Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D11/00—Producing optical elements, e.g. lenses or prisms
  • B29D11/00009—Production of simple or compound lenses
  • B29D11/00317—Production of lenses with markings or patterns
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
  • G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
  • G02B1/041—Lenses
  • G02B1/043—Contact lenses

Definitions

• the present invention relates generally to a method of coloring contact lenses, and more particularly hydrophilic, flexible contact lenses.
• Document GB-A-1 004424 describes a method of coloring flexible contact lenses which consists in dipping a contact lens, flexible, uncolored in a concentrated solution of a dye for a time sufficient to allow the dye to penetrate into the lens. In this method, it is possible to mask parts of the contact lens so as to color only selected areas of the lens.
• the recommended dyes are certain acid dyes for dyeing wool, such as the conventional "azo" and "vat" dyes.
• Document EP-A-082 026 describes a method for coloring rigid, non-hydrophilic contact lenses which consists in immersing such a contact lens in a solution of the dye, in a swelling solvent and then in drying the colored lens obtained. Due to the non-hydrophilic nature (and the hard nature of the polymer material constituting the lens), there is no release of the dye diffused in the lens.
• the dyes recommended in this document are also dyes acidic, basic or direct classics.
• Document EP-A-122 771 describes a method of coloring a flexible hydrophilic contact lens which consists in impregnating the pores of an uncolored lens with an aqueous dispersion of a solubilized leuco sulfate with a vat dye and precipitating an insoluble dye in the pores.
• the precipitation of the dye requires hydrolysis in acid catalysis of the sulfate to produce the corresponding leuco derivative of the vat dye and the oxidation of the leuco derivative to its vat dye by exposure to air accelerated by UV radiation.
• Document EP-A-480 049 describes a method for coloring flexible hydrophilic contact lenses, which consists in immersing the uncolored lens, partly in contact with a mold, in an aqueous solution of a swelling dye and d '' a dye to detach the lens from the mold, swell the lens and infiltrate the dye into the lens, and immerse the treated lens in an aqueous solution of acid or oxidizing agent for fix the dye.
• the dyes used in this process are the vat dyes conventional in the technique considered.
• the colored lenses obtained by this process may have a release of the dye.
• the document JP 06049776 A describes a process for manufacturing an optical material which consists in:
• the colored material obtained is suitable for the manufacture of contact lenses. Besides the fact that the material is a rigid material, not hydrophilic, it is also colored in the mass. Thus, contact lenses made from this material are colored in full and it is not possible to obtain lenses colored only in part, for example in the part corresponding to the iris of the eye.
• this method does not allow coloring on demand of lenses from a stock of non-colored lenses.
• the present invention therefore relates to a method for coloring hydrophilic contact lenses, flexible, which is easy to implement industrially, which allows, if necessary, to color only specific parts of the lens and on request from '' a stock of non-colored lenses, and which supplies colored lenses which do not stain on contact with the lacrimal medium or lens disinfection solutions.
• the lenses obtained must be free from all cytotoxicity.
• a method of coloring a hydrophilic, flexible contact lens formed of a polymer material which comprises: - bringing the lens into contact with an aqueous solution containing a swelling solvent for the polymeric material and a dye chosen from the complex azo chromium salts and mixtures thereof; and - removing the lens from the solution.
• the complex azo chromium salts are generally metal salts, in particular alkali salts and preferably sodium salts.
• the preferred salts are the salts of formulas (I) and (II) below and their mixtures.
• complex chromium salts of formulas (I) and (II) are commercially available under the names ORASOL® 2GL (solvent Brown 42), ORASOL® 2RL (solvent Brown 43) and ORASOL® 6RL (solvent Brown 44).
• the amount of complex chromium salts in the coloring solution depends on the intensity of the shade desired for the colored contact lens. It is also adapted as a function of the amount of swelling solvent and of the hydrophilicity rate of the material constituting the lens.
• the content of complex chromium salts in the coloring solution is between 10 "5 % and 1% and better still between 10 " % and 0.5% by weight relative to the total weight of the solution.
• the swelling solvent can be any solvent allowing swelling of the polymer material constituting the lens as well as at least partial solubilization of the chromium complex (s), and which does not harm the optical and mechanical properties of the lens.
• the swelling solvents there may be mentioned alcohols, ketones, polyalkylene glycols such as ethylene glycol and methylsulfoxide.
