JPH035412B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a poly(dialkoxyphenylene) having two alkoxy groups having different numbers of carbon atoms on a benzene ring, and a method for producing the same. Polyphenylene polymers, which have linear phenylene groups in their main chains, have excellent heat resistance and have long been expected to be used as metal substitute materials for aerospace applications or engineering plastics. It is attracting attention as a conductive polymer through treatments such as doping. However, polyphenylene polymers have generally been unsatisfactory as materials for molding processing due to their infusibility and insolubility. For example, polyphenylene

[Formula] has good heat resistance with a decomposition temperature of 550℃, but it is infusible and insoluble and has poor processability, so the characteristics of the polymer cannot be utilized, and powder metallurgy methods are slightly required as a processing method. It is only suggested. As a result of searching for a new polyphenylene material with excellent heat resistance, the present invention succeeded in producing poly(dialkoxyphenylene) with excellent heat resistance and processability. It has recently been reported that unsubstituted polyphenylene can be given extremely high conductivity as an organic compound through doping, etc.
In the polymer compounds according to the present invention, the electron density on the aromatic ring is improved due to the presence of an alkoxy substituent, so high conductivity can be imparted by similar doping. The poly(dialkoxyphenylene) proposed by the present invention can be produced by polymerizing paradylalkoxybenzene represented by general formula (2). The raw material paradialkoxybenzene is
For example, when one of the alkoxy groups is a methoxy group, para-methoxyalkoxybenzene can be used to convert the hydroxyl group of hydroquinone monomethyl ether used as a polymerization inhibitor into hydrocarbon-based, ether-based,
In a ketone-based solvent, using a base such as alkali carbonate or alkali hydroxide as a deoxidizing agent, and using an alkylating agent such as dialkyl sulfuric acid, alkyl paratoluenesulfonate, alkyl bromide, alkyl iodide, or alkyl chloride. By alkylation, it can be produced easily and at low cost. This method for producing methoxyalkoxybenzene is similar to the method for producing dialkoxybenzene from hydroquinone, but since the raw material hydroquinone monomethyl ether is more stable under basic conditions than hydroquinone, methoxyalkoxybenzene Since benzene can be obtained with good yield and purity, the production of polymer compounds using benzene as a raw material is extremely advantageous industrially. Polymerization of dialkoxybenzene is also possible by a known method for producing polyphenylene, but this method has a low yield, and moreover, the halogen atom due to the catalyst is introduced into the aromatic nucleus of the main chain, or the reaction The heat resistance of the polymer produced is poor due to factors such as the change of alkoxy groups into hydroxyl groups due to the elimination of alkyl groups during processing and processing, and it is impossible to create a product that can be used as a polymeric material for molding. I can't. As a result of intensive research aimed at improving these drawbacks, the present inventor discovered the polymerization method described in the present invention, making it possible to provide a new and useful polymeric material. In the method of the present invention, dialkoxybenzene represented by general formula (2) is polymerized in an inert solvent in the presence of a Lewis acid and an oxidizing agent under reduced pressure. As the Lewis acid used in the method of the present invention, any one used in cationic polymerization or coordination polymerization can be suitably used. Such Lewis acids include anhydrous aluminum chloride, anhydrous ferric chloride, anhydrous titanium chloride (N),
Anhydrous stannic chloride, anhydrous molybdenum chloride, anhydrous tungsten chloride, anhydrous antimony (V) chloride, boron fluoride, boron fluoride etherate, and the like are used, and anhydrous aluminum chloride and anhydrous ferric chloride are particularly preferred. It is also effective to use other halides such as metal bromides corresponding to the metal chlorides. Since the production reaction of the polymer compound of the present invention proceeds in an oxidative manner, it is necessary to coexist an oxidizing agent in addition to the Lewis acid. Oxidizing agents include high valence transition metal compounds, such as chlorides such as cupric chloride (anhydrous and hydrated), ferric chloride, tin chloride, molybdenum chloride, tungsten chloride, or other corresponding halogens. oxides such as manganese dioxide, lead dioxide, and stannic oxide, as well as oxoacid salts such as permanganate, organic oxidizing agents such as chloranil, benzoquinone, and naphthoquinone, peracetic acid, perbenzoic acid, and methachloroperbenzoic acid. Organic peracids such as aromatic acid or hydrogen peroxide are used, and among them, anhydrous or hydrated cupric chloride, ferric chloride, etc. are preferable. Among these oxidizing agents, when using oxidizing agents such as cupric chloride, which have low solubility in the reaction solvent and do not exhibit sufficient effects, it is recommended to use oxygen in the air or use a promoter. is effective. Oxidation cocatalysts used in this manner include carboxylic acid salts of cobalt (), such as cobalt () acetate, cobalt () benzoate, cobalt () oxalate, and cobalt () such as cobalt () acetylacenate. Complex compounds of () are effective, but manganese (), chromium ()
Similar compounds are also effective. By using such a co-catalyst, the poly(dialkoxyphenylene) which is the object of the present invention can be produced in extremely high yield. The inert solvent used in the method of the present invention is
Any organic solvent that is used in a normal Friedel-Crafts reaction and is inert to Lewis acids and aryl cations can be used, but in particular, nitroalkanes such as nitromethane and nitropropane,
Aromatic nitro compounds such as nitrobenzene, O-dichlorobenzene, etc. are suitable. The above Lewis acids, oxidizing agents, oxidation cocatalysts and solvents may be used in various combinations without particular limitation, but particularly preferred examples include anhydrous aluminum chloride, sulfuric acid chloride in nitrobenzene, etc. These include the use of copper and cobalt based promoters, or the use of ferric chloride in nitroalkanes. The amount of solvent used in the reaction is usually 1 to 20 parts by weight per 1 part by weight of dialkoxybenzene.
This amount of solvent can be varied depending on the solubility of the dialkoxybenzene in the solvent and economic considerations. The amount of Lewis acid used in the present invention is 1 to 5 mol per 1 mol of dialkoxybenzene, but it also varies depending on the solubility or activity of the Lewis acid used in the solvent. For example, when aluminum chloride is used, a good yield can be obtained with equimolar amounts of alkoxybenzene, but when titanium chloride or ferric chloride is used, an excess amount of 2 to 2.5 moles is desirable. In addition, when one molecule of dialkoxybenzene is introduced into the polymer chain, the oxidizing agent
