High-weather-resistance dye as well as preparation method and application thereof
By introducing a rigid conjugated chromophore core and a piperidineamine derivative of ethoxypyridinemethyl into the dye, a high weather-resistant dye was synthesized, solving the problem of easy fading and discoloration of dyes under harsh environments. This improved the lightfastness, weather resistance, and migration resistance, making it suitable for high-end fields such as engineering plastics, automotive coatings, and synthetic fibers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHANGHAI HUZHENG IND CO LTD
- Filing Date
- 2026-01-27
- Publication Date
- 2026-05-19
AI Technical Summary
Existing dyes are prone to photochemical degradation under long-term ultraviolet radiation and humid and hot environments, resulting in color fading and color shift. Furthermore, they are not firmly bound to the matrix and are easy to migrate, making it difficult to simultaneously improve lightfastness, heat resistance, and migration resistance.
A rigid conjugated chromophore core was constructed by condensing 5-bromo-4-fluoroindorubicin anhydride with 2,4-dichloro-7-methylquinoline, and a piperidineamine derivative containing ethoxypyridine methyl was introduced. A high-weather-resistant dye was synthesized through a two-step condensation reaction, forming a stable molecular structure.
It significantly improves the lightfastness, weather resistance, and migration resistance of dyes, resulting in bright and pure colors. It is suitable for high-end applications of high-weather-resistant coloring and solves the problem of easy fading and discoloration of existing dyes in harsh environments.
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Figure CN122059931A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of functional dye technology, and in particular to a high weather-resistant dye, its preparation method, and its application. Background Technology
[0002] High-end industrial applications such as automotive coatings, outdoor building materials, and engineering plastics place extremely stringent requirements on the weather resistance of dyes. Traditional dyes, especially azo and anthraquinone dyes, are widely used in general textile dyeing, but the chromophores in their molecular structure are prone to photochemical degradation under harsh environments such as long-term ultraviolet radiation and humid heat, leading to color fading, color shift, and even molecular chain breakage, making them unable to meet the requirements for long-term outdoor use.
[0003] Currently, the main technical means to improve the weather resistance of dyes include: first, adding ultraviolet absorbers and light stabilizers during dye post-treatment. While this method is simple, it suffers from problems such as easy migration of auxiliaries, poor durability, and potential impact on material transparency; second, structural modification of dye molecules, such as introducing electron-withdrawing groups like halogen atoms and cyano groups to improve molecular stability, or increasing molecular weight to reduce migration. However, these methods often only improve a single aspect of performance and cannot simultaneously improve lightfastness, heat resistance, and migration resistance. It is particularly noteworthy that there is a lack of dye structure designs capable of forming stable interactions with the material matrix. Most dyes are only physically dispersed in the matrix, and during long-term use, they are prone to migration and precipitation due to weak interfacial forces. How to design a highly weather-resistant dye at the molecular level that can maintain vibrant color, form a strong bond with the matrix, and possess multiple protective mechanisms has become a pressing technical challenge in this field. Summary of the Invention
[0004] To address the shortcomings of poor weather resistance in dyes, this application provides a highly weather-resistant dye, its preparation method, and its application. Through innovative molecular structure design and selection of specific raw material combinations, a novel yellow dye with both a rigid conjugated skeleton and metal coordination ability is developed, effectively solving the aforementioned technical bottlenecks.
[0005] In the first aspect, this application provides a high weather-resistant dye, which adopts the following technical solution: A highly weather-resistant dye has the following structural formula: .
[0006] Optionally, the high weather-resistant dye is prepared by the following reaction: , .
[0007] By adopting the above technical solution, a single compound yellow dye was synthesized through a two-step condensation reaction using 5-bromo-4-fluoroindorubicin anhydride, 2,4-dichloro-7-methylquinoline and 1-[(6-ethoxy-3-pyridyl)methyl]-4-piperidinamine as raw materials. First, a rigid conjugated chromophore core is constructed by condensing 5-bromo-4-fluoroindorubicin anhydride with 2,4-dichloro-7-methylquinoline. Then, a piperidineamine derivative containing ethoxypyridine methyl is introduced as a steric hindrance unit to provide stereoprotection. This significantly improves the lightfastness, weather resistance, and migration resistance of the dye. The resulting dye has bright and pure color and excellent durability, thus improving the defect of poor weather resistance of dyes.
