Efficient moistureproof antibacterial leather and preparation process thereof

Abstract

The invention discloses efficient moisture-proof antibacterial leather and a preparation process, the process comprises the steps of soaking, degreasing, tanning, fat liquoring, drying and the like, a sodium cocoyl glycinate aqueous solution, acetone and an enzyme preparation are added in the degreasing process, a tanning agent and an antibacterial agent are added in the tanning process, the tanning agent is tanning extract, and the antibacterial agent is an antibacterial agent. The antibacterial agent is a mixed solution of modified chitosan, glycyrrhizic acid and a nano-silver solution. Compared with the prior art, the process disclosed by the invention adopts a dual degreasing process, the sodium cocoyl glycinate aqueous solution is added, so that the sodium cocoyl glycinate aqueous solution, acetone and an enzyme preparation perform efficient degreasing treatment on the leather, and meanwhile, the growth of bacteria and fungi in the leather can be effectively inhibited under the action of the composite antibacterial agent; the antibacterial function of the leather is improved.

Description

Technical Field

[0001] The invention relates to the technical field of leather preparation, and in particular to a highly efficient moisture-proof and antibacterial leather and a preparation process thereof. Background Art

[0002] Leather is a denatured, non-perishable animal skin obtained through physical and chemical processes such as depilation and tanning. It has a special grain layer on its surface, with natural grain and luster, and feels comfortable. After tanning, animal skins are made into leather goods with various characteristics, strength, feel, color, and patterns, and are essential materials for modern leather products. However, traditional leather products have relatively single functions, often only have inefficient and simple moisture-proof effects, and do not have antibacterial properties. They absorb moisture for a long time, are easily eroded by bacteria, and become moldy, which seriously affects the quality of leather products and also seriously threatens human health.

[0003] In view of this, the applicant conducted in-depth research on the above issues, which led to the present case. Summary of the invention

[0004] The main purpose of the present invention is to provide a highly effective moisture-proof and antibacterial leather and a preparation process, so that the leather has a better moisture-proof effect and at the same time improves the antibacterial ability of the leather.

[0005] In order to achieve the above object, the solution of the present invention is:

[0006] A preparation process of highly efficient moisture-proof and antibacterial leather comprises the following steps:

[0007] (1) Soaking the hide in water;

[0008] (2) putting the soaked leather into a drum, adding a sodium cocoyl glycinate aqueous solution, acetone and an enzyme preparation, heating the drum to 30-35° C., and rotating for 0.5 hours, wherein the concentration of the sodium cocoyl glycinate aqueous solution is 25-30 wt %;

[0009] (3) adding warm water at 35° C. to the drum, adding the sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation again, heating the drum to 35-38° C., and rotating for 2.5 hours;

[0010] (4) taking out the leather, washing it with clean water, then dehairing, liming and deashing the leather, and then adding a softener into the drum to soften the leather, wherein the softener is a conventional softener on the market;

[0011] (5) formic acid, water and concentrated sulfuric acid are mixed in a volume ratio of 10 ml: 200 ml: 10 ml, formic acid is measured, and added into a glass container containing an appropriate amount of water, and after stirring evenly, concentrated sulfuric acid is slowly added intermittently, and stirring and mixing continuously to obtain a mixed acid solution, and the mixed acid solution is added to pickle the leather;

[0012] (6) adding a tanning agent and an antibacterial agent into a drum, heating to 30° C., and rotating the drum for 3 hours for tanning, wherein the tanning agent is tannin extract, and the antibacterial agent is a mixture of modified chitosan, glycyrrhizic acid, and a nano-silver solution, wherein the concentration of the nano-silver solution is 0.3 mol / L;

[0013] (7) Take out the tanned leather, wash it with clean water and control the water, then put it into a rotating drum, add fatliquor, rotate and fatliquor for 2 hours, then take it out, wash it with clean water and dry it.

[0014] Sodium cocoyl glycinate aqueous solution is a new green environmentally friendly surfactant with a simple composition structure. It can reduce the impact on the moisture resistance of leather and effectively remove various oils in the leather. And through the double degreasing process, it can also effectively remove other impurities on the leather, which is beneficial to the subsequent tanning process of the leather.

