JPS6130268B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to electrophotographic film. More specifically, the present invention aims to provide an electrofax type electrophotographic film which has excellent transparency and adhesion to a photoconductive layer, and which is particularly suitable for use as a second original. Conventionally, in electrofax type electrophotography, electrophotographic paper made of zinc oxide paper or organic photoconductive material was used as the second original image, but since both are paper-based, mechanical It has low strength and poor dimensional stability. Therefore, particularly in the field of industrial drawing, there has been a demand for an electrophotographic film for second original drawings that uses a transparent film as a substrate that has excellent mechanical strength, heat resistance, water resistance, dimensional stability, and the like. As an electrophotographic film, one has been proposed in which a metal vapor deposited layer is provided as a conductive layer on the film surface, and a photoconductive layer is provided thereon. However, when the photoconductive layer is made of an inorganic photoconductive material such as zinc oxide, selenium, cadmium sulfide, etc., it is not possible to impart sufficient translucency to the film for use as a second original, and the photoconductive layer is The adhesion of the layer to the base film is also insufficient. On the other hand, when an organic photoconductive material such as polyvinylcarbazole is used, it has its own translucency and homogeneity, and has a certain degree of film-forming ability, but it has the drawbacks of low strength and brittleness. Therefore, methods have been proposed for improving the physical properties of organic photoconductive layers by blending various resins. Examples of such methods include adding a butadiene-acrylonitrile copolymer to polyvinylcarbazole or its derivatives (see Japanese Patent Publication No. 46-43955), and adding polycarbonate or polyvinyl chloride to polyvinylcarbazole or its derivatives (see Japanese Patent Publication No. 46-43955). JP-A-50-53048) or a method of adding a thermoplastic aromatic polyester (see JP-A-50-57440). Additionally, a method is known in which a coating film of polyvinyl acetate added to brominated polyvinyl carbazole is formed on a polyester film on which cuprous iodide has been vapor-deposited (see JP-A-50-57231). ). However, in all of these, when a photoconductive layer with sufficient photosensitivity is provided, the adhesion of the photoconductive layer to the base film is insufficient, the folding strength is insufficient, and it is easily damaged. If an attempt is made to sufficiently improve mechanical properties such as strength and bending strength, there is a drawback that photosensitivity decreases. As a result of intensive research into an electrophotographic film that does not have these drawbacks and does not require the complicated vapor deposition process, the present inventor found that the acrylic surfactant containing a quaternary ammonium salt was added to the surface of the polyester film. A conductive layer is provided by applying a coating liquid containing a specific proportion of magnesium or calcium chloride and synthetic fine particle silica.
Furthermore, if a photoconductive layer is provided by applying a paint containing polyvinyl carbazole mixed with "a resin mixture containing a vinyl chloride/vinyl acetate copolymer, a methylolated amino resin, and an alkyd resin in a specific ratio", , the photoconductive layer has excellent adhesion to the base film, there is no need to provide a conductive layer by vapor deposition, and the conductivity of the conductive layer is not affected by humidity and is sufficient for electrophotographic applications even when dry. The present inventors have discovered that an electrophotographic film can be obtained which is particularly preferably used for second original images because it maintains good electrical conductivity and has excellent translucency, and has thus arrived at the present invention. That is, the present invention provides magnesium chloride and/or calcium chloride 1 to 100 parts by weight of the acrylic surfactant containing (A) quaternary ammonium salt.
The surface of a polyester film coated with a coating solution containing 15 parts by weight and 1 to 2 parts by weight of fine particle silica is coated with 40 to 60 parts of vinyl chloride/vinyl acetate copolymer per 100 parts by weight of (B) poly-N-vinylcarbazole. This electrophotographic film is coated with a paint containing 10 to 20 parts by weight of a resin mixture consisting of 20 to 40 parts by weight of a methylolated amino resin and 10 to 30 parts by weight of an alkyd resin. The polyester film used in the present invention is a film of aromatic linear polyester (typical examples thereof include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc.). The film may be unoriented, but an oriented film is preferred, and a biaxially oriented film is particularly preferred. The film may be unsurface-treated or surface-treated (for example, surface chemical treatment, brayer treatment, corona discharge treatment, matting treatment, etc.). The “acrylic surfactant containing a quaternary ammonium salt” used in the present invention has the general formula [However, R is hydrogen or an alkyl group having 4 or less carbon atoms. X is -OR ¹ , -NH ₂ ,

