EP0379673A2 - Electroerosion recording medium of improved corrosion resistance - Google Patents
Electroerosion recording medium of improved corrosion resistance Download PDFInfo
- Publication number
- EP0379673A2 EP0379673A2 EP89121803A EP89121803A EP0379673A2 EP 0379673 A2 EP0379673 A2 EP 0379673A2 EP 89121803 A EP89121803 A EP 89121803A EP 89121803 A EP89121803 A EP 89121803A EP 0379673 A2 EP0379673 A2 EP 0379673A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- layer
- conductive
- electroerosion
- aluminum
- conductive layer
- 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.)
- Granted
Links
Images
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
- B41M5/24—Ablative recording, e.g. by burning marks; Spark recording
- B41M5/245—Electroerosion or spark recording
Definitions
- the invention relates to electroerosion printing and to recording materials characterized by an improved hydrophilic, conductive or resistive lubricant topcoat, especially for use in the production of direct offset masters or direct negative applications.
- Electroerosion printing is a well-known technique for producing markings, such as, letters, numbers, symbols, patterns, such as, circuit patterns, or other legible or coded indicia on recording material in response to an electric signal which removes or erodes material from the surface of the recording material as the result of spark initiation.
- the surface which is eroded or removed to provide such indicia on the recording material is usually a thin film of conductive material which is vaporized in response to localized heating associated with sparking (arcing) initiated by applying an electric current to an electrode in contact with the surface of a recording material comprising the thin conductive film on a flexible nonconductive backing or support.
- the thin conductive film is usually a thin film of vaporizable metal, such as, aluminum.
- Electroerosion printing is effected by the movement of a stylus or a plurality of styli relative to the surface of specially prepared recording media. Electrical writing signals are fed to the stylus to provide controlled electrical pulses which generate sparks at the surface of the recording material to selectively heat and remove by evaporation a layer of the recording material; the locations from which material is removed correspond to the indicia or images which are to be recorded.
- the stylus is moved relatively to a surface of the recording material and in contact with the removable layer, e.g., a thin film of vaporizable material, usually a metal, such as aluminum.
- the removable layer e.g., a thin film of vaporizable material, usually a metal, such as aluminum.
- U.S. Patent 4,622,262 describes the use of graphite dispersed in a water insoluble polymeric binder, for example, ethyl cellulose. Although the corrosion resistance of the film is very good, the material cannot readily be used as direct offset plate because the surface of the material is hydrophobic and the top coat can not be easily removed from the surface.
- U.S. Patent 4,617,579 describes the use of a hydrophilic-water soluble binder (hydroxy ethyl cellulose or the like) in the top coat.
- a hydrophilic-water soluble binder hydroxy ethyl cellulose or the like
- DNP direct negative/direct plate
- U.S. Patent 4,567,490 describes the use of fluorinated graphite and Teflon with or without addition of graphite. Although the corrosion resistance of DNP materials coated with these fluorinated compounds increases due to their low conductivity, the print quality is poor.
- improved electroerosion recording materials can be prepared by providing the aluminum surface of such materials with a protective layer of solid conductive lubricant dispersed in a water insoluble hydrophilic crosslinked polymer matrix.
- the recording medium according to this invention provides use as a defect-free "direct negative” and/or “direct offset printing master” and thus has the advantage of process simplification by eliminating the need for removal of the overlayer after electroerosion recording and prior to use on the printing press as commonly practiced with conventional recording media.
- a further advantage of the unique protective coatings described herein is realized from application using aqueous dispersions of polymer- particulate compositions and thus avoiding the use of organic solvents.
- the conductive solid lubricant may be selected from the various conductive particulate lubricants disclosed in U.S. 4,622,262.
- the overlayer disclosed herein can be applied directly to the surface of electroerosion recording materials.
- One object of the invention is to produce electroerosion recording materials of improved resistance to stylus scratching by use of the special lubricating coatings of this invention.
- Another object is to provide an abrasion-resistant recording material suitable for generation of a high quality "direct negative” which also functions as a “direct offset printing master” with no extra step involved after electroerosion recording.
