WO2014002966A1

WO2014002966A1 - Colored contact lens and process for producing same

Info

Publication number: WO2014002966A1
Application number: PCT/JP2013/067296
Authority: WO
Inventors: 師　俊也; 岡田　務; 横田知章
Original assignee: 株式会社メニコンネクト
Priority date: 2012-06-27
Filing date: 2013-06-24
Publication date: 2014-01-03
Also published as: JP5621118B2; JPWO2014002966A1; KR101645486B1; KR20150011390A

Abstract

The present invention addresses the problem of providing a colored contact lens which eliminates discomfort that arises when the color of the pupil of the wearer's eye and the colored pattern of the lens are simultaneously seen. This colored contact lens is characterized by comprising a copolymer obtained by copolymerizing a monomer mixture that comprises 30-99.5 parts by weight of a hydroxylated (meth)acrylate, 0-15 parts by weight of a (meth)acrylamide monomer and/or an N-vinylamide, 0-1 part by weight of a carboxylated monomer, and 0-70 parts by weight of other desired monomer(s). The colored lens is further characterized in that the difference between the lens diameter at 35ºC and the lens diameter at 20ºC is 0.5 mm or less and the difference between the lens diameter at pH 7.0 and the lens diameter at pH 3.0 is 0.5 mm or less.

Description

Colored contact lens and manufacturing method thereof

The present invention relates to a colored contact lens that can objectively change the color and texture of a pupil of a contact lens wearer and gives a natural appearance, and a manufacturing method thereof.

A contact lens (hereinafter simply referred to as “lens”) having a coloring pattern that can change the appearance of the wearer's eyes is for enjoying fashion rather than for correcting vision. Therefore, there are many proposals regarding a coloring pattern considering a visual effect.

As the coloring pattern, at least two different coloring patterns are provided on the mold surface and transferred onto the surface of the lens that contacts the mold surface during molding and curing of the contact lens (Patent Document 1), and the two colored portions have different hues. With a pattern that touches with a jagged boundary area, two subpatterns with different shadow ratios, and a subjective subpattern with a pattern consisting of a series of radial intermittent line patterns, three parts It has an iris section consisting of, and by appropriately setting the range of each section, an overlapping area is generated at multiple places, and it has a very natural appearance, used with a corneal rim ring and a fibrous dot pattern That emphasizes the sharpness of a person's iris, and the colored area has a shape such as circle, ellipse, triangle, or linear It is al structure, and the like having a color that changes gradually in a radial direction.

These designs can give the intended color to a third party by concealing or partially using the iris colors and patterns of the wearer. However, if the timing of the eye movement associated with the wearer's blink or line of sight and the movement of the lens on the cornea are out of sync, the wearer's own eye color and lens coloring pattern are observed at the same time. (Hereinafter, sometimes referred to as “discomfort in appearance”). In particular, it seems to occur easily when blinking strongly or moving eyes suddenly, but it is basically difficult to deal with such a sense of discomfort by devising only the coloring pattern.

Rotating the lens on the cornea or moving up, down, left, and right greatly influences the physical properties based on the lens material, the lens diameter, and the lens edge design. As for the physical properties of the lens, a material having higher surface hydrophilicity promotes smooth movement of the lens through the tear film between the surface of the cornea and the Young's modulus: y of the lens material is 0. 2 MPa ≦ y ≦ 2.0 MPa, and the average thickness of the peripheral portion: Tm is set to 0.05 mm ≦ Tm ≦ 0.30 mm (that is, the peripheral portion thickness dimension and the Young's modulus of the lens material) (Patent Document 2) is known to allow an appropriate movement of the lens. In general, it is said that the larger the lens diameter, the less the movement.

On the other hand, with respect to the lens design, a lens having a portion in which tears are stored inside the bevel on the rear surface of the lens and outside the optical field in order to prevent the movement of the lens and adhesion to the cornea (Patent Document 3), A lens having a lens size in the range of 14.1 to 14.6 mm and a blend width in the range of 0.28 to 0.5 mm in order to improve deviation, uneven distribution, and delay in lens movement (Patent Document 4), sharp A lens in which the outer peripheral end surface and the inner surface of the peripheral portion are configured with corners of a specific shape so that an excellent lens movement and a good wearing feeling can be obtained compared to an edge or a round edge (Patent Document 5), etc. There are suggestions. Also, for bifocal lenses that require lens orientation on the cornea, posture stabilization during lens wearing is achieved by prism ballast that does not rotate by blinking but quickly returns to the original direction even if it rotates. There is also an accomplished proposal (Patent Document 6). These proposals are all related to the movement of the lens, but are not made for the purpose of eliminating the uncomfortable feeling in the colored lens.

In addition, regarding the manufacturing method of the colored lens, the colored monomer component was coated on the portion forming the iris portion on the surface of the lens molding die, the film was formed, and then the lens monomer component was filled and polymerized and taken out from the die. In some cases, there are a method in which a colored lens is formed (Patent Document 7), a lens in which a colored portion is embedded in a lens material (Patent Document 8), and the like. These are effective methods for producing colored lenses in terms of preventing the elution of colorants and ensuring the smoothness of the lens surface, but the proposal from the viewpoint of eliminating the uncomfortable feeling by designing the lens edge part. Has not been made.

JP-A-4-265710 Reissue WO2003 / 87920 JP-A-6-230320 JP-A-10-161070 Reissue WO2007 / 66666 JP-A-8-262376 Japanese Patent Laid-Open No. 2-134612 JP-A-3-15020

An object of the present invention is to provide a lens that eliminates a sense of incongruity that occurs when the color of the wearer's own pupil and the colored pattern of the lens are simultaneously observed in the colored lens. The purpose is to propose a new lens that comprehensively considers physical properties, lens edge design and the like.

