JPH0517029B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] This invention is a porous material that can be used for clothing such as sportswear, medical or dust-proof outerwear, tarpaulins, sheets for tents, and construction materials such as wall materials. This relates to waterproof fabric. [Prior Art] Fabrics with waterproof coatings tend to condense moisture and sweat inside, causing many problems, so the development of waterproof coatings with breathability and moisture permeability has been progressing. . For example, a coated fabric (Japanese Patent Publication No. 60-47955) that has a microporous film composed of a synthetic polymer mainly composed of polyurethane on at least one side of a fiber base material, a hydrophobic polymer base that is connected to the surface of the base. , and a porous polymer composite having a hydrophilic inner surface with a large number of micropores in which hydrophilic polymers are exposed on the inner surface of the pores (Japanese Patent Publication No. 58-32167), hydrophobic polyurethane, hydrophilic A porous sheet material with a hydrophobic inner surface made by impregnating and/or coating a base material with a W/O type polyurethane emulsion consisting of polyurethane, an organic solvent, and water (Japanese Patent Publication No. 59-33611) has already been developed. ing. In cases where the inner surface of the small pores is formed with a moisture-permeable porous coating that is hydrophobic, the base material itself has poor water absorption and hygroscopicity, and water droplets that are visible to the naked eye may adhere to the material. However, the so-called dew condensation prevention effect cannot be said to be sufficient. On the other hand, porous polymer composites in which the substrate is a hydrophobic polymer and the inner surfaces of the small pores in the substrate are hydrophilic polymers exhibit high water absorption and hygroscopicity, but are used in clothing and other applications. It is not possible to exhibit moisture release or moisture permeability or waterproof properties that suit the purpose, and the manufacturing process is complicated, so it cannot be said to be practically preferable. [Problems to be solved by the invention] As mentioned above, in the conventional technology, porous waterproofing that has water absorption or moisture absorption as well as moisture release or moisture permeability and exhibits a satisfactory dew condensation prevention effect has been developed. There is a problem that processed cloth cannot be obtained, and it has been a challenge to solve this problem. [Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides the following: (1) An acrylic resin, a urethane resin, or a mixed resin thereof is applied to the inner surface of a fabric that has been subjected to a water-repellent treatment and has been smoothed. A waterproof fabric with moisture permeability, which is made by laminating porous layers obtained by coating three layers of W/O type emulsion liquid, and the innermost layer in contact with the fabric has moisture permeability with a hydrophobic substance added therein. an undercoat layer A which is a waterproof layer, a first top coat layer B which is a moisture absorbing layer in which the intermediate layer has a pore diameter containing a hydrophobic substance and a hygroscopic substance in a certain specific ratio and has the largest moisture release effect; Forming a second top coat layer C, the outermost layer of which is a skin layer containing a hydrophobic substance and having the smallest pore diameter to prevent wet back;
The pore diameters of A, B, and C are A<B, B, respectively.
