Antibacterial waterproof leather and preparation method thereof

Abstract

The invention discloses antibacterial and waterproof leather and a preparation method thereof, and relates to the technical field of leather, in order to improve the antibacterial and waterproof performance of leather, a waterproof and antibacterial leather coating is prepared, and the surface of a leather material is modified; the preparation method comprises the following steps: firstly, reacting 2-methyl-3-butyne-2-amine serving as a raw material with nitrilotriacetic acid containing a carboxyl group, and then reacting carboxyl with an amino group and reacting carboxyl with an epoxy group, so as to prepare the polyhydric alcohol containing guanidyl, imidazole ring, fluorine element and alkyne group at the same time; and then mixing the waterborne polyurethane emulsion with polytetrahydrofuran glycol, so as to finally prepare the waterborne polyurethane emulsion. The surface of leather is coated with the obtained waterborne polyurethane emulsion, guanidyl and imidazole rings can be effectively used for inhibiting microbial activity on the surface of the leather, the hydrophobic performance of the surface of the leather can be improved through introduction of fluorine, and the leather has excellent waterproof performance.

Description

Technical Field

[0001] The invention relates to the technical field of leather, in particular to antibacterial and waterproof leather and a preparation method thereof. Background Art

[0002] As a high-end clothing and home furnishing material, leather is a denatured and non-perishable animal skin obtained through physical and chemical processes such as depilation and tanning. It is made of natural protein fibers tightly interwoven in a three-dimensional structure, with a unique grain layer on the surface, showing natural texture and luster, and soft and comfortable to the touch. Due to the above advantages, leather products have always occupied a large consumer market in human life, but natural leather is easily affected by moisture and breeds mold, which greatly limits the service life of leather. Summary of the invention

[0003] The object of the present invention is to provide an antibacterial and waterproof leather and a preparation method thereof, so as to solve the problems raised in the prior art.

[0004] To achieve the above object, the present invention provides the following technical solution: a method for preparing antibacterial and waterproof leather, comprising the following steps: S1. Preparation of waterproof and antibacterial leather coating; S11. Disperse 2-methyl-3-butyn-2-amine in tetrahydrofuran, stir and mix evenly in the dark to obtain a 2-methyl-3-butyn-2-amine dispersion; Under nitrogen atmosphere protection, nitrilotriacetic acid is dispersed in DMF, N,N'-dicyclohexylcarbodiimide is added thereto, and after mixing for 15-30 minutes, 2-methyl-3-butyn-2-amine dispersion is added dropwise thereto, and the temperature is raised to 76-79°C. Under light-proof conditions, the mixture is refluxed for 1.5-4 hours, and the excess solvent is removed by rotary evaporation to obtain a carboxyl-terminated intermediate; S12 2-guanidinobenzimidazole was dispersed in dimethyl sulfoxide, stirred under a nitrogen atmosphere until completely dissolved to obtain a 2-guanidinobenzimidazole solution for later use; The terminal carboxyl intermediate is dispersed in pure DMF, protected by nitrogen atmosphere, heated to 35-40°C, stirred and dispersed for 1-2 hours, cooled to 5-10°C, trifluoropropylene oxide is added dropwise thereto, and stirring is continued during the dropping process. After the dropping is completed, the temperature is raised to 88-98°C, stirred and reacted for 2.5-5 hours, cooled to 75-80°C, 2-guanidinobenzimidazole solution is added thereto, stirred and reacted for 4-5 hours, and the excess solvent is removed by rotary evaporation. The reaction product is washed with anhydrous ethanol for 2-4 times, and dried to constant weight to obtain a waterproof and antibacterial intermediate; S13. The waterproof and antibacterial intermediate is dispersed in clean DMF, heated to 75-100°C, protected by nitrogen atmosphere, ultrasonically dispersed for 3-8 hours, and then 2,5-anhydro-1-azido-1-deoxy-D-glucitol is added thereto. After stirring and reacting for 12-36 hours in a nitrogen atmosphere and away from light, the excess solvent is removed by rotary evaporation to obtain a waterproof and antibacterial monomer; S14. According to the weight ratio, the waterproof antibacterial monomer and N-methylpyrrolidone were ultrasonically stirred and mixed for 1-3 hours, and polytetrahydrofuran diol was added. After stirring and mixing for 1.5-2 hours, a chain extender was added, the temperature was raised to 95-105°C, vacuum dehydration was carried out for 1-1.5 hours, the temperature was cooled to 75-80°C, isophorone diisocyanate was added, the temperature was raised to 85-90°C, the temperature was stirred and reacted for 4-8 hours, the temperature was lowered to 55-65°C, a neutralizer was added, the reaction was continued for 1-1.5 hours, the temperature was cooled to room temperature, deionized water was added, and high-speed shear dispersion was performed to obtain a waterproof antibacterial leather coating; S2. The obtained waterproof and antibacterial leather coating is applied on leather, and the leather is placed in an environment of 100-140° C. and heated and dried for 2-4 hours to obtain antibacterial and waterproof leather.