[0015] Furthermore, in step (2), the amount of the sodium cocoyl glycinate aqueous solution added is 2.5-3% of the tare weight, the amount of acetone added is 0.2-0.3% of the tare weight, and the amount of the enzyme preparation added is 0.4-0.6% of the tare weight.

[0016] Furthermore, in step (3), the amount of sodium cocoyl glycinate aqueous solution added is 1.5-2% of the tare weight, the amount of acetone added is 0.06-0.12% of the tare weight, and the amount of enzyme preparation added is 0.2-0.3% of the tare weight.

[0017] Furthermore, in the antibacterial agent, the mass ratio of the mixed solution of modified chitosan, glycyrrhizic acid and nano-silver solution is 25-30:5-10:1.

[0018] Furthermore, the preparation method of the modified chitosan is: after stirring and dispersing chitosan in water, sodium carbonate is added and stirring is continued for 30 minutes, carboxymethyl cellulose and maleic anhydride are added, and the reaction is carried out for 4 to 5 hours to obtain the modified chitosan.

[0019] Furthermore, the mass ratio of carboxymethyl cellulose, maleic anhydride and chitosan is 2:1:7.

[0020] Furthermore, the soaking time in step (1) is 8 to 10 hours.

[0021] Furthermore, the enzyme preparation is an acid lipase preparation.

[0022] A highly effective moisture-proof and antibacterial leather is prepared according to the above preparation process.

[0023] Compared with the prior art, the beneficial effect is that the present invention adopts a double degreasing process, by adding a sodium cocoyl glycinate aqueous solution, the sodium cocoyl glycinate aqueous solution, acetone and an enzyme preparation are made to carry out an efficient degreasing process on leather, and simultaneously, the internal bacteria and fungi of the leather can be effectively inhibited, and the antibacterial function of the leather can be improved. In addition, due to the fact that in the degreasing process of the existing leather, more hydrophilic components are contained in some degreasing agents or emulsifiers, the waterproof performance of the leather can be affected, and the present invention adopts a degreasing agent containing amide groups, while reducing the hydrophilic components in the emulsifier, acetone and an enzyme preparation are also added for collaborative degreasing, and acetone can not only change the molecular conformation of the enzyme preparation, but also improve the activity of the enzyme, while improving the effect of removing grease, the influence of the emulsifier on the internal structure of the leather can also be reduced, so that the leather can maintain a good moisture-proof effect. In addition, when the process of the present invention is tanned, the composite antibacterial agent composed of modified chitosan, glycyrrhizic acid and nano silver is added, which can not only make the leather have an antibacterial effect, but also promote the tanning effect of the tanning agent on the leather. Glycyrrhizic acid has a strong antibacterial effect, while modified chitosan also has good antibacterial and bactericidal effects. Both glycyrrhizic acid and modified chitosan molecules contain carboxyl groups, which can not only improve the dispersion effect of nanosilver, but also hydrogen bond with amino groups in leather and phenolic hydroxyl groups in tanning agents, so that the antibacterial ingredients can be better integrated into the leather and combined, further enhancing the antibacterial and tanning effects of the leather. DETAILED DESCRIPTION

[0024] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example 1

[0026] Soak the raw hide in water for 8 hours, then put the soaked leather into a drum, add sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation, wherein the amount of sodium cocoyl glycinate aqueous solution added is 2.5% of the weight of the leather, the amount of acetone added is 0.2% of the weight of the leather, and the amount of enzyme preparation added is 0.4% of the weight of the leather. Heat the drum to 30°C and rotate for 0.5 hours. Add warm water at 35°C to the drum, add sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation again, wherein the amount of sodium cocoyl glycinate aqueous solution added is 1.5% of the weight of the leather, the amount of acetone added is 0.06% of the weight of the leather, and the amount of enzyme preparation added is 0.2% of the weight of the leather. Heat the drum to 36°C and rotate for 2.5 hours. Take out the leather, wash it with clean water, then dehair, liming and deash the leather, then add softener to the drum, soften the leather, and then add salt and mixed acid solution to the drum for pickling to obtain pickled leather.

