Silicon hydrogel, contact lens and method for preparing the same

Abstract

The present application relates to a silicone hydrogel prepared by polymerization of a polymerizable composition. The polymerizable composition comprises the following components: (a) a monofunctional siloxane monomer; (b) a hydrophilic N-vinyl amide monomer; (c) a hydrophobic vinyl monomer; (d) a hydrophilic vinyl monomer containing a hydroxyl group; (e) a non-silicone type vinyl crosslinker; and (f) a free radical initiator. The hydrophobic vinyl monomer has a refractive index greater than 1.41, and the hydrophobic vinyl monomer has a glass transition temperature greater than or equal to 60°C. The present application also relates to a contact lens prepared from the above silicone hydrogel and a method for preparing the same. The contact lens described herein has a release rate of up to 100%, and a dry sheet modulus preferably greater than 100 MPa.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of spectacle lens materials, in particular to a silicon hydrogel for preparing a contact lens, a contact lens prepared from the silicon hydrogel and a method for preparing the contact lens. BACKGROUND

[0002] A contact lens, also known as a "soft lens", is a lens placed on the cornea of an eyeball to correct vision or protect the eye. The contact lens not only brings great improvement in appearance and convenience to patients with ametropia such as myopia, hypermetropia and astigmatism, but also has a wide field of view and realistic vision. In addition, it also plays a special role in controlling the development of myopia and astigmatism in adolescents and treating special eye diseases.

[0003] Silicone hydrogel contact lenses have been increasingly popular with users due to their high oxygen permeability and excellent comfort. At present, the main method for preparing silicone hydrogel contact lenses is molding, specifically a full-mold method using a detachable mold.

[0004] In the existing molding method, a predetermined amount of polymerizable or crosslinkable material is introduced into a detachable mold comprising a female mold half with a concave forming surface and a male mold half with a convex forming surface. The female mold half and the male mold half cooperate to form a mold cavity having the desired geometry of the contact lens. Generally, an excess amount of polymerizable or crosslinkable material is used so that when the male and female mold halves of the mold are closed, the excess material is discharged to an overflow area adjacent to the mold cavity. The polymerizable or crosslinkable material remaining in the mold is polymerized or crosslinked by actinic irradiation (e.g. UV radiation, ionizing radiation, microwave radiation) or by heating. The raw material in the mold cavity is cured to form a lens, while the excess material in the overflow area is partially or completely cured to form a flash ring. After curing, the mold is separated into the male mold half and the female mold half, and the contact lens formed adheres to the male mold half or the female mold half.

[0005] However, the existing molding method has the disadvantage that the flash formed by the excess amount of polymerizable or crosslinkable material can easily lead to a decrease in the yield of the contact lens, and hot water needs to be used to steam the mold or ultrasonic waves need to be used to separate the contact lens from the mold during demolding.

[0006] Therefore, there is a continuous need in the art to develop a contact lens that is easy to demold and a method for preparing the same. SUMMARY

[0007] The present application aims to provide a silicone hydrogel which is easy to demold. Specifically, the silicone hydrogel described herein can be prepared from a polymerizable composition by polymerization, and the polymerizable composition comprises specific monofunctional siloxane monomers and hydroxyl-containing hydrophilic vinyl monomers, the hydroxyl groups of which can form hydrogen bonds in the network of the silicone hydrogel, which on the one hand enhances the mechanical properties of the resulting contact lens, and on the other hand imparts to the contact lens a tendency to move away from the hydrophobic mold, thereby making the contact lens easier to demold.

[0008] The present application also aims to provide a contact lens prepared from the silicone hydrogel.

[0009] The present application also aims to provide a method for preparing a contact lens as described above.

[0010] To solve the above technical problems, the present application provides the following technical solutions.

[0011] In a first aspect, the present application provides a silicone hydrogel which can be prepared from a polymerizable composition by polymerization. The polymerizable composition comprises the following components: (a) monofunctional siloxane monomers selected from one or more of vinyl-terminated polysiloxane, acrylate-terminated polysiloxane, (3-methacryloyloxy-2-hydroxypropoxy)propyl bis(trimethylsiloxy)methyl, 3-[tris(trimethylsiloxy)silyl]propyl methacrylate and methacrylate-terminated polysiloxane; (b) a hydrophilic N-vinylamide monomer; (c) a hydrophobic vinyl monomer; (d) a hydroxyl-containing hydrophilic vinyl monomer which is a hydroxyalkyl acrylate or a hydroxyalkyl methacrylate; (e) a non-silicone type vinyl crosslinking agent; and (f) a free radical initiator. The refractive index of the hydrophobic vinyl monomer is greater than 1.41, and the glass transition temperature of the hydrophobic vinyl monomer is greater than or equal to 60°C.

[0012] In a second aspect, the present application provides a contact lens prepared from the silicone hydrogel as described in the first aspect.

[0013] In a third aspect, the present application provides a method for preparing a contact lens, the method comprising the following steps:

[0014] S1: providing a mold comprising a male mold half having a convex molding surface and a female mold half having a concave molding surface, wherein the male mold half and the female mold half are configured to receive each other so as to form a mold cavity between the convex molding surface and the concave molding surface when the mold is closed;

[0015] S2: dispensing a predetermined weight of a polymerizable composition into the female mold half;

[0016] S3: mating the male mold half and the female mold half to close the mold;

[0017] S4: curing the polymerizable composition located in the mold cavity, thereby forming a molded contact lens;

[0018] S5: separating the mold into the male mold half and the female mold half, the contact lens adhering to one of the male mold half and the female mold half;

[0019] S6: pressing the mold half with the contact lens adhering thereto to separate the mold half and the contact lens;

[0020] S7: removing the contact lens from the mold half by a vacuum suction device.

[0021] Compared with the prior art, the positive effect of the present application is that the contact lens described herein has good demolding performance while ensuring good mechanical properties, and no hot water cooking or ultrasonic treatment is required during the demolding process. Only the convex or concave forming surface of the mold is deformed by pressing the mold, so that the mold and the contact lens are separated. Subsequently, only a vacuum suction nozzle is required to remove the contact lens from the mold. The demolding rate of the contact lens can reach 100%, and the dry sheet modulus is preferably greater than 100 MPa. In addition, the contact lens described herein can reduce excess flash by optimizing the injection amount during preparation. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1A Dry sheet ATR-FTIR spectra of Examples 1-4 and Comparative Example 1 are shown. The displacement of the ester bond carbonyl absorption peak due to hydrogen bonding.

[0023] Figure 1B Dry sheet ATR-FTIR spectra of Examples 1-4 and Comparative Example 1 are shown. The displacement of the ester bond carbonyl absorption peak due to hydrogen bonding.

[0024] Figure 2 A side view schematic diagram of the male mold half and the female mold half is shown.

[0025] Figure 3 A schematic diagram of the male mold half demolding device is shown.

[0026] Figure 4 A perspective view of the male mold half demolding device is shown.

[0027] Figure 5 A perspective view of the female mold half demolding device is shown.

[0028] Figure 6 A side view of the female mold half demolding device is shown.

[0029] Figure 7 Figure 2 shows a top view of a female mold half demolding device.

[0030] Figure 8 Figure 4 shows a dry cast stretch curve for the contact lens of Example 1.

[0031] Figure 9 Figure 6 shows a dry cast stretch curve for the contact lens of Example 2.

