JPS62278024A - Processing of soft spectacle lens material - Google Patents

Abstract

PURPOSE:To machine a soft material easily and accurately without necessitaing a great deal of equipment and cost by a method wherein hard polymer is removed from a molded form obtained by machining a polymer blended material constituted of a soft material and the hard polymer into a desired configuration. CONSTITUTION:A hard polymer is removed from a molded form obtained by machining a polymer blended material, constituted of a soft material and the hard polymer, into a disired configuration. Usually, the machining of a soft spectacle lens material is hard in a normal temperature, however, the hard polymer is added into the soft material, therefore, said lense material can be applied with machining into the desired configuration in the ordinary temperature without cooling it. Further, when the hard polymer, contained in the material of the molded form, is removed after machining it, the molded form, constituted of the soft spectacle lens material, may be obtained.

Description

Detailed Description of the Invention 3 Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for processing soft ophthalmic lens materials. More specifically, the present invention is applicable to the field of ophthalmological medical products and other products that require precision machining, and in particular to machining materials that are essentially or partially composed of soft materials in accordance with strict standards. The present invention relates to a method for processing soft ophthalmic lens materials that can be suitably used in the field of ophthalmic lenses such as contact lenses and intraocular lenses.

[Prior Art] Among various materials that exist as ophthalmic lens materials, hydrous soft ophthalmic lens materials mainly made of poly-2-hydroxyethyl methacrylate or poly-N-vinylpyrrolidone absorb water and swell. Because it has the property of softening,
It has been in the spotlight in recent years because it is comfortable to wear and easily adapts to the cornea.

However, when a material that softens with water is used, for example, as a soft contact lens, it has the following drawbacks.

(b) Because it is water-containing, excrement from lachrymal fluid tends to accumulate inside the material, often causing serious damage to the eyes.

(b) Bacteria and other substances tend to grow on the lenses, which is troublesome and requires careful use and storage, including periodic boiling sterilization.

Therefore, in this field, in order to eliminate the disadvantages of soft contact lenses and not impair the feeling of wearing them, soft eye lens materials that do not contain water or have only a slight water content, including soft contact lenses, are being developed. Application to ophthalmic lens materials has been proposed. In general, materials that soften when exposed to water have a relatively high glass transition temperature in an unabsorbed state, and are sufficiently rigid to be cut into a desired shape, so they can be cut into a desired shape in an unabsorbed state, and then softened with water for contact lenses. Methods of obtaining ophthalmic lenses such as On the other hand, soft ophthalmic lens materials that do not contain water or only slightly contain water have a low glass transition temperature and are flexible at room temperature, so it has been difficult or impossible to cut them.

As methods for manufacturing ophthalmic lenses such as contact lenses using such soft ophthalmic lens materials, the following two methods have been proposed.

(1) Processing method in which soft ophthalmic lens material is cooled and hardened, and then cut (Japanese Patent Publication No. 56-1.3583
(Japanese Patent Publication No. 57-53569).

(2) After polymerization, a method in which a monomer that provides a soft material is injected into a mold and polymerized to produce a molded product; an oligomer such as a urethane precursor, a silicone precursor, or a liquid rubber is injected into the mold. Mold forming methods, such as methods for producing molded products by curing and curing.

The cutting method (1) above requires large-scale equipment to cool the soft material, which increases the cost and is not economical.Also, cooling the soft material itself makes it brittle, making cutting difficult. There is a problem that this may happen.

In addition, as the molding method (2), when a molded article is produced by injecting a monomer into a mold and polymerizing it to produce a molded article, shrinkage occurs during polymerization, causing distortion and polymerization. It is difficult to obtain a molded product with the desired shape because it is prone to unevenness, mass production requires many molds of various specifications, and it uses volatile monomers. There is a problem in that a part of the monomer evaporates during polymerization, making it impossible to obtain a molded article with a desired shape.

When producing a molded article by injecting an oligomer into a mold and curing it, volumetric shrinkage occurs during curing, making it difficult to obtain a molded article with the desired shape. It is difficult to use, and the resulting molded product may have unevenness or cracks, so it is not suitable for applications in fields that require precision processing, such as contact lenses, or even for mass production. This method requires a large number of molds of various specifications, which poses problems such as being uneconomical.

Furthermore, when producing molded products by extrusion molding or calendering raw rubber and then vulcanization molding, mass production requires a large number of molds of various specifications, and It is difficult to perform precision processing such as cutting on molded products.