- Another object of the invention is to provide a superior lubricant composition which can also exhibit improved contrast when used to produce direct-negatives by electroerosion printing.
- a dark graphite/polymer film serves to help block light that may be partially transmitted through the thin conductive film, e.g., a thin aluminum film.
- a further object of the present invention is to provide a lubricant composition which does not have to be removed in the production of offset masters.
- Another object of this invention is to provide a superior lubricant composition which has improved corrosion resistance to fingerprinting or storage in a humid environment.
- Yet another object is to provide improved electroerosion recording material having a thin, uniform, and adherent overcoat for the aluminum film for protection against damage during storage and handling.
- the present invention generally comprises electroerosion recording materials consisting of a flexible support preferably with an abrasion-resistant, ink-receptive layer of polymer-particulate compositions, and an electroerodible metal film such as Al with a protective coating comprising lubricating particles of good electric conductivity in special types of organic polymeric binders.
- Electroerosion materials for use as direct-negatives or direct masters can be prepared utilizing this invention.
- the lubricating layer should have a density between about 2 and 30 micrograms per square centimeter since lower concentrations give inadequate lubrication and higher concentrations are too thick for good writing at low writing voltages (about 50 V) and short pulse lengths (about 3 microseconds). If more energy is applied by increasing the voltage of the writing pulse and increasing the pulse length, thicker films can be used.
- the lubricating agent binder ratio should be adjusted to avoid flake-off of the lubricating agent.
- conductive laminar solids may be used as the particulate conductive lubricant agent for the protective layer.
- Preferred materials are concentrated aqueous colloidal suspension of graphite/purified carbon with average particle size less than 1 micron available from Superior Graphite Co., Acheson Colloid Co., or similar products from Graphite Product Corp.
- materials which are expected to be useful include, for example, carbon black of mean particle diameter 0.02 ⁇ , solids such as ZnO, TiO2, MoS2, WS2, VSe2, TaSe2, CdS, Sb2O3 and TaS2; other soft 25 compounds such as AgI, PbO, Pb(OH)2, MoO, ZnI2, and PbCO3; and soft metal particles such as Sn, Cu, Ag, Pb, Au, Bi, Zn, Al, etc.
- solids such as ZnO, TiO2, MoS2, WS2, VSe2, TaSe2, CdS, Sb2O3 and TaS2
- other soft 25 compounds such as AgI, PbO, Pb(OH)2, MoO, ZnI2, and PbCO3
- soft metal particles such as Sn, Cu, Ag, Pb, Au, Bi, Zn, Al, etc.
- a typical structure comprises a flexible support such as polyethylene terephthalate (Mylar) with an abrasion-resistant base layer of polymer-particulate matrix which is preferably cross-linked, a thin conductive electroerodible film such as Al and a protective overlayer consisting of solid lubricants dispersed in a hydrophobic polymer matrix.
- a flexible support such as polyethylene terephthalate (Mylar) with an abrasion-resistant base layer of polymer-particulate matrix which is preferably cross-linked, a thin conductive electroerodible film such as Al and a protective overlayer consisting of solid lubricants dispersed in a hydrophobic polymer matrix.
- the lubricating top coat of this invention consists of a solid lubricant and a polymeric binder that glues the solid lubricant to the aluminum film so that it can not be easily removed either by hand or in the printer. Because electroerosion printing requires that electric current be passed from the printer head (array of 32 tungsten electrodes) to the aluminum film, the solid lubricant on the material has to be somewhat conductive and that is the reason that graphite or a mixture of graphite (conductive) and Teflon (non-conductive) is used as solid lubricant. The reason for lubricant is to reduce scratching (some times referred to as burnishing) of the aluminum film in the electroerosion process.
- the binder in the top coat which is used to glue the lubricant to aluminum plays an important role in the wettability of the materials.
- the surface of the material In order to be able to use the material as direct offset plate, the surface of the material must be hydrophilic.
- the water soluble cellulosic (hydroxy ethyl cellulose) materials make the aluminum surface much more susceptible to corrosion by finger prints or humidity of the environment. But if the binder is chosen from water insoluble polymeric materials (like ethyl cellulose), which reduces the chances of the corrosion of the aluminum film, the materials cannot be used as direct plate.
