Anti-yellowing master batch for polyurethane elastic fiber, preparation method and application thereof in shoe materials

Abstract

The application discloses an anti-yellowing master batch for polyurethane elastic fiber, a preparation method thereof and application of the anti-yellowing master batch in shoe materials, and belongs to the technical field of anti-yellowing master batches. The anti-yellowing master batch for polyurethane elastic fiber is composed of polyurethane resin, an anti-ultraviolet additive, a thermal oxidation stabilizer, nano additive A and nano additive B. The preparation method of the nano additive A is as follows: zinc chloride and water are added into a mixing device, stirring is carried out at room temperature, mixing is carried out with titanium dioxide, ultrasonic dispersion is carried out, titanium dioxide is separated out, washing and drying are carried out, and treated titanium dioxide is obtained; the light stabilizer after drying is added into a banbury mixer together with the treated titanium dioxide and polyvinyl alcohol, banburying is carried out at 135-140 DEG C, and grinding is carried out. The anti-yellowing master batch prepared by the application has small influence on the anti-yellowing performance and melt flow performance of the anti-yellowing master batch by the anti-ultraviolet additive and the thermal oxidation stabilizer, and the polyurethane elastic fiber prepared from the anti-yellowing master batch has good mechanical properties and oil resistance.

Description

Technical Field

[0001] This invention relates to the field of anti-yellowing masterbatch technology, specifically to an anti-yellowing masterbatch for polyurethane elastic fibers, its preparation method, and its application in footwear materials. Background Technology

[0002] Polyurethane is a high-molecular-weight polymer containing numerous urethane or urea groups in its main chain. It is a block polymer composed of soft and hard segments. Polyurethane fiber, also known as spandex, is a fiber made primarily from polyurethane. In the polyurethane structure, due to the structural differences between the hard and soft segments, there is thermodynamic incompatibility. Furthermore, the polar groups such as urethane and urea groups in the hard segments have high cohesive energy, easily forming associative microdomains, leading to microphase separation structures in the polyurethane. In addition, because the area of ​​the soft segment microdomains is larger than that of the hard segment microdomains, the hard segment microdomains act like "islands" distributed within the soft segment microdomains, playing a role in physical cross-linking at room temperature. Based on the unique microphase separation structure described above, polyurethane fibers are elastic fibers with rubber-like stretching properties and possess the following advantages: excellent abrasion resistance, which is 2-10 times that of natural rubber; within the same elastic range, its strength is 2-3 times higher than that of latex filaments, and its linear density is lower; excellent corrosion resistance, oxidation resistance, seawater resistance, and chemical degradation resistance; excellent fatigue resistance and vibration resistance, making it suitable for high-frequency flexural applications; and excellent impact resistance and low-temperature flexibility.

[0003] Based on the aforementioned advantages of polyurethane elastic fibers, they have experienced rapid development and are widely used in elastic fabrics such as shirts, tennis shorts, and knitted outerwear. Furthermore, they are beginning to be used as shoe upper materials. However, as analyzed by You Gexin et al. in "UV Aging Characteristics and Analysis of Polyurethane Fibers" (Engineering Plastics Application, 2017), polyurethane undergoes damage to its urethane structure after UV irradiation, exhibiting two fracture modes: CO bond breakage and CN bond breakage. Furthermore, with increasing irradiation time, both tensile strength and elongation decrease. UV aging time is positively correlated with the content of carboxyl groups at the polyester end, and with increasing aging time, mechanical properties deteriorate. A small amount of urethane bonds also break, generating enamines that cause yellowing. Similarly, as analyzed by Jiang Shu et al. in "Research Progress on Factors Affecting the Aging Performance of Spandex" (Synthetic Fibers, 2018), spandex has poor environmental resistance, limiting its application areas. Humidity, high temperature, and light exposure significantly affect the mechanical properties of polyurethane fibers and their composites. For example, Wang Jing et al., in their study "Research Progress on Yellowing Resistance of Polyurethane Materials" (Guangzhou Chemical Industry, 2016), analyzed that polyurethane materials are prone to photo-oxidative aging phenomena such as yellowing, cracking, and decreased mechanical properties during outdoor use. During this aging process, polyurethane materials exhibit yellowing, a phenomenon known as yellowing. Yellowing not only affects the appearance of polyurethane materials but also serves as a warning sign regarding changes in their structure and properties. In summary, since most footwear materials need to adapt to different outdoor environments, and polyurethane elastic fibers have poor environmental resistance, their yellowing resistance is poor, thus affecting their application in footwear materials.

