Ultraviolet light-cured fluorosilicon finishing material, preparation method and application thereof

Abstract

The present application relates to UV-curable fluorosilicone finishing material and its preparation method and application. Under the action of alkaline catalyst, the present application utilizes the reaction of D3F and silane coupling agent to prepare a series of fluorine-containing silicone oils with different fluorine contents, which can be photo-crosslinking cured under UV irradiation. The fluorine-containing silicone oil is used for finishing base cloth to prepare modified base cloth with good hydrophobic effect. The fluorine-containing silicone oil prepared by the present application has high yield, simple reaction process, easy operation and short reaction time. The fluorine-containing silicone oil can be chemically modified to realize the conversion of base cloth from relatively hydrophobic to more hydrophobic, and the thermal stability is increased. Clean production is of great significance to the development of new materials for leather making.

Description

Technical Field

[0001] This invention relates to ultraviolet-curable fluorosilicone coating materials, their preparation methods and applications, and belongs to the field of new materials. Background Technology

[0002] After years of development, China has become a global leader in the genuine leather manufacturing industry. With continuous technological advancements, the demand for genuine leather products is also increasing. Besides aesthetic appeal and natural luster, consumers require genuine leather products to possess a refined appearance, a soft feel, and practicality. To meet these demands, surface finishing is necessary. This involves applying a protective coating to the leather surface, giving it a beautiful and uniform appearance to satisfy consumer preferences for color, feel, and luster. The main function of surface finishing is to improve the physical and chemical properties of the outer layer of the finished leather, thereby concealing or altering defects and flaws in the raw hide, increasing the utilization rate and quality of the leather, and allowing for diverse styles in the finished product. There are numerous reports on coating materials. For example, CN102911308A discloses a series of leather coating materials, such as: preparing spherical nano-SiO2 particles of different sizes using the sol-gel method, modifying the spherical small-size nano-SiO2 particles with γ-aminopropyltriethoxysilane (KH550), modifying the spherical large-size nano-SiO2 particles with γ-glycidoxypropyltrimethoxysilane (KH560), and then preparing a coating material with a dual-size composite structure of nano-SiO2 particles through covalent self-assembly.

[0003] In the finishing of genuine leather, feel agents play a crucial role, enhancing the feel and overall texture of the leather and effectively preventing common manufacturing issues such as panel bonding. Organosilicon is one such widely used substance in feel agents. Organosilicon is a synthetic organic polymer material whose coatings exhibit excellent film-forming properties, transparency, softness, and superior physicochemical and mechanical properties. Because the end and side groups of organosilicon molecules contain reactive functional groups, such as -NH2 and -OH, they can undergo polymerization reactions with highly efficient metal fillers, further improving the performance of organosilicon coatings, such as abrasion resistance and non-flammability. Therefore, organosilicon is widely used in feel agents for genuine leather products, endowing them with unique texture and quality characteristics.

[0004] Fluorinated silicone oil, as a special chemical, possesses a variety of properties and advantages, including high oil resistance, solvent resistance, and resistance to chemical corrosion. It also exhibits good lubrication, hydrophobicity, oleophobicity, self-release properties, defoaming, and anti-foaming properties. Due to its chemical resistance and excellent lubricity, fluorosilicone oil is particularly suitable for environments with prolonged contact with moisture, high heat, solvents, gasoline, and other chemicals. For example, Zhang Fei et al. from the School of Energy Engineering at Yulin University and the School of Civil Engineering at Chang'an University conducted a freeze-thaw cycle test to study the changes in the mechanical properties of fluorosilicone resin coatings after freeze-thaw cycles. They compared the results of brushed and uncoated fluorosilicone resin coatings (reference concrete) and compared the mass loss rate and compressive strength of epoxy coatings and silane coatings under freeze-thaw conditions. Scanning electron microscopy (SEM) was used to analyze the surface and sides of the fluorosilicone-coated concrete. The results showed that under freeze-thaw cycles, the mass and compressive strength loss rates of the coated concrete were relatively lower than those of the reference concrete, with the fluorosilicone-coated concrete showing the least damage. By examining flexural strength and butt joint strength samples of concrete coated with fluorosilicone material, it was found that the fluorosilicone coating exhibits good adhesion to the concrete. Scanning electron microscopy analysis indicates that the fluorosilicone resin coating, after hardening on the concrete surface, demonstrates high adhesion to the concrete, forming a protective film of a certain thickness, significantly improving the concrete's freeze-thaw resistance and durability.

