Resin wafer and preparation method thereof

Abstract

The embodiment of the invention discloses a resin wafer and a preparation method thereof. The resin wafer is prepared from the following raw materials in parts by weight: 800 to 980 parts of multifunctional sulfydryl or thiol polymer, 10 to 200 parts of isocyanate, 0.05 to 10 parts of catalyst, 0.02 to 1 part of release agent and 0.1 to 5 parts of anti-UV aging agent.

Description

Technical Field

[0001] The present application belongs to the technical field of resin materials. Specifically, the present application relates to a resin wafer and a preparation method thereof. Background Art

[0002] In the field of electronic consumer products, especially in augmented reality (AR) glasses, wafers, as key optical components, have extremely high requirements for refractive index, usually needing to reach 1.67 or above to ensure an excellent visual experience. Currently, the mainstream material that meets this demand in the market is mainly glass. Although glass materials have excellent optical properties, their inherent physical properties have become a bottleneck in development.

[0003] First, the density and weight of glass are relatively large, which is undoubtedly a considerable burden in electronic consumer products that pursue lightness and portability. Second, the preparation process of high-refractive index glass (such as refractive index 1.7 and higher) is extremely complicated, involving special and expensive raw materials, which directly leads to an increase in production costs, which is unacceptable to the cost-sensitive consumer market.

[0004] In addition, the fragility of glass materials cannot be ignored. Glass materials are fragile and not resistant to falling. Not only is there a high risk of damage in daily use, but it may also shorten the service life of the product, which is also a major obstacle to the popularization and promotion of AR glasses. Summary of the invention

[0005] The purpose of this application is to provide a new technical solution for a resin wafer and a method for preparing the same.

[0006] According to the first aspect of the present application, an embodiment of the present application provides a resin wafer, which comprises the following raw materials calculated by weight:

[0007] 800-980 parts of multifunctional mercapto or thiol polymer, 10-200 parts of isocyanate, 0.05-10 parts of catalyst, 0.02-1 parts of release agent and 0.1-5 parts of anti-UV aging agent.

[0008] Optionally, the multifunctional thiol or thiol polymer includes at least one of 2,2'-[thiobis(methylene)]bisthiobutane, bis-2-methylacryloylethoxydisulfide, 3,5-dimethyl-1,2,4-trithiocyclopentane, 2-mercaptobenzothiazole, 1,5-pentanedithiol, pentaerythritol tetrakis(3-mercaptopropionic acid), 2-mercaptomethyl-1,4-dithiocyclohexane, 2-methacryloylthiomethyl-1,4-dithiocyclohexane, triphenylmethanethiol and 3,4-toluenedithiol.

[0009] Optionally, the isocyanate includes at least one of o-xylylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, toluene-2,4-diisocyanate, isophorone diisocyanate and 2,6-diisopropylphenyl isocyanate.

[0010] Optionally, the catalyst is an organotin catalyst or an amine catalyst.

[0011] Optionally, the organotin catalyst includes at least one of dibutyltin dichloride, dihydroxybutyltin chloride, di-n-butyltin chloride, di-tert-butyltin chloride and dibutyltin diacetate;

[0012] The amine catalyst includes at least one of triethylenediamine, bismorpholinyl diethyl ether and pentamethyldiethylenetriamine.

[0013] Optionally, the release agent includes any one of stearic acid, silicone oil and siloxane release agents.

[0014] Optionally, the anti-UV aging agent includes 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-hydroxy-4

[0015] - any one of n-octyloxybenzophenone, resorcinol monobenzoate and 2-(2'-hydroxy-3',5'-di-tert-phenyl)-5-chlorobenzotriazole.

[0016] Optionally, the resin wafer has a refractive index ≥1.7, a light transmittance ≥87.5%, and a glass transition temperature Tg ≥103°C.

[0017] According to the second aspect of the present application, an embodiment of the present application provides a method for preparing a resin wafer, the preparation method comprising:

[0018] Adding a release agent, a catalyst and an anti-UV aging agent to a multifunctional mercapto or thiol polymer to obtain a mixture I, cooling the mixture I and mixing it with an isocyanate to obtain a mixture II;

[0019] Injecting the mixed material II into a mold;

[0020] The mold is placed in a curing furnace, and the temperature program of the curing furnace is set according to a preset first curing temperature curve for preliminary curing. After cooling, the mold is opened to take out the preliminary cured wafer resin and clean it;

[0021] The cleaned wafer resin is put into the mold again, and placed in a curing furnace to set the temperature program of the curing furnace according to a preset second curing degree curve for secondary curing. After cooling, the mold is opened to take out the resin wafer.

[0022] Optionally, the release agent, catalyst and UV aging resistance agent are added to the multifunctional thiol or thiol polymer to obtain a mixture I, and the mixture I is cooled and mixed with isocyanate to obtain a mixture II, comprising:

[0023] Adding an anti-UV aging agent, a release agent and a catalyst to a multifunctional mercapto or thiol polymer, stirring until the solid is completely dissolved, to obtain a mixture I;

[0024] The mixture I is cooled by cooling circulating water, the temperature of the cooling circulating water is 3°C to 8°C, when the temperature of the mixture I is reduced to 10°C to 15°C, isocyanate is added to the mixture I, stirred and vacuum degassed for 30min to 60min, and then the stirring and degassing are stopped for 10min to 30min;

[0025] Cooling and heat preservation with circulating water at 6°C to 10°C, filtering with a 1μm to 5μm filter screen after depressurization with inert gas to obtain mixed material II, and keeping the mixed material II warm for later use;

[0026] Among them, according to the mass parts: the multifunctional mercapto or thiol polymer is 800-980 parts, the isocyanate is 10-200 parts, the catalyst is 0.05-10 parts, the release agent is 0.02-1.0 parts and the anti-UV aging agent is 0.1-5 parts.

[0027] Optionally, placing the mold in a curing furnace, setting a temperature program of the curing furnace according to a preset first curing temperature curve for preliminary curing, and opening the mold after cooling to take out the preliminary cured wafer resin and clean it, including:

[0028] The mold is placed flat in a curing oven, and the temperature program of the curing oven is set according to a preset first curing temperature curve to perform a first curing. The first curing process includes:

[0029] Keep the temperature at 10℃~20℃ for 1h~3h; increase the temperature to 40℃~60℃, the heating time is 8h~15h; continue to increase the temperature to 70℃~120℃, the heating time is 2h~4h; keep the temperature at 70℃~120℃ for 1h~4h; then cool down to 50℃~70℃, the cooling time is 0.5h~2h;

[0030] After the mold is naturally cooled to room temperature, the mold is opened to take out the initially solidified resin wafer;

[0031] The wafer resin after preliminary curing is trimmed and cleaned.

[0032] Optionally, the cleaned wafer resin is put into the mold again, and placed in a curing furnace to set the temperature program of the curing furnace according to a preset second curing degree curve for secondary curing, and after cooling, the mold is opened to take out the resin wafer, including:

[0033] The curing furnace is heated to 60°C to 80°C, the cleaned wafer resin is placed on one side of the mold, the mold is placed horizontally in the curing furnace, the temperature program of the curing furnace is set according to the second curing temperature curve, and the second curing is performed. The process of the second curing is as follows:

[0034] The curing furnace is heated to 90℃~120℃, and the heating time is 0.5h~1h; the temperature is kept constant at 90℃~120℃ for 1h~5h; then the temperature is lowered to 60℃~70℃, and the cooling time is 0.5h~1h;

[0035] After the mold is naturally cooled to room temperature, the mold is opened and the resin wafer is taken out.

[0036] One beneficial effect of the embodiments of the present application is:

[0037] The resin wafer provided in the embodiment of the present application can effectively improve the refractive index of the resin wafer by introducing a specific type of sulfur-containing organic matter into its raw material to meet the needs of high-end optical devices; the isocyanate used in its raw material can significantly increase the glass transition temperature of the resin wafer and increase its heat resistance.

