JP5588297B2 - Polyphenylene ether - Google Patents

Description

  The present invention relates to polyphenylene ether.

  Polyphenylene ether is excellent in processability and productivity, and has an advantage that a product or part having a desired shape can be efficiently produced by a molding method such as melt injection molding or melt extrusion molding. Taking advantage of such advantages, polyphenylene ether is widely used as a material for parts in the fields of electric and electronic materials and automobiles, and as a material for parts in the fields of various other industrial materials and food packaging.

  In recent years, as a new industrial use of polyphenylene ether, use as a composite material for obtaining excellent characteristics in combination with other resins, use as an electronic material, and the like have been studied. For these applications, low molecular weight polyphenylene ether is considered to be effective in addition to conventionally known polyphenylene ether. In addition, there is a high demand for polyphenylene ether having a small amount of change in color tone before and after heating. However, it is known that polyphenylene ether turns brown when heated, and the color becomes more pronounced as the molecular weight becomes lower. At present, sufficient improvement has not been made with respect to such changes in color tone before and after heating of polyphenylene ether, for example, the colorability of polyphenylene ether during melt processing. In addition, a large change in color tone before and after heating means that the degree of dependence on various processing conditions and processing temperatures increases. In today's diversified uses of polyphenylene ether, there is a strong demand for polyphenylene ether that has little color change before and after heating.

  As a method for obtaining polyphenylene ether with little change in color tone before and after heating, for example, a method for inactivating the molecular structure of the polyphenylene ether polymer itself has been proposed. As specific examples, Patent Document 1 includes a method using terminal acylation, Patent Document 2 includes a method using terminal amidation, Patent Document 3 includes a method using terminal styrenation, and Patent Document 4 includes a low molecular weight styrene polymer. A method of combining is disclosed. Further, a plurality of techniques for adding amines to polyphenylene ether have been proposed. For example, Patent Document 5, Patent Document 6 and Patent Document 7 disclose methods of adding aromatic amines to polyphenylene ether. According to these methods, there is an effect in improving the colorability due to the thermal history not higher than the glass transition temperature of the polyphenylene ether polymer, that is, not higher than about 150 ° C.

  Patent Document 8 discloses a PPE composition obtained by press-molding at 250 ° C. with a polyamine ether powder containing monoamine for the purpose of improving light stability. Patent Document 9 discloses a polyphenylene ether composition obtained by press-molding polyphenylene ether modified with benzylamine at 280 ° C. in the presence of benzylamine, and a PPE composition in which coloring during heating is suppressed. Is obtained.

  In Patent Document 10, a secondary or tertiary aliphatic monoamine having an acidity (Pka) of 8 or more and a boiling point of 80 ° C. or more is mixed with 5 parts by weight with respect to 100 parts by weight of polyphenylene ether, and heated. A polyphenylene ether composition in which deterioration of color tone is suppressed is disclosed.

U.S. Pat. No. 3,375,228 Japanese Patent Publication No.46-2837 Japanese Examined Patent Publication No. 46-32427 JP-A-1-172451 JP 52-84247 A JP 58-176243 A JP 58-176245 A JP-A-6-145497 JP 7-278292 A JP-A-6-157893

  However, in the methods of Patent Documents 1 to 4, the effect of improving the colorability upon heating is not sufficient, and the polyphenylene ether obtained by the methods disclosed in Patent Documents 5 to 8 and 10 is an amine added during processing. Remains, thus lowering the purity of the polyphenylene ether. In addition, some of the amines listed in the examples correspond to hazardous materials, and are processed at temperatures above the flash point of the amine used, and further the ignition point of the amine used, for safe industrial production. Equipment is required. In addition, since amines have a unique odor and there is a concern about deterioration of the working environment, the methods disclosed in Patent Documents 5 to 8 and 10 are undesirable methods for obtaining highly pure polyphenylene ether. Furthermore, in the method disclosed in Patent Document 9, only the colorability at a low temperature such as 250 ° C. has been studied, and the processing temperature (300 ° C.) of a general polyphenylene ether ether is not high. The coloring property has not been studied.

  Therefore, in view of the above-described problems of the prior art, an object of the present invention is to provide a polyphenylene ether that suppresses a change in color tone when heated at a high temperature, has excellent toning properties, and has a higher purity.

  As a result of diligent research on the above-described problems of the prior art, the inventors have added a specific monoamine after the start of polymerization in the production of polyphenylene ether, so that the purity is high and the color tone changes before and after heating. The inventors have determined that less polyphenylene ether can be obtained and have completed the present invention.

  That is, the present invention is as follows.

[1]
[Delta] C. I. A polyphenylene ether in which is from 0 to 7;
ΔC. I. = (C. I. heat-C. I. ppe) / C. I. ppe
C. I. ppe: Color index value of polyphenylene ether before heating I. heat: Color index value of polyphenylene ether after heating (heating conditions of polyphenylene ether)
Heating temperature: 310 ° C., heating time: 20 minutes, heating pressure: 10 MPa.

[2]
The polyphenylene ether according to [1], wherein the number of phenolic hydroxyl groups is 0.6 or more per 100 units of the polyphenylene ether unit structure.

[3]
C. I. The polyphenylene ether according to [1] or [2], wherein ppe is 0.8 or less.

[4]
C. I. The polyphenylene ether according to any one of [1] to [3], wherein the heat is 4.0 or less.

[5]
The component according to any one of [1] to [4], comprising a component having a molecular weight of 50,000 or more in an amount of 5 to 20% by mass and a component having a molecular weight of 8,000 or less in an amount of 12 to 30% by mass. Polyphenylene ether.

[6]
The polyphenylene ether according to any one of [1] to [5], wherein the residual nitrogen amount is 2000 ppm or less.

  According to the present invention, it is possible to obtain a polyphenylene ether with little color tone change during heat processing.

  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 is not intended to limit the present invention only to this embodiment. And this invention can be deform | transformed suitably and implemented within the range of the summary.

  The polyphenylene ether according to the present embodiment (hereinafter sometimes simply referred to as “PPE”) is a homopolymer and / or copolymer having a repeating unit structure represented by the following formula (1).

式（１）中、Ｒ₁、Ｒ₂、Ｒ₃、及びＲ₄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、炭化水素オキシ基又は少なくとも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から選択される。

In the formula (1), R ₁ , R ₂ , R ₃ , and R ₄ 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, It is selected from the group consisting of a hydrocarbonoxy group or a halohydrocarbonoxy group in which at least two carbon atoms separate a halogen atom and an oxygen atom.

In the formula (1), examples of the halogen atom represented by R ₁ , R ₂ , R ₃ and R ₄ include a fluorine atom, a chlorine atom and a bromine atom, and a chlorine atom and a bromine atom are preferable.

