Soft contact lens having inner layer and outer layer with different functional group distributions, and manufacturing method therefor

Abstract

A soft contact lens having an inner layer and an outer layer with different functional group distributions, and a manufacturing method therefor. The soft contact lens comprises a lens body, which is a hydrogel soft lens or a silicone-hydrogel soft lens. A first functional group distribution layer is formed on an outer convex arc 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. The second oxygen content is 10% to 200% higher than the first oxygen content. The soft contact lens having an inner layer and an outer layer with different functional group distributions and the manufacturing method therefor can simultaneously achieve high oxygen permeability and good hydrophilicity, thereby enhancing comfort experience during long wearing periods.

Description

Soft contact lens with different functional group distribution in inner and outer layers and method of manufacturing the same TECHNICAL FIELD

[0001] The present disclosure relates to a soft contact lens, in particular to a soft contact lens with two layers of functional group distribution on the surface of the contact lens, and the inner and outer layers have different element or functional group content ratio. The dual-layer surface structure can improve the hydrophilicity and wearing comfort of the lens. BACKGROUND

[0002] The surface hydrophilicity of the contact lens is one of the key factors affecting the wearing comfort. The traditional hydrogel soft contact lens (such as the contact lens with HEMA base material) itself has hydrophilicity, but it may still cause lens dryness and discomfort after long-term wearing due to tear evaporation.

[0003] The silicone hydrogel soft contact lens contains siloxane components which can improve the oxygen permeability, but the siloxane groups (such as Si-C bond) make the lens surface more hydrophobic, which easily leads to poor lens surface wetting, lipid deposition and protein deposition, and further affects the wearing comfort and lens biocompatibility.

[0004] In order to improve this problem, the surface of the contact lens is often modified for hydrophilicity in the prior art. However, most surface treatments only form a single modified layer on the outermost layer of the lens, and the effect is limited and may face durability problems.

[0005] Therefore, it is still necessary to provide an improved contact lens with an innovative design in the lens surface structure to simultaneously consider high oxygen permeability and good hydrophilicity, and to improve the comfortable experience of long-term wearing. SUMMARY

[0006] The present disclosure discloses a soft contact lens, in particular to a soft contact lens with different functional group distribution in inner and outer layers. The dual-layer surface structure can improve the hydrophilicity and wearing comfort of the lens.

[0007] One embodiment of the present disclosure discloses a soft contact lens with different functional group distribution in inner and outer layers, comprising a lens body, the lens body is a hydrogel soft lens; wherein an outer convex surface of the lens body forms a first functional group distribution layer, 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, and the second nitrogen content is 10% to 150% higher than the first nitrogen content.

[0008] Optionally, 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] Optionally, the first functional group profile layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), primary amine (NH2), secondary amine (NH), ammonium (NH3 + ), and quaternary ammonium cation (NR4 + ).

[0010] Optionally, the first functional group profile layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), primary amine (NH2), secondary amine (NH), ammonium (NH3 + ), and quaternary ammonium cation (NR4 + ); and the second functional group profile layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), primary amine (NH2), secondary amine (NH), ammonium (NH3 + ), and quaternary ammonium cation (NR4 + ).

[0011] Optionally, the first carbon content is determined by the carbon element content of carbon-containing functional groups in the first functional group profile layer, the carbon-containing functional groups including at least one functional group selected from carbonyl (C=0), ether (C-O-C), and hydroxyl (C-OH).

[0012] Optionally, the first oxygen content is determined by the oxygen element content of oxygen-containing functional groups in the first functional group profile layer, the oxygen-containing functional groups including at least one functional group selected from carbonyl (C=0), ether (C-O-C), and hydroxyl (C-OH).

[0013] Optionally, the first nitrogen content is determined by the nitrogen element content of nitrogen-containing functional groups in the first functional group profile layer, the nitrogen-containing functional groups including at least one functional group selected from primary amine (NH2), secondary amine (NH), ammonium (NH3 + ), and quaternary ammonium cation (NR4 + ).

[0014] Optionally, the second carbon content is determined by the carbon element content of carbon-containing functional groups in the second functional group profile layer, the carbon-containing functional groups including at least one functional group selected from carbonyl (C=0), ether (C-O-C), and hydroxyl (C-OH).

[0015] Optionally, the second oxygen content is determined by an oxygen element content of oxygen-containing functional groups in the second functional group distribution layer, the oxygen-containing functional groups comprising at least one functional group selected from a carbonyl group (C=0), an ether group (C-0-C), and a hydroxyl group (C-OH).

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

[0017] Optionally, a content of carbonyl groups (C=0) of carbon-containing functional groups in the second functional group distribution layer is 5% to 150% higher than a content of carbonyl groups (C=0) of carbon-containing functional groups in the first functional group distribution layer, and a content of ether groups (C-0-C) and hydroxyl groups (C-OH) of carbon-containing functional groups in the second functional group distribution layer is 5% to 120% higher than a content of ether groups (C-0-C) and hydroxyl groups (C-OH) of carbon-containing functional groups in the first functional group distribution layer.

[0018] Optionally, a content of carbonyl groups (C=0) of carbon-containing functional groups in the second functional group distribution layer is 20% to 130% higher than a content of carbonyl groups (C=0) of carbon-containing functional groups in the first functional group distribution layer, and a content of ether groups (C-0-C) and hydroxyl groups (C-OH) of carbon-containing functional groups in the second functional group distribution layer is 5% to 80% higher than a content of ether groups (C-0-C) and hydroxyl groups (C-OH) of carbon-containing functional groups in the first functional group distribution layer.

[0019] Optionally, a content of ether groups (C-0-C) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the second functional group distribution layer is 10% to 200% higher than a content of ether groups (C-0-C) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the first functional group distribution layer, and a content of carbonyl groups (C=0) of oxygen-containing functional groups in the second functional group distribution layer is 10% to 200% higher than a content of carbonyl groups (C=0) of oxygen-containing functional groups in the first functional group distribution layer.

[0020] Optionally, a content of ether groups (C-0-C) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the second functional group distribution layer is 10% to 60% higher than a content of ether groups (C-0-C) and hydroxyl groups (C-OH) of oxygen-containing functional groups in the first functional group distribution layer, and a content of carbonyl groups (C=0) of oxygen-containing functional groups in the second functional group distribution layer is 10% to 50% higher than a content of carbonyl groups (C=0) of oxygen-containing functional groups in the first functional group distribution layer.

[0021] Optionally, the content of primary amines (NH2) and secondary amines (NH) of the 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 the nitrogen-containing functional groups in the first functional group distribution layer, and the content of ammonium (NH3 + ) and quaternary ammonium cations (NR4 + ) of the nitrogen-containing functional groups in the second functional group distribution layer is at least 10% higher than the content of ammonium (NH3 + ) and quaternary ammonium cations (NR4 + ) of the nitrogen-containing functional groups in the first functional group distribution layer.

[0022] Optionally, the content of primary amines (NH2) and secondary amines (NH) of the 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 the nitrogen-containing functional groups in the first functional group distribution layer.

[0023] Optionally, the adhesion force of a surface of an optical zone of the contact lens is not more than 2 nN via an atomic force microscope (AFM) force curve test.

[0024] Optionally, 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 via a dynamic contact angle (DCA) measurement test.

[0025] Optionally, at least the second functional group distribution layer is formed via a surface plasma treatment.

