# US 9,902,861 B2 · Single color reversible temperature indicator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,902,861 B2 - Document ID: US9902861B2 - Status: Granted - Kind: B2 - Application number: 14/746,063 - Filed: 2015-06-22 - Published: 2015-12-24 - Granted: 2018-02-27 - Earliest claimed: 2014-06-21 - Assignees: KLT Technologies - Applicants: KLT Technologies - Inventors: Randall Lane; Steve Yeager; Victor Uttinger - Web page: https://patentgrep.com/patent/US9902861B2 ## CPC - C09D 5/14: Paints containing biocides, e.g. fungicides, insecticides or pesticides (C09D5/16 takes precedence) - C09D 5/26: Thermosensitive paints - C09D 7/40: Additives - C09D 11/10: based on artificial resins - C09D 11/50: Sympathetic, colour changing or similar inks - C09J 7/29: Laminated material (metallised plastics C09J7/22) - G01K 11/16: of organic materials - G01K 11/18: of materials which change translucency - C09J 2203/334: as a label - C09J 2301/302: the adhesive being pressure-sensitive, i.e. tacky at temperatures inferior to 30°C - 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 (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D) - C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H) - G01K: MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR (radiation pyrometry G01J5/00) ## Abstract A printable ink for reversible thermal indicators that includes microcapsules retaining therein a core material that is opaque as a solid and transparent as a liquid, and a binder and a rheology modifier as a carrier for the microcapsules. The binder and the rheology modifier are either the same substance or different substances. The microcapsules in the printable ink retain the core material therein for repeated, reversible transitions from solid to liquid and liquid to solid. ## Claims ### Claim 1 A printable ink for reversible thermal indicators comprising: microcapsules retaining therein a core material that is opaque as a solid and transparent as a liquid; and a binder and a rheology modifier as a carrier for the microcapsules; wherein the microcapsules retain the core material therein for repeated, reversible transitions from solid to liquid and liquid to solid; wherein the binder and the rheology modifier are the same substance or are different substances; wherein the core material comprises: a phase change material mixed with a nucleation aid; wherein the nucleation aid reduces supercooling, thereby the core material becomes solid reset at a known temperature, and is selected from one or more of hyperbranched hydrocarbon polymers, fatty acids, microcrystalline waxes, isoparaffins, polyethylene waxes, and combinations thereof. ### Claim 2 (depends on 1) The printable ink of claim 1, wherein the core material is selected from the group consisting of one or more straight chain hydrocarbons having 12-44 carbons, fatty acid esters, and fatty alcohols and combinations thereof. ### Claim 3 (depends on 1) The printable ink of claim 1, wherein the core material comprises about 25% to about 48% by weight of the printable ink. ### Claim 4 (depends on 3) The printable ink of claim 3, wherein the core material comprises about 27% to about 37% by weight of the printable ink. ### Claim 5 (depends on 1) The printable ink of claim 1, wherein the core material has a phase change from solid to liquid or liquid to solid within one degree Celsius. ### Claim 6 (depends on 1) The printable ink of claim 1, wherein the wall material is selected from the group consisting of gelatin, albumin, methyl cellulose, carboxy methylcellulose, and combinations thereof. ### Claim 7 (depends on 1) The printable ink of claim 1, wherein the binder and the rheology modifier are the same substance and comprise one or more of an aqueous polyvinyl alcohol solution and a carboxy methyl cellulose. ### Claim 8 (depends on 1) The printable ink of claim 1, further comprising one or more of a biocide and a foam control agent. ### Claim 9 (depends on 1) A reversible temperature indicator comprising: a substrate having a colored surface with at least a portion of the colored surface covered with the printable ink of claim 1; wherein at least the portion of the colored surface covered by the printable ink is hidden by the printable ink and revealed when the substrate reaches a temperature above a transition temperature of the core material, which renders the core material transparent. ### Claim 10 (depends on 9) The reversible temperature indicator of claim 9, further comprising an adhesive layer applied to a surface of the substrate opposite the colored surface thereof, and optionally a release layer adhered to the adhesive layer. ### Claim 11 (depends on 10) The reversible temperature indicator of claim 10, wherein the adhesive layer is a pressure sensitive adhesive layer. ### Claim 12 (depends on 9) The reversible temperature indicator of claim 9, further comprising a primer coating between the colored surface of the substrate and the printable ink. ### Claim 13 (depends on 12) The reversible temperature indicator of claim 12, wherein the primer coating comprises a polymer solution or an emulsion of acrylic, styrene acrylic, polyurethane, ethylene-acrylic acid, or combinations thereof. ### Claim 14 (depends on 9) The reversible temperature indicator of claim 9, further comprising a protective coating covering the printable ink applied to the substrate. ### Claim 15 (depends on 14) The reversible temperature indicator of claim 14, wherein the protective coating comprises a protective lamination tape. ### Claim 16 (depends on 9) The reversible temperature indicator of claim 9, wherein the colored surface of the substrate includes an image or word hidden by the printable ink and revealed when the substrate reaches a temperature above the transition temperature of the core material. ### Claim 17 (depends on 9) The reversible temperature indicator of claim 9, wherein the core material is selected from the group consisting of one or more straight chain hydrocarbons having 12-44 carbons ester waxes, and combinations thereof. ### Claim 18 (depends on 17) The reversible temperature indicator of claim 17, wherein the core material comprises about 25% to about 48% by weight of the printable ink. ### Claim 19 A printable ink for reversible thermal indicators comprising: microcapsules retaining therein a core material that is opaque as a solid and transparent as a liquid; and a binder and a rheology modifier as a carrier for the microcapsules; wherein the microcapsules retain the core material therein for repeated, reversible transitions from solid to liquid and liquid to solid, and the core material has a phase change from solid to liquid or liquid to solid within one degree Celsius; wherein the binder and the rheology modifier are the same substance or are different substances.