JP2010090349A - Tubular film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tubular film excellent in light transmittance, heat resistance, mechanical strength and excellent in moldability.
SOLUTION: When a tubular film made of an aromatic polyether resin having a film thickness of 50 ± 10 μm, the total light transmittance in the JIS K7105 transparency test method is 90% or more, or the light transmittance is 400 nm. It is a tubular film characterized by being 85% or more. Preferably, the aromatic polyether resin is soluble in a non-amide and non-halogen organic solvent having a boiling point of 70 to 150 ° C. Preferably, the aromatic polyether resin has a glass transition temperature of 160 ° C. or higher by DSC (temperature rising rate 20 ° C./min).
[Selection figure] None

Description

The present invention relates to a polyether tubular film having high light transmittance, excellent heat resistance, mechanical strength, and excellent moldability. More specifically, for example, the present invention relates to a transparent tubular film that is used as a member of an electrophotographic image forming apparatus such as a copying machine, a printer, a facsimile machine, and a composite machine thereof, and is particularly suitable for use as a transparent support for a back-exposure photosensitive drum. Is.

Conventionally, metal belts and polymer film belts with high mechanical strength have been used as conveyance belts for copying machines, printers, facsimiles, and multi-function machines thereof, instead of rubber. In particular, in printing presses, printers, and the like, belts in which conductive fillers are dispersed in a polymer film and formed into a tubular material (hereinafter sometimes referred to as seamless) have been used. As a material for the polymer film, a seamless belt using a film made of polyethylene terephthalate, for example, vinylidene fluoride, ethylene / tetrafluoroethylene copolymer, polycarbonate or the like has been proposed. There has also been proposed a seamless belt made of a film having a volume resistivity of 1 to 10 ¹³ Ω · cm by blending a conductive material with a polyimide film. (See Patent Documents 1 to 4) In addition, in a seamless belt made of polyimide film, a method for improving electrical characteristics and mechanical characteristics by forming a plurality of layers and individually adjusting the electrical characteristics of each layer has been proposed. . Furthermore, in order to increase the strength, a method of reinforcing with a high-strength fiber such as polybenzobisoxazole fiber has also been proposed (see Patent Documents 5 to 7).

  On the other hand, in recent years, the development of backside exposure (backside exposure) technology has attracted attention as a new trend because electrophotographic technology has pursued sharpness of images including colorization as well as miniaturization, weight reduction, and high speed. Collecting. In this back exposure technology, a transparent electrode such as ITO (indium tin oxide) and a photoconductor layer such as a-Si (amorphous silicon) or OPC (organic photoconductor) are laminated on a cylindrical transparent support. The photosensitive member is formed, the exposure means is housed inside the photosensitive drum, and a latent image is formed by light from the inside of the drum. By accommodating an exposure power source or the like inside a tubular film having an inner diameter of 30 to 100 mm, a reduction in size and weight can be achieved, and a clear image can be obtained.

  The properties required for the transparent support are high mechanical strength as a photosensitive drum rotating body, heat resistance when forming a transparent conductive layer, chemical resistance when forming a photoconductive layer, and high light transmittance. However, conventionally proposed seamless belts are colored by themselves or additives, and are difficult to apply to these applications.

Patent Document 8 reports an example of polyimide having both mechanical strength, heat resistance, chemical resistance, and light transmittance. Usually, polyimide represented by Kapton ^R is colored from yellow to brown by charge transfer interaction. Here, the polymer was made transparent by optimizing the chemical structure of the polyimide, and the light transmission which was a problem was successfully improved.
JP-A-5-77252 Japanese Patent Laid-Open No. 5-200904 JP-A-5-345368 JP-A-6-95521 JP 7-156287 A JP 2002-156835 A JP 2001-32178 A JP 2006-152257 A

  A problem in using the transparent polyimide as a tubular film such as a seamless belt is that it is necessary to use a polyamic acid that is a precursor thereof because of insolubility of the polyimide. Usually, imidization from polyamic acid uses thermal imidization, so high temperature drying is required and the process load is high, and the film is colored by high temperature drying, and the film becomes opaque due to desorbed water (non-uniformity). Is an issue.

  An object of this invention is to provide the tubular film excellent in light transmittance, heat resistance, mechanical strength, and excellent in moldability.

