JPH0585671B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a method for producing a highly durable, moisture-permeable waterproof fabric having excellent water pressure resistance. (Prior art) Generally, moisture permeability and waterproofness are contradictory functions, but waterproof fabrics with excellent moisture permeability have a continuous property that allows water vapor to escape from the coating resin film during dry or wet coating processing. It is obtained by forming countless microscopic pores. Generally, polyurethane elastomer is preferably used as a coating resin during these dry or wet coating processes in terms of film strength, rubber elasticity, and flexibility. Because it is made based on a balance between the two, the waterproof performance is 4000 to 5000g/ ^m2・24hrs (JIS Z- 0208 measurement)
The current situation is that only a certain amount can be obtained. The inventors of the present invention have greatly improved the level of moisture permeability of conventional polyurethane elastomer-based moisture-permeable waterproof fabrics, making it possible to smoothly control the humidity inside the clothes due to sweating when working in the rain or exercising. A method for producing a moisture permeable waterproof fabric was previously proposed in Japanese Patent Application No. 10853/1983. That is, this method uses a polyamino acid urethane resin and a special micropore-forming agent to control the microcells and pore diameter of a porous membrane to produce a waterproof fabric with high moisture permeability using a wet coating method. However, although the polyamino acid urethane resin produced by this method is suitable for obtaining highly moisture permeable waterproof fabrics, detergents used during home washing or dry cleaning may remain, and contaminants may adhere when worn. It had the disadvantage of reduced water pressure resistance. (Problems to be Solved by the Invention) The present invention was made in view of the above-mentioned current situation, and an object thereof is to obtain a highly moisture-permeable waterproof fabric having excellent durability and water pressure resistance. It is something. (Means and operations for solving the problems) The present invention achieves the above-mentioned objects and has the following configuration. In other words, the present invention involves a first step of applying a resin solution consisting of a polyamino acid resin, a polyurethane resin, an isocyanate compound, and a polar organic solvent to a fiber fabric, and then immersing it in water, washing it in hot water, and drying it. A moisture-permeable waterproof fabric characterized by comprising a second step of applying a resin solution consisting of an amino acid urethane resin, an isocyanate compound, a micropore-forming agent, and a polar organic solvent, followed by immersion in water, hot water washing, and drying. The gist of this paper is ``Method for manufacturing ``. The present invention will be explained in detail below. In the present invention, first, a first step is performed in which a resin solution consisting of a polyamino acid resin, a polyurethane resin, an isocyanate compound, and a polar organic solvent is applied to a fiber fabric, and then the fabric is immersed in water, washed with hot water, and dried. The polyamino acid resin used in the present invention is mainly composed of synthetic polyamino acids, and the amino acids include DL-alanine, L-aspartic acid, and L-
Examples include cystine, L-glutamic acid, glycine, L-lysine, L-methionine, L-leucine and derivatives thereof. When synthesizing polyamino acids, amino acid N obtained from amino acids and phosgene
-Carboxylic acid anhydride (hereinafter, N-carboxylic acid anhydride is referred to as NCA) is generally used. As the isocyanate component of the polyurethane resin used in the present invention, aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates are used singly or in mixtures thereof, such as tolylene 2,4-diisocyanate, 4,4'-diphenylmethane diisocyanate, etc. , 1,6-hexane diisocyanate, 1,4-cyclohexane diisocyanate, and the like. As the polyol component, polyether polyols and polyester polyols are used. Polyether polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc., and polyester polyols are produced by the reaction of diols such as ethylene glycol and propylene glycol with dibasic acids such as adipic acid and sebacic acid. and ring-opening polymers such as caprolactone and caprolactone. In the method of the present invention, polyester polyurethane is preferably used as the polyurethane having good mixing stability with polyamino acids. As the amino acid component constituting the above-mentioned polyamino acid resin, optically active γ-alkyl-glutamate-NCA is preferably used from the viewpoint of film performance, and γ-methyl-L is particularly preferred from the viewpoint of price and film properties.
