A liquid sac-shaped contact lens and a manufacturing method thereof

Abstract

The present invention discloses a liquid sac-shaped corneal contact lens and a preparation method thereof. The liquid sac-shaped corneal contact lens is composed of a transparent film and a transparent oxygen-permeable liquid, and the oxygen-permeable liquid is wrapped inside the film; the film includes an inner elastomer layer and an outer hydrophilic polymer hydrogel layer. The liquid sac-shaped corneal contact lens of the present invention has the characteristic of being able to change its shape, can remain in a narrow pipeline in the form of a liquid drop, can be directly dropped into the eye from the pipeline, spread out on the corneal surface, is convenient to carry and has a simple wearing method.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogel contact lenses, and particularly to a corneal contact lens in the form of a liquid sac and a manufacturing method thereof. Background Art

[0002] Corneal contact lenses, commonly known as contact lenses, are lenses worn on the cornea of the eye to correct vision or protect the eyes.

[0003] Corneal contact lenses achieve functions such as vision correction for wearers by wearing an optical lens system on the corneal surface, and have advantages such as aesthetics and portability. Commonly used corneal contact lens materials include rigid oxygen-permeable materials, hydrogel materials, and silicone hydrogel materials, etc. Starting from traditional rigid corneal contact lenses, hydrogel materials have continuously evolved towards softer materials, among which hydrogel materials and silicone hydrogel materials are soft materials that can provide higher safety and comfort. Further, changing the corneal contact lens into a more flexible droplet form can not only improve the overall wearing comfort but also facilitate the formation of a drop-in wearing method for corneal contact lenses.

[0004] The processing and manufacturing methods of corneal contact lenses vary according to different types of corneal contact lenses. For example, rigid corneal contact lenses can be directly obtained by cutting and grinding with a precision machine tool. Soft corneal contact lenses can also be obtained by the mold method.

[0005] For example, the Chinese patent document with the application number CN202110768129.7 discloses a preparation method for a full-color contact lens, including the following steps: Step 1: Stir the color-changing raw material and the contact lens raw material to form a mixed solution, and then print the mixed solution on the iris area of the contact lens mold; Step 2: Then, through a UV light irradiation process or a heating process, the mixture used to form the contact lens reacts to form the contact lens, and then hydration is carried out; Step 3: The contact lens is successively immersed in alcohol, water, and finally in a buffer solution for equilibration.

[0006] The Chinese patent document with the application number 201821055491.X discloses a soft contact lens mold structure, including a front metal mold core and a rear metal mold core; the front metal mold core and the rear metal mold core cooperate with each other for injection molding to form a plastic mold body. The upper surface of the front metal mold core is a convex arc body, the upper surface of the rear metal mold core is provided with a concave arc body, and a circular groove is provided on the rear metal mold core.

[0007] Existing corneal contact lenses are often used by directly putting them into the eyes by users, which has certain inconvenience in portability; on the other hand, existing preparation methods cannot prepare and obtain a softer corneal contact lens that can exist in the form of a liquid sac. Summary of the Invention

[0008] The present invention provides a liquid - sac - shaped contact lens and a preparation method thereof. The liquid - sac - shaped contact lens is softer, has the characteristic of being able to change its shape, and is more portable.

[0009] The technical solution of the present invention is as follows:

[0010] A liquid - sac - shaped contact lens is composed of a transparent film and a transparent oxygen - permeable liquid, and the oxygen - permeable liquid is wrapped inside the film;

[0011] The film includes an inner elastomer layer and an outer hydrophilic polymer hydrogel layer.

[0012] The inner layer refers to the layer of the film closer to the internal oxygen - permeable liquid, and the outer layer refers to the layer closer to the cornea during use. The hydrogel layer has corneal affinity. Corneal affinity means that when the contact lens contacts the cornea: (1) the surface is softer, and the mechanical properties are compatible with the ocular surface; (2) the surface is more hydrophilic, which can effectively reduce the adhesion of grease and protein; (3) it has lower cytotoxicity and foreign body property, reducing the foreign body sensation on the ocular surface; (4) it has a lower friction coefficient and is smoother on the corneal surface.

[0013] The liquid - sac - shaped contact lens of the present invention has the characteristic of being able to change its shape, and can be retained in a narrow pipeline in the form of a liquid drop; it can be directly dropped into the eye from the pipeline and spread out on the corneal surface. According to the shape of the corneal surface and the designed volume of the contact lens, a contact lens with a specific diopter is formed to achieve vision correction.

[0014] Preferably, the elastomer layer is silicone rubber or silicone hydrogel; the hydrogel layer is at least one of polyacrylamide, poly (2 - hydroxyethyl methacrylate), and polyvinyl alcohol; the oxygen - permeable liquid is at least one of polydimethylsiloxane mother liquor, ethylene glycol, and glycerol.