[0032] Figure 10 Figure 8 shows a dry cast stretch curve for the contact lens of Example 3.

[0033] Figure 11 Figure 10 shows a dry cast stretch curve for the contact lens of Example 4.

[0034] Figure 12 Figure 12 shows a dry cast stretch curve for the contact lens of Comparative Example 1. DETAILED DESCRIPTION

[0035] Unless otherwise indicated, all parts and percentages expressed herein are based on weight and all tests and measurements are made at the date of filing of this application. To the extent that any patent, patent application, or publication is cited in this application, the contents of all such citations are hereby incorporated by reference into this application, and equivalents are contemplated as falling within the scope of the same, particularly with respect to the definitions of the terms synthetic techniques, products and processing designs, polymers, comonomers, initiators or catalysts, etc. disclosed therein. If a definition of a specific term in the prior art is inconsistent with any definition provided herein, the definition provided herein shall control.

[0036] Numerical ranges are approximations, and thus the endpoints should be considered to be approximations also, unless otherwise indicated. A numerical range includes all values from and including the lower and to and including the upper value of the range. For ranges comprising a lower value Q and an upper value Q, unless otherwise stated, the range is intended to include Q and Q individually. As is apparent from this description, some of the numerical ranges specifically stated will include one or both of the endpoints, while other numerical ranges specifically stated will exclude one or both of the endpoints. For ranges including a lower value Q and logically corresponding upper value, ranges of Q to Q are understood to include Q, Q, and sub-ranges covering the same. All numerical ranges hereinafter are understood to include every number and subset between the upper and lower values of that range. For numerical ranges that include endpoints, include the endpoints, unless the context clearly indicates otherwise. Also, for ranges including a lower value Q and a value Q, the range is understood to include Q, Q, and sub-ranges covering the same. These are only examples of what is specifically asserted to be the minimum and maximum values. Numerous other combinations and subdivisions of the ranges listed here can be contrived and are to be construed as specifically stated in this application. For example, a range stated to be 1 to 10 includes 1, 1.1, 1.2, 1.3, etc. up to 10. A range stated to be 5 to 10 includes 5, 6, 7, 8, 9, 10, and sub-ranges such as 5 to 6, 7 to 8, 8 to 9, etc. It is specifically intended that the description set forth in this application include all of these combinations and subdivisions. In addition, the use of "first", "second", "third", etc. to describe a common object, unless otherwise stated, is only to identify and differentiate that common object.

[0037] With respect to chemical compounds, the singular forms "a", "an" and "the" include all isomeric forms, unless the specific forms are otherwise indicated (e.g., "hexane" alone or in combination includes all isomers of hexane). Additionally, the singular forms "a", "an", and "the" include the plural unless the context clearly indicates otherwise.

[0038] The terms "comprising", "including", "containing", and variations thereof, do not exclude the presence of other components, steps or processes, and are used synonymously with the term "including". For the avoidance of doubt, unless specifically stated otherwise, the use of the term "comprising" in the present application is not intended to exclude the presence of any additional additives, adjuvants or compounds. In contrast, the term "consisting essentially of does exclude any component, step or process not specifically recited. The term "consisting of does not include any component, step or process not specifically recited. The term "or" as used in the present application means any one member of a logical disjunction, conjunctively unless the context clearly indicates otherwise.

[0039] Definitions of Terms

[0040] As used herein, the term "hydrogel" refers to a polymeric material that can absorb at least 10 percent by weight of water when the polymeric material is fully hydrated. Typically, hydrogel materials are obtained by polymerization or copolymerization of at least one hydrophilic monomer, in the presence or absence of additional monomers and / or macromonomers.

[0041] In the present text, the term "silicone hydrogel" refers to a hydrogel obtained by copolymerization of a polymerizable composition comprising at least one siloxane-containing monomer or at least one siloxane-containing macromolecule.

[0042] In the present text, the term "monomer" refers to a low molecular weight compound having an average molecular weight of less than 700 Dalton, comprising one or more polymerizable groups or one or more crosslinkable groups, and which can be crosslinked and / or polymerized photochemically or thermally or chemically to obtain a crosslinked and / or polymerized polymer. "Photochemical" as used herein in connection with the curing or polymerization of a polymerizable composition or material refers to curing (e.g. crosslinking and / or polymerization) by photochemical irradiation, such as by UV irradiation, ionizing radiation (e.g. gamma or X-ray irradiation), microwave irradiation, etc. Methods of thermal curing or photochemical curing are well known to the person skilled in the art.

[0043] In the present text, the term "macromonomer" refers to a medium and high molecular weight compound or polymer comprising functional groups capable of undergoing further polymerization / crosslinking reactions. Medium and high molecular weight generally refers to an average molecular weight of more than 700 Dalton. Preferably, the macromonomer contains ethylenically unsaturated groups and can be polymerized photochemically or thermally.

[0044] In the present text, the term "polymer" refers to a material formed by polymerization / crosslinking of one or more monomers, macromonomers and / or oligomers.

[0045] In the present text, the term "mold" refers to a male mold half and a female mold half.

[0046] In the present text, the term "mold half" refers to either one or both of a male mold half and a female mold half.

[0047] Unless otherwise indicated or unless the context clearly indicates otherwise, the "molecular weight" of a polymeric material (including monomeric or macromonomeric materials) as used herein refers to the number average molecular weight.

[0048] Silicon Hydrogel

[0049] In a first aspect, the present application provides a silicone hydrogel useful for the manufacture of a contact lens, the silicone hydrogel having a good demolding rate.

[0050] In one specific embodiment, the silicone hydrogel is prepared by polymerization of a polymerizable composition. The polymerizable composition comprises the following components: (a) a monofunctional siloxane monomer; (b) a hydrophilic N-vinylamide monomer; (c) a hydrophobic vinyl monomer; (d) a hydroxyl-containing hydrophilic vinyl monomer, wherein the hydroxyl-containing hydrophilic vinyl monomer is a hydroxyalkyl acrylate or a hydroxyalkyl methacrylate; (e) a non-siloxane type vinyl crosslinking agent; and (f) a free radical initiator. In this embodiment, the hydrophobic vinyl monomer has a refractive index greater than 1.41 and a glass transition temperature greater than or equal to 60°C.

[0051] In one embodiment, the monofunctional siloxane monomer is selected from one or more of vinyl-terminated polysiloxanes, acrylate-terminated polysiloxanes, and methacrylate-terminated polysiloxanes. In a specific embodiment, the monofunctional siloxane monomer includes, but is not limited to, (meth)acrylate-terminated polydimethylsiloxane. In a preferred embodiment, the weight-average molecular weight of the monofunctional siloxane monomer is 600-1000, preferably 600, 650, 700, 750, 800, 900, 1000, or any two of these values ​​or a subrange thereof.

[0052] Monofunctional siloxane monomers are one of the main raw materials for forming silicone hydrogels. After cross-linking, monofunctional siloxane monomers can form the backbone polymer network of silicone hydrogels, resulting in soft corneal contact lenses that better fit the cornea. Furthermore, the hydroxyl groups carried by the monofunctional siloxane monomers ensure that the silicone hydrogel has good oxygen permeability.

