JP2019189686A - Polyphenylene ether and manufacturing method therefor - Google Patents

Abstract

To provide low molecular weight polyphenylene ether with enhanced workability or physical prediction during heat processing and a manufacturing method therefor.SOLUTION: There is provided polyphenylene ether having weight average molecular weight (Mw) of 2500 to 6000, a ratio of number average molecular weight (Mn) and the weight average molecular weight (Mw/Mn) of 1.0 to 2.0, and total number of the formula (1) and terminal groups having a specific amino group of 0.8 or less per 100 of phenylene ether units constituting a resin. There is also provided a manufacturing method of the polyphenylene ether using at least one kind of alcohol solvent having 1 to 10 carbon atoms as a polymerization solvent in a polymerization process, and an amine compound containing practically no primary amine nor secondary monoamine as a polymerization catalyst.SELECTED DRAWING: None

Description

  The present invention relates to polyphenylene ether and a method for producing the same.

  Since polyphenylene ether has excellent high-frequency characteristics, flame retardancy, and heat resistance, it is widely used as a material in the electric / electronic field, automobile field, and other various industrial material fields. Taking advantage of these properties, polyphenylene ether, which has a lower molecular weight and improved solubility in general-purpose solvents, can be used as a composite material or additive to obtain excellent properties in electronic materials or in combination with other resins. The use etc. are examined (for example, patent document 1).

JP 2004-99824 A

Here, in the case of polyphenylene ether, a phenomenon in which the molecular weight increases during heat processing may be observed. For this reason, the molecular design target at the polymerization stage of polyphenylene ether is different from the molecular design target after heat processing, and the molecular weight increase may vary depending on the heating conditions.
In particular, low molecular weight polyphenylene ether has a tendency to significantly change the solubility in a solvent and the glass transition temperature as the molecular weight increases during heat processing as compared to high molecular weight polyphenylene ether. In many cases, it is difficult to perform operations and predict physical properties during processing. Moreover, in low molecular weight polyphenylene ether, an odor may be generated at the time of heat processing, and such odor also deteriorates workability, and improvement of workability at the time of heat processing has been desired.

  Then, this invention is made | formed in view of the said subject, and it aims at providing the low molecular weight polyphenylene ether which improved the workability | operativity at the time of heat processing, and physical property prediction, and its manufacturing method.

（式（１）中、Ｒ₁〜Ｒ₃は、各々独立に、水素原子、アルキル基、置換アルキル基、ハロゲン基、アリール基、及び置換アリール基からなる群より選択され、Ｒ₄、Ｒ₅、は水素であり、Ｒ₆は、アルキル基、置換アルキル基、アルケニル基、置換アルケニル基，アリール基、及び置換アリール基からなる群より選択される。）

（式（２）中、Ｒ₁〜Ｒ₅は、一般式（１）について定義したものと同じであり、Ｒ₇、Ｒ₈は、各々独立に、水素原子、アルキル基、置換アルキル基、アリール基、及び置換アリール基からなる群より選択されるが、同時に水素であることはない。）
［２]
前記一般式(１)及び前記一般式(２)で表される末端基の合計数が、樹脂を構成するフェニレンエーテルユニット１００個あたり０．０１個以上である、上記［１］に記載のポリフェニレンエーテル。
［３]
前記ポリフェニレンエーテルについて、下記の加熱条件での加熱の前後で測定した重量平均分子量の差は１０００以下である、上記［１］又は［２］に記載のポリフェニレンエーテル。
（加熱条件）加熱温度：２３０℃、加熱時間：１０分、加熱圧力：１０ＭＰａ
［４］
分子量が１３０００以上の高分子量成分の含有量が８．０質量％以下であり、分子量が５００未満の低分子量成分の含有量が３．０質量％以下である、上記［１］〜［３］のいずれかに記載のポリフェニレンエーテル。
［５]
前記一般式(２)で表される末端基を実質的に有さない、上記［１］〜［４］のいずれかに記載のポリフェニレンエーテル。
［６]
分子鎖中に一般式（３）で表される二価フェノール化合物に由来する構造単位を有する、上記［１］〜［５］のいずれかに記載のポリフェニレンエーテル。

（式（３）中、Ｒ₉、Ｒ₁₀、Ｒ₁₁、及びＲ₁₂は、それぞれ独立して、水素原子、ハロゲン原子、炭素数１〜７のアルキル基、フェニル基、ハロアルキル基、アミノアルキル基、炭化水素オキシ基、及び、少なくとも２個の炭素原子がハロゲン原子と酸素原子とを隔てているハロ炭化水素オキシ基からなる群より選択され、Ｘは、単結合、２価のヘテロ原子、及び炭素数１〜１２の２価の炭化水素基からなる群より選択される。）
［７］
残存窒素量が３００質量ｐｐｍ以下である、上記［１］〜［６］のいずれかに記載のポリフェニレンエーテル。
［８］
カラーインデックス（Ｃ．Ｉ）値が１．０以下である、上記［１］〜［７］のいずれかに記載のポリフェニレンエーテル。
［９］
総揮発分が０．５質量％未満である、上記［１］〜［８］のいずれかに記載のポリフェニレンエーテル。 The present invention is as follows.
[1]
The weight average molecular weight (Mw) is 2500-6000,
The ratio of the weight average molecular weight to the number average molecular weight (Mn) (Mw / Mn) is 1.0 to 2.0,
The total number of terminal groups represented by the following general formula (1) and general formula (2) is 0.8 or less per 100 phenylene ether units constituting the resin.
A polyphenylene ether characterized by that.

(In Formula (1), R < ₁ > -R < ₃ > is each independently selected from the group which consists of a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen group, an aryl group, and a substituted aryl group, R < ₄ >, R < ₅ > , Is hydrogen, and R ₆ is selected from the group consisting of alkyl groups, substituted alkyl groups, alkenyl groups, substituted alkenyl groups, aryl groups, and substituted aryl groups.)

(In the formula (2), R _{1 to} R ₅ are the same as those defined for the general formula (1), and R ₇ and R ₈ are each independently a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl Selected from the group consisting of a group and a substituted aryl group, but not simultaneously hydrogen.)
[2]
The polyphenylene according to the above [1], wherein the total number of terminal groups represented by the general formula (1) and the general formula (2) is 0.01 or more per 100 phenylene ether units constituting the resin. ether.
[3]
About the said polyphenylene ether, the difference of the weight average molecular weight measured before and behind the heating on the following heating conditions is 1000 or less, The polyphenylene ether as described in said [1] or [2].
(Heating conditions) Heating temperature: 230 ° C., heating time: 10 minutes, heating pressure: 10 MPa
[4]
[1] to [3] above, wherein the content of a high molecular weight component having a molecular weight of 13,000 or more is 8.0% by mass or less, and the content of a low molecular weight component having a molecular weight of less than 500 is 3.0% by mass or less. The polyphenylene ether according to any one of the above.
[5]
The polyphenylene ether according to any one of the above [1] to [4], which does not substantially have a terminal group represented by the general formula (2).
[6]
Polyphenylene ether in any one of said [1]-[5] which has a structural unit derived from the dihydric phenol compound represented by General formula (3) in a molecular chain.

(In Formula (3), R < ₉ >, R < ₁₀ >, R <_11> , and R <_12> are respectively independently a hydrogen atom, a halogen atom, a C1-C7 alkyl group, a phenyl group, a haloalkyl group, an aminoalkyl group. , A hydrocarbonoxy group, and a halohydrocarbonoxy group, wherein at least two carbon atoms separate the halogen atom and the oxygen atom, and X is a single bond, a divalent heteroatom, and (Selected from the group consisting of divalent hydrocarbon groups having 1 to 12 carbon atoms.)
[7]
The polyphenylene ether according to any one of [1] to [6], wherein the residual nitrogen amount is 300 mass ppm or less.
[8]
The polyphenylene ether according to any one of [1] to [7], wherein the color index (C.I) value is 1.0 or less.
[9]
Polyphenylene ether in any one of said [1]-[8] whose total volatile matter is less than 0.5 mass%.

[10]
In the polymerization process of polyphenylene ether,
As the polymerization solvent, at least one kind of alcohol solvent having 1 to 10 carbon atoms is used,
The method for producing a polyphenylene ether according to any one of the above [1] to [9], wherein an amine compound substantially free of a primary amine and a secondary monoamine is used as a polymerization catalyst.

  ADVANTAGE OF THE INVENTION According to this invention, the low molecular weight polyphenylene ether which improved the workability | operativity and physical property prediction at the time of heat processing, and its manufacturing method can be provided.

Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The following embodiment is an exemplification for explaining the present invention, and the present invention is not limited to this embodiment, and the present invention can be appropriately modified within the scope of the gist. Can be implemented.
In the embodiment of the present invention, A (numerical value) to B (numerical value) mean A or more and B or less.

（式（１）中、Ｒ₁〜Ｒ₃は、各々独立に、水素原子、アルキル基、置換アルキル基、ハロゲン基、アリール基、置換アリール基であり、Ｒ₄、Ｒ₅は、水素原子であり、Ｒ₆は、アルキル基、置換アルキル基、アルケニル基、置換アルケニル基，アリール基、及び置換アリール基からなる群より選択される。）

（式（２）中、Ｒ₁〜Ｒ₅は、上記一般式（１）について定義したものと同じであり、Ｒ₇、Ｒ₈は、各々独立に、水素原子、アルキル基、置換アルキル基、アリール基、及び置換アリール基からなる群より選択されるが、同時に水素であることはない。） <Polyphenylene ether>
The polyphenylene ether according to the present embodiment has a weight average molecular weight (Mw) of 2500 to 6000, a ratio of the weight average molecular weight to the number average molecular weight (Mn) (Mw / Mn) is 1.0 to 2.0, The total number of terminal groups represented by the following general formula (1) and general formula (2) is 0.8 or less per 100 phenylene ether units constituting the resin. This makes it possible to obtain polyphenylene ether with improved solubility in general-purpose solvents, etc. by lowering the molecular weight while taking advantage of the excellent high-frequency characteristics, flame retardancy, and heat resistance of polyphenylene ether. With respect to the polyphenylene ether, workability and physical property prediction at the time of heat processing can be improved.

