Thermoplastic polyurethane electronic packaging leather and preparation method thereof

Abstract

The invention discloses thermoplastic polyurethane electronic packaging leather and a preparation method thereof, and relates to the technical field of electronic packaging leather, the thermoplastic polyurethane electronic packaging leather comprises a base cloth layer, a bonding layer, a wear-resistant layer and a waterproof and oil-resistant surface layer which are sequentially attached and compounded; the waterproof and oil-resistant surface layer is prepared from a silicofluoride modified chitosan composite monomer, polysiloxane, waterborne polyurethane resin, fluorine-substituted organic amine and a cross-linking agent; the preparation method of the siflurane modified chitosan composite monomer comprises the following steps: (1) putting chitosan into an alcoholic solution, carrying out ultrasonic oscillation cleaning, and drying to obtain clean chitosan; (2) carrying out grafting treatment on the activated polylactic acid-glycolic acid copolymer, polytetrahydrofuran ether glycol or polyethylene glycol and clean chitosan to obtain modified chitosan; (3) mixing the modified chitosan with heptadecafluorodecyl trimethoxysilane, and carrying out ultrasonic oscillation treatment, so as to obtain a pre-composite material; and (4) baking, taking out and cooling. The oil-proof antifouling fabric has the effective oil-proof antifouling effect.

Description

Technical Field

[0001] The present application relates to the technical field of electronic packaging leather, and in particular to a thermoplastic polyurethane electronic packaging leather and a preparation method thereof. Background Art

[0002] The high-precision development of electronic products has brought huge challenges to the requirements of electronic packaging materials. Electronic packaging materials with full coverage, high peeling, water resistance and acid and alkali chemical corrosion resistance have become the key functional requirements of electronic products in terms of packaging materials.

[0003] Announcement No. CN105133372B discloses a method for preparing TPU polyurethane synthetic leather for electronic packaging and stationery documents, and the method for preparing TPU polyurethane synthetic leather for electronic packaging and stationery documents comprises the following steps: (1) using a TPU composite film obtained by compounding a high melting point TPU film and a low melting point TPU film as a substrate; the high melting point TPU film has a thickness of 0.10-0.20 mm and a melting point of 110-140° C.; the low melting point TPU film has a thickness of 0.05-0.10 mm and a melting point of 70-90° C.; the TPU composite film is commercially available, such as H8025 or PHT0520; (2) 2) coating the surface layer slurry on the release paper, the coating thickness of the surface layer slurry is 0.10-0.15mm, and drying and curing at 100-130°C forms a surface layer, and then coating the middle layer slurry on the surface layer, the coating thickness of the middle layer slurry is 0.15-0.20mm, and drying and curing at 100-130°C forms an middle layer; (3) using low melting point polyether polyurethane resin U-50 as a bonding layer, coating the bonding layer on the middle layer prepared in step (2), the coating thickness of the bonding layer is 0.15-0.20mm, drying at 90-130°C and laminating with the TPU composite film, aging at 90-110°C, cooling and peeling off the release paper to obtain a finished product.

[0004] However, the preparation method of polyurethane synthetic leather for TPU electronic packaging and stationery documents still has problems such as shedding and separation during use and poor surface oil resistance when using a multi-layer composite structure, which affects the cleanliness of electronic products during use and needs to be improved. Summary of the invention

[0005] In view of this, the first purpose of the present application is to provide a thermoplastic polyurethane electronic packaging leather to achieve the purpose of effective oil and dirt resistance. The specific scheme is as follows:

[0006] A thermoplastic polyurethane electronic packaging leather comprises a base fabric layer, an adhesive layer, a wear-resistant layer and a waterproof and oil-proof surface layer which are attached in sequence; the waterproof and oil-proof surface layer is coated on the wear-resistant layer by a coating machine and then dried to obtain the waterproof and oil-proof surface layer; the waterproof and oil-proof surface layer comprises 0.6-1.8 parts by weight of a silfluoroethane@modified chitosan composite monomer, 3-7 parts by weight of a polysiloxane, 42-60 parts by weight of an aqueous polyurethane resin, 12-15 parts by weight of a fluorine-substituted organic amine and 6-12 parts by weight of a cross-linking agent of 10-12%; the silfluoroethane@modified chitosan The preparation of the composite monomer comprises the steps of ① placing chitosan in an alcohol solution for ultrasonic cleaning, and drying to obtain clean chitosan; ② taking activated polylactic acid-hydroxyacetic acid copolymer, polytetramethylene glycol or polyethylene glycol and grafting the clean chitosan to obtain modified chitosan; ③ mixing the modified chitosan with heptadecafluorodecyltrimethoxysilane, and subjecting the mixture to ultrasonic cleaning to obtain a pre-composite material; and ④ placing the pre-composite material in an oven at 200-300°C for baking for 30-60 minutes, and cooling the pre-composite material to room temperature after taking it out.