  In order to achieve the above object, the present inventors have intensively studied the factors that improve transparency and molding processability, and as a result, aromatic polyethers having a specific chemical structure as a heat-resistant polymer constituting a tubular product. It was found that such a problem can be solved by using the present invention, and the present invention has been reached.

That is, the present invention provides the following [1] to [4].
[1] A tubular film made of an aromatic polyether resin, wherein the total light transmittance in the JIS K7105 transparency test method is 90% or more or the light transmittance at 400 nm is 85% or more when the film thickness is 50 μm. A tubular film characterized by being:
[2] The tubular film as described in [1] above, wherein the aromatic polyether resin is soluble in a non-amide and non-halogen organic solvent having a boiling point of 70 to 150 ° C.
[3] The tubular film as described in [1] or [2] above, wherein the aromatic polyether resin has a glass transition temperature of 160 ° C. or higher by DSC (temperature increase rate: 20 ° C./min).
[4] At least one dihalide selected from the following chemical formula (A) or chemical formula (B) or a reactive derivative thereof, and at least 2,2-bis (4-hydroxyphenyl) -1,1,1,3 A tubular film comprising an aromatic polyether obtained by reacting with bisphenol containing 3,3-hexafluoropropane.

（式（Ａ）および（Ｂ）中のＸは、それぞれ独立して、Ｆ、Ｃｌ、Ｂｒ、Ｉから選ばれる少なくとも１種の基を示す。）

(X in the formulas (A) and (B) each independently represents at least one group selected from F, Cl, Br, and I).

  Since the tubular film of the present invention is made of a heat-resistant polymer film having excellent transparency and solubility, it has high light transmittance and excellent moldability, and as a result, the process load can be reduced. It can be suitably used for back exposure (back exposure) technology using high light transmittance.

  As for the tubular film which consists of aromatic polyether resin of this invention, it is desirable that the transmittance | permeability of 400 nm is 85% in the case of film thickness 50micrometer. That is, as shown in Examples 1 and 2, the light transmittance is 85% or more not only for green and red light sources but also for light sources near blue. preferable. Furthermore, it is more preferable that it is 87% or more. Moreover, when it substitutes with a total light transmittance, it is desirable that it is 90% or more in case a film thickness is 50 micrometers. This is because when the light transmittance satisfies at least one of the above ranges, it can be suitably used for applications such as back exposure.

  The tubular film made of the aromatic polyether resin of the present invention is preferably soluble in a non-amide and non-halogen organic solvent having a boiling point of 70 to 150 ° C. When the boiling point of the solvent used in the resin solution is in the above range, there is an appropriate drying property when molding, and the surface smoothness and solvent removability are excellent. Specifically, 1,2-dimethoxyethane (boiling point: 84.5 ° C.), 1,4-dioxane (101.3 ° C.), methyl ethyl ketone (79.6 ° C.), methyl isobutyl ketone (116.2 ° C.), Preferred are ethyl acetate (88.1 ° C), isopropyl acetate (102.1 ° C), butyl acetate (116.1 ° C), propylene glycol monomethyl (90.1 ° C), propylene glycol monomethyl acetate (132.2 ° C) From the viewpoints of coating properties, safety and economy, methyl ethyl ketone and propylene glycol monomethyl acetate are preferably used. These solvents can be used alone or in combination with other solvents. Conventional heat resistant polymers represented by aromatic polyimide and polyether are difficult to satisfy this property. When the boiling point of the solvent is lower than 70 ° C., the drying may be too fast and the surface uniformity may be impaired. When the boiling point exceeds 150 ° C., the removal of the solvent becomes difficult. May be colored.

  The tubular film made of the aromatic polyether resin of the present invention preferably has a glass transition temperature by DSC (temperature increase rate 20 ° C./min) of 160 ° C. or higher, more preferably 180 ° C. or higher. If the glass transition temperature is 160 ° C. or higher, more preferably 180 ° C. or higher, thermal deformation during drying or use as a tubular film can be reduced.

  Next, the preferable raw material composition of the tubular film which consists of aromatic polyether resin of this invention is demonstrated. The first component of the essential monomer that forms the aromatic polyether of the present invention is 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane, and Examples of the second component of the essential monomer for developing the above-described properties include at least one dihalide selected from the following chemical formula (A) or chemical formula (B) or a reactive derivative thereof. The polymer obtained by reacting the first component and the second component of the essential monomer satisfies the above-described characteristics.

