JPH0728268A - Electrophotographic film - Google Patents

Abstract

PURPOSE:To provide an electrophotographic film hardly varying its surface electric resistance even under an environmental change, especially a considerable humidity change, exhibiting superior transferability at the time of copying, giving a high density image, less liable to cause triboelectric charge in a working process or during handling even at low humidity, excellent in conveyability and also excellent in scuffing resistance. CONSTITUTION:In an electrophotographic film obtd. by providing an image receiving layer 12 having 1X10<9>-1X10<13>OMEGA surface electric resistance at 25 deg.C and 65% relative humidity on at least one side of a transparent substrate 11, the image receiving layer 12 is composed of fine particles of an electric conductive metal oxide having <=0.1mum average particle diameter, a matting agent of a lubricative resin and a polymer. The objective electrophotographic film is obtd.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a transparent electrophotographic film suitable for producing a transparent image by using an electrophotographic copying machine for plain paper. In particular, it relates to an electrophotographic film that can be used in an OHP (overhead projector).

[0002]

2. Description of the Related Art In electrophotography, generally, the surface of a photoconductor is charged, a latent image of an electrostatic image is formed by exposure, toner is attached to the latent image for development, and the toner image is transferred onto a transfer paper. The toner image can be obtained by fixing and fixing the toner image with heat or pressure. Such a method using transfer paper (plain paper) is called an indirect method of electrophotography, and is used in a general electrophotographic copying machine for plain paper. A method in which the paper itself also functions as a photoconductor, that is, paper having a photosensitive layer (Z
nO coated paper), a latent image is directly formed, toner development,
There is also a fixing method, which is said to be the direct method of electrophotography. Using the indirect method electrophotographic copying machine for plain paper,
When creating a transparent image using electrophotographic film (hereinafter also referred to as transparent film) instead of plain paper, that is, copying, unlike the case where plain paper is used, film transport error (misfeed, double feed), cloudiness Various problems such as (haze), abrasion damage during handling, poor adhesion of the toner image, and generation of embossed marks by the heating roll occur.

Conventionally, a layer having a controlled surface electric resistance has been formed on a transparent plastic film in order to improve the transferability of the toner and the transportability of the film, especially during copying. JP-B-51-34734 discloses that a surface specific resistance value in which a resin layer soluble in an organic solvent containing a matting agent (inorganic fine particles and plastic powder) is formed on a plastic film is 1 × 10 ⁹ to 1 × 10.
^{A 15} Ω electrophotographic film is disclosed. This resin layer has a good toner transfer property to some extent at normal humidity, but at low humidity it is a resin layer that is soluble in organic solvents, so resistance increases and double feeding easily occurs. Therefore, the toner transferability is deteriorated. That is, when a resin soluble in an organic solvent is used, the resistance value can only be controlled by a surfactant or the like, which is not sufficient.

Further, Japanese Patent Publication No. 59-42864 discloses an electron consisting of two layers in which an undercoat layer of an anionic or cationic conductive resin and a receiving layer (image receiving layer) of an acrylic resin are sequentially formed on a film. Further, a photographic film is disclosed in JP-A-62-238526, which is an electrophotographic film having an undercoat layer containing an organic salt for imparting conductivity and an image receiving layer of polymethylmethacrylate provided on the film. Proposed. When an ion conductive substance is used in the undercoat layer as described above, the surface electric resistance of the film surface is lowered, but since this surface electric resistance is easily affected by the water absorption amount of the undercoat layer, the surface electric resistance is greatly affected by a change in environmental humidity. However, there is a problem that the toner fluctuates, and the resistance is lowered particularly under high humidity to lower the transferability of the toner.

