Waterproof anti-siphon double-faced leather and processing technology thereof

Abstract

The invention relates to the technical field of double-face leather processing, and particularly discloses waterproof anti-siphon double-face leather and a processing technology thereof. The invention discloses a processing technology of waterproof and anti-siphon double-faced leather. The processing technology comprises the following processing steps: sequentially performing soaking, re-soaking, degreasing, pickling, tanning, filling, washing, re-filling, re-tanning, dyeing, waterproof and anti-siphon treatment, drying finishing and surface coating on fur. The waterproof and anti-siphon treatment specifically comprises the following steps: washing the fur with water, neutralizing, adding a compound waterproof agent, rotating, fixing and throwing water; the compound waterproof agent comprises a dispersing agent Tamm NA, sodium carbonate, a dispersing agent Tamm M, waterproof oil and a fluoride-free waterproof agent. According to the waterproof anti-siphon double-faced leather, the static water absorption rate and the dynamic water absorption rate of the waterproof anti-siphon double-faced leather are 27.2% and 17.0% at least, the waterproof anti-siphon double-faced leather has high waterproofness, the water climbing height is 0.5 cm at least during anti-siphon detection, the waterproof anti-siphon double-faced leather has high anti-siphon performance, and the waterproof anti-siphon performance of the double-faced leather is improved.

Description

Technical Field

[0001] The present application relates to the technical field of leather processing, and more specifically, to a waterproof and anti-siphoning fur leather and a processing technology thereof. Background Art

[0002] Fur leather, also known as fur or fur, refers to a leather product with one fur side and the other side being leather. It has both the texture of leather and the decorative effect of hair. With the continuous expansion of the application field of fur leather fabrics, it has been used in shoe uppers everywhere, making the shoe uppers both warm and breathable. However, for shoe uppers, fur leather will inevitably get wet due to contact with water in various occasions. Due to the tiny pores in fur leather, water can easily penetrate, and the hair contains hydrophilic protein, which can easily absorb water and retain it, forming a capillary phenomenon in places where the hair is dense, accelerating the diffusion of water, resulting in the fur leather not having a waterproof function, affecting the comfort and warmth of the shoes, and also increasing the weight of the shoes.

[0003] In the related art, in order to make the wool leather waterproof, a waterproofing agent is applied to the wool leather during dipping and rolling, and then the leather is baked at a high temperature of more than 140°C to solidify the waterproofing agent on the wool fibers. Although this has a certain waterproof effect, it will make the wool surface of the leather turn yellow, and the leather surface will shrink easily, affecting the texture of the leather, making it difficult to meet actual use needs. Summary of the invention

[0004] In order to improve the waterproof and anti-siphoning performance of fur leather, the present application provides a waterproof and anti-siphoning fur leather and a processing technology thereof.

[0005] In a first aspect, the present application provides a processing technology for waterproof and anti-siphoning fur leather, which adopts the following technical solution: A processing technology for waterproof and siphon-proof fur leather, the processing technology comprises the following processing steps: soaking the fur in water, re-immersing it in water, degreasing, pickling, tanning, filling, washing, filling, retanning and dyeing, waterproof and siphon-proof treatment, drying and finishing, and surface finishing. The waterproof and siphon-proof treatment is specifically as follows: washing after the filling, retanning and dyeing, then adding water at 48-52°C to neutralize it, then adding a compound waterproofing agent, rotating it, fixing it, and then entering the drying and finishing process after shaking off the water. The compound waterproofing agent is prepared by adding 0.8-1.2 g of dispersant Tam NA, 0.8-1.2 g of soda ash, 0.07-0.09 g of dispersant Tam M, 2-3 g of waterproofing oil and 2-3 g of fluorine-free waterproofing agent into each liter of water.

[0006] The fur in the present application can be selected from any one of wool, horse, fox, rabbit or mink. The waterproof oil can be selected from any one or more of beeswax, palm wax, silicone polymer, fluorinated resin, acrylate, and polyurethane.

