Wear-resistant and scratch-resistant leather and preparation method thereof

Abstract

The invention discloses wear-resistant and scratch-resistant leather and a preparation method thereof, and belongs to the technical field of leather preparation. The animal leather obtained after liming, softening, tanning and retanning is coated; the preparation method of the coating agent for coating comprises the following steps: preparing a polyurethane preform by taking polytetrahydrofuran, fluorine-containing dihydric alcohol and isophorone diisocyanate as raw materials; preparing a polyurethane emulsion by taking the polyurethane preform, a chain extender, coumarin and a derivative end-capping reagent thereof as raw materials; hydrotalcite modified silicon dioxide is prepared through a coprecipitation method, and then fluoridation modification is carried out; carrying out ultrasonic blending with dopamine hydrochloride, deionized water and ethanol, adding a Tris-HCl buffer solution, stirring, carrying out centrifugal separation, taking a solid phase, washing, and drying to obtain a polydopamine coating; the polyurethane emulsion and the polydopamine coating are taken and mixed, and the coating agent is obtained. The coating agent is coated on the surface of the leather, so that the wear resistance and scratch resistance of the leather are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of leather preparation, and particularly relates to wear-resistant and scratch-resistant leather and a preparation method thereof. Background Art

[0002] Leather, as a traditional fabric, is widely used in making various leather bags. Since leather bags are often seen as a store of value, consumers consider their long-term use potential when purchasing, so the durability of leather bags has become a growing focus. During daily use, the leather fabric of leather bags inevitably comes into frequent contact with the external environment, thus being affected by friction and scratches. In particular, the protruding edges of the seams are prone to damage due to frequent friction and scratches, leading to quality problems such as cracking and coating loss. Therefore, friction and scratches have become two important indicators for measuring leather quality. In view of this, the development of leather that is both wear-resistant and scratch-resistant not only has significant economic value, but also has far-reaching social value, as it can meet consumer demand for high-quality leather products.

[0003] The leather production process is a complex and delicate process that usually includes several key steps. First, the leather needs to be limed to remove hair and sebum, followed by a softening process to make the leather softer and more elastic. The leather then undergoes a tanning process, which is key to transforming it into a durable material. After tanning, retanning and filling are usually carried out to further enhance the structure and texture of the leather. Finally, the finishing process is an indispensable part of leather production. It applies a finishing agent to the leather surface to form a protective layer with adhesive strength and mechanical strength, thereby improving the appearance and durability of the leather and correcting grain defects on the leather surface.

[0004] In the leather finishing process, the use of finishing agents is crucial. Finishing agents are usually applied evenly to the leather surface through various methods such as wiping, brushing, and spraying to ensure the uniformity and quality of the coating. These finishing agents not only give the leather surface an aesthetically pleasing appearance, but more importantly, they can significantly improve the durability of the leather while also effectively concealing and correcting grain defects on the leather surface. There are many types of leather finishing agents, mainly including polyacrylic resins, polyurethane resins, nitrocellulose, and protein-based finishing agents. Although polyurethane materials have many excellent properties, they are inevitably subject to wear, scratches, and other damage during long-term use, affecting the appearance and service life of the leather. Summary of the Invention

[0005] The object of the present invention is to provide a wear-resistant and scratch-resistant leather and a preparation method thereof, so as to solve the problem that the wear-resistant and scratch-resistant performance of the leather surface coated with a polyurethane finishing agent is poor.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for preparing wear-resistant and scratch-resistant leather comprises applying a finishing treatment to animal leather that has been limed, softened, tanned, and retanned;

[0008] The finishing treatment is performed by roller coating the finishing agent on the leather surface and drying it to obtain the wear-resistant and scratch-resistant leather;

[0009] The preparation method of the finishing agent comprises the following steps:

[0010] S1. Mix N,N-dimethylformamide, polytetrahydrofuran, and fluorinated diol, add isophorone diisocyanate and dibutyltin dilaurate in a nitrogen atmosphere, and stir at 80° C. for 2-4 hours to obtain a polyurethane preform;

[0011] S2. Taking the polyurethane preform under heating conditions of 40-45° C., adding a chain extender and stirring for 2-3 hours, then adding a capping agent such as coumarin and its derivatives and continuing to stir for 1-2 hours to obtain a polyurethane emulsion;