- This invention des strictlycribes choice of a water soluble-hydrophilic binder which after partial crosslinking with potassium dichromate becomes water insoluble (while maintaining its hydrophilicity) and which can be removed easily by conventional etchants, and therefore increases the corrosion resistance of the materials at the same time it retains its dual application as direct negative and direct plate. Furthermore, this invention describes the reaction of dichromate with aluminum film which makes a conversion layer on top of the aluminum which results in significant reduction of scratching (burnishing).
- FIG. 1 illustrates schematically an electroerosion printing system 1 which includes a source of electrical energy 2, which is connected with writing control means 3 for controlling the flow (voltage and pulse length) of electrical current to styli 4 which are electrodes which contact the surface of the electroerosion recording material 5.
- Means are provided for moving the styli 4 relative to and in contact with the surface of the recording material 5.
- the styli 4 move relative to the recording material 5 and the writing control means 3 direct pulses of current to the styli of sufficient voltage to cause arcing and evaporation of a conductive layer of the material, there can be recorded desired information, patterns and graphics of any kind. It is during the movement of the styli over and in contact with the surface of the recording material that the thin film on the surface of the recording 15 material is liable to be scratched and abraded resulting in poor writing quality and perhaps the recording of erroneous information.
- the electroerosion recording material of this invention 6 is shown in cross-section to comprise a support 7 of paper, polymer film, etc., a thin, conductive, evaporable layer or film 8, and a lubricant layer or film 9; optionally a tough, hard, transparent film 10 may be positioned between the support 7 and the evaporable layer 8.
- This intermediate film 10 preferably is of a layer of small hard particles in a suitable polymeric binder, for example, silica particles in a cellulose-acetate-butyrate (CAB) polymeric binder, or silica particles in a cross-linked polymer such as urethane cross-linked CAB, which may be light transmissive or transparent, to further reduce scratching of the material during electroerosion printing.
- a suitable polymeric binder for example, silica particles in a cellulose-acetate-butyrate (CAB) polymeric binder, or silica particles in a cross-linked polymer such as urethane cross-linked CAB, which may be light transmissive or transparent, to further reduce scratching of the material during electroerosion printing.
- the evaporable film 8 usually has a resistance from about 1 to 5 ohms per square centimeter and is frequently a vapor-deposited thin film of aluminum.
- the resulting product can be used as a photomask or direct negative medium for the development of photosensitive materials, e.g., in the production of offset lithography masters, circuit boards, etc.
- the recording material is preferably to be used as an offset master where the support is chosen to be an ink receptive material such as polyester. After imaging by electroerosion printing to expose the support layer selectively, the overlayer lubricating composition does not have to be removed, as illustrated by Fig. 2.
- Electroerosion recording materials of the invention may be prepared in accordance with the following procedure:
- a flexible sheet of Mylar polyester 50 micrometers thick was provided.
- a coating of silica particles in a urethane cross-linked CAB binder was put down.
- this layer there was evaporation deposited, by conventional technique, a thin conductive film of aluminum, about 40 nm thick. This type of structure was used in the Examples hereinbelow, onto which the protective lubricating films were coated.
- the DNP materials were coated with a 1% solid of the above mixture to a thickness of 2-10 microgram/square centimeter and dried at 80-110° C for about 0.5-1.0 minutes.
- the top coated materials were then treated with 0.1-1.0% aqueous solution of potassium dichromate and dried at 100° C for 30 seconds.
- the resulting materials were water insoluble but also had a water wettable surface which could be used as direct plate.
- the corrosion resistance of the latter was increased 20-50 times compared with that of standard DNP.
- the burnishing and scratching of the material is reduced by a factor of three to four over that of a film not treated with dichromate.
- potassium dichromate solution is the preferred reagent for crosslinking of Gantrez S-95
- inorganic reagents which are capable of doing the same.
- aqueous solutions of aluminum salts aluminum acetate and nitrate were also tried successfully to crosslink the Gantrez and produce a water insoluble and water wettable surface.
