Reactive dyes, process for their manufacture and contact lenses

Abstract

A reactive dye, a manufacturing method thereof, and a contact lens are disclosed. The manufacturing method includes: mixing a hydrophilic molecule and water in a weight ratio of 10:1 to 1:3 to form a co-solvent; adjusting the co-solvent to a pH range with a weak base; and adding a dye to the co-solvent to allow the dye to react with the hydrophilic molecule to form a reaction product containing the reactive dye. The hydrophilic molecule is an acrylic ester having a hydroxyl group. The chemical structure of the dye has a reactive functional group to react with the hydroxyl group of the hydrophilic molecule in the reaction. The reactive functional group of the dye is at least one of a vinyl sulfonate functional group, a sodium sulfonate functional group, and a sulfonate functional group. Thus, the yield of the target product (reactive dye) is effectively improved, and the generation of undesirable by-products is effectively reduced.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a dye, particularly to a reactive dye suitable for use in contact lenses and a method for manufacturing the same, and also to a contact lens. Background Technology

[0002] With the increasing popularity of 3C products such as computers and smartphones, people are spending more and more time using these products every day. However, computers and smartphones emit blue light through their screens, which can affect users' eye health and sleep quality. Therefore, many products with blue light blocking functions have emerged on the market, such as contact lenses that reduce the amount of blue light absorbed by the eyes while wearing them.

[0003] In existing technologies, methods for preparing contact lenses with blue light protection include, for example, adding dyes that absorb blue light to the contact lenses. However, there is a problem with the poor compatibility between the dyes and the raw material compositions used to prepare the contact lenses. The formulated liquid, after being prepared with the dyes and raw material compositions, may separate into layers after a period of time. Alternatively, in water-based adhesive systems, the dyes may be washed out during the hydration process, resulting in the final contact lenses failing to meet the blue light protection standards. This may be because the dyes are poorly compatible with the contact lens raw material compositions, leading to uneven dye dispersion and incomplete bridging.

[0004] The inventors of this application plan to synthesize a dye with a hydrophilic molecule (such as HEMA) to obtain a reactive dye that combines with a hydrophilic molecule. This reactive dye exhibits good compatibility with the hydrophilic component (such as HEMA) in contact lens raw material compositions and is suitable for various formulation systems.

[0005] In the prior art, some related patents are known to propose hydrophilic molecular grafting reactive dyes for use in the formulation of contact lenses. Examples include US Patent Publication No. 8865929 B2 (Applicant - CooperVision) and US Patent Publication No. 7216975B2 (Applicant - Visma).

[0006] US Patent Publication No. US8865929B2 discloses a reactive dye for contact lenses. The specification of this patent discloses a specific method for preparing the reactive dye. A round-bottom flask is pre-dried at 110°C. Hydrophilic hydroxyethyl methacrylate (HEMA) is pre-dried at 170°C using a 3A molecular sieve, and dye RB19, 4-methoxyphenol (MEHQ), dried HEMA (anhydrous conditions), and anhydrous sodium hydroxide or potassium carbonate are added under nitrogen atmosphere. The reaction mixture is stirred at 40°C under nitrogen atmosphere.

[0007] The inventors of this application attempted to synthesize Y15-HEMA under anhydrous conditions according to the method disclosed in US8865929B2, using dye RY15 or dye Y15 as the starting material. After the experiment, the reaction product was analyzed by HPLC and it was found that the desired reactive dye (Y15-HEMA) was not present in the reaction product, and that the reaction product only contained the above-mentioned starting material and the undesirable byproduct (Y15-OH).

[0008] US Patent Publication No. 7216975B2 discloses a method for preparing a reactive dye compound and colored contact lenses. This patent discloses the synthesis reaction of Y15-HEMA, primarily carried out in water. The preparation method includes: using RY15 as a starting material, and pouring RY15, sodium carbonate, and distilled water into a round-bottom flask and stirring thoroughly for 10 minutes to form a reaction liquid; then, heating the reaction liquid to 40°C and reacting for 1 hour; finally, adding approximately 1.5 equivalents of hydrophilic molecules (HEMA) and hydroquinone to the round-bottom flask and stirring to carry out the synthesis reaction of Y15-HEMA, which is carried out at a temperature of 30°C for 24 hours.

[0009] The inventors of this application also attempted to synthesize Y15-HEMA under pure water conditions using the method disclosed in US7216975B2, and used dye RY15 or dye Y15 as the starting material. After the experiment, the reaction product was analyzed by HPLC and it was found that the desired reactive dye (Y15-HEMA) was not present in the reaction product, and that the reaction product only contained the above-mentioned starting material and the undesirable byproduct (Y15-OH).

[0010] The two experiments above show that, regardless of whether dye RY15 or dye Y15 is used as the starting material, it is obviously impossible to obtain the desired reactive dye (Y15-HEMA).