In the formula (1), the “alkyl group” represented by R ₁ , R ₂ , R ₃ , and R ₄ is linear or branched having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms. It represents a chain alkyl group, and examples thereof include 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 (1), the alkyl group represented by R ₁ , R ₂ , R ₃ , and R ₄ 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), an alkyl group having 1 to 6 carbon atoms (for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl), aryl groups (eg, phenyl, naphthyl), alkenyl groups (eg, ethenyl, 1-propenyl, 2-propenyl), alkynyl groups (eg, ethynyl, 1-propynyl, 2-propynyl) , Aralkyl groups (for example, benzyl, phenethyl), alkoxy groups (for example, methoxy, ethoxy) and the like.

  A color index (CI) can be used as an index of the colorability of polyphenylene ether.

  Polyphenylene ether is often used by being melt-kneaded with other resins, and is known to be colored by heating. Therefore, the smaller the color index value of the polyphenylene ether before heating and the color index value of the polyphenylene ether after heating, and the smaller the rate of change of the color index value before and after heating, the better the polyphenylene ether. Examples of the “polyphenylene ether after heating” include polyphenylene ether after melt-kneading, polyphenylene ether after molding, polyphenylene ether after compression, and the like. As an example of a typical method for measuring the color index value of polyphenylene ether after heating, the color index value (CI heat) of polyphenylene ether obtained by compressing polyphenylene ether at 310 ° C. for 20 minutes at a pressure of 10 MPa is used. ) Is easy to measure.

  The polyphenylene ether of the present embodiment has a ΔC. I. Is 0 or more and 7 or less.

ΔC. I. = (C. I. heat-C. I. ppe) / C. I. ppe
C. I. ppe: Color index value of polyphenylene ether before heating I. heat: Color index value of polyphenylene ether after heating (heating conditions of polyphenylene ether)
Heating temperature: 310 ° C., heating time: 20 minutes, heating pressure: 10 MPa.

  ΔC. I. The smaller the value, the smaller the change rate, and the better the color tone of polyphenylene ether. The ΔC. I. Is preferably 0 or more and 6.0 or less, and more preferably 0 or more and 5.0 or less.

  ΔC. I. The polyphenylene ether having a value within the above range can be obtained, for example, by adding a monoamine described later after the start of polymerization.

  In the present embodiment, the color index (CI) of polyphenylene ether is obtained as follows.

  Polyphenylene ether is dissolved in chloroform to obtain a chloroform solution having a polyphenylene ether concentration of 0.05 g / mL.

  Into a quartz cell having a cell length of 1 cm, the same chloroform as that used for dissolving polyphenylene ether is put, and the absorbance of pure chloroform is measured with ultraviolet light (wavelength 480 nm) to make the absorbance zero.

  The chloroform solution of the polyphenylene ether prepared above is put in the same cell, and the absorbance at 480 nm is measured.

  The value obtained by subtracting the absorbance of pure chloroform from the absorbance of polyphenylene ether in chloroform and dividing by the polyphenylene ether concentration in the chloroform solution of polyphenylene ether is defined as the color index (CI) of polyphenylene ether.

  The larger the color index value, the more colored it is.

  The color index value (CI.ppe) of the polyphenylene ether before heating is preferably as small as possible from the viewpoint of toning properties, specifically 0.8 or less, more preferably 0.6 or less. More preferably, it is 0.5 or less.

  The color index value (CI.heat) after heating is preferably as small as possible from the viewpoint of toning properties, specifically 4.0 or less, more preferably 3.5 or less, even more preferably. Is 3.0, most preferably 2.5 or less.

  The polyphenylene ether of the present embodiment is preferably a polyphenylene ether having a low molecular weight and a small oligomer component. Further, the polyphenylene ether according to the present embodiment includes a component having a molecular weight of 50,000 or more in an amount of 5 to 20% by mass and a component having a molecular weight of 8,000 or less in an amount of 12 to 30% by mass. Is preferred. By controlling the amount of the component having a molecular weight of 8,000 or less and the component amount of 50,000 or more to a specific range, the formation of the eyes and the gel during heat processing is improved, and the resulting polyphenylene ether has high mechanical strength. Tend to have. That is, from the viewpoint of suppressing generation of eyes and gels, it is preferable to contain a component having a molecular weight of 50,000 or more in an amount of 5 to 20% by mass, and in an amount of 5 to 18% by mass with respect to the whole polyphenylene ether. Is more preferable. From the viewpoint of mechanical properties, it is preferable that a component having a molecular weight of 8,000 or less is contained in an amount of 12 to 30% by mass, and more preferably 15 to 30% by mass with respect to the whole polyphenylene ether.

  In the method for producing polyphenylene ether of the present embodiment, for example, by controlling the polymerization time, the amount of catalyst used, the amount of monomer, the solvent composition, etc., the component having a molecular weight of 50,000 or more is controlled to the above specific amount, and The component having a molecular weight of 8,000 or less can be controlled to the above-mentioned specific amount.

  After the polyphenylene ether is produced, for example, if the polyphenylene ether having a molecular weight of 8,000 or less exceeds 30% by mass or less than 12% by mass, or the polyphenylene ether having a molecular weight of 50,000 or more exceeds 20% by mass Alternatively, in the case of less than 5% by mass, the molecular weight can be adjusted by the following method.

  For example, a method of dissolving polyphenylene ether in a good solvent and reprecipitating it with a poor solvent and isolating it, or washing with a mixed solvent of a good solvent and a poor solvent can be applied.

  Since these methods can adjust the molecular weight depending on the treatment temperature, they can be used as a method for adjusting the molecular weight of polyphenylene ether. However, there is a high possibility that the reduced unnecessary components cause polymer loss and the yield decreases. Therefore, the method of producing the polyphenylene ether of the present embodiment in the polymerization stage without using the molecular weight adjusting method is preferable from the viewpoint of producing the polyphenylene ether efficiently.

  Conventionally, the polyphenylene ether generally used has a molecular weight of about 50,000 or more of a normal molecular weight type and is about 40% by mass, and a low molecular weight type is about 25% by mass. On the other hand, the amount of components having a molecular weight of 8,000 or less is usually about 3 to 10% by mass for the molecular weight type and the low molecular weight type. The polyphenylene ether of the present embodiment is preferably a low molecular weight type polyphenylene ether different from these polyphenylene ethers.

  In particular, when polyphenylene ether having a component of a predetermined molecular weight and polyphenylene ether having a component of a predetermined molecular weight coexist and having a narrow molecular weight distribution, monoamine is added after the start of polymerization. In addition, by controlling the monoamine concentration, it is possible to produce a polyphenylene ether exhibiting a very good color tone, and in particular, producing a polyphenylene ether that is extremely low in color tone before and after heating and excellent in toning properties. it can.

