Corning Glass Works

Jean P Mazeau

Jean E Boudot

Thomas P Seward, Iii

Michel Prassas

Philippe L Courbin

David J Kerko

David L Morse

Andre C Michaud

This invention is directed to the production of glasses especially suitable for use as ophthalmic lenses which exhibit indices of refraction between about 1.699-1.703, Abbe numbers equal to or greater than 41.0, densities less than 3.25 g/cm.sup.3, and good resistance to attack by acids. The glasses are essentially free of Al.sub.2 O.sub.3 and consist essentially, in weight percent on the oxide basis, of:

Chemically durable, high index, low density glasses

This invention is concerned with a glass for optical and/or ophthalmic applications having an index of refraction between about 1.78-1.82, an Abbe number greater or equal to 31, and a density less than about 3.80 g/cm.sup.3 consisting essentially, expressed in terms of weight percent on the oxide basis, of:

Optical and ophthalmic glasses

The invention relates to the glass industry. It concerns glasses of low lead content characterized in being prepared from glass forming batches consisting essentially, in weight percent on the oxide basis of:

Low PbO-containing glass for electrical devices

This invention is concerned with the production of glasses suitable for ophthalmic applications having refractive indices of 1.523.+-.0.004, Abbe number between 51-59, densities less than 2.43 g/cm.sup.3, transmissions at 400 nm in 2 mm thickness greater than 89%, and a UV cutoff between 310-335 nm, said glasses consisting essentially, in weight percent on the oxide basis, of:

Glasses for ophthalmic applications

This invention relates to glasses especially suitable for optical and ophthalmic applications which exhibit densities less than about 2.65 g/cm.sup.3, refractive indices between about 1.595-1.607, and Abbe numbers between about 40-47, and which consist essentially, in weight percent on the oxide basis, of

Glasses of low density and high index of refraction for ophthalmic and

This invention is concerned with the preparation of moldable optical glasses having refractive indices of about 1.65-1.735, dispersions of about 38-58, transition temperatures lower than about 500.degree. C., softening points lower than about 600.degree. C., and satisfactory chemical durability consisting essentially, expressed in terms of parts by weight as calculated from the batch, of

Moldable fluoroborate optical glasses

The present invention is directed to fluorophosphate glasses containing about 3-21.5% Nb.sub.2 O.sub.5 and exhibiting softening points below 500.degree. C. The inventive glasses contemplate two general composition areas in weight percent:

Moldable fluorophosphate glasses containing Nb.sub.2 O.sub.5

This invention is directed to the production of glasses having a density of less than 3.26 g/cm.sup.3, a .beta..sub.OH value less than 0.030 mm.sup.-1, and, in a thickness of 2 mm, a transmission of at least about 80% at a wavelength of 4.0 microns and at least about 50% at a wavelength of 5 microns, which have base compositions within the alkali metal oxide-CaO-Al.sub.2 O.sub.3 -GeO.sub.2 -F and/or Cl field consisting essentially, expressed in terms of weight percent on the oxide basis, of

Germanium-containing glass of high infrared transmission and low density

The present invention is concerned with the production of photochromic glass compositions consisting essentially, expressed in terms of weight percent on the oxide basis, as calculated from the batch, of

Photochromic glass suitable for ophthalmic applications

The present invention is drawn to glasses suitable for the fabrication of segments or buttons for multifocal ophthalmic lenses. The inventive glasses have refractive indices ranging between about 1.745-1.771, an Abbe number greater than 29 for a refractive index of 1.771 and greater than 31 for a refractive index of 1.745, a softening point between about 640.degree.-700.degree. C., a coefficient of thermal expansion (25.degree.-300.degree. C.) between about 90-98.times.10.sup.-7 /.degree.C., and satisfactory chemical durability. The glasses consist essentially, expressed in terms of weight percent on the oxide basis, of

Ophthalmic glasses with high indices of refraction

The instant invention is related to the manufacture of photochromic glasses having base compositions within a very narrow interval of the alkali metal boroaluminosilicate system wherein silver chloride and/or silver bromide crystals impart photochromic properties. The glasses are notable for their rapid fading characteristics and relatively low temperature dependence of darkening. The compositions are especially suitable for a production process which contemplates simultaneously shaping articles from glass sheet and developing photochromic properties therein.

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Avon, France

Jean P Mazeau