[0004] To address the poor yellowing resistance of polyurethane elastic fibers, common solutions, as analyzed by Wang Jing et al. in "Research Progress on Yellowing Resistance of Polyurethane Materials" (Guangzhou Chemical Industry, 2016), involve preparing yellowing-resistant polyurethane materials by selecting low-saturation polyether polyols and aliphatic diisocyanates, and adding UV-resistant additives, thermal oxidation stabilizers, and nano-additives to polyurethane elastic fibers. Functional masterbatches for fibers are granular functional materials obtained through melt extrusion processing, using thermoplastic polymers as carriers, high-content micro / nano functional powders as the main body, and adding a small amount of additives. Directly adding additives to polyurethane results in poor dispersibility; adding them in the form of functional masterbatches for fibers is more convenient and efficient. Furthermore, different functional additives can impart special properties to plastics, such as antistatic properties, flame retardancy, wear resistance, antibacterial properties, and antioxidant properties. As Cai Yong et al. analyzed in "Research on Flame Retardancy, Toughening and Anti-Yellowing of PBT Materials for Energy-Saving Lamps" (Engineering Plastics Application, 2012), anti-yellowing masterbatch can significantly reduce the color change of PBT materials after xenon lamp aging tests. Therefore, adding anti-yellowing masterbatch containing UV stabilizers, thermal oxidation stabilizers, and nano-additives to polyurethane elastic fibers can better facilitate the dispersion of UV stabilizers, thermal oxidation stabilizers, and nano-additives, and thus better enable them to exert their effects.

[0005] However, the following problems exist in the preparation and application of anti-yellowing masterbatch for polyurethane elastic fibers: Nanoparticles possess characteristics such as surface effects, small size effects, quantum size effects, and macroscopic quantum tunneling effects. The quantum size effect of nanoparticles causes a blue shift in the absorption of certain wavelengths, and the absorption of different wavelengths of light by nanoparticles exhibits broadening. However, due to their high surface energy, nanoparticles are prone to aggregation and have poor compatibility with polyurethane, which affects the mechanical properties of polyurethane. For example, An Shaodu's research on "Improved Oil Extraction Resistance of Anti-UV Aging Agents for Thermoplastic Polyurethane" (China University of Petroleum, 2022) illustrates this. Analysis shows that thermoplastic polyurethane elastomers exhibit outstanding wear resistance and fatigue resistance, good oil and chemical resistance, excellent mechanical properties, and are easy to process. However, they are subject to ultraviolet light during outdoor use, which can cause aging. Currently, the main way to improve the ultraviolet stability of polyurethane is to add organic anti-ultraviolet aging agents. However, organic anti-ultraviolet aging agents have poor oil resistance, which in turn leads to poor oil resistance of thermoplastic polyurethane. Anti-ultraviolet additives and thermal oxidation stabilizers may affect the melt flowability of the carrier resin used in anti-yellowing masterbatch, thereby affecting the blending of anti-yellowing masterbatch and matrix resin, as well as the uniform dispersion of anti-ultraviolet additives, thermal oxidation stabilizers, and nano-additives.

