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

Claim 26:
27. A method for chemical toughening an ultrathin glass article without avoiding Optical Orange Skin (OOS), comprising:
providing the ultrathin glass article with 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 into a dwelling space directly above the bath of molten salt and so that there is a residual salt layer coating a surface of the ultrathin toughened glass article;
controlling a temperature of the dwelling space to be at a constant dwelling temperature, the constant dwelling temperature being less than 70 degrees higher or lower than the toughening temperature; and
dwelling the ultrathin toughened glass article with the residual salt layer in the dwelling space for a dwelling time of at least 2 minutes at the constant dwelling 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, controlling and dwelling cause the ultrathin toughened glass article to have a surface compressive stress greater than 300 MPa without OOS.