JPWO2014208605A1 - Dust-proof material and protective clothing using the same - Google Patents

Abstract

The present invention has a laminated structure of a fiber layer and an electret nonwoven layer, has a laminated structure of a fiber layer and an electret nonwoven layer, the sum of the numbers of the fiber layer and the electret nonwoven layer is 2 or more, and adjacent fiber layers And an electret non-woven fabric layer are bonded in a region having an area of 50% or less. The present invention provides a dust-proof material and protective clothing that have both high dust-proof properties that do not allow dust to enter the clothing and high air permeability that allows comfortable work, and that prevent the temperature in the protective clothing from rising in summer.

Description

  The present invention relates to a dustproof material for protecting a human body from dust released into the environment, and protective clothing using the same.

  In the work for removing and handling dust, the worker wears chemical protective clothing, rubber gloves, rubber boots, and a dust mask with a collection efficiency of 95% or more on the clothes. Of these, chemical protective clothing may be used 3 to 4 per day per worker and is basically disposable. Materials such as polyethylene and polypropylene are used as materials, and recently, handling of dust containing radioactive substances has been increasing.

  Chemical protective clothing is required to have a high level of dust resistance that prevents dust from entering the clothing and air permeability and moisture permeability that allow comfortable operation.

  Patent Documents 1 and 2 disclose an electret nonwoven sheet and a method for producing the same.

JP 2003-73971 A JP 2008-179932 A

  The nonwoven fabrics described in Patent Documents 1 and 2 have high collection efficiency and high air permeability, but using an electret nonwoven fabric alone is difficult from the standpoint of strength and wear resistance. Furthermore, regarding the laminated structure, a lamination method and a solution for protective clothing using the laminated method are not disclosed.

  It is an object of the present invention to provide a dustproof material and protective clothing that have high dustproofness that prevents dust from entering into clothes and that can perform work comfortably and have breathability and moisture permeability.

In order to solve the problem, the present invention takes the following means.
(1) A dust-proof material comprising an electret nonwoven fabric, having a laminated structure of a fiber layer and an electret nonwoven layer, wherein the sum of the number of fiber layers and electret nonwoven layers is 2 or more, and the adjacent fiber layer and electret nonwoven layer A dust-proof material that is bonded in an area of 50% or less between
(2) The dust-proof material, wherein the fiber layer and the electret non-woven fabric layer are bonded to each other in part or all of the fiber layer and the electret non-woven fabric layer.
(3) The dustproof material according to any one of the above, wherein the electret nonwoven fabric layer is a meltblown nonwoven fabric or a spunbond nonwoven fabric,
(4) The dustproof material according to any one of the above, wherein the air permeability is 5 cm ³ / cm ² / s or more,
(5) Any of the above, wherein the electret nonwoven fabric layer is a meltblown nonwoven fabric, and the meltblown nonwoven fabric contains 0.5 to 5 mass% of a hindered amine-based additive or 0.5 to 5 mass% of a triazine-based additive. Dust-proof material according to
(6) Protective clothing using the dustproof material according to any one of the above,
(7) A method for producing the dustproof material according to any one of the above, wherein the fiber layer and the electret non-woven fabric layer for constituting the dustproof material are overlapped, and a heat treatment is performed on a portion to be bonded Method,
(8) The said dust-proof material manufacturing method whose means to heat-process is an ultrasonic wave.

  ADVANTAGE OF THE INVENTION According to this invention, it is excellent in dustproof property and air permeability, and a cooler dustproof material and protective clothing can be obtained in the summer work.

It is a conceptual diagram of the charge density measurement of an electret nonwoven fabric layer. It is a conceptual diagram of the fiber layer after peeling. 1 is a conceptual diagram of a fiber layer sample 1. FIG. It is a conceptual diagram of the fiber layer sample 2. FIG.

<Electret non-woven fabric layer>
The electret nonwoven fabric layer used for the dustproof material of the present invention is a sheet made of a non-conductive fiber material, and can be obtained by a melt blow method or a spun bond method. That is, the electret nonwoven fabric layer is preferably a melt blown nonwoven fabric or a spunbond nonwoven fabric.

The melt-blowing method is generally a method in which a thermoplastic polymer extruded from a spinneret is finely divided into fibers by spraying with hot air and formed into a web by utilizing the self-bonding characteristics of the fibers. Compared to other nonwoven fabric manufacturing methods such as the spunbond method, a complicated process is not required, and fine fibers of several tens of μm to several μm or less can be easily obtained. Spinning conditions in the melt-blowing method include polymer discharge rate, nozzle temperature, air pressure, and the like. By optimizing these spinning conditions, a nonwoven fabric having a desired fiber diameter can be obtained.
The spunbond method melts the resin, spins it from the spinneret, pulls and stretches the cooled and solidified yarn with compressed air sprayed from the ejector, and collects it on the moving net to create a nonwoven fiber. This is a manufacturing method that requires a step of heat-bonding after forming into a web, and has a feature that it is easier to obtain fibers having higher strength than the melt-blowing method by pulling the resin.
The material is made of synthetic fibers or natural fibers, and among them, those made of synthetic fibers are particularly preferable.

The non-conductivity of the material of the electret is preferably a material mainly composed of a material having a volume resistivity of 10 ¹² Ω · cm or more, more preferably 10 ¹⁴ Ω · cm or more. Examples thereof include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polylactic acid, polycarbonates, polystyrenes, polyphenylene sulfites, fluororesins, and mixtures thereof. Among these, those mainly composed of polyolefin or polylactic acid are preferable from the viewpoint of electret performance. Further, among polyolefins, those mainly composed of polypropylene are more preferable.

  When the electret nonwoven fabric layer used in the present invention is a meltblown nonwoven fabric, the meltblown nonwoven fabric preferably contains a hindered amine-based additive and / or a triazine-based additive. It is because it becomes possible to hold | maintain especially high electret performance by containing this additive in a nonelectroconductive fiber sheet.