[0038] Compared with traditional glass wafers, the resin wafer provided by the present application is lighter, which conforms to the development trend of lightweight electronic consumer products and improves the portability and comfort of the product. In addition, the resin wafer of the present application has better drop resistance than glass wafers, is not easy to break, reduces safety hazards during use, and improves product safety.

[0039] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application. DETAILED DESCRIPTION

[0040] Various exemplary embodiments of the present invention will now be described in detail. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0041] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0042] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered as part of the specification.

[0043] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0044] The resin wafer and the preparation method thereof provided in the present application are described in detail below in conjunction with specific embodiments.

[0045] According to one embodiment of the present application, a resin wafer is provided. The resin wafer comprises the following raw materials calculated by weight:

[0046] 800-980 parts of multifunctional mercapto or thiol polymer, 10-200 parts of isocyanate, 0.05-10 parts of catalyst, 0.02-1 parts of release agent and 0.1-5 parts of anti-UV aging agent.

[0047] According to the resin wafer provided in the embodiment of the present application, from the perspective of its raw material components, it includes 800 to 980 parts of multifunctional thiol or thiol polymer. Specifically, the sulfur-containing functional group introduced into the multifunctional thiol or thiol polymer has a high molar refractive index, which helps to significantly improve the refractive index of the resin wafer. The resin wafer provided in the embodiment of the present application can meet the needs of high refractive index (such as 1.7 and above), and is particularly suitable for electronic consumer products such as AR smart glasses that have high requirements for optical properties.

[0048] It should be noted that high molar refractive index refers to the property that the molecules of a substance have a strong ability to change the propagation direction of light waves when light waves pass through it, thus showing a higher refractive index. The refractive index is the ratio of the propagation speed of light in a vacuum to the propagation speed of light in the medium. The molar refractive index is related to factors such as the polarizability of the molecules of the substance and the electron cloud density.

[0049] In the multifunctional thiol or thiol polymer of the present application, sulfur atoms are introduced into the polymer to effectively increase its refractive index due to its large molar refractive index and polarizability. For example, using sulfur-containing organic matter containing complex structures such as benzene rings, long chains and other groups as one of the raw materials of resin wafers can significantly improve its heat resistance while increasing the refractive index. The application of this technology helps to prepare new resin materials that can meet the requirements of high refractive index and have excellent heat resistance.

[0050] The resin wafer provided by the embodiment of the present application also includes isocyanate in its raw material components. The addition of isocyanate and the complex groups (such as benzene rings, long-chain groups, etc.) in the multifunctional thiol or thiol polymer work together to help improve the glass transition temperature (Tg) of the formed resin wafer, thereby giving it excellent high heat resistance. This enables the resin wafer provided by the present application to still maintain stable performance under high temperature conditions and extend the service life of the product.

[0051] The resin wafer provided in the embodiment of the present application also includes a catalyst in its raw material components. The catalyst plays a vital role in the preparation process of the resin wafer.

[0052] Catalysts can reduce the activation energy of chemical reactions, thereby accelerating the reaction rate. In the preparation of resin wafers, a variety of raw materials need to go through chemical processes such as polymerization reactions to form the final product. The addition of catalysts can significantly speed up these reactions and improve production efficiency.

[0053] Catalysts can not only accelerate the reaction rate, but also affect the selectivity of the reaction, making the formation of the target product more favorable. In the preparation of resin wafers, this helps to reduce the formation of by-products and improve the purity and quality of the product.

[0054] The type and amount of catalyst often affect the degree of polymerization of the polymer, that is, the chain length. By selecting the appropriate catalyst and adjusting its amount, the physical properties of the resin wafer, such as hardness and toughness, can be adjusted to meet specific application requirements.

[0055] In the present application, by precisely controlling the use of the catalyst, it is possible to ensure that the resin wafer meets the required physical and chemical performance standards during the preparation process, thereby improving the quality of the final product.

[0056] The resin wafer provided in the embodiment of the present application also includes a release agent (also known as a mold release agent) in its raw material components, which plays the following key roles in the preparation process of the resin wafer:

[0057] (1) Prevent mold sticking: The main function of the release agent is to reduce the adhesion between the resin and the mold surface, ensuring that the resin wafer can be easily demolded from the mold after curing without damaging the wafer surface or the mold itself. This is crucial to maintaining the integrity of the wafer and improving production efficiency.

[0058] (2) Protect the mold: During the curing process of the resin wafer, high temperature and chemical reactions may damage the mold surface. The use of release agent can form a lubricating layer between the mold and the resin, effectively protecting the mold surface and extending the service life of the mold.

[0059] (3) Improving the quality of the prepared resin wafer: The use of release agent can reduce scratches, dents and other defects that may occur in the resin wafer during the demolding process, ensure the surface smoothness and flatness of the resin wafer (or wafer), and thus improve the overall quality of the product.

[0060] In addition, using an easy-to-clean release agent can reduce the difficulty and time of mold cleaning and improve production efficiency.

[0061] In summary, the release agent plays an irreplaceable role in the resin wafer preparation process provided in the present application and is one of the key factors in ensuring the quality and production efficiency of the resin wafer.

[0062] In this example of the present application, the raw material components of the resin wafer also include an anti-UV aging agent, where the anti-UV aging agent is mainly a type of ultraviolet absorber that can absorb ultraviolet rays and convert them into harmless heat energy, thereby preventing ultraviolet rays from damaging the resin wafer.

[0063] Adding an anti-UV aging agent to the raw materials of the resin wafer provided in the present application can effectively extend its service life, which is particularly important in head-mounted display devices (such as AR smart glasses) used outdoors or in high ultraviolet environments.

[0064] In this example of the present application, by adjusting the dosage of the anti-UV aging agent, the performance of the resin wafer can be optimized so that it has stronger anti-ultraviolet ability while maintaining a high refractive index and high heat resistance.

[0065] Resin wafers with enhanced UV resistance have a wider range of applications, especially in outdoor and high UV environments. They can meet the usage requirements of more special scenarios and broaden the market potential of the product.

[0066] In general, the resin wafer provided in the embodiment of the present application can effectively improve the refractive index of the resin wafer by introducing a specific type of sulfur-containing organic matter into its raw materials, thereby meeting the needs of high-end optical devices; and the isocyanate used in its raw materials can significantly increase the glass transition temperature of the resin wafer and increase its heat resistance.

[0067] Compared with traditional glass wafers, the resin wafer provided by the present application is lighter, which conforms to the development trend of lightweight electronic consumer products and improves the portability and comfort of the product. In addition, the resin wafer of the present application has better drop resistance than glass wafers, is not easy to break, reduces safety hazards during use, and improves product safety.

[0068] In some examples of the present application, the multifunctional thiol or thiol polymer includes at least one of 2,2'-[thiobis(methylene)]bisthiobutane, bis-2-methylacryloylethoxydisulfide, 3,5-dimethyl-1,2,4-trithiocyclopentane, 2-mercaptobenzothiazole, 1,5-pentanedithiol, pentaerythritol tetrakis(3-mercaptopropionic acid), 2-mercaptomethyl-1,4-dithiocyclohexane, 2-methacryloylthiomethyl-1,4-dithiocyclohexane, triphenylmethanethiol and 3,4-toluenedithiol.