[0015] Preferably, the thickness of the elastomer layer is 5 - 20μm, and the thickness of the hydrophilic polymer hydrogel layer is 0.5 - 10μm.

[0016] The present invention also provides a preparation method of a liquid - sac - shaped contact lens, including the following steps:

[0017] (1) Prepare a film with an elastomer layer and a hydrophilic polymer hydrogel layer;

[0018] (2) Perform surface activation treatment on the surfaces of the elastomer layers of two films respectively. Oppose the elastomer layers of the two films, inject a specific volume of oxygen - permeable liquid between the elastomer layers of the two films, and then assemble and bond the two films to enclose the oxygen - permeable liquid between the two films;

[0019] (3) Cut the film along the bonding edge to obtain the liquid sac-shaped corneal contact lens as described above;

[0020] According to the shape, size of the corneal surface and the required diopter, design the size of the liquid sac-shaped corneal contact lens and the injection volume of the oxygen-permeable liquid.

[0021] In the liquid sac-shaped corneal contact lens of the present invention, the elastomer layer ensures that the internal oxygen-permeable liquid does not permeate, and the hydrogel coating on the surface of the elastomer layer ensures good biocompatibility of the corneal contact lens and can be sufficiently lubricated with the ocular surface. Due to the use of a highly oxygen-permeable liquid and a highly biocompatible hydrogel film coating, the entire corneal contact lens can simultaneously have an ultra-high oxygen permeability rate, a super-biocompatible and super-lubricated surface.

[0022] Preferably, step (1) includes:

[0023] (1-1) Coat a sacrificial layer on the substrate, coat a prepolymer solution of the elastomer layer on the sacrificial layer, and cure to form the elastomer layer;

[0024] (1-2) Activate the surface of the elastomer layer to form active groups on its surface; then immerse it in a surface treatment preset solution, rinse and air-dry; then immerse it in a hydrogel prepolymer solution and cure to form a hydrophilic polymer hydrogel layer on the surface of the elastomer layer;

[0025] (1-3) Remove the sacrificial layer to obtain the film as described above.

[0026] Preferably, the sacrificial layer is a polyvinyl alcohol film.

[0027] Furthermore, in step (1-2), a polyvinyl alcohol aqueous solution is coated on the substrate, and the water is evaporated by heating to form a polyvinyl alcohol sacrificial layer film.

[0028] The mass concentration of the polyvinyl alcohol aqueous solution is 3-10%.

[0029] Furthermore, in step (1-3), the sacrificial layer is removed by hot water immersion.

[0030] The sacrificial layer can also be a photoresist.

[0031] More preferably, in step (1-2), the surface of the elastomer layer is rinsed with plasma for 2-5 minutes to form active groups on its surface.

[0032] The surface treatment preset solution is an ethanol solution of benzophenone, and the mass fraction of benzophenone is 5-20%.

[0033] The hydrogel prepolymer solution is an aqueous solution of a hydrophilic hydrogel polymer monomer and a photoinitiator, containing 10-30% by mass of the hydrophilic hydrogel polymer monomer and 1-20% by volume of the photoinitiator solution; the concentration of the photoinitiator in the photoinitiator solution is 0.1 mol / L.

[0034] Further preferably, the hydrophilic hydrogel polymer monomer is at least one of acrylamide, hydroxyethyl methacrylate and vinyl alcohol; the photoinitiator is at least one of α-ketoglutaric acid, I2959 and PI184.

[0035] Preferably, in step (1-2), ultraviolet light is used to photocure the hydrogel prepolymer solution, and the curing time is 15-30 min.

[0036] Preferably, step (2) includes:

[0037] (2-1) Use two hard bottom plates with round holes to hold up one of the films respectively, and make the hydrogel layer close to the hard bottom plate; the size of the round hole is the size of the liquid sac-shaped contact lens.

[0038] (2-2) Activate the surface of the elastomer layer of the film held up by the hard bottom plate, then drop a specific volume of oxygen-permeable liquid onto the surface of one of the films at the round hole, and then cover the other film on the oxygen-permeable liquid, align the two films at the round hole and assemble them, and enclose the oxygen-permeable liquid between the two films.

