TW202112861A - Wet-cast molding process for producing contact lens, polymerizable composition for use therein, and anti-uv contact lens produced thereby - Google Patents

Abstract

The present invention relates to a wet-cast molding process for producing a contact lens, and a polymerizable composition for use therein. The invention involves substituting the glycerin solvent used in the conventional wet-cast molding process with a low molecular weight PEG, leading to an increase in the amount of the UV absorber contained in the polymerizable composition, so that the contact lens produced by has an improved UV blocking ability. The invention also relates to a contact lens producible by the wet-cast molding process disclosed herein.

Description

Wet injection molding method for contact lenses, polymerizable composition used in the process, and UV-resistant contact lenses made by the process

The present invention relates to a wet injection molding method for contact lenses and a polymerizable composition used in the manufacturing process. The present invention also relates to anti-ultraviolet contact lenses made by the process and the polymerizable composition.

In recent years, the rapid development of technology products, countless 3C products have greatly changed the past lifestyles, smart phones, tablets, laptops, TVs, the human eye is always from this screen to another screen, and myopia gradually It has become a civilization disease of modern people. As the myopia population increases, the demand for contact lenses also increases. Contact lenses have been widely used for vision correction, and with the advancement of contact lens manufacturing technology, contact lenses of different shapes or colors have also been designed, and new products of corneal color lenses and cosmetic lenses with both correction and beauty have been born. In addition to the breakthrough progress in contact lens materials, the functionality, comfort, and convenience brought by contact lenses will drive growth opportunities in the contact lens market. Contact lenses are no longer just a single purpose for correcting vision, but also The iris discolors or expands the shape of the iris, which makes the eyes look brighter and deeper, and is therefore very popular among female consumers.

Contact lenses can be roughly divided into soft contact lenses and hard contact lenses based on the materials they are made of. Among them, soft disposable contact lenses made of water gel or silicone gel are the mainstream. The manufacturing methods of soft disposable contact lenses can be roughly divided into three types. Lathe cutting is similar to the manufacturing process of hard contact lenses. It involves fixing a cylindrical lens blank (commonly known as a lens button) on an automated lathe, using a diamond knife to turn into a lens with inner and outer curved surfaces, and then proceed After edging and polishing, the lens is immersed in an aqueous buffer for hydration and swelling to obtain the finished lens. Spin casting involves injecting a liquid monomer material into a rotating mold, using the centrifugal force of the mold rotation and the surface tension of the liquid to form a uniform film, and then heating or applying light to solidify the monomer material into a shape, and then hydrate it. Finished lens. Cast molding involves injecting a liquid monomer material into a pre-designed lower mold, then using the corresponding upper mold to press and apply heat or light to solidify the lens, then demold and rehydrate Finished lens. Because the injection molding method has the advantages of fast production, suitable for mass production, low cost, and high lens smoothness yield, the current disposable contact lenses are mostly made by injection molding. The injection molding method can be divided into dry injection molding and wet injection molding. The main difference between the two is that the latter first polymerizes and cures monomers in an environment of hydrophilic solvents such as glycerin, and then hydrates them. As a finished lens, the expansion coefficient of the contact lens can be reduced during the manufacturing process, and it has the advantages of small dimensional variability and precise control of the lens power.

Generally speaking, the level of contact lenses is determined by three indicators: oxygen permeability, moisture retention and UV resistance. As far as anti-ultraviolet light is concerned, because ultraviolet light A (UVA) with a wavelength between 315-380nm and ultraviolet light B (UVB) with a wavelength between 280-315nm may cause damage to the cornea, conjunctiva, retina and lens, The American National Standards Institute (ANSI) and the International Organization for Standardization (ISO) have established standards ANSI Z80.20 (2016) and ISO 18369-2 (2017) for the UV protection of optical lenses. ), among them, those who meet level I must be able to block more than 90% of UVA and more than 99% of UVB, and those who meet level II must be able to block more than 50% of UVA and more than 95% of UVB.

