JP2010270248A - Method for producing polyphenylene ether - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress deposition to the inside of a reactor by effectively removing a polymerization solution, a catalyst component, etc., adhered to a foaming component in the early stages of oxidative polymerization. <P>SOLUTION: In a method for producing polyphenylene ether, polyphenylene ether is produced by passing oxygen-containing gas (O) through a polymerization solution comprising a phenolic compound (M), an aromatic solvent (A), and a catalyst (C) to perform oxidative polymerization of the phenolic compound (M). First, a first polymerization solution composed of 13-25 pts.mass of the phenolic compound (M), 35-82 pts.mass of the aromatic solvent (A1), and 0.1-10 pts.mass of the catalyst (C) is prepared. The oxygen-containing gas (O) is passed through the first polymerization solution to perform oxidative polymerization of the phenolic compound (M). The liquid surface of the polymerization solution is adjusted to substantially exceed the upper end of the foam upon foaming in the early stages of polymerization when the foaming of the polymerization solution occurred in the early stages of oxidative polymerization is substantially subsided, by additionally adding 5-52 pts.mass of the aromatic solvent (A2) containing substantially no phenolic compound (M) during the oxidative polymerization. The oxygen-containing gas (O) is continuously passed through to perform the oxidative polymerization, thereby obtaining the polyphenylene ether with ηsp/c of 0.3-1.0 dL/g. Wherein, the total pts.mass of the phenolic compound (M), the aromatic solvent (A1), and the aromatic solvent (A2) is 100 pts.mass. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention vents an oxygen-containing gas into a polymerization solution comprising a phenolic compound, a copper compound, a bromine compound, a diamine compound, a tertiary monoamine compound, a secondary monoamine compound, and an aromatic solvent. The present invention relates to a technique for improving the production amount per unit volume of a reactor used for production in a method for producing polyphenylene ether by oxidative polymerization of a phenolic compound.

Conventionally, various methods have been disclosed for producing polyphenylene ether by oxidative polymerization of a phenolic compound.
In Patent Documents 1 to 4, as an effective catalyst for oxidative polymerization of a phenolic compound, a catalyst in which a copper compound and an amine are combined, a catalyst in which a copper compound and a halogen compound are combined, a primary amine, a secondary amine, and a tertiary Catalysts using amines, monoamines, diamines, polyamines, and catalysts using tetraalkyl type diamines such as N, N, N ′, N′-tetramethyl-1,4-butanediamine are disclosed.
In Patent Documents 5 to 6, as a catalyst effective for oxidative polymerization, a catalyst in which a copper compound, an iodine compound and a tetraalkyl type diamine are combined is proposed.

Moreover, in patent documents 7-9, the catalyst which combined tertiary compounds, such as a copper compound, a bromine compound, and N, N'-di-t-butylethylenediamine and n-butyldimethylamine, a copper compound, a bromine compound, and tertiary Catalysts in combination with amines and secondary monoamines are disclosed.
Further, Patent Document 10 includes a copper compound and a secondary aliphatic amine or secondary aliphatic amine, an aniline having a special structure, and N, N, N ′, N′-tetramethyl 1,3-diaminopropane. Catalysts with improved water resistance are disclosed.
Patent Documents 11 to 13 disclose that by preparing a polymerization catalyst and a phenolic compound in an inert gas atmosphere, the catalyst is highly activated and the productivity of polyphenylene ether is improved.

Moreover, in the oxidative polymerization of a phenolic compound, there is a problem that the catalyst is deactivated by water generated as a by-product. As methods for overcoming this problem, Patent Documents 14 and 15 disclose oxidative polymerization methods for efficiently removing water.
In addition, in the oxidative polymerization of a phenolic compound, ensuring the safety is an important factor because an oxygen-containing gas is passed through a solution composed of an organic solvent and a phenolic compound to perform a polymerization reaction. As a method for ensuring safety, Patent Document 16 discloses a method for suppressing static electricity in oxidative polymerization.
Further, Patent Document 17 discloses a method for suppressing ignition by controlling the oxygen partial pressure of an oxygen-containing gas used for oxidative polymerization.

In the conventional method for producing polyphenylene ether, a sufficient polymerization rate can be secured at the beginning of oxidative polymerization, but at the end of oxidative polymerization, there is a problem that the polymerization rate is extremely reduced. Patent Document 18 and the like disclose a method for increasing the amount of oxygen-containing gas that flows to the polymerization solution at the end of oxidative polymerization.
In the conventional method for producing polyphenylene ether, the oxygen-containing gas is passed through the polymerization solution to oxidatively polymerize the phenolic compound. Therefore, at the initial stage of the oxidative polymerization, the volume of the polymer solution is 5% to 30% with respect to the volume of the polymerization solution. Foaming occurs.
For this reason, in the conventional method for producing polyphenylene ether, it is necessary to design the capacity of the reactor in consideration of the foamed portion in the initial stage of oxidative polymerization.

However, in the conventional method for producing polyphenylene ether, the foaming of the polymerization solution gradually stops as the oxidative polymerization proceeds, and the capacity considering the foamed portion is not effectively utilized at the end of the polymerization.
Further, in the conventional method for producing polyphenylene ether, there is a possibility that a polymerization solution, a catalyst component, etc. adhere to the foamed portion of the polymerization solution and become a cause of impurities.