[0005] Fluorinated silicone oils offer numerous advantages over other coating materials. They are organosilicon compounds with unique structures and superior properties, containing a bimolecular polymer backbone of repeating polysiloxane siloxane bonds. Within fluorinated silicone oils, the long Si-O-Si siloxane chains with large bond angles allow for cross-rotation between the bonds, forming a helical chain structure. Furthermore, the shielding effect of methyl groups within the siloxane chains results in a small interaction volume and very low surface tension, contributing to the excellent stability and fluidity of fluorinated silicone oils. They maintain long-term thermal stability at high temperatures, making them ideal for high-temperature lubrication and corrosion protection. Beyond lubrication and rust prevention, fluorinated silicone oils are also used in surface treatment and flame retardancy, finding wide application in industrial production.

[0006] Most fluorinated silicone oils on the market are perfluorosilicone oils, which are relatively expensive. Traditionally, they are used as functional additives to improve certain properties of the system. For example, vinyl perfluorosilicone oil is added to traditional addition-cure silicone rubber to improve its resistance to polar / non-polar solvents and oil. However, due to the high polarity of fluorinated silicone oils, they have poor compatibility with traditional vinyl silicone oils. Even after mixing and standing, the polarity difference can cause stratification, and after curing and crosslinking, there may be differences in shrinkage, leading to deterioration of mechanical properties. Furthermore, due to compatibility issues, the fluorine groups cannot be evenly distributed throughout the system after curing and crosslinking, significantly reducing these properties. Fluorinated silicone oils are used in lubrication, release agents, and thermal greases. If perfluorosilicone oil is used alone, its strong polarity and poor wetting properties result in poor performance. Using perfluorosilicone oil as an additive also presents compatibility issues with methyl silicone oil. Therefore, the research on fluorosilicone coating materials with good compatibility, suitable for coating leather, and which improve hydrophobicity and thermal stability after coating has become an urgent problem to be solved. To this end, this invention is proposed. Summary of the Invention

[0007] To address the shortcomings of existing technologies, particularly the strong polarity and poor wetting properties of fluorinated silicone oils, which are detrimental to leather finishing, this invention provides UV-curable fluorosilicone coating materials, their preparation methods, and applications. This invention uses a low-fluorinated silicone oil to replace methyl silicone oil, avoiding the poor compatibility issue between perfluorosilicone oil and methyl silicone oil. It uses a low-fluorinated fluorinated silicone oil with added vinyl end caps to replace traditional vinyl silicone oil, preparing an addition-cure adhesive with properties such as anti-flashover, resistance to polar / non-polar solvents, and oil resistance.

[0008] This invention explores the performance improvements of silane coupling agent KH570 after its reaction with D3F, including enhancing its heat resistance and oil resistance, and altering its polarity differences with different silicone oils to achieve a mixing and blending effect. Using ultraviolet curing to prepare the coating material not only results in low production costs and a relatively simple preparation process, but also improves the hydrophobicity and thermal stability of the leather after coating, while simultaneously imparting a pleasant hand feel to the leather material.

[0009] The technical solution adopted in this invention is as follows:

[0010] A UV-curable fluorosilicone coating material, which is obtained by a catalyst-catalyzed reaction of D3F and a silane coupling agent.

[0011] According to the present invention, preferably, the molecular structure of the silane coupling agent is generally an organic functional group -R-siloxane, such as γ-methacryloyloxypropyltrimethoxyorganosilane (KH570), etc.

[0012] Preferably, the D3F is 1,3,5-trimethyl-1,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane, which is a major monomer for preparing fluorosilicone rubber, fluorosilicone resin, and fluorosilicone oil, and can be copolymerized with a variety of monomers;

[0013] Preferably, the catalyst is an alkaline compound, such as tetramethylammonium hydroxide, sodium hydroxide, potassium hydroxide, etc.

[0014] According to the present invention, the preparation method of the above-mentioned UV-curable fluorosilicone coating material includes the following steps:

[0015] D3F, a portion of the catalyst, and water were refluxed at 100℃-130℃ for 0.5h-2h with stirring. Then, silane coupling agent and the remaining catalyst were added, and the mixture was stirred and refluxed at 120℃-140℃ for 2-3h. After the reaction was completed, the catalyst was removed by evaporation, and D3F and silane coupling agent were removed by vacuum distillation to obtain the fluorinated silicon coating material.

[0016] According to the present invention, preferably, the molar ratio of D3F to silane coupling agent is (7-9):(3-1).

[0017] According to the present invention, the application of the above-mentioned UV-curable fluorosilicone coating material in leather finishing agents is also provided.

[0018] According to the present invention, a method for modifying leather coating is also provided, comprising modifying raw hide material by coating with the above-mentioned ultraviolet-cured fluorosilicone coating material.

