Animal contact lens with colored portion and method for manufacturing the same

Abstract

To provide a method for manufacturing an animal contact lens that makes it easier to visually confirm whether the contact lens is worn from outside and further allows determination of the front and back sides of the contact lens, and to provide the animal contact lens.SOLUTION: The animal contact lens includes a colored portion including a first layer and a second layer respectively containing a first coloring component and a second coloring component different from the first coloring component, the second layer being on the first layer. The animal contact lens includes a colored portion that is substantially annular and includes a first layer and a second layer respectively containing a first coloring component and a second coloring component different from the first coloring component, the second layer being on the first layer.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a contact lens having a colored portion for use in animals other than humans, and a method for manufacturing the same. [Background technology]

[0002] When animals feel itchy, such as dogs and cats, they will try to relieve the itch by rubbing their face against something or scratching with their front paws. However, these actions can easily damage the eye tissue, especially the cornea. Furthermore, these animals' eye tissues can also be damaged in everyday life by touching grass or branches while on a walk, or by owners wiping them with a towel after shampooing.

[0003] When a dog or cat's cornea is injured, the owner or veterinarian will attempt to treat the cornea by administering medication or applying ointment. In this case, wearing contact lenses in addition to administering medication can prevent the corneal injury from coming into contact with the outside world.

[0004] However, for animals such as dogs and cats, contact lenses are nothing more than foreign bodies. Animals wearing contact lenses often scratch the area around their eyes with their front paws to remove the contact lenses themselves, making it difficult to properly treat animals using contact lenses because they are unable to retain the contact lenses in their eyes. To solve this problem, owners are required to visually check on a daily basis that contact lenses are properly fitted in their animals' eyes.

[0005] However, because contact lenses are transparent, it is difficult to visually confirm from the outside that the contact lens is properly worn in the eye of an animal. Therefore, in order to distinguish the presence or absence of the contact lens from the outside when worn, veterinary contact lenses that have a plurality of dots colored with dyes or pigments that satisfy predetermined conditions on the surface or inside of the contact lens are known (see, for example, Patent Document 1), and are actually commercially available (see, for example, Non-Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-122188 [Non-patent literature]

[0007] [Non-Patent Document 1] “Meni-one Corneal Bandage Wan”, [online], Meni-one Co., Ltd., [Retrieved February 2, 2023], Internet <URL: https: / / www.meni-one.com / detail_01A-medical / C1-1_cornealbandage.php Summary of the Invention [Problem to be solved by the invention]

[0008] The veterinary contact lenses described in Patent Document 1 and Non-Patent Document 1 have a single colored dot, which is the visible part, and therefore it is difficult to distinguish the color on the front (front curve surface; FC) side and the back (base curve surface; BC) side of the contact lens, and there is a problem in that it is difficult to distinguish the front and back of the contact lens from the outside when worn.

[0009] Furthermore, the veterinary contact lenses described in Patent Document 1 and Non-Patent Document 1 use several dots spaced apart within a circular region as the visual identification area. However, even when wearing the veterinary contact lenses described in Patent Document 1 and Non-Patent Document 1, blinking causes the contact lens to rotate around its optical axis, causing the visual identification dots to move under the eyelid, making it difficult to visually confirm the presence or absence of the contact lens from the outside. In particular, animals such as dogs and cats with injured corneas, like humans, squint to relieve pain, resulting in a narrower palpebral fissure than normal. In this case, even if the contact lens does not rotate within the eye, it is difficult to confirm the visual identification area. Therefore, the veterinary contact lenses described in Patent Document 1 and Non-Patent Document 1 still have the problem that it is difficult to externally confirm the presence or absence of a contact lens in an animal's eye, even with their visual identification area.

[0010] Therefore, the problem that the present invention aims to solve is to provide an animal contact lens that allows easier visual confirmation from the outside of whether or not the contact lens is present when worn, compared to the animal contact lenses described in Patent Document 1 and Non-Patent Document 1, and also allows for distinguishing between the front and back of the contact lens at this time, as well as a method for manufacturing such an animal contact lens. [Means for solving the problem]

[0011] As a result of extensive research into solving the above problems, the inventors discovered that by laminating coloring components of different colors in the colored portions to be placed on animal contact lenses, so that the color of the layer on the front side is different from the color of the layer on the back side, it is possible to visually distinguish from the outside whether the contact lens is present or not and whether it is front or back when worn.

[0012] Furthermore, by arranging the colored portion in an approximately annular shape so that it is concentric with the animal contact lens, even if the contact lens rotates around the optical axis due to blinking or the palpebral fissure width narrows, it was found that part of the colored portion remains outside the eyelid, making it easy to visually determine from the outside whether the contact lens is present or not and whether it is front or back when worn.

[0013] Based on the above findings, the inventors have finally succeeded in creating a contact lens for animals having a specific colored portion and a method for manufacturing the same, which solves the problems of the present invention. The present invention was completed based on the findings and successful examples first obtained by the inventors.

[0014] Therefore, the present invention provides the following aspects. [1] A contact lens for animals having a colored portion including a first layer and a second layer thereon, the first and second layer containing different coloring components, respectively. [2] A contact lens for animals, comprising a first layer containing first and second coloring components that are different from each other, and a second layer thereon, and having a colored portion that is approximately annular. [3] The approximately annular shape has a width of 0.1 mm to 3 mm and / or an area of ​​50 mm 2 ~200mm 2 The veterinary contact lens according to [2], [4] The lightness index L of the first coloring component * 1 and the lightness index L of the second coloring component * The contact lens for animals according to [1] or [2], wherein the difference ΔL from ΔL 2 is +2 or more or -2 or less. [5] The animal contact lens according to [1] or [2], wherein the difference ΔT between the coloring lightness T1 of the first coloring component and the coloring lightness T2 of the second coloring component is +600 or more, or -600 or less. [6] The veterinary contact lens according to [1] or [2], wherein the colored portion is provided on the surface or inside of the veterinary contact lens. [7] A method for manufacturing contact lenses for animals, comprising the following steps: (1) A step of obtaining a copolymer by subjecting a male mold to a copolymerization reaction, the step being performed by fitting a male mold into a female mold containing a contact lens-forming composition in its recess. (2) A step of forming a first layer containing a first coloring component on the surface of the copolymer in the convex portion of the male mold separated from the female mold, and further forming a second layer containing a second coloring component on the first layer to obtain a copolymer having a colored portion including the first layer and the second layer thereon, wherein the first coloring component is different from the second coloring component. (3) A step of fitting a male mold having the copolymer with the colored portion in the convex portion into a female mold having a contact lens composition in the concave portion to obtain a molding die, and subjecting the resulting molding die to a copolymerization reaction to obtain a contact lens substrate for animals having a colored portion. (4) A step of subjecting the animal contact lens substrate having the colored portion to a hydration swelling treatment to obtain an animal contact lens having the colored portion. [8] The method according to [7], wherein the veterinary contact lens is the veterinary contact lens according to [1] or [2]. [Effects of the Invention]

[0015] According to the contact lens for animals of one aspect of the present invention, the colored portion formed by laminating different coloring components makes it easy to visually check from the outside whether the contact lens is being worn or not, and to distinguish between the front and back.