[0053] In this application, there is no particular limitation on the weight ratio of monofunctional siloxane monomers in the polymerizable composition, as long as they can form a silicone hydrogel and provide the required mechanical and oxygen permeability. In one specific embodiment, the monofunctional siloxane monomer may account for 35%-40% of the total weight of the polymerizable composition, for example, 35%, 36%, 37%, 38%, 39%, 40%, or any two of these values ​​or sub-ranges.

[0054] Hydrophilic N-vinyl amide monomers are also one of the main raw materials for forming the silicone hydrogel and are used to improve the water absorption of the resulting silicone hydrogel or contact lens. In one embodiment, the hydrophilic N-vinyl amide monomers include, but are not limited to, the following: N-methyl-N-vinylacetamide, (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-ethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-3-methoxypropyl(meth)acrylamide.

[0055] In the present application, the weight proportion of the hydrophilic N-vinyl amide monomers in the polymerizable composition is not particularly limited as long as the silicone hydrogel can be formed and the required mechanical properties and oxygen permeability can be provided. In one embodiment, the hydrophilic N-vinyl amide monomers can account for 40% to 50% of the total weight of the polymerizable composition, for example, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50% or a range or sub-range between any two of the values of the total weight of the polymerizable composition.

[0056] The specific combination of the hydrophobic vinyl monomer and the hydroxyl-containing hydrophilic vinyl monomer allows the contact lens of the present application to have a good demolding rate. In a preferred embodiment, the refractive index of the hydrophobic vinyl monomer is greater than 1.41, and the glass transition temperature of the hydrophobic vinyl monomer is greater than or equal to 60°C. The monomer with a high glass transition temperature Tg generally forms a polymer after polymerization, which is relatively hard and has a high mechanical strength such as modulus, which is helpful for demolding. In this way, the hydrophobic vinyl monomer can provide sufficient mechanical strength to the resulting silicone hydrogel. In addition, the hydroxyl group of the hydroxyl-containing hydrophilic vinyl monomer can form hydrogen bonds in the network of the silicone hydrogel, which on the one hand enhances the mechanical properties of the resulting contact lens, and on the other hand makes the contact lens have a tendency to move away from the hydrophobic mold, thereby making the contact lens easier to demold.

[0057] Referring to Figure 1, Figure 1 shows the infrared spectra of the silicone hydrogels prepared from polymerizable compositions with different contents of 2-hydroxyethyl methacrylate (HEMA). As can be seen from Figure 1, the formulation of Comparative Example 1 without HEMA hydroxyl group has a C=O characteristic vibration peak at 1727 cm -1 , and the formulations of Examples 1 to 4 containing HEMA, as the content of HEMA increases, the absorption peak shifts to the short wave number, and there is a small shoulder peak at 1703 cm -1 , which indicates the presence of hydrogen bond C=O...H-O.

[0058] In one embodiment, the hydrophobic vinyl monomer includes, but is not limited to, the following: cyclohexyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, t-butyl methacrylate, styrene, methylstyrene, 4-t-butylstyrene, 4-ethoxystyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,5-dimethylstyrene, and a benzene ring containing acrylate. In a preferred embodiment, the benzene ring containing acrylate preferably includes one or more of phenylethyl acrylate, phenylethyl methacrylate, norbornyl isobutyl acrylate, and norbornyl isobutyl methacrylate.

[0059] In one embodiment, the hydrophobic vinyl monomer comprises 5% to 20% by weight of the total weight of the polymerizable composition. For example, the hydrophobic vinyl monomer comprises 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or a range or sub-range between any two of these values, of the total weight of the polymerizable composition.

[0060] In one embodiment, the hydrophilic vinyl monomer includes, but is not limited to, the following: 2-hydroxypropyl (meth)acrylate, N-2-hydroxyethyl (meth)acrylamide, N,N-bis(hydroxyethyl) (meth)acrylamide, N-3-hydroxypropyl (meth)acrylamide, N-2-hydroxypropyl (meth)acrylamide, N-2,3-dihydroxypropyl (meth)acrylamide, N-tris(hydroxymethyl)methyl (meth)acrylamide, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, glyceryl methacrylate (GMA), di(ethylene glycol) (meth)acrylate, tri(ethylene glycol) (meth)acrylate, tetra(ethylene glycol) (meth)acrylate, poly(ethylene glycol) (meth)acrylate having a number average molecular weight of up to 1500, poly(ethylene glycol) ethyl (meth)acrylamide having a number average molecular weight of up to 1500.

[0061] In one embodiment, the hydrophilic vinyl monomer comprises 1% to 20% by weight of the total weight of the polymerizable composition. Preferably, the hydrophilic vinyl monomer comprises 5% to 10% by weight of the total weight of the polymerizable composition. For example, the hydrophilic vinyl monomer comprises 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or a range or sub-range between any two of these values, of the total weight of the polymerizable composition.

[0062] In one embodiment, the non-silicone based vinyl crosslinker is selected from one or more of ethylene glycol dimethacrylate and triethylene glycol dimethacrylate. In one embodiment, the free radical initiator is selected from one or more of peroxides, hydroperoxides, azo-bis(alkyl- or cycloalkyl nitriles), persulfates, percarbonates or mixtures thereof. In one embodiment, the free radical initiator includes, but is not limited to, benzoyl peroxide, t-butyl peroxide, t-amyl peroxybenzoate, 2,2-bis(t-butylperoxy)butane, 1,1-bis(t-butylperoxy)cyclohexane, 2,5-bis(t-butylperoxy)-2,5-dimethylhexane, 2,5-bis(t-butylperoxy)-2,5-dimethyl-3-hexyne, bis(1-(t-butylperoxy)-1-methylethyl)benzene, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, di-t-butyl diperphthalate, t-butyl hydroperoxide, t-butyl peracetate, t-butyl peroxybenzoate, t-butylperoxy isopropyl carbonate, acetyl peroxide, lauroyl peroxide, decanoyl peroxide, dicetyl peroxydicarbonate, di(4-t-butylcyclohexyl) peroxydicarbonate (Perkadox 16S), di(2-ethylhexyl) peroxydicarbonate, t-butylperoxy pivalate (Lupersol 11), t-butylperoxy-2-ethylhexyl (Trigonox 21-C50), 2,4-pentanedione peroxide, dicumyl peroxide, peracetic acid, potassium persulfate, sodium persulfate, ammonium persulfate, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) (VAZO 33), 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride (VAZO 44), 2,2'-azobis(2-amidinopropane) dihydrochloride (VAZO 50), 2,2'-azobis(2,4-dimethylvaleronitrile) (VAZO 52), 2,2'-azobis(isobutyronitrile) (VAZO 64 or AIBN), 2,2'-azobis-2-methylbutyronitrile (VAZO 67), 1,1-azobis(1-cyclohexanecarbonitrile) (VAZO 88); 2,2'-azobis(2-cyclopropylpropionitrile), 2,2'-azobis(methyl isobutyrate), 4,4'-azobis(4-cyanovaleric acid), and combinations thereof. Preferably, the free radical initiator is 2,2'-azobis(isobutyronitrile) (AIBN or VAZO 64).

[0063] The amount and role of the non-silicone based vinyl crosslinker and the free radical initiator are well known in the art and will not be repeated here.

[0064] Contact Lenses and Methods for Making Same

[0065] In a second aspect, the present application provides a contact lens made of the silicone hydrogel as described above. In a third aspect, the present application provides a method for making a contact lens.