(In Formula (1), R < ₁ > -R < ₃ > is respectively independently a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen group, an aryl group, and a substituted aryl group, and R < ₄ >, R < ₅ > is a hydrogen atom. R ₆ is selected from the group consisting of an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an aryl group, and a substituted aryl group.

(In the formula (2), R ₁ ~R ₅ is the same as defined for the general formula _{(1), R 7, R} 8 are each independently a hydrogen atom, an alkyl group, a substituted alkyl group, (Selected from the group consisting of aryl groups and substituted aryl groups, but not simultaneously hydrogen.)

The polyphenylene ether according to the present embodiment is not particularly limited, but is obtained by polymerizing a phenol compound represented by the following formula (4), and has a structural unit derived from the phenol compound represented by the following formula (4). A homopolymer and / or a copolymer is preferable.

In the formula (4), R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 7 carbon atoms, a phenyl group, a haloalkyl group, an aminoalkyl group, Selected from the group consisting of a hydrocarbonoxy group and a halohydrocarbonoxy group wherein at least two carbon atoms separate a halogen atom and an oxygen atom.

In the formula (4), examples of the halogen atom represented by R ₁₃ , R ₁₄ , R ₁₅ , and R ₁₆ include a fluorine atom, a chlorine atom, and a bromine atom, and a chlorine atom and a bromine atom are preferable.

In the formula (4), the alkyl group represented by R ₁₃ , R ₁₄ , R ₁₅ , and R ₁₆ is preferably a linear or branched chain having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms. And an alkyl group in the form of, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl and the like. Methyl and ethyl are preferable, and methyl is more preferable.
In the formula (4), the alkyl group represented by R ₁₃ , R ₁₄ , R ₁₅ , and R ₁₆ may be substituted with one or more substituents at substitutable positions.

  Examples of such a substituent include a halogen atom (for example, fluorine atom, chlorine atom, bromine atom, etc.), an alkyl group having 1 to 6 carbon atoms (for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl). , Tert-butyl, pentyl, hexyl, etc.), aryl groups (eg, phenyl, naphthyl, etc.), alkenyl groups (eg, ethenyl, 1-propenyl, 2-propenyl, etc.), alkynyl groups (eg, ethynyl, 1-propynyl, etc.) 2-propynyl etc.), aralkyl groups (eg benzyl, phenethyl etc.), alkoxy groups (eg methoxy, ethoxy etc.) and the like.

  Examples of the phenol compound represented by the above formula (4) include o-cresol, 2,6-dimethylphenol, 2-ethylphenol, 2-methyl-6-ethylphenol, 2,6-diethylphenol, 2- n-propylphenol, 2-ethyl-6-n-propylphenol, 2-methyl-6-chlorophenol, 2-methyl-6-bromophenol, 2-methyl-6-isopropylphenol, 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-phenyl Phenol, 2-phenylphenol, 2,6-diphenylphenol, 2,6-bis- (4-fluoropheny ) Phenol, 2-methyl-6-tolylphenol, 2,6-ditolylphenol, 2,5-dimethylphenol, 2,3,6-trimethylphenol, 2,5-diethylphenol, 2-methyl-5-ethyl Phenol, 2-ethyl-5-methylphenol, 2-allyl-5-methylphenol, 2,5-diallylphenol, 2,3-diethyl-6-n-propylphenol, 2-methyl-5-chlorophenol, 2 -Methyl-5-bromophenol, 2-methyl-5-isopropylphenol, 2-methyl-5-n-propylphenol, 2-ethyl-5-bromophenol, 2-methyl-5-n-butylphenol, 2,5 -Di-n-propylphenol, 2-ethyl-5-chlorophenol, 2-methyl-5-phenylphenol 2,5-diphenylphenol, 2,5-bis- (4-fluorophenyl) phenol, 2-methyl-5-tolylphenol, 2,5-ditolylphenol, 2,6-dimethyl-3-allylphenol, 2,3,6-triallylphenol, 2,3,6-tributylphenol, 2,6-di-n-butyl-3-methylphenol, 2,6-di-t-butyl-3-methylphenol, 2 , 6-dimethyl-3-n-butylphenol, 2,6-dimethyl-3-t-butylphenol and the like.

Among the above-mentioned phenol compounds, 2,6-dimethylphenol, 2,6-diethylphenol, 2,6-diphenylphenol, 2,3,6-trimethylphenol, 5-dimethylphenol is preferable, and 2,6-dimethylphenol and 2,3,6-trimethylphenol are more preferable.
In addition, the said phenol compound may be used individually by 1 type, or may be used in combination of 2 or more type.

For example, a method using a combination of 2,6-dimethylphenol and 2,6-diethylphenol, a method using a combination of 2,6-dimethylphenol and 2,6-diphenylphenol, 2,3,6-trimethyl Examples thereof include a method using a combination of phenol and 2,5-dimethylphenol, a method using a combination of 2,6-dimethylphenol and 2,3,6-trimethylphenol, and the like. At this time, the mixing ratio of the phenol compounds to be combined can be arbitrarily selected.
In addition, the phenol compound to be used contains a small amount of m-cresol, p-cresol, 2,4-dimethylphenol, 2,4,6-trimethylphenol, etc., which can be contained as by-products during production. Also good.

In this embodiment, the polyphenylene ether is obtained by copolymerizing a phenol compound represented by the above formula (4) and a divalent phenol compound represented by the following formula (3). You may have the structural unit derived from the bivalent phenolic compound represented.
The divalent phenol compound represented by the above formula (3) includes a corresponding monovalent phenol compound, aldehydes (eg, formaldehyde), ketones (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone). , Cyclohexanone, etc.), or a reaction with a dihalogenated aliphatic hydrocarbon, a reaction between corresponding monohydric phenol compounds, or the like.

In the formula (3), R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 7 carbon atoms, a phenyl group, a haloalkyl group, an aminoalkyl group, Selected from the group consisting of a hydrocarbonoxy group and a halohydrocarbonoxy group wherein at least two carbon atoms separate a halogen atom and an oxygen atom. In formula (3), X is selected from the group consisting of a single bond, a divalent heteroatom, and a divalent hydrocarbon group having 1 to 12 carbon atoms.

  Specifically, examples of the divalent phenol compound represented by the above formula (3) include compounds represented by the following general formula (3-a), formula (3-b), and formula (3-c). Etc.

In Formula (3-a), Formula (3-b), and Formula (3-c), R ₉ , R ₁₀ , R ₁₁ , and R ₁₂ are each independently a hydrogen atom, a halogen atom, or a carbon number of 1 Selected from the group consisting of an alkyl group of ~ 7, a phenyl group, a haloalkyl group, an aminoalkyl group, a hydrocarbonoxy group, and a halohydrocarbonoxy group wherein at least two carbon atoms separate the halogen atom and the oxygen atom. The
In formula (3-a), formula (3-b), and formula (3-c), X is a group consisting of a single bond, a divalent heteroatom, and a divalent hydrocarbon group having 1 to 12 carbon atoms. Selected from.

As typical compounds represented by the above formulas (3-a), (3-b) and (3-c), R ₉ and R ₁₀ are methyl groups, and R ₁₁ and R ₁₂ are hydrogen. , X is a compound in which both aryl groups are directly connected; R ₉ and R ₁₀ are methyl groups, R ₁₁ and R ₁₂ are hydrogen, and X is methylene; R ₉ and R ₁₀ are methyl groups; A compound in which R ₁₁ and R ₁₂ are hydrogen and X is thio; a compound in which R ₉ , R ₁₀ and R ₁₁ are methyl groups, R ₁₂ is hydrogen and X is ethylene; R ₉ and R ₁₀ are methyl groups Wherein R ₁₁ and R ₁₂ are hydrogen and X is isopropylidene; R ₉ and R ₁₀ are methyl groups, R ₁₁ and R ₁₂ are hydrogen, and X is cyclohexylidene; R ₉ and R ₁₀ and R ₁₁ is a methyl group, with R ₁₂ is hydrogen, compound X is directly connected both aryl group; R _9, R ₁₀ and R ₁₁ is a methyl group In R ₁₂ is hydrogen, compounds wherein X is methylene; R _9, R ₁₀ and R ₁₁ is a methyl group, with R ₁₂ is hydrogen, compounds wherein X is ethylene; R _9, R ₁₀ and R ₁₁ is a methyl group Wherein R ₁₂ is hydrogen and X is thio; R ₉ , R ₁₀ and R ₁₁ are methyl groups, R ₁₂ is hydrogen and X is isopropylidene; R ₉ , R ₁₀ , R ₁₁ And R ₁₂ is a methyl group and X is methylene; R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are methyl groups and X is ethylene; R ₉ , R ₁₀ , R ₁₁ and R ₁₂ are A methyl group and X is isopropylidene; and the like, but is not limited thereto.

  When copolymerizing with the dihydric phenol compound represented by the general formula (3), the amount of the dihydric phenol compound of the general formula (3) used with respect to the monohydric phenol compound described in the general formula (4) is not particularly limited. However, it is preferable to set it as 0.1-30 mol% with respect to 100 mol% of monohydric phenol compounds.

Furthermore, in this embodiment, polyphenylene ether can be obtained by copolymerization of the phenol compound represented by the above formula (4) and a polyhydric phenol compound, and can have a structural unit derived from the polyhydric phenol compound. is there.
As the polyhydric phenol compound, for example, a compound having 3 or more and less than 9 phenolic hydroxyl groups in the molecule, and having an alkyl group or an alkylene group at positions 2 and 6 of at least one phenolic hydroxyl group Is mentioned.

