TWI810043B - Dyeing method of functional contact lenses - Google Patents

Abstract

A dyeing method of functional contact lenses, including the following steps: providing a dry lens body, including hydrogel with 0-90% water content, silicone hydrogel with 0-90% water content, or a combination thereof. Preparing amphoteric polymethyl ether prepolymer and combine it with hydrophilic monomer to form a masking ring material. The masking ring material is attached to an inner surface of the dry lens body to form a masking ring layer. Dropping a colorant onto the inner surface, the masking ring layer surrounds the colorant. The colorant is heated and fixed after being irradiated with ultraviolet light to form a colored layer on the inner surface. Putting the dry lens body into water to hydrate, and removing the masking ring layer to obtain a wet lens body.

Description

Dyeing method of functional contact lens

The invention relates to a dyeing method for contact lenses, in particular to a precise dyeing method for functional contact lenses.

Contact lenses have been commercialized for 60 years since they were invented in early 1950. The initial contact lenses were made of hard materials (such as: PMMA (Poly(methyl methacrylate), polymethyl methacrylate)). Due to the hard material and the poor oxygen permeability and hydrophilicity of the contact lens, the wearable time of the contact lens is relatively short, and there will be obvious foreign body discomfort. The invention of soft contact lenses in the mid-1970s can be described as a progressive reform, which is made of a hydrogel material based on HEMA (2-Hydroxylethyl methacrylate, 2-hydroxyethyl methacrylate). Due to the high water absorption of this material, after hydration, it becomes soft and highly water-containing, which greatly improves the wearing comfort. However, its oxygen permeability is still low, and it can only be worn for 8 to 12 hours a day. Later, corneal hypoxic edema and neovascularization often occur. Taiwan is densely populated and the living space is relatively small. Coupled with the heavy pressure to go to school, the population with abnormal vision is increasing rapidly. Although vision abnormality can be corrected by wearing glasses, wearing glasses often causes inconvenience in daily life. Therefore, people often Vision correction with contact lenses. Contact lenses are worn directly on the cornea and near the edge of the eye or the sclera area to correct vision or as a device for corneal shaping; product development has gradually changed from the earliest hard materials such as glass and PMMA to hydrophilic ones. HEMA material, and the future development trend is towards the durable Silicon Hydrogel (Silicon Hydrogel) material.

With the rapid development of science and technology, especially electronic products such as LED lights, tablet computers, TVs, smart phones and other 3C products will emit blue light. When using 3C products, the eyes will look directly at the blue light emitted by the screen. Blue light is the most energy-intensive part of visible light that is closest to ultraviolet light. Its wavelength is between 380nm and 530nm. Its shorter wavelength will focus in front of the retina in advance, which is easy to cause scattering. Therefore, the eyes need to focus harder and cannot relax. Long-term Time tends to reduce the contrast and clarity of the eye's visual image and increase eye fatigue. Furthermore, when blue light enters the eyes, it will not be absorbed by the cornea and lens, but can penetrate the cornea and lens and directly enter the macula. If the eyes absorb too much blue light, symptoms such as tingling and photophobia will occur in the initial stage. In the long run, the macula will become inflamed and edematous, and a hidden knot may form in the center of the macula. Once the hidden knot ruptures and causes bleeding, it will cause central vision loss and cannot See things clearly. Therefore, with the change of modern life and the long-term exposure to blue light stimulation, macular degeneration, which was more common in the elderly in the past, tends to decline in age. Anti-blue light has become an important issue.

The anti-blue light contact lens commonly known in the market is like the anti-blue light and anti-UV contact lens disclosed in the Republic of China Patent No. M487455 "Colored Contact Lens with Blue Light Filter and Anti-UV Function", which consists of upper, middle and lower lenses. , and use the blue light filter coating agent in the upper lens to achieve the effect of reducing the blue light penetrating contact lenses and direct eyes. Among them, the blue light filter coating agent is currently not legally added to the US FDA safety approval scope of contact lenses, and will cause harm Eyes are worried, and there is no efficiency in mass production except time-consuming, labor-consuming and cost-consuming.

