JP5960901B1 - Process for producing polyphenylene ether - Google Patents

Abstract

An object of the present invention is to provide a method for producing a polyphenylene ether capable of improving productivity per unit volume of a reactor while sufficiently suppressing foaming in the first stage of oxidative polymerization. A method for producing a polyphenylene ether according to the present invention is a polymerization prepared by adding a phenolic compound, an aromatic solvent and a catalyst to a polyphenylene ether having a reduced viscosity of 0.3 to 1.0 dL / g prepared in advance. An oxygen-containing gas is passed through the solution to oxidatively polymerize the phenolic compound. [Selection figure] None

Description

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

  Since polyphenylene ether is excellent in electrical insulation, heat resistance, hydrolysis resistance, and flame retardancy, the resin composition containing the polyphenylene ether is widely used in the fields of home appliances, OA equipment, automobile parts and the like. .

  Conventionally, various methods have been disclosed for producing polyphenylene ether by oxidative polymerization of a phenolic compound. For example, Patent Document 1 discloses a polyphenylene ether having a low molecular weight from a line bypassed from a main polymerization line while using a specific catalyst for the purpose of obtaining a bimodal molecular weight distribution by continuous polymerization of a phenolic compound. Is disclosed in a polymerization stop tank in a state where the polymerization is stopped. Further, Patent Document 1 adopts a slurry polymerization method in which the viscosity of the liquid does not increase so much by precipitating a part of the polyphenylene ether when the molecular weight of the polyphenylene ether increases. There is a description that can be obtained.

  On the other hand, in the solution polymerization method, which is a production method with higher productivity than the slurry polymerization method described above, the oxygen-containing gas is passed through the polymerization solution to oxidatively polymerize the phenolic compound. There is a problem that foaming of 10 to 30% of the volume occurs. In order to solve such a problem, for example, in the method disclosed in Patent Document 2, a polymerization solution composed of 10 to 25 parts by mass of a phenolic compound, 75 to 90 parts by mass of an aromatic solvent, and 0.1 to 10 parts by mass of a catalyst. Foaming is suppressed by adding 0.000001 to 0.0001 parts by mass of an antifoaming agent.

Japanese Patent Laid-Open No. 11-12354 JP 2010-270250 A

  However, when the polymerization reaction is performed by adding an antifoaming agent to the polymerization solution based on the technique described in Patent Document 2, there is a concern that the oxidative polymerization activity is lowered. Thus, in the prior art, in the production of polyphenylene ether, foaming is not sufficiently suppressed while maintaining the polymerization activity.

  The present invention has been made in view of the above problems, and provides a method for producing polyphenylene ether capable of improving productivity per unit volume of a reactor while sufficiently suppressing foaming in the first stage of oxidative polymerization. The purpose is to do.

  As a result of diligent research in view of the above object, the present inventors have dispersed a preoxidatively polymerized solution in a reactor for producing polyphenylene ether, for example, without passing through the foaming region in the previous polymerization reaction. The inventors have come up with the idea that oxidative polymerization can be completed, and have completed the present invention.

That is, the present invention is as follows.
The method for producing a polyphenylene ether of the present invention comprises a polymerization solution prepared by adding a phenolic compound, an aromatic solvent and a catalyst to a polyphenylene ether having a reduced viscosity of 0.3 to 1.0 dL / g prepared in advance. It has the superposition | polymerization process which ventilates gas and oxidatively polymerizes the said phenolic compound, It is characterized by the above-mentioned.
Here, the method for producing the polyphenylene ether of the present invention is a prepolymerization step in which an oxygen-containing gas is passed through a prepolymerization solution containing a phenolic compound, an aromatic solvent, and a catalyst to oxidatively polymerize the phenolic compound. A polyphenylene ether contained in at least a part of the organic phase obtained by separating the pre-polymerized polyphenylene ether using the organic phase and the aqueous phase. It is preferable that
In the method for producing polyphenylene ether of the present invention, the ratio of the amount of the prepared polyphenylene ether to the amount of the phenolic compound added to the polymerization solution is 10% by mass or more and 30% by mass or less. Is preferred.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the polyphenylene ether which can improve the productivity per unit volume of a reactor can be implement | achieved, fully suppressing the foaming before oxidative polymerization.

  Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist.

(Method for producing polyphenylene ether)
The method for producing polyphenylene ether of the present embodiment includes a polymerization step in which an oxygen-containing gas is passed through a polymerization solution containing a phenolic compound, an aromatic solvent, and a catalyst to oxidatively polymerize the phenolic compound in a reactor. Have
According to the polyphenylene ether production method of the present embodiment configured as described above, the oxidative polymerization can be completed without going through the foaming region of the oxidative polymerization pre-stage, so that the foaming of the oxidative pre-polymerization stage is sufficient. The productivity per unit volume of the reactor can be improved while suppressing.

  In this embodiment, a polymerization solution containing a phenolic compound, an aromatic solvent, a catalyst, and other materials as necessary is prepared and accommodated in a reactor, and an oxygen-containing gas is passed through the polymerization solution in the reactor. Then, polyphenylene ether can be obtained by oxidative polymerization of the phenolic compound.

  Hereinafter, the results obtained in the polymerization step (and the prepolymerization step) and raw materials (phenolic compounds, aromatic solvents, catalysts, and other materials) used in the polymerization step (and the prepolymerization step) will be described in detail.

<Polyphenylene ether>
The polyphenylene ether produced in the polymerization step in the method for producing polyphenylene ether of this embodiment will be described below.
The polyphenylene ether produced by the polymerization step is not particularly limited, but specifically, it is a homopolymer or copolymer having a repeating unit represented by the following formula (1).

