Artificial leather material based on utilization of plant residue waste and preparation method thereof

Abstract

This application relates to the technical field of artificial leather preparation, specifically disclosing an artificial leather material based on the utilization of plant residue waste and its preparation method. The artificial leather material comprises the following raw materials in parts by weight: 20-30 parts pretreated plant residue, 10-15 parts aqueous polyurethane emulsion, 10-30 parts modified latex emulsion, 2-4 parts silicone oil, and 3-5 parts crosslinking agent; the modified latex emulsion is obtained by epoxy-modifying latex. The artificial leather material of this application has the advantages of significantly excellent air permeability and mechanical properties that meet usage requirements.

Description

Technical Field

[0001] The present application relates to the technical field of artificial leather preparation, and more specifically, to an artificial leather material based on the utilization of plant residue waste and a preparation method thereof. Background Art

[0002] As people's environmental awareness increases, the non-degradability and environmental pollution problems of traditional PVC and PU artificial leathers have attracted more and more attention. It is of great significance to prepare artificial leather using natural plant raw material residues.

[0003] Plant residues contain a high amount of cellulose and lignin. Effectively utilizing these solid residues could reduce the production cost of artificial leather and, to a certain extent, address the environmental pollution issues associated with artificial leather. However, directly utilizing plant residues can result in poor performance, such as poor breathability, in the resulting artificial leather.

[0004] Therefore, it is necessary to provide a method for preparing artificial leather using plant residues as raw materials and artificial leather having excellent air permeability and certain mechanical properties. Summary of the Invention

[0005] In order to improve the air permeability of artificial leather made from plant residues as raw materials, the present application provides an artificial leather material based on the utilization of plant residue waste and a preparation method thereof.

[0006] In a first aspect, the present application provides an artificial leather material based on the utilization of plant residue waste, which adopts the following technical solution:

[0007] An artificial leather material based on the utilization of plant residue waste comprises the following raw materials in parts by weight:

[0008] 20-30 parts of pretreated plant residues, 10-15 parts of waterborne polyurethane emulsion, 10-30 parts of modified latex emulsion, 2-4 parts of silicone oil, and 3-5 parts of crosslinking agent;

[0009] The modified latex emulsion is obtained by epoxy-modifying latex.

[0010] By adopting the above technical solution, the present application modifies the latex with epoxy, which has the following effects: 1. After epoxy modification, the latex molecules contain more active groups, so as to significantly improve the binding activity and binding stability of the pretreated plant residues and the modified latex; 2. After epoxy modification, the steric hindrance of the latex molecules is significantly increased, and after combining with the pretreated plant residues, the amount of molecules such as cellulose bound to its unit molecule is reduced, and the binding stability is stronger; 3. After epoxy modification, the steric hindrance of the latex molecules is significantly increased, so that the air permeability of the prepared artificial leather material is significantly improved.

[0011] In this application, plant residues refer to the residues of various plants after various treatments; any plants containing plant cellulose, lignin, etc. can be selected; the treatment methods can be crushing, reagent treatment (acid treatment, alkali treatment, etc.), plant extract extraction (such as tannin, protein, polysaccharide, etc. extraction), etc.

[0012] Optionally, the plant residue is plant residue after tara tannin extraction.

[0013] Tara, also known as spiny vine fruit or spiny bean, is an evergreen thorny shrub or small tree. Tara is highly valuable due to its rich tannin content. The waste residue produced after tara tannin extraction is also known as industrial waste. This application utilizes this waste residue after tara tannin extraction to produce a biodegradable artificial leather product.

[0014] Optionally, the preparation method of the modified latex emulsion comprises the following steps:

[0015] Step 1: mixing rubber latex and epoxy reagent to obtain a premixed solution; wherein the epoxy reagent is added in an amount of 0.5-1.2% by weight of the rubber latex;

[0016] Step II: adding an emulsifier to the premixed solution, adjusting the pH to 9-11, and performing an emulsification reaction to obtain a modified latex emulsion.

[0017] By adopting the above technical solution, an appropriate amount of epoxy reagent is mixed with rubber latex to react, thereby obtaining an artificial leather material with excellent breathability. If the epoxy reagent is added in too little amount, the breathability of the artificial leather material will be affected; if the epoxy reagent is added in too much amount, the mechanical properties of the artificial leather material will be affected.

[0018] Optionally, the epoxy agent is selected from any one or more of ethylene oxide modified sodium thiosulfate, epichlorohydrin, peroxide and peracid; preferably, the epoxy agent is selected from any one or more of ethylene oxide modified sodium thiosulfate and epichlorohydrin.

[0019] Optionally, the peroxide is selected from any one or more of benzoyl peroxide and hexanoyl peroxide. Further optionally, the peracid is selected from any one or more of oxalic acid and trifluoroperacetic acid.