The present invention relates to a water-containing colored lens for changing the appearance of a wearer's pupil, comprising 30 to 99.5 parts by weight of a hydroxyl group-containing (meth) acrylate, a (meth) acrylamide monomer and / or N-vinylamide. A copolymer obtained by copolymerizing a monomer mixture, containing 0 to 15 parts by weight, 0 to 1 part by weight of a carboxyl group-containing monomer, and 0 to 70 parts by weight of another optional monomer, The difference between the lens diameters at 0 ° C. and 20 ° C. is within 0.5 mm, and the difference between the lens diameters at pH 7.0 and pH 3.0 is within 0.5 mm.

The colored lens is made of a polymer obtained by copolymerizing a predetermined monomer mixture. The “monomer” of the present invention refers to a polymerizable low molecular weight compound or high molecular weight compound, and includes a macromonomer having a polymerizable functional group. Therefore, “other optional monomers” include monomers other than the above (hydroxyl group-containing (meth) acrylate, (meth) acrylamide monomer, N vinylamide, carboxyl group-containing monomer), such as alkyl (meth) acrylate and styrene monomer. , A polysiloxane macromonomer, a silicone-containing alkyl (meth) acrylate, a polyfunctional monomer, and the like can be appropriately selected from conventionally known monomers that have been used for lens materials.

It is preferable that the colored portion is present within 5 μm or more from the surface of the lens, and the portion is not exposed on the inner or outer surface of the lens. In order to conceal the lens wearer's iris and objectively change the color or texture of the pupil, an opaque material such as iron oxide or titanium oxide can be used as the colored portion. As a result, there is a difference in physical properties between the material constituting the lens body and the colored portion, which may deteriorate the feeling of wearing or elution of the colored components. In order to avoid such a problem, it is preferable to employ a structure in which the colored portions are sandwiched by lens materials.

Furthermore, the difference in lens diameter between 35 ° C. and 20 ° C. is within 0.5 mm, and the difference in lens diameter between pH 7.0 and pH 3.0 is within 0.5 mm. This is a characteristic of the lens. As will be described in detail later, if the variation in the lens diameter is large, the lens is adsorbed to the cornea immediately after wearing (when the lens contracts more than before wearing), causing a greater risk of safety (than before wearing) This is because, when the lens swells, the movement of the lens becomes conversely large, and the uncomfortable appearance cannot be resolved.

The colored lens of the present invention has an outer peripheral end surface that is convex toward the outer peripheral side and has an acute-angled cross-sectional shape, and a radial cross-sectional view of the lens peripheral part (the lens from the inner surface side to the outer surface side). The angle α between the tangent of the edge to the curved surface on the inner surface side of the lens periphery and the tangent of the edge to the curved surface on the outer surface side of the periphery is 5 ° ≦ α ≦ 45 ° in FIG. It is a feature. So-called sharp edges are preferred. By adopting such an edge design, there is an effect of eliminating an excellent wearing feeling and an uncomfortable appearance that was not necessarily sufficient in the prior art.

As the manufacturing method of the colored lens, (a) a space formed by combining a first mold and a second mold designed to produce a semi-finished product having a smaller thickness and a smaller outer diameter than the polymerized lens. A step of filling and polymerizing the first monomer mixture, (b) a step of opening the first mold and the second mold, (c) a step of applying a coloring component to the exposed surface of the semi-finished product, (d) Filling and polymerizing a second monomer mixture in a space formed by combining one mold to which the semi-finished product designed to manufacture the polymerization lens is fixed and a third mold. Is preferred. The second monomer mixture preferably has the same composition as the first monomer mixture, and both are formulated within the scope described herein.

The “polymerized lens” refers to a contact lens manufactured by a mold manufacturing method and in a state immediately after the polymerization process and immediately before releasing. The mold manufacturing method includes a so-called wet mold manufacturing method in which a diluent or the like is added to the monomer mixture in advance to compensate for polymerization shrinkage, and a dry mold manufacturing method in which no diluent is added. For example, a lens manufactured by a dry mold manufacturing method does not contain water yet in a state where it is taken out from a mold, but becomes a contact lens product that swells in size due to the water-containing treatment and is distributed in the market. Even in a lens manufactured by a wet mold manufacturing method, after taking out from the mold, the diluent is replaced with water, so that the product is in a water-containing state. Therefore, the lens size immediately after taking out from the mold is generally different from the lens size marketed as a product. In the present specification, the “polymerized lens” is defined as described above, and the criteria for comparing the size in the manufacturing process are clarified.

The “semi-finished product” is a product in a state before it is obtained as a polymerized lens, and a lens as a finished product cannot be obtained even if it is treated with water. The feature of this production method is that the outer diameter of the layer polymerized in the step (a) is set smaller than the outer diameter of the layer polymerized later. That is, the layer that is polymerized first always has a smaller outer diameter than the layer that is polymerized later, and is preferably smaller by a difference of 5 to 4000 μm. In lenses manufactured by this method, the later polymerized layer will form the edge of the contact lens product. As a result, there is an effect that deformation of the lens when the product is manufactured can be suppressed.

In the step (c), a coloring component is applied to the surface not bonded to the mold of the semi-finished product. Thereafter, since the second monomer mixture is polymerized so as to cover the coloring component, it is possible to manufacture a colored lens having a sandwich structure sandwiched between the semi-finished product and the polymer of the second monomer mixture.

The water-containing colored lens according to the present invention is obtained by copolymerizing a predetermined monomer component, and changes in the lens diameter due to temperature change and liquidity (pH) are small. Since the movement is stabilized within an appropriate range, it is possible to suppress an uncomfortable appearance. In addition, when a so-called sharp edge design is adopted for the lens edge, the lens fits into the cornea and moves on the cornea, so foreign matter such as dust is not mixed in and the wearing feeling is further improved. The discomfort with respect to can be effectively eliminated. In general, if the movement of the lens on the cornea is too small, there is a high possibility that the lens will adsorb to the cornea and induce corneal damage. However, the water-containing colored lens according to the present invention has a temperature change and liquidity ( Since there is little change in the lens diameter due to (pH), even if a sharp edge design is adopted, the lens movement on the cornea can be prevented from becoming too small. Further, since the colored portion is inside the lens material and does not appear on the surface, a lens with excellent wearing feeling and high safety can be obtained.