[0007] Preferably: the activation treatment of the polylactic acid-co-glycolic acid copolymer, polytetrahydrofuran ether glycol or polyethylene glycol is carried out by dissolving in an organic solvent, mixing and stirring with carbonyl diimidazole at a temperature of 35-40°C, and then cooling and filtering to obtain the mixture; the organic solvent is dichloromethane or tetrahydrofuran.

[0008] Preferably: the grafting treatment includes preparing chitosan gel from clean chitosan, mixing the chitosan gel with epichlorohydrin at a molar ratio of 1:0.5, adding excess ethylene dichloride to react to obtain active chitosan gel, and finally mixing the active chitosan gel with activated polylactic acid-co-glycolic acid copolymer, polytetramethylene glycol or polyethylene glycol at a molar ratio of 1:0.6-0.8 for 3 hours, and controlling the temperature to 20-30°C.

[0009] Preferably, the chitosan gel is obtained by dissolving clean chitosan with 1% acetic acid to obtain dissolved chitosan, and then spraying the dissolved chitosan into a 1% sodium hydroxide solvent, wherein the solvent is a methanol aqueous solution containing methanol.

[0010] Preferably: the silicone resin is purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd.; the polyethylene glycol is purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd.; the chitosan is purchased from high-density chitosan from Shanghai MacLean Biochemical Technology Co., Ltd.

[0011] Preferably: the base fabric layer is TR fabric or is woven by blending 65-75% polyester fiber and 25-35% spandex fiber; the adhesive layer is thermoplastic water-based polyurethane.

[0012] Preferably, the wear-resistant layer is composed of waterborne polyurethane and glass fiber, and the glass fiber is 3 mm or 6 mm chopped glass fiber.

[0013] The second object of the present application is to provide a method for preparing a thermoplastic polyurethane electronic packaging leather, which is used to prepare the thermoplastic polyurethane electronic packaging leather as described above, comprising the following steps:

[0014] Step 1, bonding and coating: taking a base fabric, coating the base fabric with thermoplastic waterborne polyurethane, and drying the base fabric to form a bonding germ layer;

[0015] Step 2, wear-resistant lamination: take release paper and coat the wear-resistant layer slurry, dry it to obtain the wear-resistant layer, and then attach the wear-resistant layer to the bonding germ layer, and after ripening, obtain the inner base layer;

[0016] Step 3, surface layer processing: take the inner base layer and place it in a coating machine, apply the surface layer slurry on the surface of the wear-resistant layer, and obtain the electronic packaging leather after drying.

[0017] Preferably, the viscosity of the thermoplastic waterborne polyurethane at room temperature is 6000-9000 cps, the coating thickness of the thermoplastic waterborne polyurethane is 0.1-0.2 mm, and the drying temperature is 60-80°C.

[0018] Preferably, the aging is a two-step aging, and the temperature of the first aging is controlled to be 100-120° C. and the time is 15 minutes; the temperature of the second aging is controlled to be 50-60° C. and the time is 12-16 hours.

[0019] It can be seen from the above scheme that the present application provides a thermoplastic polyurethane electronic packaging leather and a preparation method thereof. The thermoplastic polyurethane electronic packaging leather achieves high-strength bonding between the base fabric layer and the wear-resistant layer by adopting an adhesive layer, and improves the wear resistance of the overall structure by the wear-resistant layer, while effectively combining the waterproof and oil-proof surface layer with the wear-resistant layer, thereby avoiding the shedding phenomenon and improving the waterproof and oil-proof ability of the thermoplastic polyurethane electronic packaging leather; at the same time, a combination of silfluoroethane @ modified chitosan composite monomer and polysiloxane is used to cooperate with fluorine-substituted organic amines to achieve effective waterproof and oil-proof effects. Among them, after the activation treatment, polylactic acid glycolic acid copolymer, polytetramethylene glycol or polyethylene glycol will be dehydrated and condensed with carbonyl diimidazole, and then further modified with activated amino chitosan to form a grafted combination of chitosan amino and polylactic acid glycolic acid copolymer, polytetramethylene glycol or polyethylene glycol and carbonyl diimidazole dehydration condensation product, while protecting the amino group, effectively adsorbing and combining with polysiloxane and fluorine-substituted organic amine, so as to resist pores and waterproof without adsorbing oily substances. The preparation method of the thermoplastic polyurethane electronic packaging leather has the effects of convenient operation, economical and efficient, and the thermoplastic polyurethane electronic packaging leather prepared by the preparation method of the thermoplastic polyurethane electronic packaging leather has the effect of effective oil and dirt resistance. 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0021] Figure 1 This is a schematic diagram of the structure of the thermoplastic polyurethane electronic packaging leather disclosed in this application.

