Strong-conjugation high-polarity ultraviolet absorbent as well as preparation method and application thereof
By introducing para-ester groups to nylon fibers to form covalent bonds with amino groups and combining them with polar groups, the problem of weak binding force of UV absorbers in nylon fabrics is solved, achieving durable and wavelength-broadened UV protection effects.
Patent Information
- Application Number
- CN202511751492.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-26
- Publication Date
- 2026-03-03
AI Technical Summary
In existing technologies, UV absorbers on nylon fabrics are not very effective, especially after repeated washing, their protective performance decreases significantly, and conventional padding processes are difficult to firmly fix the absorbers onto the fibers.
By introducing para-ester groups to undergo a Michael addition reaction with the amino groups in nylon fibers, stable covalent bonds are formed, which are then combined with UV absorbers. Furthermore, the polar groups enhance intermolecular forces, forming a strongly conjugated, highly polar UV absorber, thereby improving wash resistance and water solubility.
It enhances the bonding force between the UV absorber and nylon fiber, improves the durability and processing applicability of the UV protection effect, broadens the absorption wavelength range, improves the dispersibility in the dyeing bath, and avoids color spot problems.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of textile finishing agent preparation, specifically relating to a strongly conjugated, highly polar ultraviolet absorber, its preparation method, and its application. Background Technology
[0002] Ultraviolet (UV) radiation is a type of electromagnetic radiation, divided into long-wave ultraviolet (320-400nm, UV-A), medium-wave ultraviolet (280-320nm, UV-B), and short-wave ultraviolet (200-280nm, UV-C). UV-C is absorbed by the ozone layer and rarely reaches the ground. UV-B and UV-A can cause skin darkening and sunburn, leading to erythema, blisters, skin diseases (such as dermatitis and xeroderma pigmentosum), and even skin cancer. They can also contribute to cataracts and weaken the immune system.
[0003] Textile fibers themselves have a certain absorption and shielding effect on ultraviolet (UV) radiation. Different types of fibers have varying abilities to absorb or transmit UV radiation, primarily influenced by factors such as fiber material and fabric structure. Among widely used fiber raw materials, polyester contains benzene rings and thus has a high UV absorption capacity; while nylon has a poor UV absorption capacity, especially in nylon skin garments (380T) designed for lightweight and breathable summer wear. While its lightweight fabric is popular with consumers, the larger gaps between nylon yarns further exacerbate UV transmittance. Currently, conventional finishing processes such as padding are often used to impart UV protection to fabrics; however, existing technologies face significant limitations in improving UV absorption in nylon materials. Although organic UV absorbers (such as benzophenone and benzotriazoles) can absorb UV light through their molecular structure and dissipate energy as heat, their binding force on nylon fibers is weak. In conventional padding processes, absorbers struggle to effectively penetrate and firmly adhere, leading to a sharp decline in protective performance after repeated washing. Summary of the Invention
[0004] To address the problem that existing technologies do not provide effective UV absorbers for nylon fabrics, this application provides a strongly conjugated, highly polar UV absorber, its preparation method, and its application.
[0005] This application introduces para-esters into the UV absorber. The vinyl sulfone group of the para-ester can undergo a Michael addition reaction with the amino group (-NH2) in nylon to form a stable covalent bond, thereby firmly binding the UV absorber to the nylon fiber and enhancing wash resistance. Furthermore, these polar groups stabilize the excited state by enhancing intermolecular forces (such as hydrogen bonds and ionic bonds), promoting the conversion of UV light energy into heat energy and improving photostability. Simultaneously, the polar groups significantly enhance water solubility, ensuring uniform dispersion in the dyeing bath, avoiding color spot problems caused by aggregation, and improving the interaction with nylon fibers, thereby improving the durability of the UV protection effect and processing suitability.
[0006] Furthermore, when the UV-absorbing monomer (BP-2) reacts with cyanuric chloride and para-ester, in addition to generating an extended conjugated system of triazine derivatives with an asymmetric structure (BP-2-triazine-para-ester), a hyperconjugated system with a stronger symmetric structure (para-ester-triazine-BP-2-triazine-para-ester) can also be generated. Moreover, the unsubstituted phenolic hydroxyl groups can form strong intramolecular hydrogen bonds with adjacent carbonyl groups (C=O), which can stabilize the excited state, promote the dissipation of light energy in the form of harmless heat energy, and broaden the absorption range to a longer wavelength, i.e., a red shift occurs, thus significantly reducing UVA.
