Novel glass compositions

Claim 2

A glass composition consisting essentially of 75 to 82 mole percent SiO 2 , 2 to 8 mole percent ZrO 2 , 1 to 5 mole percent Al 2 O 3 , 2 to 10 mole percent Na 2 O, 2 to 10 mole percent K 2 O, 2 to 10 mole percent CaO, 2 to 10 mole percent SrO, and 2 to 10 mole percent BaO, said composition being essentially free from boron.

Claim 3

A glass composition according to claim 1 wherein said composition comprises 75 to 80 mole percent SiO 2 , 4 to 6 mole percent ZrO 2 , 1 to 3 mole percent Al 2 O 3 , 2 to 4 mole percent K 2 O, 2 to 4 mole percent Na 2 O, 2 to 6 mole percent SrO, 2 to 6 mole percent BaO, and 2 to 6 mole percent CaO.

Claim 4

A glass composition according to claim 2 wherein said composition comprises 78 mole percent SiO 2 , 5 mole percent ZrO 2 , 2 mole percent Al 2 O 3 , 2.5 mole percent Na 2 O, 2.5 mole percent K 2 O, 3.3 mole percent CaO, 3.3 mole percent SrO, and 3.3 mole percent BaO.

Claim 5

A glass composition consisting essentially of 75 to 80 mole percent SiO 2 , 2 to 6 mole percent ZrO 2 , 1 to 3 mole percent Al 2 O 3 , 0 to 6 mole percent Na 2 O, 0 to 6 mole percent K 2 O, 0 to 5 mole percent CaO, 0 to 5 mole percent SrO, and 0 to 5 mole percent BaO, and wherein the concentration of Na 2 O and K 2 O is 4 to 6 mole percent and wherein the concentration of CaO, BaO, and SrO is 8 to 12 mole percent, said composition being essentially free from boron.

Claim 6

A glass composition consisting essentially of 75 to 80 mole percent SiO 2 , 2 to 6 mole percent ZrO 2 , 1 to 3 mole percent Al 2 O 3 , 0 to 6 mole percent Na 2 O, 0 to 6 mole percent K 2 O, 0 to 5 mole percent CaO, 0 to 5 mole percent SrO, and 0 to 5 mole percent BaO, and wherein the concentration of Na 2 O and K 2 O is 4 to 6 mole percent and wherein the concentration of CaO, BaO, and SrO is 8 to 12 mole percent, said composition being essentially free from boron.

Claim 7

A glass composition consisting essentially of ______________________________________ Ingredients Mole Percent ______________________________________ SiO.sub.2 70-82 ZrO.sub.2 2-8 Al.sub.2 O.sub.3 0-5 Na.sub.2 O 0-10 K.sub.2 O 0-10 CaO 0-15 SrO 0-15 BaO 0-15 MgO 0-15 (Na.sub.2 O + K.sub.2 O) 3-10 (CaO + SrO + BaO + MgO) 2-15 ______________________________________ and wherein the concentration of (Na 2 O + K 2 O + CaO + SrO + BaO + MgO) is at least 12 mole percent, said composition being essentially free from boron.

Claim 8

A glass composition consisting essentially of ______________________________________ Ingredients Mole Percent ______________________________________ SiO.sub.2 70-82 ZrO.sub.2 2-8 Al.sub.2 O.sub.3 0-5 Na.sub.2 O 0-10 K.sub.2 O 0-10 CaO 0-15 SrO 0-15 BaO 0-15 MgO 0-15 (Na.sub.2 O + K.sub.2 O) 3-10 (CaO + SrO + BaO + MgO) 2-15 ______________________________________ and wherein the concentration of (Na 2 O + K 2 O + CaO + SrO + BaO + MgO) is at least 12 mole percent, said composition being essentially free from boron.

Claim 9

A glass composition according to claim 5 wherein said composition comprises 75 to 80 mole percent SiO 2 , 4 to 6 mole percent ZrO 2 , 2 to 3 mole percent Al 2 O 3 , 2 to 6 mole percent K 2 O, 2 to 6 mole percent Na 2 O, 4 to 6 mole percent SrO, and 4 to 6 mole percent BaO.

Claim 10

A glass composition according to claim 5 wherein said composition comprises 78 mole percent SiO 2 , 5 mole percent ZrO 2 , 2 mole percent Al 2 O 3 , 2.5 mole percent Na 2 O, 2.5 mole percent K 2 O, and 10 mole percent SrO.

Claim 11

A glass composition according to claim 5 wherein said composition comprises 78 mole percent SiO 2 , 5 mole percent ZrO 2 , 2 mole percent Al 2 O 3 , 2.5 mole percent Na 2 O, 2.5 mole percent K 2 O, 5 mole percent SrO, and 5 mole percent BaO.

