MXPA00002163A - Process for the manufacture of a molding - Google Patents

Abstract

The present invention relates to a process for the manufacture of a molding, which comprises the following steps:a) providing at least one prepolymer comprising one or more crosslinkable groups, wherein the prepolymer is an amphiphilic segmentedcopolymer comprising at least one hydrophobic segment A and one hydrophilic segment B;b) preparing a mesophase of the prepolymer which is at least partly bicontinuous;c) introducing the mesophase obtained into an ophthalmic mold;d) triggering of the crosslinking;and e) opening the mold such that the molding can be removed. The process of the invention is particularly suited for the manufacture of membranes and ophthalmic moldings such as contact lenses.

Description

ROf-Tügn PAPA T.A _n_tratrAr_tor. nt_? M &pttrttt. Mr.t.mg & nr > This invention relates broadly to a novel process for the manufacture of molded articles, such as biomedical devices, membranes, and particularly to molded articles useful in optic and ophthalmic techniques. More specifically, the invention relates to a novel process for the manufacture of contact lenses, wherein a crosslinkable amphiphilic prepolymer is first converted into a discontinuous mesophase which is then crosslinked. The publication of the TCP Number WO 96/31792 discloses ophthalmic molded articles, such as contact lenses for prolonged use, comprising bicontinuous phases, for example, an oxygen permeable phase allowing permeation of oxygen, and a phase permeable to ions that allows the permeation of water or ions. Ophthalmic molded articles are prepared, for example, by crosslinking a crosslinkable prepolymer which is an amphiphilic block copolymer having hydrophobic oxygen permeable segments and hydrophilic segments permeable to ions, because the known prepolymers are insoluble In water for the most part, the crosslinking is usually carried out in an organic solvent, such as chloroform or the like, According to the above, the resulting molded article must be removed later in order to remove the solvent, and in addition to hydrate in order to obtain, for example, a contact lens that is ready to be used The known process for the crosslinking of water-insoluble segmented amphiphilic copolymers, which includes an extraction and hydration step, is therefore very slow, and therefore, is not suitable for the economic manufacture of a large number of molded articles os, such as contact lenses, in a short time. According to the above, there is a demand for a more simplified process for the manufacture of these ophthalmic molded articles, which particularly omits an extraction and / or hydration step. Surprisingly, it has now been discovered that a molded article having a microstructure can be obtained at least partially bicontinuously by first converting a suitable amphiphilic segmented copolymer having crosslinkable groups first into a mesophase at least partially bicontinuous, and then The obtained mesophase is reticulated. Accordingly, the present invention relates to a process for manufacturing a molded article, which comprises the following steps: a) providing at least one prepolymer comprising one or more crosslinkable groups, wherein the prepolymer is a segmented amphiphilic copolymer comprising at least one hydrophobic segment A and one hydrophilic segment B; b) prepare one. at least partially bicontinuous mesophase of the prepolymer; c) enter the mesophase obtained in a mold; d) unleash the crosslinking; and e) opening the mold, in such a way that the molded article can be removed. It has been asserted, according to the invention, that the process can be applied in general to segmented amphiphilic copolymers having the above properties. The decisive criteria determining the property of a prepolymer to be used in the process according to the invention are: (i) that the prepolymer forms an optically transparent bicontinuous mesophase in the melt or in the presence of an aqueous solution, and (ii) ) that includes crosslinkable groups. The term "mesophase" in this context, should be understood to mean a thermodynamically stable mixture of an amphiphilic substance, such as a above-mentioned crosslinkable amphiphilic substance, and an aqueous solution or a fusion of the above-mentioned crosslinkable amphiphilic block copolymer, which shows in each case a self-assembled microstructure. Mesophases are typically homogeneous and optically transparent mixtures that are in single-phase regions of the phase diagram of the components on which the system is based. These simple phases may be of a liquid crystalline nature (such as lamellar, hexagonal, or cubic), which indicates an ordered division of compartments of the components in the mixture, with a geometrically regular and repeated structure, or it can be of a non-crystalline nature, where the division of compartments is random and isotropic An example of this last type of mesophases is represented by microemulsions. According to the above, many microstructures can be presented within the general class of mesophases. Within the present invention, mesophases having a liquid crystalline microstructure are preferred. The mesophases of the claimed process, therefore, are preferably in the single phase regions of the phase diagram exhibiting a crystal structure, and more preferably a cubic structure. In addition, the mesophases of the present invention are at least partially bicontinuous, that is, the mixture has at least two partially bicontinuous phases, for example, an oxygen permeable phase, and an ion permeable phase, which are interlaced. A "phase", as used herein, refers to a region of a substantially uniform composition, which is a distinct and physically separate portion of a heterogeneous polymeric material. However, the term "phase" does not imply that the material described is a chemically pure substance, but merely that certain properties in volume differ in a significant way from the properties of another phase within the material. Accordingly, with respect to the polymeric components of an ophthalmic molded article, such as a lens, an ion-permeable phase refers to a region composed of essentially only ion-permeable polymer (and water, when hydrated), while that an oxygen permeable phase refers to a region composed essentially of only oxygen permeable polymer (and perhaps a small amount of water, when hydrated). The "bicontinuous phases", as used herein, refer to at least two regions, each of a substantially uniform composition that differs from the other, and each of which exhibits its individual properties. With respect to ophthalmic molded articles, such as contact lenses, it has been found that it is highly desirable to have bicontinuous phases of an oxygen permeable polymer and an ion permeable polymer, which provide the lens with two continuous paths or sets of continuous trajectories that extend from the inner surface of the lens to the outer surface of the lens. These at least two continuous paths ensure that the lens material has both high oxygen transmissibility and permeability to ions or water. "Crosslinkable groups" denotes customary crosslinkable groups well known to the person skilled in the art, such as, for example, photocrosslinkable 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 (Opening Metathesis Polymerization) of Ring), vulcanization, cationic crosslinking, epoxy hardening, and reduction-oxidation reaction. The segmented amphiphilic copolymers of the invention comprise at least one hydrophobic segment A, which preferably comprises an oxygen permeable polymer as exemplified below, ie, a polymer exhibiting a relatively high oxygen diffusion rate therethrough. . In addition, the materials of this embodiment of the invention must be ophthalmically compatible. Suitable hydrophobic segments A which may comprise the prepolymers are, for example, polysiloxanes; perfluoro-polyalkyl ethers; specific unsaturated polymers, for example, a polymer of an aliphatic or conjugated alicyclic diene, a polymer of an alkyne or dialkyne, a copolymer of a conjugated diene and a hydrophilic or hydrophobic vinyl monomer, and also partially hydrated derivatives thereof; or poly-sulfones. Preferred hydrophobic segments A comprise perfluoropolyalkyl ethers, or particularly polysiloxanes. According to one embodiment of the invention, the oxygen permeable polymer in segment A comprises a polysiloxane block having terminal alkylene groups of the formula I: where n is an integer from 5 to 700; Alk is alkylene having up to 20 carbon atoms; from 80 to 100 percent of the radicals Ri, R2, R3, and R4. independently of one another, they are alkyl, and from 0 to 20 percent of the radicals Ri, R2, R3, and R4, independently of one another, are alkenyl, aryl, fluoroalkyl, or cyanoalkyl. In a preferred meaning, n is an integer from 10 to 500, more preferably from 10 to 300, and particularly preferably from 20 to 120, and in particular from 20 to 80. In a preferred sense, from 80 to 100 by percent, preferably from 85 to 100 percent, in particular from 90 to 100 percent of the radicals Ri, R2, R3, and R4, independently of each other, are lower alkyl having up to 8 carbon atoms, in a manner particularly preferably lower alkyl having up to 4 carbon atoms, especially lower alkyl having up to 2 carbon atoms. A further particularly preferred meaning of Ri, R2, R3, and R4 is methyl. In a preferred meaning, 0 to 20 percent, preferably from 0 to 15 percent, in particular from 0 to 10 percent of Ri, R2, R3 and R4 radicals, independently of one another, they are lower alkenyl, phenyl unsubstituted or substituted by lower alkyl or lower alkoxy, fluoro (lower alkyl), for example trifluoropropyl or cyano (lower alkyl). According to another embodiment of the invention, the oxygen permeable polymer in segment A comprises a perfluoroalkyl-polyether block of formula II: - (E) kZ-CF2- (OCF2) x- (OCF2CF2) and -OCF2- Z- (E) k (II) where x + y is a number on the scale from 10 to 100; each Z, independently of the others, is a divalent radical having up to 12 carbon atoms, or a bond; each E, independently of the others, is alkoxy for example - (OCH2CH2) q-where q has a value of 0 to 2, as a statistical average, and where the -ZE- bond represents the sequence -Z- (OCH2CH2 ) q-; and is 0 or 1. Z is preferably a bond, lower alkylene, or -CONH-arylene, wherein the -CO- moiety is linked to a CF2 group. Z is particularly preferably lower alkylene, in particular methylene. The perfluoroalkoxyl units OCF2 and OCF2CF2, which have the indices x and y in the formula (II), can have a random distribution. The sum of the indices x + y is preferably a number on the scale of 10 to 50, in a particularly preferable way of 10 to 30. The ratio x: y is preferably on the scale of 0.5 to 1.5, particularly in the scale from 0.8 to 1.2. In another embodiment of the invention, the oxygen permeable polymer in segment A comprises an unsaturated polymer, for example a polymer of an aliphatic or conjugated alicyclic diene, which may be substituted by halogen or lower alkyl, a polymer of an alkyne or dialquino, which may be substituted by lower alkyl or trimethylsilyl, a copolymer of a conjugated diene and one hydrophilic or hydrophobic vinylic monomer, or a partially hydrated derivative of said compounds. Specific examples of the preferred unsaturated polymers are cis-, trans-, iso-, or poly-1,2-butadiene sindio-tactic, poly-1,4-butadiene, or polyisoprene; poly-pentenamer; polychloroprene; polypropylene; copolymers of butadiene or isoprene with hydrophilic or hydrophobic vinyl monomers, such as acrylonitrile, styrene, acrylic acid, or hydroxyethyl methacrylate; or poly-1-trimethylsilyl-propyne. An especially preferred unsaturated polymer is selected from poly-syndiotactic 1,2-butadiene, poly-1,4-butadiene, and polyisoprene. An especially preferred unsaturated polymer is poly-1-trimethylsilyl-propyne. Another especially preferred unsaturated polymer is poly-1,4-butadiene. In a further embodiment of the invention, the oxygen permeable polymer in segment A comprises a polysulfone comprising at least one of the structural elements Illa) to Illd): -R-S02- Illa) CH3 I 3 -R-C-R-O-R-SO, -R- I 2 Illb) CH3 -R-S02-R-0-IIIc) -R-0-R-S02-R-R-S02-Illd) wherein R in the structural element Illa) is alkylene or arylene, and R in the structural elements Illb), lile), and Illd) is arylene, especially phenylene. In one embodiment of the invention, the oxygen permeable polymer in segment A may comprise one of the polymers illustrated above. According to another embodiment, the oxygen permeable polymer in segment A may comprise more than one class of polymers as illustrated above, for example, it may comprise perfluoroalkylene polyether or polybutadiene subsegments (a) and subsegments of polybutadiene. Lysiloxane (b).

