Retanning process for improving rubbing color fastness of chrome-free tanned punched automobile cushion leather

Abstract

The invention belongs to the technical field of leather manufacturing, and discloses a retanning process for improving the rubbing color fastness of chrome-free tanning punched automobile cushion leather. Comprising the steps of water washing A, pre-dyeing, pre-fatliquoring, aldehyde retanning, neutralizing, fatliquoring A, A filling, dyeing, fatliquoring B, B filling, formic acid fixation A, main fatliquoring, formic acid fixation B, aluminum tanning agent fixation and water washing B. The problem that chrome-free tanning punching automobile seat cushion leather produced through an existing technology is poor in rubbing color fastness is solved, inner and outer dyes of the chrome-free tanning punching automobile seat cushion leather produced through the technology are fixed, the production quality is improved, the product quality is good, and the overall benefits are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of leather manufacturing, and relates to a retanning process for improving the friction color fastness of chrome-free tanned perforated automobile seat cushion leather. Background Art

[0002] With the development of the automobile industry, in order to meet the fashion and comfort requirements of consumers, automobile manufacturers are also considering adding ventilation and heating functions to seats through perforation to improve comfort when designing interior decoration. Originally, the friction color fastness of automobile seat leather mainly depends on the finishing coating, but the leather exposed after perforation makes it easy for the dye to migrate out in the color fastness friction test, especially wet rubbing, which is difficult to pass, because the red dye itself is difficult to dye, which also makes it particularly difficult to wet rubbing. Automobile leather friction test standard: friction color fastness: dry rubbing ≥ 4 / 5, wet rubbing ≥ 4, friction color fastness in alkaline sweat, gasoline, neutral soap solution and other environments ≥ 4. Chinese patent ZL202111145091.4 discloses a leather crust compacting process, which is mainly used to solve the problem of Australian Wetblue having raw material cost advantage in making a compact Nappa design process; Chinese patent ZL20211145074.0 discloses a leather crust manufacturing process for preventing perforated leather from salt frost, which is mainly used to solve the problem of chrome-tanned Nappa leather perforated to expose salt frost design crust leather production process; the above two patents are based on chrome-tanned Wetblue raw materials, and the combination mode and binding sites of chemical materials and raw materials of the present invention for chrome-free tanned white wet are different. Chemical materials are mainly combined with carboxyl groups on the collagen fibers of the Wetblue raw materials and amino groups on the collagen fibers of the WetWhite raw materials, belonging to two systems, so the above two patents cannot solve the technical problem that the present invention wants to solve: to provide a retanning process for improving the friction color fastness of chrome-free tanned perforated automobile seat cushion leather. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a retanning process for improving the friction color fastness of chrome-free tanned perforated automobile seat cushion leather, thereby solving the problem that the chrome-free tanned perforated automobile seat cushion leather produced by the existing process has poor friction color fastness. The chrome-free tanned perforated automobile seat cushion leather produced by the process of the present invention has fixed dyes inside and outside the raw leather, thereby improving the production quality, the product quality is good, and the overall efficiency is improved.

[0004] The existing conventional retanning and dyeing process is generally set up as follows:

[0005] Washing - pre-fatliquoring - aldehyde retanning - neutralization overnight - washing - filling - dyeing - fatliquoring - formic acid fixing - washing.

[0006] The above object of the present invention is achieved through the following technical solutions:

[0007] The invention provides a retanning process for improving the friction color fastness of chrome-free tanned perforated automobile seat cushion leather, comprising washing A-pre-dyeing-pre-fatting-aldehyde retanning-neutralization-fatting A-filling A-dyeing-fatting B-filling B-formic acid fixing A-main fatting-formic acid fixing B-aluminum tanning agent fixing-washing B.

