Soft contact lenses with different functional group distributions in the inner and outer layers, and a method for manufacturing the same.

Abstract

This invention provides a soft contact lens with different functional group distributions in the inner and outer layers, and a method for manufacturing the same. [Solution] The soft contact lens includes a lens body which is a hydrogel soft contact lens or a silicone hydrogel soft contact lens. A first functional group distribution layer is formed on the outer convex surface of the lens body, and a second functional group distribution layer is formed on the first functional group distribution layer. Here, the first functional group distribution layer has a first carbon content, a first oxygen content, and a first nitrogen content, and the second functional group distribution layer has a second carbon content, a second oxygen content, and a second nitrogen content. The second oxygen content is 10% to 200% higher than the first oxygen content.

Description

[Technical Field]

[0001] The present invention relates to soft contact lenses, and more particularly to soft contact lenses in which both an inner functional group distribution layer and an outer functional group distribution layer are formed on the surface of the contact lens, and the ratio of elements or functional groups in the inner and outer layers is different. Such a two-layer surface structure can improve the hydrophilicity and wearing comfort of the lens. [Background technology]

[0002] The hydrophilicity of the contact lens surface is one of the factors that affect wearing comfort. While conventional hydrogel soft contact lenses (for example, those based on HEMA) are hydrophilic, prolonged wear can still cause dryness and discomfort due to tear evaporation.

[0003] Silicone hydrogel soft contact lenses contain siloxane components that can improve oxygen permeability. However, the siloxane groups (such as Si-C bonds) increase the hydrophobicity of the lens surface, reducing its wettability. This makes it easier for lipids and proteins to deposit, and further affects wearing comfort and the biocompatibility of the lens.

[0004] To address this problem, conventional techniques often involve modifying the surface of contact lenses to make them hydrophilic. However, most surface treatments only form a single modified layer on the outermost layer of the lens, resulting in limited effectiveness and durability issues.

[0005] Therefore, there remains a need to provide improved contact lenses with innovative designs on the lens surface structure that combine high oxygen permeability and good hydrophilicity to enhance comfort during long-term wear. [Overview of the project] [Problems that the invention aims to solve]

[0006] The present invention provides a soft contact lens, and particularly provides a soft contact lens with different functional group distributions in the inner layer and the outer layer. Such a two-layer surface structure can improve the hydrophilicity and wearing comfort of the lens.

Means for Solving the Problems

[0007] One embodiment of the present invention provides a soft contact lens with different functional group distributions in the inner layer and the outer layer. The soft contact lens includes a lens body which is a hydrogel soft contact lens, and a first functional group distribution layer is formed on the outer convex surface of the lens body, and a second functional group distribution layer is formed on the first functional group distribution layer. The first functional group distribution layer has a first carbon content, a first oxygen content, and a first nitrogen content. The second functional group distribution layer has a second carbon content, a second oxygen content, and a second nitrogen content. The second oxygen content is 10% to 200% higher than the first oxygen content, and the second nitrogen content is 10% to 150% higher than the first nitrogen content.

[0008] Preferably, the second oxygen content is 20% to 100% higher than the first oxygen content, and the second nitrogen content is 30% to 70% higher than the first nitrogen content.

[0009] Preferably, the first functional group distribution layer has at least functional groups of a carbonyl group (C=O), an ether group (C-O-C), a hydroxyl group (C-OH), a primary amine (NH2), and a secondary amine (NH), and the second functional group distribution layer has at least functional groups of a carbonyl group (C=O), an ether group (C-O-C), a hydroxyl group (C-OH), a primary amine (NH2), a secondary amine (NH), an ammonium ion (NH3 + ), and a quaternary ammonium cation (NR4 + ).

[0010] Preferably, the first functional group distribution layer contains carbonyl groups (C=O), ether groups (COC), hydroxyl groups (C-OH), primary amines (NH2), secondary amines (NH3), and ammonium ions (NH3). + ), and quaternary ammonium cation (NR4 + The second functional group distribution layer has at least the following functional groups: carbonyl group (C=O), ether group (COC), hydroxyl group (C-OH), primary amine (NH2), secondary amine (NH), and ammonium ion (NH3). + ), and quaternary ammonium cation (NR4 + It has at least one of the functional groups of ).

[0011] Preferably, the first carbon content is determined by the carbon element content of the carbon-containing functional group in the first functional group distribution layer, and the carbon-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (COC), and a hydroxyl group (C-OH).

[0012] Preferably, the first oxygen content is determined by the oxygen element content of the oxygen-containing functional group in the first functional group distribution layer, and the oxygen-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (COC), and a hydroxyl group (C-OH).

[0013] Preferably, the first nitrogen content is determined by the nitrogen element content of the nitrogen-containing functional groups in the first functional group distribution layer, wherein the nitrogen-containing functional groups include primary amines (NH2), secondary amines (NH3), and ammonium ions (NH3). + ), and quaternary ammonium cation (NR4 + It contains at least one functional group selected from ).

[0014] Preferably, the second carbon content is determined by the carbon element content of the carbon-containing functional groups in the second functional group distribution layer, and the carbon-containing functional groups include at least one functional group selected from a carbonyl group (C=O), an ether group (C-O-C), and a hydroxyl group (C-OH).

[0015] Preferably, the second oxygen content is determined by the oxygen element content of the oxygen-containing functional groups in the second functional group distribution layer, and the oxygen-containing functional groups include at least one functional group selected from a carbonyl group (C=O), an ether group (C-O-C), and a hydroxyl group (C-OH).

[0016] Preferably, the second nitrogen content is determined by the nitrogen element content of the nitrogen-containing functional groups in the second functional group distribution layer, and the nitrogen-containing functional groups include at least one functional group selected from a primary amine (NH2), a secondary amine (NH), an ammonium ion (NH3 + ), and a quaternary ammonium cation (NR4 + ).

[0017] Preferably, the content of the carbonyl group (C=O) of the carbon-containing functional groups in the second functional group distribution layer is 5% to 150% higher than the content of the carbonyl group (C=O) of the carbon-containing functional groups in the first functional group distribution layer, and the contents of the ether group (C-O-C) and the hydroxyl group (C-OH) of the carbon-containing functional groups in the second functional group distribution layer are 5% to 120% higher than the contents of the ether group (C-O-C) and the hydroxyl group (C-OH) of the carbon-containing functional groups in the first functional group distribution layer.

[0018] Preferably, the content of carbonyl groups (C=O) of carbon-containing functional groups in the second functional group distribution layer is 20% to 130% higher than the content of carbonyl groups (C=O) of carbon-containing functional groups in the first functional group distribution layer, and the content of ether groups (COC) and hydroxyl groups (C-OH) of carbon-containing functional groups in the second functional group distribution layer is 5% to 80% higher than the content of ether groups (COC) and hydroxyl groups (C-OH) of carbon-containing functional groups in the first functional group distribution layer.

[0019] Preferably, the content of ether groups (COC) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the second functional group distribution layer is 10% to 200% higher than the content of ether groups (COC) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the first functional group distribution layer, and the content of carbonyl groups (C=O) of oxygen-containing functional groups in the second functional group distribution layer is 10% to 200% higher than the content of carbonyl groups (C=O) of oxygen-containing functional groups in the first functional group distribution layer.

[0020] Preferably, the content of ether groups (COC) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the second functional group distribution layer is 10% to 60% higher than the content of ether groups (COC) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the first functional group distribution layer, and the content of carbonyl groups (C=O) of oxygen-containing functional groups in the second functional group distribution layer is 10% to 50% higher than the content of carbonyl groups (C=O) of oxygen-containing functional groups in the first functional group distribution layer.

[0021] Preferably, the content of primary amines (NH2) and secondary amines (NH) of nitrogen-containing functional groups in the second functional group distribution layer is 10% to 150% higher than the content of primary amines (NH2) and secondary amines (NH) of nitrogen-containing functional groups in the first functional group distribution layer, and the content of ammonium ions (NH3) of nitrogen-containing functional groups in the second functional group distribution layer is 10% to 150% higher. + ) and quaternary ammonium cation (NR4 + The content of ) is the ammonium ion (NH3) of nitrogen-containing functional groups in the first functional group distribution layer.+ ) and quaternary ammonium cation (NR4 + It contains at least 10% more than the amount of ).

[0022] Preferably, the content of primary amines (NH2) and secondary amines (NH) of nitrogen-containing functional groups in the second functional group distribution layer is 50% to 70% higher than the content of primary amines (NH2) and secondary amines (NH) of nitrogen-containing functional groups in the first functional group distribution layer.

[0023] Preferably, the adhesive force of the surface of the optical zone of the contact lens, as measured by atomic force microscopy (AFM) force curve testing, is 2 nN or less.

[0024] Preferably, the contact angle hysteresis of the second functional group distribution layer, as measured by dynamic contact angle (DCA) measurement, is reduced by 20% to 95% compared to the first functional group distribution layer.

[0025] Preferably, at least the second functional group distribution layer is formed by surface plasma treatment.

[0026] Preferably, the second functional group distribution layer is formed such that the ratio of nitrogen to oxygen used in the surface plasma treatment is 9:1 to 3:7.

