Lightweight, high-density leather for labor protection shoes, preparation method and application thereof

Abstract

The application discloses light high-density leather for labor protection shoes and a preparation method and application thereof, and relates to the technical field of labor protection shoes. The light high-density leather for labor protection shoes comprises a polyurethane surface layer, a viscose layer, an aluminum foil layer, a broken adhesive layer and a bottom base. The aluminum foil layer is provided with a plurality of array-distributed through holes, and the corresponding part of the viscose layer or the broken adhesive layer passes through the through holes. The viscose layer comprises 60-100 parts by weight of polyester polyol, 30-50 parts by weight of diphenyl methane diisocyanate, 17-30 parts by weight of phthalic anhydride, 10-20 parts by weight of ethylene glycol, 1-3 parts by weight of epoxy resin, 0.1-1 part by weight of methanol, 0.1-3 parts by weight of polycarbonate dihydric alcohol and 0.01-3 parts by weight of zinc oxide. The broken adhesive layer is composed of broken layers dispersed in a semi-cured adhesive layer. The application realizes the connection and support of the polyurethane surface layer and the bottom base through the aluminum foil and the viscose layer and the broken adhesive layer. The viscose layer and the broken adhesive layer intersecting through the through holes form a high-density polymer crosslinking network structure, so that the purpose of improving the structural strength and prolonging the service life is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of labor protection shoes, and in particular to a lightweight, high-density leather for labor protection shoes, and a preparation method and application thereof. Background Art

[0002] Genuine leather is the best choice for shoe leather. Genuine leather is a natural material composed of tightly woven collagen fibers, offering advantages such as a pleasant feel and excellent water vapor permeability. However, genuine leather is susceptible to contamination during its production process, leading to excessive levels of heavy metals and low yield rates during processing. This leads to high costs and poor consumer acceptance. Therefore, artificial leather has emerged. Artificial leather not only addresses the cleanliness and cost issues of genuine leather but also achieves environmentally friendly, energy-saving, and sustainable development goals, avoiding harm to animals and damage to the natural environment.

[0003] Chinese patent application publication number CN109972414A discloses a method for processing ultralight simulated leather microfiber synthetic leather. The method comprises the following steps: ① manufacturing a base fabric: mixing PA chips and PE chips through a spinning process to produce nylon blended island-in-the-sea fibers; ② needle-punching the prepared nylon blended island-in-the-sea fibers to produce a microfiber non-woven fabric; ③ shaping the microfiber non-woven fabric to achieve a desired thickness and weight, thereby completing the production of the base fabric; ④ wet-impregnating the microfiber non-woven fabric to produce an unopened semi-finished product; ⑤ opening the semi-finished product using a benzene reduction method to obtain a opened semi-finished product; ⑥ drying the opened semi-finished product, applying oil to set the shape, and kneading the leather; ⑦ hot kneading the kneaded semi-finished product in a hot kneading machine; ⑧ applying resin to the kneaded semi-finished product to obtain the ultralight simulated leather microfiber synthetic leather.

[0004] However, the ultra-light simulated leather microfiber synthetic leather obtained by this processing method has poor structural strength, resulting in weak hydrolysis resistance and short service life due to cracking and powdering, which needs to be improved. Summary of the Invention

[0005] In view of this, the first object of this application is to provide a lightweight, high-density leather for labor protection shoes to achieve the purpose of improving structural strength and extending service life. The specific solution is as follows:

[0006] A lightweight, high-density leather for labor protection shoes, comprising a polyurethane surface layer, an adhesive layer, an aluminum foil layer, a crushable adhesive layer, and a bottom base; the aluminum foil layer is provided with a plurality of through holes distributed in an array, through which the adhesive layer or corresponding portions of the crushable adhesive layer pass; the adhesive layer comprises, by weight, 60-100 parts of polyester polyol, 30-50 parts of diphenylmethane diisocyanate, 17-30 parts of phthalic anhydride, 10-20 parts of ethylene glycol, 1-3 parts of epoxy resin, 0.1-1 part of methanol, 0.1-3 parts of polycarbonate diol, and 0.01-3 parts of zinc oxide; the crushable adhesive layer is composed of a crushable layer dispersed in a semi-cured adhesive layer.

