Laminated nonwoven fabric, method for manufacturing the same, and protective clothing

Abstract

Provided are a multilayer nonwoven fabric having both high water resistance and antistatic properties despite no films being layered therein, a method for producing the multilayer nonwoven fabric, and a protective garment using the multilayer nonwoven fabric. One surface of the multilayer nonwoven fabric is formed from fibers comprising a polyolefin resin and has a spunbond nonwoven fabric layer A1 containing at least a phosphate ester arranged thereon, the other surface has arranged thereon a spunbond nonwoven fabric layer A2 formed from fibers comprising a polyolefin resin, and a meltblown nonwoven fabric layer B formed from at least one layer of fibers comprising a polyolefin resin is arranged between the spunbond nonwoven fabric layer A1 and the spunbond nonwoven fabric layer A2. The ratio (tA1 / tA2) of the thickness (tA1) of the spunbond nonwoven fabric layer A1 to the thickness (tA2) of the spunbond nonwoven fabric layer A2 in a non-fused section of the multilayer nonwoven fabric is 1.5-3.0.

Description

[Technical Field]

[0001] The present invention relates to a laminated nonwoven fabric, and more particularly to a laminated nonwoven fabric composed of fibers made of polyolefin resin, which has excellent water resistance and antistatic properties, and is highly productive for use in protective clothing. [Background technology]

[0002] In recent years, nonwoven fabrics have been used in a variety of applications, including industrial materials, civil engineering materials, construction materials, consumer goods, agricultural materials, sanitary materials, and medical materials.

[0003] In particular, its use in protective clothing is attracting attention due to the decontamination work of radioactive materials and the global spread of infectious diseases. Nonwoven fabrics used in protective clothing need to have both water resistance and dust protection performance to protect the wearer from chemical mist, dust, and aerosols that cause infectious diseases generated at manufacturing sites.

[0004] Conventionally, protective clothing materials have been proposed that consist of a polypropylene spunbond nonwoven fabric laminated with a porous film (see, for example, Patent Document 1).

[0005] Furthermore, protective clothing used in applications where it is necessary to suppress the generation of static electricity that can ignite fires and prevent dust explosions requires antistatic properties. For example, a laminated nonwoven fabric has been proposed as a protective clothing material that possesses antistatic properties, which is made by laminating a polypropylene spunbond nonwoven fabric coated with a cationic or nonionic antistatic agent with a meltblown nonwoven fabric (see, for example, Patent Document 2). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2016-102202 [Patent Document 2] International Publication No. 2019 / 171995 [Overview of the project] [Problems that the invention aims to solve]

[0007] Conventional protective clothing materials, such as laminates of nonwoven fabric and porous film, maintain water resistance due to the film, but suffer from poor breathability, leading to stuffiness inside the garment during wear and making prolonged work impossible. Furthermore, laminated nonwoven fabrics, formed by bonding a polypropylene spunbond nonwoven fabric coated with an antistatic agent to a meltblown nonwoven fabric, offer breathability due to the absence of a film, improving stuffiness inside the garment during wear. However, the antistatic agent absorbs moisture from the air, liquefies, penetrates the laminated nonwoven fabric, and reaches the meltblown nonwoven fabric, resulting in reduced water resistance. Therefore, the object of the present invention, viewed in light of the above circumstances, is to provide a laminated nonwoven fabric, a method for manufacturing the same, and protective clothing using the same, which possess both high water resistance and antistatic properties without the need for film lamination. [Means for solving the problem]

[0008] The inventors, through diligent research to achieve the above objective, have found that by using a laminated nonwoven fabric in which a spunbond nonwoven fabric layer made of polyolefin resin fibers and containing at least phosphate ester is disposed on one surface of the laminated nonwoven fabric, a spunbond nonwoven fabric layer is disposed on the other surface, and a meltblown nonwoven fabric layer made of polyolefin resin fibers is disposed between them, and by controlling the ratio of the thicknesses of the spunbond nonwoven fabric layers on both sides of the laminated nonwoven fabric, it is possible to achieve both high water resistance and antistatic properties.

[0009] This invention was completed based on these findings, and according to this invention, the following inventions are provided.

