Durable anti-fog wear-resistant photocureable coating, coating and preparation method thereof

Abstract

The invention provides a durable anti-fog wear-resistant photocureable coating, a coating and a preparation method of the coating. The coating comprises the following components in parts by mass: 5-30 parts of a photocureable monomer, 30-70 parts of photocureable resin and 5-50 parts of a microcapsule coated with a hydrophilic surfactant. The molecular chain end of the light-cured resin contains a plurality of unsaturated carbon-carbon double bonds capable of being cured by ultraviolet light, the light-cured monomer also contains carboxyl and unsaturated carbon-carbon double bonds, and both the carboxyl and the unsaturated carbon-carbon double bonds do not contain hydrophilic soft segments such as polyoxyethylene ether, so that a coating with high crosslinking density is formed to provide excellent wear resistance; the microcapsules coated with the surfactant are uniformly distributed in the compact cross-linked network, and after physical external force is applied or the microcapsules are polluted by organic matters, the microcapsules are broken to release the surfactant, and the surfactant and carboxyl in the photocuring monomer are subjected to ionic interaction, so that the lasting anti-fog performance is exerted.

Description

Technical Field

[0001] This invention belongs to the field of hydrophilic materials technology, specifically relating to a durable, anti-fog, and wear-resistant photocurable coating, coating material, and its preparation method. Background Technology

[0002] Sports goggles, such as swimming goggles, diving masks, and sports safety goggles, are indispensable equipment for sports. However, during daily use, due to changes in temperature and humidity, the lenses are prone to fogging, obstructing the user's vision and affecting the sports experience. To solve this problem, anti-fog coatings for sports goggles were invented. Applying an anti-fog coating to sports goggles effectively prevents fogging, improves the optical transparency of the lenses, and avoids obstructed vision, which is crucial for safety and comfort during sports activities.

[0003] Currently, most anti-fog technologies for sports glasses employ hydrophilic anti-fog coatings, which can be categorized into thermosetting and UV-curing types. While thermosetting anti-fog coatings offer good adhesion, hardness, and scrub resistance, they require long curing times and consume significant energy to evaporate the solvent, resulting in low production efficiency. Furthermore, the substrate is at risk of deformation due to heat. UV-curing anti-fog coatings, on the other hand, can cure instantly under ultraviolet light, making them ideal for continuous industrial production. However, existing UV-curing anti-fog coatings involve directly applying hydrophilic surfactants or mixing them with UV-curing resins before application. The surfactants exist only in a free state within the coating, making them easily rubbed off, affecting anti-fog performance and lifespan. On the other hand, coatings that use large amounts of hydrophilic components to achieve good anti-fog effects typically have poor surface hardness and abrasion resistance, making them easily scratched. Improving surface hardness and abrasion resistance through coating formulation often requires reducing the hydrophilic component content, sacrificing the coating's own hydrophilicity, thus reducing its anti-fog capability.

[0004] Therefore, it is essential to provide a coating that combines wear resistance and anti-fogging properties. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a durable, anti-fogging, and wear-resistant UV-curable coating, its preparation method, and the coating itself. The coating comprises 5-30 parts of a UV-curable monomer, 30-70 parts of a UV-curable resin, and 5-50 parts of microcapsules encapsulated with a hydrophilic surfactant. The UV-curable resin molecular chain ends contain multiple unsaturated carbon-carbon double bonds that can be cured by UV light, and the UV-curable monomer also contains carboxyl groups and unsaturated carbon-carbon double bonds. Neither contains hydrophilic soft segments such as polyoxyethylene ethers, thus exhibiting excellent surface hardness and wear resistance. Upon exposure to physical forces or contamination by organic matter, the microcapsules rupture, releasing the surfactant, which then interacts ionicly with the carboxyl groups in the UV-curable monomer, thereby achieving durable anti-fogging properties.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] The present invention provides a durable, anti-fog, and wear-resistant photocurable coating, which comprises 5-30 parts by weight of photocurable monomer, 30-70 parts by weight of photocurable resin and 5-50 parts by weight of microcapsules coated with hydrophilic surfactant.

