Energy-saving retanning and filling process of white embryo leather and leather

Abstract

The present application relates to the field of leather processing technology, and specifically discloses an energy-saving retanning and filling process for raw leather and leather. The energy-saving retanning and filling process comprises: placing the raw leather into a rotary drum, adding water, adding a treatment liquid, rotating the drum, adding an acrylic retanning agent, rotating the drum, adding animal protein powder, rotating the drum, adding a fatliquor, rotating the drum, adding an organic acid, rotating the drum, adding chromium powder, rotating the drum, adding an organic acid salt, rotating the drum, and draining the liquid; adding water to the rotary drum, rotating the drum, and draining the liquid; the treatment liquid is mainly made of the following raw materials: water and sodium silicate. This process not only reduces costs but also enables the leather to have the advantages of high tensile strength, high elongation at break, and high tear strength, meeting market demand.

Description

Technical Field

[0001] The present application relates to the technical field of wool leather processing, and more specifically, to an energy-saving retanning and filling process for wool leather white embryo skin and the wool leather. Background Art

[0002] Fur leather refers to leather products with a fleece surface on one side and a leather surface on the other, such as cotton-leather hats, cotton-leather jackets, and snow boots. The processing of fur leather primarily involves soaking the raw wool, soaking it in water, shearing it, fleshing it, degreasing it, pickling it, white tanning it, filling it, and washing it to obtain the raw leather. The raw leather then undergoes retanning and filling, dyeing, drying, finishing, and surface coating to obtain the leather. Retanning and filling the raw leather gives it a firmer, fuller appearance. Related Art: A retanning and filling process for raw leather skins comprises placing the raw leather skin and water into a drum, adding sodium formate, rotating the drum, adding an acrylic retanning agent, rotating the drum, adding melamine, rotating the drum, adding animal protein powder, rotating the drum, adding a fatliquor and a grease dispersant, rotating the drum, adding formic acid, rotating the drum, adding chrome powder, rotating the drum, adding a chrome tanning agent, rotating the drum, adding sodium acetate, rotating the drum, adding baking soda, rotating the drum, draining the drum, and then washing with water, draining the drum to complete the retanning and filling process. The leather obtained by this process has a maximum tensile strength of 11 kg / 1.27 cm and a maximum tear strength of 10 kg / cm, which cannot be further improved. Summary of the Invention

[0003] In order to improve the tensile strength and tear strength of wool leather, the present application provides an energy-saving retanning and filling process for white embryo leather and the wool leather.

[0004] In a first aspect, the present application provides an energy-saving retanning and filling process for white leather, which adopts the following technical solution:

[0005] The energy-saving retanning and filling process of white leather comprises the following steps:

[0006] S1, the white embryo skin of hair leather is dropped into rotary drum and water is added, then treatment solution is added, rotation is processed 70-110min, add acrylic acid retanning agent, rotation is processed 50-70min, add animal protein powder, rotation is processed 20-40min, add fatliquor, rotation is processed 50-70min, add organic acid, rotation is processed 50-70min, add chrome powder, rotation is processed 50-70min, add organic acid salt, rotation is processed 40-80min, discharge;

[0007] S2, adding water to the drum, rotating for 10-40 minutes, draining, and completing the retanning and filling process;

[0008] The treatment liquid is mainly made of the following raw materials in parts by weight: 1000 parts of water and 50-70 parts of sodium silicate.

[0009] The leather obtained by adopting the energy-saving retanning and filling process for white leather of the present application is firm, plump, soft, has good gloss and uniformity, is easy to care for, and has a tensile strength of ≥11 kg / 1.27 cm, an elongation at break of >41%, and a tear strength of >10 kg / cm, thus having the advantages of high tensile strength, high elongation at break, and high tear strength. Furthermore, the tensile strength loss rate after 50 washings is less than 3%, and the breaking strength loss rate after 50 washings is less than 2%, thus providing the leather with good strength retention, extending its service life, and meeting market demand.

[0010] Adding white embryo leather and treatment liquid into the drum, the sodium silicate therein can not only neutralize the charge on the surface of the white embryo leather, but also has excellent penetration effect, and can also promote its absorption and fixation of chromium powder and animal protein powder, so as to achieve deep penetration, bonding and cross-linking effects, improve the tensile strength, elongation at break and tear strength of the leather, and also increase the service life of the leather, so that the leather exhibits excellent comprehensive performance.

[0011] Furthermore, in step S1, the treatment liquid is added to the drum twice. After the first addition of the treatment liquid, the drum is rotated for 20-40 minutes, and after the second addition of the treatment liquid, the drum is rotated for 50-70 minutes. The weight ratio of the treatment liquid added for the first time to the treatment liquid added for the second time is (1-3):(1-3). In various embodiments, the weight ratio of the treatment liquid added for the first time to the treatment liquid added for the second time is 1:1. The weight ratio can also be set to 1:2, 1:3, 2:1, 2:3, 3:1, 3:2, etc. as needed.

