DE1943386C - Electrophotographic recording material - Google Patents

Description

The invention relates to an electrophotographic The invention is the surprising finding

Recording material from a layer support, based on the stated object in particular at least one of a non-polymeric organic photo is advantageously soluble in that for the manufacture conductor, a halogenated polyethylene as a binder 55 position of the photoconductive layer a non-polymer and optionally a sensitizing dye rer, organic photoconductor used and a halo having photoconductive layer as well as counter-containing polymeric binders are precisely defined if necessary intermediate and / or top layers. Structure is incorporated.

Electrophotographic recording materials The invention relates to an electrophoto

with binder-containing photoconductive layers 60 graphic recording material from one layer are known to use such recording media, at least one non-polymeric or nungsmatcrialien for the implementation of electro- ganischen photoconductors, a halogenated Polyäthylei Photographic processes are known to be used as a binder and optionally a sensitizer the photoconductive layers containing latent electrostatic dye-containing photoconductive slide Images generated, whereupon these become visible repro- 65 as well as optionally intermediate and / or deck ductions are developed. There are already layers, which is characterized by the fact that it is urgent electrophotographic recording materials halogenated polyethylene with a halogen content known whose photoconductive layers contain an inert, of at least 50 percent by weight.

It was found that the electrophotographic usable halogenated polyethylene can be used in

Kichnungsmaterials according to the invention take place in a known way Licher, for. B. in such a way that

a solution of a low-density polyethylene in

have increased photosensitivity. A remarkable solvent treated with halogen for so long

increased electrical sensitivity, d. H. 5 becomes until the halogen content is the desired value

the sensitivity in the slack area of the black has reached. The isolation of the obtained halogen

tion curve and shoulder sensitivity occurs nated polyethylene can according to the usual known

take place in particular with regard to the so-called standard Η method.

and D curve on in comparison with the electrical The in the electrophotographic recording sensitivity of known, using io material according to the invention as a binder of conventional known polymeric binders produced halogenated polyethylene are used to increase electrophotographic recording materials. the electrophotographic sensitivity of the various types of increases in the electrical sensitivity of various photoconductors. A special precaution can be demonstrated when the electrophotographic photoconductors have proven to be part of the photoconductors, which consist of orschen recording materials a suitable electrical compounds, which compared to Irish potential of z. B. 500 to 600 volts gave light an electrophotographic sensitivity and then the relative sensitivity in such a way and for the formation of practically transparent is determined that the reciprocal value of the reduction of the potential of the surface charge for the Ver electrophotographic recording materials are capable of when they are in In the form of coating 100 volts (shoulder sensitivity) or applied to a transparent layer carrier for mass reduction of the potential to 100 volts (becoming sensitive. Organic properties in the sagging area of the blackening curve have proven to be particularly advantageous) Amin «type required exposure is determined. The proven. Such organic photoconductors have a restriction of the surface potential to 100 volts as a common structural feature that the minimum or lower required exposure value is at least one amino group. Typical suitable, specifically of importance than those for the development of a latent image of are e.g. B. Arylamine compounds, namely (1) Diaryl importance. The relative sensitivity of amines, for example diphenylamine, dinaphthylamine, 100 volts is a measure of the ability of the N, N'-diphenylbenzidine, N _T phenyl-1-naphthyl electrophotographic recording material to amine, N-phenyl-2-naphthylamine, N, N '- diphenyl production and to that extent also for development or ρ - phenylenediamine, 2 - carboxy - 5 - chloro - 4'- methane-wide use of the latent image. Entoxydiphenylamine, ρ - anilinophenol, N, N' - contains the electrophotographic Recording material 2 - naphthyl - ρ - phenylenediamine and the diaryl binder described in the no photoconductor, but only a common known US Pat. B. non-polymeric tri-100 volts or below, so that for such an arylamine, for example triphenylamine, Ν, Ν, Ν ', Ν'-drawing material no sensitivity can be determined tetraphenyl - m - phenylenediamine, 4 - acetyltriphenylist. If, on the other hand, amine, 4-hexanoyltriphenylamine, 4-lauroyltrialine is incorporated into an organic photoconductor, phenylamine, 4-hexyltriphenylamine, 4-dodecyltrialine lowers the surface potential of the resulting electrophenylamine, 4,4′-bis (diphenylamino) -benzile , photographic recording material usually 4,4 '- bis - (diphenylamino) - benzophenone and the like. White below 100 volts, so that a clear determination tere suitable photoconductors of the amine type are z. B. the sensitivity is possible. As already mentioned, described in US Pat. No. 3 180 730,
It was found that the electrophotographic recordings have also proven to be suitable photoconductive, spectral drawing materials according to the invention, higher 45 trally sensitizable compounds, as they have sensitivities than known ones, e.g. B. in U.S. Patent 3,265,496 using conventional known polymeric binders, e.g. B. non-polymeric photoconductors of all manufactured recording materials, common formula:

For the production of the electrophotographic recording materials the invention is expediently 5 °

at least 50 percent by weight halogen, preferred G - N A Q

I containing 50 to 70 percent by weight of halogen

halogenated polyethylene in a suitable solution A '
medium at room temperature with a non-polymer
organic photoconductor mixed. The obtained be 55 j _n ^ _er means
Layering compound does not need to be heated because

Difficulties in dissolving the binder or in A mononuclear or either condensation coating of the substrate do not exist. Advantageous or linear polynuclear divalent is furthermore that with the coating not maintained aromatic residue, ζ. H. a phenyl, Nuphtliyl-, must be until a conversion of the Bcschichtungs- ^6o Biphcnyl- or Binaphthylrest, or a subslikomponenten has taken place. After intimate mixing of the divalent aromatic radical, the resulting coating material is of the appropriate type, the substituent of which may be present, moderately according to customary known processes, e.g. B. by whirling up from an acyl radical with I to about 6 carbon ^, spraying, with the help of stripping atoms, l. B. an acetyl, propionyl or Bumesser and the like., Applied to an electrically conductive layer 65 tyrylrest, an alkyl radical with I to about 6 carbon carriers. material atoms, e.g. B. a methyl, ethyl, propyl

The production of the in the electrophotographic Auf- or Butylrest, an alkoxy radical with 1 to about

Drawing material according to the invention as a binder 6 carbon atoms, ζ. B. a methoxy, ether

»5

oxy, propoxy or pentoxy radical, or a nitro group,

A 'a mononuclear or either condensed or linear polynuclear monovalent aromatic radical, e.g. B. a phenyl, naphthyl or biphenyl radical, or a substituted monovalent aromatic radical of the specified type, the substituent of which can consist of, for. B. an acyl radical having 1 to about 6 carbon atoms, e.g. B. an acetyl, propionyl or butyryl radical, an alkyl radical having 1 to about 6 carbon atoms, e.g. B. a methyl, ethyl, propyl or butyl radical, an alkoxy radical having 1 to about 6 carbon atoms, e.g. B. a methoxy, propoxy or pentoxy radical, or a nitro group,

Q is a hydrogen or halogen atom or an aromatic amino radical, e.g. B. an amino radical of the general formula A'NH-, and

ZO

G is hydrogen, mononuclear, or either condensed or linear polynuclear aromatic radical, e.g. B. a phenyl, naphthyl or biphenyl radical, or a substituted one aromatic radical of the specified type, the substituent of which is selected from an alkyl, alkoxy, Acyl or nitro group.

Polyarylalkane photoconductors have proven to be particularly advantageous, as they are, for. B. U.S. Patent 3,274,000 and in French patent 1,383,461. Typical such Photoconductors are e.g. B. leuco bases of diaryl or triarylmethane dye salts, 1,1,1-triarylalkanes, whose alkane component has at least 2 carbon atoms and tetraarylmethanes with a substituted one Amine group in at least one aryl radical bonded to the alkane component, as well as methane derivatives the latter two classes of photoconductors that are not leuco bases.

Particularly preferred polyarylalkane photoconductors are those of the general formula:

substitutes are z. B. to such the general formula:

—N

in which the substituents L are either individually alkyl radicals usually having 1 to 8 carbon atoms or hydrogen atoms or aryl radicals, or together those for the formation of a heterocyclic amino radical with usually 5 to 6 ring atoms, e.g. B. a morpholino, pyridyl or pyrryl radical required Atoms.