-glutamate NCA or γ-methyl-D-glutamate is often advantageously selected. In order to obtain the porous membrane of the present invention, it is advantageous to use a uniform resin composition made of a water-soluble solvent system from the viewpoint of both coating properties and wet film forming properties. When blending polyamino acids and polyurethane, this can be achieved by preparing a solution in advance with a solvent that can dissolve both, and stirring the mixture while heating if necessary. Solvents that can dissolve both include dimethylformamide, dimethylacetamide, dimethylsulfoxide, dioxane, and these solvents, as well as chlorinated hydrocarbon compounds such as dichloroethane, chloroform, methylene chloride, and dichloroacetic acid, and chlorinated strong oxides. Among them, a solvent mainly composed of a polar effective solvent, for example, a mixed solvent mainly composed of dimethylacetamide, is preferably used. The concentration of polymer suitable for blending is 5 to 50% by weight (hereinafter %
shall represent weight %), usually 10 to 30
A range of % is used. The weight ratio of polyamino acid and polyurethane used in the present invention can be varied over a wide range from 90:10 to 10:90, and may be appropriately selected depending on the required performance of the resin film. The above weight ratio is 50:50~20:80
Particularly preferred from the viewpoint of film performance.
Hereinafter, a resin obtained by mechanically mixing a polyamino acid and a polyurethane will be referred to as a blend resin. In the present invention, for the purpose of improving the peeling resistance between the above-mentioned blend resin, film, and fabric, a compound having high affinity with the fiber base fabric is used in combination. In the present invention, an isocyanate compound is also used as the compound. Examples of the isocyanate compound include 2,4-tolylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene isocyanate, or a compound containing 3 moles of these diisocyanates and active hydrogen (for example, trimethylolpropane, glycerin, etc.)
Triisocyanates obtained by addition reaction with 1 mol are used. The above-mentioned isocyanates may be in a form in which the isocyanate group is free, or in a form in which the blocks are stabilized by adding phenol, methyl ethyl ketoxime, etc., and the blocks are dissociated by subsequent heat treatment. It can be used and should be used appropriately depending on workability, purpose, etc. The amount of isocyanate compound used is based on the blend resin.
It is desirable to use it in a proportion of 0.1 to 10%, preferably 0.5 to 5%. If the amount used is less than 0.1%,
The adhesive strength of the resin to the fabric is poor, and conversely, if it exceeds 10%, the texture becomes hard, which is not preferable. In the present invention, the above-mentioned blend resin, isocyanate compound, and polar organic solvent are used in combination, and the polar organic solvents used here include dimethylformamide, dimethylacetamide, N-methylpyrrolidone, hexamethylenephosphonamide, etc. be. These substances are highly soluble in water, and when a polar organic solvent solution of a water-insoluble resin is immersed in water, only the polar organic solvent dissolves in water, and the resin solidifies in water. The resin coagulation method is generally called the wet coagulation method. When the resin is coagulated by a wet coagulation method, a trace amount of the polar organic solvent present in the resin is eluted into water, so a resin film having countless micropores can be obtained. Furthermore, when observing the coating surface of the blended resin of the coating fabric obtained in the first step of the method of the present invention, it was found that it had countless micropores with a diameter of 1μ or less, and that the coating surface was smoother than that of the polyamino acid urethane resin. It is believed that this contributes to good initial water pressure resistance, improved stain resistance, and reduced detergent residue, that is, to maintenance of water pressure resistance with excellent durability. The resin solution consisting of a polyamino acid resin, a polyurethane resin, an isocyanate compound, and a polar organic solvent can be applied to a fiber fabric by a conventional coating method. Generally, the coating thickness of the resin is 10 to 300 μm due to machine performance. The fiber fabrics mentioned here include polyamino acid synthetic fibers such as nylon 6 and nylon 66,
Woven and knitted fabrics made of polyester synthetic fibers such as polyethylene terephthalate, polyacrylonitrile synthetic fibers, polyvinyl alcohol synthetic fibers, semi-synthetic fibers such as triacetate, or blended fibers such as nylon 6/cotton and polyethylene terephthalate/cotton. , nonwoven fabrics, etc. After applying the above resin solution to the fiber fabric, the fabric is immersed in water at a temperature of 0 to 30°C.