[0022] Explanation of the accompanying drawings: 1. base fabric layer; 2. adhesive layer; 3. wear-resistant layer; 4. waterproof and oil-proof surface layer. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] It should be mentioned that the methanol-water solution is a solution of methanol and water in a ratio of 1:1, which can be prepared by oneself or purchased from the market, and other proportions of methanol and water mixed solutions can be used, which will not be elaborated here. Fluorine-substituted organic amines are fluorine-substituted aniline, decylamine, tert-butylamine, butanamide, and hexamethylenetetramine. Of course, other organic amines within C16 can also be used, which will not be elaborated here. Silicone resin is purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd. Polyethylene glycol is purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd. Chitosan is a high-density chitosan purchased from Shanghai McLean Biochemical Technology Co., Ltd., with a relative molecular mass of 30,000.

[0025] The thermoplastic polyurethane electronic packaging leather and the preparation method thereof of the present application will be described in detail below.

[0026] like Figure 1 As shown, a thermoplastic polyurethane electronic packaging leather comprises a base fabric layer, an adhesive layer, a wear-resistant layer and a waterproof and oil-proof surface layer which are attached in sequence; the waterproof and oil-proof surface layer is coated on the wear-resistant layer by a coating machine and then dried to obtain the waterproof and oil-proof surface layer; the waterproof and oil-proof surface layer comprises 0.6-1.8 parts by weight of a silfluorocarbon@modified chitosan composite monomer, 3-7 parts by weight of a polysiloxane, 42-60 parts by weight of an aqueous polyurethane resin, 12-15 parts by weight of a fluorine-substituted organic amine and 6-12 parts by weight of a cross-linking agent of 10-12%; the silfluorocarbon@modified chitosan composite monomer is coated on the wear-resistant layer by a coating machine and then dried to obtain the waterproof and oil-proof surface layer; the waterproof and oil-proof surface layer comprises 0.6-1.8 parts by weight of a silfluorocarbon@modified chitosan composite monomer, 3-7 parts by weight of a polysiloxane, 42-60 parts by weight of a water-based ... The preparation of polysaccharide composite monomers includes the steps of ① placing chitosan in an alcohol solution for ultrasonic cleaning, and obtaining clean chitosan through drying; ② taking activated polylactic acid-hydroxyacetic acid copolymer, polytetramethylene glycol or polyethylene glycol and grafting the clean chitosan to obtain modified chitosan; ③ mixing the modified chitosan with heptadecafluorodecyltrimethoxysilane, and obtaining a pre-composite material after ultrasonic treatment; and ④ placing the pre-composite material in an oven at 200-300°C for baking for 30-60 minutes, taking it out and cooling it to room temperature.

[0027] Among them, the activation treatment of polylactic acid-co-glycolic acid copolymer, polytetramethylene glycol or polyethylene glycol is dissolved by an organic solvent, mixed and stirred with carbonyl diimidazole at a temperature of 35-40°C and then cooled and filtered to obtain; the organic solvent is dichloromethane or tetrahydrofuran. The grafting treatment includes preparing chitosan gel from clean chitosan, mixing chitosan gel with epichlorohydrin at a molar ratio of 1:0.5, adding excess dichloroethane to react to obtain active chitosan gel, and finally mixing the active chitosan gel with the activated polylactic acid-co-glycolic acid copolymer, polytetramethylene glycol or polyethylene glycol at a molar ratio of 1:0.6-0.8 for 3 hours, and controlling the temperature to 20-30°C.

[0028] It should be mentioned that the chitosan gel is obtained by dissolving clean chitosan with 1% acetic acid to obtain dissolved chitosan, and then spraying the dissolved chitosan into a 1% sodium hydroxide solvent, the solvent being a methanol aqueous solution containing methanol. At the same time, the base fabric layer is TR fabric or a blended weave of 65-75% polyester fiber and 25-35% spandex fiber. The adhesive layer is thermoplastic waterborne polyurethane.

