DE1058836B - Material for electrophotographic reproduction - Google Patents

Description

Among the modern duplicating processes, the electrophotographic process, also known as xerography, is gaining increasing practical importance. This drying process is of particular interest in some areas, for example for office copying, and consists in applying an electrostatic charge to a material consisting of an electrically conductive base and a photoconductive iso-layer adhering to it, thereby imparting light-sensitivity to the insulating layer . Such photosensitive material is useful for the formation of images by electrophotographic means. It is exposed under an original and thereby the electrostatic charge of the layer is dispersed at the points where it is struck by light. The thus obtained invisible electrostatic image is made by powdering with finely divided colored resin visible ( "developed" ·) and subsequently characterized indelible and resistant made ( "fixed" -), that heating the substrate, Toggle whereby the resin is zo melted, or reapplied to an electric field '.

It is known that the photoconductive iso layers required for the process described above using selenium or sulfur, also zinc oxide or organic substances such as To produce anthracene or anthraquinone. The photoconductive ones have also been considered Produce insulating layers by adding photoconductive substances with binders in Dispersed solvents and such dispersions on electrically conductive substrates, primarily on metal foils, applies and dries. -The photoelectrically sensitizable material thus obtainable, however, is not yet sufficient for the very varied demands, which modern reproduction material with regard to possible uses, Safety in use, ease of use and, last but not least, sensitivity to light and durability has to suffice.

It has now been found that photoelectrically sensitizable layers with unexpected success and surprising Versatile utility can be produced by using 2,5-bis- (p-aminophenyl) -l, 3,4-oxdiazoles as photoconductive substances used.

As examples of the 1,3,4-oxdiazole bodies to be used according to the invention for the production of the electrophotographic layers, the compounds given are those represented by the general formula
nn

.R ₁

; n—

> —C,

■ -K

v ₂ O '^ R ₃

correspond, where R ₁ for hydrogen atoms, alkyl, material for electrophotographic
reproduction

Applicant:

Kalle & Co. Aktiengesellschaft,
Wiesbaden-Biebrich, Rheinstr. 25th

Dr. Wilhelm Neugebauer,
Dr. Martha Tomanek _r née Kunitzer,
and Dr.- Hans Behmenburg, Wiesbaden-Biebrich,
have been named as inventors

Acyl or cycloalkyl groups and R _{2 represents} hydrogen atoms, or of the general formula

n-

-n:

where R ₃ denotes alkyl or acyl and R ₄ denotes alkyl groups, or of the general formula

, n-

n Il

-n

II

X-

-n:

, Alkyl

'Alkyl

wherein R _{5 represents} hydrogen atoms or alkyl groups.

These general formulas include e.g. B. 2, S-bis [4'-aminophenyl- (l ')] - l, 3,4-oxdiazole, the 2,5-bis- [4'-monoalkylaminophenyl- (l ')] - 1,3,4-oxdiazoles, the 2,5-bis- [4'-dialkylaminophenyl - (1 ')] -1,3,4-oxdiazoles, the 2,5-bis [4'-monoacylaminophenyl- (l')] - 1,3,4-oxdiazoles, to name just a few of the most important.

The preparation of the 2,5-bis- (p-aminophenyl) -1,3,4-Öxdiazoleverbindungen to be used according to the invention takes place in a manner known per se from 2 mol of a corresponding p-aminobenzolecarboxylic acid and 1 mole of a hydrazine salt in the presence of dehydrating agents such as oleum or polyphosphoric acid.

The 2,5-bis- (p-aminophenyl) -l, 3,4-oxdiazole bodies have very good photoconductivity and are suitable particularly good for producing homogeneous layers that

- 909 529/407

can be stored for a limited time. The compounds are dried to form a fluid, photoconductive

arbless and fluoresce in the daylight or in the ultra-layer on the electroconductive base,

/ iolette light. The layers are inherently insensitive. To-

The photoconductive IsoUerschichten to manufacture, however, the one an electrostatic potential expended to advantageous solutions of the Inventions 5 has brought, for example by a corona discharge,

1,3,4-oxdiazoles that are to be used in organic compounds, the layer is light-sensitive and can be

Solvents such as B. Benzene, acetone, methylene wave UV light from 3600 to 4000 Ä to ebctro-

diloride, glycol monomethyl ether, and others, or used in photographic imaging. With

Cniches of several 1,3,4-oxdiazole bodies of this one high-pressure mercury lamp can be placed under one Line. Mixtures of solvents can also be used to produce good images with a very short observation time

use. can be obtained.

