Wear-resistant and scratch-resistant leather and method for producing same

Abstract

The application discloses wear-resistant and scratch-resistant leather and a preparation method thereof and belongs to the technical field of leather preparation. After animal leather is limed, softened, tanned and retanned, the animal leather is coated; a preparation method of a coating agent for coating is as follows: a polyurethane preform is prepared by taking polytetrahydrofuran, fluorine-containing dihydric alcohol and isophorone diisocyanate as raw materials; a polyurethane emulsion is prepared by taking the polyurethane preform, a chain extender, coumarin and a derivative thereof as raw materials; hydrotalcite modified silicon dioxide is prepared by a coprecipitation method, and then is fluorinated; the polydopamine coating is obtained by ultrasonic blending of dopamine hydrochloride, deionized water and ethanol, adding Tris-HCl buffer solution, stirring, centrifugal separation, washing of the solid phase and drying; the coating agent is obtained by mixing the polyurethane emulsion and the polydopamine coating; and the wear-resistant and scratch-resistant performance of the leather is improved by roll coating the coating agent on the surface of the leather.

Description

TECHNICAL FIELD

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

[0002] Leather, as a traditional fabric, is widely used in the production of various leather bags. Since leather bags are often regarded as a kind of value-preserving product, consumers will consider the possibility of long-term use when purchasing, so the durability of leather bags has become the focus of people's attention. In the process of daily use, the leather fabric of the leather bag inevitably comes into frequent contact with the external environment, thus suffering the influence of friction and scratching. In particular, the part with the edge of the stitching line protruding is prone to damage due to frequent friction and scratching, resulting in quality problems such as cracking and coating peeling. Therefore, friction and scratching have become two important indicators for measuring the quality of leather. 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, because it can meet the needs of consumers for high-quality leather products.

[0003] The production process of leather is a complex and delicate process, which usually includes multiple key steps. First, the leather needs to be treated with liming to remove hair and sebum, and then softening treatment is performed to make the leather softer and more elastic. Subsequently, the leather will undergo tanning, which is a crucial step in transforming the leather into a durable material. After tanning, usually retanning and filling are performed to further enhance the structure and texture of the leather. Finally, the finishing process is an indispensable part of leather production, which forms a protective layer with adhesive strength and mechanical strength on the leather surface by applying a finishing agent, thereby improving the appearance, durability of the leather, and being able to correct the grain defects on the surface of the leather.

[0004] In the process of leather finishing, the use of finishing agents is crucial. Finishing agents are usually applied uniformly 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 effectively concealing and correcting the grain defects on the surface of the leather. There are various types of leather finishing agents, mainly including polyacrylic resin, polyurethane resin, nitrocellulose, and protein-based finishing agents, etc. Although polyurethane materials have many excellent properties, they are inevitably subject to wear and tear, scratches, and other damage during long-term use, affecting the appearance and service life of the leather. SUMMARY

[0005] The purpose of the present application is to provide a wear-resistant and scratch-resistant leather and a preparation method thereof, which solves the problem of poor wear-resistant and scratch-resistant performance of polyurethane finishing agent coated on the surface of leather.

[0006] The object of the present application can be achieved by the following technical solutions:

[0007] A preparation method of wear-resistant and scratch-resistant leather, which comprises the following steps:

[0008] The finishing treatment is performed by roll coating a finishing agent onto the surface of the leather, and then drying, to obtain the wear-resistant and scratch-resistant leather.