[0008] Furthermore, the photocurable monomer is one or more selected from acrylic acid, carboxyethyl 2-acrylate, itaconic acid, itaconic anhydride, maleic acid, and maleic anhydride.

[0009] Furthermore, the functionality of the photocurable resin is less than or equal to 3 and greater than or equal to 10; the photocurable resin includes one or more of Changxing's 6145-100 and 6195-100, and Covestro's Agisyn 230, Agisyn 2421, and Agisyn 2423.

[0010] Furthermore, the hydrophilic surfactant in the microcapsules coated with the hydrophilic surfactant is one or more of betaine-type amphoteric surfactants and amine oxide-type amphoteric surfactants; wherein the betaine-type amphoteric surfactants include cocamidopropyl betaine (CAB), lauramide-propyl betaine (LAB), oleamide-propyl betaine (OAB), and erucamide-propyl betaine (EAB); and the amine oxide-type amphoteric surfactants include cocamidopropyl amine oxide (CAO), lauramide-propyl amine oxide (LAO), oleamide-propyl amine oxide (OAO), and erucamide-propyl amine oxide (EAO).

[0011] This invention also provides a method for preparing the aforementioned durable anti-fog and wear-resistant photocurable coating. The method includes: mixing microcapsules coated with a hydrophilic surfactant with a solvent; after uniform mixing, adding a photocurable monomer and a photocurable resin; and then adding a photoinitiator, a dispersant, a defoamer, and a leveling agent to obtain the durable anti-fog and wear-resistant photocurable coating. The purpose of adding the dispersant is to ensure more uniform dispersion of the microcapsules in the photocurable monomer and photocurable resin, avoiding agglomeration during the coating process. The purpose of the defoamer is to prevent foaming due to solvent evaporation and changes in surface tension during coating. The purpose of the leveling agent is to create a mirror-like effect and avoid uneven surfaces that affect visual appeal.

[0012] Furthermore, the microcapsules coated with hydrophilic surfactants are prepared by the following steps: emulsifying the emulsifier, hydrophilic surfactant, and initiator to obtain a first system; heating the first system and slowly adding methyl methacrylate (MMA) dropwise until the interfacial reaction forms a capsule wall to obtain a second system; cooling the second system and filtering it; washing the resulting filter cake with distilled water, filtering again, and drying to obtain the microcapsules coated with hydrophilic surfactants.

[0013] Specifically, sodium dodecylbenzenesulfonate (SDBS), a hydrophilic surfactant, and azobisisobutyronitrile (AIB) are mixed evenly and emulsified at 40-70℃ and 1000-3000 rpm for 30-60 minutes. Then, the temperature is raised to 70-85℃, and MMA is slowly added dropwise over 1-2 hours. After the addition is complete, the mixture is kept at this temperature for 2-4 hours. After cooling, the reaction solution is filtered, and the filter cake is washed with distilled water and filtered again. This process is repeated three times. Finally, the mixture is dried at 45℃ for 12 hours to obtain polymethyl methacrylate (PMMA)-coated hydrophilic surfactant microcapsules.

[0014] All figures below are by mass fraction. SDBS is 1-5% of the hydrophilic surfactant, azobisisobutyronitrile is about 1% of MMA, and MMA is 20-80% of the hydrophilic surfactant.

