DE2155905C3 - Process for the preparation of a cocrystalline pyrylium dye-polymer complex - Google Patents

Description

The invention relates to a process for the preparation of a cocrystalline complex of a pyrylium dye with an electrically insulating polymer which has an alkylidene diarylene radical in the repeating unit having.

It is well known that photoconductive materials are used in electrophotographic reproduction processes To use recording materials that are exposed to an imagewise exposure to electromagnetic radiation provide a latent electrostatic charge image which develops according to various methods, d. H. can be made visible.

Photoconductive recording materials suitable for performing electrophotographic processes particularly suitable have a photoconductive layer composed of a resinous binder disperse photoconductive insulating material. Elekirophoiographic recording materials can be produced by first applying a layer of an electrically conductive material coated substrate applies a layer of a photoconductive material or the photoconductive Ground directly on an electrically conductive carrier made of metal or another suitable, electrically applies conductive material.

It is also known that the properties of photoconductive layers, in particular the sensitivity and / or the spectral response can be improved by using the photoconductive Layers using photosensitizing Manufactures additives such as those known from US Pat. No. 3,250,615, 3,141,770 and 2,987,395, for example Such photosensitizing additives can be used to produce the photoconductive layers Coating compounds are incorporated. With the help of such additives it is possible to increase the sensitivity of a recording material to radiation of a certain wavelength or, if desired, to improve over a wide range of wavelengths. The mechanism of such awareness has not yet been clarified exactly.

The desired electrophotographic properties of a recording material depend on the Purpose for which the recording material is intended. For example, the Copying documents the spectral electrophotographic response can be such that a The broadest possible color spectrum can be reproduced. If the requirements of the photoconductor does not meet these criteria, an attempt must be made to improve the spectral response by adding to improve a photosensitizing additive. Furthermore, various other Requirements placed on the properties of the photoconductive layer. So should the recording material ζ. B. be able to have a high surface tension and should show a slight dark decay. It is also desirable that the recording material cine high measured in the form of electrical sensitivity or the characteristic curve Sensitivity, low residual stress after exposure and high resistance to Shows fatigue.

The sensitization of photoconductive layers can be carried out in dBr manner that one in the Layers incorporates certain dyes. The addition However, from common dyes to photoconductive layers has only resulted in limited improvement in the The entirety of the electrophotographic properties, d. i.e., there is still a need the sensitivity in the shoulder and sagging area as well as the playback properties during playback -. be of large areas and to achieve a rapid increase.

A further improvement in the properties of electrophotographic Recording materials can be achieved by using recording materials

Ui lien with photoconductive layers in which Aggregates or cocrystalline complexes made from certain polymers, e.g. B. with alkylidene diarylene radicals and dyes, z. B. Pyrylium dyes are generated, the property of photoconductors or sensitizers

Ii have. Such recording materials are made of the US-PS 36 15 414 and 36 15 415 known. In the process known from US Pat. No. 3,615,414 the aggregates or cocrystalline complexes produced by first placing them on a layer support

. · Ο applied layer exposed to solvent vapors suspends. In the process known from US Pat. No. 3,615,415, the process for producing the photoconductive layer used coating compound for the purpose of producing cocrystalline

ji complexes first of all the action of shear forces exposed, eliminating the need to treat the photoconductive layer with solvent vapors. From GB-PS 11 53 506 it is also known, photoconductive layers with cocrystalline complexes

in made of certain polymers and dyes Dissolve the two components in a suitable solvent, apply the solution to a pin Layer support, drying of the layer and, if necessary, aftertreatment of the layer with solvent vapor

π fen to produce.

Finally, from GB-PS 11 91 097 there is a method known, which allows the sensitivity of the US-PS 36 15414 and 36 15415 and GB-PS 11 53 506 known photoconductive layers yet

in to further increase. This method consists in that one first produces photoconductive layers according to the known processes mentioned and these Layers then covered with a solution of a suitable dye. With this last one

ι; The process is thus a second coating stage necessary.

It is characteristic of the known processes mentioned that the photoconductive aggregates or cocrystalline complexes "in situ" in a binder

to be manufactured in that for the end use purpose of the electrophotographic recording material produced therefrom is often not wanted.

The object of the invention is to provide a process for the production of isolated cocrystalline complexes

> i indicate where this is obtained in pure form and then in the most varied of photoconductive Coating compositions can be dispersed as additives.

It was found that the task at hand

hi can be solved by using a pyrylium dye and an electrically insulating polymer, subjected to a certain treatment and the resultant cocrystalline complexes isolated.

The invention is a method for

h) Preparation of a cocrystalline complex of a Pyrylium dye with an electrically insulating polymer, which in the repeating unit a Has alkylidene diarylene radical that thereby kenn ■

draw is that one

a) the dye and the polymer in a halogenated hydrocarbon-containing Lö dissolves solvent in which their solubilities are practically the same,

b) the solution of the dye and the polymer slowly with a halogen-free, non-polar, organic precipitation liquid in which the dye and the polymer are insoluble, combined to precipitate the crystalline dye-polymer complex and

c) separating the complex formed from the solvent and the precipitation liquid

A "cocrystalline complex" means a crystalline compound, the molecules, des Contains dye and the polymer in a cocrystallized state in a single crystal structure with a regular arrangement of the molecules in a three-dimensional lattice.

The method of the invention enables the field of application of the cocrystalline complexes or Expand aggregates as it is no longer necessary to put the aggregates in situ in a special Produce binder system. With the method according to the invention one is free in the choice of desired binder system. In addition, the production of electrophotographic recording materials using the cocrystalline complex obtained by the process of the invention facilitates further treatment a layer applied to a carrier is no longer necessary.

The cocrystalline complexes which can be prepared by the process of the invention can be used in a suitable Binder system are dispersed, which can contain any desired photoconductor. To this Purposes are the complexes of a solution of binder and photoconductor in a solvent, which has practically no dissolving effect on the complexes, added. The resulting mass is processed into a mixture and using conventional coating methods on a carrier upset. After 1 drying, the layer obtained consists of a multi-phase layer, whose heterogeneous character can be seen when looking at them at 2500x magnification, although the Layer can appear optically clear to the naked eye without magnification. Of course you can too macroscopic heterogeneity occur. The complexes containing the dye are expediently located or aggregates in the discontinuous phase, predominantly in a particle size range of about 0.01 to 25 microns. In the case in which the complexes prepared by the process according to the invention to sensitize a special photoconductor, such as. B. zinc oxide, can also be used there are other discontinuous phases which need not fall within the specified range.

Starting from the complexes that can be produced according to the invention, photoconductive layers can also be used a polymeric carrier that forms an amorphous matrix or a continuous phase, which, in contrast to a solution contains a discrete discontinuous phase. The discontinuous phase exists from the cocrystalline complexes which are produced by the precipitation process according to the invention. If the aggregate crystals produced as described above in connection with an organic Photoconductors are used, the resulting photoconductive composition generally only contains two phases, since the photoconductor in the rain) with the ■) continuous phase of the polymeric carrier (auxiliary) forms a solid solution. On the other hand, when a particulate photocoupler, such as. B. zinc oxide is used there can be three phases. In this case there is a continuous polymeric phase, a das

discontinuous phase containing aggregate, such as discussed above, and a further discontinuous phase before arising from the particulate photoconductor consists. Of course, such multiphase compositions can also have further discontinuous phases

I) Contained from trapped impurities. A Another essential feature of the heterogeneous compositions prepared as above is that that the wavelength of the radiation absorption maximum these compositions compared to the

2 (i wavelength of the radiation absorption maximum of a Substantially homogeneous, solid solution produced from the corresponding constituents is considerable is shifted. Such a shift in the absorption maximum in the formation of multiphase

2 ^r > heterogeneous systems for the present invention is generally on the order of at least about 10 nm. If dye mixtures are used, a dye can cause a shift in the absorption maximum to the longer wavelength

«Ι area and another dye a shift of the Cause absorption maximum in the shorter-wave area.