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

[0010] S1, mixing N,N-dimethylformamide, polytetrahydrofuran and fluorine-containing diol, and adding isophorone diisocyanate and dibutyltin dilaurate under a nitrogen atmosphere, stirring at 80℃ for 2-4h, to obtain a polyurethane preform;

[0011] S2, under heating at 40-45℃, adding a chain extender to the polyurethane preform and stirring for 2-3h, and then adding coumarin and its derivative end-capping agent and continuing to stir for 1-2h, to obtain a polyurethane emulsion;

[0012] S3, preparing hydrotalcite modified silicon dioxide by co-precipitation, calcining, immersing the obtained composite oxide in a fluorine ion solution, stirring at room temperature for 20-30h, suction filtering, washing the solid phase, drying, and calcining, to obtain a fluorinated material;

[0013] S4, ultrasonic blending the fluorinated material, dopamine hydrochloride, deionized water and ethanol for 30-40min, adding Tris-HCl buffer solution, stirring for 10-15h, centrifugal separation, washing the solid phase, and drying, to obtain a polydopamine coating;

[0014] S5, mixing the polyurethane emulsion and the polydopamine coating, and stirring at 40℃ for 20-30min, to obtain the finishing agent.

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

[0016] In a preferred technical solution of the present application, 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 application, in step S3, the first calcination refers to calcination in an air atmosphere at 400-450 DEG C for 3-4h; the second calcination refers to calcination in an air atmosphere at 400-450 DEG C for 5-7h.

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

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

[0020] As a preferred technical solution of the present application, the animal leather is any one of sheepskin, head layer cowhide or two layer cowhide.

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

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

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

[0024] The present application has the following beneficial effects:

[0025] The abrasion-resistant and scratch-resistant leather and the preparation method thereof disclosed by the present application, by preparing fluorine-containing polyurethane, optimizing the formula composition, obtaining a finishing agent with good self-repairing performance, by introducing ring coumarin and its derivatives, when the surface of the leather is scratched, the physical crosslinking network generated by the cooperation of coumarin and multiple hydrogen bonds promotes the self-repairing of the scratches on the surface of the leather, and the abrasion resistance of the leather is improved.

[0026] Further, the polydopamine-coated mesoporous nanosilica is introduced as a light-heat conversion agent for fluorine-containing polyurethane self-repairing, and can be used as a reinforcing filler to improve the abrasion resistance of the leather.

[0027] In addition, in order to improve the dispersion performance of the polydopamine coating in the emulsion, prevent agglomeration, grow hydrotalcite on the surface of the mesoporous silica in situ, provide uniform dispersion anchoring sites for the hydrotalcite by means of the high specific surface area and pore structure, enhance the mechanical stability, and improve the wear resistance; further, by using the adsorption effect of the hydrotalcite on fluorine ions, the surface of the adsorbed hydrotalcite is rich in fluorine groups, the compatibility of the material with fluorine-containing polyurethane is improved, the dispersion effect of the polydopamine coating is improved, the wear resistance caused by agglomeration is avoided, and thus the wear resistance of the leather is improved. DETAILED DESCRIPTION

[0028] In order to further illustrate the technical means and effects adopted by the present application to achieve the predetermined object, the specific embodiments, structures, features and effects according to the present application are described in detail as follows in combination with examples.

[0029] Preparation Example 1

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

[0031] S1, N,N-dimethylformamide, polytetrahydrofuran, 1H, 1H, 8H, 8H-dodecafluoro-1,8-octanediol octafluorohexanediol were mixed, isophorone diisocyanate, dibutyltin dilaurate were added in a nitrogen atmosphere, stirring at 80℃ for 2h, to obtain a polyurethane preform; the mass ratio of N,N-dimethylformamide, polytetrahydrofuran, fluorine-containing diol, isophorone diisocyanate, dibutyltin dilaurate is 5.1:6:1:4.2:0.02;

[0032] S2, under heating conditions at 40℃, the polyurethane preform was taken, a chain extender L-cystine was added and stirred for 2h, then a blocking agent 7-hydroxy-4-methyl coumarin was added and continued to stir for 1h, to obtain a polyurethane emulsion; the mass ratio of the polyurethane preform, the chain extender, and the blocking agent is 13.5:1.1:1.8;