Japanese Patent Publication 36-18692 US3306875 US3344116 US3432466 Shoko 52-17075 Shoko 52-17076 Shoko 58-53012 JP-B-59-53012 Japanese Patent Publication No.59-23332 JP-A 64-33131 JP 59-179620 JP-A-61-1453 JP2002-3596 JP2000-281776 JP 2001-342251 JP 2001-335631 A JP 2001-342250 A JP2002-3597

  Improve productivity by utilizing the foamed part at the beginning of oxidative polymerization. Effectively remove the polymerization solution and catalyst components adhering to the foamed part at the initial stage of oxidative polymerization to suppress the deposition on the inner surface of the reactor.

  In the conventional technique, the present inventor has effectively used the problem of the conventional method for producing polyphenylene ether, that is, the portion where the polymerization solution is foamed at the initial stage of polymerization, and further, the polymerization solution adhered to this portion, As a result of examining the effective removal of catalyst components and the like, the present invention has been completed.

That is,
1. A polyphenylene ether is produced by oxidative polymerization of the phenolic compound (M) by passing an oxygen-containing gas (O) through a polymerization solution comprising the phenolic compound (M), the aromatic solvent (A), and the catalyst (C). In the method, first, a first polymerization solution composed of 13 to 25 parts by mass of the phenolic compound (M), 35 to 82 parts by mass of the aromatic solvent (A1), and 0.1 to 10 parts by mass of the catalyst (C) is prepared. Then, an oxygen-containing gas (O) is passed through this to oxidatively polymerize the phenolic compound (M), and the aromatic solvent (A2) 5 to 52 that does not substantially contain the phenolic compound (M) during the oxidative polymerization. By adding an additional part by mass, when the foaming of the polymerization solution that occurs at the beginning of oxidative polymerization is substantially subsided, the liquid level of the polymerization solution is substantially exceeded the upper end of the foam at the time of foaming at the initial stage of polymerization. To adjust and continue Continuing oxygen-containing gas (O) oxidative polymerization by venting method for producing a polyphenylene ether .eta.sp / c is equal to or obtaining a polyphenylene ether 0.3~1.0dl / g. (Here, the total mass part of the phenolic compound (M), the aromatic solvent (A1) and the aromatic solvent (A2) is 100 parts by mass.)

2. 2. The method for producing polyphenylene ether according to 1 above, wherein the aromatic solvent (A2) is added by spraying from the upper part of the reactor, and added while removing the polymerization solution adhering to the inner wall of the reactor. .
3. As a method for preparing the first polymerization solution, a part of the phenolic compound (M) dissolved in a part of the aromatic solvent (A1) and the catalyst (C) are introduced into the reactor in advance. The method for producing a polyphenylene ether according to the above 1 or 2, wherein the first polymerization solution is prepared by introducing the remaining phenolic compound (M) dissolved in the remaining aromatic solvent (A1) into the reactor. .
4). The method for producing polyphenylene ether according to any one of the above 1 to 3, wherein 7 to 30 parts by mass of an aromatic solvent (A2) is additionally added. (Here, the total mass part of the aromatic solvent (A1) and the aromatic solvent (A2) is 75 to 87 parts by mass.)
5). The phenolic compound (M) is 2,6-dimethylphenol or a mixture of 2,6-dimethylphenol and 2,3,6-trimethylphenol, according to any one of the above 1 to 4, A method for producing polyphenylene ether.

6). The above-mentioned 1 to 3, wherein the catalyst (C) is a catalyst comprising (a copper compound and a bromine compound) and (one or more selected from a diamine compound, a tertiary monoamine compound, and a secondary monoamine compound). 6. A process for producing a polyphenylene ether according to any one of 5 above.
7). The method for producing a polyphenylene ether according to any one of the above 1 to 6, wherein the aromatic solvent (A) is toluene, xylene, or ethylbenzene.
8). 8. The method for producing polyphenylene ether according to any one of 1 to 7 above, wherein the oxygen-containing gas (O) is an oxygen-containing gas (O) having an oxygen concentration of 5 to 25% by volume.
9. 9. The oxygen-containing gas (O) according to any one of the above items 1 to 8, wherein the oxygen-containing gas (O) is an oxygen-containing gas (O) obtained by diluting air with a nitrogen-containing gas and adjusting the oxygen concentration to 6 to 20% by volume. Of producing polyphenylene ether.
10. An oxygen-containing gas (O) having an oxygen partial pressure of 0.00147 MPa or more and 0.0883 MPa or less is used, and the absolute pressure in the gas phase part of the reactor is controlled to 0.098 MPa or more and less than 0.392 MPa. 10. The method for producing polyphenylene ether according to any one of 1 to 9 above.

