 10 to 100 parts by weight relative to 100 parts by weight of polyphenylene ether and crosslinking agent. Furthermore, the silica filler can be a substance whose surface has been treated with a silane coupling agent or similar material.

[0227] In addition to flame retardants and silica fillers, the thermosetting composition of this embodiment may further include heat stabilizers, antioxidants, UV absorbers, surfactants, lubricants and other additives, solvents and the like.

[0228] When the thermosetting composition of this embodiment contains a solvent, it can be in the form of a varnish formed by dissolving or dispersing the solid components in the thermosetting composition in the solvent. In addition, a resin film can be formed from the thermosetting composition of this embodiment.

[0229] (solvent)

[0230] From a solubility perspective, aromatic compounds such as toluene and xylene, methyl ethyl ketone (MEK), cyclopentanone, cyclohexanone, and chloroform are preferred solvents. These solvents can be used individually or in combination of two or more.

[0231] <Prepreg>

[0232] The prepreg of this embodiment comprises a substrate and the thermosetting composition of this embodiment described above, and preferably a composite comprising the substrate and the thermosetting composition of this embodiment impregnated or coated onto the substrate. The prepreg is obtained, for example, by impregnating a substrate such as glass cloth in a varnish of the thermosetting composition and then drying and removing the solvent components using a hot air dryer or the like.

[0233] Examples of suitable substrates include: various glass cloths such as untwisted roving, cloth, chopped strand mat, and surface mat; asbestos cloth, metal fiber cloth, and other synthetic or natural inorganic fiber cloths; textiles or nonwovens made from liquid crystal fibers such as fully aromatic polyamide fibers, fully aromatic polyester fibers, and polybenzoxazole fibers; natural fiber cloths such as cotton cloth, linen cloth, and felt; natural cellulose substrates such as carbon fiber cloth, kraft paper, cotton paper, and cloths made from paper-glass blended yarns; polytetrafluoroethylene porous membranes; and so on. Glass cloth is preferred. These substrates can be used individually or in combination of two or more.

[0234] The proportion of the solid component (components other than the solvent of the thermosetting composition) of the prepreg in this embodiment is preferably 30 to 80% by mass, more preferably 40 to 70% by mass. When the above proportion is 30% by mass or more, the prepreg tends to have superior insulation reliability when used for applications such as electronic substrates. When the above proportion is 80% by mass or less, the prepreg tends to have superior mechanical properties such as flexural modulus in applications such as electronic substrates.

[0235] <Laminated body>

[0236] The laminate of this embodiment comprises a cured prepreg of this embodiment and a metal foil, and is preferably a metal-clad laminate obtained by laminating and curing the thermosetting composition of this embodiment or the prepreg of this embodiment with a metal foil. The metal-clad laminate preferably has a form in which the cured prepreg (hereinafter also referred to as "cured composite") is laminated and bonded with a metal foil, and can be suitably used as a material for electronic substrates.

[0237] Examples of metal foils include aluminum foil and copper foil, with copper foil being preferred due to its low resistance.

[0238] The cured composite combined with metal foil can be one sheet or two or more sheets. Depending on the application, metal foil can be stacked on one or both sides of the composite and processed into a laminate.

[0239] As a method for manufacturing metal-clad laminates, for example, the following method can be used: forming a composite material (such as the prepreg mentioned above) consisting of a thermosetting composition and a substrate, stacking it with a metal foil, and then curing the thermosetting composition to obtain a laminate formed by laminating the cured laminate with the metal foil.

[0240] One particularly preferred application of the aforementioned metal-clad laminate is a printed wiring board. In the printed wiring board, it is preferable to remove at least a portion of the metal foil from the metal-clad laminate.

[0241] Printed wiring board

[0242] A printed wiring board can be fabricated by removing at least a portion of the metal foil from the aforementioned metal-clad laminate. The aforementioned printed wiring board can typically be formed by pressurizing and heating the prepreg used in this embodiment. As the substrate, the same material as the substrate described above for the prepreg can be cited.

[0243] The printed wiring board described above, by incorporating the thermosetting composition of this embodiment, has excellent heat resistance and electrical properties (low dielectric loss tangent and / or low dielectric constant), thereby suppressing changes in electrical properties accompanied by environmental variations, and thus having excellent insulation reliability and mechanical properties.

[0244] Example

[0245] The following describes this embodiment in more detail based on the embodiments, but this embodiment is not limited to the following embodiments.

[0246] First, the measurement methods and evaluation criteria for each property are described below.

[0247] (1) The molar ratio of repeating units of phenol derived from formula (1) or formula (2) contained in unmodified polyphenylene ether relative to the total number of repeating units of phenol derived from formula (1) and repeating units of phenol derived from formula (2).

[0248] The unmodified polyphenylene ether obtained in the examples and comparative examples was dissolved in deuterated chloroform, and tetramethylsilane was used as an internal standard for the reaction. 1 ¹H-NMR determination (JEOL 500MHz). For the determination, polyphenylene ether was pre-treated at 140°C and 1 mmHg for 8 hours to remove volatile components such as toluene and water, and was then measured as unmodified polyphenylene ether in a dry state. The signals of the phenol units derived from formulas (1) and (2) were identified, and their respective proportions were calculated.

[0249] For example, in the unmodified polyphenylene ethers obtained in the Examples and Comparative Examples, the signal from the repeating unit of phenol derived from formula (1), namely the structure derived from 2,6-dimethylphenol (2,6-dimethylphenylene unit), and the signal from the repeating unit of phenol derived from formula (2), namely the structure derived from 2-tert-butyl-5-methylphenol (2-tert-butyl-5-methylphenylene unit), were analyzed as follows. The peaks derived from the repeating units of each phenol appeared in the following regions.

[0250] Peaks originating from the hydrogen atom of the methyl group in the 2,6-dimethylphenylene unit and the 2-tert-butyl-5-methylphenylene unit (6H and 3H, respectively): 1.60–2.50 ppm (excluding the peak originating from the hydrogen atom of the methyl group in toluene).

[0251] The peak (9H) of the tert-butyl group of the 2-tert-butyl-5-methylphenylene unit originating from hydrogen atoms: 1.00–1.52 ppm (excluding the peak originating from hydrogen atoms from water).

[0252] By investigating the integral value of the above signal, the integral value of each proton of the peak from the hydrogen atom of the methyl group of the 2,6-dimethylphenylene unit can be obtained by the following mathematical formula (1).

[0253] E={C-3×(D / 9)} / 6···Mathematical expression (1)

[0254] Integral values ​​of the peaks originating from the methyl groups of the 2,6-dimethylphenylene unit and the 2-tert-butyl-5-methylphenylene unit.

[0255] D: Integral value of the peak originating from the tert-butyl group of the 2-tert-butyl-5-methylphenylene unit.

[0256] E: Integral value per proton of the peak originating from the methyl group of the 2,6-dimethylphenylene unit.

[0257] The proportion (mol%) of repeating units of phenol derived from formula (1) or formula (2) can be further calculated using the following mathematical formulas (2) and (3).

