Dermis coating method, dermis preparation method, low-odor low-formaldehyde low-carbon chromium-free dermis and application thereof

Abstract

The invention discloses a dermis coating method, a dermis preparation method, low-odor low-formaldehyde low-carbon chromium-free dermis and application of the low-odor low-formaldehyde low-carbon chromium-free dermis. The dermis preparation method comprises the following steps: carrying out roller coating on the surface of dermis by adopting the pomelo peel extract and the formaldehyde removing agent, and tanning the dermis by adopting the gallnut plant extract, the natural zeolite and the soybean lecithin fatliquor. The pomelo peel extract is introduced in the dermis preparation process, and the formaldehyde removing agent is used as a part of the coating process, so that the odor characteristic and formaldehyde emission of the dermis can be remarkably improved. A vegetable tanning process is used for replacing a traditional chrome tanning process, raw materials in a bio-based tanning agent and a bio-based fatliquor have renewability and biodegradability, consumption of limited petroleum resources is effectively reduced, and the problem that heavy metal chromium is left in leather products is solved.

Description

Technical Field

[0001] This application relates to the technical field of genuine leather materials and their production technologies, and specifically relates to a genuine leather finishing method, a genuine leather preparation method, a low-odor, low-formaldehyde, low-carbon, chromium-free genuine leather, and its applications. Background Art

[0002] As a material made from animal hides through physical and chemical processing techniques such as hair removal and tanning, genuine leather is widely loved by consumers for its excellent moisture absorption, comfort, and sensory advantages compared to artificial leather, especially in the fields of automotive seats and interiors. However, due to the natural properties of genuine leather and the complex processing process, its odor problem has not been effectively controlled, and existing genuine leather is difficult to meet the high standards of in-vehicle air quality in the market. In addition, traditional genuine leather processing methods have deficiencies in the environmental friendliness of raw materials and the residual heavy metal chromium, which have a negative impact on the living environment and user health.

[0003] In view of this, it has become particularly urgent to develop a healthy and environmentally friendly genuine leather technology with low odor, low formaldehyde, low carbon, and no residual heavy metal chromium. Summary of the Invention

[0004] This application aims to solve at least one of the technical problems in the related technologies to some extent. For this purpose, one object of this application is to provide a genuine leather finishing method, a genuine leather preparation method, a low-odor, low-formaldehyde genuine leather, or a low-odor, low-formaldehyde, low-carbon, chromium-free genuine leather, and its applications. By using the genuine leather finishing method of this application, the odor and formaldehyde in the genuine leather can be adsorbed and neutralized, thereby significantly improving the in-vehicle air quality. At the same time, the traditional chrome tanning process is replaced with a vegetable tanning process, and the raw materials in the bio-based tanning agent and bio-based fatliquor have renewable and biodegradable properties, effectively reducing the consumption of limited petroleum resources and solving the problem of residual heavy metal chromium in genuine leather products.

[0005] In the first aspect of this application, a genuine leather finishing method is proposed. According to an embodiment of this application, the method includes: roll-coating the surface of the genuine leather with pomelo peel extract and a formaldehyde remover.

[0006] The inventors of the present application have found through a large number of experiments that introducing pomelo peel extract and formaldehyde remover as part of the finishing process during the preparation of genuine leather can significantly improve the odor characteristics and formaldehyde emission of genuine leather. Specifically, the pomelo peel extract can be fully absorbed by the genuine leather, effectively adsorb and reduce the odor groups in the genuine leather, thereby reducing the odor of the finished product. Among them, the white pulp of the pomelo peel is a multi-layered soft spongy tissue with a unique nanostructure and a large number of micropores, which makes it an efficient adsorbent that can capture and reduce the odor molecules in the genuine leather, thus reducing the odor; in addition, the pomelo peel contains various volatile oil substances such as naringin and neohesperidin, which can not only release aromas but also neutralize the unpleasant odors in the genuine leather to a certain extent, improving the comfort. The main component of the formaldehyde remover is an organic substance containing amino groups that combines to form a resin, and its reaction principle is to use the reaction between aldehydes and amino groups to block the carbonyl group, thereby reducing the release amount of aldehydes, and thus achieving the effect of reducing the release amount of aldehydes and reducing the odor.

[0007] According to an embodiment of the present application, the genuine leather finishing method may further include at least one of the following additional technical features:

[0008] According to an embodiment of the present application, first roll-coat the surface of the genuine leather with the pomelo peel extract, and then roll-coat the formaldehyde remover on the surface of the genuine leather coated with the pomelo peel extract.

[0009] According to an embodiment of the present application, before roll-coating the surface of the genuine leather with the pomelo peel extract, it further includes: roll-coating a filling resin on the surface of the genuine leather; roll-coating a first scratch repair paste on the surface of the genuine leather after roll-coating the filling resin.

[0010] According to an embodiment of the present application, after roll-coating the formaldehyde remover on the surface of the genuine leather coated with the pomelo peel extract, it further includes: roll-coating a second scratch repair paste on the surface of the genuine leather after roll-coating the formaldehyde remover; roll-coating a base coat resin on the surface of the genuine leather coated with the second scratch repair paste.

[0011] According to an embodiment of the present application, the coating dosage of the pomelo peel extract is 2 - 4 g / sf 2 。

[0012] According to an embodiment of the present application, the coating dosage of the filling resin is 15 - 20 g / sf 2 。

[0013] According to an embodiment of the present application, the coating dosage of the first scratch repair paste is 3 - 5 g / sf 2 。

[0014] According to an embodiment of the present application, the coating dosage of the formaldehyde remover is 2 - 4 g / sf 2 。

[0015] According to an embodiment of the present application, the coating dosage of the second scratch repair paste is 2 - 4 g / sf 2 .

[0016] According to an embodiment of the present application, the coating dosage of the base coat resin is 8 - 12 g / sf 2 .

[0017] According to an embodiment of the present application, the pomelo peel extract is prepared by the following method: the pomelo peel is subjected to a first drying treatment to obtain dried pomelo peel; the dried pomelo peel is mixed with a modifying reagent to obtain modified pomelo peel; the modified pomelo peel is ground with water to obtain a paste-like modified pomelo peel; the paste-like modified pomelo peel is subjected to a second drying treatment to obtain the pomelo peel extract.

[0018] According to an embodiment of the present application, the filling resin includes at least one of acrylic acid, methacrylic acid and their derivative polymers.

[0019] According to an embodiment of the present application, the base coat resin is a polyurethane resin.

