US3469979A - Electrophotographic recording element with increased speed - Google Patents

Electrophotographic recording element with increased speed Download PDF

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Publication number
US3469979A
US3469979A US510089A US3469979DA US3469979A US 3469979 A US3469979 A US 3469979A US 510089 A US510089 A US 510089A US 3469979D A US3469979D A US 3469979DA US 3469979 A US3469979 A US 3469979A
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US
United States
Prior art keywords
thiourea
recording element
coating
hypersensitizer
dye
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
US510089A
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English (en)
Inventor
Louis James Ferrarini
Harold J Homonoff
George R Nelson
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.)
Dennison Manufacturing Co
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Dennison Manufacturing Co
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.)
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Publication date
Application filed by Dennison Manufacturing Co filed Critical Dennison Manufacturing Co
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Publication of US3469979A publication Critical patent/US3469979A/en
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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
    • G03G5/0664—Dyes
    • 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
    • G03G5/0601—Acyclic or carbocyclic compounds
    • G03G5/062—Acyclic or carbocyclic compounds containing non-metal elements other than hydrogen, halogen, oxygen or nitrogen
    • 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
    • G03G5/0631—Heterocyclic compounds containing one hetero ring being five-membered containing two hetero atoms
    • 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
    • G03G5/0635—Heterocyclic compounds containing one hetero ring being six-membered
    • G03G5/0638—Heterocyclic compounds containing one hetero ring being six-membered containing two hetero atoms
    • 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
    • G03G5/09—Sensitisors or activators, e.g. dyestuffs

Definitions

  • This invention relates to electrophotography and has for its principal object provision of photoconductive recording elements and recording processes with increased speed of discharge upon exposure to light.
  • Electrophotography is well known and involves generally the electrostatic charging in the dark of a photoconductive layer of a recording element, and exposing the layer to a pattern of light to which the photoconductor is sensitive, thereby forming a latent image as an electrostatic charge pattern in areas not receiving light.
  • the resulting image can be electronically scanned or displayed but is usually developed to a visible image with electroscopic colored particles. The particles can then be fixed, if desired, either to the recording element itself or to a receiving surface to which they are transferred.
  • Recording elements comprising finely divided photoconductive particles dispersed in insulating resinous binders are known and are disclosed in US. Patent No. 3,121,006. Photoconductive zinc oxide in a binder is generally used and such recording elements are more specifically disclosed in US. Patent No. 3,052,539. Such recording elements are known to be sensitive to ultraviolet radiation at wavelengths of 3-800 angstroms or lower. Sensitivity refers to the capacity of the photoconductor of the recording element to dissipate electrostatic charges on its surface by a lowering of its resistivity at specified wave lengths of light.
  • the recording elements be sensitive to light at visible Wavelengths includingSOOO to 5500 angstroms. This can be accomplished by adding dye of known type as disclosed for example in the above two patents. However, dyes or a United States Patent 0 3,469,979 Patented Sept. 30, 1969:
  • hypersensitization permits use of a lesser amount of dye, a greater variety of dyes, and permits formulation of zinc oxide coatings which are more nearly White in appearance.
  • the amount of the hypersensitizer additive is not critical and the nature of the N substituents, provided they are substantially non-reactive in the coating, is not important, a large number including substantially all types currently available having been found to be useful.
  • the present invention comprises an improved electrophotographic recording element comprising a backing and a coating of finely-divided zinc oxide and finely divided sensitizing dye therefor dispersed in an insulating binder wherein the improvement consists in the dispersion within the coating of an eflective amount of a hypersensitizer for increasing the speed of discharge of the coating when electrostatically charged and exposed to light, said sensitizer consisting essentially of (a) thiourea dioxide, or (b) a compound of the structure wherein each of R R R R3 or R is selected from the group consisting of hydrogen, lower aliphatic, lower cycloaliphatic, lower acyl, aryl, and heterocyclic monovalent radicals and R and R are lower divalent aliphatic radicals.
  • the invention comprises the method of producing a latent electrostatic image comprising applying a uniform electrostatic charge to the above improved recording element in the dark, that is, the absence of radiation to which the photoconductor is sensitive, and exposing the element to a pattern of light to which the photoconductor is sensitive.
  • the effect of the hypersensitizer is shown in the following examples, the compositions stated being coated onto paper 0.0022 inch in thickness and having a resistivity at 20% relative humidity of 1000 megohms.
  • the coating compositions were applied and dried to a thickness of about 0.0008 inch. After storage in the dark at 20% R.H., they were charged to approximately 500 volts using a negative corona at 7.4 kv. grounded with a positive corona of 3.0 kv.
  • the discharge time was the time in seconds to discharge to 5 volts upon exposure to 2.0 foot candles of light from a General Electric Photo flood lamp EPR of 375 watts. The time lapse between charging' and exposure in each case was about 8 seconds. Voltages were measured as apparent surface voltage with the equipment and procedure described in E. Giamo, RCA Review, volume XXII, No. 4, pages 780-790 of December 1961. All parts are by weight except where otherwise indicated.
  • N,N -ethylenethiourea N methyl thiourea N,N dimethyl thiourea 1,3 diethyl, 2 thiourea 1,3 dibutyl thiourea N acetyl thiourea. 1 allyl, 2 thiourea 3 allyl1,1 diethyl, 2 thiourea 1 phenyl, 2 thiourea 1,1 diphenyl, 2 thiourea N,N dicyclohexyl thiourea.
  • N,N dimethyl N (p tolyl) thiourea Thiourea dioxide 23-- O methoxyphenyl thiourea 24 N,N dimethyl thiourea
  • the zinc oxide was Florence Green Seal No. 8 of the New Jersey Zinc Co.
  • Acryloid B-82 as a 40% solution in toluene of an acrylic polymer from Rohm and Haas Co.
  • the alpha-methyl styrene was 4 Resin 276 V2 of the Dow Chemical Company
  • the sensitizing dye solution had the following composition:
  • Eosin 0 Acid Red 87 (a hydroxyphthalein dye), 1% Calco fiuorescein, Acid Yellow 73, 1% Brom phenol blue (3,3,3,5-tetrabrorno-phenol sulphionphthalein), 1% 0.26 Brilliant Yellow 6G, 1% 0.84
  • the samples were prepared by dispersing the zinc oxide in the solvent, adding the resins, dye solution, and hypersensitizer, the resulting suspension coated onto the paper base and the coating dried, for example for one minute at C.
  • Examples 25-33 were prepared using the Zinc oxide and resin formulation and procedure of Examples 1-24 but substituting the indicated dyes and additive in the quantity of toluene solvent indicated in ml. Exposure time was the time in seconds to discharge to 5 volts apparent surface voltage.
  • Hypersensi- Initial Exposure Solvent Dye tizer charge time The dye employed in Examples 25-33 was a 1% solution of Calco Florescein of the American Cyanamid Co. in methyl Cellosolve, the amounts indicated being in ml.
  • the hypersensitizer was 2 mercapto imidazoline, the amount being in grams. At 3 ml. of dye solution, the zinc oxide coating exhibited some color. While these data show that amount is not critical, Example 29 with 1.0 part by weight hypersensitizer per parts zinc oxide with minimum dye is preferred.
  • Examples 34 to 61 were prepared using Formula B of Examples 1 to 24 together with the dyes indicated in the following Examples 34 to 61, the dye amounts being in ml. of a 1% solution of the dye in methyl Cellosolve.
  • An improved electrophotographic recording element comprising a backing and a coating thereon of finely divided photoconductive zinc oxide and sensitizing dyes therefor dispersed in an insulating binder wherein the improvement consists in the dispersion within the coating of an effective amount of a hypersensitizer for increasing the speed of discharge of the coating when electrostatically charged and exposed to light, said hypersensitizer selected from the group consisting essentially of (a) thiourea dioxide or (b) a compound having the structure wherein each of R R R R and R is selected from the group consisting of hydrogen, lower aliphatic, lower cycloaliphatic, lower acyl, aryl, and heterocyclic monovalent radicals and R and R are lower divalent aliphatic radicals, said heterocyclic radical consisting essentially of a six-membered ring of carbon, nitrogen and oxygen.
  • a hypersensitizer selected from the group consisting essentially of (a) thiourea dioxide or (b) a compound having the
  • a recording element wherein said backing is paper and said hypersensitizer is selected from the group consisting of N,N-ethylenethiourea; N methyl thiourea; N,N dimethyl thiourea; 1,3 diethyl, 2 thiourea; 1,3 dibutyl thiourea; N acetyl thiourea; 1 allyl, 2 thiourea; 3 allyl 1, 1 diethyl, 2 thiourea; 1 phenyl, 2 thiourea; 1,1 diphenyl, 2 thiourea; N,N dicyclohexyl thiourea; 1 cyclohexyl, 3(2 morpholinoethyl) thiourea; thiourea; 1,3 bis (carboxypentyl) thiourea; N,N bis (4 fluorophenyl) thiourea; N,N di tert-butyl thioure
  • the method of producing a latent electrostatic image which comprises applying a uniform electrostatic charge in the dark to the coating of the recording element of claim 1 and exposing the coating to a pattern of light.
  • the method of producing a latent electrostatic image which comprises applying a uniform electrostatic charge in the dark to the coating of the recording element of claim 2 and exposing the coating to a pattern of light.
  • the method of producing a latent electrostatic image which comprises applying a uniform electrostatic charge in the dark to the coating of the recording element of claim 3 and exposing the coating to a pattern of light.
  • the method of producing a latent electrostatic image which comprises applying a uniform electrostatic charge in the dark to the coating of the recording element of claim 4 and exposing the coating to a pattern of light.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Heat Sensitive Colour Forming Recording (AREA)
  • Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)
US510089A 1965-11-26 1965-11-26 Electrophotographic recording element with increased speed Expired - Lifetime US3469979A (en)

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US51008965A 1965-11-26 1965-11-26

Publications (1)

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US3469979A true US3469979A (en) 1969-09-30

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US (1) US3469979A (enrdf_load_html_response)
BE (1) BE690270A (enrdf_load_html_response)
DE (1) DE1522576B2 (enrdf_load_html_response)
FR (1) FR1501634A (enrdf_load_html_response)
GB (1) GB1128479A (enrdf_load_html_response)
NL (1) NL6616727A (enrdf_load_html_response)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4820620A (en) * 1986-07-17 1989-04-11 Minnesota Mining And Manufacturing Company Supersensitization of and reduction of dark decay rate in photoconductive films
US4911999A (en) * 1988-12-13 1990-03-27 E. I. Du Pont De Nemours And Company Electrostatic master containing thiourea or thioamide electrostatic decay additive for high speed xeroprinting
US5185227A (en) * 1990-08-28 1993-02-09 Oji Paper Co., Ltd. Electrophotographic lithograph printing plate material

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5865438A (ja) * 1981-10-15 1983-04-19 Fuji Photo Film Co Ltd 光導電性組成物およびそれを用いた電子写真感光材料

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3031301A (en) * 1959-03-30 1962-04-24 Gen Electric Photosensitive resin compositions
US3352670A (en) * 1964-02-14 1967-11-14 Minnesota Mining & Mfg Supersensitizers for optically sensitized photoconductive layers

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3031301A (en) * 1959-03-30 1962-04-24 Gen Electric Photosensitive resin compositions
US3352670A (en) * 1964-02-14 1967-11-14 Minnesota Mining & Mfg Supersensitizers for optically sensitized photoconductive layers

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4820620A (en) * 1986-07-17 1989-04-11 Minnesota Mining And Manufacturing Company Supersensitization of and reduction of dark decay rate in photoconductive films
US4911999A (en) * 1988-12-13 1990-03-27 E. I. Du Pont De Nemours And Company Electrostatic master containing thiourea or thioamide electrostatic decay additive for high speed xeroprinting
US5185227A (en) * 1990-08-28 1993-02-09 Oji Paper Co., Ltd. Electrophotographic lithograph printing plate material

Also Published As

Publication number Publication date
DE1522576A1 (de) 1970-02-26
NL6616727A (enrdf_load_html_response) 1967-05-29
FR1501634A (fr) 1967-11-10
BE690270A (enrdf_load_html_response) 1967-05-25
GB1128479A (en) 1968-09-25
DE1522576B2 (de) 1971-04-29

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