DE1954500B2 - ELECTROPHOTOGRAPHIC RECORDING MATERIAL - Google Patents

Description

where X is an oxygen or sulfur atom and p, q and r is an integer between 2 and 6, or

d) a cycloalkylene radical of the formula

where Q is the same as the atoms required to complete a cycloalkylene radical having 3 to 6 carbon atoms and u and ν are an integer between 0 and 5 and

D, D ', E and E' each represent a hydrogen or Halogen atom or an alkyl or alkoxy radical preferably each having 1 to 8 carbon atoms or an aryl or aryloxy radical.

3. Electrophotographic recording material according to claim 2, characterized in that that it contains a mixed polyester from 20 to 80 mol percent, preferably 30 to 60 mol percent, Units of the formula A and from 80 to 20 mol percent, preferably 70 to 40 mol percent, Units of the formula B or from 20 to 80 mol percent, preferably 30 to 60 mol percent, Units of the formula C and from 80 to 20 mole percent, preferably 70 to 40 mole percent, of units of formula D.

4. Electrophotographic recording material according to claim 2, characterized in that that there is a terephthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-trimethylene mixed polyester as a mixed polyester, an isophthalic acid - 4,4 '- isopropylidene-bis-phenoxyethyl-trimethylene mixed polyester, a terephthalic acid - 4,4 '- isopropylidene-bis-phenoxyethyl-tetramethylene mixed polyester, an isophthalic acid - 4,4 '- isopropylidenebis - phenoxyethyl - tetramethylene - mixed polyester, an isophthalic acid - 4,4 '- isopropylidene - bisphenoxyäthyl - äthykn - mixed polyester, a Terephthalic acid -4,4 '- isopropylidene - bis - phenoxyethyl - pentamethylene - mixed polyester, an isophthalic acid - 4,4 '- isopropylidene - bis - phenoxyethyl-pentamethylene mixed polyester, a terephthalic acid - 4,4 '- isopropylidene - bis - phenoxyethy! - oxydiethyl mixed polyester or an isophthalic acid-4,4'-isopropylidene-bis-phenoxyäthyloxydiethyl-M contains ischpolyester.

5. Electrophotographic recording material according to claim 1, characterized in that that the photoconductive layer 10 to 60 percent by weight 4,4 '- benzylidene - bis - (N, N - diethylm-toluidine) as a photoconductor.

6. Electrophotographic recording material according to claim 1, characterized in that that the photoconductive layer is a cyanine or carbocyanine dye or a pyrylium, a thiapyrylium or contains a selenapyrylium dye salt as a sensitizer.

The invention relates to an electrophotographic recording material which consists of a layer support and at least one photoconductive layer comprising an alkylidene-bis-aryloxyalkyl-alkylene mixed polyester as a binder, a photoconductor dispersed therein and optionally a sensitizing dye consists.

It is known that for the production of photoconductive layers of electrophotographic recording materials a wide variety of binders can be used. Typical known binders are usually polymeric substances such. B. phenolic resins, ketone resins, acrylic resins and polystyrene resins. Such Binders neither contribute to nor increase the photosensitivity of the photoconductive layers they same. The photosensitivity of the photoconductive layer of an electrophotographic recording material, which manifests itself in the electrical sensitivity of the layer is normally based solely on the sensitivity of the photoconductor contained therein as well as any contained therein Sensitizing dye for the photoconductor.

From U.S. Patents 2,663,636, 3,121,006, 3,141,770 and 3,234,280 and from the book of Create. "Electrophotography". Publishing house Focal Press. 1965. pp. 235 to 262, it is also already known. that certain binders are also sensitive to light contribute to the photoconductive layer of electrophotographic recording materials can. However, it has been shown that such binders only act on very specific photoconductors address, d. H. that these binders only contribute to the sensitivity of the photoconductive layer, when used in conjunction with certain photoconductors.

The polyester binders known from US Pat. Nos. 3,141,770 and 3,234,280, for example, have proven to be advantageous binders of this type which can be used for the production of photoconductive layers of electrophotographic recording materials. These polyesters are terephthalic acid-2,2-bis-4 - (ß- hydroxyethoxy) - phenylpropane - ethylene - mixed polyester. The molar ratio can be, for example, 2: 1: 1, but the glycol component can also be used in a weight ratio of, for example, 9: 1.

