DE2229992B2 - Electrophotographic recording material - Google Patents

Description

3 ^ ₄

will carry, after which a drying process at- methyl ethyl ketone was in an amount equal to that

»Afterwards dry in air and heat, half the amount of the mixture added to get the barrier layer. _a coating solution for the barrier layer

Since, furthermore, those obtained from a composition. The solution thus obtained was then applied to the made of nitrocellulose and polyvinylpyrrolidone 5 light-permeable conductive layer with a thickness of The built barrier has good flexibility, is applied at 3 to 4 microns (after drying) the preparation of the coating solution per se and dried to obtain the barrier layer. the Plasticizer necessary, the film formability of the resulting coating (barrier layer) was high but can be made even better by adding translucent, strong and flexible and adhered add 10 to 50% of a well-tolerated soft io to the conductive layer. After that, the machers, for example trichloroethyl phosphate, tri-barrier layer a photoconductive material made of poly-N-cresyl phosphate, chlorinated biphenyl and the like vinyl carbazole, crystal violet and benzene-chlorobenzene

The film of the resulting barrier layer is applied softly (1: 1) in an amount of 8 g / m ² and is strong and has sufficient flexibility. dried to a photosensitive layer

depending on the purpose of the barrier layer, 15 can be obtained. The resulting transparent recording pigments and other additives in the required material were subjected to a known electrophotographic amount of the coating solution to obtain the graphic imaging process, ie, a barrier layer was added. _it was charged, exposed, photographically reduced

The thickness of the barrier layer is suitably smaller and wet developed in order to obtain excellent positive images than about 10 microns, preferably 3 to 7 microns. When enlarging the positive images by meter. In particular, in a recording projector, it was found that the film free material for a copier obtained a good result even from the various commonly occurring when the thickness of the barrier layer was about electrostatic problems and was clear as well as 1 micrometer. If the thickness of the barrier layer provided sharply defined images. In contrast, when made larger than 10 micrometers, it has been found that electrophotographic sensitive whites are produced by discharge destruction to a greater extent when an ordinary wedge adversely affects. If the barrier layer is made of smaller photosensitive recording material without a barrier 10 micrometers thick, then the result is that layer was used,
practically no noticeable decrease in sensation

possibility, and if the barrier layer is larger than 3 micro- 30 Example 2

meter made, then discharge destruction can occur on a conductive pad made of a polyester film

and fatigue on repeated use (75 micrometers thick) that smudges a vapor-deposited aluminum of the recording material can be avoided. nium layer with a light transmission of 60%

The organic photoconductive layer is coated on the mixture obtained Barrier layer created according to conventional methods to prevent the 35 by mixing a 5% nitrocellulose solution, electrophotographic recording degree of nitration according to the invention 11.5 to 12.2% with a 10% material to receive. Polyvinylpyrrolidone solution in weight ratio

For the organic ^{fotoleitfäh:} 1, wherein the known organic Foto'eiter be used in both cases, the solvent: ge material can of Figure 1. Ethyl alcohol-methyl alcohol (7: 3) was, and specially preferred materials are organic, 40 adding methyl ethyl ketone and dimethyl polymer materials such as poly-N-vinylcarbazole, chloroformamide, each in an amount equal to a quarter of the poly-N-vinylcarbazole, brominated poly-N-vinyl of the weight of the above blend. The mixture of carbazole, cyanated poly-N-vinylcarbazole, poly- was applied after drying to obtain a 3 to 4 micrometer thick vinylacenaphthene and the like barrier layer. the

Chlorinated poly-N-vinylcarbazole can be obtained 45 resulting barrier layer showed excellent inheritance by chlorinating poly-N-vinylcarbazole shafts similar to Example 1. A solution with chlorine gas or with sulfuryl chloride or with 3 g of poly-N-vinylcarbazole, 0.1 g of N-vinylcarbazole, 0.2 g Polymerize a chlorinated vinyl carbazole. Be carbon · tetrabromide and 45 milliliters of a Lösteiger further details for the production of a solvent mixture of benzene and chlorobenzene (1: 1) to the German Offenlegungsschrift 2 035 679 ver 50 was irradiated with UV light for 20 minutes, im grasslands. in the dark for 6 hours at ambient temperature

The examples below are for extensions and applied to the barrier layer,
purposes, they are by no means in the The recording material showed as well as after

restrictive sense. Example 1 excellent transparent positive images,

". . ,. 55 that were free of white spots.

