A rare earth complex light stabilizer, its preparation method and use
By optimizing the ligand structure and doping ratio of rare earth complex light stabilizers [Ce(triRNTB)2]X3 and/or RE(BP)3, a bifunctional "light conversion-stabilization" composite system was constructed, which solved the compatibility and photodegradation problems of blue light converters, significantly extended the lifetime of blue organic fluorescent dye light conversion films, and achieved efficient photostability and light conversion efficiency compensation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GANJIANG INNOVATION ACAD CHINESE ACAD OF SCI
- Filing Date
- 2026-01-20
- Publication Date
- 2026-06-23
AI Technical Summary
Existing blue light conversion agents have problems such as poor compatibility, easy deliquescence or photodegradation, which leads to a decrease in the light transmittance of the conversion film and a shortened lifespan. Traditional light stabilizers have limited protective effects in complex environments and cannot meet the needs of long-term use.
By using rare earth complex light stabilizers [Ce(triRNTB)2]X3 and/or RE(BP)3, and by optimizing the ligand structure and doping ratio, a light stabilizer that can enhance the luminescence intensity without decaying after UV aging was prepared and used in blue organic fluorescent dye conversion films to construct a "conversion-stabilization" bifunctional composite system.
It significantly improves the photostability and lifespan of the blue light conversion film, extends the lifespan of the blue organic fluorescent dye conversion film by more than 60%, solves the photostability bottleneck, and achieves efficient light conversion efficiency compensation.
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Figure CN121537349B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of functional materials technology, and in particular to a rare earth complex light stabilizer, its preparation method, and its uses. Background Technology
[0002] Currently, commercially available blue light conversion agents mainly fall into two categories: rare-earth inorganic compounds and organic fluorescent dyes. In terms of material properties, while rare-earth inorganic compounds possess the advantage of high crystallinity, their hygroscopic nature significantly reduces interfacial compatibility with polymer matrices, leading to difficulties in micro-dispersion and resulting in deterioration of film optical uniformity and reduced transmittance. While organic fluorescent dyes (especially small-molecule organic fluorescent dyes) can achieve molecular-level dispersion, their conjugated chromophores are susceptible to photo-oxidative degradation induced by ultraviolet light, resulting in shortened material lifespan and higher manufacturing costs. To suppress this photochemical degradation, the industry's conventional solution is to combine ultraviolet absorbers with hindered amine light stabilizers, achieving light stabilization through energy quenching and free radical capture mechanisms.
[0003] It is noteworthy that rare-earth cerium complexes exhibit unique photophysical properties due to their distinctive electronic transition mechanism (4f→5d spin-allowed transition, unlike the 4f→4f forbidden transition of traditional lanthanides). Through ligand field modulation strategies, their emission wavelength can be precisely tuned to the blue-green light region, a property that has been successfully applied to high-efficiency electroluminescent devices (such as OLEDs). However, research on the application of rare-earth cerium complexes in the field of light conversion materials is still in its early stages. Previous studies have confirmed that although the initial luminescence intensity of blue light conversion films based on cerium complexes is weak, their photoluminescence intensity exhibits a non-decaying enhancement phenomenon after continuous ultraviolet irradiation. This anomalous photostable characteristic is fundamentally different from the mechanism of action of conventional light stabilizers.
[0004] Existing blue light conversion agents (such as rare earth inorganic compounds and organic fluorescent dyes) suffer from poor compatibility, hygroscopicity, or photodegradation, leading to decreased light transmittance and shortened lifespan of the conversion film. Traditional light stabilizers offer limited protection in complex environments, making it difficult to meet long-term usage requirements.
[0005] Therefore, how to develop a novel light stabilizer that combines high photostability and environmental adaptability, and its preparation method, has become an urgent problem to be solved. Summary of the Invention
[0006] To address the aforementioned technical problems, the present invention aims to provide a rare earth complex light stabilizer, its preparation method, and its applications. The rare earth complex light stabilizer of the present invention exhibits increased luminescence intensity after UV aging, significantly extending the lifespan of the light conversion film (more than 60% longer than traditional products). It is particularly suitable for extending the photostability and lifespan of blue organic fluorescent dye light conversion films.
