Antiblurring glass
AssigneeHoya Corporation
InventorToshiharu Yamashita
Life of this patent
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Abstract
A glass for use as an optical glass having an anti-blurring property, water resistance and hardness and decreased liquidus temperature, said glass consisting essentially of, in mol. %, 47 to 65% P.sub.2 O.sub.5, 0.5 to 12% SiO.sub.2, 0.5 to 10% B.sub.2 O.sub.3, 6 to 15% SiO.sub.2 +B.sub.2 O.sub.3, 0 to 30% alkali metal oxide, 5 to 35% alkaline earth metal oxide, 20 to 45% alkali metal oxide+alkaline earth metal oxide, 0 to 5% Al.sub.2 O.sub.3, 0 to 10% ZnO, and no PbO. Oxides of Ce, Nd and Er may also be present.
Claims3
A glass for use as an optical glass having an antiblurring property, water resistance and hardness and decreased liquidus temperature, said glass consisting essentially of the following ingredients in mol %.
- ______________________________________ P.sub.2 O.sub.5 51.4 to 61.0 B.sub.2 O.sub.3 1.0 to 8.3 SiO.sub.2 1.0 to 11.5 SiO.sub.2 + B.sub.2 O.sub.3 6.0 to 15.0 MgO 0 to 25.0 CaO 0 to 30.0 SrO 0 to 25.0 Li.sub.2 O 0 to 15.0 Na.sub.2 O 0 to 16.7 K.sub.2 O 0 to 5.0 BaO 0 to 14.0 ZnO 0 to 5.0 Al.sub.2 O.sub.3 0 to 1.0 Li hd 2 O + Na.sub.2 O + K.sub.2 O 0 to 30.0 MgO + CaO + SrO + BaO 5.0 to 35.0 MgO + CaO + SrO + BaO + Li.sub.2 O + Na.sub.2 O + K.sub.2 O 20.0 to 45.0 ______________________________________
- and having a water resistance of 0.16 to 0.45% and a knoop hardness of 410 to 465 Kg/mm.sup.2 and no PbO.
A glass for use as an optical glass having an antiblurring property, water resistance and hardness and decreased liquidus temperature, said glass consisting essentially of the following ingredients in mol %:
- ______________________________________ P.sub.2 O.sub.5 51.4 to 61.0 SiO.sub.2 1.0 to 11.5 B.sub.2 O.sub.3 1.0 to 8.3 SiO.sub.2 + B.sub.2 O.sub.3 6.0 to 15.0 Li.sub.2 O 3.3 to 8.3 SrO 0 to 25.0 BaO 0 to 14.0 ZnO 0 to 5.0 Na.sub.2 O 0 to 16.7 K.sub.2 O 0 to 5.0 MgO 0 to 25.0 CaO 0 to 30.0 Al.sub.2 O.sub.3 0 to 1.0 Li.sub.2 O + Na.sub.2 O + K.sub.2 O 3.3 to 30.0 MgO + CaO + SrO + BaO 5.0 to 35.0 MgO + CaO + SrO + BaO + Li.sub.2 O + Na.sub.2 O + K.sub.2 O 20.0 to 45.0 and per 100 parts by mole of the above there is present in parts by mole:
- CeO.sub.2 0.15 to 0.6 and Nd.sub.2 O.sub.3 0 to 1.5 or Er.sub.2 O.sub.3 0 to 0.5 ______________________________________
- and having a water resistance of 0.10 to 0.32%, a knoop hardness of 423 to 472 Kg/mm.sup.2, a .lambda.T5 of 306 to 320 mm and a refractive index (nd) of 1.514 to 1.532 and no PbO.
Dependencies are inferred from the claim text.