摘要:
There is described a composition for forming an contact lens, in particular for forming a silicone hydrogel contact lens, comprising at least one first vinylic monomer or macromer having one first ethylenically unsaturated group and at least one second vinylic monomer or macromer having one second ethylenically unsaturated group, wherein the first and second ethylenically unsaturated groups are different from each other and wherein the composition further comprises a crosslinker with at least two ethylenically unsaturated (polymerizable) groups with a selected kinetic copolymerization parameter r1 of less than 1.0 relative to one of the first and second ethylenically unsaturated (polymerizable) groups as defined above.
摘要:
An apparatus and method for the production of ophthalmic lenses, and particularly contact lenses, which minimizes damage of the lens in removal from the mold. The ophthalmic lens is produced in a mold having a male part and a female part that are placed in proximate relation to each other to create a lens-forming cavity. At least the female surface of the female part mold is preferably coated with plasma and is irradiated for a predetermined time such that the female surface and/or surface coating is at least partially cured. Once the female surface, and alternately the male surface and other surfaces of the mold, is at least partially cured, a curable lens-forming material is placed into the lens-forming cavity and cured to form an ophthalmic lens.
摘要:
In a process for removing bubbles from viscous polymer solutions (P) in which the content of dissolved gases lies below the saturation limit, the viscous polymer solution (P) is subjected to a superatmospheric pressure. The superatmospheric pressure is such that the gases contained in the bubbles of the polymer solution (P) dissolve.
摘要:
The invention relates to a process for the manufacture of a molding comprising the steps of a) preparing an aqueous solution comprising a water-soluble prepolymer having crosslinkable groups and a further polymer which is devoid of crosslinkable groups, b) introducing the solution obtained into a mold, c) triggering the crosslinking, and d) opening the mold such that the molding can be removed from the mold. According to the process of the invention moldings such as contact lenses may be manufactured with an improved quality and an improved overall yield.
摘要:
A method of incorporating radiation-absorbing agents (i.e., dyes) into polymeric materials. A preferred method involves crosslinking or polymerizing a polymerizable or crosslinkable material in the presence of a polymeric dye. A preferred product is a tinted contact lens comprising poly(vinyl alcohol). The methods offer advantages in reduced fabrication cycles, reduced extractables, elimination of post-polymerization activation steps, elimination of post-polymerization extraction steps and reduced scrap and costs associated with lens handling.
摘要:
The present invention describes novel statistical copolymers and the preparation and possible uses thereof. Copolymers are described that are water-soluble and cross-linkable and that comprise the copolymerisation product of a monomer mixture consisting substantially of a vinyl lactam (a) and at least one further vinyl monomer (b) of a different type selected from the group consisting of hydrophobic, hydrophilic and functional vinyl monomers, wherein the monomers are present in the copolymer in the form of statistically distributed building blocks, and, if a functional vinyl monomer is present as a building block in the copolymer, that building block is, where appropriate, modified with a reactive vinyl monomer (c), the reactive vinyl monomer (c) being linked to a building block of a functional vinyl monomer with retention of its vinylic group and with the formation of a covalent bond.
摘要:
The blister pack comprises a base portion and a cover layer. The base portion comprises a hollow chamber that contains a soft hydrophilic contact lens and a sterile aqueous preserving solution, and a substantially flat flange that extends right round the outside of the hollow chamber. The cover layer is releasably sealed to the flange in a sealing zone that extends right round the circumference of the hollow chamber. The flange comprises a grip region that extends from one side of the hollow chamber beyond the sealing zone and is covered by a corresponding grip region of the cover layer but is not sealed thereto. The hollow chamber comprises a dish-shaped main chamber and, adjoining the side of that main chamber, a secondary chamber in the shape of a channel tapering on all sides away from the main chamber, the main chamber making a smooth transition into the secondary chamber, and the main chamber and the secondary chamber together having a drop-shaped contour in the plane of the flange, the tip of which contour is directed towards the grip region of the flange. Provided in the grip region of the flange is an oval opening by means of which the overlying grip region of the cover layer can be lifted from the flange. A support element that is angled with respect to the plane of the flange is arranged in the grip region of the flange. An angled grip element or facilitating the handling of the blister pack is arranged at the edge of the flange on both sides of the hollow chamber. The base portion is so shaped that the blister packs can be nested in pairs with their undersides one inside the other, in each case the hollow chamber of one blister pack lying in the region of the grip region of the other blister pack. The blister pack is extremely handy, space-saving and stable, requires only an extremely small amount of preserving solution and enables the contact lens it contains to be removed especially easily.
摘要:
The instant invention pertains to a method and a fluid composition for producing contact lenses with improved lens quality and with increased product yield. The method of the invention involves adding a phospholipid into a fluid composition including a lens-forming material in an amount sufficient to reduce an averaged mold separation force by at least about 40% in comparison with that without the phospholipids.
摘要:
There is described a method of separating excess lens forming material from a molded ophthalmic lens, in particular a contact lens. After polymerization and/or cross-linking of a lens forming material (P) within a mold cavity (4) of a mold (1) comprising female and male mold halves (2, 3) to form an ophthalmic lens non-polymerized and/or non-cross-linked lens forming material is flushed away from the mold halves (2, 3) with a jet of a fluid flushing medium, such as, e.g., water or a solvent or an inert gas. Subsequently the molded lens is dried. In accordance with the invention the flushing is accomplished with the mold halves (2, 3) still in the closed position. There is also described an apparatus for carrying out the method.
摘要:
The invention provide a class of actinically-crosslinkable silicone-containing prepolymers which comprise dangling polysiloxane chains each having a terminal ethylenically-unsaturated group and are obtained in a one-step of RAFT polymerization of a reactive mixture comprising a polysiloxane crosslinker, a hydrophilic vinylic monomer, a RAFT agent, and a free-radical initiator. The present invention is also related to silicone hydrogel contact lenses made from a prepolymer of the invention and methods for making the contact lenses in a cost-effective way and with high consistency and high fidelity to the original lens design.