An epoxy coating for waterproof and wear-resistant leather, its preparation process and application

Abstract

The present invention provides a waterproof and wear-resistant epoxy coating for leather, its preparation process and application, including the following steps: (1) Weigh raw materials according to parts by mass: 13-17 parts of modified filler, 50-55 parts of epoxy resin, 15-20 parts of polymer, 40-45 parts of polythiol curing agent, 0.2-0.4 parts of antioxidant, 0.1-0.3 parts of defoaming agent, 0.3-0.5 parts of dispersant, 0.2-0.5 parts of leveling agent; (2) Conduct the first mixing of epoxy resin, polymer and modified filler to obtain a first mixture; (3) Sequentially add antioxidant, defoaming agent, dispersant and leveling agent to the first mixture for the second mixing to obtain a second mixture; (4) Mix the second mixture with the polythiol curing agent to obtain a waterproof and wear-resistant epoxy coating for leather. The epoxy coating of the present invention has excellent waterproof and wear-resistant properties, excellent comprehensive properties, and high thermal storage stability, and can be used for preparing leather products.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings, and particularly relates to a waterproof and wear-resistant epoxy coating for leather, its preparation process and application. Background Art

[0002] Leather finishing is a key step in the leather manufacturing process. It involves various physical and chemical treatments on leather to improve its appearance, feel and functional properties. The purpose of leather finishing is to make leather more beautiful, durable and endow it with specific properties such as waterproof, oil-proof, stain-resistant, soft, shiny, etc. Leather coatings are special coatings mainly used for the surface treatment of leather products to enhance their wear resistance, waterproofness and aesthetics. Such coatings are mainly composed of resins, curing agents and some additives. When applied to leather and cured, they will form a tough protective film.

[0003] Epoxy resin coatings are a commonly used leather finishing product, which can firmly adhere to the leather surface and form a durable protective layer. However, epoxy resin coatings also have some disadvantages in the application scenario of leather finishing: (1) Flexibility problem: Compared with the natural elasticity of leather, the epoxy resin coating may be relatively hard, resulting in the loss of the original softness and comfort of the leather. (2) Waterproof and wear resistance: Epoxy resin coatings may affect the wear resistance of leather, and at the same time, the waterproofness is not good, which is a disadvantage for leather products (such as shoes) that need to maintain their service life. (3) Curing process: Epoxy resin needs to be mixed with a curing agent and requires a certain time to cure, and this process may not be suitable for the leather products industry with rapid production.

[0004] The coatings on the surface of leather shoes are mainly to improve and protect the leather surface, enhancing the appearance and durability of the shoes. The coatings can make the color of leather shoes more vivid and uniform, achieving the visual effect desired by the designer. At the same time, the coatings can give leather shoes a shiny feeling. For example, patent leather shoes obtain high gloss by coating resin coatings. The coatings form a protective film, which can prevent moisture and stains from penetrating into the leather interior, extending the service life of leather shoes. The coatings can enhance the wear resistance of leather, reducing scratches and abrasions during daily use. At the same time, the coatings can be used to cover small defects on the leather surface, such as scratches, spots, etc., helping to maintain the shape and structure of the leather and prevent deformation.

[0005] Therefore, there is an urgent need for an epoxy coating with good waterproof, wear resistance and flexibility, which is of great significance for the production and development of leather products. Summary of the Invention

[0006] The purpose of the present invention is to provide a waterproof and wear-resistant epoxy coating for leather, its preparation process and application.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] Preparation process of an epoxy coating for waterproof and wear-resistant leather, comprising the following steps:

[0009] (1) Weigh raw materials by mass parts: 13 - 17 parts of modified filler, 50 - 55 parts of epoxy resin, 15 - 20 parts of polymer, 40 - 45 parts of polythiol curing agent, 0.2 - 0.4 part of antioxidant, 0.1 - 0.3 part of defoaming agent, 0.3 - 0.5 part of dispersant, and 0.2 - 0.5 part of leveling agent;

[0010] The epoxy resin is a mixture of NPEL - 128 type epoxy resin and NPEL - 128S type epoxy resin with a mass ratio of 2.4 - 2.8:1;

