Synthesis method of plant extract cardanol modified triazine ultraviolet absorbent

Abstract

The invention relates to the technical field of ultraviolet absorbents, in particular to a synthesis method of a hexafluoropropylene oxide tripolymer, which comprises the following steps: S1, carrying out reaction on cyanuric chloride and aromatic hydrocarbon to obtain an intermediate product 1-chloro-3, 5-diaryltriazine, S2, carrying out reaction on cardanol and nitric acid to generate an intermediate product nitro cardanol, S3, carrying out reaction on 1-chloro-3, 5-diaryltriazine and 1-chloro-3, 5-diaryltriazine, and carrying out reaction on 1-chloro-3, 5-diaryltriazine and 1-chloro-3, 5-diaryltriazine to obtain the hexafluoropropylene oxide tripolymer. The preparation method comprises the following steps: (1) reacting 2, 5-diaryltriazine with nitrocardanol to obtain an intermediate product A, (2) reacting the intermediate product A with active iron powder and diluted hydrochloric acid to obtain an intermediate product B, and (3) continuously stirring the intermediate product B with sodium nitrite, nitrous acid and diluted hydrochloric acid to react, and adding a reducing agent and heating after the reaction is finished to obtain the target product cardanol modified triazine ultraviolet absorbent. The synthesis method of the triazine ultraviolet absorbent provided by the invention has the advantages of simple reaction conditions, green production and high weather resistance of the product.

Description

Technical Field

[0001] The present application relates to the technical field of ultraviolet absorbers, and in particular to a method for synthesizing a triazine ultraviolet absorber modified with plant extract cardanol. Background Art

[0002] Ultraviolet absorbers are light stabilizers that absorb the ultraviolet portion of sunlight and fluorescent light sources without changing themselves. Under sunlight and fluorescent light, polymer materials undergo auto-oxidation due to the effects of ultraviolet light, leading to degradation and deterioration of the polymer, resulting in a decrease in appearance and mechanical properties. The addition of ultraviolet absorbers selectively absorbs ultraviolet light, converting it into harmless energy that is released or consumed. Ultraviolet absorbers can be categorized by their structure into benzophenones, salicylates, triazines, benzotriazoles (also known as benzotriazoles), and substituted acrylonitriles. Ultraviolet absorbers are widely used in a variety of products, including plastics, coatings, textiles, and care products, as well as in the development of UV-resistant fibers and clothing.

[0003] Chinese invention patent publication number CN118146168A discloses a triazine ultraviolet absorber and its synthesis method. Using cyanuric chloride and p-nitrobenzoic acid as raw materials, a new compound 4-((4-((4-aminoformylphenyl)amino)-6-(4-methoxyphenyl)-1,3,5-triazin-2-yl)amino)benzoic acid octyl ester is obtained through Friedel-Crafts reaction, esterification reaction, reduction reaction and aminolysis reaction.

[0004] When producing triazine ultraviolet absorbers, this technical solution not only has a complicated synthesis process and requires the use of more raw materials and steps, but also uses tetrahydrofuran, which is highly toxic, in the raw materials, which is not in line with the current general direction of green production. At the same time, the ultraviolet absorbers produced by this technical solution have poor weather resistance and tend to turn yellow when exposed to sunlight for a long time, affecting the appearance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for synthesizing a triazine ultraviolet absorber with simple reaction conditions, green production and strong weather resistance of the product.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: A method for synthesizing a triazine ultraviolet absorber modified with cardanol, a plant extract, comprises the following steps: S1: Add cyanuric chloride and organic solvent to the reactor. After they are completely dissolved, add alkaline catalyst and slowly drop aromatic hydrocarbon under stirring and heating to obtain the intermediate product 1-chloro-3,5-diaryltriazine. S2: Mix cardanol with 20% nitric acid, continue stirring under heating conditions to react, and then steam distill to obtain the intermediate product nitrocardanol. S3: Add 1-chloro-3,5-diaryltriazine and organic solvent to the reactor, add metal catalyst after complete dissolution, slowly add nitrocardanol dropwise under stirring and heating conditions to react to obtain intermediate product A. S4: Add intermediate product A, activated iron powder and dilute hydrochloric acid to the reactor, and react under stirring and heating conditions to obtain intermediate product B. S5: Add the intermediate product B, sodium nitrite, nitrous acid and dilute hydrochloric acid to the reactor, continue stirring to react, add a reducing agent after the reaction is completed, and heat to obtain the target product, cardanol-modified triazine ultraviolet absorber.