[Problems to be Solved by the Invention] Therefore, the present inventor has made efforts to solve the problems of the conventional technology as described above and to easily manufacture a molded product having a desired shape from a soft ophthalmic lens material. As a result of repeated research, we have discovered a method for processing soft ophthalmic lens materials that can solve these problems, and have completed the present invention.

[Means for Solving the Problems] That is, the present invention is characterized in that the hard polymer is removed from a molded article obtained by cutting a polymer blend consisting of a soft material and a hard polymer into a desired shape. The present invention relates to a method for processing soft ophthalmic lens materials.

[Function] Normally, soft ophthalmic lens materials are difficult to cut at room temperature, but according to the method for processing soft ophthalmic lens materials of the present invention, a hard polymer can be used in addition to conventional soft materials. The molded product material can be easily cut into a desired shape at room temperature without cooling, and if the hard polymer contained in the molded product material is removed after cutting, it can be easily cut into a desired shape at room temperature without cooling. Molded products made of soft ophthalmic lens materials having properties comparable to those of soft ophthalmic lens materials can be obtained.

[Example] The soft material used in the present invention has a crosslinked structure due to chemical bonds or ionic bonds, and has the property that these bonds will not be broken by the solvent, monomer, etc. used in the present invention. However, the soft materials used here are those in which it is difficult or impossible to use mechanical processing methods such as cutting under normal environments and atmospheres without swelling with water or other solvents. say something When the glass transition temperature of a soft material exceeds 40°C, it becomes rigid under normal environments and atmospheres without being swollen with water or other solvents, making it possible to use mechanical processing methods such as cutting. Therefore, a temperature of 40'C or less, particularly 30C or less, can be preferably applied to the present invention.

Specific examples of monomers providing the soft material include methyl acrylate, ethyl acrylate, isopropyl acrylate, n-propyl (meth)acrylate, imbutyl acrylate, n-butyl (meth)acrylate, 2-ethylhexyl acrylate, n- Octyl (meth)acrylate, n-decyl methacrylate, n-dodecyl (meth)acrylate, n-tetradecyl (meth)acrylate, lauryl (meth)acrylate, cyclohexyl acrylate, 2-ethoxyethyl acrylate, 3-ethoxypropyl acrylate, Alkyl and alkoxyalkyl (meth)acrylates such as 2-methoxyethyl acrylate and 3-methoxypropyl acrylate, organosiloxysilylalkyl (meth)
(meth)acrylic esters such as acrylates and fluoroalkyl (meth)acrylates; alkylstyrenes such as 4-dodecylstyrene, 4-hexylstyrene, 4-nonylstyrene, and 4-octylstyrene; organosiloxysilyl (alkyl ) Styrenes such as styrenes and fluoroalkylstyrenes; vinyl acetate,
Examples include vinyl esters such as cyclopentyl acetate; dienes such as chloroprene, isoprene, and butadiene; and monomers that provide soft materials such as vinyl ethers such as ethyl vinyl ether and butyl vinyl ether, but these monomers may be used alone. , or two or more types may be used in combination.

The monomers providing these soft materials may be copolymerized with other monomers.

Examples of the other monomers include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, hydroxybutyl (meth)acrylate, and hydroxypropyl (meth)acrylate when imparting hydrophilicity; (Alkyl)aminoalkyl (meth)acrylates such as 2-dimethylaminoethyl (meth)acrylate, 2-butylaminoethyl (meth)acrylate, (meth)acrylamide, glycerol (meth)acrylate, propylene glycol mono(meth)acrylate, Polyglycol mono(meth)acrylate, vinylpyrrolidone, (meth)acrylic acid, maleic anhydride, maleic acid, aminostyrene,
In cases where hydroxystyrene etc. also impart oxygen permeability, organosiloxysilylalkyl (meth)acrylates such as tris(trimethylsiloxy)silyl(meth)acrylate, hexafluoroisopropyl(meth)acrylate, trifluoroethyl( Examples include fluoroalkyl (meth)acrylates such as meth)acrylate.

Further, in cases where other functions are imparted in addition to these, examples include glycidyl (meth)acrylate, glycidyl ether, vinyl chloroacetate, and 2-chloroethyl vinyl ether.

The other monomer is monomer 10 that provides the soft material.
0.1 to 100 mole parts relative to 0 mole part, <1
It is used by adding 0 to 50 mole parts.

