A high water pressure, high moisture permeability polyurethane film and its preparation method, and fabric.

Abstract

This invention provides a high-water-pressure, high-moisture-permeable polyurethane film, its preparation method, and a fabric, belonging to the field of polyurethane films. By mass percentage, it is prepared from the following raw materials: 30-40% highly crosslinked polyester polyol, 20-30% hydrophilic polyether polyol, 25-35% polyisocyanate, 3-5% nano-silica, 0.5-1.0% nano-calcium carbonate, 0.5-1.0% carbon nanotubes, 8-12% special hydrophilic chain extender, 1-2% anti-aging agent, 0.5-1% antistatic agent, 0.5-1% ultraviolet absorber, 3-5% multifunctional high-efficiency crosslinking agent, and the balance being solvent. By utilizing highly crosslinked polyester polyol, hydrophilic polyether polyol, polyisocyanate, nano-silica, nano-calcium carbonate, and carbon nanotubes to form a polyurethane formulation system, it balances the high water-pressure waterproof performance and high moisture permeability of polyurethane films, solving the problem of insufficient waterproof and moisture-permeable performance in existing PU polyurethane materials, and meeting the stringent performance requirements of high-end applications.

Description

Technical Field

[0001] This invention relates to the field of polyurethane films, and particularly to a high water pressure, high moisture permeability polyurethane film, its preparation method, and its fabric. Background Technology

[0002] With the rapid development of the times, the demand in the fabric market is increasing day by day. Beyond the most basic functions of protection and decoration, there is a greater demand for the protective and comfortable properties of clothing in certain special working environments and daily life, leading to the emergence of waterproof and breathable membrane materials. Waterproof and breathable membranes are functional membrane materials that combine excellent water permeability resistance with moisture permeability. They are typically combined with natural or synthetic fiber fabrics to manufacture functional clothing with unique protective and comfortable properties, such as mountaineering clothing, ski suits, waterproof jackets, field uniforms, chemical protective suits, as well as shoes, socks, and gloves. Clothing made with waterproof and breathable membranes as the core material can prevent rain and snow from penetrating and protect against harmful external conditions while allowing sweat produced by the body to escape as moisture, thus ensuring the safety and comfort of the wearer. Therefore, they are playing an increasingly important role in people's production activities and daily lives.

[0003] Existing waterproof and breathable membranes have certain limitations in practical applications. It is difficult to balance waterproofness and breathability. For membrane materials with good breathability, their hydrostatic pressure resistance is often insufficient, and water seepage is prone to occur under high water pressure. For membrane materials with good waterproofness, it is difficult to build efficient water vapor transmission channels inside, making it difficult to achieve a balance between high breathability and high waterproof performance, which limits the application of PU polyurethane materials in the field of professional outdoor equipment. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a high-water-pressure, high-permeability polyurethane film, its preparation method, and a fabric. By designing the raw material formulation and preparation process, the insufficient waterproof and permeable properties of existing PU polyurethane materials are solved, meeting the stringent performance requirements of high-end applications. The specific technical solution is as follows:

[0005] On one hand, the present invention provides a high water pressure and high moisture permeability polyurethane film, which is prepared by weight percentage from the following raw materials: 25-35% highly crosslinked polyester polyol, 15-25% hydrophilic polyether polyol, 15-25% polyisocyanate, 3-5% nano silica, 0.5-1.0% nano calcium carbonate, 0.5-1.0% carbon nanotubes, 8-12% special hydrophilic chain extender, 1-2% anti-aging agent, 0.5-1% antistatic agent, 0.5-1% ultraviolet absorber, 3-5% multifunctional high-efficiency crosslinking agent, and the balance being solvent.

[0006] The above technical solution utilizes highly cross-linked polyester polyols, hydrophilic polyether polyols, polyisocyanates, nano-silica, nano-calcium carbonate, and carbon nanotubes to form a polyurethane formulation system, which takes into account both the high water pressure waterproof performance and high moisture permeability of the polyurethane film. The three-dimensional network structure formed by highly cross-linked polyester polyols provides a high-strength skeleton for polyurethane, enabling it to withstand higher hydrostatic pressure and reducing structural damage caused by water molecule penetration. Hydrophilic segments in the hydrophilic polyether polyol molecular chains adsorb water vapor molecules through hydrogen bonds, constructing continuous moisture-permeable channels for efficient moisture permeability. Polyisocyanates react with polyols to form a tighter cross-linked network, further enhancing the material's waterproof performance. Nano-silica, nano-calcium carbonate, and carbon nanotubes are added to the system after surface modification. Nano-silica and nano-calcium carbonate fill the spaces between polyurethane molecular chains, increasing intermolecular interactions and improving the membrane's mechanical properties and density. Carbon nanotubes enhance the membrane's strength and conductivity, jointly improving the material's stability under high water pressure. Special hydrophilic chain extenders further improve the membrane's moisture permeability while ensuring high hydrostatic pressure resistance, while the addition of anti-aging agents, antistatic agents, and UV absorbers optimizes the material's overall performance and extends its service life.

