CN101636263A - laminated fabric - Google Patents

Abstract

The present invention provides a laminated fabric having air permeability and filtration properties. The laminated fabric is obtained by laminating a protective layer on a holding layer, wherein the protective layer comprises a stretchable nonwoven fabric formed of ultrafine fibers, and the laminated fabric has an air permeability of 2cc/cm²A capture efficiency of 90% or more for 1 μm quartz dust. The laminated fabric may further include a water-resistant layer on the opposite side of the holding layer with the protective layer interposed therebetween.

Description

laminated fabric

This application claims the priority of Japanese Patent Application No. 2007-066496 for which it applied on March 15, 2007, The content is taken in as a part as a part of this application by reference.

technical field

The present invention relates to a laminated fabric that has strength, air permeability, and filterability, and further relates to a laminated fabric that can be easily reduced in volume at low cost.

Background technique

In order to protect the human body from harmful substances such as dust, infectious pathogens, and viruses that are harmful to the human body, or to prevent secondary infection from infectious agents attached to these harmful substances, various protective materials have been used so far . These protective materials require filterability in order to effectively protect against the harmful substances. On the other hand, air permeability is required so that the user does not feel uncomfortable even if the protective material comes into direct contact with the human body. However, filterability and air permeability are opposite properties, so it is difficult to make the two coexist.

For example, Invention Patent Document 1 discloses a composite nonwoven fabric for protective clothing obtained by combining a moisture-permeable and waterproof nonwoven fabric, a porous fabric, and a thermally adhesive nonwoven fabric interposed therebetween. spinning. However, since the composite nonwoven fabric is melted and softened by heat-adhesive nonwoven fabric and made into a thin film, it is composited and integrated with the moisture-permeable and waterproof nonwoven fabric and the porous cloth. air permeability.

Furthermore, disposal of protective materials contaminated with these substances harmful to the human body poses a serious problem. For example, the protective material as mentioned above is usually used as a disposable protective material. After use, it is stored in a plastic bag as a special waste and disposed of by a processing personnel. However, if the protective material is large in size, there will be There is a problem that the transportation cost and disposal cost will be very high, so in recent years, it has been demanded to reduce the cost by reducing the capacity.

Volume reduction methods include depressurizing or compressing the contents of the bag, or heating with dry heat or wet heat to reduce volume, etc. However, depressurization methods are not preferable since they may leak pollutants into the exhaust air.

Although the compression method has been proposed and commercially available is a device for reducing volume by heating and melting contaminated waste into lumps or crushing waste for volume reduction, but the device is very expensive and the scale of the equipment is large, so Not preferred. In addition, the method of volume reduction by dry heat also requires the heat resistance of the bag itself, and as a result, its cost will increase accordingly.

For example, a method and device for volume reduction of infectious medical waste by hot water have been proposed (for example, refer to Patent Document 2). Invention Patent Document 2 is about an infectious medical waste (A) and water (B) composed of a hydrophilic resin that is insoluble in water below 50°C, and the weight of (A)/(B) A mixture with a ratio of 70/30 to 20/80, which is treated at a temperature of 70 to 150° C., so that the infectious medical waste (A) becomes a volume-reduced solid. Infectious medical waste characterized by Although the device is small in size, a special device is required for volume reduction.

Invention Patent Document 1: Japanese Patent Laid-Open No. 2003-336155

Invention Patent Document 2: Japanese Patent Laid-Open No. 2003-073498

Contents of the invention

An object of the present invention is to provide a laminated fabric that can achieve both air permeability and filterability (or capture property).

Another object of the present invention is to provide a laminated fabric which can be integrated without impairing air permeability.

Another object of the present invention is to provide a laminated fabric that maintains filterability even after a load is applied.

Still another object of the present invention is to provide a laminated fabric that does not require special equipment and can be easily reduced in volume at low cost, and a protective material made from it.

The inventors of the present invention have devoted themselves to studying to solve the above-mentioned technical problems. As a result, they have found that by laminating a stretchable nonwoven fabric as a protective layer and a holding layer to form a laminated fabric, both air permeability and filterability can be achieved. Both coexist, and filterability can be maintained even if a load is applied to the laminated fabric.

And, find out as follows: use a kind of at least one layer and soak in the warm water above 60 ℃ that can shrink 5 to 90% of fiber and form as the holding layer the capacity reduction holding layer (A layer), then can not need special Under the conditions of the equipment, the laminated fabric and the protective material made by it can be easily reduced in volume at low cost.

That is, the laminated fabric of the present invention is obtained by laminating a protective layer on the holding layer, and the protective layer includes a stretchable nonwoven fabric formed of ultrafine fibers, and the air permeability of the laminated fabric is 2 cc/ cm ² /sec or more, and the capture efficiency of 1 μm quartz dust is more than 90%.

The aforementioned microfibers can also be made of thermoplastic elastomer, or be, for example, heat-resistant thermoplastic elastomer. Such a thermoplastic elastomer may be, for example, at least one thermoplastic elastomer selected from SEPS, SEBS, urethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and polyamide-based thermoplastic elastomers. The stretchable nonwoven fabric used to constitute the cover layer may have, for example, a tensile elongation at break of 30% or more. In the stretchable nonwoven fabric, the ultrafine fibers are nanofibers having a fiber diameter of 10 to 1,000 nm, and it is preferable that the nanofibers form a nonwoven fabric with a basis weight of 0.01 to 10 g/m ² .

On the other hand, in the retention layer, at least some of the fibers constituting the retention layer may be volume-reducing fibers. For example, such volume-reducing fibers may also be composed of polyvinyl alcohol-based fibers. That is, the present invention includes a laminated fabric that is volume-reduced by warm water. For example, such a volume-reducing laminated fabric can shrink by 5 to 90% by immersion in warm water of 60° C. or higher.

In addition, the laminated fabric of the present invention may further include a water-resistant layer on the opposite side of the holding layer via the protective layer. In this case, the water pressure resistance of the laminated fabric is about 300 to 1,500 mmH ₂ O.

In addition, the present invention includes protective materials comprising the above-mentioned laminated fabric, particularly protective clothing. In addition, if the laminated fabric has volume reducing properties, the present invention also includes a method of putting such a volume reducing laminated fabric in a container, and supplying warm water of 60° C. or higher to the laminated fabric to reduce the volume of the laminated fabric.

The laminated fabric of the present invention can achieve both filterability and air permeability by being composed of a holding layer and a specific protective layer. In particular, since the protective layer is stretchable and has excellent followability to other layers, not only can the integrity of the laminated fabric be improved without compromising the air permeability of the laminated fabric as a whole, but also the air permeability of the laminated fabric can be improved even after a certain load is applied. Maintain filterability of laminated fabrics.

Especially when nanofiber non-woven fabric is used for the protective layer, high air permeability and filterability can be achieved.

In addition, when a volume-reducing material is used for the holding layer, the laminated fabric of the present invention can be easily volume-reduced with warm water after use for transportation or disposal, so transportation costs or disposal costs can be reduced.

Description of drawings

The present invention will be more clearly understood from the description of suitable embodiments with reference to the accompanying drawings. However, the embodiments and drawings are only for illustration and description, and are not intended to limit the scope of the present invention. The scope of the invention is determined by the appended claims. Furthermore, the drawings are not necessarily drawn to scale, but rather are exaggerated to illustrate the principles of the invention. In addition, in the drawings, the same reference numerals in a plurality of drawings represent the same parts.

