JPH055949B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing a fabric that simultaneously has the dual functions of waterproofness and moisture permeability, and has excellent cold resistance properties. (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. In these dry or wet coating processes, polyurethane elastomer is generally preferably used as the coating resin in terms of film strength, rubber elasticity, and flexibility. However, in the case of breathable waterproof fabric made from polyurethane elastomer, it is made based on the balance between waterproof performance and moisture permeability, so the waterproof performance is 1500 mm or more (under the water column) as measured by JIS L-1096 water pressure resistance. For fabrics, humidity is 4000-5000g/ ^m2・24hrs (JIS Z-
0208 measurement), and furthermore, when used in extremely cold areas with temperatures below -20℃, the fabric becomes extremely hard, the film suffers from significant bending fatigue, and its waterproof properties decrease. It had the disadvantage of The present inventors have found that using polyurethane elastomer, the level of moisture permeability, which is one of the disadvantages of conventional moisture permeable waterproof fabrics, has been greatly improved, and the humidity inside the clothes can be smoothly controlled due to sweating during work or exercise in the rain. 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 highly moisture-permeable waterproof fabric by a wet coating method. However, when the moisture-permeable waterproof fabric obtained by this method is used in extremely cold regions, it hardens significantly at low temperatures and deteriorates in waterproofness due to bending fatigue, similar to the conventional moisture-permeable waterproof fabric made from polyurethane elastomer. had major drawbacks. (Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned current situation, and has a well-balanced waterproof property and moisture permeability, and has moisture permeability with good cold resistance properties in extremely cold regions. The purpose is to obtain a waterproof fabric. (Means and effects for solving the problem) As a result of intensive research, the present inventors discovered that there is a correlation between cold resistance characteristics and the ratio of absorbance at a specific wavelength of an infrared absorption spectrum, and based on this knowledge, As a result of further investigation, the present invention was arrived at. In other words, the present invention is based on ``the ratio of absorbance at wave numbers 3290 cm <sup>-1</sup> and 2950 cm <sup>-1</sup> in the infrared absorption spectrum.
A film made of a polyamino acid urethane resin having a molecular weight ranging from 0.4 to 2.0, which has microcells interconnected by pores in the thickness direction of the film, and micropores communicating with the microcells on the surface of the film. It has a porous membrane with countless numbers on one side of the water-repellent fiber fabric, and has a moisture permeability of 7000g/ <sup>m2</sup>・24hrs or more and a water pressure resistance.
``A moisture-permeable waterproof fabric with excellent cold resistance characterized by a length of 2000 mm or more'' and ``a polyamino acid urethane resin whose ratio of absorbance at wave numbers 3290 cm <sup>-1</sup> and 2950 cm <sup>-1</sup> in the infrared absorption spectrum is in the range of 0.4 to 2.0. A transparent material with excellent cold resistance characterized by applying a resin solution consisting of an isocyanate compound, a micropore-forming agent, and a polar organic solvent to one side of a fiber fabric, then immersing it in water, washing with hot water, and drying the fabric to make it water repellent. The gist of this paper is ``Method for manufacturing wet waterproof fabric.''
The present invention will be explained in detail below. The infrared series spectrum in the present invention is obtained using an infrared spectrophotometer.
When wavelengths are separated from the near-infrared region to the far-infrared region using a prism, etc., and the separated light is applied to a material, many relatively narrow absorption bands will appear due to the molecules that make up the material. It is useful for the identification of compounds, especially for the qualitative and quantitative analysis of functional groups, and is mainly used for the qualitative and quantitative analysis of organic substances. Polyamino acid urethane resin (hereinafter referred to as PAU)
It's called resin. ) is a copolymer of amino acids and urethane, and the present inventors have found that the copolymer composition greatly affects the physical properties of the film, such as temperature characteristics, hand feel, strength and elongation characteristics, and moisture permeability. First, the copolymerization ratio of amino acids and urethane is
As is clear from Figure 1, which shows the infrared absorption spectrum of PAU resin, 3290cm ^-1 (A) is attributed to the stretching vibration of the NH group, and 2950cm -1 (A) is attributed to the CH asymmetric stretching vibration used for the film thickness correction band ^. This is possible by determining the absorbance ratio of ¹ (B). Therefore, the composition ratio (weight fraction) of amino acids and urethane is 10.