[0007] By adopting the above technical scheme, the anti-siphon function of the fur leather is to prevent the capillary action from penetrating into the interior along the fiber gap by treatment. The siphon phenomenon is mainly caused by the hydrophilicity of the fiber and the capillary structure. In the waterproof and anti-siphon treatment step, waterproof oil is used to treat the fur. The waterproof oil can penetrate into the fiber gap, cool and solidify to form a physical hydrophobic film or spread on the fiber surface to form a flexible film with low surface energy, thereby blocking the capillary water absorption path to prevent the fiber from absorbing water; in addition, the waterproof oil can penetrate into the micropores between the fibers, reduce the size of the gaps, and reduce the capillary pressure that drives the liquid to penetrate, thereby slowing down the siphon speed of the fur leather and improving the waterproof and anti-siphon performance of the fur leather. At the same time, a fluorine-free waterproofing agent is used to treat the fur. Compared with a fluorocarbon waterproofing agent, a fluorine-free waterproofing agent can reduce the pollution to water bodies, soil, and the environment, as well as its harm to human health. It constructs a stable hydrophobic layer on the fiber surface, reduces water adsorption, and reduces the hydrophilicity of the fiber, thereby improving the waterproof and anti-siphon performance of the fur leather. And most fluorine-free waterproofing agents will not completely close the leather pores, and are more breathable than some fluorocarbon agents, which can ensure the breathability of the fur leather. Treating fur with waterproof oil and fluorine-free waterproof agent together can not only fill the macroscopic pores, but also cover the microscopic fibers to achieve multi-scale anti-siphoning, thereby further improving the waterproof and anti-siphoning properties of fur leather.

[0008] The waterproof and anti-siphon treatment is carried out after filling, retanning, dyeing and before drying and finishing, which can not only improve the waterproof and anti-siphon performance of fur leather, but the waterproof and anti-siphon treatment of this application is an independent waterproof operation and is applicable to various leather materials. In addition, neutralization is first performed during the waterproof and anti-siphon treatment, which is conducive to the combination of the compound waterproof agent and fur, and enhances the bonding strength between the compound waterproof agent and fur. Furthermore, the amount of waterproof oil needs to be controlled during the treatment to avoid excessive waterproof oil clogging the leather pores, causing the leather to harden or the fur to adhere and harden.

[0009] In addition, the dispersant Tam NA in the compound waterproofing agent can decompose the hydrophobic dirt such as grease, dust, blood stains on the surface of the fur leather, which can prevent the hydrophobic dirt from hindering the waterproofing agent from penetrating into the fur. In addition, the addition of dispersant Tam NA can also disperse the tanning agent and dye particles remaining in the previous process to avoid plaques during waterproofing. On the one hand, soda ash can ensure the flexibility of the fur leather and assist the dispersant Tam NA to enhance the decontamination effect. On the other hand, soda ash and dispersant Tam NA can reduce surface tension, increase pores, open the fiber network, and facilitate the penetration of waterproof oil and fluorine-free waterproofing agent into the fiber. Soda ash can also adjust the pH to facilitate the uniform adhesion of raw materials such as waterproof oil and fluorine-free waterproofing agent in the compound waterproofing agent on the surface of the fur leather, thereby improving the waterproofing effect.

[0010] Dispersant Tam M can be used in conjunction with dispersant Tam NA to achieve full spectrum removal of polar and non-polar dirt, providing a clean fiber surface for waterproof oils and fluorine-free waterproofing agents. Both can also increase fiber porosity, increase the penetration depth of waterproof oils and fluorine-free waterproofing agents, improve the stable dispersion of waterproof oils and fluorine-free waterproofing agents, and improve the waterproof and anti-siphoning properties of leather.

[0011] Preferably, the step of adding the compound waterproofing agent is as follows: first add dispersant Tam NA and soda ash and rotate for 35-45 minutes, then add dispersant Tam M and rotate for 35-45 minutes, and finally add waterproofing oil and fluorine-free waterproofing agent and rotate for 140-160 minutes.

[0012] By adopting the above technical scheme, adjusting the order of adding the raw materials of the compound waterproofing agent and the rotation time after adding the raw materials, it is beneficial for the waterproof and anti-siphoning components to be adsorbed on the fur surface, thereby further improving the waterproof and anti-siphoning performance of the fur leather.

[0013] Preferably, the fluorine-free waterproofing agent in the compound waterproofing agent is selected from at least one of fluorine-free waterproofing agent TPY, modified silicone oil, silicone resin, long-chain alkane, paraffin and palm wax.

[0014] The compound waterproofing agent of the present application can select at least one of fluorine-free waterproofing agent TPY, modified silicone oil, silicone resin, long-chain alkane, paraffin, and palm wax, and when any one or more of modified silicone oil, silicone resin, long-chain alkane, paraffin, and palm wax are selected, the waterproof and anti-siphoning properties of wool leather can be improved.

