JPS6251295B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polyphenylene ether. For more details, see Manganese ()
It relates to the oxidative polymerization of phenols using salts and dioxime compounds as catalysts. A method of using a manganese salt as a catalyst in producing polyphenylene ether by oxidative polymerization of phenols is known. For example, manganese salt-
Polymers using tertiary amine complexes (Japanese Patent Publication No. 42-3195), manganese salt-amine complexes (US Pat. No. 3,337,501), manganese salt-alkali metal alcoholate catalysts (Japanese Patent Publication No. 47-619), etc. A method for producing phenylene ether has been proposed. Although these methods are sufficiently useful, there is a need to further improve the yield of the polymer by reducing the amount of catalyst used by using a highly active and highly selective catalyst. On the other hand, as an improved method of oxidative polymerization of phenols using cobalt and amine complexes as catalysts, a method has been proposed in which a derivative of 8-hydroxyquinoline and a cobact salt are used as catalysts (Japanese Patent Publication No. 47-31960). Public bulletin). The inventors conducted a follow-up test of this method and found that unless the amount of cobalt salt used relative to the phenols was 10 mol% or more, a polymer with a high degree of polymerization was not produced in the desired reaction time, and the amount of catalyst used was It was found that this method is insufficient to reduce the amount of water and improve the yield of the polymer. That is, the present invention provides manganese () salt and the general formula (In the formula, Q ¹ and Q ² are each a hydrogen atom or a hydrocarbon group.) Or, (In the formula, A is a cyclic hydrocarbon group.) Using a dioxime compound represented by the following as a catalyst,
general formula (However, in the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are each hydrogen, halogen, hydrocarbon group or substituted hydrocarbon group, cyano group, alkoxyl group or phenoxy group, nitro group, imino group or sulfone group) (at least one of which is hydrogen and at least one of which is other than hydrogen) It provides law. According to the present invention, the amount of catalyst required for oxidative polymerization of phenols can be reduced, and the process of removing catalyst residue from the produced polymer can be significantly simplified. That is, the produced polymer is recovered from the reaction solvent substantially free of catalyst, and the reaction solvent is also less likely to be contaminated by manganese catalyst residues. Furthermore, if the conditions are selected, the amount of catalyst used can be reduced, so that both the produced polymer and the catalyst can be precipitated from the reaction solution, and the post-treatment of the reaction solvent can be further simplified. In addition, according to this method, the yield is improved, productivity is high, and the desired degree of polymerization can be easily obtained.
By-products such as diphenoquinone can be suppressed, and defects such as abnormal coloration can be eliminated. A catalyst consisting of a manganese () salt and a dioxime compound can be prepared by combining them in any proportion. Effective preparation uses a solvent in which both the manganese salt and the dioxime compound are at least partially dispersible. Suitable solvents are used, such as methanol, chlorobenzene, toluene and xylene, etc. or mixtures thereof. A more basic inorganic base can be added to this solvent. Generally, manganese () salt and dioxime compound can be combined in any amount, but preferably about 2 times the amount of dioxime per 1 mole of the manganese () salt, particularly preferably 2 to 5 times the amount of dioxime compound. compound is used. Although the structure of the catalyst consisting of manganese () salt and dioxime compound is unknown, it is presumed that it forms a manganese () dioxime complex in solution. Therefore, divalent manganese ions are also included in manganese () salt. The dioxime compound used in the present invention has the general formula (In the formula, Q ¹ and Q ² are each a hydrogen atom or a hydrocarbon group.) Or, (In the formula, A is a cyclic hydrocarbon group.) It is a compound having a structure represented by the following. Specific examples of dioxime compounds used in the present invention include dimethylglyoxime, α-benzinedioxime, glyoxime,
α-Furyl dioxime, 1,2-cyclopentanedione dioxime and ring alkyl substituted products, 3-
Hydroxy 1,2-cyclopentanedione dioxime, 1,2-cyclohexanedione dioxime and ring alkyl substitutes, 1,2-cycloheptanedione dioxime, 1,2-cyclononanedione dioxime, 5,6-dioxo -2,2-dimethylbicyclo[2,2,1]heptane dioxime, 1,2-cyclodecanedione dioxime,
Bicyclo[4,4,0]decane-3,4-dionedioxime, 1,2-cyclododecanedionedioxime, etc. are mentioned. Among these, preferred are α-benzyl dioxime and 1,2-cyclohexanedione dioxime. Manganese () salts used in the present invention include manganese () halides, such as manganese chloride (), manganese bromide (), manganese () iodide (), and other manganese () compounds such as manganese carbonate (), Also included are manganese oxalate (), manganese sulfate (), manganese nitrate (), manganese phosphate (), manganese acetate (), etc., and hydrates of these manganese () compounds. Among these, manganese chloride, manganese sulfate, and manganese acetate are preferably used, and manganese chloride is particularly preferably used. The phenols used in the present invention have the general formula: (However, R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ are hydrogen, halogen, hydrocarbon group or substituted hydrocarbon group, cyano group, alkoxyl group, phenoxy group, nitro group, imino group, or sulfone group, respectively. (at least one of which is hydrogen and at least one of which is other than hydrogen).
