JPS60126386A - Non-permeable hygroscopic and water-vapor releasing waterproof sheet - Google Patents

Abstract

PURPOSE:An non-permeable hygroscopic and water-vapor releasing waterproof sheet, comprising a fibrous base cloth having dispersed water-insoluble water absorbing substance and a specific non-permeable waterproof coated layer having dispersed powder of a water-insoluble water-absorbing substance having water vapor permeation at least one side of the base cloth. CONSTITUTION:A fibrous base cloth obtained by dispersing a water-insoluble water- absorbing substance (e.g., substance made of pulp, saponified polyacrylonitrile, etc. capable of absorbing >=100 times as much water as its weight) onto woven and knitted goods or nonwoven fabric made of synthetic fiber subjected to hydrophobic and water repellent treatment is provided with a processing solution obtained by dispersing water- insoluble water-absorbing solid powder into a non-permeable polymer material having water vapor permeation made of a polymer material selected from synthetic resin and rubbers, such as silicone resin or polyurethane resin having >=100g/m<2>.24hr water vapor permeability, to form a non-permeable waterproof film having water vapor permeation on one side or both sides of the base cloth. Since the titled sheet has non- permeable waterproofing, sweating is not produced, sufficient hygroscopicity and water- vapor releasing properties are shown.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a non-breathable tarpaulin sheet, and more specifically, to a non-breathable tarpaulin sheet having moisture absorbing and releasing properties.

Conventional technology Conventionally, waterproof sheets used for truck hoods, cargo seats, etc. are made of fabrics made of natural fibers such as cotton, paraffin,
Those treated with waterproofing such as metal soap were used. The gaps between these weaves are not completely blocked by the waterproofing agent, so air and moisture can pass through the gaps.
It had the advantage of not producing stuffiness or condensed water inside. However, the strength of natural fibers is relatively low, and therefore, in order to obtain a sufficiently strong sheet, it must be made of thick material, which has the disadvantage of increasing weight. For this reason, synthetic fiber sheets, which have high strength and are lightweight, have recently come into widespread use.

However, in the case of synthetic fiber sheets, they are inherently hydrophobic and lack water-swelling properties, whereas conventional cotton sheets had the advantage of gradually swelling when they absorbed water, thereby preventing water leakage. On the other hand, this result can be expected from synthetic fibers. Therefore, in order to obtain a sheet that does not allow any water to pass through, it is necessary to form a completely impermeable waterproof coating on the surface of the base fabric. When a canopy or the like is constructed using such a synthetic fiber waterproof sheet, there is a problem that condensed water is generated inside the tarpaulin sheet, which may fall and cause an accident such as wetting cargo or the like.

Various attempts have been made to solve these problems, but satisfactory results have not always been obtained.

The applicant has conducted various studies to solve these problems with synthetic fiber waterproof sheets, and although the problem of non-water swelling due to the hydrophobicity of the base fabric itself is unavoidable, the non-breathable waterproof coating It has been discovered that the problem of condensed water that forms on waterproof coatings can also be solved by imparting water absorption properties. That is, a non-breathable waterproof coating made of synthetic resin, rubber, etc. is formed on one or both sides of a hydrophobic fibrous base fabric, and solid powder particles of a water-insoluble water-absorbing substance are dispersed and contained in this coating. Invented a new waterproof sheet. As a result of further investigation, it was found that the non-breathable film was formed from a moisture-permeable polymer material rather than the relatively hydrophobic material used in the past, while the sheet contained a water-insoluble water-absorbing material. The present invention has been completed based on the discovery that a waterproof sheet with excellent water condensation prevention effect can be obtained by containing the following.

Structure of the Invention The non-breathable moisture-absorbing and desorbing waterproof sheet of the present invention comprises a fibrous base fabric and a polymer material formed on at least one surface thereof and made of at least one selected from synthetic resins and rubbers. and a non-breathable waterproof coating layer containing as a main component, the fiber base fabric having a water-insoluble water-absorbing substance, and the non-breathable waterproof coating layer having moisture permeability. In addition, solid powder of a water-insoluble water-absorbing substance is dispersed and contained in the coating, using the coating as a matrix and separated from each other.