The production method of the present invention comprises a catalyst comprising a phenolic compound, a copper compound, a bromine compound, a diamine compound, a tertiary monoamine compound, and a secondary monoamine compound, and an oxygen-containing gas in a polymerization solution comprising an aromatic solvent. In the method of producing polyphenylene ether by ventilating (O) and oxidatively polymerizing phenolic compounds, the foamed part at the initial stage of oxidative polymerization can be used effectively, and the productivity per unit volume of the reactor used for production is improved. Has the effect of
Further, the production method of the present invention can effectively remove the polymerization solution, catalyst components, etc. adhering to the inner wall of the reactor by foaming at the initial stage of oxidative polymerization, can suppress the deposition on the inner surface of the reactor, It has the effect of obtaining a polyphenylene ether having a small content and excellent color tone.

The present invention will be specifically described below.
Examples of the polyphenylene ether of the present invention include a homopolymer or a copolymer having a repeating unit represented by the following formula (1).

(In the formula (1), R1 and R4 each independently represent hydrogen, primary or secondary lower alkyl, phenyl, aminoalkyl, or hydrocarbonoxy. R2 and R3 each independently represent Represents hydrogen, primary or secondary lower alkyl, and phenyl.)

“Specific examples of polyphenylene ether resin homopolymers include, for example, 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- Examples include 6-hydroxyethyl-1,4-phenylene) ether and poly (2-methyl-6-chloroethyl-1,4-phenylene) ether.
Of these, poly (2,6-dimethyl-1,4-phenylene) ether is particularly preferred. "

The polyphenylene ether resin copolymer is a copolymer containing a phenylene ether unit as a single unit. Specific examples thereof include, for example, a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol, a copolymer of 2,6-dimethylphenol and o-cresol, Examples thereof include a copolymer of dimethylphenol, 2,3,6-trimethylphenol, and o-cresol.
The phenolic compound used in the present invention is a compound having a structure represented by the following general formula (2).

(In the formula (1), R5 and R8 each independently represent hydrogen, primary or secondary lower alkyl, phenyl, aminoalkyl, or hydrocarbonoxy. R6 and R7 each independently represent Represents hydrogen, primary or secondary lower alkyl, and phenyl.)

Examples of such compounds include 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-diphenylphenol, 2,6-bis- (4-fluorophenyl) phenol, 2-methyl-6-tolylphenol, 2,6-ditolylphenol, etc. It is. These compounds may be used alone or in combination of two or more. Moreover, even if it contains a small amount of phenol, o-cresol, m-cresol, p-cresol, 2,4-dimethylphenol, 2-ethylphenol, etc., it does not interfere.
Among these phenolic compounds, 2,6-dimethylphenol or a mixture of 2,6-dimethylphenol and 2,3,6-trimethylphenol is preferable, and 2,6-dimethylphenol is particularly preferable.

The aromatic solvent used in the present invention is not particularly limited, but dissolves a low molecular weight phenolic compound and dissolves part or all of the catalyst mixture. Examples of such solvents include aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene, halogenated aromatic hydrocarbons such as chlorobenzene, dichlorobenzene, and trichlorobenzene, and nitro compounds such as nitrobenzene. be able to.
As the aromatic solvent used in the present invention, toluene, xylene or ethylbenzene is preferable, and toluene is very preferable.
In an amount as long as the effects of the present invention are not hindered, the aromatic solvent can be mixed with a solvent having a property compatible with water. Solvents that are compatible with water include, for example, alcohols such as methanol, ethanol, and propanol, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate and ethyl formate, amides such as dimethylformamide, and dimethyl sulfoxide. And sulfoxides such as One or more kinds of solvents can be further mixed if necessary.

The present invention can act particularly preferably as long as the solvent used is substantially incompatible with water. Examples of frequently used solvents are aromatic hydrocarbon solvents such as toluene and xylene. By selecting the ratio of good solvent and poor solvent for polyphenylene ether, which is a polymer obtained by oxidative polymerization of phenolic compounds, it can be used as a solution polymerization method, and by increasing the ratio of poor solvent, It is also a precipitation polymerization method in which the coalesced precipitate as particles in the reaction solvent.
The catalyst of the present invention is for producing a polyphenylene ether by efficiently oxidizing and polymerizing a phenolic compound by passing an oxygen-containing gas (O) through a polymerization solution comprising a phenolic compound, an aromatic solvent and a catalyst. It is an effective oxidation catalyst.

As the catalyst of the present invention, a catalyst having a copper compound, a bromine compound, a diamine compound, a tertiary monoamine compound, and a secondary monoamine compound as essential components can be preferably used.
As the copper compound used as the catalyst component of the present invention, a cuprous compound, a cupric compound or a mixture thereof can be used. Examples of the cuprous compound include cuprous oxide, cuprous chloride, cuprous bromide, cuprous sulfate, and cuprous nitrate. Examples of cupric compounds include cupric chloride, cupric bromide, cupric sulfate, and cupric nitrate. Among these, preferred compounds are cuprous oxide, cuprous chloride, cupric chloride, cuprous bromide and cupric bromide for cuprous and cupric compounds. These copper salts may be synthesized at the time of use from a halogen or an acid corresponding to an oxide, carbonate, hydroxide or the like. For example, it can be obtained by mixing cuprous oxide and hydrogen bromide (solution). A particularly preferable copper compound is a cuprous compound. These copper compounds may be used alone or in combination of two or more.

