Le Verre Fluore Sa

France Telecom Etablissement Autonome De Droit Public

Etablissement Public Dit: Agence Nationale De Valorisation De La

Etablissement Public Dit: Centre National De La Recherche Scientifique

Marcel Poulain

Jacques Lucas

Michel Poulain

Gwenael Maze

Jean-Yves Carree

Abdelouhed Soufiane

Jean-Yves Carre

Marc Matecki

Mohammed Saad

Younes Messaddeq

Gwendael Maze

Fluorinated glasses

The present invention relates to a process for the synthesis of fluoride glass by the sol-gel method. The object of the invention is to synthesize an impurity-free fluoride glass. This object is achieved with the aid of a process having stages consisting of preparing a wet oxygenated gel from precursors containing all the cations constituting said fluoride glass, hydrolyzing said gel, drying said gel and in which the process is characterized in that it also comprises the stage consisting of treating said oxygenated gel by a fluorinating agent in the vapour phase, at a temperature below the glass crystallization point. This process more particularly makes it possible to produce fluoride glass for optical fibres.

Process for the synthesis of fluoride glass by the sol - gel method and

The invention gives a coating with a very high vitrification rate. The resulting surface has physicochemical characteristics which are similar to those of fluoride glass. In order to achieve this result, the material constituting the fluoride glass enamel quickly crosses the temperature range between the melting point and the glossy transition temperature. Moreover, the metallic substrate temperature must be high enough to enable an active physiochemical process at the glass-metal interface which results in a correct 'hooking'. A 'hooking' temperature is higher than one where a physical adhesion occurs, which results from Van der Waals interactions without any formation of chemical bonds at the glass-metal interface. The particular chemical reactivity of molten fluorides, which otherwise results in critical problems of corrosion, is in this case a favorable factor which generally reduces the hooking temperature to a level which is far below the glass melting temperature.

Composite materials associating an amorphous barium fluoride coating

Halogenated glass comprising 20 to 90 mole percent of at least one of cadmium, manganese and zinc halide and a process for the preparation thereof.

Halogenated glasses

Compositions of fluorinated glasses are disclosed which result from the ternary composition of ZrF.sub.4 or HfF.sub.4, BaF.sub.2 and ThF.sub.4 or UF.sub.4, each component being within a specified range of composition indices, the indices for the separate components totalling unity.

Compositions of fluoride glasses and process for manufacturing fluoride

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Rennes, France

Marcel Poulain