Antibacterial mildew-proof leather material and preparation method thereof

Abstract

The invention discloses an antibacterial and mildewproof leather material and a preparation method thereof. The antibacterial and mildewproof leather material comprises a leather base material as well as rare earth antibacterial and mildewproof powder AB-007, 2, 8-dihydroxyquinoline and 2-hydroxypyridine nitrogen oxide which are uniformly dispersed in the leather base material. The method ensures that the prepared leather has the excellent characteristics of high efficiency, durability, safety, environment friendliness and the like, and does not contain harmful heavy metal components. Meanwhile, wastewater generated in the production process can be recycled, wastewater discharge is effectively reduced, and the method has good energy-saving and environment-friendly characteristics.

Description

Technical Field

[0001] The invention belongs to the technical field of leather materials, and in particular relates to an antibacterial and mildew-proof leather material and a preparation method thereof. Background Art

[0002] Leather products are widely used in daily life. As a natural polymer material, leather is mainly composed of collagen and animal fats, which provide a rich source of nutrients for mold growth. In addition, the porous structure, high water content and good hygroscopicity of leather also create a suitable environment for mold growth. These factors together lead to the frequent appearance of white, blue, yellow and black mold spots, and the in-depth development of mold further affects the wear resistance, strength and elasticity of leather.

[0003] At present, there are many effective ways to prevent leather from mildewing, but among the many options, adding mildew inhibitors is the most common and effective choice. However, there are many types of existing mildew inhibitors, most of which have varying degrees of negative impacts on humans, animals and the environment. For example, the traditional mildew inhibitor trichlorophenol has been banned due to safety hazards. Nowadays, 2-thiocyanatomethylthiobenzothiazole (TCMTB), a highly efficient and environmentally friendly mildew inhibitor developed by Buckman, is widely used. However, due to long-term use, fungi's resistance to TCMTB has been significantly enhanced, resulting in a significant decrease in its mildew prevention effect, making it difficult to meet market demand.

[0004] Although new compositions such as the mixture of propiconazole and TCMTB in US6110950 and the combination of triclosan and other ingredients in US20060014810 help improve the anti-mildew performance, their effects are still insufficient to meet the needs of practical applications. Especially in humid seasons, leather shoes are prone to mildew. Mold not only affects product quality and causes economic losses, but the spread of its spores may also cause harm to the environment and human health.

[0005] With the increasingly stringent environmental regulations, the use of many traditional antifungal agents may be restricted. Therefore, it is particularly urgent to develop low-toxic, non-polluting and environmentally friendly antifungal agents, which are essential for the long-term protection and sustainable development of leather products. Summary of the invention

[0006] The present invention aims to overcome the defects of the prior art and provide an antibacterial and mildew-proof leather material.

[0007] Another object of the present invention is to provide a method for preparing the antibacterial and mildew-proof leather material.

[0008] The technical solution of the present invention is as follows:

[0009] An antibacterial and mildew-proof leather material comprises a leather base material and rare earth antibacterial and mildew-proof powder AB-007, 2,8-dihydroxyquinoline and 2-hydroxypyridine nitrogen oxide uniformly dispersed in the leather base material.

[0010] In a preferred embodiment of the present invention, the mass ratio of the rare earth antibacterial and anti-mildew powder AB-007, 2,8-dihydroxyquinoline and 2-hydroxypyridine nitrogen oxide is 15-30:7-10:3-10.

[0011] The method for preparing the above-mentioned antibacterial and mildew-proof leather material comprises the following steps:

[0012] (1) Mix rare earth antibacterial and antifungal powder AB-007, 2,8-dihydroxyquinoline, 2-hydroxypyridine nitrogen oxide and deionized water and grind them into a mixture of D 90 =1.75-2.75 μm, followed by filtration to obtain the leather antibacterial and antifungal agent stock solution;

[0013] (2) placing the leather substrate to be treated in a special rotary drum, and sequentially performing rewetting, neutralization, retanning, filling, dyeing, fatliquoring and fixing treatments, then adding the leather antibacterial and mildewproof agent stock solution prepared in step (1) and deionized water for rotary treatment, then taking out the material in the special rotary drum, sequentially performing water squeezing, natural drying and finishing processes, and thus obtaining the antibacterial and mildewproof leather material;

[0014] (3) Determine the solid content of the antibacterial and mildew-proof agent in the liquid in the special drum of step (2), take an appropriate amount of the liquid and dry it to constant weight to obtain a test sample; then add the leather antibacterial and mildew-proof agent stock solution obtained in step (1) to the liquid according to the weight of the test sample, so that the ratio of the effective ingredients of the leather antibacterial and mildew-proof agent stock solution in the waste liquid to the leather to be subsequently treated reaches the level of step (2); then reuse it, that is, prepare the antibacterial and mildew-proof leather material according to the parameters of step (2).

