A fabric

Abstract

The present invention relates to a fabric, comprising a fabric body and a coating formed by a liquid polyurethane coating, the coating comprising a primer formed on the fabric body and a topcoat formed on the primer. The preparation method of the liquid polyurethane coating comprises the following steps: (1) subjecting an isocyanate, a first polyol, a second polyol, and a third polyol to a prepolymerization reaction; and (2) adding a solvent, polytetramethylene glycol polyol, and a chain extender to the system after the reaction in step (1) to carry out a chain extension reaction, wherein the first polyol is one or more of polytetramethylene glycol polyol, polycarbonate polyol, and polycaprolactone polyol, and the second polyol is one or more of polypropylene oxide polyol, tetramethylene glycol polyol, and propylene oxide and ethylene oxide copolymer polyol. The fabric of the present invention has excellent cold resistance, resilience, and flexibility, is more lightweight, and has the advantages of being economical and environmentally friendly.

Description

[0001] This invention is a divisional application with an application date of August 31, 2020, application number 2020108942336, and invention name: A liquid polyurethane coating, its preparation method and application. Technical Field

[0002] The present invention particularly relates to a fabric. Background Art

[0003] At present, the low temperature resistance of clothing leather coatings on the market only stays at -20 to 30 degrees Celsius. Therefore, the cold temperature resistance of popular down jackets, mountaineering clothes, tents and sleeping bags on the market is about -20 to 30 degrees Celsius at the lowest. In extremely cold environments (-30 to 45 degrees Celsius), the cold resistance of existing clothing leather coatings cannot meet the use requirements. Moreover, in extremely cold weather, the human body's requirements for the comfort of clothing increase, so the softness and resilience of the fabric need to be improved. In addition, the coating amount of existing low-temperature resistant polyurethane coatings is relatively high, about 150 to 210g / m 2 When used for clothing or tents and sleeping bags, the fabric is thicker and heavier, making it inconvenient to fold and carry. Summary of the Invention

[0004] The object of the present invention is to provide a method for preparing a liquid polyurethane coating. The prepared liquid polyurethane coating has excellent cold resistance, resilience and flexibility.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A first aspect of the present invention provides a method for preparing a liquid polyurethane coating, comprising the following steps:

[0007] (1) prepolymerizing isocyanate, a first polyol, a second polyol, and a third polyol;

[0008] (2) adding solvent, polytetrahydrofuran polyol and chain extender to the system after step (1) reaction is completed and carrying out chain extension reaction,

[0009] The first polyol is one or more of polytetramethylene glycol polyol, polycarbonate polyol, and polycaprolactone polyol; the second polyol is one or more of polypropylene oxide polyol, tetramethylene glycol and propylene oxide copolymer polyol, and propylene oxide and ethylene oxide copolymer polyol.

[0010] In the present invention, the polycarbonate polyol is PCDL.

[0011] In the present invention, the polycaprolactone polyol is PCL.

[0012] In the present invention, the first polyol used has the characteristics of excellent cold resistance, excellent water resistance, high mechanical strength, good crystallinity, etc., while the second polyol used also has excellent cold resistance and high mechanical strength, but poor crystallinity.

[0013] Preferably, the reaction temperature of step (1) is controlled to be 80-95°C.

[0014] Preferably, the reaction temperature of step (2) is controlled to be 80-95°C.

[0015] Preferably, the isocyanate is one or more of MDI, TDI, and HMDI;

[0016] Preferably, the third polyol is one or more of polycarbonate lactone polyol, polyester polyol, and polyethylene glycol.

[0017] In the present invention, the polycarbonate lactone polyol is PPC, which is formed by copolymerization of carbon dioxide and propylene oxide.

[0018] In the present invention, the polyester polyol is prepared by condensing adipic acid, ethylene glycol and 1,4-butanediol in a molar ratio of 5-6:1.5-2.5:2-4, and the molar ratio is more preferably 5.01:2:3.

[0019] In the present invention, the number average molecular weight of the polytetrahydrofuran polyol, polypropylene oxide polyol and other polyols used in step (1) is 1500 to 3000, preferably 1800 to 2500, more preferably about 2000.

