A high-strength and slippery PVA hydrogel, its preparation method and application

Abstract

The present invention relates to the technical field of hydrogels, and particularly to a high-strength and wet-slippery PVA hydrogel, a preparation method thereof and an application thereof. The preparation method of the high-strength and wet-slippery PVA hydrogel provided by the present invention includes: performing water evaporation treatment on an aqueous solution of polyvinyl alcohol to obtain a PVA dry gel; performing salting-out treatment on the PVA dry gel in a sodium salt solution and then performing water balance to obtain the high-strength and wet-slippery PVA hydrogel. The high-strength and wet-slippery PVA hydrogel obtained by the preparation method of the present invention has both high light transmittance, hydrophilicity and lubricity, good biocompatibility and adjustable mechanical properties. At the same time, the present invention also provides the application of the high-strength and wet-slippery PVA hydrogel in contact lenses. The contact lenses made therefrom have high transparency, good oxygen permeability and excellent smoothness, and completely solve the problem of poor hydrophilicity existing on the surface of traditional silicone hydrogel contact lenses, thereby improving the requirement for the wearing comfort of contact lenses.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogels, and particularly to a high-strength and wet-slippery PVA hydrogel, a preparation method thereof and an application thereof. Background Art

[0002] At present, the number of people wearing glasses is increasing. Among them, contact lenses have been gradually accepted and favored by more and more people due to their high water content, softness, comfortable and convenient wearing, etc. Most of the materials used for making traditional soft contact lenses are divided into two types: one is a silicone hydrogel formed by polymerization of silicone monomers and hydrophilic monomers; the second is a hydrogel copolymerized from hydrophilic monomers such as 2-hydroxyethyl methacrylate (HEMA), N,N-dimethylacrylamide (DMA), N-vinylpyrrolidone (NVP), etc. Among them, although silicone hydrogel contact lenses have high oxygen permeability, silicone hydrogel, as a hydrophobic material, has very poor surface wettability and lubricity of the prepared contact lenses, and long-term wearing is likely to cause visual blurring, and in severe cases, discomfort symptoms such as dry eyes and eye inflammation will occur. In order to improve the wearing comfort of silicone hydrogel contact lenses, generally, surface modification needs to be carried out on silicone hydrogel contact lenses. The most common strategy is to add internal wetting agents or introduce a large number of hydrophilic groups into silicone monomers. However, introducing too much hydrophilic polymer into silicone hydrogel will lead to poor light transmittance and decreased mechanical properties due to the difference in isotropy. Although the second type of hydrogel has excellent softness and high water content and other characteristics, which can greatly improve the wearing comfort to a certain extent; the common problem of hydrogel contact lenses is that they can only transmit oxygen through the water molecules swollen in them, resulting in low oxygen permeability of the hydrogel contact lenses, and during long-term wearing, the water in the contact lenses will volatilize, causing the contact lenses to absorb tears from the human eye to maintain the original water content. Therefore, long-term wearing of such hydrogel contact lenses will cause symptoms such as corneal anoxic edema, eye inflammation, conjunctival congestion, dry eyes and neovascularization.

[0003] Therefore, for an excellent hydrogel contact lens material, it should have good light transmittance, surface wettability, biocompatibility, high oxygen permeability, and appropriate mechanical properties. Among them, oxygen permeability and surface wettability are the main factors determining the wearing time. In addition, the water content of the hydrogel contact lens also affects its oxygen permeability characteristics. Generally speaking, increasing its water content can significantly improve the oxygen permeability coefficient of the hydrogel contact lens, and the obtained hydrogel contact lens is also relatively soft. However, the higher the water content, the worse the mechanical properties of the hydrogel contact lens and the faster the surface water loss will be. Therefore, developing a contact lens hydrogel material with high oxygen permeability, good light transmittance, high hydrophilicity and lubricity, biocompatibility, and appropriate mechanical properties is one of the technical problems that need to be solved urgently by those skilled in the art. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-strength and wet-slippery PVA hydrogel, its preparation method and application. The high-strength and wet-slippery PVA hydrogel prepared by the preparation method of the present invention has high oxygen permeability, good light transmittance, high hydrophilicity and lubricity, biocompatibility, and appropriate mechanical properties.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0006] The present invention provides a preparation method of a high-strength and wet-slippery PVA hydrogel, comprising the following steps:

[0007] Perform water evaporation treatment on the polyvinyl alcohol aqueous solution to obtain a PVA dry gel;

[0008] After subjecting the PVA dry gel to salting-out treatment in a sodium salt solution, perform water balance to obtain the high-strength and wet-slippery PVA hydrogel.

[0009] Preferably, the molecular weight of the polyvinyl alcohol in the polyvinyl alcohol aqueous solution is 77,000 - 14,6000.

[0010] Preferably, the mass concentration of the polyvinyl alcohol aqueous solution is 2.5 - 15.0%.

[0011] Preferably, the sodium salt solution includes one or more of sodium chloride solution, sodium carbonate solution, sodium bicarbonate solution, disodium hydrogen phosphate solution, sodium dihydrogen phosphate solution, and trisodium citrate solution.

[0012] Preferably, the concentration of the sodium salt solution is 0.3 - 1.5 mol / L.

[0013] Preferably, the time of the salting-out treatment is 1 - 96 h.

[0014] Preferably, the time of the water balance is 24 - 96 h.

[0015] The present invention also provides a high-strength and wet-sliding PVA hydrogel prepared by the preparation method described in the above technical solution.

[0016] The present invention also provides an application of the high-strength and wet-sliding PVA hydrogel described in the above technical solution in the preparation of contact lenses, and the high-strength and wet-sliding PVA hydrogel is a high-strength and wet-sliding PVA hydrogel having the shape of a contact lens.

[0017] Preferably, the application is: sterilizing the high-strength and wet-sliding PVA hydrogel.

[0018] The present invention provides a preparation method of a high-strength and wet-sliding PVA hydrogel, comprising the following steps: performing water evaporation treatment on an aqueous solution of polyvinyl alcohol to obtain a PVA dry gel; performing salting-out treatment on the PVA dry gel in a sodium salt solution, and then performing water balance to obtain the high-strength and wet-sliding PVA hydrogel. The present invention utilizes water evaporation treatment to evaporate water molecules in the PVA solution to obtain a PVA dry gel, and then subjects the PVA dry gel to salting-out treatment to induce aggregation and crystallization of PVA molecular chains through phase separation, thereby achieving a PVA hydrogel with excellent mechanical properties. Finally, by performing water balance treatment to wash the residual salt solution, a hydrogel with good oxygen permeability, mechanical properties, hydrophilic properties, lubricating properties, light transmittance and biocompatibility can be obtained, thus completely avoiding the adverse symptoms caused by traditional hydrogel-prepared contact lenses when worn and better improving the comfort of wearing contact lenses.

[0019] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0020] 1. The high-strength and wet-sliding hydrogel prepared by the present invention has adjustable mechanical properties, enhancing the tensile properties and flexural properties of the hydrogel while reducing the hardness, and at the same time maintaining the flexibility of the hydrogel;

[0021] 2. The arrangement of hydrophilic groups on the surface of the high-strength and wet-sliding hydrogel prepared by the present invention is more uniform, making it have better surface hydrophilicity and lubricity;

[0022] 3. The high-strength and wet-sliding hydrogel prepared by the present invention has high light transmittance, improving the optical properties of traditional gel materials;

[0023] 4. Compared with the silicone hydrogel used in existing contact lenses, the high-strength and wet-sliding hydrogel prepared by the present invention has good wetting properties without any surface treatment, completely solving the problem of poor hydrophilicity on the surface of traditional silicone hydrogels;

[0024] 5. The high-strength and wet-slippery hydrogel prepared by the present invention has high oxygen permeability and good biocompatibility. When used in contact lenses, it provides high wearing comfort and better health protection for users. Description of the Drawings