~90: Various PAU resins of 90 to 10 were synthesized and their infrared absorption spectra were taken, and the above 3290 cm ^-1 and 2950
The ratio of absorbance in cm ^-1 was determined. Then these PAUs
Regarding moisture-permeable waterproof fabric coated with resin -30℃~
When the texture of the fabric was evaluated in a temperature range of +20°C, a correlation was found between the above absorbance ratio and cold resistance properties. That is, if the absorbance ratio is less than 0.4, the cold resistance will be poor and the texture will be noticeably hardened. On the other hand, if the absorbance ratio exceeds 0.2, the amino acid ratio will be high and the film will have excellent cold resistance and moisture permeability, but the film will have a hard texture due to low elongation and poor elastic recovery, and will also have poor adhesion to the base fabric. It also gets worse. Therefore, it is necessary to use a PAU resin having an absorbance ratio in the range of 0.4 to 2.0 in terms of cold resistance and film properties. Next, the same tendency as the cold resistance property was observed for heat resistance, and the above absorbance ratio was 0.4 to 2.0.
Unlike polyurethane elastomers, PAU resins in the range of
It does not cause a decrease in moisture permeability. Further, in the case of conventional polyurethane elastomers, transfer printing has been impossible due to problems of heat curing and decreased moisture permeability, but transfer printing is also possible with the moisture permeable waterproof fabric of the present invention. in this way
The reason why PAU resin exhibits good thermal behavior even at low and high temperatures is thought to be due to the α-helical structure of poly-α-amino acids. In other words, it is presumed that in the α-helical structure, α-amino acids form intramolecular hydrogen bonds, making the rod-shaped molecules thermally stable. The PAU resin used in the present invention is a copolymer consisting of amino acids and polyurethane, and the amino acids include DL-alanine, L-aspartic acid, L-
-cystine, L-glutamic acid, glycine, L-
These include lysine, L-methionine, L-leucine and their derivatives, and when synthesizing polyamino acids, the amino acid N-carboxylic anhydride (hereinafter referred to as N-carboxylic anhydride) is obtained from amino acids and phosgene.
It's called NCA. ) is commonly used. Polyurethane uses aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates singly or in mixtures thereof as isocyanate components, such as tolylene 2,4-diisocyanate,
4,4'-diphenylmethane diisocyanate,
Examples include 1,6-hexane diisocyanate and 1,4-cyclohexane diisocyanate.
Moreover, polyether polyol and polyester polyol are used as the polyol component.
Polyether polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc., and polyester polyols include reaction products of diols such as ethylene glycol and propylene glycol with dibasic acids such as adipic acid and sebacic acid; Examples include ring-opening polymers such as caprolactone. In addition, ethylenediamine, diethylamine, triethylamine, ethanolamine, etc. are used as the amines used in the copolymerization of amino acids and polyurethane. In this way, PAU resin can be used for various amino acids.
It is obtained by adding amines to the reaction system of NCA and a urethane prepolymer having an isocyanate group at the end. As the amino acid component constituting the PAU resin, optically active γ-alkyl-glutamate-NCA is preferably used from the viewpoint of film performance, and among the optically active γ-alkyl-glutamates, γ-methyl-NCA is preferably used from the viewpoint of price and film properties.
