HK1184750B - Vinyl alcohol ophthalmic lens molds, ophthalmic lenses molded therein, and related methods - Google Patents

Description

Vinyl alcohol ophthalmic lens molds, ophthalmic lenses molded therein, and related methods

Technical Field

The present invention relates to ophthalmic lens molds comprising at least one vinyl alcohol copolymer having high amorphous content, ophthalmic lenses cast molded using at least one of these vinyl alcohol copolymer molds, and related methods. More specifically, the present invention relates to contact lens molds made from at least one vinyl alcohol copolymer having an average level of crystallinity of about 30% or less, contact lenses cast molded using at least one of these molds, and methods of making contact lenses, including silicone hydrogel contact lenses, using these molds.

Background

In a cast molding process for manufacturing ophthalmic lenses, such as contact lenses, a reactive mixture or polymerizable lens precursor composition is cured in a lens-forming cavity defined by a first mold member having a concave lens-forming surface and a second mold member (or female and male mold members, respectively) having a convex lens-forming surface. These mold parts are typically manufactured by injection molding a thermoplastic polymer into a mold cavity. Examples of thermoplastic polymers used to make ophthalmic lens molds include non-polar thermoplastic polymers such as polypropylene, polystyrene, and polyethylene; and polar thermoplastic polymers such as ethylene-vinyl alcohol copolymers and poly (vinyl alcohol) homopolymers. When cast molding a contact lens, after placing the polymerizable composition into the first mold member, the first and second mold members are brought together or coupled together to form a lens assembly having a lens-shaped cavity therebetween. The mold assembly is then cured to polymerize the polymerizable composition, forming a polymerized lens body in the lens-shaped cavity of the mold assembly.

SOARLITE has been produced from an ethylene-vinyl alcohol (EVOH) copolymer having a high crystal content (and a low amorphous content), such as available from Nippon Gohsei, Ltd of Osaka, Japan^TMS) cast molding contact lenses, including silicone hydrogel contact lenses, in the molds made. Some EVOH copolymers have a crystallinity level of about 40% or greater than 40%. It has been found that molding silicone hydrogel lenses in EVOH molds can produce lenses having ophthalmically acceptably wettable surfaces. Previously, it was necessary to apply a surface treatment, such as a plasma treatment, or to include an interpenetrating network of a polymeric wetting agent in silicone hydrogel contact lenses to provide an ophthalmically acceptable wettability of the lens surface upon hydration. However, EVOH is an expensive material, which can adversely affect production costs. Molds made from EVOH are generally harder and more brittle than is desirable, and it is difficult to release the lens body from the mold members of the mold assembly after curing, which can adversely affect lens yield and cost.

It has also been proposed to use poly (vinyl alcohol) (PVOH) forms, including modified forms of PVOH, to form contact lens molds. Although these forms of PVOH appear attractive for their water solubility, they are not ideal for use as contact lens molds. For example, it is difficult to injection mold contact lens molds using these materials because the conventional melt processing temperature and thermal degradation temperature of pure PVOH are nearly the same. Although some modifications of PVOH have been proposed for use as contact lens molds, these modifications of PVOH retain some of the undesirable properties of pure PVOH, such as high crystalline content which reduces light transmission through the material, slow dissolution in water at lower temperatures, and incomplete dissolution of portions of the material. Furthermore, aqueous solutions of pure or modified PVOH can easily gel or foam, and these materials can produce cloudy aqueous solutions. While the prospect of contact lens molds that are soluble in water would be attractive, these undesirable characteristics make it difficult to commercially manufacture contact lenses using neat or modified forms of PVOH.

In view of the foregoing, it can be appreciated that there is a need for contact lens molds comprising novel material types for cast molding ophthalmic lenses, including silicone hydrogel contact lenses, novel ophthalmic lenses cast molded using molds comprising these novel material types, and related methods of manufacture using less expensive, more process-compatible molding materials. There is a particular need for materials that can be injection molded to form contact lens molds that can be used to cast mold silicone hydrogel contact lenses having ophthalmically acceptably wettable lens surfaces, without applying a surface treatment (e.g., plasma) to the lens body, or without the presence of components in the lens-forming composition that can form an interpenetrating network (IPN) of wetting agent in the lens body during lens curing.

All publications, including patents, published patent applications, scientific or commercial publications, etc., cited in this specification are herein incorporated by reference in their entirety.

Disclosure of Invention

In a first example, the present invention is directed to a method of manufacturing an ophthalmic lens comprising: providing at least one vinyl alcohol copolymer having a high amorphous content; forming at least one of a first mold member and a second mold member using the at least one vinyl alcohol copolymer with high amorphous content, the first mold member comprising a concave molding surface configured to mold an anterior surface of a lens and the second mold member comprising a convex molding surface configured to mold a posterior surface of a lens, the first mold member and the second mold member configured to form a lens-shaped cavity therebetween when combined as a mold assembly; placing a polymerizable composition comprising at least one hydrophilic monomer into the first mold member or the second mold member; assembling the mold assembly by contacting the first mold member with the second mold member, thereby forming the lens-shaped cavity therebetween, wherein the polymerizable composition is contained in the lens-shaped cavity of the mold assembly; and curing the polymerizable composition in the mold assembly to form a cast-molded polymeric reaction product in the lens-shaped cavity of the mold assembly, the polymeric reaction product comprising an ophthalmic lens body.

In one example, the at least one vinyl alcohol copolymer with high amorphous content is at least one vinyl alcohol copolymer having an average level of crystallinity from about 10% to about 30%, or from about 15% to about 25%, or from about 17% to about 20%.

In another example, the at least one vinyl alcohol copolymer with high amorphous content has a melting point of about 140 ℃ to about 190 ℃, or about 155 ℃ to about 180 ℃, or about 160 ℃ to about 172 ℃.

In another example, the at least one vinyl alcohol copolymer with high amorphous content has a glass transition temperature of from about 60 ℃ to about 85 ℃, from about 65 ℃ to about 80 ℃, or from about 70 ℃ to about 76 ℃.

In one example, the at least one vinyl alcohol copolymer with high amorphous content is a polar polymer.

In a particular example, the at least one vinyl alcohol copolymer with high amorphous content comprises nichigo-POLYMER^TM(Nippon synthetic chemical industry Co., Ltd., Osaka, Japan).

In one example of the method of manufacturing an ophthalmic lens, the step of placing a polymerizable composition into the first mold member or the second mold member comprises placing a polymerizable composition comprising at least one silicone monomer, silicone macromer, silicone prepolymer, or combination thereof, and at least one hydrophilic monomer into the first mold member, and wherein the ophthalmic lens body comprises a silicone hydrogel contact lens body.

In another example of the method of manufacturing an ophthalmic lens, the method of forming at least one of the first mold member and the second mold member using the at least one vinyl alcohol copolymer with high amorphous content comprises injection molding at least one of the first mold member and the second mold member. In other words, one or both of the two mold members comprise the at least one vinyl alcohol copolymer with high amorphous content, and one or both of the two mold members are made by injection molding the at least one vinyl alcohol copolymer with high amorphous content. In one example, the step of injection molding at least one of the first mold member and the second mold member comprises forming a molding surface of at least one of the first mold member and the second mold member entirely by injection molding. In other words, the molding surface of one or both of the two mold members is formed entirely by injection molding the at least one vinyl alcohol copolymer with high amorphous content, as opposed to forming the molding surface, for example, by a combination of molding and machining (lathing), lathing, or cutting. In another example, the step of injection molding at least one of the first mold member and the second mold member comprises forming a body of at least one of the first mold member and the second mold member by injection molding, and forming a molding surface of at least one of the first mold member and the second mold member by machining, lathing, or cutting the injection molded body. In another example, a method of injection molding can include injection molding the at least one vinyl alcohol copolymer with high amorphous content using a process setting selected from the group including: a melt temperature of about 180 ℃ to about 250 ℃, a barrel temperature of about 180 ℃ to about 250 ℃, a top temperature of about 30 ℃ to about 70 ℃, a mold tool temperature of about 30 ℃ to about 95 ℃, a hold time of about 1 second to about 5 seconds, an injection velocity of about 50 mm/second to about 250 mm/second, a plasticizing velocity of about 100 mm/second to about 300 mm/second, an injection pressure of about 50 Bar (Bar) to about 180 Bar, a hold pressure of about 10 Bar to about 200 Bar, a back pressure of about 5 Bar to about 25 Bar, and any combination thereof.

In another example of the method of manufacturing an ophthalmic lens, the step of forming at least one of the first mold member and the second mold member using the at least one vinyl alcohol copolymer with high amorphous content comprises forming a molding surface on at least one of the first mold member and the second mold member using the at least one vinyl alcohol copolymer with high amorphous content; the non-molding region of at least one of the first mold member and the second mold member is formed from a second material, and wherein the step of placing a polymerizable composition into the first mold member or the second mold member comprises placing a polymerizable composition in direct contact with a molding surface comprising the at least one vinyl alcohol copolymer with high amorphous content. In other words, the at least one vinyl alcohol copolymer can be used to form a molding surface of a mold, and one or more other polymers can be used to form a non-molding surface of the mold.

In another example of the method of manufacturing an ophthalmic lens, the lens body has ophthalmically acceptably wettable front and back surfaces, no surface treatment is applied to the lens body, or no components are present in the polymerizable composition that can form an interpenetrating network (IPN) of wetting agent in the lens body during curing.

In another example of the method of manufacturing an ophthalmic lens, the method further comprises the step of separating the first mold member and the second mold member. The step of separating the first mold member from the second mold member can include a wet demolding step wherein the lens remains in contact with only one of the two mold members at the end of the step; or a simultaneous wet demolding and wet delensing step, wherein a lens is released from both the first mold member and the second mold member at the end of said step. In one example, when the separating holds the lens body in contact with one and only one of the first mold member and the second mold member, the one and only one of the first mold member and the second mold member is at least one of the first mold member and the second mold member comprising the at least one vinyl alcohol copolymer with high amorphous content. In other words, the step of separating the first mold member and the second mold member can maintain the lens in contact with the mold member comprising the at least one vinyl alcohol copolymer with high amorphous content.

In another example, the step of separating the cured mold assembly comprises applying a liquid to at least one of the first mold member and the second mold member comprising the at least one vinyl alcohol copolymer with high amorphous content, thereby at least partially dissolving at least one of the first mold member and the second mold member comprising the at least one vinyl alcohol copolymer with high amorphous content in the liquid. In other words, the lens can be separated from the mold member by applying a liquid to the mold member comprising the at least one vinyl alcohol copolymer with high amorphous content and dissolving the mold member in the liquid. The step of applying a liquid may further comprise agitating the liquid, or agitating at least one of the first mold member and the second mold member comprising the at least one vinyl alcohol copolymer with high amorphous content. Dissolving at least one of the first mold member and the second mold member comprising the at least one vinyl alcohol copolymer with high amorphous content may be conducted at a temperature of about 70 ℃ or below 70 ℃, and at least one of the first mold member and the second mold member comprising the at least one vinyl alcohol copolymer with high amorphous content may be completely dissolved in less than about 240 minutes. The mold member comprising the at least one vinyl alcohol copolymer with high amorphous content may be completely dissolved in less than about 180 minutes, less than about 120 minutes, less than about 60 minutes, or less than about 30 minutes. In one example, dissolving at least one of the first mold member and the second mold member comprising the at least one vinyl alcohol copolymer with high amorphous content does not produce a foam, cloudy solution, gel, or combination thereof that would disrupt the manufacturing process. In other words, dissolution may produce lower levels of foam, cloudy solution, gel, or a combination thereof, without disrupting the manufacturing process.

In another example of the method of manufacturing an ophthalmic lens, the method further comprises the step of washing the released lens body to produce a washed lens body. The liquid used in the washing step may comprise an organic solvent, an aqueous solution of an organic solvent, water or an aqueous solution substantially free of an organic solvent, including an aqueous solution substantially free of a volatile alcohol, such as an aqueous salt solution or an aqueous surfactant solution.

In another example of the method of manufacturing an ophthalmic lens, the method further comprises the step of placing a mold assembly comprising a cured lens body in a lens-shaped cavity into a blister package with a packaging solution, and sealing and sterilizing the package, wherein the mold assembly is completely dissolved in the packaging solution after sterilization.

In another example of the method of manufacturing an ophthalmic lens, wherein the molding surface of at least one of the first mold member and the second mold member comprises the at least one vinyl alcohol copolymer with high amorphous content, and the non-molding region of the at least one first mold member or second mold member is formed from at least one polymeric material that is insoluble in a packaging solution and is configured to be used as a blister package.

In another example, the present invention is directed to a silicone hydrogel contact lens body comprising: a cast-molded polymeric lens body comprising the reaction product of a polymerizable composition comprising at least one silicone monomer, silicone macromer, silicone prepolymer, or any combination thereof, and at least one hydrophilic monomer; wherein the lens body is cast molded in a mold assembly comprising a first mold member and a second mold member, at least one of the first mold member and the second mold member comprising at least one vinyl alcohol copolymer with high amorphous content.

In another example, the present invention is directed to a packaged silicone hydrogel contact lens body comprising: a blister package formed from a hydrophobic polymeric material; a cast-molded polymeric lens body comprising a reaction product of a polymerizable composition comprising at least one silicone monomer, silicone macromer, silicone prepolymer, or any combination thereof, and at least one hydrophilic monomer; and a liquid comprising a dissolution product of at least one vinyl alcohol copolymer having a high amorphous content in a packaging solution.

In another example, the present invention is directed to a mold member for cast molding a silicone hydrogel contact lens body, comprising: a mold member comprising a molding surface and a non-molding region, wherein at least the molding surface of the mold member comprises at least one vinyl alcohol copolymer with high amorphous content.