[0025] Figure 1 It is a schematic process diagram for preparing the high-strength and wet-slippery PVA hydrogel of the present invention;

[0026] Figure 2 It is a schematic structural diagram of a mold for forming contact lenses; 1 - female mold, 2 - male mold, 3 - water evaporation channel;

[0027] Figure 3 It is the wettability of the high-strength and wet-slippery PVA hydrogel described in Example 4;

[0028] Figure 4 It is the water content of the high-strength and wet-slippery PVA hydrogels described in Examples 1 - 6;

[0029] Figure 5 It is the light transmittance of the high-strength and wet-slippery PVA hydrogels described in Examples 1 - 6;

[0030] Figure 6 It is the lubrication performance of the high-strength and wet-slippery PVA hydrogel described in Example 4 in pure water, PBS buffer solution, PVA eye drops and contact lens multi-functional care solution;

[0031] Figure 7 It is a physical picture of the high-strength and wet-slippery PVA hydrogel contact lens sample described in Example 7. Detailed Embodiments

[0032] As Figure 1 shown, the present invention provides a method for preparing a high-strength and wet-slippery PVA hydrogel, comprising the following steps:

[0033] Performing water evaporation treatment on an aqueous solution of polyvinyl alcohol to obtain a PVA dry gel;

[0034] Subjecting the PVA dry gel to salting-out treatment in a sodium salt solution and then performing water balance to obtain the high-strength and wet-slippery PVA hydrogel.

[0035] In the present invention, unless otherwise specified, all preparation raw materials are commercially available products well-known to those skilled in the art.

[0036] The present invention performs water evaporation treatment on an aqueous solution of polyvinyl alcohol to obtain a PVA dry gel.

[0037] In the present invention, the molecular weight of polyvinyl alcohol in the aqueous solution of polyvinyl alcohol is preferably 77,000 - 146,000, more preferably 89,000 - 146,000, and most preferably 89,000 - 98,000.

[0038] In the present invention, the mass concentration of the polyvinyl alcohol aqueous solution is preferably 2.5 to 15.0%, more preferably 5.0 to 12.5%, and most preferably 7.5 to 10.0%.

[0039] In the present invention, the water evaporation treatment is preferably carried out after placing the polyvinyl alcohol aqueous solution in a forming mold. The present invention does not have any special limitation on the forming mold, and a forming mold with a required shape can be selected according to actual needs. In the present invention, when the high-strength and wet-slippery PVA hydrogel is used for preparing contact lenses, the forming mold is preferably a mold for forming contact lenses (as Figure 2 shown).

[0040] In the present invention, the water evaporation treatment is preferably carried out under conditions of constant temperature and humidity; the humidity is preferably 30%, and the temperature is preferably 25°C. In a specific embodiment of the present invention, the water evaporation treatment is specifically carried out in a constant temperature and humidity chamber.

[0041] In the present invention, the temperature of the water evaporation treatment is preferably 25 to 60°C, more preferably 30 to 55°C, and most preferably 35 to 45°C; the time is preferably 24 to 96 h, more preferably 36 to 84 h, and most preferably 48 to 72 h.

[0042] In the present invention, the water content of the PVA dry gel is preferably 3 to 5 wt%, more preferably 4 to 5 wt%.

[0043] After obtaining the PVA dry gel, in the present invention, the PVA dry gel is subjected to salting-out treatment in a sodium salt solution and then subjected to water balance to obtain the high-strength and wet-slippery PVA hydrogel.

[0044] In the present invention, the sodium salt solution includes one or more of sodium chloride solution, sodium carbonate solution, sodium bicarbonate solution, disodium hydrogen phosphate solution, sodium dihydrogen phosphate solution, and trisodium citrate solution; when the sodium salt solution is two or more of the above specific selections, the present invention does not have any special limitation on the ratio of the above specific substances, and they can be mixed in any ratio.