[0026] Optionally, the surface plasma treatment employs a ratio of nitrogen gas to oxygen gas between 9:1 and 3:7 to form the second functional group distribution layer.

[0027] Another embodiment of the present disclosure discloses a soft contact lens, comprising: a lens body, the lens body being a silicone hydrogel soft lens; wherein an outer convex arc surface of the lens body is formed with a first functional group distribution layer, 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] Optionally, the second oxygen content is 20% to 110% higher than the first oxygen content.

[0029] Optionally, the first functional group profile layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), and silicon-carbon bond (Si-C); and the second functional group profile layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), silicon-carbon bond (Si-C), ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ).

[0030] Optionally, the first functional group profile layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), silicon-carbon bond (Si-C), ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ); and the second functional group profile layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), silicon-carbon bond (Si-C), ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ).

[0031] Optionally, the first carbon content is determined by the carbon elemental content of carbon-containing functional groups in the first functional group profile layer, the carbon-containing functional groups including at least one functional group selected from carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), and silicon-carbon bond (Si-C).

[0032] Optionally, the first oxygen content is determined by the oxygen elemental content of oxygen-containing functional groups in the first functional group profile layer, and the oxygen-containing functional groups include at least one functional group selected from carbonyl (C=0), ether (C-O-C), and hydroxyl (C-OH).

[0033] Optionally, the first nitrogen content is determined by the nitrogen elemental content of nitrogen-containing functional groups in the first functional group profile layer, and the nitrogen-containing functional groups include ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ).

[0034] Optionally, the second carbon content is determined by the carbon elemental content of carbon-containing functional groups in the second functional group profile layer, and the carbon-containing functional groups include at least one functional group selected from carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), and silicon-carbon bond (Si-C).

[0035] Optionally, the second oxygen content is determined by the oxygen elemental content of oxygen-containing functional groups in the second functional group profile layer, and the oxygen-containing functional groups include at least one functional group selected from carbonyl (C=0), ether (C-O-C), and hydroxyl (C-OH).

[0036] Optionally, the second nitrogen content is determined by a nitrogen element content of nitrogen-containing functional groups in the second functional group profile layer, and the nitrogen-containing functional groups include ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ).

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

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

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

[0040] Optionally, an ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ) content of nitrogen-containing functional groups in the second functional group profile layer is at least 10% higher than an ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ) content of nitrogen-containing functional groups in the first functional group profile layer.

[0041] Optionally, an adhesion force of a surface of an optic zone of the contact lens is no more than 2 nN as tested by an atomic force microscope (AFM) force curve test.

[0042] Optionally, a contact angle hysteresis of the second functional group profile layer is 20% to 95% lower than the first functional group profile layer as tested by a dynamic contact angle (DCA) measurement test.

[0043] Optionally, at least the second functional group distribution layer is formed via a surface plasma treatment.

[0044] Optionally, the plasma treatment employs a ratio of nitrogen to oxygen between 9:1 and 3:7 to form the second functional group distribution layer.

[0045] One embodiment of the present disclosure also discloses a method of manufacturing a soft contact lens having a difference in functional group distribution between inner and outer layers, comprising: providing a lens body, the lens body being a hydrogel soft contact lens or a silicone hydrogel soft contact lens, and having a first functional group distribution layer on the outer convex arc surface thereof, wherein 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; wherein the second oxygen content is 10% to 200% higher than the first oxygen content.

[0046] In summary, the soft contact lens of the present disclosure has a first functional group distribution layer (inner layer) and a second functional group distribution layer (outer layer) formed on the arc surface of the lens. The ratio of the elements or functional groups contained in the two layers is different, and the surface of the second functional group distribution layer has higher hydrophilicity. In other words, by differentiating the design of the functional group structures on the surfaces of the inner and outer layers, the wetting performance of the lens can be effectively improved, and the wearing comfort can be improved.

[0047] For a more complete understanding of the features and technical content of the present disclosure, please refer to the following detailed description of the present disclosure and the accompanying drawings. However, such description and drawings are only used to illustrate the present disclosure, and do not limit the scope of protection of the present disclosure in any way. BRIEF DESCRIPTION OF DRAWINGS

[0048] FIG. 1 is a schematic diagram of a contact lens of the present disclosure having different functional group distribution layers.

[0049] FIG. 2-1a is a C1s X-ray photoelectron spectroscopy (XPS) graph of the lens of Example 2-1.

[0050] FIG. 2-1b is an O1s X-ray photoelectron spectroscopy (XPS) graph of the lens of Example 2-1.

[0051] FIG. 2-1c is a contact angle hysteresis analysis graph of the lens of Example 2-1.

[0052] FIG. 2-2a is a C1s X-ray photoelectron spectroscopy (XPS) graph of the lens of Example 2-2.

[0053] FIG. 2-2b is an O1s X-ray photoelectron spectroscopy (XPS) graph of the lens of Example 2-2.

[0054] Figure 2-2c is a contact angle hysteresis plot of the lens of Example 2-2.

[0055] Figure 3-1a is a C1s X-ray photoelectron spectroscopy (XPS) plot of the lens of Example 3-1.

[0056] Figure 3-1b is an O1s X-ray photoelectron spectroscopy (XPS) plot of the lens of Example 3-1.

[0057] Figure 3-1c is a contact angle hysteresis plot of the lens of Example 3-1.

[0058] Figure 3-2a is a C1s X-ray photoelectron spectroscopy (XPS) plot of the lens of Example 3-2.

[0059] Figure 3-2b is an O1s X-ray photoelectron spectroscopy (XPS) plot of the lens of Example 3-2. DETAILED DESCRIPTION

[0060] In the following description, reference is made to the accompanying drawings which form a part hereof, and in which are shown by way of illustration specific embodiments. It is also to be understood that, unless otherwise indicated, the description herein is made only for the purposes of illustrating specific embodiments and that implementations can depart from these specific embodiments.

[0061] The present disclosure relates to a soft contact lens, in particular to a soft contact lens having two layers of functional group distribution layer formed on the surface of the contact lens, and the inner and outer layers have different element or functional group content ratio. The double-layer surface structure can improve the hydrophilicity and wearing comfort of the lens.

[0062] More specifically, referring to Figure 1, the soft contact lens E of the embodiment of the present disclosure comprises a lens body 1, and a first functional group distribution layer 21 and a second functional group distribution layer 22 are sequentially formed on the outer convex surface of the lens body 1. The second functional group distribution layer 22 (outer layer) has a different element or functional group content distribution from the first functional group distribution layer 21 (inner layer) to form a soft contact lens with different functional group distribution between the inner and outer layers.

[0063] In some embodiments of the present disclosure, the outer surface of the lens body can be subjected to appropriate surface treatment (such as plasma treatment or chemical treatment) to form the second functional group distribution layer 22 on the outer surface of the first functional group distribution layer 21, so that the second functional group distribution layer 22 and the first functional group distribution layer 21 have different element content distributions.

[0064] It is to be noted that the surface treatment method for forming the inner and outer functional group distribution layer is not limited to a specific method, such as various plasma treatment, surface grafting or film plating, etc. As long as the two layers with different inner and outer component ratios can be formed on the lens surface, it belongs to the scope of the present disclosure.

