DE2018038A1 - Process for the production of an electrophotographic recording material - Google Patents

Description

EASTMN KODAK COMPANY, 3 ² O State Street, Rochester, New York State, United States of America

Method of making an electrophotographic

Recording material

The invention relates to a method for producing an electrophotographic recording material from an electrically conductive support and at least one heterogeneous photoconductive layer, consisting of a continuous Phase made up of a film-forming polymer and a discontinuous one Phase with an electrophotographic sensitizing dye that is magnified 2500 times the layer forms at least for the most part recognizable aggregates, the photoconductive layer having an absorption maximum which compared to the absorption maximum of one formed from the same dye and the same binder homogeneous flowable layer is shifted by Application of a coating composition of at least one sensitizing dye and an electrically insulating film-forming binder for the sensitizing dye on an electrically conductive substrate and drying the completed layer.

0098U / 162'3

BATH ORIGINAL

_ 2 -

K Electrophotographic recording materials and electrophotographic © Processes of the most varied types are known and are described in numerous literature references, e.g. in U.S. Patents 2,221,776; 2,277,013;

2,297,691; 2,357,809; 2,551,582; 2,825 814? 2,833,648;

3,220 32.4; 3 220 831 and 3 220 833. For producing pictures With the aid of electrophotography, an electrophotographic recording material with a normally insulating photoconductive layer is usually image-wise exposed to electromagnetic radiation to form a latent electrostatic charge image, whereupon the obtained latent image is converted into a visible, permanent image by customary known methods.

The use of an electrophotographic has proven to be particularly advantageous Proved recording material, the a photoconductive layer of an in an electrically insulating having resinous material dispersed photoconductor. For the production of such an electrophotographic recording material in the cone becomes the photoconductive coating smas se in the form of a layer on a layer support applied, which had previously been coated with a layer of an electrically conductive material, or directly on one electrically conductive support, e.g. on a support made of an electrically conductive metal. It was found that the electrophotographic properties, e.g., the sensitivity and / or spectral characteristics of the photoconductive layers of the resulting electrophotographic Recording materials can be improved in that the photoconductive coating compositions used or several photosensitizing substances or additives are incorporated. Typical suitable such additives are e.g. in U.S. Patents 3,250,615, 3H1 770 and 2,987 described. Photosensitizing additives of the specified type bring about a change in the sensitization in an advantageous manner or sensitivity of the photoconductive layer to which they are incorporated and / or a change in

009844/1623 -

BATH ORIGINAL

their spectral characteristics. For example, with the help of such Additions to the sensitivity of an electrophotographic recording material to radiation of a certain Wavelength increased or, if necessary, effected over a broad wavelength range. The one such Mechanism that brings about sensitization is not yet complete, despite the extremely great importance of this phenomenon enlightened. The special importance that experts attach to the specified sensitization results, for example, from that in all relevant specialist circles intensively looking for advantageous photosensitizing compounds for photoconductive ones Coating compounds of the specified type is researched.

The way in which a change in electrophotographic The desired properties usually depend on the intended use of the electrophotographic in question Recording material is intended. For example, in document copying technology, that in the electrophotographic Photoconductors present on the recording material have a spectral sensitivity which enables the reproduction of the entire allows a wide range of colors in question. Does the photoconductor used not correspond or not completely the specified conditions, its spectral properties are advantageously achieved by adding spectral sensitizing additives of the specified type changed " For other uses, it is often found that other electrophotographic properties are influenced advantageous to use in this way, for example, electrophotographic recording materials to achieve that are able to absorb a high surface potential and other advantageous Have properties, e.g. a low charge drop in the dark, a high one resulting from the sensitivity curve Sensitivity, a low residual potential after exposure and resistance to fatigue «,

0098A4 / 1623

Often the sensitization is determined for the production of electrophotographic recording materials photoconductive coating compositions with a content of photoconductors of a certain type by adding certain dyes from the large number of currently known dyes. However, it is disadvantageous that the addition of these known additives in the cone no photoconductive coating compositions are obtained in which all the properties specified, the lead to high-quality electrophotographic recording materials only in their interaction, noticeably improved are. There is therefore still a need for processes for the production of electrophotographic recording materials with improved properties, e.g. improved sensitivity in the shoulder and sag area of the Sensitivity curve, improved rendering properties for full areas, rapid regeneration and more advantageous electrophotographic Sensitivity to both positive and negative electrostatic charges.

There are already known methods with the help of electrophographic Recording materials with heterogeneous photoconductive layers containing dye aggregates, which the most of the noted disadvantages of known electrophotographic Recording materials do not have, can be produced. For example, there is a method in Belgian patent specification 705 117 for the production of an electrophotographic recording material in which a sensitizing dye and a polymeric binder dissolved in a customary known solvent, the coating composition obtained on a Electrically conductive layer support applied, the layer obtained dried and then with a solvent or solvent vapors to soften the layer and to aggregate the dye molecules present. A disadvantage of this known method, however, is that, after the coating compound has been applied, an additional Process stage, namely treatment with a solvent, is required.

009844/162 3

Furthermore, in the Belgian patent specification 705 118 a method for making an electrophotographic record smate rials of the specified type, with whose Help avoid the additional process step required following the coating of the lens wearer and the Aggregate formation of the dye molecules is brought about by the fact that the coating material consists of sensitizing dye and polymeric binder is subjected to strong shear forces generated at high speeds prior to application to the substrate will. The disadvantage of this known process, however, is that an additional process stage is also required to carry it out, 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 a higher sensitivity than those from the Belgian patents cited known processes can be produced. For example, in Belgian patent specification 729 078 a method is described according to which the photoconductive layer is produced by the known methods electrophotographic 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 requires an additional coating process.

Another disadvantage of the known processes mentioned is that the dyes used to produce the heterogeneous photoconductive coating compositions have different crystalline structures. Depending on the type of the present crystalline structure of the dye, the formation of dye aggregates when using the known processes specified can comparatively easily be ₀ or very difficult

009844/1623 bad original

The object of the invention is to provide a method with the aid of which simply by producing a photoconductive coating compound and applying the same to a support for highly sensitive electrophotographic recording materials with photoconductive layers that contain the sensitizing dye e contained in the form of aggregates, regardless of the type of crystalline structure used Dyes, using a single coating process without additional, the formation of the paraffin aggregates intended process stages can be produced.

The invention relates to a process for producing an electrophotographic recording material composed of an electrically conductive layer support and at least one heterogeneous photoconductive layer consisting of a continuous phase of a filmbildenderi polymer and a discontinuous phase comprising an electro-photographic sensitizing dye _s operating at a 2500 fold magnification of the layer forms at least for the most part recognizable aggregates, the photoconductive layer having an absorption maximum which is shifted from the absorption maximum of a homogeneous conductive layer formed from the same dye and the same binder, by applying a coating material of at least one sensitizing dye and an electrically insulating, film-forming material Binder for the sensitizing dye on an electrically conductive layer support and drying the film obtained ht, characterized in that a coating composition composed of dye, binder and solvent is used to produce the photoconductive layer, during the production of which the sensitizing dye or dyes are initially practically completely dissolved in the solvent before the binder is added.

BAD ORfGiNAL

009844/16 23

The heterogeneous coating compositions used in the process 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 been dissolved are the solutions obtained usually under Stirring mixed with polymeric binders and the binders dissolved. In this way, heterogeneous, multi-phase coatings are received processing masses, which consist of dye aggregates discontinuous phase is visible at 2500-fold magnification, although the coating compounds obtained are unarmed May appear practically optically clear to the eye. However, macroscopic heterogeneity may also be possible are present. The dye aggregates forming the discontinuous phase are expediently predominant Particle size from about 0.01 to 25 microns. To serve however, the heterogeneous coating compositions obtained for the sensitization of particulate matter additionally present Photoconductors, e.g. B. zinc oxide, its discontinuous phase optionally consists of particles with a particle size outside the specified range.