Landscapes
- Manufacture Or Reproduction Of Printing Formes (AREA)
- Printing Plates And Materials Therefor (AREA)
- Paints Or Removers (AREA)
- Lubricants (AREA)
Abstract
Description
- The invention relates to electroerosion printing and to recording materials characterized by an improved hydrophilic, conductive or resistive lubricant topcoat, especially for use in the production of direct offset masters or direct negative applications.
- Electroerosion printing is a well-known technique for producing markings, such as, letters, numbers, symbols, patterns, such as, circuit patterns, or other legible or coded indicia on recording material in response to an electric signal which removes or erodes material from the surface of the recording material as the result of spark initiation.
- The surface which is eroded or removed to provide such indicia on the recording material is usually a thin film of conductive material which is vaporized in response to localized heating associated with sparking (arcing) initiated by applying an electric current to an electrode in contact with the surface of a recording material comprising the thin conductive film on a flexible nonconductive backing or support. In the present state of the technology the thin conductive film is usually a thin film of vaporizable metal, such as, aluminum.
- Electroerosion printing is effected by the movement of a stylus or a plurality of styli relative to the surface of specially prepared recording media. Electrical writing signals are fed to the stylus to provide controlled electrical pulses which generate sparks at the surface of the recording material to selectively heat and remove by evaporation a layer of the recording material; the locations from which material is removed correspond to the indicia or images which are to be recorded.
- In the course of this process, the stylus is moved relatively to a surface of the recording material and in contact with the removable layer, e.g., a thin film of vaporizable material, usually a metal, such as aluminum.
- Due to the fragility of the thin conductive layer and stylus pressure, considerable scratching (undesired removal of the removable layer) is observed to take place during electroerosion printing.
- It has been recognized for some time, therefore, that the use of a lubricant and/or protective overcoat on the surface of such electroerosion recording materials would be helpful to reduce scratching by the stylus. After some investigation, lubricants comprising long chain fatty acids were adopted. Even with the use of such lubricants, however, some stylus scratching of the thin aluminum film of electroerosion recording materials continues to be observed. Therefore, efforts continued to be directed to finding a superior lubricant-protective layer composition for the surface of electroerosion recording materials.
- U.S. Patent 4,622,262 describes the use of graphite dispersed in a water insoluble polymeric binder, for example, ethyl cellulose. Although the corrosion resistance of the film is very good, the material cannot readily be used as direct offset plate because the surface of the material is hydrophobic and the top coat can not be easily removed from the surface.
- U.S. Patent 4,617,579 describes the use of a hydrophilic-water soluble binder (hydroxy ethyl cellulose or the like) in the top coat. In this case although the material can be used both as negative and plate, because of the conductivity, hydrophilicity and water solubility of the top coat, it undergoes rapid corrosion of the aluminum film from fingerprinting and in humid environments. Therefore, after handling or short storage times it could not reliably be used as direct negative/direct plate (DNP).
- U.S. Patent 4,567,490 describes the use of fluorinated graphite and Teflon with or without addition of graphite. Although the corrosion resistance of DNP materials coated with these fluorinated compounds increases due to their low conductivity, the print quality is poor.
- It has been found that improved electroerosion recording materials can be prepared by providing the aluminum surface of such materials with a protective layer of solid conductive lubricant dispersed in a water insoluble hydrophilic crosslinked polymer matrix.
- The recording medium according to this invention provides use as a defect-free "direct negative" and/or "direct offset printing master" and thus has the advantage of process simplification by eliminating the need for removal of the overlayer after electroerosion recording and prior to use on the printing press as commonly practiced with conventional recording media. A further advantage of the unique protective coatings described herein is realized from application using aqueous dispersions of polymer- particulate compositions and thus avoiding the use of organic solvents.
- The conductive solid lubricant may be selected from the various conductive particulate lubricants disclosed in U.S. 4,622,262.
- The overlayer disclosed herein can be applied directly to the surface of electroerosion recording materials.