On the other hand, various materials using fine particles of metal oxides have been proposed in the field of electrostatic recording paper (materials) as a method for stably obtaining surface electric resistance. The electrostatic recording paper (material) is used in a system in which a high voltage is applied to a recording needle to charge the electrostatic recording paper, and an image is formed by toner development and heat fixing. As an example of the above, a conductive layer in which fine particles of a metal oxide are dispersed in a binder is provided on the surface of a paper support, and an organic solvent-soluble resin layer containing calcium carbonate is formed on the conductive layer. A recording material has been disclosed (Japanese Patent Laid-Open No. 51-51980).
-25140 gazette, Japanese Patent Publication No. 58-27494 gazette,
JP-B-58-28574, JP-A-55-9524
JP-A-55-33134 and JP-A-56
38052). As an example of applying the conductive layer to a transparent plastic film instead of a paper support,
Japanese Patent Application Laid-Open No. 61-151542 discloses an antimony-doped stannic oxide (average particle size of 0.1 μm or less) and an adhesive (water-soluble resin) on a plastic film.
A conductive layer made of emulsion) and an electrostatic recording material having a dielectric layer formed on the conductive layer are described. Further, as a conductive layer (undercoat layer) of the electrophotographic light-sensitive material of the direct method, in JP-A-56-143443, stannic oxide (average particle diameter of 0.5 μm or less) is formed on a plastic film. A conductive layer made of a binder (water-soluble resin) is also disclosed.

Such a conductive layer containing fine particles of a metal oxide can cope with a change in humidity of the environment, and it can be considered to be applied to the electrophotographic film of the indirect method. However, in the above method, it is necessary to provide a conductive layer containing fine particles of a metal oxide and further provide an image receiving layer containing the matting agent thereon. That is, it is necessary to provide two layers on the transparent support as in the case of using the undercoat layer of the conductive resin,
It is extremely disadvantageous in manufacturing. Further, the electrostatic recording material described in the above publication is one in which a latent image is directly formed on the material surface and toner development is performed as described above, and it is necessary to have a surface resistance far lower than that of an electrophotographic film. Yes, it cannot be applied as is. The same applies to the conductive layer of the electrophotographic photosensitive material for the direct method. That is, in the indirect method electrophotographic film,
It is necessary to satisfactorily transfer the toner adhering to the latent image formed on the photoconductor of an electrophotographic copying machine to a film, and since it is generally possible to copy easily, a large number of copies are made, and the transportability of the film at that time It is desired to be excellent and to solve the above various problems.

[0007]

The present inventor has found that even if there is a change in the environment, especially a large change in humidity, the surface electric resistance does not fluctuate, and excellent transferability is exhibited during copying to obtain a high density image. Further, even under low humidity, triboelectrification is unlikely to occur during the processing step or handling, and therefore, the electrophotographic film having excellent transportability as well as excellent scratch resistance has a conductive layer and a layer formed on the transparent support. Since the image-receiving layer is obtained by forming only one image-receiving layer instead of a two-layer structure, the research has been earnestly conducted. As a new trial, the present inventor conducted studies to include fine particles of a metal oxide in the image receiving layer in order to obtain a stable surface electric resistance. However, when the metal oxide fine particles are added to the image receiving layer,
It is easy to control the surface electric resistance, but large unevenness occurs on the surface, the toner adhesion is not sufficient, and haze
However, there is a problem that it is large or is easily scratched during transportation. According to the study by the present inventors, the above problems can be solved by using fine particles of a conductive metal oxide having an average particle diameter of 0.1 μm or less and a matting agent of a resin having lubricity as a matting agent. Became clear,
The present invention has been reached.

Therefore, according to the present invention, even if there is a change in environment, especially a large change in humidity, there is almost no change in the surface electric resistance, excellent transferability is exhibited at the time of copying, and a high density image can be obtained. However, it is an object of the present invention to provide an electrophotographic film which is less likely to be triboelectrified during a processing step or handling, and is therefore excellent in transportability and also excellent in scratch resistance.

Another object of the present invention is to provide an electrophotographic film suitable for an OHP (overhead projector) film.

[0010]

The above object is to provide an image-receiving layer having a surface electric resistance at 25 ° C. and 65% RH in the range of 1 × 10 ⁹ to 1 × 10 ¹³ Ω on at least one surface of a transparent support. In the electrophotographic film provided with, the image receiving layer is composed of fine particles of a conductive metal oxide having an average particle diameter of 0.1 μm or less, a matting agent of a resin having lubricity, and a polymer. This can be achieved with a photographic film.