Another non-breathable moisture-absorbing and desorbing waterproof sheet of the present invention is mainly composed of a fibrous base fabric and a polymer material formed on both sides thereof and made of at least one selected from synthetic resins and rubbers. A waterproof sheet comprising two non-breathable waterproof coating layers as components, wherein the fiber base fabric contains a water-insoluble water-absorbing substance, and the non-breathable waterproof coating layer on one side is transparent. Solid powder of a water-insoluble water-absorbing substance is dispersed and contained in the moisture-impermeable waterproof coating layer separated from each other, and the impermeable waterproof coating layer on the other side is moisture-impermeable. It is characterized by

3. Detailed Description of the Invention The waterproof sheet of the present invention comprises a fibrous base fabric and a non-breathable waterproof coating layer containing a moisture-permeable polymer material formed on one or both sides thereof.

The fibrous base fabric is not particularly limited, but it is preferably hydrophobic; for example, it may be a knitted fabric, a nonwoven fabric, etc. made of natural fibers that have been previously treated to be water repellent, or it may be inherently hydrophobic. Synthetic fibers, knitted fabrics, non-woven fabrics, etc. of synthetic fibers that have been treated to be water repellent may also be used. Furthermore, it is also possible to mix water-repellent treated natural fibers with hydrophobic, synthetic or inorganic fibers. These fibers are spun and filamented.

It may be any of suzolit, monofilament, tape-like material, etc., and these are used in the form of knitted fabric, non-woven fabric, paper-like material, etc., and the fiber density thereof can also be freely selected.

Conventionally known methods can be applied to the water repellent treatment applied to the fibrous base fabric in advance. For example, the fibrous fabric can be scoured and dried in advance, or treated with aluminum stearate without any pretreatment. , zinc stearate, acrylates of fatty acid amines, alkylmelamine or paraffin emulsion mixtures thereof, zirconium salts such as zirconium acetate, roughin, silicone or fluorine-based water repellents, etc. Treat with liquid and dry. In this case, these water repellents are generally 0.1
~4.0% by weight is deposited.

Characteristic parts of the present invention will be explained in detail. In the present invention, the non-breathable moisture permeable waterproof coating layer formed on one or both sides of the base fabric is based on JIS-Z-0208-1976 "Moisture permeability test method for moisture-proof packaging materials (cup method)", condition B ( temperature 4
0±0.5℃, relative humidity 90±2%), film thickness 20μ, 100y/rrI2・24 hours or more, preferably 500b2・24 hours or more, more preferably 1
000g//rr+2 ・The main component is a polymer material that exhibits moisture permeability for 24 hours or more. Examples of polymer materials with such moisture permeability include silicone resin, urethane resin manufactured by Dainippon Ink and Chemicals, and CR.
There is ISVON-3314-EL. Incidentally, the moisture permeability of relatively hydrophobic film-forming polymer materials commonly used in the past, such as PVC, is 80.97 g//m2.
・24 hours of normal polyurethane is 94.52
1//m2 for 24 hours, and it has been common sense to use such a moisture-impermeable polymer material for the purpose of waterproofing.

In the waterproof coating layer containing a moisture-permeable polymer material, the air bubbles may exist uniformly on the entire surface, or may exist partially, for example, on the outer surface side excluding the inner surface on the base fabric side in the cross-sectional direction. The unevenly distributed bubbles may be present over the entire surface direction or regionally. These air bubbles are effective in increasing the moisture permeability of the waterproof coating layer.

There is no particular limitation on the weight of the waterproof coating layer containing the moisture-permeable polymer material as described above, but generally the weight is 5 to 5 on the fiber base soil surface.
The thickness is preferably in the range of 00 &An, and the thickness is not particularly limited, but is preferably 100μ or less, further preferably 50μ or less, and more preferably 5 to 30μ. In addition, the base fabric is impregnated with a waterproofing agent containing a moisture-permeable polymer material, and the waterproofing agent is coated on the surface of the base fabric to a thickness of 5 to 50%.
Preferably, a coating of 10 μm is formed.