Contact lenses usually achieve the anti-ultraviolet effect by adding UV blocking agents, and the content of the ultraviolet absorber in the lens is roughly proportional to its anti-ultraviolet ability. However, benzotriazoles and benzophenones ultraviolet light absorbers, which are widely used in contact lenses, have extremely high hydrophobicity, which is difficult to be uniform with other highly hydrophilic materials used to make contact lenses. mixing. This leads to the fact that contact lenses can only contain a small amount of ultraviolet light absorber, which is not enough to achieve the desired anti-ultraviolet light level. As a result, commercially available soft contact lenses can only reach anti-ultraviolet light level II at most, but cannot reach anti-ultraviolet light level I. . Although increasing the center thickness of the contact lens can also improve the effect of blocking ultraviolet light, the increase in the thickness of the lens will cause foreign body sensation when wearing it, and cause the oxygen permeability of the lens to decrease, thereby affecting the wearing quality.

Therefore, there is a strong demand in the industry for improving the manufacturing process of soft contact lenses to produce soft contact lenses with a high level of UV resistance.

In order to meet the above-mentioned industrial needs, the inventor of the present case has made great efforts to research and develop the wet injection molding method of soft contact lenses. The inventor of this case noticed that the conventional wet injection molding method for contact lenses uses glycerin as the solvent for the liquid monomer material. Although glycerin is suitable for dispersing highly hydrophilic liquid monomer materials, it cannot dissolve enough ultraviolet light absorbers. The inventor of this case unexpectedly discovered that the use of low molecular weight polyethylene glycol (PEG for short), for example, polyethylene glycol with an average molecular weight of 100 to 800 100 g/mol, was used to replace all or part of the glycerin solvent. It can effectively increase the content of ultraviolet light absorbers, so that the made contact lenses can meet the UV resistance of ANSI Z80.20 (2016) and ISO 18369-2 (2017) grade I without sacrificing oxygen permeability. Light efficiency.

Therefore, according to the first aspect of the present invention, there is provided a polymerizable composition for making contact lenses, which comprises: About 30-40% by weight of the solvent, which contains 75% to 100% by weight of polyethylene glycol based on the total weight of the solvent, and 0% to 25% by weight based on the total weight of the solvent Glycerin, wherein the number average molecular weight of the polyethylene glycol is between 100 g/mole and 800 g/mole; About 0.5~2% by weight of the initiator; About 0.5~1% by weight of crosslinking agent; About 0.8~1.2% by weight of ultraviolet light absorber; and The rest is supplemented with hydrophilic monomers suitable for making contact lenses.

In a preferred embodiment, the polyethylene glycol has a number average molecular weight of about 200 g/mol.

In a preferred embodiment, the solvent contains 100% by weight of polyethylene glycol based on the total weight of the solvent. In another preferred embodiment, the solvent contains up to 25% by weight of glycerin based on the total weight of the solvent, and the remainder is polyethylene glycol.

In a preferred embodiment, the ultraviolet light absorber is selected from the group consisting of benzotriazole ultraviolet light absorbers and benzophenone ultraviolet light absorbers. In a more preferred embodiment, the ultraviolet light absorber contains 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylate (trade name RUVA -93).

In a preferred embodiment, the hydrophilic monomer is selected from hydroxyethyl methacrylate (HEMA), methacrylic acid (MAA), acrylic acid, vinyl alcohol, N-vinylpyrrolidone (NVP), methacrylic acid Glycerides (GMA), diacetone acrylamide (DAA), N,N'-dimethyl acrylamide (DMA), N,N'-diethyl acrylamide, N-isoacrylamide, N -Acrylmorpholine, methacrylamide, silicones (such as methacryloxypropyl tris(trimethylsiloxyalkyl) silane), polyols, isocyanates, their derivatives, and A group formed by their combination. In a more preferred embodiment, the hydrophilic monomer is selected from the group consisting of hydroxyethyl methacrylate (HEMA), N-vinylpyrrolidone (NVP) and methacrylic acid (MAA).