Fig. 1 is an example of a preferable form of the laminated fabric of the present invention, and is a schematic view showing an apparatus for producing a protective layer of laminated nanofibers.

Fig. 2 is a cross-sectional view showing an example of the structure of the laminated fabric (laminated product) of the present invention.

Detailed ways

The laminated fabric of the present invention is produced by laminating a protective layer on the holding layer, and the protective layer includes a stretchable nonwoven fabric made of ultrafine fibers, and the air permeability of the laminated fabric is 2cc/cm ² /sec above, and the capture efficiency of 1μm quartz dust is above 90%.

〔Hold layer〕

The holding layer is provided to hold the above-mentioned protective layer, as long as a certain air permeability of the entire laminated fabric can be ensured, the holding layer is not particularly limited, and may be a knitted fabric or a non-woven fabric.

The holding layer may be formed of any of natural fibers such as animal fibers and plant fibers and various synthetic fibers depending on the application. These fibers can be used alone or in combination.

Synthetic fibers include, for example: polyvinyl alcohol-based fibers; ethylene-vinyl alcohol-based fibers; polyamide-based fibers (for example, aliphatic polyamide-based fibers such as nylon 6, nylon 66, nylon 46, nylon 610, nylon 11, and nylon 12; Cycloaliphatic polyamide-based fibers, aromatic polyamide-based fibers such as aromatic polyamides, semi-aromatic polyamide-based fibers containing aromatic dicarboxylic acids and aliphatic alkylene diamines); polyolefin-based fibers ( For example, polyethylene-based fibers, polypropylene-based fibers, polypropylene-polyethylene composite fibers); polyester-based fibers (for example, polyethylene terephthalate-based fibers); acrylic fibers (for example, polyacrylonitrile fibers, polymethyl methacrylate fibers, etc.); polyurethane fibers, cellulose fibers (e.g., rayon, acetate fibers); halogen-containing resins (e.g., vinyl chloride-based fibers, vinylidene chloride-based resins , fluorinated vinyl fibers, polyvinylidene fluoride, polyvinylidene fluoride-hexafluoropropylene copolymer); polyimide fibers; polybenzimidazole fibers; polyarylate fibers; polyphenylene sulfide Ether fiber etc.

Among these fibers, polyvinyl alcohol-based fibers, ethylene-vinyl alcohol-based fibers, polyamide-based fibers, polyester-based fibers, and the like are preferable.

The fineness of the fibers used to form the holding layer can be freely set according to the desired texture of the laminated fabric, and is, for example, 0.1 to 1,000 dtex, preferably 1 to 400 dtex. In addition, if the holding layer is a fabric, the warp and weft may have the same or different fineness, but it may also be the warp fineness/weft fineness=10/1 to 1/10, preferably also Available from 5/1 to 1/5.

The weight per unit area of the holding layer can be freely set according to the form of the holding layer, etc., as long as the air permeability and capture properties defined in the present invention can be ensured, there is no special limitation, and it can be, for example, 5 to 100g/m ² , Preference is also given to 10 to 90 g/m ² .

The form of the retaining layer includes woven fabric, nonwoven fabric, woven fabric, synthetic paper, etc., and is not particularly limited as long as the laminated fabric as a whole has specific air permeability and capture properties. The woven fabric, nonwoven fabric, woven fabric, or synthetic paper can be formed by a known or customary method.

Among the forms of these holding layers, it is preferable that the holding layer is a nonwoven fabric from the viewpoint of capturing properties and air permeability.

When using non-woven fabrics to make the retaining layer, there are no special restrictions on the manufacturing method, and it can be applied to spinning bonding method, melt blown method, jet spun cloth method, thermal bonding method, chemical bonding method, air-laid method , acupuncture and other methods.

(capacitance-reducing retaining layer)

Furthermore, in the present invention, from the viewpoint of volume reduction, the holding layer may be a volume reducing holding layer (layer A) made of fibers that shrink by 5 to 90% when soaked in warm water above 60°C. That is, when used in a working environment below 50°C, it can exert a protective function against dust, infectious pathogens, or viruses without shrinking due to moisture such as sweat. That is, a part of the fibers constituting the fabric is shrunk to reduce the volume of the entire fabric.

In the case of having such characteristics, a fiber that does not shrink in water of 50°C or lower is attached to a layer (layer A) formed of fibers that shrink by 5 to 90% when immersed in warm water of 60°C or higher. The laminate obtained in the layer (layer B) has excellent volume reduction properties as will be described later, and the protective fabric and protective clothing produced therefrom.

In the present invention, the entire fabric for volume-reducing protective clothing may be a volume-reducing fiber that shrinks when immersed in warm water, at least a part of the fibers constituting the holding layer.

As such volume-reducing fibers, hydrophilic fibers are preferable, specifically, water-soluble synthetic polymers are preferable, and PVA-based fibers are particularly preferable. Since PVA-based fibers are biodegradable, they are also excellent from the viewpoint of environmental impact at the time of landfill.

The vinyl alcohol-based polymer used to constitute the PVA-based fibers suitable for the layer A of the present invention is not particularly limited, but from the viewpoint of practical mechanical properties, the viscosity-average degree of polymerization is 1,000 or more, and is particularly preferably 1,500 or more, and preferably 5,000 or less from the viewpoint of spinnability and cost. Also, for the same reason, the degree of saponification is preferably 50 mol% or higher, more preferably 65 mol% or higher, and still more preferably 80 mol% or higher.

Vinyl alcohol-based polymers can also be copolymerized with other monomers as components for copolymerization, including, for example, ethylene, vinyl acetate, itaconic acid, vinylamine, acrylamide, trimethylvinyl acetate , maleic anhydride, vinyl compounds containing sulfonic acid, etc.

From the viewpoint of practical mechanical properties, it is preferably a polymer containing 70 mol% or more of vinyl alcohol units with respect to all the constituent units. In addition, the fibers may contain polymers other than vinyl alcohol-based polymers or other additives as long as the effects of the present invention are not impaired. From the viewpoint of fiber performance and the like, the content of the vinyl alcohol-based polymer is preferably 30% by mass/fiber, particularly preferably 50% by mass/fiber.

Next, a method for producing PVA-based fibers suitable for use in the layer A of the present invention will be described. Fibers having excellent mechanical properties can be efficiently obtained by using a spinning dope obtained by dissolving a water-soluble PVA-based polymer in water or an organic solvent and producing fibers by the method described below. Of course, additives or other polymers may be contained in the spinning dope as long as the effects of the present invention are not impaired. As the solvent used to constitute the spinning dope, for example, water; polar solvents such as dimethylsulfoxide (DMSO), dimethylacetamide, dimethylformamide, and N-methylpyrrolidone; glycerin, ethyl alcohol, etc. Polyols such as diols; and mixtures of these solvents and swelling metal salts such as thiocyanate, lithium chloride, calcium chloride, zinc chloride; and mixtures between these solvents; or mixtures of these solvents and water mixture etc. Among these solvents, water or DMSO is preferable from the viewpoints of low-temperature solubility, low toxicity, and low corrosivity.

The polymer concentration in the spinning dope varies depending on the composition, degree of polymerization, and solvent, but is preferably in the range of 8 to 40% by mass. The temperature of the spinning dope at the time of discharge is preferably within a range in which the spinning dope does not undergo gelation or decomposition and coloring, specifically, it is preferably in the range of 50 to 150°C.