[0015] In a preferred embodiment of the present invention, the ball milling in step (1) is carried out using zirconium beads with a diameter of 4-6 mm.

[0016] Further preferably, in the ball milling in step (1), the grinding rate is 190-210 r / min and the time is 50-70 min.

[0017] In a preferred embodiment of the present invention, in step (1), the mass ratio of rare earth antibacterial and anti-mildew powder AB-007, 2,8-dihydroxyquinoline, 2-hydroxypyridine nitrogen oxide and deionized water is 15-30:7-10:3-10:60.

[0018] In a preferred embodiment of the present invention, in the rotary immersion treatment, the rotation speed is 6-9 r / min and the time is 1-2 h.

[0019] Further preferably, in the step (2), the mass ratio of the leather substrate, the leather antibacterial and mildew-proofing agent stock solution and deionized water is 480-520:62-63:740-750.

[0020] In a preferred embodiment of the present invention, the reuse is no more than 5 times, after which the liquid is evaporated to dryness and the remaining material is treated as solid waste to ensure no pollution.

[0021] In a preferred embodiment of the present invention, the leather substrate to be treated is wet blue leather or wet white leather, and its sources include cowhide, sheepskin and pigskin.

[0022] The beneficial effects of the present invention are:

[0023] 1. The present invention combines the environmentally friendly, efficient and durable rare earth antibacterial and mildew-proof powder AB-007, which is insoluble in water, and two antibacterial agents: one is 2,8-dihydroxyquinoline, which is insoluble in water, and the other is 2-hydroxypyridine nitrogen oxide, which is slightly soluble in water. The characteristics of rare earth ions in the rare earth antibacterial and mildew-proof powder AB-007 are utilized. These ions can destroy the bacterial cell wall, causing the cytoplasm to flow out, thereby causing the bacteria to lose their replication function and eventually die. In addition, 2,8-dihydroxyquinoline has the effect of inhibiting the synthesis of RNA and metallopeptidase, while 2-hydroxypyridine nitrogen oxide inhibits the formation of biofilm through nucleophilic action and acts on cell targets.

[0024] 2. Through the synergistic effect of these three components, the present invention can effectively inhibit and kill common molds such as Aspergillus, Penicillium, Fusarium, and Claviceps in leather, thereby giving the leather antibacterial and antifungal agent a broad-spectrum, long-lasting and efficient performance. This combination not only improves the antibacterial and antifungal ability of leather products, but also has environmentally friendly characteristics because it does not contain harmful heavy metal components, which meets the current requirements for sustainable development and environmental protection.

[0025] 3. The wastewater generated in the production process of the present invention can be reused, which effectively reduces wastewater discharge and has good energy-saving and environmental protection characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a physical photograph (15d) of the anti-mildew performance test results of the blank sample of the present invention.

[0027] Figure 2 This is a physical photograph (30d) of the test results of the mildew resistance of the antibacterial and mildew resistance leather material prepared in Example 2 of the present invention.

[0028] Figure 3 This is a physical photograph (30d) of the test results of the mildew resistance of the antibacterial and mildew resistance leather material prepared in Example 3 of the present invention.

[0029] Figure 4 This is a photo of the antibacterial test results of the blank sample of the present invention (24h).

[0030] Figure 5 This is a photo of the antibacterial test results (24h) of the antibacterial and mildew-proof leather material prepared in Example 2 of the present invention.

[0031] Figure 6 This is a photo of the antibacterial test results (24h) of the antibacterial and mildew-proof leather material prepared in Example 3 of the present invention. DETAILED DESCRIPTION

[0032] The technical solution of the present invention is further illustrated and described below through specific implementation modes in combination with the accompanying drawings.

[0033] In the following examples and comparative examples:

[0034] The leather base material is cowhide blank produced in large quantities by Xingye Leather Technology Co., Ltd.