[0007] By adopting the above technical solution, the main purpose of this technical solution is to use the long carbon chain on the benzene ring of cardanol to replace the alkoxy group on the benzene ring of traditional triazine ultraviolet absorbers, thereby achieving the effects of modification and green production.

[0008] Traditional triazine absorbers are generally prepared by grafting two benzene rings on a triazine ring, then subjecting the intermediate product to a substitution reaction with resorcinol, connecting resorcinol to the triazine ring, and finally reacting alkyl sodium with the hydroxyl group to generate a triazine ultraviolet absorber. In the first step, when the triazine ring reacts with benzene, a Grignard reagent is required. This not only results in high reaction costs, but also harsh reaction conditions, making it difficult to achieve large-scale industrial production. When the alkyl sodium reacts with the intermediate product to generate the target product, the reaction endpoint is difficult to control, and a large number of by-products are easily produced, resulting in low purity and yield of the final product and high production costs. The cardanol used in this technical solution is a type of grain or plant-derived product extracted from cashew nut shell liquid (CNSL). Natural phenolic compounds, as a natural plant extract, have lower material costs than traditional production methods. At the same time, this technical solution uses tripolyazine chloride to react with aromatic hydrocarbons to connect the benzene ring to the triazine ring. Compared with the traditional synthesis method, only an alkaline catalyst is required, and the reaction conditions are simpler. When connecting cardanol to the triazine ring, in order to increase the selectivity of the reaction position and reduce the production of by-products, this technical solution uses a diazotization reaction to first replace a nitro group on the benzene ring of cardanol, and then react the intermediate product with the triazine ring, thereby improving the selectivity of the reaction and significantly increasing the yield of the ortho-substituted product of cardanol, thereby improving the purity and yield of the reaction product and reducing production costs.

[0009] Triazine UV absorbers are often added to products such as plastics, coatings, and cosmetics. However, due to the presence of alkoxy groups in triazine UV absorbers, such UV absorbers not only have obvious photodegradation effects and poor weather resistance, but are also prone to yellowing and reduced UV absorption capacity under long-term exposure to light sources. At the same time, due to the presence of alkoxy groups, the dispersion effect in resins and rubber materials is poor, which makes the use scope of such UV absorbers relatively small. The present technical solution uses cardanol as a raw material, so that the original alkoxy groups in the final product are replaced by the long carbon chain of cardanol. The carbon chain is more stable, so that the triazine UV absorber produced by the present technical solution has stronger weather resistance and can still maintain whiteness under long-term light exposure. At the same time, the presence of the long carbon chain makes the triazine UV absorber produced by the present technical solution easier to disperse in polyester materials, thereby expanding the scope of use.

[0010] In the present invention, the aromatic hydrocarbons in step S1 include one or a combination of benzene, toluene, and m-xylene.

[0011] Through the above technical solution, in this technical solution, benzene, toluene, m-xylene and cyanuric chloride are subjected to a substitution reaction to connect aromatic groups to the triazine ring, so that the ultraviolet absorber produced by this technical solution has strong dispersibility in polyester materials.

[0012] In the present invention, the aromatic hydrocarbon in step S1 is m-xylene.

[0013] Through the above technical solution, in this technical solution, since m-xylene has more methyl groups, the ultraviolet absorber produced using m-xylene as raw material has stronger dispersibility in polyester materials.

[0014] In the present invention, the cardanol in step S2 includes one or more combinations of cardanol and cardanol diphenol. The structure of the cardanol is shown below: (R=-C 15 H 31-2n , where n = 0 to 3) The structure of the cashew nut diphenol is shown below: (R=C 15 ~C 17 , containing 1-3 double bonds).