  The content of the hindered amine-based additive and / or triazine-based additive is not particularly limited, but when the melt blown nonwoven fabric contains the hindered amine-based additive or the triazine-based additive alone, their contents are respectively The range is preferably 0.5 to 5% by mass of the melt blown nonwoven fabric, more preferably 0.7% by mass or more for each upper limit and 3% by mass or less for each lower limit. Further, when the melt blown nonwoven fabric contains both the hindered amine additive and the triazine additive, the total content thereof is preferably in the range of 0.5 to 5% by mass of the melt blown nonwoven fabric, and the upper limit is set. More preferably, the content is 0.7% by mass or more and the lower limit is 3% by mass or less. If the amount added is small, it will be difficult to obtain the desired high level electret performance. On the other hand, when the amount is too large, the yarn-forming property and the film-forming property are deteriorated, and the cost is disadvantageous.

  Of the above two types of additives, hindered amine-based additives include poly [((6- (1,1,3,3, -tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl. ) ((2,2,6,6, -tetramethyl-4-piperidyl) imino) hexamethylene ((2,2,6,6, -tetramethyl-4-piperidyl) imino)] (Ciba Geigy, “Kimasoap "(Registered trademark; the same shall apply hereinafter) 944LD), dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate (Ciba Geigy," Tinuvin ") (Registered trademark, the same shall apply hereinafter) 622LD), 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,6,6-pentamethyl) -4 Piperidyl) (Ciba-Geigy, "Tinuvin" 144), and the like.

Examples of the triazine-based additive include the aforementioned poly [((6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diyl) ((2 , 2,6,6, -tetramethyl-4-piperidyl) imino) hexamethylene ((2,2,6,6, -tetramethyl-4-piperidyl) imino)] (manufactured by Ciba Geigy, “Kimasoap” 944LD), And 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-((hexyl) oxy) -phenol (manufactured by Ciba Geigy, “Tinuvin” 1577FF). Among these, it is particularly preferable to use a hindered amine additive.

The charge density of the electret nonwoven fabric layer is preferably 1 × 10 ⁻¹⁰ coulomb / cm ² or more, more preferably 1 × 10 ⁻⁹ coulomb / cm ² or more, and further preferably 1 × 10 ⁻⁸ coulomb / cm ² or more.

  In addition to the above additives, the electret non-woven fabric layer may be added with known additives generally used for non-conductive fiber sheets of electret processed products such as heat stabilizers, weathering agents, polymerization inhibitors and the like. Good.

  The method for producing the electret non-woven fabric is to bring a slit-like suction nozzle across the sheet width direction while making the non-conductive fiber sheet travel, and to bring the sheet surface opposite to the contact portion into contact with the water surface. Or a method in which water is sucked from the suction nozzle in this state. When water is sucked from the suction nozzle, the water on the opposite side of the part where the suction nozzle is in contact with the sheet moves so as to penetrate the sheet in the thickness direction, so that the water penetrates throughout the thickness direction in the sheet. be able to. In addition, since the suction nozzle is arranged so as to cross the sheet width direction and the sheet is sucked while running, the state in which water has permeated the entire sheet thickness direction can be spread evenly over the entire sheet. Therefore, when this sheet is dried, it becomes an electret sheet in which charges are uniformly and densely charged on the entire surface of the sheet.

  Moreover, the method by the direct current | flow corona discharge to a fiber sheet may be used. A direct current corona having a plurality of direct current corona discharge electrodes and acting on the electret sheet after the first direct current corona discharge electrode rather than the electric field strength by the first direct current corona discharge electrode. A method for producing an electret sheet, characterized in that the electric field strength by the discharge electrode is made stronger and electret processing using a plurality of corona electric fields is performed.

<Fiber layer>
Then, the fiber layer used for this invention is described.

  The fiber layer used for the dustproof material of the present invention is a fiber layer that is not an electret nonwoven fabric, as defined in the present invention. As such a fiber layer, it is preferable that the material has sufficient strength, wear resistance, texture such as touch, and softness. Examples of the fabric shape used as the fiber layer include fiber structures such as woven fabrics, knitted fabrics, nonwoven fabrics, and paper. Especially, a nonwoven fabric is preferable from a viewpoint of cost and a physical property. Nonwoven fabric production methods include wet nonwoven fabrics, resin bond dry nonwoven fabrics, thermal bond dry nonwoven fabrics, spunbond dry nonwoven fabrics, needle punch dry nonwoven fabrics, water jet punch dry nonwoven fabrics, melt blown dry nonwoven fabrics or flash spinning dry fabrics. In addition to non-woven fabrics, a paper making method capable of making the basis weight and thickness uniform can also be preferably used. Of these, a spunbonded nonwoven fabric is preferable from the viewpoints of cost and physical properties.

  Examples of functions required for the fiber layer include strength, wear resistance, and flexibility related to texture such as touch.

  Examples of the material for the fiber layer include polyolefins such as polyethylene and polypropylene, polyethylene terephthalate, polyesters such as polylactic acid, polycarbonate, polystyrene, polyphenylene sulfite, fluororesin, and mixtures thereof. Among these, those mainly composed of polyolefin or polylactic acid are preferable from the viewpoint of electret performance. Furthermore, in polyolefin, what mainly has a polypropylene is more preferable, and it is preferable from a viewpoint of the workability at the time of bonding that it is the same material as the above-mentioned electret nonwoven fabric layer.

  The strength of the fiber layer is preferably 5 N / 50 mm or more. More preferably, it is 10 N / 50 mm or more, More preferably, it is 15 N / 50 mm or more. When the strength is 200 N / 50 mm or more, it is necessary to remarkably increase the strength of the constituent fibers or increase the basis weight, so that softness as a dustproof material cannot be obtained. Therefore, the strength of the fiber layer is preferably less than 200 N / 50 mm.

  The abrasion resistance is preferably 3 or higher in the Taber method described in JIS L 1913: 2010 (6.6.1). More preferably, it is quaternary or higher.

  The bending resistance is preferably 150 mm or less in the a) 41.5 ° cantilever method of JIS L 1913: 2010 (6.7.1). More preferably, it is 130 mm or less. More preferably, it is 100 mm or less. If it exceeds 150 mm, the fabric has a high rigidity, which causes stiffness when used as protective clothing.

If these conditions are satisfied, the preferred fiber layer thickness is 0.01 mm or more, more preferably 0.1 mm or more. On the other hand, the preferred fiber layer thickness is 5 mm or less, more preferably 1 mm or less. The basis weight is preferably 10 g / m ² or more, more preferably 20 g / m ² or more. On the other hand, the weight per unit area is preferably 200 g / m ² or less, and more preferably 100 g / m ² or less.