[0069] In this example of the present application, the multifunctional mercapto or thiol polymer includes a variety of sulfur-containing organic substances with complex structures, such as the above-mentioned 2,2'-[thiobis(methylene)]bis-epoxybutane, bis-2-methylpropyleneethoxydisulfide, 3,5-dimethyl-1,2,4-trithiocyclopentane, 2-mercaptobenzothiazole, 1,5-pentanedithiol, tetrakis(3-mercaptopropionic acid) pentaerythritol ester, 2-mercaptomethyl-1,4-dithiocyclohexane, 2-methacryloylthiomethyl-1,4-dithiocyclohexane, triphenylmethanethiol and 3,4-toluenedithiol. The introduction of these sulfur-containing organic substances helps to improve the refractive index of the resin wafer.

[0070] It should be noted that the multifunctional mercapto or thiol polymer may be used only one of the above examples, or a combination of two or more may be used, preferably a combination of two.

[0071] Sulfur atoms have a large molar refractive index and a high degree of polarizability. Introducing these sulfur-containing functional groups into polymers can effectively increase their refractive index. This is because when light passes through the material, sulfur atoms scatter and absorb less light, allowing light to pass through the material more efficiently, thereby increasing the refractive index. In head-mounted display devices such as AR smart glasses, high refractive index materials are important for reducing the number and size of optical components and reducing the weight of the device.

[0072] In this example of the present application, the complex groups in these multifunctional mercapto or thiol polymers, such as benzene rings, long-chain groups, etc., also help to increase the glass transition temperature (Tg) of the resin, thereby enhancing its heat resistance.

[0073] It should be noted that the glass transition temperature (Tg) is the temperature point at which the material changes from the glass state to the rubber state, and is an important indicator of the material's heat resistance. A higher glass transition temperature means that the material can still maintain good mechanical properties and shape stability at high temperatures, which is especially important for electronic products that need to work in high temperature environments.

[0074] In this example of the present application, the distribution of these sulfur-containing organic compounds in the resin helps to improve the processing properties of the resin. For example, they can reduce the viscosity of the resin and improve the fluidity of the resin, which makes it easier to fill and shape the resin in the subsequent injection mold step. At the same time, these sulfur-containing organic compounds can also inhibit the shrinkage and deformation of the resin in the subsequent curing process to a certain extent, and improve the dimensional accuracy and flatness of the product.

[0075] In this example of the present application, by introducing these multifunctional mercapto or thiol polymers, the interaction between the resin molecular chains can be enhanced, and the crosslinking density and mechanical strength of the resin can be improved. This makes the resin wafer less likely to deform or break when subjected to external forces, thereby improving the stability and reliability of the resin wafer.

[0076] In some examples of the present application, the isocyanate includes at least one of o-xylylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, toluene-2,4-diisocyanate, isophorone diisocyanate and 2,6-diisopropylphenyl isocyanate.

[0077] In this example of the present application, the types of isocyanates mentioned include at least one of o-xylylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, toluene-2,4-diisocyanate, isophorone diisocyanate and 2,6-diisopropylphenyl isocyanate. The technical effects of the introduction of these isocyanates on the preparation of high refractive index and high heat-resistant resin wafers are mainly reflected in the following aspects:

[0078] (1) Improve the cross-linking density of the resin: Isocyanate, as an important cross-linking agent, can react with the active hydrogen atoms in the resin to form stable urea bonds or urethane bonds. The formation of these chemical bonds greatly increases the cross-linking density of the resin, making the resin wafer more compact and strong in structure. High cross-linking density not only enhances the mechanical strength of the resin, but also improves its heat resistance and chemical corrosion resistance.

[0079] (2) Enhanced heat resistance: Since isocyanate reacts with the active groups on the resin molecular chain, a large number of rigid chemical bonds are formed. These chemical bonds remain stable at high temperatures and are not easy to break. Therefore, the introduction of isocyanate can significantly increase the glass transition temperature (Tg) of the formed wafer resin, thereby enhancing its heat resistance.

[0080] (3) Improve processing performance: The right amount of isocyanate can adjust the fluidity and curing speed of the resin. At the same time, by adjusting the type and amount of isocyanate, the curing process parameters of the resin, such as curing temperature and time, can be optimized, further improving processing efficiency and product quality.

[0081] In addition, by selecting different isocyanate types and ratios, the performance indicators of resin wafers can be flexibly adjusted to meet the diverse needs of different application scenarios. For example, for application scenarios that require high heat resistance, isocyanates containing complex groups such as benzene rings can be selected; and for application scenarios that require high transparency, isocyanates without chromophore groups can be selected.

[0082] In summary, the introduction of isocyanate described in the examples of this application has produced significant technical effects on the preparation of high refractive index, high heat-resistant resin wafers, which not only improves the mechanical strength and heat resistance of the resin, but also improves its processing performance and comprehensive performance, meeting the diverse needs of optical display devices for resin wafer materials.

[0083] In some examples of the present application, the catalyst is an organic tin catalyst or an amine catalyst.

[0084] In this example of the present application, it is pointed out that the catalyst used in the principle is an organic tin catalyst or an amine catalyst. In polymer synthesis, the use of these two types of catalysts can effectively promote the reaction between isocyanate and sulfur-containing organic matter, thereby accelerating the curing process of the resin wafer.

[0085] In addition, the use of catalysts makes the resin preparation process more flexible and can be carried out within a wider temperature range, increasing the reliability and stability of production.

[0086] Among them, the organotin catalyst can significantly reduce the reaction temperature of resin curing, shorten the curing time, and thus improve production efficiency.

[0087] Among them, amine catalysts can effectively promote the reaction between isocyanate and sulfur-containing organic matter, thereby promoting the entire curing process. Amine catalysts can enable the resin curing reaction to occur at a lower temperature. Since amine catalysts can accelerate the reaction rate, they also significantly shorten the resin curing time. This is very beneficial for improving production efficiency, reducing production cycle and reducing costs.

[0088] In some examples of the present application, the organic tin catalyst includes at least one of dibutyltin dichloride, dihydroxybutyltin chloride, di-n-butyltin chloride, di-tert-butyltin chloride and dibutyltin diacetate. The amine catalyst includes at least one of triethylenediamine, bismorpholinyl diethyl ether and pentamethyldiethylenetriamine.

[0089] In this example of the present application, the catalyst is at least one of the eight catalysts mentioned above. These catalysts have their own characteristics, but can all effectively promote the curing reaction of the resin.

[0090] According to this example of the present application, a variety of catalysts are described, which achieves selective catalysis. Specifically, different organotin catalysts or amine catalysts may have different catalytic activities for different functional groups in the resin, so a suitable catalyst can be selected as needed to achieve the best catalytic effect.

[0091] By selecting a suitable catalyst, efficient curing reaction can be achieved at a lower temperature, reducing energy consumption while reducing the risk of resin wafer decomposition at high temperatures.

[0092] In addition, the specific type and amount of catalyst can affect the final performance of the resin wafer, such as heat resistance, light transmittance, refractive index, etc., thereby meeting the needs of different application fields.

[0093] In some examples of the present application, the release agent includes any one of stearic acid, silicone oil and siloxane release agents.

[0094] In this example of the present application, it is described that the release agent includes any one of stearic acid, silicone oil and siloxane release agents, which play a key role in the preparation process of the resin wafer. The release agent is mainly used to prevent the formed resin from adhering to the mold, ensuring that the resin can be smoothly demoulded and removed from the mold after curing, while ensuring the surface quality of the formed resin wafer. Selecting a suitable release agent is crucial to improving production efficiency and product quality.

[0095] About Stearic Acid:

[0096] Stearic acid is a saturated fatty acid with good lubricity and mold release properties. Using stearic acid as a release agent can effectively prevent the adhesion between the resin and the mold, making it easy to demold the resin wafer. At the same time, the cost of stearic acid is relatively low, which helps to reduce production costs.