- One object of the invention, therefore, is to produce electroerosion recording materials of improved resistance to stylus scratching by use of the special lubricating coatings of this invention.
- Another object is to provide an abrasion-resistant recording material suitable for generation of a high quality "direct negative" which also functions as a "direct offset printing master" with no extra step involved after electroerosion recording.
- Another object of the invention is to provide a superior lubricant composition which can also exhibit improved contrast when used to produce direct-negatives by electroerosion printing. In such usage a dark graphite/polymer film serves to help block light that may be partially transmitted through the thin conductive film, e.g., a thin aluminum film. A further object of the present invention is to provide a lubricant composition which does not have to be removed in the production of offset masters.
- Another object of this invention is to provide a superior lubricant composition which has improved corrosion resistance to fingerprinting or storage in a humid environment.
- Yet another object is to provide improved electroerosion recording material having a thin, uniform, and adherent overcoat for the aluminum film for protection against damage during storage and handling.
- Fig. 1 of the drawings is a general schematic rendering of an illustrative electroerosion operation.
- Fig. 2 of the drawings is a cross-sectional view of a direct offset master made in accordance with the invention and showing the removal of surface layers in regions where electroerosion has been effected.
- The present invention generally comprises electroerosion recording materials consisting of a flexible support preferably with an abrasion-resistant, ink-receptive layer of polymer-particulate compositions, and an electroerodible metal film such as Al with a protective coating comprising lubricating particles of good electric conductivity in special types of organic polymeric binders. Electroerosion materials for use as direct-negatives or direct masters can be prepared utilizing this invention. In general, the lubricating layer should have a density between about 2 and 30 micrograms per square centimeter since lower concentrations give inadequate lubrication and higher concentrations are too thick for good writing at low writing voltages (about 50 V) and short pulse lengths (about 3 microseconds). If more energy is applied by increasing the voltage of the writing pulse and increasing the pulse length, thicker films can be used. Also the lubricating agent binder ratio should be adjusted to avoid flake-off of the lubricating agent.
- Many conductive laminar solids may be used as the particulate conductive lubricant agent for the protective layer. Preferred materials are concentrated aqueous colloidal suspension of graphite/purified carbon with average particle size less than 1 micron available from Superior Graphite Co., Acheson Colloid Co., or similar products from Graphite Product Corp. Other materials which are expected to be useful include, for example, carbon black of mean particle diameter 0.02µ, solids such as ZnO, TiO₂, MoS₂, WS₂, VSe₂, TaSe₂, CdS, Sb₂O₃ and TaS₂; other soft 25 compounds such as AgI, PbO, Pb(OH)₂, MoO, ZnI₂, and PbCO₃; and soft metal particles such as Sn, Cu, Ag, Pb, Au, Bi, Zn, Al, etc.
- A typical structure comprises a flexible support such as polyethylene terephthalate (Mylar) with an abrasion-resistant base layer of polymer-particulate matrix which is preferably cross-linked, a thin conductive electroerodible film such as Al and a protective overlayer consisting of solid lubricants dispersed in a hydrophobic polymer matrix.
- The lubricating top coat of this invention consists of a solid lubricant and a polymeric binder that glues the solid lubricant to the aluminum film so that it can not be easily removed either by hand or in the printer. Because electroerosion printing requires that electric current be passed from the printer head (array of 32 tungsten electrodes) to the aluminum film, the solid lubricant on the material has to be somewhat conductive and that is the reason that graphite or a mixture of graphite (conductive) and Teflon (non-conductive) is used as solid lubricant. The reason for lubricant is to reduce scratching (some times referred to as burnishing) of the aluminum film in the electroerosion process. The binder in the top coat which is used to glue the lubricant to aluminum plays an important role in the wettability of the materials. In order to be able to use the material as direct offset plate, the surface of the material must be hydrophilic. The water soluble cellulosic (hydroxy ethyl cellulose) materials make the aluminum surface much more susceptible to corrosion by finger prints or humidity of the environment. But if the binder is chosen from water insoluble polymeric materials (like ethyl cellulose), which reduces the chances of the corrosion of the aluminum film, the materials cannot be used as direct plate. This invention describes choice of a water soluble-hydrophilic binder which after partial crosslinking with potassium dichromate becomes water insoluble (while maintaining its hydrophilicity) and which can be removed easily by conventional etchants, and therefore increases the corrosion resistance of the materials at the same time it retains its dual application as direct negative and direct plate. Furthermore, this invention describes the reaction of dichromate with aluminum film which makes a conversion layer on top of the aluminum which results in significant reduction of scratching (burnishing).
