CN112708707A - Manufacturing method of antibacterial, mildew-proof and skin-friendly leather - Google Patents

Abstract

The invention discloses a manufacturing method of antibacterial mildew-proof skin-friendly leather, which is characterized in that oxidized chitosan biquaternary ammonium salt is used for independent post-treatment in pretanning and/or wet dyeing and finishing of pelts, and the activity of aldehyde group in the oxidized chitosan biquaternary ammonium salt is utilized to graft the chitosan biquaternary ammonium salt on the leather, so that the antibacterial mildew-proof skin-friendly leather is prepared. Because the grafted chitosan biquaternary ammonium salt is a derivative taking chitosan as a framework, the grafted chitosan biquaternary ammonium salt has good skin-friendly property; the biquaternary ammonium salt has more quaternary ammonium groups, so that the finished leather has good antibacterial and mildewproof performance and good water washing resistance. The method can be used for producing and processing various leathers of pigs, cattle, sheep, etc.

Description

Manufacturing method of antibacterial, mildew-proof and skin-friendly leather

Technical Field

The invention relates to a manufacturing method of antibacterial, mildew-proof and skin-friendly leather, belonging to the leather industry.

Background

The main component of the leather is collagen fiber, the contained nitrogen, carbon, oxygen, hydrogen, mineral substances and the like are all necessary nutrient components for the growth and the propagation of mould, and the fungi can convert the nutrient components in the leather into water-soluble substances to be absorbed into cells, so that the bacteria are easy to parasitize in the leather. In the process of leather storage and transportation (such as blue leather storage and transportation, semi-finished product storage and transportation, leather product storage and transportation and the like), various moulds are contacted due to the change of the environment, if the leather is not treated in time, color spots and grain surface damage can be formed on the leather, and the moulds on the surface can also develop into the leather, so that the wear resistance, the strength and the elasticity of the leather are influenced. The leather grade is reduced if the weight is light, and the economic utilization value of the leather is lost if the weight is heavy. During the use process of the leather product, various bacteria are inevitably contacted, part of the bacteria have pathogenicity and possibly stay in the leather, and when the skin is damaged (such as the damage caused by mechanical trauma, diabetes and the like), the bacteria can be mixed in by mistake and harm the human health. Although the leather is added with the mildew preventive, the bactericide and the like to play a role in resisting and preventing bacteria to a certain extent, the products on the market are often expensive, poor in permeability, large in skin irritation (such as skin allergy), high in toxicity, poor in environmental protection and the like. The conventional antibacterial and mildewproof material cannot be organically combined with leather, so that the defects of easy migration, poor antibacterial and mildewproof durability and the like are caused. After the upper leather is made into leather shoes, the leather shoes are usually in direct contact with sweat or skin of a human body in the using process, and common antibacterial agents easily cause foot itching and allergy and cause foot diseases. Some patients with diabetes and beriberi will be deepened and harmful to health. The leather has wide and important application in the fields of daily necessities, clothes, shoemaking, public facilities and the like, so that the use of the antibacterial leather can effectively reduce cross infection and disease transmission and is beneficial to the health of all human beings.

The common antibacterial leather manufacturing method generally adopts a method of adding inorganic or organic antibacterial agents. Previous manufacturing methods tend to suffer from one or more of the following disadvantages: (1) it is expensive. Silver ion antibacterial agents are excellent in effect, but silver ions are expensive and difficult to use on a large scale in leather products. (2) Has safety risk and can not give consideration to the unification of antibiosis and skin-friendly. The nano-silver and other nano-particles have the safety risk of entering the body through a skin barrier; the antibacterial material prepared by completely adopting a chemical synthesis method often has reagent residues or components harmful to the skin and the like, is easy to cause adverse reactions such as sensitization and the like on the skin, and has poor affinity with the skin. (3) Lack of binding capacity and resistance to washing. The common antibacterial agent and leather lack the binding capacity, and under the washing or using condition, the antibacterial material can be washed out or migrated, and then the antibacterial function is lost.