L-glutamate-NCA or γ-methyl-D-
Glutamate is often advantageously selected as the amino acid component of PAU resins. 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. As such a resin composition, a reaction product of an optically active γ-alkyl-glutamate-NCA and a urethane prepolymer among PAU resins is preferably used, but this is because the above-mentioned reaction product is a solvent system mainly composed of a polar organic solvent. For example, in a mixed solvent system of dimethylformamide and dioxane, the weight ratio of amino acid and urethane can be a uniform resin solution over a wide range of 90:10 to 10:90. This is because the ratio can be freely selected. The reason why high water pressure resistance and high moisture permeability can be obtained through wet coating processing of PAU resin is not obvious, but when observing the cross section of the film of the resulting moisture-permeable waterproof fabric, it is clear that PAU resin In the case of a film, the microcells are small, many in number, and uniformly distributed, which is thought to be a factor in providing high moisture permeability and high water pressure resistance. Furthermore, PAU resin's own high affinity for water vapor may be one of the driving forces behind its high moisture permeability. Considering the molecular structure of the PAU resin used in the present invention, it is found that the PAU resin is composed of a block copolymer of amino acids and urethane, and as mentioned above, the amino acid component mainly forms an α-helical structure. The urethane component forms a random coil structure. This is due to the attribution of the amide band in the infrared absorption spectrum (amide V615 cm ^-1 ; poly-
This has been confirmed by the key band of the α-helical conformation of γ-alkyl-L-glutamate. 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. Taken together, it is highly conceivable that PAU resin has two structures, an α-helical structure and a random coil structure, and has a looser packing structure at the interface between the two. It is thought that the loose packing state of this molecular structure and the hydrogen bonds between amide bonds give the polymer its own high water vapor permeability, unlike that of polyurethane elastomers. In the present invention, a moisture-permeable waterproof fabric with good cold resistance properties is obtained by applying the above-mentioned PAU resin to a fabric. Combined use of compounds.
In the present invention, an isocyanate compound is also used. The isocyanate compound is 2,4-tolylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, hexamethylene isocyanate, or 3 moles of these diisocyanates and 1 mole of a compound containing active hydrogen (e.g. trimethylolpropane, glycerin, etc.). Triisocyanates obtained by addition reactions 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. can also be used, and should be used appropriately depending on workability, purpose, etc. The amount of isocyanate compound used is 0.1 to PAU resin.
It is desirable to use it in a proportion of 10%, preferably 0.5-5%. If the amount used is less than 0.1%, the adhesion of the resin to the fabric will be poor, and if it exceeds 10%, the texture will be hardened, which is not preferable. Next, in the PAU resin film, a micropore-forming agent is used in combination to reduce the size of the microcells and to ensure that a large number of pores exist uniformly on the surface. Examples of the micropore-forming agent used here include anionic surfactants, nonionic surfactants, hydrophilic polymers, and polyurethane elastomers. The amount used is 0.5 to 10% for anionic surfactants and nonionic surfactants, 0.3 to 20% for hydrophilic polymers, and 1.5 to 1.5% for polyurethane elastomers based on the solid content of the PAU resin used in combination. It is desirable to be in the range of 30%. 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. Moreover, when the amount exceeds the above range, the pores become too large and high water pressure resistance 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. In addition, nonionic surfactants include polyoxyethylene alkyl ether, polyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene fatty acid amide ether, polyhydric alcohol fatty acid ester, polyoxyethylene polyhydric alcohol fatty acid ester, It refers to fatty acid sucrose ester, alkyrodamide, etc., or any mixture thereof. Hydrophilic polymers include holivinylpyrrolidone, polyacrylic acid, polyacrylic ester, carboxyvinyl polymer organic amine, and polyethyleneimine, and are substances that can be dissolved, dispersed, or emulsified in polar organic solvents and soluble in water. This refers to polymers that can be used. Polyurethane elastomer is a polymer obtained by reacting polyisocyanate and polyol, and known aliphatic and aromatic polyisocyanates can be used as the polyisocyanate.
Examples include hexamethylene diisocyanate, triene diisocyanate, xylene diisocyanate, and reaction products of excess thereof with polyhydric alcohols. As the polyol, known polyethers, polyesters, and other polyols used in the production of ordinary polyurethane resins can be used. Examples of polyesters include polyhydric alcohols such as ethylene glycol, diethylene glycol or 1,4-butanediol, and adipic acid;
Examples include reactants of polybasic carboxylic acids such as oxalic acid or sebacic acid. Examples of polyether include polyhydric alcohols such as ethylene glycol and propylene glycol to which one or more alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide are added. In the present invention, the above-mentioned PAU resin, isocyanate compound, micropore forming agent, and polar organic solvent are used in combination, and the polar organic solvent used here includes dimethylformamide, dimethylacetamide,
Examples include N-methylpyrrolidone and hexamethylenephosphonamide. 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 the water, and the resin coagulates in the water. A resin coagulation method using such a method is generally called a wet coagulation method. When a 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 having countless micropores can be obtained. A resin solution consisting of a PAU resin, an isocyanate compound, a micropore-forming agent, and a polar organic solvent may 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 polyamide synthetic fibers such as nylon 6 and nylon 66, polyester synthetic fibers such as polyethylene terephthalate, polyacrylonitrile synthetic fibers, polyvinyl alcohol synthetic fibers, and even triacetate. Examples include woven fabrics, knitted fabrics, nonwoven fabrics, etc. made of semi-synthetic fibers or mixed fibers such as nylon 6/cotton, polyethylene terephthalate/cotton, etc. In the present invention, processing is performed using these fiber fabrics treated with a water repellent agent. The water repellency of the fabric
It is desirable that the water repellency is 90 or higher as determined by the JIS L-1096 spray method. The water repellent used may be a known one such as a paraffin water repellent, a polysiloxane water repellent, or a fluorine water repellent, and the treatment may be carried out by a commonly known method. If particularly good water repellency is required, use a fluorine-based water repellent, such as Asahi Guard 730 manufactured by Asahi Glass Co., Ltd.
