Process for producing mouldings
AssigneeNovartis AG
InventorsBettina Steinmann, Friedrich Stockinger
Life of this patent
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Abstract
A novel process for producing mouldings, especially contact lenses, is described, comprising the following steps: a) introducing into a mould a prepolymer containing photo crosslinkable groups that is liquid at room temperature or is readily meltable and is substantially free of solvents; b) initiating the photo cross-linking for a period of <20 minutes; c) opening the mould, so that the moulding can be removed for the mould. In accordance with the process according to the invention, it is possible especially to produce contact lenses having valuable properties.
Claims20
A process for producing mouldings, comprising the following steps:
- a) introducing into a mould a prepolymer having a weight average molecular weight of from 1000 to 50000 and containing photocrosslinkable groups that is liquid at room temperature or is readily meltable and is substantially free of solvents and comonomers,
- b) initiating the photocrosslinking for a period of <5 minutes,
- c) opening the mould, so that the moulding can be removed from the mould.
A process for producing mouldings, comprising the following steps:
- a) introducing into a mould a prepolymer and containing photocrosslinkable groups that is liquid at room temperature or is readily meltable and is substantially free of solvents, wherein the photocrosslinkable groups are cationically crosslinkable groups selected from the group consisting of epoxy, vinyl ether, propenyl ether, spiroorthoester and spiroorthocarbonate groups and cyclic carbonates,
- b) initiating the photocrosslinking for a period of <20 minutes,
- c) opening the mould, so that the moulding can be removed from the mould.
A process for producing mouldings, comprising the following steps:
- a) introducing into a mould a prepolymer and containing photocrosslinkable groups that is liquid at room temperature or is readily meltable and is substantially free of solvents,
- b) initiating the photocrosslinking for a period of <20 minutes,
- c) opening the mould, so that the moulding can be removed from the mould
- d) swelling the moulding in an aqueous solution selected from the group consisting of a purely aqueous solution and a synthetic lachrymal fluid.
Dependencies are inferred from the claim text.