Any and all features described herein, as well as any combination of such features, are included within the scope of the present application so long as the features in any such combination are not mutually inconsistent. Furthermore, any feature or combination of features may be specifically excluded from any example of the present invention.

Drawings

Fig. 1 is a flow chart illustrating the steps of a method for manufacturing an ophthalmic lens.

Fig. 2 is a flow chart illustrating certain inputs and outputs of the method of fig. 1.

Detailed Description

It has been found that ophthalmic lens molds made from vinyl alcohol copolymers having high amorphous content can be used to cast mold ophthalmic lens bodies. Ophthalmic lenses can be demolded, delensed, or demolded and delensed from molds made partially or completely from one or more vinyl alcohol copolymers having high amorphous content using "wet" demolding, delensed, or demolded and delensed methods (i.e., methods involving the application of a liquid to a lens body and a mold assembly or mold member). Ophthalmic lenses can also be demolded, delensed, or demolded and delensed using "dry" demolding, delensed, or demolded and delensed methods (i.e., methods that do not involve the application of a liquid to the lens body and the mold assembly or mold member). Unlike molds made from materials with poor water solubility, molds made from at least one vinyl alcohol copolymer with high amorphous content can be used to make lens bodies that can be demolded, delensed, or both demolded and delensed by partially or completely dissolving the vinyl alcohol copolymer with high amorphous content in water or an aqueous solution. Unlike molds made from pure PVOH, molds made from vinyl alcohol with high amorphous content can be formed by injection molding, or can be formed by compression molding, continuous compression molding, thermoforming, and the like. Unlike molds made from modified forms of PVOH, molds made from at least one vinyl alcohol copolymer having a high amorphous content can be rapidly and completely dissolved in liquids (including water and aqueous solutions) such as water and aqueous solutions at low temperatures, and solutions of the at least one vinyl alcohol copolymer formed by dissolving the molds in the liquid do not present manufacturing difficulties, such as excessive foaming, gelling of the liquid, or the liquid becoming cloudy due to the dissolved vinyl alcohol copolymer. Further, molding silicone hydrogel contact lenses using these molds made from at least one vinyl alcohol copolymer with high amorphous content can produce lens bodies with ophthalmically acceptably wettable surfaces, without applying a surface treatment to the lens surfaces, and without the presence of components in the polymerizable composition that can form an interpenetrating network (IPN) of a polymeric wetting agent in the lens body.

As used herein, a vinyl alcohol copolymer is a polymer comprising vinyl alcohol units and monomer units other than vinyl alcohol. It is different from a vinyl alcohol homopolymer (a polymer comprising only vinyl alcohol repeat units), i.e., poly (vinyl alcohol) (PVOH), or a modified form of PVOH, such as a form of PVOH combined with ingredients (e.g., plasticizers) that enable the PVOH to be injection molded. The vinyl alcohol copolymer with high amorphous content can comprise a vinyl alcohol copolymer with high vinyl alcohol content or with low vinyl alcohol content. The vinyl alcohol copolymer can comprise a percentage of vinyl alcohol units in the polymer chain of greater than or equal to about 95%, greater than or equal to about 90%, greater than or equal to about 85%, greater than or equal to about 80%, greater than or equal to about 75%, greater than or equal to about 70%, greater than or equal to about 65%, greater than or equal to about 60%, greater than or equal to about 55%, greater than or equal to about 50%, greater than or equal to about 45%, greater than or equal to about 40%, greater than or equal to about 35%, greater than or equal to about 30%, greater than or equal to about 25%, greater than or equal to about 20%, greater than or equal to about 15%, greater than or equal to about 10%, greater than or equal to about 5%, or less than or equal to about 5%. The percentage of vinyl alcohol units in the polymer chain can be expressed in weight percent or in mole percent.

The vinyl alcohol copolymer having a high amorphous content may be a vinyl alcohol copolymer other than an ethylene-vinyl alcohol copolymer (i.e., a copolymer comprising ethylene units and vinyl alcohol units). The vinyl alcohol copolymer having a high amorphous content can be a vinyl alcohol copolymer substantially free of ethylene units.

The vinyl alcohol copolymer with high amorphous content can be a polymer composed of three or more different monomer units, wherein one monomer unit (e.g., the first unit) comprises vinyl alcohol. In one example of a terpolymer, the first monomer unit may comprise vinyl alcohol, the second and third monomer units may comprise monomer units other than ethylene or vinyl alcohol, or one monomer unit (e.g., the second monomer unit) may comprise ethylene, when the other monomer unit (e.g., the third) does not comprise ethylene or vinyl alcohol.

The term "vinyl alcohol copolymer having a high amorphous content" refers to a vinyl alcohol copolymer containing a large number of amorphous regions and thus containing less crystalline regions (i.e., less three-dimensionally ordered regions on an atomic length scale). In polymers, crystalline regions may result from intramolecular folding of the polymer, from stacking of adjacent polymer chains, or from both. The polymer may contain crystalline regions and amorphous regions. Crystallinity is generally used to describe the crystalline content of a given polymer, where a crystallinity of 0 indicates a completely amorphous (noncrystalline) polymer and a crystallinity of 1 indicates a completely crystalline polymer. The crystalline content may also be expressed as a percentage, where an average level of crystallinity of 0% indicates a completely amorphous polymer and an average level of crystallinity of 100% indicates a completely crystalline polymer. The degree or level of crystallinity can be determined using Differential Scanning Calorimetry (DSC). The degree or level of crystallinity can be determined using DSC by heating a polymer sample from 0 ℃ to 250 ℃ at a heating rate of 10 ℃/minute and determining the degree or level of crystallinity based on the first cooling and heating cycle performed on the polymer sample. As used herein, a vinyl alcohol copolymer having a high amorphous content is understood to be a vinyl alcohol copolymer having an average level of crystallinity from about 0% to about 35%, including, for example, a vinyl alcohol copolymer having an average level of crystallinity less than or equal to about 30%, less than or equal to about 25%, less than or equal to about 20%, from about 10% to about 30%, from about 15% to about 25%, or from about 17% to about 20%.

The vinyl alcohol copolymer having a high amorphous content can be a thermoplastic vinyl alcohol copolymer, i.e., a vinyl alcohol copolymer that becomes liquid or malleable when heated and freezes to a glassy state when sufficiently cooled, and which can be repeatedly remelted and remolded.

The vinyl alcohol copolymer having a high amorphous content can be an extrudable vinyl alcohol copolymer, i.e., a vinyl alcohol copolymer that can be processed by pushing or pulling the copolymer through a die to form an object having a desired shape.

The vinyl alcohol copolymer having a high amorphous content can be a vinyl alcohol copolymer suitable for injection molding, i.e., a vinyl alcohol copolymer that can be processed by heating the copolymer to a fluid state and injecting it into a mold to form an object having a desired shape. The melting point of the vinyl alcohol copolymer suitable for injection molding can be below its decomposition temperature. For example, the melting point may be more than about 20 ℃, more than about 40 ℃, more than about 60 ℃, more than about 80 ℃, or more than about 100 ℃ below the decomposition temperature of the copolymer. In one example, the decomposition temperature of the vinyl alcohol copolymer is about 300 ℃.

In one example, the melting point of the vinyl alcohol copolymer can be from about 140 ℃ to about 190 ℃, from about 155 ℃ to about 180 ℃, from about 160 ℃ to about 172 ℃, or from about 150 ℃ to about 230 ℃. In another example, the glass transition temperature of the vinyl alcohol copolymer can be from about 60 ℃ to about 85 ℃, from about 65 ℃ to about 80 ℃, or from about 70 ℃ to about 76 ℃.

The vinyl alcohol copolymers having a high amorphous content are soluble in water and aqueous solutions. The vinyl alcohol copolymer dissolves rapidly in water and aqueous solutions. The vinyl alcohol copolymer can be dissolved in water and aqueous solutions without leaving a residue detectable to the naked eye. In one example, the vinyl alcohol copolymer can be dissolved in water at a temperature of about 30 ℃ to about 80 ℃ in less than about 20 minutes to form a 6% vinyl alcohol copolymer solution.

Vinyl alcohol copolymers with high amorphous content, while having good water solubility, can be practically insoluble in ethyl acetate, benzene, and toluene.

In a specific example, the vinyl alcohol copolymer having a high amorphous content is NichigoG-Polymer manufactured by Nippon synthetic chemical industries, Ltd, Osaka, Japan^TM。

Vinyl alcohol copolymers having high amorphous content are useful for cast molding various types of polymerizable lens-forming compositions. The polymerizable composition may comprise at least one hydrophilic monomer. The polymerizable composition can further comprise at least one crosslinker, at least one initiator, at least one colorant, at least one UV blocker, and any combination thereof. The at least one initiator may comprise at least one UV initiator or at least one thermal initiator. In one example, the hydrophilic monomer can comprise a silicone-free monomer, such as 2-hydroxyethyl methacrylate (HEMA).

The polymerizable lens-forming composition can be a silicone hydrogel polymerizable composition. The silicone hydrogel polymerizable composition can comprise a) at least one silicone monomer, at least one silicone macromer, at least one silicone prepolymer, or a combination thereof, and b) at least one hydrophilic monomer. In one example of a silicone hydrogel polymerizable composition, the hydrophilic monomer can comprise a hydrophilic monomer having an N-vinyl group. In another example, the silicone hydrogel polymerizable composition can further comprise a silicone oil form. In another example, the silicone hydrogel polymerizable composition may comprise a camifacien a (comfilcon a) polymerizable composition, and the polymerized reaction product is a camifacien a lens body.

As previously discussed, vinyl alcohol copolymers having high amorphous content can be used to form at least one mold member for molding an ophthalmic lens. The mold member can be manufactured by conventional injection molding procedures known to those skilled in the art. For example, some vinyl alcohol copolymers can be heated to form a molten thermoplastic polymer. The molten thermoplastic polymer can be dispensed into a mold cavity in the shape of an ophthalmic lens mold. For example, the mold cavity may include one or two optical quality molding surfaces. The optical quality molding surface may be provided as a component of one or more removable inserts located in a flat plate or other housing, or may undergo integral machining as part of the molding cavity. The molten thermoplastic polymer in the mold cavity can then be cooled and separated from the molding machine, and then moved to a position to receive a volume of polymerizable composition for use in forming an ophthalmic lens.

Process settings for injection molding a vinyl alcohol copolymer with high amorphous content may include:

a melt temperature of about 180 ℃ to about 250 ℃

Barrel temperature of about 180 ℃ to about 250 ℃

A crown temperature of about 30 ℃ to about 70 ℃

A mold tool temperature of about 30 ℃ to about 95 ℃

A hold time of about 1 second to about 5 seconds

An ejection speed of about 50 mm/s to about 250 mm/s

Plasticizing speed of about 100 mm/s to about 300 mm/s

An injection pressure of about 50 bar to about 180 bar

A holding pressure of about 10 bar to about 200 bar

A back pressure of about 5 bar to about 25 bar.

In one example, at least two of these process settings are used to injection mold the vinyl alcohol copolymer. In another example, three, four, five, six, seven, eight, nine, ten, or all of these process settings are used to injection mold the vinyl alcohol copolymer.

Alternatively, the at least one mold member can be manufactured by a combination of injection molding and machining, lathing or cutting, for example, wherein the basic shape of the mold member is prepared by injection molding and a portion of the mold member is removed, for example by machining, lathing or cutting a portion of the mold member, thereby preparing all or a portion of the molding surface of optical quality, for example, all or a portion of the mold area for molding the optical zone of the contact lens.

In another example, a vinyl alcohol copolymer having a high amorphous content can be used to form at least one molding surface of a mold member, wherein at least some of the non-molding portions of the mold member are formed from a material other than a vinyl alcohol copolymer. In one example, the non-molding portion of the mold member can be formed of a material (e.g., a metal or polymeric material) that is substantially insoluble in water or aqueous solutions. In one example, the non-molding portion can include a frame or support for a molding surface comprising the vinyl alcohol copolymer. The vinyl alcohol copolymer can be used to form the entire molding surface, or can be used to form a portion of the molding surface, such as a layer of a multi-layer molding surface, where the vinyl alcohol copolymer layer is the portion or layer of the multi-layer molding surface that directly contacts the polymerizable composition during cast molding. The portion or layer of the molding surface comprising the vinyl alcohol copolymer can be formed using various methods such as injection molding or film casting.

Vinyl alcohol copolymers with high amorphous content can be used to form molds configured to cast mold ophthalmic devices. Ophthalmic devices can include contact lenses, including silicone hydrogel contact lenses. When silicone hydrogel contact lenses are cast molded using vinyl alcohol copolymers, the surface of the lens body molded using the vinyl alcohol copolymer can be an ophthalmically acceptably wettable molding surface, no surface treatment is applied to the lens body, or no component is present in the polymerizable composition used to form the lens body that can form an interpenetrating network (IPN) of a wetting agent in the lens body during curing of the lens body.

As used herein, "ophthalmically compatible silicone hydrogel contact lenses" refers to silicone hydrogel contact lenses that can be worn on the eye of a person without the person experiencing or reporting significant discomfort, including ocular irritation, and the like. These lenses often have oxygen permeability, surface wettability, modulus (modulius), water content, ion flux (ionofiux), design, and any combination thereof that allows the lens to be comfortably worn on a patient's eye for extended periods of time, such as at least one day, at least one week, at least two weeks, or about one month, without removing the lens from the eye. Generally, ophthalmically compatible silicone hydrogel contact lenses do not cause or are not associated with the following: significant corneal edema, corneal dehydration ("dry eye"), superior epithelial arch damage ("SEAL"), or other significant discomfort. Ophthalmically compatible silicone hydrogel contact lenses meet the clinical acceptability requirements for daily or extended wear contact lenses.