In the hot summer, the ultraviolet light of 380~390nm has a short wavelength and high energy. Prolonged exposure to the sun may cause macular degeneration, cataract, retinopathy, keratitis (light pollution) and other damage. Therefore, choosing a suitable pair of sports sunglasses has become one of the most important equipment for summer sports. The advantage of wearing sunglasses is that they can prevent excessive sunlight from irritating the eyes Eyes, filter ultraviolet and infrared rays, avoid damage to the optic nerve, and help to improve visual contrast sensitivity, reduce reflection glare, and increase color contrast. For patients with photophobia, "or dry eye syndrome, early cataracts, and corneal and conjunctival inflammation, wearing sunglasses can help improve. The Republic of China Patent No. I554803 discloses a method that simplifies the manufacturing process and consistently produces anti-blue light and anti-aging Ultraviolet anti-blue light contact lens preparation method. It is to adjust one or more dyes such as yellow, orange, red, and green according to the color of the dye and the addition ratio, or add a blue light absorber to the contact lens hydrogel or silicon hydrogel monomer Then carry out mold casting or rotary molding and other processes. After the dry film is solidified and formed, throw it into the hydration tank for color fixation and hydration extraction to complete the finished product of anti-blue light contact lenses. But this invention is not applicable to high Concentrated dyes, because this also blocks the UV-visible light initiation reaction (wavelength 380~400nm) and cannot be polymerized to form lenses.

Our company's previous invention (Republic of China Patent No. I697707) therefore proposes the following dyeing method and the prepared contact lens. Sports-specific contact lenses use a unique light filtering technology, which can block 90% of glare blue light and 95% of ultraviolet rays of different wavelengths. It can not only effectively reduce the glare of light, but also reduce the degree of visual distortion and highlight the movement The function of key objects (such as a fast-moving ball) allows people to get a clearer and brighter view from any angle when exercising. Compared with traditional frame-type sports goggles, wearing sports-specific contact lenses is not only more comfortable and convenient but also safer. People no longer have to worry about blurred vision due to sweating or eye damage caused by intense collisions during sports. accidental damage. Restore vision faster in bright sunlight than with clear lenses. In addition, subjects were able to achieve better visual recognition in bright sunlight compared to clear lenses. Lenses allow subjects to focus more quickly in bright and shaded conditions than clear lenses. It can be seen from the above that whether it is making anti-blue light or sports sun contact lenses, the proper selection of dyes/absorbers and the dyeing method are very important.

However, after wearing sports-specific contact lenses, the iris of the eye will be completely covered by the dark-colored lens that has been dyed, and the color of the eye will change and affect the appearance. The lens repels, but the real effect is only in the entire pupil range. Therefore, the present invention can produce accurate tinted lenses in the optical zone (pupil zone) by using the shielding ring design, and obtain a faster, more convenient and more stable dyeing process.

The invention provides a dyeing method for functional contact lenses, which can fix reactive dyes on the surface of the lens body, which helps to improve the color uniformity of the lens appearance without affecting the color of the iris when the user wears it. Moreover, the dyeing method of the functional contact lens of the present invention can precisely control the dyeing range, shape and thickness of the dyed layer.

The dyeing method of the functional contact lens provided by the present invention comprises the following steps: providing a dry sheet of the lens body, including a hydrogel with a water content of 0-90%, a siloxane silicone hydrogel with a water content of 0-90%, or its combination. The amphoteric polymethyl ether prepolymer is prepared and combined with a hydrophilic monomer to form a shielding ring material, and the shielding ring material is attached to the inner surface of the dry sheet of the lens body to form a shielding ring layer. The dyeing agent is dropped onto the inner surface, the masking ring layer surrounds the dyeing agent, and the dyeing agent is heated and fixed after being irradiated with ultraviolet light, so as to form a dyed layer on the inner surface. Put the dry film of the lens body in water to hydrate, remove the shielding ring layer, and obtain the wet film of the lens body.

