Abstract:
A method and coating used to prepare a photo chromically-enabled bifocal.ophthalmic lens. The method and equipment includes injection molding a single vision lens (10e), for example, from polycarbonate. The clamp opens vertically and the top insert (20) is exchanged for a bifocal mold (30) having a base curve similar to the single vision lens. The thermos et coating includes compounds from several acrylate classes, and is applied to the single vision lens. The coating may include a photochromic dye. The coating is also formulated to receive a photochromic solution through an imbibition process.
Abstract:
A method and coating used to prepare a photo chromically-enabled bifocal.ophthalmic lens. The method and equipment includes injection molding a single vision lens (10e), for example, from polycarbonate. The clamp opens vertically and the top insert (20) is exchanged for a bifocal mold (30) having a base curve similar to the single vision lens. The thermos et coating includes compounds from several acrylate classes, and is applied to the single vision lens. The coating may include a photochromic dye. The coating is also formulated to receive a photochromic solution through an imbibition process.
Abstract:
A transparent, non elastomeric, high index, impact resistant polythiourethane/urea material comprising the reaction product of: a) at least one (α, ω)-diiso(thio)cyanate cycloaliphatic or aromatic prepolymer having a number average molecular weight ranging from 100 to 3000 gmol−1, and b) at least one primary diamine, in an equivalent molar ratio amine function/iso(thio)cyanate function from 0.5 to 2, preferably from 0.90 to 1.10, wherein, said prepolymer and diamine are free from disulfide (—S—S—) linkage and at least one of the prepolymer or the diamine contains one or more S atoms in its chain.
Abstract:
A method of fast curing polythiourethane transparent casted substrate, usable for making optical articles such as ophthalmic lenses, which comprises the steps of: 1) Providing a first componentA comprising a polythiourethane prepolymer having isocyanate or isothiocyanate end groups and a viscosity at 25 ~C ranging from 0.02 to 0.4 Pa.s; 2) Providing a second component B comprising a polythiourethane prepolymer having thiol (SH) end groups and a viscosity at 25 ~C ranging from 0.2 to 2.0 Pa.s; 3) Mixing together first and second components A and B and filling a moulding cavity of a casting mould assembly with the resulting mixture ; 4) Curing said mixture to obtain a transparent solid substrate, said curing step comprising: a) a first step for polymerizing said mixture to obtain a gel within 1 to 10 minutes; and b) a second step of post-curing the gel to obtain the transparent solid substrate; and 5) Recovering the transparent solid substrate from the mould.
Abstract:
A transparent, non elastomeric, high index, impact resistant polythiourethane/urea material comprising the reaction product of: a) at least one (α, ω)-diiso(thio)cyanate cycloaliphatic or aromatic prepolymer having a number average molecular weight ranging from 100 to 3000 gmol−1, and b) at least one primary diamine, in an equivalent molar ratio amine function/iso(thio)cyanate function from 0.5 to 2, preferably from 0.90 to 1.10, wherein, said prepolymer and diamine are free from disulfide (—S—S—) linkage and at least one of the prepolymer or the diamine contains one or more S atoms in its chain.
Abstract:
A method of fast curing polythiourethane transparent casted substrate, usable for making optical articles such as ophthalmic lenses, which comprises the steps of: 1) Providing a first component A comprising a polythiourethane prepolymer having isocyanate or isothiocyanate end groups and a viscosity at 25° C. ranging from 0.02 to 0.4 Pa.s; 2) Providing a second component B comprising a polythiourethane prepolymer having thiol (SH) end groups and a viscosity at 25° C. ranging from 0.2 to 2.0 Pa.s; 3) Mixing together first and second components A and B and filling a moulding cavity of a casting mould assembly with the resulting mixture; 4) Curing said mixture to obtain a transparent solid substrate, said curing step comprising: a) a first step for polymerizing said mixture to obtain a gel within 1 to 10 minutes; and b) a second step of post-curing the gel to obtain the transparent solid substrate; and 5) Recovering the transparent solid substrate from the mould.
Abstract:
A method of fast curing polythiourethane transparent casted substrate, usabl e for making optical articles such as ophthalmic lenses, which comprises the steps of: 1) Providing a first componentA comprising a polythiourethane prepolymer having isocyanate or isothiocyanate end groups and a viscosity at 25 ~C ranging from 0.02 to 0.4 Pa.s; 2) Providing a second component B comprising a polythiourethane prepolymer having thiol (SH) end groups and a viscosity at 25 ~C ranging from 0.2 to 2.0 Pa.s; 3) Mixing together first an d second components A and B and filling a moulding cavity of a casting mould assembly with the resulting mixture ; 4) Curing said mixture to obtain a transparent solid substrate, said curing step comprising: a) a first step fo r polymerizing said mixture to obtain a gel within 1 to 10 minutes; and b) a second step of post-curing the gel to obtain the transparent solid substrate ; and 5) Recovering the transparent solid substrate from the mould.