[0011] The preparation method of the polymer is as follows: by mass parts,

[0012] Step 1: Dissolve 400 - 420 parts of isophorone diisocyanate in 1500 parts of N - methylpyrrolidone, heat to 52 - 55 °C, add 1200 - 1250 parts of polypropylene glycol, and react at 52 - 55 °C for 3 - 5 h to obtain an isocyanate - terminated first intermediate;

[0013] Step 2: Dissolve 400 - 420 parts of diaminodiphenylmethane in 900 parts of N - methylpyrrolidone, heat to 52 - 55 °C, add 180 - 200 parts of toluene diisocyanate, and react at 52 - 55 °C for 3 - 5 h to obtain an amine - terminated second intermediate;

[0014] Step 3: Add 1450 - 1480 parts of the first intermediate to 750 - 770 parts of the second intermediate, mix evenly, and react at 80 - 84 °C for 3 - 4 h to obtain the polymer;

[0015] (2) First - mix the epoxy resin, polymer, and modified filler to obtain a first mixture;

[0016] (3) Sequentially add the antioxidant, defoaming agent, dispersant, and leveling agent to the first mixture for second - mixing to obtain a second mixture;

[0017] (4) Mix the second mixture and the polythiol curing agent to obtain the epoxy coating for waterproof and wear - resistant leather.

[0018] Both NPEL - 128 type epoxy resin and NPEL - 128S type epoxy resin are purchased from Nan Ya Plastics Industry Co., Ltd.

[0019] The epoxy resin of model NPEL-128 produced by Nan Ya Plastics Industry Co., Ltd. is a liquid epoxy resin formed by the reaction of bisphenol A and epichlorohydrin. It is a resin commonly used in leather coatings. During daily wear, leather shoes are inevitably subject to friction and bumps, and high abrasion resistance of the coating helps to maintain the beauty of the shoe upper. However, the abrasion resistance of the coating using NPEL-128 epoxy resin is not ideal. In the present invention, NPEL-128 epoxy resin is compounded with NPEL-128S epoxy resin and a polymer, which can improve the abrasion resistance of the coating. The analysis is that the mixing of resins with different epoxy equivalents can adjust the crosslinking density of the final cured product, thereby improving the abrasion resistance of the coating. At the same time, the addition of a polymer with a combination of hard and soft segments to the epoxy resin can improve the crosslinking network structure of the epoxy resin, forming a more complex three-dimensional network, and this network structure can better resist wear. The inventor also found that under these conditions, the tensile strength of the epoxy coating is improved.

[0020] Furthermore, the preparation method of the modified filler is as follows:

[0021] (1) Calcinate the mixed filler at a temperature of 800 - 900 °C for 40 - 60 minutes to obtain the calcined mixed filler; the mixed filler is a mixture of nano samarium oxide, boron nitride and organic bentonite with a mass ratio of 1:0.2 - 0.6:1.2 - 1.5.

[0022] (2) Crush the calcined mixed filler and grind it into a mixed filler powder with a mesh size of 80 - 100.

[0023] (3) Mix the mixed filler powder, tetramethylammonium bromide and ethanol aqueous solution according to a mass ratio of 10:1 - 1.2:80 - 100, stir evenly, heat at a temperature of 55 - 60 °C for 3 - 5 hours, filter, and dry to obtain the modified mixed filler.

[0024] Furthermore, the mass percentage concentration of the ethanol aqueous solution is 65 - 70%.

[0025] The inventors found that after adding polymers to the coating system, when leather shoes are worn and the upper is bent, cracks are more likely to form at the creases. These cracks not only affect the appearance but also gradually expand, leading to greater damage. Analysis shows that the ratio of hard and soft segments in the coating affects the elasticity of the coating and cannot adapt to the bending and stretching of leather during wearing or use. The inventors tried to add mixed fillers to improve the fold resistance of epoxy coatings, but the effect was not ideal. Through a large number of experiments, it was found that in the present invention, by modifying the mixed fillers, the fold resistance of epoxy coatings can be improved. The analysis is that the mixed fillers modified with tetrabutylammonium bromide have hydrophobicity, which can improve their dispersion in the organic matrix, thus forming a more uniform distribution in epoxy resin and polymers. The layered structure of the mixed fillers can expand after modification, allowing epoxy resin and polymer molecules to insert into the interlayer, which can increase the flexibility of the coating without sacrificing strength. At the same time, under this condition, the water resistance and thermal storage stability of the coating are improved.