  Examples of polyhydric phenol compounds are listed below. 4,4 ′-[(3-hydroxyphenyl) methylene] bis (2,6-dimethylphenol), 4,4 ′-[(3-hydroxyphenyl) methylene] bis (2,3,6-trimethylphenol), 4,4 ′-[(4-hydroxyphenyl) methylene] bis (2,6-dimethylphenol), 4,4 ′-[(4-hydroxyphenyl) methylene] bis (2,3,6-trimethylphenol), 4,4 ′-[(2-hydroxy-3-methoxyphenyl) methylene] bis (2,6-dimethylphenol), 4,4 ′-[(4-hydroxy-3-ethoxyphenyl) methylene] bis (2, 3,6-trimethylethylphenol), 4,4 ′-[(3,4-dihydroxyphenyl) methylene] bis (2,6-dimethylphenol), 4,4 ′-[(3,4) Dihydroxyphenyl) methylene] bis (2,3,6-trimethylphenol), 2,2 ′-[(4-hydroxyphenyl) methylene] bis (3,5,6-trimethylphenol), 4,4 ′-[4 -(4-hydroxyphenyl) cyclohexylidene] bis (2,6-dimethylphenol), 4,4 '-[(2-hydroxyphenyl) methylene] -bis (2,3,6-trimethylphenol), 4, 4 ′-[1- [4- [1- (4-hydroxy-3,5-dimethylphenyl) -1-methylethyl] phenyl] ethylidene] bis (2,6-dimethylphenol), 4,4 ′-[ 1- [4- [1- (4-Hydroxy-3-fluorophenyl) -1-methylethyl] phenyl] ethylidene] bis (2,6-dimethylphenol), 2,6-bis [ 4-hydroxy-3,5-dimethylphenyl) ethyl] -4-methylphenol, 2,6-bis [(4-hydroxy-2,3,6-trimethylphenyl) methyl] -4-methylphenol, 2,6 -Bis [(4-hydroxy-3,5,6-trimethylphenyl) methyl] -4-ethylphenol, 2,4-bis [(4-hydroxy-3-methylphenyl) methyl] -6-methylphenol, 2 , 6-bis [(4-hydroxy-3-methylphenyl) methyl] -4-methylphenol, 2,4-bis [(4-hydroxy-3-cyclohexylphenyl) methyl] -6-methylphenol, 2,4 -Bis [(4-hydroxy-3-methylphenyl) methyl] -6-cyclohexylphenol, 2,4-bis [(2-hydroxy-5-methylpheny L) methyl] -6-cyclohexylphenol, 2,4-bis [(4-hydroxy-2,3,6-trimethylphenyl) methyl] -6-cyclohexylphenol, 3,6-bis [(4-hydroxy-3 , 5-dimethylphenyl) methyl] -1,2-benzenediol, 4,6-bis [(4-hydroxy-3,5-dimethylphenyl) methyl] -1,3-benzenediol, 2,4,6- Tris [(4-hydroxy-3,5-dimethylphenyl) methyl] -1,3-benzenediol, 2,4,6-tris [(2-hydroxy-3,5-dimethylphenyl) methyl] -1,3 Benzenediol, 2,2′-methylenebis [6-[(4 / 2-hydroxy-2,5 / 3,6-dimethylphenyl) methyl] -4-methylphenol], 2,2′- Tylene bis [6-[(4-hydroxy-3,5-dimethylphenyl) methyl] -4-methylphenol], 2,2′-methylene bis [6-[(4 / 2-hydroxy-2,3,5 / 3) , 4,6-trimethylphenyl) methyl] -4-methylphenol], 2,2′-methylenebis [6-[(4-hydroxy-2,3,5-trimethylphenyl) methyl] -4-methylphenol], 4,4′-methylenebis [2-[(2,4-dihydroxyphenyl) methyl] -6-methylphenol], 4,4′-methylenebis [2-[(2,4-dihydroxyphenyl) methyl] -3, 6-dimethylphenol], 4,4′-methylenebis [2-[(2,4-dihydroxy-3-methylphenyl) methyl] -3,6-dimethylphenol], 4,4′-me Renbis [2-[(2,3,4-trihydroxyphenyl) methyl] -3,6-dimethylphenol], 6,6′-methylenebis [4-[(4-hydroxy-3,5-dimethylphenyl) methyl ] -1,2,3-benzenetriol], 4,4′-cyclohexylidenebis [2-cyclohexyl-6-[(2-hydroxy-5-methylphenyl) methyl] phenol], 4,4′-cyclohex Silidenebis [2-cyclohexyl-6-[(4-hydroxy-3,5-dimethylphenyl) methyl] phenol], 4,4′-cyclohexylidenebis [2-cyclohexyl-6-[(4-hydroxy- 2-methyl-5-cyclohexylphenyl) methyl] phenol], 4,4′-cyclohexylidenebis [2-cyclohexyl-6-[(2,3 , 4-trihydroxyphenyl) methyl] phenol], 4,4 ′, 4 ″, 4 ′ ″-(1,2-ethanediylidene) tetrakis (2,6-dimethylphenol), 4,4 ′, 4 ′ ', 4' ''-(1,4-phenylenedimethylidene) tetrakis (2,6-dimethylphenol), and the like, but are not limited thereto.

The number of phenolic hydroxyl groups in the polyhydric phenol compound is not particularly limited as long as it is 3 or more. However, if the number of polyphenylene ether ends is increased, the molecular weight change during heating may be increased. More preferably, it is 3-4.
Further, the alkyl group or alkylene group at the 2-6 position in the polyhydric phenol compound is preferably a methyl group.

  The most preferred polyhydric phenol compounds are 4,4 ′-[(4-hydroxyphenyl) methylene] bis (2,6-dimethylphenol), 4,4 ′-[(3-hydroxyphenyl) methylene] bis (2, 6-dimethylphenol), 4,4 ′-[(4-hydroxyphenyl) methylene] bis (2,3,6-trimethylphenol), 4,4 ′-[(3-hydroxyphenyl) methylene] bis (2, 3,6-trimethylphenol), 4,4 ′, 4 ″, 4 ′ ″-(1,4-phenylenedimethylidene) tetrakis (2,6-dimethylphenol).

The weight average molecular weight (Mw) of the polyphenylene ether of this embodiment is 2,500 to 6,000, preferably 2,700 to 5,000, and more preferably 3,000 to 4,700. When the weight average molecular weight (Mw) is 2,500 or more, excellent high-frequency characteristics, flame retardancy, and heat resistance as a polyphenylene ether resin can be effectively utilized. Moreover, when the weight average molecular weight (Mw) is 6,000 or less, the solubility in general-purpose solvents (for example, toluene, dichloromethane, methyl ethyl ketone, etc.) and the miscibility with other resins can be improved.
In addition, let a weight average molecular weight (Mw) be the value measured by the measuring method in the below-mentioned Example.
The method for controlling the weight average molecular weight (Mw) is not particularly limited. For example, when the polymerization time or the monomer addition time is adjusted, or when the polymerization is performed by a slurry polymerization method, it is more poorly solvent-soluble. It is possible to control such that the weight average molecular weight (Mw) is decreased by increasing the proportion of the solvent having a high value.

The ratio (Mw / Mn) of the weight average molecular weight to the number average molecular weight (Mn) of the polyphenylene ether of this embodiment is 1.0 to 2.0, preferably 1.0 to 1.9, more preferably. Is 1.0 to 1.8. When the ratio of the weight average molecular weight to the number average molecular weight is 2.0 or less, the high-frequency characteristics, flame retardancy, and heat resistance as a polyphenylene ether resin are effectively utilized, while being soluble in general-purpose solvents and other Mixability with resin can be improved.
The lower limit of the ratio of the weight average molecular weight to the number average molecular weight is not particularly limited as long as it is 1.0 or more, and may be 1.3, for example.
In addition, ratio (Mw / Mn) of the weight average molecular weight with respect to a number average molecular weight is generally also called molecular weight distribution.
The method for controlling the ratio of the weight average molecular weight to the number average molecular weight (Mw / Mn) is not particularly limited. For example, polymerization in the production of polyphenylene ether is performed by slurry polymerization or by solution polymerization. It can be controlled depending on whether it is performed.

Although it does not specifically limit about the polyphenylene ether of this embodiment, The difference of the weight average molecular weight before and behind the heating on the following heating conditions (heating temperature: 230 degreeC, heating time: 10 minutes, heating pressure: 10 MPa) is 1000 or less. Preferably, it is 700 or less, more preferably 500 or less. The lower limit of the difference in weight average molecular weight before and after heating under the above heating conditions is not particularly limited, but may be 0 or more. When the difference in weight average molecular weight before and after heating under the heating conditions is within the above range, the increase in molecular weight due to heat processing is suppressed, and the variation in solubility in the solvent and glass transition temperature is small. It is easy to predict the physical properties of polyphenylene ether during heat processing, and workability can be improved.
As described above, since the molecular weight of polyphenylene ether generally increases due to heat processing, the difference in weight average molecular weight before and after heating subtracts the value of weight average molecular weight before heating from the value of weight average molecular weight after heating. Can be obtained. However, since a measurement error or the like may occur, it may be obtained by subtracting the smaller weight average molecular weight value from the larger weight average molecular weight value.
In addition, the heating on the said heating conditions can be performed using a compression molding machine etc., for example. Here, the heating time is a heating time after the temperature of an apparatus such as a compression molding machine reaches 230 ° C. The heating pressure is a gauge pressure, and the pressure applied to the polyphenylene ether may be 10 MPa.

In the polyphenylene ether of this embodiment, the content of a high molecular weight component having a molecular weight of 13,000 or more is preferably 8.0% by mass or less, more preferably 6.0% by mass or less, and still more preferably 5. 0% by mass or less. When the upper limit value of the content of the high molecular weight component is within this range, the solubility of polyphenylene ether in a general-purpose solvent is more excellent, and the miscibility with other resins can be effectively enhanced. In addition, when the amine bonded to the polyphenylene ether terminal is removed by heat processing and the molecular weight increases, the higher the molecular weight component, the greater the change in molecular weight. Is preferably within this range.
The lower limit of the content of the high molecular weight component having a molecular weight of 13,000 or more is not particularly limited, and may be 0% by mass or more, and is preferably lower, that is, closer to 0% by mass.

