[go: up one dir, main page]

US3909256A - Electrostatographic process for preparing screen printing member - Google Patents

Electrostatographic process for preparing screen printing member Download PDF

Info

Publication number
US3909256A
US3909256A US427591A US42759173A US3909256A US 3909256 A US3909256 A US 3909256A US 427591 A US427591 A US 427591A US 42759173 A US42759173 A US 42759173A US 3909256 A US3909256 A US 3909256A
Authority
US
United States
Prior art keywords
screen
image
liquid
voids
electrostatic attraction
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
US427591A
Inventor
John B Wells
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.)
Xerox Corp
Original Assignee
Xerox 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 Xerox Corp filed Critical Xerox Corp
Priority to US427591A priority Critical patent/US3909256A/en
Priority to DE19742456316 priority patent/DE2456316A1/en
Priority to JP14627074A priority patent/JPS5096306A/ja
Priority to FR7442921A priority patent/FR2256447A1/en
Priority to NL7416963A priority patent/NL7416963A/en
Application granted granted Critical
Publication of US3909256A publication Critical patent/US3909256A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/12—Production of screen printing forms or similar printing forms, e.g. stencils
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F5/00—Screening processes; Screens therefor
    • G03F5/20—Screening processes; Screens therefor using screens for gravure printing
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G13/00—Electrographic processes using a charge pattern
    • G03G13/26—Electrographic processes using a charge pattern for the production of printing plates for non-xerographic printing processes
    • G03G13/32—Relief printing plates