[0007] Optionally, the highly crosslinked polyester polyol is prepared by polycondensation reaction of pyromellitic dianhydride, glycerol, and ethylene glycol, wherein the multifunctional monomer accounts for 20-30% of the total monomer mass. Here, a highly crosslinked polyester polyol is used, wherein the multifunctional monomer is pyromellitic dianhydride, accounting for 20-30% of the total monomer mass, more preferably 24-26%. The multifunctional monomer and monofunctional monomer are combined in a specific ratio, which makes the formed three-dimensional network structure more stable and able to withstand higher hydrostatic pressure, thereby reducing structural damage caused by water molecule penetration.

[0008] Optionally, the hydrophilic polyether polyol is obtained by block copolymerization of polyethylene glycol and propylene oxide, wherein the polyethylene glycol segments account for 30-50% of the total mass of the hydrophilic polyether polyol, and more preferably, the polyethylene glycol segments account for 35-45% of the total mass of the hydrophilic polyether polyol.

[0009] Ordinary polyether polyols have poor hydrophilicity and cannot construct efficient water vapor transport channels. Here, hydrophilic polyether polyol molecular chains are used, and the proportion of polyethylene glycol segments in the total mass of hydrophilic polyether polyol is controlled within a certain range. Water vapor molecules are adsorbed through hydrogen bonds in the polyethylene glycol segments to construct several continuous moisture-permeable channels, thereby achieving efficient moisture permeability.

[0010] Optionally, the polyisocyanate is an aromatic isocyanate containing three or more isocyanate groups. The isocyanate groups react with the polyol to form a denser cross-linked network, further enhancing the stability and water pressure resistance of the three-dimensional network structure, thereby enhancing the durable waterproof performance of the film.

[0011] Optionally, the polyisocyanate is selected from one of TDI trimer, polymeric MDI, substituted phenyl isocyanate trimer, and TDI-trimethylolpropane prepolymer.

[0012] Optionally, the special hydrophilic chain extender is a polymer containing multiple hydroxyl groups, with the hydroxyl content accounting for 15-25% of the mass of the special hydrophilic chain extender. Here, the hydroxyl groups react with the isocyanate groups, and the hydrophilic chain extender imparts selective moisture permeability to the polyurethane film while maintaining the mechanical properties of the polymer. Combined with the continuous moisture permeability channels constructed by the polyethylene glycol segments, it further improves the moisture permeability of the membrane while ensuring high hydrostatic pressure resistance.

[0013] Optionally, the special hydrophilic chain extender is selected from one or more of dimethylolpropionic acid, dimethylolbutyric acid, and dihydroxysulfonate.

[0014] Optionally, the multifunctional high-efficiency crosslinking agent is an aziridine crosslinking agent.

[0015] Optionally, the polyurethane has a molecular weight between 4,000 and 8,000, and a number-average molecular weight of 5,000 to 6,000, with a molecular weight distribution that satisfies a polydispersity index (PDI) of 1.6 to 1.8.

[0016] Optionally, the solvent is selected from ethyl acetate, PMA, S-100, S-150, and methylal.

[0017] On the other hand, the present invention also provides a method for preparing the above-mentioned high water pressure and high moisture permeability polyurethane film, comprising the following steps:

[0018] Step 1: Vacuum dehydrate the highly crosslinked polyester polyol at 100-110℃ for 2-3 hours;

[0019] Step 2: Cool down to 70-80℃, add polyisocyanate in proportion, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0020] Step 3: Add a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0021] Step 4: After surface modification treatment of nano-silica, nano-calcium carbonate and carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0022] Step 5: Add the anti-aging agent, antistatic agent, ultraviolet absorber and multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0023] Step 6: Slowly add solvent to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a doctor blade to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0024] In another aspect, the present invention also provides a fabric comprising a fabric body and the aforementioned polyurethane film attached to one side surface of the fabric body.