  In addition, the information regarding the molecular weight of the polyphenylene ether of this Embodiment is obtained by the measurement using a gel permeation chromatography measuring apparatus. As specific measurement conditions of gel permeation chromatography, Showa Denko Co., Ltd. Gel Permeation Chromatography System 21 (Column: Showa Denko K-805L in series, column temperature: 40 ° C., solvent : Chloroform, solvent flow rate: 1.0 ml / min, sample concentration: 1 g / L chloroform solution of polyphenylene ether), standard polystyrene (the molecular weight of standard polystyrene is 3,650,000, 2,170,000, 1 , 090,000, 681,000, 204,000, 52,000, 30,200, 13,800, 3,360, 1,300, 550).

  The UV wavelength of the detector can be selected from 254 nm for standard polystyrene and 283 nm for polyphenylene ether.

  The number average molecular weight (Mn) of the polyphenylene ether of the present embodiment is preferably 7,000 or more and 15,000 or less from the viewpoint of suppressing the generation of eyes and gels during heat processing and high mechanical strength. A more preferable lower limit is 8,000 or more, and a further preferable lower limit is 9,000 or more. Moreover, a more preferable upper limit is 14,000 or less, and a more preferable upper limit is 13,000 or less. From the viewpoint of exhibiting mechanical properties, the lower limit of the number average molecular weight is preferably 7,000 or more. From the viewpoint of suppressing the occurrence of gel and gel during heat processing, the upper limit of the number average molecular weight is 15,000 or less. Preferably there is.

  Further, as an index indicating the molecular weight distribution, the degree of dispersion represented by weight average molecular weight (Mw) / number average molecular weight (Mn) is used. The degree of dispersion indicates that the smaller the value is, the narrower the molecular weight distribution is, and 1 is the minimum value.

  The degree of dispersion of the polyphenylene ether in the present embodiment is preferably 3.0 or less. When the dispersity is within this range, it tends to be a polyphenylene ether excellent in solubility in a solvent. The degree of dispersion is more preferably 2.8 or less, still more preferably 2.6 or less, and most preferably 2.5 or less.

  The dispersity is preferably 1.6 or more. If it is less than this range, there is a high possibility that it will be difficult to make the amount of a component having a molecular weight of 8,000 or less and the amount of a component having a molecular weight of 50,000 or more into a specific range, and thus a suitable polyphenylene ether can be produced efficiently. It becomes difficult. The degree of dispersion is more preferably 1.8 or more, further preferably 1.9 or more, and most preferably 2.0 or more.

  The residual nitrogen amount can be used as an indicator of the purity of the polyphenylene ether. 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 by a nitrogen measuring device, and specifically can be determined by the method described in the examples described later.

  The amount of residual nitrogen is preferably 2000 ppm or less in the polyphenylene ether, more preferably 1500 ppm or less, still more preferably 1000 ppm or less, and still more preferably 800 ppm because it causes odor during heat processing. Or less, most preferably 700 ppm or less.

  The number of phenolic hydroxyl groups at the molecular chain end of the polyphenylene ether is calculated by NMR and can be calculated as the number of phenolic hydroxyl groups per 100 units of the polyphenylene ether unit structure. As an example, polyphenylene ether is dissolved in deuterated chloroform, tetramethylsilane is used as an internal standard, and H-NMR (500 MHz manufactured by JEOL) is measured. 36 ppm)), the peak due to the polyphenylene ether main chain aromatic ring 3, 5 position (6.3 to 6.7 ppm), and the area ratio of each peak.

  Since the phenolic hydroxyl group can be a reactive site with other resins, the number is preferably 0.6 or more per 100 units of polyphenylene ether unit structure, more preferably 0.7 or more, and still more preferably 0.8. 8 or more, and most preferably 0.9 or more.

  In general, if the number of phenolic hydroxyl groups at the end of the molecular chain is large, the color index value (CI.heat) before and after heating increases, and the color tone tends to deteriorate. It is difficult to maintain. However, surprisingly, since the polyphenylene ether according to the present embodiment is obtained by adding monoamine after the start of polymerization as described above, even if the number of phenolic hydroxyl groups is in the above range, it is extremely good after heating. It is a highly pure polyphenylene ether that exhibits a good color tone and has few remaining amine components and catalyst components.

  The polyphenylene ether represented by the above formula (1) can be produced by polymerizing the following phenol compounds.

  Examples of the phenol compound include o-cresol, 2,6-dimethylphenol, 2-ethylphenol, 2-methyl-6-ethylphenol, 2,6-diethylphenol, 2-n-propylphenol, and 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-phenylphenol, 2-phenylphenol, 2,6 -Diphenylphenol, 2,6-bis- (4-fluorophenyl) phenol, 2-methyl -6-tolylphenol, 2,6-ditolylphenol, 2,5-dimethylphenol, 2,3,6-trimethylphenol, 2,5-diethylphenol, 2-methyl-5-ethylphenol, 2-ethyl- 5-methylphenol, 2-allyl-5-methylphenol, 2,5-diallylphenol, 2,3-diethyl-6-n-propylphenol, 2-methyl-5-chlorophenol, 2-methyl-5-bromo Phenol, 2-methyl-5-isopropylphenol, 2-methyl-5-n-propylphenol, 2-ethyl-5-bromophenol, 2-methyl-5-n-butylphenol, 2,5-di-n-propyl Phenol, 2-ethyl-5-chlorophenol, 2-methyl-5-phenylphenol, 2,5-diphenylphenol Diol, 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- Examples include n-butylphenol and 2,6-dimethyl-3-t-butylphenol.

  In particular, 2,6-dimethylphenol, 2,6-diethylphenol, 2,6-diphenylphenol, 2,3,6-trimethylphenol, and 2,5-dimethylphenol are preferable because they are inexpensive and easily available. 2,6-dimethylphenol and 2,3,6-trimethylphenol are more preferable.

  The said phenol compound may be used independently 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-trimethylphenol And a method using a combination of 2,5-dimethylphenol and a method using a combination of 2,6-dimethylphenol and 2,3,6-trimethylphenol. The mixing ratio can be arbitrarily selected. In addition, the phenolic compounds used contain a small amount of m-cresol, p-cresol, 2,4-dimethylphenol, 2,4,6-trimethylphenol, etc., which are contained as by-products during production. May be.

  In addition to the phenol compound, a divalent phenol compound represented by the following formula (2) may be contained in the compound to be used. The divalent phenol compound represented by the following formula (2) is a reaction between a corresponding monovalent phenol compound and a ketone or a dihalogenated aliphatic hydrocarbon, or between corresponding monovalent phenol compounds. It can be advantageously produced industrially by the above reaction. For example, there are compound groups obtained by reaction of general-purpose ketone compounds such as formaldehyde, acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, cyclohexane and monovalent phenol compounds, and compound groups obtained by reaction of monovalent phenol compounds. . Examples of such a compound include compounds represented by the following general formulas (2-a), (2-b), and (2-c).