[0020] The main advantages of ethylene oxide-modified sodium thiosulfate are mild reaction conditions, low byproduct generation, high epoxidation efficiency, and relatively simple operation. Other epoxidation reagents may have harsh reaction conditions or require catalysts, resulting in a high number of byproducts. If a replacement is necessary, epichlorohydrin is recommended, as it is most similar to ethylene oxide in epoxidation modification reactions.

[0021] Optionally, the emulsification in step II is accompanied by stirring, with a stirring speed of 300-500 rpm and a stirring time of 30-60 min. Optionally, the emulsification is performed at room temperature, with a temperature of 25-35°C.

[0022] Optionally, the amount of the emulsifier added is 0.6-0.9% by weight of the premix.

[0023] Optionally, the emulsifier is selected from any one or more of methyl cellulose, guar gum, gum arabic, tannin and phospholipid; further optionally, the phospholipid is soybean lecithin.

[0024] Optionally, the particle size of the latex particles in the modified latex emulsion is 100-500 nm.

[0025] Optionally, the method for preparing the pretreated plant residues comprises the following steps:

[0026] Step 1: Dispersing and homogenizing the plant residue to obtain residue particles;

[0027] Step ②, soaking the residue particles in alkali solution, reacting, and then microwave-treating to obtain a refined residue;

[0028] Step ③: The refined residue is washed and dried to obtain the pretreated plant residue.

[0029] By adopting the above technical solution, the dispersion and homogenization operation of step ① can loosen the structure of the cellulose and lignin parts wrapped by the polysaccharide, which is convenient for the exposure of chemical functional groups in the subsequent treatment process and is conducive to the cross-linking reaction in the emulsification system in the later stage. The purpose of the alkali treatment in step ② is to fully swell and activate the cellulose, lignin and other components in the residue, and expose more active groups such as hydroxyl groups; at the same time, it can remove the lignin and aliphatic components in the residue, purify the cellulose in the residue, and further refine the fibers and increase its specific surface area; and the microwave collaboration can significantly increase the reaction rate, making the treatment effect more significant; the treated residue can form a better interfacial bonding force with the water-based polyurethane and modified latex, and improve its dispersibility in the subsequent blended emulsion, so that the reaction between the plant residue and the water-based polyurethane and modified latex is more sufficient, and the mutual bonding force between the three is more stable, so as to significantly improve the air permeability of the artificial leather material and ensure the mechanical properties of the artificial leather material.

[0030] Optionally, in step ①, the particle size of the residue particles obtained is 150-200 mesh.

[0031] Optionally, in step ①, the dispersing includes: dispersing at a rotation speed of 10,000-15,000 rpm for 10-20 min; and the homogenizing includes: homogenizing at a pressure of 60-80 MPa.

[0032] By adopting the above technical solution, the plant residues are fully pretreated, the active groups on the surface are fully exposed and the residue surface is activated.

[0033] Optionally, in step ②, the alkali solution is a 0.5-3 wt% sodium hydroxide solution; the reaction conditions include: reaction time of 2-4 h, reaction temperature of 60-80° C., and solid-liquid ratio of 1:(4-5).

[0034] Optionally, in step ②, the microwave treatment conditions include: treatment time of 10-15 min, microwave frequency of 2200-2600 MHz, and power of 300-500 W.

[0035] Optionally, the thickness of the artificial leather material is 0.8-1.2 mm.

[0036] In a second aspect, the present application provides a method for preparing the above-mentioned artificial leather material based on the utilization of plant residue waste, which adopts the following technical solution:

[0037] A method for preparing an artificial leather material based on the utilization of plant residue waste comprises the following steps: Step 1, mixing pretreated plant residue, aqueous polyurethane emulsion, modified latex emulsion, silicone oil and a crosslinking agent, and dispersing them uniformly to obtain a raw material mixture;

[0038] Step 2, heating the raw material mixture and then keeping it warm for reaction to obtain a composite emulsion;

[0039] Step 3: Cooling the composite emulsion, homogenizing, adjusting the pH to 10-11, and stirring evenly to obtain an artificial leather material emulsion; Step 4: Applying the artificial leather material emulsion to a base fabric and drying to obtain the artificial leather material.

[0040] By adopting the above technical solution, through the reaction in step 2, the isocyanate groups in the waterborne polyurethane undergo polymerization and cross-linking reactions, and chemically react with the carboxyl and hydroxyl groups in the natural latex. The cellulose and other components in the residue also participate in the reaction. The three raw materials interact to form a stable three-dimensional network structure, ultimately producing a stable composite emulsion. This composite emulsion is further processed and used to prepare artificial leather materials, resulting in a material with significantly improved air permeability.

[0041] Optionally, the uniform dispersion in step 1 specifically includes the steps of high-speed homogenization and ultrasonic homogenization;

[0042] The conditions for high-speed homogenization include: a stirring speed of 8000-12000 rpm and a stirring time of 10-15 min;

[0043] The ultrasonic homogenization conditions include: ultrasonic frequency of 15-25 kHz, and ultrasonic time of 5-10 min.