In the polyphenylene ether of the present embodiment, the content of the low molecular weight component having a molecular weight of less than 500 is preferably 3.0% by mass or less, more preferably 2.0% by mass or less from the viewpoint of increasing the purity of the resin. More preferably, it is 1.0 mass% or less. When the upper limit of the content of the low molecular weight component is within this range, it is a high-purity polyphenylene ether having a low content of undesired quanta (oligomer), and it is possible to suppress deterioration of physical properties due to heat processing.
The lower limit of the content of the low molecular weight component having a molecular weight of less than 500 is not particularly limited and may be 0% by mass or more, and is preferably lower, that is, closer to 0% by mass.

About the polyphenylene ether of this embodiment, the said molecular weight is a polystyrene conversion molecular weight, and can be measured by a gel permeation chromatography (GPC). Moreover, content of a high molecular weight component and a low molecular weight component can be calculated from the ratio of the peak area based on the curve which shows the molecular weight distribution obtained by GPC.
In addition, the polystyrene conversion molecular weight of polyphenylene ether, and the contents of the high molecular weight component and the low molecular weight component can be more specifically determined by the methods described in the examples below.

  In the method for producing polyphenylene ether of the present embodiment, a method for controlling the high molecular weight component having a molecular weight of 13,000 or more and the low molecular weight component having a molecular weight of less than 500 to a specific content is not particularly limited. Examples include adjusting the ratio of the poor solvent and the good solvent in the solvent and the cleaning solvent, and increasing or decreasing the amount of the cleaning solvent and the number of times of cleaning.

Here, in the polyphenylene ether of this embodiment, the total number of terminal groups represented by the general formula (1) and the general formula (2) is 0.8 or less per 100 phenylene ether units constituting the resin. .

In the above formula (1), R _{1 to} R ₃ are each independently selected from the group consisting of a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen group, an aryl group, and a substituted aryl group. R ₄ and R ₅ are hydrogen atoms. R ₆ is selected from the group consisting of alkyl groups, substituted alkyl groups, alkenyl groups, substituted alkenyl groups, aryl groups, and substituted aryl groups.
R _{1 to} R ₃ are preferably a hydrogen atom or an alkyl group, more preferably R ₁ and R ₃ are hydrogen, and R ₂ is an alkyl group. R ₆ is preferably an alkyl group or a substituted alkyl group, and more preferably an alkyl group.

In the above formula (2), R _{1 to} R ₅ are the same as those defined for the general formula (1), and R ₇ and R ₈ are each independently a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl Selected from the group consisting of a group and a substituted aryl group, but not simultaneously a hydrogen atom.
R ₇ and R ₈ are preferably an alkyl group or an aryl group, more preferably an alkyl group.

In the formulas (1) and (2), an alkyl group can be selected in R _{1 to} R ₃ and R _{6 to} R ₈ , and the alkyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 6 carbon atoms. 3, a linear or branched alkyl group, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, etc. Ethyl is preferred and methyl is more preferred.
In the above formulas (1) and (2), in R _{1 to} R ₃ and R _{6 to} R ₈ , a substituted alkyl group, a substituted alkenyl group, or a substituted aryl group can be selected. It means that it may be substituted with one or more substituents at substitutable positions.

  Examples of such a substituent include a halogen atom (for example, fluorine atom, chlorine atom, bromine atom, etc.), an alkyl group having 1 to 6 carbon atoms (for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl). , Tert-butyl, pentyl, hexyl, etc.), aryl groups (eg, phenyl, naphthyl, etc.), alkenyl groups (eg, ethenyl, 1-propenyl, 2-propenyl, etc.), alkynyl groups (eg, ethynyl, 1-propynyl, etc.) 2-propynyl etc.), aralkyl groups (eg benzyl, phenethyl etc.), alkoxy groups (eg methoxy, ethoxy etc.) and the like.

In the polyphenylene ether of the present embodiment, the total number of terminal groups represented by the general formula (1) and the general formula (2) is 0.8 or less per 100 phenylene ether units constituting the resin. Workability and physical property prediction during heat processing can be improved.
Specifically, by setting the total number of terminal groups within a predetermined range, it is possible to suppress an increase in the molecular weight of the polyphenylene ether due to reaction of the terminals during heat processing. Therefore, it is possible to suppress changes in solubility in a solvent and glass transition temperature, and it is possible to improve workability and physical property prediction during heat processing.
In particular, the amino group of the terminal group represented by the general formula (2) is eliminated at the time of heat processing, and becomes an odor at the time of heat processing, which may lead to deterioration of workability. Therefore, by setting the total number of terminal groups, particularly the number of terminal groups represented by the general formula (2) within a predetermined range, it is possible to suppress odor during heat processing, and to improve workability during heat processing. Can be improved.

  In addition, the total number of terminal groups represented by the general formula (1) and the general formula (2) is preferably 0.6 or less, more preferably 0.4 per 100 phenylene ether units. It is as follows.

  The total number of terminal groups represented by general formula (1) and general formula (2) is preferably as small as possible in polyphenylene ether from the viewpoint of improving workability and physical property prediction during heat processing, From the viewpoint of obtaining a polyphenylene ether having an excellent color tone, the total number of terminal groups is preferably more than 0 per 100 phenylene ether units constituting the end group, and more preferably 0.01 or more. More specifically, in the polyphenylene ether intermediate during polymerization, a substituent added to the aromatic ring at the terminal may be activated to cause a side reaction, thereby causing the polyphenylene ether to be colored. However, if, for example, a solvent or the like is added to the activated site of the polyphenylene ether intermediate during polymerization (for example, alkoxy or amine is added), side reactions that cause coloring can be suppressed. That is, when the total number of terminal groups is 0 per 100 constituting phenylene ether units, side reactions that cause coloration occur, while the total number of end groups is per 100 constituting phenylene ether units. If it exceeds 0, the side reaction which causes coloring can be suppressed.

In addition, when the total number of the terminal groups is less than 0.01 per 100 phenylene ether units constituting the terminal group, it is difficult to cause a change in molecular weight or generation of odor during the heat processing. The total number of groups can be 0.01 or more.
The ratio of the unit substituted with the alkoxy group at the end of the polyphenylene ether (general formula (1)) and the unit substituted with the amino group (general formula (2)) is determined by ¹ H-NMR or the like according to the method described in the examples described later. Calculated.

  As described later, the method for controlling the total number of terminal groups represented by the above general formula (1) and general formula (2) has a carbon number of 1 as a polymerization solvent in the polymerization step of the polyphenylene ether production method. It is mentioned that at least one kind of 10 to 10 alcohol solvents is used, and an amine compound substantially free of primary amine and secondary monoamine is used as a polymerization catalyst. The method for controlling the total number of end groups represented by the general formula (1) is such that the number of end groups increases by extending the polymerization time, increasing the oxygen supply amount, or polymerizing at a high temperature. Can be controlled. In addition, the method for controlling the total number of terminal groups represented by the above general formula (2) increases the amount of amine compound added as a catalyst component, or selects an amine compound having a high catalytic ability. By doing so, the number of the terminal groups can be controlled to increase.

  Here, in the polyphenylene ether of the present embodiment, the total number of terminal groups represented by the general formula (2) is preferably 0.1 or less per 100 phenylene ether units constituting, more preferably Is 0.01 or less, more preferably substantially 0, and most preferably 0. Thereby, the odor can be further suppressed during the heat processing while suppressing the molecular weight of the polyphenylene ether from reacting during the heat processing. Here, “substantially” means that the polyphenylene ether of the present embodiment may be contained to the extent that it does not inhibit the effect, but more specifically, the above-mentioned general formula (2) added intentionally. It means that polyphenylene ether having a terminal group represented by the formula is not included.

As an indicator of the purity of polyphenylene ether, the amount of residual nitrogen can be used. By confirming the amount of residual nitrogen in the polyphenylene ether, impurities that cause odors during heat processing such as amine components in the polyphenylene ether can be confirmed. The amount of residual nitrogen can be quantified with a nitrogen measuring device, and specifically can be determined by the method described in the examples described later.
The residual nitrogen amount is preferably 300 mass ppm or less in the polyphenylene ether, more preferably 250 mass ppm or less, and even more preferably 200 mass ppm or less in the polyphenylene ether because it causes odor during heat processing. .

Similarly, since the total volatile content also causes odor during heat processing, the total volatile content in polyphenylene ether is preferably less than 0.5% by mass, more preferably 100% by mass of polyphenylene ether. It is less than 0.1% by mass, and more preferably 0% by mass.
The total volatile content can be specifically obtained by the method described in Examples described later.

The larger the color index (C.I) value, the more colored the polyphenylene ether. The polyphenylene ether of the present embodiment preferably has a color index value of 1.0 or less, more preferably 0.6 or less, and even more preferably 0.5 or less, from the viewpoint of toning properties.
Note that C.I. The I value can be obtained by the method described in Examples described later.

Here, the polyphenylene ether of the present embodiment may be either powdery or granular, but is preferably powdery. When the polyphenylene ether of this embodiment is in a powder form, the average particle size is preferably 500 μm to 5 μm from the viewpoint of shortening the dissolution time in a solvent and handling properties.
In addition, let the said average particle diameter be the median cumulative value (median diameter) calculated | required from the cumulative curve of the particle size distribution of the volume average particle diameter measured by the laser diffraction scattering method. More specifically, it can be determined by the method described in Examples described later.

[Production method of polyphenylene ether]
The method for producing the polyphenylene ether of the present embodiment is not particularly limited, but in the polyphenylene ether polymerization step, at least one alcohol solvent having 1 to 10 carbon atoms is used as a polymerization solvent, and a polymerization catalyst is used. As an amine compound, it is preferable to use an amine compound substantially free of a primary amine and a secondary monoamine. By this production method, a low molecular weight polyphenylene ether having improved workability and physical property prediction during heat processing can be obtained.