[0012] In step S1, the organic acid is added to the drum three times, and after the first addition of the organic acid, the drum is rotated for 10-30 minutes, after the second addition of the organic acid, the drum is rotated for 10-30 minutes, and after the third addition of the organic acid, the drum is rotated for 10-30 minutes, and the weight ratio of the first addition of the treatment liquid, the second addition of the treatment liquid, and the third addition of the treatment liquid is (1-3): (1-3): (1-3). In multiple embodiments, the weight ratio of the first addition of the treatment liquid and the second addition of the treatment liquid is 1:1:1, and the weight ratio can also be set to 1:1:3, 1:2:1, 1:3:3, 3:1:1, 3:1:3, 3:2:1, etc. as needed.

[0013] In step S1, the organic acid salt is added to the drum twice, and after the first addition of the organic acid salt, the drum is rotated for 20-40 minutes, and after the second addition of the organic acid salt, the drum is rotated for 20-40 minutes, and the weight ratio of the first addition of the organic acid salt and the second addition of the organic acid salt is (1-3): (1-3). In multiple embodiments, the weight ratio of the first addition of the organic acid salt and the second addition of the organic acid salt is 1:1, and the weight ratio can also be set to 1:2, 1:3, 2:1, 2:3, 3:1, 3:2, etc. as needed.

[0014] Optionally, the weight ratio of the white embryo leather, treatment liquid, acrylic acid retanning agent, animal protein powder, fatliquor, organic acid, chromium powder, and organic acid salt is 7000:(750-850):(420-500):(320-380):(90-110):(270-330):(350-420):(500-580).

[0015] By adopting the above technical solution, the weight ratio of the white embryo leather, treatment liquid, acrylic retanning agent, animal protein powder, fatliquor, organic acid, chromium powder and organic acid salt is optimized to increase the stability of the retanning and filling of the white embryo leather.

[0016] Optionally, in step S1, the weight ratio of the white embryo leather and water is 7:(80-120); in step S2, the weight ratio of the white embryo leather and water is 7:(100-140).

[0017] By adopting the above technical solution, the amount of water added in step S1 and the amount of water added in step S2 are optimized, so that the white leather skin is fully dispersed in the water, the uniformity of the mixing is increased, the stability of the retanning filling of the white leather skin is ensured, and the quality of the leather is also guaranteed.

[0018] Optionally, the white embryo leather is a white embryo leather obtained by pickling, white tanning, filling and washing the raw leather, and the pH value of the washing liquid after the washing process is 4.5-5.0.

[0019] By adopting the above technical solution, the pH value of the washed white leather is optimized, thereby increasing the stability of the retanning and filling of the white leather cloth.

[0020] Furthermore, each piece of white leather has a weight of 0.5-3kg, a thickness of 10-30mm, and an area of ​​0.3-1.5m 2 Preferably, each piece of leather white embryo has a weight of 0.5-1kg, a thickness of 15-20mm, and an area of ​​0.5-1m 2 In various embodiments, each piece of leather has a weight of 0.7 kg, a thickness of 17 mm, and an area of ​​0.74 m 2The weight can be set to 0.5kg, 1kg, 1.3kg, 1.5kg, 1.8kg, 2kg, 2.5kg, 3kg, etc. as needed. The thickness can be set to 10mm, 13mm, 15mm, 20mm, 23mm, 25mm, 28mm, 30mm, etc. as needed. The area can also be set to 0.3m 2 , 0.5m 2 , 0.8m 2 , 1m 2 , 1.3m 2 , 1.5m 2 wait.

[0021] Optionally, the raw materials of the treatment liquid further include 10-20 parts by weight of sulfonated polyamide, and the sulfonated polyamide is prepared by the following method:

[0022] T1. Under inert gas protection, diethylenetriamine was added to ethanol for the first time, and the mixture was mixed. Ethyl acrylate was added for the first time, and the mixture was stirred for 26-30 hours. Diethylenetriamine was added for the second time, and the mixture was stirred for 46-50 hours. Ethyl acrylate was added for the second time, and the mixture was stirred for 25-30 hours. P-phenylenediamine was added, and the mixture was stirred for 46-50 hours. Ethanol was removed by distillation under reduced pressure to obtain intermediate a.

[0023] T2. Under inert gas protection, add intermediate a to acetonitrile, mix, add 1,3-propane sultone, heat to reflux, stir for 10-15 hours, cool to room temperature, filter, and wash to obtain intermediate b;

[0024] T3. Add intermediate b to water, mix, add sodium ethoxide, stir for 10-15 hours, dry to remove ethanol and water, and obtain sulfonated polyamide.

[0025] By adopting the above technical scheme, sulfonated polyamide is added to the treatment liquid. In the sulfonated polyamide, diethylenetriamine is used as the core, and the number and degree of branching are increased through alternating addition reaction and amidation reaction. Combined with the mutual cooperation of p-phenylenediamine, 1,3-propane sultone and sodium ethanol, sulfonate groups are introduced at the chain ends of the polyamide to obtain sulfonated polyamide, so that the sulfonated polyamide is branched and contains a large number of secondary amine groups, tertiary amine groups, amide groups, phenyl groups, sulfonates, etc., which greatly enhances its interaction with sodium silicate and enhances the mechanical properties of wool leather.