[0015] Further, the solvent includes one or more of ethanol, isopropanol, acetone, butanone, diacetone alcohol, dipropylene glycol methyl ether, and water; the dispersant includes any one of TEGO-679, TEGO-689, TEGO-690, TEGO-755W, TEGO-760W, BYK-110, BYK-302, BYK-323, BYK-333, BYK-245, BYK-9010, BYK-995, BYK-306, BYK-2008, and BYK-2009; The defoamer includes any one of BYK-024, BYK-028, BYK-052, and BYK-054; the leveling agent includes any one of TEGO-100, TEGO-270, TEGO-361N, TEGO-450, BYK-310, BYK-346, and BYK-381; the emulsifier includes sodium dodecylbenzenesulfonate; the initiator includes the thermosetting initiator azobisisobutyronitrile; and the photoinitiator includes at least one of the photocuring initiators TPO, BP, 184, and 1173.

[0016] The present invention also provides a durable anti-fog and wear-resistant photocurable coating, which is made from the above-mentioned durable anti-fog and wear-resistant photocurable coating.

[0017] Furthermore, the durable anti-fog and wear-resistant photocurable coating has a spontaneous anti-fog function after being subjected to physical external forces or organic pollution.

[0018] The present invention also provides a method for preparing a durable anti-fog and wear-resistant photocurable coating. The durable anti-fog and wear-resistant photocurable coating obtained by the above-mentioned method is stirred evenly, coated on the surface of a substrate, dried, and then irradiated with UV light to obtain the durable anti-fog and wear-resistant photocurable coating.

[0019] Compared with the prior art, the present invention has the following outstanding effects:

[0020] This invention provides a durable, anti-fog, and wear-resistant UV-curable coating, its preparation method, and a method thereof. Microcapsules encapsulating hydrophilic surfactants are added to a coating formulation composed of a UV-curable resin and a UV-curable monomer. The UV-curable resin contains multiple unsaturated carbon-carbon double bonds that can be cured by UV light, and the UV-curable monomer also contains carboxyl groups and unsaturated carbon-carbon double bonds. Since neither contains hydrophilic soft segments such as polyoxyethylene ethers, a cross-linked network with high hardness and cross-linking density is formed, thus providing excellent wear resistance to the coating. The microcapsules encapsulating the hydrophilic surfactant are uniformly distributed within this dense cross-linked network. When the coating is subjected to physical external force or contaminated by organic matter, the microcapsules rupture, releasing the surfactant, which then interacts ionicly with the carboxyl groups in the UV-curable monomer, making it difficult to be washed away by water and thus providing durable anti-fog performance. This resolves the contradiction between anti-fog durability and wear resistance. Furthermore, the preparation method is simple and suitable for industrial production. Applying the obtained UV-curable coating to sports glasses achieves good and durable anti-fog and wear-resistant effects. Detailed Implementation

[0021] To address the aforementioned issues, this invention utilizes microencapsulation technology to encapsulate hydrophilic surfactants within microcapsules. This technology significantly reduces the hydrophilic component content in the coating, thereby ensuring surface hardness and abrasion resistance. When the coating is damaged by external force, the microcapsules rupture due to stress, releasing the encapsulated hydrophilic surfactants, which then exert their anti-fogging effect. Furthermore, the surfactants interact ionicly with the carboxyl groups in the photocurable monomers, making them less susceptible to water washout and achieving a long-lasting anti-fogging effect. This resolves the conflict between anti-fogging durability and abrasion resistance.

[0022] The present invention will now be described in detail with reference to specific embodiments.

[0023] Example 1: Preparation of microcapsules coated with hydrophilic surfactants

[0024] 0.1 g SDBS, 2 g CAB, and 0.01 g azobisisobutyronitrile were mixed evenly and emulsified at 60 °C and 1000 rpm for 30 min. Then, the temperature was raised to 75 °C, and 1 g MMA was slowly added dropwise over 2 h. After the addition was completed, the mixture was kept at this temperature for 4 h. After cooling, the reaction solution was filtered, and the filter cake was washed with distilled water and filtered again. This process was repeated three times. The mixture was then dried at 45 °C for 12 h to obtain PMMA-coated hydrophilic surfactant microcapsules.

