Durable antibacterial environment-friendly leather and preparation method thereof

Abstract

The invention discloses durable antibacterial environment-friendly leather and a preparation method, the preparation method comprises the steps of soaking, degreasing, pickling, tanning, fat liquoring, drying and the like, an antibacterial solution is added in the tanning and fat liquoring process of the leather, and the antibacterial solution is a mixed solution of modified limonene, eucalyptus oil and a nano-silver solution. The environment-friendly tanning agent is adopted, limonene and eucalyptus oil are natural and environment-friendly extracts and both have a good antibacterial effect, an antibacterial liquid can form an antibacterial layer on the surface of leather, and the antibacterial capacity of the leather is improved. The modified limonene can be combined with leather fibers, pore structures can be further expanded, nano-silver particles in the eucalyptus oil and the nano-silver solution can better permeate into the leather, and the nano-silver particles have good antibacterial performance, so that the leather has lasting antibacterial ability.

Description

Technical Field

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

[0002] Leather has an absolute advantage in the market due to its elegant color, natural texture, delicate feel and comfortable wearing. It has long been an important raw material in the fields of high-end shoes, bags, leisure products, furniture decoration, etc. Leather contains nutrients such as protein, oil, starch, etc., which provide a favorable place for the growth of microorganisms. Therefore, leather is easily eroded by microorganisms (fungi), causing the product to mold and deteriorate easily. The mildew of leather and its products seriously affects their use value. Especially for footwear products, it is easy to cause sweat or dirt residue by simply wiping and drying. Under suitable temperature and humidity conditions, it is easy to breed a large number of harmful microorganisms such as bacteria and viruses, which seriously affects the quality of leather products and also seriously threatens human health.

[0003] There is almost no special antibacterial process in the conventional leather making process. The purpose of inhibiting the mildew of leather is mainly achieved by adding mildew inhibitors during the leather making process. However, mildew inhibitors have the problems of easy odor, high cost, poor permeability, high toxicity, and environmental pollution. Therefore, in order to give leather and leather products long-lasting and efficient antibacterial properties, it is necessary to start from the leather making process.

[0004] In view of this, the applicant conducted in-depth research on the above issues, which led to the present case. Summary of the invention

[0005] The main purpose of the present invention is to provide a durable antibacterial and environmentally friendly leather and a preparation method, which effectively solves the above technical problems and makes the leather have durable and efficient antibacterial ability while being more environmentally friendly.

[0006] In order to achieve the above object, the solution of the present invention is:

[0007] A method for preparing durable antibacterial and environmentally friendly leather comprises the following steps:

[0008] (1) completely immersing the raw hide in water to obtain water-immersed leather;

[0009] (2) placing the soaked leather in a drum, adding an enzyme treatment solution, and rotating the drum for 3 hours before taking it out to obtain degreased leather;

[0010] (3) cleaning the degreased leather, dehairing, liming and deliming the cleaned degreased leather, adding a softener into a rotary drum, softening the leather, and rotating the rotary drum for washing;

[0011] (4) After adding water and salt into the drum, the softened leather is added into the drum, and then the diluted mixed acid solution is added for pickling to obtain pickled leather;

[0012] (5) adding a tanning agent into a rotary drum and rotating the drum for tanning, wherein the tanning agent is a mixture of tannin extract and an antibacterial liquid, and the antibacterial liquid is a mixture of modified limonene, eucalyptus oil and a nano-silver solution;

[0013] (6) The tanned leather is taken out and washed with water to control the water, and then the leather is added to a fatliquor containing an antibacterial liquid, and the fatliquor is rotated for 3 hours. Finally, the leather is taken out, rinsed and dried to obtain antibacterial and environmentally friendly leather.

[0014] Furthermore, the mass ratio of modified limonene, eucalyptus oil and nanosilver solution in the antibacterial liquid is 20-25:13-18:1;

[0015] Furthermore, the modified limonene is a copolymer of limonene and maleic anhydride, the reaction molar ratio of limonene to maleic anhydride is 5 to 6:1, the initiator is di-tert-butyl peroxide, and the copolymerization temperature is 110 to 120°C;

[0016] Furthermore, in step (5), the content of the antibacterial liquid in the tanning agent is 13wt% to 19wt%.

[0017] Furthermore, in step (6), the content of the antibacterial liquid in the fatliquor is 21wt% to 26wt%.

