JPH0513964B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing polyphenylene ether with improved water resistance using a highly active copper catalyst. More specifically, copper compounds, N, N, N',
In the presence of a highly polymerizable catalyst containing N'-tetramethyl-1,3-diamino (unsubstituted or substituted) propane (hereinafter abbreviated as 1,3-diamine) and a bromine compound or a chlorine compound, methanol and/or Alternatively, the present invention relates to a method for producing polyphenylene ether by oxidative polymerization of a phenolic compound in a reaction solvent containing ethanol. [Prior art] Many combinations of copper compounds and various amines have been proposed as polymerization catalysts for producing polyphenylene ether through oxidative polymerization of phenolic compounds since the proposal in Japanese Patent Publication No. 18692/1973. It has been. That is, various proposals have been made regarding the types of copper compounds and halides that work together with them, as well as various proposals regarding amines, such as whether to use primary amines, secondary or tertiary amines, or whether to use monoamines, di- or polyamines. ing. For example, in the old days, USP3306875,
In Nos. 3344116 and 3432466, copper compounds and N, N,
A method using a tetraalkyl-type catalyst system such as N',N'-tetramethyl-1,3-butanediamine has been proposed; Publication No. 52-17075 and No. 52-17076) have also been proposed, but these have not been sufficient in terms of catalytic activity. Recently, copper amine complexes consisting of combinations with N,N'-di-t-butylethylenediamine, etc., such as copper ions, bromide ions, N,
N'-di-t-butylethylenediamine and N-
It has been reported that combinations of tertiary amines such as methylpyrrolidine have relatively high activity (Special Publications No. 58
−53012). However, the polymer produced using this catalyst system has poor color, and the composition with styrenic resins such as rubber-modified polystyrene has low impact resistance and poor thermal stability, making it impractical. It became clear that this catalyst system was combined with a secondary monoamine such as di-n-butylamine, and it became practical for the first time (Tokuko Sho).
59-23332). Furthermore, in this catalyst system, a production method in which the molar ratio of bromide ions to the raw material phenolic compound is 1:35 or more (Japanese Unexamined Patent Application Publication No. 1983-1999)
74124), a method characterized by using a mixture of cuprous salt and cupric salt as the copper compound (JP-A-59-131627), and a catalyst system using dimethylamine as the secondary monoamine (JP-A-59-131627). Tokuko Showa 60-
54327) etc. are also known. [Problems to be Solved by the Invention] However, these conventionally known catalysts did not have sufficient improvement in water resistance and had insufficient polymerization activity, particularly in continuous polymerization. One of the reasons for this is that N,N'-di-t-butylethylenediamine is produced during the polymerization process, as stated in lines 28 to 31 of the left column on page 3 of the specification of JP-A-59-196318. It is assumed that this is related to the fact that they are often very easily consumed. In any case, the catalyst components are hydrolyzed by the reaction product water that is produced as a by-product during the oxidative polymerization of phenols, and the metal components become hydroxides and exit the reaction system, resulting in a decrease in catalytic activity. Therefore, there was a need to develop a catalyst that would not lose its activity even in the presence of reaction product water in order to achieve high activation of the catalyst. [Means for Solving the Problems] As a result of intensive studies on the production method of polyphenylene ether under the above-mentioned situation, the present inventors found that polyphenylene ether consists of a copper compound, a specific diamine, and a bromine compound or a chlorine compound. It was discovered that the catalyst system has excellent water resistance and high polymerization activity in a reaction solvent containing methanol and/or ethanol, and based on this knowledge, the present invention was completed. That is, the present invention is characterized in that a method for producing polyphenylene ether uses a catalyst containing a copper compound, 1,3-diamine, and a bromine compound or a chlorine compound, and a reaction solvent containing methanol and/or ethanol. It is something to do. In carrying out the present invention, the copper compound can be a cuprous salt, a cupric salt, or a mixture thereof. Although any cuprous or cupric compound can be used, soluble copper salts are preferred from the standpoint of economy and availability of the compound. Compounds of normally insoluble copper (cupric and cuprous) may also be used. Cupric compounds that can be used in the catalyst of the present invention include cupric halides such as cupric chloride or cupric bromide, cupric sulfate, cupric nitrate, cupric acetate,
