Asahi Glass Company, Limited

Takashi Kijima

Yusuke Takei

Masataka Matsuwaki

Michito Sasaki

Atsushi Tanigaki

Toru Kudo

Mizuki Ito

Mizuki Sasage

Toshiyasu Kawaguchi

Toshihiro Ishino

Shiro Tanii

Akira Kondo

Katsuharu Imamaki

Fumio Kamei

Takayuki Kobayashi

Yasuharu Hirabara

Mitsuo Sugimoto

Setsuko Mita

Takaaki Sera

Jyun Matsui

Shunji Takakusa

Hiroshi Ogata

Mizuki Itoh

A vacuum degassing apparatus for molten glass according to the present invention comprises a vacuum housing where a vacuum is created; a vacuum degassing vessel housed in the vacuum housing to degas the molten glass; an introduction device communicated to the vacuum degassing vessel so as to introduce untreated molten glass into the vacuum degassing vessel, or preferably an uprising pipe; and a discharge device to discharge treated molten glass from the vacuum degassing vessel, or preferably a downfalling pipe. In the apparatus, at least a portion of at least one of the vacuum degassing vessel, the uprising pipe and the downfalling pipe that directly contact with the molten glass is constituted by refractory material having a porosity of not greater than 5%. The apparatus can increase quantity of flow of the molten glass and consequently a degassing throughput of the molten glass in comparison with prior art, having the same size and the same pressure loss. The apparatus can further increase the quantity of flow and the degassing throughput without making the size of the apparatus excessively larger.

Vacuum degassing apparatus for molten glass

A vacuum degassing apparatus includes a lifter to absorb deformation in a vertical direction due to thermal expansion of the vacuum degassing, a slider to absorb thermal expansion of the vacuum degassing vessel in a longitudinal direction thereof, or a thermal expansion absorbing layer to absorb thermal expansion of an uprising pipe and a downfalling pipe in a cross-sectional direction, or a thermal expansion absorbing layer provided along a portion of an outer surface of the vacuum degassing vessel in a height direction.

A vacuum degassing method for molten glass, which comprises introducing molten glass into a vacuum degassing apparatus, subjecting it to degassing treatment under a predetermined reduced pressure condition and then withdrawing it for a subsequent step, wherein during the degassing treatment, a metal compound which is at least one compound of metal selected from the group consisting of aluminum, titanium, silicon, zinc, magnesium, iron, chromium, cobalt, cerium and calcium, is supplied from outside of the vacuum degassing apparatus to the surface of a bubble layer formed in the molten glass to diminish or extinguish the bubble layer.

Vacuum degassing method for molten glass

A vacuum degassing apparatus for molten glass includes a vacuum housing where a vacuum is created; a vacuum degassing vessel housed in the vacuum housing to degas the molten glass; an introduction device communicated to the vacuum degassing vessel so as to introduce untreated molten glass into the vacuum degassing vessel, or preferably an uprising pipe; and a discharge device to discharge treated molten glass from the vacuum degassing vessel, or preferably a downfalling pipe. In the apparatus, at least a portion of at least one of the vacuum degassing vessel, the uprising pipe and the downfalling pipe that directly contact the molten glass is constituted by refractory material having a porosity of not greater than 5%. The apparatus can increase quantity of flow of the molten glass and consequently a degassing throughput of the molten glass, having the same size and the same pressure loss. The apparatus can further increase the quantity of flow and the degassing throughput without making the size of the apparatus excessively larger.

Dark green colored glass

Ultraviolet ray absorbing colored glass, which comprises 100 parts by weight of a base component consisting of soda lime silicate glass and coloring components consisting essentially of from 0.08 to 0.4 part by weight of total iron as calculated as Fe.sub.2 O.sub.3, from 0.05 to 0.4 part by weight of vanadium as calculated as V.sub.2 O.sub.5, from 0.0005 to 0.03 part by weight of Se, from 0 to 0.005 part by weight of CoO, from 0 to 2.0 parts by weight of TiO.sub.2 and from 0 to 0.8 part by weight of CeO.sub.2.

Ultraviolet ray absorbing colored glass

A dark gray colored glass comprising 100 parts by weight of a soda lime silicate glass as a matrix component and coloring components consisting essentially of from 0.8 to 1.5 parts by weight of total iron calculated as Fe.sub.2 O.sub.3, from 0.1 to 0.3 part by weight of FeO, from 0 to 1.0 part by weight of TiO.sub.2, from 0.0005 to 0.015 part by weight of Se, from 0.02 to 0.05 part by weight of CoO and from 0.002 to 0.05 part by weight of Cr.sub.2 O.sub.3.

Dark gray colored glass

Glass having low solar radiation and ultraviolet ray transmittance, which consists essentially of a soda lime-silica type matrix glass containing from 0.53 to 0.70 wt % of total iron calculated as Fe.sub.2 O.sub.3, from 0.2 to 0.4 wt % of TiO.sub.2 and from 0.5 to 0.8 wt % of total cerium calculated as CeO.sub.2, wherein the weight of FeO calculated as Fe.sub.2 O.sub.3 is from 30 to 40% of the weight of the total iron calculated as Fe.sub.2 O.sub.3.

Glass having low solar radiation and ultraviolet ray transmittance

A deep gray colored glass comprising 100 parts by weight of matrix components and coloring components consisting essentially of: from 0.8 to 1.4 parts by weight of total iron calculated as Fe.sub.2 O.sub.3, at most 0.21 part by weight of FeO, from 0.05 to 1.0 part by weight of TiO.sub.2, from 0.0005 to 0.015 part by weight of Se and from 0.02 to 0.05 part by weight of CoO, wherein the matrix components comprise from 65 to 75 wt % of SiO.sub.2, from 0.1 to 5.0 wt % of Al.sub.2 O.sub.3, from 10 to 18 wt % of Na.sub.2 O+K.sub.2 O, from 5 to 15 wt % of CaO, from 1 to 6 wt % of MgO and from 0.05 to 1.0 wt % of SO.sub.3.

Deep gray colored glass

Ultraviolet ray absorbent colored glass for buildings and vehicles, which consists essentially of from 65 to 75 wt % of SiO.sub.2, from 0.1 to 5.0 wt % of Al.sub.2 O.sub.3 , from 10 to 18 wt % of Na.sub.2 O, from 0 to 5 wt % of K.sub.2 O, from 5 to 15 wt % of CaO, from 1 to 6 wt % of MgO, from 0.05 to 1.0 wt % of SO.sub.3, from 0.08 to 0.20 wt % of vanadium as calculated as V.sub.2 O.sub.5, from 0.36 to 0.65 wt % of MnO.sub.2, from 0 to 0.0020 wt % of CoO and from 0.06 to 0.18 wt % of iron as calculated as Fe.sub.2 O.sub.3, wherein from 0 to 10 wt % of the total iron content is FeO.

Ultraviolet ray absorbent colored glass

A glass substrate for a magnetic disc having a finely and isotropically roughened surface, wherein the maximum height R.sub.max of the surface roughness is substantially not higher than 700 .ANG. at a standard length of 250 .mu.m and substantially not less than 50 .ANG. at a standard length of 50 .mu.m.

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Yokohama, Japan

Takashi Kijima