（式（Ａ）および（Ｂ）中のＸは、それぞれ独立して、Ｆ、Ｃｌ、Ｂｒ、Ｉから選ばれる少なくとも１種の基を示す。）

(X in the formulas (A) and (B) each independently represents at least one group selected from F, Cl, Br, and I).

  2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane used as a bisphenol component is preferably contained in an amount of 50 mol% or more in the bisphenol component, and 80 mol%. More preferably, it is contained, more preferably 90 mol% or more. As the bisphenol component, other copolymerizable bisphenol components can be used in addition to 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane. is there. Examples of the copolymerizable bisphenol component include hydroquinone, resorcinol, 2-phenylhydroquinone, 2-methylhydroquinone, 2,5-dimethylhydroquinone, 4,4′-biphenol, 3,3′-biphenol, bisphenol A, 4 , 4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylmethane, 3,3'-diaminodiphenylsulfone, 1,1'-bi-2-naphthol, 1,1'-bi -4-naphthol, 2,2-bis (2-hydroxy-5-biphenylyl) propane, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-phenylphenyl) Fluorene, 9,9-bis (4-hydroxy-3,5-diphenylphenyl) fluorene 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxy-3-methylphenyl) cyclohexane, 1,1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclohexane, etc. are used it can.

Specific examples of the compound represented by the above formula (A) include 4,4′-difluorodiphenylsulfone, 4,4′-dichlorodiphenylsulfone, 4,4′-dibromodiphenylsulfone, 4,4′- Diiododiphenylsulfone and its reactive derivatives can be used. In particular, 4,4′-difluorodiphenyl sulfone and 4,4′-dichlorodiphenyl sulfone can be suitably used from the viewpoint of reactivity.
As the compound represented by the above formula (B), specifically, 2,6-difluorobenzophenone, 2,6-dichlorolobenzophenone, 2,6-dibromobenzophenone, and reactive derivatives thereof are used. it can. In particular, 2,6-difluorobenzophenone and 2,6-dichlorolobenzophenone can be suitably used from the viewpoints of reactivity and economy.
The compound represented by the above formula (A) and the compound represented by the above formula (B) can be used in combination of two or more.

The aromatic polyether resin of the present invention can be synthesized, for example, by the method shown below.
First, in order to convert bisphenol to the corresponding alkali metal salt of bisphenol, lithium is used in a polar solvent having a high dielectric constant, such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, sulfolane, diphenylsulfone, and dimethylsulfoxide. Add alkali metals such as sodium and potassium, alkali metal hydrides, alkali metal hydroxides, alkali metal carbonates and the like. Usually, the alkali metal is reacted in excess with respect to the hydroxyl group of phenol, and usually 1.1 to 2 times equivalent is used. Preferably, 1.2 to 1.5 times equivalent is used. In this case, after preparing an alkali metal salt of bisphenol in the presence of water and an azeotropic solvent such as benzene, toluene, xylene, hexane, cyclohexane, octane, chlorobenzene, dioxane, tetrahydrofuran, anisole, phenetole, An aromatic dihalide compound substituted with a halogen atom such as fluorine or chlorine activated with an electron-withdrawing group such as A) and / or (B) is reacted. The amount of the active aromatic dihalide compound used can be changed in accordance with the molecular weight of the target polymer. Usually, the dihalide compound is reacted with bisphenol in an equal amount or in excess.
Prior to the aromatic nucleophilic substitution reaction, an alkali metal salt of bisphenol may be prepared in advance, or a metal salt may be prepared in the presence of a dihalide compound. The reaction concentration is preferably 5 to 50% by weight, more preferably 10 to 40% by weight. The reaction temperature is 60 ° C to 250 ° C, preferably 80 ° C to 200 ° C. The reaction time ranges from 15 minutes to 100 hours, preferably from 1 hour to 24 hours. The molecular weight of the aromatic polyether of the present invention is preferably 5,000 to 500,000, more preferably 15,000 to 250,000.

