DE2657918C3 - Use of heterocyclic compounds of a specific structure as photoelectrophoretic particles or sensitizers in electrophoretophotographic processes - Google Patents

Description

(1 * 1

which also as sensitizers to the subject of the invention is the use of

Sensitizing other photoelectrophoretic compounds of the formula: Let particles use.

C = C-ArA C = C- / o ^> N

R ⁴ R ⁵ j ,,, R ⁴ R ⁵ \ _, R ²

in which:

A is an optionally substituted alkylene

resl with 2 to 5 carbon atoms in the alkylene chain;

Ar is an optionally substituted aromatic ring with 6 to 20 ring atoms, the has no further fused-on saturated N-heterocyclic ring;

R ¹ and R ² together represent an optionally substituted alkylene radical having 2 to 5 carbon atoms in the alkylene chain;

Ri, R ",
and R ⁶

individually in each case a hydrogen or halogen atom, a nitro or cyano radical or an alkoxy radical with 1 to 8 carbon atoms, an optionally substituted alkyl radical with 1 up to 8 carbon atoms in the alkyl radical, an optionally substituted phenyl radical, a Carboxy ester radical with 1 to 4 carbon atoms or an amide radical of the following formula:

R ⁷

—CON

R ⁷

in which R ^{7 represents} a hydrogen atom, an optionally substituted phenyl radical or an optionally substituted alkyl radical having 1 to 8 carbon atoms in the alkyl radical;

individually a hydrogen atom, an optionally substituted alkyl radical with 1 to 8 carbon atoms in the alkyl radical or an optionally substituted aromatic ring with 6 to 20 ring carbon atoms and
= i or 2

20th

25th

30th

35

40 45

50

as photoelectrophoretic particles or sensitizers for photoelectrophoretic particles in electrophoretophotographic Procedure.

The optionally substituted aromatic ring represented by Ar may be act carbocyclic or heterocyclic ring. Typical rings that Ar can stand for are for example optionally substituted phenyl, naphthyl and anthryl rings.

R ¹ , R ⁴ , R ⁵ and R ⁶ can have the same or different meanings. If R ¹ , R ⁴ , R ⁵ and R ⁶ stand for halogen atoms, these can for example consist of fluorine, chlorine, bromine or iodine atoms.

If R ^{2 represents} an optionally substituted aromatic ring, this can likewise be an optionally substituted carbocyclic or heterocyclic ring with 6 to 20 ring carbon atoms.

The alkylene group represented by A and the aromatic ring represented by Ar, the ^{alkylene groups represented by R 1} and R ² , the alkyl groups represented by R ¹ , R ⁴ , R ⁵ and R ⁶ and phenyl groups, the phenyl groups and alkyl groups represented ^{by R 7 and} the alkyl radicals and aromatic rings represented by R ² can be substituted by a wide variety of substituents, for example by halogen atoms, nitro and cyano radicals, alkoxy radicals with 1 to 8 carbon atoms, alkyl radicals with 1 to 8 carbon atoms, phenyl radicals, carboxy ester radicals with 1 to 4 carbon atoms or amide radicals of the formula given.

When used in the context of electrophoretophotographic imaging processes the compounds of the formula shown which represent dyes in the customary manner in electrically chargeable Photosensitive particles are incorporated which are spaced between at least two arranged electrodes are brought. Advantageously, the particles are electrical in one insulating carrier used, for example an electrically insulating liquid or an electrically insulating, liquefiable matrix, e.g. B. a thixotropic or heat- and / or solvent-softenable Substance to which the electrodes are placed. The particles between the electrodes are then exposed to the action of an electric field and exposed in an imagewise manner. As a result a radiation-induced change in their charge polarity occurs in the particles, to which the particles move migrate one or the other electrode surface and on at least one of these electrode surfaces produce an image that can be a positive or negative representation of the original artwork.

Surprisingly, the compounds used according to the invention have the further advantageous ones Property that they contain other light-sensitive particles that are produced in the context of electrophoretic RildherstelHmgsverfahren can be used to sensitize chemically.

The compounds used according to the invention clearly differ in their structure from known organic photoconductive substances, for example those that are from US-PS 32 46 983, 35 67 450,36 53 887 and 38 73 312 are known.

In the drawing is a schematic of a typical apparatus for performing an electrophoretophotographic Image production process shown, to carry out the described Connections can be used. The compounds used in the invention are not just especially for performing electrophoretophotographs because of their excellent sensitivity to electric light Suitable for image production processes They also have other advantageous ones

Properties on.

The compounds used according to the invention are high-intensity dyes with an absorption maximum for visible light of a wavelength of more than 410 nm, in particular with an absorption maximum of 420 to 600 nm. This means that the compounds in general be yellow, orange, or purple in color.

The compounds ι ο used according to the invention are furthermore in customary organic solvents largely insoluble or at least poorly soluble, for example in from aliphatic hydrocarbons existing solvents and solvents derived from alkylated aromatic compounds exist. The property is insoluble or largely insoluble in common organic solvents being is particularly advantageous for performing electrophoretophotographic processes in those cases where the particles are in an electrically insulating support, for example a common aliphatic hydrocarbon solvents are dispersed.