[0011] The inventors of this application hypothesize that Y15-HEMA cannot be obtained under anhydrous conditions because dried hydroxyethyl methacrylate (HEMA) hydrolyzes into methacrylic acid (MAA) and ethylene glycol (EG) under strong alkaline conditions. Since some hydrophilic HEMA molecules hydrolyze into ethylene glycol in an anhydrous solvent environment, the synthesis reaction cannot yield Y15-HEMA, but only Y15-OH.

[0012] The inventors of this application hypothesize that Y15-HEMA cannot be obtained under pure water conditions because, under alkaline conditions of HEMA:pure water at a ratio of 1:40 (i.e., a 2.5% HEMA aqueous solution) and sodium hydroxide, and a reaction at 30°C for 24 hours, HEMA is hydrolyzed. Therefore, the reaction products will only yield Y15 and Y15-OH, and not Y15-HEMA.

[0013] The above hypothesis can be attributed to the findings in the paper "concentration effects in the base-catalyzed hydrolysis of oligo(ethylene glycol)-and amine-containing methacrylic monomers" published in the journal *Designed Monomers and Polymers*: the base-catalyzed hydrolysis rate of esters is directly proportional to the concentration of the ester and hydroxide ions. The rapid hydrolysis of water-soluble hydroxyethyl methacrylate in aqueous solution has been confirmed in a strongly alkaline environment at room temperature. The hydrolysis mechanism can be referenced below. Furthermore, the aforementioned paper also indicates that the hydrolysis rate increases significantly below 20% hydrophilic molecule concentration. In contrast, at higher concentrations, the degree of hydrolysis decreases with decreasing pH.

[0014] [Hydrolysis mechanism]: HEMA + H2O → MAA + EG.

[0015]

[0016] The inventors of this application also tested HEMA with alkali at room temperature or under heating and stirring, based on the aforementioned paper, and indeed obtained hydrolyzed compounds.

[0017] In summary, the synthesis reactions described in US8865929B2 (Cooper Optics) and US7216975B2 (Visionox) both involve the hydrolysis of the hydrophilic molecule HEMA. The synthesis pathways for Cooper Optics and Visionox involve the elimination reaction of RB19 and RY15 to obtain intermediate dyes. Under Cooper Optics' synthesis conditions (anhydrous and strongly alkaline), it is presumed that HEMA will hydrolyze into MAA and EG.

[0018] The presence of both HEMA and EG allows the hydroxyl groups of both compounds to compete for grafting with the ethylene sulfonate functional group of the dye. However, due to the weak electron-withdrawing groups surrounding the hydroxyl groups of HEMA, its synthesis efficiency is slower than that of EG. Cooper's method uses a strong base for the reaction. However, a strong base accelerates the hydrolysis efficiency. Therefore, the final synthesis yields Y15 and a portion of Y15-OH.

[0019] In the pure water reaction conditions of the HEMA, a 1.6% aqueous solution of HEMA is hydrolyzed by most of the water and alkali to ethylene glycol. The aforementioned paper indicates that aqueous solutions containing less than 20% hydrophilic molecules are rapidly hydrolyzed to ethylene glycol. The ethylene glycol then undergoes the oxa-Michael reaction (OMR), thus yielding a greater amount of Y15-OH.

[0020] In other words, the problem of the hydrophilic molecule HEMA being massively hydrolyzed into EG remains unresolved regardless of whether the reaction is carried out under anhydrous conditions at Cooper Optics or under pure water conditions at Visma. Therefore, it is clear that the synthesis reaction using the methods of the two aforementioned patents cannot yield the desired reactive dye (Y15-HEMA), but only the starting material Y15 or the undesirable byproduct (Y15-OH).

[0021] For the purification of the reaction products, US8865929B2 (Cooper Optics) uses column chromatography, which is time-consuming and generates a large amount of solid waste. US7216975B2 (Visionox) uses three extractions with 95% ethanol, resulting in a significant decrease in yield. This purification method yields only about 30% of the product.

[0022] The desired reactive dye (Y15-HEMA) could not be obtained under either anhydrous or pure water conditions. Furthermore, this reactive dye possesses both hydrophilic and lipophilic properties in its structure, giving it better compatibility with specific contact lens formulation systems compared to the hydrophilic structure of the dye (Y15) itself.

[0023] Therefore, recognizing that the aforementioned deficiencies could be improved, the inventors of this application devoted themselves to research and, by applying scientific principles, finally proposed an invention with a reasonable design that effectively improves upon these deficiencies. This solves the problem that the desired reactive dye cannot be obtained under both anhydrous and pure water conditions, and also enables the reaction products to achieve a high yield of the target product. Summary of the Invention

[0024] The technical problem to be solved by the present invention is to provide a method for manufacturing a reactive dye suitable for use in contact lenses, which has a high yield of the target product (reactive dye) to address the shortcomings of the prior art.