According to the manufacturing method of the colored lens, since the layer to be polymerized first is set smaller than the outer diameter of the layer to be polymerized later, each layer is seamlessly connected. Generation | occurrence | production of a burr | flash etc. can be suppressed effectively. According to the manufacturing method, it is not necessary to prepare separate processes of different systems, and the manufacturing is completed in a series of flows by the mold manufacturing method, so that a lens with improved added value can be provided at a low price.

FIG. 1 is a diagram showing a cross section in the radial direction of the periphery of an example of the colored lens of the present invention. FIG. 2 is a diagram for explaining an example of the manufacturing process of the colored lens of the present invention. FIG. 3 is a diagram showing a cross section in the diameter direction of an example of the colored lens of the present invention.

The present invention relates to a water-containing colored lens obtained by copolymerization of a monomer mixture having a specific composition and a method for producing the same. The lens on a cornea is controlled by a sharp edge design by suppressing changes in lens diameter due to temperature and liquidity. It is characterized by stabilizing the movement of Hereinafter, preferred examples of the colored lens of the present invention and then the production method thereof will be sequentially described.

The colored lens of the present invention has a hydroxyl group-containing (meth) acrylate of 30 to 99.5 parts by weight, a (meth) acrylamide monomer and / or N-vinylamide of 0 to 15 parts by weight, and a carboxyl group-containing monomer of 0 to It consists of a copolymer obtained by copolymerizing a monomer mixture containing 1 part by weight and 0 to 70 parts by weight of other optional monomers.

Hydroxyl group-containing (meth) acrylate is a monomer that is a main component of a colored lens. For example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, dihydroxybutyl (meth) acrylate, diethylene glycol Examples thereof include mono (meth) acrylate, triethylene glycol mono (meth) acrylate, dipropylene glycol mono (meth) acrylate, polyethylene glycol (meth) acrylate, and glycerol (meth) acrylate. Examples of the fluorine-substituted monomer include 3- (perfluoro-3-methylbutyl) -2-hydroxypropyl (meth) acrylate and 3- (perfluoro-5-methylhexyl) -2-hydroxypropyl (meth) acrylate. It can also be used. These may be used singly or in combination of two or more (in the present specification, the following description of various monomers, initiators, etc. is also used in combination of one or two or more unless otherwise stated. The points that can be used are common). Among the monomers exemplified above, 2-hydroxyethyl (meth) acrylate and glycerol (meth) acrylate are preferably used because they have a long history of use.

Hydroxyl group-containing (meth) acrylate imparts water content, surface water wettability, flexibility and the like to the colored lens. The amount is 30 to 99.5 parts by weight, preferably 50 to 99 parts by weight, more preferably 70 to 99 parts by weight, and most preferably 90 to 99 parts by weight. If the blending amount is less than the above range, it may be difficult to impart sufficient functions (such as water content).

(Meth) acrylamide monomers include N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) ) Acrylamide, N, N-methyl (ethyl) (meth) acrylamide, N, N-methyl (propyl) (meth) acrylamide and the like. Of these, N, N-dimethyl (meth) acrylamide is preferred from the viewpoint of actual use.

N-vinylamide includes N-vinyl-2-pyrrolidone, N-vinyl-2-piperidone, N-vinyl-2-caprolactam, N-vinylformamide, N-vinylacetamide, N-vinyl-N-methylformamide. N-vinyl-N-methylacetamide and the like. Among these, N-vinyl-2-pyrrolidone is preferable from the point of use record.

(Meth) acrylamide monomers and / or N-vinylamide are conventionally used for the purpose of imparting high water content and surface water wettability to lenses. In the present invention, it is preferable to keep these monomers to the minimum necessary. This is because these components are susceptible to fluctuations in the diameter of the lens under the influence of temperature. Therefore, in the present invention, it is used in the range of 0 to 15 parts by weight, preferably 0 to 10 parts by weight, more preferably 0 to 5 parts by weight, and most preferably 0 to 3 parts by weight.

Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid. Among these, acrylic acid and methacrylic acid are preferable in terms of actual use.

The carboxyl group-containing monomer imparts high water content, like the amide monomer. However, since the effect is largely due to the repulsive force between the negative ions in the molecule, the pH of the solution directly affects the lens diameter and greatly fluctuates. In the present invention, it is preferable to use these monomers with the minimum necessary amount, and the blending amount thereof is in the range of 0 to 1 part by weight, preferably 0 to 0.8 part by weight. Note that (meth) acrylic acid may be contained as an impurity in 2-hydroxyethyl (meth) acrylate, but it goes without saying that (meth) acrylic acid as an impurity is also included in the blending amount.

Examples of other optional monomers include linear, branched, and cyclic alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, tert-butyl (meth) acrylate, and cyclohexyl (meth) acrylate. And silicon-containing (meth) acrylates such as tris (trimethylsiloxy) silylpropyl (meth) acrylate, fluorine-containing (meth) acrylates such as 2,2,2-trifluoroethyl (meth) acrylate, and methoxyethyl (meth) acrylate Examples include alkoxy group-containing (meth) acrylates such as aromatic ring-containing (meth) acrylates such as benzyl (meth) acrylate.

Linear, branched, and cyclic alkyl (meth) acrylates generally improve the mechanical strength of the lens; silicon-containing (meth) acrylates impart oxygen permeability to the lens; fluorine-containing (meth) acrylates Has an effect to prevent adhesion of dirt on the lens surface; alkoxy group-containing (meth) acrylate improves the compatibility of the monomer mixture and imparts appropriate water wettability to the lens; aromatic ring-containing (meth) acrylate Since the refractive index of the lens can be increased, effects such as enhancement of visual acuity correction power are known even when the lens is thin. Furthermore, in order to improve oxygen permeability, silicon-containing styrene, silicon-containing alkyl fumarate, fluorine-containing alkyl fumarate, and the like can be blended.

Also, by adding a cross-linking agent such as ethylene glycol di (meth) acrylate or diethylene glycol di (meth) acrylate, there are effects such as improvement of mechanical strength and shape stability and suppression of elution of low molecular weight polymers. In addition, a dye having a polymerizable functional group, an ultraviolet absorber, or the like can be added as an optional monomer. Further, one of these arbitrary monomers can be polymerized alone or a plurality of these monomers can be added.