To prepare the aggregate compositions according to the method of the invention, sensitization

Γ) thermal dyes and electrically insulating polymers Materials used. Typical examples of sensitizing dyes that can be used in the manufacture of the Suitable aggregate compositions are pyrylium dyes including the pyrylium, thiapyrylium

4 (i and selenapyrylium dye salts. Examples of such Dyes are general ones. '! formula

R ¹

K-

ir

^r > (i where mean:

R ", R", R ', R ^d and R ¹ ' each (a) a water loffatoni, (b) an alkyl radical with preferably 1 to 15 carbon atoms, e.g. a methyl, ethyl,

Vi propyl, isopropyl, butyl, tert-butyl, amyl,

Isoamyl, hexyl, octyl, nonyl and dodecyl radicals, (c) an alkoxy radical, e.g. B. a methoxy, ethoxy, propoxy, butoxy, amyloxy, hexoxy and octoxy radical, and (d) an optionally substituted one

wi aryl radical, e.g. B. a phenyl and 4-diphenyl radical, an alkylphenyl radical, e.g. B. a 4-ethylphenyl and 4-propylphenyl radical, an alkoxyphenyl radical, z. B. a 4-Äthoxypheiiyl-, 4-Methoxyphenyl-, 4-amyloxyphenyl-, 2-hexoxyphenyl-, 2-methoxy-

h ^r > phenyl and 3,4-dimethoxyphenylresl, a / 3-hydroxyalkoxyphenyl radical. z. B. a 2-Hydroxyäthoxyphenyl and 3-Hydroxyäthoxyphenylrest, a 4-Hydroxyphenylrest, a Halophynylrest,

ζ. B. a 2,4-dichlorophenyl, 3,4-dibromophenyl, 4-chlorophenyl and 3,4-dichlorophenyl radical, an azidophenyl and nitrophenyl radical, an aminophenyl radical, e.g. B. a 4-diethylaminophenyl and 4-dimethylaminophenyl radical, a naphthyl radical, a vinyl-substituted aryl radical, e.g. B. a styryl, iviethoxyslyryl, diethoxystyryl, dimethylaminosiyryl, 1-butyl-4-p-dimethylaminophenyl-1,3 butadienyl and ß-Ä ethyl-4-dimethylaminostyryl radical,

X is a sulfur, oxygen or selenium atom and Ζ ^{θ is} an anionic radical, ζ. B. an anion such as a perchlorate, fluoroborate, iodide, chloride, bromide, sulfate, periodate and p-toluenesulfonate anion, and the pair R ″ and R * and the pair R ^d and R ^c together mean the atoms required to complete an aryl ring fused to the pyrylium nucleus.

Typical representatives of such pyrylium dyes are in in Table I below.

Table 1

Connection no. Name of the connection

1 4- [4-bis (2-chloroethyl) aminophyll-2,6-diphenylthiapyrylium perchlorate

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

3 4- (4-Dimethylaminophenyl) -2,6-diphenylthiapyrylium fluoroborate

4 4- <4-Dimethylamino-2-methylphenyl) -2,6-diphenylpyrylium chlorate

5 4- (4-bis (2-chloroethyl) aminophynyl] -2- (4-methoxyphenyl) -6-phenylthiapyrylium perchlorate

6 4- (4-Dimethylaminophynyl) -2,6-diphenylthiapyrylium suirate

7 4- (4-dimethylaminophenyl) -2,6-diphc nylthiapyrylium-p-toluenesulfonal

8 4- (4-Dimethylaminophenyl) -2,6-diphynylpyr> 'lium-p-toluenesulfonate

9 2- {2,4-Dimethylaminophenyl) -4- (4-dimethylaminophenyl) benz (h) pyrylium perchlorate

10 2,6-bis (4-ethy! Phenyl) -4- <4-dimethyl-aminophenyl) thiapyrylium perchlorate

11 4- (4-Dimethylaminophenyl) -2- (4-methoxyphenyl) -6-phenylthiapyrylium perchlorate

12 4- (4-Dimethylaminophenyl) -2- (4-ethoxyphenyl) -6-phenylthiapyrylium perchlorate

13 4- {4-Dimethylaminophenyl) -2- (4-methoxyphenyl) -6- (4-methylphenyl) pyrylium perchlorate

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

15 2,4,6-triphenylpyryium perchlorate

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

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

Connection no. Name of the connection 18th 4- (3,4-dichlorophenyl) -2,6-diphenyl-
pyrylium perchlorate 19th 2,6-bis (4-methoxyphenyl) -4-phenyl-
pyrylium perchlorate 20th 6- (4-methoxyphenyl) -2,4-diphenyl-
pyrylium perchlorate 21 2- (3,4-dichlorophenyl) -4- (4-methoxy-
phenyl) -6-phenylpyrylium perchlorate 22nd 4- {4-AmyIoxyphenyl) -2,6-bis (4-ethyl-
phenyD-pyrylii barrier mineral 23 4- (4-amyloxyphenyl) -2,6-bis (4-meth-
oxyphenyl) pyrylium perchlorate 24 2,4,6-triphenylpyrylium fluoroborate 25th 2,6-bis (4-ethylphenyl) -4- (4-methoxy-
phenyD-pyrylium perchlorate 26th 2,6-bis (4-ethylpheny!) - 4- (4-methoxy-
phenyD-pyrylium fluoroborate 27 6- (3,4-diethoxystyryl) -2,4-diphenyl-
pyrylium perchlorate 28 6- (3,4-diethoxy-jS-amylstyryl) -2,4-
diphenylpyrylium fluoroborate 29 6- (4-Dimethvlamino-Zi-äthvlslvrvl) -2.4

diphenylpyrylium fluoroborate

o-d-n-AmyM-p-dimethylamino-

phcnyl-1,3-butadienyl) -2,4-diphynyl-

pyrylium fluoroborate

6- (4-dimethylaminostyryl-2,4-diphc-

nylpyrylium fluoroborate

6- [ir-ethyl-j5 (^ 8-bis (dimethylamino-

phcny!) - vinylene] -2,4-diphenyl-

pyrylium fluoroborate

o-d-ButyM-p-dimethylaminophenyl-

1,3-butadienyl) -2,4-diphenylpyryliuni-

fluoroborate

6- (4-dimethylaminostyryl) -2,4-di-

phenylpyrylium perchlorate

6-l ^^ ß-bis (4-dimethylaminophenyl) -

vinylene] -2,4-diphenylpyrylium per-

chlorate

2,6-bis (4-dimethylaminostyryl) -4-

phenylpyrylium perchlorate

6 - (^ - MethyI-4-dimethylaminostyryl) -

2,4-diphenylpyrylium fluoroborate

6- [l-ethyl-4- (4-dimethylaminophc-

nyl) -l, 3-butydienyl] -2,4-diphenyl-

pyrylium fluoroborate

6-iJf ^ -Bis (4-dimethylaminopheny 1) vinylene] -2,4-diphenylpyrylium fluoroborate