[0044] Optionally, in step 2, the heating temperature is 60-80° C., and the insulation reaction time is 1-3 h.

[0045] Optionally, the coating in step 4 can be performed once or multiple times; when multiple times are performed, each coating is dried before the next coating is performed.

[0046] Optionally, the coating amount in step 4 is 80-120g / m 2 , the coating times are 2-3 times.

[0047] Optionally, the drying temperature in step 4 is 80-120°C.

[0048] In summary, this application has the following beneficial effects:

[0049] The present application makes use of plant residues, especially the residues after tara tannin extraction, to prepare an environmentally friendly and biodegradable artificial leather material. The material is made from the residues after tara tannin extraction, which is dispersed and homogenized and then treated with alkali solution and microwave to fully purify the cellulose and expose the active groups (hydroxyl and carboxyl groups, etc.) on the surface of the residue; the pretreated plant residue is used together with a modified latex emulsion and an aqueous polyurethane emulsion to prepare the artificial leather material, wherein the modified latex emulsion is epoxidized and modified. On the one hand, the epoxidation modification makes the latex emulsion have more active sites, and on the other hand, it makes the latex molecules have greater steric hindrance during the reaction, so as to prepare an artificial leather material with significantly excellent air permeability; in addition, when the product is prepared, the isocyanate groups in the aqueous polyurethane undergo polymerization and cross-linking reactions, and react chemically with the carboxyl and hydroxyl groups in the natural latex. The cellulose and lignin in the residue also participate in the reaction. The three interact to form a stable three-dimensional network structure to prepare a stable composite emulsion, thereby ensuring the excellent air permeability of the obtained artificial leather material. DETAILED DESCRIPTION

[0050] The present application is further described in detail below with reference to the examples. It is particularly noted that if no specific conditions are specified in the following examples, the reactions are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0051] Preparation example of pretreated plant residues

[0052] In the following preparation examples, the residue after extraction of tara tannin is used as an example to illustrate this embodiment.

[0053] Preparation Example 1

[0054] The method for preparing the residue after pre-treatment of tara tannin extraction is as follows:

[0055] Step 1., the residue after Tara tannin extraction is pre-treated with a release-type high-speed fighting machine (ZRM-120 type fighting machine of Bosch, Germany). During fighting, the rotating speed is set to 10000rpm, and the fighting time is 20min to break the residue tissue. Subsequently, it is homogenized with a Stansted type high-pressure homogenizer, and the homogenization pressure is set to 60MPa, and circulated three times to further reduce and homogenize the residue particle size to obtain a residue particle size of 150-200 mesh.

[0056] Step ②: Soak the residue particles in a 0.5wt% sodium hydroxide solution at a solid-liquid ratio of 1:4 at 80°C for 4 hours. After the reaction, the alkali-treated residue is subjected to microwave irradiation in an XYZ-5 microwave chemical reactor under the following conditions: microwave frequency of 2200MHz, power of 300W, and treatment time of 15 minutes to obtain a refined residue;

[0057] Step ③: The refined residue is filtered to remove the sodium hydroxide solution, then washed with water, and then dried. The specific drying steps are as follows: drying is performed in multiple stages, first using steam-heated hot air drying to quickly reduce the moisture by 80%, then using microwave drying at a drying temperature of 100°C for 3 hours to a moisture content of 10.64 wt%. The pretreated plant residue reaches a stable weight, thereby obtaining a pretreated tara tannin extraction residue, which is set aside.

[0058] Preparation Example 2

[0059] The method for preparing the residue after pre-treatment of tara tannin extraction is as follows:

[0060] Step 1., the residue after Tara tannin extraction is pre-treated with a release type high-speed fighting machine (ZRM-120 type fighting machine of Bosch Co., Germany). When fighting, the rotating speed is set to 12000rpm, and the fighting time is 15min to break the residue tissue. Subsequently, it is homogenized with a Stansted type high-pressure homogenizer, and the homogenization pressure is set to 70MPa, and circulated three times to further reduce and homogenize the residue particle size to obtain a residue particle size of 150-200 mesh.

[0061] Step ②: Soak the residue particles in a 1.5 wt% sodium hydroxide solution at a solid-to-liquid ratio of 1:4.5 at 70°C for 3 hours. After the reaction, the alkali-treated residue was subjected to microwave irradiation in an XYZ-5 microwave chemical reactor under the following conditions: microwave frequency of 2400 MHz, power of 400 W, and treatment time of 12 minutes to obtain a refined residue.

[0062] Step ③: The refined residue is filtered to remove the sodium hydroxide solution, then washed with water, and then dried. The specific drying steps are as follows: drying is performed in multiple stages, first using steam-heated hot air drying to quickly reduce the moisture by 85%; then using microwave drying at a drying temperature of 110° C. for 2.5 hours to a moisture content of 10.02 wt %. The pre-treated plant residue reaches a stable weight, and the residue after pre-treatment of tara tannin extraction is set aside.

