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US4149895A Expired / Lapsed US ⏱️ 0.0 years remaining

Glass with high refractive index and low density

Assignee: Corning Glass Works
•
Filing: 1978-09-11
•
Granted: 1979-04-17
•
Expires: 1998-09-11
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Abstract

Abstract The instant invention relates to glasses suitable for optical and ophthalmic applications which can be melted and formed utilizing continuous commercial processes. The glasses exhibit indices of refraction between about 1.675-1.720, densities between about 3.1-3.4 g/cm 3 , Abbe numbers between about 33-36.5, viscosities at the liquidus temperature of at least about 220 poises, and very high chemical durability as evidenced by a loss of weight of less than 0.01 mg/cm 2 in the American Optical test. The glasses consist essentially, in weight percent on the oxide basis, of 40-46% SiO 2 , 0-3% Al 2 O 3 , 40-46% SiO 2 +Al 2 O 3 , 13-17% TiO 2 , 4-11% ZrO 2 , 0-2% MgO, 3-7% CaO, 4-8% CaO+MgO, 8-16% BaO, 0-4% SrO, 15-25% CaO+BaO+SrO, 2-10% Nb 2 O 5 , 0-3% Li 2 O, 2-7% Na 2 O, 3-8% K 2 O, 5-12% Li 2 O+Na 2 O+K 2 O.

Inventors

  • 👤 Jean E. Boudot
  • 👤 Henri J. Meyer

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 14:51
CPC Classifications
C; C03; C03C; C03C4/00; C03C4/20; C03C3/00; C03C3/04; C03C3/076; C03C3/078; Y; Y10; Y10S; Y10S501/00; Y10S501/90; Y10S501/903

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 113 words
A glass having a refractive index between about 1.675-1.720, a density between about 3.1-3.4 g/cm 3 , an Abbe number between about 33-36.5, a viscosity at the liquidus temperature of at least 220 poises, and excellent resistance to acid attack, as measured in the American Optical test, consisting essentially, in weight percent on the oxide basis, of ______________________________________ SiO.sub.2 40-46 Al.sub.2 O.sub. 3 0-3 SiO.sub.2 + Al.sub.2 O.sub.3 40-46 TiO.sub.2 13-17 ZrO.sub.2 4-11 MgO 0-2 CaO 3-7 BaO 8-16 SrO 0-4 CaO + MgO 4-8 CaO + BaO + SrO 15-25 Nb.sub.2 O.sub.5 2-10 Li.sub.2 O 0-3 Na.sub.2 O 2-7 K.sub.2 O 3-8 Li.sub.2 O + Na.sub.2 O + K.sub.2 O 5-12 ______________________________________
Claim 2
Dependent Claim 113 words
A glass having a refractive index between about 1.675-1.720, a density between about 3.1-3.4 g/cm 3 , an Abbe number between about 33-36.5, a viscosity at the liquidus temperature of at least 220 poises, and excellent resistance to acid attack, as measured in the American Optical test, consisting essentially, in weight percent on the oxide basis, of ______________________________________ SiO.sub.2 40-46 Al.sub.2 O.sub. 3 0-3 SiO.sub.2 + Al.sub.2 O.sub.3 40-46 TiO.sub.2 13-17 ZrO.sub.2 4-11 MgO 0-2 CaO 3-7 BaO 8-16 SrO 0-4 CaO + MgO 4-8 CaO + BaO + SrO 15-25 Nb.sub.2 O.sub.5 2-10 Li.sub.2 O 0-3 Na.sub.2 O 2-7 K.sub.2 O 3-8 Li.sub.2 O + Na.sub.2 O + K.sub.2 O 5-12 ______________________________________
Claim 3
Dependent Claim 17 words
A glass according to claim 1 which also contains up to 5% B 2 O 3 .

References Cited (Backward Citations)

US3870531A Cited
US4055435A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-04-16 1982-10-16 1983-04-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-04-16 1986-10-16 1987-04-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-04-16 1990-10-16 1991-04-17 $7700.00 Window Closed / Lapsed

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