JPS59220754A - Printing plate for electrostatic printing - Google Patents

Abstract

PURPOSE:To obtain a printing plate for printing a small lot of 100-1,000 sheets having sufficient sensitivity even to semiconductor laser beams by using a photoconductive layer composed of a phthalocyanine pigment, ZnO, and ZnS, and an electrically conductive toner to form a printing plate for electrostatic printing. CONSTITUTION:A photosensitive body 3 is composed of a conductive substrate 1 and a photoconductive layer 2 prepared by dispersing into a binder resin, ZnO, ZnS, and a phthalocyanine pigment, such as X-type (alpha-type, beta-type) metal-free phthalocyanine, epsilon-type (alpha-type, beta-type) copper phthalocyanine, or various other phthalocyanines. The photosensitive body 1 is exposed to semiconductor laser beams 4, the obtained latent image is developed with an electrically conductive toner, and fixed to form a printing plate for electrostatic printing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing plate for electrostatic printing suitable for obtaining printed matter in small lots of about 1,000 to 1,000 copies. The present invention relates to a printing plate for electrostatic printing manufactured using a photoreceptor dispersed in a resin and having sufficient sensitivity to semiconductor laser light to an unprecedented degree.

That is, one of the objects of the present invention is to write information inputted by an electric signal using a semiconductor laser beam to produce a printing plate for electrostatic printing.
．． It is an object of the present invention to provide a printing plate for electrostatic printing which can easily achieve high-quality reproduction of OOO copies.

Recently, with the streamlining of office work, Japanese word processors have become popular. With a conventional typewriter, each character is printed one by one for each type of minus character, but with a word processor, the typed characters are not printed immediately, but are recorded in an electrical storage device (memory) and , since it is only displayed on the cathode ray tube, corrections and additions can be made easily. There are also inkjet printing methods, thermal recording methods, wire tod printing methods, and electrophotographic printing methods that use lasers to print the letters of the Japanese word Brosenosaur. Among electrophotographic methods using lasers, those using semiconductor lasers are becoming popular.

Semiconductor lasers have a relatively small optical output of several mW to several tens of mW during continuous operation, but compared to other solid-state lasers and gas lasers, they are ultra-small, have high efficiency, low voltage, and low power consumption. This is because it has many advantages, such as high-speed direct modulation using current that exceeds IGH2, good compatibility with peripheral semiconductor circuits such as IC, high reliability unique to semiconductors, and cost reduction due to mass production. be.

・Currently, there are semiconductor lasers such as AIG and aA.
S laser (visible light and short wavelength laser) and InGaA,
Although sP lasers (long wavelength lasers) have been put into practical use, AlGaAs lasers are primarily used for information processing.
Visible light laser of 076-08μm or 0.83-0.88
Either a short wavelength laser of μm is used.

However, in laser printers that use semiconductor lasers, the output of the semiconductor laser is similar to that of other gas lasers (Ar, He, etc.).
-Ne, He-Cd, etc.), and the sensitivity of currently used photoreceptors is lower than that of semiconductor lasers, making it impossible to increase the copy speed.

The present invention aims to eliminate the above-mentioned drawbacks, and particularly relates to improvements in the photoreceptor used. That is, the present invention writes information directly onto a photoreceptor using a semiconductor laser beam, uses the photoreceptor as an electrostatic printing plate, performs high-speed electrostatic printing, and meets the need for large number of copies.

Here, currently, as conventional optical semiconductors sensitive to semiconductor laser light, Cd5-Cu, Se'
There are f e / Se, amorphous Si, phthalocyanine photoreceptors, etc., but they are not suitable for use or disposal as electrostatic printing plates. Therefore, as a photoreceptor suitable for use in the present invention, a phthalocyanine-receptor is preferred, but a phthalocyanine-receptor is preferred;
Anine pigment has a small average particle size of 0.05 μm and has poor charge retention, so in order to use it as a photoreceptor, it is necessary to increase the ratio of binder resin components. Since the layer surface is very smooth,
The fixing properties of the toner are extremely poor, and if an image is formed on this photoreceptor with conductive toner and fixed, the toner will peel off during the electrostatic printing process, making it unusable as an electrostatic printing plate. It was something that I had.

