Migration-resistant modified ultraviolet light absorber and preparation method thereof
By modifying the double bonds of triazine UV absorbers, a migration-resistant modified UV absorber was prepared and crosslinked with the photovoltaic film matrix resin, solving the problem of easy migration of traditional UV absorbers and realizing long-lasting UV protection and high-efficiency power generation of photovoltaic modules.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CYBRID TECHNOLOGIES INC
- Filing Date
- 2025-12-31
- Publication Date
- 2026-04-10
AI Technical Summary
Traditional UV absorbers tend to migrate within photovoltaic films, leading to a decrease in UV protection effectiveness and impacting the lifespan and power generation efficiency of photovoltaic modules, especially in heterojunction cells.
By modifying the double bonds of triazine-based ultraviolet absorbers, carbon-carbon double bonds are introduced into the molecular structure to prepare migration-resistant modified ultraviolet absorbers. These absorbers then undergo a cross-linking reaction with the photovoltaic film matrix resin under a thermal initiation system to form a stable bond.
It effectively solves the migration problem of ultraviolet absorbers, maintains excellent ultraviolet light blocking performance, provides long-lasting and reliable protection, and extends the service life and power generation efficiency of photovoltaic modules.
Smart Images
Figure CN121824441A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of ultraviolet absorber technology, and particularly relates to a migration-resistant modified ultraviolet absorber and its preparation method. Background Technology
[0002] With the development of science and technology, polymer materials are increasingly widely used in various fields. However, these materials are susceptible to environmental factors such as ultraviolet radiation, heat, and oxygen during use, leading to problems such as aging, yellowing, and brittleness, which significantly degrade their performance and shorten their service life. To address this, researchers have developed light stabilizer-based anti-aging materials, among which ultraviolet absorbers are the most crucial anti-aging method.
[0003] With the rapid development of photovoltaic technology and the increasing prevalence of photovoltaic modules, photovoltaic encapsulant film, as a core component of photovoltaic modules, directly determines the lifespan and power generation efficiency of the modules. Existing photovoltaic encapsulant films mostly use ethylene-vinyl acetate copolymer (EVA) or polyolefin elastomer (POE) as substrates, which generally suffer from insufficient effective UV blocking capability. This makes it difficult to provide reliable protection for the core structures inside the module, such as the solar cells and the underlying backsheet. Consequently, these structures are prone to aging, cracking, and pulverization under UV irradiation, severely impacting the service life of photovoltaic modules.
[0004] Adding antioxidants and UV absorbers to photovoltaic (PV) films is a common method to improve their aging resistance. However, traditional UV absorbers have significant limitations. Traditional UV absorbers have poor compatibility with polymer matrices and tend to migrate and volatilize to the material surface during use. This not only significantly weakens the UV protection effect of the film but also affects its compatibility with the matrix material. Especially in special applications like PV films, the surface migration of UV absorbers directly leads to a decrease in the film's UV cutoff capability, resulting in a continuous decline in PV module power and further exacerbating the loss of module lifespan and power generation efficiency. More importantly, new PV cells such as heterojunction (HJT) cells are more sensitive to UV radiation, placing higher demands on the UV cutoff capability of the encapsulation film. Reliable UV protection is urgently needed to ensure cell safety and extend module lifespan.
[0005] In summary, developing a UV absorber with excellent migration resistance and applying it to photovoltaic encapsulant materials to meet the requirements of photovoltaic modules for efficient UV cutoff has become an important research direction in the current photovoltaic technology field. Summary of the Invention
[0006] To address the aforementioned technical problems, this invention provides a migration-resistant modified ultraviolet absorber and its preparation method. By modifying the double bonds of triazine-based ultraviolet absorbers, carbon-carbon double bonds are introduced into the molecular structure as active reaction sites, thus preparing a migration-resistant modified ultraviolet absorber. This migration-resistant modified ultraviolet absorber can be grafted onto the photovoltaic film matrix resin under high-temperature conditions in a thermally initiated system. This effectively solves the problem of easy migration of traditional triazine-based ultraviolet absorbers, significantly improving their stability in the film, while fully retaining their excellent ultraviolet light blocking performance, thereby providing durable and reliable protection for photovoltaic modules.
[0007] The first objective of this invention is to provide a method for preparing a migration-resistant modified ultraviolet absorber, comprising the following steps: under a protective atmosphere, a triazine ultraviolet absorber, a grafting agent and a stabilizer are reacted in a diluent under the action of a neutralizing agent or a catalyst to obtain the migration-resistant modified ultraviolet absorber; The triazine-based ultraviolet absorber is selected from the following structures: (UV400) (UV405).