[0025] Example 2: Preparation of microcapsules coated with hydrophilic surfactants

[0026] 0.06 g SDBS, 2 g CAO, and 0.015 g azobisisobutyronitrile were mixed evenly and emulsified at 40 °C and 3000 rpm for 50 min. Then, the temperature was raised to 70 °C, and 1.5 g MMA was slowly added dropwise over 1 h. After the addition was completed, the mixture was kept at this temperature for 3 h. After cooling, the reaction solution was filtered, and the filter cake was washed with distilled water and filtered again. This process was repeated three times. The mixture was then dried at 45 °C for 12 h to obtain microcapsules of PMMA-coated hydrophilic surfactants.

[0027] Example 3: Preparation of microcapsules coated with hydrophilic surfactants

[0028] 0.02 g SDBS, 2 g OAB, and 0.005 g azobisisobutyronitrile were mixed evenly and emulsified at 50 °C and 2000 rpm for 60 min. Then, the temperature was raised to 85 °C, and 0.5 g MMA was slowly added dropwise over 2 h. After the addition was completed, the mixture was kept at this temperature for 3 h. After cooling, the reaction solution was filtered, and the filter cake was washed with distilled water and filtered again. This process was repeated three times. The mixture was then dried at 45 °C for 12 h to obtain microcapsules of PMMA-coated hydrophilic surfactants.

[0029] Example 4: Preparation of microcapsules coated with hydrophilic surfactants

[0030] 0.05 g SDBS, 2 g LAB, and 0.012 g azobisisobutyronitrile were mixed evenly and emulsified at 50 °C and 2000 rpm for 60 min. Then, the temperature was raised to 85 °C, and 1.2 g MMA was slowly added dropwise over 2 h. After the addition was completed, the mixture was kept at this temperature for 3 h. After cooling, the reaction solution was filtered, and the filter cake was washed with distilled water and filtered again. This process was repeated three times. The mixture was then dried at 45 °C for 12 h to obtain microcapsules of PMMA-coated hydrophilic surfactants.

[0031] It should be noted that the number of parts in Examples 5 to 8, as well as Comparative Examples 1 and 2, are all parts by mass.

[0032] Example 5: Preparation of a durable anti-fog and wear-resistant coating

[0033] First, mix 30 parts of the microcapsules from Example 1 with 100 parts of anhydrous ethanol, then add 10 parts of acrylic acid, 60 parts of Agisyn 2421, 3 parts of photoinitiator TPO, 1 part of dispersant BYK-110, 0.5 parts of defoamer BYK-024 and 0.5 parts of leveling agent TEGO-100 to prepare a coating. After stirring evenly, apply it to the surface of a PC substrate. After drying, a durable, anti-fog, and wear-resistant UV-cured coating is obtained after UV irradiation.

[0034] Example 6: Preparation of a durable anti-fog and wear-resistant coating

[0035] First, mix 20 parts of the microcapsules from Example 2 with 300 parts of water, then add 20 parts of itaconic acid, 60 parts of Agisyn230, 3 parts of photoinitiator 184, 1 part of dispersant TEGO-755W, 0.5 parts of defoamer BYK-028 and 0.5 parts of leveling agent TEGO-270 to prepare a coating. After stirring evenly, apply it to the surface of the PC substrate. After drying, a durable, anti-fog, and wear-resistant UV-cured coating is obtained after UV irradiation.

[0036] Example 7: Preparation of a durable anti-fog and wear-resistant coating

[0037] First, mix 30 parts of the microcapsules from Example 3 with 100 parts of diacetone alcohol, then add 30 parts of ethyl carboxylate 2-acrylate, 40 parts of 6195-100, and then add 3 parts of photoinitiator 1173, 1 part of dispersant BYK-333, 0.5 parts of defoamer BYK-054 and 0.5 parts of leveling agent BYK-381 to prepare a coating. After stirring evenly, apply it to the surface of PC substrate. After drying, UV light irradiation will yield a durable, anti-fog, and wear-resistant UV-cured coating.