【formula】

[Formula] −NH−Y ² −OH, or −NHR. ^R1 , ^R2 , ^R3 ,
R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , and R ⁹ are a hydrocarbon group having 18 or fewer carbon atoms, a hydroxyalkyl group, or a halogenated alkyl group, and particularly preferably an alkyl group, an alkenyl group, or an aralkyl group. , these may be the same or different. Y ¹ and Y ² are divalent hydrocarbon groups having 8 or less carbon atoms, particularly preferably an alkylene group or a xylylene group, and they may be the same or different. Z is anion. ] A polymer consisting of two or more types of repeating structural units represented by, among the number of repeating units,

[expression] or

[Formula] (However, when both are used together, the total of both) is 20
~80%, and

It is a copolymer in which [Formula] accounts for 10 to 80%. The copolymer further comprises, among the number of repeating structural units,

【formula】

[Formula] and

[Formula] It is preferable that the composition contains 10% or less of a component selected from the group consisting of (when two or more are used, the total). A small amount of repeating structural units not represented by Formula 1 may be introduced into the copolymer within a range that does not substantially adversely affect the performance as a conductive agent. Copolymers that meet these requirements are known, for example, under the trade name Elecondo PQ-50B or Elecondo B-146 (both products of Shinken Kagaku KK). When forming the coating film (conductive layer) of the acrylic surfactant, it can be modified with a polyisocyanate compound (having two or more isocyanate groups in the molecule). This modification can further improve the water resistance of the coating film and the adhesion to the base film. The blending ratio of the polyisocyanate compound is 100% of the above acrylic surfactant.
The amount per part by weight is preferably 30 parts by weight or less. In the present invention, a coating liquid containing the acrylic surfactant, magnesium chloride and/or calcium chloride, and particulate silica is applied to the film surface. The blending ratio of magnesium chloride and/or calcium chloride is 1 to 15 parts by weight per 100 parts by weight of the acrylic surfactant (when both are used together, the total of both is 1 to 15 parts by weight). If the amount of magnesium chloride and/or calcium chloride is less than 1 part by weight, the conductivity is easily affected by the humidity of the atmosphere, which is undesirable, and if it is more than 15 parts by weight, the coating film may cause blocking when the humidity of the atmosphere is high. This is not preferable because it makes it easier. (It goes without saying that when using salts containing water of crystallization as these salts, the above blending ratio is for the portion excluding crystallizing water.) The blending ratio of fine particle silica is the same as that of the acrylic surfactant. The amount should be 1 to 2 parts by weight per 100 parts by weight. By blending fine particle silica in such a proportion, the conductivity in a low humidity atmosphere is significantly improved, and it becomes possible to use it as a conductive layer of an electrophotographic film even in a low humidity atmosphere. If the average particle size of the fine silica particles used here is too large, the surface of the conductive layer will feel rough and the thickness of the photoconductive layer provided thereon will increase, so it is preferable to have an average particle size of 10 μm or less. Fine particles of silica having an average particle diameter of about 7 mμ can be obtained, but in the present invention, not only such particles but also finer particles can be used. Note that the average particle size referred to here is a value measured by the sub-seep sizer method. To make a coating liquid in which "the acrylic surfactant" is blended with "magnesium chloride and/or calcium chloride" and "fine particle silica", "the acrylic surfactant" and "magnesium chloride and/or calcium chloride" are combined. What is necessary is to dissolve both in a solvent that can dissolve both of them, and further disperse the "fine particle silica". Preferably used solvents include water, alcohols (for example, methyl alcohol, ethyl alcohol, isopropyl alcohol, etc.), glycols (for example, ethylene glycol, propylene glycol, etc.), cellosolves (for example, methyl cellosolve, etc.), and cyclic ethers (for example, tetrahydrofuran, etc.). dioxane, etc.), ketones (e.g. acetone, methyl ethyl ketone,
methyl isobutyl ketone, etc.). It goes without saying that a mixture of two or more of these may be used as a solvent. The concentration of the coating liquid should be determined in consideration of the amount of the liquid applied to the film. The total of "the acrylic surfactant", "magnesium chloride and/or calcium chloride" and "fine particle silica" is
It is preferable to determine the concentration and coating amount of the coating solution so that the amount is 2 to 5 g per 1 m ² of the coated surface of the film.