BATH ORIGINAL

0098AA / 1623

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

If the coating compound obtained when using the method of the invention is used in combination with an organic photoconductor, the photoconductive compound formed generally contains only two phases, since the photoconductor generally forms a solid solution with the continuous phase consisting of polymer. If, on the other hand, the multiphase coating material obtained when using the method of the invention is used in combination with a particulate photoconductor, then there may be three phases, namely a continuous phase consisting of polymer, a diacontinuous phase of the specified type containing the sensitizing dye and another discontinuous phase from the particulate photoconductor. Of course, the obtained when using the method of the invention, multiphase Beschiohtungsmasse can optionally also additional discontinuous phases, including ₀ given of entrapped contaminants and the like.,

009R44 / 162 3- "bath original

Another feature of the coating materials obtained when using the method of the invention is the fact that their absorption maximum lies in a spectral range which is longer or shorter wavelength than that in which the absorption maximum of a practically homogeneous mass of dyes and polymers of the same type, if these present in the form of a solid solution, lies. The extent to which the absorption maximum of such heterogeneous coating compositions is shifted into other wavelength ranges due to the formation of dye aggregates depends on the percentage up to which the dye present aggregates. In the multiphase heterogeneous coating compositions obtained when using the process of the invention, the absorption maximum is generally shifted by at least about 10 ι compared to homogeneous compositions of a comparable type. If mixtures of dyes are used, one dye can shift the position of the absorption maximum towards longer wavelengths and another dye can shift the position of the absorption maximum towards shorter wavelengths. -that a heterogeneous coating compound is present, possibly easier by making the discontinuous phase visible when enlarged accordingly.

Sensitizing dyes are used to carry out the method of the invention of various types can be used. Typical suitable sensitizing dyes are, for example, pyrylium dyes, for example pyrylium, thiapyrylium and belenapyrylium dye salts the general formula:

R ^C

BATH ORIGINAL.

9844/162 3

in which:

R ^a , R ^b , R ^c _s R ^d and R ^e on their own

R ^a and R ° or

Hydrogen atoms, alkyl radicals with e.g. 1 to 15 carbon atoms, for example Methyl, ethyl, propyl, isopropyl, butyl, tertiary butyl, amyl, isoamy ", Hexyl, octyl, nonyl or dodecyl radicals, Alkoxy radicals, e.g. methoxy, ethoxy, propoxy, butoxy, amyloxy, hexoxy or Octoxy radicals, or optionally substituted aryl radicals of the phenyl and naphthyl series, e.g. phenyl or 4-diphenyl radicals, or alkylphenyl radicals, e.g. 4-1thylphenyl or 4-propylphenyl radicals, or alkoxyphenyl radicals, e.g. 4-ethoxyphenyl, 4-methoxyphenyl-, 4-amyloxyphenyl-, 2-hexoxyphenyl-, 2-methoxyphenyl- or 3 »4-dimethoxyphenyl radicals, or β-hydroxyalkoxyphenyl radicals, e.g. 2-Hydroxyäthoxyphenyl- or 3-Hydroxyäthoxyphenylreste, or 4-Hydroxyphenylreste or halophenyl radicals, e.g. 2,4-dichlorophenyl, 3,4-dibromophenyl, 4-chlorophenyl or 3,4-dichlorophenyl radicals, or Azidophenyl, nitrophenyl or aminophenyl radicals, e.g. 4-methylaminophenyl or 4-dimethylaminophenyl radicals, or naphthyl radicals or vinyl-substituted ones Aryl radicals, e.g. styryl, methoxystyryl, Diethoxystyryl, dimethylaminostyryl, 1-butyl-4-p-dimethylaminophenyl-1,3-butadienyl- or ü-ethyl-4-dimethylaminostyryl radicals or

d β
R and R together to complete a to the

Pyrylium core fused on aryl ring

009844/1623

- ORIGINAL BATHROOM ■

required atoms,
X is a sulfur, oxygen or selenium atom, as well as

Z * ~ an anion, e.g. a ferchiorate, fluoroborate, iodide, Chloride, bromide, sulfate, periodate> or p-toluene sulfonate ion.

Typical suitable pyrylium dyes are listed in Table I below.

Table 1

link

No. Description

1 4 - ^ - bis (2-chloroethyl) aminophenyl7-2,6 - diphenyl-thiapyrylium-perchlorate

2 4- (4-Mmethylaminophenyl j- <i, 6-diphenylthiapyrylium perchlorate

2 4- (4-Dimethylaminophenyl) -2,6-diphenylthiapyrylium fluoroborate

4 4- (4-Bimethylamino-2-methylphenyl) -2,6-diphenylpyrylium perchlorate

5 4 - /? - bis (2-chloroethyl) aminophenyl7-2- (4-methoxyphenyl) -6-phenylthiapyrylium perchlorate

6 4- <4-I> imethylaminophenyl) -2, b-diphenylthiapyrylium sulfate

7 4- (4-Dimethylaminophenyl) -2,6-diphenylthiapyrylium p-toluene sulfonate

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BATH

8 4- (4-Mmethylaminophenyl) -2, ό-diphenylpyryiium ptoluenesulfonate

9 2- (2,4-Mmethoxyphenyl) -4- (4-dimethylaminophenyl) benzo (b) pyrylium perchlorate

I υ 2,6-bis (4-ethylphenyl) -4- (4-dimethylaminophenyl) -

thiapyrylium perchlorate

II 4- (4-Dimethylaminophenyl) -2- (4-methoxyphenyl) -6-phenylthiapyrylium perchlorate

12 4- (4-Dimethylaminophenyl) -2- (4-ethoxyphonyl) -bphenylthiapyrylium perchlorate

15 4- (4-Dimethylaminophenyl) -2 - (4-methoxyphenyl) -6- (4-methylphenyl) pyrylium perchlorate

14 4- (4-Diphenylaminophenyl) -2,6-diphenylthiapyrylium perchlorate

, 15 2,4,6-triphenylpyrylium perchlorate

16 4- (4-methoxyphenyl) -2,6-diphenylpyrylium perchlorate

17 4- (2,4-Bichlorophenyl) -2,6-diphenylpyrylium perchlorate

18 4- (3> 4-Di chlorophenyl) -2,6-diphenylpyrylium perchlorate

19 2 j 6-bis (4-methoxyphenyl) -4-phenylpyrylium perchlorate

20 6- (4-methoxyphenyl) -2,4 ~ diphenylpyryl j um-perchlo reit

21 2- (3> 4-dichlorophenyl) -4- (4-methoxyphenyl) -b-phenylpyrylium pprclilorate

BATH ORIGINAL

009B44 / 1B23

22 4- (4-amyloxyphenyl) -2,6-bis (4-ethylphenyl) pyrylium perchlorate

23.4- (4-Amyloxyphenyl) -2,6-bis (4-methoxyphenyl) pyrylium perchlorate

24 2,4,6-triphenylpyrylium fluoroborate

25 2,6-bis (4-ethylphenyl) -4- (4-methoxyphenyl) pyrylium perchlorate

26 2,6-bis (4-ethylphenyl) -4- (4-methoxyphenyl) pyrylium fluoroborate

27 6- (3> 4-diethoxystyryl) -2,4-diphenylpyrylium perchlorate

28 6- (3,4-Diethoxy-β-amylstyryl) -2,4-diphenylpyrylium fluoroborate

29 6- (4-Dimethylamino-β-ethylstyryl) -2,4-diphenylpyrylium fluoroborate

30 6- (1-n-Amyl-4-p-dimethylaminophenyl-1,3-butadienyl) -2,4-diphenylpyrylium fluoroborate

31 6- (4-Mmethylaminostyryl) -2,4-diphenylpyrylium fluoroborate

32 6- ^ öi-ethyl-ß, ß-bia (dimethylaminophenyl) vinylen7-2,4-diphenylpyrylium fluoroborate

33 6- (i-butyl-4-p-dimethylaminophenyl-1,3-butadienyl) 2,4-dlphenylpyrylium fluoroborate

34 6- (4-dimethylaminostyryl) -2,4-diphenylpyrylium perchlorate

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35 6- / B j ß-bis (4-dimethy! Aminophenyl) vinylen7-2,4-dipfaenylpyrylium perchlorate

36 2 _f 6-bis (4-dimethylaminostyryl) ~ 4-phenylpyrylium perehlorate

37 6- (B-methyl-4-dimethylaminostyryl) -2,4-diphenylpyrylium fluoroborate

38 6 ~ / T-ethyl-4 ~ (4 ~ dimethylaminophenyl) -1,3-feutadienyl7-2,4-diphenylpyrylium fluoroborate