[0019] According to the present invention, preferably, the above-mentioned method for modifying synthetic leather includes the following steps:

[0020] Cut an appropriate amount of the base fabric to be modified into suitable sizes and immerse it in a UV-curable fluorosilicone coating material solution to ensure full penetration. After removal, cure it with a UV lamp, then vacuum dry it, irradiate it with a UV lamp again, and finally air dry it. The reaction is complete, and the modification of the base fabric by the UV-curable fluorosilicone coating material is finished.

[0021] According to the present invention, preferably, the substrate is immersed in the UV-curable fluorosilicone coating material for 1-3 hours; more preferably, the immersion is carried out under sealed conditions.

[0022] According to the present invention, preferably, the solvent used in the UV-curable fluorosilicone coating material solution is tetrahydrofuran;

[0023] Preferably, before immersion, a photoinitiator is added to the UV-curable fluorosilicone coating material solution, and DMPA (benzoyl dimethyl ether) photoinitiator is further preferred.

[0024] According to the present invention, modified raw hides are also provided, obtained by coating and modifying raw hide materials with the above-mentioned UV-curable fluorosilicone coating material. Preferably, the modified raw hides contain 0.2%-20% by mass of fluorosilane.

[0025] According to the present invention, the application of modified raw hides obtained by coating and modifying raw hides with the above-mentioned UV-curable fluorosilicone coating material is also provided in the leather industry.

[0026] According to the present invention, a preferred embodiment of the method for preparing ultraviolet-curable fluorosilicone coating materials includes the following steps:

[0027] Weigh 8-10g of D3F, 0.5-2g of silane coupling agent, and 0.7-0.9g of catalyst. First, mix D3F, catalyst, and 0.5g of distilled water in a three-necked flask, and react under mechanical stirring and reflux at 120℃ for one hour. Then, add the silane coupling agent and the remaining catalyst, and react under mechanical stirring and reflux at 130℃ for two hours. After the reaction is complete, put the reaction product into a single-necked flask, remove catalyst impurities by rotary evaporation, and remove D3F and silane coupling agent by vacuum distillation to obtain a colorless, transparent, viscous liquid, which is the UV-curable fluorosilicone coating material, a type of fluorosilicone oil.

[0028] According to the present invention, a preferred embodiment of the method for coating and modifying raw hide materials using the above-mentioned ultraviolet-cured fluorosilicone coating material includes the following steps:

[0029] Take 2-4g of UV-curable fluorosilicone coating material and place it in a 50-100mL beaker. Add 5-30mL of tetrahydrofuran solution and 0.10-0.12g of DMPA photoinitiator and dissolve them completely. Then, take an appropriate amount of base fabric, cut it into suitable sizes with scissors, and soak it in the UV-curable fluorosilicone coating material solution for 2-4 hours to ensure full penetration. After removing it, irradiate it with a UV lamp for 1 hour to initiate the reaction. Next, place the impregnated base fabric in a vacuum drying oven and dry it at 80-90℃ for about 1 hour. After removing it, irradiate it again with a UV lamp for 1 hour. Finally, remove the sample and place it in a fume hood to air dry, thus completing the coating modification of the base fabric.

[0030] The principle of this invention:

[0031] This invention prepares novel fluorosilicone oils based on traditional silicone oils, and utilizes these fluorosilicone oils to coat base fabrics. In this invention, for example, a series of fluorosilicone oils with different fluorine contents are generated by reacting a silane coupling agent (KH570) with D3F. The reaction process is relatively mild, and the reaction yield is high.

[0032] In the preparation process of fluorinated silicone oil of the present invention, KH570 (γ-methacryloyloxypropyltrimethoxysilane) and D3F (trifluoropropylmethylcyclotrisiloxane) are first used as raw materials, and tetramethylammonium hydroxide is used as a catalyst to obtain fluorinated polysiloxane products containing methacryloyloxypropyl side groups through anionic ring-opening polymerization reaction.

[0033] Taking D3F and KH570 as examples, the reaction technology route is as follows:

[0034]

[0035] This invention uses different amounts of D3F and KH570 to prepare coating materials with different fluorine contents. The alkoxy groups on the fluorinated silicone oil can interact with the hydroxyl groups on the collagen fibers to form multiple binding sites, realizing the effect of fluorinated silicone oil between collagen fibers. This transforms the original hydrophilic raw hide surface into a hydrophobic surface. The modification of fluorinated silicone oil can achieve good hydrophobic effect of the base fabric material, providing a good raw material foundation for the further preparation of high-performance leather.

[0036] The beneficial effects of this invention are as follows:

[0037] 1. The method for preparing fluorinated silicone oil of the present invention is simple, feasible, highly designable, has a high yield and is easy to scale up. The prepared fluorinated silicone oil has a novel structure, high thermal stability and adjustable fluorine content.