The amount of these optional monomers is 0 to 70 parts by weight, preferably 0 to 50 parts by weight, more preferably 0 to 30 parts by weight, and most preferably 0 to 10 parts by weight. When the amount is more than the above range, the relative ratio of the hydroxyl group-containing (meth) acrylate as a main component is lowered, and there is a possibility that sufficient water content and hydrophilicity cannot be imparted. In addition, when manufactured in a wet mold or the like, a solvent that does not directly participate in polymerization may be added to the monomer mixture, but these solvents do not affect the physical properties of the lens. It is excluded from the components of the colored lens of the present application.

For the copolymerization of the monomer mixture in the present invention, a known method can be adopted. For example, thermal polymerization by heating by adding a radical polymerization initiator, photopolymerization irradiated with light such as ultraviolet rays, or a combination thereof. In thermal polymerization, the temperature is gradually raised from around room temperature, and heat in a temperature range of 30 ° C. to 120 ° C. is applied for several minutes to several hours. On the other hand, in the case of photopolymerization, polymerization proceeds by irradiation with active energy such as ultraviolet rays and electron beams. These polymerization methods and initiators can be selected as appropriate in consideration of the monomer mixture and the mold material.

Examples of the radical polymerization initiator include azobisisobutyronitrile, azobisdimethylvaleronitrile, benzoyl peroxide, cumene hydroperoxide, and the like. Examples of the ultraviolet polymerization initiator that can be used include benzoin isopropyl ether, benzophenone, benzoin, and benzoin methyl ether. The amount of these used is about 0.01 parts by weight or more, preferably about 0.1 parts by weight or more with respect to 100 parts by weight of the total amount of the monomer mixture. This is because the following tends to take time for polymerization. Further, if the amount used is too large, the resulting polymer tends to contain bubbles and distortion, so about 5 parts by weight or less, preferably 2 parts by weight with respect to 100 parts by weight of the total amount of the monomer mixture. Less than or equal to

In the colored lens of the present invention, the colored portion is preferably within 5 μm or more from the surface of the lens, and a specific production method will be described later, but is produced by mold polymerization. This is because the lens material is manufactured so that the colored portion is sandwiched between the lens materials, and the lens is excellent in wearing feeling and highly safe.

Examples of coloring components include phthalocyanine blue, cobalt blue, phthalocyanine green, chromium oxide, various iron oxides for red, yellow, brown and black, and the like. In addition, a pattern or the like can be shown using various dyes on an opaque white base containing titanium dioxide, aluminum oxide and the like. These coloring components can be used by being dispersed in the monomer or solvent. It is important that these colored components are embedded within 5 μm or more from each surface (inner surface side and outer surface side) of the lens so that they do not elute or come into direct contact with eye tissues such as the cornea and eyelids. That's it.

When the colored lens of the present invention is in a water-containing state, the difference between the lens diameter in 35 ° C. ISO physiological saline and the lens diameter in 20 ° C. ISO physiological saline is within 0.5 mm, preferably within 0.25 mm. It is. This indirectly indicates how much the size of the lens in the preservation solution changes when worn on the eye. When this difference becomes large, for example, when the eye contracts when worn on the eye, the lens tends to be adsorbed to the cornea, and there is almost no movement of the lens. On the other hand, if the lens swells when worn on the eye, the lens is not stable on the cornea, making fitting difficult, and making it difficult to avoid an uncomfortable appearance.

In order to suppress the change in the size of the lens due to the temperature, it is preferable that among the copolymer components of the colored lens, the component having a high degree of contribution to the temperature change, that is, the composition ratio of the (meth) acrylamide monomer is low. On the other hand, it may be difficult to increase the water content of the lens only with the hydroxyl group-containing (meth) acrylate, and the insufficient water content can be increased by using the (meth) acrylamide monomer. Therefore, in order to make the change in size due to temperature within the above range, the hydroxyl group-containing (meth) acrylate: (meth) acrylamide-based monomer is 100: 30 to 100: 0, preferably 100: 15 to 100: 0, more preferably in the range of 100: 8 to 100: 0.

In addition, when liquids with physiological saline pH adjusted to 7.0 and 3.0 are prepared and the colored lens of the present invention is immersed at 20 ° C., how much the lens diameter changes depending on the liquidity. Check out. It can be said that when the lens in the preservation solution is worn on the eye, how much it changes due to the difference in ion concentration or pH in the tear fluid. And as in the above temperature, such a change in size directly affects the movement of the lens on the cornea, so the difference is within 0.5 mm, preferably within 0.25 mm.

In order to suppress the change in the size of the lens at each pH, it is preferable to lower the composition ratio of the carboxyl group-containing monomer among the copolymer components of the colored lens. On the other hand, the moisture content of the lens is dramatically increased by the addition of this component. Therefore, in consideration of the balance between improving the water content and suppressing the size change of the lens at each pH, the hydroxyl group-containing (meth) acrylate: carboxyl group-containing monomer is in a weight ratio of 100: 2 to 100: 0, It is preferably used in the range of 100: 1 to 100: 0, more preferably 100: 0.7 to 100: 0.

Furthermore, in addition to the above physical properties, it is desirable that the outer peripheral end face of the colored lens has an acute cross-sectional shape over the entire circumference. More specifically, as shown in FIG. 1, the tangent line (3) of the edge to the curved surface (2) on the inner surface side of the lens peripheral portion in the radial sectional view of the lens peripheral portion (1), and the peripheral portion outer surface side If the angle formed by the edge tangent (5) to the curved surface (4) is (α), the sharp edge such that 5 ° ≦ α ≦ 45 °, preferably 20 ° ≦ α ≦ 40 ° is satisfied. Is to have a design. When the angle is smaller than the above-mentioned angle, the movement of the lens decreases, and there is a tendency that tear fluid exchange under the lens is insufficient. On the other hand, if the angle is larger than the above-mentioned angle, the movement of the lens due to blinking becomes too large, and it becomes difficult to eliminate the uncomfortable appearance due to the colored lens wearing.