[0039] (2-3) Let the assembled films stand at 60-70 °C for 18-30 h to bond the two films, take them out and cut the films along the bonding edge to obtain the liquid sac-shaped contact lens.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] The present invention prepares a liquid sac-shaped contact lens by sandwiching a highly oxygen-permeable liquid between two films through a double-layer film sandwich method; the two side films adopt a composite double-layer form. While ensuring that the internal highly oxygen-permeable liquid does not penetrate through the elastomer, a hydrogel coating is formed on the surface of the elastomer to ensure good biocompatibility of the contact lens and sufficient lubrication with the ocular surface, so as to unfold on the ocular surface; due to the use of a highly oxygen-permeable liquid and a highly biocompatible hydrogel film coating, the entire contact lens can simultaneously have an ultra-high oxygen permeability rate, a super-biocompatible and super-lubricated surface; by controlling the internal volume of the liquid sac, after the contact lens reaches the corneal surface, different-shaped lenses are formed, so as to achieve the effect of correcting vision; it has the characteristic of being able to change shape, can be retained in a narrow pipeline in the form of a liquid drop, can be directly dropped into the eye from the pipeline, and spread on the corneal surface, which is convenient to carry and simple to wear. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 FIG. 1 is a schematic structural view of the liquid sac-shaped contact lens of the present invention;

[0043] Figure 2 FIG. 2 is a schematic view of the liquid sac-shaped contact lens of the present invention conforming to the ocular surface;

[0044] Figure 3 FIG. 3 is a schematic process view of the preparation method of the liquid sac-shaped contact lens according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0045] As Figure 1 shown, the liquid sac-shaped contact lens of the present invention is composed of two layers of thin films sandwiching an oxygen-permeable liquid. Both of the two layers of thin films have an affinity hydrogel coating as the interface in contact with the cornea during use, and an elastomer layer is inside the hydrogel coating; the friction between the hydrogel coating and the cornea is extremely small, which can ensure that the liquid sac-shaped contact lens unfolds and forms on the ocular surface. The liquid sac-shaped contact lens of the present invention has no fixed shape. After it conforms to the ocular surface, due to the limited volume, it will present a concave lens shape as Figure 2 shown, thereby achieving the effects of refraction and vision correction.

[0046] Example 1

[0047] As Figure 3 shown, this example is a preferred preparation method for the liquid sac-shaped contact lens, including the following steps:

[0048] 1. Prepare a surface treatment preset solution: Dissolve benzophenone as a surface curing initiator in anhydrous ethanol at a mass fraction of 5%-20% (preferably 10%).

[0049] Prepare a hydrogel prepolymer solution: Dissolve acrylamide as a hydrogel polymer monomer in water at a mass fraction of 10%-30% (preferably 15%), and add 10-200 microliters of an ethanol solution of 0.1 mol / l photoinitiator α-ketoglutaric acid to each milliliter of the above solution.

[0050] 2. Dissolve polyvinyl alcohol in hot water at 60-90°C (preferably 75°C) at a mass fraction of 3%-10% (preferably 5%), and then spin-coat it on a hard substrate (spin-coating speed: 300-1000 revolutions per minute, preferably 500 revolutions per minute, spin-coating time: 2-5 minutes, preferably 3 minutes), and heat to evaporate the water to form a polyvinyl alcohol sacrificial layer film with a thickness of 10-50 microns. Spin-coat a silicone rubber prepolymer solution on the sacrificial layer film to form an elastomer with a thickness of 5-20 microns.

[0051] 3. After the elastomer is cured, surface treatment is performed on the elastomer film to form activation groups on the surface (preferably plasma rinsing for 2 - 5 minutes). The above materials are quickly immersed in the surface treatment preset solution prepared in step 1 for 0.5 - 5 minutes (preferably 1 minute). Then, the above surface is rinsed with excessive absolute ethanol for 1 - 5 minutes (preferably 2 minutes). The obtained rinsed surface is air-dried with nitrogen and then immersed in the hydrogel prepolymer solution prepared in step 1. This hydrogel prepolymer solution is placed under 365 nm ultraviolet light for curing, and the curing time is 15 - 30 minutes (preferably 20 minutes). A hydrophilic hydrogel coating is formed on the cured elastomer surface.

[0052] 4. Immerse the above materials in hot water at 90 °C for more than 6 hours to dissolve the sacrificial layer, and the elastomer film falls off and floats on the water surface.

[0053] 5. Use a hard bottom plate with round holes as shown in Figure 3 to lift the elastomer film (the diameter of the round hole is the diameter of the contact lens), with the side without the hydrogel coating facing outwards. Perform the surface activation treatment on the elastomer surface as described in step 3, and then drop a specific volume of oxygen-permeable liquid (preferably polydimethylsiloxane mother liquid, with a volume of 5 - 20 μL) on the surface. Align the centers of two round-hole hard bottom plates with elastomer films and fit and assemble them to enclose the oxygen-permeable liquid in the elastomer film.

[0054] 6. Place the above materials in an oven and treat them at 65 °C for 24 hours. Then, place the entire mold in water to take out the elastomer film enclosing the liquid droplet, and cut the film along the bonding edge to obtain a contact lens in the form of a liquid sac.

