Ultraviolet absorption stabilizer and application thereof in environment-friendly high-strength PU synthetic leather

Abstract

The application discloses an ultraviolet absorption stabilizer and application thereof in environment-friendly high-strength PU synthetic leather, and relates to the technical field of ultraviolet absorption stabilizers.The structure of the ultraviolet absorption stabilizer is as follows: The application has the advantages that the new ultraviolet absorption stabilizer is added into the environment-friendly high-strength PU synthetic leather, can effectively absorb ultraviolet rays and convert the ultraviolet rays into harmless heat energy, and can significantly enhance the weather resistance of the synthetic leather and prolong the service life of the synthetic leather by combining the synergistic effect of the nano filler and the bio-based polyol.

Description

Technical Field

[0001] This invention relates to the field of ultraviolet absorption stabilizer technology, specifically to an ultraviolet absorption stabilizer and its application in environmentally friendly high-strength PU synthetic leather. Background Technology

[0002] In the current market, PU synthetic leather has experienced rapid growth in terms of product quality, variety, and output. Its performance is becoming increasingly similar to that of natural leather, and in some aspects, it even surpasses that of natural leather. As a new type of material widely used in clothing, footwear, furniture, and other fields, PU synthetic leather has achieved remarkable success in its development.

[0003] However, traditional PU synthetic leather faces numerous problems in its production and use. On one hand, its production often uses organic solvents such as toluene and xylene. These solvents are highly volatile, causing not only environmental pollution but also harming human health, such as irritating the respiratory tract and causing dizziness. Long-term exposure may even induce more serious diseases. On the other hand, the mechanical properties of traditional PU synthetic leather need improvement. For example, it performs poorly in tensile strength, abrasion resistance, and weather resistance, making it difficult to meet the demands of high-intensity applications and limiting its further expansion in some high-end application areas. Furthermore, the production of traditional PU synthetic leather also suffers from low resource utilization efficiency, with frequent waste of raw materials. This increases production costs to some extent and contradicts the current advocacy of green and sustainable development.

[0004] As consumers pay increasing attention to environmental protection and health, the market demand for environmentally friendly, high-performance PU synthetic leather is becoming more and more urgent. The shortcomings of traditional PU synthetic leather are becoming more and more prominent. The industry urgently needs to break through existing bottlenecks through technological innovation and develop environmentally friendly, high-strength PU synthetic leather products that meet the requirements of the new era, so as to adapt to market changes and meet people's pursuit of a high-quality life. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of traditional PU synthetic leather, such as insufficient mechanical properties and weather resistance, by providing a UV-absorbing stabilizer and its application in environmentally friendly high-strength PU synthetic leather. This invention aims to develop a PU synthetic leather that reduces environmental burden while improving mechanical strength and weather resistance through environmentally friendly materials and technological innovation.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: an ultraviolet absorption stabilizer, wherein the ultraviolet absorption stabilizer is a compound represented by Formula 1:

[0007] Formula 1: ;

[0008] In Formula 1, R1 is a substituent, specifically selected from any one of alkyl, alkoxy, aryl, and cyano groups with 1-5 carbon atoms.

[0009] Furthermore, the alkyl group having 1-5 carbon atoms is selected from: methyl;

[0010] The alkoxy group with 1-5 carbon atoms is selected from: methoxy group.

[0011] Furthermore, the aryl group with 6-10 carbon atoms is selected from phenyl.

[0012] Furthermore, the ultraviolet absorption stabilizer is any one of the compounds shown in the following structures:

[0013] ;

[0014] .

[0015] Application of a UV absorption stabilizer in environmentally friendly high-strength PU synthetic leather.

[0016] An environmentally friendly, high-strength PU synthetic leather includes a base fabric layer and a PU resin layer coated on the base fabric layer;

[0017] The base fabric layer is composed of woven fabric, which includes either polyester fabric or acrylic fabric, and has a thickness of 0.7-1.0 mm.