[0066] In one embodiment, the method for making a contact lens can comprise the following steps:

[0067] S1 : providing a mold comprising a male mold half having a convex molding surface and a female mold half having a concave molding surface, wherein the male mold half and the female mold half are configured to receive each other so as to form a mold cavity between the convex molding surface and the concave molding surface when the mold is closed;

[0068] S2: dispensing a predetermined weight of the polymerizable composition into the female mold half;

[0069] S3: mating the male mold half and the female mold half to close the mold;

[0070] S4: curing the polymerizable composition located in the mold cavity, thereby forming a molded contact lens;

[0071] S5: separating the mold into the male mold half and the female mold half, the contact lens adhering to one of the male mold half and the female mold half;

[0072] S6: pressing the mold half with the contact lens adhering thereto so as to separate the mold half and the contact lens;

[0073] S7: removing the contact lens from the mold half by a vacuum suction device.

[0074] In one embodiment, the male mold half and the female mold half are non-polar, and either the male mold half or the female mold half can be subjected to a plasma beam treatment prior to step S1, so that the contact lens adheres to the male mold half or the female mold half subjected to the plasma beam treatment. For example, both the male mold half and the female mold half can be made of polypropylene. In another embodiment, one of the male mold half and the female mold half is polar, and the other is non-polar, and the contact lens adheres to the polar male mold half or the polar female mold half. For example, the male mold half can be made of polybutylene terephthalate (PBT), and the contact lens adheres to the male mold half after the silicone hydrogel is cured. In this case, the female mold half can be non-polar.

[0075] Reference Figure 2 , Figure 2A side view of the male mold half 1 and the female mold half 2 is shown. The male mold half 1 can include a cylindrical male mold body 11, one end of which includes a convex molding surface 12 for molding the inner surface of the corneal contact lens on the side facing the user's eye. The male mold body 11 can also include an annular flange 13 disposed on the outer periphery of the male mold body 11. This annular flange 13 is engaged by the male mold demolding device 10 (see Figure 3 ) described below to grip the male mold half 1 and to rotate the male mold half 1 in a predetermined direction (see Figure 3 arrow direction).

[0076] Similarly, the female mold half 2 can include a cylindrical male-female mold body 21, one end of which includes a concave molding surface 22 for molding the outer surface of the corneal contact lens on the side facing away from the user's eye. The female mold body 21 can also include an annular flange 23 disposed on the outer periphery of the female mold body 21. The female mold demolding device 20 can grip the female mold half 2 by engaging with this annular flange 23, as described below. When the male mold half 1 and the female mold half 2 are mated, a mold cavity is formed between the convex molding surface 12 and the concave molding surface 22, which has the same shape as the corneal contact lens to be produced.

[0077] Next, the demolding method for the corneal contact lens will be described in detail.

[0078] In step S5, the corneal contact lens can be adhered to either the male mold half or the female mold half, depending on the polymerizable composition used, the polarity of the mold halves, etc. When they are adhered to different mold halves, the subsequent demolding step S7 is also different.

[0079] In one specific embodiment, the corneal contact lens is adhered to the male mold half 1. When the corneal contact lens is adhered to the male mold half 1, the pressing of the mold half to which the corneal contact lens is adhered in step S7 includes pressing the male mold half 1 in the radial direction of the male mold half 1 toward the male mold half 1, causing the convex molding surface 12 of the male mold half 1 to deform.

[0080] Specifically, the male mold half 1 can be pressed by the male mold demolding device 10. Referring to Figure 3 and Figure 4The male mold release device 10 may include an arc-shaped outer clamping plate 101 and an arc-shaped inner clamping plate 102 disposed on the male mold base 100. The inner clamping plate 102 is a rotatable rotating disk. The gap between the outer clamping plate 101 and the arc-shaped inner clamping plate 102 gradually decreases along the rotation direction of the inner clamping plate 102. In addition, the outer clamping plate 101 may include an outer clamping plate groove 103 recessed in a direction away from the inner clamping plate 102, and the inner clamping plate 102 may include an inner clamping plate groove 104 recessed in a direction away from the outer clamping plate 101. The outer clamping plate groove 103 and the inner clamping plate groove 10 are at the same height relative to the male mold base 100. When the male mold 1 is pressed, the annular flange 13 of the male mold 1 with the corneal contact lens attached can be engaged in the corresponding outer clamping plate groove 103 and inner clamping plate groove 104. Then, the inner clamping plate 102 is moved relative to the outer clamping plate 101 in a direction that reduces the gap between the inner and outer clamping plates 101, thus compressing the male half-mold 1. The male half-mold 1 undergoes slight deformation after being compressed. Because the deformation of the male half-mold 1 differs from that of the corneal contact lens, the corneal contact lens separates from the male half-mold 1. In one specific embodiment, such as... Figure 3 As indicated by the arrow, the gap between the outer retaining plate 101 and the inner retaining plate 102 gradually decreases in a clockwise direction. The separated corneal contact lens can be removed from the male half-mold 1 using a vacuum nozzle.

[0081] To ensure synchronized movement between the male half-mold 1 and the corresponding inner clamping plate 102 or outer clamping plate 101, so as to facilitate rapid forward movement of the male half-mold 1 during the rotation of the inner clamping plate 102, in one embodiment, the annular outer surface of the annular flange 13 of the male half-mold 1, and the bottom of one or both of the grooves of the outer clamping plate groove 103 and the inner clamping plate groove 104 are formed with surfaces that can improve friction, such as frosted texture or grid texture. In another embodiment, the annular outer surface of the annular flange 13 of the male half-mold 1, and the bottom of one or both of the grooves of the outer clamping plate groove 103 and the inner clamping plate groove 104 are provided with corresponding teeth.

[0082] In another specific embodiment, the corneal contact lens is adhered to the negative half-mold 2. When the corneal contact lens is adhered to the negative half-mold 2, squeezing the half-mold with the corneal contact lens attached includes squeezing the negative half-mold 2 from one side toward the corneal contact lens side along the longitudinal direction of the negative half-mold 2, causing the concave molding surface 22 of the negative half-mold 2 to deform.

[0083] Specifically, it can be achieved through Figures 5-7 The female mold ejection device 20 shown is used to extrude the female mold 2. (Reference) Figures 5-7The female mold demolding device 20 can include a female mold base 200 and a limiting frame 201 and a supporting frame 202 arranged on the female mold base 200. The limiting frame 201 and the supporting frame 202 can move relative to each other. The limiting frame 201 is substantially an inverted U-shaped, i.e., an opening of a U-shaped towards the female mold base 200, and two side walls defining the U-shaped are provided with grooves 203 towards each other. The grooves 203 are used to clamp the annular flange 23 of the female mold 2. The central part of the supporting frame 202 includes a top rod 204 which can move up and down relative to the supporting frame 202 along the longitudinal direction of the supporting frame 202. When demolding the male mold 2 to which the corneal contact lens is adhered, the female mold 2 can be first placed on the supporting frame 202, wherein the upper surface of the female mold 2 to which the corneal contact lens is adhered is away from the supporting frame 202, and the lower surface of the female mold 2 is supported by the supporting frame 202. The placement orientation of the female mold 2 can be understood in combination with the placement direction of the female mold 2, the supporting frame 202 in Figure 2 and Figure 6 (Or Figure 5 ). Then, the limiting frame 201 is moved forward along the driving rod 205 shown in Figure 5 , so that the annular flange of the female mold 2 is clamped in the grooves 203 of the limiting frame 201. Finally, the top rod 204 is pushed upward at a position corresponding to the top of the outer surface of the female mold 2 concave molding surface 22 to a predetermined distance, so that the female mold 2 is deformed. Because the deformation amount of the female mold 2 is different from that of the corneal contact lens, the corneal contact lens is separated from the female mold 2. The separated corneal contact lens can be taken off from the female mold 2 by a vacuum suction nozzle.