[0026] Furthermore, the polythiol curing agent is GLC-905 polythiol curing agent. It is purchased from Shandong Suihua Biotechnology Co., Ltd.

[0027] After the present invention uses the polythiol curing agent and epoxy resin in a ratio, it can achieve rapid gel curing at low temperature and with a relatively thin coating film, and has obvious advantages over other curing agents in rapid repair, winter, and low-temperature operation occasions.

[0028] Furthermore, the antioxidant is selected from at least one of antioxidant 1010, antioxidant 168, antioxidant BHT, and antioxidant 330.

[0029] Furthermore, the defoaming agent is selected from at least one of Degussa TEGO901W defoaming agent, Degussa TEGO902W defoaming agent, and Degussa TEGO801W defoaming agent.

[0030] Furthermore, the dispersant is selected from at least one of TEGODi spers715w, TEGODi spers755w, and TEGOWet280.

[0031] Furthermore, the leveling agent is selected from at least one of BYK300, BYK306, and BYK333.

[0032] The present invention also provides the epoxy coating prepared by the above preparation process.

[0033] The present invention also provides the application of the epoxy coating in the preparation of leather products.

[0034] Furthermore, the application of the epoxy coating in the preparation of leather shoes.

[0035] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0036] 1. The present invention provides an epoxy coating for leather with waterproof and wear-resistant properties, its preparation process and application. The epoxy coating has excellent waterproof and wear-resistant properties, excellent comprehensive properties, high thermal storage stability, and can be used to prepare leather products.

[0037] 2. The epoxy resin of model NPEL-128 produced by Nan Ya Plastics Industry Co., Ltd. is a liquid epoxy resin formed by the reaction of bisphenol A and epichlorohydrin, and is a resin commonly used in leather coatings. However, the wear resistance of the NPEL-128 epoxy resin coating is not ideal. In the present invention, the NPEL-128 epoxy resin is compounded with the NPEL-128S epoxy resin and a polymer, which can improve the wear resistance of the coating. The tensile strength of the epoxy coating is improved.

[0038] 3. The inventors found that after adding a polymer to the coating system, when wearing leather shoes, when the upper surface is bent, cracks are more likely to form at the crease. These cracks not only affect the appearance, but also gradually expand, resulting in greater damage. The analysis is that the ratio of the hard and soft segments in the coating affects the elasticity of the coating and cannot adapt to the bending and stretching of the leather during wearing or use. In the present invention, by modifying the mixed filler, the fold resistance of the epoxy coating can be improved. At the same time, under this condition, the water resistance and thermal storage stability of the coating are improved. Specific Embodiments

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] Some raw materials of the embodiments are purchased from the following manufacturers:

[0041] The particle size of nano samarium oxide is 40-60 nm. Zhejiang Zhitaina Micro New Materials Co., Ltd.

[0042] Boron nitride, average particle size 100 nm, specific surface area 10-20 m 2 / g. Zhejiang Zhitaina Micro New Materials Co., Ltd.

[0043] Organic bentonite: 94 wt% can pass through a 200-mesh sieve. BYK-Chemie organically modified bentonite BENTONE EW-NA.