[0007] Preferably, the polyurethane surface layer comprises, by weight, 50-80 parts of polyurethane resin, 0.1-3 parts of antioxidant, 0.1-5 parts of curing agent and 0-3 parts of color paste.

[0008] Preferably, the antioxidant is antioxidant V76-P, and the curing agent is polyisocyanate trimer HTBL-175S purchased from Wanhua.

[0009] Preferably, the crushing layer is formed by mixing and solidifying a glue solution comprising 16-24 parts by weight of vinyl acetate, 22-28 parts of butyl rubber, 7-12 parts of polyethylene, 0.01-2 parts of graphene, 0.01-1 parts of antioxidant, 0.5-1 parts of epoxy resin and 0.5-1 parts of calcium carbonate.

[0010] Preferably: the polyethylene is linear low density polyethylene, and the antioxidant is a phenol-free phosphite antioxidant 3010.

[0011] Preferably, the semi-cured adhesive layer is formed by curing a light / heat curing adhesive.

[0012] Preferably: the light / heat curing adhesive comprises a binary or multi-component copolymer of ethylene containing active groups and propylene, butene, pentene, hexene, octene, butadiene, 1,4-pentadiene, isoprene, ethylidene norbornene, dicyclopentadiene, 1,4-hexadiene as a base resin, ethylene glycol, a silane coupling agent, tert-butyl peroxyisopropyl carbonate and N,N-dimethylcyclohexylamine, and the weight ratio is 70-98:0.05-10:0.01-2:0.01-2:0.01-2.

[0013] The second object of the present application is to provide a method for preparing a lightweight, high-density leather for labor protection shoes as described above, comprising the following steps:

[0014] Step 1: Apply polyurethane surface layer slurry on release paper to control the coating thickness to 0.05-0.2 mm, and obtain the polyurethane surface layer after drying;

[0015] Step 2: Evenly apply adhesive on the polyurethane surface layer to a thickness of 0.1-0.2 mm, and dry it by 20-80% to obtain an adhesive surface layer;

[0016] Step 3: Attach the laminated substrate to the adhesive surface layer, peel off the release paper after drying, and obtain a lightweight and high-density leather for labor protection shoes.

[0017] Preferably, in step 3, the laminating substrate is composed of an aluminum foil layer, a crushing layer, a semi-cured adhesive layer, and a bottom base fabric; the bottom base fabric is a fiber woven fabric or a non-woven fabric; the aluminum foil layer has a thickness of 0.05-0.1 mm and is laser-perforated; the crushing layer is formed by mixing and curing an adhesive solution comprising 16-24 parts by weight of vinyl acetate, 22-28 parts of butyl rubber, 7-12 parts of polyethylene, 0.01-2 parts of graphene, 0.01-1 parts of antioxidant, 0.5-1 parts of epoxy resin, and 0.5-1 parts of calcium carbonate; and the semi-cured adhesive layer is formed by curing a light / heat curing adhesive.

[0018] The third object of the present application is to provide the application of the lightweight and high-density leather for labor protection shoes as described above in labor protection shoe uppers.

[0019] Through the above scheme, it can be seen that the present application provides a lightweight, high-density leather for labor protection shoes, and its preparation method and application. The lightweight, high-density leather for labor protection shoes realizes the connection and support of the polyurethane surface layer and the bottom base through aluminum foil, an adhesive layer and a crushed adhesive layer. The adhesive layer and the crushed adhesive layer intersecting through the through holes form a high-density polymer cross-linked network structure, achieving the purpose of improving structural strength and extending service life. The preparation method of the lightweight, high-density leather for labor protection shoes has the function of effectively obtaining a crushed adhesive layer composed of a crushed layer dispersed in a semi-cured adhesive layer, and cross-linking and curing the crushed adhesive layer with the adhesive layer to achieve the purpose of effectively improving structural strength. The application of the lightweight, high-density leather for labor protection shoes in labor protection shoe uppers plays a role in significantly improving the service life of labor protection shoe uppers and effectively avoiding cracking and powdering. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without any creative work.

[0021] Figure 1 This is a schematic structural diagram of the lightweight, high-density leather for labor protection shoes disclosed in this application.