For the production of the photoconductive insulating materials ^{In the} visible range of the light spectrum are the

it can, as has also been found, be advantageous to apply layers according to the invention even after

the 2,5-bis- (p-aininophenyl) -l, 3,4-oxdiazoles together are still not very sensitive. How further found

to use with organic KoUoideri. As such ¹ S can be added by adding SensibiUsatorert to the

The natural and artificial photoconductive layers should be mentioned as their spectral sensitivity

borrowed resins, for example balsam resins, with Kolo- but brought into the visible area of the spectrum

phonium modified phenolic resins and other resins are used. That to be added to the photoconductive substance

with a decisive proportion of rosin, coumarone resins, amount of SensibiUsator is 1 to 3%. It is suitable, säkh

ond, indene resins and those under the collective term ²⁰ especially dyes, for their identification too

^ LackkunSÖmfze "falling" substances, for which the number is given after, under which they are in the "color

the substance tables published by Saeebtling-Zebrowski «by Schultz (7th edition, first volume,

Plastic pocket book (11, edition, 1955, p. 212ff.) Tough ¹⁹ 31) are listed. As, effective sensitizers

Ien modified natural substances, such as CeUuloseether; Poly ^sweet i ^s, for example: triarylmethane ,,

merisate, such as the polyvinyl chlorides, polyvinyl acetate ^ ² 5 such as BriUantgrün (No. 760>. S · .. 3 * 4), Victoria blue Bi

Polyvinyl acetals, polyvinyl alcohols, polyvinyl ethers, (No. 822, p. 347), methyl violet (No. 783, p. 327), crystal ·

Polyacrylic and polymethacrylic esters, also polystyrene violet (No. 785, p. 329), ^{acid violet 6B (No. 831 ,,}

and isobutylene; Polycondensates, e.g. B. Polyester, namely p. 351); Xanthene dyes, namely rhodamines, such as

Uch phthalate resins, alkyd resins, maleinate resins, maleic rhodamine B (No. 864, p. 365) ,. Rhodamine 6G (No. 866 ,.

Resin and rosin mixed esters of higher alcohols, phenol 3o p. 366), Rhodamine G extra (No. 865, p. 366), sulfo-

Formaldehyde resins, especially rosin-modified rhodamine B (No. 863, p. 364) and real acid eosin G.

Phenol-formaldehyde condensates, urea form (No. 870, p. 368) and phthaleins, such as Eosin S (No. 883;

aldehyde resins, melamine-formaldehyde condensates. Alde- p. 375), eosin A (No. 881, p. 374), erythrosine (No. 886,

bydharze, ketone resins (of which especially those under p. 376), phloxin (No. 890, p. 378) ,. Rose bengal (No. 889,

the designation AW2 resins commercially available 35 p.378) and fluorescein (No. 880, S; 3E3); Thiazine dye

Products are to be emphasized), xylene-formaldehyde substances such as methylene blue (No. 1038, p. 449); Acridine dye

Resins and polyamides; Polyadducts, for example substances such as acridine yellow (No. 901, S, 383), acndino orange

Polyurethanes. (No. 908, p. 387) and trypaflavin (No. 906, p. 386);

If one uses the 2,5-bis- (p-aminophenyl) -l, 3,4-ox-quinone uncoloured substances, such as pinacyanol (No. 924, p. 396) and

diazoles in a mixture with organic KoUoiden, so · 40 Kryptocyanin (No. 927, p. 397); Quinone dyes and

the proportions between resin and ketone dyes, such as alizarin (No. 11.41 ,, p. 499), AUzarin-

photoconductive substance vary within wide limits .. red S (No. 1145, p. 502) and quinizarine (No. 1148, p. 504);

The use of mixtures of approximately the same cyanine dyes, e.g. B. the dye according to the

Sharing resin and oxdiazole has proven to be a beneficial formula

proven. If one uses such mixtures of approximately * 5 g. ^^

equal parts of resin and O-xdiazole, then give ² - I ²

their solutions in most cases when drying ¹ '

transparent, colorless layers that form as solid solutions H ₂ C ^ C = CH CH = CH -C _v ^ H ₂

be considered. ^ 'j ^

The documents, 5 »/ ⁿ ^, serve as electroconductive carriers

which meet the requirements of xerography, for example CH ₃ H _s C SO ₄ -CH ₃₅ metal or glass plates, paper or plates or

