Abstract: A method for preparing a colloidal solution of non-aggregated zirconia particles, comprising the following steps: a) providing a zirconium hydroxide sol, b) adding to said sol an inorganic acid according to an [inorganic acid]/[Zr] molar ratio of <0.5, c) performing the hydrothermal treatment of said sol, and d) recovering the colloidal solution of zirconia particles.

Abstract: The invention relates to a polymerisable liquid mixture comprising: (a) a polymerisable thermosetting composition which is a precursor by polymerization of a first thermoset polymer material, said composition containing at least one polythiol and/or one polyol, preferably a polythiol, and at least one polyiso(thio)cyanate; and (b) a second polymer material solubilized in the aforementioned polymerisable thermosetting composition, whereby the second material (i) contains at least one block copolymer comprising at least two polymer blocks A and B, namely an elastomer block A and a hydrophilic block B, and, following polymerization of the polymerisable mixture, (ii) forms domains which are rich in elastomer block A and which are dispersed throughout the first material, said domains being smaller than 80 nanometers and preferably smaller than 50 nanometers.

Abstract: A method for producing an article which is made of a transparent material and devoid of visible surfacing lines, comprising: obtaining a substrate which is made of a transparent material having a refractive index ns, at least one main face of which has been ground and polished in such a way that the Ra value thereof ranges from 0.001 to 0.1 ?m, but has visible surface defects in the form of thin individual scratches; depositing, a liquid polymerisable composition of a masking coating, the contact angle of which with said substrate main face being equal to or less than 30° and which forms upon polymerization a masking coating having a refractive index nc such that 0.01<|ns?nc|?0.15 and a thickness less than 10 micrometers, directly onto the ground and polished main face of the substrate, polymerizing the masking coating composition; and recovering the transparent article.

Abstract: The invention relates to polarized and abrasion-resistant article comprising: a) a polarized layer applied to a substrate, said polarized layer including an oriented liquid crystal polymer layer (LCP) including at least one dichroic dye, said liquid crystal layer being coated on a photo-orientation layer, and b) an abrasion-resistant coating applied to the polarized layer on said substrate. The invention also relates to a process for manufacturing said articles, and to the use of the above-mentioned article for the manufacturing of optic glasses or lenses.

Abstract: The object of the invention is a process for molding an optical element such as a lens (2). According to the invention, the element is obtained by a reaction injection molding process comprising the steps of mixing at least two polymerizing reactants and forcing the obtained reacting mixture by an injection duct (5) for filling under pressure a scaled mold cavity (4) having an entry side (43) provided with a casting opening (42) and an evacuation side (44) and providing a laminated flow of mixture in a spout (6) having a progressive enlarging transversal section between the outlet opening (52) of the injection duct (5) and the casting opening (42) of the mold cavity (4), for avoiding any turbulent area in said laminated flow, said evacuation side (44) being provided with means (45) for evacuating air contained in the mixture during mold filling. The invention also covers the molding installation adapted for using such a process.

Abstract: The present invention relates to an optical article, in particular an ophthalmic lens comprising a substrate, a coating that includes at least one photodegradation-sensitive dye, and a photodegradation protection (anti-UV) coating for protecting the coating containing at least one photodegradation-sensitive dye, the photo-degradation protection coating comprising a blend of acrylate oligomers and monofunctional or multifunctional acrylate monomers, at least one UV absorber and at least one photoinitiator. This anti-UV coating used is particularly suitable for an ophthalmic lens in which the polarizing function is provided by a bilayer system, one layer of which comprises liquid crystals combined with dyes, and more particularly dichroic dyes. Advantageously, the anti-UV coating according to the invention is combined with an oxygen barrier layer.

Abstract: The installation includes elements for the temporary injection of inert gas; and at least one individual and autonomous casing (6) provided with a window (13) and including receiving elements for a support (3) carrying an ophthalmic lens (2), and sealing elements (21) adapted to form around the ophthalmic lens (2) a sealed enclosure, that enclosure including a non-return inlet member adapted to cooperate with the elements for the temporary injection of inert gas.