example 1

An aqueous solution of an agent for degrading egg spat

the resistance of poly- (N, N'-dimethyl-3,5-methy- A conductive support made from a polyester film

lenpiperidiniumchlorid was on a Polyäthylente- (75 micrometers thick) with a vapor-deposited aluminum

rephthalate film applied, which is an underlying 60 minium layer with a light transmission of 60%

Layer (75 micrometers thick) had, and was obtained with a mixture obtained in the following manner

a transparent conductive layer dried. Dirt solution coated to after drying

after a 10 percent by weight nitrocellulose barrier layer 4 to 5 micrometers thick was obtained:

Solution degree of nitration from 11.5 to 12.2% with a 15% nitrocellulose solution, degree of nitration

10% polyvinylpyrrolidone solution at a ratio of 11.5 to 12.2% in ethyl alcohol-methyl alcohol

ratio of 2: 8 (parts by weight) mixed. The lo- (7: 3) was in the ratio of 8: 2 parts by weight

The solvents in both of the above solutions are ethyl mixed with a 15% polyvinylpyrrolidone

alcohol-lvtethyl alcohol (7: 3). Solution in ethyl alcohol-methyl alcohol (7: 3); then

methyl ethyl ketone and dimethylformamide per charge image on an electrotatic image receiving in an amount equal to the fourth part of the weight of the material took place. When the image receiving material is added to the above mixture. As in Example 1 was developed in a liquid developer, the resulting barrier layer was transparent, strong, had excellent images, and had the effect of being flexible and adhered well to the vapor deposition. 5 Discharge destruction prevention was largely aluminum layer. A solution of the barrier layer was then better than with conventional recording media without the barrier layer. The lifespan was the following without chlorinated poly-N-vinyicarbazole and rhodamine B barrier layer about 100 uses, with barrier in benzene-chlorobenzene (1: 1) 5 to 6 g / rc ² thick about fifteen hundred uses, wear and dry to to obtain the photoconductive layer in Example 6.

The electrophotographic recording material A recording material which, as in Example 5

was made with a reduced original as in Example 1, was a conventional xerographic

exposed to obtain sharp positive images. The process repeatedly subjected, in the course of which a

Sensitivity was very good. After enlarging the 15 charge at -7.0 KV, an imagewise exposure

resulting positive images with the help of a projector with about 100 lux sec, a development with liquid-

one obtained projection images devoid of white spots, a transfer onto ordinary paper

uad of high fidelity. The photoconductive and a cleaning of the recording material static

Layer was strong, flexible and highly adhesive. found. Sensitivity was excellent and that

20 Effect of preventing discharge destruction

Example 4 _{through the} barrier was substantial. The life-barite paper that underwent conductivity treatment was the following

a mixed solution was applied - _{without a} barrier layer, used about 50 times,

wear, to obtain, after drying, a 15 to 20 micro _{mk Sperrsch} j _ch t about 700malige use, meter thick barrier layer. The mixture 25

solution was obtained by mixing a 10% Example 7 nitrocellulose solution, degree of nitration 11.5 to 12.2%

in ethyl alcohol-methyl alcohol (7: 3) in a mixture on an aluminum foil (31 micrometers thick) as a ratio of 2: 8 parts by weight with a 10 weight-conducting layer substrate was a solution mixture percent polyvinylpyrrolidone solution in ethyl 30 to obtain a barrier layer in a thickness of alcohol-methyl alcohol (7: 3), then still 1 to 2 micrometers applied after drying, methyl ethyl ketone in an amount equal to half the mixture solution was obtained by adding a mixture amount. 7 percent by weight nitrocellulose solution, Nitrie-Sodann was applied to the resulting barrier layer approx. 11.5 to 12.2% in a ratio of 2: 8. A mixture of poly-N-vinylcarbazole and crystal 35 parts by weight was mixed with a 10% polyviolet in Benzene-chlorobenzene (1: 1) in a starch vinylpyrrolidone solution, in both cases from 4 to 6 g / m ^{2 being} applied and dried. The solvent was ethyl alcohol-methyl alcohol (7: 3). The recording material was then added as usual, methyl ethyl ketone in an amount equal to half the mixture amount by electrophotographic imaging method. This loading, exposed and developed to obtain a clear visible 40 barrier had the same properties as the images free of white spots. according to example 5.