[0038] Example 8: Preparation of a durable anti-fog and wear-resistant coating

[0039] First, mix 10 parts of the microcapsules from Example 4 with 150 parts of isopropanol, then add 20 parts of ethyl carboxylate 2-acrylate, 70 parts of 6145-100, and then add 3 parts of photoinitiator BP, 1 part of dispersant BYK-2009, 0.5 parts of defoamer BYK-052 and 0.5 parts of leveling agent TEGO-361N to prepare a coating. After stirring evenly, apply it to the surface of PC substrate. After drying, UV light irradiation will yield a durable, anti-fog, and wear-resistant UV-cured coating.

[0040] Comparative Example 1

[0041] First, mix 5 parts CAB and 150 parts water, then add 20 parts ethyl carboxylate 2-acrylate, 75 parts Agisyn 230, 3 parts photoinitiator TPO, 1 part dispersant TEGO-679, 0.5 parts defoamer BYK-028 and 0.5 parts leveling agent TEGO-450 to prepare a coating. After stirring evenly, apply it to the surface of PC substrate. After drying, UV light will be used to obtain a durable, anti-fog and wear-resistant UV-cured coating.

[0042] Comparative Example 2

[0043] First, mix 10 parts CAB and 150 parts water, then add 20 parts ethyl carboxylate 2-acrylate, 70 parts Agisyn 230, 3 parts luminescent initiator 1173, 1 part dispersant BYK-306, 0.5 parts defoamer BYK-052, and 0.5 parts leveling agent BYK-346 to prepare a coating. After stirring evenly, apply it to the surface of a PC substrate. After drying, a durable, anti-fog, and wear-resistant UV-cured coating is obtained after UV irradiation.

[0044] Performance testing

[0045] The antifog coatings prepared in Examples 5-8 were placed at room temperature for 7 days, and their performance was tested according to the test items and methods in Table 1. The results are shown in Table 2.

[0046] Table 1. Performance test items and methods for the antifog coatings prepared in Examples 5-8

[0047]

[0048] Table 2 shows the performance test results of the antifog coatings prepared in Examples 5-8.

[0049] Test performance Example 5 Example 6 Example 7 Example 8 Comparative Example 1 Comparative Example 2 Apparent test No abnormalities No abnormalities No abnormalities No abnormalities It has a white color and oozes oil. It has a white color and oozes oil. Aging test No abnormalities No abnormalities No abnormalities No abnormalities It has a white color and oozes oil. It has a white color and oozes oil. Pencil hardness 1H 2H 1H 2H 2B 3B Adhesion Level 0 Level 0 Level 0 Level 0 Level 0 Level 1 Abrasion resistance test 0 0 1 0 6 15 Anti-fog test ＞300s ＞300s ＞300s ＞300s 10s 90s

[0050] The test results in Table 2 show that if hydrophilic surfactants are not encapsulated in microcapsules and are simply added to the formulation system, the surfactants easily migrate to the coating surface. This not only absorbs moisture from the air, causing surface problems such as whitening and oil seepage, but also affects the strength and adhesion of the coating, making it more prone to loss during daily use and thus resulting in a very short effective anti-fogging time. However, after encapsulation, the surfactants are encapsulated by the shell material, which does not affect the strength and appearance properties, and allows the surfactants to be slowly released within the microcapsules, achieving long-lasting anti-fogging.

[0051] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of the present invention. Any person skilled in the art can make their own modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A durable, anti-fog, and wear-resistant UV-cured coating, characterized in that, The coating comprises 5-30 parts by weight of a UV-curable monomer, 30-70 parts by weight of a UV-curable resin, and 5-50 parts by weight of microcapsules encapsulated with a hydrophilic surfactant.

