Waterproof and breathable composite fabric and preparation process thereof

Abstract

The application relates to the technical field of waterproof and breathable film research and development, and discloses a waterproof and breathable composite fabric and a preparation process thereof. The product structure of the fabric is as follows: polyester high-elasticity twill fabric is used as the fabric, hot-melt web glue is used as the middle layer, and polyurethane waterproof and moisture-permeable film is used as the lining; the fabric, the middle layer and the lining are subjected to laminating and compounding treatment on a pressing machine to obtain the waterproof and breathable composite fabric; the polyurethane waterproof and moisture-permeable film comprises an isocyanate prepolymer component and a polyol component; long-chain linear or cage-type siloxane monomers with chemically introduced hydroxyl alkyl groups are contained in the isocyanate prepolymer component; a solvent-free two-component reaction coating and curing process is adopted to prepare the polyurethane film with excellent waterproof performance. The waterproof performance of the polyurethane film product prepared by the application can meet the commercial use requirements.

Description

Technical Field

[0001] This invention relates to the field of waterproof and breathable membrane research and development technology, and in particular to a waterproof and breathable composite fabric and its preparation process. Background Technology

[0002] Waterproof and breathable fabrics made from waterproof and breathable materials can prevent water molecules from penetrating the fabric under certain pressure, while allowing sweat to be conducted to the outside as water vapor, maintaining the comfort and dryness of the fabric. They belong to a high-level functional fabric category. Based on processing methods, waterproof and breathable materials mainly include three types: high-density fabrics, coated fabrics, and laminated fabrics. Laminated fabrics, which combine the excellent properties of other fabrics, are gaining an increasing market share. Their preparation method generally involves bonding a waterproof and breathable functional membrane and a base fabric using hot melt adhesive or other adhesives under appropriate hot-pressing temperatures, pressures, and hot roller bonding speeds.

[0003] Waterproof and breathable membranes can be divided into fluorinated membranes and fluorine-free membranes. Due to the bioaccumulation and durability of fluorides, polyurethane dense membranes have received much attention in recent years as the mainstream fluorine-free waterproof and breathable membranes on the market. However, because polyurethane molecular chains usually contain hydrophilic groups (such as ether bonds, urethane groups, etc.), unmodified polyurethane nanofiber membranes, due to their inherent hydrophilicity, lack effective hydrophobic channels and are usually difficult to resist liquid water penetration.

[0004] This invention cites the following references:

[0005] The master's thesis of Chen Chang, published by Guangxi University in 2023, entitled "Preparation of cage-type silsesquioxane (POSS) and its application in coatings", disclosed the chemical structure and synthesis method of cage-type silsesquioxane (POSS) T8-NH2. Summary of the Invention

[0006] This invention introduces hydrophobic alkyl long-chain and siloxane components into a polyurethane system, and prepares a polyurethane waterproof and breathable membrane through a reactive hot melt coating process. This membrane is then laminated with fabric to obtain a waterproof and breathable composite fabric, which has high market value in the field of waterproof and breathable materials.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A polyurethane waterproof and breathable membrane, wherein the membrane raw material comprises an isocyanate prepolymer component and a polyol component;

[0009] The formulation of the isocyanate prepolymer component is as follows: 10 parts by weight of terminal hydroxyl alkyl long-chain siloxane monomer, 10 parts by weight of polyethylene glycol, 20-30 parts by weight of polypropylene glycol, and 50-60 parts by weight of 4,4-diphenylmethane diisocyanate.

[0010] The end-hydroxyl alkyl long-chain siloxane monomer is one or a combination of end-hydroxyl alkyl long-chain linear siloxane monomer and end-hydroxyl alkyl long-chain cage siloxane monomer.

[0011] The polyol component is formulated as follows: 70 parts by weight of polyethylene glycol, 30 parts by weight of polytetrahydrofuran diol, 3-4 parts by weight of 1,4-butanediol, 0.1-1.5 parts by weight of a leveling agent, and 0.05-0.5 parts by weight of a wetting agent.

[0012] Preferably, the relative molecular weight of the polyethylene glycol is 2000, the relative molecular weight of the polypropylene glycol is 2000, and the relative molecular weight of the polytetrahydrofuran diol is 2000.