[0044] Example 1

[0045] This example provides an epoxy coating for leather with waterproof and wear-resistant properties, and its preparation process includes the following steps:

[0046] (1) Weigh the raw materials by mass parts: 15 parts of modified filler, 52 parts of epoxy resin, 17 parts of polymer, 43 parts of polythiol curing agent, 0.3 parts of antioxidant, 0.2 parts of defoaming agent, 0.4 parts of dispersant, and 0.3 parts of leveling agent;

[0047] The epoxy resin is a mixture of NPEL-128 type epoxy resin and NPEL-128S type epoxy resin with a mass ratio of 2.6:1;

[0048] The preparation method of the polymer is as follows: by mass parts,

[0049] Step 1: Dissolve 410 parts of isophorone diisocyanate in 1500 parts of N-methylpyrrolidone, heat to 53 °C, add 1220 parts of polypropylene glycol, and react at 53 °C for 4 h to obtain an isocyanate-terminated first intermediate;

[0050] Step 2: Dissolve 410 parts of diaminodiphenylmethane in 900 parts of N-methylpyrrolidone, heat to 53 °C, add 190 parts of toluene diisocyanate, and react at 53 °C for 4 h to obtain an amine-terminated second intermediate;

[0051] Step 3: Add 1470 parts of the first intermediate to 760 parts of the second intermediate, mix evenly, and react at 82 °C for 3.5 h to obtain the polymer;

[0052] (2) First mix the epoxy resin, polymer and modified filler to obtain a first mixture;

[0053] (3) Add the antioxidant, defoaming agent, dispersant, and leveling agent to the first mixture in sequence for a second mixing to obtain a second mixture;

[0054] (4) Mix the second mixture and the polythiol curing agent to obtain a waterproof and wear-resistant epoxy coating for leather.

[0055] Both NPEL-128 type epoxy resin and NPEL-128S type epoxy resin are purchased from Nan Ya Plastics Industry Co., Ltd.

[0056] The preparation method of the modified filler is as follows:

[0057] (1) Calcinate the mixed filler at a temperature of 850 °C for 50 minutes to obtain the calcined mixed filler; the mixed filler is a mixture of nano samarium oxide, boron nitride and organic bentonite with a mass ratio of 1:0.4:1.3;

[0058] (2) Crush the calcined mixed filler and grind it into a mixed filler powder with a mesh size of 80-100;

[0059] (3) Mix the mixed filler powder, tetrabutylammonium bromide, and ethanol aqueous solution according to a mass ratio of 10:1.1:90, stir evenly, heat at 57 °C for 4 hours, filter, and dry to obtain the modified mixed filler.

[0060] The mass percentage concentration of the ethanol aqueous solution is 70%.

[0061] The polythiol curing agent is GLC-905 polythiol curing agent. It is purchased from Shandong Suihua Biotechnology Co., Ltd.

[0062] The antioxidant is antioxidant 1010.

[0063] The defoaming agent is Degussa TEGO901W defoaming agent.

[0064] The dispersant is TEGODispers715w.

[0065] The leveling agent is BYK300.

[0066] Example 2

[0067] This example provides a waterproof and wear-resistant epoxy coating for leather, and its preparation process includes the following steps:

[0068] (1) Weigh the raw materials by mass parts: 17 parts of modified filler, 55 parts of epoxy resin, 15 parts of polymer, 45 parts of polythiol curing agent, 0.2 part of antioxidant, 0.3 part of defoaming agent, 0.3 part of dispersant, and 0.5 part of leveling agent;

[0069] The epoxy resin is a mixture of NPEL-128 type epoxy resin and NPEL-128S type epoxy resin with a mass ratio of 2.4:1;

[0070] The preparation method of the polymer is as follows: by mass parts,

[0071] Step 1: Dissolve 420 parts of isophorone diisocyanate in 1500 parts of N-methylpyrrolidone, heat to 52 °C, add 1200 parts of polypropylene glycol, and react at 52 °C for 5 h to obtain an isocyanate-terminated first intermediate;

[0072] Step 2: Dissolve 400 parts of diaminodiphenylmethane in 900 parts of N-methylpyrrolidone, heat to 52 °C, add 180 parts of toluene diisocyanate, and react at 52 °C for 5 h to obtain an amine-terminated second intermediate;

[0073] Step 3: Add 1450 parts of the first intermediate to 750 parts of the second intermediate, mix evenly, and react at 80 °C for 4 h to obtain the polymer;

[0074] (2) First, mix epoxy resin, polymer, and modified filler to obtain a first mixture;

[0075] (3) Sequentially add antioxidant, defoamer, dispersant, and leveling agent to the first mixture and conduct a second mixing to obtain a second mixture;

[0076] (4) Mix the second mixture with polythiol curing agent to obtain a waterproof and wear-resistant epoxy coating for leather.

