JP3331889B2 - Method for producing polyethersulfone resin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for producing a polyethersulfone resin film in which a polyethersulfone resin solution is cast on a metal substrate, dried, and then the formed film is peeled from the metal substrate. .

[0002]

2. Description of the Related Art As a method for producing a polyethersulfone resin film, a solution in which a polyethersulfone resin is dissolved is extruded from a die, cast on a metal substrate, and dried.
There is a solution casting method for peeling the formed film. The film obtained by the solution casting method has few foreign substances,
An optically isotropic film having excellent thickness accuracy and surface smoothness can be obtained. In recent years, in recent years, for raw materials for retardation films, films for liquid crystal displays such as polarization protection films,
A film manufactured by this solution casting method is used.

[0003]

However, when the polyethersulfone resin solution is cast on a metal substrate, and after drying, the formed film is peeled off, the adhesive strength between the film and the metal substrate is strong. Therefore, it becomes difficult to peel off, and problems such as stretching and breaking of the film occur. On the other hand, if a polyester film or the like subjected to a release treatment is used as a base material, such a problem does not occur,
It is difficult to reuse the polyester film in order to maintain the surface smoothness and the like, and it cannot be said to be an advantageous method when considering industrial production.

[0004]

Means for Solving the Problems The present inventors cast a polyethersulfone resin solution on a metal substrate, dried it,
In a method of manufacturing a polyethersulfone resin film by peeling the formed film from a metal substrate, as a result of intensive studies on improvement of the releasability, a polyoxypropylene-polyoxyethylene condensate was added to the polyethersulfone resin solution. Doing so can cause the film to stretch,
The present inventors have found that they can be easily and stably peeled without being broken, and have reached the present invention.

That is, the present invention is represented by the following formula 3.
A repeating structural unit and a repeating unit represented by the following formula:
A polyethersulfone resin solution in which a polyethersulfone resin which is a copolymer composed of structural units is dissolved in a solvent is cast on a metal substrate, dried, and the formed film is peeled from the metal substrate to form a polyethersulfone resin. In the method for producing a sulfone resin film, a polyoxypropylene-polyoxyethylene condensate is added to the polyether sulfone resin solution based on 100 parts by weight of the polyether sulfone resin.
A method for producing a polyethersulfone resin film, characterized by adding 0.3 to 1 part by weight .

Embedded image (-Ph-SO _Two -Ph-O-)

Embedded image (-Ph-SO _Two -Ph-O-Ph-Ph-O-) (Ph in Formulas 3 and 4 represents a phenyl group.)

[0006]

The polyethersulfone resins to be used in the Detailed Description of the Invention The present invention, 4, 4'-dichlorodiphenyl sulfone and 4,4'-dihydroxydiphenyl sulfone and a copolymer of diphenyl compounds. Examples of the diphenyl compound include 2,2'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl, and the like.

Such a copolymer is represented by the above formula (3 ).
That having a repeating structural unit represented by the repeating structural units and the reduction 4 a copolymer.

The polyoxypropylene used in the present invention
The polyoxyethylene condensate is represented by the following formula (5).

Embedded image _{HO- (C 2 H 4 O)} a - (C 3 H 6 O) b -
_{(C 2 H 4 O) c} -H

Such a polyoxypropylene-polyoxyethylene condensate is commercially available, and can be obtained, for example, under the trade name "Pluronic F-68T" (a sales company: Asahi Denka Kogyo KK). When the condensate is added to the polyethersulfone resin in an appropriate ratio described below, phase separation in the polyethersulfone resin solution, bleed-out of the film, and coloring do not occur.

The solvent used in the present invention is one which has good solubility of the polyethersulfone resin and the polyoxypropylene-polyoxyethylene condensate and can provide a stable resin solution without causing cloudiness or gelation. It is not particularly limited. Specifically, for example, methylene chloride, 1,2-dichloroethane, trichloroethane,
1,1,2,2-tetrachloroethane, N-methyl-2
-Pyrrolidone, dimethylformamide, dimethylsulfoxide, tetrahydrofuran, chloroform and the like, and these are used alone or in combination.

The concentration of the polyethersulfone resin dissolved in the solvent is preferably adjusted so that the solution viscosity is 15 poise or more, preferably 20 poise or more. If the solution viscosity is lower than 15 poise, wind ripples and ripple-like defects are likely to occur during drying.

[0012] polyoxypropylene - amount of the polyoxyethylene condensates, against polyethersulfone 100 parts by weight, you adjust the range of 0.3 to 1 parts by weight. 0.
If the amount is less than 3 parts by weight, peeling from the metal substrate becomes difficult, resulting in inconvenience such as peeling or tearing of the film on the metal substrate. When the amount is more than 1 part by weight, the releasability of the film is good, but the transparency of the film is deteriorated, and defects such as peeling and floating of the adhesive layer at the processing stage of the film, for example, at the time of applying an adhesive. This is not preferable because it may cause

The method of casting the resin solution, drying it, and peeling off the formed film is the same as that of a usual solution casting method. Examples of the metal base material for casting the resin solution include stainless steel, iron, aluminum, and those obtained by hard chrome plating the surface of these metals and other metals. Depending on the purpose of the polyethersulfone resin film to be produced, a mirror-finished surface of the metal substrate may be used.

The casting method is not particularly limited.
A method using a lip die, a method using a doctor blade, a method using a comma coater, and the like are used.