According to a second aspect of the present invention, there is provided a wet injection molding method for manufacturing contact lenses, including the following steps: A female mold and a male mold are provided, wherein the female mold has a concave surface, and the male mold has a convex surface corresponding to the concave surface, and when the female mold is combined with the male mold, a mold for forming the invisible is defined The cavity of the glasses; Injecting the aforementioned polymerizable composition between the female mold and the male mold; Curing the polymerizable composition into the cavity; and The contact lens is made by demolding and hydrating.

Furthermore, according to a third aspect of the present invention, there is provided a contact lens with UV resistance, comprising: A circular arc sheet lens, the lens having a convex surface and a concave surface arranged opposite to each other; The lens is polymerized by hydrophilic monomers and is blended with an ultraviolet light absorber, and the content of the ultraviolet light absorber is sufficient to block more than 90% of UVA and more than 99% of UVB.

Unless otherwise stated, the following terms used in the specification and the scope of the patent application have the following definitions. It should be noted that the indefinite article "a" or "a" used in the specification of this case and the scope of the patent application is intended to mean one or more than one, such as "at least one", "at least two" or "at least three" , And does not just refer to a single one. In addition, the terms "including", "including" and "having" used in the scope of patent application are open-ended terms and do not exclude unmentioned elements. Unless otherwise stated, the term "or" generally encompasses "and/or." The term "about" used throughout the specification and the scope of the patent application is used to describe and represent minor changes that will not substantially affect the essence of the present invention.

The invention relates to a wet injection molding process for contact lenses, and a polymerizable composition suitable for the process.

In the specification of this case, the term "contact lens" is intended to cover soft optical lenses that are mounted on the surface of the eyeball for vision correction, ophthalmological diagnosis, drug delivery, wound healing, and eye color changes. According to the present invention, the "contact lens" is blended with ultraviolet light absorbers to protect the eye tissue of the carrier from ultraviolet light, especially in accordance with ANSI Z80.20 (2016) and ISO 18369-2 (2017) Class I anti-ultraviolet light performance. The soft contact lens is made of water gel. The term "water gel" here refers to a polymer material polymerized by hydrophilic monomers, which can absorb at least 10% by weight of water after being completely hydrated. Preferably, the water content after hydration is 30% by weight or more, more preferably, the water content after hydration is 50% by weight or more, for example, the water content after hydration is about 55% to about 58% by weight. Generally speaking, the higher the water content, the higher the oxygen permeability, and the water content of daily disposable contact lenses is usually above 50% by weight. Typical hydrophilic monomers suitable for forming hydrogels include but are not limited to hydroxyethyl methacrylate (HEMA), methacrylic acid (MAA), acrylic acid, vinyl alcohol, N-vinylpyrrolidone (NVP), glycerol methacrylate (GMA), diacetone acrylamide (DAA), N,N'-dimethyl acrylamide (DMA), N,N'-diethyl acrylamide, N-isoacrylamide, N-propylene Aminomorpholine, methacrylamide, silicones (such as methacryloxypropyl tris(trimethylsiloxyalkyl) silane), polyols, isocyanates, their derivatives, and their The combination. In a preferred embodiment, the contact lens is made of hydroxyethyl methacrylate (HEMA) monomer, N-vinylpyrrolidone (NVP) monomer, or a homopolymer of methacrylic acid (MAA) monomer Or made of copolymer, for example, made of a copolymer of HEMA monomer and MAA monomer, or made of a copolymer of HEMA monomer and NVP monomer.

The polymerizable composition disclosed in this case is roughly in a fluid form, which includes: About 30-40% by weight of the solvent, which contains 75% to 100% by weight of polyethylene glycol based on the total weight of the solvent, and 0% to 25% by weight based on the total weight of the solvent Glycerin, wherein the number average molecular weight of the polyethylene glycol is between 100 g/mole and 800 g/mole; About 0.5~2% by weight of the initiator; About 0.5~1% by weight of crosslinking agent; About 0.8~1.2% by weight of ultraviolet light absorber; and The rest is supplemented with hydrophilic monomers suitable for making contact lenses.

