Ophthalmic glass compositions

Details Ophthalmic glass compositions Ophthalmic glass compositions

1974-11-29

1976-04-20

McCarthy, Helen M.

Compositions: coating or plastic

Coating or plastic compositions

Metal-depositing composition or substrate-sensitizing...

65 30E, 106 54, C03C 304, C03C 308, C03C 2322

Patent

active

039516717

ABSTRACT:
Ophthalmic glass compositions suitable for toughening by the known ion-exchange process have a composition in weight percentages of: SiO.sub.2 58 to 67% Al.sub.2 O.sub.3 4.5 to 8.0% Na.sub.2 O 8.5 to 17% K.sub.2 O 2 to 11% ZnO 0 to 10% ZrO.sub.2 0 to 6.5% TiO.sub.2 0 to 5.0% As.sub.2 O.sub.3 0 to 1% Sb.sub.2 O.sub.3 0 to 1% B.sub.2 O.sub.3 0 to 6%
The total of the foregoing constituents amounting to at least 95% of the composition and the balance, if any, being composed of compatible constituents; the composition including an effective amount of either one or both of ZnO and ZrO.sub.2, to promote ion penetration in an ion-exchange toughening process, either one or both of ZrO.sub.2 and TiO.sub.2 being present; the total of Na.sub.2 O + K.sub.2 O being not more than 22%; B.sub.2 O.sub.3 being present when the total of Al.sub.2 O.sub.3 + ZrO.sub.2 exceeds 10%; and the total of ZrO.sub.2 + TiO.sub.2, when TiO.sub.2 is present, being not more than 5.5%. Refractive index n.sub.d is close to the standard value of 1.523 and good penetration of the ion exchange is achieved in toughening, while the expansion coefficient makes the glass compatible with a standard flint glass in fused bi-focal lenses.

REFERENCES:
patent: 2779136 (1957-01-01), Hood et al.
patent: 3357876 (1967-12-01), Rinehart
patent: 3790260 (1974-02-01), Boyd et al.

Affiliated with

Also associated with

Rating

Ophthalmic glass compositions does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Ophthalmic glass compositions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ophthalmic glass compositions will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1584396