[0022] Reference signs: 1, polyurethane surface layer; 2, adhesive layer; 3, aluminum foil layer; 31, through hole; 4, broken adhesive layer; 5, bottom base. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0024] It should be mentioned that the phenol-free phosphite antioxidant 3010 is purchased from Guangzhou Zhiyi Chemical Co., Ltd. The polyisocyanate trimer HTBL-175S is purchased from Wanhua Chemical.

[0025] The following will be specifically described for the light high-density labor protection shoe leather and its preparation method and application.

[0026] As Figure 1 shown, a light high-density labor protection shoe leather includes a polyurethane surface layer 1, an adhesive layer 2, an aluminum foil layer 3, a broken adhesive layer 4, and a bottom base 5. The broken adhesive layer 4 is composed of a broken layer dispersed in a semi-cured adhesive layer. The broken layer has adhesion and, when not broken, has the effect of connecting the aluminum foil layer 3 and the semi-cured adhesive layer, forms a combined structure with the semi-cured adhesive layer in the aluminum foil layer 3 working operation, and is used to form the broken adhesive layer 4 after complete curing.

[0027] It should be mentioned that a plurality of arrayed through holes 31 are provided on the aluminum foil layer 3. The corresponding parts of the adhesive layer 2 and the broken adhesive layer 4 pass through the through holes 31 and are cross-linked and cured with the corresponding broken adhesive layer 4 and adhesive layer 2. In the embodiments of the present application, the polyurethane surface layer 1 includes 50-80 parts by weight of polyurethane resin, 0.1-3 parts of antioxidant, 0.1-5 parts of curing agent, and 0-3 parts of color paste. The adhesive layer 2 includes 60-100 parts by weight of polyester polyol, 30-50 parts of diphenyl methane diisocyanate, 17-30 parts of phthalic anhydride, 10-20 parts of ethylene glycol, 1-3 parts of epoxy resin, 0.1-1 parts of methanol, 0.1-3 parts of polycarbonate diol, and 0.01-3 parts of zinc oxide. The broken layer is formed by mixing and curing the glue solution including 16-24 parts by weight of vinyl acetate, 22-28 parts of butyl rubber, 7-12 parts of polyethylene, 0.01-2 parts of graphene, 0.01-1 parts of antioxidant, 0.5-1 parts of epoxy resin, and 0.5-1 parts of calcium carbonate.

[0028] Among them, the antioxidant used in the embodiment of the present application is antioxidant V76-P, the curing agent is polyisocyanate trimer HTBL-175S purchased from Wanhua, the polyethylene is linear low-density polyethylene, and the antioxidant is phenol-free phosphite antioxidant 3010. The semi-cured adhesive layer is formed by curing the light / heat curing adhesive.

[0029] It should be noted that the light / heat curing adhesive comprises a binary or multi-component copolymer of ethylene containing reactive groups and propylene, butene, pentene, hexene, octene, butadiene, 1,4-pentadiene, isoprene, ethylidene norbornene, dicyclopentadiene, or 1,4-hexadiene as a base resin, ethylene glycol, a silane coupling agent, tert-butyl peroxyisopropyl carbonate, and N,N-dimethylcyclohexylamine, with the weight ratio being 70-98 parts: 0.05-10 parts: 0.01-2 parts: 0.01-2 parts: 0.01-2 parts. The reactive groups are isocyanate groups or acyl chloride groups.

[0030] A method for preparing lightweight and high-density leather for labor protection shoes comprises the following steps:

[0031] Step 1: Apply polyurethane surface layer 1 slurry on release paper to control the coating thickness to 0.05-0.2 mm, and obtain polyurethane surface layer 1 after drying;

[0032] Step 2: Evenly apply adhesive on the polyurethane surface layer 1, controlling the coating thickness to be 0.1-0.2 mm, and drying it by 20-80% to obtain an adhesive surface layer;

[0033] Step 3: attach the laminated substrate to the adhesive surface layer, perform infrared or high temperature treatment, and peel off the release paper after drying to obtain a lightweight and high-density leather for labor protection shoes.