[0025] The beneficial effects of the technical solution in this invention include at least the following:

[0026] (1) A polyurethane formulation system is formed by using highly cross-linked polyester polyols, hydrophilic polyether polyols, polyisocyanates, nano silica, nano calcium carbonate and carbon nanotubes, which takes into account the high water pressure waterproof performance and high moisture permeability of polyurethane films. The three-dimensional network structure formed by highly cross-linked polyester polyols provides a high-strength skeleton for polyurethane, enabling it to withstand higher hydrostatic pressure and reducing structural damage caused by water molecule penetration. Hydrophilic segments in the hydrophilic polyether polyol molecular chains adsorb water vapor molecules through hydrogen bonds, constructing continuous moisture-permeable channels for efficient moisture permeability. Polyisocyanates react with polyols to form a tighter cross-linked network, further enhancing the material's waterproof performance. Nano-silica, nano-calcium carbonate, and carbon nanotubes are added to the system after surface modification. Nano-silica and nano-calcium carbonate fill the spaces between PU molecular chains, increasing intermolecular interactions and improving the membrane's mechanical properties and density. Carbon nanotubes enhance the membrane's strength and conductivity, jointly improving the material's stability under high water pressure. Special hydrophilic chain extenders further improve the membrane's moisture permeability while ensuring high hydrostatic pressure resistance, while the addition of anti-aging agents, antistatic agents, and UV absorbers optimizes the material's overall performance and extends its service life.

[0027] (2) The high-strength cross-linked network formed by the high-cross-linked polyester polyol and polyisocyanate, combined with the reinforcing effect of nanomaterials, enables the prepared polyurethane membrane to withstand hydrostatic pressure exceeding 30 kPa, effectively resisting the penetration of water molecules under high water pressure.

[0028] (3) The continuous moisture-permeable channels constructed by hydrophilic polyether polyols and special hydrophilic chain extenders enable the material to achieve a moisture permeability of 10,000 g / m³. 2 For more than 24 hours, ensure that water vapor is quickly discharged.

[0029] (4) The addition of anti-aging agents, antistatic agents and ultraviolet absorbers endows the material with good anti-aging, antistatic and anti-ultraviolet properties, extending the service life of the material in complex environments; at the same time, reinforcing materials such as carbon nanotubes improve the mechanical properties of the material and meet the needs of high-end applications. Detailed Implementation

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0031] This embodiment solves the problem of insufficient waterproof and breathable properties of existing PU polyurethane materials by designing the raw material formulation and preparation process, thus meeting the stringent requirements of high-end application scenarios for material performance.

[0032] On one hand, this embodiment provides a high water pressure and high moisture permeability polyurethane film, which is prepared from the following raw materials by mass percentage: 25-35% highly crosslinked polyester polyol, 15-25% hydrophilic polyether polyol, 15-25% polyisocyanate, 3-5% nano silica, 0.5-1.0% nano calcium carbonate, 0.5-1.0% carbon nanotubes, 8-12% special hydrophilic chain extender, 1-2% anti-aging agent, 0.5-1% antistatic agent, 0.5-1% ultraviolet absorber, 3-5% multifunctional high-efficiency crosslinking agent, and the balance being solvent.

[0033] In a preferred embodiment, the highly crosslinked polyester polyol is prepared by polycondensation reaction of pyromellitic dianhydride, glycerol and ethylene glycol, wherein the multifunctional monomer accounts for 20-30% of the total monomer mass.

[0034] In a preferred embodiment, the hydrophilic polyether polyol is obtained by block copolymerization of polyethylene glycol and propylene oxide, wherein the polyethylene glycol segments account for 30-50% of the total mass of the hydrophilic polyether polyol, and more preferably, the polyethylene glycol segments account for 35-45% of the total mass of the hydrophilic polyether polyol.

[0035] In a preferred embodiment, the polyisocyanate is an aromatic isocyanate containing three or more isocyanate groups.

[0036] In a preferred embodiment, the special hydrophilic chain extender is a polymer containing multiple hydroxyl groups, and the hydroxyl content accounts for 15-25% of the mass of the special hydrophilic chain extender.

[0037] In a preferred embodiment, the special hydrophilic chain extender is selected from one or more of dimethylolpropionic acid, dimethylolbutyric acid, dihydroxy ester, and sodium 1,2-dihydroxy-3-propanesulfonate.

[0038] In a preferred embodiment, the multifunctional high-efficiency crosslinking agent is a aziridine crosslinking agent.

[0039] In a preferred embodiment, the polyurethane has a molecular weight between 4000 and 8000, with a number-average molecular weight of 5000-6000, and a polydispersity index (PDI) of 1.6-1.8. In actual experiments, it was found that the molecular weight distribution of the polyurethane significantly affects the moisture permeability and high-pressure waterproof performance of the film after formation. Controlling the molecular weight distribution of the polyurethane by adjusting the types and ratios of highly crosslinked polyester polyols, hydrophilic polyether polyols, polyisocyanates, and special hydrophilic chain extenders, as well as by optimizing the process design, is one of the key factors in achieving high moisture permeability and high-pressure waterproof performance.

[0040] In a preferred embodiment, the solvent is selected from ethyl acetate, PMA, S-100, S-150, and methylal.