[0020] In the present invention, the number average molecular weight of the polytetrahydrofuran polyol used in step (2) is 1500 to 3000, preferably 1800 to 2500, more preferably about 2000.

[0021] Preferably, the solvent is one or more of dimethylformamide and dimethylacetamide.

[0022] Preferably, the chain extender is one or more of ethanolamine, diethylene glycol, ethylene glycol, 1,4-butanediol, and neopentyl glycol.

[0023] Preferably, the preparation method further comprises the steps of adding isocyanate in batches after the chain extension reaction is completed to react until the desired viscosity is reached, and then adding a chain terminator to terminate the reaction.

[0024] In the present invention, the viscosity range is preferably 30,000 to 200,000 cps / 65°C, more preferably 50,000 to 110,000 cps / 65°C.

[0025] More preferably, the chain terminator is one or more of ethylene glycol and malic acid.

[0026] Further preferably, the preparation method further comprises the step of adding a solvent to the reaction system to adjust the solid content after terminating the reaction.

[0027] In the present invention, the solid content is preferably adjusted in the range of 20% to 60%, more preferably 28% to 52%.

[0028] Preferably, step (1) is carried out in the presence of a solvent.

[0029] According to a specific embodiment, when the liquid polyurethane coating is a surface coating, the molar ratio of the isocyanate, the first polyol, the second polyol and the third polyol in step (1) is 10-15:2-5:0.5-1:1; the molar ratio of the polytetrahydrofuran polyol and the chain extender in step (2) is 0.05-0.2:1; and the molar ratio of the first polyol in step (1) to the polytetrahydrofuran polyol in step (2) is 0.5-2:1.

[0030] Preferably, when the liquid polyurethane coating is a surface coating, the first polyol is polytetramethylene glycol; the second polyol is polypropylene oxide polyol; the third polyol is polycarbonate lactone polyol; and the chain extender is a mixture of ethanolamine and diethylene glycol.

[0031] More preferably, the molar ratio of ethanolamine to diethylene glycol is 1 to 2:1.

[0032] According to a specific embodiment, when the liquid polyurethane coating is a primer, the molar ratio of the isocyanate, the first polyol, the second polyol and the third polyol in step (1) is 2-8:0.5-1.5:0.1-0.5:1; the molar ratio of the polytetrahydrofuran polyol and the chain extender in step (2) is 0.05-0.1:1; and the molar ratio of the first polyol in step (1) to the polytetrahydrofuran polyol in step (2) is 1-3:1.

[0033] Preferably, when the liquid polyurethane coating is a primer, the first polyol is polytetramethylene glycol; the second polyol is polypropylene oxide polyol; the third polyol is polyester polyol; and the chain extender is a mixture of ethylene glycol, ethanolamine, and diethylene glycol.

[0034] More preferably, the molar ratio of ethylene glycol, ethanolamine and diethylene glycol is 0.5-1:0.1-0.6:1.

[0035] The second aspect of the present invention also provides a liquid polyurethane coating prepared using the above preparation method.

[0036] The third aspect of the present invention also provides an application of the liquid polyurethane coating prepared by the above preparation method in fabric coating.

[0037] In the present invention, the primer is first applied on the fabric to form a primer layer, and then the topcoat is applied on the primer layer to form a topcoat.

[0038] The fourth aspect of the present invention also provides a fabric comprising a coating formed by the above-mentioned coating.

[0039] Furthermore, the coating includes a base coating formed on the fabric body and a top coating formed on the base coating.

[0040] The fifth aspect of the present invention also provides a method for preparing a fabric coating, wherein the liquid polyurethane coating prepared by the above preparation method is applied to the fabric, and the coating is obtained by drying and recovering the solvent.

[0041] Preferably, the coating amount of the liquid polyurethane coating on the fabric is 50-120 g / m 2 .

[0042] In the present invention, the total coating amount of the bottom layer and the top layer is 50 to 120 g / m 2 When producing fabrics, the specific coating amount of the surface layer and the bottom layer can be selected according to needs.