[0013] A preparation process of a polyurethane waterproof and moisture-permeable film, comprising the following steps:

[0014] Step one: end-hydroxyl alkyl long-chain siloxane monomer, polyethylene glycol, and polypropylene glycol are added to a reactor, nitrogen is introduced for dehydration at 85-95°C until the water content is reduced to below 0.05%, then 4,4-diphenyl methane diisocyanate is added, the temperature is raised to 70-80°C, and the reaction is stirred at 200-400 rpm / min, the isocyanate content is monitored until it is 3.5%-4.0%, then the reaction is stopped by cooling, and an isocyanate prepolymer component is prepared;

[0015] Step two: the polyol component is formulated according to the formulation, and stirred at 800-900 rpm / min until it is uniformly mixed, and a polyol component is prepared;

[0016] Step three: the isocyanate prepolymer component and the polyol component are mixed according to an isocyanate index of 1.03-1.08, specifically: the polyol component and a catalyst are first stirred at 800-900 rpm / min for 4-6 min, then the isocyanate prepolymer component is added and stirred until it is uniformly mixed, then it is knife-coated on a release film with a thickness of 0.2-0.3 mm, and cured at a temperature of 100-120°C for 1-5 min, and a polyurethane waterproof and moisture-permeable film is prepared.

[0017] Preferably, the catalyst used in step three is 1,3,5-tris(dimethylamine propyl)-1,3,5-hexahydrotriazine, and the amount of the catalyst used is 0.7-1.0 parts by weight.

[0018] A waterproof and breathable composite fabric, the product structure of the fabric is as follows: a polyester high-elasticity twill fabric as the fabric, a hot melt web adhesive as the intermediate layer, and a polyurethane waterproof and moisture-permeable film as the lining.

[0019] Preferably, the hot melt web adhesive is W120 type copolyamide Co-PA hot melt web adhesive or A024 type thermoplastic polyurethane hot melt web adhesive.

[0020] The application discloses a preparation process of a waterproof and breathable composite fabric, which comprises the following steps: laminating and compounding a fabric, an intermediate layer and a lining on a pressing machine to obtain the waterproof and breathable composite fabric; wherein the process parameters of the laminating and compounding are as follows: the temperature is 120-150 DEG C, the pressure is 0.3-0.5 kPa, and the hot-pressing and compounding time is 10-40 s.

[0021] Preferably, the waterproof and breathable composite fabric is used as raw material for manufacturing waterproof and moisture-permeable clothes.

[0022] The application has the following advantages:

[0023] By molecular design, the undecyl group, benzene ring and linear siloxane or cage siloxane structure are integrated into one molecular structure, and a hydroxyl-terminated alkyl long-chain linear or cage siloxane monomer is synthesized.

[0024] By chemically introducing the hydroxyl-terminated alkyl long-chain linear or cage siloxane monomer into a polyurethane matrix, a polyurethane film with excellent waterproof and moisture-permeable performance is prepared by using a solvent-free two-component reaction coating and curing process, and experimental results prove that the water resistance of the film product can meet the commercial use requirements. DETAILED DESCRIPTION

[0025] Experimental example one:

[0026] The synthesis mechanism of the hydroxyl-terminated alkyl long-chain linear siloxane monomer is as follows:

[0027] 1 mol equivalent of tetramethyl divinyl disiloxane and 2 mol equivalents of dimethyl phenyl silane are subjected to a silicon hydrogen addition reaction to obtain a terminal phenyl siloxane monomer;

[0028] 1 mol equivalent of the terminal phenyl siloxane monomer and 2 mol equivalents of undecenol are subjected to a Friedel-Crafts alkylation reaction to obtain a terminal hydroxyl-alkyl long-chain linear siloxane monomer;

[0029] The specific experimental steps for preparing the terminal hydroxyl-alkyl long-chain linear siloxane monomer are as follows:

[0030] 1.9 g of tetramethyl divinyl disiloxane is added into 20 mL of toluene and uniformly mixed, 2.8 g of dimethyl phenyl silane and 1 drop of chloroplatinic acid isopropanol solution are added under the condition of nitrogen and room temperature, after uniform mixing, stirring reaction is conducted for 3 h, toluene is distilled out under reduced pressure, and then washing and drying are conducted to obtain the terminal phenyl siloxane monomer;

[0031] 4.6 g of the terminal phenyl siloxane monomer and 3.4 g of undecenol are added into 50 mL of dichloromethane, stirring is continuously conducted, the reaction temperature is controlled at 25 DEG C, 0.3 g of anhydrous aluminum chloride is added, after reaction for 1 h, dichloromethane is distilled out, and then washing and drying are conducted to obtain the terminal hydroxyl-alkyl long-chain linear siloxane monomer;

[0032] The chemical structural formula of the end-hydroxyl alkyl long-chainization linear siloxane monomer is:

[0033] ;

[0034] The hydrogen spectrum characterization result of the end-hydroxyl alkyl long-chainization linear siloxane monomer is:

[0035] 1 H NMR (400MHz, DMSO-D6, δ, ppm): 0.06 (s, 12H), 0.27 (s, 12H), 0.74-0.78 (t, 4H), 1.05-1.09 (t, 4H), 1.25-1.35 (m, 28H), 1.52-1.64 (m, 8H), 2.61-2.66 (m, 6H), 3.54-3.58 (m, 4H), 6.96-6.98 (d, 4H), 7.44-7.46 (d, 4H).

[0036] Experimental Example Two:

[0037] The synthesis mechanism of the end-hydroxyl alkyl long-chainization cage siloxane monomer is:

[0038] 1 mole equivalent of cage silsesquioxane (POSS) T8-NH2 reacts with 2 mole equivalents of phenyl methacrylate by amine-ene addition reaction to obtain an end-phenyl cage siloxane monomer;

[0039] 1 mole equivalent of the end-phenyl cage siloxane monomer reacts with 2 mole equivalents of undecenol by Friedel-Crafts alkylation reaction to obtain an end-hydroxyl alkyl long-chainization cage siloxane monomer;

[0040] The specific experimental steps for preparing the end-hydroxyl alkyl long-chainization cage siloxane monomer are:

[0041] 5.8 g of cage silsesquioxane (POSS) T8-NH2 is added to 100 mL of dry dichloromethane, stirred and mixed uniformly, then 3.3 g of phenyl methacrylate is added, the temperature is controlled not to exceed 30°C, stirring is carried out under normal pressure, and the reaction is carried out for 8 h. After the reaction is completed, dichloromethane is evaporated, washed, and dried to obtain an end-phenyl cage siloxane monomer;

[0042] 9 g of the end-phenyl cage siloxane monomer is added to 100 mL of dichloroethane, stirred and mixed uniformly, then 3.4 g of undecenol is added, stirring is carried out for 30 min, then 0.4 g of anhydrous aluminum chloride is added, the temperature is increased to 55°C, and the reaction is carried out for 6 h. After the reaction is completed, the temperature is cooled to room temperature, dichloroethane is evaporated, washed, and dried to obtain an end-hydroxyl alkyl long-chainization cage siloxane monomer;

[0043] The chemical structural formula of the end-hydroxyl alkyl long-chain caged siloxane monomer is as follows:

[0044] ;

[0045] The hydrogen spectrum characterization result of the end-hydroxyl alkyl long-chain caged siloxane monomer is as follows:

[0046] 1 H NMR (400MHz, DMSO-D6, δ, ppm): 0.05-0.06 (d, 21H), 0.58-0.71 (m, 2H), 1.18-1.71 (m, 44H), 2.48-2.74 (m, 8H), 2.86-3.00 (m, 4H), 3.45-3.58 (m, 4H), 4.27-4.31 (t, 2H), 7.02 (s, 8H).