[0041] On the other hand, this embodiment also provides a method for preparing the above-mentioned high water pressure and high moisture permeability polyurethane film, comprising the following steps:

[0042] Step 1: Dehydrate the highly cross-linked polyester polyol under vacuum at 100-110℃ for 2-3 hours; then add the highly cross-linked polyester polyol and the hydrophilic polyether polyol into the reactor in proportion and mix them. Control the temperature at 80-100℃ and stir for 30-60 minutes to obtain a polyol mixture.

[0043] Step 2: Cool down to 70-80℃, add polyisocyanate in proportion, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0044] Step 3: Add a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0045] Step 4: After surface modification treatment of nano-silica, nano-calcium carbonate and carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0046] Step 5: Add the anti-aging agent, antistatic agent, ultraviolet absorber and multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0047] Step 6: Slowly add solvent to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a doctor blade to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0048] The beneficial effects of the technical solution in this embodiment will be further evaluated below through several examples and comparative examples.

[0049] Example 1:

[0050] The preparation method of the high water pressure and high moisture permeability polyurethane film in this embodiment includes the following steps:

[0051] Step 1: Vacuum dehydrate the highly cross-linked polyester polyol at 100-110℃ for 2-3 hours; then add 30 parts by weight of the highly cross-linked polyester polyol and 20 parts by weight of the hydrophilic polyether polyol into the reactor for mixing, control the temperature at 80-100℃, and stir for 30-60 minutes to obtain a polyol mixture.

[0052] Step 2: Cool down to 70-80℃, add 20 parts by weight of polyisocyanate, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0053] Step 3: Add 10 parts by weight of a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0054] Step 4: After surface modification treatment of 4 parts by mass of nano-silica, 0.8 parts by mass of nano-calcium carbonate and 0.8 parts by mass of carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0055] Step 5: Add 1.5 parts by weight of anti-aging agent, 0.8 parts by weight of antistatic agent, 0.8 parts by weight of ultraviolet absorber and 4 parts by weight of multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0056] Step 6: Slowly add ethyl acetate to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a scraper to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0057] Example 2:

[0058] The preparation method of the high water pressure and high moisture permeability polyurethane film in this embodiment includes the following steps:

[0059] Step 1: Vacuum dehydrate the highly crosslinked polyester polyol at 100-110℃ for 2-3 hours; then add 35 parts by weight of the highly crosslinked polyester polyol and 25 parts by weight of the hydrophilic polyether polyol into the reactor for mixing, control the temperature at 80-100℃, and stir for 30-60 minutes to obtain a polyol mixture.

[0060] Step 2: Cool down to 70-80℃, add 15 parts by mass of polyisocyanate, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0061] Step 3: Add 8 parts by weight of a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0062] Step 4: After surface modification treatment of 4 parts by mass of nano-silica, 0.6 parts by mass of nano-calcium carbonate and 0.9 parts by mass of carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0063] Step 5: Add 1.5 parts by weight of anti-aging agent, 0.6 parts by weight of antistatic agent, 0.6 parts by weight of ultraviolet absorber and 4 parts by weight of multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0064] Step 6: Slowly add ethyl acetate to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a scraper to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0065] Example 3:

[0066] The preparation method of the high water pressure and high moisture permeability polyurethane film in this embodiment includes the following steps:

[0067] Step 1: Vacuum dehydrate the highly crosslinked polyester polyol at 100-110℃ for 2-3 hours; then add 25 parts by mass of the highly crosslinked polyester polyol and 20 parts by mass of the hydrophilic polyether polyol into the reactor for mixing, control the temperature at 80-100℃, and stir for 30-60 minutes to obtain a polyol mixture.

[0068] Step 2: Cool down to 70-80℃, add 25 parts by mass of polyisocyanate, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0069] Step 3: Add 12 parts by weight of a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0070] Step 4: After surface modification treatment of 4 parts by mass of nano-silica, 0.8 parts by mass of nano-calcium carbonate and 0.6 parts by mass of carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0071] Step 5: Add 1.5 parts by weight of anti-aging agent, 0.8 parts by weight of antistatic agent, 0.8 parts by weight of ultraviolet absorber and 4 parts by weight of multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0072] Step 6: Slowly add solvent to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a doctor blade to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0073] Example 4:

[0074] The preparation method of the high water pressure and high moisture permeability polyurethane film in this embodiment includes the following steps:

[0075] Step 1: Vacuum dehydrate the highly crosslinked polyester polyol at 100-110℃ for 2-3 hours; then add 35 parts by weight of the highly crosslinked polyester polyol and 15 parts by weight of the hydrophilic polyether polyol into the reactor for mixing, control the temperature at 80-100℃, and stir for 30-60 minutes to obtain a polyol mixture.