It is desirable that the water temperature be in the range of 30°C or higher, and dimethylformamide will diffuse into the water faster and the micropores of the resin film will become larger, which may result in poor water pressure resistance. In addition, the dipping time must be at least 20 seconds; if it is less than 20 seconds, the resin will not solidify sufficiently and a satisfactory blended resin film will not be obtained. After coagulating the blended resin in water, the fabric is washed with hot water to remove any remaining solvent. The conditions for hot water washing vary depending on the mixing ratio of polyamino acid resin and polyurethane resin, but usually the temperature is 30 to 80°C.
You can do this for more than a minute. After washing with hot water, dry. The above is the first step in the method of the present invention. Next, in the present invention, as a second step, a resin solution consisting of a polyamino acid urethane resin, an isocyanate compound, a micropore forming agent, and a polar organic solvent is applied to the surface coated in the first step, and then immersed in water, Wash with hot water and dry. The polyamino acid urethane resin used here (hereinafter
It is called PAU resin. ) is a copolymer consisting of polyamino acids and polyurethane, and as an amino acid
Examples include DL-alanine, L-aspartic acid, L-cystine, L-glutamic acid, glycycin, L-lysine, L-methionine, L-leucine and their derivatives, and when synthesizing polyamino acids, they can be obtained from amino acids and phosgene. Amino acid N-carboxylic anhydride (hereinafter referred to as N-carboxylic anhydride)
It's called NCA. ) is commonly used. As the isocyanate component of polyurethane, aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates are used singly or in mixtures thereof, such as tolylene 2,4-diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,6- Hehexane diisocyanate, 1.
Examples include 4-cyclohexane diisocyanate. As the polyol component, polyether polyol and polyester polyol are used. Polyether polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. Polyester polyols include reactions between diols such as ethylene glycol and propylene glycol and dibasic acids such as adipic acid and sebacic acid. Examples include products and ring-opening polymers such as caprolactone. Examples of amines used in the copolymerization of amino acids and polyurethane include ethylenediamine, diethylamine, triethylamine, and ethanolamine. In this way, PAU resin can be used for various amino acids.
It is obtained by adding amines to the reaction between NCA and a urethane prepolymer having isocyanate groups at the ends. As the amino acid component constituting the above-mentioned PAU resin, optically active γ-alkyl-glutamate NCA is preferably used from the viewpoint of film performance, and γ-methyl-L-glutamate NCA or γ-methyl-glutamate NCA is particularly preferred from the viewpoint of price and film properties. D-glutamate is often advantageously selected. Examples of the micropore-forming agent used in the present invention include anionic surfactants, nonionic surfactants, and hydrophilic polymers. The amount used is preferably in the range of 0.1 to 10% for anionic surfactants and nonionic surfactants, and 0.05 to 5% for hydrophilic polymers, based on the PAU resin used in combination. If the amount of these micropore-forming agents used is less than the above range, the pores of the PAU resin film will become too small, making it difficult to obtain interconnected microcells and resulting in poor moisture permeability. Also,
When the amount exceeds the above range, the pores become too large and a water pressure resistance of 1500 mm or more cannot be obtained. The anionic surfactants used as the above-mentioned micropore-forming agents include conventionally known alkyl sulfate ester salts, alkylbenzene sulfonates, α-olefin sulfonates, alkyl sulfonates, fatty acid amide sulfonates, and dialkyl sulfosuccinic acids. Salt, etc. or any mixture thereof. Nonionic surfactants include polyoxyethylene alkyl ether, polyethylene alkyl phenyl ether, polyoxyethylene aliphatic ester, polyoxyethylene aliphatic amide ether, polyhydric alcohol aliphatic ester, and polyoxyethylene polyhydric alcohol fatty acid. It refers to esters, fatty acid sucrose esters, alkyrodamides, etc., or any mixture thereof. Hydrophilic polymers include polyvinylpyrrolidone, polyacrylic acid, polyacrylic ester, carboxyvinyl polymer organic amine, polyethyleneimine, etc., and are substances that can be dissolved, dispersed, or emulsified in polar organic solvents and soluble in water. It refers to a polymer that has a Regarding the isocyanate compound and polar organic solvent used together in this second step, please refer to the above-mentioned first step.
