# US 5,352,640 A · Colored glass compositions and glazings produced therewith > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,352,640 A - Document ID: US5352640A - Status: Granted - Kind: A - Application number: 08/044,554 - Filed: 1993-04-07 - Granted: 1994-10-04 - Earliest claimed: 1990-04-13 - Assignees: Saint-Gobain Vitrage International - Inventors: Pierre Combes; Jean-Jacques Massol; Pedro C. Alvarez - Web page: https://patentgrep.com/patent/US5352640A ## CPC - C03C 3/087: containing calcium oxide, e.g. common sheet or container glass - C03C 3/078: containing an oxide of a divalent metal, e.g. an oxide of zinc - C03C 4/02: for coloured glass - C03C 17/23: Oxides (C03C17/02 takes precedence) - C03C 2217/211: SnO2 - Y10S 501/904: Infrared transmitting or absorbing - Y10S 501/905: Ultraviolet transmitting or absorbing - 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 - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract The invention relates to a colored glass composition for producing glazings for use, e.g., as automobile sunroofs. The colored glass according to the invention is a soda-lime-silica glass comprising, as coloring agents, 1.4 to 4% iron oxide expressed as Fe.sub.2 O.sub.3 and 0 to 0.05% cobalt oxide, with the cobalt oxide exceeding about 0.02% when the Fe.sub.2 O.sub.3 is below about 2% and, optionally, selenium and chromium oxide, whereby the sum of the CoO+Se+Cr.sub.2 O.sub.3 is preferably less than about 0.24% by weight. The glass of the invention has a total light transmission factor under illuminant A equal to or below approximately 20% and a total energy transmission factor equal to or below approximately 12% for a thickness of 3.85 mm. ## Claims ### Claim 1 A glass composition for forming colored glazings consisting essentially of, in percent by weight, 64 to 75% SiO.sub.2, 5 to 15% CaO, 10 to 18% Na.sub.2 O, at least one of Al.sub.2 O.sub.3, B.sub.2 O.sub.3, MgO or K.sub.2 O, each in an amount of up to 5% by weight and CoO as a coloring agent in an amount of up to 0.05% by weight, wherein the amount of CoO is greater than about 0.02% by weight when Fe.sub.2 O.sub.3 is present in said composition in an amount less than 2% by weight, and selenium in an amount up to about 0.005%, and as a coloring agent, 1.4 to 4% Fe.sub.2 O.sub.3, wherein the amount of alkaline earth oxides is between about 6-16% by weight and the amount of alkali metal oxides is between about 10-20% by weight and wherein glazings formed of said composition when illuminated under Illuminant C, has a dominant percentage light transmission between about 485-570 nm, and which have a total light transmission factor under illuminant A of less than 20% and a total energy transmission factor of less than 12% when said glazings have a thickness of about 3.85 mm. ### Claim 2 (depends on 1) The composition of claim 1 which further comprises a color effective amount of chromium oxide as an additional coloring agent, wherein the total amount of CoO, selenium and Cr.sub.2 O.sub.3 is less than about 0.24% by weight of said composition. ### Claim 3 (depends on 2) The composition of claim 2 which consists essentially of 2 to 3% by weight Fe.sub.2 O.sub.3, 0.014 to 0.04 percent by weight CoO and up to 0.005% by weight selenium. ### Claim 4 (depends on 2) The composition of claim 2 which consists essentially of 1.4 to 2.5% by weight Fe.sub.2 O.sub.3, 0.015 to 0.003% by weight CoO and 0.0010 to 0.0035% by weight selenium. ### Claim 5 (depends on 2) The composition of claim 2 which consists essentially of 1.5 to 2.5% by weight Fe.sub.2 O.sub.3, 0.015 to 0.030% by weight CoO and 0.07 to 0.2% by weight Cr.sub.2 O.sub.3 ### Claim 6 (depends on 1) The composition of claim 1 wherein said Fe.sub.2 O.sub.3 comprises between about 16 to 40% by weight of FeO. ### Claim 7 (depends on 6) The composition of claim 6 wherein said Fe.sub.2 O.sub.3 is present in said composition in an amount between about 3-4% by weight. ### Claim 8 (depends on 3) A glazing comprising at least one colored glass sheet having the composition of claim 3. ### Claim 9 (depends on 4) A glazing comprising at least one colored glass sheet having the composition of claim 4. ### Claim 10 (depends on 5) A glazing comprising at least one colored glass sheet having the composition of claim 5. ### Claim 11 (depends on 8) A glazing comprising at least one colored glass sheet having the composition of claim 8. ### Claim 12 (depends on 8, 9, 10, 11) The glazing of claim 8, 9, 10 or 11 wherein the thickness of said glazing is between about 2 and 10 millimeters. ### Claim 13 (depends on 12) The glazing of claim 12 wherein the thickness of said glazing is between about 3 and 6 millimeters. ### Claim 14 (depends on 13) The glazing of claim 13 which further comprises at least one metal oxide layer coated upon at least a portion of said glazing.