Therefore, the inventors of the present invention conducted extensive research in order to improve the fixation of toner on this photoreceptor, and as a result, they discovered that zinc oxide was dispersed in the photoconductive layer that constitutes the phthalo-7-anine pigment-resin photoreceptor. It was discovered that improvements could be made by making the surface matte.

However, since this printing plate for electrostatic printing uses only zinc oxide as a filler and is dispersed in the photoconductive layer, it has the drawback of poor charge retention properties and dark decay properties for positive charges. Therefore, the present inventors have discovered that phthalocyanine pigments-
Various fillers were added to a resin-based photoreceptor, and toner fixability, charge retention characteristics, and other properties were tested.

When we tested fillers such as titanium oxide, calcium carbonate, cadmium carbonate, magnesium oxide, zinc oxide, and zinc sulfide, most of the fillers had improved fixing properties compared to phthalocyanine pigment-resin photoreceptors. However, it was confirmed that the photosensitivity and charge retention were significantly decreased, and dark decay was increased. However, only those in which zinc oxide and zinc sulfide were selected as fillers had good charge retention and dark decay characteristics for positive charging, although there was a slight decrease in photosensitivity.

However, those with only zinc oxide as filler,
The charge retention and dark decay characteristics for positive charges are poor, and those using only zinc sulfide as a filler have good charge retention and dark decay properties for positive charges, but have the disadvantage of a large residual potential. there were.

In this photoreceptor, since the phthalo/anine pigment has the advantage of photosensitivity, the electrophotographic properties with respect to positive charging are better.

In addition, the average particle size of zinc oxide and zinc sulfide is 0.6 μm, which is an order of magnitude larger than that of phthalocyanine pigments, and because they have excellent charge retention properties, the binder resin component ratio can be lower than that of phthalocyanine pigments alone. The surface becomes matte. The increased matte surface area improves toner adhesion. Next, the inventors aimed to improve photosensitivity. When a highly sensitive phthalocyanine pigment that is sensitive to semiconductor laser light is used as a photoreceptor, and zinc oxide and zinc sulfide are added as fillers, the photoreceptor of a printing plate for electrostatic printing and I- We obtained the knowledge that the properties of all materials are further improved.

That is, as an example of a photoreceptor, on a conductive support,
Binds ε-type copper phthalocyanine and a mixture of phthalocyanine with an electron-withdrawing group or a mixture of phthalocyanine with an electron-withdrawing group and other phthalonanine with the acid-pasted phthalocyanine derivative fBl, zinc oxide and zinc sulfide It has a photoconductive layer dispersed in the agent.

The present invention relates to a printing plate for electrostatic printing, in which the photoreceptor is charged and exposed to light using a semiconductor laser source or the like to form a latent image, and the latent image is developed using conductive toner and fixed.

Hereinafter, the present invention will be described in detail with reference to the drawings. As shown in FIG. After the photoreceptor (3) obtained by applying (2) is charged by corona irradiation with a charging device, it is exposed to semiconductor laser light (4) modulated by an electric signal as shown in FIG. An image is formed, and as shown in FIG. 6, it is reversely developed with conductive toner (5), or as shown in FIG. 4, it is normally developed, and as shown in FIG. An electrostatic printing plate (8) consisting of (6) and an insulating portion (7) is produced.

In addition, the phthalocyanine pigments used in the present invention include XW metal-free phthalocyanine, ε-type copper phthalocyanine, α-type copper phthalocyanine, β-type copper phthalocyanine, α
These include type metal-free phthalocyanine, β-type metal-free phthalocyanine, vanadyl phthalocyanine, and phthalocyanine derivatives having electron-withdrawing groups such as nitro groups that are acid-pasted into fine particles developed by the present inventors.

Here, the phthalocyanine having an electron-withdrawing group includes an electron-withdrawing group such as a nitro group, a cyan group, a halogen atom, a sulfone group, a carboxyl group, a sulfamide group, a carboxamide group, etc. in the benzene nucleus in the molecule of metal-free or various metal phthalocyanines. is substituted with a natural group.

