Process for photoinitiated control of inorganic network formation in the sol-gel process

US5360834A · kind A · utility

Assignee

• Max-Planck-Gesellschaft zur Föderung der Wissenschaften e.V. · US

Inventors

• Michael Popall · Coburg, DE
• Jochen Schulz · Veitshöchheim, DE
• Helmut Schmidt · Riegelsberg, DE

Key dates

• Filing date: Jan 31, 1994
• Grant date: Nov 1, 1994
• Expiry date: Jan 31, 2014

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C03C17/25
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A process is described for photoinitiated control of inorganic network fotion in the sol-gel process, which comprises either PA0 A) subjecting one or more hydrolytically polycondensable compounds of constituent elements of glass or ceramic, excluding silicon compounds containing polymerizable organic groups, to hydrolytic polycondensation in a liquid reaction medium to form a sol and PA0 irradiating the resulting sol in a structured or unstructured manner in the presence of a photoinitiator which can change the pH of the reaction medium on irradiation, using radiation of a wavelength range in which the photoinitiator absorbs; or PA0 B) liberating water in an anhydrous reaction medium which contains an alcohol, one or more hydrolytically polycondensable compounds of constituent elements of glass or ceramic and a photoinitiator which can liberate water by a photochemical reaction or a secondary reaction when irradiated, by structured or non-structured irradiation using radiation of a wavelength range in which the photoinitiator absorbs, and in this way effecting the hydrolytic polycondensation.