[0015] Preferably, the modified silicone oil is prepared by the following steps: S1, dehydrating the hydroxyl-terminated polydimethylsiloxane under reduced pressure at 100-120° C. for 1-2 h, adding tetrahydrofuran and mixing, adding hexamethylene diisocyanate, dropping dibutyltin dilaurate, reacting under magnetic stirring at 50-70° C. for 2-4 h, cooling, and distilling under reduced pressure to obtain pretreated hydroxyl-terminated polydimethylsiloxane; S2, adding γ-aminopropyltriethoxysilane to water, adding acetic acid to adjust the pH to 4-5, stirring at 23±2° C. for 2-4 hours, neutralizing, and obtaining hydrolyzed γ-aminopropyltriethoxysilane; S3. Under nitrogen protection, the pretreated hydroxyl-terminated polydimethylsiloxane and the hydrolyzed γ-aminopropyltriethoxysilane are mixed at 80-120° C. for 2-6 hours, tetramethylammonium hydroxide and an antioxidant are added, stirred at 80-90° C. under nitrogen protection for 4-6 hours, vacuum dehydrated, adjusted to pH 6-7, filtered, and amino-modified silicone oil is obtained.

[0016] The mass ratio of the hydroxyl-terminated polydimethylsiloxane to tetrahydrofuran is 1:(2-4); the dibutyltin dilaurate is 0.05-0.1% of the mass of the hydroxyl-terminated polydimethylsiloxane; the hexamethylene diisocyanate is 1:(2-2.2) of the mass of the hydroxyl-terminated polydimethylsiloxane; the mass ratio of the γ-aminopropyltriethoxysilane to water is 1:(2.5-3.5). The amount of tetramethylammonium hydroxide is 0.01-0.05% of the total mass of the pretreated hydroxyl-terminated polydimethylsiloxane and the hydrolyzed γ-aminopropyltriethoxysilane; and the antioxidant is 0.1-0.5% of the mass of the pretreated hydroxyl-terminated polydimethylsiloxane.

[0017] By adopting the above technical scheme, γ-aminopropyltriethoxysilane is selected to modify hydroxy-terminated polydimethylsiloxane, in which the amino group forms an ionic bond with the carboxyl group of collagen in the leather, thereby improving the binding force between the fluorine-free waterproofing agent, i.e., the modified silicone oil, and the leather, and having high wash resistance, thereby improving the waterproofness and waterproof durability of the leather.

[0018] Moreover, the present application first uses hexamethylene diisocyanate to treat and activate the hydroxyl-terminated polydimethylsiloxane, which is more conducive to the subsequent reaction with the amino functional group and has a higher grafting efficiency.

[0019] Preferably, the mass ratio of the hydrolyzed γ-aminopropyltriethoxysilane to the hydroxyl-terminated polydimethylsiloxane is 1:(8-12).

[0020] By adopting the above technical scheme and adjusting the mass ratio of the hydrolyzed γ-aminopropyltriethoxysilane to the hydroxyl-terminated polydimethylsiloxane, the modification effect of the amino-modified silicone oil can be further improved, thereby improving the waterproof and anti-siphoning properties of the amino-modified silicone oil.

[0021] Preferably, after the hydroxyl-terminated polydimethylsiloxane is mixed with the hydrolyzed γ-aminopropyltriethoxysilane, long-chain alkyl silicone oil is added; the mass ratio of the long-chain alkyl silicone oil to the hydroxyl-terminated polydimethylsiloxane is 1:(5-7).

[0022] By adopting the above technical scheme, long-chain alkyl silicone oil is mixed with hydroxyl-terminated polydimethylsiloxane and γ-aminopropyltriethoxysilane, so as to further improve the hydrophobicity, adhesion and durability of amino-modified silicone oil, thereby further improving the waterproof and anti-siphoning properties of leather.

[0023] Preferably, the fixing in the waterproof and anti-siphoning treatment step is specifically as follows: placing the fur in 45-55°C water, adding formic acid and rotating for 25-35 minutes and adjusting the pH to 3.5, and then adding aluminum tannin and rotating for 55-65 minutes.

[0024] The dosage of formic acid and aluminum tannin is 0.8-1.2 g per liter of water.

[0025] By adopting the above technical solution, formic acid is added during fixation, which can undergo a cross-linking reaction with the active groups in the compound waterproofing agent to form a stable three-dimensional network structure, further enhancing the waterproofness of the leather. Aluminum tannin can further reduce surface energy and enhance hydrophobicity, thereby improving the waterproofness of the leather.