[0063] Preparation Example 3

[0064] The method for preparing the residue after pre-treatment of tara tannin extraction is as follows:

[0065] Step 1., the residue after Tara tannin extraction is pre-treated with a release type high-speed fighting machine (ZRM-120 type fighting machine of Bosch Co., Germany). During fighting, the rotating speed is set to 15000rpm, and the fighting time is 10min to break the residue tissue. Subsequently, it is homogenized with a Stansted type high-pressure homogenizer, and the homogenization pressure is set to 80MPa, and circulated twice to further reduce and homogenize the residue particle size to obtain a residue particle size of 150-200 mesh.

[0066] Step ②: Soak the residue particles in a 3wt% sodium hydroxide solution at a solid-liquid ratio of 1:5 at 60°C for 2 hours. After the reaction, the alkali-treated residue is subjected to microwave irradiation in an XYZ-5 microwave chemical reactor under the following conditions: microwave frequency of 2600 MHz, power of 500 W, and treatment time of 10 minutes to obtain a refined residue;

[0067] Step 3: The refined residue is filtered to remove the sodium hydroxide solution, then washed with water, and then dried. The specific drying steps are as follows: drying is carried out in multiple stages, first using steam-heated hot air drying to quickly reduce the moisture by 75%; then using microwave drying at a drying temperature of 120°C for 2 hours to a moisture content of 12.37 wt%. The pre-treated plant residue reaches a stable weight, and the residue after pre-treatment of tara tannin extraction is set aside.

[0068] Preparation example of waterborne polyurethane emulsion

[0069] Preparation Example 1

[0070] The preparation method of waterborne polyurethane emulsion is:

[0071] a) Prepare an aqueous polyurethane dispersion with a solid content of 20 wt%, add 0.2 wt% of a thickener, 0.1 wt% of a pH regulator, and stir at a high speed of 8000 rpm to prepare a uniform aqueous polyurethane premix.

[0072] b) The aqueous polyurethane premix was mixed with 0.5 times the weight of water, 1 wt% of an emulsifier was added for emulsification reaction, the pH value was adjusted to 8-9, and an aqueous polyurethane emulsion with a particle size of 100-300 nm was obtained after high-speed shear emulsification at 10,000 rpm.

[0073] Preparation Example 2

[0074] The preparation method of waterborne polyurethane emulsion is:

[0075] a) Prepare an aqueous polyurethane dispersion with a solid content of 25 wt%, add 0.35 wt% of a thickener, 0.2 wt% of a pH adjuster, and stir at a high speed of 9000 rpm to prepare a uniform aqueous polyurethane premix.

[0076] b) The aqueous polyurethane premix was mixed with 0.8 times the weight of water, 2 wt% of an emulsifier was added for emulsification reaction, the pH value was adjusted to 8-9, and an aqueous polyurethane emulsion with a particle size of 100-300 nm was obtained after high-speed shear emulsification at 13000 rpm.

[0077] Preparation Example 3

[0078] The preparation method of waterborne polyurethane emulsion is:

[0079] a) Prepare an aqueous polyurethane dispersion with a solid content of 30 wt%, add 0.5 wt% of a thickener, 0.3 wt% of a pH adjuster, and stir at a high speed of 10,000 rpm to prepare a uniform aqueous polyurethane premix.

[0080] b) The aqueous polyurethane premix was mixed with 1 weight percent water, 3 wt% of an emulsifier was added for emulsification, the pH value was adjusted to 8-9, and an aqueous polyurethane emulsion with a particle size of 100-300 nm was obtained after high-speed shear emulsification at 16,000 rpm.

[0081] Preparation example of modified latex emulsion

[0082] Preparation Example 1

[0083] The preparation method of modified latex emulsion is:

[0084] Step I: Mix SVR3 natural rubber latex (Bangkok Company) imported from Malaysia and epichlorohydrin, with the epichlorohydrin added in an amount of 0.5wt% of the natural rubber latex, and mix well to obtain a premixed solution.

[0085] Step II: adding deionized water and guar gum as an emulsifier to the premix, wherein the amount of guar gum added is 0.6 wt % of the premix, and the amount of deionized water added is twice the weight of the premix, adjusting the pH to 9-11, and performing an emulsification reaction; specifically, the emulsification reaction is performed at room temperature and stirring at a speed of 300 rpm for 60 minutes to obtain a modified latex emulsion.

[0086] Preparation Example 2

[0087] The preparation method of modified latex emulsion is:

[0088] Step I: SVR3 natural rubber latex (Bangkok Corporation) imported from Malaysia and ethylene oxide-modified sodium thiosulfate (Kao Corporation, trade name Newcol 560SF) were mixed, with the ethylene oxide-modified sodium thiosulfate added in an amount of 0.9wt% based on the natural rubber latex, and the mixture was uniformly mixed to obtain a premixed solution.