・・・（１）
［上記式（１）において、Ｒ₁、Ｒ₄は、それぞれ独立して、水素、第一級又は第二級の低級アルキル、フェニル、アミノアルキル、及び炭化水素オキシからなる群より選ばれるいずれかを表し、Ｒ₂、Ｒ₃は、それぞれ独立して、水素、第一級又は第二級の低級アルキル、及びフェニルからなる群より選ばれるいずれかを表す。］

... (1)
[In the above formula (1), R ₁ and R ₄ are each independently selected from the group consisting of hydrogen, primary or secondary lower alkyl, phenyl, aminoalkyl, and hydrocarbonoxy. R ₂ and R ₃ each independently represents any one selected from the group consisting of hydrogen, primary or secondary lower alkyl, and phenyl. ]

  The homopolymer of polyphenylene ether is not particularly limited. Specifically, poly (2,6-dimethyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ) Ether, poly (2,6-diethyl-1,4-phenylene) ether, poly (2-ethyl-6-n-propyl-1,4-phenylene) ether, poly (2,6-di-n-propyl) -1,4-phenylene) ether, poly (2-methyl-6-n-butyl-1,4-phenylene) ether, poly (2-ethyl-6-isopropyl-1,4-phenylene) ether, poly (2 -Methyl-6-hydroxyethyl-1,4-phenylene) ether, poly (2-methyl-6-chloroethyl-1,4-phenylene) ether and the like. Among these, poly (2,6-dimethyl-1,4-phenylene) ether is preferable from the viewpoint that the raw materials are inexpensive and are easily available.

  The polyphenylene ether copolymer is a copolymer containing phenylene ether units as monomer units. The copolymer of polyphenylene ether is not particularly limited, and specifically, a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol, 2,6-dimethylphenol and o-cresol. And a copolymer of 2,6-dimethylphenol, 2,3,6-trimethylphenol and o-cresol. Among these, a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol is preferable from the viewpoint that the raw materials are inexpensive and are easily available.

  The reduced viscosity (ηsp / c) of the polyphenylene ether obtained by the production method of the present embodiment is preferably 0.3 to 1.0 dL / g. The reduced viscosity is a value measured under a temperature condition of 30 ° C. using a 0.5 g / dL chloroform solution. The reduced viscosity is more preferably in the range of 0.3 to 0.8 dL / g, and still more preferably in the range of 0.3 to 0.6 dL / g. When the reduced viscosity is 0.3 dL / g or more, the original mechanical strength of polyphenylene ether tends to be obtained. Moreover, it exists in the tendency for the effect which suppresses the excessive molecular weight rise at the time of polyphenylene ether polymerization to be acquired because the said reduced viscosity is 1.0 dL / g or less.

  As for the control method of the reduced viscosity, the reduced viscosity tends to increase by increasing the catalyst amount and the air flow rate and increasing the reaction time, and conversely, reducing the catalyst amount and the flow rate to shorten the reaction time. As a result, the reduced viscosity tends to be low.

・・・（２）
［上記式（２）において、Ｒ₅、Ｒ₇は、それぞれ独立して、水素、第一級又は第二級の低級アルキル、フェニル、アミノアルキル、及び炭化水素オキシからなる群より選ばれるいずれかを表し、Ｒ₆、Ｒ₈は、それぞれ独立して、水素、第一級又は第二級の低級アルキル、及びフェニルからなる群より選ばれるいずれかを表す。］ <Phenolic compound>
The phenolic compound used in the polymerization step (and preliminary polymerization step) in the method for producing polyphenylene ether of the present embodiment is a compound represented by the following formula (2).

... (2)
[In the above formula (2), R ₅ and R ₇ are each independently selected from the group consisting of hydrogen, primary or secondary lower alkyl, phenyl, aminoalkyl, and hydrocarbonoxy. R ₆ and R ₈ each independently represents any one selected from the group consisting of hydrogen, primary or secondary lower alkyl, and phenyl. ]

  Specific examples of the phenolic compound include, but are not limited to, 2,6-dimethylphenol, 2,3,6-trimethylphenol, 2-methyl-6-ethylphenol, 2,6-diethylphenol, 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, 2,6-diphenyl Phenol, 2,6-bis- (4-fluorophenyl) phenol, 2-methyl-6-tolylphenol, 2 6-ditolyl phenol, and the like. These phenolic compounds may be used alone or in combination of two or more. Even if the aromatic solvent used as the polymerization solution contains a small amount of phenol, o-cresol, m-cresol, p-cresol, 2,4-dimethylphenol, 2-ethylphenol, etc. as an impurity, it is phenolic. Since it is consumed by the polymerization reaction as part of the compound and incorporated into the polyphenylene ether, it can be substantially eliminated.

  Among these, the phenolic compound is preferably 2,6-dimethylphenol or a mixture of 2,6-dimethylphenol and 2,3,6-trimethylphenol, more preferably 2,6-dimethylphenol. preferable.

<Aromatic solvent>
Although it does not specifically limit as an aromatic solvent, Specifically, what melt | dissolves a low molecular weight phenolic compound and melt | dissolves a part or all of a catalyst can be used.

  Examples of such aromatic solvents include, but are not limited to, aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, and trichlorobenzene; nitrobenzene And nitro compounds. Among these, the aromatic solvent is preferably at least one selected from the group consisting of toluene, xylene, and ethylbenzene, and more preferably toluene.

  If necessary, the aromatic solvent can be mixed with a solvent having a property compatible with water. Although it does not specifically limit as a solvent which has a property compatible with water, Specifically, Alcohol, such as methanol, ethanol, and propanol; Ketone, such as acetone and methyl ethyl ketone; Ester, such as ethyl acetate and ethyl formate; Dimethylformamide, etc. And sulfoxides such as dimethyl sulfoxide. One or more of these solvents can be used in combination of two or more if necessary.

  As the aromatic solvent used in the polymerization step (and the preliminary polymerization step), those which are substantially incompatible with water can be preferably used. As those that are substantially incompatible with water, aromatic hydrocarbon solvents such as toluene and xylene are preferred.

  Further, the form of polymerization in the present embodiment varies depending on the selection of the ratio of good solvent to poor solvent for polyphenylene ether, which is a polymer obtained by oxidative polymerization of a phenolic compound. Specifically, it becomes a solution polymerization method by increasing the ratio of the good solvent, and it becomes a precipitation polymerization method in which the polymer is precipitated as particles in the reaction solvent as the ratio of the poor solvent is increased. . The form of polymerization in the present embodiment is not particularly limited, and a desired polymerization form can be appropriately selected by adjusting the amount of the poor solvent added to the aromatic solvent as necessary.