[0084] Examples

[0085] The technical solutions of the present application will be described clearly and completely in combination with the embodiments of the present application. Unless otherwise specified, the reagents and raw materials used can be purchased through commercial channels. The experimental methods not specified in the following examples are selected according to conventional methods and conditions, or according to the product instructions.

[0086] In the following examples, the specific determination process of infrared spectrum is as follows.

[0087] The infrared test of the dry film was carried out on a Bruker Lumos micro-ATR FTIR infrared chromatograph: ATR mode was used, and the probe was a Ge crystal. The scanning resolution was 4 cm -1 , and the average value was taken after 32 times of single sample scanning. During measurement, the probe was first scanned for air background, and then the germanium crystal probe was directly applied to the surface of the dry film with a "mild" force. After the spectrum was collected, the Bruker Opus software was used for analysis.

[0088] In the following examples, the specific determination process of the dry film modulus is as follows.

[0089] The dry sheet modulus was measured on a LPS-20CL soft contact lens tensile strength tester. Specifically, the dry sheet was cut radially into a curved strip of 5 mm width. The sample was fixed by the clamps of the tensile tester with an initial length of 5 mm between the clamps. The tensile speed was 10 mm / min. After the sample was broken, the Young's modulus, the breaking strength and the breaking elongation were automatically calculated by the software.

[0090] In the following examples, the release properties of the formulations and the prepared contact lenses of Examples 1-4 and Comparative Example 1 are shown in Table 1.

[0091] Table 1 Release properties of the formulations and the prepared contact lenses of Examples 1-4 and Comparative Example 1

[0092]

[0093] In Table 1, VMA refers to N-methyl-N-vinylacetamide, MMA refers to methyl methacrylate, HEMA refers to 2-hydroxyethyl methacrylate, Vazo 67 refers to azobis- isobutyronitrile, EGDMA refers to ethylene glycol dimethacrylate, and De-lens% refers to the contact lens release rate.

[0094] Example 1

[0095] This example relates to the preparation of a contact lens.

[0096] The experimental steps of this example are described as follows.

[0097] According to the formulation shown in Table 1, 38 parts by weight of PDMS-MA-800, 45 parts by weight of VMA, 16 parts by weight of HEMA, 0.5 parts by weight of VAZO 67 and 0.5 parts by weight of EGDMA were mixed to obtain the polymerizable composition according to Example 1.

[0098] The polymerizable composition according to Example 1 was poured into the mold cavity formed by the male mold and the female mold, and the mold was made of polypropylene material with a mold closing pressure of 5 kg. The mold was placed in a nitrogen oven, and the nitrogen flow rate was 70 L / min. The mold was first purged at room temperature for 30 minutes, and then the temperature was raised to 55 / 80 / 100 degrees according to the preset program of the oven, and each temperature was maintained for 40 minutes to obtain the silicone hydrogel according to Example 1. In this example, 15 parallel experiments were performed, and the silicone hydrogels were all adhered to the female mold 2. The male mold 2 was released using the female mold release device 20 to obtain the contact lens dry sheet according to Example 1. The contact lens release rate (De-lens%) was 100%.

[0099] In addition, the infrared spectrum of the contact lens dry sheet according to Example 1 was also determined, and the results are shown in Figure 1.

[0100] In addition, the modulus of the dry contact lens sheet according to Example 1 was measured, and the results are shown in Table 1. Figure 8

[0101] Example 2

[0102] This example relates to the preparation of a contact lens.

[0103] The experimental procedure of this example is described below.

[0104] According to the formulation shown in Table 1, 38 parts by weight of PDMS-MA-800, 45 parts by weight of VMA, 5 parts by weight of MMA, 11 parts by weight of HEMA, 0.5 parts by weight of VAZO 67, and 0.5 parts by weight of EGDMA were mixed to obtain the polymerizable composition according to Example 2.

[0105] The polymerizable composition according to Example 2 was poured into the mold cavity formed by the male and female molds, which were made of polypropylene, and the mold was closed with a pressure of 5 kg. The mold was placed in a nitrogen oven, and the nitrogen flow rate was 70 L / min. The mold was first purged at room temperature for 30 minutes, and then the temperature was raised to 55 / 80 / 100 degrees according to the preset program of the oven, and each temperature was maintained for 40 minutes, to obtain the silicone hydrogel according to Example 1. In this example, 15 parallel experiments were performed, and the silicone hydrogels were all adhered to the female mold 2. The male mold 2 was demolded using the female mold demolding device 20, to obtain the contact lens dry sheet according to Example 2. The contact lens demolding rate (De-Lens %) was 100%.

[0106] In addition, the infrared spectrum of the contact lens dry sheet according to Example 2 was measured, and the results are shown in Figure 1.

[0107] In addition, the modulus of the contact lens dry sheet according to Example 2 was measured, and the results are shown in Table 1. Figure 9

[0108] Example 3

[0109] This example relates to the preparation of a contact lens.

[0110] According to the formulation shown in Table 1, 38 parts by weight of PDMS-MA-800, 45 parts by weight of VMA, 5 parts by weight of MMA, 11 parts by weight of HEMA, 0.5 parts by weight of VAZO 67, and 0.5 parts by weight of EGDMA were mixed to obtain the polymerizable composition according to Example 2.

[0111] ​​The polymerizable composition according to Example 3 was poured into the mold cavity formed by the male mold half and the female mold half, the mold was made of polypropylene material, the mold clamping pressure was 5 kg. The mold was placed in a nitrogen oven, first room temperature purging for 30 minutes, and then according to the preset program of the oven, the temperature was raised to 55 degrees / 80 degrees / 100 degrees respectively and kept at each temperature for 40 minutes, to obtain the silicone hydrogel according to Example 2. In this example, 15 parallel experiments were conducted, and the silicone hydrogels were all adhered to the female mold half 2. The male mold half 2 was demolded using the female mold half demolding device 20 to obtain the corneal contact lens dry sheet according to Example 3. The corneal contact lens demolding rate (De-Lens%) was 100%.

[0112] In addition, the infrared spectrum of the corneal contact lens dry sheet according to Example 3 was also determined, and the results are shown in Figure 1.

[0113] In addition, the modulus of the corneal contact lens dry sheet according to Example 3 was also determined, and the results are shown in Figure 2. Figure 10

[0114] Example 4

[0115] This example is similar to Example 1, except that the amount of HEMA is 5 parts by weight.

[0116] According to the formula shown in Table 1, 38 parts by weight of PDMS-MA-800, 45 parts by weight of VMA, 11 parts by weight of MMA, 5 parts by weight of HEMA, 0.5 parts by weight of VAZO 67 and 0.5 parts by weight of EGDMA were mixed to obtain the polymerizable composition according to Example 4.