The term "polyethylene glycol" or "PEG" used in this case means a polymer of ethylene oxide, which has the chemical formula H(OCH ₂ CH ₂ ) _n OH and the number average molecular weight (Mn) Between 100 g/mole and 800 g/mole, such as PEG 200, PEG 400 and PEG 600, especially PEG 200. The polyethylene glycol can also be partially chemically modified, such as being capped with a methoxy group to have the chemical formula CH ₃ (OCH ₂ CH ₂ ) _n OH (mPEG for short), and the hydroxyl group at the other end can also be combined with other The functional group may be substituted by other functional groups. According to the present invention, PEG constitutes the main part of the solvent in the polymerizable composition of this case, and is used to disperse other components in the polymerizable composition, especially to uniformly mix the ultraviolet light absorber with other components. In a specific example, the solvent contains 100% by weight of polyethylene glycol based on its total weight, that is, the solvent is entirely composed of polyethylene glycol. In another specific example, in addition to polyethylene glycol, the solvent may also contain up to 25% by weight of glycerin based on its total weight.

The initiator used in the present invention can be any reagent suitable for promoting the polymerization reaction of hydrophilic monomers to form a hydrogel, especially the initiators conventionally used to make soft contact lenses. They can be roughly divided into thermal initiators. Starter or photoinitiator. Typical thermal initiators include, but are not limited to, azobisisoheptanonitrile (ADVN), 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-bis Methyl)valeronitrile, 2,2'-azobis(2-methyl)propionitrile, 2,2'-azobis(2-methyl)butyronitrile, diisopropyl peroxydicarbonate , Laurel peroxide, and benzyl peroxide. Typical photoinitiators include, but are not limited to, phenylbis(2,4,6-trimethylbenzyl) phosphine oxide (trade name Irgacure ^® 819), benzoin methyl ether, 2-hydroxy-2-methyl Phenylpropan-1-one, 1-hydroxycyclohexanone, ethyl 2,4,6-trimethylbenzylphenylphosphonate, and 2,2-diethoxyacetophenone.

The crosslinking agent used in the present invention can be any agent that has at least two polymerizable groups capable of reacting with the functional groups of the hydrogel polymer and is therefore suitable for bridging the hydrogel polymer. Crosslinking agents suitable for making soft contact lenses are well known to those with ordinary knowledge in the relevant technical fields. Typical examples include but are not limited to ethylene glycol dimethacrylate (EGDMA), trimethylolpropane triacrylic acid Esters (TMPTA), tetraethylene glycol dimethacrylate (TEGDMA), triethylene glycol dimethacrylate (TrEGDMA), polyethylene glycol dimethacrylate, trimethylpropane trimethacrylate , Vinyl methacrylate, ethylene diamine dimethyl acrylamide, glyceryl dimethacrylate, triallyl isocyanurate, triallyl cyanurate, and combinations thereof.

。 在另一個具體例中，所述紫外光吸收劑包含一個二苯酮類紫外光吸收劑，例如2-(4-苯甲醯基-3-羥基苯氧基)丙烯酸乙酯 （商品名Cyasorb^® UV-416，可購自於奧瑞奇化學公司），其具有如下結構：