[0097] About silicone oil release agent:

[0098] Silicone oil release agents are release agents with silicone oil as the main component, which have good lubricity and temperature resistance. Silicone oil release agents can remain stable at high temperatures, are not easy to volatilize and decompose, thus ensuring the demoulding performance of the resin wafer during high-temperature curing. In addition, silicone oil release agents can also improve the surface finish of the resin wafer to a certain extent.

[0099] About silicone release agents:

[0100] Silicone release agents are polymers composed of alternating silicon atoms and oxygen atoms, with excellent high and low temperature resistance and chemical stability. Silicone release agents can maintain good demoulding performance at extreme temperatures and are suitable for high-temperature cured resin wafer preparation processes. In addition, their good chemical stability ensures compatibility with resin materials and avoids unnecessary chemical reactions.

[0101] In this application, by selecting a suitable release agent, it can be ensured that the resin wafer can be easily removed from the mold after curing, avoiding losses caused by adhesion. Good demoulding performance helps to maintain the surface finish and shape accuracy of the resin wafer, thereby improving the overall quality of the product.

[0102] In short, in the example provided in this application, the release agents mentioned include stearic acid, silicone oils, siloxanes, etc. These release agents are widely used in the field of resin wafer preparation due to their excellent lubricity and demoulding properties. However, the specific choice of release agent needs to be considered comprehensively based on factors such as resin type, mold material and production process requirements, and this application does not make specific restrictions on this.

[0103] In some examples of the present application, the anti-UV aging agent includes any one of 2-(2'-hydroxy-3', 5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-hydroxy-4-n-octyloxybenzophenone, monobenzoic acid resorcinol ester and 2-(2'-hydroxy-3', 5'-di-tert-phenyl)-5-chlorobenzotriazole.

[0104] The types of anti-UV aging agents are pointed out in this example of the present application. These compounds are all highly efficient ultraviolet absorbers. In this example of the present application, the anti-UV aging agent ingredients listed mainly include five different compounds, each of which has a unique chemical structure and functional properties, and is designed to improve the anti-ultraviolet performance of the resin wafer. The following is a detailed analysis of these materials:

[0105] (1) 2-(2'-Hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole: This compound contains a benzotriazole ring and can effectively absorb ultraviolet rays.

[0106] Due to its special molecular structure, it can efficiently absorb ultraviolet rays and convert them into harmless heat energy for release, thereby protecting the resin wafer from ultraviolet damage; and it has good weather resistance and can maintain stable anti-ultraviolet performance under long-term use.

[0107] (2) 2-(2'-Hydroxy-5'-tert-octylphenyl)benzotriazole: It also contains a benzotriazole ring and has a long-chain alkyl substituent, which helps to improve its solubility and dispersibility in the resin.

[0108] In addition to absorbing ultraviolet rays, it can also provide a certain light stabilization effect to prevent the resin from being degraded by ultraviolet radiation. It has the advantage of good compatibility with the resin substrate and is easy to process and apply.

[0109] (3) 2-Hydroxy-4-octyloxybenzophenone: It contains a benzophenone skeleton, which can absorb ultraviolet rays in the UVA and UVB bands and protect materials from photoaging. It has the advantage of a wide absorption range and is suitable for a variety of ultraviolet environments.

[0110] (4) Monobenzoic acid resorcinol ester: This compound combines the structural characteristics of benzoic acid and resorcinol and has a unique UV absorption mechanism. It not only has the ability to absorb UV rays, but also can synergize with other additives to improve the overall photostability.

[0111] (5) 2-(2'-Hydroxy-3',5'-di-tert-phenyl)-5-chlorobenzotriazole: Similar to the benzotriazole compounds mentioned above, but with different substituents, which give it unique properties. It can absorb ultraviolet rays efficiently and is suitable for applications with high requirements for light stability and thermal stability.

[0112] In summary, the types of anti-UV aging agents mentioned in the examples of this application each have unique chemical structures and functional characteristics, which together improve the anti-ultraviolet performance of the resin wafer. By selecting the appropriate type and dosage of anti-UV aging agents, the comprehensive performance of the resin wafer can be optimized to meet the needs of different application scenarios. At the same time, these anti-UV aging agent ingredients also have good weather resistance and compatibility with the resin substrate, ensuring the stability and reliability of the resin wafer during long-term use.

[0113] In some examples of the present application, the refractive index of the resin wafer is ≥1.7, the transmittance is ≥87.5%, and the glass transition temperature Tg is ≥103°C.

[0114] The resin wafer provided in the present application has a relatively high refractive index, which can reach 1.7 or even higher, and is a high refractive index material.

[0115] Refractive index is one of the important indicators to measure the optical properties of materials, and high refractive index materials have significant advantages in optical applications. In the formula provided in this application, by introducing sulfur-containing organic compounds with high molar refractive index, such as 2,2'-[thiobis(methylene)]bis-epoxybutane, bis-2-methylpropyleneethoxy disulfide, etc., these sulfur-containing functional groups can effectively increase the refractive index of the polymer. At the same time, the use of isocyanates can increase the glass transition temperature of the resin wafer, and these complex structured organic compounds can often have a positive effect on the refractive index.

[0116] The refractive index is ≥1.7, which makes the resin wafer of the present application have performance similar to that of high-refractive-index glass in optical applications, and can meet the demand for high-refractive-index materials in fields such as AR smart glasses, while overcoming the shortcomings of glass materials such as heavy weight and fragility.

[0117] The resin wafer provided in the present application has a relatively high light transmittance, for example, a light transmittance ≥ 87.5%.

[0118] Light transmittance is another important indicator for evaluating the optical properties of transparent materials. High light transmittance means that the material can allow more light to pass through, reduce light loss, and improve imaging quality.

[0119] In this application, the high transmittance of the resin wafer is ensured by carefully controlling the raw material composition and preparation process, such as using anti-UV aging agents to improve the UV resistance of the material, optimizing the mold precision and curing process to reduce internal defects and impurities, etc.

[0120] The setting of transmittance ≥ 87.5% enables the resin wafer to have excellent imaging effects in optical applications, especially in areas such as AR smart glasses that require high definition.

[0121] The resin wafer provided in the present application has a relatively high glass transition temperature, that is, Tg≥103°C.

[0122] Glass transition temperature is an important indicator to measure the heat resistance of materials. In high temperature environment, materials are prone to softening, deformation or even melting, which affects their performance. In this application, organic matter and isocyanate components containing complex groups (such as benzene rings, long-chain groups, etc.) are introduced, and the catalyst is optimized to increase the glass transition temperature of the resin wafer.

[0123] Tg≥103℃ enables the resin wafer to maintain stable physical and chemical properties in a high temperature environment, broadening its application areas. In particular, in head-mounted display devices that require heat resistance (such as AR smart glasses used in high-temperature outdoor environments), the resin wafer can exhibit excellent heat resistance stability.

[0124] The present application provides a resin wafer material that can meet the requirements of high refractive index and high transmittance and has good heat resistance and mechanical properties.

[0125] According to another embodiment of the present application, a method for preparing a resin wafer is provided, and the preparation method includes the following steps S1 to S4.

[0126] Step S1: adding a release agent, a catalyst and an anti-UV aging agent to a multifunctional thiol or thiol polymer to obtain a mixture I, cooling the mixture I and mixing it with an isocyanate to obtain a mixture II;

[0127] Step S2: injecting the mixed material II obtained in step S1 into a mold;

[0128] Step S3: placing the mold in step S2 into a curing furnace, setting the temperature program of the curing furnace according to a preset first curing temperature curve for preliminary curing, opening the mold after cooling, taking out the preliminary cured wafer resin and cleaning it;

[0129] Step S4: Put the cleaned wafer resin obtained in step S3 into the mold again, and place it in a curing furnace to set the temperature program of the curing furnace according to a preset second curing degree curve for secondary curing. After cooling, open the mold and take out the resin wafer.