[0008] In one embodiment of the present invention, the grafting agent is selected from one or more of acyl chloride compounds, isocyanate compounds, and acrylate compounds.
[0009] In one embodiment of the present invention, the acyl chloride compound is selected from acryloyl chloride and / or methacryloyl chloride; preferably, the acyl chloride compound is acryloyl chloride; And / or, the isocyanate compound is selected from ethyl isocyanate methacrylate and / or ethyl isocyanate acrylate; preferably, the isocyanate compound is ethyl isocyanate acrylate; And / or, the acrylate compound is selected from one or more of methyl acrylate, ethyl acrylate, methyl methacrylate and ethyl methacrylate; preferably, the acrylate compound is methyl acrylate.
[0010] In one embodiment of the present invention, the stabilizer is selected from one or more of p-hydroxyanisole, 2,6-di-tert-butyl-p-methylphenol and tert-butylcatechol to improve the stability of carbon-carbon double bonds.
[0011] Furthermore, the stabilizer is 2,6-di-tert-butyl-p-methylphenol.
[0012] In one embodiment of the present invention, the neutralizing agent is selected from triethylamine and / or N-methylmorpholine.
[0013] Furthermore, the neutralizing agent is triethylamine.
[0014] In one embodiment of the present invention, when the grafting agent is an acyl chloride compound, the reaction is carried out under the action of a neutralizing agent because the acyl chloride grafting method generates hydrochloric acid as a byproduct, which must be eliminated by a neutralizing agent.
[0015] In one embodiment of the present invention, the catalyst is selected from one or more of stannous octoate, dibutyltin dilaurate, di(dodecylmercapto)dibutyltin, dibutyltin oxide, bismuth isooctanoate, zinc isooctanoate, isopropyl titanate, and tetrabutyl titanate.
[0016] In one embodiment of the present invention, the grafting agent is selected from isocyanate compounds and / or acrylate compounds, and the reaction is carried out under the action of a catalyst.
[0017] In one embodiment of the present invention, the diluent is selected from ethyl acetate, methacryloxypropyltrimethoxysilane, or butanone.
[0018] In one embodiment of the present invention, when the grafting agent is an acyl chloride compound, the reaction temperature is 0 ℃-5 ℃, for example, it can be 0 ℃, 1 ℃, 2 ℃, 3 ℃, 4 ℃, 5 ℃, etc.; And / or, when the grafting agent is an isocyanate compound, the reaction temperature is 50 ℃-65 ℃, for example, it can be 50 ℃, 51 ℃, 52 ℃, 53 ℃, 54 ℃, 55 ℃, 56 ℃, 57 ℃, 58 ℃, 59 ℃, 60 ℃, 61 ℃, 62 ℃, 63 ℃, 64 ℃, 65 ℃, etc.; And / or, when the grafting agent is an acrylate compound, the reaction temperature is 80 ℃-90 ℃, for example, it can be 80 ℃, 81 ℃, 82 ℃, 83 ℃, 84 ℃, 85 ℃, 86 ℃, 87 ℃, 88 ℃, 89 ℃, 90 ℃, etc.
[0019] In one embodiment of the present invention, the molar ratio of the triazine ultraviolet absorber to the grafting agent is 1:(1-2).
[0020] A second objective of this invention is to provide a migration-resistant modified ultraviolet absorber prepared by the method described above.
[0021] The technical solution of the present invention has the following advantages compared with the prior art: The preparation method described in this invention introduces carbon-carbon double bonds into the molecular structure of triazine-based ultraviolet absorbers by utilizing the reaction sites of the branched chains to prepare migration-resistant modified ultraviolet absorbers. Subsequently, under the synergistic effect of peroxide initiators and small molecule co-crosslinking agents such as methacryloyloxytrimethoxysilane, methacryloyloxytriethoxysilane, triallyl isocyanurate, and trimethylolpropane triacrylate, this migration-resistant modified ultraviolet absorber can undergo a free radical-initiated crosslinking reaction in the resin system of the encapsulated film matrix. By abstracting hydrogen atoms from the resin molecules to form free radicals, it then tightly binds to the resin matrix as a whole. Thus, by modifying the ultraviolet absorber molecules by grafting carbon-carbon double bonds, it adapts to the co-crosslinking system of the encapsulated film, ultimately achieving the migration-resistant effect of the ultraviolet absorber. Attached Figure Description
[0022] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is a comparison of the ultraviolet absorption curves of the unmodified triazine ultraviolet absorber and the modified ultraviolet absorber in the wavelength range of 200nm-450nm in Test Example 1 of the present invention. Detailed Implementation
[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. It should be understood that the specific embodiments are only used to explain the present invention, but the embodiments are not intended to limit the present invention.
