A method for preparing acid-alkali resistant microfiber leather for safety protective shoes

Abstract

The present invention relates to the technical field of microfiber leather processing, and in particular to a method for preparing microfiber leather for acid- and alkali-resistant safety shoes. It includes the following steps: S1, using a coating machine No. 1 to evenly coat a first layer of acid- and alkali-resistant breathable resin on the release paper, and obtaining a surface layer after curing; S2, using a coating machine No. 2 to evenly coat a second layer of acid- and alkali-resistant breathable resin on the surface layer, and obtaining a middle layer after curing; S3, using a coating machine No. 3 to evenly coat a third layer of acid- and alkali-resistant breathable resin on the middle layer, and obtaining a bonding layer after curing; S4, laying the microfiber leather base cloth flat on the bonding layer of the release paper for pressing to obtain a microfiber leather rough product; S5, embossing, polishing, and cutting the microfiber leather rough product to obtain a microfiber leather product for acid- and alkali-resistant safety shoes. This method improves the stability of microfiber leather in acid- and alkali environments, thereby extending the stability of safety shoes in alkaline environments, thereby extending the service life of safety shoes and maintaining their good comfort and protective performance.

Description

Technical Field

[0001] The invention relates to the technical field of microfiber leather processing, and in particular to a method for preparing microfiber leather for acid and alkali resistant safety protective shoes. Background Art

[0002] Microfiber leather, full name of ultrafine fiber synthetic leather, is a new type of high-end leather material, also known as split leather, split transfer leather, split transfer leather, etc. Microfiber leather has a similar appearance and feel to natural leather, soft and plump, comfortable touch, excellent in appearance, feel, physical properties and environmental protection, and is widely used in many fields.

[0003] Safety shoes made of microfiber leather can provide good protection while remaining light and comfortable. The softness and good breathability of microfiber leather make safety shoes comfortable even when worn for a long time, which helps reduce foot fatigue and discomfort. However, when microfiber leather is exposed to a high pH environment for a long time, its chemical structure will be destroyed, causing the material to age faster, harden, discolor, lose elasticity, etc., thus affecting the comfort and protection of the shoes. In addition to accelerating aging, the acid-base environment will also reduce the physical properties of microfiber leather such as wear resistance and tear resistance, making the shoes more susceptible to damage and shortening their service life. Summary of the invention

[0004] In response to the defects mentioned in the background technology, the present invention provides a method for preparing acid- and alkali-resistant microfiber leather for safety protection shoes, aiming to improve the stability of the microfiber leather in acid and alkali environments, thereby extending the stability of the safety protection shoes in alkaline environments, thereby extending the service life of the safety protection shoes and maintaining their good comfort and protective performance.

[0005] In order to achieve the above-mentioned invention object, the technical scheme of the present invention is as follows: a method for preparing microfiber leather for acid and alkali resistant safety protective shoes, comprising the following steps:

[0006] S1. Use a coating machine No. 1 to evenly coat a layer of acid-base resistant moisture-permeable resin A with a viscosity of 2000-2500cps on the release paper, with a coating amount of 150-180g / m2, and then enter a drying room A for drying, slowly drying at a temperature of 70-100°C to fully cure the coating to obtain a surface layer;

[0007] S2. Use coating machine No. 2 to evenly coat a layer of acid-base resistant moisture-permeable resin B with a viscosity of 2500-3000cps on the surface layer, with a coating amount of 180-200g / m2, and then enter drying room B for drying, slowly drying at a temperature of 70-120°C to fully solidify the coating to obtain a middle layer;

[0008] S3, using a No. 3 coating machine to evenly coat a layer of acid-base resistant moisture-permeable resin C with a viscosity of 15000-20000cps on the middle layer, with a coating amount of 200-250g / m, and then entering a drying room C for drying, slowly drying at a temperature of 70-100°C for 1-2min to obtain a bonding layer;

[0009] S4, laying the microfiber leather base fabric on the adhesive layer of the release paper, pressing it at a pressure of 0.3-0.4 MPa for 5-10 minutes, and then entering the drying room D for drying, slowly drying at a temperature of 100-140° C., and finally separating the release paper from the microfiber leather base fabric to obtain a microfiber leather crude product;

[0010] S5. The rough microfiber leather product is embossed, polished and cut to obtain a microfiber leather product for acid and alkali resistant safety protective shoes.

[0011] Preferably, the acid-base resistant moisture-permeable resin comprises the following raw materials in parts by weight:

[0012] 35-45 parts of polyether polyol, 50-60 parts of solvent, 18-25 parts of ethanolamine, 30-35 parts of isocyanate, 8-10 parts of chain extender, and 2-5 parts of end-capping agent.

