JPH11292999A - Polyaryl ether ketone film and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject film exhibiting stable surface resistivity in a semiconductive range owing to the small fluctuation of the surface resistivity and useful for a charged roll for electrophotography, or the like, by uniformly dispersing a specific amount of an electrically conductive filler in a polyaryl ether ketone and molding the product. SOLUTION: The objective polyaryl ether ketone film having a surface resistivity of 10-13 (logΩ/cm<2> ) and a standard deviation of the surface resistivity of 0.05-0.2 is composed of (A) 100 pts.wt. of a polyaryl ether ketone (e.g. a polymer containing the recurring units of formula I, formula II or formula III and having an average particle diameter of 0.1-3 mm) and (B) 3-70 pts.wt. of an electrically conductive filler (e.g. carbon black). The film can be produced e.g. by mixing the component A and the component B at a prescribed ratio, kneading and melting the obtained resin composition at 350-420 deg.C and molding it in the form of a film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polyaryletherketone film and a method for producing the same. Specifically, the present invention relates to a polyaryletherketone film containing a conductive filler and a method for producing the same, which has a good surface condition, a small variation in surface resistivity, and a uniform charging performance.
The present invention relates to a polyaryletherketone film suitable as a semiconductive film and a method for producing the same.

[0002]

2. Description of the Related Art In an image forming apparatus using an electrophotographic method such as a multifunction device such as an electrophotographic copying machine, a laser printer, and a facsimile, functional parts include a charging roll, a transfer belt, and a toner carrying roll. black,
A film having a surface resistivity of about 10 to 13 (logΩ / □) in which a conductive filler such as graphite, metal powder, and metal oxide powder is dispersed in a resin has been used. However, conductive fillers such as carbon black, graphite, metal powder and metal oxide powder are dispersed in a resin,
A semiconductive film having a stable surface resistivity in a semiconductive region of about 3 (log Ω / □) has an extremely nonuniform surface resistivity, and its variation is often several orders of magnitude. However, such a case has a practical problem.

Further, polyethylene terephthalate, polycarbonate, polyarylate, polyethersulfone and the like are often used as resins. For example, JP-A-7-161224 discloses an amorphous copolyester in which the dicarboxylic acid component is mainly terephthalic acid and the diol component is mainly ethylene glycol, and the total amount of the copolymer components is 20 mol% or more. A conductive sheet for a contact-type charging electrode comprising a composition containing 10 to 20% by weight of conductive carbon black is disclosed. In this publication,
It is disclosed that the amorphous copolymerized polyester was found to have a smaller variation in electric resistance value when the conductive carbon black was dispersed as compared with a normal crystalline polyester-based resin. However, the conductive sheet has a high hygroscopicity due to the use of an amorphous resin, and the surface resistivity tends to fluctuate greatly due to environmental fluctuations such as temperature and humidity and deterioration over time. There is.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyaryletherketone film which has a good surface condition and a small variation in surface resistivity and is suitable as a semiconductive film, and a method for producing the same. .

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies in order to achieve the above object, and as a result, have found that the average particle size within a specific range, such as mechanical strength, heat resistance, chemical resistance, and moisture absorption resistance. A film obtained by uniformly dispersing a specific amount of conductive filler in polyaryl ether ketone with excellent properties and molding under specific molding conditions has good surface condition and small variation in surface resistivity The present invention has been found to be suitable as a semiconductive film. That is, in the present invention, the average particle diameter of the polyaryletherketone is 0.1 to 3 m.
m to 100 parts by weight of the powder or the pulverized powder, 3 to 70 parts by weight of a conductive filler is mixed using a mixer, and the obtained resin composition is pelletized using a twin-screw kneading extruder. The pellets were extruded using an extruder.
A polyaryletherketone film and a method for producing the polyaryletherketone film, wherein the film is kneaded at 50 to 420 ° C., melted, extruded from a die while being filtered, cooled by a cooling roll and shaped into a film.

The polyaryletherketone film obtained by the present invention contains a specific amount of a conductive filler, exists in a semiconductive region having a surface resistivity of 10 to 13 (logΩ / □), and has a standard deviation of 0. 0.05 to 0.2, and excellent surface smoothness. Therefore, electrophotographic copying machines,
Laser printers, facsimile machines, charging rolls of image forming apparatuses using electrophotographic methods such as composite machines,
10 to 13 (l
It is extremely useful as a film to be used as a material having a stable surface resistivity of about (.omega ./. OMEGA./.quadrature.).