[0008] Secondly, this application provides a method for preparing a highly weather-resistant dye, employing the following technical solution: A method for preparing a highly weather-resistant dye includes the following steps: S1. 5-Bromo-4-fluoroindorubicin anhydride, 2,4-dichloro-7-methylquinoline, alkaline substances and organic solvents are added to a reaction vessel and stirred. After the reaction is completed, the reaction solution is poured into ethanol, extracted with organic solvent, rotary evaporated and dried to obtain dye intermediate A. S2. Dye intermediate A is reacted with 1-[(6-ethoxy-3-pyridyl)methyl]-4-piperidinamine, organic solvent and catalyst under heating conditions. After the reaction is completed, the reaction solution is poured into water for separation. The obtained solid is filtered, recrystallized and dried to obtain a high weather-resistant dye.
[0009] Optionally, in step S1, the molar ratio of 5-bromo-4-fluoroindosan anhydride to 2,4-dichloro-7-methylquinoline is (1-1.2):1.
[0010] Optionally, in step S1, the alkaline substance is one or more of NaH, NaOH, and KOH.
[0011] Optionally, in step S1, the organic solvent is one or more of dimethyl sulfoxide, DMF, N-methylpyrrolidone, and chlorobenzene.
[0012] Optionally, in step S1, the heating temperature is 150-180℃ and the reaction time is 2-3 hours.
[0013] Optionally, in step S2, the molar ratio of dye intermediate A to 1-[(6-ethoxy-3-pyridyl)methyl]-4-piperidinamine is 1:(4-4.5).
[0014] Optionally, in step S2, the catalyst is one or more of potassium carbonate and cesium carbonate.
[0015] Optionally, in step S2, the heating temperature is 100-120℃ and the reaction time is 6-8 hours.
[0016] Thirdly, this application provides an application of a high weather-resistant dye, employing the following technical solution: An application of a high weather-resistant dye involves melting, granulating, and molding the high weather-resistant dye with a plastic resin to obtain colored plastic products.
[0017] Specifically, the molding process includes blown film and cast film stretching, and the plastic resin includes polyethylene terephthalate, polyethylene, and polypropylene.
[0018] By adopting the above technical solution, the dye has bright and pure color and high durability. It is suitable for high weather-resistant coloring in high-end fields such as engineering plastics, automotive coatings and synthetic fibers, and solves the technical problem of existing dyes fading and changing color easily in harsh environments.
[0019] In summary, this application includes at least one of the following beneficial technical effects: 1. First, a rigid conjugated chromophore core is constructed by condensing 5-bromo-4-fluoroindosan anhydride with 2,4-dichloro-7-methylquinoline. Then, a piperidineamine derivative containing ethoxypyridine methyl is introduced as a steric hindrance unit to provide stereoprotection. This significantly improves the lightfastness, weather resistance, and migration resistance of the dye. The resulting dye has bright and pure color and excellent durability, thus improving the defect of poor weather resistance of the dye. 2. This dye has bright and pure color and high durability. It is suitable for high weather-resistant coloring in high-end fields such as engineering plastics, automotive coatings and synthetic fibers, and solves the technical problem of existing dyes fading and changing color easily in harsh environments. Attached Figure Description
[0020] Figure 1 This is the nuclear magnetic resonance spectrum of a highly weather-resistant dye in Example 1.
[0021] Figure 2 The image shows the nuclear magnetic resonance spectrum of an analog dye from Comparative Example 2.
[0022] Figure 3 The images show a sample of a high weather-resistant dye, a sample of yellow masterbatch, and a sample of yellow PET film from Example 1.
[0023] Figure 4 The image shows a comparison of the fading of the yellow PET film in Application Example 1 and Comparative Example 1 after 500 hours of QUV accelerated aging test.
[0024] Figure 5 Thermogravimetric analysis (TGA) diagram of the high weather-resistant dye prepared in Example 1. Detailed Implementation
[0025] Example
[0026] This application discloses a highly weather-resistant dye.
[0027] Example 1
[0028] A highly weather-resistant dye is prepared by the following steps: S1. Under nitrogen protection, 262 g of 5-bromo-4-fluoroindosanhydride, 232 g of 2,4-dichloro-7-methylquinoline, 48 g of sodium hydride, and 2 L of N-methylpyrrolidone were added to a 5 L reactor. The mixture was heated to 160 °C in an oil bath and stirred for 2.5 hours. After the reaction was completed, the mixture was cooled to 25 °C, and the reaction solution was poured into 500 mL of ice-cold ethanol, resulting in the precipitation of a solid. The solid was extracted twice with 2 L of dichloromethane, and the organic phases were combined and the solvent was removed by rotary evaporation. The crude product was dried under vacuum at 60 °C for 6 hours to obtain dye intermediate A, with a yield of 93.0%.