[0007] One of the technical solutions of this invention is to provide a strongly conjugated, highly polar ultraviolet absorber, characterized in that it is obtained by polymerization of an ultraviolet absorber monomer, cyanuric chloride, and a water-soluble monomer, wherein the ultraviolet absorber monomer is... The water-soluble monomer is a para-ester.
[0008] The second technical solution of the present invention is to provide a method for preparing the above-mentioned strongly conjugated high polarity ultraviolet absorber. The method involves dissolving cyanuric chloride in methyl ethyl ketone, adding the ultraviolet absorber monomer under ice-water bath conditions at 0-5°C, and carrying out a substitution reaction. Subsequently, the water-soluble monomer is added dropwise to the reaction system, and the substitution reaction is carried out at 40°C for 5 hours. Finally, the solvent is removed, and the strongly conjugated high polarity ultraviolet absorber is obtained after purification and filtration.
[0009] Furthermore, the molar ratio of the cyanuric chloride, the ultraviolet absorber monomer, and the water-soluble monomer is 1:1:1.
[0010] Furthermore, adding an aqueous solution of NaOH allows the substitution reaction to proceed in the forward direction.
[0011] Furthermore, the solvent removal method is rotary evaporation under reduced pressure.
[0012] The third technical solution of this invention lies in providing the application of the aforementioned highly conjugated, highly polar UV absorber in UV-resistant finishing of fabrics. The fabric is a nylon fabric. In application, the amount of the highly conjugated, highly polar UV absorber is 3-6% owf.
[0013] The advantages of this invention are: (1) The structure of the triazine derivative of the hyperconjugated system (para ester-triazine-BP-2-triazine-para ester) was designed, which extended the conjugated system, enabled intramolecular charge transfer, broadened the ultraviolet absorption spectrum, and formed an ultraviolet absorber with strong absorption of both UVA and UVB.
[0014] (2) The highly conjugated, highly polar UV absorber has a moderate molecular weight, close to that of the dye, which is beneficial for use in dyeing bath processes. It also has good water solubility, allowing for high dispersion and preventing aggregation, thus enabling uniform fabric treatment. The synthesized product incorporates highly polar groups, which stabilize the excited state by enhancing intermolecular forces (such as hydrogen and ionic bonds), promoting the conversion of UV light energy into heat energy, and improving photostability. Simultaneously, the polar groups significantly enhance water solubility, ensuring uniform dispersion in the dyeing bath, avoiding color spot problems caused by aggregation, and improving the interaction with nylon fibers, thereby enhancing the durability of the UV protection effect and its processing applicability. Detailed Implementation
[0015] The following examples are provided to further illustrate the present invention and are intended to explain the invention, not to limit its scope. Unless otherwise specified, all figures are expressed in parts by weight and weight percentages.
[0016] Unless otherwise specified, the raw materials used in this invention are all conventional commercially available products; unless otherwise specified, the methods used in this invention are all conventional methods in the field.
[0017] The UV resistance test in this application is performed in accordance with GB / T 18830-2009.
[0018] The embodiments of the present invention will be further described below with reference to several examples.
[0019] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.
[0020] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.
[0021] Example 1: In a 250 mL round-bottom flask, 0.04 mol of cyanuric chloride was dissolved in 80 mL of butanone. 0.04 mol of UV absorber monomer BP-2 was added under ice-water bath conditions at 0-5 °C, with 0.04 mol of dissolved NaOH solution added during the process. After the reactants were fully reacted as monitored by TLC, 0.04 mol of para-ester was dissolved in water and slowly added dropwise to the reaction system. The temperature was gradually increased to 40 °C, with 0.04 mol of dissolved NaOH solution added dropwise during the process, allowing the substitution reaction to proceed fully in the forward direction for 5 hours. Finally, the solvent in the product was removed by rotary evaporation under reduced pressure, and after purification and filtration, a 25% emulsion was prepared as the product. The product was then used to finish 20D nylon twill at ratios of 3% owf and 6% owf, and its UV absorption effect was tested.
[0022] The original BP-2 molecule contains multiple phenolic hydroxyl groups and has a wider UV absorption range and a higher molar absorptivity. When it reacts with cyanuric chloride and para-ester, in addition to forming an extended conjugated system of triazine derivatives with an asymmetric structure (BP-2-triazine-para-ester), it is also possible to form a hyperconjugated system with a stronger symmetric structure (para-ester-triazine-BP-2-triazine-para-ester). Moreover, the unsubstituted phenolic hydroxyl groups can form strong intramolecular hydrogen bonds with adjacent carbonyl groups (C=O), which can stabilize the excited state, promote the dissipation of light energy as harmless heat, and broaden the absorption range to a longer wavelength, i.e., a redshift occurs, thus resulting in the most significant UVA reduction effect.