The preferred embodiments of the electrophotographic film of the present invention are as follows.

1) The electrophotographic film, wherein the matting agent material has a coefficient of static friction of 0.4 or less.

2) The electrophotographic film, wherein the material of the matting agent is polyolefin.

3) The matting agent has an average particle size of 0.1 to 1
The electrophotographic film in the range of 0 μm.

4) The electrophotographic film, wherein the metal oxide is Sb-doped tin dioxide (SnO ₂ ).

5) The electrophotographic film, wherein the polymer is a water-dispersible polymer.

6) The glass transition temperature of the polymer is 60
The electrophotographic film in the range of 120 ° C.

7) The electrophotographic film, wherein the polymer is a polyester resin.

Detailed Description of the Invention The electrophotographic film of the present invention has a structure in which an image receiving layer is formed on one surface or both surfaces of a transparent support. 1 and 2
The cross section of the basic constitution of the electrophotographic film of the present invention is schematically shown in FIG.

FIG. 1 shows an electrophotographic film having an image receiving layer 12 formed on one surface of a transparent support 11. The transparent support is a plastic film having transparency and excellent heat resistance, and the image-receiving layer is a layer in which metal oxide fine particles and a matting agent are dispersed in a binder, which is transferred by an electrophotographic copying machine. It has the function of holding the image.

FIG. 2 shows an electrophotographic film having image-receiving layers 22a and 22b formed on both surfaces of the transparent support 21.

The transparent supports 11 and 21 are transparent and
Any material can be used as long as it has the property of withstanding radiant heat when used as HP. The materials include polyesters such as polyethylene terephthalate;
Examples thereof include cellulose esters such as nitrocellulose, cellulose acetate and cellulose acetate butyrate, and polysulfone, polyphenylene oxide, polyimide, polycarbonate and polyamide. Of these, polyethylene terephthalate is preferred. The thickness of the film is not particularly limited, but is 50
Those having a particle size of up to 200 μm are preferable because they are easy to handle.

The image receiving layer is a layer in which fine particles of a conductive metal oxide having an average particle size of 0.1 μm or less and a flat matting agent are dispersed in a binder made of a polymer. The surface electrical resistance thereof needs to be in the range of 1 × 10 ⁹ to 1 × 10 ¹³ Ω (under the conditions of 25 ° C. and 65% RH).

The polymer used in the image receiving layer is not particularly limited. Examples thereof include polyester resin, polyether resin, acrylic resin, epoxy resin, urethane resin, amino resin and phenol resin. Of these, polyester resins are preferred. The polymer used in the present invention is preferably water-dispersible. The weight average molecular weight of the polymer is preferably in the range of 2,000 to 30,000. If it is less than 2,000, blocking tends to occur when the films are stacked and the strength of the film is lowered. On the other hand, when it exceeds 30,000, the toner offset phenomenon to the fixing roll is likely to occur. The polymer preferably has a glass transition temperature in the range of 60 to 120 ° C. When the temperature is lower than 60 ° C, the image receiving layer is melted or softened by the heat when the fixing roll is heated, and embossed marks of unevenness are left on the surface to impair the transparency. descend. In the present invention, it is preferable to use the aqueous dispersion of the water-dispersible polymer as the coating liquid for forming the image receiving layer as described above. A preferable polymer for forming an aqueous polymer dispersion is a water-dispersible polymer such as acrylic resin or polyester. The water-dispersible polymer of the present invention has a polar group (eg, quaternary ammonium salt group, sulfonate group, sulfonate group, carboxylic acid group, carboxylate group, phosphate group,
The phosphate group) is preferably contained in the molecule in the range of 0.1 to 10% by weight, and more preferably in the range of 1 to 5% by weight. Further, considering the dispersibility of the metal oxide fine particles, the polymer is preferably the above water-dispersible polyester, and particularly preferably a polyester having a sulfonate group in the molecule.