This phthalocyanine derivative is used during phthalocyanine synthesis.
Phthalonitrile, phthalic acid, phthalic anhydride, and phthalimide, which are separated from phthalocyanine, can be obtained by fanning or partially using phthalonitrile, phthalic acid, phthalic anhydride, and phthalimide substituted with the above substituents. It will be done. The method for producing the phthalocyanine derivative is not particularly limited. Further, the number of substituents in one molecule of the phthalocyanine derivative is 1 to 16.

The above-mentioned phthalocyanine having an electron-withdrawing group is subjected to an acid pasting treatment together with other phthalocyanine having no electron-withdrawing group to form a phthalocyanine derivative, if necessary. Here, the acid pasting treatment refers to phthalocyanine or phthalocyanine having the above electron-withdrawing group, sulfuric acid, orthosulfuric acid, pyrophosphoric acid, chlorosulfonic acid, hydrochloric acid, hydroiodic acid, hydrofluoric acid, hydrobromic acid, etc. This is a processing method in which a salt is formed with an inorganic acid, and the phthalocyanine derivative is poured into water as known in the organic pigment industry, and the precipitated phthalocyanine derivative is filtered, washed with water, and dried, and a product having an α-type crystal form is obtained.

The photoreceptor used in this application is made by uniformly dispersing the phthalocyanine pigment together with a binder resin, a solvent, etc. using a cross-dispersion machine such as a ball mill or an attriter, and then adding zinc oxide and zinc sulfide powder to the same cross-dispersion. The photoconductive layer is uniformly dispersed in a machine and coated onto a conductive support. Note that it is also effective to provide a barrier layer between the conductive support and the photoconductive layer.

In addition, as the filler, any zinc oxide that is commonly used for powdered electrophotography can be used, and as the zinc sulfide, a general reagent can be used.
It is cheap and non-toxic.

The mixing ratio of the phthalocyanine pigment and (zinc oxide + zinc sulfide) is phthalocyanine pigment / (zinc oxide - zinc sulfide) = 20 to 6 Dwt%, zinc sulfide / zinc oxide = 10 to 5
(] wt%).In other words, if the phthalocyanine pigment is less than 20wt%, the photosensitivity to semiconductor laser light is insufficient, while if it exceeds 60wt%, the fixability of the conductive toner deteriorates. It is from.

In addition, if the ratio of zinc sulfide to zinc oxide is less than 10 wt%, charge retention and dark decay characteristics will not be sufficient;
If it exceeds 50 wt%, the residual potential will increase and become inappropriate.

Of course, the above matters are greatly influenced by the amount of binder resin added. The binder resin ratio is phthalonoamine/binder resin 1] 1-20 from the viewpoint of film properties and charge retention properties.
Good results were obtained when the content was ~50 wt%.

Binder resin is melamine resin, butyral 1411
1&, epoxy resin, silicone resin, polyester resin,
Known materials having insulating properties such as polyester resins, acrylic resins, xylene resins, vinyl chloride-vinyl acetate copolymer resins, polycarbonate resins, and cellulose derivatives having a volume resistivity of about 10@-7 Ω or more are used. Examples of solvents include aromatic hydrocarbons such as benzene, toluene, xylene, and chlorobenzene, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, alcohols such as methanol, ethanol, and inopropanol, and esters such as ethyl acetate and methyl cellosolve. Carbon tetrachloride, chloroform, dichloromethane, halogenated hydrocarbons, tetrahydrofuran, ethers such as dioxane, and dimethylformamide, dimethyl sulfoxide, etc. are used.

Conductive supports include aluminum, brass, copper,
Metal plates such as stainless steel or metal sheets, Flastinoxy-1, on which aluminum, palladium 6, metal oxides, etc. are vacuum-deposited, plastic plates, paper, etc. with conductive treatment, and metal oxide plates. Can be used.

The coating method is to adjust the viscosity by adding a solvent if necessary, and use an air knife coater, plate coater, -tar, etc.
The film is formed using a coating method such as a rod coater, reverse roll coater, spray coater, hot coater, or squeeze coater.

After application, drying is carried out using a suitable drying device.