The disadvantage of these known mixed polyesters used as binders is, as already mentioned, that they only combine their photosensitivity-improving effect of the photoconductive layer with very special photoconductors

There was therefore a need for further, the photosensitive wedge of the photoconductive layer of Cleklrophotographic recording materials increase binders, their photosensitivity the photoconductive layer improving effects

cung is independent of the photo conductor used in each case.

The object of the invention is therefore to provide an electrophotographic recording material, which contains a binder 5 in the photoconductive layer which is capable of independently of each photoconductors used to improve the photographic sensitivity of the photoconductive layer.

It has now been found that this object can be achieved in that for the production of the photoconductive Layer of an electrophotographic recording material as a binder Mixed polyesters can be used.

The invention is an electrophotographic recording material, which consists of a Layer support and at least one photo-capable layer with an alkylidene-bis-aryloxyalkyl-alkylene mixed polyester as a binder, a photoconductor dispersed therein and optionally a sensitizing dye consists and is characterized in that the polyester consists of a terephthalic acid-alkylidene-bis-aryloxyalkyl-alkylene mixed polyester with 3 to 10 carbon atoms in the alkylene radical or an isophthalic acid - alkylidene - bis - aryloxyalkyl - alkylene - mixed polyester with 2 to 10 carbon atoms in the alkylene radical.

The electrophotographic recording material of the invention differs from the analog ones known electrophotographic recording materials constructed advantageously by that the mixed polyester binder contained in the photoconductive layer has its sensitivity

the photoconductive layer has an increasing effect, regardless of which particular photoconductor is dispersed therein, that is, a wide variety of known inorganic or organic photoconductors can be used.

The electrophotographic recording material of the invention is preferably transparent.

Those with the electrophotographic recording material of the invention comparable to others known electrophotographic recording materials achievable improvement in sensitivity can be easily determined by comparing the electrophotographic Recording materials up to a suitable voltage, e.g. B. 500 to 600 volts, charges and determines the reciprocal value of the exposure as the relative sensitivity of the photoconductive layer, which is required to increase the surface tension of the photoconductive layer by 100 volts (shoulder sensitivity) or to reduce it to 100 volts (sensitivity in the sag area). The degradation the surface tension to 100 volts or a value below is therefore of crucial importance, because this reduction in surface tension is a prerequisite for good development of the latent image. Thus the relative sensitivity at 100 volts is a measure of the ability the photoconductive layer to produce a technically useful, developable, latent image in it.

According to one embodiment of the invention, the electrophotographic recording material contains a linear mixed polyester with arbitrarily repeating units of the formulas

-CH ₂ -CH ₂ -O

ODO

-CH ₂ -CH ₁ -O

CH,

! c

CH,

where means

Z a) a straight or branched one. optionally substituted Alkylenresl with 3 to 10 carbon atoms,
b) an oxydialkylene or thiodialkyl radical of the formula

where X is an oxygen or sulfur atom and η and m is an integer between 2 and 7,
c) an alkylene-bis (oxyalkylene) or alkylene-bis (thioalkylene) radical of the formula

- (CH ₂ ), - X —i CH ₂ ) -

where X is an oxygen or sulfur atom and p, q and r is an integer between 2 and 6, or
d) a cycloalkylene radical of the formula

C- (CH ₂ ) ;;

where Q is equal to the atoms required to complete a cycloalkylene radical with 3 to 6 carbon atoms and u and i 'are equal to an integer between 0 and 5,

Z 'a) a straight or branched, optionally substituted alkylene radical having 2 to 10 carbon atoms,
b) an oxydialkylene or thiodialkylene radical of the formula

- (CH ₂ ) ^ - X- (CH

where X is an oxygen or sulfur atom and π and m is an integer between 2 and 7,

c) an alkylene-bis (oxyalkylene) or alkylene-bis (thioalkylene) radical the formula

where X is an oxygen or sulfur atom and p, q and r is an integer between 2 and 6, or
d) a cycloalkylene radical of the formula

C- (CH ₂ * -

where Q is equal to the atoms required to complete a cycloalkylene radical having 3 to 6 carbon atoms and u and γ are equal to an integer between 0 and 5 and

D, D ', E and E' each represent a hydrogen or halogen atom or an alkyl or alkoxy radical, preferably each having 1 to 8 carbon atoms, or one Aryl or aryloxy radical.