[0027] Another embodiment of the present invention provides a soft contact lens. The soft contact lens comprises a lens body which is a silicone hydrogel soft contact lens, wherein a first functional group distribution layer is formed on the outer convex surface of the lens body, and a second functional group distribution layer is formed on the first functional group distribution layer, wherein the first functional group distribution layer has a first carbon content, a first oxygen content and a first nitrogen content, and the second functional group distribution layer has a second carbon content, a second oxygen content and a second nitrogen content, wherein the second oxygen content is 10% to 200% higher than the first oxygen content.

[0028] Preferably, the second oxygen content is 20% to 110% higher than the first oxygen content.

[0029] Preferably, the first functional group distribution layer has at least the functional groups carbonyl group (C=O), ether group (COC), hydroxyl group (C-OH), and silicon-carbon bond (Si-C), and the second functional group distribution layer has carbonyl group (C=O), ether group (COC), hydroxyl group (C-OH), silicon-carbon bond (Si-C), and ammonium ion (NH3 + ), and quaternary ammonium cation (NR4 + It has at least one of the functional groups of ).

[0030] Preferably, the first functional group distribution layer includes carbonyl groups (C=O), ether groups (COC), hydroxyl groups (C-OH), silicon-carbon bonds (Si-C), and ammonium ions (NH3). + ), and quaternary ammonium cation (NR4 + The second functional group distribution layer has at least the following functional groups: carbonyl group (C=O), ether group (COC), hydroxyl group (C-OH), silicon-carbon bond (Si-C), and ammonium ion (NH3 + ), and quaternary ammonium cation (NR4 + It has at least one of the functional groups of ).

[0031] Preferably, the first carbon content is determined by the carbon element content of the carbon-containing functional group in the first functional group distribution layer, and the carbon-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (COC), a hydroxyl group (C-OH), and a silicon-carbon bond (Si-C).

[0032] Preferably, the first oxygen content is determined by the oxygen element content of the oxygen-containing functional group in the first functional group distribution layer, and the oxygen-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (COC), and a hydroxyl group (C-OH).

[0033] Preferably, the first nitrogen content is determined by the nitrogen element content of the nitrogen-containing functional group in the first functional group distribution layer, wherein the nitrogen-containing functional group contains ammonium ions (NH3 + ), and quaternary ammonium cation (NR4 + ) includes.

[0034] Preferably, the second carbon content is determined by the carbon element content of the carbon-containing functional group in the second functional group distribution layer, and the carbon-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (COC), a hydroxyl group (C-OH), and a silicon-carbon bond (Si-C).

[0035] Preferably, the second oxygen content is determined by the oxygen element content of the oxygen-containing functional group in the second functional group distribution layer, and the oxygen-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (COC), and a hydroxyl group (C-OH).

[0036] Preferably, the second nitrogen content is determined by the nitrogen element content of the nitrogen-containing functional group in the second functional group distribution layer, wherein the nitrogen-containing functional group contains ammonium ions (NH3 + ), and quaternary ammonium cation (NR4 + ) includes.

[0037] Preferably, the content of carbonyl groups (C=O) of carbon-containing functional groups in the second functional group distribution layer is 3% to 150% higher than the content of carbonyl groups (C=O) of carbon-containing functional groups in the first functional group distribution layer, and the content of silicon-carbon bonds (Si-C) of carbon-containing functional groups in the second functional group distribution layer is 10% to 90% lower than the content of silicon-carbon bonds (Si-C) of carbon-containing functional groups in the first functional group distribution layer.

[0038] Preferably, the content of carbonyl groups (C=O) of carbon-containing functional groups in the second functional group distribution layer is 3% to 90% higher than the content of carbonyl groups (C=O) of carbon-containing functional groups in the first functional group distribution layer, and the content of silicon-carbon bonds (Si-C) of carbon-containing functional groups in the second functional group distribution layer is 40% to 70% lower than the content of silicon-carbon bonds (Si-C) of carbon-containing functional groups in the first functional group distribution layer. Preferably, the content of ether groups (COC) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the second functional group distribution layer is 10% to 400% higher than the content of ether groups (COC) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the first functional group distribution layer.

[0039] Preferably, the content of ether groups (COC) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the second functional group distribution layer is 40% to 310% higher than the content of ether groups (COC) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the first functional group distribution layer.

[0040] Preferably, the nitrogen-containing functional group in the second functional group distribution layer contains an ammonium ion (NH3 + ) and quaternary ammonium cation (NR4 + The content of ) is the ammonium ion (NH3) of nitrogen-containing functional groups in the first functional group distribution layer. + ) and quaternary ammonium cation (NR4 + It contains at least 10% more than the amount of ).

[0041] Preferably, the adhesive force of the surface of the optical zone of the contact lens, as measured by atomic force microscopy (AFM) force curve testing, is 2 nN or less.

[0042] Preferably, the contact angle hysteresis of the second functional group distribution layer, as measured by dynamic contact angle (DCA) measurement, is reduced by 20% to 95% compared to the first functional group distribution layer.

[0043] Preferably, at least the second functional group distribution layer is formed by surface plasma treatment.

[0044] Preferably, the second functional group distribution layer is formed such that the ratio of nitrogen to oxygen used in the surface plasma treatment is 9:1 to 3:7.

[0045] Another embodiment of the present invention provides a method for manufacturing a soft contact lens in which the functional group distribution of the inner and outer layers differs. The method for manufacturing a soft contact lens in which the functional group distribution of the inner and outer layers differs includes the steps of providing a lens body which is a hydrogel soft contact lens or a silicone hydrogel soft contact lens, wherein the lens body has a first functional group distribution layer on its outer convex surface, and the first functional group distribution layer has a first carbon content, a first oxygen content and a first nitrogen content, and forming a second functional group distribution layer on the first functional group distribution layer, wherein the second functional group distribution layer has a second carbon content, a second oxygen content and a second nitrogen content, and the second oxygen content is 10% to 200% higher than the first oxygen content. [Effects of the Invention]

[0046] As described above, the soft contact lens of the present invention has a first functional group distribution layer (inner layer) and a second functional group distribution layer (outer layer) formed on the curved surface of the lens. The distribution ratios of elements or functional groups contained in these two layers are different, and the surface of the second functional group distribution layer has higher hydrophilicity. In other words, by differentiating the two-layer surface functional group structure of the inner and outer layers, it is possible to effectively improve the wettability of the lens while improving wearing comfort. [Brief explanation of the drawing]

[0047] [Figure 1] This is a schematic diagram of the contact lens of the present invention having different functional group distribution layers. [Figure 2-1a] This is a C1sX-ray photoelectron spectroscopy (XPS) graph of the lens from Example 2-1. [Figure 2-1b]This is an O1sX-ray photoelectron spectroscopy (XPS) graph of the lens from Example 2-1. [Figure 2-1c] This is an analytical diagram of the contact angle hysteresis of the lens in Example 2-1. [Figure 2-2a] This is a C1sX-ray photoelectron spectroscopy (XPS) graph of the lens in Example 2-2. [Figure 2-2b] This is an O1s X-ray photoelectron spectroscopy (XPS) graph of the lens from Example 2-2. [Figure 2-2c] This is an analytical diagram of the contact angle hysteresis of the lens in Example 2-2. [Figure 3-1a] This is a C1sX-ray photoelectron spectroscopy (XPS) graph of the lens from Example 3-1. [Figure 3-1b] This is an O1sX-ray photoelectron spectroscopy (XPS) graph of the lens from Example 3-1. [Figure 3-1c] This is an analytical diagram of the contact angle hysteresis of the lens in Example 3-1. [Figure 3-2a] This is a C1sX-ray photoelectron spectroscopy (XPS) graph of the lens from Example 3-2. [Figure 3-2b] This is an O1s X-ray photoelectron spectroscopy (XPS) graph of the lens from Example 3-2. [Modes for carrying out the invention]

[0048] To better understand the features and technical content of the present invention, the following detailed description and drawings of the present invention will be referenced; however, the provided description and drawings are for reference and illustrative purposes only and do not limit the present invention.

[0049] In the following explanations, when there are phrases such as "consider specific drawings" or "as shown in specific drawings," these are merely to emphasize that the content of the subsequent explanations is generally described in those specific drawings, and other drawings may also be consulted.

[0050] The present invention relates to soft contact lenses, and more particularly to soft contact lenses in which two functional group distribution layers, an inner layer and an outer layer, are formed on the surface of the contact lens, and the inner layer and the outer layer have different elemental or functional group content ratios. Such a two-layer surface structure can improve the hydrophilicity and wearing comfort of the lens.

[0051] More specifically, as shown in Figure 1, the soft contact lens E according to an embodiment of the present invention includes a lens body 1, in which a first functional group distribution layer 21 is formed on the outer convex surface of the lens body 1, and a second functional group distribution layer 22 is formed on the outer surface of the first functional group distribution layer 21 in this order. Here, the distribution of elements and functional groups in the second functional group distribution layer 22 (outer layer) is different from that of the first functional group distribution layer 21 (inner layer), thereby forming a soft contact lens in which the functional group distributions of the inner and outer layers are different.