[0007] To achieve this objective, the present invention adopts the following technical solution:
[0008] In a first aspect, the present invention provides a rare earth complex light stabilizer comprising [Ce(triRNTB)2]X3 and / or RE(BP)3, wherein the structural formula of [Ce(triRNTB)2]X3 is shown in formula (1) below, and the structural formula of RE(BP)3 is shown in formula (2) below:
[0009] Equation (1);
[0010] Equation (2);
[0011] In the formula, R is any one or a combination of at least two of H, Me (methyl), Et (ethyl), Pr (n-propyl) or Al (allyl);
[0012] X is -CH3COO - -CF3COO - -CF3SO3 - -acac - (Acetylacetone) or -EH - Any one or at least a combination of two of (2-ethylhexanoic acid);
[0013] In formula (2), Y is any one or a combination of at least two of hydroxyl, methoxy, n-octyloxy, dodecyloxy or propenoxy;
[0014] RE is one or a combination of at least two of the following: lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), or ytterbium (Yb).
[0015] The rare earth complex light stabilizer comprises 40-100 parts by weight of [Ce(triRNTB)2]X3 and 0-60 parts by weight of RE(BP)3. For example, the mass ratio of [Ce(triRNTB)2]X3 to RE(BP)3 can be 40:60, 45:55, 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 90:10, 95:5 or 100:0, but is not limited to the listed values. Other unlisted values within the range are also applicable, preferably 60-70:40-30.
[0016] The rare-earth complex light stabilizer provided by this invention exhibits excellent photostability, and its luminescence intensity does not decrease but rather increases after UV aging. This invention significantly improves the photostability and lifespan of the blue light conversion film by optimizing the ligand structure. After continuous UV irradiation, the PMMA (polymethyl methacrylate) light conversion film of this rare-earth cerium complex induces conformational optimization of the triRNTB ligand, increasing the absorbance of the complex at the 379 nm excitation wavelength, thereby enhancing the ligand's affinity for Ce. 3+ The energy transfer efficiency of the rare earth complex is improved, thereby increasing the luminescence intensity of the PMMA light-converting film after UV aging.
[0017] Currently, cerium complexes are mainly used in high-efficiency electroluminescent devices, and their application in photoluminescent materials is relatively limited. Based on the fact that cerium can emit blue light through ligand field modulation, it can be combined with organic blue light dyes to construct a "light conversion-stabilization" bifunctional composite system.
[0018] Compared to existing technologies, the rare earth complex light stabilizer provided by this invention can absorb some ultraviolet light and convert it into blue light. Its advantage lies in the fact that when added to the light conversion film of blue organic fluorescent dye, it can convert ultraviolet light into blue light and effectively improve the service life of the light conversion film of blue organic fluorescent dye.
[0019] This invention further controls the [Ce(triRNTB)2]X3 content to 40-100 parts by weight and the RE(BP)3 content to 0-60 parts by weight. By optimizing the ligand structure and doping ratio, this invention significantly improves the photostability and lifespan of the blue light conversion film. If too much [Ce(triRNTB)2]X3 is added, perforation is likely to occur on the surface of the conversion film, accelerating the attack of singlet oxygen on organic fluorescent dyes, resulting in limited improvement in photostability. If too much RE(BP)3 is added, the ultraviolet absorber will absorb ultraviolet light excessively, reducing the light conversion efficiency of organic fluorescent dyes, thereby reducing the luminescence intensity of the conversion film and affecting the light conversion performance of the conversion film.
[0020] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The technical objectives and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.
[0021] Preferably, the average particle size of [Ce(triRNTB)2]X3 and RE(BP)3 is less than or equal to 1 μm, for example, it can be 1 μm, 900 nm, 950 nm, 900 nm, 850 nm, 800 nm, 750 nm, 700 nm, 650 nm, 600 nm, 550 nm, 500 nm or 400 nm, but is not limited to the listed values, and other unlisted values within the range are also applicable.
[0022] In a second aspect, the present invention provides a method for preparing a rare earth complex light stabilizer as described in the first aspect, the method comprising the following steps:
[0023] (1) Mix cerium salt, encapsulate polybenzimidazole triRNTB and organic solvent. After the reaction is complete, the product is precipitated in an ether atmosphere to obtain [Ce(triRNTB)2]X3;
[0024] (2) Dissolve benzophenone-based ultraviolet absorbers in anhydrous ethanol, add a strong base, mix, and then add an aqueous solution of soluble rare earth salts to obtain RE(BP)3.
[0025] (3) Mix [Ce(triRNTB)2]X3 obtained in step (1) and RE(BP)3 obtained in step (2), grind them, and obtain rare earth complex light stabilizer.