Examples of the bromine compound used as the catalyst component of the present invention include hydrogen bromide, sodium bromide, potassium bromide, tetramethylammonium bromide, tetraethylammonium bromide and the like. These can be used as an aqueous solution or a solution using an appropriate solvent. These bromine compounds may be used alone or in combination of two or more. The most preferred combination of 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, 2 times or more and 10 times or less are preferable as a bromine atom with respect to the molar amount of a copper atom, From 0.02 mol as a copper atom with respect to 100 mol of a phenolic compound. The range is 0.6 mol.
The diamine compound used as the catalyst component of the present invention is a diamine compound represented by the following general formula (3). Of the diamine compounds having the above structure, a preferred diamine compound is N, N′-di-t-butylethylenediamine. Although the usage-amount of a diamine compound is not specifically limited, It is 0.5 times mole amount or more with respect to the number-of-moles of copper atom normally used, and an upper limit is not critical.

(Wherein R1, R2, R3 and R4 are each independently hydrogen, a linear or branched alkyl group having 1 to 6 carbon atoms, and all are not simultaneously hydrogen. R5 is a straight chain having 2 to 5 carbon atoms. An alkylene group having a chain or a methyl branch.)

  The tertiary monoamine compound used as the catalyst component of the present invention is an aliphatic tertiary amine including an alicyclic tertiary amine. Examples include trimethylamine, triethylamine, tripropylamine, tributylamine, triisobutylamine, dimethylethylamine, dimethylpropylamine, allyldiethylamine, dimethyl-n-butylamine, diethylisopropylamine, N-methylcyclohexylamine and the like. These tertiary monoamines may be used alone or in combination of two or more. The amount of these used is not particularly limited, but a range of 0.1 mol to 15 mol is preferable with respect to 100 mol of the phenolic compound.

  Secondary monoamine compounds used as the catalyst component of the present invention are dimethylamine, diethylamine, di-n-propylamine, di-i-propylamine, di-n-butylamine, di-i-butylamine, di-t-butylamine, Examples include dipentylamines, dihexylamines, dioctylamines, didecylamines, dibenzylamines, methylethylamine, methylpropylamine, methylbutylamine, cyclohexylamine and the like. Examples of N- (substituted or unsubstituted phenyl) alkanolamines include N-phenylmethanolamine, N-phenylethanolamine, N-phenylpropanolamine, N- (m-methylphenyl) ethanolamine, N- (p-methyl). Phenyl) ethanolamine, N- (2 ′, 6′-dimethylphenyl) ethanolamine, N- (p-chlorophenyl) ethanolamine and the like. Examples of N-hydrocarbon substituted anilines include N-ethylaniline, N-butylaniline, N-methyl-2-methylaniline, N-methyl-2,6-dimethylaniline, diphenylamine, and the like. Is not limited. These secondary monoamine compounds may be used alone or in combination of two or more. The amount used is not particularly limited, but is generally in the range of 0.05 mol to 15 mol with respect to 100 mol of the phenolic compound.

  In the present invention, the addition of a tetraalkylammonium salt compound, a polyethylene glycol group-containing alkylamine, or a polyethylene glycol group-containing alkylammonium salt compound in a range not exceeding 0.1 wt% in the entire charged mixture can achieve the effects of the present invention. Although it is preferable because it is even more effective, it is not necessary to contain it. Examples of such compounds are those having a structure represented by the following general formula (4), (5) or (6).

(In the formula, R1, R2, R3 and R4 are each independently a linear or branched alkyl group having 1 to 22 carbon atoms, and X is a paired anion.)

(In the formula, R5 represents a linear or branched alkyl group having 1 to 22 carbon atoms, R6 in addition to the group defined in R5,-(CH2CH2O) n-H [n is an integer of 1 to 40] And R7 is a group represented by-(CH2CH2O) n-H [n is an integer of 1 to 40].

(In the formula, R8 and R9 each represent a linear or branched alkyl group having 1 to 22 carbon atoms, and R10 represents-(CH2CH2O) n-H [n is 1 to 40 in addition to the group defined as R8). R11 is a group represented by — (CH 2 CH 2 O) n —H [n is an integer of 1 to 40], and X is a paired anion. .)

  A representative example of such a compound that can be suitably used in the present invention is trioctylmethylammonium chloride known under the trade names of Aliquat 336 (manufactured by Henkel) and Capriquat (manufactured by Dojindo Laboratories).

Regarding the temperature of the polymerization solution of the present invention, if the temperature is too low, the reaction is difficult to proceed, and if it is too high, the catalyst may be deactivated, so that the temperature is 0 to 80 ° C., preferably 10 to 60 ° C. Is preferred. In many cases, good results are obtained when the temperature is set lower in the first half of the polymerization and higher in the second half of the polymerization.
In the method for preparing the first polymerization solution of the method for producing polyphenylene ether of the present invention, the components of the phenolic compound (M), the aromatic solvent (A1), and the catalyst (C) are individually introduced into the reactor. One polymerization solution may be prepared, and the phenolic compound (M) and the catalyst (C) are dissolved in the aromatic solvent (A1) in advance and introduced into the reactor to prepare the first polymerization solution. Also good.