The same material used in the process can be used. In the second step of the present invention, after applying a resin solution consisting of the above-mentioned micropore-forming agent, PAU resin, isocyanate compound, and polar organic solvent, the fabric is immersed in water, at a water temperature of 0 to 30°C. It is desirable that the water temperature be within this range; if the water temperature is 30°C or higher, dimethylformamide will diffuse into the water faster and the fine pores in the resin film will become larger, which may result in poor water pressure resistance. In addition, the dipping time must be at least 10 seconds; if it is less than 10 seconds, the resin will not solidify sufficiently and a satisfactory PAU resin film will not be obtained. After coagulating the PAU resin in water, the fabric is washed with hot water to remove any remaining solvent. Conditions for hot water washing vary depending on the amounts of PAU resin and micropore forming agent used, but it may be carried out at a temperature of 30 to 80° C. for 3 minutes or more. After washing with hot water, dry. The fiber fabric used in the present invention may be a fabric that has been treated with water repellency, but this fiber fabric does not necessarily need to be treated with water repellency in advance, and the fabric obtained after coating may be treated with water repellency. Good too. Regarding the water repellent agent and water repellent treatment method used here, the padding method,
Water repellent treatment may be performed by a spray method, a coating method, or the like. Further, in order to improve the durability of water repellency, water repellent treatment can be performed using a resin such as melamine resin. In the method of the present invention, there is no problem even if the water repellent treatment is performed both before and after the coating process, and in this case, a product with even better water pressure resistance can be obtained. Further, in order to improve the smoothness and flexibility of the fabric, a polysiloxane resin may be further applied to the fabric. As the polysiloxane to be applied, dimethylpolysiloxane, phenyl group-containing polysiloxane, modified silicone oil such as amino-modified or olefin-modified silicone oil, methylhydrogen polysiloxane, or a mixture of dimethylpolysiloxane and methylhydrogen polysiloxane can be used. Although it may be selected as appropriate, dimethylpolysiloxane having a molecular weight of about 5,000 to 30,000 is preferably used in the present invention. This polysiloxane treatment first of all imparts smoothness to the fabric and can reduce frictional damage to the film due to friction between the fabrics. This smoothing effect also has the advantage of making it easy to put on and take off without using a lining. Second, the silicone resin adheres between the fabric structures and reduces the friction between the threads that make up the fabric, resulting in a softer texture. This polysiloxane treatment may be applied in the form of an aqueous dispersion, emulsion, etc., but for the purpose of preventing treatment spots, chlorinated hydrocarbons such as 1.1.1-trichloroethane, trichloroethylene, perchlorethylene, toluene, hexane, etc. It may also be applied as a solution in a solvent such as mineral turpentine. The polysiloxane resin may be applied by a commonly used padding method, coating method, spraying method, or the like. The amount of polysiloxane deposited is preferably 0.1% or more in terms of solid content based on the weight of the fiber. The present invention has the above configuration, but the reason why the moisture permeable waterproof fabric of the present invention has high water pressure resistance and high moisture permeability is not clear, but the obtained moisture permeable waterproof fabric When observing the cross section of the film formed in the first step, the cross section of the film formed in the first step has countless microcells with a diameter of 1 μm or less, and the cross section of the film formed in the second step has many microcells with a diameter of 1 to 5 μm. This is thought to be a factor in providing high moisture permeability and high water pressure resistance. Furthermore, the high affinity of polyamino acid resins and PAU resins themselves for water vapor may be one of the driving forces behind their high moisture permeability. Blend resin and PAU used in the present invention
Considering the molecular structure of the resin, the amino acid component mainly forms an α-helical structure, while the urethane component forms a random coil structure. This was confirmed by the assignment of the amide band in the infrared absorption spectrum (amide V615cm ^-1 , a key band of α-helical conformation of poly-γ-alkyl-L-glutamate) in the porous membrane produced by the wet coagulation method of the present invention. has been done. In general, in the case of amino acid resins, the driving force behind their high moisture permeability is their high diffusion coefficient, and this is thought to be due to the α-helical structure of the amino acid resins, which have large side chains. (Example) Next, the present invention will be further explained by examples.