[0027] Weigh carboxymethyl cellulose, maleic anhydride and chitosan in a mass ratio of 2:1:7, stir and disperse chitosan in water, add sodium carbonate and continue stirring for 30 minutes, add carboxymethyl cellulose and maleic anhydride, react for 4 to 5 hours, and obtain modified chitosan. Weigh a mixed solution of modified chitosan, glycyrrhizic acid and nano-silver solution in a mass ratio of 25:5:1, mix to obtain an antibacterial agent, add 3% tannin extract and 5% antibacterial agent by weight into a drum, heat to 30°C, rotate the drum for 3 hours for tanning, take out the tanned leather, wash it with clean water and control the water, then put it into a drum, add a fatting agent, rotate and fatten for 2 hours, then take it out and wash it with clean water and dry it to obtain moisture-proof and antibacterial leather.

[0028] Example 2

[0029] Soak the raw hide in water for 9 hours, then put the soaked leather into a drum, add sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation, wherein the amount of sodium cocoyl glycinate aqueous solution added is 2.7% of the weight of the leather, the amount of acetone added is 0.25% of the weight of the leather, and the amount of enzyme preparation added is 0.5% of the weight of the leather, and the drum is heated to 33°C and rotated for 0.5 hours. Add warm water at 35°C to the drum, add sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation again, wherein the amount of sodium cocoyl glycinate aqueous solution added is 1.8% of the weight of the leather, the amount of acetone added is 0.1% of the weight of the leather, and the amount of enzyme preparation added is 0.25% of the weight of the leather, and the drum is heated to 36°C and rotated for 2.5 hours. Take out the leather, wash it with clean water, then dehair, liming, and deashing the leather, then add softener to the drum, soften the leather, and then add salt and mixed acid solution to the drum for pickling to obtain pickled leather.

[0030] Weigh carboxymethyl cellulose, maleic anhydride and chitosan in a mass ratio of 2:1:7, stir and disperse chitosan in water, add sodium carbonate and continue stirring for 30 minutes, add carboxymethyl cellulose and maleic anhydride, react for 4 to 5 hours, and obtain modified chitosan. Weigh a mixed solution of modified chitosan, glycyrrhizic acid and nano-silver solution in a mass ratio of 25:5:1, mix to obtain an antibacterial agent, add 3% tannin extract and 5% antibacterial agent by weight into a drum, heat to 30°C, rotate the drum for 3 hours for tanning, take out the tanned leather, wash it with clean water and control the water, then put it into a drum, add a fatting agent, rotate and fatten for 2 hours, then take it out and wash it with clean water and dry it to obtain moisture-proof and antibacterial leather.

[0031] Example 3

[0032] Soak the raw hide in water for 10 hours, then put the soaked leather into a drum, add sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation, wherein the amount of sodium cocoyl glycinate aqueous solution added is 3% of the weight of the leather, the amount of acetone added is 0.3% of the weight of the leather, and the amount of enzyme preparation added is 0.6% of the weight of the leather, and the drum is heated to 35°C and rotated for 0.5 hours. Add 35°C warm water to the drum, add sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation again, wherein the amount of sodium cocoyl glycinate aqueous solution added is 2% of the weight of the leather, the amount of acetone added is 0.12% of the weight of the leather, and the amount of enzyme preparation added is 0.3% of the weight of the leather, and the drum is heated to 38°C and rotated for 2.5 hours. Take out the leather, wash it with clean water, then dehair, liming and deashing the leather, then add softener to the drum, soften the leather, and then add salt and mixed acid solution to the drum for pickling to obtain pickled leather.

