# US 11,306,020 B2 · Glass sheet with a high luminous transmittance and with warm-toned to neutral colored edges > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,306,020 B2 - Document ID: US11306020B2 - Status: Granted - Kind: B2 - Application number: 16/319,054 - Filed: 2017-07-18 - Published: 2019-11-28 - Granted: 2022-04-19 - Earliest claimed: 2016-07-20 - Assignees: Agc Glass Europe - Applicants: Agc Glass Europe - Inventors: Thomas Lambricht; Audrey Dogimont - Web page: https://patentgrep.com/patent/US11306020B2 ## CPC - C03C 3/095: containing rare earths - C03C 4/0092: {for glass with improved high visible transmittance, e.g. extra-clear glass} - C03C 2204/00: Glasses, glazes or enamels with special properties - 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 ## Abstract The invention relates to a glass sheet having a luminous transmission LTD4≥87% and having a composition free of antimony and arsenic, comprising total iron (expressed in the form of Fe2O3) from 0.002-0.04% and erbium (expressed in the form of Er2O3) from 0.003-0.1%. The glass sheet composition further having a redox ratio ≤32% and satisfying the formula 1.3*Fe2O3≤Er2O3−21.87*Cr2O3−53.12*Co≤2.6*Fe2O3. Such a glass sheet has a high luminous transmittance and has warm-toned to neutral colored edges and is particularly suitable due to its aesthetics as building glass or interior glass, as well as in furniture applications, as automotive glass, or as cover glass in electronic devices/displays. ## Claims ### Claim 1 A glass sheet having a composition comprising in weight percentage with respect to a total weight of the glass: SiO2 40-78%; Al2O3 0-18%; B2O3 0-18%; Na2O 0-20%; CaO 0-15%; MgO 0-12%; K2O 0-12%; BaO 0-5%; total iron (expressed in the form of Fe2O3) 0.002-0.04 wt %; and erbium (expressed in the form of Er2O3) 0.003-0.1 wt %, wherein the glass sheet composition has a redox ratio ≤32%, wherein 1.3*Fe2O3≤Er2O3-21.87*Cr2O3-53.12*Co≤2.6*Fe2O3, wherein the glass sheet composition is free of antimony and arsenic, wherein the glass sheet has a luminous transmission LTD4 ≥87%, and wherein the glass sheet has a* ≥0 and b* ≥0, a* and b* being measured for a sheet thickness of 4 mm in transmission with illuminant D65, 10°, SCI. ### Claim 2 (depends on 1) The glass sheet according to claim 1, wherein the composition comprises total iron from 0.002-0.03 wt %. ### Claim 3 (depends on 1) The glass sheet according to claim 1, wherein the composition comprises total iron from 0.002-0.02 wt %. ### Claim 4 (depends on 1) The glass sheet according to claim 1, wherein the composition has a redox ratio ≤30%. ### Claim 5 (depends on 1) The glass sheet according to claim 1, wherein the composition comprises Er2O3≤0.08 wt %. ### Claim 6 (depends on 1) The glass sheet according to claim 1, wherein the composition comprises Er2O3≥0.01 wt %. ### Claim 7 (depends on 1) The glass sheet according to claim 1, wherein the composition comprises Er2O3≥0.015 wt %. ### Claim 8 (depends on 1) The glass sheet according to claim 1, wherein the composition comprises a cerium content (expressed as CeO2)≤0.05 wt %. ### Claim 9 (depends on 1) The glass sheet according to claim 1, wherein the glass sheet has a luminous transmission LTD4 ≥89%. ### Claim 10 (depends on 1) The glass sheet according to claim 1, wherein the composition comprises 1.5*Fe2O3≤Er2O3-21.87*Cr2O3-53.12*Co. ### Claim 11 (depends on 1) The glass sheet according to claim 1, wherein the composition comprises 1.8*Fe2O3≤Er2O3-21.87*Cr2O3-53.12*Co. ### Claim 12 (depends on 1) The glass sheet according to claim 1, wherein the composition comprises Er2O3-21.87*Cr2O3-53.12*Co≤2.4*Fe2O3. ### Claim 13 (depends on 1) The glass sheet according to claim 1, wherein the composition comprises Er2O3-21.87*Cr2O3-53.12*Co≤2*Fe2O3. ### Claim 14 A glass sheet having a composition comprising, in weight percentage with respect to a total weight of the glass: SiO2 60-78%; Al2O3 0-8%; B2O3 0-4%; Na2O 5-20%; CaO 0-15%; MgO 0-12%; K2O 0-12%; BaO 0-5%; total iron (expressed in the form of Fe2O3) 0.002-0.04 wt %; and erbium (expressed in the form of Er2O3) 0.003-0.1 wt %, wherein the glass sheet composition has a redox ratio ≤32%, wherein 1.3*Fe2O3