[0130] According to the above step S1, it can be determined that this step involves mixing the main raw materials. Specifically, by mixing the release agent, catalyst, anti-UV aging agent with the multifunctional mercapto or thiol polymer, it can be ensured that these additives are evenly distributed in the resin, which helps to improve the processing performance and curing effect of the resin. After cooling the mixed mixture I and then mixing it with isocyanate, the reaction rate can be controlled to avoid too fast reaction leading to unstable resin performance. Among them, the addition of isocyanate further improves the heat resistance and glass transition temperature of the resin wafer.

[0131] According to the above step S2, the mixture II prepared in step S1 is injected into the mold.

[0132] The specific operation is, for example: injecting the uniformly mixed mixture II into a mold with high flatness and thickness control accuracy.

[0133] It should be noted that in the preparation process of resin wafers, the selected mold must not only have extremely high flatness, but also its thickness must be precisely controlled to ensure the uniformity of the final product. For this reason, molds made of metal or high-quality glass materials are selected in this application. These materials are not only hard and durable, but also can show better dimensional stability during the processing process. Through fine processing and adjustment, the thickness error of the mold is strictly controlled within 5 microns. This precision ensures that the resin wafer can achieve a better uniform thickness after molding, thereby improving its overall performance.

[0134] Furthermore, in order to ensure that the resin wafer is not disturbed by external impurities during the subsequent curing process and maintain internal purity and consistency, after the mold is set with the required gap, it can be sealed with tape. This step can prevent adverse factors such as air and dust from affecting the resin curing process. At the same time, only one injection port can be retained on the mold to accurately inject the resin raw material.

[0135] Step S3: This step involves the preliminary curing of the resin wafer.

[0136] The operation steps are, for example, placing the mold in step S2 into a curing oven, setting the temperature program of the curing oven according to a preset first curing temperature curve for preliminary curing. After the preliminary curing is completed, the mold is cooled to room temperature, the preliminary cured wafer resin is taken out of the mold, and then cleaned.

[0137] It should be noted that the initial curing transforms the mixture II from liquid to solid, and shapes it into a preset mold shape to ensure the consistency of thickness and flatness. The cleaning step can remove impurities and unreacted products on the surface of the initially cured resin wafer to prepare for secondary curing.

[0138] Step S4: This step involves secondary curing of the resin wafer.

[0139] The operation steps are, for example, to put the wafer resin (preliminarily cured) cleaned in step S3 back into the mold, set the temperature program of the curing furnace according to the preset second curing temperature curve for secondary curing, and after the curing is completed, open the mold and take out the final resin wafer after cooling to room temperature.

[0140] Regarding the secondary curing, it should be noted that the secondary curing further improves the crosslinking density and heat resistance of the resin material, ensuring that the final resin wafer can still maintain stable performance in a high temperature environment. In addition, by optimizing the temperature and time parameters of the secondary curing, the internal stress of the material can be eliminated and the mechanical and optical properties of the resin wafer can be improved.

[0141] In general, based on the preparation method described in the above steps S1 to S4, that is, through raw material mixing, high-precision mold forming and segmented curing process, a resin wafer with high refractive index, high light transmittance and high glass transition temperature can be prepared. This preparation method not only improves the optical performance and heat resistance of the resin wafer, but also ensures the consistency of its thickness and flatness, providing high-quality material selection for optical applications such as AR smart glasses.

[0142] In some examples of the present application, the release agent, catalyst and anti-UV aging agent are added to a multifunctional mercapto or thiol polymer to obtain a mixture I, and the mixture I is cooled and mixed with isocyanate to obtain a mixture II, including the following steps S11 to S13.

[0143] Step S11, adding an anti-UV aging agent, a release agent and a catalyst to a multifunctional mercapto or thiol polymer, stirring until the solid is completely dissolved, to obtain a mixture I;

[0144] Step S12, cooling the mixture I by cooling circulating water, the temperature of the cooling circulating water is 3°C to 8°C, when the temperature of the mixture I drops to 10°C to 15°C, adding isocyanate to the mixture I, stirring and vacuum degassing for 30min to 60min, then stopping stirring and degassing for 10min to 30min;

[0145] Step S13, cooling and keeping warm with circulating water at 6°C to 10°C, and filtering with a 1 μm to 5 μm filter screen after depressurizing with an inert gas to obtain a mixture II, and keeping the mixture II warm for later use;

[0146] Among them, according to the mass parts: the multifunctional mercapto or thiol polymer is 800-980 parts, the isocyanate is 10-200 parts, the catalyst is 0.05-10 parts, the release agent is 0.02-1 parts and the anti-UV aging agent is 0.1-5 parts.

[0147] According to this example of the present application, in step S11, the mixing process of the raw materials is precisely controlled until the solid is completely dissolved, thereby ensuring uniform distribution of all ingredients in the mixture I. This step is crucial for the uniformity of the subsequent curing process and the performance of the final product.

[0148] Wherein, step S1 involves adding an anti-UV aging agent. The addition of the anti-UV aging agent can improve the resistance of the prepared resin wafer to ultraviolet rays. In optical materials, long-term exposure to ultraviolet rays may cause material aging and performance degradation. The anti-UV aging agent can effectively absorb ultraviolet rays, thereby protecting the resin wafer from ultraviolet damage and extending its service life.

[0149] Ultraviolet rays not only affect the appearance color of the material, but may also trigger internal chemical reactions, resulting in changes in material properties. By adding an anti-UV aging agent in step S1, the internal changes caused by ultraviolet rays can be reduced, so that the resin wafer of the present application maintains more stable physical and chemical properties.

[0150] Resin wafers with excellent UV resistance can be used in more UV-sensitive environments, such as outdoor electronic equipment, further broadening the application range of resin wafers.

[0151] In addition, while ensuring the anti-ultraviolet performance, the anti-UV aging agent will basically not significantly affect the transparency of the resin wafer, which is crucial for optical materials. Therefore, the resin wafer after adding the anti-UV aging agent can still maintain good light transmittance.

[0152] In summary, by adding the anti-UV aging agent to the multifunctional mercapto or thiol polymer to form mixture I, the resin wafer preparation method in the example of this application further enhances the material's anti-ultraviolet ability while maintaining the original excellent performance, thereby improving the stability and durability of the product.

[0153] In the above step S12, the mixture I is cooled to a specific temperature range (such as 10°C to 15°C) by cooling the circulating water, and isocyanate is added at this temperature. This temperature control helps to avoid premature reaction of isocyanate with other components in the mixture I at high temperature, thereby ensuring the uniformity of mixing and the controllability of the reaction. At the same time, the vacuum degassing process effectively removes the bubbles generated during the mixing process, further improving the quality of the mixture II.

[0154] After the precisely controlled cooling, mixing, vacuum degassing and cooling and heat preservation process, the mixture II is further optimized in step S13. Specifically, by filtering with a 1μm to 5μm filter, it is ensured that the mixture II does not contain impurities and undissolved solid particles, thereby improving its purity and uniformity. Heat preservation for standby use ensures that the mixture II maintains a stable physical and chemical state during the subsequent curing process.

[0155] The mixture II prepared through the above steps S11 to S13 will show better processing performance in the subsequent curing and molding process. Since the components in the mixture are evenly distributed and have few impurities, the cured resin wafer will have higher light transmittance, better flatness and lower stress level.

[0156] At the same time, the introduction of isocyanate not only increases the cross-linking density of the resin, but also significantly enhances the heat resistance and mechanical properties of the resin wafer. This enables the final product to meet higher standard application requirements, especially in situations where high heat resistance and high strength materials are required.