The compounds used according to the invention are used as chemical sensitizers for sensitizing of other photoelectrophoretic particles as part of processes for the production of monochrome and polychromatic images are used, they can be used in conventional sensitizer concentrations will. In mixtures with other photoelectrophoretic particles, they can therefore function from sensitizers as well as from photoelectrophoretic particles.

The substituents of the optionally substituted alkylene and alkyl radicals and the optionally substituted aromatic rings and phenyl groups can consist of a wide variety of substituents, which do not affect the electrical sensitivity of the connections to light are as follows listed some typical substituted alkyl and substituted alkylene groups found in a compound of given general formula may exist. The alkyl radicals typically have the Compounds 1 to 8 carbon atoms.

In the following list, "alkyl" stands for both "alkyl" and "alkylene".

a. Alkoxyalkyl groups with a total of 2 to 8
Carbon atoms, e.g. B. ethoxypropyl,
Methoxybutyl and propoxymethyl groups;

b. Aryloxyalkyl groups, e.g. B. Phenoxyäthyl-, Ns ⁿ hthQX ^v meth ^v l- and Phenoxynentvlirmnnptv

c. Aminoalkyl groups, e.g. B. aminobutyl,
Aminoethyl and aminopropyl groups;

d. Hydroxyalkyl groups, e.g. B. hydroxypropyl,
Hydroxyoctyl and hydroxymethyl groups;

e. Aralkyl groups, e.g. B. benzyl, phenethyl and
ω, ω-diphenylalkyl groups;

f. alkylaminoalkyl groups, e.g. B.
Methylaminopropyl, methylaminoethyl groups
as well as dialkylaminoalkyl groups, e.g. B. bo diethylaminoethyl, dimethylaminopropyl and
Propylamino octyl groups;

G. Arylaminoalkyl groups, e.g. B.
Phenylaminoalkyl, diphenylaminoalkyl,
N-phenyl-N-ethylaminopentyl-, b5 N-phenyl-N-ethylaminohexyl- and
Naphthylaminomethyl groups;

H. Nitroalkyl groups, e.g. B. Nitrobutyl, Nitroäthyl und'Nitropentylgruppen; i. Cyanoalkyl groups, e.g. B. cyanopropyl,

Cyanobutyl and cyanoethyl groups; j. Haloalkyl groups, e.g. B. chloromethyl,

Bromopentyl and chlorooctyl groups and k. Alkyl groups through an acyl radical of the are substituted with the following formula:

—C — R

wherein R represents a hydrogen atom or a hydroxy or aryl radical, e.g. B. a phenyl or Naphthyl radical or a short-chain alkyl radical with 1 to 4 carbon atoms, e.g. a methyl, Ethyl or propyl radical or an optionally substituted amino radical, for example one Amino radical that is substituted by two short-chain alkyl radicals or one short-chain alkoxy radical having 1 to 8 carbon atoms, e.g. B. a butoxy or methoxy radical or an aryloxy radical, e.g. B. a phenoxy or naphthoxy radical. The following are typical substituted aromatic ones Rings and substituted phenyl groups indicated. The substituents typically have these aromatic groups have 1 to 3 carbon atoms. In the following list, "aryl" stands for one Phenyl group as well as other typical carbocyclic aryl groups, for example naphthyl and anthryl groups.

a. Alkoxyaryl groups, e.g. B. ethoxyphenyl, methoxyphenyl and propoxynaphthyl groups;

b. Aryloxyaryl groups, e.g. B. phenoxyphenyl, naphthoxyphenyl and phenoxynaphthyl groups;

c. Aminoaryl groups, e.g. B. aminophenyl, aminonaphthyl and aminoanthryl groups;

d. Hydroxyaryl groups, e.g. B. hydroxyphenyl, hydroxynaphthyl and hydroxyanthryl groups;

e. Biphenylyl groups;

f. alkylaminoaryl groups, e.g. B.
Melhylaminophenyl and methylaminonaphthyl groups

as well as dialkylaminoaryl groups, e.g. B.

Diethylaminophenyl and

Dipropylaminophenyl groups; G. Arylamine aryl groups, e.g. B.

Phenylaminophenyl, diphenylaminophenyl, N-phenyl-N-ethylaminophenyl and

Naphthylaminophenyl groups; H. Nitroaryl groups, e.g. B. nitrophenyl,

Nitronaphthyl and nitroanthryl gynine pen: i. Cyanoaryl groups, e.g. B. cyanophenyl,

Cyanonaphthyl and cyanoanthryl groups; j. Haloaryl groups, e.g. B. chlorophenyl,

Bromophenyl and chloronaphthyl groups; k. Alkaryl groups, e.g. B. Tolyl,

Ethylphenyl and propylnaphthyl groups and 1. Aryl groups by an acyl radical of the following Formula are substituted:

Il

—C — R

wherein R stands for a hydrogen atom or a hydroxy radical or a short-chain alkyl radical with 1 to 4 carbon atoms, e.g. a methyl, ethyl, propyl or butyl radical or an aryl radical, e.g. a phenyl or naphthyl radical or a

optionally substituted amino radical, ζ. Β. an amino radical, which is replaced by two short-chain alkyl radicals is substituted or a short-chain alkoxy radical having 1 to 8 carbon atoms, e.g. B. a butoxy or Methoxy radical or an aryloxy radical, e.g. B. phenoxy or naphthoxy.

