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

Claim 12:
13. A method for chemical toughening an ultrathin glass article, 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 with a controlled lifting speed of less than 0.5 m/minute so that salt residues flow off a surface of the ultrathin toughened glass article under an influence of gravity and surface tension between the bath of molten salt and the ultrathin glass article to form a uniform layer of residual salt on the surface of the ultrathin toughened glass article;
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 and lifting cause the ultrathin toughened glass article to have a surface compressive stress greater than 300 MPa without Optical Orange Skin.