<Catalyst>
The catalyst is an effective oxidation catalyst for producing polyphenylene ether by efficiently oxidizing and polymerizing a phenolic compound by passing an oxygen-containing gas through a polymerization solution containing a phenolic compound, an aromatic solvent and a catalyst. is there.

  The catalyst is not particularly limited, and specifically includes a copper compound, a bromine compound, at least one selected from the group consisting of a diamine compound, a tertiary monoamine compound, and a secondary monoamine compound. The thing which contains a copper compound, a bromine compound, a diamine compound, a tertiary monoamine compound, and a secondary monoamine compound as an essential component is more preferable.

  Although it does not specifically limit as a copper compound used as a component of a catalyst, Specifically, a cuprous compound, a cupric compound, or mixtures thereof can be used. Although it does not specifically limit as a cuprous compound, Specifically, cuprous oxide, cuprous chloride, cuprous bromide, cuprous sulfate, cuprous nitrate, etc. are mentioned. Moreover, it is although it does not specifically limit as a cupric compound, Specifically, cupric chloride, cupric bromide, cupric sulfate, cupric nitrate, etc. are mentioned. Among these, preferred compounds for cuprous and cupric compounds are cuprous oxide, cuprous chloride, cupric chloride, cuprous bromide, and cupric bromide. In addition, these copper salts may be synthesized at the time of use from copper oxide, copper carbonate carbonate, copper hydroxide, and the like, and the corresponding halogen or acid. For example, cuprous bromide is obtained by mixing cuprous oxide and hydrogen bromide (solution thereof). A preferable copper compound is a cuprous compound. These copper compounds may be used alone or in combination of two or more.

  Although it does not specifically limit as a bromine compound used as a component of a catalyst, Specifically, hydrogen bromide, sodium bromide, potassium bromide, tetramethylammonium bromide, tetraethylammonium bromide, etc. are mentioned. In addition, these bromine compounds may be used in the form of an aqueous solution or a solution using an appropriate solvent. These bromine compounds may be used alone or in combination of two or more.

  A preferable combination of the above-described copper compound and bromine compound is an aqueous solution of cuprous oxide and hydrogen bromide. Although the usage-amount of these compounds is not specifically limited, The molar amount of a bromine atom is 2 times molar amount or more and 10 times molar amount or less with respect to the molar amount of a copper atom. Moreover, it is preferable that the ratio of the copper atom with respect to 100 mol of phenolic compounds is 0.02-0.6 mol.

・・・（３）
［上記式（３）において、Ｒ₁、Ｒ₂、Ｒ₃、Ｒ₄は、それぞれ独立して、水素、又は炭素数１〜６の直鎖状若しくは分岐状アルキル基であり、全てが同時に水素ではなく、Ｒ₅は、炭素数２〜５の、直鎖状若しくはメチル分岐を持つアルキレン基である。］ Although it does not specifically limit as a diamine compound used as a component of a catalyst, Specifically, the diamine compound etc. which are represented by following formula (3) are mentioned.

... (3)
[In the above formula (3), R ₁ , R ₂ , R ₃ and R ₄ are each independently hydrogen or a linear or branched alkyl group having 1 to 6 carbon atoms, all of which are simultaneously hydrogenated. R ₅ is an alkylene group having 2 to 5 carbon atoms and having a linear or methyl branch. ]

  Among the diamine compounds represented by the formula (3), N, N′-di-t-butylethylenediamine is preferable.

These diamine compounds may be used alone or in combination of two or more.
Although the usage-amount of a diamine compound is not specifically limited, It can be 0.5 times mole amount or more with respect to the mole amount of the copper atom normally used, and an upper limit is not specifically limited.

Although it does not specifically limit as a tertiary monoamine compound used as a component of a catalyst, The aliphatic tertiary amine containing an alicyclic tertiary amine, etc. are mentioned. The tertiary monoamine compound is not particularly limited. Specifically, trimethylamine, triethylamine, tripropylamine, tributylamine, triisobutylamine, dimethylethylamine, dimethylpropylamine, allyl diethylamine, N-butyl-dimethylamine, diethyl Examples include isopropylamine, N-methylcyclohexylamine and the like.
These tertiary monoamines may be used alone or in combination of two or more.
Although the usage-amount of a tertiary monoamine compound is not specifically limited, It is preferable that they are 0.1 mol-15 mol with respect to 100 mol of phenolic compounds.

  Although it does not specifically limit as a secondary monoamine compound used as a component of a catalyst, Specifically, a dimethylamine, diethylamine, di-n-propylamine, di-i-propylamine, di-n-butylamine, di-i -Butylamine, di-t-butylamine, dipentylamine, dihexylamine, dioctylamine, didecylamine, dibenzylamine, methylethylamine, methylpropylamine, methylbutylamine, cyclohexylamine, N (substituted or unsubstituted phenyl) alkanolamine, N- And hydrocarbon-substituted anilines.

  Although it does not specifically limit as said N (substituted or unsubstituted phenyl) alkanolamine, Specifically, N-phenylmethanolamine, N-phenylethanolamine, N-phenylpropanolamine, N- (m-methylphenyl) Examples include ethanolamine, N- (p-methylphenyl) ethanolamine, N- (2 ′, 6′-dimethylphenyl) ethanolamine, N- (p-chlorophenyl) ethanolamine and the like.

  The N-hydrocarbon substituted aniline is not particularly limited, and specifically includes N-ethylaniline, N-butylaniline, N-methyl-2-methylaniline, N-methyl-2,6-dimethylaniline, Examples include diphenylamine.

These 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, Generally it is the range of 0.05 mol-15 mol with respect to 100 mol of phenolic compounds.

<Other materials>
In the method for producing polyphenylene ether of the present embodiment, other materials that can be included in the polymerization solution (and the prepolymerization solution) are not limited to the following, but include, for example, a tetraalkylammonium salt compound, a polyethylene glycol group-containing alkylamine, and Examples include at least one selected from the group consisting of polyethylene glycol group-containing alkyl ammonium salt compounds.
From the viewpoint of improving the efficiency of the polymerization reaction, the content of the other materials may be contained in a range not exceeding 0.1% by mass with respect to 100% by mass of the polymerization solution (or prepolymerization solution). preferable.