[0020] In a second aspect of the present application, the present application proposes a method for preparing genuine leather. According to an embodiment of the present application, the method includes: performing retanning treatment and coating treatment on the to-be-treated genuine leather after preliminary tanning to obtain the genuine leather; wherein, the coating treatment is carried out by using the genuine leather coating method described in the first aspect; the preliminary tanning is carried out by using a bio-based tanning agent; the retanning treatment is carried out by using a bio-based tanning agent and a bio-based fatliquor.

[0021] The method for preparing genuine leather of the present application effectively improves the odor and formaldehyde emission of genuine leather and obtains low-odor, low-formaldehyde, low-carbon and chromium-free genuine leather products by using pomelo peel extract, formaldehyde scavenger and bio-vegetable tanning process. On the one hand, the nanostructure of pomelo peel can adsorb odor molecules, thus reducing the peculiar smell in the finished genuine leather; at the same time, the volatile oil substances such as naringin and neohesperidin released by it can emit a fresh fragrance and neutralize the bad smell. On the other hand, the main component of the formaldehyde scavenger is an organic substance containing amino groups that combines to form a resin, and its reaction principle is to use the reaction between aldehydes and amino groups to block the carbonyl group, thereby reducing the release amount of aldehydes, so as to achieve the effect of reducing the release amount of aldehydes and lowering the value. In addition, using renewable plant resources such as pomelo peel, soy lecithin and Chinese gallnut to replace traditional fossil and its derivative materials not only reduces the overall carbon footprint, reduces the dependence on limited petroleum resources and environmental pollution, but also solves the problem of heavy metal chromium residue in traditional chromium tanning process.

[0022] According to an embodiment of the present application, the preparation method may further include at least one of the following additional technical features:

[0023] According to an embodiment of the present application, the retanning treatment includes: retanning the preliminarily tanned leather with a bio-based tanning agent and a bio-based fatliquor.

[0024] According to an embodiment of the present application, the bio-based tanning agent includes Chinese gallnut, ethanol, methanol, glycerol, and water.

[0025] According to an embodiment of the present application, the bio-based fatliquor includes soy lecithin, amino silicone oil, non-ionic surfactant, preservative, natural antibacterial agent, and water.

[0026] According to an embodiment of the present application, the mass ratio of the Chinese gallnut, the ethanol, the methanol, the glycerol, and the water is (45 - 55):(25 - 35):(5 - 15):(3 - 7):(3 - 7).

[0027] According to an embodiment of the present application, the mass ratio of the soy lecithin, the amino silicone oil, the non-ionic surfactant, the preservative, the natural antibacterial agent, and the water is (10 - 20):(1 - 3):(1 - 3):(0.0005 - 0.001):(0.0005 - 0.001):(70 - 85).

[0028] In the third aspect of the present application, the present application provides a low-odor, low-formaldehyde or low-odor, low-formaldehyde, low-carbon, chromium-free genuine leather product. According to an embodiment of the present application, the genuine leather product is finished by the genuine leather finishing method described in the first aspect for the leather to be treated to obtain the low-odor, low-formaldehyde genuine leather; or, the low-odor, low-formaldehyde, low-carbon, chromium-free genuine leather product is prepared by the preparation method described in the second aspect. Thus, the genuine leather of the present application has low odor, low formaldehyde, low carbon, and no heavy metal chromium residue, and can effectively improve the comfort, health, and environmental protection performance of genuine leather products. Those skilled in the art can understand that this genuine leather product has all the features and advantages of the aforementioned genuine leather finishing method, and will not be elaborated herein.

[0029] In the fourth aspect of the present application, the present application provides an application of the low-odor, low-formaldehyde genuine leather or low-odor, low-formaldehyde, low-carbon, chromium-free genuine leather described in the third aspect in automotive interiors.

[0030] The additional aspects and advantages of the present application will be partly given in the following description, partly become obvious from the following description, or be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and / or additional aspects and advantages of the present application will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0032] Figure 1Shows a schematic flowchart of the process for preparing dermis according to an embodiment of the present application. Detailed implementation manners

[0033] The embodiments of the present application will be described in detail below. The embodiments described below are exemplary and are only used to explain the present application, and should not be construed as a limitation to the present application.

[0034] Referring to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appearing at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0035] For the sake of brevity, only some numerical ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form a range not explicitly recited; and any lower limit can be combined with other lower limits to form a range not explicitly recited, and similarly any upper limit can be combined with any other upper limit to form a range not explicitly recited. In addition, each individually disclosed point or single numerical value itself can be used as a lower limit or an upper limit and combined with any other point or single numerical value or combined with other lower limits or upper limits to form a range not explicitly recited.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0037] It should be noted that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Further, in the description of this application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0038] In this application, the term "comprising" or "including" is an open expression, that is, it includes the content specified in this application, but does not exclude other aspects.

[0039] If there is no special description, all embodiments and optional embodiments of this application can be combined with each other to form a new technical solution.

[0040] With the rapid development of my country's automobile industry, consumers have higher requirements for the comfort, luxury and sensory experience of automobiles. In order to meet these needs, automobile manufacturers continue to enhance the airtightness of the car compartment and increase the soft covering fabrics of automobile interior parts. However, these improvement measures also bring side effects: the space in the car compartment is relatively small, and air pollutants are more likely to accumulate, resulting in increasingly prominent problems of air quality and odor in the car; the large-scale use of fossil raw materials and chemical additives is not conducive to low-carbon emission reduction, and there is a risk of heavy metal pollution. The above has become a common challenge faced by the industry and has attracted widespread attention from the whole society and consumers. As the fabric of interior parts such as car seats, leather has particularly prominent problems with odor, formaldehyde, carbon emissions and heavy metal residues. Therefore, how to effectively reduce the odor, formaldehyde, carbon emissions and heavy metal residues of leather fabrics has become one of the key issues that the automotive industry needs to solve urgently.

[0041] In view of this, the present application optimizes the tanning process and the finishing process in the traditional leather preparation process. During the experiment, the inventor found that by introducing gallnut tannin extract in the preliminary tanning process, introducing gallnut tannin extract and soy lecithin fatliquor in the retanning process, and introducing grapefruit peel extract and formaldehyde remover in the finishing process, the odor, formaldehyde, carbon emissions and heavy metal chromium residues of the leather fabric can be effectively reduced, thereby improving the comfort, health and environmental protection performance of the leather fabric. This method uses the vegetable tanning process of gallnut tannin extract and soy lecithin fatliquor to replace the traditional chrome tanning process, and uses the natural adsorption characteristics of grapefruit peel extract and formaldehyde remover to neutralize free formaldehyde, and finally obtains low-odor, low-formaldehyde, low-carbon and chrome-free leather fabrics. The leather finishing method, the leather preparation method, low-odor and low-formaldehyde leather or low-odor, low-formaldehyde, low-carbon and chrome-free leather and its application will be introduced in detail below.

