Li
An object of the present invention is to provide a Li 2 O—Al 2 O 3 —SiO 2 based crystallized glass with excellent bubble quality even without using As 2 O 3 or Sb 2 O 3 as a fining agent and a method for producing the same. The Li 2 O—Al 2 O 3 —SiO 2 based crystallized glass of the present invention is a Li 2 O—Al 2 O 3 —SiO 2 based crystallized glass which does not substantially comprise As 2 O 3 and Sb 2 O 3 and comprises at least one of Cl, CeO 2 and SnO 2 , and has a S content of not more than 10 ppm in terms of SO 3 .
1. A Li 2 O-Al 2 O 3 —SiO 2 based crystallized glass, which does not substantially comprise As 2 O 3 and Sb 2 O, comprising:
a) not more than 100 ppm As 2 O 3 and not more than 100 ppm Sb 2 O 3 ; and
b) at least one of: 50 to 1500 ppm Cl, not more than 200 ppm CeO 2 , and 0.1 to 0.5% by mass SnO 2 ,
wherein the crystallized glass has c) a S content of 2 to 10 ppm in terms of SO 3 and (d) a β-OH value of 0.2/mm or more.
2. The Li 2 O—Al 2 O 3 —SiO 2 based crystallized glass according to claim 1 , which comprises Cl in an amount of from 200 to 1,500 ppm.
3. The Li 2 O—Al 2 O 3 —SiO 2 based crystallized glass according to claim 1 , which does not substantially comprise CeO 2 and comprises SnO 2 in an amount of from 0.1 to 0.5% by mass.
4. The Li 2 O—Al 2 O 3 —SiO 2 based crystallized glass according to claim 1 , which comprises from 50 to 80% of SiO 2 , from 12 to 30% of Al 2 O 3 , from 1 to 6% of Li 2 O, from 0 to 5% of MgO, from 0 to 10% of ZnO, from 0 to 8% of BaO, from 0 to 5% of Na 2 O, from 0 to 10% of K 2 O, from 0 to 8% of TiO 2 , from 0 to 7% of ZrO 2 , and from 0 to 7% of P 2 O 5 , in terms of a percentage by mass.
5. The Li 2 O—Al 2 O 3 —SiO 2 based crystallized glass according to claim 4 , which comprises from 20.5 to 30% by mass of Al 2 O 3 and from 0.1 to 0.5% by mass of SnO 2 and satisfies a relation of 3.7≦Li 2 O+0.741MgO+0.367ZnO<4.5 in terms of a mass ratio.
6. The Li 2 O—Al 2 O 3 —SiO 2 based crystallized glass according to claim 3 , which comprises from 50 to 80% of SiO 2 , from 12 to 30% of Al 2 O 3 , from 1 to 6% of Li 2 O, from 0 to 5% of MgO, from 0 to 10% of ZnO, from 0 to 8% of BaO, from 0 to 5% of Na 2 O, from 0 to 10% of K 2 O, from 0 to 8% of TiO 2 , from 0 to 7% of ZrO 2 , and from 0 to 7% of P 2 O 5 in terms of a percentage by mass.
7. The Li 2 O—Al 2 O 3 —SiO 2 based crystallized glass according to claim 6 , which comprises from 20.5 to 30% by mass of Al 2 O 3 and from 0.1 to 0.5% by mass of SnO 2 and satisfies a relation of 3.7<Li 2 O+0.741 MgO+0.367 ZnO<4.5 in terms of a mass ratio.