Definitions

  • the method comprises coating the voids of a suitable screen with a liquid but hardenable material which is impervious to a printing fluid and not dissolvable by said printing fluid and which has a viscosity and conductivity to permit removal by electrostatic attraction, contacting said screen in the absence of light with a member having an electrostatographic latent image, separating the screen and imaged member whereby the liquid is removed from the screen by electrostatic attraction in the charged areas of the image to provide voids in image configuration and hardening the liquid in the noncharged areas to form an imaged stencil master.
  • imaged stencils consist essentially of ink-impervious coatings cut to expose a permeable sheet that permits ink to pass through.
  • the stencils are wrapped around a rotating drum of a duplicator. This drum is perforated to permit ink brushed through it to pass to the stencil to image paper fed against the stencil on the drum.
  • stencils can be prepared rapidly by an inexpensive simple camera speed imaging process. More particularly, it has been found that when the voids of a screen are filled by coating with a liquid but hardenable material which is impervious to a printing fluid, not dissolvable by said printing fluid and which has a viscosity and conductivity to permit removal by electrostatic attraction, the screen can be contacted in the absence of light with a member having an electrostatographic latent image and the members separated to cause the liquid to be removed from the screen by electrostatic attraction in the charged areas of the image to provide voids in image configuration, and the liquid can be hardened in the remaining areas to form an imaged stencil master.
  • the stencil is formed from a screen, it is not necessary to use etch solutions in order to form the image but rather the liquid can be removed from the screen to provide voids by simple electrostatic attraction.
  • the stencils can be prepared from conventional materials and employed for both screen process printing and mimeograph duplicating. Other benefits will be apparent from the following detailed description.
  • Screens which can be employed for the printing stencil include mesh, fabric or cloth formed of any weavable material such as silk, nylon, Dacron and the like fibers as well as metal wires such, for example, as stainless steel.
  • the screen will preferably have from 100 X 100 to 250 X 250 US. mesh, although larger and smaller screens can be employed.
  • Liquid materials suitable for filling the screen member include waxes, and a variety of natural polymerizable monomers and synthetic polymers which are of a low viscosity or can be made of a low viscosity. It is only necessary that the material be sufficiently liquid when applied to the screen such that it fills the voids, that the material can be hardened such that it is impervious to the printing fluid employed and not dissolvable by the printing fluid, and that the fluid can be removed from the screen by electrostatic attraction. Thus it can be appreciated that a large number of materials can be employed.
  • the liquid but hardenable material can be removed from the screen member by capillary action even if the viscosity is high when the members are contacted with the imaging member for a relatively long time. It is preferred, however, that the liquid material have a sufficiently low viscosity and resistivity that they can be quickly removed by use of an electrostatic field. Nearly all of the materials are sufficiently conductive as it is only necessary to have a resistivity of less than 10 ohm/cm and for the few materials which are below this conductivity, a common electrolyte such as salt can be added. Likewise, the viscosity is not a critical parameter, it only being necessary for optimum results that the liquid material and ink can be selectively removed by an electrostatic field. In order to obtain the desired viscosity, the monomers or polymers can be dissolved in a suitable solvent in which they are soluble, as is well known to those skilled in the art.
  • the liquid materials which can be employed to fill the screen member include materials which are hardenable at ambient temperature, or elevated temperature and which can be hardened or cured by cooling, air, or some form of radiant energy such as heat and ultraviolet light. Photo-hardenable polymers which can be cured by light are particularly preferred as it is not necessary to adjust the temperature of the screen member.
  • the particular liquid employed will depend on the desired life of the screen member, the substrate to which it is to be adhered and other variables such as cost and availability.
  • Waxes can be employed which are solid at room temperature and can be made liquid at elevated temperature. Representative examples include: beeswax, carnauba wax, parafin waxes and the like. Preferred waxes are those melting below C and most preferably below 60C.
  • Liquid polymers which can be employed to fill the screen member include low viscosity thermoplastics, thermosetting plastics thermosetting resins and photopolymers.
  • suitable thermoplastics are polyethylene, polypropylene, ethylene-vinyl acetate copolymers, propylene-modified polyethylene, acetals, acrylics, acrylonitrile-butadiene-styrene (ABS), polystyrene, cellulosics, shellac, chlorinated polyether, fluorochemicals, polyamides (nylons), polyimides, phenoxies, and vinyls.
  • thermosetting plastics are aminoplasts (urea-formaldehyde, melamine-formaldehyde), phenolics, epoxies, diphenyl oxide, polyurethanes, polyesters, diallyl phthalates, and silicones.
  • thermosetting resins are vinyl, acrylic, alkyd, polyurethane, silicone, phenolic, and epoxy resins.
  • Polymerizable monomers can also be employed to fill the screen member.
  • monomers such as methyl, ethyl and propyl methacrylate, styrene and pivalolactone can be employed with an initiator.
  • Initiators which can be employed to polymerize the aforesaid monomers (other than pivalolactone) include conventional materials such as for example, benzoyl peroxide, and azo-bis(isobutyronitrile).
  • An initiator for pivalolactone is triphenyl phosphine. A number of materials can be employed and it is only necessary that the initiator or catalyst be soluble in the monomer or very finely dispersed.
  • photopolyrners are the cinnamic resins of polyvinyl alcohol, cellulose, starch and the epoxy resin of epichlorohydrin and 4,4- isopropylidenediphenol.
  • Polymethacrylate and polyamide coatings can also be employed when mixed with photosensitive polymerizable materials.
  • the screen member can be filled by conventional means. For example, it may be clipped in the liquid material ordraw bar coated.
  • thermoplastic materials and waxes which are solid at ambient temperature can be converted to a low viscosity by heat so as to render them electrostatically removable.
  • thermosetting polymers are liquid at ambient temperature or below their curing temperature and the'photopolymers are liquid until cured such as by ultraviolet light.
  • a screen member can be prepared by filling the voids of the screen member at elevated temperature with a wax or thermoplastic material and then allowing the material to harden by cooling.