[0076] Step 2: Cool down to 70-80℃, add 20 parts by weight of polyisocyanate, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0077] Step 3: Add 10 parts by weight of a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0078] Step 4: After surface modification treatment of 4 parts by mass of nano-silica, 0.6 parts by mass of nano-calcium carbonate and 0.8 parts by mass of carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0079] Step 5: Add 1.5 parts by weight of anti-aging agent, 0.8 parts by weight of antistatic agent, 0.8 parts by weight of ultraviolet absorber and 4 parts by weight of multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0080] Step 6: Slowly add ethyl acetate to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a scraper to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0081] Comparative Example 1:

[0082] The preparation method of the polyurethane film in this comparative example includes the following steps:

[0083] Step 1: Vacuum dehydrate the highly crosslinked polyester polyol at 100-110℃ for 2-3 hours; then add 20 parts by mass of the highly crosslinked polyester polyol and 25 parts by mass of the hydrophilic polyether polyol into the reactor for mixing, control the temperature at 80-100℃, and stir for 30-60 minutes to obtain a polyol mixture.

[0084] Step 2: Cool down to 70-80℃, add 25 parts by mass of polyisocyanate, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0085] Step 3: Add 12 parts by weight of a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0086] Step 4: After surface modification treatment of 4 parts by mass of nano-silica, 0.8 parts by mass of nano-calcium carbonate and 0.6 parts by mass of carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0087] Step 5: Add 1.5 parts by weight of anti-aging agent, 0.8 parts by weight of antistatic agent, 0.8 parts by weight of ultraviolet absorber and 4 parts by weight of multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0088] Step 6: Slowly add solvent to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a doctor blade to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0089] Comparative Example 2:

[0090] The preparation method of the polyurethane film in this comparative example includes the following steps:

[0091] Step 1: Vacuum dehydrate the highly cross-linked polyester polyol at 100-110℃ for 2-3 hours; then add 40 parts by weight of the highly cross-linked polyester polyol and 20 parts by weight of the hydrophilic polyether polyol into the reactor for mixing, control the temperature at 80-100℃, and stir for 30-60 minutes to obtain a polyol mixture.

[0092] Step 2: Cool down to 70-80℃, add 15 parts by mass of polyisocyanate, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0093] Step 3: Add 8 parts by weight of a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0094] Step 4: After surface modification treatment of 4 parts by mass of nano-silica, 0.6 parts by mass of nano-calcium carbonate and 0.9 parts by mass of carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0095] Step 5: Add 1.5 parts by weight of anti-aging agent, 0.6 parts by weight of antistatic agent, 0.6 parts by weight of ultraviolet absorber and 4 parts by weight of multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0096] Step 6: Slowly add ethyl acetate to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a scraper to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0097] Comparative Example 3:

[0098] The preparation method of the polyurethane film in this comparative example includes the following steps:

[0099] Step 1: Vacuum dehydrate the highly crosslinked polyester polyol at 100-110℃ for 2-3 hours; then add 35 parts by weight of the highly crosslinked polyester polyol and 12 parts by weight of the hydrophilic polyether polyol into the reactor for mixing, control the temperature at 80-100℃, and stir for 30-60 minutes to obtain a polyol mixture.

[0100] Step 2: Cool down to 70-80℃, add 23 parts by mass of polyisocyanate, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0101] Step 3: Add 10 parts by weight of a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0102] Step 4: After surface modification treatment of 4 parts by mass of nano-silica, 0.6 parts by mass of nano-calcium carbonate and 0.8 parts by mass of carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0103] Step 5: Add 1.5 parts by weight of anti-aging agent, 0.8 parts by weight of antistatic agent, 0.8 parts by weight of ultraviolet absorber and 4 parts by weight of multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0104] Step 6: Slowly add ethyl acetate to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a scraper to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0105] Comparative Example 4:

[0106] The preparation method of the polyurethane film in this comparative example includes the following steps:

[0107] Step 1: Vacuum dehydrate the highly crosslinked polyester polyol at 100-110℃ for 2-3 hours; then add 30 parts by weight of the highly crosslinked polyester polyol and 30 parts by weight of the hydrophilic polyether polyol into the reactor for mixing, control the temperature at 80-100℃, and stir for 30-60 minutes to obtain a polyol mixture.