[0029] S2. To another reaction vessel, add 442 g of dye intermediate A, 987 g of 1-[(6-ethoxy-3-pyridyl)methyl]-4-piperidinamine, 138 g of potassium carbonate, and 2.5 L of N,N-dimethylformamide. Heat the mixture to 110 °C and stir for 7 hours. After the reaction is complete, cool to 25 °C and pour the reaction solution into 1000 mL of ice water, precipitating a yellow solid. Filter and wash the filter cake with water until neutral. Purify the obtained solid by recrystallization with ethanol, and finally dry under vacuum at 80 °C for 8 hours to obtain a high weather-resistant dye with a yield of 88.5%.
[0030] The above preparation method involves the following reaction formula: , .
[0031] Example 2
[0032] The difference between Example 2 and Example 1 is that in step S1, the alkaline substance is replaced with 80g of sodium hydroxide, the organic solvent is replaced with 2L of DMF, the heating temperature is adjusted to 150℃, and the reaction time is adjusted to 3 hours, yielding dye intermediate A with a yield of 91.8%. In step S2, the organic solvent was replaced with 250 mL of chlorobenzene, the catalyst was replaced with 32.5 g of cesium carbonate, the heating temperature was adjusted to 100 °C, and the reaction time was adjusted to 8 hours. The yield of a high weather-resistant dye was 87.2%.
[0033] Example 3
[0034] The difference between Example 3 and Example 1 is that in step S1, the amount of 5-bromo-4-fluoroindocyanine anhydride was adjusted to 288 g, and the molar ratio of 5-bromo-4-fluoroindocyanine anhydride to 2,4-dichloro-7-methylquinoline was 1.1:1. The organic solvent was replaced with 2 L of dimethyl sulfoxide to obtain dye intermediate A with a yield of 94.5%.
[0035] In step S2, the amount of 1-[(6-ethoxy-3-pyridyl)methyl]-4-piperidinamine was adjusted to 1058 g, the molar ratio of 1-[(6-ethoxy-3-pyridyl)methyl]-4-piperidinamine to dye intermediate A was 4.5:1, the heating temperature was adjusted to 120 °C, and the reaction time was adjusted to 6 hours. The yield of a high-weather-resistant dye was 90.1%.
[0036] Example 4
[0037] The difference between Example 4 and Example 1 is that in step S1, the alkaline substance is replaced with 112g of potassium hydroxide, the organic solvent is replaced with 2L of chlorobenzene, the heating temperature is adjusted to 180℃, and the reaction time is adjusted to 2 hours, to obtain dye intermediate A with a yield of 90.5%.
[0038] In step S2, the organic solvent was replaced with 2.5 L of dichloromethane, and the reaction was carried out under pressure at 50 °C for 12 hours. The yield of a high-weather-resistant dye was 85.8%.
[0039] Example 5
[0040] The difference between Example 5 and Example 1 is that in step S1, the organic solvent is a mixture of 2L of DMF and chlorobenzene, wherein the volume ratio of DMF to chlorobenzene is 1:1, the heating temperature is 170°C, the reaction time is 2 hours, and dye intermediate A is obtained with a yield of 93.8%.
[0041] In step S2, the catalyst was a mixture of 69g potassium carbonate and 163g cesium carbonate, the heating temperature was 115℃, and the reaction time was 7.5 hours. The yield of a high-weather-resistant dye was 89.0%.
[0042] Example 6
[0043] The difference between Example 6 and Example 1 is that in step S1, the alkaline substance used is a mixture of 48g sodium hydride and 20g sodium hydroxide, the organic solvent is 2L NMP, the heating temperature is adjusted to 155°C, and the reaction time is adjusted to 2.5 hours, to obtain dye intermediate A with a yield of 92.5%.
[0044] In step S2, a mixed solvent of 1.5 L DMF and 1 L chlorobenzene was used as the organic solvent, 138 g potassium carbonate was used as the catalyst, the heating temperature was 105 °C, and the reaction time was 8 hours. The yield of a high weather-resistant dye was 87.0%.
[0045] The preparation conditions and yields of Examples 1-6 are shown in Table 1 below: Table 1
[0046] As can be seen from Examples 1-6 and Table 1, the target product can be obtained in high yield within a wide process parameter window. Furthermore, the high weather-resistant dyes obtained in Examples 1-6 all exhibit excellent and stable high performance, proving the reliability of this synthetic route.