Furthermore, there are two types of conductive toner: liquid toner and powder toner.For liquid toner, conductive liquid toner is made by dispersing conductive toner in an electrically insulating carrier liquid with a boiling point of 100 to 20Q°C. It is something that The toner is composed of a conductive agent, a fixing agent, a charge control agent, and the like.

As a conductive liquid tonanocarrier liquid, the boiling point is 120
~20[1°C isoparaffinic solvents are often used.

For positively charging conductive liquid toner, conductive carbon black or the like can be used as a conductive agent, but a carbon blank treated with a nigrosine dye is also used to stabilize the charging polarity. Fixing agents include alkyd resins, cyclized rubber, natural resins soluble in aliphatic hydrocarbons, asphalt, acrylic resins, copolymers of higher alkyl esters of methacrylic acid and various types of nil monomers, and charge control agents. For this purpose, fatty acids and metal salts such as naphthenic acid, higher fatty acids, antioxidants, etc. are used. Examples of the conductive agent for the negatively charged conductive liquid toner include furnace carbon black and grafted carbon black containing vinylpyrrolidone.

Fixing agents include cyclized rubber, acrylic resins, and acrylic resins copolymerized with monomers having highly electronegative phenolic hydroxyl groups, sulfone groups, and ester sulfate groups.Charge control agents include furan and oil-soluble sulfonic acids. Salt etc. are used.

Powder conductive toners include copper, iron, aluminum, silver, zinc, black iron oxide, copper oxide, copper iodine, copper chloride, silver oxide, cobalt oxide, indium oxide, carbon black, etc. Powders and suitable resins that exhibit adhesive properties under the application of heat or pressure, such as styrene resins, epochino resins, vinyl chloride resins, vinyl butyral resins, acrylic resins, waxes, etc., can be used; - component conductive toners is generally well known. -Component Conductive toner includes conductive non-magnetic toner and conductive 8-character toner. As a developing method for conductive non-magnetic 1.S-
There is a touchdown development method proposed in Japanese Patent Publication No. 491 and Japanese Patent Publication No. 37-492, in which conductive developer particles are uniformly coated on the surface of a sleeve having a conductive surface. This is a method in which the image is developed by bringing it into contact with an electrostatic charge image. It is said that the toner preferably has a particle size of 20 μm or less and is made of powdered metal, graphite, carbon blank, and thermoplastic resin. Furthermore, as a developing method using conductive magnetic toner, there is a magneto-dry developing method proposed in Japanese Patent Application Laid-Open No. 49-4532. In this method, a conductive magnetic toner and an electrostatic charge image are brought into contact with each other and developed. The toner is composed of a thermoplastic resin, a magnetic material, and conductive fine particles, and has a particle size of 1 to 50 μm, preferably 5 to 30 μm, and a good conductivity of 1080 cm to 10 2 -Ω.

For example, when using a one-component conductive magnetic toner such as paraffin wax, ethylene-vinyl acetate copolymer, and black iron oxide (magnetite), generally 20 to 50 kg/
It can be passed between steel polishing rolls with a pressure of CwL and fixed under pressure.

Furthermore, for example, the inner wall is a colloidal material, the outer wall is a double wall made of a mixed system of hydrophobic resin and normal phase or dye, and the outer wall contains a magnetic liquid or semi-solid inside, and the outer wall has a volume characteristic of 10 Ω or less. Conductive magnetic microcapsule toners that have resistance can also be used.

Above, we have mainly discussed the use of semiconductor laser light as an exposure method for the photoreceptor, but the photoreceptor used in the present invention has a far greater photosensitivity to semiconductor laser light than conventional products. Although its greatest feature is that it is high, it also has excellent photosensitivity to visible light in the range of 400 to 70011 m, and can be sufficiently applied using conventional general exposure methods and light sources.

The present invention will be explained below by way of example. In the examples, nKJ indicates parts by weight.

