High index fluorine-free phosphate glasses

Claim 2

A glass having a composition which is essentially fluorine-free and which exhibits an annealing point between 300°-340° C., a linear coefficient of thermal expansion over the temperature interval 25°-300° C. between 135-180×10 -7 /°C., a refractive index of at least 1.65, and a weight loss after exposure to boiling water for six hours no greater than 0.33% consisting essentially, expressed in terms of mole percent on the oxide basis, of: ______________________________________ P.sub.2 O.sub.5 24-36 ZnO 0-45 Li.sub.2 O 0-15 Na.sub.2 O 0-20 K.sub.2 O 0-10 Ag.sub.2 O 0-25 Tl.sub.2 O 0-25 Li.sub.2 O + Na.sub.2 O + K.sub.2 O + Ag.sub.2 O + Tl.sub.2 O 15-30 PbO 0-20 CaO 0-20 CuO 0-5 CeO.sub.2 0-2 SrO 0-20 BaO 0-20 CaO + SrO + BaO 0-25 Sb.sub.2 O.sub.3 0-61 Bi.sub.2 O.sub.3 0-10 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 0-61 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 + Ag.sub.2 O + Tl.sub.2 O 7-76 SnO 0-5 Al.sub.2 O.sub.3 0-5 B.sub.2 O.sub.3 0-10 Al.sub.2 O.sub.3 + B.sub.2 O.sub.3 0-10 ______________________________________ with the provisos that: (a) in the absence of Sb 2 O 3 and/or Bi 2 O 3 , the total Ag 2 O+Tl 2 O will range 11-25; (b) in the absence of Ag20 and/or Tl 2 O, the total Sb 2 O 3 +Bi 2 O 3 will range 7-61; (c) when present in the absence of Bi 2 O and/or Ag 2 O and/or Tl 2 O, Sb 3 O 3 will range 10-61 and, when present in the absence of Sb 2 O 3 and/or Ag 2 O and/or Tl 2 O, Bi 2 O 3 will range 7-10; (d) when present in the absence of Bi 2 O 3 , Sb 2 O 3 , and Tl 2 O, Ag 2 O will range 13-25; and (e) when present in the absence of Ag 2 O, Bi 2 O 3 , and Sb 2 O 3 , Tl 2 O will range 11-25.

Claim 3

A glass according to claim 1 consisting essentially of: ______________________________________ P.sub.2 O.sub.5 25-35 SrO 0-20 ZnO 0-35 BaO 0-20 Li.sub.2 O 0-10 CaO + SrO + BaO 0-20 Na.sub.2 O 0-15 Sb.sub.2 O.sub.3 0-61 K.sub.2 O 0-6 Bi.sub.2 O.sub.3 0-10 Ag.sub.2 O 0-25 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 0-61 Tl.sub.2 O 0-25 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 7-76 Ag.sub.2 O + Tl.sub.2 O Li.sub.2 O + Na.sub.2 O + K.sub.2 O + 15-25 SnO 0-2 Ag.sub.2 O + Tl.sub.2 O PbO 0-20 Al.sub.2 O.sub.3 0-3 CuO 0-3 B.sub.2 O.sub.3 0-3 CaO 0-20 Al.sub.2 O.sub.3 + B.sub.2 O.sub.3 0-5 CeO.sub.2 0-2. ______________________________________

Claim 4

A lens prepared from a glass having a composition which is essentially fluorine-free and which exhibits an annealing point between 300°-340° C., a linear coefficient of thermal expansion over the temperature interval 25°-300° C. between 135-180×10 -7 /°C., a refractive index of at least 1.65, and a weight loss after exposure to boiling water for six hours no greater than 0.33% consisting essentially, expressed in terms of mole percent on the oxide basis, of: ______________________________________ P.sub.2 O.sub.5 24-36 ZnO 0-45 Li.sub.2 O 0-15 Na.sub.2 O 0-20 K.sub.2 O 0-10 Ag.sub.2 O 0-25 Tl.sub.2 O 0-25 Li.sub.2 O + Na.sub.2 O + K.sub.2 O + Ag.sub.2 O + Tl.sub.2 O 15-30 PbO 0-20 CaO 0-20 CuO 0-5 CeO.sub.2 0-2 SrO 0-20 BaO 0-20 CaO + SrO + BaO 0-25 Sb.sub.2 O.sub.3 0-61 Bi.sub.2 O.sub.3 0-10 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 0-61 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 + Ag.sub.2 O + Tl.sub.2 O 7-76 SnO 0-5 Al.sub.2 O.sub.3 0-5 B.sub.2 O.sub.3 0-10 Al.sub.2 O.sub.3 + B.sub.2 O.sub.3 0-10 ______________________________________ with the provisos that: (a) in the absence of Sb 2 O 3 and/or Bi 2 O 3 , the total Ag 2 O+Tl 2 O will range 11-25; (b) in the absence of Ag 2 O and/or Tl 2 O, the total Sb 2 O 3 +Bi 2 O 3 will range 714 61; (c) when present in the absence of Bi 2 O 3 and/or Ag 2 O and/or Tl 2 O, Sb 2 O 3 will range 10-61 and, when present in the absence of Sb 2 O 3 and/or Ag 2 O and/or Tl 2 O 3 will range 7-10; (d) when present in the absence of Bi 2 O 3 , Sb 2 O 3 , and Tl 2 O, Ag 2 O will range 13-25; and (e) when present in the absence of Ag 2 O, Bi 2 O 3 , and Sb 2 O 3 , Tl 2 O will range 11-25.

