Ultra-short process high-quality leather making method and the leather produced

Abstract

This invention belongs to the field of leather processing technology, disclosing an ultra-short process for high-quality leather production and the resulting leather. Using raw hides, tanned leather, or greige as raw materials, the process involves pre-drying, followed by impregnation with an ethanol solution containing Tween, extrusion, and treatment with a long-chain silane coupling agent, ultimately followed by low-temperature drying. The core of this invention lies in Tween's ability to effectively inhibit the hydrolysis reaction of the silane coupling agent when the moisture content of the hide is between 21% and 40%, preventing premature conversion to highly reactive silanols and ensuring that the silane coupling agent can penetrate evenly and deeply into the leather. Subsequently, by applying relatively mild temperature conditions (20-50°C) and with the assistance of appropriate moisture, the binding reaction between the silane coupling agent and the hide collagen proceeds efficiently and fully. This innovative method not only improves leather production efficiency but also significantly enhances the strength parameters of the leather, achieving the goal of efficient, energy-saving, and cost-controllable leather processing, bringing revolutionary technological progress to the leather industry.

Description

Technical Field

[0001] This invention relates to the field of leather processing technology, and in particular to a method for producing high-quality leather using an ultra-short process and the resulting leather. Background Technology

[0002] As a key component of light industry, the leather tanning industry not only inherits a rich legacy of craftsmanship but also plays an indispensable role in modern life. This industry provides consumers with a wide range of leather products, including everyday footwear and clothing, as well as high-end furniture and furnishings, greatly enhancing people's quality of life and meeting diverse market demands. However, current leather tanning technology faces two major challenges: First, processing delimed raw hides into finished leather requires multiple complex steps, including softening, pickling, tanning, neutralization, retanning, dyeing, and fatliquoring. This process is tedious and time-consuming, severely impacting production efficiency. Second, the extensive use of tanning agents and dyeing materials during processing not only increases costs but also, even with significant investment, often fails to meet the expected strength standards for the final product. Therefore, to promote the sustainable and healthy development of the leather tanning industry and enhance the market competitiveness of leather products, there is an urgent need to develop a highly efficient leather tanning technology that simplifies the production process, reduces manufacturing costs, and ensures high-strength leather.

[0003] Chinese patents CN115747388A, "A method for manufacturing metal-free leather through hydrophobic modification and the resulting leather products," and CN113061670A, "A method for superhydrophobic modification of substances containing collagen fibers and a method for tanning without tanning agents, and leather products," disclose methods for preparing leather by hydrophobically modifying dehydrated hides with long-chain silane coupling agents. While this method significantly simplifies the leather-making process, it faces two major challenges in practical application. First, dehydration with a large amount of solvent is required before long-chain silane coupling agent treatment, and the moisture content of the hide must be strictly controlled between 4wt% and 20wt%. This step significantly increases solvent consumption and chemical costs, hindering effective cost control. Second, the hide treated with long-chain silane coupling agents requires further processing at high temperatures of 60-160℃ to promote the binding of the coupling agent with collagen fibers. This process is not only energy-intensive but also places high demands on production equipment. These factors severely limit the application and promotion of leather tanning technology based on long-chain silane coupling agents in industry.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] To address the problems in the background art, the present invention aims to provide a more efficient, energy-saving, and cost-controllable ultra-short process for high-quality leather making, as well as leather products. This process is simple to operate, easy to implement, and produces soft, full-bodied, and high-strength leather.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] The ultra-short process high-quality leather making method uses bare hide, tanned leather or raw leather as raw materials. After pre-drying the raw materials to a moisture content of 21wt%-40wt%, they are impregnated with an ethanol solution containing Tween, extruded and treated with a long-chain silane coupling agent, and finally dried at low temperature.

[0008] Specifically, based on the weight of the raw materials, the amount of Tween added is 0.1wt%-1wt%, and the amount of ethanol added is 50wt%-200wt%; the long-chain silane coupling agent is C n H 2n+1 (CH3) 3-m SiX m n is an integer between 6 and 18, and X is a group that can be hydrolyzed into silanol.

[0009] Preferably, X includes any one of chloro, methoxy, and ethoxy groups.

[0010] Preferably, the amount of the long-chain silane coupling agent added is 2wt%-18wt% of the raw material weight.

[0011] Preferably, the temperature for the low-temperature drying is 20-50 °C.

[0012] Preferably, the bare skin includes any one of delimed bare skin, softened bare skin, pickled bare skin, and bare skin obtained through a pickling-deacidification process.

[0013] Preferably, the tanned leather includes any one of chrome tanned leather, aluminum tanned leather, zircon tanned leather, zeolite tanned leather, multi-metal tanning agent tanned leather, vegetable tanned leather, aldehyde tanned leather, phenolic synthetic tanning agent tanned leather, and active chlorine tanned leather.

[0014] Preferably, the raw leather is obtained by performing at least one of the processes of retanning, dyeing, and fatliquoring.