[0035] Rare earth antibacterial and anti-mildew powder AB-007 (active ingredients are lanthanum and cerium), purchased from Jinshilan (Xiamen) New Materials Co., Ltd., with a purity of more than 99%, a moisture content of less than 1%, and a particle size of D 90 =30μm, pH of aqueous solution =6.

[0036] 2,8-Dihydroxyquinoline was purchased from Jiangxi Ruiweier Biotechnology Co., Ltd. with a purity of more than 98%, a moisture content of less than 0.5%, and a particle size of D 90 =50μm.

[0037] 2-Hydroxypyridine N-oxide was purchased from Jiangxi Ruiweier Biotechnology Co., Ltd. with a purity of more than 98%, a moisture content of less than 0.5%, and a particle size of D 90 =50μm.

[0038] Deionized water is grade 3 deionized water treated by a water purifier.

[0039] Example 1

[0040] (1) In a ball mill, add 20.0 g of rare earth antibacterial and antifungal powder AB-007, 10.0 g of 2,8-dihydroxyquinoline, 10.0 g of 2-hydroxypyridine nitrogen oxide and 60.0 g of deionized water, add 300.0 g of zirconium beads with a particle size of 5 mm, grind at a grinding rate of 200 r / min for 60 min, take the liquid and use a laser particle size analyzer to test the powder particle size, D 90=2.48μm, stop rotating, filter the zirconium beads with an 80-mesh filter to obtain the original solution of the antibacterial and antifungal agent for leather;

[0041] (2) placing about 5000.0 g of leather into a special drum, and sequentially performing rewetting, neutralization, retanning, filling, dyeing, fatliquoring and fixing treatments, and then adding about 625.0 g of the leather antibacterial and mildew-proof agent solution prepared in step (1) and 7500.0 g of deionized water; rotating the drum at a speed of 9 r / min for 1 h, then taking out the material in the special drum, squeezing out water, naturally drying, and then performing finishing process treatment to obtain an antibacterial and mildew-proof leather material;

[0042] (3) Determine the solid content of the antibacterial and mildew-proof agent in the liquid in the special drum of step (2), take about 2.0 g of the liquid and dry it at 105° C. to constant weight, measure three samples in parallel, and obtain an average value; then add the leather antibacterial and mildew-proof agent stock solution obtained in step (1) to the liquid according to the average value, so that the ratio of the effective components of the leather antibacterial and mildew-proof agent stock solution in the waste liquid to the leather to be subsequently treated reaches the level of step (2); then reuse, that is, prepare the antibacterial and mildew-proof leather material according to the parameters of step (2); it should be noted that the reuse shall not exceed 5 times, and after more than 5 times, the liquid in the special drum shall be evaporated to dryness, and the remaining material shall be treated as solid waste to ensure no pollution;

[0043] (4) The antibacterial and mildew-proof leather material obtained in steps (2) and (3) is subjected to accelerated antibacterial and mildew-proof testing. After determining that the antibacterial and mildew-proof rate meets the standard, the next process can be carried out.

[0044] Example 2

[0045] (1) In a ball mill, add 30.0 g of rare earth antibacterial and antifungal powder AB-007, 7.0 g of 2,8-dihydroxyquinoline, 3.0 g of 2-hydroxypyridine nitrogen oxide and 60.0 g of deionized water, add 300.0 g of zirconium beads with a particle size of 5 mm, grind at a grinding rate of 200 r / min for 60 min, take the liquid and use a laser particle size analyzer to test the powder particle size, D 90 =1.75μm, stop rotating, filter the zirconium beads with an 80-mesh filter to obtain the original solution of the antibacterial and antifungal agent for leather;

[0046] (2) placing about 5000.0 g of leather into a special drum, and sequentially performing rewetting, neutralization, retanning, filling, dyeing, fatliquoring and fixing treatments, and then adding about 625.0 g of the leather antibacterial and mildew-proof agent solution prepared in step (1) and 7500.0 g of deionized water; rotating the drum at a speed of 6 r / min for 2 h, then taking out the material in the special drum, squeezing out water, naturally drying, and then performing finishing process treatment to obtain an antibacterial and mildew-proof leather material;

