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

Claim 19:
20. A method for chemical toughening an ultrathin glass article without 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 so that there is a residual salt layer coating a surface of the ultrathin toughened glass article;
dwelling the ultrathin toughened glass article with the residual salt layer for a dwelling time at a dwelling temperature that is higher than a melting point of the bath of molten salt and lower than a transition temperature (Tg) of the ultrathin toughened glass article, wherein the dwelling temperature is higher than the toughening temperature;
selecting parameters so that a thickness of the residual salt layer 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 residual salt layer,
wherein the immersing, lifting, and dwelling cause the ultrathin toughened glass article to have a surface compressive stress greater than 300 MPa without OOS.