MXPA00004611A - Methods and compositions for manufacturing tinted ophthalmic lenses - Google Patents

Abstract

The invention relates to a process for the manufacture of tinted ophthalmic moldings comprising the steps of:(a) providing a water soluble polymer precursor having cross-linkable or polymerizable groups;(b) providing a pigment dispersion comprising an inorganic or organic pigment and a dispersing agent;(c) mixing the pigment dispersion with the polymer precursor to form a tinted prepolymerization mixture;(d) dispensing the tinted prepolymerization mixture into a mold;(e) applying radiation to the tinted prepolymerization mixture in the mold, thereby cross-linking or polymerizing the polymer precursor and entrapping the pigment within the polymeric network of the resultant ophthalmic molding, and (f) opening the mold so that the ophthalmic molding can be removed from the mold. According to the process, tinted ophthalmic moldings, particularly full-body tinted soft contact lenses having improved properties, are prepared with an improved efficiency.

Description

METHODS AND COMPOSITIONS TO MANUFACTURE OFT LMIC LENSES HANDLED This invention relates extensively to the incorporation of radiation absorbing additives into polymeric articles. In a preferred embodiment, this invention relates to compositions and methods for manufacturing visibly dyed contact lenses ("full body"), which comprise pigments that are strongly resistant to inactivation during photopolymerization or photocrosslinking. A number of dyes have been incorporated into ophthalmic lenses, such as contact lenses, for a variety of reasons. Two popular types of dyes include ultraviolet (UV) absorbing agents, and visible light absorbing agents. A common reason for incorporating dyes into contact lenses is to produce a lens that changes the apparent or perceived color of the user's iris. Another reason for dyeing a contact lens is to make it possible for the consumer to easily locate the lens in a transparent solution inside a storage, disinfection, or lens cleaning container. The dyeing of a lens for this purpose is called "visibly dying" the lens. Visible dyeing can be done by applying a dye to a surface area, cr-by applying the dye to the front surface complete lens. Alternatively, the dye can be incorporated into the full body of the polymer matrix of the lens. There have been a number of patents and published patent applications related to the dyeing of contact lenses, or with the manufacture of contact lenses that change the color of the wearer's iris. However, the known processes are still not completely satisfactory, for example, with respect to the production efficiency and / or the quality of the products obtained. Accordingly, there is still a need for a method for manufacturing a visibly tinted contact lens, i.e., dyed throughout the body, with improved efficiency, for example, by minimizing in-line production steps. In addition, there is a demand for tinted ophthalmic lenses with improved properties, for example, with respect to bleaching resistance, mechanical strength, and leaching or migration of dye out of the lens. These and other objects and advantages are achieved by the present invention. Accordingly, the present invention, in one embodiment, relates to a process for manufacturing an ophthalmic radiation absorptive molded article, which comprises the steps of: (a) providing a water soluble polymer precursor having crosslinkable groups or polymerizable; (b) providing a pigment dispersion comprising an inorganic or organic pigment, and a dispersing agent; (c) mixing the pigment dispersion with the polymer precursor to form a dyed prepolymerization mixture, d dosing the dyed prepolymerization mixture in a mold, (e) applying radiation to the dye prepolymerization mixture in the mold, thus crosslinking or polymerizing the polymer precursor, and trapping the pigment within the polymer network of the resulting ophthalmic molded article, and (f) opening the mold, so that the ophthalmic molded article can be removed from the mold.

