Synthesis method of plant extract cardanol modified benzophenone ultraviolet absorbent
By replacing the alkoxy group in traditional benzophenone UV absorbers with cashew pills, the problems of high production costs and poor weather resistance are solved, and the lower cost and stronger weather resistance of benzophenone UV absorption is achieved. Agent, suitable for applications that are exposed to sunlight for a long time.
Patent Information
- Application Number
- CN202411234061.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-04
- Publication Date
- 2024-12-10
AI Technical Summary
The existing benzophenone ultraviolet absorbers have high production costs and poor weather resistance, which are prone to yellowing under long-term exposure to sunlight, affecting their aesthetics and use range.
Cassophol is used as raw material to react with benzoic acid derivatives and metal catalysts to form a modified benzophenone-based ultraviolet absorber, replace the alkoxy group in the traditional method, and improve the weather resistance and dispersion of the product.
It reduces production costs, improves the weather resistance of benzophenone-based ultraviolet absorbers, keeps them white under long-term light, and is more easily dispersed in polyester materials, expanding the scope of use.
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Figure CN119100916A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of ultraviolet absorbers, and in particular to a method for synthesizing a benzophenone ultraviolet absorber modified with plant extract cardanol. Background Art
[0002] Ultraviolet light absorbers are a type of light stabilizer that can absorb the ultraviolet light in sunlight and fluorescent light sources without changing themselves. Under sunlight and fluorescence, polymer materials undergo auto-oxidation reactions due to the action of ultraviolet light, which leads to the degradation of polymers and deterioration of appearance and mechanical properties. After adding ultraviolet light absorbers, ultraviolet light can be selectively absorbed, turning it into harmless energy that is released or consumed. Ultraviolet light absorbers can be divided into triazines, salicylates, benzophenones, benzotriazoles (also known as benzotriazoles) and substituted acrylonitriles according to their structures. Ultraviolet light absorbers have been widely used in various products, including plastics, coatings, textiles and care products, and in the development of UV-resistant fibers and clothing.
[0003] A Chinese invention patent with publication number CN112409149A discloses a method for preparing a benzophenone ultraviolet absorber, the method comprising: reacting 2,4-dihydroxybenzophenone and RO-R1 as raw materials to obtain a benzophenone ultraviolet absorber; wherein R is selected from methyl or n-octyl, and R1 is selected from trifluoroacetyl or trifluoromethanesulfonyl.
[0004] This technical solution uses benzophenone and RO-R1 as raw materials when producing benzophenone-based ultraviolet absorbers. The cost of these raw materials is relatively high. At the same time, the ultraviolet absorbers produced by this technical solution contain -OR groups. The presence of these groups makes the ultraviolet absorbers have poor weather resistance and are prone to yellowing when exposed to sunlight for a long time, affecting their appearance. Summary of the invention
[0005] The technical problem to be solved by the present invention is to provide a method for synthesizing a benzophenone ultraviolet absorber with low reaction cost 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 benzophenone ultraviolet absorber modified by plant extract cardanol comprises the following steps: S1: Add benzoic acid derivatives, cardanol and organic solvent to a reactor, mix well and then add a metal catalyst, react for 3-4 hours under stirring and heating conditions, add ice water and concentrated hydrochloric acid to the reactor after the reaction is completed, separate the organic layer from the aqueous layer, wash the organic layer with sodium hydroxide solution and then distill to remove benzene to obtain intermediate product B: S2: Dissolve the intermediate product B in dilute hydrochloric acid, add aluminum chloride and cuprous chloride, continue to introduce CO under stirring and heating conditions for 3-4 hours, adjust the pH to neutral with sodium hydroxide solution after the reaction, and distill to obtain the intermediate product C S3: reacting the intermediate product C with an acidic potassium permanganate solution to obtain the target product, a benzophenone ultraviolet absorber.
[0007] By adopting the above technical scheme, the main purpose of this technical scheme is to use the long carbon chain on the benzene ring of cardanol to replace the alkoxy group on the benzene ring of the traditional benzophenone type ultraviolet absorber, so as to achieve the effect of modification and cost reduction.
[0008] Traditional benzophenone absorbers are generally subjected to substitution reaction using 2,4-dihydroxybenzophenone and RO-R1 as raw materials, so that a methoxy group is connected to the benzene ring, thereby reacting to generate a benzophenone ultraviolet absorber. This reaction is not only difficult to obtain raw materials and has high production costs, but also when synthesizing the target product, both -R and -R1 may be connected to the benzene ring, resulting in a large number of reaction by-products, resulting in a significant decrease in the purity and yield of the product. The cardanol used in the present technical solution is a type of natural phenolic compound from cereals or plants extracted from cashew nut shell liquid (CNSL). As a natural plant extract, the material cost is lower than that of the traditional production method. At the same time, the present technical solution uses benzoic acid derivatives to react with cardanol to generate a benzophenone ultraviolet absorber. Compared with the traditional synthesis method, the acquisition of the reaction raw materials is relatively simple and the cost is lower.
