JPS6114924B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for pressure molding an acetylene polymer.

The acetylene polymer obtained by polymerizing acetylene using a so-called Ziegler-Natsuta catalyst consisting of a transition metal compound and an organometallic compound is known as an organic semiconductor, but it does not melt even when heated.
Moreover, when heated in the presence of oxygen, it easily undergoes oxidative deterioration. Furthermore, no solvent has been found that can dissolve this acetylene high polymer, and the production of practical molded products of acetylene high polymers has heretofore been limited to the following two methods.

(a) A method of pressure molding a powdery acetylene high polymer; (b) A method of polymerizing a catalyst solution at the interface near the free surface of gaseous acetylene and a solid surface coated with the catalyst solution to form a film-like and A method for producing a fibrous acetylene polymer.

However, with the former method (a), only molded products with low mechanical strength can be obtained, and with the latter method (b), raw materials for films and fibers are limited, and in reality, thin films and fibrous molded products can be obtained. Not only could only the molded products be obtained, but the shapes of the molded products were also limited to membrane-like and fibrous-like.

The present invention has been made in view of these points, and aims to provide a method for molding an acetylene polymer molded product having sufficient mechanical strength and a predetermined shape. A gel-like material consisting of 5 to 95% by weight of an acetylene high polymer obtained by polymerization in the presence of an inert organic solvent and 95 to 5% by weight of an inert organic solvent is heated in a mold at a temperature of 100°C. The following is a method for molding an acetylene polymer, which is characterized by pressurizing at a pressure of 1.0 Kg/cm ² or more.

The following two methods are available for producing a gel of an acetylene polymer and an inert organic solvent using a catalyst in the presence of an inert organic solvent.

(1) μ−(η ¹ :η ₅ −
cyclopentadienyl)-tris(η-cyclo-
pentadinyl) dititaninm (Ti−Ti) [(C ₅ H ₄ ) ₅
(C ₅ H ₅ ) ₃ Ti ₂ ] A method for producing a gel-like acetylene polymer by polymerizing acetylene using a special transition metal compound catalyst [SLHsu et.al.j.
chem.Pys.69(1), 106-111 (1978)] (2) (A) transition metal compound and (B) discovered by the present inventors
A method for producing a gel composition by polymerizing acetylene at a concentration of component (A) of 0.1 to 0.0001 mol/l using a catalyst system comprising an organometallic compound and an aromatic compound as a polymerization solvent.

The acetylene high polymer gel composition used in the present invention may be produced by any of the above methods, but the acetylene high polymer gel composition produced by method (2) may be used. This is more desirable because it is more uniform and, as a result, the molded product obtained by pressure molding is also more uniform. In the present invention, the term gel-like material refers to a material in which an acetylene polymer is swollen with an inert organic solvent.

Inert organic solvents used in the present invention include:
aliphatic or aromatic hydrocarbons, halogenated hydrocarbons, ethers, carboxylic acid esters, acid anhydrides,
Examples include ketones.

Among these, aromatic hydrocarbons and aromatic ethers are preferred, and representative examples thereof include benzene, toluene, xylene, ethylbenzene,
Methyl phenyl ether (anisole), ethyl phenyl ether, diphenyl ether, n-dimethoxybenzene, p-dimethoxybenzene, n
-diethoxybenzene, p-diethoxybenzene, 1,3,5-trimethoxybenzene and the like.

The inert organic solvent may be one or a mixed solvent of two or more of the above, or a part of the above inert organic solvent may be replaced with an aliphatic or aromatic alcohol or carboxylic acid after the completion of acetylene polymerization. good.

After the polymerization of acetylene is completed, it is perfectly acceptable to remove a part of the inert organic solvent by a conventional method or to wash the acetylene polymer with an organic solvent to remove the catalyst, but the acetylene polymer may be washed with an organic solvent to remove the catalyst. It is an essential condition of the present invention that the polymer be maintained in a gel state in the presence of an organic solvent.
If the acetylene polymer is dried before pressure molding, molding becomes impossible.