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

[0034] 3g of nanosilica, 50mL of deionized water were mixed and ultrasonically dispersed for 20min, the mixture was added, stirred for 10h, and then filtered, the solid phase was calcined at 400℃ in an air atmosphere for 3h, the obtained composite oxide was immersed in 20mL of a 20% mass fraction potassium fluoride aqueous solution, stirred at room temperature for 20h, filtered, the solid phase was washed and dried, and then calcined at 400℃ in an air atmosphere for 5h, to obtain a fluorine-containing material;

[0035] S4, take the fluoride material, dopamine hydrochloride, deionized water, ethanol ultrasonic blending for 30 min, add Tris-HCl buffer (10 mM, pH=8.5), stir for 10 h, centrifugal separation, take the solid phase washing, drying, get polydopamine coated material; the fluoride material, dopamine hydrochloride, deionized water, ethanol, Tris-HCl buffer ratio is 180 mg: 150 mg: 250 mL: 20 mL: 165 mL;

[0036] S5, take the polyurethane emulsion, polydopamine coated material mixed, stirring at 40℃ for 20 min, the finishing agent is obtained; the mass ratio of polyurethane emulsion, polydopamine coated material is 16.4:2.4.

[0037] Preparation example 2

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

[0039] S1, take N,N-dimethylformamide, polytetrahydrofuran, 1H,1H,8H,8H-dodecafluoro-1,8-octanediol octafluorohexanediol mixed, in the nitrogen atmosphere, add isophorone diisocyanate, dibutyltin dilaurate, 80℃ stirring for 2.5h, get polyurethane preform; the mass ratio of N,N-dimethylformamide, polytetrahydrofuran, fluorine containing diol, isophorone diisocyanate, dibutyltin dilaurate is 5.25:6.2:1.2:4.3:0.02;

[0040] S2, under the condition of heating at 42℃, take the polyurethane preform, add chain extender L-cystine stirring for 2.2h, then add end capping agent 7-hydroxy-4-methyl coumarin continue stirring for 1.2h, get polyurethane emulsion; the mass ratio of polyurethane preform, chain extender, end capping agent is 13.9:1.15:1.85;

[0041] S3, take 0.03 mol of magnesium nitrate hexahydrate, 0.01 mol of aluminum nitrate nonahydrate, 100 mL of deionized water mixed, stirring for 5 min, add 0.05 mol of sodium hydroxide, 0.02 mol of anhydrous sodium carbonate, heating stirring for 20 h in 60℃ water bath, get mixed material;

[0042] Take 3.2 g of nano silicon dioxide, 50 mL of deionized water mixed ultrasonic dispersion for 25 min, add the mixed material, stirring for 15 h, suction filtration, take the solid phase to 420℃ air atmosphere calcination for 3.5h, the obtained composite oxide is immersed in 20 mL, mass fraction of 23% potassium fluoride aqueous solution, stirring for 25 h at room temperature, suction filtration, take the solid phase washing, drying, then calcination for 6 h in 420℃ air atmosphere, get fluoride material;

[0043] S4, the fluoride material, dopamine hydrochloride, deionized water, ethanol were ultrasonically blended for 35 min, Tris-HCl buffer (10 mM, pH=8.5) was added, stirring for 12 h, centrifugal separation, washing and drying the solid phase to obtain the polydopamine coating; the fluoride material, dopamine hydrochloride, deionized water, ethanol, Tris-HCl buffer were in a mass ratio of 190 mg:160 mg:250 mL:25 mL:175 mL;

[0044] S5, the polyurethane emulsion and the polydopamine coating were mixed, and stirring was carried out at 40℃ for 25 min to obtain the finishing agent; the mass ratio of the polyurethane emulsion and the polydopamine coating was 16.9:2.6.