  Moreover, it is preferable that the fiber layer used in the present invention has functional processing such as antistatic processing on the surface. The antistatic processing is preferably a method of processing a conductive polymer on the surface or a method of processing a hygroscopic polymer on the surface. At this time, it is preferable to process the opposite surface in contact with the electret nonwoven fabric layer to be laminated.

  It is because there exists a possibility that a charging performance may fall when an antistatic process part contacts an electret nonwoven fabric layer.

<Dust-proof material>
First, the method for producing the dustproof material of the present invention will be described. The method for producing a dustproof material in the present invention includes a production process for each constituent material and a lamination process for the material.

  A known method is used for the manufacturing process of each constituent material. The manufacturing method of a fiber layer and an electret nonwoven fabric layer is as having demonstrated above.

  Next, the lamination method of the present invention will be described.

  The dust-proof material of the present invention is characterized in that the fiber layer and the electret nonwoven layer are combined to form two or more layers.

  The fiber layer ensures strength and wear resistance for use as a dustproof material. The electret non-woven fabric layer has moisture permeability for the role of preventing dust from entering the clothes and the wearer's comfort. For this reason, the dustproof material preferably has a collection efficiency defined below of 65% or more.

  In addition, the collection efficiency in this invention says the value calculated | required with the following method. Ten measurement samples were collected from the dustproof material, and each sample was measured with a collection performance measuring device. In this collection performance measuring apparatus, a dust storage box is connected to an upstream side of a sample holder for setting a measurement sample, and a flow meter, a flow rate adjusting valve, and a blower are connected to a downstream side. Moreover, the particle counter can be used for the sample holder, and the number of dusts on the upstream side and the number of dusts on the downstream side of the measurement sample can be measured via the switching cock. Furthermore, the sample holder includes a pressure gauge, and can read the static pressure difference between the upstream and downstream of the sample.

In measuring the collection performance, a 0.3 μm diameter polystyrene standard latex powder (Nacalai Tesque 0.309 U polystyrene 10% by weight solution diluted 200-fold with distilled water) is filled in the dust storage box 2 and the sample is held in the holder. And adjust the air volume with a flow adjustment valve so that the filter passing speed is 3 m / min, and the dust concentration is 10,000 to 40,000 pieces / 2.83 × 10 ⁻⁴ m ³ (0.01 ft ³ ). Stabilized within the range, the number of dusts D upstream of the sample and the number of dusts d downstream were measured three times per sample with a particle counter (manufactured by Lion Co., Ltd., KC-01E). The average value of three samples was calculated.
Collection efficiency (%) = [1- (d / D)] × 100
Here, d is the total number of 10 times measured downstream dust.
Note that the higher the collection fiber sheet, the lower the number of downstream dusts, and the higher the collection efficiency value.

The air permeability of the dustproof material used in the present invention is preferably 5 cm ³ / cm ² / s or more, more preferably 10 cm ³ / cm ² / s or more, and still more preferably 15 cm ³ / cm ² / s or more. On the other hand, the air permeability of the dustproof material is preferably 200 cm ³ / cm ² / s or less, more preferably 150 cm ³ / cm ² / s or less, and still more preferably 100 cm ³ / cm ² / s or less.

  The dustproof material of this invention has a laminated structure of a fiber layer and an electret nonwoven fabric layer, and the sum of the number of a fiber layer and an electret nonwoven fabric layer is two or more. Examples of the laminated structure include the following. A structure having a fiber layer on the outer surface of the garment and an electret non-woven fabric layer on the inner surface of the garment. A three-layer structure in which the fiber layer, the electret nonwoven layer and the fiber layer are in this order and the electret nonwoven layer is sandwiched between them. A five-layer structure in which two layers of a highly abrasion-resistant fiber layer and a high-strength fiber layer are stacked, and the overlapped fiber laminate sandwiches the electret nonwoven fabric layer. A four-layer structure in which two electret non-woven fabric layers having different characteristics and a fiber layer are stacked on the fiber layer can be mentioned. Among these, a three-layer structure in which two fiber layers sandwich an electret nonwoven fabric layer is preferable. In this case, a fiber layer having strength and a fiber layer having wear resistance can be used. The electret non-woven fabric itself has a problem in workability at the time of wearing, sewing and the like because dust and dust are likely to adhere to the surface by itself.

  The three-layer laminated structure is preferable because an electret-processed electret non-woven fabric layer is sandwiched between fiber layers so that dust and dust are less likely to adhere to the surface without reducing the collection efficiency when air passes through.

  As a method of bonding the fiber layer and the electret nonwoven layer, in order to prevent the fiber layer or the electret nonwoven layer from being melted or fused beyond a desired state due to excessive heat, ultrasonic bonding or pattern height is required. Thermal bonding using a hot embossing roll of 1 mm or more, and bonding with an adhesive can be used. Moreover, in lamination | stacking of a fiber layer and an electret nonwoven fabric layer, it is preferable to superimpose a fiber layer and an electret nonwoven fabric layer, and to heat-process the part which should be adhere | attached, and it is preferable to use an ultrasonic wave as a means to heat-process.

  In ultrasonic bonding processing, a blade called ultrasonic blade is sandwiched between an adhesive material and an embossing roll having a specific pattern at a pressure of 0.01 MPa to 1 MPa, and a vibrator called a blade is operated at an ultrasonic vibration of 1 to 50,000 Hz. A method of oscillating and melt-bonding a pattern portion that comes into contact with the blade is exemplified. The blade is mainly made of titanium, which is resistant to friction, but aluminum, stainless steel alloy, etc. are also used. A blade width of 10 to 50 cm is used.

  The heat bonding process using a hot embossing roll with a pattern height of 1 mm or more uses a heat embossing roll with an embossing pattern depth of 1 mm or more, and performs the bonding process without applying heat to the fabric other than the pattern. . The pattern height refers to the distance between the upper part and the lower part of the edge constituting the embossed pattern of the hot embossing roll. The temperature of hot embossing is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, and still more preferably 100 ° C. or higher. On the other hand, the temperature of hot embossing is preferably 170 ° C. or lower, more preferably 150 ° C. or lower, and still more preferably 135 ° C. or lower. Further, the pressing force of the hot embossing roll and the nip roll sandwiching the hot embossing roll is preferably 0.5 MPa or more, more preferably 1 MPa or more. On the other hand, the pressing force of the nip roll is preferably 10 MPa or less, more preferably 5 MPa or less.