At least 2 equivalents of oxidizing agent are required, as oxidizing agent is lost to HCl. In other words, when using ferric chloride or cupric chloride, 2 moles of oxidizing agent are required per 1 mole of dialkoxybenzene, but oxidizing agents that are poorly soluble in solvents such as cupric chloride Even when using ferric chloride, which is easily soluble in a solvent, it is effective to increase the amount appropriately when it is desired to complete the reaction in a shorter time. The amount to be increased is determined primarily for operational or economic reasons, but generally it may be increased up to 5 equivalents. However, if increasing the amount of oxidizing agent is not desirable,
This can also be avoided by using a small amount of cocatalyst, such as 1/200 to 1/10 per mole of dialkoxybenzene. In other words, in a system in which aluminum chloride is selected as the Lewis acid and cupric chloride is selected as the oxidizing agent, the yield is 20 to 30% when no cocatalyst is used. When 1/20 mole of is used per mole of dialkoxybenzene, the yield increases to 50-60%. The use of this cocatalyst has the advantage of dramatically increasing the yield with a small amount; however, on the other hand, it may cause the formation of phenolic hydroxyl groups due to the elimination of alkyl groups from alkoxy groups during the polymerization reaction process. I understand. This side reaction is only slightly observed in the infrared spectrum, and the thermal, electrical, or mechanical properties are not inferior in any way to those without cocatalysts; If the presence of phenolic hydroxyl groups in the poly(dialkoxy) group poses a problem, after isolation of the polymer, the poly(dialkoxy phenylene). Preferred reaction conditions for the polymerization reaction of the present invention are to reduce the pressure to 10 mmHg so that the generated hydrogen chloride can be removed from the system. As the internal pressure during the reaction approaches normal pressure, substitution introduction of halogen atoms derived from the catalyst onto aromatic rings and elimination of alkyl groups from alkoxy groups become more likely to occur.
Even if it is lower than mmHg, the effect does not change significantly. Due to operational issues, a range of 10 mmHg to 40 mmHg is usually appropriate. The reaction temperature can be between -30°C and 100°C, but increasing the reaction temperature is not advantageous because it causes substitution of halogen derived from the catalyst onto the aromatic ring and elimination of the alkyl group. On the other hand, if the reaction is carried out at too low a temperature, the solubility of dialkoxybenzene in the solvent will decrease and the reaction rate will become slow, which is not advantageous. Therefore preferably
It is most advantageous in terms of operation to carry out the reaction at an angle of 0° to 40°, particularly around room temperature. The reaction time varies depending on the type of dialkoxybenzene, but the reaction is considered to be completed when hydrogen chloride gas is no longer generated.
The time required for this is 30 minutes to 2 hours. It is possible to continue the reaction for a long time, but this is not particularly advantageous. The poly(dialkoxyphenylene) thus obtained has a melting point as shown in Table 1 without impairing the heat resistance characteristic of polyphenylene polymers, and has excellent processability. The melting point shows a specific value depending on the chain length of the linear alkyl moiety forming the alkoxy group. Furthermore, by increasing the chain length of the straight-chain alkyl group in the alkoxy group, it becomes soluble in general-purpose organic solvents such as toluene, dimethylformamide, etc., and film formation by the casting method becomes possible. All of these features are not found in conventional polyphenylene-based polymer compounds, and the poly(dialkoxyphenylene) provided by the present invention can be said to be an extremely useful polymer material. The present invention will be explained below with reference to Examples. Example 1 6.3 g of P-methoxyethoxybenzene dissolved in 50 ml of nitromethane was added to 50 ml of nitromethane in which 19.4 g of anhydrous ferric chloride had been dissolved in advance, and the internal pressure in the reactor was 20 to 40 mmHg and the internal temperature was 20 to 35 mmHg. Drop carefully to maintain temperature. After leaving it for 1 hour, drain the contents with methanol.
Pour into 500ml and stir at room temperature for 1 hour.
The insoluble matter is taken out and washed three times with 300 ml of 3N hydrochloric acid under heating and stirring, and then washed with 500 ml of water. Then, it was dried in a vacuum dryer at 100℃ for 6 hours.
3.96 g of poly(methoxyethoxyphenylene) is obtained as a light brown powder. Melting point, thermogravimetric analysis (TGA)
The results, viscosity measurement results and elemental analysis results are shown in the table. Figure 1 shows the infrared absorption spectrum (IR chart) of this polymer. Example 2 13.4 g of anhydrous aluminum chloride, anhydrous cupric chloride
13.5g, cobalt() acetylacetonate
Stir 1.28g well in 50ml of nitrobenzene, then add 15.2g of methoxyethoxybenzene dissolved in 50ml of nitrobenzene under reduced pressure until the internal pressure
Drop while adjusting so that the internal temperature is 20-35mmHg and 20-35°. After finishing, leave as it is for 1 hour, pour the contents into 500 ml of methanol, and stir at room temperature for 1 hour. After removing the insoluble matter, it is washed three times with 300 ml of 3N hydrochloric acid under heating and stirring, and then washed with 500 ml of water. Dry under reduced pressure in a vacuum dryer at 100° C. for 6 hours to obtain 3.64 g of poly(methoxyethoxyphenylene) as a light brown powder. The melting point, TGA analysis results, viscosity measurement results, and elemental analysis results are shown in the table. Figure 2 shows the IR chart of this polymer. This chart is 3400cm ^-1
The result was almost identical to that of Example 1, except for a slight absorption attributed to hydroxyl groups in the vicinity. Example 3 The reaction was carried out in the same manner as in Example 1 except that 6.8 g of P-methoxypropoxybenzene was used instead of 6.3 g of P-methoxyethoxybenzene to obtain 5.82 g of a light brown polymer. The melting point, TGA analysis results, viscosity measurement results, and elemental analysis results are shown in the table. Figure 3 shows the IR chart of the polymer. Example 4 The reaction was carried out in the same manner as in Example 1, except that 7.4 g of P-methoxybutoxybenzene was used instead of 6.3 g of P-methoxyethoxybenzene, to obtain 5.0 g of a light brown polymer. Table 1 shows the melting point, TGA analysis results, viscosity measurement results, and elemental analysis results. The IR chart of this polymer is shown in Figure 4. The properties of the polymers obtained in Examples 1 to 4 are summarized. Each item in the table will be explained below. Melting point: The value is as measured by a melting point measuring device and has not been corrected. TGA analysis results: Approximately 5 mg of sample was taken and measured in air at a heating rate of 1°C/min. The 5% weight loss temperature is shown in the upper row, and the 50% weight loss temperature is shown in the lower row. Elemental analysis results: No chlorine atoms were detected in any of the samples. Observed values are shown in the upper row, and calculated values are shown in parentheses in the lower row. Intrinsic viscosity: Sample concentration (C) 0.1 to 0.6 (g/100
ml) in concentrated sulfuric acid, the resulting ηsp/
The intrinsic viscosity [η] was determined by extrapolating the curve c to C→0.