[0108] Step 2: Cool down to 70-80℃, add 15 parts by mass of polyisocyanate, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0109] Step 3: Add 8 parts by weight of a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0110] Step 4: After surface modification treatment of 4 parts by mass of nano-silica, 0.6 parts by mass of nano-calcium carbonate and 0.9 parts by mass of carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0111] Step 5: Add 1.5 parts by weight of anti-aging agent, 0.6 parts by weight of antistatic agent, 0.6 parts by weight of ultraviolet absorber and 4 parts by weight of multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0112] Step 6: Slowly add ethyl acetate to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a scraper to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0113] Comparative Example 5:

[0114] The preparation method of the polyurethane film in this comparative example includes the following steps:

[0115] Step 1: Vacuum dehydrate the highly crosslinked polyester polyol at 100-110℃ for 2-3 hours; then add 35 parts by weight of the highly crosslinked polyester polyol and 25 parts by weight of the hydrophilic polyether polyol into the reactor for mixing, control the temperature at 80-100℃, and stir for 30-60 minutes to obtain a polyol mixture.

[0116] Step 2: Cool down to 70-80℃, add 12 parts by mass of polyisocyanate, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0117] Step 3: Add 8 parts by weight of a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0118] Step 4: After surface modification treatment of 4 parts by mass of nano-silica, 0.6 parts by mass of nano-calcium carbonate and 0.9 parts by mass of carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0119] Step 5: Add 1.5 parts by weight of anti-aging agent, 0.6 parts by weight of antistatic agent, 0.6 parts by weight of ultraviolet absorber and 4 parts by weight of multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0120] Step 6: Slowly add ethyl acetate to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a scraper to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0121] Comparative Example 6:

[0122] The preparation method of the polyurethane film in this comparative example includes the following steps:

[0123] Step 1: Vacuum dehydrate the highly crosslinked polyester polyol at 100-110℃ for 2-3 hours; then add 25 parts by mass of the highly crosslinked polyester polyol and 20 parts by mass of the hydrophilic polyether polyol into the reactor for mixing, control the temperature at 80-100℃, and stir for 30-60 minutes to obtain a polyol mixture.

[0124] Step 2: Cool down to 70-80℃, add 28 parts by mass of polyisocyanate, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0125] Step 3: Add 12 parts by weight of a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0126] Step 4: After surface modification treatment of 4 parts by mass of nano-silica, 0.8 parts by mass of nano-calcium carbonate and 0.6 parts by mass of carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0127] Step 5: Add 1.5 parts by weight of anti-aging agent, 0.8 parts by weight of antistatic agent, 0.8 parts by weight of ultraviolet absorber and 4 parts by weight of multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0128] Step 6: Slowly add solvent to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a doctor blade to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0129] Comparative Example 7:

[0130] The preparation method of the polyurethane film in this comparative example includes the following steps:

[0131] Step 1: Vacuum dehydrate the highly crosslinked polyester polyol at 100-110℃ for 2-3 hours; then add 35 parts by weight of the highly crosslinked polyester polyol and 25 parts by weight of the hydrophilic polyether polyol into the reactor for mixing, control the temperature at 80-100℃, and stir for 30-60 minutes to obtain a polyol mixture.

[0132] Step 2: Cool down to 70-80℃, add 15 parts by mass of polyisocyanate, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0133] Step 3: Add 6 parts by weight of a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0134] Step 4: After surface modification treatment of 4 parts by mass of nano-silica, 0.6 parts by mass of nano-calcium carbonate and 0.9 parts by mass of carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0135] Step 5: Add 1.5 parts by weight of anti-aging agent, 0.6 parts by weight of antistatic agent, 0.6 parts by weight of ultraviolet absorber and 4 parts by weight of multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0136] Step 6: Slowly add ethyl acetate to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a scraper to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0137] Comparative Example 8:

[0138] The preparation method of the polyurethane film in this comparative example includes the following steps:

[0139] Step 1: Vacuum dehydrate the highly crosslinked polyester polyol at 100-110℃ for 2-3 hours; then add 25 parts by mass of the highly crosslinked polyester polyol and 20 parts by mass of the hydrophilic polyether polyol into the reactor for mixing, control the temperature at 80-100℃, and stir for 30-60 minutes to obtain a polyol mixture.

[0140] Step 2: Cool down to 70-80℃, add 25 parts by mass of polyisocyanate, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0141] Step 3: Add 15 parts by weight of a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0142] Step 4: After surface modification treatment of 4 parts by mass of nano-silica, 0.8 parts by mass of nano-calcium carbonate and 0.6 parts by mass of carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0143] Step 5: Add 1.5 parts by weight of anti-aging agent, 0.8 parts by weight of antistatic agent, 0.8 parts by weight of ultraviolet absorber and 4 parts by weight of multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0144] Step 6: Slowly add solvent to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a doctor blade to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0145] Comparative Example 9:

[0146] The preparation method of the polyurethane film in this comparative example includes the following steps:

[0147] Step 1: Vacuum dehydrate the highly cross-linked polyester polyol at 100-110℃ for 2-3 hours; then add 30 parts by weight of the highly cross-linked polyester polyol and 20 parts by weight of the hydrophilic polyether polyol into the reactor for mixing, control the temperature at 80-100℃, and stir for 30-60 minutes to obtain a polyol mixture.