Ophthalmically compatible silicone hydrogel contact lenses have ophthalmically acceptably wettable surfaces, although lenses having ophthalmically acceptable wettable surfaces need not be ophthalmically compatible. A silicone hydrogel contact lens having an "ophthalmically acceptably wettable surface" can be understood to refer to a silicone hydrogel contact lens that does not adversely affect the tear film of the lens wearer's eye to a degree that the lens wearer experiences or reports discomfort associated with placing or wearing the silicone hydrogel contact lens on the eye.

An ophthalmic lens includes a lens body having surfaces, such as an anterior surface and a posterior surface. As used herein, an ophthalmically acceptably wettable ophthalmic lens is a lens body having surfaces all having ophthalmically acceptable wettability. Wettability refers to the hydrophilicity of one or more surfaces of the lens. As used herein, a surface of a lens can be considered to have an ophthalmically acceptable wettability if the lens has a score of 3 or more than 3 in a wettability analysis performed as follows. Ophthalmic lenses were immersed in distilled water, removed from the water, and the length of time it took for the water film to fall off the lens surface (e.g., water film break time (WBUT)) was determined. The analysis ranks the lenses on a linear scale from 1 to 10, where 10 points to a lens where a droplet takes 20 seconds or more to fall from the lens. Lenses with WBUTs in excess of 5 seconds (e.g., at least 10 seconds or more desirably at least about 15 seconds) can be ophthalmically acceptably wettable lenses. Wettability can also be determined by measuring the contact angle on one or both lens surfaces. The contact angle may be a dynamic or static contact angle, a sessile drop contact angle, a hanging drop contact angle, or a captive bubble (captivebubble) contact angle. A smaller contact angle generally means a higher wettability of the contact lens surface. For example, an ophthalmically acceptably wettable lens surface can have a contact angle of less than about 120 degrees. However, in certain examples, the contact angle of the lens is no greater than about 90 degrees, and in other examples, the advancing contact angle of the lens is less than about 80 degrees.

As described herein, an ophthalmic lens cast molded using a vinyl alcohol copolymer with high amorphous content can have an ophthalmically acceptably wettable surface when fully hydrated, and can provide an ophthalmically acceptably wettable surface without the need to apply a surface treatment or the presence of an interpenetrating network of polymeric wetting agent in the lens body. However, applying a surface treatment to the lens or the presence of an interpenetrating network of a polymeric wetting agent in the lens body can be used to further increase the wettability of the lens surface beyond what is considered ophthalmically acceptable wettability.

One measure of the ability of a mold member to mold a silicone hydrogel contact lens having an ophthalmically acceptable wettable surface is the contact angle of the mold member. The contact angle may include a dynamic or static contact angle, a sessile drop contact angle, a hanging drop contact angle, or a captive bubble contact angle. In one example, the contact angle may be measured using a bubble trap method, and may be performed in pure water using a contact angle tester, such as a CA-DT type or a KrussDSA100 instrument (hamburger gmbh, Hamburg) manufactured by kyowa kaimen kagakuco. The measurement can be carried out at 25 ℃.

The process of cast molding contact lens bodies, including silicone hydrogel contact lens bodies, typically begins with the preparation of a pair of mold members (i.e., a first mold member and a second mold member). The mold member can be made by injection molding a thermoplastic polymer mold material in a mold cavity, by lathing the polymer mold material to form the entire mold member, or by a combination of injection molding and lathing, such as injection molding to form the basic shape of the mold member, followed by lathing all or a portion of the lens forming area of the mold member.

Typically, two mold members are combined to cast mold a contact lens body. The two mold members are sized and structured to be assembled together to define a lens-forming cavity therebetween. The two mold members can each include a concave lens-forming surface for molding the anterior surface of the optic or a convex lens-forming surface for molding the posterior surface of the optic. For the purposes of the present invention, a mold part having a concave lens-forming surface is referred to as a first mold part or female mold part, while a mold part having a convex lens-forming surface is referred to as a second mold part or male mold part. The first and second mold members can be structured to form a lens-shaped cavity therebetween when assembled with one another to form a mold assembly. Alternative mold member configurations, such as mold assemblies comprising more than two mold members or mold members having shapes or structures different from those described above, may be used with the vinyl alcohol copolymers described herein having high amorphous content. In addition, these mold members can be configured to include more than one lens forming area. For example, a single mold member can be configured to include an area configured to mold a lens front surface as well as a lens back surface, i.e., to act as a female or male mold member.

As previously discussed, when vinyl alcohol copolymer having high amorphous content is used to manufacture mold members configured as mold assemblies to form lens-shaped cavities therebetween, the process of assembling the mold members into a mold assembly can further include the step of forming some connection between the mold members. The first mold member and the second mold member can be structured to be easily separated after assembly together, preferably without substantial damage to at least one of the first and second mold members and the ophthalmic lens product being manufactured in the lens-shaped cavity. In one example, the mold members may be configured to form a mechanical connection based on the shape of the elements in the mold members, such as an interference fit (interference fit) between the mold members, threads between the mold members, bores and protrusions between the mold members, or other locking structures. In another example, a weld may be formed between mold members by melting a region of one or more mold members to bond the mold members to one another. In another example, a bonding substance, such as in the form of a glue, contact cement (sealant), or sealant, may be used to form a bond between the mold parts. In another example, additional elements, such as clips, clamps, or brackets, may be used to join the mold parts together. Regardless of the type of connection used between the mold parts, the connection is intended to keep the mold parts aligned during the curing process and needs to be releasable prior to or as part of the demolding process.

During the process of manufacturing the lens body, the polymerizable composition that forms the lens is filled into the mold members prior to combining the individual mold members to form the mold assembly. Typically, this is accomplished by placing a predetermined amount of the polymerizable composition onto one mold member, such as placing the polymerizable composition into the concave molding surface of the first mold member. The mold assembly is then assembled by placing the other mold member in contact with a mold member having a polymerizable composition, such as by placing the convex molding surface of the second mold member in contact with the first mold member, such that a lens-shaped cavity is formed between the first mold member and the second mold member, the lens-shaped cavity containing the polymerizable composition. If used, a connection is made between the first and second mold members by any available means in order to maintain the mold members in proper alignment during the curing process. As previously described, the process of forming the connection may include, for example, welding the mold parts together, gluing the mold parts together, applying pressure to the mold parts to engage an interference fit, threading the mold parts together, applying a clamp to the mold parts, and the like.

The mold assembly, which comprises a first mold member and a second mold member and comprises a polymerizable composition in the lens-shaped cavity, is then cured. The polymerizable composition is cured in the lens-shaped cavity to form a polymerized reaction product, i.e., a lens body, in the shape of the lens-shaped cavity. Curing typically involves applying a form of electromagnetic radiation to a mold assembly comprising the polymerizable composition so as to polymerize the polymerizable composition in a lens-shaped cavity of the mold assembly. Forms of electromagnetic radiation may include thermal radiation, visible light, Ultraviolet (UV) light, and the like. Any combination of two or more forms of electromagnetic radiation, as well as two or more levels of one or more forms of electromagnetic radiation, may be used to cure the mold assembly. The curing method is generally matched to the type of initiator used in the polymerizable composition, i.e., a polymerizable composition comprising a UV initiator is typically cured using UV light, while a polymerizable composition comprising a thermal initiator is typically cured using thermal radiation and is typically at a temperature above the initiation temperature of the thermal initiator. Regardless of the curing method used, the temperature may be maintained at a temperature below the melting point of the vinyl alcohol copolymer or below the glass transition temperature of the vinyl alcohol copolymer during the curing process. The curing process typically involves curing the mold assembly until the polymerizable composition has polymerized sufficiently that the lens body will retain the shape of the lens-shaped cavity after demolding and delensing. Thus, the curing process may not cause complete reaction of all polymerizable components in the polymerizable composition.

As used herein, "demolding" refers to the process of separating the mold members of a mold assembly after the polymerizable composition has cured. As a result of the demolding process, the two mold members are separated from each other, and the lens body remains in contact with (i.e., attached to or adhered to) one and only one of the mold members used to cast mold the lens body.

The dry demolding process involves separating the mold members of the mold assembly using a mechanical process after curing. In a dry demolding process, the mold assembly comprising the polymerized lens body is not in contact with a liquid, such as an organic solvent, water, or aqueous solution, during the demolding process, and typically, the mold assembly comprising the polymerized lens body is not exposed to the liquid prior to the dry demolding process. After the dry demolding process, the polymerized lens body remains in contact with one and only one of the mold members used to mold the lens body. In one example, a dry demolding process can include pressing one or more mold members to deform the mold members and separating the mold members, leaving the polymerized lens body in contact with one mold member. If the mold members of the mold assembly are held together at least in part by an interference fit between the mold members, the dry demolding process may include applying pressure to one or more mold members in order to push the mold members away from each other to break the interference fit. Dry demolding may include penetrating the material of the weld if the mold members of the mold assembly are held together at least in part by the weld between the mold members.

The wet demolding process involves applying a liquid to separate the mold members of the mold assembly after curing. In a wet demolding process, a mold assembly comprising a polymerized lens body is contacted with a liquid, such as an organic solvent, water, or aqueous solution, during a demolding process. After the wet demolding process, the polymerized lens body can remain in contact with one and only one of the mold members used to mold the lens body, or can be released from both mold members used to mold the lens body. Wet demolding processes, in addition to including applying a liquid to the mold assembly, may also include separating the mold members using mechanical methods, including pressing one or more mold members to deform the mold members, applying pressure to one or more mold members so as to push the mold members away from each other to break an interference fit, or penetrating a weld or adhesive holding the mold assembly together.

As part of a wet or dry demolding process, it may be desirable for the lens body to remain in contact with a particular mold member, such as the first or second mold member, after the demolding process. To help the lens body remain in contact with the desired mold part, heat may be applied to the first or second mold part, for example, by blowing hot air on the back side of the mold part. Alternatively, the first or second mould part may be cooled, for example by blowing cold air or applying a cooled liquid to one mould part on the back side of the mould part. Applying pressure to the first or second mold member prior to demolding or concurrently with the demolding process may also help the lens body remain in contact with the particular mold member (i.e., the first or second mold member) after the demolding process.

As used herein, "delensing" refers to a process of releasing a lens body from one mold member with which the lens body remains in contact after the mold members of the mold assembly have been separated in a demolding process.

The dry delensing process involves the use of a mechanical process to release the lens body from one of the remaining mold members with which the lens body is in contact after the demolding step. In a dry delensing process, the lens body and a remaining mold part with which the lens body is in contact are not contacted with a liquid, such as water or an aqueous solution, as part of the delensing process. While it is possible to use a wet demolding process (involving application of a liquid to a mold assembly comprising a polymeric lens body) prior to a dry delensing process, it is more common to use a dry demolding process prior to a dry delensing process. When a dry demolding process is used with a dry delensing process, the lens body is not exposed to a liquid such as an organic solvent, water, or aqueous solution before the lens body is released from both mold members of the mold assembly (i.e., from both the first and second mold members). In one example, a dry delensing process may involve the use of vacuum equipment to lift the polymerized lens body from one of the remaining mold members with which it is in contact after the demolding step. The dry delensing process may also involve pressing the one remaining mold member to at least partially break the bond between the one mold member and the lens body. The dry delensing process can involve inserting a pry tool between the edge of the lens body and the mold member to at least partially break the bond between the lens body and the mold member.

Wet delensing processes involve the application of a liquid, such as an organic solvent, water or aqueous solution, to release the lens body from one of the remaining mold members with which the lens body is contacted after the demolding step. After or while applying the liquid, the wet delensing process further comprises using a vacuum apparatus to lift the polymerized lens body from one of the remaining mold members with which it was in contact after the demolding step. The wet delensing process can also optionally involve the use of mechanical means to assist in releasing the lens body, such as squeezing the one remaining mold member to at least partially break the bond between the one mold member, or inserting a pry tool between the lens body edge and the mold member to at least partially break the bond between the lens body and the mold member.

Because the mold members formed from the vinyl alcohol copolymer having a high amorphous content have high water solubility, a wet demolding process, a wet delensing process, or both wet delensing and demolding processes involving the application of a liquid to dissolve the vinyl alcohol copolymer mold member may be used. In these processes, the mold assembly, mold member, or molding surface comprising the cured lens body can be transferred to a tray prior to application of the liquid. The tray can include separate grooves sized and structured to receive the lens body after the mold assembly, mold member, or molding surface is dissolved by the liquid. For example, when the mold assembly used to mold the lens body is formed entirely of the vinyl alcohol copolymer, upon curing, the mold assembly comprising the cured lens body can be transferred to a tray. In another example, when the molding surface of the mold assembly is formed entirely of the vinyl alcohol copolymer and the non-molding portion of the mold assembly is formed of a material that is insoluble in the liquid, the non-molding portion of the mold assembly can be removed from the molding surface of the mold assembly and the molding surface of the mold assembly comprising the cured lens body can be transferred to a tray. In another example, after demolding, the mold member formed entirely of the vinyl alcohol copolymer and attached lens body can be transferred to a tray. In another example, after demolding, when the molding surface of the one and only one mold member is formed entirely of vinyl alcohol copolymer, the molding surface and attached lens body can be transferred to a tray.

The liquid applied in the wet demolding process, the wet delensing process, or both the wet demolding and delensing processes may comprise water or an aqueous solution. In one example, the aqueous solution can comprise an aqueous solution of a processing aid that can increase the dissolution rate of the vinyl alcohol copolymer. In another example, the processing aid can be a compound that assists in washing the lens body or in removing extractable material from the lens body. In another example, the processing aid can be a compound that helps protect the lens body from damage or deformation during processing, such as surfactants, including Tween80 (Tween 80).