Isolation and purification of the aromatic polyether of the present invention can be carried out, for example, by reprecipitation, filtration, and drying under reduced pressure in a poor polymer solvent such as methanol. Examples of the solvent for dissolving the aromatic polyether of the present invention include 1,2-dimethoxyethane (boiling point: 84.5 ° C.), 1,4-dioxane (101.3 ° C.), methyl ethyl ketone (79, as described above. .6 ° C), methyl isobutyl ketone (116.2 ° C), ethyl acetate (88.1 ° C), isopropyl acetate (102.1 ° C), butyl acetate (116.1 ° C), propylene glycol monomethyl (90.1 ° C) ), Propylene glycol monomethyl acetate (132.2 ° C.) is preferably used, and methyl ethyl ketone and propylene glycol monomethyl acetate are preferably used from the viewpoints of coating property, safety and economy. These solvents can be used alone or in combination of two or more.

The polymer concentration of the solution in which the aromatic polyether of the present invention is dissolved is usually 5 to 40% by weight, preferably 7 to 25% by weight, although it depends on the molecular weight of the polymer. If it is less than 5% by weight, it is difficult to form a thick film, and pinholes are easily generated. On the other hand, if it exceeds 40% by weight, the solution viscosity is so high that it is difficult to form a film, and surface smoothness may be lacking.
The solution viscosity is usually 2,000 to 100,000 mPa · s, preferably 3,000 to 50,000 mPa · s, although it depends on the molecular weight and concentration of the polymer. If it is less than 2,000 mPa · s, the retention of the solution during film formation is poor, and it may flow from the substrate. On the other hand, when it exceeds 100,000 mPa · s, the viscosity is too high, it is difficult to adjust the film thickness, and it may be difficult to mold the tubular product.

In the method for producing a tubular film of the present invention, an aromatic polyether solution having a concentration of 5% by weight to 40% by weight is formed on a mold surface with a predetermined thickness, and then dried. The drying temperature is preferably a method of drying stepwise at a temperature of 250 ° C. or lower after drying at a temperature of about 60 ° C. A more preferable drying temperature is 230 ° C. or lower, and further preferably 210 ° C. or lower. If the drying temperature is too high, the tubular material may turn yellow and the light transmission may decrease.

At least one transparent conductive film may be further formed on at least one surface of the tubular film. The surface resistivity of the transparent conductive film is preferably 10 ¹⁰ Ω / □ or less. Examples of the transparent conductive film include an indium-tin oxide alloy, and the film thickness is preferably in the range of 50 nm to 5 μm. This conductive film can be formed by, for example, vacuum deposition, sputtering, ion plating, plasma CVD, or a coating method. Further, the film may be heat-treated (annealed) at a high temperature of 160 ° C. or higher for a relatively short time to improve transparency, heat resistance, and conductivity.

The transparent tubular product of the present invention may contain an anti-aging agent, preferably a hindered phenol compound having a molecular weight of 500 or more, and by containing an anti-aging agent, the durability as a transparent tubular product is further improved. Can do.
As a hindered phenol compound having a molecular weight of 500 or more that can be used in the present invention, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) proonate] (trade name: IRGANOX 245) 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX 259), 2,4-bis- (n- Octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -3,5-triazine (trade name: IRGANOX 565), pentaerythrityl-tetrakis [3- (3,5-di-t -Butyl-4-hydroxyphenyl) propionate] (trade name: IRGANOX 1010), 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate ] (Trade name: IRGANOX 1035), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) (trade name: IRGANOX 1076), N, N-hexamethylene bis (3.5 -Di-t-butyl-4-hydroxy-hydrocinnamamide) (IRGAONOX 1098) 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) ) Benzene (trade name: IRGANOX 1330), tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate (trade name: IRGANOX 3114), 3,9-bis [2- [3 -(3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane (trade name: Sumilizer GA-80).
In the present invention, the hindered phenol compound having a molecular weight of 500 or more with respect to 100 parts by weight of the aromatic polyether is preferably used in an amount of 0.01 to 10 parts by weight.

Since the tubular film of the present invention is made of a heat-resistant polymer film having excellent transparency and solubility, it has high light transmittance and excellent moldability, and as a result, the process load can be reduced. Furthermore, it can be used suitably for the back exposure (back exposure) technique using high light transmittance.

