Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
198 words
A seal glass composition for electric devices which consists essentially of in approximate percent by weight 65-75 SiO 2 , 9-13 Na 2 O, 3-6 K 2 O, 1-4 Al 2 O 3 , 4-8 CaO, 0-4 BaO, 0-6 PbO, 0-1F, and 0-2 Li 2 O along with minor amounts of incidental impurities, residual fluxes, and refining agents, and wherein the Na 2 O to K 2 O ratio lies between about 1.5 to about 4.5 with a high Na 2 O/K 2 O ratio when the CaO is high whereas the Na 2 O/K 2 O ratio is low when the CaO is low, said glass composition having a softening point in the approximate range 625°-670° C, a sealing point in the approximate range 820°-870° C, a working point in the approximate range 950°-990° C, a working range of at least 300° C, an average coefficient of linear thermal expansion in the 0°-300° C temperature range between about 87 × 10 -7 cm/cm/° C to about 97 × 10-7 cm/cm/° C, and electrical resistivity greater than 10 7 .1 ohm-cm at 250° C together with an electrical resistivity greater than 10 5 .5 ohm-cm at 350° C.
Claim 2
Dependent Claim
198 words
A seal glass composition for electric devices which consists essentially of in approximate percent by weight 65-75 SiO 2 , 9-13 Na 2 O, 3-6 K 2 O, 1-4 Al 2 O 3 , 4-8 CaO, 0-4 BaO, 0-6 PbO, 0-1F, and 0-2 Li 2 O along with minor amounts of incidental impurities, residual fluxes, and refining agents, and wherein the Na 2 O to K 2 O ratio lies between about 1.5 to about 4.5 with a high Na 2 O/K 2 O ratio when the CaO is high whereas the Na 2 O/K 2 O ratio is low when the CaO is low, said glass composition having a softening point in the approximate range 625°-670° C, a sealing point in the approximate range 820°-870° C, a working point in the approximate range 950°-990° C, a working range of at least 300° C, an average coefficient of linear thermal expansion in the 0°-300° C temperature range between about 87 × 10 -7 cm/cm/° C to about 97 × 10-7 cm/cm/° C, and electrical resistivity greater than 10 7 .1 ohm-cm at 250° C together with an electrical resistivity greater than 10 5 .5 ohm-cm at 350° C.
Claim 3
Dependent Claim
37 words
A glass composition as in claim 1 having an average coefficient of linear thermal expansion in the 0°-300° C temperature range between about 89 × 10 -7 cm/cm/° C to about 93 × 10 -7 cm/cm/° C.