These spinning dopes need only be sprayed from nozzles for wet spinning, dry spinning, or dry-wet spinning, and a coagulation liquid having coagulation ability may be sprayed on the PVA polymer. In particular, when the spinning dope is ejected from the holes, the wet spinning method is superior to the dry-wet spinning method from the viewpoint of preventing the fibers from sticking to each other during ejection. In addition, the so-called wet spinning method is a method in which the spinning stock solution is directly ejected from the spinning nozzle into the coagulation bath. In contrast, the so-called dry and wet spinning method is that the spinning stock solution is temporarily ejected from the spinning nozzle into the air. Or inert gas, and then introduce the method of coagulation bath.

The coagulation solution used is different from the case of water when the stock solution solvent is an organic solvent. When using the stock solution of an organic solvent, it is preferable to use a mixed liquid composed of a coagulation liquid and a stock solution solvent from the viewpoint of the obtained fiber strength, and the coagulation liquid is preferably alcohols such as methanol and ethanol, or acetone, Organic solvents such as ketones such as methyl ethyl ketone that have coagulation ability for PVA-based polymers, especially organic solvents containing methanol and DMSO are preferred, and their mixing ratio Preferably it is 55/45 to 80/20. In addition, the temperature of the coagulation liquid is preferably 30°C or lower, more preferably 20°C or lower, and even more preferably 15°C or lower in order to achieve uniform cooling gelation. On the other hand, when the spinning stock solution is an aqueous solution, as the coagulation solvent constituting the coagulation solution, aqueous solutions of inorganic salts such as mirabilite, sodium chloride, and sodium carbonate that have coagulation ability for PVA-based polymers are suitably exemplified. Of course, the coagulation solution may be either acidic or alkaline.

Second, the solvent of the spinning dope is removed by extraction from the coagulated filaments. During extraction, in order to suppress the adhesion between fibers during drying and further improve the strength of the obtained fibers, the strands should be wet-stretched. The wet stretching ratio is preferably 1.5 to 6 times. Extraction is usually carried out through multiple extraction baths. The extraction bath uses the coagulation solution alone, or uses a mixture of the coagulation solution and the stock solution solvent. In addition, the temperature of the extraction bath is in the range of 0 to 80°C.

Next, the filaments are dried to produce PVA-based fibers. What is necessary is just to apply an oil agent etc. as needed at this time, and to dry. The drying temperature is preferably below 210°C, and it is especially preferred to carry out low-temperature drying at below 160°C in the initial stage of drying, and perform multi-stage drying at high temperature in the second half of drying. Furthermore, it is preferable to apply dry heat stretching and, if necessary, dry heat shrinkage to orient and crystallize the PVA molecular chains to increase fiber strength. The reason is that if the strength of the fiber is too low, it can be easily expected that the passability of the process will deteriorate significantly when processing it into a structure such as a nonwoven fabric, for example. In order to improve the mechanical properties of the fiber, it is preferable to perform dry heat stretching at a temperature of 120 to 280°C.

The fineness of the PVA-based fibers obtained by the above-mentioned manufacturing method is not particularly limited, and for example, fibers of 0.1 to 1,000 dtex, preferably 1 to 400 dtex, are widely used. The fineness of the fiber may be appropriately adjusted by the nozzle diameter or the draw ratio. In addition, there is no particular limitation on the fiber length, and it can be arbitrarily selected according to the purpose of use.

In addition, the fibers that shrink by 5 to 90% in warm water of 60°C or higher may be used as a part instead of being used as the whole of the A layer. If fibers that shrink 5 to 90% in warm water above 60°C are used as part of the A layer, the shrinkage rate will be lower than that of the entire A layer made of fibers that shrink 5 to 90% in warm water above 60°C , but by selecting materials or composition ratios, the entire laminate can be shrunk by 5 to 90%.

〔protective layer〕

The protective layer includes a stretchable nonwoven fabric made of microfibers from the viewpoint of particle trapping properties and the like. This stretchable nonwoven fabric substantially maintains the fiber shape of the nonwoven fabric without thinning the laminated fabric from the viewpoint of ensuring air permeability. Therefore, while maintaining a high filtration performance with a capture efficiency of 1 μm quartz dust of over 90%, it can provide high air permeability with an air permeability of 2 cc/cm ² /sec, so that both filterability and air permeability can coexist. In addition, since the protective layer has stretchability, it has good followability with the holding layer or the water-resistant layer described later. , can still suppress the decrease in filterability of the entire laminated fabric.

Microfibers are not particularly limited as long as they can impart stretchability to the nonwoven fabric, but thermoplastic elastomers are often used in general from the viewpoint of elasticity and fiber formability.

Examples of thermoplastic elastomers include styrene-based thermoplastic elastomers, urethane-based thermoplastic elastomers, olefin-based thermoplastic elastomers, vinyl chloride-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and polyamide-based thermoplastic elastomers. body etc. These thermoplastic elastomers may be used alone or in combination. In addition, the aforementioned elastomer may also be a polymer-blended thermoplastic elastomer obtained by blending the resin for constituting synthetic fibers (for example, olefin-based resin, etc.) described in the description of the holding layer, or the like. Furthermore, if necessary, one or more types of organic or inorganic powders may be mixed and used for the elastomer.

The urethane-based thermoplastic elastomer includes a hard segment composed of low-molecular diol and diisocyanate, and a soft segment composed of high-molecular diol and diisocyanate.

As above-mentioned low-molecular-weight diol can enumerate: For example, _C1-10 diols such as ethylene glycol, 1,4-butanediol, 1,6-hexanediol etc.; As above-mentioned high-molecular-weight diol can enumerate: For example, Poly(1,4-butylene adipate), poly(1,6-hexanediol adipate), polycaprolactone, polyethylene glycol, polypropylene glycol, polyoxytetramethylene di Alcohol etc.; Examples of diisocyanates include tolyl diisocyanate, 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and the like.

Examples of styrene-based thermoplastic elastomers include SBS (styrene/butadiene/styrene block copolymer), SIS (styrene/isoprene/styrene block copolymer), SEBS ( Styrene/ethylene/butadiene/styrene block copolymer), SEPS (styrene/ethylene/propylene/styrene block copolymer), etc.

Olefin-based thermoplastic elastomers are composed of polyethylene or polypropylene as the hard segment and SEBS or ethylene/propylene copolymer as the soft segment.

Vinyl chloride-based thermoplastic elastomers are composed of crystalline polyvinyl chloride as the hard segment and amorphous polyvinyl chloride or acrylonitrile as the soft segment.

Polyester-based thermoplastic elastomers are composed of saturated polyester as the hard segment and aliphatic polyether or aliphatic polyester as the soft segment.

Polyamide-based thermoplastic elastomers are composed of polyamide as the hard segment and non-crystalline polyether or polyester with a low glass transition temperature as the soft segment.

Among these thermoplastic elastomers, SEPS, SEBS, urethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, and polyamide-based thermoplastic elastomers are preferable from the viewpoint of heat resistance.

Such a heat-resistant stretchable nonwoven fabric, even when the protective layer and the holding layer are integrated by thermal pressing to laminate the fabric, since the stretchable nonwoven fabric does not substantially become thin, it is not suitable for the laminated fabric. The prescribed breathability is ensured.