[0008] The above-mentioned retanning process for improving the rubbing color fastness of chrome-free tanned perforated automobile seat cushion leather specifically comprises the following steps:

[0009] S1. Wash A: 250%-300wt% water, 35-40°C, add 0.3-0.5wt% degreasing agent, rotate for 60min;

[0010] S2. Pre-dyeing: 100-150wt% water, 35-40°C, 1wt% dye, rotation for 20min;

[0011] S3. Pre-fatting and aldehyde retanning: liquid ratio 0.8-1.0, internal temperature 30-35 degrees Celsius, add 0.5-1.0wt% sulfited fish oil fatliquor, rotate for 20 minutes; add 0.8-1.0wt% formic acid, rotate for 30 minutes, adjust pH to 3.2-3.4; add 1.5wt% modified glutaraldehyde, rotate for 90 minutes.

[0012] S4. Neutralization: Add 1.5-2wt% sodium formate and rotate for 30min; add 0.5-1.0wt% sodium bicarbonate and rotate for 60min; pH is required to be between 5.2-5.5;

[0013] S5. Fat-liquoring A, filling A and dyeing: liquid ratio 0.6-0.8, internal temperature 30-35°C, add 1.0-1.5wt% anionic mineral synthetic oil, rotate for 30min; add 1.0-2.0wt% dispersible synthetic tannin, 0.2% anti-twist agent, 2.0-3.0wt% sulfone synthetic tanning agent, 3.0-4.0wt% wattle bark tannin, 3.5-4wt% phenolsulfonic acid auxiliary synthetic tanning agent, 2.5-3.0wt% collagen powder, 2-3wt% melamine resin tanning agent and rotate for 40min; add 1wt% leveling agent, 3.5wt% dye and rotate for 120min.

[0014] S6. Fatliquoring B: adding 1.0-1.5wt% anionic mineral synthetic oil and 1.0-1.5wt% sulfonated vegetable oil fatliquoring agent, 4-6wt% acrylic polymer retanning agent, rotating for 30min;

[0015] S7 filling B: adding 1.0-2.0wt% synthetic dispersed tannin, 2.0-3.0wt% wattle bark tannin, 2.0-2.5wt% phenol sulfonic acid auxiliary synthetic tanning agent, 1.0-1.5wt% sulfone synthetic tanning agent, rotating for 60min;

[0016] S8. Formic acid fixation A: Add 0.5-0.8% formic acid diluted 1:10 in water and rotate for 20 minutes, adjust the pH to 4.5-4.8;

[0017] S9 main fatliquor: add hot water 150wt%, rotate 10min, internal temperature 50 ℃ -55 ℃; add 2-4wt% natural softener and synthetic polymer composite fatliquor, 1-2wt% lecithin, 4-6wt% polysiloxane polymer fatliquor, rotate 60min;

[0018] S10. Formic acid fixation B and aluminum tanning agent fixation: add 1.0wt% of 1:10 water-diluted formic acid and rotate for 20 minutes; add 1.5wt% of 1:10 water-diluted formic acid and rotate for 60min, requiring pH 3.2-3.4; then add 0.5wt% aluminum tannin and rotate for 20min;

[0019] S11. Washing B: Add 1 wt% of fixing agent during washing: remove from the drum, place on a horse and let it stand; obtain a leather embryo for producing perforated automobile seat cushion leather.

[0020] Furthermore, steps S1. to S11. are sequentially performed in a stainless steel Y-shaped drum.

[0021] The beneficial effects of the present invention compared with the prior art are:

[0022] (1) The existing common practice for the process design of leather blanks is to carry out filling-dyeing-fatting-fixing. In this process, the penetration of the dye mainly depends on the dosage (forming concentration difference), rotation time and other factors. The fixation of the dye mainly relies on formic acid. After adding a large amount of formic acid, only the surface fixation can be guaranteed, and the dye inside the leather blank is not fixed. It is difficult to pass the test of the friction color fastness of the punched finished leather. In the present invention, a collaborative method is adopted. During pre-dyeing, the dye is allowed to occupy a position on the surface. During the main dyeing, the dye can penetrate deeper into the longitudinal section. After the formic acid is filled, the pH is lowered to allow the dye inside the leather blank to be initially fixed. After the main fatting, formic acid and aluminum tannin are fixed, and the fixing agent is fixed during washing. Under the idea, the dye inside and outside the leather blank is guaranteed to be fixed to the maximum extent, and the friction color fastness test can be passed.