The performance of the fabric in this example was measured and evaluated by the following method. (1) Water resistance According to JIS L-1996 (low water pressure method), the water pressure resistance of the sample was measured before and after the washing durability test in Section 5 below. (2) Water repellency JIS L-1096 (spray method) (3) Moisture permeability JIS Z-0208 (4) Washing durability test Repeat washing 10 times according to JIS L-0842 (A-2 method). Example 1 Blend resin A and blend resin B of polyamino acid and polyurethane, and PAU resin X used in this Example 1 and Examples 2 and 3 described later were manufactured by the following method. [Manufacture of blend resin A] Polytetramethylene adipate (molecular weight approximately 1000) having terminal hydroxyl groups and methylene bis-
4-Phenyl isocyanate was reacted at 100°C for 5 hours to obtain a urethane prepolymer of unterminated isocyanate, and this was chain-extended with butanediol. 180 parts of the polyurethane obtained was mixed with dimethylformamide.
Dissolve in 420 parts. On the other hand, polyglutamic acid-γ
- Dilute 400 parts of ethylene dichloride solution of methyl ester (solid content 20%, molecules approximately 250,000) with 400 parts of dimethylformamide. Next, under strong stirring,
180 parts of the above polyamino acid solution and 140 parts of the above polyurethane solution are mixed. Subsequently, ethylene chloride was distilled off under reduced pressure, and a dimethylformamide solution of a blend resin with a weight ratio of polyamino acid and polyurethane of 30:70 (solution viscosity at 25°C
Obtained 25000CPS248 copies. This will be referred to as blend resin A. This blend resin A is used in formulation 1 described below. [Production of Blend Resin B] In the production of Blend Resin A, the weight ratio of polyamino acid and polyurethane was adjusted in the same manner as in the production of Blend Resin A, except that 300 parts of the polyamino acid solution and 150 parts of the polyurethane solution were used. 300 parts of a dimethylformamide solution (solution viscosity at 25° C. of 23,000 CPS) of a blend resin having a ratio of 40:60 was obtained. This will be referred to as blend resin B. This blend resin B is used in Example 3, which will be described later. [Production of PAU resin X] Polytetramethylene glycol (OH value 56.9)
1,970 g of 1-6-hexamethylene diisocyanate and 504 g of 1-6-hexamethylene diisocyanate were reacted at 90°C for 5 hours to obtain a urethane prepolymer (NCO equivalent: 2340) having isocyanate groups at the ends. 85g of this urethane prepolymer and γ-methyl-L-glutamate
When 85g of NCA was dissolved in 666g of a mixed solvent of dimethylformamide/dioxane (weight ratio = 7/3), 50g of 2% triethylamine solution was added while stirring, and the reaction was carried out at 30℃ for 5 hours, resulting in a viscosity of 32000 CPS.
(25°C) A yellowish brown emulsion-like PAU resin solution with good fluidity and resin solid content concentration of 20% was obtained. this
Use PAU resin X. This PAU resin X is used in formulation 2 described below. A moisture permeable waterproof fabric of the present invention was produced using blend resin A and PAU resin X in the following manner. First, nylon was used as the base fabric for both warp and weft.