[0025] To address the aforementioned technical problems, one technical solution adopted by the present invention is to provide a method for preparing a reactive dye, comprising: a preparation step, which includes: mixing a hydrophilic molecule and water in a weight ratio of 10:1 to 1:3 to form a cosolvent; and adjusting the cosolvent to a pH range using a weak base, wherein the hydrophilic molecule is an acrylic ester having hydroxyl groups; and a synthesis step, which includes: adding a dye to the cosolvent, causing the dye to undergo a synthetic reaction with the hydrophilic molecule to form a reaction product containing the reactive dye; wherein the chemical structure of the dye has a reactive functional group to react with the hydroxyl groups of the hydrophilic molecule in the synthetic reaction; wherein the reactive functional group of the dye is at least one of an ethylene sulfonate functional group, a sodium sulfonate functional group, and a sulfonate functional group.

[0026] Preferably, the weight ratio of hydrophilic molecules to water in the co-solvent is between 9:1 and 1:3.

[0027] Preferably, the pH range is between 8.0 and 10.5.

[0028] Preferably, the hydrophilic molecule is selected from at least one of the group consisting of: hydroxyethyl methacrylate (HEMA), hydroxybutyl 4-acrylate (HBA), glycidyl methacrylate (GMA), hydroxypropyl methacrylate (HPMA), 2-hydroxyisopropyl acrylate (HIPMA), and hydroxybutyl methacrylate (HBMA).

[0029] Preferably, the weak base is at least one of a sodium salt and an ammonium salt.

[0030] Preferably, the sodium salt is selected from at least one of the group consisting of sodium carbonate, sodium bicarbonate, sodium oxalate, sodium acetate, and sodium benzoate; and the ammonium salt is selected from ammonium carbonate.

[0031] Preferably, the hydroxyl group of the hydrophilic molecule is covalently bonded to the reactive functional group of the dye in the synthesis reaction to form the reactive dye; wherein, after the hydroxyl group of the hydrophilic molecule is covalently bonded to the reactive functional group of the dye, an ether group is formed between the hydrophilic molecule and the dye.

[0032] Preferably, the reactive dye has a hydrophilic end and an oleophilic end.

[0033] Preferably, the polymerization reaction temperature is between 50°C and 70°C, and the polymerization reaction time is between 12 hours and 72 hours.

[0034] Preferably, the reaction product is analyzed using high-performance liquid chromatography (HPLC) to determine that the content of the reactive dye in the reaction product is greater than or equal to 30% by weight.

[0035] Preferably, the method for manufacturing the reactive dye further includes a purification step, which comprises: precipitating the reaction product formed by the synthesis reaction with an alcohol solvent and a hydrocarbon solvent to precipitate the reactive dye and form a precipitated product.

[0036] Preferably, the alcohol solvent is an alcohol with a carbon number between C1 and C5, and the hydrocarbon solvent is a hydrocarbon with a carbon number between C4 and C8.

[0037] Preferably, the content of the reactive dye in the precipitated product is greater than or equal to 85% by weight.

[0038] Preferably, the chemical structure of the dye added in the synthesis step is at least one of the following formulas (I) to (VI):

[0039]

[0040]

[0041] This invention also discloses a reactive dye, which is prepared by the reactive dye manufacturing method described above.

[0042] Embodiments of the present invention also disclose a contact lens comprising the reactive dye described above.

[0043] In summary, the beneficial effects of the present invention are that the method for manufacturing reactive dyes provided by the present invention can effectively improve the yield of the target product (reactive dye) and effectively reduce the generation of undesirable byproducts by implementing the following technical solutions: "implementing a configuration step, including: mixing hydrophilic molecules and water in a weight ratio of 10:1 to 1:3 to form a cosolvent; and adjusting the cosolvent to a pH range with a weak base; wherein the hydrophilic molecule is an acrylic ester with hydroxyl groups" and "implementing a synthesis step, including: adding the dye to the cosolvent, causing the dye to undergo a synthesis reaction with the hydrophilic molecule to form a reaction product containing the reactive dye" and "the chemical structure of the dye has a reactive functional group to react with the hydroxyl group of the hydrophilic molecule in the synthesis reaction; wherein the reactive functional group of the dye is at least one of an ethylene sulfonate functional group, a sodium sulfonate functional group, and a sulfonate functional group".

[0044] To further understand the features and technical content of this invention, please refer to the following detailed description and accompanying drawings. However, these descriptions and drawings are only for illustrating the invention and are not intended to limit the scope of protection of the invention in any way. Attached Figure Description

[0045] Figure 1 This is a flowchart illustrating the manufacturing method of the reactive dye according to an embodiment of the present invention.

[0046] Figure 2 The image shows the results of LC-PDA analysis of the reaction products in an embodiment of the present invention.