  • the material can be softened by heat to fluidize the material so as to permit removal in the charged areas by electrostatic attraction.
  • the screen In order to prevent the removal of the liquid material from the screen network (i.e. threads or lines of the screen) and from the interstices in the nonimaged areas because of physical contact when the screen and imaging member are contacted and separated, it may be necessary that the screen be doctored, after the voids are filled and before imaging, with a flexible doctor blade such as soft rubber, nylon or polyurethane. In this manner, the fluid is removed from the lands, and below the contact plane of the interstices so that when the screen is contacted with and separated from the image member, the liquid is removed from the screen by electrostatic attraction in the charged areas of the image and not from the noncharged areas by physical contact. Whether or not it will be required to doctor the screen depends upon the method of application of the liquid material, its consistency and affinity for the screen network.
  • the electrostatographic image can be formed by conventional means such as xerography.
  • a photoreceptor imaging member such as a zinc oxide paper master or a selenium drum.
  • the electrostatographic latent image on the imaged member is contacted to the coated screen in the absence of light and the two members quickly separated.
  • the contact and separation of the two members causes the liquid to be removed from the screen in areas corresponding to the charged areas.
  • the liquid remaining in the noncharged areas on the screen can then be hardened by heat, air, ultraviolet light or the like, the particular treatment depending on the material employed as the liquid. Images of either positive or negative sense can be formed.
  • Typical photoreceptors include inorganic materials such as cadmium sulfide, cadmium sulfoselenide, mercuric sulfide, lead oxide, lead sulfide, cadmium selenide and mixtures thereof dispersed in binder or as homogeneous layers.
  • Typical organic photoreceptors include pigments such as quinacridones, carboxanilides, triazines and the like.
  • the electrostatographic latent image can be transferred directly from a photoreceptor to the screen member or it can be first transferred to a dielectric material such as Mylar polyester and the dielectric material contacted with the screen member.
  • the electrostatographic image can be formed without the use of a photoconductor by applying a metal stencil over a dielectric member such as a polyester film and the surface charged according to. the pattern in the stencil. The charged film is contacted to the screen member, separated and the fluid hardened in the nonimage areas as described above.
  • Typical inks and printing equipment can be employed with the stencil master of the invention.
  • Typical inks include inks of the rubber or oleophilic type having the vehicle component for the ink pigments derived from various oleophilic materials such as aromatic and aliphatic hydrocarbons, drying oil varnishes, lacquers and solvent-type resins.
  • An ink or printing fluid should be selected which is compatible with the coated screen member.
  • the imaged stencil can then be affixed to a duplicator or conventional frame such as wood or steel, the screen placed against a receiver member and ink pushed through the image voids and onto the receiver member by conventional means.
  • a stencil was prepared as follows. An X 80 U.S. mesh stainless steel screen was heated to above 50C by means of a Will Scientific Company heat gun and then coated with a liquid paraffin wax, M.P. 5052C (Bolar Chemical No. 1413) by dipping the screen in the melted wax. A zinc oxide photoreceptive paper (Brunning 2,000) was charged with negative corona and exposed to a silver halide positive transparency producing an electrostatographic latent image positive in sense. The charged paper was contacted by hand to the screen in the dark, and then separated. The screen was then allowed to cool to room temperature to harden the wax. In roorn light, a wax positive image was found on the screen consisting of voids or perforations in image configuration. The screen was then placed over a sheet of paper and an ink roller run over the screen to force ink through the voids and the image was reproduced on the paper. The printing step was repeated several times and prints of good contrast were obtained.
  • Example II The procedure of Example I was repeated but with the following exceptions.
  • the wax in Example I is replaced with a catalyzed but uncured silicone elastomer gum [30 percent by weight poly(dimethylsiloxane) in xylene sold by Dow Corning under the designation Silastic No. 182 for use as a release agent for paper], and the screen doctored with a flexible blade. After imaging the screen is placed in an oven for approximately 2 hours at 170C and the silicone gum hardened. Prints of good image contrast were obtained, employing the screen.
  • a method for preparing a stencil comprising providing a suitable screen, coating the voids of said screen with a liquid material hardenable at ambient or elevated temperature which is impervious to a printing fluid and not dissolvable by said printing fluid and which has a viscosity and conductivity sufficient to permit removal by electrostatic attraction, said conductivity being less than ohm/cm, contacting said coated screen in the absence of light with a member having an electrostatographic latent image separating the members whereby liquid is removed from the screen by electrostatic attraction in the charged areas of the image to provide voids in image configuration and hardening the liquid in the noncharged areas to form an imaged stencil.
  • a method of printing comprising providing a suitable screen, coating the voids of said screen with a liquid material hardenable at ambient or elevated temperature which is impervious to a printing fluid and not dissolvable by said printing fluid and which has a viscosity and conductivity sufficient to permit removal by electrostatic attraction, said conductivity being less than 10 ohm/cm, contacting said coated screen in the absence of light with a member having an electrostatographic latent image, separating the members whereby the liquid is removed from the screen by electrostatic attraction in the charged areas of the image to provide voids in image configuration and hardening the liquid in the nonimaged areas to form an imaged stencil, contacting the resultant stencil with an image receiving member and passing ink through said voids to thereby form an inked image on said receiving member.
  • electrostatographic latent image member contains an image which is negative in sense and the screen is biased to a potential which is approximately the same as those areas of the image member which are of the higher potential so that when the members are contacted and separated, an image is provided which is positive in sense.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Printing Plates And Materials Therefor (AREA)
  • Manufacture Or Reproduction Of Printing Formes (AREA)