  The adhesive used for the bonding process using an adhesive is not particularly limited, and examples thereof include a hot melt adhesive, a powder adhesive, and a solution adhesive. Of these, hot melt adhesives are preferable from the viewpoint of cost and ability to uniformly apply to an object. Examples of the hot melt adhesive include a synthetic rubber adhesive, an olefin adhesive, and an EVA (ethylene vinyl acetate) adhesive. Synthetic rubber-based or olefin-based adhesives are preferable from the viewpoint of excellent adhesive strength and excellent compatibility with the fiber layer and the electret nonwoven fabric layer. When a hot melt adhesive is used as the adhesive, the upper limit of the melt viscosity at 140 ° C. of the hot melt adhesive is 2000 mPa · s because the hot melt adhesive can be more uniformly extruded than a T-die. Or less, more preferably 1500 mPa · s or less. On the other hand, the lower limit of the melt viscosity is preferably 300 mPa · s or more, and more preferably 500 mPa · s or more.

  The method of laminating the fiber layer and electret non-woven fabric layer with hot melt adhesive is a method of applying an adhesive from a dot-pattern roll to a substrate, applying a powdered adhesive to the base, and then heating to bond And a method of applying a melted adhesive in a spray form. Among them, a method of applying the hot melt adhesive in a spray form from a T-die type extruder is preferable. With this method, it is possible to bond the fiber layer and the electret nonwoven layer without significantly impairing the texture of the dustproof material and the breathability of the dustproof material, and the adhesive strength between the fiber layer and the electret nonwoven layer with a low coating amount. The hot melt adhesive can be more uniformly applied. In addition, when the melt viscosity at 140 ° C. of the hot melt adhesive is 2000 mPa · s or less, the hot melt when extruded from the T die from the viewpoint of being able to extrude the hot melt adhesive more uniformly than the T die. The temperature of the adhesive is preferably 100 ° C. or higher, and more preferably 130 ° C. or higher. On the other hand, from the viewpoint of suppressing damage to the dust-proof material by the high-temperature hot melt adhesive, the temperature of the hot melt adhesive when extruded from the T die is preferably 180 ° C. or lower, and is 160 ° C. or lower. Is more preferable.

  In the dustproof material of the present invention, the adjacent fiber layer and the electret nonwoven fabric layer are bonded in a region having an area of 50% or less. In the present invention, at least one pair of the adjacent fiber layer and the electret nonwoven layer may be bonded at this specific area ratio. However, in order to further obtain the effect of the present invention, the adjacent fiber layer and the electret nonwoven layer are used. It is preferable that all pairs of and are bonded within the range of this area ratio. The lower limit of the adhesion area is preferably 5% or more. On the other hand, the upper limit of the adhesion area needs to be 50% or less, preferably 40% or less, and more preferably 30% or less. When the ratio of the adhesion area is too high, the dustproof material becomes hard, and the wearability as a chemical protective clothing tends to be inferior due to the decrease in air permeability of the dustproof material. The adhesive pattern is not particularly limited, and patterns such as a pinpoint pattern, a cross pattern, a lattice pattern, a wave pattern, and a diagonal pattern can be used. When sewing is considered, left-right symmetry is preferable, and pinpoint patterns, cross patterns, lattice patterns, wave patterns, and the like are preferable.

Moreover, it is preferable that a part or all of the fibers are melted to form a film shape in the bonded portion of the fiber layer and the electret nonwoven fabric layer. The membrane-like portion of the thickness, 0.01 to 0.5 mm, and the area of the adhesive portions one ^is a 0.001 mm 2 100 mm ^2. The thickness and area of these are obtained by cutting the cross section of the bonded portion, enlarging the area of the cross section with an SEM photograph, and obtaining the thickness and area with software.

  In any of the above methods, since the heat is not applied except where it is adhered, there is little damage to the fiber layer and the electret nonwoven fabric layer due to the heat, and the shrinkage due to the melting of the fibers and the heat applied to the electret nonwoven fabric can be suppressed. .

  Among the methods described above, ultrasonic bonding is a more preferable method because neither the fiber layer nor the electret nonwoven fabric layer is heated except for the blade and the pattern portion.

  The fabric obtained by lamination can suppress strength, wear resistance, and particle ingress, and can be suitably used as a dustproof material.

  The dustproof material of the present invention can be suitably used as a protective garment by sewing into a coverall, kappa, gown or the like. In particular, a coverall-type protective clothing is preferable in preventing the entry of radioactive substances.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Measuring method]
(1) Mass per unit area (weight per unit: g / m ² )
It measured based on JIS L 1913: 2010 6.2. Three or more test pieces having a size of 25 cm × 25 cm were sampled from a sample using a punching shape or a template and a razor blade, and the weight was measured to obtain an average value. The average value was multiplied by 16 to obtain the mass per unit area (g / m ² ).

(2) Collection efficiency Ten samples for measurement were collected from the dustproof material, and each sample was measured with a collection performance measuring device. In this collection performance measuring apparatus, a dust storage box is connected to an upstream side of a sample holder for setting a measurement sample, and a flow meter, a flow rate adjusting valve, and a blower are connected to a downstream side. Moreover, the particle counter can be used for the sample holder, and the number of dusts on the upstream side and the number of dusts on the downstream side of the measurement sample can be measured via the switching cock. Furthermore, the sample holder includes a pressure gauge, and can read the static pressure difference between the upstream and downstream of the sample.
In measuring the collection performance, a 0.3 μm diameter polystyrene standard latex powder (Nacalai Tech 0.309 U polystyrene 10 mass% solution diluted 200-fold with distilled water) is filled into the dust storage box 2 and the sample is held in the holder. And adjust the air volume with the flow rate adjusting valve 4 so that the filter passing speed is 3 m / min, and the dust concentration is 10,000 to 40,000 pieces / 2.83 × 10 −4 m ³ (0.01 ft ³ ). Stabilize within the range, measure the number of dusts D upstream and d downstream of the sample three times per sample with a particle counter (Rion Co., Ltd., KC-01E). The average value of 3 samples was calculated.
Collection efficiency (%) = [1- (d / D)] × 100
Here, d: 10 times measurement total number of downstream dust.

