DE1797342B2 - ELECTROPHOTOGRAPHIC RECORDING MATERIAL - Google Patents

Description

The invention relates to an electrophotographic recording material, in particular an optical disk for the xerography, from an electrically conductive layer support, an intermediate layer with an insulating Binder and a pigment, and a photoconductive layer which acts as a pigment Phthalocyanine and a layer containing selenium as a photoconductive layer, according to Patent 15 97 877.

It is known that certain photoconductive substances can be deposited on the surface by electrostatic processes Images are generated and developed. The basic described in US Pat. No. 2,297,691 Electrophotographic process consists in that a photoconductive layer is uniformly charged and then exposed with a chiaroscuro image, whereby the charge is diverted in the exposed areas of the layer. That on the shift The latent electrostatic image formed corresponds to the light-dark image in terms of its charge distribution. Further For example, an electrostatic latent image can be formed on the plate by imagewise charging. In both Cases, the image is made visible by the deposition of a finely divided developer composed of a There is a dye, the so-called toner, and a carrier for the toner. The powdered developer will attracted by the charge-bearing areas of the layer, thereby evolving from the latent electrostatic Image gives a corresponding powder image. This powder is ultimately used on paper or other image carriers transfer. It can then be permanently fixed on the paper by heating or other fixing methods will. There is also the option of the powder image

to fix directly on the image plate.

From the previously known photoconductor materials selenium has proven to be the most suitable. Glass-shaped However, selenium has the disadvantage that its sensitivity largely to the ultraviolet, blue and green area of the spectrum is limited. This narrowed color sensitivity makes particular the production of copies difficult, those of originals colored red-black, blue-yellow or blue-orange should be produced.

In addition, when photoconductive layers containing selenium are used, adhesion problems arise the recording material and the substrate. Furthermore, different coefficients of thermal expansion in the case of the substrate and the photoconductive one Layer, to peel off the photoconductive layer or lead to the formation of cracks in the same. Is a selenium-containing layer on a conductive substrate applied, there is a barrier between the

selenium-containing layer and the substrate are required. The selection of the interlayer material must depend on the required adhesion and also on the fact that of the intermediate layer in the Excellent insulation properties and dark

less good non-conduction properties are expected when exposed to visible light.

According to the teaching of the main patent 15 97 877 (DT-AS 15 97 877) the intermediate or barrier layer has a phthalocyanine pigment and serves as a photoconductive one

Layer a selenium-containing material. Despite the many related by the use of phthalocyanine However, advantages that can be achieved with an amorphous inorganic binder are also some disadvantages available. The carefully manufactured toners often react with the phthalocyanine surface and leave A further disadvantage is that a phthalocyanine coating is practically impossible with conventional office materials, such as Brushes made of rayon or rabbit fur, clean. Furthermore, phthalocyanine has in a recording material the disadvantage that, as a result of an uncontrollable increase in the sensitivity during operation, the can lead to overexposure of the recording material, is decomposed. Also be during of the company receive increasingly less dense images.

The invention is based on the object of providing a recording material of the type mentioned at the beginning to improve even further and, in particular, to ensure that an effective Toner transfer and an adequate cleaning option is guaranteed.

This object is achieved according to the invention in that the recording material has a 10 to 50, preferably 10 to 15 μm thick intermediate layer and a 0.5 to 5, preferably 1 to 3 μΐυ thick selenium-containing Layer contains.

In the case of the recording material according to the invention, thanks to the layer containing oil, there is an excellent one Ensures sensitivity to the blue, green and ultraviolet parts of the spectrum, while the intermediate layer containing phthalocyanine exhibits excellent sensitivity to the brings along the red and near infrared regions of the spectrum. Can be used as a binder resin for the intermediate layer a resin can be selected that has optimal adhesion between the selenium-containing layer and brings about the support. By coating the containing the phthalocyanine and the binder

Intermediate or barrier layer with the relatively thin selenium-containing layer, an electrophotographic recording material with high sensitivity is created, which is an excellent sound transmission medium and can be reused in can be cleaned easily. The recording material according to the invention shows a hardly noticeable Wear and tear and suffers almost no decomposition, not even after camouflaging cycles of use. In addition, the plate according to the invention shows no increase in sensitivity in operation and no associated generation progressing less dense images.