[0047] Figure 3 The image shows the LC-MS analysis results of the reaction products in an embodiment of the present invention. Detailed Implementation

[0048] The following specific embodiments illustrate the implementation methods disclosed in this invention. Those skilled in the art can understand the advantages and effects of this invention from the content disclosed in this specification. This invention can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of this invention. Furthermore, the accompanying drawings of this invention are for simple illustrative purposes only and are not depictions of actual dimensions; this is stated beforehand.

[0049] The following embodiments will further describe the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of protection of the present invention.

[0050] In this document, in order to describe a specific range of values, the term "from one value to another" is used, which should be interpreted as encompassing any value within the range and the smaller range of values ​​defined by any value within the range, as expressly stated in the specification.

[0051] Furthermore, for the sake of brevity, the structures of polymers or groups in this article are sometimes represented by skeletal formulas, thus omitting the carbon atoms, hydrogen atoms, and carbon-hydrogen bonds in the actual structures. However, when a specific atom or group is explicitly depicted in the structural formula, the depicted structure will be used.

[0052] [Methods for manufacturing reactive dyes]

[0053] The purpose of this invention is to enable the synthesis of hydrophilic molecules and dyes in the presence of a co-solvent to form a reactive dye compound. The manufacturing method provided by this invention effectively improves the yield of the target product (reactive dye) and significantly reduces the generation of unwanted byproducts. Furthermore, some unreacted dye raw materials can participate in the reaction in applications such as contact lens manufacturing. Additionally, the purification method provided by this invention utilizes the polarity difference of the organic solvent to precipitate the product, thereby effectively improving purification efficiency and the recovery rate of the target product.

[0054] like Figure 1 As shown, to achieve the above objectives, the present invention provides a method for manufacturing a reactive dye, comprising steps S110, S120, and S130. It must be noted that the order of the steps and the actual operation method described in the embodiments of the present invention can be adjusted as needed and are not limited to those described in this embodiment.

[0055] Step S110 is a configuration step, which includes: mixing a hydrophilic molecule and water in a weight ratio to form a co-solvent; and adjusting the co-solvent to a pH range using a weak base.

[0056] The hydrophilic molecule is an acrylic ester containing a hydroxyl group. In various embodiments of the present invention, the hydrophilic molecule is selected from at least one of the following materials: hydroxyethyl methacrylate (HEMA), 4-hydroxybutyl acrylate (HBA), glycidyl methacrylate (GMA), hydroxypropyl methacrylate (HPMA), and 2-hydroxyisopropyl acrylate.

[0057] (2-hydroxyisopropyl methacrylate, HIPMA) and hydroxybutyl methacrylate (HBMA). In a preferred embodiment of the invention, the hydrophilic molecule is hydroxyethyl methacrylate.

[0058] The water in the co-solvent can be, for example, pure water, filtered water, distilled water, or electrolyzed water, and is preferably pure water, but the present invention is not limited thereto.

[0059] In the co-solvent, the weight ratio of the hydrophilic molecules to water can be, for example, 10:1 to 1:3, preferably 9:1 to 1:3, and particularly preferably 9:1 to 1:1. In other words, the proportion of the hydrophilic molecules in the co-solvent is approximately 25% to 91%, and preferably 50% to 90%.

[0060] For example, the cosolvent may be prepared by mixing 10 parts by weight of hydrophilic molecules with 1 part by weight of water (the hydrophilic molecules account for approximately 91%). Alternatively, the cosolvent may be prepared by mixing 1 part by weight of hydrophilic molecules with 3 parts by weight of water (the hydrophilic molecules account for approximately 25%), but the present invention is not limited thereto.

[0061] The weak base may be, for example, a sodium salt or an ammonium salt. In various embodiments of the invention, the sodium salt is at least one selected from the group consisting of: sodium carbonate, sodium bicarbonate, sodium oxalate, sodium acetate, and sodium benzoate. The ammonium salt may be, for example, ammonium carbonate. In a preferred embodiment of the invention, the weak base is sodium carbonate or sodium bicarbonate, but the invention is not limited thereto.

[0062] The pH value of the co-solvent, controlled by a weak base, is preferably between 8.0 and 10.5, more preferably between 8.5 and 10.5, and particularly preferably between 9.0 and 10.2. All of these pH ranges result in a weakly alkaline co-solvent.

[0063] Step S120 is a synthesis step, which includes: adding a dye to the cosolvent and causing the dye to undergo a synthesis reaction with a hydrophilic molecule to form a reaction product containing a reactive dye.

[0064] The dye described herein has a chemical structure comprising a chromophore group and a reactive functional group located at at least one end of the chromophore group. In an embodiment of the invention, the reactive functional group is a vinyl sulfonate (CH2=CHSO2-) functional group. In another embodiment of the invention, the reactive functional group is a sodium sulfonate (-SO3Na) functional group or a sulfonic acid group (-SO3) functional group. - Or -SO3H).