- The detailed description of the invention can be better appreciated by reference to the accompanying drawings. Fig. 1 illustrates schematically an electroerosion printing system 1 which includes a source of electrical energy 2, which is connected with writing control means 3 for controlling the flow (voltage and pulse length) of electrical current to
styli 4 which are electrodes which contact the surface of theelectroerosion recording material 5. - In operation, electric current pulses corresponding to information to be printed on the
recording material 5 are transmitted through thewriting control systems 3 to thestyli 4. As a result, electrical discharges are generated at the surface of therecording material 5, and the temperature of the thin surface film is locally raised causing evaporation of the surface film or layer and the underlying material is exposed to produce the desired image. - Means (not shown) are provided for moving the
styli 4 relative to and in contact with the surface of therecording material 5. As thestyli 4 move relative to therecording material 5 and the writing control means 3 direct pulses of current to the styli of sufficient voltage to cause arcing and evaporation of a conductive layer of the material, there can be recorded desired information, patterns and graphics of any kind. It is during the movement of the styli over and in contact with the surface of the recording material that the thin film on the surface of the recording 15 material is liable to be scratched and abraded resulting in poor writing quality and perhaps the recording of erroneous information. - Referring to Fig. 2, the electroerosion recording material of this
invention 6 is shown in cross-section to comprise a support 7 of paper, polymer film, etc., a thin, conductive, evaporable layer or film 8, and a lubricant layer orfilm 9; optionally a tough, hard,transparent film 10 may be positioned between the support 7 and the evaporable layer 8. Thisintermediate film 10 preferably is of a layer of small hard particles in a suitable polymeric binder, for example, silica particles in a cellulose-acetate-butyrate (CAB) polymeric binder, or silica particles in a cross-linked polymer such as urethane cross-linked CAB, which may be light transmissive or transparent, to further reduce scratching of the material during electroerosion printing. The evaporable film 8 usually has a resistance from about 1 to 5 ohms per square centimeter and is frequently a vapor-deposited thin film of aluminum. - Where the backing or support is a light transparent or transmissive material, the resulting product can be used as a photomask or direct negative medium for the development of photosensitive materials, e.g., in the production of offset lithography masters, circuit boards, etc.
- The recording material is preferably to be used as an offset master where the support is chosen to be an ink receptive material such as polyester. After imaging by electroerosion printing to expose the support layer selectively, the overlayer lubricating composition does not have to be removed, as illustrated by Fig. 2.
- Electroerosion recording materials of the invention may be prepared in accordance with the following procedure:
- As a support, a flexible sheet of Mylar polyester 50 micrometers thick was provided. On this support, using conventional web-coating apparatus, a coating of silica particles in a urethane cross-linked CAB binder was put down. Onto this layer there was evaporation deposited, by conventional technique, a thin conductive film of aluminum, about 40 nm thick. This type of structure was used in the Examples hereinbelow, onto which the protective lubricating films were coated.
- The following working examples are described to illustrate the best mode of carrying out this invention to provide an improved recording medium and generation of a "direct offset master" and/or a "direct negative". A unique feature of this material is provided by the lubricant overlayer on the aluminum surface which is effective in preventing mechanical abrasion of the conductive film during electroerosion recording and which need not be removed prior to use of the material as an offset printing master.
- A mixture of 2.5 g polyvinylmethyl ether maleic acid (Gantrez S-95, GAF Co.) with 7.0 g graphite particles and 0.50 g surfactant in 990 g of water was stirred to disperse the graphite. The DNP materials were coated with a 1% solid of the above mixture to a thickness of 2-10 microgram/square centimeter and dried at 80-110° C for about 0.5-1.0 minutes. The top coated materials were then treated with 0.1-1.0% aqueous solution of potassium dichromate and dried at 100° C for 30 seconds. The resulting materials were water insoluble but also had a water wettable surface which could be used as direct plate. The corrosion resistance of the latter was increased 20-50 times compared with that of standard DNP.