Any suitable material can be used as the conductive support. Typical materials for this purpose are metals such. B. aluminum, brass, stainless steel, copper, nickel or zinc. Glasses or plastic substrates provided with a conductive coating are also suitable. Also managerial made paper can serve as a substrate.

According to a preferred embodiment of the invention, the recording material contains, as phthalocyanine, the form, the X form, but preferably the polymorphic crystalline X form, or a mixture of both forms of metal-free phthalocyanine. It has been found to be advantageous that the intermediate layer consists of 0.5 to 15, preferably 1 to 10 parts by weight of binder per part by weight of phthalocyanine. A polycarbonate is advantageously chosen as the binder. According to a further preferred embodiment of the invention, the selenium-containing layer consists of selenium or a mixture of selenium and arsenic.

The intermediate layer can be made from any suitable phthalocyanine that is present in an insulating binder is distributed, exist. Typical phthalocyanines are aluminum phthalocyanine, aluminum polychlorophthalocyanine, Antimony phthalocyanine, barium phthalocyanine, beryllium phthalocyanine, cadmium hexadecachlorphthalocyanine, Cadmium phthalocyanine, calcium phthalocyanine, cerium phthalocyanine, chromium phthalocyanine, cobalt phthalocyanine, Cobalt chlorophthalocyanine, copper-4-aminophthalocyanine, copper bromophthalocyanine, Copper-4-chlorophthalocyanine, copper-4-nitrophthalocyanine, Copper phthalocyanine, copper phthalocyanine sulfonate, copper polychlorophthalocyanine, deuterium phthalocyanine, Dysprosium phthalocyanine, erbium phthalocyanine, europium phthalocyanine, gadolinium phthalocyanine, Gallium phthalocyanine, germanium phthalocyanine, hafnium phthalocyanine, halogen-substituted phthalocyanine, holmium phthalocyanine, indium phthalocyanine, Iron phthalocyanine, iron polyhalophthalocyanine, lanthanum phthalocyanine, lead phthalocyanine, lead polychlorophthalocyanine, Cobalt hexaphenyl phthalocyanine, copper pentaphenyl phthalocyanine, lithium phthalocyanine, Lutetium phthalocyanine, magnesium phthalocyanine, manganese phthalocyanine, mercury phthalocyanine, molybdenum phthalocyanine, Naphthalocyanine, neodymphthalocyanine, nickel phthalocyanine, nickel polyhalophthalocyanine, Osmium phthalocyanine, palladium phthalocyanine, palladium chlorophthalocyanine, alkoxphthalocyanine, Alkylaminophthalocyanine, alkyl mercaptophthalocyanine, aralkylaminophthalocyanine, aryloxyphthalocyanine, Aryl mercaptophthalocyanine, copper phthalocyanine piperidine, cycloalkylaminophthalocyanine, dialkylaminophthalocyanine, Diaralkylaminophthalocyanine, dicycloalkylaminophthalocyanine, hexadecahydrophthalocyanine, Imidomethylphthalocyanine,!, 2-naphthalocyanine, 2,3-naphthalocyanine, octaaxaphthalocyanine, sulfur phthalocyanine, tetraazaphthalocyanine, tetra-4-acetylaminophthalocyanine, Tetra-4-aminobenzoylphthalocyanine.Tetra ^ -aminophthalocyanine.Tetrachloromethylphthalocyar.in, Tetradiazophthalocyanine, tetra-4,4-dimethyloctaazaphthalocyanine, tetra-4,5-diphenylenedioxydphthalocyanine, Tetra ^ .S-diphenyloctaazaphthalocyanine, Tetra (6-methyl-benzothiazoyl) phthalocyanine, tetra-p-methylphenylaminophthalocyanine, tetramethylphthalocyanine, Tetra-naphthotriazolyl phthalocyanine, tetra-4-naphthyl phthalocyanine, tetra-4-nitrophthalocyanine, Tetra-peri-naphthylene ^ .S-octaazaphthalocyanine, Tetra ^ -phenylenoxydphthalocyanin, Tetra ^ -Phenyloctaazaphthalocyanin, Tetraphenylphthalocyanin, Tetraphenyl phthalocyanine, tetracarboxylic acid, tetraphenyl phthalocyanine tetrabarium carboxylate, Tetraphenyl phthalocyanine, tetraphenyl phthalocyanine tetracalcium carboxylate, tetrapyridyl phthalocyanine, Tetra-4-trifluoromethyl mercaptophthalocyanine, tetra-4-trifluoromethyl phthalocyanine, 4,5-thionaphthenoctaazaphthalocyanine, platinum phthalocyanine, potassium phthalocyanine, rhodium thaiocyanine, samarium phthalocyanine, Silver phthalocyanine, silicon phthalocyanine, sodium phthalocyanine, sulfonated phthalocyanine, thorium phthalocyanine, Thulium phthalocyanine, tin chlorophthalocyanine, tin phthalocyanine. Titanium phthalocyanine, Uranium phthalocyanine, vanadium phthalocyanine, yucibium phthalocyanine, Zinc chlorophthalocyanine, zinc phthalocyanine and mixtures of the aforementioned Compounds, dimers, trimers, oligomers, polymers, Copolymers or mixtures thereof.