；或是 2,2′,4,4′-四羥基二苯酮，其具有如下結構：

。The ultraviolet absorber used in the present invention can be any ultraviolet absorber suitable for soft contact lenses, which covers the ultraviolet light A (UVA) that can effectively absorb the wavelength between 315-380nm and the wavelength between 280-315nm Ultraviolet B (UVB) compounds and compositions. In some specific examples, the ultraviolet light absorber can even absorb ultraviolet light C (UVC) with a wavelength between 200 and 280 nm. Non-limiting examples of the ultraviolet light absorber include benzotriazoles, benzophenones, triazines, such as benzotriazoles (BTA), 2-[3- (2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylate (2-[3-(2 H -benzotriazol-2-yl)-4-hydroxyphenyl]ethyl methacrylate ), 2-(2'-hydroxy-5'-methacrylamidophenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-methacrylamidophenyl) -5-methoxybenzotriazole, 2-(2'-hydroxy-5'-methacryloxypropyl-3'-tertiary butyl-phenyl)-5-chlorobenzotriazole, 2-hydroxy-benzophenone (2-hydroxy-benzophenone), 2,2′,4,4′-tetrahydroxybenzophenone (2,2′,4,4′-tetrahydroxybenzophenone), 2-(4-benzene 2-(4-benzoyl-3-hydroxyphenoxy)ethyl acrylate (2-(4-benzoyl-3-hydroxyphenoxy)ethyl acrylate), 4-methacryloxy-2-hydroxyphenoxy -2-hydroxybenzophenone) and so on. In a preferred embodiment, the ultraviolet light absorber includes a benzotriazole ultraviolet light absorber, such as 2-[3-(2H-benzotriazol-2-yl)-4-hydroxybenzene Yl]ethyl 2-methacrylate (trade name RUVA-93, available from Otsuka Chemical Co., Ltd.), which has the following structure:

. In another specific example, the ultraviolet light absorber includes a benzophenone ultraviolet light absorber, such as 2-(4-benzyl-3-hydroxyphenoxy) ethyl acrylate (trade name Cyasorb ^® UV-416, available from Orich Chemical Company), which has the following structure:

; Or 2,2',4,4'-tetrahydroxybenzophenone, which has the following structure:

.

The wet injection molding method used in the present invention is substantially the same as the wet injection molding method commonly used in the industry in terms of implementation steps. As shown in Figure 1, the wet injection molding method used to make contact lenses in this case includes the following steps:

Step S01: Provide a female mold 10 and a male mold 20. As shown in FIG. 2, the female mold 10 has a concave surface, and the male mold 20 has a convex surface corresponding to the concave surface. When the female mold 10 and the male mold 20 are combined, they define a cavity for forming the contact lens.

Step S02: The polymerizable composition 30 is injected into the female mold 10, and the male mold 20 and the female mold 10 are combined.

Step S03: Properly heat or irradiate ultraviolet light, so that the polymerizable composition 30 is cured into a lens in the cavity defined by the female mold 10 and the male mold 20.

Step S04: Separate the male mold 20 from the female mold 10, and immerse the lens attached to the male mold 20 or the female mold 10 in an aqueous solution (such as water, physiological saline or other aqueous buffer) to release the lens Then, it is hydrated to produce the contact lens 40.

In this case, 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylate (trade name RUVA-93) was used as a typical ultraviolet light absorber. Under the condition of not substantially changing the type and amount of the initiator, crosslinking agent and hydrophilic monomer in the polymerizable composition, the conventional glycerin solvent is completely or partially replaced with low molecular weight polyethylene glycol, thereby The influence of the solvent in the polymerizable composition on the content of the ultraviolet light absorber was evaluated. Example 1 below shows that the use of low molecular weight polyethylene glycol as a solvent in the hydrophilic polymerizable composition can make the hydrophobic ultraviolet light absorber fully miscible with all components in the composition. As a result, the content of the ultraviolet light absorber in the manufactured contact lens can reach more than 0.8% by weight, which meets the level II ultraviolet protection power set by the ANSI Z80.20 (2016) standard, and can even make the ultraviolet light absorber The content reaches 1.2% by weight, which meets the level I UV protection set by the ANSI Z80.20 (2016) standard. In contrast, as shown in Comparative Example 1, when glycerin is used as a solvent in the same polymerizable composition, the amount of UV absorber dissolved in it is insufficient (less than 0.8% by weight), and it cannot be made into a UV absorber. Contact lenses that meet the ANSI Z80.20 (2016) standard in protection.