In another embodiment of the waterproof sheet of the present invention, the above-mentioned waterproof coating layer containing the moisture-permeable polymer material is formed on one surface (preferably on the inner surface) of the fibrous base fabric, and on the other surface (preferably Some have a waterproof coating layer containing a moisture-impermeable polymer material formed on the outer surface.

The moisture-impermeable polymer material mentioned above refers to a polymer material that exhibits a moisture permeability of less than 100 Iq/m 2 for 24 hours in the same moisture permeability test as described above.

Moisture-impermeable polymeric materials such as those described above may be used, for example, polyvinyl chloride (PVC), ethylene-vinyl acetate copolymer, etc.
EVA), moisture-impermeable polyurethane, polyacrylic resin, nylon 6.66, 12° polyester resin, fluororesin and other known synthetic resins for waterproofing, natural rubber, chlorosulfonated polyethylene rubber (Hypalon), and silicone rubber. Mu.

It is made of at least one kind selected from neoprene rubber, fluorocarbon +'PVC graftomer (ethylene-acetic acid bee-PVC terpolymer), and other known synthetic polymers.

The above-mentioned waterproof coating layer containing a moisture-permeable polymer material and the waterproof coating layer containing a moisture-impermeable polymer material can be formed on a desired surface of a fibrous base fabric by a calendering method, a laminating method, a topping method,
It can be formed by applying a polymer material by a coating method, dipping method, or other known method.

There is no particular limitation on the weight of the waterproof coating layer containing a moisture-permeable polymer, but in general, the weight of the upper surface of the fibrous base fabric is 5~! 50011/m
It is preferable that it is within the range of . There is also no particular limitation on the weight of the waterproof coating layer containing a moisture-impermeable polymer, but it is generally preferably within the range of 5 to 500,777 m2 on the upper surface of the fibrous base fabric. Although the thickness of these coating layers is not particularly limited, it is preferably 100 μm or less, more preferably 50 μm or less, and more preferably 5 to 30 μm.

Alternatively, a waterproof coating layer containing a moisture-impermeable polymer may be formed inside the waterproof coating layer containing a moisture-permeable polymer and integrated with the fibrous base fabric, and a moisture-permeable coating layer may be present on the outermost surface.

In the present invention, solid powder particles of a water-insoluble water-absorbing substance are dispersed and dispersed in the above-mentioned non-breathable, moisture-permeable, waterproof synthetic resin or rubber that forms the non-breathable, moisture-permeable waterproof coating. . If the powder particles are in contact with each other, they will form continuous water holes in the coating, and therefore will not be able to exhibit excellent water resistance. The water-absorbing substance particles may be dispersed uniformly in one coating, or depending on the purpose, they may be present with a difference in concentration in a specific part of the coating layer. It may be present so as to be concentrated at the interface with the sexual coating.

In the waterproof sheet of the present invention, the fibrous base fabric further contains a water-insoluble water-absorbing substance. This water-insoluble water-absorbing substance is not limited to a specific form, but is preferably a solid powder or a fibrous material, and may be uniformly dispersed and held in a fibrous fabric, or a fibrous material. It may be dispersed and maintained in a particularly concentrated manner in a specific part of the fabric, for example, in a surface layer part on one side or both sides. These solid powder or fibrous particles, which may be held together by an adhesive, are preferably dispersed apart from each other.

The water-insoluble water-absorbing substance is preferably one that does not dissolve in water but has the ability to absorb water that is 10 times or more its weight, and preferably has the ability to absorb water that is 100 times or more its weight. It is more preferable that the Examples of such substances include, for example, pulp materials or water-soluble polymer substances that are cross-linked using a cross-linking agent or modified to be water-insoluble by replacing some of the hydrophilic groups with lipophilic groups. Examples include, but are not limited to, crosslinked polyethylene oxide, polyvinylpyrrolidone, sulfonated polystyrene, or sodium polyacrylate, cellulose derivatives, saponified products of polyacrylonitrile or starch-acrylonitrile graft copolymers, etc. isn't it. Among these, the DEFF-F7-7 crylonitrile graft copolymer has a water absorption capacity several hundred times higher than its own weight, making it a preferable material for the purposes of the present invention. Sufficient care must be taken as there is a risk of structural damage.