Abstract

A novel method for preparing a stencil master is provided. The method comprises coating the voids of a suitable screen with a liquid but hardenable material which is impervious to a printing fluid and not dissolvable by said printing fluid and which has a viscosity and conductivity to permit removal by electrostatic attraction, contacting said screen in the absence of light with a member having an electrostatographic latent image, separating the screen and imaged member whereby the liquid is removed from the screen by electrostatic attraction in the charged areas of the image to provide voids in image configuration and hardening the liquid in the noncharged areas to form an imaged stencil master.

Description

1451 Sept. 30, 1975 1 1 ELECTROSTATOGRAPHIC PROCESS FOR PREPARING SCREEN PRINTING MEMBER John B. Wells, Savannah, NY.
[73] Assignee: Xerox Corporation, Stamford,
Conn.
[22] Filed: Dec. 26, 1973 [21] Appl. No.: 427,591
[75] Inventor:
2,949,849 8/1960 Gundlach 3,445,226 3/1969 Gundlach et a1. 96/1 R X 3,559,570 2/1971 Martel et a1. 96/1 R X 3,561,358 2/1971 Weigl 96/1 R X 3,589,289 6/1971 Gosnell et a1... 101/170 X 3,676,215 6/1972 Gundlach 96/1 LY X 3,687,072 8/1972 Pym 101/170 X 3,795,530 3/1974 Gundlach.. 96/1 LY X 3,801,315 4/1974 Gundlach et 96/1 LY X 3,806,354 4/1974 Amidon ct al 96/1 LY X Primary ExaminerNorman G. Torchin Assistant E.\aminer.lohn R. Miller Attorney, Agent, or Firm-James J. Ralabate; James P. OSullivan; Donald M. MacKay 5 7 1 ABSTRACT A novel method for preparing a stencil master is provided. The method comprises coating the voids of a suitable screen with a liquid but hardenable material which is impervious to a printing fluid and not dissolvable by said printing fluid and which has a viscosity and conductivity to permit removal by electrostatic attraction, contacting said screen in the absence of light with a member having an electrostatographic latent image, separating the screen and imaged member whereby the liquid is removed from the screen by electrostatic attraction in the charged areas of the image to provide voids in image configuration and hardening the liquid in the noncharged areas to form an imaged stencil master.
12 Claims, No Drawings ELECTROSTATOGRAPI-IIC PROCESS FOR PREPARING SCREEN PRINTING MEMBER BACKGROUND OF THE INVENTION In stencil printing a porous-filled sheet is opened up where it is desired to make an ink flow for imaging; no ink can pass through unopened, blocked areas. Stencil printing includes both screen process printing and mimeograph duplicating. Stencil screens can be made by photoresists. For example, gelatin can be coated on a screen, sensitized by dichromate solution, dried, exposed and washed out to give an imaged screen. Ink can pass through where light has not struck. In mimeograph duplicating, imaged stencils consist essentially of ink-impervious coatings cut to expose a permeable sheet that permits ink to pass through. The stencils are wrapped around a rotating drum of a duplicator. This drum is perforated to permit ink brushed through it to pass to the stencil to image paper fed against the stencil on the drum.
In general, the processes for producing stencils are costly and time consuming. It is to this problem that this invention is directed.
DESCRIPTION OF THE INVENTION It has now been discovered that stencils can be prepared rapidly by an inexpensive simple camera speed imaging process. More particularly, it has been found that when the voids of a screen are filled by coating with a liquid but hardenable material which is impervious to a printing fluid, not dissolvable by said printing fluid and which has a viscosity and conductivity to permit removal by electrostatic attraction, the screen can be contacted in the absence of light with a member having an electrostatographic latent image and the members separated to cause the liquid to be removed from the screen by electrostatic attraction in the charged areas of the image to provide voids in image configuration, and the liquid can be hardened in the remaining areas to form an imaged stencil master. Thus because the stencil is formed from a screen, it is not necessary to use etch solutions in order to form the image but rather the liquid can be removed from the screen to provide voids by simple electrostatic attraction. In addition, it is not necessary to form light sensitive coatings on the screen as the image can be easily and rapidly formed on a photoconductive paper such as a conventional zinc oxide master and the screen imaged by contacting the charged master with the screen and separating the members to remove the liquid from the screen in image configuration. Further,.the stencils can be prepared from conventional materials and employed for both screen process printing and mimeograph duplicating. Other benefits will be apparent from the following detailed description.
DETAILED DESCRIPTION OF THE INVENTION Screens which can be employed for the printing stencil include mesh, fabric or cloth formed of any weavable material such as silk, nylon, Dacron and the like fibers as well as metal wires such, for example, as stainless steel. The screen will preferably have from 100 X 100 to 250 X 250 US. mesh, although larger and smaller screens can be employed.
Liquid materials suitable for filling the screen member include waxes, and a variety of natural polymerizable monomers and synthetic polymers which are of a low viscosity or can be made of a low viscosity. It is only necessary that the material be sufficiently liquid when applied to the screen such that it fills the voids, that the material can be hardened such that it is impervious to the printing fluid employed and not dissolvable by the printing fluid, and that the fluid can be removed from the screen by electrostatic attraction. Thus it can be appreciated that a large number of materials can be employed.
The liquid but hardenable material can be removed from the screen member by capillary action even if the viscosity is high when the members are contacted with the imaging member for a relatively long time. It is preferred, however, that the liquid material have a sufficiently low viscosity and resistivity that they can be quickly removed by use of an electrostatic field. Nearly all of the materials are sufficiently conductive as it is only necessary to have a resistivity of less than 10 ohm/cm and for the few materials which are below this conductivity, a common electrolyte such as salt can be added. Likewise, the viscosity is not a critical parameter, it only being necessary for optimum results that the liquid material and ink can be selectively removed by an electrostatic field. In order to obtain the desired viscosity, the monomers or polymers can be dissolved in a suitable solvent in which they are soluble, as is well known to those skilled in the art.