[0005] Furthermore, in step S11, the mass ratio of the 2-methyl-3-butyn-2-amine, nitrilotriacetic acid, and N,N'-dicyclohexylcarbodiimide is 1:(1.9-2.3):(0.002-0.005).

[0006] Furthermore, in step S12, the mass ratio of the carboxyl-terminated intermediate, 2-guanidinobenzimidazole, and trifluoropropylene oxide is 1: (0.53-0.64): (0.3-0.42).

[0007] Furthermore, in step S13, the mass ratio of the waterproof and antibacterial intermediate to 2,5-anhydro-1-azido-1-deoxy-D-glucitol is 1:(0.3-0.34).

[0008] Further, in step S14, the waterproof and antibacterial leather coating is composed of 8-15 parts of waterproof and antibacterial monomers, 5-10 parts of N-methylpyrrolidone, 60 parts of polytetramethylene glycol, 1.5-4 parts of chain extenders, 34-45 parts of isophorone diisocyanate, 3.1-4.5 parts of neutralizers, and 300 parts of deionized water, by weight.

[0009] Further, in step S14, the weight average molecular weight of the polytetrahydrofuran diol is 1500-2500. Furthermore, in step S14, the chain extender is any one of dimethylol propionic acid and dimethylol butyric acid.

[0010] Furthermore, in step S14, the neutralizing agent is triethylamine.

[0011] Furthermore, an antibacterial and waterproof leather is prepared by the above preparation method.

[0012] Compared with the prior art, the present invention has the following beneficial effects: In order to improve the antibacterial and waterproof properties of leather, the present invention prepares a waterproof and antibacterial leather coating and performs modification treatment on the surface of the leather material; the present invention first uses 2-methyl-3-butyn-2-amine as a raw material, wherein the 2-methyl-3-butyn-2-amine has an alkynyl group and an amino group, and reacts the 2-methyl-3-butyn-2-amine with nitrilotriacetic acid containing a carboxyl group to prepare a terminal carboxyl intermediate containing a carboxyl group and a carboxyl group, and then utilizes the reaction between the carboxyl group and the amino group and the reaction between the carboxyl group and the epoxy group to prepare a waterproof and antibacterial intermediate containing a guanidine group, an imidazole ring, a fluorine element and an alkynyl group at the same time, It is then reacted with 2,5-anhydro-1-azido-1-deoxy-D-glucitol containing an azide group to produce a polyol containing a guanidine group, an imidazole ring and a fluorine element. On this basis, it is mixed with polytetrahydrofuran diol and reacted with isocyanate again to finally produce an aqueous polyurethane emulsion. The obtained aqueous polyurethane emulsion is applied to the leather surface, which can effectively utilize the guanidine group and the imidazole ring to inhibit the microbial activity on the leather surface. The introduction of the fluorine element can also enhance the hydrophobic properties of the leather surface, making the leather have excellent waterproof properties. DETAILED DESCRIPTION