As the material of the conductive metal oxide particles, Z
nO, TiO, TiO ₂ , SnO ₂ , Al ₂ O ₃ , In ₂
O ₃ , SiO, SiO ₂ , MgO, BaO and MoO ₃
I can mention. These may be used alone or as a composite oxide of these. Further, the metal oxide preferably contains a different element,
For example, it is preferable that ZnO contains Al (In) or the like, TiO contains Nb, Ta or the like, and SnO ₂ contains Sb, Nb, a halogen element or the like (doping). Among these, SnO ₂ doped with Sb is
It is particularly preferable because it has little change in conductivity over time and high stability.

The metal oxide fine particles used in the present invention preferably have a small particle size in order to maintain the above-mentioned performance as an image receiving layer and to suppress light scattering as much as possible. A transparent electrophotographic film that can be used for an OHP (overhead projector), that is, a type of film that can be used by projecting an image,
In, the scattering efficiency is preferably 20% or less. For this purpose, the average particle diameter of the conductive metal oxide particles needs to be 0.1 μm or less, and is 0.05 μm.
The following are preferred. The mixing ratio of the metal oxide fine particles and the polymer is preferably in the range of 1: 3 to 3: 1 by weight.
The layer thickness of the image receiving layer has a surface electric resistance of 30 to 90.
It is generally in the range of 0.01 to 1.00 μm, preferably 0.05 to 0.5 μm, so that it is in the range of 1 × 10 ⁹ to 1 × 10 ¹³ Ω in the humidity range of% RH.

The matting agent of the above-mentioned resin having lubricity can improve the slipperiness of the image-receiving layer, and therefore exerts good effects on abrasion resistance and scratch resistance. The coefficient of static friction of the resin having lubricity, which is a matting agent material, is preferably 0.4 or less. Further, the softening point is relatively low (Vicat softening point is preferably less than 140 ° C., particularly 100 to 14).
0 ° C. is also preferable).

Examples of the resin having lubricity used for the matting agent include polyolefins such as polyethylene and fluororesins such as polyvinyl fluoride, polyvinylidene fluoride and polytetrafluoroethylene (Teflon). As specific materials, low molecular weight polyolefin wax (eg, polyethylene wax), high-density polyethylene wax, paraffin wax, or microcrystalline wax can be used. Examples of fluororesins include polytetrafluoroethylene (PTF
E) A dispersion may be mentioned. A low molecular weight polyolefin wax (generally having a molecular weight of 1000 to 5000) is preferred.

The average particle size of the resin matting agent is
The range of 0.1 to 10 μm is preferable, and the range of 1 to 5 μm is particularly preferable. The above-mentioned average particle diameter is preferably large, but if it is too large, the matting agent is detached from the image receiving layer to cause a powder drop phenomenon, the surface is easily damaged by abrasion, and further haze (haze degree) increases. The above range is preferable. Further, the content of the matting agent is preferably 0.1 to 10% by weight, and more preferably 0.5 to 5% by weight with respect to the polymer.
Weight percent is preferred.

The matting agent is preferably flat. A flat matting agent may be used in advance, or a matting agent having a relatively low softening temperature (preferably having the above-mentioned preferable softening point temperature) is used to coat the image-receiving layer and flatten it under heating during drying. Alternatively, it may be flattened while being pressed while being heated. However, it is preferable that the matting agent protrudes from the surface of the image receiving layer (layer corresponding to the polymer layer).

Other than the above, as the matting agent, inorganic fine particles (eg, SiO ₂ , Al ₂ O ₃ , talc or kaolin) and bead-shaped plastic powder (material example, cross-linked PM)
MA, polycarbonate, polyethylene terephthalate or polystyrene) may be used in combination.

The above image receiving layer has a density of 1 × 10 ⁹ to
It is required to have a surface electric resistance in the range of 1 × 10 ¹³ Ω (under the conditions of 25 and 65% RH). 1 x 10 ⁹ Ω
If it is less than 1, the toner amount when the toner is transferred to the image receiving layer of the electrophotographic film is not sufficient and the density of the obtained toner image is low, while if it exceeds 1 × 10 ¹³ Ω,
During handling of the electrophotographic film, static electricity is apt to be attached with dust, and misfeed and double feeding are likely to occur during copying. Furthermore, in order to suppress image defects (blurring) that are likely to occur under low humidity when the surface electric resistance is high,
It is particularly preferable to set the surface electric resistance in the range of 1 × 10 ^{9 to} 1.5 × 10 ¹⁰ Ω.

