초록 ▼

The present invention is directed to the production of essentially dry alkali metal (R1) aluminofluorophosphate glasses optionally containing at least one divalent metal (R2) which exhibits a transition temperature below about 350°C., good chemical durability, resistance to weathering, and glass sta

The present invention is directed to the production of essentially dry alkali metal (R1) aluminofluorophosphate glasses optionally containing at least one divalent metal (R2) which exhibits a transition temperature below about 350°C., good chemical durability, resistance to weathering, and glass stability, and which demonstrate the capability of being molded at temperatures below 400°C. into complex shapes. The alkali metal aluminofluorophosphate glasses consist essentially, as analyzed on an atomic basis, between about R1AlP2F2O6 and R13.75AlP3F4O9 with the requirement that the components comply with the following atomic ratios: F:Al >2 but 2 but 1:P >0.5 but 0.75 but 12O 13-38 Al2O3 16-23 P2O5 46-64 F 17-23.

대표청구항 ▼

An essentially dry alkali metal (R1) aluminofluorophosphate glass exhibiting a relatively high viscosity at the liquidus, a low crystallization rate at the liquidus, a transition temperature below 350°C., at least a “B”rating in a weathering test procedure comprising exposure for one week in an atmo

An essentially dry alkali metal (R1) aluminofluorophosphate glass exhibiting a relatively high viscosity at the liquidus, a low crystallization rate at the liquidus, a transition temperature below 350°C., at least a “B”rating in a weathering test procedure comprising exposure for one week in an atmosphere of 98% relative humidity at 50°C., a weight loss of less than 2 mg/cm2 after immersion for one hour in distilled water at a temperature of 95°C., and demonstrating a viscosity no greater than about 109 poises at temperatures below 400°C., thereby displaying the capability of being molded at temperatures below 400°C. into complex shapes, which consists essentially, as analyzed on an atomic basis, between about R1AlP2.0F2.0O6 and R13.75AlP3.0F4.0O9, and wherein said components are present in the following atomic ratios: F:Al >2 but 4 P:Al >2 but 3 R1:P >0.5 but 1.25 An essentially dry alkali metal (R1) aluminofluorophosphate glass also containing at least one divalent metal oxide (R2) selected from the group of PbO, ZnO, CdO, MgO, CaO, SrO, and BaO which exhibits a relatively high viscosity at the liquidus, a low crystallization rate at the liquidus, a transition temperature below 350°C., at least a “B”rating in a weathering test procedure comprising exposure for one week in an atmosphere of 98% relative humidity at 50°C., a weight loss of less than 2 mg/cm2 after immersion for one hour in distilled water at a temperature of 95°C., and demonstrates a viscosity no greater than about 109 poises at temperatures below 400°C., thereby displaying the capability of being molded at temperatures below 400°C. into complex shapes, which consists essentially, as analyzed on an atomic basis, between about R10.75R20.25AlPF2O4 and R11.25R22.5AlP5.5F5O16, and wherein said components are present in the following atomic ratios: ________________________________ -F:Al >2 but 1 but 1:P >0.25 but 0.25 but 1 +R2):P <1 ________________________________