[0042] Leather finishing methods

[0043] The present application proposes a method for finishing leather. According to an embodiment of the present application, the method comprises: using grapefruit peel extract and formaldehyde remover to roll-coat the leather surface.

[0044] The inventors of the present application have found through a large number of experiments that introducing pomelo peel extract and formaldehyde scavenger as part of the finishing process during the preparation of genuine leather can significantly improve the odor and formaldehyde emission of genuine leather. Specifically, the pomelo peel extract can be fully absorbed by the genuine leather, effectively adsorb and reduce the odor groups in the genuine leather, thereby reducing the odor of the finished product. Among them, the white pulp of the pomelo peel is a multi-layered soft spongy tissue with a unique nanostructure and a large number of micropores, which makes it an efficient adsorbent that can capture and reduce the odor molecules in the genuine leather, thereby reducing the odor; in addition, the pomelo peel contains various volatile oil substances such as naringin and neohesperidin, which can not only release aromas, but also neutralize the unpleasant odors in the genuine leather to a certain extent, improving the comfort. The main component of the formaldehyde scavenger is an organic substance containing amino groups that combines to form a resin, and its reaction principle is to use the reaction between aldehydes and amino groups to block the carbonyl group, thereby reducing the release amount of aldehydes and achieving the effect of reducing the release amount of aldehydes and reducing the odor.

[0045] In some embodiments of the present application, referring to Figure 1 , before roller-coating the surface of the genuine leather with pomelo peel extract in step S300, it further includes:

[0046] S100: Roller-coating a filling resin on the surface of the genuine leather

[0047] In some embodiments of the present application, the coating dosage of the filling resin is 15 - 20 g / sf 2 . For example, it can be 15 g / sf 2 , 16 g / sf 2 , 17 g / sf 2 , 18 g / sf 2 , 19 g / sf 2 , 20 g / sf 2 etc., or it can be a range composed of any of the above numerical values.

[0048] Thus, by first roller-coating a filling resin on the surface of the genuine leather, a uniform resin coating can be provided on the surface of the genuine leather, which not only helps to improve the appearance and feel of the genuine leather, making it smoother and more uniform, but also can enhance the abrasion resistance and durability of the genuine leather, reduce the wear of the genuine leather during daily use, and extend the service life of the genuine leather.

[0049] In some embodiments of the present application, the filling resin is a polyurethane resin. Thus, the above-mentioned types of filling resins can improve the appearance and feel of the genuine leather, enhance the abrasion resistance and durability of the genuine leather, reduce the wear of the genuine leather during daily use, and extend the service life of the genuine leather.

[0050] In some embodiments of the present application, after roll-coating the filling resin on the surface of the genuine leather, it further includes stretching and drying the genuine leather with the filling resin on the surface, so that the moisture content of the genuine leather with the filling resin on the surface is 6-9%.

[0051] S200: Roll-coat the first scratch repair paste on the surface of the genuine leather after roll-coating the filling resin

[0052] In some embodiments of the present application, the coating dosage of the first scratch repair paste is 3-5 g / sf 2 . For example, it can be 3 g / sf 2 , 3.5 g / sf 2 , 4 g / sf 2 , 4.5 g / sf 2 , 5 g / sf 2 etc., or can be a range composed of any of the above numerical values.

[0053] Thus, by roll-coating the first scratch repair paste on the surface of the genuine leather after roll-coating the filling resin, it can further fill the tiny defects and unevenness that the filling resin may not completely cover, and at the same time repair various defects that may appear on the surface of the genuine leather, such as scratches, cracks, holes, etc., so as to improve the overall appearance of the genuine leather, enhance the durability and anti-damage ability of the genuine leather, and extend the service life of the genuine leather.

[0054] In some embodiments of the present application, the specific type of the first scratch repair paste is not specifically limited as long as it can repair the defects on the surface of the genuine leather, and it can be a commodity commonly used in the art. Exemplarily, the first scratch repair paste is roll repair scratch repair paste CS. Thus, it can repair various defects that may appear on the surface of the genuine leather, improve the overall appearance of the genuine leather, enhance the durability and anti-damage ability of the genuine leather, and extend the service life of the genuine leather.

[0055] In some embodiments of the present application, after roll-coating the first scratch repair paste on the surface of the genuine leather after roll-coating the filling resin, it further includes buffing the genuine leather with the first scratch repair paste on the surface. According to the embodiments of the present application, the buffing treatment includes: first buffing with an abrasive of 280-400 mesh, and then buffing with an abrasive of 400-600 mesh.

[0056] In some embodiments of the present application, referring to Figure 1 , after roll-coating the surface of the genuine leather with pomelo peel extract in S300, it further includes:

[0057] S400: Roll-coat the deodorant on the surface of the genuine leather after roll-coating the pomelo peel extract

[0058] In some embodiments of the present application, the coating dosage of the deodorant is 2-4 g / sf 2 . For example, it can be 2 g / sf2 、2.5 g / sf 2 、3 g / sf 2 、3.5 g / sf 2 、4 g / sf 2 and so on, or can be a range composed of any of the above values.

[0059] Thus, by roll-coating the aldehyde removal agent on the surface of the dermis after roll-coating the pomelo peel extract, the formaldehyde that may exist in the dermis can be neutralized or decomposed, reducing formaldehyde release and improving the safety of the dermis product and the air quality in the vehicle.

[0060] It should be noted that the surface of the dermis is divided into the front and the back. The front of the dermis is relatively smooth, and the back is relatively rough. During the finishing process, except that the aldehyde removal agent is roll-coated on the back of the dermis, the rest of the components are roll-coated on the front of the dermis.

[0061] In some embodiments of the present application, the specific type of the aldehyde removal agent is not specifically limited as long as it can absorb harmful substances. It can be a commercially available product commonly used in the art. Exemplarily, the aldehyde removal agent is a polymer-based aldehyde removal agent, a bioenzyme-based aldehyde removal agent, a plant extract-based aldehyde removal agent, etc., and specifically can be the aldehyde removal agent Q-200. Thus, the aldehyde removal agents of the above types can reduce the release of harmful substances such as free formaldehyde, improve the air quality, enhance the environmental protection performance of the dermis product, and meet the requirements of environmental protection regulations and consumers for healthy products.