[0033] Weigh carboxymethyl cellulose, maleic anhydride and chitosan in a mass ratio of 2:1:7, stir and disperse chitosan in water, add sodium carbonate and continue stirring for 30 minutes, add carboxymethyl cellulose and maleic anhydride, react for 4 to 5 hours, and obtain modified chitosan. Weigh a mixed solution of modified chitosan, glycyrrhizic acid and nano-silver solution in a mass ratio of 25:5:1, mix to obtain an antibacterial agent, add 3% tannin extract and 5% antibacterial agent by weight into a drum, heat to 30°C, rotate the drum for 3 hours for tanning, take out the tanned leather, wash it with clean water and control the water, then put it into a drum, add a fatting agent, rotate and fatten for 2 hours, then take it out and wash it with clean water and dry it to obtain moisture-proof and antibacterial leather.

[0034] Example 4

[0035] Soak the raw hide in water for 9 hours, then put the soaked leather into a drum, add sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation, wherein the amount of sodium cocoyl glycinate aqueous solution added is 2.5% of the weight of the leather, the amount of acetone added is 0.2% of the weight of the leather, and the amount of enzyme preparation added is 0.4% of the weight of the leather. Heat the drum to 33°C and rotate for 0.5 hours. Add warm water at 35°C to the drum, add sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation again, wherein the amount of sodium cocoyl glycinate aqueous solution added is 1.5% of the weight of the leather, the amount of acetone added is 0.06% of the weight of the leather, and the amount of enzyme preparation added is 0.2% of the weight of the leather. Heat the drum to 36°C and rotate for 2.5 hours. Take out the leather, wash it with clean water, then dehair, liming and deash the leather, then add softener to the drum, soften the leather, and then add salt and mixed acid solution to the drum for pickling to obtain pickled leather.

[0036] Weigh carboxymethyl cellulose, maleic anhydride and chitosan in a mass ratio of 2:1:7, stir and disperse chitosan in water, add sodium carbonate and continue stirring for 30 minutes, add carboxymethyl cellulose and maleic anhydride, react for 4 to 5 hours, and obtain modified chitosan. Weigh a mixed solution of modified chitosan, glycyrrhizic acid and nano-silver solution in a mass ratio of 27:7:1, mix to obtain an antibacterial agent, add 3% tannin extract and 5% antibacterial agent by weight into a drum, heat to 30°C, rotate the drum for 3 hours for tanning, take out the tanned leather, wash it with clean water and control the water, then put it into a drum, add a fatting agent, rotate and fatten for 2 hours, then take it out and wash it with clean water and dry it to obtain moisture-proof and antibacterial leather.

[0037] Example 5

[0038] Soak the raw hide in water for 9 hours, then put the soaked leather into a drum, add sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation, wherein the amount of sodium cocoyl glycinate aqueous solution added is 2.5% of the weight of the leather, the amount of acetone added is 0.2% of the weight of the leather, and the amount of enzyme preparation added is 0.4% of the weight of the leather. Heat the drum to 33°C and rotate for 0.5 hours. Add warm water at 35°C to the drum, add sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation again, wherein the amount of sodium cocoyl glycinate aqueous solution added is 1.5% of the weight of the leather, the amount of acetone added is 0.06% of the weight of the leather, and the amount of enzyme preparation added is 0.2% of the weight of the leather. Heat the drum to 36°C and rotate for 2.5 hours. Take out the leather, wash it with clean water, then dehair, liming and deash the leather, then add softener to the drum, soften the leather, and then add salt and mixed acid solution to the drum for pickling to obtain pickled leather.

[0039] Weigh carboxymethyl cellulose, maleic anhydride and chitosan in a mass ratio of 2:1:7, stir and disperse chitosan in water, add sodium carbonate and continue stirring for 30 minutes, add carboxymethyl cellulose and maleic anhydride, react for 4 to 5 hours, and obtain modified chitosan. Weigh a mixed solution of modified chitosan, glycyrrhizic acid and nano-silver solution in a mass ratio of 30:10:1, mix to obtain an antibacterial agent, add 3% tannin extract and 5% antibacterial agent by weight into a drum, heat to 30°C, rotate the drum for 3 hours for tanning, take out the tanned leather, wash it with clean water and control the water, then put it into a drum, add a fatting agent, rotate and fatten for 2 hours, then take it out and wash it with clean water and dry it to obtain moisture-proof and antibacterial leather.