[0009] Benzophenone ultraviolet absorbers are often added to plastics, coatings, cosmetics and other products. However, due to the presence of alkoxy groups in benzophenone ultraviolet absorbers, such ultraviolet absorbers not only have obvious photodegradation effects and poor weather resistance, but are also prone to yellowing and reduced ultraviolet absorption capacity under long-term exposure to light sources. At the same time, due to the presence of alkoxy groups, the dispersion effect in resin and rubber materials is poor, which makes the use scope of such ultraviolet absorbers small. The technical solution uses cardanol as a raw material, so that the original alkoxy group is replaced by the long carbon chain of cardanol in the final product, and the carbon chain is more stable, so that the benzophenone ultraviolet absorber produced by the technical solution has stronger weather resistance and can still maintain whiteness under long-term light. At the same time, the presence of the long carbon chain makes the benzophenone ultraviolet absorber produced by the technical solution easier to disperse in polyester materials, thereby expanding the scope of use.
[0010] In the present invention, the organic solvent in step S1 is one or a combination of ethylene dichloride, carbon tetrachloride and benzene.
[0011] Through the above technical solution, the selection of a non-polar organic solvent can reduce the influence of the solvent on the reaction and make the reaction more stable.
[0012] In the present invention, the benzoic acid derivative in step S1 includes one or a combination of benzoic acid, 4-methoxybenzoic acid, o-hydroxybenzoic acid, p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, and 2-hydroxy-4-methoxybenzoic acid.
[0013] Through the above technical scheme, in the present technical scheme, by selecting a specific type of benzoic acid derivative, the benzene ring of the finally synthesized benzophenone ultraviolet absorber contains a variety of substituents, thereby improving the physical and chemical properties of the ultraviolet absorber.
[0014] In the present invention, the benzoic acid derivative in step S1 is 2,4-dihydroxybenzoic acid.
[0015] Through the above technical solution, the benzophenone ultraviolet absorber achieves the ultraviolet absorption function by forming an intramolecular hydrogen bond between the carbonyl group and the hydroxyl group after absorbing ultraviolet light. Therefore, the benzoic acid derivative selected is 2,4-dihydroxybenzoic acid, which has more hydroxyl groups and better ultraviolet absorption function.
[0016] In the present invention, the cardanol in step S1 includes one or more combinations of cardanol and cardanol diphenol, and the structure of the cardanol is as follows: The structure of the cashew nut diphenol is shown below:
[0017] Through the above technical scheme, cardanol, as a type of natural phenolic compound from cereals or plants extracted from cashew nut shell liquid (CNSL), conforms to the current general direction of green production. Since cardanol contains a variety of biophenols, this technical scheme 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 dibenzaldehyde ultraviolet absorber, so that the ultraviolet absorber produced by this technical scheme 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 benzoic acid derivatives, thereby improving the purity of the final product.
[0018] In the present invention, the cardanol in step S1 is cardanol.
[0019] Through the above technical solution, since cashew diphenol has two hydroxyl groups on the benzene ring, when it reacts with benzoic acid derivatives, the positioning effect is more obvious and the by-product content is lower.
[0020] In the present invention, the metal catalyst in step S1 is one or a combination of aluminum chloride, ferric chloride and aluminum bromide.
[0021] Through the above technical solution, in this technical solution, the metal catalyst selected has a better catalytic effect.
[0022] In the present invention, the reaction temperature in step S1 is 40-60°C.
[0023] Through the above technical solution, the volatility of the organic solvent is low at 40-60°C.
[0024] In the present invention, the reaction temperature in step S2 is 30-40°C.
[0025] Through the above technical solution, the lower reaction temperature in step S2 can reduce the volatilization of hydrochloric acid.
