JPS626566B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing an acetylene polymer gel having good moldability. It is already known that acetylene polymers obtained by polymerizing acetylene using so-called Ziegler-Natsuta catalysts, which are composed of transition metal compounds and organometallic compounds, are organic semiconductor materials useful as electronic and electrical devices. . However, the acetylene polymer obtained in this way does not melt even when heated, and is easily subjected to oxidative deterioration under heating, so that the molding method used for ordinary thermoplastic resins cannot be used. Furthermore, a solvent that dissolves this acetylene high polymer has not yet been found.
Therefore, methods for producing practical molded articles of acetylene polymers have been limited to the following two methods. (a) A method of pressure molding a powdered acetylene polymer. (b) A catalyst solution prepared by dissolving a catalyst system consisting of a transition metal compound and an organometallic compound in an aromatic hydrocarbon such as toluene or an aliphatic hydrocarbon such as hexadecane and the interface near the free surface of gaseous acetylene or on a solid surface. A method for producing membranous and fibrous acetylene polymers by polymerizing on the surface coated with this catalyst solution (Japanese Patent Publication No. 1973-
No. 32581). However, with the former method (a), only a molded product with low mechanical strength can be obtained, and with the latter method (b), not only the shape is limited to membrane-like and fibrous-like shapes, but also the thickness is limited, and essentially only thin-walled membrane-like and fibrous molded products can be obtained. Therefore, in recent ^years , a method for producing a new acetylene polymer ^that does not have these problems has been studied.
cyclopentadienyl)−tris(η−
cyclopentadienyl) dititanium (Ti−Ti)
_{[ SLHsu _ _ _ _ _}
et al., J.chem.Phys., 69 (1), 106-111 (1978)]. However, since this method uses a very special catalyst, the ratio of catalyst cost to manufacturing cost becomes extremely high when producing a gel-like material industrially. In view of the above points, the present inventors conducted various studies on a method for producing a gel-like acetylene polymer with good moldability without using a special catalyst, and as a result, they arrived at the present invention. That is, the present invention provides a method for producing an acetylene polymer by polymerizing acetylene using a catalyst system mainly composed of a transition metal compound and an organometallic compound, in which an aliphatic compound or alicyclic compound is used as a polymerization solvent. and a cyclic ether compound, and a transition metal compound is added to the polymerization solvent 1 using at least one compound selected from the group consisting of
The present invention relates to a method for producing a gel-like acetylene polymer, which is used at a molar concentration of 0.0001 to 0.1 and is characterized in that at least the initial stage of polymerization is carried out under stirring. The gel-like material referred to in the present invention is a material in which fibrous microcrystals (fibrils) of acetylene high polymer are entangled,
It is in a state swollen in a solvent, and is essentially different from a normal crosslinked gel. According to the method of the present invention, a gel-like product of acetylene polymer can be easily obtained using a catalyst system already widely used in the industry. It is extremely useful industrially because uniform molded products of any shape and wall thickness with excellent mechanical strength can be easily produced. The present invention will be explained in detail below. The transition metal compounds used in the present invention include titanium, vanadine, chromium, iron, cobalt,
Tungsten and molybdenum metal halogen atoms or alkyl groups, alkenyl groups, aryl groups, aralkyl groups, alkoxide groups, phenoxide groups, carboxylic acid residues, cyclopentadienyl groups, acetylacetone with at most 20 carbon atoms residue, a compound having carbon monoxide (carbonyl group), and a complex of this compound with an electron-donating compound such as pyridine, triphenylphosphine, and dipyridyl. Among transition metal compounds, titanium, vanadine,
Compounds of iron, chromium and cobalt are preferred;
Particularly preferred are titanium compounds. Representative examples of preferred transition metal compounds include transition metal compounds whose general formulas are represented by formulas (1) to (3). Ti(OR) ₄ (1) (R is an alkyl group or allyl group (aryl) having at most 20 carbon atoms) M(acac) ₃ (2) MO(acac) ₂ (3) [(acac) is acetyl acetonate group, M is a transition metal of titanium, vanadine, iron, chromium, and cobalt. Typical examples of these transition metal compounds include, for example, tetramethoxytitanium, tetraethoxytitanium, tetran-propoxytitanium,
Tetraisopropoxytitanium, tetra n-butoxytitanium, tetraisobutoxytitanium, tetraoctadecyloxytitanium, tetraphenoxytitanium, trisacetylacetonate titanium, trisacetylacetonate vanadium, trisacetylacetonate iron, trisacetylacetonate Examples include chromium, cobalt trisacetylacetonate, titanium oxyacetylacetonate, vanadium oxyacetylacetonate, and the like. The organometallic compound used in the present invention is an organometallic compound containing at least one metal from group A, B, B, and B of the periodic table, and the general formula of some of them is represented by the following formula. It is something. MRn [However, M is A, B, B, or a metal from Group B of the periodic table, and R is a metal with a maximum number of carbon atoms.