A preferred embodiment of the invention relates to prepolymers, particularly to prepolymers for ophthalmic uses, wherein the segments A have an average molecular weight, for example, in the range of about 1,000 to 50,000, of preference in the scale of about 1,500 to about 30,000, and in a particularly preferable manner, in the range of about 2,000 to about 20,000. Suitable hydrophilic segments B are, for example: (i) nonionic segments, for example a polyoxyalkylene, polysaccharide, polypeptide, poly (vinylpyrrolidone), polyalkyl acrylate or methacrylate, polyhydroxyalkyl acrylate or methacrylate, polyacylalkyleneimine, polyacrylamide, polyvinyl alcohol, polyvinyl ether, or polyol, (ii) polyionic segments, for example a polycationic segment such as a polyallylammonium, polyethyleneimine, polyvinylbenzyltrimethylammonium, polyaniline, sulfonated polyaniline, polypyrrole, or a polypyridinium segment, or a polya-nionic segment , such as a polyacrylic or polymethacrylic acid, a polythiophenacetic acid, a polystyrenesulfonic acid, or a suitable salt thereof. Some examples of the preferred hydrophilic segments B are a polyethylene glycol, polypropylene glycol, poly (vinylpyrrolidone), poly (methyl methacrylate), poly (hydroxyethyl acrylate), poly (hydroxyethyl methacrylate), polyacrylamide, poly (N, N) dimethylacrylamide), polyacrylic or polymethacrylic acid, or a copolymer mixture of 2 or more of the aforementioned polymers, or a segment of polyacylalkylaminimine derivable from a cyclic imino ether of the formula (IV): wherein R9 represents a hydrogen atom, an alkyl, hydroxyalkyl, or alkenyl group having up to 22 carbon atoms, and optionally containing ether, ester, or urethane groups, a cycloalkyl group, an aralkyl group, or an aryl group; and t is 2 or 3. Suitable cyclic imino ethers are, for example, 2-methyl-2-oxazoline, a 2-alkenyloxazoline, a 2- (hydroxyalkyl) oxazoline, or a 2-isocyanatoethyl methacrylate thereof. The weight average molecular weight of the hydrophilic blocks B can vary within wide limits. A preferred embodiment of the invention relates to prepolymers, particularly to prepolymers for ophthalmic uses, wherein segments B have a scale average molecular weight of about 200 to about 10,000, preferably in the range of about 350 to about 5,000, and in a particularly preferable manner on the scale of about 500 to about 1,500.

Segments A and B can be linked by a direct link, which is preferably a non-hydrolysable link, by I I I I I example a link • C-C-. -C-Si- C-N-C-, -C-O-C- l i l i or they can be linked through a bridge member. A suitable bridge member is, for example, a functional group of carbonyl, carbonate, ester, amide, urea, or urethane or is, for example, an alkylene, cycloalkylene, aralkylene, arylene, or heterocyclic group containing one or more, preferably two of the mentioned functional groups. The starting segments A and / or B forming the copolymers of the invention, may already contain crosslinkable groups, and these crosslinkable groups may be introduced during, or preferably after, the formation of the copolymers, for example by reaction of reactive groups on the polymer, such as amino, hydroxyl, or the like groups , with unsaturated compounds that are coreactive with these reactive groups. Examples of these co-reactive unsaturated compounds are, for example, acrylic acid, methacrylic acid, meta-cryloyl chloride, hydroxyethyl methacrylate (HEMA), 2-vinyl-4,4-dimethyl-azlactone, 2-isocyanatoethyl acrylate or methacrylate ( IEM), allyl isocyanate, vinyl isocyanate, isomeric vinylbenzyl isocyanates or adducts of hydroxyethyl methacrylate and 2,4-tolylene di-isocyanate (TDI) or di-isophorone (IPDI), in particular the adduct 1 :1. The crosslinkable fractions can be attached to segments A and / or B, and preferably to segments B. The structure of the prepolymers of the invention can vary within wide limits. Accordingly, they may consist of one embodiment of a segment A and one segment B only (AB diblock copolymers), or of a segment A and two B segments joined with their terms (triblock copolymers BAB), or may have a structure of type of comb, wherein several segments B hang from a segment A (which, of course, can also carry one or two terminal B segments, comb block copolymers A (-B) r), where A and B have the meaning given above, r is >; 2, and wherein A and B may be linked by a direct link, or by a previously mentioned bridging member, and some or all of the segments A, or preferably B, carry a crosslinkable group, in particular a crosslinkable CC double bond . In another embodiment, the segmented amphiphilic copolymers of the invention may consist of a segment B and two segments A joined with their terms (triblock of type ABA) or may have a comb-like structure, wherein several A segments hang from a segment B (which of course can also carry one or two segments A terminals, comb block copolymers B (-A) r). Some examples of the preferred prepolymer materials suitable for the process of the invention are segmented amphiphilic copolymers as disclosed in PCT Application No. WO 97/49740, or Materials "A" and "C" given to know in the TCP Application Number WO 96/31792. The respective portion of these two documents, including the formulas, definitions, and preferences given therein, is incorporated herein by reference. A group of preferred prepolymers are those in which segments A and B are linked by a non-hydrolysable group. According to a preferred process, these prepolymers are formed by the polymerization of a suitable hydrophilic monomer (which provides segment B), for example a cyclic imino-ether, such as 2-methyloxazoline, a vinyl ether, a cyclic ether, including epoxides, a cyclic unsaturated ether, an N-substituted aziridine, β-lactone, β-lactam, ketenacetal, vinyl acetal, or phosphorane, in the presence of a suitably functionalized segment A, for example one of the aforementioned segments A , such that a block of hydrophilic monomer units grows from the site of the functionalization of segment A. The segmented copolymers obtained by grafting suitable hydrophilic monomers onto a starting segment A, may already contain polymerizable unsaturated groups in the hydrophobic and / or hydrophilic segments, for example, if a hydrophobic segment A comprises a diene polymer such as polybutadiene or polyisoprene, or if the monomer used to make a hydrophilic segment comprises an unsaturated side chain, for example 2-allyl-oxazoline. If there are no polymerizable unsaturated groups present, or also, if these groups are present, it is possible to introduce polymerizable unsaturated groups by suitable reactions, for example at the end of, or also pending, the growth of the segments. For this purpose, the graft polymerization of the growing segment can be terminated after a suitable chain length is reached, and the initiator group present at the end of the chain is capped, for example, using specific reagents such as hydroxystyrene, allyl alcohol, hydroxyethyl methacrylate, propargyl alcohol, allylamines and pro-pargylamine, or using KOH / EtOH or OH or -NHR * groups of primary or secondary amines, or unsaturated groups at the end of the growing segment, in where R * is, for example, hydrogen, alkyl, or aryl. Hydroxyl groups can also be introduced into the copolymers using suitable comonomers in the graft copolymerization, for example, 2-hydroxy-alkyl-oxazolines. The hydroxyl groups or -NHR * can then be reacted, for example, with an isocyanate carrying a polymerizable unsaturated group. Preferred examples of these bifunctional compounds are 2-isocyanatoethyl methacrylate (IEM), which is especially preferred, and vinyl isocyanate, allyl isocyanate, acryloyl isocyanate, styrene isocyanate, vinylbenzyl isocyanate, propargyl isocyanate, and anhydride (meth) acrylic. A particularly preferred example of this embodiment of the invention is the prepolymer shown on page 22 of Publication Number WO 97/49740. According to a further embodiment of the invention, a segmented amphiphilic copolymer having the segments A and B linked together through a bridge member in the process of the invention is employed. These copolymers include, for example, a dib, trib copolymer, or comb b AB, BAB or A (-B) r mentioned above, wherein the segments A and B are connected, for example, by means of a functional group of carbonyl, carbonate, ester, amide, urea, or urethane, or particularly by a bridging member -XR * -X-, wherein X is a functional group mentioned above, and R * is, for example, a group aliphatic, cycloaliphatic, aromatic, or divalent araliphatic having up to 20 carbon atoms, for example alkylene of 6 to 10 carbon atoms straight or branched; cyclohexylene-methylene, or cyclohexylene-methylene-cyclohexylene, which are each unsubstituted or substituted by 1 to 3 methyl groups; or phenylene unsubstituted or substituted by methyl, or phenylene-methylene-phenylene. A particularly preferred bridging member is of the formula -NH-C (O) -NH-R * -NH-C (O) -NH- or -0-C (0) -NH-R * -NH-C (O ) -0-, where R * is each as previously defined.