(3) Charge Density Referring to FIG. A sample 3 is sandwiched between a grounded metal box 1 and a metal plate electrode 2 (area: 100 cm ² , material: brass), and the voltage generated by electrostatic induction is measured by an electrometer 5 through a capacitor 4. Then, the surface charge density was determined from the measured potential by the following formula using the following formula.

Q = C × V / S
Q: Surface charge density (Coulomb / cm ² )
C: Capacitor capacity V: Potential S: Plate electrode area

(4) Breathability JIS L 1913 6.8.1 a) Based on the fragile method, the amount of air passing through the test piece with a size of 15 cm × 15 cm was measured at N = 3, and the average value was determined as breathability. did.

(5) Wearability A subject wears a chemical protective suit from above a shirt and a pair of work pants in a constant temperature and humidity chamber set to 35 ° C. and 50% Rh assuming the outside temperature in summer. The test subject stuck a thermocouple near the center of the chest from the top of the shirt, and measured the temperature in the protective clothing after entering the room with the thermocouple. This was performed on three subjects. Comparing the data of three subjects with the protective clothing of Comparative Example 1, respectively, the average temperature in the protective clothing after 30 minutes is 2 ° C. or lower, A, the average temperature difference is less than 2 ° C. B evaluated.

(6) Tensile strength Measured based on JIS L 1913: 2010 6.3.1. A tensile test is performed on a sample with a size of 5 cm × 30 cm with a constant-speed extension type tensile tester for three samples in both the longitudinal and lateral directions under the conditions of a gripping interval of 20 cm and a tensile speed of 10 cm / min, and the sample breaks. The maximum strength when the sheet was pulled to the maximum was taken as the tensile strength, and the average value in the longitudinal and lateral directions of the sheet was calculated.

(7) Thickness Measured based on JIS L 1913: 2010 6.1.1 A method. Ten test pieces having a size of 2500 mm ² or more were collected from the sample, and a pressure of 0.5 kPa was applied to the upper circular horizontal plate of the thickness measuring device to adjust the zero point. Thereafter, the thickness was measured to 0.01 mm by applying a pressure of 0.5 kpa to the test piece in a standard state for 10 seconds using a thickness measuring instrument. The average value of 10 test pieces was obtained.

(8) Abrasion resistance JIS L 1913: 2010 6.6.1 a) Three test pieces measured based on the Taber method were collected, the wear wheel was CS-10, and the number of friction was 100 times. The change in appearance was compared with the limit photograph shown in FIG.

(9) Rigidity and softness JIS L 1913: 2010 6.7.1 a) It measured based on the 41.5 degree cantilever method. Three test pieces were collected from the vertical direction, and when it was expected that there would be a difference between the front and back of the sample, the test was performed on the front and back. The average value in the vertical direction was defined as bending resistance.

(10) Average fiber diameter Arbitrary 10 fiber diameters were taken at 10 magnifications with an electron microscope at a magnification of 500 times, and the diameters of any 15 fibers per photo were measured. The average fiber diameter was expressed by the average value.

(11) Ten points of 20 mm square samples were cut out from the adhesion area dustproof material. The fiber layer was peeled from each of the above samples to obtain 10 peeled fiber layers. The adhesive and the fibers derived from the electret nonwoven layer were adhered to the surface of the ten peeled fiber layers bonded to the electret nonwoven layer. The fibers derived from the electret non-woven fabric attached to the fiber layer include fibers attached to the fiber layer by an adhesive (hereinafter referred to as fiber 9) and fibers attached to the fiber layer without contact with the adhesive ( Hereinafter, there were two types of fibers 10). Next, from the obtained 10 peeled fiber layers, arbitrarily select 5 peeled fiber layers, and from the surface bonded to the electret nonwoven fabric layer of the peeled fiber layers, the above All the fibers derived from the two types of electret nonwoven layers were removed, and a fiber layer sample 1 after peeling was obtained.
Moreover, about the remaining 5 fiber layers after peeling among the 10 fiber layers after peeling, only the fibers 10 from the surface bonded to the electret nonwoven fabric layer of those fiber layers after peeling. Was removed using # 320 sandpaper to obtain a fiber layer sample 2 after peeling.
Here, the fiber layer after peeling is shown in FIG. 2a. Adhesive 8 and fibers derived from the electret nonwoven fabric layer are attached to the surface 7 of the fiber layer 6 after being peeled and adhered to the electret nonwoven fabric layer. The fibers derived from the electret non-woven fabric layer include fiber 9 and fiber 10.
The fiber layer sample 1 is shown in FIG. Only the adhesive 8 is adhered to the fiber layer sample 1.
The fiber layer sample 2 is shown in FIG. Adhesive 8 and fibers 9 are attached to the fiber layer sample.
Each of the surfaces bonded to the electret nonwoven fabric layers of the obtained fiber layer samples 1 and 2 after peeling was peeled off from the entire field of view by using Keyence VHX2000 at a magnification of 150 times and a threshold of -60. The fiber layer sample 1 or 2 was photographed to obtain a rectangular image. Next, the obtained image was divided into four at the center of each of the long side and the short side. Furthermore, using the method of calculating the area of the fiber part by the difference in brightness in the upper left part of the four-divided image, each fiber part of the surface bonded to the electret nonwoven fabric layer of the fiber layer samples 1 and 2 after peeling The area was calculated. Next, S1 is the average value of the area of the fiber portion of the surface that was adhered to the electret nonwoven fabric layer of the five obtained fiber layer samples 1 after peeling, and the five fiber layer samples 2 after peeling were obtained. The average value of the area of the fiber part of the surface bonded to the electret nonwoven fabric layer was S2, and the value obtained by the calculation formula of S2-S1 was the bonding area.

(12) Melt viscosity JIS Z 8803 9.4.4 Measured based on a measurement method using a single cylindrical rotational viscometer. The viscosity at 140 ° C. was determined using a B-type rotational viscometer (manufactured by Brookfield).

(Fabric layer fabric)
The following fabric was used for the fabric for the fiber layer. The physical properties are shown in Table 1.