[0038] 2. The fluorinated silicone oil prepared in this invention modifies the collagen fibers of the base fabric, forming stable chemical bonds with the collagen fibers, thereby improving the thermal stability and hydrophobic effect of the base fabric. The surface hydrophobic effect can be improved from the hydrophilic effect of the base fabric to a hydrophobic angle greater than 133°.

[0039] 3. In the process of modifying base fabric materials with silicone oils of different fluorine contents according to the present invention, only two reaction steps are required to achieve coating and modification of the base fabric materials. The reaction operation is simple and the yield is high. The selection of fluorine-containing silicone oil can be adjusted according to the actual hydrophobic effect requirements. The amount of fluorine-containing silicone oil introduced into the base fabric can be adjusted by adjusting the modification process and the content of the selected silicone oil. The molecular structure of fluorine-containing silicone oil and the coating and modification process of base fabric materials can be adjusted according to specific needs to meet actual requirements, which is highly flexible. Attached Figure Description

[0040] Figure 1 The image shows the nuclear magnetic resonance spectrum of the fluorinated silicone oil obtained in Example 1 of this invention.

[0041] Figure 2 The infrared spectra of D3F, KH570 and fluorinated silicone oil obtained in Example 1 of this invention are shown.

[0042] Figure 3 This is a macroscopic photograph of the product in Embodiment 1 of the present invention.

[0043] Figure 4 The images are scanning electron microscope (SEM) images of the base fabric before and after coating in Experimental Example 2 of this invention. The base fabric collagen fibers are uncoated (top), and the base fabric collagen fibers are coated with fluorinated silicone oil (bottom).

[0044] Figure 5 Thermogravimetric analysis diagram of the fluorinated silicone oil-coated base fabric material in Experimental Example 3 of the present invention.

[0045] Figure 6 This is a diagram showing the hydrophobic properties of the base fabric material before and after different coatings in Experimental Example 4 of the present invention. Detailed Implementation

[0046] The UV-curable fluorosilicone coating material of this invention is a fluorinated silicone oil. In the preparation process, D3F and a silane coupling agent are first reacted under the action of a catalyst to obtain the fluorinated silicone oil.

[0047] In a preferred embodiment, the preparation process of the fluorinated silicone oil is as follows:

[0048] Weigh 8-10g of D3F, 0.5-2g of silane coupling agent and 0.7-0.9g of catalyst. First, mix D3F, catalyst and 0.5g of distilled water in a three-necked flask, and stir mechanically and reflux at 120℃ for one hour. Then add silane coupling agent and the remaining catalyst, and stir mechanically and reflux at 130℃ for two hours.

[0049] After the reaction is complete, the reaction product is placed in a single-necked flask, and impurities such as catalyst are removed by rotary evaporation. After removing D3F and silane coupling agent by vacuum distillation, a colorless and transparent viscous liquid is obtained, which is fluorinated silicone oil.

[0050] In this invention, when fluorinated silicone oil is used to coat and modify the base fabric material, the alkoxy groups on the fluorinated silicone oil can interact with the hydroxyl groups on the collagen fibers to form multiple binding sites, thereby realizing the effect of fluorinated silicone oil between the collagen fibers and transforming the original hydrophilic raw hide surface into a hydrophobic surface. The coating and modification of fluorinated silicone oil can achieve good hydrophobic effect of the base fabric material, providing a good raw material foundation for the further preparation of high-performance leather.

[0051] In a preferred embodiment, the process of coating and modifying the base fabric material with fluorinated silicone oil is as follows:

[0052] First, 2g of the synthesized fluorinated silicone oil was placed in a 50mL beaker, along with 15mL of tetrahydrofuran solution and 0.10g of DMPA photoinitiator, and allowed to dissolve completely. Then, a suitable amount of base fabric was taken, cut to the appropriate size, and immersed in the fluorinated silicone oil solution for 2 hours to ensure complete saturation. After removal, the fabric was irradiated with a UV lamp for 1 hour to initiate the reaction. Next, the impregnated base fabric was placed in a vacuum drying oven and dried at 80℃ for approximately 1 hour, then irradiated again with a UV lamp for 1 hour. Finally, the sample was removed and air-dried in a fume hood, thus completing the coating and modification of the base fabric with fluorinated silicone oil.

[0053] The present invention will be described in detail below through specific embodiments, but is not limited thereto.

[0054] All raw materials used in the examples were commercially available and all equipment used were conventional. The silane coupling agent used was KH570. The catalysts used were alkaline compounds, such as tetramethylammonium hydroxide, sodium hydroxide, and potassium hydroxide.

