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, 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
• • 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, 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
  • G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
  • G03G5/0528—Macromolecular bonding materials
  • G03G5/0532—Macromolecular bonding materials obtained by reactions only involving carbon-to-carbon unsatured bonds
  • G03G5/0539—Halogenated polymers
• • 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, 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
  • G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
  • G03G5/0528—Macromolecular bonding materials
  • G03G5/0557—Macromolecular bonding materials obtained otherwise than by reactions only involving carbon-to-carbon unsatured bonds
  • G03G5/0567—Other polycondensates comprising oxygen atoms in the main chain; Phenol resins
• • 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, 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
  • G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
  • G03G5/0528—Macromolecular bonding materials
  • G03G5/0557—Macromolecular bonding materials obtained otherwise than by reactions only involving carbon-to-carbon unsatured bonds
  • G03G5/0582—Polycondensates comprising sulfur atoms in the main chain
• • 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, 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
  • G03G5/0644—Heterocyclic compounds containing two or more hetero rings
  • G03G5/0661—Heterocyclic compounds containing two or more hetero rings in different ring systems, each system containing at least one hetero ring

Definitions

• ABSTRACT Recording process comprising exposing to imagewise modulated electromagnetic radiation a photoconductive insulating recording element comprising an organic photoconductive compound corresponding to one of the following general formulae:
• each of Z and Z represents the necessary atoms to close an adjacent ring or ring system including such ring or ring system in substituted form
• Ar represents a bivalent aromatic group
• each of R and R represents hydrogen, an aliphatic group including a cycloaliphatic group or said groups in substituted form, or an aryl group,
• R and R together represent the necessary atoms to close a nitrogen-containing ring including such a ring in substituted state.
• A represents an alkylene group or an alkylene chain interrupted by a phenylene group
• Ar represents a bivalent aromatic group.
• No Drawings ELECTROPHOTOGRAPHIC RECO Ar represents a bivalent aromatic group e.g. a pheny- MATERIAL WITH A PHOTOCONDUCTIVE lane group,'and
• CARBAZOL CO each of R, and R (the same or different) represents hy-
• This invention relates to recording and reproduction drogen, an aliphatic group including a cycloaliphatic of information-wise modulated electromagnetic radia- 5 group or said groups in substituted form, e.g. an alkyl tion and to recording materials suitable therefor, and group including asubstituted alkyl group e.g. methyl or particularly relates to such processes and recording benzyl, or an aryl group e.g. phenyl, or R and R tomaterials containing one or more organic photocongether represent the necessary atoms to close a nitroductive compounds as hereinafter described.
• Preferred compounds according to the present invenby using in its compositionaphotosensitive compound tion that are particularly suited for use in electrocorresponding to the following general formula! graphic recording materials are those wherein the atoms represented by 2 and Z form a carbazole nu- & I I cleus having on the nitrogen atom of the carbazole ring ⁇ L I N t a phenyl group that is substituted in the p-position with I the Ar l R 1 R1 2 wherein each of Z and Z (the same or different) represents the group as defined.
• a mixture of 39 g of N-(p-nitrobenzene)-carbazole and 3 ml of Raney nickel was brought to a volume of 240 ml with ethylene glycol monomethyl ether. Hydrogenation was performed at 1500 psi and 80C. After 12 hours of shaking about 98% of the hydrogen had entered into reaction. The Raney nickel was filtered off, the solvent was evaporated and the residue was an oily product that slowly solidified.
• the photoconductive compounds applied according to the present invention may be used alone or in combination with substances imparting desired chemical or physical properties to the recording element. So, these substances can be combined with other substances that either or not are photoconductive and exert an influence e.g. on the dark resistivity, the dischargeability or conductivity of the recording layer by an exposure to electromagnetic radiation, or on the transparency or the quality of the final image, e.g. by counteracting the fringe effect as described in the United Kingdom Patent Specification 1,007,349 filed December 12, 1961.
• the recording elements according to the present invention preferably contain at least 5 by weight of a photoconductive compound being within the scope of the above general formula.
• the recording element preferably consists for at least 10 72 by weight of one or more of the said compounds.
• the electrically insulating binding agent used in a recording layer containing said photoconductive compound(s) may provide the desired mechanical strength e.g. to form a selfsupporting layer, and preferably has a resistivity of at least 10 ohm. cm.
• the recording layer consists of the photoconductor, which, e.g., has been applied to a suitable support in molten state forming a micro-crystalline or glass-like layer on cooling.
• This technique can be applied when the photoconductive recording element has not topossess a high mechanical strength.
• reference is made to the Canadian Patent Specification 712,541 filed Feb. 5, 1960 by Gevaert Photo-Producten N.V.
• Macromolecular compounds suitable for use as insu- are Macromolecular compounds suitable for use as insu-,
• lating binding agent for the photo-conductive compounds are, e.g., natural resins such as dammar resin, gum arabic, microcrystalline waxes,.modified natural substances such as cellulose diacetate, cellulose triacetate, and ethylcellulose, pentaerythrite polyesters or modified colophony resins and ester gums, polymers such as polyethylene, polystyrene and copolymers of styrene, polyvinyl acetate and copolymers of vinyl acetate, polyvinyl acetals of formaldehyde, acetaldehyede or butyraldehyde, polyacrylic acid esters and polymethacrylic acid esters, coumarine-indene resins,
• natural resins such as dammar resin, gum arabic, microcrystalline waxes,.modified natural substances such as cellulose diacetate, cellulose triacetate, and ethylcellulose, pentaerythrite polyesters or modified colophony resins and este
• epoxy resins and polycondensates such as glycerol phthalate resins and other glyceryl polyesters, alkyd resins, diethylene glycol polyesters, formaldehyde resins and silicone resins.
• Preferred binding agents are halogen-containing polymers.
• the sensitization of organic photoconductors with halogen-containing polymers is described in the United Kingdom Patent Specification 964,878 filed May 3, l960 by Gevaert Photo-Producten N.V. Ac-
• a material suitable for use in electrophotography comprises a photoconductive layer incorporating an organic monomeric photoconductor and a halogen-containing polymer in such layer or in a juxtaposed layer (if any), the sensitivity of said photoconductor having been increased by making it to interact with said halogen containing polymer by heatmg.
• semi-transparent recording layers are prepared, in which said photoconductive compounds are used in admixture with (an) inorganic photoconductive substance(s), especially photoconductive substances of the group of zinc oxide, photoconductive lead(ll) oxide and photoconductive cadmium sulphide or cadmium selenide.
• an inorganic photoconductive substance(s) especially photoconductive substances of the group of zinc oxide, photoconductive lead(ll) oxide and photoconductive cadmium sulphide or cadmium selenide.
• Suitable spectral sensitizing dyestuffs for the organic photoconductor are among others organic dyestuffs, known as methine dyes, or xanthene dyes of which the phthaleins and rhodamines are subclasses, and triarylmethane dyes e.g. crystal violet (C.I. 42,555) and the triarylmethane dyes described in published Dutch Patent Application 6704706 filed Apr. 3, 1967 by Gevaert-Agfa N.V.
• methine dyes includes monoas well as polymethine dyes which dyes are known to those skilled in the art of the spectral sensitization of light-sensitive silver halide.
• Preferred methine dyes are of the cationic type.
• Rhodamine B Rhodamine B
• Rose Bengale C.l. 45,440
• Fluorescein C.I. 45,350
• the spectral sensitizing dyes are preferably added to the recording layer composition in a proportion of 0.01 to by weight in respect of the photoconductive substance(s).
• methine dyes are within the scope of the following general formulae:
• A stands for a dimethine or tetramethine group including a substituted dimethine or tetramethine group
• n 1 or 2
• R stands for alkyl including substituted alkyl, an unsaturated aliphatic group e.g. allyl, aralkyl including substituted aralkyl, aryl including substituted aryl or cycloalkyl,
• R stands for alkyl, aryl including substituted aryl, e.g. phenyl and phenyl substituted preferably in the pposition by alkyl, halogen and alkoxy, a 5- or 6- membered heterocycle the heteroatom of which is oxygen, sulphur, selenium or nitrogen such as 2-, 3-, or 4- pyridyl, 2-furyl, Z-thienyl, etc. including their quaternary salts,
• R stands for hydrogen or has one of the meanings given for R,
• R stands for hydrogen, alkyl, alkoxy or halogen or together with R forms an alkylene bridge such as dimethylene and trimethylene,
• each of R and R stands for hydrogen, alkyl, alkoxy or halogen or together represent,
• X represents an anion e.g. Cl, Br, I, C10 CH3SO4, 0r
• R group contains already an anion (betaine type salt), and Z represents the atoms necessary, to complete a heterocyclic nucleus of the types used in the production of cyanine dyes e.g. such 13 (p-toly)-thiazole, 4-(p-bromophenyl)-thiazole, 4,5- dimethylthiazole, 4,5-diphenylthiazole, 4-(2-thienyl)- thiazole, 4-(m-nitrophenyl)-thiazole, those of the benzothiazole series, e.g.
• benzothiazole 4- chlorobenzothiazole, S-chlorobenzothiazole, 6- chlorobenzothiazole, 7-chlorobenzothiazole, 4- methylbenzothiazole, S-methylbenzothiazole, 6- methylbenzothiazole, S-bromobenzothiazole, 6- bromobenzothiazole, 6-sulphobenzothiazole, 4- phenylbenzothiazole, S-phenylbenzothiazole, 4- methoxybenzothiazole, S-methoxybenzothiazole, 6- methoxybenzothiazole, -iodobenzothiazole, 6- iodobenzothiazole, 4-ethoxybenzothiazole, 5-
• benzimidazole 5,6-dichlorobenzimidazole, 5- chlorobenzimidazole, 5,6dibromobenzimidazole, 5- chloro-6-amino-benzimidazole, 5-chloro-6- bromobenzimidazole, S-phenylbenzimidazole, 5- fluorobenzimidazole, 5,6-difluorobenzimidazole, 5- cyanobenzimidazole, 5,6-dlcyanobenzimidazole, 5- chloro-6-cyanobenzimidazole, 5-fluoro-6- cyanobenzimidazole, 5-acetylbenzimidazole, 5-chloro- 6-flu0robenzimidazole, S-carboxybenzimidazole, 7- carboxybenzimidazole, 5-carbethoxybenzimidazole, 7-carbethoxybenzimidazole, 5- sulphamylbenzimidazole, or S-N-ethylsulphamyl
• A stands for a monomethine or trimethine group including a substituted monomethine or trimethine group
• each of R' -R and R" -R" has one of the meanings given for R R X; has the same significance as X Ill.
• each of R, and R" (the same or different) has one of A the meanings given for R X has the same meaning as X A has the same meaning as A each of m and p (the same or different) stands for 1 or 2, and
• each of Z and Z stands for the atoms necessary to complete a heterocyclic nucleus of the thiazole, benzothiazole, naphthothiazole, thionaphtheno[7,6-d1-thiazole, thiadiazole, oxazole, benzoxazole, naphthoxazole, selenazole, benzoselenazole, naphthoselenazole, Z-quinoline, 4-quinoline, pyrimidine,
• the recording material contains one or more substances that increase the photoconductivity of the recording material in the inherent spectral sensitivity range of the said heterocyclic organic photoconductive compounds.
• a binding agent can act as a sensitizing agent that enhances the total sensitivity of the recording element.
• compounds which contain one or more electronattracting atoms or groups e.g. those that are known as non-ionic Lewis acids, e.g. the Lewis acids that can form a charge transfer complex as described in U.S. Pat. No. 3,408,183 of Joseph Mammino issued Oct. 29, 1968.
• the photoconductive compounds may be used in admixture with diazonium salts that on exposure to electromagnetic radiation produce (a) radical(s) that irreversibly increase(s) the electro-conductivity of a recording layer.
• diazonium salts that on exposure to electromagnetic radiation produce (a) radical(s) that irreversibly increase(s) the electro-conductivity of a recording layer.
• Such substances as well as details about their incorporation into a recording layer containing an organic photoconductive insulating substance are described in the United Kingdom Patent Specification 964,872 filed Apr. 22, 1959 by Gevaert Photo- Producten NV. and the U.S. Pat. No. 3,113,022 of Paul Maria Cassiers, Jean Marie Nys, Jozef Frans Willems and Rene Maurice Hart issued Dec. 3, 1963.
• a particularly suitable conductivity-increasing diazonium compound is p-nitrobenzenediazonium chloride.
• the diazonium compounds are preferably used in an amount of 0.01 to 10 by weight in
• additives well known in the art of preparing photoconductive coatings for recording purposes may be used, eg matting agents, fluorescing compounds, phosphors, optical brightening agents, agents controlling the adhesive power of the recording layer, agents controlling the elasticity, the plasticity and the hardness of the recording layer, agents controlling the viscosity of the coating composition, antioxidants, glossimproving agents, etc.
• Transparent and semi-transparent recording materials containing the photoconductive heterocyclic organic compounds are described hereinbefore are especially suited for use in recording materials applied for the production and reproduction of microfilm images.
• Microfilm images can be copied in contact or enlarged optically on recording materials according to the pres ent invention.
• the transparencies obtained can serve as negative or positive intermediate prints for further printing, e.g. on diazotype materials.
• the semitransparent recording materials according to the present invention preferably have an optical density not larger than 0.30 towards visible light or the copying light used in the printing apparatus wherein it is used as intermediate print.
• the photoconductive heterocyclic organic compounds described hereinbefore are further especially suited for use in the production of pigment images wherein the latter may have the properties of a fluorescent compound or phosphor.
• luminescent phosphors are used in screens of cathoderay tubes and more particularly in television, X-ray, radar and oscilloscope screens.
• a pattern of a phosphor on a screen support is produced by the steps of applying to said support a coating of an electroconductive material and to said coating a layer comprising a vaporisable or thermolysable photoconductive compound optionally incorporated in a vaporisable or thermolysable binding agent.
• an electrostatic charge pattern corresponding with the pigment pattern to be produced is formed in an electrophotopgrahic way, and the electrostatic charge pattern is developed with non-volatile powder particles that have the desired phosphorescent or luminescent properties.
• the photoconductive layer containing the phosphor powder image is heated to remove the volatile substances of the photoconductive recording layer and to make the phosphor pattern adhere to the screen support.
• thermolysable binding agent In order to fix the powder image before applying the heating step it is preferably overcoated with a layer of a thermolysable binding agent.
• the recording layer may further contain boric acid.
• thermolysable binding agents belong to the class of the polyacrylic acid esters and polymethacrylic acid esters, e.g. polymethyl methacrylate, polyethyl methacrylate and polyethyl acrylate.
• the thickness of the photoconductive layers of the present invention is not critical but is open to choice within a wide range according to requirements in each individual case. Good results are attained with photoconductive layers of a thickness between 1 and 30 p. preferably between 2 and 20 t. Too thin layers do not have a sufficient insulation power in the absence of active electromagnetic radiation, whereas too thick layers require extensive exposure times.
• a relatively conductive support for the recording layer is used, e.g. an electroconductive sheet or plate, or an insulating sheet or plate covered with an electroconductive interlayer.
• BY electro-conductive plate or sheet is understood a plate or sheet whose electrical resistivity is smaller than that of the non-irradiated (darkadapted) photoconductive layer i.e. in general smaller than ohm.cm and preferably is at least 100 times as small as that of the recording layer. Supports whose resistivity is not higher than 10 ohm.cm are preferred.
• the recording layers themselves preferably have an electrical insulating power as high as possible without affecting too much the photosensitivity by means of too high an amount of insulating binding agent.
• the recording layers In nonirradiated state (dark-adapted state) the recording layers preferably have a resistivity of at least 10 ohm. cm.
• Suitable conductive plates are, e.g. plates of metals such as aluminium, zinc, copper, tin, iron, or lead.
• Suitable electro-conductive interlayers for insulating supports are, e.g. vacuum-coated metal and conductive metal compound (metal oxide or metal salt) layers such as silver, tin, aluminum, and copper iodide conductive layers, transparent conductive polymer layers, e.g. applied from polymers containing quaternized nitrogen atoms, such as those described in the United Kingdom Patent Specification 950,960 filed Sept. 23, 1960 by Gevaert Photo-Producten N.V., or layers containing conductive particles, e.g. carbon black and metal particles dispersed in a binder.
• the binder used for said particles has a resistivity preferably lower than 10 ohm.cm.
• a suitable binder for that purpose is gelatin.
• resin sheets having an optical density of not more than 0.10 are preferred, e.g. a sheet made of polyethylene terephthalate or cellulose triacetate.
• the conductive interlayer preferably consists of a metal coating, e.g., a vacuum-coated aluminium layer having an optical density of not more than 0.30, or of a conductive transparent polymer layer composed, e.g. 'of an organic polyionic polymer, e.g. a polymer containing quaternized nitrogen atoms such as a quaternized polyethylene-imine.
• a paper sheet is used as support for the recording layer.
• Paper sheets that have an insufficient electrical conductivity are coated or impregnated with substances enhancing their conductivity, e.g. by means of a conductive overcoat such as a metal sheet laminated thereto.
• hydroscopic com pounds and antistatic agents as described, e.g. in the United Kingdom Patent Specification 964,877 filed May 2, 1960 by Gevaert Photo-Producten N.V., and antistatic agents of polyionic type, e.g. CALGON CONDUCTIVE POLYMER 261 (trade mark of Calgon Corporation, Inc. Pittsburgh, Pa., U.S.A.) for a solution containing 39.1% by weight of active conductive solids, which contain a conductive polymer having recurring units of the following type:
• Paper sheets are preferably impermeabilized to organic solvents, e.g. by means of a water-soluble colloid or by strongly hydrating the cellulose fibers such as in the case of glassine paper.
• the photoconductive substances involved preferably are first dissolved or dispersed in a suitable organic solvent such as a chlorinated hydrocarbon, e.g. methylene chloride.
• a suitable organic solvent such as a chlorinated hydrocarbon, e.g. methylene chloride.
• the solution or dispersion thus obtained is spread uniformly on a surface of a suitable support, e.g. by centrifuging, spraying, brushing, or coating. Thereupon the layer formed is dried in such a way that a solid photo conductive layers is formed on the surface of the support.
• Recording materials according to the present invention can be used in any of the different techniques known in recording with the aid of photoconductors. According to a preferred embodiment they are used in a technique based on the discharge of an electrostatically charged recording layer by exposure to light.
• Photoconductive recording materials prepared according to the present invention can be used in exposure units equipped with incandescent lamps, so that they need not be exposed to light rays rich in ultraviolet such as those emitted by a high-pressure mercury vapour bulb.
• the electrostatic charging of photoconductive recording elements according to the present invention can be effected according to any method known in electrophotography, e.g. by friction with a smooth material, with a material possessing a high electric resistance, e.g. a cylinder coated with polystyrene, by corona discharge, by contact charge, or by discharge of a capacitor.
• Recording materials containing the said organic photoconductive substances can be used in a recording technique comprising a negative corona charging as well as in a recording technique comprising a positive corona charging.
• the electrostatic latent image can be converted into a visible image either on the electrophotographic material wherein the latent image was formed, or on a material to which the electrostatic latent image was transferred, e.g. by application of the method described in the Belgian Patent Specification 529,234 filed May 29, 1954 by Chester Floyd Carlson.
• the conversion of the original or transferred latent image into a visible image can occur according to one of the techniques known in electrophotography, wherein use is made of a conductivity pattern (e.g. electrolysis) or the electrostatic attraction or repulsion of finely divided coloured substances, which, e.g. are present in a powder mixture, in an electrically insulating liquid (e.g. in the form of a suspension) or in a gas (e.g. in the form of an aerosol), or wherein electrostatic attraction is used for selectively wetting charged portions of the recording layer, as described in the United Kingdom Patent Specifications 1,020,505 filed Nov. 8, 1961 and 1,033,419 filed Nov. 26, 1962 both by Gevaert Photo-Production N.V.
• a conductivity pattern e.g. electrolysis
• electrostatic attraction or repulsion of finely divided coloured substances which, e.g. are present in a powder mixture, in an electrically insulating liquid (e.g. in the form of a suspension) or in a
• a negative or a positive print can be obtained from any original. If both printing material and developing powder or developing liquid have the same sign of charge, the powder only adheres to the discharged areas so that a negative print is obtained. If the signs of the recording material and of the developing powder or developing liquid differ, a positive print is obtained.
• the visible image obtained can, if necessary, be fixed according to one of the methods known in electrophotography, e.g. by heating, or it can be transferred to another support, e.g. according to the method described in the United Kingdom Patent Specification 658,699 filed Apr. 14,1949 by Battelle Memorial Institute and fixed thereon.
• the present heterocyclic organic photoconductive compounds can also be supplied in a thermoplastic recording process to form a ripple-image as described, e.g. in the United Kingdom Patent Specification 964,881 filed May 17, 1960 by Gevaert Photo- Producten N.V.
• the present invention is by no means limited to one or other particular embodiment of using the electrophotographic material containing the photoconductive compounds as described herein.
• the exposure technique, the charging method, the formation of the charge pattern, the transfer of such pattern if applied, the developing method, and the fixation or the transfer of the developing material pattern may be modified or adapted.
• composition of the recording materials used in these methods may be adapted to the requirements of the recording process used.
• Electrophotographic materials according to the present invention can be employed in reproduction techniques, wherein different kinds of electromagnetic radiations are used, e.g. visible light, U.V.-radiation, X- rays and y-rays.
• the latent wedge image obtained was electrophoretically developed by means of an electrophoretic developer prepared by diluting the concentrated developer composition described hereinafter in a volume ratio of 15/1000 by means of ISOPAR H (an isoparaffinic hydrocarbon mixture having a boiling range of 177-188C sold by Esso Belgium N.V., Antwerp, Belgium):
• ISOPAR H (trade name) 750 ml resin solution prepared as described hereinafter 150 g.
• the resin binder solution was prepared by heating 500 g of ALKYDAL L 67 (a trade name of Konverkusen, W. Germany for a linseed oil-modified (67 by weight) alkyd resin) and 500 m1 of white spirit containing 1 1 by weight of aromatic compounds at 60C till a clear solution was obtained, and subsequent cooling.
• ALKYDAL L 67 a trade name of Konverkusen, W. Germany for a linseed oil-modified (67 by weight) alkyd resin
• the relative speed values of the developed materials were calculated based on a comparison of the number of non-toned (discharged) steps present in the wedge prints obtained with materials containing a photoconductor of Table 1 with the number of non-toned steps produced in a material containing photoconductor number 2 of Table Ii to which is given arbitrarily the speed value 100.
• the dried recording layer contained 2 g of photoconductor per sq.m.
• the coated samples were negatively charged with a negative corona having a potential difference of 6000 V between the corona wires and the ground.
• the charged recording layer was contact-exposed for 6 sec. through a step-wedge having 0.20 log exposure increments. in the exposure tungsten filament light was used.
• the latent wedge images were electrophortetically developed as described in Example 1.
• the relative speed values of the developed materials were compared with those of the electrophotographic material containing photoconductor number 6 of Table l which is given arbitrarily the speed value 100.
• the dried recording layer containing approximately 3 g of photoconductor per sq.m was charged with a negative corona and contact-exposed with 500 lux.sec with the same light source as in Example 2.
• the latent image was electrophoretically developed for 5 sec with the developer described in Example 1. A good copy of the original was obtained.
• the latent image was developed for 5 sec with a triboelectrically charged positive toner on the base of three parts by weight of pitch, 4 parts by weight of colophony and 3 parts by weight of carbon black.
• EXAMPLE 5 The effect on the speed of electrophotographic recording materials resulting from a few chemical sensitizers was examined.
• A represents an alkylene group or an alkylene chain inwherein: terrupted by a phenylene group, and each of Z, and Z (the same or different) represents the Ar r pr n s a phenylene group. necessary atoms to close a benzene nucleus, 5.
• a method as in claim 1 comprising the steps of Ar represents a phenylene group, producing an electrostatic charge pattern by electroeach of R and R (the same or different) represents hystatically charging and information-wise exposing to drogen, an alkyl group, a cycloalkyl group, or a benzyl electromagnetic radiation said recording element progroup. 2 ducing thereby an information wise increase of the con- 2.
• the rea period of time sufficiently long to produce thereon a cording element is a recording layer that has been apdeveloped electrostatic charge pattern, characterized li d to a conductive layer or support h i a resistivin that the recording layer stands in electroconductive 1 lower h h of h da kqldapted recording l relationship to a layer or support with lower resistivity ment and Contains an Organic Photoconductive compound 7.
• each of Z and Z represents the wherein necessary atoms to close a benzFne nucleus Z and Z have the same significance as in claim 2
• each of R1 and R2 represents A represents an alkylene group or an alkylene chain indrogen, an alkyl group, a cycloalkyl group, or a benzyl terrupted by a phenylene group
• group and Ar represents a phenylene group.
• Ar represents a phenylene group.

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• Spectroscopy & Molecular Physics (AREA)
• Photoreceptors In Electrophotography (AREA)
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• 1972
  • 1972-09-22 GB GB4401072A patent/GB1441105A/en not_active Expired
• 1973
  • 1973-09-10 BE BE1005348A patent/BE804636A/nl unknown
  • 1973-09-18 DE DE19732346803 patent/DE2346803A1/de active Pending
  • 1973-09-21 US US399503A patent/US3912509A/en not_active Expired - Lifetime
  • 1973-09-21 JP JP48106850A patent/JPS4971942A/ja active Pending

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