[0018] The PU resin layer is made of the following components in the indicated mass ratios: waterborne polyurethane resin: 40-60 parts, bio-based polyol: 10-25 parts, environmentally friendly plasticizer: 2-6 parts, nano-reinforcing filler: 3-8 parts, environmentally friendly crosslinking agent: 1-5 parts, ultraviolet absorption stabilizer: 0.5-1 part, defoamer: 0.2-0.5 parts, and deionized water: 5-15 parts;

[0019] The ultraviolet absorption stabilizer is the ultraviolet absorption stabilizer described above.

[0020] Furthermore, the bio-based polyol is at least one of methyl ricinoleate and corn starch-based polyol;

[0021] The environmentally friendly plasticizer is at least one of triethyl acetylglucosyl citrate and trioctyl acetylglucosyl citrate.

[0022] Furthermore, the nano-reinforcing filler is modified nano-silica with a particle size of 20-50 nm;

[0023] The modified nano-silica preparation method is as follows: nano-silica is dispersed in an ethanol-water mixed solvent, ultrasonically treated to form a uniform suspension, then silane coupling agent KH-550 is added, the pH is adjusted to 4-5 with acetic acid, and the reaction is mechanically stirred at 60-70℃ for 2-4 hours. The solid is separated by centrifugation, unreacted substances are removed by washing with ethanol, and the modified nano-silica is obtained by vacuum drying at 60℃.

[0024] Furthermore, the environmentally friendly crosslinking agent is at least one of epichlorohydrin and formaldehyde-free isocyanate crosslinking agents.

[0025] Furthermore, the defoamer is at least one of dimethylsiloxane and polyoxypropylene.

[0026] A method for preparing environmentally friendly high-strength PU synthetic leather, characterized by comprising the following steps:

[0027] a. Add the waterborne polyurethane resin, bio-based polyol, environmentally friendly plasticizer, nano-reinforced filler, and deionized water into a disperser, and stir and disperse at 800-1500 rpm for 20-40 minutes at 50-70℃ to form a mixture;

[0028] b. Add the UV absorber stabilizer, defoamer, and environmentally friendly crosslinking agent to the mixture, maintain the temperature at 50-70℃, and stir at 600-1000 rpm for 5-15 minutes to disperse and form a PU resin slurry;

[0029] c. Coat the PU resin slurry onto the surface of the base fabric layer with a coating thickness of 0.2-0.5 mm;

[0030] d. Pre-bake the coated substrate at 70-90℃ for 3-5 minutes, then cure at 120-140℃ for 5-10 minutes;

[0031] e. After the cured base fabric is cooled, surface embossed or sanded, an environmentally friendly high-strength PU synthetic leather is obtained.

[0032] Furthermore, in step c, the coating process is performed using a doctor blade or roller coating.

[0033] Application of an environmentally friendly, high-strength PU synthetic leather in clothing, furniture upholstery materials and other fields.

[0034] The UV-absorbing stabilizer described in this invention can absorb ultraviolet radiation and convert it into harmless heat energy, preventing UV-induced material degradation. The specific mechanism is as follows:

[0035] ① Absorbing UV radiation: UV absorber molecules contain specific chromophores that can effectively absorb UV wavelengths of 280-400nm, forming a "sunscreen" effect and creating a protective layer in the polymer.

[0036] ② Energy Conversion: After absorbing UV photons, the molecules transition from the ground state to the excited state. Subsequently, the energy is released as heat through internal conversion, avoiding photochemical reactions, improving the weather resistance of synthetic leather, and reducing the decrease in strength and color changes caused by photo-oxidation.

[0037] ③ Free radical quenching: UV absorber stabilizers can also quench free radicals, preventing chain reactions from damaging the molecular structure of PU resin. They work synergistically with environmentally friendly crosslinking agents to ensure the stability of the material during outdoor use.