• the preferred swelling solvents are alcohols such as methanol and ethanol and ketones such as acetone.
• the swelling solvent content of the coloring solution generally varies from 0.05 to 20% by volume, preferably 0.1 to 10% by volume relative to the total volume of the solution.
• the amount of swelling solvent is relatively small.
• the advantage of using these small amounts of swelling solvent is that it does not deform the geometry of the lens during the coloring treatment.
• the polymeric materials constituting the flexible, hydrophilic lenses according to the invention are all polymeric materials for flexible, hydrophilic contact lenses, capable of being swollen by a swelling solvent and colored by the complex azo chromium salts.
• Homopolymers and copolymers as follows: poly (hydroxyethyl methacrylates) (HEMA), poly (N-vinylpyrrolidones) (NVP), N-vinylpyrrolidone (NVP) / methyl methacrylate (MM A) copolymers, HEMA / MMA / methacrylic acid copolymers ( MA), HEMA / NVP copolymers, glycerol methacrylate copolymers /
• MMA polyvinyl alcohols, polyacrylamides and mixtures of these polymers and copolymers.
• the preferred polymeric materials according to the invention are NVP / MMA copolymers.
• hydrophilic lens is understood to mean a lens generally having a hydrophilicity level equal to or greater than
• the duration of contact with the coloring solution can vary from a few minutes to 2 hours depending on the composition of the coloring solution, the nature of the polymer material of the lens and the intensity desired for the coloring of the lens.
• the solution can be heated to a temperature which does not deteriorate the lens and which can reach 90 ° C., but which is generally of the order of 50 ° C.
• the lenses After removing the coloring solution, the lenses are generally rinsed with distilled water or a saline solution and sterilized for example in a physiological saline solution.
• ORASOL® 6RL brown dye was weighed in a container. The weighed quantity is poured into a beaker, and the container is rinsed with 90 ml of ethanol. The beaker is made up with 800 ml of distilled water and the solution is mixed.
• the coloring solution is stirred and the dye is diffused into the lenses.
• the lenses were left for 13 minutes in the coloring solution.
• the absorption spectrum of the contact lenses is then recorded after the week of storage.
• the absorption spectra obtained are superimposed exactly on those recorded for the same lenses before coloring. The dye therefore did not elute.
• the colored lenses obtained according to the method of the invention were subjected to 10 successive decontamination treatments in a 3% hydrogen peroxide solution.
• the absorption spectra (200-800 nm) of the lenses before and after coloring treatment are rigorously superimposable. No degradation or salting out of the dye is observed. It is the same for colored lenses according to the above method of the invention, subjected to 10 successive treatments by a solution marketed by the company ESSELOR, under the name CONCERTO®.
• Cytotoxicity test The cytotoxicity of the colored lenses of the invention was tested according to standards ISO 103993-5 (1992) - Biological Evaluation of Medical Devices - parts 5: tests for cytotoxicity: in vitro methods and ISO 9363-1 ( revised 06/02/1995) Optics and Optical Instruments - Contact lenses and Contact lens care products. Determination of cytotoxicity of contact lens materials and contact lens care products.
• the colored lenses according to the invention did not induce a cytotoxic effect.
• the transmission of the lenses is measured before and after the test.
• the lenses pass the test if relative TV ⁇ 5.
• Example 2 Example 1 was repeated, using the complex salts
• ORASOL® 2GL and 2RL Lentils colored brown were obtained which did not release and successfully passed test a) above.
• Comparative Examples RYTHMIC® hydrophilic lenses were stained with a process analogous to that of Example 1, but with coloring solutions containing conventional dyes.
• a LUNELLE® contact lens is available in a methyl methacrylate / N-vinylpyrrolidone copolymer, with a hydrophilicity level of
• a coloring solution is prepared by mixing 0.2 g of ORASOL® 6RL, 9 ml of ethanol and 90 ml of distilled water.
• a colored lens is obtained on the zone corresponding to the wearer's iris.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Ophthalmology & Optometry (AREA)
• Mechanical Engineering (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Eyeglasses (AREA)
• Treatments Of Macromolecular Shaped Articles (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 1999
  • 1999-01-28 FR FR9900958A patent/FR2789081B1/fr not_active Expired - Fee Related
• 2000
  • 2000-01-19 JP JP2000596397A patent/JP2002535733A/ja not_active Withdrawn
  • 2000-01-19 EP EP00900606A patent/EP1078284A1/fr not_active Withdrawn
  • 2000-01-19 WO PCT/FR2000/000102 patent/WO2000045198A1/fr not_active Application Discontinuation
  • 2000-09-28 NO NO20004870A patent/NO20004870D0/no not_active Application Discontinuation

Non-Patent Citations (1)

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