In addition, if the holding layer is a volume-reducing holding layer (layer A) that shrinks when exposed to warm water, the protective layer can also be used as a layer (layer B) that does not shrink in water below 50°C and the two can be pasted together. A laminate is formed as a volume-reducing laminated fabric that shrinks when passed through warm water of 60° C. or higher.

In this case, the B layer has no special restrictions on material, weight per unit area, thickness, etc., and can be selected arbitrarily according to the protection object. Water resistance to the extent that it shrinks due to moisture such as sweat.

The average fiber diameter of the ultrafine fibers used to constitute the stretchable nonwoven fabric is, for example, preferably 10 μm or less (for example, about 10 nm to 8 μm), more preferably 5 μm or less, from the viewpoint of achieving both air permeability and filterability. . Such ultrafine fibers can be produced by known methods such as melt blowing.

In particular, the ultrafine fibers may be nanofibers having an average fiber diameter of 10 to 1,000 nm (preferably 15 to 800 nm, more preferably 25 to 600 nm) from the viewpoint of improving air permeability and protective properties.

Regarding the above-mentioned balance between protection and air permeability, although the key is how to capture harmful particles with less pressure loss, nanofibers have low pressure loss during filtration due to the slip flow effect and are breathable. It is characterized by high performance, so it is suitable for use as a product that can coexist with both protection and breathability (Takeyuki Kawaguchi, "Nanofa Iba-Technoroji One をたた高発智発流展" (Edited by Tatsuya Motomiya), No. 10 Chapter, p. 373).

In addition, the so-called fiber diameter in the present invention refers to the diameter of the fiber cross-section obtained from the electron micrograph of the fiber assembly obtained by photographing at 5,000 magnifications, and the average obtained by randomly sampling 50 fibers and measuring the fiber diameter. value.

The weight per unit area of the stretchable non-woven fabric can fully realize the gas permeability and capture property specified in the present invention, and there is no special limitation. The weight per unit area of the non-woven fabric can also be based on the average fiber diameter of the superfine fiber size varies.

For example, when the average fiber diameter of the ultrafine fibers exceeds 1 μm, the basis weight of the nonwoven fabric is preferably 1 to 20 g/m ² , more preferably 5 to 15 g/m ² .

In addition, for example, when the average fiber diameter of the ultrafine fibers is 1 μm or less, the weight per unit area of the nonwoven fabric is preferably 0.01 to 10 g/m ² , more preferably 0.03 to 8 g/m ² , and still more preferably 0.05 to 8 g/m 2 . 6g/m ² .

If the weight per unit area based on the average fiber diameter is too much, although the protective performance against the passage of fine dust harmful to the human body such as asbestos can be improved, the air permeability will be lower than 2cc/cm ² /sec as mentioned above. Case. In the case of nanofibers in particular, an increase in the ratio of nanofibers involves an increase in cost, which is not preferable. On the contrary, if the amount of weight per unit area is too small, although the air permeability is good, it is difficult to uniformly distribute it in the entire holding layer, and as a result, the capture efficiency of 1 μm quartz dust may be lower than 90%. Therefore, Not preferred.

Since the protective layer is composed of a stretchable nonwoven fabric, the tensile elongation at break can be increased compared with that of a nonstretchable nonwoven fabric. For example, when measuring a strip-shaped test piece with a width of 15 mm according to JIS P8113, the tensile elongation at break of the stretchable nonwoven fabric may be, for example, 30% or more (for example, 30 to 200%), preferably 35 to 180%.

The stretchable nonwoven fabric can be produced by using ultrafine fibers according to the production method of the nonwoven fabric described above in the description of the holding layer. In addition, especially when the ultrafine fibers are nanofibers, a nonwoven fabric formed of nanofibers can also be produced by the method described below.

First, the aforementioned nanofibers can be produced using, for example, the following method. As the polymer stock solution, any one of a solution obtained by dissolving in a polymer-soluble solvent, a molten stock solution obtained by heating and melting, and the like can be appropriately selected. Next, using these spinning dopes, the nanofiber layer was laminated or composited as the above-mentioned B layer by electrospinning. The electrospinning method includes a method of depositing nanofibers on a grounded counter electrode side by applying a high voltage to a conductive member capable of supplying a spinning dope. In this way, the spinning stock solution discharged by the stock solution supply part is charged and split, and then the fibers are continuously pulled out from a point of the droplet by the electric field, and the split fibers are mostly diffused and accumulated in a few centimeters away from the stock solution supply part. to capture belts or flakes of tens of centimeters. A dense sheet can be obtained by preventing the movement of the fibers in a microglued state simultaneously with the accumulation, and by successively accumulating new fine fibers.

That is, in FIG. 1 , the spinning dope in which the polymer is dissolved is metered and fed by a quantitative pump 1 , distributed by a distribution rectifying device 2 so that the pressure and liquid volume are uniform, and delivered to the spinning nozzle 3 . A hollow needle-shaped spinneret 4 protruding from each hole is attached to the spinneret part 3 , and electrical insulation part 5 prevents electricity from leaking to the whole spinneret part 3 . The protruding spinning nozzles 4 made of conductive materials are installed in a number of rows at right angles to the direction of travel of the sheet-forming pulling device 7 formed by an endless conveyor and vertically downward, and an output terminal of a DC high voltage generating power supply is connected to On the protruding spinning nozzles 4, each protruding spinning nozzle 4 can apply direct current high-voltage electricity through wires. In the endless conveyor forming the sheet pulling device 7 is installed a conductive member 8 already grounded to neutralize the applied potential. The spinning dope sent to the protruding spinning nozzle 4 by the pressure of the spinning nozzle part 3 is charged and split, and then is continuously pulled out from a point of the droplet by the electric field, and the split fibers are mostly diffused and accumulated in the sheet-forming pulling device installed 7. On the upper conductive part, and carry out micro-adhesion, and move through the sheet and the pulling device, and at the same time as it moves, it is accumulated by the microfibers protruding from the next spinning nozzle, and the accumulation is repeated one after another to form a dense and uniform Flakes.

〔layered cloth〕

The laminated fabric is constructed by laminating a protective layer on a holding layer. There is no particular limitation on the method of attaching the retaining layer and the protective layer to form a laminate. For example, when a nonwoven fabric is used, any method such as thermal bonding, chemical bonding, needle punching, or hydrospraying can be applied. In addition, a measure of coating the protective layer on the holding layer by spunbonding, melt blowing, electrospinning, etc. can be suitably used without any problem.

In addition, when there is no affinity between the maintenance layer and the protective layer, an adhesive layer having affinity for the two components (for example, for adhesion using an adhesive or for adhesion by fusion) may be inserted between the layers. desired layer). For example, in the case where a thermally-adhesive adhesive layer is provided, the difference between the softening point (T _B ) of the fibers used to form the stretchable nonwoven fabric (protective layer) and the softening point ( _TH ) of the thermally-adhesive adhesive layer The relationship may be T _H < T _B , preferably _TH +5 ≤ T _B , more preferably _TH + 10 ≤ T _B .

In addition, in the present invention, in order to improve the water resistance of the laminated fabric, the protective layer may be an intermediate layer and a water-resistant layer may be further laminated on the opposite side of the holding layer. By laminating the water-resistant layer, even when the laminated fabric is used under high humidity or in an environment where moisture easily adheres, it is possible to prevent the decrease in air permeability and capture properties of the protective layer due to moisture adhesion.