[0065] Furthermore, the chromophore has multiple benzene ring structures. The chromophore can have absorption peaks for light in a specific wavelength range. For example, the chromophore of the following chemical formula (I) can have absorption peaks for blue light with wavelengths between 380 nm and 460 nm, but the present invention is not limited thereto.

[0066] In various embodiments of the present invention, the chemical structure of the dye may be, for example, at least one of the following chemical formulas (I) to (VI). These chemical formulas all possess the functional group characteristics described above. However, it should be noted that the dyes listed below are merely illustrative examples, and the dyes of the present invention are not limited to the compounds listed below. Any dye selected that conforms to the chemical functional group characteristics described above is in accordance with the spirit of the present invention and falls within the scope of protection of the present invention.

[0067] [Chemical structure of related dyes]

[0068]

[0069]

[0070] As described above, the hydrophilic molecule is an acrylic ester with hydroxyl (-OH) groups, and the dye has reactive functional groups.

[0071] In the synthetic reaction, the hydroxyl group of the hydrophilic molecule covalently bonds to the reactive functional group of the dye (e.g., ethylene sulfonate or sulfonate functional group) during the reaction, thereby forming the reactive dye. Further, after the hydroxyl group of the hydrophilic molecule covalently bonds to the reactive functional group of the dye, an ether group (RO-R') is formed between the hydrophilic molecule and the dye. For example, in a specific embodiment of the present invention, the hydrophilic molecule is hydroxyethyl methacrylate (HEMA), and the chemical structure of the dye is as shown in the above chemical formula (I). The synthetic reaction is as follows.

[0072]

[0073] In another specific embodiment of the present invention, the hydrophilic molecule is hydroxyethyl methacrylate (HEMA), and the chemical structure of the dye is as described in the above chemical formula (IV). The synthesis reaction is as follows.

[0074]

[0075] The reactive dye (Y15-HEMA) formed by the above synthesis reaction can simultaneously have a hydrophilic end (e.g., sodium sulfonate functional group -SO3Na) and a lipophilic end (e.g., HEMA residues), thus exhibiting better compatibility in special contact lens formulation systems compared to the hydrophilic structure of the dye itself.

[0076] According to the above configuration, the co-solvent contains hydrophilic molecules and water in the aforementioned weight ratio. The co-solvent is adjusted to the aforementioned pH range using a weak base, and the dye has a specific material selection. Accordingly, the manufacturing method provided by this invention, compared to the anhydrous or pure water conditions of prior art, can effectively help improve the yield of the target product (reactive dye) and effectively reduce the generation of undesirable byproducts. The undesirable byproduct (Y15-OH) has the following chemical structure.

[0077] The following is the chemical structure of Y15-OH.

[0078]

[0079] Overall, the initial weight ratios of the components in the synthesis reaction system are as follows: [Dye: Hydrophilic molecule: Pure water: Weak base] weight ratio = 1:2~20:2~20:0.1~0.6.

[0080] In other words, based on 1 part by weight of dye, the amount of hydrophilic molecules added is 2 to 20 parts by weight, the amount of pure water added is 2 to 20 parts by weight, and the amount of weak alkali added is 0.1 to 0.6 parts by weight, but the present invention is not limited thereto.

[0081] In order to improve the efficiency of the above-mentioned synthesis reaction, in some embodiments of the present invention, the weight ratio of hydrophilic molecules to pure water is further limited, that is, the weight ratio of [hydrophilic molecules: pure water] is 10:1 to 1:3, preferably 9:1 to 1:3, and particularly preferably 9:1 to 1:1.

[0082] Furthermore, regarding the reaction conditions of the polymerization reaction, the reaction temperature is preferably between 50°C and 70°C, more preferably between 50°C and 65°C, and particularly preferably between 55°C and 65°C. Additionally, the reaction time is preferably between 12 hours and 72 hours, more preferably between 16 hours and 52 hours, and particularly preferably between 18 hours and 48 hours.

[0083] Furthermore, after completing the synthesis step, a reaction product containing the reactive dye can be obtained. In some embodiments of the present invention, the reaction product is analyzed using high-performance liquid chromatography (HPLC) at a wavelength of 254 nm, and the content of the reactive dye in the reaction product is found to be greater than or equal to 30% by weight, preferably between 30% by weight and 70% by weight, and particularly preferably between 30% by weight and 65% by weight. To improve the purity of the reactive dye in the reaction product, the present invention further provides the following purification step (step S130).

[0084] Step S130 is a purification step, which includes: using alcohol solvents and hydrocarbon solvents to precipitate the reaction product generated by the above synthesis step (step S120), so as to utilize the polarity difference between the alcohol solvents and hydrocarbon solvents to precipitate the reactive dye in the reaction product to form a precipitated product.