Even if α is 5 ° ≦ α ≦ 45 °, if the lens diameter shrinks during wearing due to the influence of temperature, pH, etc., the movement of the lens is reduced and tear fluid exchange under the lens is insufficient. Tend. Therefore, α is 5 ° ≦ α ≦ 45 °, the difference in lens diameter between 35 ° C. and 20 ° C. is within 0.5 mm, and the difference in lens diameter between pH 7.0 and pH 3.0 is within 0.5 mm. It is preferable.

As shown in FIG. 1, the tip (6) of the edge does not need to be rounded (R is formed). Such an edge can be formed when both the concave and convex curved surfaces are in line contact with each other at the time of manufacturing the lens. This is because when the edge tip is not rounded, the lens enters between the cornea and the eyelid without a sense of resistance and is held at a stable position. However, it is not an essential requirement that there is no Earl. The colored lens having the physical properties defined in the present invention preferably has no edge radius, but if the curvature radius of the edge is 20% or less, preferably 10% or less, more preferably 5% or less of the edge thickness, blinking will occur. It is possible to effectively eliminate the uncomfortable feeling that occurs when the eyes of the wearer and the color pattern of the lens are observed at the same time.

In the cross-sectional view as shown in FIG. 1, the region for forming the sharp edge of the present invention is 0.1 to 0.3 mm from the edge tip on the inner surface side of the lens peripheral portion, and 0.1 to 0.3 It is formed with a length of 0.3 mm (the shaded area in FIG. 1 is the edge region). This is because if the length is shorter than the length, the function as a lens edge cannot be exhibited, and if the length is too long, the optical portion for correcting the visual acuity becomes relatively small, which is not preferable.

The thickness (L) of the edge region is appropriately set in the range of 0.05 to 0.25 mm, and this thickness may be uniform over the entire periphery of the lens. In addition, when the colored lens is a toric lens, the upper and lower parts of the lens are set thinner than other areas in order not to deviate the correspondence between the corneal astigmatism axis and the toric lens axis. You may do it.

Now, a method for producing a colored lens having the above physical properties and design will be described below. FIG. 2 shows a process for manufacturing the colored lens of the present invention. First, the first mold (11) and the second mold (12) are prepared. In this figure, the first type is a female type and the second type is a male type, but this may be reversed. Any one may be considered as the first type and the other as the second type. The mold material used in the present invention is molded from a general-purpose thermoplastic resin. For example, polypropylene, polyethylene, polystyrene, polycarbonate, polyethylene terephthalate, polyamide, polyacetal, polyvinyl chloride, and the like can be used. A combination of these resins can be used for each mold, or a mold molded from the same resin material can be used. As the resin, polypropylene, polystyrene, polyamide and the like are preferably used for reasons such as excellent price, transparency and moldability. In addition to the injection molding, a known method such as compression molding or vacuum molding can be appropriately employed as the molding method for each mold.

Among the prepared molds, fill the first monomer mixture (16) into the female mold ((a-1) in FIG. 2). Next, polymerization is performed in the space (14) formed in combination with the male mold ((a-2) in FIG. 2). The obtained polymer becomes a semi-finished product (15) having a thinner thickness and a smaller outer diameter than the polymer lens (20) finally obtained by the mold production method. The thickness of the semi-finished product is not necessarily constant. Although the thickness of the semi-finished product cannot be generally described, it is preferable that the thickness of the semi-finished product is at least 5 μm when it is hydrated and is 5 μm or more thinner than the thickness of the lens product when it is hydrated. This is because the colored portion is sandwiched between lens materials. Note that (a-1) and (a-2) in FIG. 2 are collectively referred to as (a) step.

The outer diameter of the semi-finished product is 5 to 4000 μm smaller than the outer diameter of the polymerized lens, preferably 10 to 2000 μm smaller, more preferably 15 to 1000 μm smaller. This manufacturing method is characterized in that the outer diameter is designed to be “small” in this way. This is because by using the second monomer mixture to be polymerized later for forming the outer edge of the lens, deformation of the lens, loss of edge portions, generation of burrs and the like after mold polymerization are effectively suppressed.

The reason for this is not clear, but the inventors think as follows. If the outer diameter of the semi-finished product is smaller than the outer diameter of the polymerized lens, the previously polymerized layer will be included in the space for forming the later polymerized layer. At this time, the male mold and the female mold can be brought into contact with the entire circumference of the lens end. When a liquid that forms a layer to be polymerized later is polymerized in this state, the contact portions of both molds are caused by polymerization shrinkage. You will be in closer contact. Accordingly, the lens and the polymer of the extra annular portion on the outside are completely separated at the tip of the lens edge.

On the contrary, if the layer to be polymerized first (semi-finished product) is larger than the outer diameter of the layer to be polymerized later, a part of the polymerized lens formed by the second monomer mixture and the surplus are caused by contact between the semi-finished product and the mold. Need to be separated. However, since the surplus is polymerized in contact with the edge portion formed by the semi-finished product, separation from the polymerized lens becomes difficult, and if it is separated excessively, defects such as defects, tears, scratches, etc. will occur in the lens. . Accordingly, when the layer that is polymerized first is set to be smaller than the outer diameter of the layer that is polymerized later, it is possible to effectively suppress the occurrence of deformation and burrs in the lens after manufacture.