[0016] Furthermore, according to one embodiment of the manufacturing method of the present invention, the colored portion is encapsulated in the contact lens substrate, and the coloring component used in the colored portion can be prevented from coming into direct contact with the surface of the eyeball, eyelids, etc., making it possible to manufacture safer contact lenses for animals. [Brief explanation of the drawings]

[0017] [Figure 1A] FIG. 1A is a plan view illustrating the surface of a veterinary contact lens in which the colored portion is a continuous ring. [Figure 1B]FIG. 1B is a plan view illustrating the surface of a veterinary contact lens in which the colored portions are discontinuous annular portions. [Figure 1C] FIG. 1C is a plan view illustrating the surface of a veterinary contact lens having discontinuous circular colored portions. [Figure 1D] FIG. 1D is a plan view illustrating the surface of a veterinary contact lens in which the outer edge of the colored portion is wavy. [Figure 1E] FIG. 1E is a plan view illustrating the surface of a veterinary contact lens having two continuous circular colored portions. [Figure 2] FIG. 2 is a top view (left) of the front surface (FC) of the veterinary contact lens of Example 1 and a bottom view (right) of the back surface (BC), as described in the Examples below. [Figure 3] FIG. 3 shows a magnified photograph (left) of the colored portion on the front surface (FC) of the veterinary contact lens of Example 1, as described in the Examples below, and a magnified photograph (right) of the colored portion on the back surface (BC). [Figure 4] As described in the Examples below, Figure 4 shows photographs of the veterinary contact lens of Example 1 taken from the back to the front at different angles (top image) and photographs of the front to the front at different angles (bottom image). [Figure 5] FIG. 5 shows a series of photographs taken from above of an artificial eye and contact lenses placed on the artificial eye with their front and back surfaces facing outward, as described in the Examples below. DETAILED DESCRIPTION OF THE INVENTION

[0018] Each aspect of the present invention will be described in detail below, but the present invention is not limited to the details of these items and can take various forms as long as the object of the present invention is achieved.

[0019] Unless otherwise specified, the terms used in this specification are used in the sense commonly used by those skilled in the art who handle ophthalmic devices such as contact lenses, and should not be construed as having an unduly limiting meaning. Furthermore, the speculations and theories made in this specification are based on the inventors' knowledge and experience to date, and therefore the present invention is not limited solely to such speculations and theories.

[0020] "Content" is synonymous with concentration and amount used (amount added), and refers to the ratio of the amount of a component to the total amount of the final product. However, the total amount of the component content does not exceed 100%. In this specification, unless otherwise specified, the unit of content is "mass % (wt%)." When a commercially available product is used, the content of the component is preferably the amount of the component contained in the commercially available product, but it may also be the amount of the commercially available product itself. The term "and / or" means any one or any or all combinations of two or more of the associated listed items. "Comprising" means that elements other than those explicitly stated as being included can be added (same meaning as "comprising at least"), but also encompasses "consisting of" and "consisting essentially of." That is, "comprising" can mean including the explicitly stated elements and any one or more elements, consisting of the explicitly stated elements, or consisting essentially of the explicitly stated elements. Elements include limitations such as ingredients, steps, conditions, and parameters. The use of "to" in a numerical range includes both the preceding and following numerical values, and also includes ranges excluding either of the included limits. For example, "0% to 100%" means 0% or more, 100% or less, or 0% or more and 100% or less. "About" means an amount within ±10% of the quantity following the term. For example, "about 100" means 100±10%, i.e., 90 to 110. The number of digits in an integer value matches the number of significant digits. For example, 1 has one significant digit, and 10 has two significant digits. Also, the number of digits after the decimal point in a decimal value matches the number of significant digits. For example, 0.1 has one significant digit, and 0.10 has two significant digits.

[0021] (Overview of contact lenses for animals) A first aspect of the present invention is a veterinary contact lens having a tinted portion including a first layer and an overlying second layer, the first and second layer containing different first and second tinting components, respectively. A second aspect of the present invention is a contact lens for animals, which includes a first layer and a second layer thereon, each containing a first and second coloring component that are different from each other, and which has a colored portion that is approximately annular.

[0022] Generally, when contact lenses are worn inside out, parts of the contact lens that normally do not come into contact with the surface of the eyeball come into contact with the surface, causing a foreign body sensation or discomfort. Furthermore, if contact lenses are worn inside out for a long time, the parts may injure the surface of the eyeball and cause inflammation. Therefore, it is necessary to wear contact lenses correctly, without turning them inside out.

[0023] However, in the case of contact lenses for animals, it is not possible for the animal wearing the contact lenses to check for proper fit, so it is necessary for a human being, such as an owner or veterinarian, to visually check from the outside that the animal is wearing the contact lenses correctly.

[0024] The veterinary contact lens of the first aspect of the present invention has a colored portion formed by laminating colored components of two different colors, allowing a human to visually confirm from the outside that the animal is wearing the contact lens correctly. That is, the veterinary contact lens of the first aspect of the present invention has a colored portion formed by laminating colored components of two different colors, and by making the colors of the front surface (upper layer) and back surface (base surface) (lower layer) of the contact lens different, a human can visually confirm from the outside that the animal is wearing the contact lens correctly.

[0025] On the other hand, when animals experience eye pain due to trauma, they squint, narrowing the palpebral fissure width. Therefore, when an animal wearing contact lenses experiences eye pain, the outer periphery of the contact lens will sink beneath the upper and lower eyelids in the vertical direction relative to the optical axis (the center of the contact lens). In this case, even if the contact lens has visible areas as several spaced dots within a circular region near the periphery, the contact lens will rotate circumferentially when the animal blinks while wearing it, and the visible dots may sink beneath the eyelids, making them invisible from the outside.

[0026] The animal contact lens of the second aspect of the present invention has a colored portion formed by laminating colored components of two different colors in a roughly annular shape. Therefore, even when the contact lens rotates around the optical axis inside the animal's eye, the colored portion always lies outside the under-eyelid to the left and right of the optical axis, making it easy to visually confirm from the outside that the animal is wearing the contact lens.

[0027] (Animal contact lenses) The first and second aspects of the animal contact lenses of the present invention have in common a colored portion including a first layer containing a first coloring component and a second layer containing a second coloring component different from the first coloring component and positioned on the first layer, wherein the first layer is positioned on the back surface of the contact lens and the second layer is positioned on the front surface of the contact lens.