Example 2 below further shows that when the polyethylene glycol content in the glycerol-polyethylene glycol solvent system is equal to or higher than 75% by weight based on the total weight of the solvent, that is, at least 25% by weight in the conventional glycerin solvent is When the low molecular weight polyethylene glycol is substituted, the polymerizable composition can be dissolved in a sufficient amount of ultraviolet light absorber to produce contact lenses that meet the ANSI Z80.20 (2016) standard in terms of ultraviolet protection.

Although not wishing to be bound by any theory, we speculate that the conventional glycerin solvent is too hydrophilic and has insufficient solubility for the highly hydrophobic ultraviolet light absorber, so that the ultraviolet light absorber cannot be fully miscible in the polymerizable composition in. In the present invention, low molecular weight polyethylene glycol is used to completely or partially replace glycerin. Because polyethylene glycol has amphoteric properties, it can increase the compatibility between hydrophilic and hydrophobic components. The polymerizable composition is dissolved in a sufficient amount of ultraviolet light absorber to produce contact lenses that meet the ANSI Z80.20 (2016) standard in terms of ultraviolet protection. It is worth noting that with the polymerizable composition and manufacturing method disclosed in this case, contact lenses that meet the grade I set by the ANSI Z80.20 (2016) standard can be produced, which solves an industrial problem that the industry has been unable to overcome for a long time.

Therefore, this case also covers a UV resistant contact lens 40, which includes a circular arc lens, such as the lens has a convex surface 41 and a concave surface 42 opposed to each other, wherein the lens is polymerized by a hydrophilic monomer. It is formed and blended with an ultraviolet light absorber, and the content of the ultraviolet light absorber is sufficient to block more than 90% of UVA and more than 99% of UVB.

The following examples are only used to illustrate the present invention, but not to limit the scope of the present invention.

Comparative Example 1: Using glycerin as a solvent to prepare anti-UV lenses

Prepare a polymerizable composition, which contains about 30-40% by weight of glycerin (available from JT Baker Chemicals Company), about 0.5-2% by weight of Irgacure ^® 819 (available from BASF, Germany), and about 0.5-1% by weight % Ethylene glycol dimethacrylate (EGDMA, purchased from Mitsubishi Chemical Co., Ltd.), 0.4~1.2% by weight of RUVA-93 (purchased from Otsuka Chemical Co., Ltd.), and the rest is hydroxyethyl methacrylate (HEMA) and methacrylic acid (MAA) hydrophilic monomers are supplemented, and then mixed uniformly.

The conventional wet injection molding process is used to prepare the lens. The above-mentioned polymerizable composition is injected into a contact lens mold, and then cured by heat or light reaction, and then demolded by hydration, and the solvent and unreacted monomer are removed at the same time to make a finished product. Finally, a UV-visible spectroscopy system (Agilent 8453 UV-visible Spectroscopy System (Agilent Technologies) / DE9-1602611) was used to detect the lens penetration. The results are shown in Table 1 below.

Table 1-Lens penetration test (the central thickness of the lens at -3.00D is 0.08mm) UV absorber content Visible light (380-780nm) UVA (315-380nm) UVB (280-315nm) UV protection 0.4% 93.56% 38.71% 13.43% ND 0.8% ND ND ND ND 1.2% ND ND ND ND *ND stands for cannot be analyzed or graded

Table 1 shows that when the content of the ultraviolet light absorber is 0.4%, the prepared lens can still maintain the transparency to visible light. However, as the addition ratio of the ultraviolet light absorber increases to more than 0.8% by weight, the polymerizable composition becomes turbid. According to research and judgment, the possible reason is that glycerin has high hydrophilicity and has insufficient solubility for the highly hydrophobic ultraviolet light absorber, so that the ultraviolet light absorber cannot be fully miscible in the polymerizable composition. This comparative example points out that the use of glycerin as a solvent cannot produce lenses that meet the ANSI Z80.20 (2016) standard in terms of UV protection.

