JPH0523935B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field of the Invention] The present invention relates to a method for forming a polycyanoarylether film having excellent heat resistance, mechanical strength, and transparency. [Technical background of the invention and its problems] Polycyanoaryl ether is disclosed in
No. 14270 and Japanese Unexamined Patent Publication No. 59-206433 disclose various structures. It is known that the polycyanoaryl ethers disclosed in these publications are crystalline polymers with excellent heat resistance. In general, films with heat resistance and transparency are
It is expected to have a wide range of applications in various industrial fields, and mass production is desired. However, when a film is formed from the above-mentioned polycyanoaryl ether by a conventional method, although the film obtained has heat resistance, it has generally not been transparent. Therefore, it is desired to develop a method for forming a transparent film from polycyanoaryl ether having heat resistance. [Object of the invention] The present invention meets the above-mentioned demands,
The purpose of the present invention is to provide a method for forming a polycyanoaryl ether film that has excellent transparency, heat resistance, and mechanical strength. [Summary of the Invention] The method for forming the polycyanoarylether film of the present invention is as follows: A polycyanoaryl ether containing 80 mol% or more of the repeating unit represented by and having a number average molecular weight of 30,000 to 70,000 is extruded at 350 to 450°C, and then rapidly cooled to 150°C or less. do. First, polycyanoaryl ether having the above-mentioned characteristics is used as a film material in the present invention. In such polycyanoaryl ether, the content of repeating units represented by formula () is 80
If it is less than mol%, heat resistance and mechanical strength will decrease. In addition to the repeating unit shown by the formula (), the polycyanoaryl ether used as a film material has the following formula: (In the formula, Ar is

It may be a copolymer containing less than 20 mol% of at least one type of repeating unit represented by the following formula (representing an arylene group other than the formula). As Ar in formula (), for example,

【formula】

【formula】

【formula】

【formula】

【formula】

[Formula] can be given. Next, the above-mentioned number average molecular weight was determined by dissolving this polycyanoaryl ether in N-methylpyrrolidone to a concentration of 70 mg/dl, and performing high-temperature gel permeation chromatography (measuring temperature 135 mg/dl) on this solution. ℃) refers to the number average molecular weight in terms of polystyrene. If the number average molecular weight is less than 30,000, a film can be obtained by extrusion molding, which will be described later, but the strength of the film will be too low to be practical. On the other hand, if the number average molecular weight exceeds 70,000, the melt viscosity increases when the polymer is melted, making extrusion molding difficult. The number average molecular weight is adjusted by setting the reaction conditions (temperature, time) during the polymerization reaction to predetermined values, or by adding a predetermined amount of a molecular weight regulator. In the latter case, the molecular weight modifier has the following formula: (In the formula, R represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group, an aralkyl group, or a cyano group.) It is preferable to use a monovalent phenol represented by, for example, cumylphenol. , phenylphenol, p
-tert-butylphenol and cyanophenol are preferred. In the polycyanoaryl ether having the above characteristics, the repeating units represented by the formula () are linear, or the repeating units represented by the formula () and () are mutually disordered or ordered. It is composed of a linear chain connected to each other, and its terminal ends are -H, -X,