(Preliminary Experiment) 40 parts of copper phthalocyanine and 05 parts of tetranitrocopper phthalocyanine were dissolved in 500 parts of 98% concentrated sulfuric acid with thorough stirring. The dissolved solution was poured into 5000 parts of water to precipitate a composition of copper phthalocyanine and tetranitrocopper phthalocyanine, which was then washed with water and dried at 12[]°C under reduced pressure. The composition [I] obtained in this manner was injected into an ε-type copper lid manufactured by Toyo Ink Manufacturing Co., Ltd.
O11018I 11 e Pr R) 100 parts to 100 parts were mixed and dispersed in 5000 parts of methanol to form a homogeneous mixed dispersion. After that, filter and under reduced pressure 1
Dry at 20°C to make mixture [11].

Next, 5 parts of the above mixture [11] and acrylic polyol (
25 parts of Takelac UA-702 (manufactured by Narita Pharmaceutical Co., Ltd.), epoxy resin (Epicoat #t1007, manufactured by Shell Chemical Co., Ltd.)
After kneading 2 parts of 26 parts of methyl ethyl ketone and 26 parts of Cellsolve Acetate in a porcelain ball mill for 48 hours, 14 parts of zinc oxide SA7.1 No. Add 2 parts of zinc sulfide and
'>Kio time The meat was kneaded in a porcelain ball mill, and the coating liquid was mixed with a bar caulk to form a ball with aluminum vapor deposited (
It was coated on an ester film (Metal Me manufactured by Toshisha Co., Ltd.) to a thickness of 16 μm and dried at 130° C. for 30 minutes to obtain a photoreceptor.

Next, a commercially available electrostatic copying paper testing device (1-1 Denki Co., Ltd. 5
P428), after performing corona discharge of -1-6K, V to positively charge it (maximum surface potential -+-650■
), 5I) Using a 2856° W lamp belonging to 428 in combination with Toshiba's 7Yapkanoto filter and interference filter, the sensitivity at 800 nm was determined to be 20μ, The T/C was 7ft. Also,
When exposed without a filter and using only a W lamp at an illuminance of 10 LuX, the sensitivity was 6 L Ll x seconds.

Next, 150V was applied to the aluminum base side of the photoconductor, and the photoconductor was placed in IEG Teveronova (positive polarity conductive liquid toner) manufactured by Minolta Business Machine Sales Co., Ltd. for 30 seconds for bias development, and then left at room temperature. The surface resistance was measured using an electrometer T 115 o OC insulation resistance measurement power supply (manufactured by Takeda Buken Co., Ltd.) in combination with a TR42 ultra-high resistance measurement sample box and found to be 1.5 x 10Ω.

Next, even when positive or negative corona discharge (±6 KV) was continuously applied to this bias-developed photoreceptor, its surface potential increased only by about +20 to +60 and -20 to -30, respectively.

From the above experimental results, if an image is formed on the above-mentioned photoreceptor using conductive liquid toner, the image area (part of the conductive liquid toner) and the non-image area have a large difference in acceptance potential under corona discharge, and electrostatic printing It will be easily understood that it is available as a version.

(Example 1) ε-type copper phthalocyanine (εCuP) manufactured by Toyo Ink Manufacturing Co., Ltd.
c) 4.5y and silicone resin (KR211 manufactured by Shin-Etsu Chemical Co., Ltd.)
) and acrylic resin (Aron S 100 manufactured by Toagosei Kagaku Co., Ltd.)
1') in a solid content weight ratio of 9:1.
After adding 67 parts of toluene to 8 parts and dispersing in a ball mill for 10 hours, photoconductive zinc oxide (Sakai Chemical Co., Ltd. WSA
ZEX2ooo) and 5 parts of reagent zinc sulfide (manufactured by Kanto Kagaku Co., Ltd.) were added, and the mixture was dispersed in a ball mill for another 6 hours. Using a rubber coater, a polyester film on which aluminum was vapor-deposited (Metal Mei, manufactured by Toshi Co., Ltd.) was mixed. ) to a thickness of 12μ, dried at 50℃ for 8 hours,
A photoreceptor with CuPc/ZnC1=0.3 (wt) was obtained.

Next, a commercially available electrostatic copying paper tester (SI
) 428) to positively charge it by corona discharge of +6 KV, then attach a Toshiba sharp cut filter and an interference filter to the 2 856 K W lamp attached to the SI) 428. When used in combination, the sensitivity at 800 nm was found to be 50 μJ/
It was d.