[0047] Application examples Application Example 1 Weigh 100g of polyethylene terephthalate resin, 0.4g of the high-weather-resistant dye prepared in Example 1, 0.5g of antioxidant 1010, and 0.5g of ultraviolet absorber UV-326. Mix all components in a high-speed mixer for 5 minutes, then melt-blend, extrude, and cast using a twin-screw extruder at 265–285°C. Subsequently, produce films or sheets through a biaxial stretching process. The resulting products have uniform color. After 1500 hours of xenon lamp aging test, the film shows a color difference change ΔE < 1.5 and a yellowing index (ΔYI) change < 1.0, exhibiting excellent optical stability and weather resistance, making it suitable for display screen protective films, optical packaging, and other fields.
[0048] Application Example 2 100g of polybutylene terephthalate resin was thoroughly dry-mixed with 0.6g of the high-weather-resistant dye prepared in Example 3, and then melt-mixed and granulated using a twin-screw extruder at 235-250℃. The resulting colored PBT granules were dried at 120℃ for 4 hours and then injection-molded into electronic connectors. The products exhibited bright colors and excellent heat resistance. Furthermore, after 1000 hours of high-temperature and high-humidity testing at 85℃ / 85% relative humidity, no visible color change was observed, and the color difference ΔE < 1.5, demonstrating the dye's resistance to damp heat and migration.
[0049] Application Example 3 100g of high-density polyethylene, 0.3g of the high-weather-resistant dye prepared in Example 2, and 0.03g of carbon black were mixed. The mixture was directly extruded into outdoor yellow HDPE profiles using a single-screw extruder at 170-190℃. These profiles exhibit uniform color and excellent weather resistance; after two years of natural outdoor exposure, their color retention rate remains above 90%, superior to ordinary colored profiles, making them suitable for outdoor railings, pergolas, and other architectural and landscape materials.
[0050] Application Example 4 100g of polyethylene terephthalate resin was mixed with 0.2g of the high weather-resistant dye prepared in Example 5, and the mixture was melt-extruded and cast into sheets using a twin-screw extruder at 260-280°C. The sheets were then biaxially stretched at 90-110°C to obtain a 12μm thick yellow BOPET packaging film. The film exhibits pure color and good transparency, and its extract content is low, meeting food packaging hygiene standards. Furthermore, it demonstrates excellent lightfastness, effectively protecting the contents from light exposure.
[0051] Application Example 5 100g of polyamide 6 chips were mixed with 0.8g of the high weather-resistant dye prepared in Example 6, and the moisture was removed by vacuum drum drying. The dried mixture was then melt-spun at 245-260℃ to obtain yellow PA6 industrial filaments. This fiber has high color fastness, is resistant to abrasion and light, and is suitable for producing industrial textiles such as outdoor ropes, tarpaulins, and sports turf that require long-term exposure to sunlight.
[0052] Application Example 6 Five portions of the high-weather-resistant dye prepared in Example 4 were premixed with 100g of polyester resin, 30g of barium sulfate, 1g of leveling agent, and other additives. The mixture was then melt-extruded, pressed into sheets, crushed, ground, and sieved to obtain a yellow outdoor powder coating. This powder coating was electrostatically sprayed onto an aluminum alloy substrate and cured at 200°C for 15 minutes to form a coating layer. The coating exhibited a rich color and high gloss. After passing a 6000-hour neutral salt spray test and a 3000-hour QUV accelerated aging test, the gloss retention rate was >90%, and the color difference ΔE < 3.0, making it suitable for coating high-end aluminum profiles and outdoor facilities.
[0053] The processing methods and performance results of Application Examples 1-6 are shown in Table 2 below: Table 2
[0054] As can be seen from Application Examples 1-6 and Table 2, the high weather-resistant dyes prepared in Examples 1-6 exhibit excellent compatibility and coloring effects in various synthetic resins and coating systems. In their applications, these dyes impart excellent weather resistance, lightfastness, and color fastness to products, meeting the technical requirements of high-end fields such as automotive, electronics, outdoor construction, and food packaging.
[0055] Comparative Example Comparative Example 1 Commercially available solvent Yellow 33 was physically mixed with twice the mass of UV absorber UV-P, and then added to 100g of PET resin at a dosage of 0.4g. The mixture was then melt-blended using a twin-screw extruder at 265–285°C, and subsequently formed into a film via biaxial stretching. After 500 hours of xenon lamp aging, the color difference ΔE of this sample was greater than 6.0. This indicates that the physically blended dye and stabilizer system lacks compatibility and thermal stability at PET processing temperatures and cannot form effective intramolecular synergistic protection, resulting in limited and short-lasting photoaging resistance.