This may be carried out by padding (fluorine-based water repellent emulsion) with a 5% aqueous solution (squeezing ratio: 35%), followed by heat treatment at 160° C. for 1 minute. After applying the above-mentioned resin solution to the fiber fabric, the fabric is immersed in water, at a water temperature of 0 to 30°C.
It is desirable that the water temperature be within the range of 30°C, as dimethylformamide will diffuse into the water faster and the micropores in the resin film will become larger.
As a result, the water pressure resistance may become poor. Also,
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 solidifying 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. In the above-mentioned method, a water-repellent treated fabric was used as the fiber fabric, but in the present invention, the water-repellent treatment is performed again after coating. Regarding the water repellent agent and water repellent treatment method used here, the padding method, the padding method,
Water repellent treatment may be performed by a spray method, a coating method, or the like. Furthermore, in order to increase the durability of water repellency, water repellent treatment can be performed using a resin such as melamine resin in combination. In the method of the present invention, by performing the water repellent treatment both before and after coating compounding, a product with better water pressure resistance can be obtained than when only one of the treatments is performed. 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 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 abrasion 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.
For the purpose of preventing treatment spots, it may be applied as a solution of chlorinated hydrocarbons such as 1.1.1.-trichloroethane, trichlorethylene, perchlorethylene, etc., or solvents such as toluene, hexane, mineral turpentine, etc. 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. (Example) Next, the present invention will be further explained with reference to Examples.
Performance measurements and evaluations in this example were performed in the following manner. (1) Water resistance JIS L-1096 (low water pressure method) (2) Water repellency JIS L-1096 (spray method) (3) Moisture permeability JIS Z-0208 (4) Infrared absorption spectrum Composition ratio of specified amino acid and urethane becomes more
PAU resin was diluted with dimethylformamide to an appropriate concentration and cast onto a glass plate.
Dry at 50-80°C to form a film with a thickness of 3-5μ. Attributed to asymmetric CH stretching vibration
Since the absorbance at 2950 cm ^-1 is proportional to the film thickness, this absorption band at 2950 cm ^-1 is used as a thickness correction band. Regarding absorption strength, see drawing 2.
The BC of a specific absorption band is calculated using the baseline method shown in the figure.
AC is read and the absorbance D is determined by the following formula: D=log ₁₀ AC/BC In the present invention, the absorbance ratio=D ₃₂₉₀ /D ₂₉₅₀ is determined. (5) Cold resistance characteristics Change in texture due to temperature The change in texture due to temperature was investigated in an atmosphere of -30℃ and +20℃, and the texture was changed from 10 in flexibility to 1 in stiffness.
Evaluate based on 10 ranks. Waterproofness evaluation by rubbing during cold resistance: 100% by hand for samples left at -30℃ for 2 hours.