[0258] The proportion (mol%) of repeating units of phenol derived from formula (1) = E / {(D / 9)+E}×100··· Mathematical formula (2)

[0259] The proportion (mol%) of repeating units of phenol derived from formula (2) = (D / 9) / {(D / 9)+E}×100··· Mathematical formula (3)

[0260] (2) The molar ratio of repeating units derived from impurity A contained in unmodified polyphenylene ether relative to the total repeating units of phenol derived from formula (1), repeating units of phenol derived from formula (2), and repeating units derived from impurity A.

[0261] The unmodified polyphenylene ether obtained in the examples and comparative examples was dissolved in deuterated chloroform, and tetramethylsilane was used as an internal standard for the reaction. 1 ¹H-NMR determination (JEOL 500MHz). For the determination, the polyphenylene ether was pre-treated at 140°C and 1 mmHg for 8 hours to remove volatile components such as toluene and water, and was then measured as unmodified polyphenylene ether in a dry state. The signals of the units derived from formulas (1), (2), and impurity A (phenol) were identified, and their respective proportions were calculated.

[0262] For example, in the unmodified polyphenylene ethers obtained in the examples and comparative examples, the signals from the repeating unit of phenol derived from formula (1), namely the structure derived from 2,6-dimethylphenol (2,6-dimethylphenylene unit), the repeating unit of phenol derived from formula (2), namely the structure derived from 2-tert-butyl-5-methylphenol (2-tert-butyl-5-methylphenylene unit), and the repeating unit derived from impurity A, namely R in formula (11), are compared. 11 =Methyl, R 12 The signal attribution method for the repeating unit with z=0 (=hydrogen atom) is analyzed as follows. The peaks derived from the repeating units of each phenol appear in the following regions.

[0263] Derived from the 2,6-dimethylphenylene unit, the 2-tert-butyl-5-methylphenylene unit, and R in formula (11) 11 =Methyl, R 12 = Hydrogen atom, z=0 repeating unit signal, methyl hydrogen atom source peak (6H, 3H, 12H respectively): 1.60~2.50ppm (excluding the toluene methyl hydrogen atom source peak).

[0264] The peak (9H) of the tert-butyl group of the 2-tert-butyl-5-methylphenylene unit originating from hydrogen atoms: 1.00–1.52 ppm (excluding the peak originating from hydrogen atoms from water).

[0265] R in equation (11) 11 =Methyl, R 12 =Hydrogen atom, the peak (4H) of the repeating unit methyl group with z=0: 7.35 ppm

[0266] By investigating the integral value of the above signal, the integral value of each proton of the peak from the hydrogen atom of the methyl group of the 2,6-dimethylphenylene unit can be obtained by the following mathematical formula (4).

[0267] E={C-3×(D / 9)-12×(F / 4)} / 6···Mathematical expression (4)

[0268] Integral values ​​of the peaks originating from the methyl groups of the 2,6-dimethylphenylene unit and the 2-tert-butyl-5-methylphenylene unit.

[0269] D: Integral value of the peak originating from the tert-butyl group of the 2-tert-butyl-5-methylphenylene unit.

[0270] F: R in equation (11) 11 =Methyl, R 12 =Integral value of the peak originating from hydrogen atoms in the repeating unit of the benzene ring with hydrogen atoms at z=0

[0271] E: Integral value per proton of the peak originating from the methyl group of the 2,6-dimethylphenylene unit.

[0272] Furthermore, R in equation (11) can be calculated using the following mathematical formula (5). 11 =Methyl, R 12 = The proportion of hydrogen atoms and z=0 structures (mol%).

[0273] R in equation (11) 11 =Methyl, R 12 = The proportion of hydrogen atoms and repeating units with z=0 (mol%) = (F / 4) / {(D / 9)+E+(F / 4)}×100··· Mathematical formula (5)

[0274] (3) The molar ratio of the repeating unit of monophenol containing at least one unsaturated hydrocarbon group on the carbon atom adjacent to the carbon atom bonded to the hydroxyl group of phenol contained in the unmodified polyphenylene ether relative to the repeating unit of phenol derived from formula (1) and the repeating unit of the above monophenol containing at least one unsaturated hydrocarbon group on the carbon atom adjacent to the carbon atom bonded to the hydroxyl group of phenol.

[0275] The unmodified polyphenylene ether obtained in the examples and comparative examples was dissolved in deuterated chloroform, and tetramethylsilane was used as an internal standard for the reaction. 1 ¹H-NMR determination (JEOL 500MHz). For the determination, polyphenylene ether was pre-treated at 140°C and 1 mmHg for 8 hours to remove volatile components such as toluene and water, and was then measured as unmodified polyphenylene ether in a dry state. The signals of repeating units derived from phenol of formula (1), repeating units derived from phenol of formula (2), and repeating units of monophenols having at least one unsaturated hydrocarbon group on the carbon atom adjacent to the carbon atom bonded to the hydroxyl group of phenol were identified, and their respective proportions were calculated.

[0276] For example, in the unmodified polyphenylene ethers obtained in the Examples and Comparative Examples, signals from the repeating unit of phenol derived from formula (1), namely 2,6-dimethylphenol (2,6-dimethylphenylene unit), the repeating unit of phenol derived from formula (2), namely 2-tert-butyl-5-methylphenol (2-tert-butyl-5-methylphenylene unit), and the repeating unit of monophenol derived from 2-allylphenol (2-allylphenylene unit) having at least one unsaturated hydrocarbon group on the carbon atom adjacent to the carbon atom bonded to the hydroxyl group of phenol appeared in the following regions.

[0277] Peaks originating from the hydrogen atom of the methyl group in the 2,6-dimethylphenylene unit and the 2-tert-butyl-5-methylphenylene unit (6H and 3H, respectively): 1.60–2.50 ppm (excluding the peak originating from the hydrogen atom of the methyl group in toluene).

[0278] The peak (9H) of the tert-butyl group of the 2-tert-butyl-5-methylphenylene unit originating from hydrogen atoms: 1.00–1.52 ppm (excluding the peak originating from hydrogen atoms from water).

[0279] Peak (2H) originating from the methylene atom of the 2-allylphenylene unit: 3.40 ppm

[0280] By investigating the integral value of the above signal, the integral value of each proton of the peak originating from the hydrogen atom of the methyl group of the 2,6-dimethylphenylene unit can be obtained by the following mathematical formula (6).

[0281] E={C-3×(D / 9)} / 6···Mathematical expression (6)

[0282] Integral values ​​of the peaks originating from the methyl groups of the 2,6-dimethylphenylene unit and the 2-tert-butyl-5-methylphenylene unit.

[0283] D: Integral value of the peak originating from the tert-butyl group of the 2-tert-butyl-5-methylphenylene unit.

[0284] E: Integral value per proton of the peak originating from the methyl group of the 2,6-dimethylphenylene unit.

[0285] The proportion (mol%) of 2-allylphenylene units can be further calculated using the following mathematical formula (7).

[0286] The proportion of 2-allylphenylene units (mol%) = (G / 2) / {E+(G / 2)}×100··· Mathematical formula (7)

[0287] The integral value per proton of the peak originating from the methylene group of the 2-allylphenylene unit.

[0288] (4) The molar ratio of repeating units of phenol derived from formula (1) or formula (2) contained in the modified polyphenylene ether relative to the total number of repeating units of phenol derived from formula (1) and repeating units of phenol derived from formula (2).