[0085] Regarding the type of material, the alcohol solvent may be, for example, an alcohol with a carbon number between C1 and C5, and preferably an alcohol with a carbon number between C1 and C4.

[0086] In various embodiments of the invention, the alcohol solvent is selected from at least one of the group consisting of: methanol, ethanol, n-propanol, isopropanol, and n-butanol.

[0087] Regarding the type of material, the hydrocarbon solvent may be, for example, a hydrocarbon with a carbon number between C4 and C8, and preferably a hydrocarbon with a carbon number between C5 and C7.

[0088] In several embodiments of the invention, the hydrocarbon solvent is selected from at least one of the group consisting of pentane, hexane, and heptane.

[0089] Regarding the amount used, the weight ratio of the alcohol solvent to the hydrocarbon solvent is approximately between 5:1 and 1:5. That is, the weight of the alcohol solvent is between 5 times and 1 / 5 times the weight of the hydrocarbon solvent.

[0090] In the purification step, the weight ratio of the dye to the solvent (alcohol solvent and hydrocarbon solvent) is approximately between 1:20 and 100 to improve the precipitation efficiency of the target product.

[0091] In some embodiments of the present invention, the purification step (step S130) may further include, before precipitating the reaction product using alcohol and hydrocarbon solvents: dehydrating the reaction product; and filtering the reaction product to remove solid impurities; before proceeding with the precipitation operation. It should be noted that the dehydration and filtration operations are not limited to the order described above, and the order of the two operations can be interchanged according to production needs. The dehydration operation may, for example, involve using a dehydrating agent to dehydrate the reaction product, or it may be performed using other physical methods.

[0092] In various embodiments of the present invention, the dehydrating agent may be at least one of, for example, a molecular sieve, sodium sulfate, calcium chloride, and diatomaceous earth, but the present invention is not limited thereto.

[0093] In some embodiments of the present invention, after the purification step (step S130) involves precipitating the reaction product using alcohol and hydrocarbon solvents, it may further include: washing the precipitated product with an ether solvent; then, sequentially filtering and concentrating the precipitated product (e.g., vacuum concentration) to obtain a solid product with high purity. The purity of the purified target product (reactive dye) can be increased to 85% by weight or more.

[0094] The manufacturing method provided by this invention can effectively improve the yield of the target product (reactive dye) and precipitate the product by the polarity difference of the organic solvent, thereby effectively improving the purification efficiency.

[0095] Furthermore, embodiments of the present invention also provide a reactive dye, which is prepared by the above-described method for manufacturing reactive dyes.

[0096] Furthermore, embodiments of the present invention also provide a contact lens comprising the aforementioned reactive dye.

[0097] [Experimental Data and Test Results]

[0098] Hereinafter, the present invention will be described in detail with reference to Examples 1-5 and Comparative Examples 1-3. However, the following examples are only provided to help understand the present invention, and the scope of the present invention is not limited to these examples. Examples 1-5 are to demonstrate that reactive dyes can be obtained in high yield under conditions of co-solvent and specific pH values.

[0099] Example 1: The preparation step involves preparing 18 parts by weight of a hydrophilic molecule and 2 parts by weight of pure water (hydrophilic molecule: pure water = 9:1) to form a cosolvent, and adjusting the pH of the cosolvent to 9.03 with a weak base. The hydrophilic molecule is hydroxyethyl methacrylate (HEMA), and the weak base is sodium carbonate. The synthesis step involves adding 1 part by weight of a dye to the above cosolvent and reacting the dye with the hydrophilic molecule to form a reaction product containing the reactive dye. The dye is selected as the starting material, which is a dye with chemical formula (I) listed above. The reaction temperature of the synthesis reaction is controlled at 55–65°C, and the reaction time is controlled at 18 hours. The reaction product obtained after the reaction was analyzed by HPLC at a wavelength of 254 nm. The content of the reactive dye (Y15-HEMA) in the reaction product was found to be 50.5% by weight, the content of the starting dye (Y15) was 25% by weight, and the content of the byproduct (Y15-OH) was 24.5% by weight. The purification steps included dehydrating the reaction product with a dehydrating agent (molecular sieve); filtering the dehydrated reaction product; then preparing the reaction product with an alcohol solvent and a hydrocarbon solvent to precipitate a product containing high-purity reactive dye; then freezing and allowing the precipitate to stand; then washing with an ether solvent, such as methyl ether, ethyl methyl ether, or ether, and sequentially filtering and concentrating the precipitate (e.g., vacuum concentration) to obtain a high-purity solid product. The purity of the purified target product (reactive dye) can be increased to over 85% by weight.