[0026] The preparation method provided by the present invention involves reacting cerium salt and encapsulated polybenzimidazole triRNTB in a strongly polar organic solvent to generate [Ce(triRNTB)2]X3, and then precipitating [Ce(triRNTB)2]X3 solid in a weakly polar organic solvent atmosphere;
[0027] Since benzophenone-based UV absorbers are poorly soluble in anhydrous ethanol, the addition of a strong alkali can remove the protons from the phenolic hydroxyl groups of the benzophenone-based UV absorbers, thereby accelerating their dissolution and providing coordination sites for subsequent cerium ions. After deprotonation in ethanol, the benzophenone-based UV absorbers react with soluble rare earth salts to form RE(BP)3 complexes that are poorly soluble in aqueous ethanol solutions. Finally, the obtained products are mixed to obtain rare earth complex photostable agents. Furthermore, the strength of photostable enhancement can be altered by changing the mass ratio of [Ce(triRNTB)2]X3 to RE(BP)3.
[0028] The preparation method provided by this invention is stable, efficient, and produces products with controllable performance. The process is stable and cost-controllable, making it suitable for large-scale production.
[0029] Preferably, the cerium salt in step (1) includes any one or a combination of at least two of Ce(CH3COO)3, Ce(CF3COO)3, Ce(CF3SO3)3, Ce(acac)3 (cerium acetylacetone) or Ce(EH)3 (cerium 2-ethylhexanoate). Typical but non-limiting combinations include combinations of Ce(CH3COO)3 and Ce(CF3COO)3, combinations of Ce(CF3COO)3 and Ce(CF3SO3)3, combinations of Ce(CF3SO3)3 and Ce(acac)3, combinations of Ce(acac)3 and Ce(EH)3, combinations of Ce(CH3COO)3, Ce(CF3COO)3, and Ce(CF3SO3)3, combinations of Ce(CF3COO)3, Ce(CF3SO3)3 and Ce(acac)3, and preferably Ce(CH3COO)3.
[0030] Preferably, the encapsulated polybenzimidazole tripole ligand in step (1) includes any one or a combination of at least two of triNTB, triMeNTB, triEtNTB, triPrNTB, or triAlNTB. Typical but non-limiting combinations include combinations of triNTB and triMeNTB, combinations of triMeNTB and triEtNTB, combinations of triEtNTB and triPrNTB, combinations of triPrNTB and triAlNTB, combinations of triNTB, triMeNTB, and triEtNTB, and combinations of triEtNTB, triPrNTB, and triAlNTB. TriMeNTB is preferred.
[0031] Preferably, the organic solvent in step (1) includes any one or a combination of at least two of methanol, ethanol, acetonitrile, acetone, tetrahydrofuran or N,N-dimethylformamide. Typical but non-limiting combinations include combinations of methanol and ethanol, acetonitrile and acetone, tetrahydrofuran and N,N-dimethylformamide, acetone and tetrahydrofuran, methanol and N,N-dimethylformamide, acetonitrile, acetone and tetrahydrofuran, and methanol, ethanol and acetonitrile. Easier is ethanol and / or N,N-dimethylformamide.
[0032] Preferably, the molar ratio of the cerium salt and the encapsulated polybenzimidazole tripole ligand in step (1) is 1:2-2.5, for example, it can be 1:2.0, 1:2.1, 1:2.2, 1:2.3, 1:2.4 or 1:2.5, but is not limited to the listed values. Other unlisted values within the range are also applicable.
[0033] The present invention further controls the molar ratio of cerium salt and encapsulated polybenzimidazole tripole ligand to 1:2-2.5 to ensure stable synthesis of [Ce(triRNTB)2]X3, more preferably 1:2.
[0034] Preferably, the reaction time in step (1) is 3-5 days, for example, 3 days, 3.5 days, 4 days, 4.5 days, or 5 days, but not limited to the listed values. Other unlisted values within the range are also applicable. Considering the long reaction time of organic chemical synthesis, a longer reaction time can ensure a higher yield.
[0035] Preferably, after the reaction in step (1) and before obtaining [Ce(triRNTB)2]X3, the reaction product is washed with ether and dried.
[0036] Preferably, the washing is performed 3 to 5 times, and the drying is carried out in the air.
[0037] Preferably, the benzophenone-based ultraviolet absorber in step (2) includes any one or a combination of at least two of 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, or 4-propenoxy-2-hydroxybenzophenone (HABP). Typical but non-limiting combinations include combinations of 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-n-octyloxybenzophenone, combinations of 2-hydroxy-4-n-octyloxybenzophenone and 4-propenoxy-2-hydroxybenzophenone, combinations of 2-hydroxy-4-methoxybenzophenone and 4-propenoxy-2-hydroxybenzophenone, combinations of 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone and 4-propenoxy-2-hydroxybenzophenone, and preferably 4-propenoxy-2-hydroxybenzophenone.