[0045] Preparation Example 3

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

[0047] S1, N,N-dimethylformamide, polytetrahydrofuran, 1H,1H,8H,8H-dodecafluoro-1,8-octanediol octafluorohexanediol were mixed, and isophorone diisocyanate and dibutyltin dilaurate were added under a nitrogen atmosphere, stirring was carried out at 80℃ for 3 h to obtain a polyurethane preform; the mass ratio of N,N-dimethylformamide, polytetrahydrofuran, fluorine-containing diol, isophorone diisocyanate and dibutyltin dilaurate was 5.4:6.5:1.5:4.4:0.02;

[0048] S2, under heating at 43℃, the polyurethane preform was taken, a chain extender L-cystine was added and stirring was carried out for 2.5 h, then a blocking agent 7-hydroxy-4-methyl coumarin was added and stirring was continued for 1.5 h to obtain a polyurethane emulsion; the mass ratio of the polyurethane preform, the chain extender and the blocking agent was 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, stirring was carried out for 5 min, 0.05 mol of sodium hydroxide and 0.02 mol of anhydrous sodium carbonate were added, and stirring was carried out under heating in a water bath at 60℃ for 20 h to obtain a mixture;

[0050] 3.5 g of nano-silicon dioxide and 50 mL of deionized water were mixed and ultrasonically dispersed for 25 min, the mixture was added, stirring was carried out for 15 h, suction filtration was carried out, the solid phase was calcined at 425℃ in an air atmosphere for 3.5 h, the obtained composite oxide was immersed in 20 mL of a 28% mass fraction potassium fluoride aqueous solution, stirring was carried out at room temperature for 25 h, suction filtration was carried out, the solid phase was washed and dried, and then calcination was carried out at 425℃ in an air atmosphere for 6 h to obtain a fluoride material;

[0051] S4, the fluoride material, dopamine hydrochloride, deionized water, ethanol were ultrasonically blended for 35 min, Tris-HCl buffer (10 mM, pH=8.5) was added, stirring for 13 h, centrifugal separation, washing and drying the solid phase to obtain the polydopamine coating; the fluoride material, dopamine hydrochloride, deionized water, ethanol, Tris-HCl buffer were in a ratio of 200 mg: 170 mg: 250 mL: 25 mL: 185 mL;

[0052] S5, the polyurethane emulsion and the polydopamine coating were mixed, and stirring was carried out at 40℃ for 25 min to obtain the finishing agent; the mass ratio of the polyurethane emulsion and the polydopamine coating was 18:2.8.

[0053] Preparation Example 4

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

[0055] S1, N,N-dimethylformamide, polytetrahydrofuran, 1H, 1H, 8H, 8H-dodecafluoro-1,8-octanediol octafluorohexanediol were mixed, isophorone diisocyanate, dibutyltin dilaurate were added in a nitrogen atmosphere, stirring was carried out at 80℃ for 3 h to obtain a polyurethane preform; the mass ratio of N,N-dimethylformamide, polytetrahydrofuran, fluorine-containing diol, isophorone diisocyanate, dibutyltin dilaurate was 5.6:6.8:1.8:4.5:0.02;

[0056] S2, under heating at 44℃, the polyurethane preform was taken, a chain extender L-cystine was added and stirring was carried out for 2.5 h, then a blocking agent 7-hydroxy-4-methyl coumarin was added and stirring was carried out for 1.8 h to obtain a polyurethane emulsion; the mass ratio of the polyurethane preform, the chain extender and the blocking agent was 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, stirring was carried out for 5 min, 0.05 mol of sodium hydroxide and 0.02 mol of anhydrous sodium carbonate were added, stirring was carried out at 62℃ water bath for 20 h to obtain a mixture;

[0058] 3.8 g of nano-silicon dioxide and 50 mL of deionized water were mixed and ultrasonically dispersed for 28 min, the mixture was added, stirring was carried out for 18 h, suction filtration was carried out, the solid phase was calcined at 440℃ in air atmosphere for 3.5 h, the obtained composite oxide was immersed in 20 mL of 32% mass fraction potassium fluoride aqueous solution, stirring was carried out at room temperature for 28 h, suction filtration was carried out, the solid phase was washed and dried, then calcination was carried out at 440℃ in air atmosphere for 6 h to obtain a fluoride material;