>C, C<A, (2) Each layer of the above-mentioned undercoat layer A, first top coat layer B, and second top coat layer C is made of release paper or other release material. This method employs the following methods to obtain a moisture-permeable waterproof fabric obtained by a transfer lamination method. The details will be described below. First, the fabric serving as the base material in this first invention may be a single, blended, or woven fabric of natural fiber or synthetic resin, or a nonwoven fabric (including a polymer membrane), and there are no particular limitations on the material. However, it goes without saying that it is preferable to use a coating layer that facilitates subsequent processing, has excellent adhesion of the coating layer, and does not fall off easily. The water repellent treatment for such fabrics is not particularly limited, and for example, the commonly used fluorine-based water repellent may be treated with isocyanate compounds, reactive silicone compounds,
The fabric may be soaked or coated with an adhesion improver such as melamine resin, and the water repellent agent may be heated and set on the fabric.The set fabric is then subjected to a thermal calender or the like to smooth at least one side. At this time, it is important to adjust the air permeability to about 5 to 20 c.c./cm ² ·sec. Next, the W/O emulsion liquid of the acrylic resin, urethane resin, or a mixture thereof of the present invention forming the undercoat layer A is prepared by the emulsion polymerization method disclosed in, for example, Japanese Patent Publication No. 58-32167. In 100 parts of a solution (parts are parts by weight, the same applies hereinafter) of a solution obtained by dissolving the acrylic resin dry rubber obtained by using an organic solvent such as toluene, ethyl acetate, or methyl ethyl ketone to a solid content of 10 to 30% by weight,
It is prepared by adding and mixing 8 to 50 parts of water and a small amount of surfactant, and it is also a urethane resin W/
Methods for producing O-type emulsions have already been disclosed in Japanese Patent Publication No. 48-4380, Japanese Patent Publication No. 57-47928, Japanese Patent Publication No. 33611-1980, etc., but the method for producing O-type emulsion has already been disclosed in Japanese Patent Publication No. 48-4380, Japanese Patent Publication No. 57-47928, Japanese Patent Publication No. 33611-1983, etc. It is made by dispersing water in resin. Here, the reason why the W/O type emulsion is used is that the O/W (oil in water) type emulsion does not produce a porous film after drying, and also uses acrylic resin, urethane resin, etc. solid content concentration of 10~30
The reason why the amount is adjusted to % by weight is that if the amount is less than 10% by weight, the effect of the resin will not be apparent, whereas if the amount is more than 30% by weight, the viscosity will increase and it will be difficult to obtain a homogeneous coating film. Further, the crosslinking agent of the present invention is preferably an isocyanate type for the resin, such as methylene-bis-phenyl isocyanate, hexamethylene diisocyanate, methylene-bis-4cyclohexylic isocyanate, isophorone-diisocyanate, trimethylolpropane- Examples include hexamethylene diisocyanate, but the material is not limited to these as long as it crosslinks the resin and adheres to the base fabric and forms predetermined micropores. Such a crosslinking agent may be added in an amount of about 0.1 to 0.5 parts to 100 parts of the mixed liquid. Note that it is preferable to add a hydrophobic substance, such as a solvent-type or water-based fluororesin, when adding the crosslinking agent, since this improves the property of preventing water leakage from the outside of the base fabric. The thus obtained W/O type resin mixture can be coated with a knife coat, reverse coat, etc. to give a coating density of 10 to 30 g/m ² in a wet state and 2 g/m 2 in a dry state.
It is applied to the fabric surface of the base material in an amount of ~5 g/m ² to form a porous undercoat layer A having micropores with a pore diameter of approximately 2 to 5 μm. Furthermore, a moisture absorption layer B having a moisture release effect is formed on the undercoat layer A. At this time, the hydrophobic polymer added to the W/O emulsion of acrylic resin, urethane resin, or a mixed resin thereof is a solvent. Type fluororesin such as perfluorooctyl acrylate compound, chromium coordination compound of saturated fluorine monobasic acid, polytetrafluoroethylene compound, acetone, methyl isobutyl ketone, 1,1,
1. It is dissolved in a solvent such as trichloroethane, and the hydrophilic polymer is a water-based dimethyl silicone compound with a functional group such as an epoxy group, an amino group, or an alkoxysilane at its terminal group, or a polyalkylene compound. It is a dimethyl silicone compound containing 10 to 80% by weight of a polyester compound derived from hydrophilic glycols such as glycol. The blending ratio of these hydrophobic polymers and hydrophilic polymers is 1 to 5% solid content for hydrophobic polymers and 1 to 5% solid content for hydrophilic polymers based on the solid content of the W/O emulsion resin. The appropriate solid content is 5 to 40%. This is because, in the case of a hydrophobic polymer, if the amount is less than the specified amount, it will not be able to maintain water pressure resistance and the moisture release function will also decrease, whereas in the case of a hydrophilic polymer, the moisture absorption and dew condensation prevention properties will be insufficient. If the amount exceeds the specified amount, hydrophobic polymers will inhibit moisture absorption and dew condensation prevention, and hydrophilic polymers will inhibit the retention of water pressure, resulting in damage to the formed film. This is because strength cannot be maintained and this is not preferable. By changing the blending ratio of these hydrophobic and hydrophilic polymers, the properties of the inner surface of the pores can be adjusted as desired, making it possible to change the moisture absorption and moisture release properties. Moreover, the present invention will not be affected by adding a hygroscopic, water-absorbing urethane resin or other hygroscopic, water-absorbing substance in place of the aqueous dimethyl silicone compound. Then, the crosslinking agent (isocyanate) is added to the resin mixture and coated on the undercoat layer A using, for example, a bar coder, in a wet state of 120 to 350 g/m ² and in a dry state of 18 to 55 g/m 2 .