[0089] Step II: adding deionized water and emulsifier methyl cellulose to the premix, wherein the amount of methyl cellulose added is 0.8 wt % of the premix, and the amount of deionized water added is 2.5 times the weight of the premix, adjusting the pH to 9-11, and performing an emulsification reaction; specifically, during the emulsification, stirring at a speed of 400 rpm at room temperature for 45 minutes to obtain a modified latex emulsion.

[0090] Preparation Example 3

[0091] The preparation method of modified latex emulsion is:

[0092] Step I: SVR3 natural rubber latex (Bangkok Corporation) imported from Malaysia and ethylene oxide-modified sodium thiosulfate (Kao Corporation, trade name Newcol 560SF) were mixed, with the ethylene oxide-modified sodium thiosulfate added in an amount of 1.2 wt % based on the natural rubber latex, and the mixture was uniformly mixed to obtain a premixed solution.

[0093] Step II: adding deionized water and emulsifier methyl cellulose to the premix, wherein the amount of methyl cellulose added is 0.9 wt % of the premix, and the amount of deionized water added is 3 times the weight of the premix, adjusting the pH to 9-11, and performing an emulsification reaction; specifically, during the emulsification, stirring is performed at a speed of 500 rpm at room temperature for 30 minutes to obtain a modified latex emulsion.

[0094] Preparation Examples 4-7

[0095] The difference between Preparation Example 4-7 and Preparation Example 2 is that the amount of epoxy reagent added is different, as follows:

[0096] In Preparation Example 4, the amount of ethylene oxide-modified sodium thiosulfate added is 0.2 wt% of the natural rubber latex;

[0097] In Preparation Example 5, the amount of ethylene oxide-modified sodium thiosulfate added is 0.5 wt% of the natural rubber latex;

[0098] In Preparation Example 6, the amount of ethylene oxide-modified sodium thiosulfate added is 1.2 wt % of the natural rubber latex;

[0099] In Preparation Example 7, the addition amount of ethylene oxide-modified sodium thiosulfate is 1.5 wt % of the natural rubber latex.

[0100] Example

[0101] Example 1

[0102] An artificial leather material based on the utilization of plant residue waste, the raw materials for its preparation are:

[0103] 200 g of the residue after pre-treatment tara tannin extraction, 100 g of an aqueous polyurethane emulsion, 100 g of a modified latex emulsion, 20 g of SM2140 silicone oil (DuPont, USA), and 30 g of a zinc oxide crosslinker (Mitsubishi Corporation, Japan). The residue after pre-treatment tara tannin extraction was prepared according to Example 1 for preparing the residue after pre-treatment tara tannin extraction, the aqueous polyurethane emulsion was prepared according to Example 1 for preparing the aqueous polyurethane emulsion, and the modified latex emulsion was prepared according to Example 1 for preparing the modified latex emulsion.

[0104] The preparation method of the above-mentioned artificial leather material is:

[0105] Step 1, the pre-treatment tara tannin of the above amount is extracted and the residue, aqueous polyurethane emulsion, modified latex emulsion, silicone oil and zinc oxide cross-linking agent are placed in DJR-3 type emulsification reactor to mix, start to be heated to 55 ℃ and stir at a low speed of 1000rpm, open high-speed homogenizer after temperature stabilization, specifically select RW20 digital mechanical stirrer (Germany IKA company), arranging stirring speed is 8000rpm, high-speed homogenization 15min, obtain uniform mixed solution. Subsequently, the mixed solution is subjected to ultrasonic dispersion in JP120ST ultrasonic homogenizer (Switzerland Branson company), specific ultrasonic frequency is 15kHz, power is 60%, and ultrasonic treatment time is 10min to be evenly dispersed, finally obtain raw material mixed solution.

[0106] Step 2: Heat the raw material mixture to 60° C. and then keep the mixture warm for 3 hours to obtain a composite emulsion.

[0107] Step 3, cooling the composite emulsion to 45° C., adding 0.2 wt % of an emulsifying agent Span-80, and continuing to stir and homogenize for 10 minutes, and finally adjusting the pH to 10-11, and stirring evenly to obtain an artificial leather material emulsion;

[0108] Step 4: After applying the obtained artificial leather material emulsion to the base fabric, the coating and drying steps are as follows:2 The coating amount was coated and then dried at 80°C; then the coating was dried at 80g / m 2 The coating was carried out in an amount of 1000 nm and then dried at a temperature of 120° C. An artificial leather material having a thickness of 0.84 mm was obtained.

[0109] Example 2

[0110] An artificial leather material based on the utilization of plant residue waste, the raw materials for its preparation are:

[0111] 250 g of the residue after pre-treatment tara tannin extraction, 120 g of an aqueous polyurethane emulsion, 200 g of a modified latex emulsion, 30 g of SM2140 silicone oil (DuPont, USA), and 40 g of a zinc oxide crosslinker (Mitsubishi Corporation, Japan). The residue after pre-treatment tara tannin extraction was prepared using the same method as in Example 2 for preparing the residue after pre-treatment tara tannin extraction, the aqueous polyurethane emulsion was prepared using the same method as in Example 2 for preparing the aqueous polyurethane emulsion, and the modified latex emulsion was prepared using the same method as in Example 2 for preparing the modified latex emulsion.