When Z and Z 'mean a straight-chain or branched-chain alkylene radical having 3 to 10 carbon atoms without a heteroatom, it can be trimethylene, for example. Tetramethylene. Isopropylene, pentamethylene. Act neopentylene or hexamethylene radicals.

If Z and Z 'have the meaning of oxydialkylene or thiodialkylene radicals, this can be the case for example, oxydiethylene radicals or thiodiethylene radicals.

When Z and Z 'denote alkylene-bis (oxyalkylene) or alkylene-bis (thioalkylene) radicals

ίο have it, for example Acting methylene bis (oxyethylene), ethylene bis (thioethylene) or ethylene bis (oxyethylene) radicals.

If Z and Z 'have the meaning of cycloalkylene radicals, it can be, for example

'5 to cyclohexylenedimethylene, cyclopentylenedimethylen, cyclobutylenedimethylene, cycJobutylenediethylen, Cyclobutylene or 2,2,4,4-tetramethyl-1,3-cyclobutylene residues Act.

The mixed polyesters used according to this embodiment of the invention have the advantage that they can be produced easily and economically from readily available starting materials.

According to a further embodiment of the invention, the photoconductive layer of the electrophotographic recording material contains a mixed polyester, the aub 2U to 50 mol percent, preferably 30 to 60 mol percent, units of the above formula A and from 80 to 20 mol percent, preferably 70 to 40 mol percent, units of the above Formula B or 20 to 80 mole percent, preferably 30 to 60 mole percent, units of the above formula C and 80 to 20 mole percent, preferably 70 to 40 mole percent, units of the formula D above.
As a result of this configuration, it is achieved that a particularly effective improvement in the electrophotographic sensitivity of the photoconductive layer is achieved.

According to a further embodiment of the invention, the photoconductive layer contains a cyanine or carbocyanine dye or a pyrylium, a thiapyrylium or a selenapyrylium dye salt as a sensitizer.

This configuration ensures that the electrophotographic sensitivity of the photoconductive Layer increases considerably.

According to a further embodiment of the invention, the photoconductive layer contains a mixed polyester the compounds given in Table I below, which are distinguished by the fact that they are excellent have film-forming properties and highly sensitive electrophotographic recording materials deliver.

Table I.

1. Terephthalic acid-4,4'-isopropylidene-bis-phenoxyethyi-trimethylene mixed polyester.

2. 4,4'-terephthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-tetramethylene mixed polyester,

3. 4,4-terephthalic acid-isopropylidene-bis-phenoxyethyl-pentamethylene mixed polyester.

4. Terephthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-oxydiethyien mixed polyester.

5. Terephthalic acid-4,4-isopropylidene-Hs-phenoxyethyl-neopentyl-Mischpolyestcr.

6. Terephthalic acid ^^ '- isopropylidene-bis-phenoxyethyl-cyclohexylenedimethylene mixed polyester,

7. 4,4'-terephthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-cydobutylenedimethylene mixed polyester,

209537/474

8. Terephthalic acid-W-isopropylidene-bis-phenoxyethyl-thiodiethylene mixed polyester,

9. Terephthalic acid - ^ '- isopropylidene-bisphenoxyälhyl-ethylene-bis (oxyethylene) mixed polyester,

10. Terephthalic acid 'M'-isopropylidene-bis-pheiiuxyethyl-ethylene-bis-thioethylene / mixed polyesters,

11. Terephthalic acid - ^ '- isopropyiiden-bis-phenoxyethy 1-2,2,4,4-tetramethyl-1,3-cyclobutylene mixed polyester,

12.Terephthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-tetramethylene-4-bromo mixed polyester,