[0023] (2) Under the existing process, the dye is unevenly distributed inside the leather. After the finished leather is punched, the color inside the hole is easily inconsistent with the color on the leather surface, which leads to customer returns. Under the synergistic effect of this process, pre-dyeing is first performed to allow the dye to occupy and combine with the grain layer fibers first, and then the main dyeing is performed in the early stage of filling to allow the dye molecules to penetrate into the reticular layer for dyeing. Only in this way can the dye be evenly distributed in the leather to the greatest extent, which is reflected in the uniform color of the cross section of the leather. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The following are the comparison photos of the color fastness after wet friction of the products of Application Example 1 and Application Example 2. (a) is Application Example 1; (b) is Application Example 2.

[0025] Figure 2 The following are the comparison photos of the color fastness after alkaline sweat of the products of Application Example 1 and Application Example 2. (a) is Application Example 1; (b) is Application Example 2. DETAILED DESCRIPTION

[0026] The present invention is described in detail below by specific examples, but the protection scope of the present invention is not limited. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the experimental equipment, materials, reagents, etc. used can be obtained from commercial channels.

[0027] The invention provides a retanning process for improving the friction color fastness of chrome-free tanned perforated automobile seat cushion leather, comprising washing A-pre-dyeing-pre-fatting-aldehyde retanning-neutralization-fatting A-filling A-dyeing-fatting B-filling B-formic acid fixing A-main fatting-formic acid fixing B-aluminum tanning agent fixing-washing B.

[0028] The following steps are involved:

[0029] S1. Wash A: 250%-300wt% water, 35-40°C, add 0.3-0.5wt% degreasing agent, rotate for 60min;

[0030] S2. Pre-dyeing: 100-150wt% water, 35-40°C, 1wt% dye, rotation for 20min;

[0031] S3. Pre-fatting and aldehyde retanning: liquid ratio 0.8-1.0, internal temperature 30-35 degrees Celsius, add 0.5-1.0wt% sulfited fish oil fatliquor, rotate for 20 minutes; add 0.8-1.0wt% formic acid, rotate for 30 minutes, adjust pH to 3.2-3.4; add 1.5wt% modified glutaraldehyde, rotate for 90 minutes.

[0032] S4. Neutralization: Add 1.5-2wt% sodium formate and rotate for 30min; add 0.5-1.0wt% sodium bicarbonate and rotate for 60min; pH is required to be between 5.2-5.5;

[0033] S5. Fat-liquoring A, filling A and dyeing: liquid ratio 0.6-0.8, internal temperature 30-35°C, add 1.0-1.5wt% anionic mineral synthetic oil, rotate for 30min; add 1.0-2.0wt% dispersible synthetic tannin, 0.2% anti-twist agent, 2.0-3.0wt% sulfone synthetic tanning agent, 3.0-4.0wt% wattle bark tannin, 3.5-4wt% phenolsulfonic acid auxiliary synthetic tanning agent, 2.5-3.0wt% collagen powder, 2-3wt% melamine resin tanning agent and rotate for 40min; add 1wt% leveling agent, 3.5wt% dye and rotate for 120min.

[0034] S6. Fatliquoring B: adding 1.0-1.5wt% anionic mineral synthetic oil and 1.0-1.5wt% sulfonated vegetable oil fatliquoring agent, 4-6wt% acrylic polymer retanning agent, rotating for 30min;

[0035] S7 filling B: adding 1.0-2.0wt% synthetic dispersed tannin, 2.0-3.0wt% wattle bark tannin, 2.0-2.5wt% phenol sulfonic acid auxiliary synthetic tanning agent, 1.0-1.5wt% sulfone synthetic tanning agent, rotating for 60min;

[0036] S8. Formic acid fixation A: Add 0.5-0.8% formic acid diluted 1:10 in water and rotate for 20 minutes, adjust the pH to 4.5-4.8;

[0037] S9 main fatliquor: add hot water 150wt%, rotate 10min, internal temperature 50 ℃ -55 ℃; add 2-4wt% natural softener and synthetic polymer composite fatliquor, 1-2wt% lecithin, 4-6wt% polysiloxane polymer fatliquor, rotate 60min;

[0038] S10. Formic acid fixation B and aluminum tanning agent fixation: add 1.0wt% of 1:10 water-diluted formic acid and rotate for 20 minutes; add 1.5wt% of 1:10 water-diluted formic acid and rotate for 60min, requiring pH 3.2-3.4; then add 0.5wt% aluminum tannin and rotate for 20min;

[0039] S11. Washing B: Add 1 wt% of fixing agent during washing: remove from the drum, place on a horse and let it stand; obtain a leather embryo for producing perforated automobile seat cushion leather.