[0038] This invention achieves a synergistic effect through component innovation and preparation process. Water-based environmentally friendly materials reduce pollution, nanofillers and bio-based components enhance mechanical strength, and specific UV-absorbing stabilizers improve weather resistance, realizing a three-in-one mechanism of "environmental protection-strength-durability." The synergistic mechanism for solving environmental pollution problems: water-based polyurethane resin and deionized water serve as the main resin and solvent, completely replacing organic solvents. The water-based system is non-toxic and low-volatility, eliminating VOC emissions at the source. The synergistic use of deionized water ensures an environmentally friendly process without irritating gases. Environmentally friendly plasticizers and crosslinking agents are used; the plasticizer is a citrate ester, non-toxic and biodegradable; the crosslinking agent is formaldehyde-free, preventing formaldehyde release. Together with the water-based resin, they ensure the resin layer's flexibility and a pollution-free curing process. Water-based resin + water solvent + recycled base fabric form a green foundation, with environmentally friendly plasticizers and crosslinking agents acting as auxiliary agents to jointly eliminate solvent pollution and resource waste.

[0039] A synergistic mechanism to address insufficient mechanical properties: The modification method of nano-reinforced fillers improves dispersibility and interfacial bonding. Nanoparticles, acting as a "reinforcing skeleton," increase hardness, wear resistance, and tensile strength after embedding in the resin layer. Bio-based polyol molecular chains, containing long-chain fatty acids, provide inherent toughness and flexibility. Synergistically with the nano-fillers, the bio-polyols act as "flexible bridges," filling the gaps between nanoparticles and enhancing impact resistance and fatigue durability. Waterborne polyurethane resin serves as the matrix, providing basic strength; plasticizers improve resin plasticity and processability, preventing brittleness. The three work synergistically to ensure high strength and wear resistance, meeting the needs of high-strength applications. Nanofillers provide rigid support, bio-polyols contribute flexibility, and waterborne resins and plasticizers optimize the overall structure. The preparation method ensures uniform dispersion of the filler, avoiding aggregation defects.

[0040] Synergistic mechanism to address insufficient weather resistance: UV-absorbing stabilizers work synergistically with waterborne polyurethane resin and nanofillers. The resin provides a uniformly dispersed matrix, while nano-silica reflects and scatters UV rays, enhancing the stabilizer's effect. Bio-polyols contain natural antioxidant groups, reducing oxidative degradation. Defoamers, as process aids, eliminate bubble defects, ensuring resin layer density and reducing UV penetration pathways. The UV-absorbing stabilizer forms the core protective layer, nanofillers and resin provide a physical barrier, and bio-polyols supplement antioxidant protection. The preparation method ensures uniform mixing of the stabilizer, and the curing conditions promote cross-linking, forming a stable, weather-resistant network.

[0041] Compared with the prior art, the beneficial effects of the present invention are:

[0042] 1. Significantly improved environmental friendliness: This invention uses water-based polyurethane resin and deionized water to replace organic solvents, reducing the emission of volatile organic compounds (VOCs) at the source.

[0043] 2. Significantly enhanced mechanical properties: This invention, by adding modified nano-silica as a reinforcing filler and bio-based polyols, synergistically improves the material's hardness, wear resistance, and impact resistance, making it perform better in mechanical properties such as tensile load and tear load, thus broadening its application fields.

[0044] 3. Significantly improved weather resistance: This invention innovatively incorporates a UV absorption stabilizer, which can effectively absorb ultraviolet rays and convert them into harmless heat energy. At the same time, combined with the synergistic effect of nanofillers and bio-based polyols, it significantly enhances the weather resistance of synthetic leather and extends its service life. Attached Figure Description

[0045] Figure 1 This is the NMR spectrum of the ultraviolet absorption stabilizer 1 described in this invention. Detailed Implementation

[0046] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described application examples are only a part of the application examples of the present invention, and not all of them. Based on the application examples of the present invention, all other application examples obtained by those skilled in the art without inventive effort are within the scope of protection of the present invention.