Disclosure of Invention

The invention is designed aiming at the defects of the antibacterial, mildew-proof and skin-friendly performances of leather, and overcomes the defects of high antibacterial price, poor leather binding capacity, skin sensitization and the like in the prior art. According to the method, oxidized chitosan double quaternary ammonium salt is adopted to pretanning and/or retanning naked leather or wet blue leather and the like, aldehyde groups react with leather collagen, and quaternary ammonium salt groups are introduced into the leather, so that the leather is endowed with antibacterial, mildew-proof and skin-friendly performances.

The purpose of the invention is realized by the following technical measures:

1. a manufacturing method of antibacterial, mildew-proof and skin-friendly leather is characterized by comprising the following steps: (1) pre-tanning: the method comprises the following steps of (1) carrying out the treatment in a rotary drum at normal temperature, weighing 100 parts by weight of alkali leather, deliming and softening according to a conventional process, and adding 50-80 parts by weight of normal-temperature water; weighing 8-12 parts by weight of salt, adding into a rotary drum, and rotating for 10 min; weighing 0.4-0.6 part by weight of 85% formic acid, diluting with 4-6 parts by weight of water, adding into a rotary drum from a drum shaft, and rotating for 10-30 min; weighing 0.8-1.5 parts by weight of concentrated sulfuric acid with the concentration of 98%, dissolving and diluting the concentrated sulfuric acid with 16-30 parts by weight of water, and cooling to normal temperature; firstly adding 1/3 sulfuric acid solution, and rotating for 10-20 min; then adding 1/3 sulfuric acid solution, and rotating for 10-20 min; and adding the rest sulfuric acid solution, and rotating for 60-180 min. Weighing 0.5-4.0 parts by weight of oxidized chitosan biquaternary ammonium salt, adding 5-20 parts by weight of water to dissolve, adding from a drum shaft, and rotating for 30-120 min; the subsequent steps are carried out according to the conventional process; (2) the leather is separately post-treated in wet dyeing and finishing: weighing 100 parts by weight of wet blue leather or wet white leather, performing conventional retanning, neutralization, dyeing, fatliquoring, fixing and draining; adding 80-200 parts by weight of water at the temperature of 30-45 ℃; weighing 1.0-4.0 parts by weight of oxidized chitosan biquaternary ammonium salt, dissolving with 10-20 parts by weight of water, adding into a rotary drum, rotating for 30-120 min, and discharging liquid; adding 150-250 parts by weight of normal temperature water, rotating for 5-30 min, and taking out of the drum; the subsequent process is carried out according to a conventional method.

2. The method for manufacturing the antibacterial, mildewproof and skin-friendly leather according to claim 1, wherein the oxidized chitosan biquaternary ammonium salt is a product of the chitosan biquaternary ammonium salt oxidized by sodium periodate, the oxidation degree is 5-50%, and the molecule of the oxidized chitosan biquaternary ammonium salt contains aldehyde groups and quaternary ammonium groups.

3. The method for manufacturing antibacterial, mildewproof and skin-friendly leather according to claim 1, wherein the key indexes of the antibacterial, mildewproof and skin-friendly leather are as follows: (1) the bacteriostasis rate of the leather to escherichia coli and staphylococcus aureus is more than or equal to 75 percent; (2) the inhibition rate of the leather on the gross mucor, the aspergillus niger and the aspergillus flavus is more than or equal to 75 percent; (3) the Primary Irritation Index (PII) of the leather to the skin was < 0.4.

The invention has the following advantages:

(1) the bonding performance is good: the oxidized chitosan double quaternary ammonium salt molecule contains a plurality of aldehyde groups, and can be subjected to chemical reaction with amino groups in skin collagen and the like to form covalent bond crosslinking, so that the oxidized chitosan double quaternary ammonium salt molecule is firmly combined with leather to generate a tanning effect;

(2) the antibacterial and mildewproof performance is durable: due to the good bonding performance, the leather can be firmly bonded with leather, and can resist washing and migration. The defects that a common antibacterial material depends on the physical adsorption effect with leather, has weak adhesive capacity, is not washable, is easy to migrate and has non-durable antibacterial and mildewproof performance are overcome;