[0024] In this invention, unless otherwise stated, the terms “center,” “upper,” “lower,” “left,” “right,” “vertical,” “horizontal,” “inner,” and “outer,” etc., used to indicate orientation or positional relationships are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention; the terms “A,” “B,” and “C” are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0025] In this invention, unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.
[0026] In this invention, unless otherwise stated, the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0027] In this invention, unless otherwise specified, the experimental methods used in the embodiments of this invention are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.
[0028] In this invention, unless otherwise stated, UV400 and UV405 used in the embodiments of this invention need to be purified before use: they are placed in a rotary evaporator and the diluent is removed at 110 °C until the content of solid components reaches more than 99%.
[0029] In this invention, unless otherwise stated, the ethylene-vinyl acetate copolymer used in the embodiments of this invention was purchased from Sirbon Petrochemical, model V2825. Example 1
[0030] The migration-resistant modified ultraviolet absorber and its preparation method in this embodiment specifically include the following steps: Weigh 100 g of triazine-based ultraviolet absorber UV400, 150 g of diluent ethyl acetate, 15 g of neutralizing agent triethylamine, and 0.06 g of stabilizer 2,6-di-tert-butyl-p-methylphenol, and mix and stir until the system becomes transparent; then cool the system to about 3°C and keep it at a constant temperature, and slowly add 21 g of acryloyl chloride dropwise under a nitrogen atmosphere, while continuously monitoring the pH of the mixture. The reaction is terminated when the pH is ≤7.5; filter the mixture after the reaction, and place the filtrate at 70°C for rotary evaporation until the content of solid components reaches more than 99%, thus obtaining the migration-resistant modified ultraviolet absorber, denoted as UV400-A; The structural formula of UV400-A is as follows: . Example 2
[0031] The migration-resistant modified ultraviolet absorber and its preparation method in this embodiment specifically include the following steps: Weigh 100 g of triazine UV absorber UV405, 150 g of diluent ethyl acetate, 16.5 g of neutralizing agent triethylamine, and 0.06 g of stabilizer 2,6-di-tert-butyl-p-methylphenol, and mix and stir until the system becomes transparent; then cool the system to about 3 °C and keep it at a constant temperature. Under a nitrogen atmosphere, slowly add 23 g of acryloyl chloride, while continuously monitoring the pH of the mixture. Terminate the reaction when the pH is ≤7.5; filter the mixture after the reaction, and place the filtrate at 70 °C for rotary evaporation until the content of solid components reaches more than 99%, thus obtaining the migration-resistant modified UV absorber, denoted as UV405-A; The structural formula of UV405-A is as follows: . Example 3
[0032] The migration-resistant modified ultraviolet absorber and its preparation method in this embodiment specifically include the following steps: Weigh 100 g of triazine-based ultraviolet absorber UV400, 78 g of diluent methacryloyloxypropyltrimethoxysilane, 0.015 g of catalyst di(dodecylmercapto)dibutyltin, and 0.05 g of stabilizer 2,6-di-tert-butyl-p-methylphenol, and mix and stir until the system becomes transparent; then heat the system to about 58 °C and keep it at a constant temperature, and slowly add 22 g of isocyanate-based ethyl acrylate under a nitrogen atmosphere, while continuously monitoring NCO% < 0.5% to terminate the reaction, thus obtaining a migration-resistant modified ultraviolet absorber, denoted as UV400-B; The structural formula of UV400-B is as follows: . Example 4
[0033] The migration-resistant modified ultraviolet absorber and its preparation method in this embodiment specifically include the following steps: Weigh 105 g of triazine-based ultraviolet absorber UV405, 113 g of diluent methacryloyloxypropyltrimethoxysilane, 0.015 g of catalyst di(dodecylmercapto)dibutyltin, and 0.07 g of stabilizer 2,6-di-tert-butyl-p-methylphenol, and mix and stir until the system becomes transparent; then heat the system to about 58 °C and keep it at a constant temperature, and slowly add 40 g of isocyanate-based ethyl acrylate dropwise under a nitrogen atmosphere, while continuously monitoring NCO% < 0.5% to terminate the reaction, thus obtaining a migration-resistant modified ultraviolet absorber, denoted as UV405-B; The structural formula of UV405-B is as follows: . Example 5