[0047] Example 1

[0048] Synthesis of UV absorber stabilizer 1:

[0049] ;

[0050] Step 1: Under a nitrogen atmosphere, add 15.00 g of raw material 1, 8.52 g of raw material 2, 6.87 g of triethylamine and 200 ml of dimethyl sulfoxide to the reaction system, heat to 85 °C and react for 16 h; after cooling, adjust the pH of the system to neutral with 0.1 mol / L HCl, wash the organic phase five times with water, and then wash twice with saturated NaCl solution; finally, dry the combined organic phase with anhydrous Na2SO4, evaporate to dryness, purify by silica gel column chromatography, using a mixed solution of petroleum ether and ethyl acetate as the eluent, evaporate to dryness, and obtain 14.38 g of intermediate 1.

[0051] Step 2: Under a nitrogen atmosphere, add 14.38 g of intermediate 1, 6.12 g of starting material 3, 9.75 g of anhydrous potassium carbonate, 0.81 g of tetra(triphenylphosphine)palladium and 300 g of toluene to the reaction system. Heat to 95 °C and reflux for 10 hours. Turn off the heating, cool to room temperature, allow to stand and separate the liquids. Extract the aqueous phase twice with ethyl acetate, combine the organic phases, dry the organic phase with anhydrous magnesium sulfate, filter, evaporate to dryness, and perform silica gel column chromatography with a mixture of petroleum ether and ethyl acetate as eluent. Evaporate to dryness to obtain 12.52 g of UV absorber stabilizer 1.

[0052] Structural assessment:

[0053] Mass spectrometry of intermediate 1 (M / Z MS+1): 612.

[0054] Mass spectrometry of UV absorber stabilizer 1 (M / Z MS+1: 747).

[0055] NMR of UV absorber 1 1 H NMR (Chloroform-d) δ 8.31-8.19(m,2H),7.96-7.73(m,7H),7.64-7.36(m,6H),7.36-7.18(m,7H),7.1 2-6.98(m,2H),2.41(t,3H),1.74(s,2H),1.61(s,6H),1.33(s,6H),0.78(s,9H).

[0056] Examples 2-4

[0057] In Examples 2-4, UV absorption stabilizers 2-4 were synthesized sequentially, following the same synthesis method as in Example 1, except that raw material 3 was replaced, while the rest remained the same as in Example 1. The specific structures of raw material 3, UV absorption stabilizers 2-4, and M / Z MS+1 data are shown in Table 1.

[0058] Table 1. Structures of raw material 3, UV absorber stabilizer 2-UV absorber stabilizer 4, and M / Z MS+1 data involved in Examples 2-4.

[0059]

[0060] Application Example 1

[0061] Preparation of an environmentally friendly high-strength PU synthetic leather:

[0062] 1. Raw material mass ratio:

[0063] Waterborne polyurethane resin: 50 parts, purchased from Foshan Weng Kai'er Trading Co., Ltd., product number: A-539;

[0064] Bio-based polyols: 15 parts, selected from methyl ricinoleate, purchased from Shandong Xiya Chemical Co., Ltd., CAS: 141-24-2;

[0065] Environmentally friendly plasticizer: 4 parts, selected from triethyl acetylglucosyl citrate, purchased from: Shanghai Maclean Biochemical Technology Co., Ltd., CAS: 77-89-4;

[0066] Nano-reinforced filler: 5 parts, selected from modified nano-silica;

[0067] Environmentally friendly crosslinking agent: 3 parts, selected from epichlorohydrin, purchased from: Shanghai Aladdin Biochemical Technology Co., Ltd., CAS: 106-89-8;

[0068] UV absorption stabilizer: 0.7 parts, selected from UV absorption stabilizer 1 prepared in Example 1;

[0069] Defoamer: 0.3 parts, selected from dimethylsiloxane, purchased from: Hubei Nuona Technology Co., Ltd., CAS: 31692-79-2;

[0070] Deionized water: 10 parts.