[0045] In the present invention, the concentration of the sodium salt solution is preferably 0.3 to 1.5 mol / L, more preferably 0.6 to 1.2 mol / L, and most preferably 0.6 to 0.9 mol / L.

[0046] In the present invention, the temperature of the salting-out treatment is preferably 25 to 35°C, the time is preferably 1 to 96 h, more preferably 12 to 48 h, and most preferably 24 to 48 h.

[0047] In the present invention, during the salting-out treatment process, strong aggregation and crystallization of PVA polymer chains are strongly induced through phase separation.

[0048] After the salting-out treatment is completed, the present invention preferably further includes a washing process; the detergent used for washing is preferably deionized water; the present invention does not have any special limitation on the number of times of washing, and the number of times well-known to those skilled in the art can be adopted as long as it can ensure complete removal of the residual sodium salt solution on the surface of the hydrogel.

[0049] In the present invention, the water balance is preferably carried out by placing the high-strength hydrogel obtained by the salting-out treatment in water.

[0050] In the present invention, the temperature of the water balance is preferably 25-35 °C; the time of the water balance is preferably 24-96 h, more preferably 24-72 h, and most preferably 24-48 h.

[0051] In the present invention, the purpose of the water balance is to further wash and remove the residual sodium salt that did not participate in the salting-out in the hydrogel.

[0052] The present invention also provides a high-strength and wet-slippery PVA hydrogel prepared by the preparation method described in the above technical solution.

[0053] In the present invention, due to the salting-out effect, the high-strength and wet-slippery PVA hydrogel undergoes strong phase separation to induce strong aggregation and crystallization of PVA polymer chains, forming a dense hydrogen bond network between the PVA polymer chains; the high-strength and wet-slippery PVA hydrogel has high oxygen permeability, good light transmittance, high hydrophilicity, lubricity and biocompatibility.

[0054] The present invention also provides the application of the high-strength and wet-slippery PVA hydrogel described in the above technical solution in the preparation of contact lenses, and the high-strength and wet-slippery PVA hydrogel is a high-strength and wet-slippery PVA hydrogel having the shape of a contact lens.

[0055] In the present invention, the preparation process of the high-strength and wet-slippery PVA hydrogel having the shape of a contact lens preferably refers to the preparation process of the above high-strength and wet-slippery PVA hydrogel, and the difference is only that when preparing the PVA dry gel, the PVA aqueous solution is placed in a concave die mold (such as Figure 2 shown), and the convex film and the concave die are pressed and fixed, and then placed in a constant temperature and humidity chamber for water evaporation treatment.

[0056] In the present invention, the application preferably is: sterilizing the high-strength and wet-slippery PVA hydrogel.

[0057] The sterilization treatment is preferably to soak the high-strength and highly slippery PVA hydrogel with the shape of a contact lens in a standard solution. In the present invention, the standard solution is preferably polyvinyl alcohol eye drops, contact lens multi-functional care solution or PBS buffer solution; the polyvinyl alcohol eye drops, contact lens multi-functional care solution or PBS buffer solution are all preferably commercially available products well-known in the art.

[0058] The high-strength and highly slippery PVA hydrogel provided by the present invention, its preparation method and application will be described in detail below with reference to embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0059] Example 1

[0060] A polyvinyl alcohol aqueous solution with a molecular weight of 77,000 and a mass concentration of 2.5% was placed in a petri dish, and water evaporation treatment was carried out at a temperature of 30 °C and a humidity of 30% for 96 h to obtain a PVA dry gel (water content: 3.5 wt%);

[0061] The PVA dry gel was soaked in a 0.3 mol / L aqueous solution of trisodium citrate for salting-out treatment for 24 hours at a temperature of 25 °C to obtain a salt-treated high-strength hydrogel (S-PVA);

[0062] After the salt-treated high-strength hydrogel was repeatedly washed 3 times with deionized water to remove the residual salt solution on the surface of S-PVA, it was subjected to a water balance treatment in water for 48 hours to obtain the high-strength and highly slippery PVA hydrogel (T-PVA).