[0013] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0014] Example 1. A method for preparing antibacterial and waterproof leather, comprising the following steps: S1. Preparation of waterproof and antibacterial leather coating; S11. In parts by weight, 1 part of 2-methyl-3-butyn-2-amine was dispersed in tetrahydrofuran, and stirred to mix evenly in the dark to obtain a 2-methyl-3-butyn-2-amine dispersion; Under nitrogen atmosphere protection, 1.9 parts of nitrilotriacetic acid were dispersed in DMF, 0.005 parts of N,N'-dicyclohexylcarbodiimide was added thereto, and the mixture was mixed for 25 minutes, and then 2-methyl-3-butyn-2-amine dispersion was added dropwise thereto, and the mixture was heated to 76-79°C, and refluxed for 3 hours under light-proof conditions, and then the excess solvent was removed by rotary evaporation to obtain a carboxyl-terminated intermediate; S12 0.53 parts of 2-guanidinobenzimidazole was dispersed in dimethyl sulfoxide, stirred under a nitrogen atmosphere until completely dissolved to obtain a 2-guanidinobenzimidazole solution for later use; Disperse 1 part of the terminal carboxyl intermediate in pure DMF, protect under nitrogen atmosphere, heat to 35-40°C, stir and disperse for 1.5 hours, cool to 5-10°C, drop 0.3 parts of trifluoropropylene oxide therein, stir continuously during the dropwise addition, heat to 95°C after completion of the dropwise addition, stir and react for 2.5 hours, cool to 78°C, add 2-guanidinobenzimidazole solution therein, stir and react for 5 hours, remove excess solvent by rotary evaporation, wash the reaction product with anhydrous ethanol for 3 times, and dry to constant weight to obtain a waterproof and antibacterial intermediate; S13. Disperse 1 part of the waterproof and antibacterial intermediate into clean DMF, heat to 85°C, protect under nitrogen atmosphere, ultrasonically disperse for 5 hours, add 0.3 parts of 2,5-anhydro-1-azido-1-deoxy-D-glucitol, stir and react for 24 hours in a nitrogen atmosphere, avoid light, and then remove excess solvent by rotary evaporation to obtain a waterproof and antibacterial monomer; S14. By weight, 8 parts of waterproof and antibacterial monomer and 10 parts of N-methylpyrrolidone were ultrasonically stirred and mixed for 3 hours, and then 60 parts of polytetrahydrofuran diol were added. After stirring and mixing for 2 hours, 3 parts of dimethylol propionic acid chain extender were added, the temperature was raised to 105°C, vacuum dehydration was carried out for 1.5 hours, the temperature was cooled to 80°C, 38 parts of isophorone diisocyanate were added, the temperature was raised to 90°C, stirred and reacted for 6 hours, the temperature was lowered to 55°C, 3.1 parts of triethylamine neutralizer were added, the reaction was continued for 15 hours, and then cooled to room temperature, 300 parts of deionized water were added, and high-speed shear dispersion was performed to obtain a waterproof and antibacterial leather coating; S2. The obtained waterproof and antibacterial leather coating is applied on leather, and heated and dried in an environment of 120° C. for 2.5 hours to form a coating with a dry film thickness of 30 μm on the leather, and then the coating is arranged and rolled up to obtain antibacterial and waterproof leather.

[0015] Example 2. A method for preparing antibacterial and waterproof leather, comprising the following steps: Compared with Example 1, the amount of nitrilotriacetic acid added in step S11 is increased in this example; S1. Preparation of waterproof and antibacterial leather coating; S11. In parts by weight, 1 part of 2-methyl-3-butyn-2-amine was dispersed in tetrahydrofuran, and stirred to mix evenly in the dark to obtain a 2-methyl-3-butyn-2-amine dispersion; Under nitrogen atmosphere protection, 2.3 parts of nitrilotriacetic acid were dispersed in DMF, 0.005 parts of N,N'-dicyclohexylcarbodiimide was added thereto, and the mixture was mixed for 25 minutes, and then 2-methyl-3-butyn-2-amine dispersion was added dropwise thereto, and the mixture was heated to 76-79°C, and refluxed for 3 hours under light-proof conditions, and then the excess solvent was removed by rotary evaporation to obtain a carboxyl-terminated intermediate; S12 0.53 parts of 2-guanidinobenzimidazole was dispersed in dimethyl sulfoxide, stirred under a nitrogen atmosphere until completely dissolved to obtain a 2-guanidinobenzimidazole solution for later use; Disperse 1 part of the terminal carboxyl intermediate in pure DMF, protect under nitrogen atmosphere, heat to 35-40°C, stir and disperse for 1.5 hours, cool to 5-10°C, drop 0.3 parts of trifluoropropylene oxide therein, stir continuously during the dropwise addition, heat to 95°C after completion of the dropwise addition, stir and react for 2.5 hours, cool to 78°C, add 2-guanidinobenzimidazole solution therein, stir and react for 5 hours, remove excess solvent by rotary evaporation, wash the reaction product with anhydrous ethanol for 3 times, and dry to constant weight to obtain a waterproof and antibacterial intermediate; S13. Disperse 1 part of the waterproof and antibacterial intermediate into clean DMF, heat to 85°C, protect under nitrogen atmosphere, ultrasonically disperse for 5 hours, add 0.3 parts of 2,5-anhydro-1-azido-1-deoxy-D-glucitol, stir and react for 24 hours in a nitrogen atmosphere, avoid light, and then remove excess solvent by rotary evaporation to obtain a waterproof and antibacterial monomer; S14. By weight, 8 parts of waterproof and antibacterial monomer and 10 parts of N-methylpyrrolidone were ultrasonically stirred and mixed for 3 hours, and then 60 parts of polytetrahydrofuran diol were added. After stirring and mixing for 2 hours, 3 parts of dimethylol propionic acid chain extender were added, the temperature was raised to 105°C, vacuum dehydration was carried out for 1.5 hours, the temperature was cooled to 80°C, 38 parts of isophorone diisocyanate were added, the temperature was raised to 90°C, stirred and reacted for 6 hours, the temperature was lowered to 55°C, 3.1 parts of triethylamine neutralizer were added, the reaction was continued for 15 hours, and then cooled to room temperature, 300 parts of deionized water were added, and high-speed shear dispersion was performed to obtain a waterproof and antibacterial leather coating; S2. The obtained waterproof and antibacterial leather coating is applied on leather, and heated and dried in an environment of 120° C. for 2.5 hours to form a coating with a dry film thickness of 30 μm on the leather, and then the coating is arranged and rolled up to obtain antibacterial and waterproof leather.