Other particularly preferred water-absorbing substances in the present invention include, for example, self-crosslinked alkali metal acrylic salt polymer (JP-A-53-46389), saponified vinyl ester and ethylenically unsaturated carboxylic acid or copolymers thereof, vinyl Saponified copolymers of esters and acrylic (or methacrylic) esters (JP-A-53-50290), copolymers of vinyl alcohol/acrylic acid salts9, and contain at least 85% by weight of acrylonitrile. Substantially crosslinked polyacrylonitrile fibers obtained by treating acrylic fibers with hydroxylamine or hydrazine, or formalin treatment in the presence of a basic catalyst, and powder thereof, chelating the side chains. Also effective are polymers having chelating crosslinks (Japanese Unexamined Patent Publication No. 48-74'547), which are composed of water-soluble polymers having functional groups.

The water absorption ability of a water-insoluble water-absorbing substance is determined by dispersing a certain amount of the water-absorbing substance in ion-exchanged water, stirring the dispersion slightly, and then leaving it at room temperature for 30 minutes to allow the water-absorbing substance to fully absorb water and swell. After removing excess water, the weight of the absorbed water-absorbing material is measured, and the ratio of this weight to the weight before water absorption is expressed.

There is no particular limitation on the amount of the water-insoluble water-absorbing substance to be contained in the fibrous base fabric, but it is generally 0.1 to 200v-
It is preferable that the weight is . Water-insoluble water-absorbing substances are
It may be adhered to the fibrous base fabric by an outer waterproof film-forming polymeric material that is dispersed and retained in the fibrous base fabric alone, or it may be adhered by an adhesive. Alternatively, these may be applied by spraying as an adhesive.

The waterproof sheet of the present invention has at least one waterproof coating layer containing a moisture-permeable polymer material. Moisture in the outside air that is in contact with this waterproof coating layer is absorbed by the waterproof coating layer and released. This prevents water droplets from condensing on this surface. In addition, when the fibrous base fabric has water absorbency, the absorbed moisture is
The moisture is retained by the fibrous base fabric and released through the waterproof coating layer. Unfortunately, the coating contains solid powder of water-insoluble water-absorbing substances, so even if a crack occurs in the coating, water will not seep in due to the swelling action of the water-absorbing substance present in the crack. can be prevented. Moreover, since the solid powders of the water-absorbing substance are dispersed apart from each other in the impermeable waterproof coating, even if they absorb water, the water will not leak through the waterproof coating.

Next, the waterproof sheet of the present invention will be further explained using examples.

Example 1 A polyester fiber canvas gray fabric having the following specifications: Fabric weight: 360,177 m2 was treated with 1.5% by weight of zinc stearate as a water repellent, and dried at 90°C for 1 minute.

On one side of this water-treated cloth, the following composition was applied: a water-insoluble water-absorbing agent (KI Dal-201 powder).

A mixture of 1 part by weight of isobutylene-maleic anhydride copolymer (manufactured by Kuraray Soprene Chemical Co., Ltd.) and 3M parts of EVA solution for adhesion was applied thinly, and a water-absorbing substance 20 jlAn2 was applied.
A zero layer was formed and used as a base fabric.

This base fabric had the following composition: IHAULAc A-Color' 10 parts (pigment manufactured by Dainippon Ink and Chemicals Co., Ltd.) 1 (AULACA-
Co1or 10 parts (pigment manufactured by Inu Nippon Ink Chemical Industry Co., Ltd.) IPA (solvent) 13 parts toluene (solvent)] 33 parts Note: 120 μ thick, moisture permeability of approximately 3,500 g/m"24 hours] After soaking, squeeze with a roller, 70~
Processed at 120℃ for 3 minutes, resin solid content adhesion rate: 395
A product (sample ■) of 1 part m2 and a film thickness of 20 μm on one side was obtained. Approximately 21,097m2 on both sides of the base fabric of this product.
A coating layer was formed.

The water resistance of Sample I was 1.500% or more in water column. A tent (2m x 2m x 2m) was made using this sample (2), and the air inside the tent was kept at a temperature of 40°C.