[0040] The process of the present invention is described in detail below through examples and comparative examples.

[0041] Example 1 (Workshop Large-Scale Production)

[0042] A retanning process for improving the friction color fastness of chrome-free tanned perforated automobile seat leather;

[0043] Wherein S1-S11 are all measured by shaving weight %.

[0044] S1. Washing: 250wt% water, 35℃, add 0.5wt% degreasing agent, rotate for 60min.

[0045] S2. Pre-dyeing: 100% water, 35°C, 1wt% red dye, rotation for 20min;

[0046] S3. Liquid ratio 0.6, internal temperature 30°C, add 0.5wt% sulfited fish oil fatting agent, rotate for 20 minutes; add 0.8wt% formic acid, rotate for 30 minutes, measure pH: 3.2; add 1.5wt% modified glutaraldehyde, rotate for 90 minutes.

[0047] S4. Neutralize in the same bath, add 1.5wt% sodium formate, rotate for 30min; add 0.5wt% sodium bicarbonate, rotate for 60min; measure pH: 5.3;

[0048] S5. Fat-liquoring A, filling A, dyeing: liquid ratio 0.6, internal temperature 30-35°C, add 1.5wt% anionic mineral synthetic oil, rotate for 30min; add 1.5wt% dispersible synthetic tannin, 0.2wt% anti-twist agent, 2.0wt% sulfone synthetic tanning agent, 3.0wt% wattle bark tannin, 3.5wt% phenolsulfonic acid auxiliary synthetic tanning agent, 3.0wt% collagen powder, 2.5wt% melamine resin tanning agent and rotate for 40min; add 1wt% leveling agent, 3.5wt% red dye and rotate for 120min.

[0049] S6. Fatliquoring B: adding 1.5wt% anionic mineral synthetic oil and 1.0wt% sulfonated vegetable oil fatliquoring agent, 4.5% acrylic polymer retanning agent and rotating for 30min;

[0050] S7 filling B: adding 1.5wt% synthetic dispersed tannin, 3.0wt% wattle bark tannin, 2.5wt% phenol sulfonic acid auxiliary synthetic tanning agent, 1.5wt% sulfone synthetic tanning agent, rotating for 60min;

[0051] S8. Fix A with formic acid, add 0.8 wt% of 1:10 water-diluted formic acid, rotate for 20 min, and adjust pH to 4.5;

[0052] S9. Main fatliquor: add 150wt% hot water, rotate for 10min, internal temperature 55°C. Add 2wt% natural softener and synthetic polymer composite fatliquor, 1.5wt% lecithin, 4wt% polysiloxane polymer fatliquor at one time, rotate for 60min;

[0053] S10. Formic acid fixation B: add 1.0 wt% formic acid (10-fold dilution), rotate for 20 min; add 1.5 wt% formic acid (10-fold dilution), rotate for 60 min, pH 3.3; then add 0.5 wt% aluminum tannin, rotate for 20 min;

[0054] S11. Add 1 wt% of fixing agent during water washing: remove from the drum, place on a horse and let it stand; obtain a skin embryo.

[0055] Steps S1 to S11 are sequentially performed in a stainless steel Y-shaped drum.

[0056] The leather blanks produced by the above-mentioned retanning process are processed into perforated automobile seat cushion leather products and tested for wet friction color fastness.

