US3151549A - Electrically inscribable lithographic masters - Google Patents

Electrically inscribable lithographic masters Download PDF

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Publication number
US3151549A
US3151549A US79250559A US3151549A US 3151549 A US3151549 A US 3151549A US 79250559 A US79250559 A US 79250559A US 3151549 A US3151549 A US 3151549A
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United States
Prior art keywords
coating
hydrophilic
base
conductive
paper
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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
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English (en)
Inventor
Raymond L Oransky
Robert L Stoddard
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Warren SD Co
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Warren SD Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to NL248212D priority Critical patent/NL248212A/xx
Priority to NL120974D priority patent/NL120974C/xx
Priority to BE586149D priority patent/BE586149A/xx
Application filed by Warren SD Co filed Critical Warren SD Co
Priority to US79250559 priority patent/US3151549A/en
Priority to GB4001259A priority patent/GB884504A/en
Priority to FR814173A priority patent/FR1246443A/fr
Priority to DEW26958A priority patent/DE1167365B/de
Application granted granted Critical
Publication of US3151549A publication Critical patent/US3151549A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
    • B41N1/00—Printing plates or foils; Materials therefor
    • B41N1/12—Printing plates or foils; Materials therefor non-metallic other than stone, e.g. printing plates or foils comprising inorganic materials in an organic matrix
    • B41N1/14—Lithographic printing foils
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
    • B41N3/00—Preparing for use and conserving printing surfaces
    • B41N3/03—Chemical or electrical pretreatment
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/31504—Composite [nonstructural laminate]
    • Y10T428/31855—Of addition polymer from unsaturated monomers
    • Y10T428/31859—Next to an aldehyde or ketone condensation product
    • Y10T428/3187—Amide-aldehyde
    • Y10T428/31873—Urea or modified urea-aldehyde