Claim 5

A lens prepared from a glass having a composition which is essentially fluorine-free and which exhibits an annealing point between 300°-340° C., a linear coefficient of thermal expansion over the temperature interval 25°-300° C. between 135-180×10 -7 /°C., a refractive index of at least 1.65, and a weight loss after exposure to boiling water for six hours no greater than 0.33% consisting essentially, expressed in terms of mole percent on the oxide basis, of: ______________________________________ P.sub.2 O.sub.5 24-36 ZnO 0-45 Li.sub.2 O 0-15 Na.sub.2 O 0-20 K.sub.2 O 0-10 Ag.sub.2 O 0-25 Tl.sub.2 O 0-25 Li.sub.2 O + Na.sub.2 O + K.sub.2 O + Ag.sub.2 O + Tl.sub.2 O 15-30 PbO 0-20 CaO 0-20 CuO 0-5 CeO.sub.2 0-2 SrO 0-20 BaO 0-20 CaO + SrO + BaO 0-25 Sb.sub.2 O.sub.3 0-61 Bi.sub.2 O.sub.3 0-10 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 0-61 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 + Ag.sub.2 O + Tl.sub.2 O 7-76 SnO 0-5 Al.sub.2 O.sub.3 0-5 B.sub.2 O.sub.3 0-10 Al.sub.2 O.sub.3 + B.sub.2 O.sub.3 0-10 ______________________________________ with the provisos that: (a) in the absence of Sb 2 O 3 and/or Bi 2 O 3 , the total Ag 2 O+Tl 2 O will range 11-25; (b) in the absence of Ag 2 O and/or Tl 2 O, the total Sb 2 O 3 +Bi 2 O 3 will range 714 61; (c) when present in the absence of Bi 2 O 3 and/or Ag 2 O and/or Tl 2 O, Sb 2 O 3 will range 10-61 and, when present in the absence of Sb 2 O 3 and/or Ag 2 O and/or Tl 2 O 3 will range 7-10; (d) when present in the absence of Bi 2 O 3 , Sb 2 O 3 , and Tl 2 O, Ag 2 O will range 13-25; and (e) when present in the absence of Ag 2 O, Bi 2 O 3 , and Sb 2 O 3 , Tl 2 O will range 11-25.

Claim 6

A lens according to claim 3 prepared from a glass having a composition consisting essentially of: ______________________________________ P.sub.2 O.sub.5 25-35 SrO 0-20 ZnO 0-35 BaO 0-20 Li.sub.2 O 0-10 CaO + SrO + BaO 0-20 Na.sub.2 O 0-15 Sb.sub.2 O.sub.3 0-61 K.sub.2 O 0-6 Bi.sub.2 O.sub.3 0-10 Ag.sub.2 O 0-25 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 0-61 Tl.sub.2 O 0-25 Sb.sub.2 O.sub.3 + Bi.sub.2 O.sub.3 7-76 Ag.sub.2 O + Tl.sub.2 O Li.sub.2 O + Na.sub.2 O + K.sub.2 O + 15-25 SnO 0-2 Ag.sub.2 O + Tl.sub.2 O PbO 0-20 Al.sub.2 O.sub.3 0-3 CuO 0-3 B.sub.2 O.sub.3 0-3 CaO 0-20 Al.sub.2 O.sub.3 + B.sub.2 O.sub.3 0-5 CeO.sub.2 0-2. ______________________________________