Patent ID: 11927919
Assignee: PATEK PHILIPPE SA GENEVE
Field: Basic materials chemistry (Chemistry)
Classification: CPC G  B  C | IPC C  G

Claim 0:
1. A timepiece assembly comprising at least two elements in contact and mobile relative to each other, one of said elements having at least a first contact surface intended to rub against at least a second contact surface of the other element under dry lubrication conditions, wherein at least one of said first and second contact surfaces is covered with a hydrophobic coating having an angle of contact with water greater than 90°, and a coefficient of friction lower than 0.15, the variation in said coefficient of friction as a function of the relative humidity being lower than 25%,
wherein the hydrophobic coating is bonded to one of said first and second contact surfaces at least by covalent bonds,
wherein said one of the first and second contact surfaces comprises active —OH sites at a density greater than 1014 OH sites/cm2, the second contact surface having subjected, prior to the deposition of the hydrophobic coating, to a surface hydroxylation treatment.