Example 1: Using polyethylene glycol as a solvent to prepare anti-UV lenses

Comparative Example 1 was repeated, but polyethylene glycol (average molecular weight 200 g/mol; purchased from PanReac AppliChem) was used as a solvent instead of glycerin in the polymerizable composition. Then, the conventional wet injection molding process is used to make the finished contact lens, and then the lens transmittance is detected by the ultraviolet-visible light spectrometer. The results are shown in Table 2 below.

Table 2 ─ Lens penetration test (the central thickness of the lens at -3.00D is 0.08mm) UV absorber content Visible light (380-780nm) UVA (315-380nm) UVB (280-315nm) UV protection 0.4% 95.17% 32.50% 8.26% ND 0.8% 96.68% 11.00% 1.77% Level II 1.2% 96.06% 3.68% 0.66% Level I *ND stands for cannot be analyzed or graded

Table 2 shows that as the addition ratio of the ultraviolet light absorber increases, the prepared lens still maintains high transmittance to visible light. This indicates that in the polymerizable composition of this example, the hydrophobic ultraviolet light absorber and the hydrophilic monomer have a high degree of compatibility, so all the components in the composition can be fully miscible. Furthermore, the content of the ultraviolet light absorber in the lens is dependent on its ability to resist ultraviolet light, and as the content of the ultraviolet light absorber reaches 1.2% by weight, the prepared lens meets the ANSI Z80.20 (2016) standard The set level I UV protection.

Example 2: Preparation of anti-UV lenses using glycerin-polyethylene glycol mixture as solvent

Prepare a polymerizable composition, which contains about 40% by weight of a mixture of glycerin (available from JT Baker Chemicals Company) and polyethylene glycol (average molecular weight 200 g/mol; from PanReac AppliChem), about 0.5 to 2% by weight of Irgacure ^® 819 (purchased from BASF, Germany), about 0.5 to 1% by weight of ethylene glycol dimethacrylate (EGDMA, purchased from Mitsubishi Chemical Corporation), about 0.8% by weight RUVA-93 (purchased from Otsuka Chemical Co., Ltd.), the rest is made up of hydrophilic monomers of hydroxyethyl methacrylate (HEMA) and methacrylic acid (MAA), and then uniformly mixed.

The conventional wet injection molding process is used to prepare the lens. The above-mentioned polymerizable composition is injected into a contact lens mold, and then cured by heat or light reaction, and then demolded by hydration, and the solvent and unreacted monomer are removed at the same time to make a finished product. Finally, a UV-visible spectroscopy system (Agilent 8453 UV-visible Spectroscopy System (Agilent Technologies) / DE9-1602611) was used to detect the lens penetration. The results are shown in Table 3 below.

Table 3-Lens penetration test (the central thickness of the lens at -3.00D is 0.08mm) Solvent Visible light (380-780nm) UVA (315-380nm) UVB (280-315nm) UV protection PEG200 (40%) 95.50% 12.94% 2.33% Level II PEG200 (30%) + glycerin (10%) 92.14% 15.34% 3.67% Level II PEG200 (20%) + glycerin (20%) 82.32% 35.93% 16.21% ND PEG200 (10%) + glycerin (30%) ND ND ND ND *ND stands for cannot be analyzed or graded

In this embodiment, the addition amount of the ultraviolet light absorber in the polymerizable composition is fixed at 0.8% by weight, and the total addition amount of the solvent is fixed at 40% by weight. The solvent contains polyethylene glycol 10, 20 or 30% by weight based on the total weight of the composition, and glycerin is used to make up to 40% by weight. In addition, the solvent contained only 40% by weight of polyethylene glycol without glycerin as a control group. The experimental results show that the solvent contains only 40% by weight of polyethylene glycol, and the prepared lens meets the level II UV protection set by the ANSI Z80.20 (2016) standard, which is similar to that obtained in Example 1. The results are consistent. When the solvent contains 30% by weight polyethylene glycol and 10% by weight glycerin, the prepared lens can still maintain a high transmittance and effectively block UV absorption. It is presumed that the main reason is that the mixed solvent absorbs ultraviolet light. Although the solubility of the agent has changed slightly, it has no significant effect. However, when the polyethylene glycol content in the mixed solvent is equal to or less than 20% by weight, its hydrophilicity is already too high and the ultraviolet light absorber cannot be completely dissolved, thereby affecting the physical properties of the lens, causing the appearance of the lens to appear foggy and The penetration in the visible light range is significantly reduced.