[0010] [1] On one surface, a spunbond nonwoven fabric layer A1 is provided, which is composed of fibers made of polyolefin resin and contains at least a phosphate ester. On the other surface, a spunbond nonwoven fabric layer A2 made of fibers from a polyolefin resin is disposed. A laminated nonwoven fabric is provided, wherein a meltblown nonwoven fabric layer B, composed of at least one layer of polyolefin resin fibers, is disposed between the spunbond nonwoven fabric layer A1 and the spunbond nonwoven fabric layer A2, The thickness (t) of the spunbond nonwoven fabric layer A1 in the non-fused portion of the laminated nonwoven fabric. A1 The thickness (t) of the spunbond nonwoven fabric layer A2. A2 ) ratio (t A1 / t A2 ) is between 1.5 and 3.0 the law of nature, The height H of the non-fused portion on one surface of the laminated nonwoven fabric. 1 The thickness is 50 μm or more and 200 μm or less, and the height H of the non-fused portion of the other surface. 2 The aforementioned height H 1 Ratio to (H 2 / H 1 ) is between 1.1 and 4.0 Laminated nonwoven fabric.

[0012] [ 2 The spunbond nonwoven fabric layer A1 further contains silicone, 1] The laminated nonwoven fabric described.

[0013] [ 3 ] The thickness of the meltblown nonwoven fabric layer B (t B The ratio (t) of the total thickness (t) of the laminated nonwoven fabric B / t) is 0.05 or more and 0.15 or less, the above [1 ] The laminated nonwoven fabric described.

[0014] [ 4 ]the aforementioned [1 ] A method for manufacturing the laminated nonwoven fabric described above, A process of forming a laminate by forming a spunbond nonwoven fabric layer, forming at least one meltblown nonwoven fabric layer thereon, and further forming a spunbond nonwoven fabric layer thereon, The process of obtaining a sheet involves fusing the laminate using a thermal embossing roll consisting of a roll with a smooth surface on one side and a roll with an engraved surface on the other side. The process involves selecting the spunbond nonwoven fabric layer on the side of the sheet that has a smooth roll surface in contact with the roll, designating it as spunbond nonwoven fabric layer A1, and applying a liquid containing at least a phosphate ester to the surface of spunbond nonwoven fabric layer A1. A method for manufacturing laminated nonwoven fabrics, including the method described above.

[0015] [ 5 The liquid further contains silicone, 4 A method for manufacturing laminated nonwoven fabric as described in [ ].

[0016] [ 6 ]the aforementioned [1 ] A protective suit having the described laminated nonwoven fabric used in at least the front of the suit.

[0017] [ 7 ] 80% to 100% of the mass is the above [1 ] Protective clothing made of the laminated nonwoven fabric described. [Effects of the Invention]

[0018] According to the present invention, a laminated nonwoven fabric composed of polyolefin resin fibers, having excellent water resistance and antistatic properties, and suitable for protective clothing applications, as well as a method for producing the laminated nonwoven fabric, and protective clothing obtained from the laminated nonwoven fabric, can be obtained. [Brief explanation of the drawing]

[0019] [Figure 1] Figure 1 is a cross-sectional conceptual diagram illustrating one embodiment of the laminated nonwoven fabric of the present invention. [Modes for carrying out the invention]

[0020] The laminated nonwoven fabric of the present invention is composed of fibers made of a polyolefin resin on one surface, and has a spunbond nonwoven fabric layer A1 containing at least a phosphate ester disposed thereon. On the other surface, a spunbond nonwoven fabric layer A2 composed of fibers made of a polyolefin resin is disposed. Between the spunbond nonwoven fabric layer A1 and the spunbond nonwoven fabric layer A2, there is a meltblown nonwoven fabric layer B composed of fibers made of at least one layer of a polyolefin resin. The laminated nonwoven fabric is such that the ratio (t A1 ) of the thickness (t A2 ) of the spunbond nonwoven fabric layer A1 to the thickness (t A1 ) of the spunbond nonwoven fabric layer A2 at the non-fused portion of the laminated nonwoven fabric is 1.5 or more and 3.0 or less the law of nature, The height H of the non-fused portion on one surface of the laminated nonwoven fabric. 1 The thickness is 50 μm or more and 200 μm or less, and the height H of the non-fused portion of the other surface. 2 The aforementioned height H 1 Ratio to (H 2 / H 1 ) is between 1.1 and 4.0 . The components will be described in detail below, but the present invention is not limited to the scope described below as long as the gist thereof is not exceeded.

