Preparation method of leather with multiple antibacterial long-acting antibacterial function

Abstract

The invention relates to a preparation method of leather with a multi-antibacterial type long-acting antibacterial function. The preparation method comprises the following steps of wet blue leather pretreatment, antibacterial retanning, filling dyeing, fat liquoring, antibacterial treatment, drying finishing and antibacterial coating. Wherein the antibacterial retanning adopts eucalyptus oil / dialdehyde cyclodextrin as an aldehyde retanning agent for aldehyde retanning; in the antibacterial treatment, eucalyptus oil and beta-cyclodextrin are used as antibacterial agents to carry out antibacterial occurrence treatment, the eucalyptus oil and the beta-cyclodextrin take essential oil extracted from natural herbaceous plant eucalyptus leaves as clathrate compounds, the beta-cyclodextrin is used as a main body, and a modified antibacterial agent beta-cyclodextrin and eucalyptus oil clathrate compound is prepared through a molecular clathration technology. As an antibacterial agent, an occurrence process is designed for antibacterial treatment; the antibacterial coating adopts a coating containing silver ions to be applied to a leather coating process; through triple antibiosis, the leather is more durable in antibiosis performance and more efficient.

Description

Technical Field

[0001] The invention relates to the technical field of leather manufacturing, and in particular to a method for preparing leather with multiple antibacterial and long-acting antibacterial functions. Background Art

[0002] With the rapid development of the global social economy and the continuous improvement of people's living standards, the public's attention to health, safety and environmental protection has increased. In this context, the research and application of antibacterial materials have become the focus of innovation and development in many industries. Leather, as a traditional material widely used in clothing, shoes, furniture and automotive interiors, can not only meet consumers' demand for high-quality, healthy and environmentally friendly products, but also has important significance for promoting the sustainable development of the leather industry.

[0003] The development and application of antibacterial leather came into being in response to the needs of the times. By introducing various antibacterial technologies, such as silver ion antibacterial, quaternary ammonium salt antibacterial, and silicone antibacterial, antibacterial leather can inhibit the growth of microorganisms such as bacteria and fungi to a certain extent, reduce the risk of cross-infection, and thus improve the hygienic safety and service life of the product. In addition, the preparation and application of antibacterial leather also reflects the combined influence of scientific and technological progress, environmental awareness and regulatory requirements. For example, the strict supervision of the use of chemicals by the EU REACH regulation has prompted leather manufacturers to find safer and more environmentally friendly antibacterial methods.

[0004] However, the existing antibacterial leather still has some drawbacks and limitations, such as insufficient durability of the antibacterial effect, safety issues, limitations of the antibacterial spectrum, etc. These drawbacks limit the wide application and market competitiveness of antibacterial leather.

[0005] Based on the above reasons, molecular inclusion technology is used to improve the lack of durability caused by its poor stability, and natural active ingredients and silver ions are used to solve its safety issues and limitations. Summary of the invention

[0006] The invention provides a method for preparing leather with multiple antibacterial and long-acting antibacterial functions, so as to solve the problems of insufficient durability, safety problems, and limitation of antibacterial spectrum of the existing antibacterial leather.

[0007] The present invention adopts the following technical solution:

[0008] A method for preparing leather with multiple antibacterial and long-lasting antibacterial functions, comprising the following steps: wet blue leather pretreatment → antibacterial retanning → filling and dyeing → fatliquoring → antibacterial treatment → drying and finishing → antibacterial coating;

[0009] Wet blue leather pretreatment: squeeze and stretch the wet blue leather, shave it, weigh it, and use 120-150% of the weight of the wet blue leather to determine the weight of the chemical materials used in the subsequent treatment steps; then put the shaved wet blue leather into a drum for rewetting and neutralization treatment;