An example of the prepolymer of the latter type is a segmented amphiphilic copolymer of the formula: CP-PAO-DU-ALK-PDMS-ALK-DU-PAO-CP (V) wherein PDMS is a divalent polysiloxane, for example a polysiloxane of the formula (I) above; CP is an isocyanatoalkyl acrylate or methacrylate, preferably isocyanatoethyl methacrylate, wherein the urethane group is linked to the terminal atom on the PAC-PAO group is a divalent polyoxyalkylene, (which may be substituted), and is preferably a polyethylene oxide, i.e., (-CH2-CH2-0-) rCH2CH2-, wherein ml may be from about 3 to about 44, more preferably from about 4 to about 24; DU is a diurethane, which preferably includes a cyclic structure, for example a divalent radical which is derived from isophorone diisocyanate or toluene di-isocyanate, wherein an oxygen from the urethane linkage (1) is bonded to the PAO group, and an oxygen of the urethane linkage (2) is bonded to the ALK group; and ALK is an alkylene or oxyalkylene group having at least 3 carbon atoms, preferably a branched alkylene group or an oxyalkylene group having from 3 to 6 carbon atoms, and more preferably a secondary butyl group (i.e., -CH2CH2CH (CH3) -), or an ethoxypropoxyl group (for example -O- (CHa) 2-0- (CHa) 3-) • The prepolymers according to this embodiment of the invention can be prepared by processes known per se, for example, according to the processes disclosed in the Publication of TCP Number or WO 96/31792. Another example of a suitable prepolymer is a segmented amphiphilic copolymer comprising at least one segment of the formula (VI): wherein: * (a) is a polysiloxane segment, for example a segment of the aforementioned formula (I), (b) is a polyol segment containing at least 4 carbon atoms, Zx is a segment X2-R '-X2 or a group X1 t R' is a divalent radical of an organic compound having up to 20 carbon atoms, for example alkylene, arylene, alkylenearylene, or arylenealkylene having up to 14 carbon atoms, or a saturated divalent cycloaliphatic group having from 6 to 14 carbon atoms, and preferably alkylene or arylene having up to 12 carbon atoms, or a saturated divalent cycloaliphatic group having from 6 to 14 carbon atoms; each X2, independently of the other, is a divalent radical containing at least one carbonyl group, and is preferably an ester, amide, urethane, or urea group, and in particular an amide, urethane, or urea group; Xi is a divalent radical containing at least one carbonyl group, and is preferably an ester, amide, urethane, or urea group, in particular an ester or amide group, and d) is a radical of the formula (VII): wherein : Pi is a group that can be polymerized by free radicals, for example alkenyl or alkenylaryl having up to 12 carbon atoms, more preferably alkenyl having up to 8 carbon atoms, and in particular alkenyl having up to 4 carbon atoms; and 3 independently from each other, are a divalent radical containing at least one carbonyl group; Y being preferably a carbonyl, ester, amide, or urethane group, and X3 being preferably a urethane, urea, ester, amide, or carbonate group, more preferably a urethane, urea, ester, or amide group, and in particular a urethane or urea group, kl is 0 or 1; and L is a bond or a divalent radical having up to 20 carbon atoms of an organic compound, for example alkylene or arylene having up to 12 carbon atoms, and preferably alkylene having up to 4 carbon atoms.

If Zi in formula (VI) is Xi, it is preferably understood that a segment of polyol b means a polyol derived from a carbohydrate, a carbohydrate monolactone, or a carbohydrate dilactone. It is understood that a carbohydrate means a mono-, di-, tri-, tetra-, oligo-, or poly-saccharide. It is understood that a carbohydrate lactone means the lactone of an aldonic or uronic acid. An aldonic or uronic acid is, for example, a carboxylic acid formed by the oxidation of a mono-, di-, tri-, tetra-, oligo-, or poly-saccharide. Examples of the aldonic acid lactones are gluconolactone, galactonolactone, lactobionolactone, or maltoheptanolactone; examples of the uronic acid lactones are glucuronic acid lactone, mannuronic acid lactone, or iduronic acid lactone. An example of a carbohydrate dilactone is D-glucaro-1,4: 6, 3-dilactone. A polyol segment (b) is preferably derived from a polyol bearing no lactone group if the group Zi is a group X2-R'-X2. Examples of these polyols are 1,2-polyol, for example the reduced monosaccharides, for example mannitol, glucitol, sorbitol, or iditol; a 1,3-polyol, for example polyvinyl alcohol (PVA), which is derived from partially or completely hydrolyzed polyvinyl acetate, and furthermore amino-terminal polyvinyl alcohol telomers, aminopolyols, aminocyclodextrins, aminomono-, -di -, -tri-, -oligo-, or -poly-saccharides or cyclodextrin derivatives, for example hydroxypropyl-p-cyclodextrin. A above-mentioned carbohydrate dilactone can be reacted, for example, preferably with 2 equivalents of an amino-terminal polyvinyl alcohol telomer, to give a polyol macromer bearing, in the middle part, the carbohydrate compound derived from the dilactone. It is understood in the same way that the polyols of this composition are a suitable polyol. As illustrated in formula (VI), a segment (b) carries at least one polymerizable vinyl segment (d), a linkage of a segment (d) by means of the divalent radical X3 thereof with an amino or hydroxyl group, a segment (b), pretending that it is reduced by a hydrogen atom. A polymerizable vinyl segment (d) is incorporated either terminally or by hanging preferably from 1 to 20 times, more preferably from 2 to 15 times, and in particular from 2 to 6 times, per macromer molecule according to the invention. A polymerizable vinyl segment (d) is derived, for example, from acrylic acid, methacrylic acid, methacryloyl chloride, 2-isocyanatoethyl methacrylate (IEM), allyl isocyanate, vinyl isocyanate, isomeric vinylbenzyl isocyanates or adducts of hydroxyethyl methacrylate (HEMA), and 2,4-tolylene di-isocyanate (TDI) or isophorone di-isocyanate (IPDI), in particular the 1: 1 adduct. The proportion of the number of segments (a) and (b) in a macromer according to the formula (VI), preferably is in the scale of (a) :( b) = 3: 4, 2: 3, 1: 2, 1: 1, 1: 3 or 1: 4. The total sum of the segments (a) and (b) is in the scale from 2 to 50, preferably from 3 to 30, and in particular in the scale from 3 to 12. The prepolymers according to the formula (VI) they can be prepared by processes known per se, for example, according to the processes disclosed in the PCT Publication Number WO 96/31792. The molecular weight of the prepolymer employed in the process of the invention, within wide limits, is not critical. However, preferably, the prepolymer has a weight average molecular weight of from about 500 to 200,000, preferably from 800 to 100,000, and more preferably from 1,000 to 50,000, and most preferably from 3,000 to 25,000. The prepolymer is preferably introduced into the process of the invention in a pure form, in a particular manner substantially free of undesired constituents, such as, for example, free from monomeric, oligomeric, or polymeric starting materials used for the preparation of the prepolymer. -ro, and / or free of secondary products formed during the preparation of the prepolymer. These prepolymers in pure form are conveniently obtained by previously purifying them in a manner known per se, for example by precipitation with a suitable solvent, filtration and washing, extraction in a suitable solvent, dialysis, reverse osmosis (RO) or ultrafiltration, with preference being given to especially reverse osmosis and ultra-filtration. The preferred purification processes for the prepolymers of the invention, reverse osmosis and ultrafiltration, can be carried out in a manner known per se. It is possible that ultrafiltration and reverse osmosis are performed repeatedly, for example, 2 to 10 times. Alternatively, ultrafiltration and reverse osmosis can be performed continuously until the selected degree of purity is obtained. The degree of purity selected, in principle, can be as high as desired.