Particularly advantageous compounds of the general formula I have proven to be compounds which can be represented by the following two formulas II and III:

Ar

(III)

where Ar has the meaning already given, R ⁴ and R ⁵ each represent a hydrogen atom or a cyano radical, where R ⁴ and R ^{5 can have} the same or different meanings and where R ^{2 is} an optionally substituted alkyl radical having 1 to 8 carbon atoms Alkyl radical or has the meaning of an optionally substituted phenyl radical, it being understood that the substituents mentioned above can be considered as substituents

ι ο have been described in detail.

As already stated, the compounds of the formula I and of the formulas II and III are distinguished by high photosensitivity and other advantageous properties, for example excellent

! 5 Color separation in multicolor electrophoretophotographic imaging processes. In particular, they provide yellow, orange and purple-colored images and have a maximum absorption _{wavelength A max} of 420 to 600 nm.

Some typical, advantageous compounds according to the invention are listed in Table I below

Table I.

link
No.

Structural formula of the connection

13th

continuation

Compound No. Structural formula of the compound

N- <O

\ Joiο

CH ₃

CH ₃

CH ₃

CH ₃ O

CN

CN

OCH ₃

CN

12 CN

CN

continuation

link
No.

Structural formula of the connection

13th

14th

OCH ₃

The photoelectrophoretic particles advantageously have an average particle size of 0.01 microns to 20 microns, especially from 0.01 to 5 microns. The particles can be one or more of the Compounds contain or be constructed from these. The particles can also be non-photosensitive Contain components, e.g. one or more electrically insulating polymers, charge control agents, organic and inorganic fillers and additional dyes and / or pigments for changing or enhancement of the hue and physical properties of the particles. In the end the particles can also contain other photosensitive substances, e.g. B. sensitizing Dyes or chemical sensitizers to increase the sensitivity of the particles to activating Change or increase radiation.

The compounds described can thus be used in the context of electrophoretophotographic image production processes can be used as: (1) photoelectrophoretic particles and sensitizers to produce monochrome images, (2) as chemical sensitizers for other photoelectrophoretic ones Particles as part of processes for the production of monochrome images and (3) as photoelectrophoretic ones Particles and / or sensitizers in mixtures of two or more photoelectrophoretic Particles from two or more photoelectrophortic particles for the production of polychromic Pictures.

Although the particles are simply spaced apart in the form of a dry powder between two mutually arranged electrodes can be accommodated and, for example, after from the US-PS 27 58 939 known method can be worked, it is more typical, the particles in one electrically insulating carrier, for example to disperse an electrically insulating liquid or in an electrically insulating, liquefiable matrix, e.g. B. one by the action of heat and / or Solvent-softenable polymeric material or a thixotropic polymeric material. Will be a If the particles are dispersed in an electrically insulating carrier, it has proven to be expedient proved 0.05 to 2.0 parts by weight of the particles for every 10 parts by weight of the electrically insulating carrier material to use.

Typical electrically insulating carriers for the particles are electrically insulating liquids such as Decane, paraffins and kerosene fractions or isopraraffinic liquid hydrocarbons. Suitable carrier liquids are for example also halogenated hydrocarbons, e.g. B. carbon tetrachloride and Trichloromonofluoromethane and a wide variety of alkylated aromatic liquid hydrocarbons, z. B. alkylated benzenes, e.g. B. xylenes and other alkylated aromatic hydrocarbons such as them for example from US-PS 28 99 335 are known.

Typically, the electrically insulating carrier material, regardless of whether it is solid or liquid at room temperature, ie 22 ° C., has a resistance of greater than 10 ⁹ μm / cm, preferably greater than 10 ¹² ohm / cm.

If the photoelectrophoretic particles are used in a carrier, the to be produced can Suspension, the various other conventional known additives are incorporated, for example conventionally known charge control agents to improve the uniformity of the charge polarity of the particles to enhance.

In addition to charge control agents, the suspensions can also contain a wide variety of polymeric materials Binders are added, for example naturally occurring, semi-synthetic or fully synthetic Resins which can be dispersed or dissolved in the vehicle and used as fixing agents for the to be manufactured Can serve images generated on one of the two spaced electrodes will.

The use of the particles which can be used according to the invention is intended below with reference to the drawing will be explained in more detail.