[0043] The polyurethane coating of the present invention is liquid-type, has good resin stability, does not require the addition of film-forming aids such as curing agents and cross-linking agents during preparation, and is more convenient to operate.

[0044] The invention prepolymerizes a first polyol (one or more of polytetramethylene oxide polyol, polycarbonate polyol, and polycaprolactone polyol) as a soft segment raw material, a second polyol (one or more of polypropylene oxide polyol, tetramethylene oxide copolymerized polyol, and propylene oxide copolymerized polyol) and a third polyol, and then uses the polytetramethylene oxide as a soft segment raw material and a chain extender as a hard segment raw material for chain extension. Compared with a polyurethane coating synthesized by a traditional one-step method, the invention has significantly improved cold resistance, and also improved resilience and flexibility.

[0045] The preparation method of the liquid polyurethane coating of the present invention can use dimethylformamide or dimethylacetamide as a reaction solvent. The prepared liquid polyurethane coating is directly coated on a fabric and dried to obtain a coating. The reaction solvent can be recycled and reused during the drying process, thereby saving resources and reducing costs. In addition, the preparation method of the present invention does not generate waste gas or waste liquid during industrial production, and is more environmentally friendly.

[0046] The liquid polyurethane coating of the present invention can be applied to clothing coatings, and the clothing prepared thereby can improve the comfort of the body under harsh natural conditions. Moreover, the coating amount of the liquid polyurethane coating of the present invention on the fabric is 50 to 120 g / m 2 Compared with the coatings on the market, the coating amount is small. Therefore, the fabric using the liquid polyurethane coating of the present invention not only has excellent waterproof and cold-proof properties, but is also light, easy to fold and carry, and is more suitable for military camouflage uniforms.

[0047] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0048] The liquid polyurethane coating prepared using the method of the present invention has excellent cold resistance, resilience and flexibility, and has a low coating amount, which can make the fabric lighter; the preparation method of the present invention does not generate waste gas or waste liquid during operation, and the solvent can be recycled and reused, which has the advantages of economy and environmental protection and is more suitable for industrial production. DETAILED DESCRIPTION

[0049] The present invention is further described below by way of specific examples, which are not intended to limit the present invention and are merely illustrative. The implementation conditions employed in the examples may be further adjusted according to the specific requirements of use, and the implementation conditions not specified are conventional conditions in the industry.

[0050] The reagents and materials used in the present invention can be obtained commercially.

[0051] Embodiment 1:

[0052] Polyurethane topcoat:

[0053] (1) 0.432 mol of isocyanate (MDI), 0.104 mol of polytetramethylene glycol (number average molecular weight of about 2000), 0.024 mol of polypropylene oxide polyol (number average molecular weight of about 2000), 0.032 mol of polycarbonate lactone polyol (number average molecular weight of about 2000) and 150 g of dimethylformamide were added to a reaction vessel and reacted at 80-85°C for 2 h.

[0054] (2) To the system after the reaction in step (1) was completed, 470 g of dimethylformamide, 0.08 mol of polytetrahydrofuran polyol (number average molecular weight of about 2000), 0.5 mol of ethanolamine and 0.32 mol of diethylene glycol were added, and the mixture was reacted at 80-85° C. for 1.5 h.

[0055] (3) After the reaction in step (2) is completed, isocyanate (MDI) is added in three batches, with the first batch amount being 0.314 mol, the second batch amount being 0.209 mol, and the third batch amount being 0.105 mol. The reaction is carried out at 80-85°C, and samples are taken. The viscosity of the reaction solution is detected using an NDJ-4 viscometer. When the viscosity of the reaction solution is 80,000-110,000 cps / 65°C, 0.04 mol of ethylene glycol is added to terminate the reaction.

[0056] (4) Dimethylformamide was added to the system after the reaction was terminated in step (3) to adjust the solid content to 30±1%, and the solid content was determined using method A of GB1725-79.