20 alkyl groups, alkenyl groups, allyl groups, aralkyl groups, alkoxide groups,
An organic group selected from the group consisting of a phenoxy group and a cyclopentadienyl group, or a hydrogen atom or a halogen atom, which may be the same or different, but at least one of them is a hydrogen atom or the organic group. , n is the highest valence number of the metal or a positive integer less than that.] Other organometallic compounds include complexes of the above organometallic compound and equimolar amounts of pyridine, triphenylphosphine, or diethyl ether; Mention may be made of reactants of 1 mol of said organometallic compound with at most 2.0 mol of water as well as double salts of two of said organometallic compounds. Among the organometallic compounds used in the present invention, typical ones include those containing magnesium, calcium, zinc, boron, aluminum, gallium, silicon, and tin. Organometallic compounds of aluminum and tin are preferred, and organoaluminium-based compounds are particularly preferred. Typical examples of the organoaluminum compounds include triethylaluminum, triisobutylaluminum, trihexylaluminum, diethylaluminum chloride, di-n-butylaluminum chloride, ethylaluminum sesquichloride, diethylaluminum butoxy, and the reaction of triethylaluminum with water. The product [reaction ratio 1:0.5 (molar ratio)] is mentioned. Examples of other organoaluminum compounds include aluminum siloxalene compounds, aluminum amide compounds, dialmoxalene compounds, and double salts containing the above organoaluminum compounds. The general formula of the aluminum-siloxalene compound used as the organometallic compound in the present invention is shown by the following formula. [However, R ¹ , R ² and R ³ may be the same or different, and are a halogen atom or an alkyl group or alkoxy group having at most 10 carbon atoms, and R ⁴ is an alkyl group having at most 10 carbon atoms. and R ⁵
is a halogen atom, an alkyl group or alkoxy group having at most 10 carbon atoms, or a general formula

[expression] or

[Formula] (However, R ⁶ , R ⁷ and R ⁸ may be the same or different, and are the same as R ¹ , R ² and R ³ above, and n is
(a positive integer of 10 or less)] Representative examples of the aluminum-siloxalene compounds used in the present invention include trimethyldimethyl-siloxalene, trimethyldiethyl-siloxalene, and trimethyldi-n
-Propyl-siloxsalene, trimethyl-diisobutyl-siloxsalene, trimethyldioctyl-
Mention may be made of siloxsalene, trichlorodimethyl-siloxsalene, dimethylethyldiethyl-siloxsalene, trimethoxydimethyl-siloxsalene, triethyldimethyl-siloxsalene, trimethyldimethoxy-siloxsalene, trimethyldimethoxy-siloxsalene and trimethoxydichloro-siloxsalene. Further, the general formula of the aluminum amide compound used as the organometallic compound in the present invention is shown by the following formula. (However, R ¹ , R ² and R ³ may be the same or different and are a hydrogen atom or an alkyl group having at most 10 carbon atoms, and R ⁴ is a halogen atom or an alkyl group having at most 10 carbon atoms. Among the aluminum amide compounds used in the present invention, typical examples include diethylaluminum dimethylamide, diethylaluminum diethylamide, dimethylaluminum dimethylamide, dimethylaluminum di-n
-butyramide, diethylaluminium di-n-
butylamide, dichloroaluminum dimethylamide, dimethylaluminum dioctylamide,
Mention may be made of diisobutylaluminum di-n-butylamide and dihexylaluminum dioctylamide. The general formula of the dialmoxane compound used as the organometallic compound in the present invention is shown by the following formula. (However, R ¹ , R ² and R ³ may be the same or different and are a halogen atom or an alkyl group or alkoxy group having at most 10 carbon atoms, and R ⁴ is an alkyl group having at most 10 carbon atoms. Among the dialmoxane compounds used in the present invention, representative ones include tetramethyldialumoxane, tetraethyldialumoxane, tetraisobutyldialumoxane, and 1.1-
Dimethyl-3,3-diethyldialumoxane, tetraisobutyldialumoxane, 1,1-dimethyl-3,3-diisobutyldialumoxane, tetradecyldialumoxane, trimethyldialumoxane chloride and triethyldialumoxane chloride can give. Among the organometallic compounds used in the present invention, typical examples of organometallic compounds other than organoaluminum compounds include diethylmagnesium, ethylmagnesium chloride, methylmagnesium iodide,