After rolling, measure the water pressure resistance and compare it with the water pressure resistance at 20℃. Example 1 First, the PAU resin (polyamino acid urethane resin) used in this example was manufactured by the following method. Polytetramethylene glycol (OH value 56.9)
110g of 985g and 222g of isophorone diisocyanate
Urethane prepolymer with isocyanate groups at the end (NCO equivalent weight 1233) after reacting at ℃ for 5 hours
I got it. 51 g of this urethane prepolymer and 119 g of γ-methyl-L-glutamate-NCA were dissolved in 669 g of a mixed solvent of dimethylformamide/dioxane (weight ratio = 7/3), and while stirring, 102 g of a 2% hydrous hydrazine solution was added thereto at 30°C. When the reaction was carried out for 3 hours, an emulsion-like PAU resin solution with a viscosity of 23,000 cps (25°C) and good fluidity was obtained. (PAU resin (A)) This PAU resin (A) is used in formulation 1 described below. Next, the resulting PAU resin solution was cast onto a glass plate and dried at 70°C to increase the film thickness.
A transparent film of 5μ was obtained. The infrared absorption spectrum of this film was taken, and the wavenumbers were 3290 cm ^-1 and 2950 cm -1.
The ratio of absorbance in cm ^-1 was found to be 1.90. Here, the warp yarn is made of nylon 70 denier/24 filaments, the weft yarn is made of nylon 70 denier/34 filament, and the warp yarn density is 120 pieces/inch, and the weft yarn density is
Prepare 90 strands/inch of plain fabric (taffeta) after refining and dyeing with acid dye, and apply fluorine yarn water repellent emulsion Asahi Guard 710 (product of Asahi Glass Co., Ltd.) to this with a 5% aqueous solution. (squeezing ratio 35%), followed by heat treatment at 160℃ for 1 minute, and then using a calendar processing machine with mirror rolls at a temperature of 170℃, a pressure of 30Kg/cm, and a speed of 20℃.
Calendering was carried out under conditions of m/min. Next, a resin solution shown in Formulation 1 below was applied using a knife-over roll coater at a coating amount of 60 g/m ² , and then immersed in a 20°C water bath for 30 seconds to solidify the resin, and then heated to 50°C. Washed in warm water for 10 minutes, dried, and then treated with an aqueous solution of 5% Asahi Guard AG-710 (fluorine-based water repellent emulsion, product of Asahi Glass Co., Ltd.) and 10% isopropyl alcohol as a water repellent treatment process. After drying, the material was padded (squeezing ratio: 35%), and then heat treated at 160°C for 1 minute. The coated fabric of the present invention using the obtained PAU resin (A) was designated as Fabric A. Formulation 1 PAU resin (A) 100 parts Burnock BL-50 (isocyanate compound, Dainippon Ink & Chemicals Co., Ltd. product) 2 parts CRISVON AW-7H (micropore forming agent; polyurethane elastomer, Dainippon Ink & Chemicals Co., Ltd. product) 8 parts 10 parts of dimethylamide Next, in order to further clarify the effects of the present invention, PAU resins (B) to (D) described below were used instead of PAU resin (A) in the coating solution of Formulation 1, and the isocyanate compound Fabrics B to D were obtained in the same manner as in Formulation 1, using the same compositions of the micropore forming agent and dimethylformamide. Fabric B is a moisture permeable waterproof fabric according to the present invention, and Fabric C and Fabric D are comparative examples thereof. [Production of PAU resin (B)] 111 g of the urethane prepolymer (NCO equivalent: 1233) used in Example 1 and 59 g of γ-methyl-L-glutamate-NCA were mixed with dimethylformamide/
Dioxa (weight ratio = 7/3) was dissolved in 666 g of a mixed solvent, and while stirring, 51 g of a 2% hydrous hydrazine solution was added to it and the reaction was carried out at 30°C for 2 hours, resulting in an emulsion with a viscosity of 32000 cps (25°C) PAU with good flowability
A resin solution was obtained. (PAU resin (B)) Calculating the ratio of absorbance at wave numbers 3290 cm ^-1 and 2950 cm ^-1 from the infrared absorption spectrum of this PAU resin (B)
It was 0.61. [Production of PAU resin (C)] 153 g of the urethane prepolymer (NCO equivalent: 1233) used in Example 1 and 17 g of γ-methyl-L-glutamate-NCA were mixed with dimethylformamide/
Dissolved in 666 g of mixed solvent of dioxa (weight ratio = 7/3), added 13 g of 2% hydrazine solution while stirring, and reacted at 30°C for 5 hours, resulting in a translucent PAU resin with good fluidity. A solution was obtained.