The above embodiments are only used to illustrate the present invention, but not to limit the present invention. For those with ordinary knowledge in the relevant field, various changes or changes made without departing from the technical scope of the present invention should also fall within the protection category of the present invention. .

10: master model 20: Male model 30: Polymerizable composition 40: contact lenses 41: convex surface 42: concave surface

Figure 1 is a flow chart of the wet injection molding method used to make contact lenses in this case; and

Figure 2 is a schematic diagram of the wet injection molding method used to make contact lenses in this case.

Claims (10)

A polymerizable composition for making contact lenses, which comprises: About 30-40% by weight of the solvent, which contains 75% to 100% by weight of polyethylene glycol based on the total weight of the solvent, and 0% to 25% by weight based on the total weight of the solvent Glycerin, wherein the number average molecular weight of the polyethylene glycol is between 100 g/mole and 800 g/mole; About 0.5~2% by weight of the initiator; About 0.5~1% by weight of crosslinking agent; About 0.8~1.2% by weight of ultraviolet light absorber; and The rest is supplemented with hydrophilic monomers suitable for making contact lenses. The polymerizable composition according to claim 1, wherein the polyethylene glycol has a number average molecular weight of about 200 g/mole. The polymerizable composition according to claim 2, wherein the solvent contains 100% by weight of polyethylene glycol based on the total weight of the solvent. The polymerizable composition according to claim 2, wherein the solvent contains up to 25% by weight of glycerin based on the total weight of the solvent, and the remainder is polyethylene glycol. The polymerizable composition according to claim 1, wherein the ultraviolet light absorber is selected from the group consisting of benzotriazole ultraviolet light absorbers and benzophenone ultraviolet light absorbers. The polymerizable composition according to claim 5, wherein the ultraviolet light absorber comprises 2-[3-(2H-benzotriazol-2-yl)-4-hydroxyphenyl]ethyl 2-methacrylic acid Esters (trade name RUVA-93). The polymerizable composition according to claim 6, wherein the hydrophilic monomer is selected from the group consisting of hydroxyethyl methacrylate (HEMA), methacrylic acid (MAA), acrylic acid, vinyl alcohol, and N-vinylpyrrolidone (NVP). ), glycerol methacrylate (GMA), diacetone acrylamide (DAA), N,N'-dimethyl acrylamide (DMA), N,N'-diethyl acrylamide, N-iso Acrylic amide, N-acrylic morpholine, methacrylamide, silicone (for example, methacryloxypropyl tris(trimethylsiloxyalkyl) silane), polyol, isocyanate, etc. Derivatives of, and groups of their combinations. The polymerizable composition according to claim 7, wherein the hydrophilic monomer is selected from the group consisting of hydroxyethyl methacrylate (HEMA), N-vinylpyrrolidone (NVP) and methacrylic acid (MAA) group. A wet injection molding method for making contact lenses, which includes the following steps: A female mold and a male mold are provided, wherein the female mold has a concave surface, and the male mold has a convex surface corresponding to the concave surface, and when the female mold is combined with the male mold, a mold for forming the invisible is defined The cavity of the glasses; Inject the polymerizable composition according to any one of claims 1 to 8 between the female mold and the male mold; Curing the polymerizable composition into the cavity; and The contact lens is made by demolding and hydrating. An anti-ultraviolet contact lens that can be manufactured by the method described in claim 9, comprising: A circular arc sheet lens, the lens having a convex surface and a concave surface arranged opposite to each other; The lens is polymerized by hydrophilic monomers and is blended with an ultraviolet light absorber, and the content of the ultraviolet light absorber is sufficient to block more than 90% of UVA and more than 99% of UVB.

Images