13. Terephthalic acid 4,4'-isopropylidene-bis-phenoxyethyl-tetramethylene-5-phenoxy mixed polyester,

14. Terephthalic acid ^ '- isopropylidene-bis-phenoxyethyl-propylene mixed polyester,

15. Terephthalic acid 4,4'-isopropylidene-bis-phenoxyethyl-tetramethylene-2,5-dichloro mixed polyester,

16. Terephthalic acid 4,4'-isopropylidene-bis-phenoxyethyl-tetramethylene-5-methoxy mixed polyester,

17. Terephthalic acid 4,4'-isopropylidene-bis-phenoxyäihyl-tetramethylene-5-phenyl mixed polyester,

18.Isophthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-trimethylene mixed polyester,

19. Isophthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-tetramethylene mixed polyester,

20. Isophthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-ethylene mixed polyester,

21. Isophthalic acid ^^ '- isopropylidene-bis-phenoxyethyl-oxydiethylene mixed polyester,

22. Isophthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-neopentyl mixed polyester,

23. Isophthalic acid ^^ '- isopropylidene-bis-phenoxyethyl-cyclohexylene-dimethylene mixed polyester,

24. Isophthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-cyclobutylenedimethylene mixed polyester,

25. Isophthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-thiodiethylene mixed polyester,

26. Isophthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-ethylene-bis- {oxyethylene ! -Mixed polyester,

27.Isophthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-ethylene-bis- (thioethylene) mixed polyester,

28. Isophthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-2,2,4,4-tetramethyl-1,3-cyclobutylene mixed polyester,

29. Isophthalic acid ^^ '- isopropylidene-bis-phenoxyethyl-tetramethylene-4-bromo-Miscb.polyester,

30.Isophthalic acid - ^ '- isopropylidene-bis-phenoxyethyl-tetramethylene-5-phenoxy mixed polyester,

31.isophthalic acid - ^ '- isopropylidene-bis-phenoxyethyl-propylene mixed polyester,

32. Isophthalic acid ^^ '- isopropylidene-bis-phenoxyethyl-tetramethylene-2-chloro mixed poryester,

33. Isophthalic acid - ^ '- isopropylidene-bis-phenoxyethyl-tetramethylene-5-methoxy mixed polyester and

34. Isoph & alsäure-4,4'-isopropylidene-bis-plienoxyethyl-tetramethylene-S-phenyl mixed polyester.

According to a further embodiment of the invention, the photoconductive layer contains 10 to 60 percent by weight 4,4'-benzylidene-bis- (N, N-diethyl-m-toluidine) as a photoconductor. This photoconductor provides in combination with that used according to the invention Mixed polyester binder an electrophotographic Recording material that is characterized by its particularly high sensitivity

Those useful in making the electrophotographic recording materials of the invention Polyester binders can be prepared by conventional polyester manufacturing processes, e.g. B. according to usual Melt condensation process, are produced. The production of isophthalic acid-4,4'-isopropylidene-bis-phenoxyethyl-ethylene mixed polyesters can be done, for example, as follows:

0,15MoI dimethyl isophthalate, 0.075 mole of 4,4'-isopropylidene-bisphenoxyäthanol, 0,10MoI ethylene glycol and 0.05 g of tetrabutyl orthotitanate are mixed together and heated to 200 ⁰ C while distilling off the methanol for 2 hours. The temperature is then increased to 250 ^° C., whereupon a vacuum is applied until the condensation has ended. In this way, a polymer having 50 percent by weight of recurring units of the formula A and 50 percent by weight of recurring units of the formula B can be obtained.

The Ί eri.phthalic acid-4,4-isopropylidene-bis-phenoxyethyl-tetramethylene mixed polyester can be prepared, for example, by the same process if dimethyl isophthalate by dimethyl terephthalate and ethylene glycol can be replaced with tetramethylene glycol.

The other polymers can be produced by the same process by adding the corresponding Glycols are used. For example, Polymers No. 1 and No. 18 can be used of trimethylene glycol, polymers No. 2 and 19 using tetramethylene glycol and prepare polymers # 4 and # 20 using diethylene glycol.