[0015] Through the above technical solution, cardanol, as a type of natural phenolic compound of cereal or plant origin extracted from cashew nut shell liquid (CNSL), is in line with the current general direction of green production. Since cardanol contains a variety of biophenols, this technical solution uses cashew monophenol and cashew diphenol, so that in the final product, the long carbon chain on cardanol or cashew diphenol replaces the methoxy group on the benzene ring of the traditional triazine ultraviolet absorber, so that the ultraviolet absorber produced by this technical solution has better weather resistance. At the same time, due to the position of the substituents on the benzene ring of cardanol and cashew diphenol, they have better selectivity when undergoing substitution reaction with the triazine ring, thereby improving the purity of the final product.

[0016] In the present invention, the cardanol in step S2 is cardanol.

[0017] Through the above technical solution, since cashew diphenol has two hydroxyl groups on the benzene ring, when it reacts with cyanuric chloride, the positioning effect is more obvious and the by-product content is lower.

[0018] In the present invention, the organic solvent in step S1 is one or a combination of dichloroethane, carbon tetrachloride and liquid paraffin.

[0019] Through the above technical solution, in this technical solution, when the aromatic hydrocarbon and tripolyazine chloride undergo nucleophilic substitution, the use of a non-polar organic solvent can reduce the influence of the solvent on the reaction and make the reaction more stable.

[0020] In the present invention, the reaction temperature in step S2 is 20-30°C.

[0021] According to the above technical solution, since nitrous acid and sodium nitrite are easily decomposed by heat to produce harmful gases, the reaction temperature needs to be maintained in a relatively low range in this technical solution to reduce the decomposition of nitrous acid and sodium nitrite.

[0022] In the present invention, the reducing agent in step S5 is one or a combination of phosphorous acid and hypophosphorous acid.

[0023] According to the above technical solution, when removing the amino group on the benzene ring, adding a reducing agent can accelerate the reaction rate, thereby improving the reaction efficiency and making the reaction more thorough.

[0024] The synthetic method of the present invention has the following beneficial effects: 1. The cardanol used in this technical solution is a type of natural phenolic compound derived from cereals or plants extracted from cashew nut shell liquid (CNSL). As a natural plant extract, its material cost is lower than that of traditional production methods. 2. By using cardanol as a raw material, the present technical solution replaces the original alkoxy group in the final product with the long carbon chain of cardanol, and the carbon chain is more stable, so that the triazine ultraviolet absorber produced by the present technical solution has stronger weather resistance; 3. When connecting cardanol to the triazine ring, in order to increase the selectivity of the reaction position and reduce the generation of by-products, the present technical solution uses a diazotization reaction to first replace a nitro group on the benzene ring of cardanol, and then react the intermediate product with the triazine ring, thereby improving the selectivity of the reaction and significantly increasing the yield of the ortho-substituted product of cardanol.

[0025] Generally, the present invention recommends the following steps to synthesize triazine UV absorbers: S1: Add cyanuric chloride and dichloroethane to the reactor. After they are completely dissolved, add alkaline catalyst and slowly dropwise add m-xylene under stirring and heating conditions to obtain the intermediate product 1-chloro-3,5-di-m-xylyltriazine. S2: Mix cashew nut diphenol with 20% nitric acid, continue stirring under heating conditions to react, and then steam distill to obtain the intermediate product nitro-cashew nut diphenol. S3: Add 1-chloro-3,5-di-m-xylyltriazine and dichloroethane to the reactor, add aluminum chloride after they are completely dissolved, and slowly add nitro-cashew diphenol dropwise under stirring and heating conditions to react to obtain intermediate product A. S4: Add intermediate product A, activated iron powder and dilute hydrochloric acid to the reactor, and react under stirring and heating to obtain intermediate product B. S5: Add the intermediate product B, sodium nitrite, nitrous acid and dilute hydrochloric acid to the reactor, continue stirring to react, and after the reaction is completed, add hypophosphorous acid and heat to obtain the target product, cardanol-modified triazine ultraviolet absorber. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a liquid chromatogram of the finished product of Example 1 of the method for synthesizing a triazine ultraviolet absorber modified with cardanol, a plant extract, in the present application.