While the intermediate layer can be any suitable phthalocyanine, it is it is preferable to use a metal-free phthalocyanine which has a relatively high photosensitivity. Of the various polymorphic forms of metal-free phthalocyanines are the α and "X" forms to be preferred because they are known to have a very high photosensitivity. Optimal results are with the polymorphic crystalline "A '" - form of a metal-free phthalocyanine (cf. the British Patent 11 16 553) obtained, since this form has the highest photosensitivity together with the the slightest dark discharge. The various forms of metal-free phthalocyanine can be found in easily differentiate by comparing their X-ray diffraction patterns and / or their infrared spectra (see French patent specification 15 08 173).

The phthalocyanine can be in finely powdered form in the binder material in any suitable ratio of Photoconductors to binders are present. On a weight basis of phthalocyanine pigment / dry binder the suitable range is from about 2: 1 to about 1:15. Optimal results are obtained when ratios from about 1: 4 to about 1:10 are maintained. Hence is this area is most preferable. The phthalocyanine pigments can be dissolved or molten binder can be incorporated by any suitable method, for example by Stirring with strong shear, preferably grinding at the same time. From such methods be a grinding in a ball mill, a grinding in a mixer, a sand grinding, a stirring by means of ultrasound, a hollow speed mixing and any suitable combination of these methods is mentioned. In addition to the addition of the phthalocyanide particles to the dissolved or

Molten binder material can also be added to the dry powdered binder material or a slurry of the binding material prior to heating it or its dissolution can be added.

The binder material for the phthalocyanine pigment in the intermediate layer can be any suitable, im essential insulating film-forming organic resin. Preferably the binder has good adhesion to selenium and mixtures containing selenium, as well as to the selected one conductive substrate material. As mentioned above, the resin may be primarily in terms of Adhesion to the respective selenium-containing layer and to the respective substrate material be selected, regardless of the insulating Properties that it possesses when exposed to light. Typical insulating film-forming binders are urea and melamine-aldehyde resins, Polyimide resins, polycarbonate resins, silicone resins, epoxy and epoxy / phenol resins, polyvinyl carbazole as well as Polyester. When used in front of polycarbonate resins, optimal adhesion to both the Substrates as well as the overlying selenium-containing layer achieved, in addition, a excellent photosensitivity is observed. Therefore, polycarbonates are used as binders for the Phthalocyanine is preferred in the intermediate layer.

The pigment, binder, and solvent slurry (or the pigment / binder melt! - ze) can be applied to the substrate according to any of the usual Spreading or layering methods are applied, for example by spraying, floating, No application, electrostatic coating, dipping, application by means of a reversing roller or the like. After the intermediate pigment / binder layer has been formed, the selenium containing layer can be added can be applied by any suitable method. A vacuum evaporation coating is preferred because in this way a smooth and uniform layer in the amorphous state is achieved will.

The following examples illustrate the invention without restricting it. All parts and percentages Unless otherwise stated, are based on weight.

example 1

3 electrographic plates are in following Way made: 5c

a) A 125 (im thick aluminum foil is covered with a 15 ^ layer of an amorphous selenium by vacuum vapor deposition according to that in the US patent 29 70 £ 06 method described coated.

b) A coating solution is prepared by dissolving about 2 parts of a polycarbonate resin in about 10 parts of dioxane and about 10 parts of dichloromethane. About 0.3 parts of metal-free phthalory? .- r, ₀ nin in the "X" form are added to this solution. This solution is then slurried onto an aluminum substrate to a dry thickness of approximately 15 μ. The layer of pigment and binder is dried for a period of approximately <> 5 hours at a temperature of approximately 100.degree.

c) The procedure described under (b) is

repeated. After drying <n pigment and binder; is made of amorphous selenium over the Pht! alc layer by vapor deposition in the Va.