[0063] Among them, the water content of the high-strength and highly slippery PVA hydrogel is 53.9 ± 2.7%; the breaking strength is 23.5 ± 2.7 MPa; the elastic modulus is 5.9 ± 0.1 MPa; the toughness is 35.4 ± 2.9 MJ / m 3 ; the transmittance is 98 ± 1%; the water contact angle is 15.8 ± 0.6°; the friction coefficient is 0.0431.

[0064] Example 2

[0065] A polyvinyl alcohol aqueous solution with a molecular weight of 77,000 and a mass concentration of 5.0% was placed in a petri dish, and water evaporation treatment was carried out at a temperature of 30 °C and a humidity of 30% for 96 h to obtain a PVA dry gel (water content: 3.8 wt%);

[0066] The PVA dry gel was soaked in a 0.3 mol / L aqueous solution of trisodium citrate for salting-out treatment for 24 hours at a temperature of 25 °C to obtain a salt-treated high-strength hydrogel (S-PVA);

[0067] After the salt-treated high-strength hydrogel was repeatedly washed three times with deionized water to remove the residual salt solution on the surface of S-PVA, it was subjected to a water balance treatment in water for 48 hours to obtain the high-strength and slippery PVA hydrogel (T-PVA).

[0068] Among them, the water content of the high-strength and slippery PVA hydrogel is 55.0 ± 1.4%; the breaking strength is 23.8 ± 2.1 MPa; the elastic modulus is 5.7 ± 0.3 MPa; the toughness is 40.2 ± 3.5 MJ / m 3 ; the transmittance is 97 ± 2%; the water contact angle is 17.5 ± 0.5°; the friction coefficient is 0.0423.

[0069] Example 3

[0070] A polyvinyl alcohol aqueous solution with a molecular weight of 146,000 and a mass concentration of 7.5% was placed in a petri dish and subjected to water evaporation treatment at a temperature of 30°C and a humidity of 30% for 96 h to obtain a PVA dry gel (water content: 4.2 wt%);

[0071] The PVA dry gel was immersed in a 0.3 mol / L aqueous solution of trisodium citrate for salting-out treatment for 24 hours at a temperature of 25°C to obtain a salt-treated high-strength hydrogel (S-PVA);

[0072] After the salt-treated high-strength hydrogel was repeatedly washed three times with deionized water to remove the residual salt solution on the surface of S-PVA, it was subjected to a water balance treatment in water for 48 hours to obtain the high-strength and slippery PVA hydrogel (T-PVA).

[0073] Among them, the water content of the high-strength and slippery PVA hydrogel is 53.0 ± 1.0%; the breaking strength is 26.7 ± 1.0 MPa; the elastic modulus is 5.4 ± 0.2 MPa; the toughness is 55.2 ± 1.6 MJ / m 3 ; the transmittance is 97 ± 1%; the water contact angle is 22.6 ± 0.2°; the friction coefficient is 0.0391.

[0074] Example 4

[0075] A polyvinyl alcohol aqueous solution with a molecular weight of 77,000 and a mass concentration of 10.0% was placed in a petri dish and subjected to water evaporation treatment at a temperature of 30°C and a humidity of 30% for 96 h to obtain a PVA dry gel (water content: 4.3 wt%);

[0076] The PVA dry gel was immersed in a 0.3 mol / L aqueous solution of sodium dihydrogen phosphate for salting-out treatment for 24 hours at a temperature of 25°C to obtain a salt-treated high-strength hydrogel (S-PVA);

[0077] After the salt-treated high-strength hydrogel was repeatedly washed three times with deionized water to remove the residual salt solution on the surface of S-PVA, it was subjected to a water balance treatment in water for 48 hours to obtain the high-strength wet-slip PVA hydrogel (T-PVA).

[0078] Among them, the water content of the high-strength wet-slip PVA hydrogel is 52.8 ± 1.3%; the breaking strength is 18.7 ± 1.2 MPa; the elastic modulus is 4.1 ± 0.3 MPa; the toughness is 38.7 ± 6.8 MJ / m 3 ; the transmittance is 97 ± 2%; the water contact angle is 21.6 ± 0.6°; the friction coefficient is 0.0359.