[0018] Furthermore, the soaking time in step (1) is 5 hours.

[0019] Furthermore, in step (5), the tanning time is 7 hours and the tanning temperature is 30-35°C.

[0020] Furthermore, the mixed acid solution is prepared by adding formic acid into a glass container containing an appropriate amount of water and stirring continuously; and then slowly adding concentrated sulfuric acid intermittently and stirring continuously to mix well.

[0021] Furthermore, the mass volume ratio of formic acid, water and concentrated sulfuric acid in the mixed acid solution is 10ml:200ml:10ml.

[0022] The present invention also provides antibacterial and environmentally friendly leather produced by the preparation method.

[0023] Compared with the prior art, the beneficial effect is that, in the tanning process of the present invention, an environmentally friendly tanning agent is adopted, wherein limonene and eucalyptus oil are natural and environmentally friendly extracts, both have good antibacterial effects, and the antibacterial liquid can form an antibacterial layer on the leather surface, thereby improving the antibacterial ability of the leather. Simultaneously, after modification, limonene contains a carboxyl group in its molecule, which can be combined with the tanning agent and hydroxyl groups in the leather fiber, thereby further expanding the pore structure, thereby making the nano-silver particles in the nano-silver solution better penetrate into the inside of the leather, and the nano-silver particles have good antibacterial properties, thereby further improving the antibacterial ability of the leather inside. In addition, a molecule of the modified limonene contains a plurality of carboxyl groups, and nano-silver and eucalyptus oil can be covalently bonded to the leather fiber, thereby playing the role of a bridge bond, thereby achieving a lasting antibacterial effect. 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 making creative work are within the scope of protection of the present invention.

[0025] Example 1

[0026] Mix formic acid, water and concentrated sulfuric acid in a volume ratio of 10ml:200ml:10ml. Measure formic acid and add it into a glass container filled with an appropriate amount of water. After stirring evenly, slowly add concentrated sulfuric acid intermittently and stir continuously to obtain a mixed acid solution.

[0027] The raw hide is completely immersed in water for 5 hours to obtain soaked leather; the soaked leather is placed inside a drum, and an enzyme treatment solution is added, and the drum is rotated for 3 hours before being taken out to obtain degreased leather; the degreased leather is washed, and the washed degreased leather is dehaired, limed and delimed, and then a softener is added to the drum to soften the leather and wash the leather. Then salt and a mixed acid solution are added to the drum for pickling to obtain pickled leather; sodium bicarbonate is added to adjust the pH to 4; a tanning agent is added to the drum and the drum is rotated for tanning for 7 hours, and the tanning temperature is 30°C, the tanning agent is a mixture of tannin extract and antibacterial solution, and the antibacterial solution is a mixture of modified limonene, eucalyptus oil and nanosilver solution. The modified limonene is a copolymer of limonene and maleic anhydride, the reaction molar ratio of limonene to maleic anhydride is 5-6:1, the initiator is di-tert-butyl peroxide, and the copolymerization temperature is 110-120°C; wherein the mass ratio of modified limonene, eucalyptus oil and nano-silver solution in the antibacterial liquid is 20:13:1, and the content of the antibacterial liquid in the tanning agent is 13wt%. The tanned leather is taken out and dried, and then the leather is added to a drum containing the antibacterial liquid and fatliquor and rotated for 3 hours, the content of the antibacterial liquid in the fatliquor is 21wt%, and finally the leather is taken out, rinsed and dried to obtain antibacterial and environmentally friendly leather.

[0028] Example 2

[0029] Mix formic acid, water and concentrated sulfuric acid in a mass volume ratio of 10ml:200ml:10ml. Measure formic acid and add it into a glass container filled with an appropriate amount of water. After stirring evenly, slowly add concentrated sulfuric acid intermittently and continue stirring to obtain a mixed acid solution.

