# US 5,346,738 A · Identification label with micro-encapsulated etchant > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,346,738 A - Document ID: US5346738A - Status: Granted - Kind: A - Application number: 07/971,351 - Filed: 1992-11-04 - Granted: 1994-09-13 - Earliest claimed: 1992-11-04 - Assignees: X-Cal Corporation - Inventors: John Samonides - Web page: https://patentgrep.com/patent/US5346738A ## CPC - G09F 3/00: Labels, tag tickets, or similar identification or indication means (medals or badges A44C3/00; making labels B31D1/02; sheets temporarily attached together B42F; labelling B65C; labels on record carriers G11B23/38, G11B23/40); Seals; Postage or like stamps - B44C 1/227: {by etching} - B60R 13/10: Registration, licensing, or like devices - G09F 3/02: Forms or constructions (layered products B32B) - G09F 2003/028: {Labels containing microcapsules, e.g. ink microcapsules for indicia transfer} - Y10T 428/1405: Capsule or particulate matter containing [e.g., sphere, flake, microballoon, etc.] - Y10T 428/24802: Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.] - Y10T 428/2486: with outer strippable or release layer - Y10T 428/24876: Intermediate layer contains particulate material [e.g., pigment, etc.] - Y10T 428/24893: including particulate material - Y10T 428/24901: including coloring matter - Y10T 428/249994: Composite having a component wherein a constituent is liquid or is contained within preformed walls [e.g., impregnant-filled, previously void containing component, etc.] - Y10T 428/249997: Encapsulated liquid - Y10T 428/2839: with release or antistick coating - Y10T 428/2984: Microcapsule with fluid core [includes liposome] - Y10T 428/31504: Composite [nonstructural laminate] - G09F: DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS - B44C: PRODUCING DECORATIVE EFFECTS (processes for applying liquids or other fluent materials to surfaces, in general B05D; shaping of plastics or substances in a plastic state B29C; printing processes to produce transfer pictures B41M3/12; thermographic duplication or marking methods B41M5/00); MOSAICS; TARSIA WORK (imitation of mosaic or tarsia work patterns B44F11/04); PAPERHANGING {(labels G09F; multi-step processes for making paper labels or tags B31D1/02)} - B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An identification label for permanently marking a metal or other etchable surface such as an automobile part with an identifying indicia is disclosed. The label has a protective cover sheet, a pressure sensitive adhesive irremovably affixed to the cover sheet, and a liner with a release coating removably affixed to the adhesive. An identifying indicia comprising an etchant in a visible vehicle such as a printing ink is printed on the adhesive at the interface of the removable liner and the adhesive so that when the liner is removed, the remaining portions of the label may be adhesively attached to the metal surface with the etchant of the identifying indicia in etching contact therewith. The identifying indicia will thus be etched into the surface of the part for a permanent marking of the part. ## Claims ### Claim 1 An identification label for permanently marking a metal surface with an identifying indicia, said label comprising a protective cover sheet, a pressure sensitive adhesive having an inner and an outer surface and having its outer surface in intimate, irremovable contact with said cover sheet, a liner with a release coating removably affixed to the inner surface of said adhesive, and first identifying indicia comprising a micro-encapsulated metal etchant printed on the inner surface of said adhesive, whereby when said liner is removed, said label may be adhesively attached to a metal surface with the etchant of the identifying indicia in contact therewith, whereby said identifying indicia will be permanently etched into the metal surface. ### Claim 2 (depends on 1) The identification label of claim 1 wherein said metal etchant is micro-encapsulated acid. ### Claim 3 (depends on 2) The identification label of claim 2 wherein said micro-encapsulated acid is released by rupture of the material encapsulating the acid. ### Claim 4 (depends on 2) The identification label of claim 2 wherein said micro-encapsulated acid is released over a period of time by acid attack on the material encapsulating the acid. ### Claim 5 (depends on 2) The identification label of claim 2 wherein said micro-encapsulated acid is carried in a printing ink vehicle. ### Claim 6 (depends on 1) The identification label of claim 1 wherein said protective cover sheet is transparent and second identifying indicia is printed at the interface of said cover sheet and said adhesive, whereby said second identifying indicia is visible through said cover sheet. ### Claim 7 (depends on 6) The identification label of claim 6 wherein the first and second identification indicia are identical. ### Claim 8 (depends on 1) The identification label of claim 1 wherein said pressure sensitive adhesive is transparent or translucent and said cover sheet is transparent, whereby said first identifying indicia is visible through said cover sheet and said adhesive. ### Claim 9 A composite sheet forming an identification label for an etchable surface of a part, said composite comprising a carrier sheet having one surface coated with a release coating, a pressure sensitive adhesive layer having a first surface releasably adhering to the release coated surface of said carrier sheet and having a second surface, first printed indicia on said adhesive layer at the interface of said adhesive layer and said release coated surface of said carrier sheet, said first printed indicia comprising a micro-encapsulated etchant, a cover sheet irremovably affixed to the second surface of said pressure-sensitive adhesive layer, and second printed indicia at one side of said cover sheet visible from the cover sheet side of said composite sheet, whereby when said carrier sheet has been removed said first printed indicia is placed in contact with a surface of the part and the etchant will etch the etchable surface of the part to which the label has adhered. ### Claim 10 (depends on 9) The composite sheet of claim 9 wherein said cover sheet is transparent and said second printed indicia is printed at the interface of said adhesive layer and said cover sheet, whereby it will be visible through said cover sheet. ### Claim 11 (depends on 9) The composite sheet of claim 9 wherein said etchant is hydrochloric acid. ### Claim 12 A method of marking an etchable surface with an identifying indicia, said method comprising applying to the etchable surface to be marked a composite sheet comprising a cover sheet, a pressure sensitive adhesive layer having one surface irremovably affixed to the cover sheet and the identifying indicia printed on the opposite surface of the adhesive layer with a micro-encapsulated etchant which will etch the etchable surface, with the opposite surface of the adhesive layer and the micro-encapsulated etchant in intimate contact with the etchable surface, whereby the etchant will etch the identifying indicia into the etchable surface.