6- [l-MethyI-4- {4-dimethylaininophe-

nyl) -l, 3-butydienyI] -2,4-diphenyl-

pyrylium fluoroborate

4- (4-dimethylaminophenyl) -2,6-di-

phenylpyrylium perchlorate

2,6-bis (4-ethylphenyl) -4-phenyl-

pyrylium perchlorate

2,6-bis (4-ethylphenyl-4-methoxyphe-

nylthiapyrylium fluoroborate

ForlsL't / iing

Connection no. Name of the connection

44 45 46 47 48 49 50 51 52

2,4,6-triphenylthiapyrylium perchlorate

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

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

2,6-bis (4-methoxyphenyl) -4-phenyl-

thiapyrylium perchlorate

4- (2,4-dichlorophenyl) -2,6-diphenyl-

thiapyrylium perchlorate

2,4,6-tri (4-methoxyphenyl) thiapyry-

lium perchlorate

2,6-bis (4-ethylphenyl) -4-phenyl-

thiapyrylium perchlorate

4- (4-amyloxyphenyl) -2,6-bis (4-ethylphenyO-thiapyrylium perchlorate

6- {4-dimethylaminostyryl) -2,4-di-

phenylthiapyrylium perchlorate

2,4,6-triphenylthiapyrylium fluoroborate

2,4,6-triphenylthiapyrylium sulfate

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

2,4,6-triphenylthiapyrylium chloride

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

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

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

4-anisyl-2,6-bis (4-n-amyloxyphenyl) thiapyry 1 ium chloride

2 - [/?, /? - bis (4-dimethy! Aminophenyl) -

vinylene] -4,6-diphenylthiapyrylium-

perchlorate

6-0S-ethyl-4-dimethylaminostyryl) -2,4-diphenylthiapyrylium perchlorate

2- (3,4-diethoxystyrylM, 6-diphenyl-

thiapyrylium perchlorate

2,4,6-trianisylthiapyrylium perchlorate

6-ethyl-2,4-diphenylpyrylium fluoroborate

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

2,6-bis (4-amyloxyphenyl) -4- {4-.methoxyphenylj-thiapyrylium perchlorate

6- (3,4-diethoxy-> ethylstyryl) -2,4-diphenylpyrylium fluoroborate

6- (4-methoxy-> ethylstyryl) -2,4-diphenylpyrylium fluoroborate

I ^ -ethylphenylM ^ -diphenyllhiapyrylium perchlorate

Connection no. Name of the connection

_Γ) 72 2,6-Diphenyl-4- (4-methoxyphenyD-

thiapyrylium perchlorate

2,6-diphenyl-4- (4-methoxyphenyl) -

thiapyrylium fluoroborate

74 2,6-bis (4-ethylphenyl) -4- (4-n-amyl-

oxyphenyDthiapyrylium perchlorate

2,6-bis (4-methoxyphenyl) -4- (4-n-

amyloxyphenyl) thiapyryliumpcr-

2,4,6-tris (4-methoxyphenyl) thiapyry-

lium fluoroborate

77 2,4-diphenyl-6- (3,4-diethoxystyryl) -

pyrylium perchlorate

4- (4-dimethylaminophenyl) -2-phenylbenz (b) selenapyrylium perchlorate 2- (2,4-Dimethoxyphenyl) -4- (4-dimethylaminophenyl) benz (b) selenapyrylium perchlorate

4- (4-dimethylaminophenyl) -2,6-diphenylselenapyrylium perchlorate

jo 81 4- (4-dimethylaminophenyl) -2-

(4-ethoxyphenyl) -6-phenylselenapyrylium perchlorate

4- [4-bis (2-chloroethyl) aminophenyl] -2,6-diphenylselenapyrylium perchlorate 4- (4-dimethylaminophenyl) -2,6-bis (4-ethylphenyl) selenapyrylium perchlorate

4- (4-dimethylamino-2-methylphenyl) -4 (i 2,6-diphenylselenapyrylium perchlorate

3- (4-Dimethylaminophenyl) naphtho- (2, l-b) selenapyrylium perchlorate 4- (4-dimethylaminostyryl) -2- (4-methoxyphenyl) benz (b) selenapyrylium-

⁴ 'perchlorate

2,6-1) i (4-diathylaiiiinophenyl) -4-phenylselinapyrylium perchlorate 4- (4-l) imethylaminophynyl) -2- (4-

-, (iilhoxyphcnyl) -6-phcnylthiapyryliuni-

fluoroborate

4-Benzylamino-2-phenylbenz (b) pyrylium perchlorate

4-anilino-2- (4-methoxyphynyl) -

'' naphto (l, 2-b) pyrylium perchlorate

4- (N-Butylamino) -2-phenylbenz (b) -thiapyrylium perchlorate 4- (N-butylamino) -2- (p-melhoxypheholyl) benz (b) pyrylium perchlorate

4- (4-Dimethylaminophenyl) -2- (4-ethoxyphenyl) -6-phenylthiapyrylium fluoroborate and

4- (4-dimethylaminophenyl) -2,6-di-

^hS phenylthiapyrylium oxafluorophosphate

For the production of the aggregates by the process of the invention particularly suitable dye

fe are the pyrylium dye salts of the general formula

where mean:

Ri and R2 each have an optionally substituted phenyl radical with at least one substituent from the group consisting of the alkyl radicals with 1 to 6 carbon atoms and the alkoxy radicals with ■ to 5 carbon atoms,

R _{3 is} an alkylamino-substituted phenyl radical

with 1 to 6 carbon atoms in the alkyl radical and z. B. a dialkylamino or haloalkylamino substituted phenyl radical,

X is an oxygen or sulfur atom and

wherein

Z ^{e has} the meanings given above

As polymers for the production of the isolated A wide variety of substances are suitable for aggregate compositions according to the method of the invention. It has proven to be particularly advantageous if the polymer used is a compound which is described in the repeating unit has a remainder of the formula:

R ₄ R ₇

where mean:

R ₄ and R 5 individually each represent a hydrogen atom, an optionally substituted alkyl radical having 1 to 10 carbon atoms, e.g. B. a methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl or trifluoromethyl radical, or an optionally substituted aryl radical, z. B. a phenyl and naphthyl radical, which can contain a halogen atom or alkyl radicals with 1 to 5 carbon atoms as substituents or together to complete a cyclic hydrocarbon radical including a cycloalkane radical, such as. B. a cyclohexyl radical or a polycycloalkane radical, e.g. B. a norbornyl radical, required number of carbon atoms, the total number of carbon atoms in R4 and Rs is up to 19,

Re and R7 each represent a hydrogen atom, an alkyl radical having 1 to 5 carbon atoms or a halogen atom, e.g. B. a chlorine, bromine or iodine atom, and

Re a divalent remainder of any of the following

Formulas:

Il ο c ο

—O — c — o

r \

and

- CO-CH ₂ -O CH ₃

Il I

- C — Ο — CH-

O -CH ₂ -OCO-

—O-P — O—

The polymers preferably used in the process of the invention are the hydrophobic carbonate polymers, which have the following recurring unit exhibit:

R ₄

—R — C —R — Ο — C — Ο—

R ₅

in the R.

in each case a phenylene radical or a halogen-substituted or alkyl-substituted one Phenylene radical means and

R ₄ and R5 have the meanings given above.

Such compositions are described, for example, in US Pat. Nos. 3,028,365 and 3,317,466.

Polycarbonates which contain an alkylidene diarylei in the repeating unit which, for. B. with Bisphenol A are produced as well as polymeric ester interchange products between diphenyl carbonate and 2,2-bis- (4-hydroxyphenyl) propane (= bisphenol A) are useful for carrying out the process of the invention Particularly suitable such compositions are described, for example, in US Pat. No. 2,999,750.

30 38 874, 30 38 879, 30 38 880, 31 06 544, 31 06 545 and

31 06 546 described. A wide variety of film-forming polycarbonate resins can be used, completely satisfactory results are obtained when using polymeric commercial products which are characterized by an inherent viscosity of about 0.5 to about 1.8.