When it is applied to the film surface and then dried (the solvent is removed), a film provided with a conductive layer is obtained. Application and drying may be carried out by conventional methods. Further, the coating may be applied to only one side or both sides of the film. In the present invention, poly-N-
Per 100 parts by weight of vinyl carbazole, 40-60% by weight of vinyl chloride/vinyl acetate copolymer, 20-40% by weight of methylolated amino resin, and alkyd resin.
A photoconductive layer is provided by applying a paint containing 10 to 20 parts by weight of a resin mixture consisting of 10 to 30% by weight. The vinyl chloride/vinyl acetate copolymer used in the present invention is a partially saponified vinyl chloride/vinyl acetate copolymer containing an OH group in the molecular chain and has a polymerization degree of about 400 to 600. The vinyl chloride/vinyl acetate polymer is produced by partially saponifying a copolymer consisting of 91 to 95 mol% of vinyl chloride component and 9 to 5 mol% of vinyl acetate component with an alkali, and the vinyl alcohol component accounts for 7 to 10% of the total. It is better to use denaturation to account for mol% of Eslec A.
(Product name; manufactured by Sekisui Chemical KK) and VAGH (Product name;
(Manufactured by UCC) etc. are exemplified. Methylolated amino resins include methylolated urea resins, methylolated melamine resins, and methylolated benzoguanamine resins, all of which can be used in the present invention, but methylolated melamine resins are particularly preferred. Furthermore, methylolated amine resins in which the terminal group is converted into butyl ether or methoxylated are preferable because the compatibility with other resins is improved. Specifically, Melan 20, Melan
22, Meran 23, Meran 26, Meran 27, Meran 28
(Product names; all manufactured by Hitachi Chemical KK): Nikaratsuk MW-30, Nikaratsuk MW-22, Nikaratsukku
MW-11 (Product name: Sanwa Chemical KK)
Examples include: The alkyd resin used in the present invention is a non-drying oil-type alkyd resin, which is a polyester resin with an acid value of 7 or less obtained by polycondensing an aromatic dicarboxylic acid such as phthalic anhydride or isophthalic acid with a polyhydric alcohol and a saturated fatty acid. . Examples of polyhydric alcohols include glycerin, pentaerythritol, trimethylolpropane, trimethylolethane, 1, 2, 6-
Trihydric or higher alcohols such as hexanetriol are used. As saturated fatty acids, coconut oil fatty acids, striped oil fatty acids, etc. are usually used, but caproic acid, caprylic acid, lauric acid, myristic acid,
One or a mixture of two or more free saturated fatty acids such as palmitic acid and stearic acid may also be used.
Known methods may also be used to polycondense aromatic dicarboxylic acids, polyhydric alcohols, saturated fatty acids, and the like. Commercial products of such non-drying oil-type alkyd resins include Phthalkyd M-132-60, Phthalkyd 133-60, Phthalkyd 133-60T (trade names; all manufactured by Hitachi Chemical KK): Betsukosol 3223,
Examples include Betsukosol 3233 (trade name; both manufactured by Nippon Reichhold KK). Among these resins, methylolated amino resins form a coating film that adheres well to the surface of a polyester film when baked, but the coating film is hard and tends to cause cracks such as crazes due to bending. This drawback is eliminated by blending the partially saponified vinyl chloride/vinyl acetate copolymer and the alkyd resin in the above ratio, and the former mainly imparts toughness and scratch resistance to the coating film, The latter imparts flexibility to the coating. Since the former is partially saponified, the OH group reacts with the methylolated amino resin during baking, making it insolubilized. Therefore, the solvent resistance of the coating film is also excellent. In the present invention, the average particle size of the photoconductive layer is 10 mμ to 10 μm.
The writability can be improved by adding inorganic fine powder (matting agent). In order to provide excellent writability, it is preferable to mix 5 to 20 parts by weight of the inorganic fine powder per 100 parts by weight of poly-N-vinylcarbazole. Preferably used inorganic fine powders include nepheline feldspar fine powders containing silicon oxide ( _SiO2 ) and aluminum oxide ( _Al2O3 ) as main components and having a Mohs hardness of 5 to 6 and an average particle size of 4 to _5μ . 40% by weight, amorphous synthetic silica fine powder with an average particle size of 15 to 40 mμ20
~40% by weight of "synthetic fine powder silica with an average particle size of 2 to 7μ", "fine powder alumina with an average particle size of 0.1 to 5μ", "silicon oxide (SiO ₃ ) and aluminum oxide (Al ₂ O ₃ )" ``Oxylate acid salt with an average particle size of 2 to 7μ mainly composed of magnesium oxide (MgO)'' or ``Oxylate acid salt with an average particle size of 0.1 to 5μ mainly composed of magnesium oxide (MgO) and calcium oxide (CaO)'' The average particle size per 100 parts by weight of a mixture containing 20 to 40% by weight of