[0026] In the preparation method of sulfonated polyamide, diethylenetriamine contains two primary amino groups. Ethyl acrylate is added, and the carbon-carbon double bond reacts with the two primary amino groups. Ester groups are introduced with the diethylenetriamine as the core, increasing the number of branches. Diethylenetriamine is then added, and one of the primary amino groups undergoes an amidation reaction with the ester group, introducing a primary amino group and increasing the length of the branches. Ethyl acrylate is added, and the carbon-carbon double bond reacts with the primary amino group, introducing an ester group and increasing the number of branches. p-phenylenediamine is added, and one of the primary amino groups undergoes an amidation reaction with the ester group, introducing a primary amino group and increasing the length of the branches. 1,3-Propane sultone is added, and the sultone group undergoes a ring-opening reaction with the primary amino group, introducing a sulfonic acid group. Sodium ethoxide is added, and the sodium ions undergo an exchange reaction with the sulfonic acid groups, introducing a sodium sulfonate salt, to obtain the sulfonated polyamide. Sulfonated polyamide is branched and contains a large number of secondary amine groups, tertiary amine groups, amide groups, phenyl groups, sulfonates, etc., which significantly increase its interaction with sodium silicate, improve the tensile strength, elongation at break, and tear strength of leather, and also enhance the water washing stability and increase the service life of leather.

[0027] In various embodiments, the amount of sulfonated polyamide added is 15 parts by weight. The amount can also be set to 10 parts by weight, 13 parts by weight, 18 parts by weight, 20 parts by weight, etc. as needed.

[0028] Optionally, the weight ratio of the first addition of diethylenetriamine, the first addition of ethyl acrylate, the second addition of diethylenetriamine, the second addition of ethyl acrylate, p-phenylenediamine, 1,3-propane sultone, and sodium ethoxide is (4-6):(18-22):(18-22):(35-43):(35-43):(38-48):(22-26).

[0029] By adopting the above technical solution, the weight ratios of the first addition of diethylenetriamine, the first addition of ethyl acrylate, the second addition of diethylenetriamine, the second addition of ethyl acrylate, p-phenylenediamine, 1,3-propane sultone, and sodium ethoxide are optimized to facilitate addition reaction, amidation reaction, ring-opening reaction, exchange reaction, etc., thereby ensuring the stability of the preparation of sulfonated polyamide and the use effect.

[0030] Furthermore, the weight ratio of diethylenetriamine, ethanol, acetonitrile and water added for the first time is (2-3):(150-400):(150-400):(150-400). Preferably, the weight ratio of diethylenetriamine, ethanol, acetonitrile and water added for the first time is (2-3):(200-300):(200-300):(200-300). In multiple embodiments, the weight ratio of diethylenetriamine, ethanol, acetonitrile and water added for the first time is 1:100:100:100. In another embodiment, the weight ratio is 1:125:125:125. In another embodiment, the weight ratio is 3:250:250:250. The weight ratio can also be set to 1:75:200:75, 1:200:200:75, 1:100:100:150, 1:150:100:100, 3:150:400:150, 3:400:400:150, 3:200:200:300, 3:300:200:200, etc. as needed.

[0031] Optionally, the acrylic retanning agent is one or more of acrylic retanning agent RST, acrylic retanning agent FB, acrylic retanning agent RG-BR01, and acrylic retanning agent RG-BR03; the fatliquor is one or more of sulfonated oil, castor oil, castor oil phosphate, and sulfited neat's foot oil.

[0032] By adopting the above technical solution, the acrylic acid retanning agent and fatliquor are optimized, which facilitates the selection of acrylic acid retanning agent and fatliquor. In multiple embodiments, the acrylic acid retanning agent is acrylic acid retanning agent RST. The acrylic acid retanning agent can also be set as acrylic acid retanning agent FB, acrylic acid retanning agent RG-BR01, acrylic acid retanning agent RG-BR03, a mixture of acrylic acid retanning agent RST and acrylic acid retanning agent FB, a mixture of acrylic acid retanning agent RST and acrylic acid retanning agent RG-BR03, etc. In multiple embodiments, the fatliquor is sulfonated oil. The fatliquor can also be set as castor oil phosphate, sulfited neat's foot oil, a mixture of sulfonated oil and castor oil phosphate, a mixture of sulfonated oil and sulfited neat's foot oil, etc., as needed.

[0033] Optionally, the organic acid is one or more of formic acid, oxalic acid, propionic acid, and butyric acid; the organic acid salt is one or more of sodium acetate, sodium oxalate, potassium acetate, and potassium oxalate.