[0012] S3, preparing hydrotalcite-modified silica by coprecipitation, calcining, immersing the obtained composite oxide in a fluoride ion solution and stirring at room temperature for 20-30 hours, filtering, washing the solid phase, drying, and calcining to obtain a fluorinated material;

[0013] S4, taking the fluorinated material, dopamine hydrochloride, deionized water, and ethanol, ultrasonically blending for 30-40 minutes, adding Tris-HCl buffer, stirring for 10-15 hours, centrifuging, washing the solid phase, and drying to obtain a polydopamine-coated material;

[0014] S5. Mix the polyurethane emulsion and the polydopamine coating, and stir at 40° C. for 20-30 minutes to obtain the finishing agent.

[0015] As a preferred technical solution of the present invention, in step S1, the mass ratio of N,N-dimethylformamide, polytetrahydrofuran, fluorinated diol, isophorone diisocyanate, and dibutyltin dilaurate is 5.1-5.7:6-7:1-2:4.2-4.6:0.02.

[0016] As a preferred technical solution of the present invention, in step S2, the mass ratio of the polyurethane preform, the chain extender, and the end-capping agent is 13.5-16.2:1.1-1.3:1.8-2.0.

[0017] As a preferred technical solution of the present invention, in step S3, the first calcination refers to calcination in an air atmosphere at 400-450°C for 3-4 hours; the second calcination refers to calcination in an air atmosphere at 400-450°C for 5-7 hours.

[0018] As a preferred technical solution of the present invention, in step S4, the dosage ratio of the fluorinated material, dopamine hydrochloride, deionized water, ethanol, and Tris-HCl buffer is 180-220 mg: 150-190 mg: 250 mL: 20-30 mL: 165-205 mL.

[0019] As a preferred technical solution of the present invention, in step S5, the mass ratio of the polyurethane emulsion to polydopamine is 16.4-19.5:2.4-3.1.

[0020] As a preferred technical solution of the present invention, the animal leather is any one of sheepskin, first-layer cowhide or second-layer cowhide.

[0021] As a preferred technical solution of the present invention, the fluoride ion solution is any one of a sodium fluoride aqueous solution or a potassium fluoride aqueous solution.

[0022] As a preferred technical solution of the present invention, the fluorine-containing diol includes at least one of tetrafluorobutanediol, 2,2,3,3,4,4-hexafluorocyclo-1,5-pentanediol, hexafluoropentanediol, 1H,1H,8H,8H-dodecafluoro-1,8-octanediol, octafluorohexanediol, dodecafluorooctanediol, and perfluorodecanediol.

[0023] The wear-resistant and scratch-resistant leather is prepared by the above-mentioned preparation method.

[0024] Beneficial effects of the present invention:

[0025] The present invention discloses a wear-resistant and scratch-resistant leather and a preparation method thereof. By preparing fluorinated polyurethane and optimizing the formulation composition, a finishing agent with excellent self-repairing properties is obtained. By introducing cyclocoumarin and its derivatives, when the leather surface is scratched, the physical cross-linked network synergistically generated by coumarin and multiple hydrogen bonds is utilized to promote the self-repair of scratches on the leather surface, thereby improving the leather's scratch resistance.

[0026] Furthermore, polydopamine-coated mesoporous nano-silica was introduced as a photothermal conversion agent for fluorinated polyurethane self-repair, and it can also be used as a reinforcing filler to improve the wear resistance of leather.

[0027] In addition, in order to improve the dispersion performance of the polydopamine coating in the emulsion and prevent agglomeration, hydrotalcite is in situ grown on the surface of the mesoporous silica. With the help of its high specific surface area and pore structure, it provides evenly dispersed anchoring points for the hydrotalcite, enhances its mechanical stability, and improves its wear resistance. Furthermore, the adsorption effect of hydrotalcite on fluoride ions is utilized. The surface of the hydrotalcite after adsorption is rich in fluorine groups, which improves the compatibility of the material with fluorine-containing polyurethane, improves the dispersion effect of the polydopamine coating, avoids the reduction of wear resistance caused by agglomeration, and thus improves the wear resistance of the leather. DETAILED DESCRIPTION