上記式で表される代表的な化合物が、Ｒ₅及びＲ₆がメチル基、Ｒ₇及びＲ₈が水素でＸが両方のアリール基を直結している化合物、Ｒ₅及びＲ₆がメチル基、Ｒ₇及びＲ₈が水素でＸがメチレンである化合物、Ｒ₅及びＲ₆がメチル基、Ｒ₇及びＲ₈が水素でＸがチオである化合物、Ｒ₅、Ｒ₆及びＲ₇がメチル基、Ｒ₈が水素でＸがエチレンである化合物、Ｒ₅及びＲ₆がメチル基、Ｒ₇及びＲ₈が水素でＸがイソプロピリデンである化合物、Ｒ₅及びＲ₆がメチル基、Ｒ₇及びＲ₈が水素でＸがシクロヘキシリデンである化合物、Ｒ₅、Ｒ₆及びＲ₇がメチル基、Ｒ₈が水素でＸが両方のアリール基を直結している化合物、Ｒ₅、Ｒ₆及びＲ₇がメチル基、Ｒ₈が水素でＸがメチレンである化合物、Ｒ₅、Ｒ₆及びＲ₇がメチル基、Ｒ₈が水素でＸがエチレンである化合物、Ｒ₅、Ｒ₆及びＲ₇がメチル基、Ｒ₈が水素でＸがチオである化合物、Ｒ₅、Ｒ₆及びＲ₇がメチル基、Ｒ₈が水素でＸがイソプロピリデンである化合物、Ｒ₅、Ｒ₆、Ｒ₇及びＲ₈がメチル基でＸがメチレンである化合物、Ｒ₅、Ｒ₆、Ｒ₇及びＲ₈がメチル基でＸがエチレンである化合物、Ｒ₅、Ｒ₆、Ｒ₇及びＲ₈がメチル基でＸがイソプロピリデンである化合物等であるが、これらの例に限定されない。

A typical compound represented by the above formula is a compound in which R ₅ and R ₆ are methyl groups, R ₇ and R ₈ are hydrogen and X is directly connected to both aryl groups, and R ₅ and R ₆ are methyl groups. compound X R ₇ and R ₈ are hydrogen is methylene, R ₅ and R ₆ is a methyl group, compound R ₇ and R ₈ is X is hydrogen thio, R _5, R ₆ and R ₇ are methyl A group wherein R ₈ is hydrogen and X is ethylene, R ₅ and R ₆ are methyl groups, R ₇ and R ₈ are hydrogen and X is isopropylidene, R ₅ and R ₆ are methyl groups, R ₇ And R ₈ is hydrogen and X is cyclohexylidene, R ₅ , R ₆ and R ₇ are methyl groups, R ₈ is hydrogen and X is a direct connection of both aryl groups, R ₅ , R ₆ And R ₇ is a methyl group, R ₈ is hydrogen and X is methylene, R ₅ , R ₆ and R ₇ are methyl groups, R ₈ is hydrogen and X is ethylene Compound is, R _5, R ₆ and R ₇ is a methyl group, compounds X R ₈ is hydrogen is thio, R _5, R ₆ and R ₇ is a methyl group, with R ₈ is hydrogen X is isopropylidene A compound in which R ₅ , R ₆ , R ₇ and R ₈ are methyl groups and X is methylene, a compound in which R ₅ , R ₆ , R ₇ and R ₈ are methyl groups and X is ethylene, R ₅ , Examples include compounds in which R ₆ , R ₇ and R ₈ are methyl groups and X is isopropylidene, but are not limited to these examples.

  Furthermore, in addition to the above phenol compound, a polyhydric phenol compound can coexist. 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 the 2,6-positions of at least one phenolic hydroxyl group therein. Can be mentioned. Examples of polyphenol 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-methylphenyl) 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'-methylenebis [6-[(4-hydroxy- 3,5-dimethylphenyl) methyl] -4-methylphenol], 2,2'-methylenebis [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'-methylenebis [2-[(2,3,4-trihydroxyphenyl) Methyl] -3,6-dimethylphenol Nor], 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'-cyclohexylidenebis [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), etc. Including but not limited to. The number of phenolic hydroxyl groups is not particularly limited as long as it is 3 or more, but when the number increases, the color index value of polyphenylene ether before heating, the color index value of polyphenylene ether after heating, and the color before and after heating Since the rate of change of the index value may be large, it is preferably 3-6, more preferably 3-4, and the alkyl group or alkylene group at the 2,6-position 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).

  Polyphenylene ether can be produced by two kinds of production methods, precipitation polymerization method or solution polymerization method. Precipitation polymerization is preferable from the viewpoint of ease of production and adjustment of molecular weight, and more excellent in color tone. When obtained, the solution polymerization method is preferred.

  The precipitation polymerization method is a polymerization form in which polyphenylene ether having a predetermined molecular weight is precipitated. In the precipitation polymerization method, as the polymerization of polyphenylene ether proceeds, those having a molecular weight determined according to the solvent composition and the like are precipitated, and those having a molecular weight lower than that are dissolved. As the solvent, a mixed solvent of a good solvent of polyphenylene ether such as toluene, xylene or ethylbenzene and a poor solvent such as methanol or butanol is used. Since the deposited polyphenylene ether has a slow polymerization reaction rate, theoretically, the molecular weight distribution of the obtained polyphenylene ether becomes narrower. Furthermore, since polyphenylene ether precipitates during the polymerization, the viscosity in the system gradually decreases, so that the monomer concentration (phenol compound concentration) during the polymerization can be increased. Further, since the precipitated polyphenylene ether can be easily taken out by filtration, the polyphenylene ether can be obtained by an extremely simple process.

  On the other hand, the solution polymerization method is a polymerization method in which polymerization is performed in a good solvent of polyphenylene ether and no precipitate is deposited during the polymerization. All polyphenylene ether molecules are in a dissolved state, and the molecular weight distribution tends to be wide. In the solution polymerization method, a powdered polyphenylene ether is obtained by developing a polymerization solution in which polyphenylene ether is dissolved in a poor solvent of polyphenylene ether such as methanol.

  From the viewpoint of efficiently producing polyphenylene ether and from the viewpoint of producing polyphenylene ether having a specific molecular weight distribution, the monomer concentration is preferably 10 to 28 mass%, more preferably 15 to 25 mass%, based on the total amount of the polymerization solution. preferable. When the concentration is 10% by mass or more, the production efficiency of polyphenylene ether increases.

  On the other hand, when the concentration is 30% by mass or more, it tends to be impossible to adjust to a specific molecular weight. The present inventors presume this cause as follows. When the concentration is as high as 30% by mass or more, the liquid viscosity at the end of polymerization becomes high, and uniform stirring becomes difficult. Therefore, a heterogeneous reaction occurs, and an unexpected molecular weight polyphenylene ether may be obtained. For this reason, it may be difficult to efficiently produce a polyphenylene ether having a specific molecular weight that is suitable for the present embodiment.