Specific examples of R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ include hydrogen, chloro, bromine, iodo, methyl, ethyl, propyl, allyl, phenyl, benzyl, methylbenzyl, chloromethyl, bromomethyl, cyanoethyl, cyano , methoxy, ethoxy, phenoxy,
Examples include nitro, amino, and sulfo. Specifically, the phenols used in the present invention include 2-methylphenol, 3-methylphenol, 2-ethylphenol, 4-methylbenzylphenol, 2,6-dimethylphenol, 2-methylphenol, 2-methylphenol, and 2-methylphenol. Ethylphenol, 2,6-diallylphenol, 2,4-
dibenzylphenol, 2-chlorophenol,
4-bromophenol, 3-iodophenol,
2,3,5-trichlorophenol, 4-bromomethylphenol, 2-methyl-6-bromophenol, 2,4-dimethyl-3-chlorophenol, 3,5-dimethyl-2,4-dichlorophenol, 3 -methoxyphenol, 2,6-dimethoxyphenol, 4-cyanophenol, 2-nitrophenol, 2-aminophenol, 4-hydroxybenzenesulfonic acid and the like.
Each of these can be used alone, or can be used together with other similar phenols to produce a copolymer. Among these, 2,6-dimethylphenol is particularly preferably used. When oxidatively polymerizing phenols, the solvent can form a catalyst solution of phenols, manganese () salts, and dioxime compounds, is inert to phenols, is liquid at the reaction temperature, and is suitable for catalysts. Any known solvent can be used as long as it does not solvate the solvent, such as linear and cyclic aliphatic hydrocarbons, aromatic hydrocarbons, and their hydrocarbon derivatives, such as alcohols, nitro compounds, and halogens. Compounds, ethers, ketones, lactones, sulfone compounds, etc. Specifically, heptane, benzene, toluene, xylene, monochlorobenzene,
Dichlorobenzene, styrene, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, amyl alcohol, n-hexyl alcohol, octyl alcohol, lauryl alcohol, Allyl alcohol, benzyl alcohol, cyclohexyl alcohol, ethylene glycol, trimethylene glycol, butanediol, glycerin, pinacol, β-chloroethanol, p-nitrobenzyl alcohol, nitrobenzene, methylcyclohexane, dichloromethane, dichloroethane, chloroform, diethyl ether, tetrahydrofuran , dioxane, cyclohexane, ethyl acetate, propiolactone, acetonitrile, etc. Among these, suitable solvents include lower alcohols such as methanol, benzene, toluene,
Mixtures with aromatic hydrocarbons such as xylene can be mentioned. The lower alcohol may be used as a mixture in a weight percentage of 5 to 98% with respect to the aromatic hydrocarbon. The proportion of phenols to solvent can vary widely. Generally, the weight percentage can be changed by 5 to 70%, more preferably 10 to 50%. The oxidative polymerization reaction of phenols can be carried out by using smaller amounts of manganese () salt and dioxime compound catalysts than in conventional methods.The ratio of manganese () salt and dioxime compound catalysts to phenols is is approximately 1/50 in molar ratio
Can be used below. Preferably about 1/
It is used within the range of 100 to about 1/5000. The oxidative polymerization of phenols promoted by the catalysts of manganese salts and dioxime compounds can be carried out very efficiently in the presence of a solvent containing a basic substance. Examples of basic substances include metals, hydroxides and their oxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, barium hydroxide, lithium methoxy, sodium methoxide, potassium methoxy Examples include metal alkoxides such as carbon dioxide, totium methoxide, and sodium ethoxide, and metal phenoxides such as lithium phenoxide, potassium phenoxide, and sodium phenoxide. Although the amount of the basic substance to be used can be easily determined depending on practice, it is preferable that the amount of the basic substance to be used is about 2 mol % or more relative to the phenols. More preferably, it is 4 mol% or more. In oxidatively polymerizing phenols according to the method of the present invention, combinations of primary, secondary, and tertiary amines may be used. If the amine is present, the resulting polymer will be lighter in color and the yield can be improved. Useful amines include mono- and dialkylamines containing from 1 to 10 carbon atoms, such as n-butylamine, n-hexylamine, di-n-butylamine, di-n-hexylamine, and the like. In addition, alkanolamines and polyamines such as monoethanolamine, diethanolamine, and triethanolamine,
Examples include piperazine and morpholine. The amount of amine used in the practice of this invention can vary widely, but can generally be added in a proportion of 0.05 to 2 mole percent relative to the phenols. Oxygen gas or air is used as oxygen. When air is used, the reaction rate is low, but it is still usable. The blowing method is usually used to introduce the gas into the reaction mixture, but when using gas with a high oxygen concentration and maintaining good gas-liquid contact by means such as strong stirring or liquid circulation, the remainder of the introduced gas is removed from the system. There is no need to extract the liquid at any time, and there is no need to use a blowing method. Furthermore, in the present invention, there is a possibility that a secondary reaction of the produced polymer occurs due to the coexistence of oxygen. This secondary reaction is thought to be due to the accumulation of peroxide groups or hydroperoxide groups, so
In this way, a method of coexisting a general peroxide deactivator for the purpose of preventing secondary reactions can also be adopted. The reaction temperature may be within a range where the reaction medium remains liquid, but it is usually 100°C to avoid side reactions.