For example, a moisture-permeable waterproof nonwoven fabric can be used for the water-resistant layer. Although the moisture-permeable and waterproof non-woven fabric can also be formed by applying water-repellent or water-repellent coating to the non-woven fabric formed of various fibers as described in the description of the holding layer, it can be formed from ensuring From the viewpoint of air permeability of the protective layer, it is preferably formed of hydrophobic fibers. Examples of the hydrophobic fibers include polyolefin-based fibers and polyester-based fibers already described in the description of the holding layer, preferably polyolefin-based fibers. As the lamination method of the water-resistant layer, any of the methods described in the lamination method of the holding layer and the protective layer can be used. The weight per unit area of the water-resistant layer is, for example, 5 to 50 g/m ² , preferably 10 to 45 g/m ² from the viewpoint of imparting water resistance.

In addition, in the laminated fabric, the total weight per unit area of the holding layer, the protective layer (and the water-resistant layer if necessary) can also be freely set depending on the characteristics of the holding layer and/or the protective layer, for example, 30 to 100g/ m ² is preferably 40 to 90 g/m ² .

Especially when the holding layer has capacity reducing properties, the thickness of the protective layer (and the water-resistant layer if necessary) may be equal to or equal to the thickness of the holding layer from the viewpoint of shrinking the laminated fabric as a whole. 2 times or less, preferably 1.5 times or less.

In addition, if necessary, a film may be bonded to a part of the holding layer and used. In this case, the bonding method of the fiber and the film is not particularly limited, and bonding with an adhesive or bonding with heat fusion can be applied.

In addition, various post-treatments may be performed as necessary so that the flakes produced above can be suitable for various uses. For example, calendering treatment for densification or hydrophilic treatment, hydrophobic treatment, surfactant attachment treatment, etc. may be performed.

Furthermore, the fabric for protective clothing of the present invention is more preferably subjected to electret processing. The so-called electret refers to a substance that can semi-permanently maintain electric polarization even if there is no external electric field and can form an electric field around it. It can be made of easily charged materials such as polypropylene.

By applying electret processing, the electrostatic capture function can be additionally utilized, so the particle capture efficiency can be dramatically improved without changing the air permeability. As for the electret processing method, including: thermal electret, electro-electret, photo-electret, radiation electret, magneto-electret, mechanical electret, involving a variety of methods, but There is no particular limitation, and either one can be applied.

From the viewpoint of protection, the laminated fabric produced as described above preferably has a capture efficiency of 1 μm quartz dust of 90% or higher, more preferably 93% or higher, and still more preferably 96% or higher.

Dust harmful to the human body, infectious pathogens, and viruses have various particle sizes. Representative harmful dust asbestos is composed of aggregates of fibers with a length of several microns to tens of microns. In addition, bacteria or fungi that constitute infectious pathogens are mainly It is 2 to 3 μm, and the virus alone is 0.01 to 0.1 μm, but the actual infection path is mainly from the droplet infection caused by the patient's cough, etc. Since this droplet is almost 2 μm or more, so as long as the capture efficiency of 1 μm quartz dust is When more than 90% can be captured, then it can be considered that most of these dusts, infectious pathogens, viruses and the like can be completely protected.

On the other hand, if the capture efficiency of 1 μm quartz dust is less than 90%, it is not preferable in terms of the above-mentioned protective properties.

The laminated fabric of the present invention has an air permeability of 2 cc/cm ² /sec or more in order to ensure comfort to the human body. If the air permeability is less than 2cc/ ^cm2 /sec, it is not preferable because it is easy to get wet, but it is preferably 3cc/ ^cm2 /sec or more, more preferably 3.5cc/ ^cm2 /sec or more and 10cc/ ^cm2 /sec or less . The above-mentioned relationship between the capture efficiency of 1 μm quartz dust and the air permeability, in general, once the protection is improved, the air permeability will be reduced, and the evaporation will be deteriorated. As a result, the use characteristics, that is, the comfort when wearing will be reduced. Therefore, it is preferable to make both protectiveness and air permeability coexist within the above-mentioned performance range.

In the present invention, since the stretchable nonwoven fabric is used for the cover layer, the followability between the cover layer and other layers, that is, the holding layer or the cover layer is good. Therefore, even after a certain load is applied, the integrity of the entire laminated fabric can be easily maintained to prevent filterability from deteriorating. The laminated fabric of the present invention has a capture efficiency of 1 μm quartz dust of 90% or more (preferably 93% or more, more preferably 95% or more) after washing five times and drying the laminated fabric according to the JIS L1096 B.23.1A method, for example. .

When the laminated fabric has water resistance, the laminated fabric may have a water pressure resistance of 300 to 1,500 mmH ₂ O, or 400 to 1,000 mmH ₂ O, as measured by the low water pressure method according to JIS L1092, for example. If the water pressure resistance is too low, the protective layer will not easily function as a moisture protector, and if the water pressure resistance is too high, the air permeability of the laminated fabric as a whole may not satisfy a predetermined value.

In addition, if the laminated fabric has capacity-reducing properties, the capacity-reducing laminated fabric can shrink by 5 to 90% in warm water above 60°C (for example, above 60°C and below 70°C), and can be removed from the disposal space. From a viewpoint, the shrinkage is preferably 10 to 92%, more preferably 20 to 94%. In particular, the laminated fabric can shrink by 30 to 95%, preferably 40 to 90%, even in warm water of 70°C or higher (for example, 70°C or higher and lower than 80°C) from the viewpoint of improving shrinkability.

In addition, the shrinkage rate here represents the value calculated by the method of [the shrinkage rate % of the fabric in warm water] mentioned later.

[Volume reduction method of volume-reducing laminated fabrics]

If the laminated fabric of the present invention has volume reduction properties, volume reduction can be easily achieved at low cost without requiring special equipment.

For example, putting a volume-reducing laminated fabric (and a protective material made of the fabric) in various containers (for example, plastic containers, plastic bags), and supplying warm water above 60°C to the laminated fabric can achieve Volume reduction of laminated fabrics. The method of supplying the warm water is not particularly limited, and the container may be filled with warm water in advance, or the water may be heated to a predetermined temperature after filling the closed container with water.

For example, any heating method can be used as long as it can heat the water temperature in the container to 60°C or higher, and it is suitable to use a method of supplying hot air from the outside of the container, a method of immersing the container itself in hot water, or using a microwave oven, etc. A method of heating water inside a container with an electric heating device, etc.

The ratio of warm water to the laminated fabric is not particularly limited as long as it can reduce the volume of the laminated fabric, for example, it may be 200 parts by mass or more (for example, 250 to 500 parts by mass) of warm water relative to 100 parts by mass of the laminated fabric, preferably It is 300 mass parts or more (for example, 350 to 450 mass parts) of warm water.

For volume reduction containers, when using a plastic bag, place 200 parts by mass or more of water with respect to 100 parts by mass of the laminated fabric at the same time, seal it tightly, and then heat it from the outside of the bag, or heat it with a microwave oven, etc. The device heats from the inside of the bag, thereby reducing the volume of protective clothing. Here, the plastic bag is not particularly limited as long as it can ensure water resistance and moisture resistance so that water does not leak out, and does not melt and decompose at the use temperature.

In addition, the sealing method is not particularly limited, and a method of binding the bag itself, a method of closing the opening of the bag with a clip, heat sealing, and the like are suitably used.