[0028] The first and second coloring components are not particularly limited as long as they have different colors and can be used as colored portions to distinguish between the front and back of the veterinary contact lens. Preferably, the first and second coloring components have different colors, and therefore different lightness indices.

[0029] The brightness index is the brightness index L specified in the Japanese Industrial Standard JIS Z 8781-4:2013 * and is calculated using values ​​determined by the spectrophotometric colorimetry method specified in JIS Z 8722: 2009. Specifically, the lightness index is determined by the method described in the examples below.

[0030] Lightness index L of the first coloring component * 1 and the lightness index L of the second coloring component * The difference between 2 and ΔL (=L * 1-L * 2) is large as an absolute value, the front and back of the colored portion can be easily distinguished. ΔL is not particularly limited as long as it is a value that allows easy distinction between the front and back of the colored portion, but for example, in order to make it easier to distinguish between the front and back of the colored portion, ΔL is preferably +2 or more or -2 or less, more preferably +5 or more or -5 or less, even more preferably +10 or more or -10 or less, and still more preferably +13 or more or -13 or less.

[0031] It is possible to distinguish between the front and back of the colored portion even if the lightness index of either the first coloring component or the second coloring component is large. However, if the lightness index of the second coloring component is too high, there is a risk that the colored portion will be too bright and difficult to see. Therefore, the lightness index L of the first coloring component is set to 1. * 1 is the lightness index L of the second coloring component * It is preferable that ΔL is a value greater than 2, that is, that ΔL is a positive value. For example, it is preferable that the first coloring component is a white component and the second coloring component is a colored component such as orange, blue, or red.

[0032] In order to distinguish the colored portion from the iris color of the animal wearing the contact lens, the first colored component and the second colored component are lighter than the iris color of the animal, i.e., L * 1 and L * 2 is the lightness index L of the iris color of the animal * Preferably greater than 0. L * 1 and L * Although there are no particular limitations on 2, for example, when the animal has brown irises such as a dog, it is preferable that each of the values ​​is 30 or more, more preferably 40 or more, and even more preferably 50 or more. * 1 and L * The upper limit of 2 is not particularly limited, but is typically 90 or less.

[0033] In order to make it easier to visually confirm from the outside that the contact lens is being worn correctly by the colored portions, that is, to further increase the visibility of the colored portions, it is preferable that the first layer and the second layer each have a certain area. The area S1 of the first layer and the area S2 of the second layer are not particularly limited as long as they are values ​​that allow the colored portions to be visually recognized from the outside, but for example, 10 mm 2 ~500mm 2 Preferably, it is 50 mm 2 ~200mm 2 It is more preferable that the 2 ~150mm 2 S1 and S2 may be different from each other or may be the same, but are preferably the same in order to make it easier to distinguish between the front and back.

[0034] The visibility of the colored portion is determined by the lightness index L of the first coloring component. * The coloring brightness T1 (= S1 (mm 2 )×L * 1) and the lightness index L of the second coloring component * The coloring brightness T2 (= S2 (mm 2 )×L *2). The larger the values ​​of T1 and T2, the larger the area of ​​each layer and the brighter the coloring, resulting in higher visibility of the colored portion from the outside. Furthermore, if the absolute value of ΔT (= T1 - T2), which is expressed by the difference between the coloring lightness T1 of the first layer and the coloring lightness T2 of the second layer, is large, it becomes easy to distinguish between the front and back of the contact lens. From this perspective, ΔT is, for example, preferably +600 or more or -600 or less, more preferably +800 or more or -800 or less, even more preferably +1,000 or more or -1,000 or less, and even more preferably +1,500 or more or -1,500 or less.

[0035] Although T1 and T2 are not particularly limited, for example, in order to improve the visibility of the colored portion, they are each preferably 1,000 or more, more preferably 2,000 or more, even more preferably 4,000 or more, and still more preferably 6,000 or more. Although there are no particular upper limits for T1 and T2, they are typically 15,000 or less.

[0036] Whether the coloring lightness of the first layer or the second layer is high, it is possible to externally confirm whether the contact lens is being worn and to distinguish between the front and back, but using a coloring component with a high lightness index in the first layer has the effect of concealing the iris color. This allows the second layer to express the original color of the second coloring component without being affected by the iris color, so it is preferable that the coloring lightness T1 of the first layer is greater than the coloring lightness T2 of the second layer, i.e., ΔT is a positive value.

[0037] The coloring portion may include a first layer containing a first coloring component and a second layer containing a second coloring component, and may further include a third layer containing a third coloring component below the first layer. It is preferable that there is no other layer between the first and second layers, and it is more preferable that the coloring portion consists of the first and second layers. Each coloring component may be a single colorant or a combination of multiple colorants.

[0038] In the animal contact lens of the second embodiment of the present invention, the colored portion is arranged in a substantially circular ring shape in the circumferential direction of the contact lens. The substantially circular ring-shaped colored portion may be a continuous ring (e.g., FIG. 1A), an intermittent ring (e.g., FIGS. 1B and 1C), or an elliptical ring. When the substantially circular ring-shaped colored portion is an intermittent ring, the continuous ring is preferably 80% or more circular, more preferably 85% or more circular, and even more preferably 90% or more circular, assuming that the continuous ring is 100% circular. Furthermore, as long as the substantially circular ring-shaped colored portion is arranged in the circumferential direction of the contact lens as a whole, its outer edge may be wavy (e.g., FIG. 1D), zigzag, or the like.

[0039] The outer diameter and width of the approximately annular colored portion are not particularly limited as long as they result in the above-mentioned area, but for example, the outer diameter (maximum diameter) is preferably 5 mm to 12 mm, more preferably 7 mm to 11 mm, or is preferably 35% to 80% of the diameter of the contact lens, more preferably 50% to 75%; and / or the width is preferably 0.1 mm to 3 mm, more preferably 0.5 mm to 2 mm.

[0040] The location of the colored portion of an animal contact lens is not particularly limited as long as it avoids overlapping with the central optical portion so as not to obstruct vision. For example, from the perspective of reducing the discomfort caused by the colored portion when worn, it is preferable that the colored portion be located in the middle to near the outer edge in the direction from the center to the outer edge, and from the perspective of increasing visibility from the outside, it is more preferable that the colored portion be located near the middle.

[0041] The number of colored portions is not particularly limited and may be one or more. For example, two or more substantially annular colored portions may be arranged side by side with a gap in the circumferential direction of the contact lens. FIG. 1E shows two substantially annular colored portions arranged side by side with a gap in the circumferential direction of the contact lens. When there are two or more colored portions, the colors of the first layers may be the same or different, and the colors of the second layers may be the same or different.

[0042] The colored portion may be disposed on the surface, the interior, or both of the surface and the interior of the veterinary contact lens, and is not particularly limited thereto. However, the colored portion is not disposed on the rear surface of the veterinary contact lens to prevent contact with the eyeball. When it is desired to prevent the colored portion from coming into contact with eye tissues such as the eyelid, it is preferable to dispose the colored portion on the interior of the veterinary contact lens.