[[Polymerization step]]
Here, in the method for producing polyphenylene ether of the present embodiment, it is preferable to use an alcohol solvent as a polymerization solvent in the polymerization step. By using an alcohol solvent in the polymerization step, the solvent is contained in the obtained polyphenylene ether. It is difficult to remain and volatile components can be reduced. Therefore, the odor at the time of heat processing of polyphenylene ether can be suppressed, and the workability at the time of heat processing can be improved.
In the polymerization process of polyphenylene ether, instead of an alcohol solvent as a polymerization solvent, for example, when an aromatic hydrocarbon having a relatively high affinity with polyphenylene ether is used, the solvent in the obtained polyphenylene ether is changed. It is difficult to remove sufficiently, and the residual volatile components may become high. In addition, when relatively high aromatic hydrocarbons are used, the polyphenylene ether obtained in a solution state of the polymerization product tends to contain many quantifiers (oligomers). May decrease.

In the method for producing polyphenylene ether of the present embodiment, in the polymerization step, the good solvent of polyphenylene ether as the polymerization solvent is preferably 5% by mass or less, more preferably 2% by mass or less in 100% by mass of the polymerization solvent. More preferably 1% by mass or less, and particularly preferably 0% by mass. When the content of the good solvent in the polymerization solvent is within the above range, the odor during the heat processing of polyphenylene ether can be suppressed, and the workability during the heat processing can be improved.
Here, the good solvent of polyphenylene ether is a solvent that can dissolve polyphenylene ether. Examples of such solvents include benzene, toluene, xylene (o-, m-, and p-isomers). And aromatic hydrocarbons such as ethylbenzene and styrene; halogenated hydrocarbons such as chloroform, methylene chloride, 1,2-dichloroethane, chlorobenzene and dichlorobenzene; and nitro compounds such as nitrobenzene. In addition, although they have some poor solvent properties, those classified as good solvents include aliphatic hydrocarbons such as pentane, hexane, heptane, cyclohexane and cycloheptane; esters such as ethyl acetate and ethyl formate Ethers such as tetrahydrofuran and diethyl ether; dimethyl sulfoxide and the like.

In the method for producing polyphenylene ether of the present embodiment, it is preferable to use a solvent consisting only of an alcohol solvent as a polymerization solvent in the polymerization step. For example, a polyphenylene ether poor solvent (other than an alcohol solvent) is 10% in the polymerization solvent. It may be contained if it is not more than mass%, preferably not more than 5 mass%.
In addition, the poor solvent of polyphenylene ether is a solvent which does not dissolve polyphenylene ether at all or can be slightly dissolved, and examples thereof include ethers and ketones.

  In the method for producing polyphenylene ether of this embodiment, it is preferable to use a polymerization solvent containing at least one alcohol solvent having 1 to 10 carbon atoms, and at least one alcohol solvent having 1 to 10 carbon atoms. More preferably, it consists of As the alcohol solvent having 1 to 10 carbon atoms, methanol, ethanol, propanol, butanol, pentanol, hexanol and the like are preferable, and methanol is more preferable. Especially, as said alcohol solvent, what contains 50-100 mass% of methanol in 100 mass% of alcohol solvents, and contains 0-50 mass% of C2-C10 alcohol is preferable.

  As the polymerization catalyst used in the present embodiment, a known catalyst system that can be generally used for production of polyphenylene ether can be used. As a generally known catalyst system, one comprising a transition metal ion having oxidation-reduction ability and an amine compound capable of complexing with the transition metal ion is known. For example, the catalyst system comprises a copper compound and an amine compound. A catalyst system, a catalyst system comprising a manganese compound and an amine compound, a catalyst system comprising a cobalt compound and an amine compound, and the like. Since the polymerization reaction proceeds efficiently under some alkaline conditions, some alkali or further amine compound may be added thereto.

  The polymerization catalyst suitably used in the present embodiment is a catalyst comprising a copper compound, a halogen compound, and an amine compound substantially free of a primary amine and a secondary monoamine as a constituent component of the catalyst, more preferably And a catalyst containing a diamine compound represented by the general formula (5) as an amine compound. When an amine compound containing a primary amine or a secondary monoamine is used as the polymerization catalyst, the primary amine or secondary monoamine is added to the terminal of the polyphenylene ether obtained after the polymerization, and the general formula ( The end group represented by 2) may be produced, and in the present embodiment, it is obtained after polymerization by using an amine compound substantially free of a primary amine and a secondary monoamine as a polymerization catalyst. It is possible to prevent the terminal group represented by the general formula (2) described above from occurring at the terminal of the polyphenylene ether. Therefore, workability and physical property prediction at the time of heat processing can be improved for the polyphenylene ether obtained after polymerization.

（式中、Ｒ₁₃，Ｒ₁₄，Ｒ₁₅，Ｒ₁₆は、それぞれ独立に、水素原子、炭素数１から６の直鎖状または分岐状アルキル基であり、全てが同時に水素原子ではない。Ｒ₁₇は、炭素数２から５の直鎖状またはメチル分岐を持つアルキレン基である。）

(In the formula, R ₁₃ , R ₁₄ , R ₁₅ , and R ₁₆ are each independently a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, and all are not hydrogen atoms at the same time. ₁₇ is a C2-C5 linear or methyl branched alkylene group.)

  Examples of the copper compounds of the catalyst component described here are listed. As a suitable copper compound, a cuprous compound, a cupric compound or a mixture thereof can be used. Examples of the cupric compound include cupric chloride, cupric bromide, cupric sulfate, and cupric nitrate. Moreover, as a cuprous compound, cuprous chloride, cuprous bromide, cuprous sulfate, cuprous nitrate, etc. can be illustrated, for example. Among these, particularly preferred metal compounds are cuprous chloride, cupric chloride, cuprous bromide, and cupric bromide. These copper salts may be synthesized at the time of use from a halogen or an acid corresponding to an oxide (for example, cuprous oxide), carbonate, hydroxide or the like. The method often used is a method of preparing a mixture of the above-described cuprous oxide and hydrogen halide (or a solution of hydrogen halide).

Examples of the halogen compound include hydrogen chloride, hydrogen bromide, hydrogen iodide, sodium chloride, sodium bromide, sodium iodide, potassium chloride, potassium bromide, potassium iodide, tetramethylammonium chloride, and tetramethylammonium bromide. Tetramethylammonium iodide, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide and the like. These can be used as an aqueous solution or a solution using an appropriate solvent. These halogen compounds may be used alone as a component or in combination of two or more. Preferred halogen compounds are an aqueous solution of hydrogen chloride and an aqueous solution of hydrogen bromide.
Although the usage-amount of these compounds is not specifically limited, 2 times or more and 20 times or less are preferable as a halogen atom with respect to the molar amount of a copper atom, As preferable usage-amount of a copper atom with respect to 100 mol of phenol compounds to be used Is in the range of 0.02 to 0.6 mol.

  Next, the example of the diamine compound of a catalyst component is enumerated. 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-ethylethylenediamine, N, N-dimethyl-N′-ethylethylenediamine N, N′-dimethyl-N-ethylethylenediamine, Nn-propylethylenediamine, N, N′-n-propylethylenediamine, Ni-propylethylenediamine, N, N′-i-propylethylenediamine, Nn -Butylethylenediamine, N N'-n-butylethylenediamine, Ni-butylethylenediamine, N, N'-i-butylethylenediamine, Nt-butylethylenediamine, N, N'-t-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, and the like. Preferred diamine compounds for this embodiment are those in which the alkylene group connecting two nitrogen atoms has 2 or 3 carbon atoms. Although the usage-amount of these diamine compounds is not specifically limited, The range of 0.01 mol to 10 mol is preferable with respect to 100 mol of phenol compounds used normally.

  A tertiary monoamine compound can also be included as a constituent component of the polymerization catalyst in the present embodiment. The tertiary monoamine compound is an aliphatic tertiary amine including an alicyclic tertiary amine. Examples include trimethylamine, triethylamine, tripropylamine, tributylamine, triisobutylamine, dimethylethylamine, dimethylpropylamine, allyldiethylamine, dimethyl-n-butylamine, diethylisopropylamine, N-methylcyclohexylamine and the like. These tertiary monoamines may be used alone or in combination of two or more. Although the usage-amount of these is not specifically limited, The range of 15 mol or less is preferable with respect to 100 mol of phenol compounds used normally.

  In this embodiment, a primary amine and a secondary monoamine are not substantially contained as a component of the polymerization catalyst. Examples of secondary monoamines include, but are not limited to, dimethylamine, diethylamine, di-n-propylamine, di-i-propylamine, di-n-butylamine, di-i-butylamine, Di-t-butylamine, dipentylamines, dihexylamines, dioctylamines, didecylamines, dibenzylamines, 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) ) Ethanol Emissions, N- ethylaniline, N- butylaniline, N- methyl-2-methylaniline, N- methyl-2,6-dimethylaniline, diphenylamine, and the like. “Substantially free” with respect to the primary amine and the secondary monoamine means that the primary amine and the secondary monoamine may be contained to the extent that the effects of the polyphenylene ether of the present embodiment are not inhibited. Specifically, it is preferably in the range of 1 mol or less with respect to 100 mol of the phenol compound that is usually used, more preferably in the range of 0.5 mol or less with respect to 100 mol of the phenol compound. This means that it does not contain primary amines or secondary monoamines that are added sterically.

  In the present embodiment, there is no limitation on adding a surfactant that has been conventionally known to have an effect of improving polymerization activity. Examples of such a surfactant include trioctylmethylammonium chloride known under the trade names of Aliquat 336 and Capriquat. The amount used is preferably within a range not exceeding 0.1% by mass relative to 100% by mass of the total amount of the polymerization reaction mixture.

  As the oxygen-containing gas in the polymerization of the present embodiment, pure oxygen, oxygen and an inert gas such as nitrogen mixed at an arbitrary ratio, air, and further an inert gas such as air and nitrogen are arbitrarily selected. The thing etc. which were mixed in the ratio of can be used. The system pressure during the polymerization reaction is normal pressure, but it can be used under reduced pressure or increased pressure as necessary.