[0056] Comparative Example 2 A pyridine-free analog dye was synthesized according to the method of Example 3 by replacing 1-[(6-ethoxy-3-pyridyl)methyl]-4-piperidineamine with 1-methyl-4-piperidineamine. When used for coloring PBT connectors, the color difference ΔE was 4.2 after 1000 hours of testing at 85°C / 85%RH, significantly lower than that of Application Example 2 (ΔE < 1.5), demonstrating that the ethoxypyridine group is crucial for improving durability.
[0057] Comparative Example 3 A commercially available high-performance perylene yellow dye was selected and applied at a dosage of 0.3g to 100g of HDPE profile. After one year of outdoor exposure, the color retention rate was only about 75%, far lower than the over 90% of Application Example 3, indicating that the dye of this invention has a significant advantage in long-term weather resistance.
[0058] Comparative Example 4 The synthesis steps were followed as in Example 1, but the molar ratio of amines in the second step was reduced to 1:2. The resulting product yield was less than 70%, and its heat resistance was poor when used in PET film, exhibiting significant discoloration during stretching. This demonstrates that sufficient amine feed is crucial for ensuring complete reaction and product performance.
[0059] Comparative Example 5 The dye was synthesized by replacing 5-bromo-4-fluoroindocyanine anhydride with 5,7-difluoroindocyanine anhydride. The resulting dye exhibited insufficient thermal stability during PA6 spinning, decomposing at 290°C and causing fiber discoloration, indicating that a specific halogen substitution mode has a significant impact on the dye's heat resistance.
[0060] Comparative Example 6 No alkaline substance was added in step S1, and other conditions were the same as in Example 1. The reaction was almost impossible to proceed, a large amount of the raw materials were recovered, and the yield of intermediate A was less than 10%, proving that an alkaline environment is an indispensable condition for the condensation reaction to occur.
[0061] The test conditions and performance results for Comparative Examples 1-6 are shown in Table 3 below: Table 3
[0062] As can be seen from Examples 1-6, Comparative Examples 1-6, and Table 3, the high weather-resistant dyes prepared in Examples 1-6 are superior to the comparative examples in terms of synthesis yield, lightfastness, weather resistance, heat resistance, and processing stability. This chemically bonded dye effectively solves the defect of poor weather resistance in dyes.
[0063] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A highly weather-resistant dye, characterized in that, It has the following structural formula: 。 2. The high weather-resistant dye according to claim 1, characterized in that, It is prepared by the following reaction: ， 。 3. A method for preparing a high weather-resistant dye according to any one of claims 1-2, characterized in that, Includes the following steps: S1. 5-Bromo-4-fluoroindorubicin anhydride, 2,4-dichloro-7-methylquinoline, alkaline substances and organic solvents are added to a reaction vessel and stirred. After the reaction is completed, the reaction solution is poured into ethanol, extracted with organic solvent, rotary evaporated and dried to obtain dye intermediate A. S2. Dye intermediate A is reacted with 1-[(6-ethoxy-3-pyridyl)methyl]-4-piperidinamine, organic solvent and catalyst under heating conditions. After the reaction is completed, the reaction solution is poured into water for separation. The obtained solid is filtered, recrystallized and dried to obtain a high weather-resistant dye.
4. The method for preparing a high weather-resistant dye according to claim 3, characterized in that: In step S1, the molar ratio of 5-bromo-4-fluoroindorubicin anhydride to 2,4-dichloro-7-methylquinoline is (1-1.2):
1.
5. The method for preparing a high weather-resistant dye according to claim 3, characterized in that: In step S1, the alkaline substance is one or more of NaH, NaOH, and KOH.
6. The method for preparing a high weather-resistant dye according to claim 3, characterized in that: In step S1, the heating temperature is 150-180℃ and the reaction time is 2-3 hours.
7. The method for preparing a high weather-resistant dye according to claim 3, characterized in that: In step S2, the molar ratio of dye intermediate A to 1-[(6-ethoxy-3-pyridyl)methyl]-4-piperidineamine is 1:(4-4.5).
8. The method for preparing a high weather-resistant dye according to claim 3, characterized in that: In step S2, the catalyst is one or more of potassium carbonate and cesium carbonate.
9. The method for preparing a high weather-resistant dye according to claim 3, characterized in that: In step S2, the heating temperature is 100-120℃ and the reaction time is 6-8 hours.
10. The application of a high weather-resistant dye according to any one of claims 1-2, characterized in that: Colored plastic products are obtained by melt mixing, granulation, and molding of the high weather-resistant dye and plastic resin.