[0117] The polymerizable composition according to Example 3 was poured into the mold cavity formed by the male mold half and the female mold half, the mold was made of polypropylene material, the mold clamping pressure was 5 kg. The mold was placed in a nitrogen oven, first room temperature purging for 30 minutes, and then according to the preset program of the oven, the temperature was raised to 55 degrees / 80 degrees / 100 degrees respectively and kept at each temperature for 40 minutes, to obtain the silicone hydrogel according to Example 2. In this example, 15 parallel experiments were conducted, and the silicone hydrogels were all adhered to the female mold half 2. The male mold half 2 was demolded using the female mold half demolding device 20 to obtain the corneal contact lens dry sheet according to Example 3. The corneal contact lens demolding rate (De-Lens%) was 100%.

[0118] In addition, the infrared spectrum of the corneal contact lens dry sheet according to Example 4 was also determined, and the results are shown in Figure 1.

[0119] ​Furthermore, the modulus of the dry contact lens sheet according to Example 4 was measured, and the results are shown in Table 1. Figure 11

[0120] Comparative Example 1

[0121] According to the formulation shown in Table 1, 38 parts by weight of PDMS-MA-800, 45 parts by weight of VMA, 8 parts by weight of MMA, 8 parts by weight of HEMA, 0.5 parts by weight of VAZO 67, and 0.5 parts by weight of EGDMA were mixed to obtain the polymerizable composition according to Example 3.

[0122] The polymerizable composition according to Example 3 was poured into the mold cavity formed by the male and female molds, and the mold was made of polypropylene material with a mold clamping pressure of 5 kg. The mold was placed in a nitrogen oven, and the nitrogen flow rate was 70 L / min. The mold was first purged at room temperature for 30 minutes, and then the temperature was raised to 55 / 80 / 100 degrees according to the preset program of the oven, and each temperature was maintained for 40 minutes to obtain the silicone hydrogel according to Example 2. In this example, 15 parallel experiments were performed, and the silicone hydrogels were all adhered to the female mold 2. The male mold 2 was demolded using the female mold demolding device 20 to obtain the contact lens dry sheet according to Comparative Example 1. The contact lens demolding rate (De-Lens %) was 7%. In other words, in the comparative example, only one contact lens in 15 parallel experiments could be successfully demolded.

[0123] Furthermore, the infrared spectrum of the contact lens dry sheet according to Comparative Example 1 was measured, and the results are shown in Figure 1.

[0124] Furthermore, the modulus of the contact lens dry sheet according to Comparative Example 1 was measured, and the results are shown in Table 1. Figure 12

[0125] The modulus of Examples 1-4 and Comparative Example 1 is shown in Table 2.

[0126] Table 1: Dry sheet modulus of Examples 1-4 and Comparative Example 1

[0127] Number Modulus (MPa) Example 1 141.2 Example 2 150.3 Example 3 121.5 Example 4 116 Comparative Example 1 61

[0128] According to the above table, it can be seen that the dry sheet Young's modulus of Comparative Example 1 without adding 2-hydroxyethyl methacrylate (HEMA) is 61 Mpa, which is more than 50% lower than the modulus of Examples 1-4 with HEMA, and the dry sheet is relatively soft. Therefore, when the dry sheet is extruded and demolded from the male or female mold, the lens is not easy to separate from the polypropylene mold due to the good ductility of the dry sheet, and therefore the demolding rate is very low.

[0129] ​​The formulations of Examples 1-4 added HEMA. Due to the presence of hydroxyl groups on HEMA, it forms hydrogen bonding with the ester bond carbonyl in the polymer system, further improving the mechanical strength of the dry sheet, improving the modulus, and facilitating the release of the sheet.

[0130] The infrared shift of the ester bond carbonyl of Examples 1-4 and Comparative Example 1 is shown in Table 3.

[0131] Table 3 Infrared shift of the ester bond carbonyl of Examples 1-4 and Comparative Example 1

[0132] Number HEMA % -C=0- peak (cm"1) Example 1 16 1723 Example 2 11 1724 Example 3 8 1725 Example 4 5 1725 Comparative Example 1 0 1727

[0133] It can be seen that the formula of Comparative Example 1 without HEMA hydroxyl group, the characteristic vibration of C=O is at 1727 cm-1, and the formula of Examples 1-4 containing HEMA, as the HEMA content increases, the absorption peak shifts from 1727 cm-1 to a shorter wave number (Table 1), and there is a small shoulder peak at 1703 cm-1, which means the presence of hydrogen bonding C=O...H-O. (Zhang Aimin et al., Soft Matter, Issue 4, 2016 also reported DOI: 10.1039 / c5sm02542g).

[0134] The release performance of the contact lenses prepared from the formulations of Examples 5-7 and Comparative Examples 2-3 is shown in Table 4.

[0135] Table 4 Release performance of the contact lenses prepared from the formulations of Examples 5-7 and Comparative Examples 2-3

[0136] Example 5 Example 6 Comparative Example 2 Example 7 Comparative Example 3 MCR-M07 37.9 30 TRIS 10 SIGMA 10 15 PDMS-MA800 25 30 30 VMA 50 50 50 47.4 45 MMA 9 9 9 13.7 18 HEMA 5 5 0 0 6 Vazo-67 0.5 0.5 0.5 0.5 0.5 TEGDMA 0.9 0.9 0.9 0.5 0.5 Total 100.4 105.4 105.4 100 100 de-lens 80％ 85％ 30％ 10％ 100％ OD (mm) 13.26±0.18 13.44±0.26 13.10±0.13 14.3±0.1 14.36±0.11 EWC (%) 47％ 45.80％ 43％ 56.10％ 50.90％ Dk (Barrer) 60 65 62 68 72

[0137] In Table 4, TRIS refers to 3-[tris(trimethylsiloxy)silyl]propyl methacrylate, CAS No. 17096-07-0, SIGMA refers to (3-methacryloyloxy-2-hydroxypropoxy)propyl bis(trimethylsiloxy)methyl, CAS No. 69861-02-5, VMA refers to N-methyl-N-vinylacetamide, MMA refers to methyl methacrylate, HEMA refers to 2-hydroxyethyl methacrylate, Vazo 67 refers to azobis isopentyl nitrile, TEGDMA refers to triethylene glycol dimethacrylate, De-lens% refers to the release rate of the contact lens, OD refers to the outer diameter of the contact lens, EWC(%) refers to the equilibrium water content, and Dk refers to the oxygen permeability coefficient, in bar.

[0138] The hydration process of Examples 5-7 and Comparative Examples 2-3 is as follows: after the contact lenses are released, they are placed in a hydration tray and hydrated with 95% ethanol for 3.0 h, 50% ethanol for 0.5 h, and pure water for 0.5 h x 3 (i.e., the water is changed three times every 0.5 h), during which liquid circulation is performed using a peristaltic pump.

[0139] Example 5

[0140] This example relates to the preparation of a contact lens.

[0141] The experimental procedure of this example is described as follows.

[0142] According to the formulation shown in Table 4, 10 parts by weight of TRIS, 25 parts by weight of PDMS-MA-800, 50 parts by weight of VMA, 9 parts by weight of MMA, 5 parts by weight of HEMA, 0.5 parts by weight of VAZO 67 and 0.9 parts by weight of TEGDMA were mixed to obtain the polymerizable composition according to Example 5.