[0034] By adopting the above technical solution, the organic acid and organic acid salt are optimized, which facilitates the selection of organic acids and organic acid salts. In multiple embodiments, the organic acid is formic acid, and the organic acid can also be set to oxalic acid, propionic acid, butyric acid, a mixture of formic acid and oxalic acid, a mixture of formic acid and propionic acid, a mixture of formic acid and butyric acid, etc. as needed. In multiple embodiments, the organic salt is sodium acetate, and the organic acid salt can also be set to sodium oxalate, potassium acetate, potassium oxalate, a mixture of sodium oxalate and sodium acetate, a mixture of potassium oxalate and potassium acetate, etc. as needed.

[0035] Optionally, the temperature of the water in step S1 is 30-40°C; the temperature of the water in step S2 is 5-10°C.

[0036] By adopting the above technical solution, the water temperature in step S1 is limited, which is convenient for retanning and filling the white embryo leather. The water temperature in step S2 is also limited, which is convenient for washing.

[0037] Furthermore, the rotation speed of the drum in step S1 is 5-15 r / min; the rotation speed of the drum in step S2 is 5-15 r / min. In various embodiments, the rotation speed of the drum in step S1 is 10 r / min, which can also be set to 5 r / min, 8 r / min, 13 r / min, 15 r / min, etc. as needed. In various embodiments, the rotation speed of the drum in step S2 is 10 r / min, which can also be set to 5 r / min, 8 r / min, 13 r / min, 15 r / min, etc. as needed.

[0038] In a second aspect, the present application provides a wool leather, which adopts the following technical solution:

[0039] The wool leather is obtained by adopting the energy-saving retanning and filling process of the wool leather white embryo skin, retanning and filling the wool leather white embryo skin, and then dyeing, drying and finishing, and surface coating.

[0040] In summary, this application has at least the following beneficial effects:

[0041] 1. The energy-saving retanning and filling process for raw leather skins of this application mixes the raw leather skins with a treatment solution, eliminating the need for melamine, oil dispersants, chrome tanning agents, and baking soda. It also reduces the use of acrylic retanning agents, fatliquors, and chrome powder, thereby lowering costs. The process also achieves a tensile strength of ≥11 kg / 1.27 cm, an elongation at break of >41%, and a tear strength of >10 kg / cm, demonstrating the advantages of high tensile strength, high elongation at break, and high tear strength. Furthermore, the tensile strength loss after 50 washes is less than 3%, and the breaking strength loss after 50 washes is less than 2%, demonstrating good strength retention, extending service life, and meeting market demand.

[0042] 2. Sulfonated polyamide is also added to the treatment liquid of this application, and the performance of wool leather is improved through the synergistic effect of sulfonated polyamide and sodium silicate. In the preparation method of sulfonated polyamide, diethylenetriamine and ethyl acrylate are coordinated to cause alternating addition reactions and amidation reactions to form polyamide. Paraphenylenediamine is further added to introduce primary amino groups and phenyl groups. 1,3-Propane sultone is added to undergo a ring-opening reaction. Sodium ethanol is added to undergo an exchange reaction, and sodium sulfonate is introduced to obtain sulfonated polyamide. This not only introduces a large number of active groups but also increases its interaction with sodium silicate, thereby improving the tensile strength, elongation at break, and tear strength of the wool leather. It also enhances water washing stability and extends its service life. DETAILED DESCRIPTION

[0043] To make this application easier to understand, the following examples will be used to further illustrate this application. These examples are for illustrative purposes only and are not intended to limit the scope of application of this application. Unless otherwise specified, the raw materials or components used in this application can be obtained through commercial channels or conventional methods.

[0044] Preparation Example

[0045] Preparation Example 1

[0046] Sulfonated polyamide, which is prepared by the following method:

[0047] T1. Under nitrogen protection and stirring at a rate of 500 r / min, 5 g of diethylenetriamine was added to 500 g of ethanol for the first time, and the mixture was stirred for 5 minutes. 20 g of ethyl acrylate was added for the first time, and the mixture was stirred for 28 hours. 20 g of diethylenetriamine was added for the second time, and the mixture was stirred for 48 hours. 38.8 g of ethyl acrylate was added for the second time, and the mixture was stirred for 28 hours. 38.1 g of p-phenylenediamine was added, and the mixture was stirred for 48 hours. Ethanol was removed by distillation under reduced pressure to obtain intermediate a.

[0048] T2. Under nitrogen protection and a stirring rate of 500 r / min, intermediate a was added to 500 g of acetonitrile, and the mixture was stirred for 5 min. 43 g of 1,3-propane sultone was added, and the mixture was heated to reflux and stirred for 13 h. The mixture was cooled to 23 ° C., filtered, and washed twice with 300 g of acetonitrile to obtain intermediate b.

[0049] T3. Add intermediate b to 500 g of water at a stirring rate of 500 r / min, stir for 5 min, add 24 g of sodium ethoxide, stir for 13 h, and dry to remove ethanol and water to obtain sulfonated polyamide.