[0079] Figure 3 Regarding the wettability of the high-strength wet-slip PVA hydrogel described in Example 4, it can be seen from Figure 3 that the water contact angle of the PVA hydrogel is 16.6°;

[0080] Figure 6 Regarding the lubrication performance of the high-strength wet-slip PVA hydrogel described in Example 4 in pure water, PBS buffer solution, PVA eye drops and multi-functional contact lens care solution, it can be seen from Figure 6 that the friction coefficients of the high-strength wet-slip PVA hydrogel in pure water, PBS buffer solution, PVA eye drops and multi-functional contact lens care solution are 0.06423, 0.02800, 0.01307, and 0.00577 respectively.

[0081] Example 5

[0082] A polyvinyl alcohol aqueous solution with a molecular weight of 89000 and a mass concentration of 12.5% was placed in a petri dish and subjected to water evaporation treatment at a temperature of 30 °C and a humidity of 30% for 96 h to obtain a PVA dry gel (water content 4.6 wt%);

[0083] The PVA dry gel was soaked in a 0.3 mol / L sodium chloride aqueous solution for salting-out treatment for 24 hours at a temperature of 25 °C to obtain a salt-treated high-strength hydrogel (S-PVA);

[0084] After the salt-treated high-strength hydrogel was repeatedly washed three times with deionized water to remove the residual salt solution on the surface of S-PVA, it was subjected to a water balance treatment in water for 48 hours to obtain the high-strength wet-slip PVA hydrogel (T-PVA).

[0085] Among them, the water content of the high-strength wet-slip PVA hydrogel is 51.7 ± 0.6%; the breaking strength is 18.6 ± 0.9 MPa; the elastic modulus is 4.3 ± 0.2 MPa; the toughness is 33.0 ± 2.3 MJ / m 3; The transmittance is 97 ± 1%; the water contact angle is 14.4 ± 0.7°; the coefficient of friction is 0.0286.

[0086] Example 6

[0087] An aqueous solution of polyvinyl alcohol with a molecular weight of 77,000 and a mass concentration of 15% was placed in a petri dish and subjected to water evaporation treatment for 96 h at a temperature of 30 °C and a humidity of 30% to obtain a PVA dry gel (water content: 4.2 wt%).

[0088] The PVA dry gel was immersed in a 0.3 mol / L aqueous sodium carbonate solution for salting-out treatment for 24 hours at a temperature of 25 °C to obtain a salt-treated high-strength hydrogel (S-PVA).

[0089] After the salt-treated high-strength hydrogel was repeatedly washed 3 times with deionized water to remove the residual salt solution on the surface of S-PVA, it was subjected to water balance treatment in water for 48 hours to obtain the high-strength and wet-slippery PVA hydrogel (T-PVA).

[0090] Among them, the water content of the high-strength and wet-slippery PVA hydrogel is 52.5 ± 1.0%; the breaking strength is 14.2 ± 3.1 MPa; the elastic modulus is 4.6 ± 0.2 MPa; the toughness is 23.6 ± 5.1 MJ / m 3 ; The transmittance is 97 ± 2%; the water contact angle is 12.8 ± 0.9°; the coefficient of friction is 0.0225.

[0091] Figure 4 is the water content of the high-strength and wet-slippery PVA hydrogels described in Examples 1 to 6. From Figure 4 it can be seen that the water content of the PVA hydrogel is above 55%.

[0092] Figure 5 is the light transmittance of the high-strength and wet-slippery PVA hydrogels described in Examples 1 to 6. From Figure 5 it can be seen that the light transmittance of the PVA hydrogel is above 97%.