[0052] In one embodiment of the present invention, by applying an appropriate surface treatment (such as plasma treatment or chemical treatment) to the outer surface of the lens body 1 to form a second functional group distribution layer 22 on the outer surface of the first functional group distribution layer 21, the second functional group distribution layer 22 and the first functional group distribution layer 21 can be made to have different elemental content distributions.

[0053] It should be explained that the surface treatment method for forming the inner and outer functional group distribution layers is not limited to a specific method, and various methods such as plasma treatment, surface grafting, and coating can be used. As long as a two-layer structure with different component ratios for the inner and outer layers can be formed on the lens surface, it falls within the scope of the present invention.

[0054] Preferably, when employing plasma treatment, a nitrogen / oxygen mixed gas can be used, and by setting the volume ratio of nitrogen to oxygen in the range of 9:1 to 3:7, a good hydrophilic layer can be formed on the lens surface.

[0055] A series of hydrophilicity evaluation experiments (including X-ray photoelectron spectroscopy (XPS), dynamic contact angle measurement (DCA), and atomic force microscopy (AFM) adhesion tests) demonstrated that the contact lenses provided by embodiments of the present invention exhibit significantly improved surface hydrophilicity and, furthermore, improved wearing comfort compared to conventional lenses that lack the inner and outer functional group distribution layers. In addition, in embodiments of the present invention, lenses were evaluated through clinical wear tests such as tear film breakdown time (NIKBUT) tests and subjective wearer questionnaires. As a result, the soft contact lenses of the present invention with different functional group distributions in the inner and outer layers showed superior performance in actual wearing performance compared to the control group lenses.

[0056] Furthermore, the lens material of the soft contact lens E can be divided into hydrogel soft contact lenses and silicone hydrogel soft contact lenses, and for a detailed explanation, please refer to the following first and second embodiments.

[0057] [Hydrogel soft contact lenses] One embodiment of the present invention provides a soft contact lens in which the functional group distribution of the inner and outer layers differs. The soft contact lens includes a lens body which is a hydrogel soft contact lens. A first functional group distribution layer is formed on the outer convex surface of the lens body, and a second functional group distribution layer is formed on the first functional group distribution layer. The first functional group distribution layer has a first carbon content, a first oxygen content, and a first nitrogen content. The second functional group distribution layer has a second carbon content, a second oxygen content, and a second nitrogen content. The second oxygen content is 10% to 200% higher than the first oxygen content, and the second nitrogen content is 10% to 150% higher than the first nitrogen content. In this way, the lens can be given better wettability and further improved wearing comfort for long periods of time.

[0058] In one embodiment of the present invention, the second oxygen content may be 20% to 100% higher than the first oxygen content, and the second nitrogen content may be 30% to 70% higher than the first nitrogen content. In this case, the surface of the outer layer contains more polar functional groups, which can significantly improve the hydrophilicity of the hydrogel lens.

[0059] In one embodiment of the present invention, the first functional group distribution layer has at least the functional groups of a carbonyl group (C=O), an ether group (COC), a hydroxyl group (C-OH), a primary amine (NH2), and a secondary amine (NH). The second functional group distribution layer has a carbonyl group (C=O), an ether group (COC), a hydroxyl group (C-OH), a primary amine (NH2), a secondary amine (NH), and an ammonium ion (NH3). + ), and quaternary ammonium cation (NR4 + It has at least one of the functional groups of ).

[0060] The hydrophilicity can be further enhanced by introducing nitrogen-containing functional groups (particularly ammonium ions / quaternary ammonium groups) into the second functional group distribution layer (outer layer), but the present invention is not limited thereto.

[0061] In one embodiment of the present invention, the first functional group distribution layer is an ammonium ion (NH3 + ) and quaternary ammonium cation (NR4 + The second functional group distribution layer may also contain at least these functional groups.

[0062] Furthermore, the first carbon content is determined by the carbon element content of the carbon-containing functional group in the first functional group distribution layer, and the carbon-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (COC), and a hydroxyl group (C-OH).

[0063] The first oxygen content is determined by the oxygen element content of the oxygen-containing functional group in the first functional group distribution layer, and the oxygen-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (COC), and a hydroxyl group (C-OH).

[0064] The first nitrogen content is determined by the nitrogen element content of the nitrogen-containing functional groups in the first functional group distribution layer, and the nitrogen-containing functional groups include primary amines (NH2), secondary amines (NH3), and ammonium ions (NH3). + ), and quaternary ammonium cation (NR4 + It contains at least one functional group selected from ).

[0065] The second carbon content is determined by the carbon element content of the carbon-containing functional group in the second functional group distribution layer, and the carbon-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (COC), and a hydroxyl group (C-OH).

[0066] The second oxygen content is determined by the oxygen element content of the oxygen-containing functional group in the second functional group distribution layer, and the oxygen-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (COC), and a hydroxyl group (C-OH).

[0067] The second nitrogen content is determined by the nitrogen element content of the nitrogen-containing functional groups in the second functional group distribution layer, and the nitrogen-containing functional groups include primary amines (NH2), secondary amines (NH3), and ammonium ions (NH3). + ), and quaternary ammonium cation (NR4 + It contains at least one functional group selected from ).

[0068] In one embodiment of the present invention, the content of carbonyl groups (C=O) of carbon-containing functional groups in the second functional group distribution layer is about 5% to 150% higher than the content of carbonyl groups (C=O) of carbon-containing functional groups in the first functional group distribution layer, and the content of ether groups (COC) and hydroxyl groups (C-OH) of carbon-containing functional groups in the second functional group distribution layer is 5% to 120% higher than the content of ether groups (COC) and hydroxyl groups (C-OH) of carbon-containing functional groups in the first functional group distribution layer. More precisely, the increase in carbonyl groups (C=O) in the second functional group distribution layer can reach 20% to 130%, and the increase in ether groups and hydroxyl groups can reach about 5% to 80%.

[0069] Comparing oxygen-containing functional groups, the ether and hydroxyl groups in the second functional group distribution layer may be 10% to 200% higher than in the first functional group distribution layer, and the carbonyl groups can be increased by 10% to 200%.

[0070] More preferably, the ether and hydroxyl groups of oxygen-containing functional groups in the second functional group distribution layer may be 10% to 60% higher than in the first functional group distribution layer, and the carbonyl groups can be increased by 10% to 50%.

[0071] With respect to nitrogen-containing functional groups, the content of primary amines (NH2) and secondary amines (NH) of nitrogen-containing functional groups in the second functional group distribution layer can be increased by 10% to 150% compared to the first functional group distribution layer, and ammonium ions (NH3) + ) and quaternary ammonium cation (NR4 + The content of ) will increase by at least 10%, and could even increase by 50% to 70%.

[0072] While the embodiments of the present invention demonstrate a high degree of freedom and diverse applicability in adjusting the hydrophilicity of the outer surface of a lens by changing the proportion of such multiple functional groups, the present invention is not limited thereto.

[0073] In one embodiment of the present invention, the adhesive force of the surface of the optical zone of the contact lens, as measured by atomic force microscopy (AFM) force curve test, is 2nN or less, indicating that the outer layer has very high hydrophilicity.

[0074] When performing dynamic contact angle (DCA) measurement tests, the contact angle hysteresis of the second functional group distribution layer is reduced by 20% to 95% compared to the first functional group distribution layer, indicating that the second functional group distribution layer exhibits relatively superior wetting properties. Here, the contact angle hysteresis of the second functional group distribution layer is 10° or less (difference between advance angle and receding angle), and preferably between 1° and 5°.

[0075] In one embodiment of the present invention, at least the second functional group distribution layer can be formed by surface plasma treatment. Preferably, introducing more polar groups into the outer layer by using a nitrogen / oxygen ratio of 9:1 to 3:7 in the plasma treatment can significantly improve the comfort of the hydrogel lens, but the present invention is not limited thereto.

[0076] [Silicone hydrogel soft contact lenses] A second embodiment of the present invention provides a different type of soft contact lens, wherein the lens body is a silicone hydrogel soft contact lens. Specifically, a first functional group distribution layer is similarly formed on the outer convex surface of the lens body, and a second functional group distribution layer is formed on the first functional group distribution layer. The first functional group distribution layer has a first carbon content, a first oxygen content, and a first nitrogen content, and the second functional group distribution layer has a second carbon content, a second oxygen content, and a second nitrogen content.

[0077] More specifically, the second oxygen content may be 10% to 200% higher than the first oxygen content, and by increasing the oxygen-containing groups in the outer layer and reducing the proportion of the hydrophobic portion of the siloxane (Si-C), a better balance between high oxygen permeability and high hydrophilicity can be achieved, but the present invention is not limited thereto.

[0078] In one embodiment of the present invention, the second oxygen content is 20% to 110% higher than the first oxygen content.

[0079] The first functional group distribution layer has at least the functional groups carbonyl group (C=O), ether group (COC), hydroxyl group (C-OH), and silicon-carbon bond (Si-C). The second functional group distribution layer has at least the functional groups carbonyl group (C=O), ether group (COC), hydroxyl group (C-OH), and silicon-carbon bond (Si-C), and also has ammonium ions (NH3 + ) and quaternary ammonium cation (NR4 + The hydrophilicity of the outer layer of the lens can be further enhanced by including ), but the present invention is not limited thereto.