[0057] Example 2:

[0058] Polyurethane topcoat:

[0059] (1) 0.432 mol of isocyanate (MDI), 0.084 mol of polytetramethylene glycol (number average molecular weight of about 2000), 0.024 mol of polypropylene oxide polyol (number average molecular weight of about 2000), 0.032 mol of polycarbonate lactone polyol (number average molecular weight of about 2000) and 150 g of dimethylformamide were added to a reaction vessel and reacted at 80-85° C. for 2 h.

[0060] (2) To the system after the reaction in step (1) was completed, 470 g of dimethylformamide, 0.1 mol of polytetrahydrofuran polyol (number average molecular weight of about 2000), 0.5 mol of ethanolamine and 0.32 mol of diethylene glycol were added, and the mixture was reacted at 80-85° C. for 1.5 h.

[0061] (3) Isocyanate (MDI) was added to the system after the reaction in step (2) in three batches, with the first batch amount being 0.314 mol, the second batch amount being 0.209 mol, and the third batch amount being 0.105 mol. The reaction was carried out at 80-85°C until the viscosity of the reaction liquid reached 80,000-110,000 cps / 65°C, and 0.04 mol of ethylene glycol was added to terminate the reaction.

[0062] (4) Dimethylformamide was added to the system after the reaction was terminated in step (3) to adjust the solid content to 30±1%.

[0063] In this embodiment, the viscosity and solid content detection methods are the same as in Example 1.

[0064] Example 3:

[0065] Polyurethane topcoat:

[0066] (1) 0.432 mol of isocyanate (MDI), 0.104 mol of polytetramethylene glycol (number average molecular weight of about 2000), 0.024 mol of polypropylene oxide polyol (number average molecular weight of about 2000), and 0.032 mol of polycarbonate lactone polyol (number average molecular weight of about 2000) were added to a reaction vessel and reacted at 80-85°C for 2 h.

[0067] (2) To the system after the reaction in step (1) was completed, 620 g of dimethylformamide, 0.08 mol of polytetrahydrofuran polyol (number average molecular weight of about 2000), 0.5 mol of ethanolamine and 0.32 mol of diethylene glycol were added, and the mixture was reacted at 80-85° C. for 1.5 h.

[0068] (3) Isocyanate (MDI) was added to the system after the reaction in step (2) in three batches, with the first batch amount being 0.314 mol, the second batch amount being 0.209 mol, and the third batch amount being 0.105 mol. The reaction was carried out at 80-85°C until the viscosity of the reaction liquid reached 80,000-110,000 cps / 65°C, and 0.04 mol of ethylene glycol was added to terminate the reaction.

[0069] (4) Dimethylformamide was added to the system after the reaction was terminated in step (3) to adjust the solid content to 30±1%.

[0070] In this embodiment, the viscosity and solid content detection methods are the same as in Example 1.

[0071] Comparative Example 1:

[0072] Polyurethane topcoat:

[0073] (1) 0.432 mol of isocyanate (MDI), 0.184 mol of polytetramethylene glycol (number average molecular weight of about 2000), 0.024 mol of polypropylene oxide polyol (number average molecular weight of about 2000), 0.032 mol of polycarbonate lactone polyol (number average molecular weight of about 2000), 0.5 mol of ethanolamine, 0.32 mol of diethylene glycol and 150 g of dimethylformamide were added to a reaction vessel and reacted at 80-85 degrees for 2 hours.

[0074] (2) 0.628 mol of isocyanate (MDI) was added to the system after the reaction in step (1), and the reaction was carried out at 80-85°C until the viscosity of the reaction liquid reached 80,000-110,000 cps / 65°C. 0.04 mol of ethylene glycol was added to terminate the reaction.

[0075] (3) Add dimethylformamide and toluene to the system after the reaction is terminated in step (2) to adjust the solid content to 30±1%.

[0076] In this comparative example, the viscosity and solid content detection methods are the same as those in Example 1.

[0077] Example 4:

[0078] Polyurethane primer:

[0079] (1) 0.654 mol of isocyanate (TDI), 0.1565 mol of polytetramethylene glycol (number average molecular weight of about 2000), 0.0463 mol of polypropylene oxide polyol (number average molecular weight of about 2000), 0.139 mol of polyester polyol (polymerized by adipic acid, ethylene glycol, and 1,4-butanediol in a molar ratio of 5.01:2:3, with a number average molecular weight of about 2000) and 190 g of dimethylformamide were added to a reaction vessel and reacted at 90-95°C for 2 h.