The liquid materials which can be employed to fill the screen member include materials which are hardenable at ambient temperature, or elevated temperature and which can be hardened or cured by cooling, air, or some form of radiant energy such as heat and ultraviolet light. Photo-hardenable polymers which can be cured by light are particularly preferred as it is not necessary to adjust the temperature of the screen member. The particular liquid employed will depend on the desired life of the screen member, the substrate to which it is to be adhered and other variables such as cost and availability.
Waxes can be employed which are solid at room temperature and can be made liquid at elevated temperature. Representative examples include: beeswax, carnauba wax, parafin waxes and the like. Preferred waxes are those melting below C and most preferably below 60C.
Liquid polymers which can be employed to fill the screen member include low viscosity thermoplastics, thermosetting plastics thermosetting resins and photopolymers. Exemplary of suitable thermoplastics are polyethylene, polypropylene, ethylene-vinyl acetate copolymers, propylene-modified polyethylene, acetals, acrylics, acrylonitrile-butadiene-styrene (ABS), polystyrene, cellulosics, shellac, chlorinated polyether, fluorochemicals, polyamides (nylons), polyimides, phenoxies, and vinyls. examplary of suitable thermosetting plastics are aminoplasts (urea-formaldehyde, melamine-formaldehyde), phenolics, epoxies, diphenyl oxide, polyurethanes, polyesters, diallyl phthalates, and silicones. Exemplary of thermosetting resins are vinyl, acrylic, alkyd, polyurethane, silicone, phenolic, and epoxy resins.
Polymerizable monomers can also be employed to fill the screen member. For example, monomers such as methyl, ethyl and propyl methacrylate, styrene and pivalolactone can be employed with an initiator. Initiators which can be employed to polymerize the aforesaid monomers (other than pivalolactone) include conventional materials such as for example, benzoyl peroxide, and azo-bis(isobutyronitrile). An initiator for pivalolactone is triphenyl phosphine. A number of materials can be employed and it is only necessary that the initiator or catalyst be soluble in the monomer or very finely dispersed.
Exemplary of suitable photopolyrners are the cinnamic resins of polyvinyl alcohol, cellulose, starch and the epoxy resin of epichlorohydrin and 4,4- isopropylidenediphenol. Polymethacrylate and polyamide coatings can also be employed when mixed with photosensitive polymerizable materials.
The screen member can be filled by conventional means. For example, it may be clipped in the liquid material ordraw bar coated.
The thermoplastic materials and waxes which are solid at ambient temperature can be converted to a low viscosity by heat so as to render them electrostatically removable. The thermosetting polymers are liquid at ambient temperature or below their curing temperature and the'photopolymers are liquid until cured such as by ultraviolet light.
If desired, a screen member can be prepared by filling the voids of the screen member at elevated temperature with a wax or thermoplastic material and then allowing the material to harden by cooling. When it is desired to image the screen member, the material can be softened by heat to fluidize the material so as to permit removal in the charged areas by electrostatic attraction.
In order to prevent the removal of the liquid material from the screen network (i.e. threads or lines of the screen) and from the interstices in the nonimaged areas because of physical contact when the screen and imaging member are contacted and separated, it may be necessary that the screen be doctored, after the voids are filled and before imaging, with a flexible doctor blade such as soft rubber, nylon or polyurethane. In this manner, the fluid is removed from the lands, and below the contact plane of the interstices so that when the screen is contacted with and separated from the image member, the liquid is removed from the screen by electrostatic attraction in the charged areas of the image and not from the noncharged areas by physical contact. Whether or not it will be required to doctor the screen depends upon the method of application of the liquid material, its consistency and affinity for the screen network.
The electrostatographic image can be formed by conventional means such as xerography. By this method the image is formed on a photoreceptor imaging member such as a zinc oxide paper master or a selenium drum. Then the electrostatographic latent image on the imaged member is contacted to the coated screen in the absence of light and the two members quickly separated. The contact and separation of the two members causes the liquid to be removed from the screen in areas corresponding to the charged areas. The liquid remaining in the noncharged areas on the screen can then be hardened by heat, air, ultraviolet light or the like, the particular treatment depending on the material employed as the liquid. Images of either positive or negative sense can be formed.
In addition to the photoreceptors mentioned, other conventional photoreceptors can be employed. Typical photoreceptors include inorganic materials such as cadmium sulfide, cadmium sulfoselenide, mercuric sulfide, lead oxide, lead sulfide, cadmium selenide and mixtures thereof dispersed in binder or as homogeneous layers. Typical organic photoreceptors include pigments such as quinacridones, carboxanilides, triazines and the like. The electrostatographic latent image can be transferred directly from a photoreceptor to the screen member or it can be first transferred to a dielectric material such as Mylar polyester and the dielectric material contacted with the screen member. Further, the electrostatographic image can be formed without the use of a photoconductor by applying a metal stencil over a dielectric member such as a polyester film and the surface charged according to. the pattern in the stencil. The charged film is contacted to the screen member, separated and the fluid hardened in the nonimage areas as described above.
