DE2229992A1 - Electrophotographic photoconductive recording material - Google Patents

Description

Canon K. K. Canon Case 295

Tokyo Japan

Electrophotographic photovoltaic recording material

The invention relates to an electrophotographic photoconductive one Recording material comprising an organic photoconductive material.

Numerous organic photoconductive materials in high polymer or low molecular weight form are known. examples for this are Poly-N-vinylcarbazole., Brominated poly-N-vinylcarbazole, polyvinylanthracene, Oxadiazoles and acylhydrazones. If desired, it can be used to obtain the electrophotographic photoconductive recording material Sensitizers are added to the organic photoconductors.

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Organic photoconductive materials are in terms of their transparency, Flexibility, surface smoothness and selectivity of charge polarity of great advantage. In particular, high polymer organic photoconductive materials can be formed as films.

A photoconductive recording material in which an organic photoconductive material applied only to a conductive layer support is not for electrophotographic purposes particularly satisfactory, mainly because of electrostatic problems.

In particular, an electrophotographic photosensitive material tends to which is made up of a conventional organic photoconductor, often leads to discharge breakdowns after charging With the help of a corona discharge device, and the developed image contains white spots which greatly degrade the image quality. To avoid this disadvantage has been proposed in a synthetic resin adhesive layer to be provided between the layer of organic photoconductive material and the substrate, but it has not yet been done Resin adhesive layer obtained, which does not reduce the sensitivity of the light-sensitive layer and adequately prevented discharge breakthroughs.

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In electrographic imaging processes in which the ιοί ole itfätiige recording material is used repeatedly, there are numerous disadvantages, in particular phenomena of exhaustion such as diminution the amount of charge, low charge rise time, remaining images and sensitivity reduction as well as Destruction by discharge.

There has been no lack of research into a photosensitive recording material with an organic photoconductor in an electrophotographic To employ a process in which the photosensitive material is repeatedly image-wise upon charging Exposure, image development and image transfer. These investigations have so far been unsuccessful.

A photographic recording material with a layer support and a photoconductive layer made of ZnO and synthetic resin binder as well as a barrier between these two layers is known. However, a photosensitive material with a layer support and an organic photoconductive material as well as a barrier layer arranged between them have not yet been used, because practically effective barrier materials so far have not been found.

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Accordingly, it is an object of the invention to provide an electrophotographic photosensitive recording material, because it is free from destruction by discharge and significantly less fatigue than when used repeatedly shows so far.

With the present invention, special barrier materials have been found that can be used to both damage Discharge as well as fatigue one for repeated use in electrophotographic imaging processes provided photosensitive recording material can be avoided.

Accordingly, the electrophotographic photosensitive material is according to the invention characterized by a layer support, a barrier layer applied thereon, the is composed of nitrocellulose and polyvinylpyrrolidone, and an organic photovoltaic layer on the barrier layer.

The invention is described in detail below on the basis of various exemplary embodiments.

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The barrier layers used according to the invention are to be selected in such a way that the specific volume resistance has a certain suitable one Worth to completely avoid a discharge destruction and fatigue of a used repeatedly To avoid photosensitive recording material, the barrier layer otherwise the electrophotographic properties such as photosensitivity not adversely affected.

Barrier materials that meet these requirements are blends made of nitrocellulose and polyvinylpyrrolidone.

There are numerous nitrocelluloses with different degrees of polymerization and different degrees of nitration. These nitrocelluloses can be used for the purposes of the invention will.

The barrier layer between an organic photoconductive layer and the support serves to prevent the resultant photosensitive material from being destroyed by discharge and to avoid fatigue of the photosensitive! Recording material when it is used repeatedly. In addition, such a barrier allows

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the preparation of an electrophotographic photosensitive recording material having an electrophotosensitive layer with excellent film properties such as adhesiveness, flexibility, tensile strength and long-term stability.