[0034] The migration-resistant modified ultraviolet absorber and its preparation method in this embodiment specifically include the following steps: Weigh 100 g of triazine-based ultraviolet absorber UV400, 100 g of diluent methyl ethyl ketone (MEK), 40 g of methyl methacrylate (Methyl methacrylate), 0.015 g of catalyst tetrabutyl titanate (Tetrabutyl titanate), and 0.04 g of stabilizer 2,6-di-tert-butyl-p-methylphenol (2,6-di-tert-butyl-p-methylphenol), and mix them thoroughly. Then, heat the system to about 85 °C and keep it at that temperature. Under a nitrogen atmosphere, control the temperature at the top of the reaction tower to be >65 °C until no obvious liquid drips from the top of the tower. Cool the temperature down to 50 °C and collect the liquid. Place the resulting liquid at 70 °C for rotary evaporation until the content of solid components reaches more than 99%. This yields a migration-resistant modified ultraviolet absorber, denoted as UV400-C. The structural formula of UV400-C is as follows: . Test Example 1
[0035] Weigh 0.001 g each of UV400, UV400-A, UV400-B, UV400-C, UV405, UV405-A, and UV405-B into seven 1000 mL volumetric flasks. Add tetrahydrofuran as a solvent and sonicate for 10 min to completely dissolve the samples. Then, dilute to the mark with anhydrous ethanol and shake well to obtain standard test solutions with a concentration of 1 mg / 1000 mL. After each standard test solution has stood for 15 min, using tetrahydrofuran as a blank reference, perform scanning tests using a UV-Vis spectrophotometer in the wavelength range of 200 nm–450 nm. Set the scan rate to 100 nm / min and the bandwidth to 2 nm. Repeat the test three times for each sample, record the absorbance values at each wavelength, plot the UV absorption curves, and focus on analyzing the absorption performance in the 280 nm–380 nm band. The results are as follows: Figure 1 As shown. From Figure 1 It can be seen that the unmodified triazine ultraviolet absorbers UV400 and UV405 both exhibit typical absorption characteristics of hydroxytriazine compounds, with strong absorption peaks at wavelengths of 290 nm and 340 nm, and maintain high absorbance across the entire 280 nm-380 nm band, indicating that they possess excellent UV cutoff capabilities and can effectively absorb ultraviolet light in this band. Meanwhile, the UV absorption curves of samples UV400-A, UV400-B, UV400-C, UV405-A, and UV405-B modified with different grafting agents highly overlapped with the corresponding unmodified raw materials UV400 and UV405. The characteristic absorption peaks at 290 nm and 340 nm showed no significant shift, and the absorbance values in the 280 nm-380 nm band were not significantly different from those of the unmodified samples. This indicates that when the triazine UV absorbers were modified with acyl chloride, isocyanate, or acrylate grafting agents, only carbon-carbon double bonds were introduced into the molecular structure as active reaction sites, without destroying their original UV absorption core structure. This indicates that the modified UV absorber retains the high efficiency of the triazine parent compound in blocking UV light in the 280 nm-380 nm band. Furthermore, through the introduction of carbon-carbon double bonds, it can form a stable bond with the photovoltaic film matrix resin through a cross-linking reaction under the synergistic effect of the thermal initiation system and the cross-linking agent. This solves the problem of easy migration of traditional UV absorbers and provides long-lasting and reliable UV protection for photovoltaic modules. Test Example 2
[0036] First, a blank sample was prepared. 500 g of ethylene-vinyl acetate copolymer was mixed with 5 g of tert-butyl peroxide-2-ethylhexyl carbonate and 1 g of methacryloxypropyltrimethoxysilane. The mixture was extruded into a film at 80 °C and then thermally crosslinked at 145 °C for 15 min to form a film with a thickness of about 225 μm. Subsequently, test examples 1-7 were prepared by extruding 500 g of ethylene-vinyl acetate copolymer, 5 g of tert-butyl peroxide-2-ethylhexyl carbonate, 1 g of ultraviolet absorbers (UV400, UV405, UV400-A, UV400-B, UV400-C, UV405-A and UV405-B, respectively) and 1 g of methacryloxypropyltrimethoxysilane at 80 °C to form a film, and then thermally crosslinking it at 145 °C for 15 min to form a film with a thickness of approximately 225 μm. Finally, after measuring the initial transmittance of the blank sample and test examples 1-7 in the UV band 280 nm-380 nm, the blank sample and the adhesive film of each test example were bonded together for 14 days at 50 ℃ and 0.5 MPa. After 14 days, the bonded adhesive film was removed, and the transmittance of the blank sample (named blank sample 1-7) bonded with each test example in the UV band 280 nm-380 nm was measured. The results are shown in Table 1. Table 1