【table】 [Brief explanation of the drawing]

1, 2, 3 and 4 are Example 1, respectively.
2 shows the infrared absorption spectra of the polymers of the present invention obtained in Sections 2, 3, and 4.

Claims (1)

[Claims] 1. Substantially the formula (In the formula, R and R' are different numbers of carbon atoms from 1 to 5.
represents an alkyl group. ) is a repeating unit of poly(dialkoxyphenylene). 2 R in formula (1) is a methyl group, R' is an ethyl group,
The polymer compound according to claim 1, which has an intrinsic viscosity [η] of 0.08 to 1.00 in concentrated sulfuric acid. 3. The polymer compound according to claim 1, wherein R in formula (1) is a methyl group, R' is a normal propyl group, and the intrinsic viscosity [η] in concentrated sulfuric acid is 0.08 to 1.00. 4 In formula (1), R is a methyl group, R' is a n-butyl group, and the intrinsic viscosity [η] in concentrated sulfuric acid is 0.08 to
1.50, the polymer compound according to claim 1. 5 General formula (In the formula, R and R' are different numbers of carbon atoms from 1 to 5.
represents an alkyl group. 1. A method for producing poly(dialkoxyphenylene), which comprises polymerizing dialkoxybenzene represented by the following formula in an inert solvent in the presence of a Lewis acid and an oxidizing agent under reduced pressure. 6. The method for producing poly(dialkoxyphenylene) according to claim 5, wherein the polymerization is carried out in the coexistence of an oxidation promoter.