  Specific examples of other materials include compounds represented by the following formula (4), (5), or (6).

・・・（４）
［上記式（４）において、Ｒ₁、Ｒ₂、Ｒ₃、Ｒ₄は、それぞれ独立して、炭素数１〜２２の直鎖状又は分岐状アルキル基であり、Ｘは、対となる陰イオンである。］

... (4)
[In the above formula (4), R ₁ , R ₂ , R ₃ and R ₄ are each independently a linear or branched alkyl group having 1 to 22 carbon atoms; Ion. ]

・・・（５）
［上記式（５）において、Ｒ₅は、炭素数１〜２２の直鎖状又は分岐状アルキル基を表し、Ｒ₆は、炭素数１〜２２の直鎖状又は分岐状アルキル基、−（ＣＨ₂ＣＨ₂Ｏ）_n−Ｈ［ｎは１〜４０の整数］で表される基を表し、Ｒ₇は、−（ＣＨ₂ＣＨ₂Ｏ）_n−Ｈ［ｎは１〜４０の整数］で表す。］

... (5)
[In the above formula (5), R ₅ represents a linear or branched alkyl group having 1 to 22 carbon atoms; R ₆ represents a linear or branched alkyl group having 1 to 22 carbon atoms; CH ₂ CH ₂ O) _n —H [n is an integer of 1 to 40], R ₇ is — (CH ₂ CH ₂ O) _n —H [n is an integer of 1 to 40]. Represented by ]

・・・（６）
［上記式（６）において、Ｒ₈、Ｒ₉は、炭素数１〜２２の直鎖状又は分岐状アルキル基を表し、Ｒ₁₀は、炭素数１〜２２の直鎖状又は分岐状アルキル基、−（ＣＨ₂ＣＨ₂Ｏ）_n−Ｈ［ｎは１〜４０の整数］で表される基を表し、Ｒ₁₁は、−（ＣＨ₂ＣＨ₂Ｏ）_n−Ｈ［ｎは１〜４０の整数］で表される基を表し、Ｘは、対となる陰イオンである。］

... (6)
[In the above formula (6), R ₈ and R ₉ represent a linear or branched alkyl group having 1 to 22 carbon atoms, and R ₁₀ represents a linear or branched alkyl group having 1 to 22 carbon atoms. , — (CH ₂ CH ₂ O) _n —H [n is an integer of 1 to 40], R ₁₁ represents — (CH ₂ CH ₂ O) _n —H [n is 1 to 40; An integer of X], and X is a paired anion. ]

In the above formula (4) and (6), X is preferably, Cl ^- is an anion selected from the group consisting of ^- and Br.

  In the method for producing polyphenylene ether of the present embodiment, as the other materials, more specifically, trioctyl known under the trade names of Aliquat 336 (manufactured by Henkel) and Capriquat (manufactured by Dojindo Laboratories). Methyl ammonium chloride is preferably used.

((Polymerization process))
Preparation of the polymerization solution in the polymerization step may be carried out by introducing polyphenylene ether, phenolic compound, aromatic solvent and catalyst components prepared in advance into the reactor, respectively, or preparing polyphenylene ether and phenolic in advance. The compound and the catalyst may be previously dissolved in an aromatic solvent and then introduced into the reactor. First, a catalyst previously dissolved in a part of the aromatic solvent is introduced into the reactor, and then the remaining It is preferred to introduce a phenolic compound dissolved in an aromatic solvent into the reactor.

  The temperature of the polymerization solution in the oxidative polymerization of polyphenylene ether is preferably adjusted to 0 to 80 ° C, more preferably 10 to 60 ° C, from the viewpoint of the progress of the reaction and the activity of the catalyst. More preferably, the temperature is adjusted to ° C. It is preferable to set the temperature lower in the first half of the polymerization process and higher in the second half of the polymerization process. Thereby, the progress of the polymerization reaction tends to be further promoted.

The polymerization solution in the polymerization step is 10 to 25 parts by mass of the phenolic compound, 75 to 90 parts by mass of the aromatic solvent, and 0.1 to 10 parts by mass of the catalyst, with the total of the phenolic compound and the aromatic solvent being 100 parts by mass. It is preferable to prepare at a blending ratio of
By setting it as such a mixture ratio, it exists in the tendency which can control the polymerization reaction of polyphenylene ether stably. The amounts of the phenolic compound, aromatic solvent, and catalyst in the polymerization solution are based on the mass when the introduction of the phenolic compound, aromatic solvent, and catalyst into the reactor is completed.

  In this embodiment, the total of the phenolic compound and the aromatic solvent is 100 parts by mass, and 12 to 23 parts by mass of the phenolic compound, 77 to 88 parts by mass of the aromatic solvent, and 0.5 to 9 parts by mass of the catalyst. It is more preferable to use a polymerization solution containing the phenolic compound and the aromatic solvent as a total of 100 parts by mass, 13 to 21 parts by mass of the phenolic compound, 79 to 87 parts by mass of the aromatic solvent, and 0.8 to 0.8 to the catalyst. It is more preferable to use a polymerization solution containing 8 parts by mass. By setting it as the said preferable mixture ratio, it exists in the tendency which can control the polymerization reaction of polyphenylene ether stably.

  The absolute pressure in the gas phase part of the reactor in the polymerization step is 0.098 MPa or more and 0.392 MPa or less. When the absolute pressure in the gas phase part of the reaction vessel exceeds 0.392 MPa, an excessive facility is required, which is not preferable. When the pressure is less than 0.098 MPa, it is not preferable because it is in a negative pressure region from the atmospheric pressure and equipment corresponding to vacuum is required.

(((Oxygen-containing gas ventilation))))
The start timing of the ventilation of the oxygen-containing gas is not particularly limited, but in the preparation of the polymerization solution, after introducing any of the prepared polyphenylene ether, phenolic compound, aromatic solvent, or catalyst into the reactor, the oxygen-containing gas It is preferable to start aeration.