[0055] The hydrogel polymer monomer acrylamide in Example 1 can be replaced with hydrophilic polymers such as hydroxyethyl polymethacrylate and polyvinyl alcohol; the photoinitiator can be replaced with other photoinitiators, such as I2959, PI184, etc.; in Example 1, polyvinyl alcohol is used as the sacrificial layer to prepare the polymer film, and this sacrificial layer can also be realized with other materials, such as photoresist, etc.

[0056] The above-described embodiments have detailed the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, supplements, equivalent replacements, etc. made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A liquid sac-shaped corneal contact lens, characterized in that, It is composed of a transparent thin film and a transparent oxygen-permeable liquid, and the oxygen-permeable liquid is wrapped inside the thin film; The said thin film includes an inner elastomer layer and an outer hydrophilic polymer hydrogel layer; The preparation method of the liquid capsule-shaped corneal contact lens includes the following steps: (1) Prepare a thin film with an elastomer layer and a hydrophilic polymer hydrogel layer; (2) Respectively perform surface activation treatment on the surfaces of the elastomer layers of two thin films, make the elastomer layers of the two thin films face each other, inject a specific volume of oxygen-permeable liquid between the elastomer layers of the two thin films, and then assemble and bond the two thin films to enclose the oxygen-permeable liquid between the two thin films; (3) Cut the thin film along the bonding edge to obtain the liquid capsule-shaped corneal contact lens; According to the shape, size of the corneal surface and the required diopter, design the size of the liquid capsule-shaped corneal contact lens and the injection volume of the oxygen-permeable liquid.

2. The liquid sac-shaped corneal contact lens according to claim 1, wherein, The said elastomer layer is silicone rubber or silicone hydrogel; the hydrogel layer is at least one of polyacrylamide, hydroxyethyl polymethacrylate and polyvinyl alcohol; the oxygen-permeable liquid is at least one of polydimethylsiloxane mother liquor, ethylene glycol and glycerol.

3. The liquid sac-shaped corneal contact lens according to claim 1, characterized in that, The thickness of the elastomer layer is 5-20μm, and the thickness of the hydrophilic polymer hydrogel layer is 0.5-10μm.

4. The liquid sac-shaped corneal contact lens according to claim 1, characterized in that, Step (1) includes: (1-1) Coat a sacrificial layer on a substrate, coat a pre-polymer solution of an elastomer layer on the sacrificial layer, and cure to form an elastomer layer; (1-2) Perform surface activation treatment on the surface of the elastomer layer to form activation groups on its surface; then immerse it in a surface treatment preset solution, rinse and air-dry; then immerse it in a hydrogel pre-polymer solution and cure to form a hydrophilic polymer hydrogel layer on the surface of the elastomer layer; (1-3) Obtain the said thin film after removing the sacrificial layer.

5. The liquid sac-shaped corneal contact lens according to claim 4, wherein, The said sacrificial layer is a polyvinyl alcohol thin film; in step (1-3), the sacrificial layer is removed by hot water immersion.

6. The liquid sac-shaped corneal contact lens according to claim 4, wherein In step (1-2), the surface of the elastomer layer is rinsed with plasma for 2-5 minutes to form activation groups on its surface.

7. The liquid capsule-shaped corneal contact lens according to claim 4, characterized in that, The said hydrogel pre-polymer solution is an aqueous solution of a hydrophilic hydrogel polymer monomer and a photoinitiator, containing 10-30% mass fraction of the hydrophilic hydrogel polymer monomer and 1-20% volume fraction of the photoinitiator solution; the concentration of the photoinitiator in the photoinitiator solution is 0.1mol / L.

8. The liquid sac-shaped corneal contact lens according to claim 7, characterized in that, The said hydrophilic hydrogel polymer monomer is at least one of acrylamide, hydroxyethyl methacrylate and vinyl alcohol; the photoinitiator is at least one of α-ketoglutaric acid, I2959 and PI184.

9. The liquid sac-shaped corneal contact lens according to claim 1, wherein Step (2) includes: (2-1) Use two hard bottom plates with round holes to support one of the said thin films respectively, and make the hydrogel layer close to the hard bottom plate; the size of the round hole is the size of the liquid capsule-shaped corneal contact lens; (2-2) Perform surface activation treatment on the surface of the elastomer layer of the thin film supported by the hard bottom plate, then drop a specific volume of oxygen-permeable liquid onto the surface of the thin film at the round hole of one of the thin films, and then cover the other thin film on the oxygen-permeable liquid, align the two thin films at the round hole and assemble them to enclose the oxygen-permeable liquid between the two thin films; (2-3) Leave the assembled thin films standing at 60-70°C for 18-30 h to bond the two thin films, and after taking them out, cut the thin films along the bonding edge to obtain the liquid sac-shaped corneal contact lens described above.

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