Method for improving the edging of an optical article by providing a temporary layer of an organic material

Abstract

The invention relates to a method for edging an optical article comprising the following steps: providing an optical article having two main faces, at least one of which being coated with an outermost layer; fixing the optical article to a chuck by means of a holding pad, the surface of the holding pad to be contacted with the optical article being coated with an adhesive material; and edging the optical article; wherein prior the step of fixing the optical article to the chuck, at least one temporary protective layer of an organic material is formed onto said outermost layer of the optical article, the organic material of the temporary protective layer comprising at least one organic compound having a fluorinated functional moiety, and a linking functional moiety capable of establishing at least one intermolecular bond or interaction with the adhesive material of the holding pad.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to the field of edging optical articles, such as ophthalmic lenses, more particularly those comprising, as an outermost layer, an anti-fouling top coat such as a hydrophobic and / or oleophobic surface coating. [0003] An ophthalmic lens results from a succession of molding and / or surfacing / smoothing operations determining the geometry of both convex and concave optical surfaces of said lens, followed by appropriate surface treatments. [0004] The last finishing step of an ophthalmic lens is the edging operation consisting in machining the edge or the periphery of the glass so as to shape it according to the required dimensions to fit the lens into the eyeglass frame wherein it is to be arranged. [0005] Edging is conventionally performed on a grinding machine comprising diamond abrasive wheels that perform the machining step as defined hereinabove. [0006] The lens is held, upon such an oper...

AI Technical Summary

Benefits of technology

[0025] The present invention has been made in view of the above problems, and it is an object of the present invention to provide a temporary protective coating that would prevent slippage of the lens during edging operations, thus substantially decreasing and even eliminating the offset of the lens, and moreover that would allow to have adhesion of ink markings at the surface of the lens.

[0033] The inventive temporary protective layer allows achieving a sufficient adhesion at the interface holding pad / optical articles for pads conventionally used in the technical field.

Problems solved by technology

As a consequence, the adhesion at the pad / convex surface interface can be thereby altered, making difficult satisfactory edging operations, in particular for polycarbonate lenses, the edging of which generates much more important stresses in comparison with other materials.

High slipperiness of the lens surface may result in substantially shifting the center of the lens from the lens chuck in which the center of the lens is fixed, thus shifting the optical and horizontal / vertical axes of the lens from the real center thereof.

This phenomenon possibly leads to depreciation of vision correcting effects and / or lowering of the visual power of the user wearing the eyeglass, and / or impossibility to insert the lens into the desired frame.

The consequence of a badly performed edging operation is thus the pure and simple loss of the lens.

However, if the anti-fouling top coat is deposited by dip coating, the lenses may be more difficult to edge, particularly if said top coat is OPTOOL DSX from Daikin Industries.

However, the deposition or creation of such layers lengthens the process.

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