[0148] Step 2: Cool down to 70-80℃, add 20 parts by weight of polyisocyanate, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0149] Step 3: Add 10 parts by weight of a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0150] Step 4: After surface modification treatment of 2 parts by mass of nano-silica, 0.8 parts by mass of nano-calcium carbonate and 0.8 parts by mass of carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0151] Step 5: Add 1.5 parts by weight of anti-aging agent, 0.8 parts by weight of antistatic agent, 0.8 parts by weight of ultraviolet absorber and 4 parts by weight of multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0152] Step 6: Slowly add ethyl acetate to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a scraper to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0153] Comparative Example 10:

[0154] The preparation method of the polyurethane film in this comparative example includes the following steps:

[0155] Step 1: Vacuum dehydrate the highly cross-linked polyester polyol at 100-110℃ for 2-3 hours; then add 30 parts by weight of the highly cross-linked polyester polyol and 20 parts by weight of the hydrophilic polyether polyol into the reactor for mixing, control the temperature at 80-100℃, and stir for 30-60 minutes to obtain a polyol mixture.

[0156] Step 2: Cool down to 70-80℃, add 20 parts by weight of polyisocyanate, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃.

[0157] Step 3: Add 10 parts by weight of a special hydrophilic chain extender and continue the reaction for 1.5-2.5 hours;

[0158] Step 4: After surface modification treatment of 6 parts by mass of nano-silica, 0.8 parts by mass of nano-calcium carbonate and 0.8 parts by mass of carbon nanotubes, add them to the system and stir at high speed for 1-2 hours.

[0159] Step 5: Add 1.5 parts by weight of anti-aging agent, 0.8 parts by weight of antistatic agent, 0.8 parts by weight of ultraviolet absorber and 4 parts by weight of multifunctional high-efficiency crosslinking agent in sequence, and stir evenly;

[0160] Step 6: Slowly add ethyl acetate to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a scraper to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

[0161] Comparative Example 11:

[0162] The formulation uses a common polyurethane resin, and the raw materials, by weight percentage, include 45% polyester polyol, 25% diisocyanate, 8% small molecule diol chain extender, 5% polyethylene glycol, 3% micron-sized calcium carbonate, 2% monofunctional crosslinking agent, and the balance being DMF. The specific steps include the following:

[0163] Step 1: Diisocyanate and polyester polyol are added to a reaction vessel in proportion to carry out a prepolymer reaction to form a prepolymer. After the prepolymer is formed, small molecule diol chain extender, polyethylene glycol, micron-sized calcium carbonate and monofunctional crosslinking agent are added to obtain a non-uniform mixture.

[0164] Step 2: Slowly add DMF to the mixture and coat it onto the release surface of the release film. Use a doctor blade to coat it into a thin film. Dry the obtained film in an oven at 90-100℃ to obtain the polyurethane film.

[0165] The polyurethane films obtained in Examples 1 to 4 and Comparative Examples 1 to 11 were tested for moisture permeability, hydrostatic pressure, elongation at break and tensile strength. The results are shown in Table 1.

[0166] Table 1. Performance test results of polyurethane films in each group of examples and comparative examples.

[0167]

[0168]

[0169] As shown in Table 1, the comprehensive technical indicators of the polyurethane films obtained in Examples 1 to 4, such as moisture permeability, hydrostatic pressure, and tensile strength, are significantly better than those in Comparative Examples 1 to 11. In particular, the polyurethane formulation system formed by using highly cross-linked polyester polyols, hydrophilic polyether polyols, polyisocyanates, nano-silica, nano-calcium carbonate, and carbon nanotubes results in polyurethane films with high water pressure waterproofing and high moisture permeability that are far superior to the ordinary polyurethane resin film in Comparative Example 11.

[0170] In addition, as shown in Table 1, the test results of the polyurethane films in each embodiment and comparative example indicate that the formulation ratio of the polyurethane system is crucial to the high water pressure waterproof performance, high moisture permeability, and tensile strength of the film. Specifically, when there is an excess of highly cross-linked polyester polyol in Comparative Example 2, a deficiency of hydrophilic polyether polyol in Comparative Example 3, an excess of polyisocyanate in Comparative Example 6, and a deficiency of hydrophilic chain extender in Comparative Example 7, the moisture permeability of the polyurethane film will decrease. When there is a deficiency of highly cross-linked polyester polyol in Comparative Example 1, a deficiency or excess of hydrophilic polyether polyol in Comparative Examples 3 and 4, a deficiency of polyisocyanate in Comparative Example 5, a deficiency or excess of hydrophilic chain extender in Comparative Examples 7 and 8, and a deficiency or excess of nano-silica in Comparative Examples 9 and 10, the high water pressure waterproof performance of the film will be affected. The amount of polyisocyanate and hydrophilic chain extender in Comparative Examples 5 to 8 also has a significant impact on the elongation at break and tensile strength of the film.