The device shown in the drawing has a transparent electrode 1, which by means of two Rubber drive rollers 10 can be moved in the direction of the arrow. The electrode 1 can consist of one layer an optically transparent material, for example made of glass or an electrically insulating, transparent polymeric substrate, e.g. B. from polyethylene terephthalate, the one with a comparatively thin, optically transparent, conductive layer, is coated for example from tin oxide or nickel. If necessary, depending on what is used in the individual case The type of imaging process may be the

Surface of layer 1 is a so-called »dark charge exchange material« have, for example consisting of a solid solution of an electrically insulating polymer and 2,4,7-trinitro-9-fluorenone, as is known from BE-PS 8 23 351, for example

The electrode 1 is in pressure contact with a second electrode 5 in the form of a roller, which as Counter electrode to electrode 1 is used and enables the establishment of an electric field! N Typically, the electrode 5 has a thin, electrically insulating layer 6 on its upper side on. The electrode 5 is connected to the voltage source 15 via a switch 7. The other side of the Voltage source 15 is connected to electrode 1 so that when exposure occurs. Switch 5 can be closed and an electric field acts on the electrically photosensitive particles 4, the are located between electrodes 1 and 5. Typically, the particles 4 are electrical in one insulating carrier material of the type described pre-dispersed.

The particles 4 can thereby be brought between the electrodes 1 and 5 that before Carrying out the method either on one or on both surfaces of the electrodes 1 and 5 particles be applied. On the other hand, however, it is also possible to remove the particles 4 during the image production process to inject between electrodes 1 and 5.

In the device shown in the drawing, the exposure of the particles 4 takes place by means of a Exposure system consisting of: the light source 8, an image original 11, for example a photographic one Slide, a lens system 12 and optionally one or more necessary or advantageous radiation filters 13, for example color filters, through which the particles 4 with activating Radiation are exposed in accordance with the original image 11.

Although in the device shown the electrode 1 for activating radiation from the light source 8 is transparent, it is also possible to close the particles 4 in the gap 21 between the electrodes 1 and 5 expose so that none of the electrodes 1 or 5 need to be transparent. In such a device (which is not shown in the drawing) the light source 8 and the lens system 12 are arranged in such a way that that the particles 4 in the gap 21 between the electrodes 1 and 5 are exposed.

As shown in the drawing, the electrode 5 consists of a roller electrode with a conductive core 14, which is connected to the voltage source 15. The core 14 is in turn with a Layer of an insulating material 6, for example a barite paper covered. The insulating Material 6 prevents or at least reduces that the electrically photosensitive particles 4 subject to a radiation-induced change in charge upon contact with the electrode 5. As a result the electrode 5 can also be referred to as a so-called "blocking electrode", as it is in Is also often referred to in the context of conventional electrophoretophotographic image production processes.

Although the electrode 5 in the case of the drawing has the form of a roller electrode and the electrical h ^r, de 1 of a flat movable plate-like electrode is, the electrodes can nevertheless also have other shapes, such as are customary in electrophoretic imaging process. For example, it is possible for one or both of the electrodes to be in the form of ribbon-shaped electrodes or to consist of rotating drum electrodes or plate electrodes. In general, electrodes 1 and 5 are positioned with respect to one another so that they are in pressure contact with one another or, when the imaging process is being carried out, very close together, that is to say are spaced apart from one another by less than 50 microns. If the particles 4 are simply dispersed in an air gap between the electrodes 1 and 5 or in a carrier, for example in the form of a layer of a material that can be softened by the action of heat or in the form of a liquefiable material that is applied in the form of a separate layer on the electrode 1 and / or the electrode 5 is applied, these electrodes can also have a distance of more than 50 microns from one another during the imaging process.

The strength of the electric field created between the electrodes 1 and 5 generated can be very different. However, it has been shown that in general an optimal Image density and optimal image resolution are obtained when the field strength is as high as possible, without an electrical breakdown of the carrier riedium occurring in the electrode gap. Will for example, as electrically insulating liquids, isoparaffinic hydrocarbons as carriers in a device as shown in the drawing is used, the voltage applied to the Electrodes 1 and 5, typically 100 volts to 4 kilovolts or more.

As already explained, the production of the image is the result of a combined action of activating agents Radiation and electric field on the particles 4 between the electrodes 1 and 5. Typically to achieve optimal results, the application of the electric field and the exposure are carried out with activating radiation at the same time. By coordinating the various process parameters with one another, for example the field strength, the intensity of the activating radiation, by adding suitable photosensitive additives, e.g. B. by adding a persistent photoconductive substance, however, it is also possible to vary the timing of exposure and application of the electric field, namely such that exposure and application of the field can take place one after the other.

The particles 4 located between the electrodes 1 and 5 have an electrostatic charge polarity on, which is either the result of a triboelectric reaction of the particles or the result that the Particles react with the carrier material in which they are dispersed.

Image resolution occurs when an electrophoretophotographic process is carried out as in FIG Drawing shown as a result of the combined application of an electric field and activating Radiation to the particles between the electrodes 1 and 5 on. This means that in a typical Image production process when an electric field is applied to the electrodes 1 and 5, the particles 4 in the Dark can be attracted to either electrode 1 or electrode 5, whichever is of these electrodes has a polarity that is opposite to the original charge polarity of the particles.

is set. If the particles 4 are irradiated with activating electromagnetic radiation, this takes place quite obviously a neutralization or a reversal of the charge polarity in ile exposed or unexposed particles.