[0016] Example 3. A method for preparing antibacterial and waterproof leather, comprising the following steps: Compared with Example 2, this example increases the amount of trifluoropropylene oxide added in step S12; S1. Preparation of waterproof and antibacterial leather coating; S11. In parts by weight, 1 part of 2-methyl-3-butyn-2-amine was dispersed in tetrahydrofuran, and stirred to mix evenly in the dark to obtain a 2-methyl-3-butyn-2-amine dispersion; Under nitrogen atmosphere protection, 2.3 parts of nitrilotriacetic acid were dispersed in DMF, 0.005 parts of N,N'-dicyclohexylcarbodiimide was added thereto, and the mixture was mixed for 25 minutes, and then 2-methyl-3-butyn-2-amine dispersion was added dropwise thereto, and the mixture was heated to 76-79°C, and refluxed for 3 hours under light-proof conditions, and then the excess solvent was removed by rotary evaporation to obtain a carboxyl-terminated intermediate; S12 0.53 parts of 2-guanidinobenzimidazole was dispersed in dimethyl sulfoxide, stirred under a nitrogen atmosphere until completely dissolved to obtain a 2-guanidinobenzimidazole solution for later use; Disperse 1 part of the terminal carboxyl intermediate in pure DMF, protect under nitrogen atmosphere, heat to 35-40°C, stir and disperse for 1.5 hours, cool to 5-10°C, drop 0.42 parts of trifluoropropylene oxide therein, stir continuously during the dropwise addition, heat to 95°C after the dropwise addition is completed, stir and react for 2.5 hours, cool to 78°C, add 2-guanidinobenzimidazole solution therein, stir and react for 5 hours, remove excess solvent by rotary evaporation, wash the reaction product with anhydrous ethanol for 3 times, and dry to constant weight to obtain a waterproof and antibacterial intermediate; S13. Disperse 1 part of the waterproof and antibacterial intermediate into clean DMF, heat to 85°C, protect under nitrogen atmosphere, ultrasonically disperse for 5 hours, add 0.3 parts of 2,5-anhydro-1-azido-1-deoxy-D-glucitol, stir and react for 24 hours in a nitrogen atmosphere, avoid light, and then remove excess solvent by rotary evaporation to obtain a waterproof and antibacterial monomer; S14. By weight, 8 parts of waterproof and antibacterial monomer and 10 parts of N-methylpyrrolidone were ultrasonically stirred and mixed for 3 hours, and then 60 parts of polytetrahydrofuran diol were added. After stirring and mixing for 2 hours, 3 parts of dimethylol propionic acid chain extender were added, the temperature was raised to 105°C, vacuum dehydration was carried out for 1.5 hours, the temperature was cooled to 80°C, 38 parts of isophorone diisocyanate were added, the temperature was raised to 90°C, stirred and reacted for 6 hours, the temperature was lowered to 55°C, 3.1 parts of triethylamine neutralizer were added, the reaction was continued for 15 hours, and then cooled to room temperature, 300 parts of deionized water were added, and high-speed shear dispersion was performed to obtain a waterproof and antibacterial leather coating; S2. The obtained waterproof and antibacterial leather coating is applied on leather, and heated and dried in an environment of 120° C. for 2.5 hours to form a coating with a dry film thickness of 30 μm on the leather, and then the coating is arranged and rolled up to obtain antibacterial and waterproof leather.