Definitions

  • Electrically inscribable recording papers are well known. They are'used, for instance, in the facsimile reception of messages or graphic intelligence such as telegrams, drawl ings, maps, pictures, and the like sent over facsimile communication systems. In such transmission an electrical signal generated as a result of the scanning of graphie message matter by a pick-up means at a recording station is transmitted to a receiving station where an electric stylus marks an electrosensitive blank of coated paper in a pattern corresponding to the original message.
  • a paper may comprise a paper base made electrically conductive by reason of a filling or coating of conductive carbon black or equivalent conductive material which usually imparts a distinct coloration to the paper base.
  • a thin layer of coating of contrasting color which is slightly conductive, but much less so than the base itself.
  • a coating containing cuprous thiocyanate powder in a resinous binder or adhesive has in the past been successfully used for such a top coat, being sufficiently conductive, opaque and white to give satisfactory results.
  • an electrical stylus' having a pointed tip moves across the surface of the blank in a series of closely spaced parallel paths.
  • a spark passes between the stylus and the conductive base, burning a hole in the top coating of low conductivity, and exposing the underlying conductive base.
  • the matter to be recorded on the blank is a dot like the dot of an i or if it is a narrow straight line which falls completely in the path of one sweep of the stylus, it may be recorded in a single burn by a single impulse impressed on the stylus.
  • a lithographie master bearing thereon an oleophilic image is wet by having rolled j across its surface a roller wet with aqueous lithographie solution usually made acidic by a content of phosphoric acid or acidic salt thereof. This wets thebackground areas but does not wet the oleophilic-image.
  • a roller inked with greasy lithographie printing ink isrolled across the surface. The ink adheres to the imaged areas but is repelled from the wet background areas.
  • the inked plate is then pressed against a rubber offset blanket to which the image is transferred in reverse.
  • -A paper sheet when pressed against the offset blanket takes off the print in its original form. The cycle is repeated as many times as there are copies desired, which may sometimes be l several hundred.
  • planographie printing is a branch of lithography in which the printing plate has a substantially plane surface with a printing image affixed to the surface.
  • image is actually etched into a metal plate, so that the image is recessed below the surface of the plate.
  • image formed is actually that portion of the underlyingv base which is exposed by removal ofthe top coating.
  • the image thus lies below the surface of the top coatingy and so resembles a deep-etch lithographie image rather than a planographic image.
  • the exposed underlying base must be oleophilic in character.
  • a suitable electrically conductive base for an electrically inseribable lithographie master can be readily provided by eoating a web of paper with a conductive layer of carbon black in an oleophilic resinous binder which has relatively low electrical resistivity.
  • the resultp ing conductive base is given atop coating of cuprous thiocyanate and insolubilized hydrophilic adhesive sufficiently thick completely to cover the conductive coating the product is adequate in accepting aqueous lithographie solution and repelling greasy printing ink.
  • the present invention provides a coated paper sheet which has excellent lithographie printing qualities and yet at the same time can be inscribed electrically with an image which is a faithful copy of the original and from which substantial duplicates can be reproduced by the lithographic printing process.
  • a sheet or web of paper is provided with a conductive layer of coating comprising a pigmentary component of powdered matter having good electrical conductivity, such as carbon black, bound to the paper surface by an oleophilic and water-resistant adhesive.
  • a conductive layer of coating comprising a pigmentary component of powdered matter having good electrical conductivity, such as carbon black, bound to the paper surface by an oleophilic and water-resistant adhesive.
  • an oleophilic and conductive coating is applied one or more than one layer of hydrophilic coating containing powdered cuprous thiocyanate or equivalent bound by insolubilized hydrophilic adhesive material.
  • Such hydrophilic layer or each of such layers has relatively high electrical resistivity and hence only slight electrical conductivity.
  • the tendency for the facsimile inscribing spark to wander on the surface of the hydrophilic coating can be substantially eliminated by incorporating in the surface of the hydrophilic coating a relatively small proportion of highly conductive powder such as carbon black or equivalent.
  • highly conductive powder such as carbon black or equivalent.
  • FIG. 1 is a diagrammatic cross-section of. a coated paper having two layers of coating
  • FIG. 2 is a diagrammatic cross-section of a coated paper having three layers of coating.
  • a suitable paper base to use for the purpose of the invention is any sized paper web of reasonably level surface having strength at least as great as that of a standard printing paper of about pound basis for a ream of 500 Sheets cut 25 x 38 inches in size.
  • a little wetstrength resin may be included in the paper-making furnish in the well known way.
  • wet-strength is not necessary, because usually only a few copies, e.g. less than 100, are desired to be printed from such an inscribed master.
  • a typical paper base-stock which has given satisfactory results in practicing the invention is a web of sized paper containing both long and short chemical wood fibers and a small quantity of clay filler and weighing about pounds per ream or about 75 grams per square meter.