[0055] Example 1:

[0056] Weigh 10.000g D3F (21.34mmol), 1.302g (5.25mmol) silane coupling agent and 0.942g catalyst. Mix D3F, catalyst and 0.5g distilled water in a three-necked flask. Stir mechanically and reflux at 120℃ for one hour. Then add silane coupling agent and the remaining catalyst. Stir mechanically and reflux at 130℃ for two hours.

[0057] After the reaction is complete, the reaction product is placed in a single-necked flask, and impurities such as catalyst are removed by rotary evaporation. After removing D3F and silane coupling agent by vacuum distillation, a colorless and transparent viscous liquid is obtained, which is fluorinated silicone oil.

[0058] The NMR spectrum and infrared spectrum of the product obtained in this embodiment are as follows: Figure 1-2As shown, the 1H NMR spectrum of fluorinated silicone oil shows multiple peaks appearing in different chemical shift ranges. Let peak 4.85 ppm be labeled a, corresponding to the hydrogen atom of the methylene group; peak 4.07 ppm be labeled b, corresponding to the hydrogen atom of the methylene group; peak 5.53 ppm be labeled c, corresponding to the hydrogen atom of the methylene group; peak 3.11 ppm be labeled d, also corresponding to the hydrogen atom of the methylene group; peak 2.02 ppm be labeled e, corresponding to the hydrogen atom of the methylene or methyl group; similarly, peak 1.82 ppm is labeled f, corresponding to the hydrogen atom of the methylene or methyl group; peak 1.23 ppm is labeled g, corresponding to the hydrogen atom of the methylene group; peak 0.74 ppm is labeled h, corresponding to the hydrogen atom of alkylene groups such as ethyl groups; peak 0.15 ppm is labeled i, corresponding to the hydrogen atom of the methyl group; and peak 7.25 ppm is formed by the solvent deuterated chloroform. In the infrared spectrum of fluorinated silicone oil, we can find several stretching vibration absorption peaks, including one at 1712.7 cm⁻¹. -1 The carbonyl C=O stretching vibration absorption peak is at 1365.4 cm⁻¹. -1 The CO stretching vibration absorption peak, and 902.7 cm⁻¹ -1 The absorption peak of the Si-O stretching vibration at 2964.5 cm⁻¹ is also observed. -1 The absorption peak of the CH stretching vibration on CH2 at 758.1 cm⁻¹ -1 The out-of-plane bending vibration absorption peak at 1631.8 cm⁻¹ is also visible in the spectrum. -1 The characteristic infrared absorption peak of the C=C double bond was also observed. Furthermore, a peak at 1012.6 cm⁻¹ was observed. -1 The CF stretching vibration absorption peak at [location missing] is another significant feature of this spectrum. In conclusion, the reaction was successful, and the structure of the obtained product is as expected.

[0059] Example 2:

[0060] Weigh 10.000g D3F (21.34mmol), 0.556g (2.37mmol) silane coupling agent and 0.942g catalyst. Mix D3F, catalyst and 0.5g distilled water in a three-necked flask. Stir mechanically and reflux at 120℃ for one hour. Then add silane coupling agent and the remaining catalyst. Stir mechanically and reflux at 130℃ for two hours.

[0061] After the reaction is complete, the reaction product is placed in a single-necked flask, and impurities such as catalyst are removed by rotary evaporation. After removing D3F and silane coupling agent by vacuum distillation, a colorless and transparent viscous liquid is obtained, which is fluorinated silicone oil.

[0062] Example 3:

[0063] Weigh 10.000g D3F (21.34mmol), 0.883g (3.77mmol) silane coupling agent and 0.942g catalyst. Mix D3F, catalyst and 0.5g distilled water in a three-necked flask. Stir mechanically and reflux at 120℃ for one hour. Then add silane coupling agent and the remaining catalyst. Stir mechanically and reflux at 130℃ for two hours.

[0064] After the reaction is complete, the reaction product is placed in a single-necked flask, and impurities such as catalyst are removed by rotary evaporation. After removing D3F and silane coupling agent by vacuum distillation, a colorless and transparent viscous liquid is obtained, which is fluorinated silicone oil.

[0065] Example 4:

[0066] Weigh 10.000g D3F (21.34mmol), 1.667g (7.11mmol) silane coupling agent and 0.942g catalyst. Mix D3F, catalyst and 0.5g distilled water in a three-necked flask. Stir mechanically and reflux at 120℃ for 1h. Then add silane coupling agent and the remaining catalyst. Stir mechanically and reflux at 130℃ for 2h.

[0067] After the reaction is complete, the reaction product is placed in a single-necked flask, and impurities such as catalyst are removed by rotary evaporation. After removing D3F and silane coupling agent by vacuum distillation, a colorless and transparent viscous liquid is obtained, which is fluorinated silicone oil.