In a typical device for manufacturing of images by the electrophoretophotographic route in which the electrode 1 has a conductive surface the charge polarity of the exposed particles 4 changes when they are in electrical contact, which does not necessarily have to consist of physical contact with the conductive surface (charge reversal usually takes place), with the change in charge polarity as a result the combined application of an electric field and the action of activating radiation is Weist on the other hand, the surface of the electrode 1 is a dark charge exchange material as in the BE-PS 8 23 351 described on, one obtains a reversal of the charge polarity of the non-exposed particles, while the original charge polarity of the exposed electrically photosensitive particles is retained, when these particles are in electrical contact with the dark charge exchange surface of the electrode 1 reach. In any case, when the electric field and activating radiation act on the Particles 4 achieve an image resolution. Typically, a device such as that shown in FIG Drawing is shown a visible image on the surface of the electrode 1 and a complementary one Image on the top of the electrode 5.

Following the application of an electric field and exposure, the on the surfaces of the Electrodes 1 and / or 5 of the device generated images temporarily or permanently on these electrodes fixed or transferred to an image receiving material. Filxing of the image particles can after known methods.

As already mentioned, the compounds which can be used according to the invention are in particular to those of yellow or orange hues, which as a result are particularly useful for manufacturing of multicolored images are suitable, being a mixture of two or more different colored particles is used, e.g. B. a mixture of blue-green particles that are primarily sensitive to red light are purple-red particles that are primarily sensitive to green light and are yellow or orange Particles that are primarily sensitive to blue light. Will be a mixture of such electrical light-sensitive particles generated, for example in an electrically insulating carrier liquid, so has this liquid mixture turns black. They are preferably used in individual cases cyan, magenta and yellow particles are selected for the production of multicolor images such that their spectral curves do not substantially overlap, so that color separation and reproduction of a sub * ractive multicolor image can be achieved.

The compounds which can be used according to the invention can be, for example, by reacting a Making aldehydes or ketones with a compound with an active methylene group. Schematically leaves the production of the connection is illustrated by the following equation:

C = O + CH-Ar-CH

/ I

Activating activators
Group group

where R ¹ , R ² , R ⁴ , R ⁶ , A and Ar are the already given House, "Modem Synthetic Reaction", 2nd edition,

Have meaning.

Furthermore, in formula I m can have the meaning of 1 (as in the case of the reaction scheme shown) or the meaning of 2, in which case a compound of one of the following two formulas is used:

CH-Ar-C = C-Ar-CH

50

R ⁴ R ⁵

Activating
group

Activate group

CH-Ar-C = C-Ar
/ R ⁴ R ⁵

Activating group

55

60

wherein Ar, R ⁴ and R ^{5 have} the meanings already given.

The activating group can consist of a variety of different activating groups, such as them are described in more detail, for example, in H. O.

Verlag W. A. 3enjamin, Inc., USA, pages 492 to 497 (1972).

The preparation of compounds used according to the invention is described in more detail below, for example will.

Production example 1

Production of 6,6 '- (p-phenylenedivinylene) -

bis (N-ethyl-1,2,3,4-tetrahydroquinoline),
corresponding to compound no. 5 of Table I.

A solution of 7.95 g of 6-formyl-N-ethyl-1,2,3,4-tetrahydroquinoline and 7.56 g of tetraethyl were added dropwise under a nitrogen atmosphere to a vigorously stirred suspension of 2.43 g of sodium methoxide in 40 ml of dimethylformamide. Given p-xylylene diphosphonate in 40 ml of dimethylformamide. After about 36 hours of stirring at room temperature the reaction mixture in I ^1/2 liters of water was poured. The solid precipitate was filtered off and recrystallized twice from xylene. The solid reaction product had a melting point of 213 to 215 ° C. with decomposition and corresponded to compound No. 5 of Table I, as was shown by spectroscopic investigations of the molecular structure.

I ι

21 22

Preparation Example 2 Preparation of 9,9 '- (a, a'-Dicyano-p-phenylenedivinyene) bis-juloids, Compound 1 of Table I.

The connection was established according to the following reaction procedure:

CN

NKOKHO +

CN

CN

A mixture of 6.23 g (0.031 mol) of 9-formyljuloliden, 2.34 g (0.015 mol) of p-benzene diacetonitrile, 6 ml of piperidine, 3.6 ml of acetic acid, 15 ml of n-propyl alcohol and 50 ml of benzene was after under a nitrogen atmosphere for 36 hours using a trap Dean-Stark heated to reflux temperature. The reaction mixture was then allowed to cool, whereupon the crystalline reaction product was filtered off. It was recrystallized twice from xylene and had a Melting point from 284 to 286 ° C with decomposition. Spectroscopic investigations showed that the compound corresponded to compound 1 of Table I.

To carry out the experiments described below for the production of images on photoelectrophoretic A device of the type shown in the drawing was used.

