DE2316033C3 - 08/08/72 Japan 78779-72 Electrophotographic recording material - Google Patents

Description

3 4

In order to explain the properties of the photoconductor, photographic material obtained give the F i g. 1 and 2 are characteristic curves obtained by mixing an organic photoconductor with built-up voltage versus the charging time for a predetermined amount of chlorinated paraffin, the «Electrophotographic photo-receiving plate, the occurrence of fatigue failure or de» · Veraus an organic photoconductor, · consists, again. 5 Prevent deterioration or destruction or under-die photoconductive compressions according to the invention, so that they can be used as photocomposing can first dissolve the desired properties by mixing 100 conductive layers an organic photoconductor, e; wa 0.1. Although the mode of action of the chlorinated to 20 parts by weight of a sensitizing chemical paraffin is unknown, it has been found that one sators, about 0.02 to 4 parts by weight of an optical io photoconductive layer, which an organic Sensibüisators and 20 to 50 parts by weight of chlorinated Phctoconductor as the main ingredient, in operation Paraffins can be obtained with each other. Then that becomes a negligible or negligible fatigue failure Mixture in chlorobenzene, toluene, benzene or methyl - a negligible deterioration or Lene chloride etc. dissolved and mixed together well. Destruction due to electrical charge Organic photoconductors, which are suitable for the invention or the exposure with the addition of chlorinated the composition according to the invention has been found to be suitable, paraffin finds out. Even if they are repeated as photos z. B. Poly-N-vinylcarbazole, charge-transfer-mole-sensitive material for a toner or charge Cooling complexes, such as poly-N-vinylcarlazole-tetrachloro-transfer copying, can be used with the erfinp-benzoquinone or Poly-N-vinyJcarbazoI-Tetracyano- the composition according to the invention always the pre-quinone dimethane, Poly-N-vinylcarbazole derivatives, 20 specific function as photosensitive material such as nitrated poly-N-vinylcarbazole, polyvinyl anthra- meet. Even if they are on a photosensitive cen, polyacenaphthylene, anthracene, pyrazoline, oxa paper is applied, a clear picture without zol, triazole or hydrazone. About the light sensitivity decrease in his image due to exposure These photoconductors can be affected by room light, fatigue failure or the chemical compounder Sensitizer and / or an optical deterioration or destruction can be obtained. Sensitizer can be added. It was also found that by adding Various kinds of other additives can be added, from 20 to 35 parts by weight of chlorinated paraffin other properties of the electrophotographic and 5 to 30 parts by weight polystyrene, styrene mixed recording material to improve. A special polymer or a mixture thereof becomes 100% not only into a monomolecular organic photo- 30 parts by weight of an organic photoconductor ladder prefers a suitable polymer, such as poly- the occurrence of fatigue failure and the vermethylene methacrylate, Polycarbonate, cellulose nitrate deterioration or destruction can be avoided or cellulose acetate, as a binder to a film, but that also a high sensitivity and to ensure education incorporated. a high image quality is guaranteed.

Examples of preferred chlorinated paraffins are 35 Suitable polystyrenes and styrene copolymers

those which sate 41 to 52 weight percent chlorine are z. B. Acrylonitrile-styrene mixed polymers,

contain, or those which 40 to 65 weight acrylonitrile - butadiene - styrene copolymers and

percent chlorine. Acrylic ester-styrene copolymers. It can

These chlorinated paraffins contain about 8 to also a mixture of two or more of these pro-

18 carbon atoms and 40 products can be used depending on the chlorine content.

in liquid or solid form. Taking into account the amount of polystyrene or styrene to be added the compatibility with the organic photo copolymer or mixtures thereof should be in In particular, a liquid chlorinated range of 5 to 30 parts by weight per 100 parts by weight of paraffin is used with a chlorine content of 40 to 65 parts by weight of the organic photoconductor. Outside of percent preferred. There can also be two or more 45 of this range, the effect of the addition of polychlorinated Paraffins are mixed together. styrene, styrene copolymers or a Ge-Die Amount of chlorinated paraffin, which is mixed with chlorinated paraffin, The organic photoconductor is mixed, should be in like the excellent improvements of the light area from 20 to 50 parts by weight per 100 weight sensitivity and image quality, do not divide completely of the organic photoconductor Hsgen. This then folds.

because, in summary, the addition of chlorinated paraffin contributes to the

an amount of not more than 20 parts by weight the certain amount of chlorinated paraffin to prevent