[0080] Alternatively, the first functional group distribution layer may consist of carbonyl groups (C=O), ether groups (COC), hydroxyl groups (C-OH), silicon-carbon bonds (Si-C), and ammonium ions (NH3). + ), and quaternary ammonium cation (NR4 + The second functional group distribution layer has at least the following functional groups: carbonyl group (C=O), ether group (COC), hydroxyl group (C-OH), silicon-carbon bond (Si-C), and ammonium ion (NH3 + ), and quaternary ammonium cation (NR4 + It has at least one of the functional groups of ).

[0081] Furthermore, the first carbon content is determined by the carbon element content of the carbon-containing functional group in the first functional group distribution layer, and the carbon-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (COC), a hydroxyl group (C-OH), and a silicon-carbon bond (Si-C).

[0082] The first oxygen content is determined by the oxygen element content of the oxygen-containing functional group in the first functional group distribution layer, and the oxygen-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (COC), and a hydroxyl group (C-OH).

[0083] The first nitrogen content is determined by the nitrogen element content of the nitrogen-containing functional group in the first functional group distribution layer, and the nitrogen-containing functional group contains ammonium ions (NH3 + ), and quaternary ammonium cation (NR4 + ) includes.

[0084] The second carbon content is determined by the carbon element content of the carbon-containing functional group in the second functional group distribution layer, and the carbon-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (COC), a hydroxyl group (C-OH), and a silicon-carbon bond (Si-C).

[0085] The second oxygen content is determined by the oxygen element content of the oxygen-containing functional group in the second functional group distribution layer, and the oxygen-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (COC), and a hydroxyl group (C-OH).

[0086] The second nitrogen content is determined by the nitrogen element content of the nitrogen-containing functional group in the second functional group distribution layer, and the nitrogen-containing functional group contains ammonium ions (NH3 + ), and quaternary ammonium cation (NR4 + ) includes.

[0087] In one embodiment, the content of carbonyl groups (C=O) of carbon-containing functional groups in the second functional group distribution layer may be 3% to 150% higher than that of the first functional group distribution layer, and more preferably 3% to 90%. The content of silicon-carbon bonds (Si-C) of carbon-containing functional groups in the second functional group distribution layer may be 10% to 90% lower than that of the first functional group distribution layer, and more preferably 40% to 70% lower.

[0088] Furthermore, the content of ether groups (COC) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the second functional group distribution layer can be increased by 10% to 400% compared to the first functional group distribution layer, and is more preferably increased in the range of 40% to 310%. The ammonium ion / quaternary ammonium group of nitrogen-containing functional groups in the second functional group distribution layer may be increased by at least 10% compared to the first functional group distribution layer, but the present invention is not limited thereto.

[0089] In one embodiment of the present invention, the adhesive force of the surface of the optical zone of the contact lens, as measured by an atomic force microscope (AFM) force curve test, is 2 nN or less. Furthermore, the contact angle hysteresis of the second functional group distribution layer, as measured by a dynamic contact angle (DCA) measurement test, is reduced by 20% to 95% compared to the first functional group distribution layer. This means that the surface hydrophilicity of the silicone hydrogel lens has been significantly improved. Here, the contact angle hysteresis of the second functional group distribution layer is approximately 50° or less (difference between advance angle and receding angle), and preferably 40 to 50°.

[0090] In one embodiment of the present invention, at least the second functional group distribution layer can be formed by surface plasma treatment. Furthermore, the plasma treatment can be performed such that the volume ratio of nitrogen to oxygen is in the range of 9:1 to 3:7, thereby allowing the silicone hydrogel lens to maintain high oxygen permeability while exhibiting good hydrophilicity, but the present invention is not limited thereto.

[0091] As described above, the first embodiment (application to hydrogel) and the second embodiment (application to silicone hydrogel) are specific reference embodiments of the present invention. By providing a first functional group distribution layer and a second functional group distribution layer on the outer surface of the lens and adjusting the difference in functional group content between the inner and outer layers, the wettability and wearing comfort of soft contact lenses can be significantly improved. However, with respect to other structures, component formulations, and process conditions not explicitly described, various modifications and changes are possible without departing from the scope of the appended claims, based on the spirit and technical means of the present invention.

[0092] [Contact lens manufacturing method] Another embodiment of the present invention provides a method for manufacturing soft contact lenses in which the functional group distribution of the inner and outer layers differs, comprising steps S110 and S120.

[0093] Step S110 includes providing a lens body which is a hydrogel soft contact lens or a silicone hydrogel soft contact lens, wherein the lens body has a first functional group distribution layer on its outer convex surface, and the first functional group distribution layer has a first carbon content, a first oxygen content, and a first nitrogen content.

[0094] Step 120 includes forming a second functional group distribution layer on the first functional group distribution layer, wherein the second functional group distribution layer has a second carbon content, a second oxygen content, and a second nitrogen content.

[0095] Here, the second oxygen content is 10% to 200% higher than the first oxygen content.

[0096] In one embodiment, the step of forming the second functional group distribution layer includes subjecting the lens body to surface plasma treatment so that the surface of the outer layer is richly in polar functional groups or positively charged amino groups, thereby improving comfort during prolonged wear, but the present invention is not limited thereto.

[0097] In one embodiment, the ratio of nitrogen to oxygen used in the surface plasma treatment is 9:1 to 3:7 (preferably 9:1 to 6:4), thereby simultaneously introducing oxygen-containing functional groups and nitrogen-containing functional groups to the lens surface and relatively reducing the proportion of hydrophobic functional groups; however, the present invention is not limited thereto.

[0098] In one embodiment, the first functional group distribution layer on the lens body is formed during the polymerization or hydration process of the lens, and the structure of the first functional group distribution layer is further stabilized by subsequent modification steps (such as leaching, washing, or UV irradiation), but the present invention is not limited thereto.

[0099] [Experimental data and measurement results] Regarding Example 1, in order to evaluate the effect of the embodiment of the present invention on improving the hydrophilicity of the contact lens surface, the relevant measurement method will first be described.

[0100] X-ray photoelectron spectroscopy (XPS) is a surface elemental analysis technique that can measure the types, proportions, and bonding states of elements present on a material surface. The analytical method involves irradiating the sample surface with X-rays and measuring the energy of the excited and emitted electrons to estimate the corresponding elements and their chemical states. In the embodiment of this invention, XPS is used to measure the elemental composition of the inner layer (first functional group distribution layer) and outer layer (second functional group distribution layer) of the lens surface, with particular attention paid to changes in the content of hydrophilic elements such as carbon (C), oxygen (O), and nitrogen (N). For example, the C1s peak analyzed by XPS can determine the proportion of carbon-containing functional groups such as carbonyl groups (C=O), ether groups (COC), and silicon-carbon bonds (Si-C). The O1s peak reflects the proportion of oxygen-containing functional groups such as carbonyl groups (C=O), ether groups (COC), and hydroxyl groups (C-OH). The N1s peak indicates amino groups (NH2, NH) and ammonium groups (NH3 + NR4 + This indicates the proportion of nitrogen-containing functional groups such as ). By comparing the XPS peak intensity ratio of the inner and outer layers, the difference in the content of each element and functional group in the two layers can be quantified.

[0101] Regarding dynamic contact angle (DCA) measurement, the contact angle is an important indicator for evaluating the wettability of a material surface. Since soft contact lenses are used in aquatic environments, the captive bubble method is often used to measure the dynamic contact angle of the lens surface in water. The dynamic contact angle consists of the advance angle and the receding angle, and the difference between these two is called contact angle hysteresis. In the following examples, contact angle hysteresis is used as the criterion for evaluating wettability. This is because, compared to a single static contact angle, contact angle hysteresis can reduce errors due to measuring instruments, environmental conditions, and human factors. Generally, when both the advance angle and the receding angle are less than 90° and the hysteresis value is close to 0, the material surface has extremely good wettability, and the lower the hysteresis value, the better the hydrophilicity of the material surface. In the following examples, the surface modification effect was evaluated by comparing the contact angle hysteresis of the inner and outer layers of the lens. In the examples, 10 test lenses were measured and analyzed, and the average value was calculated.

[0102] Atomic Force Microscopy (AFM) Adhesion Test: AFM, which can detect nanoscale surface properties, can be used to measure the surface adhesion force of a lens surface. During measurement, the tip of the AFM probe contacts the sample surface and gradually moves away, recording a force-distance curve that shows how the force applied to the probe changes with distance. From this force curve, the maximum adhesion force at the moment the probe leaves the sample surface can be read. In the embodiment of the present invention, the optical zone of the lens is used as the measurement position for the AFM adhesion test. As mentioned above, the lower the adhesion force value, the more hydrophilic the material surface is. Therefore, by comparing the AFM adhesion forces of the inner layer (first functional group distribution layer) and the outer layer (second functional group distribution layer), the effect of differences in surface functional group distribution on hydrophilicity can be verified. In the embodiment, 10 test lenses were measured and analyzed, and the average value was calculated.