(Example 2) β-type copper phthalocyanine (βCuP manufactured by Toyo Ink Manufacturing Co., Ltd.)
C) 10 parts and silicone resin (K11211 manufactured by Shin-Etsu Chemical Co., Ltd.
) and acrylic resin (Aron S1001 manufactured by Toagosei Kagaku Co., Ltd.)
) in a solid content weight ratio of 9:1.
After adding 76 parts of toluene and dispersing in a ball mill for 10 hours, photoconductive zinc oxide (5AZ manufactured by Sakai Chemical Co., Ltd.) was added.
EX2ooo) and 1 part of the reagent zinc sulfide (manufactured by Kanto Kagaku Co., Ltd.) were added, and the mixture was dispersed in a ball mill for 6 hours. metal me) top [1
Coated to a thickness of 2μ and dried at 50°C for 8 hours, βCu
A photoreceptor with Pc/Zn0=0.5 (wi) was obtained.

Next, a commercially available electrostatic copying paper tester (Kawa 1) manufactured by Denki Co., Ltd. 5P
428), perform a corona discharge of -1-6KV to positively charge it, and then
56 W lamp in combination with Toshiba's Zyapkanoto filter and interference filter, 800 parts m
The sensitivity was determined to be 44 μJ/d.

(Example 3) Semiconductor laser beam printer LBP manufactured by Canon
-10 was modified and replaced with a photosensitive aluminum drum so that only the positive charger, exposure device, and developing device functioned, and the photosensitive aluminum drum used in the preliminary experiment was grounded and pasted. I was able to ask. The same positive polarity conductive liquid toner used in the preliminary experiment was placed in the developing device.

Next, an electric signal was input to operate the machine, and the steps of charging, exposing the image area with semiconductor laser light, and reversing development with conductive liquid toner were completed. Next, the developed photoreceptor was removed from the aluminum drum and dried with warm air to produce an electrostatic printing plate with conductive image areas.

This electrostatic printing plate was uniformly subjected to negative corona discharge (-6K V), and a negative type toner Li manufactured by Toyo Ink Mfg. Co., Ltd.
ofaxN-1 and carrier EFV 15 made by Nippon Tetsuko Co., Ltd.
0/250 developer using the magnetic plan method, paper was placed on the paper, and a positive corona discharge (+6KV) was applied to the paper.
was applied, the toner was electrostatically transferred onto paper, and a printed matter was obtained by heating and fixing.

(Example 4) The photoconductor used in the preliminary experiment was positively charged by corona discharge (+6KV), and a positive film original image was reverse image-projected at 10 Lux for 15 seconds using a 100W tungsten light source for enlarging, and the electrostatic latent was transferred onto the photoconductor. An image was formed and then a visible image was obtained using a one-component conductive magnetic toner having the following composition.

r Magnetite (black iron oxide) 65 parts The average particle size was 15μ, and the pressed powder had a resistance value of about 105Ωα.

This -component conductive magnetic toner landed on the electrostatic latent image area.

Next, heating was applied to melt and fix the -component conductive magnetic toner. This was used as a printing plate for electrostatic printing.

Using this printing plate for electrostatic printing, a printed matter was obtained by electrostatic printing using the same method and materials as in Example 6.

(Example 5) 40 parts of metal-free phthalonanine and 15 parts of mononitrocopper phthalocyanine were dissolved in 100 parts of 98% concentrated sulfuric acid with thorough stirring. Pour the dissolved solution into 10,000 parts of liquid water to precipitate the phthalocyanine composition, then filter and wash with water.
It was dried at 120° C. under reduced pressure.

100 parts of the thus obtained composition [11] and 100 parts of ε-type copper phthalocyanine (Lionol Blue ER) were mixed, and the mixture was dispersed in 5000 parts of methanol to form a uniform mixed dispersion. Then filter and under reduced pressure
It was dried at 20°C to obtain a mixture [11].