[0015] Preferably, the pre-dried raw material is soaked in an ethanol solution containing Tween for 5-120 minutes.

[0016] Preferably, the treatment method using long-chain silane coupling agent is as follows: applying an ethanol solution of long-chain silane coupling agent to the surface of the skin blank for 0.5-60 minutes by rotating a drum, brushing, rolling, or spraying.

[0017] The present invention also discloses leather obtained by any of the ultra-short process high-quality leather making methods described above.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] (1) Significantly reduce solvent consumption and chemical costs: The method of the present invention reduces the dependence on a large amount of solvent and reduces the requirements for the degree of dehydration of the blank, which greatly reduces solvent consumption and chemical costs, bringing significant advantages to production cost control.

[0020] (2) Reduce energy consumption and avoid equipment upgrades: This invention realizes the effective binding of long-chain silane coupling agent with skin collagen at low temperature of 20-50℃, which significantly reduces energy consumption, and the existing equipment can meet the mild drying conditions, avoiding additional equipment investment.

[0021] (3) Simplify the leather making process and improve production efficiency: Compared with the multi-step operation of retanning, dyeing and fatliquoring in traditional leather making process, the method of the present invention shows a high degree of simplification, greatly reduces the leather making process, and thus significantly improves production efficiency.

[0022] (4) Improved leather quality and application range: Leather prepared by traditional techniques often has poor strength, while the method of this invention not only endows the leather with excellent strength properties, but also ensures its soft and full texture. This makes the method of this invention applicable to the processing of various types of leather, effectively broadening the application range and enhancing product value. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to specific embodiments. It should be noted that the following examples are merely illustrative of the invention and do not limit its scope of protection. Those skilled in the art can still make some non-essential improvements and adjustments based on the research content of this invention.

[0024] In traditional processes, before treating leather blanks with long-chain silane coupling agents, the moisture content of the blanks must be strictly controlled to 20 wt% or below using a large amount of solvent. This is because long-chain silane coupling agents readily hydrolyze into silanols upon contact with water, leading to a sharp increase in reactivity. This silanols then rapidly bind to the collagen and deposit on the leather surface, limiting the penetration of the coupling agent and affecting the uniformity of the treatment effect. Furthermore, when long-chain silane coupling agents penetrate the leather, their reactivity with collagen decreases in a low-moisture environment, thus requiring high temperatures (60-160℃) to accelerate the reaction. Therefore, both the use of large amounts of solvent during dehydration and the high-temperature reaction acceleration place high demands on both chemical and energy costs, hindering industrial production. It is important to note that while non-solvent-based methods such as vacuum drying can be used to control the moisture content of the leather blanks to 20 wt% or below, these drying methods cause fiber adhesion within the leather blanks, preventing the silane coupling agent from penetrating.

[0025] The present invention provides an ultra-short process high-quality leather making method, which uses bare hide, tanned leather or raw leather as raw material, pre-drying the raw material to a moisture content of 21wt%-40wt%, then impregnating it with an ethanol solution containing Tween, extruding it and treating it with a long-chain silane coupling agent, and finally drying it at low temperature.

[0026] Specifically, based on the weight of the raw materials, the amount of Tween added is 0.1wt%-1wt%, and the amount of ethanol added is 50wt%-200wt%.

[0027] The long-chain silane coupling agent is C. n H 2n+1 (CH3) 3-m SiX m n is an integer between 6 and 18, and X is a group that can be hydrolyzed into silanol.

[0028] This invention eliminates the need for large amounts of solvents for dehydration and high-temperature tanning methods. This breakthrough is achieved through the use of an ethanol solution containing Tween for impregnation. During this impregnation process, a small amount of Tween achieves multiple effects simultaneously: firstly, because Tween molecules are rich in multiple hydroxyl functional groups, these hydroxyl groups effectively inhibit the hydrolysis of silane coupling agents, preventing premature conversion into highly reactive silanol forms. This ensures that the silane coupling agents can penetrate evenly and deeply into the leather, rather than merely depositing on the surface. Secondly, Tween has a certain degree of hydrophilicity, which helps maintain a relatively constant moisture content in the leather, providing a certain water-retention effect and stabilizing the moisture content within an appropriate range. The amount of ethanol used is significantly reduced compared to existing technologies, making it difficult to achieve dehydration. In this invention, its role is to impregnate collagen fibers, facilitating subsequent silane penetration into the leather.

[0029] Once the silane coupling agent is evenly distributed within the leather, the binding reaction between the silane coupling agent and the leather collagen can proceed efficiently and fully under relatively mild temperature conditions and with the aid of an appropriate amount of moisture. This optimized reaction environment not only promotes the deep integration of the coupling agent with the leather components but also significantly improves the treatment effect, ultimately endowing leather products with superior quality and performance, bringing revolutionary technological progress to the leather industry.

