JPS5897052A - Photoreceptor with storage function - Google Patents

Abstract

PURPOSE:To repeat transfer many times and to regenerate and use a photoreceptor many times by forming a phthalocyanine layer and a polyvinylcarbazole layer contg. an aliphatic halogenated hydrocarbon, an acylhalide compound or the like on an electrically conductive support in order. CONSTITUTION:A phthalocyanine layer having 0.01-10mum thickness is formed on an electrically conductive support by vapor-depositing alpha-metal-free phthalocyanine, metallic phthalocyanine, halogenated phthalocyanine or the like or applying a dispersion of the phthalocyanine after optionally forming a layer of Al2O3, polycarbonate or the like causing no insulation on the support. On the phthalocyanine layer a polyvinylcarbazole layer contg. >=1 kind of compound selected from aliphatic halogenated hydrocarbons, acyl halide compounds such as acetyl chloride, halogenated ketone compounds and hydrogen donating compounds such as acetic acid, phthalic acid and phosphoric acid by 0.01-10wt% basing on the amount of polyvinylcarbazole is formed in 1-30mum thickness to obtain a photoreceptor with a storage function and high sensitivity. When the receptor is charged and exposed once, copying can be repeated several 100 times, and the receptor can be regenerated by heating at about 150 deg.C for several sec and reused many times.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a memory photoreceptor, and more particularly to a memory photoreceptor for electrophotography having improved memory performance.

The electrophotographic copying process consists of four steps: ■ charging the photoreceptor, ■ exposing the original image to light, ■ developing with toner particles, and ■ transferring to the multiple transfer body, and transfers a large number of sheets. Sometimes, a method of repeating this process over and over again is adopted as a general method (・ru.

On the other hand, as a method for transferring a large number of sheets, we take advantage of the phenomenon that when exposure is performed through the original image in (2), the image is stored semi-permanently. Multi-sheet transfer is being considered.

Such a system is of interest because it reduces the transfer time due to the omission of an exposure step and prevents deterioration of the photoreceptor due to exposure.

A copying method developed for this purpose and a photoreceptor used therein are disclosed in JP-A-51-13242゜JP-A-51-
Examples using a zinc oxide photoreceptor such as No. 13245, and a memory photoreceptor comprising a leuco dye and 2,4,7-dolinitro-9-fluorenone, such as JP-A-52-4839, are also known. Furthermore, in JP-A-50-86347, a photoconductive layer (polyN vinyl carbazole layer) is provided on a conductive support, and the surface of this photoconductive layer is coated with a halogenated keto compound and/or a halogenated acyl compound. A memory photoreceptor obtained by treating with a solution of
-86348 has a photoconductive layer (po+) on a conductive support.
A memory photoreceptor is known in which a N-vinyl carbazole layer is provided and the surface of this photoconductive layer is treated with an aliphatic halogenated hydrocarbon.

However, such memory photoreceptors have low sensitivity, require long-time exposure to strong light sources, have poor memory properties, cannot withstand multiple copies of several hundred sheets, and are difficult to recycle. The usability (erasing an image once stored and storing another image) is also poor, and there are problems such as the photoreceptor deteriorating after being reused several times.

The inventors of the present invention have conducted intensive research aimed at obtaining a memory photoreceptor with excellent memory properties and excellent reusability, and have found that a multilayer photoreceptor using phthalocyanine pigments meets this purpose. We discovered this and arrived at this invention.

That is, the present invention provides a conductive support, a phthalocyanine layer provided on the conductive support, and an aliphatic halogenated hydrocarbon, a halogenated acyl compound, a halogenated keto compound, and hydrogen provided on the phthalocyanine layer. This is a memory photoreceptor characterized by comprising a polyvinyl carbazole layer containing at least one donor compound. The memory photoreceptor constructed in this way exhibits transferability of 500 times or more, and is also reusable, whereas conventional memory photoreceptors have a memory property of at most 100 times, that is, they do not have the ability to transfer multiple sheets. More than 50 times can be obtained.

The present invention will be explained in detail below. As the conductive support of the present invention, a conductive substrate such as a metal plate such as aluminum or nickel, a metal-deposited film, or conductive treated paper is used.