Claim 12

A glass compodition according to claim 5 wherein said composition comprises 78 mole percent SiO 2 , 5 mole percent ZrO 2 , 2 mole percent Al 2 O 3 , 2.5 mole percent Na 2 O, 2.5 mole percent K 2 O, 5 mole percent CaO, and 5mole percent BaO.

Claim 13

A glass composition according to claim 5 wherein said composition comprises 78 mole percent SiO 2 , 5 mole percent ZrO 2 , 2 mole percent Al 2 O 3 , 2.5 mole percent Na 2 O, 2.5 mole percent K 2 O, 6 mole percent CaO, 2 mole percent SrO, and 2 mole percent BaO.

Claim 14

A glass composition according to claim 5 wherein said composition comprises 80 mole percent SiO 2 , 5 mole percent ZrO 2 , 5 mole percent Na 2 O, 5 mole percent MgO, and 5 mole percent CaO.

Claim 15

A glass composition according to claim 5 wherein said glass composition comprises 77 mole percent SiO 2 , 5 mole percent ZrO 2 , 3 mole percent Al 2 O 3 , 2.5 mole percent Na 2 O, 2.5 mole percent K 2 O, 3.3 mole percent CaO, 3.3 mole percent SrO, and 3.3 mole percent BaO.

Claim 16

A glass composition according to claim 5 wherein said composition comprises 78 mole percent SiO 2 , 5 mole percent ZrO 2 , 2 mole percent Al 2 O 3 , 5 mole percent Na 2 O, 3.3 mole percent CaO, 3.3 mole percent SrO, and 3.3 mole percent BaO.

Claim 17

A glass composition according to claim 5 wherein said composition comprises 80 mole percent SiO 2 , 5 mole percent ZrO 2 , 5 mole percent Na 2 O, 2 to 4 mole percent MgO, 2 to 4 mole percent CaO, and 2 to 4 mole percent SrO.

Claim 18

A glass composition consisting essentially of ______________________________________ Ingredient Mole Percent ______________________________________ SiO.sub.2 75-82 ZrO.sub.2 2-8 Al.sub.2 O.sub.3 0-5 Na.sub.2 O 0-10 K.sub.2 O 0-10 Li.sub.2 O 0-10 CaO 0-15 SrO 0-15 BaO 0-15 MgO 0-15 (Na.sub.2 O + K.sub.2 O + Li.sub.2 O) 3-10 (CaO + SrO + BaO + MgO) 2-15 ______________________________________ and wherein the concentration of (Na 2 O + K 2 O + Li 2 O + CaO + SrO + BaO + MgO) is at least 10 mole percent and wherein said glass composition contains about 1 to 3 mole percent of a member selected from the group consisting of PbO, TiO 2 and ZnO, and mixtures thereof, said composition being essentially free from boron.

Claim 19

A glass composition consisting essentially of ______________________________________ Ingredient Mole Percent ______________________________________ SiO.sub.2 75-82 ZrO.sub.2 2-8 Al.sub.2 O.sub.3 0-5 Na.sub.2 O 0-10 K.sub.2 O 0-10 Li.sub.2 O 0-10 CaO 0-15 SrO 0-15 BaO 0-15 MgO 0-15 (Na.sub.2 O + K.sub.2 O + Li.sub.2 O) 3-10 (CaO + SrO + BaO + MgO) 2-15 ______________________________________ and wherein the concentration of (Na 2 O + K 2 O + Li 2 O + CaO + SrO + BaO + MgO) is at least 10 mole percent and wherein said glass composition contains about 1 to 3 mole percent of a member selected from the group consisting of PbO, TiO 2 and ZnO, and mixtures thereof, said composition being essentially free from boron.

Claim 20

A glass composition according to claim 15 wherein said glass comprises 80 to 81 mole percent SiO 2 , 4 to 6 mole percent ZrO 2 , 2 to 3 mole percent Na 2 O, 5 to 7 mole percent CaO, 3 to 5 mole percent MgO, and 2 mole percent Li 2 O.

Claim 21

A glass composition according to claim 15 wherein said glass composition comprises 80 mole percent SiO 2 , 5 mole percent ZrO 2 , 2 to 3 mole percent Na 2 O, 4 to 5 mole percent CaO, 4 to 5 mole percent MgO, 1 to 2 mole percent BaO, 2 to 3 mole percent K 2 O, 1 mole percent Li 2 O, and 1 to 2 mole percent ZnO.