[0006] Furthermore, in response to the above problems, after research and analysis, the commonly used solutions are: surface chemical modification of nano-additives (e.g., coupling agents); grafting anti-UV additives onto the surface of nano-additives; and controlling the amount of anti-UV additives and thermal oxidation stabilizers to avoid the use of anti-UV additives and thermal oxidation stabilizers. However, the above solutions have the following problems: For example, as analyzed by Zhang Yi et al. in "Research Progress on Surface Modification of Ultrafine Calcium Carbonate Powder and Its Functional Masterbatch" (Chemical Research, 2025), surface chemical modification utilizes surface modifiers to chemically react with functional groups on the local surface of nano-additives to achieve the purpose of modification. However, the surface uniformity is poor after surface chemical modification, which limits the improvement of the dispersibility of nano-additives and their compatibility with polyurethane. Similarly, as analyzed by An Shaodu in "Research on Improvement of Oil Extraction Resistance of Thermoplastic Polyurethane Anti-UV Aging Agents" (China University of Petroleum, 2022), the reaction of hydroxyl groups on the surface of titanium dioxide with the organic UV absorber 2-(2-hydroxy-5-benzyl)benzotriazole is used to modify the organic UV absorber 2-(2-hydroxy- 5-Benzotriazole (2-(2-hydroxy-5-benzyl)benzotriazole) grafted onto inorganic nano-titanium dioxide particles improves their oil extraction resistance. However, Figure 2.16 in the literature shows that after grafting the organic UV absorber 2-(2-hydroxy-5-benzyl)benzotriazole onto inorganic nano-titanium dioxide particles, the anti-yellowing performance is lower than that of adding the organic UV absorber 2-(2-hydroxy-5-benzyl)benzotriazole alone. This indicates that grafting the UV absorber onto the surface of the nano-additive affects the anti-yellowing performance of the UV absorber. Analysis suggests that this may be related to the uneven grafting of the UV absorber 2-(2-hydroxy-5-benzyl)benzotriazole onto the titanium dioxide surface, or it may be related to the influence of titanium dioxide on the UV absorption performance of the UV absorber 2-(2-hydroxy-5-benzyl)benzotriazole. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides an anti-yellowing masterbatch for polyurethane elastic fibers, its preparation method, and its application in footwear materials. The prepared anti-yellowing masterbatch exhibits excellent anti-yellowing properties and melt flow properties that are less affected by UV stabilizers and thermal oxidation stabilizers. The polyurethane elastic fibers prepared from the anti-yellowing masterbatch also demonstrate good mechanical properties and oil resistance.

[0008] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A polyurethane elastic fiber anti-yellowing masterbatch, by weight, is composed of the following raw materials: 70-75 parts polyurethane resin, 10-12 parts UV-resistant additive, 4-4.5 parts thermal oxidation stabilizer, 6-7 parts nano-additive A, and 10-12 parts nano-additive B. The polyurethane resin has a melt flow index of 10-30 g / 10 min at 190°C and 2.16 kg. The UV stabilizer is one or a combination of hindered amine light stabilizers, benzotriazole light stabilizers, and triazine light stabilizers; The hindered amine light stabilizer is one or a combination of light stabilizer 944, light stabilizer 622, light stabilizer 788, light stabilizer GW-508, and light stabilizer GW-540. The benzotriazole light stabilizer is one or a combination of ultraviolet absorbers UV-P, UV-320, UV-326, and UV-327. The triazine light stabilizer is one or a combination of UV absorbers UV-1577, UV absorber UV-425, UV absorber UV-1164, UV absorber UV-405, and UV absorber UV-1600. The thermal oxidation stabilizer is one or a combination of antioxidant 168, antioxidant 626, and antioxidant 1010; The preparation method of the nano-additive A is as follows: zinc chloride and water are added to a mixing device and stirred at room temperature for 10-30 min, with the stirring speed controlled at 100-300 r / min. The mixture is then mixed with titanium dioxide, ultrasonically dispersed, and the titanium dioxide is separated by centrifugation. The titanium dioxide is then washed and vacuum dried to obtain treated titanium dioxide. The vacuum-dried light stabilizer, treated titanium dioxide, and polyvinyl alcohol are added to a mixer and mixed at 135-140℃ for 40-50 min. The mixture is then transferred to a ball mill and ground for 40-60 min to obtain nano-additive A. In the preparation of the nano-additive A, the ratio of zinc chloride, water, titanium dioxide, vacuum-dried light stabilizer, and polyvinyl alcohol is 50-55g:10-12L:800-850g:400-420g:90-100g. The ultrasonic dispersion frequency is 20-30kHz, and the ultrasonic dispersion time is 20-30min. When washing and vacuum drying, and when vacuum drying the light stabilizer, the vacuum drying temperature is 75-85℃. The rotation speed during internal mixing is 90-100 r / min; The grinding speed is 300-350 r / min; The titanium dioxide is rutile titanium dioxide with an average particle size of 100-200 nm. The light stabilizer is the ultraviolet absorber UV-P; The polyvinyl alcohol is polyvinyl alcohol 2499; The preparation method of the nano-additive B is as follows: zinc chloride and the first part of water are added to a mixing device, and the mixture is stirred at room temperature for 10-30 min, with the stirring speed controlled at 100-300 r / min. The mixture is then mixed with titanium dioxide, ultrasonically dispersed, transferred to a mixing device, and stirred at 40-50℃ for 4-5 h, with the stirring speed controlled at 200-500 r / min. Titanium dioxide is separated by centrifugation, washed and vacuum dried, and transferred to a mixing vessel. Polyethylene glycol, Tween, and the second part of water are added to the mixing vessel, and the mixture is stirred at room temperature for 2-3 h, with the stirring speed controlled at 50-100 r / min. Titanium dioxide is separated by centrifugation, washed and vacuum dried to obtain nano-additive B. In the preparation of the nano-additive B, the ratio of zinc chloride, the first part of water, titanium dioxide, polyethylene glycol, Tween, and the second part of water is 50-55g:10-12L:800-850g:14-16g:45-50g:1-1.2L. The ultrasonic dispersion frequency is 20-30kHz, and the ultrasonic dispersion time is 20-30min. When washing and vacuum drying, the vacuum drying temperature is 75-85℃; The titanium dioxide is rutile titanium dioxide with an average particle size of 100-200 nm. The polyethylene glycol is polyethylene glycol 200; The Tween is Tween-80.