Examples include cupric azide and cupric toluate. Examples of cuprous compounds that can be used are:
These include cuprous chloride, cuprous bromide, cuprous sulfate, cuprous nitrate, cuprous azide, cuprous acetate, cuprous butyrate, cuprous toluate, and the like. Among these, preferred cuprous and cupric compounds are cuprous chloride, cupric chloride, cuprous bromide, and cupric bromide. Further, these copper salts may be synthesized from oxides, carbonates, hydroxides, etc. and halogen or hydrogen halide at the time of use. The amount of the copper compound to be used is not particularly limited, but may be appropriately used in the range of 0.005 gram atom to 0.5 gram atom, preferably 0.01 gram atom to 0.0 gram atom, of copper per 100 moles of the phenolic compound. This shows that the copper compound can be used at an extremely low concentration, and in other words, the present invention shows that the activity per copper catalyst is so high that it has not been found in the prior art. One of the important points in the present invention is that N, N, N',
The point is that N'-tetramethyl-1,3-diamino (unsubstituted or substituted) propane is used as an essential component. N,N,N',N',-tetramethyl- of the present invention
1,3-diamino unsubstituted propane means N,N,
N',N'-tetramethyl-1,3-diaminopropane is N,N,N',N'-tetramethyl-1,3-diamino substituted propane.
N,N',N'-tetramethyl-1,3-diaminopropane having a substituent (side chain) on its main chain. In addition, as the substituent, a lower alkyl group is preferable, and monosubstitution is preferable. Next, the N,N,N',N'-tetramethyl-1,
Preferred examples of 3-diamino substituted propane include N,N,N',N'-tetramethyl-1,3-
Diamino-1-methyl-propane, N,N,N',
N'-tetramethyl-1,3-diamino-2-methyl-propane, N,N,N',N'-tetramethyl-1,3-diamino-1-ethyl-propane,
Examples include N,N,N',N'-tetramethyl-1,3-diamino-2-ethyl-propane. Among the above, N,N,N',N'-tetramethyl-1,3-diaminopropane and N,N,N',N'-tetramethyl-1,3-diamino-1-methyl-propane are particularly preferable. While the conventional highly active amine N,N'-di-t-butylethylenediamine shows some activity only when used in combination with other secondary and tertiary amines, the 1,3-diamine of the present invention In addition to being effective as a tertiary amine, it also works extremely well as a chelating agent, so its major feature is that it exhibits high activity even in the absence of other secondary or tertiary amines. Note that the present invention does not exclude the use of other secondary and tertiary amino acids in combination, and the combined use may produce effects other than activity. As shown in the comparative example below,
Although it is not clear why the 1,3-diamine of the present invention exhibits higher activity compared to N,N,N',N'-tetramethylethylenediamine and N,N'-di-t-butylethylenediamine, Steric regulation in the polymerization system seems to be involved. The amount of 1,3-diamine used in the present invention is not particularly limited, but it is used in an amount of about 0.1 to 10 mol, preferably about 1 to 6 mol, per 100 mol of the phenolic compound. In the present invention, it is essential to use 1,3-diamine in combination with a bromine compound or a chlorine compound, and high activity cannot be obtained even if it is used in combination with an iodine compound. In particular, when the amount of copper compound used is small, even polymerization does not occur with iodine compounds. The bromine compound or chlorine compound is not particularly limited, and any conventionally known bromine compound or chlorine compound can be used. For example, hydrogen bromine, hydrogen chloride, sodium bromide, sodium chloride, potassium bromide, potassium chloride, cupric bromide, cuprous bromide, cuprous chloride, cupric chloride, etc. can be used. Particularly preferred are hydrogen chloride and hydrogen bromide. The amount of bromine compound or chlorine compound is not particularly limited, but it is 0.5 to 20 mol, preferably 1 to 10 mol per mol of copper.