The following are examples of polymers which .ler for carrying out the process Invention are particularly suitable:

Table II

Polymer no. Name of the polymer

I'olymcrisate no. Name of the polymer

Poly (4,4'-isopropylidenediphenylenco-1,4-cyclonexyldimethyl carbonate)

i'o! y (3, j'-ethylenedioxyphenylene thiocarbonate)

Poly (4,4'-isopropy! Idendiphenylene carbonate-co-terephthalate)

Poly (4,4'-isopropylidene-phenyl-ene carbonate)

Poly (1,4'-isopropylidene diphenene thiocarbonate)

Poly (2,2-butane-bis-4-phenylene carbonate)

Poly (4,4'-isopropylidenediphenylene carbonate-block-ethylcnoxide)

Poly (4,4'-tsopropylidenediphenylene carbonate-block-tetramethylene oxide)

Poly [4,4'-isopropylidene-bis (2-methylphenylene) carbonate]

Poly (4,4'-isopropylidenediphenylene-co-1,4-phenylene carbonate)

Poly (4,4'-isopropylidenediphenylene-co-1,3-phenylene carbonate)

Poly (4,4'-isopropylidenediphenylene-

co-4,4'-diphenylene carbonate)

Poly (4,4'-isopropylidenediphenylcn-

co-4,4'-oxydiphenylene carbonate)

Poly (4,4'-isopropylidenediphenylene-

co-4,4'-carbonyldiphenylene carbonate)

Poly (4,4'-isopropylidenediphenylcn-

co ^^ '- ethyl diphenylene carbonate)

Poly | 4,4'-methylenebis (2-methylphclene) carbonate]

Poly [l, l- (p-bromophenylethane) bis (4-phenylene) carbonate]

Polyf4,4'-isopropylidene diphenylene co-sulfonyl bis (4-phenylene) carbonate]

Poly [l, l-cyclohexane bis (4-phenylene) carbonate]

Poly [4,4'-isopropylidene-bis (2-chlorophenylene) carbonate]

Poly (hexafluoroisopropylidene-di-4-phenylene carbonate)

Poly (4,4'-isopropylidenediphenylene-4,4'-isopropylidenedibenzoate)

Poly (4,4'-isopropylidene dibenzyl-4,4'-isopropylidene dibenzoate)

Poly [2,2- (3-methylbutane) bis ^ -phenylene carbonate]

Poly (2,2- {3,3-dimethylbutane) bis-4-phenylene carbonate]

Poly! l, l- [Hl-naphthyl)] bis-4-phenylene carbonate)

Poly [2,2- (4-methylpentane) bis-4-phenylene carbonate]

Poly [4,4 '- (2-norbornylidene) diphenylene carbonate]

Poly [4,4 '- (hf! Xahydro-4,7-methano-

indan-5-ylidene) diphenylene carbonate]

and

Poly (4,4'-isopropyiidenediphenylene carbonate-block-oxytetramethylene)

The aggregate crystals produced by the process of the invention can be used to improve the

is sensitivity and to expand the spectral Sensitivity range of the most varied of organic photoconductors and inorganic photoconductors including the n- and p-type photoconductors can be used as a typical example of one inorganic photoconductor is zinc oxide. The aggregate crystals can be found in common with many organic and organometallic photoconductive materials are used that have little or virtually no permanent photoconductivity. Representative

2 ^r i ve Representatives of organometallic compounds are the organic derivatives of metals from groups lilac, IVa and Va of the Periodic Table of the Elements, for example those which have at least one aminoaryl group on the metal atom. examples for

w organometallic compounds are the triphenyl pdialkylaminophenylderivate of silicon, germanium, tin and lead, the tri-p-diaikylaminophenylderivatc of arsenic, antimony, phosphorus, bismuth, boron, aluminum, gallium, thallium and indium. Suitable photoconductors

r> of this type are for example in the British Patent specification 12 11 595 and in Belgian patent specification 7 35 334 described.

A particularly suitable class of organic photoconductors are those hereinafter referred to as "organic"

w amine photoconductor «called photoconductor. These organic photoconductors have at least one amino group as a common structural feature. Examples of suitable organic photoconductors which can be spectrally sensitized according to the invention are

• 4> arylamine compounds, such as (1) diarylamines. e.g. Diphenylamine, dinaphthylamine. Ν, Ν'-Diphenylbenzidine, N-Phenyl-1-naphthylamine, N-Phenyi-2-naphthylamine, N.N'-diphenyl-p-phenylenediamine, 2-carboxy-5-chloro-4'-methoxydiphenylamine, p-anilinophenol, N, N'-di-2-

w naphthyl-p-phenylenediamine, as described in the US patent 32 40 597 are described, and (2) triarylamines, such as (a) non-polymeric triarylamines, e.g. B. triphenylamine, Ν, Ν, Ν ', Ν'-tetraphenyl-m-phenylenediamine, 4-acetyltriphenylamm, 4-HexanoyItriphenylamine, 4- Lauroyltriphenylamine, 4-hexyltriphenylamine, 4-dodecyltriphenylamine, 4,4'-bis (diphenyI-aniino) benzil, 4,4'-bis- (diphenyI-amino'-benzophenone, and (b) polymeric triarylamines, e.g. B. poly- [N-4 "- (N, N ', N'-triphenylbenzidine)], polyadipyltriphenylamine, Polysebacyltriphenylamine, Polydeca-

W) methylene triphenylamine, poly-N- (4-vinylphenyI) diphenylamine and poly-N- (vinylphenyl) -iXA'-dinaphthylamine. Other suitable anine-type photoconductors are described, for example, in US Pat. No. 3,180,730.

it Suitable photoconductive substances, which according to the Invention can be sensitized, are described, for example, in US Patent 32 65 496, and these include, for example, those of the following

general formula

R—

N-T-M

where mean:

where mean:

T a condensed or linear, mononuclear or polynuclear, divalent, aromatic radical, ζ. B. a phenyl, naphthyl, biphenyl and Binaphthyl radical, or a substituted, divalent, aromatic radical of these two types, which can be used as substituents e.g. B. an acyl group of 1 to about 6 Carbon atoms, ζ. B. an acetyl, propionyl or butyryl group, an alkyl group with 1 to about 6 carbon atoms, ζ. Β. a methyl, ethyl, propyl or butyl group, an alkoxy group with 1 up to about 6 carbon atoms, ζ. B. a methoxy, ethoxy, propoxy or pentoxy group or a May have nitro group,

M is a condensed or linear, mononuclear or polynuclear monovalent aromatic Rest, ζ. B. a phenyl, naphthyl and biphenyl radical, or a substituted monovalent aromatic radical which can be used as substituents e.g. Legs Acyl group with 1 to about 6 carbon atoms, ζ. Β. an acetyl, propionyl or butyryl group, a Alkyl groups with 1 to about 6 carbon atoms, ζ. B. a methyl, ethyl, propyl or butyl group, an alkoxy group having 1 to about 6 carbon atoms, ζ. B. may have a methoxy, propoxy or pentoxy group, or a nitro group,

Q represents a hydrogen atom, a halogen atom or an aromatic amino radical, e.g. B. such the Formula MNH-,

b is an integer from 1 to about 12 and

R is a hydrogen atom, a condensed or linear, mononuclear or polynuclear aromatic radical, e.g. a phenyl, naphthyl and Biphenyl radical, a substituted aromatic radical which, as a substituent, is an alkyl, alkoxy, acyl or May contain nitro group, or a poly (4'-vinylphenyl) radical, which has a carbon atom of Phenyl group is attached to the nitrogen atom.

Polyarylalkn photoconductors are used to carry out Particularly suitable for the invention. Such photoconductors are described, for example, in US patents 74 000 and 35 42 544 and in French patent 13 83 461. These photoconductors include e.g. B. the leuco bases from Diary! - or Triarylmethane dye salts, the 1,1,1-triarylalkanes, in which the alkane radical has at least two carbon atoms as well as the tetraarylmethanes, in which at least one of the aryl groups associated with the alkane and Methane residues of the two last-mentioned classes of photoconductors that are not leuco bases, are connected, is substituted with an amino group

Preferred polyarylalkane photoconductors are those of the formula:

D. J-C-E

D ₁ E

and G each represents an aryl radical and J represents a hydrogen atom, an alkyl radical or e

an aryl radical, where at least one of the radicals D, E and G is an amino substituent having

The ίο aryl groups connected to the central carbon are preferably phenyl groups, although naphthyl groups are also used) can be. These aryl groups can have substituents, such as alkyl and alkoxy groups, preferably with 1 contain up to 8 carbon atoms, hydroxyl groups and halogen atoms in the o, m or p positions, where a pure o-substituted phenyl group is preferred. The aryl groups can also be linked to one another or be cyclized with the formation of, for example, a fluorene radical. The amino substituent can be replaced by the Formula can be represented:

• /

- N

in which L is in each case an alkyl radical with preferably 1 to 8 carbon atoms, a hydrogen atom, an aryl radical means or in which both radicals L together with the formation of a heterocyclic amino group preferably 5 to 6 ring atoms, e.g. B. a morpholino, piperidino and tetrahydropyrrole group Atoms mean. At least one of the radicals D, E and G is preferably a p-dialkylaminophenyl group. When J is an alkyl group, such an alkyl group generally has 1 to 7 Carbon atoms.