[0068] Example 5:

[0069] Weigh 10.000g D3F (21.34mmol), 2.144g (9.15mmol) silane coupling agent and 0.942g catalyst. Mix D3F, catalyst and 0.5g distilled water in a three-necked flask. Stir mechanically and reflux at 120℃ for one hour. Then add silane coupling agent and the remaining catalyst. Stir mechanically and reflux at 130℃ for two hours.

[0070] After the reaction is complete, the reaction product is placed in a single-necked flask, and impurities such as catalyst are removed by rotary evaporation. After removing D3F and silane coupling agent by vacuum distillation, a colorless and transparent viscous liquid is obtained, which is fluorinated silicone oil.

[0071] Example 6:

[0072] Weigh 10.000g D3F (21.34mmol), 0.0278g (0.12mmol) silane coupling agent and 0.942g catalyst. Mix D3F, catalyst and 0.5g distilled water in a three-necked flask. Stir mechanically and reflux at 120℃ for one hour. Then add silane coupling agent and the remaining catalyst. Stir mechanically and reflux at 130℃ for two hours.

[0073] After the reaction is complete, the reaction product is placed in a single-necked flask, and impurities such as catalyst are removed by rotary evaporation. After removing D3F and silane coupling agent by vacuum distillation, a colorless and transparent viscous liquid is obtained, which is fluorinated silicone oil.

[0074] Example 7:

[0075] Weigh 10.000g D3F (21.34mmol), 2.693g (11.49mmol) silane coupling agent and 0.942g catalyst. Mix D3F, catalyst and 0.5g distilled water in a three-necked flask. Stir mechanically and reflux at 120℃ for one hour. Then add silane coupling agent and the remaining catalyst. Stir mechanically and reflux at 130℃ for two hours.

[0076] After the reaction is complete, the reaction product is placed in a single-necked flask, and impurities such as catalyst are removed by rotary evaporation. After removing D3F and silane coupling agent by vacuum distillation, a colorless and transparent viscous liquid is obtained, which is fluorinated silicone oil.

[0077] Example 8:

[0078] Weigh 10.000g D3F (21.34mmol), 3.335g (14.23mmol) silane coupling agent and 0.942g catalyst. Mix D3F, catalyst and 0.5g distilled water in a three-necked flask. Stir mechanically and reflux at 120℃ for one hour. Then add silane coupling agent and the remaining catalyst. Stir mechanically and reflux at 130℃ for two hours.

[0079] After the reaction is complete, the reaction product is placed in a single-necked flask, and impurities such as catalyst are removed by rotary evaporation. After removing D3F and silane coupling agent by vacuum distillation, a colorless and transparent viscous liquid is obtained, which is fluorinated silicone oil.

[0080] Example 9:

[0081] The process of coating and modifying base fabric materials with fluorinated silicone oil is as follows:

[0082] First, 2g of the synthesized fluorinated silicone oil was placed in a 50mL beaker, along with 15mL of tetrahydrofuran solution and 0.10g of DMPA photoinitiator, and allowed to dissolve completely. Then, a suitable amount of base fabric was taken, cut to the appropriate size, and immersed in the fluorinated silicone oil solution for 2 hours to ensure complete saturation. After removal, the fabric was irradiated with a UV lamp for 1 hour to initiate the reaction. Next, the impregnated base fabric was placed in a vacuum drying oven and dried at 80℃ for approximately 1 hour, then irradiated again with a UV lamp for 1 hour. Finally, the sample was removed and air-dried in a fume hood, thus completing the coating and modification of the base fabric with fluorinated silicone oil.

[0083] Comparative Example 1:

[0084] 15.000g of D4 (50.57mmol), 10.000g of D3F (21.34mmol), and 3.520g of NKC-9 after acid activation were weighed and mixed in a 100mL three-necked flask. Polymerization was carried out at 80℃ for 8h, and then 0.359g of tetramethyldivinyldisiloxane was added to continue the reaction for 1.5h. Cyclohexane was then added to dissolve the catalyst, and the supernatant was removed by filtration. The supernatant was then removed from the low-boiling point at 200℃ / 0.09MPa for 3h to obtain a high-viscosity fluorinated silicone oil.

[0085] Comparative Example 2:

[0086] Weigh a certain amount of adipic acid (AA) and polyetheramine and add them to a three-necked flask. After the stirring device and reflux condenser are installed, start stirring and heat to 170-180℃. Add the catalyst sodium hypophosphite and the antioxidant triphenyl phosphite. Continue to heat to 190-220℃ and keep the reaction at this temperature for 2-3 hours. The product obtained is the amide intermediate PHAM.