[0289] The following determinations were performed on the modified polyphenylene ether.

[0290] The modified polyphenylene ethers obtained in the examples and comparative examples were dissolved in the assay solvent (deuterated chloroform with 1 drop of heavy water added to remove the hydroxyl groups), and tetramethylsilane was used as an internal standard for analysis. 1 H-NMR determination (JEOL 500MHz). During the determination, the polyphenylene ether was pre-treated at 80°C and 1 mmHg for 8 hours to remove volatile components such as toluene and water, and the modified polyphenylene ether was measured as a dried product. The signals of the phenol units derived from formulas (1) and (2) were identified, and their respective proportions were calculated.

[0291] For example, in the modified polyphenylene ethers obtained in the examples and comparative examples, the signals derived from the repeating unit of phenol derived from formula (1), namely the structure derived from 2,6-dimethylphenol (2,6-dimethylphenylene unit), the repeating unit of phenol derived from formula (2), namely the structure derived from 2-tert-butyl-5-methylphenol (2-tert-butyl-5-methylphenylene unit), and the signals derived from partial structures selected from the group consisting of formulas (4), (5), (6), or (7), namely the signals derived from the structure derived from methacryloyl, were analyzed as follows. The peaks derived from the repeating units of each phenol appeared in the following regions.

[0292] Peaks originating from hydrogen atoms of the methyl group in 2,6-dimethylphenylene, 2-tert-butyl-5-methylphenylene, and methacryloyl (6H, 3H, 3H, respectively): 1.60–2.50 ppm (excluding peaks originating from hydrogen atoms of the methyl group in toluene).

[0293] The peak (9H) of the tert-butyl group of the 2-tert-butyl-5-methylphenylene unit originating from hydrogen atoms: 1.00–1.52 ppm (excluding the peak originating from hydrogen atoms from water).

[0294] Peak (1H) originating from one hydrogen atom of the methylene group of methacryloyl group: 4.4–5.8 ppm

[0295] By investigating the integral value of the above signal, the integral value of each proton of the peak from the hydrogen atom of the methyl group of the 2,6-dimethylphenylene unit can be obtained by the following mathematical formula (8).

[0296] E={C-3×(D / 9)-3×(H / 1)} / 6···Mathematical expression (8)

[0297] Integral values ​​of the peaks originating from the methyl groups of the 2,6-dimethylphenylene unit and the 2-tert-butyl-5-methylphenylene unit.

[0298] D: Integral value of the peak originating from the tert-butyl group of the 2-tert-butyl-5-methylphenylene unit.

[0299] E: Integral value per proton of the peak originating from the methyl group of the 2,6-dimethylphenylene unit.

[0300] H: The integral value of the peak originating from one hydrogen atom of the methylene group of methacryloyl group.

[0301] The proportion (mol%) of repeating units of phenol derived from formula (1) or formula (2) can be further calculated using the following mathematical formulas (9) and (10).

[0302] The proportion (mol%) of repeating units of phenol derived from formula (1) = E / {(D / 9)+E}×100···Mathematical formula (9)

[0303] The proportion (mol%) of repeating units of phenol derived from formula (2) = (D / 9) / {(D / 9)+E}×100··· Mathematical formula (10)

[0304] (5) The molar ratio of repeating units derived from impurity A in the modified polyphenylene ether relative to the total repeating units of phenol derived from formula (1), repeating units of phenol derived from formula (2), and repeating units derived from impurity A.

[0305] The unmodified polyphenylene ethers obtained in the examples and comparative examples were dissolved in the assay solvent (deuterated chloroform with 1 drop of heavy water added to remove the hydroxyl groups), and tetramethylsilane was used as an internal standard for analysis. 1 ¹H-NMR determination (JEOL 500MHz). For the determination, the polyphenylene ether was pre-treated at 80°C and 1 mmHg for 8 hours to remove volatile components such as toluene and water, and was then measured as unmodified polyphenylene ether in a dry state. The signals of the units derived from formulas (1), (2), and impurity A (phenol) were identified, and their respective proportions were calculated.

[0306] For example, in the unmodified polyphenylene ethers obtained in the examples and comparative examples, the signals from the repeating unit of phenol derived from formula (1), i.e., the structure derived from 2,6-dimethylphenol (2,6-dimethylphenylene unit), the repeating unit of phenol derived from formula (2), i.e., the structure derived from 2-tert-butyl-5-methylphenol (2-tert-butyl-5-methylphenylene unit), the partial structure selected from the group consisting of formulas (4), (5), (6), or (7), i.e., the structure derived from methacryloyl, and the repeating unit derived from impurity A, i.e., R in formula (11) 11 =Methyl, R 12 The signal attribution method for the repeating unit with z=0 (=hydrogen atom) is analyzed as follows. The peaks derived from the repeating units of each phenol appear in the following regions.

[0307] Derived from 2,6-dimethylphenylene unit, 2-tert-butyl-5-methylphenylene unit, and R in formula (11) 11 =Methyl, R 12 = Hydrogen atom, repeating unit of z=0, peaks from the hydrogen atom of the methyl group (6H, 3H, 12H, 3H respectively): 1.60–2.50 ppm (excluding the peak from the hydrogen atom of the methyl group of toluene).

[0308] The peak (9H) of the tert-butyl group of the 2-tert-butyl-5-methylphenylene unit originating from hydrogen atoms: 1.00–1.52 ppm (excluding the peak originating from hydrogen atoms from water).

[0309] R in equation (11) 11 =Methyl, R 12 =Hydrogen atom, the peak (4H) of the repeating unit methyl group with z=0: 7.35 ppm

[0310] Peak (1H) originating from one hydrogen atom of the methylene group of methacryloyl group: 4.4–5.8 ppm

[0311] By investigating the integral value of the above signal, the integral value of each proton of the peak from the hydrogen atom of the methyl group of the 2,6-dimethylphenylene unit can be obtained by the following mathematical formula (11).

[0312] E={C-3×(D / 9)-12×(F / 4)-3×(H / 1)} / 6···Mathematical expression (11)

[0313] Integral values ​​of the peaks originating from the methyl groups of the 2,6-dimethylphenylene unit and the 2-tert-butyl-5-methylphenylene unit.

[0314] D: Integral value of the peak originating from the tert-butyl group of the 2-tert-butyl-5-methylphenylene unit.

[0315] F: R in equation (11) 11 =Methyl, R 12 =Integral value of the peak originating from hydrogen atoms in the repeating unit of the benzene ring with hydrogen atoms at z=0

[0316] E: Integral value per proton of the peak originating from the methyl group of the 2,6-dimethylphenylene unit.

[0317] H: The integral value of the peak originating from one hydrogen atom of the methylene group of methacryloyl group.

[0318] Furthermore, R in equation (11) can be calculated using the following mathematical formula (12). 11 =Methyl, R 12 = The proportion of hydrogen atoms and z=0 structures (mol%).