[0009] A method for preparing the aforementioned anti-yellowing masterbatch for polyurethane elastic fibers includes the following steps: adding polyurethane resin, UV stabilizer, thermal oxidation stabilizer, nano-additive A, and nano-additive B into a twin-screw extruder, melting and blending them at 180-190°C, and then extruding, cooling, and pelletizing to obtain the anti-yellowing masterbatch for polyurethane elastic fibers.

[0010] An application of the aforementioned anti-yellowing masterbatch for polyurethane elastic fibers in footwear materials involves adding the aforementioned anti-yellowing masterbatch for polyurethane elastic fibers to polyurethane resin. When adding the masterbatch, the mass ratio of the anti-yellowing masterbatch for polyurethane elastic fibers is controlled to be 4-6%. After mixing evenly, polyurethane elastic fibers with a fineness of 10-30 dtex are produced. Then, the polyurethane elastic fibers are used in the preparation of footwear upper materials.

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) In this invention, nano-additive A and nano-additive B are used simultaneously. When preparing nano-additive A, zinc chloride is first used to treat titanium dioxide. Zinc ions are adsorbed on the surface of titanium dioxide, which is beneficial for polyvinyl alcohol to bind to the surface of titanium dioxide in the later stage and can also reduce the aggregation of titanium dioxide. Then, light stabilizer and polyvinyl alcohol are used for treatment. Polyvinyl alcohol can bind to the surface of titanium dioxide through the interaction with zinc ions. The light stabilizer can be adsorbed on the surface of titanium dioxide. Polyvinyl alcohol can also promote the uniform dispersion of light stabilizer through hydrogen bonding with light stabilizer. As analyzed by Wang Shanwei et al. in "Research Progress of Benzotriazole Light Stabilizers" (Plastic Manufacturing, 2011), the intramolecular hydrogen bonds of benzotriazole are directly related to the light stabilization effect. The stronger the hydrogen bond, the greater the energy required to break it, the more light energy absorbed, and the higher the stabilization effect. In this invention, through the hydrogen bonding between polyvinyl alcohol and light stabilizer, the internal hydrogen bonding of light stabilizer can also be improved, thereby improving the stabilization effect of light stabilizer. In preparing nano-additive B, titanium dioxide is first treated with zinc chloride. Zinc ions adsorb onto the surface of titanium dioxide, which facilitates the subsequent binding of surfactants to the titanium dioxide surface and reduces titanium dioxide agglomeration. Then, polyethylene glycol and Tween surfactants are compounded and used to treat titanium dioxide. Polyethylene glycol and Tween have a synergistic effect, promoting the dispersion of titanium dioxide. They also have a synergistic effect when binding UV stabilizers and thermal oxidation stabilizers through hydrophobic groups, thereby promoting the uniform dispersion of UV stabilizers and thermal oxidation stabilizers. Furthermore, zinc ions can bind more polyethylene glycol and Tween through the interaction with the hydroxyl groups of polyethylene glycol and Tween, further improving the dispersion effect of polyethylene glycol and Tween. Furthermore, as analyzed in Figure 2.16 of An Shaodu's "Research on Improvement of Oil Extraction Resistance of Thermoplastic Polyurethane Anti-UV Aging Agent" (China University of Petroleum, 2022), the anti-yellowing performance of adding light stabilizer alone and adding titanium dioxide grafted with light stabilizer differs significantly at different aging times. It is speculated that the anti-yellowing mechanisms of the two are somewhat different. Therefore, this invention can achieve multiple anti-yellowing effects by combining nano-additive A, anti-UV auxiliary agent and nano-additive B + light stabilizer.