Abstract: A method for preparing a colloidal solution of non-aggregated zirconia particles, comprising the following steps: a) providing a zirconium hydroxide sol, b) adding to said sol an inorganic acid according to an [inorganic acid]/[Zr] molar ratio of <0.5, c) performing the hydrothermal treatment of said sol, and d) recovering the colloidal solution of zirconia particles.

Abstract: A method for producing an article which is made of a transparent material and devoid of visible surface lines consists in producing a substrate which is made of a transparent material having a refractive index ns, whose at least main face is machined and polished in such a way that the Ra value thereof ranges from 0.001 to 0.1 ?m, but has visible surface defects in the form of thin individual scratches, in deposing, a liquid polymerisable composition of a masking coating, whose contact angle with said substrate main face is equal or less than 30° and which is formed by polymerising a masking coating having a refractive index nc such as 0.01<|ns?nc|=0.15 and a thickness less than 10 micrometers, directly on the machined and polished main face of the substrate, in polymerising the masking coating composition and in removing the transparent article.

Abstract: A polarizing optical element is produced by firstly forming a polarizing multilayer structure (30) on a support (31). The structure comprises an orienting layer and a polarizing layer having dichroic compounds, the dichroic compounds being oriented by the orienting layer. The multilayer structure is then pressed against one surface of the optical element (40) through the support, with a portion of adhesive placed between the structure and the optical element. The support (31) for the structure is then removed, leaving the structure (30) bonded to the optical element (40).

Abstract: A multilayer polarizing structure is produced on a temporary support. The structure comprises at least one orienting layer and one polarizing layer comprising dichroic dyes, the dichroic dyes having an angular orientation determined by the orienting layer. The multilayer structure is separated from the temporary substrate before being applied onto a surface of an optical element. Applying the structure onto the optical element may be easily carried out while obtaining a quality compatible with many uses of the optical element, in particular ophthalmic uses.

Abstract: Curable composition comprising: (a) one or more particular polyisocyanates or a polyurethane prepolymer obtained by the polycondensation of a polyisocyanate in excess, chosen from said polyisocyanates, with one or more polyols comprising at least two free alcohol functional groups, chosen from polypropoxylated or polyethoxylated bisphenol A compounds and polyfunctional polycaprolactone-alcohols; (b) one or more polyols comprising at least two free alcohol functional groups, chosen from polypropoxylated or polyethoxylated bisphenol A compounds and polyfunctional polycaprolactone-alcohols, and polyurethane prepolymers obtained by the polycondensation of one or more polyols in excess, chosen from the above polyols, with one or more particular polyisocyanates, the ratio of the number of isocyanate functional groups of the polyisocyanate component (a) to the number of alcohol functional groups of the polyol component (b) being between 1.00 and 1.

Abstract: The invention relates to polyurethane resins for producing impact-resistant optical lenses, in particular ophthalmic lenses made by using said resins and to a method for producing said lenses, in particular for using thermosetting polyurethane resin for producing the optical lenses, wherein said resin comprises a part (I) corresponding to an isocyanate part containing. A) a methylene-bis-4,4?-isocyanatecyclohexane (Hi2MDI), b) a prepolymer obtainable by the reaction between propoxilated glycerol and a methylene-bis-4,4?-diisocyanatecyclohexane and a part (II) corresponding to an alcohol part containing: c) an alkoxylated etherate glycerol in the monomer and oligomer form thereof and d) at least one type of a polyalkoxylated tertiary diamine tetraol and/or triol.

Abstract: The invention relates to a polymerisable liquid mixture comprising: (a) a polymerisable thermosetting composition which is a precursor by polymerisation of a first thermoset polymer material, said composition containing at least one polythiol and/or one polyol, preferably a polythiol, and at least one polyiso(thio)cyanate; and (b) a second polymer material solubilised in the aforementioned polymerisable thermosetting composition, whereby the second material (i) contains at least one block copolymer comprising at least two polymer blocks A and B, namely an elastomer block A and a hydrophilic block B, and, following polymerisation of the polymerisable mixture, (ii) forms domains which are rich in elastomer block A and which are dispersed throughout the first material, said domains being smaller than 80 nanometers and preferably smaller than 50 nanometers.