Preparation of a mesophase at least partially bicontinuous According to the process of the invention, the aforementioned prepolymers are converted into a mesophase which is at least partially bicontinuous. The mesophases can be prepared from a fusion of one or more different prepolymers having the aforementioned characteristics, and optionally other components, or preferably, from one or more different prepolymers, an aqueous solution, and optionally other components. (1) aqueous solution: The aqueous solution that is added to form the mesophase can be pure water or a mixture of water and one or more miscible solvents in water and / or salts. (i) organic solvents miscible in water: Examples of suitable solvents that can be added to the mesophase are a monohydric or polyhydric alcohol, for example an alcohol of 1 to 8 carbon atoms such as normal butanol, normal propanol , ethanol, or methanol, or a polyhydric alcohol, such as glycerol or a glycol; a polyether, such as Bu-tyl Cellosolve ", Butyl Carbitol" *, Hexyl Cellosolve ", or Hexyl Carbitol" 1 *; a carboxylic acid amide, for example N, N-dimethylformamide; acetone, acetonitrile; dimethyl sulfoxide; or mixtures thereof. Preferably, the aqueous solution does not comprise an additional organic solvent, or comprises an alcohol of 1 to 4 carbon atoms, for example ethanol or methanol as additional organic solvent. In a particularly preferred embodiment of the invention, the aqueous solution does not comprise an additional organic solvent. (ii) salts: Salts which may be comprised in the aqueous solution used to form the mesophases of the invention, include, without limitation, 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 alkali halides, for example sodium chloride, or mixtures thereof. If salts are added, the aqueous salt solution has, for example, an osmolarity of about 200 to 450 milliosmoles in 1,000 milliliters (unit: mOsm / 1), preferably an osmolarity of about 250 to 350 milliosmoles / liter, and in particular approximately 300 milliosmoles / liter. An example of a particularly suitable aqueous salt solution of the invention is an artificial tear fluid, preferably of regulated pH, which, with respect to the pH value and osmolarity, is adapted to the natural tear fluid, for example a solution of sodium chloride that does not have the pH regulated, or that preferably has the pH regulated, for example, by a phosphate regulator, and that has an osmolarity that corresponds to the osmolarity of the human tear fluid. The aqueous solution used for the formation of the meso-phases of the invention is preferably a pure solution, which means a solution that is free or essentially free of undesired constituents. Especially preferred examples of these solutions are pure water or artificial tear fluid, as defined hereinabove. (2) other optional components: Other optional components that are used for the preparation of the mesophases of the invention, in addition to the crosslinkable amphiphilic block copolymer and the aqueous solution, are, for example: (i) photoinitiators: In the case of photocrosslinking of the mesophases of the present invention, it is preferred to add a photoinitiator that can initiate radical crosslinking. The examples thereof are familiar to the person skilled in the art. Useful photoinitiators include, for example, benzophenones substituted with an ionic moiety, a hydrophilic moiety, or both, such as 4-trimethylaminomethyl-benzophenone hydrochloride, or benzophenone sodium 4-methanesulfonate; 1 to 4 carbon atoms alkyl benzoin, such as benzoin methylether; thioxanthones substituted with an ionic fraction, a hydrophilic fraction, or both, such as 3- (2-hydroxy-3-trimethylaminopropoxy) thioxanthone hydrochloride, 3- (3-trimethylaminopropoxy) thioxanthone hydrochloride, sodium salt of 3- (2-hydroxy-3-trimethylaminopropoxy) thioxanthone -ethoxysulfonic acid) of thioxanthone, or the sodium salt of 3- (3-propoxysulfonic acid) of thioxanthone; or phenylketones, such as 1-hydroxycyclohexylphenyl-ketone, (2-hydroxy-2-propyl) (4-diethylene glycol-phenyl) ketone, (2-hydroxy-2-propyl) (4-butanecarbo-phenyl xylate) ketone; or commercial products such as the Darocure types "8 or IrgacureM for example, Darocure 1173 or Irgacu-re 2959.