[0012] (2) The melt index of the anti-yellowing masterbatch of the present invention at 190℃ and 2.16kg is 19.1-20.0g / 10min, and the light fastness grade of the fabric prepared by the anti-yellowing masterbatch of the present invention can reach 4.8-5; after the anti-yellowing masterbatch of the present invention is impregnated with liquid paraffin, the light fastness grade of the fabric prepared can reach 4.5-5; the tensile strength of the polyurethane fiber prepared by the anti-yellowing masterbatch of the present invention is 2.20-2.26cN / dtex, and the elongation at break is 501-517%. Detailed Implementation

[0013] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention are now described.

[0014] Example 1 This embodiment provides an anti-yellowing masterbatch for polyurethane elastic fibers, which is composed of the following raw materials by weight: 70 parts polyurethane resin, 10 parts UV-resistant additive, 4 parts thermal oxidation stabilizer, 6 parts nano-additive A, and 10 parts nano-additive B. The polyurethane resin has a melt index of 20 g / 10 min at 190°C and 2.16 kg. The UV-resistant additive is light stabilizer 944; The thermal oxidation stabilizer is antioxidant 168; The preparation method of the nano-additive A is as follows: 50g of zinc chloride and 10L of water are added to a mixing vessel and stirred at room temperature for 20min, with the stirring speed controlled at 200r / min. 800g of titanium dioxide is then mixed and ultrasonically dispersed for 20min, with the ultrasonic frequency controlled at 20kHz. The titanium dioxide is separated by centrifugation, washed with water, and vacuum dried at 80℃ to obtain treated titanium dioxide. After vacuum drying the light stabilizer at 80℃, 400g of the vacuum-dried light stabilizer, all the above-mentioned treated titanium dioxide, and 90g of polyvinyl alcohol are added to a mixer and kneaded at 135℃ for 40min, with the stirring speed controlled at 100r / min. Then, the mixture is transferred to a ball mill and ground for 40min, with the grinding speed controlled at 300r / min, to obtain nano-additive A. The titanium dioxide is rutile titanium dioxide with an average particle size of 200 nm. The light stabilizer is the ultraviolet absorber UV-P; The polyvinyl alcohol is polyvinyl alcohol 2499; The preparation method of the nano-additive B is as follows: 50g of zinc chloride and 10L of water are added to a mixing vessel and stirred at room temperature for 20 minutes, with the stirring speed controlled at 200r / min. 800g of titanium dioxide is then mixed and ultrasonically dispersed for 20 minutes, with the ultrasonic frequency controlled at 20kHz. The mixture is then transferred to a mixing vessel and stirred at 45℃ for 4 hours, with the stirring speed controlled at 200r / min. Titanium dioxide is separated by centrifugation, washed with water, and vacuum dried at 80℃. The mixture is then transferred to a mixing vessel, and 15g of polyethylene glycol, 45g of Tween, and 1L of water are added. The mixture is stirred at room temperature for 2 hours, with the stirring speed controlled at 50r / min. Titanium dioxide is separated by centrifugation, washed with water, and vacuum dried at 80℃ to obtain nano-additive B. The titanium dioxide is rutile titanium dioxide with an average particle size of 200 nm. The polyethylene glycol is polyethylene glycol 200; The Tween is Tween-80.

