JP2001234069A - Aromatic polysulfone resin film, method for producing the same and solution composition for producing the film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aromatic polysulfone resin solution composition film not causing orange-peel and reduction in surface smoothness in an aromatic polysulfone resin film by a casting method, having excellent storage stability. SOLUTION: [1] This aromatic polysulfone resin solution composition comprises 10 wt.% to 50 wt.% of an aromatic polysulfone resin having 0.60-1.0 dl/g reduced viscosity. [2] The aromatic polysulfone resin solution composition comprises an aromatic polysulfone resin containing >=80 mol% of a repeating unit of the formula per molecular chain. [3] This method for producing a film comprises (1) forming a solvent-containing cast film by casting the aromatic polysulfone resin solution composition on a substrate and (2) evaporating the solvent from the cast film. [4] The method for producing the cast film comprises a process for heating the film at a temperature equal to or higher than Tg of the aromatic polysulfone resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an aromatic polysulfone resin film, a method for producing the same, and a solution composition for producing the same.

[0002]

2. Description of the Related Art Aromatic polysulfone resin films have excellent properties such as mechanical strength, electrical properties, transparency, heat resistance, chemical resistance, and flame retardancy. It is used for retardation films. As a method for producing an aromatic polysulfone resin film by a casting method, a method disclosed in the following patent publication is known. JP-A-6-7936 describes a method for producing a polysulfone-based resin film by casting and drying a polysulfone-based resin solution having a water content of 0.2% by weight or less. In addition, Japanese Patent Application Laid-Open No. 7-248
Japanese Patent Application Publication No. 58-58 describes a method for producing a polysulfone resin film from an acetophenone solution or an N-methylpyrrolidone solution of a polysulfone resin by a solution casting method. Further, JP-A-7-300559 discloses
A method for producing a cast film of aromatic polyethersulfone having excellent surface properties, transparency and homogeneity by using 1,3-dioxolane is described. When an aromatic polysulfone resin film is produced by a casting method, if the viscosity of an aromatic polysulfone resin solution for casting (hereinafter sometimes referred to as a dope) is low, convection occurs on a wet film at an initial stage of drying. There is a problem that orange peel is generated due to the above, and the surface smoothness is reduced. In order to solve this, it is necessary to increase the viscosity of the dope and increase the viscosity, but this has caused a problem that the storage stability of the dope is reduced.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an aromatic polysulfone resin solution composition, in which an orange peel is generated on an aromatic polysulfone resin film produced by a casting method using the composition. It is an object of the present invention to provide an aromatic polysulfone resin solution composition which does not lower the surface smoothness and has good storage stability, an aromatic polysulfone resin film using the composition, and a method for producing the same.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that when producing an aromatic polysulfone resin film by a casting method, a dope containing a specific amount of an aromatic polysulfone resin having a specific reduced viscosity is used. Thus, the present inventors have found that the above problems can be solved and completed the present invention. That is, the present invention relates to [1] an aromatic polysulfone resin solution composition containing 10 to 50% by weight of an aromatic polysulfone resin having a reduced viscosity of 0.60 to 1.0 dl / g.
Further, the present invention relates to [2] the aromatic polysulfone resin solution composition according to [1] above, wherein the aromatic polysulfone resin contains the following repeating structural unit per molecule chain in an amount of 80 mol% or more.

Embedded image Further, the present invention provides [3] (1) casting the aromatic polysulfone resin solution composition of the above [1] or [2] on a support to form a casting film containing a solvent, (2) The present invention relates to a method for producing an aromatic polysulfone resin film by evaporating a solvent from the cast film. Next, the present invention
[4] Glass transition temperature of aromatic polysulfone resin (T
g) A method for producing an aromatic polysulfone resin film according to the above [3], including a step of heating at the above temperature. Next, the present invention relates to [5] the aromatic polysulfone resin film produced by the above method [3] or [4].

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the present invention, the aromatic polysulfone resin is
An arylene unit is a polyarylene compound in which three members of an ether bond and a sulfone bond are essential repeating structural units, and the arylene unit is located randomly or orderly together with the ether and the sulfone bond. As the aromatic polysulfone resin used in the present invention, for example,
A resin containing a structure consisting of a repeating structural unit represented by the following general formula (I), a resin containing a structure represented by (II),
Or a resin having the structure represented by (III).

[0006]

Embedded image ... (I) [In the formula (I), R ₁ represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 10 carbon atoms, a phenyl group or a halogen atom, and p is an integer of 0 to 4. . Each R ₁ on the same or different nuclei may be different from each other. Each p may be different from each other. ]

[0007]

Embedded image ... (II) [In the formula (II), R ₁ represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 10 carbon atoms, a phenyl group or a halogen atom, and p is an integer of 0 to 4. . m and n indicate the average number of repeating structural units, and m and n are positive numbers from 0.1 to 100. Each R ₁ on the same or different nuclei may be different from each other. Each p may be different from each other. ]

[0008]

Embedded image ... (III) [In formula (III), R ₁ represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 10 carbon atoms, a phenyl group or a halogen atom, and p is an integer of 0 to 4. . m and n indicate the average number of repeating structural units, and m and n are positive numbers from 0.1 to 100. Each R ₁ on the same or different nuclei may be different from each other. Each p may be different from each other. Each q may be different from each other. ]

The structures represented by the above formulas (I) and (II) represent block copolymers. In the present invention, a random copolymer or an alternating copolymer containing each repeating structural unit is used. Shall also be indicated.