[0065] Optionally, when plasma treatment is used, a nitrogen / oxygen mixed gas can be used, and the volume ratio of nitrogen to oxygen ranges from 9:1 to 3:7, so as to form a good hydrophilic layer on the lens surface.

[0066] Through a series of hydrophilic evaluation experiments (such as X-ray photoelectron spectroscopy XPS, dynamic contact angle measurement DCA, and atomic force microscope AFM adhesion test), it can be proved that the soft contact lenses provided by the embodiments of the present disclosure can significantly improve the surface hydrophilicity compared with the conventional lenses without the inner and outer functional group distribution layer, thereby improving the wearing comfort. In addition, the lenses subjected to clinical wearing test are also evaluated, including: tear film break-up time (NIKBUT) test and wearer subjective questionnaire, and the results show that the soft contact lenses with different inner and outer layer functional group distribution of the present disclosure are superior to the control group lenses in actual wearing performance.

[0067] Further, the soft contact lenses E can be divided into hydrogel soft contact lenses and silicone hydrogel soft contact lenses according to the lens material, and the detailed description is shown in the following first and second embodiments.

[0068] [Hydrogel soft contact lenses]

[0069] The first embodiment of the present disclosure provides a soft contact lens with different inner and outer layer functional group distribution, which comprises: a lens body, wherein the lens body is a hydrogel soft lens. An outer convex arc surface of the lens body forms a first functional group distribution layer, 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 has more preferred wettability, and the comfort of long-term wearing is further improved.

[0070] In some embodiments of the present disclosure, the second oxygen content can be 20% to 100% higher than the first oxygen content, and the second nitrogen content can be 30% to 70% higher than the first nitrogen content. At this time, the outer layer surface is rich in more polar functional groups, which can significantly improve the hydrophilicity of the hydrogel lens.

[0071] In some embodiments of the present disclosure, the first functional group distribution layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), primary amine (NH2), and secondary amine (NH). The second functional group distribution layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), primary amine (NH2), secondary amine (NH), ammonium (NH3 + ), and quaternary ammonium cation (NR4 + ).

[0072] By introducing more nitrogen-containing functional groups (especially ammonium / quaternary ammonium groups) in the second functional group distribution layer (outer layer), the hydrophilicity can be further enhanced, but the present disclosure is not limited thereto.

[0073] In some embodiments of the present disclosure, the first functional group distribution layer can also contain ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ), and the second functional group distribution layer also has at least these functional groups.

[0074] Further, the first carbon content is determined by the carbon element content of carbon-containing functional groups in the first functional group distribution layer, the carbon-containing functional groups including at least one functional group selected from carbonyl (C=0), ether (C-O-C), and hydroxyl (C-OH).

[0075] The first oxygen content is determined by the oxygen element content of oxygen-containing functional groups in the first functional group distribution layer, the oxygen-containing functional groups including at least one functional group selected from carbonyl (C=0), ether (C-O-C), and hydroxyl (C-OH).

[0076] The first nitrogen content is determined by the nitrogen element content of nitrogen-containing functional groups in the first functional group distribution layer, the nitrogen-containing functional groups including at least one functional group selected from primary amine (NH2), secondary amine (NH), ammonium (NH3 + ), and quaternary ammonium cation (NR4 + ).

[0077] The second carbon content is determined by the carbon element content of carbon-containing functional groups in the second functional group distribution layer, the carbon-containing functional groups including at least one functional group selected from carbonyl (C=0), ether (C-O-C), and hydroxyl (C-OH).

[0078] The second oxygen content is determined by the oxygen element content of oxygen-containing functional groups in the second functional group distribution layer, the oxygen-containing functional groups including at least one functional group selected from carbonyl (C=0), ether (C-O-C), and hydroxyl (C-OH).

[0079] The second nitrogen content is determined by the nitrogen element content of nitrogen-containing functional groups in the second functional group distribution layer, which includes at least one functional group selected from primary amine (NH2), secondary amine (NH), ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ).

[0080] In some embodiments of the present disclosure, the content of carbonyl (C=O) of carbon-containing functional groups in the second functional group distribution layer can be about 5% to 150% higher than that in the first functional group distribution layer, and the content of ether (C-O-C) and hydroxyl (C-OH) in the second functional group distribution layer can be about 5% to 120% higher than that in the first functional group distribution layer. More precisely, the increase of carbonyl (C=O) in the second functional group distribution layer can be about 20% to 130%, and the increase of ether and hydroxyl can be about 5% to 80%.

[0081] If comparing oxygen-containing functional groups, the ether and hydroxyl in the second functional group distribution layer can be about 10% to 200% higher than that in the first functional group distribution layer, and the carbonyl can be about 10% to 200% higher.

[0082] More optionally, the ether and hydroxyl of oxygen-containing functional groups in the second functional group distribution layer can be about 10% to 60% higher than that in the first functional group distribution layer, and the carbonyl can be about 10% to 50% higher.

[0083] The content of primary amine (NH2) and secondary amine (NH) of nitrogen-containing functional groups in the second functional group distribution layer can be about 10% to 150% higher than that in the first functional group distribution layer, and the content of ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ) can also be at least 10% higher, and even about 50% to 70% higher.

[0084] Through the change of the ratio of various functional groups, it can be shown that the embodiments of the present disclosure have high flexibility and application versatility in adjusting the hydrophilic properties of the outer surface of the lens, but the present disclosure is not limited thereto.

[0085] In some embodiments of the present disclosure, through the atomic force microscope (AFM) force curve test, it can be observed that the adhesion force of the optical zone of the contact lens is not greater than 2nN, showing that the outer layer is highly hydrophilic.

[0086] In the dynamic contact angle (DCA) test, the second functional group distribution layer can reduce the contact angle hysteresis by about 20% to 95% compared to the first functional group distribution layer, meaning that the second functional group distribution layer has a more preferred wetting performance. Among them, the contact angle hysteresis of the second functional group distribution layer is about not greater than 10° (the difference between the advancing angle and the receding angle), preferably between 1° and 5°.

[0087] In some embodiments of the present disclosure, at least the second functional group distribution layer can be formed via surface plasma treatment. Optionally, the ratio of nitrogen / oxygen during plasma treatment is between 9:1 and 3:7 to introduce more polar groups in the outer layer, which can significantly improve the comfort of the water contact lens, but the present disclosure is not limited thereto.

[0088] [Silicone hydrogel soft contact lens]

[0089] A second embodiment of the present disclosure provides another soft contact lens, wherein the lens body is a silicone hydrogel soft lens. Specifically, the outer convex surface of the lens body also forms a first functional group distribution layer, 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.

[0090] More particularly, the second oxygen content can be 10% to 200% higher than the first oxygen content, which can better balance high oxygen permeability and high hydrophilicity by increasing the oxygen-containing groups in the outer layer and reducing the proportion of the siloxane (Si-C) hydrophobic part. The present disclosure is not limited thereto.

[0091] In some embodiments of the present disclosure, the second oxygen content is 20% to 110% higher than the first oxygen content.

[0092] Furthermore, the first functional group distribution layer has at least the following functional groups: carbonyl (C=O), ether (C-O-C), hydroxyl (C-OH), and silicon-carbon bond (Si-C). The second functional group distribution layer has at least the following functional groups: carbonyl (C=O), ether (C-O-C), hydroxyl (C-OH), silicon-carbon bond (Si-C), and further has ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ), which can strengthen the hydrophilic characteristics of the lens outer layer, but the present disclosure is not limited thereto.