As a method for preparing the first polymerization solution in the method for producing polyphenylene ether of the present invention, a preferred method is that a catalyst (C) dissolved in a part of the aromatic solvent (A1) is introduced into the reactor in advance, In this method, the first polymerization solution is prepared by introducing the phenolic compound (M) dissolved in the remaining aromatic solvent (A1) into the reactor.
As a method for preparing the first polymerization solution in the method for producing polyphenylene ether of the present invention, a more preferable method is one of the phenolic compounds (M) dissolved in advance in a part of the aromatic solvent (A1). And the catalyst (C) are introduced into the reactor, and then the remaining phenolic compound (M) dissolved in the remaining aromatic solvent (A1) is introduced into the reactor to prepare the first polymerization solution. is there.

The weight of the phenolic compound (M), aromatic solvent (A1), and catalyst (C) in the first polymerization solution in the method for producing polyphenylene ether of the present invention is the same as that in the preparation of the first polymerization solution. ) And the weight when the introduction of the catalyst (C) into the reactor is completed.
In this invention, it is preferable that the density | concentration of the phenolic compound with respect to a 1st polymerization solution is 15-40 mass%. In the present invention, the concentration of the phenolic compound is more preferably 18 to 37% by mass, particularly preferably 20 to 36% by mass, and most preferably 23 to 35% by mass.
In the method for producing the polyphenylene ether of the present invention, the start of aeration of the oxygen-containing gas (O) is not particularly limited, but in preparing the polymerization solution, the phenolic compound (M), the aromatic solvent (A), the catalyst (C) After introducing any of these into the reactor, it is preferable to start aeration of the oxygen-containing gas (O).

The oxygen-containing gas (O) in the present invention is prepared by mixing and adjusting oxygen and an arbitrary inert gas so that the oxygen concentration is within the range of the present invention, using air, or combining air and an arbitrary inert gas. Mix and adjust. Any inert gas can be used as long as it has no great influence on the polymerization reaction. Typically nitrogen.
In the present invention, the oxygen-containing gas (O) is preferably an oxygen-containing gas (O) having an oxygen concentration of 10 to 25% by volume. In the present invention, the oxygen-containing gas (O) is more preferably an oxygen-containing gas (O) obtained by diluting air with a nitrogen-containing gas and adjusting the oxygen concentration to 10 to 20% by volume.
In the present invention, when the oxygen concentration of the unreacted gas after aeration of the oxygen-containing gas (O) exceeds 11.6%, an inert gas such as nitrogen is introduced into the reactor gas phase, and the oxygen concentration Is controlled to 11.6% or less.
As a method for producing the polyphenylene ether of the present invention, an oxygen-containing gas (O) having an oxygen partial pressure of 0.0147 MPa or more and 0.0883 MPa or less is used, and the absolute pressure in the reactor gas phase is 0.098 MPa or more and 0.0. It is preferable to control to less than 392 MPa.

The aeration rate of the oxygen-containing gas (O) of the present invention is not particularly limited, but a preferable aeration rate is 0.5 Nl / min to 15 Nl / min with respect to 1 kg of the phenolic compound subjected to the polymerization reaction. This amount is not critical, but if it is too small, it takes a very long time to reach the desired molecular weight and the productivity deteriorates. On the other hand, if the amount is too large, problems such as excessive equipment and an increased amount of exhaust gas occur, which impairs economic efficiency.
The cause of the foaming of the polymerization solution at the initial stage of the oxidative polymerization is not clear, but since the foaming subsides when the oxidative polymerization is continued and the phenolic compound in the polymerization solution is consumed, the phenolic compound is present in the polymerization solution. It is thought that there is some relationship between this and foaming.

In the initial stage of the oxidative polymerization of the present invention, the volume of the portion where the polymerization solution is foamed varies depending on the components of the polymerization solution, the amount of oxygen-containing gas (O) flow, and the oxygen concentration of the oxygen-containing gas (O). The foamed part is generally 5 to 100 parts by volume with respect to 100 parts by volume which is not foamed.
When the foaming of the polymerization solution that occurs at the beginning of the oxidative polymerization of the present invention is substantially cured, the foamed part is approximately 1 part by volume or less with respect to 100 parts by volume of the non-foamed part of the polymerization solution, It means to be in a state of substantially not foaming.
In the method for producing polyphenylene ether of the present invention, when the foaming of the polymerization solution is substantially subsided, 5 to 52 parts by mass of the aromatic solvent (A2) that does not substantially contain the phenolic compound (M) is added. By adding, the 2nd polymerization solution in which a liquid level substantially exceeds the upper end of the foam at the time of foaming is adjusted. (Here, the total mass part of the aromatic solvent (A1) and the aromatic solvent (A2) is 100 parts by mass.)

In the method for producing polyphenylene ether of the present invention, the aromatic solvent (A2) preferably contains no phenolic compound (M).
In the method for producing polyphenylene ether of the present invention, it is preferable to add 7 to 30 parts by mass of the aromatic solvent (A2).
In the method for producing polyphenylene ether of the present invention, it is more preferable to add 10 to 25 parts by mass of the aromatic solvent (A2).
In the method for producing polyphenylene ether of the present invention, it is particularly preferable to add an additional 15 to 20 parts by mass of the aromatic solvent (A2).