One side of the semi-finished product (15) will constitute one side of the polymerized lens (20), while the other side is coated with a second monomer mixture that is polymerized later, It will be completed. Accordingly, when one side of the semi-finished product is intended to be used on the inner surface side of the polymerization lens, as shown in FIG. 2B, in the step of opening the first mold and the second mold, Is preferably selectively fixed to the male mold. On the contrary, when the semi-finished product is used on the outer surface side of the polymerization lens, it is preferable that the semi-finished product is selectively fixed to the female mold. As a method for reliably controlling such selectivity, (I) a material having a high adhesive force between the mold material and the semi-finished product is adopted as a mold material on the side to be fixed, and the other material is selected from a material having a low adhesive force. Molding method (for example, since the first monomer mixture contains a hydroxyl group-containing (meth) acrylate, one mold material is made of a hydrophilic mold material such as polyamide, and the other is a hydrophobic mold material such as polypropylene. Etc.). In addition, (II) First mold and second mold mold materials are made of the same material, and some treatment is performed on one mold surface (for example, applying plasma, UV irradiation, corona discharge, laser, or surfactant) The method of making it easy to adhere | attach a semi-finished product or to release a mold may be sufficient. Alternatively, (III) in the step (b) of the present invention, a method of opening a mold that is always selectively fixed to one mold (for example, a mold having a temperature gradient from the first mold to the second mold). Once opened, a method may be employed in which the semi-finished product is selectively left in the lower heat.

Since the surface of the semi-finished product and the surface of the first mold and the second mold are in an antisymmetric relationship (concave with respect to the convex surface and convex with respect to the concave surface), it is usually selective to one of the molds. The mold can be opened in a fixed state. The control method described above is a technique that enables more reliable control, and whether or not to adopt it may be determined based on comprehensive judgment such as cost.

The space (14) is filled with the first monomer mixture (16), but when another void containing an excess amount of the first monomer mixture combines the first and second molds. It may be formed. Although not shown in FIG. 2, it is because the shrinkage | contraction which can arise in a superposition | polymerization process can be suppressed by accommodating an excessive amount as a feeder. Other methods for avoiding the polymerization shrinkage include a method of adding a non-reactive substance that does not participate in the polymerization in advance to the polymerizable composition, and a method in which the first type and / or the second type can absorb the shrinkage. There is a method of using a material molded from a flexible material. In the step (a) of the present invention, one surface of the semi-finished product forms either the inner surface or the outer surface of the polymerized lens, but there is also a surface coated with the second monomer mixture. The surface to be coated with the second monomer mixture does not necessarily have an accurate surface shape, so the first mold or the second mold that will form this surface should have sufficient flexibility. It can absorb polymerization shrinkage. Further, it may be designed such that one mold is bitten into the other mold by polymerization shrinkage, and the polymer is separated into a lens and an outer annular portion. In order to reduce the amount of bite, it is also possible to add a certain proportion of a non-reactive substance that does not participate in the polymerization in advance to the polymerizable composition.

(B) After the mold is opened in step (b), the colored portion (21) is applied to the exposed surface of the semi-finished product (15) with a desired design (FIG. 2 (c)). The design can be an iris pattern with dots, lines, planes, or a combination thereof. As a coating method in the step (c), a conventional method can be appropriately employed, and examples thereof include screen printing, pad printing, and ink jet printing. Which application method is selected is determined in consideration of the physical properties of the coloring component, the physical properties of the semi-finished product, and whether the surface is convex or concave. After applying to the semi-finished product, it is desirable to fix the coloring component so as not to disperse by adding the second monomer mixture. There are various methods (heating, drying, electron beam irradiation, etc.) for fixing the coloring component, which can be selected as appropriate.

In order to conceal the lens wearer's iris and objectively change the color and texture of the pupil, thickeners for controlling fluidity such as iron oxide and titanium oxide as opaque materials are used as coloring components. Added. Furthermore, a monomer etc. can be added and it can be combined more firmly with the first and second monomer mixture. Since the sandwich structure is completely formed by the first and second monomer mixture, the elution of the coloring components is effectively suppressed. However, considering that the first and second monomer mixtures are separated via the coloring component, it is preferable to add a monomer or the like to the coloring component.

After coloring in step (c), the second monomer mixture (17) is poured into the third mold (13) (FIG. 2 (d-1)). In FIG. 2, since the mold is opened with the semi-finished product (15) fixed to the second mold (12), the second monomer mixture is poured into the third mold. When the mold is opened with the product fixed, the third mold is prepared as a convex mold instead of the second mold, and the second monomer mixture is poured onto the semi-finished product. Therefore, as shown in FIG. 2, the third mold is not necessarily a concave mold. (B) A mold in which the space formed in combination with the mold on which the semi-finished product of the process is fixed becomes the shape of a superposed lens is prepared as the third mold.

In the present invention, the first monomer mixture is distinguished as the first monomer mixture, and the later polymerization is differentiated as the second monomer mixture. However, the same composition may be used, or different compositions may be used. The first monomer mixture and the second monomer mixture can have different compositions as long as they do not cause deformation or distortion in the lens product. For example, in order to lightly color the whole lens, a dye is added to one side, methyl (meth) acrylate is added to the first monomer mixture, and 2,2,2-trifluoroethyl (meth) acrylate is added to the second monomer mixture. Can be used to make a difference in surface characteristics between the inner surface and the outer surface of the lens.

Since the mold material of the third mold, the molding method of the mold, and the like are the same as those of the first mold and the second mold, description thereof is omitted. In FIG. 2, after the second monomer mixture (17) is poured into the third mold (13), the second mold (12) to which the semi-finished product (15) is fixed and the third mold (13) are combined to form. The space (18) is filled with the second monomer mixture (17). By polymerizing this second monomer mixture (FIG. 1 (d-2)), a polymerized lens (20) is formed. The combination of (d-1) and (d-2) in FIG. 1 is referred to as step (d) in the present invention.

The polymerization method of the second monomer mixture, the polymerization initiator, the response to polymerization shrinkage, etc. are the same as those of the first monomer mixture. However, since the surface formed by the third mold is the surface of the polymerization lens, it is important to cope with the polymerization shrinkage. This is because the standard of the product is not stabilized by the avoidance by the flexibility of the mold material. FIG. 2 shows that the polymer lens (20) forms the semi-finished product (15) on the inner surface side and the polymer (19) of the second monomer mixture forms the outer surface side. Of course, this may be reversed, but there is no change in that the polymer (19) of the second monomer mixture forms the peripheral edge of the polymerized lens. A cross-sectional view of the superposed lens in the diameter direction is shown in FIG.