[0047] (3) Determine the solid content of the antibacterial and mildew-proof agent in the liquid in the special drum of step (2), take about 2.0 g of the liquid and dry it at 105° C. to constant weight, measure three samples in parallel, and obtain an average value; then add the leather antibacterial and mildew-proof agent stock solution obtained in step (1) to the liquid according to the average value, so that the ratio of the effective components of the leather antibacterial and mildew-proof agent stock solution in the waste liquid to the leather to be subsequently treated reaches the level of step (2); then reuse, that is, prepare the antibacterial and mildew-proof leather material according to the parameters of step (2); it should be noted that the reuse shall not exceed 5 times, and after more than 5 times, the liquid in the special drum shall be evaporated to dryness, and the remaining material shall be treated as solid waste to ensure no pollution;

[0048] (4) The antibacterial and mildew-proof leather material obtained in steps (2) and (3) is subjected to accelerated antibacterial and mildew-proof testing. After determining that the antibacterial and mildew-proof rate meets the standard, the next process can be carried out.

[0049] Example 3

[0050] (1) In a ball mill, add 15.0 g of rare earth antibacterial and antifungal powder AB-007, 8.0 g of 2,8-dihydroxyquinoline, 7.0 g of 2-hydroxypyridine nitrogen oxide and 60.0 g of deionized water, add 300.0 g of zirconium beads with a particle size of 5 mm, grind at a grinding rate of 200 r / min for 60 min, take the liquid and use a laser particle size analyzer to test the powder particle size, D 90 =2.75μm, stop rotating, filter the zirconium beads with an 80-mesh filter to obtain the original solution of the antibacterial and antifungal agent for leather;

[0051] (2) placing about 5000.0 g of leather into a special drum, and sequentially performing rewetting, neutralization, retanning, filling, dyeing, fatliquoring and fixing treatments, and then adding about 625.0 g of the leather antibacterial and mildew-proof agent solution prepared in step (1) and 7500.0 g of deionized water; rotating the drum at a speed of 7 r / min for 1.5 h, then taking out the material in the special drum, squeezing out water, naturally drying, and then performing finishing process treatment to obtain an antibacterial and mildew-proof leather material;

[0052] (3) Determine the solid content of the antibacterial and mildew-proof agent in the liquid in the special drum of step (2), take about 2.0 g of the liquid and dry it at 105° C. to constant weight, measure three samples in parallel, and obtain an average value; then add the leather antibacterial and mildew-proof agent stock solution obtained in step (1) to the liquid according to the average value, so that the ratio of the effective components of the leather antibacterial and mildew-proof agent stock solution in the waste liquid to the leather to be subsequently treated reaches the level of step (2); then reuse, that is, prepare the antibacterial and mildew-proof leather material according to the parameters of step (2); it should be noted that the reuse shall not exceed 5 times, and after more than 5 times, the liquid in the special drum shall be evaporated to dryness, and the remaining material shall be treated as solid waste to ensure no pollution;

[0053] (4) The antibacterial and mildew-proof leather material obtained in steps (2) and (3) is subjected to accelerated antibacterial and mildew-proof testing. After determining that the antibacterial and mildew-proof rate meets the standard, the next process can be carried out.

[0054] Comparative Example 1

[0055] (1) In a ball mill, add 0g of rare earth antibacterial and antifungal powder AB-007, 20.0g of 2,8-dihydroxyquinoline, 20.0g of 2-hydroxypyridine nitrogen oxide and 60.0g of deionized water, add 300.0g of zirconium beads with a particle size of 5mm, grind at a grinding rate of 200r / min for 60min, take the liquid and use a laser particle size analyzer to test the powder particle size, D 90 =2.15μm, stop rotating, filter the zirconium beads with an 80-mesh filter to obtain the original solution of the antibacterial and antifungal agent for leather;

[0056] (2) placing about 5000.0 g of leather into a special drum, and sequentially performing rewetting, neutralization, retanning, filling, dyeing, fatliquoring and fixing treatments, and then adding about 625.0 g of the leather antibacterial and mildew-proof agent solution prepared in step (1) and 7500.0 g of deionized water; rotating the drum at a speed of 9 r / min for 1 h, then taking out the material in the special drum, squeezing out water, naturally drying, and then performing finishing process treatment to obtain an antibacterial and mildew-proof leather material;

[0057] (3) Determine the solid content of the antibacterial and mildew-proof agent in the liquid in the special drum of step (2), take about 2.0 g of the liquid and dry it at 105° C. to constant weight, measure three samples in parallel, and obtain an average value; then add the leather antibacterial and mildew-proof agent stock solution obtained in step (1) to the liquid according to the average value, so that the ratio of the effective components of the leather antibacterial and mildew-proof agent stock solution in the waste liquid to the leather to be subsequently treated reaches the level of step (2); then reuse, that is, prepare the antibacterial and mildew-proof leather material according to the parameters of step (2); it should be noted that the reuse shall not exceed 5 times, and after more than 5 times, the liquid in the special drum shall be evaporated to dryness, and the remaining material shall be treated as solid waste to ensure no pollution;

[0058] (4) The antibacterial and mildew-proof leather material obtained in steps (2) and (3) is subjected to accelerated antibacterial and mildew-proof testing. After determining that the antibacterial and mildew-proof rate meets the standard, the next process can be carried out.