The temperature below is preferably 10 to 60°C. The reaction pressure is generally normal pressure. After the reaction is complete, the general polymer recovery method is to bring the resulting reaction mixture into contact with a non-solvent for the produced polyphenylene ether to precipitate and separate the polyphenylene ether. If the amount is large, the polymer may precipitate as the polymerization progresses. Next, the method of the present invention will be explained with reference to Examples.
These are illustrative and not limiting, and they can be modified as appropriate within the scope of the present invention. Example 1 0.25 mol of 2,6-xylenol was dissolved in 61.0 g of xylene and 2,6-xylenol was dissolved in 61.0 g of methanol using a 0.5 mm four-necked flask equipped with a thermometer, a reflux condenser, a gas blowing tube, and a stirrer. Manganese chloride 0.067 mol% based on 6-xylenol,
1,2-cyclohexanedione dioxime 0.134
A manganese salt and an oxine compound catalyst prepared at a ratio of 6 mol % and 6 mol % of sodium hydroxide were added, and the mixture was stirred at 30°C while introducing oxygen at a flow rate of 0.5 Nl/min・ml. Polymerized. At 3 and 5 hours after the start of the reaction, the reactant was poured into efficiently stirred methanol containing a small amount of hydrochloric acid, the precipitate formed was separated, further washed with methanol, and then dried to give a white color. A powdered polymer was obtained. The intrinsic viscosity [η] of each polymer measured in chloroform at 25°C was 0.61 and 0.75. The shedding rate of the total polymer was 96%. The manganese content in the polymer was 10 ppm or less. The infrared spectrum showed characteristic absorption of polyphenylene ether type polymers. Examples 2 to 4 Using the same reactor as in Example 1, oxidative polymerization was performed by changing the type and amount of manganese () salt and dioxime compound, the type and amount of basic substance, and the type of solvent. Konatsuta. The results are shown in Table 1 together with Example 1. Comparative Examples 1-2 Oxidative polymerization was carried out in a system not containing a dioxime compound and in a system using a cobalt salt in place of the manganese salt, using the same reactor as in the example and performing the same operation. The results are shown in Table 1 together with Examples.

【table】

【table】

Claims (1)

[Claims] 1. Manganese () salt and general formula (In the formula, Q ¹ and Q ² are each hydrogen or a hydrocarbon group.) Or, (In the formula, A is a cyclic hydrocarbon group.) Using a dioxime compound represented by the following as a catalyst,
general formula (In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ are each hydrogen, halogen, hydrocarbon group or substituted hydrocarbon group, cyano group, alkoxyl group or phenoxy group, nitro group, imino group or sulfone group) (at least one of which is hydrogen and at least one of which is other than hydrogen) is oxidatively polymerized. . 2. The method for producing polyphenylene ether according to claim 1, characterized in that 2 to 5 mol of the dioxime compound is used per 1 mol of manganese () salt. 3. The method for producing polyphenylene ether according to claim 1 or 2, wherein the dioxime compound is 1,2-cyclohexadione dioxime or α-benzyldioxime. 4. The method for producing polyphenylene ether according to claim 1, wherein the manganese () salt is manganese chloride, manganese sulfate, or manganese acetate. 5 The addition ratio of catalyst to phenols is 1/
The method for producing polyphenylene ether according to claim 1, characterized in that the amount is 50 mol or less.