(3) the antibacterial and mildewproof performance is excellent: according to the method, the chitosan biquaternary ammonium salt is introduced into the leather through the aldehyde group, and more quaternary ammonium salt groups are introduced than the common quaternary ammonium salt under the same condition, so that the leather has better antibacterial and mildew-proof properties. The bacteriostasis rate of the leather to escherichia coli and staphylococcus aureus is more than or equal to 75 percent; the inhibition rate of the leather on the gross mucor, the aspergillus niger and the aspergillus flavus is more than or equal to 75 percent;

(4) the skin-friendly performance is good: chitosan is known to have excellent biocompatibility and has been widely used for biomaterials. The oxidized chitosan biquaternary ammonium salt is a chitosan derivative, the skeleton structure of the oxidized chitosan biquaternary ammonium salt is derived from natural chitosan, and compared with a synthetic antibacterial and antifungal material, the derivative prepared from the oxidized chitosan biquaternary ammonium salt still has good biological performance. The finished leather has good affinity with skin, and does not cause adverse reactions such as irritation, sensitization and the like. Is particularly suitable for the finished leather products such as underwear, high-grade gloves and the like which are contacted with the skin. The Primary Irritation Index (PII) of the leather to the skin is less than 0.4;

(5) the process has good matching property: the oxidized chitosan biquaternary ammonium salt is added during the pretanning, so that the effect of aldehyde tanning can be achieved, and meanwhile, the quaternary ammonium salt has positive charges, so that the penetration of a chrome tanning agent can be facilitated, and the surface over-tanning can be avoided. The prepared wet blue leather has antibacterial and mildewproof effects. The oxidized chitosan biquaternary ammonium salt is added in the post-treatment, and the positive charge of the quaternary ammonium salt has a fixing effect on an anion material, so that the leather can absorb anion fatting agents, dyes and the like. Especially has excellent color fixing effect on anionic dyes.

Detailed Description

While the invention has been described in detail in the following for the purpose of illustration, it is to be understood that this invention is not limited thereto but is intended to cover various modifications and changes therein which may be made by those skilled in the art without departing from the spirit and scope of the invention.

Application example 1

The following operations are carried out in a tanning drum at ambient temperature:

(1) weighing 100kg of alkali skin of cow leather, and performing conventional deliming and softening;

(2) weighing 70kg of water, adding the water into a rotary drum, adding 10kg of table salt, and rotating for 10 minutes;

(3) weighing 0.5kg of formic acid with the concentration of 85%, dissolving the formic acid with 5kg of water uniformly, adding 1/2 volumes of formic acid solution from a drum shaft, rotating for 10 minutes, then adding the rest formic acid solution from the drum shaft, and rotating for 10 minutes;

(4) weighing 1.0kg of sulfuric acid with the concentration of 98%, dissolving the sulfuric acid with 20kg of water uniformly, cooling the solution to the normal temperature, adding 1/3 volumes of sulfuric acid solution from a drum shaft, and rotating the drum shaft for 20 minutes; then adding 1/3 volume of sulfuric acid solution, and rotating for 20 minutes; finally, adding the residual formic acid solution from the drum shaft, and rotating for 180 minutes;

(5) weighing 0.5kg of oxidized chitosan biquaternary ammonium salt with the oxidation degree of 50%, adding 5kg of water for dissolving, adding from a drum shaft, and rotating for 60 minutes;

(6) adding 8kg of chromium powder and rotating for 4 hours. The subsequent operation is carried out according to the conventional chrome tanning technology.

Application example 2

Adding oxidized chitosan biquaternary ammonium salt in the post-treatment process:

(1) weighing 100kg of wet blue leather, and performing conventional retanning, neutralization, filling, greasing and dyeing;

(2) adding 100kg of hot water with the temperature of 40 ℃;

(3) weighing 4kg of oxidized chitosan quaternary ammonium salt with the oxidation degree of 30%, dissolving 20kg of water, and adding from a drum shaft;

(4) rotating for 120min, and discharging liquid;

(5) adding 150kg of normal temperature water, rotating for 5min, discharging liquid, and discharging from the drum.