The image-receiving layer of the present invention preferably contains a surfactant in order to improve wettability during coating, emboss resistance and transferability. As a surfactant,
Although various compounds can be used, nonionic surfactants are preferable, and ethylene oxide nonionic surfactants are more preferable.

HLB (Hydrophile Lipophile Balance) of ethylene oxide nonionic surfactant is 1
The range of 1 to 14 is preferable. If the HLB is less than 11, the solubility in water will be low and the effect will be small.
When LB exceeds 14, it easily repels water and easily causes coating film defects. The image receiving layer using the ethylene oxide nonionic surfactant has an advantage that the adhesion to the toner image is improved as compared with the case of using other anionic or cationic surfactant. Specific examples of such ethylene oxide nonionic surfactants include nonipol 70, ibid 85, ibid 95, ibid 10
0 and 110, Octopole 60, 80 and 10
No. 0 and dodecapol 90 and 120 (above Sanyo Chemical Industry Co., Ltd.), and EMALEX / NP8.5 (above Nippon Emulsion Co., Ltd.) nonionic surfactants in which ethylene oxide is added to alkylphenol. be able to. The nonionic surfactant is preferably contained in the image receiving layer in an amount of 0.1 to 30% by weight based on the binder.

If desired, known materials such as colorants, ultraviolet absorbers, crosslinking agents, and antioxidants can be used in the image-receiving layer as long as the characteristics of the electrophotographic film of the present invention are not impaired.

The image receiving layer is formed, for example, by dispersing or dissolving the metal oxide fine particles, the matting agent, the binder, the surfactant, etc. in water, and coating the resulting coating solution on the transparent support, It can be carried out by heating and drying. The coating can be performed by a known coating method such as an air doctor coater, a blade coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, and a bar coater.

[0037]

【Example】

Example 1 A polyethylene terephthalate film having a thickness of 100 μm and thermally fixed by biaxial stretching was subjected to corona discharge treatment to prepare a support. Then, a coating liquid for forming an image receiving layer having the following composition was prepared. (The following values of parts by weight showing the blending amounts of all coating liquids are all solid contents or non-volatile contents)

[Image-Receiving Layer-Forming Coating Liquid] Water-dispersed polyester resin 1.44 parts by weight (WR-905; glass transition point: 70 ° C., polar group: sodium sulfonate, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 2.28 parts by weight of tin dioxide (SN-88; average particle size = 88 nm; manufactured by Ishihara Sangyo Co., Ltd.) 0.17 parts by weight of ethylene oxide nonionic surfactant (EMALEX / NP8.5; HLB = 12.6) , Japan Emulsion Co., Ltd. Low molecular weight polyethylene wax matting agent 0.07 parts by weight (Chemipearl W100; average particle size: 3 μm, softening point: 128 ° C., Mitsui Petrochemical Co., Ltd.) cross-linked PMMA matting agent 0 0.04 parts by weight (MR-2G-20-5; average particle size: 3 μm, manufactured by Soken Chemical Co., Ltd.) pure water 96.00 parts by weight

The coating solution for forming the image receiving layer was applied onto the conductive undercoat layer using a bar coater # 2.4 at a coating speed of 10
It was applied at 5 m / min and dried at 120 ° C. for 1 minute. Next, the other surface was similarly coated and dried to form an image receiving layer, and image receiving layers were formed on both surfaces of the film. The layer thickness was 0.15 μm. In this way, an electrophotographic film having image-receiving layers formed on both sides of the polyethylene terephthalate film was prepared.

Example 2 In Example 1, tin dioxide (SN-38; average particle size = 38 nm) was used instead of tin dioxide (SN-88; average particle size = 88 nm; manufactured by Ishihara Sangyo Co., Ltd.). An electrophotographic film was prepared in the same manner as in Example 1 except that Ishihara Sangyo Co., Ltd. was used.