[0028] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0029] Preparation Example 1

[0030] The preparation method of the coating agent for finishing comprises the following steps:

[0031] S1. Mix N,N-dimethylformamide, polytetrahydrofuran, 1H,1H,8H,8H-dodecafluoro-1,8-octanediol and octafluorohexanediol, add isophorone diisocyanate and dibutyltin dilaurate in a nitrogen atmosphere, and stir at 80° C. for 2 h to obtain a polyurethane preform; the mass ratio of N,N-dimethylformamide, polytetrahydrofuran, fluorinated diol, isophorone diisocyanate and dibutyltin dilaurate is 5.1:6:1:4.2:0.02;

[0032] S2. Adding a chain extender, L-cystine, to the polyurethane preform under heating at 40° C. and stirring for 2 h, then adding a capping agent, 7-hydroxy-4-methylcoumarin, and continuing to stir for 1 h to obtain a polyurethane emulsion; wherein the mass ratio of the polyurethane preform, chain extender, and capping agent is 13.5:1.1:1.8;

[0033] S3, 0.03 mol of magnesium nitrate hexahydrate, 0.01 mol of aluminum nitrate nonahydrate, and 100 mL of deionized water were mixed, stirred for 4 min, 0.05 mol of sodium hydroxide and 0.02 mol of anhydrous sodium carbonate were added, and the mixture was heated and stirred in a water bath at 55° C. for 20 h to obtain a mixture;

[0034] 3 g of nano-silica and 50 mL of deionized water were mixed and ultrasonically dispersed for 20 minutes, the mixture was added, stirred for 10 hours, filtered, and the solid phase was calcined at 400° C. in air for 3 hours. The obtained composite oxide was immersed in 20 mL of a 20% potassium fluoride aqueous solution, stirred at room temperature for 20 hours, filtered, and the solid phase was washed, dried, and then calcined at 400° C. in air for 5 hours to obtain a fluorinated material;

[0035] S4. The fluorinated material, dopamine hydrochloride, deionized water, and ethanol were ultrasonically blended for 30 min, Tris-HCl buffer (10 mM, pH = 8.5) was added, stirred for 10 h, centrifuged, the solid phase was washed, and dried to obtain a polydopamine-coated material; the ratio of the fluorinated material, dopamine hydrochloride, deionized water, ethanol, and Tris-HCl buffer was 180 mg: 150 mg: 250 mL: 20 mL: 165 mL;

[0036] S5. Mix the polyurethane emulsion and the polydopamine coating, and stir at 40° C. for 20 minutes to obtain the finishing agent; the mass ratio of the polyurethane emulsion to polydopamine is 16.4:2.4.

[0037] Preparation Example 2

[0038] The preparation method of the coating agent for finishing comprises the following steps:

[0039] S1. Mix N,N-dimethylformamide, polytetrahydrofuran, 1H,1H,8H,8H-dodecafluoro-1,8-octanediol and octafluorohexanediol, add isophorone diisocyanate and dibutyltin dilaurate in a nitrogen atmosphere, and stir at 80° C. for 2.5 hours to obtain a polyurethane preform; the mass ratio of N,N-dimethylformamide, polytetrahydrofuran, fluorinated diol, isophorone diisocyanate and dibutyltin dilaurate is 5.25:6.2:1.2:4.3:0.02;

[0040] S2. Adding a chain extender, L-cystine, to the polyurethane preform under heating at 42° C. and stirring for 2.2 hours, then adding a capping agent, 7-hydroxy-4-methylcoumarin, and continuing to stir for 1.2 hours to obtain a polyurethane emulsion; wherein the mass ratio of the polyurethane preform, chain extender, and capping agent is 13.9:1.15:1.85;

[0041] S3, 0.03 mol of magnesium nitrate hexahydrate, 0.01 mol of aluminum nitrate nonahydrate, and 100 mL of deionized water were mixed and stirred for 5 min, 0.05 mol of sodium hydroxide and 0.02 mol of anhydrous sodium carbonate were added, and the mixture was heated and stirred in a water bath at 60° C. for 20 h to obtain a mixture;