In one embodiment of the present invention, the above method of attaching the shadow ring material to the inner surface of the lens body dry sheet to form the shadow ring layer includes pad printing and photopolymerization curing to adhere to the inner surface of the lens body dry sheet On the surface.

In an embodiment of the present invention, the above-mentioned method for staining the functional contact lens further includes the step of placing the lens body wet sheet in a buffer solution and sterilizing it.

In an embodiment of the present invention, the above-mentioned method for providing a dry sheet of the lens body includes performing a hydrogel with a water content of 0-90%, a silicone hydrogel with a water content of 0-90%, or a combination thereof. UV curing.

In one embodiment of the present invention, the composition of the above-mentioned shielding ring material includes: about 30-70 weight percent polymethyl ether prepolymer with a molecular weight of about 7,000-20,000; about 30-70 weight percent hydrophilic monomer body hydrogel; and 0.1-2 weight percent ultraviolet light initiator.

In one embodiment of the present invention, the above-mentioned dyeing agent includes: 0.01-5 weight percent of one or more dyes; about 30-45 weight percent of polymethyl ether prepolymer, molecular weight is about 7,000~20,000; 1- 5% by weight of one or more alkaline solutions; and 0.1-2% by weight of an ultraviolet light initiator.

In one embodiment of the present invention, the above-mentioned dyeing agent is irradiated with ultraviolet light and then heated and fixed to form a dyed layer on the inner surface, which includes heating at 60-70° C. and continuing to fix the color for 20-60 minutes.

In an embodiment of the present invention, the method for hydrating the dry lens body in water includes immersing the dry lens body in an aqueous solution at 60-90° C. for 30-60 minutes.

In an embodiment of the present invention, there is no cross-linking reaction between the above-mentioned shielding ring layer and the dry sheet of the lens body.

In an embodiment of the present invention, the area corresponding to the inner surface of the above-mentioned shielding ring layer is a part of the area corresponding to the iris of the user's eye, and the dyed layer corresponds to the optical zone of the pupil of the user's eye.

In the dyeing method of the functional contact lens according to the embodiment of the present invention, the shadow ring layer is formed by attaching the shadow ring material to the inner surface of the dry sheet of the lens body. Then the dyeing agent is dropped onto the inner surface, the masking ring layer surrounds the dyeing agent, and the dyeing agent is heated and fixed to form a dyed layer. Finally, put the dry film of the lens body in water to hydrate and remove the masking ring layer. Through the masking ring layer, the dyeing range, shape and thickness of the dyed layer can be precisely controlled, which helps to improve the color uniformity of the lens appearance without affecting the use The color of the iris when the wearer wears it.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

S101, S102, S103, S104, S105: steps

FIG. 1 is a schematic flow chart of a dyeing method of a functional contact lens according to an embodiment of the present invention.

2A and 2B are schematic diagrams of finished functional contact lenses according to an embodiment of the present invention.

FIG. 1 is a schematic flow chart of a dyeing method of a functional contact lens according to an embodiment of the present invention. Please refer to FIG. 1 , the dyeing method of the functional contact lens of the present embodiment includes the following steps. Step S101: Provide a dry sheet of the lens body, including hydrogel with a water content of 0-90%, silicone hydrogel with a water content of 0-90%, or a combination thereof. Step S102: Prepare an amphoteric polymethyl ether prepolymer and combine it with a hydrophilic monomer to form a shielding ring material, and attach the shielding ring material to the inner surface of the dry sheet of the lens body to form a shielding ring layer. Step S103: drop the dyeing agent onto the inner surface, the masking ring layer surrounds the dyeing agent, the dyeing agent is heated and fixed after being irradiated with ultraviolet light, so as to form a dyed layer on the inner surface. Step S104: Hydrate the dry film of the lens body in water, remove the shielding ring layer, and obtain the wet film of the lens body. Optionally, step S105 can be performed again: placing the lens body wet sheet in the buffer solution and sterilizing.