Next, 46 parts of the above mixture [11] and 18 parts of a mixture of silicone resin (KR211 manufactured by Shin-Etsu Chemical Co., Ltd.) and acrylic resin (Aron 51001 manufactured by Toagosei Chemical Co., Ltd.) at a solid weight ratio of 9:1. After adding 674 parts of toluene and dispersing in a porcelain ball mill for 30 hours, 12 parts of photoconductive zinc oxide (5AZEX2ooo manufactured by Sakai Chemical Co., Ltd.) and 6 parts of 1llIi lead sulfide (manufactured by Kanto Chemical Co., Ltd.) as a reagent were added. In addition,
Further, the mixed solution was dispersed for 10 hours, and then coated with a bar coater to a thickness of 14 μm on a polyester film on which aluminum was vapor-deposited (Metal Me, manufactured by Toshisha Co., Ltd.).
A photoreceptor was obtained by drying at ℃ for 50 minutes.

Using this photoreceptor, a printing plate for electrostatic printing was manufactured using the same method and materials as in Example 6.

(Example 6) 40 parts of copper phthalocyanine and 05 parts of tetracyanocobalt phthalocyanine were dispersed in 200 parts of glacial acetic acid, and 10 parts of 98% sulfuric acid was added dropwise while stirring. After stirring for 10 hours, the solids were separated daily. After further precipitating the phthalocyanine composition through ammonia gas, it was washed with water and then heated under reduced pressure for 12 minutes.
It was dried at 0°C.

The composition CIII thus obtained was mixed according to the following recipe.

(Composition [Ill] After grinding 3 parts or more of such a composition in a porcelain ball mill at room temperature for 24 hours, photoconductive zinc oxide (5AZE,
2 o o o) and 2 parts of the reagent zinc sulfide (manufactured by Kanto Kagaku Co., Ltd.) were added, and after further kneading, isocyanate (Desmodur N, manufactured by Nippon Polyurethane Industries Co., Ltd.) was added.
A mixed solution containing 2 parts of 75) was added using a bar coater to a thickness of 12 μm on a polyester film (Metal Me, manufactured by Toshisha Co., Ltd.) on which aluminum was deposited, and the mixture was heated uniformly to 120°C. The photoreceptor was obtained by placing it in an oven for 30 minutes.

Next, in a machine similar to that used in Example 3, the photoreceptor was attached to an aluminum drum.

The positive conductive liquid toner used in the preliminary experiment was placed in the developing device. - Next, an electrical signal was input to cause mechanical operation, completing the steps of charging, exposing the image area with semiconductor laser light, and developing with conductive liquid toner. Next, remove the developed photoreceptor from the aluminum drum.

By drying with warm air, a printing plate for electrostatic printing with conductive non-image areas was produced.

Positive corona discharge (+61<■) on this electrostatic printing plate
was uniformly applied, positive development was performed by the magnetic bluff method using a developer consisting of the negative type toner and carrier used in Example 6, paper was placed, and a positive corona discharge (-Toro K,
V), the toner was electrostatically transferred onto paper, and the toner was fixed by heating to obtain a printed matter.

(Example 7) 50 parts of trinitrocopper phthalocyanine was added to 60 parts of 9 parts% concentrated sulfuric acid.
0 parts with sufficient stirring. Add the dissolved liquid to 6 oz of water.
After the composition of α-type trinitrocopper phthalocyanine was precipitated, it was filtered, washed with water, and dried at 120° C. under reduced pressure. 100 parts of the composition thus obtained and 100 parts of ε-type copper phthalocyanine were dispersed in 5000 parts of methanol to form a uniform dispersion. Thereafter, it was filtered and dried at 120° C. under reduced pressure to obtain a mixture CIV].

6 parts of the above mixture [1v] and acrylic tree Ifi￥ (1-
A, rotap#3211) manufactured by Ichiki Shokubai Kagaku Kogyo Co., Ltd. 1
After dispersing 34.4 parts of methyl ethyl ketone, 1 part of n-butyl alcohol, 1 part of 2 parts of n-butyl alcohol, and 172 parts of cellosolve acetate in a porcelain ball mill for 30 hours, 9 parts of photoconductive zinc oxide (manufactured by Sakai Chemical Co., Ltd., 5AZEX2ooo) was added. Department,
12 parts of the reagent zinc sulfide (manufactured by Kanto Kagaku Co., Ltd.) was added and the mixture was dispersed for another 10 hours. Using a bar coater, the mixture was coated with 16 µm of carbon paper (thickness: 170 µm) coated with casein as a water-soluble resin. The photosensitive material was coated to a thickness of 100.degree. C. and dried at 70.degree. C. for 8 hours to obtain a photoreceptor.