[0093] Alternatively, the first functional group distribution layer has at least the following functional groups: carbonyl (C=O), ether (C-O-C), hydroxyl (C-OH), silicon-carbon bond (Si-C), ammonium (NH3 + ), and quaternary ammonium cation (NR4 + ); and the second functional group distribution layer has at least the following functional groups: carbonyl (C=O), ether (C-O-C), hydroxyl (C-OH), silicon-carbon bond (Si-C), ammonium (NH3 + ), and quaternary ammonium cation (NR4 + ).

[0094] Further, the first carbon content is determined by the carbon element content of carbon-containing functional groups in the first 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), a hydroxyl group (C-OH), and a silicon-carbon bond (Si-C).

[0095] The first oxygen content is determined by the oxygen element content of oxygen-containing functional groups in the first 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).

[0096] The first nitrogen content is determined by the nitrogen element content of nitrogen-containing functional groups in the first functional group distribution layer, and the nitrogen-containing functional groups include an ammonium group (NH3 3+ ) and a quaternary ammonium cation (NR4 + ).

[0097] The second carbon content is determined by the carbon element content of 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), a hydroxyl group (C-OH), and a silicon-carbon bond (Si-C).

[0098] The second oxygen content is determined by the oxygen element content of 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).

[0099] The second nitrogen content is determined by the nitrogen element content of nitrogen-containing functional groups in the second functional group distribution layer, and the nitrogen-containing functional groups include an ammonium group (NH3 + ) and a quaternary ammonium cation (NR4 + ).

[0100] In some embodiments, the carbonyl group (C=O) content of the carbon-containing functional groups in the second functional group distribution layer can be increased by 3% to 150% compared to the first functional group distribution layer, and more preferably increased by 3% to 90%. The silicon-carbon bond (Si-C) content of the carbon-containing functional groups in the second functional group distribution layer can be reduced by 10% to 90% compared to the first functional group distribution layer, and more preferably reduced by 40% to 70%.

[0101] In addition, the ether group (C-O-C) and the hydroxyl group (C-OH) content of the 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 more preferably increased by 40% to 310% or the like, and the ammonium group / quaternary ammonium group content of the nitrogen-containing functional groups in the second functional group distribution layer can be increased by at least 10% compared to the first functional group distribution layer, and the present disclosure is not limited thereto.

[0102] In some embodiments of the present disclosure, the adhesion force of the surface of the optic zone of the contact lens is no more than 2 nN via an atomic force microscope (AFM) force curve test. 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 via a dynamic contact angle (DCA) measurement test. This means that the surface hydrophilicity of the silicone hydrogel lens is greatly improved. The contact angle hysteresis of the second functional group distribution layer is no more than 50° (the difference between the advancing angle and the receding angle), preferably between 40° and 50°.

[0103] In some embodiments of the present disclosure, at least the second functional group distribution layer can be formed by surface plasma treatment. Further, the plasma treatment can use a nitrogen-oxygen ratio of between 9:1 and 3:7, so that the silicone hydrogel lens retains high oxygen permeability and exhibits good hydrophilic performance. However, the present disclosure is not limited thereto.

[0104] In summary, the above first embodiment (applied to hydrogel) and the second embodiment (applied to silicone hydrogel) are specific reference embodiments of the present disclosure. By establishing the first functional group distribution layer and the second functional group distribution layer on the outer surface of the lens, and adjusting the difference in the content of the functional groups of the inner and outer layers, the wetting performance and wearing comfort of the soft contact lens can be greatly improved. However, other structures, ingredient formulations, process conditions, etc. that are not explicitly shown can still be varied and modified based on the spirit and technical means of the present disclosure, without departing from the scope of the appended claims.

[0105] [Method for manufacturing a contact lens]

[0106] Another embodiment of the present disclosure also provides a method for manufacturing a soft contact lens having a difference in the distribution of functional groups between the inner and outer layers, comprising steps S110 and S120.

[0107] Step S110 comprises providing a lens body, which is a hydrogel soft lens or a silicone hydrogel soft lens, the convex outer surface of which has a 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.

[0108] Step S120 comprises 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.

[0109] The second oxygen content is 10% to 200% higher than the first oxygen content.

[0110] In some embodiments, the step of forming the second functional group distribution layer comprises subjecting the lens body to surface plasma treatment to enrich the outer layer surface with polar functional groups or positively charged amine groups to improve the comfort of long-term wearing, but the present disclosure is not limited thereto.

[0111] In some embodiments, the surface plasma treatment is performed with a ratio of nitrogen to oxygen between 9:1 and 3:7 (preferably between 9:1 and 6:4) to introduce both oxygen-containing and nitrogen-containing functional groups on the lens surface while relatively reducing the proportion of hydrophobic functional groups, but the present disclosure is not limited thereto.

[0112] In some embodiments, the first functional group distribution layer on the lens body is formed during the lens polymerization or hydration process, and the structure of the first functional group distribution layer is further stabilized by subsequent modification steps (such as leaching, washing, or ultraviolet irradiation), but the present disclosure is not limited thereto.

[0113] [Experimental data and test results]

[0114] Example 1: To evaluate the effect of the present disclosure on the improvement of the hydrophilicity of the contact lens surface, the following will first introduce the relevant measurement method.

[0115] X-ray photoelectron spectroscopy (XPS) analysis: a surface element analysis technique that can determine the types, proportions, and bonding states of elements on the surface of a material. The analysis method includes bombarding the surface of the sample with X-rays, measuring the energy of the excited electrons escaping, and then inferring the corresponding elements and their chemical states. The embodiments of the present disclosure use XPS to measure the elemental composition of the inner layer (first functional group distribution layer) and outer layer (second functional group distribution layer) on the surface of the lens, with particular attention to the content changes of elements such as carbon (C), oxygen (O), nitrogen (N), etc. related to hydrophilicity. For example, the C1s spectrum peak analyzed by XPS can distinguish the proportions of carbon-containing functional groups such as carbonyl (C=O), ether (C-O-C), and silicon-carbon bond (Si-C). The O1s spectrum peak reflects the proportions of oxygen-containing functional groups such as carbonyl (C=O), ether (C-O-C), and hydroxyl (C-OH). The N1s spectrum peak shows the proportions of nitrogen-containing functional groups such as amino (NH2, NH) and ammonium (NH3 + + ) groups. By comparing the intensity ratios of the XPS spectrum peaks of the inner and outer layers, the content differences of the two layers in each element and functional group can be quantified.

[0116] ​Dynamic contact angle (DCA) measurement: Contact angle is an important indicator for evaluating the wettability of a material surface. Since soft contact lenses are used in aqueous environment, the dynamic contact angle of the lens surface is often measured under water using the captive bubble method. Dynamic contact angle includes advancing angle and receding angle, and the difference between the two is called contact angle hysteresis. The following examples use contact angle hysteresis as the basis for evaluating wettability, because compared to a single static contact angle, contact angle hysteresis can reduce errors caused by differences in measuring devices, environments, and human factors. In general, if both the advancing angle and the receding angle are less than 90° and the hysteresis value is close to 0, it indicates that the material surface has excellent wettability; the lower the hysteresis value, the better the surface hydrophilicity. The following examples evaluate the surface modification effect by comparing the contact angle hysteresis of the inner and outer layers of the lens. Ten test pieces are measured and analyzed to obtain the average value.