Application example 3

Firstly, pretanning by using oxidized chitosan quaternary ammonium salt with the oxidation degree of 40%, and then treating by using oxidized chitosan quaternary ammonium salt with the oxidation degree of 20% in the post-treatment:

(1) weighing 100kg of sheep skin alkali skin;

(2) deliming, softening and pickling;

(3) adding 1kg of oxidized chitosan quaternary ammonium salt with the oxidation degree of 40% into the pickle liquor, and rotating for 30 minutes;

(4) then the tanning is finished according to the conventional process;

(5) weighing 100kg of sheep blue wet leather;

(6) retanning, neutralizing, filling, dyeing, fatliquoring, formic acid fixing and then discharging liquid according to a conventional process;

(7) adding 80kg of hot water with the temperature of 35 ℃, adding 2kg of oxidized chitosan quaternary ammonium salt with the oxidation degree of 20%, rotating for 60 minutes, and discharging liquid;

(8) adding 150kg of normal temperature water, rotating for 10 minutes, and discharging liquid;

(9) and then the finished leather is obtained according to the conventional process.

Claims (3)

1. A manufacturing method of antibacterial, mildew-proof and skin-friendly leather is characterized by comprising the following steps: (1) pre-tanning: the method comprises the following steps of (1) carrying out the treatment in a rotary drum at normal temperature, weighing 100 parts by weight of alkali leather, deliming and softening according to a conventional process, and adding 50-80 parts by weight of normal-temperature water; weighing 8-12 parts by weight of salt, adding into a rotary drum, and rotating for 10 min; weighing 0.4-0.6 part by weight of 85% formic acid, diluting with 4-6 parts by weight of water, adding into a rotary drum from a drum shaft, and rotating for 10-30 min; weighing 0.8-1.5 parts by weight of concentrated sulfuric acid with the concentration of 98%, dissolving and diluting the concentrated sulfuric acid with 16-30 parts by weight of water, and cooling to normal temperature; firstly adding 1/3 sulfuric acid solution, and rotating for 10-20 min; then adding 1/3 sulfuric acid solution, and rotating for 10-20 min; adding the rest sulfuric acid solution, and rotating for 60-180 min; weighing 0.5-4.0 parts by weight of oxidized chitosan biquaternary ammonium salt, adding 5-20 parts by weight of water to dissolve, adding from a drum shaft, and rotating for 30-120 min; the subsequent steps are carried out according to the conventional process; (2) the leather is separately post-treated in wet dyeing and finishing: weighing 100 parts by weight of wet blue leather or wet white leather, performing conventional retanning, neutralization, dyeing, fatliquoring, fixing and draining; adding 80-200 parts by weight of water at the temperature of 30-45 ℃; weighing 1.0-4.0 parts by weight of oxidized chitosan biquaternary ammonium salt, dissolving with 10-20 parts by weight of water, adding into a rotary drum, rotating for 30-120 min, and discharging liquid; adding 150-250 parts by weight of normal temperature water, rotating for 5-30 min, and taking out of the drum; the subsequent process is carried out according to a conventional method.

2. The method for manufacturing the antibacterial, mildewproof and skin-friendly leather according to claim 1, wherein the oxidized chitosan biquaternary ammonium salt is a product of the chitosan biquaternary ammonium salt oxidized by sodium periodate, the oxidation degree is 5-50%, and the molecule of the oxidized chitosan biquaternary ammonium salt contains aldehyde groups and quaternary ammonium groups.

3. The method for manufacturing antibacterial, mildewproof and skin-friendly leather according to claim 1, wherein the key indexes of the antibacterial, mildewproof and skin-friendly leather are as follows: (1) the bacteriostasis rate of the leather to escherichia coli and staphylococcus aureus is more than or equal to 75 percent; (2) the inhibition rate of the leather on the gross mucor, the aspergillus niger and the aspergillus flavus is more than or equal to 75 percent; (3) the Primary Irritation Index (PII) of the leather to the skin was < 0.4.