Protective clothing made of volume-reducing laminated fabrics can be transported or disposed of after use after volume reduction, thereby reducing transport costs or disposal costs.

Example

Hereinafter, the present invention will be described in more detail with examples and comparative examples, but the present invention is not limited thereto.

[Shrinkage % of fabric in warm water]

The cloth was cut into 10 cm×10 cm, and immersed in warm water for 2 minutes in a free state. After dipping, take out the fabric and shake off the liquid gently, measure the longitudinal (X) and transverse (Y) dimensions (cm) of the fabric, and calculate the shrinkage rate with the following formula:

Shrinkage (%)={[(10-X)/10]+[(10-Y)/10]}/2×100.

〔Dust capture efficiency%〕

According to the JIS T8151 dust cover test method, the dust capture efficiency was measured with "Mask Tester AP-6310FP" manufactured by Shibata Science. The dust was measured using 1 μm quartz dust under the condition that the measurement wind speed was 8.6 cm/min.

In addition, according to the JIS L1096 B.23.1A method, the dust capture efficiency was also measured in the same manner as above for the samples obtained by washing five times and then drying.

〔Air permeability cc/cm ² /sec〕

Measured with a Fraser fabric air permeability tester (manufactured by Toyo Seiki Co., Ltd.).

〔Tensile elongation at break of protective layer%〕

The measurement was performed on a strip-shaped test piece having a width of 1.5 cm according to the JIS P8113 test method.

〔Tensile strength N/5cm〕

The measurement was performed on a strip-shaped test piece having a width of 5 cm according to the JIS L1906 test method.

[Example 1]

(1) Use a crimped PVA fiber with a polymer polymerization degree of 1,750, a saponification degree of 98.5 mol%, a monofilament fineness of 2.2 dtex, a fiber length of 51 mm, and a strength of 5 cN/dtex (manufactured by Kuraray Co., Ltd. "WN7"; the shrinkage rate in warm water at 60°C is 6%, the shrinkage rate in warm water at 70°C is 65%, and the melting temperature is 75°C). m ² of random fiber web.

(2) In addition, a 10% aqueous solution consisting of PVA with a polymer polymerization degree of 1,750 and a saponification degree of 98.5 mol % is prepared, and a commercially available foaming machine is used to produce a foam, and the foam is placed in a The fiber net obtained in the above item (1) is uniformly applied to the fiber net by rolling liquid, and then dried to make a non-woven fabric, thereby producing a non-woven fabric according to the so-called foam bonding treatment. cloth. The nonwoven fabric produced as described above was used as the holding layer. In addition, the shrinkage rate of the holding layer was 15% in 60°C warm water and 70% in 70°C warm water.

(3) On the other hand, the protective layer and the water-resistant layer were manufactured as follows.

By melt-kneading SEPTON ("SEPTON 2002" manufactured by Kuraray Co., Ltd.) and polypropylene ("NOVATEC-PP" manufactured by Japan Polychem Corporation) at a ratio of 60/40 (weight ratio), and melt-blown The SEPTON/polypropylene blended non-woven fabric with a weight per unit area of 10 g/m ² was laminated as a protective layer.

Also, a nonwoven fabric having a weight per unit area of 20 g/m ² produced by using polypropylene ("NOVATEC-PP" manufactured by Japan Polychem Corporation) using a melt-blown method was used as the water-resistant layer.

(4) Next, superimpose the above-mentioned holding layer, protective layer and water-resistant layer in this order, and process the superimposed ones by calendering (calendering conditions: temperature 130°C, contact pressure 0.1MPa, processing speed 5m/min) are bonded together to manufacture a laminate having a cross-sectional structure as shown in FIG. 2 . In addition, in FIG. 2, A represents the holding layer, B represents the protective layer, and C represents the water-resistant layer.

(5) Table 1 shows the properties of the fabric including the laminate obtained by the method of item (4). The weight per unit area of the fabric obtained above was 65 g/m ² , the tensile strength was 120 N/5 cm×100 N/5 em (MD direction×CD direction), the air permeability was 2.1 cc/cm ² /sec, and 1 μm quartz dust The capture efficiency is 97.3%, and the capture efficiency of 1 μm quartz dust after washing five times is 97.1%. It not only has the air permeability and filterability that laminated fabrics should have, but also has excellent integrity, and even after the load of washing is applied. Filterability can be maintained. Therefore, this laminated fabric has sufficient performance that a fabric for protective clothing should have. In addition, the fabric shrank by 12% when immersed in warm water at 60°C, and shrank by 61% when immersed in warm water at 70°C.

[Example 2]

(1) Use a crimped PVA fiber with a polymer polymerization degree of 1,750, a saponification degree of 98.5 mol%, a monofilament fineness of 2.2 dtex, a fiber length of 51 mm, and a strength of 5 cN/dtex (manufactured by Kuraray Co., Ltd. "WN7" of 100 parts by mass of the fiber) to produce an unoriented fiber web having a weight per unit area of 35 g/m ² composed of 100 parts by mass of the fiber, and then embossing treatment was applied to obtain an embossed nonwoven fabric. The embossing conditions were an adhesion area ratio of 12%, a temperature of 180° C., a linear pressure of 40 kgf/cm, and a processing speed of 15 m/min. This non-woven fabric is used as a holding layer.

(2) On the other hand, the protective layer and the water-resistant layer were produced as follows.

Put polyurethane ("KURAMIRON 1190-000" manufactured by Kuraray Co., Ltd.) into dimethylformamide (DMF) to make it 10% by mass, stir and dissolve at 90°C, and cool the completely dissolved mixture to room temperature or lower. Prepare spinning dope. Electrospinning was performed with the spinning device shown in FIG. 1 using the obtained spinning dope. For the spinning nozzle 4, a needle with an inner diameter of 0.9 mm was used. In addition, the distance between the spinning nozzle 4 and the forming sheet pulling device 7 was set to 12 cm. In addition, in the forming sheet pulling device 7, the same polypropylene as in Example 1 ("NOVATEC-PP" manufactured by Japan Polychem Corporation) was preliminarily wrapped with the same polypropylene ("NOVATEC-PP" manufactured by Japan Polychem Corporation) with a weight per unit area of 20 g/m. ² Polypropylene non-woven fabric (water-resistant layer).

Next, at a conveyor speed of 0.1 m/min, the dope is extruded from the spinneret at a prescribed supply rate, and an applied voltage of 25 kV is supplied to the spinneret to wind the dope on the water-resistant layer wound on the sheet-forming pulling device 7. Polyurethane nanofibers of 1.0 g/m ² were laminated.

(3) The holding layer of (1) above was combined with the protective layer and water-resistant layer of (2) above so that the protective layer was used as an intermediate layer, and calendering was performed in the same manner as in Example 1 to produce a laminate.

(4) As shown in Table 1, the fabric composed of the laminate has a basis weight of 56 g/m ² , a tensile strength of 64 N/5 cm×54 N/5 cm (MD direction×CD direction), and an air permeability of 5.7 cc/cm ² /sec, 1μm quartz dust capture efficiency is 99.9%, and 1μm quartz dust capture efficiency after washing five times is 99.8%, which not only has both air permeability and filterability that laminated fabrics should have, but also has excellent integrity , and filterability is maintained even after the load of washing is applied. Therefore, this laminated fabric has sufficient performance that a fabric for protective clothing should have. In addition, when this fabric was immersed in warm water at 60°C, it shrank by 11%, and when it was immersed in warm water at 70°C, it shrank by 58%.