[0013] Preferably, the preparation method of the acid-base resistant moisture-permeable resin comprises:

[0014] A1. Add a predetermined amount of polyether polyol and solvent into the reactor, set the speed to 250 rpm, start heating, and stabilize the temperature at 30°C;

[0015] A2, after stirring and mixing for 30 minutes, add ethanolamine to react;

[0016] A3. After reacting for 30 minutes, the temperature was raised to 50°C, and then isocyanate was added to react;

[0017] A4. After continuing the reaction for 3 hours, isocyanate and chain extender are added again for reaction;

[0018] A5. After 1 hour of reaction, take a sample to test the viscosity of the resin. If the viscosity reaches 40,000-60,000 cps, add a blocking agent for blocking. If it does not meet the requirement, add additional isocyanate to continue the reaction until the viscosity meets the requirement.

[0019] Preferably, the solvent is toluene and dimethylformamide, and the weight ratio of dimethylformamide to toluene is 2:3.

[0020] Preferably, the chain extender is ethylene glycol.

[0021] Preferably, the capping agent is di-n-butylamine.

[0022] Preferably, the thickness of the acid-base resistant moisture-permeable resin A is 0.15 mm.

[0023] Preferably, the thickness of the acid-base resistant moisture-permeable resin B is 0.15 mm.

[0024] Preferably, the thickness of the acid-base resistant moisture-permeable resin C is 0.2 mm.

[0025] After adopting the above technical solution, the beneficial effects of the present invention are:

[0026] The method improves the stability of the microfiber leather in an acidic and alkaline environment, thereby extending the stability of the safety shoes in an alkaline environment, thereby extending the service life of the safety shoes and maintaining their good comfort and protective performance. DETAILED DESCRIPTION

[0027] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention.

[0028] Example 1

[0029] A method for preparing microfiber leather for acid and alkali resistant safety protective shoes comprises the steps of preparing a surface layer, preparing a middle layer, preparing a bonding layer, bonding a microfiber leather base cloth, and post-processing.

[0030] Step 1: Dilute the acid and alkali resistant moisture permeable resin

[0031] A predetermined amount of acid-base resistant moisture permeable resin is divided into three parts and diluted respectively to obtain acid-base resistant moisture permeable resin A with a viscosity of 2000-2500cps, acid-base resistant moisture permeable resin B with a viscosity of 2500-3000cps, and acid-base resistant moisture permeable resin C with a viscosity of 15000-20000cps.

[0032] The acid-base resistant moisture-permeable resin contains the following raw materials in parts by weight: 35 parts of polyether polyol, 50 parts of solvent, 18 parts of ethanolamine, 30 parts of isocyanate, 8 parts of chain extender, and 2 parts of end-capping agent.

[0033] Step 2: Prepare the surface layer

[0034] Prepare release paper as a carrier. Release paper can be reused. Before use, clean the surface impurities and slurry residues from the last use to ensure that the surface of the release paper is clean and tidy.

[0035] Use a coating machine No. 1 to evenly coat a layer of acid-base resistant moisture-permeable resin A with a thickness of 0.15 mm on the release paper, and the coating amount is 150-180 g / m. Send the coated release paper to drying room A and slowly dry it at a temperature of 70-100°C to ensure that the coating is fully cured to obtain a surface layer.

[0036] The initial temperature of drying room A is set to 70°C, and the drying time of the coated acid-base resistant moisture permeable resin A at this temperature is 0.5 to 1 minute. Then, the temperature of drying room A is raised to 80°C, and drying is performed at this temperature for 1 to 1.5 minutes. Finally, the temperature of drying room A is raised to 100°C, and drying is performed at this temperature for 1 to 1.5 minutes.

[0037] Step 3: Prepare the middle layer

[0038] Use the No. 2 coating machine to evenly coat a layer of acid-base resistant moisture-permeable resin B with a thickness of 0.15 mm on the surface layer, and the coating amount is 180-200 g / m. The coated surface layer is sent to the drying room B and slowly dried at a temperature of 70-120°C to fully solidify the coating to obtain the middle layer.

[0039] The initial temperature of drying room B is set to 70°C, and the drying time of the coated acid-base resistant moisture-permeable resin B at this temperature is 0.5 to 1 minute. Next, the temperature of drying room B is raised to 80°C, and drying is performed at this temperature for 0.5 to 1 minute. Then, the temperature of drying room B is raised to 100°C, and drying is performed at this temperature for 1 to 1.5 minutes. Finally, the temperature of drying room A is raised to 120°C, and drying is performed at this temperature for 1 to 1.5 minutes.