material preparation

Synthesis of polysiloxane prepolymer

This example provides a method for preparing an amphoteric silicon-containing prepolymer, which is obtained by reacting isocyanic acid with polydimethylsiloxane compound as a raw material, and then capping with a hydroxyl monomer, which includes There are the following steps: isocyanic acid reaction: system with bishydroxy polydimethylsiloxane compound and isocyanate The cyanic acid compound is used as the raw material, and the diluent is added to react in a medium temperature environment to obtain the first product; the first product is added to a hydrophilic chain extender (chain extender), and the terminal hydroxylation reaction is carried out in sequence, and then extended. Chain reaction to obtain the second product: continue to react the second product and the acrylate compound at room temperature for at least 12 hours to obtain the amphoteric silicon-containing prepolymer as the third product. Among them, the hydrophilic chain extenders are mainly polyol series, which include ethylene glycol, propylene glycol, 1,4-butanediol, polyethylene glycol, polypropylene glycol, polypropylene glycol diglycidyl ether, and the like.

Its detailed example is as follows: take 50g of dimethyl polysiloxane containing double-terminal hydroxyl groups (trade name KF-6001, purchased from Zixinyue Chemical Industry Co., Ltd.), add 10g of isofluorine under nitrogen at room temperature ketone diisocyanate and 0.02g dibutyltin dilaurate, after reacting for 12 hours, add 30g polyethylene glycol (weight average molecular weight is 600), 100g tetrahydrofuran and 0.02g dibutyltin dilaurate, react for 24 hours again, with Infrared absorption spectrum confirms that the -NCO characteristic peak at around 2250 cm-1 disappears and the reaction is completed. Add 10g of isophorone diisocyanate and 0.02g of dibutyltin dilaurate at room temperature under nitrogen again, and after 24 hours of reaction, add 12g of 2-methyl-2-acrylic acid-2,3-dihydroxypropyl Esters, 0.02g of dibutyltin dilaurate, reacted at 60°C for 24 hours, confirmed by infrared absorption spectrum that the -NCO characteristic peak at around 2250cm-1 disappeared and the reaction was completed, and polysiloxane with dimethylpolysiloxane as the main structure was obtained. The oxane prepolymer has a weight average molecular weight of 11,000~13,000 (identified by GPC).

Polymethyl ether prepolymer synthesis

This example provides a method for preparing an amphoteric polymethyl ether prepolymer, which uses polytetramethylene ether glycol PTMEG 1000 (Polytetramethylene Ether Glycol) as a raw material for isocyanic acid reaction, and then reacts with hydroxyl mono It is obtained after the body is blocked, which includes the following steps: Isocyanic acid reaction: it uses bishydroxy polydimethylsiloxane compound and isocyanic acid compound as raw materials, and then adds a diluent to carry out the reaction in a medium temperature environment , to obtain the first product; the first product is added to a hydrophilic chain extender (chain extender), followed by terminal hydroxylation reaction, and then chain extension reaction to obtain Obtaining the second product: continue to react the second product and the acrylate compound at room temperature for at least 12 hours to obtain the amphoteric polymethyl ether prepolymer as the third product. Among them, the hydrophilic chain extenders are mainly polyol series, which include ethylene glycol, propylene glycol, 1,4-butanediol, polyethylene glycol, polypropylene glycol, polypropylene glycol diglycidyl ether, and the like.

The detailed examples are as follows: Take 50g of polytetramethylene ether glycol PTMEG 1000 (Polytetramethylene Ether Glycol) as raw material, add 10g of isophorone diisocyanate and 0.02g of dilauric acid diisocyanate under nitrogen at room temperature Butyltin, after reacting for 24 hours, add 30g of polyethylene glycol (weight average molecular weight: 600), 100g of tetrahydrofuran and 0.02g of dibutyltin dilaurate, react for another 24 hours, and confirm the -NCO of about 2250cm-1 by infrared absorption spectrum The reaction is complete when the characteristic peaks disappear. Add 10g of isophorone diisocyanate and 0.02g of dibutyltin dilaurate at room temperature under nitrogen again, and after 24 hours of reaction, add 12g of 2-methyl-2-acrylic acid-2,3-dihydroxypropyl Esters, 0.02g dibutyltin dilaurate, reacted at 60°C for 24 hours, confirmed by infrared absorption spectrum that the -NCO characteristic peak at about 2250cm-1 disappeared and the reaction was completed, and polymethyl ether prepolymer was obtained. The weight average molecular weight was about 7,000~20,000 (identified by GPC).