[0043] Even when the color of the second layer in the colored portion is similar to the color of the iris of an animal, the veterinary contact lens of one embodiment of the present invention allows for visual confirmation from the outside as to whether the contact lens is being worn or not and whether it is front or back. It is preferable that the ability to distinguish whether the contact lens is being worn or not and the front or back is evaluated as "good" in terms of the front / back distinguishability and external visibility described in the Examples below.

[0044] (Components of animal contact lenses) The animal contact lens of one embodiment of the present invention comprises at least a coloring component and a contact lens substrate as constituent components.

[0045] The colorant constituting the coloring component is not particularly limited, and examples thereof include dyes and pigments.

[0046] Dyes are classified into direct dyes, acid dyes, basic dyes, disperse dyes, reactive dyes, etc. based on their chemical structure and reactivity. The direct dye is not particularly limited, and examples thereof include Direct S Yellow RL, Direct S Red BWS, Direct Orange S, Direct Bordeaux GS, Direct Blue BB, Direct S Blue 4BL H / C, Direct S Blue BRL 200, Direct Sky Blue 5B, Direct Light Scarlet F2G, Direct Light Rose FR, Direct F Black B160, Sumilite S Blue FBGL, Sumilite S Blue FGL, Kayalas L Yellow F8G, Kayalas S Yellow GLS, Kayalas Yellow PG, Kayalas S Orange 2GL 125%, Kayalas S Bron B2R, Kayalas S Bron GL 125, Kayalas S Bron GTL, Kayalas L Red F5B, Kayalas S Rubin BL, Kayalas S Blue RCL, Kayalas S Blue 4G, Kayalas S Blue BWL 143, Kayalas T Blue GL, and Kayalas S Green. Examples include Kayalas C Green G, Kayalas S Gray L3R, Kayalas S Gray CGL, Kayalas S Scarlet BNL 200, Kayalas Light Scarlet F2G, Kayalas S Red 6BL 170%, Kayalas S Violet 5BL Concentrate, and Kayalas C Navy Blue CLW, and these may be used alone or in combination of two or more.

[0047] The acid dye is not particularly limited, and examples thereof include Kayanol Yellow NFG, Kayanol Yellow N3R, Kayanol M Yellow 5GW, Kayanol M Yellow O, Kayanol M Yellow 3GW, Kayanol M Scarlet FGW, Kayanol M Red 6BW, Kayanol M Violet FBW, Kayanol M Turquis Blue 3G, Kayanol M Black VLG, Kayanol M Green 5GW, Kayanol M Green GW, Kayanol Milling Blue GW, Kayanol Milling Blue BW, Kayanol M Violet FBW, Kayanol Milling Black TLB, Aminil Yellow E-3RL, Aminil Yellow E-3GL, Aminil Red E-3BL, Aminil Blue E-2GL, Kayakaran Scarlet GL, Kayakaran Bordeaux BL, Suminol F Yellow R Conc, Suminol F Yellow 2GP, Suminol F Black BR ​​Concentrate, Suminol F Yellow G, Suminol M Bordeaux B, Suminol M Brilliant Red B(N) Concentrate, Suminol M Brilliant Red 3BN Concentrate, Suminol M Red Brown V Concentrate, Ranil Black BG ex / co, Ranil Bron GR(N), Ranil Yellow R ex / co, Acid M Red PG, Acid M Red GRA, Acid M Red RS 125, Acid M Red 3BW, Acid Green SS 200, Acid M Green B, Acid Violet 4BNS, Acid M Cyanine 5R, Inola M Yellow NRG-N, Inola Scarlet BA, Inola F Cyanine 6B H / C, Inola F Violet 5B, etc., and these may be used alone or in combination of two or more.

[0048] The basic dye is not particularly limited, and examples thereof include Astra Phloxine FF Concentrate, Primo Flavin 8G, Methyl Violet BB, Methyl Violet Pure SP, Catilon Yellow 7GLH, Catilon B Yellow 5GLH200%, Catilon Yellow 3GLH200%, Catilon Yellow K-3RLH, Catilon Yellow SGLH, Catilon Yellow T-RLH, Catilon Orange GLH200%, Catilon B Red 4GH200%, Catilon Red 6BH, Catilon Red 7BNH200%, Catilon B Red 3BPH, Catilon Red CD-FBLH, Catilon Blue BRLH200%, Catilon Blue T-BLH, Catilon Blue CD-FBLH, Catilon Blue 3GLH, Catilon Black CD-BLH, and Catilon Black MH, Catilon Black NH200%, Astrazon Yellow 7GLL200%, Astrazon Yellow 8GSL200%, Astrazon Yellow GRL200%, Astrazon Red BBL200%, Astrazon Red 6B, Astrazon Red CS-N, Astrazon Red GTLN200% ​​01, Astrazon Blue BG200%, Astrazon Blue 5GL200%, Astrazon Blue AU-N02, Astrazon Black FDL200%01, Astrazon Black SW200%, etc., and these may be used alone or in combination of two or more.

[0049] The disperse dye is not particularly limited, and examples thereof include Dianix Br Yellow 5GE, Dianix Br Blue GRE, Dianix Br Navy Blue BNE, Dianix Br Black BNSE, Dianix Yellow 7GL200%, Dianix Yellow G-FS200, Dianix Red R-E167, Dianix Red BN-SE, Dianix Red G-FS, Dianix Red GR, Dianix Blue 3RLS, Dianix Blue FBL-E, Dianix Black BG-FS200%01, Dianix Black HG-FS Conc, Sumikaron Yellow SE5G, Sumikaron Bron G, Sumikaron Khaki GG, Sumikaron Olive MW, Sumikaron Violet S4RL ex / co, Myketone P Orange SF, Myketone P Red BSF, Myketone P Red BLSF, and Kayalon P Scarlet. RLSF, Kayalon P Rubin GLSE 200%, Kayalon P Black EXSF 200%, and the like, and these may be used alone or in combination of two or more.