Representative representatives of suitable polyarylalkane photoconductors are in the following table II!

specified:

Table III Connection no. Name of the connection

4,4'-benzylidene-bis (N, N-diethylm-toluidine)

4 ', 4 "-Diaminc-4-dimethylamino-2', 2" -dimethyltriphenylmethane

4 ', 4 "-bis (diethylamino) -2,6-dichloro-2', 2" -dimethyltriphenylmethane

4 ', 4 "-bis (diethylamino) -2', 2" -dimethyldiphenylnaphthylmethane

2 ', 2 "-Dimethyl-4,4', 4" -tris (dimethylamino) triphenylmethane

4 ', 4 "-bis (diethyIamino) -4-dimethylamino-2', 2" -dimethyltriphenylmethane

^ "- BisidiäthylaminoJ ^ -chlor-

2 ', 2 "-dimethyl-4-dimethylaminotri-

phenylmethane

4 ', 4 "-bis (diethylamino) 4-dimethyl-

amino-2,2 ', 2 "-trimethyltriphenyl-

methane

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

909 622/116

ί7

continuation Name of the connection Connection no. 4 ', 4 "-bis (dimethylamino) -2', 2" -di- 10 methyl-methoxytriphenylmethane Bis (4-diethylamino) -l, l, l-triphenyl- 11th ethane Bis (4-diethylamino) tetraphenylmethane 12th 4 \ 4 "-bis (benzyläthylamino) -2 ', 2" -di- 13th methyl triphenyl methane 4 \ 4 "-bis (diethylamino) -2 ', 2" -di- 14th ethoxytriphenylmethane 4,4'-bis (dimethylamino) -l, l, l-tri- 15th phenylethane H4-N, N-dimethylaminophenyl) -1,1- 16 diphenylethane 4-dimethylaminotetraphenyimethane 17th and 4-diethylaminotetraphenylmethane 18th

Another class of photoconductors suitable for practicing the method of the invention, are the 4-diarylamino-substituted chalcones. Typical compounds of this type are the non-polymeric Low molecular weight ketones of the general formula:

N-

> —CH CH-C — R,

in the

Ri and R2 each denote optionally substituted phenyl radicals and in particular those in which R ₂ denotes a phenyl radical of the formula:

R ₄

in the

R3 and R »each aryl radicals, aliphatic radicals with 1 to 12 carbon atoms, ζ, B. alkyl radicals with preferably 1 to 4 carbon atoms, or represent hydrogen atoms.

Particularly advantageous results are obtained when Ri is an optionally substituted phenyl radical and R2 is a diphenylaminophenyl, dimethylaminophenyl or phenyl radical.

Other photoconductors used in connection with the aggregate compositions made by the process of the invention can be used are e.g. B. Rhodamine B, malachite green, crystal violet, phenosafranine, Cadmium sulfide. Cadmium selenide, parachloranil (Tetrachloro-p-benzoquinone), benzil, trinitrofluorenone and tetranitrofluorenone.

Useful in making photoconductive compositions in accordance with the present invention Results obtained when an organic or organometallic photoconductor was used in an amount of at least about 0.5% by weight of the coating solvent total solids added is present The upper limit of the amount present Photoconductor can be varied widely, with up to 99% by weight of total solids being suitable A preferred weight range for the photoconductor is from about 10 to about 80 percent by weight. If the after aggregate compositions obtained by the method of the invention alone as the photoconductive substance are to be used, then of course no photoconductor needs to be added. If so desired In addition to the above-mentioned photoconductors, polymer photoconductors, ζ. B. Poly (N-methylcarbazole) or halogenated poly (N-vinyl carbazole) can be used.

In the method of the invention, one of the pyrylium dyes defined above is used together with one hydrophobic polymer dissolved in an organic solvent system that halogenates one Hydrocarbon Contains Examples of suitable halogenated hydrocarbons include all of those Solvents that have a significant solvent effect on both the dye and the polymer to have.

Particularly suitable solvents are, for. B. chlorinated short-chain alkanes with 1 to about 4 carbon atoms, z. B. dichloromethane, chloroform, carbon tetrachloride, 1,1-dichloroethane, 1,2-dichloroethane and

jo 1,1,2-trichloroethane and chlorinated aromatic hydrocarbons, z. B. chlorobenzene, bromobenzene and 1,2-dichlorobenzene. The conditions under which the Dissolution of the dye carried out are not particularly critical, provided that the temperature no factor for adjusting the relative solubility of the dye and the polymer in the following Precipitation level is. Taking this factor into account, the temperature can be any Temperature below the boiling point of the solvent and below the decomposition temperature of a of the components. In the same way, sufficient stirring can be carried out to keep the solution within a reasonable time to promote. The organic solvent system in which the dye and the Polymer are dissolved, other solvents besides one of the abovementioned solvents can be used contain. The reason for this can be seen by considering the following steps in the process of the invention considered.

After the dye and the polymer in the containing a halogenated hydrocarbon Solvent system have been dissolved, a precipitation liquid becomes slow with the solvent system combined to a precipitation of the dissolved components of the solution on a predetermined Way to effect. This precipitation liquid is characterized by the fact that it is a halogen-free, is non-polar liquid in which neither the dye nor the polymer is soluble. It can be

«) A liquid with a low dielectric constant, z. B. below about 5.0 act. Suitable liquids are e.g. B. Alkanes with about 6 to about 12 Carbon atoms, which can be straight or branched, such as e.g. B. hexane, octane, decane, dodecane

b5 and 2,2,4-trimethylpentane as well as ligroin and mixtures of that.

The precipitation conditions are such that in the presence of the organic solvent system and the precipitation

auxiliary liquid a cocrystalline complex of the dye with the polymer is formed. Around ensure that a cocrystalline complex of the dye with the polymer and not just one another crystalline form of the dye or a precipitated form of the polymer is formed alone, the precipitation conditions must be carefully controlled. The dye and the polymer are first dissolved in a solvent that is good for both compounds, e.g. B. in dichloromethane. Then it will be to the solution a precipitation liquid, e.g. B. hexane, admitted. This precipitation liquid is a nonsolvent for the polymer as well as for the dye. The precipitate is examined to determine if it is the This can be done visually or by customary analytical methods take place and is not the subject of the invention. If it is found that e.g. B. the dye has failed, for example, a solvent, for example toluene, which is a better solvent for the dye than for the polymer, can be added to the solution Alternatively, the amount of dye originally present in the solution can be reduced compared to the amount of polymer. According to another Alternatively, the temperature of the solution can be changed in such a way that the solubility of the Dye increases at a faster rate than that of the polymer. If vice versa If it is found that the polymer has precipitated, the polymer concentration can be reduced preferred solvent for the polymer added or the temperature changed in such a way that that the solubility of the polymer increases compared to that of the dye. The preferred one Method consists in the relative concentrations of the dye and the polymer on each other vote so that they are roughly simultaneously and at the same speed in the form of the cocrystalline Complex failures. To provide a general guideline for the relative amounts of dye and To obtain polymer to be used at the beginning, the respective solubility can at the beginning can be determined, and the concentration of both compounds is chosen so that they are approximately direct is proportional to the solubility. For example, if the dye is less soluble, its concentration in the solvent system will be decreased. if has been found that the precipitate is the cocrystalline complex, the Precipitation liquid added in sufficient amount to complete the precipitation of the product. As already indicated above, the aggregate material described in US Pat. No. 3,615,414 can, due to the occurrence of a spectral The absorption shift can be identified with respect to the absorption spectrum of the dye alone. the Shift appears as a change in the position of the spectral absorption maximum compared to that of the dye in the order of magnitude of at least about 10 nm.