  In the polymerization process of polyphenylene ether of the present embodiment, the polyphenylene ether can be obtained more efficiently by adding the phenol compound to be used after the start of polymerization in both precipitation polymerization and solution polymerization.

  In particular, in order to obtain a polyphenylene ether having a narrow molecular weight distribution, it is preferable to add 1 to 100% by mass of the total phenol compound used at the time of polymerization after the start of the polymerization. More preferably, it is 20-100 mass%, More preferably, it is 40-100 mass%, Most preferably, it is 50-100 mass%.

  In the polymerization process of the polyphenylene ether of the present embodiment, both precipitation polymerization and solution polymerization are performed while supplying an oxygen-containing gas.

  As the oxygen-containing gas, 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 or a rare gas at an arbitrary ratio. A mixture or the like can be used.

  The system pressure during the polymerization reaction may be ordinary pressure, but can be used under reduced pressure or increased pressure as necessary.

  The supply rate of the oxygen-containing gas can be arbitrarily selected in consideration of heat removal, polymerization rate, etc., but is preferably 5 NmL / min or more, and more preferably 10 NmL / min or more, as pure oxygen per mole of phenol compound used for polymerization. .

  To the polyphenylene ether polymerization reaction system, alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal alkoxides, neutral salts such as magnesium sulfate and calcium chloride, zeolite, and the like may be added.

  Further, a surfactant that has been conventionally known to have an effect of improving the polymerization activity may be added to the polymerization solvent. As such a surfactant, for example, trioctylmethylammonium chloride known as Aliquat 336 and CapRiquat (trade name, manufactured by Dojindo Laboratories Co., Ltd.) can be mentioned. The amount used is preferably within a range not exceeding 0.1 mass% with respect to the total amount of the polymerization reaction raw material.

  As the catalyst used for producing the polyphenylene ether of the present embodiment, a known catalyst system generally used for producing polyphenylene ether can be used.

  For example, there are transition metal ions having oxidation-reduction ability and amine compounds capable of complexing with the metal ions. Specifically, a catalyst system comprising a copper compound and an amine, and a manganese compound and an amine. Examples include a catalyst system and a catalyst system composed of a cobalt compound and an amine.

  Since the polymerization reaction proceeds efficiently under some alkaline conditions, some alkali or further amine may be added thereto.

  As a suitable catalyst in the manufacturing process of the polyphenylene ether of this Embodiment, the catalyst containing a copper compound, a halogen compound, and the diamine compound represented by following formula (3) as a structural component is mentioned.

上記式（３）中、Ｒ₉、Ｒ₁₀、Ｒ₁₁及びＲ₁₂は、それぞれ独立して、水素原子、炭素数１〜６の直鎖状又は分岐鎖状のアルキル基からなる群から選ばれるいずれかを示す。なお全てが同時に水素ではないものとする。Ｒ₁₃は炭素数２〜５の直鎖状又は分岐鎖状のアルキレン基を示す。

In said formula (3), R < ₉ >, R < ₁₀ >, R < ₁₁ > and R <_12> are each independently selected from the group which consists of a hydrogen atom and a C1-C6 linear or branched alkyl group. Indicates either. Note that all are not hydrogen at the same time. R ₁₃ represents a linear or branched alkylene group having 2 to 5 carbon atoms.

  As a copper compound which comprises a catalyst component, a cuprous compound, a cupric compound, or a mixture thereof can be used. Examples of the cuprous compound include cuprous chloride, cuprous bromide, cuprous sulfate, and cuprous nitrate. Examples of the cupric compound include cupric chloride, cupric bromide, cupric sulfate, cupric nitrate, and the like. Among these, particularly preferred copper compounds are cuprous chloride, cupric chloride, cuprous bromide, and cupric bromide.

  Moreover, you may synthesize | combine these copper compounds from the halogen or acid corresponding to an oxide (for example, cuprous oxide), carbonate, a hydroxide, etc.

  For example, it can be synthesized by mixing cuprous oxide and a halogen compound (for example, a solution of hydrogen halide). These copper compounds may be used alone or in combination of two or more.

  Examples of the halogen compound constituting the catalyst component 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, 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 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, As a halogen atom with respect to the molar amount of a copper atom, 2 times or more and 20 times or less are preferable, As a preferable usage-amount of a copper atom with respect to 100 mol of the phenol compound used Is in the range of 0.02 to 0.6 mol.

  Examples of the diamine compound represented by the above formula (3) include N, N, N ′, N′-tetramethylethylenediamine, N, N, N′-trimethylethylenediamine, N, N′-dimethylethylenediamine, and N, N. -Dimethylethylenediamine, N-methylethylenediamine, N, N, N ', N'-tetraethylethylenediamine, N, N, N'-triethylethylenediamine, N, N'-diethylethylenediamine, N, N-diethylethylenediamine, N-ethyl Ethylenediamine, N, N-dimethyl-N′-ethylethylenediamine, N, N′-dimethyl-N-ethylethylenediamine, Nn-propylethylenediamine, N, N′-di-n-propylethylenediamine, Ni-propylethylenediamine , N, N'-JIP Pyrethylenediamine, Nn-butylethylenediamine, N, N'-di-n-butylethylenediamine, Ni-butylethylenediamine, N, N'-di-butylethylenediamine, Nt-butylethylenediamine, N, N ' -Di-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'-te Ramechiru 1,5-diaminopentane, and the like.

Preferred diamine compounds are those in which the alkylene group (R ₁₃ ) connecting two nitrogen atoms has 2 or 3 carbon atoms.

  Although the usage-amount of these diamine compounds is not specifically limited, It is used in 0.01 mol-10 mol with respect to 100 mol of phenol compounds used normally.

  The other components constituting the polymerization catalyst will be described.

  In addition to the catalyst components described above, for example, a tertiary monoamine compound or a secondary monoamine compound may be contained alone or in combination in the polymerization catalyst used in the polymerization step.

  The tertiary monoamine compound is an aliphatic tertiary amine containing 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. The amount used is not particularly limited, but is preferably 15 mol or less with respect to 100 mol of the phenol compound to be polymerized.

  In the production of the polyphenylene ether of the present embodiment, it is not necessary to add all of the tertiary monoamine compounds that are usually used to the reaction system from the beginning. That is, some of them may be added in the middle, or some of them may be added sequentially from the start of polymerization. Moreover, you may add to the solution of a phenolic compound or a phenolic compound simultaneously with the start of superposition | polymerization, and may add with this.

  Secondary monoamine compounds include secondary aliphatic amines.