The mole level is used. Preparation of the catalyst can be carried out using a vehicle such as methanol, ethanol, or a mixture of methanol and ethanol. Furthermore, benzene, toluene,
Aromatic hydrocarbons such as xylene and ethylbenzene may coexist, and a phenolic compound monomer may also coexist. The objective can be achieved by methods commonly known to those skilled in the art, provided that care is taken to dissolve the copper compound. It may also be prepared in the atmosphere. The phenolic compound used in the method of the present invention has the general formula () (In the formula, R ₁ is a hydrocarbon group having 1 to 4 carbon atoms, and R ₂ and R ₃ are halogen, a hydrocarbon group having 1 to 4 carbon atoms, or a substituted unsubstituted phenyl group.) Examples of such substances 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-promophenol, 2-methyl -6-n-butylphenol,
Examples thereof include 2,6-di-n-propylphenol, 2-ethyl-6-chlorophenol, 2,6-diphenylphenol, 2,-methyl-6-tolylphenol, and 2,6-ditolylphenol. These compounds may be used alone or in combination of two or more. Further, there is no practical problem even if a small amount of ortho-cresol, m-cresol, para-cresol, 2,4-dimethylphenol, 2-ethylphenol, etc. are included. Among these phenolic compounds, especially 2,
6-dimethylphenol is important. The ratio of the phenolic compound to the medium can be selected within a wide range, but usually the concentration of the phenolic compound in the reaction solution is 70% by weight or less, preferably 10 to 40% by weight, more preferably 20 to 35% by weight. It is. The reaction solvent used in the method of the present invention contains methanol or ethanol. Methanol or ethanol is usually mixed with other vehicles and used as a reaction solvent. There are no particular restrictions on the carrier that can be used for mixing, as long as it is less likely to be oxidized than the phenolic compound to be oxidized and is not reactive to various radicals that are thought to be generated intermediately in the reaction process. However, it is preferable to use one that dissolves the phenolic compound and some or all of the catalyst mixture. Examples of such substances include aromatic hydrocarbons such as benzene, toluene, and xylene, chloroform, 1,2-dichloroethane, trichloroethane, chlorobenzene,
Halogenated hydrocarbons such as dichlorobenzene, nitro compounds such as nitrobenzene, etc. can be used as good carriers for the polymer. Examples of poor solvents for polymers include alcohols such as propanol, butanol, benzyl alcohol, and cyclohexanol; aliphatic hydrocarbons such as pentane, hexane, heptane, cyclohexane, and cycloheptane;
Ketones such as acetone and methyl ethyl ketone,
Examples include esters such as ethyl acetate and ethyl formate, ethers such as tetrahydrofuran and diethyl ether, and amides such as dimethylformamide. Methanol or ethanol can be used in combination with one or more of these good-capacity media and, if necessary, with one or more poor-capacity media. The ratio can be selected within a wide range. The content of methanol and/or ethanol in the reaction solvent is preferably 1 to 80% by weight, more preferably 5 to 75% by weight.
% by weight, optimally between 10 and 50% by weight. Therefore, generally the total concentration of the good capacity medium and the poor capacity medium other than methanol and/or ethanol in the reaction solvent is 99 to 20% by weight, more preferably 95 to 20% by weight.
25% by weight, optimally 90-50% by weight. The ratio of poor carrier medium to good carrier medium is not very strict and is generally 0 to 60% by weight, more preferably 0 to 50% by weight.
is used. By selecting the combination ratio of a good capacity medium for this polymer and a poor capacity medium other than methanol and/or ethanol, it can also be a solution polymerization method.