In this embodiment, the hydrophilic monomer can be, for example, 2-hydroxyethyl methacrylate (2-hydroxyethyl methacrylate, HEMA); N, N-dimethyl acrylamide (N, N-dimethyl acrylamide, DMA ), N,N-diethyl acrylamide (N,N-diethyl acrylamide, DEA), N-vinyl pyrrolidone (N-vinyl pyrrolidone, NVP), glycerol methacrylate (GMA), molecular weight 400 polyethylene glycol methacrylate mono methyl ether (polyethylene glycol methacrylate mono methyl ether) or a combination thereof, but not limited thereto.

In this embodiment, the ultraviolet light initiator is beneficial to UV light curing, and the content of the ultraviolet light initiator may be 0.1 weight percent to 2 weight percent. The UV initiator can be but not limited to the trade name Ciba®IRGACURE®1173, referred to as I-1173, and the trade name Ciba®IRGACURE®819, referred to as I-819. In addition, the UV initiator can be used alone or together When using two or more (including two). The aforementioned hydrophilic copolymer composition may optionally further include other additives to meet actual needs, and the additives that may be used include but are not limited to anti-UV absorbers and leveling agents.

According to an embodiment of the present invention, the above-mentioned derivatized silicon-containing monomer comprises polysiloxane prepolymer in an amount of 30-80% by weight, and the repeating unit of the hydrophilic monomer is in an amount of 10-50% by weight. Percentage, UV-blocking monomer is a monomer with benzotriazole (benzotriazole). According to an embodiment of the present invention, the UV-blocking monomer accounts for 0.1-1.5% by weight of the total weight of the silicone hydrogel composition; in addition, the UV-light initiator accounts for 0.1-2% by weight of the overall weight.

First add polysiloxane prepolymer and stir for about 0.5 hours to 1.5 hours, then add hydrophilic monomer/initiator and UV-blocking monomer together and continue stirring for about 0.5 hours to 1.5 hours, then it can become the present invention Silicone hydrogel composition. An aspect of the present invention provides a method for manufacturing the aforementioned silicone hydrogel lens. Inject the silicone hydrogel composition of any of the above-mentioned embodiments or examples into the mold for preparing the lens; perform ultraviolet curing on the silicone hydrogel composition in the mold for 30 to 60 minutes to allow it to undergo a cross-linking and curing reaction to Silicone hydrogel lenses are formed.

Hydrogel material preparation can be added together with hydrophilic monomers/initiators and UV-blocking monomers and continue to stir for about 0.5 to 1.5 hours, wherein the repeating units of hydrophilic monomers account for 95 to 99 weight percent , the UV-blocking monomer is a monomer with benzotriazole (benzotriazole). According to an embodiment of the present invention, the UV-blocking monomer accounts for 0.1-1.5% by weight of the total weight of the silicone hydrogel composition; in addition, the UV-light initiator accounts for 0.1-2% by weight of the overall weight. It can become the hydrogel composition of the present invention.