[0080] (2) To the system after the reaction in step (1) was completed, 470 g of dimethylformamide, 0.075 mol of polytetrahydrofuran polyol (number average molecular weight of about 2000), 0.37 mol of ethylene glycol, 0.185 mol of ethanolamine and 0.485 mol of diethylene glycol were added, and the mixture was reacted at 90-95° C. for 1.5 h.

[0081] (3) Isocyanate (MDI) was added to the system after the reaction in step (2) in three batches, with the first addition amount being 0.4014 mol, the second addition amount being 0.2676 mol, and the third addition amount being 0.1338 mol. The reaction was carried out at 80-85°C until the viscosity of the reaction liquid reached 50,000-60,000 cps / 65°C, and 0.04 mol of ethylene glycol was added to terminate the reaction.

[0082] (4) Dimethylformamide was added to the system after the reaction was terminated in step (3) to adjust the solid content to 50±1%.

[0083] In this embodiment, the viscosity and solid content detection methods are the same as in Example 1.

[0084] Example 5:

[0085] Polyurethane primer:

[0086] (1) 0.654 mol of isocyanate (TDI), 0.139 mol of polytetramethylene glycol (number average molecular weight of about 2000), 0.0463 mol of polypropylene oxide polyol (number average molecular weight of about 2000), 0.139 mol of polyester polyol (polymerized by adipic acid, ethylene glycol, and 1,4-butanediol in a molar ratio of 5.01:2:3, with a number average molecular weight of about 2000) and 190 g of dimethylformamide were added to a reaction vessel and reacted at 90-95° C. for 2 h.

[0087] (2) To the system after the reaction in step (1) was completed, 470 g of dimethylformamide, 0.0925 mol of polytetrahydrofuran polyol (number average molecular weight of about 2000), 0.37 mol of ethylene glycol, 0.185 mol of ethanolamine and 0.485 mol of diethylene glycol were added, and the mixture was reacted at 90-95° C. for 1.5 h.

[0088] (3) Isocyanate (MDI) was added to the system after the reaction in step (2) in three batches, with the first addition amount being 0.4014 mol, the second addition amount being 0.2676 mol, and the third addition amount being 0.1338 mol. The reaction was carried out at 80-85°C until the viscosity of the reaction liquid reached 50,000-60,000 cps / 65°C, and 0.04 mol of ethylene glycol was added to terminate the reaction.

[0089] (4) Dimethylformamide was added to the system after the reaction was terminated in step (3) to adjust the solid content to 50±1%.

[0090] In this embodiment, the viscosity and solid content detection methods are the same as in Example 1.

[0091] Example 6:

[0092] Polyurethane primer:

[0093] (1) 0.654 mol of isocyanate (TDI), 0.139 mol of polytetramethylene glycol (number average molecular weight of about 2000), 0.0463 mol of polypropylene oxide polyol (number average molecular weight of about 2000), and 0.139 mol of polyester polyol (polymerized by adipic acid, ethylene glycol, and 1,4-butanediol in a molar ratio of 5.01:2:3, with a number average molecular weight of about 2000) were added to a reaction vessel and reacted at 90-95°C for 2 h.

[0094] (2) To the system after the reaction in step (1) was completed, 660 g of dimethylformamide, 0.0925 mol of polytetrahydrofuran polyol (number average molecular weight of about 2000), 0.37 mol of ethylene glycol, 0.185 mol of ethanolamine and 0.485 mol of diethylene glycol were added, and the mixture was reacted at 90-95° C. for 1.5 h.

[0095] (3) Isocyanate (MDI) was added to the system after the reaction in step (2) in three batches, with the first addition amount being 0.4014 mol, the second addition amount being 0.2676 mol, and the third addition amount being 0.1338 mol. The reaction was carried out at 80-85°C until the viscosity of the reaction liquid reached 50,000-60,000 cps / 65°C, and 0.04 mol of ethylene glycol was added to terminate the reaction.