[0040] Step 4: Prepare the bonding layer

[0041] A layer of acid-base resistant moisture-permeable resin C with a thickness of 0.2 mm is evenly coated on the middle layer using a No. 3 coating machine, and the coating amount is 200-250 g / m. The coated middle layer is sent to a drying room C and slowly dried at a temperature of 70-100°C to obtain a bonding layer.

[0042] The initial temperature of the drying room C is set to 70°C, and the drying time of the coated acid-base resistant moisture permeable resin C at this temperature is 1 to 1.5 minutes. Then, the temperature of the drying room C is raised to 100°C, and drying is performed at this temperature for 1.5 to 2 minutes.

[0043] Step 5: Bonding the Microfiber Leather Base Fabric

[0044] Prepare the microfiber leather base cloth, immerse it in a pool containing a waterproofing agent (such as succinic acid) for 10 to 15 minutes to improve the hygroscopicity of the microfiber leather base cloth, then roll it to adjust the liquid rate to 42 to 48%, and finally dry the microfiber leather base cloth at a temperature of 145 to 150°C for 8 to 10 minutes.

[0045] Lay the dried microfiber leather base fabric on the adhesive layer of the release paper and press it for 5 to 10 minutes at a pressure of 0.3 to 0.4 MPa to ensure that the microfiber leather base fabric and the adhesive layer are tightly bonded. Send the pressed material to the drying room D and dry it at a temperature of 100 to 140°C for 5 to 10 minutes to make the bond more firm. Finally, separate the release paper from the microfiber leather base fabric to obtain the microfiber leather crude product. After the separated release paper is cleaned, it is reused as the carrier of the surface layer.

[0046] Step 6: Post-processing

[0047] The rough microfiber leather product is subjected to embossing, polishing, cutting and other treatments to obtain a microfiber leather product with beautiful appearance and acid and alkali resistance and safety protection performance, which is suitable for making safety protection shoes.

[0048] The preparation method of the acid-base resistant moisture-permeable resin comprises the following steps:

[0049] Step 1

[0050] A predetermined amount of polyether polyol and solvent were added to the reactor, the speed was set to 250 rpm, and heating was started to stabilize the temperature at 30°C. The solvent was toluene and dimethylformamide, and the weight ratio of dimethylformamide to toluene was 2:3.

[0051] Step 2

[0052] After stirring and mixing for 30 minutes, ethanolamine was added to react. Ethanolamine and polyether polyol began to react chemically to obtain polyurea.

[0053] Step 3

[0054] After 30 minutes of reaction, the temperature was raised to 50°C, and then a portion of isocyanate was added to react. Isocyanate reacts with polyurea to form a polyurethane structure.

[0055] Step 4

[0056] After the reaction was continued for 3 hours, isocyanate and chain extender were added again for reaction. The chain extender was ethylene glycol, which increased the length of the polymer chain and improved the performance of the resin.

[0057] Step 5

[0058] After 1 hour of reaction, take a sample to test the viscosity of the resin. If the viscosity reaches 40,000-60,000 cps, add a blocking agent for end-blocking treatment, and the blocking agent is di-n-butylamine to prevent further reaction of the resin. If the viscosity does not meet the requirements, add isocyanate to continue the reaction until the viscosity reaches the specified range.

[0059] Example 2

[0060] The difference from Example 1 is that the acid-base resistant moisture-permeable resin contains the following raw materials in parts by mass: 38 parts of polyether polyol, 52 parts of solvent, 18.5 parts of ethanolamine, 31 parts of isocyanate, 8.5 parts of chain extender, and 3 parts of end-capping agent.

[0061] Example 3

[0062] The difference from Example 1 is that the acid-base resistant moisture-permeable resin contains the following raw materials in parts by mass: 40 parts of polyether polyol, 55 parts of solvent, 20 parts of ethanolamine, 31.5 parts of isocyanate, 8.2 parts of chain extender, and 3.5 parts of end-capping agent.

[0063] Example 4

[0064] The difference from Example 1 is that the acid-base resistant moisture-permeable resin contains the following raw materials in parts by mass: 42 parts of polyether polyol, 56 parts of solvent, 22 parts of ethanolamine, 32.5 parts of isocyanate, 9 parts of chain extender, and 4 parts of end-capping agent.

[0065] Example 5

[0066] The difference from Example 1 is that the acid-base resistant moisture-permeable resin contains the following raw materials in parts by mass: 42.5 parts of polyether polyol, 58 parts of solvent, 24 parts of ethanolamine, 33 parts of isocyanate, 9.5 parts of chain extender, and 4.5 parts of end-capping agent.

