Marble-like glass ceramic

• US 5,403,664 A
• Filed: 05/10/1993
• Issued: 04/04/1995
• Est. Priority Date: 05/11/1992
• Status: Expired due to Fees

• Current Assignee: Nippon Electric Glass Company Limited
• Original Assignee: Nippon Electric Glass Company Limited
• Inventors: Kurahashi, Toyohide, Hashibe, Yoshio, Ninomiya, Masayuki
• Primary Examiner(s): TURNER, ARCHENE A
• Application Number:
  US08/059,833
• Time in Patent Office: 694 Days
• Field of Search: 428/15, 428/426, 65/33, 561/17, 561/18, 561/70, 561/71, 561/65, 561/72
• US Class Current: 428/426
• CPC Class Codes: C03C 10/0036 containing SiO2, Al2O3 and a divalent metal oxide as main constituents

Abstract

Marble-like glass ceramic which consists essentially of, by weight percent, 50-75% SiO₂, 1-15% Al₂ O₃, 6-16.5% CaO, 0.1-5% Li₂ O, 0-1.5% B₂ O₃, 10-17.5% CaO+Li₂ O+B₂ O₃, 2.5-12% ZnO, 0-12% BaO, 0.1-15% Na₂ O+K₂ O, and 0-10% coloring agents, said ceramic comprising β-wollastonite precipitated as a major crystal. The coloring agents comprises at least one selected from a group of Fe₂ O₃, NiO, CoO, MnO₂, Cr₂ O₃, and CuO. The marble-like glass ceramic may further comprises at least one of As₂ O₃ and Sb₂ O₃ of up to 1% as refining agents, at least one of up to 1.5% MgO and up to 1.5% SrO so as to improve meltability of the glass, and at least one of up to 1% TiO₂, up to 1% ZrO₂, and up to 1% P₂ O₅ so as to make the glass stable and less devitrifiable.

Claims

1. Marble-like glass ceramic which consists essentially of, by weight percent, 50-75% SiO₂, 1-15% Al₂ O₃, 6-16.5% CaO, 0.1-5% Li₂ O, 0-1.5% B₂ O₃, 10-17.5% CaO+Li₂ O+B₂ O₃, 2.5-12% ZnO, 0-12% BaO, 0.1-15% Na₂ O+K₂ O, and 0-10% coloring agents, said ceramic comprising β

-wollastonite precipitated as a major crystal.

2. Marble-like glass ceramic as claimed in claim 1, wherein said coloring agents comprises at least one selected from a group of Fe₂ O₃, NiO, CoO, MnO₂, Cr₂ O₃, and CuO.

3. Marble-like glass ceramic as claimed in claim 1, which further comprises at least one of As₂ O₃ and Sb₂ O₃ of up to 1% as refining agents.

4. Marble-like glass ceramic as claimed in claim 1, which further comprises at least one of up to 1.5% MgO and up to 1.5% SrO so as to improve meltability of the glass.

5. Marble-like glass ceramic as claimed in claim 1, which further comprises at least one of up to 1% TiO₂, up to 1% ZrO₂, and up to 1% P₂ O₅ so as to make the glass stable and less devitrifiable.