Abstract: The present invention relates to a method for the preparation of a transparent moulding comprising a blend of a thermoset polymeric material forming the matrix of said article, and a thermoplastic polymeric material, dispersed within said thermoset polymeric material, said process comprising at least the following stages: i) preparation of a liquid polymerizable mixture by dissolving said thermoplastic polymeric material in a thermosetting composition that is a precursor of said matrix, ii) filling of a mould with the liquid polymerizable mixture prepared in stage i), iii) polymerization of the liquid polymerizable mixture until a hardened blend of polymers is obtained, and iv) removal of the moulding formed by said blend of polymers, said process being characterized by the fact that the thermosetting composition comprises at least 60% by weight of 4,4?-di(ethoxyethyl)-bisphenol A dimethacrylate and at least 12% by weight of at least one monofunctional or multifunctional acrylic comonomer and by the fact

Abstract: A mold for molding an optical element, in particular using a reaction injection molding method (RIM). The mold comprises a generally circular shaped, mold cavity having a geometrical center and a main plane, a sprue base with a longitudinal axis and a feed connection that makes the sprue base communicate with a feed sill of the mold cavity, the longitudinal axis of the sprue base and the geometrical center of the mold cavity defining a mold symmetry plane orthogonal to the main plane of the mold cavity, which intersection with said main plane defines a mold main axis, characterized in that the longitudinal axis of the sprue base together with a line perpendicular to the main plane of the mold cavity forms an angle ranging from 0 to 30°, preferably from 0 to 15°. Methods of using the mold and objects made thereby are also disclosed.

Abstract: The present invention relates to a method of preparing a transparent moulding comprising a blend of a first thermoset polymeric material forming the matrix of said moulding, and of a second polymeric material dispersed within said first material, said method comprising at least the following stages: i) preparation of a liquid polymerizable mixture by dissolving said second polymeric material in a thermosetting polymerizable composition that is a precursor of said first thermoset polymeric material, ii) filling of a mould with the liquid polymerizable mixture obtained in stage i), iii) cooling of the liquid polymerizable mixture in the mould to a temperature T less than or equal to 0° C., iv) initiation of the polymerization of said cooled liquid polymerizable mixture at a temperature T? less than or equal to 0° C.

Abstract: The object of the invention is a process for molding an optical element such as a lens (2). According to the invention, the element is obtained by a reaction injection molding process comprising the steps of mixing at least two polymerizing reactants and forcing the obtained reacting mixture by an injection duct (5) for filling under pressure a scaled mold cavity (4) having an entry side (43) provided with a casting opening (42) and an evacuation side (44) and providing a laminated flow of mixture in a spout (6) having a progressive enlarging transversal section between the outlet opening (52) of the injection duct (5) and the casting opening (42) of the mold cavity (4), for avoiding any turbulent area in said laminated flow, said evacuation side (44) being provided with means (45) for evacuating air contained in the mixture during mold filling. The invention also covers the molding installation adapted for using such a process.

Abstract: A two-part polyisocyanate/polyol composition, curable upon mixing of the two parts for molding casted products, which comprises: —a first polyisocyanate part A, liquid at mixing temperature, comprising at least one polyisocyanate compound A1 bearing at least three (3) isocyanate groups and having at least one isocyanurate cycle in its molecule and at least one diisocyanate compound A2; and—a second polyol part B comprising at least one diol compound B1.

Abstract: A polarising optical element is produced by firstly forming a polarizing multilayer structure (30) on a support (31). The structure comprises an orienting layer and a polarizing layer having dichroic compounds, the dichroic compounds being oriented by the orienting layer The multilayer structure is then pressed against one surface of the optical element (40) through the support, with a portion of adhesive placed between the structure and the optical element. The support (31) for the structure is then removed, leaving the structure (30) bonded to the optical element (40).