[0096] (4) Dimethylformamide was added to the system after the reaction was terminated in step (3) to adjust the solid content to 50±1%.

[0097] In this embodiment, the viscosity and solid content detection methods are the same as in Example 1.

[0098] Comparative Example 2:

[0099] Polyurethane primer:

[0100] (1) 0.654 mol of isocyanate (TDI), 0.2315 mol of polytetramethylene glycol (number average molecular weight of about 2000), 0.0463 mol of polypropylene oxide polyol (number average molecular weight of about 2000), 0.139 mol of polyester polyol (polymerized by adipic acid, ethylene glycol, and 1,4-butanediol in a molar ratio of 5.01:2:3, with a number average molecular weight of about 2000), 0.37 mol of ethylene glycol, 0.185 mol of ethanolamine, 0.485 mol of diethylene glycol, and 190 g of dimethylformamide were added to a reaction vessel and reacted at 90-95° C. for 2 hours.

[0101] (2) 0.8028 mol of isocyanate (MDI) is added to the system after the reaction in step (1), and the reaction is carried out at 80-85°C until the viscosity of the reaction liquid reaches 50,000-60,000 cps / 65°C. 0.04 mol of ethylene glycol is added to terminate the reaction.

[0102] (3) Add dimethylformamide and toluene to the system after the reaction is terminated in step (2) to adjust the solid content to 50±1%.

[0103] In this comparative example, the viscosity and solid content detection methods are the same as those in Example 1.

[0104] The polyurethane primer of Example 4 was conventionally applied to the front side of the nylon cloth, and dried by conventional methods to obtain a polyurethane primer coating. The polyurethane topcoat of Example 1 was conventionally applied to the polyurethane primer coating, and dried by conventional methods to obtain a polyurethane topcoat coating. Finally, a nylon cloth product with a polyurethane coating on the front side was obtained, which was recorded as Finished Product 1. The total coating amount of the primer and topcoat was about 80 g / m 2 The dimethylformamide was recovered and reused during the drying process. Similarly, using the same coating amount and coating method as for Finished Product 1, Examples 1-6 were combined according to the combination method in Table 1 to produce Finished Products 2-9. Using the same coating amount and coating method as for Finished Product 1, Comparative Examples 1 and 2 were used to produce Finished Product 10. Finished Products 1-10 were tested for folding fastness using FZ / T01007-2008. The test items and results are shown in Table 1.

[0105] Table 1

[0106]

[0107] The polyurethane topcoat coatings of Example 1, Example 2, Example 3, and Comparative Example 1, and the polyurethane basecoat coatings of Example 4, Example 5, Example 6, and Comparative Example 2 were respectively coated on a flat release paper using a 10 dmm wire rod in a conventional coating manner, and dried in a conventional manner to obtain a polyurethane film with a thickness of 6 dmm. The polyurethane films were removed and the tensile properties of each polyurethane film were tested using GB / T1040-2006. The test items and test results are shown in Tables 2 and 3.

[0108] Table 2

[0109]

[0110]

[0111] Table 3

[0112]

[0113] Table 1 shows that the low-temperature folding resistance of finished products 1 to 9 at -45°C fully meets the national standard, while the low-temperature folding resistance of finished product 10 at -45°C does not meet the national standard; Table 2 shows that at room temperature, Examples 1 to 3 have higher elongation than Comparative Example 1, and Examples 4 to 6 also have higher elongation than Comparative Example 2. Combining the results of Tables 1, 2 and 3, it can be seen that the preparation method of the present invention can effectively improve the cold resistance, resilience and flexibility of the polyurethane coating.

[0114] The above examples are merely exemplary embodiments of the present invention and are not intended to limit the scope of the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the spirit and scope of protection of the present invention, and such modifications or equivalent substitutions shall also be deemed to fall within the scope of protection of the present invention.