[0093] Example 7

[0094] An aqueous solution of polyvinyl alcohol with a molecular weight of 77,000 and a mass concentration of 7.5% was placed in a concave die mold for forming contact lenses, and the convex film was pressed and fixed with the concave die, and then placed in a constant temperature and humidity chamber at a temperature of 25 °C and a humidity of 30% for water evaporation treatment. After the water was completely evaporated, mechanical demolding was used for demolding to obtain a PVA dry gel lens (water content: 4.5 wt%).

[0095] The PVA dry gel lens is immersed in a 0.3 mol / L aqueous solution of trisodium citrate for salting-out treatment for 24 hours at a temperature of 25 °C to obtain a salt-treated high-strength hydrogel lens;

[0096] After the salt-treated high-strength hydrogel lens is repeatedly washed with deionized water to remove the residual salt solution on the surface of the salt-treated high-strength hydrogel lens, it is subjected to a water balance treatment in water for 24 hours to obtain the high-strength and wet-slippery PVA hydrogel contact lens;

[0097] The high-strength and wet-slippery PVA hydrogel contact lens is sterilized in a multi-functional contact lens care solution to obtain a complete high-strength and wet-slippery PVA hydrogel contact lens sample (as Figure 7 shown).

[0098] Example 8

[0099] An aqueous solution of polyvinyl alcohol with a molecular weight of 77000 and a mass concentration of 10.0% is placed in a concave die mold for forming a contact lens, and the convex film is pressed and fixed with the concave die, and then placed in a constant temperature and humidity box at a temperature of 25 °C and a humidity of 30% for water evaporation treatment. After the water is completely evaporated, demolding is carried out by a mechanical demolding method to obtain a PVA dry gel lens (water content: 4.1 wt%);

[0100] The PVA dry gel lens is immersed in a 0.3 mol / L aqueous solution of trisodium citrate for salting-out treatment for 24 hours at a temperature of 25 °C to obtain a salt-treated high-strength hydrogel lens;

[0101] After the salt-treated high-strength hydrogel lens is repeatedly washed with deionized water to remove the residual salt solution on the surface of the salt-treated high-strength hydrogel lens, it is subjected to a water balance treatment in water for 24 hours to obtain the high-strength and wet-slippery PVA hydrogel contact lens;

[0102] The high-strength and wet-slippery PVA hydrogel contact lens is sterilized in a multi-functional contact lens care solution to obtain a complete high-strength and wet-slippery PVA hydrogel contact lens sample.

[0103] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. Application of a high-strength and wet-slippery PVA hydrogel in the preparation of contact lenses, characterized in that, The high-strength and slippery PVA hydrogel is a high-strength and slippery PVA hydrogel in the shape of a contact lens; The preparation method of the high-strength and slippery PVA hydrogel is characterized by comprising the following steps: Performing water evaporation treatment on an aqueous solution of polyvinyl alcohol to obtain a PVA dry gel; Performing salting-out treatment on the PVA dry gel in a sodium salt solution and then performing water balance to obtain the high-strength and slippery PVA hydrogel; The water evaporation treatment is carried out under the conditions of constant temperature and humidity, the temperature of the water evaporation treatment is 25-60 °C, the humidity is 30%, and the time is 24-96 h; The time for water balance is 24-96 h.

2. The application according to claim 1, characterized in that The molecular weight of polyvinyl alcohol in the aqueous solution of polyvinyl alcohol is 77,000-146,000.

3. The application according to claim 1 or 2, characterized in that, The mass concentration of the aqueous solution of polyvinyl alcohol is 2.5-15.0%.

4. The application according to claim 1, characterized in that The sodium salt solution includes one or more of a sodium chloride solution, a sodium carbonate solution, a sodium bicarbonate solution, a disodium hydrogen phosphate solution, a sodium dihydrogen phosphate solution, and a trisodium citrate solution.

5. The application according to claim 1 or 4, characterized in that, The concentration of the sodium salt solution is 0.3-1.5 mol / L.

6. The application according to claim 1, wherein The time for the salting-out treatment is 1-96 h.

7. The application according to claim 1, characterized in that, The application is: sterilizing the high-strength and slippery PVA hydrogel.

Images