[0026] In a second aspect, the present application provides a waterproof and anti-siphon leather produced by any of the above-mentioned processing techniques for waterproof and anti-siphon leather.

[0027] In summary, the present application includes at least one of the following beneficial technical effects: (1) The present application controls the type and dosage of the compound waterproofing agent for waterproofing and anti-siphoning treatment, as well as the order of addition and the rotation time, so that the static water absorption rate and dynamic water absorption rate of the waterproof and anti-siphoning leather are 33.2% and 19.2%, and the water climbing height during the anti-siphoning test is 0.8 cm, thereby improving the waterproof and anti-siphoning performance of the leather.

[0028] (2) In the present application, by selecting homemade amino-modified silicone oil as the fluorine-free waterproofing agent in the compound waterproofing agent in the waterproofing and anti-siphoning treatment step, the static water absorption rate and dynamic water absorption rate of the waterproof and anti-siphoning leather are 28.6%-30.0% and 17.2%-17.5%, and the water climbing height during the anti-siphoning test is 0.6 cm, thereby further improving the waterproof and anti-siphoning performance of the leather.

[0029] (3) The present application optimizes the curing steps, adds formic acid during the curing process, and adds aluminum tannin, so that the static water absorption rate and dynamic water absorption rate of the waterproof and anti-siphoning leather are 27.2% and 17.0%, and the water climbing height during the anti-siphoning test is 0.5 cm, thereby further improving the waterproof and anti-siphoning performance of the leather. DETAILED DESCRIPTION

[0030] The present application is further described in detail below in conjunction with specific embodiments.

[0031] The types and sources of various chemical materials in the wool leather processing technology of this application are as follows: the soaking agent is purchased from Cromo of Spain, model AS-21; the fungicide is purchased from Dow of the United States, model 830; the surfactant is purchased from Kekai Company, model MH2; the degreaser is purchased from Dawe Company, model HKM; the soaking agent is purchased from Cromo of Spain, model AS-21; the chrome-free tanning agent TWS is purchased from Sichuan Tingjiang New Materials Co., Ltd.; the fatliquor SC-4 is purchased from Cromo; the chrome-aluminum tanning agent is purchased from Desail; the melamine retanning agent is purchased from BASF, model DLF; the degreaser 45 is purchased from Aoxiang Company; the degreaser ML / N is purchased from Kekai Company; the tanning agent FAN is purchased from Beijing Panbo Technology Co., Ltd.; the filler FD is purchased from Beijing Panbo Technology Co., Ltd.; the acrylic retanning agent FS is purchased from Beijing Panbo Technology Co., Ltd.; the penetrant JFC is purchased from Wuhan Jiyesheng Chemical Co., Ltd.

[0032] The following is an example of the preparation of modified silicone oil Preparation Example 1 The modified silicone oil of Preparation Example 1 was prepared by the following steps: S1. Dehydrate 1 kg of hydroxyl-terminated polydimethylsiloxane (viscosity 60-70) under reduced pressure at 110° C. for 1.5 h, add 3 L of tetrahydrofuran and mix, add 500 g of hexamethylene diisocyanate, dropwise add 1 g of dibutyltin dilaurate (tin content is 18.2±0.2%), react at 60° C. under 400 rpm magnetic stirring for 3 h, cool, and distill under reduced pressure to obtain pretreated hydroxyl-terminated polydimethylsiloxane; S2, add 1 kg of γ-aminopropyltriethoxysilane to 3 L of water, add acetic acid to adjust the pH to 4, stir at 23 ° C for 3 hours, neutralize to pH 7-8, and obtain hydrolyzed γ-aminopropyltriethoxysilane; S3. Under nitrogen protection, 6 kg of pretreated hydroxyl-terminated polydimethylsiloxane was mixed with 1 kg of hydrolyzed γ-aminopropyltriethoxysilane, 0.35 g of tetramethylammonium hydroxide and 0.03 kg of antioxidant (antioxidant 1010) were added, and the mixture was stirred at 85 ° C. under nitrogen protection for 5 h. Vacuum dehydration was performed, the pH was adjusted to 6-7, and the mixture was filtered to obtain amino-modified silicone oil.

