DE2038762A1 - Process for making electrophotographic sensitive material - Google Patents

Description

DR. E. WIEGAND DIPL.-ING. W. NIEMANN DR. M. KÖHLER DIPL-ING. C GERNHARDT

MÖNCHEN HAMBURG

4 Ana 107Π

TELEPHONE, 555476 8000 MUNICH 15, ^ '^ U

TELEGRAMS: KARPATENT NUSSBAUMSTRASSEIO

W. 400 11/70 - Ko / B

Fuji Photo Film Co. Ltd ·, Ashigara - Kamigun, Kanagawa / Japan

Process for the manufacture of electrophotographic sensitive material

The invention is concerned with a new electrophotographic method sensitive layer »When producing a print using the electrofax process an original of a color slide obtained using a silver halide photographic film it is required that the electrophotography sensitive Sohioht as a property a photosensitivity over the entire visible area and a graduated production capability for low contrasts possesses «The photo sensitivity that sioh over the entire visible area is generally covered by more than one type of sensitizing dye adsorbed on the photoconductive material · If zinc oxide is used as the photoconductive material, the graduated reproducibility obtained is generally of high contrast · Xm case of a silver halide film, the graduation is made by controlling the part size distribution of the used Silver halides. In an electrophotographic Method using a photoconductive material, however, it is difficult to obtain such a degree

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took to apply the adjustment regulation. If ·· auoh atfglloh, the era & ulevu & g by controlling the distribution of the quantity «adsorbed on the photoconductive element 3 sensitizing dye iu regulate, occurs tin Slope aur uniform adsorption due to τοη de- ■ orption and absorption of the sensitizing dye Im Course of the formation of the sensitive layer, which makes it difficult to achieve the desired result.

The object of the invention is therefore a production process for electrophotographic-sensitive material based on zinc oxide and insulating rarity with excellent grading capability. The object of the invention is a satisfactory process sur deposition tinee sensitive dye ·· ftst on the zinc oxide · borrowed. The Torttthenden objects of the invention are duroh int vorlligende HerstellungsTerfahren for tin eltktvopliotogrmpkiseh sensitive Ma * - • rial "rf Hilt, b @ li # M · 1η" lusllohe in vices and sur Ere ^ uguAg tos. 3ittiioa # & when dissolving in water, suitable lead finish and a "in« carboxyl group-containing aqueous dye are added to the solubilization, which was prepared by dispersing a finely divided photoconductive sink oxide * in water, whereby the dye is deposited on the surface of the sink oxide So that a colored zinc oxide powder is obtained, whereupon the powder mixed with water, then the colored powder, which if desired, can also be mixed with old unpolluted sink oxide powder, is ground with an insulating hair and this is obtained in the form of a eye

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tintr based bit of an electrolytic surface The above mentioned is presented colored · Zinc oxide powder has such properties If the dye is deposited on zinc oxide of sufficient strength, the separation of the deposited takes place Dye ·· or the readsorption on other things Zinc oxide extremely seldom, even if there is zinc oxide nit untreated a zinc oxide is yeraieoht · Therefore electrophotographically sensitive layers can be used ■ with a low contrast of the graduation replica

ability to produce by increasing the

colored zinc oxide powder bit untreated will·

The dye used in the context of the invention contains carboxyl groups and is very easy to absorb on zinc oxideDyes which contain sulfonyl groups are generally easy to deposit al · other «heavy metal ions. As compounds that provide lead ions, water-soluble string, for example, lead nitrate, and the like Bleiaoetat · · Terwendet be like

According to the invention, the hasset is used as a deposition of the dye ·· on the zinc oxide bit an aqueous Dispersion carried out · The · is achieved, but one Discharge that is sufficiently roasted in water contains dispersed sink oxide, is produced, and then this dispersion of the zinc oxide in an aqueous solution, which contains the dye solution and the lead ion,

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is admitted. As a result of this treatment, the dye in combination with the lead ion becomes insoluble and consequently firmly deposited on the surface of the zinc oxide. At this point, the water slurry can become hot. The resulting combination of dye and zinc oxide is then washed sufficiently with water. This washing treatment with water serves to remove water-soluble ions and is therefore important. In this washing treatment with water, no removal of the dye at all is observed in the process according to the invention. In general, dyes adsorbed on zinc oxide are prone to peeling off during washing. In the process according to the invention, however, U9X dye is deposited so firmly that in fact no removal of the dye takes place.

The colored, finely divided zinc oxide powder is then if necessary mixed with untreated zinc oxide and EU added to the insulating hair. By spreading it out of the mixture obtained in the form of a layer on an electrolytic base are electrophotographyoh sensitive materials received · The zinc oxide used for the purpose of the invention is generally after manufactured by the Freneh process and shows photoconductivity. The amount of the dye used in the context of the invention is in the range OyOOOI bis 2 parts by weight, based on 100 parts by weight of zinc oxide. Yes In the context of the invention, dyes that are in water not adsorbed on zinc oxide. Since · means that the inventively used Dyes only have to meet the requirement that they be coated on zinc oxide in the presence of lead ions.

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to be divorced.

Imifolgones are illustrative examples of dyes, which can be used according to the invention, given without the invention being limited thereto

Eosin Eriochroracyanin R (Color Index 43820), Chromasurol S (Color Index 43825), Alizarine Violet (Color Index 4545) "Phloxine (Color Index (Acid Red 98) 4540 $) Fluoresoin, chromium blue (Color Index 4333O) ₉ chrome Brilliant Violet (Color Index 43865), Brillantrotbeiae B a (Color index 45305), chrome yellow GG (color index 14025), chrome yellow H (color index 14095), stain blue 47 (color index 43 855) · Of all the dyes, 8ion showed that they are firmly deposited on zinc oxide and have Senelbiliaieraktirität · A sensitive sole bit good Graduation reproduction capability can be produced using the dyed zinc oxides according to the invention alone Duron application of the colored zinc oxides obtained in combination with untreated zinc oxide, sensitive soles with even better graduation reproduction values can be obtained with low contrast Case the colored zinc oxide becomes In a proportion tob | 0.1 to 5 parts by weight with 1 part by weight of untreated zinc oxide rermiseht.

The following examples serve for further information purification of the invention

Example 1

In a glass cup was 10 g of photoconductive zinc oxide (Product of Sakai Chemical Co., Ltd.)

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and stirred with 200 ml of distilled water. The mixture was subjected to an ultrasonic wave treatment at 29 kHz and a water dispersion of sufficiently distributed zinc oxide was obtained. 5 μl of a dilute aqueous solution of Eoein were added to this dispersion. Bas Eoein was not noticeably adsorbed on the zinc oxide from the aqueous solution. 5 ml of a dilute aqueous solution of lead acetate were then added, whereupon an abrupt adsorption of the Eoein on the zinc oxide was observed. When the zinc oxide was separated from the mother liquor on the centrifuge, the mother liquor was practically colorless and clear, which shows that the eosin had been completely adsorbed on the zinc oxide. Basically dark yellow zinc oxide was redispersed in 100 ml of distilled water. It was found that the sosin did not separate from the surface of the zinc oxide. The zinc oxide was again separated. When the dark yellow zinc oxide has been washed sufficiently with methanol _; no separation of eosin was observed in the washing liquid · The zinc oxide was dried and then combined with 2 g of a vinyl chloride-vinyl acetate copolymer and 13 g of butyl lactate and sufficiently ground in a small ball mill · The resulting paste of dark yellow color was spread on an aluminum plate » bit Trookenstärke of the layer was 6.5 ä bit wurdt layer dried and subsequently during 10 hours in a Bunkelraum at 40 ⁰ C allowed to stand. The sensitive layer obtained in this way assumed an electrical potential of 360 T btl through negative corona discharge. It was exposed to light through an optical cell and then with a liquid developer.

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agent containing a positively charged toner developed. The γ value indicating the γ was 1.1. Examination of the spectroscopic sensitivity showed that the sensitive layer was sensitized in the spectral range from 480 to 560 m × 1.

Example 2 Using 2.5 g of the dark yellow zinc λ

oxide according to Example 1 and 75 g of an untreated zinc oxide was carried out according to the procedure of Example 1 a sensitive layer made · of the graduation The indicative value γ of this layer was 0.7.

Example 3

The method according to Example 1 was used, jedooh Ohroaaeurol 8 (Mordant blue 29, color index 43825) used instead of van losin. Is became a zinc oxide powder Preserved in blue purple color · If a sensitive layer was made with this powder * that was the Layer practically through the entire visible area sensitized.

Example 4

His sensitive layer was made according to that Method prepared according to Example 1, but lead nitrate used instead of lead acetate »The layer gave practically the same results ·

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Claims (1)

20387G2 Claims Method for making an electrophotograph isoh sensitive eye, characterized in that one is soluble in water and releasable Lead ion when dissolving in water is a suitable lead compound and a water-soluble dye with carboxyl groups su a slurry is done, welohe duroh dispersion τοη finely divided * photoconductive zinc oxide was prepared in water, so that the dye is solidly deposited on the surface of the zinc oxide and a colored zinc oxide powder is obtained, the powder is washed with water, dissolving the colored one Powder, which can optionally be remaunched with untreated zinc oxide powder, with an insulating Resin is rermisoht and the Gemisoh obtained is spread in the form of a layer on a base with an electroconductive surface 2, method according to claim 1, characterized in that the dye used is sosin, brioohromoyanin R, chromazural S _9, alizarin triolet, phloxin, fluresoin, chroarein blue, chrome brilliant violet, mordant brilliant red B, chrome yellow 00, chrome yellow M or mordant blue 47 « 3 · Method according to claim 1 or 2, characterized in that the Blclvexft ^ ndung Blelaoetat or Lead nitrate is used * 4 · method according to claims 1 to 3 »characterized that the dye in an amount ranging from 0.0001 to 2 Qtw, parts, based on 100 parts by weight Zinc oxide, is used. 10984W1 530 5. Method according to claims t to A, because ₉ that "in" quantity dtr BltiYtrBunden la Bt * rtiöh tone 0.0005 bit 5 Stw, -Tiltn, bteoftn to 100 Giw, StUt zinc oxide »vtrwtndtt · 6 «EltrophotographltoA tapflndlioht Sehloht, htrgeettllt naoh dta Ttrfahrtn dtr Anaprüoht 1 to 5 BATH ORIGINAL t09844 / 1530