[0077] Both NPEL-128 type epoxy resin and NPEL-128S type epoxy resin are purchased from Nan Ya Plastics Industry Co., Ltd.

[0078] The preparation method of the said modified filler is as follows:

[0079] (1) Calcinate the mixed filler at a temperature of 900 °C for 40 minutes to obtain the calcined mixed filler; the mixed filler is a mixture of samarium oxide nanoparticles, boron nitride, and organic bentonite with a mass ratio of 1:0.6:1.2;

[0080] (2) Crush the calcined mixed filler and grind it into a mixed filler powder with a mesh size of 80 - 100;

[0081] (3) Mix the mixed filler powder, tetrabutylammonium bromide, and ethanol aqueous solution according to a mass ratio of 10:1.3:100, stir evenly, heat at a temperature of 60 °C for 3 hours, filter, and dry to obtain the modified mixed filler.

[0082] The mass percentage concentration of the said ethanol aqueous solution is 65%.

[0083] The polythiol curing agent is GLC-905 polythiol curing agent, purchased from Shandong Suihua Biotechnology Co., Ltd.

[0084] The said antioxidant is antioxidant 168.

[0085] The said defoamer is Degussa TEGO902W defoamer.

[0086] The said dispersant is TEGO Dispers755w.

[0087] The said leveling agent is BYK306.

[0088] Example 3

[0089] This example provides a waterproof and wear-resistant epoxy coating for leather, and its preparation process includes the following steps:

[0090] (1) Weigh the raw materials by mass parts: 13 parts of modified filler, 50 parts of epoxy resin, 15 parts of polymer, 40 parts of polythiol curing agent, 0.2 parts of antioxidant, 0.1 parts of defoamer, 0.3 parts of dispersant, and 0.2 parts of leveling agent;

[0091] The epoxy resin is a mixture of NPEL-128 type epoxy resin and NPEL-128S type epoxy resin with a mass ratio of 2.8:1;

[0092] The preparation method of the polymer is as follows: by mass parts,

[0093] Step 1: Dissolve 400 parts of isophorone diisocyanate in 1500 parts of N-methylpyrrolidone, heat to 52 °C, add 1250 parts of polypropylene glycol, and react at 52 °C for 5 h to obtain an isocyanate-terminated first intermediate;

[0094] Step 2: Dissolve 420 parts of diaminodiphenylmethane in 900 parts of N-methylpyrrolidone, heat to 52 °C, add 200 parts of toluene diisocyanate, and react at 52 °C for 5 h to obtain an amine-terminated second intermediate;

[0095] Step 3: Add 1480 parts of the first intermediate to 770 parts of the second intermediate, mix evenly, and react at 80 °C for 4 h to obtain the polymer;

[0096] (2) First mix the epoxy resin, polymer, and modified filler to obtain a first mixture;

[0097] (3) Add the antioxidant, defoamer, dispersant, and leveling agent to the first mixture in sequence and perform a second mixing to obtain a second mixture;

[0098] (4) Mix the second mixture and the polythiol curing agent to obtain a waterproof and wear-resistant epoxy coating for leather.

[0099] Both NPEL-128 type epoxy resin and NPEL-128S type epoxy resin are purchased from Nan Ya Plastics Industry Co., Ltd.

[0100] The preparation method of the modified filler is as follows:

[0101] (1) Calcinate the mixed filler at a temperature of 850 °C for 50 minutes to obtain the calcined mixed filler; the mixed filler is a mixture of samarium oxide nanoparticles, boron nitride, and organic bentonite with a mass ratio of 1:0.6:1.3;

[0102] (2) Crush the calcined mixed filler and grind it into a mixed filler powder with a mesh size of 80-100;

[0103] (3) Mix the mixed filler powder, tetraethylammonium bromide, and ethanol aqueous solution in a mass ratio of 10:1:95. After stirring evenly, heat at a temperature of 57°C for 4 hours, filter, and dry to obtain the modified mixed filler.