The photoinitiator, if added to the mesophases of the invention, is present in an amount, for example, from 0.05 to about 1.5 weight percent, preferably from 0.1 to 1.0 weight percent, and in a particularly preferable manner from 0.08 to 0.5 percent by weight, based on the prepolymer content in each case. (ii) thermal initiators: In the case of thermally inducing the cross-linking of the mesophases of the present invention, it is preferred to add a thermal initiator which, upon exposure to heat, can initiate radical cross-linking. The examples thereof are familiar to the person skilled in the art. Useful thermal initiators include, without limitation, azodiisobutyronitrile, persulphates such as potassium persulfate, ammonium persulfate, sodium persulfate, or mixtures thereof. (iii) reduction-oxidation initiators: In the case of inducing cross-linking of the mesophases electrochemically, it is preferred to add a reduction-oxidation initiator to the mixture that forms the mesophase. The examples thereof are familiar to the person skilled in the art, and include, for example, TiCl3, RhCl3, H202 / Fe2 + or diacyl peroxide / Cu +. (iv) surfactants: The mesophases can comprise an additional surfactant, preferably a non-polymerizable surfactant which is, for example, a nonionic, anionic, cationic, or suite-ionic surfactant. Examples of suitable nonionic surfactants are a condensation product of a higher aliphatic alcohol and ethylene oxide, for example a condensation product of a fatty alcohol of 8 to 20 carbon atoms, and from about 3 to 100 moles, of preferably from 5 to 40 moles, and more preferably from 5 to 20 moles of ethylene oxide (for example, the surfactants Tergitol "1 * 15-S from Union Carbide, the surfactants grj_jMR ^ e) condensates of polyethylene oxide from a mol of alkylphenol, for example an alkylphenol of 6 to 12 carbon atoms, and approximately 3 to 100 moles, preferably 5 to 40 moles, and most preferably 5 to 20 moles of ethylene oxide (for example, the Igepal surfactants "1 * CO or CA of Rhone-Poulenc, which are nonylphenoxypoly (ethyleneoxy) ethanols or octylpheno-xipoly (ethyleneoxy) ethanols); block copolymers of ethylene oxide and propylene oxide and / or butylene oxide (for example, the surfactants Pluronic "11 or Tetronic" 11 from BASF); or fatty acid esters, such as esters of sorbitan or stearic acid and a fatty alcohol or polyethylene oxide (for example, the surfactants SpanMR, T eenffi or Myrj "of ICI) Examples of suitable anionic surfactants they are alkyl or alkylaryl sulfates or sulfonates, for example alkyl sulfates of 6 to 20 carbon atoms or alkylaryl sulfates, such as sodium lauryl sulfate or sodium dodecylbenzenesulfonate, or polyoxyethylenealkyl (of approximately 6 to 20 carbon atoms) - or alkylphenoxypoly (ethyleneoxy) - o-esters and diesters of phosphoric acid and their salts with the repeating unit of ethylene oxide in the surfactant preferably below about 30 units, and more preferably below 20. Examples of suitable cationic surfactants are quaternary ammonium salts, where at least one group of higher molecular weight, or two or three groups of lower molecular weight are bound with a common nitrogen atom to produce a cation, and wherein the electrical equilibrium anion is, for example, a halide, acetate, nitrite, or lower alkyl sulfate (e.g., methyl sulfate). A higher molecular weight substituent on nitrogen is, for example, a higher alkyl group containing about 10 to 20 carbon atoms, and a lower molecular weight substituent may be lower alkyl of about 1 to 4 carbon atoms , such as methyl or ethyl which may be substituted, for example, by hydroxyl. One or more of the substituents may include an aryl fraction, or they can be replaced by aryl or alkyl, such as benzyl or phenyl. Among the possible lower molecular weight substituents are also lower alkyl of about 1 to 4 carbon atoms substituted by lower polyalkoxy moieties, such as polyoxyethylene moieties bearing a hydroxyl group, falling within the general formula -R2o (CH2CH2 -0) c-? CH2CH2OH wherein R2o is an alkylene group of 1 to 4 divalent carbon atoms bonded with nitrogen, and c represents an integer of about 1 to about 15. Alternatively, one or two of these fractions of lower polyalkoxy, which have terminal hydroxyls, can be directly linked to the quaternary nitrogen, instead of being linked thereto through the aforementioned lower alkyl. Examples of the quaternary ammonium salts are methylbis (2-hydroxyethyl) coco-ammonium chloride, oleylammonium chloride, or methylpolyoxyethylen (15) octadecylammonium chloride (for example, the Ethoquad surfactants of Akzo). An additional group of suitable cationic surfactants has the formula: R * ¡+ R¿¡- R ^ An where R2? and R22, which may be the same or different, are alkyl groups of 1 to 4 carbon atoms, preferably methyl or ethyl groups; R23 and R24, which may be the same or different, are groups of 1 to 30 carbon atoms; and An ~ is an appropriate counter-ion, for example, a halide; with the proviso that at least one of R2i, R22, and R23 and R24 bears a polymerizable group by addition. Examples of these addition polymerizable cationic surfactants are: CH3 CH, H3C - (CH2) 11-CH3 Br H3C N (CH2) 7-CH3 Br (CH2) 11 -COO-C (CH3) = CH2 (CH2) 11 -COO-C (CH3) = CH2 Phosphorus lipids represent an example of suitable sutureionic surfactants. Mesophases, particularly the lio-tropic crystalline phases, without additional surfactant, are preferred. (v) comonomers or hydrophobic or hydrophobic comacomers: A comonomer or comacomer that is contained in the meso-phases according to the invention, can be hydrophilic or hydrophobic, or a mixture of both. Suitable comonomers include, in particular, those which are normally used for the preparation of contact lenses and biomedical materials. It is understood that a hydrophobic comonomer (a) means monomers that typically give, as a homopolymer, polymers that are insoluble in water and can absorb less than 10 weight percent water. Analogously, it is understood that a hydrophilic comonomer means a monomer that typically gives, as a homo-lime, a polymer that is soluble in water or can absorb at least 10 percent by weight of water. Suitable hydrophobic comonomers include, without this list being exhaustive, acrylate and alkyl methacrylates of 1 to 18 carbon atoms and of cycloalkyl of 3 to 18 carbon atoms, acrylamides and methacrylamides of alkyl of 3 to 18 carbon atoms, acrylonitrile , methacrylonitrile, vinyl alkanoates of 1 to 18 carbon atoms, alkenes of 2 to 18 carbon atoms, haloalkenes of 2 to 18 carbon atoms, styrene, lower alkyl-styrene, vinyl ethers of lower alkyl, acrylates and perfluoroalkyl methacrylates of 2 to 10 carbon atoms, or the correspondingly partially fluorinated acrylates and methacrylates, perfluoroalkyl acrylates and methacrylates of 3 to 12 carbon atoms-ethyl-thiocarbonylaminoethyl, acryloxy- and methacryloxy-alkylsiloxanes, N-vinylcarbazole, and alkyl esters of 1 to 12 carbon atoms of maleic acid, fumaric acid, itaconic acid, mesaconic acid, and the like. Preferred comonomers are, for example, acrylonitrile, alkyl esters of 1 to 4 carbon atoms of vinyl unsaturated carboxylic acids having from 3 to 5 carbon atoms, or vinyl esters of carboxylic acids having up to 5 carbon atoms. Examples of suitable hydrophobic comonomers include methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, isobutyl acrylate (IBA), iso-octyl acrylate (OA), isodecyl acrylate (DA), acrylate. of cyclohexyl, 2-ethylhexyl acrylate (EHA), methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl acrylate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl valerate, styrene, chloroprene, vinyl, vinylidene chloride, acrylonitrile, 1-butene, butadiene, methacrylonitrile, vinyltoluene, vinylethylether, perfluorohexylethylcarbonylaminoethyl methacrylate, isobornyl methacrylate, trifluoroethyl methacrylate, hexafluoroisopropyl methacrylate, hexafluorobutyl (meth) acrylate (HFBMA and HFBA), tris-trimethylsilyloxy-silyl-propyl methacrylate (TRIS), 3-methacryloxypropylpentamethyldisiloxane, and bis (methacryloxypropyl) tetramethyldisiloxane. Preferred examples of the hydrophobic comonomers are methyl methacrylate, IBA, HFBA, HFBMA, OA, EHA, DA, TRIS and acrylonitrile. Suitable hydrophilic comonomers include, without this list being conclusive, lower alkyl acrylates and methacrylates substituted by hydroxyl, acrylamide, methacrylamide, lower alkyl acrylamides and methacrylamides, ethoxylated acrylates and methacrylates, hydroxy substituted lower alkyl acrylamides and methacrylamides, hydroxyl substituted lower alkyl vinyl ethers, sodium vinyl sulfonate, - sodium rensulfonate, 2-acrylamido-2-methylpropansulphonic acids, N-vinylpyrrole, N-vinyl-2-pyrrolidone, 2-vinyloxazoline, 2-vinyl-4,4'-dialkyloxazolin-5-one, 2- and 4 vinylpyridine, vinyl unsaturated carboxylic acids having a total of 3 to 5 carbon atoms, lower aminoalkyl (wherein the term "amino" also includes quaternary ammonium), lower monoalkyl-aminoalkyl and di-lower alkyl acrylates and methacrylates -aminoalkyl, allyl alcohol, and the like. Preferred comonomers are, for example, hydroxyl-substituted 2-N-vinyl-pyrrolidone, acrylamide, methacrylamide, hydroxy-substituted lower alkyl acrylates and methacrylates, hydroxyl-substituted lower alkyl acrylamides and methacrylamides, and vinyl unsaturated carboxylic acids having a total of 3 to 5 carbon atoms. Examples of suitable hydrophilic comonomers include hydroxyethyl methacrylate (HEMA), hydroxyethyl acrylate, hydroxypropyl acrylate, 2-hydroxypropyl methacrylate hydrochloride trimethylammonium (BlemerRQA, for example from Nippon Oil), dimethylaminoethyl methacrylate (DMAEMA), methacrylamide of dimethylaminoethyl, acrylamide, methacrylamide, N, N-dimethyl-acrylamide (DMA), allyl alcohol, vinylpyridine, glycerol methacrylate, N- (1, l-dimethyl-3-oxobutyl) acrylamide, N-vinyl-2-pyrrolidone ( NVP), acrylic acid, methacrylic acid, and the like. Preferred hydrophilic comonomers are 2-hydroxyethyl methacrylate, dimethylaminoethyl methacrylate, 2-hydroxypropyl methacrylate hydrochloride trimethylammonium, N, N-dimethyl acrylamide, and N-vinyl-2-pyrrolidone. Suitable hydrophilic or hydrophobic commacromers include vinyl-functionalized olers, for example a vinyl-functionalized oler comprising a above-mentioned segment A or B, such as a vinyl-functionalized polyalkylene glycol or a vinyl-functionalized polysiloxane. Preferably, the mesophases according to step b) do not comprise any comonomer or comrade. (vi) effective pharmaceutical agents: The mesophases of the invention may contain suitable effective pharmaceutical agents, for example, proteins, enzymes, vitamins, disinfectants, bactericides, and the like. In a preferred embodiment of the invention, the invention mesophases are prepared from, and therefore comprise, one or more different prepolymers of the invention; water, which may contain physiologically acceptable salts; and optionally a photoinitiator and / or an additional solvent selected from the group consisting of a monohydric or polyhydric alcohol, a carboxylic acid amide, acetonitrile, and dimethyl sulfoxide. Still more preferred are mesophases prepared from, and therefore consisting of, one or more different prepolymers, water, and optionally a photoinitiator. The mesophases of the invention are preferably exempt, or at least substantially free, from undesired constituents, such as, for example, the monomeric, oligomeric, or polymeric starting materials used for the preparation of the prepolymer; free of secondary products formed during the preparation of the prepolymer; and / or free of salts. The preparation of the at least partially bicontinuous mesophases, step b), can be characterized, for example, by comprising the steps of: (i) selecting the proportions of the prepolymer, an aqueous solution, and optionally other components that give a microstructure that is at least partially bicontinuous; (ii) cause or allow the bicontinuous microstructure to form. Suitable proportions of the prepolymer, the aqueous solution, and optionally other components giving a bicontinuous microstructure can be determined by simple experimentation. For example, the components that make up the mesophase are mixed in such a way that they form a homogeneous transparent phase, and then the phase is inspected under a polarization microscope, or using the SAXS method (small-angle X-ray scattering), or SANS (small-angle neutron scattering). In addition, it is possible to first determine a phase diagram of the mixture of the components that make up the mesophase. The phase diagram indicates the absence or presence of homogeneous mesophase areas of a given mixture, and therefore, can be used to establish compositions that are suitable for the preparation of a bicontinuous microstructure as required. The mesophases of the present invention can be prepared by simply mixing suitable quantities of the prepolymer, the aqueous solution, and optionally other components in any order, at a temperature, for example, from 0 ° C to 100 ° C, preferably 10 ° C. at 50 ° C and more preferably from 15 ° C to 40 ° C. Mesophases can be formed spontaneously, or over agitation and / or rest for an adequate period. For example, the components forming the mesophase are mixed for about 1 minute to 1 week, preferably for 30 minutes to 5 days, and more preferably for 2 hours to 3 days, in order to form a mesophase that is ready for processing additionally according to the invention. According to a further embodiment of the invention, the mesophases can be obtained by preparing an emulsion from the prepolymer, the optional additional components, and an excess of the aqueous solution, and then the water is distilled at elevated temperature, until that a homogenous transparent mesophase is formed. According to another embodiment of the invention, a mesophase can be obtained by simply preparing a melt of the prepolymer, and optionally other components in the absence of an aqueous solution which is especially suitable for prepolymers having a low melting point or transition point. glass. The bicontinous mesophases of the invention comprise, for example, 10 to 100 weight percent prepolymer (s), from about 0 to about 90 weight percent aqueous solution, and from 0 to 40 weight percent other components. Preferably, the bicontinous mesophases of the invention comprise from about 30 to about 85 weight percent prepolymer (s), from about 15 to about 70 weight percent aqueous solution, and from 0 to 10 percent by weight of other components. Particularly preferred mesophases comprise from 30 to 75 weight percent of prepolymer (s), and from 25 to 70 weight percent of aqueous solution. The mesophases according to the invention can be introduced into an ophthalmic mold in a manner known per se, such as, especially, by conventional metering introduction, for example, by extrusion. Suitable molds are generally customary molds for contact lenses as are known in the state of the art. Accordingly, the contact lenses according to the invention can be manufactured, for example, in a manner known per se, for example in a conventional "spinning casting mold", as described, for example, in FIG. U.S. Patent No. US-A-3, 408, 429, or by the so-called Full Mold process in a static mold, as described, for example, in the U.S. Pat. A-4,347,198. Appropriate molds are made, for example, from polypropylene. Quartz, sapphire glass, and metals, for example, are suitable materials for reusable molds. The crosslinking can be triggered in the mold, for example, by actinic radiation, such as, for example, ultraviolet light, or by ionizing radiation, such as, for example, gamma radiation, electron radiation, or X radiation. Crosslinking, where appropriate, it can also be triggered in a thermal or electrochemical manner. Attention is drawn to the fact that the crosslinking can be carried out according to the invention in a very short time, for example, in =. 60 minutes, preferably = .20 minutes, more preferably =. 5 minutes, and still more preferably in =. 1 minute, especially in up to 30 seconds, in a particularly preferable manner as disclosed in the examples. The reaction conditions are conveniently chosen in such a way that the configuration of the bicontinal mesophase is retained at least partially during the crosslinking. According to the above, the molded article obtained, for the most part, is optically transparent, and has a morphology that includes at least partially bicontinuous phases. 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. Although in the processes that have been proposed in the state of the art, it is usually necessary at that point, to follow the purification steps, for example, extraction, and also the steps for the hydration of the resulting molded articles, especially lenses. contact, these steps, although possible, are preferably not necessary in the process according to the invention. This is because, in a preferred embodiment of the invention, the mesophases do not comprise undesirable low molecular weight constituents. According to the above, the crosslinked product also does not comprise these constituents, and consequently, a subsequent extraction is not necessary. Because the crosslinking is carried out in a substantially aqueous mesophase, subsequent hydration is not necessary. These two advantages mean, among other things, that a complicated after-treatment of the resulting molded articles, especially contact lenses, is eliminated. Contact lenses that can be obtained according to the process according to the invention, accordingly, according to a convenient embodiment, they are distinguished by the fact that they are suitable for their intended use without extraction. "Intended use" in this context means especially that contact lenses can be used in the human eye. The contact lenses that can be obtained according to the process according to the invention, according to a convenient modality, are also distinguished by the fact that they are suitable for their intended use without hydration. Accordingly, the process according to the invention is outstandingly suited for the economical manufacture of a large number or molded articles, such as contact lenses, in a short time. Other examples of molded articles are biomedical articles, in particular ophthalmic molded articles, for example artificial corneas, intraocular lenses, or eye bandages. Still other molded articles obtainable according to the claimed process are molded articles that can be used in surgery, such as heart valves, artificial arteries, or the like.; catalysts, and also coatings, films or membranes, for example membranes for diffusion control, photo-structurable films for storage of information, or photoresist materials, for example membranes or molded articles for recording resistances or screen printing resistors, in addition particles, in particular micro-particles, capsules, in particular microcapsules, films and plasters for drug application systems.