FoUen from electrically conductive resins or plastic The production of the images on electrophotographic resins, so-called plastics. If you use ways it happens like this: After charging. Paper as a base for the photoconductive layer, so 55 the photoconductive layer, for example by means of a, it is advisable to protect the paper for the photoconductive corona discharge by means of an insulating layer maintained at 6000 volts against the penetration of the coating charging device. B. paper processing solution to pretreat z. B. with MethylceUulose or Aluminum FoUe or KunststoffoUe, with the senin aqueous solution or polyvinyl alcohol in an aqueous sealed layer under a template or by solution or the solution of a mixed polymer from 6 ° episcopic or diascopic projection exposed and acrylic acid methyl ester and acrylonitrile in acetone and with a carbon black colored resin powder in well-known methyl ethyl ketone or solutions of polyamides in dusted manner. The picture that becomes visible in the process is aqueous alcohols. Aqueous dispersions of this type can also be easily wiped off. It is therefore fixed, which can be used to pretreat the paper surface, for example by briefly heating it to about 120 ° C. ⁶ 5 can be done with an infrared heater. The tempe- The solutions of the 2,5-bis- (p-aminophenyl) -l, 3,4-ox- temperature can be reduced if the thermal diazoles, optionally mixed with the resins, act in the presence of vapors of solution customary W ^r else on the documents listed agents, such as trichlorethylene, carbon tetrachloride or carry z. B. takes place by spraying, brushing, on-ethyl alcohol. Also by treatment with a spin or in any other form, and then so 7 ο water vapors, the fixation of the powder images is possible.

borrowed. Positive images are created after positive templates, which are characterized by a good contrast effect.

A very particular advantage of the electrophotographic images produced according to the invention is that after fixing they can also be converted into a printing form if the substrate, for. B. the paper or the plastic film, wiped with a solvent for the photoconductive layer, for example with alcohol or acetic acid. The non-image parts of the layer are removed so that the substrate can then be moistened with water. It is then rolled in in a known manner with bold paint that only adheres to the image areas. In this way, positive printing forms are obtained which, after being clamped into an offset machine, can be printed. The print runs are very high.

If transparent substrates are used, the electrophotographic images can also be used as templates for further copying onto any high-sensitivity layer. The invention photoconductive compounds to be used are the substances used so far, such as selenium, or zinc oxide, About Legan in this regard, since the latter only dim, give no copy layers because can be produced with .diesen materials no solid solutions, but only suspensions.

Even on the reflex path, when using highly permeable substrates for the inventive photoconductive layers images are produced. The possibility of a reflex copy is also an advance compared to the state of the art.

In addition, the photoconductive layers composed according to the invention have another one great advantage because they can be charged both positively and negatively. When the charge is positive, .the images are particularly good and the formation of ozone is barely noticeable, those with a negative charge are very strong emerges and, because it is harmful to health, requires special measures, e.g. B. the arrangement of Fans.

example 1

A solution containing 30 g of benzene 1 g of 2,5-bis- [4'-dimethylaminophenyl- (r)] - 1,3,4-oxdiazole corresponding to formula 1 and 1 g of indene resin (e.g. that under the trade name "TC-Harzii available product) contains, is on a paper foil, the surface of which against the Penetration of organic solvents is pretreated, applied and dried. Be on this paper creates direct images according to the electrophotographic process, which happens as follows: Through a Corona discharge, the paper is electrically charged positively or negatively, then under a positive original by means of a high-pressure mercury lamp and dusted with a resin powder colored with soot. The finely divided resin remains on the layers not struck by light during the exposure adhere, and a positive image becomes visible, which is slightly warmed and thereby made durable (fixed). It - shows a good contrast effect, since the base of the paper is exposed by the applied substances.

If the carrier for the photoelectric layer is not paper as above, but a suitable transparent one If plastic or transparent paper is used, the images produced are used as master copies for the Production of reproductions on light, sensitive layers suitable.

The compound with the formula 1, 2,5-bis- [4'-dimethylaminophenyl- (1 ')] -1,3,4-oxdiazole, is produced as follows: In a solution of 13 g of hydrazine sulfate in

250 g of oleum (24% SO ₃ ) are introduced with cooling, 36 g of 4-dimethylaminobenzoic acid. The reaction mixture is then heated to 60 to 70 ° C. for 2 to 3 hours with stirring, then poured onto ice, made weakly alkaline with sodium hydroxide solution with cooling and the condensation product which has precipitated is filtered off with suction. The resulting oxdiazole compound (formula 1) is washed out and dried and represents a tan powder, the solutions of which fluoresce blueish in ultraviolet light. The compound has a melting point of 225 to 227 ° C. and is known from French patent 1,080,107.