[0034] Regarding the bonding substrate in step 3, the bonding substrate in the embodiment of the present application is composed of an aluminum foil layer 3, a crushing layer, a semi-cured adhesive layer and a bottom base fabric. The bottom base fabric used is a fiber woven cloth or a non-woven fabric. The thickness of the aluminum foil layer 3 is 0.05-0.1mm, and it is laser-perforated to achieve the effect of crushing the crushing layer and impacting into the semi-cured adhesive layer. The crushing layer is formed by mixing and curing a glue solution comprising 16-24 parts by weight of vinyl acetate, 22-28 parts of butyl rubber, 7-12 parts of polyethylene, 0.01-2 parts of graphene, 0.01-1 parts of antioxidant, 0.5-1 parts of epoxy resin and 0.5-1 parts of calcium carbonate.

[0035] The application of lightweight and high-density leather for labor protection shoes in labor protection shoe uppers can significantly increase the service life of the labor protection shoe uppers and effectively avoid cracking and powdering.

[0036] Example 1

[0037] like Figure 1As shown, a kind of light high-density leather for safety shoes includes polyurethane surface layer 1, viscose layer 2, aluminum foil layer 3, broken adhesive layer 4 and bottom layer base 5. Among them, broken adhesive layer 4 is composed of broken layer dispersed in semi-cured glue layer. Broken layer has adhesive force, and has the effect of connecting aluminum foil layer 3 and semi-cured glue layer when not broken, forms combined structure with semi-cured glue layer in aluminum foil layer 3 working operation, and is used to form broken adhesive layer 4 after complete curing.

[0038] Need to mention is that a plurality of array distribution through holes 31 are provided on aluminum foil layer 3. Among them, the corresponding part of viscose layer 2 and broken adhesive layer 4 passes through through hole 31 and is crosslinked and cured with corresponding broken adhesive layer 4 and viscose layer 2. In the embodiment of the application, polyurethane surface layer 1 includes 50 parts by weight of polyurethane resin, 0.1 part of antioxidant and 0.1 part of curing agent. Viscose layer 2 includes 60 parts by weight of polyester polyol, 30 parts of diphenyl methane diisocyanate, 17 parts of phthalic anhydride, 10 parts of ethylene glycol, 1 part of epoxy resin, 0.1 part of methanol, 0.1 part of polycarbonate diol and 0.01 part of zinc oxide. Broken layer is formed by mixing and curing glue solution including 16 parts by weight of vinyl acetate, 22 parts of butyl rubber, 7 parts of polyethylene, 0.01 part of graphene, 0.01 part of antioxidant, 0.5 part of epoxy resin and 0.5 part of calcium carbonate.

[0039] Among them, the antioxidant used in the embodiment of the application is antioxidant V76-P, the curing agent is polyisocyanate trimer HTBL-175S purchased from Wanhua, the polyethylene is linear low density polyethylene, and the antioxidant is a non-phenolic phosphite antioxidant 3010. Semi-cured glue layer is formed by curing light / heat curing glue.

[0040] Need to mention is that light / heat curing glue includes multi-polymer of ethylene and propylene, butylene containing active groups as matrix resin, ethylene glycol, silane coupling agent, tert-butyl peroxide isopropyl carbonate and N, N-dimethylcyclohexylamine, and the weight ratio is 70:0.05:0.01:0.01:0.01. Active group is isocyanate group.

[0041] A kind of light high-density leather for safety shoes is prepared by the following steps:

[0042] Step 1, polyurethane surface layer 1 slurry is coated on release paper, the coating thickness is controlled to be 0.05mm, and polyurethane surface layer 1 is obtained after drying;

[0043] Step 2, uniformly coat viscose on polyurethane surface layer 1, control the coating thickness to be 0.1mm, after preliminary drying, viscose surface layer is obtained;

[0044] Step 3: attach the laminated substrate to the adhesive surface layer, perform infrared or high temperature treatment, and peel off the release paper after drying to obtain a lightweight and high-density leather for labor protection shoes.

[0045] Regarding the bonding substrate in step 3, the bonding substrate in the embodiment of the present application is composed of an aluminum foil layer 3, a crushing layer, a semi-cured adhesive layer and a bottom base fabric. The bottom base fabric used is a fiber woven cloth. The thickness of the aluminum foil layer 3 is 0.05mm, and it is laser-perforated to achieve the effect of crushing the crushing layer and impacting into the semi-cured adhesive layer. The laser opening spacing can be 0.05mm-0.2mm, and the speed, Q frequency and other parameters are set according to demand, which will not be elaborated here. And in Example 1 of the present application, 0.05mm spacing, 600mm / s marking speed, 20KHzQ frequency and 40% power are mainly used.