[0017] Example 4. A method for preparing antibacterial and waterproof leather, comprising the following steps: Compared with Example 3, this embodiment increases the amount of 2-guanidinobenzimidazole added in step S12; S1. Preparation of waterproof and antibacterial leather coating; S11. In parts by weight, 1 part of 2-methyl-3-butyn-2-amine was dispersed in tetrahydrofuran, and stirred to mix evenly in the dark to obtain a 2-methyl-3-butyn-2-amine dispersion; Under nitrogen atmosphere protection, 2.3 parts of nitrilotriacetic acid were dispersed in DMF, 0.005 parts of N,N'-dicyclohexylcarbodiimide was added thereto, and the mixture was mixed for 25 minutes, and then 2-methyl-3-butyn-2-amine dispersion was added dropwise thereto, and the mixture was heated to 76-79°C, and refluxed for 3 hours under light-proof conditions, and then the excess solvent was removed by rotary evaporation to obtain a carboxyl-terminated intermediate; S12 0.64 parts of 2-guanidinobenzimidazole was dispersed in dimethyl sulfoxide, stirred under a nitrogen atmosphere until completely dissolved to obtain a 2-guanidinobenzimidazole solution for later use; Disperse 1 part of the terminal carboxyl intermediate in pure DMF, protect under nitrogen atmosphere, heat to 35-40°C, stir and disperse for 1.5 hours, cool to 5-10°C, drop 0.42 parts of trifluoropropylene oxide therein, stir continuously during the dropwise addition, heat to 95°C after the dropwise addition is completed, stir and react for 2.5 hours, cool to 78°C, add 2-guanidinobenzimidazole solution therein, stir and react for 5 hours, remove excess solvent by rotary evaporation, wash the reaction product with anhydrous ethanol for 3 times, and dry to constant weight to obtain a waterproof and antibacterial intermediate; S13. Disperse 1 part of the waterproof and antibacterial intermediate into clean DMF, heat to 85°C, protect under nitrogen atmosphere, ultrasonically disperse for 5 hours, add 0.3 parts of 2,5-anhydro-1-azido-1-deoxy-D-glucitol, stir and react for 24 hours in a nitrogen atmosphere, avoid light, and then remove excess solvent by rotary evaporation to obtain a waterproof and antibacterial monomer; S14. By weight, 8 parts of waterproof and antibacterial monomer and 10 parts of N-methylpyrrolidone were ultrasonically stirred and mixed for 3 hours, and then 60 parts of polytetrahydrofuran diol were added. After stirring and mixing for 2 hours, 3 parts of dimethylol propionic acid chain extender were added, the temperature was raised to 105°C, vacuum dehydration was carried out for 1.5 hours, the temperature was cooled to 80°C, 38 parts of isophorone diisocyanate were added, the temperature was raised to 90°C, stirred and reacted for 6 hours, the temperature was lowered to 55°C, 3.1 parts of triethylamine neutralizer were added, the reaction was continued for 15 hours, and then cooled to room temperature, 300 parts of deionized water were added, and high-speed shear dispersion was performed to obtain a waterproof and antibacterial leather coating; S2. The obtained waterproof and antibacterial leather coating is applied on leather, and heated and dried in an environment of 120° C. for 2.5 hours to form a coating with a dry film thickness of 30 μm on the leather, and then the coating is arranged and rolled up to obtain antibacterial and waterproof leather.