[0038] Preferably, the strong base in step (2) includes sodium hydroxide and / or potassium hydroxide.
[0039] Preferably, the molar ratio of the strong alkali to the benzophenone-based ultraviolet absorber in step (2) is 1:1-1.2, for example, it can be 1:1, 1:1.1 or 1:1.2, but is not limited to the listed values. Other unlisted values within the range are also applicable, preferably 1:1.
[0040] Preferably, in step (2), the molar ratio of rare earth ions to benzophenone-based ultraviolet absorbers in the aqueous solution of the soluble rare earth salt is 1:3-3.3, for example, it can be 1:3, 1:3.1, 1:3.2 or 1:3.3, but is not limited to the listed values. Other unlisted values within the range are also applicable, preferably 1:3.
[0041] Preferably, after the reaction in step (2) and before obtaining RE(BP)3, solid-liquid separation and drying are also included.
[0042] Preferably, the mass ratio of [Ce(triRNTB)2]X3 to RE(BP)3 in step (3) is 40-100:0-60, for example, it can be 40:60, 45:55, 50:50, 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 90:10, 95:5 or 100:0, but is not limited to the listed values. Other unlisted values within the range are also applicable.
[0043] This invention further controls the mass ratio of [Ce(triRNTB)2]X3 to CeY3 to be 40-100:0-60. Within this ratio range, the photostability and lifespan of the blue light conversion film can be significantly improved. If too much [Ce(triRNTB)2]X3 is added, perforation is likely to occur on the surface of the conversion film, accelerating the attack of singlet oxygen on organic fluorescent dyes, resulting in limited improvement in photostability. If too much RE(BP)3 is added, the ultraviolet absorber will absorb ultraviolet light excessively, reducing the light conversion efficiency of organic fluorescent dyes, thereby reducing the luminescence intensity of the conversion film and affecting the light conversion performance of the conversion film.
[0044] Preferably, the grinding in step (3) is performed until the components are fully mixed.
[0045] As a preferred embodiment of the preparation method of the present invention, the preparation method includes the following steps:
[0046] (1) Mix cerium salt, encapsulate polybenzimidazole triRNTB and organic solvent, react in an ether atmosphere for 3-5 days, collect the reaction product, wash with ether 3-5 times, and dry in air for 2-7 days to obtain [Ce(triRNTB)2]X3;
[0047] (2) Dissolve benzophenone-based ultraviolet absorbers in anhydrous ethanol, add sodium hydroxide, mix, add an aqueous solution of soluble rare earth salts, filter to obtain precipitate, dry the precipitate to obtain RE(BP)3.
[0048] (3) Mix [Ce(triRNTB)2]X3 obtained in step (1) and RE(BP)3 obtained in step (2) at a mass ratio of 40-100:0-60, grind for 3-10 hours to mix evenly, and obtain rare earth complex light stabilizer.
[0049] Thirdly, the present invention provides a use of the rare earth complex light stabilizer as described in the first aspect, wherein the rare earth complex light stabilizer is used in light-converting materials.
[0050] This invention introduces rare-earth cerium complexes as novel functional additives into the light conversion system of organic fluorescent dyes. By constructing a "light conversion-stabilization" bifunctional composite system, the photostability bottleneck of small molecule dyes can be solved, and the photoluminescence enhancement effect of cerium complexes can be used to compensate for the light conversion efficiency. This strategy provides an innovative material design approach for developing long-lifetime, highly stable blue light conversion films, and has significant practical implications for promoting technological upgrades in fields such as agricultural light conversion films and optoelectronic displays.
[0051] The numerical range described in this invention includes not only the point values listed above, but also any point values within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values included in the range.
[0052] Compared with the prior art, the present invention has at least the following beneficial effects:
[0053] (1) The rare earth complex light stabilizer provided by the present invention has good photostability and its luminescence intensity does not decrease after ultraviolet light aging but is actually improved. The present invention significantly improves the photostability and service life of the blue light conversion film by optimizing the ligand structure.
