JP2000162555A - Production of soft contact lens - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily separate contact lenses from male molds and to decrease the number of production processes in a single side mold method by separating the male molds and the contact lenses sticking to the male molds in a hydrophilic organic solvent or its aqueous solution. SOLUTION: The contact lens 7 sticking to the male mold 1 is separated by immersing the contact lens into the hydrophilic organic solvent or its aqueous solution. Water-soluble alcohols, such as ethanol and isopropyl alcohol, are adequate as the hydrophilic organic solvent as these alcohols are less harmless to the human bodies, are easily removable, are high and wide in penetratability to the lenses and are generally less influential to the soft contact lenses. A surfactant may be compounded with the hydrophilic organic solvent or its aqueous solution to be used in the immersion treatment in the hydrophilic organic solvent or its aqueous solution. If the male mold 1 is formed of an ethylene/vinyl alcohol copolymer, the half-finished lens may be stably cut and polished without peeling from the male mold 1 during cutting and polishing stages.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a soft contact lens, and more particularly to a method for manufacturing a soft contact lens in which a base curve surface in contact with a cornea is formed by a mold and a front curve surface is formed by cutting.

[0002]

2. Description of the Related Art In recent years, soft contact lenses have been widely used by people who could not wear conventional hard contact lenses because of their good wearing feeling, and the proportion of soft contact lens wearers is increasing.

[0003] Therefore, there is a need for a technique for producing low-cost, high-quality soft contact lenses.

[0004] Conventionally, contact lens production methods include a lathe cutting method in which both surfaces of a button-shaped contact lens material cut or molded from a rod are cut and polished with a lathe, and a molding method having a lens-shaped cavity. This cavity is filled with a polymerizable monomer using a mold, and a batch molding method to obtain a contact lens by polymerizing the polymer is poured into a rotating mold, and the contact is made using the fact that the raw material spreads thinly by centrifugal force. A spin casting method for manufacturing a lens is known.

[0005] Although the lace cut method can produce all kinds of contact lenses, it has a problem that the production cost is high. The batch molding method has a low manufacturing cost, but requires the production of many types of contact lenses to produce various types of contact lenses with different shapes.Dimensional accuracy and surface accuracy are greatly affected by the accuracy of the mold. There is a problem that it is difficult to manufacture a good contact lens. In addition, although the spin casting method has a low production cost, it is necessary to control many factors such as the viscosity of the polymerizable monomer, the surface tension, the amount, the number of rotations, and it is difficult to produce a contact lens with high accuracy. However, there is a problem that applicable lens materials are limited to specific ones.

Therefore, in recent years, there has been proposed a manufacturing method called a one-sided molding method, which is an intermediate method between a race cutting method and a batch molding method, in which a semifinished lens product is manufactured by a molding method, and then a contact lens is manufactured by cutting. .

In the single-sided molding method, in a soft contact lens, a base curve surface directly contacting the cornea of the contact lens does not require so many types. Therefore, the base curve surface is directly molded by a mold by a molding method. After manufacturing a semifinished lens having a thickness several times to several tens times the thickness required for a lens, the front curve surface for determining the power is formed by cutting.

The single-sided molding method has a feature that, since the front curve side can be formed to have an arbitrary curvature by cutting, not only the frequency and the center thickness can be set freely, but also the edge portion can be easily formed. is there.

In a general manufacturing method of the single-sided molding method, first, a male mold for transferring a base curve surface and a female mold for forming a cavity in combination with the male mold are formed by injection molding or the like. Next, after injecting the polymerizable monomer into the female mold, the male mold is combined with the female mold, and the lens-shaped cavity between these molds is filled with the polymerizable monomer, and the polymerizable monomer is polymerized by heat or ultraviolet rays. To produce semi-finished lenses. After polymerization is completed, remove the female mold or attach the female mold as it is, attach the male mold with the semi-finished lens attached to the lathe for lens cutting, cut and polish the semi-finished lens to create a front curve surface And get a contact lens. After cleaning the contact lens surface with the contact lens obtained on the male mold attached,
Hydrate with water or saline, then
Manually remove the swollen contact lens from the male mold. Then, extraction and replacement with physiological saline are performed to complete a soft contact lens.