When it is desired to make a positive image from an image which is negative in sense, one may charge and expose a photoconductor to activating electromagnetic radiation to provide a negative image and bias (charge) the screen to a potential which is approximately the same as those areas of the image which are of the higher potential so that when the two members are contacted and separated,-the nonimage areas are developed to provide a stencil with an image which is posi tive in sense. I
Typical inks and printing equipment can be employed with the stencil master of the invention. Typical inks include inks of the rubber or oleophilic type having the vehicle component for the ink pigments derived from various oleophilic materials such as aromatic and aliphatic hydrocarbons, drying oil varnishes, lacquers and solvent-type resins. An ink or printing fluid should be selected which is compatible with the coated screen member.
The imaged stencil can then be affixed to a duplicator or conventional frame such as wood or steel, the screen placed against a receiver member and ink pushed through the image voids and onto the receiver member by conventional means.
The following examples will serve to illustrate the invention. All parts and percentages in said examples and elsewhere in the specification and claims are by weight unless otherwise specified.
EXAMPLE I A stencil was prepared as follows. An X 80 U.S. mesh stainless steel screen was heated to above 50C by means of a Will Scientific Company heat gun and then coated with a liquid paraffin wax, M.P. 5052C (Bolar Chemical No. 1413) by dipping the screen in the melted wax. A zinc oxide photoreceptive paper (Brunning 2,000) was charged with negative corona and exposed to a silver halide positive transparency producing an electrostatographic latent image positive in sense. The charged paper was contacted by hand to the screen in the dark, and then separated. The screen was then allowed to cool to room temperature to harden the wax. In roorn light, a wax positive image was found on the screen consisting of voids or perforations in image configuration. The screen was then placed over a sheet of paper and an ink roller run over the screen to force ink through the voids and the image was reproduced on the paper. The printing step was repeated several times and prints of good contrast were obtained.
EXAMPLE II The procedure of Example I was repeated but with the following exceptions. The wax in Example I is replaced with a catalyzed but uncured silicone elastomer gum [30 percent by weight poly(dimethylsiloxane) in xylene sold by Dow Corning under the designation Silastic No. 182 for use as a release agent for paper], and the screen doctored with a flexible blade. After imaging the screen is placed in an oven for approximately 2 hours at 170C and the silicone gum hardened. Prints of good image contrast were obtained, employing the screen.
Having described the present invention with reference to these specific embodiments, it is to be understood that numerous variations may be made without departing from the spirit of the present invention and it is intended to encompass such reasonable variations or equivalents within its scope.
What is claimed is:
1. A method for preparing a stencil comprising providing a suitable screen, coating the voids of said screen with a liquid material hardenable at ambient or elevated temperature which is impervious to a printing fluid and not dissolvable by said printing fluid and which has a viscosity and conductivity sufficient to permit removal by electrostatic attraction, said conductivity being less than ohm/cm, contacting said coated screen in the absence of light with a member having an electrostatographic latent image separating the members whereby liquid is removed from the screen by electrostatic attraction in the charged areas of the image to provide voids in image configuration and hardening the liquid in the noncharged areas to form an imaged stencil.
2. The process of claim 1 wherein the voids of the screen are coated with a silicone.
3. The process of claim 1 wherein the image on the image member is xerographically formed by charging a photoconductive layer and exposing said layer to imagewise light to form an electrostatographic latent image.
4. The process of claim 1 wherein the image member comprises zinc oxide photoreceptive paper.
5. The process of claim 1 wherein the screen is a metal screen.
6. The process of claim 1 wherein the screen is formed of stainless steel.
7. The process of claim 1 wherein the screen has a mesh size of from 60 to 325 U.S. mesh.
8. The process of claim 1 wherein the screen has a mesh size of from to 250 U.S. mesh.
9. A method of printing comprising providing a suitable screen, coating the voids of said screen with a liquid material hardenable at ambient or elevated temperature which is impervious to a printing fluid and not dissolvable by said printing fluid and which has a viscosity and conductivity sufficient to permit removal by electrostatic attraction, said conductivity being less than 10 ohm/cm, contacting said coated screen in the absence of light with a member having an electrostatographic latent image, separating the members whereby the liquid is removed from the screen by electrostatic attraction in the charged areas of the image to provide voids in image configuration and hardening the liquid in the nonimaged areas to form an imaged stencil, contacting the resultant stencil with an image receiving member and passing ink through said voids to thereby form an inked image on said receiving member.
10. The method of claim 1 wherein the screen is coated with the liquid material, and doctored with a flexible blade to remove the liquid from the contact plane so that when the screen is contacted with and separated from the image member, the liquid is removed from the screen only by electrostatic attraction.
11. The method of claim 1 wherein the electrostatographic latent image member contains an image which is negative in sense and the screen is biased to a potential which is approximately the same as those areas of the image member which are of the higher potential so that when the members are contacted and separated, an image is provided which is positive in sense.
12. The method of claim 9 wherein the screen is coated with the liquid material, and doctored with a flexible blade to remove the liquid from the contact plane so that when the screen is contacted with and separated from the image member, the liquid is removed from the screen only by electrostatic attraction.