[0026] 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 from cereals or plants extracted from cashew nut shell liquid (CNSL). As a natural plant extract, the material cost is lower than that of the traditional production method; 2. This technical solution uses cardanol as a raw material, so that the original alkoxy group in the final product is replaced by the long carbon chain of cardanol, and the stability of the carbon chain is relatively strong, so that the dibenzaldehyde ultraviolet absorber produced by this technical solution has strong weather resistance; Generally, the present invention recommends the following steps to synthesize benzophenone ultraviolet absorbers: S1: Add 2,4-dihydroxybenzoic acid, cashew phenol and liquid benzene to a reactor, mix well and then add aluminum chloride, react at 40°C for 4h, add ice water and concentrated hydrochloric acid to the reactor after the reaction to separate the benzene layer from the water layer, wash the benzene layer with sodium hydroxide solution and then distill to remove benzene to obtain an intermediate product B; S2: Dissolve the intermediate product B in dilute hydrochloric acid, add aluminum chloride and cuprous chloride, continue to introduce CO under stirring and heating conditions for 4 hours, adjust the pH to neutral with sodium hydroxide solution after the reaction, and distill to obtain the intermediate product C; S3: reacting the intermediate product C with an acidic potassium permanganate solution to obtain the target product, a benzophenone ultraviolet absorber. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 This is a liquid chromatogram of the finished product of Example 1 of the method for synthesizing a plant extract cardanol-modified benzophenone ultraviolet absorber in the embodiments of the present application.
[0028] Figure 2 This is the nuclear magnetic resonance image of the finished product of Example 1 of the method for synthesizing a plant extract cardanol-modified benzophenone ultraviolet absorber in the embodiments of the present application. DETAILED DESCRIPTION
[0029] The present invention is further described below through specific implementation modes, but the protection scope of the present invention is not limited thereto.
[0030] Preparation Example 1: S1: Add 154g 2,4-dihydroxybenzoic acid (1mol), 380g cashew phenol (1.2mol) and 500ml liquid benzene to a reactor, mix well and then add 20g aluminum chloride, react at 40°C for 4h, add 500ml ice water and 50ml concentrated hydrochloric acid to the reactor after the reaction, separate the benzene layer from the water layer, wash the benzene layer with 1mol / L sodium hydroxide solution and then distill to remove benzene to obtain intermediate product B; S2: Dissolve the intermediate product B in 500 ml of dilute hydrochloric acid, add 20 g of aluminum chloride and 20 g of cuprous chloride, continue to introduce CO under stirring and heating conditions for 4 hours, and after the reaction, use 1 mol / L sodium hydroxide solution to adjust the pH to neutral, and distill to obtain the intermediate product C; S3: react the intermediate product C with 200 ml of acidic potassium permanganate solution, adjust the pH to neutral with 1 mol / L sodium hydroxide solution, and distill to obtain the target product, benzophenone ultraviolet absorber.
[0031] The difference between Preparation Example 2 and Preparation Example 1 is that the raw material selected in step S1 of Preparation Example 2 is cashew nut monophenol.
[0032] The difference between Preparation Example 3-6 and Preparation Example 1 is that the type of benzoic acid derivative selected in step S1 of Preparation Example 3 is different, as shown in the following table: Benzoic acid derivatives Preparation Example 3 benzoic acid Preparation Example 4 Parabens Preparation Example 5 4-Methoxybenzoic acid Preparation Example 6 2-Hydroxy-4-methoxybenzoic acid The modified polyester particles were prepared by mixing the various 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. The adhesive and dispersant do not have ultraviolet absorption function.
[0033] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 is a commercially available dibenzaldehyde type ultraviolet absorber.
[0034] Detection Methods Liquid chromatography was used to perform liquid phase analysis on the products of each preparation example to obtain the purity and yield of each product.
[0035] The modified polyester particles prepared in each embodiment and comparative example were melt-drawn and woven into fabrics for ultraviolet irradiation experiments to obtain the ultraviolet absorption rates of each embodiment and comparative example.
[0036] The modified polyester particles prepared in each embodiment and comparative example were melt-drawn and woven into fabrics for a long-term ultraviolet irradiation experiment to observe the color changes of each embodiment and comparative example.
[0037] The test results are shown in the following table: Product purity (%) Product yield (%) Example 1 99.2 83.5 Example 2 97.5 80.6 Example 3 99.6 81.6 Example 4 99.4 81.2 Example 5 99.5 82.2 Example 6 99.3 81.3 Conclusion: Reference Figure 2 The structure of the benzophenone ultraviolet absorber prepared in this application is: Conclusion: It can be seen from the data of Example 1 and Example 2 in the above table that when synthesizing benzophenone ultraviolet absorbers, the product yield and purity of cashew nut diphenol as the raw material are greater than the product yield and purity of cashew nut monophenol as the raw material. This is due to the positioning effect of the two hydroxyl groups on cashew nut bisphenol, which makes it have a more certain position when it is substituted with a benzoic acid derivative, while there is only one hydroxyl group on the benzene ring of cashew nut monophenol, and the positioning is not obvious, so it is easy to produce more by-products during the reaction. UV transmittance (%) Horizontal return angle (°) Example 1 0.3 178 Example 2 0.7 176 Example 3 8.7 125 Example 4 4.5 152 Example 5 6.8 146 Example 6 1.3 165 Comparative Example 1 15.2 115
[0038] Conclusion: It can be seen from the data of Example 1 and Comparative Example 1 in the above table that the benzophenone ultraviolet absorber produced by the present technical solution has not only lower ultraviolet transmittance but also higher horizontal recovery angle than the commercially available benzophenone ultraviolet absorber, which indicates that the benzophenone ultraviolet absorber produced by the present technical solution has excellent ultraviolet absorption function and meets the requirements on the market.