A phthalocyanine layer is provided on a conductive support, and examples of phthalocyanine that can be used in the present invention include metal-free phthalocyanine, magnesium phthalocyanine, lead phthalocyanine, vanadium phthalocyanine, chromium phthalocyanine, aluminum phthalocyanine, iron phthalocyanine, cobalt phthalocyanine, and nickel phthalocyanine. Examples include metal-free phthalocyanines, metal phthalocyanines, and hyhalogenated and sulfonated phthalocyanine derivatives such as, and crystal forms thereof are not particularly limited, including α-type, β-type, γ-type, δ-type, and ε-type.

Various crystal types such as χ (kushii) type, π type, ρ type, and x (X) type are employed. Among these, α-metal-free phthalocyanine is particularly desirable, but it is not necessary to limit it to α-metal-free phthalocyanine in the present invention.
・. The appropriate thickness of this phthalocyanine layer is from 0.01 μm to 10 μm; if it is less than 0.001 μm, the memory property will be weak, and if it is more than 10 μm, the Capri phenomenon will be strong.

- This phthalocyanine layer can be formed by vapor deposition or by coating and drying a dispersion (with a small amount of binder if necessary). A polyvinylcarbazole film is provided on the phthalocyanine layer formed in this way,
At least one of an aliphatic halogenated hydrocarbon, a halogenated acyl compound, a halogenated keto compound, and a hydrogen-donating compound is added to this polyvinylcarbazole in a range of 0.01 to 10 parts by weight per 100 parts by weight of the polyvinylcarbazole. As for the method of impregnation, when a solution of polyvinylcarbazole is prepared, a homogeneous solution or suspension is prepared by dissolving the polyvinylcarbazole at the same time, and then it is coated and dried.

The film thickness of the polyvinylcarbazole in this case is 1 to 30 .mu.m, preferably 2 to 20 .mu.m. If it is less than 1 .mu.m, the contrast will be poor, and if it is more than 30 .mu.m, the resolution will be decreased.

The aliphatic halogenated compounds used here include carbon tetrachloride, trichloroethane, and carbon tetrabromide.

Chloroform, hexachloropropane, tetrachloroethylene, dichlorosifuromeethane, yl:') vinyl chloride, polyvinylidene chloride, etc. can be used.

Chloracetone as a halogenated keto compound.

Bromoacetone, bromoacetophenone, tribromoacetophenone, etc. can be used.

As the halogenated acyl compound, acetyl chloride, acetyl bromide, chloroacetyl chloride, bromoacetyl bromide, chlorobenzoyl chloride, etc. can be used.

In addition, organic and inorganic acids are used as hydrogen-donating compounds, and examples of organic acids include acetic acid, trichloroacetic acid, benzoic acid,
Phthalic acid, tetrabromophthalic acid.

Maleic acid, phenol, nitrophenol, picric acid, phthalic anhydride, maleic anhydride, brominated maleic anhydride, etc. can be used, and as the inorganic acid, hydrochloric acid, sulfuric acid, phosphoric acid, boric acid, etc. can be used.

Memory performance is further improved by providing an insulating blocking layer between the conductive support and the phthalocyania layer. Thus, the invention further comprises: an electrically conductive support provided with an insulating blocking layer; a phthalocyanine layer provided on the insulating blocking layer; and an aliphatic halogenated hydrocarbon provided on the phthalocyanine layer. Provided is a memory photoreceptor comprising a polyvinyl carbazole layer containing at least one of a halogenated acyl compound, a halogenated keto compound, and a hydrogen-donating compound.

The insulating blocking layer serves to block charge injection into the 7-lysocyanine layer from the grounded support; it is sufficient that the blocking layer is thick enough to withstand the applied voltage, e.g. in typical electrophotography. At this time, the applied voltage is 200~
In order to insulate this, an aluminum oxide layer of 0.01 to 0.1 μm is required.

When using a metal oxide as an insulating blocking layer, it is preferable to actively oxidize the surface of a conductive material such as a metal plate as described above by a method such as anodic oxidation in an aqueous solution. be. Insulating materials other than metal oxides, such as aluminum oxide, can also be used, such as polycarbonate resins, polystyrene resins, epoxy resins, polyester resins, etc., which can be applied to the conductive substrate.

The memory photoreceptor thus obtained is exposed to light via an image, the image is memorized, and when corona charging is performed, areas other than the exposed areas are selectively charged, which is then developed with toner and transferred. To perform subsequent transfers, corona charging, toner development, and transfer may be repeated.

The conductive memory stored in this manner can also be erased, and by heating it at 150° C. for a few seconds, it can be reused as a completely new photoreceptor.