The relative humidity was adjusted to 80 parts, and this was left outdoors at a minimum temperature of 5° C. overnight. No condensation was observed on the inner surface of this tent.

Example 2 PVC Leno 7 was applied to the same base fabric as described in Example 1.
80 parts by weight Butyl benzyl phthalate 68 Epoxidized dog bean oil 7 Calcium carbonate 20 Cd-Ba stabilizer 3 Pigment 8 Toluene (diluent) 30.

One side was coated with Loe's solution consisting of the following, dried at 90°C for 1 minute, and then heat-treated at 160°C for 1 minute to obtain a film thickness of 0.2
mm (2409 parts m ) of non-breathable hydrophobic membrane,
Furthermore, the Kaloe liquid of Example 1 was applied to one side (film thickness 70μ).
, application fi=75! ; I/m), and the same heat treatment as in Example 1 was performed to obtain sample (2). For comparison, pvc
A sample (2) with only the blended processing liquid adhered to both surfaces was prepared and tested for the presence or absence of dew condensation on the inner surface of the tent by the method described in Example 1. As a result, no dew condensation was observed in the tent of sample (2) since a moisture-permeable membrane was used on the inside, but a large amount of condensation was observed on the inner surface of the tent of sample (2).

As a result of these tests, it was found that the non-breathable moisture absorbing and desorbing waterproof sheet according to the present invention is extremely effective in preventing dew condensation.

In the case of sample (2), since a waterproof coating layer containing a moisture-impermeable polymer material was used on the outer surface, it exhibited satisfactory waterproofness even in heavy rainfall.

In the case of sample (1), a case in which a moisture-permeable membrane or a moisture-impermeable membrane was combined with the water-absorbing substance holding surface was also investigated, and almost the same effect was obtained. However, the effect of absorbing and releasing moisture seemed to be better when a moisture permeable film was applied to the moisture absorbent holding surface.

Effects of the Invention The waterproof sheet of the present invention does not cause dew condensation on the surface of the waterproof coating containing a moisture-permeable polymer material, even though it is non-breathable waterproof. It can exhibit excellent moisture absorption and desorption properties and waterproof properties.

patent applicant Heigang Textile Co., Ltd. patent application agent Patent Attorney Akira Aoki Patent attorney Kazuyuki Nishidate Patent Attorney Yoshi 1) Keio Patent attorney Akira Yamaguchi Patent Attorney Masaya Nishiyama

Claims (1)