[0042] 3.2 g of nano-silica and 50 mL of deionized water were mixed and ultrasonically dispersed for 25 min, the mixture was added, stirred for 15 h, filtered, and the solid phase was calcined at 420 ° C in air for 3.5 h. The obtained composite oxide was immersed in 20 mL of a 23% potassium fluoride aqueous solution, stirred at room temperature for 25 h, filtered, and the solid phase was washed and dried, and then calcined at 420 ° C in air for 6 h to obtain a fluorinated material;

[0043] S4. The fluorinated material, dopamine hydrochloride, deionized water, and ethanol were ultrasonically blended for 35 minutes, Tris-HCl buffer (10 mM, pH = 8.5) was added, stirred for 12 hours, centrifuged, the solid phase was washed, and dried to obtain a polydopamine-coated material; the ratio of the fluorinated material, dopamine hydrochloride, deionized water, ethanol, and Tris-HCl buffer was 190 mg: 160 mg: 250 mL: 25 mL: 175 mL;

[0044] S5. Mix the polyurethane emulsion and the polydopamine coating, and stir at 40° C. for 25 minutes to obtain the finishing agent; the mass ratio of the polyurethane emulsion to polydopamine is 16.9:2.6.

[0045] Preparation Example 3

[0046] The preparation method of the coating agent for finishing comprises the following steps:

[0047] S1. Mix N,N-dimethylformamide, polytetrahydrofuran, 1H,1H,8H,8H-dodecafluoro-1,8-octanediol and octafluorohexanediol, add isophorone diisocyanate and dibutyltin dilaurate in a nitrogen atmosphere, and stir at 80° C. for 3 h to obtain a polyurethane preform; the mass ratio of N,N-dimethylformamide, polytetrahydrofuran, fluorinated diol, isophorone diisocyanate and dibutyltin dilaurate is 5.4:6.5:1.5:4.4:0.02;

[0048] S2. Adding a chain extender, L-cystine, to the polyurethane preform under heating at 43° C. and stirring for 2.5 hours, then adding a capping agent, 7-hydroxy-4-methylcoumarin, and continuing to stir for 1.5 hours to obtain a polyurethane emulsion; wherein the mass ratio of the polyurethane preform, chain extender, and capping agent is 15.3:1.2:1.9;

[0049] S3, 0.03 mol of magnesium nitrate hexahydrate, 0.01 mol of aluminum nitrate nonahydrate, and 100 mL of deionized water were mixed and stirred for 5 min, 0.05 mol of sodium hydroxide and 0.02 mol of anhydrous sodium carbonate were added, and the mixture was heated and stirred in a water bath at 60° C. for 20 h to obtain a mixture;

[0050] 3.5 g of nano-silica and 50 mL of deionized water were mixed and ultrasonically dispersed for 25 minutes, the mixture was added, stirred for 15 hours, filtered, and the solid phase was calcined at 425° C. in an air atmosphere for 3.5 hours. The obtained composite oxide was immersed in 20 mL of a 28% potassium fluoride aqueous solution, stirred at room temperature for 25 hours, filtered, and the solid phase was washed, dried, and then calcined at 425° C. in an air atmosphere for 6 hours to obtain a fluorinated material;

[0051] S4. The fluorinated material, dopamine hydrochloride, deionized water, and ethanol were ultrasonically blended for 35 minutes, Tris-HCl buffer (10 mM, pH = 8.5) was added, stirred for 13 hours, centrifuged, the solid phase was washed, and dried to obtain a polydopamine-coated material; the ratio of the fluorinated material, dopamine hydrochloride, deionized water, ethanol, and Tris-HCl buffer was 200 mg: 170 mg: 250 mL: 25 mL: 185 mL;

[0052] S5. Mix the polyurethane emulsion and the polydopamine coating, and stir at 40° C. for 25 minutes to obtain the coating agent; the mass ratio of the polyurethane emulsion to polydopamine is 18:2.8.