In the present invention, in order to raise the liquid level of the second polymerization solution from the upper end of the foam at the time of foaming, the components of the polymerization solution adhering to the inner wall of the polymerization apparatus in the portion where the polymerization solution was foamed at the initial stage of oxidative polymerization are removed. It can be dissolved in the polymerization solution and removed.
Further, in the present invention, when the addition of the aromatic solvent (A2) is completed, since the foaming of the second polymerization solution is stopped, the polymerization solution component is newly fixed to the inner wall of the polymerization apparatus during the oxidative polymerization. There is no.
Further, the present invention adjusts the liquid level of the second polymerization solution to a position higher than the upper end of the foamed portion of the first polymerization solution, so that in the conventional method, a portion that was a dead space at the end of the polymerization Is effectively used.
Subsequently, in the present invention, the oxygen-containing gas (O) is continuously bubbled through the second polymerization solution for oxidative polymerization to obtain a desired ηsp / c polyphenylene ether.

In the present invention, the method of adding the aromatic solvent (A2) by spraying from the top of the reactor and adding it while removing the polymerization solution adhering to the inner wall of the reactor is the method of adding the deposit on the inner wall of the reactor. Since it can remove effectively, it can employ | adopt as a preferable method.
In this invention, it is preferable that the density | concentration of polyphenylene ether is 10-23 mass% with respect to a 2nd polymerization solution. In the present invention, the concentration of the polyphenylene ether is more preferably 13 to 22% by mass, particularly preferably 15 to 21% by mass, and most preferably 16 to 20% by mass.
In the present invention, after the foaming of the polymerization solution that occurs at the beginning of the oxidative polymerization is substantially subsided, an additional aromatic solvent is added to dilute the polymerization solution so that the liquid surface of the polymerization solution is substantially expanded. Adjust to be higher than the height of the top of the foam.

That is, in the present invention, at the time when oxidative polymerization is started, foaming of the first polymerization solution that occurs in the initial stage of oxidative polymerization of the polymerization solution in which the concentration of the phenolic compound was 15 to 60% by mass was substantially subsided. Later, in order to eliminate adverse effects such as poor stirring due to the increase in viscosity of the polymer of the phenolic compound, that is, the polymerization solution due to the increase in the molecular weight of polyphenylene ether, an aromatic solvent was added and the polymerization solution was added. It is diluted and adjusted so that the concentration of polyphenylene ether is in the range of 10 to 23% by mass.
Further, in the present invention, the liquid level of the polymerization solution is adjusted to substantially the height of the upper end of the foam at the time of foaming, so that the components of the polymerization solution adhering to the foamed part are removed and washed during the polymerization. Avoid accumulation in the vessel.

The method for stopping the polymerization reaction of the present invention 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 added to the reaction solution to deactivate the catalyst, and the polymerization is stopped.
After termination of the polymerization, the produced polymer is separated, washed with a solvent that does not dissolve the polymer such as methanol, and dried to recover polyphenylene ether.

The present invention will be described based on examples.
A general procedure in Examples and Comparative Examples is described below.

[General procedure]
In the examples and comparative examples of the present invention, as a reactor, a sparger for introducing an oxygen-containing gas (O), a stirring turbine blade, and a sampling discharge valve are provided at the bottom of a cylindrical reactor having an inner diameter of 16 cm. A baffle, temperature control device, and a viewing window for checking the internal state are provided on the side of the reactor, and a polymerization solution component inlet and a decanter for condensate separation are attached to the vent gas line at the top of the reactor. A 10 liter jacketed autoclave reactor equipped with a reflux condenser with control valve was used.
In Examples and Comparative Examples of the present invention, 2,6-dimethylphenol was used as the phenolic compound (M).
In Examples and Comparative Examples of the present invention, toluene was used as the aromatic solvent (A1) and (A2).

The addition amount of each component of the catalyst (C) used in all Examples and Comparative Examples of the present invention is 1.288 g of cuprous oxide and 47% aqueous solution of hydrogen bromide with respect to 1000 g of 2,6-dimethylphenol. 7.749 g, N, N′-di-t-butylethylenediamine; 3.104 g, dimethyl-n-butylamine; 38.11 g, di-n-butylamine;
In Examples and Comparative Examples of the present invention, an oxygen-containing gas (O) having an absolute pressure of 0.108 MPa and an oxygen concentration of 15% was used as the oxygen-containing gas (O) to be vented. (The oxygen partial pressure of this oxygen-containing gas (O) is 0.108 MPa × 0.15 = 0.0162 MPa.)
In the examples and comparative examples of the present invention, the oxygen-containing gas (O) was vented at 4 Nl / min · kg with respect to 1 kg of 2,6-dimethylphenol in the first polymerization solution.