[0319] R in equation (11) 11 =Methyl, R 12 = The proportion of hydrogen atoms and repeating units with z=0 (mol%) = (F / 4) / {(D / 9)+E+(F / 4)}×100··· Mathematical formula (12)

[0320] (6) Specific viscosity (ηsp / c)

[0321] Prepare a 0.5 g / dL chloroform solution of polyphenylene ether, and determine the specific viscosity (ηsp / c) (dL / g) at 30°C using an Ubbelohde viscometer.

[0322] (7) Average number of hydroxyl groups in polyphenylene ether

[0323] Weigh 5.0 mg of polyphenylene ether. Then dissolve the weighed polyphenylene ether in 25 mL of dichloromethane. Add 150 μL of ethanol solution containing 2% tetraethylammonium hydroxide (TEAH) relative to 2.0 mL of the prepared solution, and measure the absorbance (Abs) at 318 nm using a UV spectrophotometer (Hitachi, U-3210 type) (using an absorbance measuring cuvette with a cuvette length of 1 cm). Then, based on the measurement result, calculate the hydroxyl equivalent obtained from the absorbance using the following mathematical formula (13). In addition, calculate the average number of hydroxyl groups per molecule of polyphenylene ether using the number-average molecular weight obtained by gel permeation chromatography (details are described in (8) below).

[0324] The hydroxyl equivalent (g / mol) obtained from absorbance = [(ε×5) / (25×Abs)]···Mathematical formula (13)

[0325] (Here, ε represents the absorptivity, which is 4700 L / mol·cm.)

[0326] Average number of hydroxyl groups per molecule of polyphenylene ether (hydroxyl groups / molecule) = (number average molecular weight obtained by gel permeation chromatography) / (hydroxyl equivalent obtained from absorbance) ... mathematical formula (14)

[0327] (8) Number-average molecular weight (Mn)

[0328] The measuring apparatus used was a gel permeation chromatography System21 manufactured by Showa Denko Corporation. A calibration curve was prepared using standard polystyrene and ethylbenzene, and the number-average molecular weight (Mn) of the obtained modified polyphenylene ether was determined using this calibration curve. Standard polystyrene with molecular weights of 3,650,000, 2,170,000, 1,090,000, 681,000, 204,000, 52,000, 30,200, 13,800, 3,360, 1,300, and 550 was used.

[0329] Regarding the column, a column consisting of two K-805L columns manufactured by Showa Denko Co., Ltd. connected in series was used. Chloroform was used as the solvent, and the measurement was conducted at a solvent flow rate of 1.0 mL / min and a column temperature of 40°C. A 1 g / L chloroform solution of modified polyphenylene ether was prepared as the sample for the test. Regarding the UV wavelength of the detection section, it was 254 nm for standard polystyrene and 283 nm for polyphenylene ether.

[0330] Based on the above measurement data, the number-average molecular weight (Mn) (g / mol) was calculated according to the proportion of the peak area of ​​the curve representing the molecular weight distribution obtained by GPC.

[0331] (9) Long-term solubility relative to methyl ethyl ketone (MEK solubility)

[0332] Weigh 1.5g of polyphenylene ether and 8.5g of methyl ethyl ketone into a transparent glass screw tube. Mix at 20°C using a stir bar and a magnetic stirrer. After 1 day, the solution is judged as follows: "0" (good) if it remains transparent; "×" (poor) if it is significantly insoluble or contains a large amount of insoluble components; and "△" if it contains only a small amount of insoluble matter (slight turbidity).

[0333] (10) Long-term solubility relative to toluene (TL solubility)

[0334] Weigh 2g of polyphenylene ether and 8g of toluene into a transparent glass screw tube. Mix at 20°C using a stir bar and a magnetic stirrer. After 1 day, the following conditions are considered: if the solution remains transparent, it is marked as "〇" (good); if it is significantly undissolved or contains a large amount of insoluble components, it is marked as "×" (poor); if it contains only a small amount of insoluble matter (slight turbidity), it is marked as "△".

[0335] (11) Dielectric loss tangent of the cured thermosetting composition

[0336] The dielectric loss tangent of the laminates manufactured in the examples and comparative examples was measured at 10 GHz using the cavity resonator method. A network analyzer (N5230A, manufactured by Agilent Technologies) and a cavity resonator (Cavity Resornator CP series) manufactured by Kanto Electronics Application Development Co., Ltd. were used as the measuring apparatus. The laminates were cut into strips approximately 2 mm wide, 50 mm long, and 0.5 mm thick, with the warp of the glass cloth as the long side. After drying in an oven at 105°C ± 2°C for 2 hours, they were then left to stand at 23°C and 50 ± 5% relative humidity for 24 ± 5 ​​hours. The dielectric loss tangent was then measured using the aforementioned measuring apparatus at 23°C and 50 ± 5% relative humidity.

[0337] The manufacturing methods of polyphenylene ether in each embodiment and comparative example are described below.

[0338] (Example 1)

[0339] A 40-liter jacketed polymerization reactor, equipped with a nozzle for introducing oxygen-containing gas at the bottom, a turbine agitator, and a baffle plate, and with a reflux cooler on the exhaust line at the top, was used. While nitrogen was being blown into the reactor at a flow rate of 17.1 L / min, 2.4 g of divalent copper oxide, 18.1 g of a 47% (w / w) aqueous solution of hydrogen bromide, 5.8 g of di-tert-butylethylenediamine, 28.1 g of di-n-butylamine, 85.6 g of butyldimethylamine, 17.9 kg of toluene, 1497 g of 2,6-dimethylphenol, and 503 g of 2-tert-butyl-5-methylphenol were added to form a homogeneous solution. Next, dry air was introduced into the reactor at a rate of 10.5 L / min using a nozzle to initiate polymerization. The polymerization was carried out for 120 minutes to obtain the polymerization mixture. It should be noted that the internal temperature was controlled at 20°C during polymerization. At the end of polymerization, the polymer mixture (polymer solution) is in a homogeneous solution state.

[0340] Stop the flow of dry air and add 25.9 g of sodium ethylenediaminetetraacetic acid (EDTA-4) (a reagent prepared by Tongren Chemical Research Institute) to the polymerization mixture as an aqueous solution in 2 kg of water. Stir the polymerization mixture at 70°C for 150 minutes, then let it stand for 20 minutes to separate the organic and aqueous phases via liquid-liquid separation. Concentrate the organic phase using a rotary evaporator until the polymer concentration reaches 25% by mass.

[0341] The above solution was mixed with methanol at a methanol-to-polymer solution ratio of 6 to precipitate the polymer. The precipitated polyphenylene ether was obtained by vacuum filtration using a glass filter. The precipitated polyphenylene ether was then further washed with methanol at a methanol-to-polymer ratio of 3. This washing operation was performed three times. The precipitated polyphenylene ether was then kept at 140°C and 1 mmHg for 120 minutes to obtain dried polyphenylene ether.

[0342] The obtained polyphenylene ether was subjected to various determinations using the methods described above. The analytical results are shown in Table 1.

[0343] (Example 2)

[0344] Except that the phenol raw materials were 1269g of 2,6-dimethylphenol and 731g of 2-tert-butyl-5-methylphenol, the operation was carried out using the same method as in Example 1.

[0345] The results of each analysis are shown in Table 1.

[0346] (Example 3)

[0347] Except that the phenol raw materials were 853g of 2,6-dimethylphenol and 1147g of 2-tert-butyl-5-methylphenol, the operation was carried out using the same method as in Example 1.