As shown in FIG. 3 (i), the semi-finished product (15) is smaller by (r1 + r2) than the outer diameter of the superposed lens (20). Although (r1 + r2) in FIG. 3 (i) and (r1 + r2) in FIG. 3 (ii) are shown to the same extent, they may be different. In the present invention, (r1 + r2) is in the range of 5 to 4000 μm as described above, preferably 10 to 2000 μm, and most preferably 15 to 1000 μm. In FIG. 3, r1 and r2 are the same, that is, the first semi-finished product (15) and the superposed lens (20) are concentric circles, but it is also possible to make the first semi-finished product eccentric by providing a difference between r1 and r2. It is.

Heretofore, a method for producing a colored lens having a sandwich structure in which a single color component is sandwiched between polymers of a first and second monomer mixture has been described. A colored lens having a sandwich structure sandwiched between the polymers of the second and third or higher monomer mixtures can also be applied several times by modifying some of the steps (a) to (d) described so far. Easy to manufacture.

For example, when manufacturing a colored lens having a sandwich structure in which a coloring component is sandwiched between layers of a three-layer structure composed of a polymer of first, second and third monomer mixtures, there are roughly two types. There is a way. One is to sequentially form layered structures. Specifically, in the steps (a) to (d) (however, in the step (d) in this case, not the polymerized lens, but the two-layer structure of the first semi-finished product and the second monomer mixture polymer with the colored portion sandwiched therebetween) (E) a process of opening the third mold and one mold (in this process, the second semi-finished product is either one of the molds). (F) a step of applying the second coloring component to the exposed surface of the second semi-finished product, and (g) a combination of the die with the second semi-finished product and the fourth die. This is a method of adding a step of filling the space with a third monomer mixture and polymerizing the mixture to obtain a polymerized lens. It is important that the second semi-finished product is thinner and smaller in diameter than the polymerized lens. In this method, if the second semi-finished product is fixed to the third mold in step (e), the polymer of the first monomer mixture is used as the intermediate layer, and the polymer of the second monomer mixture and the polymer of the third monomer mixture. However, each forms the inner and outer surfaces of the lens. Further, if the second semi-finished product is fixed to the mold other than the third mold in the step (e), the polymer of the second monomer mixture is used as an intermediate layer, and the polymer of the first monomer mixture and the third monomer mixture. Each of these polymers forms the inner and outer surfaces of the lens.

As another method, a first semi-finished product and a second monomer mixture polymer (hereinafter referred to as a third semi-finished product) are separately prepared and combined. Specifically, a first semi-finished product having a colored portion on the exposed surface is obtained in steps (a) to (c). Separately, the same steps (a ′) to (c ′) (in this step, the second monomer mixture is polymerized using the fourth type and the fifth type) are performed, and a third portion having a colored portion on the exposed surface is obtained. Get a semi-finished product. If the first semi-finished product is fixed to the convex shape in the step (b), the third semi-finished product needs to be fixed to the concave shape in the step (b ′). Moreover, it is also a condition that it is designed so that a polymerized lens is formed when a mold in which semi-finished products are fixed in both steps is combined. Furthermore, it is important that the first semi-finished product and the third semi-finished product are both thinner and smaller in diameter than the polymerized lens. Then, after the step (c) and the step (c ′), (h) the third monomer mixture is filled in the space formed by combining the molds to which the first semi-finished product and the third semi-finished product are fixed, and this is polymerized. Then, a step of obtaining a polymerized lens is added. In this method, using the polymer of the third monomer mixture as an intermediate layer, the polymer of the first monomer mixture and the polymer of the second monomer mixture respectively form the inner and outer surfaces of the lens.

By the above manufacturing method, coloring components are multi-layered, and more delicate patterns, three-dimensional patterns, and various colors can be expressed. Further, the colored lens of the present invention is multilayered, and a thick layer containing a silicone component that increases oxygen permeability but is hydrophobic and reduces wearing feeling is low in oxygen permeability but hydrophilic and excellent in wearing feeling 2 It is also possible to manufacture a lens excellent in both oxygen permeability and wearing feeling by sandwiching with a thin layer containing a large amount of components such as HEMA.

In order to clarify the effect of the colored lens of the present invention as described above, a colored lens having a structure as shown in FIG. 3 (i) is created, and how the discomfort in appearance is eliminated. I verified.

(Example 1)
The colored lens according to the present invention was manufactured by the polymerization method shown in FIG. First, it adjusted with the following compositions as a 1st and 2nd monomer mixture (Example 1). As hydroxyl group-containing (meth) acrylate, 66 parts by weight of 2-hydroxyethyl methacrylate (2-HEMA), 33 parts by weight of glycerol methacrylate (GMA), ethylene glycol dimethacrylate (EDMA) as a crosslinking agent as other optional monomers 0.5 part by weight, 0.5 part by weight of 2-hydroxy-2-methyl-1-phenyl-propan-1-one (HMPP) as a UV initiator, and 10 parts by weight of glycerol (GE) as a solvent Blended.

The monomer mixture was put into a female mold made of polypropylene as the first mold, and a male mold made of polypropylene was also combined as the second mold, and irradiated with ultraviolet rays (365 nm, 1 mW / cm ² ) for 5 minutes. When the mold was opened, the semi-finished product was adhered to the second mold. The semi-finished product has a center part thickness of 0.024 mm and an outer diameter of 10.88 mm.

The colored component having the following composition was applied to the surface of the semi-finished product in an iris pattern using dots. The coloring components are 30 parts by weight of 2-HEMA, 40 parts by weight of iron oxide, 20 parts by weight of titanium oxide, and 10 parts by weight of thickener.

A polypropylene female mold was prepared as the third mold. If the second type and the third type are simply combined, a space serving as the outer shape of the superposed lens is formed. The outer diameter of the superposed lens is designed to be 10.92 mm. When the monomer mixture having the above composition is put in the third mold and combined with the second mold in which the semi-finished product is bonded, the semi-finished product and the monomer mixture are sealed in a state of contacting each other in the space. Become. Thereafter, the polymerized lens was polymerized under the same conditions as described above. The mold was opened, the polymerized lens was taken out, immersed in purified water to elute unreacted monomers, etc., and sufficiently eluted while exchanging purified water, and then immersed in ISO physiological saline at 20 ° C. The colored lens thus obtained had a colored portion at a position of 15 μm from the inner surface side and about 40 to 150 μm from the outer surface side.