[0053] Preparation Example 4

[0054] The preparation method of the coating agent for finishing comprises the following steps:

[0055] S1. Mix N,N-dimethylformamide, polytetrahydrofuran, 1H,1H,8H,8H-dodecafluoro-1,8-octanediol and octafluorohexanediol, add isophorone diisocyanate and dibutyltin dilaurate in a nitrogen atmosphere, and stir at 80° C. for 3 h to obtain a polyurethane preform; the mass ratio of N,N-dimethylformamide, polytetrahydrofuran, fluorinated diol, isophorone diisocyanate, and dibutyltin dilaurate is 5.6:6.8:1.8:4.5:0.02;

[0056] S2. Adding a chain extender, L-cystine, to the polyurethane preform under heating at 44° C. and stirring for 2.5 hours, then adding a capping agent, 7-hydroxy-4-methylcoumarin, and continuing to stir for 1.8 hours to obtain a polyurethane emulsion; wherein the mass ratio of the polyurethane preform, chain extender, and capping agent is 15.8:1.25:1.95;

[0057] S3, 0.03 mol of magnesium nitrate hexahydrate, 0.01 mol of aluminum nitrate nonahydrate, and 100 mL of deionized water were mixed and stirred for 5 min, 0.05 mol of sodium hydroxide and 0.02 mol of anhydrous sodium carbonate were added, and the mixture was heated and stirred in a water bath at 62° C. for 20 h to obtain a mixture;

[0058] 3.8 g of nano-silica and 50 mL of deionized water were mixed and ultrasonically dispersed for 28 minutes, the mixture was added, stirred for 18 hours, filtered, and the solid phase was calcined at 440° C. in an air atmosphere for 3.5 hours. The obtained composite oxide was immersed in 20 mL of a 32% potassium fluoride aqueous solution, stirred at room temperature for 28 hours, filtered, and the solid phase was washed, dried, and then calcined at 440° C. in an air atmosphere for 6 hours to obtain a fluorinated material;

[0059] S4. The fluorinated material, dopamine hydrochloride, deionized water, and ethanol were ultrasonically blended for 38 minutes, Tris-HCl buffer (10 mM, pH = 8.5) was added, stirred for 14 hours, centrifuged, the solid phase was washed, and dried to obtain a polydopamine-coated material; the ratio of the fluorinated material, dopamine hydrochloride, deionized water, ethanol, and Tris-HCl buffer was 210 mg: 180 mg: 250 mL: 28 mL: 198 mL;

[0060] S5. Mix the polyurethane emulsion and the polydopamine coating, and stir at 40° C. for 28 minutes to obtain the coating agent; the mass ratio of the polyurethane emulsion to polydopamine is 19:2.9.

[0061] Preparation Example 5

[0062] The preparation method of the coating agent for finishing comprises the following steps:

[0063] S1. Mix N,N-dimethylformamide, polytetrahydrofuran, 1H,1H,8H,8H-dodecafluoro-1,8-octanediol and octafluorohexanediol, add isophorone diisocyanate and dibutyltin dilaurate in a nitrogen atmosphere, and stir at 80° C. for 4 hours to obtain a polyurethane preform; the mass ratio of N,N-dimethylformamide, polytetrahydrofuran, fluorinated diol, isophorone diisocyanate and dibutyltin dilaurate is 5.7:7:2:4.6:0.02;

[0064] S2. Adding a chain extender, L-cystine, to the polyurethane preform under heating at 45° C. and stirring for 3 h, then adding a capping agent, 7-hydroxy-4-methylcoumarin, and continuing to stir for 2 h to obtain a polyurethane emulsion; wherein the mass ratio of the polyurethane preform, chain extender, and capping agent is 16.2:1.3:2.0;

[0065] S3, take 0.03 mol of magnesium nitrate hexahydrate, 0.01 mol of aluminum nitrate nonahydrate, and 100 mL of deionized water, mix them, stir for 6 min, add 0.05 mol of sodium hydroxide and 0.02 mol of anhydrous sodium carbonate, heat and stir in a water bath at 65° C. for 20 h to obtain a mixture;

[0066] 4 g of nano-silica and 50 mL of deionized water were mixed and ultrasonically dispersed for 30 minutes, the mixture was added, stirred for 20 hours, filtered, and the solid phase was calcined at 450° C. in air for 4 hours. The obtained composite oxide was immersed in 20 mL of a 35% potassium fluoride aqueous solution, stirred at room temperature for 30 hours, filtered, and the solid phase was washed and dried, and then calcined at 450° C. in air for 7 hours to obtain a fluorinated material;