[0015] This embodiment also provides a method for preparing the aforementioned anti-yellowing masterbatch for polyurethane elastic fibers, comprising the following steps: adding polyurethane resin, UV-resistant additive, thermal oxidation stabilizer, nano-additive A, and nano-additive B into a twin-screw extruder, melting and blending at 180°C, and then extruding, cooling, and pelletizing to obtain the anti-yellowing masterbatch for polyurethane elastic fibers.

[0016] This embodiment also provides an application of the aforementioned anti-yellowing masterbatch for polyurethane elastic fibers in footwear materials. The aforementioned anti-yellowing masterbatch for polyurethane elastic fibers is added to polyurethane resin. When adding, the mass ratio of the anti-yellowing masterbatch for polyurethane elastic fibers is controlled to be 5%. After mixing evenly, polyurethane elastic fibers with a fineness of 30 dtex are produced. Then, the polyurethane elastic fibers are used in the preparation of footwear upper materials.

[0017] Example 2 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The UV-resistant additive was replaced with light stabilizer 622, while the weight percentage of the UV-resistant additive remained unchanged.

[0018] Example 3 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The UV-resistant additive was replaced with light stabilizer 788, while the weight percentage of the UV-resistant additive remained unchanged.

[0019] Example 4 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The UV-resistant additive was replaced with the light stabilizer GW-508, while the weight percentage of the UV-resistant additive remained unchanged.

[0020] Example 5 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The UV-resistant additive was replaced with the light stabilizer GW-540, while the weight percentage of the UV-resistant additive remained unchanged.

[0021] Example 6 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The UV-resistant additive was replaced with UV-P, while the weight percentage of the UV-resistant additive remained unchanged.

[0022] Example 7 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The UV-resistant additive was replaced with UV-320, while the weight percentage of the UV-resistant additive remained unchanged.

[0023] Example 8 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The UV-resistant additive was replaced with UV-326, while the weight percentage of the UV-resistant additive remained unchanged.

[0024] Example 9 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The UV-resistant additive was replaced with UV-327, while the weight percentage of the UV-resistant additive remained unchanged.

[0025] Example 10 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The UV-resistant additive was replaced with UV absorber UV-1577, while the weight percentage of the UV-resistant additive remained unchanged.

[0026] Example 11 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The UV-resistant additive was replaced with UV-425, while the weight percentage of the UV-resistant additive remained unchanged.

[0027] Example 12 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The UV-resistant additive was replaced with UV absorber UV-1164, while the weight percentage of the UV-resistant additive remained unchanged.

[0028] Example 13 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The UV-resistant additive was replaced with UV-405, while the weight percentage of the UV-resistant additive remained unchanged.

[0029] Example 14 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The UV-resistant additive was replaced with UV-1600, while the weight percentage of the UV-resistant additive remained unchanged.

[0030] Example 15 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The thermal oxidation stabilizer is antioxidant 626, and the weight percentage of the thermal oxidation stabilizer remains unchanged.

[0031] Example 16 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The thermal oxidation stabilizer is antioxidant 1010, and the weight parts of the thermal oxidation stabilizer remain unchanged.

[0032] Comparative Example 1 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The preparation method of nano-additive A was changed as follows: After vacuum drying the light stabilizer at 80°C, 400g of vacuum-dried light stabilizer and 800g of titanium dioxide were added to a mixer and mixed at 135°C for 40 minutes. During the mixing, the speed was controlled to 100r / min. Then, the mixture was transferred to a ball mill and ground for 40 minutes. During the grinding, the speed was controlled to 300r / min to obtain nano-additive A. The titanium dioxide is rutile titanium dioxide with an average particle size of 200 nm. The light stabilizer is UV-P, an ultraviolet absorber.

[0033] The weight percentage of nano-additive A in the anti-yellowing masterbatch for polyurethane elastic fibers remains unchanged.