[0059] S4, the fluoride material, dopamine hydrochloride, deionized water, ethanol were ultrasonically blended for 38 min, Tris-HCl buffer (10 mM, pH=8.5) was added, stirring for 14 h, centrifugal separation, washing and drying the solid phase to obtain the polydopamine coating; the fluoride material, dopamine hydrochloride, deionized water, ethanol, Tris-HCl buffer were in a mass ratio of 210 mg:180 mg:250 mL:28 mL:198 mL;

[0060] S5, the polyurethane emulsion and the polydopamine coating were mixed, and stirring was carried out at 40℃ for 28 min to obtain the finishing agent; the mass ratio of the polyurethane emulsion and the polydopamine coating was 19:2.9.

[0061] Preparation Example 5

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

[0063] S1, N,N-dimethylformamide, polytetrahydrofuran, 1H,1H,8H,8H-dodecafluoro-1,8-octanediol octafluorohexanediol were mixed, and isophorone diisocyanate and dibutyltin dilaurate were added under nitrogen atmosphere, stirring was carried out at 80℃ for 4 h to obtain a polyurethane preform; the mass ratio of N,N-dimethylformamide, polytetrahydrofuran, fluorine-containing diol, isophorone diisocyanate and dibutyltin dilaurate was 5.7:7:2:4.6:0.02;

[0064] S2, under heating at 45℃, the polyurethane preform was taken, a chain extender L-cystine was added and stirring was carried out for 3 h, and then a blocking agent 7-hydroxy-4-methyl coumarin was added and stirring was carried out for 2 h to obtain a polyurethane emulsion; the mass ratio of the polyurethane preform, the chain extender and the blocking agent was 16.2:1.3:2.0;

[0065] S3, 0.03 mol of magnesium nitrate hexahydrate, 0.01 mol of aluminum nitrate nonahydrate and 100 mL of deionized water were mixed, stirring was carried out for 6 min, 0.05 mol of sodium hydroxide and 0.02 mol of anhydrous sodium carbonate were added, and stirring was carried out under heating in a water bath at 65℃ for 20 h to obtain a mixture material;

[0066] 4 g of nano-silicon dioxide and 50 mL of deionized water were mixed and ultrasonically dispersed for 30 min, the mixture material was added, stirring was carried out for 20 h, suction filtration was carried out, the solid phase was calcined at 450℃ in air atmosphere for 4 h, the obtained composite oxide was immersed in 20 mL of a 35% mass fraction potassium fluoride aqueous solution, stirring was carried out at room temperature for 30 h, suction filtration was carried out, the solid phase was washed and dried, and then calcination was carried out at 450℃ in air atmosphere for 7 h to obtain a fluoride material;

[0067] S4, taking the fluoride material, dopamine hydrochloride, deionized water, ethanol ultrasonic blending 40 min, adding Tris-HCl buffer (10 mM, pH=8.5), stirring 15 h, centrifugal separation, taking the solid phase washing, drying, obtaining polydopamine coated material; the fluoride material, dopamine hydrochloride, deionized water, ethanol, Tris-HCl buffer ratio is 220 mg: 190 mg: 250 mL: 30 mL: 205 mL;

[0068] S5, taking the polyurethane emulsion, polydopamine coated material mixed, stirring at 40℃ for 30 min, obtaining the finishing agent; the mass ratio of polyurethane emulsion, polydopamine coated material is 19.5:3.1.

[0069] Preparation example 6

[0070] The difference from preparation example 3 is that the end-capping agent used in the preparation process of the finishing agent for finishing is 1-nonanol.

[0071] Preparation example 7

[0072] The difference from preparation example 3 is that the composite oxide prepared in step S3 is not immersed in the fluoride ion solution in the preparation process of the finishing agent for finishing.