[0071] 2. Preparation method:

[0072] The modified nano-silica is prepared as follows: 5 parts of nano-silica are dispersed in an ethanol-water mixed solvent (volume ratio 4:1) and ultrasonically treated to form a uniform suspension. Then, 5 parts of silane coupling agent KH-550 are added, the pH is adjusted to 4 with acetic acid, and the mixture is mechanically stirred at 70°C for 3 hours. The solid is separated by centrifugation, unreacted substances are removed by washing with ethanol, and the modified nano-silica is obtained by vacuum drying at 60°C.

[0073] Preparation of an environmentally friendly high-strength PU synthetic leather:

[0074] a. Add the waterborne polyurethane resin, bio-based polyol, environmentally friendly plasticizer, nano-reinforced filler, and deionized water to a disperser, and stir and disperse at 1200 rpm for 30 minutes at 60°C to form a mixture;

[0075] b. Add the UV absorber stabilizer, defoamer, and environmentally friendly crosslinking agent to the mixture, maintain the temperature at 60°C, and stir at 800 rpm for 10 minutes to disperse and form a PU resin slurry;

[0076] c. The PU resin slurry is coated onto the surface of the base fabric layer using a doctor blade process, with a coating thickness of 0.3 mm;

[0077] d. Dry the coated substrate in an oven at 85°C for 5 minutes, then cure it at 130°C for 8 minutes;

[0078] e. After the cured base fabric is cooled, surface embossed or sanded, an environmentally friendly high-strength PU synthetic leather is obtained.

[0079] Application Examples 2-4

[0080] The preparation of an environmentally friendly high-strength PU synthetic leather is carried out by referring to the preparation method of Application Example 1, except that the ultraviolet absorption stabilizer is replaced sequentially with ultraviolet absorption stabilizer 2-ultraviolet absorption stabilizer 4 synthesized in Examples 2-4, and the rest is the same as in Application Example 1.

[0081] Comparative Application Example 1

[0082] The preparation of an environmentally friendly high-strength PU synthetic leather is based on the preparation method of Application Example 1, except that the ultraviolet absorption stabilizer is replaced with ultraviolet absorber UV928 (CAS: 73936-91-1), and the rest is the same as in Application Example 1.

[0083] Comparative Application Example 2

[0084] The preparation of an environmentally friendly high-strength PU synthetic leather is based on the preparation method of Application Example 1, except that the ultraviolet absorption stabilizer is replaced with ultraviolet absorber UV531 (CAS: 1843-05-6), and the rest is the same as in Application Example 1.

[0085] Comparative Application Example 3

[0086] The preparation of an environmentally friendly high-strength PU synthetic leather is the same as in Application Example 1, except that the ultraviolet absorption stabilizer is not added.

[0087] Comparative Application Example 4

[0088] The preparation of an environmentally friendly high-strength PU synthetic leather is the same as in Application Example 1, except that no environmentally friendly plasticizer is added.

[0089] Comparative Application Example 5

[0090] The preparation of an environmentally friendly high-strength PU synthetic leather is the same as in Application Example 1, except that no nano-reinforcing filler is added.

[0091] Comparative Application Example 6

[0092] The preparation of an environmentally friendly high-strength PU synthetic leather is the same as in Application Example 1, except that no environmentally friendly crosslinking agent is added.

[0093] Performance testing:

[0094] 1. According to the standard QB / T 5143-2017, an environmentally friendly high-strength PU synthetic leather prepared in the corresponding use case and comparative application case was tested for tear load, tensile load and abrasion resistance. The tear load specimen was 150mm long × 30mm wide, the tensile load specimen was 200mm long × 30mm wide, and the abrasion resistance test condition was dry friction. The results are shown in Table 2.

[0095] 2. Weather Resistance Test: An environmentally friendly high-strength PU synthetic leather prepared in the application example and the comparative application example was exposed to a xenon lamp aging test chamber for 4800 hours to simulate natural aging conditions such as light exposure, condensation, and humidity changes. The exposure conditions were: radiation intensity 0.35 W / m². 2 (340nm wavelength) Temperature cycling was performed at 60℃ (illumination stage) and 20℃ (condensation stage), and humidity cycling was performed at 50%±5% (illumination stage) and 95%±5% (condensation stage). The illumination stage lasted for 8 hours, and the condensation stage (simulated rain) lasted for 4 hours. After the exposure, tear load tests were performed according to the standard QB / T 5143-2017, and the results are shown in Table 2.