[0040] Comparative Example 1

[0041] The raw hide is soaked in water for 9 hours, then the soaked leather is put into a drum, an enzyme treatment solution is added, and the drum is rotated for 3 hours before being taken out to obtain degreased leather; the leather is taken out and washed with clean water, then the leather is dehaired, limed, and delimed, and a softener is added to the drum to soften the leather, and then salt and a mixed acid solution are added to the drum for pickling to obtain pickled leather. A tanning agent of 3% of the weight of the leather is added to the drum, heated to 30°C, and the drum is rotated for 3 hours for tanning. The tanned leather is taken out, washed with clean water and the water is controlled, and then put into the drum again, a fatting agent is added, and fatting is rotated for 2 hours, and then taken out and washed with clean water and dried to obtain leather.

[0042] Comparative Example 2

[0043] Soak the raw hide in water for 9 hours, then put the soaked leather into a drum, add sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation, wherein the amount of sodium cocoyl glycinate aqueous solution added is 2.5% of the weight of the leather, the amount of acetone added is 0.2% of the weight of the leather, and the amount of enzyme preparation added is 0.4% of the weight of the leather. Heat the drum to 33°C and rotate for 0.5 hours. Add warm water at 35°C to the drum, add sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation again, wherein the amount of sodium cocoyl glycinate aqueous solution added is 1.5% of the weight of the leather, the amount of acetone added is 0.06% of the weight of the leather, and the amount of enzyme preparation added is 0.2% of the weight of the leather. Heat the drum to 36°C and rotate for 2.5 hours. Take out the leather, wash it with clean water, then dehair, liming and deash the leather, then add softener to the drum, soften the leather, and then add salt and mixed acid solution to the drum for pickling to obtain pickled leather. Add 3% tanning agent by weight into the drum, heat to 30°C, and rotate the drum for 3 hours for tanning. Take out the tanned leather, wash it with clean water and control the water, then put it into the drum again, add fatliquor, rotate and fatliquor for 2 hours, then take it out, wash it with clean water and dry it to obtain leather.

[0044] Comparative Example 3

[0045] The raw hide is soaked in water for 9 hours, then the soaked leather is put into a drum, an enzyme treatment solution is added, and the drum is rotated for 3 hours before being taken out to obtain degreased leather; the leather is taken out and washed with clean water, then the leather is dehaired, limed, and delimed, and a softener is added to the drum to soften the leather, and then salt and mixed acid are added to the drum for pickling to obtain pickled leather. The mass ratio of carboxymethyl cellulose, maleic anhydride and chitosan is weighed to be 2:1:7, chitosan is stirred and dispersed in water, sodium carbonate is added, and stirring is continued for 30 minutes, carboxymethyl cellulose and maleic anhydride are added, and the reaction is carried out for 4 to 5 hours to obtain modified chitosan. Weigh a mixed solution of modified chitosan, glycyrrhizic acid and nanosilver solution in a mass ratio of 30:10:1, mix to obtain an antibacterial agent, add tannin extract (3% by weight) and antibacterial agent (5% by weight) into a rotary drum, heat to 30°C, rotate the drum for 3 hours for tanning, take out the tanned leather, wash it with clean water and control the water, then put it into a rotary drum, add a fatting agent, rotate and fatten for 2 hours, then take it out, wash it with clean water and dry it to obtain leather.

[0046] Moisture-proof effect test:

[0047] At room temperature, the leathers prepared in Examples 1-5 and Comparative Examples 1-3 were immersed in clean water, taken out, squeezed to a water-free state and weighed, and then placed on a balance in a ventilated place at room temperature, and their weights were recorded every 5 minutes until their weights no longer changed. The total time spent was recorded as shown in Table 1:

[0048] Table 1 Moisture resistance test results

[0049]

[0050] From the test results in Table 1, it can be seen that the leather prepared by degreasing with sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation requires less time to dry, which is conducive to quick drying of the leather and the water inside, thereby greatly improving the moisture-proof effect of the leather.