[0054] (2) The preparation method provided by the present invention involves reacting cerium salt and encapsulated polybenzimidazole triRNTB in a strongly polar organic solvent to generate [Ce(triRNTB)2]X3, and then precipitating [Ce(triRNTB)2]X3 solid in a weakly polar organic solvent atmosphere. Since benzophenone-based UV absorbers are poorly soluble in anhydrous ethanol, the addition of a strong base can remove the protons on the phenolic hydroxyl groups of the benzophenone-based UV absorbers to accelerate the dissolution of the benzophenone-based UV absorbers and provide subsequent coordination sites with cerium ions. After the benzophenone-based UV absorbers are deprotonated in ethanol, they react with soluble rare earth salts to generate RE(BP)3 complexes that are poorly soluble in aqueous ethanol solutions. Finally, the products obtained separately are mixed to obtain rare earth complex light stabilizers. At the same time, the strength of the light stability enhancement ability can be changed by changing the mass ratio of [Ce(triRNTB)2]X3 and RE(BP)3. The preparation method provided by this invention is stable, efficient, and produces products with controllable performance. The process is stable and cost-controllable, making it suitable for large-scale production.
[0055] (3) This invention introduces rare earth cerium complexes as novel functional additives into the organic fluorescent dye conversion system. By constructing a "conversion-stabilization" bifunctional composite system, the photostability bottleneck of small molecule dyes can be solved, and the photoluminescence enhancement effect of cerium complexes can be used to compensate for the conversion efficiency. This strategy provides an innovative material design idea for developing long-lifetime, highly stable blue light conversion films, and has important practical significance for promoting the technological upgrading of agricultural light conversion films, optoelectronic displays, and other fields. Attached Figure Description
[0056] Figure 1 This is a comparison of the emission spectra of PMMA films prepared by co-doping with light stabilizers and blue organic fluorescent dyes obtained in Examples 1-7 and Comparative Examples 1-3 of this invention and the blank group PMMA films.
[0057] Figure 2 This is a comparison of the photostability of PMMA films prepared by co-doping with the photostability stabilizers and blue organic fluorescent dyes obtained in Examples 1-7 and Comparative Examples 1-3 of this invention, and the blank group of PMMA films.
[0058] Figure 3 These are comparison images of the surface morphology of PMMA films prepared by co-doping with light stabilizers and blue organic fluorescent dyes obtained in Examples 1-6 and Comparative Examples 1-2 of this invention, and the blank PMMA films before aging.
[0059] Figure 4 These are comparative images of the surface morphology of PMMA films prepared by co-doping with light stabilizers and blue organic fluorescent dyes obtained in Examples 1-6 and Comparative Examples 1-2 of this invention, and the blank PMMA films after aging. Detailed Implementation
[0060] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.
[0061] In this invention, the terms "first aspect," "second aspect," "third aspect," "fourth aspect," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first," "second," "third," "fourth," etc., serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on the quantity.
[0062] Unless otherwise specified, all reagents and consumables used in the following examples and comparative examples were purchased from conventional reagent manufacturers in the art; unless otherwise specified, the experimental methods and techniques used were conventional methods and techniques in the art.
[0063] Example 1
[0064] This embodiment provides a rare earth complex light stabilizer, which includes [Ce(triMeNTB)2](CH3COO)3.
[0065] The method for preparing rare earth complex light stabilizers provided in this embodiment includes the following steps:
[0066] Ce(CH3COO)3 and encapsulated polybenzimidazole triMeNTB were dissolved in ethanol and N,N-dimethylformamide respectively at a molar ratio of 1:2. The two were then mixed evenly and reacted in an ether atmosphere for several days. The crystalline product was collected, washed three times with ether, and dried in air for several days to obtain the [Ce(triMeNTB)2](CH3COO)3 rare earth complex light stabilizer.
[0067] Example 2
[0068] This embodiment provides a rare earth complex light stabilizer, which includes [Ce(triMeNTB)2](CH3COO)3 and Ce(HABP)3 in a mass ratio of 75:25.
[0069] The method for preparing rare earth complex light stabilizers provided in this embodiment includes the following steps:
[0070] (1) Ce(CH3COO)3 and encapsulated polybenzimidazole tri-legged ligand triMeNTB were dissolved in ethanol and N,N-dimethylformamide respectively at a molar ratio of 1:2. The two were then mixed evenly and reacted in an ether atmosphere for several days. The crystalline product was collected, washed three times with ether, and then dried in air for several days to obtain [Ce(triMeNTB)2](CH3COO)3.
[0071] (2) Dissolve the UV absorber 4-propenoxy-2-hydroxybenzophenone (HABP) in anhydrous ethanol, add sodium hydroxide, mix, add an aqueous solution of CeCl3, and after the reaction is complete, filter to obtain a precipitate. Dry the precipitate to obtain Ce(HABP)3.