[0034] Comparative Example 2 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The preparation method of nano-additive B was changed as follows: 800g of titanium dioxide, 15g of polyethylene glycol, 45g of Tween and 1L of water were added to a mixing vessel and stirred at room temperature for 2 hours. During stirring, the speed was controlled to 50r / min. Titanium dioxide was separated by centrifugation, washed with water and dried under vacuum at 80℃ to obtain nano-additive B. The titanium dioxide is rutile titanium dioxide with an average particle size of 200 nm. The molar concentration of the hydrochloric acid aqueous solution is 1 mol / L.

[0035] The polyethylene glycol is polyethylene glycol 200; The Tween is Tween-80.

[0036] The weight percentage of nano-additive B in the anti-yellowing masterbatch for polyurethane elastic fibers remains unchanged.

[0037] Comparative Example 3 The composition, preparation method, and application method of the anti-yellowing masterbatch for polyurethane elastic fibers are basically the same as those in Example 1, with the only difference being: The nano-additive B was replaced with untreated rutile titanium dioxide with an average particle size of 200 nm.

[0038] The weight percentage of nano-additive B in the anti-yellowing masterbatch for polyurethane elastic fibers remains unchanged.

[0039] Application examples 1. The melt flow index of the polyurethane elastic fibers prepared in Examples 1-16 and Comparative Examples 1-3 using the anti-yellowing masterbatch was tested at 190°C and 2.16 kg. The test results are as follows (five samples were taken during the test, and the average value was taken):

[0040] 2. The polyurethane elastic fibers prepared from the anti-yellowing masterbatch obtained in Examples 1-16 and Comparative Examples 1-3 were woven with cotton-viscose blended yarn (wherein the mass ratio of cotton fiber to viscose fiber was 75:18, and the count of the cotton-viscose blended yarn was 40 English count) at a mass ratio of 7:93 to obtain a weight of 210 g / m². 2 The fabric was tested for light fastness according to Option 3 of AATCC 16-2004. The test results are as follows (10 samples were taken during the test, and the average value was taken):

[0041] When testing lightfastness according to Option 3 of AATCC 16-2004, a xenon lamp was used as the light source. Color change was assessed using AATCC grayscale levels; the assessment was divided into five levels, as follows: Level 5 - Negligible or no color change or staining / color transfer; Level 4 - Slight to negligible color change or transfer of dyed color; Level 3 - Obvious color change or staining / color transfer; Grade 2 - Significant color change or staining / color transfer; Level 1 - Greater color variation or staining / color transfer.

[0042] 3. The anti-yellowing masterbatches prepared in Examples 1-16 and Comparative Examples 1-3 were added to liquid paraffin at a mass ratio of 1:10. The mixture was stirred at 50°C for 30 minutes, with the stirring speed controlled at 100 r / min. Then, following the methods described in Examples 1-16 and Comparative Examples 1-3, it was mixed with polyurethane resin to form polyurethane elastic fibers. These fibers were then woven with cotton-viscose blended yarn according to the method described in step 2 to obtain the fabric. The light fastness was then tested according to Option 3 of AATCC 16-2004. The test results are as follows (10 samples were taken during the test, and the average value was used):

[0043] 4. The tensile strength and elongation at break of the polyurethane elastic fibers prepared from the anti-yellowing masterbatch in Examples 1-16 and Comparative Examples 1-3 were tested. The test results are as follows (five samples were taken during the test, and the average value was taken):

[0044] The above results show that nano-additives A and B, prepared by specific methods, can improve the anti-yellowing properties and oil resistance of the prepared anti-yellowing masterbatch, reduce the impact on the melt flow properties of polyurethane, and improve the mechanical properties of polyurethane elastic fibers prepared from the anti-yellowing masterbatch.

Claims

1. A polyurethane elastic fiber anti-yellowing masterbatch, characterized in that, By weight, it is composed of the following raw materials: 70-75 parts polyurethane resin, 10-12 parts UV-resistant additive, 4-4.5 parts thermal oxidation stabilizer, 6-7 parts nano additive A, and 10-12 parts nano additive B. The preparation method of the nano-additive A is as follows: zinc chloride and water are added to a mixing device, stirred at room temperature, mixed with titanium dioxide, ultrasonically dispersed, and titanium dioxide is separated by centrifugation, washed and vacuum dried to obtain treated titanium dioxide; the vacuum-dried light stabilizer, treated titanium dioxide, and polyvinyl alcohol are added to a mixer and mixed at 135-140℃ for 40-50 min, and ground for 40-60 min to obtain nano-additive A; The preparation method of the nano-additive B is as follows: zinc chloride and the first part of water are added to a mixing device, stirred at room temperature, mixed with titanium dioxide, ultrasonically dispersed, transferred to a mixing device, stirred at 40-50°C, titanium dioxide is separated by centrifugation, washed and vacuum dried, transferred to a mixing vessel, polyethylene glycol, Tween, and the second part of water are added to the mixing vessel, stirred at room temperature, titanium dioxide is separated by centrifugation, washed and vacuum dried to obtain nano-additive B.