[0046] At the same time, the present application also discloses the application of a lightweight, high-density leather for labor protection shoes in labor protection shoe uppers, which significantly improves the service life of the labor protection shoe uppers and effectively avoids cracking and powdering.

[0047] Example 2

[0048] like Figure 1 As shown, a lightweight, high-density leather for labor protection shoes comprises a polyurethane surface layer 1, an adhesive layer 2, an aluminum foil layer 3, a crushable adhesive layer 4, and a base layer 5. The crushable adhesive layer 4 is composed of a crushable layer dispersed within a semi-cured adhesive layer. The crushable layer has adhesive strength and, when uncrushed, connects the aluminum foil layer 3 and the semi-cured adhesive layer. During the processing of the aluminum foil layer 3, it forms a combined structure bonded to the semi-cured adhesive layer and, after complete curing, forms the crushable adhesive layer 4.

[0049] It should be mentioned that a plurality of through holes 31 distributed in an array are provided on the aluminum foil layer 3. The corresponding parts of the adhesive layer 2 and the broken adhesive layer 4 pass through the through holes 31 and are cross-linked and cured with the corresponding broken adhesive layer 4 and the adhesive layer 2. In an embodiment of the present application, the polyurethane surface layer 1 includes 70 parts by weight of a polyurethane resin, 1 part of an antioxidant, 2 parts of a curing agent and 1 part of a color paste. The adhesive layer 2 includes 80 parts by weight of a polyester polyol, 40 parts of diphenylmethane diisocyanate, 20 parts of phthalic anhydride, 15 parts of ethylene glycol, 2 parts of an epoxy resin, 0.4 parts of methanol, 0.8 parts of a polycarbonate diol and 1 part of zinc oxide. The crushing layer is formed by mixing and solidifying a glue solution comprising 22 parts by weight of vinyl acetate, 25 parts of butyl rubber, 10 parts of polyethylene, 1 part of graphene, 0.3 parts of antioxidant, 0.7 parts of epoxy resin and 0.6 parts of calcium carbonate.

[0050] Among them, the antioxidant used in the embodiment of the present application is antioxidant V76-P, the curing agent is polyisocyanate trimer HTBL-175S purchased from Wanhua, the polyethylene is linear low-density polyethylene, and the antioxidant is phenol-free phosphite antioxidant 3010. The semi-cured adhesive layer is formed by curing the light / heat curing adhesive.

[0051] It should be noted that the light / heat curing adhesive comprises a base resin (a binary copolymer of ethylene, octene, butadiene, and isoprene) containing reactive groups, ethylene glycol, a silane coupling agent, tert-butyl peroxyisopropyl carbonate, and N,N-dimethylcyclohexylamine in a weight ratio of 78:3:1:0.8:1.4. The reactive groups are acyl chloride groups.

[0052] A method for preparing lightweight and high-density leather for labor protection shoes comprises the following steps:

[0053] Step 1: coating a polyurethane surface layer 1 slurry on a release paper, controlling the coating thickness to be 0.1 mm, and obtaining a polyurethane surface layer 1 after drying;

[0054] Step 2: Evenly apply adhesive on the polyurethane surface layer 1, controlling the coating thickness to be 0.15 mm, and obtain an adhesive surface layer after preliminary drying;

[0055] Step 3: attach the laminated substrate to the adhesive surface layer, perform infrared or high temperature treatment, and peel off the release paper after drying to obtain a lightweight and high-density leather for labor protection shoes.

[0056] Regarding the bonding substrate in step 3, the bonding substrate in the embodiment of the present application is composed of an aluminum foil layer 3, a crushing layer, a semi-cured adhesive layer and a bottom base fabric. The bottom base fabric used is a non-woven fabric. The thickness of the aluminum foil layer 3 is 0.08 mm, and it is laser-perforated to achieve the effect of crushing the crushing layer and impacting into the semi-cured adhesive layer. The laser opening spacing can be 0.05 mm-0.2 mm, and the speed, Q frequency and other parameters are set according to demand, which will not be elaborated here. In Example 2 of the present application, 0.1 mm spacing, 600 mm / s marking speed, 20 KHz Q frequency and 37% power are mainly used.