The temperature of the liquid can be controlled immediately prior to, during, or after the step of applying the liquid, for example, to maintain the liquid at a temperature that increases the dissolution rate of the vinyl alcohol copolymer mold member.

During or after the step of applying the liquid, the liquid or the mold assembly or the mold member can be agitated, for example, to increase the dissolution rate of the vinyl alcohol copolymer mold member. In one particular example, ultrasonic energy can be applied to a liquid, a mold assembly, or a mold member.

For example, the liquid applied to the mold assembly (as part of a wet demolding process) or to the lens body and one mold member (as part of a wet delensing process) can be applied at a temperature of about 90 ℃ or less than 90 ℃, about 80 ℃ or less than 80 ℃, about 70 ℃ or less than 70 ℃, about 60 ℃ or less than 60 ℃, about 50 ℃ or less than 50 ℃, about 40 ℃ or less than 40 ℃, or about 30 ℃ or less than 30 ℃.

The application of the liquid can completely dissolve the one or more mold members comprising the vinyl alcohol copolymer in less than about 240 minutes, 180 minutes, 120 minutes, about 90 minutes, about 60 minutes, or about 30 minutes. Alternatively, application of the liquid can partially dissolve one or more mold members comprising the vinyl alcohol copolymer, wherein the partial dissolution of the one or more mold members is sufficient to separate the mold members of the mold assembly (i.e., demold the mold assembly), release the lens body from one mold member (i.e., delens the lens body), or both demold and delens (i.e., fully release the lens body from all of the mold members used to form it). For example, the application of the liquid may dissolve more than 10%, 25%, 50%, 75%, or 90% by weight or volume of the mold member.

As previously discussed, because vinyl alcohol copolymers with high amorphous content have excellent properties, the demolding, delensing, or demolding and delensing processes involving dissolution of vinyl alcohol copolymers with high amorphous regions are not severely affected by some of the problems experienced when other water-soluble polymers are dissolved in aqueous solutions. For example, PVOH, when dissolved in an aqueous solution, can produce substantial foaming, cause the solution to gel, produce a cloudy solution, or any combination of these problems. Since the presence of foam, gel or turbid solutions can disrupt the machining and manufacturing steps, additional measures and expense are required to control or eliminate these problems. Solutions of vinyl alcohol copolymers with high amorphous content produced as part of a wet release, delensing, or release and delensing process involving dissolving a mold member comprising the vinyl alcohol copolymer in water or an aqueous solution do not produce significant amounts of foam even when the liquid and mold member are agitated. In addition, the solution does not readily gel, making it possible to perform demolding, delensing, or both demolding and delensing processes in large tanks or baths where a single volume of liquid is applied to a plurality of lenses and mold members. Since the solution does not gel under these conditions, it can be easily emptied from the tank or bath and refilled with fresh or recycled liquid. Since the solution of the vinyl alcohol copolymer with high amorphous content in the liquid remains clear, the lens body and the mold member can be observed manually or using an automated system to determine whether the lens body has been released from the mold member, or whether the mold member has dissolved.

Depending on the type of lens body and the demolding/delensing process used, after demolding and delensing, the lens body may undergo one or more washing steps, including washing steps conducted in an organic solvent, an aqueous solution of an organic solvent, water, or an aqueous solution substantially free of an organic solvent. The washing step can be used to clean dust or debris from the lens body, extract material from the lens body, or hydrate the lens body. For example, a washing step can be used to remove the diluent from the lens body; removing unreacted or partially reacted monomer, macromer or prepolymer from the lens body; or to increase the wettability of the lens body.

In one example, the wash solution may comprise an organic solvent or an aqueous solution of an organic solvent. The organic solvent may comprise a volatile organic solvent, such as a volatile alcohol. Examples of volatile alcohols include methanol, ethanol, propanol, and the like.

In another example, the wash solution can comprise water or an aqueous solution substantially free of organic solvents. The substantially organic solvent-free aqueous solution used to wash the lenses of the invention may include saline solutions, buffer solutions, surfactant solutions, wetting agent solutions, conditioner (comfortagent) solutions, any combination thereof, and the like. In one example, the lenses of the invention can be washed with one or more polymeric wetting agents or care agents. However, it is to be understood that the lenses of the invention may have ophthalmically acceptably wettable surfaces when washed in aqueous solutions that do not contain any polymeric wetting or conditioning agents. Thus, while polymeric wetting agents or conditioning agents may be used to increase the wettability of these lenses, their wettability is not solely dependent on the use of these agents.

After the lens body is released from the mold member and one or more optional washing steps (if used), the lens body can be placed into a blister package along with a portion of the packaging solution. In one example, the blister package may comprise a hydrophobic polymer. The blister package may then be sealed and sterilized, for example, by autoclaving the package under conditions suitable for sterilizing the package. Alternatively, due to the higher solubility level of the vinyl alcohol copolymer with high amorphous content, the lens body and the mold member or molding surface comprising the vinyl alcohol copolymer with high amorphous content can be placed directly into a blister package with a portion of the solution (without demolding, delensing, or both demolding and delensing the lens body prior to placing it into the blister package), and the mold member or molding surface comprising the vinyl alcohol copolymer is dissolved in the packaging solution during or after the manufacturing process.

In one example, when both the first and second mold members are formed entirely of vinyl alcohol copolymer with high amorphous content, after curing, the mold assembly including the cured lens body can be placed into a blister package with a portion of the solution, dissolving the mold members of the mold assembly and avoiding the need to perform separate demolding, delensing and lens transfer processes. In another example, when the molding surfaces of both the first mold member and the second mold member are formed entirely of vinyl alcohol with a high amorphous content, upon curing, the non-molding portion of the mold member can be removed from the mold assembly, and the molding surface and lens body can be placed into a blister package along with a portion of the solution, thereby dissolving the molding surface and avoiding the need for separate demolding, delensing and lens transfer processes. In another example, when one and only one of the first and second mold members to which the lens body remains attached after demolding is formed entirely of the vinyl alcohol copolymer, the one and only one mold member and attached lens body can be placed into a blister package along with a portion of the solution after curing and demolding, dissolving the one and only one mold member and avoiding the need to perform separate delensing and lens transfer processes. In another example, when the molding surface of one and only one of the first and second mold members to which the lens body remains attached after demolding comprises a molding surface formed entirely of the vinyl alcohol copolymer, upon curing, demolding and removing the non-molding portion of the mold member, the molding surface and attached lens body can be placed into a blister package along with a portion of the solution, dissolving the molding surface and avoiding the need to perform separate delensing and lens transfer processes.

The mold member or molding surface comprising the vinyl alcohol copolymer may be dissolved in the portion of the packaging solution prior to sealing the blister package, after sealing the blister package, prior to autoclaving the blister package, or after autoclaving the blister package. For example, less than about 15%, less than about 10%, less than about 5%, or less than about 1% by weight of the vinyl alcohol copolymer with high amorphous content added to the blister package may remain undissolved in the blister package before sealing the blister package, after sealing the blister package, before autoclaving the blister package, or after autoclaving the blister package.

A device may be used to increase the volume of packaging solution used to dissolve a mold part or molding surface, such as the device described in U.S. patent application No. 61/313,524, which is incorporated herein by reference in its entirety. Alternatively, the lens body and the mold member or molding surface can be placed into a blister package along with a portion of the wash solution that is replaced with the packaging solution prior to sealing the blister package. Again, a device such as that described in U.S. patent application No. 61/313,524 may be used for this purpose.

In one example, when the molding surface of the mold member is formed entirely of the vinyl alcohol copolymer with high amorphous content and the non-molding portion of the mold member is formed of a polymer that is insoluble in water and in the packaging solution, the non-molding portion of the mold member can be structured to additionally serve as a blister package. For example, the non-molding portion of the mold member can be formed from a hydrophobic polymer (e.g., polypropylene). The non-molding portion of the mold member can be structured to further include a cavity to retain a liquid and a flange extending outwardly from the cavity. In another example, the non-molding portion of the mold member can be configured to be used as a blister package configured to allow optical inspection of a lens placed in the blister package. The non-molding portion of the mold member can be structured to include a cavity to retain liquid, a flange extending outwardly from the cavity, and a bottom wall surface configured to collimate light. Blister packages configured to allow optical inspection of lenses placed in the blister package are described in U.S. Pat. No. 7,477,366, which is incorporated herein by reference in its entirety.

In examples where the molding surface of the mold member is formed entirely of a vinyl alcohol copolymer having a high amorphous content and the non-molding portion of the mold member is configured to be used as a blister package, a method of manufacturing an ophthalmic lens can include the step of demolding the mold assembly such that the lens body remains in contact with the mold member configured to be used as a blister package. The process can then include adding a packaging solution into a chamber of the blister package to dissolve the molding surface formed by the vinyl alcohol copolymer and release the lens body from the molding surface. The lens in the blister package may then be optically inspected prior to sealing and sterilizing the blister package.

In examples where the mold member or molding surface formed from the vinyl alcohol copolymer with high amorphous content is dissolved in a packaging solution sealed in a blister package with a lens body, the vinyl alcohol copolymer with high amorphous content may comprise ophthalmically acceptable ingredients present in the packaging solution. In one example, the vinyl alcohol copolymer with high amorphous content, when dissolved in a packaging solution, can further serve as a wetting agent, a care agent, an agent to prevent sticking of the lens body to the blister package, or any combination thereof.

In one example, a method of manufacturing an ophthalmic lens as described herein results in a higher yield of acceptable lens bodies than can be made using substantially the same method but using first and second mold members comprising an ethylene vinyl alcohol copolymer having a low amorphous content in place of at least one vinyl alcohol copolymer having a high amorphous content. The yield of acceptable lens bodies can be a yield of cosmetically acceptable lenses, or a yield of ophthalmically acceptable lenses. The yield of acceptable lenses can be that of lenses found to be free of visually detectable defects, as determined by manual visual inspection or by automated inspection using an automated inspection system. The yield of acceptable lens bodies can be the yield of acceptable lenses resulting from particular processing steps such as curing steps, demolding steps, delensing steps, washing steps, packaging steps, combinations of processing steps, and the like.

As used herein, the term "hydrogel" refers to a polymeric material, typically a network or matrix of polymer chains, that is capable of swelling in water or becoming swollen in the presence of water. A hydrogel is also understood to be a material that keeps water in an equilibrium state. The network or matrix may or may not be crosslinked. Hydrogels refer to water-swellable or water-swollen polymeric materials, including contact lenses. Thus, the hydrogel may be (i) unhydrated and water-swellable; or (ii) partially hydrated and water-swollen; or (iii) fully hydrated and water swollen. The hydrogel may be a silicone hydrogel, a silicone-free hydrogel, or a substantially silicone-free hydrogel.

The term "silicone hydrogel" or "silicone hydrogel material" refers to a particular hydrogel that includes a silicon (Si) -containing component or a Silicone (SiO) -containing component. For example, silicone hydrogels are typically prepared by combining a silicon-containing material with a conventional hydrophilic hydrogel precursor. Silicone hydrogel contact lenses are contact lenses, including vision correcting contact lenses, comprising a silicone hydrogel material.

A "silicone-containing" component is a component containing at least one [ -Si-O-Si- ] linkage in the form of a monomer, macromer or prepolymer, in which each silicon atom may optionally have one or more organo group substituents (R1, R2) or substituted organo group substituents in some manner, e.g., may optionally be chemically (e.g., covalently) bonded to one or more organo group substituents (R1, R2) or substituted organo group substituents, which may be the same or different, e.g., -SiR1R 2O-.

In the context of the polymers described herein, "molecular mass" refers to the nominal average molecular mass of the polymer as determined by size exclusion chromatography, light scattering techniques, or intrinsic viscometry in 1, 2, 4-trichlorobenzene. In the case of polymers, molecular weight may be expressed as a number average molecular weight or a weight average molecular weight, and in the case of vendor supplied materials will depend on the supplier. Typically, if the basis for any such molecular weight determination is not provided in the packaging material, it can be readily provided by the supplier. Generally, reference herein to the molecular weight of a monomer, macromer, prepolymer, or polymer herein refers to weight average molecular weight. The determination of both molecular weights (both number average and weight average) can be measured using gel permeation chromatography or other liquid chromatography techniques. Other methods of measuring molecular weight values may also be used, such as determining number average molecular weight using end group analysis or measuring colligative properties (e.g., freezing point depression, boiling point elevation, or osmotic pressure), or determining weight average molecular weight using light scattering techniques, ultracentrifugation, or viscometry.

The "network" or "matrix" of hydrophilic polymers generally means that crosslinks are formed between polymer chains by covalent bonds or by physical bonds such as hydrogen bonds. The network can include two or more polymer components and can include an interpenetrating network (IPN) in which one polymer is physically entangled with a second polymer such that a small number, if any, of covalent bonds are present therebetween, but the polymers cannot be separated from one another without disrupting the network.

"hydrophilic" substances are substances that are water-loving or have an affinity for water. Hydrophilic compounds have an affinity for water and are often charged or have polar moieties or groups that attract water.

As used herein, "hydrophilic polymer" is defined as a polymer that has an affinity for water and is capable of absorbing water. The hydrophilic polymer need not be soluble in water. The hydrophilic polymer is soluble in water, or insoluble (e.g., substantially insoluble) in water.

A "hydrophilic component" is a hydrophilic substance that may or may not be a polymer. Hydrophilic components include components that are capable of providing a water content of at least about 20% (w/w), such as at least about 25% (w/w), when combined with the remaining reactive components. The hydrophilic component may include a hydrophilic monomer, a hydrophilic macromer, a hydrophilic prepolymer, a hydrophilic polymer, or any combination thereof. Hydrophilic macromers, hydrophilic prepolymers and hydrophilic polymers are also understood to have hydrophilic and hydrophobic portions. Typically, the hydrophilic and hydrophobic portions are present in relative amounts such that the macromer, prepolymer, or polymer is hydrophilic.