[0062] In some embodiments of the present application, after roll-coating the aldehyde removal agent on the surface of the dermis after roll-coating the pomelo peel extract, it further includes: ironing the dermis with the aldehyde removal agent on its surface. According to the embodiments of the present application, the temperature of the ironing treatment is 85-95 °C. For example, it can be 85 °C, 87 °C, 90 °C, 92 °C, 95 °C, etc., or can be a range composed of any of the above values. According to the embodiments of the present application, the pressure of the ironing treatment is 30-50 kg / cm 2 . For example, it can be 30 kg / cm 2 、35 kg / cm 2 、40 kg / cm 2 、45 kg / cm 2 、50 kg / cm 2 and so on, or can be a range composed of any of the above values.

[0063] S500: Roll-coat the second scratch repair paste on the surface of the dermis after roll-coating the aldehyde removal agent

[0064] In some embodiments of the present application, the coating dosage of the second scratch repair paste is 2-4 g / sf 2 . For example, it can be 2 g / sf 2 、2.5 g / sf2 、3 g / sf 2 、3.5 g / sf 2 、4 g / sf 2 etc., or can be a range composed of any of the above values.

[0065] Thus, by roll-coating the second scratch repair paste on the surface of the genuine leather after roll-coating the formaldehyde-removing agent, the marks or slight unevenness left by the formaldehyde-removing agent on the leather surface can be repaired, the uniformity and smoothness of the genuine leather surface can be restored, and at the same time, the wear resistance, water resistance, and anti-pollution performance of the genuine leather can be enhanced.

[0066] In some embodiments of the present application, the specific type of the second scratch repair paste is not specifically limited as long as it can repair the defects on the surface of the genuine leather, and it can be a commodity commonly used in the art. Exemplarily, the second scratch repair paste is a roll-compensating scratch repair paste, specifically CT532. Thus, various defects that may appear on the surface of the genuine leather can be repaired, the overall appearance of the genuine leather can be improved, and the durability and anti-damage ability of the genuine leather can be enhanced, thereby extending the service life of the genuine leather.

[0067] S600: Roll-coat the base coat resin on the surface of the genuine leather roll-coated with the second scratch repair paste

[0068] In some embodiments of the present application, the coating dosage of the base coat resin is 8 - 12 g / sf 2 . For example, it can be 8 g / sf 2 、9 g / sf 2 、10 g / sf 2 、11 g / sf 2 、12 g / sf 2 etc., or can be a range composed of any of the above values.

[0069] Thus, by roll-coating the base coat resin on the surface of the genuine leather roll-coated with the second scratch repair paste, a sealing layer can be formed on the leather surface to protect the leather from moisture, stains, and other external environments, enhance the wear resistance of the leather, and extend its service life.

[0070] In some embodiments of the present application, the base coat resin is a polyurethane resin. Thus, the above-mentioned type of base coat resin can form a sealing layer on the leather surface to protect the leather from moisture, stains, and other external environments.

[0071] In some embodiments of the present application, refer to Figure 1, after successively roll-coating the filling resin and the first scratch repair paste on the surface of the dermis, and then successively roll-coating the pomelo peel extract, the formaldehyde removing agent, the second scratch repair paste and the base coating resin, the pomelo peel extract and the formaldehyde removing agent can give full play to their functions. On the one hand, it can penetrate more effectively into the dermis, adsorb the odor groups and free formaldehyde in the dermis, and at the same time can also adsorb the odor groups and free formaldehyde that the filling resin and the first scratch repair paste may emit; on the other hand, it can neutralize the odor groups and free formaldehyde that the second scratch repair paste and the base coating resin may contain, so as to minimize the emission of odor and formaldehyde and ensure that the final product has better low-odor and low-formaldehyde performance.

[0072] In some embodiments of the present application, the coating dosages of the pomelo peel extract and the formaldehyde removing agent are respectively 2-4 g / sf 2 . For example, it can be 2 g / sf 2 , 2.5 g / sf 2 , 3 g / sf 2 , 3.5 g / sf 2 , 4 g / sf 2 and so on, or can be a range composed of any of the above values. Thus, the pomelo peel extract and the formaldehyde removing agent can give full play to their functions, reduce the emission of odor and formaldehyde, and improve the comfort of the dermis.

[0073] In some embodiments of the present application, the pomelo peel extract is prepared by the following method: the pomelo peel is subjected to a first drying treatment to obtain dried pomelo peel; the dried pomelo peel is mixed with a modifying reagent to obtain modified pomelo peel; the modified pomelo peel is ground with water to obtain a paste-like modified pomelo peel; the paste-like modified pomelo peel is subjected to a second drying treatment to obtain the pomelo peel extract.

[0074] In some embodiments of the present application, the modifying reagent includes at least one of dilute hydrochloric acid, dilute sulfuric acid, isopropanol, hydrogen peroxide, dilute phosphoric acid, and ethanol.

[0075] In some embodiments of the present application, the mass fraction of the modifying reagent is 5-50%. For example, it can be 5%, 10%, 20%, 30%, 40%, 50% and so on, or can be a range composed of any of the above values.

[0076] In some embodiments of the present application, the mass-volume ratio of the dried pomelo peel to the modifying reagent is (5-15) g:100 mL. For example, it can be 5 g:100 mL, 7 g:100 mL, 10 g:100 mL, 12 g:100 mL, 15 g:100 mL and so on, or can be a range composed of any of the above values.

[0077] In some embodiments of the present application, the concentration of the modified pomelo peel in water is (1-15) g / 100 mL. For example, it can be 1 g / 100 mL, 2 g / 100 mL, 2.5 g / 100 mL, 5 g / 100 mL, 8 g / 100 mL, 10 g / 100 mL, 15 g / 100 mL, etc., or it can be a range composed of any of the above values.

[0078] In some embodiments of the present application, before grinding the modified pomelo peel with water, it further includes: after washing the modified pomelo peel with water, performing a third drying treatment. According to the embodiments of the present application, the temperature of the third drying treatment is 55-65 °C. For example, it can be 55 °C, 57 °C, 60 °C, 62 °C, 65 °C, etc., or it can be a range composed of any of the above values. According to the embodiments of the present application, the time of the third drying treatment is 20-30 h. For example, it can be 20 h, 22 h, 24 h, 26 h, 28 h, 30 h, etc., or it can be a range composed of any of the above values.

[0079] In some embodiments of the present application, after performing the second drying treatment on the paste-like modified pomelo peel, it further includes: performing a sieving treatment on the paste-like modified pomelo peel after the second drying treatment. According to the embodiments of the present application, the mesh number of the sieve is 45-55 meshes. For example, it can be 45 meshes, 47 meshes, 50 meshes, 52 meshes, 55 meshes, etc., or it can be a range composed of any of the above values.