[0030] For appropriate moisture content, the moisture content of the raw material after pre-drying is 21wt%-40wt%. During the impregnation process, Tween can also stabilize the moisture content of the raw material at 21wt%-40wt%, ensuring that the collagen fibers in the raw material remain in a non-adhesive state, facilitating silane penetration. When the moisture content is below 21wt%, although the silane coupling agent can penetrate into the leather, it is difficult to hydrolyze into silanols under low moisture conditions, resulting in low reactivity. Therefore, existing technologies require high-temperature conditions (above 60℃) to promote the hydrolysis of the silane coupling agent and its binding with the leather collagen. When the moisture content exceeds 40wt%, Tween cannot effectively inhibit the hydrolysis of the silane coupling agent, meaning that the silane coupling agent cannot penetrate evenly into the leather, thus affecting the final result.

[0031] It should be noted that, in the embodiments of the present invention, when using silane coupling agents, all long-chain silane coupling agents containing groups that can be hydrolyzed into silanols can achieve the effects of the present invention, such as chloro, methoxy, and ethoxy groups. This is because the silanols generated by the hydrolysis of these silane coupling agents can form a stable bond with skin collagen, achieving the effects of the present invention. In the prior art, long-chain silane coupling agents are often used to perform surface hydrophobic treatment on finished leather to improve its waterproof and stain-resistant properties. The embodiments of the present invention are the first to realize the application of long-chain silane coupling agents in the leather preparation process. Due to their unique hydrophobic, filling, and oily properties, long-chain silane coupling agents, after binding with skin collagen, can effectively disperse collagen fibers, achieving thickening of the leather blank and enhancing the relative lubricity between collagen fibers. With the use of Tween, long-chain silane coupling agents can fully penetrate and stably bind with collagen fibers, not only giving the finished leather excellent softness and fullness but also achieving the sensory effects sought in traditional complex processes. More importantly, because the amount of chemical materials used in the processing is reduced, the chemical components in the finished leather are reduced accordingly, while the fiber content is increased. This change directly promotes a significant improvement in the strength parameters of the finished leather.

[0032] The common treatment method for long-chain silane coupling agents is to apply the mixed solution to the surface of the skin and flesh of the blank by means of a rotating drum, brushing, rolling, or spraying.

[0033] The dosage of long-chain silane coupling agents should be selected adaptively based on the desired effect. Given the clearly defined working principle and effects of long-chain silane coupling agents, those skilled in the art can anticipate the impact of dosage on the effect. Clearly, if the dosage is too low, the effect will be insignificant, resulting in poor leather performance; if the dosage is too high, not only will the cost increase, but the leather will also develop a "plastic feel," losing some of the excellent sensory characteristics unique to genuine leather. For reference, in the embodiments of this invention, the amount of long-chain silane coupling agent added is 2wt%-18wt% of the raw material weight.

[0034] Since this invention does not require controlling the moisture content of the raw materials to be too low, common and simple drying processes can be used to achieve a moisture content of 21wt%-40wt%, such as hanging drying, vacuum drying, stretching drying, nailing drying, and attaching drying. This significantly reduces the requirements for the technical specifications and energy consumption of the processing equipment, making it particularly suitable for industrial production.

[0035] When using ethanol containing Tween to impregnate pre-dried raw materials, the impregnation time can be adaptively selected based on the raw materials, solution, and amount of silane coupling agent to achieve the final leather-making effect. For those skilled in the art, after clarifying the role and dosage of each raw material and the mechanism of action of the embodiments of the present invention, the influence of impregnation time on the final effect is clear. Obviously, if the impregnation time is too short, sufficient impregnation cannot be achieved; if the impregnation time is too long, the ethanol will partially dehydrate, reducing the moisture content in the hide, which is not conducive to the subsequent low-temperature binding of the long-chain silane coupling agent and collagen fibers. For reference, in the embodiments of the present invention, the pre-dried raw materials are impregnated with an ethanol solution containing Tween for 5-120 minutes.

[0036] It is important to note that after soaking in ethanol containing Tween, the subsequent squeezing to remove excess ethanol is crucial. Removing some of the excess ethanol facilitates the uniform penetration of the long-chain silane coupling agent ethanol solution into the leather. Specifically, after squeezing, although trace amounts of ethanol remain in the leather, it is generally in a state of relative ethanol deficiency. Under these conditions, applying the long-chain silane coupling agent ethanol solution to the leather allows the solution to rapidly penetrate the collagen fibers through capillary action, achieving uniform distribution of the long-chain silane coupling agent in the leather within 0.5-60 minutes. If the leather is not soaked in ethanol containing Tween and excess ethanol is not removed beforehand, and instead Tween, ethanol, and the long-chain silane coupling agent are mixed simultaneously for soaking, the long-chain silane coupling agent will not be fully absorbed and evenly distributed in the leather. Therefore, it is essential to strictly follow the sequence of first "soaking in ethanol containing Tween and squeezing to remove excess ethanol," and then "soaking in the long-chain silane coupling agent ethanol solution."