[0033] Preparation Example 2 The modified silicone oil of Preparation Example 2 was prepared by the following steps: Steps S1 and S2 were the same as those of Preparation Example 1, and S3 was to mix 6 kg of hydroxyl-terminated polydimethylsiloxane, 1.5 kg of long-chain alkyl silicone oil and 1 kg of hydrolyzed γ-aminopropyltriethoxysilane under nitrogen protection, add 0.21 g of tetramethylammonium hydroxide and an antioxidant, stir at 85 ° C. under nitrogen protection for 5 h, vacuum dehydrate, adjust the pH to 7, filter, and obtain amino-modified silicone oil.

[0034] Preparation Example 3-6 The preparation methods of the modified silicone oils of Preparation Examples 3-6 are the same as those of Preparation Example 2, except that the amounts of long-chain alkyl silicone oils used are different, namely 1.2 kg, 1 kg, 0.85 kg and 0.75 kg, respectively. The types and amounts of other raw materials are the same as those of Preparation Example 2.

[0035] Example 1 The processing technology of the waterproof and anti-siphoning fur leather of Example 1 comprises the following steps: Soaking: Place the wool skin in 25℃ water at a material-liquid ratio of 1:19, add 0.4g / L soaking agent, 0.2g / L fungicide and 2g / L surfactant, rotate for 15min, soak for 12h overnight, row intermittently, and peel the skin the next day; Re-immersion: Place the wool skin in 30℃ water at a material-liquid ratio of 1:13, add 0.4g / L soda ash, 0.4g / L degreasing enzyme, 0.2g / L soaking agent and 0.7g / L surfactant, rotate for 25min, let stand overnight, and remove the flesh the next day; Degreasing: add the re-soaked fur to 45℃ water at a material-liquid ratio of 1:60, then add 1.16g / L soda ash, 4.7g / L degreasing agent 45, 1.67g / L degreasing agent ML / N, rotate for 110min, and wash the fur with water; Pickling: add the degreased fur to 30℃ water, 6.0 Baume industrial salt, 3g / L 85% formic acid at a material-liquid ratio of 1:15, rotate for 55min, and let stand for 12h; add 2g / L 90% sulfuric acid, adjust the pH to 3.0, let stand for 6h, and remove the skin; Chrome tanning: add the pickled fur to 32℃ water at a material-liquid ratio of 1:15, add 45g / L sodium chloride, 3g / L fatliquor SC-4, rotate for 20min, add 0.3mL / L formic acid and 3g / L chromium-aluminum tanning agent, rotate for 10min, add 6g / L chrome powder and 3g / L melamine retanning agent, rotate for 40min, add 6g / L chrome powder, rotate for 90min, add 0.5g / L sodium formate, rotate for 20min, let stand for 30min, remove the skin, mount, and let stand for 2 days; Filling: Add the tanned fur to 40℃ water at a material-liquid ratio of 1:15, add 2g / L tanning agent FAN, 3g / L filler FD and 1g / L acrylic acid retanning agent FS, rotate for 40min, add 0.5mL / L formic acid, and rotate for 20min; Washing: Wash the stuffed fur in water at 40°C for 5 minutes; Refilling: Same as filling steps; Retanning: Same as tanning steps Dyeing: Add the tanned fur to 60℃ water at a material-liquid ratio of 1:15, add 5g / L penetrant JFC and rotate for 30min, add 5g / L dye (acid yellow G) and rotate for 60min, add 0.4g / L formic acid and rotate for 20min, then add 0.4g / L formic acid and rotate for 20min, adjust the pH to 4, and make the fur evenly colored; Waterproof and anti-siphon treatment: wash the fur with water, neutralize it in 50°C water, then add 1g / L dispersant Tam NA (purchased from Starr), 1g / L soda ash (particle size is 300 mesh), 0.08g / L dispersant Tam M (purchased from Starr), 2.5g / L waterproof oil HP (purchased from Starr), 2.5g / L fluorine-free waterproof agent TPY (purchased from Argo), rotate for 150 minutes, place it in 50°C water, add formic acid and rotate for 30 minutes and adjust the pH to 3.5, shake off the water and enter the drying and finishing process.

[0036] Drying and finishing: first spread the dyed fur flat on an absorbent towel, gently roll it up and press it to absorb surface moisture, then dry it at 35°C for 3 hours, comb the fur lightly with a fine-tooth comb or a soft brush, and after surface coating, you will get waterproof and anti-siphoning fur leather.