[0080] In some embodiments of the present application, the temperature of the first drying treatment is 55-65 °C. For example, it can be 55 °C, 57 °C, 60 °C, 62 °C, 65 °C, etc., or it can be a range composed of any of the above values. According to the embodiments of the present application, the time of the first drying treatment is 20-30 h. For example, it can be 20 h, 22 h, 24 h, 26 h, 28 h, 30 h, etc., or it can be a range composed of any of the above values.

[0081] In some embodiments of the present application, the temperature of the second drying treatment is 70-90 °C. For example, it can be 70 °C, 72 °C, 75 °C, 78 °C, 80 °C, 82 °C, 85 °C, 88 °C, 90 °C, etc., or it can be a range composed of any of the above values. According to the embodiments of the present application, the time of the second drying treatment is 20-30 h. For example, it can be 20 h, 22 h, 24 h, 26 h, 28 h, 30 h, etc., or it can be a range composed of any of the above values.

[0082] In some embodiments of the present application, the pomelo can be selected from at least one of other varieties such as, but not limited to, Guanxi honey pomelo, Shatian pomelo, Crystal pomelo, Thai Ruby, Vietnamese green pomelo, grapefruit, etc.

[0083] Method for preparing leather

[0084] With the development of society, the concept of environmental protection and sustainable development has been elevated to an important level by the country and even the world, and relevant laws and regulations are gradually being formed to implement it. Reducing the use of non-renewable resources on the earth and increasing the alternative use of renewable resources has become the only way for economic and social development. The raw materials of genuine leather itself come from animal hides, that is, raw hides, which are the skins of animals such as cattle and sheep that are slaughtered and eaten. Therefore, the raw materials themselves are renewable and recyclable. Environmentally friendly, but a large number of auxiliary materials used in the production process of genuine leather are chemical products. Most of them come from the refining and decomposition of petroleum or synthetic products based on petroleum raw materials, or are produced based on related mineral raw materials. Therefore, the consumption of non-renewable resources is relatively high. Traditional chrome-tanned leather products will also have heavy metal chromium residues. Therefore, in the process of preparing genuine leather, it is necessary to use renewable, low-carbon materials and chrome-free tanning processes as much as possible to reduce the use of non-renewable energy resources and solve the problem of heavy metal chromium residues in leather products.

[0085] Based on this, the inventors of this application have improved the tanning and retanning processes in addition to improving the finishing process in the traditional leather preparation process. By using bio-based tanning agents in tanning and bio-based tanning agents and bio-based fatliquors in the retanning process, the use of fossil and its derivative materials has been replaced, and the traditional chrome tanning process has been replaced by vegetable tanning. Among them, the raw materials in bio-based tanning agents and bio-based fatliquors are renewable and biodegradable, which effectively reduces the consumption of limited petroleum resources and solves the problem of heavy metal chromium residues in leather products.

[0086] Therefore, the present application proposes a method for preparing genuine leather. According to an embodiment of the present application, the preparation method comprises: performing retanning and finishing treatment on the genuine leather to be treated after preliminary tanning to obtain the genuine leather; wherein the finishing treatment is performed using the aforementioned genuine leather finishing method; the preliminary tanning is performed using a bio-based tanning agent, and the retanning treatment is performed using a bio-based tanning agent and a bio-based fatliquor.

[0087] Thus, the method for preparing genuine leather of the present application effectively improves the odor and formaldehyde emission of genuine leather by utilizing pomelo peel extract, formaldehyde remover, and bio-tanning technology, and obtains genuine leather products with low odor, low formaldehyde, low carbon, and chromium-free. On the one hand, the nanostructure of pomelo peel can adsorb odor molecules, thereby reducing the peculiar smell in the finished genuine leather; at the same time, volatile oil substances such as naringin and neohesperidin released by it can emit a fresh fragrance and neutralize the bad smell. On the other hand, the main component of the formaldehyde remover is an organic substance containing amino groups that combines to form a resin, and its reaction principle is to use the reaction between aldehydes and amino groups to block carbonyl groups, thereby reducing the release amount of aldehydes, so as to achieve the effect of reducing the release amount of aldehydes and lowering the value. In addition, using renewable plant resources such as pomelo peel, soy lecithin, and Chinese gallnut to replace traditional chemical, fossil, and their derivative materials not only reduces the overall carbon footprint and dependence on limited petroleum resources, but also solves the problem of heavy metal chromium residue in genuine leather products.

[0088] In some embodiments of the present application, the bio-based tanning agent includes Chinese gallnut, ethanol, methanol, glycerol, and water. Thus, by using the bio-based tanning agent of the present application, that is, Chinese gallnut tannin extract to replace fossil and its derivative materials for genuine leather processing, the overall carbon footprint can be reduced, and the problem of heavy metal chromium residue in genuine leather products can be solved.

[0089] In some embodiments of the present application, the mass ratio of the Chinese gallnut, the ethanol, the methanol, the glycerol, and the water is (45 - 55):(25 - 35):(5 - 15):(3 - 7):(3 - 7). For example, it can be 45:35:10:3:7, 50:30:10:5:5, 50:35:5:7:3, 55:25:10:5:5, etc., or it can be a range composed of any of the above values.

[0090] In some embodiments of the present application, the bio-based fatliquor includes soy lecithin, amino silicone oil, non-ionic surfactant, preservative, natural antibacterial agent, and water. Thus, by using soy lecithin to replace fossil and its derivative materials for genuine leather processing, the overall carbon footprint can be reduced.

[0091] In some embodiments of the present application, the mass ratio of the soy lecithin, the amino silicone oil, the non-ionic surfactant, the preservative, the natural antibacterial agent, and the water is (10 - 20):(1 - 3):(1 - 3):(0.0005 - 0.001):(0.0005 - 0.001):(70 - 85). For example, it can be 10:3:3:0.0005:0.0005:83.999, 20:1:1:0.001:0.001:77.998, etc., or it can be a range composed of any of the above values.

[0092] In some embodiments of the present application, the non-ionic surfactant includes but is not limited to at least one of Tween-80, Span-80, or fatty alcohol-polyethylene glycol ether.

[0093] In some embodiments of the present application, the preservative includes but is not limited to at least one of 2-octyl-4-isothiazolin-3-one, TCMTB (benzylisothiazolinone), CMK (chlorocresol), or OPP (o-phenylphenol).

[0094] In some embodiments of the present application, the natural antibacterial agent includes but is not limited to at least one of tea saponin, potassium sorbate, or sodium dimethyldithiocarbamate.

[0095] It should be noted that this application only details the differences from the prior art, and the remaining steps for preparing the dermis that are not mentioned are all conventional operations in the art.