The amount of acetylene high polymer in the gel material used in the present invention is 5 to 95% by weight. If the acetylene high polymer content in the gel-like material is less than 5% by weight, it is difficult to produce a molded product with uniform wall thickness, and if the acetylene high polymer content in the gel-like material exceeds 95% by weight, it will be difficult to produce a molded product with uniform wall thickness. A gel-like material cannot be obtained, making it difficult to produce molded products of arbitrary shapes.

In the present invention, the temperature during pressure molding is 100°C or less, preferably 80°C or less; if it exceeds 100°C, oxidative deterioration of the acetylene polymer will occur, which is inappropriate. Pressure molding at low temperatures is preferable because oxidative deterioration of the acetylene polymer does not occur, but -50
Molding at temperatures below ℃ is not practical.

The pressure during molding is 1Kg/ ^cm2 or more, preferably 5Kg/cm2 or more.
Kg/cm ² , and if the pressure is less than 1 Kg/cm ² , a molded product with sufficiently high mechanical strength cannot be obtained. Although most of the organic solvent is removed from the acetylene polymer during pressure molding, a small amount of organic solvent may remain. Although there may be no practical problem with the remaining organic solvent as it is, it may be removed by a method such as vacuum drying.

By the above method, a molded product having a strong mechanical strength and a predetermined shape can be obtained. The acetylene polymer molded product thus obtained has a very low electrical resistance and exhibits various electrical properties characteristic of so-called semiconductors.

The specific resistance at room temperature is 10 ⁸ for those with many cis structures.
It is about Ω・cm, but it decreases as the number of transformer structures increases, and for a transformer structure only, it is about 10 ⁴
~10 ³ Ω·cm, and also exhibits photoconductivity.
By utilizing the various electrical properties described above, this acetylene polymer can be used as an organic semiconductor material for manufacturing electrical equipment parts such as electrical resistance elements, heat-sensitive elements, and photo-sensitive elements.

In addition, by treating the molded acetylene high polymer obtained in this way with an electron-accepting compound or an electron-donating compound, the electrical conductivity can be increased from 10 ^-8 to 10 -8.
It can be freely controlled over a wide range of 10 ³ Ω ^-1 cm ^-1 .

Representative examples of these electron-accepting compounds include:
Iodine, bromine, bromine iodide, arsenic pentafluoride, antimony pentafluoride, silicon tetrafluoride, phosphorus pentachloride,
Phosphorus pentafluoride, aluminum chloride, aluminum bromide, peroxydisulfuryl difluoride, sulfuric acid, nitric acid, fluorosulfuric acid, trifluoromethanesulfonic acid, chlorosulfuric acid, boron trichloride, boron tribromide, sulfur trioxide, nitrogen dioxide etc. can be given. Further, representative examples of electron donating compounds include sodium, potassium, cesium, and the like.

The present invention will be explained in more detail with reference to Examples below.

Example 1 In a 1 liter glass reactor completely purged with nitrogen gas, 200 ml of toluene purified according to a conventional method was used as a polymerization solvent, 2.94 mmol of tetrabutoxytitanium and 7.34 mmol of triethylaluminum were used as catalysts.
The catalyst was prepared by charging mmol in this order at room temperature. The catalyst was a homogeneous solution. The reactor was cooled with liquid nitrogen, and the nitrogen gas in the system was exhausted using a vacuum pump. Cool the reactor to -78°C and
Purified acetylene gas at a pressure of 1 atm was blown into the catalyst solution while stirring it with a stirrer. At the beginning of the polymerization reaction, the entire system became agar-like and stirring became difficult.

The polymerization reaction was continued for 24 hours while maintaining the acetylene gas pressure at 1 atm. The system was agar-like with a reddish-purple color. After the polymerization was completed, unreacted acetylene gas was removed, and the system was washed four times with 200 ml of purified toluene while keeping the temperature at -78°C. Even after washing, the solution remained slightly brown and the catalyst was not completely removed. The gel-like acetylene polymer swollen in toluene was in the form of uniform chips with intertwined fibrils, and no powder or lump-like polymer was produced.

When a part of the homogeneous gel was taken out and dried, and the amount of acetylene high polymer in the gel was measured, it was found that the gel contained 10% by weight of acetylene high polymer.