In addition, when adjusting the hardness of soft materials, for example, methyl methacrylate, t-butyl methacrylate, styrene,
0.1 to 100 mole parts of t-butylstyrene, α-methylstyrene, (meth)acrylonitrile, vinyltoluenes, etc. per 100 mole parts of the monomer providing the soft material.
It is added in an amount of <10 to 100 molar parts.

These other monomers may be used alone or in combination of two or more of the monomers that provide the soft material, if necessary.

Note that a crosslinking agent is added to the monomers that provide these soft materials, or a mixture of these and other monomers, if necessary, for crosslinking.

The crosslinking agents include ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1.4-butylene glycol dimethacrylate, 1.3-butylene glycol dimethacrylate, and aryl. Diglycol carbonate, triaryl cyanurate, diaryl phthalate, N.

Examples include N'-methylenebisacrylamide, N,N'-methylenebismethacrylamide, and divinylbenzene.

The crosslinking agent is usually added in an amount of 0.1 to 10 mol parts, preferably <0.5 to 4 mol parts, per 100 mol parts of the monomers that provide the soft material or a mixture of these and other monomers. .

In addition to the monomers that provide the above-mentioned soft materials or soft materials made of these and other monomers, soft materials include polyethylene, polyisobutylene, natural rubber, emulsion polymerization styrene-butadiene rubber, solution polymerization styrene-butadiene rubber, fluororubber, etc. It is possible to use a polymer crosslinked with a suitable crosslinking agent or a suitable crosslinking method as the material in the present invention.

Examples of suitable crosslinking methods include crosslinking using sulfur, organic peroxides, radiation, and the like.

For example, a copolymer composed of n-butyl acrylate and 2-chloroethyl vinyl ether can be crosslinked with sulfur, and such a crosslinked product can also be used in the present invention.

Furthermore, in addition to the above, silicone rubber or polyurethane obtained by an addition reaction between vinyl-terminated polydimethylsiloxane and polymethylhydrosiloxane may also be used.

The hard polymer used in the present invention is a linear polymer that does not contain or form a crosslinked structure,
Its glass transition temperature is at least 60°C, preferably 90°C.
Examples of such hard polymers include: Polymethyl methacrylate, poly t-butyl methacrylate, polystyrene, poly α-methylstyrene, poly t-butylstyrene, polyvinyl chloride, poly 4-methylpentene-1, polymethacrylic acid and its salts, polyacrylamide, poly(meth) Vinyl polymers such as acrylonitrile, poly2-chlorostyrene, 3-chlorostyrene, polyester, polyamide, polycarbonate, polyphenylene oxide,
Examples include condensation polymers such as polyacetal and polycellulose acetate, and these polymers may be used alone or in combination of two or more.

A polymer blend can be obtained by mixing the soft material and the hard polymer, for example, by impregnating and polymerizing a monomer that provides the hard polymer into the soft material.

The soft material and the hard polymer need only be mixed to such an extent that the resulting polymer blend can be cut at room temperature and under normal environmental conditions, and therefore can be mixed to such an extent that a polymer blend having the desired hardness can be obtained. It is sufficient that the soft material and the hard polymer are dispersed in the material, but it is preferable that the soft material and the hard polymer be uniformly dispersed.

The proportion of the soft material and the hard polymer in the polymer blend cannot be determined unconditionally because it varies depending on the hardness of the intended lens material, but the proportion of the soft material is 20 to 60%, and the proportion of the hard polymer is 1% (the same applies hereinafter). Polymer is 8
It is preferably added in an amount of 0 to 40%.

The polymer blends are obtained by impregnating a soft material with monomers that give a hard polymer and then polymerizing the monomers.

First, a method for producing a polymer blend will be explained.

When the polymer blend is produced by impregnating a soft material with a monomer that provides a hard polymer and then polymerizing the monomer, the soft material must be three-dimensionally insolubilized with a crosslinking agent or the like, Also, this crosslinking is done by chemical bonds or ionic bonds,
These bonds must not be broken during the series of steps.

The monomer that provides the hard polymer should be one that has the ability to swell the soft material, but after polymerization forms a linear polymer that does not, in principle, have a crosslinked structure. Examples include methyl methacrylate, t-butyl methacrylate, styrene, t-butyl styrene, (meth)acrylonitrile, and the like.

In addition, when using an acrylic soft material made of polyalkyl acrylate as the soft material, for example, methyl methacrylate, t-butyl methacrylate, etc. are preferably used as monomers that provide the hard polymer, but in the present invention, only these are used. Without limitation, others can also be used.