[0104] The mass percentage concentration of the ethanol aqueous solution is 70%.

[0105] The polythiol curing agent is GLC-905 polythiol curing agent. Purchased from Shandong Suihua Biotechnology Co., Ltd.

[0106] The antioxidant is antioxidant 1010.

[0107] The defoaming agent is Degussa TEGO901W defoaming agent.

[0108] The dispersant is TEGODispers715w.

[0109] The leveling agent is BYK300.

[0110] Comparative Example 1

[0111] The difference between this comparative example and Example 1 is that the epoxy resin is a mixture of NPEL-128 type epoxy resin and NPEL-128S type epoxy resin in a mass ratio of 1:1.

[0112] Comparative Example 2

[0113] The difference between this comparative example and Example 1 is that the NPEL-128S type epoxy resin is replaced by NPEL-134 type epoxy resin. Purchased from Nan Ya Plastics Corporation.

[0114] Comparative Example 3

[0115] The difference between this comparative example and Example 1 is that the amounts of the polymer and the epoxy resin are different.

[0116] Weigh the raw materials by mass parts: 15 parts of modified filler, 44 parts of epoxy resin, 25 parts of polymer, 43 parts of polythiol curing agent, 0.3 part of antioxidant, 0.2 part of defoaming agent, 0.4 part of dispersant, and 0.3 part of leveling agent.

[0117] Comparative Example 4

[0118] The difference between this comparative example and Example 1 is that the polymer is replaced by NPEL-127 type epoxy resin. Purchased from Nan Ya Plastics Corporation.

[0119] Comparative Example 5

[0120] The difference between this comparative example and Example 1 is as follows: The preparation method of the modified filler is as follows: Mix the mixed filler, silane coupling agent KH560, and 70 wt% ethanol aqueous solution with a mass ratio of 1:0.02:8. The mixed filler is a mixture of nano samarium oxide, boron nitride, and organic bentonite with a mass ratio of 1:0.4:1.3. React at 70 °C for 6 h, filter, wash, and dry to obtain the modified filler.

[0121] Comparative Example 6

[0122] The difference between this comparative example and Example 1 is as follows: The mass ratio of nano samarium oxide, boron nitride, and organic bentonite is 1:1:1.

[0123] Comparative Example 7

[0124] The difference between this comparative example and Example 1 is as follows:

[0125] The particle size of nano samarium oxide is 100 - 150 nm. Zhejiang Zhitaina Micro New Materials Co., Ltd.

[0126] Boron nitride, average particle size 180 nm, specific surface area 4 - 7 m 2 / g. Zhejiang Zhitaina Micro New Materials Co., Ltd.

[0127] Organic bentonite: particle size ≤ 1 μm. Model: DECHEM HEMINGSWORTH BENTONE SD - 2 organic bentonite.

[0128] Performance testing

[0129] Perform performance testing on the coatings of Examples 1 - 3 and Comparative Examples 1 - 7:

[0130] 1. Tensile strength: GB / T2567 - 2008, 25 °C × 7 days (humidity 50%);

[0131] 2. Flexibility at room temperature: Refer to GB / T3903.41 - 2019, use a leather flexing tester, 23 °C, 100000 cycles;

[0132] 3. Flexibility at low temperature: Refer to GB / T3903.41 - 2019, use a leather flexing tester, - 10 °C, 50000 cycles;

[0133] 4. Friction value of the learning vibration mode: Test using a Japanese Yasuda (learning vibration mode) color fastness friction tester;

[0134] 5. Thermal storage stability: Thermal storage at 50 °C for 20 days.

[0135] 6. Water resistance: Spray the epoxy coating onto the surface of a cowhide embryo and let it stand at 50 °C for 2 h;

[0136] 7. The roll coating is as follows: roll coat the epoxy coating on the surface of the leather embryo, with a spraying amount of 8 g per square foot of the leather embryo, and then dry it. Then, refer to GJB2589.7-1996 to measure the number of water penetration times.

[0137] The performance test results of each example are shown in Table 1.

[0138] The performance test results of each example are shown in the content of Table 1.