  The temperature of the polymerization is not particularly limited, but if it is too low, the reaction does not proceed easily, and if it is too high, the reaction selectivity may be reduced and a high molecular weight component may be generated, so 20 to 60 ° C., preferably 30 to 50 ° C. It is in the range of ° C.

  In the method for producing polyphenylene ether of the present embodiment, it is preferable to perform polymerization in a slurry state during polymerization of polyphenylene ether (also referred to as “slurry polymerization” in this specification). By producing by slurry polymerization, volatile components in the obtained polyphenylene ether can be reduced.

[[Copper extraction and by-product removal step]]
In the present embodiment, the post-treatment method after completion of the polymerization reaction is not particularly limited. Usually, an acid such as hydrochloric acid or acetic acid, or ethylenediaminetetraacetic acid (EDTA) and a salt thereof, nitrilotriacetic acid and a salt thereof are added to the reaction solution to deactivate the catalyst. A method for removing a by-product of a dihydric phenol produced by polymerization of polyphenylene ether can also be performed using a conventionally known method. If the metal ion which is a catalyst is in a substantially deactivated state as described above, it is decolorized only by heating the mixture. A method of adding a necessary amount of a known reducing agent is also possible. Known reducing agents include hydroquinone, sodium dithionite, and the like.

[[Washing process]]
In the polyphenylene ether production method of the present embodiment, the precipitated polyphenylene ether is washed with a poor solvent (including an alcohol solvent) as a main component used for polymerization for the purpose of removing a catalyst and a high boiling point solvent. Also good.
In this washing step, for example, by separating the slurry obtained in the precipitation step into a solid and liquid, it is separated into a solvent and a wet polyphenylene ether. Dry the wet polyphenylene ether.

  If necessary, before the solid-liquid separation, a poor solvent may be added to the slurry obtained by the precipitation step to further dilute, and the slurry may be stirred for the purpose of improving detergency.

  The poor solvent used in the washing step in the method for producing the polyphenylene ether powder of the present embodiment may be the same as the poor solvent used as the main component in the polymerization step, and more specifically, methanol is preferable.

  The mass ratio (b / a) between the poor solvent (b) used in the washing step and the polyphenylene ether (a) after the polymerization step used for washing is in the range of 1.0 to 5.0. Is more preferable, it is more preferable that it is 1.5-4.0, and it is further more preferable that it is the range of 2.0-3.0.

  When the poor solvent used in the washing step is a poor solvent having a low latent heat of vaporization, the poor solvent component can be volatilized within a short time in the dryer, which is preferable. Thereby, in order to volatilize the amine and solvent which have a higher boiling point, the time which stays in a dryer in the below-mentioned drying process can be used, and the below-mentioned drying process can be made efficient.

  The apparatus for solid-liquid separation in the washing process is not particularly limited, but a centrifugal separator (vibration type, screw type, decanter type, basket type, etc.), vacuum filter (drum type filter, belt filter, rotary) Vacuum filter, Young filter, Nutsche, etc.), filter press, and roll press can be used.

[[Drying process]]
Subsequently, in the method for producing polyphenylene ether of the present embodiment, the washed polyphenylene ether is dried. The drying treatment can be performed at a high temperature that does not cause the wet polyphenylene ether to fuse.

  As temperature of the drying process in a drying process, 60 degreeC or more is preferable at least, 80 degreeC or more is more preferable, 120 degreeC or more is further more preferable, and 140 degreeC or more is the most preferable. When the wet polyphenylene ether is dried at a temperature of 60 ° C. or higher, the content of high-boiling volatile components in the polyphenylene ether powder can be efficiently reduced.

  As the wet polyphenylene ether subjected to the drying treatment, those in which the contents of the high-boiling solvent and amine in the polyphenylene ether are reduced as much as possible by the above-described washing step are preferable. The smaller the content of the high boiling point solvent, the more the fusion of polyphenylene ether that can occur when the temperature is raised in the dryer.

  The amount of the alcohol solvent remaining in the polyphenylene ether after the drying treatment is 1.0 from the viewpoint of the work environment in the post-processing and the prevention of the reaction of substituting the hydroxyl group at the end of the polyphenylene ether with another functional group. The content is preferably less than mass%, more preferably 0.3 mass% or less, and still more preferably 0.1 mass% or less.

  In order to obtain polyphenylene ether with high efficiency, a method of increasing the drying temperature, a method of increasing the degree of vacuum in the drying atmosphere, a method of stirring during the drying, and the like are effective. In particular, the drying temperature is increased. The method is preferable from the viewpoint of production efficiency. In the drying step, it is preferable to use a dryer having a mixing function. Examples of the mixing function include a stirring type and a rolling type dryer. Thereby, the amount of processing can be increased and productivity can be maintained high.

  The production method of the polyphenylene ether of the present embodiment is not limited to the production method of the polyphenylene ether powder of the present embodiment described above, and the above-described polymerization step, copper extraction and by-product removal step, washing step, You may adjust suitably the order, frequency, etc. of a drying process.

Hereinafter, although this embodiment is described further in detail based on an Example, this embodiment is not limited to the following Examples.
First, the physical properties and measurement methods for evaluation and evaluation criteria will be described below.

(1) Measurement of weight average molecular weight (Mw) and weight average molecular weight (Mw) / number average molecular weight (Mn) As a measuring device, a gel permeation chromatography system 21 manufactured by Showa Denko Co., Ltd. was used and calibrated with standard polystyrene and ethylbenzene. A line was prepared, and using this calibration curve, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the obtained polyphenylene ether were measured.
As the standard polystyrene, those having a molecular weight of 3650000, 217000, 1090000, 681000, 204000, 52000, 30200, 13800, 3360, 1300, 550 were used.
As the column, a column in which two K-805L manufactured by Showa Denko KK were connected in series was used. As the solvent, chloroform was used, the flow rate of the solvent was 1.0 mL / min, and the column temperature was 40 ° C. As a measurement sample, a 1 g / L chloroform solution of polyphenylene ether was prepared and used. The UV wavelength of the detector was 254 nm for standard polystyrene and 283 nm for polyphenylene ether.

  Based on the above measurement data, the peak area based on the curve showing the molecular weight distribution obtained by GPC, the content of the high molecular weight component having a polystyrene equivalent molecular weight of 13,000 or more and the content of the low molecular weight component having a polystyrene equivalent molecular weight of less than 500 It was calculated from the ratio.

For the polyphenylene ether heated under the following heating conditions, the weight average molecular weight (Mw) was determined in the same manner as described above, and the difference in the weight average molecular weight (Mw) before and after heating was determined.
(Heating conditions) Heating temperature: 230 ° C., heating time: 10 minutes, heating pressure: 10 MPa
The smaller the difference in weight average molecular weight (Mw) before and after heating, the smaller the increase in molecular weight due to heat processing, which means improved workability and physical property prediction during heat processing.

(2) Quantification of residual nitrogen Using a nitrogen measuring device (TN-110 manufactured by Mitsubishi Analytech), the amount of residual nitrogen in the polyphenylene ether obtained in Examples and Comparative Examples was measured.
In addition, the sample used for the measurement was precisely weighed and used 10 mg of the polyphenylene ether of Examples and Comparative Examples pretreated under heating conditions of heating temperature: 230 ° C., heating time: 10 minutes, and heating pressure: 10 MPa. The heating temperature of the nitrogen measuring device was set to 800 ° C. for the INLET part and 900 ° C. for the CATALYST part.
The smaller the amount of residual nitrogen, the smaller the content of impurities (such as amine components) that cause odor during heat processing, and the higher the purity of polyphenylene ether.

(3) Quantification of the number of terminal groups represented by general formula (1) and general formula (2) contained in polyphenylene ether (3-1) Thermal desorption apparatus (TDU manufactured by Gestel) and GC / MS (Agilent) Volatile component identification by GC-7890B manufactured by GC, JEOL Co., Ltd. JMS-Q1050GC) About 10 mg of the polyphenylene ether obtained in Examples and Comparative Examples was placed in a sample tube packed with glass wool, and 280 ° C., 10 The mixture was heated for 5 minutes to decompose the terminal structure represented by the general formulas (1) and (2), and the generated volatile components were trapped at -100 ° C and concentrated. After the heating of the sample, the cooling trap and the concentrated volatile matter were rapidly heated to 300 ° C., desorbed as a gas component, and measured by GC / MS. The obtained chromatogram was analyzed to identify volatile components.
(3-2) Terminal structure analysis by ¹ H-NMR (500 MHz manufactured by JEOL) Polyphenylene ether obtained in Examples and Comparative Examples was dissolved in deuterated chloroform, and ¹ H-NMR measurement was performed using tetramethylsilane as an internal standard. Went. The peak in the obtained NMR spectrum of the terminal group structure represented by the general formula (1) and the general formula (2) to which the volatile components identified by the thermal desorption GC / MS described in (3-1) are bonded. And the end group structure was identified. The number of terminal groups represented by the general formula (1) and the general formula (2) per 100 units of the phenylene ether unit structure of the polyphenylene ether is expressed by a peak (6.2 based on the 3,5-position of the polyphenylene ether main chain aromatic ring. To 6.7 ppm), a peak derived from a methylene group substituted with an oxygen atom at the terminal of the polyphenylene ether represented by the general formula (1) (peaks of R ₄ and R ₅ ), a polyphenylene represented by the general formula (2) The peak was calculated from the methylene group substituted with a nitrogen atom at the ether end (peaks of R ₄ and R ₅ ) and the respective area ratios.
In addition, when the terminal structure represented by General Formula (1) and General Formula (2) is derived from 2,6-dimethylphenol as in Examples and Comparative Examples, R _{6 in} General Formula (1) is used. And a peak derived from a methylene group substituted with an oxygen atom at the terminal of the polyphenylene ether represented by the general formula (1) by R ₇ and R ₈ in the general formula (2) (peaks of R ₄ and R ₅ ), the general formula The peaks (R ₄ and R ₅ peaks) resulting from the methylene group substituted with the nitrogen atom at the end of the polyphenylene ether represented by (2) are as follows.
R ₆ = methyl group: peak of R ₄ and R ₅ = 4.55 ppm
R ₆ = ethyl group: peak of R ₄ and R ₅ = 4.80 ppm
R ₇ , R ₈ = n-butyl group: R ₄ , R ₅ peak = 3.62 ppm
R ₇ , R ₈ = n-octyl group: R ₄ , R ₅ peak = 3.62 ppm

(4) Measurement of glass transition temperature The glass transition temperature of polyphenylene ether was measured using a differential scanning calorimeter DSC (manufactured by PerkinElmer—Pyrisl). After heating from room temperature to 280 ° C. at a rate of 40 ° C. per minute in a nitrogen atmosphere, the temperature was lowered to 50 ° C. at 40 ° C. per minute, and then the glass transition temperature was measured at a rate of 40 ° C. per minute.
For the polyphenylene ether after heating, the glass transition temperature was determined in the same manner as described above, and the difference between the glass transition temperatures before and after heating was determined.