Hydrogel Lens Body Dry Sheet Preparation

One aspect of the present invention provides a method for manufacturing the above-mentioned hydrogel lens. Inject the hydrogel of any of the above-mentioned embodiments into the mold for preparing the lens; perform UV curing on the hydrogel composition in the mold for 30-60 minutes to allow it to undergo a cross-linking and curing reaction to form the lens body Dry flakes. Hydrogel or so-called hydrogel can include any conventional hydrogel ingredients such as: hydroxyethyl methacrylate (HEMA), hydroxypropyl methacrylate (Hydroxy propyl methacrylate (HPMA)), methyl methacrylate ( Acrylic monomer) (Methyl methacrylate, MMA), glyceryl methacrylate (Glyceryl methacrylate, GMA), N-vinyl pyrrolidone (N-vinyl pyrrolidone, NVP), N,N'-dimethylaniline (N,N'-dimethylacrylamide, DMA), N,N'-diethylacrylamide (N,N'-diethylacrylamide), N-isopropylacrylamide (N-isopropylacrlamide), 2-hydroxyethylacrylic acid ( 2-hydroxyethyl acrylate), vinyl acetate (vinyl acetate), N-acryloyl morpholine (N-acryloymorpholine), 2-dimethylaminoethyl acrylate (2-dimethylaminoethyl acrylate), or a combination thereof, but This is not the limit.

Shading ring material and application

The shadowing ring layer of this embodiment includes a specially designed shadowing ring material used to attach a specially designed shadowing ring material to the inner surface of the lens body dry sheet by pad printing. Wait for the subsequent dyeing process. Specifically, the area corresponding to the shielding ring layer on the inner surface is a part of the area corresponding to the iris of the user's eye, and the dyeing layer is a hollow area arranged in the middle of the inner surface, which corresponds to the user's eye. The optical zone of the pupil. Wherein the shadow ring material comprises about 30-70 weight percent of a polymethyl ether prepolymer with a molecular weight of about 7,000-20,000, about 30-70 weight percent of a hydrophilic monomer hydrogel lens material, and 0.1-2 weight percent % UV initiator, thus forming the shadow ring material composition.

Shading ring material and usage process

In this embodiment, a preferred method for preparing colored lenses is by pad-printing as shown below. There is first provided a metal plate, preferably made of steel or more preferably stainless steel, covered with a photoresist material which, once cured, becomes insoluble in water. Select or design the pattern and inner and outer diameters of the shadow ring, then use any of a number of techniques such as photography) to reduce it to the desired size, place it on a metal plate, and cure the photoresist. Conditions for pattern etching are known to those of ordinary skill in the art to which the present invention pertains. After patterning, the metal plate is next washed with an aqueous solution and the resulting image is etched into the metal plate to a suitable depth, such as about 10-20 microns, with an inner diameter of 4-8mm and an outer diameter of 6-14mm , so the width of the shielding ring is about 2-10mm.

The process first deposits the masking ring material on the filling depression on the pattern, then scrapes off the excess material with a scraper, and then extrudes it with a silicone head with a suitable geometry and variable hardness (generally about 10 Shore A durometer units) The masking ring material of the image on the metal plate is then squeezed and transferred to the inner surface of the lens body dry sheet. The printed masking ring is polymerized and formed by ultraviolet light, and is completely cured and attached to the lens body dry sheet of the inner surface. It should be understood that although the shielding ring layer is attached to the inner surface of the lens body dry sheet, there is no cross-linking reaction between the shielding ring layer and the lens body dry sheet. Therefore, the shadow ring layer can be removed by other subsequent treatments, and the final lens body product, for example, will not have the shadow ring layer.