<Spunbond 1>
Spunbond nonwoven fabric made of polypropylene (breathability: 220 cm ³ / cm ² / s, basis weight: 15 g / m ² , tensile strength: vertical 46.3 / width 17.5 N / 50 mm, wear resistance: 4.5 grade, stiffness: 73 mm )

(Fabric for electret non-woven fabric layer)
The following materials were used as the fabric for the electret nonwoven fabric layer and the control fabric used in the comparative example. The physical properties are shown in Table 2.

<Melt blow 1>
Melt blown nonwoven fabric made of polypropylene (containing 1% by weight of hindered amine additive, with electret processing, charge density 8.5 × 10 ⁻⁹ coulomb / cm ² , air permeability 24 cm ³ / cm ² / s, basis weight 25 g / m ² , average fiber Diameter 2 μm).

<Melt blow 2>
Melt blown nonwoven fabric made of polypropylene (containing 1% by weight of hindered amine additive, with electret processing, charge density 1.0 × 10 ⁻⁹ coulomb / cm ² , air permeability 105 cm ³ / cm ² / s, basis weight 25 g / m ² , average fiber (Diameter 6 μm).

<Melt blow 3>
Melt blown nonwoven fabric made of polypropylene (no electret processing, air permeability 24 cm ³ / cm ² / s, basis weight 25 g / m ² , average fiber diameter 2 μm).

<Melt blow 4>
Melt blown nonwoven fabric made of polypropylene (no electret processing, air permeability 105 cm ³ / cm ² / s, basis weight 25 g / m ² , average fiber diameter 6 μm).

<Spunbond 2>
Spunbond nonwoven fabric made of polypropylene (with electret processing, charge density 5.0 × 10 ⁻¹⁰ coulomb / cm ² , air permeability 135 cm ³ / cm ² / s, basis weight 25 g / m ² , average fiber diameter 20 μm).

[Example 1]
Polypropylene melt blown nonwoven fabric (melt blow 1) having an average fiber diameter of 2 μm and basis weight of 25 g / m ² , using an ultrasonic bonding machine (8400 manufactured by Bobson) and having a basis weight of 15 g / m ² polypropylene nonwoven fabric (spunbond 1) and electret processing. ) And spunbond 1 were bonded to each other at a frequency of 20,000 Hz and a pressure of 0.03 MPa so as to form a cross pattern with a bonding area of 10%. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 1.
The obtained dustproof material 1 had a basis weight of 55 g / m ² , a collection efficiency of 99%, and an air permeability of 14 cm ³ / cm ² / s.
When a coverall type chemical protective clothing having the same form as the protective clothing of Comparative Example 1 to be described later was prepared using the dustproof material 1, there was no dust adhering to the fabric at the time of sewing, and good sewing properties were obtained. When the wearability was evaluated under a% Rh atmosphere, the temperature difference from Comparative Example 1 was -2.2 ° C, and the wearability was evaluated as A.

[Example 2]
A dustproof material 2 was prepared in the same manner as in Example 1 except that a polypropylene melt blown nonwoven fabric (melt blow 2) having a basis weight of 25 g / m ² was used instead of the melt blow 1. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 2.
The obtained dustproof material 2 had a basis weight of 55 g / m ² , a collection efficiency of 80%, and a breathability of 90 cm ³ / cm ² / s.
A coverall type chemical protective clothing was created using dustproof material 2 in the same manner as in Example 1. The coverall type chemical protective clothing was sewn to the fabric without sewing dust at the time of sewing, and was worn in an atmosphere of 35 ° C. and 50% Rh. When the property was evaluated, the temperature difference from Comparative Example 1 was −3.5 ° C., and the evaluation of the wearability was A.

[Example 3]
An adhesion method using a hot press roll having a handle height of 1 mm or more was used. Using the same spunbond 1, meltblown 1, and spunbond 1 configurations as in Example 1, a roll having a bonding height of 10% and a roll height of 3 mm where the roll surface other than the bonded portion does not touch the fabric is used, and the roll temperature is 130 ° C. Bonding was performed at a roll pressure of 3 Mpa and a processing speed of 2 m / min to obtain a dustproof material 3. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 3.
The dustproof material 3 had a basis weight of 55 g / m ² , a collection efficiency of 99%, and air permeability of 13 cm ³ / cm ² / s.
A coverall type chemical protective clothing was created using dustproof material 3 in the same manner as in Example 1. The coverall type chemical protective clothing was sewn to the fabric without any dust adhering to the fabric at the time of sewing, and was further worn at 35 ° C. and 50% Rh atmosphere. When the property was evaluated, the temperature difference from Comparative Example 1 was −2.1 ° C., and the evaluation of the wearability was A.

[Example 4]
Adhesion processing was performed in the same manner as in Example 3 except that the melt blow 1 used in Example 3 was bonded as the melt blow 2 to obtain a dustproof material 4. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 4.

The dustproof material 4 had a basis weight of 55 g / m ^{2 and a} collection efficiency of 79%, and air permeability of 92 cm ³ / cm ² / s.
A coverall-type chemical protective suit was created using dustproof material 4 in the same manner as in Example 1. The coverall type chemical protective clothing was sewn to the fabric without seizing dust during sewing, and was further worn at 35 ° C. and 50% Rh atmosphere. When the property was evaluated, the temperature difference from Comparative Example 1 was −3.6 ° C., and the evaluation of the wearability was A.

[Example 5]
A dustproof material 5 was obtained in the same manner as in Example 1 except that a two-layer structure of spunbond 1 and meltblown 1 was adopted. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 5.
The dustproof material 5 had a basis weight of 40 g / m ² , a collection efficiency of 99%, and air permeability of 22 cm ³ / cm ² / s.
A coverall type chemical protective clothing was prepared using the dustproof material 5 with the melt blow layer as the inner side in the same manner as in Example 1, and the wearability was evaluated in an atmosphere of 35 ° C. and 50% Rh. Was −2.5 ° C., and the evaluation of wearability was A.