[0018] Example 5. A method for preparing antibacterial and waterproof leather, comprising the following steps: Compared with Example 4, this example increases the amount of 2,5-anhydro-1-azido-1-deoxy-D-glucitol added in step S13; S1. Preparation of waterproof and antibacterial leather coating; S11. In parts by weight, 1 part of 2-methyl-3-butyn-2-amine was dispersed in tetrahydrofuran, and stirred to mix evenly in the dark to obtain a 2-methyl-3-butyn-2-amine dispersion; Under nitrogen atmosphere protection, 2.3 parts of nitrilotriacetic acid were dispersed in DMF, 0.005 parts of N,N'-dicyclohexylcarbodiimide was added thereto, and the mixture was mixed for 25 minutes, and then 2-methyl-3-butyn-2-amine dispersion was added dropwise thereto, and the mixture was heated to 76-79°C, and refluxed for 3 hours under light-proof conditions, and then the excess solvent was removed by rotary evaporation to obtain a carboxyl-terminated intermediate; S12 0.64 parts of 2-guanidinobenzimidazole was dispersed in dimethyl sulfoxide, stirred under a nitrogen atmosphere until completely dissolved to obtain a 2-guanidinobenzimidazole solution for later use; Disperse 1 part of the terminal carboxyl intermediate in pure DMF, protect under nitrogen atmosphere, heat to 35-40°C, stir and disperse for 1.5 hours, cool to 5-10°C, drop 0.42 parts of trifluoropropylene oxide therein, stir continuously during the dropwise addition, heat to 95°C after the dropwise addition is completed, stir and react for 2.5 hours, cool to 78°C, add 2-guanidinobenzimidazole solution therein, stir and react for 5 hours, remove excess solvent by rotary evaporation, wash the reaction product with anhydrous ethanol for 3 times, and dry to constant weight to obtain a waterproof and antibacterial intermediate; S13. Disperse 1 part of the waterproof and antibacterial intermediate into clean DMF, heat to 85°C, protect under nitrogen atmosphere, ultrasonically disperse for 5 hours, add 0.34 parts of 2,5-anhydro-1-azido-1-deoxy-D-glucitol, stir and react for 24 hours in a nitrogen atmosphere, avoid light, and then remove excess solvent by rotary evaporation to obtain a waterproof and antibacterial monomer; S14. By weight, 8 parts of waterproof and antibacterial monomer and 10 parts of N-methylpyrrolidone were ultrasonically stirred and mixed for 3 hours, and then 60 parts of polytetrahydrofuran diol were added. After stirring and mixing for 2 hours, 3 parts of dimethylol propionic acid chain extender were added, the temperature was raised to 105°C, vacuum dehydration was carried out for 1.5 hours, the temperature was cooled to 80°C, 38 parts of isophorone diisocyanate were added, the temperature was raised to 90°C, stirred and reacted for 6 hours, the temperature was lowered to 55°C, 3.1 parts of triethylamine neutralizer were added, the reaction was continued for 15 hours, and then cooled to room temperature, 300 parts of deionized water were added, and high-speed shear dispersion was performed to obtain a waterproof and antibacterial leather coating; S2. The obtained waterproof and antibacterial leather coating is applied on leather, and heated and dried in an environment of 120° C. for 2.5 hours to form a coating with a dry film thickness of 30 μm on the leather, and then the coating is arranged and rolled up to obtain antibacterial and waterproof leather.

[0019] Comparative Example 1. A method for preparing antibacterial and waterproof leather, comprising the following steps: Compared with Example 1, this comparative example does not use 2-guanidinobenzimidazole; S1. Preparation of waterproof and antibacterial leather coating; S11. In parts by weight, 1 part of 2-methyl-3-butyn-2-amine was dispersed in tetrahydrofuran, and stirred to mix evenly in the dark to obtain a 2-methyl-3-butyn-2-amine dispersion; Under nitrogen atmosphere protection, 1.9 parts of nitrilotriacetic acid were dispersed in DMF, 0.005 parts of N,N'-dicyclohexylcarbodiimide was added thereto, and the mixture was mixed for 25 minutes, and then 2-methyl-3-butyn-2-amine dispersion was added dropwise thereto, and the mixture was heated to 76-79°C, and refluxed for 3 hours under light-proof conditions, and then the excess solvent was removed by rotary evaporation to obtain a carboxyl-terminated intermediate; S12. Disperse 1 part of the terminal carboxyl intermediate into pure DMF, protect under nitrogen atmosphere, heat to 35-40°C, stir and disperse for 1.5h, cool to 5-10°C, dropwise add 0.6 parts of trifluoropropylene oxide, stir continuously during the addition, heat to 95°C after the addition is complete, stir and react for 2.5h, remove excess solvent by rotary evaporation, wash the reaction product 3 times with anhydrous ethanol, and dry to constant weight to obtain a waterproof and antibacterial intermediate; S13. Disperse 1 part of the waterproof and antibacterial intermediate into clean DMF, heat to 85°C, protect under nitrogen atmosphere, ultrasonically disperse for 5 hours, add 0.3 parts of 2,5-anhydro-1-azido-1-deoxy-D-glucitol, stir and react for 24 hours in a nitrogen atmosphere, avoid light, and then remove excess solvent by rotary evaporation to obtain a waterproof and antibacterial monomer; S14. By weight, 8 parts of waterproof and antibacterial monomer and 10 parts of N-methylpyrrolidone were ultrasonically stirred and mixed for 3 hours, and then 60 parts of polytetrahydrofuran diol were added. After stirring and mixing for 2 hours, 3 parts of dimethylol propionic acid chain extender were added, the temperature was raised to 105°C, vacuum dehydration was carried out for 1.5 hours, the temperature was cooled to 80°C, 38 parts of isophorone diisocyanate were added, the temperature was raised to 90°C, stirred and reacted for 6 hours, the temperature was lowered to 55°C, 3.1 parts of triethylamine neutralizer were added, the reaction was continued for 15 hours, and then cooled to room temperature, 300 parts of deionized water were added, and high-speed shear dispersion was performed to obtain a waterproof and antibacterial leather coating; S2. The obtained waterproof and antibacterial leather coating is applied on leather, and heated and dried in an environment of 120° C. for 2.5 hours to form a coating with a dry film thickness of 30 μm on the leather, and then the coating is arranged and rolled up to obtain antibacterial and waterproof leather.