[0047] Example One:

[0048] A polyurethane waterproof and moisture-permeable film is prepared, and the raw material formula of the polyurethane waterproof and moisture-permeable film is as follows:

[0049]

[0050] Note: The catalyst used when mixing the isocyanate prepolymer component and the polyol component in Table 1 is 1,3,5-tris(dimethylaminopropyl)-1,3,5-hexahydrotriazine, and the amount of the catalyst is 0.8 parts by weight;

[0051] The preparation process of the polyurethane waterproof and moisture-permeable film includes the following steps:

[0052] Step one: The end-hydroxyl alkyl long-chain siloxane monomer, polyethylene glycol and polypropylene glycol are added to a reactor, and nitrogen is introduced for dehydration at 90°C until the water content is reduced to below 0.05%, then 4,4-diphenyl methane diisocyanate is added, the temperature is raised to 80°C, and the reaction is stirred at 300 rpm for 5 minutes. When the isocyanate content is monitored to be 3.5%-4.0%, the reaction is stopped by cooling, and an isocyanate prepolymer component is prepared;

[0053] Step two: The polyol component is prepared according to the polyol component formula, and is stirred at 850 rpm for 5 minutes to mix uniformly, and a polyol component is prepared;

[0054] Step three: The isocyanate prepolymer component and the polyol component are mixed according to an isocyanate index of 1.05, specifically as follows: the polyol component and the catalyst are stirred at 850 rpm for 5 minutes, then the isocyanate prepolymer component is added and stirred uniformly, and is coated on a release film with a coating thickness of 0.25 mm, and is cured at 110°C for 3 minutes to prepare a polyurethane waterproof and moisture-permeable film;

[0055]

[0056] Hydrostatic pressure resistance of polyurethane waterproof and moisture permeable film: according to the standard of GB / T 4744-2013 "Determination and evaluation of waterproof performance of textiles - Hydrostatic pressure method", the hydrostatic pressure resistance value of the product is tested, the test area is 100 cm 2 , and the pressure increasing rate is 600 mmH2O / min:

[0057]

[0058] Note: The comparative example uses polyethylene glycol (Mn=2000) and polypropylene glycol (Mn=2000) to replace the end hydroxyl alkyl long-chain siloxane monomer in the polyurethane waterproof and moisture permeable film according to equal mass, to prepare an unmodified polyurethane waterproof and moisture permeable film.

[0059] Example two:

[0060] The preparation process of the waterproof and breathable composite fabric is as follows: the polyester high-elasticity twill fabric (thickness of 0.29 mm, density of (47 x 42 roots / (10 cm), yarn fineness of 8.3 tex, 2 / 2 twill) is used as the fabric, the hot melt web adhesive (W120 type co-polyamide Co-PA, melting point of 115-130°C, grammage of 12 g / m 2 ) is used as the intermediate layer, and the polyurethane waterproof and moisture permeable film is used as the lining, and then the lamination and composite treatment is carried out on the pressing machine, the treatment temperature is 130°C, the pressure is 0.3 kPa, the hot pressing composite is 20 s, and the waterproof and breathable composite fabric is obtained.

[0061]

[0062] Note: The moisture permeation amount in Table 4 is tested by the inverted cup method, the test parameters are as follows: the diameter of the circular test cup is 127 mm, the relative humidity is 50%, the temperature is 23°C, distilled water is added to the moisture permeation cup, the distance from the sample is 20 mm, the height of the water is 5 mm, and the grid distance from the sample is 6 mm.

Claims

1. A polyurethane waterproof and breathable membrane, characterized in that, The membrane raw material includes an isocyanate prepolymer component and a polyol component; The formulation of the isocyanate prepolymer component is as follows: 10 parts by weight of terminal hydroxyl alkyl long-chain siloxane monomer, 10 parts by weight of polyethylene glycol, 20-30 parts by weight of polypropylene glycol, and 50-60 parts by weight of 4,4-diphenylmethane diisocyanate. The hydroxyl-terminated alkyl long-chain siloxane monomer is one or a combination of hydroxyl-terminated alkyl long-chain linear siloxane monomer and hydroxyl-terminated alkyl long-chain cage-type siloxane monomer. The chemical structural formula of the hydroxyl-terminated alkyl long-chain linear siloxane monomer is as follows: ； The chemical structural formula of the hydroxyl-terminated alkyl long-chain cage-like siloxane monomer is as follows: ； The polyol component is formulated as follows: 70 parts by weight of polyethylene glycol, 30 parts by weight of polytetrahydrofuran glycol, 3-4 parts by weight of 1,4-butanediol, 0.1-1.5 parts by weight of leveling agent, and 0.05-0.5 parts by weight of wetting agent.