The above gel-like material is 10mm thick on the inside and 100mm long.
It was placed in a rectangular parallelepiped mold with a width of 50 mm, sandwiched between chloroplated ferro plates, and press-molded at room temperature while removing toluene at a pressure of 100 Kg/cm ² to form a flexible and strong film with a thickness of 5 mm. A film-like molded product was obtained. This film-like molded product was a p-type semiconductor with an electrical conductivity (measured by the DC four-probe method) of 5×10 ^-8 Ω ^-1 ·cm ^-1 at 20°C.

Also, put this film-shaped molded product into a flask,
After evacuating air with a vacuum pump, iodine gas was introduced at room temperature vapor pressure and the film-shaped molded product was treated for 1 hour. After 1 hour of treatment, unreacted iodine was evacuated using a vacuum pump to obtain an iodine-treated film-like molded product. This iodine-treated film-shaped molded product has an electrical conductivity of 95Ω ^-1 cm at 20℃.
^-1 p-type semiconductor.

Example 2 The homogeneous gel-like material obtained by polymerization in Example 1 (containing 10% by weight of acetylene high polymer) was vacuum-dried to obtain a gel-like material containing 50% by weight of acetylene high polymer.

The above gel-like material was placed in a cylindrical mold with an inner radius of 50 mm, and molded at room temperature and under a pressure of 200 kg/cm ² while removing toluene, a strong and flexible cylindrical mold with a film thickness of 12 mm was formed. I got something. This molded product was a p-type semiconductor with an electrical conductivity of 4.1×10 ^-8 Ω ^-1 ·cm ^-1 at 20°C.

This molded product was placed in a flask, and after evacuating the air with a vacuum pump, it was treated with arsenic pentafluoride vapor. The resulting arsenic pentafluoride-treated molded product was a p-type semiconductor with an electrical conductivity of 550Ω ^-1 ·cm ^-1 at 20°C.

Example 3 A homogeneous gel was obtained by preparing a catalyst and polymerizing acetylene in the same manner as in Example 1, except that anisole was used in place of toluene used as the polymerization solvent in Example 1. The content of acetylene high polymer in this gel was 12% by weight.

This gel-like material was vacuum-dried to concentrate the acetylene high polymer content to 70% by weight, and this concentrate was placed in a cylindrical mold with an inner radius of 50 mm and heated to 250% by weight at room temperature.
Pressure molding was performed while removing anisole at a pressure of Kg/cm ² to obtain a tough and flexible cylindrical molded product with a film thickness of 25 mm. The electrical conductivity of this molded product is 20℃.
It was a p-type semiconductor of 5.5×10 ^-8 Ω ^-1 ·cm ^-1 .

This molded product was placed in a flask, the air was evacuated using a vacuum pump, and then treated with sulfur trioxide vapor. The obtained sulfur trioxide-treated molded product was a p-type semiconductor with an electrical conductivity of 620Ω ^-1 ·cm ^-1 at 20°C.

Example 4 A uniform gel-like material was obtained by preparing a catalyst and polymerizing acetylene in exactly the same manner as in Example 1, except that the polymerization of acetylene was carried out at room temperature. The acetylene high polymer content in this gel was 18% by weight.

This gel-like material was vacuum-dried to concentrate the acetylene high polymer content to 40% by weight, and this concentrate was pressure-molded in the same manner as in Example 3 to obtain a cylindrical molded product. The electrical conductivity of this molded product is 20℃.
It was a p-type semiconductor of 2.7×10 ^-4 Ω ^-1 ·cm ^-1 .

This molded product was treated with iodine in the same manner as in Example 1. The obtained iodine-treated molded product was a p-type semiconductor with an electrical conductivity of 16Ω ^-1 ·cm ^-1 at 20°C.

Claims (1)

[Claims] 1. A gel-like material consisting of 5 to 95% by weight of an acetylene high polymer obtained by polymerization in the presence of an inert organic solvent and 95 to 5% by weight of an inert organic solvent is heated in a mold at a temperature of 100°C or less. , a method for molding an acetylene polymer, characterized by pressurizing at a pressure of 1.0 Kg/cm ² or more.