Abstract:
The invention relates to a method using visible and/or near-ultraviolet light for the photopolymerisation of a composition free from mineral particles, comprising at least one photopolymerisable monomer and at least one photoinitiator which is selected from suberone derivatives and mixtures of an alpha -diketone and an organic peroxide. The invention is suitable for use in the production of ophthalmic lenses.
Abstract:
A lens has at least one insert ( 16, 28 ), which defines an optical path. For manufacturing the lens, the insert is first bonded to an overmould ( 36 ). A polymer ( 44 ) is then moulded in a mould ( 42, 36 ) formed on one of its faces from the overmould. After moulding, the overmould may be preserved and form part of the lens, if necessary after surface grinding. The overmould may also be separated from the lens; in this case, the lens is machined, removing at least part of the inserts. The lens obtained has an insert in a reproducible position, with an entrance or exit surface inducing no optical distortion.
Abstract:
A lens has at least one insert ( 16, 28 ), which defines an optical path. For manufacturing the lens, the insert is first bonded to an overmould ( 36 ). A polymer ( 44 ) is then moulded in a mould ( 42, 36 ) formed on one of its faces from the overmould. After moulding, the overmould may be preserved and form part of the lens, if necessary after surface grinding. The overmould may also be separated from the lens; in this case, the lens is machined, removing at least part of the inserts. The lens obtained has an insert in a reproducible position, with an entrance or exit surface inducing no optical distortion.
Abstract:
The compositions comprise:(a) at least 40 parts by weight, preferably at least 50 parts by weight, of at least one thio(meth)acrylate monomer,(b) at least one high Abbe number monomer,(c) at the most 20 parts by weight, preferably at the most 15 parts by weight and more preferably 10 parts by weight of an aromatic polyvinyl monomer, and(d) at least one polythiol, for 100 parts by weight of (a), (b), (c) and (d).Application for the manufacture of optical lenses.
Abstract:
The compositions comprise:(a) at least 40 parts by weight, preferably at least 50 parts by weight, of at least one thio(meth)acrylate monomer,(b) at least one high Abbe number monomer,(c) at the most 20 parts by weight, preferably at the most 15 parts by weight and more preferably 10 parts by weight of an aromatic polyvinyl monomer, and(d) at least one polythiol, for 100 parts by weight of (a), (b), (c) and (d).Application for the manufacture of optical lenses.
Abstract:
Polymerizable compositions for making transparent polymeric substrates, resulting transparent polymeric substrates and the applications thereof in optics. The composition comprises: from 35 to 70 parts by weight of one or more monomers (I) of formula: wherein R 1 and R 2 represent H or CH 3 , A is a divalent moiety of formula: m1 and m2 each are an integer in the range of 4 to 20, from 5 to 50 parts by weight of a monomer (II) comprising at least a urethane unit and at least two (meth)acrylate functions, and from 5 to 40 parts by weight of a monomer (III) with a high Abbe number and comprising one or more methacrylate functions, the total of the monomers (I), (II) and (III) representing 100 parts by weight.
Abstract:
Polymerizable compositions for making transparent polymeric substrates, resulting transparent polymeric substrates and the applications thereof in optics. The composition comprises: from 35 to 70 parts by weight of one or more monomers (I) of formula: wherein R 1 and R 2 represent H or CH 3 , A is a divalent moiety of formula: m1 and m2 each are an integer in the range of 4 to 20, from 5 to 50 parts by weight of a monomer (II) comprising at least a urethane unit and at least two (meth)acrylate functions, and from 5 to 40 parts by weight of a monomer (III) with a high Abbe number and comprising one or more methacrylate functions, the total of the monomers (I), (II) and (III) representing 100 parts by weight.