Examples of methods for impregnating a soft material with a monomer that gives a hard polymer and then polymerizing the monomer include radical polymerization, ionic polymerization, photopolymerization, ultraviolet polymerization,
Examples include radiation polymerization and polyaddition methods, but especially when radical polymerization is applied, polymerization is possible at room temperature and pressure, and polymerizable species are not affected by impurities in the polymerization system. It is preferable because it is difficult to use, requires little effort for purification, and has good reproducibility.

However, when monomers are polymerized by radical polymerization, if a side reaction such as chain transfer of polymerization initiator radicals or propagating radicals to a soft material occurs, the reaction between the hard polymer and the soft material may occur. Chemical bonds are formed, and when the hard polymer is extracted later using a solvent, the hard polymer cannot be completely extracted and remains in the glass, resulting in an ophthalmic lens having the desired shape or elasticity. Sometimes I can't get it.

In order to suppress the occurrence of such side reactions, polymerization reaction initiators, monomers, and soft materials may be appropriately selected and used to prevent side reactions from occurring. In order to prevent migration, it is desirable to mix a chain transfer agent or a compound that is likely to undergo chain transfer into the monomers during polymerization.

Examples of the chain transfer agent or a compound that is susceptible to chain transfer include mercaptans such as n-butyl mercaptan, dodecyl mercaptan, and thioglycolic acid, disulfides such as tetraalkylthiuram disulfide and xanthate disulfide, diazothioether,
Examples include propatool, chloroform, bromoform, carbon tetrachloride, carbon tetrabromide, acetaldehyde, butyraldehyde, etc. These compounds are preferably mixed by being dissolved or emulsified in the monomer that provides the hard polymer. In the present invention, the chain transfer agent is preferably used in an amount not exceeding 10 parts by mole per 100 parts by mole of the monomer that provides the hard polymer. The polymerization initiator used when polymerizing the monomer to provide the hard polymer includes azobisisobutyronitrile, 2
．． 2'-azobis(2,4-dimethylvaleronitrile)
, azo initiators such as 2,2'-azobis(4-methoxy2,4-dimethylvaleronitrile), organic peroxides such as benzoyl peroxide and di-t-butyl peroxide, potassium persulfate, and ammonium persulfate. etc., and usually 0.01 to 0 per 100 mole parts of the monomer.
．． 5 molar parts are used.

In addition, during polymerization, an appropriate amount of inert solvents may be mixed in order to adjust the degree of swelling of the soft material (such inert solvents include benzene, toluene, dimethyl sulfoxide, etc.). , these inert solvents are
3 for 100 parts by weight of monomer giving a hard polymer
It is preferable to use it in a range not exceeding 0 parts by weight.

Note that it is preferable to select and use soft materials and hard polymers that exhibit compatibility, but if they are used in combination with materials that do not exhibit good compatibility, a compatibilizer may be added to improve the compatibility. Preferably, the hard polymer is dissolved or emulsified in a monomer containing the hard polymer.

Examples of compatibilizers that can be used in the present invention include those having one component that is a soft material or a polymeric component that has good compatibility with it, and one component that has a hard polymer or a polymeric component that has good compatibility with it. Examples include block or graft polymers. These compatibilizers are usually used in an amount of 1 to 1 per 100 parts by weight of the polymer blend.
It is used by adding 0 parts by weight. For example, in the case of hardening silicone soft materials with styrene, the compatibility is poor and the preferred polymer blend cannot be used, but as a compatibilizer, e.g. poly(styrene-b-
It is preferable to mix a block copolymer of dimethylsiloxane) or a graft copolymer of poly(styrene-g-dimethylsiloxane).

After polymerization and curing as described in section 1-1, the resulting polymer blend is cut in a normal environment and atmosphere, and if necessary, polished] to change the molded product of the polymer blend. .

A molded product of a polymer blend contains a hard polymer in a soft material, and is cured in a swollen state, so it may shrink slightly when the hard polymer is removed, which will be described in detail later. Therefore, it is preferable to determine the degree of swelling of the molded article in advance and cut the molded article into a desired size and shape according to the degree of swelling.

Next, the cut molded article is immersed in a suitable solvent to remove the hard polymer contained in the soft material.

The suitable solvent is one that has the ability to dissolve hard polymers and swell soft materials. Specific examples of such solvents include chloroform, methylene chloride,
Examples include ethylene chloride, carbon tetrachloride, benzene, toluene, xylene, tetrahydrofuran, dioxane, methyl ethyl ketone, ethyl acetate, methyl acetate, etc.
In the present invention, not only the solvents exemplified above but also other solvents can be used.

Next, after sufficiently removing the hard polymer from the molded product,
By drying the molded product, an ophthalmic lens having a desired shape is formed.

Next, the method for processing a soft ophthalmic lens material of the present invention will be explained based on Examples, but the present invention is not limited to these Examples.

Example 1 98.1 parts (by weight, the same applies hereinafter) of n-butyl acrylate, 1.8 parts of ethylene glycol dimethacrylate, 2
,2°-azobis(2,4-dimethylvaleronitrile)
After degassing the mixture consisting of 0.1 part, it is poured into a cylindrical glass container with an inner diameter of I2, nitrogen gas is introduced into the glass container, and a stopper is then provided at the opening of the glass container, A soft material was obtained by polymerizing at 30°C for 48 hours, then gradually increasing the temperature to 50°C for 5 hours, 80°C for 3 hours, and 100°C for 2 hours. The resulting soft material is highly elastic at room temperature,
It was transparent.

Next, we cut out the resulting cylindrical soft material into short pieces.
A cylinder with an inner diameter of approximately 113+++ m was injected with a uniformly mixed solution of 0 parts, 97.6 parts of methyl methacrylate, 2 parts of dodecyl mercaptan, and 0.4 parts of 2.2°-azobis(2,4-dimethylvaleronitrile). After placing the soft material in a shaped glass container and immersing it in the solution, filling the container with nitrogen gas and sealing the container, the soft material was allowed to reach an equilibrium swelling state at a temperature slightly lower than 30°C. The polymer blend was obtained by polymerization at ℃ for 3 days. The resulting polymer blend was slightly cloudy.

Next, the obtained polymer blend was cut into the shape of a contact lens at room temperature under a normal environmental atmosphere and polished. Since the polymer blend was hard, cutting and polishing were easy.

The resulting molded product was immersed in chloroform for 5 hours to swell, the hard polymer component polymethyl methacrylate was removed, and when dried, the surface was thoroughly polished.
The molded product was transformed into a transparent contact lens shape with the same elasticity as the soft material that was the raw material.

Comparative Example 1 A soft material was prepared in the same manner as in Example 1, and an attempt was made to perform cutting, but such cutting could not be performed.

Example 2 78.6 parts of n-butyl acrylate, 19.8 parts of n-butyl methacrylate, 1.7 parts of ethylene glycol dimethacrylate, and 2,2°-azobis(2,4-
After deaerating a mixture consisting of 0.1 part of dimethylvaleronitrile, it was poured into a cylindrical glass container with an inner diameter of 12III11, nitrogen gas was introduced into the glass container, and a stopper was then placed in the opening of the glass container. After heating at 30°C for 48 hours, the temperature was gradually increased to 50°C for 5 hours, and at 80°C for 3 hours.
Polymerization was carried out at 00°C for 2 hours to obtain a soft material. The obtained soft material was highly elastic and transparent at room temperature.

Next, the obtained soft material was immersed in the same solution as used in Example 1 to obtain a polymer blend in the same manner as in Example 1.

The resulting polymer blend was slightly cloudy.

Next, the obtained polymer blend was cut into the shape of a contact lens at room temperature and under a normal environmental atmosphere and polished. Since the polymer blend was hard, it was easy to cut or polish.

The resulting molded product was immersed in chloroform for 5 hours to swell, the hard polymer component polymethyl methacrylate was removed, and when dried, the surface was thoroughly polished.
The molded product was made from the soft material that was the raw material and had the same elasticity as the transparent contact lens shape.

Comparative Examples 2-24 A soft material was prepared in the same manner as in Example 2, and an attempt was made to perform cutting, but such cutting could not be performed.

Example 3 98.1 parts of ethyl acrylate, 1.8 parts of ethylene glycol dimethacrylate, 2,2°-azobis(2,4
- dimethylvaleronitrile) was degassed and poured into a cylindrical glass container with an inner diameter of 12 m11, nitrogen gas was introduced into the glass container, and then the mixture was poured into the opening of the glass container. Set up a stopper and incubate at 30°C for 48 hours.
Then, the temperature was gradually increased to 50°C for 5 hours, and 80°C for 3 hours.
Polymerization was carried out at 100°C for 2 hours to obtain a soft material. The obtained soft material was highly elastic and transparent at room temperature.

Next, 10 parts of the obtained soft material were mixed with 97.6 parts of methyl methacrylate, 2.1 parts of dodecyl mercaptan, 2.
2°-Azobis(2,4-dimethylvaleronitrile)0
．． A cylindrical glass container with an inner diameter of approximately 16 mm was injected with a solution containing three parts of the mixture, and the container was immersed in the solution.The container was filled with nitrogen gas, the stopper was closed, and the mixture was heated at a temperature slightly lower than 30°C. After allowing the soft material to reach an equilibrium swelling state, 30
The polymer blend was obtained by polymerization for 3 days at °C.

The resulting polymer blend was transparent.

Next, the obtained polymer blend was cut into the shape of a contact lens at room temperature under a normal environmental atmosphere and polished. Since the polymer blend was hard, cutting and polishing were easy.

The obtained molded product was immersed in chloroform for 5 hours and expanded to 7
11, the hard polymer component polymethyl methacrylate was removed, and when dried, the surface was sufficiently polished and the molded product had a transparent contact lens shape with the same elasticity as the soft material that was the raw material. .

Comparative Example 3 A soft material was prepared in the same manner as in Example 3, and an attempt was made to perform cutting, but such cutting could not be performed.

Examples 4 to 9 A mixture of raw materials for a soft material having the composition shown in Table 1 was polymerized in the same manner as in Example 1 to obtain a soft material. The resulting soft material was highly elastic, soft, and transparent at room temperature.

Next, 10 parts of the obtained soft material were mixed with 97.6 parts of methyl methacrylate, 2 parts of dodecyl mercaptan and 2.2 parts of the soft material.
°-Azobis(2,4-dimethylvaleronitrile) 0.
A uniformly mixed solution of 4 parts was placed in a container, immersed in the solution, and then polymerized in the same manner as in Example 1 to obtain a polymer blend. The resulting polymer blend was slightly cloudy.

Next, the obtained polymer blend was cut into the shape of a contact lens at room temperature under a normal environmental atmosphere and polished. Since the polymer blend was hard, cutting and polishing were easy.

The obtained molded product was immersed in chloroform in the same manner as in Example 1, and then dried, the surface was sufficiently polished and it had the shape of a transparent contact lens with the same elasticity as the soft material that was the raw material. The molded product was changed.

[Margin below] □ Example 10 Transparent, soft and elastic at room temperature, diameter l2Lllff
l cylindrical urethane rubber ADAPT-13OL (
(manufactured by Kokusai Chemical ■) 10 parts methyl methacrylate 97
．． 6 parts of dodecylmercaptan, and 0.4 parts of 2.2"-azobis(2,4-dimethylvaleronitrile) were treated in the same manner as in Example 1 to obtain a polymer blend. The resulting polymer blend was transparent.

Next, the obtained polymer blend was cut into the shape of a contact lens and polished. Since the polymer blend was hard, cutting and polishing were easy.

Next, the hard polymer contained in the molded product was removed in the same manner as in Example 1, and when it was dried, the surface was sufficiently polished and a transparent contact with the same elasticity as the soft material that was the raw material was obtained. A molded product with a lens shape was changed.

Comparative Example 4 An attempt was made to cut the urethane rubber ADAPT-80L used in Example IO, but such cutting was not possible.

[Effects of the Invention] As explained above, according to the processing method of the present invention, soft materials, which are normally impossible to cut, can be easily manufactured with high precision without requiring a large amount of equipment or cost.

Furthermore, it is possible to produce a large number of molded products from a small amount of soft material.

In addition, when producing very small molded products, it is possible to process them in a swollen state with high precision.

Also, for example, when cutting plastics such as polymethyl methacrylate, which is commonly known as a raw material for hard contact lenses in the contact lens field, the material may chip or crack during processing due to the inherent brittleness of plastics. However, the blend obtained from the present invention also has the properties of a plastic reinforced with a soft material, so it has excellent impact resistance and eliminates the brittleness peculiar to plastics. is also possible. Therefore, no chips or cracks occur during cutting.

Furthermore, according to the processing method of the present invention, it is also possible to easily process a composite contact lens, which is known in the field of contact lenses and has a hard center and a soft peripheral contact lens.

Claims (1)

[Claims] 1. Processing of a soft ophthalmic lens material, characterized by removing the hard polymer from a molded product obtained by cutting a polymer blend consisting of a soft material and a hard polymer into a desired shape. Method. 2. The method of processing a soft ophthalmic lens material according to claim 1, wherein the polymer blend is obtained by impregnating a soft material with a monomer that provides a hard polymer and then polymerizing the monomer.