Example 2

One carries a solution made up of 30 g of methylene chloride

Contains 1 g of 2,5-bis [4'-öHäthylanunophenyl- (l ')] - 1,3,4-oxdiazole corresponding to formula 2 and 2 g of coumarone resin (for example the commercial type 701/70) on an aluminum foil. After the solvent has evaporated the applied oxdiazole layer adheres firmly to the aluminum surface. With the coated aluminum foil As described in Example 1, images can be produced electrophotographically. By hanging up one Sheet of paper on the soot-resin-powder dusted, unfixed image and another exposure to a Corona discharge, the soot-resin-powder image is transferred from the aluminum foil to the paper on which a reversed image is created. Will the carbon black resin image be printed on transparent paper or transparent plastic film transferred, the image obtained can be copied further, for example on Diazo high-quality tracing paper.

The compound according to formula 2, 2,5-bis- [4'-diethylaminophenyl- (l ')] -1, 3,4-oxdiazole, is prepared analogously to the compound according to formula 1 from 13 g of hydrazine sulfate and 42 g of 4-diethylaminobenzoic acid in 250 g oleum (24% SO ₃ ) produced. The reaction mixture is heated to 60 to 70 ° C. for 3 hours with stirring, then poured onto ice, made weakly alkaline with sodium hydroxide solution while cooling, and the condensation product which has formed is filtered off with suction. This is purified by recrystallization from 96% alcohol and melts at 152 to 153 ° C

In the method described above, polyphosphoric acid can also be used as a condensing agent instead of oleum will. In this FaU, 13 g of hydrazine sulfate in 200 g of polyphosphoric acid are carried at room temperature one, then 42 g of 4-diethylaminobenzoic acid are added and the mixture is heated to 80 ° C. for 2 hours warmed up. When everything has gone into solution, the syrupy condensation product is poured onto ice. Of the Excessive precipitate is filtered off with suction, washed with water and recrystallized from 96% alcohol.

Example 3

1.5 g of 2,5-bis [4'-dimethylaminophenyl- (l ')] - 1,3,4-oxdiazole (formula 1), 0.5 g of 2,5-bis [4' - diethylaminophenyl- (l ')] - 1,3,4-oxdiazole (Formula 2) and lg one produced by condensation of cyclohexanone with methylcyclohexanone Synthetic resin (e.g. the product available commercially under the name Synthetic Resin AW2), are dissolved in 50 g of benzene and then applied to paper made according to the procedures of USA patents

2,534,650, 2,681,617 or 2,559,610. The after evaporation of the solvent on the The remaining layer of paper adheres firmly to the surface. In the electrophotographic process, as in As described in Example 1, images with a good contrast effect on white are produced on this coated paper Reason generated. If a printing form is to be produced, the image and the paper are fixed by heating

wiped over on which the image-bearing side with 96% alcohol or 50 ° / ₀ acetic acid, rinsed well with water and rubbed with greasy ink and l% phosphoric acid. Positive printing forms are obtained from positive templates, from which printing can be carried out using an offset machine.

Example 4

0.5 g of 2,5-bis [4'-isoamylammophenyl- (l ')] - 1,3,4-oxdiazole corresponding to the formula 3, 1.5 g of 2,5-bis [4'-n- propylaminophen3'l - (r )] - l, 3,4-oxdiazole according to the formula 4, 1 g rosin-formaldehyde resin (e.g. the resin marketed under the trademarked name "Corepal 140") and 0.01 g of methylene blue (Schultz, "Farbstofftabellen", 7th edition, first volume, p. 449) are dissolved in 30 g of benzene, and the solution is applied to a paper film of the type used in the example and dried. The paper coated in this way is electrically charged in a known manner and can be discharged with a high-pressure mercury lamp or with a lightbulb, which leads to the generation of an image of the original when an original is inserted. The addition of methylene blue enables the exposure time to be shortened to a fifth of the time required in the absence of the sensitizer.

2,5-bis- [4'-isoamylaminophenyl- (1 ')] -1,3,4-oxdiazole (formula 3) is obtained by adding 43 g of 4-isoamylaminobenzoic acid to a solution of 13 g of hydrazine sulfate in 250 g Oleum (24% SO ₃ ) with cooling and further treatment of the reaction mixture analogously to the method given for the compound with formula 1 in Example 1; the compound corresponding to formula 3 melts at 130 to 132 ° C. 2,5-bis- [4'-n-propylaminophenyl- (l ')] -1, 3,4-oxdiazole (formula 4) is in ana-. Logically prepared using 39 g of 4-n-propylaminobenzoic acid, it melts at 137 to 139 ° C. Both compounds can also be prepared using polyphosphoric acid instead of oleum.