[0037] Generally, the ethanol content in the extruded preform does not exceed 50 wt%. In some preferred embodiments, since it is difficult to achieve an ethanol content of less than 15 wt% using conventional extrusion methods, which is not conducive to industrial production, the ethanol content in the extruded preform can be controlled between 15 wt% and 50 wt%. If the ethanol content is higher than 50 wt%, the ethanol solution of the long-chain silane coupling agent will have difficulty penetrating the collagen fibers through capillary conduction. Therefore, the ethanol content in the extruded preform can be selected by those skilled in the art based on industrial production costs and the desired impregnation effect. From an industrial production perspective, the conventional extrusion processes that can be selected by this invention include extrusion using a water-squeezing machine or a water-squeezing stretching machine.

[0038] Based on the above theory, the amount of ethanol used in the long-chain silane coupling agent ethanol solution can be selectively added according to the desired treatment effect and treatment time. For example, 100 parts by weight of long-chain silane coupling agent can be dissolved in 100-500 parts by weight of ethanol to obtain a long-chain silane coupling agent ethanol solution.

[0039] Among them, applying the long-chain silane coupling agent ethanol solution to the blank is a common method of applying liquid to solid surface, including drum rotation, brushing, or spraying.

[0040] It should be noted that, in the embodiments of the present invention, the leather blanks treated with long-chain silane coupling agents do not need to be treated at high temperatures of 60-160°C; they can be dried at low temperatures. This not only eliminates the need for complex high-temperature treatment equipment but also significantly reduces processing energy consumption. Clearly, the low temperature in the embodiments of the present invention is defined relative to the high temperatures of 60-160°C in the prior art. The present invention can achieve low-temperature drying at 20-50°C and significantly improve leather properties. Commonly used low-temperature drying methods include any one or more of hanging drying, microwave drying, and infrared drying.

[0041] The embodiments of this invention are applicable to the processing of commonly used raw materials in the leather industry, such as bare hides, tanned leather, and raw leather. Exemplarily, bare hides include any one of delimed bare hides, softened bare hides, pickled bare hides, and bare hides obtained through processes such as pickling and deacidification; tanned leather includes any one of chrome-tanned leather, aluminum-tanned leather, zircon-tanned leather, zeolite-tanned leather, multi-metallic tanning agent tanned leather, vegetable-tanned leather, aldehyde-tanned leather, phenolic synthetic tanning agent tanned leather, and active chlorine-tanned leather; raw leather refers to raw leather obtained through at least one of the processes of retanning, dyeing, and fatliquoring.

[0042] To better understand the technical solution provided by the present invention, the following uses several specific examples to illustrate the ultra-short process high-quality leather making method and performance testing provided by the above embodiments of the present invention.

[0043] In the following examples and comparative examples, the softness of the leather was measured using a GT-303 softness tester; the tear strength of the leather was measured using a servo-controlled computer system tensile testing machine.

[0044] Example 1

[0045] Chrome-tanned leather was vacuum dried to obtain a leather blank with a moisture content of 21 wt%. Tween and ethanol were mixed at 0.1 wt% of the weight of the chrome-tanned leather and 120 wt% of the weight of the leather. The mixture of Tween and ethanol was used to impregnate the tanned leather for 60 min. After extrusion, a leather blank impregnated with Tween and ethanol was obtained. 10 wt% of dodecyltriethoxysilane was dissolved in 30 wt% ethanol and brushed onto the flesh side of the leather blank for 60 min. Finally, it was dried at 35°C using low-temperature infrared light to obtain high-quality leather.

[0046] The leather's softness was measured to be 9.2 mm and its tear strength to be 64.3 N / mm. The specific results are shown in Table 1.

[0047] Comparative Example 1

[0048] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 only used 120wt% ethanol to impregnate the tanned leather, without using Tween. The detailed process steps are as follows:

[0049] Chrome-tanned leather was vacuum dried to obtain a leather blank with a moisture content of 21 wt%. The tanned leather was soaked in 120 wt% ethanol based on the weight of the chrome-tanned leather for 60 min. After extrusion, the ethanol-soaked leather blank was obtained. 10 wt% dodecyltriethoxysilane was dissolved in 30 wt% ethanol and brushed onto the flesh side of the leather blank for 60 min. Finally, it was dried at 35°C using low-temperature infrared light to obtain leather.

[0050] The leather's softness was measured to be 5.1 mm and its tear strength to be 16.3 N / mm. The specific results are shown in Table 1.

[0051] Comparative Example 2

[0052] The difference between Comparative Example 2 and Example 1 is that the moisture content of the blank obtained by vacuum drying in Comparative Example 2 is 15 wt%. The detailed process steps are as follows:

[0053] Chrome-tanned leather was vacuum dried to obtain a leather blank with a moisture content of 15 wt%. Tween and ethanol were mixed at 0.1 wt% of the weight of the chrome-tanned leather and 120 wt% of the weight of the leather. The mixture of Tween and ethanol was used to impregnate the tanned leather for 60 min. After extrusion, leather blanks impregnated with Tween and ethanol were obtained. 10 wt% of dodecyltriethoxysilane was dissolved in 30 wt% ethanol and applied to the flesh side of the leather blank for 60 min. Finally, the leather was dried at 35°C using low-temperature infrared ray drying to obtain leather.