The process of the invention is especially suitable for the manufacture of mass produced articles, such as, for example, contact lenses that are worn for a short time, for example for 1 month, a week, or only 1 day, and then they are replaced by new lenses. This is in particular because the contact lenses prepared according to the invention can be used for their intended use without subsequent treatment steps, such as extraction or hydration. In addition, contact lenses that can be obtained according to the process of the invention, have a range of unusual and extremely convenient properties, and therefore, are suitable for long periods of use (true prolonged use, that is, 7 days or more). Among these properties are, for example, its excellent compatibility with the human cornea and with the lacrimal fluid, if necessary after an adequate surface treatment (for example, coating) based on a balanced ratio between the water content, the oxygen permeability and mechanical and absorbent properties. This results in high como-didad and an absence of irritation and allergenic effects. Due to their favorable permeability properties with respect to gases (C02 and 02), to different salts, nutrients, water and various other tear fluid components, contact lenses prepared according to the process of the invention have no effect, or virtually no effects, on the natural metabolic processes in the cornea. In addition, contact lenses that can be obtained according to the process, are optically clear and transparent, have a high shelf life and good mechanical properties, for example, with respect to modulus of elasticity, elongation to breakage, or dimensional stability . All the advantages mentioned above apply naturally not only to contact lenses, but also to other articles molded according to the invention. In the following examples, unless otherwise expressly reported, the amounts are amounts by weight, and the temperatures are degrees Celsius.

Preparation of a Macroinitiator.

Example 1: In a 250 milliliter two-necked round bottom flask fitted with a Soxhlet extractor, with a condenser and a chamber in the second ground joint, the Soxhlet extractor was filled with a molecular sieve (4 A). dissolve 26.5 grams (6.34 millimoles) of a,? - bis (3-hydroxypropyl) -polydi-methylsiloxane (IM 15 by Wacker Chemie, Munich, Germany, purified on a thin film evaporator, 0.43 milliequivalents OH / gram, Mn = 4651) in 90 milliliters of hexane, and distilled under reflux for 17 hours in a nitrogen atmosphere. Then the solution still contains 21 ppm of water. Subsequently, the solution is concentrated to 60 milliliters of hexane, cooled to 0 ° C, and 3.60 grams (45.5 milli-moles) of pyridine are added. Then 12.4 grams (43.9 milli-moles) of trifluoromethanesulfonic acid anhydride (Fluka Chemie AG, Buchs, Switzerland) are added over 15 minutes, and the mixture is stirred for another 30 minutes at a temperature of 0 ° C. After the addition of 20 milliliters of chloroform (water content <10 ppm), the suspension is filtered under vacuum using a G4 glass filter funnel, and then evaporated in a high vacuum (0.6-2 mbar). The yield is 18 grams of an orange oil. The oil in turn is dissolved in 40 milliliters of dry hexane (water content < 10 ppm), activated charcoal is added, and then the mixture is stirred for about 2 minutes, and filtered again. After evaporation of the solution, the yield is 15.8 grams of a clear, colorless oil. XH-NMR (CDC13, 250 MHz); 0 ppm (CH3-Si), 0.5 ppm (-CH2CH2-Si-), 1.8 ppm (CH2-CH2-CH2-), 4.4 ppm (CF3S03CH2-CH2-). Functionality: > 95 percent (based on the data of ^ -R N), that is, > 0.40 milliequivalents of triflate / gram.