Numerous conventional film carriers, such as those in the case of electrophotographic ones, can be used as the carrier for the present purposes Find light-sensitive recording material use. Exemplary layers are metal plates, aluminum, Copper and the like, paper, aluminum-coated paper, synthetic resin film with added surface active agents, synthetic resin films, that are treated with a corternary ammonium salt to maintain conductivity, that, paper and synthetic resin, on that Metal, metal oxide or a metal halide is evaporated. In general, the sheet resistivity is appropriate

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below 10 ohms, preferably below 10 ohms.

The barrier layer is formed on the substrate in such a way that a solution of the substrate material, for example nitrocellulose in a suitable solvent in a ratio of 2: 8 to 8: 2 parts by weight, the viscosity being

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If suitable values are set, refer to the substrate usual coating methods is applied, after which a drying process, for example drying in air and heat, follows in order to obtain the barrier layer.

Furthermore, the barrier layer, which is made up of a composition of nitrocellulose and polyvinylpyrrolidone, is a good one Has flexibility is in the manufacture of the coating solution No plasticizer in itself necessary, but the film can be made even better by adding 10 to 50% a well-tolerated plasticizer, for example trichloroethyl phosphate, tricresyl phosphate, chlorinated biphenyl and the like.

The film of the resulting barrier layer is soft and strong, and has sufficient flexibility.

Depending on the purpose of the barrier layer, pigments and other additives can be added to the coating solution in the required amount can be added to maintain the barrier layer.

The thickness of the barrier layer is advantageously less than about 10 micrometers, preferably 3 to 7 micrometers. In particular, was

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in a light-sensitive material for a copier, a good result can be obtained even if the The thickness of the barrier layer is approximately 1 micrometer. If the thickness of the barrier layer is made larger than Io micrometers, so the electrophotographic sensitivity is found to be adversely affected. Will the barrier layer be smaller than If made 10 micrometers thick, there is practically no noticeable decrease in sensitivity; and becomes the barrier Larger than 3 micrometers, then repeated use can cause damage to the discharge and signs of fatigue of the photosensitive recording material can be avoided.

The organic photoconductive layer is produced on the barrier layer by conventional methods in order to achieve the electrophotographic according to the invention To obtain recording material.

The known organic photoconductors can be used for the organic photoconductive material. Specially preferred materials are organic, polymeric materials such as Pc ^ r-N-Vinylcarbazole, chlorinated poly-N-vinylcarbazole, brominated poly-N-vinylcarbazole, cyanated poly-N-vinylcarbazole, polyvinylacenaphthene and the like.

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Chlorinated poly-N-vinylcarbazole can be obtained by chlorination of poly-N-vinylcarbazole with chlorine gas or with Sulfuryl chloride or by polymerizing a chlorinated vinyl carbazole. For more details on how to make it be on the DT-OS 2. o35. 679 referenced.

The following examples are given for expansion purposes, they are by no means to be construed in a limiting sense.

Example I.

An aqueous solution of a resistance reducing agent of poly- (N, N'-dimethyl-3, 5 -methylene piperidinium chloride applied to a polyethylene terephthalate film, which had an underlying layer (75 micrometers thick), and for Dried to obtain a transparent conductive layer. Thereafter, an Io weight percent nitrocellulose solution, the trade name RS-2 from Daiseru, degree of nitration of 11, 5 12, 2% with a lo% polyvinylpyrrolidone solution (the trade name PBP-K90 from GAF Co.) at a ratio of 2: 8 (weight line) mixed. The solvents in both of the above solutions are ethyl alcohol-methyl alcohol (7: 3).

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Methyl ethyl ketone was used in an amount equal to half the mixture amount added to the mixture to obtain a coating solution for the barrier layer. The solution thus obtained was then applied to the translucent conductive layer applied to a thickness of 3 to 4 microns (after drying) and dried around the barrier layer to obtain. The resulting coating (barrier layer) was highly translucent, strong and flexible and adhered to the conductive layer. Thereafter, a photoconductive material made of poly-N-vinylcarbazole, crystal violet and was applied to the barrier layer Benzene-chlorobenzene (1: 1) was applied in an amount of 8 g / m 2 and dried to obtain a photosensitive layer. The resulting transparent recording material was subjected to a known electrophotographic image forming process, i.e. it was charged, exposed, photographically reduced and wet designed to get excellent fbsitive images. When enlarged The positive images through a projector were found to be free from the various commonly occurring electrostatic problems and produced clear and sharply defined images. In contrast to this, white spots generated by discharge destruction were exhibited to a greater extent when a Usual light-sensitive recording material., without blocking

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- 11 shift was used.

