DE2018038C3 - Process for the production of an electrophotographic recording material - Google Patents

Description

35

+ X

R,

z-

40

wherein R ₁ and R ₂ each equal to a phenyl group or substituted phenyl group in which a substituent consists of an alkyl or alkoxy group having 1 to 6 carbon atoms, R ₃ being a phenyl group which is substituted by an alkylamino group having 1 to 6 carbon atoms in the alkyl group is, X is an oxygen or sulfur atom and Z- is an anion, is used.

4. The method according to claim 3, characterized in that a sensitizing dye 2,4,6-triphenylthiapyrylium dye salt used will.

5. The method according to claim 4, characterized in that the 2,4,6-triphenylthiapyrylium dye salt is 4- (4-dimethylaminophenyO-2,6-diphenylthiapyrylium fluorate or 4- (4-dimethylaminophenyl) -2,6-diphenylthiapyrylium perchlorate is used.

6. The method according to claims 1 and 2, characterized in that a halogenated solvent is used Alkane having 1 to 3 carbon atoms is used.

7. The method according to claim 6, characterized in that the solvent is dichloromethane is used.

8. The method according to claims 1 and 2, characterized

characterized in that the binder is a polycarbonate is used.

9. The method according to claim 2, characterized in that a di-, tri- or photoconductor Tetraarylalkane, in the least! an aryl group is substituted by an amino group and in which the aryl group is equal to a phenyl or naphthyl group, an organometallic compound, in which at least one aminoaryl group is attached to a metal atom of the group lilac, IVa, or Va of the Periodic Table of the Elements, or a di- or triarylamine is used.

10. The method according to claim 9, characterized in that the photoconductor 4,4'-diethylamino-2,2'-dimethvitriphenylmethane, 4-diethylaminotetraphenylmethane, 4,4 \ 4 "-Tris- (diethylamino) -tetraphenylstannane, Diphenyl-bis- (p-diethylaminophenyl) -stannane or Tetra-p-diethylaminophenylgerman is used.

11. The method according to claim 2, characterized in that to 100 parts by weight of solids 0.5 to 30 parts by weight of sensitizing dye and 10 to 80 parts by weight of photoconductor can be used in the coating solution.

The invention relates to a method for producing an electrophotographic recording material of an electrically conductive substrate and at least one heterogeneous photoconductive layer, the of a continuous phase of a binder and a discontinuous phase with a content on at least one sensitizing dye, the aggregates visible at 250X magnification consists in which a coating liquid containing sensitizing dye, binder and solvent applied to the support and the layer obtained is dried.

Electrophotographic recording materials and electrophotographic processes of various kinds Type are known and are described in numerous references, e.g. B. U.S. Patents 2 221776; 2,277,013; 2,297,691;

2,357,809; 2,551,582; 2,825,814; 2,833,648; 3,220,324;

3,220,831 and 3,220,833. For the production of images with the aid of electrophotography, as a rule an electrophotographic recording material having a normally insulating photoconductive one Layer exposed imagewise to electromagnetic radiation with formation of a latent electrostatic Charge image, whereupon the latent image obtained is converted into a visible, permanent egg is transferred.

The use of an electrophotographic recording material has proven to be particularly advantageous proved to have a photoconductive layer made of an electrically insulating resinous substance having dispersed photoconductor. For the production of such an electrophotographic recording material is usually the photoconductive coating composition in the form of a layer on a Layer carrier applied, which covered voirher with a layer of an electrically conductive material had been, or directly on an electrically conductive substrate, e.g. B. on a layer support

ius an electrically conductive metal. It shows that the electrophotographic properties, e.g. B. the sensitivity and / or speciral characteristics of the conductive layers of the electrophotographic obtained Recording materials can be improved by using the photoconductive iron One or more photosensitive coating compositions Substances or additives are incorporated. Typical suitable such additives are z. See U.S. Patents 3,250,615; 3,141,770 and 2 9S7 395. Photosensitizing additives of the specified type have an advantageous effect Way a change in the sensitization or sensitivity of the photoconductive layer of which it is are incorporated, and / or a change in their spectral characteristics. So z. B. with help such additives reduce the sensitivity of an electrophotographic recording material to Radiation of a certain wavelength increased or possibly compared to a broad wavelength range be effected. The mechanism causing such awareness is currently, in spite of it the extreme importance of this phenomenon has not yet been fully elucidated. The special meaning which attaches the technical pain to the indicated sensitization, results z. B. from the fact that in all relevant Experts are working intensively on advantageous photosensitizing compounds for photoconductive ones Coating compounds of the specified type is researched.

The manner in which a change in electrophotographic properties is sought usually depends on it. for what purpose the respective electrophotographic Recording material is intended. So should z. B. in the document copying technology in the Electrophotographic recording material, photoconductors present a spectral sensitivity have, which enables the reproduction of the entire, in this case, a wide range of colors. If the photoconductor used does not or not completely meet the specified conditions, then its spectral properties in an advantageous manner by adding spectral sensitizing additives of the specified type changed. The influence often turns out to be used for other purposes other electrophotographic properties as advantageous, in this way e.g. B. electrophotographic To achieve recording materials that are able to absorb a high surface potential and have further advantageous properties, ζ. B. a small charge drop in the dark, a high sensitivity resulting from the sensitivity curve, a low residual potential after the Exposure and resistance to fatigue.

Often, the sensitization of the photoconductive ones intended for the manufacture of electrophotographic recording materials becomes Coating compositions with a content of photoconductors of a certain type by adding certain dyes from the causes a large number of the currently known dyes. The disadvantage, however, is that by adding this known additives usually no photoconductive coating compositions are obtained in which all specified properties that only work together to produce high-quality electrophotographic Lead recording materials are noticeably improved. So it still looks like a need for methods of making such electrophotographic Recording materials with improved properties, e.g. B. improved sensitivity wedge in the shoulder and toe area of the sensitivity curve, improved playback properties for full areas, rapid regeneration and advantageous electrophotographic sensitivity Both positive and negative electrostatic Charging.

Processes are already known with the aid of which electrophotographic recording materials have Heterogeneous photoconductive layers containing dye aggregates and having most of the specified Disadvantages of known electrophotographic recording materials do not have, can be produced. So z. B. in Belgian patent specification 705 117 a process for the production of an electrophotographic Recording material described, in which a sensitizing dye and a polymer Binder dissolved in a customary known solvent, the coating composition obtained applied an electrically conductive layer support, dried the layer obtained and then treated with a solvent or solvent vapors to soften the layer and the to aggregate existing dye molecules. The disadvantage of this known Veifahren, however, is that an additional process step after the application of the coating compound, namely the treatment with a solvent, is required. Furthermore, in the Belgian patent specification 705 118 a method for producing an electrophotographic recording material of the specified Type described, with the help of which the necessary subsequent to the coating of the substrate additional process step avoided and the aggregate formation of the dye molecules thereby caused that the coating composition is a sensitizing dye and polymers! Binder strong before application to the substrate, at high Speeds generated is subjected to shear forces. The disadvantage of this known method is, however, that for its implementation also an additional

Process stage, namely the action of shear forces on the coating compound, is required. There is also already known a method according to which electrophotographic recording materials with higher sensitivity than according to the methods known from the Belgian patents cited can be produced. So z. B. in the Belgian patent 729 078 a method described after that on the photoconductive layer of an electrophotographic produced by known methods Recording material an additional layer of a dye in the form of a dye solution is applied. However, this known method has the disadvantage that it is an additional Requires coating process.

Another disadvantage of the known processes specified is that the production of the heterogeneous photoconductive coating compositions used dyes have different crystalline structures. Depending on the type of the present crystalline structure of the dye, the formation of the dye aggregates comparatively easily or very easily when using the known methods indicated to be difficult.

<ί

The object of the invention is to provide a method with the help of which simply by producing a photoconductive coating solution and applying the same to a support highly sensitive electrophotographic recording materials with photoconductive layers containing the sensitizing dyes contained in the form of aggregates, regardless of the type of the present crystalline structure of the dyes used, using a single coating process without additional, the formation of dye aggregates intended process stages can be produced.

The invention is based on the knowledge that the specified object can be achieved in that the consisting of sensitizing dye, film-forming polymeric binder and solvent Coating solution is produced in a precisely defined manner.

The invention relates to a process for the production of an electrophotographic recording material of an electrically conductive layer support and at least one heterogeneous photoconductive one Layer made up of a continuous phase of a binder and a discontinuous one Phase containing at least one pyry-hum, thiapyrylium or selenapyrylium sensitizing dye, which forms recognizable aggregates at a magnification of 2500x, consists in which a sensitizing dye, binder and Solvent-containing coating liquid applied to the support and the obtained Layer is dried, which is characterized in that for the preparation of the coating liquid the sensitizing dye (s) dissolved in the solvent, the binder added to this solution and the mass obtained is intimately mixed before application to the substrate.