[0072] (3) Mix [Ce(triMeNTB)2](CH3COO)3 and Ce(HABP)3 at a mass ratio of 75:25 and grind them thoroughly to obtain rare earth complex light stabilizer.
[0073] Example 3
[0074] This embodiment provides a rare earth complex light stabilizer, which includes [Ce(triMeNTB)2](CH3COO)3 and Ce(HABP)3 in a mass ratio of 50:50.
[0075] The method for preparing rare earth complex light stabilizers provided in this embodiment includes the following steps:
[0076] (1) Ce(CH3COO)3 and encapsulated polybenzimidazole tri-legged ligand triMeNTB were dissolved in ethanol and N,N-dimethylformamide respectively at a molar ratio of 1:2. The two were then mixed evenly and reacted in an ether atmosphere for several days. The crystalline product was collected, washed three times with ether, and then dried in air for several days to obtain [Ce(triMeNTB)2](CH3COO)3.
[0077] (2) Dissolve the UV absorber 4-propenoxy-2-hydroxybenzophenone (HABP) in anhydrous ethanol, add sodium hydroxide, mix, add an aqueous solution of CeCl3, and after the reaction is complete, filter to obtain a precipitate. Dry the precipitate to obtain Ce(HABP)3.
[0078] (3) Mix [Ce(triMeNTB)2](CH3COO)3 and Ce(HABP)3 at a mass ratio of 50:50 and grind them thoroughly to obtain rare earth complex light stabilizer.
[0079] Example 4
[0080] This embodiment provides a rare earth complex light stabilizer, which includes [Ce(triNTB)2](CH3COO)3 and Ce(HABP)3 in a mass ratio of 75:25.
[0081] The only difference from Example 1 is that, when preparing this rare earth complex light stabilizer, the encapsulated polybenzimidazole tripole ligand in step (1) is replaced by an equimolar amount of triNTB, while the other preparation steps remain unchanged.
[0082] Example 5
[0083] This embodiment provides a rare earth complex light stabilizer, which includes [Ce(triMeNTB)2](CF3COO)3 and Ce(HABP)3 in a mass ratio of 75:25. The only difference from Example 1 is that when preparing this rare earth complex light stabilizer, the cerium salt in step (1) is replaced by Ce(CH3COO)3 with an equimolar amount of Ce(CF3COO)3, and the other preparation steps remain unchanged.
[0084] Example 6
[0085] This embodiment provides a rare earth complex light stabilizer, which includes [Ce(triMeNTB)2](CH3COO)3 and La(HABP)3 in a mass ratio of 75:25.
[0086] The only difference from Example 2 is that when preparing this rare earth complex light stabilizer, the soluble rare earth salt in step (2) is replaced by an equal amount of LaCl3 instead of CeCl3, while the other preparation steps remain unchanged.
[0087] Example 7
[0088] This embodiment provides a rare earth complex light stabilizer, which includes [Ce(triMeNTB)2](CH3COO)3 and Ce(BP-3)3 in a mass ratio of 75:25. The only difference from Example 2 is that, in preparing this rare earth complex light stabilizer, the ultraviolet absorber in step (2) is replaced by an equal amount of 2-hydroxy-4-methoxybenzophenone (BP-3) instead of 4-propenoxy-2-hydroxybenzophenone (HABP), while the other preparation steps remain unchanged.
[0089] Comparative Example 1
[0090] This comparative example provides a light stabilizer that differs from Example 1 only in that it contains the same mass of encapsulated polybenzimidazole tripole ligand triMeNTB.
[0091] Comparative Example 2
[0092] This comparative example provides a light stabilizer, wherein the rare earth complex light stabilizer comprises encapsulated polybenzimidazole tripole ligand triMeNTB and ultraviolet absorber 4-propenoxy-2-hydroxybenzophenone (HABP) in a mass ratio of 75:25; the only difference from Example 2 is that, in the preparation of this rare earth complex light stabilizer, Ce(CH3COO)3 was not added in step (1) and an aqueous solution of CeCl3 was not added in step (2), while the other preparation steps remain unchanged.
[0093] Comparative Example 3
[0094] This comparative example provides a rare earth complex light stabilizer, which differs from Example 1 only in that, when preparing this rare earth complex light stabilizer, the mass ratio of [Ce(triMeNTB)2](CH3COO)3 and Ce(HABP)3 in step (3) is 25:75.
[0095] test:
[0096] The rare earth complex light stabilizers prepared in the examples and comparative examples were added to PMMA materials in a doping mass ratio of 1:1 between the rare earth complex light stabilizer and the blue organic fluorescent dye, with a total doping mass concentration of 0.4%, respectively, to form PMMA films.