The terms "polymer precursor" and "prepolymer", as used herein, refer to a crosslinkable or polymerizable material. Preferably, the polymer precursor is vinyl-functional, that is, the polymer precursor includes one or more carbon-carbon double bonds. (i) POLYMER PRECURSOR In a preferred embodiment, the polymer precursor is a prepolymer having a weight average molecular weight. at least about 2000. The prepolymer more preferably has a weight average molecular weight of from about 10,000 to about 300,000, and still more preferably about 10., 000 to approximately 200,000. It is more preferred that the prepolymer have a weight average molecular weight of from about 50,000 to about 100,000. According to the invention, the polymer precursor is soluble in water. The criterion that the polymer is soluble in water, denotes in particular that the polymer precursor is soluble in a concentration of about 3 to 90 percent by weight, preferably about 5 to 60 percent by weight, especially of about 10 to 60 weight percent, in a substantially aqueous solution. As much as possible in an individual case, concentrations of the polymer precursor greater than 90 percent according to the invention are also included. The prepolymer used according to the invention includes polymerizable or crosslinkable groups, preferably crosslinkable groups. "Crosslinkable groups" denotes customary crosslinkable groups well known to the person skilled in the art, such as, for example, photo-crosslinkable or thermally crosslinkable groups. Crosslinkable groups, such as those already proposed for the preparation of contact lens materials, are especially suitable. These include especially, but not exclusively, groups that comprise carbon-carbon double bonds. To demonstrate the wide variety of suitable crosslinkable groups, the following crosslinking mechanisms are mentioned herein, purely by way of example: radical polymerization, 2 + 2 cycloaddition, Diels-Alder reaction, ROMP (Ring Opening Metathesis Polymerization) , vulcanization, cationic crosslinking, and epoxy hardening. The prepolymer used according to the invention preferably comprises crosslinkable groups in an amount of about 0.5 to about 80 percent equivalents, based on the equivalents of the monomers forming the polymeric base structure, especially about 1 to 50. percent, preferably from about 1 to 25 percent, preferably from about 2 to 15 percent, and especially preferably from about 3 to 10 percent. Also especially preferred are amounts of crosslinkable groups of from about 0.5 to about 25 percent equivalents, especially from about 1 to 15 percent, and especially preferably from about 2 to 12 percent, based on the equivalents of the monomers forming the polymeric base structure. A preferred criterion for the ownership of a prepolí-_ For the process according to the invention, it is that it is a crosslinkable prepolymer, but that the prepolymer is not crosslinked, or at least not substantially crosslinked. In addition, the prepolymer is conveniently stable in the non-crosslinked state, so that it can be subjected to purification. The prepolymers are preferably used in the form of a pure solution in the process according to the invention. The prepolymers can be converted to the form of a pure solution by conventional methods, for example, in the manner disclosed hereinafter. The polymerizable or crosslinkable materials useful in accordance with the present invention include a wide variety of materials known in the art. Preferred polymeric materials are those that are biocompatible, especially ophthalmically compatible, and transparent. A preferred polymer precursor material is a crosslinkable polyvinyl alcohol. However, it is also possible to use in the process other water-soluble prepolymers comprising a polymeric base structure, and also crosslinkable groups. A particularly preferred class of polymeric materials are polyvinyl alcohols, especially those disclosed in U.S. Patent No. 5,508,317, issued to the inventor Beat Muller, and originally assigned to Ciba-Geigy Corporation. The disclosure of U.S. Patent No. 5,508,317 is incorporated herein by reference. The preferred group of polyvinyl alcohol prepolymers includes derivatives of a polyvinyl alcohol having a weight average molecular weight of at least about 2,000 which, based on the number of polyvinyl alcohol hydroxyl groups, includes from about 0.5 percent to about 80 percent of units of formula I: CH, CH, CH CH o o (i: CH R, wherein R is alkylene having up to 8 carbon atoms, R: is hydrogen or lower alkyl, and R 2 is an olefinically unsaturated copolymerizable electron attracting radical, preferably having up to 25 carbon atoms, preferably a radical of olefinically unsaturated acyl of the formula R 3 -CO-, wherein R 3 is an olefinically unsaturated copolymerizable radical having from 2 to 24 carbon atoms, preferably from 2 to 8 carbon atoms, more preferably from 2 to 4 atoms of carbon. It should be noted that molecular weights, as used herein, are weight average molecular weights, Mw, unless otherwise specified. In another embodiment, the radical Ri is a radical of the formula II: -CO-NH- (R4-NH-CO-O) q-Rs-0-CO-R3 (II) wherein q is zero or one, R4 and R5 are each independently alkylene having from 2 to 8 carbon atoms, arylene having from 6 to 12 carbon atoms, a saturated divalent cycloaliphatic group having from 6 to 10 carbon atoms; carbon, arylenealkylene or alkylenearylene having from 7 to 14 carbon atoms, or arylalkylenearylene having from 13 to 16 carbon atoms, and R3 is as defined above. A more preferred prepolymer useful in accordance with the present invention is a derivative of a polyvinyl alcohol having a weight average molecular weight of at least about 2,000 which, based on the number of polyvinyl alcohol hydroxyl groups, includes about 0.5. percent to about 80 percent of units of formula III: CH2 CH2"CH CH O O (I I I) CH R, N \ (CONH- (4NHCOO) "- R5-0) p - C0R3 wherein R is alkylene having up to 8 carbon atoms, Rx is hydrogen or lower alkyl, p is zero or one, q is zero or one, R3 is an olefinically unsaturated copolymerizable radical having from 2 to 8 carbon atoms, and R and R5 are each, independently of the other, lower alkylene having from 2 to 8 carbon atoms, arylene having from 6 to 12 carbon atoms, a saturated divalent cycloaliphatic group having from 7 to 14 carbon atoms, or arylene-alkanarylene having 13 to 16 carbon atoms. R as lower alkylene has up to 8 carbon atoms, and can be straight or branched chain. Suitable examples include octylene, hexylene, pentylene, butylene, propylene, ethylene, methylene, 2-propylene, 2-butylene, and 3-pentylene. Preferably, R as lower alkylene has up to 6, and especially preferably up to 4 carbon atoms. The meanings of methylene and butylene are especially preferred. Ri is preferably hydrogen or lower alkyl having up to 7, especially up to 4 carbon atoms, especially hydrogen. R or R = as lower alkylene preferably have from 2 to 6 carbon atoms, and are especially straight chain. Suitable examples include propylene, butylene, hexylene, dimethylethylene, and especially preferably ethylene.