[0103] Example 2-1 is a hydrogel soft contact lens (contact lens 2-1).

[0104] This embodiment provides a hydrogel soft contact lens 2-1. The lens body of the hydrogel soft contact lens 2-1 is manufactured from a hydrogel composition containing 85 parts by weight of 2-hydroxyethyl methacrylate (HEMA), 1 part by weight of methacrylic acid (MAA), 0.75 parts by weight of ethylene glycol dimethacrylate (crosslinking agent), 0.5 parts by weight of Irgacure 819 (photoinitiator), 0.15 parts by weight of dye (Reactive Blue 19), and 12.6 parts by weight of glycerin.

[0105] The hydrogel composition was injected into the cavity of a polypropylene mold, and polymerization and crosslinking reactions were induced by irradiation with ultraviolet light for 12 minutes to form the lens body. By hydrating the lens body, a hydrogel soft contact lens was obtained.

[0106] Here, a first functional group distribution layer (inner layer) is formed on the outer convex surface of the lens body. By XPS analysis, the content and composition of surface elements of the first functional group distribution layer can be measured, and the first functional group distribution layer has a first carbon content, a first oxygen content, and a first nitrogen content. The first functional group distribution layer contains carbon and oxygen-containing functional groups such as carbonyl groups (C=O), ether groups (COC), and hydroxyl groups (C-OH). According to XPS analysis, signals of nitrogen-containing groups were also confirmed in the first functional group distribution layer, and these signals are, for example, ammonium ions (NH3) derived from the decomposition products of the residual initiator. + ) or quaternary ammonium cation (NR4 + Therefore, the first functional group distribution layer is thought to contain carbon and oxygen-containing functional groups such as carbonyl groups, ether groups, and hydroxyl groups, as well as primary amines (NH2), secondary amines (NH3), and ammonium ions (NH3). + ), and quaternary ammonium cation (NR4 + It contains at least one nitrogen-containing functional group, such as ).

[0107] Next, the lens body was surface-treated to form a second functional group distribution layer (outer layer) on the first functional group distribution layer (inner layer). In this embodiment, plasma treatment was used. In this plasma treatment, the lens was exposed to a plasma environment with a nitrogen / oxygen ratio of 6:4 under atmospheric pressure for a plasma treatment time of 0.2 seconds to 600 seconds (approximately 120 seconds in this embodiment) and a plasma treatment power of 300 watts to 1,200 watts (approximately 550 watts in this embodiment). Then, the lens was extracted in borate-buffered saline with a pH of 7.3 to 7.4, and subsequently subjected to autoclaving to produce the hydrogel soft contact lens 2-1 of this embodiment. After such treatment, a thin modified region is formed on the surface of the first functional group distribution layer, which becomes the second functional group distribution layer (outer layer). The second carbon content, second oxygen content, and second nitrogen content of the second functional group distribution layer can be measured by XPS analysis. The XPS analysis results for hydrogel soft contact lens example 2-1 are shown in Figure 2-1a (comparison of inner and outer layers in XPS elemental analysis C1s scan signals), Figure 2-1b (comparison of inner and outer layers in XPS elemental analysis O1s scan signals), and Table 1 below (differences in surface properties due to improved hydrophilicity).

[0108] The experimental results showed that the second functional group distribution layer (outer layer) had similar types of functional groups to the first functional group distribution layer (inner layer), but the elemental ratios were different. Specifically, the second functional group distribution layer contained relatively higher amounts of oxygen-containing functional groups such as carbonyl groups (C=O), ether groups (COC), and hydroxyl groups (C-OH), as well as carbon-containing functional groups, compared to the first functional group distribution layer. At the same time, for example, primary amines (NH2), secondary amines (NH), and ammonium ions (NH3) were also detected. + ), or quaternary ammonium cation (NR4 + The content of nitrogen-containing functional groups such as ) was also observed to increase in the second functional group distribution layer (see Table 1 below).

[0109] As shown in Figure 2-1c, DCA dynamic contact angle testing revealed that the average contact angle hysteresis of the second functional group distribution layer (outer layer) of the lens in Example 2-1 decreased to approximately 3°, which is significantly lower than the value of the first functional group distribution layer (inner layer) (37.3°), representing a reduction of approximately 91.9%. Similarly, AFM measurements revealed that the average adhesive strength of the outer layer was significantly lower than that of the inner layer (e.g., approximately 1.5 nN for the outer layer and approximately 4.5 nN for the inner layer). These results support the conclusion that the second functional group distribution layer formed by surface plasma treatment significantly improves the hydrophilicity of the lens surface, resulting in a significant improvement in the surface wettability of contact lens 2-1 compared to the untreated surface.

[0110] Example 2-2 is a hydrogel soft contact lens (color lens 2-2).

[0111] This embodiment provides a colored contact lens 2-2. The composition of the lens body material of colored contact lens 2-2 is the same as that of the hydrogel composition (HEMA / MAA hydrogel) of Example 2-1, but differs in that a colored ink is introduced separately during molding. Specifically, in Example 2-2, the hydrogel composition was filled into the cavity of a polypropylene mold and cured under ultraviolet light for 12 minutes using an appropriate ink to manufacture the colored lens body. The ink may be, for example, an anti-fingerprint ink containing a silicon-carbon (Si-C) component capable of forming a coloring pattern. The coloring pattern is mainly located in the first functional group distribution layer (inner layer) of the lens, and since the ink used contains a silicon-carbon bond component, a Si-C signal may appear in the XPS carbon spectrum of the inner layer surface. However, this does not affect the formation of the two-layer functional group distribution structure of the present invention.

[0112] In Example 2-2, the lens surface was treated using the same plasma treatment conditions (nitrogen / oxygen = 6:4) as in Example 2-1, and extraction was performed in the same manner. After treatment, a second functional group distribution layer was similarly formed on the surface of the first functional group distribution layer of color lens 2-2. As shown in Figure 2-2a (comparison of inner and outer layers in XPS elemental analysis C1s scan signal), Figure 2-2b (comparison of inner and outer layers in XPS elemental analysis O1s scan signal), and Table 1, the XPS analysis results showed that the change in elemental distribution between the inner and outer layers of Example 2-2 showed a similar trend to Example 2-1. The outer layer contained even more oxygen and oxygen-containing functional groups. The presence of nitrogen-containing functional groups was also detected in the outer layer of lens 2-2. DCA dynamic contact angle measurement and AFM measurement results showed that the average contact angle hysteresis of the outer layer of lens 2-2 was approximately 2.3°, which was significantly smaller than the approximately 32.1° of the inner layer (i.e., a reduction of 92.8%). The average adhesive strength of the outer layer (less than 2nN in the test results, approximately 0.72nN to 1.67nN) was also lower than that of the inner layer (5.06nN to 6.17nN), indicating a significant improvement in surface hydrophilicity.

[0113] In particular, Color Lens 2-2 demonstrates that the two-layer surface structure of the present invention is also applicable to contact lenses containing patterns / pigments, and that it can mitigate problems such as reduced wettability associated with pattern coatings in conventional color lenses. The surface hydrophilicity and comfort of color lenses treated with the present invention are comparable to those of uncolored contact lenses.

[0114] Example 3-1 is a silicone hydrogel soft contact lens (contact lens 3-1).

[0115] This embodiment provides a silicone hydrogel soft contact lens 3-1. The lens body contains: 20 parts by weight of N-vinylpyrrolidone (NVP), 10 parts by weight of 2-hydroxyethyl methacrylate (HEMA), 15 parts by weight of N,N-dimethylacrylamide (DMA), 0.2 parts by weight of methacrylic acid (MAA), 22.5 parts by weight of 3-methacryloyloxy-2-hydroxypropoxy)propylbis(trimethylsiloxy)methylsilane (SIGMA, belonging to silicon-containing monomers), 14.2 parts by weight of siloxane macromonomer [1] (average molecular weight approximately 1500), 0.5 parts by weight of ethylene glycol dimethacrylate (EGDMA, crosslinking agent), 0.1 parts by weight of 1,3,5-trialyl isocyanurate (TAIC, radiation crosslinking aid), 1 part by weight of 2-(2-hydroxy-5-acryloyloxyethylphenyl)-2H-benzotriazole (UV absorber), 0.5 parts by weight of Irgacure 819 (photoinitiator), and dye (Reactive Blue). 19) It was prepared using a silicone hydrogel composition containing 2 parts by weight of and 14 parts by weight of 2-methyl-2-butanol (i.e., tert-amyl alcohol).

[0116] The chemical structure of the siloxane macromonomer [1] is as follows: [ka]

[0117] In the above composition, NVP and DMA provide hydrophilicity and nitrogen-containing amide functional groups, HEMA provides hydroxyl groups, and MAA provides carboxyl groups. SIGMA and siloxane macromonomers provide siloxane segments, thereby increasing the silicone content and oxygen permeability.

[0118] A silicone hydrogel composition was injected into the cavity of a polypropylene mold, and the lens body was formed by polymerization and crosslinking reactions under ultraviolet light for 12 minutes. By hydrating the lens body, a silicone hydrogel soft contact lens containing silicon-carbon bond (Si-C) structures and polar functional groups was obtained.