[0029] In order to effectively improve the wear resistance of the wear-resistant layer and the bonding strength with the base fabric layer and the waterproof and oil-proof surface layer, the wear-resistant layer is composed of water-based polyurethane and glass fiber, and the glass fiber is 3mm or 6mm short-cut glass fiber. The short-cut glass fiber plays a role in improving the strength of the wear-resistant layer and thus the wear resistance, and then realizes effective bonding with the adhesive layer and the waterproof and oil-proof surface layer through porous adsorption capacity.

[0030] A method for preparing a thermoplastic polyurethane electronic packaging leather, which is used to prepare the thermoplastic polyurethane electronic packaging leather as described above, comprises the following steps:

[0031] Step 1, bonding and coating: taking a base fabric, coating the base fabric with thermoplastic waterborne polyurethane, and drying the base fabric to form a bonding germ layer;

[0032] Step 2, wear-resistant lamination: take release paper and coat the wear-resistant layer slurry, dry it to obtain the wear-resistant layer, and then attach the wear-resistant layer to the bonding germ layer, and after ripening, obtain the inner base layer;

[0033] Step 3, surface layer processing: take the inner base layer and place it in a coating machine, apply the surface layer slurry on the surface of the wear-resistant layer, and obtain the electronic packaging leather after drying.

[0034] The viscosity of the thermoplastic waterborne polyurethane at room temperature is 6000-9000 cps, and it is KN5075 purchased from Guangdong Kelisen Resin Co., Ltd. In the present application, the coating thickness of the thermoplastic waterborne polyurethane is 0.1-0.2 mm, and the drying temperature is controlled to be 60-80°C.

[0035] At the same time, the ripening is a secondary step ripening, and the temperature of the first ripening is controlled to be 100-120°C, and the time is 15 minutes; the temperature of the second ripening is 50-60°C, and the time is 12-16 hours.

[0036] Embodiment 1

[0037] like Figure 1As shown, a thermoplastic polyurethane electronic packaging leather comprises a base fabric layer, an adhesive layer, a wear-resistant layer and a waterproof and oil-proof surface layer which are attached in sequence; the waterproof and oil-proof surface layer is coated on the wear-resistant layer by a coating machine and then dried to obtain the waterproof and oil-proof surface layer; the waterproof and oil-proof surface layer comprises 0.6 parts by weight of a silfluorocarbon@modified chitosan composite monomer, 3 parts of polysiloxane, 42 parts of an aqueous polyurethane resin, 12 parts of a fluorine-substituted organic amine and 6 parts of a cross-linking agent of 10% by mass; the silfluorocarbon@modified chitosan composite monomer comprises 0.6 parts by weight of a silfluorocarbon@modified chitosan composite monomer, 3 parts of a ... The preparation of chitosan composite monomer includes the steps of ① placing chitosan in an alcohol solution for ultrasonic cleaning, and obtaining clean chitosan through drying; ② taking activated polylactic acid-hydroxyacetic acid copolymer and grafting it with clean chitosan to obtain modified chitosan; ③ mixing the modified chitosan with heptadecafluorodecyltrimethoxysilane, and obtaining a pre-composite material after ultrasonic treatment; and ④ placing the pre-composite material in an oven at 200°C for baking for 60 minutes, taking it out and cooling it to room temperature.

[0038] Among them, the activation treatment of polylactic acid-glycolic acid copolymer is dissolved by an organic solvent, mixed and stirred with carbonyl diimidazole at a temperature of 35°C and then cooled and filtered to obtain; the organic solvent is dichloromethane. The grafting treatment includes preparing chitosan gel from clean chitosan, mixing chitosan gel with epichlorohydrin at a molar ratio of 1:0.5, adding excess dichloroethane to react to obtain active chitosan gel, and finally mixing the active chitosan gel with the activated polylactic acid-glycolic acid copolymer at a molar ratio of 1:0.6 for 3 hours, and controlling the temperature at 20°C.

[0039] It should be mentioned that the chitosan gel is obtained by dissolving clean chitosan with 1% acetic acid to obtain dissolved chitosan, and then spraying the dissolved chitosan into a 1% sodium hydroxide solvent, the solvent being a methanol aqueous solution containing methanol. Meanwhile, the base fabric layer is TR fabric, and the adhesive layer is thermoplastic waterborne polyurethane.

[0040] In order to effectively improve the wear resistance of the wear-resistant layer and the bonding strength with the base fabric layer and the waterproof and oil-proof surface layer, the wear-resistant layer is composed of water-based polyurethane and glass fiber, and the glass fiber is 3mm short-cut glass fiber. The short-cut glass fiber plays a role in improving the strength of the wear-resistant layer and thus improving the wear resistance, and then through the porous adsorption capacity, it can achieve effective bonding with the adhesive layer and the waterproof and oil-proof surface layer.