[0096] Table 2. Application Examples and Comparisons: Performance test data of an environmentally friendly high-strength PU synthetic leather prepared in the application examples.

[0097]

[0098] Compared to the comparative application examples, the PU synthetic leather prepared by the application examples of this invention significantly outperforms all the comparative application examples in overall performance. The application examples exhibit superior performance in all test indicators: the tear load and tensile load of the application examples are stronger overall, while the comparative application examples show varying degrees of decrease; in terms of abrasion resistance, the abrasion resistance grade of the application examples is lower, proving that its abrasion resistance performance is better, while the abrasion resistance of the comparative application examples shows varying degrees of decrease.

[0099] In extreme long-term weather resistance tests, the tear load of the applied example remained relatively stable after aging without a significant decrease, while the control examples generally showed a decline in performance. This indicates that the UV absorption stabilizer described in this invention can effectively enhance weather resistance, fully highlighting the advantages of the formulation and process of this invention in improving the overall performance of PU synthetic leather.

[0100] Although examples of application of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these examples without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A UV absorption stabilizer, characterized in that, The ultraviolet absorption stabilizer is a compound represented by Formula 1: Formula 1: ; In Formula 1, R1 is a substituent, specifically selected from any one of alkyl, alkoxy, aryl, and cyano groups having 1-5 carbon atoms.

2. The ultraviolet absorption stabilizer according to claim 1, characterized in that, The alkyl group having 1-5 carbon atoms is selected from: methyl; The alkoxy group having 1-5 carbon atoms is selected from: methoxy group.

3. The ultraviolet absorption stabilizer according to claim 1, characterized in that, The aryl group with 6-10 carbon atoms is selected from phenyl.

4. The ultraviolet absorption stabilizer according to claim 1, characterized in that, The ultraviolet absorption stabilizer is any one of the compounds shown in the following structures: ； 。 5. The application of the UV absorption stabilizer as described in any one of claims 1-4 in environmentally friendly high-strength PU synthetic leather.

6. An environmentally friendly, high-strength PU synthetic leather, characterized in that, Includes a base fabric layer and a PU resin layer coated on the base fabric layer; The base fabric layer is composed of woven fabric, which includes either polyester fabric or acrylic fabric, and has a thickness of 0.7-1.0 mm. The PU resin layer is made of the following components in the indicated mass ratios: waterborne polyurethane resin: 40-60 parts, bio-based polyol: 10-25 parts, environmentally friendly plasticizer: 2-6 parts, nano-reinforcing filler: 3-8 parts, environmentally friendly crosslinking agent: 1-5 parts, ultraviolet absorption stabilizer: 0.5-1 part, defoamer: 0.2-0.5 parts, and deionized water: 5-15 parts; The ultraviolet absorption stabilizer is the ultraviolet absorption stabilizer according to any one of claims 1-4; The bio-based polyol is at least one of methyl ricinoleate and corn starch-based polyol; The environmentally friendly plasticizer is at least one of triethyl acetylgic acid and trioctyl acetylgic acid; The nano-reinforced filler is modified nano-silica with a particle size of 20-50 nm; The modified nano-silica preparation method is as follows: nano-silica is dispersed in an ethanol-water mixed solvent, ultrasonically treated to form a uniform suspension, then silane coupling agent KH-550 is added, the pH is adjusted to 4-5 with acetic acid, and the reaction is mechanically stirred at 60-70℃ for 2-4 hours. The solid is separated by centrifugation, unreacted substances are removed by washing with ethanol, and the modified nano-silica is obtained by vacuum drying at 60℃. The environmentally friendly crosslinking agent is at least one of epichlorohydrin and formaldehyde-free isocyanate crosslinking agents; The defoamer is at least one of dimethylsiloxane and polyoxypropylene.

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