R 4 or R 5 as arylene is preferably phenylene which is unsubstituted or substituted by lower alkyl or lower alkoxy, especially 1,3-phenylene or 1,4-phenylene or methyl-1,4-phenylene. A saturated divalent cycloaliphatic group R 4 or R 5 is preferably cyclohexylene or cyclohexylene-lower alkylene, for example cyclohexylenemethylene, which is unsubstituted or substituted by one or more methyl groups, such as, for example, trimethylcyclohexylene ethylene, for example the radical of divalent isophorone. The arylene alkyl arylene or arylene alkyl unit R or R5 is preferably phenylene, unsubstituted or substituted by lower alkyl or lower alkoxy, and the alkylene unit thereof is preferably lower alkylene, such as methylene or ethylene, especially methylene . Accordingly, these radicals R4 or Rs are preferably phenylenemethylene or methylenephenylene. R or R5 as arylene-alkylene-arylene is preferably phenylene-lower alkylene-phenylene having up to 4 carbon atoms in the alkylene unit, for example phenylene-ethylene-phenylene. The radicals R4 and Rs are each, independently of the other, preferably alkylene having from 2 to 6 carbon atoms, phenylene, unsubstituted or substituted by lower alkyl, cyclohexylene, or lower cyclohexylenealkylene, insoluble. or substituted by lower alkyl, lower phenylene alkylene, lower phenylene alkylene, or lower phenylene alkylene phenylene. As used herein, the term "lower", as used in connection with radicals and compounds, denotes radicals or compounds having up to 7 carbon atoms, preferably up to 4 carbon atoms, unless otherwise defined. Lower alkyl has especially up to 7 carbon atoms, preferably up to 4 carbon atoms, and is, for example, methyl, ethyl, propyl, butyl, or tertiary butyl. In a similar manner, lower alkoxy has especially up to 7 carbon atoms, preferably up to 4 carbon atoms, and is, for example, methoxy, ethoxy, propoxy, butoxy, or tertiary butoxy. The olefinically unsaturated copolymerizable radical R3 is preferably alkenyl having from 2 to 24 carbon atoms, especially alkenyl having from 2 to 8 carbon atoms, and especially preferably alkenyl having from 2 to 4 carbon atoms, for example ethenyl, -propenyl, 3-propenyl, 2-butenyl, hexenyl, octenyl, or dodecenyl R 3 is preferably ethenyl and 2-propenyl, such that the group -CO-R 3 is the acyl radical of acrylic or methacrylic acid. The divalent group -R4-NH-CQ-rO- is present when q is one, and is absent when q is zero. the prepolymers where q is zero. The divalent group -CO- H- (R4-NH-CO-0) q- R5-0- is present when p is one, and is absent when p is zero. Prepolymers are preferred where p is zero. In the prepolymers where p is one, the index q is preferably zero. Especially preferred are the prepolymers wherein p is one, the index q is zero, and R5 is lower alkylene. Accordingly, a preferred prepolymer according to the invention is especially a derivative of a polyvinyl alcohol having a molecular weight of at least about 2,000 which, based on the number of hydroxyl groups of the polyvinyl alcohol, comprises from about 0.5 to about 80 percent of units of formula III, wherein R is lower alkylene having up to 6 carbon atoms, p is zero, and R3 is alkenyl having from 2 to 8 carbon atoms. A further preferred prepolymer according to the invention is a derivative of a polyvinyl alcohol having a molecular weight of at least about 2,000 which, based on the number of hydroxyl groups of the polyvinyl alcohol, comprises from about 0.5 to about 80% by weight. one hundred units of the formula III, wherein R is alkylene having up to 6 carbon atoms, p is one, q is zero, Rs is alkylene having 2 to 6 carbon atoms, and R3 it is alkenyl having from 2 to 8 carbon atoms. Yet a further preferred prepolymer according to the invention is a derivative of a polyvinyl alcohol having a molecular weight of at least about 2,000 which, based on the number of hydroxyl groups of the polyvinyl alcohol, comprises from about 0.5 to about 80. per cent of units of the formula III, wherein R is alkylene having up to 6 carbon atoms, p is one, q is one, R is alkylene having 2 to 6 carbon atoms, phenylene, unsubstituted or substituted by alkyl lower, cyclohexylene, or lower cyclohexylenealkylene, unsubstituted or substituted by lower alkyl, lower phenylene alkylene, lower alkylene phenylene, or lower phenylene alkylene phenylene, R 5 is alkylene having from 2 to 6 carbon atoms, and R 3 is alkenyl which It has 2 to 8 carbon atoms. The prepolymers according to the invention are preferably polyvinyl alcohol derivatives having a molecular weight of at least about 2,000 which, based on the number of hydroxyl groups of the polyvinyl alcohol, comprise from about 0.5 to about 80 percent, especially from about 1 to 50 percent, preferably from about 1 to 25 percent, preferably from about 2 to 15 percent, and especially preferably from about 3 to 10 percent of units of the formula III. The prepolymers of according to the invention provided for the manufacture of contact lenses comprise, based on the group of hydroxyl groups of the polyvinyl alcohol, especially from about 0.5 to about 25 percent, especially from about 1 to 15 percent, and particularly preferably from about 2 to 12 percent of units of formula III. The polyvinyl alcohols that can be derived according to the invention preferably have a weight average molecular weight of at least 10., 000 As an upper limit, polyvinyl alcohols can have a molecular weight of up to 1,000,000. Preferably, the polyvinyl alcohols have a molecular weight of up to 300,000, especially up to about 100,000, and especially preferably up to about 50,000. Suitable polyvinyl alcohols according to the invention typically have a structure of poly (2-hydroxy) ethylene. The polyvinyl alcohols derived according to the invention, however, can also comprise hydroxyl groups in the form of 1,2-glycols, such as 1,2-dihydroxyethylene copolymer units, as can be obtained, for example, by hydrolysis Alkaline of vinyl acetate / vinylene carbonate copolymers. In addition, the polyvinyl alcohols derived according to the invention may also comprise small proportions, for example up to 20 percent, preferably up to 5 percent of copolymer units of ethylene, propylene, acrylamide, methacrylamide, dimethacrylamide, hydroxyethyl methacrylate, methyl methacrylate, methyl acrylate, ethyl acrylate, vinylpyrrolidone, acrylate of hydroxyethyl, allyl alcohol, styrene, or comonomers used by similar custom. Commercially available polyvinyl alcohols can be used, such as, for example, Vinol® 107 produced by Air Products (Molecular Weight = 22,000 to 31,000, 98-98.8 percent hydrolysed), Polysciences 4397 (Molecular Weight = 25,000, 98.5 percent hydrolysed) , BF 14 produced by Chan Chun, Elvanol® 90-50 produced by DuPont, UF-120 produced by Unitika, Mo iol® 3-83, 4-88, 10-98, and 20-98 produced by Hoechst. Other manufacturers are, for example, Nippon Gohsei (Gohsenol®), Monsanto (Gelvatol®), Wacker (Polyviol®), and the Japanese manufacturers Kuraray, Denki, and Shin-Etsu. The molecular weights referenced herein are weight average weights, Mw, determined by gel permeation chromatography, unless otherwise specified. As already mentioned, it is also possible to use hydrolyzed vinyl acetate copolymers, which can be obtained, for example, in the form of ethylene / vinyl acetate (EVA), or vinyl chloride / vinyl acetate, N-vinylpyrrolido- na / vinyl acetate and aleic acid anhydride / ethyl acetate hydrolyzed vinyl. The polyvinyl alcohol is usually prepared by hydrolysis of the corresponding homopolymer vinyl polyacetate. In a preferred embodiment, the polyvinyl alcohol derivative according to the invention comprises less than 50 percent vinyl polyacetate units, especially less than 20 percent polyvinyl acetate units. The preferred amounts of residual acetate units in the polyvinyl alcohol derived according to the invention, based on the sum of vinyl alcohol units and acetate units, are from about 3 to 20 percent, preferably from about 5 to 16 percent, and especially from about 10 to 14 percent. In a preferred embodiment, the polymer precursor comprising units of formula I or III, has a weight average molecular weight of at least about 2,000. More preferably, the polymer precursor has a weight average molecular weight of from about 10,000 to about 300,000. A more preferred weight average molecular weight of the polymer precursor mixtures is from about 10,000 to about 200,000. Still more preferred is a weight average molecular weight of from about 50,000 to about 100,000. The prepolymers comprising units of the formula I or III, can be prepared in a manner known per se. A suitable process for the manufacture of these prepolymers is disclosed, for example, in U.S. Patent No. 5,508,317. The prepolymers comprising units of the formula I or III, in addition, can be purified by a variety of processes, which are likewise disclosed, for example, in U.S. Patent No. 5,508,317. According to step (a) of the process of the invention, these polymer precursors that are liquid or easily meltable, can be provided substantially free of solvents. However, the polymer precursor is preferably in solution with a solvent. Suitable solvents for the polymer precursor include water, alcohols, such as lower alkanols, for example ethanol or methanol, also carboxylic acid amides, such as dimethylformamide, or dimethyl sulfoxide, and also a mixture of suitable solvents, such as , for example, a mixture of water with an alcohol, such as, for example, a water / ethanol or water / ethane1 mixture. Preferably, the polymer precursor according to step (a) is provided in the form of an aqueous solution, and more preferably in the form of a pure aqueous solution, or a solution of an artificial tear fluid.