  • the base paper is provided with a layer of conductive coating, suitably applied in the form of an aqueous dispcrsion by a conventional coating means, such as an airknife coater. Sufficient thickness of coating is applied to completely cover the paper base and give anadequately conductive layer. Usually about 6 pounds, dry weight, of coating per ream is adequate. A greater amount is an added safeguard, and a reasonable excess of weight is not objectionable in the conductive base coat. It has been found quite satisfactory to apply to one side of a suitable paper base by means of a conventional coating device,
  • an air-knife coater about 9 pounds per ream, dry weight, of an aqueous coating mixture having the following composition:
  • This coating is very similar to conductive coatings which have been commonly used in the past in ordinary facsimile papers, i.e. in facsimile papers not having lithographic printing surfaces. Any similar known conductive coating may be substituted therefor provided it is ymarkedly oleophilic -as well as substantially water-insoluble.
  • the various vinyl acetate copolymers in latex form seem especially well suited for this use.
  • the oleophilic conductive base-coat After the oleophilic conductive base-coat has been dried it preferably is smoothed by a calendering process. Thereafter a hydrophilic coating composition is applied over the base coat by means of any suitable coating device.
  • the hydrophilic coating having conductive particles in its surface must be thick enough completely to cover the very oleophilic base coat.
  • About 6 pounds dry weight of coating per ream is about as little as can safely be relied on to give complete coverage of the oleophilic base coat even if applied in two separate layers.
  • the said hydrophilic coating may comprise one layer, or more than one layer.
  • the top surface of the hydrophilic coating must contain particles of highly conductive powder.
  • the major portion of the hydrophilic coating consists essentially of cuprous thiocyanate powder or equivalent, suiicient hydrophilic binder or adhesive to bind the coating to the base, and an agent to insolubilize the adhesive. Any hydrophilic adhesive commonly used in paper coating will serve satisfactorily.
  • the insolubilizing agent should be one which does not destroy ythe hydrophilic properties of the adhesive but does render it substantially water-insoluble. Dimethylol urea and similar amino-aldehyde condensates are suitable and effective insolubilizing agents.
  • the oleophilic base coat is difficult to wet with aqueous medium it is advantageous to include in the hydrophilic coating composition an e'lcient wetting agent and/ or an adhesive possessing good wetting properties, such as casein or soy protein solvated by a basic solvent.
  • an e'lcient wetting agent and/ or an adhesive possessing good wetting properties such as casein or soy protein solvated by a basic solvent.
  • the preferred highly conductive particles are those of conductive carbon black, because of cost, fine division, and ease of handling. Other conductive powders can be substituted therefor, but must be free from insulating coatings of grease or oxide. Since the latter requirement poses some difficulties in the use of powdered metals of low cost, carbon black remains the preferred material in spite of its undesirable discoloring effect. Because of the darkening effect of the carbon black, as well as the effect which excessive quantities of carbon black have in too greatly decreasing resistivity, the latter should make up less than 10 percent of the pigment portion of the hydrophilic coating. If the carbon black is confined strictly to the top surface of the coating as little as l percent on the weight of total pigment may suffice. In most cases not over 6 percent of carbon black would be needed.
  • cuprous thiocyanate is preferred, as shown in U.S. Patent No. 2,681,309.
  • Other white pigments which decompose to darker compounds under the action of electric current may be substituted with somewhat comparable results, for example lead thiosulfate.
  • the coating composition was applied by means of an air-knife coating-machine in amount equivalent to about pounds, dry weight, per rearn.
  • the coating composition was according to the following formula in which all parts are parts by weight:
  • Parez 611 40 Iparts anhydrous zinc acetate 1 .part Tergitol 4, a wetting agent 1/2 part tributyl phosphate, an anti-foam agent Water to make solids content 30% Tergitol 4 is the trade-name of the sodium sulfate derivative of 7-ethyl-2 methyl undecanol-4.
  • the coated product was dried at elevated temperature to ensure insolubilization of the coating. It was then used without any final calendering treatment.
  • the sheet was inscribed by an electric stylus on a facsimile receiver, and the inscribed sheet was then used as a master or plate on a rotary offset duplicator. Over 200 copies were printed from the master, 4and the master at that Itime had not begun to show any evidence of deterioration. The copy was good and 8-point type was legible.
  • the color of the master above described was distinctly dark gray, in spite of the inclusion of some titanium dioxide in the formula to offset in part the darkening effect of Ithe carbon black.
  • the ⁇ formula as shown includes a quantity of zinc acetate. It is preferable, but not essential, to have zinc acetate or equivalent divalent metal salt present in the surface pores of the coating to improve the lithographie printing qualities of the master.
  • the beneficial effects of zinc acetate or equivalent soluble divalent metal salts in the surface pores and interstices of coated paper lithographie printing masters are well known.
  • a perfectly good and usable master can be made according to the present invention without any zinc acetate, but the use of that salt protects against accidental soiling of the master and in general permits greater latitude in operating conditions.