[0067] S4. The fluorinated material, dopamine hydrochloride, deionized water, and ethanol were ultrasonically blended for 40 min, Tris-HCl buffer (10 mM, pH = 8.5) was added, stirred for 15 h, centrifuged, the solid phase was washed, and dried to obtain a polydopamine-coated material; the ratio of the fluorinated material, dopamine hydrochloride, deionized water, ethanol, and Tris-HCl buffer was 220 mg: 190 mg: 250 mL: 30 mL: 205 mL;

[0068] S5. Mix the polyurethane emulsion and the polydopamine coating, and stir at 40° C. for 30 minutes to obtain the coating agent; the mass ratio of the polyurethane emulsion to polydopamine is 19.5:3.1.

[0069] Preparation Example 6

[0070] The difference from Preparation Example 3 is that 1-nonanol is used as the end-capping agent in the preparation of the coating agent.

[0071] Preparation Example 7

[0072] The difference from Preparation Example 3 is that the composite oxide prepared in step S3 during the preparation of the coating agent for coating is not immersed in a fluoride ion solution.

[0073] Preparation Example 8

[0074] The difference from Preparation Example 3 is that the preparation of step S3 in the preparation process of the finishing agent is as follows:

[0075] S3. Take 3.5 g of nano-silica and 50 mL of deionized water, mix and ultrasonically disperse for 25 minutes, add the mixed material, stir for 15 hours, filter, take the solid phase and calcine in an air atmosphere at 425°C for 3.5 hours, and immerse the obtained calcined silica in 20 mL of a 28% potassium fluoride aqueous solution, stir at room temperature for 25 hours, filter, take the solid phase, wash, dry, and then calcine in an air atmosphere at 425°C for 6 hours to obtain a fluorinated material.

[0076] Preparation Example 9

[0077] The difference from Preparation Example 3 is that the preparation process of the finishing agent is as follows:

[0078] S1. Mix N,N-dimethylformamide, polytetrahydrofuran, 1H,1H,8H,8H-dodecafluoro-1,8-octanediol and octafluorohexanediol, add isophorone diisocyanate and dibutyltin dilaurate in a nitrogen atmosphere, and stir at 80° C. for 3 h to obtain a polyurethane preform; the mass ratio of N,N-dimethylformamide, polytetrahydrofuran, fluorinated diol, isophorone diisocyanate and dibutyltin dilaurate is 5.4:6.5:1.5:4.4:0.02;

[0079] S2. Under heating conditions at 43° C., take the polyurethane preform, add the chain extender L-cystine, and stir for 2.5 hours. Then, add the end-capping agent 7-hydroxy-4-methylcoumarin and continue stirring for 1.5 hours to obtain a polyurethane emulsion, which is the finishing agent; the mass ratio of the polyurethane preform, chain extender, and end-capping agent is 15.3:1.2:1.9.

[0080] Example 1

[0081] A method for preparing wear-resistant and scratch-resistant leather comprises applying a finishing treatment to animal leather that has been limed, softened, tanned, and retanned;

[0082] The animal leather is selected from sheepskin;

[0083] The finishing treatment was carried out by roller coating the finishing agent prepared in Preparation Example 1 on the leather surface, with a roller coating amount of 20 g / m 2 , and cured at 45° C. for 24 hours to obtain the wear-resistant and scratch-resistant leather.

[0084] Example 2

[0085] A method for preparing wear-resistant and scratch-resistant leather comprises applying a finishing treatment to animal leather that has been limed, softened, tanned, and retanned;

[0086] The animal leather is selected from sheepskin;

[0087] The finishing treatment was carried out by roller coating the finishing agent prepared in Preparation Example 2 on the leather surface, with a roller coating amount of 20 g / m 2 , and cured at 45° C. for 24 hours to obtain the wear-resistant and scratch-resistant leather.

[0088] Example 3

[0089] A method for preparing wear-resistant and scratch-resistant leather comprises applying a finishing treatment to animal leather that has been limed, softened, tanned, and retanned;

[0090] The animal leather is selected from sheepskin;

[0091] The finishing treatment was carried out by roller coating the finishing agent prepared in Preparation Example 3 on the leather surface, with a roller coating amount of 20 g / m 2 , and cured at 45° C. for 24 hours to obtain the wear-resistant and scratch-resistant leather.