In the solution used for coating the paper film, each of the compounds can be used according to the Formulas 3 and 4 or one of them by the same amount of the compound 2,5-bis- [4'-cyclopentylaminophenyl- (l ')] - 1,3,4-oxdiazole can be replaced according to formula 5. This compound, operating at 118 to 120 ° C melts, is obtained by condensation of 13 g of hydrazine sulfate with 41 g of 4-cyclopentylaminobenzoic acid in 250 g Oleum analogous to that in Example 1 for the preparation of 2,5 - bis - [4 '- dimethylaminophenyl - (I')] - 1,3,4-oxdiazole specified procedure. 4-Cyclopentylaminobenzoic acid is obtained by adding 68.5 g of 4-aminobenzoic acid dissolves with 33 g of potassium carbonate in 300 ecm of water and the solution with 74.5 g of bromocyclopentane am Reflux boils for 6 hours. After the reaction mixture has cooled down, crystals separate out be recrystallized from 96% alcohol. 4-Cyclopentylaminobenzoic acid melts at 128 to 130 ° C

Example 5

In 30 g of benzene, 0.5 g of 2,5-bis- [4'-cyclohexylaminophenyl- (l ')] - 1,3,4-oxdiazole (formula 6), 1 g of 2,5-bis [4 '- (di-n-propyl) -aminophenyl - (r )] - l, 3,4-oxdiazole (formula 7) and 1 g of resin-modified maleic acid resin (e.g. the one under the trademark> -Beckacite K 125 « commercial product) and applies the benzene solution to a surface roughened aluminum foil. After the solvent has evaporated, the remaining layer adheres firmly to the surface of the foam. Man

Proceeds for the production of an image as described in Example 1, and if a positive original is used, a positive image is obtained, which is also fixed as indicated in Example 1. This image can be converted into a positive printing form by wiping the aluminum foil on the side carrying the image with alcohol (96%), rinsing with water and rubbing it with greasy paint and 1% phosphoric acid.
2,5-bis [4'-cyclohexylaminophenyl - (r )] - 1,3,4-oxdiazole (melting point 186 to 187 ° C.) is obtained by condensing 13 g of hydrazine sulfate with 48 g of 4-cyclohexylaminobenzoic acid in 260 g of oleum (24% SO ₃ ) analogous to the compound corresponding to formula 1, which is described in example 1. 2,5-bis- [4 '- (di-n-propyl) aminophenyl- (l')] - 1,3,4-oxdiazole (melting point 137 to 138 ° C.) are also obtained from 13 g of hydrazine sulfate and 48 g 4- (di-n-propyl) -aminobenzoic acid in oleum analogous to the procedure given in Example 1.

Example 6

0.5 g each of 2,5-bis [4'-acetylaminophenyl- (l ')] - l, 3,4-oxdiazole (formula 8) and 2,5-bis [4'-acetylamino-2'- chlorophenyl- (l ')] - 1,3,4-oxdiazole (Formula 9) and 1 g of resin-modified maleic acid resin (e.g. the one under the trademark law Uch protected name »Beckacite K 105«) are sold in 30 g of methylene chloride are dissolved, and the solution is transferred onto a paper sheet of the same type as that in Example 1 used, applied and dried. The coated ο paper foil is then further processed to produce an image, as indicated in example 1. A positive image is obtained from a positive original.

Instead of each of the compounds according to formulas 8 and 9 or one of them can be used for the preparation the same amount of 2,5-bis- [4 '- (n-propylamino) -2'-chlorophenyl- (1')] - !, 3,4-oxdiazole, of the spotting solution described above (Formula 10) can be used.

Analogously to the method of preparation described in Example 1 for the preparation of 2,5-bis- [4'-dimethylaminophenyl- (l ')] -1, 3,4-oxdiazole, 2,5-bis- [4'-acetylaminophenyl- (l ')] - !, 3,4-oxdiazole (melting point 262 to 263 ° C.) by condensation of 13 g of hydrazine sulfate with 39 g of 4-acetylaminobenzoic acid in 250 g of oleum (24% SO ₃ );

2,5-bis- [4'-acetylamino-2'-clilorphenyl- (l ')] - 1,3,4-oxdiazole (melting point 169 to 170 ° C.) by condensation of 13 g of hydrazine sulfate with 21 g of 4-acetylamino -2-chlorobenzoic acid in 240 g oleum (24% SO ₃ );

2,5-bis- [4'- (n-propylamino) -2'-chlorophenyl- (l ')] - 1,3,4-oxdiazole (melting point 132 to 140 ° C) by condensation of 13 g of hydrazine sulfate with 45 g of 4-n-propylamino-2-chlorobenzoic acid in 260 g of oleum (24% SO ₃ ).