The electrophotographic recording materials of the invention can be prepared by conventional methods getting produced. A photoconductor, preferably an organic photoconductor, is expedient in this case a solution of the Polye.sterbindels dissolved, whereupon the mixture, optionally after adding a sensitizer for the photoconductor, after thorough mixing is applied to an electrically conductive layer substrate, which is achieved, for example, by fluidized coating, Can be sprayed on or coated with a coating knife.

The polyester binders used according to the invention increase or improve the electrical sensitivities the most diverse known photoconductors, both inorganic and organic Photoconductors, such as zinc oxide, titanium dioxide and cadmium sulfide as well as the most diverse, below listed photoconductors, including photoconductors made from organometallic compounds exist.

For the production of the recording material according to the invention, for example, are particularly suitable the following organic photoconductors:

A. The aryiamine photoconductor of the United States patents 3 240597, 3 180730 and 3 265496 known type,

B. Polyarylalkane photoconductor of the US patent 3,274,000 and French patents 1,383,461 and 1,519,059 Type,

C. 4-Diarylamino-substituted chalcones from the French patent 1561370 known Type,

D. nonionic cycloheptenyl compounds des from the Belgian patent 708638 known type.

E. Photoconductor with a

N-N core

of the type known from French patent specification 1 556 265,

F. 3,3'-bis-3ryl-2-pyra? Oline des from the Belgian Patent specification 720 146 known type,

G. Triarylamines substituted by vinyl or vinylene radicals from the German Offenlegungsschrift 1 908 343 known type,

H. Triarylamine photoconductor substituted by a radical with an active hydrogen atom are of the type known from German Offenlegungsschrift 1 908 345,

I. organometallic photoconductors, d. H. organometallic Compounds of metals of groups IVa and Va with an aminoaryl radical, des from the Belgian patent 717 265 known type as well

J. a wide variety of other organic photoconductors or compounds exhibiting photoconductive properties such as known from Australian patent specification 248402 Links.

25th

The photoconductive layers of the electrophotographic recording materials according to the invention can be sensitized by adding common sensitizers. To raise awareness you can the most varied of the usual sensitizers that are used to sensitize the most varied of photoconductors used, used.

Advantageous sensitizers which are used for the production of the electrophotographic recording material may be used according to the invention are, for example, pyrylium, thiapyrylium and selenapyrylium oxygen salts of the type known from U.S. Patent 3,250,615, fluorenes, e.g. B. 7,12-dioxo-13 - dibenzo (a, h) fluorene, 5,10 - dioxy - 4a, l 1 - diazabenzo (b) fluorene and 3,13-dioxo-7-oxadibenzo (b, g) fluorene. aromatic nitro compounds of the type known from U.S. Patent 2,610,120. Anthrones of the type known from U.S. Patent 2,670,284, quinones of the U.S. Patent 2,670,286, benzophenones of the type known from U.S. Patent 2,670,287. Thiazoles, z. B. of the type known from US Pat. No. 2,732,301, also mineral acids, carboxylic acids, z. B. maleic acid. Dichloroacetic acid and salicylic acid and also sulfonic acids and phosphoric acids and a wide variety of dyes, e.g. B. cyanine dyes, including carbocyanine dyes, merocyanine dyes and also diarylmethane, thiazine, azine, oxazine, xanthene, phthalein, acridine, azo and Anthraquinone dyes and mixtures of the individual sensitizers.

Preferably, for the production of an electrophotographic recording material according to Invention as sensitizing dyes pyrylium salts, Selenapyrylium salts and / or TMapyrynum salts and cyanine dyes, including carbocyanine dyes, used

Used as a sensitizer in the manufacture of an electrophotographic recording material according to the invention is used, it has proven to be useful to combine the sensitizer with the binder and to mix the photoconductor and, if necessary, with a solvent, so that after the

wear the coating mass of the sensitizer evenly distributed in the photoconductive layer is present. Of course, the sensitizer can also be used by other customary known methods Can be applied. The use of sensitizers for the production of a recording material according to the invention is not absolutely necessary per se.

However, since the addition of relatively small amounts of sensitizer leads to a considerable increase Sensitizers are usually used.

The concentration of the sensitizer used in the individual case can be very different. The in In individual cases, the optimum concentration depends somewhat on the photoconductor used and the sensitizer himself off.

