Document Type and Number:
Japanese Patent JPS5324112
Kind Code:
B2
Abstract:
1449685 Grafted silicone polymer E W MERRILL 3 Dec 1973 [4 Dec 1972] 55857/73 Addition to 1378971 Heading C3G [Also in Division G2] A contact lens or lens element formed of an organic silicone polymer having a surface comprising a hydrophilic polymer grafted thereon is prepared by contacting a surface of the silicone uniformly with a liquid containing a free-radical polymerizable precursor to said hydrophilic polymer and exposing said surface while in contact with said precursor to ionizing radiation sufficient to cause said precursor to graft to said surface, while controlling the intensity and duration of radiation and the concentration of precursor to prevent excessive migration of precursor into the silicone and to prevent non-uniform and excessive polymerization of the precursor. Examples are given in which (a) contact lens cores formed from cross-linked polydimethyl co-vinyl-methyl siloxane polymer are immersed in N-vinyl pyrrolidone or a 2-hydroxyethyl methacrylate/ glycerol mixture and subjected to radiation from a Van de Graaff generator; (b) a lens moulded from carbonate-siloxane-carbonate block copolymer is immersed in aqueous N-vinyl pyrrolidone and irradiated; (c) a membrane of block copolymer as in (b) is applied to both sides of a lens-shaped pellet of polymer as in (a) and exposed to radiation; (d) a lens formed from polymer as in (a) is immersed in a N-vinyl pyrrolidone/2-hydroxyethyl methacrylate mixture and irradiated, or immersed in N-vinyl pyrrolidone and irradiated, followed by immersion in 2-hydroxyethyl methacrylate and further irradiation, or immersed in N-vinyl pyrrolidone, or aqueous N-vinyl pyrrolidone, and subjected to irradiation in several stages; (e) a disc of polymer as in (a) is floated on a solution of N-vinyl pyrrolidone and polyvinyl pyrrolidone and subjected to irradiation in several stages; (f) a lens as in (d) is immersed in aqueous N- vinyl pyrrolidone and irradiated, or in aqueous 2-hydroxyethyl methacrylate, containing only a trace of ethylene glycol dimethacrylate and irradiated; (g) a lens as in (d) is placed in aqueous solutions containing N-vinyl pyrrolidone and 2-hydroxyethyl methacrylate and irradiated; and (h) a membrane as in (c) is contacted with aqueous solutions containing N-vinyl pyrrolidone and/or 2-hydroxyethyl methacrylate and irradiated and the resulting membranes are placed on both sides of a contact lens moulded from uncross-linked polymer as in (a), the assembly being enclosed in the original mould with the grafted surfaces of the films facing toward the mould, compressed and exposed to radiation.
Application Number:
JP13722273A
Publication Date:
July 19, 1978
Filing Date:
December 04, 1973
Export Citation:
International Classes:
G02C7/04; B29D11/00; C08F283/00; C08F283/12; C08J7/18