[0096] Low-odor, low-formaldehyde dermis or low-odor, low-formaldehyde, low-carbon, chromium-free dermis and its applications

[0097] This application provides a low-odor, low-formaldehyde dermis or a low-odor, low-formaldehyde, low-carbon, chromium-free dermis. According to the embodiments of this application, the dermis is obtained by finishing the dermis to be treated using the aforementioned dermis finishing method to obtain the low-odor, low-formaldehyde dermis; or, the low-odor, low-formaldehyde, low-carbon, chromium-free dermis is prepared using the aforementioned preparation method. Thus, the dermis of this application has comfortable, healthy, and environmentally friendly characteristics such as low odor and low formaldehyde, or low odor, low formaldehyde, low carbon, and chromium-free. Those skilled in the art can understand that this dermis has all the features and advantages of the aforementioned dermis finishing method, and will not be elaborated here too much.

[0098] This application provides the application of the aforementioned low-odor, low-formaldehyde dermis or low-odor, low-formaldehyde, low-carbon, chromium-free dermis in automotive interiors.

[0099] In some embodiments of this application, the automotive interior includes automotive seats, steering wheels, armrests, etc.

[0100] Next, the solutions of this application will be explained in conjunction with embodiments. Those skilled in the art will understand that the following embodiments are only used to illustrate this application and should not be regarded as limiting the scope of this application. For those without specific techniques or conditions indicated in the embodiments, they shall be carried out according to the techniques or conditions described in the literature in the art or according to the product specifications. For reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0101] Example 1

[0102] 1. Preparation of pomelo peel extract

[0103] The fresh pomelo peel is washed, cut into pieces, and dried at 60 °C for 24 h to obtain dry small pieces of pomelo peel;

[0104] Mix 10 g of pomelo peel with 100 mL of ethanol solution with a mass fraction of 50%, stir for 24 h at room temperature to obtain modified pomelo peel;

[0105] Wash the modified pomelo peel with distilled water, dry it at 60 °C for 24 h, then add it to distilled water and grind it into a paste with a grinder so that the concentration of the modified pomelo peel is 2.5 g / 100 mL;

[0106] Put the paste in an oven at 80 ± 10 °C, dry it for 24 h, grind it and pass it through a 50-mesh sieve to obtain pomelo peel extract.

[0107] 2. Preparation of soy lecithin fatliquor

[0108] Raw material preparation (weight percentage): Prepare all raw materials according to the ratio of 15% soy lecithin, 2% amino silicone oil, 2% non-ionic surfactant (such as Tween-80), 0.001% preservative (such as 2-octyl-4-isothiazolin-3-one), 0.001% natural antibacterial agent (such as tea saponin) and 70 - 85% deionized water;

[0109] Dissolve lecithin: Add lecithin to an appropriate amount of deionized water, heat to about 60 - 70 °C, stir while heating until the lecithin is completely dissolved to obtain a lecithin solution;

[0110] Add hydrophilic amino silicone oil and non-ionic surfactant: Add hydrophilic amino silicone oil and non-ionic surfactant to the lecithin solution and continue to stir evenly;

[0111] Add preservative and natural antibacterial agent: Slowly add the preservative and natural antibacterial agent during stirring to ensure uniform dispersion;

[0112] Cooling and filtration: Cool the above solution to room temperature, and then remove possible impurities and particles through an appropriate filter to obtain a bio-based fatliquor;

[0113] Detection and adjustment: Conduct quality detection on the prepared bio-based fatliquor, with a viscosity of 600 - 2000 CPS, a pH value of 4 - 9, a stability of normal temperature storage for 3 - 6 months, and a bio-fatliquor content of 60 - 80%.

[0114] 3. Preparation of gallnut tannin

[0115] Raw material preparation (weight percentage): Prepare all raw materials according to the ratio of 50% gallnut powder, 30% ethanol, 10% methanol, 5% glycerol and 5% deionized water;

[0116] Mixed solution: In a clean container, first add the calculated amounts of ethanol and methanol. Slowly add the gallnut powder while stirring to ensure uniform dispersion of the powder. Then add deionized water and continue stirring. Finally, add glycerol and stir well until a homogeneous solution is formed;

[0117] Standing and filtering: Let the mixed solution stand for 24 hours to allow the active ingredients in the gallnut to dissolve fully. Use filter paper or a strainer to filter out the undissolved solid particles to obtain a clear bio-based tanning agent;

[0118] Testing and verification: Conduct performance tests and verifications on the prepared vegetable tanning agent, such as shrinkage temperature (Ts), pH value, incision color, etc., to ensure it meets the tanning requirements.

[0119] 4. Preparation of dermis

[0120] 1) Batching: Group the raw hides according to their origin, season, and size of the hide. Weigh the raw hides and put them into a rotating drum;

[0121] 2) Soaking: Add water to the rotating drum according to a solid-liquid ratio of 1:5 to soak the raw hides. Successively add 0.5% soaking aid, 0.4% fungicide, 0.2% degreasing agent, and 0.2% soda ash to adjust the pH of the water in the rotating drum to 7.5. The soaking temperature is 22 - 26°C, and the soaking time is 18 - 24h;

[0122] 3) Fleshing: Take out the raw hides that have been soaked and use a fleshing machine to remove the fat and residual meat in the subcutaneous tissue;

[0123] 4) Liming: Put the fleshed raw hides in a rotating drum, add 0.2% depilation enzyme, 1.7% sodium hydrosulfide, and 3% lime. The initial liquor ratio is about 1:2 and finally reaches 2.0. The soaking temperature is 22 - 26°C, and the soaking time is 18 - 24h;

[0124] 5) Deliming: 2% deliming agent, temperature 32°C, liquor ratio 0.5 - 1.0, time 60 - 90 minutes, pH value 8.0 - 8.5, check the incision with phenolphthalein and it should be colorless;

[0125] 6) Bating: Add 0.2% bating enzyme to treat the delimed raw hides. Control the pH at 8 - 8.5, the temperature at 30 - 32°C, and the time at 60 - 90 min;

[0126] 7) Pickling: After bating, add 0.5% formic acid and 0.5% sulfuric acid solution to the rotating drum for soaking. The liquor ratio is 0.8, the soaking temperature is 22°C, and the soaking time is 5h;

[0127] 8) Tanning: Add 20 - 30% gallnut tannin preparation to the drum. Control the pH of tanning at 3.4, with an initial temperature of 25°C and a time of 8 hours. After the final tanning temperature reaches 38°C, let it stand for 2 days to obtain wet blue leather.

[0128] 9) Pretreatment before dyeing: Squeeze water, split the leather, and shave the wet blue leather obtained in step 8, then add 2% sodium bicarbonate solution to control the pH of the solution in the drum at 5.8.