[0112] The preparation method of the above-mentioned artificial leather material is:

[0113] Step 1, the pre-treatment Tara tannin of above-mentioned amount is extracted after residue, aqueous polyurethane emulsion, modified latex emulsion, silicone oil and zinc oxide cross-linking agent are placed in DJR-3 type emulsification reactor and mixed, start to be heated to 60 ℃ and stir at a low speed with the speed of 1500rpm, open high-speed homogenizer after temperature stabilization, specifically select RW20 digital mechanical stirrer (Germany IKA company), arranging stirring speed is 10000rpm, high-speed homogenization 12min, obtains uniform mixed solution. Subsequently, mixed solution is carried out ultrasonic dispersion in JP120ST ultrasonic homogenizer (Switzerland Branson company), specific ultrasonic frequency is 20kHz, power is 65%, and ultrasonic treatment time is 8min to be evenly dispersed, finally obtains raw material mixed solution.

[0114] Step 2: Heat the raw material mixture to 70° C. and keep the mixture warm for 1.8 hours to obtain a composite emulsion.

[0115] Step 3, cooling the composite emulsion to 40° C., adding 0.25 wt % of an emulsifying agent Span-80, and continuing to stir and homogenize for 12 minutes, and finally adjusting the pH to 10-11, and stirring evenly to obtain an artificial leather material emulsion;

[0116] Step 4: After applying the obtained artificial leather material emulsion to the base fabric, the coating and drying steps are as follows: 2 The coating was applied at a coating weight of 100 g / m and then dried at a temperature of 120°C; then the coating was applied at a coating weight of 100 g / m 2 The coating amount was coated and then dried at 120 ° C; finally, the coating was dried at 100 g / m2 The coating was carried out in an amount of 1.50 and then dried at a temperature of 120° C. Finally, an artificial leather material with a thickness of 1.18 mm was obtained.

[0117] Example 3

[0118] An artificial leather material based on the utilization of plant residue waste, the raw materials for its preparation are:

[0119] 300 g of the residue after pre-treatment tara tannin extraction, 150 g of aqueous polyurethane emulsion, 300 g of modified latex emulsion, 40 g of SM2140 silicone oil (DuPont, USA), and 50 g of zinc oxide crosslinking agent (Mitsubishi Corporation, Japan). The residue after pre-treatment tara tannin extraction was prepared according to Preparation Example 3 of the residue after pre-treatment tara tannin extraction, the aqueous polyurethane emulsion was prepared according to Preparation Example 3 of the aqueous polyurethane emulsion, and the modified latex emulsion was prepared according to Preparation Example 3 of the modified latex emulsion.

[0120] The preparation method of the above-mentioned artificial leather material is:

[0121] Step 1, the pre-treatment tara tannin of the above amount is extracted and the residue, aqueous polyurethane emulsion, modified latex emulsion, silicone oil and zinc oxide cross-linking agent are placed in DJR-3 type emulsification reactor to mix, start to be heated to 65 ℃ and stir at a low speed of 2000rpm, open high-speed homogenizer after temperature stabilization, specifically select RW20 digital mechanical stirrer (Germany IKA company), arranging stirring speed is 12000rpm, high-speed homogenization 10min, obtain uniform mixed solution. Subsequently, the mixed solution is subjected to ultrasonic dispersion in JP120ST ultrasonic homogenizer (Switzerland Branson company), specific ultrasonic frequency is 25kHz, power is 55%, and ultrasonic treatment time is 5min to be evenly dispersed, finally obtain raw material mixed solution.

[0122] Step 2: Heat the raw material mixture to 80° C. and keep the mixture warm for 1.0 h to obtain a composite emulsion.

[0123] Step 3: Cool the composite emulsion to 40° C., add 0.30 wt % of an emulsifying agent Span-80, and continue stirring and homogenizing for 15 minutes. Finally, adjust the pH to 10-11, and stir evenly to obtain an artificial leather material emulsion.

[0124] Step 4: After applying the obtained artificial leather material emulsion to the base fabric, the coating and drying steps are as follows: 2 The coating was applied at a coating weight of 120 g / m and then dried at a temperature of 120 ° C; and then the coating was applied at a coating weight of 120 g / m 2 The coating was carried out in an amount of 1.000 mm and then dried at a temperature of 80° C. An artificial leather material having a thickness of 1.04 mm was finally obtained.