[0067] Example 6

[0068] The difference from Example 1 is that the acid-base resistant moisture-permeable resin contains the following raw materials in parts by weight: 45 parts of polyether polyol, 60 parts of solvent, 25 parts of ethanolamine, 35 parts of isocyanate, 10 parts of chain extender, and 5 parts of end-capping agent, wherein the solvent is toluene and dimethylformamide, and the weight ratio of dimethylformamide to toluene is 2:3.

[0069] The microfiber leather products prepared in Examples 1-6 were tested for performance, and the specific test results are shown in the following table:

[0070]

[0071] Forest resistance for more than one week means being placed in an environment with a temperature of 70℃ and a humidity of 95% for one week.

[0072] According to the embodiments of the present invention as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to specific embodiments. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing acid- and alkali-resistant microfiber leather for safety protective shoes, characterized in that: The steps include: S1. Prepare an acid-base resistant moisture permeable resin, wherein the acid-base resistant moisture permeable resin comprises the following raw materials in parts by weight: 35-45 parts of polyether polyol, 50-60 parts of solvent, 18-25 parts of ethanolamine, 30-35 parts of isocyanate, 8-10 parts of chain extender, and 2-5 parts of end-capping agent; The preparation method of the acid-base resistant moisture-permeable resin comprises: A1. Add a predetermined amount of polyether polyol and solvent into the reactor, set the speed to 250 rpm, start heating, and stabilize the temperature at 30°C; A2, after stirring and mixing for 30 minutes, add ethanolamine to react; A3. After reacting for 30 minutes, the temperature was raised to 50°C, and then isocyanate was added to react; A4. After continuing the reaction for 3 hours, isocyanate and chain extender are added again for reaction; A5. After 1 hour of reaction, take a sample to test the viscosity of the resin. If the viscosity reaches 40,000-60,000 cps, add a blocking agent for blocking. If it does not meet the requirement, add isocyanate to continue the reaction until the viscosity meets the requirement. S2, diluting the prepared acid-base resistant moisture permeable resin into acid-base resistant moisture permeable resin A, acid-base resistant moisture permeable resin B and acid-base resistant moisture permeable resin C with different viscosities; S3, using coating machine No. 1 to evenly coat a layer of acid-base resistant moisture-permeable resin A with a viscosity of 2000-2500cps on the release paper, with a coating amount of 150-180g / m, and then entering drying room A for drying, slowly drying at a temperature of 70-100°C to fully cure the coating to obtain a surface layer; S4. Use coating machine No. 2 to evenly coat a layer of acid-base resistant moisture-permeable resin B with a viscosity of 2500-3000cps on the surface layer, with a coating amount of 180-200g / m2, and then enter drying room B for drying, slowly drying at a temperature of 70-120°C to fully cure the coating to obtain a middle layer; S5. Use a No. 3 coating machine to evenly coat a layer of acid-base resistant moisture-permeable resin C with a viscosity of 15,000 to 20,000 cps on the middle layer, with a coating amount of 200 to 250 g / m, and then enter a drying room C for drying, slowly drying at a temperature of 70 to 100° C. for 1 to 2 minutes to obtain a bonding layer; S6, laying the microfiber leather base fabric on the adhesive layer of the release paper, pressing at a pressure of 0.3-0.4 MPa for 5-10 minutes, and then entering the drying room D for drying, slowly drying at a temperature of 100-140° C., and finally separating the release paper from the microfiber leather base fabric to obtain a microfiber leather crude product; S7. The rough microfiber leather product is embossed, polished and cut to obtain a microfiber leather product for acid and alkali resistant safety protective shoes.

2. The method for preparing the acid- and alkali-resistant microfiber leather for safety shoes according to claim 1, characterized in that: The solvent is toluene and dimethylformamide, and the weight ratio of dimethylformamide to toluene is 2:

3.

3. The method for preparing the acid- and alkali-resistant microfiber leather for safety shoes according to claim 1, characterized in that: The chain extender is ethylene glycol.

4. The method for preparing the acid- and alkali-resistant microfiber leather for safety shoes according to claim 1, characterized in that: The end-capping agent is di-n-butylamine.

5. The method for preparing the acid- and alkali-resistant microfiber leather for safety shoes according to claim 1, characterized in that: The thickness of the acid-base resistant moisture-permeable resin A is 0.15 mm.

6. The method for preparing the acid- and alkali-resistant microfiber leather for safety shoes according to claim 1, characterized in that: The thickness of the acid-base resistant moisture-permeable resin B is 0.15 mm.

7. The method for preparing the acid- and alkali-resistant microfiber leather for safety shoes according to claim 1, characterized in that: The thickness of the acid-base resistant moisture-permeable resin C is 0.2 mm.

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