[0057] At the same time, the present application also discloses the application of a lightweight, high-density leather for labor protection shoes in labor protection shoe uppers, which significantly improves the service life of the labor protection shoe uppers and effectively avoids cracking and powdering.

[0058] Example 3

[0059] like Figure 1As shown, a lightweight, high-density leather for labor protection shoes comprises a polyurethane surface layer 1, an adhesive layer 2, an aluminum foil layer 3, a crushable adhesive layer 4, and a base layer 5. The crushable adhesive layer 4 is composed of a crushable layer dispersed within a semi-cured adhesive layer. The crushable layer has adhesive strength and, when uncrushed, connects the aluminum foil layer 3 and the semi-cured adhesive layer. During the processing of the aluminum foil layer 3, it forms a combined structure bonded to the semi-cured adhesive layer and, after complete curing, forms the crushable adhesive layer 4.

[0060] It should be mentioned that a plurality of through holes 31 distributed in an array are provided on the aluminum foil layer 3. Among them, the corresponding parts of the adhesive layer 2 and the broken adhesive layer 4 pass through the through holes 31 and are cross-linked and cured with the corresponding broken adhesive layer 4 and the adhesive layer 2. In the embodiment of the present application, the polyurethane surface layer 1 includes 80 parts by weight of polyurethane resin, 3 parts of antioxidant, 5 parts of curing agent and 3 parts of color paste. The adhesive layer 2 includes 100 parts by weight of polyester polyol, 50 parts of diphenylmethane diisocyanate, 30 parts of phthalic anhydride, 20 parts of ethylene glycol, 3 parts of epoxy resin, 1 part of methanol, 3 parts of polycarbonate diol and 3 parts of zinc oxide. The broken layer is formed by mixing and curing a glue solution including 24 parts by weight of vinyl acetate, 28 parts of butyl rubber, 12 parts of polyethylene, 2 parts of graphene, 1 part of antioxidant, 1 part of epoxy resin and 1 part of calcium carbonate.

[0061] Among them, the antioxidant used in the embodiment of the present application is antioxidant V76-P, the curing agent is polyisocyanate trimer HTBL-175S purchased from Wanhua, the polyethylene is linear low-density polyethylene, and the antioxidant is phenol-free phosphite antioxidant 3010. The semi-cured adhesive layer is formed by curing the light / heat curing adhesive.

[0062] It should be noted that the light / heat curing adhesive comprises a multi-component copolymer of ethylene and 1,4-hexadiene containing reactive groups as a base resin, ethylene glycol, a silane coupling agent, tert-butyl peroxyisopropyl carbonate, and N,N-dimethylcyclohexylamine, with the weight ratio being 98:10:2:2:2. The reactive groups are isocyanate groups.

[0063] A method for preparing lightweight and high-density leather for labor protection shoes comprises the following steps:

[0064] Step 1: Apply polyurethane surface layer 1 slurry on release paper to a coating thickness of 0.2 mm, and obtain polyurethane surface layer 1 after drying;

[0065] Step 2: Evenly apply adhesive on the polyurethane surface layer 1, controlling the coating thickness to be 0.2 mm, and obtain an adhesive surface layer after preliminary drying;

[0066] Step 3: attach the laminated substrate to the adhesive surface layer, perform infrared or high temperature treatment, and peel off the release paper after drying to obtain a lightweight and high-density leather for labor protection shoes.

[0067] With respect to the bonding substrate in step 3, the bonding substrate in the embodiment of the present application is composed of an aluminum foil layer 3, a crushing layer, a semi-cured adhesive layer and a bottom base fabric. The bottom base fabric used is a fiber woven cloth or a non-woven fabric. The thickness of the aluminum foil layer 3 is 0.1 mm, and it is laser-perforated to achieve the effect of crushing the crushing layer and impacting into the semi-cured adhesive layer. The laser opening spacing can be 0.05 mm-0.2 mm, and the speed, Q frequency and other parameters are set according to the requirements, which will not be elaborated here. And in Example 3 of the present application, 0.2 mm spacing, 800 mm / s marking speed, 20 KHz Q frequency and 38% power are mainly used.