The polyethersulfone resin solution cast on the metal substrate is usually dried by hot air to form a polyethersulfone resin film on the metal substrate. The temperature and amount of the hot air are appropriately set in consideration of the volatility of the solvent so that the film is sufficiently dried at the time when the film is peeled off from the metal substrate without causing ripples and foaming on the surface during drying. Is done. The polyethersulfone resin film peeled from the metal substrate can be further dried under appropriate drying conditions to a residual solvent amount required according to the intended use of the film.

[0016]

According to the method of the present invention, when a polyethersulfone resin film formed on a metal substrate is peeled off from the metal substrate, the film does not stretch or break, and the resulting film is obtained. In addition, it is possible to obtain a polyethersulfone resin film excellent in transparency and smoothness without occurrence of streak failure in a direction perpendicular to the casting direction. The polyethersulfone resin film obtained by the method of the present invention may be used as it is depending on the purpose, or subjected to secondary processing such as stretching, such as a cell substrate for a liquid crystal display device or a retardation film. It is useful for optical applications, electronic and electrical equipment applications, and further as interior material applications.

[0017]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The haze of the obtained film was measured using a Poick integrating sphere haze meter manufactured by Nippon Seimitsu Kogaku KK.

Reference Example 1 (Production of polyether sulfone resin) A copolymer comprising the repeating structural units represented by the above formulas (3) and (4), wherein the ratio of the repeating structural units represented by the formula (3) is 8
2.4 mol%, 1.0 g / 100 ml of N, N-
A polyethersulfone resin having a reduced viscosity of 0.38 dl / g when the dimethylformamide solution was measured at 25 ° C. using an Ostwald-type viscosity tube was produced by the following method.

A polymerization vessel equipped with a stirrer, a nitrogen inlet tube, a thermometer, and a condenser having a receiver at the end was charged with 4,4'-
Dihydroxydiphenylsulfone, 4,4′-dihydroxydiphenyl, and 4,4′-dichlorodiphenylsulfone were charged so as to be the above-mentioned repeating structural unit, and diphenylsulfone was used as a polymerization solvent in 100 parts by weight of 4,4′-dichlorodiphenylsulfone. To a weight of 160 parts by weight, and while flowing nitrogen gas through the system, add 1 part by weight.
The temperature was raised to 80 ° C. to melt the monomer. Next, 1.04 equivalents of anhydrous potassium carbonate was added to the hydroxy group of the diol component. Thereafter, the temperature was gradually raised to 290 ° C., and the reaction was further performed at 290 ° C. for 2 hours. After the completion of the reaction, the reaction solution was cooled and solidified to room temperature, pulverized finely,
After washing with warm water and washing with a mixed solvent of acetone and methanol several times, the resultant was dried by heating at 150 ° C. to obtain a desired polyethersulfone resin powder.

Examples 1 to 3 The above polyethersulfone resin was added to methylene chloride so that the concentration of the resin was 30% by weight, and a polyoxypropylene-polyoxyethylene condensate (Pluronic manufactured by Asahi Denka Kogyo KK) F-68T) was added at a weight ratio shown in Table 1 with respect to 100 parts by weight of the polyethersulfone resin, followed by stirring to obtain a resin solution. The solution viscosity at 25 ° C. of the resin solution was 25 poise. This solution is mirror-finished using a lip die to 1 mm
Cast on a stainless steel belt with hot air at 60 ° C.
After drying for minutes, the film was peeled off to obtain a polyethersulfone resin film having a thickness of 100 μm. Table 1 shows the results of the peelability of the polyethersulfone resin film from the stainless steel belt by hand and the haze value of the obtained film.

Comparative Example 1 The same procedure as in Examples 1 to 3 was carried out except that the polyoxypropylene-polyoxyethylene condensate was not added. Table 1 shows the evaluation results.

Comparative Example 2 The same procedure as in Examples 1 to 3 was carried out except that the amount of the polyoxypropylene-polyoxyethylene condensate was changed to 0.2 part by weight based on 100 parts by weight of the polyether sulfone resin. Table 1 shows the evaluation results.

Comparative Example 3 The same procedure as in Examples 1 to 3 was carried out except that the amount of the polyoxypropylene-polyoxyethylene condensate was changed to 1.5 parts by weight based on 100 parts by weight of the polyether sulfone resin. Table 1 shows the evaluation results.

[0024]

[Table 1] ：: indicates that the film was uniformly peeled. ×: indicates that there was an inconvenience such as not peeling or tearing.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08J 5/18 C08L 81/06

Claims (1)

(57) [Claims] 1. A repeating structural unit represented by the following formula :
And a repeating structural unit represented by the following formula:
Polyether sulfone resin solution a polyethersulfone resin which is a polymer dissolved in a solvent, cast on a metal substrate, after drying, the formed film was peeled off from the metal substrate preparing polyether sulfone resin film A polyoxypropylene-polyoxyethylene condensate in the polyether sulfone resin solution .
A method for producing a polyethersulfone resin film, comprising adding 0.3 to 1 part by weight to 100 parts by weight of rufone resin. ## STR1 ## _{(-Ph-SO 2 -Ph-O-} ) ## STR2 ## _{(-Ph-SO 2 -Ph-O} -Ph-Ph-O-) (Ph in the formula of 1 and formula 2 are phenyl Represents a group.)