[0139] Table 1 Performance Test Results

[0140]

[0141]

[0142] From the results, it can be seen that the epoxy coatings in Examples 1-2 have excellent comprehensive performance. When the preparation raw materials and conditions are changed, the performance decreases to varying degrees. From Comparative Example 3, it can be seen that when the polymer addition amount increases, the folding resistance of the coating decreases.

[0143] The above is the preferred implementation mode of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A process for preparing a waterproof and wear-resistant epoxy coating for leather, characterized in that: The following steps are involved: (1) Weigh the raw materials by mass: 13-17 parts of modified filler, 50-55 parts of epoxy resin, 15-20 parts of polymer, 40-45 parts of polythiol curing agent, 0.2-0.4 parts of antioxidant, 0.1-0.3 parts of defoaming agent, 0.3-0.5 parts of dispersant and 0.2-0.5 parts of leveling agent; The epoxy resin is a mixture of NPEL-128 epoxy resin and NPEL-128S epoxy resin in a mass ratio of 2.4-2.8:1; The preparation method of the polymer is as follows: by weight: Step 1: dissolving 400-420 parts of isophorone diisocyanate in 1500 parts of N-methylpyrrolidone, heating to 52-55° C., adding 1200-1250 parts of polypropylene glycol, and reacting at 52-55° C. for 3-5 hours to obtain an isocyanate-terminated first intermediate; Step 2: dissolving 400-420 parts of diaminodiphenylmethane in 900 parts of N-methylpyrrolidone, heating to 52-55° C., adding 180-200 parts of toluene diisocyanate, and reacting at 52-55° C. for 3-5 hours to obtain an amino-terminated second intermediate; Step 3: Add 1450-1480 parts of the first intermediate to 750-770 parts of the second intermediate, mix well, and react at 80-84° C. for 3-4 hours to obtain a polymer; (2) performing a first mixing of the epoxy resin, the polymer and the modified filler to obtain a first mixture; (3) adding an antioxidant, a defoaming agent, a dispersant, and a leveling agent to the first mixture in sequence, and performing a second mixing to obtain a second mixture; (4) mixing the second mixture with a polythiol curing agent to obtain a waterproof and wear-resistant epoxy coating for leather; The preparation method of the modified filler is: (1) calcining the mixed filler at a temperature of 800-900° C. for 40-60 minutes to obtain a calcined mixed filler; the mixed filler is a mixture of nano samarium oxide, boron nitride and organic bentonite in a mass ratio of 1:0.2-0.6:1.2-1.5; (2) crushing the calcined mixed filler and grinding it into 80-100 mesh mixed filler powder; (3) Mixing a mixed filler powder, tetramethylammonium bromide and ethanol aqueous solution in a mass ratio of 10:1-1.2:80-100, stirring evenly, heating at a temperature of 55-60° C. for 3-5 hours, filtering, and drying to obtain a modified mixed filler; The mass percentage concentration of the ethanol aqueous solution is 65-70%.

2. The preparation process of the waterproof and wear-resistant leather epoxy coating according to claim 1, characterized in that: The antioxidant is selected from at least one of antioxidant 1010, antioxidant 168, antioxidant BHT, and antioxidant 330.

3. The preparation process of the waterproof and wear-resistant leather epoxy coating according to claim 1, characterized in that: The defoaming agent is selected from at least one of TEGO901W defoaming agent, TEGO902W defoaming agent and TEGO801W defoaming agent.

4. The preparation process of the waterproof and wear-resistant leather epoxy coating according to claim 1, characterized in that: The dispersant is selected from at least one of TEGODispers715w, TEGODispers755w, and TEGOWet280.

5. The preparation process of the waterproof and wear-resistant leather epoxy coating according to claim 1, characterized in that: The leveling agent is selected from at least one of BYK300, BYK306 and BYK333.

6. An epoxy coating obtained by the preparation process according to any one of claims 1 to 5.

7. Use of the epoxy coating according to claim 6 in the preparation of leather products.

8. The use according to claim 7, characterized in that: The epoxy coating is applied to the preparation of leather shoes.

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