# US 4,391,879 A · Gravure printing base cylinder, and method of its manufacture > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,391,879 A - Document ID: US4391879A - Status: Granted - Kind: A - Application number: 06/326,506 - Filed: 1981-12-02 - Granted: 1983-07-05 - Earliest claimed: 1980-12-12 - Assignees: W. C. Heraeus GmbH - Inventors: Peter Fabian; Theo Muller - Web page: https://patentgrep.com/patent/US4391879A ## CPC - C23C 4/06: Metallic material - B41N 1/006: {made entirely of inorganic materials other than natural stone or metals, e.g. ceramics, carbide materials, ferroelectric materials} - Y10T 428/12049: Nonmetal component - Y10T 428/12063: Nonparticulate metal component - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - B41N: PRINTING PLATES OR FOILS (photosensitive material G03); MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A roto-gravure printing base cylinder is made by providing a cylindrical body (1), for example of steel, and applying thereover a cover layer (2) by thermal spraying, for example plasma-spraying, or arc-spraying. The cover layer is made of a material which is inert with respect to electrolytes used in applying a further copper layer over the cover layer to form a finished roto-gravure cylinder for optical engraving, for example an electrochemical valve metal, preferably tantalum, niobium or, most desirably, titanium oxide, forming a matrix in which, before application of the material as a layer on the steel cylinder, electrochemically active materials are applied made of a metal, preferably of the platinum group or other noble metal, and uniformly distributed over the surface, settled on the matrix material. ## Claims ### Claim 1 Printing base cylinder, for plating in an electrolyte bath, having a cylindrical body (1); and a cover layer (2) thereon which is electrically conductive, electrochemically active, and inert with respect to the plating electrolyte, wherein, in accordance with the invention, the cover layer (2) comprises a matrix formed by an oxide of a valve metal; and particles homogeneously distributed in said matrix comprising at least one of the materials selected from the group consisting of: a noble metal, iridium; ruthenium. ### Claim 2 (depends on 1) Cylinder according to claim 1, wherein the matrix comprises an oxide of titanium, tantalum, or niobium. ### Claim 3 (depends on 1) Cylinder according to claim 1, wherein the matrix comprises under-stoichiometric titanium oxide in the form of granules, and the particles comprise platinum particles of from 0.1 to 10%, preferably 1 to 5%, by weight, of the matrix settled thereon. ### Claim 4 (depends on 1) Cylinder according to claim 1, wherein the matrix comprises titanium oxide in the form of TiO.sub.2-x, wherein x=0.04 to 0.06. ### Claim 5 (depends on 4) Cylinder according to claim 4, wherein the particles comprise platinum. ### Claim 6 (depends on 5) Cylinder according to claim 5, wherein the platinum particles are present, by weight, by about 1-5%, with respect to the matrix. ### Claim 7 (depends on 1) Cylinder according to claim 1, wherein said cover layer (2) has a thickness of from between about 0.05 mm to about 1 mm. ### Claim 8 (depends on 7) Cylinder according to claim 7, wherein the thickness of the cover layer (2) is between about 0.08 and 0.12 mm. ### Claim 9 (depends on 6) Cylinder according to claim 6, wherein the cover layer (2) is dense or liquid-tight with respect to the electrolyte bath, and has a thickness of between about 0.05 and 0.15 mm. ### Claim 10 (depends on 9) A roto-gravure printing cylinder comprising the printing cylinder of claim 9; and an outer layer or jacket of copper suitable for photo-engraving applied over said cover layer (2). ### Claim 11 Method of making a gravure printing base cylinder for use in an electrolyte bath having a cylinder body (1) and a cover layer (2) applied thereover, comprising the steps of settling electrically conductive particles on a film-forming or valve metal oxide, which particles are inert with respect to the electrolyte of the electrolyte bath, to form a cover coating layer substance; and, after forming said substance, applying said substance in powder or granular form, by thermal spraying on the cylindrical body (1) to thereby form said cover layer (2) thereon. ### Claim 12 (depends on 11) Method according to claim 11, wherein the applying step comprises plasma-spraying. ### Claim 13 (depends on 11) Method according to claim 11, wherein said applying step comprises arc-spraying. ### Claim 14 (depends on 11) Method of making a roto-gravure printing cylinder comprising: carrying out the steps of claim 11 and then immersing the coated cylinder body (1) with the cover layer (2) thereon in the electrolytic bath and depositing a copper jacket on said cover layer (2). ### Claim 15 (depends on 10) Method of removing a roto-gravure copper jacket from a rotor-gravure printing cylinder wherein said printing cylinder comprises the cylinder of claim 10 including the step of immersing said printing cylinder in an electrolyte bath; and removing said copper jacket by anodic removal, with application of current polarized to remove the copper jacket from said cover layer.