Example 7

1 g of 2,5-bis- [4'-diethylaminophenyl - (r )] - 1,3,4-oxdiazole (formula 2) and 1 g of phenol-modified synthetic resin (e.g. that produced by polycondensation and under the trademark law Uch protected name “Rhenophen 140”) are dissolved in 30 g of benzene. This solution is applied to a non-transparent but impermeable paper, the surface of which has been pretreated against the penetration of organic solvents, and the coated paper is dried. After drying, it is electrically charged by means of a corona discharge, the layer side is placed on a book page that is printed on both sides and backed with black paper, and a 100-watt light bulb is used for 4 seconds. The fear occurs through the non-transparent, but non-permeable paper. After dreading, the reflex image is covered with a resin stained by soot

powdered. A very high-contrast, positive, reversed image is obtained. When you look at the If the image obtained is firmly pressed on paper or a plastic film, the image is transferred and one obtains a right-sided image on the paper or on the foil. When producing the right-sided image, one can also, as it is known per se, apply an electric field to the paper or the film, which is the right way round Take picture. If the paper or foil is transparent, you get intermediate originals to continue pausing, e.g. B. on blueprint paper.

Example 8

1 g of 2,5-bis [4'-ethylaminophenyl- (l ')] - 1,3,4-oxdiazole according to formula 11 and 1 g of ketone resin (e.g. the commercially available synthetic resin EM) are dissolved in 30 g of glycol monomethyl ether, and the solution is applied to paper and dried. The coated paper foil is used to produce an image Proceed as described in Example 1. From a positive template, you get a very high-contrast one positive picture.

2,5-bis [4'-ethylaminophenyl- (l ')] - 1,3,4-oxdiazole (formula 11), which melts at 160 to 161 ° C, is by condensation of 36 g of 4-mono-N -äthylamino-l-benzoic acid with 13 g of hydrazine sulfate in 250 g of oleum (24% SO ₃ ) analogous to that in Example 1 for the preparation of 2,5-bis, [4'-dimethylaminophenyl- (Γ)] -1.3 , 4-oxdiazole indicated "nen procedure shown.

Example 9

1 g of the compound corresponding to formula 12, lg ketone resin, z. B. the synthetic resin EM listed in Example 8, and 0.01 g of Rhodamine B (Schultz, »Dye Tables 7th Edition, First Volume [1931], No. 864) are dissolved in 30 g of glycol monomethyl ether, and the solution is applied to paper bark dried. After charging by a corona discharge, the now sensitized paper is ^{exposed under a positive template with a 100 watt light bulb for 1} _1/2 seconds and dusted with a resin powder colored with soot. A positive image is created, which is fixed by heating. After fixing, black images are obtained on a colorless background.

The compound corresponding to the formula 12, 2,5-bis- [4'-N-ethyl-Nn-propylaminophenyl- (l ')] -1, 3,4-oxdiazole with a melting point of 98 ° C, is analogous to that in im Example 1 for the compound according to formula 1 indicated procedure by condensation of 20.5 g of 4-N-ethyl-Nn-propylaminobenzoic acid with 13 g of hydrazine sulfate in 250 g of oleum (24% SO ₃ ).

The N-ethyl-N-n-propylaminobenzoic acid is obtained in analogy to that described at the end of Example 4 4-Cyclopentylaminobenzoic acid is prepared by boiling a solution of 16.5 g for several hours 4-N-ethylaminobenzoic acid and 13.8 g of potassium carbonate in 80 ecm of water after adding 12.3 g of bromopropane with re-nut cooling.

Example 10

The procedure is as in Example 1, but a solution of 0.5 g of the is used for coating paper Compound corresponding to formula 2 and 0.5 g of the compound corresponding to formula 11 in 30 g of glycol monomethyl ether. The images obtained are very high-contrast and positives from positive originals. the Images can also be generated from book pages with letters on both sides by means of episcopic projection will. Half and full tones are reproduced with high contrast.

Example 11

1 g of the compound corresponding to formula 13, 1 g of ketone resin (e.g. the synthetic resin listed in Example 8 EM) and 0.02 g of the cyanine dye of the following constitution

H ₂ CSS -

, C = CH-CH = CH-C

-CH ₉

XH _a

CH ₃

H _a C '

SO ₁ -CH,

- Are dissolved in 30 g of glycol monomethyl ether, and the solution is applied to paper and dried. After being charged by a corona discharge, the sensitized paper is placed under a positive template exposed for 1 second with a 100 watt light bulb at a distance of about 15 cm and, as in example 1 indicated, dusted with a resin powder stained with soot. The result is a positive image that comes through Heating is fixed.