Example II

A mixture was applied to a conductive base made of a polyester film (75 micrometers thick), which had a vapor-deposited aluminum layer with a light transmission of 60%, which was obtained by mixing a 5% strength nitrozene /ulose solution (the trade name RS 20 from Daiseru, degree of nitration 11.5 to 12 , 2%) with a 10% polyvinylpyrrolidone solution (the trade name PBP-K90 from GAF Co.) in a weight ratio of 1: 1, the solvent being ethyl alcohol-methyl alcohol (7: 3) in both cases, and by adding of methyl ethyl ketone and dimethylformamide, each in an amount equal to a quarter of the weight of the above mixture. The mixture was applied after drying to obtain a 3 to 4 micrometer thick barrier layer. The resulting barrier layer showed excellent properties similar to those in Example I. A solution of 3 gram poly-N-vinylcarbazole, 0.1 gram N-vinylcarbazole, 0.2 gram carbon tetrabromide and ^: 45 milliliters of a solvent mixture of benzene and chlorobenzene (1: 1) was irradiated with UV light for 20 minutes, stored in the dark for 6 hours at ambient temperature and applied to the barrier layer.

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The resulting transparent organic photoconductive layer became Treated as in Example I to make excellent transparency Obtain positive images free of white spots.

Example HI

A conductive support made from a polyester film (75 microns thick) with a vapor-deposited aluminum layer of a light permeability of 60% was coated with a mixture solution obtained in the following manner to be 4 to 5 micrometers after drying To obtain a thick barrier layer: a 15% nitrocellulose solution (the trade name RS 1/2 from Daiseru, degree of nitration from 11.5 to 12.2%) in ethyl alcohol-methyl alcohol (7: 3) was in the ratio of 8: 2 parts by weight mixed with a 15% polyvinylpyrrolidone solution (the tradename PBP-K60 ex GAF Co.) in ethyl alcohol-methyl alcohol (7: 3); then were methyl ethyl ketone and dimethylformamide each in an amount equal to the fourth part of the Weight of the above mixture added. As in Example I, the resulting barrier layer was transparent, strong, flexible, and adherent good on the vapor-deposited aluminum layer.

Photosensitive material was then made up on top of the barrier layer

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from a solution of chlorinated poly-N-vinylcarbazole and Rho-

2 damin B in benzene-chlorobenzene (1: 1) was applied 5-6 g / m thick and dried to obtain the light-sensitive layer.

The resulting photosensitive film was exposed with a reduced original as in Example I to obtain sharp positive images. The sensitivity was very good. After enlarging the resulting positive images with the aid of a projector, projection images were obtained free of white spots and high fidelity. The photoconductive layer was strong, flexible and highly adhesive.

Example IV

A mixture solution was applied to baryta paper which had been subjected to a conductive treatment to obtain a 15 to 20 micrometer thick barrier layer after drying. The mixture solution was obtained by mixing a 10% nitrocellulose solution (the trade name RS-I from Dais e ru, nitration gr ad 11.5-12.2%) in ethyl alcohol-methyl alcohol (7: 3) in a ratio of 2: 8 Weight steep with a 10 weight percent polyvinylpyrrolidone solution (the trade name PBP-K90 from GAl ' ¹ Co.) in ethyl alcohol-methyl alcohol (7: 3), then still

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Methyl ethyl ketone in an amount equal to half the mixture amount was added.

It was then applied to the resulting barrier layer as a photosensitive layer Material a mixture of poly-N-vinylcarbazole and crystal violet

in benzene-chlorobenzene (1: 1) applied in a strength of 4-6 g / m and dried.