Preparation of a Segmented Amphiphilic Copolymer.

Example 2: 2.22 grams (26.1 millimoles) of 2-methyl-2-oxazoline and 6.94 grams (1.4 millimoles) of the pre-stopped macroinitiator in Example 1 are added to 15 milliliters of 1,2-dichloroethane (water content of 5 ppm) at room temperature. After the solution is stirred for 1.5 hours at room temperature, the temperature is increased to 40 ° C. After 48 hours, the solution is cooled to room temperature, and 5.5 milliliters of a 0.5 N KOH / EtOH solution is added. This solution is then stirred for 1 hour, and subsequently evaporated in a high vacuum (0.6-2 mbar). ). XH-NMR; 0 ppm (CH3-Si), 2.0-2.1 ppm (CH3CON <), 3.3-3.5 ppm (> N-CH2-CH2-N <) Functionality: OH titration: 0.40 milliequivalents / gram Titration of terminal groups residual cations: 0.02 milliequivalents / gram. Chromatography of gel permeation in tetrahydrofuran: 1 peak with hump against the lowest molecular weights; maximum peak at approximately 6,500, based on polystyrene as a standard.

Preparation of Functionalized Segmented Amphiphilic Copolymer.

Example 3: In a round bottom flask, 6.62 grams (2.64 milliequivalents) of the segmented amphiphilic copolymer obtained in Example 2, at room temperature, are dissolved in 20 milliliters of dry ethyl acetate (water content < 10 ppm) and 420 milligrams (2.7 millimoles) of 2-isocyanatoethyl methacrylate (IEM) and about 40 milligrams of dibutyltin dilaurate are added. The solution is stirred for 48 hours in the absence of light, and then it is evaporated in a high vacuum (0.6-2 mbar) for 5 hours at a temperature of 0 ° C. 6.89 grams of a colorless solid macromer is obtained which is believed to conform to the formula: (x = 13, y = 63) Functionality: OH titration: 0.11 milliequivalen-te / gram (27.5 percent of the OH groups are unreacted). Gel permeation chromatography in tetrahydrofuran: 2 peaks, maximum peaks at 400 (small peak) and at 6,500, based on polystyrene as a standard.

Examples 4-14: Other segmented amphiphilic copolymers (ASC) are prepared according to the procedure of Examples 1 to 3, but using different amounts of the starting materials, already, α-bis (2-hydroxyethoxypropyl) -polydimethylsiloxane (Shin) -Etsu) instead of o,,? -bis (3-hydroxypropyl) -polydimethylsiloxane. The compositions are summarized in Table 1.

Table 1 * The cationic ring opening polymerization was conducted at 70 ° C for 2 hours, followed by room temperature overnight, instead of using the treatment given in Example 2.

Preparation of an ophthalmic molded article Example 15: 1.11 grams of segmented afifilic copolymers according to Example 5 are mixed with 1.09 grams of deionized water and 1 weight percent relative to the amount of water of Irgacure 2959. After 4 On mixing days, the formulation is centrifuged, and filled into polypropylene molds, and cured with ultraviolet light at an intensity of 2.4 mW / cm for 15 minutes. After curing, the molded articles obtained are extracted in isopropanol for 60 hours, rebalanced in water, and autoclaved at 120 ° C. The molded articles are transparent, and have a high ion permeability and oxygen permeability value (for determination, see, for example, PCT Publication Number WO 96/31792), and also good mechanical stability.

Examples 16-27: Other molded articles are obtained by mixing the amounts of segmented amphiphilic copolymers, deionized water, photoinitiator (Irgacure 2959), and other optional components, as given in Table 2, by filling the mixture in polypropylene molds, curing with ultraviolet light at an intensity of 2 mW / cm at 310 nanometers for 90 seconds, and removing the molded articles resulting from the molds.

Table 2 The molded articles obtained are extracted in each case in isopropanol overnight, rebalanced in water, and autoclaved at 121 ° C for 30 minutes. The molded articles are transparent in each case, and have a high value of oxygen permeability and ion permeability, and also a good mechanical stability.

Example 28-29: Molded articles according to Examples 19 or 20 are prepared, with the exception that extraction and rebalancing are omitted in each case. The molded articles resulting in the same manner are transparent, and have a high value of oxygen permeability and ion permeability.

Example 30: A molded article according to Example 17 is prepared, with the exception that the segmented amphiphilic copolymer is previously purified as follows: 4.5 grams of the segmented amphiphilic copolymer of Example 10 are dissolved in 370 milliliters of ethanol. 105 milliliters of the solution are poured into a reverse osmosis filtration unit (Millipore Corp.) equipped with a regenerated cellulose membrane (molecular weight cut-off of 1,000) on a polypropylene support (Millipore Corp.). Filtration is conducted at 5.6 kg / cm2. After about 10 hours, the yield is 66 percent, and the low molecular weight components have been removed from the macromer. Then the molded article is prepared without subsequent extraction or rebalancing; It is transparent, and has a high value of oxygen permeability and ion permeability.

Example 31: (i) Preparation of a macromer: A mixture of 10.0 grams of polyethylene glycol methacrylate (Mn = 400, Polyscience) in 17.5 milliliters of dry methylene chloride is added dropwise for 1.5 hours to 16.7 grams. of isophorone diisocyanate (IPDI) in 21.6 grams of 1,2-dichloroethane and 5 drops of dibutyltin dilaurate (DBTDL) (0.07 grams). The reaction is stopped after 20 hours, and the product is extracted twice with dry hexane. Then, the resulting product of PEG-methacrylate-IPDI is stabilized with 2,400 ppm of 2,6-diterbutyl-p-cresol (BHT). 5.0 grams of, -bis (2-hydroxyethoxypropyl) -polydimethylsiloxane (Mn = 2000, Shin-Etsu) are dried by azeotropic distillation in methylene chloride. Next, 3.6 grams of the above PEG-methacrylate-IPDI, and 25 drops of dibutyltin dilaurate are added. The mixture is stored for 1 day at approximately 40 ° C. Then 0.0008 grams of phenothiazole are added in 1 gram of methylene chloride, and the solvent is evaporated. Preparation of an ophthalmic molded article: 1.3 grams of the previously prepared macromer are mixed with 0.70 grams of deionized water, and 0.035 weight percent in relation to the amount of water, of Irgacure 2959. The mixture is filled into polypropylene molds , and is cured for 45 seconds with ultraviolet light at an intensity of 2 mW / cm2 at 310 nm, with a Macam lamp (400W). The resulting molded article is optically transparent. Example 32: (i) Preparation of a macromer: 5.0 grams of α, β-bis (2-hydroxyethoxypropyl) -polymethylsiloxane (Mn = 2,000, Shin-Etsu) in 20 grams of dry methylene chloride are added dropwise to a mixture of 1.0 grams of IPDI, 5.0 grams of methylene chloride, and 10 drops of DBTDL for 35 minutes. The reaction is maintained for 4.5 hours at 40 ° C (IPDI-PDMS-IPDI). Then a mixture of 1.93 grams of polyethylene glycol acrylate (PEG-acrylate, Mn = 375, Aldrich) and 20 milliliters of methylene chloride is added dropwise to the IPDI-PDMS-IPDI solution with 20 extra drops of DBTDL. The reaction is maintained at room temperature while another 10 drops of DBTDL are added after 16.5 hours, another 0.4 grams of PEG-acrylate with 5 drops of DBTDL after 24 hours, and another 0.1 grams of PEG-acrylate with 5 drops of DBTDL. DBTDL after another 65 hours. The reaction mixture is maintained for another two hours at room temperature, and then the solvent evaporates. Preparation of an ophthalmic molded article: 1.3 grams of previously prepared macromer are mixed with 0.71 grams of deionized water, and 0.035 weight percent in relation to the amount of water, of Irgacure 2959. The mixture is filled into polypropylene molds, and cured for 30 seconds with ultraviolet light at an intensity of 12 mW / cm at 310 nanometers with a Macara lamp (400W). The resulting molded article is transparent, and has a high permeability value of the ions and oxygen permeability. Example 33: 0.3 grams of the polymers of Examples 14 or 31 are heated in each case between quartz plates for 10 minutes at 101 ° C. Then, the well-spread transparent polymer fusions are irradiated with ultraviolet for 3 minutes at 2 mW / cm2 at 310 nanometers with a Macam lamp (400 W). The transparent films obtained are hydrated in water, and are transparent in each case. Example 34: The ophthalmic molded articles of Examples 16 and 19 are analyzed by stick angle X-ray scattering (SAXS). In accordance with its diffraction pattern, the molded article of Example 16 has a lamellar morphology, and that of Example 19 has a hexagonal morphology. Example 35: 70 weight percent of the segmented amphiphilic copolymer of Example 11 is mixed with 29.8 weight percent of 300 milliosmoles / liter of phosphate buffered serum and 0.2 weight percent of Irgacure 2959. The mixture is filled in polypropylene molds, cured with ultraviolet light at an intensity of 2 mW / cm2 at 310 nanometers for 90 seconds, and the resulting molded articles are removed from the molds. The molded articles are transparent, and have a high value of permeability to the ions and of permeability to oxygen.