As already mentioned, the present invention comprises a phthalocyanine layer on a conductive support, and further layers of an aliphatic halogenated hydrocarbon, a halogenated acyl compound, a halogenated keto compound, and a hydrogen donating compound. A layer structure in which a layer of polyvinyl carnoxole containing a small amount of polyvinylcarnoxole (including one type of polyvinyl carnoxole) is provided, or a layer structure in which an insulating blocking layer is further provided between the layer of the conductive support and the 7 talocyanine layer. By doing so,
It provides high memory performance, high sensitivity, and even printing characteristics that could not be obtained with conventional memory photoreceptors.

The following method was adopted to evaluate the characteristics of the memory photoreceptor thus obtained.

■ Heat the newly created memory photoconductor at 150°C for 5 seconds to make the photoconductor clean.

■ Place the clean photoreceptor obtained in step 5 in a dark place.
Carry out KV corona discharge (・Carry out negative charging (・Measure the charging voltage at that time).

■ After exposing the clean photoreceptor obtained in ■
The KV is repeatedly charged negatively by corona charging, and the change in negative charging voltage due to one repetition of corona charging is observed and compared with the value in the dark place. The ideal memory photoreceptor is one in which the charging voltage does not increase even if corona charging is performed after exposure.
In reality, as the corona charging time increases and the number of times of charging increases, the voltage gradually increases, and finally rises to a voltage similar to the charging voltage in the case of no exposure.

The present invention will be explained below with reference to Examples.

Example 1 An aluminum sheet whose surface was roughened with No. 800 sandpaper was placed in a 2% aqueous oxalic acid solution, and the amount of current applied was 1.
Anodized by 67 coulombs/1o cm square.

α on the oxidized surface of this aluminum sheet (thickness 100 μm)
- Disperse 2 g of metal-free phthalocyanine in a dichloroethane solvent at 100 eC, and after uniformly dispersing it by ultrasonication, use an applicator to form a 1-2 μm thick α
- Provided with a metal-free phthalocyanine layer. Next, 1.
1.2.2-A mixed solution obtained by dissolving trichloroacetic acid 601A9 in 100ml of a 10% solution of polyvinylcarbazole dissolved in a tetrachloroethane solvent was applied onto the α-metal-free phthalocyanine layer using an applicator. It was air-dried day and night in the dark to form a polyvinyl carbazole layer with a thickness of 10 μm.

The photoreceptor thus obtained was heated at 150°C for 91 hours.
Heat aging was performed in a dryer to obtain a memory electrophotographic photoreceptor.

In order to evaluate the memory characteristics of the photoreceptor thus obtained, the photoreceptor was first heated at 1.50'C for 5 seconds, and then electrostatically charged to measure the charging characteristics.

5tatic Paper Analyzer (S
Corona charging voltage -5
, 5 KV for 0.25 seconds, and then the surface potential when not exposed to light was measured. Next, rotate the photoreceptor again to 150°.
C, after heating for 5 seconds, the light intensity was 5 m with a mercury lamp.
After exposing the entire surface to light for 1 second at an intensity of W/Cm2, corona charging was performed in the same manner as above (・, and the surface potential after light irradiation was measured.Next, no exposure was performed, and the corona charging and surface potential were The measurement was repeated and the recovery of the surface potential due to repeated corona charging was measured to evaluate the memory characteristics.The measurement results are shown in Figure 1.

As an evaluation of memory characteristics, the recovery rate of the surface charge potential after 100 times of corona charging (surface charge potential after 100 times of corona charging after light irradiation and 150'c).

This photoreceptor had a charge potential of 024 (expressed as a ratio of the surface charge potential when charged in an unexposed state after heat treatment by heating for 5 seconds).

Comparative Example 1 A photoreceptor was prepared in the same manner as in Example 1, except that the α-metal-free-phthalo-7-anine layer was not provided. We obtained a memory electrophotographic photoreceptor laminated with .
The same procedure as in Example 1 was carried out, and the obtained results are shown in FIG.

The recovery rate after 100 times of corona charging was 0.90.

Comparative Example 2 A photoreceptor was prepared in the same manner as in Example 1, except that instead of phthalocyanine in Example 1, Shiroshian Blue, which is famous as a material for the carrier generation layer of ordinary electrophotographic photoreceptors, was used. A memory electrophotographic photoreceptor was obtained.

When the memory characteristics of this photoreceptor were evaluated in the same manner as in Example 1, the recovery rate after 100 corona electrifications was 0.80.