[0348] The results of each analysis are shown in Table 1.

[0349] (Example 4)

[0350] Except that the phenol raw materials were 454g of 2,6-dimethylphenol and 1517g of 2-tert-butyl-5-methylphenol, the operation was carried out using the same method as in Example 1.

[0351] The results of each analysis are shown in Table 1.

[0352] (Example 5)

[0353] Except that the phenol raw materials were 765g of 2,6-dimethylphenol, 1142g of 2-tert-butyl-5-methylphenol, and 93g of 2-allylphenol, the operation was carried out using the same method as in Example 1.

[0354] The results of each analysis are shown in Table 1.

[0355] (Example 6)

[0356] Except that the phenol raw materials were 503g of 2,6-dimethylphenol, 1128g of 2-tert-butyl-5-methylphenol, and 369g of 2-allylphenol, the operation was carried out using the same method as in Example 1.

[0357] The results of each analysis are shown in Table 1.

[0358] (Example 7)

[0359] Oxidative polymerization, copper extraction, liquid-liquid separation, and concentration using a rotary evaporator were performed in the same manner as in Example 3, and a polymer solution with a polymer concentration of 25% by mass was used as the stock solution for the modification reaction.

[0360] Using a 500 mL three-necked flask equipped with a nitrogen inlet line at the top of the reactor and a reflux cooler at the exhaust line at the top of the reactor, 200 g of unmodified polyphenylene ether solution and 0.64 g of 4-dimethylaminopyridine were added to the reactor after purging with nitrogen. 21 mL of triethylamine was added using a syringe while stirring. Then, 10.9 mL of methacryloyl chloride was collected in the syringe and added dropwise to the system at room temperature. After the addition was complete, the flask was heated in an oil bath for 1 hour with continuous stirring at 90 °C. The reaction was then further heated in an oil bath under reflux. Heating was stopped after 4 hours following the start of reflux, and the mixture was allowed to return to room temperature before adding 8 g of methanol to stop the reaction. The reaction solution was then filtered through a glass filter to obtain a solution free of the byproduct triethylammonium salt. This solution was mixed with methanol at a methanol-to-polymer solution ratio of 10 to precipitate the polymer. Wet polyphenylene ether was obtained by vacuum filtration through a glass filter. The moistened polyphenylene ether was further cleaned with methanol at a ratio of 2.5:1. This cleaning operation was performed three times. The moistened polyphenylene ether was then kept at 100°C and 1 mmHg for 8 hours to obtain dried polyphenylene ether. The average number of hydroxyl groups in the polyphenylene ether was determined using the above method, confirming that the average number of hydroxyl groups from the polyphenylene ether source was less than 0.2 per molecule. Further... 1 ¹H NMR analysis confirmed the olefinic proton peak of the methacryloyl group, indicating that the hydroxyl group was modified to methacryloyl. The analytical results are shown in Table 2.

[0361] (Example 8)

[0362] Oxidative polymerization, copper extraction, liquid-liquid separation, and concentration using a rotary evaporator were performed in the same manner as in Example 3, and a polymer solution with a polymer concentration of 25% by mass was used as the stock solution for the modification reaction.

[0363] In a 500 mL three-necked flask equipped with a temperature regulator, stirrer, cooling device, and dropping funnel, 200 g of unmodified polyphenylene ether solution, 24 g of chloromethylstyrene (50 / 50 ratio of p-chloromethylstyrene to m-chloromethylstyrene, manufactured by Tokyo Chemical Industry Co., Ltd.), and 1.0 g of tetra-n-butylammonium bromide were added. The mixture was then stirred to dissolve, and the liquid temperature was brought to 85°C. Sodium hydroxide aqueous solution (4.2 g sodium hydroxide / 104 g water) was added dropwise to the mixture over 1 hour, and the mixture was stirred continuously at 85°C for 5 hours. Next, the aqueous layer was removed using a separatory funnel to obtain a toluene layer (polymer solution) containing the polymer. This was mixed with methanol at a ratio of 10 to methanol solution to precipitate the polymer. Wet polyphenylene ether was obtained by vacuum filtration using a glass filter. The moistened polyphenylene ether was further cleaned using a cleaning solvent (methanol:water = 80:20) at a ratio of 2.5 to the moistened polyphenylene ether. After three cleaning operations using the methanol-water mixture, the moistened polyphenylene ether was cleaned again using methanol at a ratio of 2.5 to the moistened polyphenylene ether. After two more cleaning operations using methanol, the moistened polyphenylene ether was kept at 100°C and 1 mmHg for 8 hours to obtain dried polyphenylene ether. The average number of hydroxyl groups in the polyphenylene ether was determined using the above method, confirming that the average number of hydroxyl groups from the polyphenylene ether source was less than 0.2 per molecule. Furthermore, [further details are needed]. 1 ¹H NMR analysis confirmed the presence of proton peaks originating from styrene groups in the 5–7 ppm range, indicating that the hydroxyl groups were modified into styrene groups. The analytical results are shown in Table 2.

[0364] (Example 9)

[0365] The same oxidative polymerization, copper extraction, liquid-liquid separation, and concentration using a rotary evaporator were performed as in Example 3. The mixture was then maintained at 100°C and 1 mmHg for 2 hours to obtain dried polyphenylene ether. This dried polyphenylene ether was used as a raw material for the modification reaction.

[0366] In a 500 mL three-necked flask equipped with a temperature regulator, stirrer, cooling device, and dropping funnel, 50 g of unmodified polyphenylene ether, 150 g of tetrahydrofuran, 12.6 g of allyl bromide, and 0.8 g of benzyltributylammonium bromide were added, and the mixture was stirred at 25 °C. Sodium hydroxide aqueous solution (4.2 g sodium hydroxide / 100 mL water) was added dropwise to the mixture over 60 minutes, and the mixture was further stirred at 25 °C for 12 hours.

[0367] Next, the contents of the flask were neutralized with a 10% hydrochloric acid aqueous solution and then mixed with methanol at a ratio of 10 to the polymer solution to precipitate the polymer. The precipitated polyphenylene ether was obtained by vacuum filtration using a glass filter. The precipitated polyphenylene ether was further cleaned with a cleaning solvent (methanol:water = 80:20) at a ratio of 2.5 to the precipitated polyphenylene ether. After three cleaning operations using the methanol-water mixture, the precipitated polyphenylene ether was cleaned with methanol at a ratio of 2.5 to the precipitated polyphenylene ether. After two more cleaning operations using methanol, the precipitated polyphenylene ether was then kept at 100°C and 1 mmHg for 8 hours to obtain dried polyphenylene ether. The average number of hydroxyl groups in the polyphenylene ether was determined using the above method, confirming that the average number of hydroxyl groups from the polyphenylene ether source was less than 0.2 per molecule. Further processing was then performed. 1 ¹H NMR measurements confirmed allyl-derived proton peaks in the range of 3.5–6.5 ppm, indicating that the hydroxyl group was modified into an allyl group. The analytical results are shown in Table 2.