[0125] Examples 4-7

[0126] The difference between Examples 4-7 and Example 2 is that the sources of the modified latex emulsions are different; specifically, the modified latex emulsion of Example 4 is prepared from Modified Latex Emulsion Preparation Example 4, the modified latex emulsion of Example 5 is prepared from Modified Latex Emulsion Preparation Example 5, the modified latex emulsion of Example 6 is prepared from Modified Latex Emulsion Preparation Example 6, and the modified latex emulsion of Example 7 is prepared from Modified Latex Emulsion Preparation Example 7.

[0127] Examples 8-9

[0128] The difference between Example 8-9 and Example 2 is that the amount of modified latex emulsion added is different; specifically, the amount of modified latex emulsion added in Example 8 is 100 g, and the amount of modified latex emulsion added in Example 9 is 300 g.

[0129] Comparative Example

[0130] Comparative Examples 1-3

[0131] The difference between Comparative Examples 1-3 and Example 2 is that the amount of modified latex emulsion added is different; specifically, the amount of modified latex emulsion added in Comparative Example 1 is 0g, the amount of modified latex emulsion added in Comparative Example 2 is 50g, and the amount of modified latex emulsion added in Comparative Example 3 is 350g.

[0132] Comparative Example 4

[0133] The difference from Example 2 is that, when preparing the artificial leather material, the modified latex emulsion is replaced by an equal weight of latex emulsion, and the rest is the same as Example 2.

[0134] The preparation method of latex emulsion is as follows: deionized water and emulsifier methyl cellulose are added to SVR3 natural rubber latex imported from Malaysia (Bangkok Company), the amount of methyl cellulose added is 0.8wt% of the natural rubber latex, the pH is adjusted to 9-11, and an emulsification reaction is carried out: stirring at a speed of 400 rpm for 45 minutes at room temperature to obtain latex emulsion.

[0135] Comparative Example 5

[0136] The difference from Example 2 is that when preparing the artificial leather material, the raw materials do not contain water-based polyurethane emulsion, and the rest are the same as Example 2.

[0137] Comparative Example 6

[0138] This comparative example provides a conventional PU material (i.e., polyurethane artificial leather), and the product model is DZ-PU 20.

[0139] Performance testing

[0140] 1. The air permeability of the artificial leather material was tested using the methods in QB / T 2780-2006, "Polyurethane Artificial Leather for Shoe Uppers." The abrasion resistance of the artificial leather material was tested using the methods in QB / T 2780-2006, "Polyurethane Artificial Leather for Shoe Uppers." See Table 1 for the specific results.

[0141] Table 1 Air permeability of different artificial leather materials

[0142]

[0143]

[0144] As can be seen from the data results in Table 1, the artificial leather material prepared by the method of the present application has excellent air permeability compared with the polyurethane artificial leather of Comparative Example 6. In this solution, the artificial leather material with excellent air permeability is mainly obtained by modifying the epoxy resin.

[0145] The schemes of Example 2 and Examples 4-7 show that when preparing modified latex emulsion, the relative amounts of ethylene oxide-modified sodium thiosulfate and natural rubber are relatively important: when the addition amount of ethylene oxide-modified sodium thiosulfate is 0.5-1.2wt% of natural rubber latex, the air permeability of the obtained artificial leather material is considerably better.

[0146] Embodiment 2, embodiment 8-9 and comparative example 2-3 illustrate, when preparing artificial leather material, the addition of modified latex emulsion in the scope of 10-30 weight portion (i.e. corresponding to the 100-300g in the specific embodiment), all can obtain the artificial leather material of excellent air permeability.The addition of modified latex emulsion is larger on the air permeability impact of artificial leather material, what affects on the one hand is the air permeability of artificial leather material, also affects the binding stability of latex emulsion and pre-treatment plant residue on the other hand.And do not add modified latex emulsion in comparative example 1 or comparative example 4 without epoxy-modified latex emulsion, the air permeability of artificial leather material will be significantly reduced.

[0147] In Comparative Example 5, not adding water-based polyurethane when preparing the artificial leather material will also directly lead to a decrease in the material's air permeability. The main reason for this is that water-based polyurethane gives the artificial leather material good flexibility and elasticity, and it can form a continuous but non-completely closed coating on the surface of the artificial leather. This coating helps to increase the pore density of the artificial leather material, thereby improving its air permeability. In addition, water-based polyurethane has good hydrophilicity and can absorb surrounding moisture and evaporate it, so that the artificial leather can maintain good air permeability even in a humid environment. In addition, traditional artificial leather materials are prepared using solvent-based polyurethane, which will result in a closed leather texture and poor air permeability; while water-based polyurethane is soluble in water and can form more micropores in the prepared artificial leather material, thereby improving the air permeability of the artificial leather. Therefore, the air permeability of the artificial leather material prepared using the raw materials of Comparative Example 5 is significantly reduced.

[0148] 2. Refer to the method of QB / T 2780-2006 "Polyurethane Artificial Leather for Shoe Uppers" to test the tensile strength of the artificial leather material, refer to the method of QB / T 2780-2006 "Polyurethane Artificial Leather for Shoe Uppers" to test the tear strength of the artificial leather material, and refer to the method of QB / T 2780-2006 "Polyurethane Artificial Leather for Shoe Uppers" to test the adhesive strength of the artificial leather material.

