Drawing laminated polarizing glasses
AssigneeCorning Glass Works
InventorsWilliam P. Lentz, Thomas P. Seward, III, George C. Shay
Life of this patent
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Abstract
A method is set forth for making polarizing glasses having high dichroic ratios by drawing relatively small silver-containing particles under relatively high stress and elongating such particles during the drawing process without rupturing the glass draw by coating the polarizing glass with a substantially low viscosity skin glass.
Claims12
A method of making a polarizing glass including the steps of providing a core glass having silver-containing particles, cladding said core glass with a skin glass to form a laminated glass, said skin glass having a viscosity, when at the softening point temperature of the core glass, which is at least 50% less than that of the core glass, stretching the laminated glass at a temperature above the annealing point temperature of said core glass, at or above the softening point temperature of the skin glass, and at tensile stresses within the core glass exceeding 2000 psi, and elongating said silver-containing particles to an aspect ratio of at least 2:1 so as to provide a polarizing glass having a haze level suitably low for optical and ophthalmic applications.
A method of drawing polarizing glasses and elongating silver-containing particles within such glasses under substantially high tensile stresses while inhibiting and virtually eliminating breakage of the glass during the drawing process which comprises, providing a core glass having silver-containing particles therewithin, covering the surface of said core glass with a skin glass having a viscosity lower than that of said core glass at the softening point temperature of said core glass and forming a laminated glass, drawing and stretching the laminated glass at a temperature and rate such that the core glass is subjected to tensile stresses in excess of 10,000 psi, maintaining the skin glass at a temperature above its softening point temperature and the core at a temperature above its annealing point temperature during the stretching of the laminated glass to protect the surface of the core glass and inhibit the breakage thereof, and elongating said silver-containing particles to an aspect ratio of at least 2:1 so as to provide a high dichroic ratio.
Dependencies are inferred from the claim text.