The invention achieves that high quality electrophotographic recording materials with improved sensitivity and ge if desired, higher dye concentration and with improved regenerative capacity regardless of the crystalline structure of the sensitizing dyes used in a simple, easily controllable as well Can be produced in a time- and cost-saving manner.

The heterogeneous coating solutions useful in practicing the method of the invention act both as photoconductors and as sensitizers for photoconductors.

According to the invention, the dyes used are thus dissolved in an organic coating solvent before further additives are added to them. Only after the dyes have dissolved are polymeric binders added to the solutions obtained, as a rule, with stirring, and the binders dissolved. In this way, heterogeneous, multiphase coating solutions are obtained whose discontinuous phase consisting of dye aggregates is visible at 2500x magnification, although the coating solutions obtained may appear practically optically clear to the naked eye. If necessary, however, there can also be a macroscopic heterogeneity. The dye aggregates forming the discontinuous phase expediently for the most part have a particle size of about 0.01 to 25 microns. Are used, however, the resulting heterogeneous Bisc'iichtun'jslösungcn for sensitizing ^{additionally:} it / .lic'i existing particulate photoconductors z. B. zinc oxide, its discontinuous phase may consist of particles with a particle size outside the specified range.

The heterogeneous phctoconductive compositions obtained according to the invention consist of multiphase organic solids containing dyes and polymeric binders. The polymeric binders form an amorphous basic structure in the form of a continuous phase which contains a separate discontinuous phase, which makes it different from a solution. The discontinuous phase contains a substantial proportion, usually the majority, of the sensitizing dye present. It can be assumed that the dye present in the discontinuous phase is in the form of particles, but this discontinuous phase need not consist entirely of dye molecules. exist. Presumably in some cases the discontinuous phase consists of a cocrystalline complex of dye and polymeric binder, but it can be assumed that the dye aggregates that can be produced according to the invention do not necessarily consist of dye and polymer. Preferably, virtually all of the dye present is in the discontinuous phase.

Will the when using the method of the invention accruing coating material used in combination with an organic photoconductor, so the formed photoconductive mass usually contains only two phases, since the photoconductor with the Polymer existing continuous phase usually forms a solid solution. Will on the other hand the multiphase coating composition obtained using the method of the invention in combination used with a particulate photoconductor, there may be three phases, namely a continuous phase consisting of polymer, and also a sensitizing dye containing discontinuous phase of the specified type and also a further discontinuous phase Phase from the particulate photoconductor. Of course, this can be done when using the method The multiphase coating material obtained according to the invention, optionally also additional discontinuous ones Phases, e.g. B. from trapped impurities and the like., Contained.

Another feature of the coating compositions obtained using the method of the invention is the fact that its absorption maximum lies in a spectral range that is longer or is shorter-wave than that in which the absorption maximum consists of a practically homogeneous mass Dyes and polymers of the same type if they are in the form of a solid solution. How far the absorption maximum of such heterogeneous coating materials due to the formation is shifted by dye aggregates to other wavelength ranges depends on up to what percentage of the dye present aggregates. In the case of using the method of Invention resulting multiphase heterogeneous coating compositions the absorption maximum is usually shifted by at least about 10 ΐημ compared to homogeneous masses of a comparable type. If mixtures of substances are used, then if necessary a dye the lace of the absorption rmxirnil'TlS nac'l

Wr> llr> nl? Inai »n

another dye shift the position of the absorption maximum to shorter wavelengths. Stand out in such a case the shifts in position of the absorption maximum more or less, see above if it is possible to prove that a heterogeneous coating compound is present, this may be easier Visualization of the discontinuous phase with appropriate enlargement.

A variety of sensitizing dyes are used in practicing the method of the invention Type usable. Typical suitable sensitizing dyes are e.g. B. pyrylium dyes, for example Pyrylium, thiapyrylium and selenapyrylium dye salts of the general formula:

»5

R "

z-

Connection

Table I.

designation

1 4- [4-bis- (2-chloroethyl) aminophenyl] -2,6-diphenylthiapyryIium perchlorate

2 4- {4-dimethylaminophenyl) -2,6-diphenylthiapyrylium perchlorate

^a 5

in which:

R «, R *, R ^c , R" and R " alone are hydrogen atoms, alkyl radicals with z. B. 1 to 15 carbon atoms, for example methyl, ethyl, propyl, isopropyl, butyl, tertiary butyl, amyl, isoamyl, hexyl, octyl, nonyl or dodecyl, alkoxy, e.g. B. methoxy, ethoxy, propoxy, butoxy, amyloxy, hexoxy or octoxy radicals, or optionally substituted aryl radicals of the phenyl and naphthyl series, z. B. phenyl or 4-diphenyl radicals, or alkylphenyl radicals, e.g. B. 4-ethylphenyl or 4-propylphenyl, or alkoxyphenyl, z. B. 4-ethoxyphenyl, 4-methoxyphenyl, 4-amyloxyphenyl, 2-hexoxyphenyl, 2-methoxyphenyl or 3,4-dimethoxyphenyl, or / J-hydroxyalkoxyphenyl, z. B. 2-Hydroxyäthoxyphenyl- or 3-Hydroxyäthoxyphenylreste, or 4-Hydroxy phenylreste or Haiogenphenylreste, z. B. 2,4-dichlorophenyl, 3,4-dibromophenyl, 4-chlorophenyl or 3,4-dichlorophenyl, or azidophenyl, nitrophenyl or aminophenyl, e.g. B. 4-diethylaminophenyl or 4-dimethylaminophenyl radicals, or naphthyl radicals or vinyl-substituted aryl radicals, e.g. B. styryl, methoxystyryl, diethoxystyryl, dimethylaminostyryl, 1-ButyM-p-dimethylaminophenyl-l ^ -butadienyl- or / ^ - Äthyl ^ dimethylaminostyryl or R ^a and R * or R ^d and R ^c together to complete an aryl ring fused to the pyrylium nucleus, X is a sulfur, oxygen or selenium atom and Z "is an anion, ζ. B. a perchlorate, fluoroborate, iodide, chloride, bromide, sulfate, periodate or p- Toluene sulfonate ion.

Typical suitable pyrylium dyes are listed in Table I below

Connection no.

designation

4- (4-DiiTu: ethylaminophenyl) -2,6-diphenylthiapyrylium fluoroborate

4- (4-Dimt: thyiamino-2-methylphenyl) -2,6-diphenylpyrylium perchlorate 4- [4-bis (2-chloroethyl) aminophenyl] -2- (4-methoxyphenyl) -6-phenylthiapyrylium perchlorate

4- (4-dimethylaminophenyl) -2,6-diphenylthiapyrylium sulfate

4- (4-Dimethylaminophenyl) -2,6-diphenylthiapyrylium p-toluenesulfonate 4- (4-dimethylaminophenyl) -2,6-diphenylpyrylium-p-toluenesulfonate

2- (2,4-Dimethoxyphenyl) -4- (4-dimethylaniinophenyl) benzo (b) pyrylium perchlorate 2,6-bis (4-ethylphenyl) -4- (4-dimethylaminophenyl) -t! Iiapyrylium perchlorate 4- (4-Dimethylaminophenyl) -2- (4-methoxyphenyl) -6-phenylthiapyrylium perchlorate 4- (4-Dimethylaminophenyl) -2- (4-ethoxyphenyl) -6-phenylthiapyrylium perchlorate 4- (4-Dimethylaminophenyl) -2- (4-methoxyphenyl) -6 - (^> - methylphenyl) pyrylium perchlorate

4- (4-Diphenylaminophenyl) -2,6-diphenylthiapyrylium perchlorate

2,4,6-triphenylpyrylium perchlorate 4- (4-methoxyphenyl) -2,6-diphenylpyrylium perchlonite

4- (2 _f 4-dichlorophenyl) -2,6-diphenylpyrylium perchlorate

4- (3,4-dichlorophenyl) -2,6-diphenylpyrylium perchlorate

2,6-bis (4-methoxyphenyl) -4-phenylpyrylium perchlorate

6- (4-methoxyphenyl) -2,4-diphenylpyrylium perchlorate

2- (3,4-Dichiorophenyl) -4- (4-methoxyphenyl) -6-pheny 1 pyrylium perchlorate 4- (4-amyloxyphenyl) -2,6-bis (4-ethylphenyl) pyrylium perchlorate

4- (4-Amyloxyphenyl) -2,6-bis (4-methoxyphenyl) -pyric 1 µm -perchlorate

2,4,6-triphenylpyrylium fluoroborate 2,6-bis (4-ethylphenyl) -4- (4-methoxyphenyl) pyrylium perchlorate

2,6-bis (4-ethylphenyl) -4- (4-methoxyphenyl) pyrylium fluoroborate

6- (3,4-diethoxystyryl) -2,4-diphenylpyirylium perchlorate

6- (3,4-dietllioxy / 3-amylstyryl) -2,4-diphenylpyrylium fluoroborate

6- (4-Dimetfaylamino - /? - ethylstyryl) -2,4-diphenyl pyrylium.-fluoroborate

6- (l-n-A; tnyl-4-p-dimethylaminophenyl, 3-butadienyl) -2,4-diphenylpyryliumfluoroborai:

6- (4-Din "ethylaminostyryl) -2,4-diphenylpyrylum fluoroborate

6- [a-Ethyl - ^, ^ - bis (dimethylaminophenyl) -vinyJen] -2,4-diphenylpyrylium fluoroborate 6- (1-butyl-4-p-dimethylaminophenyl, 3-butadienyl) -2,4-diphenylpyrylium fluoroborate

6- (4-dimethylaminostyryl) -2,4-diphenylpyrylium perchlorate

609 621/396

connection
No.