At least one of the substituents D, E or M is preferably a p-dialkylaminophenyl radical.

If J stands for an alkyl radical, this is usually the case an alkyl radical having 1 to 7 carbon atoms.

Typical suitable polyarylalkane photoconductors are e.g. B. in the. compounds listed below in Table A.

Table A

45

D.
J —CE

in which D, E and M are an aryl radical and J is a hydrogen atom, an alkyl radical or an aryl radical, wherein at least one of the substituents D, E and M contains an amino substituent. The at that Aryl radicals bonded to the central carbon atom are preferably phenyl radicals, although naphthyl radicals are also present have proven suitable.

The aryl radicals of the type indicated can optionally be substituted in the ortho, meta or para position be e.g. B. by alkyl or alkoxy groups with usually 1 to 8 carbon atoms or by Hydroxy radicals or halogen atoms. As particularly beneficial orthosubstituted phenyl radicals have been found.

The aryl radicals of the specified type can also be linked to one another or cyclized, e.g. More colorful Formation of a fluorene residue.

In the case of the amino

connection
No. Name of the photoconductor 1 4,4'-Benzylidin-bis- (N, N-diethyl- m-toluidine) 2 4 ', 4 "-Diamino-4-dimethyIamino- 2 ', 2 "-dimethyltriphenylmethane 3 4 ', 4 "-bis- (diethylamino) -2,6-dichloro- 2 ', 2 "-dimethyltriphenylmethane 4th 4 '4 "- bis - (diethylamino - 2.2" - di- methyl) -diphenylnaphthylmethane 5 2 \ 2 "-DimethyI-4,4 ', 4" -tris- (dimethyl- amino) triphenylmethane 6th 4 ', 4 "-Bis- (diethylamino) -4-dimethyl- amino-2 ', 2 "-dimethyltriphenylmethane 7th 4 ', 4 "-Bis- (diethylamino) -2-chloro- 2 ', 2 "-dimethyl-4-dimethyIamino- triphenylmethane 8th 4 ', 4 "-Bis- (diethylamino) -4-dimethyl- amino-2,2 ', 2 "-trimethyltriphenyl- methane 9 4 ', 4 "-Bis- (dimethylamino) -2-chloro- 2 ', 2 "-dimethyltriphenylmethane 10 4 ', 4 "-Bis- (dimethylamino) -2', 2" -di- methyl-4-methoxy triphenyl methane 11th Bis (4-diethylamino) -l, l, l-triphenyl- ethane 12th Bis- (4-diethylamino) -tetraphenyl- methane 13th 4 ', 4 "-Bis- (benzylethylamino) - 2 ', 2 "-dimethyltriphenylmethane 14th 4 ', 4 "-bis- (diethylamino) -2', 2" -di- ethoxytriphenylmethane 15th 4,4'-bis (dimethylamino) -l, l, l-tri- phenylethane 16 l- (4-N, N-dimethylaminophenyl) - 1,1-diphenylethane 17th 4-dimethylaminotetraphenylmethane 18th 4-diethylaminotetraphenylmethane

As suitable organic photoconductors used in electrophotographic Recording material after the

Invention can be used in combination with the "sensitizers" given below also non-ionic cycloheptenyl compounds have been found, as they are, for. B. in the Belgian patent 708 638 are described, also N, N-bicarbazy! E and tetrasubstituted hydrazines, 3,3'-bis-1,5-diaryl-pyrazolines, also triarylamines in which at least one aryl radical is substituted by a vinyl radical or a vinylene radical having at least one active hydrogen-containing group, e.g. B. p-Diphenylaminocinnamic acid, also triarylamines which are substituted by an active hydrogen-containing group, z. B. 4-carboxytriphenylamine, as well as those in the compounds described in Australian Patent Specification 248,402.

Organometallic compounds have also proven to be suitable, sensitizable organic photoconductors which are organic derivatives of metals from groups IVa and Va of the periodic table, proven, e.g. B. organometallic compounds with at least one bonded to the metal atom Aminoaryl radical as z. B. in the Belgian patent 717,265 are described. Typical suitable organometallic compounds are z. B. the triphenyl-p-dialkylaminophenyl derivatives of silicon, germanium, tin and lead and the tri-p-dialkylaminophenyl derivatives of arsenic, antimony, phosphorus and bismuth.