39 6- ^ 5j β-bis (4-dimethylaminophenyl) vinylene 7-2,4-diphenylpyrylium fluoroborate

40 6- / T-methyl-4- (4 ™ dimethylaminophenyl) -1,3-butadienyl7-

2 j 4-dipheylpypylium fluoroborate

41 4 - * (4-Mmethylaminophenyl) -2,6-diphenylpyrylium peroxide

42 2 jβ-bis (4-ethylphenyl) -4-phenylpyrylium perchlorate

43 2 _f 6-bis (4-ethylphenyl) -4-methoxyphenylthiapyrylium fluoroborafe

44 2 j 4 j 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

009844/1623

48 4- (2,4-Mchlorophenyl) -2,6-diphenylthiapyrylium perchlorate

49 2,4,6-1'ri (4-methoxyphenyl) thiapyrylium-per chloro at

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

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

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

53 2,4,6-triphenyl thiapyrylitun-fluorobor at

54 2,4,6-triphenylthiapyrylium sulfate

55 4- (4-methoxyphenyl) -2,6-diphenylthiapyryIium fluoroborate

56 2,4,6-triphenylthiapyrylium chloride

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

58 4- (4-Amyloxyphenyl) -2,6-bis (4-methoxyphenyl) thiapyry lium-p er chlorine at

59 2, b-Bi s (4-ethylphenyl) -4- (4-methoxyphenyl) thi apyrylium perchlorate

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

b1 2 - ^ / 1, β-bis (4-dimethylamino phenyl) vinyl ene / -4 »6 diphenylthiapyrylium perchlorate

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62 6- (ß-Ethyl-4-dimethylaminostyryl) -2,4-diphenylthiopyrylium perchlorate

63 2- (3,4-diethoxystyryl) -4,6-diphenylthiapyrylium perchlorate

64 2,4 »6-trianisylthiapyrylium perchlorate

65 6 ~ ethyl-2,4 ~ diphenylpyrylium fluoroborate

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

67 6- / β, β-bis (4 ™ dimethylaminophenyl) vinylene-7-2,4-di (4-ethylphenyl) pyrylyln-perchlorate

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

69 6- (3,4-Diethoxy-β-ethylstyryl) -2,4-diphenylpyrylium fluoroborate

70 6- (4-methoxy-β-ethylstyryl) -2,4-diphenylpyrylium fluoroborate

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

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

73 2,6-I) iphenyl-4- (4-methoxyphenyl) thiapyrylium fluoroborate

74 2,6-bis (4-ethylphenyl) -4- (4-n-amyloxyphenyl) thiapyrylium perchlorate

009844/1623

75 2,6-bis (4-methoxyphenyl) -4- (4-n-amyloxyphenyl) thiapyrylium perchlorate

76 · 2,4, ö-'fris (4-methoxyphenyl) thiapyrylium-fluoro borate

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

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

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

80 4- (4-Dimethylaminophenyl) -2,6-diphenylselenapyrylium perchlorate

81 4- (4-Dimethylaminophenyl) -2- (4-ethoxyphenyl) -6-pheny1se1enapyry1ium perchlorate

82 4- ^ 4 "-BiS (2-chloroethyl) aminophenyl7-2,6-diphenylselenapyrylium perchlorate

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

04 4- (4-Dimethylamino-2-methylphenyl) -2,6-diphenylselenapyrylium perchlorate

85 5- (4-Dimethylaminophenyl) naphtho (2,1-b) selenapyrylium perchlorate

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

87 2,6-Di (4-diethylaminophenyl) -4-phenylselenapyrylium perchiorat and

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88 4 ™ (4-Bimethylaminophenyl) -2- (4 ™ ethoxyphenyl) -6-phenylthiapyrylium "fluoroborate

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

proven in which mean:

Hj and R ₀ gf, if necessary, substituted phenyl radicals which, if they are substituted, have at least one substituent consisting of an alkyl radical with 1 to 6 carbon atoms or an alkoxy radical with 1 to 6 carbon atoms,

R, © inen alkylamino-substituted, optionally also dialkylamino or haloalkylamino substituted Phenyl radical with an alkyl component containing 1 to 6 carbon atoms,

X is an oxygen or sulfur atom as well

Z "is an anion of the meaning given.

To carry out the process of the invention has, as already © rwäiniti, the use of Pyryliumfarbetoffon as proved to be particularly advantageous ^ but other photographic

44/1623

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graphisch Spektral Sensibilisiert.de Dyes that add to the light activate exposed areas of photographic layers in combination with an electrically insulating polymeric binder of the specified type can be used.

There are a variety of ways in which the method of the invention can be carried out conventionally known electrically insulating, film-forming polymeric binders can be used, e.g., polycarbonates and polythiocarbonates, polyvinyl ethers, polyesters, poly-CX-olefins, Phenolic resins and the like. Can also be used

^r i mixtures of 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 cause adhesion between the photoconductive layers and the support. Typical suitable polymeric binders are listed in Table II below.

Table II

link

Mr. Name of the polymer

1 polystyrene

2 polyvinyl toluene

3 polyvinyl anisole

4 polychlorostyrene

5 poly-ol methylstyrene

6 polyacenaphthalene

7 poly (vinyl isobutyl ether)

8 poly (vinyl cinnamate)

9 poly (vinyl benzoate)

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10 poly (vinyl naphthoate)

11 polyvinyl carbazole

12 poly (vinylene carbonate)

13 polyvinyl pyridine

14 poly (vinyl acetal)

15 polyvinyl butyral)

16 poly (ethyl methacrylate)

17 poly (butyl methaorylate)

18 poly (styrene-co-butadiene)

* 19 poly (styrene-co-methylinethacrylate)

20 polyistyrene-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 ^f ~ isopropylidenediphenyl-co-4,4'-isopropylidene-dicycloliexyl carbonate)

25 poly / ?, 4'-isopropylidene bis (2,6-dibromophenyl) carbonate 7

26 poly / ?, 4'-isopropylidene-bis (2,6-dichlorophenyl) -

carbonate7

27 Poly / ?, 4 ¹ -Isopropylidenebis (2,6-dimethylphenylίο carbonate 7

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

29 poly (4,4'-isopropylidenediphenyl terephthalate-co-isophthalate)

30 poly (3,3'-ethylenedioxyphenylthiocarbonate)

009844Π623

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

32 poly (4,4'-isopropylidenediphenyl carbonate)

33 poly (4,4'-isopropylidenediphenylthio carbonate)

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'-Isopropylidene bis (2-methylphenyl) carbonate 7

38 poly (4 »4'-isopropylidenediphenyl-co-1,4-phenylene carbonate)

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

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

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

42 poly (4,4'-isopropylidenediphenyl-co-4,4'-carbonyl diphenyl carbonate)

43 poly (4,4'-isopropylidenediphenyl-oo ^ »4'-lthylenediphenyl carbonate)

44 Poly / ?, 4'-methylene-bis (2-methylphenyl) carbonate 7

45 Poly / T, 1- (p-bromophenylethane) bis (4-phenyl) carbonate 7

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46 Poly / s4 '~ Isopropylidenediphenyl-Go-sulfonyl-bis (4-phenyl) c arbonatj

47 Poly / T, 1-cyclohexanebis (4-phenyl) carbonate 7

48 poly (4j4 ^l -isopropylidenediphenoxydimethylsilane)

49 poly / Ϊ, 4'-isopropylidene bis (2-chlorophenyl) carbonate /

50 Poly / "bc, (X, cX ', oi ' -5? Etramethyl-p-xylylol-bis (4-phenyl carbonate p ⁷

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

52 poly (dichlorotetrafluoroisopropylidene-di-4-phenyl carbonate)

53 poly ( $ 4'-isopropylidenediphenyl-4,4'-iaopropylidenedibenzoate)

54 Poly (4 _s 4'-Isopropylidendibenzyl-4, 4'-isopropylidendibenzoat)

55 poly (4 »4'-isopropylidene-di-1-naphthyl carbonate)