Warp density using 70 denier/48 filament
A plain woven fabric (taffeta) with a weft density of 120 threads/inch and a weft density of 90 threads/inch was prepared, and after scouring and dyeing with acid dyes in the usual manner, it was coated with Asahigart 710 (a fluorine-based water repellent emulsion). Asahi Glass Co., Ltd. product) Patching with 5% aqueous solution (squeezing ratio 35
%), and after drying, heat treatment was performed at 160°C for 1 minute. Next, calendering was performed using a calendering machine with a mirror roll at a temperature of 170°C, a pressure of 30 kg/cm, and a speed of 20 m/min, followed by a resin solution with a resin solid content concentration of 21% as shown in Formulation 1 below. Apply the coating amount using a knife-over roll coater
After coating at 10 g/m ² , the resin was immersed in a 15°C water bath for 40 seconds to solidify the resin. Then in warm water at 50℃
Washed for 10 minutes and dried. Prescription 1 Blend resin A 100 parts Crisbon BL-50 (isocyanate compound,
Dainippon Ink & Chemicals Co., Ltd. product) 1 part dimethylformamide 14 parts Next, apply 50 g of a resin solution with a resin solids concentration of 18% shown in the following recipe 2 to the resin-coated surface of the fabric using a knife-over-roll coater. /m ² and then immersed in a 15°C water bath for 20 seconds to solidify the resin, followed by washing in warm water at 50°C for 5 minutes and drying to obtain a moisture permeable waterproof fabric of the present invention. Prescription 2 PAU resin Forming agent>) 5 parts Dimethylformamide 14 parts For comparison with the present invention, a comparative sample was prepared in exactly the same manner as in this example except that PAU resin X was used in place of blend resin A in formulation 1 of this example. A moisture-permeable waterproof fabric was obtained. The performance of the obtained comparative moisture-permeable waterproof fabric and the moisture-permeable waterproof fabric of the present invention was measured, and the results are shown in Table 1.

[Table] As is clear from Table 1, the moisture-permeable waterproof fabric according to the present invention has good durability with water pressure resistance that far exceeds the practical limit of 1500 mm even after washing, and also has high moisture permeability. There were no problems with other performance. Example 2 In manufacturing the moisture-permeable waterproof fabric of Example 1 above, Example 1 was used, except that the amount of Crisbon Assista SD-11 (micropore forming agent) used in formulation 2 of the resin liquid used was 1 part. A moisture-permeable waterproof fabric of the present invention was produced in exactly the same manner as in Example 1. When the performance of the resulting fabric was measured, the water pressure resistance was 3600 degrees before washing.
mm, 2100mm after washing, shows good durability far exceeding the practical limit of 1500mm even after washing, and has high moisture permeability at 7920g/ ^m2・24hrs, and is water repellent. There were no problems at 100 degrees, and excellent performance was shown in all cases. Example 3 When producing the moisture permeable waterproof fabric of Example 1,
Example except that blend resin B was used in place of blend resin A in formulation 1 of the resin liquid used, and the amount of Crisbon Assister SD-11 (micropore forming agent) used in formulation 2 of the resin liquid used was 1 part. A moisture-permeable waterproof fabric of the present invention was produced in exactly the same manner as in Example 1. When the performance of the resulting fabric was measured, the water pressure resistance was 3500 mm before washing and 2100 mm after washing, and even after washing it far exceeded the practical limit of 1500 mm, showing good durability. It had high moisture permeability at 8030g/m ² /24hrs, and had no problems with water repellency at 100, showing excellent performance in both. (Effects of the Invention) The present invention provides wet coating using a blended resin liquid in which a polyamino acid resin and a polyurethane resin are mechanically mixed in a common solvent, and then a wet coating using a PAU resin liquid containing micropore formation. It has a structure in which coating is performed, and with this structure, it is possible to obtain a moisture-permeable waterproof fabric that has excellent durability and satisfies water pressure resistance. The moisture permeable waterproof fabric of the present invention is a material well suited for sports clothing due to its excellent performance.

Claims (1)

[Claims] 1. A first step in which a resin solution consisting of a polyamino acid resin, a polyurethane resin, an isocyanate compound, and a polar organic solvent is applied to a fiber fabric, and then immersed in water, washed with hot water, and dried, and a polyamino acid urethane resin is applied to the above-mentioned coated surface. , after applying a resin solution consisting of an isocyanate compound, a micropore forming agent and a polar organic solvent, immersing it in water and washing it with hot water,
A method for producing a moisture-permeable waterproof fabric, comprising a second step of drying.