Nippon Sheet Glass Company, Limited

Koichi Ataka

Nobuyuki Yamamoto

Akihiro Koyama

Yasuhiro Saito

Junji Kurachi

Kazuishi Mitani

Yoshihiro Matsuno

Akira Fujisawa

Yasuto Sakai

A glass substrate for use as an information recording medium has an average surface roughness (Ra) in the range of 0.3 nm&lE;Ra<3.0 nm and includes surface irregularities shaped and distributed isotropically and arranged substantially in succession. The surface irregularities include 5 to 50,000 convexities having a height of at least 3 nm and no convexities having a height of at least 15 nm within an area of 50 &mgr;m&times;50 &mgr;m. A porous region produced by an acid treatment process in the glass substrate would be completely removed if excessively etched by an alkaline solution. However, the etching process using the alkaline solution can be stopped at a stage where the pores in the porous region are enlarged by controlling conditions for the acid and alkali treatment processes.

Glass substrate for use as information recording medium and method of manufacturing such glass substrate

Method of manufacturing glass substrate for use as information recording medium

A glass substrate for an information recording medium has an acid resistance represented by an etching rate of at most 45 nm/min. upon contact with a hydrofluoric acid having a temperature of 50&deg; C. and a concentration of 0.1 weight %. The glass substrate has a recording surface having an average surface roughness Ra smaller than 0.3 nm.

Glass substrate for information recording medium, manufacturing method thereof, and information recording medium

Hydrofluoric acid etched substrate for information recording medium

A heat-radiation reflective glass comprising a glass plate and a film formed on the glass plate. The film has composition comprising 65 to 96% by weight of cobalt, 2 to 25% by weight of chromium and 2 to 33% by weight of iron based on the total metal weight per unit area, and has a layer thickness of 10 nm to 70 nm. In another embodiment, the film has composition comprising cobalt, chromium and iron in weight percentages whithin the ranges of 65 to 96% by weight of cobalt, 2 to 25% by weight of chromium and 2 to 33% by weight of iron based on the total metal weight per unit area, in its part on the side coming into contact with the glass plate, and in weight percentages within the ranges that fulfill at least one of conditions i) 2 to 96% by weight of cobalt, 2 to 8% by weight or 18 to 96% by weight of chromium and 2 to 96% by weight of iron and ii) 2 to 96% by weight of cobalt, 2 to 96% by weight of chromium and 2 to 10% by weight of iron based on the total metal weight per unit area, in its part on the outermost side, and has a layer thickness of 10 nm to 70 nm.

Heat-radiation reflective glass

Coated glass for buildings

Growing community of inventors

Osaka, Japan

Koichi Ataka