Classifications

• • 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
  • G03G13/28—Planographic printing plates
• • 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
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D133/00—Coating compositions based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Coating compositions based on derivatives of such polymers
  • C09D133/02—Homopolymers or copolymers of acids; Metal or ammonium salts thereof
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording-members for original recording by exposure, e.g. to light, to heat or to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/02—Charge-receiving layers
  • G03G5/024—Photoelectret layers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L25/00—Compositions of, homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Compositions of derivatives of such polymers
  • C08L25/02—Homopolymers or copolymers of hydrocarbons
  • C08L25/04—Homopolymers or copolymers of styrene
  • C08L25/08—Copolymers of styrene
  • C08L25/10—Copolymers of styrene with conjugated dienes
• • 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
  • Y10T428/3188—Next to cellulosic
  • Y10T428/31895—Paper or wood

Definitions

• Such coatings obviate the necessity for pre-treatment of the lithographic plates by brushing and/or by application of a brush coat of a polyvalent metal salt.
• they are completely waterproof, porous and lithographic and give good adhesion of images applied with carbon typewriter ribbons.
• the present invention relates to hydrophilic coatings for lithographic plates. More particularly, it relates to hydrophilic basecoats for lithographic plates.
• Lithographic surfaces have previously been prepared by applying to suitable carriers, coatings comprising casein and ester gum to function as a water receptive hydrophilic coating.
• suitable carriers comprising casein and ester gum to function as a water receptive hydrophilic coating.
• the latter included such materials as casein, inert fillers and formaldehyde. and were applied in one or more layers depending upon the number of copies to be made from the lithographic plate.
• a wash coat consisting of a solution of a polyvalent metal salt, such as aluminum formate, aluminum chloride, zinc chloride or the like.
• a lihographic plate is wet by application of water to the non-image areas. Accordingly, when an imaged plate is pressed against the rubber blanket of an offset copy machine, the ink which is on the image areas will come off onto the blanket while areas in contact with the non-image areas will remain clear since these areas of the plate are wet only with water and have no ink on them.
• the blanket is then pressed against a paper sheet to transfer the ink image to the paper,
• the plate In preparing a lithographic plate for printing, the plate is treated with an aqueous etch solution. If the aqueous solution works into the body of the plate, the surface of the plate may not be completely wetted by the solution fectly blank will show background discoloration or become darkened or toned. This incomplete wetting of the surface of the plate may also occur during printing.
• an object of the present invention is to provide means for obviating the difiiculties previously inherent in paper base lithographic plates.
• Another object of the invention is to produce and to provide a method for producing a new and improved lithographic surface.
• Still another object is to produce a hydrophilic basecoat for lithographic plates.
• a further object is to produce a coating which may be used as the primary topcoat for short run lithographic plates for direct imaging.
• Applicants new coating composition basically comprises zinc oxide, ammonia neutralized polyacrylic acid, an inert filler and a styrene-butadiene copolymer. In some instances, also, it is desirable to include zinc acetate in the. composition.
• the inert filler used in applicants claimed composition can be clay, talc, diatomaceous earth, satin white, silica or other such pigments customarily used in lithographic plates, i.e., which should not react with the etching solution.
• the ratio of inert filler to zinc oxide is preferably of the order of 2.4 to 1.
• the zinc oxide and inert pigments are bonded together on the lithographic plate by use of a combination of ammonia neutralized polyacrylic acid and styrene-butadiene copolymers.
• the polyacrylic acid should preferably have a molecular weight of at least 60,000 and is neutralized with ammonia to a pH of above 9.5.
• the preferred styrene-butadiene copolymer contains about 60% styrene and 40% butadiene and is added to the coating composition in emulsion form.
• the ratio of zinc oxide to adhesive should preferably be of the order of 1-4 to 1, and preferably 2.2-2.7 to 1 for best results.
• Suitable supports for the lithographic plates may include paper, fiberboard, textile fabrics, plastic sheet stock or metal strips preferably thin enough to provide sufiicient flexibility for bending about a typewriter platen and at the same time having sufiicient strength to maintain dimensional stability for at least the number of copies to be produced therefrom.
• the base stock comprises paper or other sheet stock of fibrous character having a high degree of water absorption
• material such as resin solutions
