JPH0470972B2 - - 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
Patent No. 14270 discloses those having various structures. The polycyanoaryl ether disclosed in this publication is a polymer or copolymer synthesized from 2,2-bis(4-hydroxyphenyl)propane and dinitrobenzonitrile. However, the polycyanoaryl ether obtained by this method cannot be said to have sufficient heat resistance or mechanical strength for practical use. Therefore, the present inventors conducted various studies and proposed a method for producing polycyanoaryl ether with excellent heat resistance and mechanical strength (Japanese Patent Application Laid-Open No. 60-1403
issue). The method is a method for producing polycyanoaryl ether from dihydroxynaphthalene and dihalogenobenzonitrile. Incidentally, in general, films with heat resistance, mechanical strength, and transparency are expected to have a wide range of uses in various industrial fields, and mass production thereof is desired. Therefore, it is desired to develop a method for forming a transparent film from polycyanoaryl ether having excellent heat resistance and mechanical strength as described above. [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 having excellent heat resistance, mechanical strength, and transparency. [Summary of the Invention] The method for molding the polycyanoarylether film of the present invention is as follows: Contains 50 mol% or more of repeating units represented by
and 0.2 using p-chlorophenol as a solvent
A polycyanoaryl ether having a reduced viscosity [ηsp/c] at 60°C of 0.3 to 2.0 dl/g in a solution having a concentration of g/dl is extruded at 370 to 460°C, and then cooled. 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
If it is less than 50 mol%, heat resistance and mechanical strength will decrease. Preferably it is 80 to 100 mol%. In addition, polycyanoaryl ether used as a film material has the following formula in addition to the repeating unit shown by the formula (): (In the formula, Ar is

It may be a copolymer containing less than 50 mol% of at least one repeating unit represented by the following formula (representing a divalent aryl group other than the formula). As Ar in formula (), for example,

【formula】

【formula】

【formula】

【formula】

【formula】

[Formula] can be given. The polycyanoaryl ether of the present invention has a reduced viscosity [ηsp/c] of the resin solution at 60°C of 0.3 when the polycyanoaryl ether is dissolved in p-chlorophenol to a concentration of 0.2 g/dl. It has a molecular weight of ~2.0 dl/g. When the reduced viscosity is 0.3 dl/g, both heat resistance and mechanical strength are insufficient, and when it exceeds 2.0 dl/g, the melt viscosity becomes high, making it impossible to obtain a uniform transparent film. Preferably, the reduced viscosity is 0.7 to 1.2 dl/g. The molecular weight (reduced viscosity) 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
Examples include -tert-butylphenol and cyanophenol. 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 is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms,
represents an aryl group or an aralkyl group, and X represents a halogen atom). The above-mentioned polycyanoaryl ether can be produced, for example, as follows. That is, dihalogenobenzonitrile and the following formula: (In the formula, M represents an alkali metal.) After reacting the alkali metal salt of dihydroxynaphthalene represented by the formula and optionally with an alkali metal salt of other divalent phenol in the presence of a solvent,
This method involves treatment with water or alcohol. Examples of the compound represented by the formula () include alkali metal salts of 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene. It is preferable to use one type or two or more types. 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 subjected to melt processing. The film is then extruded through a die of an extruder and allowed to cool. 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 guided onto the surface of a cooling roll or into water. Cooling. Furthermore, 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 370 to 460°C. 370℃
If the temperature is less than 460°C, the film forming property will be poor and a homogeneous film will not be obtained, and if the temperature exceeds 460°C, foaming will occur in the extruder and the resulting film will become cloudy and wrinkled. Preferably it is 390-420°C. In addition, although a transparent film can be obtained by applying either the rapid cooling method or the slow cooling method,
From the viewpoint of productivity, it is preferable to apply the rapid cooling method. [Examples of the invention] Example 1 397 g of 2,7-dihydroxynaphthalene was placed in an autoclave with an internal volume of 5 equipped with a stirring device.
(2.48 moles), 430 g (2.5 moles) of 2,6-dichlorobenzonitrile, 414 g (3.0 moles) of potassium carbonate, 2.5 moles of sulfolane, and 1.5 moles of toluene.
1.5 hours at 160°C in a stream of argon, then
The reaction was carried out at 200°C for 1.5 hours. After the completion of the polymerization reaction, a large amount of water was injected to precipitate and recover the granular polymer, which was washed three times with 3 portions of hot water and once with 3 portions of methanol, followed by the following formula:

618 g (yield: 96%) of polycyanoaryl ether having 100 mol% of repeating units represented by the formula was obtained. The reduced viscosity [ηsp/c] at 60° C. of a solution of the obtained polymer having a concentration of 0.2 g/dl using p-chlorophenol as a solvent was measured, and 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 215°C, a melting point of 345°C, and a thermal decomposition start temperature (in air) of 505°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,
Melt and knead at a cylinder temperature of 410℃, and length
It has a linear lip of 300 mm and a gap of 0.2 mm, and is extruded from a T-die with a die temperature (extrusion temperature) of 400°C, and is made to have a wall thickness of 100 μm by electrostatically casting the film onto a cooling drum with a surface temperature of 70°C. A transparent film was obtained. 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, elongation, and elastic modulus, were measured and the results are shown in the table. Examples 2 to 5 The same procedure as in Example 1 was carried out, except that polycyanoaryl ethers having reduced viscosities as shown in the table were produced in the same manner as in Example 1 by extending the reaction time at 200°C in Example 1. A film was formed. The heat resistance, flame retardance, and solvent resistance of the obtained polymer were as good as in Example 1. Example 6 In place of 397 g of 2,7-dihydroxynaphthalene in Example 1, 238.3 g (1.49 mol) of 1,5-dihydroxynaphthalene and 4,4'-biphenol were used.
Except that 184.5 g (0.99 mol) of the mixture was used.
Polycyanoaryl ether was obtained in the same manner as in Example 1. This polycyanoaryl ether is
The following formula:

60 mol% of repeating units represented by [formula], following formula:

It contained 40 mol% of repeating units represented by the formula. When we investigated the thermal properties of the obtained copolymer, we found that
It was confirmed that it had a glass transition temperature of 221°C, a melting point of 302°C, and a thermal decomposition onset temperature (in air) of 519°C, and had sufficient heat resistance for practical use. Next, this copolymer was extrusion molded in the same manner as in Example 1, and the properties of the obtained film were measured in the same manner as in Example 1. The solvent resistance and flame retardance were as good as in Example 1. Comparative Example 1 By shortening the polymerization reaction time at 200°C in Example 1, a polycyanoaryl ether with a reduced viscosity of 0.28 dl/g was obtained. The obtained polymer was extrusion molded into a film in the same manner as in Example 1, but it was too brittle to measure its physical properties. Comparative Example 2 The polymerization reaction time at 200°C in Example 1 was further extended than in Example, and the reduced viscosity was 2.1 dl/g.
A polycyanoaryl ether was obtained. Example 1
Similarly, an attempt was made to extrude the obtained polymer, but extrusion molding was not possible. Comparative Examples 3 and 4 The extrusion temperature was 360°C in Comparative Example 3 and 470°C in Comparative Example 4.
Extrusion molding was carried out in the same manner as in Example 1, except that the temperature was changed to .degree. The film obtained in Comparative Example 3 had uneven thickness, and a homogeneous film could not be obtained. The film obtained in Comparative Example 4 contained bubbles and gel and was not practical. The above results are shown in the table.

【table】

[Table] [Effects of the Invention] As is clear from the examples of the invention, if the polycyanoarylether film is produced according to the present invention, it will have excellent transparency, mechanical strength, and heat resistance. A film is 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: 0.2g/containing 50 mol% or more of repeating units represented by and using p-chlorophenol as a solvent
Reduced viscosity [ηsp/
A method for forming a polycyanoaryl ether film, which comprises extruding a polycyanoaryl ether having a value of 0.3 to 2.0 dl/g at 370 to 460°C and then cooling it.