[0100] The preparation methods of the reactive dyes in Examples 2 to 5 are generally the same as those in Example 1, except for the weight ratio of hydrophilic molecules (HEMA) to pure water in the cosolvent, the type of weak base used, and the pH value of the cosolvent. The reaction conditions and results of Examples 2 to 5 are listed in Table 1 below. The experimental results show that the content of the reactive dye (Y15-HEMA) in the reaction product is greater than 30% by weight, specifically between 34.2% and 60.1% by weight, and preferably between 50.2% and 60.1% by weight.

[0101] Comparative Example 1 was a synthesis reaction under anhydrous conditions (20 parts by weight of hydrophilic molecules and 0 parts by weight of water). Comparative Examples 2 and 3 were synthesis reactions under pure water conditions (0 parts by weight of hydrophilic molecules and 20 parts by weight of water). The dye used in the comparative examples was a dye (RY15) with chemical formula (IV) listed above, which was used as the starting material.

[0102] The reaction product of Comparative Example 1 (under anhydrous conditions) contained 55.7% by weight of the starting dye (RY15) and 44.3% by weight of the byproduct (RY15-OH). The reaction product of Comparative Example 1 did not contain the reactive dye (RY15-HEMA) to be synthesized. This is because the hydrophilic molecule HEMA was hydrolyzed to EG.

[0103] Comparative Example 2 (pure water conditions) used a dye (RY15) with chemical formula (IV). The hydrophilic molecule was added during the synthesis reaction. HPLC analysis revealed that the reaction product of Comparative Example 2 contained 73.9% by weight of dye (Y15), mainly formed by the conversion of RY15, and 3% by weight of byproduct (RY15-OH). The reaction product of Comparative Example 2 contained almost no reactive dye to be synthesized.

[0104] Comparative Example 3 (pure water conditions) used a dye (RY15) with chemical formula (IV). A hydrophilic molecule was added during the synthesis reaction. HPLC analysis revealed that the reaction product of Comparative Example 3 contained 85.7% by weight of a byproduct (RY15-OH), which was mainly formed by the reaction of RY15 with EG produced from the hydrolysis of HEMA. The reaction product of Comparative Example 3 did not contain the reactive dye to be synthesized.

[0105] The experimental results of the above comparative examples 1 to 3 all show that the inventors of this application had the expectation in the prior art to synthesize reactive dyes (RY15-HEMA) under anhydrous and pure water conditions.

[0106] The reaction products were analyzed using high-performance liquid chromatography (HPLC) at a wavelength of 254 nm to determine the content of each component (Y15, Y15-HEMA, Y15-OH). The relevant HPLC analytical conditions are shown in Table 2 below.

[0107] [Table 1 Reaction conditions and results]

[0108]

[0109] [Table 2 HPLC Analysis Conditions]

[0110]

[0111]

[0112] The above experimental results confirm that the method for manufacturing reactive dyes provided by the present invention can effectively solve the problem mentioned in the prior art that the desired reactive dyes cannot be obtained under both anhydrous and pure water conditions.

[0113] The inventors of this application have discovered that co-solvents, by using hydrophilic molecules and water in appropriate proportions, can dissolve basic salts (weak bases) and increase their reactivity. Reactive dyes can be synthesized using dyes. The synthetic reaction can be carried out in a co-solvent environment. Adding a weak base and adjusting the pH value during the synthetic reaction can reduce the problem of byproduct formation. The above technical solution solves the problem that hydrophilic molecules may hydrolyze in anhydrous or pure water environments. Regarding purification, this invention proposes preparing the solvent for precipitating the product using conditions calculated based on Hansen's dissolution parameters, which can purify and increase the yield of the target product by up to 85% by weight or more.

[0114] The synthesized reactive dye possesses both hydrophilic and lipophilic ends, exhibiting excellent compatibility with contact lens raw material compositions and suitability for various formulation systems. After dehydration and filtration, the synthesized product can be directly incorporated into the contact lens manufacturing composition. This is because the product contains both directly usable reactive dyes and reactive dye compounds.

[0115] Regarding the analytical results of the reaction products, Figure 2 The image shows the LC-PDA analysis results of the reaction products in an embodiment of the present invention. Figure 3 This is a chromatogram showing the LC-MS analysis results of the reaction products in an embodiment of the present invention. Figure 2 As shown, signal position 8.411 represents the reactive dye (Y15-HEMA). Signal position 7.578 represents the dye (Y15). Signal position 5.928 represents the byproduct (Y15-OH). Furthermore, Figure 3 It was confirmed that the reactive dye (Y15-HEMA) with a molecular weight of approximately 622+1 was indeed successfully present in the reaction product and had the highest signal intensity.

[0116] It should be noted that, in Examples 1-5 above, although only one or two types of hydrophilic molecules, dyes, and weak bases are used as examples, Examples 1-5 are mainly intended to demonstrate that hydrophilic molecules and dyes can undergo a synthesis reaction in the presence of a co-solvent, and that this reaction can effectively increase the yield of the target product (reactive dye) and effectively reduce the generation of undesirable byproducts within a specific pH range. Therefore, the types of materials used in the components of this invention should not be limited to those in Examples 1-5.

