Nippon Sheet Glass Company, Limited

Masashi Kikuta

Chihiro Sakai

Masayuki Maenaka

Tetsuo Minaai

Michihiro Kato

In a process for producing an air-quench-toughened glass plate, defective glass plates containing nickel sulfide (NiS) are removed by compulsory breaking the glass plates. Such compulsory breakage is carried out in the course of a batch-manner soaking process carried out after a toughening step; in the course of a toughening step carried out after generation of cracks in an annealing step; in the course of a toughening step carried out after generation of cracks in a pretreatment step; or in the course of a continuous annealing step carried out after a toughening step. Through the method, NiS-free toughened glass plates of high-quality can be produced.

Method for producing air-quench-toughened glass plate

In a process for producing an air-quench-toughened glass plate, defective glass plates containing nickel sulfide (NiS) are removed by compulsory breaking the glass plates. Such compulsory breakage is carried out in the course of a batch-manner soaking process carried out after a toughening step; in the course of a toughening step carried out after generation of cracks in an annealing step; in the course of a toughening step carried out after generation of cracks in a pretreatment step; or in the course of a continuous annealing step carried out after a toughening step. Through the method, NiS-free toughened glass plates of high quality can be produced.

A glass panel in which spacing members (,) are interposed between a pair of glass sheets (,A,,B) and a heat-fusible outer periphery sealing portion is provided along the entire outer periphery of the two glass sheets (,A,,B) for sealing the space (V) between the glass sheets (,A,,B) under a pressure-reduced condition. A linear expansion coefficient (&agr;,) of one (,A) of the glass sheets (,A,,B) and a linear expansion coefficient (&agr;,) of the other glass sheet (,B) are set within a range which satisfies a predetermined relation expression.

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Osaka, Japan

Masashi Kikuta