[0068] At the same time, the present application also discloses the application of a lightweight, high-density leather for labor protection shoes in labor protection shoe uppers, which significantly improves the service life of the labor protection shoe uppers and effectively avoids cracking and powdering.

[0069] Example 4

[0070] The difference between Example 4 and Example 2 is that the graphene used in the crushing layer in Example 4 is activated graphene treated with sodium hydroxide solution with a pH of 2-3.

[0071] Comparative Example 1

[0072] The difference between Comparative Example 1 and Example 2 is that the lightweight high-density leather for labor protection shoes in Comparative Example 1 includes a polyurethane surface layer 1, an adhesive layer 2, a crushable adhesive layer 4 and a bottom base 5.

[0073] Comparative Example 2

[0074] The difference between Comparative Example 2 and Example 2 is that the aluminum foil layer 3 in Comparative Example 2 does not have the through hole 31 .

[0075] Comparative Example 3

[0076] The difference between Comparative Example 3 and Example 2 is that the crushable adhesive layer 4 in Comparative Example 3 is formed by directly curing the semi-cured adhesive layer.

[0077] Comparative Example 4

[0078] The difference between Comparative Example 4 and Example 2 is that the semi-cured adhesive layer in Comparative Example 4 is a double-sided adhesive without a substrate.

[0079] Comparative Example 5

[0080] The difference between Comparative Example 5 and Example 2 is that the crushing layer in Comparative Example 5 does not have graphene.

[0081] Performance testing:

[0082] 1. Mechanical strength: breaking strength, peel strength and warp tear strength

[0083] 2. Hydrolysis resistance: Tested at 70°C and 95% relative humidity for 5 weeks.

[0084] The performance test results are shown in Table 1 below:

[0085] Table 1 Performance test results of Examples 1 to 4 and Comparative Examples 1 to 5

[0086]

[0087]

[0088] As can be seen from Table 1 above, the lightweight, high-density leather for safety shoes of this application is resistant to alcohol and hydrolysis, with a peel strength greater than 45N / 3cm, a breaking strength greater than 600N / cm, and a warp tear strength greater than 100N. Compared to existing materials, it has significantly improved mechanical properties and meets the requirements for hydrolysis resistance.

[0089] In addition, compared with Comparative Examples 1 to 5, the lightweight and high-density leather for labor protection shoes in the embodiment of the present application has a five-layer structure consisting of a polyurethane surface layer, an adhesive layer, an aluminum foil layer, a crushable adhesive layer and a bottom base. While the aluminum foil layer plays an effective supporting role, the crushable layer is crushed when a through hole is opened on the aluminum foil layer and combined with the semi-cured adhesive layer to form a crushed adhesive layer with significantly improved structural strength after complete curing, thereby achieving the purpose of improving peel strength and mechanical strength.

[0090] In summary, the present application provides a lightweight, high-density leather for labor protection shoes, and its preparation method and application. The lightweight, high-density leather for labor protection shoes realizes the connection and support of the polyurethane surface layer and the bottom base through aluminum foil, an adhesive layer, and a crushed adhesive layer. The adhesive layer and the crushed adhesive layer intersecting through the through holes form a high-density polymer cross-linked network structure, so that the wear resistance and hydrolysis resistance are significantly improved by improving the composite performance, thereby achieving the purpose of improving structural strength and extending service life. The preparation method of the lightweight, high-density leather for labor protection shoes has the advantages of effectively obtaining a crushed adhesive layer composed of a crushed layer dispersed in a semi-cured adhesive layer, and cross-linking and curing the crushed adhesive layer with the adhesive layer to achieve the purpose of effectively improving structural strength.

[0091] References to "first," "second," "third," "fourth," and the like (if any) herein are intended to distinguish similar objects and are not necessarily intended to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions, e.g., a process, method, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, or apparatus.

