Composition for increasing the lipophobicity of a watch-making component
AssigneeRolex SA
InventorsDavid Portet, Gregory Lecollinet
Life of this patent
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Abstract
The present invention describes the highly advantageous properties of a mixture of thiol-perfluoropolyether (PFPE) molecules with perfluorinated bisphosphonic (PF-BP) compounds. This mixture makes it possible in effect to obtain a lipophobic behavior (also referred to as “epilame” effect) with common watch-making lubricants on all the materials tested, including metals, inter alia gold and alloys thereof, ceramics and semiconductors, and gives the surface treated a good resistance to ageing and to cleaning products.
Claims22
A method comprising coating a surface of a watch or jewellery component with a synergistic composition comprising at least one thiol compound and at least one bisphosphonic compound or a salt thereof to form a coated surface,
- wherein said thiol compound is a perfluorinated thiol of the following formula I:
- wherein:
- n is an integer from 6 to 10, m is 5 and x is 1;
- wherein said bisphosphonic compound is a perfluorinated bisphosphonic of the following formula II:
- wherein:
- n is an integer from 4 to 8, m is an integer from 4 to 5 and x is 1;
- and
- wherein the lipophobicity of the coated surface is increased.
A method for coating a surface of a watch or jewellery component, comprising at least the following steps:
- a) optionally degreasing the surface by washing with a solvent and then drying,
- b) optionally oxidising the surface so as to create hydroxyl groups at the surface of the substrate,
- c) contacting the surface with a synergistic composition comprising at least one thiol compound and at least one bisphosphonic compound or a salt thereof, up to the point of self-assembly of thiol and/or bisphosphonic compounds in a single layer coating said surface to form a coated surface and a supernatant,
- d) removing the supernatant,
- e) optionally dehydrating the coated surface,
- f) rinsing the coated surface,
- g) drying the coated surface,
- wherein said thiol compound is a perfluorinated thiol of the following formula I:
- wherein n is an integer from 6 to 10, m is 5 and x is 1;
- and
- wherein said bisphosphonic compound is a perfluorinated bisphosphonic of the following formula II:
- wherein n is an integer from 4 to 8, m is an integer from 4 to 5 and x is 1.
Dependencies are inferred from the claim text.