Patent ID: 11932570
Assignee: SCHOTT GLASS TECHNOLOGIES (SUZHOU) CO. LTD.
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  Y | IPC C

Claim 0:
1. A method for chemical toughening an ultrathin glass article without resultant Optical Orange Skin (OOS), comprising:
providing the ultrathin glass article that has a thickness of at most 0.07 mm;
immersing the ultrathin glass article into a bath of molten salt having a toughening temperature for a toughening time to form an ultrathin toughened glass article;
lifting the ultrathin toughened glass article out of the bath of molten salt while preventing sections of the ultrathin toughened glass article emerging from the bath of molten salt from cooling below a set dwelling temperature that is higher than or equal to the toughening temperature and lower than a transition temperature (Tg) of the ultrathin toughened glass article and so a uniform layer of residual salt forms on a surface of the ultrathin toughened glass article;
dwelling the ultrathin toughened glass article with the uniform layer of residual salt for a dwelling time in a range of 2 minutes to 12 minutes at the set dwelling temperature;
selecting parameters so that a thickness of the uniform layer of residual salt attached to the surface of the ultrathin toughened glass article from the immersing is less than 9/10*t, wherein t is the thickness of the ultrathin glass article; and
cooling and cleaning the ultrathin toughened glass article to remove the uniform layer of residual salt wherein the immersing, lifting, and dwelling cause the ultrathin toughened glass article to have a surface compressive stress greater than 300 MPa without OOS.