Method for green synthesis of triazine ultraviolet light absorber

Abstract

The invention relates to the field of ultraviolet light absorbers, in particular to a novel method for synthesizing a s-triazine ultraviolet light absorber. The synthesis of the triazine ultraviolet light absorber is accompanied by the generation of a large amount of impurities, a large amount of solvent is needed for recrystallization in the post-treatment process, and the impurities generated by synthesis are removed in a reaction cup by using an easily separated mixed solvent.

Description

Technical Field

[0001] The invention relates to the field of ultraviolet absorbers in the field of polymer material additives, and in particular to a method for green synthesis of triazine ultraviolet absorbers. Background Art

[0002] Triazine UV absorbers have been a hot topic in recent years. Triazine UV absorbers have the characteristics of high efficiency, low color, high processing temperature, good compatibility, etc., and have very broad market prospects. At present, the synthesis process of triazine UV absorbers has the problem of more product impurities, and a large amount of solvents need to be used for recrystallization and other methods for purification; and the use of a large amount of solvents will lead to the generation of a large amount of hazardous waste and some products cannot be effectively recycled. At the same time, a large amount of solvents are used in the process of recycling and application, which requires a lot of energy for distillation recovery, thereby further deepening the waste of energy and environmental pollution. Summary of the invention

[0003] As a better implementation mode of the present invention, the molar ratio of intermediate I, catalyst or acid binding agent, and substrate is 1:0.5-1.1:0.8-1.33.

[0004] Based on the common sense in this field, the various conditions in the above schemes can be combined with each other to obtain the best embodiment of the present invention.

[0005] All raw materials and reagents involved in the present invention can be obtained commercially.

[0006] Compared with the prior art, the present invention has the following advantages: (1) Multiple recrystallization is no longer required, reducing the generation of organic waste liquid and energy consumption; (2) Reduce product loss and indirectly increase product yield. Implementation

[0007] The present invention is further described below with reference to examples, but the scope of protection claimed by the present invention is not limited to the scope described in the examples.

[0008] Example 1: A green synthesis method for triazine ultraviolet absorbers (UV1577) In a 1L four-necked bottle equipped with a stirrer, a condenser and a thermometer, 50 g of intermediate I of UV1577 (a homemade product), 200 g of xylene, 200 g of dichloroethane, 100 g of ethanol and 0.5-5 g of PEG2000 were added and stirred, and then the temperature was raised to 80-90°C after stirring; After the mixture is almost completely dissolved, 2.5 g of activated carbon is added and hot filtration is performed to remove the tarry impurities and impurities insoluble in the mixed solvent; After hot filtration, cool to 25-35°C, add 27.5 g of potassium carbonate and 29.0 g of bromohexane; After the addition is completed, the temperature is raised to 120-130°C, during which dichloroethane and ethanol are evaporated, and the temperature is maintained for 2-3 hours, then the temperature is lowered to 70-80°C; After the temperature is lowered, 2.5 g of activated carbon is added, and hot filtration is performed again to remove the generated salt and the added carbon; The temperature was then lowered to 12-15°C, maintained for 1-2 hours, and then filtered and dried to obtain 31.33 g of light yellow solid, which was UV1577. HPLC content: 98.8%, 500nm transmittance met the commercial requirements: greater than 98%.

[0009] Example 2: A green synthesis method for triazine ultraviolet absorbers (UV1164) In a 1L four-necked bottle equipped with a stirrer, a condenser and a thermometer, intermediate I of UV1164 (a homemade product), 150 g of N,N-dimethylformamide (DMF), 100 g of n-hexane, 0.5-5 g of tetrabutylammonium bromide, 27.5 g of potassium carbonate and 29.0 g of bromooctane were added and stirred. After stirring, the temperature was raised to 115-120°C, and the temperature was maintained for 2-3 h. Then, the temperature was lowered to 70-80°C, 2.5 g of activated carbon was added, and hot filtration was performed to filter out the generated salt and the added carbon; After hot filtration, cool down to 45-50℃, keep it at this temperature and let it stand for 1 hour before separating the liquids. Separate the DMF layer containing the product at the bottom and take out the n-hexane containing tarry impurities at the top as the waste liquid, which can be recovered and reused after simple distillation. The DMF layer was further cooled to 12-15 °C and kept for 1-2 hours before being filtered and dried to obtain 35.2 g of a light yellow solid, namely UV1164, with an HPLC content of 99.1% and an absorbance at 445 nm that met the commercial requirements: less than 0.3.

[0010] The following points need to be explained: The above description is only a preferred implementation case of the present invention and cannot be used to limit the present invention. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The present invention relates to a method for green synthesis of triazine ultraviolet absorbers. Features: The types of triazine UV absorbers are within the following general formula, specifically as follows: 。 2. A method for synthesizing a green triazine ultraviolet absorber according to claim 1, Features: The intermediate I is used as the main raw material, and reacts with the corresponding substrate to obtain the target product. The intermediate structure that can be selected is the general formula R 5 The substituent is a hydrogen atom, and the substrate that can be selected is a substrate containing R 5 The corresponding compounds of the substituents.

3. A method for synthesizing a green triazine ultraviolet absorber according to claim 1, Features: As a better implementation mode of the present invention, the reaction is carried out in a mixed solvent, and the mixed solvent is divided into a first solvent and a second solvent: wherein the first solvent is one or more of o-dichlorobenzene, chlorobenzene, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, tetrachloroethane, p-dichlorobenzene, nitrobenzene, xylene, toluene, n-hexane, n-heptane, petroleum ether, ethyl acetate, etc. The second solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, methanol, ethanol, isopropanol, n-butanol, tetrahydrofuran; Furthermore, the mass ratio of the mixed solvent to the intermediate I is in the range of (1.5-6):

1.

4. A method for synthesizing a green triazine ultraviolet absorber according to claim 1, Features: The synthesis method dissolves the intermediate I in a mixed solvent, decolorizes the intermediate I in advance, filters out insoluble impurities, and then conducts a synthesis reaction. Part of the intermediate I needs to be separated to remove impurities after synthesis, and then cooled and filtered, and does not require subsequent refining processes such as recrystallization.

5. A method for synthesizing a green triazine ultraviolet absorber according to claim 4, wherein the synthesis method Features: Add intermediate I to the corresponding composite solvent and heat it until it is basically dissolved. Add activated carbon or clay to the system, mix it evenly, perform hot filtration, filter out the solid, then add an acid binding agent or catalyst and a reaction substrate, heat it to the required temperature, and keep it warm for a total of 2-14 hours. Part of the solvent can be recovered during the reaction; Furthermore, the temperature at which the temperature is raised to substantially dissolve is 30-140° C., which varies according to different intermediates I. The standard for substantially dissolving is that the weight of insoluble solid matter is less than 5%; Furthermore, the acid-binding agent or catalyst is one or more of potassium carbonate, sodium carbonate, potassium phosphate, sodium phosphate, potassium tert-butoxide, tetrabutylammonium bromide, PEG (400-20000), crown ether phase transfer catalyst, etc.; Furthermore, the required temperature for the reaction is 15-150°C.

6. A method for synthesizing a green triazine ultraviolet absorber according to claim 4, wherein the synthesis method Features: The molar ratio of the intermediate I, the catalyst or the acid-binding agent, and the substrate is 1:0.5-1.1:0.8-1.33.

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