  Although it does not specifically limit as oxygen-containing gas, Specifically, what mixed oxygen and arbitrary inert gas, what mixed air and air, and arbitrary inert gas can be used. Although it does not specifically limit as an inert gas, Specifically, unless the influence with respect to a polymerization reaction is large, arbitrary things can be used. A typical inert gas is nitrogen.

  The oxygen concentration of the oxygen-containing gas is not particularly limited. Specifically, it is preferably 5 to 25% by volume with respect to 100% by volume of the oxygen-containing gas, and particularly includes a nitrogen-containing gas and air. The oxygen concentration is more preferably 6 to 20% by volume, and still more preferably 8 to 12% by volume. With such a preferable oxygen concentration, the gradual heating, the polymerization rate and the like tend to be more stable.

  Further, when the oxygen concentration (the concentration of unreacted oxygen) in the oxygen-containing gas after venting exceeds 11.6%, nitrogen or the like is added to the reactor gas phase portion from the viewpoint of preventing explosion of the solvent used. It is preferable to introduce an inert gas and control the oxygen concentration to 11.6% or less.

  The air flow rate of the oxygen-containing gas is not particularly limited, but is preferably 0.5 to 15 NL / min, more preferably 3 to 14 NL / min with respect to 1 kg of the phenolic compound to be subjected to the polymerization reaction, More preferably, it is 6-13 NL / min. By setting it as 0.5 NL / min or more, the target polyphenylene ether reaches a desired molecular weight at an early stage, and the productivity tends to be improved. On the other hand, by setting it to 15 NL / min or less, the problems of excessive equipment and an increase in the amount of exhaust gas can be avoided, and the economy tends to be excellent.

  The absolute pressure in the gas phase part of the reactor is not particularly limited as long as it is within the allowable range of the reactor used for the oxidative polymerization, but specifically, it should be 0.294 MPa or more from the viewpoint of obtaining the effect of suppressing foaming. From the viewpoint of preventing excessive oxidation polymerization equipment, it is preferably 0.392 MPa or less.

During the oxidative polymerization of the phenolic compound, bubbles are generated in the reaction solution as the reaction proceeds. When the oxidative polymerization is continued and the phenolic compound in the polymerization solution is consumed, foaming stops, so that the polymerization solution foams at the beginning of the oxidative polymerization is related to the presence of a large amount of phenolic compound in the polymerization solution. It is assumed that there is.
In the first half of the oxidative polymerization reaction (first half), the bubble height increases with the progress of the reaction and then decreases rapidly. In the second half (late stage) of the oxidative polymerization reaction, the foam disappears. Here, the timing of shifting from the first half of the oxidative polymerization reaction (above) to the second half of the oxidative polymerization reaction (late stage) may be determined at the time when the foam height starts to decrease, It is preferable to do. In practice, the bubbles disappear completely in about 10 minutes after the height of the bubbles starts to decrease.

  As described above, a foamed layer may be generated at the initial stage of oxidative polymerization in a general polyphenylene ether polymerization process. In addition, about generation | occurrence | production of a foaming layer, it can evaluate by foaming amount and the said foaming amount can be measured by the method as described in the Example mentioned later.

  In the method for producing polyphenylene ether of the present embodiment, foaming of the polymerization solution can be suppressed by adding a previously prepared polyphenylene ether to the phenolic compound before oxidative polymerization in the polymerization step.

  In the method for producing polyphenylene ether of the present embodiment, since the generation of the foamed layer generated in the first stage of the polymerization process can be suppressed, the capacity of the reactor that is extra designed for the foamed layer portion of the polymerization solution in the prior art. Can be utilized.

In the present embodiment, the ratio of the amount of polyphenylene ether prepared in advance to the amount of the phenolic compound added to the polymerization solution is not particularly limited as long as the desired effect in the present embodiment can be ensured, but the polymerization activity is improved. And from the viewpoint of enabling shortening of the reaction time (polymerization time), it is preferably 10% by mass or more, more preferably 15% by mass or more, and 30% by mass from the viewpoint of considering the productivity of polyphenylene ether. % Or less, more preferably 25% or less, and still more preferably 20% or less.
In addition, about reaction time (polymerization time), it can measure by the method as described in the Example mentioned later.

  On the other hand, in this embodiment, from the viewpoint of considering the productivity of polyphenylene ether, the proportion of the phenolic compound in the polymerization solution in the polymerization step is preferably 25% by mass or less, more preferably 22% or less. More preferably, it is 20% or less.

(((Oxidative polymerization stop)))
After performing the polymerization step as described above, the polymerization reaction is stopped when the target degree of polymerization is reached.
The method for stopping the polymerization reaction is not particularly limited, and a conventionally known method can be applied. As a normal stopping method, there is a method of deactivating the catalyst by adding an acid such as hydrochloric acid or acetic acid, ethylenediaminetetraacetic acid (EDTA) and its salt, nitrilotriacetic acid and its salt to the reaction solution as a catalyst deactivator. Can be mentioned.
After termination of the polymerization, the produced polyphenylene ether is separated, washed with a solvent that does not dissolve the polyphenylene ether such as methanol, and dried to recover the polyphenylene ether.

  Here, the polyphenylene ether prepared in advance in the polymerization step of the polyphenylene ether production method of the present embodiment is not particularly limited, and can be obtained in the polymerization step of the polyphenylene ether production method of the present embodiment described above. The same as polyphenylene ether may be used.

Also, here, the previously prepared polyphenylene ether used in the polymerization step of the polyphenylene ether production method of the present embodiment is the above-described polymerization except that the prepared polyphenylene ether is not used from the viewpoint of production efficiency and production cost. It is preferable to use polyphenylene ether prepared by a prepolymerization step similar to the step.
In this case, the polyphenylene ether production method of the present embodiment is obtained by venting an oxygen-containing gas through a prepolymerization solution containing a phenolic compound, an aromatic solvent, and a catalyst before the above-described polymerization step. It further includes a prepolymerization step (described later) for subjecting the compound to oxidative polymerization.