[0149] Table 2 Tensile strength, tear strength, adhesive strength and abrasion resistance of different artificial leather materials

[0150]

[0151]

[0152] From the data results in Table 2, it can be seen that, compared with the materials of Example 2 and Comparative Example 6, the artificial leather material obtained in the present application has excellent air permeability, certain wear resistance, and more excellent tensile strength, tear strength and bonding strength.

[0153] Comparing the results of Example 2 with Comparative Example 1, adding the modified latex emulsion during the preparation of the artificial leather material results in a certain degree of reduction in tensile strength, tear strength, and adhesive strength of the obtained artificial leather material, but an improvement in abrasion resistance. Without the addition of the modified latex emulsion, the artificial leather material becomes more compact, resulting in the aforementioned changes in the above properties. However, overall, the performance is still better than that of the polyurethane material of Comparative Example 6.

[0154] When the modified latex emulsion used in the preparation of the raw material is replaced with latex emulsion in Comparative Example 4, the obtained artificial leather material has lower tensile strength, tear strength and bonding strength than that of Example 2, but the wear resistance is significantly improved; the reason for the improved wear resistance is that when there is no epoxy group involved in the reaction, the density of the artificial leather material is higher, thereby improving the wear resistance.

[0155] In contrast, the absence of waterborne polyurethane in the preparation of the artificial leather material in Comparative Example 5 not only directly impacted the breathability of the artificial leather material but also significantly reduced its tensile strength, tear strength, and adhesive strength. This may be due to the lack of waterborne polyurethane, which directly affected the interactions of the various raw materials, the network structure formed after the reaction, and the bonding stability.

[0156] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. An artificial leather material based on the utilization of plant residue waste, characterized in that: The invention comprises the following raw materials in parts by weight: 20-30 parts of pretreated plant residues, 10-15 parts of waterborne polyurethane emulsion, 10-30 parts of modified latex emulsion, 2-4 parts of silicone oil, and 3-5 parts of crosslinking agent; The modified latex emulsion is obtained by epoxy-modifying latex, and the preparation method of the modified latex emulsion comprises the following steps: Step 1: mixing rubber latex and epoxy reagent to obtain a premixed solution; wherein the epoxy reagent is added in an amount of 0.5-1.2% by weight of the rubber latex; Step II: adding an emulsifier to the premixed liquid, adjusting the pH to 9-11, and performing an emulsification reaction to obtain a modified latex emulsion; the epoxy reagent is selected from any one or more of ethylene oxide-modified sodium thiosulfate and epichlorohydrin.

2. The artificial leather material based on the utilization of plant residue waste according to claim 1, characterized in that: The amount of the emulsifier added is 0.6-0.9% by weight of the premix.

3. The artificial leather material based on the utilization of plant residue waste according to claim 1, characterized in that: The preparation method of the pretreated plant residue comprises the following steps: Step 1: Dispersing and homogenizing the plant residue to obtain residue particles; Step ②, soaking the residue particles in alkali solution, reacting, and then microwave-treating to obtain a refined residue; Step ③: The refined residue is washed and dried to obtain the pretreated plant residue.

4. The artificial leather material based on the utilization of plant residue waste according to claim 3, characterized in that: In step ①, the particle size of the residue particles obtained is 150-200 mesh.

5. The artificial leather material based on the utilization of plant residue waste according to claim 3, characterized in that: In step ②, the microwave treatment conditions include: treatment time of 10-15 min, microwave frequency of 2200-2600 MHz, and power of 300-500 W.

6. A method for preparing an artificial leather material based on the utilization of plant residue waste according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: Step 1: mixing pretreated plant residues, aqueous polyurethane emulsion, modified latex emulsion, silicone oil and a crosslinking agent, and dispersing them uniformly to obtain a raw material mixture; Step 2, heating the raw material mixture and then keeping it warm for reaction to obtain a composite emulsion; Step 3, cooling the composite emulsion, homogenizing, adjusting the pH to 10-11, and stirring evenly to obtain an artificial leather material emulsion; Step 4: coating the artificial leather material emulsion on a base fabric and drying the base fabric to obtain the artificial leather material.

7. The method for preparing artificial leather material based on the utilization of plant residue waste according to claim 6, characterized in that: The uniform dispersion in step 1 specifically includes the steps of high-speed homogenization and ultrasonic homogenization; The conditions for high-speed homogenization include: a stirring speed of 8000-12000 rpm and a stirring time of 10-15 min; The ultrasonic homogenization conditions include: ultrasonic frequency of 15-25 kHz, and ultrasonic time of 5-10 min.

8. The method for preparing artificial leather material based on the utilization of plant residue waste according to claim 6, characterized in that: In step 2, the heating temperature is 60-80° C., and the insulation reaction time is 1-3 hours.

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