  Examples of secondary aliphatic amines include dimethylamine, diethylamine, di-n-propylamine, di-i-propylamine, di-n-butylamine, di-i-butylamine, di-t-butylamine, and dipentylamines. , Dihexylamines, dioctylamines, didecylamines, dibenzylamines, methylethylamine, methylpropylamine, methylbutylamine, and cyclohexylamine.

  Further, as the secondary monoamine compound, a secondary monoamine compound containing an aromatic can also be applied. For example, 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, diphenylamine and the like Can be mentioned. The above-mentioned secondary monoamine compounds may be used alone or in combination of two or more. Although the usage-amount of a secondary monoamine compound is not specifically limited, 15 mol or less is suitable with respect to 100 mol of phenol compounds to superpose | polymerize.

  In particular, in order to obtain the polyphenylene ether of the present embodiment, it can be more efficiently obtained by adding at least one or more tertiary monoamines after the start of polymerization. A more preferable method is a method in which at least one or more secondary monoamines and at least one or more tertiary monoamines are added after the start of polymerization. In order to obtain a polyphenylene ether having a particularly excellent color tone, it is preferable to add 1 to 99% by mass of the total amount of monoamine used during polymerization after the start of polymerization. More preferably, it is 1-50 mass%, More preferably, it is 1-25 mass%, More preferably, it is 1-20 mass%, Most preferably, it is 1-15 mass%. The monoamine added after the start of the polymerization may be added in the middle of the polymerization, or may be added sequentially. In particular, as the polymerization progresses, the amount of monoamine is gradually added to gradually increase the amine concentration involved in the polymerization reaction, thereby efficiently producing an excellent color tone and polyphenylene ether with suppressed color tone before and after heating. Can be obtained. When monoamine is added sequentially after the start of polymerization, the time required from the start of sequential addition to the end is not particularly limited, but from the viewpoint of efficiently obtaining polyphenylene ether, it is preferably within 60 minutes, more preferably Within 50 minutes, more preferably within 45 minutes, and most preferably within 40 minutes. Further, the addition start time of monoamine is preferably within 20 minutes from the start time of polymerization, and more preferably simultaneously with the start of polymerization. These monoamines may be mixed with other components used in the polymerization and added sequentially during the polymerization, but it is preferable to add them sequentially during the polymerization in order to narrow the molecular weight distribution.

  The post-treatment method after completion of the polymerization reaction is not particularly limited. Usually, an acid such as hydrochloric acid or acetic acid, ethylenediaminetetraacetic acid (EDTA) and a salt thereof, nitrilotriacetic acid and a salt thereof are used as a reaction solution. In addition, there is a method of deactivating the catalyst.

  Thereafter, since the polymerization solution at the end of the polymerization is in a state where polyphenylene ether is precipitated, repeated washing treatment is performed using a solution mainly composed of a solvent having low polyphenylene ether solubility for the purpose of washing and removing the catalyst. Preferably it is done.

  Thereafter, the polyphenylene ether can be recovered as a powder by performing drying using various dryers.

  The drying treatment is performed at a temperature of at least 60 ° C., preferably 80 ° C. or higher, more preferably 120 ° C. or higher, further preferably 140 ° C. or higher, and even more preferably 150 ° C. or higher.

  If the polyphenylene ether is dried at a temperature of less than 60 ° C., the aromatic hydrocarbon content in the polyphenylene ether may not be efficiently suppressed to less than 1.5% by mass.

  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.

  The drying process preferably uses a mixer. Examples of the mixer include a stirring type and a rolling type dryer. As a result, the processing amount can be increased and the productivity can be maintained high.

  The reduced viscosity (0.5 dl / g chloroform solution, measured at 30 ° C.) of the polyphenylene ether according to the present embodiment is 0.20 to 0.43 dl / from the viewpoint of excellent solubility, excellent coating properties and mechanical properties. The range of g is preferable, the range of 0.23 dl / g to 0.40 dl / g is more preferable, and the range of 0.25 to 0.38 dl / g is more preferable.

  The polyphenylene ether may be a blend of two or more polyphenylene ethers having different reduced viscosities. For example, a mixture of a polyphenylene ether having a reduced viscosity of 0.40 dl / g or less and a polyphenylene ether having a reduced viscosity of 0.45 dl / g or more may be used. The reduced viscosity of these mixtures is 0.20 to 0.43 dl. / G is preferable.

  The polyphenylene ether of the present embodiment can be melt kneaded with conventionally known thermoplastic resins and thermosetting resins.

  Examples of the thermoplastic resin and the thermosetting resin include polyethylene, polypropylene, thermoplastic elastomer, polystyrene, acrylonitrile / styrene resin, acrylonitrile / butadiene / styrene resin, methacrylic resin, vinyl chloride, polyamide, polyacetal, ultrahigh molecular weight polyethylene, Polybutylene terephthalate, polymethylpentene, polycarbonate, polyphenylene sulfide, polyether ketone, liquid crystal polymer, polytetrafluoroethylene, polyetherimide, polyarylate, polysulfone, polyethersulfone, polyamideimide, phenol, urea, melamine, unsaturated Examples thereof include resins such as polyester, alkyd, epoxy, diallyl phthalate, and bismaleimide.

  At the time of melt kneading, it is more preferable to add conventionally known additives and thermoplastic elastomers for the purpose of imparting effects such as conductivity, flame retardancy and impact resistance.

  Further, when the resin composition is produced using the polyphenylene ether of the present embodiment, other additives such as a plasticizer, a stabilizer, a modifier, an ultraviolet absorber, a flame retardant, a colorant, and a release agent. In addition, fibrous reinforcing agents such as glass fibers and carbon fibers, and fillers such as glass beads, calcium carbonate, talc, and clay may be added.

  Stabilizers and modifiers include phosphites, hindered phenols, sulfur-containing antioxidants, alkanolamines, acid amides, dithiocarbamic acid metal salts, inorganic sulfides, metal oxides, carboxylic anhydrides , Dienophile compounds such as styrene and stearyl acrylate, and epoxy group-containing compounds. These additives may be used alone or in combination of two or more.

  As a method for mixing the components constituting the resin composition, for example, a solution blending and degassing method, an extruder, a heating roll, a Banbury mixer, a kneader, a Henschel mixer and the like can be used.

  Hereinafter, the present embodiment will be specifically described with reference to examples and comparative examples, but the scope of the present embodiment is not limited to these examples.

  First, measurement methods such as physical properties and characteristics applied to Examples and Comparative Examples are shown below.

(1) Color index of polyphenylene ether and amount of change before and after heating The polyphenylene ether obtained in Examples and Comparative Examples was dissolved in chloroform to prepare a chloroform solution having a polyphenylene ether concentration of 0.05 g / mL.

  Into a quartz cell having a cell length of 1 cm, the same chloroform as that used for dissolving the polyphenylene ether was put, and the absorbance of pure chloroform was measured with ultraviolet rays (wavelength 480 nm) to obtain an absorbance of 0.