[0010]

However, in the single-sided molding method, it is necessary to perform cutting and polishing in a state where the semi-finished lens is adhered to the male mold. The surface of the male mold is treated so that the semi-finished lens product does not peel off from the male mold due to stress, or a resin having good adhesiveness to the lens material is used as the male mold material. Therefore, the contact lens adheres firmly to the male mold, and it is difficult to separate the contact lens from the male mold. At present, before separation, a process to clean silicon oil and abrasives attached to the contact lens during polishing and a hydration process are provided, and after the contact lens is swollen, the contact lens is manually peeled off from the male mold. Therefore, there are problems that the number of manufacturing steps is large, labor is required, and manufacturing cost is increased.

The present invention has been made in view of the above circumstances, and a method of manufacturing a soft contact lens that can easily separate a contact lens from a male mold and reduce the number of production steps in a single-sided molding method. The purpose is to provide.

[0012]

The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, after cutting and polishing, the contact lens is made of, for example, ethylene-vinyl alcohol copolymer having good adhesiveness to the lens material. In the state of firmly adhering to the male mold composed of coalescing, preferably by immersion treatment in an aqueous alcohol solution, more preferably ethanol or isopropyl alcohol, the contact lens spontaneously peels off from the male mold in the solution Swelling, whereby it was found that demolding and hydration can be performed quickly, and the present invention has been accomplished.

Accordingly, the invention according to claim 1 comprises a step of combining a male mold and a female mold and filling a gap between them with a polymerizable monomer, and polymerizing the polymerizable monomer filled in the gap to form a lens. A step of manufacturing a semi-finished product, and a step of forming a contact lens by removing the female mold or removing the semi-finished lens attached to the male mold with the female mold attached to the male mold. And separating the male mold and the contact lens attached to the male mold with a hydrophilic organic solvent or an aqueous solution thereof. Further, the invention according to claim 2 provides a method for producing a contact lens according to the method for producing a contact lens according to claim 1, wherein a surfactant is blended into the hydrophilic organic solvent or an aqueous solution thereof. I do.

Further, the invention according to claim 3 provides the method for manufacturing a soft contact lens according to claim 1 or 2, wherein the hydrophilic organic solvent is alcohol. I do.

Further, the invention according to claim 4 provides a method for manufacturing a soft contact lens according to claim 3, wherein the alcohol is ethanol or isopropyl alcohol.

Further, the invention described in claim 5 is the same as that in claim 1.
4. The method for producing a soft contact lens according to any one of 4), wherein the male mold is composed of an ethylene-vinyl alcohol copolymer.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be specifically described, but the present invention is not limited to the following embodiments.

As described above, the method for producing a soft contact lens according to the present invention includes a step of combining a male mold and a female mold and filling a space between them with a polymerizable monomer.

FIG. 1 shows an embodiment of a male type and a female type. FIG. 1A shows a male mold 1 and FIG. 1B shows a female mold 2. The male mold 1 is made of resin and has a base curve optical surface 11 for directly transferring a base curve of a contact lens, and a projection on the outer periphery of the base curve optical surface, which forms a liquid reservoir in cooperation with the female mold 2. A ring-shaped abutment surface 13 is provided on the outer peripheral side of the portion 12 and the protrusion 12. Further, a cylindrical attachment 14 is provided on the rear surface side, and after molding, the attachment 14 can be attached to a lathe for cutting a lens with the attachment 14.

On the other hand, the female die 2 is made of resin and has a concave surface 21 forming a cavity. The female die 2 is connected to an edge of the concave surface 21 and has a contact surface 22 which comes into contact with the abutting surface 13 of the male die 1 when assembled. Prepare.

The male mold 1 and the female mold 2 can be formed, for example, by injection molding, respectively. As a resin that can be used, it has good molding accuracy, is not modified by monomers, does not adversely affect polymerization, has good heat resistance in consideration of thermosetting, and is cut with the lens material,
A cuttable resin is preferred. Furthermore, in the male mold 1, since it is necessary to hold the lens material while the lens material is cut, it is preferable that the adhesion to the lens material is good, and furthermore, it is easily separated from the lens by hydration with water or the like. It is preferable that the releasability is good. From these conditions, polyamide, ethylene-vinyl alcohol copolymer, polyacetal, polyester, polysulfone, polyolefin and the like can be exemplified. Among them, the male-type 1 is preferably an ethylene-vinyl alcohol copolymer having an excellent balance of adhesiveness, releasability, solvent resistance and transferability.