A permeable glass plate with a sprayed-on conductive indium oxide layer was used as the electrode 1 was in pressure contact with an electrode 5 consisting of an aluminum roller 14. The aluminum roller 14 had a diameter of 10 cm and was coated with a layer of a resilient polymer The polymer layer was coated with an insulating layer 6 made of poly (vinyl butyral) and TiC> 2 particles Paper covered. The plate 1 was on two rubber drive rollers 10 with a diameter of 2.8 cm, which were arranged so that a 2.5 cm opening symmetrical about the axis of the aluminum roller 14 arose through which the photoelectrophoretic particles 4 are irradiated with activating radiation could. The original 11 to be reproduced was attached to the back of the electrode 1, for example by means of an adhesive tape. The exposure to activating radiation was carried out by means of a light source 8, the in the present case from a slide projector with a maximum exposure intensity of 26,910 Lx existed at the electrode level. A Wratten No. 2A filter was inserted into the light beam so that there was no exposure through the ultraviolet portion of the spectrum. The tension between the Electrode 1 and 5 was 1 kilovolt. Electrode 1 was the negative pole in the case where the photoelectrophoretic particle 4 was a positive one carried electrostatic charge. In contrast, the electrode 1 was the positive pole when the photoelectrophoretic Particles were negatively charged.

The speed at which the electrode 1 could be conveyed through the transport rollers 10 was between 1.25 cm and 30 cm per second.

In the following examples, images were formed on the surfaces of the electrode 1 and the electrode Electrode 5 after simultaneous exposure to light and application of the electric field.

The various photoelectrophoretic particles to be tested were used to conduct the experiments 4 mixed with a liquid carrier, so that a liquid dispersion in the gap 21 between the Electrodes 1 and 5 was inserted. In those cases where photoelectrophoretic particles 4 have the required had electrical photosensitivity, a negative reproduction of the original 11 was on the Electrode 5 and a complementary image on electrode 1 obtained.

The dispersions used to carry out the process were prepared as follows Procedure:

A total of eight different dispersions were produced and tested. The preparation of the dispersions took place in a ball mill, in which the compounds to be tested in high concentration with a polymeric charge control agents were ground. The mixture obtained was then treated with a further polymer solution diluted The proportions of the individual components used in the individual case of the dispersions to one another and the exact composition of the dispersions produced results from the following:

A ball mill was made with the following components

besc-hicki:

1. one gram of the material to be tested for its photoelectrophoretic properties,

2. one gram of a polymeric charge control agent, consisting of a copolymer of vinyl toluene, lauryl methacrylate, lithium methacrylate and methacrylic acid at a monomeric weight ratio of vinyl toluene to lauryl methacrylate to lithium methacrylate to methacrylic acid from 56: 40: 3.6: 0.4,

3. 110 g of stainless steel grinding balls with a diameter of 3 mm and

4. 12.2 g of a commercially available carrier liquid made from 96% aromatic and 4% aliphatic hydrocarbons with a boiling range of 157 to 177 ° C.

The concentrate was ground in a ball mill with a 175 ml glass vessel 115 revolutions per minute. The grinding time was at least 1 week. The obtained in this way Concentrates were then each made by adding 35.8 g of a 40% strength by weight solution of a styrene-toluene copolymer in a boiling range solvent consisting of isopraffine hydrocarbons diluted from 145 to 186 ° C. The resulting dilute dispersions were then redone Grind in the ball mill for at least one day.

Eg pi ele 1 to 8

Dye C

In the following Table II are the results of experiments with a total of 13 different tested Connections indicated. The first eight compounds in Table II are the Compounds 1 to 7 and 11 of Table I. All of these eight compounds tested have a structure according to Formula I. For comparison purposes were also tested:

a) a from US-PS 33 84 488 known photoelectrophoretic dye with allegedly good electrical photosensitivity and suitability for electrophoretophotographic imaging processes of the following structure:

O HN-C- (CH ₂ VCH ₃

Dye D

O HN
O = C- (CH ₃ ) J-CH ₃

35

Dye A4 "

b) four acylaminoanthraquinones of the type known from DE-OS 24 54 362, namely:

Dye B

Table II also shows the speed of the electrode 1 at which it moves through the transport rollers 10 was moved.

Compounds 1 to 7 and 11 used according to the invention also provided images of good blue density

A maximum reflection density of 0.4 to 1.7 with advantageous minimum densities in the background areas. The indicated densities were determined from the images produced on the electrode 5 became. From the results obtained, the

£ θ Advantageousness of those used according to the invention Compounds compared to the comparative compounds also tested, in particular their considerably larger ones Photosensitivity

Table II

tested connection

Intensity of the
Used light in the exposure
Exposure level c
in Ix

Electrode speed 1

(cni / sec.) Amax

(nm)

Image quality 0.3 Blue density 0.5 0.4 / 0.1 1.62 0.9 / 0.4 1.12 1.7 / 0.08 0.7 1.2 / 0.08 0.95 0.8 / 0.1 0.3 1.0 / 0.05 0.4 0.5 / 0.2 0.3 0.5 / 0.1 <0.04 0.6 / 0.3 very low Image density no picture no picture no picture

1 (invention)

2 (invention)

3 (invention)

4 (invention)

5 (invention)

6 (invention)
7 (invention)
11 (invention)
Dye A
Dye B

Dye C
Dye D
Dye E

269.1

1076.40

2691.0

2691.0

2691.0

2691.0

269.1

269.1

26910

26910

26910
26910
26910

25th
25th
25th
25th
25th
25th
25th
25th
25th
25th

25th
25th
25th

560
510
490
460
460

520
520
460

Example 9

This example describes the use of compounds of formula I in the context of a multicolor electrophoretophotographic imaging process.