[0010] Antibacterial retanning: adding 150-200% water and 2.0-3.0% eucalyptus oil-dialdehyde cyclodextrin (DACD) into a drum, adjusting the temperature inside the drum to 30-40°C, and rotating for 20-30 minutes; then adding 3.0-4.0% chromium powder, 2.0-3.0% chromium-containing tannin, and 1.0-1.5% pickling oil, and rotating for 60-80 minutes; adding 1.0-1.5% sodium formate again, and then adding 1.0-2.0% eucalyptus oil-dialdehyde cyclodextrin (DACD), and rotating for 20 minutes; finally adding 0.8-1.0% baking soda, rotating for 40-60 minutes, adjusting the pH of the bath liquid to 4.0-4.3, stopping the drum overnight, and draining the liquid after rotating for 20-30 minutes the next day;

[0011] Filling and dyeing: the amount of reagent is calculated as 120-150% of the weight of the wet blue leather after shaving, 80-100% of water, 3.0-4.0% of polymer retanning agent, 1.0-1.5% of fatliquor are added to the drum, and the drum is rotated for 60-80 minutes; then 3.0-4.0% of melamine resin retanning agent, 3.0-4.0% of phenolic tannin, 3.0-4.0% of dicyandiamide resin retanning agent, 3.0-4.0% of synthetic tanning agent, 3.0-4.0% of white tannin, 0.3-0.5% of eucalyptus oil-dialdehyde cyclodextrin (DACD) inclusion compound are added, and the drum is rotated for 30-40 minutes;

[0012] Fatliquor: the dosage of reagent is calculated as 120-150% of the weight of the wet blue leather after shaving. Add 2.0-3.0% dye to the drum, rotate for 40-60 minutes, and check the cut; add 100-150% hot water at a temperature of 50°C and 2.0-2.5% protein filler, rotate for 10-20 minutes; then add 3.0-4.0% fatliquor, 3.0-4.0% fatliquor, 2.0-3.0% neatsfoot oil, 2.0-3.0% synthetic fatliquor, rotate for 60-80 minutes, and check the dyeing;

[0013] Antibacterial treatment: the amount of reagent used is calculated as 120-150% of the weight of the wet blue leather after shaving, 2.0-3.0% of eucalyptus oil and β-cyclodextrin (β-CD) inclusion compound is added to the drum, and the drum is rotated for 60-120 minutes; then 2.5-3.0% of formic acid is added twice, the pH of the bath liquid is adjusted to 3.0-3.2, washed with water, and discharged from the drum; then drying, softening, and calendering are performed;

[0014] Antibacterial finishing: including the following steps: primer → calendering → top coating → calendering → top coating → ironing → finished product;

[0015] Primer 2-3 times, total coating weight 10-20g / SF; topcoat 2-3 times, total coating weight 8-12g / SF;

[0016] The above-mentioned primer formula is: 250-350 parts of water, 80-100 parts of cationic polyurethane (K-6102), 80-100 parts of cationic casein (K-4080), 180-250 parts of non-ionic oil wax mixture (NI 1303, 1705), 25 parts of cationic coating (KP); 1-5% of nano silver aqueous dispersion (particle size <20nm, concentration ≥1000ppm);

[0017] The top coating formula is: 200-300 parts of water, 50-100 parts of cationic polyurethane (K-6102), 20-50 parts of cationic casein (K-4080), 80-150 parts of non-ionic oil wax (1705), 1-5% of nano silver aqueous dispersion (particle size <20nm, concentration ≥1000ppm); top coating 1-2 times, total coating amount 2-5g / SF.

