US3161505A - Material for electrophotographic purposes - Google Patents

Material for electrophotographic purposes Download PDF

Info

Publication number
US3161505A
US3161505A US162277A US16227761A US3161505A US 3161505 A US3161505 A US 3161505A US 162277 A US162277 A US 162277A US 16227761 A US16227761 A US 16227761A US 3161505 A US3161505 A US 3161505A
Authority
US
United States
Prior art keywords
parts
formula
thiodiazole
weight
resins
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US162277A
Other languages
English (en)
Inventor
Tomanek Martha
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Azoplate Corp
Original Assignee
Azoplate Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Azoplate Corp filed Critical Azoplate Corp
Application granted granted Critical
Publication of US3161505A publication Critical patent/US3161505A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07DHETEROCYCLIC COMPOUNDS
    • C07D285/00Heterocyclic compounds containing rings having nitrogen and sulfur atoms as the only ring hetero atoms, not provided for by groups C07D275/00 - C07D283/00
    • C07D285/01Five-membered rings
    • C07D285/02Thiadiazoles; Hydrogenated thiadiazoles
    • C07D285/04Thiadiazoles; Hydrogenated thiadiazoles not condensed with other rings
    • C07D285/121,3,4-Thiadiazoles; Hydrogenated 1,3,4-thiadiazoles
    • C07D285/1251,3,4-Thiadiazoles; Hydrogenated 1,3,4-thiadiazoles with oxygen, sulfur or nitrogen atoms, directly attached to ring carbon atoms, the nitrogen atoms not forming part of a nitro radical
    • C07D285/135Nitrogen atoms
    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G5/00Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
    • G03G5/02Charge-receiving layers
    • G03G5/04Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
    • G03G5/06Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
    • G03G5/0622Heterocyclic compounds
    • G03G5/0624Heterocyclic compounds containing one hetero ring
    • G03G5/0627Heterocyclic compounds containing one hetero ring being five-membered
    • G03G5/0633Heterocyclic compounds containing one hetero ring being five-membered containing three hetero atoms

Definitions

  • electrophotographic material consists of a support upon which there is a photoelectrically conductive insulator coating containing a photosemiconductor compound. This coatingis provided, in the dark, with an electrostatic charge and light is then shone imagewise on the material, either via the master or by the episcopic method, whereupon a latent electrostatic image that corresponds to the master is produced on the photoelectrically conductive coating.
  • This image is developed by being contacted for a brief time with a resin powder; a visible image is thus formed as a result of the adherence of the resin to the charged parts, The image is fixed by heating or by the action of solvent vapor so that the resin is securely anchored to the support.
  • photosemiconductor compounds inorganic substances such as selenium, sulfur or zinc oxide have been used. Also, organic substances such as anthracene, anthraquinone and benzidine have been employed for this purpose.
  • the present invention relates to a material for electrophotographic purposes consisting of a support and a photoelectrically conductive insulator coating, the latter consisting of or containing one or more thiodiazoles of the general formula R1 NN NJQJ km.
  • R and R are hydrogen or straight or branched chain saturated hydrocarbon groups which in the longest carbon chain contain up to 6 carbon atoms.
  • Exemplary alkyl groups are methyl, ethyl, propyl,
  • thiodiazoles of the present invention the following may, for example, be used:
  • the compounds in question are excellently suited for the production of photoelectrically conductive insulator layers and because of the improved homogenous nature of layers incorporating these compounds, they are an improvement over the layers hitherto known.
  • the compounds are, in general, colorless and have photosemiconductor properties of the most desirable type.
  • supports for the photoconductor layer foils made of metals such as aluminum, zinc and copper; cellulose products, such as paper and cellulose hydrate; cellulose esters, e.g., cellulose acetate and cellulose butyrate; or of plastics such as polyolefins, e.g., polyethylene and polypropylene; polyvinyl compounds, e.g., polystyrene, polyvinyl chloride and polyvinylidene chloride; polyacrylic compounds e.g., polyacrylonitrile and i polyrnethacrylate; polyesters, e.g., polyterephthalic acid glycol esters; polyamides and polyurethanes.
  • foils made of metals such as aluminum, zinc and copper
  • cellulose products such as paper and cellulose hydrate
  • cellulose esters e.g., cellulose acetate and cellulose butyrate
  • plastics such as polyolefins, e.g., polyethylene and polypropylene
  • paper is used as a supporting material, it is advisable for this 'to be pretreated to prevent the penetration of coating solutions, e.g., with a solution of methyl cellulose or polyvinyl alcohol inwater, or a solution of an interpolymer of acrylic acid. methyl ester with acrylonitrile in a mixture of acetone and methyl ethyl ketone, or solutions of polyamides in aqueous alcohols or with aqueous dispersions of such substances.
  • coating solutions e.g., with a solution of methyl cellulose or polyvinyl alcohol inwater, or a solution of an interpolymer of acrylic acid.
  • methyl ester with acrylonitrile in a mixture of acetone and methyl ethyl ketone or solutions of polyamides in aqueous alcohols or with aqueous dispersions of such substances.
  • foils with a laminated metal surface e.g., aluminum, are very suitable for 7 :these purposes.
  • the photoelectrically conductive thiodiazole compounds are advantageously dissolved in organic solvents such as benzene, acetone, methylene chloride, ethylene glycol monomethyl ether or mixtures of such solvents and the supporting material is coated therewith in the usual manner, e.g., by immersion, spraying, painting or roller application.
  • organic solvents such as benzene, acetone, methylene chloride, ethylene glycol monomethyl ether or mixtures of such solvents
  • the thiodiazoles it is often advantageous for the thiodiazoles to be used as the photoelectrically conductive coating in association with organic resins.
  • resins of this type balsam resin, colophony, shellac and synthetic resins suchas phenol resins modified with colophony and other resins with a high proportion of colophony, coumarone resins, indene resins and the substances covered by the collective term synthetic lacquer resins.
  • resins of this type balsam resin, colophony, shellac and synthetic resins suchas phenol resins modified with colophony and other resins with a high proportion of colophony, coumarone resins, indene resins and the substances covered by the collective term synthetic lacquer resins.
  • these synthetic lacquer resins include the following: processed natural substances such as cellulose ethers, polymers such as vinyl polymers, e.g., polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl acetals, polyvinyl ether, and polyacrylic and polymethacrylic esters, as well as polystyrene, isobutylene, chlorinated rubber, polycondensates, e.g., polyesters, such as phthalate resins, alkyd resins, maleinate resins, maleic acid/colophony mixed esters of higher alcohols, phenolformaldehyde resins, particularly colophony-rnodified phenol-formaldehyde condensates, urea-formaldehyde resins, melamine-formaldehyde condensates, aldehyde resins, ketone resins, xylene-formaldeh
  • processed natural substances such as
  • the proportion of resin to photoconductor substance can vary within wide limits. Mixtures in which the proportion of resin to photoelectrically conductive substance is between 2:1 and 1:2 are preferable. Particularly favorable results can be obtained by the use of mixtures in which the proportions are about equal.
  • the solutions of the thiodiazoles of the invention, with or without resins, are applied to the supporting material in the usual way, e.g., by painting, roller application or spraying. They are then dried, whereupon a uniform, homogeneous, transparent and usually colorless photoelectrically conductive coating is formed.
  • the light sensitivity of these photoconductor coatings is in the long wave ultra-violent region between about 3600 and 4200 A. With high pressure mercury vapor lamps, which emit a high proportion of ultra-violent radiation, good results can therefore be obtained with very short exposures.
  • the special sensitivity of the photoelectrically conductive coatings can be moved further into the visible region so that good results can be obtained with short exposures, even in the visible region. Even very small additions, e.g., somewhat less than 0.01%, produce good effects.
  • the quantity of Sensitizer added to the photoelectrically conductive layer generally, however, amounts to 0.0l-% by weight, preferably 0.1-3%. A larger quantity of sensitizer can be added, but in general does not bring any greater increase in sensitivity.
  • Such sensitizers, which in the main are dyestulfs, are disclosed for example in Belgian Patent No. 558,078.
  • the photoelectrically conductive insulator coating is charged, e.g., by a corona discharge from a charging device maintained at 6000-7000 volts.
  • the electrophotographic material is then exposed, either in contact with a master or by episcopic or diascopic projection of the master, whereupon an electrostatic image corresponding to the master is produced.
  • This invisible image is developed by being contacted with a developer consisting of a carrier and a toner.
  • the materials used may be fine glass balls, iron powder or fine plastic balls.
  • the toner consists of a mixture of a resin and carbon black or of a pigmented resin with an average grain size of about 1 to 100p.
  • the developer can also comprise a resin or pigment suspended in a dielectric liquid.
  • the image made.visible in this way is fixed, for example, by heatingwith an infra-red radiator to about 100170 C., preferably 120-7150" C., or by treatment with solvent vapor, e.g., trichloroethyle ne, carbon tetrachloride or ethyl alcohol, or with steam. In this way, images are obtained which correspond to the master and which have good contrast.
  • the electrophotographic images obtained in this manner can also be converted into printing plates if the supporting material, e.g., paper or metal, is wiped over with a solvent for the photoelectrically conductive layer, e.g., alcohol or acetic acid, then rinsed down with water and inked up in known manner with greasy ink. in this way, printing plates are obtained from which prints can be made in an offset machine.
  • a solvent for the photoelectrically conductive layer e.g., alcohol or acetic acid
  • the electrophotographic images can be used as masters for further copying on any type of light sensitive sheets.
  • the photoconductive compounds of the invention are superior in this respect also to the substances hitherto used, such as selenium and zinc oxide, since use of the latter results in cloudy coatings.
  • Images can be produced by the reflex process as well, if a translucent supporting material is used for the photoconductor coatings of the invention.
  • the present electrophotographic material has the advantage that it can be charged either positively or negatively so that positive images can be obtained with one and the same coating and the same developer, both from negative and from positive masters, by reversal of the polarity.
  • the coating is given a negative charge and is then exposed with a positive master, the use of a developer containing a positively charged toner will pro prise positive images.
  • the positively charged toner settles on the negatively charged parts not affected by the light.
  • positive copies can be prepared from negative masters, where the conditions are otherwise the same.
  • the positive toner is in this case repelled by the positively charged parts unaffected by the light and settles on the discharged parts that have been affected by the light.
  • the preparation of the photoelectrically conductive compounds of the invention consists of treatment of the corresponding p-alkylamino benzoic acid and 2 moles of thiosemicarbazide with polyphosphoric acid at C.
  • Polyphosphoric acid acts as a dehydrating agent which at the same time etfectsring closure;'the reaction takes about 2 hours.
  • the reaction mixture is then poured over ice and made alkaline (pH 89) with sodium-hydroxide.
  • the thiodiazole compounds then precipitate out, are filtered off, recrystallized and dried.
  • 2-(4-dimethylamino-phenyl)-5-aminothiodiazole 1,3,4,- corresponding to Formula 1 (melting point: 239-240 C.), is prepared from 37.4 parts by weight of 4 dirrlcthyl amino benzoic acid and 36.4 parts by weight of thioseudi carbazide, which are heated for two hours with 500'parts by volume of polyphosphoric acid at 120 C. After the mixture has cooled, it is poured over 5000 parts by weight of ice and made alkaline with 4000 parts by volume of 25% sodium hydroxide. Colorless crystals precipitate out which are recrystallized from ethyl alcohol.
  • 2-(4-diethylamino-phenyl)-5-amino-thiodiazole 1,3,4,- corresponding to Formula 2 (melting point: 224226 C.), is prepared from 38.6 parts by weight of 4-diethylamino benzoic acid and 36.4 parts by weight of thiosemicarbazide, which are heated for two hours with 500 parts by volume of polyphosphoric acid, working up as above. The yield is 5060%.
  • 2-(4 ethyl-11-propylamino-phenyl)-5-amino-thiodiazole- 1,3,4, corresponding to Formula 3 (melting point: 217- 218 C.), is prepared from 41.4 parts by weight of 4- ethyl-n-propylarnino benzoic acid and 36.4 parts by weight of thiosemicarbazide, which are heated for two hours with 5 00 parts by volume of polyphosphoric acid.
  • 2-(4-di-n-propylamino-phenyl)-5 amino thiodiazole 1,3,4, corresponding to Formula -4 (melting point: 228- 230" C.), is prepared from 44.2 parts by Weight of 4-di-npropylamino benzoic acid and 36.4 parts by weight of thiosemicarbazide, which are heated for two hours with I 500 parts by volumeof polyphosphoric acid. The yield. is 60-85%.
  • 2-(4-monoethylamino-phenyl) 5 amino thio'diazole- 1,3,4, corresponding to Formula 5 (melting point: 196 198" C.), is prepared from 33 parts by weight of 4-monoethylamino benzoic acid and 36.4 parts by Weight of thiosemicarbazide, which are heated for two hours with 500 parts by volume of polyphosphoric acid to 120 C.
  • 2-(4-1nono-n-propylamino-phenyl)-5 amino thiodiazole-1,3,4, corresponding to Formula 6 (melting point: 188-190 C.), is prepared from 35.8 parts by weight of 4-mono-n-propylamino benzoic acid and 36.4 parts by weight of thiosemicarbazide, which are heated for two hours to 120 C. in 5 parts by volume of polyphosphoric acid.
  • 2- (4-mono-isoamylamino-phenyl) -5-amino-thiodiazole- 1,3,4, corresponding to Formula 7 (melting point: 178- 179 C.), is prepared from 41.4 parts by weight of 4- mono-isoamylamino benzoic acid and 36.4 parts by weight of thiosemicarbazide, which are heated for two hours to 120 C., in 500 parts by volume of polyphosphoric acid. The yield is 80-90%
  • the invention will be further illustrated by reference to the following specific examples:
  • Example I 1 part by weight of 2-(4-diethylamino-phenyl)-5-aminothiodiazole-l,3,4 (corresponding to Formula 2) and 1.2 parts by weight of a polyindene resin with a softening temperature of 80 C., commercially available under the name Gebaganharz J/T80, are dissolved in 30 parts by weight of ethylene glycol monomethyl ether. To this solution, 0.002 part by weight of Crystal Violet in 0.5 part by volume of methanol is added. The solution is applied to paper, the surface of which has been treated to prevent the penetration of organic solvents, and dried. The paper thus coated is provided by means of a corona discharge, with a negative electric charge.
  • a positive master It is then exposed with a positive master to a high pressure mercury lamp and dusted over in known manner with a developer consisting of a mixture of a carrier and a toner.
  • a developer consisting of a mixture of a carrier and a toner.
  • the carrier glass balls, iron powder and other inorganic substances can be used.
  • the toner consists of a resin-carbon black mixture or pigmented resins of a grain size of between 1 and 100a. An image corresponding to the master is formed, which is fixed by slight heating; it has good contrast.
  • a transparent support e.g., a cellulose acetate foil or transparent paper
  • the image electrophotographically produced can be used as a master for further copying on light sensitive sheets.
  • Example 11 1 part by weight of 2-(4-ethyl-n-propylamino-phenyl)- S-amino-thiodiazole-1,3,4 (corresponding to Formula 3), 1.5 parts by weight of'a ketone resin with a softening temperature of 7682 Cxand an acid number of 0 (commercially available under the name Kunststoffharz AP) and 0.005 part by weight of Brilliant Green are dissolved in 20 parts by volume of ethylene glycol monomethyl ether and the solution is applied to a paper to which aluminum is laminated. After evaporation of the solvent, a coating remains which adheres firmly to the aluminum surface.
  • the paper After negative charging by means of a corona discharge, the paper is given a second exposure with a positive master to a 100 watt filament lamp at a distance of about 30 cm. Development is then accomplished with a developer as described in Example I and an image corresponding to themaster appears, which is fixed with trichloroethylene vapor.
  • Example III 2 parts by weight of 2-(4-mono-isoamyl-amino-phenyl)- S-amino-thiodiazole-l,3,4 (corresponding to Formula 7), 0.4 part by weight of 2-(4-diethylamino-phenyl)-5-aminothiodiazole-1,3,4 (corresponding to Formula 2) and 0.4 part by weight of 2-(4-di-n-propyl-amino-phenyl)-5-amino-thiodiazole-1,3,4 (corresponding to Formula 4) are dissolved in 40 parts by volume of ethylene glycol monoethyl ether and the solution is applied to a brushed aluminum foil.
  • Example I After evaporation of the solvent, a coating remains which adheres firmly to the surface of the foil.
  • the further procedure described in Example I is followed and an image corresponding to the master is obtained on the aluminum foil, if, after powdering over with a developer as described in Example I, the material is fixed by heating.
  • the aluminum foil thus provided with an image can be converted into a printing plate if the image side of the aluminum foil is wiped over with alcohol, rinsed with water and inked up with greasy ink together with 1% phosphoric acid.
  • a printing plate corresponding to the master is obtained. This can be set up in an offset machine and used for printing.
  • Example IV The procedure described in Example I is followed but, after the coating has dried, it is positively charged and then exposed with a positive master.
  • a positive master As the developer, a pigmented resin-carbon black mixture and glass balls covered with resin are used. A positive copy is obtained.
  • Example V 1 part by weight of 2-(4-mono-isoamylamino-phenyl)- S-amino-thiodiazole-1,3,4 (corresponding to Formula 7), 3 parts by weight of 2-(4-ethyl-n-propylamino-phenyl)-5- amino-thiodiazole-1,3,4 (corresponding to Formula 3) and 5 parts by Weight of a phenol-formaldehyde resin with a softening point of 108-118" C.commercially available under the name Alnovol 429 K-and 0.008 part by weight of Rhodamine B extra, are dissolved in parts by volume of ethylene glycol monomethyl ether. A paper is coated with the solution thus obtained. On this paper direct images are produced by the electrophotographic process in the manner described in Example I. The coatings are highly light sensitive so that images can also be produced thereon episcopically from masters with printing on both sides.
  • An electrophotographic material comprising a conductive support having a photoelectrically conductive insulating layer thereon, the latter comprising a thiodiazole having the formula in which R and R are selected from the group coni 2.
  • An electrophotographic material according to claim 1 in which the thiodiazole has the formula 6.
  • An electrophotographic material according to claim 1 in which the thiodiazole has the formula H s 7.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Indole Compounds (AREA)
US162277A 1961-01-28 1961-12-26 Material for electrophotographic purposes Expired - Lifetime US3161505A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DEK42765A DE1193363B (de) 1961-01-28 1961-01-28 Photoleitfaehige Schicht fuer elektro-photographische Zwecke

Publications (1)

Publication Number Publication Date
US3161505A true US3161505A (en) 1964-12-15

Family

ID=7222880

Family Applications (1)

Application Number Title Priority Date Filing Date
US162277A Expired - Lifetime US3161505A (en) 1961-01-28 1961-12-26 Material for electrophotographic purposes

Country Status (7)

Country Link
US (1) US3161505A (de)
BE (1) BE613171A (de)
CH (1) CH403482A (de)
DE (1) DE1193363B (de)
FR (1) FR1312797A (de)
GB (1) GB975464A (de)
NL (1) NL273707A (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3420734A (en) * 1965-04-02 1969-01-07 Crown Zellerbach Corp Process of forming electrostatic printing paper from ionic fibrous cellulosic derivatives and paper thereof
US3682942A (en) * 1970-03-19 1972-08-08 Christos George Papaioannou Preparation of 2-(2-amino-1,3,4-triadiazol-5-yl)-1-substituted-5-nitroimidazoles
US4886846A (en) * 1987-03-28 1989-12-12 Ricoh Company, Ltd. Aromatic diolefinic compounds, aromatic diethyl compounds and electrophotographic photoconductors comprising one aromatic diethyl compound

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3110957A1 (de) * 1981-03-20 1982-09-30 Basf Ag, 6700 Ludwigshafen Elektrophotographisches aufzeichnungsmaterial

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2297691A (en) * 1939-04-04 1942-10-06 Chester F Carlson Electrophotography
DE1067440B (de) * 1959-10-22 Badische Anilin- & Soda-Fabrik Aktiengesellschaft, Ludwigshafen/Rhein Verfahren zur Herstellung von 2-Amino-1,3,4-thiodiazolen
GB836148A (en) * 1956-06-27 1960-06-01 Kalle & Co Ag Improvements in or relating to photographic reproduction
US3037861A (en) * 1957-09-07 1962-06-05 Kalle Ag Electrophotographic reproduction material
US3041165A (en) * 1956-07-04 1962-06-26 Kalle Ag Electrophotographic material
US3066023A (en) * 1958-12-19 1962-11-27 Azoplate Corp Member for electrophotographic reproduction and process therefor
US3066147A (en) * 1962-11-27 X n novel j-susstituted i
US3069430A (en) * 1958-12-11 1962-12-18 Bayer Ag p-benzoquinone-monoguanylhydrazone-mono-[4-hydroxy-thiazolyl-(2)]-hydrazone and process
US3097095A (en) * 1956-11-21 1963-07-09 Azoplate Corp Material for electrophotographic reproduction

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL99369C (de) * 1956-06-04

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1067440B (de) * 1959-10-22 Badische Anilin- & Soda-Fabrik Aktiengesellschaft, Ludwigshafen/Rhein Verfahren zur Herstellung von 2-Amino-1,3,4-thiodiazolen
US3066147A (en) * 1962-11-27 X n novel j-susstituted i
US2297691A (en) * 1939-04-04 1942-10-06 Chester F Carlson Electrophotography
GB836148A (en) * 1956-06-27 1960-06-01 Kalle & Co Ag Improvements in or relating to photographic reproduction
US3041165A (en) * 1956-07-04 1962-06-26 Kalle Ag Electrophotographic material
US3097095A (en) * 1956-11-21 1963-07-09 Azoplate Corp Material for electrophotographic reproduction
US3037861A (en) * 1957-09-07 1962-06-05 Kalle Ag Electrophotographic reproduction material
US3069430A (en) * 1958-12-11 1962-12-18 Bayer Ag p-benzoquinone-monoguanylhydrazone-mono-[4-hydroxy-thiazolyl-(2)]-hydrazone and process
US3066023A (en) * 1958-12-19 1962-11-27 Azoplate Corp Member for electrophotographic reproduction and process therefor

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3420734A (en) * 1965-04-02 1969-01-07 Crown Zellerbach Corp Process of forming electrostatic printing paper from ionic fibrous cellulosic derivatives and paper thereof
US3682942A (en) * 1970-03-19 1972-08-08 Christos George Papaioannou Preparation of 2-(2-amino-1,3,4-triadiazol-5-yl)-1-substituted-5-nitroimidazoles
US4886846A (en) * 1987-03-28 1989-12-12 Ricoh Company, Ltd. Aromatic diolefinic compounds, aromatic diethyl compounds and electrophotographic photoconductors comprising one aromatic diethyl compound

Also Published As

Publication number Publication date
NL273707A (de)
CH403482A (de) 1965-11-30
DE1193363B (de) 1965-05-20
GB975464A (en) 1964-11-18
BE613171A (de)
FR1312797A (fr) 1962-12-21

Similar Documents

Publication Publication Date Title
US3112197A (en) Electrophotographic member
US3257203A (en) Electrophotographic reproduction material
US3189447A (en) Electrophotographic material and method
US3615404A (en) 1 3-phenylenediamine containing photoconductive materials
US3159483A (en) Process for the preparation of electrophotographic reversed images
US3180730A (en) Material for electrophotographic purposes
US3066023A (en) Member for electrophotographic reproduction and process therefor
US3246983A (en) Electrophotographic reproduction process
US4500622A (en) Electrophotographic light-sensitive printing materials
NO142997B (no) Laminert, bituminoest, membranformet materiale til takbelegg og lignende, samt fremgangsmaate for fremstilling av slikt materiale
US3174854A (en) Electrophotographic reproduction material
IE42855B1 (en) Material for electrophotographic reproduction
US3245783A (en) Material for electrophotographic purposes
NO150194B (no) Trekkenhet omfattende to sett nokker
US3719480A (en) Electrophotographic compositions and elements
US3097095A (en) Material for electrophotographic reproduction
DE1117391B (de) Elektrophotographisches Verfahren zur Herstellung von Druckformen
US4533612A (en) Electrophotographic recording materials containing special charge carrier-transporting compounds
US3290147A (en) Electrophotographic organic photoconductors
US3072479A (en) Electrophotographic plates comprising solid solutions of oxazolones
US3707369A (en) Photoconductive elements containing 2-methyl-3,3-dimethyl indole derivatives
US3161505A (en) Material for electrophotographic purposes
US3244517A (en) Electrophotographic process
US3301676A (en) Process and material for the production of electrophotographic images
US4229510A (en) Photoconductive polymer material of N-alkylphenothiazine and formaldehyde