• EXAMPLE I The following compositions were prepared by high shear mixing of the zinc oxide and inert filler with about one-third of the ammonia neutralized polyacrylic acid and enough water to produce a thick paste. The remainder of the ammonia neutralized polyacrylic acid was then slowly added as a 27% solution of the acid in water, allowing suificient time for the polyacrylic acid to react completely with the zinc oxide pigment.
• the amounts of materials in this and subsequent examples are parts by weight of solids unless otherwise stated.
• the above composition was blade coated at the rate of 4 pounds per 3300 square feet, onto a wet strength rawstock previously coated on the same side with 6 pounds per 3300 square feet of a starch-clay-zinc oxidemelamine resin composition.
• the resulting dried coating was completely waterproof and lithographic, as well as porous, resulting in good adhesion of images applied with a carbon typewriter ribbon.
• the master thus evaluated gave satisfactory results except that the etching solution soaked into the sheet rather rapidly causing toning for the first 25 copies when there was a time delay between etching and running on the press.
• Viscosity-43.2 poises MacMichael at 75 F The composition was formulated as described above and approximately 4.25 pounds per 3300 square feet of the resulting product was applied by a blade coater to a wet strength rawstock previously coated with 6 pounds per 3300 square feet of a starch-clay-zinc oxide-melamine formaldehyde resin.
• the dried sheet prepared as above described was then coated with a typical lithographic coating composition and supercalendered to improve the surface characteristics of the coated paper.
• the sheet prepared as above described was then imaged with 29 different types of typewriter ribbons in order to more fully evaluate the lithographic properties of the sheet and then run on an A. B. Dick offset duplicator. Of the 29 ribbons tested, 25 gave a copy life of at least 500 copies. Under similar conditions, only 15 ribbons gave comparable results with lithographic plates prepared by prior methods, unless they had been previously washed with an aqueous solution of a polyvalent metal salt.
• the lithographic plate of the present invention was also found to function equally well when printing with magnetic inks.
• the image characters and the magnetic inks were of the type specified for mechanized check handling by the Bank Management Commission of the American Bankers Association. Images were prepared using carbon ribbons backed with non fabric backings such as polyethylene terephthalate (Mylar) and polyethylene films, and the imaged plate was run on the duplicator using a specified magnetic ink. Excellent definition of the characters with no voids or ink smears was obtained in the copies produced.
• the basecoat compositions described above have been found suitable for use as a basecoat for lithographic plates to be imaged electrophotographically, applicant's new basecoats being particularly useful for this purpose and eliminates the necessity for the separate barrier coat normally required between the electrophotographic coat and the basecoat customarily used in making such plates.
• the adhesives used in making electrophotographic plates for offset lithographic printing are water insoluble but are soluble in aromatic organic solvents, such as toluene.
• a barrier layer is therefore required to prevent the organic solvent from soaking into the basestock and producing a non-uniform electrophotographic coating and subsequent variations in the image on the surface.
• Applicants claim basecoat adequately prevents the entry of the organic solvent into the basestock and at the same time provides satisfactory anchorage of the electrophotographic coat to the base coat.
• Applicants new basecoat can, therefore, be used with decided advantage for several different purposes such as used directly as a short-run lithographic plate, or as the basecoat for long-run lithographic plates to be imaged directly or by electrophotographic means.
• references Cited Coating compositions for production of hydrophilic UNITED STATES PATENTS coatings comprising, zlnc oxide, an lnert filler, 8-10 parts by weight ammonia neutralized polyacrylic acid, and 1-4 3,349,704 10/1967 on "-5- 101-461 parts by weight styrene-butadiene copolymer. 5 3,230,873 1/1966 101-462 2.
• the composition of claim 1 wherein the inert filler 2,951,441 9/1960 Wolf et 101-462 is selected from the group consisting of clay, talc, diato- 2,760,431 8/1956 Beatty 101462 maceous earth, satin white, and silica.
• composition of claim 1 wherein the ratio of MORRIS LIEBMANPnmary Exammer inert filler to zinc oxide is of the order of 2.4 to 1. 10 L. T. JACOBS, Assistant Examiner 4.
• a paper substrate having on the surface thereof a 155 dried coating composition of claim 1.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Paints Or Removers (AREA)
• Paper (AREA)
• Printing Plates And Materials Therefor (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=24193229

Family Applications (1)

Country Status (5)

Cited By (25)

Families Citing this family (2)

• 1966
  • 1966-05-12 US US549491A patent/US3582519A/en not_active Expired - Lifetime
• 1967
  • 1967-02-28 NL NL6703161A patent/NL6703161A/xx unknown
  • 1967-04-25 DE DE19671671633 patent/DE1671633A1/de active Pending
  • 1967-04-28 BE BE697782D patent/BE697782A/xx unknown
  • 1967-05-02 GB GB20189/67A patent/GB1138102A/en not_active Expired

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