[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 for finishing is as follows:

[0075] S3, taking 3.5 g of nano silicon dioxide, 50 mL of deionized water mixed ultrasonic dispersion for 25 min, adding the mixture, stirring for 15 h, suction filtration, taking the solid phase to 425℃ in air atmosphere for 3.5 h, immersing the obtained calcined silicon dioxide in 20 mL of 28% mass fraction of potassium fluoride aqueous solution, stirring at room temperature for 25 h, suction filtration, washing and drying the solid phase, then calcining at 425℃ in air atmosphere for 6 h, obtaining the fluoride material.

[0076] Preparation example 9

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

[0078] S1, taking N,N-dimethylformamide, polytetrahydrofuran, 1H,1H,8H,8H-dodecafluoro-1,8-octanediol octafluorohexanediol mixed, adding isophorone diisocyanate, dibutyltin dilaurate in nitrogen atmosphere, stirring at 80℃ for 3 h, obtaining polyurethane preform; the mass ratio of N,N-dimethylformamide, polytetrahydrofuran, fluorine-containing diol, isophorone diisocyanate, dibutyltin dilaurate is 5.4:6.5:1.5:4.4:0.02;

[0079] S2, under the condition of heating at 43℃, taking the polyurethane preform, adding chain extender L-cystine stirring for 2.5h, then adding end-capping agent 7-hydroxy-4-methyl coumarin continuing stirring for 1.5h, obtaining polyurethane emulsion, which is the finishing agent; the mass ratio of the polyurethane preform, chain extender, end-capping agent is 15.3:1.2:1.9.

[0080] Example 1

[0081] A preparation method of wear-resistant and scratch-resistant leather, the animal leather after liming, softening, tanning, and retanning is subjected to finishing treatment.

[0082] The animal leather is selected from sheepskin.

[0083] The finishing treatment is to roll coat the finishing agent prepared in Preparation Example 1 to the surface of the leather, the roll coating amount is 20g / m 2 , and curing at 45℃ for 24h, thus obtaining the wear-resistant and scratch-resistant leather.

[0084] Example 2

[0085] A preparation method of wear-resistant and scratch-resistant leather, the animal leather after liming, softening, tanning, and retanning is subjected to finishing treatment.

[0086] The animal leather is selected from sheepskin.

[0087] The finishing treatment is to roll coat the finishing agent prepared in Preparation Example 2 to the surface of the leather, the roll coating amount is 20g / m 2 , and curing at 45℃ for 24h, thus obtaining the wear-resistant and scratch-resistant leather.

[0088] Example 3

[0089] A preparation method of wear-resistant and scratch-resistant leather, the animal leather after liming, softening, tanning, and retanning is subjected to finishing treatment.

[0090] The animal leather is selected from sheepskin.

[0091] The finishing treatment is to roll coat the finishing agent prepared in Preparation Example 3 to the surface of the leather, the roll coating amount is 20g / m 2 , and curing at 45℃ for 24h, thus obtaining the wear-resistant and scratch-resistant leather.

[0092] Example 4

[0093] A preparation method of wear-resistant and scratch-resistant leather, the animal leather after liming, softening, tanning, and retanning is subjected to finishing treatment.

[0094] The animal leather is selected from sheepskin.

[0095] The finishing treatment is performed by roll coating the finishing agent prepared in Preparation Example 4 onto the surface of the leather at a roll coating amount of 20 g / m 2 , and curing at 45°C for 24 h to obtain the abrasion-resistant and scratch-resistant leather.

[0096] Example 5

[0097] A method for preparing an abrasion-resistant and scratch-resistant leather, comprising performing a finishing treatment on an animal leather after liming, bating, tanning, and retanning;

[0098] The animal leather is selected from sheepskin.