Especially preferred concentrations of the polymer precursor in solution are about 15 a. about 50 weight percent, especially from about 15 to about 40 weight percent, and in particular from about 20 weight percent to about 40 weight percent, based on each case in the total solution. The aqueous solution of the polymer precursor can be a salt solution, especially a solution having an osmolarity of about 200 to 450 milliosmoles per 1000 milliliters (unit: mOsm / 1), preferably an osmolarity of about 250 to 350 mOsm / 1. , especially of about 300 mOsm / 1, or in mixtures of water or aqueous salt solutions with physiologically tolerable polar organic solvents, such as, for example, glycerol. Aqueous salt solutions are suitably solutions of physiologically tolerable salts, such as pH regulating salts customary in the field of contact lens care, for example phosphate salts, or isotonizing agents customary in the field of contact lens care, such as, especially, alkali halides, for example sodium chloride, or solutions of mixtures thereof. An example of an especially suitable salt solution is an artificial tear fluid, preferably with regulated pH, which, with respect to the pH value and osmolarity, is adapted to the natural tear fluid, for example, a sodium chloride solution which is not regulated, or which preferably has the pH regulated, for example, by a phosphate regulator, and which has an osmolarity corresponding to the osmolality of the human tear fluid . The substantially aqueous solution of the polymer precursor defined above is preferably a pure solution, which means a solution that is free or essentially free of undesired constituents. The viscosity of the prepolymer solution in the substantially aqueous solution should be sufficient to allow reasonable processability. Accordingly, the viscosity of the solution of the polymer precursor should be sufficiently low to allow dosing through the selected metering tip in the female mold half, at a reasonably fast speed, in order to minimize the cycle time, and in order to minimize product defects (e.g., defects associated with bubble formation). The polymer precursor or polymer precursor solution according to step (a) is preferably one which does not comprise, or which substantially does not comprise, undesired constituents which have to be removed after a crosslinking operation. Undesirable constituents include monomeric, oligomeric, or polymeric starting materials used for the preparation of the prepolymer. By Consequently, the concentration of the undesirable constituents after crosslinking is an amount that is lower than that which would cause ocular irritation or damage after normal use in the ocular environment. A particular feature of this preferred embodiment of the process according to the invention is that extraction of undesired constituents is not necessary following cross-linking. (ii) INORGANIC OR ORGANIC PIGMENT The class of radiation absorbing additives useful in accordance with the present invention are inorganic or organic pigments, or derivatives thereof. Preferred is the use of organic pigments, specifically phthalocyanine pigments, more specifically copper phthalocyanine pigments, and more specifically blue copper phthalocyanine pigments, for example the Pigment of the Blue Color Index 15, Constitution Number 74160. The amount of pigment necessary for a particular application may vary within wide limits, depending, in part, on the dimensions of the desired final product and the desired transmission of visible and / or ultraviolet light. For example, the amount of pigment is chosen such that the optical transmission of the final lens is, for example, = 80 percent, preferably = 90 percent, more preferably 92 to 99.5 percent, and in a particular way preferable from 95 to 99 percent. The transmission values given above refer to a lens center thickness of 100 microns, and to the wavelength of the maximum absorption of the respective pigment. The amount of pigment necessary to achieve the desired optical transmission is conveniently chosen in such a way that the weight percentage of the pigment, based on the total weight of the polymer precursor, and the optional comonomers present in the prepolymerization mixture in accordance with c), be approximately 0.0001 to 0.05 percent. Preferably, this weight percentage of the pigment is from about 0.0001 to 0.02 percent. More preferably, this weight percentage of the pigment is from about 0.0001 to 0.01 percent. The particle size of the pigment can vary within wide limits. In general, the particle size should be small enough to avoid scattering of light, which is clinically significant for the degree of intensity of dye required. It has been proved that an average particle size of = 1 miera is convenient, suitably of =. 0.6 microns, preferably from 0.05 to 0.6 microns, and in a particularly preferable way from 0.05 to 0.5 microns. In general, the pigment is provided in the form of an aqueous dispersion comprising the pigment and at least one suitable dispersing agent. Common dispersing agents suitable for this purpose are known to the expert in the field of dyes and pigments. In addition, in a surprising manner, it has been discovered that the water-soluble polymer precursor according to (a), or any water-soluble polymer that is physiologically acceptable, can be used as a surfactant to aid dispersion of the hydrophobic pigment particles. Accordingly, it is preferred to use a polymer precursor of the invention, or a water-soluble physiologically acceptable polymer as the dispersing agent, and to omit another additive. Examples of the water-soluble physiologically acceptable polymers, in addition to the polymer precursor according to (a), which can be used as a surfactant, are a polyacrylic acid or a polyvinyl alcohol that does not have a crosslinkable or polymerizable group, for example a polyvinyl alcohol mentioned above as the starting material for the polymer precursor according to (a). The pigment content of the aqueous pigment dispersion employed according to step (b) can vary within wide limits. In general, a pigment content of about 1 to 70 percent by weight, preferably 5 to 60 percent by weight, and more preferably 5 to 50 percent by weight, has been found to be valuable in each case. in relation to the weight of the entire dispersion. When a water-soluble physiologically acceptable polymer is used, particularly a non-polymerizable polyvinyl alcohol, or a prepolymer according to (a), as the dispersing agent for the pigment, this polymer is conveniently present in an amount of 1 to 60 weight percent, preferably 5 to 40 weight percent, more preferably 10 to 40 weight percent percent by weight, and most preferably 10 to 30 percent by weight, in each case based on the weight of the entire pigment dispersion. The initial dispersion of the pigment can be further diluted by the addition, for example, of water or of an aqueous solution of the polymer precursor according to (a), before preparing the prepolymerization mixture according to (c). In a preferred embodiment of step (b) of the process, a phthalocyanine pigment is provided in the form of an aqueous dispersion comprising the pigment and one or more water-soluble polymer dispersion agents selected from the group consisting of a precursor of polymer according to (a), a polyacrylic acid, and a non-crosslinkable polyvinyl alcohol. More preferably, the phthalocyanine pigment is provided in the form of an aqueous dispersion comprising the pigment and one or more water-soluble polymer dispersion agents, selected from the group consisting of a non-crosslinkable polyvinyl alcohol, and a polymer precursor according to (a), which may be different, or preferably identical to that employed in step (a).