【formula】

【formula】

[Formula] (where R represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group, or an aralkyl group,
X represents a halogen atom). The above-mentioned polycyanoaryl ether can be produced, for example, as follows. That is, this is a method in which dihalogenobenzonitrile and an alkali metal salt of hydroquinone and, if necessary, an alkali metal salt of another divalent phenol are subjected to a polymerization reaction in the presence of a solvent, followed by treatment with water or alcohol. The film forming method of the present invention is carried out as follows using the above-mentioned polycyanoaryl ether. That is, first, the above-mentioned polycyanoaryl ether is supplied to a melt extruder and melt-treated. The film is then extruded through a die of an extruder and rapidly cooled. When the T-die method (cast method) is applied as the extrusion method, the molten polycyanoaryl ether is extruded from the die of the extruder into a film, and the extruded film is immediately introduced onto the surface of a cooling roll or into water. Cool quickly. Also,
An inflation method may be applied as the extrusion method. In the present invention, in the extrusion molding described above, it is necessary that the extrusion temperature is 350 to 450°C. 350℃
If the temperature is less than 450°C, film forming properties are poor and a homogeneous film cannot be obtained, and if it exceeds 450°C, discoloration of the film or foaming inside the film occurs, making it impossible to obtain a good quality film. Preferably it is 360-400°C. Further, the temperature during cooling of the film needs to be 150°C or less. If the temperature exceeds 150°C, the polycyanoaryl ether crystallizes, resulting in a decrease in the transparency of the film, or in the film becoming cloudy or wrinkled. [Embodiments of the invention] Example 1 In a separable flask with an internal volume of 5, 2,5-
215 g (1.25 mol) of dichlorobenzonitrile,
Add 136.3 g (1.24 moles) of hydroquinone, 207 g (1.5 moles) of potassium carbonate, 2.5 g (1.5 moles) of potassium carbonate, 2.5 g of sulfolane, and 1 mole of toluene, and while blowing argon gas,
℃ for 1.5 hours, then heated to 200℃ for 1.5 hours.
Allowed time to react. Next, the obtained reaction product was poured into methanol to precipitate a polymer, and then pulverized using a Warning blender, washed 5 times with 5 portions of water and 2 times with 5 portions of methanol, and dried. Polycyanoaryl ether 240g
I got it. Here, the number average molecular weight of the obtained polymer in terms of polystyrene was measured by high-temperature gel permeation chromatography (measurement temperature 135°C) of a solution with a concentration of 70 mg/dl using N-methylpyrrolidone as a solvent. , the results are shown in the table. In addition, when we investigated the thermal properties of this polymer, we found that
It was confirmed that it had a glass transition temperature of 180°C, a melting point of 350°C, and a thermal decomposition onset temperature (in air) of 530°C, and had sufficient heat resistance for practical use. Next, the solvent resistance of this polymer was examined, and it was found to be insoluble in the following solvents: acetone, ethanol, toluene, methylene chloride, and chloroform. Furthermore, after exposing this polymer to the flame of a lighter for 10 seconds, when the flame was moved away, the flame quickly extinguished, and no melt dripping was observed, indicating that the flame retardance was good. Next, this polymer powder was poured into a cylinder with a diameter of 30 mm.
mm, ratio of cylinder total length (L) to diameter (D) L/D = 25,
Supplied to a melt extruder with a screw rotation speed of 60 rpm,
Cylinder temperature 400℃, die temperature (extrusion temperature) 390℃
Under these conditions, a film having a width of 300 mm and a wall thickness of 100 μm was extruded, and the extruded film was immediately electrostatically cast using a cooling roll with a surface temperature (cooling temperature) of 120° C. to obtain a transparent film. The transparency of the film was determined by measuring the light transmittance at a wavelength of 480 nm for a film with a thickness of 100 μm. The mechanical properties of the obtained film, ie, breaking strength, yield strength, elongation, and elastic modulus, were measured and the results are shown in the table. Examples 2 to 5 Example 1 was repeated except that polycyanoaryl ether having the number average molecular weight as shown in the table was produced in the same manner as in Example 1 by extending the polymerization reaction time at 200°C in Example 1. A film was formed in the same manner as above. The heat resistance, flame retardance and solvent resistance of the obtained polymer were the same as in Example 1, the transparency of the obtained film was good as in Example 1, and the mechanical properties of the film were as shown in Table 1. It exhibited the following characteristics. Comparative Example 1 By shortening the polymerization reaction time at 200° C. in Example 1, a polycyanoaryl ether with a number average molecular weight of 17,000 was obtained. Next, this polymer was extrusion molded in the same manner as in Example 1, but the resulting film was so brittle that it was impossible to measure its mechanical properties. Comparative Example 2 A polycyanoaryl ether having a number average molecular weight of 92,000 was obtained by extending the polymerization reaction time at 200°C in Example 1 more than in Examples 2 to 5. Next, extrusion molding of this polymer was attempted in the same manner as in Example 1, but the melt viscosity of the polymer was too high to form a film. Examples 6 to 7 The same as the examples except that the polycyanoaryl ether having a number average molecular weight of 46,000 obtained in Example 3 was used and the extrusion temperature was 360°C in Example 6 and 430°C in Example 7. Extrusion molding was carried out in the same manner as in Example 1. The mechanical properties and transparency of the obtained film were equivalent to those of Example 3. Comparative Examples 3 to 4 The same as the examples except that the polycyanoaryl ether having a number average molecular weight of 46,000 obtained in Example 3 was used and the extrusion temperature was 340°C for Comparative Example 3 and 460°C for Comparative Example 4. Extrusion molding was carried out in the same manner as in Example 1. In the film obtained in Comparative Example 3, the measured values of mechanical properties differ depending on each location of the film, and there are good locations and poor locations regarding transparency.
Variations in physical properties were observed on the same film, making the film poor in practical use. On the other hand, the film obtained in Comparative Example 4 had bubbles and gel portions, and was poor in practical use. Examples 8 to 9 The same as the examples except that the polycyanoaryl ether having a number average molecular weight of 46,000 obtained in Example 3 was used and the cooling temperature was 100°C in Example 8 and 160°C in Example 9. Extrusion molding was carried out in the same manner as in Example 1. The mechanical properties of the obtained film were the same as those of Example 3, the transparency of the film was good, and the density was
A homogeneous film of 1.271 g/ml was obtained. Comparative Example 5 Using polycyanoaryl ether with a number average molecular weight of 46,000 obtained in Example 3, the cooling temperature was
Extrusion molding was carried out in the same manner as in Example 1 except that the temperature was 180°C. The obtained film became cloudy due to crystallization of the polymer, and wrinkles were also observed. The above results are shown in the table.

【table】

[Table] [Effects of the Invention] As is clear from the examples of the invention, if a polycyanoarylether film is produced by the method of the present invention, it will have excellent transparency, mechanical strength, and heat resistance. An excellent film can be obtained. Therefore, the film obtained by the method of the present invention is useful as a film for various industries (for example, electronic/electrical equipment, machinery) that require transparency, heat resistance, and mechanical strength, and as a film for household use.

Claims (1)

[Claims] Primary formula: A polycyanoaryl ether containing 80 mol% or more of the repeating unit represented by and having a number average molecular weight of 30,000 to 70,000 is extruded at 350 to 450°C, and then rapidly cooled to 150°C or less. A method for forming polycyanoaryl ether film.