[0117] Atomic force microscope (AFM) adhesion force test: AFM has the ability to detect the properties of nanoscale surfaces and can be used to measure the adhesion force of the lens surface. During measurement, the AFM probe tip contacts the sample surface and gradually pulls away, recording the force-distance curve of the probe force changing with distance. The maximum adhesion force when the probe tip separates from the sample surface can be read from the force curve. The examples of the present disclosure select the optical zone of the lens as the test position for AFM adhesion force. As mentioned earlier, the lower the adhesion force value, the more hydrophilic the material surface. Therefore, by comparing the AFM adhesion force of the inner layer (first functional group distribution layer) and the outer layer (second functional group distribution layer), the effect of the difference in functional group distribution on hydrophilicity can be verified. Ten test pieces are measured and analyzed to obtain the average value.

[0118] Example 2-1 is a hydrogel soft contact lens (contact lens 2-1)

[0119] This example provides a hydrogel soft contact lens 2-1, the lens body of which is made of the following hydrogel composition, which contains 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 glycerol.

[0120] The above hydrogel composition is injected into the cavity of a polypropylene mold, and irradiated under ultraviolet light for 12 minutes for polymerization and crosslinking to form a lens body. After hydration, a soft hydrogel contact lens is obtained.

[0121] wherein the outer convex surface of the lens body forms a first functional group distribution layer (inner layer). The surface elemental content of the first functional group distribution layer is measurable by XPS, having a first carbon content, a first oxygen content, and a first nitrogen content. Further, the first functional group distribution layer comprises carbon- and oxygen-containing functional groups, such as carbonyl (C=0), ether (C-O-C), and hydroxyl (C-OH) groups. According to XPS analysis, nitrogen-containing groups are also detected in the first functional group distribution layer, such as ammonium (NH3 + ) or quaternary ammonium cation (NR4 + ) that can be derived from residual initiator decomposition products. Thus, the first functional group distribution layer has at least the following functional groups: carbon- and oxygen-containing functional groups, such as carbonyl, ether, and hydroxyl groups, and nitrogen-containing functional groups, such as primary amine (NH2), secondary amine (NH), ammonium (NH3 + ) or quaternary ammonium cation (NR4 + ).

[0122] Next, the lens body is surface treated to form a second functional group distribution layer (outer layer) on the first functional group distribution layer (inner layer). In this embodiment, the lens is treated in a plasma environment of nitrogen / oxygen = 6:4 at atmospheric pressure for a plasma treatment time of 0.2 seconds to 600 seconds (about 120 seconds in this embodiment) at a plasma treatment power of 300 watts to 1,200 watts (about 550 watts in this embodiment), followed by extraction in a borate buffered saline solution at pH 7.3-7.4, and then autoclaving, to obtain the hydrogel soft contact lens 2-1 of this embodiment. After this treatment, a thin layer of modified region is formed on the surface of the first functional group distribution layer, which is the second functional group distribution layer (outer layer). The second carbon content, the second oxygen content, and the second nitrogen content of the second functional group distribution layer are measurable by XPS analysis. The XPS analysis results of the hydrogel soft contact lens example 2-1 are shown in FIG. 2-1a (XPS elemental analysis C1s Scan of inner layer / outer layer signal comparison), FIG. 2-1b (XPS elemental analysis O1s Scan of inner layer / outer layer signal comparison), and Table 1 (differences in surface characteristics of improved hydrophilicity) below.

[0123] The results of the experiment show that the second functional group distribution layer (outer layer) has similar types of functional groups as the first functional group distribution layer (inner layer), but with different elemental ratios. Specifically, the second functional group distribution layer has relatively higher contents of oxygen- and carbon-containing functional groups, such as carbonyl (C=0), ether (C-O-C), and hydroxyl (C-OH) groups, as compared to the first functional group distribution layer. Meanwhile, nitrogen-containing functional groups, such as primary amine (NH2), secondary amine (NH), ammonium (NH3 + ) or quaternary ammonium cation (NR4 + ), are also observed to have increased contents in the second functional group distribution layer (as shown in Table 1 below).

[0124] As shown in FIG. 2-1c, the average contact angle hysteresis of the second functional group distribution layer (outer layer) of the lens of Example 2-1 was measured to be about 3° by DCA dynamic contact angle test, which is much lower than that of the first functional group distribution layer (inner layer) (37.3°), i.e. a decrease of about 91.9%. Similarly, AFM measurement showed that the average adhesion force of the outer layer was significantly lower than that of the inner layer (e.g. about 1.5 nN for the outer layer and about 4.5 nN for the inner layer). This result confirmed that the second functional group distribution layer formed by surface plasma treatment significantly improved the hydrophilicity of the lens surface, so that the surface wetting performance of the contact lens 2-1 was significantly better than that of the untreated surface.

[0125] Example 2-2: Hydrogel soft contact lens (color lens 2-2).

[0126] This example provides a color contact lens 2-2, which has the same material composition as the hydrogel composition of Example 2-1 (HEMA / MAA-based hydrogel), except that a color ink is additionally introduced during molding. Specifically, the color lens 2-2 is made by filling the hydrogel composition into the cavity of a polypropylene mold, and curing the color ink under UV light for 12 minutes to form the color lens body. The ink is, for example, a fingerprint-resistant ink containing silicon-carbon (Si-C) components, which can form a color ring pattern. Since the color pattern is mainly located in the first functional group distribution layer (inner layer) of the lens, and the ink used contains silicon-carbon bond components, the Si-C signal may appear in the XPS carbon spectrum of the surface of the inner layer. However, this does not affect the formation of the double-layer functional group distribution structure of the present disclosure.

[0127] Example 2-2 was then treated with the same plasma treatment conditions as Example 2-1 (nitrogen / oxygen = 6:4) on the lens surface, and extracted in the same way. After treatment, a second functional group distribution layer was also formed on the surface of the first functional group distribution layer of the color lens 2-2. As shown in FIG. 2-2a (XPS elemental analysis C1s Scan inner layer / outer layer signal comparison), FIG. 2-2b (XPS elemental analysis O1s Scan inner layer / outer layer signal comparison) and Table 1, the XPS analysis results showed that the element distribution of the inner and outer layers of Example 2-2 changed in a similar trend as Example 2-1. The outer layer was rich in more oxygen elements and oxygen-containing functional groups. At the same time, the presence of nitrogen-containing functional groups was also detected in the outer layer of the lens 2-2. DCA dynamic contact angle and AFM test results showed that the average contact angle hysteresis of the outer layer of the lens 2-2 was about 2.3°, which was significantly smaller than that of the inner layer (about 32.1°), i.e. a decrease of 92.8%. The average adhesion force of the outer layer (less than 2 nN, about 0.72 nN to 1.67 nN) was also lower than that of the inner layer (5.06 nN to 6.17 nN), and the surface hydrophilicity was significantly improved.

[0128] It is worth mentioning that the colored lens 2-2 proves that the double-layer surface structure of the present disclosure is also applicable to contact lenses containing patterns / pigments, and can improve the problem of reduced wettability caused by pattern coating of general colored lenses. The surface hydrophilicity and comfort of the colored lens treated by the present disclosure can be comparable to that of uncolored contact lenses.