As the aromatic polysulfone resin used in the present invention, (m / m + n) in the structure represented by (II) or (III) is preferably 0.8 or more. Further, q in the structure of (III) is preferably 1.

Among these, a resin having a structure comprising a repeating structural unit represented by (I) and a resin having a structure represented by (II) are preferable, and more preferably a resin having a structure comprising a repeating unit represented by (I) It is a resin including a structure. Among resins containing a structure consisting of repeating structural units of (I), those having all p's of 0, that is, resins containing a structure consisting of repeating structural units represented by the following formula, are more preferable. A resin containing a repeating structural unit represented by the following formula at 80 mol% or more is particularly preferred.

[0012]

Embedded image Further, the aromatic polysulfone resin used in the present invention may contain, for example, the repeating structural units shown in the examples (IV) to (Vl) in addition to the above-mentioned structure.

Embedded image …… (IV)

Embedded image …… (V)

Embedded image (Vl) (In the formula (Vl), X represents an organic group having 1 to 20 carbon atoms, a divalent sulfur atom or an oxygen atom.) Here, as the organic group having 1 to 20 carbon atoms, for example, Examples include an isopropylidene group and an ethylidene group.

The molecular weight of the aromatic polysulfone resin used in the present invention is represented by using a reduced viscosity as a measure thereof, and the value is in a range of 0.60 to 1.0 dl / g, preferably 0.60 to 1.0 dl / g. 0.90 dl / g, more preferably 0.70 dl / g to 0.80 dl / g. If the resin is less than 0.60 dl / g, it is difficult to obtain a stable dope suitable for casting.
If it exceeds g, not only is it difficult to obtain the resin, but also the solubility of the resin decreases. In the present invention, the reduced viscosity is 10
After dissolving 1 g of aromatic polysulfone in 0 cm ³ of N, N-dimethylformamide, the viscosity of this solution was increased to 25%.
It is a value measured at ° C.

The solvent used in the dope of the present invention includes amides such as N-methyl-2-pyrrolidone, N, N-dimethylformamide and N, N-dimethylacetamide; sulfoxides such as dimethyl sulfoxide; cresol; Phenols; halogenated carbons such as methylene chloride; esters such as γ-butyrolactone;
And other good solvents for aromatic polysulfone resins. These solvents may be used alone or in combination of two or more. If necessary, aromatic hydrocarbons such as toluene and xylene; ketones such as methyl ethyl ketone, methyl isobutyl ketone, acetone and cyclohexanone; alcohols such as methanol and ethanol; water; poor solvents for aromatic polysulfone resins such as water Can be added to a good solvent. The mixing ratio varies depending on the concentration of the dope, storage stability, drying conditions after casting on the support, and the like, but the ratio of good solvent / poor solvent is preferably 1/3 or more. The concentration of the aromatic polysulfone resin in the dope of the present invention is 10% by weight to 50% by weight, and 20% by weight to 4% by weight.
It is preferably 0% by weight. When the concentration is less than 10% by weight, the effective concentration is low, and particularly in the case of a thick film, an orange peel occurs due to convection in the film at an early stage of drying, and the surface smoothness is reduced. In addition, 50% by weight
At the above concentration, the dope gels due to crystallization of the aromatic polysulfone resin during storage and the like, resulting in poor stability, and furthermore, in this region, the dope has high viscosity, resulting in poor filterability.

In the dope of the present invention, if necessary,
Additives such as leveling agents and plasticizers can also be blended. As the leveling agent, acryl-based, silicone-based, and fluorine-based agents can be used. As the plasticizer, a plasticizer that has good compatibility with the aromatic polysulfone resin, does not cause phase separation or bleed-out, and does not cause coloring is preferable. For example, phthalic acid, phosphoric acid, adipic acid, citric acid, glycolic acid and the like plasticizers, butylbenzyl phthalate, tricresyl phosphate,
Methylphthalylethyl glycolate and the like are preferably used.

In the production method of the present invention, the compound such as the above-mentioned aromatic polysulfone resin and solvent are mixed and dissolved,
After preparing the aromatic polysulfone resin solution composition (dope), (1) the dope is flowed onto an endless band or a support on a drum by a comma coater, lip coater, doctor blade coater, bar coater, roll coater or the like. And forming a casting film containing a solvent.
(2) and evaporating the solvent from the casting film,
Form a film. The solvent is preferably evaporated by heating in order to improve the efficiency of the evaporation. The heating temperature may be constant or may be varied as needed.

Further, in the production method of the present invention, in order to make the film optically isotropic, it is more preferable to include a step of heating at a temperature higher than the glass transition temperature (Tg) of the aromatic polysulfone resin. The step of heating at a temperature equal to or higher than the glass transition temperature (Tg) may be performed in the step of evaporating the solvent, or may be different from the step of evaporating the solvent.