In the examples and comparative examples of the present invention, 1 Nl / min nitrogen was introduced into the gas phase part of the reactor for safety. In addition, a control valve downstream of the reflux condenser was adjusted to control the pressure in the gas phase part of the reactor to 0.108 MPa.
In the examples and comparative examples of the present invention, first, a first polymerization solution composed of toluene, 2,6-dimethylphenol and the catalyst (C) in the amounts specified in the examples and comparative examples was prepared and reacted. It introduce | transduced into the inlet of the vessel, and adjusted the temperature of the 1st polymerization solution to 40 degreeC. Until the completion of oxidative polymerization, the temperature of the polymerization solution was adjusted to 40 ° C.
In Examples and Comparative Examples of the present invention, the first polymerization solution was stirred, and oxygen-containing gas (O) was introduced from a sparger to perform oxidative polymerization. The time when the introduction of the oxygen-containing gas (O) was started was taken as the polymerization start time.
In the Examples and Comparative Examples of the present invention, the foaming of the first polymerization solution was observed from the viewing window, and when the fine bubbles disappeared, toluene was introduced into the reactor to prepare the second polymerization solution.

In the examples and comparative examples of the present invention, an aqueous solution of EDTA tetrasodium salt was added from the introduction port to stop the oxidative polymerization.
In the examples and comparative examples of the present invention, after the aqueous phase was separated from the second polymerization solution, the second polymerization solution was dropped into an equal volume of methanol to precipitate polyphenylene ether.
The precipitated polyphenylene ether was further washed three times with an equal volume of methanol, filtered, and then vacuum dried at 145 ° C. to obtain a measurement polyphenylene ether.
In Examples and Comparative Examples of the present invention, a chloroform solution having a polyphenylene ether concentration of 0.5 g / dl was prepared, and ηsp / c was measured using an Ubbelohde viscometer.

[Example 1]
2,6-dimethylphenol; 1.51 kg and toluene; 3.89 kg, a first polymerization solution composed of a specified amount of catalyst (C) defined in the general procedure was prepared and introduced into the reactor. Then, after adjusting the liquid temperature to 40 ° C., oxygen-containing gas (O) was passed through a sparger to oxidatively polymerize 2,6-dimethylphenol. When oxidative polymerization was started, foaming of the polymerization solution was observed. The height from the liquid level to the top of the foamed part was 10 cm at the maximum, and the height from the lower end of the reactor was 36 cm. After the start of polymerization, the foaming was cured in 52 minutes. In the foamed portion, deposition of a polymerization solution and a catalyst component was observed. When 3 kg of toluene was added and added from the introduction port to adjust the second polymerization solution, the height of the polymerization solution from the lower end of the reactor was 44 cm. Oxygen-containing gas (O) was continuously vented, but no bubbling was observed. The oxidative polymerization was stopped 150 minutes after the start of the oxidative polymerization, and polyphenylene ether for measurement was obtained according to a general procedure.
The amount of polyphenylene ether for measurement obtained was 1.43 kg.
The polyphenylene ether for measurement had a ηsp / c of 0.76.
After discharging the polyphenylene ether, the polymerization solution and catalyst components were not deposited in the reactor.

[Comparative Example 1]
2,6-dimethylphenol; 1.26 kg and toluene; 5.74 kg, a polymerization solution composed of a specified amount of catalyst (C) defined in the general procedure was prepared, and this was introduced into the reactor, After adjusting the liquid temperature to 40 ° C., oxygen-containing gas (O) was passed through a sparger to oxidatively polymerize 2,6-dimethylphenol. When oxidative polymerization was started, foaming of the polymerization solution was observed. The height from the liquid level to the upper part of the foamed part was 13 cm at the maximum, and the height from the lower end of the reactor was 47 cm. After 54 minutes of polymerization, the foaming stopped. In the foamed portion, deposition of a polymerization solution and a catalyst component was observed. Oxygen-containing gas (O) was continuously vented, but no bubbling was observed. The oxidative polymerization was stopped 150 minutes after the start of the oxidative polymerization, and polyphenylene ether for measurement was obtained according to a general procedure.
The amount of polyphenylene ether for measurement obtained was 1.18 kg.
The polyphenylene ether for measurement had a ηsp / c of 0.74.
After discharging the polyphenylene ether, deposition of a polymerization solution and a catalyst component was observed inside the reactor.

[Comparative Example 2]
2,6-dimethylphenol; 1.51 kg and toluene; 6.89 kg, a polymerization solution composed of a specified amount of catalyst (C) defined in the general procedure was prepared, and this was introduced into the reactor, After adjusting the liquid temperature to 40 ° C., oxygen-containing gas (O) was passed through a sparger to oxidatively polymerize 2,6-dimethylphenol. When oxidative polymerization was started, foaming of the polymerization solution was observed. The foamed polymerization solution entered the vent gas line at the top of the reactor and was ejected from the gas line outlet. Since oxidative polymerization could not be continued, it was interrupted.
No polyphenylene ether for measurement was obtained.
After discharging the polymerization solution, deposition of the polymerization solution and catalyst components was observed at the top of the reactor and inside the vent gas line.