[0018] Furthermore, the preparation of the inclusion complex of β-cyclodextrin (β-CD) and eucalyptus oil (EO) comprises the following steps:

[0019] Step 1, adding 1-10 g of eucalyptus oil (EO) into deionized water, and stirring the mixture magnetically to make it uniform, to obtain a eucalyptus oil (EO) solution;

[0020] Step 2, taking a eucalyptus oil (EO) solution, adding 80-100 g of β-cyclodextrin (β-CD), stirring evenly at 30-50° C., and reacting for 4-8 hours to make the eucalyptus oil (EO) and β-cyclodextrin (β-CD) aqueous solution system uniform;

[0021] Step 3, placing the eucalyptus oil (EO) and β-cyclodextrin (β-CD) aqueous solution under refrigeration conditions to form a stable inclusion complex (EO / β-CD) solution overnight;

[0022] Step 4, placing the inclusion complex solution in a suction filter to obtain inclusion complex crystals, and drying them in a vacuum drying oven at 50-60° C. for 2-3 h to obtain an inclusion complex (EO / β-CD) of β-cyclodextrin (β-CD) and eucalyptus oil (EO).

[0023] Furthermore, the preparation of the inclusion complex (EO / DACD) of the above-mentioned dialdehyde cyclodextrin (DACD) and the above-mentioned eucalyptus oil (EO) comprises the following steps:

[0024] Step 1, adding 1-10 g of eucalyptus oil (EO) into deionized water, and stirring the mixture magnetically to make it uniform, to obtain a eucalyptus oil (EO) solution;

[0025] Step 2, taking eucalyptus oil (EO) solution, adding 80-100g of dialdehyde cyclodextrin (DACD), stirring evenly at 30-50°C, and reacting for 4-8h to make the EO and dialdehyde cyclodextrin (DACD) aqueous solution system uniform;

[0026] Step 3, placing the eucalyptus oil (EO) and dialdehyde cyclodextrin (DACD) aqueous solution under refrigeration conditions to form a stable inclusion complex (EO / DACD) solution overnight;

[0027] Step 4, placing the inclusion complex (EO / DACD) solution in a suction filter to obtain eucalyptus oil-dialdehyde cyclodextrin (EO / DACD) crystals, and drying them in a vacuum drying oven at 50-60° C. for 2-3 h to obtain an inclusion complex (EO / DACD) of DACD and eucalyptus oil.

[0028] Furthermore, the preparation of the above-mentioned dialdehyde cyclodextrin (DACD) comprises the following steps:

[0029] Step 1, adding 4-6 g of β-cyclodextrin into dimethyl sulfoxide, and dissolving to obtain a uniform solution A;

[0030] Step 2, adding 0.6-1.0 g of o-iodobenzoic acid into dimethyl sulfoxide, and dissolving to obtain a uniform solution B;

[0031] Step 3, adding solution B dropwise into solution A, reacting for 24-48 hours to obtain solution C;

[0032] Step 4, adding acetone to solution C to obtain a precipitate, and filtering to obtain powder D;

[0033] Step 5, after washing the powder D 2-3 times, dialdehyde cyclodextrin (DACD) is obtained.

[0034] It can be seen from the above description of the present invention that, compared with the prior art, the present invention has the following advantages:

[0035] 1. The technical solution to be protected in this application adopts multiple antibacterial technologies, as follows:

[0036] 1) The first antibacterial process (retanning process):

[0037] Eucalyptus oil and dialdehyde cyclodextrin (DACD) inclusion compound is used as a retanning agent. The aldehyde group on dialdehyde cyclodextrin (DACD) can cross-link with the collagen in the leather to achieve a retanning effect, improve the firmness and durability of the leather, and at the same time, the included eucalyptus oil has an antibacterial effect, and the sustained release effect formed by the inclusion can prolong its durability. At the same time, the inclusion compound of eucalyptus oil and dialdehyde cyclodextrin (DACD) is used as a filler in the filling process, which can also improve its long-term antibacterial performance.

[0038] 2) Second antibacterial (antibacterial treatment):

[0039] The modified antibacterial agent EO / β-CD is prepared by using essential oil (EO) extracted from eucalyptus leaves and β-cyclodextrin (β-CD) inclusion technology. It is added in the later stage of wet finishing to give crust leather antibacterial properties. Eucalyptus oil has natural antibacterial properties, and the inclusion of β-cyclodextrin (β-CD) can improve the stability and sustained release effect of eucalyptus oil, so that it can play a long-lasting antibacterial role in leather.