Each of the 3 plates is then applied to a positive voltage, corona discharge unit, which is kept at low levels, over the plates is approximately ire, as described in the US Patentsi.:iril. Each plate is irradiated with white light by means of a tungsten Qi ./2 with a color temperature of un; .efä. The light-induced discharge plate is measured continuously by means of an electrometer. Each plate wi, i a again to a positive voltage i.ufg irradiated by means of a ten between light source and Pia filter. The filter can not; efä visible light with wavelengths earlier than 630 mi. but less than 1% by 5f The sensitivity of each c; r to the red light is measured.

The results show that all of the ipi is sensitive to light in the blue, green uid of the spectrum to which R. tbi responds to a very low degree. In contrast, the Phth-Lot is in the red and infrared range lighter than in the UV range. The side panel is sensitive essential to the whole point of view .re appeals.

The phthalocyanine plate (not over the selenium-coated phthalocyanine 3la then each electrostatically with a corona discharge device, which works at a voltage of about 6000 volts: t, \ plates are then for about 1 second using a slide in an enlarger , ..he f /, which is working, provided 4,5-lens and a tungsten light source, irradiates the ί jf incident light amount is ungefi hr obtained electrostatic images w (RDE ßend by cascading electroscope;. ch rungsteilchen π over their surfaces ch US Patent specification 26 18 551 described nei developed. The powder formations obtained were transferred electrostatically to paper recording sheets of US Pat Results show the 3c layered plate produces copies that lose lan sai The results are about the 5th copy after the 'sz if approximately 100 copies were to be made with the eye, the image is extremely light and pale on the uncoated plate. When using the selenium-coated phthalocyanine, on the other hand, the 1000th Bi i produced is of the same quality as the first image, with the image corresponding to the projected image. The flatness under operating conditions is influenced by the coating. While the never itt plate is increasingly sensitive to some charge-ZLöschungszykl η;

in the case of the plate coated with selenium only a small amount Increase in sensitivity during operation. Even if this is also for the outsider one advantage of an uncoated panel over a coated panel appears to be nevertheless not the case, since an uncontrolled increase in sensitivity occurs with each cycle, whereby the uncoated plate is irradiated to the extent necessary for the plate Measure exceeds. This overexposure in turn results in the creation of less dense images. at However, the use of the selenium-coated plate increases the sensitivity only slowly, so that none Overexposure of the plate occurs and consequently no change in the quality of the image produced can be observed is.

After a few cycles of charge, irradiation and transfer using Figure 2 above mentioned plates (uncoated phthalocyanine plate and selenium-coated phthalocyanine plate) an attempt is made to make each of the plates using rabbit fur as well as a Cleaning rayon brush. This occurs when removing toner or the like from the uncoated Plate experienced considerable difficulties while the coated plate was thoroughly cleaned in an instant can be.

Example 2

2 electrographic plates are made as follows:

(a) A 20 ^ layer of amorphous selenium is applied in vacuo to a brass foil with a thickness of 50 μ evaporated.

(b) A coating solution is prepared by dissolving about 4 parts of a polycarbonate resin in about 20 parts of toluene. To about 10 parts of this solution is added about 1 part of the α-form of metal-free phthalocyanine. A brass foil with a thickness of 50 μ is coated by dipping with the mixture to a dry thickness of approximately 17 μ. The resin is then dried by heating to approximately 100 ^° C. for a period of approximately 1 hour. A layer of amorphous selenium is then vacuum evaporated onto the resin surface to a thickness of approximately 5 μ.

Each foil is then bent over a radius of 50 mm. The film on which the selenium layer sits directly on the brass surface suffers cracks in the selenium, with considerable flaking starting The substrate is sticking.