[Example 3]

(1) Use a crimped PVA fiber with a polymer polymerization degree of 1,750, a saponification degree of 98.5 mol%, a monofilament fineness of 2.2 dtex, a fiber length of 51 mm, and a strength of 5 cN/dtex (manufactured by Kuraray Co., Ltd. "WN7"; the shrinkage rate in 60°C warm water is 6%, the shrinkage rate in 70°C warm water is 65%, and the melting temperature is 75°C) to manufacture 100 parts by mass of this fiber. The weight per unit area is 35g /m ² of random fiber web.

(2) In addition, prepare a 10% aqueous solution composed of PVA with a polymer polymerization degree of 1,750 and a saponification degree of 98.5 mol%, and then produce a foam with a commercially available foam machine, and place the foam on A nonwoven fabric is produced by a so-called foam bonding process in which the fiber web prepared in (1) above is squeezed with a roll to uniformly apply the PVA resin to the fiber web, and then dried to form a nonwoven fabric. The nonwoven fabric produced above was used as a holding layer. In addition, the shrinkage rate of the holding layer was 15% in 60°C warm water and 70% in 70°C warm water.

(3) The water-resistant layer is a polypropylene nonwoven fabric with a weight per unit area of 20 g/m ² (water-resistant layer).

(4) Next, while moving the above-mentioned holding layer at a conveyor linear speed of 50 m/min, the melted coating is uniformly coated at a coating amount of 2 g/m ² at a nozzle temperature of 190° C. and a hot air temperature of 205° C. A hot-melt resin ("Instantrock MP801" manufactured by NSC Co., Ltd.; softening point: about 140° C.) was taken up with a take-up roll after being temporarily cooled. In addition, also for the above-mentioned water-resistant layer, a hot-melt resin was applied in a coating amount of 2 g/m ² in the same manner as the holding layer.

(5) On the other hand, the protective layer was produced as follows.

Add SEPTON ("SEPTON 2002" manufactured by Kuraray Co., Ltd.; softening point: about 150°C) to 10% by mass in DMF, stir and dissolve at 90°C, and cool the completely dissolved mixture to room temperature to obtain spinning stock solution. Electrospinning was performed with the spinning device shown in FIG. 1 using the obtained spinning dope. For the spinning nozzle 4, a needle with an inner diameter of 0.9 mm was used. In addition, the distance between the spinning nozzle 4 and the forming sheet pulling device 7 was set to 10 cm. Further, in forming the sheet pulling device 7, the holding layer to be coated with the hot-melt resin obtained in (4) above is wound so that the sprayed surface of the fiber is on the hot-melt resin side.

Next, at a conveyor speed of 0.1 m/min, the dope is extruded from the nozzle at a specified supply amount, and an applied voltage of 20 kV is supplied to the nozzle, and 1.0 g/m ² of SEPTON is laminated on the nonwoven fabric layer. Nanofibers.

(6) In addition, the holding layer of the laminated SEPTON nanofiber layer is overlapped with the water-resistant layer of the hot-melt resin coated with the above (4), so that the hot-melt resin side of the water-resistant layer is in contact with the SEPTON nanofiber layer. Next, The laminates were laminated by calendering (calendering conditions: temperature: 140° C., contact pressure: 0.1 MPa, processing speed: 5 m/s). The fabric composed of this laminate, as shown in Table 1, has a basis weight of 60 g/m ² , a tensile strength of 93 N/5 cm×49 N/5 cm (MD direction×CD direction), and an air permeability of 8.1 cc/m 2 . em ² /second, 1μm quartz dust capture efficiency is 99.7%, and after washing five times, the capture efficiency of 1μm quartz dust is 99.7%. Filterability is maintained even after a load of washing is applied. Therefore, this laminated fabric has sufficient performance that a fabric for protective clothing should have. In addition, when this fabric was immersed in warm water at 60°C, it shrank by 12%, and when it was immersed in warm water at 70°C, it shrank by 64%.

[Example 4]

(1) A nylon spunbonded nonwoven fabric ("ELTAS N01030" manufactured by Asahi Kasei Co., Ltd.) having a basis weight of 30 g/m ² was used as a holding layer.

(2) The same polypropylene as in Example 1 ("NOVATEC-PP" manufactured by Japan Polychem Corporation) was used as a water-resistant layer using a polypropylene nonwoven fabric with a weight per unit area of 20 g/m ² produced by a melt blown method.

(3) Next, while moving the above-mentioned holding layer at a conveyor line speed of 50 m/min, at a nozzle temperature of 190°C and a hot air temperature of 205°C, evenly coat and melt it with a coating amount of 2g/ ^m2 A hot-melt resin ("Instantrock MP801" manufactured by NSC Co., Ltd., Japan), after that, it was temporarily cooled, and then wound up with a take-up roll. In addition, also for the above-mentioned water-resistant layer, a hot-melt resin was applied in the same manner as the holding layer.

(4) On the other hand, the protective layer was produced as follows.

Polyurethane ("KURAMIRON 1190-000" manufactured by Kuraray Co., Ltd.) was added to dimethylformamide (DMF) to make it 10% by mass, stirred and dissolved at 90°C, and the completely dissolved mixture was cooled to room temperature or lower. Prepare spinning dope. Electrospinning was performed with the spinning device shown in FIG. 1 using the obtained spinning dope. For the spinning nozzle 4, a needle with an inner diameter of 0.9 mm was used. In addition, the distance between the spinning nozzle 4 and the forming sheet pulling device 7 was set to 12 cm. Further, in forming the sheet pulling device 7, the holding layer coated with the hot-melt resin obtained in (3) above is wound so that the sprayed surface of the fiber is on the hot-melt resin side.

Next, at a conveyor speed of 0.1m/min, the dope is extruded from the nozzle at a specified supply amount, and an applied voltage of 25kV is supplied to the nozzle, and 1.0g/ ^m2 of polyurethane is laminated on the nonwoven fabric layer. Nanofibers.

(5) In addition, the holding layer of the laminated polyurethane nanofiber layer is overlapped with the water-resistant layer coated with the hot-melt resin of (3) above, so that the hot-melt resin side of the water-resistant layer is in contact with the polyurethane nanofiber layer. Next, The laminates were bonded by calendering (calendering conditions: temperature: 140° C., contact pressure: 0.1 MPa, processing speed: 5 m/s). The fabric composed of this laminate, as shown in Table 1, had a basis weight of 55 g/m ² , a tensile strength of 105 N/5 cm×71 N/5 cm (MD direction×CD direction), and an air permeability of 8.4 cc/cm ² /sec, 1μm quartz dust capture efficiency is 99.9%, and 1μm quartz dust capture efficiency after washing five times is 99.8%. Filterability is maintained even after a load of washing is applied. Therefore, this laminated fabric has sufficient performance that a fabric for protective clothing should have.