[0050] Preparation Example 2

[0051] Sulfonated polyamide, which is prepared by the following method:

[0052] T1. Under nitrogen protection and stirring at a rate of 500 r / min, 4 g of diethylenetriamine was added to 500 g of ethanol for the first time, and the mixture was stirred for 5 minutes. 18 g of ethyl acrylate was added for the first time, and the mixture was stirred for 26 hours. 22 g of diethylenetriamine was added for the second time, and the mixture was stirred for 50 hours. 43 g of ethyl acrylate was added for the second time, and the mixture was stirred for 30 hours. 35 g of p-phenylenediamine was added, and the mixture was stirred for 46 hours. Ethanol was removed by distillation under reduced pressure to obtain intermediate a.

[0053] T2. Under nitrogen protection and a stirring rate of 500 r / min, intermediate a was added to 500 g of acetonitrile, stirred for 5 min, 38 g of 1,3-propane sultone was added, heated to reflux, stirred for 10 h, cooled to 23 ° C, filtered, and washed twice with 300 g of acetonitrile to obtain intermediate b.

[0054] T3. Add intermediate b to 500 g of water at a stirring rate of 500 r / min, stir for 5 min, add 26 g of sodium ethoxide, stir for 15 h, and dry to remove ethanol and water to obtain sulfonated polyamide.

[0055] Preparation Example 3

[0056] Sulfonated polyamide, which is prepared by the following method:

[0057] T1. Under nitrogen protection and stirring at a rate of 500 r / min, 6 g of diethylenetriamine was added to 500 g of ethanol for the first time, and the mixture was stirred for 5 minutes. 22 g of ethyl acrylate was added for the first time, and the mixture was stirred for 30 hours. 18 g of diethylenetriamine was added for the second time, and the mixture was stirred for 46 hours. 35 g of ethyl acrylate was added for the second time, and the mixture was stirred for 26 hours. 43 g of p-phenylenediamine was added, and the mixture was stirred for 50 hours. Ethanol was removed by distillation under reduced pressure to obtain intermediate a.

[0058] T2. Under nitrogen protection and a stirring rate of 500 r / min, intermediate a was added to 500 g of acetonitrile, and the mixture was stirred for 5 min. 48 g of 1,3-propane sultone was added, and the mixture was heated to reflux and stirred for 15 h. The mixture was cooled to 23 ° C., filtered, and washed twice with 300 g of acetonitrile to obtain intermediate b.

[0059] T3. Add intermediate b to 500 g of water at a stirring rate of 500 r / min, stir for 5 min, add 22 g of sodium ethoxide, stir for 10 h, dry to remove ethanol and water, and obtain sulfonated polyamide.

[0060] Example

[0061] Example 1

[0062] The energy-saving retanning and filling process of white leather comprises the following steps:

[0063] S0. Prepare white embryo leather and prepare treatment solution.

[0064] S01. The white embryo leather is made from sheepskin, which has been soaked, sheared, fleshed, degreased, pickled, white tanned, filled, and washed. The pH value of the washing liquid after the washing process is 4.8. Each piece of white embryo leather weighs 0.7 kg, is 17 mm thick, and has an area of ​​0.74 m2. 2 , the moisture content is 15wt%.

[0065] S02. The treatment liquid is made of the following raw materials in parts by weight: 1000 g of water and 28 g of sodium silicate.

[0066] The treatment liquid was prepared by the following method: sodium silicate was added to water, and the mixture was stirred for 5 minutes to obtain the treatment liquid.

[0067] S1. At a rotation speed of 10 r / min, 7 kg of white embryo leather was put into a drum and 100 kg of water at a temperature of 38° C. was added.

[0068] Add 400g of the treatment liquid first and rotate for 30 minutes. Add 400g of the treatment liquid a second time and rotate for 60 minutes. Add 460g of acrylic acid retanning agent and rotate for 60 minutes. Add 346g of animal protein powder and rotate for 30 minutes. Add 100g of fatliquor and rotate for 60 minutes.

[0069] Add 100g of organic acid-formic acid for the first time and rotate for 20 minutes. Add 100g of organic acid-formic acid for the second time and rotate for 20 minutes. Add 100g of organic acid-formic acid for the third time and rotate for 20 minutes. Add 385g of chromium powder and rotate for 60 minutes.

[0070] 270 g of organic acid salt - sodium acetate was added for the first time, and the mixture was rotated for 30 minutes. 270 g of organic acid salt - sodium acetate was added for the second time, and the mixture was rotated for 30 minutes, and the liquid was drained.

[0071] Among them, the acrylic acid retanning agent is selected from Desail's acrylic acid retanning agent RST; the animal protein powder is selected from the hydrolyzed animal protein of Hebei Liqia Biological; and the fatliquor is selected from the sulfonated oil SS of Lujing Fenghua.

[0072] S2. Add 120 kg of water at a temperature of 8° C. into the drum at a rotation speed of 10 r / min, rotate for 20 minutes, drain the liquid, and complete the retanning and filling process.