  The chloroform solution of the polyphenylene ether prepared above was put in the same cell, and the absorbance at 480 nm was measured.

  The value obtained by subtracting the absorbance of pure chloroform from the absorbance of polyphenylene ether in chloroform and dividing by the polyphenylene ether concentration in the chloroform solution of polyphenylene ether was used as the color index value of polyphenylene ether.

  For the polyphenylene ether after heating under the following conditions, the color index value was determined in the same manner as described above.

(Heating conditions)
Heating temperature: 310 ° C., heating time: 20 minutes, heating pressure: 10 MPa.

  The color index value of the polyphenylene ether before heating obtained above was calculated as C.I. I. ppe, and the color index value of the polyphenylene ether after heating is C.I. I. The amount of change (ΔC.I.) of the color index before and after heating was determined from the following equation as heat.

ΔC. I. = (C. I. heat-C. I. ppe) / C. I. ppe
(2) Quantification of phenolic hydroxyl group The polyphenylene ether obtained in Examples and Comparative Examples was dissolved in deuterated chloroform, and H-NMR (500 MHz made by JEOL) was measured using tetramethylsilane as an internal standard. Determination of the number of phenolic hydroxyl groups per 100 units of polyphenylene ether unit is determined by the peaks derived from polyphenylene ether terminal aromatic rings 3 and 5 (around 6.36 ppm), and the peaks derived from polyphenylene ether main chain aromatic rings 3 and 5 (6.3 to 6.7 ppm), calculated from the area ratio of each peak.

(3) Determination of components having a molecular weight of 8000 or less and components having a molecular weight of 50000 or more, and measurement of weight average molecular weight (Mw) / number average molecular weight (Mn) As a measuring device, Gel Permeation Chromatography System 21 manufactured by Showa Denko K.K. A calibration curve was prepared using standard polystyrene, and measurement was performed using this calibration curve.

  The molecular weight of standard polystyrene used was 3650000, 217000, 1090000, 681000, 204000, 52000, 30200, 13800, 3360, 1300, 550.

  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 solvent flow rate 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.

(4) 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.

<Example 1>
A 40 liter jacketed polymerization tank equipped with a sparger for introducing an oxygen-containing gas, a stirring turbine blade and a baffle at the bottom of the polymerization tank, and equipped with a reflux condenser in the vent gas line at the top of the polymerization tank was added to a 0.5 L / min. While blowing nitrogen gas at a flow rate, 4.02 g of cupric oxide, 29.876 g of 47 mass% hydrogen bromide aqueous solution, 9.684 g of di-t-butylethylenediamine, 44.88 g of di-n-butylamine, 130.24 g of butyldimethylamine, 19.65 kg of toluene and 2.12 kg of 2,6-dimethylphenol were added and stirred until a homogeneous solution was obtained and the internal temperature of the polymerization tank was 25 ° C.

  Next, dry air was introduced into the polymerization tank at a rate of 32.8 NL / min from a sparger and polymerization was started. Simultaneously with the start of the polymerization, a mixed solution consisting of 14.04 g of butyldimethylamine, 2.03 g of dibutylamine, 1.0 kg of toluene and 1.0 kg of 2,6-dimethylphenol was added over 30 minutes. Dry air was passed through for 86 minutes to obtain a polymerization mixture. The internal temperature at the end of the polymerization was controlled to 40 ° C. The polymerization solution at the end of the polymerization was in a solution state.

  The aeration of dry air was stopped, and 10 kg of a 2.5% aqueous solution of ethylenediaminetetraacetic acid tripotassium salt (a reagent manufactured by Dojindo Laboratories) was added to the polymerization mixture. The polymerization mixture was stirred at 70 ° C. for 120 minutes, returned to room temperature, and methanol was added excessively to prepare a slurry in which polyphenylene ether was precipitated. Then, the slurry was filtered using a basket centle (Tanabe Wiltech O-15 type). After filtration, excess methanol was added into the basket centre and filtered again to obtain wet polyphenylene ether.

  Next, wet polyphenylene ether was put into a Feather mill (FM-1S manufactured by Hosokawa Micron Co., Ltd.) with a 10 mm round hole mesh set, ground, and held at 150 ° C. and 1 mmHg for 1.5 hours to obtain a dried polyphenylene ether powder. Obtained. Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder. The results are shown in Table 1.

<Example 2>
In a 40 liter jacketed polymerization vessel, 4.02 g of cupric oxide, 29.876 g of 47% aqueous hydrogen bromide, 9.684 g of di-t-butylethylenediamine, 42.97 g of di-n-butylamine, 113.82 g of butyldimethylamine and 17.53 kg of toluene were added to start the polymerization. At the same time, 28.86 g of butyldimethylamine, 3.90 g of dibutylamine, 3.12 kg of toluene and 3.12 kg of 2,6-dimethylphenol A polyphenylene ether powder was obtained in the same manner as in Example 1 except that the mixed solution consisting of was added over 30 minutes. Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder. The results are shown in Table 1.

<Example 3>
In a 40 liter jacketed polymerization vessel, 4.07 g cupric oxide, 30.63 g 47% aqueous hydrogen bromide, 9.81 g di-t-butylethylenediamine, 44.31 g di-n-butylamine, 90.90 g of butyldimethylamine and 13.64 kg of toluene were added to start the polymerization. At the same time, butyldimethylamine 22.92 g, dibutylamine 3.2 g, toluene 3.12 kg, 2,6-dimethylphenol 3.12 kg A polyphenylene ether powder was obtained in the same manner as in Example 1 except that the mixed solution consisting of was added over 40 minutes. Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder. The results are shown in Table 1.

<Example 4>
A polyphenylene ether powder was obtained in the same manner as in Example 1 except that the time for introducing dry air from the sparger was 129 minutes. Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder. The results are shown in Table 1.

<Example 5>
A polyphenylene ether powder was obtained in the same manner as in Example 3 except that the time for introducing dry air from the sparger was 127 minutes. Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder. The results are shown in Table 1.

<Example 6>
A polyphenylene ether powder was obtained in the same manner as in Example 2 except that the time for introducing dry air from the sparger was 150 minutes. Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder. The results are shown in Table 1.

<Example 7>
A 40 liter jacketed polymerization tank equipped with a sparger for introducing an oxygen-containing gas, a stirring turbine blade and a baffle at the bottom of the polymerization tank, and equipped with a reflux condenser in the vent gas line at the top of the polymerization tank was added to a 0.5 L / min. While blowing nitrogen gas at a flow rate, 2.543 g of cupric chloride dihydrate, 9.856 g of 35 mass% hydrochloric acid, 86.342 g of N, N, N ′, N′-tetramethylpropanediamine, butyl Put dimethylamine 5.04 g, 27.95 g di-n-butylamine, 5.07 kg xylene, 5.07 kg n-butanol, 1.53 kg methanol, and 2.2 kg 2,6-dimethylphenol, The mixture was stirred until it became a homogeneous solution and the internal temperature of the polymerization tank reached 25 ° C.