[0021] [Polyolefin resin] The spunbond nonwoven fabric layer A1, the spunbond nonwoven fabric layer A2, and the meltblown nonwoven fabric layer B according to the present invention are all composed of fibers made of a polyolefin resin. Here, the "polyolefin resin" in the present invention refers to a resin whose main repeating unit is an olefin unit. Similarly, the "polyethylene resin" and the "polypropylene resin" refer to resins whose main repeating units are an ethylene unit and a propylene unit, respectively. In the present invention, the polyolefin resin used for the fibers constituting the spunbond nonwoven fabric layer A1 and the fibers constituting the spunbond nonwoven fabric layer A2 is referred to as polyolefin resin (P A ), and the polyolefin resin used for the fibers constituting the meltblown nonwoven fabric layer B is referred to as polyolefin resin (P​​B ) is sometimes referred to as such.

[0022] Examples of polyolefin resins include polyethylene resins, polypropylene resins, polybutene resins, and polymethylpentene resins. Examples of polyethylene resins include ethylene homopolymers or copolymers of ethylene and various α-olefins, while examples of polypropylene resins include propylene homopolymers or copolymers of propylene and various α-olefins. Among these, polypropylene resins are preferred from the viewpoint of spinnability and strength properties.

[0023] In this polypropylene resin, the proportion of propylene units is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. By doing so, good spinnability can be maintained and strength can be improved.

[0024] The aforementioned polyolefin resin (P A Preferably, the melt flow rate (sometimes abbreviated as MFR) is 75 g / 10 min or more and 850 g / 10 min or less. By setting the MFR to 75 g / 10 min or more, more preferably 120 g / 10 min or more, and even more preferably 155 g / 10 min or more, the stress during stretching can be reduced, and stable spinning is possible even when stretched at a fast spinning speed. As a result, the fiber diameter of the spunbond nonwoven fabric layer becomes finer, the surface is smoothed, and antistatic agents such as phosphate esters are uniformly applied to the surface, so a laminated nonwoven fabric with good antistatic properties can be obtained. On the other hand, by setting the MFR to 850 g / 10 min or less, more preferably 600 g / 10 min or less, and even more preferably 400 g / 10 min or less, polyolefin resin (P A As the molecular weight of the fibers increases, the strength per fiber increases, making it possible to obtain a laminated nonwoven fabric with sufficient strength for use as a protective clothing material.

[0025] Furthermore, the aforementioned polyolefin resin (P BPreferably, the MFR is 200 g / 10 min or more and 2500 g / 10 min or less. By setting the MFR to 200 g / 10 min or more, more preferably 400 g / 10 min or more, and even more preferably 600 g / 10 min or more, the stress during stretching is reduced, so that a meltblown nonwoven fabric layer with a fine fiber diameter can be obtained while maintaining production capacity, making it possible to achieve both productivity and water resistance. On the other hand, by setting the MFR to 2500 g / 10 min or less, more preferably 2000 g / 10 min or less, and even more preferably 1500 g / 10 min or less, the back pressure of the die becomes larger, and fluctuations in the resin discharge amount can be suppressed, so that the fiber diameter of the meltblown nonwoven fabric layer becomes uniform, and a laminated nonwoven fabric with less variation in water pressure resistance can be obtained.

[0026] In this invention, the MFR of polyolefin resins is determined by the value obtained according to ASTM D1238 (Method A). According to this standard, for example, polypropylene is measured under a load of 2.16 kg at a temperature of 230°C, and polyethylene is measured under a load of 2.16 kg at a temperature of 190°C.

[0027] The polyolefin resin used in the present invention may be a mixture of two or more types, and a resin composition containing other polyolefin resins or thermoplastic elastomers may also be used. Naturally, two or more resins with different MFRs can be blended in any proportion to form a polyolefin resin (P A ), and / or polyolefin resins (P B The MFR of the blended resin can also be adjusted. In this case, the MFR of the blended resin to the main polyolefin resin is preferably 10 g / 10 min to 1000 g / 10 min, more preferably 20 g / 10 min to 800 g / 10 min, and even more preferably 30 g / 10 min to 600 g / 10 min. Doing so prevents partial viscosity variations, uneven fineness, and deterioration of spinnability in the blended polyolefin resin.

[0028] The polyolefin resin used in the present invention may contain additives such as antioxidants, weathering agents, light stabilizers, anti-fogging agents, blocking agents, lubricants, nucleating agents, and pigments such as titanium dioxide, or other polymers, as necessary, within limits that do not impair the effects of the present invention.