[0054] The leather's softness was measured to be 6.4 mm and its tear strength to be 21.9 N / mm. The specific results are shown in Table 1.

[0055] Comparative Example 3

[0056] The difference between Comparative Example 3 and Example 1 is that the moisture content of the blank obtained by vacuum drying in Comparative Example 3 is 45 wt%. The detailed process steps are as follows:

[0057] Chrome-tanned leather was vacuum dried to obtain a leather blank with a moisture content of 45 wt%. Tween and ethanol were mixed at 0.1 wt% of the weight of the chrome-tanned leather and 120 wt% of the weight of the leather. The mixture of Tween and ethanol was used to impregnate the tanned leather for 60 min. After extrusion, a leather blank impregnated with Tween and ethanol was obtained. 10 wt% of dodecyltriethoxysilane was dissolved in 30 wt% ethanol and brushed onto the flesh side of the leather blank for 60 min. Finally, it was dried at 35°C using low-temperature infrared light to obtain leather.

[0058] The leather's softness was measured to be 5.8 mm and its tear strength to be 19.3 N / mm. The specific results are shown in Table 1.

[0059] Comparative Example 4

[0060] The difference between Comparative Example 4 and Example 1 is that Comparative Example 4 did not use ethanol containing Tween to impregnate the raw material and squeeze out excess ethanol. Instead, it directly mixed Tween, ethanol, and a long-chain silane coupling agent to impregnate the raw material. The detailed process steps are as follows:

[0061] Chrome-tanned leather was vacuum dried to obtain a leather blank with a moisture content of 21 wt%. 0.1 wt% Tween, 150 wt% ethanol and 10 wt% dodecyltriethoxysilane based on the weight of the chrome-tanned leather were mixed and brushed onto the flesh side of the leather blank for 120 min. Finally, it was dried at 35°C using low-temperature infrared light to obtain leather.

[0062] The leather's softness was measured to be 4.6 mm and its tear strength to be 13.9 N / mm. The specific results are shown in Table 1.

[0063] Table 1 Test Results

[0064] .

[0065] Based on the test results of Example 1 and Comparative Examples 1-4, it can be seen that in Example 1, the moisture content of the leather blank was controlled within the range of 21wt%-40wt% through vacuum drying. After soaking in a mixed solution of Tween and ethanol, dodecyltriethoxysilane could fully penetrate into the leather blank. Low-temperature drying at an appropriate moisture content and 35°C promoted the full combination of silane and collagen, resulting in high-quality leather with a softness of 9.2 mm and a tear strength of 64.3 N / mm. Although Comparative Example 1 controlled the moisture content of the leather blank within the range of 21wt%-40wt% through vacuum drying, it did not use Tween soaking. This caused the silane to easily hydrolyze into highly reactive silanols upon contact with water, making it difficult to penetrate evenly into the leather blank. The resulting leather had a softness of only 5.1 mm and a tear strength of only 16.3 N / mm. N / mm; Comparative Example 2 controlled the moisture content of the leather blank to 15wt% through vacuum drying. While this low moisture content allowed silanes to easily and evenly penetrate the leather blank, silanes were difficult to bind with the leather collagen at 35°C. Therefore, the resulting leather had poor softness (6.4 mm) and tear strength (21.9 N / mm). Comparative Example 3 controlled the moisture content of the leather blank to 45wt% through vacuum drying. At this high moisture content, Tween could not sufficiently inhibit the hydrolysis of silanes into highly reactive silanols, resulting in insufficient penetration of silanes into the leather blank. The final leather quality was still poor, with a softness of only 5.8 mm and a tear strength of only 19.3 N / mm. Comparative Example 4 did not use ethanol containing Tween to impregnate the raw material and squeeze out excess ethanol. Instead, Tween, ethanol, and a long-chain silane coupling agent were directly mixed and used to impregnate the raw material. This operation resulted in the long-chain silane coupling agent not being fully absorbed and evenly distributed in the leather, leading to poor softness (4.6 mm) and tear strength (13.9 N / mm). The N / mm ratio is poor. Therefore, it is evident that only by controlling the moisture content of the leather blank within the range of 21wt%-40wt%, first soaking it in a mixed solution of "Tween + ethanol" and squeezing out excess ethanol, and then soaking it in ethanol containing long-chain silane coupling agents, can the silane be evenly penetrated into the leather and then fully combined with the leather collagen at a lower drying temperature, ultimately resulting in high-quality leather.

[0066] Example 2

[0067] Using delimed raw hides as raw materials, they are hung-dried to obtain hide blanks with a moisture content of 40wt%. Tween and ethanol, based on 0.1wt% of the weight of the delimed raw hides, are mixed and the Tween-ethanol mixture is used to soak the raw hides for 120 min. After extrusion, hide blanks soaked in Tween and ethanol are obtained. 18wt% of n-hexyltrichlorosilane is dissolved in 90wt% ethanol and applied to the flesh side of the hide blanks by rotating them in a drum for 30 min. Finally, the hides are hung-dried at a low temperature of 25℃ to obtain high-quality leather.