[0040] 3) The third antibacterial process (coating process):

[0041] Silver ions are used as antibacterial agents. Silver ions have broad-spectrum antibacterial properties and can effectively inhibit the growth of bacteria, fungi and viruses, thereby improving the antibacterial properties of leather.

[0042] 2. The multiple antibacterial technology of this application has broad-spectrum antibacterial properties, and through the integration of chemically modified cyclodextrin, natural plant essential oils and silver ions, effective protection against a variety of microorganisms is achieved. The long-lasting antibacterial property of this application is due to the inclusion technology of β-cyclodextrin, which helps the sustained release of eucalyptus oil, combined with the long-lasting antibacterial effect of silver ions, to ensure that the leather maintains its antibacterial properties for a long time. In addition, the invention emphasizes environmental protection and safety, using natural plant essential oils to reduce environmental pollution, and the use of silver ions poses a low risk to human health under proper control. Process compatibility ensures the effective application of antibacterial agents in different stages of wet dyeing and finishing of leather, and seamlessly connects with existing production processes. This solution not only improves the antibacterial properties of leather, but also optimizes its physical properties such as firmness, softness and fullness. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a comparison diagram between the multi-antibacterial leather of the present invention and ordinary antibacterial leather. DETAILED DESCRIPTION

[0044] The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0045] Embodiment 1:

[0046] A method for preparing leather with multiple antibacterial and long-lasting antibacterial functions, comprising the following steps: wet blue leather pretreatment → antibacterial retanning → filling and dyeing → fatliquoring → antibacterial treatment → drying and finishing → antibacterial coating;

[0047] Blue wet leather pretreatment: squeeze, stretch and shave the blue wet leather, weigh it, and use 130% of the weight to determine the weight of the chemical materials used in the subsequent treatment steps; then put the shaved blue wet leather into a drum and perform rewetting and neutralization treatment according to conventional processes;

[0048] Antibacterial retanning: add 200% water and 3.0% eucalyptus oil / dialdehyde cyclodextrin (DACD) inclusion complex into the drum, adjust the temperature inside the drum to 30°C, and rotate for 30 minutes; then add 4.0% chromium powder (Brother Technology Co., Ltd.), 2.0% chromium-containing tannin (BITAN BO of Tiger Company), 1.5% pickling oil (COTR B1 of Qiangde Company), and rotate for 60 minutes; add 1.5% sodium formate (Inner Mongolia Yihua Chemical Co., Ltd., and then add 1.0% eucalyptus oil / dialdehyde cyclodextrin (DACD), and rotate for 20 minutes; finally add 0.8% baking soda (Tianjin Bohai Yongli Chemical Co., Ltd.), rotate for 60 minutes, adjust the pH of the bath liquid to 4.2, stop the drum overnight, and drain the liquid after rotating for 30 minutes the next day;

[0049] Filling and dyeing: the amount of reagents used is calculated based on 150% of the weight of the wet blue leather after shaving. 100% of water, 4.0% of polymer retanning agent (TRUPOTAN R83 of Tompler), and 1.5% of fatliquor (TRUPON V2 of Tompler) are added to the drum, and rotated for 60-80 minutes; then 4.0% of melamine resin retanning agent (TRUPOTAN HB of Tompler), 4.0% of phenolic tannin (UKATAN SLH of Sidon Chemical Co., Ltd.), 4.0% of dicyandiamide resin retanning agent (BITAN R19 of Unitek), and 4.0% of synthetic tanning agent (Temper's TRUPON V2 of Lanxess, Germany) are added. PSW-C01liquid), 4.0% white tannin (W1 from Tompler), 0.3% eucalyptus oil / dialdehyde cyclodextrin (DACD) inclusion complex, rotate for 30-40 minutes, rotate for 30-40 minutes;