((Preliminary polymerization process))
The pre-polymerization step may be the same as the above-described polymerization step except that the pre-prepared polyphenylene ether is not used. In the above-described polymerization step, adjustment of the polymerization solution, ventilation of oxygen-containing gas, oxidative polymerization stop, etc. It may be the same as those in the process.

In this embodiment, when shifting from the prepolymerization step to the polymerization step, at least a part of the organic phase obtained by separating the prepolymerized solution in the prepolymerization step in the reactor using the organic phase and the aqueous phase. It is important to continuously use (recycle) the phenolic compound and aromatic solvent in the prepolymerization step in the polymerization step.
By this liquid separation operation, the catalyst deactivator and water that can be contained in the prepolymerization solution are dissolved and removed in the aqueous phase, while the polyphenylene ether, unreacted phenolic compound, and fragrance produced in the prepolymerization step are removed. Group solvents and the like can be retained in the organic phase.

The above liquid separation operation for continuously using the prepolymerized solution after the oxidative polymerization is performed when the prepolymerized solution contains an organic solvent and water and forms an organic phase and an aqueous phase after the polymerization reaction is stopped. Otherwise, it may be performed while appropriately adding an organic solvent or water.
The preparation of the polymerization solution containing the organic phase obtained by this liquid separation operation is not particularly limited, but from the viewpoint of easy industrial implementation, the organic phase of the prepolymerization solution is once removed from the reactor in the prepolymerization step. After taking out and transferring to the reactor of another polymerization process, it is preferable to carry out in the reactor of this polymerization process. The polymerization solution may be prepared in a reactor for the prepolymerization step. In this case, in the reactor for the prepolymerization step, the aqueous phase that may contain the catalyst deactivator and water is removed, and the rephenylene ether is removed. It is important to leave a part of the organic phase containing unreacted phenolic compound, aromatic solvent and the like.

  As described above, a foamed layer may be generated at the initial stage of oxidative polymerization in a general polyphenylene ether polymerization step. In the method for producing a polyphenylene ether of a preferred embodiment of the present invention, polymerization in a prepolymerization step is performed. At least a part of the organic phase obtained by separating the solution using an organic phase and an aqueous phase is continuously used in the polymerization step, and polymerization is continued without going through the foaming region. Do. Thereby, in the polymerization process, the production efficiency per unit volume of the reactor can be improved.

In this way, the foaming of the polymerization solution is suppressed by adding polyphenylene ether, unreacted phenolic compound, aromatic solvent, etc. generated in the preliminary polymerization step to the phenolic compound before oxidative polymerization in the polymerization step. Can do.
Further, by using at least a part of the organic phase obtained by separating the polymerization solution in the prepolymerization step using an organic phase and an aqueous phase, the polymerization activity of the polymerization step is improved as compared with the prepolymerization step. . This production method makes it possible to fully utilize the capacity of the reactor by suppressing foaming in the first polymerization period.

  As a preferable form in the method for producing polyphenylene ether of the present embodiment, 2,6-dimethylphenol is used as a phenolic compound, cuprous oxide as a copper compound, hydrogen bromide as a bromine compound (used in an aqueous solution) ), N, N'-di-t-butylethylenediamine as diamine compound, N, N-di-n-butylamine as secondary monoamine compound, N, N-dimethyl-n-butylamine as tertiary monoamine However, the method for producing the polyphenylene ether of the present embodiment is not limited to this form.

  As described above, in the present embodiment, it is not necessary to have an antifoaming agent that affects the polymerization reaction in the polymerization solution, thereby reducing the activity of the polymerization reaction without reducing the polymerization reaction and polyphenylene. Ethers can be produced.

  Hereinafter, the present embodiment will be specifically described with reference to specific examples and comparative examples thereof. However, the present embodiment is not limited to the following examples. Measuring methods for physical properties and characteristics, etc. applied to the examples and comparative examples are shown below.

(1) Measurement of reduced viscosity (ηsp / c) A 0.5 g / dL chloroform solution of polyphenylene ether was prepared, and the reduced viscosity (ηsp / c) (dL / g) at 30 ° C. was obtained using an Ubbelohde viscometer. It was.

(2) Measurement of liquid level A scale is attached to the side of the reactor, and the contact between the liquid level and the side of the reactor from the bottom of the reactor (assuming zero point) (interface between liquid phase and foam) (Cm) was measured as the liquid level of the reaction solution. That is, in each example, the polymerization solution was stirred by starting the stirring at a constant stirring speed: 500 rpm immediately after the polymerization solvent was introduced into the reaction vessel, and measuring the distance every 10 minutes from the start of the oxidative polymerization. The height of the liquid level in the stirring state was measured, and the maximum value during the polymerization reaction period was defined as the height (cm) of the liquid level in each example.

(3) Measurement of foaming amount Under the same conditions as in the above-mentioned “Measurement of liquid level height”, the upper surface of the foamed layer on the liquid level and the reactor The distance (cm) to the contact portion with the side surface was measured as a value indicating the amount of foaming. In each example, the maximum value in the polymerization reaction period was set to a value (cm) indicating the foaming amount of each example.

(4) Measurement of foaming end time The time when foaming was completed in the polymerization solution was visually determined, and the time from the start of oxidative polymerization to the end of foaming was measured as the foaming end time (min).

(5) Measurement of liquid viscosity and measurement of polymerization time Using a vibrating liquid viscometer (manufactured by SEKONIC, VISCOMATE VM-100A), the temperature of the polymerization solution of each example sampled as described later was adjusted to 40 ° C. Then, the liquid viscosity (cP) of the solution was determined. Oxidation polymerization is started from the start of oxidative polymerization, with the time when the oxygen-containing gas starts to flow through the polymerization solution as the start time of oxidative polymerization and the time when the liquid viscosity reaches 250 cP. The polymerization time (min) until stopping was measured.