Dye materials and their application

In this embodiment, the staining agent includes one or more dyes, one or more alkaline solutions. The dyes are, for example, organic dyes, including reactive dyes, phthalene blue dyes, phthalene green dyes, zozoviolet, vate orange#1, etc., and combinations thereof, but not limited thereto. Specifically, the dyeing agent includes 0.01-5 weight percent of one or more dyes, about 30-45 weight percent of polymethyl ether prepolymer, molecular weight of about 7,000-20,000, and 1-5 weight percent of one or more alkalis neutral solution, and 0.1-2 weight percent of the ultraviolet light initiator. The alkaline solution can be any alkaline compound such as NaOH, KOH, NaCO ₃ , NaHCO ₃ , Triethylamine (TEA) or Ethanolamine (ETA) and the like. Drop the dyeing agent onto the inner surface of the lens body dry sheet, and drop it into the inner diameter of the shielding ring layer, first undergo ultraviolet light polymerization for 1-10 minutes to make the dyeing agent form a gel state, and then heat it at 60-70°C The heating continues to fix the color for 20-60 minutes. Reactive dyes are azo-reactive dyes, which are non-toxic, meet the requirements for contact lens preparation, and have passed the regulations of the US Food and Drug Administration (FDA), such as Reactive Blue 21, Reactive Blue No 19, Reactive Yellow 15, Reactive Orange 78, Reactive Black 5 , CIReactive Yellow 86, CIReactive Red 11, CIReactive Red 180, CIReactive Blue163, etc., but not limited thereto. Reactive dyes are also water-soluble dyes with active groups in the molecular structure, which can form covalent bonds or hydrogen bonds with hydroxyl, amino, and carboxyl hydroxyl groups on contact lens materials. In the case of vinylidene reactive dyes, the active group contained is vinylsulfate (D-SO ₂ CH=CH ₂ ) or β-hydroxyethylsulfate. When dyeing, β-hydroxyethylsulfate undergoes elimination reaction in alkaline medium to form vinyl group, and then reacts with polymer hydroxyl or amino group through nucleophilic addition reaction to form covalent bond. The solution composed of reactive dyes may contain one or more reactive dyes.

Hydrate the above dyed lens body dry sheet in water, the water used is preferably RO water. Specifically, after soaking in an aqueous solution at 60-90°C for 30-60 minutes, the dry sheet can completely absorb water and swell, and remove hydrogel or dye residues that have not undergone cross-linking and curing reactions. At this time, since the shielding ring layer is only attached to the surface, there is no cross-linking reaction between the shielding ring layer and the lens body dry sheet, and they will be removed together. In this way, a stable and functional invisible dyeing concentrated in the optical area can be obtained. Glasses wet film. Finally, optionally, the above-mentioned functional contact lens wet sheet is placed in a buffer solution of phosphoric acid or boric acid saline with a pH value of 7.1-7.5 for high temperature and high pressure sterilization.

Reactive dyes can form covalent bonds with the hydroxyl group, amino group, and carboxyhydroxyl group of the lens body to be fixed on the lens body. The way of dyeing after alkali also helps to improve the fixation rate of reactive dyes and reduce the release of reactive dyes. Reactive dyes bonded to lenses absorb light in specific wavelength ranges. Preferably, the specific wavelength range is in the blue light wavelength range, so when visible light enters the tinted lens, the light with the specific wavelength is absorbed and blocked by the lens, reducing the amount of light passing through the lens.

It should be noted that although the reactive dye enters the lens body from the lens surface, the part of the lens body where the reactive dye is fixed is mainly the surface part. Reactive dyes preferably do not penetrate into the lens The interior of the body. Depending on the extent to which the reactive dye enters the lens body, the dyed layer can have different thicknesses. The degree of reactive dyes entering the lens body and the thickness of the dyed layer can be adjusted through the concentration of ionic salt solution, osmotic pressure, reactive dye concentration, and alkali concentration. The thickness of the dyed layer can be determined based on the type of reactive dye and the light absorption effect to be achieved.

2A and 2B are schematic diagrams of finished functional contact lenses according to an embodiment of the present invention. Please refer to FIG. 2A and FIG. 2B , where the schematic diagrams are photos taken under an optical microscope at a magnification of 20X. The colored area is the area of the dyed layer, and this area also corresponds to the optical zone of the pupil of the user's eye. It can be seen from Fig. 2A and Fig. 2B that the outline between the edge of the dyed layer and the inner surface of the dry sheet of the lens body is clear, and there will be no blurring of the edge. This is because the functional contact lens of the embodiment of the present invention In the dyeing method of the present invention, the shadow ring layer (not shown) is formed by attaching the shadow ring material to the inner surface of the lens body dry sheet. Then the dyeing agent is dropped onto the inner surface, the masking ring layer surrounds the dyeing agent, and the dyeing agent is heated and fixed to form a dyed layer. Finally, put the dry film of the lens body in water to hydrate and remove the masking ring layer. By using the masking ring layer, the area size of the dyed layer can be precisely controlled (the dyed layer in Figure 2A is smaller, and the dyed layer in Figure 2B is larger), shape , color and the thickness of the dyed layer, etc., help to improve the color uniformity of the appearance of the lens without affecting the color of the iris when the user wears it.