The compound corresponding to the formula 13, -2,5-bis- [4 '- (N-ethyl-N-acetyl) -aminophenyl- (l')] -1, 3,4-oxdiazole with a melting point of 156 ° to 157 ° C, is prepared from 2,5-bis [4'-ethylaminophenyl- (l ')] - l _i 3,4-oxdiazole according to formula 11 by boiling with acetic anhydride for 4 hours. After the reaction has ended, the reaction mass is poured into water, after a few 30 hours the new compound separates out according to Formula 13 and is recrystallized from alcohol after washing with water beforehand.

Example 12

lg of the compound corresponding to formula 1, lg "zinc resinate 357" (a commercially available zinc resinate) and 0.02 g acid violet 6 BN (Schultz, "color tables", 7th edition, first volume, no. 831) are in 30 g Glycol monomethyl ether dissolved and applied to paper and dried. After charging by a corona discharge, the sensitized paper is exposed under a positive original using a 100 watt bulb at a distance of about 15 cm ¹ Z ₄ seconds and, as indicated in Beispiell, dusted with a stained by soot resin powder. A positive image is created, which is fixed by heating.

Example 13

The procedure is as in Example 1, but a solution of 1 g of the compound is used to coat paper according to the formula and 1.5 g of a polymerized natural resin (e.g. that under the; Name Hercules-Poly-Pale traded resin) in 30 g of glycol monomethyl ether. You get positive images.

Instead of the above resin, a resin consisting mainly of dimerized abietic acid (e.g. the resin »Hercules-Dpolymerx«) or a hydrogenated natural resin (e.g. the commercial product »Hercules-Staybelite«) be used.

Example 14

A paper stock is mixed with a solution of IOg post-chlorinated polyvinyl chloride, e.g. B. the one in the trade available plastic »RhenofLex«, coated in 100 g acetone and dried. After drying it will this paper with a solution of 1 g of the compound corresponding to formula 2 and 1 g of ketone resin (for example the synthetic resin AP) coated in 30 g of glycol monomethyl ether and, as indicated in Example 1, further treated. When exposing the with a

909 529/407

Claims (3)