[0368] (Example 10)

[0369] Oxidative polymerization, copper extraction, liquid-liquid separation, and concentration using a rotary evaporator were performed in the same manner as in Example 5. The mixture was then maintained at 100°C and 1 mmHg for 2 hours to obtain dried polyphenylene ether. Methacrylamide modification was performed in the same manner as in Example 7, except that the dried polyphenylene ether was used as the starting material for the modification reaction. The average number of hydroxyl groups in the polyphenylene ether was determined using the above method, confirming that the average number of hydroxyl groups from the polyphenylene ether source was less than 0.2 per molecule.

[0370] In addition, 1 ¹H NMR measurements confirmed the olefinic proton peak of the methacryloyl group, indicating that the hydroxyl group was modified into a methacryloyl group. The analytical results are shown in Table 2.

[0371] (Example 11)

[0372] Compared to the 79 parts by mass of polyphenylene ether described in Example 7, 20 parts by mass of TAIC (manufactured by Nippon Chemical Co., Ltd.) and 1 part by mass of organic peroxide (Perbutyl P, manufactured by Nippon Yushi Co., Ltd.) were added to toluene, stirred, and dissolved to obtain a varnish (solid content concentration 58% by mass). L-type glass cloth (manufactured by Asahi-Schwebel Co., Ltd., model: 2116) was impregnated with this varnish, and excess varnish was scraped off by passing it through a specified slit. The cloth was then dried in a drying oven at 105°C for a specified time to remove toluene, thereby obtaining a prepreg. The prepreg was cut to a specified size, and the mass of the prepreg was compared with the mass of glass cloth of the same size to calculate the solid content of the thermosetting composition in the prepreg, which was 52% by mass.

[0373] The prepreg is stacked a specified number of sheets, and then copper foil (manufactured by Furukawa Electric Industries, Ltd., 35μm thick, GTS-MP foil) is stacked on both sides of the stacked prepreg and vacuum-pressed in this state to obtain a copper-clad laminate. In this vacuum pressing process, the material is first heated from room temperature at a heating rate of 2°C / min while maintaining a pressure of 40 kg / cm². 2 Under the given conditions, after the temperature reaches 200℃, the pressure is maintained at 40 kg / cm² while keeping the temperature at 200℃. 2 And the time limit is 60 minutes.

[0374] Next, the copper foil is removed from the copper-clad laminate by etching, thereby obtaining the laminate (approximately 0.5 mm thick).

[0375] The results of each analysis are shown in Table 3.

[0376] (Example 12)

[0377] Except for the use of polyphenylene ether as described in Example 10 in the raw materials, the laminate was obtained using the same method as in Example 11.

[0378] The results of each analysis are shown in Table 3.

[0379] (Comparative Example 1)

[0380] A 1.5-liter jacketed reactor was used, equipped with a nozzle for introducing oxygen-containing gas at the bottom, a stirring turbine, and baffles, and a reflux cooler on the exhaust line at the top of the reactor. A pre-prepared mixture of 0.15 g of cuprous oxide and 1.12 g of 47% hydrogen bromide, along with 0.36 g of N,N'-di-tert-butylethylenediamine, 5.31 g of dimethyl-n-butylamine, 1.74 g of di-n-butylamine, and 491.3 g of toluene, was added to the reactor. Next, while vigorously stirring, air was introduced into the reactor at a rate of 1.05 L / min, and oxygen was introduced simultaneously. Over 60 minutes, a mixture of 98.7 g of 2,6-dimethylphenol, 1.34 g of 2-tert-butyl-5-methylphenol, and 400.0 g of toluene was added to the solution. The polymerization temperature was regulated and maintained at 40°C by circulating a heat transfer medium within the jacket. After introducing air for 130 minutes, the air supply was stopped, and the reactor was purged with nitrogen. Then, a 20% methanol solution containing 1.03 g of hydroquinone (a reagent manufactured by Wako Pure Chemical Industries, Ltd.) was added in small, incremental portions. Thirty minutes after adding the hydroquinone methanol solution, 1.61 g of tetrasodium ethylenediaminetetraacetate tetrahydrate (a reagent manufactured by Dojin Chemical Research Institute) was added as an aqueous solution in 200 g of water. Copper extraction was performed at 70°C for 2 hours. The mixture was then separated by static separation into an unmodified polyphenylene ether solution (organic phase) and an aqueous phase containing the transferred catalyst metal. This solution was mixed with methanol at a methanol-to-polymer ratio of 10 to precipitate the polymer. Wet polyphenylene ether was obtained by vacuum filtration using a glass filter. The wet polyphenylene ether was further washed with methanol at a methanol-to-polymer ratio of 2.5. This washing operation was performed three times. The moistened polyphenylene ether was then kept at 140°C and 1 mmHg for 120 minutes to obtain the dried polyphenylene ether.

[0381] The obtained polyphenylene ether was subjected to various determinations using the methods described above. The analytical results are shown in Table 1.

[0382] (Comparative Example 2)

[0383] Except that the phenol raw materials were 1973g of 2,6-dimethylphenol and 26.8g of 2-tert-butyl-5-methylphenol, the operation was carried out using the same method as in Example 1.

[0384] The results of each analysis are shown in Table 1.

[0385] (Comparative Example 3)

[0386] Except that the phenol raw materials were 1740g of 2,6-dimethylphenol and 260g of 2-tert-butyl-5-methylphenol, the operation was carried out using the same method as in Example 1.

[0387] The results of each analysis are shown in Table 1.

[0388] (Comparative Example 4)

[0389] A 40-liter jacketed polymerization reactor, equipped with a nozzle for introducing oxygen-containing gas at the bottom, a turbine agitator, and a baffle plate, and with a reflux cooler on the exhaust line at the top, was used. While blowing nitrogen at a flow rate of 0.5 L / min, 4.57 g of divalent copper oxide, 24.18 g of a 47% (w / w) aqueous solution of hydrogen bromide, 11.00 g of di-tert-butylethylenediamine, 62.72 g of di-n-butylamine, 149.92 g of butyldimethylamine, 20.65 kg of toluene, and 3.12 kg of 2,6-dimethylphenol were added to the reactor to form a homogeneous solution, and the mixture was stirred until the internal temperature of the polymerization reactor reached 25°C. Next, dry air was introduced into the polymerization reactor at a rate of 32.8 NL / min using a nozzle to initiate polymerization. The polymerization mixture was obtained after 140 minutes of drying with air. It should be noted that the internal temperature was controlled at 40°C during polymerization. At the end of polymerization, the polymer mixture (polymer solution) is in a homogeneous solution state.

[0390] Stop the flow of dry air and add 10 kg of a 2.5% by mass aqueous solution of sodium ethylenediaminetetraacetic acid (Dongren Chemical Research Institute reagent) to the polymerization mixture. Stir the polymerization mixture at 70°C for 150 minutes, then let it stand for 20 minutes, and separate it into an organic phase and an aqueous phase by liquid-liquid separation.

[0391] The separated organic phase yielded a toluene solution containing 13.1% by mass of polyphenylene ether. This solution was placed in a jacketed stirred tank, and a heat transfer medium at 120°C was circulated through the jacket for heating. The resulting vapor, primarily composed of toluene, was cooled using a condenser, and the toluene was extracted from the system and concentrated until the polymer concentration in the stirred tank reached 30% by mass.