It has proven to be useful to use the sensitizer in concentrations of about 0.0001 to about 30 percent by weight, based on the weight of the photoconductive layer to be used. Preferably the sensitizer is used in concentrations of about 0.005 to about 5.0 weight percent based on the weight of the photoconductive layer is used.

Customary organic solvents can be used to produce the photoconductive layers are, for example benzene, toluene, acetone, 2-butanone, chlorinated hydrocarbons such as methylene chloride and ethylene chloride, ethers such as tetrahydrofuran, and mixtures of such solvents.

The concentration of the photoconductor in the photoconductive layer should preferably be at least 1 percent by weight be. The upper concentration limit can be very different. So can he Proportion of the photoconductive layer on the photoconductor be about 1 to about 99 percent by weight. Preferably the proportion of the photoconductive layer on the photoconductor is about 10 to about 60 percent by weight.

The thickness of the photoconductive layer on the support can vary widely. It has proven to be expedient to add a layer thickness of, measured wet, about 0.0025 to about 0.025 cm use. The electrophotographic recording materials according to the invention preferably comprise photoconductive layers with layer thicknesses of about 0.005 to about 0.015 cm, measured before drying, although advantageously also recording materials with photoconductive Layers of other layer thicknesses can be used.

The support of the electrophotographic recording material according to the invention can consist of one of the conventional supports which are used for the production of electrophotographic recording materials. Suitable, electrically conductive layers are, for example, paper (at a relative humidity of above 20%); Almnmium paper lambs; Metal foils, e.g. aluminum and zinc foils, metal plates, e.g. B. made of aluminum, copper, zinc, brass, and galvanized plates or substrates made of conventional foils, e.g. B. made of cellulose acetate, polyethylene terephthalate or polystyrene on soft metal layers of z. B. silver, nickel and aluminum vapor-deposited sin <L

Particularly advantageous conductive layers have been found to be those produced by them can be that on a suitable support made of, for example, polyethylene terephthalate a

Layer is applied from a dispersion of a semiconductor in a resin. A special one An advantageous conductive layer may, for example, be made from the sodium salt of a carboxy-lactone of maleic anhydride and a vinyl acetate polymer and copper (I) iodide. Such Conductive layers and processes for their production are from U.S. Patent 3,007,901. 3,245,833 and 3,267,807 are known.

The electrophotographic recording material according to the invention can be used in the context of the usual known electrophotographic methods can be used. One such method is, for example the so-called xerographic process. This process uses an electrophotographic Recording material stored in the dark and uniformly when used by means of a corona discharge electrostatically charged. The charge is due to the insulating properties of the photoconductive layer in the dark, d. H. because of the low conductivity of the layer in the dark. The electrostatic charge on the surface of the photoconductive layer is then selectively derived by imagewise exposure of the layer. The exposure can, for example, according to the conventional contact copying methods or by projecting an image with a lens or by reflex or Bireflex methods take place. In all cases it will creates a latent electrostatic image on the photoconductive layer upon exposure.

The electrostatic latent image produced in the manner described can then be developed directly or transferred to an image receiving layer and developed there, either the charged or non-charged areas can be made visible by electrostatically applying to the layers responsive particles of optical density are applied. The ones used for development Electrostatically responsive particles can be used in the form of dust or powder come. Preferably, developer or so-called toner particles are used, which consist of a Pigment in a resinous carrier or binder. The Developing an electrostatic latent image by applying a toner with a magnetic brush proven. Development processes in which magnetic brushes are used to apply the toner are, for example, from U.S. Patents 2,786,439, 2,786,440, 2,876,441, 2,811,465. 2,874,063, 2984163, 3,040,704, 3,117,884 and American Reissue Patent 25,779.

The development of the latent electrostatic images can also be done with the help of liquid developers take place. In liquid developers, the developer particles are in an electrically insulating liquid, d. H. an electrically insulating, liquid carrier, applied. Development process, in which liquid developers are used are for example from U.S. Pat. No. 2,297,691 and Australian Patent 212,315.