[Comparative Example 1] In Example 1, a sodium sulfate-based surfactant was used in place of the tin dioxide (SN-88; average particle size = 88 nm; manufactured by Ishihara Sangyo Co., Ltd.), and an ethylene oxide-based surfactant was used. An electrophotographic film was prepared in the same manner as in Example 1 except that the coating solution for forming an image receiving layer having the following composition without using a nonionic surfactant was used.

[Image-Receiving Layer-Forming Coating Liquid] Water-dispersed polyester resin 1.79 parts by weight (WR-905; glass transition point: 70 ° C., polar group: sodium sulfonate, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) Sodium sulfate-based surfactant 0.11 part by weight (Emar O; manufactured by Kao Co., Ltd.) Low-molecular-weight polyethylene wax matting agent 0.07 part by weight (Chemipearl W100; average particle size: 3 μm, softening point: 128 ° C., Mitsui Petrochemical Co., Ltd.) Cross-linked PMMA matting agent 0.04 parts by weight (MR-2G-20-5; average particle size: 3 μm, Soken Chemical Co., Ltd.) pure water 99.99 parts by weight

[Comparative Example 2] Electrons were obtained in the same manner as in Comparative Example 1 except that an anionic surfactant (Demol N, manufactured by Kao Corporation) was used in place of the sodium sulfate-based surfactant in Comparative Example 1. A photographic film was made.

Comparative Example 3 An electrophotographic film was prepared in the same manner as in Example 1 except that the coating solution for forming an image receiving layer having the following composition was used in place of the coating solution for forming an image receiving layer. Created.

[Image-Receiving Layer-Forming Coating Liquid] Water-dispersed acrylic resin 1.44 parts by weight (ET-410; glass transition point: 44 ° C., manufactured by Nippon Pure Chemical Industries, Ltd.) tin dioxide 2.28 parts by weight (SN -88; average particle size = 88 nm; manufactured by Ishihara Sangyo Co., Ltd. Pure water 96.28 parts by weight

The characteristics of the electrophotographic film thus obtained were evaluated by the following methods.

1) Haze (%) Haze meter (HGP-2DP, Suga Test Instruments Co., Ltd.)
Manufactured).

2) Toner adhesiveness Electrophotographic copying machine (5017, manufactured by Fuji Xerox Co., Ltd.)
The resulting copy film was subjected to a cellotape peeling test on the entire image portion (black solid portion), and the optical density of the toner image before and after the cellotape peeling was measured with an optical densitometer (X-
Rite310TR, manufactured by X-Rite),
The toner adhesion was evaluated by the following formula.

3) Embossing resistance Electrophotographic copying machine (5026, manufactured by Fuji Xerox Co., Ltd.)
The image was copied with, and the presence or absence of unevenness of the film (when the unevenness becomes large causes a decrease in smoothness) was visually observed, and the emboss resistance was evaluated as follows. ○: The copy film had no unevenness. X: The copy film had unevenness and unevenness, resulting in poor smoothness.

4) Toner transferability Electrophotographic copying machine (5026, manufactured by Fuji Xerox Co., Ltd.)
The image was copied by using an optical densitometer (X-Rite 310) to measure the optical density of the obtained 10 copy films.
TR, manufactured by X-Rite), and the transferability of the toner image was evaluated by the average value. The above test is 28
C. and 85% RH atmosphere.

5) Film transportability Copies were made by an electrophotographic copying machine (Vivache 120; manufactured by Fuji Xerox Co., Ltd.), the number of double feeds per 100 copies was measured, and the double feed rate (%) obtained from the measured value was measured. The film transportability was evaluated by.

6) Surface electric resistance (Ω) Measured according to ASTM D257-78. Temperature and relative humidity at the time of measurement are 25 ℃, 65% RH and 20 ℃, 3
It was measured at 0% RH.