[0092] Example 4

[0093] A method for preparing wear-resistant and scratch-resistant leather comprises applying a finishing treatment to animal leather that has been limed, softened, tanned, and retanned;

[0094] The animal leather is selected from sheepskin;

[0095] The finishing treatment was carried out by roller coating the finishing agent prepared in Preparation Example 4 on the leather surface, with a roller coating amount of 20 g / m 2 , and cured at 45° C. for 24 hours to obtain the wear-resistant and scratch-resistant leather.

[0096] Example 5

[0097] A method for preparing wear-resistant and scratch-resistant leather comprises applying a finishing treatment to animal leather that has been limed, softened, tanned, and retanned;

[0098] The animal leather is selected from sheepskin;

[0099] The finishing treatment was carried out by roller coating the finishing agent prepared in Preparation Example 5 on the leather surface, with a roller coating amount of 20 g / m 2 , and cured at 45° C. for 24 hours to obtain the wear-resistant and scratch-resistant leather.

[0100] Comparative Example 1

[0101] A method for preparing wear-resistant and scratch-resistant leather comprises applying a finishing treatment to animal leather that has been limed, softened, tanned, and retanned;

[0102] The animal leather is selected from sheepskin;

[0103] The finishing treatment was carried out by roller coating the finishing agent prepared in Preparation Example 6 on the leather surface, with a roller coating amount of 20 g / m 2 , and cured at 45° C. for 24 hours to obtain the wear-resistant and scratch-resistant leather.

[0104] Comparative Example 2

[0105] A method for preparing wear-resistant and scratch-resistant leather comprises applying a finishing treatment to animal leather that has been limed, softened, tanned, and retanned;

[0106] The animal leather is selected from sheepskin;

[0107] The finishing treatment was carried out by roller coating the finishing agent prepared in Preparation Example 7 on the leather surface, with a roller coating amount of 20 g / m 2 , and cured at 45° C. for 24 hours to obtain the wear-resistant and scratch-resistant leather.

[0108] Comparative Example 3

[0109] A method for preparing wear-resistant and scratch-resistant leather comprises applying a finishing treatment to animal leather that has been limed, softened, tanned, and retanned;

[0110] The animal leather is selected from sheepskin;

[0111] The finishing treatment was carried out by roller coating the finishing agent prepared in Preparation Example 8 on the leather surface, with a roller coating amount of 20 g / m 2 , and cured at 45° C. for 24 hours to obtain the wear-resistant and scratch-resistant leather.

[0112] Comparative Example 4

[0113] A method for preparing wear-resistant and scratch-resistant leather comprises applying a finishing treatment to animal leather that has been limed, softened, tanned, and retanned;

[0114] The animal leather is selected from sheepskin;

[0115] The finishing treatment was carried out by roller coating the finishing agent prepared in Preparation Example 9 on the leather surface, with a roller coating amount of 20 g / m 2 , and cured at 45° C. for 24 hours to obtain the wear-resistant and scratch-resistant leather.

[0116] Performance Testing

[0117] Test Example 1

[0118] The leathers prepared in Examples 1-5 and Comparative Examples 1-4 were tested for wear resistance according to standard GB / T39507-2020. The test results are shown in Table 1.

[0119] Table 1

[0120] Friction times (times) Example 1 2100 Example 2 2100 Example 3 2300 Example 4 2200 Example 5 2100 Comparative Example 1 1900 Comparative Example 2 1700 Comparative Example 3 1400 Comparative Example 4 1000

[0121] As can be seen from Table 1, the leathers prepared in Examples 1-5 of the present application have good wear resistance; in Comparative Example 1, no capping agent containing a polycyclic structure was added, resulting in a decrease in wear resistance; in Comparative Example 2, no fluorine treatment was performed, resulting in poor dispersion of the polydopamine coating in the emulsion and severe agglomeration, resulting in reduced wear resistance; in Comparative Example 3, no hydrotalcite structure was generated, resulting in reduced wear resistance; in Comparative Example 4, no polydopamine coating was added, resulting in a significant decrease in wear resistance.