The barrier layer was then made with photosensitive

^{Example 5} Substance for obtaining an 8 micrometer thick light-coated onto an aluminum foil (31 micrometer thick) as a sensitive layer. The photosensitive support was coated with a mixed solution of 45% composed of 2 grams to obtain a barrier poly-N-vinylcarbazole 1 to 2 micrometers thick and 10 mg of crystal violet, as well as a layer after drying. The Mi- a coumarone resin as a plasticizer in 40 ml benzene schungslösung was obtained by adding a 10% nitro-chlorobenzene (1: 1). The resulting recording cellulose solution nitration degree 11.5 to 12.2% with material was repeated a process for 10% polyvinylpyrrolidone solution in a weight transfer of 5 ° of a charge image to an electrophotograph ratio of 1: 1 was mixed. The solvent for paper as in Example 5 subjected. The charge image transferred to both solutions was ethyl alcohol-methyl alcohol was then toner after (7: 3). Then methyl ethyl ketone and the magnetic brush method were developed. The prevention of methylformamide in an amount equal to the fourth charge destruction effect was pronounced, part by weight of the above mixture was added. The 55 and the fatigue were very small, this solution blocking layer obtained was trans- high, the life was the following parent, strong and flexible and adhered firmly to the _{no barrier about 9o-time} use, aluminum layer transformer The barrier layer was then _h barrier as 1200malige use , coated with a 9 micrometer thick photoconductive layer do. It contained 20 mg of rhodamine B and ^6o Example 8 diphenyl chloride as a plasticizer in 40 ml of benzene

Chlorobenzene (1: 1). For use as a recording A light-sensitive produced as in Example 7

The recording material for repeated use has become a common one

In electrophotography she was repeatedly subjected to an electro-xerographic generating process in

subjected to photographic imaging process, at ⁶ 5 the course of which a charge at -7.0 KV ₁ a

that a corona charge at -7.0 KV, imagewise image exposure at 100 lux seconds, a development

Exposure with a 500 W tungsten lamp using the cascade method, a transfer to ordinary

40 lux sec and a transfer of the resulting paper and a cleaning of the photosensitive

lichen recording material took place. It was found that the preventing effect of discharge destruction was excellent. The life span was as follows

without a barrier, used around 50 times,
with barrier layer about 700 uses.

Example 9

The support used in Example 5 was mixed with a solution to obtain a 1 to 2 micrometer A thick barrier layer is coated after drying. The mixed solution was obtained by adding a 12% nitrocellulose solution, degree of nitration 10.7 to 11.9% in ethyl alcohol-methyl alcohol (7: 3) in the ratio of 7: 3 parts by weight was mixed with a 10% polyvinylpyrrolidone solution in the same Solvent, in which case methyl ethyl ketone and DI cihylformamid each in an amount equal to that Quarters of the above mix weight were added. The resulting barrier was highly transparent, strong and flexible and adhered well to an aluminum substrate. On the barrier was applied a photoconductive layer 12 micrometers thick after drying. The composition was 0.5 mole (2 g) of chlorinated poly-N-vinyl carbazole 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 repeated an electrostatic transfer process subjected, meanwhile a charge at -7.0 KV, an image exposure at 10 lu ~, see and the charge image was transferred to an image receiving material. After developing the Image receiving material in liquid developer can be used to obtain a good toner image, with the preventive effect the discharge destruction was good. The life span was as follows

about 300 uses without a barrier layer,
with barrier layer about SOOO times used.

Example 10

A recording material as in Example 9 was repeated an electrophotographic process subjected, in the course of a charge at 7.5 KV, an imagewise exposure at about 20 lux sec, a development in the magnetic brush process, a transfer to normal paper and a Cleaning of the recording material took place. The resulting image on the copy was clear and one Discharge destruction was practically not observed. The life span was as follows

without a barrier, used around 200 times,
with barrier about 3000 uses.

Example 11

On a sandblasted aluminum foil (100 micrometers strong) as a conductive support, a mixed solution was applied to after drying a 1 to 2 micrometer thick barrier layer. The solvents were made by a 20% nitrocellulose solution, degree of nitration 11.5 to 12.2% in ethyl alcohol-methyl alcohol (7: 3) by weight 1: 1 was mixed with a 10% polyvinylpyrrolidone solution in the same solvent, then methyl ethyl ketone and dimethylformamide each in an amount equal to a quarter of the above Mixing weight was added. The resulting barrier layer was very strong and flexible as well firmly adhered to the base. The barrier layer was then covered with a photoconductive layer of 15 micrometers Thick coated after drying. The layer was composed of 2 g of poly-N-vinylcarbazole, 3.7 g, 2,4,5,7-tetranitrofluorenone and 0.5 g diphenyl chloride in 40 ml tetrahydrofuran.