[0020] Comparative Example 2. A method for preparing antibacterial and waterproof leather, comprising the following steps: Compared with Example 1, trifluoropropylene oxide was not used in step S12 of this comparative example; S1. Preparation of waterproof and antibacterial leather coating; S11. In parts by weight, 1 part of 2-methyl-3-butyn-2-amine was dispersed in tetrahydrofuran, and stirred to mix evenly in the dark to obtain a 2-methyl-3-butyn-2-amine dispersion; Under nitrogen atmosphere protection, 1.9 parts of nitrilotriacetic acid were dispersed in DMF, 0.005 parts of N,N'-dicyclohexylcarbodiimide was added thereto, and the mixture was mixed for 25 minutes, and then 2-methyl-3-butyn-2-amine dispersion was added dropwise thereto, and the mixture was heated to 76-79°C, and refluxed for 3 hours under light-proof conditions, and then the excess solvent was removed by rotary evaporation to obtain a carboxyl-terminated intermediate; S12 1.06 parts of 2-guanidinobenzimidazole was dispersed in dimethyl sulfoxide, stirred under a nitrogen atmosphere until completely dissolved to obtain a 2-guanidinobenzimidazole solution for later use; Disperse 1 portion of the terminal carboxyl intermediate into pure DMF, protect under nitrogen atmosphere, heat to 35-40°C, stir and disperse for 1.5 hours, heat to 78°C, add 2-guanidinobenzimidazole solution, stir and react for 5 hours, remove excess solvent by rotary evaporation, wash the reaction product with anhydrous ethanol for 3 times, and dry to constant weight to obtain a waterproof and antibacterial intermediate; S13. Disperse 1 part of the waterproof and antibacterial intermediate into clean DMF, heat to 85°C, protect under nitrogen atmosphere, ultrasonically disperse for 5 hours, add 0.3 parts of 2,5-anhydro-1-azido-1-deoxy-D-glucitol, stir and react for 24 hours in a nitrogen atmosphere, avoid light, and then remove excess solvent by rotary evaporation to obtain a waterproof and antibacterial monomer; S14. By weight, 8 parts of waterproof and antibacterial monomer and 10 parts of N-methylpyrrolidone were ultrasonically stirred and mixed for 3 hours, and then 60 parts of polytetrahydrofuran diol were added. After stirring and mixing for 2 hours, 3 parts of dimethylol propionic acid chain extender were added, the temperature was raised to 105°C, vacuum dehydration was carried out for 1.5 hours, the temperature was cooled to 80°C, 38 parts of isophorone diisocyanate were added, the temperature was raised to 90°C, stirred and reacted for 6 hours, the temperature was lowered to 55°C, 3.1 parts of triethylamine neutralizer were added, the reaction was continued for 15 hours, and then cooled to room temperature, 300 parts of deionized water were added, and high-speed shear dispersion was performed to obtain a waterproof and antibacterial leather coating; S2. The obtained waterproof and antibacterial leather coating is applied on leather, and heated and dried in an environment of 120° C. for 2.5 hours to form a coating with a dry film thickness of 30 μm on the leather, and then the coating is arranged and rolled up to obtain antibacterial and waterproof leather.

[0021] Testing: The antibacterial and waterproof leathers prepared in Examples 1-5 and Comparative Examples 1-2 were prepared as testing samples; According to GB / T 31402-2015, the test samples prepared in Examples 1-5 and Comparative Examples 1-2 were tested for antibacterial properties; The water drop contact angle tester was used to test the water drop contact angle of the test samples prepared in Examples 1-5 and Comparative Examples 1-2; The test results are shown in the table below;

