Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/02—Charge-receiving layers
  • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
  • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
  • G03G5/0622—Heterocyclic compounds
  • G03G5/0624—Heterocyclic compounds containing one hetero ring
  • G03G5/0627—Heterocyclic compounds containing one hetero ring being five-membered
  • G03G5/0629—Heterocyclic compounds containing one hetero ring being five-membered containing one hetero atom

Definitions

• the invention relates to an electrophotographic recording material consisting of an electrically conductive carrier material and a photoconductive double layer made of organic materials, as well as a method for producing these electrophotographic recording materials and their use for reprographic purposes.
• the surface of an electrophotographic element which contains a photo-semiconducting layer, is first charged uniformly electrostatically for the purpose of image formation.
• the photo-semiconductor induction radiation the photo-semiconductor layer becomes electrically conductive on the irradiated surfaces, as a result of which the electrostatic surface charge flows off at these points if the electrically conductive carrier material is grounded.
• the unexposed areas retain their surface charge, so that a charge image corresponding to the original remains after the exposure.
• this charge image is treated with fine pigment pigment particles which have previously been charged in the opposite way to the surface charge of the electrophotographic element, these color pigment particles are deposited in the unexposed areas of the electrophotographic element and thus develop the invisible charge image into a visible image of the original.
• the image created in this way is then transferred to another surface, for example on paper, and fixed on it.
• the electrophotographic element can either be composed of a homogeneous layer of a photo semiconductor on an electrically conductive carrier material or of several layers arranged one above the other on the carrier.
• Electrophotographic recording materials with a multi-layer, so-called composite structure are described.
• DE-OS 2 220 408 discloses such materials comprising a conductive carrier, a first layer which contains charge carrier-producing compounds and a second layer with charge carrier transporting substances which is arranged in addition.
• Another group of charge-generating photoconductive organic materials is dispersed in the form of pigment particles in a matrix binder and applied to a support in a layer which contains the individual photoconductive particles.
• These are the electrophotographic elements described in the literature, which contain monoazo, disazo and squaric acid dye derivatives as coloring materials (e.g. US Pat. No. 3,775,105, US Pat. No. 3,824,099, US Pat. No. 3,898,084).
• the object of the invention was therefore to create extremely light-sensitive electrophotographic layers by means of organic photo semiconductors, which can be produced as simply as possible from a dye dispersion.
• the electrophotographic element should continue to be flexible, elastic and abrasion-resistant, the surface of which, if possible, should be smooth and free of striations without aftertreatment.
• the invention accordingly relates to dyes which are active in the first layer of the electrophotographic recording material as components which generate charge carriers.
• Dyes of the general formula I are suitable for this in the R 1 to R 4 are hydrogen, halogen, methyl and / or phenylthio, one or two of the radicals R 1 to R 4 C 2 to C 6 alkyl, cyclohexyl, phenyl, 2-naphthyl, hydroxy, C 1 to C 6 alkoxy allyloxy, phenoxy, methylthio, benzylthio, C 1 to C 4- alkylsulfonyl, phenoxysulfonyl, trimethylsilyl, trifluoromethyl, cyano, nitro, amino, N, N ⁇ C 1 - to C 4 -dialkylamino, a radical of the formula a radical of the formula NH ⁇ CO ⁇ R 5 , where R 5 is C 1 -C 6 -
• R 7 and R 8 which may be the same or different, represent C 1 -C 4 -alkyl, cyclohexyl or phenyl or R 7 and R 8 together represent a tetramethylene group, an aromatic heterocyclic or heterocyclically saturated 5- or 6- Ring mean and X, Y and Z have the meaning given above, and compounds of the formulas III, IV and V in which X, Y and Z have the meaning given above.
• R 9 and R 10 which may be the same or different, cyano, nitro, 4-halopheny), 4-cyanophenyl, 4-nitrophenyl, C 1 - to C 8 -alkoxycarbonyl, phenoxycarbonyl, a radical of the formula ⁇ CONH ⁇ R 11 , in which R 11 represents hydrogen, C 1 - to Cg-alkyl or a phenyl optionally substituted by phenoxy, cyano, nitro or CF 3 , up to three halogen, C 1 - to C 4 -alkyl or the rest of one heterocyclic amine; Sulfamoyl; Phenylsulfonyl with up to three halogens and / or C 1 - to C 4 -alkyl in the phenyl nucleus; a remainder of the formula in the A for R represents hydrogen or C 1 - to C 4 -alkyl and R 12 and R 13 represent hydrogen or hal
• R 14 and R 15 which may be the same or different, cyano, methylcarbonyl, phenylcarbonyl, 4-nitrophenyl, 4-cyanophenyl, C 1 - to C 6 -alkoxycarbonyl, phenoxycarbonyl, phenylsulfonyl, a radical of the formula in which A, R 12 and R 13 have the meaning given above.
• R 16 and R 17 which may be the same or different, cyano, 4-nitrophenyl, 4-cyanophenyl, C 1 - to C 4 -alkoxycarbonyl, phenylsulfonyl, a radical of the formula in which R 12 and R 13 are hydrogen or halogen, C 1 - to C 4 -alkyl or C 1 - to C 4 -alkoxy and R 19 is hydrogen or C 1 - to C 4 -alkyl; 1H-naphth-2,3-d-imidazolyl, pyridyl, 4-thiazolyl, 2-methyl-4-thiazolyl, 2-phenyl-1,3,4-thiadiazolyl- (5), 2-quinolinyl, 3-indolyl or 3-Benzthiazolyl mean.
• R 9 has the meaning given above and R 6 represents the residue of an aromatic or heterocyclic amine or hydrazine.
• R 18 phenyl, p-tolyl, 2- or 4-anisidyl, 2-or 4-chlorophenyl, 4-carbethoxyphenyl, 2-oxazolyl, 2-thiazolyl, 2-imidazolyl , 2- (4-phenylthiazolyl), 2- (4-methyl-5-carboethoxythiazolyl), 2-benzthiazolyl, 2- (6-ethoxybenzthiazolyl), 2-benzimidazolyl, 2- (1-methylbenzimidazolyl), 2- (5- Phenyl-1,3,4-thiadiazolyl) or 3-indazolyl mean.
• the first charge carrier-producing layer is applied to the electrically conductive layer carrier in the form of a dispersion.
• the dispersion for the first layer is produced by rolling together about 20 to 85 percent by weight of the solids content of the dispersion in one or more of the dyes suitable according to the invention and 80 to 15 percent by weight in a binder which is customary for this purpose and which may have barrier properties, in the form of a Solution in an organic, easily evaporable solvent.
• the first layer is cast in a thickness of approximately 0.005 to 5 ⁇ m, preferably 0.05 to 2.0 ⁇ m, which is to be understood as the solid layer thickness.
• An adhesive layer with a thickness of about 0.05 to 5 ⁇ m, preferably 0.1 to 0.8 ⁇ m, can be arranged between the carrier and the first layer.
• the transparent second layer is also arranged over the first layer by casting from a solution.
• the thickness of the second is preferably between 2 and 40 microns. It consists of 30 to 60 percent by weight of one or more charge-transporting compounds, 65 to 35 percent by weight of one or more binders customary for this, 0.1 to 4 percent by weight of additives that improve the mechanical properties and optionally up to 5 percent by weight of sensitizing or activating agents Connections together.
• the casting process is carried out from a low-boiling solvent.
• barrier layer of about 0.05 to 1.5 ⁇ m between the first and second layers. preferably 0.1 to 0.5 ⁇ m, while it may be appropriate, depending on the intended use of the electrophotographic recording material, to apply an inactive layer which acts as a cover and protective layer to the charge transport layer.
• Aluminum foils, aluminum foils, nickel foils or plastic foils coated with aluminum, tin, lead, bismuth or similar metals, preferably polyester foils, are suitable as the electrically conductive carrier material. The choice is determined by the area of application of the electrophotographic element.
• the barrier layers between the conductive carrier material and the first layer or between the same and the second layer usually consist of metal oxide layers, e.g. B. alumina layers, polymers such. B. polyamide, polyvinyl alcohol, polyacrylates, polystyrene or similar systems. If necessary, the binder of the first layer can also serve as a barrier layer material at the same time.
• Polyacrylates, polymethacrylates, polyesters, polyphthalic esters, polyvinyl chlorides, styrene-maleic acid copolymers, epoxides and other generally customary resins are suitable as binders for the absorption of the dyes according to the invention for producing the charge-generating layer of the electrophotographic recording materials according to the invention.
• poly (N-vinylcarbazole) is particularly suitable.
• the electrophotographic recording materials according to the invention can also contain further constituents to improve their mechanical properties. So wetting agents like silicone oils can improve the surface quality.
• Sensitizers or activators of the upper second layer can also be incorporated.
• sensitizers which can be solved in disperse form, are, for. B. triphenylmethane dyes, xanthone dyes, soluble perylene derivatives such as perylene tetracarboxylic acid esters and a number of other compounds are known.
• Compounds with high electron affinity e.g. B. nitro compounds such as 2,4,7-trinitrofluorenone-9.
• the electrophotographic recording material according to the invention contains highly light-sensitive photoconductive double layers which have a high mechanical stability and can, for example, be arranged on a cylindrical drum or circulate as an endless belt without the occurrence of signs of wear. Accordingly, they are very suitable for use for reprographic purposes, e.g. B. as copy layers, electrophotographic offset printing plates.
• dyes 1 to 17 are mixed with 3 g of a copolymer of vinyl chloride, acrylic acid and a maleic diester and 25 g of tetrahydrofuran and rolled on a roller mill for 12 hours. Then 75 g of tetrahydrofuran and 25 g of toluene are added. The mixture is homogenized on the roller mill for one hour.
• This dispersion is then applied with a squeegee to an untreated aluminum carrier sheet of 175 ILm thickness.
• the casting gap is 60 [ lm.
• the doctor blade is pulled off at a speed of 260 mm / min. After flashing off and drying for 30 minutes at 90 ° C., a dry layer thickness of 0.75 to 0.8 ⁇ m remains.
• a solution of 47.75 g of poly (N-vinylcarbazole), 5.2 g of phthalic acid dihexyl ester and 5.75 g of a polycarbonate with a melting temperature of 220 to 230 ° C. in a solvent mixture of 287.5 is in each case on this first, covering layer g of tetrahydrofuran and 74.25 g of toluene.
• the casting gap is 140 p.m each; the doctor blade is pulled off at 260 mm / min. After ventilation and drying for 30 minutes at 90 ° C, a dry layer of 8 to 8.5 ⁇ m thick remains.
• the electrophotographic element thus prepared is then loaded with a high voltage of -740 kV on a corona wire at a distance of 10 mm above the layer surface. After 20 seconds of loading, the maximum surface potential in volts is determined. These surface potentials are based on the surface potential of a completely similarly produced plate, equal to 100%, which, according to DE-OS 2 237 539 N, contains N'-dimethy! Peryien-3,4,9,10-tetracarbonate diimide. After another 20 seconds in the dark, the percentage potential drop, based on the maximum potential. Then the electrophotographic element is irradiated with the light of a xenon lamp with a power consumption of 150 watts. The light-induced percentage potential drop, based on the potential after the dark drop, is measured.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Photoreceptors In Electrophotography (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=6127837

Family Applications (1)

Country Status (5)

Families Citing this family (10)

Family Cites Families (17)

• 1981
  • 1981-03-20 DE DE19813110953 patent/DE3110953A1/de not_active Withdrawn
• 1982
  • 1982-03-12 EP EP82102008A patent/EP0061094B1/de not_active Expired
  • 1982-03-12 DE DE8282102008T patent/DE3266612D1/de not_active Expired
  • 1982-03-19 JP JP57043024A patent/JPS57181552A/ja active Granted
  • 1982-03-19 DK DK123882A patent/DK162126C/da not_active IP Right Cessation
• 1983
  • 1983-11-22 US US06/554,435 patent/US4481272A/en not_active Expired - Lifetime

Also Published As

Similar Documents

Legal Events