Claims (12)

1. A METHOD FOR PREPARING A STENCIL COMPRISING PROVIDING A SUITABLE SCREEN, COATING THE VOIDS OF SAID SCREEN WITH A LIQUID MATERIAL HARDENABLE AT AMBIENT OR ELEVATED TEMPERATURE WHICH IS IMPERVIOUS TO A PRINTING FLUID AND NOT DISSOLVABLE BY SAID PRINTING FLUID AND WHICH HAS A VISCOSITY AND CONDUCTIVITY SUFFICIENT TO PERMIT REMOVAL BY ELECTROSTATIC ATTRACTION, SAID CONDUCTIVITY BEING LESS THAN 10**13 OHM/CM, CONTACTING SAID COATED SCREEN IN THE ABSENCE OF LIGHT WITH A MEMBER HAVING AN ELECTROSTATOGRAPHIC LATENT IMAGE SEPARATING THE MEMBERS WHEREBY LIQUID IS REMOVED FROM THE SCREEN BY ELECTROSTATIC ATTRACTION IN THE CHARGED AREAS OF THE IMAGE TO PROVIDE VOIDS IN IMAGE CONFIGURATION AND HARDENING THE LIQUID IN THE NONCHARGED AREAS TO FORM AN IMAGED STENCIL.
2. The process of claim 1 wherein the voids of the screen are coated with a silicone.
3. The process of claim 1 wherein the image on the image member is xerographically formed by charging a photoconductive layer and exposing said layer to imagewise light to form an electrostatographic latent image.
4. The process of claim 1 wherein the image member comprises zinc oxide photoreceptive paper.
5. The process of claim 1 wherein the screen is a metal screen.
6. The process of claim 1 wherein the screen is formed of stainless steel.
7. The process of claim 1 wherein the screen has a mesh size of from 60 to 325 U.S. mesh.
8. The process of claim 1 wherein the screen has a mesh size of from 100 to 250 U.S. mesh.
9. A method of printing comprising providing a suitable screen, coating the voids of said screen with a liquid material hardenable at ambient or elevated temperature which is impervious to a printing fluid and not dissolvable by said printing fluid and which has a viscosity and conductivity sufficient to permit removal by electrostatic attraction, said conductivity being less than 1013 ohm/cm, contacting said coated screen in the absence of light with a member having an electrostatographic latent image, separating the members whereby the liquid is removed from the screen by electrostatic attraction in the charged areas of the image to provide voids in image configuration and hardening the liquid in the nonimaged areas to form an imaged stencil, contacting the resultant stencil with an image receiving member and passing ink through said voids to thereby form an inked image on said receiving member.
10. The method of claim 1 wherein the screen is coated with the liquid material, and doctored with a flexible blade to remove the liquid from the contact plane so that when the screen is contacted with and separated from the image member, the liquid is removed from the screen only by electrostatic attraction.
11. The method of claim 1 wherein the electrostatographic latent image member contains an image which is negative in sense and the screen is biased to a potential which is approximately the same as those areas of the image member which are of the higher potential so that when the members are contacted and separated, an image is provided which is positive in sense.
12. The method of claim 9 wherein the screen is coated with the liquid material, and doctored with a flexible blade to remove the liquid from the contact plane so that when the screen is contacted with and separated from the image member, the liquid is removed from the screen only by electrostatic attraction.
US427591A 1973-12-26 1973-12-26 Electrostatographic process for preparing screen printing member Expired - Lifetime US3909256A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US427591A US3909256A (en) 1973-12-26 1973-12-26 Electrostatographic process for preparing screen printing member
DE19742456316 DE2456316A1 (en) 1973-12-26 1974-11-28 METHOD OF MANUFACTURING A PRINTED PART
JP14627074A JPS5096306A (en) 1973-12-26 1974-12-19
FR7442921A FR2256447A1 (en) 1973-12-26 1974-12-26 Xerographically produced printing plate - for use in relief or screen printing partic. of short runs
NL7416963A NL7416963A (en) 1973-12-26 1974-12-27 METHOD FOR MAKING PRINTING FORMS.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US427591A US3909256A (en) 1973-12-26 1973-12-26 Electrostatographic process for preparing screen printing member

Publications (1)

Publication Number Publication Date
US3909256A true US3909256A (en) 1975-09-30

Family

ID=23695499

Family Applications (1)

Application Number Title Priority Date Filing Date
US427591A Expired - Lifetime US3909256A (en) 1973-12-26 1973-12-26 Electrostatographic process for preparing screen printing member

Country Status (1)

Country Link
US (1) US3909256A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4078488A (en) * 1975-07-26 1978-03-14 Engineering Components Limited Method of preparing a printing screen by molding
US4550660A (en) * 1982-10-08 1985-11-05 Pilot Man-Nen-Hisu Kabushiki Kaisha Stencil
US5511477A (en) * 1993-09-03 1996-04-30 Idanit Technologies, Ltd Method and apparatus for the production of photopolymeric relief printing plates
US20070151118A1 (en) * 2005-12-22 2007-07-05 Luciano Perego Device for radiation drying