[0129] Example 3-1: Silicone hydrogel soft contact lens (contact lens 3-1)

[0130] The present embodiment provides a silicone hydrogel soft contact lens 3-1. The lens body is made of the following silicone hydrogel composition, which 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) propyl bis(trimethylsiloxy) silane (SIGMA, a silicone-containing monomer), 14.2 parts by weight of siloxane macromonomer [1] (average molecular weight about 1500), 0.5 parts by weight of ethylene glycol dimethacrylate (EGDMA, crosslinking agent), 0.1 parts by weight of 1,3,5-triallylisocyanurate (TAIC, radiation crosslinking aid), 1 parts by weight of 2-(2-hydroxy-5-acryloyloxyethylphenyl)-2H-benzotriazole (UV absorber), 0.5 parts by weight of Irgacure 819 (photoinitiator), 2 parts by weight of dye (Reactive Blue 19), 14 parts by weight of 2-methyl-2-butanol (i.e. tert-amyl alcohol).

[0131] The chemical structure of the siloxane macromonomer [1] is as follows.

[0132] The NVP, DMA in the above composition provide hydrophilicity and nitrogen-containing amide functional groups, HEMA provides hydroxyl groups, and MAA provides carboxyl groups. SIGMA and siloxane macromonomer provide siloxane segments to increase the amount of silicon and oxygen permeability.

[0133] The above silicone hydrogel composition is injected into the cavity of a polypropylene mold, and irradiated under ultraviolet light for 12 minutes for polymerization and crosslinking to form the lens body. After hydration, the silicone hydrogel soft contact lens is obtained, which contains both Si-C structures and polar functional groups in the interior.

[0134] The outer convex surface of the above lens body forms a first functional group distribution layer (i.e. inner layer). The surface elemental content composition of the first functional group distribution layer can be measured by XPS, which has a first carbon content, a first oxygen content, and a first nitrogen content.

[0135] Further, the first functional group distribution layer contains major functional groups of carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), and silicon-carbon bond (Si-C). The C=0, C-O-C, and C-OH come from the polymer chains of hydrophilic monomers such as NVP, DMA, HEMA, etc., and the Si-C comes from the siloxane segments of SIGMA and siloxane macro-monomer. In terms of nitrogen-containing functional groups, the nitrogen in NVP and DMA monomers is in amide structure (belonging to tertiary amine, not protonated), thus the Nls signal in XPS mainly reflects the amide nitrogen. However, only a small amount of positive charge nitrogen species such as ammonium salt (NH4+) signal is detected in the first functional group distribution layer.

[0136] Next, the lens 3-1 is surface treated: the lens is treated by plasma with nitrogen / oxygen = 9:1, then the lens is placed in an equal volume of 50 / 50 isopropanol / water solution at 40°C for extraction, and then placed in deionized water at 40°C for stirring for 1 hour, and finally balanced in a borate buffer physiological saline at pH 7.3-7.4 and autoclaved. After the above treatment, a second functional group distribution layer (i.e., a hydrophilic modified layer) is formed on the first functional group distribution layer, thereby obtaining the silicone hydrogel contact lens 3-1 of Example 3-1.

[0137] The second carbon content, the second oxygen content, and the second nitrogen content of the second functional group distribution layer can be measured by XPS analysis. The XPS analysis results of the silicone hydrogel soft contact lens (lens 3-1) are shown in FIG. 3-1a (the inner layer / outer layer signal ratio of XPS element analysis C1s Scan), FIG. 3-1b (the inner layer / outer layer signal ratio of XPS element analysis O1s Scan), and Table 1 (differences in surface characteristics of improved hydrophilic performance) below.

[0138] XPS analysis shows that after plasma treatment, the second carbon content of the second functional group distribution layer of the lens 3-1 changes significantly compared with the first functional group distribution layer: the characteristic peak intensity of the outer layer silicon-carbon bond (Si-C) is significantly reduced to about 0.6 times that of the inner layer (i.e., the outer layer Si-C content is reduced by 40% compared with the inner layer). At the same time, the proportion of the carbonyl (C=0) peak in the C1s spectrum of the outer layer is increased (about 10% to 100% higher than that of the inner layer), and the proportion of oxygen-containing functional groups such as ether / hydroxyl (C-O-C / C-OH) is also relatively increased. The second oxygen content is significantly higher than the first oxygen content, especially the total amount of oxygen-containing functional groups in the outer layer is increased by about 100% compared with the inner layer. In terms of nitrogen element, although the inner layer of the silicone hydrogel substrate contains amide nitrogen, after plasma treatment with nitrogen-containing gas, quaternary ammonium cation (NR4 +) signal, and the inner layer is substantially free of this signal. This indicates that the plasma treatment introduced positively charged nitrogen functional groups to the outer layer surface. Overall, the second functional group distribution layer of Example 3-1 exhibited a trend of increased oxygen content, increased polar groups, and decreased silicon element content relative to the first functional group distribution layer.

[0139] The average contact angle hysteresis of the outer layer of lens 3-1 was reduced by about 40.7% relative to the inner layer (about 74.2° for the inner layer and about 44° for the outer layer) as tested by DCA. AFM testing showed that the average adhesion force value of the outer layer was significantly lower than that of the inner layer (lower adhesion force indicates higher hydrophilicity).

[0140] Thus, it can be confirmed that after forming the double-layer surface structure of the present disclosure, the hydrophobic siloxane groups of the silicone hydrogel lens 3-1 are covered, and instead, a hydrophilic layer rich in oxygen, nitrogen polar groups, significantly improves the surface wettability of the lens.

[0141] Example 3-2: Silicone hydrogel soft contact lens (contact lens 3-2)

[0142] This example provides another set of silicone hydrogel soft contact lenses 3-2 to verify the changes in surface composition under different treatment conditions. The silicone hydrogel composition used for the lens body of Example 3-2 includes 29.5 parts by weight of N-vinyl pyrrolidone (NVP), 12 parts by weight of 2-hydroxyethyl methacrylate (HEMA), 5.8 parts by weight of N,N-dimethyl acrylamide (DMA), 40 parts by weight of a siloxane macromonomer [1] having an average molecular weight of 1500, 5 parts by weight of a 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 t-amyl alcohol.

[0143] The siloxane macromonomer [1] is as described above in Example 3-1 and is not repeated here. The chemical structure of the siloxane macromonomer [2] having a side chain is as follows.

[0144] The above silicone hydrogel composition was injected into the cavity of a polypropylene mold, and polymerization and crosslinking were performed under ultraviolet light for 12 minutes to form a lens body. After hydration, a silicone hydrogel soft contact lens was obtained.

[0145] The lens body was surface treated using a nitrogen / oxygen = 8:2 plasma condition, and the subsequent solvent extraction, pure water washing, and equilibration steps were the same as in Example 3-1. After treatment, a second functional group distribution layer was formed, and a silicone hydrogel contact lens 3-2 was obtained.

[0146] Since Example 3-2 is similar to Example 3-1 in materials and processing, the element distribution characteristics of the inner and outer layers of both are basically consistent as determined by XPS analysis.

[0147] The second carbon content, the second oxygen content, and the second nitrogen content of the second functional group distribution layer can be determined by XPS analysis. The XPS analysis results of the silicone hydrogel soft contact lens (lens 3-2) are shown in FIG. 3-2a (XPS element analysis C1s Scan inner-outer layer signal ratio), FIG. 3-2b (XPS element analysis O1s Scan inner-outer layer signal ratio), and Table 1 below (differences in surface characteristics for improved hydrophilicity).