[Comparative Example 3]
2,6-dimethylphenol; 1.51 kg and toluene; 5.49 kg, a polymerization solution composed of a specified amount of catalyst (C) defined in the general procedure was prepared, and this was introduced into the reactor, After adjusting the liquid temperature to 40 ° C., oxygen-containing gas (O) was passed through a sparger to oxidatively polymerize 2,6-dimethylphenol. When oxidative polymerization was started, foaming of the polymerization solution was observed. The height from the liquid level to the top of the foamed part was 14 cm at the maximum, and the height from the lower end of the reactor was 48 cm. After the start of polymerization, foaming was cured in 55 minutes. In the foamed portion, deposition of a polymerization solution and a catalyst component was observed. Oxygen-containing gas (O) was continuously vented, but no bubbling was observed. Since the viscosity of the polymerization solution increased 145 minutes after the start of oxidative polymerization and stirring could not be continued sufficiently, the oxidative polymerization was stopped.
The amount of polyphenylene ether for measurement obtained was 1.17 kg.
The polyphenylene ether for measurement had a ηsp / c of 0.70.
After discharging the polyphenylene ether, a large amount of polymerization solution and deposits of catalyst components were observed inside the reactor.

[Example 2]
2,6-dimethylphenol; 1.26 kg and toluene; 3.24 kg, a polymerization solution composed of a specified amount of catalyst (C) defined in the general procedure was prepared, and this was introduced into the reactor, After adjusting the liquid temperature to 40 ° C., oxygen-containing gas (O) was passed through a sparger to oxidatively polymerize 2,6-dimethylphenol. When oxidative polymerization was started, foaming of the polymerization solution was observed. The height from the liquid level to the upper part of the foamed part was 8 cm at the maximum, and the height from the lower end of the reactor was 38 cm. After the start of polymerization, the foaming was cured in 52 minutes. Toluene; 2.5 kg was further added at an addition rate of 5 kg / hour from a shower-type spray nozzle for 30 to 60 minutes after the start of polymerization. Oxygen-containing gas (O) was continuously vented, but no bubbling was observed. The oxidative polymerization was stopped 150 minutes after the start of the oxidative polymerization, and polyphenylene ether for measurement was obtained according to a general procedure.
The amount of polyphenylene ether for measurement obtained was 1.2 kg.
The polyphenylene ether for measurement had a ηsp / c of 0.75.
After discharging the polyphenylene ether, the polymerization solution and catalyst components were not deposited in the reactor.

  The production method of the present invention comprises a phenolic compound, a copper compound, a bromine compound, a diamine compound, a tertiary monoamine compound, a catalyst composed of a secondary monoamine compound, and a polymerization solution consisting of an aromatic solvent and a phenolic compound. It can be suitably used in the field of producing polyphenylene ether by oxidative polymerization of a compound.

Claims (7)

  A polymerization solution composed of 10 to 25 parts by mass of the phenolic compound (M), 75 to 90 parts by mass of the aromatic solvent (A) and 0.1 to 10 parts by mass of the catalyst (C) was prepared, and oxygen was added thereto. In the method of oxidative polymerization of the phenolic compound (M) by passing an oxygen-containing gas (O) having a concentration of 5 to 25% by volume, the absolute pressure (P1) in the gas phase part of the reactor at the initial stage of oxidative polymerization is set to 0.098 MPa ( Megapascal) to 0.292 MPa, the absolute pressure (P2) in the reactor gas phase after the middle of oxidative polymerization is adjusted to (P1 + 0.0049) to 1.47 MPa, and ηsp / c 0.3 to 1.0 dl / G polyphenylene ether is obtained, The manufacturing method of polyphenylene ether characterized by the above-mentioned. (Here, the total mass part of the phenolic compound (M) and the aromatic solvent (A) is 100 parts by mass.)   The absolute pressure (P1) in the reactor gas phase at the initial stage of oxidative polymerization was adjusted to 0.108 MPa (megapascal) to 0.196 MPa, and the absolute pressure (P2) in the reactor gas phase after the middle of oxidative polymerization was (P1 + 0). .0049) to 0.49 MPa, The method for producing a polyphenylene ether according to claim 1.   The polyphenylene ether according to claim 1 or 2, wherein the phenolic compound (M) is 2,6-dimethylphenol or a mixture of 2,6-dimethylphenol and 2,3,6-trimethylphenol. Production method.   The catalyst (C) is a catalyst comprising (a copper compound and a bromine compound) and (one or more selected from a diamine compound, a tertiary monoamine compound, and a secondary monoamine compound). The manufacturing method of polyphenylene ether of any one of -3.   The method for producing a polyphenylene ether according to any one of claims 1 to 4, wherein the aromatic solvent (A) is toluene, xylene, or ethylbenzene.   The oxygen-containing gas (O) is an oxygen-containing gas (O) prepared by diluting air with a nitrogen-containing gas and adjusting the oxygen concentration to 6 to 20% by volume. The manufacturing method of polyphenylene ether as described in claim | item.   An oxygen-containing gas (O) having an oxygen partial pressure of 0.00147 MPa or more and 0.0883 MPa or less is used, and the absolute pressure in the gas phase part of the reactor is controlled to 0.098 MPa or more and less than 0.49 MPa. The manufacturing method of the polyphenylene ether of any one of Claims 1-6.