Nippon Sheet Glass Company, Limited

Avanstrate Inc.

Other

Shoichi Kishimoto

Akihiro Koyama

Nobuyuki Yamamoto

Junji Kurachi

Hiroyuki Tanaka

Yukihito Nagashima

Haruki Niida

Koichi Sakaguchi

Shigekazu Yoshii

Shigeki Nakagaki

Masahiro Tsuda

Masahiro Nakatsuka

Yasushi Fujimoto

A glass composition which is reduced in the amount of residual bubbles and is produced using smaller amounts of an environmentally unfriendly component such as arsenic oxide and antimony oxide. This glass composition contains, in terms of mass %: 40-70% SiO; 5-20% BO; 10.25% AlO; 0-10% MgO; 0-20% CaO; 0-20% SrO; 0-10% BaO; 0-0.5% LiO; 0-1.0% NaO; 0-1.5% KO; and 0-1.5%, excluding 0%, Cl, LiO+NaO+KO exceeding 0.06%. The glass composition can be produced suitably using, for example, a chloride as part of the raw glass materials.

Glass composition and process for producing glass composition

A glass composition which is reduced in the amount of residual bubbles and is produced using smaller amounts of an environmentally unfriendly component such as arsenic oxide and antimony oxide. This glass composition contains, in terms of mass %: 40-70% SiO; 5-20% BO; 10-25% AlO; 0-10% MgO; 0-20% CaO; 0-20% SrO; 0-10% BaO; 0-0.5% LiO; 0-1.0% NaO; 0-1.5% KO; and 0-1.5%, excluding 0%, Cl, LiO+NaO+KO exceeding 0.06%. The glass composition can be produced suitably using, for example, a chloride as part of the raw glass materials.

The present invention provides a glass composition that exhibits a fluorescence function and an optical amplification function in a wide wavelength range. This glass composition includes a bismuth oxide, a silicon oxide, an aluminum oxide, and a divalent metal oxide, and the glass composition emits fluorescence in an infrared wavelength region through irradiation of excitation light, with bismuth contained in the bismuth oxide functioning as a fluorescent source.

Glass composition that emits fluorescence in infrared wavelength region

A glass article of the present invention has a rate of dissolution in an acidic liquid of from 10 to 100 nm/min in terms of etching rate in immersing in a 0.1% by weight 50&deg; C. aqueous solution of hydrofluoric acid and an average linear thermal expansion coefficient of 70&times;10 /&deg; C. or higher as measured in the range of from &minus;50&deg; C. to 70&deg; C., and the working temperature T (&deg; C.) and the liquidus temperature T (&deg; C.) thereof satisfy the relationship: T &minus;T &gE;&minus;100&deg; C.

Glass article and glass substrate for information recording media using the same

A glass composition is disclosed which has a high modulus of elasticity and a low density, i.e., has a high specific modulus. Also disclosed is an inexpensive glass composition which is suitable for use as an information recording medium substrate, for example, because it can be formed easily, is less apt to suffer devitrification, is suitable for mass production, and can be easily made to have high surface smoothness by polishing. The glass compositions comprise, in terms of mol %, 35 to 45% silicon dioxide (SiO ), 15 to 20% aluminum oxide (Al O ), 3 to 10% lithium oxide (Li O), 0.1 to 5% sodium oxide (Na O), 15 to 30% magnesium oxide (MgO), 0 to 10% calcium oxide (CaO), 0 to 4% strontium oxide (SrO), 25 to 35% RO (MgO&plus;CaO&plus;SrO), 2 to 10% titanium dioxide (TiO ), 0.5 to 4% zirconium oxide (ZrO ), 4 to 12% TiO &plus;ZrO , and 0 to 4% yttrium oxide (Y O ).

Glass composition, and information recording medium substrate, information recording medium, and information recording device each comprising the composition

A glass composition having a high Young's modulus and a low density is disclosed which can be mass-produced by a continuous process and easily made to have high surface smoothness. Also disclosed are a substrate including the glass composition and reduced in bending and resonance even upon high-speed rotation, a recording medium usable at a lower flying height, and an information recording device having a higher recording capacity and a shorter access time. The glass composition includes, in terms of mol %, 40 to 55% silicon dioxide (SiO ), 0.5 to 6% aluminum oxide (Al O ), 2 to 20% lithium oxide (Li O), 0 to 10% sodium monoxide ((Na O), 2 to 30% R O (R O&equals;Li O&plus;Na O), 5 to 25% magnesium oxide (MgO), 0 to 25% calcium oxide (CaO), 0 to 10% strontium oxide (SrO), 10 to 40% RO (RO&equals;MgO&plus;CaO&plus;SrO), 0 to 10% titanium dioxide (TiO ), and 0 to 5% zirconium oxide (ZrO ).