[0119] Here, a first functional group distribution layer (i.e., an inner layer) is formed on the outer convex surface of the lens body. By XPS, the content and composition of the surface elements of the first functional group distribution layer can be measured, and the first functional group distribution layer has a first carbon content, a first oxygen content, and a first nitrogen content.

[0120] Furthermore, the main functional groups in the first functional group distribution layer are carbonyl groups (C=O), ether groups (COC), hydroxyl groups (C-OH), and silicon-carbon bonds (Si-C). Here, C=O, COC, and C-OH originate from the polymer chains of hydrophilic monomers such as NVP, DMA, and HEMA, while Si-C originates from the siloxane segments of SIGMA and siloxane macromonomers. Regarding nitrogen-containing functional groups, the nitrogen in NVP and DMA monomers has an amide structure (belonging to an unprotonated tertiary amine). Therefore, the N1s signal in XPS mainly reflects amide nitrogen. In the first functional group distribution layer, only trace amounts of positively charged nitrogen species are detected, for example, ammonium salts (NH4 + ) is emitting a relatively weak signal.

[0121] Next, lens 3-1 was surface-treated. Specifically, lens 3-1 was surface-treated using nitrogen / oxygen (9:1) plasma, then the lens was extracted in a 50 / 50 equivalent solution of isopropyl alcohol / water at 40°C, and then the lens was stirred in deionized water at 40°C for 1 hour. Finally, it was equilibrated with borate-buffered saline (pH 7.3-7.4) and autoclaved. Through the above treatment, a second functional group distribution layer (i.e., a hydrophilic modified layer) was formed on the first functional group distribution layer, and the silicone hydrogel contact lens 3-1 of Example 3-1 was obtained.

[0122] XPS analysis allows for the measurement of the second carbon, second oxygen, and second nitrogen content of the second functional group distribution layer. The XPS analysis results of a silicone hydrogel soft contact lens (lens 3-1) are shown in Figure 3-1a (comparison of inner and outer layers in XPS elemental analysis C1s scan signal), Figure 3-1b (comparison of inner and outer layers in XPS elemental analysis O1s scan signal), and Table 1 below (differences in surface properties due to improved hydrophilicity).

[0123] XPS analysis revealed that after plasma treatment, the second carbon content composition of the second functional group distribution layer of lens 3-1 changed significantly compared to the first functional group distribution layer. The intensity of the silicon-carbon bond (Si-C) characteristic peak in the outer layer decreased significantly to about 0.6 times that of the inner layer (i.e., the Si-C content of the outer layer was 40% lower than that of the inner layer). At the same time, the proportion of carbonyl group (C=O) peaks in the C1s spectrum of the outer layer increased (ranging from about 10% to 100% higher than the inner layer), and the proportion of oxygen-containing functional group peaks such as ether group / hydroxyl group (COC / C-OH) also increased relatively. The second oxygen content increased significantly compared to the first oxygen content, and in particular, the total amount of oxygen-containing functional groups in the outer layer increased by about 100% compared to the inner layer. Regarding nitrogen elements, although the inner layer of the silicone hydrogel substrate contains amide nitrogen, after plasma nitrogen treatment of the outer layer, the N1s spectrum showed quaternary ammonium cations (NR4 + While the signal for ) appeared, this signal was hardly observed in the inner layer. This indicates that positively charged nitrogen functional groups were introduced to the surface of the outer layer by plasma treatment. Overall, the second functional group distribution layer of Example 3-1 shows a trend of increased oxygen content, increased polar groups, and decreased silicon element content compared to the first functional group distribution layer.

[0124] DCA testing revealed that the average contact angle hysteresis of the outer layer of lens 3-1 was reduced by approximately 40.7% compared to the inner layer (the hysteresis angle of the inner layer decreased to approximately 74.2°, while the hysteresis angle of the outer layer decreased to approximately 44°). AFM testing revealed that the average adhesive strength of the outer layer was significantly lower than that of the inner layer (lower adhesive strength indicates higher hydrophilicity).

[0125] Therefore, it was confirmed that after the two-layer surface structure of the present invention is formed on the silicone hydrogel lens 3-1, its hydrophobic siloxane groups are covered and replaced with a hydrophilic layer rich in oxygen and nitrogen polar groups, resulting in a significant improvement in the surface wettability of the lens.

[0126] Example 3-2 is a silicone hydrogel soft contact lens (contact lens 3-2).

[0127] This example provides another silicone hydrogel soft contact lens 3-2 to confirm the change in surface composition under different processing conditions. The silicone hydrogel composition used in the lens body of Example 3-2 contains 29.5 parts by weight of N-vinylpyrrolidone (NVP), 12 parts by weight of 2-hydroxyethyl methacrylate (HEMA), 5.8 parts by weight of N,N-dimethylacrylamide (DMA), 40 parts by weight of siloxane macromonomer [1] with an average molecular weight of 1500, 5 parts by weight of siloxane macromonomer [2] having a side chain, 1 part by weight of ethylene glycol dimethacrylate, 1 part by weight of 2-(2-hydroxy-5-methacryloyloxyethylphenyl)-2H-benzotriazole, 0.5 parts by weight of Irgacure 819, 0.2 parts by weight of Reactive Blue 19, and 5 parts by weight of tert-amyl alcohol.

[0128] The siloxane macromonomer [1] is as described in Example 3-1 above, so it will not be described again here. The chemical structure of the siloxane macromonomer [2] having a side chain is as follows.

[0129] [ka]

[0130] The silicone hydrogel composition was injected into the cavity of a polypropylene mold, and polymerization and crosslinking reactions were induced by irradiation with ultraviolet light for 12 minutes to form the lens body. By hydrating the lens body, a silicone hydrogel soft contact lens was obtained.

[0131] The lens body was surface-treated. Specifically, it was treated under plasma conditions of nitrogen / oxygen = 8:2, and the subsequent solvent extraction, pure water washing, and equilibration steps were carried out in the same manner as in Example 3-1. After treatment, a second functional group distribution layer was formed, and silicone hydrogel contact lens 3-2 was obtained.

[0132] Since Example 3-2 and Example 3-1 use similar materials and processes, XPS analysis showed that the elemental distribution characteristics of the inner and outer layers of both examples are essentially the same.

[0133] XPS analysis allows for the measurement of the second carbon content, second oxygen content, and second nitrogen content of the second functional group distribution layer. The XPS analysis results of a silicone hydrogel soft contact lens (lens 3-2) are shown in Figure 3-2a (comparison of inner and outer layers in the C1s scan signal of XPS elemental analysis), Figure 3-2b (comparison of inner and outer layers in the O1s scan signal of XPS elemental analysis), and Table 1 below (differences in surface properties due to improved hydrophilicity).

[0134] The Si-C content of the outer layer decreased by approximately 70% compared to the inner layer (see Table 1). The content of functional groups such as carbonyl groups, ether groups, and hydroxyl groups increased, the proportion of oxygen elements increased, and a signal for quaternary ammonium nitrogen appeared. These changes were similar to those in Example 3-1.

[0135] Based on the above examples, the difference in functional group / elemental distribution between the inner and outer layers of the soft contact lens of the present invention can be summarized as follows (expressed by the increase or decrease in the outer layer relative to the inner layer; see also Table 1 below).

[0136] For the hydrogel soft contact lenses (Examples 2-1 and 2-2), the oxygen content of the outer layer is significantly higher than that of the inner layer, with an increase of approximately 10% to 200%, preferably 20% to 100%, and particularly preferably 40% to 50%. The total content of oxygen-containing functional groups, such as ether groups (COC) and hydroxyl groups (C-OH), in the outer layer is approximately 10% to 80% higher than that of the inner layer. The carbonyl group (C=O) content of oxygen-containing functional groups in the outer layer is approximately 10% to 200% higher than that of the inner layer, preferably 30% to 120% higher. The nitrogen content in the outer layer is also higher than that of the inner layer, with an increase of approximately 10% to 150%, and preferably 30% to 70% higher. The primary amine / secondary amine (NH2 / NH) content of nitrogen-containing functional groups in the outer layer is approximately 10% to 150% higher than that of the inner layer, and preferably 50% to 70% higher. Of particular importance is that the outer layer is a quaternary ammonium cation (NR4 + ) It must contain a functional group.

[0137] Silicone hydrogel soft contact lenses (Examples 3-1 and 3-2): The oxygen element content of the outer layer is significantly higher than that of the inner layer, increasing by approximately 10% to 200%, preferably by 20% to 100%. The ether / hydroxyl group content of oxygen-containing functional groups in the outer layer is approximately 10% to 400% higher than that of the inner layer, preferably by 50% to 310%. The carbonyl group content of carbon-containing functional groups in the outer layer is approximately 10% to 200% higher than that of the inner layer, preferably by 40% to 90%. The proportion of carbon elements derived from silicon-carbon bonds (Si-C) in the outer layer is lower than that of the inner layer, decreasing by approximately 10% to 90%, preferably by 40% to 70% (i.e., the Si-C content of the outer layer is 0.1 to 0.9 times that of the inner layer, preferably by 0.3 to 0.6 times). Furthermore, the outer layer contains quaternary ammonium cation functional groups (NR4 +Although ) was detected, no significant signal of quaternary ammonium cations was detected in the inner layer.