[0157] In the resin wafer preparation process of the above embodiment, the amount of raw materials used is carefully designed and adjusted to ensure the performance and quality of the final product. The following is a detailed analysis of the amount of raw materials used:

[0158] Multifunctional mercapto or thiol polymer: 800 to 980 parts by mass. This type of polymer is one of the main components of the resin wafer of the present application. It contains multiple active functional groups and can form a cross-linked network during the curing process, giving the resin wafer of the present application excellent performance.

[0159] Isocyanate: The dosage is 10 to 200 parts. As a crosslinking agent, isocyanate can react with the functional groups in multifunctional mercapto or thiol polymers to increase the crosslinking density and heat resistance of the resin. The right amount of isocyanate is the key to ensure that the resin wafer has high strength and high heat resistance.

[0160] Anti-UV aging agent: The dosage is 0.1 to 5 parts. Anti-UV aging agent is mainly used to absorb ultraviolet rays and protect resin wafers from ultraviolet damage. Although the dosage is small, it plays an important role in improving the anti-ultraviolet ability of resin wafers. The right amount of anti-UV aging agent can effectively block the invasion of ultraviolet rays while ensuring light transmittance.

[0161] Catalyst: The dosage is 0.05 to 10 parts. The catalyst accelerates the reaction speed during the resin curing process, helps to reduce the curing temperature, shorten the curing time, etc. The right amount of catalyst can ensure that the resin wafer achieves the ideal curing effect in a shorter time, while avoiding the degradation of optical properties caused by over-curing.

[0162] Release agent: The dosage is 0.02 to 1 part. The release agent is mainly used to prevent the resin from sticking to the mold and facilitate the demoulding of the resin wafer after curing. The right amount of release agent can ensure a smooth demoulding process after curing and avoid damage to the surface of the resin wafer.

[0163] In summary, the dosage of raw materials in this application is carefully designed according to the performance requirements and processing conditions of the resin wafer. By adjusting the dosage ratio of each raw material, the performance of the resin wafer can be accurately controlled to meet the application requirements of different fields. At the same time, reasonable raw material dosage also helps to reduce production costs and improve production efficiency.

[0164] In some examples of the present application, the mold is placed in a curing furnace, the temperature program of the curing furnace is set according to a preset first curing temperature curve for preliminary curing, and after cooling, the mold is opened to take out the preliminary cured wafer resin and clean it, including the following steps S31 and S33.

[0165] Step S31, placing the mold flat in a curing oven, setting the temperature program of the curing oven according to a preset first curing temperature curve, and performing a first curing, and the first curing process includes:

[0166] Keep the temperature at 10℃~20℃ for 1h~3h; increase the temperature to 40℃~60℃, the heating time is 8h~15h; continue to increase the temperature to 70℃~120℃, the heating time is 2h~4h; keep the temperature at 70℃~120℃ for 1h~4h; then cool down to 50℃~70℃, the cooling time is 0.5h~2h;

[0167] Step S32, opening the mold after the mold is naturally cooled to room temperature, and taking out the resin wafer after preliminary solidification;

[0168] Step S33, trimming and cleaning the wafer resin after preliminary curing.

[0169] In this example of the present application, the initial curing process of the wafer resin is achieved through a series of carefully designed temperature control steps, which not only ensure the uniform curing of the resin, but also significantly improve the performance of the final product, the resin wafer.

[0170] According to the above step S31, a combination of multi-stage heating and constant temperature control is adopted. Specifically, the initial curing process is divided into multiple stages, including low temperature constant temperature, gradual heating, high temperature constant temperature and cooling. This multi-stage temperature control helps the resin to cure evenly in different temperature ranges, avoiding the problem of uneven curing caused by excessive temperature difference.

[0171] Among them, low-temperature constant temperature treatment at 10°C to 20°C for 1h to 3h is helpful for the initial fusion and uniform distribution of the resin raw materials, laying the foundation for the subsequent curing reaction.

[0172] Subsequently, the resin is gradually cured in different temperature ranges by gradually increasing the temperature (i.e., increasing the temperature to 40°C ~ 60°C for 8h ~ 15h; continuing to increase the temperature to 70°C ~ 120°C for 2h ~ 4h). This gradual curing process is beneficial for the molecular chains inside the resin to slowly adjust their positions, reducing the internal stress caused by rapid curing, thereby improving the dimensional stability and optical properties of the resin wafer.

[0173] In the preparation method of the present application, through precise temperature control, defects such as bubbles and cracks generated in the resin wafer during the curing process can be reduced, thereby improving the yield and quality of the product.

[0174] The preliminary curing process in this application, see step S31, helps maintain the flatness of the resin wafer surface and reduces the unevenness caused by uneven curing. At the same time, the reduced internal stress and defects also help to improve the light transmittance of the product, making it perform better in optical applications.

[0175] The multi-stage curing process helps to fully cross-link the resin molecular chains, improve the heat resistance and mechanical strength of the resin wafer, and enable it to maintain stable performance in high temperature environments.

[0176] Although the initial curing process takes a long time, precise temperature control can ensure that the resin is fully cured in the curing oven, reducing rework caused by insufficient curing, thereby improving overall production efficiency and yield rate.

[0177] The resin wafer after initial curing has good dimensional stability and certain mechanical strength, providing a good foundation for subsequent secondary curing and other processing processes.

[0178] Cleaning can remove impurities on the surface of the resin wafer after preliminary curing, residues of raw materials that have not been completely reacted, and byproducts that may be produced during the curing process. If these impurities and residues remain on the surface of the resin wafer, they may affect the subsequent processing performance and the performance of the final product.

[0179] In some examples of the present application, the cleaned wafer resin is put into the mold again, and placed in a curing furnace to set the temperature program of the curing furnace according to a preset second curing degree curve for secondary curing. After cooling, the mold is opened to take out the resin wafer, including the following steps S41 and S42.

[0180] Step S41, raising the temperature of the curing furnace to 60°C to 80°C, placing the cleaned wafer resin on one side of the mold, placing the mold horizontally in the curing furnace, setting the temperature program of the curing furnace according to the second curing temperature curve, and performing the second curing, and the process of the second curing is as follows:

[0181] The curing furnace is heated to 90℃~120℃, and the heating time is 0.5h~1h; the temperature is kept constant at 90℃~120℃ for 1h~5h; then the temperature is lowered to 60℃~70℃, and the cooling time is 0.5h~1h;

[0182] Step S42: After the mold is naturally cooled to room temperature, the mold is opened to take out the resin wafer.

[0183] In the preparation process of resin wafers, secondary curing is an important step, which is directly related to the performance and quality of the final product. The secondary curing process described in this application achieves further optimization of resin wafers through precise temperature control and timing.

[0184] During the secondary curing process, the curing furnace is heated to a higher temperature (90℃~120℃) and maintained for a period of time (1h~5h), so that the molecular chains inside the resin wafer are more fully cross-linked, thereby improving its curing degree. This high degree of curing helps to enhance the heat resistance, hardness and dimensional stability of the resin wafer.

[0185] Fully cross-linked resins have higher glass transition temperatures, which means that resin wafers can maintain better shape stability and physical properties in high temperature environments, meeting application requirements under high temperature working conditions.

[0186] The constant temperature stage and cooling stage in the secondary curing process help to further release the residual stress inside the resin wafer, reduce deformation and cracking caused by stress concentration, and improve the flatness and surface quality of the product. In addition, the reduced internal stress helps to improve the optical properties of the resin wafer, such as increasing light transmittance and reducing birefringence, so that it has better performance in optical applications.

[0187] The surface of the resin wafer after secondary curing is smoother and flatter, without bubbles and defects, which improves the overall appearance quality of the product. The resin wafer after secondary curing has better processing performance, such as it is not easy to crack and break during cutting and drilling, which is conducive to the implementation of subsequent processes.