"monomer" refers to a polymerizable compound of relatively low molecular weight, such as a compound having an average molecular weight of less than 700 daltons (Dalton). In one example, a monomer may comprise a single molecular unit containing one or more functional groups capable of polymerizing to form a polymer in combination with other molecules having the same structure or a different structure than the monomer.

"macromer" refers to medium and high molecular weight compounds or polymers, which may contain one or more functional groups capable of polymerization or further polymerization. For example, the macromer may be a compound or polymer having an average molecular weight of about 700 daltons to about 2,000 daltons.

"prepolymer" refers to a polymerizable or crosslinkable compound of relatively high molecular weight. As used herein, a prepolymer may contain one or more functional groups. In one example, the prepolymer may be a series of monomers or macromers that are bonded together such that the entire molecule remains polymerizable or crosslinkable. For example, the prepolymer can be a compound having an average molecular weight greater than about 2,000 daltons.

"Polymer" means a material formed by the polymerization of one or more monomers, macromers, prepolymers, or mixtures thereof. As used herein, a polymer is understood to mean a molecule that is not capable of polymerizing, but is capable of crosslinking with other polymers (e.g., other polymers present in the polymerizable composition or other polymers formed in the polymerizable composition during reaction of the monomers, macromers, and/or prepolymers).

"interpenetrating network" or "IPN" refers to a combination of two or more different polymers in the form of a network, at least one of which is synthesized (e.g., polymerized) and/or crosslinked in the presence of the other and which contains no or substantially no covalent bonds therebetween. IPNs may be composed of two types of chains that form two separate but juxtaposed or interpenetrating networks. Examples of IPNs include sequential IPNs, synchronous IPNs, semi-IPNs, and homogeneous IPNs (homo-IPNs).

"pseudo ipn (pseudoipn)" refers to a polymerization reaction product in which at least one of the different polymers is crosslinked and at least one other polymer is non-crosslinked (e.g., linear or branched), wherein the non-crosslinked polymer is molecularly distributed in and held by the crosslinked polymer such that the non-crosslinked polymer is substantially not extractable from the network.

By "polymer mixture" is meant a polymeric reaction product in which the different polymers are linear or branched and are not substantially crosslinked, wherein the resulting polymer blend is a mixture of polymers at the molecular level.

"graft polymer" refers to a branched polymer having side chains comprising a homopolymer or copolymer different from the backbone.

Unless otherwise specified, "attached" may refer to any of charge attachment, grafting, complexing, bonding (chemical or hydrogen bonding), or adhesion.

As used herein, "ophthalmically acceptable lens-forming components" refers to lens-forming components that can be incorporated into hydrogel contact lenses without significant discomfort (including ocular irritation, etc.) experienced or reported by the lens wearer. Ophthalmically acceptable hydrogel contact lenses have ophthalmically acceptable surface wettability and typically do not cause or are not associated with: significant corneal edema, corneal dehydration ("dry eye"), superior epithelial arch damage ("SEAL"), or other significant discomfort.

The term "organic solvent" refers to an organic substance that is capable of solvating or dissolving at least one material (such as, but not limited to, unreacted materials, diluents, etc.) present in a contact lens body that has not previously been subjected to extraction processing. In one example, the substance is one that is insoluble or does not dissolve in water or an aqueous solution. In another example, the substance is one that is not or not substantially soluble in water or an aqueous solution, i.e., the substance has increased solvation in an organic solvent as compared to water or an aqueous solution. Thus, the organic solvent contacting the unextracted contact lens body is effective to solvate or dissolve at least one substance present in the lens body, or to increase the solvation or to more greatly dissolve at least one substance present in the lens body to reduce the concentration of the at least one substance present in the lens body, or to reduce the concentration of the at least one substance in the lens body as compared to a lens body treated with water or an aqueous solution. The organic solvent may be used undiluted, i.e., 100% organic solvent, or may be used in the form of a composition comprising less than 100% organic solvent, such as, but not limited to, an aqueous solution comprising organic solvent. Generally, the organic solvent acts on (e.g., directly acts on) the at least one substance to solvate or dissolve the at least one substance. Examples of organic solvents include, but are not limited to, alcohols (e.g., alkyl alcohols such as ethanol, isopropanol, and the like), chloroform, butyl acetate, tripropylene glycol methyl ether, dipropylene glycol methyl ether acetate, and the like, and mixtures thereof.

The term "surfactant" or "surfactant component" refers to a substance that is capable of reducing the surface tension of water (e.g., water or an aqueous solution in which the substance is present). The surfactant or surfactant component facilitates the water containing the surfactant or surfactant component to more intimately contact the lens body and/or more effectively wash or remove at least one substance present in the lens body from the lens body when contacting a contact lens body that has not previously been subjected to extraction processing with an organic solvent, by reducing the surface tension of the water relative to water that is free of the surfactant or surfactant component. Generally, the surfactant or surfactant component does not act directly on the at least one substance to solvate or dissolve the at least one substance. Examples of surfactants or surfactant components include, but are not limited to, zwitterionic surfactants, including betaine forms; nonionic surfactants, including polysorbate forms (e.g., polysorbate 80), poloxamer (poloxamer) or poloxamine (poloxamine) forms; fluorinated surfactants, and the like; and mixtures thereof. In one example, one or more surfactants can be incorporated into the polymerizable compositions described herein, the wash solutions described herein, the packaging solutions described herein, and any combination thereof.

Other definitions can also be found in the following section.

Lens formulation hydrogels represent a class of materials for use in the present contact lenses. Hydrogels comprise hydrated, crosslinked polymer systems containing water in an equilibrium state. Thus, a hydrogel is a copolymer prepared from one or more reactive ingredients. These reactive ingredients may be crosslinked with a crosslinking agent.

Hydrophilic monomers the hydrophilic monomers can be, for example, silicone-containing monomers having hydrophilic moieties, non-silicone containing hydrophilic monomers, or combinations thereof. Hydrophilic monomers may be used in combination with hydrophobic monomers. The hydrophilic monomer may be a monomer having hydrophilic and hydrophobic moieties (moieties or moieties). The type and amount of hydrophilic monomer used in the polymerizable lens composition can vary depending on the type of other lens-forming monomers used. Non-limiting illustrations regarding hydrophilic monomers for use in silicone hydrogels are provided herein.

Crosslinking agents the crosslinking agents of the monomers, macromers or prepolymers used to prepare the hydrogels may include crosslinking agents known in the art, and examples of crosslinking agents are also provided herein. Suitable crosslinkers include, for example, diacrylate (or divinyl ether) functionalized ethylene oxide oligomers or monomers such as tri (ethylene glycol) dimethacrylate (TEGDMA), tri (ethylene glycol) divinyl ether (TEGDVE), Ethylene Glycol Dimethacrylate (EGDMA), and propylene glycol dimethacrylate (TMGDMA). Typically, the crosslinking agent is present in the polymerizable silicone hydrogel composition in a relatively minor total amount of the polymerizable composition, for example, in an amount in the range of from about 0.1% (w/w) to about 10% (w/w), or from about 0.5% (w/w) to about 5% (w/w), or from about 0.75% (w/w) to about 1.5% (w/w), based on the weight of the polymerizable composition.

In some examples, one or more of the monomers, macromers, or prepolymers may comprise crosslinking functionality. In these cases, a crosslinking agent is optionally additionally used in addition to the monomer, macromer or prepolymer having crosslinking functional groups, and the monomer, macromer or prepolymer having crosslinking functional groups may be present in the polymerizable silicone hydrogel composition in a relatively large amount, for example, at least about 3% (w/w), at least about 5% (w/w), at least about 10% (w/w), or at least about 20% (w/w).

Silicone hydrogel polymerizable lens-forming compositions the silicone hydrogel polymerizable lens-forming compositions can comprise at least one silicone-containing component and at least one compatible hydrophilic monomer. In some examples, the polymerizable composition can further comprise at least one compatible crosslinking agent. In particular examples, the silicone-containing component can serve as both a crosslinker and a silicone-containing component. For the polymerizable compositions discussed herein, a "compatible" component refers to a component that, when present in the polymerizable composition prior to polymerization, forms a single phase that remains stable for a duration sufficient to allow a polymerized lens body to be made from the composition. For some components, various concentrations may be found to be compatible. In addition, a "compatible" component is a component that when polymerized to form a polymerized lens body results in a lens having physical characteristics (e.g., sufficient clarity, modulus, tensile strength, etc.) sufficient for use as a contact lens.

The Si and attached O moieties (Si-O moieties) in the silicone-containing component can be present in the silicone-containing component in an amount greater than 20% (w/w), such as greater than 30% (w/w), of the total molecular weight of the silicone-containing component. Useful silicone-containing components contain polymerizable functional groups such as vinyl, acrylate, methacrylate, acrylamide, methacrylamide, N-vinyl lactam, N-vinyl amide, and styryl functional groups. The silicone-containing component that can be polymerized, for example, to obtain the contact lenses of the invention comprises one or more silicone-containing monomers, one or more silicone-containing macromers, one or more silicone-containing prepolymers, or mixtures thereof. Silicone hydrogel contact lenses made as described herein can be based on silicone-containing monomers and/or silicone-based macromers and/or silicone-based prepolymers, as well as hydrophilic monomers or comonomers, and crosslinking agents. Examples of other silicone-containing components that can be used in the lenses of the invention, in addition to the other silicone-containing compounds described herein, can be found in U.S. Pat. Nos. 3,808,178, 4,120,570, 4,136,250, 4,139,513, 4,153,641, 4,740,533, 5,034,461, 5,496,871, 5,959,117, 5,998,498 and 5,981,675, and U.S. patent application publications 2007/0066706A1, 2007/0296914A1 and 2008/0048350A1, each of which is incorporated herein by reference in its entirety. The silicone-containing component can be a silicone-containing monomer or a silicone-containing macromer or a silicone-containing prepolymer.

The silicone-containing monomer, macromer or prepolymer can have, for example, the following general formula (I):

wherein R is⁵Is H or CH₃X is O or NR⁵⁵Wherein R is⁵⁵Is H or a monovalent alkyl group having from 1 to 4 carbon atoms, a is 0 or 1, L is a divalent linking group (e.g., a polyethylene glycol chain) containing from 1 to 20 carbon atoms or from 2 to 10 carbon atoms and may also optionally contain ether and/or hydroxyl groups, p may be from 1 to 10 or from 2 to 5, R₁、R₂And R₃May be the same or different and are independently selected from the group consisting of hydrocarbyl groups having from 1 to about 12 carbon atoms (e.g., methyl groups), hydrocarbyl groups substituted with one or more fluorine atoms, siloxane groups, and groups containing siloxane chain moieties, wherein R is₁、R₂And R₃At least one of which comprises at least one siloxane unit (-OSi). For example, R₁、R₂And R₃At least one of which may comprise-OSi (CH)₃)₃and/or-OSi (R)⁵²R⁵³R⁵⁴) Wherein R is⁵²、R⁵³R⁵⁴Independently ethyl, methyl, benzyl, phenyl, or a monovalent siloxane chain comprising from 1 to about 100, or from about 1 to about 50, or from about 1 to about 20 Si-O repeat units.

R₁、R₂And R₃One, two or all three may also comprise other siloxane groups or siloxane chain-containing moieties. The combined linkage-X-L-when present in the silicone-containing monomer, macromer or prepolymer of structure (I), may contain one or more heteroatoms, which are O or N. The combinatorial linkages may be straight or branched,wherein the carbon chain segments thereof may be linear. The combined linkage-X-L-may optionally contain one or more functional groups selected from, for example, carboxyl, amide, carbamate, and carbonate. Examples of such combination linkages are provided, for example, in U.S. patent No. 5,998,498 and U.S. patent application publication nos. 2007/0066706a1, 2007/0296914a1 and 2008/0048350, the entire disclosures of each of which are incorporated herein by reference. The silicone-containing monomer, macromer or prepolymer used according to the present invention may comprise a single unsaturated group or acryloyl group, such as shown in structure (I), or it may optionally have two unsaturated groups or acryloyl groups, such as one at each end of the monomer, macromer or prepolymer. Any combination of two types of silicone-containing monomers, macromers or prepolymers optionally can be used in the polymerizable compositions that can be used in accordance with the present invention.

Examples of silicone-containing components that can be used in accordance with the present invention include, for example, but are not limited to, polysiloxanylalkyl (meth) acrylic monomers, macromers, or prepolymers, including, but not limited to, methacryloxypropyltris (trimethylsiloxy) silane, pentamethyldisiloxanylmethacrylate, and methyldi (trimethylsiloxy) methacryloxymethylsilane.