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION According to the present invention, a specific amount of a conductive filler is added to and mixed with a powdery polyaryletherketone having an average particle diameter within a specific range, and the obtained resin composition is pelletized. A polyaryletherketone film formed under specific conditions using an extruder and a method for producing the same. Hereinafter, the present invention will be described in detail. As the polyaryletherketone used in the present invention, a compound represented by the formula (1):

[0008]

Embedded image Formula (2) [Formula 8],

[0009]

Embedded image And formula (3)

[0010]

Embedded image Is a polyaryletherketone having at least one type of repeating structural unit.

The polyaryletherketone having a repeating structural unit represented by the above formula (1) includes polyetheretherketone (hereinafter, referred to as PEEK). Examples of commercially available products include “Victrex-PEEK” (trade name, manufactured by ICI, UK). Examples of those having a repeating structural unit represented by the above formula (2) include polyether ketone (hereinafter, referred to as PEK). As a commercially available product, for example, there is a product name “Victrex-PEK” manufactured by ICI UK. Examples of those having a repeating structural unit represented by the above formula (3) include polyether ketone ether ketone ketone (hereinafter, referred to as PEKEKK). As a commercially available product, for example, trade name “Ultra” manufactured by BASF, Germany
pek ”and the like. These may be used alone or as a mixture of two or more.

The average particle size of the polyaryletherketone used in the present invention is 0.1 to 3 mm, preferably 0.5 to 2 mm. If the average particle size exceeds 3 mm, the conductive filler is not sufficiently dispersed in the resin, so that the surface resistivity becomes extremely non-uniform in the film surface, and the variation often rises to several orders of magnitude, resulting in high quality.
This is extremely unsatisfactory for a transfer belt or the like of an image forming apparatus requiring high performance. When the thickness is less than 0.1 mm, when the raw material is supplied to a Henschel mixer, a universal mixer, a ribbon blender, or the like, the raw material is scattered around and a desired surface resistivity cannot be obtained, thereby lowering the production yield.

The conductive filler used in the present invention is not particularly limited as long as it exhibits conductivity, and examples thereof include fine powders of carbon black, zinc oxide, titanium oxide, silver oxide, potassium titanate and the like. These mixtures may be used, and carbon black is preferable. The particle size of the conductive filler is not particularly limited, but it is possible to remove contaminant foreign substances and so-called gel-like substances that have stayed in the extruder for a long time and have a high molecular weight, and further improve the dispersibility of the conductive filler, or In order to prevent the occurrence of poor appearance of the film due to agglomeration of the filler, the filtration diameter of the cylindrical or disk-shaped filter installed between the tip of the cylinder of the extruder and the T-die etc. (Opening) is preferably smaller.
The shape of the conductive filler is not particularly limited, and may be powdery, granular, acicular, or elliptical. Further, additives, lubricants, dispersants, plasticizers, flow improvers and the like may be added as long as the effects of the invention are not significantly impaired.

The content of the conductive filler is 3 to 70 parts by weight, preferably 10 to 40 parts by weight, based on 100 parts by weight of the polyaryletherketone. If less than 3 parts by weight,
If the toner does not exhibit sufficient semiconductivity or has a variation in charge amount, and is used as a belt for electrostatically carrying toner in an image forming apparatus, an image defect is caused, which is not preferable. On the other hand, if it exceeds 70 parts by weight, the conductivity is too high, the charge amount is reduced, and there is a problem in moldability.

Next, a method for obtaining a film comprising the polyaryletherketone of the present invention and a conductive filler will be described. The polyaryl ether ketone and the conductive filler are mixed using a Henschel mixer, a universal mixer, a mixer such as a ribbon blender,
The obtained resin composition is pelletized using a twin-screw kneading extruder or the like, and the pellets are further kneaded using a melt extrusion molding machine or the like, melted and extruded from a T-die or the like, and then cooled using a cooling roll or the like. Examples of the method include cooling and shaping into a film.

The temperature for pelletizing is not particularly limited,
Usually, it is 330-400 ° C. The temperature of the extruder during film formation is preferably from 350 to 420 ° C. When the temperature of the extruder is lower than this range, the melt viscosity of the resin is too high, and the pressure in the narrow flow path such as the filter or T-die rises abnormally, and the extruder motor is overloaded, resulting in extrusion. May be disabled. Also,
If the temperature is higher than this range, gelling of the resin occurs,
If the temperature is higher, the resin is decomposed, and the surface condition of the film is not only deteriorated by the so-called fish eyes or so-called uneven flow, but also as the molding time elapses, the viscosity increases and the load increases. Extrusion molding tends to be impossible.