An example is one to which 5 to 20 parts by weight of a whitening agent containing titanium oxide (TiO ₂ ) of 30 mμ as a main component is added. In the present invention, a sensitizer can be added to increase the sensitivity of poly-N-vinylcarbazole. The sensitizers include, as dye sensitizers, triphenylmethane basic dyes and their carbonium salts such as crystal violet and methylene violet; xanthene dyes such as eosin, erythrosin, and fluorescein; thiazines such as methylene blue and Nile blue; Other dyes; other acridine dyes; azine dyes; triazine dyes; cyanine dyes; styryl dyes; azo dyes, and chemical sensitizers such as metal halogens; carboxylic acids; Polycyanoid compounds such as ethylene and tetracyanoquinodimethane; quinone, chloranil, bromanil, anthraquinone,
Quinones such as tetrabromnaphthodiquinone; 2.
4,7-trinitrofluorenone, 2,4,5.
Nitrofluorenone compounds such as 7-tetranitrofluorenone; 9-dicyanomethylene-2.4.
Examples include nitrofluorenone derivatives such as 7-trinitrofluorene. Some of these have a sensitizing effect, but some of them worsen the hue when added in a large proportion, so in order to sensitize to a sufficiently high sensitivity without worsening the hue, 2.
4,7-trinitrofluorenone, 2,4,5.
Preferably, electron-accepting nitro compounds such as 7-tetranitrofluorenone are used. The sensitizer is 0.5 per 100 parts by weight of poly-N-vinylcarbazole.
It is preferable to mix it in a proportion of ~1.5 parts by weight. If necessary, a small amount of violet or blue dye may be added to the photovoltaic layer to improve the hue. To provide a photoconductive layer, a solution containing the above-mentioned acrylic surfactant, etc., is applied to the polyester film, and then a layer of poly-N-vinylcarbazole vinyl chloride, etc. A paint containing a vinyl acetate copolymer, methylolated amino resin, alkyd resin, etc. (and other additives, if any) may be applied and dried. The solvent for the paint can be anything that can dissolve these polymers, but tetrahydrofuran, which is a poor solvent or non-solvent for the acrylic surfactant used in the conductive layer that is the undercoat, or aromatic hydrocarbons. It is preferable to use or a derivative thereof (for example, benzene, toluene, monochlorobenzene, etc.). Alternatively, when the conductive layer is modified (crosslinked) with a polyisocyanate compound, a good solvent for an acrylic surfactant such as ketones, esters, etc. is also preferably used. In the present invention, when providing the photoconductive layer, there is no problem even if the surface layer of the undercoated conductive layer swells or melts, so that there is no clear boundary between it and the photoconductive layer. To apply a paint containing poly-N-vinylcarbazole to the film surface provided with a conductive layer,
Flow coating, roll coating, doctor knife coating,
It is convenient to employ methods such as air knife coating and spray coating because they can be operated continuously at high speed and provide a homogeneous coating film. The amount of coating is based on the total resin (poly-
(containing N-vinylcarbazole) is on the film side 1.
Preferably, the amount is between 5 and 10 g per m ² . The coating film is preferably dried and cured at 80 to 150°C. The electrophotographic film of the present invention can always maintain high sensitivity regardless of the humidity level, has excellent adhesion of the coating film to the base film, and has high resistance to rubbing tests. Furthermore, since the film has high translucency, dimensional stability, mechanical strength, etc., it has excellent performance especially for second originals. Also, since matting agents can be easily added and corrected, they can be used for enlarged copying from microfilm, close transmission copying, or reflected light copying up to A-1 or A-0, especially in the drafting field. Suitable for a wide range of uses. Next, the characteristics of the electrophotographic film of the present invention will be explained with reference to the drawings. FIG. 1 shows a conductive layer formed by applying a liquid containing the acrylic surfactant used in the present invention at a solid content of 3 ^g per m ² of the film surface. A coating containing 80 parts by weight of poly-N-vinylcarbazole, 10 parts by weight of an adhesive, 10 parts by weight of a matting agent and 0.8 parts by weight of a sensitizer was applied on top of the coating, with a total solid content per 1 m ² of the film. This is a diagram showing an example of the potential characteristics at 20°C of an electrophotographic film coated with a photoconductive layer at a rate of 10 g. Curve A is when the relative humidity is 30%, and curve B is when the relative humidity is 60%. . This result shows that this electrophotographic film has good photosensitivity even at low humidity. Fig. 2 shows a conductive layer coated with ``magnesium chloride or calcium chloride'' made only of the above-mentioned acrylic surfactant and containing no particulate silica at a solid content of 3 g per 1 m ² of film. This is a diagram showing the potential characteristics at 20° C. of an electrophotographic film provided with a photoconductive layer similar to that in FIG. 1, where curve C is for a relative humidity of 30% and curve D is for a relative humidity of 60%. From this result, this electrophotographic film tends to have poor photosensitivity at low humidity and large darkening at high humidity. Hereinafter, the present invention will be explained in detail with reference to Examples. Example 1 80 g of poly-N-vinylcarbazole was mixed with a mixed solvent of tetrahydrofuran and toluene (weight ratio: 2:
8) Dissolve in 720g to make a concentration of 10% by weight. As an adhesive liquid, 250 g of partially saponified vinyl chloride/vinyl acetate copolymer (product name "VAGH"; manufactured by UCC Co., Ltd., resin concentration 20% by weight) and butyl etherified methyl melamine resin (product name "Melan-20"; Hitachi Chemical
Made by KK. 60g of non-drying oil-type alkyd resin (product name "Fthalkyd M132") (resin concentration 50% by weight)
-60"; manufactured by Hitachi Chemical KK. 180 g of tetrahydrofuran and 477 g of toluene were added to the resin mixed with 33 g of resin concentration 60% by weight, so that the weight ratio of tetrahydrofuran and other solvent was 2:8. 90g of the above poly-N-vinylcarbazole solution prepared as an adhesive solution with a resin concentration of 10% by weight
10g of adhesive liquid was mixed with 10g of adhesive liquid, and nepheline syenite fine powder (trade name “Minex7”; Canada) was added as a matting agent.
Indusmin) 0.33g, synthetic fine powder silica (trade name "Thyroid 308"; Fuji de Vison KK)
Made. ) and 0.33 g of amorphous synthetic silica fine powder (trade name "R-972" manufactured by Nippon Aerosil KK) were added and dispersed in a ball mill for 24 hours, resulting in a coating material A. Next, 20 g of the adhesive solution (resin concentration 10% by weight) was mixed with 80 g of the poly-N-vinylcarbazole solution (concentration 10% by weight), and the same amount of matte as in the case of solution A was further added. The paint obtained by adding the agent and dispersing it in a ball mill for 24 hours is designated as B.
Similarly, the poly-N-vinylcarbazole solution
70g of the above adhesive solution and the same amount of matting agent as in the case of Solution A were added to paint C.The ratio of 40g of the above adhesive solution to 60g of the above poly-N-vinylcarbazole solution was mixed. A paint containing exactly the same amount of matting agent as in case A was designated as D. An acrylic surfactant containing a quaternary ammonium salt (trade name "Elecondo B-") is used as a coating solution for forming a conductive layer on a polyester film.
146”, manufactured by Soken Kagaku KK. Solid content concentration 40% by weight)
100g, polyisocyanate compound (trade name "Desmodyur N-75", manufactured by Bayer AG, solid content concentration 75% by weight) 12g, magnesium chloride hexahydrate (MgCl ₂ 6H ₂ O) 4.90g, average particle size 7μ Add 0.98 g of synthetic fine powder silica (trade name "Syroid 308", manufactured by Fuji Davison KK) to 145 g of a mixed solvent of methyl ethyl ketone, toluene, and ethyl cellosolve (weight ratio 1:1:1), and dissolve or dissolve by stirring and mixing. A coating solution was prepared by dispersing it. The coating solution was applied to a biaxially oriented polyester film with a thickness of 50 μm to a solid content of 3 g/m ² , and the coating solution was applied to a biaxially oriented polyester film with a thickness of 50 μm as a base material a. PAS-88"; manufactured by Toyobo KK. Solid content concentration 35% by weight) 22.9 g, polyvinyl alcohol (product name "Poval A"; manufactured by Shin-Etsu Chemical KK) 1.0 g, acrylic acid ester resin emulsion (product name "Cybinol EC6701"); Made by Saiden Kagaku KK.A mixture of 2.5g (solid content concentration 40% by weight) and 140.3g of water was applied to a corona-treated biaxially oriented polyester film with a film thickness of 50μ at a solid content coverage of 1g/ ^m2 . The obtained material was designated as base material B, and the aluminum-deposited polyester film was designated as base material C. Next, apply the paint A, B, C or D to the base material a,
The amount of solid content deposited on the conductive layer b or c, respectively.
Apply with a bar coater at a rate of 10g/m ² and heat at 80℃.
and dried for 3 minutes. After that, the adhesiveness was evaluated after being left at room temperature and humidity for 1 hour. The evaluation was carried out by making 100 scratches on the film surface at intervals of 10 mm x 10 mm, deeper than the thickness of the two layers, and after adhering Sellotape to the surface, peeling off the Sellotape, and determining whether the scratches remained without being peeled off by the Sellotape. Find the number of gobans N of the coating film, and calculate N/100.
Adhesion was judged to be good or bad. Table 1 shows the results. The compatibility between the poly-N-vinylcarbazole component in the paint and the adhesive component is also listed in Table 1.