56 Poly / 1,4'-Isopropylidene-bis (phenoxy-4-phenylaulfonate 27

57 acetophenone formaldehyde resin

58 poly / ?, 4'-isopropylidene-bis (phenoxyethyl) -co-ethylene terephthalate 7

59 phenol-formaldehyde resin

60 polyvinylaoetophenone

61 Chlorinated polypropylene

62 chlorinated polyethylene

63 poly (2,6-dimethylphenylene oxide)

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64 poly (neopentyl-2,6-naphthalenedicarboxylate)

65 poly (ethylene terephthalate-co-isophthalate)

66 poly (1,4-phenylene-co-1, 3-phenylene succinate)

67 poly (4,4'-isopropylidenediphenyl-phenylphosphonate)

68 poly (m-phenyl carboxylate)

69 poly (I ^ -Oyclohexanedimethylterephthalat-co-Isophthalat)

70 poly (tetramethylene suecinate)

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-g-naphthylthiocarbonate)

75 polyCDiphenylmethane bis ^ -phenyl carbonate)

76 poly / 2,2- (3 ~ methylbutane) bis-4-phenyl carbonate 7

77 Poly / 2,2- (3,3-dimethylbutane) to s-4-phenyl carbonate 7

78 Poly 1 1,1 - / T- (1-NaphthyllJbis ^ -phenylcarbona-Ä

79 poly / 2,2- (4-methylpentane) bis-4-phenyl carbonate 7

80 poly / ?, 4 '- (2-norbornylidene) diphenyl carbonate 7

81 poly / ?, 4 '- (hexahydro-4f7-methanoindan-5-ylidene) diphenyl carbonate 7 and

82 poly (4,4'-isopropylidenediphenyl carbonate block oxyte e trame ethylene)

Compounds Nos. 28, 30-47, 49, 51, 53, 54 and 76-82 of the Table II shown have been found to be particularly advantageous in carrying out the process of the invention.

Polymeric binders used with preference are, for example, also linear polymers or copolymers with recurring Structural units of the general formula:

00984AM623

R,

-C-

in which:

for themselves 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, e.g. from halogen atoms or alkyl radicals with 1 to Consist of 5 carbon atoms,

or together the atoms required to complete a cyclic hydrocarbon radical, for example a cycloalkane radical, for example a cyclohexyl radical, or a polycycloalkane radical, for example an ITorbornyl radical, the radicals
have material atoms,

, and R, - together up to 19 hydrocarbons or halogen atoms, for example chlorine, bromine or iodine atoms, or alkyl radicals with 1 to 5 Carbon atoms as well

a divalent remainder of the formulas

0 S. 0 0 t » ti It Il 0-U-O-, -0-C-O-, -C-O-, -C- -O-CH _? -,

009844/1623

O CH,

Il I J

-G-O-GH-,

Il

-CH ₂ -OOO-, or -

If the linear polymers are hydrophobic Polycarbonates, the use of polymers with recurring structural units of the following formula:

■ C

R-

■ 0 ·

Il

O-

in the R. and

have the meaning given and the radicals

R phenylene radicals substituted with halogen atoms or alkyl radicals can be, mean.

Compounds of the specified type are described, for example, in U.S. patents 3,028,365 and 3,317,466. As special It has proven advantageous to use polycarbonates which have a Alkylidene diarylene component, e.g., using Polycarbonates produced by bisphenol A, e.g. those produced by Eeterauschechr between diphenylocarbonate and 2,2-bis-4-hydroxyphenylpropane be won. Compounds of the specified type are described, for example, in U.S. Patents No. 2,9y9,750; 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.

00984AM623

To carry out the process of the invention, the use of film-forming poly carbonate resins of the most varied types has proven to be expedient, particularly advantageous results being achievable with those commercially available polycarbonates whose inherent viscosity is about 0.5 to 0.6. Furthermore, the use of high molecular weight polymers, for example high molecular weight bisphenol A polycarbonates, has also proven advantageous. Preferably, in such high molecular weight polymers are those having an inherent viscosity of more than 1, measured in 1,2-dichloroethane at ψ a concentration of 0.25 g / 100 ml and a temperature of about 25 ° O. For example, the use of high molecular weight polycarbonates has the advantageous effect that in coating compositions with a comparatively high content of sensitizer dye, the formation of the dye aggregates is facilitated and a photoconductive composition with increased sensitivity is obtained.

The coating compositions obtained using the process of the invention are advantageously suitable for increasing the sensitivity and expanding the spectral ± sensitivity range of the most varied of organic and. inorganic photoconductors, which can belong to both the η-type and the p-type. A typical suitable inorganic photoconductor is, for example, zinc oxide. Numerous organic photoconductors, including organometallic photoconductors, which have little or practically no photoconductivity persistence, are also suitable. Typical suitable such organometallic compounds include organic derivatives of metals of the groups Ilia, IVa and Va of the Periodic Table, for example, _0, which have a bound to the metal atom such Aminoarylrest least. Typical suitable organometallic compounds of this type are, for example, triphenyl-p-dialkylaminophenyl derivatives of silicon, germanium, tin and lead, and tri-p-dialkylaminophenyl derivatives of arsenic, antimony, phosphorus _?

BAD 009844/1623

Bismuth, boron, aluminum, gallium, thallium and indium. Suitable Photoconductors of the specified type are e.g.

German patent specification (patent application

P 17 72 775.2) and (patent application P 19 43 387.5)

described.

The use of organic photoconductors of the so-called "organic amine type" which have at least one "mino group" as a common structural feature has proven to be particularly expedient. Typical suitable organic xiOtoconductors of the specified type which can be spectrally sensitized when using the method of the invention are, for example, arylamine compounds, for example ( 1) Diarylamines, such as diphenylamine, dinaphthylamine, N, N ^f -diphenylbenzidine, N-phenyl-1-naphthylamine, N-phenyl-2-naphthylamine, N, N'-diphenyl-p-phenylenediamine, 2-carboxy-5- chloro-4'-methoxydiphenylamine, p-anilinophenol, N, N'-di-2-naphthyl-p-phenylenediamine, the compounds described in US Pat. No. 3,240,597 and the like, and (2) triarylamines, for example (a ) non-polymeric triarylamines, such as triphenylamine, Ν, Ν, Ν ¹ , N'-tetraphenyl-m-phenylend: L ^ amine, '4-acetyltriphenylamine, 4-hexanoyltriphenylamine, 4-lauroyltriphenylamine, 4-hexyltriphenylamine, 4-dodecyl , 4,4'-bis (diphenylamino) benzil, 4,4 ' -Bis (diphenylamino) benzophenone and the like, and (b) polymeric triarylamines, such as poly / N, 4 "- (N, Ii ', N'-triphenylbenidine) /» polyadipyltriphenylamine, polysebacyltriphenylamine, polydecamethylene triphenylamine, poly-N- ( 4-vinylphenyl) diphenylamine, poly-N- (vinylphenyl) -OC, CX'-dinaphthylamine and the like. Further suitable photoconductors of the organic amine type are described, for example, in US Pat. No. 3,180,730.

As suitable photoconductors that can be sensitized according to the invention the compounds of the following general formula known from US Pat. No. 3,265,496 have also proven themselves:

R - / ~ N - T -_7 _b Q M

00984A / 1623 BAD ORiGINAL

proven in the significant

T a mononuclear or polynuclear, either condensed or linear divalent aromatic radical, e.g. a phenyl, naphthyl, biphenyl or binaphthyl radical, or a substituted divalent aromatic radical of the specified type, the substituent of which, for example, consists of a Acyl radical with 1 to about 6 carbon atoms, for example an acetyl, propionyl or butyryl radical, an alkyl radical with 1 to about 6 carbon atoms, for example a methyl, ethyl, propyl or butyl radical, an alkoxy radical with 1 to about 6 carbon atoms, for example a "methoxy, ethoxy", propoxy or pentoxy radical, or from a There is a nitro group,

M a mononuclear or polynuclear, either condensed or linear monovalent aromatic radical, e.g. a phenyl, naphthyl or biphenyl radical, or a substituted one monovalent aromatic radical of the specified type, the substituent of which, for example, consists of an acyl radical with 1 to about 6 carbon atoms, for example an acetyl, propionyl or butyryl radical, from an alkyl radical with 1 to about 6 carbon atoms, for example a methyl, ethyl, propyl or butyl radical, an alkoxy radical with I to consists of about 6 carbon atoms, for example a methoxy, propoxy or pentoxy radical, or a nitro group,

Q is a hydrogen or halogen atom or an aromatic amino radical, e.g. one of the general formula MNH-,

b = an integer from 1 to 12 and

R is a hydrogen atom or a mononuclear or polynuclear, either fused-on or linear aromatic radicals, for example a phenyl, naphthyl or Biphenyl radical, a substituted aromatic radical of the

009844M623

specified type, whose substituent consists of an A3yl, Alkoxy, acyl or nitrogen radical, or from a poly (4'-vinylpheny radical, which is bonded to the nitrogen atom via a carbon atom of the phenyl radical.