Allyl magnesium chloride; normal propylmagnesium chloride, tertiary-butylmagnesium chloride, phenylmagnesium bromide, diphenylmagnesium, ethyl ethoxymagnesium, dimethylzinc, diethylzinc, diethoxyzinc, phenylcalcium iodide, dibutylboron chloride, diborein, trimethylboron, triethylsilane, silicon tetrahydride, triethylsilicone hydride, tetramethyltin, tetraethyltin, trimethyltin chloride, dimethyltin dichloride, trimethyltin hydride, ethylmagnesium bromide and ethyl ether Complexes and reaction products of diethylzinc and water [H ₂ O/Zn(C ₂ H ₅ ) ₂
<2.0 (molar ratio)]. Further, as the organic compound used in the present invention, double salts of two types of the above-mentioned organic compounds (for example, lithium aluminum tetrahydride,
calcium (tetraethylzinc). In carrying out the present invention, these organometallic compounds may be used alone or in combination of two or more. Although the ratio of the organometallic compound to the transition metal compound used is not particularly limited, it is generally preferable that the ratio of the organometallic compound to the transition metal of the transition metal compound is within the range of 1 to 100 in terms of molar ratio. A third component can be used in combination with these transition metal compounds and organometallic compounds, if necessary, to control the polymer yield, polymerization rate, etc. Third
Typical examples of the components include oxygen-containing compounds such as alcohols, peroxides, carboxylic acids, acid anhydrides, acid chlorides, esters, and ketones, as well as other nitrogen-containing compounds, sulfur-containing compounds,
Halogen-containing compounds, molecular iodine, other Lewis acids, etc. can also be used. The amount of the third component used is at most 20 times the mole of the transition metal.
There is no particular restriction on the order of addition of these catalyst systems. Polymerization solvents used in the present invention are aliphatic hydrocarbons, aliphatic ether compounds, halogenated aliphatic hydrocarbons, aliphatic compounds such as aliphatic carboxylic acid esters, fatty cyclic compounds, and cyclic ether compounds. Among these polymerization solvents, it is particularly preferable to use aliphatic hydrocarbons, aliphatic ether compounds, alicyclic compounds, and cyclic ether compounds having a carbon number of 4 or more and 20 or less, and representative examples include, for example. Examples include pentane, hexane, heptane, octane, nonane, decane, dodecane, cyclohexane, tetrahydrofuran, dioxane, diethyl ether, and ethyl methyl ether. These polymerization solvents may be used alone or in combination of two or more. In addition, these polymerization solvents are
It may be used in combination with 50% by volume or less of an aromatic compound. In order to obtain the acetylene polymer gel of the present invention, the concentration of the transition metal compound in the catalyst system should be in the range of 0.0001 to 0.1 mol, preferably 0.001 to 0.1 mol, based on 1 mol of the polymerization solvent. Polymerization is necessary, and if the concentration of the transition metal compound is 0.1 mol or more per 1 mole of polymerization solvent, it is difficult to obtain a gel-like material with good processability. If the amount is less than 0.0001 mol per 1 mole of solvent, most of the acetylene polymer will become powdery. The catalyst solution may be homogeneous or non-uniform, but from the viewpoint of easy catalyst removal, it is preferable that the catalyst solution be homogeneous. The polymerization temperature is not particularly limited, but is usually -
The temperature is preferably 100°C to 300°C, and particularly preferably -80°C to 200°C for ease of handling. In the present invention, the steric structure of the acetylene polymer produced can be controlled by adjusting the polymerization temperature and the preparation conditions of the catalyst system, but in general, the lower the polymerization temperature, the higher the flexible cis content. An acetylene high polymer is produced, and if the polymerization temperature is high, an acetylene high polymer with a high trans content is produced. Although there is no particular restriction on the pressure of acetylene gas during polymerization, it is practically preferable to carry out the polymerization at a pressure of 10 atmospheres or less. In the present invention, it is necessary to bring acetylene into contact with the catalyst while stirring the catalyst solution at the start of