[0022] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing antibacterial and waterproof leather, characterized in that: The following steps are involved: S1. Preparation of waterproof and antibacterial leather coating; S11. Disperse 2-methyl-3-butyn-2-amine in tetrahydrofuran, stir and mix evenly in the dark to obtain a 2-methyl-3-butyn-2-amine dispersion; Under nitrogen atmosphere protection, nitrilotriacetic acid is dispersed in DMF, N,N'-dicyclohexylcarbodiimide is added thereto, and after mixing for 15-30 minutes, 2-methyl-3-butyn-2-amine dispersion is added dropwise thereto, and the temperature is raised to 76-79°C. Under light-proof conditions, the mixture is refluxed for 1.5-4 hours, and the excess solvent is removed by rotary evaporation to obtain a carboxyl-terminated intermediate; S12. Disperse 2-guanidinobenzimidazole in dimethyl sulfoxide and stir under a nitrogen atmosphere until completely dissolved to obtain a 2-guanidinobenzimidazole solution for later use; The terminal carboxyl intermediate is dispersed in pure DMF, protected by nitrogen atmosphere, heated to 35-40°C, stirred and dispersed for 1-2 hours, cooled to 5-10°C, trifluoropropylene oxide is added dropwise thereto, and stirring is continued during the dropping process. After the dropping is completed, the temperature is raised to 88-98°C, stirred and reacted for 2.5-5 hours, cooled to 75-80°C, 2-guanidinobenzimidazole solution is added thereto, stirred and reacted for 4-5 hours, and the excess solvent is removed by rotary evaporation. The reaction product is washed with anhydrous ethanol for 2-4 times, and dried to constant weight to obtain a waterproof and antibacterial intermediate; S13. The waterproof and antibacterial intermediate is dispersed in clean DMF, heated to 75-100°C, protected by nitrogen atmosphere, ultrasonically dispersed for 3-8h, and then 2,5-anhydro-1-azido-1-deoxy-D-glucitol is added thereto. After stirring and reacting for 12-36h in a nitrogen atmosphere and away from light, the excess solvent is removed by rotary evaporation to obtain a waterproof and antibacterial monomer; S14. According to the weight ratio, the waterproof and antibacterial monomer and N-methylpyrrolidone were ultrasonically stirred and mixed for 1-3 hours, and polytetrahydrofuran diol was added. After stirring and mixing for 1.5-2 hours, a chain extender was added, the temperature was raised to 95-105°C, vacuum dehydration was carried out for 1-1.5 hours, the temperature was cooled to 75-80°C, isophorone diisocyanate was added, the temperature was raised to 85-90°C, the reaction was stirred for 4-8 hours, the temperature was lowered to 55-65°C, a neutralizer was added, the reaction was continued for 1-1.5 hours, the reaction was cooled to room temperature, deionized water was added, and high-speed shear dispersion was performed to obtain a waterproof and antibacterial leather coating; S2. The obtained waterproof and antibacterial leather coating is applied on leather, and the leather is placed in an environment of 100-140° C. and heated and dried for 2-4 hours to obtain antibacterial and waterproof leather.

2. The method for preparing an antibacterial and waterproof leather according to claim 1, characterized in that: In step S11, the mass ratio of the 2-methyl-3-butyn-2-amine, nitrilotriacetic acid, and N,N'-dicyclohexylcarbodiimide is 1:(1.9-2.3):(0.002-0.005).

3. The method for preparing an antibacterial and waterproof leather according to claim 1, characterized in that: In step S12, the mass ratio of the carboxyl-terminated intermediate, 2-guanidinobenzimidazole, and trifluoropropylene oxide is 1:(0.53-0.64):(0.3-0.42).

4. The method for preparing antibacterial and waterproof leather according to claim 1, characterized in that: In step S13, the mass ratio of the waterproof and antibacterial intermediate to 2,5-anhydro-1-azido-1-deoxy-D-glucitol is 1:(0.3-0.34).

5. The method for preparing antibacterial and waterproof leather according to claim 1, characterized in that: In step S14, the waterproof and antibacterial leather coating is composed of 8-15 parts of waterproof and antibacterial monomers, 5-10 parts of N-methylpyrrolidone, 60 parts of polytetramethylene glycol, 1.5-4 parts of chain extenders, 34-45 parts of isophorone diisocyanate, 3.1-4.5 parts of neutralizers, and 300 parts of deionized water, by weight.

6. The method for preparing antibacterial and waterproof leather according to claim 1, characterized in that: In step S14, the weight average molecular weight of the polytetrahydrofuran diol is 1500-2500.

7. The method for preparing antibacterial and waterproof leather according to claim 1, characterized in that: In step S14, the chain extender is any one of dimethylol propionic acid and dimethylol butyric acid.

8. The method for preparing antibacterial and waterproof leather according to claim 1, characterized in that: In step S14, the neutralizing agent is triethylamine.

9. An antibacterial and waterproof leather prepared by the preparation method according to any one of claims 1 to 8.

Images