[0057] Comparative Example 1

[0058] The process comprises the following steps: the following are all calculated in shaving weight wt%;

[0059] S1 retanning filling: liquid ratio 0.5, temperature 35°C, add 4wt% acrylic polymer retanning agent, rotate for 30min, then add 2wt% disperse tannins, 10wt% wattle bark tannin, 8wt% sulfone synthetic tanning agent, 4wt% melamine resin tanning agent, 5wt% animal protein, rotate for 180min.

[0060] S2 dyeing: add 4.5wt% red dye at one time and rotate for 120min

[0061] S3 Fat Liquor: Add 5wt% sulfonated vegetable oil, 2wt% sulfited fish oil, and 2wt% lecithin at one time and rotate for 60 minutes

[0062] S4 water washing: 300 wt% water at 30°C, rotating for 15 min, twice to obtain the embryo.

[0063] The produced leather embryos are processed into perforated automobile seat cushion leather products and tested for wet friction color fastness.

[0064] Comparative Example 2

[0065] The process comprises the following steps: the following are all calculated in shaving weight wt%;

[0066] S1. Washing: 250wt% water, 35℃, add 0.5wt% degreasing agent, rotate for 60min.

[0067] S2. Pre-dyeing, 100% water, 35°C, 1wt% red dye, rotation for 20min.

[0068] S3. Liquid ratio 0.6, internal temperature 30°C, add 1.0wt% sulfited fish oil fatting agent, rotate for 20 minutes; add 0.8wt% formic acid, rotate for 30 minutes, measure pH: 3.5; add 1.5wt% modified glutaraldehyde, rotate for 90 minutes.

[0069] S4. Neutralize in the same bath, add 1.5wt% sodium formate, rotate for 30min; add 0.5wt% sodium bicarbonate, rotate for 60min; measure pH: 5.4.

[0070] S5 retanning filling: liquid ratio 0.5, temperature 35°C, add 4wt% acrylic polymer retanning agent, rotate for 30min, then add 2wt% disperse tannins, 10wt% wattle bark tannin, 8.5wt% sulfone synthetic tanning agent, 5wt% melamine resin tanning agent, 4.5wt% vegetable protein, rotate for 180min.

[0071] S6 dyeing: "Add 4.5 wt% red dye at once and rotate for 120 min.

[0072] S7 Fatliquor: Add 2wt% sulfonated vegetable oil, 2wt% sulfited fish oil, 1.5wt% lecithin, and 3wt% polysiloxane polymer fatliquor at one time and rotate for 60 minutes.

[0073] S8 Water washing: 300 wt% water at 30°C, rotating for 15 min, twice to obtain the embryonic skin.

[0074] The produced leather embryos are processed into perforated automobile seat cushion leather products and tested for wet friction color fastness.

[0075] Comparative Example 3:

[0076] The process comprises the following steps: the following are all calculated in shaving weight wt%;

[0077] S1. Washing: 250wt% water, 35°C, add 0.5% degreasing agent, rotate for 60min;

[0078] S2. Liquid ratio 0.6, internal temperature 35°C, add 0.5wt% sulfited fish oil fatting agent, rotate for 20 minutes; add 0.8wt% 1:10 water-diluted formic acid, rotate for 30 minutes, measure pH: 3.2; add 1.5% modified glutaraldehyde, rotate for 90 minutes.

[0079] S3. Neutralize in the same bath, add 1.5wt% sodium formate, rotate for 30min; add 0.5wt% sodium bicarbonate, rotate for 60min; measure pH: 5.3;

[0080] S4. Filling: liquid ratio 0.6, internal temperature 35 ° C, add 1.5wt% anionic mineral synthetic oil, rotate for 30min; add 1.5wt% dispersible synthetic tannin, 0.2wt% anti-twist agent, 2.0wt% sulfone synthetic tanning agent, 3.0wt% wattle bark tannin, 3.5wt% phenol sulfonic acid auxiliary synthetic tanning agent, 3.0wt% collagen powder, 2.5wt% melamine resin tanning agent rotate for 40min;

[0081] S5. Dyeing: Add 1wt% leveling agent and 3.5wt% red dye, and rotate for 120min.