Hereinafter, the present invention will be specifically described by way of examples.
Example 1
To a 300 mL four-necked flask equipped with a thermometer, stirrer, nitrogen inlet tube, Dean-Stark tube, and condenser tube was added 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3. 3-Hexafluoropropane (16.81 g, 50 mmol), 4,4′-dichlorodiphenylsulfone (14.36 g, 50 mmol), potassium carbonate (7.60 g, 55 mmol), NMP 50 mL, and toluene 20 mL were added. Next, after the atmosphere in the flask was replaced with nitrogen, the resulting solution was reacted at 130 ° C., and the generated water was removed by a Dean-Stark tube. When no more water was observed, the temperature was gradually raised to 180 ° C. and reacted at that temperature for 5 hours.
After cooling to room temperature, it was poured into a large amount of methanol, and the polymer was isolated by filtration. The resulting polymer was vacuum dried at 60 ° C. overnight to give a white powder (25.3 g, 92%).
Next, the obtained polymer was redissolved in propylene glycol monomethyl acetate (PGMEA) to obtain a 20% by mass resin solution. The resin solution was applied onto a substrate made of polyethylene terephthalate (PET) using a doctor blade, dried at 80 ° C. for 30 minutes and then at 150 ° C. for 60 minutes to form a film, and then peeled off from the PET substrate. Thereafter, the film was fixed to a metal frame and further dried at 200 ° C. for 2 hours to obtain an evaluation film having a thickness of 50 μm. Moreover, the resin solution obtained here was used for formation of a tubular thing.
The obtained polymer was subjected to structural analysis and weight average molecular weight measurement by the following methods. As a result, the characteristic absorption of infrared spectrum was 1585, 1508, 1237, 1148 cm ⁻¹ , and the weight average molecular weight was 109,000.
Moreover, the solubility with respect to the organic solvent of a polymer, the total light transmittance of a film, 400 nm transmittance | permeability, a glass transition point, and molding processability evaluation were implemented with the following method. The results are shown in Tables 1 and 2.

(1) Structural analysis It was performed by IR (ATR method).
(2) Weight average molecular weight The weight average molecular weight was measured using an HLC-8020 GPC apparatus manufactured by TOSOH. The solvent was N-methyl-2-pyrrolidone (NMP) to which lithium bromide and phosphoric acid were added, and the molecular weight in terms of polystyrene was determined at a measurement temperature of 40 ° C.
(3) Solubility in organic solvents Polymers were prepared from various organic solvents (N-methylpyrrolidone (hereinafter also referred to as NMP), cyclohexanone (hereinafter also referred to as CHN), propylene glycol monomethyl ether acetate (hereinafter also referred to as PGMEA), methyl ethyl ketone. (Hereinafter also referred to as MEK) and dichloromethane (hereinafter also referred to as DCM) were adjusted to a 5 to 20% by mass solution, and the solubility at room temperature was evaluated (Table 1). In addition, when it is completely dissolved in an organic solvent (propylene glycol monomethyl ether, methyl ethyl ketone) having a boiling point of 80 to 150 ° C., which is suitable for film formation, it is “◯”, and there is a swelling or insoluble polymer. The case was designated as “x” (Table 2).
(4) Total light transmittance Measured according to JIS K7105 transparency test method. Specifically, the total light transmittance of the film was measured using an SC-3H type haze meter manufactured by Suga Test Instruments Co., Ltd.
(5) Light Transmittance The transmittance of the obtained film at a wavelength of 400 nm was measured using a JASCO V-570 UV / VIS / NIR spectrometer.
(6) Glass transition temperature (Tg)
The glass transition point of the obtained film was measured using a Rigaku 8230 type DSC measuring apparatus at a temperature rising rate of 20 ° C./min.
(7) Tensile properties The mechanical strength of the obtained film was measured according to JIS K7127.
(8) Molding workability The polymer tubular product thus obtained was produced by the following method. An aluminum cylindrical mold was used, and the aluminum mold was immersed in the polymer solution. After applying the polymer resin solution whose viscosity is adjusted so that the film thickness after drying is 50 ± 10 μm, it is pre-dried at 80 ° C. for 30 minutes and at 150 ° C. for 60 minutes. It was performed by drying at 300 ° C. for 2 hours. Molding processability was evaluated based on solubility and residual solvent amount (thermogravimetric analysis: TGA, under a nitrogen atmosphere, temperature increase rate of 10 ° C./min).