- Also, due to the formation of a conversion layer, the burnishing and scratching of the material is reduced by a factor of three to four over that of a film not treated with dichromate.
- In another experiment 40.0 g Graphite (ElectroDag 191, Acheson Industries) was mixed with 2.2 g of water dispersed Teflon (Teflon 30, DuPont Co.) and 2.7 g Gantrez S-95 in 1050 g of H₂O and coated on DNP materials and after drying it was treated with 0.1-1.0% aqueous potassium dichromate to give the water insoluble water wettable surface which had even better corrosion resistance than the previous Example.
- Although potassium dichromate solution is the preferred reagent for crosslinking of Gantrez S-95, there are other inorganic reagents which are capable of doing the same. As an example, aqueous solutions of aluminum salts (aluminum acetate and nitrate) were also tried successfully to crosslink the Gantrez and produce a water insoluble and water wettable surface.
Claims (12)
a non-conductive support layer;
a thin conductive layer on said support layer, said conductive layer capable of being removed in selected areas thereof by an electroerosion recording process; and
an overlayer of a protective lubricant composition on the recording surface of said thin conductive layer, said lubricant composition comprising conductive particles of high lubricity dispersed in a partially crosslinked, water insoluble, hydrophilic polymeric binder.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US30066589A | 1989-01-23 | 1989-01-23 | |
US300665 | 1994-09-02 |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0379673A2 true EP0379673A2 (en) | 1990-08-01 |
EP0379673A3 EP0379673A3 (en) | 1990-09-19 |
EP0379673B1 EP0379673B1 (en) | 1994-04-13 |
Family
ID=23160085
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19890121803 Expired - Lifetime EP0379673B1 (en) | 1989-01-23 | 1989-11-25 | Electroerosion recording medium of improved corrosion resistance |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0379673B1 (en) |
JP (1) | JPH0761709B2 (en) |
DE (1) | DE68914634T2 (en) |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4339758A (en) * | 1981-05-15 | 1982-07-13 | Dennison Manufacturing Company | Electrosensitive recording |
EP0147624A2 (en) * | 1983-12-30 | 1985-07-10 | International Business Machines Corporation | Method for making direct negatives and direct masters by electroerosion recording |
EP0147641A2 (en) * | 1983-12-30 | 1985-07-10 | International Business Machines Corporation | Recording materials for use in electroerosion printing |
EP0147642A2 (en) * | 1983-12-30 | 1985-07-10 | International Business Machines Corporation | Electroerosion print media having a protective coating |
EP0147703A2 (en) * | 1983-12-30 | 1985-07-10 | International Business Machines Corporation | Improved electroerosion recording material with a protective lubricant overlayer |
EP0158276A2 (en) * | 1984-04-13 | 1985-10-16 | Lexmark International, Inc. | Electroerosion printing media |
US4617579A (en) * | 1984-04-05 | 1986-10-14 | International Business Machines Corporation | Hydrophilic protective coatings for electroerosion printing |
US4622262A (en) * | 1982-12-30 | 1986-11-11 | International Business Machines Corporation | Recording materials of improved lubricity for use in electroerosion printing |
-
1989
- 1989-11-25 EP EP19890121803 patent/EP0379673B1/en not_active Expired - Lifetime
- 1989-11-25 DE DE1989614634 patent/DE68914634T2/en not_active Expired - Fee Related
-
1990
- 1990-01-23 JP JP1199890A patent/JPH0761709B2/en not_active Expired - Lifetime
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4339758A (en) * | 1981-05-15 | 1982-07-13 | Dennison Manufacturing Company | Electrosensitive recording |
US4622262A (en) * | 1982-12-30 | 1986-11-11 | International Business Machines Corporation | Recording materials of improved lubricity for use in electroerosion printing |
EP0147624A2 (en) * | 1983-12-30 | 1985-07-10 | International Business Machines Corporation | Method for making direct negatives and direct masters by electroerosion recording |
EP0147641A2 (en) * | 1983-12-30 | 1985-07-10 | International Business Machines Corporation | Recording materials for use in electroerosion printing |