[0097] Test method: The light stability was tested according to GB / T16422.3—2022 / ISO4892-3:2016 (aging conditions: lamp type: UVB 340; illumination: 8h, (50±3℃) BPT, 0.76W / (m²)). 2 •nm)@340nm; Spray (no light): 0.25; Condensation: 0.373h, (50±3℃)BPT), the luminescence intensity after different aging times was tested, and the normalized test results are shown in Table 1 below.
[0098] The "blank group" refers to PMMA films with a doping concentration of 0.2% for blue organic fluorescent dye.
[0099] Figure 1 This is a comparison of the emission spectra of PMMA films prepared by co-doping with the light stabilizers and blue organic fluorescent dyes obtained in Examples 1-7 and Comparative Examples 1-3 of this invention and the blank PMMA films. As can be seen from the figure, the rare earth complex light stabilizer reduces the luminescence intensity of the PMMA film with blue organic fluorescent dye. When the mass fraction of RE(BP)3 in the rare earth complex light stabilizer exceeds 60%, the luminescence intensity of the prepared PMMA film is significantly reduced, by more than 40%, which seriously affects the luminescence performance of the PMMA film with blue organic fluorescent dye. Therefore, the mass fraction of RE(BP)3 in the rare earth complex light stabilizer should be strictly limited.
[0100] Figure 2 This is a comparison of the photostability of PMMA films prepared by co-doping with the light stabilizers obtained in Examples 1-7 and Comparative Examples 1-3 of this invention and the blank PMMA films. The figures show that the rare-earth complex light stabilizer can significantly improve the weather resistance of the PMMA films with blue organic fluorescent dyes. Figure 1 The luminescence intensity of this rare earth complex light stabilizer can be increased by more than 60% in improving the service life of PMMA films with blue organic fluorescent dyes.
[0101] Figure 3 This is a comparison of the surface morphology of PMMA films prepared by co-doping with light stabilizers and blue organic fluorescent dyes in Examples 1-6 and Comparative Examples 1-2 of this invention and the blank PMMA films before aging. As can be seen from the figures, the rare earth complex light stabilizer can slightly improve the surface morphology of the PMMA films prepared by co-doping with blue organic fluorescent dyes before aging, making the surface more regular and smooth.
[0102] Figure 4These are comparison images of the surface morphology of PMMA films prepared by co-doping with light stabilizers and blue organic fluorescent dyes in Examples 1-6 and Comparative Examples 1-2 of this invention, and the blank PMMA films after aging. As can be seen from the images, when only [Ce(triRNTB)2]X3 is present in the rare earth complex light stabilizer, perforations are easily formed on the surface of the PMMA film with blue organic fluorescent dye after aging. The addition of RE(BP)3 can effectively reduce or even prevent the occurrence of perforations.
[0103] Table 1
[0104]
[0105] The test results show that:
[0106] (1) As can be seen from the comparison of Examples 1-7, Comparative Examples 1-2 and the blank group, this invention introduces rare earth cerium complexes as novel functional additives into the organic fluorescent dye conversion system. By constructing a "conversion-stabilization" bifunctional composite system, the photostability bottleneck of small molecule dyes can be solved, and the photoluminescence enhancement effect of cerium complexes can be used to compensate for the conversion efficiency. This strategy provides an innovative material design idea for developing long-lifetime, highly stable blue light conversion films, and has important practical significance for promoting the technological upgrading of light conversion materials.
[0107] (2) By comparing Examples 1-3 and Comparative Example 3, it can be seen that by further controlling the mass ratio of [Ce(triRNTB)2]X3 to RE(BP)3 to 40-100:0-60, the present invention can significantly improve the photostability and service life of the blue light conversion film. If the amount of [Ce(triRNTB)2]X3 added is too much, the surface of the light conversion film is prone to perforation, which accelerates the attack of singlet oxygen on organic fluorescent dyes, resulting in limited improvement in photostability. If the amount of RE(BP)3 added is too much, the ultraviolet absorber will absorb ultraviolet light excessively, reducing the light conversion efficiency of organic fluorescent dyes, thereby reducing the luminescence intensity of the light conversion film and affecting the light conversion performance of the light conversion film.
[0108] (3) As can be seen from Example 1 and Comparative Example 1, Example 2 and Comparative Example 2, the present invention can prepare rare earth complex light stabilizers that significantly improve the service life of PMMA films of blue organic fluorescent dyes by complexing different ligands with rare earth ions. However, when rare earth ions are lacking, they cannot significantly improve the service life of PMMA films of blue organic fluorescent dyes.