The 4-diarylamino-substituted ones have also proven to be suitable photoconductors Chalconies proved. Typical suitable compounds of the specified type are low molecular weight non-polymeric ketones of the general type Formula:

Il ·

CH = CH-CR ₂

in which R ₁ and R ₂ optionally substituted phenyl radicals and especially when R _{2 is} a phenyl radical of the general formula:

in which R ₃ and R _{4 are} aryl radicals, aliphatic radicals having 1 to 12 carbon atoms, e.g. B. alkyl radicals preferably having 1 to 4 carbon atoms, or hydrogen atoms. -

Chalcones of the formula given have proven particularly advantageous in which R ₁ denotes optionally substituted phenyl radicals and R ₈ denotes a diphenylaminophenyl, dimethylaminophenyl or phenyl radical.

The electrophotographic recording materials according to the invention are, as already mentioned, optionally to improve the electrophotographic Sensitivity with the help of vop sensitizers, which in sufficient to increase sensitivity Quantities applied are sensitized. As suitable, in combination with the specified Sensitizers which can advantageously be used for photoconductors have a wide variety of sensitizing agents Connections proven, e.g. B. pyrylium, thiapyrylium and selenapyrylium dye salts, such as she z. B. in U.S. Patent 3,250,615, also fluorenes, e.g. B. 7,12-Dioxo-13-dibenzo (a, h) fluorene, 5.10 - Dioxo - 4a, ll - diazabenzo (b) fluorene and 3.13 - Dioxo - 7 - oxadibenzo (b, g) Nuoren, also aromatic nitro compounds of the type described in US Pat. No. 2,610,120, Anthrones such as B. U.S. Patent

is 2,670,284, quinones such as are described e.g. B. in U.S. Pat. No. 2,670,286, benzophenones such as are described e.g. B. U.S. Patent 2,670,287 are described and thiazoles, as z. B. in the USA patent specification 2,732,301

ao are written, also mineral acids, carboxylic acids, for example maleic acid, dichloroacetic acid and salicylic acid, also sulfonic and phosphoric acids, and various dyes, e.g. B. cyanine, carbocyanine, Merocyanine, diarylmethane thiazine, azine,

as oxazine, xanthene, phthalein, acridine, azo and Anthraquinone dyes and mixtures thereof. Pyrylium-, Selenapyrylium and Thiapyryiiumsalze as well as carbocyanine dyes proved.

Are used to produce the electrophotographic recording materials according to the invention Coating materials used which, in addition to the binder and the organic photoconductor, contain a sensitizer contain, it has proven to be useful to use the sensitizer in one to increase sensitivity to mix the required amount intimately with the coating material in such a way that that the sensitizer in the photoconductive layer coated on a support in a more uniform manner Distribution is available. For the production of the electrophotographic recording materials according to In the invention, however, the sensitizers can be added to the coating compositions or the photoconductive layers can also be incorporated by other customary known methods.

The layers containing the photoconductors of the electrophotographic However, as already mentioned, recording materials according to the invention must be used for To achieve sufficient photoconductivity, do not contain sensitizers. However, it has been found to be beneficial proved to incorporate sensitizers into such layers, since it has been shown that already comparatively small amounts of sensitizers significantly improve the sensitivity of the lead photoconductive layers.

The sensitizers can be incorporated into the photoconductive layers containing the photoconductor in a wide variety of amounts to increase sensitivity. The optimal concentrations of sensitizer depend on several factors, e.g. B. the type of photoconductor and sensitizer used. As a rule, a noticeable increase in sensitivity is achieved when the sensitizer is used in concentrations of about 0.0001 to 30 percent by weight, suitably from about 0.005 to 5.0 percent by weight, based on the total weight of the coating composition.
For the production of the specified binders

209633/378

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9 10

The coating compositions containing the static charge can be provided by it

A wide variety of solvents can be used. Ty- is exposed to a corona discharge in the "manner

Pische suitable organic solvents are, for. B. that on the entire surface of the photoconductive