If the ratio of poor medium is increased, the method becomes a precipitation polymerization method in which the polymer precipitates as particles in the reaction solvent as the reaction progresses. In summary, in the present invention, it is important to use a solvent containing methanol or ethanol, and conventional aromatic solvents, such as combinations of propanol and aromatic solvents, do not exhibit high activity. In the present invention, the reason why solvents containing methanol or ethanol exhibit extremely high activity is not clear, but it is believed that methanol and ethanol are involved in preventing phase separation of polymerized water and coordinating it to catalytically active species. Seem. The present invention is applicable to batch polymerization, continuous polymerization, solution polymerization, precipitation polymerization, and the like. Particularly preferred is a precipitation polymerization method in which the polymer is precipitated as particles in the reaction solvent as the reaction progresses. A quaternary ammonium salt or a surfactant may be added to the reaction system for the purpose of increasing the reaction rate, controlling the particle size of the polymer, or improving phase separation between solvents. Regarding the reaction temperature, if it is too low, the reaction will be difficult to proceed, and if it is too high, the catalyst may be deactivated, so it is in the range of 0 to 80°C, preferably 10 to 60°C. Oxygen in the oxidative polymerization of the present invention includes pure oxygen,
A mixture of an inert gas such as nitrogen in any proportion, air, etc. can be used. The pressure can be normal pressure or increased pressure. There are no particular restrictions on the post-treatment method after the reaction is completed. Usually an acid such as hydrochloric acid or acetic acid or ethylenediaminetetraacetate acid (EDTA),
After deactivating the catalyst by adding a chelating agent such as nitrilopolyacetate acid to the reaction solution, the resulting polymer is separated, washed with a solvent that does not dissolve the polymer such as methanol, and then dried. Polyphenylene ether can be recovered by simple operations. [Effects of the Invention] In the method of the present invention, since a highly active catalyst with improved water resistance is used, the amount of catalyst used can be reduced. The amount of solvent is small, resulting in reduced solvent recovery costs. In addition, the catalyst removal process can be simplified, such as the equipment for removing the catalyst being downsized. In addition, the color tone of the obtained polymer and the Izot impact strength when compounded with rubber-reinforced polystyrene and the like are excellent.
It has now become possible to provide polyphenylene resins and knitted polyphenylene resins of unprecedented high quality. [Examples] Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way. In addition, when measuring ηsp/c, the polymer was measured at 0.5W/V%.
The test was conducted using the Ubbelohde viscosity system as a chloroform solution at 30°C. Example 1 Using a 100 c.c. glass reactor, the catalytic activity was examined based on the viscosity reached after a certain polymerization time. That is, 0.00205gr (0.0144mmol) of fine powdered cuprous oxide and 0.0275gr (0.264mmol) of 35% hydrochloric acid were added, and after completely dissolving, 6.3gr of methanol was added.
Add to this 0.1492g of N,N,N',N'-tetramethyl-1,3-diaminopropane prepared in a separate container.
(1.15 mmol) and 6.3 gr of methanol were added. Thereafter, 7.0 gr (57.4 mmol) of 2,6-dimethylphenol and 12.6 gr of n-butanol dissolved in 37.8 gr of toluene were added. The reaction solvent used was 63gr, and its composition was toluene:n
-Butanol:methanol weight ratio: 60:20:20
It was hot. The concentration of 2,6-dimethylphenol is 10% by weight, and the amount of copper is 0.05 gram atom per 100 moles of 2,6-dimethylphenol.
Thereafter, 1.03 gr of water equivalent to the water produced by the reaction was added, and the reaction was carried out at 30° C. for 3.5 hours while stirring and supplying oxygen. The reaction liquid had changed to a yellow-white liquid containing slurry. Methanol in an amount 5 times the volume of the reaction solution was added, and the resulting polymer was filtered, washed, and dried, and the viscosity of the polymer was 0.53. Examples 2 to 6, Comparative Examples 1 to 3 The amount of copper used, the type and amount of 1,3-diamine, the type of halogen, etc. were changed as shown in Table 1,
Polymerization was carried out under the same conditions as in Example 1. The results are shown in Table 1.

【table】

[Table] **: Only a small amount of polymer was obtained.