FIG. 2 shows a state in which a mold is formed by combining the male mold 1 and the female mold 2. Male mold 1 convex surface 1
A lens-shaped gap 3 is formed between the first mold 1 and the concave surface 21 of the female mold 2, and this gap 3 is a cavity for molding a semi-finished lens product. The thickness of the cavity 3 is 2 to 20 times the thickness required for a contact lens, particularly 5 to 10 times.
It is preferable to have about twice the thickness. A liquid reservoir 4 is formed on the outer periphery of the cavity 3.

In order to fill the cavity 3 with the polymerizable monomer, for example, a liquid monomer is poured into the concave surface 21 with the concave surface 21 of the female die 2 facing upward, and then the male die 1 is placed over the female die 2. Combine as shown in 2. At this time, the amount of the monomer is slightly larger than the capacity of the gap 3 so that the monomer overflows from the gap 3 and accumulates in the liquid reservoir 4.

The polymerizable monomer applicable to the present invention is a commonly used radically polymerizable compound, and is a compound containing at least one vinyl group, allyl group, acryl group or methacryl group in the molecule. It is a substance usually used as a soft contact lens material. Specifically, alkyl (meth) acrylate, siloxanyl (meth) acrylate, fluoroalkyl (meth) acrylate, hydroxyalkyl (meth) acrylate, polyethylene glycol (meth) acrylate, (meth) acrylate of polyhydric alcohol, vinyl (Meth) acrylates such as (meth) acrylates, derivatives of styrene, N-vinyllactam, vinyl compounds such as vinyl (poly) carboxylate, fluoroalkyl (meth) acrylate, organosiloxanyl (meth) acrylate And the like. More specifically, for example, styrene, acrylic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate, phenyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, n- Butyl methacrylate, 2-ethylhexyl methacrylate, isobornyl methacrylate, benzyl methacrylate, phenyl methacrylate, 2-methacryloyloxyethyl succinic acid, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, fumaric acid and their Esters, methacrylonitrile, N, N-dimethylacrylamide, N-vinyl-2-pyrrolidone, 2, , 2-trifluoroethyl methacrylate, tris (trimethylsiloxy) silyl propyl methacrylate.

Further, as crosslinking agents, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate
Acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, 1,4-butanediol di (meth) acrylate,
Polyfunctional monomers such as 1,6-hexanediol di (meth) acrylate, glycerin di (meth) acrylate, divinylbenzene diallyl phthalate, and diethylene glycol bisallyl carbonate can also be used.

The characteristics of these polymerizable monomers used,
In other words, it is necessary to select a suitable polymerization method, a type of polymerization initiator, an added amount, and the like in consideration of viscosity, volume shrinkage, polymerization rate, and the like.

Examples of the polymerization initiator include azobisisobutyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile), benzoyl peroxide, lauryl peroxide, and diisopropyl peroxycarbonate. . The amount of the polymerization initiator to be added is about 0.01 to 3% by weight based on the total amount of the monomers.

Next, in the method for producing a contact lens according to the present invention, the polymerizable monomer filled in the space 3 is polymerized.
The polymerization method in this case is not limited, and may be either thermal polymerization or photopolymerization such as ultraviolet light. In this way, it is possible to obtain a semi-finished lens in which the base curve surface is formed by the male mold 2 and the convex surface forming the front curve is thicker than the intended contact lens.

Next, the method for manufacturing a soft contact lens according to the present invention is a method of manufacturing a soft contact lens according to the present invention, in which the semifinished lens attached to the male mold 1 is attached to the male mold 1 with or without removing the female mold 2. Cut to form contact lenses.

Preferably, after removing the female mold 2, the female mold 2 is fixed to a lathe for cutting a lens using the attachment 14 of the male mold 1, and as shown in FIG. , Forming the front curve of the contact lens. Thereafter, polishing is performed using a polishing liquid or the like in which a polishing agent is suspended in silicon oil to obtain a contact lens having a predetermined power. If the male mold 1 is formed of an ethylene-vinyl alcohol copolymer, the semifinished lens product 6 can be stably cut and polished without peeling off from the male mold 1 during the cutting and polishing steps.