[0037] Example 2 The difference between the processing technology of the waterproof and anti-siphoning leather in Example 2 and Example 1 lies in the different waterproof and anti-siphoning treatment steps. Specifically, the fur is washed with water, neutralized in 50°C water, and then 1g / L dispersant Tam NA and 1g / L soda ash are added and rotated for 40 minutes, and then 0.08g / L dispersant Tam M is added and rotated for 40 minutes, and finally 2.5g / L waterproof oil HP and 2.5g / L fluorine-free waterproofing agent TPY are added and rotated for 150 minutes. The rest of the operations are the same as in Example 1.

[0038] Example 3 The difference between the processing technology of the waterproof and anti-siphoning leather in Example 3 and Example 2 is that the fluorine-free waterproofing agent in the waterproof and anti-siphoning treatment step is modified silicone oil, and the modified silicone oil is polyether modified silicone oil. The remaining steps and raw material selection are the same as in Example 2.

[0039] Embodiment 4-9 The difference between the processing technology of waterproof and anti-siphoning leather in Example 4-9 and Example 3 is that the fluorine-free waterproofing agent in the waterproof and anti-siphoning treatment step is the modified silicone oil prepared in Preparation Example 1-6, and the remaining steps and raw materials are the same as in Example 3.

[0040] Example 10 The difference between the processing technology of the waterproof and anti-siphoning leather in Example 10 and Example 7 is that the curing in the waterproof and anti-siphoning treatment step is specifically to place the fur in 50°C water, add 1g / L formic acid, rotate for 30 minutes and adjust the pH to 3.5, then add 1g / L aluminum tannin ALF and rotate for 60 minutes, and the remaining steps and raw material selection are the same as in Example 7.

[0041] Comparative Example 1 The processing technology of the waterproof and anti-siphoning leather in Comparative Example 1 differs from that in Example 1 in that no dispersant Tam NA is added to the compound waterproofing agent in the waterproof and anti-siphoning treatment, and the remaining steps are the same as in Example 1.

[0042] Comparative Example 2 The processing technology of the waterproof and anti-siphoning leather in Comparative Example 2 differs from that in Example 1 in that the dispersant Tam M is not added to the compound waterproofing agent in the waterproof and anti-siphoning treatment, and the remaining steps are the same as those in Example 1.

[0043] Comparative Example 3 The processing technology of the waterproof and anti-siphoning leather of Comparative Example 3 differs from that of Example 1 in that in the waterproof and anti-siphoning treatment, an equal amount of the oil-repellent agent HP in the compound waterproofing agent is replaced with a fluorine-free waterproofing agent TPY, and the remaining steps are the same as those of Example 1.

[0044] Comparative Example 4 The processing technology of the waterproof and anti-siphoning leather of Comparative Example 4 differs from that of Example 1 in that the fluorine-free waterproofing agent TPY in the compound waterproofing agent is replaced by an equal amount of the oil-proofing agent HP in the waterproof and anti-siphoning treatment, and the remaining steps are the same as those of Example 1.

[0045] Comparative Example 5 The processing technology of the waterproof and anti-siphoning leather of Comparative Example 5 differs from that of Example 1 in the chrome-free tanning, specifically: the liquid ratio is controlled to be 1:17, 5.5 degrees Baume industrial salt, 13 g / L chrome-free tanning agent TWS are added, 0.5 g / L soda ash is added to adjust the pH to 4.5, rotate for 170 minutes, stop for 25 minutes, rotate for 50 minutes, and stop for 230 minutes; soda ash is added at a rate of 0.5 g / L each time, with an interval of 30 minutes between two times to adjust the pH to 7.0, rotate for 110 minutes, heat to 37°C, let stand for 110 minutes, take out the fur, and complete the chrome-free tanning, and the remaining steps are the same as Example 1.

[0046] Performance Testing The waterproof and anti-siphoning leathers obtained in Examples 1-10 and Comparative Examples 1-5 were tested using the following method. The specific test results are shown in Table 1.

[0047] Static water absorption rate: Place the sample in a standard environment of 25°C and 50% relative humidity for 48 hours, then immerse it in distilled water. After 2 hours, gently wipe the water on the surface of the leather with filter paper, and calculate its water absorption rate based on the change in mass before and after.

[0048] Dynamic water absorption rate: refer to ISO 17700, test the sample at 20±2℃ and humidity 65±4% using a dynamic waterproof tester, then immerse the sample in water for 2h, hang it to drain for 2 minutes after taking it out, absorb excess water on the surface with filter paper, and calculate the dynamic water absorption rate of the sample.