[Example 6]
Adhesive processing was performed in the same manner as in Example 5 except that the melt blow 1 used in Example 5 was bonded as the melt blow 2 to obtain a dustproof material 6. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 6.
The dustproof material 6 had a basis weight of 40 g / m ² , a collection efficiency of 80%, and an air permeability of 98 cm ³ / cm ² / s.
Coverall type chemical protective clothing was prepared in the same manner as in Example 1 using the dustproof material 6 and the meltblown layer inside, and the wearability was evaluated in an atmosphere of 35 ° C. and 50% Rh. Was −3.7 ° C., and the evaluation of wearability was A.

[Example 7]
In the same manner as in Example 1, a dustproof material 7 was obtained by superposing three layers of spunbond 1, meltblown 1, and spunbond 1 with an ultrasonic bonding area of 5%. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 7.
The dust-proof material 7 had a fabric weight of 55 g / m ² , a collection efficiency of 99%, a breathability of 20 cm ³ / cm ² / s, and a slightly higher breathability than that of Example 1.
A coverall-type chemical protective clothing was created using dustproof material 7 in the same manner as in Example 1. The coverall type chemical protective clothing was sewn to the fabric without sewing dust at the time of sewing, and was worn in an atmosphere of 35 ° C. and 50% Rh. When the property was evaluated, the temperature difference from Comparative Example 1 was −2.7 ° C., and the evaluation of the wearability was A.

[Example 8]
A dustproof material 8 was obtained in the same manner as in Example 1 except that the bonding area of the ultrasonic bonding process was 25%. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 8.
The dustproof material 8 had a basis weight of 55 g / m ² , a collection efficiency of 99%, and air permeability of 12 cm ³ / cm ² / s.
Coverall-type chemical protective clothing was created using dustproof material 8 in the same manner as in Example 1. The coverall-type chemical protective suit was sewn without any dust adhering to the fabric at the time of sewing, and was worn in an atmosphere of 35 ° C. and 50% Rh. When the property was evaluated, the temperature difference from Comparative Example 1 was −2.5 ° C., and the evaluation of the wearability was A.

[Example 9]
A dustproof material 9 was obtained in the same manner as in Example 1 except that the bonding area of the ultrasonic bonding process was 40%. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 9.
The dustproof material 9 had a basis weight of 55 g / m ² , a collection efficiency of 99%, and air permeability of 10 cm ³ / cm ² / s.
Coverall-type chemical protective clothing was created using dustproof material 9 in the same manner as in Example 1, and it had good sewing properties without dust adhering to the fabric during sewing, and was worn in an atmosphere of 35 ° C. and 50% Rh. When the property was evaluated, the temperature difference from Comparative Example 1 was −2.4 ° C., and the evaluation of the wearability was A.

[Example 10]
A dustproof material 10 was obtained in the same manner as in Example 1 except that the bonding area of the ultrasonic bonding process was changed to 50%. The physical property measurement results of the obtained dustproof material 10 are shown in Table 1.
The dustproof material 10 had a basis weight of 55 g / m ² , a collection efficiency of 99%, and an air permeability of 5 cm ³ / cm ² / s.
A coverall-type chemical protective suit was created using dustproof material 10 in the same manner as in Example 1. The coverall-type chemical protective suit was sewn with no dust adhering to the fabric at the time of sewing, and was worn in an atmosphere of 35 ° C. and 50% Rh. When the property was evaluated, the temperature difference from Comparative Example 1 was −2.1 ° C., and the evaluation of the wearability was A.

[Example 11]
A dustproof material 11 was prepared in the same manner as in Example 1 except that a polypropylene spunbond nonwoven fabric (spunbond 2) having a basis weight of 25 g / m ² was used instead of the melt blow 1. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 11.
The obtained dust-proof material 11 had a basis weight of 55 g / m ² , a collection efficiency of 84%, and an air permeability of 134 cm ³ / cm ² / s.
A coverall-type chemical protective suit was created using dustproof material 11 in the same manner as in Example 1. The coverall-type chemical protective suit was sewn without any dust adhering to the fabric at the time of sewing, and was further worn under an atmosphere of 35 ° C. and 50% Rh. When the property was evaluated, the temperature difference from Comparative Example 1 was −3.7 ° C., and the evaluation of the wearability was A.

[Example 12]
Spunbond 1 and meltblown 1 were the same as in Example 1 except that they were bonded using a hot melt adhesive (MORESCO Co., Ltd. Morescomelt: TN-367Z, melt viscosity of 1200 mPa · s at 140 ° C.). The hot melt adhesive is heated and melted at 150 ° C. in a hot melt adhesive machine, and sprayed from the T-die type extruder so that the coating amount is 3 g / m ^{2 on} the first surface of the melt blow 1. After coating, spunbond 1 was bonded to the first surface of meltblown 1. After winding the obtained two-layer laminate of spunbond 1 / melt blow 1, reverse the front and back, and spray the adhesive on the second surface of the melt blow 1 again so that the coating amount is 3 g / m ² again. Then, the spunbond 1 was bonded to the second surface of the melt blow 1 to obtain a dustproof material 12 of spun bond 1 / melt blow 1 / spun bond 1. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 12.
The dust-proof material 12 had a basis weight of 60 g / m ² , a collection efficiency of 99%, and a breathability of 10 cm ³ / cm ² / s bonded area of 8%.
A coverall-type chemical protective suit was created using dustproof material 12 in the same manner as in Example 1. The coverall type chemical protective clothing was created and had good sewing properties without dust adhering to the fabric during sewing, and was further worn under an atmosphere of 35 ° C. and 50% Rh. When the property was evaluated, the temperature difference from Comparative Example 1 was −2.1 ° C., and the evaluation of the wearability was A.

[Example 13]
A dustproof material 13 was obtained in the same manner as in Example 12 except that the melt blow 1 was changed to the melt blow 2. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 13.
The dust-proof material 13 had a basis weight of 60 g / m ² , a collection efficiency of 82%, a gas permeability of 88 cm ³ / cm ² / s, and an adhesion area of 8%.
A coverall-type chemical protective suit was created using dustproof material 13 in the same manner as in Example 1. The coverall-type chemical protective suit was sewn without any dust adhering to the fabric at the time of sewing, and was further worn at 35 ° C. and 50% Rh atmosphere. When the property was evaluated, the temperature difference from Comparative Example 1 was −3.5 ° C., and the evaluation of the wearability was A.