[0122] Test Example 2

[0123] The leathers prepared in Examples 1-5 and Comparative Example 1 were tested for self-repairing properties. The test results are shown in Table 2.

[0124] The self-repair performance of leather is evaluated by observing the width of the scratch and calculating its self-repair efficiency:

[0125]

[0126] Table 2

[0127]

[0128] As can be seen from Table 2, the leathers prepared in Examples 1-5 of the present application have excellent self-repairing properties, so that when they are scratched, they can self-repair, thereby improving the scratch resistance; in Comparative Example 1, conventional monohydric alcohol is selected for end-capping. Although it exhibits certain self-repairing properties, it is far inferior to the self-repairing healing properties of coumarin and its derivatives.

[0129] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing wear-resistant and scratch-resistant leather, characterized in that: The animal leather after liming, softening, tanning and retanning is subjected to a finishing treatment; the finishing treatment comprises rolling a finishing agent onto the leather surface and drying, thereby obtaining the wear-resistant and scratch-resistant leather; The preparation method of the finishing agent comprises the following steps: S1. A polyurethane preform is prepared using polytetrahydrofuran, fluorinated diol, and isophorone diisocyanate as raw materials and N,N-dimethylformamide and dibutyltin dilaurate as auxiliary agents; S2. preparing a polyurethane emulsion using the polyurethane preform, chain extender, coumarin and its derivative end-capping agent as raw materials; S3. Prepare hydrotalcite-modified silica by coprecipitation, calcine, immerse in a fluoride ion solution, filter, take the solid phase, wash, dry, and calcine to obtain a fluorinated material; S4, taking the fluorinated material, dopamine hydrochloride, deionized water, and ethanol, ultrasonically blending, adding Tris-HCl buffer, stirring, centrifuging, washing, and drying the solid phase to obtain a polydopamine-coated material; S5. Mix the polyurethane emulsion and the polydopamine coating to obtain the finishing agent.

2. The method for preparing wear-resistant and scratch-resistant leather according to claim 1, characterized in that: In step S1, the mass ratio of the N,N-dimethylformamide, polytetrahydrofuran, fluorinated diol, isophorone diisocyanate, and dibutyltin dilaurate is 5.1-5.7:6-7:1-2:4.2-4.6:0.

02.

3. The method for preparing wear-resistant and scratch-resistant leather according to claim 1, characterized in that: In step S2, the mass ratio of the polyurethane preform, the chain extender, and the coumarin and its derivative end-capping agent is 13.5-16.2:1.1-1.3:1.8-2.

0.

4. The method for preparing wear-resistant and scratch-resistant leather according to claim 1, characterized in that: In step S3, the first calcination refers to calcination in an air atmosphere at 400-450°C for 3-4 hours; the second calcination refers to calcination in an air atmosphere at 400-450°C for 5-7 hours.

5. The method for preparing wear-resistant and scratch-resistant leather according to claim 1, characterized in that: In step S4, the ratio of the fluorinated material, dopamine hydrochloride, deionized water, ethanol, and Tris-HCl buffer is 180-220 mg: 150-190 mg: 250 mL: 20-30 mL: 165-205 mL.

6. The method for preparing wear-resistant and scratch-resistant leather according to claim 1, characterized in that: In step S5, the mass ratio of the polyurethane emulsion to polydopamine is 16.4-19.5:2.4-3.

1.

7. The method for preparing wear-resistant and scratch-resistant leather according to claim 1, characterized in that: The animal leather is any one of sheepskin, first-layer cowhide or second-layer cowhide.

8. The method for preparing wear-resistant and scratch-resistant leather according to claim 1, characterized in that: The fluoride ion solution is any one of a sodium fluoride aqueous solution or a potassium fluoride aqueous solution.

9. The method for preparing wear-resistant and scratch-resistant leather according to claim 1, characterized in that: The fluorine-containing diol includes at least one of tetrafluorobutanediol, 2,2,3,3,4,4-hexafluorocyclo-1,5-pentanediol, hexafluoropentanediol, 1H,1H,8H,8H-dodecafluoro-1,8-octanediol, octafluorohexanediol, dodecafluorooctanediol, and perfluorodecanediol.

10. A wear-resistant and scratch-resistant leather produced by the method according to any one of claims 1 to 9.

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