[0037] As shown in Table 1, the blank sample without added UV absorber had a transmittance as high as 87.87% in the 280 nm-380 nm wavelength range, indicating extremely poor UV cutoff capability. In contrast, test examples 1-7, due to the addition of UV absorbers, all showed a transmittance of approximately 5% in this wavelength range, with minimal differences in transmittance among the test examples. This indicates that the unmodified UV400, UV405, and the modified UV absorbers prepared in Examples 1-5 all possess excellent UV cutoff performance, and the modification treatment did not significantly affect the core UV absorption function. After the bonding experiment, the transmittance of blank sample 1 bonded to test example 1 (containing unmodified UV400) decreased to 10.33%, and the transmittance of blank sample 2 bonded to test example 2 (containing unmodified UV405) decreased to 9.56%. The transmittance of the unmodified UV400 and UV405 was significantly lower than that of the initial blank sample, indicating that the unmodified UV400 and UV405 migrated from the test film to the blank sample, giving the blank sample a certain UV cutoff capability. The transmittance of blank sample 3-7, which was bonded to test sample 3-7 (containing modified UV absorber), remained at around 87% in the 280 nm-380 nm band, which was basically consistent with the transmittance of the initial blank sample and did not show a significant decrease. This indicates that by introducing carbon-carbon double bonds into the molecular structure of triazine UV absorber, it can undergo a cross-linking reaction with the film matrix resin under the synergistic effect of thermal initiation system and cross-linking agent, effectively solving the problem of easy migration of traditional UV absorbers and achieving excellent migration resistance.
[0038] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. A method for preparing a migration-resistant modified ultraviolet absorber, characterized in that, Includes the following steps: Under a protective atmosphere, a triazine-based ultraviolet absorber, a grafting agent, and a stabilizer are reacted in a diluent under the action of a neutralizing agent or a catalyst to obtain the migration-resistant modified ultraviolet absorber. The triazine-based ultraviolet absorber is selected from the following structures: 、 。 2. The method for preparing the migration-resistant modified ultraviolet absorber according to claim 1, characterized in that, The grafting agent is selected from one or more of acyl chloride compounds, isocyanate compounds, and acrylate compounds.
3. The method for preparing the migration-resistant modified ultraviolet absorber according to claim 2, characterized in that, The acyl chloride compound is selected from acryloyl chloride and / or methacryloyl chloride; And / or, the isocyanate compound is selected from ethyl isocyanate methacrylate and / or ethyl isocyanate acrylate; And / or, the acrylate compound is selected from one or more of methyl acrylate, ethyl acrylate, methyl methacrylate and ethyl methacrylate.
4. The method for preparing the migration-resistant modified ultraviolet absorber according to claim 1, characterized in that, The stabilizer is selected from one or more of p-hydroxyanisole, 2,6-di-tert-butyl-p-methylphenol, and tert-butylcatechol.
5. The method for preparing the migration-resistant modified ultraviolet absorber according to claim 1, characterized in that, The neutralizing agent is selected from triethylamine and / or N-methylmorpholine.
6. The method for preparing the migration-resistant modified ultraviolet absorber according to claim 1, characterized in that, The catalyst is selected from one or more of stannous octoate, dibutyltin dilaurate, di(dodecylmercapto)dibutyltin, dibutyltin oxide, bismuth isooctanoate, zinc isooctanoate, isopropyl titanate, and tetrabutyl titanate.
7. The method for preparing the migration-resistant modified ultraviolet absorber according to claim 1, characterized in that, The diluent is selected from ethyl acetate, methacryloyloxypropyltrimethoxysilane, or butanone.
8. The method for preparing the migration-resistant modified ultraviolet absorber according to claim 2, characterized in that, When the grafting agent is an acyl chloride compound, the reaction temperature is 0 ℃-5 ℃; And / or, when the grafting agent is an isocyanate compound, the reaction temperature is 50 °C–65 °C; And / or, when the grafting agent is an acrylate compound, the reaction temperature is 80 ℃-90 ℃.
9. The method for preparing the migration-resistant modified ultraviolet absorber according to claim 1, characterized in that, The molar ratio of the triazine ultraviolet absorber to the grafting agent is 1:(1-2).
10. A migration-resistant modified ultraviolet absorber prepared by the method according to any one of claims 1-9.