Specific examples of useful silicone-containing monomers, macromers or prepolymers can be, for example, 3- [ tris (trimethylsiloxy) silyl methacrylate]Propyl ("Tris", available from Gelest, Morrisville, Pa., USA), and monomethacryloxypropyl terminated polydimethylsiloxane ("MCS-M11", available from Gelest, Morrisville, Pa., USA). Examples of some silicone-containing monomers are disclosed in U.S. patent application publication No. 2008/0269429. These silicone-containing monomers can have an alkylene group as a divalent linking group (e.g., - (CH)₂)_p-) and "a" can be 0 for structure (I) and have at least two siloxane groups. These silicone-containing components are designated herein as silicone-containing monomers of structure (a). These silicon-containing compoundsExemplary non-limiting structures of ketone monomers are shown below:

other specific examples of silicone-containing components that may be used in the present invention may be, for example, 3-methacryloxy-2-hydroxypropoxy) propyl bis (trimethylsiloxy) methylsilane ("SiGMA", available from Girarast, Morisville, Pa., U.S.) and methyl bis (trimethylsiloxy) silylpropyl glycerol ethyl methacrylate ("SiGEMA"). These silicone-containing components include at least one hydroxyl group and at least one ether group in the divalent linking group L shown in structure (I), and at least two siloxane groups. These silicone-containing components are designated herein as silicone-containing components of the structure (B) class. Other examples and details regarding such silicone-containing components are provided, for example, in U.S. patent No. 4,139,513, which is incorporated herein by reference in its entirety. For example, SiGMA may be represented by the following exemplary, non-limiting structure:

the silicone-containing components of structures (a) and (B) may be used independently or in any combination thereof in the polymerizable compositions that may be used in accordance with the present invention. The silicone-containing component of structures (a) and/or (B) may be further used in combination with at least one non-silicone-containing hydrophilic monomer (e.g., as described herein). For example, if used in combination, the amount of the silicone-containing component of structure (A) can be, for example, from about 10% (w/w) to about 40% (w/w), or from about 15% (w/w) to about 35% (w/w), or from about 18% (w/w) to about 30% (w/w). The amount of the silicone-containing component of structure (B) can be, for example, from about 10% (w/w) to about 45% (w/w), or from about 15% (w/w) to about 40% (w/w), or from about 20% (w/w) to about 35% (w/w).

Other specific examples of useful silicone-containing components that can be used in accordance with the present invention can be chemicals represented by the following formula, or chemicals described in Japanese patent application publication No. 2008-202060A (incorporated herein by reference in its entirety), for example

Other specific examples of useful silicone-containing components that can be used in accordance with the present invention can be chemicals represented by the following formula, or chemicals described in U.S. patent application publication No. 2009/0234089 (incorporated herein by reference in its entirety). In one example, the silicone-containing component can comprise one or more hydrophilic polysiloxane components represented by the general formula (II),

wherein R is₁Selected from hydrogen or methyl; r₂Selected from hydrogen or C_1-4A hydrocarbyl group; m represents an integer of 0 to 10; n represents an integer of 4 to 100; a and b represent 1 or an integer of 1 or more; a + b equals 20 to 500; b/(a + b) equals 0.01 to 0.22; and the configuration of the siloxane units comprises a random configuration. Examples of such silicone-containing components are described in the examples section of U.S. patent application publication No. 2009/0234089, including example 2 on page 7.

Other silicone-containing components may also be used. For example, other suitable types may include, for example, poly (organosiloxane) monomers, macromers, or prepolymers, such as α, ω -bis-methacryloxy-propylpolydimethylsiloxane. Another example is mPDMS (monomethacryloxypropyl terminated mono n-butyl terminated polydimethylsiloxane). Other useful silicone-containing components include silicone-containing vinyl carbonate or vinyl carbamate monomers, macromonomers or prepolymers, including, but not limited to, 1, 3-bis [4- (vinyloxycarbonyloxy) but-1-yl ] tetramethylsiloxane 3- (vinyloxycarbonylthio) propyl- [ tris (trimethylsiloxysilane ], 3- [ tris (trimethylsiloxy) silyl ] propyl allyl carbamate, 3- [ tris (trimethylsiloxy) silyl ] propyl vinyl carbamate, trimethylsilylethyl vinyl carbonate, and trimethylsilylmethyl vinyl carbonate, examples of one or more of these silicone-containing components can be provided, for example, in U.S. Pat. No. 5,998,498 and U.S. patent application publication Nos. 2007/0066706A1, U.S. Pat. No. 4,, 2007/0296914A1 and 2008/0048350, the entire disclosure of each is incorporated herein by reference.

Some of the silicone-containing monomers, macromers or prepolymers that can be used in accordance with the present invention can be used as a single discrete monomer, macromer or prepolymer or can be used as a mixture of two or more discrete monomers, macromers or prepolymers. For example, MCR-M07 is often provided as a mixture of silicone-containing compounds having widely distributed molecular weights. Alternatively, some silicone-containing monomers, macromers or prepolymers which may be used in accordance with the present invention may be provided in the form of two or more monomers, macromers or prepolymers having discrete molecular weights. For example, X-22-1625 may be used in the lower molecular weight form, having a molecular weight of about 9000 daltons, and in the higher molecular weight form, having a molecular weight of about 18,000 daltons.

The polymerizable composition for use as described herein can include one or more hydrophobic monomers, including hydrophobic monomers that are silicone-free. Examples of the non-silicone-containing hydrophobic monomer include, but are not limited to, acrylic acid and methacrylic acid, and derivatives thereof, including methyl methacrylate. Any combination of two or more hydrophobic monomers may be employed.

Hydrophilic monomers the polymerizable compositions used to make the silicone hydrogels of the present invention include hydrophilic monomers, including non-silicone containing hydrophilic monomers. The non-silicone-containing hydrophilic monomer does not include hydrophilic compounds containing one or more silicon atoms. Hydrophilic monomers may be used in the polymerizable composition in combination with the silicone-containing monomers, macromers, or prepolymers to form the silicone hydrogel. In silicone hydrogels, the hydrophilic monomeric component comprises a component that, when combined with other polymerizable composition components, is capable of providing a resulting hydrated lens having a water content of at least about 10% (w/w), or even at least about 25% (w/w). For silicone hydrogels, the total hydrophilic monomer may comprise from about 25% (w/w) to about 75% (w/w), or from about 35% (w/w) to about 65% (w/w), or from about 40% (w/w) to about 60% (w/w) of the polymerizable composition.

Monomers that can be included as hydrophilic monomers typically have at least one polymerizable double bond, at least one hydrophilic functional group, or both. Examples of polymerizable double bonds include, for example, vinyl, acrylic, methacrylic, acrylamido, methacrylamido, fumaric, maleic, styryl, isopropenylphenyl, O-vinyl carbonate, O-vinyl carbamate, allyl, O-vinylacetyl, and N-vinyllactam and N-vinylamido double bonds. In one example, the hydrophilic monomer is a vinyl-containing monomer (e.g., an acrylic-containing monomer or a vinyl-containing monomer without acrylic acid). These hydrophilic monomers may themselves be used as crosslinking agents.

The hydrophilic monomer may be, but is not necessarily, a cross-linking agent. Considered as a subset of the above acryloyl moieties, "acrylic" or "acrylic-containing" or acrylate-containing monomers are monomers containing an acrylic group (CR' H ═ CRCOX), where R is H or CH₃R' is H, alkyl or carbonyl, and X is O or N, which are also known to be readily polymerizable.

For silicone hydrogels, the hydrophilic component may comprise a non-silicon containing hydrophilic monomer component comprising an acrylic monomer (e.g., a monomer having a vinyl group at the α -carbon position and having a carboxylic acid terminus, a monomer having a vinyl group at the α -carbon position and having an amide terminus, etc.) and a vinyl group (CH) containing group₂Hydrophilic monomer (i.e. CH-)Monomers containing vinyl groups that are not part of the acrylic groups).

Illustrative acrylic monomers include N, N-Dimethylacrylamide (DMA), 2-hydroxyethyl acrylate, glycerol methacrylate, 2-hydroxyethyl methacrylate (HEMA), methacrylic acid, acrylic acid, Methyl Methacrylate (MMA), ethylene glycol methyl ether methacrylate (EGMA), and any mixtures thereof. In one example, the total acrylic monomer content is in an amount ranging from about 5% (w/w) to about 50% (w/w) of the polymerizable composition used to prepare the silicone hydrogel lens product, and may be present in an amount ranging from about 10% (w/w) to about 40% (w/w), or from about 15% (w/w) to about 30% (w/w) of the polymerizable composition.

Hydrophilic vinyl-containing monomers that can be incorporated into the lens materials of the present invention include, but are not limited to, N-vinyl lactams (e.g., N-vinyl pyrrolidone (NVP)), N-vinyl-N-methyl acetamide (VMA), N-vinyl-N-ethyl acetamide, N-vinyl-N-ethyl formamide, N-vinyl formamide, N-2-hydroxyethyl vinyl carbamate, N-carboxy- β -alanine N-vinyl ester, and the like, and mixtures thereof₃C(O)N(CH₃)-CH＝CH₂. In one example, the total vinyl-containing monomer content of the polymerizable composition is in an amount in the range of about 0% (w/w) to about 50% (w/w), e.g., up to about 50% (w/v), of the polymerizable composition used to prepare the silicone hydrogel lens product, and can be present in an amount in the range of about 20% (w/w) to about 45% (w/w), or about 28% (w/w) to about 40% (w/w), of the polymerizable composition. Other silicone-free lens-forming hydrophilic monomers known in the art may also be suitable.

Other examples are hydrophilic vinyl carbonate or vinyl carbamate monomers disclosed in U.S. Pat. No. 5,070,215, which is incorporated herein by reference in its entirety, and hydrophilic oxazolone monomers disclosed in U.S. Pat. No. 4,190,277, which is incorporated herein by reference in its entirety. Other suitable hydrophilic monomers will be apparent to those skilled in the art. More preferably, hydrophilic monomers that can be incorporated into the polymers of the present invention include hydrophilic monomers such as N, N-Dimethylacrylamide (DMA), 2-hydroxyethyl acrylate, glycerol methacrylate, 2-hydroxyethyl methacrylamide, N-vinyl pyrrolidone (NVP), and polyethylene glycol monomethacrylate. In certain examples, hydrophilic monomers including DMA, NVP, and mixtures thereof are employed.

Other examples of materials used to make silicone hydrogel contact lenses include those disclosed in U.S. patent No. 6,867,245.

Crosslinking agents that may be used in the manufacture of the present contact lenses, such as the present silicone hydrogel contact lenses, include, but are not limited to, the crosslinking agents indicated above. Examples of acrylate functionalized ethylene oxide oligomers that may be used in the crosslinking agent may include oligomeric ethylene oxide dimethacrylates. The crosslinker can be TEGDMA, TEGDVE, EGDMA, TMGDMA, or any combination thereof. Typically, the crosslinking agent is present in the polymerizable silicone hydrogel composition in a relatively minor total amount of the polymerizable composition, for example, in an amount in the range of from about 0.1% (w/w) to about 10% (w/w), or from about 0.5% (w/w) to about 5% (w/w), or from about 0.75% (w/w) to about 1.5% (w/w), based on the weight of the polymerizable composition.

Other hydrogel components the polymerizable composition used in the lenses and in the methods described herein may also include other components, such as one or more initiators (e.g., one or more thermal initiators, one or more Ultraviolet (UV) initiators, visible light initiators, any combination thereof, and the like), one or more UV absorbers or compounds, or UV radiation or energy absorbers, colorants, pigments, mold release agents, antimicrobial compounds, and/or other additives. In the context of the present invention, the term "additive" refers to a compound or any chemical agent provided in the hydrogel contact lens polymerizable composition or polymerized hydrogel contact lens product of the present invention but not necessary for the manufacture of a hydrogel contact lens.

The polymerizable composition may comprise one or more initiator compounds, i.e., compounds capable of initiating polymerization of the polymerizable composition. Thermal initiators, i.e., initiators having a "kick-off" temperature, may be used. Exemplary thermal initiators useful in the polymerizable compositions of the present invention include, for example, 2' -azobis (isobutyronitrile) (AIBN,-64), 2' -azobis (2, 4-dimethylvaleronitrile), (b-methyl-ethyl-N-methyl-N--52), 2' -azobis (2-methylbutyronitrile) ((II) and (III)-67) and 1, 1' -azobis (cyclohexanecarbonitrile) ((C)-88). For theThermal initiators, the rating numbers (i.e., 64, 52, 67, 88, etc.) are the temperatures in degrees celsius when the half-life of the initiator in solution is 10 hours. All of which are described hereinThermal initiators are all available from DuPont (DuPont) (Wilmington, del, USA). Other thermal initiators (including nitrite) and other types of initiators are available from sigma aldrich. Ophthalmically compatible silicone hydrogel contact lenses can be obtained from polymerizable compositions comprising from about 0.05% (w/w) to about 0.8% (w/w), or from about 0.1% (w/w) to about 0.6% (w/w)-64 or other thermal initiators.

The UV absorber can be, for example, a strong UV absorber that exhibits relatively high absorbance values in the UV-a range of about 320 to 380 nanometers, but is relatively transparent above about 380 nm. Examples include photopolymerizable hydroxybenzophenones and photopolymerizable benzotriazoles such as 2-hydroxy-4-acryloxyethoxybenzophenone (available as CYASORBUV416 from Cytec industries, Inc.; Cytec industries, West Paterson, NJ, USA, West Pasteur, N.J.), 2-hydroxy-4- (2-hydroxy-3-methacryloyloxy) propoxybenzophenone, and the like7966 photopolymerizable benzotriazoles are available from Nolam corporation (Noramco) of Athens, Georgia, USA. Other photopolymerizable UV absorbers suitable for use in accordance with the present invention include polymerizable ethylenically unsaturated triazines, salicylates, aryl-substituted acrylates, and mixtures thereof. Generally, the UV absorber (if present) is provided in an amount corresponding to about 0.5% by weight of the polymerizable composition to about 1.5% by weight of the composition. For example, the composition may include from about 0.6% (w/w) to about 1.0% (w/w) of one or more UV absorbers.