The formed film is peeled off from the support to obtain a continuous long aromatic polysulfone resin film. A short aromatic polysulfone film can also be obtained by a batch method using a sheet-like support.

There are various uses of the aromatic polysulfone resin film thus produced. For example, in the field of electrical insulation, H-class electrical equipment, slot liners for motors and generators, insulating materials such as phase-to-phase insulation, and wrapping for transformers and wires coated with adhesives and adhesives and processed into tapes It can be used for materials, dielectric films such as capacitors, and tubular insulating materials. In the electronics-related field, it can be used for flexible printed circuit boards and their reinforcing plates, heat-resistant spacers, PCB laminates, and the like. In the acoustic-related field, it can be used for diaphragms and vibration reinforcing plates of speakers. In the information-related field, it can be used for recording tapes, disks, and glass substrate replacement films for liquid crystal displays that require dimensional stability, as well as for connection parts of retardation films and optical fibers by being stretched. In the food and medical fields, it can be used for medical sterilization equipment and heating packs for microwave ovens and microwave ovens.

[0020]

EXAMPLES Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 Sumika Excel PES7600P (manufactured by Sumitomo Chemical Co., Ltd., polyether sulfone, reduced viscosity 0.76d)
1 / g) in N, N-dimethylformamide to prepare an aromatic polysulfone resin solution having a solid content of 25% by weight (hereinafter abbreviated as dope). This dope was cast on a glass plate using a bar coater (clearance: 500 μm), placed in a heating oven at 100 ° C., and left for 10 minutes. After that, when observing the surface condition of the film,
A good surface free of orange peel was obtained.
No significant change in the viscosity of the dope was observed during the production and casting operations of the dope, and the dope had good stability.

Example 2 Sumika Excel PES7600P (manufactured by Sumitomo Chemical Co., Ltd., polyether sulfone, reduced viscosity 0.76d)
1 / g) was dissolved in N, N-dimethylformamide to prepare a dope having a solid content of 30% by weight. This dope was cast on a glass plate using a bar coater (clearance: 500 μm) and placed in a heating oven at 100 ° C.
Let stand for minutes. Thereafter, when the surface state of the film was observed, a good surface free of orange peel was obtained. No significant change in the viscosity of the dope was observed during the production and casting operations of the dope, and the dope had good stability.

Comparative Example 1 Sumika Excel PES5200P (manufactured by Sumitomo Chemical Co., Ltd., polyether sulfone, reduced viscosity 0.52d)
1 / g) was dissolved in N, N-dimethylformamide to prepare a dope having a solid concentration of 25% by weight. This dope was cast on a glass plate using a bar coater (clearance: 500 μm) and placed in a heating oven at 100 ° C.
Let stand for minutes. Thereafter, when the surface state of the film was observed, orange peel was generated on the entire surface. 520
Although 0P had a lower reduced viscosity than 7600P, the viscosity of the dope was higher than that of the dope described in Example 1, and signs of gelation were observed.

Comparative Example 2 Sumika Excel PES5200P (manufactured by Sumitomo Chemical Co., Ltd., polyether sulfone, reduced viscosity 0.52d)
1 / g) was dissolved in N, N-dimethylformamide to prepare an aromatic polysulfone resin solution having a solid content of 30% by weight. This solution was applied to a bar coater (clearance 50
(0 μm), and cast in a heating oven at 100 ° C. for 10 minutes. Thereafter, when the surface state of the film was observed, orange peel was generated on the entire surface. Although the reduced viscosity of 5200P was lower than that of 7600P, the viscosity of the dope was higher than that of the dope described in Example 2, and a sign of gelation was observed.

[0025]

[Table 1]

[0026]

EFFECT OF THE INVENTION The aromatic polysulfone resin solution composition of the present invention has good storage stability, and the aromatic polysulfone resin film produced by the casting method using the composition produces orange peel, There is no problem that the smoothness is reduced.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F071 AA64 AA88 AE19 AH12 BA02 BB02 BC01 4J002 CN031 FD020 GB00 GG00 GP00 GQ00 GS00 HA05

Claims (5)

[Claims] 1. An aromatic polysulfone resin solution composition comprising 10 to 50% by weight of an aromatic polysulfone resin having a reduced viscosity of 0.60 to 1.0 dl / g. 2. The aromatic polysulfone resin solution composition according to claim 1, wherein the aromatic polysulfone resin contains at least 80 mol% of the following repeating structural units per molecular chain. Embedded image (3) The aromatic polysulfone resin solution composition according to (1) or (2) is cast on a support to form a cast film containing a solvent. A method for producing an aromatic polysulfone resin film, comprising evaporating a solvent. 4. The method for producing an aromatic polysulfone resin film according to claim 3, further comprising the step of heating at a temperature higher than the glass transition temperature (Tg) of the aromatic polysulfone resin. 5. An aromatic polysulfone resin film produced by the method for producing an aromatic polysulfone resin film according to claim 3 or 4.