[0027] Figure 2 This is a liquid chromatogram of the finished product of Comparative Example 1 of the synthesis method of a triazine ultraviolet absorber modified with cardanol, a plant extract, in the embodiment of the present application.

[0028] Figure 3 This is the nuclear magnetic resonance image of the finished product of Example 1 of the synthesis method of a triazine ultraviolet absorber modified with cardanol, a plant extract, in the present application. DETAILED DESCRIPTION

[0029] The present invention will be further described below through specific implementation methods, but the protection scope of the present invention is not limited thereto.

[0030] Preparation Example 1: S1: Add 184.5g of cyanuric chloride (1mol) and 500ml of dichloroethane to the reactor. After complete dissolution, add 20g of sodium hydroxide. Stir at 60-80°C and slowly add 265g of m-xylene (2.5mol) dropwise to obtain the intermediate product 1-chloro-3,5-di-m-xylyltriazine. S2: 380 g of cardamom diphenol (1.2 mol) was mixed with 500 ml of 20% nitric acid, and the mixture was stirred at 25° C., and then steam distilled to obtain the intermediate product nitro-cardamom diphenol. S3: Add 1-chloro-3,5-di-m-xylyltriazine obtained in step S1 and 500 ml of dichloroethane to the reactor. After complete dissolution, add 20 g of aluminum chloride. Slowly dropwise add the nitro-cashew diphenol obtained in step S2 under stirring and heating conditions to react and obtain intermediate product A. S4: Add intermediate product A, 10g active iron powder and 500ml dilute hydrochloric acid to the reactor and react under stirring and heating to obtain intermediate product B. S5: Add the intermediate product B, 500 ml of sodium nitrite nitrite solution and 100 ml of dilute hydrochloric acid to the reactor, continue stirring to react, and after the reaction is completed, add 50 g of hypophosphorous acid and heat to obtain the target product, cardanol-modified triazine ultraviolet absorber.

[0031] The difference between Preparation Example 2 and Preparation Example 1 is that the raw material selected in Step S2 of Preparation Example 2 is cashew nut monophenol.

[0032] The difference between Preparation Example 3 and Preparation Example 1 is that the raw material selected in Step S1 of Preparation Example 3 is toluene.

[0033] The difference between Preparation Example 4 and Preparation Example 1 is that the raw material selected in Step S1 of Preparation Example 4 is benzene.

[0034] The difference between Preparation Example 5 and Preparation Example 1 is that in Preparation Example 5, no reducing agent is added in step S5.

[0035] The difference between Preparation Example 6 and Example 1 is that cardanol is not subjected to diazotization reaction treatment. The specific process is as follows: A1: Add 184.5g of cyanuric chloride (1 mol) and 500ml of dichloroethane to a reactor. After complete dissolution, add 20g of sodium hydroxide. Stir at 60-80°C and slowly add 265g of m-xylene (2.5 mol) dropwise to obtain the intermediate product 1-chloro-3,5-di-m-xylyltriazine. A2: Add 1-chloro-3,5-di-m-xylyltriazine obtained in step S1 and 500 ml of dichloroethane to the reactor. After complete dissolution, add 20 g of aluminum chloride. Slowly add cardanol dropwise under stirring and heating conditions to react to obtain the target product, cardanol-modified triazine UV absorber. The difference between Preparation Example 7 and Preparation Example 6 is that the raw material selected in Step A2 is cashew nut monophenol.

[0036] The modified polyester particles were prepared by mixing the various examples and comparative examples in the proportions shown in the following table: The adhesive is polyurethane resin, and the dispersant is composed of sodium hexametaphosphate and glyceryl stearate in a weight ratio of 1:2. Both the adhesive and the dispersant do not have ultraviolet absorption function.

[0037] The difference between Comparative Example 3 and Example 1 is that Comparative Example 3 is a commercially available triazine ultraviolet absorber.

