Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
119 words
A borosilicate glass composition suitable for use as an eyeglass lens, characterized by having a refractive index nd of about 1.58-1.60, an Abbe number vd>50, a density ρ≦2.75 g/cm 3 , and an excellent aptitude for chemical hardening, consisting essentially of the following composition, in weight percent: ______________________________________
SiO.sub.2 51-65
B.sub.2 O.sub.3 2-14
Al.sub.2 O.sub.3 0-5
SiO.sub.2 + B.sub.2 O.sub.3 + Al.sub.2 O.sub.3
62-73
Li.sub.2 O 6-13
Na.sub.2 O 0-4
K.sub.2 O 0-4
Li.sub.2 O + Na.sub.2 O + K.sub.2 O
7-15
CaO 1-19
MgO 0-11
CaO + MgO 6-22
TiO.sub.2 0-8
ZrO.sub.2 0-9.
TiO.sub.2 + ZrO.sub.2 being present in an amount sufficient to exhibit
said refractive index, Abbe number, and density ranges; and
ZnO up to 2.5
______________________________________
Claim 2
Dependent Claim
119 words
A borosilicate glass composition suitable for use as an eyeglass lens, characterized by having a refractive index nd of about 1.58-1.60, an Abbe number vd>50, a density ρ≦2.75 g/cm 3 , and an excellent aptitude for chemical hardening, consisting essentially of the following composition, in weight percent: ______________________________________
SiO.sub.2 51-65
B.sub.2 O.sub.3 2-14
Al.sub.2 O.sub.3 0-5
SiO.sub.2 + B.sub.2 O.sub.3 + Al.sub.2 O.sub.3
62-73
Li.sub.2 O 6-13
Na.sub.2 O 0-4
K.sub.2 O 0-4
Li.sub.2 O + Na.sub.2 O + K.sub.2 O
7-15
CaO 1-19
MgO 0-11
CaO + MgO 6-22
TiO.sub.2 0-8
ZrO.sub.2 0-9.
TiO.sub.2 + ZrO.sub.2 being present in an amount sufficient to exhibit
said refractive index, Abbe number, and density ranges; and
ZnO up to 2.5
______________________________________
Claim 3
Dependent Claim
75 words
Glass according to claim 1, having a density of 2.50-2.75 g/cm 3 and being further characterized by the following composition, in weight percent: ______________________________________
SiO.sub.2 58-64
B.sub.2 O.sub.3 4-9
Al.sub.2 O.sub.3 0-3
SiO.sub.2 + B.sub.2 O.sub.3 + Al.sub.2 O.sub.3
66-73
Li.sub.2 O 8-13
Na.sub.2 O 0-2
K.sub.2 O 0-2
Li.sub.2 O + Na.sub.2 O + K.sub.2 O
10-13.5
MgO 0-6
CaO 7-14
MgO + CaO 9-17
TiO.sub.2 1.5-7
ZrO.sub.2 1-6
TiO.sub.2 + ZrO.sub.2
4-8.
______________________________________
Claim 4
Dependent Claim
19 words
Glass according to claim 1 or 2, containing 8-13 weight percent Li 2 O and 0.5-2.5 weight percent ZnO.
Claim 5
Dependent Claim
13 words
Glass according to claim 1 or 2, further comprising 0.5-9 weight percent SrO.
Claim 6
Dependent Claim
15 words
Glass according to claim 1 or 2, further comprising at least 0.5 weight percent BaO.
Claim 7
Dependent Claim
13 words
Glass according to claim 1 or 2, further comprising 0.5-6 weight percent PbO.
Claim 8
Dependent Claim
15 words
Glass according to claim 1 or 2, further comprising at least 0.5 weight percent MgO.
Claim 9
Dependent Claim
11 words
Glass according to claim 1 or 2, wherein SrO+BaO+ZnO+PbO=10 weight percent.
Claim 10
Dependent Claim
17 words
Glass according to claim 1 or 2, further comprising 0.5-8 weight percent La 2 O 3 .
Claim 11
Dependent Claim
29 words
Glass according to claim 9, wherein La 2 O 3 is substituted wholly or partially on a molar basis by at least one other optically suitable rare earth oxide.
Claim 12
Dependent Claim
17 words
Glass according to claim 1 or 2, further comprising 0.5-7 weight percent Nb 2 O 5 .
Claim 13
Dependent Claim
15 words
Glass according to claim 1 or 2, further comprising 0.5-5 weight percent WO 3 .
Claim 14
Dependent Claim
17 words
Glass according to claim 1 or 2, further comprising 0.5-3 weight percent Ta 2 O 5 .
Claim 15
Dependent Claim
17 words
Glass according to claim 1 or 2, further comprising 0.5-5 weight percent P 2 O 5 .
Claim 16
Dependent Claim
20 words
Glass according to claim 1 or 2, wherein 0.5-3 weight percent of the oxygen ions are substituted by fluoride ions.