With a positive charge, i.e. sensitized, paper lint of a template with a 100 watt light bulb at a distance of about 15 cm, very high-contrast images are obtained after just L second. . Example 15 1 g of 2- [4'-diethylaminophenyl- (1 ')] - 5- [4 "-dimethylaminophenyl- (1")] - 1,3,4-oxdiazole corresponding to formula 14 and 1 g of a natural resin , for example Manila copal, are dissolved in 50 g of glycol monomethyl ether. The solution is applied to transparent paper and dried. Proceed as indicated in Example 1. The electrophotographically produced images are suitable as master copies for the production of copies on any light-sensitive layers. Instead of the compounds corresponding to formula 14, 2 - [4 '- dimethylaminophenyl - (1')] - 5 - [4 "- amino-3" -chlorophenyl- (1 ")] - 1,3,4-oxdiazole according to the Formula 17. The compound according to formula 14 is prepared as follows: A mixture consisting of 19, 3 g of 4-diethylaminobenzoic acid and 16.5 g of 4-dimethylaminobenzoic acid are added.The reaction mixture is then heated to 60 ° C. for 4 hours with stirring Washed water ?, and purified by recrystallization from 80% ethyl alcohol. The poorly soluble 2,5-bis- [4 '- (umethylaminophenyl- (l')] - 1,3,4-oxdiazole (formula 1), which is separated off by repeated crystallization of the reaction product from 80% ethyl alcohol . 2- [4'-Diethylaminophenyl- (l ')] - 5- [4 "-dimethylaminophenyl- (l")] - 1,3,4-oxdiazole melts after recrystallization at 158 to 160 ° C. The compound corresponding to the formula 17 is obtained analogously to the compound corresponding to formula 14 from 13 g of hydrazine sulfate, 250 g of oleum (24% SO3) and a mixture of 16.5 g of 4-dimethylaminobenzoic acid and 17.2 g of 4-amino-3-chlorobenzoic acid. The compound corresponding to formula 17, 2- [4'-dimethylaminophenyl- (10] -5- [4 "-amino-3" -chlorophenyl- (1 ")] - 1,3,4-oxdiazole, is also used obtained by repeated recrystallization from 80% ethyl alcohol. It melts at 216 to 217 ° C. Example 16 The procedure described in Example 1 is followed, but a solution of 1 g of 2- [4'-mono-n- propylaminophenyl- (l ')] - 5- [4 "- dimethylaminophenyl- (l")] - 1,3,4-oxdiazole corresponding to formula 15 and 1 g of 2- [4'-mono-n-propylaminophenyl ( l ')] - 5- [4 "- monoethylaminophenyl- (1")] -1,3,4-oxdiazole corresponding to formula 16 in 30 g glycol monomethyl ether. The electrophotographically obtained images are very high in contrast. The compound corresponding to formula 15 is prepared analogously to the compound corresponding to formula 14 from 13 g of hydrazine sulfate, which are dissolved in 250 g of oleum (24% SO3), and a mixture of 17.9 g of 4-mononopropylaminobenzoic acid and 16.5 g of 4-dimethylaminobenzoic acid Reaction product 2- [ 4 '-Mono -n-propylaminophenyl- (1')] - 5- [4 "-dimethylaminophenyl- (1")] - lJ3,4-oxdiazole is purified by fractional crystallization from 80% ethyl alcohol and has a melting point of 148 bis 150 ° C. The compound of formula 16 is also represented analogously to the compound corresponding to formula 14. After 13 g of hydrazine sulfate have been dissolved in 250 g of oleum (24% SO3), a mixture of 17.9 g of 4-mononopropylaminobenzoic acid and 16.5 g of 4-monoethylaminobenzoic acid is added to the solution. The reaction mixture is worked up like that of the compound according to formula 14. The reaction product, 2- [4'-mono-n-propylaminophenyl- (l ')] - 5- [4 "-monoethylaminophenyl- (l")] - l , 3,4-oxdiazole, is purified by recrystallization from 80% ethyl alcohol; it melts at 126 to 127 ° C. Example 17 10 g of post-chlorinated polyvinyl chloride (for example the product commercially available under the trademark "Rhenoflex") are dissolved in 100 g of methyl ethyl ketone. To this solution, first 10 g of the compound corresponding to formula 1 are dissolved in 50 g of toluene and then 0.011 g of Rhodamine B extra (Schultz, "Dye tables", 7th edition, Vol. I [1931], No. 864) in 2 g Dissolved methanol is added. The resulting solution, which has a kinetic viscosity of about 20.8 cSt (17.1 cP), is used to machine-coat paper using a casting device. The layer thickness obtained is about 6 μ. Direct images are formed on this paper by the electrophotographic process in the manner indicated in Example 1. The photosensitivity 30 · of the paper is very high. In the episcopal way:. very high-contrast images can be generated from originals labeled on both sides in 1 second = at a light intensity of around 30 lux. Example 18 10 g of a product produced by post-chlorination of polyvinyl chloride (for example the plastic marketed by Dynamit Aktiengesellschaft in Rheinfelden under the trademark "Rhenoflex") are dissolved in 100 g of methyl ethyl ketone. First a solution of 10 g of the compound corresponding to formula 1 in 50 g of toluene and then a solution of 0.004 g of ethyl violet are added to this solution (Schultz, "Farb-Stofftabellen", 7th edition, Vol. I [1931], no. 787) in 2 g of methanol. A paper stock is machine coated with the solution thus obtained, which has a kinetic viscosity of about 20.8 cSt (17.1 cP). The thickness of the applied layer should advantageously be about 6 μ. After the applied layer has dried, the paper is negatively charged by a corona discharge and a latent image is then created on this paper by episcopal means of a book page written on both sides. The paper is now treated on its layer side with a developer consisting of small glass beads and a very finely divided resin-carbon black mixture. The black colored resin adheres to the areas of the layer that are not struck by light during observation, and a positive image becomes visible, which is slightly heated and thereby made durable (fixed). It shows good contrast. Claims-. 1. Material for electrophotographic reproduction consisting of a conductive pad and a photoconductive iso-layer adhering thereon, characterized in that the iso-layer is used as containing photoconductive substances 2,5-bis- (p-aminophenyl) -1,3,4-oxdiazole or from these bodies consists. 2. Material for electrophotographic reproduction according to claim 1, characterized in that the oxdiazoles in the iso layer in a mixture with present organic colloids, optionally in the form of solid solutions with the colloids. 3. Material for electrophotographic reproduction according to claim 1 and 2, characterized by the presence of sensitizers in the iso-layer. 1 sheet of drawings © 909 529/407 5.59