The use of polyarylalkanes has proven to be particularly advantageous existing photoconductors, e.g. From US Pat. No. 3,274,000 and French Pat 1,383,461 are known.

Such photoconductors can, for. B. from leuco bases of diaryl or triarylmethane dye salts or 1,1,1-triarylalkanes, the alkane radical of which has at least two carbon atoms, and Tetraarylmethanes in which at least one of the aryl radicals bound to the alkane radical or methane radical is through an amino group is substituted exist. The last two photoconductor classes mentioned are not leuco bases.

The use of polyarylalkanes has proven to be particularly advantageous existing photoconductors have been shown to have the following general formula:

C E

in which:

D, E and G aryls of the phenyl and naphthyl series, with at least one of the radicals D, E and G is substituted by an amino group, and

J is a hydrogen atom, an alkyl radical or an aryl radical from the phenyl and naphthyl series.

009844/1623

In the case of the aryl radicals bound to the central carbon atom

UlQ

it is -preferably / phenyl radicals, but it can be also be laphthyl residues. The aryl radicals can also be in Ortho, meta or para position, e.g. by Alkyl or alkoxy radicals with generally 1 to 8 carbon atoms, hydroxy radicals or halogen atoms. As particularly advantageous substituted aryl radicals are in the ortho position proven substituted phenyl radicals. The aryl radicals that are present can also be linked to one another or cyelized, e.g. with the formation of a fluorene ring.

The amino sub-

m
L.

substituents can be given by the formula

be reproduced, where L alone is an alkyl radical with usually 1 to 8 carbon atoms, a hydrogen atom or a ^ «xylrest, or both L groups together to complete a heterocyclic amine radical with in the Eeg ^ X " Ms β Hingatomen, eg of a morpholine, pyridyl or pyrryl radical required atoms mean.

Polyarylalkanes of those specified have been found to be particularly advantageous Proven formula in which at least one of the radicals * D, E or S is a p-dialkylaminophenyl radical. Is in of the formula J given for an alkyl radical, this can, for example, advantageously be an alkyl radical having 1 to 7 carbon atoms be.

Typical suitable polyarylalkane photoconductors are e.g. of the following compounds listed in Table III

0098Λ4 / 1623

Table III compound designation

1 4,4'-benzylidene-bis (IT, N-diethyl-m-toluidine)

2 4 ', 4 "-I> iamino-4-dimethylamino-2 ·, 2" -dimethyltriphenylmethane

3 4 ', 4 "-bis (diethylamino) -2,6-dichloro-2 ^f , 2» - · dimethyltriphenylmethane

4 4 ·, 4 ^M -bis (diethylamino) -2 ^f , 2 »-dimethyldiphenylnaphthylmethane

5 2 ¹ , 2 ^M -dimethyl-4,4 ', 4 "-tris (dimethylamino) triphenylmethane

6 4 ', 4 "-bis (diethylamino) -4-dimethylamino-2 ·, 2» - dimethyltriphenylmethane

7 4 ", 4" -bis (diethylamino) -2-chloro-2 ", 2" -dimethyl-4-dimethylaminotriphenylmethane

8 4,4 "-bis (diethylamino) -4-dimethylamino-2,2 ', 2" -trimethyltriphenylmethane

9 4 ", 4" -bis (dimethylamino) -2-chloro-2 ', 2 "-dimethyltriphenylmethane

10 4 ^l, 4 ^n-bis (dimethylamino) -2 ^t, 2 "-dimethyl-4-methoxytriphenylmethan

11 bis (4-diethylamino) -1,1,1-triphenylethane

12 bis (4-diethylamino) tetraphenylmethane

13 4 ', 4 "- ^b is (benzyläthylamino) -2 ^l, 2' -dimethyltriphenylmethane

0098ΑΛ / 1623

14 4 *, 4 "-bis (diethylamino) -2 ', 2» -diethoxytriphenylmethane

15 4,4'-bis (dimethylamine) -1,1,1-triphenylethane

16 1- (4-N, lf-Dimethylainino phenyl) -1,1-diphenylethane

17 4-dimethylaminotetraphenylmethane and

18 4 ~ Diethylaminotetraphenylmethane

Photoconductors which can be used using the method of the invention are also the 4-diarylamino-substituted ones Ohalkone. Typical suitable compounds of this type are low molecular weight non-polymeric ketones of the following formula:

N-

- CH = CH - C - R

in which R ₁ and H _{2 are} optionally substituted phenyl radicals and where K _{2 is} advantageously a phenyl radical of the formula:

represents, in which R, and ti, mean aryl radicals, aliphatic radicals with 1 to 12 carbon atoms, for example alkyl radicals with preferably 1 to 4 carbon atoms, or hydrogen atoms.

0098-U / 1623

It has proven particularly advantageous to use compounds of the general formula given in which the radicals R ₁ denote optionally substituted phenyl radicals and Rp denotes a diphenylaminephenyl, dimethylaminophenyl or phenyl radical.

Other suitable photoconductors that are used when carrying out the method of the invention can be incorporated into the coating compositions containing dye aggregates, e.g. Rhodamine B, malachite green, crystal violet, phenosafranine, Cadmium sulfide, cadmium selenide, parachloronil, benzil, trinitro fluoro enone, and tetranitrofluorenone.

Typical suitable photoconductor and photoconductive compositions whose itopfindlichkeits-, öensibilisierungs- and / or regeneration properties using the present invention resulting heterogeneous compositions are improvable for example, are listed in the following table IV USA Patents öeschrieben _e

Table IV United States Patent Bores

3 Ιυ7 Ö61 3 158 475 3 041 165 3 161 505

3 066 023 3 163 530 3 072 479 3 163 531

3 047 095 3 163 532 3 112 197 3 169 060

3 133 022 3 174 854 3 144 633 3 180 729

3 122 435 3 180 730 3 127 266 3 189 447

3 130 046 3 206 306 3 131 060 3 240 597

^ 139 338 3 257 202 3 139 i39. 3,257,203

3 HO 946 3 257 204 3 141 770 3 265 496

3,148,982 3,265,497 3,155,503 3,274,000

Are the incurred when using the method of the invention Coating materials added photoconductor, bo has the use of organic, e.g. organometallic photoconductors in concentrations of at least about

_BATH 009844/1623

Oj 5 GeWffl ^, based on the total amount of solids added to the coating solvent, proven to be appropriate, the upper limit of the concentration range of PJaotoconductor can be very different and can be up to 99%, based on the total amount of solids. When using a photoconductor, it has proved to be ^ - Sonders proved advantageous, this applied in concentrations of about 10 to 80 wt $> be understood, however, as already mentioned, containing products resulting from use of the method of the invention dye aggregates heterogeneous coating compositions may also. can be used to produce photoconductive layers without the addition of a ψ photoconductor.

A wide variety of organic coating solvents can be used to carry out the process of the invention, e.g. liquid hydrocarbons which can be substituted, halogenated hydrocarbon solvents in a particularly advantageous manner. Coating materials which have proven to be suitable are those which are capable of dissolving the sensitizing dye used and of dissolving or at least swelling the polymeric binder used to a high degree. Furthermore, it has been found to be useful when the solvents used are volatile, preferably when they have a boiling point below about 200 ⁰ G, "to be particularly advantageous the use has proved of solvents selected from halogenated short chain alkanes having 1 to 5 carbon atoms consist, for example, the use of dichloromethane, Mchloräthan, dichloropropane, tri chlorine than, trichloroethane, Tribromomethan, trichloromonofluoromethane, Trichlorotrifluoroäthan and the like _0, further halogenated benzene compounds, for example Ghlorobenzol, bromobenzene, dichlorobenzene and the like. Lösungsmittelgemisohe are also useful.