Examples 7, 8, 9 The reaction solvent composition of Example 1 was changed as shown in Table 2, and polymerization was carried out under the same conditions as in Example 1 to obtain the results shown in Table 2. Example 10 The same procedure as in Example 7 was carried out except that the 1,3-diamine in Example 7 was changed as shown in Table 2. The results are shown in Table 2. Example 11 The reaction was carried out in the same manner as in Example 10, except that the reaction solvent composition was changed as shown in Table 2. The results are shown in Table 2.

[Table] Example 12 The procedure was carried out in the same manner as in Example 1, except that 63 g of a mixture of toluene and ethanol was used as the reaction solvent instead of the reaction solvent (mixture of toluene, n-butanol, and methanol) in Example 1. Table 3 The results were obtained. Comparative Examples 4 to 6 The same procedure as in Example 12 was performed except that n-propanol, i-propanol, and n-butanol were used in place of ethanol in Example 12, and the results shown in Table 3 were obtained.

[Table] Examples 13, 14 The same procedure as in Example 1 was carried out, except that 63 g of a mixture of toluene and methanol was used as the reaction solvent instead of the reaction solvent (a mixture of toluene, n-butanol, and methanol) in Example 1. The results shown in Table 4 were obtained.

[Table] Example 15 Polymerization was carried out using a continuous polymerization reactor consisting of three complete mixing tanks for continuous polymerization activity and polymer quality evaluation. The first reactor has a capacity of 1.5 and is equipped with a circulation pump. The second reactor and the third reactor are equipped with a stirrer and have capacities of 3.7 and 1.5, respectively. A catalyst solution was prepared by dissolving cuprous oxide in 48% hydrogen bromide water, adding methanol, and then adding N,N,N',N'-toteramethyl-1,3-diaminopropane and methanol. A monomer liquid was prepared by dissolving 2,6-dimethylphenol in toluene and n-butanol. Each was prepared under air. The catalyst liquid and monomer liquid were fed to the first reactor at a constant rate. Based on the amounts of the catalyst liquid and monomer liquid fed, the composition of the reaction raw material liquid is as follows. The weight ratio of the solvent used was 2,6-dimethylphenol at a concentration of 20% by weight: toluene:n-butanol:methanol=60:20:20. Per 100 moles of 2,6-silenol, 0.05 gram atom of copper, 0.46 gram atom of Br ion, N,N,
N',N'-tetramethyl-1,3-diaminopropane was in a 2 molar proportion. Also, 2,6-dimethylphenol is 224g/Hr
was supplied at a rate of In the first reactor, the reaction solution was vigorously circulated using a circulation pump, and oxygen was passed through the reactor. The internal temperature was controlled to be 30°C. The head pressure from the first reactor
The reaction solution sent to the reactor was homogeneous. The second reactor was kept at 25°C by flowing oxygen gas at a rate of 500 ml/min while stirring vigorously with a stirrer.
The polymer precipitates out, but is evenly distributed throughout the reactor by stirring. As an overflow from the second reactor, the reaction solution containing polymer particles enters the third reactor. While controlling the temperature of the third reactor at 25°C, oxygen gas was flowed at a rate of 200 ml/min while stirring with a stirrer. A reaction solution containing a polymer was continuously taken out from the third reactor as an overflow. Methanol was added to the yellow-white reaction liquid containing the slurry, and the mixture was filtered. It was thoroughly purified and washed using a mixed solution (toluene, butanol, and methanol) and diluted hydrochloric acid. The viscosity (ηsp/c) of the polymer obtained after drying was within the range of 0.52±0.03, and stable operation was possible for a long period of time.

Claims (1)

[Claims] 1. In the production of polyphenylene ether by oxidative polymerization of a phenolic compound using a catalyst,
Copper compound, N,N,N',N'-tetramethyl-1,
A method for producing polyphenylene ether, which comprises using a catalyst containing 3-diamino (unsubstituted or substituted) propane and a bromine compound or a chlorine compound, and a reaction solvent containing methanol and/or ethanol.