[0041] A method for preparing a thermoplastic polyurethane electronic packaging leather, which is used to prepare the thermoplastic polyurethane electronic packaging leather as described above, comprises the following steps:

[0042] Step 1, bonding coating: take a base fabric, apply thermoplastic waterborne polyurethane on the base fabric with a coating thickness of 0.1 mm, and then dry it at a temperature of 60° C. to form a bonding germ layer;

[0043] Step 2, wear-resistant lamination: take release paper and coat the wear-resistant layer slurry, dry it at 70°C to obtain the wear-resistant layer, and then attach the wear-resistant layer to the bonding germ layer, and after ripening, obtain the inner base layer;

[0044] Step 3, surface layer processing: take the inner base layer and place it in a coating machine, apply the surface layer slurry on the surface of the wear-resistant layer, and obtain the electronic packaging leather after drying at a temperature of 80°C.

[0045] The aging is a two-step aging process, and the temperature of the first aging is controlled at 100°C and the time is 15 minutes; the temperature of the second aging is controlled at 60°C and the time is 12 hours.

[0046] Embodiment 2

[0047] like Figure 1 As shown, a thermoplastic polyurethane electronic packaging leather comprises a base fabric layer, an adhesive layer, a wear-resistant layer and a waterproof and oil-proof surface layer which are attached in sequence; the waterproof and oil-proof surface layer is coated on the wear-resistant layer by a coating machine and then dried to obtain the waterproof and oil-proof surface layer; the waterproof and oil-proof surface layer comprises 1.2 parts by weight of a silfluorocarbon@modified chitosan composite monomer, 5 parts of a polysiloxane, 50 parts of an aqueous polyurethane resin, 14 parts of a fluorine-substituted organic amine and 10 parts of a cross-linking agent with a mass percentage of 11%; the silfluorocarbon@ The preparation of the modified chitosan composite monomer includes the steps of ① placing chitosan in an alcohol solution for ultrasonic cleaning, and obtaining clean chitosan through drying; ② taking activated polytetrahydrofuran ether diol and clean chitosan for grafting to obtain modified chitosan; ③ mixing the modified chitosan with heptadecafluorodecyltrimethoxysilane, and obtaining a pre-composite material after ultrasonic treatment; and ④ placing the pre-composite material in an oven at 250°C for baking for 45 minutes, taking it out and cooling it to room temperature.

[0048] Among them, the activation treatment of polytetrahydrofuran ether diol is dissolved by an organic solvent, mixed and stirred with carbonyl diimidazole at a temperature of 38°C, and then cooled and filtered to obtain; the organic solvent is dichloromethane. The grafting treatment includes preparing chitosan gel from clean chitosan, mixing chitosan gel with epichlorohydrin at a molar ratio of 1:0.5, adding excess dichloroethane to react to obtain active chitosan gel, and finally mixing the active chitosan gel with the activated polytetrahydrofuran ether diol at a molar ratio of 1:0.7 for 3 hours, and controlling the temperature at 25°C.

[0049] It should be mentioned that the chitosan gel is obtained by dissolving clean chitosan with 1% acetic acid to obtain dissolved chitosan, and then spraying the dissolved chitosan into a 1% sodium hydroxide solvent, the solvent being a methanol aqueous solution containing methanol. At the same time, the base fabric layer is woven from a blend of 70% polyester fiber and 30% spandex fiber. The adhesive layer is thermoplastic waterborne polyurethane.

[0050] In order to effectively improve the wear resistance of the wear-resistant layer and the bonding strength with the base fabric layer and the waterproof and oil-proof surface layer, the wear-resistant layer is composed of water-based polyurethane and glass fiber, and the glass fiber is 6mm short-cut glass fiber. The short-cut glass fiber plays a role in improving the strength of the wear-resistant layer and thus improving the wear resistance, and then through the porous adsorption capacity, it can achieve effective bonding with the adhesive layer and the waterproof and oil-proof surface layer.