[0073] S3, dyeing, drying and finishing the white embryo leather after the treatment in step S2, and surface coating the leather to obtain the leather.

[0074] Example 2

[0075] The energy-saving retanning and filling process of white embryo leather differs from that of Example 1 in that step S1 and step S2 are different.

[0076] Step S1 is specifically as follows: 7 kg of white embryo leather is put into a drum at a rotation speed of 10 r / min and 80 kg of water at a temperature of 30° C. is added.

[0077] Add 425g of the treatment liquid for the first time and rotate for 40 minutes. Add 425g of the treatment liquid for the second time and rotate for 70 minutes. Add 420g of acrylic acid retanning agent and rotate for 50 minutes. Add 380g of animal protein powder and rotate for 40 minutes. Add 90g of fatliquor and rotate for 50 minutes.

[0078] Add 110g of organic acid-formic acid for the first time and rotate for 10 minutes. Add 110g of organic acid-formic acid for the second time and rotate for 30 minutes. Add 110g of organic acid-formic acid for the third time and rotate for 10 minutes. Add 350g of chromium powder and rotate for 50 minutes.

[0079] 290 g of organic acid salt - sodium acetate was added for the first time, and the mixture was rotated for 20 min. 290 g of organic acid salt - sodium acetate was added for the second time, and the mixture was rotated for 20 min, and the liquid was drained.

[0080] Step S2 is specifically as follows: adding 140 kg of water at a temperature of 5° C. into the drum at a rotation speed of 10 r / min, rotating the drum for 10 minutes, draining the liquid, and completing the retanning and filling process.

[0081] Example 3

[0082] The energy-saving retanning and filling process of white embryo leather differs from that of Example 1 in that step S1 and step S2 are different.

[0083] Step S1 is specifically as follows: 7 kg of white embryo leather is put into a drum at a rotation speed of 10 r / min and 120 kg of water at a temperature of 40° C. is added.

[0084] Add 375g of the treatment liquid first and rotate for 20 minutes. Add 375g of the treatment liquid a second time and rotate for 50 minutes. Add 500g of acrylic acid retanning agent and rotate for 70 minutes. Add 320g of animal protein powder and rotate for 20 minutes. Add 110g of fatliquor and rotate for 70 minutes.

[0085] Add 90g of organic acid-formic acid for the first time and rotate for 30 minutes. Add 90g of organic acid-formic acid for the second time and rotate for 10 minutes. Add 90g of organic acid-formic acid for the third time and rotate for 30 minutes. Add 420g of chromium powder and rotate for 70 minutes.

[0086] 250 g of organic acid salt - sodium acetate was added for the first time, and the mixture was rotated for 40 minutes. 250 g of organic acid salt - sodium acetate was added for the second time, and the mixture was rotated for 40 minutes, and the liquid was drained.

[0087] Step S2 is specifically as follows: adding 100 kg of water at a temperature of 10° C. into the drum at a rotation speed of 10 r / min, rotating the drum for 40 minutes, draining the liquid, and completing the retanning and filling process.

[0088] Example 4

[0089] The energy-saving retanning and filling process for white embryo leather is different from that of Example 1 in that the amount of sodium silicate added to the raw materials of the treatment liquid in step S0 is different, and the amount of sodium silicate added is 50 g.

[0090] Example 5

[0091] The energy-saving retanning and filling process for white embryo leather is different from that of Example 1 in that the amount of sodium silicate added to the raw materials of the treatment liquid in step S0 is different, and the amount of sodium silicate added is 70 g.

[0092] Example 6

[0093] The energy-saving retanning and filling process for white leather differs from Example 1 in that 15 g of sulfonated polyamide is further added to the raw materials of the treatment liquid in step S0. The sulfonated polyamide is prepared using the method of Preparation Example 1. In the preparation method of the treatment liquid, the sulfonated polyamide is added to water together with sodium silicate to obtain the treatment liquid.

[0094] Example 7

[0095] The energy-saving retanning and filling process for white embryo leather differs from Example 6 in that the raw materials of the treatment liquid in step S0 have different sources of sulfonated polyamide, and the sulfonated polyamide is prepared by the method of Preparation Example 2.

[0096] Example 8

[0097] The energy-saving retanning and filling process for white embryo leather differs from Example 6 in that the raw materials of the treatment liquid in step S0 have different sources of sulfonated polyamide, and the sulfonated polyamide is prepared by the method of Preparation Example 3.

[0098] Example 9

[0099] The energy-saving retanning and filling process for white embryo leather differs from Example 6 in that an equal amount of sulfonated polyamide is used to replace sodium silicate in the raw material of the treatment liquid in step S0.

[0100] Example 10

[0101] The energy-saving retanning and filling process for white embryo leather differs from that of Example 6 in that an equal amount of sodium formate replaces sodium silicate in the raw material of the treatment liquid in step S0.

[0102] Example 11

[0103] The energy-saving retanning and filling process for white embryo leather differs from Example 6 in that the raw material of the treatment liquid in step S0 is replaced by an equal amount of dimethylpropylsulfonamide ethyl methacrylate.