(5) Measurement of total volatile content of polyphenylene ether The total volatile content was calculated by subtracting the weight of polyphenylene ether dried under reduced pressure for 2 hours at 170 ° C. and 0.1 mmHg from the weight of polyphenylene ether before drying. Quantified. From the quantified weight of the total volatile content, the total volatile content (% by mass) was determined by the following formula.
Total volatile content (% by mass) =
(Weight of total volatile matter / weight of polyphenylene ether before drying) × 100
The smaller the total volatile content, the lower the content of impurities (solvent, amine, etc.) that cause odor during heat processing, and the higher the purity of polyphenylene ether.

(6) Measuring method of color tone (color index) of polyphenylene ether A 10 mL chloroform solution of 0.5 g of polyphenylene ether was prepared, and the solution was measured at 480 nm using an ultraviolet-visible absorptiometer (Hitachi, Ltd .: U-3210 type). Was measured (using an absorbance measurement cell having a cell length of 1 cm), and the photometric value was divided by the concentration (0.05 g / mL) to define the color index. It means that the smaller the color index value, the better the color tone of polyphenylene ether.

(7) Number of terminal hydroxyl groups of polyphenylene ether 5.0 mg of polyphenylene ether was weighed. Then, the weighed polyphenylene ether was dissolved in 25 mL of methylene chloride. After adding 150 μL of an ethanol solution of 2 mass% tetraethylammonium hydroxide (TEAH) to 2.0 mL of the adjusted solution, the absorbance at 318 nm (Hitachi Ltd .: U-3210 type) was used ( (Abs) was measured (using an absorbance measurement cell having a cell length of 1 cm). And based on the measurement result, the pseudo molecular weight obtained from the absorbance was obtained by the following formula. Moreover, the number of terminal hydroxyl groups per molecule of polyphenylene ether was calculated using the number average molecular weight determined using the gel permeation chromatography described in (1) above.
Pseudomolecular weight obtained from absorbance (g / mol) = [((ε × 5) / (25 × Abs)]
Here, ε represents an extinction coefficient and is 4700 L / mol · cm.
Number of terminal hydroxyl groups per molecule of polyphenylene ether (number / molecule) =
(Number average molecular weight determined using gel permeation chromatography) / (Pseudo molecular weight obtained from absorbance)

(8) Average particle size of polyphenylene ether Polyphenylene obtained by a wet method (methanol solvent) using a laser diffraction scattering type particle size distribution analyzer manufactured by Shimadzu Corporation, which is a particle size distribution meter of laser diffraction scattering method The volume average particle diameter of the ether powder was measured. From the cumulative curve of the particle size distribution of the volume average particle size, the particle size (median diameter) corresponding to the median cumulative value was defined as the average particle size (μm).
In addition, the polyphenylene ether of Comparative Examples 4 to 6 is obtained as a lump because the toluene solvent is distilled off from the polyphenylene ether polymerization solution using an evaporator, and cannot be measured by the above average particle size measurement method. Therefore, it was not measured.

(9) Solubility Evaluation in Methyl Ethyl Ketone Using the polyphenylene ether obtained in Examples 1 to 7 and Comparative Examples 1 to 7, solubility in methyl ethyl ketone was evaluated. The test method was performed as follows. First, 100 g of methyl ethyl ketone was put into a round bottom flask and gently stirred at 20 ° C. using a magnetic stirrer. Here, 20 g of the polyphenylene ether of each example was added at once. The mixture becomes cloudy at first, but eventually becomes clear. The time (dissolution time) required until it became clear after adding all at once was measured. Moreover, the inside of the flask at the time of dissolution was observed.
The dissolution times of Examples 1 to 7 and Comparative Examples 1 to 3 and 7 were both about 1 minute, and no adhesion to the inner wall of the flask was observed. The dissolution time of Comparative Examples 4 to 6 was 20 minutes, and a granular lump of polyphenylene ether was formed and adhered to the inner wall of the flask, which did not readily dissolve.
The adhesion to the inner wall of the flask is not observed, and the shorter the dissolution time, the better the solubility.

(10) Evaluation of dispersion stability in high-viscosity liquid With respect to the polyphenylene ethers obtained in Examples 1 to 7 and Comparative Examples 1 to 7, dispersion stability to paraffinic oil (Diana Process Oil PW380, manufactured by Idemitsu Kosan Co., Ltd.) Sex was evaluated. The test method was performed as follows. First, 10 g of paraffinic oil was placed in a 50 mL sample tube with a lid, and 3 g of polyphenylene ether of each example was added thereto. The polyphenylene ether was shaken well so as to be dispersed throughout the paraffinic oil, and dispersed uniformly. Thereafter, the mixture was allowed to stand for one day, and the dispersion state of polyphenylene ether in paraffinic oil was observed.
The results were evaluated according to the following criteria.
◯: Means that the state of being dispersed throughout the paraffinic oil is maintained and that the dispersion stability in a high viscosity liquid is excellent.
X: It means that the dispersion state in the whole paraffinic oil is not maintained, and the dispersion stability in the high viscosity liquid is insufficient.

(11) Odor at the time of heat processing About the polyphenylene ether obtained in Examples 1 to 7 and Comparative Examples 1 to 7, a compression molding machine (Shinto Metal Industry Co., Ltd.) using a 10 cm long and 20 cm wide mold. Was subjected to heat press treatment under the following conditions, and sensory evaluation of odor during work was performed. Not feeling odors such as solvents and amines means improved workability during heat processing.
(Heating conditions) Heating temperature: 230 ° C., heating time: 10 minutes, heating pressure: 10 MPa
The results were evaluated according to the following criteria.
○: No odor of solvent or amine.
X: A odor such as solvent or amine is felt.

  Hereafter, the polyphenylene ether manufacturing method of each Example and a comparative example is demonstrated.

(Example 1)
To a reactor with a jacket of 1.5 liters equipped with a sparger for introducing an oxygen-containing gas at the bottom of the reactor, a stirring turbine blade and baffle, and a reflux condenser in the vent gas line at the top of the reactor, 0.2512 g of chloride Dicopper dihydrate, 1.1062 g of 35% hydrochloric acid, 9.5937 g of N, N, N ′, N′-tetramethylpropanediamine, 71.0 g of n-butanol and 638.0 g of methanol, 180. 0 g of 2,6-dimethylphenol (referred to as “2,6-xylenol” in the table) was added. The composition weight ratio of the solvent used was n-butanol: methanol = 10: 90. Then, while vigorously stirring, oxygen was started to be introduced from the sparger at a rate of 180 mL / min, and at the same time, the polymerization temperature was adjusted by passing a heating medium through the jacket so as to maintain 45 ° C. The polymerization solution gradually became a slurry.
120 minutes after starting to introduce oxygen, stop the oxygen-containing gas from flowing, and add 50% aqueous solution in which 1.30 g of ethylenediaminetetraacetic acid tripotassium salt (a reagent manufactured by Dojindo Laboratories) was dissolved in this polymerization mixture, Next, 1.62 g of hydroquinone (manufactured by Wako Pure Chemical Industries, Ltd.) was added little by little, and the mixture was reacted at 45 ° C. for 1 hour until the slurry polyphenylene ether became white. After completion of the reaction, the mixture is filtered, washed three times with an amount of the cleaning liquid (b) in which the mass ratio (b / a) of the methanol cleaning liquid (b) to the polyphenylene ether (a) to be cleaned is 4, and wet polyphenylene Ether was obtained. Then, it was vacuum-dried at 120 ° C. for 1 hour to obtain dry polyphenylene ether. The analysis results of the obtained polyphenylene ether are shown in Table 1.

(Example 2)
Except that the solvent used was 213.0 g n-butanol and 496.0 g methanol, and the composition weight ratio of the solvent used was n-butanol: methanol = 30: 70, the same method as in Example 1 was used. Polyphenylene ether was obtained. The analysis results of the obtained polyphenylene ether are shown in Table 1.

(Example 3)
Except that the solvent used was 352.0 g n-butanol and 352.0 g methanol, and the composition weight ratio of the solvent used was n-butanol: methanol = 50: 50, it was the same as the method of Example 1. Polyphenylene ether was obtained. The analysis results of the obtained polyphenylene ether are shown in Table 1.

Example 4
The phenolic compounds used were 151.7 g of 2,6-dimethylphenol and 28.25 g of 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane (denoted as “bisphenol” in the table). Except for the above, polyphenylene ether was obtained in the same manner as in Example 2. The analysis results of the obtained polyphenylene ether are shown in Table 1.

(Example 5)
The procedure of Example 2 was followed except that the phenolic compound used was 122.8 g 2,6-dimethylphenol and 57.17 g 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane. In the same manner, polyphenylene ether was obtained. The analysis results of the obtained polyphenylene ether are shown in Table 1.