[0050] The reactive dye is not particularly limited, and examples thereof include Remazol B Yellow 4GL, Remazol B Yellow GL, Remazol Yellow FG 150%, Remazol Yellow GNL, Remazol Yellow GR, Remazol G Yellow G, Remazol G Orange 4G, Remazol B Orange FR, Remazol B Orange 3R, Remazol B Red GG, Remazol B Red BB 150%, Remazol B Red F3B, Remazol Red RHG, Remazol Bold B, Remazol B Violet 5R 90%, Remazol B Blue RKN, Remazol B Blue BB 133%, Remazol Turquis B, Remazol Turquis G 133%, Remazol B Green 6B 175%, Remazol Navy RGB 150%, Remazol Black B 150%, Remazol Black DEN, and Remazol Black A, Remazol Black B, Sumifix Yellow 2GL 150%, Sumifix Yellow GR 150%, Sumifix G Yellow GG 150%, Sumifix Orange 3R 150%, Sumifix Red G 150%, Sumifix Red BB 150%, Sumifix Red BS, Sumifix Red 7BF 25%, Sumifix Blue R, Sumifix Blue KP, Sumifix Turquis Blue G, Sumifix N Blue EXF, Sumifix Black B 150%, Sumifix Black EX, Sumifix Black EA, Kayashion Yellow P-5G, Kayashion Yellow PN-3R, Mikasion Yellow 8GN, Kayashion Orange PG, Kayashion Brown P-4NR, Kayashion Scarlet P RN, Kayashion Red P-2B, Kayashion Red P-4BN, Kayashion Red A-3B, Kayashion Blue P-3R, Kayashion Blue AB, Kayashion Navy P-N2R, Kayashion Black PN, Cibacron Yellow P-6GS, Cibacron Orange P-2R, Cibacron Brown P-6R150, Cibacron Red P-B, Cibacron Red P-4B, Cibacron Red P-6B150, Cibacron Blue P-3R, CibacronBlack PGR 150% and the like, and these may be used alone or in combination of two or more.

[0051] Examples of pigments include natural mineral pigments, synthetic inorganic pigments, azo pigments, and polycyclic azo pigments. The inorganic pigments are not particularly limited, but examples include titanium oxide, zinc oxide, talc, silicic anhydride, magnesium silicate, bentonite, mica, bismuth oxychloride, magnesium oxide, yellow iron oxide, red iron oxide, ultramarine, chromium hydroxide, chromium oxide, and calamine. These pigments may be used alone or in combination of two or more. Examples of azo pigments include soluble azo pigments, sparingly soluble azo pigments, insoluble azo pigments, and condensed azo pigments. Examples of polycyclic pigments include phthalocyanine pigments, quinocridone pigments, dioxazine pigments, isoindolinone pigments, threne pigments, isoindoline pigments, lake pigments, perylene pigments, and metal complex pigments. These pigments may be used alone or in combination of two or more. The dye and pigment may be used alone or in combination. Since the inorganic pigment has a rainbow color-hiding effect, it is preferably contained in the first coloring component contained in the first layer, which is the lower layer.

[0052] The veterinary contact lens of one embodiment of the present invention is expected to be used as a bandage to protect ocular tissue when an animal suffers eye trauma. From this perspective, the veterinary contact lens of one embodiment of the present invention preferably has a contact lens substrate that is a flexible hydrogel.

[0053] Hydrogels are based on a polymer of monomer components including hydrophilic monomers. Hydrogels swell within a polymer matrix when exposed to an aqueous liquid, such as water or a solution containing water, and retain the aqueous liquid. In this specification, the polymer itself, excluding the aqueous liquid, is referred to as the contact lens substrate. Note that a polymer is formed by polymerization of monomers, and the structural units derived from each monomer in a polymer are also referred to as residues and moieties.

[0054] Specific examples of hydrogels include hydrogels produced using hydrophilic monomers, hydrogels produced using hydrophilic monomers and hydrophobic monomers, and hydrogels produced using hydrophilic monomers such as crosslinkable monomers and copolymerizable monomers.

[0055] The hydrophilic monomer is not particularly limited as long as it is a polymerizable compound having at least one hydrophilic group and a polymerizable group such as a (meth)acryloyl group or a vinyl group in the molecule. Examples include hydroxymethyl(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2,3-dihydroxypropyl(meth)acrylate, 2-polyethylene glycol(meth)acrylate, acrylamide, 2-polypropylene glycol(meth)acrylate, N,N-dimethylmethacrylamide, N-vinylpyrrolidone (NVP), N,N-dimethylacrylamide (DMAA), (meth)acrylic acid, polyethylene glycol mono(meth)acrylate, glyceryl(meth)acrylate (glycerol(meth)acrylate), N-vinyl-N-methylacetamide, N-vinyl-N-ethylacetamide, N-vinyl-N-ethylformamide, and N-vinylformamide. These may be used alone or in combination of two or more. From the viewpoint of safety, the hydrophilic monomer is preferably 2-hydroxyethyl (meth)acrylate, (meth)acrylic acid, N-vinylpyrrolidone, or N,N-dimethylacrylamide, which are commonly used as raw materials for contact lenses. In the present invention, the term "(meth)acrylate" is a general term for acrylate and methacrylate.

[0056] The content of the hydrophilic monomer is not particularly limited as long as it is an amount that allows the polymer obtained by copolymerizing the monomer components containing the hydrophilic monomer to form a hydrogel, but for example, it is preferably 50 wt% to 99.99 wt%, and more preferably 75 wt% to 99.90 wt%, relative to the total amount of the monomer components.

[0057] In order to form a network structure of the hydrogel and to adjust the mechanical strength, a crosslinking monomer may be included as a monomer component.

[0058] The crosslinking monomer is not particularly limited as long as it is a polymerizable compound having two or more polymerizable groups, such as (meth)acryloyl groups or vinyl groups, in the molecule, and examples thereof include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, di Examples of the crosslinkable monomer include (meth)acrylate crosslinkable monomers such as pentaerythritol hexa(meth)acrylate; and vinyl crosslinkable monomers such as allyl methacrylate, diallyl maleate, diallyl fumarate, diallyl succinate, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, diethylene glycol bisallyl carbonate, triallyl phosphate, triallyl trimellitate, diallyl ether, N,N-diallyl melamine, and divinylbenzene. These may be used alone or in combination of two or more. Among these, bifunctional crosslinkable monomers are preferred, and ethylene glycol di(meth)acrylate and triethylene glycol di(meth)acrylate, which are commonly used as raw materials for contact lenses, are more preferred.

[0059] The content of the crosslinking monomer may be appropriately set depending on the desired network structure formability and mechanical strength of the hydrogel, and is not particularly limited. For example, it is preferably 0.01 wt% to 3.0 wt% relative to the total amount of the monomer components. Since an excessive content tends to impair the flexibility of the hydrogel, it is more preferably 0.05 wt% to 1.5 wt%, and even more preferably 0.1 wt% to 0.5 wt%.

[0060] In order to impart desired optical properties and physicochemical properties to the hydrogel, silicone-based monomers, hydrophobic monomers, ultraviolet absorbers, and the like, which are commonly used as raw materials for contact lenses, may be used as monomer components.

[0061] The size of the hydrogel can be set appropriately according to the animal to be used, and is not particularly limited. For example, when used in a dog, the diameter is preferably 10 mm to 20 mm, and more preferably 12 mm to 18 mm; the base curve (BC) is preferably 7 mm to 12 mm, and more preferably 8 mm to 10 mm.