[0038] Detection method Liquid chromatography was used to analyze the products of each preparation example to obtain the purity and yield of each product.

[0039] The modified polyester particles prepared in each embodiment and comparative example were melt-drawn and then woven into fabrics for ultraviolet irradiation experiments to obtain the ultraviolet absorption rates of each embodiment and comparative example.

[0040] The modified polyester particles prepared in each embodiment and comparative example were melt-drawn and then woven into fabrics for a long-term ultraviolet irradiation experiment to observe the color changes of each embodiment and comparative example.

[0041] The test results are shown in the following table: Conclusion: Pass Figure 3 The NMR spectrum shows that the structure of the triazine ultraviolet absorber prepared in this application is as follows: Conclusion: According to the data of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 in the above table, when synthesizing triazine ultraviolet absorbers, the raw material cardanol is first subjected to diazotization treatment, and a nitro group is first substituted on the benzene ring of cardanol, and then the intermediate product is reacted with the triazine ring to improve the selectivity of the reaction, so that the yield of the ortho-substituted product of cardanol is greatly increased, thereby improving the purity and yield of the reaction product. However, in the traditional synthesis method, there is no such treatment step, which makes the yield and purity of the traditional synthesis method low. At the same time, the yield and purity of the product using cashew diphenol as the raw material are greater than the yield and purity of the product using cashew monophenol as the raw material. This is due to the positioning effect of the two hydroxyl groups on cashew bisphenol, which makes it more determined when it undergoes a substitution reaction with the triazine ring. There is only one hydroxyl group on the benzene ring of cashew monophenol, and the positioning is not obvious. It is easy to produce more by-products during the reaction, and a diazotization reaction is needed to achieve the positioning effect.

[0042] Conclusion: It can be seen from the data of Example 1, Example 3, and Example 4 in the above table that in the present technical solution, the product purity of the raw material selected from m-xylene is greater than the product purity of the raw material selected from benzene, which is greater than the product purity of the raw material selected from toluene. This is because more kettle products are produced when toluene participates in the reaction, which reduces the purity of the final product. Therefore, the aromatic hydrocarbon in the present technical solution is preferably m-xylene.

[0043] Conclusion: It can be seen from the data of Example 1 and Example 5 in the above table that the purity and yield of the product are significantly increased after the reducing agent is added in step 5 of the present technical solution. This is because the presence of the reducing agent can accelerate the decomposition of the substituents on the benzene ring, which is more efficient than thermal decomposition.

[0044] Conclusion: According to the data of Example 1 and Comparative Example 3 in the above table, the triazine ultraviolet absorber produced by the present technical solution has not only a lower ultraviolet transmittance but also a higher horizontal recovery angle than the commercially available triazine ultraviolet absorber. This shows that the triazine ultraviolet absorber produced by the present technical solution has a relatively excellent ultraviolet absorption function and meets the requirements on the market.

[0045] Conclusion: According to the data of Example 1 and Example 2 in the above table, when the triazine ultraviolet absorber is produced by the present technical solution, the ultraviolet absorption function of the ultraviolet absorber produced by using cashew diphenol as the raw material is better than that of the ultraviolet absorber produced by using cashew monophenol as the raw material. This is because the principle of triazine ultraviolet absorption by the ultraviolet absorber is that the hydroxyl group on the benzene ring and the triazine ring form a chelate ring composed of intramolecular hydrogen bonds. After absorbing ultraviolet light, the intramolecular hydrogen bonds are destroyed to form unstable high-energy ionic compounds. When not exposed to ultraviolet light, the excess energy is released to restore the original low-energy stable state, thereby absorbing ultraviolet light. Therefore, the ultraviolet absorption function of the ultraviolet absorber produced by using cashew diphenol containing two hydroxyl groups on the benzene ring as the raw material is better.