[Table] The blank is a case where a biaxially oriented polyester film without corona discharge treatment and without a conductive layer was used as the base material. From the above results, it can be seen that the adhesion of the coating film was good only when the base material a was used, and the adhesion of the base material b and the base material c was not as good as that of the blank. The one using base material a has the lowest adhesive content and poly-N
- It can be seen that excellent adhesion is obtained even in the case of paint A with a high vinyl carbazole content, and that an electrophotographic film with high sensitivity and excellent coating film adhesion can be obtained. Example 2 Poly-N- with a concentration of 10% by weight prepared in Example 1
1 g of the adhesive solution with a concentration of 10% by weight prepared in Example 1 was added to 8 g of the vinyl carbazole solution and mixed well, and 0.03 g of the same nephelinite feldspar fine powder used in Example 1 was added as a matting agent. 0.03 g of the same synthetic fine powder silica used in Example 1, 0.03 g of the same amorphous synthetic silica fine powder used in Example 1, and titanium dioxide (trade name "P-
A solution (undiluted solution) was prepared in which 0.01 g of 25" (manufactured by Nippon Aerosil KK) was dispersed. 0.008 g of 2,4,7-trinitrofluorenone and 0.002 g of a bluing agent were dissolved in the stock solution. In addition, a solution obtained by dissolving 0.008 g of 9-dicyanomethylene-2,4,7-trinitrofluorene and 0.0015 g of a bluing agent in the stock solution is designated as paint F. Base material a used in Example 1 On the conductive layer of the same polyester film, paint E or F was applied with a bar coater to a solid content of 10 g/m ² and dried at 80°C for 3 minutes to obtain an electrophotographic film. .These electrophotographic films were stored at room temperature and humidity for 10 minutes.
After leaving it for a minute, use a static honest meter made by Anato Shokai to measure -7KV in an environment at 17℃ and RH45%.
After corona charging for 20 seconds (the surface potential at this time is Vm), and darkening for 7 seconds (the surface potential at this time is _V0 ), the sample was irradiated with a 50 lux tungsten lamp. half-reduced exposure (E
1/2). Table 2 shows the results. Note that t1/2 in Table 2 means that the surface potential is 1/2 after light irradiation.
It is the time until V ₀ , and V ₁₀ is the time from light irradiation to 10
This is the surface potential after seconds.