[0082] S6. Fatliquoring: adding 2.5wt% anionic mineral synthetic oil and 3.0wt% sulfonated vegetable oil fatliquoring agent, 4.5% acrylic polymer retanning agent and rotating for 30min;

[0083] S7. Main fatliquor: add 150wt% hot water, rotate for 10min, internal temperature 55°C. Add 2wt% natural softener and synthetic polymer composite fatliquor, 2wt% lecithin, 5wt% polysiloxane polymer fatliquor at one time, rotate for 60min;

[0084] S8 Formic acid fixation: add 1.0wt% of 1:10 water-diluted formic acid and rotate for 20min; add 1.5wt% of 1:10 water-diluted formic acid and rotate for 60min, pH 3.2 required;

[0085] S9. Wash with water, take out of the drum, and let it stand to obtain the skin embryo.

[0086] The leather embryos produced are processed into perforated automobile seat cushion leather products and tested for wet friction color fastness.

[0087] Application Example 1

[0088] The solution of Example 1 was produced in a workshop production line to obtain a skin embryo.

[0089] The leather embryos produced are processed into perforated automobile seat cushion leather products and tested for wet friction color fastness.

[0090] Application Example 2

[0091] The scheme of comparative example 3 was produced in a workshop production line to obtain a skin embryo.

[0092] The leather embryos produced are processed into perforated automobile seat cushion leather products and tested for wet friction color fastness.

[0093] The perforated automobile seat cushion leathers prepared in Example 1, Comparative Examples 1-3, and Application Examples 1-2 were tested by the following method:

[0094] According to the Technical Conditions for Supply of Perforated Leather for Passenger Cars JF08-1008-2010 of a certain automobile company and the DINEN ISO 11640 standard, the test was carried out. The sample was stretched 10% along the friction direction and a load of 10N was applied. After the test, the color fastness to staining was evaluated in accordance with the provisions of GB / T 251-2008.

[0095] Wet friction

[0096] The samples were immersed in demineralized water for 1 hour, and the samples could not touch each other. Then the samples were taken out and the excess water on the sample surface was removed with filter paper. The samples were placed in a vacuum drying container for drying, and the vacuum pressure was maintained at 5 kPa for 2 minutes, and then the normal pressure was restored. This process was repeated more than 2 times. During the friction test, the friction was repeated 500 times.

[0097] Alkaline sweat

[0098] After soaking the friction cloth in alkaline sweat, squeeze or wipe off the excess liquid to make the residual alkaline sweat about 1g. During the friction test, rub back and forth 100 times.

[0099] To verify the effect, red, the color with the worst rubbing fastness, was used as a production sample for comparison.

[0100] The results are shown in the following table:

[0101]

[0102] According to the results, Example 1 has better wet water friction color fastness than Comparative Examples 1, 2 and 3, and the wet friction fastness alkaline sweat results are more different. After large-scale use in the production line, the process of Example 1 can still meet the requirements, and the use of the process of the present invention can meet the automotive leather friction test standards. The main reason is that the process design of the present invention adopts an integrated collaborative design, which ensures that the dye molecules and the grain layer fibers are first combined in place during pre-dyeing, so that the main dyeing can penetrate into the reticular layer, and the solid acid before the main fat-liquoring can fix the dye of the reticular layer; the use of a polysiloxane polymer fat-liquoring agent in conjunction with the main fat-liquoring can form a protective film on the grain layer and the reticular layer to prevent the dye from being taken out during wet rubbing, thereby making the leather produced by the process of the present invention have a significantly better wet friction color fastness.

[0103] Although the present invention has been described in detail above by general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made on the basis of the scheme of the present invention are all within the scope of protection claimed by the present invention.

Claims

1. A retanning process for improving the friction color fastness of chrome-free tanned perforated automobile seat leather, characterized in that: Including washing A-pre-dyeing-pre-fatting-aldehyde retanning-neutralization-fatting A-filling A-dyeing-fatting B-filling B-formic acid fixing A-main fatting-formic acid fixing B-aluminum tanning agent fixing-washing B.