polymerization. There is no particular restriction on the order of addition of the transition metal compound, organometallic compound, and acetylene. If polymerization is started while the catalyst solution is left standing without stirring, a film of acetylene high polymer will be formed on the surface of the catalyst solution, and a gel-like acetylene high polymer will not be obtained. The catalyst can be removed from the acetylene polymer gel obtained by polymerization by the usual removal methods, such as washing with an organic solvent that dissolves the catalyst, but it does not specifically remove the catalyst. There is no problem in using it. The acetylene polymer gel obtained in this manner can be easily molded under pressure into a uniform molded article having any desired shape and wall thickness. By utilizing its electrical properties, the acetylene polymer obtained by the production method of the present invention is useful as an organic semiconductor material for producing parts of electronic devices such as electrical resistance elements, heat-sensitive elements, photosensitive elements, etc. It is. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 In a glass reactor 1 completely purged with nitrogen gas, 200 ml of n-heptane purified in a conventional manner as a polymerization solvent, 2.94 mmol of tetrabutoxytitanium and 11.76 mmol of triethylaluminum as a catalyst were added sequentially at room temperature. A catalyst solution was prepared. The catalyst solution was a homogeneous solution. The reactor was cooled with liquid nitrogen, and the nitrogen gas in the system was exhausted using a vacuum pump. The reactor was cooled to −78° C., and while stirring the catalyst solution with a magnetic stirrer, purified acetylene gas at a pressure of 1 atmosphere was blown into the reactor. At the beginning of the polymerization reaction, the entire system became agar-like and stirring became difficult. 24 while maintaining the acetylene gas pressure at 1 atm.
The polymerization reaction was continued for a period of time. The system was agar-like with a reddish-purple color. After the polymerization was completed, unreacted acetylene gas was removed, and the system was repeatedly washed four times with 200 ml of purified n-heptane while maintaining the temperature at -78°C. Even after washing, the solution remained slightly brownish and the catalyst was not completely removed. The gel-like acetylene polymer swollen in n-heptane was in the form of chips in which fibrous microcrystals (fibrils) were entangled. When this gel-like material was sandwiched between chromium-plated ferro plates and press-molded at room temperature under a pressure of 100 kg/cm ² , a flexible film of acetylene high polymer with a reddish-brown metallic luster was obtained. This film has electrical conductivity (DC four terminal method) of
It was a P-type semiconductor with a resistance of 6.5×10 ^-7 Ω ^-1 cm ^-1 at 20°C. Comparative Example 1 In Example 1, the catalyst system was the same as in Example 1, except that when acetylene was polymerized, acetylene gas was blown into the polymerization system while it was left standing without stirring. Polymerization of acetylene was carried out in the same manner. A thin polymer film was formed on the surface of the polymerization solvent in the early stage of polymerization, and even after 24 hours of polymerization, only the film thickness on the surface of the polymerization solvent became thicker and almost no gel-like material was obtained. Example 2 Into a glass reactor (1) completely purged with nitrogen gas, 200 ml of diethyl ether purified in a conventional manner as a polymerization solvent, 0.29 mmol of tetrabutoxytitanium and 1.76 mmol of triisobutylaluminum as catalysts were added sequentially at room temperature. A catalyst solution was prepared. The catalyst solution was a homogeneous solution. The reactor was cooled with liquid nitrogen, and the nitrogen gas in the system was exhausted using a vacuum pump. Then, the temperature of the reactor was returned to room temperature, and while stirring the catalyst solution with a magnetic stirrer, purified acetylene gas at a pressure of 1 atmosphere was blown into the reactor. 10 after starting the polymerization reaction