The resulting light-sensitive material was after conventional electrophotographic imaging method charged, exposed and designed to provide clear visible images free of white spots to obtain.

Example V

A mixture was applied to an aluminum foil (31 micrometers thick) as a conductive layer support in order to obtain a 1-2 micrometer thick barrier layer after drying. The mixture solution was obtained by mixing a lo% nitrocellulose solution (RS from Daiseru, degree of nitration 11, 5-12, 2%) with a lo% polyvinylpyrrolidone solution (PBP-K90, GAF Co.) in a weight ratio of 1: 1 . The solvent for both solutions was ethyl alcohol

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Methyl alcohol (7: 3). Then there were methyl ethyl ketone and dimethylformamide each added in an amount equal to the fourth part by weight of the above mixture. The barrier layer obtained with this solution was highly transparent, strong and flexible, and adhered firmly to the aluminum substrate. The barrier was then using a photosensitive material to obtain a 9 micrometer thick photosensitive layer. The light sensitive Material was composed of 2 g, 20 mg rhodamine B and diphnyl chloride (Trade name Kanechlor by Kanegafuchi Kagaku Co.) as a plasticizer in 40 ml of benzene-chlorobenzene (1: 1). For use as a photosensitive material for repeated use in electrophotography, the resulting lidite-sensitive Plate repeatedly subjected to an electrophotographic imaging process in which corona charging at -7, OKV, imagewise exposure with a 500 W tungsten lamp at 40 lux. sec. and a transfer of the resulting charge image to an electrotatic image-receiving material took place. When the image receiving material was developed in a liquid developer was obtained excellent pictures, and the effect of preventing discharge destruction was far better than conventional recording media without a barrier layer. The life was as follows

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without a barrier approximately 100 uses with a barrier approximately fifteen hundred uses.

Example VI

A photosensitive recording material, as according to the example V was produced, was repeatedly subjected to a conventional zerographic process, in the course of which a charge at -7.0 KV, an imagewise exposure of about 100 lux. sec, a development with liquid developer, a transfer to ordinary paper and cleaning of the photosensitive recording material took place. The sensitivity was excellent and the effect of preventing the discharge destruction by the barrier layer was considerable. The life was as follows

without barrier about 50 uses with barrier about 700 uses.

Example VII

On an aluminum foil (31 micrometers thick) as a conductive layer support a mixed solution was applied to obtain a barrier layer 1 to 2 micrometers thick after drying.

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brings. The mixture solution was obtained by adding a 7 percent by weight Nitrocellulose solution (RS40, Daiseru, degree of nitration 11, 5 to 12, 2%) in a ratio of 2: 8 parts by weight was mixed with a 10% polyvinylpyrrolidone solution (PBP-K30, GAP Co.) in both cases the solvent Ethyl alcohol-methyl alcohol (7: 3). Then was methyl ethyl ketone added in an amount equal to half the mixture amount. This barrier layer had the same properties as the ".nach Example V.

The barrier layer was then coated with photosensitive substance to give an 8 micrometer thick photosensitive layer. The photosensitive substance was composed of 2 grams of poly-N-vinylcarbazole and 10 mg. Crystal Violet and Coumarone RS 1/2 (trade name, supplied by Fuji Seitetsu) as a plasticizer in 40 ml. Benz oil-chlorine top oil (1: 1). The resulting photosensitive material was repeated a process for transferring a charge image on an electrophotographic paper as in Example V. The transferred charge image was then developed with toner using the magnetic brush method. The prevention effect cargo destruction was pronounced, and the fatigue *

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apparitions were very small. The life was as follows

without barrier about 90 uses with barrier about 1200 uses.

Example VIII

A photosensitive recording material prepared as in Example VII was subjected to a conventional xerographic generation process in the course of which a charge at -7.0 KV, an image exposure with 100 lux seconds, a development in the cascade process, a transfer to ordinary Paper and cleaning of the photosensitive material took place. It was found that the preventive effect a discharge destruction was excellent. The life was as follows

without barrier about 50 uses with barrier about 700 uses.