[0049] Anti-siphon test: Cut the waterproof and anti-siphon leather into 2x20cm size, pour colored dye water into the anti-siphon tester, the water level is flush with the scale line, first adjust the lower end of the sample to be flush with the lower edge of the anti-siphon tester, and fix it, then fix the upper end of the test sample on the rack, slowly insert the sample rack into the sink filled with blue dye water, and ensure that it is immersed to the 0 scale line of the ruler, immerse for 2h, observe and record the water climbing height every 30min, and if it is less than 1cm, it meets the production requirements.

[0050] Table 1 Performance test results of different waterproof and anti-siphon leathers The test results in Table 1 show that the static water absorption rate and dynamic water absorption rate of the waterproof and anti-siphon leather produced by the waterproof and anti-siphon leather processing technology of the present application are as low as 27.2% and 17.0%, respectively, which have high waterproofness. When the anti-siphon test is performed, the water climbing height is 0.5-0.9cm, which is lower than 1cm, and both meet the production requirements. The minimum water climbing height is 0.5cm, which has high anti-siphon performance and improves the waterproof and anti-siphon performance of the leather.

[0051] According to the performance test data of the waterproof and anti-siphoning leather of Example 1 and Example 2, it is found that the static water absorption rate and dynamic water absorption rate of the waterproof and anti-siphoning leather of Example 2 are 33.2% and 19.2%, and the water climbing height during the anti-siphoning test is 0.8 cm, both of which are lower than that of Example 1, indicating that in the waterproof and anti-siphoning treatment step, the fur is washed with water, neutralized in 50°C water, and then the dispersant Tam NA and soda ash are added and rotated for 40 minutes, and then the dispersant Tam M is added and rotated for 40 minutes, and finally waterproof oil and fluorine-free waterproofing agent are added and rotated for 150 minutes, which is more conducive to improving the waterproof and anti-siphoning performance of the leather.

[0052] According to the performance test data of the waterproof and anti-siphoning leather of Examples 2-4, it was found that the static water absorption rate and dynamic water absorption rate of the waterproof and anti-siphoning leather of Example 4 were 31.5% and 18.2%, and the water climbing height during the anti-siphoning test was 0.7 cm, both of which were lower than those of Examples 2-3, indicating that the fluorine-free waterproofing agent in the compound waterproofing agent in the waterproof and anti-siphoning treatment step is selected from homemade amino-modified silicone oil, which is more conducive to improving the waterproof and anti-siphoning performance of the leather.

[0053] According to the performance test data of the waterproof and anti-siphoning leather of Examples 5-9, it is found that the static water absorption rate and dynamic water absorption rate of the waterproof and anti-siphoning leather of Examples 6-8 are 28.6%-30.0% and 17.2%-17.5%, and the water climbing height during the anti-siphoning test is 0.6 cm, both of which are lower than Examples 5 and 9, indicating that the fluorine-free waterproofing agent in the compound waterproofing agent in the waterproof and anti-siphoning treatment step is selected from homemade amino-modified silicone oil, and when the pretreated hydroxy-terminated polydimethylsiloxane is mixed with the hydrolyzed γ-aminopropyltriethoxysilane and then long-chain alkyl silicone oil is added, and the mass ratio of long-chain alkyl silicone oil to the pretreated hydroxy-terminated polydimethylsiloxane is 1:(5-7), it is more conducive to improving the waterproof and anti-siphoning performance of the leather.

[0054] According to the performance test data of the waterproof and anti-siphon leather of Examples 6-8 and 10, it was found that the static water absorption rate and dynamic water absorption rate of the waterproof and anti-siphon leather of Example 10 were 27.2% and 17.0%, and the water climbing height during the anti-siphon test was 0.5 cm, both of which were lower than those of Examples 6-8, indicating that in the waterproof and anti-siphon treatment step, curing by placing the fur in 45-55°C water, adding formic acid, rotating for 25-35 minutes, adjusting the pH to 3.5, and then adding aluminum tannin and rotating for 55-65 minutes is more conducive to improving the waterproof and anti-siphon performance of the leather.

[0055] According to the performance test data of the waterproof and anti-siphoning leather of Example 1 and Comparative Examples 1-4, it was found that the dispersant Tam NA, dispersant Tam M, oil-proof agent HP and fluorine-free waterproofing agent TPY added to the compound waterproofing agent in the waterproof and anti-siphoning treatment step can all improve the waterproof and anti-siphoning performance of the leather to varying degrees.