[0148] The Si-C content of the outer layer relative to the inner layer decreases by about 70% (as shown in Table 1), the content of functional groups such as carbonyl, ether, and hydroxyl groups increases, the proportion of oxygen elements increases, and quaternary ammonium salt nitrogen signals appear. These changes are similar to those of Example 3-1.

[0149] In summary of the above examples, the differences in the functional group / element distribution between the inner and outer layers of the soft contact lenses of the present disclosure can be summarized as follows (expressed as the increase or decrease in the outer layer relative to the inner layer, and please refer to Table 1 below).

[0150] The silicone hydrogel soft contact lens (Examples 2-1, 2-2): the oxygen element content of the outer layer is significantly higher than that of the inner layer, with an increase of about 10% to 200%, preferably an increase of 20% to 100%, and particularly preferably an increase of 40% to 50%; wherein the total content of the ether (C-O-C) and hydroxyl (C-OH) oxygen-containing functional groups in the outer layer is about 10% to 80% higher than that in the inner layer; the content of the carbonyl (C=O) oxygen-containing functional group in the outer layer is about 10% to 200% higher than that in the inner layer, preferably about 30% to 120% higher. The nitrogen element content of the outer layer is also higher than that of the inner layer, with an increase of about 10% to 150%, preferably an increase of 30% to 70%; wherein the content of the primary / secondary amine (NH2 / NH) nitrogen-containing functional group in the outer layer is about 10% to 150% higher than that in the inner layer, preferably about 50% to 70% higher. More importantly, the outer layer appears quaternary ammonium cation (NR4 + ) functional groups.

[0151] Silicone hydrogel soft contact lenses (Example 3-1, 3-2): The outer layer has significantly higher oxygen element content than the inner layer, increased by about 10% to 200%, preferably increased by 20% to 100%, and the ether group / hydroxyl group content of the oxygen-containing functional groups in the outer layer is about 10% to 400% higher than that in the inner layer, preferably 50% to 310% higher, and the carbonyl group content of the carbon-containing functional groups in the outer layer is about 10% to 200% higher than that in the inner layer, preferably 40% to 90% higher. In the carbon element composition of the outer layer, the proportion from the silicon-carbon bond (Si-C) is lower than that in the inner layer, reduced by about 10% to 90%, preferably reduced by 40% to 70% (i.e. the Si-C content in the outer layer is 0.1 to 0.9 times, preferably 0.3 to 0.6 times, of that in the inner layer). In addition, the outer layer detects quaternary ammonium cation functional groups (NR4 + ), while the inner layer does not detect significant quaternary ammonium cation signals.

[0152] The above differences in the composition of the inner and outer layers directly lead to changes in the surface properties of the contact lens: due to the enrichment of more hydrophilic functional groups (such as hydroxyl groups, carbonyl groups, etc.) in the outer layer and the introduction of positively charged quaternary ammonium groups, the outer layer has stronger hydrophilicity; at the same time, the relative reduction of hydrophobic siloxane groups in the outer layer greatly reduces the hydrophobicity of the silicone hydrogel lens. These changes comprehensively improve the wetting performance of the lens.

[0153] The surface property differences of the improved hydrophilic performance are shown in the following Table 1, which is a total table of the increase / decrease multiples of each state of the outer layer compared to the inner layer by XPS element analysis.

[0154] [Table 1]

[0155] [Clinical performance evaluation]

[0156] The clinical performance evaluation is to evaluate the performance of the contact lenses of the examples in actual wearing. Example 4 carries out a small-scale clinical wearing comparison test. Several contact lens samples are selected, among which the silicone hydrogel lenses of the examples (Example 2-1, referred to as A lenses) and the colored silicone hydrogel lenses (Example 2-2, referred to as B lenses) are used as the test group; and the commercially available Etafilcon A silicone hydrogel lenses (without the surface structure of the present disclosure) are used as the control group. The subjects are healthy volunteers, each of whom wears one of the lenses on the eye for 4 to 6 hours and then receives detection, including tear film break-up time (NIKBUT) test and wearing feeling questionnaire. The test results are as shown in Table 2.

[0157] Tear film break-up time (NIKBUT) test: a non-invasive tear film break-up time after wearing the lens is measured using an ocular surface analyzer. NIKBUT (Non-invasive Keratograph Break-Up Time) is an index representing the stability of tear film break-up, and the higher the value, the better the lens can maintain the wet state of the ocular surface.

[0158] More specifically, to evaluate the effect of the lenses on the ocular tear film stability, a non-invasive tear film break-up time (NIKBUT) test was performed. The results showed that both the A lens (Example 2-1) and the B lens (Example 2-2) exhibited excellent tear film stability performance. The average NIKBUT of the A lens was 16.9 seconds, and that of the B lens was 15.4 seconds, while that of the control Etafilcon A lens was only 10.6 seconds.

[0159] According to the Dry Eye Workshop grading criteria, NIKBUT≥14 seconds can be considered as stable tear film. 90% of the test eyes of the A lens of the present disclosure reached the stable level, and 57% of the B lens reached the stable level, showing that the double-layer functional group distribution layer can effectively prolong the tear film coverage time. In comparison, only 60% of the control group belonged to the stable interval, and 30% of the test eyes belonged to the abnormal range (NIKBUT≤7 seconds), which showed that the commercially available lens had limited tear film maintenance. Overall, the lenses of the present disclosure, whether transparent or colored versions, can significantly improve the ocular surface wetness, reduce dryness and visual fluctuations, help stability and comfort for long-term wear, and have clinical application value.

[0160] Overall, the average NIKBUT of the A lens and the B lens of the test group was significantly longer than that of the control group, indicating that the lenses of the present disclosure were superior to traditional lenses in maintaining tear film stability.

[0161] [Table 2] Comparison results of NIKBUT test of lenses in each group

[0162] Wearer subjective questionnaire: subjects rated the comfort of the lenses after wearing for a period of time. The statistical results are shown in Table 1, and the subjective satisfaction of the B lens of the present disclosure is the highest, about 90% of the evaluation is good; the A lens is slightly less, about 86% of the good rate; the control group is about 70%. The results are shown in Table 3.

[0163] Obviously, the lenses of the present disclosure (whether transparent or colored) are significantly superior to traditional products in terms of wearing comfort.

[0164] [Table 3]. Wearer subjective satisfaction questionnaire results (good evaluation ratio)

[0165] In summary, the clinical evaluation of Example 5 further proves the effect of the double-layer functional group surface structure of the present disclosure: the improvement of the hydrophilicity of the lens surface brings about the improvement of the tear film stability and the improvement of the wearing comfort. In the objective test of NIKBUT and the subjective comfort evaluation, the lenses of the present disclosure are superior to the traditional control group, especially the B lens containing color patterns, which performs even better than the uncolored A lens after being treated by the present disclosure, showing that the present disclosure has a particularly significant improvement effect on color lenses.

[0166] The above description is only the preferred and feasible embodiments of the present disclosure, and does not limit the patent scope of the present disclosure, so that equivalent technical changes made by applying the content of the specification and drawings of the present disclosure are included in the protection scope of the present disclosure. The above disclosed content is only the preferred and feasible embodiments of the present disclosure, and does not limit the patent scope of the present disclosure, so that equivalent technical changes made by applying the content of the specification and drawings of the present disclosure are included in the patent scope of the present disclosure.