[0087] Take a certain amount of D4, D3F and MTMS and add them to a three-necked flask. After the stirring device and reflux condenser are installed, start stirring. When the temperature rises to 60-70℃, add the catalyst. Then raise the temperature to 95-105℃ and keep the reaction at this temperature for 5-7 hours. The product obtained is terminal epoxy-containing fluorinated polysiloxane EPFSO.

[0088] A certain amount of PHAM was dissolved in isopropanol and added to a three-necked flask. A certain amount of EPFSO was then added. After the stirring and reflux condenser were installed, the stirring was started and the temperature was raised to 72-80℃. The reaction was maintained at this temperature for 2-4 hours. After vacuum filtration, appropriate amounts of acetic acid, emulsifiers 1305 and 1308 were added to the obtained product. A suitable amount of water was slowly added and the mixture was stirred thoroughly and evenly to obtain the final product, fluorinated silicone oil.

[0089] Comparative Example 3:

[0090] Add 500g of D3F to a four-necked flask equipped with a thermometer and stirrer, heat to 50℃ for 2 hours to dehydrate, then add 60g of end-capping agent and 0.5% (2.8g) of catalyst by mass of the material, keep the reaction at 40℃ for 1 hour, add 0.9g of sodium carbonate to neutralize for 3-4 hours, after which the temperature is raised to 140℃ and vacuum dehydrate for 2 hours, filter to obtain fluorinated silicone oil.

[0091] Comparative Example 4:

[0092] Add 400g D3F, 100g acetone, 40g distilled water, and 8g tungstic phosphoric acid sequentially to a three-necked flask equipped with a spherical condenser and a mechanical stirrer. Slowly raise the temperature to 60°C. After liquid reflux is observed in the spherical condenser, react at 60–64°C for 5 hours. Then, lower the temperature to room temperature, add a small amount of magnesium oxide and diatomaceous earth, filter, and wash the filter cake with acetone. Collect the filtrate and evaporate the acetone. Then, raise the temperature to 120°C, adjust the pressure to 1.333 kPa, remove low-boiling substances, and obtain a clear and transparent product, which is fluorinated silicone oil.

[0093] Comparative Example 5:

[0094] The process of impregnating and modifying the base fabric material with the fluorinated silicone oils prepared in Comparative Examples 1-4 is as follows:

[0095] First, take 2g of the fluorinated silicone oil synthesized in Comparative Examples 1-4 and place it in a 50mL beaker. Add 5mL of tetrahydrofuran solution and 0.12g of DMPA photoinitiator, and ensure they are fully dissolved. Then, take an appropriate amount of base fabric, cut it to a suitable size with scissors, and soak it in the fluorinated silicone oil solution for 2 hours to ensure complete saturation. After removal, irradiate with a UV lamp for 1 hour to initiate the reaction. Next, place the impregnated base fabric in a vacuum drying oven and dry it at 80℃ for about 1 hour. After removal, irradiate it again with a UV lamp for 1 hour. Finally, remove the sample and air dry it in a fume hood, thus completing the coating and modification of the base fabric with fluorinated silicone oil.

[0096] The modified base fabric also has a good feel, but the surface hydrophilicity and hydrophobicity have not changed. Therefore, the fluorinated silicone oil in Comparative Examples 1-4 is difficult to modify the hydrophilic base fabric material and it is difficult to achieve the hydrophobic effect of the material.

[0097] Experimental Example 1:

[0098] The fluorinated silicone oil-coated and modified base fabric materials obtained in Example 9 were tested, and elemental analysis was performed on the products, as shown in Table 1. A clear solid layer of fluorinated silicone oil was formed on the coated base fabric, indicating that the fluorinated silicone oil was successfully cured on the base fabric surface. Table 1 shows that the untreated base fabric contained no F and Si, while after coating, F and Si appeared on the base fabric surface, with a fluorine content of 12.94% and a silicon content of 13.49%. Compared to the untreated base fabric, coating allows the fluorinated silicone oil to have polymer coating on each fiber surface of the base fabric, forming a new surface configuration with a "mushroom-like" structure. This rough configuration allows for a stronger coating of the fluorinated polymer, thus enhancing hydrophobicity. This further confirms that the increased heat resistance and hydrophobicity of the base fabric due to the fluorinated silicone oil are brought about by the coating process.