[0030] The raw hide is completely immersed in water for 5 hours to obtain soaked leather; the soaked leather is placed inside a drum, and an enzyme treatment solution is added, and the drum is rotated for 3 hours before being taken out to obtain degreased leather; the degreased leather is washed, and the washed degreased leather is dehaired, limed and delimed, and then a softener is added to the drum to soften the leather and wash the leather. Then salt and a mixed acid solution are added to the drum for pickling to obtain pickled leather; sodium bicarbonate is added to adjust the pH to 4; a tanning agent is added to the drum and the drum is rotated for tanning for 7 hours, and the tanning temperature is 30°C, the tanning agent is a mixture of tannin extract and antibacterial solution, and the antibacterial solution is a mixture of modified limonene, eucalyptus oil and nanosilver solution. The modified limonene is a copolymer of limonene and maleic anhydride, the reaction molar ratio of limonene to maleic anhydride is 5-6:1, the initiator is di-tert-butyl peroxide, and the copolymerization temperature is 110-120°C; the mass ratio of modified limonene, eucalyptus oil and nano-silver solution in the antibacterial liquid is 20:13:1, and the content of the antibacterial liquid in the tanning agent is 16wt%. The tanned leather is taken out and dried, and then the leather is added to a drum containing the antibacterial liquid and fatliquor and rotated for 3 hours, the content of the antibacterial liquid in the fatliquor is 23wt%, and finally the leather is taken out, rinsed and dried to obtain antibacterial and environmentally friendly leather.

[0031] Example 3

[0032] Mix formic acid, water and concentrated sulfuric acid in a volume ratio of 10ml:200ml:10ml. Measure formic acid and add it into a glass container filled with an appropriate amount of water. After stirring evenly, slowly add concentrated sulfuric acid intermittently and stir continuously to obtain a mixed acid solution.

[0033] The raw hide is completely immersed in water for 5 hours to obtain soaked leather; the soaked leather is placed inside a drum, and an enzyme treatment solution is added, and the drum is rotated for 3 hours before being taken out to obtain degreased leather; the degreased leather is washed, and the washed degreased leather is dehaired, limed and delimed, and then a softener is added to the drum to soften the leather and wash the leather. Then salt and a mixed acid solution are added to the drum for pickling to obtain pickled leather; sodium bicarbonate is added to adjust the pH to 4; a tanning agent is added to the drum and the drum is rotated for tanning for 7 hours, and the tanning temperature is 30°C, the tanning agent is a mixture of tannin extract and antibacterial solution, and the antibacterial solution is a mixture of modified limonene, eucalyptus oil and nanosilver solution. The modified limonene is a copolymer of limonene and maleic anhydride, the reaction molar ratio of limonene to maleic anhydride is 5-6:1, the initiator is di-tert-butyl peroxide, and the copolymerization temperature is 110-120°C; the mass ratio of modified limonene, eucalyptus oil and nano-silver solution in the antibacterial liquid is 20:13:1, and the content of the antibacterial liquid in the tanning agent is 19wt%. The tanned leather is taken out and dried, and then the leather is added to a drum containing the antibacterial liquid and fatliquor and rotated for 3 hours, the content of the antibacterial liquid in the fatliquor is 26wt%, and finally the leather is taken out, rinsed and dried to obtain antibacterial and environmentally friendly leather.

[0034] Example 4

[0035] Mix formic acid, water and concentrated sulfuric acid in a volume ratio of 10ml:200ml:10ml. Measure formic acid and add it into a glass container filled with an appropriate amount of water. After stirring evenly, slowly add concentrated sulfuric acid intermittently and stir continuously to obtain a mixed acid solution.

[0036] The raw hide is completely immersed in water for 5 hours to obtain soaked leather; the soaked leather is placed inside a drum, and an enzyme treatment solution is added, and the drum is rotated for 3 hours before being taken out to obtain degreased leather; the degreased leather is washed, and the washed degreased leather is dehaired, limed and delimed, and then a softener is added to the drum to soften the leather and wash the leather. Then salt and a mixed acid solution are added to the drum for pickling to obtain pickled leather; sodium bicarbonate is added to adjust the pH to 4; a tanning agent is added to the drum and the drum is rotated for tanning for 7 hours, and the tanning temperature is 30°C, the tanning agent is a mixture of tannin extract and antibacterial solution, and the antibacterial solution is a mixture of modified limonene, eucalyptus oil and nanosilver solution. The modified limonene is a copolymer of limonene and maleic anhydride, the reaction molar ratio of limonene to maleic anhydride is 5-6:1, the initiator is di-tert-butyl peroxide, and the copolymerization temperature is 110-120°C; wherein the mass ratio of modified limonene, eucalyptus oil and nano-silver solution in the antibacterial liquid is 23:16:1, and the content of the antibacterial liquid in the tanning agent is 13wt%. The tanned leather is taken out and dried, and then the leather is added to a drum containing the antibacterial liquid and a fatliquor and rotated for 3 hours, the content of the antibacterial liquid in the fatliquor is 21wt%, and finally the leather is taken out, rinsed and dried to obtain antibacterial and environmentally friendly leather.