[0143] The polymerizable composition according to Example 5 was poured into the mold cavity formed by the male and female molds, and the mold was made of polypropylene material with a mold closing pressure of 5 kg. The mold was placed in a nitrogen oven, and the nitrogen flow rate was 70 L / min. The mold was first blown at room temperature for 30 minutes, and then the temperature was raised to 55 / 80 / 100 degrees according to the preset program of the oven, and each temperature was maintained for 40 minutes, to obtain the silicone hydrogel according to Example 5. In this example, 15 parallel experiments were performed, and the silicone hydrogels were all adhered to the female mold 2. The male mold 2 was demolded using the female mold demolding device 20, to obtain the contact lens dry sheet according to Example 5. After hydration, the equilibrium water content and oxygen permeability coefficient were measured, and the results are shown in Table 4.

[0144] Example 6

[0145] This example relates to the preparation of a contact lens.

[0146] The experimental procedure of this example is described as follows.

[0147] According to the formulation shown in Table 4, 10 parts by weight of SIGMA, 30 parts by weight of PDMS-MA-800, 50 parts by weight of VMA, 9 parts by weight of MMA, 5 parts by weight of HEMA, 0.5 parts by weight of VAZO 67 and 0.9 parts by weight of TEGDMA were mixed to obtain the polymerizable composition according to Example 6.

[0148] The polymerizable composition according to Example 6 was poured into the mold cavity formed by the male mold half and the female mold half, the mold was made of polypropylene material, and the mold clamping pressure was 5 kg. The mold was placed in a nitrogen oven, and the nitrogen flow rate was 70 L / min. The mold was first blown at room temperature for 30 minutes, and then the temperature was raised to 55°C / 80°C / 100°C according to the preset program of the oven, and each temperature was maintained for 40 minutes to obtain the silicone hydrogel according to Example 6. In this example, 15 parallel experiments were performed, and the silicone hydrogels were all adhered to the female mold half 2. The male mold half 2 was demolded using the female mold half demolding device 20 to obtain the dry sheet of the contact lens according to Example 6. After hydration, the equilibrium water content and the oxygen permeability coefficient were measured, and the results are shown in Table 4.

[0149] Comparative Example 2

[0150] This example relates to the preparation of a contact lens.

[0151] The experimental steps of this example are described as follows.

[0152] According to the formula shown in Table 4, 15 parts by weight of SIGMA, 30 parts by weight of PDMS-MA-800, 50 parts by weight of VMA, 9 parts by weight of MMA, 0.5 parts by weight of VAZO 67, and 0.9 parts by weight of TEGDMA were mixed to obtain the polymerizable composition according to Comparative Example 2.

[0153] The polymerizable composition according to Comparative Example 2 was poured into the mold cavity formed by the male mold half and the female mold half, the mold was made of polypropylene material, and the mold clamping pressure was 5 kg. The mold was placed in a nitrogen oven, and the nitrogen flow rate was 70 L / min. The mold was first blown at room temperature for 30 minutes, and then the temperature was raised to 55°C / 80°C / 100°C according to the preset program of the oven, and each temperature was maintained for 40 minutes to obtain the silicone hydrogel according to Comparative Example 2. In this example, 15 parallel experiments were performed, and the silicone hydrogels were all adhered to the female mold half 2. The male mold half 2 was demolded using the female mold half demolding device 20 to obtain the dry sheet of the contact lens according to Comparative Example 2. After hydration, the equilibrium water content and the oxygen permeability coefficient were measured, and the results are shown in Table 4.

[0154] Example 7

[0155] This example relates to the preparation of a contact lens.

[0156] The experimental steps of this example are described as follows.

[0157] According to the formula shown in Table 4, 30 parts by weight of MCR-MO7, 45 parts by weight of VMA, 18 parts by weight of MMA, 6 parts by weight of HEMA, 0.5 parts by weight of VAZO 67, and 0.5 parts by weight of TEGDMA were mixed to obtain the polymerizable composition according to Example 7.

[0158] The polymerizable composition according to Example 7 was poured into the mold cavity formed by the male mold half and the female mold half, the mold was made of polypropylene material, and the mold clamping pressure was 5 kg. The mold was placed in a nitrogen oven, and the nitrogen flow rate was 70 L / min. The mold was first purged at room temperature for 30 minutes, and then the temperature was raised to 55°C / 80°C / 100°C according to the preset program of the oven, and each temperature was maintained for 40 minutes to obtain the silicone hydrogel according to Example 7. In this example, 15 parallel experiments were performed, and the silicone hydrogels were all adhered to the female mold half 2. The male mold half 2 was demolded using the female mold half demolding device 20 to obtain the dry sheet of the contact lens according to Example 7. After hydration, the equilibrium water content and the oxygen permeability coefficient were measured, and the results are shown in Table 4.

[0159] Comparative Example 3

[0160] This example relates to the preparation of a contact lens.

[0161] The experimental steps of this example are described as follows.

[0162] According to the formula shown in Table 4, 37.9 parts by weight of MCR-MO7, 47.4 parts by weight of VMA, 13.7 parts by weight of MMA, 0.5 parts by weight of VAZO 67, and 0.5 parts by weight of TEGDMA were mixed to obtain the polymerizable composition according to Comparative Example 3.

[0163] The polymerizable composition according to Comparative Example 3 was poured into the mold cavity formed by the male mold half and the female mold half, the mold was made of polypropylene material, and the mold clamping pressure was 5 kg. The mold was placed in a nitrogen oven, and the nitrogen flow rate was 70 L / min. The mold was first purged at room temperature for 30 minutes, and then the temperature was raised to 55°C / 80°C / 100°C according to the preset program of the oven, and each temperature was maintained for 40 minutes to obtain the silicone hydrogel according to Comparative Example 3. In this example, 15 parallel experiments were performed, and the silicone hydrogels were all adhered to the female mold half 2. The male mold half 2 was demolded using the female mold half demolding device 20 to obtain the dry sheet of the contact lens according to Comparative Example 3. After hydration, the equilibrium water content and the oxygen permeability coefficient were measured, and the results are shown in Table 4.

[0164] Referring to Table 4, by comparing Example 5, Example 6, and Comparative Example 2, it can be seen that when a small molecule siloxane monomer is used and no HEMA is added, the demolding rate of the prepared contact lens is only 10%. However, after adding an appropriate amount of HEMA, the demolding rate, water content, and oxygen permeability of the contact lens are all significantly improved.

[0165] Still referring to Figure 4By comparing Example 7 and Comparative Example 3, it can be seen that when MCR-M07 is used as a monofunctional siloxane monomer and no HEMA is added, the release rate of the contact lens is low and the water content is too high. However, after adding an appropriate amount of HEMA, the release rate of the contact lens is significantly improved, and the water content and oxygen permeability are moderate.

[0166] The above description of the examples is to facilitate the understanding and application of the present application by those of ordinary skill in the art. Those skilled in the art can easily make various modifications to these examples and apply the general principles described herein to other examples without having to pay creative labor. Therefore, the present application is not limited to the examples herein, and improvements and modifications made by those skilled in the art based on the disclosure of the present application without departing from the scope and spirit of the present application are within the scope of the present application.