[0068] The leather was measured to have a softness of 8.1 mm and a tear strength of 86.1 N / mm.

[0069] Example 3

[0070] Using retanned raw leather as raw material, it is stretched and dried to obtain a leather blank with a moisture content of 30wt%. Tween and ethanol are mixed at 0.5wt% of the weight of the retanned raw leather and 50wt% of the weight of the raw leather. The mixture of Tween and ethanol is used to soak the raw leather for 5 minutes. After extrusion, a leather blank soaked in Tween and ethanol is obtained. 2wt% of octadecyltrimethoxysilane is dissolved in 10wt% ethanol and brushed onto the flesh side of the leather blank for 0.5 minutes. Finally, it is dried at a low temperature of 50℃ using microwave to obtain high-quality leather.

[0071] The leather was measured to have a softness of 8.2 mm and a tear strength of 58.7 N / mm.

[0072] Example 4

[0073] Softened raw hides were used as raw materials and hung to dry to obtain hide blanks with a moisture content of 40 wt%. Tween and ethanol were mixed at 0.1 wt% of the weight of the softened raw hides and the mixed solution was used to soak the raw hides for 60 min. After extrusion, hide blanks soaked in Tween and ethanol were obtained. 10 wt% of n-hexylmethyldichlorosilane was dissolved in 10 wt% ethanol and then rolled onto the flesh side of the hide blanks for 30 min. Finally, the hides were hung to dry at a low temperature of 35°C to obtain high-quality leather.

[0074] The leather was measured to have a softness of 8.0 mm and a tear strength of 85.4 N / mm.

[0075] Example 5

[0076] Using zirconium-tanned leather as raw material, it is nailed and dried to obtain a leather blank with a moisture content of 21 wt%. Tween and ethanol, based on 1 wt% of the weight of zirconium-tanned leather, are mixed and the Tween and ethanol mixture is used to impregnate the tanned leather for 5 min. After extrusion, a leather blank impregnated with Tween and ethanol is obtained. 10 wt% of dodecyl (methyl)dimethoxysilane is dissolved in 30 wt% ethanol and sprayed onto the flesh side of the leather blank for 0.5 min. Finally, it is dried at a low temperature of 20°C using infrared light to obtain high-quality leather.

[0077] The leather was measured to have a softness of 8.6 mm and a tear strength of 81.2 N / mm.

[0078] Example 6

[0079] Dyed raw leather was dried on a board to obtain a leather blank with a moisture content of 30 wt%. Tween and ethanol were mixed at 0.5 wt% of the weight of the dyed raw leather and the mixture was used to soak the raw leather for 60 min. After extrusion, leather blank soaked in Tween and ethanol was obtained. 18 wt% of octadecyltrichlorosilane was dissolved in 18 wt% ethanol and brushed onto the flesh side of the leather blank for 30 min. Finally, it was dried at a low temperature of 50℃ using microwave to obtain high-quality leather.

[0080] The leather was measured to have a softness of 9.0 mm and a tear strength of 56.6 N / mm.

[0081] Example 7

[0082] Using acid-treated raw hides as raw materials, the hides are hung-dried to obtain hide blanks with a moisture content of 40 wt%. Tween and ethanol are mixed at 0.1 wt% of the weight of the acid-treated raw hides and 200 wt% of the mixture. The mixture is used to soak the raw hides for 120 min. After extrusion, hide blanks soaked in Tween and ethanol are obtained. 18 wt% of dodecyltrimethoxysilane is dissolved in 90 wt% ethanol and sprayed onto the flesh side of the hide blanks for 60 min. Finally, the hides are hung-dried at a low temperature of 35°C to obtain high-quality leather.

[0083] The leather was measured to have a softness of 8.8 mm and a tear strength of 83.6 N / mm.

[0084] Example 8

[0085] Using zeolite-tanned leather as raw material, it is stretched and dried to obtain a leather blank with a moisture content of 21wt%. Tween and ethanol, based on the weight of the zeolite-tanned leather, are mixed and the Tween and ethanol mixture is used to impregnate the tanned leather for 60 minutes. After extrusion, a leather blank impregnated with Tween and ethanol is obtained. 2wt% of octadecyl (dimethyl)methoxysilane is dissolved in 10wt% ethanol and then rolled onto the flesh side of the leather blank for 0.5 minutes. Finally, it is hung to dry at low temperature at 50℃ and then dried with infrared light to obtain high-quality leather.

[0086] The leather was measured to have a softness of 8.5 mm and a tear strength of 51.2 N / mm.