[0059] Comparative Example 2

[0060] (1) In a ball mill, add 30.0 g of rare earth antibacterial and antifungal powder AB-007, 10.0 g of 2,8-dihydroxyquinoline, 0 g of 2-hydroxypyridine nitrogen oxide and 60.0 g of deionized water, add 300.0 g of zirconium beads with a particle size of 5 mm, grind at a grinding rate of 200 r / min for 60 min, take the liquid and use a laser particle size analyzer to test the powder particle size, D 90 =2.45μm, stop rotating, filter the zirconium beads with an 80-mesh filter to obtain the original solution of the antibacterial and antifungal agent for leather;

[0061] (2) putting about 5000.0 g of leather into a special drum, and then adding about 625.0 g of the leather antibacterial and mildew-proof agent solution prepared in step (1) and 7500.0 g of deionized water; rotating the drum at a speed of 6 r / min for 2 h to impart properties, then taking out the material in the special drum, squeezing out water, naturally drying, and then performing a finishing process to obtain an antibacterial and mildew-proof leather material;

[0062] (3) Determine the solid content of the antibacterial and mildew-proof agent in the liquid in the special drum of step (2), take about 2.0 g of the liquid and dry it at 105° C. to constant weight, measure three samples in parallel, and obtain an average value; then add the leather antibacterial and mildew-proof agent stock solution obtained in step (1) to the liquid according to the average value, so that the ratio of the effective components of the leather antibacterial and mildew-proof agent stock solution in the waste liquid to the leather to be subsequently treated reaches the level of step (2); then reuse, that is, prepare the antibacterial and mildew-proof leather material according to the parameters of step (2); it should be noted that the reuse shall not exceed 5 times, and after more than 5 times, the liquid in the special drum shall be evaporated to dryness, and the remaining material shall be treated as solid waste to ensure no pollution;

[0063] (4) The antibacterial and mildew-proof leather material obtained in steps (2) and (3) is subjected to accelerated antibacterial and mildew-proof testing. After determining that the antibacterial and mildew-proof rate meets the standard, the next process can be carried out.

[0064] The following are the antibacterial and mildew-proof test data of the leather materials obtained in the examples and comparative examples. The antibacterial and mildew-proof properties were tested according to the QBT 4199-2011 leather mildew-proof property test method to observe whether mildew grows on the surface and how long it takes for mildew to grow.

[0065] The specific steps include:

[0066] (1) Place two groups of samples in two culture dishes, with the grain side facing up;

[0067] (2) Centrifuge 1 mL of the mixed fungal spore suspension, remove the supernatant, add 0.25 mL of Green's solution to dilute, and shake well to obtain a suspension;

[0068] (3) Take 10 μL of the suspension and add it to the center of the two groups of samples. Seal the culture dishes with medical tape and place them in an incubator with saturated humidity at 25±2°C for 120 days. Check the fungal growth at regular intervals using a 50x optical microscope.

[0069] Table 2 Anti-mildew performance results of examples and comparative examples

[0070] Group 7d 15d 30d 60d 90d 120d Blank 3 3 3 3 3 3 Example 1 1 1 1 1 1 2 Example 2 1 1 1 1 1 1 Example 3 1 1 1 1 1 2 Comparative Example 1 2 3 3 3 3 3 Comparative Example 2 1 2 3 3 3 3

[0071] Note: The numbers in Table 2 represent the mildew resistance levels as follows: "1" means there is no mildew on the surface of the sample; "2" means less than 1 / 3 of the surface of the sample has mildew; "3" means more than 1 / 3 of the surface of the sample is covered with mildew.

[0072] Among them, the actual photos of the anti-mildew performance of the blank sample, Example 2 and Example 3 are as follows: Figures 1 to 3 shown.