[0037] Example 5

[0038] Mix formic acid, water and concentrated sulfuric acid in a volume ratio of 10ml:200ml:10ml. Measure formic acid and add it into a glass container filled with an appropriate amount of water. After stirring evenly, slowly add concentrated sulfuric acid intermittently and stir continuously to obtain a mixed acid solution.

[0039] The raw hide is completely immersed in water for 5 hours to obtain soaked leather; the soaked leather is placed inside a drum, and an enzyme treatment solution is added, and the drum is rotated for 3 hours before being taken out to obtain degreased leather; the degreased leather is washed, and the washed degreased leather is dehaired, limed and delimed, and then a softener is added to the drum to soften the leather and wash the leather. Then salt and a mixed acid solution are added to the drum for pickling to obtain pickled leather; sodium bicarbonate is added to adjust the pH to 4; a tanning agent is added to the drum and the drum is rotated for tanning for 7 hours, and the tanning temperature is 30°C, the tanning agent is a mixture of tannin extract and antibacterial solution, and the antibacterial solution is a mixture of modified limonene, eucalyptus oil and nanosilver solution. The modified limonene is a copolymer of limonene and maleic anhydride, the reaction molar ratio of limonene to maleic anhydride is 5-6:1, the initiator is di-tert-butyl peroxide, and the copolymerization temperature is 110-120°C; wherein the mass ratio of modified limonene, eucalyptus oil and nano-silver solution in the antibacterial liquid is 25:18:1, and the content of the antibacterial liquid in the tanning agent is 13wt%. The tanned leather is taken out and dried, and then the leather is added to a drum containing the antibacterial liquid and a fatliquor and rotated for 3 hours, the content of the antibacterial liquid in the fatliquor is 21wt%, and finally the leather is taken out, rinsed and dried to obtain antibacterial and environmentally friendly leather.

[0040] Comparative Example 1

[0041] Mix formic acid, water and concentrated sulfuric acid in a volume ratio of 10ml:200ml:10ml. Measure formic acid and add it into a glass container filled with an appropriate amount of water. After stirring evenly, slowly add concentrated sulfuric acid intermittently and stir continuously to obtain a mixed acid solution.

[0042] The raw hide is completely immersed in water for 5 hours to obtain soaked leather; the soaked leather is placed inside a rotary drum, and an enzyme treatment solution is added, and the drum is rotated for 3 hours before being taken out to obtain degreased leather; the degreased leather is washed, and the washed degreased leather is dehaired, limed and delimed, and then a softener is added to the drum to soften the leather and wash the leather. Then salt and a mixed acid solution are added to the drum for pickling to obtain pickled leather; sodium bicarbonate is added to adjust the pH to 4, and then the drum is rotated for washing; a tanning agent is added to the drum and the drum is rotated for tanning for 7 hours, and the tanning temperature is 30°C, the tanning agent is a mixture of tannin extract and antibacterial solution, and the antibacterial solution is a mixture of modified limonene, eucalyptus oil and nanosilver solution. The modified limonene is a copolymer of limonene and maleic anhydride, the reaction molar ratio of limonene to maleic anhydride is 5-6:1, the initiator is di-tert-butyl peroxide, and the copolymerization temperature is 110-120°C; the mass ratio of the modified limonene, eucalyptus oil and nano-silver solution in the antibacterial liquid is 20:13:1, and the content of the antibacterial liquid in the tanning agent is 13wt%. The tanned leather is taken out, washed and dried to obtain leather.

[0043] Comparative Example 2

[0044] Mix formic acid, water and concentrated sulfuric acid in a volume ratio of 10ml:200ml:10ml. Measure formic acid and add it into a glass container filled with an appropriate amount of water. After stirring evenly, slowly add concentrated sulfuric acid intermittently and stir continuously to obtain a mixed acid solution.