[Comparative Example 1]
A cloth is cut out from a single layer of protective flash-spun nonwoven fabric made of polyethylene, the physical properties are measured, and the dust-proof material 14 is obtained. Tables 3 and 4 show the measurement results.
The dustproof material 14 had a basis weight of 40 g / m ² , a collection efficiency of 80%, and a breathability of 0.1 cm ³ / cm ² / s.
The same commercially available protective clothing as the above-mentioned protective clothing was worn, and the wearability was evaluated under an atmosphere of 35 ° C. and 50% Rh, and the measurement results were compared with the examples. Dust-proof material 14 is lightweight and easy to move as a protective garment, but the wind is a little difficult to pass through. When the wearability test is performed, the temperature inside the protective garment after 30 minutes is 34.2 ° C. The wearing feeling was B.

[Comparative Example 2]
A dustproof material 15 was obtained in the same manner as in Example 1 except that the melt blow 1 in Example 1 was changed to the melt blow 3 that was not electret processed. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 15.
The dust-proof material 15 has a basis weight of 55 g / m ² , a collection efficiency of 60%, and an air permeability of 14 cm ³ / cm ² / s, and the collection efficiency was lower than that of the examples.
A coverall-type chemical protective suit was prepared from the dustproof material 15 in the same manner as in Example 1, and was worn and evaluated for wearability in a 35 ° C., 50% Rh atmosphere. The temperature difference from Comparative Example 1 was The wearability was A and the collection efficiency was 65% or less.

[Comparative Example 3]
A dustproof material 16 was obtained in the same manner as in Example 1 except that the melt blow 1 in Example 1 was changed to the melt blow 4 that was not electret processed. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 16.
The dustproof material 16 has a basis weight of 55 g / m ² , a collection efficiency of 40%, and a breathability of 90 cm ³ / cm ² / s, and the collection efficiency was lower than that of the examples.
A coverall-type chemical protective suit was prepared from the dustproof material 16 in the same manner as in Example 1, and was worn and evaluated for wearability in an atmosphere of 35 ° C. and 50% Rh. The temperature difference from Comparative Example 1 was It was -3.5 degreeC, the wearability was A, and the collection efficiency was 65% or less.

[Comparative Example 4]
A dustproof material 17 was obtained in the same manner as in Example 1 except that the bonding area of ultrasonic bonding was set to 70%. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 17.
The dustproof material 17 had a basis weight of 55 g / m ² , a collection efficiency of 99%, and air permeability of 3 cm ³ / cm ² / s.
A coverall-type chemical protective suit was created using dustproof material 17 in the same manner as in Example 1. The coverall type chemical protective suit was sewn without any dust adhering to the fabric at the time of sewing, and was further worn under an atmosphere of 35 ° C. and 50% Rh. When the property was evaluated, the temperature difference from Comparative Example 1 was −1.7 ° C., and the wear property was evaluated as B.

[Comparative Example 5]
An adhesion method using a hot press roll was used. Using the same spunbond 1, meltblown 1, and spunbond 1 configurations as in Example 1, using a roll with a pattern height of 0.3 mm, performing a bonding process at a roll temperature of 130 ° C., a roll pressure of 3 Mpa, and a processing speed of 2 m / min. Dust-proof material 18 was obtained. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 18.
The dust-proof material 18 has a basis weight of 55 g / m ² , a collection efficiency of 99%, and a breathability of 3 cm ³ / cm ² / s. The fibers are substantially bonded to each other and the adhesion area is 100%. However, it was inferior compared with the Example.
A coverall-type chemical protective clothing was prepared from the dustproof material 18 in the same manner as in Example 1, and was worn and evaluated for wearability in a 35 ° C., 50% Rh atmosphere. The temperature difference from Comparative Example 1 was The evaluation of the wearability was B.

[Comparative Example 6]
A dustproof material 19 was obtained with the same structure of spunbond 1, meltblown 1, and spunbond 1 as in example 1, except that the hot melt adhesive was used. Tables 3 and 4 show the physical property measurement results of the obtained dustproof material 19.
The dust-proof material 19 has a basis weight of 55 g / m ² , a collection efficiency of 99%, and air permeability of 3 cm ³ / cm ² / s, and the air permeability was inferior to that of the examples due to the adhesive.
A coverall-type chemical protective suit was created from the dustproof material 19 in the same manner as in Example 1, and was worn and evaluated for wearability in a 35 ° C., 50% Rh atmosphere. The temperature difference from Comparative Example 1 was The evaluation of the wearability was B.

The dustproof material of the present invention is effective for dustproof clothing worn in a dusty atmosphere.

1: Metal box 2: Metal flat electrode 3: Sample 4: Capacitor 5: Electrometer 6: Fiber layer after peeling 7: Surface bonded to the electret nonwoven layer 8: Adhesive 9: Fiber layer by adhesive The fiber derived from the electret nonwoven layer adhering to the fiber: The fiber derived from the electret nonwoven layer adhering to the fiber layer without contact with the adhesive

Claims (8)

It has a laminated structure of a fiber layer and an electret nonwoven layer, the sum of the number of fiber layers and electret nonwoven layers is 2 or more, and it adheres in an area with an area of 50% or less between the adjacent fiber layer and the electret nonwoven layer Dust-proof material. The adhesion part of a fiber layer and an electret nonwoven fabric layer is a dust-proof material of Claim 1 in which a part or all of a fiber layer and an electret nonwoven fabric layer is fuse | melted, and it is a film | membrane form. The dustproof material according to claim 1 or 2, wherein the electret nonwoven fabric layer is a meltblown nonwoven fabric or a spunbond nonwoven fabric. The dustproof material in any one of Claims 1-3 whose air permeability is 5 cm < ³ > / cm < ² > / s or more. The electret nonwoven fabric layer is a meltblown nonwoven fabric, and the meltblown nonwoven fabric contains 0.5 to 5% by mass of a hindered amine-based additive or 0.5 to 5% by mass of a triazine-based additive. Dustproof material. Protective clothing using the dustproof material according to claim 1. A method for producing a dustproof material according to any one of claims 1 to 6, wherein a fiber layer and an electret non-woven fabric layer for constituting the dustproof material are overlapped, and a heat treatment is performed on a portion to be bonded. Manufacturing method. The method for producing a dustproof material according to claim 7, wherein the means for performing the heat treatment is ultrasonic.

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