[0056] According to the performance test data of the waterproof and anti-siphon leather of Example 1 and Comparative Example 5, it was found that when the tanning step was changed and the chrome tanning was replaced by chrome-free tanning, the water height in the anti-siphon test was not affected. It can be seen that the waterproof and anti-siphon treatment step is an independent waterproof treatment operation, which can be applied to various leather materials and can improve the waterproof and anti-siphon performance of the leather.

[0057] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A processing technology for waterproof and anti-siphon leather, characterized in that: The processing technology includes the following processing steps: soaking, re-soaking, degreasing, pickling, tanning, stuffing, washing, re-stuffing, re-tanning, dyeing, waterproofing and anti-siphoning treatment, drying and finishing, and surface finishing of the fur; The waterproof and anti-siphon treatment is specifically as follows: after the filling, retanning and dyeing, the fur is washed with water, neutralized in 48-52°C water, and then a compound waterproofing agent is added and then rotated, fixed, and water is removed before entering the drying and finishing process; The compound waterproofing agent is prepared by adding 0.8-1.2 g of dispersant Tam NA, 0.8-1.2 g of soda ash, 0.07-0.09 g of dispersant Tam M, 2-3 g of waterproofing oil and 2-3 g of fluorine-free waterproofing agent into each liter of water.

2. The processing technology of waterproof and anti-siphon leather according to claim 1 is characterized in that: The specific steps of adding the compound waterproofing agent are: first add dispersant Tam NA and soda ash and rotate for 35-45 minutes, then add dispersant Tam M and rotate for 35-45 minutes, and finally add waterproof oil and fluorine-free waterproofing agent and rotate for 140-160 minutes.

3. The processing technology of waterproof and anti-siphon leather according to claim 1 is characterized in that: The fluorine-free waterproofing agent in the compound waterproofing agent is selected from at least one of fluorine-free waterproofing agent TPY, modified silicone oil, silicone resin, long-chain alkane, paraffin and palm wax.

4. The processing technology of waterproof and anti-siphon leather according to claim 3 is characterized in that: The modified silicone oil is prepared by the following steps: S1, dehydrating the hydroxyl-terminated polydimethylsiloxane under reduced pressure at 100-120° C. for 1-2 h, adding tetrahydrofuran and mixing, adding hexamethylene diisocyanate, dropping dibutyltin dilaurate, reacting under magnetic stirring at 50-70° C. for 2-4 h, cooling, and distilling under reduced pressure to obtain pretreated hydroxyl-terminated polydimethylsiloxane; S2, adding γ-aminopropyltriethoxysilane to water, adding acetic acid to adjust the pH to 4-5, stirring at 23±2° C. for 2-4 hours, neutralizing, and obtaining hydrolyzed γ-aminopropyltriethoxysilane; S3. Under nitrogen protection, the pretreated hydroxyl-terminated polydimethylsiloxane and the hydrolyzed γ-aminopropyltriethoxysilane are mixed at 80-120° C. for 2-6 hours, tetramethylammonium hydroxide and an antioxidant are added, stirred at 80-90° C. under nitrogen protection for 4-6 hours, vacuum dehydrated, adjusted to pH 6-7, filtered, and amino-modified silicone oil is obtained.

5. The processing technology of waterproof and anti-siphon leather according to claim 4 is characterized in that: The mass ratio of the hydrolyzed γ-aminopropyltriethoxysilane to the pretreated hydroxyl-terminated polydimethylsiloxane is 1:(8-12).

6. The processing technology of waterproof and anti-siphon leather according to claim 4 is characterized in that: The pretreated hydroxyl-terminated polydimethylsiloxane is mixed with the hydrolyzed γ-aminopropyltriethoxysilane and then long-chain alkyl silicone oil is added; the mass ratio of the long-chain alkyl silicone oil to the pretreated hydroxyl-terminated polydimethylsiloxane is 1:(5-7).

7. The processing technology of waterproof and anti-siphon leather according to claim 1 is characterized in that: The fixing in the waterproof and anti-siphoning treatment step is specifically as follows: placing the fur in 45-55°C water, adding formic acid, rotating for 25-35 minutes and adjusting the pH to 3.5, and then adding aluminum tannin and rotating for 55-65 minutes; The dosage of formic acid and aluminum tannin is 0.8-1.2 g per liter of water.

8. A waterproof and anti-siphon leather obtained by the processing technology of the waterproof and anti-siphon leather according to any one of claims 1 to 7.

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