[0045] The raw hide is completely immersed in water for 5 hours to obtain water-soaked leather; the water-soaked leather is placed inside a rotary drum and an enzyme treatment solution is added. After the cleaned degreased leather is dehaired, limed and delimed, a softener is added to the rotary drum to soften the leather and wash the leather. Then salt and mixed acid solution are added to the rotary drum for pickling to obtain pickled leather; sodium bicarbonate is added to adjust the pH to 4, and then the rotary drum is rotated for water washing; chrome tanning agent is added to the rotary drum and the rotary drum is rotated for tanning for 7 hours, and the tanning temperature is 30°C. The tanned leather is taken out, washed and dried to obtain leather.

[0046] Examples 1-5 and Comparative Examples 1-2 were tested according to GB / T 20944.3-2008 “Evaluation of antibacterial properties of textiles”, and the test results are recorded in Table 1.

[0047] Table 1 Antibacterial test results

[0048]

[0049]

[0050] Analysis of Examples 1-3 shows that as the mass ratio of modified limonene and eucalyptus oil gradually increases, the antibacterial effect of the prepared leather becomes better. Analysis of Examples 1, 4 and 5 shows that when the content of the same ratio of antibacterial liquid in the tanning agent and fatliquor is higher, the antibacterial performance of the prepared leather is higher. Analysis of Example 1, Comparative Example 1 and Comparative Example 2 shows that the antibacterial performance of the leather after antibacterial liquid tanning and fatliquoring is significantly improved.

[0051] 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.

Claims

1. A method for preparing durable antibacterial and environmentally friendly leather, characterized in that: The following steps are involved: (1) completely immersing the raw hide in water to obtain water-immersed leather; (2) placing the soaked leather in a drum, adding an enzyme treatment solution, and rotating the drum for 3 hours before taking it out to obtain degreased leather; (3) cleaning the degreased leather, dehairing, liming and deliming the cleaned degreased leather, adding a softener into a rotary drum, softening the leather, and rotating the rotary drum for washing; (4) After adding water and salt into the drum, the softened leather is added into the drum, and then the diluted mixed acid solution is added for pickling to obtain pickled leather; (5) adding a tanning agent into a rotary drum and rotating the drum for tanning, wherein the tanning agent is a mixture of tannin extract and an antibacterial liquid, and the antibacterial liquid is a mixture of modified limonene, eucalyptus oil and a nano-silver solution; (6) The tanned leather is taken out and washed with water to control the water, and then the leather is added to a fatliquor containing an antibacterial liquid, and the fatliquor is rotated for 3 hours. Finally, the leather is taken out, rinsed and dried to obtain antibacterial and environmentally friendly leather.

2. The method for preparing a durable antibacterial and environmentally friendly leather according to claim 1, characterized in that: The mass ratio of modified limonene, eucalyptus oil and nano silver solution in the antibacterial liquid is 20-25:13-18:

1.

3. The method for preparing a durable antibacterial environmentally friendly leather according to claim 1, characterized in that: The modified limonene is a copolymer of limonene and maleic anhydride, the reaction molar ratio of limonene to maleic anhydride is 5-6:1, the initiator is di-tert-butyl peroxide, and the copolymerization temperature is 110-120°C.

4. The method for preparing a durable antibacterial and environmentally friendly leather according to claim 1, characterized in that: In step (5), the content of the antibacterial liquid in the tanning agent is 13wt% to 19wt%.

5. The method for preparing a durable antibacterial and environmentally friendly leather according to claim 1, characterized in that: In step (6), the content of the antibacterial liquid in the fatliquor is 21wt% to 26wt%.

6. The method for preparing a durable antibacterial and environmentally friendly leather according to claim 1, characterized in that: The soaking time in step (1) is 5 hours.

7. The method for preparing a durable antibacterial and environmentally friendly leather according to claim 1, characterized in that: In step (5), the tanning time is 7 hours and the tanning temperature is 30-35°C.

8. The method for preparing a durable antibacterial and environmentally friendly leather according to claim 1, characterized in that: The preparation method of the mixed acid solution is as follows: adding formic acid into a glass container containing an appropriate amount of water and stirring continuously; and then slowly adding concentrated sulfuric acid intermittently and stirring continuously to mix well.

9. The method for preparing a durable antibacterial and environmentally friendly leather according to claim 8, characterized in that: The mass volume ratio of formic acid, water and concentrated sulfuric acid in the mixed acid solution is 10ml:200ml:10ml.

10. A leather made by the preparation method according to claims 1-9, characterized in that: The above-mentioned preparation method is adopted to prepare the product.

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