(Example 6)
The procedure of Example 2 was followed except that the amine used was 1.5 g dibutylamine (denoted as “DBA” in the table) and 9.59 g N, N, N ′, N′-tetramethylpropanediamine. In the same manner, polyphenylene ether was obtained. The analysis results of the obtained polyphenylene ether are shown in Table 1.

(Example 7)
A polyphenylene ether was obtained in the same manner as in Example 2, except that 0.2 g of dibutylamine and 9.59 g of N, N, N ′, N′-tetramethylpropanediamine were used. The analysis results of the obtained polyphenylene ether are shown in Table 1.

(Comparative Example 1)
A polyphenylene ether was obtained in the same manner as in Example 2, except that the amine used was 5.71 g dibutylamine and 9.59 g N, N, N ′, N′-tetramethylpropanediamine. The analysis results of the obtained polyphenylene ether are shown in Table 1.

(Comparative Example 2)
A polyphenylene ether was obtained in the same manner as in Example 3 except that 5.71 g of dibutylamine and 9.59 g of N, N, N ′, N′-tetramethylpropanediamine were used. The analysis results of the obtained polyphenylene ether are shown in Table 1.

(Comparative Example 3)
A polyphenylene ether was obtained in the same manner as in Example 5, except that 4.68 g of dibutylamine and 7.85 g of N, N, N ′, N′-tetramethylpropanediamine were used. The analysis results of the obtained polyphenylene ether are shown in Table 1.

(Comparative Example 4)
2.51 g of pre-conditioned oxidation in a 45 liter jacketed reactor equipped with a sparger for introduction of oxygen-containing gas at the bottom of the reactor, a stirring turbine blade and baffle, and a reflux condenser in the vent gas line at the top of the reactor. Mixture of cuprous and 18.96 g 47% hydrogen bromide with 29.39 g di-n-butylamine, 6.05 g N, N′-di-t-butylethylenediamine, 84.0 g dimethyl-n -Butylamine, 12909 g of toluene, 1950 g of 2,6-dimethylphenol were charged. Then, while vigorously stirring, air was introduced into the reactor at a rate of 20.5 NL / min (10.5 NL per 1.0 kg of 2,6-dimethylphenol) and at the same time the polymerization temperature was 40 ° C. The jacket was adjusted to pass through a heating medium. 65 minutes after starting to introduce the air, the air flow was stopped, and 31.8 g of ethylenediaminetetraacetic acid tetrasodium salt tetrahydrate (a reagent manufactured by Dojindo Laboratories) was added to the polymerization solution as a 1500 g aqueous solution. Warmed to 70 ° C. After keeping the temperature at 70 ° C. for 2 hours and removing the diphenoquinone produced as a by-product from the catalyst, the mixture was transferred to a centrifuge manufactured by Sharpless Co., and the polyphenylene ether solution (organic phase) and the aqueous solution into which the catalyst metal was transferred. Separated into phases. The obtained polyphenylene ether solution was transferred to a jacketed concentration tank, and toluene was distilled off and concentrated until the solid content in the polyphenylene ether solution became 55% by mass. Subsequently, toluene was further distilled off using an oil bath and a rotary evaporator set at 230 ° C., and the solid content was dried to obtain polyphenylene ether. The analysis results of the obtained polyphenylene ether are shown in Table 1.
In the process of removing toluene by heating, it was confirmed by ¹ H-NMR that the amine bonded to the terminal of polyphenylene ether was eliminated.

(Comparative Example 5)
The catalyst is a mixture of 2.51 g cuprous oxide, 18.96 g 47% hydrogen bromide, 35.5 g N, N′-di-t-butylethylenediamine, 84.0 g dimethyl-n-butylamine and Except that, polyphenylene ether was obtained in the same manner as in Comparative Example 4. The analysis results of the obtained polyphenylene ether are shown in Table 1.
In the process of removing toluene by heating, it was confirmed by ¹ H-NMR that the amine bonded to the terminal of polyphenylene ether was eliminated.

(Comparative Example 6)
The same procedure as in Comparative Example 4 was conducted, except that the phenolic compound used was 1,326 g of 2,6-dimethylphenol and 624 g of 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane. Thus, polyphenylene ether was obtained. The analysis results of the obtained polyphenylene ether are shown in Table 1.
In the process of removing toluene by heating, it was confirmed by ¹ H-NMR that the amine bonded to the terminal of polyphenylene ether was eliminated.

(Comparative Example 7)
A polyphenylene ether was obtained in the same manner as in Example 2 except that the time from the start of introduction of oxygen to the stop was 600 minutes. The analysis results of the obtained polyphenylene ether are shown in Table 1.

  As shown in Table 1, in Examples 1 to 7, it was possible to obtain a highly pure polyphenylene ether with few residual volatile components while efficiently suppressing a change in weight molecular weight before and after heating. In Examples 4 and 5 in which 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane was copolymerized, the number of terminal hydroxyl groups per molecule of polyphenylene ether was close to 2.0. It was confirmed that the molecular chain of the obtained polyphenylene ether contained a structural unit derived from the dihydric phenol compound represented by the general formula (3).

  As shown in Table 1, in Comparative Examples 1, 2, and 3, the ratio of the number of units having a leaving group (amino group) of the general formula (2) at the end of polyphenylene ether compared to Examples 1 to 7, respectively. Since it is high, the change in molecular weight before and after heating is large, and the change in glass transition temperature is also large. Moreover, since the amine chemically bonded to the polyphenylene ether terminal is removed by the heat treatment, the amine is liberated after the heat treatment, leading to odor and a decrease in purity. In Comparative Example 7, since the ratio of the number of units having the leaving group (methoxy group) of the general formula (1) at the polyphenylene ether terminal is high, the change in molecular weight before and after heating is large, and the change in glass transition temperature is also large.

  In particular, compared with Comparative Example 1, in Comparative Example 2, the ratio of the molecular weight of 13,000 or more of the polyphenylene ether product is larger than 8% by mass, so the change in molecular weight after heat treatment is larger. This is thought to be due to the reaction between the high molecular weight molecules and an increase in the molecular weight. In Comparative Example 3, since 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane is copolymerized, the number of terminals of polyphenylene ether increases, and the amino group of the general formula (2) is bonded. Many terminal ends are included. For this reason, compared with the comparative example 1 which used only 2, 6- dimethylphenol, a molecular weight change becomes larger.

  Since Comparative Examples 4, 5, and 6 are direct desorption methods, all of the bonded amines are eliminated in the polyphenylene ether isolation step, and even when the obtained polyphenylene ether is heat-treated, the change in molecular weight is small. However, in the direct removal method, an aromatic solvent which is a good solvent for polyphenylene ether and has high affinity with polyphenylene ether and is difficult to remove remains, which causes odor during heat processing. C. I. In the isolation process by heat treatment, oxidative degradation has also progressed, and the purity is low.

  Since the polyphenylene ether of the present invention has few residual volatile components, high purity, and easy control of physical properties before and after heat treatment, it can be used as a composite material or modifier for obtaining excellent characteristics in combination with other resins. There is industrial use value.

Claims (10)

The weight average molecular weight (Mw) is 2500-6000,
The ratio of the weight average molecular weight to the number average molecular weight (Mn) (Mw / Mn) is 1.0 to 2.0,
The total number of terminal groups represented by the following general formula (1) and general formula (2) is 0.8 or less per 100 phenylene ether units constituting the resin.
A polyphenylene ether characterized by that.

(In Formula (1), R < ₁ > -R < ₃ > is each independently selected from the group which consists of a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen group, an aryl group, and a substituted aryl group, R < ₄ >, R < ₅ > , Is hydrogen, and R ₆ is selected from the group consisting of alkyl groups, substituted alkyl groups, alkenyl groups, substituted alkenyl groups, aryl groups, and substituted aryl groups.)

(In the formula (2), R _{1 to} R ₅ are the same as those defined for the general formula (1), and R ₇ and R ₈ are each independently a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl Selected from the group consisting of a group and a substituted aryl group, but not simultaneously hydrogen.)   2. The polyphenylene ether according to claim 1, wherein the total number of terminal groups represented by the general formula (1) and the general formula (2) is 0.01 or more per 100 phenylene ether units constituting the resin. . The polyphenylene ether according to claim 1 or 2, wherein the difference in weight average molecular weight measured before and after heating under the following heating conditions is 1000 or less.
(Heating conditions) Heating temperature: 230 ° C., heating time: 10 minutes, heating pressure: 10 MPa   The content of a high molecular weight component having a molecular weight of 13,000 or more is 8.0% by mass or less, and the content of a low molecular weight component having a molecular weight of less than 500 is 3.0% by mass or less. The polyphenylene ether described in 1.   The polyphenylene ether according to any one of claims 1 to 4, which has substantially no end group represented by the general formula (2). The polyphenylene ether in any one of Claims 1-5 which has a structural unit derived from the bihydric phenol compound represented by General formula (3) in a molecular chain.

(In Formula (3), R < ₉ >, R < ₁₀ >, R <_11> , and R <_12> are respectively independently a hydrogen atom, a halogen atom, a C1-C7 alkyl group, a phenyl group, a haloalkyl group, an aminoalkyl group. , A hydrocarbonoxy group, and a halohydrocarbonoxy group, wherein at least two carbon atoms separate the halogen atom and the oxygen atom, and X is a single bond, a divalent heteroatom, and (Selected from the group consisting of divalent hydrocarbon groups having 1 to 12 carbon atoms.)   The polyphenylene ether according to claim 1, wherein the amount of residual nitrogen is 300 mass ppm or less.   The polyphenylene ether according to any one of claims 1 to 7, wherein the color index (C.I) value is 1.0 or less.   The polyphenylene ether according to any one of claims 1 to 8, wherein the total volatile content is less than 0.5% by mass. In the polymerization process of polyphenylene ether,
As the polymerization solvent, at least one kind of alcohol solvent having 1 to 10 carbon atoms is used,
The method for producing a polyphenylene ether according to any one of claims 1 to 9, wherein an amine compound substantially free of a primary amine and a secondary monoamine is used as a polymerization catalyst.