The resulting recording material was repeated for an electrostatic transfer process 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 image receiving paper took place. The image receiving paper was then placed in a liquid electrophotographic developer developed. The discharge destruction preventing effect was remarkably improved. The lifespan is the following

^ao without a barrier layer, used around 250 times,
with barrier about 3000 uses.

Example 12

A solution mixture was applied to a paper treated for conductivity as a conductive layer support, to obtain a 1 to 2 micrometer thick barrier layer after drying. The reading mix was obtained by adding a 10% nitrocellulose solution

Degree of nitration 11.5 to 12.2% in an ethyl alcohol-methyl alcohol solvent mixture (7: 3) in a weight ratio of 3: 7 was mixed with one 10% polyvinylpyrrolidone solution in the same solvent, with methyl ethyl ketone in an amount equal was added to half the weight of the mixture. The resulting barrier had properties like that given in Example 5. A photosensitive substance of 0.5 mol (2 g) chlorinated poly-N-vinylcarbazole and 3.2 g of trinitrofluorenone and 0.5 g of diphenyl chloride as plasticizers in 40 ml of tetrahydrofuran applied to a layer thickness of 12 micrometers after drying to obtain.

The resulting recording material became

repeatedly subjected to an electrostatic transfer process, in the course of which a charging at -7.0 KV, an image exposure at about 5 lux sec and transfer to an electrostatic image receiving paper took place. The electrostatic image sensing waste paper was developed using the magnetic brush process, and good quality images were obtained. The discharge destruction preventing effect was also excellent. The life span was as follows

without a barrier, used around 200 times,
with barrier layer approx. 4000 times of use.

Example 13

A conductive layer support made of a polyester film (75 micrometers thick) and a vapor-deposited aluminum layer with a light transmission of 60% was applied to a solution mixture to obtain a 1 to 2 micrometers thick barrier layer after drying. The solution mixture was obtained by adding a 6% nitrocellulose solution, nitration degree 11.5 to 12.2% in a solvent mixture of ethyl alcohol-methyl alcohol (7: 3)
was mixed in a weight ratio of 1: 1 with a »

409 522/3!

55

10% polyvinylpyrrolidone solution in the same solvent, methyl ethyl ketone being added in an amount equal to a quarter of the above mixture weight became. The barrier layer had film properties similar to Example 5. Furthermore, the barrier layer was made coated with a photosensitive substance coated to a 10 micrometer thick photosensitive Keep layer after drying. The photosensitive substance composed from 2 g of poly-N-vinylcarbazole, 20 mg of rhodamine B and diphenyl chloride as plasticizer in 40 ml of benzene-chlorobenzene (1: 1).

The resulting light-sensitive material was subjected to electrostatic repetition Subject to transfer process, in the course of which a charge at -7.0 KV, an image exposure with about 50 lux sec and transfer to an electrostatic recording paper took place. The recording paper was developed in liquid developer. The discharge destruction preventing effect was considerable.

Example 14

A 10% solution of nitrocellulose, degree of nitration 11.5 to 12.7% in methyl ethyl ketone and methyl isobutyl ketone was mixed with a 10% solution of polyvinylpyrrolidone in isopropanol and methanol. The mixing ratio was 3: 7 parts by weight. Furthermore, 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 TiO _{2 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. On an aluminum foil laminated with polycarbonate as a support, the resulting solution for obtaining a white barrier layer having a thickness of 5 to 4 micrometers after drying was obtained. The resulting applied film was very adherent and had good coverage.

Then, a photosensitive substance was applied to the barrier layer in an amount of 5 to 6 g / per ^m2 after drying 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 and chlorinated paraffin in a mixed solvent of toluene and monochlorobenzene (I: 1). The resultant light-sensitive material was charged in a known manner and then placed in an ordinary camera to take a picture of the upper half of a human figure by the flashlight at a distance of 15 m. The recording material was removed from the camera after the end of the exposure in the dark and developed with a liquid developer in order to obtain an excellent positive reflection image.