[Example 1]
The reactor is a cylindrical reactor with a maximum height of 50 cm and an inner diameter of 16 cm into which the reaction solution is put, and a sparger for introducing an oxygen-containing gas at the bottom of the reactor, a stirring turbine blade, and sampling A discharge valve was installed, a baffle and a temperature control device were installed on the side of the reactor, a polymerization solution inlet was installed at the top of the reactor, and a reflux condenser with a decanter for condensate separation was installed in the vent gas line. A 15-liter jacketed SUS reactor was used. At the vent gas outlet of the decanter, a pressure regulating valve and a pressure measuring device were installed.
As a liquid-liquid separator for a liquid separation operation, a cylindrical liquid-liquid separator with a maximum height of 50 cm and an inner diameter of 16 cm for containing a polymerization solution, a stirring turbine blade at the bottom of the separator, for sampling A discharge valve was provided, a baffle and temperature control device were provided on the side of the separator, a reflux condenser with a polymerization solution inlet and a decanter for condensate separation was provided at the top of the separator and a vent gas line. A 15-liter jacketed SUS liquid-liquid separator was used.

(Preliminary polymerization process)
2,6-dimethylphenol 1.08 kg, toluene 4.84 kg, and catalyst (2.5 g cuprous oxide, 15.2 g 47% aqueous hydrogen bromide, 6.1 g N, N′-di-t -Butylethylenediamine, 41.2 g N-butyl-dimethylamine, 11.4 g di-n-butylamine) 76.4 g, and the polymerization solution was introduced into the reactor. Was adjusted to 40 ° C., and the absolute pressure in the gas phase of the reactor was adjusted to 0.301 MPa. Thereafter, an oxygen-containing gas having an absolute pressure of 0.301 MPa and an oxygen concentration of 9% by volume was vented from a sparger as an aeration oxygen-containing gas, and oxidative polymerization of 2,6-dimethylphenol was started. (The oxygen partial pressure of this oxygen-containing gas was 0.301 (MPa) × 0.09 = 0.02709 (MPa)).
During the polymerization reaction, the height of the liquid surface was measured according to the method (2), and the amount of foaming was measured according to the method (3). Generation of bubbles was observed after the start of the oxidative polymerization, but it was recognized that the bubbles were completely eliminated 90 minutes after the start of the oxidative polymerization. Further, the foaming end time was measured according to the above method (4). Furthermore, sampling was carried out in small portions every 5 minutes from the time when 60 minutes of oxidative polymerization passed, the liquid viscosity was measured according to the method of (5) above, and the polymerization time was measured.
151 minutes after the start of oxidative polymerization, oxidative polymerization was stopped by adding 0.60 kg of 10% aqueous solution of ethylenediaminetetraacetic acid tetrasodium salt (produced by Dojindo Laboratories), and the polymerization solution was stirred at 70 ° C. for 150 minutes. Thereafter, the entire polymerization solution was extracted from the reactor and introduced into a liquid-liquid separator. Thereafter, the solution was allowed to stand for 60 minutes, and separated into an organic phase and an aqueous phase by liquid-liquid separation.

(Polymerization process)
1.20 kg (20% by mass) of the organic phase obtained in the prepolymerization step, 1.08 kg of 2,6-dimethylphenol, 4.84 kg of toluene, and catalyst (2.5 g of cuprous oxide, 15.2 g of 47 % Hydrogen bromide aqueous solution, 6.1 g of N, N′-di-t-butylethylenediamine, 41.2 g of N-butyl-dimethylamine, 11.4 g of di-n-butylamine), 76.4 g. A polymerization solution was prepared and introduced into the reactor, and the temperature of the polymerization solution was adjusted to 40 ° C. and the absolute pressure in the gas phase of the reactor was adjusted to 0.301 MPa. Thereafter, an oxygen-containing gas having an absolute pressure of 0.301 MPa and an oxygen concentration of 9% by volume was vented from a sparger as an aeration oxygen-containing gas, and oxidative polymerization of 2,6-dimethylphenol was started. (The oxygen partial pressure of this oxygen-containing gas was 0.301 (MPa) × 0.09 = 0.02709 (MPa)).
During the polymerization reaction, the height of the liquid level was measured according to the method (2), and the amount of foaming was measured according to the method (3). Generation of bubbles was observed after the start of the oxidative polymerization, but it was recognized that the bubbles were completely eliminated 90 minutes after the start of the oxidative polymerization. Further, the foaming end time was measured according to the method of (4) above. Furthermore, sampling was carried out in small portions every 5 minutes from the time when 60 minutes of oxidative polymerization passed, the liquid viscosity was measured according to the method of (5) above, and the polymerization time was measured.
After 146 minutes from the start of the oxidative polymerization, the oxidative polymerization was stopped by adding 0.60 kg of a 10% aqueous solution of ethylenediaminetetraacetic acid tetrasodium salt (produced by Dojindo Laboratories), and the polymerization solution was stirred at 70 ° C. for 150 minutes. Thereafter, the entire polymerization solution was extracted from the reactor and introduced into a liquid-liquid separator. Thereafter, the solution was allowed to stand for 60 minutes, and separated into an organic phase and an aqueous phase by liquid-liquid separation.
The obtained organic phase was precipitated and washed with 6.50 kg of methanol and then filtered to obtain wet polyphenylene ether. The obtained wet polyphenylene ether was dried at 150 ° C. for 120 minutes to obtain the polyphenylene ether of Example 1.

  Details and results of Example 1 are shown in Table 1.

[Example 2]
Except having used the organic phase obtained by the prepolymerization process for 0.60 kg (10 mass%) and the superposition | polymerization process, operation similar to Example 1 was performed and the polyphenylene ether of Example 2 was obtained. Details and results of Example 2 are shown in Table 1.

Example 3
A polyphenylene ether of Example 3 was obtained in the same manner as in Example 1 except that 1.80 kg (30% by mass) of the organic phase obtained in the prepolymerization process was used in the polymerization process. Details and results of Example 3 are shown in Table 1.

Example 4
The same operation as in Example 1 was carried out except that 0.30 kg (5% by mass) of the organic phase obtained in the prepolymerization step was used in the polymerization step, and the polyphenylene ether of Example 4 was obtained. Details and results of Example 4 are shown in Table 1.

Example 5
The same operation as in Example 1 was carried out except that 2.10 kg (35% by mass) of the organic phase obtained in the prepolymerization step was used in the polymerization step, and the polyphenylene ether of Example 5 was obtained. Details and results of Example 5 are shown in Table 1.