[0171] In summary, by using a polyurethane formulation system consisting of highly cross-linked polyester polyols, hydrophilic polyether polyols, polyisocyanates, nano-silica, nano-calcium carbonate, and carbon nanotubes, and with a reasonable ratio of each component, the resulting polyurethane film can achieve a moisture permeability of over 12000 g / m²·24h, a hydrostatic pressure of over 35000 mmH₂O, an elongation at break of over 350%, and a tensile strength of over 6 MPa.

[0172] The polyurethane films obtained in Examples 1 to 4 were respectively laminated to a base fabric, wherein the base fabric was either a woven fabric or a knitted weft-knitted fabric. The woven fabric was a 75D all-polyester non-ammonia elastic striped fabric, using 75D / 72F high-elastic DTY polyester filaments as warp and weft yarns, with a plain weave structure, a thickness of 0.166mm, a weight of 76g / m², a warp density of 120 threads / 10cm, and a weft density of 92 threads / 10cm. The knitted weft-knitted fabric was a plain weave fabric, using high-elastic DTY polyester filaments as knitting yarns, with a thickness of 0.236mm, a transverse density of 42 stitches / inch, and a longitudinal density of 56 rows / inch. The resulting fabrics were tested for moisture permeability, hydrostatic pressure, and air permeability. The results are as follows:

[0173] Table 2. Fabric performance test results in each group of examples and comparative examples.

[0174]

[0175] As shown in Table 2, the fabric obtained by combining the polyurethane film of the present invention with the base fabric has a moisture permeability of more than 12,000 g / m2·24h before and after washing, and a hydrostatic pressure of up to 15,000 mmH2O, which can meet the fabric usage requirements of different windbreakers.

[0176] The above description is merely an optional embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-water-pressure, high-moisture-permeable polyurethane film, characterized in that, By weight percentage, it is prepared from the following raw materials: 25-35% highly crosslinked polyester polyol, 15-25% hydrophilic polyether polyol, 15-25% polyisocyanate, 3-5% nano silica, 0.5-1.0% nano calcium carbonate, 0.5-1.0% carbon nanotubes, 8-12% dimethylolpropionic acid, 1-2% anti-aging agent, 0.5-1% antistatic agent, 0.5-1% ultraviolet absorber, 3-5% multifunctional high-efficiency crosslinking agent, and the balance being solvent; The highly crosslinked polyester polyol is prepared by polycondensation reaction of pyromellitic dianhydride, glycerol and ethylene glycol, with its multifunctional monomers accounting for 20-30% of the total monomer mass. The hydrophilic polyether polyol is obtained by block copolymerization of polyethylene glycol and propylene oxide, with polyethylene glycol segments accounting for 30-50% of the total mass of the hydrophilic polyether polyol; The polyisocyanate is an aromatic isocyanate containing three or more isocyanate groups; The multifunctional high-efficiency crosslinking agent is a aziridine crosslinking agent.

2. The high water pressure and high moisture permeability polyurethane film according to claim 1, characterized in that, The solvent is selected from ethyl acetate and methyl acetal.

3. A method for preparing a high water pressure, high moisture permeability polyurethane film as described in any one of claims 1-2, characterized in that, Includes the following steps: Step 1: Dehydrate the highly cross-linked polyester polyol under vacuum at 100-110℃ for 2-3 hours; then add the highly cross-linked polyester polyol and the hydrophilic polyether polyol into the reactor in proportion and mix them. Control the temperature at 80-100℃ and stir for 30-60 minutes to obtain a polyol mixture. Step 2: Cool down to 70-80℃, add polyisocyanate in proportion, and react for 3-4 hours under nitrogen protection, with the reaction temperature controlled at 85-95℃. Step 3: Add dimethylolpropionic acid and continue the reaction for 1.5-2.5 hours; Step 4: After surface modification treatment of nano-silica, nano-calcium carbonate and carbon nanotubes, add them to the system and stir at high speed for 1-2 hours. Step 5: Add the anti-aging agent, antistatic agent, ultraviolet absorber and multifunctional high-efficiency crosslinking agent in sequence, and stir evenly; Step 6: Slowly add solvent to adjust the viscosity of the system, stir for 1-1.5 hours, filter and pour onto release paper, use a doctor blade to scrape a film onto the surface of the release paper, and then dry it in an oven at 90-100℃ to obtain the polyurethane film.

4. A fabric, characterized in that, It includes a fabric body and a polyurethane film as described in any one of claims 1-2, which is attached to one side surface of the fabric body.

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