[0129] 10) Retanning and dyeing process: Put the preliminarily tanned leather into the retanning and dyeing drum. According to the proportion and process requirements of the process formula, add appropriate amount of water, 20 - 30% gallnut tannin vegetable tanning agent, and 10 - 15% soybean lecithin fatliquor. After adding them gradually, start the stirring equipment to make the tanning agent fully penetrate and distribute in the leather. Then, according to the product requirements, add other auxiliaries such as softener and waterproof agent to improve the performance of the leather. Calculate the dosage based on the weight of the wet blue leather after shaving. The dosage of the waterproof agent is 2% - 5%. Retan for several hours to dozens of hours. During this period, regularly check the state of the leather. When the leather uniformity, plumpness, firmness, and smoothness of the grain surface meet the requirements, the retanning can be stopped. It is required that the dyeing of the leather surface is uniform, the leather feels soft, plump and elastic when touched, and the grain surface bends inward. Check that the firmness of the grain surface meets the requirement of VDA230 - 206, ≤ 3 grades.

[0130] 11) Dry, re - humidify, and soften the leather obtained in step 10

[0131] Use a vacuum dryer to vacuum - dry the dyed leather to a moisture content of 30 - 40%, and then use a conditioning dryer to dry the moisture of the leather to 8 - 10%. After standing and curing for 4 hours, spray water on the reverse side of the leather for re - humidification. The reason is that the leather body will become harder after drying. Spray a little water to re - humidify the leather embryo to a moisture content of 14 - 17%, and then use a softening machine to stretch and beat the leather up and down with the machine to make the leather stretch out.

[0132] 12) The finishing process is carried out in the following steps:

[0133] a. Soften the leather by putting it into a softening drum and softening it for 6 - 10 hours to make the softness of the leather reach 5.0 - 6.0.

[0134] b. Stretching on board: Place the leather on the plane of the stretching - on - board machine and fix it with stretching - on - board clips. The stretching - on - board machine stretches with a tension of about 40 mm and fixes the leather under the condition of 40 ± 5°C to eliminate the wrinkles and deformation caused by softening.

[0135] c. Buff the leather: Use a buffing machine equipped with 280 - 600 - mesh sandpaper to buff the surface of the genuine leather to remove some natural defects and make the surface of the genuine leather more uniform.

[0136] d. Roller filling: The leather is roller filled, and the roller coater roller fills the resin at 15 - 20 g / sf 2 ;

[0137] e. Board stretching and drying: The moisture content of the dried leather is 6 - 9%;

[0138] f. Roller applying damage repair agent: The roller coater roller applies the damage repair agent at 3 - 5 g / sf 2 ;

[0139] g. After machine roller damage repair, spot damage repair is carried out, and after the damage repair is completed, the leather is dried by baking;

[0140] h. Fine leather grinding: Once with 280 - 400 mesh, once with 400 - 600 mesh, after leather grinding, the edges are trimmed and dust is removed;

[0141] i. Roller applying pomelo peel extract: The roller coater roller applies the pomelo peel extract at 2 - 4 g / sf 2 ;

[0142] j. Roller applying formaldehyde removal agent: The roller coater roller applies the formaldehyde removal agent at 2 - 4 g / sf 2 ;

[0143] k. Ironing the leather interior, temperature 90°C, pressure 30 kg / cm 2 - 50 kg / cm 2 , ironing once;

[0144] l. Secondary roller damage repair: The roller coater roller applies the damage repair agent at 2 - 4 g / sf 2 ;

[0145] m. Roller applying base coat: The roller coater roller applies the base coat resin at 8 - 12 g / sf 2 。

[0146] n. Embossing: Using a flower roller configured with a customized texture, the surface of the genuine leather is embossed to obtain a texture product customized by the customer;

[0147] o. Top coating: Using a spraying machine, spray the top coating numerical formula on the surface of the genuine leather, where the color layer is 2.3 - 2.8 g / SF, 2 - 3 coats, the bright layer is 2.3 - 2.8 g / SF, 2 - 3 coats, the drying temperature is 100 - 120°C, and after spraying, it needs to be left standing for 24 hours for curing;

[0148] p. Hanging to dry: Hang the genuine leather on the hanging rod, at room temperature, for more than 24 hours, and carry out ventilation and odor removal treatment; Finally, the finished genuine leather is obtained.

[0149] Comparative Example 1

[0150] In the finishing process, pomelo peel extract is not added, and the rest are the same as in Example 1.

[0151] Comparative Example 2

[0152] During the retanning process, the gallnut tannin agent and soybean lecithin fatliquor were replaced with a chrome tanning retanning agent and a mineral oil fatliquor, and the rest was the same as in Example 1.

[0153] Comparative Example 3

[0154] During the retanning process, the gallnut tannin agent was replaced with a chestnut tannin retanning agent, and the rest was the same as in Example 1.

[0155] Comparative Example 4

[0156] During the retanning process, the soybean lecithin fatliquor was replaced with an animal oil fatliquor, and the rest was the same as in Example 1.

[0157] Comparative Example 5

[0158] During the finishing process, the aldehyde removal agent was not added, and the rest was the same as in Example 1.

[0159] Performance Test Experiment

[0160] 1. The odor performance of the genuine leather prepared in Example 1 and Comparative Examples 1-5 was detected, and the test items and results are shown below.

[0161] Odor performance detection method: Referring to the odor properties of automotive interior materials in Standard VDA 270, 200 cm 2 of each genuine leather sample was taken, the sample was placed in an odor bottle, and then the odor bottle with the sample was placed in an 80 °C oven for 2 h, and then the odor intensity evaluation was carried out.

[0162] The experimental results are shown in Table 1. The results show that the pomelo peel extract can effectively improve the odor performance of genuine leather products. Using the gallnut tannin agent and soybean lecithin fatliquor as auxiliaries is better than other comparative examples and can assist in improving the odor performance of genuine leather products.

[0163] Table 1

[0164]

[0165]

[0166] 2. The formaldehyde performance of the genuine leather prepared in Example 1 and Comparative Examples 1-5 was detected, and the test items and results are shown below.

[0167] Formaldehyde performance detection method: Referring to ISO 12219-2-2012 Road vehicles - Interior air - Part 2: Determination of volatile organic compounds emitted by automotive interiors and materials - Screening method, 20*20 cm genuine leather samples were taken, the samples were placed in a 10 L bag, and then the bag with the samples was placed in a 65 °C oven for 2 h, and then formaldehyde sampling analysis was carried out using a DNPH tube.

[0168] The experimental results are shown in Table 2. The results indicate that the formaldehyde remover can effectively improve the formaldehyde emission of leather products. Adding pomelo peel extract is superior to other comparative examples and can assist in improving the formaldehyde emission of leather products.

