JPH05337957A - Production of contact lens and mold used therein - Google Patents

Abstract

PURPOSE:To obtain an optical excellent contact lens of high quality free from eccentricity by constituting a male mold and a female mold of the same mold and providing a protruding molding surface and a recessed molding surface to one mold and filling the space becoming a lens shape formed by matching the molds each other with a polymerizable monomer to polymerize the monomer. CONSTITUTION:A lens mold is constituted of a recessed FC optical surface 1 forming FC when a contact lens shape is molded, a protruding BC optical surface 2 forming BC when the contact lens shape is molded, the contact surface 4 of the mold becoming a contact state when molds are matched after the filling with a polymerizable monomer to determine the thickness of the contact lens and a side surface part contact surface 5 of the mold becoming a contact state when the molds are matched after the filling with the polymerizable monomer to prevent the positional shift of the FC surface and the BC surface. Two molds are matched and assembled to form a space 6 which is, in turn, filled with the polymerizable monomer and this monomer is polymerized to obtain the contact lens. When the eccentricity of the FC optical surface and the BC optical surface is eliminated, the eccentricity of the lens is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a high-quality contact lens having excellent optical properties and having a smooth surface which does not damage the cornea, and a mold used therefor. Furthermore, the present invention relates to a method for manufacturing a low-cost contact lens applicable to disposable contact lenses.

[0002]

2. Description of the Related Art Contact lenses can be roughly classified into two types, hard contact lenses and soft contact lenses. Further, soft contact lenses can be classified into water-containing soft contact lenses used in a state swollen with water and non-water-containing soft contact lenses containing no water. Each of these contact lenses has advantages and disadvantages, and the contact lens wearer selects and uses a lens suitable for himself or herself from these.

On the other hand, there are roughly three types of contact lens manufacturing methods, which are a race cut method (cutting and polishing method),
It is manufactured by either a molding method or a spin casting method (centrifugal casting method). The lace cut method is
This is the most commonly used method for manufacturing contact lenses at present, and is a method for manufacturing contact lenses by cutting out a rod-shaped or button-shaped contact lens material with a lathe, cutting and polishing. This method is BC
(Base curve: the surface where the contact lens contacts the cornea,
(Or the curvature of the surface) is a suitable method for manufacturing various types of contact lenses with different shapes, and it is easy to process the edge part, which is an important factor that determines the wearing feeling of the lens. Although it is possible, it is difficult to obtain surface accuracy, and there are drawbacks such as variations in quality. Further, there is a problem that the cost is very high, so it is very difficult to use this method as a method for manufacturing disposable contact lenses. .. Currently, most hard contact lenses are manufactured by this lace cut method,
Many manufacturers also manufacture soft contact lenses using the lace cut method.

On the other hand, most of the molding method and spin casting method are used in the manufacture of soft contact lenses. The molding method is a method of filling a mold having a lens-shaped space with a polymerizable monomer and polymerizing this to manufacture a contact lens. In this method, both dimensional accuracy and surface accuracy are greatly affected by the accuracy of the mold,
Although it is possible to manufacture a high quality contact lens at a relatively low cost by using an accurate mold, it is difficult to manufacture a variety of contact lenses having different shapes. The spin casting method is a method of manufacturing a contact lens by using a method in which a polymerizable monomer is poured into a rotating mold and a raw material is spread thinly by a centrifugal force. This method also has an advantage that a contact lens can be manufactured at a low cost similarly to the molding method. However, the spin casting method needs to control many factors such as the viscosity, surface tension, amount, and rotation speed of the polymerizable monomer, and the applicable lens material is limited to a particular lens material. Further, the contact lens obtained by this method has an aspherical surface, so that not only sufficient optical performance is not obtained, but also the edge portion is difficult to process.

In recent years, soft contact lenses have been widely used by people who have not been able to wear conventional hard contact lenses because of their good wearing comfort. Soft contact lenses do not require as many BC types as hard contact lenses because they are flexible and fit along the corneal shape. Therefore, the molding method is suitable for manufacturing a contact lens with low cost and high quality. In addition, since a soft material such as a silicone rubber or a long-chain alkylmethacrylate that does not contain water, such as a soft contact lens, cannot be processed by the race cut method, it is generally manufactured by the molding method.

Although a technique of manufacturing a contact lens by a molding method is already known, it is necessary to perform post-processing after manufacturing a contact lens by the molding method in order to improve the optical performance and wearing feeling of the obtained contact lens. Various efforts have been made by researchers and engineers in the past to prevent such problems, and a great many technologies have been developed for contact lens manufacturing methods and molding dies used therefor. Was
It is disclosed in patents and the like.

For example, as a technique for obtaining a contact lens by filling a contact lens material into a space formed when a male mold and a female mold are matched, Japanese Patent Publication No. 63-36484 discloses a method of manufacturing a contact lens by a molding method. A method for preventing burrs that tend to occur at the time and not requiring post-processing is disclosed in Japanese Patent Laid-Open No. 61-290012 by providing a space for adjusting the amount of lens material so as to be connected to a lens forming space of a mold. A method for preventing the formation of burrs and eliminating the need for post-processing is disclosed in Japanese Patent Laid-Open No. 172712/1990 by putting a male mold and a female mold into a rear pressure vessel and pressing the same to press the outer peripheral portion of the lens. A method for preventing the occurrence of burrs and requiring no post-processing is disclosed in Japanese Patent Application Laid-Open No. 1-92719 as a method for similarly preventing burrs. That.

Further, as a technique for obtaining a contact lens by inserting a spacer between a male mold and a female mold and filling a space formed when the spacers are fitted with a contact lens material, Japanese Patent Publication No. 55-26446. Is a method of providing an annular spacer in order to form a space corresponding to a desired lens shape. Similarly, as a method of using a spacer, JP-A-62-297119 and JP-A-62-2971 are known.
No. 20, etc.

Further, as a method using a molding method, Japanese Patent Laid-Open No. 59-95118 discloses that a contact lens material is sandwiched between a male mold and a female mold, and the peripheral portion of the lens material is covered with the mold. Japanese Patent Laid-Open No. 60-73836 discloses a method of machining a lens with a mold in which the convex surface of the lens material is machined together with the contact lens material sandwiched between the molds. Similarly, a method using a combination of the molding method and machining is disclosed in Japanese Patent Application Laid-Open No. 63-3910.

[0010]

The greatest advantage of manufacturing contact lenses by the molding method is that contact lenses of the same standard can be manufactured in large quantities and can be manufactured at low cost.

In recent years, cleaning of soft contact lenses,
Disposable soft contact lenses are rapidly becoming popular mainly in the United States because they do not require troublesome care such as boiling disinfection and are hygienic.
In order to manufacture this disposable soft contact lens, it is necessary to significantly reduce the conventional manufacturing cost, but the quality cannot be deteriorated because the contact lens is a medical device that directly contacts the cornea.

As a method for producing a low-cost, high-quality contact lens applicable to these disposable contact lenses, JP-A-59-95118, JP-A-60-73836, and JP-A-63-3910 are known. The manufacturing method of the contact lens described is polymerized into a lens shape or a button shape by a molding method and then manufactured by machining, so that a contact lens having an excellent quality such as a smooth edge portion can be obtained.
It has the disadvantage of high cost because it requires machining.

On the other hand, JP-B-55-26446, JP-A-62-297119, and JP-A-62-2971.
The method of manufacturing a contact lens described in Japanese Patent Publication No. 20 is a method of obtaining a contact lens by inserting a spacer between a male mold and a female mold and filling a space formed when the spacers are fitted with a contact lens material. This is a device for smoothing the edge shape and eliminating the need for secondary processing, and for preventing burrs from occurring on the outer peripheral portion of the lens, but this increases the types of molds, leading to an increase in cost.

Optical performance is one of the important qualities required for contact lenses. When a contact lens is manufactured by a molding method, the surface accuracy and shape accuracy of the contact lens greatly depend on the accuracy of the mold. Therefore, a high-quality contact lens can be obtained by using a high-precision mold. However, as a characteristic of the molding method, since a male mold and a female mold are combined and polymerized in the space formed therebetween, a slight inclination of the mold directly affects the optical performance. That is, if the mold dimensions are slightly misaligned, or if the male and female molds are not in complete contact when mated, the thickness of the space formed between the male and female molds Difference (thickness of the contact lens) occurs, and the focal point of the contact lens obtained by this difference deviates from the optical axis, and the influence occurs in the form of a prism of the lens. This phenomenon is called lens eccentricity. When wearing a contact lens with eccentricity, the human eye has an adjusting function to try to correct the deviation of the optical axis, and wearing a contact lens with this eccentricity for a long time causes headaches and other symptoms. Will appear. This eccentricity phenomenon is particularly likely to occur in the method of obtaining a contact lens by inserting a spacer between the male mold and the female mold and filling the space formed when the spacers are fitted with a contact lens material. This is because it is necessary to process not only the male and female molds but also the spacers with high precision by adding one part called the spacer, and when matching the male mold and the spacer and the spacer and the female mold, This is because the contact state must be carefully considered, and the eccentricity phenomenon is apt to occur in the conventional method of flow work using a human hand or a machine.

The molding die for manufacturing a contact lens disclosed in Japanese Patent Publication No. 63-36484 has two parts, a male mold and a female mold, and the shape of the edge portion of the lens is devised to prevent burrs from occurring. In addition, however, this molding die has a drawback that the contact surface between the male die and the female die is very narrow, it is relatively difficult to obtain the accuracy of the lens thickness, and eccentricity is likely to occur. In the methods described in JP-A-61-290012, JP-A-1-92719, and JP-A-2-172712, since the male mold and the female mold are separate parts, it is possible to eliminate this eccentricity. It can be said to be very difficult.

The problems with the current contact lens manufacturing method and the advantages and problems of manufacturing a contact lens using the molding method have been described above. However, the present invention provides optical performance without decentration. With a focus on producing excellent and high-quality contact lenses, it aims to produce low-cost contact lenses that have a smooth surface that does not damage the cornea and that can also be applied to disposable contact lenses. It is what

[0017]

That is, the method for producing a contact lens of the present invention is configured so that a lens-shaped space is formed when a male mold and a female mold are matched, and the space is superposed. In the method of manufacturing a contact lens by filling a monomer, the male mold and the female mold are made of the same mold, and one mold has a convex molding surface and a concave molding surface. The present invention is characterized in that a space is formed into a lens shape when they are matched with each other and a polymerizable monomer is filled and polymerized to obtain a contact lens.

The mold used for producing the contact lens of the present invention is constructed so that a lens-shaped space is formed when the male mold and the female mold are fitted, and a polymerizable monomer is placed in the space. A mold used in a method of manufacturing a contact lens by filling, wherein the male mold and the female mold are made of the same mold, and one mold has a convex molding surface and a concave molding surface. is there.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a front view of a contact lens mold according to the present invention, FIG. 2 is a cross-sectional view, and FIG. 3 is an assembled cross-sectional view showing a combined state of the contact lens mold according to the present invention.

The contact lens mold of the present invention is shown in FIG.
As shown in Fig. 3, when the lens is molded into a contact lens shape, FC (front curve: the surface opposite to the surface where the contact lens contacts the cornea, or the curvature of that surface) is formed as a concave FC optical surface 1, the contact lens. The convex BC optical surface 2 that forms BC when molded into a shape, the contact surface 4 of the mold that determines the lens thickness when the mold is matched after filling the polymerizable monomer, and the polymerizable monomer. When the molds are matched after filling, they come into contact with each other and FC face and BC
It is composed of a side surface contact surface 5 of a mold that prevents the surface position from deviating.

When the two molds are matched and assembled, FIG.
As shown in FIG. 3, a lens-shaped space (cavity) 6 is formed between the FC optical surface and the BC optical surface, and a polymerizable monomer is filled in the cavity and polymerized to obtain a contact lens. Of. The space 7 formed when the two molds are matched is a space for allowing air to escape when the mold is filled with the polymerizable monomer and assembled.

As can be seen from the drawings, the contact lens mold according to the present invention has the same male mold and female mold, and one mold has a convex molding surface and a concave molding surface. Therefore, if the eccentricity of the FC optical surface and the BC optical surface of the mold is eliminated in manufacturing the mold, the eccentricity of the contact lens molded thereby is virtually eliminated. Further, since the male mold and the female mold are made of the same mold, it is possible to further reduce the manufacturing cost by stacking the molds in multiple stages and simultaneously polymerizing them.
Another advantage is that the number of types used can be reduced.

Next, the production of the molding die will be described. As the material of the molding die of the present invention, materials generally used as molding materials such as metal, ceramics and plastics can be applied. In particular, by using thermoplastics and applying methods that are commonly used for molding plastics, such as injection molding, injection compression molding, and compression molding, a highly accurate molding die can be manufactured at low cost. It can be manufactured. Further, when plastic is used as the material of the molding die, by disposing the molding die as a disposable, the step of cleaning the mold can be omitted, and the contact lens can be manufactured with extremely high productivity.

Examples of thermoplastics that can be used as the material for the mold include polyolefins such as polyethylene and polypropylene, polystyrene, polytetrafluoroethylene, polycarbonate, polyacetal, polyphenylene oxide, polysulfone, polyamide and the like. Among these plastics, the contact lens polymerization method, polymerizable monomer type, cost, etc., and various physical properties of the plastic such as light transmittance, heat resistance, solvent resistance, mechanical properties (viscoelasticity, etc.), molding The mold material that is most suitable for the intended contact lens production is selected in consideration of the characteristics.

Next, the method for polymerizing the contact lens according to the present invention will be described. The polymerization of the present invention is carried out by heating or irradiation with active energy rays such as ultraviolet rays in the presence of a usual polymerization initiator. A necessary amount of the polymerizable monomer is discharged onto the concave molding surface of the molding die, and another molding die is superposed thereon so that the convex molding surface matches the concave molding surface. At this time, be careful that the contact surface of the mold and the contact surface of the side surface are in complete contact. When the molds are superposed and polymerized, this operation is repeated to fill the molds with the polymerizable monomer. It is suitable to heat the thus assembled mold for thermal polymerization or to irradiate with ultraviolet rays to perform photopolymerization.

The polymerizable monomer applicable to the present invention is
A commonly used radically polymerizable compound,
It is a compound containing at least one vinyl group, allyl group, acryl group, or methacryl group in the molecule, and is a substance usually used as a hard contact lens or a soft contact lens material. Specifically, alkyl (meth)
(Meth) such as acrylate, siloxanyl (meth) acrylate, fluoroalkyl (meth) acrylate, hydroxyalkyl (meth) acrylate, polyethylene glycol (meth) acrylate, (meth) acrylic acid ester of polyhydric alcohol, vinyl (meth) acrylate Examples thereof include acrylic acid esters, styrene derivatives, N-vinyl lactam, vinyl compounds such as vinyl (polyvalent) carboxylate, 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-
Examples thereof include hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, fumaric acid and esters thereof, methacrylonitrile, N, N-dimethylacrylamide, N-vinyl-2-pyrrolidone and the like.

Further, as a cross-linking agent, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth)
Acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, 1,4-butanediol di (meth) acrylate,
It is also possible to use polyfunctional monomers such as 1,6-hexanediol di (meth) acrylate, glycerin di (meth) acrylate, divinylbenzene diallyl phthalate, and diethylene glycol bisallyl carbonate.

The characteristics of these polymerizable monomers used,
That is, it is necessary to select a suitable polymerization method, type of polymerization initiator, addition amount, etc. in consideration of viscosity, volume shrinkage, polymerization rate, and the like.

[0030]

The method of manufacturing a contact lens according to the present invention and the molding die used therefor are characterized in that the male mold and the female mold are made of the same mold, and one mold has a convex molding surface and a concave molding surface. We manufacture a high quality contact lens with excellent optical performance without eccentricity by filling the space in the lens shape that is formed when this type is matched with a polymerizable monomer and polymerizing this to obtain a contact lens. Furthermore, it is possible to manufacture a low-cost contact lens that has a smooth surface that does not damage the cornea and that is also applicable to disposable contact lenses.

[0031]

[Examples] The present invention will be described in more detail with reference to the following examples.
The present invention is not limited to these.

Example 1 In this example, molding was performed by injection molding with a BC optical surface curvature of 7.25 mm, an FC optical surface curvature of 7.70 mm, and an optical surface diameter of 11.5 mm shown in FIG. Used mold. Amorphous polyolefin was used as the material of the mold. As the polymerizable monomer, 70 parts by weight of 2,3-dihydroxypropyl methacrylate, 28 parts by weight of methyl methacrylate, 1 part by weight of ethylene glycol dimethacrylate, 2,4,6
-Trimethylbenzoyldiphenylphosphine oxide (0.05 parts by weight) was mixed well, and the mixture was deaerated and replaced with nitrogen. This mixture was filled in the above molding die, and this was irradiated with ultraviolet rays for 100 seconds at a distance of 10 cm using an 80 W / cm high pressure mercury lamp. After swelling the obtained contact lens in pure water and washing,
Immersion in physiological saline was made to absorb a predetermined amount of water, and at the same time, elution of the eluate was completed.

The thus-obtained soft contact lens had a smooth surface, had no voids on the surface and inside of the contact lens, and had no burrs on the outer peripheral portion. The diameter of this soft contact lens is 13.8 mm,
The BC was 8.60 mm, the power was -3.00 D, and no prism was observed.

Example 2 In this example, molding was performed by injection molding with the BC optical surface having a curvature of 6.90 mm, the FC optical surface having a curvature of 7.65 mm and the optical surface having a diameter of 11.5 mm shown in FIG. Used mold. Amorphous polyolefin was used as the material of the mold. As the polymerizable monomer, 2,3-dihydroxypropyl methacrylate 70 parts by weight, methyl methacrylate 28 parts by weight, ethylene glycol dimethacrylate 1 part by weight, 2,4,6
-Trimethylbenzoyldiphenylphosphine oxide (0.05 parts by weight) was mixed well, and the mixture was deaerated and replaced with nitrogen. This mixture was filled in the above molding die, and this was irradiated with ultraviolet rays for 100 seconds at a distance of 10 cm using an 80 W / cm high pressure mercury lamp. After swelling the obtained contact lens in pure water and washing,
Immersion in physiological saline was made to absorb a predetermined amount of water, and at the same time, elution of the eluate was completed.

The soft contact lens thus obtained had a smooth surface, no voids were formed on the contact lens surface and inside, and no burr was generated on the outer peripheral portion. The diameter of this soft contact lens is 13.8 mm,
The BC was 8.20 mm, the power was -8.00 D, and no prism was observed.

(Embodiment 3) In this embodiment, a mold having a BC optical surface curvature of 7.25 mm, an FC optical surface curvature of 7.70 mm and an optical surface diameter of 11.5 mm was used. In addition, polypropylene was used as the material of the molding die. As the polymerizable monomer, 96 parts by weight of 2-hydroxyethyl methacrylate, 2 parts by weight of ethylene glycol dimethacrylate, and 0.05 parts by weight of 2,4,6-trimethylbenzoyldiphenylphosphine oxide were mixed well, and the mixture was degassed, What was nitrogen-substituted was used. This mixture was filled in the above molding die, and this was irradiated with ultraviolet rays for 100 seconds at a distance of 10 cm using an 80 W / cm high pressure mercury lamp. The obtained contact lens was swollen in pure water, washed, and then immersed in physiological saline to absorb a predetermined amount of water, and at the same time, elution of the eluate was completed.

The thus-obtained soft contact lens had a smooth surface, there were no voids on the contact lens surface and inside, and no burr was generated on the outer peripheral portion. The diameter of this soft contact lens is 13.8 mm,
The BC was 8.60 mm, the power was -3.00 D, and no prism was observed.

Example 4 In this example, a mold having a BC optical surface curvature of 7.25 mm, an FC optical surface curvature of 7.70 mm, and an optical surface diameter of 11.5 mm was used. Amorphous polyolefin was used as the material of the mold. As the polymerizable monomer, 96 parts by weight of 2-hydroxyethyl methacrylate, 2 parts by weight of ethylene glycol dimethacrylate, and 0.05 parts by weight of 2,4,6-trimethylbenzoyldiphenylphosphine oxide were mixed well, and the mixture was degassed, What was nitrogen-substituted was used. This mixture was filled in the former mold, and this operation was repeated twice, and the molds were stacked in four stages and fixed with a jig.
A high pressure mercury lamp of 80 W / cm was used for this, and the distance was 10 c.
Ultraviolet light was irradiated for 200 seconds at m. The obtained contact lens was swollen in pure water, washed, and then immersed in physiological saline to absorb a predetermined amount of water, and at the same time, elution of the eluate was completed.

The soft contact lenses thus obtained all had a smooth surface, and there were no voids on the contact lens surface and inside, and no burr was generated on the outer peripheral portion. Further, no prism was observed at all.

(Embodiment 5) In this embodiment, a molding die having a BC optical surface curvature of 7.25 mm, an FC optical surface curvature of 7.85 mm and an optical surface diameter of 11.5 mm was used. In addition, polypropylene was used as the material of the molding die. As the polymerizable monomer, 70 parts by weight of 2,3-dihydroxypropyl methacrylate, 28 parts by weight of methyl methacrylate, 1 part by weight of ethylene glycol dimethacrylate, and 0.2 parts by weight of azobis (2,4-dimethylvaleronitrile) were mixed well. This mixture was used after deaeration and nitrogen replacement. This mixture was filled in the above-mentioned forming die, which was put into a hot air circulation type constant temperature bath and heated at 60 ° C for 10 hours and at 90 ° C for 5 hours. The obtained contact lens was swollen in pure water, washed, and then immersed in physiological saline to absorb a predetermined amount of water, and at the same time, elution of the eluate was completed.

The thus-obtained soft contact lens had a smooth surface, there were no voids on the contact lens surface and inside, and no burr was generated on the outer peripheral portion. Further, no prism was observed at all.

Example 6 In this example, a molding die having a BC optical surface curvature of 7.90 mm, an FC optical surface curvature of 8.15 mm and an optical surface diameter of 8.60 mm was used. In addition, polypropylene was used as the material of the molding die. As the polymerizable monomer, 2,2,2-trifluoroethyl methacrylate 44 parts by weight, tris (trimethylsiloxy)
40 parts by weight of silylpropyl methacrylate, 10 parts by weight of 2-hydroxyethyl methacrylate, 3 parts by weight of ethylene glycol dimethacrylate, and 0.2 parts by weight of 2,4,6-trimethylbenzoyldiphenylphosphine oxide were mixed well, and the mixture was degassed. The one that had been subjected to nitrogen substitution was used. Fill this mixture into the previous mold,
A high pressure mercury lamp of 80 W / cm was used for this, and the distance was 10 c.
Ultraviolet rays were irradiated for 100 seconds at m.

The contact lens thus obtained had a smooth surface, there were no voids on the surface and inside of the contact lens, and no burr was generated on the outer peripheral portion. Further, no prism was observed at all.

[0044]

The contact lens manufacturing method and the molding die used therefor according to the present invention have the same male and female dies, and one die has a convex molding surface and a concave molding surface. To manufacture a high-quality contact lens with excellent optical performance without decentration, because a polymerizable monomer is filled in the lens-shaped space that is formed when this type is matched and this is polymerized to obtain a contact lens. In addition, it is possible to manufacture a low-cost contact lens that has a smooth surface that does not damage the cornea and is applicable to disposable contact lenses.

[Brief description of drawings]

FIG. 1 is a front view of a contact lens manufacturing mold used in Example 1 of the present invention.

FIG. 2 is a cross-sectional view of a contact lens manufacturing mold used in Example 1 of the present invention.

FIG. 3 is an assembled sectional view of a mold for manufacturing a contact lens used in Example 1 of the present invention.

[Explanation of symbols]

 1 FC optical surface 2 BC optical surface 3 Optical surface 4 Type contact surface 5 Type side contact surface 6 Lens-shaped space 7 Air escape space

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical indication location B29L 11:00 4F (72) Inventor Masato Murayama 3-3-5 Yamato, Suwa-shi, Nagano Seiko Epson Within the corporation

Claims (2)

[Claims] 1. A method for producing a contact lens, wherein a space having a lens shape is formed when a male mold and a female mold are matched with each other, and the space is filled with a polymerizable monomer to produce a contact lens. And the female mold are made of the same mold, one mold has a convex molding surface and a concave molding surface, and the polymerizable monomer is present in the lens-shaped space formed when the molds are fitted. A method for producing a contact lens, which comprises filling the mixture with and polymerizing it to obtain a contact lens. 2. A mold used in a method for producing a contact lens, which is configured to form a lens-shaped space when a male mold and a female mold are fitted to each other, and the space is filled with a polymerizable monomer. Yes, the male and female types consist of the same type,
A molding die used for manufacturing a contact lens, wherein one mold has a convex molding surface and a concave molding surface.