[0109] In summary, this invention introduces rare-earth cerium complexes as novel functional additives into the light conversion system of organic fluorescent dyes. By constructing a "light conversion-stabilization" bifunctional composite system, the photostability bottleneck of small molecule dyes can be solved, and the photoluminescence enhancement effect of cerium complexes can be used to compensate for the light conversion efficiency. This strategy provides an innovative material design approach for developing long-lifetime, highly stable blue light conversion films, and has significant practical implications for promoting the technological upgrading of light conversion materials.
[0110] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.
Claims
1. A rare earth complex light stabilizer, characterized in that, The rare earth complex light stabilizer includes [Ce(triRNTB)2]X3 and RE(BP)3, wherein the structural formula of [Ce(triRNTB)2]X3 is shown in formula (1) below, and the structural formula of RE(BP)3 is shown in formula (2) below: Equation (1); Equation (2); In formula (1), R is any one or a combination of at least two of H, methyl, or ethyl; X is -CH3COO - -CF3COO - or -CF3SO3 - Any one or at least two of them; In formula (2), Y is any one or a combination of at least two of methoxy, n-octyloxy or propenoxy; RE is one or a combination of at least two of lanthanum or cerium; The rare earth complex light stabilizer comprises 50-75 parts by weight of [Ce(triRNTB)2]X3 and 25-50 parts by weight of RE(BP)3.
2. The rare earth complex light stabilizer according to claim 1, characterized in that, The average particle size of both [Ce(triRNTB)2]X3 and RE(BP)3 is less than or equal to 1 μm.
3. A method for preparing a rare earth complex light stabilizer as described in claim 1 or 2, characterized in that, The preparation method includes the following steps: (1) Mix cerium salt, encapsulate polybenzimidazole triRNTB and organic solvent. After the reaction is complete, the product is precipitated in an ether atmosphere to obtain [Ce(triRNTB)2]X3; (2) Dissolve benzophenone-based ultraviolet absorbers in anhydrous ethanol, add a strong base, mix, and then add an aqueous solution of soluble rare earth salts to obtain RE(BP)3. (3) Mix [Ce(triRNTB)2]X3 obtained in step (1) and RE(BP)3 obtained in step (2), grind them, and obtain rare earth complex light stabilizer; The cerium salt in step (1) includes any one or a combination of at least two of Ce(CH3COO)3, Ce(CF3COO)3 or Ce(CF3SO3)3; The encapsulated polybenzimidazole triRNTB in step (1) includes any one or a combination of at least two of triNTB, triMeNTB, or triEtNTB; In step (3), the mass ratio of [Ce(triRNTB)2]X3 to RE(BP)3 is 50-75:25-50.
4. The preparation method according to claim 3, characterized in that, The organic solvent in step (1) includes any one or a combination of at least two of methanol, ethanol, acetonitrile, acetone, tetrahydrofuran or N,N-dimethylformamide.
5. The preparation method according to claim 3, characterized in that, The molar ratio of the cerium salt and the encapsulated polybenzimidazole tripole ligand in step (1) is 1:2-2.
5.
6. The preparation method according to claim 3, characterized in that, The preparation method includes the following steps: (1) Mix cerium salt, encapsulated polybenzimidazole triRNTB and organic solvent, react in an ether atmosphere for 3-5 days, collect the reaction product, wash with ether 3-5 times, and dry in air for 2-7 days to obtain [Ce(triRNTB)2]X3; The cerium salt in step (1) includes any one or a combination of at least two of Ce(CH3COO)3, Ce(CF3COO)3 or Ce(CF3SO3)3; The encapsulated polybenzimidazole triRNTB in step (1) includes any one or a combination of at least two of triNTB, triMeNTB, or triEtNTB; (2) Dissolve benzophenone-based ultraviolet absorbers in anhydrous ethanol, add sodium hydroxide, mix, add an aqueous solution of soluble rare earth salts, filter to obtain precipitate, dry the precipitate to obtain RE(BP)3. (3) Mix [Ce(triRNTB)2]X3 obtained in step (1) and RE(BP)3 obtained in step (2) at a mass ratio of 50-75:25-50, grind for 3-10 hours to obtain rare earth complex light stabilizer.
7. The use of a rare earth complex light stabilizer as described in claim 1 or 2, characterized in that, The rare earth complex light stabilizer is used in light-converting materials.