Example 3

A coating solution is prepared by dissolving about 1 part of a silicone resin in about 6 parts of xylene. About 03 parts of metal-free phthalocyanine in the "X" form are added to this solution. This solution is sprayed onto an aluminum substrate to a dry film thickness of about 50 μ. The plate is then ^{heated to about 100 °} C. for a period of about 1 hour. An O ^ layer of amorphous selenium is then evaporated onto the resin surface. The plate is electrostatically charged by means of a corona discharge device operating at a positive voltage of approximately 6000 volts. The plate is then exposed for approximately 1 second by projecting a black and white slide in an enlarger. The enlarger is equipped with an f / 4.3 lens and a tungsten light source that works at a color temperature of 2950 ° K. The amount of light incident on the plate is approximately 43 lux. The resulting electrostatic latent image is developed by cascading electroscopic marking particles across its surface according to the method described in US Pat. No. 2,618,551. The powder image obtained is electrostatically transferred to a paper receiving sheet by the method described in US Pat. No. 2,576,047. The image on the sheet is of good quality and corresponds to the projected image. The plate is then reinserted in the process described above until 500 copies have been made. The image on the 500th sheet has the same quality as the image produced on the first sheet and corresponds to the projected image.

Example 4

A coating solution is prepared by adding about 5 parts of an aromatic polyimide resin containing by reacting pyromellitic dianhydride with a diamine, in about 6 Parts of dimethylformamide are dissolved. About 0.1 part of metal-free phthalocyanine is added to this solution added in the "X" form. This mixture is then applied to an aluminum substrate up to one Stacked dry thickness of about 10μ. The resin is then for a period of cured for about 1 hour at about 200 ° C. A 3 ^ layer of amorphous selenium is then applied formed on the resin surface by vacuum evaporation. The plate is then loaded, irradiated and developed according to the method described in Example 3. This creates a good image that matches the corresponds to original picture. The plate can be cleaned in a simple manner using a rabbit fur. After 600 copies have been made, the copies are still of the same quality as they were first generated image.

Example5

A coating solution is made by adding approximately 1 part of a melamine / formaldehyde resin About 10 parts of butanol is dissolved in this solution become about 0.4 parts of the form of metal-free Phthalocyanine added. The mixture is then applied to an aluminum substrate up to a dry film thickness of approximately 30 μ. The resin is ^{cured by heating the plate to approximately 150 °} C. for a period of approximately 2 hours 4 μ thick layer of amorphous selenium is then applied to the hardened resin surface in a vacuum vapor-deposited. The plate is then loaded, irradiated and following that described in Example 3 Method developed. A picture with a good one is developed

ft? Get quality whatever the original picture The plate can be cleaned easily with a rayon brush. After creating The generated image still has the 450 copies

709524/327

equally good quality, as was noted in the first image produced.

Example 6

A coating solution is prepared by about 1 part! a urea / formaldehyde resin is dissolved in a mixture of about 5 parts of xylene and about 5 parts of butanol. About 0.15 part of the form of metal-free phthalocyanine is added to this solution. An aluminum substrate is coated with the mixture to a dry film thickness of approximately 15 μ. The plate is then heated to about 15O ⁰ C for a period from about 1 hour to cure the resin. Then an approximately 2μ thick layer of selenium is piled up. The plate is then loaded, irradiated and developed according to the method described in Example 3. As a result, an image that corresponds to the original image is obtained with good quality. After 900 copies are made, the image produced will be of the same quality as the first reproduced image.

Example 7

A coating solution is prepared by dissolving about 70 parts of an epoxy resin in about 80 parts of ethyl cellosolve, an ethylene glycol monoethyl ether. About 40 parts of a phenolic resin and about 9 parts of a urea / formaldehyde resin are added to this solution. The mixture is stirred to ensure complete dissolution. About 20 parts of the "X" form of metal-free phthalocyanine are added to this solution. An aluminum substrate is coated with this mixture to a dry film thickness of approximately 40 μ. The plate is then ^{heated to ~ 80 °} C. for a period of approximately 2 hours to harden the resins. A β-μ layer made of amorphous selenium is then evaporated onto the resin surface in a vacuum. The plate is then loaded, irradiated and developed according to the method described in Example 3. As a result, an image corresponding to the original image is obtained with a good quality on the plate. After 200 copies are made, the image produced will be of the same quality as the first reproduced image.