In addition, removal of so-called gel-like substances, which are contaminated and stay in the extruder for a long time and have a high molecular weight in the extruder, further improve the dispersibility of the conductive filler, or impair the appearance of the film due to aggregation of the conductive filler. For the purpose of preventing the occurrence of the like, it is preferable to install a cylindrical or disk-shaped filter between the tip of the cylinder of the extruder and the T-die or the like. Filtration diameter of filter (aperture)
Is usually 10 to 80 μm. If the filtration diameter (opening) of the filter is smaller than 10 μm, the pressure rise of the resin in the extruder becomes large, and the motor is overloaded, so that the extruder may not be able to be formed. When it is larger than 80 μm, effects such as removal of a so-called gel-like substance and improvement in dispersibility of a conductive filler are reduced. Filtering treatment with a filter improves the dispersibility of the conductive filler, and also eliminates the appearance of fish eyes such as foreign substances, gels, or aggregates of the conductive filler on the surface of the obtained film in the form of projections. When the obtained film is used, for example, as a transfer belt in an image forming apparatus, the image is not disturbed.

The film discharged from a T-die or the like is cooled and solidified by using a cooling roll and shaped into a film. The surface temperature of the cooling roll is usually 200 to 250 ° C.
And preferably at 210 to 230 ° C. Since the polyaryl ether ketone shows the maximum value of the crystallization rate at about 230 ° C., outside this range, the crystallization rate of the polyaryl ether ketone is slow, the crystallization is incomplete, and the obtained film has a glass transition temperature. At about 150 ° C. or more, the elastic modulus sharply decreases and the heat resistance becomes poor.

The polyaryletherketone film produced by the method of the present invention is formed into, for example, a tube or a belt to form a transfer belt. There is no particular limitation on the method of forming the film into a tube shape or the like.
A simple method such as a method of heating and pressure bonding and a method of setting the inside of a cylindrical mold and then fusing the connecting portion using ultrasonic waves can be applied.

The polyaryletherketone film obtained according to the present invention contains a specific amount of a conductive filler, exists in a semiconductive region having a surface resistivity of 10 to 13 (logΩ / □), and has a standard deviation of 0. 0.05 to 0.2, and excellent surface smoothness. Therefore, electrophotographic copying machines,
Laser printers, facsimile machines, charging rolls of image forming apparatuses using electrophotographic methods such as composite machines,
10 to 13 (l
It is extremely useful as a film used as a material having a stable surface resistivity of about (.omega ./. OMEGA./.quadrature.) and a method for producing the film.

The polyaryletherketone film obtained by the present invention can be used as a charge roll in an image forming apparatus using an electrophotographic method, such as a high-quality electrophotographic copying machine, laser printer, facsimile, or a composite machine thereof.
It can be used as a transfer belt and a roll carrying toner.

[0022]

The present invention will be described in more detail with reference to the following examples. The method for measuring the characteristic values of the polyaryletherketone films described in the examples and comparative examples is described below. (1) Surface resistivity (Ω / □) For a square sample having a side of 30 cm, a temperature of 23
℃, relative humidity 50%, surface resistance meter Hiresta H
Using A probe (Mitsubishi Chemical), measurement voltage 100V,
Fifteen points were measured at a measurement time of 10 seconds, and the average value was displayed as a logarithmic value. The standard deviation was determined from the numerical values. (2) Surface accuracy (pieces) The entire surface of a square sample having a side of 30 cm was observed using a loupe (magnification: 25 times), and the size was 0.2 mm.
The number of the above-mentioned projecting fish eyes was measured.

Example 1 "Victrex P" manufactured by ICI and having an average particle diameter of 0.8 mm
100 parts by weight of EEK-380G ”and carbon black [Colduan Carbon Co., Ltd., trade name: Condu
ctex 975: average particle diameter 0.021 μm] was mixed with a Henschel mixer, kneaded at 330 to 350 ° C. using a twin-screw extruder, melted, extruded and granulated to obtain pellets. The obtained pellet is 50 mm in diameter.
To a single-screw extruder (molding temperature: 410 ° C.) through a leaf disc type filter having a filtration diameter (opening) of 40 μm attached between the tip of the extruder cylinder and the front of the T-die, and having a width of 1100 mm It was extruded from a T-die and cooled, solidified and shaped by a cooling roll (φ400 mm) having a surface temperature of 220 ° C. to obtain a 150 μm-thick polyaryletherketone film. Type and average particle size of polyaryl ether ketone used, type and amount of conductive filler, extrusion temperature during film formation, surface resistivity and standard deviation of obtained polyaryl ether ketone film, surface accuracy Are shown in Table 1 [Table 1].