The contact lens thus obtained is firmly adhered to the male mold 1 in a dry state, and dirt such as silicon oil and abrasive used for polishing is adhered to the surface.

Next, an immersion treatment step of separating the male mold and the contact lens, which is a feature of the present invention, with a hydrophilic organic solvent or an aqueous solution thereof is performed.

The contact lens may be washed as a pre-treatment of the releasing step. For example, it can be washed by immersing it in an aqueous solution or an organic solvent containing a surfactant such as a nonionic surfactant described below and applying ultrasonic waves.

The immersion step can be performed by immersing the contact lens 7 attached to the male mold 1 in a hydrophilic organic solvent or an aqueous solution thereof, as shown in FIG.

The hydrophilic organic solvent used for the immersion treatment is not specified, but is preferably selected in consideration of the safety for the human body, the influence on the contact lens, and the high permeability to the lens. Examples of the hydrophilic organic solvent include water-soluble alcohols such as ethanol and isopropyl alcohol, acetone, tetrahydrofuran and the like. Among them, water-soluble alcohols such as ethanol and isopropyl alcohol are suitable because they cause little harm to the human body, are easy to remove, have high penetration into lenses, and have little effect on soft contact lenses in general. These can be used alone or in combination of two or more. The blending amount of the hydrophilic organic solvent is not particularly limited, but the swelling speed differs depending on the type of the contact lens, so that the concentration suitable for the lens should be selected. For example, in the immersion treatment of the HEMA lens using ethanol, the time until spontaneous peeling becomes the shortest when the blending amount is 40% to 80%. Also,
By using an ultrasonic cleaner, the penetrating power can be increased and the processing time can be shortened.

By the immersion treatment, the contact lens 7 is naturally separated from the male mold 1 in a short time and hydrated. The contact lens swells and expands in volume to about 1 to 3 times. It is considered that spontaneous peeling occurs due to the high permeability of the hydrophilic organic solvent and distortion due to this expansion. By replacing the solution in the contact lens with water or saline, the shape of the contact lens returns to normal.

As water used for dissolving the hydrophilic organic solvent, pure water is preferably used because it also serves as hydration of the contact lens.

The hydration and demolding steps of the contact lens can be performed by a short-time immersion treatment with an organic solvent or an aqueous solution thereof, and the manufacturing time can be greatly reduced. In addition, as compared with a case where the contact lens is manually separated from the male mold, defects such as blurring and scratches are reduced. In addition, since the contact lens can be reliably separated from the male mold, the male mold 1 can be formed using a resin having good adhesiveness, whereby the semi-finished lens product is separated from the male mold in the cutting and polishing steps. The risk can be further reduced.

In the immersion treatment of the hydrophilic organic solvent or the aqueous solution thereof, a surfactant may be added to the hydrophilic organic solvent or the aqueous solution thereof. Incorporation of a surfactant shortens the time required for peeling off the lens, and may not require pre-cleaning. The surfactant used for the pre-cleaning or immersion treatment is not particularly limited, and anionic surfactants, cationic surfactants, and nonionic surfactants can be used. It is preferable to use a nonionic surfactant in consideration of the influence on the surface. Examples of the nonionic surfactant include poly (oxyethylene) -poly (oxypropylene) block copolymer, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, and polyoxyethylene sorbitan alkyl. Esters, polyoxyethylene hydrogenated castor oil, fatty acid monoglycerides, propylene glycol fatty acid esters, fatty acid sucrose esters, poly (oxyethylene) -poly (oxypropylene) ethylenediamine condensates, and the like.
The species can be used alone or in combination of two or more.

The amount of the surfactant is from 0.01% by weight to
It is preferable to set the range up to the solubility in the solution, particularly 0.05 to 5%. By setting it in this range, both economic efficiency and sufficient detergency can be achieved.
Further, when ultrasonic waves are used together, the release can be further accelerated.

The contact lens released from the male mold, washed and hydrated is then completed as a contact lens in an extraction / replacement step. This extraction / replacement step is a step of extracting unpolymerized monomers from the contact lens and replacing the water inside the contact lens with physiological saline, and the contact lens is replaced with a solution containing the above-mentioned hydrophilic organic solvent. When the mold is released, it also has a role of removing the hydrophilic organic solvent in the contact lens.

The extraction and replacement can be carried out, for example, by placing a contact lens in a physiological saline solution and in an autoclave at 121 ° C. for 2 hours.

According to such a method of manufacturing a contact lens, the semi-finished lens is cut while being attached to the male mold.
The release of the contact lens from the male mold, which is a problem in the single-sided mold method for polishing, can be reliably performed in a short time without damaging the contact lens, and the manufacturing cost can be reduced.

[0044]

EXAMPLES Example 1 A male mold 1 was molded from an ethylene-vinyl alcohol copolymer, and a female mold 2 was molded from polypropylene. As the polymerizable monomer, 2-hydroxyethyl methacrylate (99% by weight), ethylene glycol dimethacrylate (0.4% by weight), 2,2'-azobis (2,
After thoroughly mixing 0.3% by weight of 4-dimethylvaleronitrile), the mixture was prepared by repeating degassing and purging with nitrogen.

The polymerizable monomer (0.22 g) was discharged into the female mold 2, and the male mold 1 was slowly lowered from directly above the male mold 1.
And the female mold 2 were assembled as shown in FIG. Put the assembled resin mold into a hot-air circulation type thermostat,
The temperature was raised to 70 ° C over 1 hour, and then at 70 ° C for 2 hours.
The mixture was heated at 00 ° C. for 2 hours for polymerization. Thereafter, the attachment 14 of the male mold 1 to which the semi-finished lens was adhered was attached to a lathe for cutting a lens, and the curvature on the front curve side was 7.
It was cut and polished at 7 mm. Further, an edge portion was formed by cutting so that the outer peripheral defining portion of the lens had a smooth curved shape. Further, polishing was performed using a polishing liquid in which a polishing slurry was suspended in silicon oil.

The obtained contact lens in a dry state is immersed in an aqueous solution in which 1% by weight of a nonionic surfactant Newpole PE-108 (manufactured by Sanyo Chemical Industries, Ltd.) is dissolved, and the resultant is placed in an ultrasonic cleaner. For 1 minute. After removing the cleaning solution, each was immersed in a 20% to 100% aqueous ethanol solution. As shown in FIG. 4, the contact lens 7 was spontaneously peeled off from the male mold 1. The time from the start of immersion in each concentration of ethanol aqueous solution to spontaneous peeling is 15 minutes at 20% ethanol concentration, 5 minutes at 40% and 60% ethanol,
It was 6 minutes at 80% and 21 minutes at 100%. It should be noted that it took 74 minutes for the lens immersed in pure water to be released by applying ultrasonic waves in the same manner.

The swollen contact lens 7 was immersed in physiological saline to replace the liquid in the lens and complete elution of the eluate. The lens did not require cleaning, and the shape and strength were not different from those of hot water peeling.

Example 2 A male mold 1 was molded from an ethylene vinyl alcohol copolymer, and a female mold 2 was molded from polypropylene. As the polymerizable monomer, 70% by weight of 2,2,2-trifluoroethyl methacrylate, 10% by weight of tris (trimethylsiloxy) silylpropyl methacrylate, 3.5% by weight of 2-hydroxyethyl methacrylate, 1% by weight of ethylene glycol dimethacrylate ,
After 0.5% by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) was mixed well, the mixture was prepared by repeating degassing and purging with nitrogen.

0.35 g of the polymerizable monomer was discharged into the female mold 2, and the male mold 1 was assembled there in the same manner as in the embodiment, and polymerized.
After cutting and polishing, a dry contact lens was obtained.

The obtained contact lens in a dry state is immersed in an aqueous solution in which 1% by weight of a nonionic surfactant Newpole PE-108 (manufactured by Sanyo Chemical Industries, Ltd.) is dissolved, and the resultant is placed in an ultrasonic cleaner. For 1 minute. After removing the washing solution, the substrate was immersed in a 20% to 100% by volume aqueous ethanol solution. As shown in FIG. 4, the contact lens was spontaneously peeled off from the male mold 1. The time from the start of immersion in the aqueous ethanol solution of each concentration to spontaneous peeling was 16 minutes at an ethanol concentration of 40%, 5 minutes at 60%, 2 minutes at 80%, and 100 minutes at 100%.
% Was 1 minute. In addition, it took 90 minutes for the lens which had been immersed in pure water to be released by applying ultrasonic waves.

The swollen contact lens 7 was immersed in physiological saline to replace the solution and complete elution of the eluted material. The lens did not require cleaning, and the shape and strength were not different from those of hot water peeling.

Example 3 A male mold 1 was molded from an ethylene vinyl alcohol copolymer, and a female mold 2 was molded from polypropylene. As the polymerizable monomer, 70% by weight of 2,2,2-trifluoroethyl methacrylate, 10% by weight of tris (trimethylsiloxy) silylpropyl methacrylate, 3.5% by weight of 2-hydroxyethyl methacrylate, 1% by weight of ethylene glycol dimethacrylate ,
After 0.5% by weight of 2,2′-azobis (2,4-dimethylvaleronitrile) was mixed well, the mixture was prepared by repeating degassing and purging with nitrogen.

0.35 g of the polymerizable monomer was discharged into the female mold 2, and the male mold 1 was assembled in the same manner as in the example, and polymerized.
After cutting and polishing, a dry contact lens was obtained.

The obtained dry contact lens was mixed with 0.25% by weight of a nonionic surfactant Newpole PE-108 (manufactured by Sanyo Chemical Industries, Ltd.) at 40%.
And 60% isopropyl alcohol aqueous solution. The time from the start of immersion in each immersion treatment solution to spontaneous peeling was 13 minutes at 40% and 5 minutes at 60%. As shown in FIG. 4, the contact lens was spontaneously peeled off from the male mold 1. The lens immersed in pure water similarly took 105 minutes to release the mold by applying ultrasonic waves, and it took 20 minutes for 40% isopropyl alcohol and 7 minutes for 60% isopropyl alcohol using only the aqueous solution.

The swollen contact lens 7 was immersed in physiological saline to replace the solution and complete elution of the eluted material. The lens did not require cleaning, and the shape and strength were not different from those of hot water peeling.

[0056]

According to the method for manufacturing a soft contact lens of the present invention, it is possible to extremely quickly and reliably remove a difficult mold from a resin mold in a one-sided molding method in which cutting and polishing are performed while being adhered to the resin mold. At the same time, costs can be reduced by reducing the number of steps.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a resin mold used in a method for manufacturing a soft contact lens of the present invention, wherein (a) is a male mold,
(B) shows a female mold.

FIG. 2 is a sectional view showing a state where the male mold and the female mold of FIG. 1 are combined.

FIG. 3 is a cross-sectional view showing a state in which a semi-finished lens attached to the male mold is being cut.

FIG. 4 is a cross-sectional view showing a state in which a contact lens is naturally separated from a resin mold in a hydrophilic organic solvent or an aqueous solution thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Male type 11 ... Base curve optical surface (convex surface) 12 ... Projection part 13 ... Butt surface 14 ... Attachment 2 ... Female type 21 ... Concave surface 3 ... Void (cavity) 4 ... Liquid storage part 5 ... Bit 6 ... Lens half Finished product 7: Contact lens S: Hydrophilic organic solvent or its aqueous solution

Claims (5)

[Claims] 1. A step of combining a male mold and a female mold and filling a gap between them with a polymerizable monomer, and a step of polymerizing the polymerizable monomer filled in the gap to produce a semi-finished lens product. Removing the female mold or removing the semifinished lens attached to the male mold with the male mold attached to the male mold to form a contact lens; and forming the contact lens with the male mold and the male. Separating the contact lens from the mold in a hydrophilic organic solvent or an aqueous solution thereof. 2. The method for manufacturing a contact lens according to claim 1, wherein a surfactant is blended into the hydrophilic organic solvent or an aqueous solution thereof. 3. The method for producing a soft contact lens according to claim 1, wherein the hydrophilic organic solvent is an alcohol. 4. The method for producing a soft contact lens according to claim 3, wherein the alcohol is ethanol or isopropyl alcohol. 5. The method for producing a soft contact lens according to claim 1, wherein said male mold is made of an ethylene-vinyl alcohol copolymer. .