[0392] Next, the polymer was precipitated by mixing with methanol at a ratio of 1.0 to methanol solution. The precipitated polyphenylene ether was obtained by vacuum filtration using a glass filter. The precipitated polyphenylene ether was then further washed with methanol at a ratio of 2.5 to methanol solution. This washing operation was performed three times. The precipitated polyphenylene ether was then kept at 140°C and 1 mmHg for 120 minutes to obtain dried polyphenylene ether.

[0393] The obtained polyphenylene ether was subjected to various determinations using the methods described above. The results are shown in Table 1.

[0394] (Comparative Example 5)

[0395] A 40-liter jacketed polymerization reactor, equipped with a nozzle for introducing oxygen-containing gas at the bottom, a turbine agitator, and a baffle plate, and with a reflux cooler on the exhaust line at the top, was used. While nitrogen was being blown into the reactor at a flow rate of 0.5 L / min, 4.02 g of divalent copper oxide, 29.876 g of a 47% (w / w) aqueous solution of hydrogen bromide, 9.684 g of di-tert-butylethylenediamine, 46.88 g of di-n-butylamine, 122.28 g of butyldimethylamine, 17.53 kg of toluene, and 1.5 kg of 2,6-dimethylphenol were added to form a homogeneous solution, and the mixture was stirred until the internal temperature of the polymerization reactor reached 25°C. Next, dry air was introduced into the polymerization reactor at a rate of 32.8 NL / min using a nozzle, and a solution consisting of 1.62 kg of 2,6-dimethylphenol and 3.12 kg of toluene was added to the reactor over 30 minutes using a plunger pump. Dry air was introduced for 86 minutes to obtain a polymerization mixture. It should be noted that the internal temperature was controlled at 40°C during polymerization. The polymerization mixture (polymer solution) at the end of polymerization was in a homogeneous solution state. The operation was carried out using the same method as Comparative Example 1.

[0396] The results of each analysis are shown in Table 1.

[0397] (Comparative Example 6)

[0398] The phenol feedstock was 2 kg of 2,6-dimethylphenol. Air supply was stopped 117 minutes after the initial air introduction. Otherwise, the operation was carried out using the same method as in Example 1.

[0399] The results of each analysis are shown in Table 1.

[0400] (Comparative Example 7)

[0401] A 4.1-liter jacketed reactor was used, equipped with a nozzle for introducing oxygen-containing gas at the bottom, a turbine agitator, and baffles; and an exhaust line with a reflux cooler at the top of the reactor. The following solvents were added to the reactor: 0.88 g of copper dihydrate chloride, 3.76 g of 35% hydrochloric acid, 33.57 g of N,N,N',N'-tetramethylpropanediamine, 850 g of n-butanol, 1982 g of methanol, and 630 g of 2,6-dimethylphenol. The weight ratio of the solvents used was n-butanol:methanol = 30:70. Oxygen was then introduced into the reactor at a rate of 410 mL / min using the nozzle while vigorous stirring, and a heat transfer medium was circulated in the jacket to maintain the polymerization temperature at 40°C. The polymerization liquid gradually became a slurry.

[0402] 200 minutes after the initial oxygen introduction, the oxygen-containing gas aeration was stopped. A 50% aqueous solution containing 4.56 g of potassium ethylenediaminetetraacetic acid (Dongjin Chemical Research Institute reagent) was added to the polymerization mixture, followed by the gradual addition of small amounts of a 20% methanol solution containing 8.52 g of hydroquinone (Wako Pure Chemical Industries, Ltd. reagent). The resulting polymerization solution was transferred to a 4.1-liter jacketed reactor equipped with a turbine agitator and baffles, and a reflux cooler on the exhaust line at the top of the reactor. The reaction was carried out at 60°C for 3 hours. After the reaction, the mixture was filtered and washed three times with a washing solution (b) in a mass ratio (b / a) of 4 (methanol washing solution (b) to the polyphenylene ether (a) being washed, to obtain wet polyphenylene ether. The wet polyphenylene ether was then dried under vacuum at 120°C for 4 hours. The analytical results of the obtained polyphenylene ether are shown in Table 1.

[0403] (Comparative Example 8)

[0404] Except that the phenol feedstock is 2 kg of 2-tert-butyl-5-methylphenol, the operation is carried out using the same method as in Example 1.

[0405] The results of each analysis are shown in Table 1.

[0406] (Manufacturing Example 1)

[0407] A 1.5-liter jacketed reactor with a nozzle for introducing oxygen-containing gas, a turbine agitator, and a baffle plate at the bottom, and a reflux cooler on the exhaust line at the top, was used. A pre-prepared mixture of 0.092 g of cuprous oxide and 0.69 g of 47% hydrogen bromide, along with 0.22 g of N,N'-di-tert-butylethylenediamine, 3.27 g of dimethyl-n-butylamine, 1.07 g of di-n-butylamine, 714.65 g of toluene, 65.03 g of 2,6-dimethylphenol, and 14.97 g of 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, was then introduced into the reactor at a rate of 0.84 L / min using the nozzle while vigorous stirring. Simultaneously, a heat transfer medium was circulated within the jacket to maintain the polymerization temperature at 20°C. 150 minutes after the initial air introduction, the air supply was stopped, and the reactor was purged with nitrogen. Then, 0.99 g of tetrasodium ethylenediaminetetraacetate tetrahydrate (a reagent prepared by Tongjin Chemical Research Institute) was added to the polymerization mixture as an aqueous solution of 160 g of water. The mixture was then heated to 70°C and copper extraction was performed at 70°C for 2 hours. Subsequently, the mixture was separated by static separation into an unmodified polyphenylene ether solution (organic phase) and an aqueous phase containing the transferred catalyst metal.

[0408] Using the obtained unmodified polyphenylene ether, modified polyphenylene ether was obtained in the same manner as in Example 7.

[0409] The results of each analysis are shown in Table 2.

[0410] (Comparative Example 10)

[0411] Except for the use of polyphenylene ether as described in Manufacturing Example 1 in the raw materials, the laminate was obtained using the same method as in Example 11.

[0412] The results of each analysis are shown in Table 3.

[0413] (Refer to Example 9)

[0414] A 1.5-liter jacketed reactor was used, equipped with a nozzle for introducing oxygen-containing gas at the bottom, a turbine agitator, and baffles; and an exhaust line with a reflux cooler at the top of the reactor. A pre-prepared mixture of 0.15 g of cuprous oxide and 1.12 g of 47% hydrogen bromide, along with 0.36 g of N,N'-di-tert-butylethylenediamine, 5.31 g of dimethyl-n-butylamine, 1.74 g of di-n-butylamine, 891.3 g of toluene, 50.0 g of 2,6-dimethylphenol, and 50.0 g of 2,5-dimethylphenol were added to the reactor. Air was then introduced into the reactor at a rate of 1.05 L / min using the nozzle while vigorous stirring, and a heat transfer medium was circulated in the jacket to maintain the polymerization temperature at 40°C. 120 minutes after the initial air introduction, the solution became highly viscous, resulting in gelation.