Benzene, toluene, acetone, 2-butanone, chlorinated carbon layer a uniform charge is created. This Hydrogen, for example methylene chloride, ethylene 5 surface charge is from the photoconductive

chloride and the like, furthermore ether, for example tetra-layer withheld, because this is in the dark

hydrofuran, or mixtures of such solvents co-imprinted insulating properties, d. H. only a minor one

tel. Has conductivity. Those on the surface of the

The photoconductive layer containing the specified binders is formed electrostatic Layering compounds can then charge the photoconductor in reverse from the surface of the layer contain different concentrations. It has been found to be selectively derived by the recording material Proven to be expedient, the photoconductor in a Konzen after a customary known exposure process Tration of at least about 1 percent by weight, is exposed according to the image. The exposure can moved to the coating compound to use. The z. B. be done according to a contact copying process, The upper limit of the photoconductor concentration can be set by 15 by lens projection of an image, with the help of the intended use of the electro-called reflex or bireflex process and the like The exposure is in the photoconductive layer very much on the photographic recording material be divorced. Typically, a photoconductor has a latent electrostatic image; H. an electroconcentration of about 1 to 99 percent by weight, static charge pattern, is generated due to the on attracted light energy to the coating material as expediently also the photoconductive layer grasslands. The photoconductor is preferably in the area where the electrostatic charge is located in the exposed areas Layering mass in a concentration of about 10 from the layer surface depending on the up to 60 percent by weight. Intensity of the incident exposure dissipated

For the production of the electrophotographic recording. Drawing material according to the invention can be used in the exposed electrophotographic

photoconductive layer on the support in the recording material generated latent charge patterns

different strengths can be applied. Usually it is then developed or applied to the surface of one

The layer receiving material measured in the moist state has transferred and developed there,

Thicknesses from about 0.025 to 0.25 mm (0.001 to 0.01 inch). Development is done with the help of an electrostatic

preferably from about 0.05 to 0.23 mm (0.002 to 30 attractable optically dense particles containing

0.006 inch) has been found to be useful. The specified, winder in such a way that either the loaded

The layer or uncharged areas measured before the layers dry are made visible,

However, the thickness may vary depending on the intended use of the electrostatically attractable developer particles

Electrophotographic records to be produced can be in the form of a dust or powder

voltage material vary within wide limits. 35 and usually have what is known as a toner, in

The electrophotographic recording material has a pigment distributed in a resinous carrier. Alien according to the invention can contain the most diverse. Such a toner can contain on the latent electro-known, static image usually used for this purpose according to customary known methods layer support. Typical suitable, to be brought. It has proven to be particularly advantageous such electrically conductive substrates are, for. B. 40 proved the toner after a so-called solid paper with a relative humidity of over 20%> district development process with the help of a magnet to apply laminates made of aluminum and paper, furthermore a brush. Process for forming and on-metal foils, e.g. B. aluminum and zinc foils, also turning suitable magnetic brush toner application metal plates, e.g. B. aluminum, copper, zinc, devices are z. B. in the USA. Patent brass and galvanized plates, as well as evaporated 45 writings 2 786 439, 2786440, 2 786 441, 2 811465, Metal layers, e.g. B. made of nickel or aluminum. 2 874 063, 2 984 163, 3 Ö4ö 7ö4, 3 ii7 884 and ift der

A particularly advantageous electrically conductive reissue patent Re 25 779 is described. Carrier can e.g. B. be produced in such a way that the latent electro-

on a z. B. from a polyethylene terephthalate static baths can also with the help of

Standing carrier material can be developed in a dispersed 50 liquid developer. When using

In the form of a semiconductor-containing resin solution, such liquid developers will

layer is applied. Furthermore, a suitable winder particle can with the help of an electrically insulating

Conductive layer support also made of the sodium salt of the liquid carrier on the one carrying the latent image

a carboxy ester lactone of maleic anhydride on the surface of the exposed recording material

and a vinyl acetate polymer. 55 brought development processes of this type are

Suitable such electrically conductive substrate knows and are z. B. U.S. Patent

and methods of making them conveniently 2,297,691 and in Australian Patent

and use are e.g. Described in U.S. Patent 212,315.