[0046] Conclusion: Through Example 1, Example 3 and Example 4 in the above table, the ultraviolet absorption function of the ultraviolet absorber produced by using m-xylene as raw material in this technical solution is relatively excellent. This is because there are more methyl groups on m-xylene, which makes the final product more evenly distributed on the polyester particles, thereby improving the ultraviolet absorption function. 12 hours 24 hours 48 hours Example 1 white white Yellowing Comparative Example 3 white Yellowing Obvious yellowing

[0047] Conclusion: From the data of Example 1 and Comparative Example 3 in the above table, it can be seen that the triazine ultraviolet absorber produced by the present technical solution can still maintain white under long-term ultraviolet irradiation, and does not turn yellow until 48 hours of continuous irradiation, compared with the commercially available triazine ultraviolet absorber. The commercially available triazine ultraviolet absorber turns yellow after 24 hours of irradiation, and the yellow color is very obvious after 48 hours of continuous irradiation, indicating that the triazine ultraviolet absorber produced by the present technical solution has excellent weather resistance and can be used for objects that need to be exposed to sunlight for a long time. This is because by using cardanol as a raw material, the original alkoxy group in the final product is replaced by the long carbon chain of cardanol, and the carbon chain is more stable, which makes the triazine ultraviolet absorber produced by the present technical solution have stronger weather resistance.

[0048] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for synthesizing a triazine ultraviolet absorber modified with cardanol, a plant extract, characterized in that: The steps include: S1: Add cyanuric chloride and organic solvent to the reactor. After they are completely dissolved, add alkaline catalyst and slowly drop aromatic hydrocarbon under stirring and heating conditions to obtain the intermediate product 1-chloro-3,5-diaryltriazine. S2: Mix cardanol with 20% nitric acid, continue stirring under heating conditions to react, and then steam distill to obtain the intermediate product nitrocardanol. S3: Add 1-chloro-3,5-diaryl triazine and an organic solvent to the reactor, add a metal catalyst after they are completely dissolved, and slowly drop nitrocardanol under stirring and heating conditions to react to obtain an intermediate product A. S4: Add intermediate product A, active iron powder and dilute hydrochloric acid to the reactor, and react under stirring and heating conditions to obtain intermediate product B. S5: Add the intermediate product B, sodium nitrite, nitrous acid and dilute hydrochloric acid into the reactor, continue to stir and react, add a reducing agent after the reaction is completed and heat to obtain the target product, cardanol-modified triazine ultraviolet absorber.

2. The method for synthesizing a triazine ultraviolet absorber modified with cardanol, a plant extract, according to claim 1, characterized in that: The aromatic hydrocarbons in step S1 include one or a combination of benzene, toluene and m-xylene.

3. The method for synthesizing a triazine ultraviolet absorber modified with cardanol, a plant extract, according to claim 2, characterized in that: The aromatic hydrocarbon in step S1 is m-xylene.

4. The method for synthesizing a triazine ultraviolet absorber modified with cardanol, a plant extract, according to claim 1, characterized in that: The cardanol in step S2 includes one or more combinations of cardanol and cardanol diphenol, and the structure of the cardanol is as follows: (R=-C 15 H 31-2n , where n = 0 to 3) The structure of the cashew nut diphenol is shown below: (R=C 15 ~C 17 , containing 1-3 double bonds).

5. The method for synthesizing a triazine ultraviolet absorber modified with cardanol, a plant extract, according to claim 4, characterized in that: The cardanol in step S2 is cardanol.

6. The method for synthesizing a triazine ultraviolet absorber modified with cardanol, a plant extract, according to claim 1, characterized in that: The organic solvent in step S1 is one or a combination of ethylene dichloride, carbon tetrachloride and liquid paraffin.

7. The method for synthesizing a triazine ultraviolet absorber modified with cardanol, a plant extract, according to claim 1, characterized in that: The metal catalyst in step S3 is one or a combination of aluminum chloride, ferric chloride and aluminum bromide.

8. The method for synthesizing a triazine ultraviolet absorber modified with cardanol, a plant extract, according to claim 1, characterized in that: The reaction temperature in step S2 is 20-30°C.

9. The method for synthesizing a triazine ultraviolet absorber modified with cardanol, a plant extract, according to claim 1, characterized in that: The reducing agent in step S5 is one or a combination of phosphorous acid and hypophosphorous acid.

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