[0188] In the preparation method of the resin wafer provided in the present application, two fine curing steps are designed to ensure that the prepared resin wafer has excellent optical properties and quality. Among them, in the first curing stage, the mixed material II is transformed from liquid to solid through a precisely controlled temperature program. This process not only realizes the initial forming of the resin wafer, but also ensures that it matches the size of the preset mold and has a uniform thickness. The subsequent secondary curing, this stage aims to further cure the resin wafer, which not only greatly increases the glass transition temperature of the resin wafer, significantly enhances its heat resistance, but also releases the residual stress inside the resin wafer. This curing technology not only ensures that the resin wafer has excellent optical properties and mechanical strength, but also enables it to show good stability and durability when dealing with extreme environments.

[0189] The preparation method of the resin wafer of the present application is further described below through Examples 1 to 3.

[0190] Example 1

[0191] The method for preparing the resin wafer provided in this embodiment 1 is as follows:

[0192] (1) Weigh 700 parts of 2-methacryloylthiomethyl-1,4-dithiol, 240 parts of 3,4-toluenedithiol (two multifunctional thiol or thiol polymers are selected, and the sum of the two is 940 parts), 1.3 parts of di-tert-butyltin chloride (organic tin catalyst), 5 parts of 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole (anti-UV aging agent), and 0.7 parts of stearic acid (release agent), mix them evenly, and stir until the solid is completely dissolved to obtain a mixture I;

[0193] Weigh 53 parts of o-phthalimethylene diisocyanate (isocyanate); adjust the cooling circulating water temperature to 9°C, when the temperature of mixed material I drops to 13°C, add o-phthalimethylene diisocyanate to the mixing barrel containing mixed material I according to the proportion, stir rapidly and vacuum degas for 30 minutes, then stop stirring and degas for 15 minutes, cool and keep warm with circulating water at 9°C, filter with a 3-micron filter after the inert gas is depressurized, and obtain mixed material II, which is kept warm for standby use;

[0194] (2) injecting the heat-insulated mixed material II into the mold;

[0195] The selected mold is a metal or glass mold with high flatness and precise thickness control. The thickness error can be controlled within 5μm.

[0196] Among them, after the mold is set to the required gap, the mold is sealed with matching tape, leaving only one injection port for injecting mixed material II;

[0197] (3) First curing: After the mixed material II is injected into the mold, the injection port is sealed with tape, and the mold is placed flat in the curing oven for the first curing. The temperature program of the curing oven is set according to the preset first curing temperature curve, and preliminary heating and curing is performed; then the mold is opened after natural cooling to room temperature;

[0198] The temperature program of the first curing is as follows:

[0199] First, keep the temperature at 20℃ for 2.5h; then heat it up to 60℃ for about 9h; then heat it up to 90℃ for 3.5h; keep the temperature at 90℃ for 4h; then cool it down to 65℃ for 1h; then cool it down to room temperature and open the mold to remove the initially solidified resin wafer;

[0200] The initially cured resin wafer is taken out, trimmed and cleaned;

[0201] (4) Second curing: Place the cleaned resin wafer on one side of the mold, and then place it horizontally in the curing furnace again. Set the temperature program of the curing furnace according to the preset second curing temperature curve, and then perform secondary curing. The second curing process is as follows:

[0202] The curing furnace was initially heated to 80°C, and the resin wafer after preliminary curing was placed in it. The curing furnace was then heated to 95°C, and the heating time was 1 hour. The temperature was kept constant at 95°C for 3.5 hours. The temperature was then lowered to 65°C, and the cooling time was 1 hour.

[0203] After naturally cooling to room temperature in the curing furnace, the mold is taken out, the mold is opened and the resin wafer is taken out, and the secondary curing is completed.

[0204] Example 2

[0205] (1) Weigh 800 parts of 3,5-dimethyl-1,2,4-trithiocyclopentane, 145 parts of triphenylmethanethiol (two multifunctional mercapto or thiol polymers are selected, and the sum of the two is 945 parts), 1 part of dibutyltin dichloride (organic tin catalyst), 3 parts of 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole (anti-UV aging agent), and 0.5 parts of stearic acid (release agent), mix them evenly, and stir until the solid is completely dissolved to obtain a mixture I;

[0206] Weigh 50.5 parts of o-phthalimethylene diisocyanate (isocyanate); adjust the cooling circulating water temperature to 8°C, when the temperature of mixed material I drops to 12°C, add o-phthalimethylene diisocyanate to the mixing barrel containing mixed material I in proportion, stir rapidly and vacuum degas for 40 minutes, then stop stirring and degas for 20 minutes, cool and keep warm with circulating water at 10°C, filter with a 3-micron filter after the inert gas is depressurized, and obtain mixed material II, which is kept warm for standby use;

[0207] (2) injecting the heat-insulated mixed material II into the mold;

[0208] The selected mold is a metal or glass mold with high flatness and precise thickness control. The thickness error can be controlled within 5μm.

[0209] Among them, after the mold is set to the required gap, the mold is sealed with matching tape, leaving only one injection port for injecting mixed material II;

[0210] (3) First curing: After the mixed material II is injected into the mold, the injection port is sealed with tape, and the mold is placed flat in the curing oven for the first curing. The temperature program of the curing oven is set according to the preset first curing temperature curve, and preliminary heating and curing is performed; then the mold is opened after natural cooling to room temperature;

[0211] The temperature program of the first curing is as follows:

[0212] First, keep the temperature at 20℃ for 1.5h; then heat it up to 45℃ for about 10h; then heat it up to 90℃ for 3.5h; keep the temperature at 90℃ for 2h; cool it down to 50℃ for 1h; then cool it down to room temperature and open the mold to remove the initially solidified resin wafer;

[0213] The initially cured resin wafer is taken out, trimmed and cleaned;

[0214] (4) Second curing: Place the cleaned resin wafer on one side of the mold, and then place it horizontally in the curing furnace again. Set the temperature program of the curing furnace according to the preset second curing temperature curve, and then perform secondary curing. The second curing process is as follows:

[0215] The curing furnace was initially heated to 60°C, and the preliminarily cured resin wafer was placed in it. The curing furnace was then heated to 90°C, and the heating time was 1 hour. The temperature was kept constant at 90°C for 4 hours. The temperature was then lowered to 70°C, and the cooling time was 1 hour.

[0216] After naturally cooling to room temperature in the curing furnace, the mold is taken out, the mold is opened and the resin wafer is taken out, and the secondary curing is completed.

[0217] Example 3

[0218] (1) Weigh 650 parts of bis(2-methacryloethoxy) disulfide, 180 parts of 2-mercaptobenzothiazole (two multifunctional mercapto or thiol polymers are selected, and the sum of the two is 830 parts), 3 parts of di-tert-butyltin chloride (organic tin catalyst), 3 parts of 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole (anti-UV aging agent), and 0.3 parts of siloxane (release agent), mix them evenly, and stir until the solid is completely dissolved to obtain a mixture I;

[0219] Weigh 163.7 parts of o-phthalimethylene diisocyanate (isocyanate); adjust the cooling circulating water temperature to 10°C, when the temperature of mixed material I drops to 15°C, add o-phthalimethylene diisocyanate to the mixing barrel containing mixed material I in proportion, stir rapidly and vacuum degas for 45 minutes, then stop stirring and degas for 10 minutes, cool and keep warm with circulating water at 8°C, filter with a 3-micron filter after the inert gas is depressurized, and obtain mixed material II, which is kept warm for standby use;

[0220] (2) injecting the heat-insulated mixed material II into the mold;

[0221] The selected mold is a metal or glass mold with high flatness and precise thickness control. The thickness error can be controlled within 5μm.