2. The anti-yellowing masterbatch for polyurethane elastic fibers according to claim 1, characterized in that, The polyurethane resin has a melt flow index of 10-30 g / 10 min at 190°C and 2.16 kg.

3. The anti-yellowing masterbatch for polyurethane elastic fibers according to claim 1, characterized in that, The UV stabilizer is one or a combination of hindered amine light stabilizers, benzotriazole light stabilizers, and triazine light stabilizers; The hindered amine light stabilizer is one or a combination of light stabilizer 944, light stabilizer 622, light stabilizer 788, light stabilizer GW-508, and light stabilizer GW-540. The benzotriazole light stabilizer is one or a combination of ultraviolet absorbers UV-P, UV-320, UV-326, and UV-327. The triazine light stabilizer is one or a combination of UV absorbers UV-1577, UV absorber UV-425, UV absorber UV-1164, UV absorber UV-405, and UV absorber UV-1600. The thermal oxidation stabilizer is one or a combination of antioxidant 168, antioxidant 626, and antioxidant 1010.

4. The anti-yellowing masterbatch for polyurethane elastic fibers according to claim 1, characterized in that, In the preparation of the nano-additive A, the ratio of zinc chloride, water, titanium dioxide, vacuum-dried light stabilizer, and polyvinyl alcohol is 50-55g:10-12L:800-850g:400-420g:90-100g. The ultrasonic dispersion frequency is 20-30kHz, and the ultrasonic dispersion time is 20-30min. The vacuum drying temperature is 75-85℃ during both washing and vacuum drying and when vacuum drying the light stabilizer. The rotation speed during internal mixing is 90-100 r / min; The grinding speed is 300-350 r / min; The titanium dioxide is rutile titanium dioxide with an average particle size of 100-200 nm. The light stabilizer is the ultraviolet absorber UV-P; The polyvinyl alcohol is polyvinyl alcohol 2499.

5. The anti-yellowing masterbatch for polyurethane elastic fibers according to claim 1, characterized in that, In the preparation of the nano-additive B, the ratio of zinc chloride, the first part of water, titanium dioxide, polyethylene glycol, Tween, and the second part of water is 50-55g:10-12L:800-850g:14-16g:45-50g:1-1.2L. The ultrasonic dispersion frequency is 20-30kHz, and the ultrasonic dispersion time is 20-30min. When washing and vacuum drying, the vacuum drying temperature is 75-85℃; The titanium dioxide is rutile titanium dioxide with an average particle size of 100-200 nm. The polyethylene glycol is polyethylene glycol 200; The Tween is Tween-80.

6. A method for preparing an anti-yellowing masterbatch for polyurethane elastic fibers according to any one of claims 1-5, characterized in that, The preparation method includes the following steps: adding polyurethane resin, UV-resistant additive, thermal oxidation stabilizer, nano-additive A, and nano-additive B into a twin-screw extruder, melting and blending them at 180-190℃, and then extruding, cooling, and pelletizing to obtain anti-yellowing masterbatch for polyurethane elastic fibers.

7. The application of the anti-yellowing masterbatch for polyurethane elastic fibers according to any one of claims 1-5 in footwear materials, characterized in that, Polyurethane elastic fiber anti-yellowing masterbatch is added to polyurethane resin. When adding it, the mass ratio of polyurethane elastic fiber anti-yellowing masterbatch is controlled to be 4-6%. After mixing evenly, polyurethane elastic fiber with a fineness of 10-30 dtex is made. Then, polyurethane elastic fiber is used in the preparation of shoe upper materials.

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