Designation connection

No.

designation

35 6 - [/ f, /? - bis (4-dimethylaminophenyl) vinylene] -2,4-diphenylpyrylium perchlorate

36 2,6-bis (4-dimethylaminostyryl) -4-phenylpyrylium perchlorate

37 6 - (/? - MethyI-4-dimethyiaminostyryl) -2,4-diphenylpyrylium fluoroborate

38 6- [l-Ethyl-4- (4-dimethylaminophenyl) -1, 3-butadienyl] -2,4-diphenylpyrylium- fluoroborate

39 6 - [/?, / J-bis (4-dimethylaminophenyl) vinylene] -2,4-diphenylpyryIium fluoroborate

40 6- [1-methyl-4- (4-dimethylaminophenyl) -1, 3-butadienyl] -2,4-diphenylpyrytium- fluoroborate

41 4- (4-Dimethylaminophenyi) -2,6-diphenylpyrylium oerchlorate

42 2,6-bis (4-ethylphenyl) -4-phenylpyrylium perchlorate

43 2.6-Bis (4-ethylphenyl) -4-methoxyphenylthiapyrylium fluoborate

44 2,4,6-triphenylthiapyrylium perchlorate

45 4- (4-methoxyphenyl) -2,6-diphenylthiapyrylium perchlorate

46 6- (4-methoxyphenyl) -2,4-diphenylthiapyrylium perchlorate

47 2,6-bis (4-methoxyphenyl) -4-phenylthiapyrylium perchlorate

48 4- (2,4-dichlorophenyl) -2,6-diphenylthiapy ryl i u m-perchJorat

49 2,4,6-tri (4-methoxyphenyl) thiapyrylium perchlorate

50 2,6-bis (4-ethylphenyl) -4-phenylthiapyrylium perchlorate

51 4- (4-amyloxyphenyl) -2,6-bis (4-ethylphenyl) thiapyrylium perchlorate

52 6- (4-Dimethylaminostyryl) -2,4-diphenylthiapyrylium perchlorate

53 2,4,6-triphenylthiapyrylium fluoroborate

54 2,4,6-triphenylthiapyryIium sulfate

55 4- (4-Methoxyphenyl) -2,6-diphenylthiapyryli fluoroborate

56 2,4,6-triphenylthiapyrylium chloride

57 2- (4-amyoxyphenyl) -4,6-diphenylthiapyrylium fluoroborate

58 4- (4-Amyloxyphenyl) -2,6-bis (4-methoxyphenyl) thiapyrylium perchlorate

59 2,6-bis (4-ethylphenyl) -4- (4-methoxyphenyl) thiapyrylium perchlorate

60 4-anisyl-2,6-bis (4-n-amyloxyphenyl) thiapyrylium chloride

61 2 - [^, / 3-bis (4-dimethylaminophenyl) vinylene] -4,6-diphenylthiapyrylium perchlorate

62 6 - (/? - Ethyl-4-dimethylaminostyryl) -

2,4-diphenylthiapyrylium perchlorate

63 2- (3,4-diethoxystyry]) -4,6-diphenylthiapyrylium perchlorate

64 2,4,6-trianisy thiapyrylium perchlorate

65 6-ethyl-2,4-diphenylpyrylium fluoroborate

66 2,6-bis (4-ethylphenyl) -4- (4-methoxyphenyl) thiapyrylium chloride

67 6- [y3, / 3-bis (4-dimethylaminophenyl) vinylene] -2,4-di (4-ethylphenyl) pyrylium perchlorate

68 2,6-bis (4-amyloxyphenyl) -4- (4-methoxyphenyl) thiapyrylium perchlorate

69 6- (3,4-diethoxy - /? - ethylstyryl) -2,4-diphenylpyrylium fluoroborate 70 6- (4-methoxy - /? - ethylstyryl) -2,4-diphenyl-

pyrylium fluoroborate

71 2- (4-Ethylphenyl) -4,6-diphenylthiapyrylium perchlorate

72 2,6-Diphenyl-4- (4-methoxyphenyl) thiapyrylium perchlorate

73 2,6-Diphenyl-4- (4-methoxyphenyl) thiapyrylium fluoroborate

74 2,6-bis (4-ethyIphenyl) -4- (4-n-aniyloxyphenyl) thiapyrylium perchlorate

75 2,6-bis (4-metnoxyphenyl) -4- (4-n-amyloxyphenyl) lhiapyrylium perchK advice

76 2,4,6-tris (4-methoxyphenyl) thiapyrylium fluoroborate

77 2,4-Diphenyl-6- (3,4-diethoxyslyryl) pyrylium perchlorate

78 4- (4-Dimethylaminophenyl) -2-phenylbenzo (b) - ^ao selenapyrylium perchlorate

79 2- (2,4-Dimethoxyphenyl) -4- (4-dimethylaminophenyl) benzo (b) selenapyrylium perchlorate

80 4- (4-Dimethyarninophenyl) -2,6-diphenylselenapryrylium perchlorate

^a5 81 4- (4-Dimethylaminophenyl) -2- (4-ethoxyphenyl) -6-phenylselenapyrylium perchlorate

82 4- [4-bis (2-chloroethyl) aminophenyl] -2,6-diphen.yiselenapyrylium perchlorate

83 4- (4-Dimethylaminophenyl) -2,6-bis (4-ethylphenyl) selenapyrylium perchlorate

84 4- (4-Dimethylamino-2-methylphenyl) -2,6-diphenylselenapyrylium perchlorate

85 3- (4-Dimethylaminophenyl) naphtho (2, l-b) selenapyrylium perchlorate

86 4- (4-Dimethylaminostyryl) -2- (4-methoxyphenyl) benzo (b) selenapyrylium perchlorate

87 2,6-Di (4-diethyIaminophenyl) -4-phenylselenapyrylium perchlorate and

88 4- (4-Dimethylaminophenyl) -2- (4-ethoxyphenyl) -6-pheny] thiapyrylium nuoroborate

The use of pyrylium dye salts of the general formula has proven to be particularly advantageous:

ry

proven, in which: R ₁ and R _{2 are} optionally substituted phenyl radicals which, if they are substituted, have at least one substituent consisting of an alkyl radical having 1 bi carbon atoms or an alkoxy radical having 1 bi carbon atoms, R _{3 is} an alkylamino-substituted, given if also dialkylamino- or haloalkylamino-substituted phenyl radical with an alkyl component having 1 to 6 carbon atoms, X is an oxygen or sulfur atom and Z ~ is an anion of the meaning given.

To carry out the process of the invention, a wide variety of customary known electrical

insulating, film-forming polymeric binders can be used, e.g. B. polycarbonates and polythiocarbonates, Polyvinyl ether, polyester, poly - \ - olefins, phenolic resins and the like. Mixtures can also be used such polymers. Suitable polymers of this type have a twofold function, namely they participate in the formation of the dye aggregates, and they also act as binders, which provide an adhesion cause between the photoconductive layers and the support. Typical suitable polymers Binders are listed in Table II below.

connection
No.

connection

No.

Table 11

Name of the polymers

1 polystyrene

2 polyvinyl toluene

3 polyvinyl anisole

4 polychlorostyrene

5 poly-methylstyrene

6 polyacenaphthalene

7 poly (vinyl isobutyl ether)

8 poly (vinyl cinnamate)

9 poly (vinyl benzoate)

10 poly (vinyl naphthoate)

11 polyvinyl carbazole

12 poly (vinylene carbonate)

13 polyvinyl pyridine

14 poly (vinyl acetate)

15 poly (vinyl butyral)

16 poly (ethyl methacrylate)

17 poly (butyl methacrylate)

18 poly (styrene-co-butadiene)

19 poly (styrofoam-co-methyl methacrylate)

20 poly (styrene-co-ethyl acrylate)

21 poly (styrene-co-acrylonitrile)

22 poly (vinyl chloride-co-vinyl acetate)

23 polyvinylidene chloride-co-vinyl acetate)

24 poly (4,4'-isopropylidenediphenyl-co-4,4'-isopropylidene-dicyclohexyl carbonate)

25 poly [4,4'-isopropylidenebis (2,6-dibromophenyl) carbonate]

26 poly [4,4'-isopropylidene-bis (2,6-dichlorophenyl) carbonate]

27 poly [4,4'-isopropylidene-bis (2,6-dimethylphenyl) carbonate]

28 poly (4,4'-isopropylidenediphenyl-co-1,4-cyclohexyldimethyl carbonate)

29 Poly (4.4'-Isopropylidenediphenylterephthalatco-Isophtha ^ at)

30 poly (3,3'-ethylenedioxyphenylthiocarbonate)

31 poly (4,4'-isopropylidenediphenyl carbonate co-terephthalate)

32 poly (4,4'-isopropylidenediphenyl carbonate)

33 poly (4,4'-isopropylidenediphenylthiocarbonate)

34 poly (2,2-butane-bis-4-phenyl carbonate)

35 poly (4,4'-isopropylidenediphenyl carbonate block ethylene oxide)

36 poly (4,4'-isopropylidenediphenyl carbonate block tetramethylene oxide)

37 poly [4,4'-isopropylidene bis (2-methylphenyl) carbonate]

38 poly (4,4'-isopropylidenediphenylco-1,4-phenylene carbonate)

39 poly (4,4'-isopropylidenediphenylco-1,3-phenylene carbonate)

Name of the polymers

40 poly (4,4'-isopropylidenediphenyl »co-4,4'-diphenyl carbonate)

41 poly (4,4'-isopropylidenediphenyl-co-4,4'-oxydiphenyl carbonate)

42 poly (4,4'-isopropylidenediphenyl-co-4,4'-carbonyldiphenyl carbonate)

43 poly (4,4'-isopropylidenediphenyl-co-4,4'-ethylenediphenyl carbonate)

44 poly [4,4'-methylenebis (2-methylphenyl) carbonate]

45 poly [l, l- (p-bromophenylethane) bis (4-phenyl) carbonate]

46 poly [4,4'-isopropylidenediphenyl-co-sulfonylbis (4-phenyl) carbonate]

47 poly [l, l-cyclohexane bis (4-phenyl) carbonate]

48 poly (4,4'-isopropylidenedipnenoxydimethylsilane)

49 poly [4,4'-isopropylidene bis (2-chlorophenyl) carbonate]

50 poly [\, \, \ ', \' - tetramelhyl-p-xyryIolbis (4-phenylcarbonate)]

51 poly (hexafluoroisopropylidene-di-4-phenyl carbonate)

52 poly (dichlorotetrafluoroisopropylidene di-4-phenyl carbonate)

53 poly (4,4'-isopropylidenediphenyl-4,4'-isopropylidenedibenzoate)

54 poly (4,4'-isopropylidene dibenzyl-4,4'-isopropylidene dibenzoate)

55 poly (4,4'-isopropylidene-di-1-napthyl carbonate)

56 poly [4,4'-isopropylidene-bis (phenoxy-4-phenylsulfonate)]

57 acetophenone formaldehyde resin

58 poly [4,4'-isopropylidene-bis (phenoxyethyl) -co-ethylene terephthalate]

59 phenol-formaldehyde resin

60 polyvinyl acetophenone

61 chlorinated polypropylene
62 chlorinated polyethylene

63 poly (2,6-dimethylphenylene oxide)

64 poly (neopentyl-2,6-naphthalenedicarboxylate)

65 polyethylene terephthalate-co-isophthalate)

66 polyil ^ -phenylene-co-l.S-phenylene succinate) - 45 67 poly (4,4'-isopropylidenediphenylphenylphosphonate)

68 poly (m-phenyl carboxylate)

69 poly (1,4-cyclohexanedimethyl terephthalate-co-isophthalate)

70 poly (tetramethylene succinate)

71 poly (phenolphthalein carbonate)

72 poly (4-chloro-1,3-phenylene carbonate)

73 poly (2-methy 1-1,3-phenylene carbonate)

74 poly (1,1-bi-2-naphthylthiocarbonate)

75 poly (diphenylmethane-bis-4-phenyl carbonate)

76 poly [2,2- (3-methylbutane) bis-4-phenyl carbonate]

77 poly [2,2- (3,3-dimethylbutane) bis-4-phenyl carbonate]

78 poly {l, l- [l- (l-naphthyl)] bis-4-phenyl carbonate} 79 poly [2,2- (4-methylpentane) bis-4-phenyl carbonate]

80 poly [4,4 '- (2-norbornylidene) diphenyl carbonate]

81 poly [4,4 '- (hexahydro-4,7-methanoindan-5-ylidene) -diphsnylcarbonat] and

82 poly (4,4'-isopropylidenediphenylcarbonate block-oxytetramethylene)

Compounds No. 28, 30 to 47, 49, 51, 53, and 76 to 82 of the given Table II have become

Z UlöU3Ö

Proven to be particularly advantageous for performing the method of the invention.

Preferably used polymeric binders are, for. B. also linear polymers or copolymers with recurring structural units of the general formula:

R ₇

c - Rs

in which:

R ₄ and R ₅ alone are hydrogen atoms, optionally substituted alkyl radicals, for example

Methyl, ethyl, propyl, isopropyl, butyl, tertiary butyl, Pentyl, hexyl, heptyl, octyl, nonyl, decyl or trifluoromethyl radicals, or optionally substituted aryl radicals of the phenyl and naphthyl series, their optionally present substituents z. B. from halogen atoms or alkyl radicals with 1 to Consist of 5 carbon atoms, or together to complete a cyclic hydrocarbon radical, z. B. a cycloalkane radical, for example

ίο a cyclohexyl radical, od; pure polycycloalkane radical, for example a norbornyl radical, required atoms, where the radicals R ₄ and R ₅ together have up to 19 carbon atoms, R ₈ and R ₇ hydrogen or halogen atoms, for example chlorine, bromine or iodine atoms, or Alkyl radicals having 1 to 5 carbon atoms and R _{8 is} a divalent radical of the formulas

O SO

O —C —Ο—, —O —C —O—, —C - O -,

CO-CH ₂ -,

O CH ₃

- C - O - CH-

O | O

- CH ₂ - O - C - O - or - O - P - O

I. ο ■ -

If the linear polymers are hydrophobic polycarbonates, then the use has been made of polymers with recurring structural units of the following formula:

R ₁ O

i
- R —C —R —O —C —O -

R ₅

in which R ₁ and R ^ have the meaning given and the radicals R are phenylene radicals which can be substituted by halogen atoms or alkyl radicals.

Compounds of the specified type are z. See U.S. Patents 3,028,365 and 3,317,466 described. The use of polycarbonates has proven to be particularly advantageous repeating structural unit an alkylidene diarylene component included, e.g. B. polycarbonates made using bisphenol A, e.g. B. those produced by ester interchange between diphenyl carbonate and 2,2-bis-4-hydroxyphenylpropane can be obtained. Connections of the specified type are z. See U.S. Patents 2,999,750, 3,038,874, 3,038,879, 3,038,880, 3,106,544, 3,106,545 and 3,106,546 and also in published Australian patent application no. 19 575/56.

To carry out the method of the invention has the use of film-forming polycarbonate of various types has proven to be expedient, where particularly advantageous results can be achieved with such commercially available polycarbonates, whose logarithmic viscosity number is 0.5 to 0.6. Furthermore, the use of high molecular weight Polymers, e.g. B. of high molecular weight bisphenol A polycarbonates have been shown to be advantageous. Such high molecular weight polymers are preferably those with a inherent viscosity of over 1, measured in 1,2-dichloroethane at a concentration of 0.25 g / 100 ml and a temperature of about 25 ° C. So z. B. the use of high molecular weight Polycarbonates advantageously help that in coating compositions with a comparatively high Content of Scnsibüisierungsfar towards the formation of the dye aggregates facilitated and a photoconductive composition with increased sensitivity is obtained.

The coating compositions obtained using the process of the invention are more suitable Way to increase the sensitivity and widen the spectral sensitivity range of various organic and inorganic photoconductors, both of the η-type and the p-type can belong. A typical suitable inorganic photoconductor is e.g. B. zinc oxide. Suitable are also numerous organic, z. B. also organometallic photoconductors that only have a low odet have practically no persistence of photoconductivity at all. Typical suitable such organometallic Connections are e.g. B. organic derivatives of metals from groups lila, IVa and Va des Periodic table, e.g. B. those which have at least one aminoaryl radical bonded to the metal atom. Typical suitable such organometallic compounds are, for. B. triphenyl-p-dialkylamino phenyl derivatives of silicon, germanium, tin and lead as well as tri-p-dialkylar.iinophenyl derivatives of Ar sen, antimony, phosphorus, bismuth, boron, aluminum gallium, thallium and indium. Suitable photoconductor of the specified type are e.g. B. in the German Auslegeschriften 1 772 775 and 1 943 387 described

15 ' 16

The use of R a hydrogen atom or a mononuclear atom has proven to be particularly expedient

, on organic photoconductors \ om so-called or polynuclear, either condensed or

"Organic Amint.vp" proved to be a common linear aromatic radical, for example a

structural feature at least one amino group on a phenyl, naphthyl or biphenyl radical, a sub-

Λ-iron. Typical suitable, when using the 5-substituted aromatic radical of the specified type,

The method of the invention spectrally sensitizable whose substituent is selected from an alkyl, alkoxy, acyl

Iranian photoconductors of the specified type are or nitro radical, or made of a poly | 4'-vinylphenyl) -

1. B. Arylamine compounds, for example (1) diaryl radical, which has a carbon atom of the phenyl radical

amines, such as B. diphenylamine, dinaphthylamine, is bonded to the nitrogen atom.

Ν, Ν'-diphenylbenzidine, N-phenyl-1-naphthylamine, ₁₀ The use has proven to be particularly advantageous

N-PhenyW-naphthylamine ^ N'-Diphenyl-p-phenylene- of photoconductors consisting of polyarylalkanes,

diamine. 2-carboxy-5-chloro-4'-methoxydiphenylamine, e.g. From U.S. Pat. No. 3,274,000 and U.S. Pat

p-anilinophanol. N, N'-di-2-naphthyl-p-phenylene French patent 1383 461 are known,

diamine, which is proven in US Pat. No. 3,240,597.

Written compounds and (2) triarylamines, i ₅ Such photoconductors can, for. B. from leuco bases

z. B. (a) non-polymeric triarylamines such. B. Tri- of diaryl or triarylmethane dye salts or

phenylamine, Ν, Ν, Ν ', Ν'-tetraphenyl-m-phenylenedi- 1,1,1-triarylalkanes, the alkane radical of which has at least two

amine, 4-acetyltriphenylamine, 4-hexanoytriphenyl carbon atoms, and tetraaryimethanes,

amine, 4-lauroyltriphenylamine, 4-hexyltriphenylamine, in which at least one of the to the alkane radical or

4-dodecyltriphenylamine, 4,4'-bis- (diphenylamino) - _2O methane residue bound aryl residues through an amino

benzil, 4,4'-bis- (diphenylamino) -benzophenone and group-substituted exist. The last two

(b) polymeric triarylamines, such as. B. Poly [N, 4 "- (N, N ', named photoconductor classes are not

N'-triphenylbenzidine)], polyadipyltriphenylamine, Po-leuco bases.

lysebacyltriphenylamine, polydecamethylene triphenyl The use has proven to be particularly advantageous

amine, poly-N- (4-vinylphenyl) -diphenylamine or poly-a ₅ of photoletters consisting of polyarylalkanes

N- (vinylphenyl) - \, V-dinaphthylamine. Further suitable the following general formula has been proven:
organic amine type photoconductors

z. In U.S. Patent 3,180,730. D.

As suitable I

Photoconductors have also come from the USA - 30 J - C - E

Patent 3,265,496 known compounds of the |

following general formula: G

R - [N - T -] _b Q AUA

in which:

'35 D, E and G aryl radicals of the phenyl and naphthyl

series, where at least one of the radicals D, E and G

proven, in which mean: is substituted by an amino group, and

T is a mononuclear or polynuclear, ent- J is a hydrogen atom, an alkyl radical or a

neither condensed nor linear divalent aryl radical of the phenyl and naphthyl series.

aromatic residue, ζ. B. a phenyl, naphthyl, 40 In the case of the central carbon atom

Biphenyl or binaphthyl radicals or a substituted aryl radicals are preferably

tute divalent aromatic radical of the an-phenyl radicals, but it can also be naphthyl radicals

given type, whose substituent z. B. act from one. The aryl radicals can also be used in ortho-,

Acyl radical having 1 to about 6 carbon atoms, for example meta- or para-position, be substituted, for. B. by

as an acetyl, propionyl or butyryl radical, 45 alkyl or alkoxy radicals with usually 1 to 8 carbon

an alkyl radical with 1 to about 6 carbon atoms, carbon atoms, hydroxy radicals or halogen atoms,

for example a methyl, ethyl, propyl or substituted aryl radicals which are particularly advantageous

Butyl radical, an alkoxy radical with 1 to about 6 carbons, pheny radicals substituted in the ortho position

material atoms, for example a methoxy, ethoxy, had. The aryl radicals present can also

Propoxy or pentoxy radical, or from a nitro group 50 linked to one another or cyclized, e.g. More colorful

consists, formation of a fluorene ring.

M a mononuclear or polynuclear, ent- The present in at least one of the aryl radicals

neither fused nor linear monovalent amino substituents can be represented by the formula

aromatic residue, ζ. Β. a phenyl, naphthyl L

or biphenyl radical, or a substituted monovalent 55

aromatic radical of the specified type, whose - N

Substituent e.g. B. from an acyl radical with 1 to about L.
6 carbon atoms, for example an acetyl,

Propionyl or butyryl radical, can be reproduced from an alkyl radical with, where L alone is one

1 to about 6 carbon atoms, for example a 60 alkyl radical with usually 1 to 8 carbon atoms,

Methyl, ethyl, propyl or butyl radical, an alkoxy, a hydrogen atom or an aryl radical, or both

radical with 1 to about 6 carbon atoms, for example radicals L together to complete a

a methoxy, propoxy or pentoxy radical, or heterocyclic amine radical with usually 5 to

consists of a nitro group, 6 ring atoms, e.g. B. a morpholino, pyridyl or

Q represents a hydrogen or halogen atom or an atom required for a pyrryl radical,

aromatic amino radical, e.g. B. one of the all- Polyarylalkanes have proven to be particularly advantageous

common formula MNH -, the given formula proved in the at least

h - ■ an integer from 1 to 12 and one of the radicals D, E or G is a p-dialkylamino

17 - ¹⁸

represents phenyl radical. In the formula given, J stands for aminophenyl, dimethylaminophenyl or phenyl radical for an alkylresi, this can be, for. B. mean in advantageous.

Way to be an alkyl radical with 1 to 7 carbon atoms. Further suitable photoconductors when carrying out

Typical suitable polyarylalkane photoconductors are the dye aggregate of the method of the invention

£ .3. the 5-containing coating masses listed in the tubular table III are incorporated

Links. can, are z. B. Rhodamine B, malachite green,

Crystal violet, phenosafranine, cadmium sulfide, cad

Table III mium selenide, parachloronil, benzil, trinitrofluorenone

Connection . and tetranitrofluorenone.

No. Designation ^ Typical suitable photoconductors and photoconductive ones

1 4,4'-benzylidene-bis (N, N-diethyl-m-toluidine) materials, whose sensitivity, sensitization

2 ^ "- Diamino ^ dimethylamino and / or regeneration properties with the help of the 2 ', 2 "-dimethyltriphenylmethane according to the invention according to the resulting heterogeneous mass».

3 ^ "- BistdiäthylaminoH.o-dichloro- can be improved, for example in the following 2 ', 2 "-dimethyltriphenylmethane 15 Table IV.

4 4 ', 4 "-Bis (diethylamino) -2', 2" -dimethyldiphenyl- wrote,
naphthylmethane Table IV

5 2 ', 2 "-Dimethyl-4,4', 4" -tris (dimethylamino) - USA.Patent No.

triphenylmethane 3,037,861 3,158,475 3,041,165 3 161505

6 4 ', 4 "-bis (diethylamino) -4-dimethylamino- ^ao 3,066,023 3,163,530 3,072,479 3,163,531 2', 2" -dimethyltriphenylmethane 3,047,095 3,163,532 3,112,197,3 169,060

7 4 ', 4 "-bis (diethylamino) -2-chloro-2', 2" -dimethyl-3133022 3 174 854 3 144 633 3 180 729 4-dimethylaminotriphenylmethane 3P2 435 3,180,730 3,127,266 3,189,447

8 4,4 "-bis (diethylamino) -4-dimethylamino- 3 130 046 3 206 306 3 131060 3 240 597 2,2 ', 2" -trimethyltriphenylmethane 35 _{3] 39 338} 3 257 202 3139 339 3 257 203

9 4 ', 4 "-Bis (dimethylamino) -2-chloro-2', 2" - 3,140,946 3,257,204 3 141770 3,265,496 dimethyltriphenylmethane 3 _{] 48,982 3,265,497 3,155,503 3,274,000}

10 4 ', 4 "-bis (dimethylamino) -2', 2" -dimethyl-

4-methoxytriphenyimethane Are the when using the method of

11 bis (4-diethylamino) -l, l, l-triphenylethane 30 Invention accruing coating compounds Photo-

12 bis (4-diethylamino) tetraphenylmethane head added, so the use of

13 4 ', 4 "-bis (benzylethylamino) -2', 2" -dimethyI- organic, e.g. B. organometallic photoconductors in triphenylmethane concentrations of at least about 0.5 weight

14 4 ', 4 "-bis (diethylamino) -2', 2" -diethoxytriphenyl percent, based on the total amount of the bemethane 35 layer solids added to the solvent, as

15 4,4'-bis (dimethylamino) -l, l, l-triphenylethane proved to be useful. The upper limit of the concentration

16 l- (4-N, N-dimethylaminophenyl) -l ₅ l-diphcnyl- trationsbereich on the existing photoconductor can be very different from ethane and up to 99 percent by weight,

17 4-dimethylaminotetraphenylmethane and added to the total amount of solids.

18 4-Diethylaminotetraphenylmethane 40 When using a photoconductor, it has turned out to be be

proven to be particularly advantageous to

When using the method of the invention trations of about 10 to 80 percent by weight to be employed The 4-diarylamino turns are also photoconductors. Of course, however, as already substituted chalcones. Typical suitable comments that are made when using the method of Linkages of this type are non-polymeric ketones containing dye aggregates with a low molecular weight of the following formula: heterogeneous coating compounds even without additives

a photoconductor for the production of photoconductive

R layers are used.

¹ - To carry out the method of the invention

N - - CH = CH - C - R _{2 S} o are the most diverse organic coating

R ₁ solvent can be used, e.g. B. liquid coals

hydrogen, which can be substituted, in particular

in which R ₁ and R _{2 are} optionally substituted phenyls, advantageously halogenated hydrocarbon radicals, and where R _{2 is} advantageously a solvent. Coating solvents with a phenyl radical of the formula 55 which are used to dissolve the

R applied sensitizing dye as well as to solution

■ - ■. ³ or at least to the high degree of swelling of the

^ N applied polymeric binders are capable. Further

* R ₁ has been found useful when used

60 solvents are volatile, preferably if they are

represents, in which R ₃ and R ₄ aryl radicals, aliphatic radicals have a boiling point of below about 200 ⁰ C, with 1 to 12 carbon atoms, for example alkyl radicals with The use of preferably 1 to 4 carbon atoms, or water solvents has been found to be particularly advantageous proven that halogenates mean short-term atomic atoms. chain alkanes with 1 to 3 carbon atoms

The use of 65 has proven to be particularly advantageous, for example the use of dichloro compounds of the general methane, dichloroethane, dichloropropane, trichloromic formula indicated, in which the radicals R _{1 are} optionally than, trichloroethane, tribromomethane ^ trichloromonosubstituted phenyl radicals and R _{2 is} a diphenyl - fluoromethane, trichlorotrifluoroethane and the like, furthermore

J9

of halogenated Beiizo compounds, ζ. B. Chiorobenzene, Bromobenzene, dichlorobenzene and the like mixed solvents can also be used.

To carry out the method of the invention, the concentration of sensitizing dye, which is initially practically completely dissolved in an organic coating solvent, very much may be different depending on the solubility of the dye used in the one used Solvent and the desired dye concentration in the coating material to be formed. Comparatively high dye concentrations generally lead to photoconductive coating compositions with a comparatively high electrophotographic sensitivity. It has been found to be functional found the sensitizing dyes in concentrations of about 0.5 to 30 percent by weight, based to the total amount of solids added to the coating masses.

For performing the method of the invention a sensitizing dye is at least mixed with the coating solvent and the resulting mixture stirred at about room temperature, for example at 2O ⁰ C for so long, is completely dissolved until the dye. As a rule, it proves sufficient to stir the mixture of dye and solvent for up to about 2 to 3 hours in order to achieve a practically complete solution of the dye. For convenience, the dye is usually dissolved at about room temperature, but elevated temperatures can be used to increase the rate of dissolution. Of course, when using elevated temperatures, care must be taken not to use temperatures which are higher than the boiling point of the solvent used. The period of time during which stirring can be very different and depends on the dye concentration used and on the total amount of solution to be prepared . After the dye has dissolved, the solution obtained is mixed with the polymeric binder and stirred further, stirring for 2 to 3 hours having proven to be sufficient as a rule. A photoconductor is then optionally added and the solution containing the specified components is briefly stirred. The coating composition obtained in this way can be used for coating substrates without further additional treatment and is applied to a suitable substrate. The layer obtained is then dried in a conventional manner. The drying can e.g. B. be done in such a way that the solvent is simply allowed to evaporate at room temperature and normal pressure. Furthermore, the resulting layer can be dried with the aid of circulating air or by moderate heating, care being taken to avoid damage caused by heat. The photoconductive layer containing dye aggregates obtained in this way by simple coating and drying does not require any further aftertreatment.

The photoconductive layers applied to the support according to the process of the invention can have the most varied of strengths. As a rule, photoconductive layers have proven to be useful proven to have a thickness of about 10 to 1250 μ, preferably from about 50 to 750 μ. However, useful results are also achievable outside the specified range. To carry out the method of the invention The most varied of customary known electrically conductive layers can be used, ζ. 3. Substrate made of paper with a relative humidity of more than 20%, made of aluminum foils and paper Laminates, made of metal foils, e.g. aluminum foils and zinc foils, of metal plates, for example aluminum, copper, zinc, brass and galvanized plates, made on paper vapor-deposited metal layers made of z. B. silver, nickel, aluminum and the like., Or from the usual known photographic supports based on

Cellulose acetate, polystyrene, poly (ethylene terephthalate) and the like. Furthermore, electrically conductive substances, such as. B. nickel, in a vacuum on a transparent substrate are vapor-deposited in the form of so thin layers that electrophotographic recording materials can be produced, which can optionally be exposed from either side. A special one advantageous electrically conductive substrate can be produced in such a way that a made of z. B. Poly (Äthjlenterephthalat) existing support is provided with a photoconductive layer, which a semiconductor dispersed in a resin, e.g. B. copper (I) iodide contains. Conductive layers of the specified Type, optionally in combination with insulating barrier layers, are z. B. U.S. Patents 3,245,833 and 3,428,451. Suitable electrically conductive layers are, for. 3. also from the sodium salt of a carboxy ester lactone of maleic anhydride and a vinyl acetate polymer manufacturable. Conductive layers of the specified type and advantageous processes for their Production are z. In U.S. Patents 3,007,901 and 3,267,807.

The method of the invention comprises first placing the sensitizing dye in a coating solvent is practically completely dissolved before the binder and optionally a photole.ter Beigemkeht, has, in addition to the numerous advantages already listed, also the surprising ones Advantage that with its help electrophotographic recording materials in only one coating process can be produced with photoconductive layers which have a higher dye concentration as comparable layers which can be produced by conventional known processes. In the the higher dye concentration present in the photoconductive layers obtained according to the invention advantageously to a higher electrophotographic sensitivity. So shows z. B. that the electrophotographic recording materials which can be produced by the process of the invention only one photoconductive layer containing dye are practically as sensitive as known ones electrophotographic recording materials with several dye-containing layers for their production ζ. B. by the specified known method (see. Belgian patent 729 078) a first dye-containing photoconductive layer or a further dye layer is applied. from Another advantage is that, according to the process of the invention, highly sensitive electrophotographic recording materials can be produced without the need for a second coating operation, as well as that the quality and sensitivity of the

21 - ²²

In the case of the so-called fiow, which are advantageously controllable in accordance with After the development, the developer part no electrophotographic surface that can be produced using the imaging process of the invention which the developer particles are made of, as can be seen from resenerierunesttsts, in which the test objects are charged repeatedly from an electrically polishing liquid and the existing carrier material is incorporated. Further development processes of the specified type to be achieved according to the invention are advantages, for example the high sensitivity of the possibility of being highly sensitive and are described in numerous literature references for electrophotographic recording materials, e. B. in the USA. Patent 2 907 674 depending on the crystalline structure of the for Her- and the Australian patent step 21- Mi.
Position of the coating compounds used to produce bilizing dyes in a simple manner when using dry development processes. is a visible, permanent "image mostly mn were already mentioned with the help of an electrostatically attractable particle

The 15 holding developers which can be produced by the method of the invention, one component of which consists of electrophotographic recording materials and a low-melting resin, are used for carrying out the usual known ones. If the electrical image, which requires electrically conductive layers with such a developer powder, is heated, the photographic process melts or softens. So they are resin, possibly with penetration into the film. B. to carry out the so-called xero- 20 surface, so that in this way a permanent araphic process can be used in which the developer powder adheres to the surface of the electrophotographic recording material in the photoconductive layer. The surface charge formed on the photoconductive layer is optionally stored in the dark and provided with an electrostatic charge by applying a charge image to a second carrier material, e.g. B. is exposed to a corona discharge. The paper-based in this way is transferred, whereupon the uniform image-receiving material imparted to the photoconductive layer by development under surface charge remains in the dark because of the practically iso-melting of the developer, the finished copy is produced. Processes of the specified type are known, ie because of the low conductivity of this layer, and are described in numerous literatures and obtained in the dark. The on the surface of the 30 z. B. in US Pat.