Claims

1. A silicone hydrogel, characterized in that, The silica hydrogel is prepared by polymerization of a polymerizable composition comprising the following components: (a) A monofunctional siloxane monomer, wherein the monofunctional siloxane monomer is selected from one or more of vinyl monoterminated polysiloxanes, acrylate monoterminated polysiloxanes and methacrylate monoterminated polysiloxanes. (b) Hydrophilic N-vinylamide monomers; (c) Hydrophobic vinyl monomers; (d) A hydroxyl-containing hydrophilic vinyl monomer, wherein the hydroxyl-containing hydrophilic vinyl monomer is a hydroxyalkyl acrylate or a hydroxyalkyl methacrylate; (e) Non-siloxane type vinyl crosslinking agents; (f) Free radical initiators; Wherein, the refractive index of the hydrophobic vinyl monomer is greater than 1.41, and the glass transition temperature of the hydrophobic vinyl monomer is greater than or equal to 60°C. The hydrophobic vinyl monomer is selected from one or more of the following: cyclohexyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, sec-butyl methacrylate, tert-butyl methacrylate, styrene, methylstyrene, 4-tert-butylstyrene, 4-ethoxystyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,5-dimethylstyrene, and acrylates containing benzene rings. The hydroxyl-containing hydrophilic vinyl monomer is selected from one or more of the following: 2-hydroxypropyl methacrylate, N-2-hydroxyethyl (meth)acrylamide, N,N-bis(hydroxyethyl)(meth)acrylamide, N-3-hydroxypropyl (meth)acrylamide, N-2-hydroxypropyl (meth)acrylamide, N-2,3-dihydroxypropyl (meth)acrylamide, N-tris(hydroxymethyl)methyl (meth)acrylamide, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, glyceryl methacrylate, di(ethylene glycol) (meth)acrylate, tri(ethylene glycol) (meth)acrylate, tetra(ethylene glycol) (meth)acrylate, poly(ethylene glycol) (meth)acrylate having a number average molecular weight of up to 1500, and poly(ethylene glycol) ethyl (meth)acrylamide having a number average molecular weight of up to 1500.

2. The silica hydrogel as described in claim 1, characterized in that, On a weight basis, the hydrophobic vinyl monomer accounts for 5% to 20% of the total weight of the polymerizable composition.

3. The silica hydrogel as described in claim 1, characterized in that, On a weight basis, the hydroxyl-containing hydrophilic vinyl monomer accounts for 1-20% of the total weight of the polymerizable composition.

4. The silicone hydrogel as described in claim 3, characterized in that, On a weight basis, the hydroxyl-containing hydrophilic vinyl monomer accounts for 5-10% of the total weight of the polymerizable composition.

5. The silicone hydrogel according to any one of claims 1-4, characterized in that, The monofunctional siloxane monomer is a (meth)acrylic acid-terminated polydimethylsiloxane; The hydrophilic N-vinylamide monomer is selected from one or more of the following: N-methyl-N-vinylacetamide, (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-ethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-propyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-3-methoxypropyl(meth)acrylamide; The non-siloxane type vinyl crosslinker is selected from one or more of the following: ethylene glycol dimethacrylate and triethylene glycol dimethacrylate; The free radical initiator is selected from one or more of the following: peroxide, hydroperoxide, azobis(alkyl- or cycloalkylnitrile), persulfate, percarbonate or mixtures thereof.

6. The silicone hydrogel as described in claim 5, characterized in that, The weight-average molecular weight of the monofunctional siloxane monomer is 600-1000. The acrylate containing a benzene ring includes one or more of phenyl acrylate, phenyl methacrylate, norisoborneol acrylate and norisoborneol methacrylate; The free radical initiators include: benzoyl peroxide, tert-butyl peroxide, tert-amyl peroxybenzoate, 2,2-bis(tert-butylperoxy)butane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, 2,5-bis(tert-butylperoxy)-2,5-dimethyl-3-hexyne, bis(1-(tert-butylperoxy)-1-methylethyl)benzene, and 1,1-bis(tert-butylperoxy)-3,3-... 5-Trimethylcyclohexane, di-tert-butyldisperoxyphthalate, tert-butyl hydroperoxide, tert-butyl peracetate, tert-butyl peroxybenzoate, tert-butyl peroxyisopropyl carbonate, acetyl peroxide, lauroyl peroxide, decanoyl peroxide, dicetyl peroxydicarbonate, di(4-tert-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, tert-butyl peroxyneopentate, tert-butyl peroxy-2-ethylhexanoate, 2,4-pentanedione peroxide, dicumyl peroxide, peracetic acid, potassium persulfate, sodium persulfate, ammonium persulfate, 2,2'-azobis(4-methoxy-2,4-dimethylpentanonitrile), 2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, 2 2,2'-Azobis(2-amidinylpropane) dihydrochloride, 2,2'-Azobis(2,4-dimethylvaleronitrile), 2,2'-Azobis(isobutyronitrile), 2,2'-Azobis-2-methylbutyronitrile, 1,1-Azobis(1-cyclohexanecarboxylonitrile); 2,2'-Azobis(2-cyclopropylpropionitrile), 2,2'-Azobis(methyl isobutyrate), 4,4'-Azobis(4-cyanopentanoic acid), and combinations thereof.

7. A corneal contact lens, characterized in that, The corneal contact lens is made of silicone hydrogel as described in any one of claims 1-6.

8. The method for preparing a corneal contact lens as described in claim 7, characterized in that, The method includes the following steps: S1: A mold is provided that includes a male half mold having a raised molding surface and a female half mold having a recessed molding surface, wherein the male half mold and the female half mold are configured to receive each other, thereby forming a mold cavity between the raised molding surface and the recessed molding surface when the mold is closed. S2: Dispense a predetermined weight of the polymerizable composition into the female half-mold; S3: The male and female half-molds are fitted together to close the mold; S4: The polymerizable composition located in the mold cavity is cured to form a molded corneal contact lens; S5: The mold is separated into a male half-mold and a female half-mold, and the corneal contact lens is adhered to one of the male half-mold and the female half-mold; S6: Squeeze the half-mold with the corneal contact lens attached to it to separate the half-mold from the corneal contact lens; S7: Remove the corneal contact lens from the semi-mold using a vacuum suction device.

9. The method as described in claim 8, characterized in that, The positive and negative half-modes are non-polar, and the positive or negative half-modes can be treated with plasma beam before step S1, so that the corneal contact lens adheres to the plasma-treated positive or negative half-modes.

10. The method as described in claim 8, characterized in that, One of the positive and negative half-molds is polar and the other is non-polar. The corneal contact lens is adhered to either the polar positive half-mold or the polar negative half-mold.

11. The method according to any one of claims 8-10, characterized in that, When the corneal contact lens is adhered to the male half-mold, the squeezing of the half-mold with the corneal contact lens adhered to it includes squeezing the male half-mold in a direction closer to the male half-mold along the radial direction of the male half-mold, so as to deform the raised molding surface of the male half-mold.

12. The method according to any one of claims 8-10, characterized in that, When the corneal contact lens is adhered to the negative half-mold, the squeezing of the half-mold with the corneal contact lens adhered to it includes squeezing the negative half-mold from one side of the negative half-mold toward the corneal contact lens side along the longitudinal direction of the negative half-mold, so as to deform the concave molding surface of the negative half-mold.

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