Claims

1. A soft contact lens having a difference in the distribution of functional groups between the inner and outer layers, wherein, The soft contact lens with the difference in functional group distribution between the inner and outer layers comprises: a lens body, which is a hydrogel soft lens; wherein an outer convex arc surface of the lens body is formed with a first functional group distribution layer, and the first functional group distribution layer is formed with a second 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, and the second nitrogen content is 10% to 150% higher than the first nitrogen content.

2. The soft contact lens of 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 soft contact lens of claim 1, wherein, The first functional group distribution layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), primary amine (NH2), and secondary amine (NH); and the second functional group distribution layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), primary amine (NH2), secondary amine (NH), ammonium (NH3 + ), and quaternary ammonium cation (NR4 + ).

4. The soft contact lens of claim 1, wherein, The first functional group distribution layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), primary amine (NH2), secondary amine (NH), ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ); and the second functional group distribution layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), primary amine (NH2), secondary amine (NH), ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ).

5. The soft contact lens of claim 4, wherein, The first carbon content is determined by the carbon element content of carbon-containing functional groups in the first functional group distribution layer, the carbon-containing functional groups including at least one functional group selected from carbonyl (C=O), ether (C-O-C) and hydroxyl (C-OH); wherein the first oxygen content is determined by the oxygen element content of oxygen-containing functional groups in the first functional group distribution layer, the oxygen-containing functional groups including at least one functional group selected from carbonyl (C=O), ether (C-O-C) and hydroxyl (C-OH); wherein the first nitrogen content is determined by the nitrogen element content of nitrogen-containing functional groups in the first functional group distribution layer, the nitrogen-containing functional groups including at least one functional group selected from a primary amine (NH2), a secondary amine (NH), an ammonium cation (NH3 + ), and a quaternary ammonium cation (NR4 + ). wherein the first nitrogen content is determined by the nitrogen element content of nitrogen-containing functional groups in the first functional group distribution layer, the nitrogen-containing functional groups including at least one functional group selected from a primary amine (NH2), a secondary amine (NH), an ammonium cation (NH3 + ), and a quaternary ammonium cation (NR4 + ). wherein the second carbon content is determined by the carbon element content of carbon-containing functional groups in the second functional group distribution layer, the carbon-containing functional groups including at least one functional group selected from carbonyl (C=O), ether (C-O-C) and hydroxyl (C-OH); wherein the second oxygen content is determined by the oxygen element content of oxygen-containing functional groups in the second functional group distribution layer, the oxygen-containing functional groups including at least one functional group selected from carbonyl (C=O), ether (C-O-C) and hydroxyl (C-OH); wherein the second nitrogen content is determined by the nitrogen element content of nitrogen-containing functional groups in the second functional group distribution layer, the nitrogen-containing functional groups including at least one functional group selected from a primary amine (NH2), a secondary amine (NH), an ammonium cation (NH3 + ), and a quaternary ammonium cation (NR4 + ). + ) and a quaternary ammonium cation (NR4 + ).

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

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

8. The soft contact lens of 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 of 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. The soft contact lens of claim 6, wherein, 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 (NH3 + ) and quaternary ammonium cations (NR4 + ) of nitrogen-containing functional groups in the second functional group distribution layer is at least 10% higher than the content of ammonium (NH3 + ) and quaternary ammonium cations (NR4 + ) of nitrogen-containing functional groups in the first functional group distribution layer.

11. The soft contact lens of claim 10, wherein, 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.

12. The soft contact lens of claim 1, wherein, An adhesion force of a surface of an optical zone of the contact lens is not greater than 2nN via an atomic force microscope (AFM) force curve test.

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

14. The soft contact lens of claim 1, wherein, At least the second functional group distribution layer is formed via a surface plasma treatment.

15. The soft contact lens of claim 14, wherein, A ratio of nitrogen gas to oxygen gas employed in the surface plasma treatment is between 9:1 and 3:7 to form the second functional group distribution layer.

16. A soft contact lens, wherein, The soft contact lens comprises: A lens body, the lens body being a silicone hydrogel soft lens; wherein an outer convex arc surface of the lens body is formed with a first functional group distribution layer, and the first functional group distribution layer is formed with a second 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.

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

18. The soft contact lens of claim 16, wherein, The first functional group distribution layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), and silicon-carbon bond (Si-C); and the second functional group distribution layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), silicon-carbon bond (Si-C), ammonium (NH3 + ), and quaternary ammonium cation (NR4 + ).

19. The soft contact lens of claim 16, wherein, The first functional group distribution layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), silicon-carbon bond (Si-C), ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ); and the second functional group distribution layer has at least the following functional groups: carbonyl (C=0), ether (C-O-C), hydroxyl (C-OH), silicon-carbon bond (Si-C), ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ).

20. The soft contact lens of claim 19, wherein, The first carbon content is determined by a carbon element content of carbon-containing functional groups in the first functional group distribution layer, the carbon-containing functional groups including 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); wherein the first oxygen content is determined by an oxygen element content of oxygen-containing functional groups in the first 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); wherein the first nitrogen content is determined by the nitrogen element content of nitrogen-containing functional groups in the first functional group distribution layer, and the nitrogen-containing functional groups include ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ). wherein the second carbon content is determined by a carbon element content of 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), a hydroxyl group (C-OH), and a silicon-carbon bond (Si-C); wherein the second oxygen content is determined by an oxygen element content of 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); wherein the second nitrogen content is determined by the nitrogen element content of nitrogen-containing functional groups in the second functional group distribution layer, and the nitrogen-containing functional groups include ammonium (NH3 + ) and quaternary ammonium cation (NR4 + ).

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

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

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

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

25. The soft contact lens of claim 21, wherein, the ammonium content of the nitrogen-containing functional groups in the second functional group distribution layer (NH3 + ) to the quaternary ammonium cation (NR4 + ) is at least 10% higher than the ammonium content of the nitrogen-containing functional groups in the first functional group distribution layer (NH3 + ) to the quaternary ammonium cation (NR4 + ).

26. The soft contact lens of claim 25, wherein, An adhesion force of a surface of an optic zone of the contact lens is no more than 2 nN as tested by an atomic force microscope (AFM) force curve test.

27. The soft contact lens of claim 25, wherein, A contact angle hysteresis of the second functional group distribution layer is 20% to 95% lower than that of the first functional group distribution layer as tested by a dynamic contact angle (DCA) measurement test.

28. The soft contact lens of claim 16, wherein, At least the second functional group distribution layer is formed by a surface plasma treatment.

29. The soft contact lens of claim 28, wherein, The plasma treatment employs a ratio of nitrogen gas to oxygen gas between 9:1 and 3:7 to form the second functional group distribution layer.

30. A method of making a soft contact lens having a difference in the distribution of functional groups between the inner and outer layers, wherein, The method for manufacturing the soft contact lens with the difference in the functional group distribution between the inner layer and the outer layer comprises: providing a lens body, the lens body being a hydrogel soft contact lens or a silicone hydrogel soft contact lens, and an outer convex surface of the lens body having a 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 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 wherein the second oxygen content is 10% to 200% higher than the first oxygen content.

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