[0051] A method for preparing a thermoplastic polyurethane electronic packaging leather, which is used to prepare the thermoplastic polyurethane electronic packaging leather as described above, comprises the following steps:

[0052] Step 1, bonding coating: take a base fabric, apply thermoplastic waterborne polyurethane on the base fabric with a coating thickness of 0.15 mm, and then dry it at a temperature of 65° C. to form a bonding germ layer;

[0053] Step 2, wear-resistant lamination: take release paper and coat the wear-resistant layer slurry, dry it at 70°C to obtain the wear-resistant layer, and then attach the wear-resistant layer to the bonding germ layer, and after ripening, obtain the inner base layer;

[0054] Step 3, surface layer processing: take the inner base layer and place it in a coating machine, apply the surface layer slurry on the surface of the wear-resistant layer, and obtain the electronic packaging leather after drying at a temperature of 80°C.

[0055] The aging is a two-step aging process, and the temperature of the first aging is controlled at 110°C and the time is 15 minutes; the temperature of the second aging is controlled at 55°C and the time is 14 hours.

[0056] Embodiment 3

[0057] like Figure 1As shown, a thermoplastic polyurethane electronic packaging leather comprises a base fabric layer, an adhesive layer, a wear-resistant layer and a waterproof and oil-proof surface layer which are attached in sequence; the waterproof and oil-proof surface layer is coated on the wear-resistant layer by a coating machine and then dried to obtain the waterproof and oil-proof surface layer; the waterproof and oil-proof surface layer comprises 1.8 parts by weight of a silfluoroethane@modified chitosan composite monomer, 7 parts of polysiloxane, 60 parts of an aqueous polyurethane resin, 15 parts of a fluorine-substituted organic amine and 12 parts of a cross-linking agent with a mass percentage of 12%; the silfluoroethane@modified chitosan composite monomer comprises 1.8 parts by weight of a silfluoroethane@modified chitosan composite monomer, 7 parts of a ... The preparation of alkyl modified chitosan composite monomer includes the steps of ① placing chitosan in an alcohol solution for ultrasonic cleaning, and obtaining clean chitosan through drying; ② grafting the activated polyethylene glycol with the clean chitosan to obtain modified chitosan; ③ mixing the modified chitosan with heptadecafluorodecyltrimethoxysilane, and obtaining a pre-composite material after ultrasonic treatment; and ④ placing the pre-composite material in an oven at 300°C for 30 minutes, taking it out and cooling it to room temperature.

[0058] Among them, the activation treatment of polyethylene glycol is dissolved by an organic solvent, mixed and stirred with carbonyl diimidazole at a temperature of 40°C and then cooled and filtered to obtain; the organic solvent is tetrahydrofuran. The grafting treatment includes preparing chitosan gel from clean chitosan, mixing chitosan gel with epichlorohydrin at a molar ratio of 1:0.5, adding excess dichloroethane to react to obtain active chitosan gel, and finally mixing the active chitosan gel with the activated polyethylene glycol at a molar ratio of 1:0.8 for 3 hours, and controlling the temperature at 30°C.

[0059] It should be mentioned that the chitosan gel is obtained by dissolving clean chitosan with 1% acetic acid to obtain dissolved chitosan, and then spraying the dissolved chitosan into a 1% sodium hydroxide solvent, the solvent being a methanol aqueous solution containing methanol. At the same time, the base fabric layer is woven from a blend of 75% polyester fiber and 25% spandex fiber. The adhesive layer is thermoplastic waterborne polyurethane.

[0060] In order to effectively improve the wear resistance of the wear-resistant layer and the bonding strength with the base fabric layer and the waterproof and oil-proof surface layer, the wear-resistant layer is composed of water-based polyurethane and glass fiber, and the glass fiber is 3mm short-cut glass fiber. The short-cut glass fiber plays a role in improving the strength of the wear-resistant layer and thus improving the wear resistance, and then through the porous adsorption capacity, it can achieve effective bonding with the adhesive layer and the waterproof and oil-proof surface layer.

[0061] A method for preparing a thermoplastic polyurethane electronic packaging leather, which is used to prepare the thermoplastic polyurethane electronic packaging leather as described above, comprises the following steps:

[0062] Step 1, bonding coating: take a base fabric, apply thermoplastic waterborne polyurethane on the base fabric with a coating thickness of 0.2 mm, and then dry it at a temperature of 80° C. to form a bonding germ layer;

[0063] Step 2, wear-resistant lamination: take release paper and coat the wear-resistant layer slurry, dry it at 60°C to obtain the wear-resistant layer, and then attach the wear-resistant layer to the bonding germ layer, and after ripening, obtain the inner base layer;

[0064] Step 3, surface layer processing: take the inner base layer and place it in a coating machine, apply the surface layer slurry on the surface of the wear-resistant layer, and obtain the electronic packaging leather after drying at a temperature of 60°C.

[0065] The aging is a two-step aging process, and the temperature of the first aging is controlled at 120°C and the time is 15 minutes; the temperature of the second aging is controlled at 50°C and the time is 16 hours.