In the dry development process, preference is given to Developer or toner particles used in which a component is made from a low Temperatures melting shark? consists. By * S When the applied particles are heated, they are brought to the cup and thereby firmly on the photoconductive layer anchored. The latent electrostatic image transferred to an image receiving material and developed here in a corresponding manner or else the image developed by means of a developer or toner can be transferred to an image receiving material and are fixed here by melting the toner or developer particles. Such fixing methods are for example from IJSA. Patents 2,297,691 and 2,551,582 and the journal "RCA Review", Vol. 15 (1954), pp. 469 to 484, known.

The electrophotographic recording material of the invention can be used in various ways be modified. Thus, the recording material according to the invention can be a single or multiple photoconductive Have layers, and the support may be transparent or non-transparent. Of furthermore, when a plurality of photoconductive layers are used, these can optionally lie one on top of the other or by insulating layers or layers made of another photoconductive material be separated from each other. The recording material can optionally also have a top layer and / or have special sensitizing layers.

It is also possible to change the position of the substrate and the electrically conductive layer, by applying a photoconductive layer to the support and the exposed side of the Support or the exposed or coated side of the photoconductive layer with an electrically conductive layer is coated.

The following examples are intended to illustrate the invention in more detail.

example 1

1.5 g of a terephthalic acid - 4,4 '- isopropylidenebis-phenoxyethyl-trimethylene mixed polyester binder, 0.5 g 4,4'-benzylidine - bis - (N, N - diethylm-toluidine) as a photoconductor and 0.04 g of 2.4- (4-ethoxypheny 1) - 6 - (4- η - amyloxyslyrol) - pyrylium fluoroborate As a sensitizer, 15.6 g of methylene chloride were stirred into the solvent for one hour dissolved within one hour at room temperature.

The resulting solution was then measured by hand in a layer thickness of, wet, 0.010 cm to one electrically conductive layer on a cellulose acetate film support applied. The electrically conductive layer consisted of the sodium salt of a carboxy ester lactone of the type known from U.S. Patent 3,120,028. The coating block was doing it kept at a temperature of 32 ° C. After the photoconductive layer had dried, the The recording material is charged under a positive corona discharge until the surface tension, measured with an electrometer, reached about 600 V.

The recording material was then displayed on a gray scale with graduated increments of density exposed to a 3000 ° K tungsten lamp.

As a result of the exposure, the surface tension of the photoconductive layer was reduced under each step of the gray scale from the original voltage V ₀ to a lower voltage V corresponding to the amount of light applied to each step in lux or seconds-meter candles.

The results of the measurements were plotted in the form of a diagram in which the surface

voltage V was plotted against the logarithm of exposure for each step.

The shoulder sensitivity, hereinafter referred to as sensitivity A, is the numerical expression of 10 * multiplied by the reciprocal value of the exposure in seconds meter candles, which is required to reduce the surface tension of 600 V by 100 V.

The sensitivity in the toe area of the blackening curve, hereinafter referred to as sensitivity B , is the numerical expression of 10 ⁴ multiplied by the reciprocal value of the exposure in seconds meter candles, which is required to reduce the surface tension from 600 V to 100 V.

In the case of this example, the sensitivity B was 180.

Correspondingly favorable results were obtained with both positive and negative charging, if 0.5 g of bis (4-diathyiamino) -I, l, l-triphynylethane or 0.5 g of bis (4-diethylamino) -tetraphenylmethane as a photoconductor instead of 4,4'-benzylidine-bis- (N, N-diethyl-m-toluidine) were used. *

Example 2

The procedure described in Example 1 was repeated, but this time an isophthalic acid-4,4 ' - isopropylidene - bis - phenoxyethyl - telramethylene mixed polyester as a binder instead of the terephthalic acid - 4,4 '- isopropylidene - bis - phenoxyethyltrimethylene mixed polyester was used.

In the present case, the sensitivity B was 250 when the recording material was positively charged.

Similar results were obtained with both positive and negative charging, when 0.5 g of bis- (4-diethylamino) -l, l, l-triphenylethane or 0.5 g of bis- (4-diethylamino) -tetraphenylmethane as a photoconductor instead of 4,4'-benzylidene-bis- (N, N-diethyl-m-toluidine) were used.