Next, the above photoreceptor was attached to the same machine as in Example 6. The positive conductive liquid toner used in the preliminary experiment was placed in the developing device. Next, the machine was operated to produce a printing plate for electrostatic printing in which the image area was conductive by charging, exposing the non-image area to semiconductor laser light, and applying a regular image to the conductive liquid toner.

(Example 8) Tetranitrocopper phthalocyanine was prepared in the same manner as in Example 5, and a mixture [V'll] was prepared.

6 parts of the above mixture [V], 15 parts of acrylic resin (A manufactured by Nippon Shokubai Kagaku Kogyo Co., Ltd., rO1ap #3211), 5 parts of methyl ethyl ketone, 18.4 parts of n7' methyl alcohol,
184 parts of Cellsolve Acetate was mixed with 30 parts in a porcelain ball mill.
After time dispersion, 9 parts of photoconductive zinc oxide (5AZEX2000 manufactured by Sakai Kagaku Co., Ltd.) and 12 parts of the reagent zinc sulfate (manufactured by Kanto Kagaku Co., Ltd.) were added, and the mixed solution was dispersed for another 10 hours. The photoreceptor was coated to a thickness of 15 .mu.m on carbon paper (thickness 170 .mu.m) coated with casein as a water-soluble resin using a turret, and dried at 70.degree. C. for 8 hours to obtain a photoreceptor.

Next, in a machine similar to that of Example 1, the photoreceptor was pasted, and the positive conductive liquid toner used in the developing device was put therein. Next, the machine is operated, and the non-image area is charged, exposed to semiconductor laser light, and reversed developed with conductive liquid toner, so that the non-image area becomes conductive and has a light sensitivity of 1-11.
Differences ---- Apparatus -wi=s- are shown in Table 1. The samples were measured using an electrostatic copying paper tester (5P428 manufactured by Kawaguchi Electric Co., Ltd.).
), the corona family t of + 6 K V is 10711
After applying a charging speed of /min, 10 seconds later, a 2856° W lamp was used in combination with a Toshiba sharp cant filter and an interference filter, and 4tt W was applied.
/clft was given, and the time taken for the surface potential to decrease by half was measured to determine the photosensitivity.

Table 1 Spectral sensitivity characteristics (μJ/ffl)

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is an explanatory diagram showing a state in which a photoreceptor is charged by corona irradiation, and FIG. 2 is an explanatory diagram showing a state in which a photoreceptor is exposed to semiconductor laser light to form an electrostatic latent image. FIG. 6 is an explanatory diagram showing a photoconductor subjected to reversal development with conductive toner, FIG. 4 is an explanatory diagram showing a photoconductor subjected to regular development with conductive toner, and FIGS. FIG. 3 is an explanatory diagram showing a fixed photoreceptor. (1)...Electroconductive support (2)...Photoconductive layer (
3)...Photoreceptor (4)...Semiconductor laser light (5)
...Conductive toner f6)--Conductive part (7)-
... Insulating part (8) ... Printing plate patent applicant for electrostatic printing Toppan Printing Co., Ltd. (and one other person) @Figure 1

Claims (2)

[Claims] (1) As a photoconductor, a photoconductive layer in which a phthalocyanine pigment, zinc oxide, and zinc sulfide are dispersed in a binder resin is provided on a conductive support, and the photoconductor is charged 1-1.
A printing plate for electrostatic printing, which is formed by exposing iron to form an electrostatic latent image, and then developing and fixing the electrostatic latent image using a conductive toner. (2) The printing plate for electrostatic printing according to claim 1, characterized in that imagewise exposure is performed using semiconductor laser light modulated by an electric signal.