Method of making high energy beam sensitive glasses

A method for making a high energy beam-sensitive (HEBS) glass article, said glass article comprising an integral ion-exchanged surface layer (IIES layer) having silver ions therein, and/or silver halide-containing and/or Ag.sub.2 O-containing and/or silver ion-containing microcrystals and/or microphases therein, containing silanol groups and/or water having a concentration of more than 0.01% by weight H.sub.2 O, which comprises the steps:

• (a) contacting the surface of a parent glass article with an acidic aqueous solution containing silver ions, the parent glass article being prepared from a glass batch melt and having glass composition comprising at least one alkali metal oxide selected from the group consisting of Li.sub.2 O, Na.sub.2 O, K.sub.2 O, Cs.sub.2 O and Rb.sub.2 O, zero up to saturation of halide in the glass melt, and SiO.sub.2, the glass composition containing an effective amount of photosensitivity inhibitors to suppress and/or eliminate photo reduction of said silver ions and/or said silver halide containing and/or said Ag.sub.2 O-containing and/or said silver ion containing microcrystals and/or microphases in said IIES layer, and to render the IIES layer substantially photoinsensitive to substantially all actinic radiation having a wavelength longer than 400 nm,
• (b) heating said parent glass article together with said actinic aqueous solution containing silver ions in contact therewith to reaction temperatures sufficient to effect an exchange of silver ions for said alkali metal ions in the surface of said parent glass article for a period of time sufficient to allow the ion exchange reactions to proceed up to 10 micrometer in thickness dimension into the surface of said parent glass article to form the IIES layer.

A method for making a high energy beam-darkened integral ion exchanged surface layer capable of data storage using bit by bit heat-erasure mode of recording, prior to darkening by exposure to a high energy beam, the undarkened integral ion exchanged surface layer (IIES layer) having silver ions therein and/or silver halide containing and/or Ag.sub.2 O-containing and/or silver ion-containing microcrystals and/or microphases therein, containing silanol groups and/or water having a concentration of more than 0.01% by weight H.sub.2 O, said IIES layer having a thickness of less than 10 micrometers and the darkened IIES layer having an information bearing optical density of more than 1.2 for at least one wavelength, which comprises the steps:

• (a) contacting the surface of a parent glass article with an acidic aqueous solution containing silver ions, the parent glass article being prepared from a glass batch melt and having glass composition comprising at least one alkali metal oxide selected from the group consisting of Li.sub.2 O, Na.sub.2 O, K.sub.2 O, Cs.sub.2 O and Rb.sub.2 O, zero up to saturation of halide in the glass melt, and SiO.sub.2, the glass composition containing an effective amount of photosensitivity inhibitors to suppress and/or eliminate photo reduction of said silver ions and/or said silver halide containing and/or said Ag.sub.2 O-containing and/or said silver ion containing microcrystals and/or microphases in said IIES layer, and to render the IIES layer substantially photoinsensitive to substantially all actinic radiation having a wavelength longer than 400 nm,
• (b) heating said parent glass article together with said acidic aqueous solution containing silver ions in contact therewith to reaction temperatures to effect an exchange of silver ions for said alkali metal ions in the surface of said parent glass article for a period of time sufficient to allow the ion exchange reactions to proceed to less than 10 micrometers in thickness dimension into the surface of said parent glass article to form the IIES layer, and
• (c) darkening said IIES layer to an optical density of more than 1.2 for at least one wavelength using the high energy beam.