[0051] Antibacterial effect test:

[0052] Examples 1-5 and Comparative Examples 1-3 were tested according to GB / T 20944.3-2008 "Evaluation of Antibacterial Properties of Textiles", and the test results are recorded in Table 2:

[0053] Table 2 Antibacterial test results

[0054]

[0055] From the results in Table 2, it can be analyzed that as the amount of sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation increases, the leather obtained has good antibacterial properties. At the same time, under the coordinated reaction of antibacterial agents, the antibacterial properties of the leather can be further improved.

[0056] The above embodiments are not intended to limit the scope of the present invention. Any appropriate changes or modifications made by a person skilled in the art should be deemed to be within the patent scope of the present invention.

[0057] The above embodiments do not limit the product form and style of the present invention. Any appropriate changes or modifications made by ordinary technicians in the relevant technical field should be deemed to be within the patent scope of the present invention.

Claims

1. A process for preparing highly effective moisture-proof and antibacterial leather, characterized in that: The following steps are involved: (1) Soaking the hide in water; (2) putting the soaked leather into a drum, adding the sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation, heating the drum to 30-35° C., and rotating for 0.5 hours; (3) adding warm water at 35° C. to the drum, adding the sodium cocoyl glycinate aqueous solution, acetone and enzyme preparation again, heating the drum to 35-38° C., and rotating for 2.5 hours; (4) taking out the leather, washing it with clean water, then dehairing, liming and deashing the leather, and then adding a softener into the drum to soften the leather; (5) adding mixed acid solution to pickle the leather; (6) adding a tanning agent and an antibacterial agent into a drum, and rotating the drum for 3 hours for tanning, wherein the tanning agent is tannin extract, and the antibacterial agent is a mixture of modified chitosan, glycyrrhizic acid and nano-silver solution; (7) Take out the tanned leather, wash it with clean water and control the water, then put it into a rotating drum, add fatliquor, rotate and fatliquor for 2 hours, then take it out, wash it with clean water and dry it.

2. The process for preparing a highly effective moisture-proof and antibacterial leather according to claim 1, characterized in that: In step (2), the amount of sodium cocoyl glycinate aqueous solution added is 2.5-3% of the tare weight, the amount of acetone added is 0.2-0.3% of the tare weight, and the amount of enzyme preparation added is 0.4-0.6% of the tare weight.

3. The process for preparing a highly effective moisture-proof and antibacterial leather according to claim 1, characterized in that: In step (3), the amount of sodium cocoyl glycinate aqueous solution added is 1.5-2% of the tare weight, the amount of acetone added is 0.06-0.12% of the tare weight, and the amount of enzyme preparation added is 0.2-0.3% of the tare weight.

4. The process for preparing a highly effective moisture-proof and antibacterial leather according to claim 1, characterized in that: In the antibacterial agent, the mass ratio of the mixed liquid of modified chitosan, glycyrrhizic acid and nano silver solution is 25-30:5-10:

1.

5. The process for preparing a highly effective moisture-proof and antibacterial leather according to claim 4, characterized in that: The preparation method of the modified chitosan is as follows: after chitosan is dispersed in water by stirring, sodium carbonate is added and stirring is continued for 30 minutes, carboxymethyl cellulose and maleic anhydride are added, and the reaction is continued for 4 minutes. ～ 5 hours to obtain modified chitosan.

6. A process for preparing a highly effective moisture-proof and antibacterial leather as claimed in claim 5, characterized in that: The mass ratio of carboxymethyl cellulose, maleic anhydride and chitosan is 2:1:

7.

7. The process for preparing a highly effective moisture-proof and antibacterial leather according to claim 1, characterized in that: The soaking time in step (1) is 8 ～ 10 hours.

8. The process for preparing a highly effective moisture-proof and antibacterial leather according to claim 1, characterized in that: The enzyme preparation is an acid lipase preparation.

9. A highly effective moisture-proof and antibacterial leather, characterized in that: Prepared according to the preparation process described in any one of claims 1-8.

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