[0062] (Method of manufacturing contact lenses for animals) The method for producing the veterinary contact lens of one embodiment of the present invention is not particularly limited, and the lens can be produced by applying a method for producing contact lenses having a colored portion. For example, a contact lens having a colored portion can be obtained by applying a coloring component prepared according to a conventional method to a contact lens substrate, preferably the surface and / or interior of the contact lens substrate, by a commonly used method such as spin coating, spraying, dipping, or pad printing. When producing a contact lens having a colored portion on its surface, it is preferable to use pad printing, which is suitable for adjusting the printing position of the coloring component.

[0063] On the other hand, when the colored portion is disposed inside the veterinary contact lens to avoid contact with ocular tissue, it is preferable to manufacture the veterinary contact lens by combining pad printing with a cast molding method using male and female molds. Another aspect of the present invention is a method for manufacturing a veterinary contact lens using pad printing and cast molding.

[0064] A method for producing a contact lens for animals according to one embodiment of the present invention comprises the following steps: (1) a step of fitting a male mold into a female mold containing a contact lens-forming composition in its recess to obtain a molding die, and subjecting the resulting molding die to a copolymerization reaction to obtain a copolymer; (2) forming a first layer containing a first coloring component on the surface of the copolymer in the convex portion of the male mold separated from the female mold, and further forming a second layer containing a second coloring component on the first layer to obtain a copolymer having a colored portion including the first layer and the second layer thereon, wherein the first coloring component is different from the second coloring component; (3) a step of fitting a male mold having the copolymer with the colored portion in the convex portion into a female mold having a contact lens composition in the concave portion to obtain a molding die, and subjecting the resulting molding die to a copolymerization reaction to obtain a contact lens substrate for animals having a colored portion; and (4) A step of subjecting the animal contact lens substrate having the colored portion to a hydration swelling treatment to obtain an animal contact lens having a colored portion.

[0065] In step (1), a copolymer having a contact lens shape is obtained, to which a colorant is to be applied. In step (2), the surface of the copolymer (front curve surface; FC) is released, and a first coloring component is applied and dried on the surface to form a first layer. The surface opposite the front surface of the copolymer is the back surface (base curve surface; BC). A second coloring component is then applied and dried on the first layer to form a second layer. This results in a colored portion formed on the surface of the copolymer attached to the tips of the convex portions of the male mold, with the first layer and the second layer laminated on the first layer. In step (3), the male mold with the copolymer having colored portions attached to the tips of the convex portions is inserted into a female mold containing a monomer component in the concave portions, and the molding die consisting of the male and female molds is subjected to a copolymerization reaction to obtain a veterinary contact lens substrate having a colored portion. In step (4), the veterinary contact lens substrate having a colored portion is hydrated and swollen to obtain a veterinary contact lens having a colored portion therein, with colored components of two different colors laminated together.

[0066] In the manufacturing method of one embodiment of the present invention, various steps or operations can be added between or during steps, as long as an animal contact lens having a colored portion that can solve the problems of the present invention is obtained, but it is preferable that steps (1) to (4) are carried out continuously.

[0067] In step (1), a contact lens composition is placed between a male mold and a female mold, and the resulting mold is subjected to a copolymerization reaction to obtain a copolymer, in the same manner as in the conventional cast molding method for producing contact lenses. The contact lens composition contains monomer components, a polymerization initiator, and optionally other additives.

[0068] The method for preparing the composition for forming a contact lens is not particularly limited, but for example, the composition can be prepared by stirring and mixing, using a magnetic stirrer or the like, components that make up the contact lens, such as monomer components and a polymerization initiator, in amounts that are set so that the resulting copolymer has the desired physical properties.

[0069] The polymerization initiator may be appropriately selected depending on the properties of the monomers used, and is not particularly limited. Examples include peroxide-based polymerization initiators such as lauroyl peroxide, cumene hydroperoxide, and benzoyl peroxide, which are common radical polymerization initiators; and azo-based polymerization initiators such as azobisdimethylvaleronitrile and azobisisobutyronitrile. As the polymerization initiator, one of these may be used alone, or two or more may be used in combination. The amount of polymerization initiator added is not particularly limited as long as it is an amount that can achieve a copolymerization reaction of the monomers, and is, for example, preferably 10 ppm to 7,000 ppm relative to the total amount of the monomer components.

[0070] After the male mold is fitted into the female mold of the mold into which an appropriate amount of the contact lens-forming composition has been poured, the mold is subjected to a copolymerization reaction. The conditions for the copolymerization reaction can be appropriately set depending on the type of polymerization initiator used. For example, when a photopolymerization initiator is used as the polymerization initiator, the mold containing the contact lens-forming composition is irradiated with light at 20°C to 40°C. Alternatively, when a thermal polymerization initiator is used as the polymerization initiator, the mold containing the contact lens-forming composition is heated to between room temperature and approximately 100°C. The mold is left under these conditions for a time until the copolymerization reaction is completed, preferably several hours to 120 hours.

[0071] After the copolymerization reaction, the female mold and male mold are separated by a method commonly used in the manufacture of contact lenses using a molding die, yielding a copolymer in the shape of a contact lens attached to the convex surface of the male mold. In this case, the surface that was in contact with the concave surface of the female mold becomes the surface of the copolymer (FC surface).

[0072] In step (2), for example, a first coloring component is applied to a predetermined position on the surface of the copolymer obtained in step (1) by pad printing or the like, followed by thorough drying using a thermostatic dryer or the like to form a first layer containing the first coloring component on the surface of the copolymer. A second layer containing a second coloring component can also be formed on the first layer by a similar procedure. The amount of coloring component applied and drying conditions can be appropriately determined depending on the type and concentration of the colorant used as the coloring component. Through step (2), a copolymer having a multilayered colored portion on the surface is obtained, consisting of a first layer containing the first coloring component and a second layer containing the second coloring component thereon. The copolymer having the colored portion remains attached to the convex portion of the male mold. Each coloring component may be used as is, or a solution containing the coloring component may be prepared and used. The solution containing the coloring component is not particularly limited, and examples thereof include a solution prepared by dissolving the coloring component in a solvent capable of dissolving the coloring component, such as an organic solvent such as hexane, acetone, or isopropyl alcohol, so that the coloring component is present in a concentration of 1 wt% to 90 wt%, preferably 10 wt% to 50 wt%. The solution containing the coloring component may also contain other components, such as thickeners such as polyethylene glycol and polyvinylpyrrolidone, and monomer components that are constituents of contact lens substrates.

[0073] In step (3), the same operation as in step (1) is carried out. That is, the male mold having the copolymer having colored portions attached to the convex portions after step (4) is fitted into a female mold having the same or different recess size as that used in step (1) into which an appropriate amount of the same or different contact lens-forming composition as that used in step (1) has been poured, and the mold is then subjected to a copolymerization reaction under conditions appropriate for the type and amount of polymerization initiator, thereby obtaining a contact lens substrate having colored portions. It is preferable that the female mold used in step (3) has the same shape as the female mold used in step (1).