Writings 3 007 901 and 3 267 807. . If the development is carried out with the help of dry The electrophotographic recording materials are carried out, so to produce permanent

alien according to the invention can mostly developers with design to carry out adhesive recordings

used by all known recording material winder particles, one component of which

Anything with photoconductive layers is made of a low-melting resin. Will

electrophotographic processes can be used. a visible with the help of such a developer powder

So they are z. B. heated to carry out a so-called 65 bar made Bfld, the resin is

suitable for a xerographic process in which a molten material or it penetrates into molten

Electrophotographic imaging stored in the dark is incorporated into the developed recording material

drawing material with a uniform electrical or is deposited on the same, so that it is on the

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11 12

Surface of the photoconductive layer, permanent example 1

adheres. There were 1.5 g of a chlorinated polyethylene

Furthermore, as already mentioned, the charge image produced on the photoconductive layer with a chlorine content of 53.6 percent by weight or by standing binder, 0.5 g of an image made visible from 4,4'-benzy developer powder can be applied to a 5 - to - (N, N - diethyl - m - toluidine) existing Receiving material from e.g. B. paper and transferred to photoconductor and 0.02 g of one of 2,4- (4-ethoxy then the final copy by developing phenyl) - 6 - (4 - η - amyloxystyryl) - pyrylium fluoro- and melting the developer resin or sensitizer consisting of borate in 15.6 g of methylene melt of the transferred developer resin in chloride by stirring the solids in the for 1 hour can be produced in a permanent manner. Method of an- io solvent dissolved at room temperature. The given types are known and are e.g. B. in the holding solution was hand on one on one U.S. Patents 2,297,691 and 2,551,582 and cellulose acetate film arranged electrically conductive in "RCA Review", Vol. 15 (1954), pp. 469 to 484, a layer made from the sodium salt of a carboxy ester. lactones as described in U.S. Patent 3,260,706

The electrophotographic recording material is written on in such a way that the alien according to the invention can differ in structure from 0.1 mm (0.004 inch) in thickness when wet. So you can z. B. from an opaque scam. The coating block was kept at a temperature of 32 ° C or a transparent, electrically conductive layer substrate. The resultant electro, to which the photoconductive coating material in photographic recording material is applied, is in the form of a single layer or in the form of several layers for a long time under a positive corona discharge. If the charged layers have photoconductive layers until the drawing materials according to the invention measured several surface potentials measured with the help of an electrometer probe, then these can be arranged next to one another or by layers using a gray scale wedge of a tungsten light source be separated from each other by an insulating material. 25 exposed at 3000 ° K. As a result of the exposure, the substrate and the conductive surface potential of the recording material can be shielded from one another under layers in such a way that each step of the gray wedge from the original potential that on one side of the substrate is a photoconductive V ₀ to a lower potential V, which is more precise Capable layer arranged and on the opposite value of the side of the layer support actually lying on the respective area or on the amount of exposure in meter candle conductive layer an electrically conductive layer depends on seconds, reduced. The results of which is applied. Electrophoto measurements can also be evaluated graphically by, for graphic recording materials according to the invention, the surface potential of each step of the step wedge with a structural structure which is plotted against the logarithm of the exposure to that of the examples 35 given below.

described recording materials differs, the shoulder sensitivity represents the numerical

for the specified or other purposes of use represents the value that is obtained when 10 * with the reci-

Prove to be appropriate or particularly advantageous. proken value of the exposure in meter-candle-seconds

A photographic process for the manufacture of those used to degrade 600 volts visible images using an electrical surface potential of around 100 volts is required, photographic recording material after which is multiplied. The sensitivity in the toe invention advantageously comprises the following range of the density curve represents the numerical one Process steps: value that is obtained when 10 * with the reciprocal value of the exposure in meter-candle-seconds

a) mixing a non-polymeric organic "Jf £ J? * ^for reducing the amount 600iVolt forming photoconductor, a solvent, a & nsibili- Oberflachenpotenüals to 100 volts enomemcn .si, crystallizer for the photoconductor and a multiplying of a. __-_. . "Halogenated" polyethylene of the specified type J ** ^m J? ^r indicated as prepared electrophotographic existing binder at Zimm ^ tempe Ratoe Photographic A ^ ^ ofzeic ungsmatenal w. "i a

so positive 100 volt sensitivity in the slack

b) Application of the resulting coating material range of the blackening curve from 105 to.