[0066] Comparative Example 1

[0067] The difference between Comparative Example 1 and Example 3 is that the polyethylene glycol in Comparative Example 1 has not been activated.

[0068] Comparative Example 2

[0069] The difference between Comparative Example 2 and Example 3 is that in Comparative Example 2, modified chitosan is used to replace the silfluoroethane@modified chitosan composite monomer.

[0070] Comparative Example 3

[0071] The difference between Comparative Example 3 and Example 3 is that no fluorine-substituted organic amine is added in Comparative Example 3.

[0072] test:

[0073] 1. Water repellency test: in accordance with GB / T 4745-2012 "Testing and evaluating the waterproof performance of textiles - Water-impregnation method";

[0074] 2. Oil repellency test: in accordance with GB / T 19977-2014 "Textile Oil Repellency and Hydrocarbon Resistance Test";

[0075] 3. Wear resistance test: After flattening and fixing, the roller friction test is used to test the number of times the material will break.

[0076] The weight of the control roller is 200g;

[0077] 4. Peel strength test: Use a stretching machine to stretch and peel the sample to 20mm, control the size to 100mm*25mm, and the bonding length to 70mm.

[0078] The following are the performance test results for Examples 1 to 3 and Comparative Examples 1 to 3, and the specific results are shown in Table 1 below.

[0079] Table 1 Performance test results

[0080] Water repellency Oil repellency Wear resistance Peel strength (N / 3cm) Embodiment 1 Level 5 Level 5 280 times 74 Embodiment 2 Level 5 Level 5 285 times 77 Embodiment 3 Level 5 Level 5 295 times 81 Comparative Example 1 Level 2 Level 3 285 times 64 Comparative Example 2 Level 2 Level 2 280 times 75 Comparative Example 3 Level 4 Level 4 290 times 80

[0081] As can be seen from Table 1 above, the thermoplastic polyurethane electronic packaging leather and the preparation method thereof of the present application achieve the synergistic improvement of structural strength and wear resistance while effectively combining the water and oil repellency of fluorine-substituted organic amines through innovative design and combination of the components of the raw materials, so that when the thermoplastic polyurethane electronic packaging leather obtained by the preparation method is used, it can achieve long-lasting durability and effective water and oil resistance, and achieve efficient and stable protection for electronic products.

[0082] In summary, the present application provides a thermoplastic polyurethane electronic packaging leather and a preparation method thereof. The thermoplastic polyurethane electronic packaging leather achieves high-strength bonding between a base fabric layer and a wear-resistant layer by using an adhesive layer, and improves the wear resistance of the overall structure by using the wear-resistant layer, while effectively combining the waterproof and oil-proof surface layer with the wear-resistant layer, thereby avoiding the shedding phenomenon and improving the waterproof and oil-proof ability of the thermoplastic polyurethane electronic packaging leather; at the same time, a combination of silfluoroethane@modified chitosan composite monomer and polysiloxane is used to cooperate with fluorine-substituted organic amines to achieve effective waterproof and oil-proof effects. Among them, after the activation treatment, polylactic acid glycolic acid copolymer, polytetramethylene glycol or polyethylene glycol will be dehydrated and condensed with carbonyl diimidazole, and then further modified with activated amino chitosan to form a grafted combination of chitosan amino and polylactic acid glycolic acid copolymer, polytetramethylene glycol or polyethylene glycol and carbonyl diimidazole dehydration condensation product, while protecting the amino group, effectively adsorbing and combining with polysiloxane and fluorine-substituted organic amine, so as to resist pores and waterproof without adsorbing oily substances. The preparation method of the thermoplastic polyurethane electronic packaging leather has the effects of convenient operation, economical and efficient, and the thermoplastic polyurethane electronic packaging leather prepared by the preparation method of the thermoplastic polyurethane electronic packaging leather has the effect of effective oil and dirt resistance.

[0083] The "first", "second", "third", "fourth", etc. (if any) referred to in this application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be 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" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, or devices.

[0084] It should be noted that the descriptions involving "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0085] Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present 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 a limitation on the present application.