[0074] In step (4), the contact lens substrate having the colored portion formed in step (3) is released from the mold, cut and / or polished as necessary, and then hydrated and swollen to form a hydrogel. Examples of the liquid (swelling liquid) used include water, physiological saline, and isotonic buffer solution. The hydration swelling treatment is preferably carried out by immersing the contact lens substrate having the colored portion in a swelling liquid heated to 60°C to 100°C for a certain period of time, thereby causing the contact lens substrate having the colored portion to swell. Furthermore, the hydration swelling treatment preferably involves removing unpolymerized monomers contained in the contact lens substrate having the colored portion.

[0075] The hydrogel after hydration and swelling can contain about 10 wt% to about 80 wt% of the contact lens substrate (polymer). That is, the hydrogel substrate accounts for about 40 wt% to about 80 wt% of the hydrogel. The remainder of the hydrogel is typically formed from a liquid component (e.g., water) that hydrates the hydrogel substrate.

[0076] (Use of contact lenses for animals) The animals that can wear the veterinary contact lenses of one embodiment of the present invention are not particularly limited, and examples include mammals such as dogs, cats, horses, cows, pigs, sheep, and goats. However, humans are not included in the animals that can wear the veterinary contact lenses of one embodiment of the present invention. Therefore, the veterinary contact lenses of one embodiment of the present invention can be said to be contact lenses for non-humans.

[0077] The method for applying the veterinary contact lens of one embodiment of the present invention to an animal is not particularly limited, and either method may be used, such as application to the animal's eye by human hands or application to the animal's eye using a dedicated instrument.

[0078] The use of the veterinary contact lens of one embodiment of the present invention is not particularly limited, but it is preferably used, for example, as a contact lens for bandages to protect the cornea.

[0079] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples, and the present invention can take various forms as long as the object of the present invention can be solved. [Example]

[0080] [1. Preparation of coloring component] As the first coloring component, a 20 wt % titanium oxide solution was prepared by mixing 60 wt % of a hexane solution containing 20 wt % titanium oxide, 20 wt % polyethylene glycol (PEG), and 40 wt % 2-hydroxyethyl methacrylate (HEMA). As the second coloring component, a 20 wt% pigment solution was prepared by mixing 10 wt% each of Pigment Red 187 and Pigment Yellow 180 with 60 wt% of a hexane solution containing 20 wt% polyethylene glycol (PEG) and 40% 2-hydroxyethyl methacrylate (HEMA).

[0081] 2. Preparation of Composition for Forming Contact Lenses for Animals Azobisisobutyronitrile (AIBN) was added in an amount of 3,500 ppm (external) based on the total mass of these monomers to a beaker containing 95.0 wt% of 2-hydroxyethyl methacrylate (HEMA), 4.80 wt% of methacrylic acid (MAA), and 0.20 wt% of ethylene glycol dimethacrylate (EDMA). The contents of the beaker were stirred and mixed to prepare a composition for forming animal contact lenses.

[0082] 3. Production of Veterinary Contact Lenses of Example 1 A pair of molds consisting of a male mold and a female mold was prepared for forming a contact lens having a diameter of 14.50 mm and a base curve (BC) of 8.60 mm.

[0083] After the contact lens-forming composition was poured into the female mold of the casting mold, the male mold was fitted in. The resulting pair of casting molds was subjected to a copolymerization reaction by heating the mold over a period of 12 hours in the range of 30°C to 100°C. After the copolymerization reaction, the casting molds were returned to room temperature and the female mold was separated to obtain a male mold with contact lens substrate (1) attached to the tip of the convex portion.

[0084] A first coloring component was printed in a circular pattern on a contact lens substrate (1) attached to a male mold using pad printing. The printed male mold was left to stand for two hours in a thermostatic oven set at 50°C, yielding a male mold with a contact lens substrate (2) attached thereto, having a colored portion consisting of a first layer. Next, a second coloring component was printed in a circular pattern on the colored portion consisting of the first layer of the contact lens substrate (2) attached to the male mold using pad printing. The printed male mold was left to stand for two hours in a thermostatic oven set at 50°C, yielding a male mold with a contact lens substrate (3) attached thereto, having a colored portion consisting of a first layer and a second layer thereon. The colored portion had an outer diameter (maximum diameter) of 9.80 mm, a width of 1.05 mm, and an area of ​​116.00 mm. 2 It exhibited a circular shape.

[0085] Another contact lens-forming composition was poured into the female mold of the molding die, and then the male mold with the contact lens substrate (3) attached was fitted into it. The resulting pair of molding dies was subjected to a copolymerization reaction by heating the mixture over a period of 12 hours in the range of 30°C to 100°C. After the copolymerization reaction, the molding dies were returned to room temperature and the female mold was separated, yielding a male mold with the contact lens substrate (4) attached, which contained a colored portion with a first layer and a second layer thereon.

[0086] The male mold with the contact lens substrate (4) attached was subjected to a hydration swelling treatment by immersing it in an ethanol-containing saline solution at 70°C and a saline solution at 70°C for one hour each, and then the hydrogel released from the male mold was immersed in fresh saline solution and subjected to high-pressure steam sterilization at 121°C for 30 minutes, thereby obtaining the veterinary contact lens of Example 1. The veterinary contact lens of Example 1 contained a colored portion having a first layer and a second layer thereon.

[0087] 4. Manufacture of Veterinary Contact Lenses of Comparative Example 1 In the same manner as in [3] above, a male mold was obtained with a contact lens substrate (1) attached to the tip of the convex portion. A second coloring component was printed in a circular pattern on the contact lens substrate (1) attached to the male mold using pad printing. The male mold after printing was left to stand in a thermostatic oven set at 50°C for 2 hours, thereby obtaining a male mold with a contact lens substrate (5) attached that had a colored portion consisting of a second layer. The colored portion had an outer diameter (maximum diameter) of 9.80 mm, a width of 1.05 mm, and an area of ​​116.00 mm. 2 It exhibited a circular shape.

[0088] A veterinary contact lens of Comparative Example 1 was obtained in the same manner as in [3] above, except that a male mold having a contact lens substrate (5) attached thereto was used instead of the male mold having a contact lens substrate (3) attached thereto. The veterinary contact lens of Comparative Example 1 contained a colored portion consisting of a second layer.

[0089] 5. Manufacture of Veterinary Contact Lenses of Comparative Example 2 In the same manner as in [3] above, a male mold was obtained to which a contact lens substrate (2) having a colored portion made of a first layer was attached. The colored portion had an outer diameter (maximum diameter) of 9.80 mm, a width of 1.05 mm, and an area of ​​116.00 mm. 2 It exhibited a circular shape.