2. A retanning process for improving the rubbing color fastness of chrome-free tanned perforated automobile seat leather as claimed in claim 1, characterized in that: The water washing A is: 250%-300wt% water, 35-40°C, adding 0.3-0.5wt% degreasing agent, rotating for 60min; Pre-dyeing is: 100-150wt% water, 35-40°C, 1wt% dye, rotation for 20min.

3. A retanning process for improving the rubbing color fastness of chrome-free tanned perforated automobile seat leather as claimed in claim 1, characterized in that: The pre-fatting and aldehyde retanning are as follows: liquid ratio 0.8-1.0, internal temperature 30-35 degrees Celsius, adding 0.5-1.0wt% sulfited fish oil fatting agent, rotating for 20 minutes; adding 0.8-1.0wt% formic acid, rotating for 30 minutes, adjusting pH to 3.2-3.4; adding 1.5wt% modified glutaraldehyde, rotating for 90 minutes.

4. A retanning process for improving the rubbing color fastness of chrome-free tanned perforated automobile seat cushion leather as claimed in claim 1, characterized in that: The method comprises the following steps: adding 1.5-2 wt % sodium formate and rotating for 30 min; adding 0.5-1.0 wt % sodium bicarbonate and rotating for 60 min; and the pH value is required to be between 5.2 and 5.

5.

5. A retanning process for improving the rubbing color fastness of chrome-free tanned perforated automobile seat leather as claimed in claim 1, characterized in that: Fat-liquoring A, filling A and dyeing are as follows: liquid ratio 0.6-0.8, internal temperature 30-35°C, adding 1.0-1.5wt% anionic mineral synthetic oil, rotating for 30 minutes; adding 1.0-2.0wt% dispersible synthetic tannin, 0.2% anti-twist agent, 2.0-3.0wt% sulfone synthetic tanning agent, 3.0-4.0wt% wattle bark tannin, 3.5-4wt% phenolsulfonic acid auxiliary synthetic tanning agent, 2.5-3.0wt% collagen powder, 2-3wt% melamine resin tanning agent, rotating for 40 minutes; adding 1wt% leveling agent, 3.5wt% dye, rotating for 120 minutes.

6. A retanning process for improving the rubbing color fastness of chrome-free tanned perforated automobile seat leather as claimed in claim 1, characterized in that: Fatliquoring B is as follows: adding 1.0-1.5wt% anionic mineral synthetic oil and 1.0-1.5wt% sulfonated vegetable oil fatliquoring agent, 4-6wt% acrylic acid polymer retanning agent, and rotating for 30 minutes.

7. A retanning process for improving the rubbing color fastness of chrome-free tanned perforated automobile seat leather as claimed in claim 1, characterized in that: Filling B is as follows: adding 1.0-2.0wt% of synthetic dispersed tannin, 2.0-3.0wt% of wattle bark tannin, 2.0-2.5wt% of phenolsulfonic acid auxiliary synthetic tanning agent, 1.0-1.5wt% of sulfone synthetic tanning agent, and rotating for 60 minutes.

8. A retanning process for improving the rubbing color fastness of chrome-free tanned perforated automobile seat leather as claimed in claim 1, characterized in that: Formic acid fixation A: add 0.5-0.8% of 1:10 water-diluted formic acid and rotate for 20 minutes to adjust the pH to 4.5-4.

8.

9. A retanning process for improving the rubbing color fastness of chrome-free tanned perforated automobile seat leather as claimed in claim 1, characterized in that: The main fatliquor is as follows: add 150wt% hot water, rotate for 10min, and keep the internal temperature at 50℃-55℃; add 2-4wt% natural softener and synthetic polymer composite fatliquor, 1-2wt% lecithin, and 4-6wt% polysiloxane polymer fatliquor at one time, and rotate for 60min.

10. A retanning process for improving the rubbing color fastness of chrome-free tanned perforated automobile seat leather as claimed in claim 1, characterized in that: Formic acid fixation B and aluminum tanning agent fixation are: add 1.0wt% of 1:10 water-diluted formic acid and rotate for 20 minutes; add 1.5wt% of 1:10 water-diluted formic acid and rotate for 60 minutes, requiring pH 3.2-3.4; then add 0.5wt% aluminum tannin and rotate for 20 minutes.

Images