Claims

1. A fabric comprising a fabric body and a coating formed of a liquid polyurethane coating, wherein the coating comprises a primer formed on the fabric body and a topcoat formed on the primer, characterized in that: The steps of the preparation method of the liquid polyurethane coating are: (1) prepolymerizing isocyanate, a first polyol, a second polyol, and a third polyol; (2) adding solvent, polytetrahydrofuran polyol and chain extender to the system after step (1) reaction is completed and carrying out chain extension reaction; (3) After the chain extension reaction is completed, isocyanate is added in batches to react until the desired viscosity is reached, and then a chain terminator is added to terminate the reaction; (4) selectively adding a solvent to the reaction system to adjust the solid content, The first polyol is one or more of polytetramethylene glycol polyol, polycarbonate polyol, and polycaprolactone polyol; the second polyol is one or more of polypropylene oxide polyol, tetramethylene glycol copolyol, and propylene oxide copolyol; the third polyol is one or more of polycarbonate lactone polyol, polyester polyol, and polyethylene glycol; the chain terminator is one or more of ethylene glycol and malic acid; When the liquid polyurethane coating is a surface coating, the molar ratio of the isocyanate, the first polyol, the second polyol and the third polyol in step (1) is 10-15:2-5:0.5-1:1; the molar ratio of the polytetrahydrofuran polyol and the chain extender in step (2) is 0.05-0.2:1; the molar ratio of the first polyol in step (1) to the polytetrahydrofuran polyol in step (2) is 0.5-2:1; When the liquid polyurethane coating is a primer, the molar ratio of the isocyanate, the first polyol, the second polyol and the third polyol in step (1) is 2-8:0.5-1.5:0.1-0.5:1; the molar ratio of the polytetrahydrofuran polyol and the chain extender in step (2) is 0.05-0.1:1; and the molar ratio of the first polyol in step (1) to the polytetrahydrofuran polyol in step (2) is 1-3:

1.

2. The fabric according to claim 1, characterized in that: The reaction temperature of step (1) is controlled to be 80-95°C; the reaction temperature of step (2) is controlled to be 80-95°C.

3. The fabric according to claim 1, characterized in that: The isocyanate is one or more of MDI, TDI, and HMDI; The third polyol is one or more of polycarbonate lactone polyol, polyester polyol, and polyethylene glycol; The solvent is one or more of dimethylformamide and dimethylacetamide; The chain extender is one or more of ethanolamine, diethylene glycol, ethylene glycol, 1,4-butanediol and neopentyl glycol.

4. The fabric according to claim 1, characterized in that: In step (3), the viscosity range is 30,000 to 200,000 cps / 65°C; in step (4), the solid content is adjusted to 20% to 60%, and the solvent is dimethylformamide.

5. The fabric according to claim 1, characterized in that: The reaction in step (1) is carried out in the presence of a solvent.

6. The fabric according to any one of claims 1 to 5, characterized in that: When the liquid polyurethane coating is a surface coating, the first polyol is polytetramethylene glycol; the second polyol is polypropylene oxide polyol; the third polyol is polycarbonate lactone polyol; and the chain extender is a mixture of ethanolamine and diethylene glycol. When the liquid polyurethane coating is a primer, the first polyol is polytetramethylene glycol; the second polyol is polypropylene oxide polyol; the third polyol is polyester polyol; and the chain extender is a mixture of ethylene glycol, ethanolamine, and diethylene glycol.

7. The fabric according to claim 6, characterized in that: When the liquid polyurethane coating is a surface coating, the molar ratio of the ethanolamine and diethylene glycol is 1 to 2:1; when the liquid polyurethane coating is a base coating, the molar ratio of the ethylene glycol, ethanolamine and diethylene glycol is 0.5 to 1:0.1 to 0.6:

1.

8. The fabric according to claim 1, characterized in that: First, the bottom coating is coated on the fabric, and the solvent is recovered after drying to form the bottom coating. Then, the top coating is coated on the bottom coating, and the solvent is recovered after drying to form the top coating.

9. The fabric according to claim 8, characterized in that: The fabric body is nylon cloth.

10. The fabric according to claim 1, characterized in that: The coating amount of the liquid polyurethane coating on the fabric body is 50-120g / m 2 .

Images