Apply evenly to cover ² m2. This is 50~100℃,
After drying for about 1 to 3 minutes, the first top coat layer B
is formed. This first top coat layer B is similar to the undercoat layer A, in which the organic solvent in the applied mixture evaporates in order of boiling point, a coagulated film is formed on the surface of the paint film in contact with air, and then the inside of the paint film is mixed. As water evaporates from the liquid and micropores are formed for this purpose, the crosslinking reaction gradually progresses and hardens, so it is usually best to dry the coating film at a temperature of 40 to 130°C. The resulting porous layer is 5 to 8 μm (average about 6 μm)
It is composed of pores with a diameter of . Furthermore, the surface of the hygroscopic B layer has scratch resistance,
In order to provide strength properties such as abrasion resistance and to prevent the reflow of sweat absorbed in the moisture absorbing layer, a different type of urethane resin W/ is applied on the B layer.
A second top coat layer C having different pore diameters (0.5 to 1.0 .mu.m) may be formed by adding an O-type emulsion liquid and a hydrophobic polymer, changing the blending ratio of solvents, etc., and forming a so-called skin layer. It is also possible to add functional inorganic powders such as aluminum, ceramics, carbon, or colorants to this skin layer at the time of compounding, to the extent that it does not impede the objective effects of the present invention. The liquid can also be coated with a knife coat or gravure coat at a rate of 5 to 25 g/m ² in a wet state and 0.5 to 0.5 g/m 2 in a dry state.
Using 5.0 g/m ² as a guideline, it is possible to apply it all over the surface or in dots, or even add a pattern to it to add a unique decorative effect. In addition,
Drying conditions are usually 50 to 100°C and 30 to 180 seconds. The resulting porous skin layer is constituted by finer pores than the first top coat layer B of 0.5 to 1.0 .mu.m. As mentioned above, it is preferable to waterproof the base fabric, apply a porous undercoat layer A, a first top coat layer B, and a second top coat layer C in sequence thereon, and then apply a finishing set. . The conditions may be 100-140℃ and 30-180 seconds,
It is not limited to these. Next, although the fabric that is the base material of the second invention is not essentially different from the above-mentioned fabric, the stretchability of the base material is better utilized especially when targeting knitted fabrics and woven fabrics that have high stretchability. It is desirable in that it can be done. In such a case, first, use an extruded polypropylene laminated release paper, and coat it with the above-mentioned second top coating liquid using a reverse coater or the like in a wet state at a rate of 5 to 25 g/m ² as a guideline. The drying conditions are usually 50 to 100℃.
It is dried for about 30 to 180 seconds to first form a second top coat layer (skin layer) C. Further, the first top coating liquid described above is uniformly applied thereon using a barcoder or the like so that the coating weight is 120 to 350 g/m ² in a wet state. This drying condition is usually 50~
100°C for about 1 to 3 minutes is sufficient. Here, a first top coat layer B is formed. Next, an undercoat layer A is applied on the film thus formed.