Ertnüdun the occurrence _o sversagens or comparison tion of fatigue failure or deterioration

cannot prevent deterioration or destruction of an organic photoconductor

while the addition of chlorinated paraffin in a 55 and contributes to the increase in the built-up tension,

However, in an amount exceeding 50 parts by weight, it tends to increase photosensitivity

Decrease in photosensitivity and a decrease and deteriorate the image quality,

Considerable decrease in the built-up tension by adding optimal amounts of polystyrene,

works, although the occurrence of the fatigue failure styrene copolymer or a mixture thereof

or the deterioration or destruction can effectively 60, the above-mentioned tendency to decrease

can be prevented. It has been experimental of photosensitivity and deterioration

confirmed that the addition of chlorinated paraffin of the image quality can be prevented, and at the same time

outside the upper and lower limit for which the built-up voltage of the photoconductor can increase

practical use of photoconductors in one. The best results can be achieved by adding

electrophotographic recording material and a mixture of chlorinated paraffin, which

was suitable. contains about 48 percent by weight of chlorine, and IPoIy-

As described above, the organic styrene can be obtained into an organic photoconductor

photoconductive composition for becoming electro-.

The organic photoconductive composition of the present invention is illustrated by the following Examples described in more detail.

At s ρ i el 1

Between poly-N-vinylcarbazole and tetrachlorop-benzoquinone a charge transfer reaction is carried out in a weight ratio of 1: 1.27, to obtain a charge-transfer molecular complex. A mixture of 100 parts by weight of the charge transfer molecular complex, 0.5 part by weight of 3,5-dinitrosalicylic acid as a chemical sensitizer and 0.5 part by weight of brilliant green as an optical sensitizer was added to 1800 parts by weight of chlorobenzene solved. The resulting solution was divided into seven equal parts. A chlorinated paraffin, which Containing 41 weight percent chlorine, each part was added in the amount given in Table I per 100 parts by weight of the charge transfer molecular complex was added. Each solution was deposited on aluminum plate substrates applied to seven photosensitive plate samples after the solution has dried produce with a film thickness between 5 and 6 μπι. as

Table I.

sample Amount added
chlorinated
Paraffins Fatigue index (%)
due to the
Exposure with
400 lux sec. 3 minutes No. (Parts by weight) 1 minute 21 1 0 44 13th 2 10 15th 3 3 20th 2 1 4th 25th 0 0 5 35 1 2 6th 45 0 0 7th 50 2

According to this definition, the fatigue indices of sample 1 are as follows:

44% 1 minute after the start of charging (mainly deterioration or destruction in the built-up tension, as shown in FIG. 1) and

21% 3 minutes after starting charging (mainly a deterioration in saturation voltage).

Similarly, the fatigue indices of Samples 2 to 7 were measured based on exposure. The corresponding results are also summarized in Table I.

From Table I it can be seen that a photoconductive composition obtained by adding not less than 20 parts by weight of chlorinated paraffin for 100 parts by weight of an organic photoconductor suffered essentially no exposure fatigue failure. The addition of not less than 50 parts by weight of chlorinated paraffin was due to the considerable decrease unsuitable for both photosensitivity and the initial tension built up.

Example 2

The procedure of Example 1 was essentially repeated except that the chlorinated Paraffin was replaced by a chlorinated paraffin containing 52 weight percent chlorine. There were so samples 8 to 14 with that given in Table II Preserved composition.

Table II

35

40

F i g. 1 gives the results of the measurement of the electrophotographic characteristic curves of sample 1 with the aid of a paper analyzer (rotational speed of a sample turntable: 13 rpm; corona charging voltage: -500 V; light source: WoIfram filament lamp; lighting: 9 lux). The curves a, b and c in Fig. G. 1 shows the results obtained when light of 0.1000 and 4000 lux · sec. Was irradiated on the surface of the sample before measurement. It goes from Fig. 1 clearly shows that a sample containing no chlorinated paraffin suffered great fatigue (deterioration or destruction of the voltage initially built up and a decrease in saturation voltage). The fatigue index due to exposure is more accurate by the formula

100 ( ^c

sample Amount added
chlorinated
Paraffins Fatigue index (%)
owing to
repeated
use 3 minutes No. (Parts by weight) 1 minute 23 8th 0 29 16 9 10 18th 0 10 20th 3 1 11th 25th 2 2 12th 35 0 0 13th 45 1 1 14th 50 0

The electrophotographic properties of Sample 8 were repeatedly measured as in Example 1 using the paper analyzer. The results obtained in this regard are shown in FIG. 2 indicated where the curves d, e and / in F i g. 2 «show the results of the first, second and third successive measurements. It is clear from the figure that a sample without the addition of chlorinated paraffin suffered severe fatigue due to its repeated use (mainly due to charging. The fatigue index at due to exposure is given by the formula

defines where Vl is the built-up voltage of a sample, which light of 4000 lux-sec. was exposed before the measurement, and V _{0 denotes} the built-up voltage of a sample without prior exposure.

(W

100 (%)

defines where K _{0 is} the voltage built up on the sample during the first measurement and V _{R is the} build up

Mean tension of a sample in the third measurement.

According to this definition, the fatigue indices of sample 8 are as follows:

29% - 1 minute later and
23% - 3 minutes later.

Similarly, the fatigue indices of Samples 9 to 14 became due to their repeated use measured. The corresponding results thus obtained are summarized in Table II.

It can be seen from Table II that a photosensitive Material containing not less than 20 parts by weight of chlorinated paraffin is essentially did not suffer fatigue.

Example 3

A mixture of 100 parts by weight of poly-N-vinylcarbazole, 10 parts by weight of 2,4,7-trinitrofluorenone (a chemical sensitizer) and 30 parts by weight chlorinated paraffin, containing 45 weight percent chlorine, was added to 1,800 parts by weight of tetrahydrofuran dissolved to obtain a photosensitive solution. The surface of a support made from an aluminum plate was coated with this solution and then to prepare a sample of a photosensitive Plate dried. The fatigue indices of the sample due to exposure to light were as in the example 1 indicated measured. The corresponding results were 2% in 1 minute and 0% in 3 minutes, whereas the corresponding fatigue indices of a comparative test without the addition of chlorinated one Paraffin was 33% (1 minute) and 20% (3 minutes).

Example 4

The procedure of Example 3 was essentially repeated with the exception that poly-N-vinyicarbazole was replaced by polyacenaphylene. The measured fatigue indices of the sample due to the exposure to light was 1% after 1 minute and 2% after 3 minutes.

Example 5

A charge transfer molecular complex was obtained by reaction between poly-N-vinylcarbazole and tetrachloro-p-benzoquinone in a weight ratio of 1: 1.27. A mixture of 100 parts by weight of the charge transfer molecular complex, 2 parts by weight of 3,5-dinitrosalicylic acid (a chemical sensitizer) and 0.5 part by weight of brilliant green (an optical sensitizer) was dissolved in 2,000 parts by weight of chlorobenzene. The solution thus obtained was divided into seven equal parts. Chlorinated paraffin containing 48 weight percent chlorine was added to each portion in the amounts shown in Table III based on 100 weight parts of the charge transfer molecular complex. Each solution was applied to electroconductive paper and then dried. to produce seven types of photosensitive paper with substantially the same film thickness of 6 to 7 μηο

Table III

5 sample Amount added
chlorinated
Paraffins Built up
tension Half decay
exposure No. (Parts by weight) (-Volt) (Lux sec.) 15th 0 194 12th ίο 16 20th 310 41 17th 30th 305 41 18th 35 271 48 19th 40 172 57 20th 50 151 65 15 21 60 70 132

Table III gives the voltage built up and the half-decay exposure (photosensitivity) of each of the

ίο photosensitive papers, measured with the help of a Low-speed dynamic system paper analyzer (rotational speed a sample turntable: 13 rpm; Corona voltage: -4500 V; Light source: tungsten filament lamp; Exposure: 9 lux) again.

From Table III it is clear that the photosensitive Papers with 20 to 35 parts by weight of chlorinated paraffins (samples 16 to 18) a considerable amount Exhibit increase in built-up stress and half-decay exposure. It also appears that photosensitive papers having not less than 50 parts by weight of chlorinated paraffin become one significant decrease in the built-up stress, but a significant increase in Halb decay exposure lead, so that they are unsuitable for practical copying purposes.

Furthermore, a polystyrene was added to the solution of sample 16 (with the addition of 20 parts by weight chlorinated Paraffins) in the amounts given in Table IV, based on 100 parts by weight of the above Molecular complex, added. Each solution so prepared was printed on electroconductive paper and then applied to make five types of photosensitive paper as shown in Table IV

* 5 indicated, dried.

Table IV

Added Built up
tension Half
disintegrate
exposure So
sample lot
chlorinated
Paraffins (Weight <Volts) (Lux ■ sec.) No. parts) 310 41 ⁵⁵ 16 0 (Comparison) 315 12th 16-1 5 397 9 16-2 10 378 10 6o ¹⁶ - ³ 20th 305 13th ⁶⁰ XbA 30th 260 49 16-5 40

The built-up tension and the half-decay
exposure of each photosensitive paper was
under the same conditions as stated above
measured. The corresponding results are
Table IV summarized.

509 615 /:

It is clear from Table IV that the disadvantages of photosensitive paper when added alone of chlorinated paraffin with a tendency to increase half-decay exposure (decrease in photosensitivity) and the decrease in image quality completely by the further addition of 5 to 30 parts by weight Polystyrene could be turned off. Furthermore, the photosensitive paper exhibited such an addition, e.g. B. Samples 16-2 and 16-3, a better tendency in both photosensitivity as well as in image quality than the light sensitive Paper (sample 15 in Table III) without this addition on. On the other hand, there was a favorable tendency of increasing the tension built up in comparison with photosensitive paper with the sole addition of chlorinated paraffin. It is also to be noted that this photosensitive paper did not suffer any fatigue.

Similar results were obtained when polystyrene was added to a sample containing 30 to 35 parts by weight of chlorinated paraffin per 100 parts by weight of the organic photoconductor obtained. With 40 or 50 parts by weight of chlorinated paraffin, however, one could a particularly pronounced effect cannot be achieved.

Example 6

A mixture of 100 parts by weight of poly-N-viny! - carbazole, 2 parts by weight of picric acid (a chemical Sensitizer) and 0.3 part by weight of Crystal Violet (an optical sensitizer) were dissolved in 2000 parts by weight of chlorobenzene. The product was available in three equally divided solutions. A chlorinated paraffin was added to one of these solutions with a Chlorine content of 41 percent by weight and an acrylonitrile-butadiene-styrene copolymer, as indicated in Table V, added. Then the solution obtained was applied to an electroconductive treated paper, to make a photosensitive paper, sample 22. Similarly, samples 23 were made and 24 using a different portion of the solution each, chlorinated paraffin only or nothing was added. The stresses built up and the half-decay exposures of the samples 2. to 24 were, as indicated in Example 5, measured. The corresponding results thus obtained are shown in Table V summarized. It is clear from Table V that the electrophotographic characteristic curves of a light-sensitive material by adding chlorinated paraffin and styrene copolymer are excellent and do not suffer any fatigue.

Table V

sample Granted
lot
chlorinated
Paraffins Be Granted
lot
Styrofoam
Mixed poly
merisat on
built
Chip
tion HaIb-
decaying
exposure
tion (Weight (Weight (Lux· No. parts) parts) (-Volt) Sec.) 22nd 20th 15th 316 30th 23 20th 0 263 99 (Ver cleich) 24 0 0 167 32 (Ver same) i s ρ i e I 7

The procedure of Example 6 became more substantial

as repeats, except that poly-N-vinylcarbazole of sample 22 was replaced by polyacenaphthylene and that the acrylonitrile-butadiene-styrene copolymer of sample 22 was replaced by an acrylic acid ester-styrene copolymer. The built Tension and the half-decay exposure de; photosensitive paper were made with the after measured the following excellent results:

Built-up voltage -310 volts

Half decay exposure 170 lux

Sec.

In addition, the photosensitive paper was strong in fatigue resistance.

From the foregoing it is clear that eim A photoconductive composition for use in electrophotography containing 100% by weight parts of an organic photoconductor and 20 to 50 parts by weight of chlorinated paraffin, practically no Er fatigue failure or deterioration or destruction due to the electrical charge or the Exposure suffers. Accordingly, the composition according to the invention always has its predetermined " Function off even when used repeatedly as a light-sensitive material in the toner or charge trans fer copying is used.

1 sheet of drawings

Claims (4)

j 2 3 tire pickup or exposure; there occurs other «toe noticeable deterioration claims: mtt; ^^ built tension and a 1. Electrophotographic recording- substantial totally with a photoconductive layer that has a 5 w « ^η / ^η ^^ ί. _In \ eSnenisΓώ ^ Αί organic photoconductor, possibly a binding application Af ^ -J? ^ STme ^ S f Qr medium and contains a chlorinated paraffin, the a- organic £ «™ £ ^ ZT" £? Characterized by that the photo- repeated JT - _ei _ kitable layer 20 to 50 parts by weight of a gxapluschen copying process ^ e em chlorinated paraffin with a chlorine content of "charge ^^^" ^ J 40 to 65 weight percent per 100 parts by weight failure
Even if it contains photoconductor. 2. Recording material according to claim 1, da- if «s as material jf ^ characterized by that the photoconductive one is used, admits it Layer 20 to 35 parts by weight of the chlorinated »5 problem, such as the decrease in the ^ Paraffins and as a binding agent 5 to 30 parts by weight of fatigue failure due to exposure to light a polystyrene, a styrene copolymer Zimmerlicht. t-meets ^ n or a mixture thereof. The German Auslegescimft 1 497 U2 concerns en 3. Recording material according to claim 2, eJekrrophotographiSchesL ^ f _e SS _e ί ' ₀ Τ' ^1, characterized in that the photoconductive "o a photole.tfah.gen layer, en hooking" Jj £ y layer as a styrene copolymer is an acrylic More Anthracendenvat as PhotoleiiiAs an example of a nitrile-styrene copolymer, an acrylonitrile-Bu- for a manufacturer, chlorinated paraffin tadiene-styrene copolymer or an acrylic is called. concerns before containing acid ester-styrene copolymer. The German Auslegeschrift 1 497 031betntt also 4. Recording material according to claim 1 and 2, * 5 if an electrophotographic Aufze.chnungsmadsame characterized in that the photoconductive ierial with a photole.tfah.gen layer of ener Layer a chlorinated paraffin with a chlorine leuco base as a photoconductor, a transparent one content of 48 percent by weight and polystyrene binder and a sensitizer. Chlonertes contains paraffin is called Bmdem.ttel. 30 Thus, according to these German interpretations chlorinated paraffin for a very different purpose than used according to the invention. According to the German layout 1497182 50 to 200 parts of chlorinated paraffin are used 35 100 parts of the polymer added while according to The invention relates to an electrophotographic recording material similar to Examples VIII and IX of the German slege recording material with photoconductive writing 1 497 037 schatzungswe.se; 200 to 267 Te.le Layer containing an organic photoconductor, given- chlorinated paraffin per 100 parts of photoconductor randomly a binding agent and a chlorinated paraffin can be added. holds, which to With the use of such large amounts of the avoidance of the deterioration or the destruction of their property on the basis of chlorinated paraffin (more than 50 Gew.chtste.le) w.rd electrical charging or exposure Removing the electrophotographic recording material is directed. adversely affected (see. Example 5 below). So far, organic photosensitive media have been used. Accordingly, it is an object of the present invention materials for use in electrophotography 45 developed an electrophotographic recording material, which consists essentially of a poly with a photoconductive layer to provide meren organic photoconductors, such as. B. which always a predetermined task without Ver-Poly-N-vinylcarbazole, charge-transfer -olekülkom- deterioration of their properties due to plexes, such as poly-N-vinylcarbazole, charge-transfer-Mole- fatigue, caused by repeated use külkomplexePoly-N-vinylcarbazole-tetracyanoquinone- 50 in an electrophotographic copying process dimethane, poly-N-vinylcarbazole derivatives, such as nitration as a toner or a charge transfer copying, and tes poly-N-vinylcarbazole, polyvinylanthracene and if they are as photosensitive material for a polyacenaphthylene; or from a monomeric or photosensitive paper is used, meet ganic photoconductors, such as anthracene, pyraizoline, can.
Oxazole, triazole, hydrazone, etc. 55 Another object of the invention is to provide an electro- This kind of organic photographic photosensitive material to be provided has many advantages over any other, which does not deteriorate in properties organic photosensitive material, which in due to fatigue and without decrease in consists essentially of selenium or zinc oxide, etc., image density can be used. with a view to sensitization, transparency, 60 These objects are achieved according to the invention by em good film formation, high flexibility, the low ge electrophotographic recording material with weight and the low manufacturing cost. Thus a photoconductive layer that has an organic There is growing interest in its practical photoconductor, optionally a binder and a Applications. contains chlorinated paraffin, dissolved, which However, there are serious disadvantages in that it is characterized in that the photoconductive layer 20 to by that the photosensitive materials, 50 parts by weight of a chlorinated paraffin with a which essentially consists of the above-mentioned chlorine content of 40 to 65 percent by weight per 100 organic compounds Photoconductors consist of Gi and the important part contains photoconductors.