It has already been pointed out that the precipitation liquid is slowly combined with the solvent system in order to precipitate the desired cocrystalline complex. A preferred method to combine the two liquid media is to use one of the liquids at a speed from about 1 to 3 drops per second to the other to drip. Preferably this will be the dye and the polymer-containing solvent system of the precipitation liquid was added dropwise although the reverse However, the same product is obtained at a much slower rate.

The ratio of dye polymer in that containing a halogenated hydrocarbon Solvent system can be varied over a limited range in which one still has one

ίο reliable precipitation of the cocrystalline complex when combined with the precipitation liquid, the proportions of dye to polymer are in generally within the range from about 1:10 to about 2: 1, preferably from 1: 7 to 1: 1, where reliable precipitation of the complex is generally obtained within these ranges. Accordingly, the ratio of precipitation liquid to solvent can be varied over a relatively wide range, values being within the Ranges from about 50: 1 to about 1: 1 are preferred, and values from about 20: 1 to about I3 : 1 are particularly preferred.

After the aggregate material is manufactured, it is removed from the liquid medium in which it is manufactured has been separated The separation can be carried out in the known manner of separating a liquid from a suspended solid, for example by filtration, centrifugation or decanting. A preferred method is to remove the contents of the vessel

jo in a provided with a piece of filter paper Pour Büchner funnel. After removing the liquid using, for example, a The crystals are held back on the paper with a weak vacuum. The remaining liquid will

J5 then by drying the filter paper and his Contents at a suitable temperature of about 40 to about 120 ° C within a period of a few Minutes to about an hour, depending on the temperature used, away from the crystals

After the crystals have been separated from the solvent system and the precipitation liquid, they can be dispersed in a suitable polymeric carrier or binder system as indicated above will. The binder is in a suitable ^r > Solvent dissolved and the aggregate material or crystals are removed in any convenient manner, e.g. By low or medium speed mixers of the types known for this purpose, dispersed therein if necessary

w or, if desired, can go to the solution of the dispersed aggregate crystals containing carrier substance one or more photoconductors or any other desired additives can be added. It should be noted, however, that the aggregate crystals in the dispersed state retain their crystalline form and are not redissolved.

Solvent of choice for the preparation of the photoconductive compositions and those therewith too coating recording materials are, for. B.

bo a range of organic solvents for the polymeric carrier, e.g. B. Alkanes having about 5 to about 12 carbon atoms including the cycloalkanes, such as Pentane, cyclohexane, isooctane, nonane, decane and dodecane, including aromatic hydrocarbons

b5 Hch those substituted by short-chain alkyl groups aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene and propylbenzene, ketones, e.g. B. Dialkyl ketones with 1 to about 3 carbon atoms in

the alkyl radical, such as dimethyl ketone and methyl ethyl ketone and mixtures of these solvents, of course the solvent must have practically no dissolving effect on the crystalline aggregate phase if they is once formed <

Examples of binders that are suitable for use for the production of photoconductive layers are particularly well suited, are polymers with a fairly high dielectric strength, which are good electrically insulating film-forming supports. Materials of this type are, for example, styrene / butadiene copolymers, polyvinyltoluene / styrene copolymers, silicone resins, styrene alkyd resins, silicone alkyd resins, soya alkyd resins, polyvinyl chloride) ^ poly (vinylidene chloride), vinylidene chloride / acrylonitrile mixed polymers), mixed vinyl acetate (vinyl chloride / vinyl chloride) Vinyl acetate / vinyl chloride copolymers, poly (vinyl acetals), e.g. Polyvinyl butyral), polyacrylic and polymethacrylic esters, e.g. Poly (methyl methacrylate), poly (n-outyl methacrylate), poly (isobutyl methacrylate), polystyrene, nitrated polystyrene, polymethyl styrene, isobutylene polymers, polyesters, e.g. B. poly (ethylene alkaryloxyalkylene terephthalate), Cellulose esters, phenol-formaldehyde resins, ketone resins, polyamides, polycarbonates, polythiocarbonates, polyethylene glycol-co-bis-hydroxyethoxyphenylpropane terephthalate) and ring-substituted polyvinyl haloarylates. Process for making resins of this type are already known, for example the styrene alkyd resins according to the US Patents 23 61019 and 22 58423 getting produced. Suitable resins of the type as described in the photoconductive layers produced according to the invention can be used are a copolymer of terephthalic acid and a mixture of 9 parts £ 2 bis [4 - (/ Miydroxyäthoxy) phenyl] propane and 1 part of ethylene glycol; a methyl styrene thermoplastic molding resin; an unsaturated hydrocarbon resin; a vinylidene chloride / acrylonitrile copolymer and duich ester exchange between diphenyl carbonate and 2 ^ -Bis-4-hydroxypheny! propane produced Polycarbonate resins of various molecular weights. Other types of binders which can be used in the photoconductive layers are e.g. B. Materials such as paraffin and mineral waxes.

As layer support materials, those containing a sensitizer produced according to the invention photoconductive layers can be coated are, for. B. All kinds of electrical conductive substrate materials suitable, such as. B. Paper (at a relative humidity of more than 20%), aluminum-paper laminates, metal foils, such as z. B. aluminum and zinc foils, metal plates, e.g. B. aluminum, copper, zinc, brass and galvanized Plates, metal layers, for example made of silver, nickel and tuff, applied by vapor deposition onto paper Aluminum or conventional photographic film layers, e.g. B. those made of cellulose acetate or polystyrene. Electrically conductive materials, such as B. Nickel, can in sufficiently thin layers on transparent Film base can be evaporated in a vacuum, so that electrophotographic recording materials can be produced with it, which from each side these recording materials can be exposed forth. A particularly suitable electrically conductive one Support can be produced by coating a support material such as polyethylene terephthalate with an electrically conductive layer which has an in a resin dispersing containing semiconductors, coated or vapor-deposited onto the substrate in vacuo. Such electrically conductive layers both with even without insulating barriers, z. B. in US Pat. No. 3,245,833. One too A suitable electrically conductive coating can be made from the sodium salt of a carboxy ester lactone of maleic anhydride and a vinyl acetate polymer. These types of electrically conductive

ι ο Layers and processes for their optimal manufacture and uses are described, for example, in US Patents 3,07,901 and 3,262,807.

The layer thickness of the photoconductive composition on the support can be further Limits can be varied. Usually a layer thickness is within the range of about 10 Microns to about 300 microns before drying suitable for purposes of the invention. The preferred The range of the layer thickness is within the range from about 50 to about 150 microns before drying, although useful results can be obtained outside of this range. The resulting dry layer thickness of the topcoat is preferably between about 2 and about 50 microns, although good results can also be obtained with a dry film thickness between about 1 and about 200 microns can.

After the photoconductive record prepared in the manner described above If materials have been dried, they can be stored in any of the known electrophotographic processes in which photoconductive layers are required can be used. One such procedure is the so-called xerographic process. At a Process of this type is an electrophotographic recording material kept in the dark and surface electrostatic charge by placing it under a corona discharge source This even charge is brought about because of the im Dark practically insulating property of the layer, d. H. because of the low electrical conductivity of the Layer in the dark, maintained by the layer. Those on the surface of the photoconductive layer generated electrostatic charge is then through imagewise exposure by means of a conventional Beiich processing method, for example by the contact copying method or by lens projection of an image, selectively derived from the surface of the layer so that a latent electrostatic image in the photoconductive higen layer is formed. If you look at the surface exposed in the manner arises due to the fact that the light energy incident on the photoconductor is too a derivation of the electrostatic charge from the areas of the surface struck by light according to the intensity of the lighting in one special district carries an electrostatic charge image.