Apply the undercoat liquid. This is a W/O emulsion liquid of acrylic resin, urethane resin, or a mixture of these resins as the above-mentioned mixed liquid, and the hydrophobic substance added internally is also the same, and the isocyanate-based crosslinking agent is added to 100 parts of the mixed liquid. Add 1.0 to 5.0 parts to 70 to 150 g/m ² in wet state.
Apply it evenly. On top of this, a base fabric is laminated in a wet state, wet lamination is performed, and after drying at 60-80℃ for 1-3 minutes, a linear pressure of 1-2 is applied using a hot roll at 50-100℃.
Apply pressure of kg/cm and roll up the release paper together with the fabric. Laminated fabric rolled up with release paper is 24 to 48
After a period of maturing time, the coating fabric is peeled off from the release paper and subjected to water repellent treatment using the same water repellent agent as described above. For example, this condition is 100 to 140
℃ for 30 to 180 seconds, but is not limited to this. [Function] Each of the porous layers of the laminated porous waterproof fabric described above has the following characteristics. That is, the undercoat layer A has a pore diameter of approximately
The first top coat layer B has a pore size of 5 to 8 μm and is similar to the undercoat layer A, which has a pore size of 5 to 8 μm.
It is larger and has both hydrophilic and hydrophobic properties,
It does not retain water, but forms a layer that has hygroscopic and moisture-releasing properties, and actively absorbs sweat that diffuses from inside. And the second top coat layer C has a thickness of 0.5 to 1.0 μm.
It is the smallest, has hydrophobic properties, is resistant to abrasion, eliminates stickiness on surfaces that come into contact with the skin, and does not return absorbed sweat. Therefore, each laminated layer fully exhibits functions such as moisture permeability, prevention, dew condensation prevention, moisture release, and ventilation. [Example] Example 1 A dyed cloth made of nylon fiber (70d, 210 fibers) was
Fluorinated water repellent (Sumitomo 3M: FC232)
2 parts to 100 parts) and an isocyanate compound as an adhesion agent (Takenate B830W, manufactured by Takeda Pharmaceutical Co., Ltd., at a concentration of 10% to the above fluorine-based water repellent). After that, heat treatment is performed at 160℃ for 60 seconds, and heat treatment is performed to give smoothness to one side of the fabric using a thermal calender at 150℃ and a linear pressure of 10 tons (width 2000mm). A water-repellent fabric with a water repellency of about 15 c.c./cm ² ·sec was obtained. On the other hand, W/O type polyurethane resin emulsion (manufactured by Sanyo Chemical Industries, Ltd.: Sample UE-
A mixed solution of 100 parts of 1000N), 40 parts of toluene, 20 parts of methyl ethyl ketone, 10 parts of water, 20 parts of a fluorine-based water repellent (mentioned above), and 5 parts of an isocyanate compound (manufactured by Dainippon Ink Chemical Co., Ltd.: Burnok DN950) was prepared. This liquid was applied to the water-repellent fabric using a knife coating method so that the wet weight of the fabric was 20 g/m ² , and a porous undercoat layer A was formed with a dry weight of 3.5 g/m ² . was formed. Furthermore W/
100 parts of O-type urethane resin emulsion (manufactured by Dainippon Ink Chemical Co., Ltd.: XOLTEXPX-100F), 20 parts of methyl ethyl ketone, 20 parts of toluene, 40 parts of water, 2 parts of solvent-based fluororesin (manufactured by Dainippon Ink Chemical Co., Ltd.: Deitskugard F320) , nonionic dimethyl silicone emulsion (manufactured by the same company: silicone softener)
120) 20 parts and isocyanate compound (listed above)
Prepare a mixed solution consisting of 0.5 parts, and apply this solution onto the undercoat layer with a clearance of 250 μm.
Using ^a bar coater set to
The first top coat layer B was obtained by heating and drying for a minute. On top of this, the amount of water was reduced, the amount of isocyanate compound was increased, and aluminum powder and coloring materials were added to improve wear resistance and decorative effects. Manufactured by: Sampleran UE1000N) 100 copies,
20 parts of methyl ethyl ketone, 20 parts of toluene, 20 parts of water
Part, solvent-type fluororesin (manufactured by Dainippon Ink Chemical Co., Ltd.:
Prepare a liquid mixture consisting of 2 parts of Deckguard F320), 3 parts of the isocyanate compound (listed above), 5 parts of aluminum powder, and a small amount of colorant, and apply this on top of the first top coat layer B as the second top coat layer C in a wet state. 15g/m ² , 3g/m ² in dry state, dried at 80℃ for 2 minutes, then coated at 120℃ for 2 minutes.
Finish setting was performed by heating for a minute. In order to confirm the characteristics of the obtained porous waterproof fabric, water pressure resistance (water pressure mm based on JIS-L-1096), water repellency (% based on JIS-L-1096), and moisture permeability (JIS-Z-
0208, g/m ² /24h), anti-condensation properties and abrasion resistance were investigated. Here, for anti-condensation property, 80
Cover the sample cloth in a 200 ml beaker containing 100 ml of hot water at ±5°C, observe the state of the coating layer surface after 3 minutes, and then cover the same area in the beaker for 5 minutes (8 minutes after the beginning). ), the coating layer was observed again and evaluated on a five-point scale according to the following criteria.
In other words, the sample fabric absorbs and releases moisture, and no water droplets are observed.
...Some grade 5 water droplets remain, but they disappear within 10 seconds. ...4〃 Water droplets remain, but if you wipe them gently with your hand, they will disappear.
...3〃 The remaining water droplets do not disappear even if I wipe them off with my hand. ...2〃 The sample fabric hardly absorbs moisture and leaves a lot of water droplets.
...1〃. In addition, in the abrasion resistance test, the condition of the resin surface of the sample fabric was evaluated on a five-grade scale when a load of 200 g was applied to the sample fabric surface and the sample fabric was moved back and forth 500 times using dry and wet cotton fabric. In other words, no abnormality is observed...some scratch marks of grade 5 are observed. ...4〃 Considerable scratch marks are observed. ...3〃 Some peeling is observed. ...2〃 Considerable peeling is observed. ...1〃. The above measurement results are summarized in a table.

【table】

〔effect〕

As described above, in the porous waterproof fabric of the present invention, the ratio of hydrophobicity to hydrophilicity on the inner surface of the micropores can be adjusted as appropriate depending on the application, and the porous fabric with different pore diameters can be used. By laminating various combinations of layers, it has excellent moisture permeability, moisture absorption, and moisture release properties as well as waterproofness, and has far better anti-condensation properties than conventional products, so even if you sweat during intense exercise, your skin will stay dry. A lot of condensation does not appear on the sides and causes discomfort. Therefore, it can be said that the significance of this invention is extremely large.

Claims (1)

[Claims] 1. A porous layer obtained by coating the inner surface of a water-repellent and smoothed fabric with three layers of a W/O emulsion liquid of an acrylic resin, a urethane resin, or a mixed resin thereof. The innermost layer in contact with the fabric is an undercoat layer A, which is a moisture-permeable waterproof layer containing a hydrophobic substance, and the middle layer is a hydrophobic substance and a moisture-absorbing layer. The first top coat layer B is a moisture absorbing layer that has the largest pore diameter and has the largest moisture releasing effect, and the outermost layer has a hydrophobic substance added therein at a specific ratio and has the smallest pore diameter to prevent wet back. Moisture permeability characterized by forming a second top coat layer C which is an effective skin layer, and having the pore diameters of A, B, and C in the relationships of A<B, B>C, and C<A, respectively. Waterproof fabric. 2 Moisture permeability obtained by a transfer lamination method in which each of the undercoat layer A, first top coat layer B, and second top coat layer C described in claim 1 is laminated on release paper or other release material. Waterproof fabric.