In addition, compared with the dyeing method in the conventional technology, it is generally difficult to precisely control the area size of the dyed layer when dyeing under the wet film, and it is easy to dye the entire lens body. However, under-dyeing of dry film requires the cooperation of molds. When you want to adjust the size, shape, color or thickness of the dyed layer area, you must replace a new mold or holder to achieve the desired effect, which costs a lot of money. Too high to be mass-produced. However, the functional contact lenses produced by the dyeing method of functional contact lenses according to the embodiment of the present invention can precisely control the area size, shape, color and thickness of the dyed layer by simply adjusting the shielding ring layer. , not only the production process is simple and the cost is saved, but also it can be mass-produced.

Although the present invention has been disclosed above with the embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field of the present invention can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the scope of the appended patent application.

S101, S102, S103, S104, S105: steps

Claims (10)

A method for dyeing functional contact lenses, comprising: providing a lens body dry sheet, including hydrogel with a water content of 0-90%, silicone hydrogel with a water content of 0-90%, or a combination thereof; An amphoteric polymethyl ether prepolymer and a hydrophilic monomer are combined to form a shielding ring material, and the shielding ring material is attached to an inner surface of the dry sheet of the lens body to form a shielding ring layer; a Dyeing agent is dropped onto the inner surface, the shielding ring layer surrounds the dyeing agent, and the dyeing agent is heated and fixed after being irradiated with ultraviolet light to form a dyed layer on the inner surface; and the lens body is dried Hydrate in water, remove the shielding ring layer, and obtain a wet film of the lens body. The dyeing method of functional contact lenses as described in Claim 1, wherein the method of attaching the shadow ring material to the inner surface of the lens body dry sheet to form the shadow ring layer includes pad printing and photopolymerization Curing adheres to the inner surface of the lens body dry sheet. The method for dyeing a functional contact lens as described in Claim 1 further includes the step of putting the wet film of the lens body in a buffer solution and sterilizing it. The method for dyeing a functional contact lens as described in Claim 1, wherein the method for providing the dry sheet of the lens body includes adding hydrogel with a water content of 0-90%, siloxane silicone water with a water content of 0-90% Gels or combinations thereof are cured with UV light. The dyeing method of functional contact lenses as described in Claim 1, wherein the composition of the masking ring material includes: about 30-70 weight percent polymethyl ether prepolymer, molecular weight is about 7,000~20,000; about 30-70 Hydrophilic monomer hydrogel in weight percent; and ultraviolet light initiator in 0.1-2 weight percent. The dyeing method of functional contact lenses as described in Claim 1, wherein the dyeing agent includes: 0.01-5 weight percent of one or more dyes; about 30-45 weight percent polymethyl ether prepolymer, molecular weight of about 7,000~20,000; 1-5% by weight of one or more alkaline solutions; and 0.1-2% by weight of an ultraviolet initiator. The dyeing method of functional contact lenses as described in claim 1, wherein the dyeing agent is heated and fixed after being irradiated with the ultraviolet light, and the method of forming the dyed layer on the inner surface includes heating at 60-70°C And continue to fix the color for 20-60 minutes. The method for dyeing functional contact lenses according to claim 1, wherein the method of hydrating the dry lens body in water comprises soaking the dry lens body in an aqueous solution at 60-90°C for 30-60 minutes. The method for dyeing functional contact lenses according to claim 1, wherein no cross-linking reaction occurs between the shielding ring layer and the dry sheet of the lens body. The dyeing method of functional contact lenses as described in claim 1, wherein the area corresponding to the inner surface of the shielding ring layer is a part of the area corresponding to the iris of a user's eye, and the dyed layer corresponds to the use The optical zone of the pupil of the eye.