Claims (25)

RETVTNDTCACTO KS

1. A process for manufacturing a molded article, which comprises the following steps: a) providing at least one prepolymer comprising one or more crosslinkable groups, wherein the prepolymer is a segmented amphiphilic copolymer comprising at least one hydrophobic segment A and a hydrophilic segment B; b) preparing a at least partially bicontinuous mesophase of the prepolymer; c) introducing the mesophase obtained in an ophthalmic mold; d) unleash the crosslinking; and e) opening the mold, in such a way that the molded article can be removed.

2. A process according to claim 1, wherein the molded article is selected from the group consisting of ophthalmic molded articles, membranes, catalysts, and molded articles that are useful in surgery.

3. A process according to claim 1 or 2, wherein the prepolymer has a weight average molecular weight of 1,000 to 50,000.

4. A process according to any of claims 1 to 3, wherein the hydrophobic segment A of the prepolymer is a polysiloxane or a perfluoropolyalkylether.

5. A process according to any of claims 1 to 4, wherein the hydrophilic segment B of the prepolymer is a nonionic segment selected from the group consisting of a polyoxyalkylene, polysaccharide, polypeptide, poly (vinylpyrrolidone), acrylate and methacrylate of polyalkyl, polyhydroxyalkyl acrylate and methacrylate, polyacyl-alkyleneimine, polyacrylamide, polyvinyl alcohol, polyvinyl ether, and polyol, or is a polycationic segment selected from the group consisting of a polyallylammonium, polyethyleneimine, polyvinylbenzyltrimethylammonium, polyaniline, sulfonated polyaniline, polypyrrole, and a polypyridinium segment, or a polyanionic segment selected from the group consisting of a polyacrylic and polymethacrylic acid, a polythiophenoacetic acid, a polystyrenesulfonic acid, or a suitable salt thereof.

6. A process according to any of claims 1 to 5, wherein segments A and B of the prepolymer are linked by a non-hydrolysable bond or by a bridging member selected from the group consisting of a carbonyl functional group, carbonate, ester, amide, urea, or urethane, and an alkylene, cycloalkylene, aralkylene, arylene, or heterocyclic group containing one or two of the functional groups mentioned.

7. A process according to any of claims 1 to 6, wherein the prepolymer contains the segments A and B linked together through a non-hydrolysable bond, and the segment A comprises a polysiloxane block having groups Alkylene terminal of the formula: where n is an integer from 5 to 700; Alk is alkylene having up to 20 carbon atoms; from 80 to 100 percent of the radicals Rl7 R2, R3, and R4, independently of one another, are alkyl, and from 0 to 20 percent of the radicals R1 R2, R3, and R4, independently of each other, are alkenyl, aryl, fluoroalkyl, or cyanoalkyl.

8. A process according to claim 7, wherein the segment B of the prepolymer is a segment of polyacylalkylimine that can be derived from a cyclic imino ether of the formula (IV): wherein R9 represents a hydrogen atom, an alkyl, hydroxyalkyl, or alkenyl group having up to 22 carbon atoms, and optionally containing an ether, ester, or urethane group, a cycloalkyl group, an aralkyl group, or a group aril; and t is 2 or 3.

9. A process according to claim 8, wherein the cyclic imino ether is 2-methyl-2-oxazoline, a 2-alkenyloxazoline, a 2- (hydroxyalkyl) oxazoline, or a methacrylate of 2-isocyanatoethyl thereof.

10. A process according to any of claims 1 to 6, wherein the prepolymer is of the formula: CP-PAO-DU-ALK-PDMS-ALK-DU-PAO-CP (V) wherein PDMS is a poly (disubstituted siloxane) divalent; CP is an isocyanatoalkyl acrylate or methacrylate, wherein the urethane group is linked to the terminal carbon on the PAO group; PAO is a divalent polyoxyalkylene; DU is a diurethane; wherein an oxygen of the urethane linkage (1) is bonded to the PAO group, and an oxygen of the urethane linkage (2) is bonded to the ALK group. and ALK is an alkylene or oxyalkylene group having at least 3 carbon atoms.

11. A process according to any of claims 1 to 6, wherein the prepolymer comprises at least one segment of the formula (VI): wherein: (a) is a polysiloxane segment, (b) is a polyol segment containing at least 4 carbon atoms, Zi is segment X2-R'-X2 or a group Xi, R1 is a divalent radical of a organic compound having up to 20 carbon atoms, and Xi and each X2, independently of the others, are a divalent radi-lime containing at least one carbonyl group, and (d) is a radical of the formula (VII): Xa - - (Y) u-Pi (VII) where: Pi is a group that can be polymerized by free radicals; Y and X3, independently of one another, are a divalent radical containing at least one carbonyl group; kl is 0 or 1; and L is a bond or a divalent radical having up to 20 carbon atoms of an organic compound.

12. A process according to any of claims 1 to 11, wherein the mesophase is prepared from one or more prepolymers, an aqueous solution, and optionally other components.

13. A process according to any of claims 1 to 12, wherein the aqueous solution comprises pure water, or a mixture of water and one or more miscible solvents in water and / or salts.

A process according to claim 12 or 13, wherein the optionally additional components are selected from the group consisting of a photoinitiator, a thermal initiator, a reduction-oxidation initiator, a surfactant, a comonomer, a commacromer , and a pharmaceutically effective agent.

15. A process according to any of claims 1 to 14, wherein the mesophase is prepared from one or more different prepolymers; water that may contain physiologically acceptable salts; and optionally a photoinitiator and / or an additional solvent selected from the group consisting of a monohydric or polyhydric alcohol, a polyether, a carboxylic acid amide, acetone, acetonitrile, and dimethyl sulfoxide.

16. A process according to any of claims 1 to 15, wherein the mesophase is prepared from one or more different prepolymers, water, and optionally a photoinitiator.

17. A process according to any of claims 1 to 16, wherein the preparation of the mesophase comprises the steps of: (i) selecting the proportions of the prepolymer, an aqueous solution, and optionally other components that give a microstructure that is at least partially bicontinuous; Y (ii) cause or allow the bicontinuous microstructure to form.

18. A process according to claim 17, wherein the bicontinuous microstructure is formed by mixing the prepolymer, the aqueous solution, and the optionally additional components, and maintaining the mixture at a temperature of 0 ° C to 100 ° C for a period of time. of time from 1 minute to 1 week with optional agitation.

19. A process according to any of claims 1 to 11, wherein the formation of the mesophase comprises preparing a fusion of one or more prepolymers, and optionally other components.

20. A process according to any of claims 1 to 19, wherein the mesophase obtained according to step b) is of a crystalline structure, preferably of a lamellar, hexagonal, or cubic structure, and in a particular manner preferable, of a cubic structure.

21. A process according to any of claims 1 to 20, where the crosslinking is carried out for a period of time of =. 60 minutes .

22. A process according to any of claims 1 to 21, wherein the molded article is a contact lens.

23. An ophthalmic molded article, particularly a contact lens, which can be obtained according to the process of any of claims 1 to 21.

24. A process according to any of claims 1 to 21, wherein the article Molded is a membrane.

25. A membrane, which can be obtained according to the process of any of claims 1 to 21.