Example IX

The support used in Example V was mixed with a solution «-, mixture to obtain a 1 to 2 micrometer thick barrier layer

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coated after drying. The solution mixture was obtained by mixing a 12% nitrocellulose solution (SS l / 4a, Daiseru, degree of nitration 10, 7 - 11, 9%) in ethyl alcohol-methyl alcohol (7: 3) in a ratio of 7: 3 parts by weight with a 10% Polyvinylpyrrolidone solution in the same solvent, in which case methyl ethyl ketone and dimethylformamide were each added in an amount equal to a quarter of the above mixture weight. The resulting barrier layer was highly transparent, strong and flexible, and adhered well to an aluminum support. Photosensitive substance was applied to the barrier layer to obtain a photosensitive layer 12 micrometers thick after drying. The composition of the photosensitive substance was 0.5 mol (2 g) of chlorinated poly-N-vinylcarbazole and 3.2 g and 2, 4, 7-trinitrofluorenone and diphenyl chloride as a plasticizer in 40 ml of tetrahydrofuran. This electrophotographic recording material was repeatedly subjected to an electrostatic transfer process in the course of which it was charged at -7.0 KV, and an image was exposed at 10 lux. sec. and a transfer of the charge image to electrostatic recording paper took place. After the electrostatic recording paper was developed by the physics developer, a good resultant image was obtained, and the discharge destruction preventing effect was good. The life was as follows

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without barrier about 300 uses with barrier about 5000 uses

Example X

A photosensitive recording material as in Example 9 was repeatedly subjected to a xerography process, in the course of which a charge at 7.5 KV and an imagewise exposure at about 20 lux. sec, a development in magnetic brush processes, a transfer to normal paper and a cleaning of the recording material took place. The resulting image on the copy was clear, and discharge deterioration was practically not observed. The life was as follows
without barrier about 200 uses with barrier about 3000 uses

Example XI

On a sandblasted aluminum foil (100: micrometers thick) as On the conductive base, a mixed solution was applied to form a 1 to 2 micrometer thick barrier after drying obtain. The solvents were prepared by adding a 20% nitrocellulose solution (RS-l / 4, Daiseru, degree of nitration 11, 5-12.2%) in

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Ethyl alcohol-methyl alcohol (7: 3) mixed in a weight ratio of 1: 1 was with a 10% polyvinylpyrrolidone solution (PBP-K90, GAF Co.) in the same solvent, then methyl ethyl ketone and dimethylformamide was added in an amount equal to a quarter of the above mixture weight. The resulting The barrier layer was very strong and flexible and adhered firmly to the base. The barrier layer was then covered with photosensitive substance coated to give a photosensitive layer 15 micrometers thick after drying. The substance was composed from 2g poly-N-vinylcarbazole, 3, 7g, 2,4, 5, 7-tetranitrofluorenone and 0.5g diphenyl chloride (trade name Kanechlor) in 40 ml of tetrahydrofuran.

The resulting photosensitive recording material became a Electrostatic transfer process repeatedly subjected, in the course of which a charge at -7.0 KV, an imagewise exposure at about 15 lux. sec. and a transfer to an electrostatic Recording paper took place. The electrostatic recording paper was then developed into liquid developer. The ver

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Discharge destruction prevention effect was remarkably improved. The lifespan is the following approximately 250 uses without a barrier layer with barrier layer about 3000 uses

Example XII

A paper treated for conductivity as a conductive support a mixed solution was applied to provide a 1 to 2 micrometer thick barrier layer after drying. The solution mixture was obtained by adding a 10% nitrocellulose solution (RS 2, Daiseru, degree of nitration 11, 5-12, 2%) in an ethyl alcohol-methyl alcohol solvent mixture (7: 3) in a weight ratio of 3: 7 was mixed with a 10% polyniylpyrrolidone solution (PBP-K60, GAF Co.) in the same solvent, with methyl ethyl ketone in was added in an amount equal to half the weight of the mixture. The resulting barrier had properties like those in Example 5 specified. A photosensitive substance from 0.5 mol. (2 g) chlorinated poly-N-vinyl carbazole and 3, 2 g of trinitrofluorenone and 0.5 g of diphenyl chloride as a plasticizer in 40 ml of tetrahydrofuran applied to after drying to obtain a layer thickness of 12 micrometers.