After minutes, the entire system turned into an agar-like gel. Stirring was continued and polymerization was continued while maintaining the acetylene gas pressure at 1 atm for 24 hours. The entire system was agar-like with a blackish brown color. After the polymerization reaction was completed, unreacted acetylene gas was removed, and the mixture was washed four times with 200 ml of a mixed solvent of methanol and diethyl ether in a ratio of 1:2 (volume ratio). The obtained gel-like material was the same gel-like material as in Example 1, and when it was pressure-molded in the same manner as in Example 1, a flexible film was obtained. Example 3 Except that 5.0 mmol of titanium trisacetylacetonate and 27.0 mmol of triethylaluminum were used in place of the catalyst components tetrabutoxytitanium and triethylaluminum used in Example 1, and tetrahydrofuran was used in place of n-heptane. A gel-like material similar to that of Example 1 was obtained by preparing a catalyst and polymerizing acetylene in exactly the same manner as in Example 1. Example 4 A catalyst was prepared in exactly the same manner as in Example 1, except that 5.0 mmol of iron trisacetylacetonate and 25.0 mmol of triisobutylaluminum were used instead of the catalyst components tetrabutoxytitanium and triethylaluminum used in Example 1. Then, acetylene was polymerized to obtain a gel-like material similar to that in Example 1. Example 5 Instead of the catalyst components tetrabutoxytitanium and triisobutylaluminum used in Example 2,
A catalyst was prepared and acetylene was polymerized in the same manner as in Example 2, except that 0.5 mmol of trisacetylacetonatochromium and 2.5 mmol of triisobutylaluminum were used, and cyclohexane was used instead of diethyl ether. A gel-like substance was obtained. Comparative Example 2 200 ml of n-heptane purified in a conventional manner as a polymerization solvent, 0.01 mmol of tetrabutoxytitanium and 0.1 mmol of triethylaluminum as a catalyst were placed in the glass reaction vessel 1 completely purged with nitrogen gas at room temperature. A catalyst solution was prepared. The catalyst solution was a homogeneous solution. The reactor was cooled with liquid nitrogen, and the nitrogen gas in the system was exhausted using a vacuum pump. The reactor was cooled to -78 DEG C. and purified acetylene gas was blown in at a pressure of 1 atmosphere while stirring the catalyst solution with a magnetic stirrer. As the polymerization began, a dark brown acetylene polymer began to precipitate in the form of a powder. The polymerization reaction was carried out for 24 hours with stirring at -78° C. while maintaining the pressure of the acetylene gas at 1 atm, but the acetylene high polymer obtained was in the form of a powder. This powdered acetylene high polymer was washed four times with 200 ml of purified n-heptane and then vacuum dried to obtain a powdered acetylene high polymer. When this powdered acetylene high polymer was sandwiched between chromium-plated ferro plates and press-molded at a pressure of 100 kg/cm ² at room temperature, the molded product obtained was extremely brittle and could not be obtained in the form of a film. Comparative Example 3 Into a glass container of 1 which was completely purged with nitrogen gas, n purified according to a conventional method was added as a polymerization solvent.
- A catalyst solution was prepared by sequentially charging 200 ml of heptane, 40 mmol of tetrabutoxytitanium and 80 mmol of triethylaluminum as catalysts. The catalyst solution was a homogeneous solution. When acetylene was polymerized using the obtained catalyst solution in exactly the same manner as in Example 1, some of the acetylene high polymer was in the form of a gel.
Most of the acetylene polymers were solid block polymers that underwent phase separation. Post-treatment was carried out in the same manner as in Example 1, and then Example 1
When pressure molding was carried out in the same manner as above, a uniform film could not be obtained.

Claims (1)

[Claims] 1. In a method for producing an acetylene polymer by polymerizing acetylene using a catalyst system mainly composed of a transition metal compound and an organometallic compound, aliphatic compounds, alicyclic compounds, and cyclic ether compounds are used as polymerization solvents. At least one compound selected from the group consisting of: a transition metal compound is used at a concentration of 0.0001 to 0.1 molar relative to 1 part of the polymerization solvent, and at least the initial stage of the polymerization is carried out under stirring. A method for producing a gel-like product of an acetylene high polymer.