on a support; Correspondingly advantageous results were obtained

c) Keep drying the electrophotographic obtained if, instead of 4,4'-benzylidine-bis recording material, at a temperature of (N, N-diethyl-m-toluidm) as a photoconductor, 0.5 g of bis (4-di less than 35 ° C; * ^'55 ethylamino) - 1,1,1 - triphenylethane or 0.5 g bis-

. ". , (4 - diethylamino) - tetraphenylmethane use)

d) charging the dried recording material, rials to a potential of at least 550 volts;

e) imagewise exposure of the charged recording material with a light energy pattern from 60. The method described in Example 1 was used actinic radiation as well as repeated with the exception that from the binder

η τ- * _ · κ j u-j d-j: u * ™ - „-, ...,.,», »„ chlorinated polyethylene with different contents

0 Development of what was produced by the Bichtong. The chlorine content of ver

latent soils with the formation of a permanent _wound p _olyäth y _lenc ^ _{6 dic} E ₁ J ^ _der ^ ₁

visible öiiaes. _6y . ^ "" ,, ^ _the positive 100 volt susceptibility

in the sagging area of the blackening curve

The following examples are provided in Table B below to further elaborate the invention

explain. guided

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table B. Chlorinated polyethylene
as a binder Electric
100 volt sensitivity
in the sagging area (7o Cl) the blackening curve 54 90 57 100 57.7 120 60.8 110 62.4 110 64.0 110 69.3 80 25.0 *) 36.0 *) 42.0 *)

*) the binder was insoluble in the coating material and therefore useless for the production of photoconductive layers.

20th

The results show that only the electrophotographic recording materials according to the invention, the photoconductive layers of which contain a chlorinated polyethylene with a chlorine content of over 50%, lead to beneficial results. As opposed to chlorinated polyethylene with a Chlorine content of less than 50 percent by weight due to its low solubility in the coating compounds useless as a binder. The lack of solubility of such polyethylenes was particularly evident in methylene chloride, which is particularly disadvantageous because methylene chloride due to its high volatility, which means that the finished recording materials are heated to evaporate the solvent superfluous, as well as due to its high dissolving power for photoconductors and sensitizers, represents a particularly advantageous solvent.

Example 3

The procedure described in Example 1 was repeated except that as the photoconductor 4,4'-bis (diphenylaminochalcone) and a chlorinated polyethylene with a chlorine content of 62.4% was used. The obtained electrophotographic recording material showed a positive one 100 volt sensitivity in the toe area of the blackening curve of 280. Was that received If the recording material was negatively charged, a correspondingly advantageous negative sensitivity became obtained in the sagging area of the blackening curve.

Example 4

The procedure described in Example 3 was repeated with the exception that as a sensitizer 6 - chloro - Γ - methyl - 1,2 ', 3' - triphenylimidazo- [4,5-b] quinoxalino - 3 '- indolocarboeyanine - ρ - toluenesulfonate was used. The obtained electrophotographic Recording material exhibited a positive 100 volt sensitivity in the toe region of Blackening curve from 400.

Example 5 (comparative example)

In order to achieve the advantages to be achieved according to the invention, i. H. when using the polymeric binder To illustrate the type of achievable increase in sensitivity, was after the im. Example 1 using an electrophotographic recording material a commonly known polystyrene prepared as a binder. The recording material obtained had a positive 100-volt sensitivity in the toe area of the blackening curve of 4.

In a further experiment, according to the example 1 using an electrophotographic recording material made of polyvinyl butyral as a binder. The recording material obtained showed a positive one 100 volt sensitivity in the sagging area of the blackening curve of 32.