7) Scratch resistance Electrophotographic copying machine (5026, manufactured by Fuji Xerox Co., Ltd.)
The image was copied with and the scratches on the surface were observed and evaluated as follows. ◯: The scratches on the copy film were hardly noticeable. X: Many scratches were found on the copy film, which was noticeable.

The above measurement results are shown in Table 1 below.

[0056]

[Table 1] Table 1 ──────────────────────────────────── Evaluation items Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 ──────────────────────────────────── Hayes 3.3 2 0.0 2.5 3.3 8.2 Toner adhesion (%) 92 92 35 40 28 Embossing resistance ○ ○ ○ ○ × Toner transferability 1.20 1.22 0.21 0.15 0.90 Film transport Characteristics (%) 0 0 5 6 22 Surface electric resistance (Ω ) 25 ℃, 65% RH 1.1 × 10 ¹⁰ 1.0 × 10 ¹⁰ 2.3 × 10 ¹⁰ 2.2 × 10 ¹⁰ 1.3 × 10 ¹⁰ 20 ° C, 30% RH 1.1 × 10 ¹⁰ 1.1 × 10 ¹⁰ 4.0 × 10 ¹⁴ 3.9 × 10 ¹⁴ 1.4 × 10 ¹⁰ Scratch resistance ○ ○ ○ ○ × ─────────────────────────── ──────────

[0057]

EFFECT OF THE INVENTION The electrophotographic film of the present invention is an image receiving layer comprising fine particles of a conductive metal oxide (particle diameter of 0.1 μm or less), a matting agent of a resin having lubricity and a polymer on a transparent support. Is formed. That is, in the present invention, in order to obtain stable surface electric resistance, a conductive layer in which fine particles of metal oxide are dispersed in a polymer is used, and in that case, transportability, toner fixability, haze and scratch resistance, which are problems, are used. In order to obtain the above, the particle diameter of the metal oxide fine particles is set to 0.1 μm or less, and a matting agent having lubricity (excellent in transportability) is also used. By such a combination, it is possible to include fine particles of metal oxide in the image-receiving layer, which has not been heretofore considered, and to stably provide a predetermined amount even at high humidity, which is an advantage of using the fine particles of metal oxide. The above-mentioned drawbacks are eliminated while ensuring the surface electric resistance of the above. As a result, with a single image receiving layer,
It has become possible to obtain an electrophotographic film having properties (stable surface electrical resistance and other excellent properties) equivalent to a two-layer structure of a conductive layer and an image receiving layer. Therefore, the electrophotographic film of the present invention shows little change in surface electric resistance even when there is a change in the environment, especially a large change in humidity, exhibits excellent transferability at the time of copying to obtain a high-density image, and also has a low humidity. It can be said to be an electrophotographic film which is less likely to be triboelectrically charged even under the processing step and handling, and therefore is excellent in transportability and is also excellent in scratch resistance. In particular, when a water-dispersible polymer is used as a binder for the image-receiving layer, both layers can be formed without using an organic solvent and the desired effect can be obtained. It also has the advantage that problems such as environmental pollution and air pollution will not occur.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of the basic constitution of an electrophotographic film of the present invention.

FIG. 2 is a cross-sectional view showing another example of the basic constitution of the electrophotographic film of the present invention.

[Explanation of symbols]

 11, 21 Transparent support 12, 22a, 22b Image receiving layer

Front page continuation (72) Inventor Katsumi Harada 2274 Hongo, Ebina, Ebina, Kanagawa Prefecture Fuji Xerox Co., Ltd.Ebina Business Office (72) Inventor, Kazuo Asaka 2274, Hongo, Ebina City, Kanagawa Fuji Xerox Co., Ltd.Ebina Business Office

Claims (1)

[Claims] 1. A transparent support on at least one surface thereof,
Surface electrical resistance at 25 ° C, 65% RH is 1 × 10 ⁹
In the electrophotographic film provided with an image receiving layer in the range of 1 × 10 ¹³ Ω, the image receiving layer has an average particle size of 0.1.
An electrophotographic film comprising a fine particle of a conductive metal oxide having a size of not more than μm, a matting agent of a resin having lubricity, and a polymer.