[0090] A veterinary contact lens of Comparative Example 2 was obtained in the same manner as in [3] above, except that a male mold having a contact lens substrate (2) attached thereto was used instead of the male mold having a contact lens substrate (3) attached thereto. The veterinary contact lens of Comparative Example 2 contained a colored portion consisting of a first layer.

[0091] [6. Evaluation Method] (1) Lightness index (L * 1) and color brightness (T1) The colored portion of the contact lens substrate (2) consisting of the first layer was photographed using a digital microscope (manufactured by Keyence Corporation), and then the histogram of the colored portion in the photographed image was analyzed using bitmap image editing application software, and the lightness index (L * 1) was calculated. Then, the obtained brightness index (L * 1) and the area of ​​the colored part S (mm 2 Similarly, the coloring lightness (T1) was calculated from the lightness index (L * 1) and color brightness (T1) were calculated.

[0092] (2) Front and back distinguishability The distinguishability of the front surface (the surface that contacts the concave portion of the female mold; FC) and back surface (the surface that contacts the convex portion of the male mold; BC) of the contact lens was evaluated by visually inspecting the contact lens placed on artificial eyes (1) to (8) with the front or back surface facing outward, according to the following criteria. The artificial eyes (1) to (8) used were commercially available artificial eyes for handcrafted stuffed animals (with irises of black, brown, green, mottled black, mottled light brown, mottled dark brown, light green, and blue, respectively). ○: Distinguishing possible based on the color of the colored part on the front and / or back side only ×: It was not possible to distinguish the color only from the colored portions on the front and back sides, but it was possible to distinguish it from the appearance shape.

[0093] (3) External visibility The visibility of the colored portion of the contact lens was evaluated by visually inspecting the colored portion of the contact lens placed on the artificial eye (1) to (8) with the surface facing outward, according to the following criteria. ○: The colored part was easily visible ×: The colored portion was not visible, or even if it was visible, it was difficult to see.

[0094] [7. Evaluation Results] Photographs of the veterinary contact lens of Example 1 taken against a black background are shown in FIGS. 2 to 4. The left side of FIG. 2 is a plan view of the front surface (FC), and the right side of FIG. 2 is a bottom view of the back surface (BC). The left image in FIG. 3 is a plan view of the colored portion on the front surface (FC) taken in an enlarged scale, and the right image in FIG. 3 is a bottom view of the colored portion on the back surface (BC). The upper image in Figure 4 is a photograph taken from the back to the front at different angles, and the lower image in Figure 4 is a photograph taken from the front to the front at different angles.

[0095] As these figures show, the animal contact lens of Example 1 has a first layer that is white due to titanium oxide used as the first colorant, and a second layer that is orange due to the orange pigment used as the second colorant, so the colored portion appears light orange from the front and white from the back, and it was found that the front and back of the contact lens can be seen by the appearance of the color of the colored portion.

[0096] Lightness index (L * The evaluation results of the coloring lightness (T1), front / back distinguishability, and external visibility are shown in Table 1, along with the lens shape and colored portion shape. Table 1 also shows the lightness difference between the upper and lower layers of the colored portion for the veterinary contact lens of Example 1. Furthermore, when evaluating the front / back distinguishability for the veterinary contact lenses of Example 1 and Comparative Example 1, photographs taken from above of the artificial eye and the contact lenses placed on the artificial eye with the front and back surfaces facing outward are shown in Figure 5.

[0097] As shown in Table 1 and Figure 5, the animal contact lens of Example 1 was able to distinguish between the front and back sides when placed on either artificial eye, but the animal contact lenses of Comparative Examples 1 and 2 were unable to distinguish between the front and back sides when placed on either artificial eye.

[0098] Since the front and back of the veterinary contact lens of Example 1 could be distinguished, the presence of the colored portion was naturally visible on all artificial eyes. However, the colored portion of the veterinary contact lenses of Comparative Examples 1 and 2 was difficult to see depending on the type of artificial eye. In particular, when the veterinary contact lenses of Comparative Examples 1 and 2 were placed on artificial eyes 2 and 5-6, which had brown irises, the colored portion of the veterinary contact lenses of Comparative Examples 1 and 2 was difficult to see.

[0099] From the above results, it was found that when the color of the colored portion formed using a single colorant is similar to the color of the iris, it is difficult to see the colored portion of the contact lens when worn on an animal's eye. In contrast, it was found that when a veterinary contact lens has a colored portion including a first layer and a second layer thereon, both of which have different colors, the contact lens when worn on an animal's eye can be seen by the colored portion, even if the color of the second layer is similar to the color of the iris.

[0100] [Table 1] [Industrial Applicability]

[0101] According to the present invention, highly safe contact lenses can be mass-produced on an industrial scale, allowing the presence or absence of contact lenses worn by animals and the distinction between the front and back to be easily visually confirmed from the outside, thereby contributing to the health and welfare of animals.

Claims

1. A veterinary contact lens having a tinted portion including a first layer and an overlying second layer, the first and second layer containing different first and second coloring components, respectively.

2. A contact lens for animals having a substantially annular colored portion, the first layer containing first and second colored components that are different from each other, and a second layer thereon.

3. The colored portion has an area of ​​50 mm ２ ~200mm ２ 3. The veterinary contact lens according to claim 1, wherein

4. The lightness index L of the first coloring component ＊ １ and the lightness index L of the second coloring component ＊ ２ The contact lens for animals according to claim 1 or 2, wherein the difference ΔL between the above and the above is +2 or more or −2 or less.

5. The coloring lightness T of the first coloring component １ and the coloring lightness T of the second coloring component ２ The animal contact lens according to claim 1 or 2, wherein the difference ΔT between the values ​​is +600 or more or −600 or less.

6. The veterinary contact lens according to claim 1 or 2, wherein the colored portion is provided on the surface or inside of the veterinary contact lens.

7. A method for producing a contact lens for animals, comprising the steps of: (1) A step of obtaining a copolymer by subjecting the resulting mold obtained by fitting a male mold into a female mold containing a contact lens-forming composition in its recess to a copolymerization reaction. (2) A step of forming a first layer containing a first coloring component on the surface of the copolymer in the convex portion of the male mold separated from the female mold, and further forming a second layer containing a second coloring component on the first layer to obtain a copolymer having a colored portion including the first layer and the second layer thereon, wherein the first coloring component is different from the second coloring component. (3) A step of fitting a male mold having the copolymer with a colored portion on the convex portion into a female mold having a contact lens composition in the concave portion to obtain a molding die, and subjecting the resulting molding die to a copolymerization reaction to obtain a contact lens substrate for animals having a colored portion. (4) A step of subjecting the animal contact lens substrate having the colored portion to a hydration swelling treatment to obtain an animal contact lens having the colored portion.

8. The method according to claim 7, wherein the veterinary contact lens is the veterinary contact lens according to claim 1 or 2.

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