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2408144A (en) * 1944-01-15 1946-09-24 William C Hucbner Means for printing
US2949849A (en) * 1955-07-27 1960-08-23 Haloid Xerox Inc Stencil master making
US2949848A (en) * 1955-07-27 1960-08-23 Haloid Xerox Inc Stencil making
US3445226A (en) * 1965-05-24 1969-05-20 Xerox Corp Frost gravure print master
US3559570A (en) * 1966-07-20 1971-02-02 Xerox Corp Method of preparing and using a gravure printing plate
US3561358A (en) * 1966-10-10 1971-02-09 Xerox Corp Gravure imaging system
US3589289A (en) * 1966-12-22 1971-06-29 Burroughs Corp Printing members and methods for graphic composition
US3676215A (en) * 1968-04-26 1972-07-11 Xerox Corp Imaging system
US3687072A (en) * 1969-03-12 1972-08-29 Masson Scott Thrissell Eng Ltd Electrostatic copying
US3795530A (en) * 1968-04-26 1974-03-05 Xerox Corp Electrostatic latent image development
US3801315A (en) * 1971-12-27 1974-04-02 Xerox Corp Gravure imaging system
US3806354A (en) * 1969-07-01 1974-04-23 Xerox Corp Method of cyclically developing electrostatic latent images

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2408144A (en) * 1944-01-15 1946-09-24 William C Hucbner Means for printing
US2949849A (en) * 1955-07-27 1960-08-23 Haloid Xerox Inc Stencil master making
US2949848A (en) * 1955-07-27 1960-08-23 Haloid Xerox Inc Stencil making
US3445226A (en) * 1965-05-24 1969-05-20 Xerox Corp Frost gravure print master
US3559570A (en) * 1966-07-20 1971-02-02 Xerox Corp Method of preparing and using a gravure printing plate
US3561358A (en) * 1966-10-10 1971-02-09 Xerox Corp Gravure imaging system
US3589289A (en) * 1966-12-22 1971-06-29 Burroughs Corp Printing members and methods for graphic composition
US3676215A (en) * 1968-04-26 1972-07-11 Xerox Corp Imaging system
US3795530A (en) * 1968-04-26 1974-03-05 Xerox Corp Electrostatic latent image development
US3687072A (en) * 1969-03-12 1972-08-29 Masson Scott Thrissell Eng Ltd Electrostatic copying
US3806354A (en) * 1969-07-01 1974-04-23 Xerox Corp Method of cyclically developing electrostatic latent images
US3801315A (en) * 1971-12-27 1974-04-02 Xerox Corp Gravure imaging system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4078488A (en) * 1975-07-26 1978-03-14 Engineering Components Limited Method of preparing a printing screen by molding
US4550660A (en) * 1982-10-08 1985-11-05 Pilot Man-Nen-Hisu Kabushiki Kaisha Stencil
US5511477A (en) * 1993-09-03 1996-04-30 Idanit Technologies, Ltd Method and apparatus for the production of photopolymeric relief printing plates
US20070151118A1 (en) * 2005-12-22 2007-07-05 Luciano Perego Device for radiation drying

Similar Documents

Publication Publication Date Title
US3559570A (en) Method of preparing and using a gravure printing plate
US3547627A (en) Lithographic printing master and method employing a crystalline photoconductive imaging layer
US4883731A (en) Imaging system
US3561358A (en) Gravure imaging system
US3869285A (en) Plate-making master and method for producing a printing plate which does not require dampening water
US3207601A (en) Methods of preparing etch resists using an electrostatic image developer composition including a resin hardener
US3311490A (en) Developing electrostatic charge image with a liquid developer of two immiscible phases
US3909256A (en) Electrostatographic process for preparing screen printing member
US3104169A (en) Production of printing blocks, resists, transparencies, prints and the like by electro-deposition
US5011758A (en) Use of a liquid electrophotographic toner with an overcoated permanent master in electrostatic transfer
DE69010638T2 (en) Xero printing process.
US3145655A (en) Equipotential xeroprinting member and process of printing therewith
US4088073A (en) Process for preparing ink releasing stencil
US3794539A (en) Manufacture of electrophotographic plates
US3251688A (en) Liquid transfer development
EP0019068B1 (en) Charge receptor film for charge transfer imaging
US3256197A (en) Liquid developer for electrostatic charge images
US3948655A (en) Electrostatographic process for preparing gravure printing member
US4348469A (en) Photo-sensitive medium for electrophotography
US6132922A (en) Liquid developer for electrophotographic printing apparatus
US3684506A (en) Dimeric poly-n-vinyl carbazole organic photoconductor and photoconductive elements embodying same
US2956875A (en) Electrophotographic process for making stencil screens
EP0077220B1 (en) Graphic arts film and method of preparing same
US3322048A (en) Electrophotography
US3573040A (en) Heat desensitizing of convertible plate