[0087] Example 9

[0088] Using fat-reinforced raw leather as raw material, it is hung to dry and stretched to obtain a leather blank with a moisture content of 30wt%. Tween and ethanol are mixed at 1wt% of the weight of the fat-reinforced raw leather and the mixed solution is used to soak the raw leather for 60 min. After extrusion, a leather blank soaked in Tween and ethanol is obtained. 10wt% of octadecyltriethoxysilane is dissolved in 50wt% ethanol and applied to the flesh side of the leather blank by rotating it in a drum for 30 min. Finally, it is hung to dry at a low temperature of 35℃ and microwave dried to obtain high-quality leather.

[0089] The leather was measured to have a softness of 9.1 mm and a tear strength of 54.7 N / mm.

[0090] Example 10

[0091] Using raw hides obtained through an acid immersion-deacidification process, the hides are hung to dry, resulting in hide blanks with a moisture content of 40 wt%. A mixture of 0.1 wt% Tween and 200 wt% ethanol based on the weight of the raw hides is applied to the hides for 120 min. After extrusion, hide blanks soaked in Tween and ethanol are obtained. 18 wt% dodecyltrimethoxysilane is dissolved in 90 wt% ethanol and sprayed onto the flesh side of the hide blanks for 60 min. Finally, the hides are hung to dry at a low temperature of 20°C to obtain high-quality leather.

[0092] The leather was measured to have a softness of 8.4 mm and a tear strength of 83.5 N / mm.

[0093] Example 11

[0094] Using polymetallic tanning agents as raw material, the leather is vacuum-dried and stretched to obtain a leather blank with a moisture content of 30 wt%. 0.5 wt% of Tween and 120 wt% of ethanol based on the weight of the polymetallic tanning agent are mixed and the Tween-ethanol mixture is used to impregnate the tanned leather for 5 min. After extrusion, a leather blank impregnated with Tween and ethanol is obtained. 2 wt% of dodecyltrichlorosilane is dissolved in 10 wt% ethanol and brushed onto the flesh side of the leather blank for 0.5 min. Finally, it is hung to dry at 50°C and microwave-dried to obtain high-quality leather.

[0095] The leather was measured to have a softness of 8.3 mm and a tear strength of 76.4 N / mm.

[0096] Example 12

[0097] Using retanned and fatliquored raw leather as raw material, the leather is hung to dry and then dried on a board to obtain a leather blank with a moisture content of 21 wt%. Tween and ethanol are mixed at 1 wt% of the weight of the raw leather and the mixture is used to soak the raw leather for 60 min. After extrusion, a leather blank soaked in Tween and ethanol is obtained. 10 wt% of n-hexyltrimethoxysilane is dissolved in 30 wt% ethanol and sprayed onto the flesh side of the leather blank for 30 min. Finally, the leather blank is hung to dry at a low temperature of 35℃ and then dried with infrared light to obtain high-quality leather.

[0098] The leather was measured to have a softness of 8.9 mm and a tear strength of 52.7 N / mm.

[0099] Example 13

[0100] Vegetable-tanned leather was used as raw material and subjected to hanging, vacuum, and sheet drying to obtain a leather blank with a moisture content of 30 wt%. Tween and ethanol were mixed at 0.1 wt% of the weight of the vegetable-tanned leather and 50 wt% of the mixture. The mixture was used to impregnate the tanned leather for 5 min. After extrusion, a leather blank impregnated with Tween and ethanol was obtained. 18 wt% of n-hexyltriethoxysilane was dissolved in 54 wt% ethanol and brushed onto the flesh side of the leather blank for 60 min. Finally, it was dried at a low temperature of 20°C using microwave to obtain high-quality leather.

[0101] The leather was measured to have a softness of 8.1 mm and a tear strength of 50.1 N / mm.

[0102] Example 14

[0103] Using retanned and dyed raw leather as raw material, the leather is hung to dry, vacuum dried, and nailed to obtain a leather blank with a moisture content of 21 wt%. Tween and ethanol are mixed at 0.5 wt% of the weight of the raw leather and the mixture is used to soak the raw leather for 120 min. After extrusion, a leather blank soaked in Tween and ethanol is obtained. 2 wt% of dodecyl (methyl)diethoxysilane is dissolved in 10 wt% ethanol and then rolled onto the flesh side of the leather blank for 0.5 min. Finally, it is dried at 35°C using low-temperature infrared light to obtain high-quality leather.

[0104] The leather was measured to have a softness of 8.4 mm and a tear strength of 55.2 N / mm.

[0105] Example 15

[0106] Aldehyde-tanned leather was vacuum dried to obtain a leather blank with a moisture content of 40 wt%. Tween and ethanol, based on 1 wt% of the weight of the aldehyde-tanned leather, were mixed and the mixture was used to impregnate the tanned leather for 60 min. After extrusion, a leather blank impregnated with Tween and ethanol was obtained. 10 wt% of dodecyltriethoxysilane was dissolved in 50 wt% ethanol and applied to the flesh side of the leather blank by rotating it in a drum for 30 min. Finally, it was dried at a low temperature of 50°C using microwave to obtain high-quality leather.