[0050] Fat-liquoring: The reagent dosage is calculated based on 120% of the weight of the wet blue leather after shaving. Add 2.0% dye (2BN from Aosheng Company) into the drum, rotate for 60 minutes, and check the cut; add 100% hot water at a temperature of 50°C and 2.5% protein filler (Desel Company's FB), rotate for 10 minutes; then add 4.0% fatliquor (TRUPONV2 of Tumblr), 2.0% fatliquor (HFW of Kekai), 2.0% neat's foot oil (BITOIL OPE of Unitek), 2.0% synthetic fatliquor (TANNIT LSW of Zhihui Co., Ltd.), rotate for 60 minutes, and check the dyeing;

[0051] Step 5, antibacterial treatment, the amount of reagent used is calculated as 150% of the weight of the wet blue leather after shaving, 2.0% eucalyptus oil / β-cyclodextrin (β-CD) inclusion compound is added to the drum, and the drum is rotated for 120 minutes; then 2.5% formic acid (BASF Chemical Co., Ltd.) is added twice, the pH of the bath is adjusted to 3.0-3.2, washed with water, and discharged from the drum; then dried, softened, and calendered according to conventional processes;

[0052] Antibacterial coating, including the following steps: primer → calendering → top coating → calendering → top coating → ironing → finished product;

[0053] Primer 3 times, total coating weight 15g / SF; topcoat 2 times, total coating weight 10 / SF;

[0054] The base coating and top coating formula are: 250 parts of water, 80 parts of water-based polyurethane 991-RU (Stahl Company), 80 parts of water-soluble protein (77-616), 80 parts of non-ionic oil 388-FO (Stahl Company), 80 parts of water-based wax emulsion 417-FI (Stahl Company), 25 parts of auxiliary agent HF (Stahl Company); 3% of nanosilver aqueous dispersion (particle size <20nm, concentration ≥1000ppm).

[0055] Top coat twice, total coating amount 4g / SF;

[0056] The top coating formula is: 200 parts of water, 50 parts of water-based polyurethane 905-WT (Stahl), 20 parts of water-soluble protein 77-616 (Stahl), 50 parts of non-ionic oil 388-FO (Stahl), 50 parts of water-based wax emulsion 417-FI (Stahl), 3 parts of hand feeling agent HM-443 (Stahl), 5% of nanosilver aqueous dispersion (particle size <20nm, concentration ≥1000ppm).

[0057] Embodiment 2:

[0058] A method for preparing leather with multiple antibacterial and long-lasting antibacterial functions, comprising the following steps: wet blue leather pretreatment → antibacterial retanning → filling and dyeing → fatliquoring → antibacterial treatment → drying and finishing → antibacterial coating;

[0059] Blue wet leather pretreatment: squeeze, stretch and shave the blue wet leather, weigh it, and use 130% of the weight to determine the weight of the chemical materials used in the subsequent treatment steps; then put the shaved blue wet leather into a drum and perform rewetting and neutralization treatment according to conventional processes;

[0060] Antibacterial retanning: add 150% water and 2.5% eucalyptus oil / dialdehyde cyclodextrin (DACD) inclusion complex into the drum, adjust the temperature inside the drum to 30°C, and rotate for 30 minutes; then add 3.0% chromium powder (Brother Technology Co., Ltd.), 3.0% chromium-containing tannin (BITAN BO of Tiger Company), 1.0% pickling oil (COTR B1 of Qiangde Company), and rotate for 60 minutes; add 1.0% sodium formate (Inner Mongolia Yihua Chemical Co., Ltd., and then add 2.0% eucalyptus oil / dialdehyde cyclodextrin (DACD), and rotate for 20 minutes; finally add 1.0% baking soda (Tianjin Bohai Yongli Chemical Co., Ltd.), rotate for 60 minutes, adjust the pH of the bath liquid to 4.2, stop the drum overnight, and drain the liquid after rotating for 30 minutes the next day;