EP0147642A2 (en) * | 1983-12-30 | 1985-07-10 | International Business Machines Corporation | Electroerosion print media having a protective coating |
EP0147703A2 (en) * | 1983-12-30 | 1985-07-10 | International Business Machines Corporation | Improved electroerosion recording material with a protective lubricant overlayer |
US4617579A (en) * | 1984-04-05 | 1986-10-14 | International Business Machines Corporation | Hydrophilic protective coatings for electroerosion printing |
EP0158276A2 (en) * | 1984-04-13 | 1985-10-16 | Lexmark International, Inc. | Electroerosion printing media |
Also Published As
Publication number | Publication date |
---|---|
DE68914634D1 (en) | 1994-05-19 |
JPH02258344A (en) | 1990-10-19 |
JPH0761709B2 (en) | 1995-07-05 |
EP0379673A3 (en) | 1990-09-19 |
EP0379673B1 (en) | 1994-04-13 |
DE68914634T2 (en) | 1994-11-17 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4911075A (en) | Lithographic plates made by spark discharges | |
CA1232135A (en) | Recording materials with new hydrophilic protective coatings for use in electroerosion printing | |
EP0147641B1 (en) | Recording materials for use in electroerosion printing | |
US5249525A (en) | Spark-discharge lithography plates containing image-support pigments | |
EP0147643B1 (en) | Electroerosion printing | |
US4086853A (en) | Lithographic printing plate preparation | |
US4622262A (en) | Recording materials of improved lubricity for use in electroerosion printing | |
US5084331A (en) | Electroerosion recording medium of improved corrosion resistance | |
EP0113007B1 (en) | Recording materials having a surface lubricant layer for use in electroerosion printing | |
JP2801777B2 (en) | Lithographic printing plate | |
US4894279A (en) | Electroerosion print media having protective coatings modified with organotitanium reagents | |
EP0379673B1 (en) | Electroerosion recording medium of improved corrosion resistance | |
CA1221832A (en) | Method for making direct negatives and direct masters by electroerosion recording and products formed thereby | |
EP0490051A1 (en) | Improved electroerosion printing plates | |
US4958563A (en) | Lithography plate with a chromium surface and method for imaging | |
EP0147642B1 (en) | Electroerosion print media having a protective coating | |
US5052292A (en) | Method and means for controlling overburn in spark-imaged lithography plates | |
US4947750A (en) | Printing member for a press with dampening | |
JPH04501833A (en) | Method and device for controlling overburning of spark image printing plates | |
US4958562A (en) | Printing member with an organic plastic surface and method for imaging | |
US4947749A (en) | Printing member for a press with dampening | |
Afzali et al. | Improved Materials for Fabrication of Direct Negatives and Plates by Electro-Erosion Printing. | |
JPH0560857B2 (en) | ||
JPH01115688A (en) | Electric discharge recording material | |
JP2005169966A (en) | Manufacturing method for planographic printing plate original plate, planographic printing plate original plate and printing method |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): DE FR GB |
|
PUAL | Search report despatched |
Free format text: ORIGINAL CODE: 0009013 |
|
AK | Designated contracting states |
Kind code of ref document: A3 Designated state(s): DE FR GB |
|
17P | Request for examination filed |
Effective date: 19901113 |
|
17Q | First examination report despatched |
Effective date: 19920813 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): DE FR GB |
|
REF | Corresponds to: |
Ref document number: 68914634 Country of ref document: DE Date of ref document: 19940519 |
|
ET | Fr: translation filed | ||
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed | ||
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 19951024 Year of fee payment: 7 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 19951107 Year of fee payment: 7 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 19951123 Year of fee payment: 7 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Effective date: 19961125 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 19961125 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Effective date: 19970731 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Effective date: 19970801 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |