# US 10,118,857 B2 · Method for internally coating a hollow glass body > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,118,857 B2 - Document ID: US10118857B2 - Status: Granted - Kind: B2 - Application number: 14/758,726 - Filed: 2014-01-29 - Published: 2015-12-10 - Granted: 2018-11-06 - Earliest claimed: 2013-01-29 - Assignees: Bormioli Luigi S.P.A. - Applicants: BORMIOLI LUIGI S.p.A. - Inventors: Simone Baratta - Web page: https://patentgrep.com/patent/US10118857B2 ## CPC - C03C 17/004: {Coating the inside} - B05D 7/22: to internal surfaces, e.g. of tubes - B05D 7/227: {of containers, cans or the like} - C03C 17/04: by fritting glass powder - B05D 1/02: performed by spraying - C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS - B05D: PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL (conveying articles or workpieces through baths of liquid B65G, e.g. B65G49/02) ## Abstract The present invention regards a method for internally coating a hollow glass body comprising the steps of: (a) applying on at least one internal surface of said hollow body at least one coating composition in form of liquid dispersion comprising at least one glass frit and at least one polymeric dispersing agent; (b) subjecting said internal surface comprising said coating composition to a thermal treatment, so as to obtain a vitrified coating layer. ## Claims ### Claim 1 Method for internally coating a hollow glass body comprising, in the following order: (a) applying by a spraying device, onto at least an internal surface of said hollow body, at least one coating composition, to obtain a coated glass body, wherein the coating composition is in the form of aqueous dispersion comprising at least one glass frit and at least one polymeric dispersing agent, said agent being present in such an amount that said composition has a thixotropic index lower than 200 second; said hollow body and said spraying device being in movement with respect to each other, said movement comprising keeping said hollow body rotating on itself during the application of said coating composition; and (b) subjecting said internal surface comprising said coating composition to a thermal treatment at a temperature in the range of 450-800° C., so as to obtain a vitrified coating layer, wherein said frit is present in the composition in a quantity comprised in the range 50-80% by weight with respect to the weight of the coating composition, wherein said polymeric dispersing agent is present in the composition in a quantity comprised in the range 1-20% by weight with respect to the weight of the liquid phase of said dispersion, and wherein said frit comprises, based on a total weight of said frit: SiO2 30-45%; Na2O 1-4%; P2O5 0-1%; CaO 2-6%; K2O 2-6%; TiO2 4-9%; ZnO 8-18%; BaO 0-2%; Bi2O3 2-6%; and B2O3 10-20%. ### Claim 2 (depends on 1) Method according to claim 1, wherein said at least one dispersing agent is a polycarboxylic thermoplastic resin. ### Claim 3 (depends on 1) Method according to claim 1, wherein said at least one dispersing agent is selected from among: a polyester resin, an acrylic resin, an amide resin and a vinyl resin. ### Claim 4 (depends on 1) Method according to claim 1 wherein said at least one dispersing agent is a cellulose resin. ### Claim 5 (depends on 1) Method according to claim 1, wherein said thixotropic index is lower than or equal to 100 seconds. ### Claim 6 (depends on 1) Method according to claim 1, wherein said thixotropic index is greater than or equal to 10 seconds. ### Claim 7 (depends on 1) Method according to claim 1, wherein said frit comprises at least one pigment. ### Claim 8 (depends on 1) Method according to claim 1, wherein said coating composition comprises at least one pigment dispersed in the liquid phase of said dispersion. ### Claim 9 (depends on 1) Method according to claim 1, wherein said coating composition has a linear thermal expansion coefficient (measured on the solid fraction) in the range 50-90·10−7 K−1. ### Claim 10 (depends on 1) Method according to claim 1, wherein said coating composition has a viscosity in the range 1-50 Pa·s. ### Claim 11 (depends on 4) Method according to claim 4, wherein said cellulose resin is a cellulose ether, a cellulose ester, or a mixture thereof. ### Claim 12 (depends on 11) Method according to claim 11, wherein said cellulose ether or ester has a degree of substitution in the range between 1-2. ### Claim 13 (depends on 11) Method according to claim 11, wherein said cellulose either or ester has a degree of substitution in the range between 0.5-2.2. ### Claim 14 (depends on 1) Method according to claim 1, wherein said thixotropic index is lower than or equal to 60 seconds. ### Claim 15 (depends on 1) Method according to claim 1, wherein said thixotropic index is greater than or equal to 30 seconds. ### Claim 16 (depends on 1) Method according to claim 1, wherein said coating composition has a linear thermal expansion coefficient (measured on the solid fraction) in the range 60-80·10−7 K−1. ### Claim 17 (depends on 1) Method according to claim 1, wherein said coating composition has a linear thermal expansion coefficient (measured on the solid fraction) in the range 65-75·10−7 K−1. ### Claim 18 (depends on 1) Method according to claim 1, wherein said coating composition has a viscosity in the range 5-30 Pa·s. ### Claim 19 (depends on 1) Method according to claim 1, wherein said coating composition has a viscosity in the range 8-20 Pa·s. ### Claim 20 (depends on 1) Method according to claim 1, wherein said frit is present in the composition in a quantity comprised in the range 55-70% by weight with respect to the weight of the coating composition. ### Claim 21 (depends on 1) Method according to claim 1, wherein said polymeric dispersing agent is present in the composition in a quantity comprised in the range 5-15% by weight with respect to the weight of the liquid phase of said dispersion. ### Claim 22 (depends on 1) Method according to claim 1, wherein said thermal treatment is carried out at a temperature in the range of 500-700° C.