JPS6360156B2 - - Google Patents

Description

[Detailed description of the invention]

This invention relates to a method for manufacturing a moisture-permeable waterproof fabric. The purpose is to propose a waterproof fabric that has both high moisture permeability and waterproofness, as well as excellent texture and durability, and a method for manufacturing the same. Various methods for producing moisture-permeable waterproof fabrics have been proposed. In many of these, pores are formed in an elastomer such as polyurethane using some method to impart moisture permeability, and water repellency is maintained through water repellent treatment. Various methods have been proposed for forming pores; for example, a blowing agent is included in the elastomer, the blowing agent is decomposed by heat treatment after coating, and gases such as carbon dioxide are released into the elastomer. A method of forming pores and a method of incorporating a perforating agent into an elastomer and extracting the perforating agent after coating to form pores are known. However, the pores formed in the elastomer by this method can be of various sizes, ranging from several microns to several tens of microns,
Otherwise, large pores may be formed, which may provide moisture permeability but lack waterproofness, causing practical problems such as water leakage. On the other hand, if the foaming agent decomposes and remains in the elastomer, or the perforating agent remains in the elastomer without being completely extracted, waterproofness may be improved, but sufficient moisture permeability may not be obtained, making it difficult to make clothes and wear them. It had the disadvantage of being stuffy. Another known method is to add a water repellent to the elastomer to form pores in order to increase its waterproofness, but this method lacks durability and the water repellent comes off when washed, reducing the waterproofness. It has decreased significantly. In the present invention, as a result of research on these points,
When a mixture of polyurethane and polyvinylidene fluoride is used and a solvent that substantially dissolves them is formed into a film, the fabric is coated with a liquid at a mixing ratio that allows phase separation of the polyurethane and polyvinylidene fluoride,
If heat treatment is applied after wet coagulation, long pores will be formed inside the fabric in a direction almost parallel to the surface of the fabric, and these pores will communicate with each other through communicating pores, and the film will have many fine pores on its surface. It has been found that by using a membrane, it is possible to create a moisture-permeable waterproof fabric that has good moisture permeability and also has excellent waterproof properties. The difference between the conventional moisture-permeable waterproof fabric and the moisture-permeable waterproof fabric of the present invention lies in the internal structure of the membrane, the fine pores on the surface, and the inclusion of a fluorine-based polymer. The foaming agent or perforating agent is mixed to form pores, and when the membrane is viewed in cross section after the foaming agent and perforating agent are removed, pores are circular or long in the perpendicular direction to the fabric. Most of the pores are independent pores with no communication between them. On the other hand, in the manufacturing method of the present invention, by coating the liquid at a mixing ratio that allows polyurethane and polyvinylidene fluoride to phase separate, and heat-treating it after wet coagulation, the inside of the membrane is formed into a long approximately inertia shape extending in a direction approximately parallel to the fabric surface. It has been found that the membrane can have a completely different internal structure from conventional membranes. Furthermore, it was found that the individual pores inside the membrane were not independent pores that communicated with each other through communicating pores that were opened here and there on the wall. When pores are formed by mixing conventional foaming agents or perforating agents with elastomers, the pores inevitably become large, with diameters ranging from several microns to several tens of microns or more, and such large pores have good moisture permeability, but are not waterproof. Lacks sex. On the other hand, if attempts are made to make the pores smaller, the foaming agent or perforating agent may be extracted poorly, making it difficult to form pores, and even if the waterproofness is good, the moisture permeability is likely to be lost. Conventional methods using blowing agents and perforating agents have had difficulty adjusting the pore diameter and have large variations in quality. On the other hand, the waterproof fabric of the present invention does not use a foaming agent or a perforating agent, and a large number of fine pores with a diameter of microns or less are formed between the surface layer of the membrane with a thickness of 3 to 5 microns. A film with a stable structure is obtained,
Furthermore, the fine pores of 5 microns or less formed on the clothing surface are connected to the internal pores, giving it good moisture permeability, and the surface pores are much smaller than water droplets, making it waterproof. It became a sufficient film. The physical characteristics of this membrane structure, especially the internal structure of the membrane, are different from conventional products, and the texture is very flexible, and the membrane has excellent durability when bent, and has better moisture permeability than conventional products. It turned out to be quite good. In manufacturing this waterproof fabric, in order to prevent the fiber gaps of the base fabric from being completely occluded, the base fabric is pretreated, for example, impregnated or coated with a polyurethane solution, and then polyurethane and polyfluoride are applied. The film of the present invention can be formed on the surface layer by coating a mixture of vinylidene and a solvent that dissolves vinylidene, wet coagulating it, and then heat-treating it at a temperature below the melting point of polyurethane and polyvinylidene fluoride. In this way, the fabric base fabric is pre-treated 3
By forming the layered structure, it is possible to increase the adhesive strength even when the adhesiveness between the surface layer coating mixture and the fabric is poor. In addition, if such a three-layer structure is used, the moisture permeability will decrease slightly, but the water resistance will be further improved, and if water repellent treatment is applied, a breathable waterproof fabric with even more complete waterproofness can be manufactured. . This three-layered moisture-permeable waterproof fabric is shown in FIG.
This waterproof fabric has a base polyurethane layer 2 on a fabric base material 3, and a polyurethane and polyvinylidene fluoride mixed layer 1 on top of that, and inside the base polyurethane layer 2, there is a long approximately coast-shaped layer in a direction almost parallel to the fabric 3 surface. Pores b are formed, and the pores communicate with each other through communication holes c opened in the wall thereof, and also communicate with holes a opened on the surface. When the sizes of pores a, pores b, and communicating pores c were measured for the membrane formed in Example 1, the pore diameter of pores a was 0.1 to 3 microns, and the pores of 1 micron or less were 3 million to 10 million pores/diameter. ^cm2 , 1~3
Micron is 1 million to 1.5 million pieces/cm ² , pore b is short diameter 2
~5 microns, the major diameter was 4 to 15 microns, and the diameter of the communicating hole c was 2 to 10 microns. In addition to the above-described structure, this moisture-permeable waterproof fabric is characterized by the fact that it contains a fluorine-based polymer. Conventional methods include adding a small amount of water repellent to elastomer to form a film in order to improve waterproofness, but this method has poor durability of waterproofing and does not become waterproof after washing. sex has significantly decreased. In the present invention, a fluorine-based polymer is mixed into polyurethane instead of a water repellent agent, which gives it high water repellency and maintains its waterproof properties even after washing. The shortcomings of are gone. In the present invention, polyurethane refers to polyurethane that exhibits phase separation when mixed with polyvinylidene fluoride to form a film, and by changing the mixing ratio of polyurethane and polyvinylidene fluoride within the range that exhibits this phase separation. , waterproofness, adhesion to fabric, and moisture permeability change. In other words, if the amount of polyurethane increases, the adhesion with the fabric will increase, but the waterproofness and moisture permeability will decrease, and conversely, if the amount of polyvinylidene fluoride increases, the moisture permeability and waterproofness will increase, but the adhesiveness with the fabric will decrease. adhesion is reduced. From the above, a good moisture-permeable waterproof fabric can be obtained by adjusting the mixing ratio of polyurethane and polyvinylidene fluoride depending on the required performance of the fabric used and the waterproof fabric to be manufactured. The amount of resin applied in the mixture of polyurethane and polyvinylidene fluoride is not particularly limited;
~40 g/m ² is suitable; below 5 g/m ² the waterproofness is low, and above 40 g/m ² the waterproof fabric will have a stiff texture and the resin cost will be high. Therefore, by adjusting the amount of resin to be coated within this range, more preferably from 15 to 30 g/m ² , a moisture-permeable waterproof fabric with good waterproof properties and a soft feel can be obtained. In addition, when coating a phase-separated mixed solution of polyurethane and vinylidene fluoride, it is possible to apply shear to the resin solution using a method such as knife coating, and then immerse it in a coagulation bath to solidify it before the strain caused by the shear is relaxed. The pores formed are particularly long in the direction parallel to the fabric surface, and the communication ratio of the pores is also increased, which is preferable. The fabric used is not particularly limited, and may include knitted fabrics, woven fabrics, and non-woven fabrics. Of course, any yarn can be used such as spun yarn, filament yarn, processed yarn, etc. As mentioned above, if the adhesion is poor when coating a fabric with a mixed solution of polyurethane and vinylidene fluoride that exhibits phase separation, the adhesion can be improved by pretreatment. For example, in the case of pretreatment by coating or impregnating polyurethane, the polyurethane in the base polyurethane layer does not necessarily have to be the same type of polyurethane contained in the polyurethane and polyvinylidene fluoride mixture. There are two ways. Coating the fabric with polyurethane. When coating a fabric with a polyurethane solution, as shown in FIG.
Preferably, the penetration into the inside of the fabric 3 is slight, and the node point 6 of the thread 5,
By penetrating into the interior of the fabric from 6 and hugging the single fibers 4 floating on the surface, it is possible to achieve moisture permeability, softness and good feel, and improved adhesion. This coating can be adjusted by adjusting the viscosity of the polyurethane solution, and the particle size is 1000.
~100000cps, preferably 5000~
It is in the range of 50000cps. If it is less than 1,000 cps, the penetration into the fabric will be large, and if it is more than 100,000 cps, the penetration into the fabric will be small, and in both cases, the effect of improving adhesion will be poor, which is not preferable. The coating amount of the base polyurethane is preferably 3 to 10 g/m ² . 3
g/ ^m2 , the effect of improving adhesion is poor;
g/m ² , moisture permeability tends to decrease. Impregnate the fabric with polyurethane. A base polyurethane layer is formed in the same manner as above, and the viscosity of the polyurethane solution is adjusted so that the polyurethane penetrates into the fabric to the same extent. The method is similar to. Glue the polyurethane film to the fabric. The method of adhering the polyurethane film is not particularly limited, but examples include methods such as high-temperature adhesion using a polyurethane film with a low melting point, or adhesion of the polyurethane film using an adhesive. However, the method of manufacturing a moisture-permeable waterproof fabric by adhering a polyurethane film to a base polyurethane layer tends to cause a decrease in moisture permeability, so it must be used only for stretchy woven or knitted fabrics. In the present invention, after forming a film of a mixture of polyurethane and polyvinylidene fluoride on a fabric, a water repellent treatment may be performed. This step is carried out to further improve the water repellency of the manufactured moisture permeable waterproof fabric, and fluorine-based, silicone-based, and other water repellents can be used as the water repellent. The amount of water repellent applied is preferably in the range of 0.5 to 10% by weight,
The heat treatment after immersion in the water repellent agent may be carried out at a temperature below the melting point of polyurethane and polyvinylidene fluoride so as not to destroy the characteristic film structure. Next, the manufacturing process of the present invention will be described with reference to Examples, but it is of course not limited to this manufacturing process. Example 1 70 denier nylon - 66 plain weave (warp density 136 pieces/
Processed on one side of 104 wires/in.) Base polyurethane coating A polyurethane solution was coated with a knife coater and wet solidified. The polyurethane used was Crisbon 8166 (Note 1), and the amount of resin applied was 5
g/ ^m2 . Heat treatment Heat treatment was performed at 170°C for 1 minute using a pin tenter. Top Coating A mixed solution of polyurethane, polyvinylidene fluoride, and a solvent for dissolving them was prepared in the following proportions, coated with a knife coater, and then wet-coagulated. The amount of resin applied was 20g/m ² .・Polyurethane (Crisbon 8166) 16.6wt% ・Polyvinylidene fluoride (Kynar 416)
8.3wt% (Note 2) - Dimethylformamide 75.1wt% Heat treatment Heat treatment was performed at 150°C for 1 minute using a pin tenter. Water repellent treatment After immersing in the following aqueous solution, squeeze with a rubber roll to a rate of 30%.
I narrowed it down to - 10 parts of Asahi Card AG770 (Note 3) - 90 parts of water Heat treatment Heat treatment was performed at 150°C for 1 minute using a pin tenter. Note that under the conditions of Example 1, waterproof fabrics were manufactured by varying the mixing ratio of polyurethane and polyvinylidene fluoride in the top coating. (Note 1) Polyurethane manufactured by Dainippon Ink Chemical Co., Ltd., which dissolves in dimethylformamide. (Note 2) Powdered polymer manufactured by Pennwalt Co., USA, dissolved in dimethylformamide. (Note 3) An aqueous emulsion solution containing 28% active ingredient of an organic fluorine compound manufactured by Meisei Chemical Industry Co., Ltd. Example 2 110 denier nylon - 6 plain weave (warp density 60 pieces/
in. weft density 58 lines/in.) Processed on one side Base polyurethane coating A polyurethane solution was coated with a knife coater and wet solidified. Crysbon 8166 was used as the polyurethane, and the amount of resin applied was 7 g/m ² . Heat treatment Heat treatment was performed at 170°C for 1 minute using a pin tenter. Top Coating A mixture of polyurethane, polyvinylidene fluoride, and a solvent was prepared in the proportions shown below, coated with a knife coater, and then wet-coagulated.
Coated resin amount is 25g/m ²・Polyurethane (Crisbon 8166) 12.5wt% ・Polyvinylidene fluoride (Kynar 416)
10.0wt% ・Dimethylformamide 77.5wt% Heat treatment Heat treatment was performed at 170°C for 1 minute using a pin tenter. Water repellent treatment After immersing in the following aqueous solution, squeezing rate 30% with a rubber roll
I narrowed it down to - 10 parts of Asahi Guard AG770 - 90 parts of water Heat treatment Heat treatment was performed at 170°C for 1 minute using a pin tenter. Example 3 70 denier nylon - 66 plain weave (warp density 136 strands/
Processed on one side of 104 wires/in.) Base polyurethane coating A polyurethane solution was coated with a knife coater and wet solidified. Samplen LQ-X5 (Note 4) was used as the polyurethane, and the amount of resin applied was 5 g/m ² . Heat treatment Heat treatment was performed at 170°C for 1 minute using a pin tenter. Top Coating A mixture of polyurethane, polyvinylidene fluoride, and a solvent was prepared in the proportions shown below, coated with a knife coater, and then wet-coagulated.
The amount of resin applied was 25 g/m ² .・Polyurethane (Samplen LQ-X5)
18.0wt% ・Polyvinylidene fluoride (Kynar 416)
8.0wt% ・Dimethylformamide 74.0wt% Water repellent treatment After immersion in the following aqueous solution, squeeze rate 30% with a rubber roll
I narrowed it down to - 10 parts of Asahi Guard AG770 - 90 parts of water Heat treatment Heat treatment was performed at 170°C for 1 minute using a pin tenter. (Note 4) Active ingredient 30 dissolved in dimethylformamide using polyurethane manufactured by Sanyo Chemical Industries, Ltd.
% stuff. Example 4 70 denier nylon - 66 tricot (density 70
Processed on one side of course/in. latitude density 35 wale/in. Base polyurethane adhesive Crisbon 5516S (Note 5) solid content 8 g/m ²
It was coated on a release paper so that it would look like this, and it was adhered tightly with a hot roll. (Note 5) Active ingredient dissolved in dimethylformamide using polyurethane manufactured by Dainippon Ink Chemical Co., Ltd. Top coating A mixed solution of polyurethane, polyvinylidene fluoride, and a solvent was prepared in the following ratio and coated with a knife coater. The amount of resin applied is 20g/
^m2 .・Polyurethane (Chrisbon 8166)
17.5wt% ・Polyvinylidene fluoride (Kynar 416)
8.3wt% ・Dimethylformamide 74.2wt% Heat treatment Heat treatment was performed at 170°C for 1 minute using a pin tenter. Water repellent treatment After immersing in the following aqueous solution, squeeze with a rubber roll to a rate of 30%.
I narrowed it down to - 10 parts of Asahi Guard AG770 - 90 parts of water Heat treatment Heat treatment was performed at 170°C for 1 minute using a pin tenter. The moisture permeability, water resistance, water repellency, and adhesive strength of the moisture permeable waterproof fabrics produced in Examples 1 to 4 were measured, and the results were as shown in Table 1, and these values hardly changed after 5 washes. I stopped talking. Further, Table 2 shows the physical property values of products obtained by changing the mixing ratio of polyurethane and polyvinylidene fluoride under the conditions of Example 1.

[Table] Comparative Example 1 is a vinyl chloride waterproof fabric, and the waterproof fabric of the present invention has excellent moisture permeability and water pressure resistance. (Measurement method) Water repellency JIS L1092 Water resistance JIS L1092 Moisture permeability JIS K6328 Adhesive strength JIS K6328 Bending wear JIS K6328

[Table] When polyurethane and polyvinylidene fluoride undergo phase separation, moisture permeability becomes good. Conversely, if phase separation does not occur, the special membrane of the present invention will not be formed, so moisture permeability will be poor.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a moisture-permeable waterproof fabric according to the present invention, and FIG. 2 is a longitudinal sectional view of a fabric base material and a base polyurethane layer coated thereon. 1... Polyurethane and polyvinylidene fluoride mixed layer, 2... Base polyurethane layer, 3... Fabric base material,
4... Single fiber, 5... Thread, 6... Node point, a... Hole, b...
Stomata, c... communicating pores.

Claims (1)

[Scope of Claims] 1 Consisting of a fabric as a base material and a mixture of polyurethane and polyvinylidene fluoride arranged on the surface layer, the surface of the layer of the mixture of polyurethane and polyvinylidene fluoride has a diameter of 5 microns or less. It has a large number of holes,
Moisture-permeable waterproofing characterized by having long pores in a direction substantially parallel to the surface of the fabric that communicate with the surface pores in the lower part, and communicating pores that communicate between the pores to provide moisture permeability. cloth. 2. When coating the surface layer of a waterproof fabric based on fabric with a mixed solution of polyurethane, polyvinylidene fluoride, and a solvent that substantially dissolves these, when the mixture of polyurethane and polyvinylidene fluoride is formed into a film. A method for producing a moisture-permeable waterproof fabric characterized by using a material that undergoes phase separation, coating polyurethane and vinylidene fluoride with a mixed solution at a mixing ratio that causes phase separation, and wet coagulating.