Claims (1)

An electrophotographic recording material with Claim: a support and a photoconductive layer made of ZnO and synthetic resin binder as well as a barrier Electrophotographic recording material consisting of a layer between these two layers is known a layer support, a barrier layer and a 5 From the German Auslegeschrift 1 246 408 is also photoconductive layer with an organic photoconductor, an electrophotographic recording material, characterized, known that consists of a layer support, one or more the barrier layer made of nitrocellulose and polymer interlayers and a photoconductive one vinylpyrrolidone. Layer with an organic photoconductor. ίο By using complicated organic Foioleitem is a recording material with high photoconductivity with good chemical stability aimed at. The invention is based on the object of providing an electrophotographic recording material The invention relates to making an electrophotographic bar which is attacked by the corona discharge non-fish recording material from a layer support and shows only slight signs of fatigue even with repeated use of a barrier layer and a photoconductive layer,
with an organic photoconductor. This object is achieved according to the invention Numerous organic photoconductive materials are dissolved in that the barrier layer is made of nitrocellulose and Polyvinylpyrrolidone is made of high polymer or low molecular weight form. known. Examples are poly-N-vinylcarbazole, compared to the known recording material Brominated poly-N-vinyl carbazole, polyvinyl anthracene, with organic semiconductors is in the invention Oxadiazoles and acylhydrazones. If desired, between the support and the photoconductive A barrier layer is provided to maintain the electrophotographic marking, namely from nungsmaterials sensitizers the organic photo- a special material. The particular advantage is ladders are added. to see that both destruction as well as Organic photoconductive materials are non-limiting signs of fatigue lent their transparency, flexibility, surface smoothness any photoconductive substances are avoided, and selectivity of charge polarity of large 30. Furthermore, the barrier layer according to the invention enables Advantage. In particular, high polymer organics can produce an electrophotographic recording niche photoconductive «materials formed as films will. excellent film properties such as adhesion An electrophotographic recording material, like, flexibility, tensile strength and long-term stability which an organic photoconductive material has only 35 did. borrowed is applied to a conductive substrate. The proportions of the barrier layer are to be selected in such a way that For electrophotographic purposes, the specific volume resistivity is not a certain Particularly satisfactory, since it has mainly an electro-suitable value for the destruction of a discharge static problems occur. to be avoided completely and signs of fatigue In particular, the electrophotographic application of a repeatedly used recording material tends to avoid drawing material made of a customary organic, the barrier layer being built up by the photoconductors, often to discharge electrophotographic properties such as photosensitive breakthroughs after charging with the aid of corona not adversely affected,
discharge, and the developed image contains white There are numerous nitrocelluloses with different Places that reduce the image quality significantly. For 45 licheni degree of polymerization and various avoidance of this disadvantage, it was proposed to use degree of nitration. These nitrocelluloses can be used for a synthetic resin adhesive layer between the layer according to the invention,
made of photoconductive material and the substrate. The substrate can be used for the present to be provided. So far, however, numerous common substrates have not been used for art purposes that doesn't get the sensitivity 50 den like this one with electrophotographic! Recorder light-sensitive layer is reduced and removal material is used. Exemplary would have adequately prevented charge breakthroughs. Layer supports are metal plates, aluminum, copper In electrophotographic image forming processes and the like, paper, aluminum-coated paper, art in which the electrophotographic recording resin film with co-surfactant compounded is repeatedly used, there are numerous synthetic resin films which have a corternary drawback, particularly exhaustion, ammonium salt for maintaining conductivity such as decrease in charge, low levels of electricity, glass, paper and synthetic resin on which metal is evaporated, charge rise time, residual images, and metal oxide or a metal halide. Sensitivity reduction as well as destruction. In general, the specific sheet resistance is due to discharge. 60 expediently below 10 ⁹ ohms, preferably below There has been no lack of research, an electro- 10 ^B Ohm. Photographic recording material with an organic The barrier layer is on the support so niche photoconductor formed in an electrophotographic that a solution of the substrate material, Apply process in which the recording, for example nitrocellulose in a suitable material repeated when charging, imagewise 65 solvent in a ratio of 2: 8 to 8: 2 Ge exposure, Weight image development and image transfer, using viscosity for brushability will. These investigations were previously no speed suitable values set on the shift success decided. carrier applied according to the usual coating methods.