  Subsequently, the oxygen-containing gas was introduced from the sparger into the vigorously stirred polymerization tank at a rate of 2.5 Nl / min, and polymerization was started. Simultaneously with the start of the polymerization, a mixed solution consisting of 0.84 g of butyldimethylamine, 2.03 g of dibutylamine, 1.0 kg of methanol and 1.0 kg of 2,6-dimethylphenol was added over 30 minutes. Oxygen-containing gas was passed through for 300 minutes to obtain a polymerization mixture. The internal temperature of the reactor was controlled to 40 ° C. Further, 105 minutes after the start of supply of the oxygen-containing gas, polyphenylene ether was precipitated and showed a slurry form. The polymerization solution at the end of the polymerization was in the state of a polymerization solution in which a precipitate was deposited.

  The ventilation of the oxygen-containing gas was stopped, and 10 kg of a 2.5 mass% aqueous solution of ethylenediaminetetraacetic acid tripotassium salt (a reagent manufactured by Dojindo Laboratories) was added to the polymerization mixture. Thereafter, the polymerization mixture was stirred for 120 minutes, and then hydroquinone (a reagent manufactured by Wako Pure Chemical Industries, Ltd.) was added little by little, and stirring was continued until the slurry-like polyphenylene ether became white. The internal temperature of the reactor was controlled to 50 ° C. The slurry which became white was filtered using a basket centle (Tanabe Wiltech O-15 type). After filtration, excess methanol was added into the basket centre and filtered again to obtain wet polyphenylene ether. The obtained wet polyphenylene ether was dried at 150 ° C. and 1 mmHg for 1.5 hours to obtain a dried polyphenylene ether powder. Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder. The results are shown in Table 1.

<Comparative Example 1>
A polyphenylene ether powder was obtained in the same manner as in Example 1 except that butyldimethylamine, dibutylamine and toluene were charged into the polymerization tank before the start of polymerization, not simultaneously with the start of polymerization. Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder. The results are shown in Table 2.

<Comparative example 2>
A polyphenylene ether powder was obtained in the same manner as in Example 4 except that butyldimethylamine, dibutylamine and toluene were charged into the polymerization tank before the start of polymerization, not at the same time as the start of polymerization. Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder. The results are shown in Table 2.

<Comparative Example 3>
A polyphenylene ether powder was obtained in the same manner as in Example 5 except that butyldimethylamine, dibutylamine and toluene were charged into the polymerization tank before the start of polymerization, not at the same time as the start of polymerization. Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder. The results are shown in Table 2.

<Comparative example 4>
A polyphenylene ether powder was obtained in the same manner as in Example 6 except that butyldimethylamine, dibutylamine and toluene were not simultaneously with the start of polymerization but were charged into the polymerization tank before the start of polymerization. Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder. The results are shown in Table 2.

<Comparative Example 5>
A polyphenylene ether powder was obtained in the same manner as in Example 1 except that the polymerization time was 65 minutes. Each measurement was performed by the method mentioned above about the obtained polyphenylene ether powder. The results are shown in Table 2.

実施例１〜７において、加熱前後での色調変化を効率的に抑制しながら、純度の高いポリフェニレンエーテルを得ることができた。特に実施例１〜３においては、フェノール性水酸基も充分に多く、さらに分子量５０，０００以上の成分が５〜２０質量％の範囲であり、分子量８，０００以下の成分が１２〜３０質量％の範囲である低分子量を有するポリフェニレンエーテルでありながらも、加熱前後の色調変化を抑制することができた。

In Examples 1-7, polyphenylene ether with high purity was able to be obtained, suppressing the color tone change before and behind heating efficiently. In particular, in Examples 1 to 3, the phenolic hydroxyl group is sufficiently large, the component having a molecular weight of 50,000 or more is in the range of 5 to 20% by mass, and the component having a molecular weight of 8,000 or less is 12 to 30% by mass. Although it was a polyphenylene ether having a low molecular weight in the range, the color tone change before and after heating could be suppressed.

  In Comparative Examples 1 to 4, since the tertiary monoamine and the secondary monoamine were not added during the polymerization, it is considered that the color tone before and after heating could not be efficiently suppressed.

  Since the polyphenylene ether of the present invention has little change in color tone and high purity, it is mechanical parts, automobile parts, electric and electronic parts, particularly electric and electronic parts such as printed circuit boards and insulating sealants, films, sheets, injection molded articles, blow moldings. There is industrial applicability as molded bodies, IC trays, medical equipment, arts, etc.

Claims (5)

[Delta] C. I. There Ri Der 0 or more and 7 or less,
A component having a molecular weight of 50,000 or more is contained in an amount of 5 to 20% by mass, and a component having a molecular weight of 8,000 or less is contained in an amount of 12 to 30% by mass;
Polyphenylene ether which is a homopolymer and / or copolymer having a repeating unit structure represented by the following formula (1) ;
ΔC. I. = (C. I. heat-C. I. ppe) / C. I. ppe
C. I. ppe: Color index value of polyphenylene ether before heating I. heat: Color index value of polyphenylene ether after heating
(Color index value of polyphenylene ether)
Polyphenylene ether is dissolved in chloroform to prepare a chloroform solution having a polyphenylene ether concentration of 0.05 g / mL. Into a quartz cell having a cell length of 1 cm, the same chloroform as that used for dissolving the polyphenylene ether is put, and the absorbance of pure chloroform is measured with ultraviolet rays (wavelength 480 nm) to obtain an absorbance of 0. The chloroform solution of the polyphenylene ether prepared above is put in the same cell, and the absorbance at 480 nm is measured. The value obtained by subtracting the absorbance of pure chloroform from the absorbance of polyphenylene ether in chloroform and dividing by the polyphenylene ether concentration in polyphenylene ether in chloroform is defined as the color index value of polyphenylene ether.
(Heating conditions for polyphenylene ether)
Heating temperature: 310 ° C., heating time: 20 minutes, heating pressure: 10 MPa.

(In the formula (1), R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 7 carbon atoms, a phenyl group, a haloalkyl group or an aminoalkyl group. , A hydrocarbonoxy group or a halohydrocarbonoxy group wherein at least two carbon atoms separate the halogen and oxygen atoms.)   The polyphenylene ether according to claim 1, wherein the number of phenolic hydroxyl groups is 0.6 or more per 100 units of the polyphenylene ether unit structure.   C. I. The polyphenylene ether according to claim 1 or 2, wherein ppe is 0.8 or less.   C. I. The polyphenylene ether according to any one of claims 1 to 3, wherein the heat is 4.0 or less. The polyphenylene ether according to any one of claims 1 to 4 , wherein the amount of residual nitrogen is 2000 ppm or less.