[0138] The difference in composition between the inner and outer layers directly affects the surface properties of the contact lens. The outer layer contains many hydrophilic functional groups (such as hydroxyl and carbonyl groups) and incorporates positively charged quaternary ammonium groups, resulting in stronger hydrophilicity. At the same time, the outer layer has fewer hydrophobic siloxane groups, significantly reducing the hydrophobicity of the silicone hydrogel lens. These changes combined improved the wettability of the lens.

[0139] The differences in surface properties due to improved hydrophilicity are shown in Table 1 below. This table shows the total increase or decrease in each chemical state of the outer layer compared to the inner layer, as determined by XPS elemental analysis.

[0140] [Table 1]

[0141] [Clinical performance evaluation] In the clinical performance evaluation, a small-scale comparative clinical trial was conducted in Example 4 to assess the performance of the contact lenses in the examples when actually worn. Multiple contact lens samples were selected, and the hydrogel lens of Example 2-1 (referred to as lens A) and the color hydrogel lens of Example 2-2 (referred to as lens B) were used as the test group, while a commercially available Etafilcon A hydrogel lens (which does not have the surface structure of the present invention) was used as the control group. The subjects were healthy volunteers, and each subject wore the lens for 4 to 6 hours before undergoing tests including a tear film breakup time (NIKBUT) test and a wearing comfort questionnaire. The test results are shown in Table 2 below.

[0142] In the measurement of tear film break-up time (NIKBUT), an ocular surface analyzer was used to measure the non-invasive tear film break-up time after lens insertion. NIKBUT (Non-invasive Keratograph Break-Up Time) is an index that indicates the stability of tear film break-up; a higher value indicates a higher ability of the lens to retain moisture on the ocular surface.

[0143] Specifically, a non-invasive tear film breakdown time (NIKBUT) test was conducted to evaluate the effect of the lens on the stability of the tear film on the ocular surface. The test results showed that both lens A (Example 2-1) and lens B (Example 2-2) in the test group exhibited excellent tear film stability. The average NIKBUT was 16.9 seconds for lens A and 15.4 seconds for lens B. In contrast, the commercially available Etafilcon A lens in the control group had a NIKBUT of only 10.6 seconds.

[0144] According to the Dry Eye Workshop's evaluation criteria, a NIKBUT of 14 seconds or more is considered stable. 90% of the eyes tested using the lens of Example A achieved a stable evaluation, and 57% of the eyes tested using the lens of Example B met this criterion, demonstrating that the bilayer functional group distribution effectively extends tear film coverage. In contrast, only 60% of the control group's eyes fell within the stable range, and 30% fell within the abnormal range (NIKBUT ≤ 7 seconds), indicating limitations in the tear film retention ability of commercially available lenses. Overall, the lenses of the present invention, whether clear or colored, significantly improve ocular surface moisture retention, reduce dryness and visual acuity fluctuations, contribute to stability and comfort during long-term wear, and demonstrate their clinical value.

[0145] Overall, the average NIKBUT for both experimental group A lenses and experimental group B lenses was significantly longer than that of the control group, indicating that the lenses of the embodiments of the present invention are superior to conventional lenses in maintaining tear film stability.

[0146] [Table 2]

[0147] The subjective satisfaction questionnaire for wearers involves subjects evaluating the comfort of the lenses after wearing them for a certain period. Statistical results are shown in Table 3. Lens B of the present invention had the highest subjective satisfaction rating, with approximately 90% rating it as "good." Lens A received a slightly lower rating, with approximately 86% rating it as "good." In contrast, approximately 70% of the control group rating it as "good." The results are shown in Table 3.

[0148] Clearly, the lenses of the present invention (whether clear or colored) offer superior wearing comfort compared to conventional products.

[0149] [Table 3]

[0150] As described above, the clinical evaluation of Example 5 further demonstrates the effectiveness of the bilayer functional group surface structure of the present invention. Improved hydrophilicity of the lens surface leads to improved tear film stability and wearing comfort. In both objective NIKBUT tests and subjective comfort evaluations, the lenses of the present invention outperformed the conventional control group. In particular, lens B, which includes a color pattern, showed superior performance to the uncolored lens A when treated with the present invention, demonstrating that the present invention has a particularly remarkable improvement effect on colored lenses.

[0151] The information disclosed herein represents only preferred and feasible embodiments of the present invention, and the claims of the present invention are not limited thereto. Therefore, all equivalent technical modifications made using the description and drawings of the present invention are included within the scope of the claims of the present invention. [Explanation of Symbols]

[0152] E... Soft contact lenses 1...Lens body 21...First functional group distribution layer 22...Second functional group distribution layer

Claims

1. A soft contact lens that includes a lens body which is a hydrogel soft contact lens, and in which the functional group distribution of the inner layer and the outer layer are different, A first functional group distribution layer is formed on the outer convex surface of the lens body, and a second functional group distribution layer is formed on the first functional group distribution layer. The first functional group distribution layer has a first carbon content, a first oxygen content and a first nitrogen content, and the second functional group distribution layer has a second carbon content, a second oxygen content and a second nitrogen content. A soft contact lens characterized in that the second oxygen content is 10% to 200% higher than the first oxygen content, and the second nitrogen content is 10% to 150% higher than the first nitrogen content.

2. The soft contact lens according to claim 1, wherein the second oxygen content is 20% to 100% higher than the first oxygen content, and the second nitrogen content is 30% to 70% higher than the first nitrogen content.

3. The first functional group distribution layer comprises carbonyl groups (C=O), ether groups (C-O-C), hydroxyl groups (C-OH), and primary amines (NH). ２ The second functional group distribution layer has at least a carbonyl group (C=O), an ether group (C-O-C), a hydroxyl group (C-OH), and a primary amine (NH). ２ ), secondary amine (NH), ammonium ion (NH ３ ＋ ), and quaternary ammonium cations (NR ４ ＋ A soft contact lens according to claim 1, having at least one of the functional groups of ).

4. The first functional group distribution layer has at least functional groups of a carbonyl group (C=O), an ether group (C-O-C), a hydroxyl group (C-OH), a primary amine (NH ２ ), a secondary amine (NH), an ammonium ion (NH ３ ＋ ), and a quaternary ammonium cation (NR ４ ＋ ). The second functional group distribution layer has at least functional groups of a carbonyl group (C=O), an ether group (C-O-C), a hydroxyl group (C-OH), a primary amine (NH ２ ), a secondary amine (NH), an ammonium ion (NH ３ ＋ ), and a quaternary ammonium cation (NR ４ ＋ ). The soft contact lens according to claim 1.

5. The first carbon content is determined by the carbon element content of the carbon-containing functional group in the first functional group distribution layer, and the carbon-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (C-O-C), and a hydroxyl group (C-OH). The first oxygen content is determined by the oxygen element content of the oxygen-containing functional group in the first functional group distribution layer, and the oxygen-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (C-O-C), and a hydroxyl group (C-OH). The first nitrogen content is determined by the nitrogen element content of the nitrogen-containing functional group in the first functional group distribution layer, and the nitrogen-containing functional group contains a primary amine (NH ２ ), secondary amine (NH), ammonium ion (NH ３ ＋ ), and quaternary ammonium cations (NR ４ ＋ It comprises at least one functional group selected from ) The second carbon content is determined by the carbon element content of the carbon-containing functional group in the second functional group distribution layer, and the carbon-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (C-O-C), and a hydroxyl group (C-OH). The second oxygen content is determined by the oxygen element content of the oxygen-containing functional group in the second functional group distribution layer, and the oxygen-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (C-O-C), and a hydroxyl group (C-OH). The second nitrogen content is determined by the nitrogen element content of the nitrogen-containing functional group in the second functional group distribution layer, and the nitrogen-containing functional group contains primary amines (NH ２ ), secondary amine (NH), ammonium ion (NH ３ ＋ ), and quaternary ammonium cations (NR ４ ＋ A soft contact lens according to claim 4, comprising at least one functional group selected from ).

6. The soft contact lens according to claim 5, wherein the content of carbonyl groups (C=O) of carbon-containing functional groups in the second functional group distribution layer is 5% to 150% higher than the content of carbonyl groups (C=O) of carbon-containing functional groups in the first functional group distribution layer, and the content of ether groups (C-O-C) and hydroxyl groups (C-OH) of carbon-containing functional groups in the second functional group distribution layer is 5% to 120% higher than the content of ether groups (C-O-C) and hydroxyl groups (C-OH) of carbon-containing functional groups in the first functional group distribution layer.

7. The soft contact lens according to claim 6, wherein the content of carbonyl groups (C=O) of carbon-containing functional groups in the second functional group distribution layer is 20% to 130% higher than the content of carbonyl groups (C=O) of carbon-containing functional groups in the first functional group distribution layer, and the content of ether groups (C-O-C) and hydroxyl groups (C-OH) of carbon-containing functional groups in the second functional group distribution layer is 5% to 80% higher than the content of ether groups (C-O-C) and hydroxyl groups (C-OH) of carbon-containing functional groups in the first functional group distribution layer.