according to customary known exposure methods, the following examples are intended to illustrate the invention in greater detail

explain, for example, with the help of a contact printing technique.

or by lens projection of an image, selectively 35 B e i s ρ i e 1 1

dissipated from the surface of the layer, so that in (comparative example)

the photoconductive layer has a latent electro

static image is generated. As a result of the exposure of the electrophotographic recording material WUR film surface which is used as a comparative sample, an electrostatic charge forms from 85 parts by weight of dichloromethane and 9 weighting patterns, since the bisphenol-A polycarbonate distributed on the photoconductor In a mechanical striking light energy leads to the fact that the electro mixer for 2 hours at 2O ⁰ C stirred rapidly until the static charge "in the resin hit by the light was completely dissolved. The solution obtained was proportional to the intensity of the incident areas with 6 Parts by weight of the photoconductor 4,4'-di-radiation is removed from the film surface. 45 ethylamino-2,2'-dimethyltriphenymethane are added,

The charge pattern formed in the exposure whereupon at about 2O ⁰ C for 30 minutes further stirring is then developed or on the surface was one. Thereafter, 0.3 weight receiving material was transferred to the mixture and developed there. parts 4- (4-dimethylaminophenyl) -2,6-diphenylthiapyry-The development takes place by visualization. liumfluoroborat added, whereupon the resulting either the charged or the uncharged solution was stirred for 2 hours. The latent image obtained by treatment with a coating compound was then coated with an optically dense particle known as an electrostatically attractable, optically dense particle called "Fulflo cartridge". The electrostatically attractable 5-jx fiber filter cartridge filters.
Developer particles can be in the form of a dust. B. powder, or in the form of a resinous 55 poly (ethylene terephthalate) film existing layer carrier incorporated pigment, ie toner, carrier, which is electrically present with a vapor-deposited thin. Such a toner is applied to the conductive nickel layer, developing latent electrostatic image preferentially in such a way that the measured after drying is applied with the aid of a magnetic brush, to thickness of the layer obtained about 10 to 12 microns the development of full areas to guarantee. 60 was. The optical density of the er method for the production and use of supplies for electrophotographic recording directions on the basis of magnetic brushes to the terials at 600 and 690 ηΐμ was then measured. Thereafter, application of toners was z. B. in the USA - the recording material under a Coronaent patent specification 2 786 439, 2 786 440, 2 786 441, charge electrostatically charged until the 2 811 465, 2 874 063, 2 984 163, 3 040 704, 3 117 884 65 measured with the help of an electrometer sample as well as the Reissue patent specification 25 779 described. surface potential was about 600 volts. The charged one

The electrostatic latent image can then be given a recording material

if also with the help of liquid developers, gray wedge with graduated density and a

23 24

Short-wavelength radiation was rapidly agitated. A shear treatment was the reference filter with 30% permeability at 600 mμ of the solution, but not subjected.
3000 ° K tungsten light source exposed. The coating compound obtained was then

such exposure, the surface potential is applied by the method described in Example 1 to the recording material under each step of the 5 a support of the specified type, gray scale from its original potential K ₀ whereupon the resulting electrophotographic up is reduced to a lower potential V , the drawing material, as in Example 1, tested for the exact value of the optical density and sensitivity of the area concerned, the amount of exposure actually encountered, measured. The results obtained are dependent on the meter-candle-seconds indicated below. Table V lists the potentials. The results show the exposed material were overall that both the optical density counted and the electrical measurement and the results obtained graphically Removing sensitivity are improved over a by for each exposure step, the upper electrophotographic recording material which flächenpotenlial V vs. log exposure was applied according to customary known methods in compliance. The actual positive or negative sensitivity of the tested electrophotographic component was produced in the usual order of addition.
The resulting electrophotographic record can then be expressed as the reciprocal value of the exposure which the recording material could advantageously require to reduce the surface potential to a charged, exposed and arbitrarily set value using liquid. In the prior developers of the case in U.S. Patent 2,907,674, unless otherwise specified, the type described for producing qualitative, the positive high quality visible images determined in the manner indicated, or negative sensitivity, is expressed as that . .

Value 10 ⁴ divided by the exposure in meter example 4

Candle seconds, which are used to reduce the 35 (comparative example)

brought surface potential from 600 V to 50 V The procedure described in Example 3 was

is required. Those determined in this way repeatedly with the exception that the poly sensitivities first are added as positive or negative meric binders to the coating solvent 50 V sag sensitivity. The added at and the resulting mixture for 2 hours the test was stirred in the manner indicated, whereupon the sensitizing dye provided, as a comparison sample, was added electrically and stirred again for 2 hours, photographic recording material. The solution obtained was then subjected to the photographic results, namely, its optical density and electrical conductor are offset, whereupon the resulting mixture is renewed trophotographic sensitivity, have been stirred in for 30 minutes below. That way it was given in Table V. 35 obtained a coating solution which, according to the im

Example 1 described method on a layer

Example ζ carrier of the specified type has been applied,

(Comparative example) whereupon the electrophotographic image obtained

After the procedure given in Example 1, draw material in the manner indicated a coating compound was produced with the exception of 4 «electrical sensitivity and optical density, that 10% of the obtained was tested before filtering.

Solution in a high-speed shear mixer Following the procedure given, several

and exposed to a shear electrophotographic recording material for 20 minutes were exposed. The one of the shear effect, the sensitivity of which was measured in each case, The portion of the solution subjected to it was then given a value of 45. The results obtained differed greatly from those obtained 90% of the untreated solution remained from each other and revealed that some of the reunited. The obtained electrophotographic obtained electrophotographic recording material After the materials in Example 1, the sensitivity was much lower methods described on optical density and than others, produced by the same method electrophotographic sensitivity tested. The 50 had recording materials. This results in, The results obtained are in that given below that it is not sufficient to use one in a conventionally known manner Table V listed. The results show that a solution of sensitizing dye and polymer! the shear treatment to establish both the optical density and the binder before the photoconductor is in the also the electrophotographic sensitivity obtained solution is dissolved, but that only after be raised. 55 the method of the invention in compliance with

well-defined order of adding the an example 3 individual components coating compounds can be produced

Using those given in Example 1, the electrophotographic recording components were produced according to the method of materials with improved sensitivity and finding in such a way a coating composition of optical density,
put that first the sensitizing dye. ic

added to the coating solvent and e 1 s ρ 1 e 1 3

the mixture obtained until the dye dissolves (comparative example)

was stirred for about 2 hours. The procedure described in Example 1 was then followed

the solution obtained with the polymeric binder 65 was mixed using twice the amount of Sensi, followed by stirring for a further 2 hours. bilizing dye herge-zu a coating compound The resulting solution was finally made into and converted to an electrophotographic photoconductor added, whereupon drawing material was processed again for another half an hour. The results

the electrophotographic tests are in the below given in Table V. The results show that the optical density and electrical sensitivity compared to the electrophotographic recording material produced according to Example 1 are only slightly increased, from which it follows that when using the specified method hardly more dye is dissolved than when using the method described in Example 1.

Example 6
(Comparative example)

Using a coating solution prepared according to Example 5, that in Example 2 described procedure repeated. That using a coating compound, 10% of which is one The electrophotographic recording material obtained was subjected to shear stress tested for optical density and electrical sensitivity according to the method described in Example 1. The results obtained are shown in Table V below. The results show that the optical density and electrophotographic sensitivity are only slightly greater are than in that prepared according to Example 2 using only half the amount of sensitizing dye electrophotographic recording material. It can also be seen that using electrophotographic coating composition prepared from the shear pretreatment Recording material has an optical density and electrical sensitivity which are not greater are as those of the method of the invention according to Example 3 using only the half the amount of the sensitizing dye prepared electrophotographic recording material.

Example 7

The method described in Example 3 was followed, using twice the amount Sensitizing dye a coating compound is produced and applied to a layer support, whereupon the obtained electrophotographic recording material for optical density and electrical Sensitivity has been tested. The results obtained are shown in Table V below. The results show that, according to the method of the invention, using twice the amount Sensitizing dye almost twice as high an electrophotographic sensitivity is achieved.

The electrophotographic obtained in the investigation of Examples 1 to 3 and 5 to 7 The results obtained from recording materials are listed in Table V below:

Table V Example 8

Optical density Photo sensitive example exposure
by an interference 600 Γημ 690 m | x filter on a lower one No. 0.52 0.50 Potential of -50 V 1 0.85 1.24 <50 2 0.91 1.55 800 3 0.58 0.52 900 5 0.87 1.57 <50 6th 1.08 > 4.00 900 7th 1600

The procedure described in Example 3 was repeated except that the sensitizing dye was used 4- (4-dimethylaminophenyl) -2,6-diphenylthiapyrylium perchlorate was used. It spontaneous dye aggregate formation took place, which was complete after the addition of the polymeric binder was. The obtained electrophotographic recording material was made in the above manner tested. Advantageous results as in Example 3 were obtained accordingly.