[0117] [Beneficial Effects of the Examples]

[0118] The beneficial effects of this invention are that the method for manufacturing the reactive dye of this invention can effectively improve the yield of the target product (reactive dye) and effectively reduce the generation of undesirable byproducts by implementing the following technical solutions: "implementing a configuration step, including: mixing hydrophilic molecules and water in a weight ratio of 10:1 to 1:3 to form a cosolvent; and adjusting the cosolvent to a pH range with a weak base; wherein the hydrophilic molecules are acrylate esters with hydroxyl groups" and "implementing a synthesis step, including: adding the dye to the cosolvent, causing the dye to undergo a synthesis reaction with the hydrophilic molecules to form a reaction product containing the reactive dye" and "the chemical structure of the dye has a reactive functional group to react with the hydroxyl groups of the hydrophilic molecules in the synthesis reaction; wherein the reactive functional group of the dye is at least one of an ethylene sulfonate functional group, a sodium sulfonate functional group, and a sulfonate functional group".

[0119] The above-disclosed content is only a preferred and feasible embodiment of the present invention, and is not intended to limit the scope of the patent application of the present invention. Therefore, all equivalent technical changes made based on the content of the present invention specification and drawings are included in the scope of the patent application of the present invention.

Claims

1. A method for manufacturing a reactive dye, characterized in that... The method for manufacturing the reactive dye includes: The preparation step includes: mixing hydrophilic molecules and water in a weight ratio of 10:1 to 1:3 to form a cosolvent; and adjusting the cosolvent to a pH range using a weak base; wherein the hydrophilic molecules are acrylates with hydroxyl groups; and The synthesis step includes: adding a dye to the co-solvent, causing the dye to undergo a synthetic reaction with the hydrophilic molecule to form a reaction product containing a reactive dye; The dye has a chemical structure with reactive functional groups to react with the hydroxyl groups of the hydrophilic molecule in the synthesis reaction; the hydrophilic molecule is selected from at least one of the group consisting of: hydroxyethyl methacrylate, hydroxybutyl 4-acrylate, hydroxypropyl methacrylate, 2-hydroxyisopropyl acrylate, and hydroxybutyl methacrylate; and the dye has a chemical structure of at least one of the following formulas (I) and (IV): Formula (I); Formula (IV).

2. The method for manufacturing the reactive dye according to claim 1, characterized in that, The weight ratio of hydrophilic molecules to water in the cosolvent is between 9:1 and 1:

3.

3. The method for manufacturing the reactive dye according to claim 1, characterized in that, The pH range is between 8.0 and 10.

5.

4. The method for manufacturing the reactive dye according to claim 1, characterized in that, The weak base is at least one of a sodium salt and an ammonium salt.

5. The method for manufacturing the reactive dye according to claim 4, characterized in that, The sodium salt is selected from at least one of the group consisting of sodium carbonate, sodium bicarbonate, sodium oxalate, sodium acetate, and sodium benzoate; and the ammonium salt is selected from ammonium carbonate.

6. The method for manufacturing the reactive dye according to claim 1, characterized in that, The hydroxyl group of the hydrophilic molecule is covalently bonded to the reactive functional group of the dye in the synthesis reaction to form the reactive dye; wherein, after the hydroxyl group of the hydrophilic molecule is covalently bonded to the reactive functional group of the dye, an ether group is formed between the hydrophilic molecule and the dye.

7. The method for manufacturing a reactive dye according to claim 1, characterized in that, The reactive dye has a hydrophilic end and an oleophilic end.

8. The method for manufacturing a reactive dye according to claim 1, characterized in that, The reaction temperature of the synthesis reaction is between 50°C and 60°C. o C to 70 o The reaction time of the synthesis reaction is between 12 hours and 72 hours.

9. A method for manufacturing a reactive dye according to any one of claims 1 to 8, characterized in that, The reaction product was analyzed using a high-performance liquid chromatography system, and the content of the reactive dye in the reaction product was found to be greater than or equal to 30% by weight.

10. The method for manufacturing a reactive dye according to claim 1, characterized in that, The method for manufacturing the reactive dye further includes a purification step, which comprises: precipitating the reaction product formed by the synthesis reaction with an alcohol solvent and a hydrocarbon solvent to precipitate the reactive dye and form a precipitated product.

11. The method for manufacturing a reactive dye according to claim 10, characterized in that, The alcohol solvent is an alcohol with a carbon number between C1 and C5, and the hydrocarbon solvent is a hydrocarbon with a carbon number between C4 and C8.

12. The method for manufacturing a reactive dye according to claim 11, characterized in that, The content of the reactive dye in the precipitated product is greater than or equal to 85% by weight.

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