Claims

1. A thermoplastic polyurethane electronic packaging leather, characterized in that: The invention comprises a base fabric layer, an adhesive layer, a wear-resistant layer and a waterproof and oil-proof surface layer which are attached in sequence; the waterproof and oil-proof surface layer is coated on the wear-resistant layer by a coating machine and then dried; the waterproof and oil-proof surface layer comprises 0.6-1.8 parts by weight of a silfluoroethane@modified chitosan composite monomer, 3-7 parts by weight of a polysiloxane, 42-60 parts by weight of an aqueous polyurethane resin, 12-15 parts by weight of a fluorine-substituted organic amine and 6-12 parts by weight of a cross-linking agent of 10-12%; the preparation method of the silfluoroethane@modified chitosan composite monomer The method comprises the steps of: ① placing chitosan in an alcohol solution for ultrasonic cleaning, and drying to obtain clean chitosan; ② taking activated polylactic acid-glycolic acid copolymer, polytetramethylene glycol or polyethylene glycol and grafting the clean chitosan to obtain modified chitosan; ③ mixing the modified chitosan with heptadecafluorodecyltrimethoxysilane, and subjecting the mixture to ultrasonic cleaning to obtain a pre-composite material; and ④ placing the pre-composite material in an oven at 200-300°C for baking for 30-60 minutes, and cooling the pre-composite material to room temperature after taking it out.

2. The thermoplastic polyurethane electronic packaging leather according to claim 1, characterized in that: The activation treatment of the polylactic acid-co-glycolic acid copolymer, polytetrahydrofuran ether glycol or polyethylene glycol is carried out by dissolving in an organic solvent, mixing and stirring with carbonyl diimidazole at a temperature of 35-40° C., and then cooling and filtering to obtain the obtained product; the organic solvent is dichloromethane or tetrahydrofuran.

3. The thermoplastic polyurethane electronic packaging leather according to claim 1, characterized in that: The grafting treatment comprises preparing chitosan gel from clean chitosan, mixing the chitosan gel with epichlorohydrin at a molar ratio of 1:0.5, adding excess ethylene dichloride to react to obtain active chitosan gel, and finally mixing the active chitosan gel with activated polylactic acid-co-glycolic acid copolymer, polytetramethylene glycol or polyethylene glycol at a molar ratio of 1:0.6-0.8 for 3 hours, and controlling the temperature to be 20-30°C.

4. The thermoplastic polyurethane electronic packaging leather according to claim 1, characterized in that: The chitosan gel is obtained by dissolving clean chitosan with 1% acetic acid to obtain dissolved chitosan, and then spraying the dissolved chitosan into a 1% sodium hydroxide solvent, wherein the solvent is a methanol aqueous solution containing methanol.

5. The thermoplastic polyurethane electronic packaging leather according to claim 1, characterized in that: The silicone resin is purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd.; the polyethylene glycol is purchased from Jiangsu Runfeng Synthetic Technology Co., Ltd.; and the chitosan is purchased from high-density chitosan from Shanghai MacLean Biochemical Technology Co., Ltd.

6. The thermoplastic polyurethane electronic packaging leather according to claim 1, characterized in that: The base fabric layer is TR fabric or is woven by blending 65-75% polyester fiber and 25-35% spandex fiber; the bonding layer is thermoplastic water-based polyurethane.

7. The thermoplastic polyurethane electronic packaging leather according to claim 1, characterized in that: The wear-resistant layer is composed of water-based polyurethane and glass fibers, and the glass fibers are 3mm or 6mm chopped glass fibers.

8. A method for preparing a thermoplastic polyurethane electronic packaging leather, for preparing the thermoplastic polyurethane electronic packaging leather as claimed in any one of claims 1 to 7, characterized in that: The steps include: Step 1, bonding and coating: taking a base fabric, coating the base fabric with thermoplastic waterborne polyurethane, and drying the base fabric to form a bonding germ layer; Step 2, wear-resistant lamination: take release paper and coat the wear-resistant layer slurry, dry it to obtain the wear-resistant layer, and then attach the wear-resistant layer to the bonding germ layer, and after ripening, obtain the inner base layer; Step 3, surface layer processing: take the inner base layer and place it in a coating machine, apply the surface layer slurry on the surface of the wear-resistant layer, and obtain the electronic packaging leather after drying.

9. The method for preparing a thermoplastic polyurethane electronic packaging leather according to claim 1, characterized in that: The viscosity of the thermoplastic waterborne polyurethane at room temperature is 6000-9000 cps, the coating thickness of the thermoplastic waterborne polyurethane is 0.1-0.2 mm, and the drying temperature is 60-80°C.

10. The method for preparing a thermoplastic polyurethane electronic packaging leather according to claim 1, characterized in that: The aging is a two-step aging, and the temperature of the first aging is controlled to be 100-120° C. and the time is 15 minutes; the temperature of the second aging is controlled to be 50-60° C. and the time is 12-16 hours.

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