The charge image generated by exposure is then developed or transferred to another surface and there developed d. h, the charged or uncharged districts are made visible by having them with a medium treats the electrostatically responsive particle having an optical density contains. The electrostatically responsive developer Particles can be in the form of a dust, i. H. in shape a powder, or in the form of a pigment in a resinous carrier, e.g. B. in the form of a toner, are present. A preferred method of application

such a toner on an electrostatic latent image for large area development consists in the Using a magnetic brush. Methods of making and using a magnetic brush toner applicator are disclosed, for example, in US Pat U.S. Patents 2,786,439, 2,786,440, 2,786,441 and 2,874,063. It can also be a liquid Electrostatic latent image development can be applied. In the case of liquid development the developer particles are placed in an electrically insulating liquid carrier on the one carrying the image Surface applied. Development processes of this type are known and are described, for example, in US Pat. No. 2,907,674. In the dry development process, the most commonly used Method, a permanent record is achieved by selecting a developer particle, which contains a low melting point resin as one of its components. The heating of the powder image leads then to the fact that the resin melts in or on the recording material. This is how the powder adheres permanently on the surface of the photoconductive layer In other cases a transfer of the on the photoconductive layer generated electrostatic charge image on a second support, z. B. Paper, which then after development and after melting (fixing) the End copy is the method of the type specified above are known and, for example, in "RCA Review", Volume 15 (1954), pages 469 to 484.

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

example 1

A 0.2 g serving of the dye 4- (4-dimethylaminophenyl) -2,6-diphenyIthiapyrylium perchlorate and one A 0.2 g portion of poly (4,4'-isopropylidenediphenylene carbonate) was added to 10.0 g of dichloromethane with stirring solved. To the solution of the dye and the polymer were added 5.0 g of toluene, resulting in resulted in partial precipitation of the dye. Sufficient, i. E. about 5 g, dichloromethane added. About 50 g of n-hexane were added to the solvent system consisting of dichloromethane and toluene with stirring admitted. After a few minutes it fell out of the mix a bluish-green, crystalline material from the solvent system and the precipitation solvent. The crystals were separated from the solvent system by placing the contents on a filter paper containing the Buchner funnel and applying a weak vacuum to the using a suction bottle Funnel created. The crystals so separated were then heated by heating at about 100 ° C for about 50 minutes They were dried due to the fact that their spectral absorption maximum is at one wavelength of 685 nm, while that of the dye alone was 590 nm, identified as aggregate crystals

Then, by dissolving 0.58 g of an approximately 9 % By weight of modified poly (vinyl butyrals) containing poly (vinyl alcohol) units and from 0 ^ 40 g of 4,4'-benzylidene-bis (N, N-diethyl-m-toluidine) in 9.0 g of toluene and photoconductive compositions (coating compounds) prepared by adding to each three of these solutions a separate part of the aggregate crystals prepared as above. The weight of that of the first Crystals added to the solution was 0.04 g, that of the crystals added to the second solution was 0.08 g and that of the crystal added to the third solution x 0.12 g. Each of the Zusammensetzungei thus obtained was shaken for about 5 minutes in a metal container with small Stahlkugelt to achieve a gleichmäßigt ^r i mixture. Each of the compositions was then applied in a wet layer thickness of 100 microns to an electrically conductive support consisting of a poly (ethylene terephthalate) film with a copper (I) iodide layer applied thereon, such as ir

ίο the US Patent 32 45 833 described, up brought and dried.

The electrophotographic recording materials thereby obtained were then electrostatically charged under a negative corona discharge source until the surface tension, measured with the help of an: Elektromctersondc, the value of about 600 full had achieved. The charged recording material was then graded through a gray scale Density with a tungsten light source of 3000 ° K exposed. The exposure resulted in a reduction in the surface tension of the recording material at each level of the gray scale from an initial voltage Vo to a somewhat lower voltage V, the exact value of which depends on the respective amount of the the respective area of incident light, measured in lux-seconds (seconds meter candles). The values obtained were then entered in a diagram in which the surface tension V versus the logarithm of the exposure for each step was applied. The respective negative sensitivity of the photoconductive composition can then are expressed by the reciprocal value of the to reduce the surface tension to one fixed, arbitrarily chosen value required Exposure. Below is, if not otherwise indicated, the respective negative sensitivity expressed by the numerical expression 104 divided by the amount required to reduce the surface tension from 600 volts by 100 volts Exposure in lux seconds. The sensitivities of the recording materials thus obtained contributed an increasing concentration in cocrystalline complex crystals 1600, 3200 and 4000. For comparison was a composition as above for that Preparation of the cocrystalline complex described, produced but omitting the polycarbonate. The resulting precipitate then existed just from the dye. The dye crystals were made into a composition containing a photoconductor incorporated and for the production of electrophotographic recording materials as above on a Carrier applied The sensitivities of the recording materials obtained were below 20. It can be seen from this that the Indeed, crystals obtained in the invention contain a cocrystalline complex of the dye and the Represent polymer, as it is indicated in US Pat. No. 3,615,414

_M example 2

The cocrystalline complex crystals prepared as in Example 1 were made into a photoconductive composition similar to that of Example 1, incorporated, this time a polystyrene resin having a different average molecular weight than Binder for the photoconductive composition and cyclohexane as a coating solvent were used. The weight of the used

Aggregate or the cocrystalline complex crystals used was 0.12 g. The coating conditions were the same as in Example I. The The sensitivity of the recording material obtained was 800, while the sensitivity of one recording material made only from the dye instead of the cocrystalline complex was 0. This was because the dye alone was the photoconductor in a polystyrene binder system not sensitized.

Example 3

The procedure of Example 1 for the preparation of cocrystalline complex crystals was repeated. This time, however, a 2.5% by weight / volume% solution of the dye in dichloromethane was prepared, to which a 2.5% by weight, 7% by volume solution of the resin, likewise in dichloromethane, was added. The dye and resin used were the same as in Example 1. No further solvent was added to the dye-polymer solution. A certain amount of ligroin with a boiling range of about 63 to 75 ° C. was then added dropwise to the solution, the amount being about 2.5 times the volume of the solvent used to dissolve the dye and the polymer. As in Example 1 occurred precipitation of the cocrystalline complex on, then the crystals were isolated and dried Then, the crystals were used for the production of three recording materials as m Example 1. These recording materials each had a electrophotographic Ansprechempfindiichkeit on to that of Example 1 corresponded . The crystals were identified by the occurrence of the shift in wavelength of maximum spectral absorption i ^r> tion than the complex.

Example 4

The procedure described in Example 3 was repeated, this time using 2.0% by weight / volume% solutions of the dye and the polymer and 1,2-dichloroethane were used as solvents. The precipitation liquid was η-hexane, the amount of which was about Was 2.4 times the volume of the solvent used. Crystals similar to those of Example 3 were similar, showing the characteristic spectral absorption shift of the aggregate or had cocrystalline complex and the recording materials produced therefrom accordingly bestowed high sensitivities. 5 «

Example 5

The procedure of Example 3 was repeated, this time at twice the weight concentration Polymer was used in the starting solution. The precipitation liquid was the liquid of the example 4, their amount was 2.4 times the volume of the solvent. The results obtained corresponded those as obtained in Examples 3 and 4. m>

Example 6

Using the dye and the polymer according to Example 1, a dye-polymer solution was obtained produced, the 2.0 wt .-% of both dye and polymer in dichloromethane The order of addition according to Example 1 was reversed by adding the dye-polymer solution was added dropwise to the precipitation liquid. The precipitation liquid was the ligroin of Example 3, its volume was 3 times that of the dye-polymer starting solution. Immediately after the solution was added to the precipitation liquid, aggregate crystals began to form form. After the entire volume of the initial solution was added, the crystals became separated and dried as in the previous examples. The procedure of this example is preferred since the total precipitation took a much shorter time. Identification of the crystals as Aggregate crystals were carried out as above, as was the preparation of an electrophotographic Element that showed a correspondingly high sensitivity in the test.