When a water-soluble physiologically acceptable polymer, for example, a non-crosslinkable polyvinyl alcohol, or a prepolymer according to (a), is used as the dispersing agent for the pigment in step (b), this polymer is preferably purify in advance as described above for the polymer precursor. Accordingly, the dispersion of the accent pigment with step (b) does not comprise, or substantially does not comprise, undesired constituents mentioned above, which have to be removed after the crosslinking operation. The aqueous pigment dispersion according to e? L step (b), is prepared, for example, simply by mixing water, the pigment, and the dispersing agent in a suitable device, for example, in a high speed mixer, in a roller or ball mill, or by using an ultrasonic probe. In some cases, it may be appropriate to filter the pigment dispersion according to step (b), or the prepolymerization mixture according to step (c), before further processing, in order to exclude the pigment particles. having a particle size that exceeds the aforementioned limits. (iii) PHOTOINICIATORS In the case of photocrosslinking, it is appropriate to add a crosslinking initiator (preferably a photoinitiate). photo-crosslinker) that can initiate crosslinking. The photoinitiator is added, for example, to the polymer precursor according to step (a), or preferably to the prepolymerization mixture according to step (c). A reasonable amount of mixture is preferred to distribute the photoinitiator in a substantially uniform manner throughout the polymer precursor solution. Photoinitiators are known to the person having ordinary skill in the art, and include, without limitation, benzoin methylether, 1-hydroxycyclohexylphenyl ketone, and the DAROCUR® or IRGACUR types, for example DAROCUR® 1173 or IRGACUR® 2959, available from Ciba-Geigy Corporation (Ardsley, New York). The amount of photoinitiator can be chosen within wide limits, having been proven to be convenient an amount of up to 0.05 grams / gram of polymer, and especially of up to 0.003 grams / gram of polymer. The crosslinking can then be triggered by actinic radiation, such as, for example, ultraviolet light, or ionizing radiation, such as, for example, gamma radiation or X radiation. (iv) C0M0N0MER0S It is preferable to carry out the crosslinking process according to the invention, without the addition of a comonomer, for example a vinyl comonomer. However, a vinyl comonomer can be used in addition to the photoretreatment, and the The comonomer can be hydrophilic or hydrophobic, or a mixture of a hydrophobic vinyl monomer and a hydrophilic one. Suitable vinyl comonomers include those customarily used in the manufacture of contact lenses. A hydrophilic vinyl monomer denotes a monomer that normally produces as the homopolymer, a polymer that is soluble in water or that can absorb at least 10 percent by weight of water. In an analogous manner, a hydrophobic vinyl monomer denotes a monomer which normally produces, like the homopolymer, a polymer which is insoluble in water, and which can absorb less than 10 weight percent water. In general, about 0.01 to 80 units of a typical vinyl comonomer react per unit of formula I or III. If a vinyl comonomer is used, the crosslinked polymers according to the invention preferably comprise from about 1 to 15 percent, especially preferably from about 3 to 8 percent of units of the formula I or III, based on in the number of hydroxyl groups of the polyvinyl alcohol, which react with from about 0.1 to 80 units of the vinyl monomer. The proportion of vinyl comonomers, if used, is preferably from 0.5 to 80 units per unit of formula I, especially from 1 to 30 units per unit of formula I, and especially preferably from 5 to 20. units per unit of formula I. It is also preferable to use a hydrophobic vinyl comonomer, or a mixture of a hydrophobic vinyl comonomer with a hydrophilic vinyl comonomer, the blend comprising at least 50 weight percent of a hydrophobic vinyl comonomer. In this way, the mechanical properties of the polymer can be improved - without substantially lowering the water content. However, in principle, both conventional hydrophobic vinyl comonomers and conventional hydrophilic vinyl comonomers are suitable for copolymerization with the polyvinyl alcohol comprising the groups of the formula I. Suitable hydrophobic vinyl comonomers include, but are not limited to, alkyl acrylates and methacrylates of 1 to 18 carbon atoms, acrylamides and alkyl methacrylamides of 3 to 18 carbon atoms, acrylonitrile, methacrylonitrile, alkanoates of 1 to 18 atoms. of vinyl carbon, alkenes of 2 to 18 carbon atoms, haloalkenes of 2 to 18 carbon atoms, styrene, alkyl of 1 to 6 carbon atoms-styrene, vinylalkylethers, wherein the alkyl fraction contains 1 to 6 atoms carbon, acrylates and perfluoroalkyl methacrylates of 2 to 10 carbon atoms, or correspondingly partially fluorinated acrylates and methacrylates, perfluoroalkyl acrylates and methacrylates of 3 to 12 carbon atoms ethylthiocarbonylaminoethyl, acryloxy- and methacryloxy-alkylsiloxanes, N-vinylcarbazole, alkyl esters of 1 to 12 carbon atoms of maleic acid, fumaric acid, itaconic acid, mesaconic acid, and the like. For example, alkyl esters of 1 to 4 carbon atoms of vinyl unsaturated carboxylic acids having from 3 to 5 carbon atoms, or vinylesters of carboxylic acids having up to 5 carbon atoms are preferred. Examples of suitable hydrophobic vinyl comonomers include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, vinyl acetate. , vinyl propionate, vinyl butyrate, vinyl valerate, styrene, chloroprene, vinyl chloride, vinylidene chloride, acrylonitrile, 1-butene, butadiene, methacrylonitrile, vinyltoluene, vinylethylether, perfluorohexylethylcarbonylaminoethyl methacrylate, isobornyl methacrylate, trifluoroethyl methacrylate , hexafluoroisopropyl methacrylate, hexafluorobutyl methacrylate, tris-trimethylsilyloxy-silyl-propyl methacrylate, 3-methacryloxypropylpentamethyldisiloxane, and bis (methacryloxypropyl) tetramethyldisiloxane. The preferred hydrophobic vinyl comonomers are methyl methacrylate and vinyl acetate. The suitable hydrophilic vinyl comonomers include, without limitation, lower alkyl acrylates and methacrylates substituted by hydroxyl, acrylamide, methacrylamide, lower alkyl acrylamides and methacrylamides, ethoxylated acrylates and methacrylates, lower alkyl substituted by hydroxyl, lower alkyl vinyl ethers substituted by hydroxyl, sodium ethylene sulfonate, sodium styrene sulfonate, 2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrole, N-vinyl succinimide, N-vinylpyrrolidone, 2- or 4-vinylpyridine, acrylic acid, methacrylic acid, amino- acrylates and methacrylates (including the term "amino" also to quaternary ammonium), mono-lower alkyl- »amino- or di-lower alkyl-amino-lower alkyl, allyl alcohol, and the like. For example, substituted (meth) acrylates of 2 to 4 carbon atoms are preferred per hydroxyl, the N-vinyl lactams from 5 to 7 members, the N, N-dialkyl (meth) acrylamides of 1 to 4 carbon atoms, and vinyl unsaturated carboxylic acids having a total of 3 to 5 carbon atoms. | Examples of hydrophilic vinyl comonomers Suitable include hydroxyethyl methacrylate, hydroxyethyl acrylate, acrylamide, methacrylamide, dimethylethylacrylamide, allyl alcohol, vinylpyridine, vinylpyrrolidone, glycerol methacrylate, N- (1, l-dimethyl-3-oxobutyl) acrylamide, and the like. The preferred hydrophilic vinyl comonomers are methacrylate 2-hydroxyethyl, N-vinylpyrrolidone, and acrylamide. (v) PREPARATION OF A DYED PREPOLIMERIZATION MIXTURE AND MANUFACTURE OF A DYED LYMPAL LENS FROM THE SAME According to step (c) of the process of the invention, a dyed prepolymerization mixture can be formed by mixing the amounts suitable aforementioned of a polymer precursor according to (a), a pigment dispersion according to (b), and optionally a photoinitiator and / or one or more comonomers. In the preferred process of the invention, the prepolymerization mixture comprises a photoinitiator, but does not have an additional vinyl comonomer. The dyed prepolymerization mixture thus obtained can be processed in a manner known per se to form molded articles, especially contact lenses, for example, by photocrosslinking the prepolymerization mixture in a suitable contact lens mold. For the introduction of the dyed prepolymerization mixture of the invention into a mold, processes known per se can be employed, such as, especially, conventional introduction, for example, by means of drip introduction. The liquid mixture that is dosed into the mold is preferably an aqueous solution. For example, it can be photoreticularly from about 15 to 50 weight percent, preferably from 15 to 40 weight percent, and more preferably from 20 to 40 weight percent, and most preferably from 40 weight percent aqueous solution. If there are vinyl comonomers present, the aforementioned comonomers in the mentioned amounts are suitable. The vinyl comonomers that may be conveniently present are first mixed with the polymer precursor of the invention, and then introduced into the mold. Suitable molds or mold halves can be made from disposable or recyclable polymeric materials (eg, polypropylene or polystyrene) that transmit the radiation of the chosen wavelength sufficient to crosslink or polymerize the polymer precursor. In an alternative way, reusable molds can be made from materials such as quartz, sapphire, or metals. When the molded articles to be produced are contact lenses, they can be produced in a manner known per se, for example, in a conventional "centrifugal casting mold", as described, for example, in the United States of America Number 3,408,429.