[0061] Filling and dyeing: the amount of reagents used is calculated based on 130% of the weight of the wet blue leather after shaving. Add 80% of water, 3.0% of polymer retanning agent (TRUPOTAN R83 of Tompler), and 1.0% of fatliquor (TRUPON V2 of Tompler) into the drum and rotate for 60-80 minutes; then add 3.0% of melamine resin retanning agent (TRUPOTAN HB of Tompler), 3.0% of phenolic tannin (UKATAN SLH of Seaton Chemical Co., Ltd.), 3.0% of dicyandiamide resin retanning agent (BITAN R19 of Unitek), and 3.0% of synthetic tanning agent (Temper's TRUPON V2 of Lanxess, Germany) PSW-C01liquid), 3.0% white tannin (W1 from Tompler), 0.5% eucalyptus oil / dialdehyde cyclodextrin (DACD) inclusion complex, rotate for 30-40 minutes, rotate for 30-40 minutes;

[0062] Fat-liquoring: The reagent dosage is calculated based on 130% of the weight of the wet blue leather after shaving. Add 2.0% dye (2BN from Aosheng Company) into the drum, rotate for 60 minutes, and check the cut; add 100% hot water at a temperature of 50°C and 2.0% protein filler (Desel Company's FB), rotate for 10 minutes; then add 3.0% fatliquor (TRUPONV2 of Tumblr), 3.0% fatliquor (HFW of Kekai), 3.0% neat's foot oil (BITOIL OPE of Unitek), 3.0% synthetic fatliquor (TANNIT LSW of Zhihui Co., Ltd.), rotate for 60 minutes, and check the dyeing;

[0063] Step 5, antibacterial treatment, the amount of reagent used is calculated as 130% of the weight of the wet blue leather after shaving, 3.0% eucalyptus oil / β-cyclodextrin (β-CD) inclusion compound is added to the drum, and the drum is rotated for 120 minutes; then 3.0% formic acid (BASF Chemical Co., Ltd.) is added twice, the pH of the bath is adjusted to 3.0-3.2, washed with water, and discharged from the drum; then dried, softened, and calendered according to conventional processes;

[0064] The antibacterial coating comprises the following steps: primer coating→calendering→top coating→calendering→top coating→ironing→finished product; the primer coating and top coating formula are: 350 parts of water, 100 parts of waterborne polyurethane 991-RU (Stahl Company), 100 parts of water-soluble protein (77-616), 100 parts of non-ionic oil 388-FO (Stahl Company), 100 parts of waterborne wax emulsion 417-FI (Stahl Company), 25 parts of auxiliary agent HF (Stahl Company); 3% of nano silver aqueous dispersion (particle size <20nm, concentration ≥1000ppm); primer coating 3 times, total coating amount 15g / SF; top coating 2 times, total coating amount 10 / SF.

[0065] The top coating formula is: 300 parts of water, 100 parts of water-based polyurethane 905-WT (Stahl), 50 parts of water-soluble protein 77-616 (Stahl), 100 parts of non-ionic oil 388-FO (Stahl), 100 parts of water-based wax emulsion 417-FI (Stahl), 5 parts of hand feeling agent HM-443 (Stahl), 5% of nano-silver aqueous dispersion (particle size <20nm, concentration ≥1000ppm); top coating 2 times, total coating amount 4g / SF.

[0066] The multi-antibacterial leather prepared by the technical solution of the present application and the ordinary antibacterial leather were tested after being stored for 90 days, and the details are as follows:

[0067] The antibacterial performance is tested according to GB / T 21510-2008, and the antibacterial rate (%) is tested, and the Gram-negative bacteria Escherichia coli (E. coli) and positive bacteria Staphylococcus aureus (S. aureus) are selected. The anti-mildew performance is tested according to GB / T1741-2020, and the mold growth area (%) is tested, and the mold is Aspergillus flavus.