[0099] The finishing treatment is performed by roll coating the finishing agent prepared in Preparation Example 5 onto the surface of the leather at a roll coating amount of 20 g / m 2 , and curing at 45°C for 24 h to obtain the abrasion-resistant and scratch-resistant leather.

[0100] Comparative Example 1

[0101] A method for preparing an abrasion-resistant and scratch-resistant leather, comprising performing a finishing treatment on an animal leather after liming, bating, tanning, and retanning;

[0102] The animal leather is selected from sheepskin.

[0103] The finishing treatment is performed by roll coating the finishing agent prepared in Preparation Example 6 onto the surface of the leather at a roll coating amount of 20 g / m 2 , and curing at 45°C for 24 h to obtain the abrasion-resistant and scratch-resistant leather.

[0104] Comparative Example 2

[0105] A method for preparing an abrasion-resistant and scratch-resistant leather, comprising performing a finishing treatment on an animal leather after liming, bating, tanning, and retanning;

[0106] The animal leather is selected from sheepskin.

[0107] The finishing treatment is performed by roll coating the finishing agent prepared in Preparation Example 7 onto the surface of the leather at a roll coating amount of 20 g / m 2 , and curing at 45°C for 24 h to obtain the abrasion-resistant and scratch-resistant leather.

[0108] Comparative Example 3

[0109] A method for preparing an abrasion-resistant and scratch-resistant leather, comprising performing a finishing treatment on an animal leather after liming, bating, tanning, and retanning;

[0110] The animal leather is selected from sheepskin.

[0111] The finishing treatment is performed by roll coating the finishing agent prepared in Preparation Example 8 onto the surface of the leather at a roll coating amount of 20 g / m 2 , and curing at 45°C for 24 h to obtain the abrasion-resistant and scratch-resistant leather.

[0112] Comparative Example 4

[0113] A method for preparing a wear-resistant and scratch-resistant leather, the animal leather after liming, softening, tanning and re-tanning is subjected to finishing treatment;

[0114] The animal leather is selected from sheepskin;

[0115] The finishing treatment is prepared by roll coating the finishing agent prepared in Example 9 to the surface of the leather, and the roll coating amount is 20 g / m 2 , and curing at 45℃ for 24h to obtain the wear-resistant and scratch-resistant leather.

[0116] Performance test

[0117] Test Example 1

[0118] The leather prepared in Examples 1-5 and Comparative Examples 1-4 is subjected to wear resistance test according to standard GB / T39507-2020, and 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 shown in Table 1, the leather prepared in Examples 1-5 has good wear resistance; the addition of the end-capping agent containing a polybasic ring structure in Comparative Example 1 leads to a decrease in wear resistance; the lack of fluorine immersion treatment in Comparative Example 2 leads to poor dispersion of the polydopamine coating in the emulsion and serious agglomeration, resulting in a decrease in wear resistance; the lack of original hydrotalcite structure in Comparative Example 3 leads to a decrease in wear resistance; and the lack of polydopamine coating in Comparative Example 4 leads to a significant decrease in wear resistance.

[0122] Test Example 2

[0123] The leather prepared in Examples 1-5 and Comparative Example 1 is subjected to self-repairing performance test, and the test results are shown in Table 2.

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

[0125]

[0126] Table 2

[0127] Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Self-repairing performance / % 94.78 95.08 96.23 95.74 94.61 82.38

[0128] As shown in Table 2, the leather prepared in Examples 1-5 has excellent self-repairing performance, so that when it is scratched, it can be self-repaired to improve the scratch resistance; in Comparative Example 1, a conventional monohydric alcohol is selected for end-capping, which exhibits certain self-repairing performance, but far less than the self-repairing healing performance of coumarin and its derivatives.

[0129] The above description is only the preferred embodiments of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with the preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the technical solution of the present application. Any modification, equivalent change and modification of the above embodiments, which does not depart from the technical solution of the present application, are still within the scope of the technical solution of the present application.

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, wherein: 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 the polydopamine coating 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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