[0092] It should be noted that the descriptions of "first", "second", etc. in this application are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0093] This document uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A lightweight, high-density leather for labor protection shoes, characterized by: The invention comprises a polyurethane surface layer, an adhesive layer, an aluminum foil layer, a crushable adhesive layer and a bottom base; the aluminum foil layer is provided with a plurality of through holes distributed in an array, and the adhesive layer or the corresponding part of the crushable adhesive layer passes through the through holes; the adhesive layer comprises 60-100 parts by weight of polyester polyol, 30-50 parts by weight of diphenylmethane diisocyanate, 17-30 parts by weight of phthalic anhydride, 10-20 parts by weight of ethylene glycol, 1-3 parts by weight of epoxy resin, 0.1-1 parts by weight of methanol, 0.1-3 parts by weight of polycarbonate Ester diol and 0.01-3 parts of zinc oxide; the crushing adhesive layer is composed of a crushing layer dispersed in a semi-cured adhesive layer; wherein the crushing layer is formed by mixing and curing an adhesive solution including 16-24 parts by weight of vinyl acetate, 22-28 parts of butyl rubber, 7-12 parts of polyethylene, 0.01-2 parts of graphene, 0.01-1 parts of antioxidant, 0.5-1 parts of epoxy resin and 0.5-1 parts of calcium carbonate; the semi-cured adhesive layer is formed by curing a light / heat curing adhesive.

2. The lightweight, high-density leather for labor protection shoes according to claim 1, characterized in that: The polyurethane surface layer comprises 50-80 parts by weight of polyurethane resin, 0.1-3 parts by weight of antioxidant, 0.1-5 parts by weight of curing agent and 0-3 parts by weight of color paste.

3. The lightweight, high-density leather for labor protection shoes according to claim 2, characterized in that: The antioxidant is antioxidant V76-P, and the curing agent is polyisocyanate trimer HTBL-175S purchased from Wanhua.

4. The lightweight, high-density leather for labor protection shoes according to claim 1, characterized in that: The polyethylene is linear low-density polyethylene, and the antioxidant is phenol-free phosphite antioxidant YIPHOS® 3010.

5. The lightweight, high-density leather for labor protection shoes according to claim 1, characterized in that: The light / heat curing adhesive comprises a binary or multi-component copolymer of ethylene and propylene, butene, pentene, hexene, octene, butadiene, 1,4-pentadiene, isoprene, ethylidene norbornene, dicyclopentadiene, and 1,4-hexadiene containing active groups as a base resin, ethylene glycol, a silane coupling agent, tert-butyl peroxyisopropyl carbonate, and N,N-dimethylcyclohexylamine, and the weight ratio is 70-98:0.05-10:0.01-2:0.01-2:0.01-2; the active group is an isocyanate group or an acyl chloride group.

6. The method for preparing a lightweight, high-density leather for labor protection shoes according to any one of claims 1 to 5, characterized in that: The steps include: Step 1: Apply polyurethane surface layer slurry on release paper to control the coating thickness to 0.05-0.2 mm, and obtain the polyurethane surface layer after drying; Step 2: Evenly apply adhesive on the polyurethane surface layer, controlling the coating thickness to be 0.1-0.2 mm, and drying it by 20-80% to obtain an adhesive surface layer; Step 3: attaching a laminated substrate consisting of an aluminum foil layer, a crushing layer, a semi-cured adhesive layer, and a bottom base fabric onto the adhesive surface layer, and peeling off the release paper after drying to obtain a lightweight, high-density leather for labor protection shoes.

7. The method for preparing a lightweight, high-density leather for labor protection shoes according to claim 6, characterized in that: The bottom base fabric is a fiber woven fabric or a non-woven fabric; the aluminum foil layer has a thickness of 0.05-0.1 mm and is laser-perforated; the crushing layer is formed by mixing and curing a glue solution comprising 16-24 parts by weight of vinyl acetate, 22-28 parts of butyl rubber, 7-12 parts of polyethylene, 0.01-2 parts of graphene, 0.01-1 parts of antioxidant, 0.5-1 parts of epoxy resin, and 0.5-1 parts of calcium carbonate; and the semi-cured glue layer is formed by curing a light / heat curing glue.

8. Use of the lightweight, high-density leather for labor protection shoes according to any one of claims 1 to 5 in labor protection shoe uppers.

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