Example 6

Following the procedure described in Example 1 using the methods described in Examples 1 to 4 described coating compositions for electrophotographic recording materials. the Surfaces of the photoconductive layers of the recording materials obtained were then in a darkroom with the help of a corona discharge with a potential of about +600 volts. Thereafter, the charged layers were given a pattern of opaque and translucent Covered areas with transparent film, whereupon they are exposed to radiation for 12 seconds an incandescent lamp with an exposure intensity of about 75 meter candles. Then were the electrostatic latent images thus formed are developed in a conventionally known manner by A mixture of negatively charged blacks spread over the surfaces of the layers carrying the latent image thermoplastic toner particles and glass beads. All samples developed were good Reproductions of the original sample.

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Claims (7)

Resin-like binder, in which an organic photo-patent claims: conductor and a sensitizer are uniformly distributed, * "have. At present, such 1. Electrophotographic recording material - photoconductive layers, binder of the various from a layer support, at least one of the most varied types, which have a wide variety of conventional legs non-polymeric organic photoconductors, known organic photoconductor compounds or halogenated polyethylene as a binder and mixtures are incorporated, used. Typical where appropriate Such binders suitable for a sensitizing dye are e.g. B. usual proving photoconductive layer and known polymeric substances, e.g. B. phenolic resins, ketone, if necessary Intermediate and / or top layers, resins, acrylic ester resins, polystyrenes and the like are disadvantageous characterized in that it is one of such binders, however, that it is the light halogenated Polyethylene with a halogen content sensitivity of the photoconductive layers, in of at least 50 percent by weight. 'which they are unable to improve, 2. Recording material according to claim 1, d. i.e. that the photosensitivity of such layers, characterized in that it is a halogenated 15 as it results from its electrical sensitivity erPolyäthylen with a halogen content between 50 are, as a rule practically completely different from the and contains 70 percent by weight. existing organic photoconductors as well as the 3. Recording material according to claim 1, there being dependent any sensitizer present,
characterized in that it is a halogenated from British Patent 964 878 it is bePolyäthylen contains a chlorinated polyethylene. »0 knows, as a binder for organic photoconductors, 4. Recording material according to claim 1, characterized by polyethylene with a comparatively low throughput characterized in that it has a chlorine content as a photoconductor, d. H. with a chlorine content Polyarylalkane with at least one aminoaryl less than about 33% to be used. Such chlorest or a polyethylene substituted with a 4-diarylamino radical usually shift the spectuated one Contains benzylidene acetophenone. 25 central sensitivity of the photographic 5. Recording material according to claim 1, because conductive layers have usable coatings characterized that it is used as a sensitizing compound, but has the disadvantage that it is in the dye a carbocyanine, pyrylium, thiapyry- most solvents are insoluble and therefore Contains hum or selenapyrylium dye. together with a suitable photoconductor for a long time 6. Recording material according to claims 1 to 30 periods of time at higher temperatures, for. B. 15 hours to 5, characterized in that it, based on long or longer to temperatures which are usually the weight of the photoconductive layer, 10 to over 80 ⁰ C, must be heated. The 60 percent by weight of 4,4 '- benzylidene - bis - (N, N - heating, the solubility of such binders diethyl - m - toluidine) or bis - (diphenylamino) - increases, so that when using unheated benzylidene acetophenone and 0.005 up to 5.0% by weight of coating compounds occurring difficulties in percent 2,4 - (ethoxy - phenyl) - 6 - (4 - η - amyl in terms of coating ability and compatibility oxystyryO-pyrylium-fluoborat contains. Furthermore, the heating causes a turn 7. Recording material according to claims 1 setting between the binder and the photobis 5, characterized in that it, based on ladder, so that a reaction to the newly formed Weight of the photoconductive layer, 10 to 40 product-related displacement of the spec-60 Percentage by weight 4,4 '- bis - (diphenylamino- tral sensitivity takes place. The for dissolving derbenzylidenacetophenon) and 0.005 to 5.0 weight-like known binders and for the implementation of percent 6 - chlorine - Γ - methyl -1,2 ', 3' - triphenyl- the same heating required with the photoconductors imidazo - [4,5 - b] - quinoxaline - 3 '- indolcarbo- is, however, disadvantageous in terms of time and money contains. 45 complex. The object of the invention is to provide a highly sensitive electrophotographic recording material indicate that even without heating the to manufacture the photoconductive layer used binder 50 and organic photoconductor in an advantageous manner can be produced.