8. The soft contact lens according to claim 5, wherein the content of ether groups (C-O-C) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the second functional group distribution layer is 10% to 200% higher than the content of ether groups (C-O-C) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the first functional group distribution layer, and the content of carbonyl groups (C=O) of oxygen-containing functional groups in the second functional group distribution layer is 10% to 200% higher than the content of carbonyl groups (C=O) of oxygen-containing functional groups in the first functional group distribution layer.

9. The soft contact lens according to claim 8, wherein the content of ether groups (C-O-C) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the second functional group distribution layer is 10% to 60% higher than the content of ether groups (C-O-C) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the first functional group distribution layer, and the content of carbonyl groups (C=O) of oxygen-containing functional groups in the second functional group distribution layer is 10% to 50% higher than the content of carbonyl groups (C=O) of oxygen-containing functional groups in the first functional group distribution layer.

10. Primary amine (NH) nitrogen-containing functional group in the second functional group distribution layer ２ The content of primary amines (NH) and secondary amines (NH) in the nitrogen-containing functional groups in the first functional group distribution layer is ２ The content of ammonium ions (NH) of nitrogen-containing functional groups in the second functional group distribution layer is 10% to 150% higher than that of secondary amines (NH), and the content of secondary amines (NH) is 10% to 150% higher than that of secondary amines (NH). ３ ＋ ) and quaternary ammonium cation (NR ４ ＋ The content of ) is the ammonium ion (NH) of nitrogen-containing functional groups in the first functional group distribution layer. ３ ＋ ) and quaternary ammonium cation (NR ４ ＋ The soft contact lens according to claim 6, having a content of at least 10% higher than that of ).

11. Primary amine (NH) nitrogen-containing functional group in the second functional group distribution layer ２ The content of primary amines (NH) and secondary amines (NH) in the nitrogen-containing functional groups in the first functional group distribution layer is ２ The soft contact lens according to claim 10, wherein the content of ) and secondary amines (NH) is 50% to 70% higher.

12. The soft contact lens according to claim 1, wherein the adhesive force of the surface of the optical zone of the soft contact lens, as measured by an atomic force microscope (AFM) force curve test, is 2 nN or less.

13. The soft contact lens according to claim 1, wherein the contact angle hysteresis of the second functional group distribution layer, as measured by dynamic contact angle (DCA) measurement test, is reduced by 20% to 95% compared to the first functional group distribution layer.

14. The soft contact lens according to claim 1, wherein at least the second functional group distribution layer is formed by surface plasma treatment.

15. The soft contact lens according to claim 14, wherein the second functional group distribution layer is formed such that the ratio of nitrogen to oxygen used in the surface plasma treatment is 9:1 to 3:

7.

16. A soft contact lens including a lens body which is a silicone hydrogel soft contact lens, A first functional group distribution layer is formed on the outer convex surface of the lens body, and a second functional group distribution layer is formed on the first functional group distribution layer. The first functional group distribution layer has a first carbon content, a first oxygen content and a first nitrogen content, and the second functional group distribution layer has a second carbon content, a second oxygen content and a second nitrogen content. A soft contact lens characterized in that the second oxygen content is 10% to 200% higher than the first oxygen content.

17. The soft contact lens according to claim 16, wherein the second oxygen content is 20% to 110% higher than the first oxygen content.

18. The first functional group distribution layer has at least the functional groups carbonyl group (C=O), ether group (C-O-C), hydroxyl group (C-OH), and silicon-carbon bond (Si-C), and the second functional group distribution layer has carbonyl group (C=O), ether group (C-O-C), hydroxyl group (C-OH), silicon-carbon bond (Si-C), and ammonium ion (NH ３ ＋ ), and quaternary ammonium cations (NR ４ ＋ A soft contact lens according to claim 16, having at least one of the functional groups of ).

19. The first functional group distribution layer comprises carbonyl groups (C=O), ether groups (C-O-C), hydroxyl groups (C-OH), silicon-carbon bonds (Si-C), and ammonium ions (NH). ３ ＋ ), and quaternary ammonium cations (NR ４ ＋ The second functional group distribution layer has at least the following functional groups: carbonyl group (C=O), ether group (C-O-C), hydroxyl group (C-OH), silicon-carbon bond (Si-C), ammonium ion (NH ３ ＋ ), and quaternary ammonium cations (NR ４ ＋ A soft contact lens according to claim 16, having at least one of the functional groups of ).

20. The first carbon content is determined by the carbon element content of the carbon-containing functional group in the first functional group distribution layer, and the carbon-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (C-O-C), a hydroxyl group (C-OH), and a silicon-carbon bond (Si-C). The first oxygen content is determined by the oxygen element content of the oxygen-containing functional group in the first functional group distribution layer, and the oxygen-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (C-O-C), and a hydroxyl group (C-OH). The first nitrogen content is determined by the nitrogen element content of the nitrogen-containing functional group in the first functional group distribution layer, and the nitrogen-containing functional group contains ammonium ions (NH ３ ＋ ), and quaternary ammonium cations (NR ４ ＋ ) including, The second carbon content is determined by the carbon element content of the carbon-containing functional group in the second functional group distribution layer, and the carbon-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (C-O-C), a hydroxyl group (C-OH), and a silicon-carbon bond (Si-C). The second oxygen content is determined by the oxygen element content of the oxygen-containing functional group in the second functional group distribution layer, and the oxygen-containing functional group includes at least one functional group selected from a carbonyl group (C=O), an ether group (C-O-C), and a hydroxyl group (C-OH). The second nitrogen content is determined by the nitrogen element content of the nitrogen-containing functional group in the second functional group distribution layer, wherein the nitrogen-containing functional group contains ammonium ions (NH₄). ３ ＋ ), and quaternary ammonium cations (NR ４ ＋ A soft contact lens according to claim 19, including ).

21. The soft contact lens according to claim 20, wherein the content of carbonyl groups (C=O) of carbon-containing functional groups in the second functional group distribution layer is 3% to 150% higher than the content of carbonyl groups (C=O) of carbon-containing functional groups in the first functional group distribution layer, and the content of silicon-carbon bonds (Si-C) of carbon-containing functional groups in the second functional group distribution layer is 10% to 90% lower than the content of silicon-carbon bonds (Si-C) of carbon-containing functional groups in the first functional group distribution layer.

22. The soft contact lens according to claim 21, wherein the content of carbonyl groups (C=O) of carbon-containing functional groups in the second functional group distribution layer is 3% to 90% higher than the content of carbonyl groups (C=O) of carbon-containing functional groups in the first functional group distribution layer, and the content of silicon-carbon bonds (Si-C) of carbon-containing functional groups in the second functional group distribution layer is 40% to 70% lower than the content of silicon-carbon bonds (Si-C) of carbon-containing functional groups in the first functional group distribution layer.

23. The soft contact lens according to claim 21, wherein the content of ether groups (C-O-C) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the second functional group distribution layer is 10% to 400% higher than the content of ether groups (C-O-C) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the first functional group distribution layer.

24. The soft contact lens according to claim 23, wherein the content of ether groups (C-O-C) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the second functional group distribution layer is 40% to 310% higher than the content of ether groups (C-O-C) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the first functional group distribution layer.

25. Ammonium ions (NH) of nitrogen-containing functional groups in the second functional group distribution layer ３ ＋ ) and quaternary ammonium cation (NR ４ ＋ The content of ) is the ammonium ion (NH) of nitrogen-containing functional groups in the first functional group distribution layer. ３ ＋ ) and quaternary ammonium cation (NR ４ ＋ The soft contact lens according to claim 21, having a content of at least 10% higher than that of ).

26. The soft contact lens according to claim 25, wherein the adhesive force of the surface of the optical zone of the soft contact lens, as measured by an atomic force microscope (AFM) force curve test, is 2 nN or less.

27. The soft contact lens according to claim 25, wherein the contact angle hysteresis of the second functional group distribution layer, as measured by dynamic contact angle (DCA) measurement test, is reduced by 20% to 95% compared to the first functional group distribution layer.

28. The soft contact lens according to claim 16, wherein at least the second functional group distribution layer is formed by surface plasma treatment.

29. The soft contact lens according to claim 28, wherein the second functional group distribution layer is formed such that the ratio of nitrogen to oxygen used in the surface plasma treatment is 9:1 to 3:

7.

30. A step of providing a lens body which is a hydrogel soft contact lens or a silicone hydrogel soft contact lens, wherein the lens body has a first functional group distribution layer on its outer convex surface, and the first functional group distribution layer has a first carbon content, a first oxygen content and a first nitrogen content. A method for manufacturing a soft contact lens in which the functional group distributions of the inner and outer layers differ, comprising the step of forming a second functional group distribution layer on the first functional group distribution layer, wherein the second functional group distribution layer has a second carbon content, a second oxygen content, and a second nitrogen content, and the second oxygen content is 10% to 200% higher than the first oxygen content.

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