Claim 22

A glass composition consisting essentially of 75 to 82 mole percent SiO 2 , 2 to 6 mole percent ZrO 2 , 1 to 3 mole percent A1 2 O 3 , 0 to 6 mole percent Na 2 O, 0 to 6 mole percent K 2 O, 0 to 5 mole percent CaO, 0 to 5 mole percent SrO, 0 to 5 mole percent BaO, and wherein the concentration of Na 2 O and K 2 O is 4 to 6 mole percent and wherein the total concentration of CaO, BaO, and SrO is 8 to 12 mole percent, said composition being essentially free from boron.

Claim 23

A glass composition consisting essentially of 75 to 82 mole percent SiO 2 , 2 to 6 mole percent ZrO 2 , 1 to 3 mole percent A1 2 O 3 , 0 to 6 mole percent Na 2 O, 0 to 6 mole percent K 2 O, 0 to 5 mole percent CaO, 0 to 5 mole percent SrO, 0 to 5 mole percent BaO, and wherein the concentration of Na 2 O and K 2 O is 4 to 6 mole percent and wherein the total concentration of CaO, BaO, and SrO is 8 to 12 mole percent, said composition being essentially free from boron.

Claim 24

A glass consisting essentially by mole percent on the oxide basis of about 0-10 mole percent Na 2 O and/or 0-10 mole percent K 2 O, the total of Na 2 O plus K 2 O constituting 3-10 mole percent, 70-82 mole percent SiO 2 , 2-15 mole percent strontium oxide, 2-8 mole percent ZrO 2 , said Na 2 O and l or K 2 0, SiO 2 and SrO constituting at least about 74% by weight of the total composition.

Claim 25

A glass consisting essentially by mole percent on the oxide basis of about 0-10 mole percent Na 2 O and/or 0-10 mole percent K 2 O, the total of Na 2 O plus K 2 O constituting 3-10 mole percent, 70-82 mole percent SiO 2 , 2-15 mole percent strontium oxide, 2-8 mole percent ZrO 2 , said Na 2 O and l or K 2 0, SiO 2 and SrO constituting at least about 74% by weight of the total composition.

Claim 26

A glass according to claim 19 wherein the SrO content thereof ranges about 3-15% by weight.

Claim 27

A glass according to claim 19 wherein said composition contains up to 13% by weight BaO.

Claim 28

A glass according to claim 19 wherein said composition contains CaO, BaO, MgO or mixtures thereof, wherein the amount of said CaO, MgO, BaO, or mixtures thereof plus SrO is within the range of 2-15 mole percent.

Claim 29

A glass consisting essentially, by mole percent on the oxide basis, of about 70-82 mole percent SiO 2 , 0-10 mole percent Na 2 O, O-10 mole percent K 2 O, the total of K 2 O + Na 2 O constititing 3-10 mole percent, 2-15 mole percent SrO, and 2-8 mole percent ZrO 2 , said Na 2 O + K 2 O + SrO being at least 12 mole percent and the total of SiO 2 + Na 2 O + K 2 O + SrO constituting at least 82 mole percent of the total glass composition.

Claim 30

A glass consisting essentially, by mole percent on the oxide basis, of about 70-82 mole percent SiO 2 , 0-10 mole percent Na 2 O, O-10 mole percent K 2 O, the total of K 2 O + Na 2 O constititing 3-10 mole percent, 2-15 mole percent SrO, and 2-8 mole percent ZrO 2 , said Na 2 O + K 2 O + SrO being at least 12 mole percent and the total of SiO 2 + Na 2 O + K 2 O + SrO constituting at least 82 mole percent of the total glass composition.

Claim 31

A glass consisting essentially, by weight percent on the oxide basis, of about 65.2 to 76 percent SiO 2 , 0 to 5 percent Na 2 O, 0 to 6.7 percent K 2 O, the total of K 2 O and Na 2 O constituting from 4.4 to 6.7 percent, 3 to 15.3 percent SrO and 2.8 to 9.7 percent ZrO 2 .

Claim 32

A glass consisting essentially, by weight percent on the oxide basis, of about 65.2 to 76 percent SiO 2 , 0 to 5 percent Na 2 O, 0 to 6.7 percent K 2 O, the total of K 2 O and Na 2 O constituting from 4.4 to 6.7 percent, 3 to 15.3 percent SrO and 2.8 to 9.7 percent ZrO 2 .

Claim 33

A glass according to claim 24 wherein said composition contains up to 13% by weight BaO.

Claim 34

A glass according to claim 24 wherein said composition contains up to 6% by weight total of CaO and MgO.

Claim 35

A glass according to claim 23 wherein the SrO content thereof ranges about 3 to 15.3% by weight.

Claim 36

A glass according to claim 23 wherein said composition contains up to 13% by weight BaO.

Claim 37

A glass according to claim 23 wherein said composition contains up to 6% by weight total of CaO and MgO.