BAD ORSGINAL

009844/1623

To carry out the method of the invention, the concentration of sensitizing dye, which is initially practically completely dissolved in an organic coating solvent, can be very different, depending on the solubility of the dye used in the solvent used and on 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. Es.hat proved zweckmäs ^r 'ig to use the sensitizing dyes in concentrations of about 0.5 to 30 Gew.ifo, based on the G-esamtmenge added to the coating composition solids.

To carry out 'the method of the invention a sensitizing dye is at least mixed with the coating solvent and the resulting mixture at about room temperature, for example at 20 ⁰ C as long as is stirred until the dye dissolved completely. In the Hegel it proves to be sufficient to agitate the G-emic of dye and solvent up to about 2 to j hours to a virtually complete solution to obtain the dye. For convenience, the dye is usually dissolved in the cone at about room temperature, but elevated temperatures can also 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 is carried out 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. After that, a

"BAD ORIGINAL 0098ΛΑ / 1623

Piiotoconductor added and containing the specified components Solution stirred briefly. The coating compound obtained in this way does not require any further additional treatment can be used for coating substrates and is applied to a applied to a suitable substrate. The layer obtained is then dried in a conventional manner. The drying can be done, for example, in such a way that the solvent is simply allowed to evaporate at room temperature and normal pressure will. Furthermore, the layer obtained can be dried with the aid of circulating air or by moderate heating Care should be taken to avoid damage caused by heat. That way through simple Coating and drying obtained containing dye aggregates Photoconductive layer does not require any further treatment.

Those applied to substrates by the method of the invention photoconductive layers can have a wide variety of thicknesses. Usually they have photo-conductive Layers proved to be expedient which, before drying, have a thickness of about 10 to 1250 / u, preferably of about up to 750 / u. However, useful results can also be achieved outside the specified range.

There are a variety of ways in which the method of the invention can be carried out customary known electrically conductive layer supports can be used, e.g. layer supports made of paper with a relative humidity of over 20 #, from aluminum foils and paper made of laminates, made of metal foils, for example aluminum foils and zinc foils, from metal plates, for example aluminum, copper, zinc, brass and galvanized plates, made of a metal layer vapor-deposited on paper s made of e.g. silver, nickel, aluminum and the like, or from conventionally known photographic supports based on cellulose acetate, polystyrene, polyethylene terephthalate) and the same. Furthermore, electrically conductive

8 ^ / 1623 ^BATH

Capable substances, such as nickel, are vapor-deposited in a vacuum onto transparent substrates in the form of thin layers, that electrophotographic recording materials can be produced which optionally exposes from each of the two sides can be. A particularly advantageous electrically conductive layer carrier can be produced in such a way that a substrate made of e.g. polyethylene terephthalate is provided with a photoconductive layer comprising a semiconductor dispersed in a resin, e.g. copper (I) iodide, contains. Conductive layers of the specified type, possibly in combination with insulating barrier layers, are e.g. in the USA patents> 245 833 and 3,428,451. Suitable, electrically conductive layers are, for example, also made from the liatric salt of a carboxy ester lactone of maleic anhydride and a vinyl acetate polymer. Conductive layers of the specified type as well advantageous processes for their preparation are described in U.S. Patents 3,007,901 and 3,267,807, for example.

The method of the invention in which first the sensitizing dye is practically completely dissolved in a coating solvent before the binder as well as optionally a photoconductor are added, has, in addition to the numerous advantages already listed the surprising advantage that it can be used to produce electrophotographic recording materials with photoconductive layers in just one coating process, which is a higher concentration of dye! on than comparable, have layers which can be produced by conventional methods. The photoconductive obtained in the invention The higher dye concentration present in the layers advantageously to a higher electrophotographic sensitivity. It can be seen, for example, that after the Process of the invention producible electrophotographic recording materials with only one dye-containing photoconductive Layer are practically just as sensitive,

0098ΑΛ / 1623 ^BAD

such as known electrophotographic recording materials with several dye-containing rails, for their production E.g. after the given known Terfahren + on a first dye-containing photoconductive layer a further dye layer is applied. It is also an advantage j that according to the method of the invention, highly sensitive electrophotographic recording materials can be produced without the need for a second coating operation j as well as the quality and sensitivity of the The recording materials to be produced can be controlled in a particularly advantageous manner, according to the method of the inventor Electrophotographic recording materials which can be produced are also distinguished by an improved electri behavior from, as can be seen from regeneration tests, in which the specimens are charged and exposed repeatedly. Further advantages to be achieved according to the invention le ρ e.g. the possibility of highly sensitive electrophotographic Recording material independent of the crystalline one Structure for the production of the coating compounds uses © '«. Sensitizing dyes in a simple manner herst '.üsllan, have already been mentioned.

The electrophotographic recording materials which can be produced by the process of the invention are suitable for carrying out electrophotographic processes which require _{the customary known 9 electrically conductive layers.} For example, they can be used to carry out the so-called xerographic process, in which an electrophotographic recording material is stored in the dark and provided with an electrostatic surface charge by exposing it to an oorona discharge. The uniform surface charge thus imparted to the photoconductive layer remains in the dark because of the practically insulating properties of this layer, that is to say because of the low conductivity of this layer in the dark. The electrical formed on the surface of the photoconductive layer

See Belgian patent specification 729 078

0098Λ4 / 1623 BAD ORIGINAL

A trostatic charge is then created by image-wise exposure by customary, known exposure methods, for example using a contact printing technique or by lens projection of an image selectively from the surface of the layer dissipated, so that a latent electrostatic image is generated in the photoconductive layer. By following a If the film surface is exposed using the specified methods, an electrostatic charge pattern forms because which leads to the light energy hitting the photoconductor, : The electrostatic charge in the areas hit by the light is proportional to the intensity of the areas that hit it Radiation is dissipated from the pilm surface.

The charge pattern formed during exposure is then developed or transferred to the surface of a receiving material and developed there. Development is accomplished by visualizing either the charged or uncharged areas of the latent image by treatment with an electrostatically attractable, optically dense particle-containing agent. The electrostatically attractable development particles can be in the form of a dust, for example powder, or in the form of a pigment, ie toner, incorporated into a resinous carrier. Such a toner is applied to the latent electrostatic image to be developed, preferably with the aid of a magnetic brush, in order to ensure the development of full areas. Processes for the production and use of devices based on magnetic brushes for applying toners are described, for example, in US Patents 2,786,439; 2,786,440; 2,786,441; 2,811 46 ^; 2,874,063; 2,984 1b3; 3,040,704; 3,117,884 and Reissue Patent 2b 779.

Optionally, the electrostatic latent image can also be included Can be developed with the help of liquid developers. In the so-called liquid development, the developer particles are onto the image-bearing surface of the exposed electrophoto-

0098AW1623

BAD ORSGlMAL

graphic recording material in the form of developers, in which the developer particles are incorporated into a carrier material consisting of an electrically insulating liquid are upset. Development processes of the specified type are known and are described in numerous references, e.g. in the USA patent 2 yO? 674 and Australian patent 212 315.

When dry development processes are used, a visible, permanent image is usually produced with the aid of a developer containing electrostatically attractable particles, one component of which consists of a low-melting resin. If the image provided with such a developing powder is heated, the resin melts or softens, possibly with penetration into the film surface, so that in this way permanent adhesion of the developer powder to the surface of the photoconductive layer is effected. If necessary, the electrostatic charge image formed on the photoconductive layer is transferred to a second carrier material, for example one based on paper, whereupon the finished copy is produced in this image-receiving material by developing while melting the developer. Processes of the specified type are known and are described in numerous references, for example in US Patents 2,297,691 and 2,551,582 and in ¹¹ RCA Review "Volume 15 (1954), pages 469 to 484.

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

Example 1 (comparative example)

To prepare a serving as the comparative sample elektrophotographisehen Aufzeichnungsmnterials 85 parts by weight of dichloromethane and 9 parts by weight of known under the name "Lexan 105" bisphenol A polycarbonate resin was stirred in a mechanical mixer for 2 hours at about 2O ⁰ C rapidly, bi, - the resin is completely dissolved was. The preserved lo-

BAD ORSGINAi 0098 ^ / 1623

6 parts by weight of the photoconductor 4,4'-diethylamino-2,2'-dimethyltriphenylmethane were added to sling, whereupon the stirring ^{was continued at about 2O 0} U for 30 minutes. Thereafter, 0.3 parts by weight of 4- (4- Dimethylaminophenyl) -2,6-diphenylthiapyrylium fluoroborate was added and the resulting solution was stirred for 2 hours. The resulting coating mass was then filtered through a 2 to 5 / i fiber filter cartridge known ^{as the 11 FuIfIo cartridge ".}

The filtered solution was applied to a substrate made of a polyethylene terephthalate) oil, which was provided with a vapor-deposited thin electrically conductive nickel layer, in such a way that the thickness of the layer obtained, measured after drying, was about 10 to 12 microns. The optical density of the resulting electrophotographic recording material was then measured at 600 and 690 μm. The recording material was then electrostatically charged under an oorona discharge until the surface potential measured with the aid of an electrometer sample was about 600 volts. The charged recording material was then exposed to a 3000 ° K tungsten light source through a gray wedge with graduated density and an interference filter with 30% transmittance at 600 μm and short wavelength radiation. Such an exposure reduces the surface potential of the recording material below each level of the gray wedge from its original potential V to a lower potential V , the exact value of which depends on the amount of exposure actually encountered in the area in question, measured in meter-candle-seconds " The potentials of the exposed recording material were measured and the results obtained were evaluated graphically by plotting the surface potential V versus log exposure for each exposure step. The actual positive or negative sensitivity of the tested electrical

0098AW1623. _ba d

photographic material can then be expressed are called the reciprocal of the exposure required is to reduce the surface potential to an arbitrarily set value. In the present Ji'alle unless otherwise indicated, the positive or negative sensitivity determined in the manner indicated expressed as "the value 10 divided by the exposure in meter-candlestick-seconds, which are used to reduce the applied overflow potential of 600 V to 50 V is required, The sensitivities determined in this way are referred to as positive or negative 50 V sag sensitivities « The "in the testing of the in the specified manner produced * serving as a comparison sample electrophotographic Results obtained on drawing material, viz its optical density and electrophotographic sensitivity, are listed in Table V below.

Example 2 (comparative example)

After dma in Example 1 indicated a method Besohichtungsiiasse was prepared with the exception that placed in front of the filter 10 $> of the solution obtained in a high speed running Sclier mixer for 20 minutes and were subjected to a shear stress. The portion of the solution subjected to the shear action was then combined again with the remaining 90 % of the untreated solution. The resulting electrophotographic recording material was tested for optical density and electrophotographic sensitivity according to the method described in Example 1. The results obtained are shown in Table V below. The results show that the shear treatment increases both the optical density and the electrophotographic sensitivity.

BATH ORIGINAL

00984Λ / 1623

Example j

Using the components specified in Example 1, a coating compound was prepared according to the method of the invention in the way that the sensitizing dye was first added to the coating solvent and the resulting mixture was stirred for about 2 hours until the dye was dissolved. The polymeric binder was then added to the resulting solution, followed by stirring for a further 2 hours. The photoconductor was added acluably to the solution obtained, whereupon the mixture was again rapidly stirred for 1/2 hour. However, i ± e solution was not subjected to a shear treatment.

The coating composition obtained was then according to the in Example I described method applied to a support of the specified type, whereupon the resulting electrophotographic Recording material as in Example 1 has been tested for optical density and sensitivity. The results are shown below Taoelle V listed. The results show that both the optical density as well as the electrical sensitivity are improved over an electrophotographic one Recording material made by customary known methods while observing the customary order of addition of the individual components has been manufactured.

The obtained electrophotographic recording material. could advantageously be charged, exposed and made using liquid developers in the U.S. Patent 2,907,674 for producing high quality visual images will.

00984W162-3

bath

Example 4 (comparative example)

The procedure described in Example 3 was repeated with the exception that first the polymeric binder was added to the Coating solvent was added and the resulting mixture was stirred for 2 hours, after which the sensitizing dye was added and stirred again for 2 hours. The resulting solution was then mixed with the photoconductor, and the resulting mixture was again stirred for 30 minutes. In this way a coating was created obtained, which was applied to a substrate of the specified type by the method described in Example 1, whereupon the obtained electrophotographic recording material was tested for electrical sensitivity and optical density in the manner indicated.

Several electrophotographic Recording materials produced, the sensitivity of which was measured in each case. The results obtained differed greatly from each other, revealing that some of the electrophotographic recording materials obtained a very much lower sensitivity than other recording materials produced by the same process had. It follows from this that it is not sufficient to use a solution of sensitizing dye in the usual known manner and to prepare polymeric binder before the photoconductor is dissolved in the resulting solution, but that only according to the method of the invention in compliance with the precisely defined .Reihenordnung of the pulls of the individual Components coating compositions can be produced which lead to electrophotographic recording materials with improved Sensitivity and optical density lead.

Example ί> (comparative example)

Following the procedure described in Example 1, using twice the amount of sensitizing dye, a Coating mass produced and processed further to form an electrophotographic recording material. the

009844/1623 BAD ORIGINAL '

Results of the electrophotographic i'ests' are in the below specified 'fabeile V listed. Me results show that the optical density and electrical sensitivity to the electrophotographic recording material produced according to Example 1 are only slightly increased, As a result, when using the specified method, hardly more dye is dissolved than when using it the procedure described in Example 1.

Example 6 (comparative example)

The procedure described in Example 2 was repeated using a coating solution prepared according to Example 5. The electrophotographic recording material obtained using a coating material of which 10 ^σ / ο had been subjected to a shear stress was tested for optical density and electrical sensitivity according to the method described in Example 1. The results obtained are given in Taoelle V below. The results show that the optical density and electrophotographic sensitivity are only slightly higher than in the electrophotographic recording material produced according to Example Z using only half the amount of sensitizing dye. It can also be seen that the electrophotographic recording material produced using the coating material subjected to a shear pretreatment has an optical density and electrical sensitivity which are not greater than those of the electrophotographic recording material produced by the method of the invention according to Example t> using only half the amount of sensitizing dye .

Example 7

Following the procedure described in Example 3, under Use double the amount of sensitizing dye a caulking compound is made and placed on a substrate applied, whereupon the obtained electrophotographic

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see recording material on optical density and electrical Sensitivity has been tested. The results obtained are listed in the following table ¥. The results show that according to the method of the invention when using almost twice as high an electrophotographic sensitivity as compared to twice the amount of sensitizing dye will.

In the investigation of the enjoyable examples 1 to 3 and 5 to electrophotographic recording materials obtained Results are shown in Table V below:

Table V example

No.

2
3
5
6th

Optical density 600 my 690 rough

0.50 1.24 1.55 0.52 1.57

Photo sensitivity when exposed through an interference filter to a lower potential of -50 V

<50 800 900

<50 900

• I6OO

Example 8

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

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Example 9 (comparative example)

The procedure described in Example 4 was repeated using twice the amount of sensitizing dye. The obtained electrophotographic recording material was tested for sensitivity and optical density. No clear results were obtained, so not It was possible to establish with certainty whether at least a slight increase in doubling the dye concentration the sensitivity and optical density is educational.

Example 10

The procedure described in Example> was repeated with the exception that 4-diethylaminotetraphenylmethane was used as the photoconductor and 4- (4-dimethylaminophenyl) -2,6-diphenylthiapyrylium perch-lorate as the sensitizing dye. Based on .Feststoffe, the solution $ dye and about 37 percent of the type described in Example 1, 2 wt..> Photoconductors as well as in a 100 wt. ^Σ / ο missing amount of binder added. First the dye and then the binder and the photoconductor were dissolved, whereupon the resulting coating solution was applied to a substrate of the specified type using the method described in Example 1 at a coating block temperature of about 15 ° C. The obtained electrophotographic recording material was tested for electrical sensitivity. The 100V negative sag sensitivity was found to be about 1,100.