[0104] Example 12

[0105] The energy-saving retanning and filling process for white embryo leather differs from that of Example 6 in that an equal amount of polyamide is used to replace sulfonated polyamide in the raw material of the treatment liquid in step S0.

[0106] The polyamide was prepared by the following method: Under nitrogen protection and stirring at a rate of 500 r / min, 5 g of diethylenetriamine was added to 500 g of ethanol for the first time, and the mixture was stirred for 5 minutes. 20 g of ethyl acrylate was added for the first time, and the mixture was stirred for 28 hours. 20 g of diethylenetriamine was added for the second time, and the mixture was stirred for 48 hours. 38.8 g of ethyl acrylate was added for the second time, and the mixture was stirred for 28 hours. 38.1 g of p-phenylenediamine was added, and the mixture was stirred for 48 hours. The ethanol was removed by distillation under reduced pressure to obtain the polyamide.

[0107] Comparative Example

[0108] Comparative Example 1

[0109] The energy-saving retanning and filling process for white embryo leather differs from that of Example 1 in that step S1 is different.

[0110] Step S1 is specifically as follows: 7 kg of white embryo leather is put into a drum at a rotation speed of 10 r / min and 100 kg of water at a temperature of 38° C. is added.

[0111] Add 153g of sodium formate and rotate for 30 minutes. Add 540g of acrylic acid retanning agent and rotate for 60 minutes. Add 480g of melamine and rotate for 30 minutes. Add 453g of animal protein powder and rotate for 30 minutes. Add 120g of fatliquor a, 93g of fatliquor b, and 13g of oil dispersant and rotate for 60 minutes.

[0112] Add 90g of organic acid-formic acid for the first time and rotate for 30 minutes. Add 90g of organic acid-formic acid for the second time and rotate for 30 minutes. Add 600g of chrome powder and rotate for 30 minutes. Add 300g of chrome tanning agent and rotate for 60 minutes.

[0113] Add 240g of organic acid salt - sodium acetate for the first time, rotate and process for 30 minutes, add 240g of organic acid salt - sodium acetate for the second time, rotate and process for 30 minutes. Add 46g of baking soda for the first time, rotate and process for 30 minutes, add 46g of baking soda for the second time, rotate and process for 30 minutes, and drain.

[0114] Among them, the acrylic acid retanning agent is selected from Desail's acrylic acid retanning agent RST; the animal protein powder is selected from the hydrolyzed animal protein of Liqia Biological; the fatliquor a is selected from the sulfonated oil SS of Lujing Fenghua; the fatliquor b is selected from the castor oil phosphate ester of Dexin Chemical; the oil dispersant is selected from the oil dispersant D-305 of Zhongjing Oil; and the chrome tanning agent is basic chromium sulfate.

[0115] Comparative Example 2

[0116] The energy-saving retanning and filling process for white embryo leather differs from Example 1 in that an equal amount of sodium formate replaces sodium silicate in the raw material of the treatment liquid in step S0.

[0117] Performance testing

[0118] The leathers obtained in Examples 1-12 and Comparative Examples 1-2 were respectively taken as samples, and the tensile strength, elongation at break, and tear strength of the samples were tested according to ASTM D2209-00 and ASTM D4704-12. The test results are shown in Table 1.

[0119] Table 1 Test results

[0120]

[0121]

[0122] As can be seen from Table 1, the leather obtained by the energy-saving retanning and filling process for white leather of the present application has a transverse tensile strength of 11.4-16.2 kg / 1.27 cm, a longitudinal tensile strength of 11.1-15.7 kg / 1.27 cm, a transverse elongation at break of 43.0-55.3%, a longitudinal elongation at break of 41.4-54.2%, a transverse tear strength of 10.8-13.1 kg / cm, and a longitudinal tear strength of 10.4-12.7 kg / cm, giving the leather superior strength. Furthermore, the tensile strength loss rate after 50 washes is less than 3%, and the breaking strength loss rate after 50 washes is less than 2%, giving the leather excellent strength retention and increasing its service life.

[0123] Comparing Example 1 with Comparative Example 1, it can be seen that the energy-saving retanning and filling process for white embryo leather of the present application not only eliminates melamine, oil dispersant, chrome tanning agent and baking soda, but also reduces the use of acrylic retanning agent, fatliquor and chromium powder, while also increasing the tensile strength and breaking strength of the leather, so that the leather exhibits better performance.

[0124] Comparing Example 1 with Example 6, sodium silicate was added to the raw materials of the treatment liquid in Example 1, while sodium silicate and sulfonated polyamide were added to the raw materials of the treatment liquid in Example 6. It can be seen that the simultaneous addition of sodium silicate and sulfonated polyamide to the raw materials of the treatment liquid can increase the tensile strength and breaking strength of the wool leather.