  • FIG. 1 The structure described above is illustrated in FIG. 1 in which 1 is the paper base, 2 is the oleophilic electrically conductive coating, and 3 is the single hydrophilic coating containing both the pigment which is sensitive to electric current and the electrically conductive pigment.
  • the interposition of a layer of substantially white hydrophilic coating between the colored oleophilic base and the very top layer containing conductive particles also substantially reduces show-through of the colored base so that hte color of t-he finished product is substantially unaffected yby the color of the olephilic base, but instead is due chiefly to ingredients of the top coating layer itself.
  • the topmost layer containing finely divided highly conductive particles and having a higher conductivity and lower resistivity than the lower layer or layers thereof.
  • the top layer can be of the same composition as that of the Formula for Single Layer Hydrophilic Coating shown above.
  • the under portion of the hydrophilic coating can be identical except for omission of the carbon black shown in that formula.
  • the hydrophilic coating is applied over -a suitable paper web having thereon a conductive oleophilic coating with a calendered surface.
  • the base-coated web was coated on the same vside by means of an air-knife coater with about 4 pounds per ream, dry weight, of the following composition:
  • the paper was then steamed lightly on the reverse side to offset the tendency to curl caused by the coating being on one side only, and was then wound up into a roll. After the top coating had been applied the paper was not given any further smoothing or calendering. The coated paper was not white but was definitely gray. When electrically inscribed the contrast between the gray top coat and the black base coat was adequate for good legibility. The inscribed image was of good regularity, and copies printed therefrom on an offset duplicator were excellent. More than 500 good copies were obtainable without evidence of deterioration in the master.
  • FIG. 2 The above-described structure is illustrated in FIG. 2 in which 1 is the paper base, 2 is the oleophilic electrically conductive coating, 4 is the hydrophilic coating containing pigment whcih is sensitive to electric current and 5 is the hydrophilic coating containing electrically conductive pigment.
  • the product of the invention is a coated paper electrically inscribable lithographie master or plate which can be used on a rotary offset duplicator to produce printed copies of matter electrically inscribed thereon. It cof-nprises a paper base having thereon a groundor base-cojat of relatively low electrical resistability and comprising electrically conductive powder bound by an oleophilic and water-resistant adhesive. Over the oleophilic ground-coat is a hydrophilic coating having much higher electrical resistivity than the ground coat, but having in at least its surface a minor quantity of highly conductive particles.
  • Said hydrophilic coating has an exposed surface which comprises pigmentary powder bound by insolubilized hydrophilic adhesive, and which has the excellent lithographic properties characteristic of high-quality coated
  • a coating contains microscopic pores and interstices which preferably, but not necessarily, are lled with water-soluble zinc acetate or equivalent capable of reacting with lithographie solutions containing a phosphate ion to form a gelatinous precipitate to plug the pores and interstices and so keeping the surface wet by preventing rapid penetration of said lithographic solutions below the surface of the master.
  • An electrically inscribable lithographie printing plate or master comprising a paper base having on one side thereof a water-insoluble composite coating having at least three zones or layers, of which the base layer has good electrical conductivity and is strongly oleophilic; the intermediate zone contains cuprous thiocyanate and hydrophilic binder and has a lower electrical conductivity than said base layer; yand the top zone contains cuprous thiocyanate, hydrophilic binder, and .a substance which gives it a slightly higher conductivity than the intermediate zone.
  • a coated paper product adapted for use as an electrically inscribable lithographie printing master comprising a base of sized paper, a conductive base-coat of electrically conductive powder bound with water-insoluble adhesive of highly oleophilic properties, an intermediate coating of much lower electrical conductivity than said base-coat containing cuprous thiocyanate bound by an insolubilized hydrophilic adhesive, and a top coating containing cuprous thiocyanate, insolubilized hydrophilic adhesive and a small proportion of powder which possesses higher electrical conductivity than said cuprous thiocyanate, said top coating having a higher electrical conducf tivity than said intermediate coating.
  • a coated paper product adapted for use as an electrically inscribable lithographie printing master which consists of a sized paper base which has on one side an oleophilic base coating of good electrical conductivity comprising finely divided electrically conductive carbon black bound by an oleophilic and water-resistant resinous adhesive; an intermediate hydrophilic coating comprising cuprous thiocyanate bound by insolubilized protein adhesive, said intermediate coating having much lower electrical conductivity than said base coating; and a hydrophilic top coating comprising cuprous thiocyanate, a small proportion of carbon black, and polyvinyl alcohol adhesive insolubilized by an amino-aldehyde condensate, said top coating having somewhat higher electrical conductivity than said intermediate coating, said top coating possessing interstices and pores which contain water soluble zinc acetate in substantial amount.

