JPH06170857A - Production of contact lens and mold therefor - Google Patents

Abstract

PURPOSE:To obtain a low-cost contact lens having a smooth edge shape and surface and corresponding to a lens specification of a different shape by a method wherein a male mold is made of a resin having a low molding shrinkage, a female mold is made of a transparent resin, a monomer is charged between the molds, and after the monomer is photopolymerized, the female mold side of the molded piece is cut. CONSTITUTION:As a male mold having a BC surface, a resin having a low molding shrinkage in volume and realizing a sufficient profile irregularity is used: for example, polyamide, ethylene-polyvinyl alcohol copolymer, polyacetal, or amorphous polyolefin. An attachment 4 to be mounted on a lens cutting lathe is provided. As a female mold having an FC surface, a resin having a sufficient transparency is used: for example, polyolefin, polycarbonate, styrene, or acrylic resin. A polymerizable monomer is charged into a cavity 7. After the monomer is photopolymerized by being irradiated with a light from the female mold side, the molded piece fitted with the molds intact or removed from the female mold is mounted on the lens cutting lathe and cut on its FC side.

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 edge shape and 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 that can be used for various types of lens specifications having different shapes.

[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. Yes, but the cost is very high. Currently, most hard contact lenses are manufactured by this race cut method, and many manufacturers also manufacture soft contact lenses by the race 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. For this reason, various techniques for manufacturing low-cost, high-quality soft contact lenses have been carried out by the hands of researchers and engineers in the past. A feature of soft contact lenses is that the lenses themselves are flexible and fit along the corneal shape, so they do not require an extremely large number of BC types like hard contact lenses. Therefore, the molding method is considered to be suitable for manufacturing a contact lens at low cost and with little variation in 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. The technology of manufacturing contact lenses by the molding method is already known, but in order to improve the optical performance and wearing feeling of the obtained contact lens, and because post-processing after manufacturing the contact lens by the molding method is not required. A great number of techniques have been developed and are disclosed in patents and the like.

[0006] 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 JP-A-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 placing a male mold and a female mold in a rear pressure unit and applying pressure to the outer peripheral portion of the lens. A method for preventing the occurrence of burrs and eliminating the need for post-processing is disclosed.

Further, as a technique 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 each other, a contact lens is disclosed in 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., for example.

Furthermore, a molding method capable of manufacturing a contact lens with little variation in quality at low cost,
There is also proposed a method combining a race cut method, which is capable of flexibly producing a wide variety of contact lenses having different shapes. For example, JP-A-59-95118
Japanese Patent Publication No. 3-76213 discloses a method of machining the peripheral portion of a lens material together with both molds while the contact lens material is sandwiched between the male mold and the female mold. Is a method in which the convex surface of the lens material is machined together with the mold while the contact lens material is still sandwiched between the two molds. Japanese Patent Laid-Open No. 1-92719
It is disclosed in Japanese Patent Publication No.

[0009]

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.

As a method for producing a low-cost, high-quality contact lens which can be applied to these disposable contact lenses, Japanese Patent Publication No. 55-26446 and Japanese Patent Laid-Open No. 6-26246.
In the method of manufacturing a contact lens described in JP-A-2-297119 and JP-A-62-297120, a spacer is sandwiched between a male mold and a female mold, and a contact lens material is placed in a space formed when the spacers are fitted. It is a method of filling to obtain a contact lens. This is a device to eliminate the need for secondary processing because the edge shape is smooth, and to prevent burrs from occurring on the outer periphery of the lens, but this also increases the number of types of molds and leads to an increase in cost. The edge shape of the contact lens obtained by this method cannot be said to be clinically sufficiently satisfactory.

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 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 in order to prevent the occurrence of burrs. In addition, however, the shape of the edge portion of the contact lens obtained by this method cannot be said to be clinically sufficiently satisfactory. Further, in this molding die, the contact surface between the male die and the female die is very narrow, so that it is relatively difficult to obtain the accuracy of the thickness of the lens, and the above-mentioned eccentricity is likely to occur. Even with the methods described in JP-A-61-290012 and JP-A-2-172712, the shape of the edge portion cannot be said to be clinically sufficiently satisfactory, and it is extremely difficult to eliminate this eccentricity. It can be said to be difficult.

Up to this point, the respective techniques for forming a soft contact lens in one shot by the molding method have been mainly described, but the overall major problem of the molding method is that various types of contact lenses having different shapes are used. Cannot be manufactured flexibly and the quality of the edge shape is limited. As an effective means to solve this problem, we combined a molding method that can manufacture contact lenses with less variation in quality at low cost and a race cut method that can flexibly manufacture a wide variety of contact lenses with different shapes. A method has been proposed.

According to the method of manufacturing a contact lens described in Japanese Patent Laid-Open No. 59-95118, the peripheral portion of the lens material is put together with both molds while the contact lens material is kept sandwiched between the male mold and the female mold. However, in this method, BC and FC (front curve: the surface opposite to the surface where the contact lens comes into contact with the cornea, or the curvature of that surface) are determined by the shape of the mold. It is not possible to flexibly manufacture a wide variety of contact lenses. The contact lens manufacturing method described in Japanese Patent Publication No. 3-76213 is a method in which the convex surface of the lens material is machined together with the mold while the contact lens material is still sandwiched between the two molds. In particular, there is a drawback that the surface accuracy of BC is insufficient. This is often due to the types of materials used conventionally. Similarly, sufficient surface accuracy cannot be obtained even by the contact lens manufacturing method described in JP-A-63-3910.

The problems with the current contact lens manufacturing method and the advantages and problems of manufacturing a contact lens using the molding method or a combination of the molding method and the race cut method have been described above. However, according to the present invention, it is possible to manufacture a low-cost contact lens that has excellent optical properties, has a smooth edge shape and surface that does not damage the cornea, and is capable of meeting various types of lens specifications with different shapes. The purpose is.

[0017]

That is, according to the method of manufacturing a contact lens of the present invention, a male mold made of a resin having a small molding shrinkage is matched with a female mold made of a transparent resin, and the contact between the male mold and the female mold is made. After the polymerizable monomer is filled in the space formed in the mold and polymerized by irradiating it with light from the female mold side, the male mold is lensed with the two molds still matching or with the female mold removed. It is characterized by being mounted on a lathe for cutting and cutting the FC side of the lens.

The mold used to manufacture the contact lens of the present invention is a male mold made of a resin having a small mold shrinkage and a female moldable resin which is machinable and has sufficient transparency to transmit light rays. It is characterized by combining molds.

Furthermore, the male material is selected so as to have higher adhesion to the contact lens material than the female material, and the lens adheres to the male side when the female mold is removed from the male mold. It is characterized by that.

Furthermore, either the male mold or the female mold is subjected to a surface treatment, and the male mold surface is selected so that the adhesion to the contact lens material is greater than that of the female mold surface. It is characterized in that the lens is adhered to the male mold side when the female mold is removed from the mold.

The present invention will be described in detail below.

FIG. 1 is a sectional view of a male mold of a contact lens molding die according to the present invention, FIG. 2 is a sectional view of a female mold, and FIG. 3 is an assembled sectional view showing a coupled state of the contact lens molding die according to the present invention. is there.

As shown in FIG. 1, the male mold of the contact lens mold of the present invention comprises a convex BC optical surface 1 which forms BC when molded into a contact lens shape, and after filling with a polymerizable monomer. It is composed of a male contact surface 2 which is brought into contact when the molds are matched with each other, and an attachment 4 which is attached to a lathe for cutting a lens after superposition. Convex BC that forms BC when molded into a contact lens shape
The optical surface 1 is processed into a sufficiently smooth mirror surface.

On the other hand, the female mold is polymerized as shown in FIG.
The concave FC forming surface 5 that forms the FC of the contact lens after cutting, the contact surface 3 of the mold that contacts when the mold is matched after filling with the polymerizable monomer, and the displacement of the positions of the FC surface and the BC surface are prevented. It is composed of the side surface contact surface 6 of the mold.

When these male and female molds are assembled to match each other, a lens-shaped space (cavity) 7 is formed between the FC forming surface and the BC optical surface, as shown in FIG. After the polymerizable monomer is filled in the tee and polymerized, the male mold is attached to the lens cutting lathe via the attachment while the two molds are still matched or the female mold is removed, and the FC of the lens is attached. The side is cut to obtain a contact lens.

Next, the material of the molding die will be described. The mold of the present invention is characterized by using different materials for the male mold and the female mold. Polyolefins such as polyethylene and polypropylene are usually used as a disposable material for manufacturing contact lenses. This is because, in addition to the reason that the material is inexpensive, photopolymerization is mainly performed by irradiating light rays when manufacturing a contact lens by a molding method, but the mold used in this case is necessary for polymerization. This is because it must transmit a sufficient amount of light rays. However, as a feature of these materials, volume shrinkage during molding is large, and it is very difficult to obtain sufficient surface accuracy after molding. In addition, as a condition of a mold used for manufacturing a contact lens, the mold releasability between the mold and the contact lens material is a very serious problem. Therefore, the material of the mold that can be used as the contact lens molding mold is considerably limited, but it is necessary to select a material sufficient for obtaining the surface accuracy of the optical surface from among them. Therefore, the molding die of the present invention uses a resin that has a small volume shrinkage due to molding and can provide sufficient surface accuracy, regardless of whether light rays are transmitted to a male mold having a BC optical surface that is not subjected to secondary processing. It is characterized in that a resin which is machinable and has sufficient transparency to transmit a light ray necessary for polymerization is used for a female mold having an FC forming surface which is secondarily processed after molding. Therefore, the polymerization is completed by filling the space formed between the male mold and the female mold with a polymerizable monomer and irradiating it with light rays from the female mold side made of a transparent resin.

By producing a contact lens by the above method, it is possible to produce a high quality contact lens having excellent optical properties and having a smooth edge shape and a surface that does not damage the cornea. Also, F
Since the C surface is machined, it can be used for various types of lens specifications with different shapes and can be manufactured at low cost. Furthermore, it is possible to avoid eccentricity, which is a problem in manufacturing a contact lens by the molding method.

As a concrete material of the molding die used in the present invention, a material generally used as a molding material 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, by making this mold disposable, it is possible to omit the mold cleaning step and manufacture a contact lens with extremely high productivity.

Examples of thermoplastics that can be used as the male material include polyamide, ethylene-polyvinyl alcohol copolymer, polyacetal, and amorphous polyolefin.

On the other hand, examples of thermoplastics that can be used for the female material include polyolefins such as polyethylene and polypropylene, polycarbonate, polystyrene, acrylic resin and the like.

Among these plastics, the polymerization method of contact lenses, kinds of polymerizable monomers, cost, etc., and physical properties of plastics such as volume shrinkage at the time of molding, light transmittance, heat resistance and solvent resistance. In consideration of mechanical properties (viscoelasticity, etc.), moldability, etc., the mold material most suitable for the intended contact lens production is selected.

The method of manufacturing the contact lens of the present invention comprises:
The space between the male mold and the female mold is filled with a polymerizable monomer, and after this is photo-cured, the male mold is a lathe for lens cutting with the two molds still in agreement or with the female mold removed. It is characterized in that it is attached to and the FC side of the lens is cut. In this manufacturing method, when cutting with both molds still matching, it is not necessary to separate the female mold from the male mold, so it is very important to control the adhesion between the contact lens material and the mold. is not a problem. Rather, it may be better to firmly adhere the contact lens material and the female mold. However, when the female mold is removed from the male mold for cutting, the contact lens material must always be adhered to the male mold side when the female mold is removed from the male mold. Therefore, when selecting the material used for the mold, the adhesion with the contact lens should be taken into consideration.

However, it may not be possible to always control the state in which the contact lens material is adhered to the male mold side when the female mold is removed from the male mold only by selecting the material used for the mold. As a means in this case, there is a method in which either the male mold or the female mold is surface-treated so that the surface of the male mold has a higher adhesion to the contact lens material than the surface of the female mold. . The same can be said when the mold materials of the same material are used for the male mold and the female mold.

Plasma treatment can be used as the surface treatment method. The plasma treatment method can be either corona discharge or glow discharge, but generally the surface energy of the plasma-treated resin surface is higher than that of the untreated surface, and the adhesion with other resins is large. . Therefore, in the present invention, a method of adhering the contact lens material to the male mold side when removing the female mold from the male mold by improving the adhesion with the contact lens material by performing plasma treatment only on the male mold is suitable. There is.

On the other hand, as another method of surface treatment, fluororesin coating can be mentioned.
This method has an advantage that it can be carried out by a simple operation, only by applying a commercially available fluororesin coating agent. Also, when the mold is used as a disposable item, the durability of the coating agent is not a big problem,
There are many types of coating agents that can be used. Generally, the surface energy of a resin surface coated with a fluorine-based resin is lower than that of an untreated surface, and the adhesion with other resins is low. Therefore, in the present invention, a method of adhering the contact lens material to the male mold side when removing the female mold from the male mold by lowering the adhesiveness with the contact lens material by applying the fluororesin coating only to the female mold is provided. Are suitable.

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 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 female mold, and the convex molding surface of the male mold is superposed on the polymerizable monomer. At this time, be careful that the contact surface of the mold and the contact surface of the side surface are in complete contact.
It is suitable to irradiate ultraviolet rays or the like from the female mold side of the mold thus assembled to cause 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.

[0040]

The method for producing a contact lens according to the present invention and the molding die used for the method are characterized by using a male mold made of a resin having a small molding shrinkage and a female mold made of a transparent resin. The molds are matched, the polymerizable monomer is filled in the space formed between the male mold and the female mold, and the light is irradiated from the female mold side to polymerize it, and then the two molds remain matched. With or without the female mold, the male mold is attached to the lathe for lens cutting and the FC side of the lens is cut, so it has excellent optical properties and has a smooth edge shape and surface that does not damage the cornea. In addition, it is possible to manufacture a low-cost contact lens that can meet various types of lens specifications having different shapes.

[0041]

[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, polyamide was used as the material for the male mold shown in FIG. 1, the BC optical surface had a curvature of 7.25 mm, and the material for the female mold shown in FIG. 2 was used. A molding die manufactured by injection molding was used in which the curvature of the FC formation surface was 7.2 mm using polypropylene. 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 0.05 parts by weight of 2,4,6-trimethylbenzoyldiphenylphosphine oxide were mixed well. Then
This mixture was used after deaeration and nitrogen replacement.
This mixture was filled in the former mold, and 80 W / cm
Ultraviolet rays were irradiated from the female mold side at a distance of 10 cm for 100 seconds using a high pressure mercury lamp. After curing, the female mold was removed from the male mold, the male mold to which the semi-finished lens was adhered was mounted on a lathe for lens cutting, the FC side of the lens was cut with a curvature of 7.70 mm, and then the FC side surface was polished. 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 edge portion and the surface of the soft contact lens thus obtained were smooth, and there were no voids on the surface or inside of the contact lens. The BC of this soft contact lens is 8.60 mm and the power is -3.00.
The optical performance was very excellent, such as D. and no prism was observed.

(Embodiment 2) In this embodiment, polyamide is used as the material of the male die shown in FIG. 1, the BC optical surface has a curvature of 6.90 mm, and the material of the female die shown in FIG. 2 is used. A molding die manufactured by injection molding was used in which the curvature of the FC formation surface was 7.2 mm using polypropylene. 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 0.05 parts by weight of 2,4,6-trimethylbenzoyldiphenylphosphine oxide were mixed well. Then
This mixture was used after deaeration and nitrogen replacement.
This mixture was filled in the former mold, and 80 W / cm
Ultraviolet rays were irradiated from the female mold side at a distance of 10 cm for 100 seconds using a high pressure mercury lamp. After curing, the female mold was removed from the male mold, the male mold to which the lens semi-finished product was adhered was mounted on a lens cutting lathe, the FC side of the lens was cut with a curvature of 7.65 mm, and then the FC side surface was polished. 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 smooth edges and surface, and there were no voids on the surface or inside of the contact lens. The BC of this soft contact lens is 8.20 mm and the power is -8.00.
The optical performance was very excellent, such as D. and no prism was observed.

Example 3 In this example, ethylene-polyvinyl alcohol copolymer was used as the material for the male mold shown in FIG. 1, the BC optical surface had a curvature of 6.90 mm, and FIG. Polymethylmethacrylate was used as the material of the female die shown, and a molding die manufactured by injection molding was used with the FC forming surface having a curvature of 7.2 mm. 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,
The mixture was thoroughly mixed with 0.05 parts by weight of 2,4,6-trimethylbenzoyldiphenylphosphine oxide, and the mixture was deaerated and replaced with nitrogen. This mixture was filled in the former mold, and this was irradiated with ultraviolet rays from the female mold side for 100 seconds at a distance of 10 cm using an 80 W / cm high pressure mercury lamp. After curing, the male mold was attached to a lathe for lens cutting in a state where the two molds were matched with each other, and the FC side of the lens was cut together with the female mold at a curvature of 7.65 mm, and then the FC side surface was polished. 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 smooth edges and surface, and there were no voids on the surface or inside of the contact lens. The BC of this soft contact lens is 8.20 mm and the power is -8.00.
The optical performance was very excellent, such as D. and no prism was observed.

Example 4 In this example, polyacetal was used as the material of the male mold shown in FIG. 1, the curvature of the BC optical surface was 7.21 mm, and the material of the female mold shown in FIG. 2 was used. A molding die manufactured by injection molding was used in which the curvature of the FC formation surface was 7.2 mm using polycarbonate. 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 was irradiated with ultraviolet rays from the female mold side for 100 seconds at a distance of 10 cm using an 80 W / cm high pressure mercury lamp. After curing, the male mold was attached to the lens cutting lathe in a state where the two molds were matched with each other, the FC side of the lens was cut together with the female mold at a curvature of 7.72 mm, and then the FC side surface was polished. 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 smooth edges and surface, and there were no voids on the surface or inside the contact lens. The BC of this soft contact lens is 8.60 mm and the power is -3.00.
The optical performance was very excellent, such as D. and no prism was observed.

(Embodiment 5) In this embodiment, as materials for the male mold shown in FIG. 1 and the female mold shown in FIG. 2, amorphous polyolefin (ZEONEX 280: Nippon Zeon Co., Ltd.) is used.
A molding die manufactured by injection molding was used with the male BC optical surface having a curvature of 7.21 mm and the female FC forming surface having a curvature of 7.2 mm. The male mold used here was subjected to plasma treatment. As a plasma treatment method, the male mold is set in a plasma device, and the discharge frequency is 1 in an argon atmosphere with a vacuum degree of 0.1 Torr.
Treatment was performed at 3.56 MHz and discharge power of 200 W for 3 minutes. 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 into the former mold, and
10 at a distance of 10 cm using a 0 W / cm high pressure mercury lamp
Ultraviolet rays were irradiated from both the male side and the female side for 0 seconds. After curing, the female mold was removed from the male mold, and the male mold to which the semi-finished lens was adhered was mounted on a lathe for lens cutting, the FC side of the lens was cut with a curvature of 7.72 mm, and then the FC side surface was polished. 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 smooth edges and surface, and there were no voids on the surface or inside of the contact lens. The BC of this soft contact lens is 8.60 mm and the power is -3.00.
The optical performance was very excellent, such as D. and no prism was observed.

(Embodiment 6) In this embodiment, as materials for the male mold shown in FIG. 1 and the female mold shown in FIG. 2, amorphous polyolefin (ZEONEX 280: Nippon Zeon Co., Ltd.) is used.
A molding die manufactured by injection molding was used with the male BC optical surface having a curvature of 7.21 mm and the female FC forming surface having a curvature of 7.2 mm. The female mold used here was coated with a fluororesin coating agent. 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
100 at a distance of 10 cm using a W / cm high pressure mercury lamp
Ultraviolet rays were irradiated from both the male side and the female side for a second.
After curing, remove the female mold from the male mold and attach the male mold to which the semi-finished lens product is bonded to the lens cutting lathe.
After cutting the C side with a curvature of 7.72 mm, the FC side surface was polished. 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 edge portion and the surface of the soft contact lens thus obtained were smooth, and there were no voids on the surface or inside of the contact lens. The BC of this soft contact lens is 8.60 mm and the power is -3.00.
The optical performance was very excellent, such as D. and no prism was observed.

Example 7 In this example, an amorphous polyolefin (ZEON) was used as the male material shown in FIG.
EX280: manufactured by Nippon Zeon Co., Ltd., the BC optical surface has a curvature of 7.21 mm, and the female mold material shown in FIG. 2 is polypolypropylene. The FC forming surface has a curvature of 7.2 mm. The mold used was injection molding. The male mold used here was subjected to corona discharge treatment. The corona discharge treatment is carried out by using the male mold with an interelectrode distance of 2 cm, an interelectrode voltage of 25 kV, and a frequency of 2
It was placed between electrodes of a 0 KHz corona discharge device and treated for 1 minute. 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 a distance of 10 cm was obtained by using an 80 W / cm high pressure mercury lamp.
UV irradiation was performed from both the male side and the female side for 100 seconds. After curing, the female mold was removed from the male mold, and the male mold to which the semi-finished lens was adhered was mounted on a lathe for lens cutting, the FC side of the lens was cut with a curvature of 7.72 mm, and then the FC side surface was polished. 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 edge portion and the surface of the soft contact lens thus obtained were smooth, and there were no voids on the surface or inside of the contact lens. The BC of this soft contact lens is 8.60 mm and the power is -3.00.
The optical performance was very excellent, such as D. and no prism was observed.

(Embodiment 8) In this embodiment, polyamide is used as the male material shown in FIG. 1, the BC optical surface has a curvature of 7.80 mm, and the female material shown in FIG. 2 is used. Using polypropylene, the curvature of the FC formation surface is 7.
A mold produced by injection molding with a size of 5 mm was used. As the polymerizable monomer, 44 parts by weight of 2,2,2-trifluoroethyl methacrylate, 40 parts by weight of tris (trimethylsiloxy) silylpropyl methacrylate, 10 parts by weight of 2-hydroxyethyl methacrylate,
3 parts by weight of ethylene glycol dimethacrylate, 2,
0.26 parts by weight of 4,6-trimethylbenzoyldiphenylphosphine oxide were mixed well, and the mixture was deaerated and replaced with nitrogen. This mixture was filled in the former mold, and this was irradiated with ultraviolet rays from the female mold side for 100 seconds at a distance of 10 cm using an 80 W / cm high pressure mercury lamp. After curing, remove the female mold from the male mold, attach the male mold to which the semi-finished lens is adhered to the lathe for lens cutting, cut the FC side of the lens with a curvature of 8.10 mm, and then
The side surface was polished.

The contact lens thus obtained had smooth edges and surface, and there were no voids on the contact lens surface and inside. The BC of this soft contact lens was 7.80 mm, the power was -2.00 D, and the prism was not observed at all, and the optical performance was very excellent.

[0058]

The contact lens manufacturing method and the molding die used therefor according to the present invention are such that a male mold made of a resin having a small molding shrinkage and a female mold made of a transparent resin are matched with each other, and the contact between the male mold and the female mold. After the polymerizable monomer is filled in the space formed in the mold and polymerized by irradiating it with light from the female mold side, the male mold is lensed with the two molds still matching or with the female mold removed. Since it is attached to a cutting lathe and the FC side of the lens is cut, it has excellent optical properties, has a smooth edge shape and surface that does not damage the cornea, and has a variety of lens specifications with different shapes A compatible low-cost contact lens can be manufactured.

[Brief description of drawings]

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

FIG. 2 is a sectional view of a female mold for manufacturing a contact lens 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 BC optical surface 2 Male contact surface 3 Female contact surface 4 Attachment when mounting on lathe 5 FC forming surface 6 Side contact surface of type 7 Space forming lens shape

Claims (10)

[Claims] 1. A male mold made of a resin having a small molding shrinkage and a female mold made of a transparent resin are matched with each other, and a space formed between the male mold and the female mold is filled with a polymerizable monomer. After polymerizing by irradiating light from the mold side, attach the male mold to the lens cutting lathe with both molds matched or with the female mold removed, and cut the front curve side of the lens A method of manufacturing a contact lens, comprising: 2. The method for producing a contact lens according to claim 1, wherein the material used for the male mold is a resin selected from polyamide, ethylene-polyvinyl alcohol copolymer, polyacetal, and amorphous polyolefin. . 3. The material used for the female mold is polyethylene,
The method for producing a contact lens according to claim 1, which is made of a resin selected from polyolefins such as polypropylene, polycarbonate, polystyrene, and acrylic resin. 4. A contact lens manufacturing method comprising a combination of a male mold made of a resin having a small molding shrinkage and a female mold made of a resin which is machinable and has sufficient transparency to transmit light rays. Mold used. 5. The male material is selected so that the contact lens material has a higher adhesion than the female material, and the lens adheres to the male side when the female mold is removed from the male mold. A mold used for manufacturing the contact lens according to claim 4, wherein the mold is a mold. 6. The contact according to claim 4, wherein the material used for the male mold is a resin selected from polyamide, ethylene-polyvinyl alcohol copolymer, polyacetal and amorphous polyolefin. Mold used to manufacture lenses. 7. The material used for the female mold is polyethylene,
A molding die used for producing a contact lens according to claim 4 or 5, which is made of a resin selected from polyolefins such as polypropylene, polycarbonate, polystyrene, and acrylic resin. 8. A surface treatment is applied to either the male mold or the female mold, and the male mold surface is selected so that the adhesion to the contact lens material is greater than that of the female mold surface. The mold used for manufacturing a contact lens according to claim 4, wherein the lens is adhered to the male mold when the female mold is removed. 9. A mold for use in manufacturing a contact lens according to claim 8, which is subjected to a surface treatment by plasma treatment. 10. A mold for use in manufacturing a contact lens according to claim 8, which is surface-treated with a fluororesin coating.