Polymerizable compositions useful according to the present invention can also include colorants, but encompass tinted and clear lens products. In one example, the colorant is a reactive dye or pigment effective to provide color to the resulting lens product. Colorants can include, for example, VAT blue 6(7, 16-dichloro-6, 15-dihydroanthracene azine-5, 9, 14, 18-tetrone), 1-amino-4- [3- (. beta. -sulfatoethylsulfonyl) anilino ] -2-anthraquinone sulfonic acid (c.i. reactive blue (ReactiveBlue)19, RB-19), copolymers of reactive blue 19 with hydroxyethyl methacrylate (RB-19HEMA)1, 4-bis [4- [ (2-methacryloyl-oxyethyl) phenylamino ] anthraquinone (reactive blue 246, RB-246, available from arran chemical company of aislon (Athlone, Ireland)), 1, 4-bis [ (2-hydroxyethyl) amino ] -9, 10-anthracenedione bis (2-acrylate) ester (RB-247), and mixtures thereof, Reactive blue 4(RB-4) or a copolymer of reactive blue 4 with hydroxyethyl methacrylate (RB-4HEMA or "BlueHEMA"). Other exemplary colorants are disclosed, for example, in U.S. patent application publication No. 2008/0048350, the disclosure of which is incorporated herein by reference in its entirety. Other suitable colorants for use in accordance with the present invention are phthalocyanine pigments (e.g., phthalocyanine blue and phthalocyanine green), chromium-alumina-cobaltous oxide, chromium oxide, and various iron oxides of red, yellow, brown, and black colors. Opacifiers (opaquinagent) such as titanium dioxide may also be incorporated. For some applications, mixtures of colors may be employed. If employed, the colorant can be present in an amount ranging from about 0.1% (w/w) to about 15% (w/w), or from about 1% (w/w) to about 10% (w/w), or from about 4% (w/w) to about 8% (w/w).

The polymerizable composition may also comprise a release aid, that is, one or more ingredients effective to make the cured contact lens more easily removable from its mold. Exemplary release aids include hydrophilic silicones, polyalkylene oxides, and any combination thereof. The polymerizable composition may further comprise a diluent selected from the group consisting of: hexanol, ethoxyethanol, Isopropanol (IPA), propanol, decanol, and any combination thereof. If employed, the diluent is typically present in an amount in the range of about 10% (w/w) to about 30% (w/w). Compositions with relatively higher diluent concentrations tend to have, but are not necessarily, lower ion flow values, reduced modulus and increased elongation, as well as Water Break Up Times (WBUT) of greater than 20 seconds. Other materials suitable for use in the manufacture of hydrogel contact lenses are described in U.S. patent No. 6,867,245, the disclosure of which is incorporated herein by reference in its entirety. However, in certain examples, the polymerizable composition is free of diluent.

In one particular example of a polymerizable composition, the composition comprises a first monomer having a first reactivity ratio, and a second monomer having a second reactivity ratio that is less than the first reactivity ratio. It will be appreciated by those skilled in the art that reactivity ratio can be defined as the ratio of the reaction rate constant for each propagating species adding its own monomer to the rate constant for its addition of other monomers. The composition may also include at least one crosslinker having a reactivity ratio similar to the first reactivity ratio or the second ratio. The composition may also include at least two crosslinking agents, a first crosslinking agent having a reactivity ratio similar to the first reactivity ratio and a second crosslinking agent having a reactivity ratio similar to the second reactivity ratio. In certain examples, the lens precursor composition can include one or more removable additives. For example, the polymerizable composition may include one or more compatibilizing agents, release aids, delensing aids, wettability enhancers, and ion flux reducing agents (ionoflurandreducts), which are removable.

Silicone-containing hydrogel contact lenses are often referred to as silicone hydrogel contact lenses. Many silicone hydrogel contact lenses are based on polymerizable lens formulations that include a siloxane monomer, a macromer, a prepolymer, or any combination thereof, and at least one hydrophilic monomer, as previously described. Some examples of silicone hydrogel contact lens materials include materials having the following USANs: echofilcon A (acquafilcon A) or echofilcon B, balafilcon A (balafilcon A), camfelcon A, enfilcon A (enfilcon A), galifilcon A (galyfilcon A), lenefilcon A (lenefilcon A), rhotefilcon A (lotrafilcon A), rhotefilcon B, cronofilcon A (senofilcon A), narafilcon A (narafilcon A) and phenanthrene 3(filcon II 3). In one example, a lens body having ophthalmically acceptably wettable anterior and posterior surfaces without applying a surface treatment to the lens body or without the presence of an Interpenetrating Polymer Network (IPN) of a polymeric wetting agent in the lens body is a camofukan a silicone hydrogel contact lens body.

A method of manufacturing an ophthalmic lens, such as a silicone hydrogel contact lens, is illustrated in fig. 1. According to the present invention, all of the steps illustrated in fig. 1 or a subset of the steps illustrated in fig. 1 may comprise a method of manufacturing an ophthalmic lens. Items used as inputs, outputs or both inputs and outputs for the steps of fig. 1 are illustrated in fig. 2.

Fig. 1 includes a step 102 of providing a vinyl alcohol copolymer having a high amorphous content. The vinyl alcohol copolymer with high amorphous content is illustrated in fig. 2 as element 202.

Step 104 of fig. 1 illustrates the step of forming at least one of the first mold member and the second mold member, or forming at least one molding surface of at least one of the first mold member and the second mold member, using the vinyl alcohol copolymer with high amorphous content. Element 204 of fig. 2 illustrates the resulting mold member or molding surface comprising the vinyl alcohol copolymer with its amorphous content.

FIG. 1 also includes a step 106 of placing a polymerizable composition on or in the mold member. According to the present invention, polymerizable compositions can be understood to be lens-forming compositions, such as silicone hydrogel contact lens-forming polymerizable compositions. The polymerizable composition is illustrated in fig. 2 as element 206. Polymerizable compositions are understood to be prepolymerized or precured compositions suitable for polymerization.

Typically, the polymerizable composition or lens precursor composition is not polymerized prior to curing or polymerizing the composition. However, the polymerizable composition or lens precursor composition may be partially polymerized before undergoing the curing process. In some examples, the polymerizable composition can include a polymer component that becomes crosslinked with other components of the polymerizable composition during the curing process. The polymer component can be one that is not a polymeric wetting agent or care agent, does not form an interpenetrating polymer network in the lens body, or is neither a polymeric wetting agent or care agent nor forms an IPN in the lens body.

The lens precursor compositions of the present invention can be provided in a container, dispensing device, or mold part prior to a curing or polymerization procedure, as described herein. Referring to fig. 1, in step 106, a lens precursor composition is placed onto the lens forming surface (i.e., the area used to mold the lens surface) of either a female mold part or a male mold. The female mold member can be understood as a first mold member or a front mold member, while the male mold member can be understood as a second mold member or a back mold member. For example, the female mold member can include a molding surface that defines the front or obverse surface of a lens manufactured by a lens mold. The second mold member can be understood as a male mold member or a posterior mold member. For example, the second mold member comprises a molding surface defining the posterior surface of the ophthalmic lens manufactured in the ophthalmic lens mold (i.e., the second or male mold member has a convex lens forming surface).

Further, according to the present invention, at least one of the first and second mold members, or the molding surface of at least one of the first and second mold members, comprises, includes a substantial amount of, consists essentially of, or consists of the vinyl alcohol copolymer having a high amorphous content as described herein. In one example, a mold member or molding surface as described herein has been fabricated to have a molding surface that is polar to a degree sufficient to produce silicone hydrogel contact lenses having ophthalmically acceptably wettable surfaces (e.g., an average polarity of about 0.25% to about 8%, about 1% to about 7%, 2% to about 5%, about 1% to about 4%, or about 3%). The average polarity of a polymer can be determined based on the Owens-Wendt-Rabel-kaebel model (Owens-Wendt-Rabel-kaebel model), in which the contact angle of a thermoplastic polymer is determined using a variety of different liquids of known polarity. The owens-wendt-rabel-kaebel equation can be written in the form of a linear equation, where y is calculated based on the observed contact angle (θ) of each different liquid with the polymer, and x is based on the total surface energy (σ) of each different liquid_L ^T) Of known polarity (σ)_L ^P) And dispersion (σ)_L ^D) And (4) component calculation. The data points (x, y) obtained from different liquids can be plotted and then the slope (m) and y-intercept (b) can be determined using linear regression of the plot. The calculated slope and y-intercept can then be used to calculate the total surface energy (σ) of the polar thermoplastic polymer_S ^TWhere σ is_S ^T＝σ_S ^P+σ_S ^D) Polarity (σ) of (C)_S ^P) And dispersion (σ)_S ^D) And (4) components.

An owens-wentt-rabel-kaebel equation in the form of a linear equation:

whereinAnd is

Examples of liquids with different polarities that can be used to determine the average polarity of the polymer include, but are not limited to, deionized water, diiodomethane, dimethyl sulfoxide (DMSO), and formamide. In selecting liquids with different polarities, it is desirable that the polar component (σ) based on the total surface energy of the liquids should be based on_L ^P) Selecting a plurality of liquids having a plurality of polarities rather than different total surface energies (σ)_L ^T) A plurality of liquids. Using this method, the polar component (σ) is calculated by using the total surface energy of the polymer_S ^P) Divided by its calculated total surface energy (σ)_S ^T) And multiplied by 100 to obtain the percent polarity to calculate the average polarity of the polymer.

To form the mold assembly, the first mold member is placed in contact with the second mold member, thereby forming a contact lens-forming cavity in the space between the first mold member and the second mold member. The method illustrated in FIG. 1 comprises the step 108 of forming a contact lens mold assembly by placing two contact lens mold members in contact with each other to form a lens-shaped cavity therebetween. For example, referring to fig. 2, after step 108 is performed, the polymerizable silicone hydrogel lens precursor composition 206 is located in the contact lens molding cavity.

At step 110, the method illustrated in FIG. 1 includes curing the polymerizable composition to form a polymerized lens body that is received in a mold assembly, as illustrated in FIG. 2 with element 208. At this point in the process, the polymerized lens body is not exposed to the liquid. In one example, the polymerized lens body can be a polymerized silicone hydrogel contact lens body. During curing, the components of the polymerizable composition polymerize to form a polymerized lens body. Thus, curing may also be understood as a polymerization step. Curing 110 can include exposing the polymerizable lens precursor composition to a form of electromagnetic radiation effective to polymerize the components of the lens precursor composition. For example, curing 110 can include exposing the polymerizable composition to a polymerizing amount of a form of electromagnetic radiation, such as heat or Ultraviolet (UV) light. Curing 110 may also include curing the composition in an oxygen-free or nearly oxygen-free environment. For example, curing 110 may occur in the presence of nitrogen or other inert gas. Curing 110 can be effective to fully polymerize the polymerizable composition or can polymerize the polymerizable composition to a level that allows the lens body to retain its molded shape suitable for use as a contact lens upon processing (e.g., demolding, delensing, washing, packaging, sterilization, etc.).

Polymeric lens bodies that are not exposed to liquid may be present at various stages of the manufacturing process depending on the type of demolding and delensing process used and whether one or more optional washing steps are performed. For example, a polymeric lens body that is not exposed to a liquid may be a polymeric lens body prior to undergoing a wet demolding process, a wet delensing process, a wet demolding and delensing process, an optional washing process, and any combination thereof. For example, the washing process can be a cleaning process that removes dust or debris, an extraction process that removes a portion or substantially all of one or more extractable components from the polymerized lens body, or a hydration process that partially or fully hydrates the hydrogel lens body. For example, a polymeric lens body that is not contacted with a liquid can include a lens body that is present in a lens-shaped cavity of a mold assembly or two molding surfaces after a curing process; can include a lens body that is in contact with one and only one mold member after a dry demolding process; or may comprise a contact lens body that is present in a tray or other device after the dry demolding and dry delensing processes. The polymeric lens body that is not exposed to liquid may include a lens-forming component, such as a silicon-containing polymer network or matrix in the shape of a lens; and a removable component that can be removed from the lens body after polymerization. The removable component is understood to include unreacted monomers, oligomers, partially reacted monomers, or other agents that are not covalently attached to or otherwise immobilized relative to the lens-forming component. Removable components can also be understood to include one or more additives, including diluents, that can be removed from the polymerized lens product during a cleaning, extraction, or hydration procedure (as discussed herein). Thus, the material of the removable component may comprise a polymer of the extractable material in a linear uncrosslinked or slightly crosslinked or branched form that is not crosslinked to or otherwise fixed relative to the polymeric backbone, network or matrix of the lens body.

After curing the polymerizable composition, the method illustrated in FIG. 1 includes a step 112 of separating the polymerized lens body from the mold member. In one example, the process of separating the polymerized lens body from the mold members can include a demolding process such that the polymerized lens body remains in contact with one and only one of the mold members used to form the lens body. After the demolding process, the polymerized lens body is located on, or remains in contact with, only one mold member of the mold assembly. The one and only one mold member that the lens body remains in contact with after demolding can be the mold member 204 formed using the vinyl alcohol copolymer 202, or can be a different mold member. When the step 112 of separating the polymerized lens body from the mold member comprises a demolding process, the separating step may further comprise a delensing step, i.e., releasing the lens body from the one and only one mold member with which it remains in contact after the demolding process. Depending on which mold part the polymerized lens body remains in contact with after the demolding process, the lens body can be delensed from either the male or female mold part. Alternatively, step 112 can comprise a combined demolding and delensing process wherein the lens body is simultaneously released from all of the mold members used to form it. When at least one of the mold members or molding surfaces used to form the lens body comprises a vinyl alcohol copolymer with high amorphous content, the separation process can involve applying a liquid to the lens body and at least one of the mold members or molding surfaces (in the form of a mold assembly, a single mold member, a pair of molding surfaces, or one molding surface that is in contact with or separate from the non-molding region of the mold member) to at least partially dissolve the vinyl alcohol copolymer and thereby release the lens body from the mold assembly, single mold member, or molding surface. The liquid used in the wet separation process may comprise water or an aqueous solution.