Thereafter, the recording material was recorded using 100 cycles tested for regeneration properties. To carry out this test, the film sample was tested according to the in Example 1 described method subjected to a Uorona discharge and then exposed, whereupon they one Has been exposed to flooding or extinction exposure, where the entire cycle performed within 3 seconds

00984A / 1623 BAD ORIGINAL

became. The specified treatment cycle was repeated 1OU times, whereupon the results obtained when measuring the surface charge of the recording material under investigation after the first and the 100th cycle were compared. It was found that the maximum surface charge the photoconductive layer after the 10u. Cycle in Had not fallen compared to the first cycle.

The resulting electrophotographic recording material was then charged, exposed and developed to form a visible image by the method described in Example $

Example 11

According to the method described in Example 10, two photoconductive coating compositions were produced, the photoconductor for producing the first coating composition being 4,4 ', 4 "-tris (diethylamino) tetraphenylstannane and for producing the second coating composition diphenylbis (p-diethylaminophenyl) stannane were used. the first coating composition consisted,% on Peststoffe to Z wt.% of dye, to about 6u wt. of photoconductor and the remainder consisting of a binder, and the second coating consisted of 2 Qevn. ° / n of dye to about 53> from photoconductor and the remainder from binder of the type described in Example 1.

Each of the two coating compositions obtained were applied to a substrate using the method described in Example 1 at a coating block temperature of about 10 ° U. The obtained two electrophotographic recording materials 1 and 2 were then tested for electrical sensitivity by the method described in Example 10.

The results obtained show that Sample No. 1 is a negative 10u volt thermoset sensitivity of about r ^ OO and

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00984W1623

Sample # £ had a 100 volt negative sag sensitivity of about 1,700. The two recording materials were then charged, exposed and developed according to the procedure described in Example 1. Clearly visible images were obtained.

Example 12

An electrophotographic recording material was prepared by following the procedure described in Example 10 Use of a coating compound that, based on Solids content, to 2 Grew.> From the dye of Example 10 described type »to about 62 wt.% from p-MäthyIamino- (

phenylgerman as a photoconductor and the remainder of the binder that was described in Example 1! IVps. Applying the obtained coating composition to a substrate was carried out according to the procedure described in Example 1 at a coating block temperature of about 15 ⁰ C. The electrophotographic recording material was by the method described in Example I to electrical üimpfindliohkeit tested The .Ergebnisse showed that the negative 100 Volt sag sensitivity was about 480. With the aid of the recording material obtained, well-seen Dare images were obtained when it was charged, exposed and developed according to the method described in Example 1. "

Example 13

After üem described in Example 10, an electrophotographic recording material was prepared using a coating composition which, based on the the Besohichtungslösungsmittei solids added to 2 wt.> Of dye of the type described in Example 10 and about 40 wt. "/> From Photoconductors of the type described in Example 1 consisted of the remainder of the binder of the type described in Example 1. The application of the

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The coating mass on the substrate was carried out at a coating block temperature of about 15 ° 0. The received Electrophotographic recording material was tested according to the procedure described in Example 10 and it showed found that the 100 volt negative sag sensitivity was 180U. To produce a visible image, the The resulting electrophotographic recording material is charged, exposed and developed in the specified manner.

Example 14

After in Example ■} described l'ype 'j methods described 37i> g of the sensitizing dye in Example were initially u,' dissolved in 42.5 g of methylene chloride for about 2 hours long under stirring. After dissolving the dye, 4.5 g of poly (4,4'-isopropylidenediphenyl carbonate block-oxytetramethylene) were added to the resulting solution with stirring and the mixture was stirred for about 2 hours until the polymer had dissolved. Thereafter, 3 g of photoconductors of the type described in Example 1 were added to the resulting solution, and the resulting mixture was stirred for one half hour. The coating smas se obtained was then applied to an electrically conductive layer support of the type described in Example 1, whereupon the layer obtained was allowed to dry.

The electrophotographic recording material obtained was charged in the dark to a surface potential of 0V and lit according to the method described in Example 1, whereupon it was tested for sensitivity. The positive or negative sensitivities obtained were expressed as the value 10 divided by the exposure in meter-candlestick-seconds, which was used to reduce the surface potential to a potential of 500 V (Ιου ^(r olt · shoulder sensitivity), or to a A potential of 100 V (100 volt sag sensitivity) is required. The results obtained showed that the positive shoulder sensitivity 3200, the positive Durohhang sensitivity 320,

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the negative shoulder sensitivity was 2800 and the negative sag sensitivity 500 ". After the extinguishing exposure had taken place The electrophotographic recording material obtained could be used to form a visible image charge, imagewise expose and develop according to the method described in Example 3. .

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Claims (1)

- · 52 - P A T. E N T A N S P R O C H E (T) Method for producing an electrophotographic recording material from an electrically conductive layer support and at least one heterogeneous photoconductive Layer consisting of a continuous phase of a film-forming polymer and a discontinuous phase with an electrophotographic sensitizing dye having a magnification of at least 2500 times the layer predominantly forms recognizable aggregates, the photoconductive layer having an absorption maximum, the opposite of your absorption maximum one of the same Dye and the same binder formed homogeneous transferable layer is shifted by applying a Coating composition of at least one sensitizing dye and an electrically insulating film-forming binder for the sensitizing dye electrically conductive layer support and drying of the layer obtained, characterized in that a coating compound is used to produce the photoconductive layer consisting of dye, binder and solvent, first the sensitizing dye or dyes are used in their production have been practically completely dissolved in the solvent before the binder is added. 2. The method according to claim 1, characterized in that one a coating compound is used which additionally contains a photoconductor. - ■ 3. Process according to Claims 1 and 2, characterized in that that a pyrylium dye salt of the general formula is used as the sensitizing dye: BAD ORiGSNAL 009844/162? used in which mean: R ₁ and ILp are phenyl radicals or substituted phenyl radicals with at least one substituent consisting of an alkyl radical with 1 to 6 carbon atoms or an alkoxy radical with 1 to 6 carbon atoms, R-z is an alkylamino-substituted wienyl radical with / .an alkyl component having 1 to 6 carbon atoms, X is a sulfur or oxygen atom and Z "~ an anion. 4ο method according to claims 1 and 2, characterized in that that the sensitizing dye is a pyrylium dye consisting of a selenapyrylium dye salt used. 5. The method according to claims T to 4, characterized in that that the sensitizing dye is a 2,4,6-triphenylthiapyrylium dye salt used. 6. The method according to claims 1 to 4, characterized in that that one ala sensitizing dye 4- (4 ~ dimethylaminophenyl) -2,6-diphenylthiapyrylium fluoroborate or 4- (4-dimethylaminophenyl) -2, b-diphenylthiapyrylium peroxide used. 009844/1623 - 54 - 7 · Procedure according to. Claims 1 to 6, characterized in that used as the coating solvent is a halogen-containing short chain having 1 to Hkan 'ö carbon atoms. 8. The method according to claims 1 to 7, characterized in that the coating solvent used is dichloromethane 9. The method according to claims 1 to 8, characterized in that a polycarbonate is used as the polymeric binder » 10. A method according to claims 2 to y, characterized in that there is used as a photoconductor ¹ organic photoconductor, which consists of a) a polyarylalkane of the general formula D.
t J-O-E in which: D, E and G aryl radicals of the phenyl or naphthyl series,
wherein at least one of the radicals D, E and G- is substituted by an amino group, and J is a hydrogen atom, an alkyl radical or an aryl radical the phenyl or naphthyl series, or b) an organometallic compound in which · at least
an aminoaryl radical is bonded to a metal atom of groups IIIa _g IVa or Va of the periodic table or c) a polyarylamine. 00984W1623 11. The method according to claims 2 to 10, characterized in that the photoconductor 4,4 ^1- diethylamino-2,2 ^t dimethyltriphenylmethane, 4-diethylaminotetraphenylmethane,; 4.4. ' , 4 "-Tris (diethylainino) tetraphenylstannane, diphenylbis (p-diethylaminophenyl) stannane or tetra-p-diethyl-; aminophenylgerman are used. 12. The method according to claims 2 to 10, characterized in that that one, based on the total, the coating; solids added to the solvent, the üensibi-. ; lizing dye in a concentration of about U, b to 30 wt. $ 6 and the photoconductor in a concentration-g from about 10 to 80 Gew.70 used. 0098H / 1623