(Example 2)
A white powder was obtained (20.5 g, 94%) in the same manner as in Example 1 except that 2,6-dichlorobenzonitrile (8.60 g, 50 mmol) was used instead of dichlorodiphenyl sulfone.
The characteristic absorption of infrared spectrum of the obtained polymer was 2233, 1600, 1577, 1507, 1239, 1164 cm ⁻¹ , and the weight average molecular weight was 158,000.
Moreover, the solubility with respect to the organic solvent of a polymer, the total light transmittance of a film, 400 nm transmittance | permeability, a glass transition point, and moldability evaluation were performed like Example 1, and the result was shown in Table 1 and Table 2.

(Comparative Example 1)
Except for using 4,4′-dihydroxydiphenyl ether (10.1 g, 50 mmol) instead of 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane A white powder was obtained in the same manner as in Example 1 (19.6 g, 94%). The weight average molecular weight of the obtained polymer was 101,000.
Moreover, the solubility with respect to the organic solvent of a polymer, the total light transmittance of a film, 400 nm transmittance | permeability, a glass transition point, and moldability evaluation were performed like Example 1, and the result was shown in Table 1 and Table 2.

(Comparative Example 2)
Polyimide: 3,3′-diaminodiphenylsulfone (12.4 g, 50 mmol) was added to a 300 mL four-necked flask equipped with a thermometer, a stirrer, a nitrogen introducing tube, and a cooling tube. Next, after the atmosphere in the flask was replaced with nitrogen, N-methyl-2-pyrrolidone (hereinafter referred to as NMP) (170 ml) was added and stirred until uniform. 4,4 ″ -hexafluoroisopropylidene) bis (phthalic anhydride): 6FDA (22.2 g, 50 mmol) was added to the resulting solution at room temperature, and the reaction was continued for 12 hours at the same temperature. A solution containing polyamic acid was obtained.
The obtained solution was directly used as a resin solution, and an evaluation sample was obtained by performing thermal imidization (300 ° C., 2 hours) after film formation. The obtained imidized polymer had a weight average molecular weight of 90,000.
Moreover, the solubility with respect to the organic solvent of this imidation polymer, the total light transmittance of a film, 400 nm transmittance | permeability, a glass transition point, and a molding processability evaluation were performed like Example 1, and a result is shown in Table 1 and Table 2. Indicated.

(Comparative Example 3)
Cycloolefin polymer: a cycloolefin polymer, was used as the ARTON ^R of JSR.
Moreover, the solubility with respect to the organic solvent of this cycloolefin polymer, the total light transmittance of a film, 400 nm transmittance | permeability, a glass transition point, and a molding processability evaluation were performed like Example 1, and a result is shown in Table 1 and Table 2. Indicated. In addition, since this polymer was insoluble in the developing solvent of GPC, the molecular weight was not measured. The mold processability evaluation was uneven because the drying speed of the resin solution was too fast.

  From Table 1, it can be seen that the aromatic polyether of the present invention has excellent solubility in an organic solvent having an appropriate drying property when molded. Table 2 also shows that a tubular film is obtained without heat treatment at a high temperature (for example, about 300 ° C.), and the moldability is excellent. Moreover, it is shown that the polymer of this invention has high light transmittance, and is excellent also in heat resistance and mechanical strength (Examples 1-2). On the other hand, in Comparative Examples 1 to 3 outside the range of the present invention, the solubility is poor and the molding processability is poor. In Comparative Examples 1 and 2, there is also a problem inferior in light transmittance. Furthermore, in Comparative Example 2, heat treatment at a high temperature is necessary for imidization, and the process load is high. Moreover, in the comparative example 3, compared with Examples 1-2, it is inferior to heat resistance and dynamic strength.

Claims (4)

  It is a tubular film made of an aromatic polyether resin, and when the film thickness is 50 μm, the total light transmittance in the JIS K7105 transparency test method is 90% or more, or the light transmittance at 400 nm is 85% or more. A tubular film characterized by   2. The tubular film according to claim 1, wherein the aromatic polyether resin is soluble in a non-amide and non-halogen organic solvent having a boiling point of 70 to 150 ° C. or less. 3. The tubular film according to claim 1, wherein the aromatic polyether resin has a glass transition temperature of 160 ° C. or higher by DSC (temperature increase rate: 20 ° C./min). At least one dihalide selected from the following chemical formula (A) or chemical formula (B) or a reactive derivative thereof, and at least 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3 A tubular film comprising an aromatic polyether obtained by reacting with bisphenol containing hexafluoropropane.

(X in the formulas (A) and (B) each independently represents at least one group selected from F, Cl, Br, and I).