(PAU resin (C)) Calculating the ratio of absorbance at wave numbers 3290 cm ^-1 and 2950 cm ^-1 from the infrared absorption spectrum of this PAU resin (C)
0.2, the resin composition was flexible, but had a urethane-like texture and was tough. [Production of PAU resin (D)] 25.5 g of the urethane prepolymer (NCO equivalent: 1233) used in Example 1 and 144.5 g of γ-methyl-glutamate-NCA were mixed with dimethylformamide/
666g mixed solvent of dioxane (weight ratio = 7/3)
120 g of a 2% aqueous hydrazine solution was added to the solution while stirring, and the reaction was carried out at 30°C for 3 hours to obtain a yellowish brown emulsion resin solution with good fluidity and a viscosity of 18,000 cps (25°C). (PAU resin (D)) Calculating the ratio of absorbance at wave numbers 3290 cm ^-1 and 2950 cm ^-1 from the infrared absorption spectrum of this PAU resin (D)
2.3, the composition was rigid and brittle and exhibited low elongation. The performance of four moisture-permeable waterproof fabrics (fabrics A to D) made of PAU resins (A) to (D) was measured and evaluated, and the results are shown in Table 1.

[Table] As is clear from Table 1, both Fabric A and Fabric B according to the present invention exhibit excellent moisture permeability and water pressure resistance, and furthermore, their texture does not change even under extreme environmental changes with a temperature difference of 50°C. It was found that there was no change in water pressure resistance after bending, and that it could be used satisfactorily even in extremely cold conditions. On the other hand, in the case of comparative fabric C, the fabric had a urethane feel and was resistant to changes in water pressure and temperature after bending, and was only comparable to conventional urethane coated products. Also,
In the case of comparative fabric D, the texture and physical properties were similar to that of polyα-amino acids, and the initial performance of moisture permeability and water pressure resistance was good, but the texture was stiff and the elongation was low. The film was damaged by bending, and when the film surface was observed after being rubbed 100 times by hand, it was found that the film had peeled off from the base fabric surface. (Effect of the invention) The present invention provides wave numbers in an infrared absorption spectrum.
A PAU resin with an absorbance ratio of 3290 cm ^-1 and 2950 cm ^-1 in the range of 0.4 to 2.0 is used, and the fabric obtained according to the present invention has good cold resistance properties and has little texture hardening at low temperatures. Unlike conventional moisture-permeable waterproof fabrics, it is possible to obtain moisture-permeable waterproof fabrics that can be used satisfactorily even in cold regions. The moisture-permeable waterproof fabric of the present invention is a material that is well suited not only for sports clothing but also for survival use in extremely cold regions.

[Brief explanation of the drawing]

FIG. 1 shows the infrared absorption spectrum of the PAU resin (polyamino acid urethane resin) used in the present invention, and FIG. 2 is a diagram showing the absorption intensity at a specific wave number (cm ^-1 ) determined by the baseline method. (A)... Wave number 3290cm ^-1 NH stretching vibration band, (B)...
...wave number 2950cm ^-1 film thickness correction band CH asymmetrical stretching vibration band, XY...baseline, A...
The intersection of the perpendicular line passing through B and the baseline XY, B...
...The wave number (cm ^-1 ) of position B where the spectrum transmittance is the lowest (absorption position), C...The position where the transmittance of the perpendicular line passing through B is 0%.

Claims (1)

[Claims] 1. Wave number 3290 cm ^-1 in infrared absorption spectrum
A coating made of ^a polyamino acid urethane resin with a ratio of absorbance of A porous membrane having countless micropores that communicate with the microcells,
Water repellent fiber fabric on one side, moisture permeability 7000
A moisture-permeable waterproof fabric with excellent cold resistance, characterized by a water pressure resistance of 2000 mm or more at g/m ² 24 hours or more. 2 Wave number 3290cm ^-1 in infrared absorption spectrum
A resin solution consisting of a polyamino acid urethane resin, an isocyanate compound, a micropore-forming agent ^, and a polar organic solvent with a ratio of absorbance at A method for producing a moisture-permeable waterproof fabric with excellent cold resistance, characterized by comprising a resin film forming step of washing with hot water and drying, and a water repellent step of treating the fiber fabric with water repellency.