[Scope of Claims] 1. Non-breathable material formed on at least one surface of a fibrous base fabric and containing as a main component a polymeric material consisting of at least a species selected from synthetic resins and rubbers. A waterproof sheet comprising a waterproof coating layer, wherein the fiber base fabric contains a water-insoluble water-absorbing substance, and the impermeable waterproof coating layer has moisture permeability and uses this coating as a matrix. A non-breathable moisture-absorbing and desorbing waterproof sheet characterized in that solid powder of a water-insoluble water-absorbing substance is dispersed and contained in the coating. 2. JIS-Z-02 of the non-breathable moisture permeable waterproof membrane
08-1976 "Moisture permeability test method for moisture-proof packaging materials (cup method)" When the moisture permeability based on condition B is 1 when the film thickness is 20μ
0011An The waterproof sheet according to claim 1, which has a water resistance of 24 hrs or more. 3. The waterproof sheet according to claim 2, wherein the moisture permeability is 5001//m 24 hrs or more. 4. The waterproof sheet according to claim 3, wherein the moisture permeability is 1000 g/m 24hrs or more. 5. The waterproof sheet according to claim 1, wherein the impermeable moisture permeable waterproof coating contains air bubbles. 6. The moisture permeable polymeric material has a rating of 10 in the test.
The waterproof sheet according to claim 1, which is selected from silicone resins and urethane resins that exhibit moisture permeability of 0 #/m for 24 hours or more. 7. The waterproof sheet according to claim 1, wherein the water-insoluble water-absorbing substance has the ability to absorb water 10 times or more the amount of N thereof. 8. The waterproof sheet according to claim 7, wherein the water-insoluble water-absorbing substance has the ability to absorb 100 times or more of its weight in water. 9. The water-insoluble water-absorbing substance is a pulp-made substance. 7Rose derivatives, saponified polyacrylonitrile products. Saponified starch-acrylonitrile graft copolymer 1
Intramolecularly crosslinked acrylic acid alkali metal salt polymer, saponified copolymer of vinyl ester and ethylenically unsaturated carboxylic acid or its ester, saponified copolymer of vinyl ester and acrylic ester, and vinyl alcohol The waterproof sheet according to claim 1, comprising at least one type selected from a copolymer of acrylic Ill and acrylic Ill. ]0. The waterproof sheet according to claim 1, wherein the amount of the water-insoluble water-absorbing substance contained in the fibrous base fabric is within the range of 0.1 to 20,017 m2. 11. The waterproof coating layer containing the moisture permeable polymer material is 5 to 5
Claim 1 having a capacity of G O&/rr
Tarpaulin sheet as described in section. 12. A fibrous base fabric, and two non-breathable waterproof coating layers formed on both sides of the fabric and containing as a main component a polymer material made of at least one kind selected from synthetic resins and rubbers. In the waterproof sheet, the fiber base fabric contains a water-insoluble water-absorbing substance, and the non-breathable waterproof coating layer on one side has moisture permeability, and the non-breathable waterproof coating layer contains a water-insoluble water-absorbing substance. An impermeable moisture-absorbing and desorbing waterproof sheet, characterized in that solid powders of a water-absorbing substance are dispersed and contained separately from each other, and the impermeable waterproof coating layer on the other side is impermeable to moisture. 13. JIS-Z-0 of the non-breathable moisture permeable waterproof coating
208-1976 "Moisture permeability test method for moisture-proof packaging materials (cup method)" When the moisture permeability based on condition B is 20μ,
100,! The waterproof sheet according to claim 12, which has a water resistance of i'/m ·24 hrs or more. 14. The waterproof sheet according to claim 13, wherein the moisture permeability is 500 g/m24 hrg or more. 15. The moisture permeability is 1000. ! i'/'m 24hr
s or more. 16. The waterproof sheet according to claim 12, wherein the non-breathable moisture permeable waterproof coating containing a water-absorbing substance contains air bubbles. 17. The moisture-permeable polymeric material exhibits 1 in the test.
．． 0011An - The waterproof sheet according to claim 12, which is selected from silicone resins and urethane resins that exhibit moisture permeability for 24 hours or more. 18. The moisture-impermeable polymeric material, in the test,
100 minutes - Polyvinyl chloride, ethylene-vinyl acetate copolymer, polyurethane, polyacrylic resin, nylon 6, nylon 66, nylon 12. Claims consisting of at least one selected from polyester iHL chlorosulfonated polyethylene rubber, silicone rubber, neograin rubber, fluoro-iw resin, and PVC graftomer,
19. The waterproof sheet according to item 12, wherein the waterproof coating layer containing the moisture permeable polymer material is 5 to 50.
13. A tarpaulin sheet according to claim 12 having a weight of 0 g/m. 20, the waterproof coating layer containing a moisture-impermeable polymer material is 5 to 5
Claim 1 having a weight of 00, li'/m
The waterproof sheet described in item 2. 21. Claim 12, wherein the water-insoluble water-absorbing substance has the ability to absorb water that is 10 times or more its weight.
Tarpaulin sheet as described in section. 22. Claim 2, wherein the water-insoluble water-absorbing substance has the ability to absorb water 100 times or more its weight.
The waterproof sheet described in item 1. 23. The water-insoluble water-absorbing substance is a pulp-made substance. Cellulose derivative, saponified polyacrylonitrile. Saponified tenone-acrylonitrile graft copolymer 1
Intramolecularly crosslinked acrylic acid alkali metal salt polymer, saponified copolymer of vinyl ester and ethylenically unsaturated carboxylic acid or its ester, saponified copolymer of vinyl ester and acrylic ester, and vinyl alcohol at least one copolymer selected from
The tarpaulin sheet according to claim 12, which comprises seeds. 24. The waterproof sheet according to claim 12, wherein the amount of the water-insoluble water-absorbing substance contained in the fibrous base fabric is within the range of 0.1 to 20097 m2.