[0222] Among them, after the mold is set to the required gap, the mold is sealed with matching tape, leaving only one injection port for injecting mixed material II;

[0223] (3) First curing: After the mixed material II is injected into the mold, the injection port is sealed with tape, and the mold is placed flat in the curing oven for the first curing. The temperature program of the curing oven is set according to the preset first curing temperature curve, and preliminary heating and curing is performed; then the mold is opened after natural cooling to room temperature;

[0224] The temperature program of the first curing is as follows:

[0225] First, keep the temperature at 15℃ for 2h; then heat it up to 50℃ for about 12h; then heat it up to 120℃ for 4h; keep the temperature at 90℃ for 3h; then cool it down to 70℃ for 1.5h; then cool it down to room temperature and open the mold to remove the initially solidified resin wafer;

[0226] The initially cured resin wafer is taken out, trimmed and cleaned;

[0227] (4) Second curing: Place the cleaned resin wafer on one side of the mold, and then place it horizontally in the curing furnace again. Set the temperature program of the curing furnace according to the preset second curing temperature curve, and then perform secondary curing. The second curing process is as follows:

[0228] The curing furnace was initially heated to 70°C, and the preliminarily cured resin wafer was placed in it. The curing furnace was then heated to 110°C, and the heating time was 1.5 hours. The temperature was kept constant at 110°C for 2 hours. The temperature was then lowered to 70°C, and the cooling time was 1.5 hours.

[0229] After naturally cooling to room temperature in the curing furnace, the mold is taken out, the mold is opened and the resin wafer is taken out, and the secondary curing is completed.

[0230] It should be noted that the catalyst in the above-mentioned Examples 1 to 3 is not limited to an organic tin catalyst, and can also be replaced by an amine catalyst as needed. The amine catalyst can be selected from at least one of triethylenediamine, bismorpholinyl diethyl ether and pentamethyldiethylenetriamine.

[0231] The above embodiments focus on the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0232] Although some specific embodiments of the present application have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are only for illustration, not for limiting the scope of the present application. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present application. The scope of the present application is defined by the appended claims.

Claims

1. A resin wafer, characterized in that: The following raw materials are included in parts by weight: 800-980 parts of multifunctional mercapto or thiol polymer, 10-200 parts of isocyanate, 0.05-10 parts of catalyst, 0.02-1 parts of release agent and 0.1-5 parts of anti-UV aging agent.

2. The resin wafer according to claim 1, characterized in that The multifunctional mercapto or thiol polymer includes at least one of 2,2'-[thiobis(methylene)]bisthiobutane, bis-2-methylacryloylethoxydisulfide, 3,5-dimethyl-1,2,4-trithiocyclopentane, 2-mercaptobenzothiazole, 1,5-pentanedithiol, pentaerythritol tetrakis(3-mercaptopropionic acid), 2-mercaptomethyl-1,4-dithiocyclohexane, 2-methacryloylthiomethyl-1,4-dithiocyclohexane, triphenylmethanethiol and 3,4-toluenedithiol.

3. The resin wafer according to claim 1, characterized in that: The isocyanate includes at least one of o-xylylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, toluene-2,4-diisocyanate, isophorone diisocyanate and 2,6-diisopropylphenyl isocyanate.

4. The resin wafer according to claim 1, characterized in that: The catalyst is an organic tin catalyst or an amine catalyst.

5. The resin wafer according to claim 4, characterized in that: The organotin catalyst includes at least one of dibutyltin dichloride, dihydroxybutyltin chloride, di-n-butyltin chloride, di-tert-butyltin chloride and dibutyltin diacetate; The amine catalyst includes at least one of triethylenediamine, bismorpholinyl diethyl ether and pentamethyldiethylenetriamine.

6. The resin wafer according to claim 1, characterized in that The release agent includes any one of stearic acid, silicone oil and siloxane release agents.

7. The resin wafer according to claim 1, characterized in that: The anti-UV aging agent includes any one of 2-(2'-hydroxy-3', 5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-hydroxy-4-n-octyloxybenzophenone, monobenzoic acid resorcinol ester and 2-(2'-hydroxy-3', 5'-di-tert-phenyl)-5-chlorobenzotriazole.

8. The resin wafer according to any one of claims 1 to 7, characterized in that: The refractive index of the resin wafer is ≥1.7, the light transmittance is ≥87.5%, and the glass transition temperature Tg is ≥103°C.

9. A method for preparing a resin wafer, characterized in that: The following steps are involved: Adding a release agent, a catalyst and an anti-UV aging agent to a multifunctional mercapto or thiol polymer to obtain a mixture I, cooling the mixture I and mixing it with an isocyanate to obtain a mixture II; Injecting the mixed material II into a mold; The mold is placed in a curing furnace, and the temperature program of the curing furnace is set according to a preset first curing temperature curve for preliminary curing. After cooling, the mold is opened to take out the preliminary cured wafer resin and clean it; The cleaned wafer resin is put into the mold again, and placed in a curing furnace to set the temperature program of the curing furnace according to a preset second curing degree curve for secondary curing. After cooling, the mold is opened to take out the resin wafer.

10. The preparation method according to claim 9, characterized in that: The release agent, catalyst and UV aging resistance agent are added to the multifunctional mercapto or thiol polymer to obtain a mixture I, and the mixture I is cooled and mixed with isocyanate to obtain a mixture II, comprising: Adding an anti-UV aging agent, a release agent and a catalyst to a multifunctional mercapto or thiol polymer, stirring until the solid is completely dissolved, to obtain a mixture I; The mixture I is cooled by cooling circulating water, the temperature of the cooling circulating water is 3°C to 8°C, when the temperature of the mixture I is reduced to 10°C to 15°C, isocyanate is added to the mixture I, stirred and vacuum degassed for 30min to 60min, and then the stirring and degassing are stopped for 10min to 30min; Cooling and heat preservation with circulating water at 6°C to 10°C, filtering with a 1μm to 5μm filter screen after depressurization with inert gas to obtain mixed material II, and keeping the mixed material II warm for later use; Among them, according to the mass parts: the multifunctional mercapto or thiol polymer is 800-980 parts, the isocyanate is 10-200 parts, the catalyst is 0.05-10 parts, the release agent is 0.02-1.0 parts and the anti-UV aging agent is 0.1-5 parts.

11. The preparation method according to claim 9, characterized in that: The step of placing the mold into a curing furnace, setting the temperature program of the curing furnace according to a preset first curing temperature curve for preliminary curing, and opening the mold after cooling to take out the preliminary cured wafer resin and clean it, comprises: The mold is placed flat in a curing oven, and the temperature program of the curing oven is set according to a preset first curing temperature curve to perform a first curing. The first curing process includes: Keep the temperature at 10℃~20℃ for 1h~3h; increase the temperature to 40℃~60℃, the heating time is 8h~15h; continue to increase the temperature to 70℃~120℃, the heating time is 2h~4h; keep the temperature at 70℃~120℃ for 1h~4h; then cool down to 50℃~70℃, the cooling time is 0.5h~2h; After the mold is naturally cooled to room temperature, the mold is opened to take out the initially solidified resin wafer; The wafer resin after preliminary curing is trimmed and cleaned.

12. The preparation method according to claim 11, characterized in that: The cleaned wafer resin is put into the mold again, and placed in a curing furnace to set the temperature program of the curing furnace according to a preset second curing degree curve for secondary curing, and after cooling, the mold is opened to take out the resin wafer, including: The curing furnace is heated to 60°C to 80°C, the cleaned wafer resin is placed on one side of the mold, the mold is placed horizontally in the curing furnace, the temperature program of the curing furnace is set according to the second curing temperature curve, and the second curing is performed. The process of the second curing is as follows: The curing furnace is heated to 90°C-120°C for 0.5h-1h; the temperature is kept constant at 90°C-120°C for 1h-5h; then the temperature is lowered to 60°C-70°C for 0.5h-1h; after the mold is naturally cooled to room temperature, the mold is opened and the resin wafer is taken out.