[0073] Antibacterial experimental detection method: According to the inhibition zone test method specified in "QB / T 2881-2013 Technical Requirements for Antibacterial Performance of Footwear and Footwear Components", two kinds of bacteria are poured on the corresponding solid culture medium and sterilized glass beads are rocked to distribute them evenly; then a circular sample with a diameter of 15mm or a square sample with a side length of 15mm is placed, and cultured in a constant temperature oven at 37±1℃ for 24h, and the diameter of the inhibition zone is measured.

[0074] Table 3 Antibacterial performance results of examples and comparative examples

[0075]

[0076]

[0077] Note: The sensitivity of commercial drugs is usually determined by the diameter of the inhibition zone >20mm, extremely sensitive; 15-20mm, highly sensitive; 10-14mm, moderately sensitive; <10mm, insensitive.

[0078] Among them, the actual photographs of the antibacterial performance of the blank sample, Example 2 and Example 3 are shown in order. Figures 4 to 6 shown.

[0079] The above description is only a preferred embodiment of the present invention, and therefore cannot be used to limit the scope of the present invention. That is, equivalent changes and modifications made according to the patent scope of the present invention and the contents of the specification should still fall within the scope of the present invention.

Claims

1. An antibacterial and mildew-proof leather material, characterized in that: The invention comprises a leather base material and rare earth antibacterial and antifungal powder AB-007, 2,8-dihydroxyquinoline and 2-hydroxypyridine nitrogen oxide uniformly dispersed in the leather base material.

2. The method according to claim 1, characterized in that: The mass ratio of the rare earth antibacterial and anti-mildew powder AB-007, 2,8-dihydroxyquinoline and 2-hydroxypyridine nitrogen oxide is 15-30:7-10:3-10.

3. The method for preparing the antibacterial and mildew-proof leather material according to claim 1 or 2, characterized in that: The steps include: (1) Mix rare earth antibacterial and antifungal powder AB-007, 2,8-dihydroxyquinoline, 2-hydroxypyridine nitrogen oxide and deionized water and grind them into a mixture of D 90 =1.75-2.75 μm, followed by filtration to obtain the leather antibacterial and antifungal agent stock solution; (2) placing the leather substrate to be treated in a special rotary drum, and sequentially performing rewetting, neutralization, retanning, filling, dyeing, fatliquoring and fixing treatments, then adding the leather antibacterial and mildewproof agent stock solution prepared in step (1) and deionized water for rotary treatment, then taking out the material in the special rotary drum, sequentially performing water squeezing, natural drying and finishing processes, and thus obtaining the antibacterial and mildewproof leather material; (3) Determine the solid content of the antibacterial and mildew-proof agent in the liquid in the special drum of step (2), take an appropriate amount of the liquid and dry it to constant weight to obtain a test sample; then add the leather antibacterial and mildew-proof agent stock solution obtained in step (1) to the liquid according to the weight of the test sample, so that the ratio of the effective ingredients of the leather antibacterial and mildew-proof agent stock solution in the waste liquid to the leather to be subsequently treated reaches the level of step (2); then reuse it, that is, prepare the antibacterial and mildew-proof leather material according to the parameters of step (2).

4. The preparation method according to claim 3, characterized in that: The ball milling in step (1) is performed using zirconium beads with a diameter of 4-6 mm.

5. The preparation method according to claim 4, characterized in that: In the ball milling in step (1), the grinding rate is 190-210 r / min and the time is 50-70 min.

6. The preparation method according to claim 4 or 5, characterized in that: In the step (1), the mass ratio of the rare earth antibacterial and anti-mildew powder AB-007, 2,8-dihydroxyquinoline, 2-hydroxypyridine nitrogen oxide and deionized water is 15-30:7-10:3-10:

60.

7. The preparation method according to claim 3, characterized in that: In the rotary soaking treatment, the rotation speed is 6-9 r / min and the time is 1-2 h.

8. The preparation method according to claim 3, characterized in that: In the step (2), the mass ratio of the leather substrate, the leather antibacterial and mildew-proofing agent stock solution and deionized water is 480-520:62-63:740-750.

9. The preparation method according to claim 3, characterized in that: The reuse is no more than 5 times. After more than 5 times, the liquid is evaporated to dryness and the remaining material is treated as solid waste to ensure no pollution.

10. The preparation method according to any one of claims 1 to 9, characterized in that: The leather substrate to be treated is wet blue leather or wet white leather.

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