[0023] The chemical formula of BP-2 is as follows: .
[0024] The chemical formula of the para-ester is as follows: .
[0025] The ethylene sulfone group of the para-ester can undergo a Michael addition reaction with the amino group (-NH2) in nylon to form a stable covalent bond, thereby firmly binding the UV absorber to the nylon fiber and enhancing its wash resistance.
[0026] Comparative Example 1 0.04 mol of cyanuric chloride was dissolved in 80 mL of butanone in a 250 mL round-bottom flask. 0.040 mol of UV absorber monomer BP-2 was added under ice-water bath conditions at 0-5°C, along with 0.04 mol of dissolved NaOH solution. The reaction was allowed to proceed for 5 hours. Finally, the solvent was removed from the product by rotary evaporation under reduced pressure. After purification and filtration, a 30% emulsion was prepared, which was the product. The product was then used to finish 20D nylon twill at ratios of 3% owf and 6% owf, and its UV absorption effect was tested. Because no para-ester was added during product preparation, it is not water-soluble and cannot be loaded onto nylon fabrics.
[0027] Comparative Example 2 The only difference from Example 1 is that the para-ester is replaced with sodium p-aminobenzenesulfonate. Specifically, 0.04 mol of cyanuric chloride is dissolved in 80 mL of butanone in a 250 mL round-bottom flask. 0.04 mol of UV absorber monomer BP-4 is added under ice-water bath conditions at 0-5°C, along with a solution of 0.04 mol dissolved in NaOH. After the reaction is complete as monitored by TLC, 0.04 mol of sodium p-aminobenzenesulfonate is dissolved in water and slowly added dropwise to the reaction system. The temperature is gradually increased to 40°C, with the same 0.04 mol solution of NaOH added dropwise to allow the substitution reaction to proceed fully in the forward direction for 5 hours. Finally, the solvent in the product is removed by rotary evaporation under reduced pressure, and after purification and filtration, a 25% emulsion is prepared, which is the product. The product is used to finish 20D nylon twill at ratios of 3% owf and 6% owf, and its UV absorption effect is tested.
[0028] Comparative Example 3 The only difference from Example 2 is that the para-ester is replaced with sodium p-aminobenzenesulfonate. Specifically, 0.04 mol of cyanuric chloride is dissolved in 80 mL of butanone in a 250 mL round-bottom flask. 0.04 mol of UV absorber monomer BP-1 is added under ice-water bath conditions at 0-5°C, along with a solution of 0.04 mol dissolved in NaOH. After the reaction is complete as monitored by TLC, 0.04 mol of sodium p-aminobenzenesulfonate is dissolved in water and slowly added dropwise to the reaction system. The temperature is gradually increased to 40°C, with the same 0.04 mol solution of NaOH added dropwise to allow the substitution reaction to proceed fully in the forward direction for 5 hours. Finally, the solvent in the product is removed by rotary evaporation under reduced pressure, and after purification and filtration, a 30% emulsion is prepared, which is the product. The product is then used to finish 20D nylon twill at ratios of 3% owf and 6% owf, and its UV absorption effect is tested.
[0029] Comparative Example 4 The only difference from Example 3 is that the para-ester is replaced with sodium p-aminobenzenesulfonate. Specifically, 0.04 mol of cyanuric chloride is dissolved in 80 mL of butanone in a 250 mL round-bottom flask. 0.04 mol of UV absorber monomer BP-2 is added under ice-water bath conditions at 0-5°C, and 0.04 mol of dissolved NaOH solution is added during the process. After the raw materials have reacted completely under TLC monitoring, 0.04 mol of sodium p-aminobenzenesulfonate dissolved in water is slowly added dropwise to the reaction system. The temperature is gradually increased to 40°C, and 0.04 mol of dissolved NaOH solution is added dropwise during this process to ensure the substitution reaction proceeds fully in the forward direction for 5 hours. Finally, the solvent in the product is removed by rotary evaporation under reduced pressure, and after purification and filtration, a 25% emulsion is prepared, which is the product. The product is used to finish 20D nylon twill at ratios of 3% owf and 6% owf, and its UV absorption effect is tested.