[Table] Reference Example 1 100 g of the same "acrylic surfactant containing a quaternary ammonium salt" (solid content concentration 40% by weight) used in Example 1, and the same polyisocyanate compound ( A conductive layer was formed by adding 12 g of solid content (75% by weight) to 145 g of methyl ethyl ketone and mixing well, and applying the coating solution at a solid content of 3 g/m ² onto the surface of a biaxially oriented polyester film with a film thickness of 50 μm. Ta. The film is used as a base material e
shall be. Coating material F prepared in Example 2 was applied onto the conductive layer of base material e in exactly the same manner as in Example 2 to obtain an electrophotographic film (Comparative Sample 1). The electrophotographic film and Experiment No. 2 of Example 2
The humidity dependence of the potential characteristics of the electrophotographic film (same as the comparative sample except that the conductive layer composition is different) is
Table 3 shows the results measured using the same method as used in Example 2.

[Table] It can be seen that when an inorganic salt is dissolved in the conductive agent, the sensitivity is high even at low humidity, but when no inorganic salt is added, the sensitivity decreases markedly at low humidity. Example 3 Liquid 1365 with the same composition as paint F prepared in Example 2
510 g of monochlorobenzene was added to G to prepare paint G having a solid content concentration of about 8% by weight. Paint G was coated on base material a prepared in Example 1 with a kiss roll coating at a solid content of 8 g/ ^m2 .
It was dried at ℃ for 3 minutes to obtain an electrophotographic film. The electrophotographic film was left in a bright place at room temperature and humidity for 10 days, and then transferred to an electronic copying machine (product name: Jumbo).
-500FX (manufactured by Canon KK) was used to make an enlarged copy from the microfilm, and a clear image faithful to the original was obtained, and toner adhesion was also good. Next, use this image as the second original image,
When diazo copying was carried out, a clear third generation diazohypie was obtained. Further, this electrophotographic film had good light transmittance, with a transmittance of 70% or more over the entire visible range from 360 nm, and a pencil writing property of up to H.

[Brief explanation of the drawing]

FIGS. 1 and 2 are diagrams showing examples of potential characteristics of an electrophotographic film.

Claims (1)

[Claims] 1 (A) A coating liquid containing 1 to 15 parts by weight of magnesium chloride and/or calcium chloride and 1 to 2 parts by weight of fine particle silica is applied per 100 parts by weight of an acrylic surfactant containing a quaternary ammonium salt. (B) poly-N on the polyester film surface
- 10 to 20 parts by weight of "resin mixture consisting of 40 to 60% by weight of vinyl chloride/vinyl acetate copolymer, 20 to 40% by weight of methylolated amino resin, and 10 to 30% by weight of alkyd resin" per 100 parts by weight of vinylcarbazole An electrophotographic film coated with a paint containing