[0068] Table 1 Antibacterial and antifungal test table

[0069]

[0070] As shown in the attached figure of the instruction manual Figure 1 As shown, the left picture is ordinary antibacterial leather, and the right picture is multiple antibacterial leather. The test results show that the multiple antibacterial leather made using patented technology has better antibacterial properties than ordinary antibacterial leather.

[0071] The above is only a specific implementation of the present invention, but the design concept of the present invention is not limited to this. Any non-substantial changes to the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A method for preparing leather with multiple antibacterial and long-lasting antibacterial functions, characterized in that: The process includes the following steps: wet blue leather pretreatment → antibacterial retanning → filling and dyeing → fatliquoring → antibacterial treatment → drying and finishing → antibacterial coating; Wet blue leather pretreatment: squeeze and stretch the wet blue leather, shave it, weigh it, and use 120-150% of the weight of the wet blue leather to determine the weight of the chemical materials used in the subsequent treatment steps; then put the shaved wet blue leather into a drum for rewetting and neutralization treatment; Antibacterial retanning: add 150-200% water and 2.0-3.0% eucalyptus oil-dialdehyde cyclodextrin into a rotating drum, adjust the temperature inside the drum to 30-40°C, and rotate for 20-30 minutes; then add 3.0-4.0% chromium powder, 2.0-3.0% chromium-containing tannin, and 1.0-1.5% pickling oil, and rotate for 60-80 minutes; add 1.0-1.5% sodium formate again, and then add 1.0-2.0% eucalyptus oil-dialdehyde cyclodextrin, and rotate for 20 minutes; finally add 0.8-1.0% baking soda, rotate for 40-60 minutes, adjust the pH of the bath liquid to 4.0-4.3, stop the drum overnight, rotate for 20-30 minutes the next day and then drain; Antibacterial treatment: the dosage of the reagent is calculated as 120-150% of the weight of the wet blue leather after shaving, 2.0-3.0% of eucalyptus oil and β-cyclodextrin inclusion compound are added to the drum, and the drum is rotated for 60-120 minutes; then 2.5-3.0% of formic acid is added twice, the pH value of the bath liquid is adjusted to 3.0-3.2, washed with water, and discharged from the drum; then dried, softened, and calendered.

2. The method for preparing leather with multiple antibacterial and long-lasting antibacterial functions as claimed in claim 1, characterized in that: The preparation of the inclusion compound of β-cyclodextrin and eucalyptus oil comprises the following steps: Step 1, adding 1-10 g of eucalyptus oil to deionized water, and stirring the mixture magnetically to obtain a eucalyptus oil solution; Step 2, taking the eucalyptus oil solution, adding 80-100 g of β-cyclodextrin, stirring evenly at 30-50° C., and reacting for 4-8 hours to make the eucalyptus oil and β-cyclodextrin aqueous solution system uniform; Step 3, placing the eucalyptus oil and β-cyclodextrin aqueous solution under refrigeration conditions to form a stable inclusion complex solution overnight; Step 4, placing the inclusion complex solution in a suction filter to obtain inclusion complex crystals, and drying them in a vacuum drying oven at 50-60° C. for 2-3 hours to obtain an inclusion complex of β-cyclodextrin and eucalyptus oil.