[0125] Comparing Example 6 with Examples 10-12, the raw materials of the treatment liquid of Example 10 include sodium formate and sulfonated polyamide; the raw materials of the treatment liquid of Example 11 include sodium silicate and dimethylpropylsulfonamide ethyl methacrylate; the raw materials of the treatment liquid of Example 12 include sodium silicate and polyamide; and the raw materials of the treatment liquid of Example 6 include sodium silicate and sulfonated polyamide. It can be seen that the simultaneous addition of sodium silicate and sulfonated polyamide to the raw materials of the treatment liquid and the synergistic effect between them can achieve better performance of wool leather.

[0126] It should be noted that the embodiments described above are only used to explain the present application and do not constitute any limitation to the present application. The present application has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present application may be modified as specified within the scope of the claims of the present application, and the invention may be revised without departing from the scope and spirit of the present application. Although the present application described therein relates to specific methods, materials and embodiments, it does not mean that the present application is limited to the specific examples disclosed therein. On the contrary, the present application can be extended to all other methods and applications with the same function.

Claims

1. An energy-saving retanning and filling process for white embryo leather, characterized by: The steps include: S1, the white embryo skin of hair leather is dropped into rotary drum and water is added, then treatment solution is added, rotation is processed 70-110min, add acrylic acid retanning agent, rotation is processed 50-70min, add animal protein powder, rotation is processed 20-40min, add fatliquor, rotation is processed 50-70min, add organic acid, rotation is processed 50-70min, add chrome powder, rotation is processed 50-70min, add organic acid salt, rotation is processed 40-80min, discharge; S2, adding water to the drum, rotating for 10-40 minutes, draining, and completing the retanning and filling process; The treatment liquid is mainly made of the following raw materials in parts by weight: 1000 parts of water, 50-70 parts of sodium silicate, and 10-20 parts of sulfonated polyamide; The sulfonated polyamide is prepared by the following method: T1. Under inert gas protection, diethylenetriamine was added to ethanol for the first time, and the mixture was mixed. Ethyl acrylate was added for the first time, and the mixture was stirred for 26-30 hours. Diethylenetriamine was added for the second time, and the mixture was stirred for 46-50 hours. Ethyl acrylate was added for the second time, and the mixture was stirred for 25-30 hours. P-phenylenediamine was added, and the mixture was stirred for 46-50 hours. Ethanol was removed by distillation under reduced pressure to obtain intermediate a. T2. Under inert gas protection, add intermediate a to acetonitrile, mix, add 1,3-propane sultone, heat to reflux, stir for 10-15 hours, cool to room temperature, filter, and wash to obtain intermediate b; T3, adding intermediate b to water, adding sodium ethoxide, stirring for 10-15 hours, and drying to remove ethanol and water to obtain sulfonated polyamide; The weight ratio of the first addition of diethylenetriamine, the first addition of ethyl acrylate, the second addition of diethylenetriamine, the second addition of ethyl acrylate, p-phenylenediamine, 1,3-propane sultone, and sodium ethoxide is (4-6):(18-22):(18-22):(35-43):(35-43):(38-48):(22-26).

2. The energy-saving retanning and filling process for white embryo leather according to claim 1, characterized in that: The weight ratio of the white embryo leather, treatment liquid, acrylic acid retanning agent, animal protein powder, fatliquor, organic acid, chromium powder and organic acid salt is 7000:(750-850):(420-500):(320-380):(90-110):(270-330):(350-420):(500-580).

3. The energy-saving retanning and filling process for white embryo leather according to claim 1, characterized in that: In step S1, the weight ratio of the white embryo leather and water is 7:(80-120); in step S2, the weight ratio of the white embryo leather and water is 7:(100-140).

4. The energy-saving retanning and filling process for white embryo leather according to claim 1, characterized in that: The white embryo leather is obtained by pickling, white tanning, filling and washing the raw leather, and the pH value of the washing liquid after the washing process is 4.5-5.

0.

5. The energy-saving retanning and filling process for white embryo leather according to claim 1, characterized in that: The acrylic acid retanning agent is one or more of acrylic acid retanning agent RST, acrylic acid retanning agent FB, acrylic acid retanning agent RG-BR01, and acrylic acid retanning agent RG-BR03; the fatliquor is one or more of sulfonated oil, castor oil, castor oil phosphate, and sulfited neat's foot oil.

6. The energy-saving retanning and filling process for white embryo leather according to claim 1, characterized in that: The organic acid is one or more of formic acid, oxalic acid, propionic acid, and butyric acid; the organic acid salt is one or more of sodium acetate, sodium oxalate, potassium acetate, and potassium oxalate.

7. The energy-saving retanning and filling process for white embryo leather according to claim 1, characterized in that: The temperature of the water in step S1 is 30-40°C; the temperature of the water in step S2 is 5-10°C.

8. Fur leather, characterized by: The energy-saving retanning and filling process of the white embryo leather of the wool leather is adopted, the white embryo leather of the wool leather is retanned and filled, and then the leather is dyed, dried and finished, and the surface is coated to obtain the leather.

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