However, two-sided molding processes are preferred (DSM), such as those described in the Patent of the States United States of America Number 4,347,198, which is incorporated as a reference. Two-sided molding processes typically use a concave mold half (also known as "female" or "front surface"), which is coupled with a convex mold half (also known as "male" or "back surface"). Normally, in the two-sided molding process, the monomer or liquid polymer precursor is dosed in the female mold half, the male mold half is fixed to the female mold half, and light is applied (e.g. ultraviolet) to initiate polymerization or crosslinking, and form a solid lens. Photocrosslinking can be induced in the mold, for example, by actinic radiation, for example ultraviolet light, or ionizing radiation, for example gamma radiation or X-rays. It should be emphasized that, according to the invention, the crosslinking can be carried out in a very short time, for example in =. 60 minutes, conveniently in =. 20 minutes, preferably at =. 10 minutes, especially in =. 5 minutes, more especially in =. 1 minute, and very especially in =. 30 seconds . The opening of the mold, in such a way that the molded article can be removed from the mold, can be carried out in a manner known per se. Particular preferred embodiments of the process of the invention are shown in the examples and in the claims. A further embodiment of the invention relates to stained ophthalmic molded articles, particularly dyed contact lenses, which can be obtained according to the process of the invention, wherein the definitions and preferences given above apply. When the molded article produced according to the invention is a contact lens, and when the latter has been produced from a prepolymerization mixture comprising previously purified components, then the crosslinked product does not contain problematic impurities either. Therefore, a subsequent extraction is not necessary. Since the crosslinking is carried out in a substantially aqueous solution, subsequent hydration is also not necessary. The contact lenses that can be obtained according to this process, therefore, are distinguished, according to a convenient modality, by the fact that they are suitable for their designated use without extraction. In connection with this, it is understood that the designated use means especially that contact lenses can be inserted into the human eye. The contact lenses that can be obtained according to the invention have a range of unusual and extremely convenient properties. Of these properties, it can be mentioned, for example, its excellent tolerability by the human cornea, which is based on a balance of water content, oxygen permeability, and mechanical properties. Moreover, the contact lenses of the invention have a high mechanical strength, and exhibit a particularly high degree of dimensional stability. No changes in shape could be discerned, even after autoclaving, for example, at approximately 120 ° C. In general, the dyed contact lenses are stained substantially uniformly throughout the lens body. The contact lenses of the invention are furthermore resistant to bleaching, and, due to a quantitative incorporation of the pigment in the lens matrix, do not show leaching or migration of the pigment out of the lens. In addition, the contact lenses are optically clear and transparent, and have transmission values% T that are equivalent to those of the unstained lenses. It can also be emphasized that contact lenses_ dyed throughout the body of the invention, can be produced in a very simple and efficient way, compared to the prior art. This is the result of several factors. First, the starting materials are inexpensive to obtain or prepare. Second, there is the advantage that the prepolymers are surprisingly stable, so that they can be subjected to a high degree of purification. Accordingly, since it is possible to use the crosslinking of a "purified" polymer, and in addition, since the pigment is trapped quantitatively within the polymer matrix during the crosslinking and / or polymerization step, virtually no purification is required. subsequent, such as, especially, the complicated extraction of the pigment and / or of the unpolymerized constituents (for example, to achieve ophthalmic compatibility or to satisfy the regulatory requirements). A further significant advantage of the present methods and compositions is that the pigment is not deactivated during the crosslinking and / or polymerization step. It has been discovered in an unexpected manner that the pigments, particularly the metal phthalocyanine pigments and their equivalents, are not subject to a substantial dye deactivation during the application of ultraviolet radiation to form the solid contact lens. In contrast, a very large number of dyes are subject to bleaching during the polymerization step or molding of the lens manufacturing process. Moreover, the crosslinking can be carried out in an aqueous solution, so that the subsequent exchange of solvents or the hydration step, respectively, is not required. Finally, the photopolymerization takes place in a short time, in such a way that the process for the production of the contact lenses of the invention can be made extremely economical from that point of view as well. All the advantages mentioned above are applied in a natural way not only to contact lenses, but also to other articles molded according to the invention. Although visibly dyed ophthalmic lenses are the preferred products, the present invention may have utility in the manufacture of a wide variety of translucent or transparent polymeric products, including, without limitation, automotive windshields or translucent side glass; films or membranes such as diffusion control membranes, photo-resilient films for diffusion storage, or photoresist materials (e.g., membranes or molded articles for recording resistance or screen printing resistance); and plastic glasses. Ophthalmic lenses, as used herein, refer to contact lenses (hard or soft), intraocular lenses, eye bandages, and artificial corneas. The present invention has particular utility with respect to the manufacture of soft hydrophilic contact lenses that are dyed throughout the body, such that the consumer can identify the lenses in a container for storing the lenses. The sum of the various convenient aspects in the production of the molded articles of the invention, leads to molded articles of the invention suitable especially as mass-produced articles, for example as contact lenses that are worn for a short period of time, and then be replaced by new lenses. In the following examples, the amounts are amounts by weight, unless otherwise specified, and temperatures are given in degrees Celsius. The examples do not they are intended to limit the invention in any way, for example, within the scope of the examples.