[0039] Conclusion: It can be seen from the data of Examples 1-6 in the above table that when the benzophenone 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 benzophenone ultraviolet absorbers absorbing ultraviolet rays is that the carbonyl group and the hydroxyl group 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 irradiated with 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.
[0040] Conclusion: Through Example 1 and Examples 3-6 in the above table, the ultraviolet absorption function of the ultraviolet absorber produced by using 2,4-dihydroxybenzoic acid as the raw material in the present technical solution is relatively excellent. This is because there are more hydroxyl groups on 2,4-dihydroxybenzoic acid, which is easier to form intramolecular hydrogen bonds with carbonyl groups, thereby improving the ultraviolet absorption function. 12 hours 24 hours 48 hours Example 1 white white Yellowing Comparative Example 1 white Yellowing Obvious yellowing
[0041] Conclusion: It can be seen from the data of Example 1 and Comparative Example 3 in the above table that the benzophenone ultraviolet absorber produced by the present technical scheme can still maintain white color under long-term ultraviolet irradiation, and does not appear yellow until 48 hours of continuous irradiation, compared with the commercially available benzophenone ultraviolet absorber. The commercially available benzophenone 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 benzophenone ultraviolet absorber produced by the present technical scheme has excellent weather resistance and can be applied to objects that need to be exposed to the sun 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, so that the benzophenone ultraviolet absorber produced by the present technical scheme has stronger weather resistance.
[0042] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.
Claims
1. A method for synthesizing a benzophenone-based ultraviolet absorber modified with plant extract cardanol, characterized in that: The steps include: S1: Add benzoic acid derivatives, cardanol and organic solvent to a reactor, mix well and then add a metal catalyst, react for 3-4 hours under stirring and heating conditions, add ice water and concentrated hydrochloric acid to the reactor after the reaction is completed, separate the organic layer from the aqueous layer, wash the organic layer with sodium hydroxide solution and then distill to remove benzene to obtain intermediate product B: S2: Dissolve the intermediate product B in dilute hydrochloric acid, add aluminum chloride and cuprous chloride, continue to introduce CO under stirring and heating conditions for 3-4 hours, adjust the pH to neutral with sodium hydroxide solution after the reaction, and distill to obtain the intermediate product C S3: reacting the intermediate product C with an acidic potassium permanganate solution to obtain the target product, a benzophenone ultraviolet absorber.
2. The method for synthesizing a plant extract cardanol-modified benzophenone ultraviolet absorber according to claim 1, characterized in that: The organic solvent in step S1 is one or a combination of ethylene dichloride, carbon tetrachloride and benzene.
3. The method for synthesizing a plant extract cardanol-modified benzophenone ultraviolet absorber according to claim 1, characterized in that: The benzoic acid derivative in step S1 includes one or a combination of benzoic acid, 4-methoxybenzoic acid, o-hydroxybenzoic acid, p-hydroxybenzoic acid, 2,4-dihydroxybenzoic acid, and 2-hydroxy-4-methoxybenzoic acid.
4. The method for synthesizing a plant extract cardanol-modified benzophenone ultraviolet absorber according to claim 3, characterized in that: The benzoic acid derivative in step S1 is 2,4-dihydroxybenzoic acid.
5. The method for synthesizing a plant extract cardanol-modified benzophenone ultraviolet absorber according to claim 1, characterized in that: The cardanol in step S1 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).
6. The method for synthesizing a plant extract cardanol-modified benzophenone ultraviolet absorber according to claim 5, characterized in that: The cardanol in step S2 is cardanol.
7. The method for synthesizing a plant extract cardanol-modified benzophenone ultraviolet absorber according to claim 1, characterized in that: The metal catalyst in step S1 is one or a combination of aluminum chloride, ferric chloride and aluminum bromide.
8. The method for synthesizing a plant extract cardanol-modified benzophenone ultraviolet absorber according to claim 1, characterized in that: The reaction temperature in step S1 is 40-60°C.
9. The method for synthesizing a plant extract cardanol-modified benzophenone ultraviolet absorber according to claim 1, characterized in that: The reaction temperature in step S2 is 30-40°C.