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  • Printing Plates And Materials Therefor (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Paper (AREA)
US79250559 1959-02-11 1959-02-11 Electrically inscribable lithographic masters Expired - Lifetime US3151549A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
NL248212D NL248212A (enrdf_load_stackoverflow) 1959-02-11
NL120974D NL120974C (enrdf_load_stackoverflow) 1959-02-11
BE586149D BE586149A (enrdf_load_stackoverflow) 1959-02-11
US79250559 US3151549A (en) 1959-02-11 1959-02-11 Electrically inscribable lithographic masters
GB4001259A GB884504A (en) 1959-02-11 1959-11-25 Electrically inscribable recording blanks suitable for use as lithographic masters
FR814173A FR1246443A (fr) 1959-02-11 1959-12-24 Clichés lithographiques pouvant être gravés électriquement
DEW26958A DE1167365B (de) 1959-02-11 1959-12-24 Elektrisch beschreibbare lithographische Flachdruckfolie

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US79250559 US3151549A (en) 1959-02-11 1959-02-11 Electrically inscribable lithographic masters

Publications (1)

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US3151549A true US3151549A (en) 1964-10-06

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US79250559 Expired - Lifetime US3151549A (en) 1959-02-11 1959-02-11 Electrically inscribable lithographic masters

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US (1) US3151549A (enrdf_load_stackoverflow)
BE (1) BE586149A (enrdf_load_stackoverflow)
DE (1) DE1167365B (enrdf_load_stackoverflow)
FR (1) FR1246443A (enrdf_load_stackoverflow)
GB (1) GB884504A (enrdf_load_stackoverflow)
NL (2) NL120974C (enrdf_load_stackoverflow)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3302565A (en) * 1963-09-19 1967-02-07 Columbia Ribbon & Carbon Thermographic methods and products
US3722463A (en) * 1970-08-19 1973-03-27 Sumitomo Metal Ind Tube coating apparatus
US4082902A (en) * 1973-09-18 1978-04-04 Kabushiki Kaisha Ricoh Spark-recording type printing method and spark-recording material for use thereof

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2534650A (en) * 1947-05-09 1950-12-19 Warren S D Co Planographic printing plate and method of making same
US2554017A (en) * 1946-11-14 1951-05-22 Timefax Corp Electroresponsive recording blank
US2664044A (en) * 1948-01-16 1953-12-29 Timefax Corp Electric signal recording blank
US2693145A (en) * 1948-03-09 1954-11-02 Dick Co Ab Lithographic printing plate and method of making
US2726168A (en) * 1951-07-11 1955-12-06 Western Union Telegraph Co Electrosensitive recording and duplicating blank
US2766688A (en) * 1951-03-06 1956-10-16 Polychrome Corp Planographic printing plate
GB763528A (en) * 1954-08-23 1956-12-12 Timefax Corp Improvements in planographic master forming blank and method of making the same
GB767074A (en) * 1954-03-18 1957-01-30 Creed & Co Ltd Electrically inscribable lithographic offset printing plate
US2951441A (en) * 1956-01-16 1960-09-06 Timefax Corp Lithographic printing plates and coatings therefor
US2983220A (en) * 1955-03-16 1961-05-09 Timefax Corp Electro-sensitive planographic printing plate

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB551856A (en) * 1940-11-09 1943-03-12 William George Harold Finch Facsimile recording paper

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2554017A (en) * 1946-11-14 1951-05-22 Timefax Corp Electroresponsive recording blank
US2534650A (en) * 1947-05-09 1950-12-19 Warren S D Co Planographic printing plate and method of making same
US2664044A (en) * 1948-01-16 1953-12-29 Timefax Corp Electric signal recording blank
US2693145A (en) * 1948-03-09 1954-11-02 Dick Co Ab Lithographic printing plate and method of making
US2766688A (en) * 1951-03-06 1956-10-16 Polychrome Corp Planographic printing plate
US2726168A (en) * 1951-07-11 1955-12-06 Western Union Telegraph Co Electrosensitive recording and duplicating blank
GB767074A (en) * 1954-03-18 1957-01-30 Creed & Co Ltd Electrically inscribable lithographic offset printing plate
GB763528A (en) * 1954-08-23 1956-12-12 Timefax Corp Improvements in planographic master forming blank and method of making the same
US2983220A (en) * 1955-03-16 1961-05-09 Timefax Corp Electro-sensitive planographic printing plate
US2951441A (en) * 1956-01-16 1960-09-06 Timefax Corp Lithographic printing plates and coatings therefor

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3302565A (en) * 1963-09-19 1967-02-07 Columbia Ribbon & Carbon Thermographic methods and products
US3722463A (en) * 1970-08-19 1973-03-27 Sumitomo Metal Ind Tube coating apparatus
US4082902A (en) * 1973-09-18 1978-04-04 Kabushiki Kaisha Ricoh Spark-recording type printing method and spark-recording material for use thereof

Also Published As

Publication number Publication date
BE586149A (enrdf_load_stackoverflow) 1900-01-01
GB884504A (en) 1961-12-13
NL248212A (enrdf_load_stackoverflow) 1900-01-01
DE1167365B (de) 1964-04-09
FR1246443A (fr) 1960-11-18
NL120974C (enrdf_load_stackoverflow) 1900-01-01

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