The lens edge design formed by combining the second mold and the third mold has an outer peripheral end surface that is convex toward the outer peripheral side and has an acute-angle cross-sectional shape, and a radial cross-section of the lens periphery. In the figure, it was confirmed that the angle α formed by the edge tangent to the curved surface on the lens inner peripheral surface side and the edge tangent to the curved surface on the outer peripheral surface side was 35 °. The edge had a sharp edge shape with no rounded tip, and was formed with a width of 0.13 mm on the outer surface side and 0.13 mm on the inner surface side from the edge tip. The edge thickness was 0.05 mm.

On the other hand, as a comparative example, the following two types of monomer mixtures (comparative example 1 and comparative example 2) were prepared. As Comparative Example 1, 96 parts by weight of 2-HEMA and 3 parts by weight of methacrylic acid (MMA) as a carboxyl group-containing monomer were used, and the crosslinking agent and the UV initiator had the same composition as the monomer mixture of Example 1. . As Comparative Example 2, 79 parts by weight of 2-HEMA and 30 parts by weight of N-vinyl-2-pyrrolidone (NVP) as N-vinylamide were used, and the crosslinking agent and the UV initiator were the same as in the monomer mixture of Example 1 above. Of the composition.

The monomer mixtures of Comparative Examples 1 and 2 were mold-polymerized in the same manner as in the above Examples and immersed in ISO physiological saline at 20 ° C.

The three lenses of Example 1 and Comparative Examples 1 and 2 were prepared, and the diameters of the lenses when immersed in 20 ° C ISO physiological saline and 35 ° C ISO physiological saline were measured. The results are shown in Table 1.

Next, the three lenses of Example 1 and Comparative Examples 1 and 2 were immersed in 20 ° C. ISO physiological saline (pH = 7.0) and 20 ° C. physiological saline (pH = 3.0), respectively. The diameter of the lens was measured. The results are shown in Table 2.

As shown in Tables 1 and 2, the physical properties of the colored lens according to Example 1 are as follows. The difference in lens diameter between 35 ° C. and 20 ° C. ISO physiological saline is 0.18 mm, and pH 7.0 and pH 3. The difference in lens diameter at 0 was 0.12 mm.

Next, after confirming the safety of each lens prepared in accordance with Example 1 and Comparative Examples 1 and 2, a lens conforming to standards for volunteers was prepared, and a short wearing test was performed. As the wearing test, when the lens is worn intentionally, blinking is intentionally performed, and the degree of appearance of an uncomfortable appearance to the measurer is obvious C, when it is observed carefully, B The case where it was hardly understood even with careful attention was evaluated as A. The results are shown in Table 3.

As shown in Table 3, according to the colored lens according to the present invention, it can be seen that the discomfort in appearance is almost eliminated.

(Examples 2 to 8)
Three lenses of Examples 2 to 8 having the composition shown in Table 4 were prepared in the same manner as in Example 1 and immersed in 20 ° C. ISO physiological saline and 35 ° C. ISO physiological saline, respectively. The diameter of was measured. Table 5 shows the difference in average measured values between temperatures. Moreover, the diameter of the lens when immersed in ISO physiological saline (pH = 7.0) and physiological saline (pH = 3.0) at 20 ° C. was measured. The difference in average measured values between pH is also shown in Table 5.

As shown in Table 5, the physical properties of the colored lenses obtained in the respective examples are such that the difference in lens diameter between ISO physiological saline at 35 ° C. and 20 ° C. is 0.45 mm at maximum, pH 7.0 and pH 3 The difference in lens diameter at 0.0 was 0.38 mm. Table 6 shows the angle α and the average evaluation in the same wearing test for the lenses of each example.

As shown in Table 6, it can be seen that the colored lens according to the present invention almost eliminates the appearance of discomfort.

The present invention relates to a water-containing colored lens obtained by copolymerizing a monomer mixture having a specific composition in a colored lens and a method for producing the same, and comprehensively considers lens materials, lens properties, lens edge design, and the like. Propose a new lens. As a result, the lens diameter change due to temperature and liquidity is suppressed, and the movement of the lens on the cornea is stabilized by the sharp edge design, so the wearer's own pupil color and lens coloring pattern can be observed simultaneously. It is possible to effectively eliminate the sense of incongruity that occurs when it is performed.

DESCRIPTION OF SYMBOLS 1 Lens peripheral part 2 Curved surface of lens peripheral part inner surface 3 Curved tangent of lens peripheral part inner surface 4 Curved surface of lens peripheral part outer surface 5 Curved tangent of lens peripheral part outer surface 11 First type 12 Second type 13 First Type 3 15 Semi-finished product 16 First monomer mixture 17 Second monomer mixture 20 Polymerized lens 21 Colored portion

Claims

A hydrous colored contact lens that changes the appearance of the wearer's eyes,
30 to 99.5 parts by weight of a hydroxyl group-containing (meth) acrylate,
0 to 15 parts by weight of (meth) acrylamide monomer and / or N-vinylamide;
0 to 1 part by weight of a carboxyl group-containing monomer,
A copolymer obtained by copolymerizing a monomer mixture containing 0 to 70 parts by weight of another optional monomer,
The difference in lens diameter between 35 ° C. and 20 ° C. is within 0.5 mm,
A colored contact lens, wherein the difference in lens diameter between pH 7.0 and pH 3.0 is within 0.5 mm.
The outer peripheral end surface of the colored contact lens has a convex and acute cross-sectional shape toward the outer peripheral side, and the tangent of the edge to the curved surface on the inner surface side of the lens peripheral portion in the radial cross-sectional view of the lens peripheral portion; 2. The colored contact lens according to claim 1, wherein an angle α formed with an edge tangent to the curved surface on the outer peripheral surface side of the peripheral portion is 5 ° ≦ α ≦ 45 °.