[0107] The leather was measured to have a softness of 8.5 mm and a tear strength of 63.9 N / mm.

[0108] Example 16

[0109] Using retanned, dyed, and fatliquored raw leather as raw material, vacuum drying was performed to obtain a leather blank with a moisture content of 21 wt%. Tween and ethanol were mixed at 0.1 wt% of the raw leather weight and 200 wt% of the mixture. The Tween and ethanol mixture was used to impregnate the raw leather for 5 min. After extrusion, a leather blank impregnated with Tween and ethanol was obtained. 10 wt% of dodecyltrimethoxysilane was dissolved in 30 wt% ethanol and sprayed onto the flesh side of the leather blank for 0.5 min. Finally, the leather blank was hung to dry at a low temperature of 30°C to obtain high-quality leather.

[0110] The leather was measured to have a softness of 8.8 mm and a tear strength of 53.8 N / mm.

[0111] Example 17

[0112] Using phenolic synthetic tanning agents to tan leather as raw material, the leather is hung to dry and then vacuum dried to obtain a leather blank with a moisture content of 30 wt%. 1 wt% of Tween and 120 wt% of ethanol based on the weight of the phenolic synthetic tanning agent are mixed and the Tween-ethanol mixture is used to impregnate the tanned leather for 60 min. After extrusion, a leather blank impregnated with Tween and ethanol is obtained. 10 wt% of active chlorinated tanning silane is dissolved in 50 wt% ethanol and then roller-coated onto the flesh side of the leather blank for 30 min. Finally, it is dried at 30℃ using low-temperature infrared light to obtain high-quality leather.

[0113] The leather was measured to have a softness of 8.6 mm and a tear strength of 54.2 N / mm.

[0114] Example 18

[0115] Using chlorinated leather as raw material, the leather is hung and dried on boards to obtain a leather blank with a moisture content of 21 wt%. Tween and ethanol, based on the weight of the chlorinated leather, are mixed at 0.5 wt% and 50 wt% respectively. The mixture of Tween and ethanol is used to impregnate the tanned leather for 120 min. After extrusion, a leather blank impregnated with Tween and ethanol is obtained. 18 wt% of octadecyltrimethoxysilane is dissolved in 54 wt% ethanol and brushed onto the flesh side of the leather blank for 30 min. Finally, the leather is hung and dried at a low temperature of 50°C to obtain high-quality leather.

[0116] The leather was measured to have a softness of 8.9 mm and a tear strength of 67.5 N / mm.

[0117] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A high-quality leather-making method with an ultra-short process, characterized in that: Using bare hide, tanned leather, or raw leather as raw materials, the raw materials are pre-dried to a moisture content of 21wt%-40wt%, then impregnated with an ethanol solution containing Tween, extruded, treated with a long-chain silane coupling agent, and finally dried at low temperature. Specifically, based on the weight of the raw materials, the amount of Tween added is 0.1wt%-1wt%, and the amount of ethanol added is 50wt%-200wt%. The long-chain silane coupling agent is C. n H 2n+1 (CH3) 3-m SiX m n is an integer between 6 and 18, and X is a group that can be hydrolyzed into silanol.

2. The ultra-short process high-quality leather tanning method as described in claim 1, characterized in that, X includes any one of chlorine, methoxy, and ethoxy groups.

3. The ultra-short process high-quality leather tanning method as described in claim 1 or 2, characterized in that, The amount of the long-chain silane coupling agent added is 2wt%-18wt% of the raw material weight.

4. The ultra-short process high-quality leather tanning method as described in claim 1, characterized in that, The temperature for the low-temperature drying is 20-50 °C.

5. The ultra-short process high-quality leather tanning method as described in claim 1, characterized in that, The bare skin includes any one of delimed bare skin, softened bare skin, pickled bare skin, and bare skin obtained through a pickling-deacidification process.

6. The ultra-short process high-quality leather tanning method as described in claim 1, characterized in that, The tanned leather includes any one of chrome tanned leather, aluminum tanned leather, zircon tanned leather, zeolite tanned leather, multi-metal tanning agent tanned leather, vegetable tanned leather, aldehyde tanned leather, phenolic synthetic tanning agent tanned leather, and active chlorine tanned leather.

7. The ultra-short process high-quality leather tanning method as described in claim 1, characterized in that, The raw leather is obtained by performing at least one of the processes of retanning, dyeing, and fatliquoring.

8. The ultra-short process high-quality leather tanning method as described in claim 1, characterized in that, The pre-dried raw materials were soaked in an ethanol solution containing Tween for 5-120 minutes.

9. The ultra-short process high-quality leather tanning method as described in claim 1, characterized in that, The method of using long-chain silane coupling agent is as follows: apply the ethanol solution of long-chain silane coupling agent to the surface of the skin blank for 0.5-60 minutes by rotating a drum, brushing, rolling, or spraying.

10. Leather produced using the ultra-short process high-quality leather tanning method as described in any one of claims 1-9.