[0415]

[0416]

[0417] [Table 3]

[0418]

[0419] As shown in Tables 1 and 2, based on the comparison with the comparative examples, various polyphenylene ethers with improved solvent solubility in methyl ethyl ketone were obtained by using the polyphenylene ethers of the examples.

[0420] Industrial applicability

[0421] The polyphenylene ether of the present invention has excellent solvent solubility, and therefore has industrial value for use as an electronic material and a modifier.

Claims

1. A polyphenylene ether, characterized in that, The total of 100 mol% of phenol repeating units derived from formula (1) and formula (2) includes 5 mol% to 85 mol% of phenol repeating units derived from formula (1) and 15 mol% to 95 mol% of phenol repeating units derived from formula (2). The total percentage of repeating units of phenol derived from formula (1) and repeating units of phenol derived from formula (2) is more than 75 mol%, relative to 100 mol% of monomer units contained in polyphenylene ether. The specific viscosity (ηsp / c) measured in a chloroform solution with a concentration of 0.5 g / dL at 30℃ was 0.03 dL / g to 0.30 dL / g. [Chemistry 1] In equation (1), R 11 Each is independently a saturated hydrocarbon group with 1 to 6 carbon atoms, with or without substituents; an aryl group with 6 to 12 carbon atoms, with or without substituents; or a halogen atom, R. 12 Each of the following can be independently a hydrogen atom, a hydrocarbon group with 1 to 6 carbon atoms (with or without substituents), an aryl group with 6 to 12 carbon atoms (with or without substituents), or a halogen atom. [Chemistry 2] In equation (2), R 22 Each of the following is independently a hydrogen atom, a saturated or unsaturated hydrocarbon group with or without substituents (1-20 carbon atoms), an aryl group with or without substituents (6-12 carbon atoms), or a halogen atom, with two R atoms. 22 R is not simultaneously a hydrogen atom. 21 The partial structure represented by the following formula (3); [Chemistry 3] In equation (3), R 31 Each is independently a straight-chain alkyl group having 1 to 8 carbon atoms, with or without substituents, or with 2 R groups. 31 A cyclic alkyl structure with 1 to 8 carbon atoms bonded together, R 32 Each is an alkylene group having 1 to 8 carbon atoms, with or without substituents; b is independently 0 or 1; R 33 It is a hydrogen atom, an alkyl group having 1 to 8 carbon atoms with or without substituents, or a phenyl group having or without substituents.

2. The polyphenylene ether as described in claim 1, wherein, The structure represented by equation (3) is tert-butyl.

3. The polyphenylene ether as described in claim 1 or 2, wherein, The average number of hydroxyl groups is less than 2.5 per molecule.

4. The polyphenylene ether as described in claim 1 or 2, wherein, The average number of hydroxyl groups is less than 0.2 per molecule.

5. The polyphenylene ether as claimed in claim 1 or 2, having at least one partial structure selected from the group consisting of formulas (4), (5), (6), and (7), with an average number of hydroxyl groups less than 0.2 per molecule. [Chemistry 4] [Chemistry 5] [Chemistry 6] In equation (6), R 6 It is a saturated or unsaturated hydrocarbon group with 1 to 10 carbon atoms, and the saturated or unsaturated hydrocarbon may also have substituents as long as it meets the condition of 1 to 10 carbon atoms; [Chemistry 7] In equation (7), R 7 It is a divalent hydrocarbon group with 1 to 10 carbon atoms, either saturated or unsaturated. This saturated or unsaturated divalent hydrocarbon can also contain substituents, provided it satisfies the condition of 1 to 10 carbon atoms. R 8 It is a saturated or unsaturated hydrocarbon group consisting of hydrogen atoms or 1 to 10 carbon atoms. The saturated or unsaturated hydrocarbon can also contain substituents as long as it meets the condition of having 1 to 10 carbon atoms.

6. The polyphenylene ether of claim 1 or 2, comprising a repeating unit of a monophenol having at least one unsaturated hydrocarbon group on a carbon atom adjacent to the carbon atom bonded to the hydroxyl group of the phenol.

7. The polyphenylene ether of claim 6, wherein, The monohydric phenol is 2-allylphenol or 2-methyl-6-allylphenol.

8. The polyphenylene ether as described in claim 1 or 2, wherein, In equation (2), R 22 Each is independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.

9. The polyphenylene ether according to claim 1 or 2, wherein, The total of 100 mol% of the repeating units of phenol derived from formula (1) and repeating units of phenol derived from formula (2) includes 5 mol% to 82 mol% of repeating units of phenol derived from formula (1) and 18 mol% to 95 mol% of repeating units of phenol derived from formula (2).

10. The polyphenylene ether according to claim 1 or 2, wherein, The specific viscosity (ηsp / c) is 0.06 dL / g to 0.30 dL / g.

11. The polyphenylene ether according to claim 1 or 2, wherein, In the polyphenylene ether, the terpolymer containing a structure derived from a diphenol of formula (11) is present in a molar percentage of 5 mol% or less relative to 100 mol% of the polyphenylene ether. [Chemistry 14] In equation (11), R 11 and R 12 Similar to equation (1), z is 0 or 1, and Y is any one of the following equations. [Chemistry 15] In the formula, R 41 Each of the following can be independently a hydrocarbon group having 1 to 6 carbon atoms with or without substituents, an aryl group having 6 to 12 carbon atoms with or without substituents, or a halogen atom.

12. The polyphenylene ether of claim 6, wherein, The molar proportion of repeating units derived from the monophenol is 0.1 mol% to 40 mol, relative to the total of repeating units derived from the phenol derived from formula (1) and repeating units derived from the monophenol.

13. The polyphenylene ether according to claim 1 or 2, wherein, The phenol in formula (1) is selected from 2,6-dimethylphenol, 2-methyl-6-ethylphenol, 2,6-diethylphenol, 2-ethyl-6-n-propylphenol, 2-methyl-6-chlorophenol, 2-methyl-6-bromophenol, 2-methyl-6-n-propylphenol, 2-ethyl-6-bromophenol, 2-methyl-6-n-butylphenol, 2,6-di-n-propylphenol, 2-ethyl-6-chlorophenol, 2- One or more of the group consisting of methyl-6-phenylphenol, 2,6-diphenylphenol, 2-methyl-6-tolylphenol, 2,6-dimethyltolylphenol, 2,3,6-trimethylphenol, 2,3-diethyl-6-n-propylphenol, 2,3,6-tributylphenol, 2,6-di-n-butyl-3-methylphenol, 2,6-dimethyl-3-n-butylphenol, and 2,6-dimethyl-3-tert-butylphenol.

14. A method for manufacturing polyphenylene ether, which is the method for manufacturing polyphenylene ether according to any one of claims 1 to 13, comprising the steps of oxidative polymerization of phenol of formula (1) and phenol of formula (2).

15. A polyphenylene ether solution comprising the polyphenylene ether according to any one of claims 1 to 13, and a ketone solvent.

16. A thermosetting composition comprising the polyphenylene ether according to any one of claims 1 to 13.

17. A prepreg comprising a substrate and the thermosetting composition of claim 16.

18. The prepreg of claim 17, wherein, The substrate is glass cloth.

19. A laminate comprising a cured prepreg of claim 17 or 18, and a metal foil.

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