Example 7

A solution was made from the following ingredients:

4- (4-Dimethylaminophenyl) -2,6-diphenylthiapyrylium fluoroborate (Dye II) 2.7 g

4- (4-Dimethylaminophenyl) -2- (4-ethoxyphenyl) -6-phenylthiapyrylium fluoroborate
(Dye III) 0.3 g

Polycarbonate resin 3.0 g

Methylene chloride 525 ml

Toluene 375 ml

This solution was added dropwise to 4,500 ml of hexane, which resulted in the formation of aggregate crystals. The aggregate resultant precipitate was separated by suction filtration, and 16 hours at 6O ⁰ C dried the aggregate dry crystals were then used to prepare the following compositions:

Together- ingredients I.
Amount | Settlement I. A Chlorinated polyethylene 1.2 g I. (65.8% Cl) (Binder) I. 4,4'-diethylamine-2,2'-dimethyl- 0.8 g I. triphenylmethane (photoconductor) I. Aggregate crystals 0.2 g I. toluene 12 ml I. B polyvinyl vinylidene chloride 1.2 g I. 4,4'-diethylamine-2,2'-dimethyl- 0.8 g I. triphenylmethane (photoconductor) 1 Aggregate crystals 0.2 g I. toluene 12 ml I. C poly (vinyl m-bromobenzoate-co- 1.2 g vinyl acetate) 4,4'-diethylamino-2,2'- 0.8 g dimethyl triphenyl methane (Photoconductor) Aggregate crystals 0.2 g toluene 12 ml For any of the above compositions were porcelain balls with a diameter of 0.32 cm (½ inch) was added and two at a time

Shaken for hours in a high frequency, low amplitude vibratory mixer. Each of the The resulting formulations were applied to a wet film thickness of 0.1 mm (0.004 inches) Nickel (optical density 0.4) coated substrate

applied for the production of an electrophotographic recording material which, as described above, was examined for its sensitivity. The sensitivity values obtained are as follows specified.

Recording material
No.

composition

Positive sensitivity. Negative sensitivity

in the shoulder- in the slack- in the shoulder- in the through

area

area

area

slope area

A.
B.
C.

9000

9,000

10,000

Dye II
Dye III
Polycarbonate resin
Methylene chloride
toluene

0.44 g 0.06 g 3.2 g 350 ml 250 ml

A solution was added dropwise to 3000 ml of hexane and with the aid of a dry ice / acetone bath cooled to -80 ° C. The other solution was added to 3000 ml of hexane, which was kept at room temperature (about 23 ° C) was maintained. The resulting aggregate precipitates were collected by suction filtration. When the two precipitates were examined, it was found that the one produced at -80 ° C was a lot had finer particle size than that made at room temperature.

Example 9

Four solutions were made from the ingredients listed below:

Solution Solution Solution Solution No. 1 No. 2 No. 3 No. 4

Lexan 145
Dye II
Dye III
Methylene chloride
toluene

3.5 g
0.44 g
0.06 g
350 ml
250 ml

3.5 g
0.44 g 0.06 g 350 ml 250 ml

1.2 g 0.15 g 0.02 g 118 ml 83 ml

13.3 g 6.65 g

1750 ml 1250 ml 1600
1200
1300

8000
5000
5700

400
550
630

Similar results were also obtained when using dye I and 4- (4-dimethylaminophenyl) -2-

(4-ethoxyphenyl) -6-phenylthiapyrylium perchlorate (dye IV) was obtained. :> o

Example 8

Starting solutions were prepared, each containing:

25th 40

55

The solution No. 1 was added dropwise to 3000 ml of heptane, the solution No. 2 became 3000 ml Cyclohexane was added dropwise, the solution No. 3 was added dropwise to 1000 ml of 2,2,4-trimethylpentane and the Solution # 4 became 15,000 ml of a solvent mixture of branched chain isoparaffinic hydrocarbons with a boiling point range of 160-177 ° C was added dropwise. The aggregate precipitations obtained in this way were again collected by suction filtration. The investigation of this precipitation in the binder / photoconductor systems of Example 7 showed that the compositions obtained had high xerographic sensitivity

Example 10

A mixture of 0.9 g of polyvinyl carbazole, 0.2 g of the aggregate crystals of Example 7 and 12 ml of benzene prepared by mixing the polyvinyl carbazole in the solution was stirred in, the aggregate crystals added and with a vibratory shaker for two hours Moving using porcelain balls with a diameter of 0.32 cm. The received Formulation was then applied at 27 ° C in a wet layer thickness of 0.1 mm at 27 ° C with a Substrate provided with nickel coating (optical density 0.4) applied. A comparative coating was also applied made, the 1.8 g of polyvinyl carbazole, 30 ml of benzene, 0.2 g of polycarbonate resin and 0.18 g of the dye II and 0.02 g of Dye III. The Lexan and the dye of this composition became simple solved together and lay in the form of a homogeneous combination, not in the form of a cocrystalline Complex, before. This comparative coating was also used to make an electrophotographic Recording material, as described above, used, and the two recording materials were examined for their sensitivity. The recording material containing the aggregate had a positive 100 V shoulder sensitivity of 700 and a sensitivity in the toe range of 100. The comparative recording material that is not an aggregate exhibited 100V shoulder sensitivity which was lower than that of the recording material containing the aggregate by more than ten times. The 100 V sensitivity in the toe area of the comparison material was 0.

Claims (1)

Patent claims: 1. Process for the preparation of a cocrystalline complex of a Pyryliumfarbsioffes with a electrically insulating polymer containing an alkylidene diarylene radical in the repeating unit having, characterized in that one a) the dye and the polymer in a containing a halogenated hydrocarbon Solvents in which their solubilities are practically the same, dissolves, b) the solution of the dye and the polymer slowly with a halogen-free, non-polar, organic precipitation liquid in which the dye and the polymer are insoluble are combined to precipitate the cocrystalline dye-Polymeris.at complex and c) separating the complex formed from the solvent and the precipitation liquid. 2. The method according to claim 1, characterized in that the polymer is a compound is used, which has a remainder of the formula in the repeating unit: 'ι * R ₇ ■ Κ where mean: R ₄ and Rs individually each represent a hydrogen atom, an optionally substituted alkyl radical with 1 to 10 carbon atoms or an optionally substituted aryl radical, or together the number of carbon atoms required to complete a cyclic hydrocarbon radical, the total number of carbon atoms in R ₄ and R5 being up to 19 amounts to, Rh and R; each a hydrogen atom, an alkyl radical having 1 to 5 carbon atoms or a halogen atom and Rb is a divalent residue of one of the following Formulas: Il ο (ο Il O C O O Il (O O Il CO (II,
O (II, cn C) O C. - O- O P.
I. O I.
O 3. Process according to Claims 1 and 2, characterized in that the polymer is used a carbonate polymer used, the repeating Incorporating the formula has: R, O i il R C ROCO where mean: R is a phenylene resl and R ₄ and R5 individually each have a hydrogen atom, an alkyl radical with 1 to about 10 carbon atoms or an aryl radical, or together the number of carbon atoms required to complete a cyclic hydrocarbon radical, the total number of carbon atoms in R ₄ and R- being up to 19 protrudes. 4. Process according to Claims I to 3, characterized in that one is used as the pyrylium dye Pyrylium or thiapyrylium dye salt is used. 5. The method according to claim 4, characterized in that there is a compound as the dye salt the formula used: R ₁ R, / where mean: Ri and Ri each have a plastic frame, R3 an alkylaminosubstituicrien Phunyl- rcst with I to b carbon atoms in dom Aikyl residue, X is an oxygen or sulfur atom and Ζ ^{θ is} an anionic radical. b. Process according to Claims 1 to %, characterized in that an organic liquid with a dielectric constant of less than about 5 is used as the precipitating liquid. 7. The method according to claim 6, characterized in that an alk; « 11 with about 6 to about 12 carbon atoms, I.igroin or a mixture thereof is used as the filling liquid. 8. Process according to Claims 1 to 7, characterized in that an organic solvent system is used used, that of a chlorinated alkane and / or a chlorinated aromatic Hydrocarbon. C O (H