First there were three different cyan, purple and yellow monochrome color dispersions manufactured. Each dispersion was prepared as described. The electrically light-sensitive Connection for the production of the blue-green dispersion consisted of the beta form of copper phthalocyanine, i.e. a dye of Color Index No. 74160. The The electrically photosensitive compound used to make the purple dispersion consisted of a quinacridone pigment. The electrically photosensitive compound for making the yellow dispersion consisted of 9,9 '- (p-phenylene-divinylene) bisjuloliden.

Portions of the three monochromatic dispersions became cyan to magenta by volume mixed together to form a yellow dispersion of 1: 1: 2. The dispersion obtained was then under Tested using the device described.

The intensity of the imagewise exposure on the electrode was 1,37,674 Ix. The speed at which the electrode 1 was conveyed by the transport rollers was 10 cm / sec. In the beam of light were introduced: a Wratten filter 2 A and an interference filter (30% transmission at 665 nm), so that the exposure was made with visible light only.

The voltage applied to electrodes 1 and 5 was 1 kilovolt

A three-color negative-positive copy of good quality was produced on layer 6 of electrode 5 and furthermore a positive-positive copy of good quality on the surface of the electrode 1.

Example 10

The procedure described in Use Example 9 was repeated with the exception, however, that this time as a yellow pigment for the preparation of the yellow dispersion the compound 5 of Tables I and II was used, i.e. H. 6,6 '- (p-Phenylenedivinylene) bis (N-ethyl-1,2,3,4-tetrahydroquinoline.

The same results as in the case of Example 9 were obtained, i.e. it was again a three-color negative-positive copy of good quality on the layer 6 of the electrode 5 obtained and also a good multicolored positive-positive copy on the surface of the electrode 1.

Examples 11-14

Following the procedure described in Examples 1 to 8, compounds 8, 9, 10 and 12 were obtained Table 1 tested. All four compounds were found to have excellent electrical sensitivity Compounds 8, 10 and 12 were found to be even better showed electrical sensitivity than compounds 3 to 6 of Table IL

The pigment dispersions described below were produced by the method described manufactured. The device for determining the sensitivity corresponded to that in FIG. 1 shown Contraption.

Starting from the compounds 2, 3 and 4 of Table 1, three different yellow dispersions were produced manufactured. Furthermore, using the pigments given in Example 9, a purple-red and produced a blue-green dispersion

Portions of the yellow dispersions in two different concentrations were added to different proportions of the magenta dispersion and the cyan dispersion. The concentrations were 1 part by weight and 5 parts by weight of the compounds in Table 1 per 50 parts by weight of the compounds of the purple-red and blue-green dispersions. The effective amounts of the compounds of Table 1 added to the magenta and cyan dispersions were 0.04% and 0.18%.
A total of 8 dispersions were tested, of

Al «ill!

, H ■ «■>

six of which were sensitized and two were not. The test parameters were as follows:

Light intensity:

21,528 Ix modified with a Wratten No. 2A filter and a 65 nanometer interference filter;

Electrode potential:

1500 volts transmission at an electric speed of 23 cm per second in the case of the blue-green dispersion and 15 cm per second in the case of the magenta dispersion;

Electrode speed:

23 cm per second in the case of the blue-green dispersion and 15 cm per second in the case of the purple dispersion.

The test template for performing this test consisted of adjoining red, green and blue filters, each with a step wedge with a neutral density of 0.3.

To determine the increase in sensitivity caused by the compounds in Table 2, the light intensity required to obtain an average copy reflection density due to a color exposure, Complementary to the emulsion paint compared to the intensity that was required to achieve to achieve the same reflection density in the case of the non-sensitized comparative dispersions. For example were the relative intensities of red light for the same mean red copy reflection density in the case of the sensitized and the non-sensitized blue-green dispersion, compared with one another, whereupon the increase in sensitivity was calculated. Similarly, in the case of the crimson Procedure for dispersion. The copy densities of the other color exposures correspond to undesired absorptions were measured in the same way. The ratios of the increase in sensitivity of the primary Absorption to the undesired absorption of the sensitized dispersions and the unsensitized dispersions Comparative dispersions were calculated and compared with one another. These circumstances were within experimental error limits the same, from which it follows that the sensitization is primarily chemical than was of a spectral nature.

Table 3 shows the relative speed increases for the two sensitization concentrations used in comparison to the non-sensitized comparison samples.

The example illustrates the sensitization effects which can be achieved with the compounds according to the invention which can be used.

If one of the compounds of formula 1 is used as one of three components for the production of a polychrome Mixture used, so it is obvious that the compound is not only used as a photoelectrophoretic Particle acts, but also as a sensitizer for the magenta and cyan components, without disadvantageous spectral shifts occur.