[Example 5]

In addition to replacing the PVA non-woven fabric with foam bonding treatment used in the retention layer of Example 3, the polyethylene terephthalate spun-bonded non-woven fabric with a unit area weight of 30 g/m ² Cloth ("ELTAS E01030" manufactured by Asahi Kasei Co., Ltd.) was used as a holding layer, and the cloth was produced in the same manner as in Example 3. As shown in Table 1, the fabric has a weight per unit area of 55 g/m ² , a tensile strength of 124 N/5 cm×77 N/5 cm (MD direction×CD direction), an air permeability of 9.1 cc/cm ² /sec, and 1 μm quartz dust. The capture efficiency is 99.6%, and the capture efficiency of 1μm quartz dust after washing five times is 99.5%. It not only has the air permeability and filterability that laminated fabrics should have, but also has excellent integrity, even after the load of washing is applied. Maintain filterability.

[Comparative Example 1]

The nylon non-woven fabric (retaining layer) and polypropylene non-woven fabric (water-resistant layer) coated with the hot-melt resin obtained in (3) of Example 4 were used without interposing the protective layer. After the respective hot-melt resin sides were superimposed, they were laminated by calendering in the same manner as in Example 4 to manufacture a fabric. As shown in Table 1, the fabric has a weight per unit area of 54 g/m ² , a tensile strength of 101 N/5 cm × 70 N/5 cm (MD direction × CD direction), an air permeability of 21 cc/cm ² /sec, and 1 μm quartz dust. The capture efficiency was 33.1%, and the capture efficiency of 1 μm quartz dust after washing five times was 32.8%, showing poor filterability.

[Comparative Example 2]

(1) A nylon spunbonded nonwoven fabric ("ELTAS N01030" manufactured by Asahi Kasei Co., Ltd.) having a basis weight of 30 g/m ² was used as a holding layer.

(2) A non-woven fabric (water-resistant layer) with a weight per unit area of 20 g/m ² obtained by melt-blowing the same polypropylene as in Example 1 ("NOVATEC-PP" manufactured by Japan Polychem Corporation) as a water-resistant layer.

(3) Next, while moving the above-mentioned holding layer at a conveyor linear speed of 50 m/min, the melted coating is uniformly coated at a coating amount of 2 g/m ² at a nozzle temperature of 190°C and a hot air temperature of 205°C. Hot-melt resin ("Instantrock MP801" manufactured by NSC Co., Ltd., Japan), and after that, it was temporarily cooled and wound up with a take-up roll. In addition, a hot-melt resin was applied to the above-mentioned water-resistant layer in the same manner as the holding layer.

(4) On the other hand, the protective layer was manufactured as described below.

Polyacrylonitrile (manufactured by Sigma-Aldrich Japan Corp., weight-average molecular weight: 150,000) was added to dimethylformamide (DMF) to make it 11% by mass, stirred and dissolved at 90°C, and the completely dissolved mixture Cool to normal temperature to obtain spinning dope. Electrospinning was performed with the spinning device shown in FIG. 1 using the obtained spinning dope. For the spinning nozzle 4, a needle with an inner diameter of 0.9 mm was used. In addition, the distance between the spinning nozzle 4 and the forming sheet pulling device 7 was set to 10 cm. Further, winding in the forming sheet take-up device 7, the holding layer of the hot-melt resin obtained in (3) above was coated so that the sprayed surface of the fiber was on the hot-melt resin side.

Then, at a conveyor speed of 0.1 m/min, the dope was extruded from the nozzle at a specified supply amount, and an applied voltage of 18 kV was supplied to the nozzle, and 1.0 g/m ² of poly Acrylonitrile nanofibers.

(5) In addition, the water-resistant layer obtained by applying the hot-melt resin of the above (3) to the holding layer laminated with the polyacrylonitrile nanofiber layer is superimposed, so that the hot-melt resin side of the water-resistant layer is in contact with the acrylonitrile nanofiber layer. Then, they were laminated together by calendering (calendering conditions: temperature: 140° C., contact pressure: 0.1 MPa, processing speed: 5 m/s) to manufacture a laminate. The fabric composed of this laminate, as shown in Table 1, has a basis weight of 55 g/m ² , a tensile strength of 104 N/5 cm×70 N/5 cm (MD direction×CD direction), and an air permeability of 7.5 cc/m 2 . cm ² /sec, 1μm quartz dust capture efficiency is 99.6%, and 1μm quartz dust capture efficiency after washing five times is 84.1%. After washing, the proper integrity of non-woven fabric is lost, and filterability cannot be maintained.

[Comparative Example 3]

As a comparison, the performance of DuPont's "work protective clothing" (weight per unit area: 41g/m ² ), which has been used as a base material for protection until now, was evaluated. As shown in Table 1, the tensile strength was 80N /5cm×94N/5cm (MD direction×CD direction), the capture efficiency of 1μm quartz dust is as high as 98.5%, but the air permeability is very low at 0.4cc/cm ² /sec. In addition, in 60℃ and 70℃ warm water Can't shrink at all.

Industrial Applicability

The laminated fabric of the present invention is suitable as a protective material for protecting the human body from harmful substances such as dust harmful to the human body, infectious pathogens, viruses, or various floating substances in the atmosphere. This kind of protective material is not only protective clothing (such as protective clothing, masks, gloves, hats, etc.), but also can be used in the environment where the above-mentioned harmful substances are attached, that is, it includes protective clothing to protect the human body from secondary infection of harmful substances. Sheets, protective clothing, filters, etc. used for the purpose.

In addition, if the laminated fabric has volume reduction properties, the volume of the laminated fabric (or protective material) can be reduced for transportation or disposal, thereby reducing transportation costs or disposal costs.

Claims (12)

1. laminated fabric, it is by the applying overcoat makes on the layer keeping, and this overcoat comprises with the formed flexible nonwoven fabrics of superfine fibre, and the air permeability of this laminated fabric is 2cc/cm simultaneously ²More than/the sec, and the capture rate of 1 μ m silica dust is more than 90%.

2. laminated fabric as claimed in claim 1, wherein this superfine fibre is made of thermoplastic elastomer (TPE).

3. laminated fabric as claimed in claim 2, wherein this thermoplastic elastomer (TPE) is made of at least a thermoplastic elastomer (TPE) that is selected from SEPS, SEBS, carbamate based thermoplastic elastomer, polyester based thermoplastic elastomer and the polyamide-based thermoplastic elastomer (TPE).

4. laminated fabric as claimed in claim 1, wherein the tension failure percentage elongation of flexible nonwoven fabrics is more than 30%.

5. laminated fabric as claimed in claim 1, in this flexible nonwoven fabrics, this superfine fibre is that fiber directly is 10 to 1, the nanofiber of 000nm, and this nanofiber to form weight per unit area be 0.01 to 10g/m ²Nonwoven.

6. laminated fabric as claimed in claim 1 wherein is used for constituting at least a portion of the fiber that keeps layer for subtracting the capacitive fiber.

7. laminated fabric as claimed in claim 6, wherein this subtracts the capacitive fiber and is made of vinylal fibre.

8. laminated fabric as claimed in claim 1, it further possesses water-resistant layer at the opposition side that keeps layer across overcoat.

9. laminated fabric as claimed in claim 8, its water pressure resistance are 300 to 1,500mmH ₂O.

10. laminated fabric as claimed in claim 1, it shrinks 5 to 90% by the warm water that impregnated in more than 60 ℃.

11. a protection material, its at least a portion is obtained by the described laminated fabric of claim 1.

12. a laminated fabric subtracts the method for appearanceization, be the described laminated fabric of claim 1 is put into closed container, and to the warm water of this laminated fabric supply more than 60 ℃ so that laminated fabric subtracts appearanceization.

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