Examples 2 to 5 and Comparative Examples 1 to 7 Table 1 shows the types and average particle diameters of the polyaryletherketones used, the types and amounts of conductive fillers, and the extrusion temperatures at the time of film formation. A polyaryletherketone film having a thickness of 150 μm was obtained in the same manner as in Example 1 except for the change as described in Table 1]. Example 2
PEK manufactured by ICI, trade name: Victrex PEK-220P was used in Example 3.
KK is manufactured by BASF, trade name: Ultrapek-A
The PEEK used in Examples 4 and 5 and Comparative Examples 1 to 5 was the same as that used in Example 1, and the potassium titanate whisker used in Example 4 was manufactured by Otsuka Chemical Co., Ltd. , Trade name: Dentol, particle diameter: major axis 10
Examples 2 and 3
The carbon black used in Comparative Examples 1 to 5 was the same as that used in Example 1, and the carbon black used in Example 5 was manufactured by Lion Oil & Fat Co., Ltd., trade name:
Ketjen Black EC, average particle diameter 0.03 μm was used. The amount of the conductive filler is based on 100 parts by weight of the polyaryletherketone. Table 1 [Table 1] shows the surface resistivity, standard deviation, and surface accuracy of the polyaryletherketone films obtained in each example.

[0025]

[Table 1]

Discussion of Examples The films obtained in Examples 1 to 5 all have a surface resistivity in the range of 10 to 13 (log Ω / □) and a standard deviation of 0.05 to 0. 2 is shown. Therefore, the obtained polyaryletherketone film is used as a charging roll, a transfer belt, and a toner-carrying roll in an electrophotographic image forming apparatus such as an electrophotographic multi-function printer, a laser printer, a facsimile, or a composite device thereof. Is extremely useful. On the other hand, the film obtained in Comparative Example 1 had a large average particle size of the polyaryletherketone and a large standard deviation of the surface resistivity of 0.382, indicating a stable surface resistivity in the film plane. If it is used as a charging roll, a transfer belt, or a toner-carrying roll in an electrophotographic image forming apparatus such as an electrophotographic copying machine, a laser printer, a facsimile, or a combination of these devices, an image defect occurs. It is not possible to use it because it is considered that this occurs.

The film obtained in Comparative Example 2 or Comparative Example 3 had a surface resistivity outside the semiconductive region because the amount of the conductive filler was too small or too large.
It has become unsatisfactory as a charging roll, a transfer belt, and a toner-carrying roll in an image forming apparatus such as an electrophotographic copying machine or a laser printer. In Comparative Example 4, since the extrusion temperature was low, the melt viscosity of the resin was high and the motor of the extruder was overloaded, the rotation of the screw was stopped, and extrusion was impossible. In Comparative Example 5, extrusion was possible because the extrusion temperature was too high, but a large number of gels were present on the surface of the obtained film. Also, two hours after the start of the extrusion, the motor of the extruder was overloaded, the rotation of the screw was stopped, and the extrusion became impossible. The resulting film has a rough surface, which may cause image defects. Therefore, the film is used as a functional part such as a charging roll, a transfer belt, and a toner carrying roll in an image forming apparatus such as an electrophotographic copying machine or a laser printer. Is not possible.

[0028]

According to the method of the present invention, the surface condition is good, the variation of the surface resistivity is small, and
A polyaryletherketone film suitable for a semiconductive film having a stable surface resistivity in a semiconductive region of about gΩ / □) can be obtained. The film can be suitably used as a charging roll, a transfer belt, and a toner-carrying roll in an electrophotographic image forming apparatus such as an electrophotographic copying machine, a laser printer, a facsimile, or a composite device thereof.

Claims (4)

[Claims] 1. A polyaryletherketone (100 parts by weight) containing a conductive filler (3 to 70 parts by weight), a surface resistivity of 10 to 13 (logΩ / □), and a standard deviation of the surface resistivity. Is from 0.05 to 0.2. 2. The polyaryletherketone is represented by the formula (1): ## STR1 ## Formula (2) [Formula 2], And formula (3) The polyaryletherketone film according to claim 1, wherein the film has at least one kind of repeating structural unit represented by the following formula: 3. A resin composition comprising 350 to 4 parts by weight of a conductive composition in which 3 to 70 parts by weight of a conductive filler is mixed with 100 parts by weight of a polyaryl ether ketone having an average particle diameter of 0.1 to 3 mm.
A method for producing a polyaryletherketone film which is kneaded and melted at 20 ° C. to form a film. 4. The polyaryletherketone is a compound represented by the formula (1): Formula (2) [Formula 5], And formula (3) [Formula 6] The method for producing a polyaryletherketone film according to claim 3, wherein the method has at least one kind of repeating structural unit represented by the following formula: