Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
  • B41M5/398—Processes based on the production of stickiness patterns using powders
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used

Definitions

• a copying process which comprises preparing a copying element by applying a compound or a mineral, which releases water of crystallization when heated, on a support, placing the element on an original to be copied, subjecting the element and the original to transmittance printing or reflection printing by infrared rays, and then developing the printed copying element by applying developing powders thereon to give the desired copy.
• the image density may be increased without any increase in fog density when the exposed element is developed either with a mixture of developing powder and small particles of surfactant or with a developing powder the particles of which are at least partially coated with a surfactant.
• This invention relates to a copying process and more particularly to the use of surfactant treated developing powder and to the use of a mixture of developing powder and a fine solid surfactant for obtaining copied images by exposure to infrared rays.
• a copying element is prepared by applying or vacuum depositing on a support a compound or a mineral which releases water of crystallization when heated by the irradiation of infrared rays.
• This element is placed on an original to be copied, they are subjected to transmittance printing or reflection printing by infrared rays, and then the printed copying element is developed by applying developing powders thereon to give the desired copy.
• the image density of a copy made according to the above mentioned process is dependent on the quantity of developing powder adhered at the image portions.
• the quantity of developing powder is dependent on the adherence of the developing powder to the image portions corresponding to the pattern of the original of the copying element, said portions being wetted by the Water of crystallization released from the hydrous material of the copying element by being exposed to infrared rays.
• the quantity of the developing powder is large, the contrast of images obtained is increased, that is, copies are very clear and easy to read.
• any fine powder may be used which has a suitable grain size to adhere to portions of the copying element wetted by the water of crystallization released by heat.
• Toners used in electrophotography or electrostatic recording can be used in this process. These are dispersions of pigments in hydrophobic resins and can be fixed by heating, particularly when the resin is thermoplastic or by being subjected to a solvent vapor capable of dissolving the resin.
• Such toners are free of disadvantages, such as hygroscopic properties and are easy to handle, but in the case of using as a developing improved process for preparing a copy with increasedcontrast.
• Surfactants used as wetting agent are suitable for this invention.
• Illustrative thereof are alkyl sulfosuccinates, alkyl benzene sulfonates, alkyl esters of sorbitan, longchain hydrocarbon quaternary ammonium salts, and alkyl esters of polyoxyethylene sorbitan.
• saponin a natural wetting agent
• the fog density at non-image portions is remarkably increased.
• the surface treatment of developing powders with the above-mentioned surfactants is carried out by dispersing the commercial developing powder (for example, a finely ground pigmented resinous powder, called toner, sold by Fuji-Xerox Co., Ltd, Tokyo) in an aqueous solution of surfactants, sub jecting the resulting dispersion to vacuum drying and grinding the dried material to a grain size of 0.1 to g in diameter.
• a powder developer is blended with a finely divided surfactant, a surfactant that is solid at normal temperature is finely ground to less than 130 in diameter and mixed with a commercial developing powder.
• Example 1 Into 200 ml. of water was dissolved 15 g. of gelatin. Into the solution was added 15 g. of sodium acetate trihydrate and while stirring was added 20) ml. of ethyl alcohol. In 100 ml. of ethyl alcohol was dispersed 10 g. of barium stearate, and the thus obtained dispersion was treated in a ball mill for 12 hours to yield a smooth slurry. Thirty milliliters of the slurry was added to the abovementioned solution with stirring. Into the solution was added 3 m1. of 6% formaldehyde to obtain a coating solution. Thus prepared coating solution was coated on a cellulose triacetate film and dried to yield a copying element having ml. of the solution per square meter.
• the thus coated copying element was placed upon an original and subjected to a reflection printing process by exposing the backof the coated element to infrared rays.
• the infrared exposure was conducted using a Thermofax Model 46 Secretary Copying Machine manufactured by Sumitomo-3M Co., Tokyo.
• toner for Xerox 914 Ofiice Copier manufactured by Fuji-Xerox Cot, N d d Fog density 11mg: ai Ltd., Tokyo.
• Ten grams of the toner was dispensed in 100 developing e Q04 ml. of 0.75% aqueous solution of sodium dodecylbenzene surfactanttmated developing powder sulfonate (average chain length of alkyl group is 12.6).
• Example 4 The suspension was thoroughly stirred, dried in vacuo, and then comminuted again to less than 88p. in diameter.
• the py g element as desel'lbed 1n f ln 2 was The exposed copying element was subjected to powder used.
• the image formed was fixed by heating the copying Welgnt 0f for Xerox 914 Offiee P Wlth element or exposing the copying element to the vapor of P y Welght monolanlate p n Atlas an organic solvent, trichloroethylene. POWdel' Wllnnngton, In Slnnllaf
• the following results were obtained by measuring the 9 Example The graln SlZe 0f the thus treated transmisison (net) density of an image portion and of a p g Powder e than M- fog portion.
• Fog density Image density Fog density Image density
• Example 2 Th 1 Examp 1e 5 d h e copying e ement was prepare in t e same manner 111i? 116 l ifiisn wf $5.11? lg t b f s ocli ur i $655511? g j g 1 Of ai eyesoutionwasa e o ecoamgsouion.
• the prepared coating solution was coated part by weight of p 01 y oxyethyl an e Sorbitan monolaurajte gfi g i gg ig fi% i fi g z s fi gi g i ggg ig gzigf (number of ethylenic groups is 12) in a similari manger to Example 1.
• Example 3 Two hundred milliliters of water was charged to a juice Into 200 ml. of water was dissolved 5 g. of gelatin. Into mixer, to which 5 g. of gelatin, 5 g. of sodium acetate the solution was added 5 g. of sodium acetate trihydrate trihydrate, and a dispersion of 1 g. of zinc palmitate in and, while stirring, was added 40 ml. of ethyl alcohol. 50 ml. of ethyl alcohol was added, and stirred to obtain In 100 ml. of ethyl alcohol was dispersed 10 g. of zinc a coating solution.
• the thus prepared coating solution was palmitate, and the thus obtained dispersion was treated coated on a cellulose triacetate film and dried to yield a in a ball mill for 12 hours to yield a smooth slurry.
• Ten copying element having 20 ml. of the coating solution per milliliters of the slurry was added to the above-mentioned square meter. 0 solution with stirring.
• Into the solution was added 1 ml.
• a surfactant treated developing powder was prepared of formaldehyde to obtain a coating solution.
• pared coating solution was coated on a cellulose triacetate
• Fuji-Xerox Co., Ltd., Tokyo was dispersed in a solution of the solution per square meter. containing 100 ml. of water and 1 ml. of 30% aqueous A developing powder, the surface of which is treated solution of sodium dioctyl sulfosuccinate (Aerosol OT, with a surfactant, was prepared by treating one part by American Cyanamid Co., New York, N.Y., U.S.A.). weight of a toner for Xerox 914 Office Copier with 0.05 The suspension was thoroughly stirred, dried in vacuo, part by weight of dodecyl trimethyl ammonium chloride and then comminuted again to less than 88,11. in diameter. in a similar manner to Example 1. The grain size of the When the transmission densities of the copying element thus treated developing powder was less than 88;. in
• Example 1 were measured after exposure, developing and fixing, as in Example 1, the following differences were found between densities developed with surfactant treated developing powder and developed with non-treated developing powder.
• Example 7 Fog density Image density Toner for Xerox 914 Office Copier. Toner mixed with a surfactant It will be understood that changes may be made in the details of formulation and operation without departing from the spirit of the invention, especially as defined in the following claims.
• a process for copying which comprises placing a copying material upon an original to be copied, said copying material being one having a support bearing a heat sensitive layer of a colloidal binder and the material having water of crystallization, subjecting them to infrared exposure to liberate said water in the form of a moist latent image corresponding to the original, and developing said moist latent image with a developing powder comprising a surfactant.
• said developing powder comprises solid toner particles the surfaces of which are at least partially coated with a surfactant.
• said developing powder comprises solid toner particles. mixed with particles of a surfactant.
• the surfactant is a member selected from the: group consisting of alkyl sulfosuccinates, alkyl benzene sulfonates, alkyl esters of sorbitan, long-chain hydrocarbon quaternary ammonium salts, and alkyl esters of polyoxyethylene sorbitan.
• alkyl sulfosuccinate is sodium dioctyl sulfosuccinate.
• alkyl benzene sulfonate is sodium dodecylbenzene sulfonate.
• solid surfactant is sodium 3-hexadecyloxypropane-l-sulfonate.
• RALPH G. NILSON Primary Examiner.
• A. L. BIRCH Assistant Examiner.

Landscapes

• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Developing Agents For Electrophotography (AREA)
• Thermal Transfer Or Thermal Recording In General (AREA)
• Non-Silver Salt Photosensitive Materials And Non-Silver Salt Photography (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=11480304

Family Applications (1)

Country Status (5)

Cited By (9)

Citations (3)

• 1966
  • 1966-01-06 BE BE674776D patent/BE674776A/xx unknown
  • 1966-01-06 GB GB714/66A patent/GB1129172A/en not_active Expired
  • 1966-01-07 US US529901A patent/US3431412A/en not_active Expired - Lifetime
  • 1966-01-07 FR FR45241A patent/FR1484651A/fr not_active Expired
  • 1966-01-08 DE DE19661571831 patent/DE1571831B1/de active Pending

Patent Citations (3)

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