Example 9 (comparative example)

The procedure described in Example 4 was repeated using twice the amount Sensitizing dye. The obtained electrophotographic recording material was tested for sensitivity and optical density tested. No clear results were obtained, so not It could be determined with certainty whether at least doubling the dye concentration

a slight increase in sensitivity and optical density can be achieved.

Example 10

The procedure described in Example 3 was repeated except that as the photoconductor 4-diethylaminotetraphenylmethane and as a sensitizing dye 4- (4-Dimethylaminophenyl) -2,6-diphenylthiapyryum perchlorate were used. Based on solids, the solution was 2 wt.

percent dye and about 37 weight percent photoconductor as well as 100 weight percent missing Amount of binder of the type described in Example 1 added. It was first the dye and then the binder and the photoconductor dissolved, whereupon the resulting coating solution after the procedure described in Example 1 at a coating block temperature of about 15 ° C a support of the specified type was applied. The obtained electrophotographic

Recording material was tested for electrical sensitivity. It was found that the negative 100 V toe sensitivity was about 1100. Thereafter, the recording material was under Use of 100 cycles on regeneration

properties tested. To carry out this test, the film sample was made according to the example! described Process subjected to a corona discharge and then exposed, whereupon they one Flood or extinction exposure was exposed with the entire cycle within 3 seconds. The specified treatment cycle was repeated 100 times, whereupon the results obtained when measuring the surface charge of the recording material examined

after the first and the 100th cycle were compared. It was found that the maximum No surface charge of the photoconductive layer after the 100th cycle compared to the first cycle had fallen off.

The obtained electrophotographic recording material was then used to produce a visible image charged, exposed and developed by the method described in Example 3.

27 28

Example 11 Example 1 consisted of the type described. The application the coating compound on the substrate

Following the procedure described in Example 10 was conducted at a coating block temperature of two photoconductive coating compositions were about made 15 ⁰ C. The obtained electrophotographic wherein as photoconductors for preparing the 5 recording material was after the first in the Example 10 coating composition 4,4 ', 4 "- Tris (diethyIamino) - method described was tested and it was found, tetraphenylstannane and, to make the second, the 100 volt negative sag sensitivity of coating weight was diphenyl-bis- (p-diethylaminophe-1800. To produce a visible image, nyl) stannane was used The first coating consisted of 2 parts of drawing material, based on solids, of about 60% by weight of dye, loaded, exposed and developed, based on solids,
percent from photoconductor and the remainder from binder,. ,
and the second coating consisted of 2 Ge Example 14
weight percent from dye, about 53 % from photo After the method described in Example 3 head and the remainder of the binder in Example 1 15 were initially 0.375 g of sensitizing dye of the type described. type described in Example 3 in 42.5 g of methylene

Each of the two coating compounds obtained chloride dissolved with stirring for about 2 hours,

were after the procedure described in Example 1. After dissolving the dye, the resulting solution

drive at a coating block temperature of 4.5 g of poly (4,4'-isopropylidene diphenyl carbonate

about 18 ⁰ C applied to a layer support. The 20 block oxytetramethylene) are added with stirring and

obtained two electrophotographic recordings for about 2 hours until the poly-

Application materials 1 and 2 were then stirred after the merisate. Thereafter, the obtained solution became

Method described in Example 10 to electrical with 3 g photoconductor of the method described in Example 1

Sensitivity tested. Type added, whereupon the resulting mixture a

The results obtained showed that the sample 25 further ¹ hour, it was stirred for _Z2. The received

No. 1, a 100 volt negative sag sensitive coating, was then applied to an electrically

speed of about 3500 and sample no. 2 has a negative conductive layer support of the one described in example 1

100 volt sag sensitivity of about 1700 benen type applied to what the layer obtained

exhibited. The two recording materials were left to dry.

the then described in Example 1 30 The electrophotographic record obtained

Process charged, exposed and developed. It was recorded in the dark on a surface

clearly visible images were obtained. potential of 600 V and after the im

Example 1 described method exposed, whereupon

B e i s ρ i e 1 12 it has been tested for sensitivity. The received

35 positive or negative sensitivities were made

According to the method described in Example 10, expressed as the value 10 ⁴ divided by the was an electrophotographic recording exposure in meter-candle-seconds, which was made to the material using a reduction of the OOV amount of the surface potential of the coating composition, based on solids content, to a A potential of 500 V (100 volt shoulder to 2 percent by weight from dye of the type described in Example 10 4 ° sensitivity) or a potential of 100 V to about 62 percent by weight (100 volt sag sensitivity) is required. p-Diethylaminophenylgerman as a photoconductor and the results obtained showed that the positive to the remaining portion consisted of binder of the 3200 shoulder sensitivity in Example 1, the positive type written through. The application of the slope sensitivity 320, the negative shoulder tempering coating compound on a layer sensitivity 2800 and the negative sag sensitivity carrier were carried out according to the sensitivity 500 described in Example 1. After the erase exposure procedure was carried out at a coating block temperature of, the resulting electrophotographic was allowed to rise to about 15 ° C. The electrophotographic drawing material obtained for the production of a visible recording material was charged, imagewise exposed and developed by the method described in Example 3 using the method described in Example 3.
tested. The results showed that the negative. .
100 volt sag sensitivity was about 480. Example 15
With the aid of the recording material obtained. This example shows that clearly visible images according to the invention were obtained when, after setting up an electrophotographic recording according to the method described in Example 1, the material was charged, exposed and developed using a coating. solution that only has a sensitizing dye and

contains a binder and is free of photoconductor.

Example 13 To prepare the coating solution,

initially 0.16 g 4- (4-dimethylaminophenyl) -2,6-di-

According to the method described in Example 10, 60 phenyl thiapyrylium fluoroborate in 18.2 g of dichloro

an electrophotographic recording methane was dissolved with stirring for about 3 hours. the

material prepared using a solution obtained was with 4.0 g of a bisphenol

coating compound, which, based on the addition of the loading A polycarbonate, whereupon the obtained color

Coating solvent added solids, stirred into fabric-binder solution for about 18 hours

2 percent by weight of the dye in Example 10 65 was.

of the type described and about 40 percent by weight. The resulting coating solution was then

from photoconductor of the type described in Example 1 at 18.3 ⁰ C to a polyethylene terephthalate

consisted, with the remainder of the binder of the existing film in the substrate, with a

ν,

Vaporized conductive nickel layer was applied. The thickness of the dry photoconductive layer was about 12 to 14 microns. A sample portion of the obtained electrophotographic recording material was charged under a corona discharge until the surface potential measured by an electrometer probe reached about 600 volts. The charged recording material was then subjected to 3000 ^G K tungsten light source exposed, and the loss of Oberfiächenpotential was measured as a function of exposure. The sensitivity measurement was carried out according to the method described in Example 1, with the exception that the sensitivity determination was based on a 100-volts shoulder sensitivity instead of, as in Example 1, a.; F, a 50-volt shoulder sensitivity.

The obtained results, which were obtained both in the positive as well as negative charge, are in the following table as a shoulder sensitivities (K ₀ -100 volts) and 100 volts slack sensitivities reproduced.

On another portion of the obtained recording material the optical density was measured and the results obtained are also shown in the following table.

Table Vl

Electric H- and D-Bmpf. (Schuller / 100 volt
Passage) pos.
360/9 neg.
360/16

Optical density 685 nm 600 nm 3.35 2.10

The results show that the cr obtained dye aggregates act as photoconductors, so that the inventive production of a electrophotographic recording material does not require the use of a separate photoconductor

ao is necessary. The high light absorption found at 685 nm and a microscopic one Examination of the recording material obtained revealed an extensive conversion of the material used Dye and binder in the inventiveO

recognize producible photoconductive dye-binder combination.

Claims (3)

Patent claims: 1. A method for producing an electrophotographic recording material from a electrically conductive support and at least one heterogeneous photoconductive layer, the from a continuous phase of a binder and a discontinuous phase with a content of at least one pyrylium, thiapyrylium or selenapyrylium sensitizing dye, which forms recognizable aggregates at 2500x magnification, consists of a sensitizing dye, binder and coating liquid containing solvent applied to the substrate and the layer obtained is dried, thereby characterized in that for the preparation of the coating liquid the sensitizing dye (s) ^) dissolved in the solvent, the binder added to this solution and the resulting The mass is intimately mixed before application to the substrate. 2. The method according to claim 1, characterized in that that a coating liquid is used which additionally contains a photoconductor, wherein the photoconductor is added to the coating liquid after the addition of the binder will. 3. Process according to Claims 1 and 2, characterized in that the sensitizing dye is used a selenapyrylium dye salt or a pyrylium or thiapyrylium dye salt of the formula