EXAMPLE 1 (Preparation of the functionalizer of the polymer precursor) 220 grams of sodium hydroxide are dissolved in 300 grams of water and 700 grams of ice in a 3-liter reactor having a stirrer and a stirring system. The sodium hydroxide solution is cooled to 10 ° C. 526 grams of aminoacetaldehyde dimethylacetal and 50 milligrams of 4-hydroxy-2, 2,6,6,6-tetramethylpiperidine 1-oxide (a radical inhibitor) are added to the sodium hydroxide solution. 548.6 grams of methacrylic acid chloride are slowly added to the solution at 10 ° C over a period of 3.5 hours. The pH value slowly decreases to 7.2 when the addition is completed, and amine can no longer be detected by gas chromatography. The mixture is extracted with 500 milliliters of petroleum ether, and in order to remove the impurities, the aqueous phase is saturated with sodium chloride, and extracted three times with 500 milliliters of methyl tertiary butyl ether. The organic phase is dried with magnesium sulfate, filtered, and concentrated using a rotary evaporator. The resulting 882.2 grams of yellowish oil is slowly stirred in 2000 milliliters of petroleum ether at -10 ° C by means of an Ultraurax. The product is crystallized, and isolated by filtration and dried. 713.8 grams of methacrylamidoacetaldehyde dimethylacetal, which has a melting point of 30-32 ° C. The product is 99.7 percent pure according to gas chromatography.

EXAMPLE 2 (Preparation of the crosslinkable polymer precursor) 300 grams of Mowiol 3-83 (Hoechst polyvinyl alcohol) are placed in a 2-liter, double jacket reactor having a stirrer and a thermometer. 800 grams of deionized water are added to the reactor, and the aqueous mixture is heated to 95 ° C with stirring. After about 1 hour, a clear solution of polyvinyl alcohol is produced. The solution is cooled to 20 ° C. 27 grams of methacrylamidoacetaldehyde dimethylacetal functionalizer (from Example 1), 440 grams of acetic acid, 100 grams of concentrated hydrochloric acid (at 37 percent), and 333 grams of deionized water are mixed to produce a reaction solution "of 2000 grams The mixture is stirred for 20 hours at 20 ° C to produce a crosslinkable polyvinyl alcohol The change in the acetate content can be ascertained by titration with acetic acid.

EXAMPLE 3 (Purification of crosslinkable polymer precursor) The crosslinkable polyvinyl alcohol solution of Example 2 is dialyzed by ultraflibration. Ultrafiltration is performed using a 1-KD-Omega membrane produced per Filtron. Ultrafiltration is continued until a residual sodium chloride content of 0.004 percent is reached. The concentration of the dialysed solution produces 942 grams of a 30 percent crosslinkable polyvinyl alcohol solution, with an N content of 0.672 percent (by Kjeldahl determination), an acetate content of 1516 milliequivalents / gram (by hydrolysis). ), a dynamic viscosity of 2000 mPas, double bonds of 0.480 milliequivalents / gram (by microhydrogenation), free hydroxyl groups of 17.74 milliequivalents / gram (by reacetylation), molecular weights of Mw = 26200 and Mn = 12300 (by exclusion chromatography) of sizes in water). t? .. TRMPtr > ? (Preparation of a pigment dispersion) An aqueous dispersion is prepared by adding, with stirring, 0.97 grams of a purified copper phthalocyanine pigment (Unisphere Blue G-PI, average particle size of 433 nanometers) to a solution of 1.55 grams of Mowiol 3-83, and 3.97 milliliters of distilled water. 0.65 grams of the pigment dispersion obtained above are diluted by adding, with agitation, 205.0 grams of the crosslinkable polyvinyl alcohol solution according to Example 3. The pigment content of the resulting dispersion is 0.047 weight percent in relation to with all the dispersion.

EXAMPLE 5 (Preparation of a dyed prepolymerization mixture) 17.5 grams of the diluted pigment dispersion according to Example 4, are added to 191.5 grams of the purified solution of the polymer precursor according to Example 3. After the addition of approximately 0.2 grams of photoinitiator (Irgacure® 2959), the resulting formulation is mixed for about 1 hour, and then filtered on a 0.45 millimeter filter. The pigment content of the resulting tinted prepolymerization mixture is 39.6 ppm relative to the entire formulation.

EXAMPLE 6 (Formation of a dyed contact lens) Approximately 0.025 milliliters of the dyed prepolymerization mixture of Example 5 are dosed into a female mold half of a two-sided contact lens mold. The male mold half is then releasably attached to the female mold half. Ultraviolet radiation is applied at an intensity of approximately 2.5 m / cm2 for a period of approximately 14 seconds. The mold halves are separated and the lens is removed. The lens dyes uniformly throughout the body, and has a visible light transmission of approximately 96 percent.

Claims (18)

1. A process for the manufacture of a dyed ophthalmic molded article, which comprises the steps of: (a) providing a water soluble polymer precursor having crosslinkable or polymerizable groups; ~ (b) providing a pigment dispersion comprising an inorganic or organic pigment, and a dispersing agent; (c) mixing the pigment dispersion with the polymer precursor to form a dyed prepolymerization mixture, (d) dosing the dyed prepolymerization mixture in a mold, (e) applying radiation to the dye prepolymerization mixture in the mold, crosslinking or polymerizing in this way the polymer precursor, and trapping the pigment inside the polymer network of the resulting ophthalmic molded article, and (f) opening the mold, in such a way that the ophthalmic molded article can be removed from the mold.

2. A process according to claim 1, wherein the ophthalmic molded article is a contact lens.

3. A process according to claim 1 or 2, wherein the water soluble polymer precursor is a crosslinkable polyvinyl alcohol having a weight average molecular weight of at least 2,000.