2. The polyurethane waterproof and breathable membrane according to claim 1, characterized in that, The relative molecular weights of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran glycol are all 2000.

3. The polyurethane waterproof and breathable membrane according to claim 1, characterized in that, The preparation process of polyurethane waterproof and breathable membrane includes the following steps: Step 1: Add hydroxyl-terminated alkyl long-chain siloxane monomers, polyethylene glycol, and polypropylene glycol to a reactor. Dehydrate the mixture by passing nitrogen gas through it at 85-95°C until the water content drops below 0.05%. Then add 4,4-diphenylmethane diisocyanate, heat to 70-80°C, and stir the reaction at 200-400 rpm. When the isocyanate content reaches 3.5%-4.0%, cool down and stop the reaction to obtain the isocyanate prepolymer component. Step 2: Prepare the ingredients according to the polyol component formula, and stir and mix them evenly at 800-900 rpm to obtain the polyol component; Step 3: Add the isocyanate prepolymer component and polyol component according to the isocyanate index of 1.03-1.08, as follows: First, stir the polyol component and catalyst at 800-900 rpm for 4-6 minutes, then add the isocyanate prepolymer component and stir evenly. Coat the mixture onto the release film with a coating thickness of 0.2-0.3 mm, and cure it at 100-120℃ for 1-5 minutes to obtain a polyurethane waterproof and breathable membrane.

4. The polyurethane waterproof and breathable membrane according to claim 3, characterized in that, The catalyst used in step three is 1,3,5-tris(dimethylaminopropyl)-1,3,5-hexahydrotriazine, and the amount of the catalyst used is 0.7-1.0 parts by weight.

5. The polyurethane waterproof and breathable membrane according to claim 1, characterized in that, The preparation method of hydroxyl-terminated alkyl long-chain linear siloxane monomers is as follows: One molar equivalent of tetramethyldivinyldisiloxane reacts with two molar equivalents of dimethylphenylsilane in a hydrosilylation reaction to yield a terminal phenylsiloxane monomer. One molar equivalent of a terminal phenylsiloxane monomer undergoes a Friedel-Crafts alkylation reaction with two molar equivalents of undecenol to yield a terminal hydroxyl alkylated long-chain linear siloxane monomer.

6. The polyurethane waterproof and breathable membrane according to claim 1, characterized in that, The preparation method of hydroxyl-terminated alkyl long-chain cage-like siloxane monomers is as follows: One molar equivalent of caged silsesquioxane T8-NH2 reacts with two molar equivalents of phenyl methacrylate in an aminoenyl addition reaction to give a phenyl-terminated caged siloxane monomer. One molar equivalent of a phenyl-terminated caged siloxane monomer is reacted with two molar equivalents of undecenol via Friedel-Crafts alkylation to yield a hydroxyl-terminated alkylated long-chain caged siloxane monomer.

7. A waterproof and breathable composite fabric, characterized in that, The product structure of the waterproof and breathable composite fabric is as follows: polyester high-elastic twill fabric as the outer fabric, hot melt adhesive as the middle layer, and polyurethane waterproof and breathable membrane as described in any one of claims 1-6 as the inner fabric.

8. The waterproof and breathable composite fabric according to claim 7, characterized in that, The hot melt adhesive is either W120 type copolyamide Co-PA hot melt adhesive or A024 type thermoplastic polyurethane hot melt adhesive.

9. The waterproof and breathable composite fabric according to claim 7, characterized in that, The manufacturing process of waterproof and breathable composite fabric is as follows: the fabric, intermediate layer and lining are laminated on a heat press to obtain waterproof and breathable composite fabric; the process parameters of the lamination process are: temperature 120-150℃, pressure 0.3-0.5kPa, and hot pressing time 10-40s.

10. A waterproof and breathable composite fabric according to claim 7, characterized in that, The waterproof and breathable composite fabric is used as a raw material for manufacturing waterproof and breathable clothing.

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