[0169] Table 2

[0170] <![CDATA[Formaldehyde (ug / m 3 )]]> Example 1 Not detected Comparative Example 1 Not detected Comparative Example 2 Not detected Comparative Example 3 Not detected Comparative Example 4 Not detected Comparative Example 5 147

[0171] 3. The true leather obtained from Example 1 and Comparative Examples 1-5 was subjected to low-carbon performance testing. The test items and test results are as follows.

[0172] For the bio-based content test, refer to ASTM D6866, the test method for determining the biological content of solid, liquid, and gas samples by radiocarbon analysis, expressed as a percentage of carbon. It is completed by comparing the relative content of radioactive carbon (C14) in the sample with the standard of the radioactive carbon content in the modern atmosphere, and the ratio of fossil carbon to bio-based carbon in the product can be obtained.

[0173] The experimental results are shown in Table 3. The results indicate that the bio-based carbon content of the leather products using gallnut tannin and soy lecithin fatliquor as auxiliaries is superior to that of chrome tanning agents, mineral oil fatliquors, animal oil fatliquors, and chestnut wood extract retanning agents.

[0174] Table 3

[0175]

[0176]

[0177] 4. The true leather obtained from Example 1 and Comparative Examples 1-5 above was subjected to finished product performance testing. The test items and test results are as follows.

[0178] Aging resistance grade test: Refer to QBT 5250-2018. Take samples, 50mm×200mm, 3 pieces, put them into an aging test machine at a temperature of 100°C ± 2°C and keep for 72h. Then take out the samples and cool them at room temperature for 0.5h. Then cut 3 pieces of samples of 20mm×60mm along the vertical and horizontal directions of the samples. Overlap the two ends in the length direction with the coating facing outwards, and keep them in a low-temperature box at (-20 ± 2)°C for 5min. After taking them out, let a 2.5kg weight fall freely from a height of 50mm above the plane along the folding line of the sample within 5s.

[0179] The experimental results are shown in Table 4. The results indicate that the aging resistance grade performance of the examples and the comparative examples is basically the same, and the aging resistance performance of the leather products obtained with chestnut wood extract retanning agent is relatively weaker.

[0180] Table 4

[0181] Aging resistance level (the higher the level, the better) Example 1 Level 4 Comparative Example 1 Level 4 Comparative Example 2 Level 4 Comparative Example 3 Level 3 Comparative Example 4 Level 4 Comparative Example 5 Level 4

[0182] 5. The finished leather products obtained from the above-mentioned Example 1 and Comparative Examples 1-5 were subjected to finished product performance testing, and the test items and test results are shown below.

[0183] Heavy metal chromium residue test: GB / T 22930-2008 Leather and fur - Chemical tests - Determination of heavy metal content

[0184] The experimental results are shown in Table 5. The results show that the heavy metal chromium residues in the examples and comparative examples are basically the same, and the heavy metal chromium residue in the genuine leather products obtained by the traditional chrome tanning process is higher than that in the vegetable tanning process.

[0185] Table 5

[0186] Heavy metal chromium content (mg / kg) Example 1 Not detected Comparative Example 1 Not detected Comparative Example 2 86 Comparative Example 3 Not detected Comparative Example 4 Not detected Comparative Example 5 Not detected

[0187] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A method for finishing leather, characterized in that: include: Grapefruit peel extract and formaldehyde remover are roller-coated on the leather surface.

2. The leather finishing method according to claim 1, characterized in that: Firstly, the grapefruit peel extract is roller-coated on the surface of the leather, and then the formaldehyde remover is roller-coated on the surface of the leather coated with the grapefruit peel extract.

3. The leather finishing method according to claim 2, characterized in that: Before the grapefruit peel extract is used to roll-coat the leather surface, the method further comprises: Roll-coating a filling resin on the surface of the leather; Apply the first wound repairing cream to the dermis surface after the filling resin is applied by roller; And / or, after the dermis surface on which the grapefruit peel extract is roller-coated with a formaldehyde remover, the method further comprises: Apply the second wound repairing ointment on the dermis surface after the formaldehyde remover is applied by roller; Roller-coat the primer resin on the dermis surface where the second wound repairing cream is applied.

4. The leather finishing method according to claim 3, characterized in that: The coating dosage of the grapefruit peel extract is 2-4 g / sf 2 ; And / or, the coating dosage of the formaldehyde removal agent is 2-4g / sf 2 .

5. The leather finishing method according to claim 1, characterized in that: The grapefruit peel extract is prepared by the following method: The grapefruit peel is subjected to a first drying process to obtain a dried grapefruit peel; The dried grapefruit peel is mixed with a modification agent to obtain modified grapefruit peel; Grinding the modified grapefruit peel with water to obtain a paste-like modified grapefruit peel; The modified grapefruit peel paste is subjected to a second drying process to obtain the grapefruit peel extract.

6. A method for preparing leather, characterized in that: include: Performing retanning and finishing treatments on the preliminarily tanned genuine leather to be treated to obtain the genuine leather; Wherein, the finishing treatment is carried out by adopting the leather finishing method according to any one of claims 1 to 5; The preliminary tanning is carried out using a bio-based tanning agent; The retanning process is carried out using a bio-based tanning agent and a bio-based fatliquor.

7. The preparation method according to claim 6, characterized in that: The bio-based tanning agent includes gallnut, ethanol, methanol, glycerol and water; And / or, the bio-based fatliquor comprises soybean lecithin, amino silicone oil, nonionic surfactant, preservative, natural antibacterial agent and water.

8. The preparation method according to claim 7, characterized in that: The mass ratio of the gallnut, the ethanol, the methanol, the glycerol and the water is (45-55):(25-35):(5-15):(3-7):(3-7); And / or, the mass ratio of the soybean lecithin, the amino silicone oil, the nonionic surfactant, the preservative, the natural antibacterial agent and the water is (10-20):(1-3):(1-3):(0.0005-0.001):(0.0005-0.001):(70-85).

9. A low-odor, low-formaldehyde genuine leather or a low-odor, low-formaldehyde, low-carbon, chrome-free genuine leather, characterized in that: The low-odor and low-formaldehyde leather is obtained by coating the leather to be treated using the leather coating method according to any one of claims 1 to 5; Or, the low-odor, low-formaldehyde, low-carbon, chrome-free genuine leather is prepared by the preparation method described in any one of claims 6 to 8.

10. Use of the low-odor, low-formaldehyde genuine leather or the low-odor, low-formaldehyde, low-carbon, chrome-free genuine leather as claimed in claim 9 in automobile interior decoration.

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