[0099] Table 1 Elemental Analysis

[0100]

[0101] Experimental Example 2:

[0102] The product obtained in Example 9, fluorinated silicone oil-coated and modified base fabric, was tested. The dispersibility of collagen fibers in the fluorinated silicone oil-modified base fabric was assessed. Figure 4 As shown. Figure 4 These are scanning electron microscope (SEM) images of the base fabric before and after coating. The left side shows the uncoated fabric; before coating, the collagen fibers are connected by numerous functional groups, leading to adhesion and poor dispersion due to lack of filling and reactions between surface groups. After coating, the collagen fibers are filled with fluorinated silicone oil, and the hydroxyl and carboxyl groups on the collagen fiber surface react with the fluorinated silicone oil, making adhesion less likely and forming a relatively stable modified collagen structure. Figure 4 As can be clearly seen in the figure below, the modified collagen fiber has a better dispersion effect, with no large amount of adhesion between the fibers. In addition, from the perspective of feel, it has a softer and fuller feel, and its mechanical properties are also superior.

[0103] Experimental Example 3:

[0104] Thermogravimetric analysis was performed on the fluorinated silicone oil-coated and modified base fabric materials obtained in Example 9 to investigate the synthesis reactions of silane coupling agents KH570 and D3F, and their interactions with other substances. Figure 5 As shown, the thermal stability of the synthesized fluorinated silicone oil was detected using a thermogravimetric analyzer. In the experiment, the temperature was set between 30℃ and 780℃, and the experimental results were analyzed based on the thermogravimetric analyzer graphs. The graphs show that when the weight loss is 10%, the corresponding weight loss temperature is 437.5℃, the fastest weight loss temperature is 524.6℃, and the fluorinated silicone oil completely loses weight at 637.5℃. Therefore, studying the synthesis reaction of silane coupling agents KH570 and D3F and the thermal stability of fluorinated silicone oil has significant theoretical and practical application value.

[0105] Experimental Example 4:

[0106] The hydrophobic properties of the base fabric materials before and after coating and modification were tested in Example 9 and the blank base fabric material, such as... Figure 6As shown, the hydrophobicity of the blank base fabric and the fluorinated silicone oil-modified base fabric from Example 9 were measured. It can be seen that the contact angle of the base fabric is 126.2 degrees, greater than 90 degrees, indicating that the surface of the untreated base fabric has good hydrophobic properties. The contact angle of the synthesized fluorinated silicone oil is 133.6 degrees, greater than 90 degrees and greater than the 126.2 degrees of the untreated base fabric, indicating that the synthesized fluorinated silicone oil has good hydrophobic properties. Based on the contact angle measured by the optical contact angle meter, it can be seen that the fluorinated silicone oil can improve the hydrophobicity of the base fabric.

[0107] The content of this invention is not limited to the embodiments listed. Any equivalent modifications made by those skilled in the art to the technical solutions of this invention after reading this specification are covered by the claims of this invention.

Claims

1. Application of UV-curable fluorosilicone coating material in leather finishing agents, wherein the UV-curable fluorosilicone coating material is obtained by a catalyst-catalyzed reaction of D3F and a silane coupling agent; the UV-curable fluorosilicone coating material is prepared by the following steps: D3F, a portion of the catalyst and water are refluxed at 100℃-130℃ for 0.5 h-2 h with stirring, then the silane coupling agent and the remaining catalyst are added, and the mixture is stirred and refluxed at 120℃-140℃ for 2 h-3 h; after the reaction is completed, the catalyst is removed by evaporation, and D3F and the silane coupling agent are removed by vacuum distillation to obtain the UV-curable fluorosilicone coating material; wherein the silane coupling agent is γ-methacryloyloxypropyltrimethoxysilane, and the molar ratio of D3F to the silane coupling agent is (7-9):(3-1).

2. The application according to claim 1, characterized in that, The catalyst is an alkaline compound.

3. A method for modifying raw leather, comprising applying a UV-curable fluorosilicone coating material as described in claim 1 to modify the raw leather material.

4. The method for modifying raw leather according to claim 3, characterized in that, The steps include the following: The raw hide material is cut into appropriate sizes and immersed in a UV-curable fluorosilicone coating material solution to ensure full saturation. After removal, it is cured with a UV lamp, then vacuum dried, irradiated with a UV lamp again, and finally air-dried. The reaction is then complete, thus completing the modification of the raw hide material by the UV-curable fluorosilicone coating material.

5. The method for modifying raw leather according to claim 4, characterized in that, The raw hide material was immersed in UV-cured fluorosilicone coating material for 2 hours.

6. The method for modifying raw leather hides according to claim 4, characterized in that, The solvent used in the UV-curable fluorosilicone coating material solution is tetrahydrofuran; before immersion, a photoinitiator is added to the UV-curable fluorosilicone coating material solution.

7. A modified raw hide, characterized in that, The modified raw hide is obtained by coating and modifying the raw hide material with the UV-curable fluorosilicone coating material described in claim 1.

8. The modified raw hide according to claim 7, characterized in that, In modified raw hides, the mass content of fluorinated silicone oil is 0.2%-20%.

9. The application of the modified raw hide as described in claim 8 in the leather industry.

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