Glass composition and substrate for information recording medium

A glass composition is disclosed which has a high modulus of elasticity (Young's modulus) and a high rigidity (modulus of elasticity/specific gravity) and is capable of being effectively inhibited from bending or vibrating. Also disclosed is process for producing the glass composition. The glass composition comprises, in terms of mol %, 40 to 65% SiO , 5 to 25% Al O , 2 to 20% Li O, 0 to 9% Na O, 0 to 10% TiO , 0 to 10% ZrO , 0 to 25% MgO, 0 to 25% CaO, and 0 to 10% SrO, provided that the content of RO (RO&equals;MgO&plus;CaO&plus;SrO) is from 2 to 40% and the sum of (Li O)/2 and Na O is from 1 to 10 mol %, said glass composition further containing, as clarifiers, from 0.01 to 5 mol % SnO and up to 0.1 mol % sulfur (S) in terms of the amount of SO .

Glass composition and process for producing the same

A glass-ceramics having a high elastic modulus, processes for producing the same, and an information recording medium substrate effectively inhibited from bending or vibrating are disclosed. The glass-ceramics has a major crystalline phase which has a Mohs' hardness of 6 or higher and is constituted of crystals containing manganese (Mn).

Glass-ceramics, process for producing the same, and substrate for information recording medium, information recording medium and information recording device each using the glass-ceramics

A glass composition is disclosed which has a high modulus of elasticity (Young's modulus) and a high rigidity (modulus of elasticity/specific gravity) and is capable of being effectively inhibited from bending or vibrating. Also disclosed is a substrate for information recording media, which comprises the glass composition. The glass composition comprises the following components in terms of mol %: 50 to 64% SiO , 6 to 18% Al O , 7 to 15% Li O, 3 to 12% Na O, 0 to 2% K O, 0 to 10% TiO , 0 to 4% ZrO , 0 to 6% MgO, 0 to 9% CaO, and 0 to 6% SrO, provided that the content of RO (RO&equals;MgO&plus;CaO&plus;SrO) is from 2 to 15%.

Glass composition and substrate for information recording media comprising the same

A glass composition is disclosed which has a high modulus of elasticity (Young's modulus) and a high rigidity (modulus of elasticity/specific gravity) and is capable of being effectively inhibited from bending or vibrating. Also disclosed is a substrate for information recording media, which comprises the glass composition. The glass composition comprises the following components in terms of mol %: 40 to 60% SiO , 8 to 25% Al O , 2 to 20% Li O, 0 to 5% Na O; provided that the content of R O (R O&equals;Li O&plus;Na O) is from 2 to 20%, 0 to 10% TiO , 0 to 10% ZrO , 5 to 25% MgO, 0 to 25% CaO and 0 to 6% SrO, provided that the content of RO (RO&equals;MgO&plus;CaO&plus;SrO) is from more than 15 to 40%.

A glass composition is disclosed which has a high modulus of elasticity (Young's modulus) and a high rigidity (modulus of elasticity/specific gravity) and is capable of being effectively inhibited from bending or vibrating. Also disclosed is a substrate for information recording media which comprises the glass composition. The glass composition comprises the following components, in terms of mol %: 55 to 65% SiO,, 0.5 to less than 6% Al,O,, 12 to 22% Li,O, 0 to 5% Na,O, 0 to 10% TiO,, 0 to 3% ZrO,, 0 to 8% MgO, 0 to 18% CaO, and 0 to 6% SrO, provided that the content of RO (RO&equals;MgO&plus;CaO&plus;SrO) is 5 to 18%.

A glass composition is disclosed which has a high modulus elasticity (Young's modulus) and a high rigidity (modulus of elasticity/specific gravity) and is capable of being effectively inhibited from bending or vibrating. Also disclosed is a process for producing the glass composition. The glass composition comprises, in terms of mol %, 40 to 65% SiO,, 5 to 25% Al,O,, 2 to 20% Li,O, 0 to 9% Na,O, 0 to 10% TiO,, 0 to 10% ZrO,, 0 to 25% MgO, 0 to 25% CaO, and 0 to 10% SrO, provided that the content of RO (RO&equals;MgO&plus;CaO&plus;SrO) is from 2 to 40% and the sum of (Li,O)/2 and Na,O is from 1 to 10 mol %, said glass composition further containing, as clarifiers, from 0.01 to 5 mol % SnO,and up to 0.1 mol % sulfur (S) in terms of the amount of SO,.

A glass composition is disclosed which has a high modulus of elasticity (Young's modulus) and a high rigidity (modulus of elasticity/specific gravity) and is capable of being effectively inhibited from bending or vibrating. Also disclosed is a substrate for information recording media, which comprises the glass composition. The glass composition comprises the following components in terms of mol %: 50 to 64% SiO,, 6 to 18% Al,O,, 7 to 15% Li,O, 3 to 12% Na,O, 0 to 2% K,O, 0 to 10% TiO,, 0 to 4% ZrO,, 0 to 6% MgO, 0 to 9% CaO, and 0 to 6% SrO, provided at the content of RO (RO&equals;MgO&plus;CaO&plus;SrO) is from 2 to 15%.

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Osaka, Japan

Shoichi Kishimoto