3. The method for preparing leather with multiple antibacterial and long-lasting antibacterial functions as claimed in claim 1, characterized in that: The preparation of the inclusion compound of dialdehyde cyclodextrin and eucalyptus oil comprises the following steps: Step 1, adding 1-10 g of eucalyptus oil to deionized water, and stirring the mixture magnetically to obtain a eucalyptus oil solution; Step 2, taking the eucalyptus oil solution, adding 80-100g of dialdehyde cyclodextrin, stirring evenly at 30-50°C, and reacting for 4-8h to make the eucalyptus oil and dialdehyde cyclodextrin aqueous solution system uniform; Step 3, placing the eucalyptus oil and dialdehyde cyclodextrin aqueous solution under refrigeration conditions to form a stable inclusion complex solution overnight; Step 4, placing the inclusion complex solution in a suction filter to obtain eucalyptus oil-dialdehyde cyclodextrin crystals, and drying them in a vacuum drying oven at 50-60° C. for 2-3 hours to obtain an inclusion complex of dialdehyde cyclodextrin and eucalyptus oil.

4. The method for preparing leather with multiple antibacterial and long-lasting antibacterial functions as claimed in claim 1, characterized in that: The preparation of the dialdehyde cyclodextrin comprises the following steps: Step 1, add 4-6 g of β-cyclodextrin into dimethyl sulfoxide and dissolve to obtain a uniform solution A; Step 2, adding 0.6-1.0 g of o-iodobenzoic acid into dimethyl sulfoxide, and dissolving to obtain a uniform solution B; Step 3, adding solution B dropwise into solution A, reacting for 24-48 hours to obtain solution C; Step 4, adding acetone to solution C to obtain a precipitate, and filtering to obtain powder D; Step 5, after washing the powder D 2-3 times, dialdehyde cyclodextrin is obtained.

5. The method for preparing leather with multiple antibacterial and long-lasting antibacterial functions as claimed in claim 1, characterized in that: The filling dyeing process comprises the following steps: the dosage of the reagent is calculated as 120-150% of the weight of the wet blue leather after shaving, 80-100% of water, 3.0-4.0% of a polymer retanning agent, and 1.0-1.5% of a fatliquor is added into a rotating drum, and the drum is rotated for 60-80 minutes; then 3.0-4.0% of a melamine resin retanning agent, 3.0-4.0% of phenolic tannins, 3.0-4.0% of a dicyandiamide resin retanning agent, 3.0-4.0% of a synthetic tanning agent, 3.0-4.0% of white tannin, and 0.3-0.5% of a eucalyptus oil-dialdehyde cyclodextrin inclusion compound are added, and the drum is rotated for 30-40 minutes.

6. The method for preparing leather with multiple antibacterial and long-lasting antibacterial functions as claimed in claim 1, characterized in that: The fatliquor comprises the following steps: the dosage of the reagent is calculated as 120-150% of the weight of the wet blue leather after shaving, 2.0-3.0% of the dye is added into the drum, the drum is rotated for 40-60 minutes, and the cut is checked; 100-150% of hot water at a temperature of 50°C and 2.0-2.5% of protein filler are added, the drum is rotated for 10-20 minutes; 3.0-4.0% of the fatliquor, 3.0-4.0% of the fatliquor, 2.0-3.0% of neatsfoot oil and 2.0-3.0% of the synthetic fatliquor are added, the drum is rotated for 60-80 minutes, and the dyeing is checked.

7. The method for preparing leather with multiple antibacterial and long-lasting antibacterial functions as claimed in claim 1, characterized in that: The coating process includes the following steps: primer coating → calendering → top coating → calendering → top coating → ironing → finished product; The primer is applied 2-3 times, with a total coating amount of 10-20g / SF; the topcoat is applied 2-3 times, with a total coating amount of 8-12g / SF; the primer formula is: 250-350 parts of water, 80-100 parts of cationic polyurethane, 80-100 parts of cationic casein, 180-250 parts of non-ionic oil wax mixture, 25 parts of cationic paint; 1-5% of nano silver aqueous dispersion; Top coat 1-2 times, total coating amount 2-5g / SF; The top coating formula is: 200-300 parts of water, 50-100 parts of cationic polyurethane, 20-50 parts of cationic casein, 80-150 parts of non-ionic oil wax, and 1-5% of nano silver aqueous dispersion.

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