Example 3
(Comparative example)

The procedure described in Example 1 was repeated, this time using a terephthalic acid as the binder - 4,4 '- isopropylidene - bis - phenoxyäthyläthylen-Mischpolyesler was used. With this one The binder was not a binder used according to the invention, since the alkylene radical (i.e. Z) had only 2 carbon atoms,

In this case, a sensitivity B of only 128 was determined for positive charging.

Examples t to 8

The procedure described in Example 1 was repeated with various other binders. 1.5 g of the binders listed in Table II below were used in each case. Excellent sensitivities B were found in all cases.

10 example
No. Tables (Positive 100-V-)
sensitivity
B. > S 4
5
20th
6th
7th
3 "
8th binder 180
180
200
200
200 Terephthalic acid-4,4'-iso-
propylidene-bis-phenoxy-
ethyl tetramethylene
Mixed polyester
Terephthalic acid-4,4'-iso-
propylidcn-bis-phenoxy-
ethyl pentamethylene
Mixed polyester
Terephthalic iure-4,4'-iso-
propylidene-bis-phenoxy-
ethyl-oxydiethyl mixed
polyester
Isophthalic acid-4,4'-isopro-
pylidene-bis-phenoxyethyl
ethylene mixed polyester
Isophthalic acid-4,4'-isopro-
pylidene-bis-phenoxyethyl
neopenty! mixed polyester

Example 9

Further recording materials as described in Examples 1 and 4 to 8 were produced. In a dark room, the photoconductive layers were applied to a corona discharge using a Voltage of about + 600 V charged.

The layers were then with a slide (with transparent and non-transparent areas) covered, whereupon the recording materials with

, 5 a daylight lamp with an exposure level of exposed for about 805 lux for 12 hours.

The electrostatic latent images thereby obtained were then cascade developed in a conventional manner developed, whereby a mixture of negatively charged, black, thermoplastic clay particles and glass beads were used. In all cases they were excellent Reproductions of the slide obtained.

Claims (2)

Patent claims: 1. Electrophotographic recording material consisting of a support and at least one photoconductive layer with an alkylidene-bis-aryloxyalkyl-alkylene mixed polyester as a binder, a photoconductor dispersed therein and optionally a sensitizing dye, characterized in that the polyester consists of a terephthalic acid-alkylidene to bis-aryloxyalkyl-alkylene-mixed polyester with 3 to 10 carbon atoms in the alkylene radical or an isophthalic acid-alkylidene-bis-aryloxyalkylalkylene mixed polyester with 2 to 10 carbon atoms in the alkylene radical. 2. Electrophotographic recording material according to claim 1, characterized in that that it contains a linear mixed polyester with arbitrarily repeating units of the formulas CH -CH ₂ -CH ₂ -O Q-CH ₃ -CH ₂ -OC c-o- 0 D ' Il -Ζ' — Ο — C- E ' CH ₂ -CH ₂ -O O D ' 0-CH ₂ -CH ₂ -OC where means a) a straight or branched, optionally substituted alkylene radical with 3 to 10 carbon atoms, b) an oxydialkylene or thiodialkylene rest of the formula - <CH ₂ ) - where X is an oxygen or sulfur atom and η and m are an integer between 2 and 7. c) an alkylene bis (oxyalkylene) or alkylene bis (thioalkylcn) radical of the formula - (CH ₂ ) —X ~ (CH ₂ ) —X - (CH ₂ ) - where X is an oxygen or Sulfur atom and ρ, q and r is an integer between 2 and 6, or d) a cycloalkylene radical of the formula C- / where Q is the atoms required to complete a cycloalkylene radical with 3 to 6 carbon atoms and u and υ are an integer between 0 and 5, a) a straight or branched chain, optionally substituted alkyl radicals having 2 to 10 carbon atoms, b) an oxydialkylene or thiodialkylene radical of the formula - (CH ₂ IX where X is an oxygen or sulfur atom and η and m is an integer between 2 and 7, c) an alkylene - bis - (oxyalkylene) - or alkylene-bis- (thioalkylene) radical of the formula - (CH ₂ ^ X- (CH ₂ ^ -X- (CH ₂ ) T-