Example 2 Example 1 except that instead of the anodized aluminum sheet, an aluminum sheet whose surface was naturally oxidized after being left in the air was used.
A memory electrophotographic photoreceptor was obtained in the same manner as above. When the memory characteristics were evaluated according to Example 1, the recovery rate after 100 corona charges was 0.29.

Example 3 As a conductive support, gold,
Alternatively, a J phthalocyanine layer and a polyvinylcarbazole layer were laminated in the same manner as in Example 1 on a thin layer of varadilum to obtain an electrophotographic memory photoreceptor. When the memory characteristics were evaluated in the same manner as in Example 1, when gold or varadilum metal was used as the electrode, the recovery rate after 100 corona electrifications was 0.48.

Example 4 In Example 1, instead of using trichloroacetic acid, carbon tetrabromide and hexachloroacetone were used.
119 were used to obtain memory electrophotographic photoreceptors. When the memory properties were measured by the same method as in Example 1, the recovery rate after 100 corona charging was 0.27 in the case of carbon tetrabromide addition, and 0.29 in the case of hexachloroacetone addition.

Comparative Example 3 a- No metal-free phthalocyanine layer was provided. A photoconductor was prepared in the same manner as in Example 2.
．． (True or hexachloroacetone, respectively, % J.
*Mo]j-type electrophotographic photoreceptors were obtained.

When the door molying characteristics were evaluated in the same manner as in Example 1, the recovery rate after 10,0 times of corona charging was 0.94 in the case of carbon tetrabromide addition and 0.98 in the case of hexachloroacetone addition. .

Example 5 Implementation'? α-copper phthalocyanine 1 ε was deposited on an aluminum sheet anodized using the same process as lJi.
- Uniformly disperse 2 g each of copper phthalocyanine, monochloro-α-copper phthalocyanine, and β-copper phthalocyanine in 10 Q cc of dichloroethane solvent by ultrasonication,
A phthalocyanine layer with a thickness of 1 to 2 μm was formed using an applicator, and a polyvinyl carbazole layer containing trichloroacetic acid having the same composition as in Example 1 was laminated thereon to obtain a "memory electrophotographic photoreceptor." Evaluation was carried out in the same manner as in Example 1, and the obtained results were 0.31 for α-copper phthalocyanine, 0.34 for ε-phthalocyanine, 036 for monochloro-α-copper phthalocyanine, and 0.36 for β-copper phthalocyanino. It was 046.

Example 6 The memory electrophotographic photoreceptor obtained in Example 1 was heat-treated at 150'C for 5 seconds, and then a light intensity of 5m was applied.
Image exposure was performed for 1 second using a mercury lamp with an intensity of W/cm2. Next, after performing corona charging at -5.5 KV for 0.25 seconds, magnetic brush development was performed using positive polarity electrophotographic toner to form a toner image in the non-exposed area, and then transferred to plain paper. A good electrophotographic copy image was obtained by heat fixing. Approximately 300 copies were obtained by repeating the negative corona charging, toner development, and transfer operations without any image exposure.The exposed white area of these copies was Due to good memory retention, the copied image was good with no fog due to toner adhesion.

Then, by performing the same heat treatment as above.

The latent image was erased, image exposure was possible again, and the above copying process was repeated to obtain the same number of copies as above.

The number of reuses of the memory photoreceptor after such heat treatment was 100 times or more.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the number of times of corona charging and the recovery rate of surface charge potential measured for the photoreceptors obtained in Example 1 and Comparative Example 1. Applicant Asahi Dow Co., Ltd. Agent Yutaka 1) Yoshio

Claims (1)

[Scope of Claims] (11) A conductive support, a phthalocyanine layer provided on the conductive support, and an aliphatic halogenated hydrocarbon, a halogenated acyl compound, and a halogenated acyl compound provided on the phthalocyanine layer. A memory photoreceptor comprising a polyvinyl carbazole layer containing at least one of a keto compound and a hydrogen-donating compound. (2) A conductive support provided with an insulating blocking layer, and the insulating blocking layer. A phthalocyanine layer provided on the phthalocyanine layer, and a polyvinyl carbazole containing at least one of an aliphatic halogenated hydrocarbon, a halogenated acyl compound, a norogenated keto compound, and a hydrogen-donating compound, further provided on the phthalocyanine layer. A memory photoreceptor characterized by comprising layers.