A process according to any of claims 1 to 3, wherein the water soluble polymer precursor is a polyvinyl alcohol having a weight average molecular weight of at least about 2,000, based on the number of hydroxyl groups of polyvinyl alcohol, includes from about 0.5 percent to about 80 percent of units of formula I: CH, CH, CH CH I I O O CH: D wherein: R is alkylene having up to 8 carbon atoms, Ri is hydrogen or lower alkyl, and R 2 is an olefinically unsaturated, electron-withdrawing copolymerizable radical.

5. A process according to any of claims 1 to 4, wherein the polymer precursor Water-soluble is a polyvinyl alcohol having a weight average molecular weight of at least about 2,000 which, based on the number of polyvinyl alcohol hydroxyl groups, includes from about 0.5 percent to about 80 percent units of the polyvinyl alcohol. Formula III: CH, CH, CH CH (III) CH \ (C0NH- (R4NHCOO) q-R5-O) p-COR wherein R is alkylene having up to 8 carbon atoms, Ri is hydrogen or lower alkyl, p is zero or one, q is zero or one, R3 is an olefinically unsaturated copolymerizable radical having from 2 to 8 carbon atoms, and R and R5 are each, independently of the other, alkylene having from 2 to 8 carbon atoms, arylene having from 6 to 12 carbon atoms, a saturated divalent cycloaliphatic group having from 7 to 14 carbon atoms, or arylenenalkarylene which has 13 to 16 carbon atoms.

6. A process according to claim 4 or 5, wherein R is alkylene having up to 6 carbon atoms, p is zero, and R3 is alkenyl having from 2 to 8 carbon atoms.

7. A process according to any of claims 1 to 6, wherein the water soluble polymer precursor according to step (a) is provided in the form of an aqueous solution of 15 to 50 weight percent.

8. A process according to any of claims 1 to 7, wherein the pigment according to step "(b) is a phthalocyanine pigment 9. A process according to any of claims 1 to 8, in wherein the pigment dispersion according to step (b) is an aqueous dispersion comprising the pigment and a water-soluble polymer dispersion agent selected from the group consisting of a polymer precursor according to (a), a polyacrylic acid, and a non-crosslinkable polyvinyl alcohol 10. A process according to any of claims 1 to 9, wherein the dispersion of the pigment according to step (b) is an aqueous dispersion comprising a pigment of phthalocyanine and a water-soluble polymer dispersion agent selected from the group consisting of a polymer precursor according to (a) and a non-crosslinkable polyvinyl alcohol. in claims 1 to 10, wherein the weight percentage of the pigment, based on the total weight of the polymer precursor and the optional comonomers present in the prepolymer mixture, merization according to (c), is approximately 0.0001 to 0.05 percent. 12. A process according to any of claims 1 to 11, wherein a photoinitiator is added to the prepolymerization mixture according to step (c). 13. A process according to any of claims 1 to 12, wherein the mixture of prepolymerization. according to step (c) it does not have a comonomer. 14. A process according to any of claims 1 to 13, wherein the crosslinking and / or polymerization of the polymer precursor, and the entrapment of the pigment according to step (e), occurs in a period of =. 5 minutes . 15. A process according to claim 1, for the manufacture of a dyed contact lens, which comprises the following steps: (a) providing an aqueous solution of a polyvinyl alcohol having polymerizable or crosslinkable groups; (b) providing an aqueous dispersion comprising a copper phthalocyanine pigment; (c) mixing the polyvinyl alcohol solution with the pigment dispersion to form a dyed prepolymerization mixture; (d) introducing the dyed prepolymerization mixture into a mold; (e) applying radiation to the pre-polymerization mixture dyed in the mold, thereby crosslinking or polymerizing the polymer precursor, and trapping the pigment inside the polymer network of the resulting contact lens, and (f) opening the mold, such that the tinted contact lens can be removed from the mold. 16. A process according to claim 1, for the manufacture of a dyed contact lens, which comprises the following steps: (a) providing an aqueous solution of 15 to 40 weight percent of a polyvinyl alcohol prepolymer which have a weight average molecular weight of at least about 2000 which, based on the number of polyvinyl alcohol hydroxyl groups, includes from about 0.5 percent to about 80 percent of units of formula I: CH, CH, CH CH O (i) CH wherein R is alkylene having up to 8 carbon atoms carbon, R is hydrogen or lower alkyl, and R 2 is an olefinically unsaturated copolymerizable electron attracting radical; (b) providing an aqueous dispersion comprising a copper phthalocyanine pigment, and a dispersing agent selected from the group consisting of a polyvinyl alcohol prepolymer according to (a), a polyacrylic acid, and a polyvinyl alcohol not crosslinkable; (c) mixing the prepolymer solution according to (a) with the pigment dispersion according to (b) to form a dyed prepolymerization mixture; (d) introducing the dyed prepolymerization mixture into a mold; (e) applying radiation to the prepolymerization mixture in the mold, over a period of time of =. 5 minutes, by crosslinking or polymerizing the polymer precursor in this way, and trapping the pigment inside the polymer network of the resulting contact lens, and (f) opening the mold, so that the dyed contact lens of the polymer can be removed. mold. 17. A process according to claim 1, for the manufacture of a dyed contact lens, which is suitable for insertion into the human eye without extraction, which comprises the following steps: (a) provide an aqueous solution of the to 40 per weight percent of a polyvinyl alcohol prepolymer having a weight average molecular weight of at least about 2000 which, based on the number of polyvinyl alcohol hydroxyl groups, includes from about 0.5 percent to about 80 percent units of formula III: CH, CH, CH CH O O (III) CH R - N \ (CONH- (R4NHCO?) A-R5-0) -COR3 wherein R is alkylene having up to 6 carbon atoms, Ri is hydrogen or alkyl having up to 4 carbon atoms, p is zero, and R 3 is a-annyl which has from 2 to 8 carbon atoms; (b) providing an aqueous dispersion comprising a copper phthalocyanine pigment, and a dispersing agent selected from the group consisting of a polyvinyl alcohol prepolymer according to (a) and a non-crosslinkable polyvinyl alcohol; (c) mixing the prepolymer solution according to (a) with the pigment dispersion according to (b), and an additional photoinitiator to form a prepolymerization mixture. dyed containing from 0.0001 to 0.05 weight percent phthalocyanine pigment, based on the total weight of the polymer precursor; (d) introducing the dyed prepolymerization mixture into a mold; (e) applying radiation to the prepolymerization mixture stained in the mold, over a period of time of =. 1 minute, thereby crosslinking or polymerizing the polymer precursor, and trapping the pigment inside the polymer network of the resulting contact lens, and (f) opening the polder, so that the dyed contact lens of the polymer can be removed. mold. 18. An ophthalmic molded article which is formed by a process according to any of claims 1 to 17.