JPH06170858A - Production of contact lens and mold therefor - Google Patents

Abstract

PURPOSE:To obtain a contact lens free from decentering, superior in optical characteristics, and applicable to a disposable contact lens by a method wherein a mold having a convex molding surface and a concave molding surface is mated with another mold of the same shape, a monomer is charged into a cavity formed into a lens shape between the molds, and the monomer is polymerized. CONSTITUTION:A mold is provided with a concave FC optical surface 1 for forming an FC in a molded lens and a convex BC oprical surface 2 for forming a BC. By mating this mold with another one, a cavity 6 is formed between the optical surfaces 1, 2. A monomer is delivered on the concave molding surface 1, and thereon the convex molding surface 2 of another mold is overlappedly combined. In this state, the monomer is thermally or optically polymerized. Alternatively, the molds can be overlapped in many stages, and the monomer can be simultaneously polymerized. For the mold, a normal mold material can be used. With the use of a thermoplastic resin as the material, a high- accuracy mold can be made at a low cost, and a mold cleaning process can be eliminated by using it only once and then discarding it.

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 molding die 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 the race cutting 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 a contact lens 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 a wide variety of contact lenses with different shapes such as the edge part, which is an important factor that determines the wearing comfort 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 production 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. This method greatly depends on the accuracy of the mold in terms of dimensional accuracy and surface accuracy,
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 large 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 low cost as in the molding method. However, the spin cast 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 specific one. Further, the contact lens obtained by this method has an aspherical surface, so that not only sufficient optical performance cannot be obtained, but also processing of the edge portion is difficult.

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 a race cut method, it is generally manufactured by a 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 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. Is
It is disclosed in patents and the like.

[0007] 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 with each other, Japanese Patent Publication No. 63-36484 discloses that a contact lens is manufactured 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 a lens material amount 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 post-pressure unit and pressurizing the same into the lens outer peripheral portion. 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.

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 each other, a contact lens is disclosed in JP-B-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., for example.

Further, as a method utilizing a molding method, Japanese Patent Application 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 being sandwiched between the molds. Similarly, a method in which the molding method and the mechanical processing are used in combination is disclosed in JP-A-63-3910.

[0010]

The greatest advantage of manufacturing contact lenses by a molding method is that contact lenses of the same standard can be mass-produced and low-cost production is possible.

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.

Low-cost, high-quality contact lens manufacturing methods applicable to these disposable contact lenses are disclosed in JP-A-59-95118, JP-A-60-73836, and JP-A-63-3910. The manufacturing method of the contact lens described, after being polymerized into a lens shape or a button shape by a molding method, and then manufactured by machining, 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 No. 20 is a method in which a spacer is sandwiched between a male mold and a female mold, and a space formed when the spacers are fitted is filled with a contact lens material to obtain a contact lens. 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 periphery 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 an accurate mold. However, as a characteristic of the molding method, since a male mold and a female mold are combined and polymerized in a space formed therebetween, a slight inclination of the mold directly affects optical performance. That is, if the mold dimensions are slightly misaligned, or when the male and female molds are not in complete contact when mating, the thickness of the space formed between the male and female molds Difference (thickness of the contact lens) occurs partially, and the focus 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 this deviation of the optical axis, and wearing a contact lens with this eccentricity for a long time causes symptoms such as headache. Will appear. This eccentricity phenomenon is particularly likely to occur in the method of obtaining a contact lens by sandwiching 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 eccentricity phenomenon is apt to occur by any conventional method, which is a flow work method using a human hand or a machine.

Further, the molding die for manufacturing a contact lens described 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 in order to prevent the occurrence of burrs. In addition, in this molding die, the contact surface between the male die and the female die is very narrow, and it is relatively difficult to obtain the accuracy of the thickness of the lens, and there is a drawback that 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.

Although 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, the present invention provides optical performance without decentration. With a focus on producing excellent and high-quality contact lenses, the objective is 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 of manufacturing 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 fitted together, and the space has a polymerizing property. 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 a male mold and a female mold are fitted together, and a polymerizable monomer is placed in the space. A mold used for 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 molding die according to the present invention, FIG. 2 is a sectional view, and FIG. 3 is an assembled sectional view showing a coupled state of the contact lens molding die 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: a 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, a 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 thickness of the lens by contact 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 fitted together and assembled, as shown in 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 polymerizable monomer is filled and assembled.

As described above, in the contact lens mold according to the present invention, 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. Therefore, if the eccentricity between the FC optical surface and the BC optical surface of the mold is eliminated when the mold is manufactured, 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 mold, the mold cleaning step can be omitted by making this mold disposable, and the contact lens can be manufactured with extremely high productivity.

Examples of thermoplastics that can be used as the material for the molding die include polyolefins such as polyethylene and polypropylene, polystyrene, polytetrafluoroethylene, polycarbonate, polyacetal, polyphenylene oxide, polysulfone, and polyamide. Among these plastics, the contact lens polymerization method, type of polymerizable monomer, 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 required amount of the polymerizable monomer is discharged onto the concave molding surface of the molding die, and another molding die is superposed on the concave molding surface 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 that is usually used as a hard contact lens or 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 consider the viscosity, the volume shrinkage rate, the polymerization rate, etc., and to select a suitable polymerization method, type of polymerization initiator, addition amount, etc.

[0030]

The method for producing 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 a 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. Further, it is possible to manufacture a low-cost contact lens which has a smooth surface which does not damage the cornea and which is applicable to a disposable contact lens.

[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,
The mixture was thoroughly mixed with 0.05 part by weight of 4,6-trimethylbenzoyldiphenylphosphine oxide, 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 at a distance of 10 cm for 100 seconds 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 soft contact lens thus obtained had a smooth surface and had no voids on the surface and inside of the contact lens, and no burr was generated on the outer peripheral portion. The diameter of this soft contact lens is 13.8m.
m, 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, 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,
The mixture was thoroughly mixed with 0.05 part by weight of 4,6-trimethylbenzoyldiphenylphosphine oxide, 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 at a distance of 10 cm for 100 seconds 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 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 13.8m.
m, BC was 8.20 mm, the power was −8.00 D, and no prism was observed.

(Embodiment 3) In this embodiment, the BC optical surface has a curvature of 7.25 mm and the FC optical surface has a curvature of 7.70 m.
m, a molding die having 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 well mixed, and the mixture was degassed, What was nitrogen-substituted was used. This mixture was filled in the former mold, and 80 W /
Ultraviolet rays were irradiated for 100 seconds at a distance of 10 cm using a 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, 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 13.8m.
m, BC was 8.60 mm, the power was -3.00 D, and no prism was observed.

(Embodiment 4) In this embodiment, the BC optical surface has a curvature of 7.25 mm and the FC optical surface has a curvature of 7.70 m.
m, a molding die having 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 well mixed, 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. This was irradiated with ultraviolet rays at a distance of 10 cm for 200 seconds 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 soft contact lenses thus obtained had smooth surfaces on all three lenses, no voids were formed on the contact lens surface and inside, and no burr was generated on the outer peripheral portion. No prism was observed at all.

(Embodiment 5) In this embodiment, the BC optical surface has a curvature of 7.25 mm and the FC optical surface has a curvature of 7.85 m.
m, a molding die having 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, 2,3-dihydroxypropyl methacrylate 70 parts by weight, methyl methacrylate 2
8 parts by weight, 1 part by weight of ethylene glycol dimethacrylate, azobis (2,4-dimethylvaleronitrile)
2 parts by weight were mixed well, and the mixture was deaerated and replaced with nitrogen to be used. This mixture was filled in the above-mentioned molding die, and this was put into a hot air circulation type constant temperature bath, and the mixture was heated at 60 ° C. for 1 hour.
Heat at 0 ° C. for 5 hours at 90 ° C. 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, no voids were formed on the contact lens surface and inside, and no burr was generated on the outer peripheral portion. No prism was observed at all.

Example 6 In this example, the BC optical surface has a curvature of 7.90 mm and the FC optical surface has a curvature of 8.15 m.
m, and a molding die having 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) silylpropyl methacrylate 40 parts by weight, 2
-Hydroxyethyl methacrylate 10 parts by weight, ethylene glycol dimethacrylate 3 parts by weight, 2,4,6-
0.2 parts by weight of trimethylbenzoyldiphenylphosphine oxide were 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 at a distance of 10 cm for 100 seconds using an 80 W / cm high pressure mercury lamp.

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

[0044]

The contact lens manufacturing method and the molding die used therefor according to the present invention are made of the same male and female molds, and one mold has a convex molding surface and a concave molding surface. Manufacturing a high quality contact lens with excellent optical performance without eccentricity because a polymerizable monomer is filled into the space that forms the lens shape 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 that is also 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 sectional view of a contact lens manufacturing mold used in Example 1 of the present invention.

FIG. 3 is an assembled cross-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 Side surface contact surface 6 Lens-shaped space 7 Air escape space

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masato Murayama Inventor Masato Murayama 3-3-5 Yamato, Suwa City, Nagano Seiko Epson 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, and 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 this mold is fitted. A method for producing a contact lens, which comprises: 2. A mold for use in a method for producing a contact lens, which is configured so that a lens-shaped space is formed when a male mold and a female mold are matched with 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, characterized in that one mold has a convex molding surface and a concave molding surface.