Optical article comprising a temporary antifog coating based on sorbitan surfactants

摘要

An optical article includes a substrate having a main surface coated with an antireflection coating and, directly contacting the antireflection coating, a precursor coating of an antifog coating obtained through the grafting on the antireflection coating of at least one compound B bearing a polyoxyalkylene group, the coating precursor of the antifog coating being coated with a surfactant film so as to form an antifog coating. The surfactant film contains at least one surfactant A having a sorbitan ring hydroxyl groups functionalized with OH-terminated polyoxyalkylene groups and R1 groups of formula:—(RdO)z—(Y)n2—R′, in which Rd is an alkylene group, z is an integer >1, Y is a divalent group, n2 is 0 or 1 and R′ is a saturated hydrocarbon group having 12 to 19, preferably 13 to 19 carbon atoms. Surfactants A provide a visual indication whether or not the antifogging effect will still be long-lasting.

主权项

1. An optical article comprising a substrate having at least one main surface coated with an antireflection coating and, directly contacting said antireflection coating, a precursor coating of an antifog coating obtained through the grafting on said antireflection coating of at least one compound B bearing a polyoxyalkylene group, said coating precursor of the antifog coating being coated with a surfactant film so as to form an antifog coating, characterized in that said surfactant film contains at least one surfactant A having a sorbitan ring with n of its four hydroxyl groups functionalized with the same or different OH-terminated polyoxyalkylene groups, and p of its four hydroxyl groups functionalized with the same or different R1 groups of formula:
—(RdO)z—(Y)n2—R′ in which Rd is an alkylene group, z is an integer≧1, Y is a divalent group, n2 is 0 or 1 and R′ is a saturated hydrocarbon group having from 12 to 19 carbon atoms, n and p being integers such that n=2 or 3 and p=1 or 2 with n+p=4.