Table 3

Ver Relative increase in sensitivity Dispersion blue-green Dispersion binding Conc Sensibili Conc from purple tration sator tration Table 1 Sensibili 0.18% 0.04% 0.18% sator 0.04%

10
16
16

16
16
16

1 sheet of drawings.

Claims (3)

Claims: 1. Use of compounds of the formula: in which: A is an optionally substituted alkyl lenrest with 2 to 5 carbon atoms in the alkylene chain; Ar is an optionally substituted aromatic ring with 6 to 20 ring atoms, which has no further fused-on saturated N-heterocyclic ring; R ¹ and R ² together represent an optionally substituted alkylene radical having 2 to 5 carbon atoms; Ri, R ⁴ , R5 and R ⁶ individually in each case a hydrogen or halogen atom, a nitro or cyano radical or an alkoxy radical with 1 to 8 carbon atoms, an optionally substituted alkyl radical with 1 to 8 carbon atoms in the alkyl radical, an optionally substituted phenyl radical, a carboxy ester radical with 1 up to 4 carbon atoms or an amide radical of the formula: R ⁷ —CON R ⁷ 15th 20th 25th 30th 35 40 2. Use of compounds according to claim 1, characterized by the following structural formula: Ar- C = C
R ⁴ R ⁵ O> N R ² in which: Ar is an optionally substituted aro matic ring with 6 to 20 ring aromas; R ⁴ and R ⁵ each represent a hydrogen atom or a cyano radical and R ^{2 is} an optionally substituted alkyl radical with 1 to 8 carbon atoms in the alkyl radical or an optionally substituted one Phenyl radical. 3. Use of compounds according to claim 1, characterized by the following structural formula: Ar- in which R ^{7 represents} a hydrogen atom, an optionally substituted phenyl radical or an optionally substituted alkyl radical having 1 to 8 carbon atoms in the alkyl radical; R ² individually represents a hydrogen atom, an optionally substituted alkyl radical with 1 to 8 carbon atoms in the alkyl radical or an optionally substituted aromatic ring with 6 to 20 ring carbon atoms and in = 1 or 2 as photoelectrophoretic particles or sensitizers for photoelectrophoretic particles in electrophoretophotographic process. 50 55 meaning: Ar is an optionally substituted aro matic ring with 6 to 20 ring atoms and R ⁴ and R ⁵ each represent a hydrogen atom or a cyano radical. 4. Use of compounds according to Claims 1 to 3, optionally together with others Dyes, in the form of a suspension of dye particles in an electrically insulating carrier liquid. 5. Use of compounds according to Claims 1 to 4, characterized by one of the following formulas: b. c. e. 3 4 / \ r / VJ ο io QH ₅ CH, CN OCH ₃ ^ 1 "'L , ι . There are, e.g. from US-PS 27 58 939, 29 40 847, 3100 426, 3140175, 1143 508, 33 84 565, 33 84 488, 36 15 558.33 84 566 and 33 83 993, DE-AS 16 22 380 and DE-OS 24 54 362 electrophoretophotographic image production process known in which photoelectrophoretic particles between at least two electrodes under the action of an electric Field exposed and forming an image on at least one of the electrodes imagewise with a Radiation sensitive to the dye can be irradiated. Another electrophoretographic Process which is an image reversal process is, for example, from BE-PS 8 23 351 known Regardless of the particular type of electrophoretophotographic process employed, to carry out the photoelectrophoretic process Particles required. In order to obtain an easily recognizable, visible image, it is essential that this Particles are colored and furthermore electrically sensitive to light. It therefore has no attempts failure to find dyes which can be used for carrying out electrophoretophotographic processes suitable and not only have the required electrical sensitivity to light, but also eo have good coloring properties. From US-PS 27 58 939 and 29 40 847 it is known photosensitive particles as photoelectrophoretic particles for carrying out electrophoretophotographic processes To use pigments for the production of conventional photoconductive recording materials can be used. Furthermore, it has long been known, for example, that the US-PS 36 15 558 for the implementation of electrophoretophotographic Imaging process recommended phthalocyanine pigments excellent photoconductive Have properties. From DE-OS 24 54 362 it is also known as photoelectrophoretic Particles in electrophoretophotographic processes to use pigment particles, which one water-insoluble compound with at least one in • an α-position acylamino group lies. From DE-PS 16 22 380 it is finally for example known as photoelectrophoretic particles in electrophoretophotographic processes, pyrene derivatives to use. From US-PS 36 81 068 it is also known as organic photoconductor compounds with a To use Julciylgruppe. The disadvantage of the known photoelectrophoretic particles is that they are still sensitive to light leaves too much to be desired, so that they can often only be used when light is comparatively low high intensity is available The object of the invention was photoelectrophoretic particles for carrying out electrophoretophotographic Specify image production processes, which are characterized by a particularly high sensitivity and which can also be used successfully when used for exposure Available light source has a comparatively low intensity It has been found that the compounds described in more detail below are not only excellent are effective photoelectrophoretic particles, but