摘要:
Described is a method of preparing a cured, non-elastomeric polymeric sheet derived from a polyisocyanate. The method comprises the following steps: combining a first component and second, separate component to form a reaction mixture; introducing the reaction mixture into a preheated sheet mold at a certain minimum fill rate, allowing the reaction mixture to gel; heating the reaction mixture to a temperature and for a time sufficient to yield a cured sheet having a thickness of at least 6.35 mm (0.25 in); and removing the cured sheet from the mold to yield a non-elastomeric polymeric sheet. When the active hydrogen functional groups in the second component include hydroxyl groups, the first and second components are initially heated to a temperature of at least 50° C., Polyurethane sheets formed by such processes demonstrate minimal optical defects and the process allows for the production of superior sheets of higher thicknesses than previously possible.
摘要:
A polarized optical element comprising: an optical part made of polyurethane-based optical material; and a polarizing film integrally bonded to the optical part, wherein the polyurethane-based optical material comprises the reaction product of a liquid-phase material comprising: a) a liquid polyisocyanate or polyisocyanate prepolymer having a content of —NCO functional groups comprised between 5 and 50% by weight and an average functionality of 2 to 3, b) an isocyanate-reactive component comprising at least one organic compound containing at least two aromatic amine groups, and c) at least one organometallic catalyst.
摘要:
A method is described for manufacturing an optical element (13) made of thermosetting plastic material comprising the steps of: a) positioning in a mould a first self-supporting layer (6) made of partially cross-linked thermosetting plastic material including reactive functional groups; b) forming, on at least one surface of the self-supporting layer (6), a second layer (12) including: i) a polymerisable material in liquid phase including: prepolymers and/or monomers including reactive functional groups capable of chemically reacting with the reactive functional groups of the self-supporting layer made of partially cross-linked thermosetting plastic material, a reactive component including functional groups capable of chemically reacting with the reactive functional groups of the prepolymers and/or of the monomers and optionally with the reactive functional groups of the self-supporting layer (6) made of partially cross-linked thermosetting plastic material; ii) at least one element adapted to modify the spectral characteristics of the transmitted light; and c) cross-linking said first (6) and second (12) layers in the mould, so as to form a solid monolithic optical element (13) made of thermosetting plastic material comprising at least one functionalised layer (12) adapted to modify the spectral characteristics of the transmitted light. The optical element (13) thus obtained may have polarising properties, has optimal optical and mechanical characteristics and is capable at the same time of modifying the spectral characteristics of the transmitted light as desired.
摘要:
A method of manufacturing a polarized optical element comprises the steps of: providing a polarizing film comprising free hydroxyl groups; placing the polarizing film within a mold cavity: admitting into the mold cavity a liquid-phase polyurethane-based optical material containing —NCO functional groups reactive with said hydroxyl groups and comprising the following components: A) a liquid polyisocyanate or polyisocyanate prepolymer having a content of —NCO functional groups comprised between 5 and 50% by weight and an average functionality of 2 to 3, B) an isocyanate-reactive component comprising at least one organic compound containing at least two aromatic amine groups, and C) at least one organometallic catalyst; curing the liquid-phase polyurethane-based optical material to form a polarized optical element. The method allows to reliably manufacture a polarized optical element comprising an optical part made of polyurethane-based optical material and a polarizing film integrally bonded to the optical part even using thin freestanding polarizing films, such as PVA films, achieving at the same time improved adhesion properties of the polarizing film to the optical material.
摘要:
A polarized optical element comprising: an optical part made of polyurethane-based optical material; and a polarizing film integrally bonded to the optical part, wherein the polyurethane-based optical material comprises the reaction product of a liquid-phase material comprising: a) a liquid polyisocyanate or polyisocyanate prepolymer having a content of —NCO functional groups comprised between 5 and 50% by weight and an average functionality of 2 to 3, b) an isocyanate-reactive component comprising at least one organic compound containing at least two aromatic amine groups, and c) at least one organometallic catalyst.
摘要:
A method of manufacturing a polarized optical element comprises the steps of: providing a polarizing film comprising free hydroxyl groups; placing the polarizing film within a mold cavity: admitting into the mold cavity a liquid-phase polyurethane-based optical material containing —NCO functional groups reactive with said hydroxyl groups and comprising the following components: A) a liquid polyisocyanate or polyisocyanate prepolymer having a content of —NCO functional groups comprised between 5 and 50% by weight and an average functionality of 2 to 3, B) an isocyanate-reactive component comprising at least one organic compound containing at least two aromatic amine groups, and C) at least one organometallic catalyst; curing the liquid-phase polyurethane-based optical material to form a polarized optical element. The method allows to reliably manufacture a polarized optical element comprising an optical part made of polyurethane-based optical material and a polarizing film integrally bonded to the optical part even using thin freestanding polarizing films, such as PVA films, achieving at the same time improved adhesion properties of the polarizing film to the optical material.
摘要:
A plano-convex optical sheet having a positive power including: a substantially planar inner surface; opposed lateral edges, and a thickness s that is decreasing proceeding from a transversal central line passing through the geometric center of the optical sheet towards said opposed lateral edges along a portion of predetermined width w of the optical sheet, so as to define a convex outer surface having a curvature such that the optical sheet is capable of providing once bent a cylindrically shaped optically correct visor.