Example 8

A coating solution is prepared by dissolving about 2 parts of a vinyl carbazole polymer in about 10 parts of toluene. About 0.2 parts of the * · "X" form of metal-free phthalocyanine are added to this solution. An aluminum substrate is coated with this solution to a dry film thickness of about 11 μm. The plate is then heated to about 80 ^° C. for a period of 1 hour heated to ensure removal of the solvent. A 1.5μ thick layer of amorphous selenium is then applied over the resin surface by vacuum vapor deposition. The plate is then charged, irradiated and developed according to the method described in Example 3. A good image is obtained that corresponds to the original image on the plate After 950 copies have been made, the resulting image will be of the same quality as the first reproduced image.

Example 9

A coating solution is prepared by adding approximately 2 parts of a glycerol triester to 50% hydrogenated wood resin can be dissolved in approximately 10 parts of toluene. This solution will be approximate 0.25 part of a finely divided chlorinated copper phthalocyanine added. An aluminum substrate is made by floating with this mixture up to one

ίο dry thickness of about 45 μ coated. Then it will be a 5 μ thick layer of approximately 90% selenium and 10% Tellurium formed on the resin surface. This plate is then loaded, irradiated and after the in Example 3 described method developed. A picture with a good quality that matches the original picture is obtained. After 250 copies are made, the image produced will be the same Quality as the picture reproduced first.

Example 10

A coating solution is prepared by adding about 2 parts of a polycarbonate resin in about 10 parts of dioxane and about 10 parts of dichloromethane are dissolved. This solution will be about 0.3 parts of a finely divided, metal-free phthalocyanine * added in the α-form. An aluminum substrate is made through Float coated with this mixture to a dry thickness of approximately 9 μ. One about 20 μ thick layer of about 90% selenium and about 10% tellurium is then placed on the resin surface applied by the method described in US Pat. No. 2,745,327. This plate is then charged, irradiated and developed according to the method described in Example 3. This is a picture with an excellent quality, which corresponds to the original picture. After When producing 200 copies, the resulting image will be of the same quality as the first reproduced image.

Example 11

A tpoxy-phenol coating solution is used after the procedure described in Example 7 prepared. A brass foil with a thickness of 25 μίτι is with this solution to a dry thickness of approximately

14 ^ i ^ layers. The plate is then over a period of about 5 hours to partially cure the resin to about 40 ⁰ C heated inputs; about 2μ thick layer of about 17% arsenic and about 83% selenium is then formed over the resin surface by the method described in US Pat. No. 2,822,300 120 ⁰ C held. This record will

then charged, irradiated and according to the example The method described in 3 develops an image with a good quality similar to the original image corresponds to is obtained. After generation out of 1000 copies, the generated 3 image has the same

Quality like the BHd reproduced first.

The materials and conditions given in the above examples are merely exemplary in nature. Various other materials, such as those noted above

rials, and various other conditions are könneil also be used or applied, similar results are obtained. The selenium-containing layer and / or the phthalocyanine / blend agent

Resin layers can also be mixed with other materials to improve their properties, to sensitize or otherwise modify or to give them a synergistic effect. For example, electrical or spectral sensitizers can be added to each layer. the

The multilayer plate according to the invention can also be used in other fields in which photoreceptors with a wide spectral sensitivity are required, for example in a vidicon system.

Claims (5)

Patent claims: J. Electrophotographic recording material from an electrically conductive layer carrier, an intermediate layer with an insulating one Binder and a pigment, and a photoconductive layer containing a phthalocyanine as a pigment and contains a selenium-containing layer as the photoconductive layer, according to Patent 15 97 877 thereby characterized in that there is a 10 to 50, preferably 10 to 15 μm thick intermediate layer and a 0.5 to 5, preferably 1 to 3 μm thick contains selenium-containing layer 2. Recording material according to claim 1, characterized in that it is used as phthalocyanine the α-form, the X-form, preferably the polymorphic crystalline Χ form, or a mixture of both forms of metal-free phthalocyanine contains. 3. Recording material according to claim 1, characterized in that the intermediate layer consists of 0.5 to 15, preferably 1 to 10 parts by weight of binder per part by weight of phthalocyanine. 4. Recording material according to claim 1, characterized in that it is a binder Contains polycarbonate. 5. Recording material according to claim 1, characterized in that the selenium-containing Layer made of selenium or a mixture of selenium and arsenic.