The method illustrated in fig. 1 optionally includes a step 114 of washing the lens body by contacting the polymerized lens body with a liquid (e.g., an organic solvent solution, water, or an aqueous solution) to clean dust or debris in the lens body, to extract the lens body to remove extractable material from the lens body, or to fully or partially hydrate the lens body. In one example, the washing step 114 may include a washing step that removes or dilutes the liquid used during the wet demolding process, the wet delensing process, or both. The washing step 114 results in a cleaned, extracted, or hydrated lens body 210, as shown in fig. 2. The washing step 114 can optionally be performed on a mold assembly comprising a polymeric lens body, a polymeric lens body that remains in contact with one mold member, a lens body that has been completely released from all molds used to form the lens body, and can be repeated during the manufacturing process.

The washing step 114 can optionally include a step of hydrating the polymerized lens body. The hydrating step can comprise contacting the polymerized lens bodies, or one or more batches of such lens bodies, with water or an aqueous solution to form a hydrated lens product, such as a silicone hydrogel contact lens. The hydrating step can completely or partially hydrate the lens body. In one example, the polymeric lens body hydrated in the hydration step is a delensed polymeric lens body that has not been contacted with a liquid prior to the hydration step, or may comprise a polymeric lens body that has been previously contacted with a liquid.

After the separation step 112 and optional washing step 114, the method illustrated in fig. 1 may optionally include a step 116 of packaging the lens body to produce a packaged ophthalmic lens product 212. For example, the lens body can be placed in a blister pack, vial, or other suitable container with a volume of a packaging liquid (e.g., a physiological saline solution, including a buffered physiological saline solution). In one example, the washing step 114 and the packaging step 116 can be performed simultaneously by placing the polymeric lens body (including the polymeric lens body not previously contacted with liquid) into a blister package or container with a portion of the packaging liquid that serves as both the packaging solution and the hydration solution. In another example, the separating and packaging steps can be performed simultaneously by placing the polymeric lens body in contact with the mold assembly, both molding surfaces of the mold assembly, one mold member, or one molding surface, in a blister package or container with a portion of the packaging liquid used to release the lens body by dissolving the vinyl alcohol copolymer mold member or molding surface.

Optionally, the method illustrated in fig. 1 may further comprise one or more inspection steps 118. In the example illustrated in fig. 1, the inspection step is performed after the packaging step, before the packaging is sealed and sterilized, but one or more inspection steps may be performed on either a dry lens or a wet lens at any point in the process (either before or after curing). For example, inspection can be performed on one or more mold members to determine the acceptability of the molding surface; the mold part can be subjected to after the polymerizable composition is placed to detect the presence of air bubbles in the polymerizable composition; performing on the dried lens after curing to determine the acceptability of the dried lens body; or upon separation, washing or packaging to determine the acceptability of the wet lens body. The result of optional inspection step 118 as illustrated in fig. 1 is a packaged inspected body 214, but may include an inspected mold member, an inspected polymerizable composition in a mold member, an inspected dry lens body, or an inspected wet lens body in other processes.

Following the step 116 of packaging the lens bodies, the blister package or container containing the packaged lens bodies 212 may be sealed and subsequently sterilized (as shown in optional step 120 of fig. 1) to produce a sterilized package containing an ophthalmic lens product (e.g., a contact lens). The packaged lens body can be exposed to a sterilizing amount of radiation, including heat (e.g., by autoclaving), gamma radiation, electron beam radiation, ultraviolet radiation, and the like. Depending on the process steps previously used, the sterilization process may also be used to partially or fully extract, fully hydrate, or extract and hydrate the packaged lens body, or dissolve the mold member or molding surface comprising the vinyl alcohol copolymer.

The following non-limiting examples illustrate certain aspects of the present methods and apparatus.

Example 1(comparative example, theory)

Ethylene-vinyl alcohol copolymers having low amorphous content are provided in the form of particles or pellets. A portion of the polymer is processed by conventional injection molding into a contact lens mold member. Polymerizable compositions for making silicone hydrogel contact lenses are prepared as described herein and are used to prepare a plurality of cast-molded polymerized silicone hydrogel lens bodies as illustrated in fig. 1. The mold assembly comprising the polymerizable composition is cured using heat or UV radiation. After curing, the mold assembly comprising the cast-molded polymeric lens body is wet or dry demolded to separate the two mold members of the mold assembly. After the dry demolding step, the polymeric lens body is released from one of the mold members with which it remains in contact after the demolding step using a wet delensing process. The released lens body is then washed sequentially with a liquid comprising an organic solvent and an aqueous solution substantially free of organic solvent, or with an aqueous solution substantially free of organic solvent. The washing step may include an additional hydration step, or may include a separate hydration step prior to packaging and sterilization of the lens body. The yield of acceptable lens bodies is less than about 65%.

Example 2(theory)

Vinyl alcohol copolymers having a high amorphous content are provided in the form of particles or pellets. A portion of the polymer is processed by conventional injection molding into a contact lens mold member. Polymerizable compositions for making silicone hydrogel contact lenses are prepared as described herein and are used to prepare a plurality of cast-molded polymerized silicone hydrogel lens bodies as illustrated in fig. 1. The mold assembly comprising the polymerizable composition is cured using heat or UV radiation. After curing, the mold assembly comprising the cast-molded polymeric lens body is wet or dry demolded to separate the two mold members of the mold assembly. After the dry demolding step, the polymeric lens body is released from one of the mold members with which it remains in contact after the demolding step using a wet delensing process. The released lens body is then washed sequentially with a liquid comprising an organic solvent and an aqueous solution substantially free of organic solvent, or with an aqueous solution substantially free of organic solvent. The washing step may include an additional hydration step, or may include a separate hydration step prior to packaging and sterilization of the lens body. The yield of acceptable lens bodies is greater than about 75%. When the manufacturing process involves minimal handling of the lens body, where the mold assembly is placed into a blister package and the lens body is dissolved in the blister package by the mold assembly, followed by demolding and delensing the lens body by washing in the blister package, the yield of acceptable lens bodies is greater than about 85%.

Example 3(theory)

Providing certain NichigoG-polymers having a high amorphous content in the form of granules or pellets^TMA vinyl alcohol copolymer. A portion of the polymer is processed by conventional injection molding into male and female contact lens mold members. Polymerizable compositions for making silicone hydrogel contact lenses are prepared as described herein and are used to prepare a plurality of cast-molded polymerized silicone hydrogel lens bodies as illustrated in fig. 1. The mold assembly comprising the polymerizable composition is cured using heat or UV radiation. After curing, the mold assembly comprising the cast-molded polymeric lens body is simultaneously wet demolded and delensed by placing the mold assembly comprising the polymeric lens body into a tray and applying a liquid to the mold assembly to at least partially dissolve the vinyl alcohol copolymer, thereby releasing the lens body from both molds of the mold assembly. Optionally, the mold assembly, mold members, or liquid can be agitated during the demolding and delensing steps. The released lens body is then transferred to a blister package with packaging solution, and sealed and sterilized.

Claims (20)

1. A method of manufacturing an ophthalmic lens, comprising:

(a) providing at least one vinyl alcohol copolymer having a high amorphous content, wherein the at least one vinyl alcohol copolymer having a high amorphous content is a vinyl alcohol copolymer having an average level of crystallinity from 10% to 30%;

(b) forming at least one of a first mold member and a second mold member using the at least one vinyl alcohol copolymer with high amorphous content, the first mold member comprising a concave molding surface configured to mold an anterior surface of a lens and the second mold member comprising a convex molding surface configured to mold a posterior surface of a lens, the first mold member and the second mold member configured to form a lens-shaped cavity therebetween when combined as a mold assembly;

(c) placing a polymerizable composition comprising at least one hydrophilic monomer into the first mold member or the second mold member;

(d) assembling the mold assembly by contacting the first mold member with the second mold member, thereby forming the lens-shaped cavity therebetween, wherein the polymerizable composition is contained in the lens-shaped cavity of the mold assembly; and

(e) curing the polymerizable composition in the mold assembly to form a cast-molded polymeric reaction product in the lens-shaped cavity of the mold assembly, the polymeric reaction product comprising an ophthalmic lens body.

2. The method of claim 1, wherein the at least one vinyl alcohol copolymer with high amorphous content is a vinyl alcohol copolymer with an average level of crystallinity from 15% to 25%.

3. The method of claim 1, wherein the at least one vinyl alcohol copolymer with high amorphous content has a melting point of 140 ℃ to 190 ℃.

4. The method of claim 1, wherein the at least one vinyl alcohol copolymer with high amorphous content has a glass transition temperature of 60 ℃ to 85 ℃.

5. The method of claim 1, wherein the step of placing the polymerizable composition into one of the first mold member or the second mold member comprises placing a polymerizable composition comprising at least one silicone monomer, silicone macromer, silicone prepolymer, or combination thereof, and at least one hydrophilic monomer into the first mold member, and wherein the ophthalmic lens body comprises a silicone hydrogel contact lens body.

6. The method of claim 1, wherein the step of forming at least one of the first mold member and the second mold member using the at least one vinyl alcohol copolymer with high amorphous content comprises injection molding the at least one of the first mold member and the second mold member.

7. The method of claim 6, wherein injection molding the at least one of the first mold member and the second mold member includes forming a molding surface of at least one of the first mold member and the second mold member entirely by injection molding.

8. The method of claim 6, wherein injection molding the at least one of the first mold member and the second mold member includes forming a body of at least one of the first mold member and the second mold member by injection molding and forming a molding surface of the at least one of the first mold member and the second mold member by machining the injection molded body.

9. The method of claim 8, wherein the machining is lathing or cutting.

10. The method of claim 6, wherein the process of injection molding the vinyl alcohol copolymer with high amorphous content uses a process setting selected from the group consisting of: a melt temperature of 180 ℃ to 250 ℃, a barrel temperature of 180 ℃ to 250 ℃, a top temperature of 30 ℃ to 70 ℃, a mold tool temperature of 30 ℃ to 95 ℃, a hold time of 1 second to 5 seconds, an injection velocity of 50 mm/second to 250 mm/second, a plasticizing velocity of 100 mm/second to 300 mm/second, an injection pressure of 50 bar to 180 bar, a hold pressure of 10 bar to 200 bar, a back pressure of 5 bar to 25 bar, and any combination thereof.

11. The method of claim 1, wherein the step of forming at least one of the first mold member and the second mold member using the at least one vinyl alcohol copolymer with high amorphous content comprises forming a molding surface on the at least one of the first mold member and the second mold member using the at least one vinyl alcohol copolymer with high amorphous content, a non-molding region of the at least one of the first mold member and the second mold member being formed from a second material, and wherein the step of placing the polymerizable composition into the first mold member or the second mold member comprises placing the polymerizable composition in direct contact with the molding surface comprising the vinyl alcohol copolymer with high amorphous content.

12. The method of claim 1, wherein the lens body has ophthalmically acceptably wettable anterior and posterior surfaces without applying a surface treatment to the lens body or in the absence of components in the polymerizable composition that form an interpenetrating network (IPN) of a wetting agent in the lens body during the curing.

13. The method of claim 1, wherein the method further comprises the step of separating the mold assembly, the separating maintaining the lens body in contact with one and only one of the first mold member and the second mold member, the one and only one of the first mold member and the second mold member being the at least one of the first mold member and the second mold member comprising the at least one vinyl alcohol copolymer with high amorphous content; or releasing the lens body from all of the mold parts used to form the lens body.

14. The method of claim 13, wherein the step of separating the mold assembly comprises applying a liquid to the at least one of the first mold member and the second mold member comprising the at least one vinyl alcohol copolymer with high amorphous content, thereby at least partially dissolving the at least one of the first mold member and the second mold member comprising the at least one vinyl alcohol copolymer with high amorphous content in the liquid.

15. The method of claim 14, wherein the applying the liquid further comprises agitating the liquid, or agitating the at least one of the first mold member and the second mold member comprising the at least one vinyl alcohol copolymer with high amorphous content.

16. The method of claim 14, wherein the dissolving the at least one of the first mold member and the second mold member comprising the at least one vinyl alcohol copolymer with high amorphous content is conducted at a temperature of 70 ℃ or less than 70 ℃, and the at least one of the first mold member and the second mold member comprising the at least one vinyl alcohol copolymer with high amorphous content is completely dissolved in less than 240 minutes.

17. The method of claim 1, wherein the method further comprises the step of placing the mold assembly comprising the cast-molded polymeric reaction product in the lens-shaped cavity into a blister package with a packaging solution, and sealing and sterilizing the package, wherein the mold assembly is completely dissolved in the packaging solution after sterilization.

18. The method of claim 17, wherein the molding surface of at least one of the first mold member and the second mold member comprises the at least one vinyl alcohol copolymer with high amorphous content, and a non-molding region of the at least one of the first mold member or the second mold member is formed from at least one polymeric material that is insoluble in the packaging solution and is configured to be used as a blister package.

19. A packaged silicone hydrogel contact lens body, comprising:

a blister package formed from a hydrophobic polymeric material;

a cast-molded polymeric lens body comprising the reaction product of a polymerizable composition comprising at least one silicone monomer, silicone macromer, silicone prepolymer, or any combination thereof, and at least one hydrophilic monomer; and

a liquid comprising a dissolution product of at least one vinyl alcohol copolymer with high amorphous content in a packaging solution, wherein the at least one vinyl alcohol copolymer with high amorphous content is a vinyl alcohol copolymer with an average level of crystallinity from 10% to 30%.

20. A mold member for cast molding a silicone hydrogel contact lens body, comprising:

a mold member comprising a molding surface and a non-molding region, wherein at least the molding surface of the mold member comprises at least one vinyl alcohol copolymer with high amorphous content, wherein the at least one vinyl alcohol copolymer with high amorphous content is a vinyl alcohol copolymer with an average level of crystallinity from 10% to 30%.