2. The durable anti-fog and wear-resistant photocurable coating according to claim 1, characterized in that, The photocurable monomer is one or more of acrylic acid, carboxyethyl 2-acrylate, itaconic acid, itaconic anhydride, maleic acid, and maleic anhydride.

3. The durable anti-fog and wear-resistant photocurable coating according to claim 1, characterized in that, The functionality of the photocurable resin is less than or equal to 3 and greater than or equal to 10; The photocurable resin includes one or more of Changxing's 6145-100 and 6195-100, and Covestro's Agisyn 230, Agisyn 2421, and Agisyn 2423.

4. The durable anti-fog and wear-resistant photocurable coating according to claim 1, characterized in that, The hydrophilic surfactant in the microcapsules coated with the hydrophilic surfactant is one or more of betaine-type amphoteric surfactants and amine oxide-type amphoteric surfactants; The betaine-type amphoteric surfactants include cocamidopropyl betaine, lauramidopropyl betaine, oleamidopropyl betaine, and erucamidopropyl betaine. The amine oxide amphoteric surfactants include cocamidopropylamine oxide, lauramide propylamine oxide, oleamide propylamine oxide, and erucic acid amide propylamine oxide.

5. A method for preparing a durable, anti-fog, and wear-resistant photocurable coating as described in any one of claims 1 to 4, characterized in that, The preparation method includes: mixing microcapsules coated with hydrophilic surfactants with solvents, adding photocurable monomers and photocurable resins after the mixture is uniform, and then adding photoinitiators, dispersants, defoamers and leveling agents to obtain the durable anti-fog and wear-resistant photocurable coating.

6. The method for preparing the durable anti-fog and wear-resistant photocurable coating according to claim 5, characterized in that, The microcapsules coated with hydrophilic surfactants are prepared by the following steps: The emulsifier, hydrophilic surfactant and initiator were mixed and then emulsified to obtain the first system; The first system was heated, and methyl methacrylate was slowly added dropwise until the interfacial reaction formed a capsule wall, thus obtaining the second system. After cooling the second system, filter it. The resulting filter cake is washed with distilled water, then filtered and dried to obtain the microcapsules coated with hydrophilic surfactants.

7. The method for preparing the durable anti-fog and wear-resistant photocurable coating according to claim 6, characterized in that, The solvent includes one or more of ethanol, isopropanol, acetone, butanone, diacetone alcohol, dipropylene glycol methyl ether, and water; The dispersant includes any one of TEGO-679, TEGO-689, TEGO-690, TEGO-755W, TEGO-760W, BYK-110, BYK-302, BYK-323, BYK-333, BYK-245, BYK-9010, BYK-995, BYK-306, BYK-2008, and BYK-2009; The defoamer includes any one of BYK-024, BYK-028, BYK-052, and BYK-054; The leveling agent includes any one of TEGO-100, TEGO-270, TEGO-361N, TEGO-450, BYK-310, BYK-346, and BYK-381; The emulsifier includes sodium dodecylbenzenesulfonate; The initiator includes the thermosetting initiator azobisisobutyronitrile; The photoinitiator includes at least one of the photocuring initiators TPO, BP, 184, and 1173.

8. A durable, anti-fog, and wear-resistant photocurable coating, characterized in that, It is prepared from a durable, anti-fog, and wear-resistant photocurable coating as described in any one of claims 1 to 4.

9. The durable anti-fog and wear-resistant photocurable coating according to claim 8, characterized in that, The durable, anti-fog, and wear-resistant photocurable coating has a spontaneous anti-fog function after being subjected to physical external forces or organic pollution.

10. A method for preparing a durable, anti-fog, and wear-resistant photocurable coating, characterized in that, After the durable anti-fog and wear-resistant photocurable coating obtained by the preparation method of the durable anti-fog and wear-resistant photocurable coating as described in claim 5 or 6 is stirred evenly, it is coated on the surface of the substrate, dried, and then irradiated with UV light to obtain the durable anti-fog and wear-resistant photocurable coating.

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