Example 6
1.20 kg (20% by mass) of the organic phase obtained in the prepolymerization step, 1.44 kg of 2,6-dimethylphenol, 6.46 kg of toluene, and catalyst (3.4 g of cuprous oxide, 20.3 g of 47% hydrogen bromide aqueous solution, 8.1 g di-t-butylethylenediamine, 15.2 g di-n-butylamine, 54.9 g butyldimethylamine) 101.9 g were used. Except for the above, the same operation as in Example 1 was performed to obtain the polyphenylene ether of Example 6. Details and results of Example 6 are shown in Table 1.

Example 7
The polyphenylene ether of Example 7 was obtained in the same manner as in Example 6 except that 1.80 kg (30% by mass) of the organic phase obtained in the prepolymerization process was used in the polymerization process. Details and results of Example 7 are shown in Table 1.

Example 8
In the prepolymerization step, 1.50 kg of 2,6-dimethylphenol, 4.39 kg of toluene, and catalyst (3.5 g of cuprous oxide, 21.0 g of 47% aqueous hydrogen bromide, 8.5 g of di-t A prepolymerization step using a polymerization solution composed of 106.1 g of butylethylenediamine, 15.9 g di-n-butylamine, 57.2 g butyldimethylamine), and in the polymerization step, prepolymerization 1.80 kg (30% by mass) of the organic phase obtained in the process, 1.50 kg of 2,6-dimethylphenol, 4.39 kg of toluene, and catalyst (3.5 g of cuprous oxide, 21.0 g of 47% An aqueous hydrogen bromide solution, 8.5 g of di-t-butylethylenediamine, 15.9 g of di-n-butylamine, 57.2 g of butyldimethylamine), 106.1 g. Except that the polymerization solution with which performs the same operation as in Example 1 to obtain a polyphenylene ether of Example 8. Details and results of Example 8 are shown in Table 1.

Example 9
0.22 kg of polyphenylene ether (Asahi Kasei Chemicals, S201A), 0.86 kg of 2,6-dimethylphenol, 4.84 kg of toluene, and catalyst (2.0 g of cuprous oxide, 12.1 g of 47% hydrogen bromide aqueous solution) 4.9 g di-t-butylethylenediamine, 9.1 g di-n-butylamine, 32.8 g butyldimethylamine) 60.9 g, and only one polymerization step. Except having been performed, operation similar to Example 1 was performed and the polyphenylene ether of Example 9 was obtained. In Example 9, generation of bubbles was observed after the start of oxidative polymerization, but it was recognized that the bubbles were completely eliminated 90 minutes after the start of oxidative polymerization. Details and results of Example 9 are shown in Table 1.

[Comparative Example 1]
1.26 kg 2,6-dimethylphenol, 5.65 kg toluene, and catalyst (3.0 g cuprous oxide, 17.8 g 47% aqueous hydrogen bromide, 7.1 g di-t-butylethylenediamine, 13 3 g of di-n-butylamine, 48.0 g of butyldimethylamine), and using the polymerization solution consisting of 89.2 g. The operation was performed to obtain polyphenylene ether of Comparative Example 1. In Comparative Example 1, generation of bubbles was observed after the start of oxidative polymerization, but it was recognized that the bubbles were completely removed 88 minutes after the start of oxidative polymerization. The details and results of Comparative Example 1 are shown in Table 1.

[Comparative Example 2]
1.44 kg 2,6-dimethylphenol, 6.46 kg toluene, and catalyst (3.4 g cuprous oxide, 20.3 g 47% aqueous hydrogen bromide solution, 8.1 g di-t-butylethylenediamine, 15 The same as in Example 1 except that only one polymerization step was performed using a polymerization solution composed of 101.9 g., 2 g di-n-butylamine, 54.9 g butyldimethylamine). The operation was performed and oxidative polymerization was started. At 80 minutes from the start of the oxidation polymerization, the amount of foaming was likely to exceed the upper limit of the reactor, so the oxidation polymerization was interrupted. The polyphenylene ether of Comparative Example 2 was not obtained. The details and results of Comparative Example 2 are shown in Table 1.

[Comparative Example 3]
4.80 kg of the polymerization solution obtained in the prepolymerization step was extracted, and 1.20 kg of an organic phase (including an aqueous phase) remained in the reactor in the prepolymerization step. Then, using this 1.20 kg polymerization solution, the same operation as in Example 1 was performed except that the polymerization step was performed in the reactor in the preliminary polymerization step, and oxidative polymerization was started. Even after 150 minutes from the start of the oxidation polymerization, the predetermined liquid viscosity was not reached, so the oxidation polymerization was interrupted. The polyphenylene ether of Comparative Example 3 was not obtained. Details and results of Comparative Example 3 are shown in Table 1.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the polyphenylene ether which can improve the productivity per unit volume of a reactor can be implement | achieved, fully suppressing the foaming before oxidative polymerization. The method for producing polyphenylene ether of the present invention has industrial applicability as a production technique for materials such as automobile parts, heat-resistant parts, electronic device parts, and industrial parts.

Claims (3)

An oxygen-containing gas is passed through a polymerization solution prepared by adding a phenolic compound, an aromatic solvent, and a catalyst to a polyphenylene ether having a reduced viscosity of 0.3 to 1.0 dL / g prepared in advance, and the phenolic compound A process for producing polyphenylene ether, characterized by comprising a polymerization step of oxidatively polymerizing. The method further comprises a prepolymerization step in which an oxygen-containing gas is passed through a prepolymerization solution containing a phenolic compound, an aromatic solvent and a catalyst to oxidatively polymerize the phenolic compound,
The polyphenylene ether prepared in advance is a polyphenylene ether contained in at least a part of an organic phase obtained by separating the prepolymerized solution after the preoxidative polymerization using an organic phase and an aqueous phase,
The manufacturing method of the polyphenylene ether of Claim 1.   The production of polyphenylene ether according to claim 1 or 2, wherein a ratio of the amount of the polyphenylene ether prepared in advance to the amount of the phenolic compound added to the polymerization solution is 10% by mass or more and 30% by mass or less. Method.