OPTICAL FIBRE COATINGS CURABLE BY MONOCHROMATIC ACTINIC RADIATION Russian patent published in 2020 - IPC C03C25/105 C03C25/1065 C09D133/10 

FIELD: optics.

SUBSTANCE: described is a method of coating optical fibre, in which coating is cured using a source of monochromatic actinic radiation, such as light-emitting diode. Method of coating optical fibre, comprising the steps of: (a) drawing glass optical fiber through an exhaust column, (b) applying a primary coating composition onto the surface of the glass optical fibre, (c) optionally, subjecting the primary coating composition to a first light emitting diode (LED) capable of emitting UV radiation, for curing said composition of the primary coating, (d) applying a secondary coating composition to the primary coating composition, (e) subjecting the primary coating composition and the secondary coating composition to at least one light emitting diode from the group consisting of a first light emitting diode (LED) and a second light emitting diode (LED) capable of emitting UV radiation, for curing said composition of the primary coating and said secondary coating composition to form a cured primary coating on the surface of the optical fibre and cured secondary coating on surface of hardened primary coating. Secondary coating composition contains: i) from 5 to 20 wt. % monomer of vinyl ether relative to total weight of secondary coating composition, where the vinyl ester monomer is a divinyl ether of triethylene glycol or diethylene glycol divinyl ether, ii) a urethane (meth)acrylate oligomer and iii) one or more free radical photoinitiators. Described is a radiation-curable composition of a secondary coating for optical fibre, comprising a urethane (meth)acrylate oligomer, (meth)acrylate monomer-diluent, a free-radical photoinitiator component and a monomer of vinyl ether, which is multifunctional as a component having an electron-donor substituent bonded to the vinyl group. Described also is coated optical fibre.

EFFECT: technical result is simultaneous achievement of desired properties of high surface hardening, high through hardening and low yellowness.

27 cl, 4 dwg, 3 tbl, 11 ex