[0030] Comparative Example 5 In a 250 mL round-bottom flask, 0.04 mol of cyanuric chloride was dissolved in 80 mL of butanone. Under an ice-water bath at 0-5 °C, 0.04 mol of UV absorber monomer BP-4 was added, along with a solution of 0.04 mol of dissolved NaOH. After the reaction was complete as monitored by TLC, 0.04 mol of the para-ester was dissolved in water and slowly added dropwise to the reaction system. The temperature was gradually increased to 40 °C, with the same 0.04 mol of dissolved NaOH added dropwise to allow the substitution reaction to proceed fully in the forward direction for 5 hours. Finally, the solvent was removed from the product by rotary evaporation under reduced pressure, and the product was purified, filtered, and prepared into a 25% emulsion. The product was then used to finish 20D nylon twill at ratios of 3% owf and 6% owf, and its UV absorption effect was tested.
[0031] The chemical formula of BP-4 is as follows: .
[0032] Comparative Example 6 In a 250 mL round-bottom flask, 0.04 mol of cyanuric chloride was dissolved in 80 mL of butanone. Under an ice-water bath at 0-5 °C, 0.04 mol of UV absorber monomer BP-1 was added, along with a solution of 0.04 mol of dissolved NaOH. After the reaction was complete as monitored by TLC, 0.04 mol of the para-ester was dissolved in water and slowly added dropwise to the reaction system. The temperature was gradually increased to 40 °C, with the same 0.04 mol of dissolved NaOH added dropwise to allow the substitution reaction to proceed fully in the forward direction for 5 hours. Finally, the solvent was removed from the product by rotary evaporation under reduced pressure, and the product was purified, filtered, and prepared into a 30% emulsion. The product was then used to finish 20D nylon twill at ratios of 3% owf and 6% owf, and its UV absorption effect was tested.
[0033] The chemical formula of BP-1 is as follows: .
[0034] Table 1. Application effects of the examples and comparative examples on 20D nylon twill. Table 2. Application effects of the examples on 20D nylon twill. Note: (1) Water washing should follow the national standard 4N procedure, add ECE standard detergent, and do not add detergent for the last wash; (2) UV resistance test shall be performed in accordance with GB / T 18830-2009. Sodium p-aminobenzenesulfonate contains sulfonic acid groups, which are highly water-soluble and polar. Simultaneously, the sulfonic acid groups bind to the amino or amide groups in nylon through ionic interactions or hydrogen bonds, enhancing water solubility and dispersibility. However, due to the lack of active groups (such as vinyl sulfone) in its molecule that can form covalent bonds with nylon fibers, it mainly relies on hydrogen bonds and ionic interactions for adsorption onto nylon, resulting in a significant decrease in its wash resistance.
[0035] The above embodiments describe in detail the structure, features, and effects of the present invention. The above description is only a preferred embodiment of the present invention. Any changes made in accordance with the concept of the present invention, or equivalent embodiments modified to have equivalent changes, shall still fall within the scope of protection of the present invention if they do not exceed the scope covered by the specification.
Claims
1. A strongly conjugated, highly polar ultraviolet absorber, characterized in that, It is obtained by polymerization of ultraviolet absorber monomer, cyanuric chloride, and water-soluble monomer, wherein the ultraviolet absorber monomer is... The water-soluble monomer is a para-ester.
2. A method for preparing a strongly conjugated, highly polar ultraviolet absorber as described in claim 1, characterized in that, Cyanuric chloride was dissolved in methyl ethyl ketone (MEK), and a UV absorber monomer was added under ice-water bath conditions at 0-5°C to carry out a substitution reaction. Subsequently, a water-soluble monomer was added dropwise to the reaction system, and the substitution reaction was carried out at 40°C for 5 hours. Finally, the solvent was removed, and the product was purified and filtered to obtain a strongly conjugated, highly polar UV absorber.
3. The method according to claim 2, characterized in that, The molar ratio of the cyanuric chloride, the ultraviolet absorber monomer, and the water-soluble monomer is 1:1:
1.
4. The method according to claim 2, characterized in that, Adding an aqueous solution of NaOH allows the substitution reaction to proceed in the forward direction.
5. The method according to claim 2, characterized in that, The solvent removal method is rotary evaporation under reduced pressure.
6. The application of a highly conjugated, highly polar UV absorber as described in claim 1 in UV-resistant finishing of fabrics.
7. The application according to claim 6, characterized in that, The fabric is a nylon fabric.
8. The application according to claim 6, characterized in that, The dosage of a strongly conjugated, highly polar UV absorber is 3-6% owf.