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The resulting light-sensitive material was repeatedly subjected to an electrostatic transfer process, in the course of this a charge at -7.0 KV, an image exposure at about 51ux. lake. and a transfer to an electrostatic one Recording paper took place. The electrostatic recording paper was developed using the magnetic brush method, and was obtained Good quality images. The discharge destruction preventing effect was also excellent. The lifespan was the following about 200 uses without a barrier layer with a barrier layer about 4000 times of use

Example XIII

A conductive backing made from polyester film (75 microns thick) and a vapor-deposited aluminum layer with a 60% light transmission, a mixed solution was applied to form a 1 to 2 micrometer thick barrier layer after drying to obtain. The solution mixture was obtained by adding a 6% nitrocellulose solution (RS -20, Daiseru, degree of nitration 11.5-12.2%) in a solvent mixture of ethyl alcohol-methyl alcohol (7: 3) was mixed in a weight ratio of 1: 1 with a 10% polyvinylpyrrolidone Solution (PBP-K30, GAF Co.) in the same solvent, with methyl ethyl ketone in an amount equal to the quarter

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of the above mix weight was added. The barrier layer had film properties similar to Example 5. Furthermore The barrier layer was coated with a photosensitive substance coated to make a 10 micrometer thick photosensitive Keep layer after drying. The photosensitive substance was composed of 2 g of poly-N-vinylcarbazole, 20 mg Rhodamine B and diphenyl chloride as plasticizers in 40 ml of benzene-chlorobenzene (1: 1).

The resulting light-sensitive material was repeatedly subjected to an electrostatic transfer process, in the course of this a charge at -7, OKV, an image exposure at about 50 lux. sec. and a transfer to an electrostatic Recording paper took place. The recording paper was developed in liquid developer. The Discharge Destruction Ve the hindrance effect was considerable. ,%

Example X IV

A 10% solution of nitrocellulose (RS-2, Daiseru, degree of nitration 11.5-12.7%) in methyl ethyl ketone and methyl isobutyl ketone were mixed with a 10% solution of polyvinylpyrrolidone (PBP-K90, GAF Co.) in isopropanol and methanol. The mixing ratio

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was 3: 7 parts by weight. Further, a mixed solvent of methyl ethyl ketone and dimethylformamide was added in an amount equal to half the weight of the above mixture to obtain a transparent, low viscosity liquid as a solution for the barrier layer. Then TiOg was added to this liquid in the ratio of solid resin to TiO ₂ equal to 6: 1. The whole was then ball milled for two days and filtered to obtain the coating solution. The resulting solution for obtaining a white barrier layer with a thickness of 5 to 4 micrometers was obtained after drying on an aluminum foil laminated with polycarbonate as a support. The resulting applied film was very strongly adherent and had good coverage.

A photosensitive substance was then applied to the barrier layer

an amount of S to 6g / per m after drying applied to to obtain a photosensitive recording material. The photosensitive substance used was composed of poly-N-vinylcarbazole a trimethine dye and a plasticizer such as Coumarone RS 1/2 Coumarone LCE and chlorinated paraffin in Solvent mixture of toluene and monochlorobenzene (lsi).

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The resulting light-sensitive material was subjected to charging in a known manner and then converted into a usual camera spent around taking a picture of the upper half of a human figure in the flash at a distance of 15 m do. The recording material was removed from the camera according to Be = At the end of the picture taken in the dark and developed with a liquid developer to produce an excellent positive reflection image to obtain,

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Claims (1)

PATENT CLAIM Electrophotographic photosensitive recording material characterized by a layer support, a barrier layer applied thereon, made of nitrocellulose and polyvinylpyrrolidone composed, and an organic photoconductive layer on the barrier layer. 209853/1068