[0029] Furthermore, when spinning the fibers described later, in order to prevent the occurrence of localized viscosity variations, to make the fiber fineness uniform, and to make the fiber diameter even thinner as described later, the molecular weight of the resin used may be reduced to increase the MFR. Methods for increasing the MFR include, for example, heating the resin before use to decompose it by heat, or adding peroxides and heat-treating it.

[0030] The melting point of the polyolefin resin used in the present invention is preferably 80°C or higher and 200°C or lower. Setting the melting point preferably to 80°C or higher, more preferably to 100°C or higher, and even more preferably to 120°C or higher makes it easier to obtain heat resistance that is suitable for practical use. Furthermore, setting the melting point preferably to 200°C or lower, and more preferably to 180°C or lower, makes it easier to cool the yarn extruded from the spindle, suppressing fusion between fibers and facilitating stable spinning.

[0031] [fiber] The polyolefin resin (P A The fibers made of the material preferably have an average single fiber diameter of 10.0 μm or more and 14.0 μm or less. By setting the average single fiber diameter preferably to 10.0 μm or more, and more preferably to 12.0 μm or more, the decrease in water pressure resistance due to the penetration of post-processing agents by capillary action can be suppressed. On the other hand, by setting the average single fiber diameter preferably to 14.0 μm or less, and more preferably to 13.0 μm or less, a laminated nonwoven fabric with high flexibility and uniformity can be obtained, and even if the content ratio of the meltblown nonwoven fabric layer in the laminated nonwoven fabric is low, a laminated nonwoven fabric with excellent water resistance that can withstand practical use can be obtained.

[0032] The polyolefin resin (P AThe fibers made of the material preferably have an average single fiber diameter of 6.5 μm or more and 10.0 μm or less. By setting the average single fiber diameter to preferably 6.5 μm or more, more preferably 7.5 μm or more, and even more preferably 8.4 μm or more, a decrease in spinnability can be prevented, and a nonwoven fabric layer with a stable average single fiber diameter can be formed. On the other hand, by setting the average single fiber diameter to preferably 10.0 μm or less, and more preferably 9.0 μm or less, a laminated nonwoven fabric with high flexibility and uniformity can be obtained, and even if the content ratio of the meltblown nonwoven fabric layer in the laminated nonwoven fabric is low, a laminated nonwoven fabric with excellent water resistance that can withstand practical use can be obtained.

[0033] Furthermore, the polyolefin resin (P) that constitutes the spunbond nonwoven fabric layers A1 and A2 according to the present invention A The average single fiber diameter (μm) of the fibers composed of ) is calculated by the following procedure. For measurement, for example, a scanning electron microscope "VHX-D500" manufactured by Keyence Corporation can be used. Hereafter, unless otherwise specified, this device can be used as the scanning electron microscope (SEM) shown in the description of the measurement method. (1) Take 10 small samples randomly from the laminated nonwoven fabric. (2) Surface images are taken using an SEM at a magnification of 500 to 1000x, and the width of 10 polyolefin fibers (10 from each sample, for a total of 100 fibers) is measured. (3) Calculate the average single fiber diameter (μm) from the average of the 100 measured values.

[0034] On the other hand, the polyolefin resin (P) that constitutes the meltblown nonwoven fabric layer B according to the present invention B The fibers made of (P) preferably have an average single fiber diameter of 0.1 μm or more and 8.0 μm or less. BBy setting the average single fiber diameter of the fibers to preferably 0.1 μm or more, more preferably 0.4 μm or more, the fibers can be easily collected when forming the meltblown nonwoven fabric layer, suppressing scattering to the surroundings and resulting in a more uniform laminated nonwoven fabric. On the other hand, by setting the average fiber diameter to preferably 8.0 μm or less, more preferably 7.0 μm or less, the barrier properties of the meltblown nonwoven fabric layer B can be improved, and the water pressure resistance of the laminated nonwoven fabric can be improved.

[0035] Polyolefin resin (P B The average single fiber diameter (μm) of the fibers made up of ) is calculated by the following procedure. (1) Take 10 small samples randomly from the laminated nonwoven fabric. (2) The collected specimens are cut with a freeze microtome, the resulting cross-sections are subjected to conductive treatment, and the cross-sections are photographed using a scanning electron microscope (SEM) at a magnification of 4000 to 10000 times. (3) Measure the width of 10 fibers from each sample's meltblown nonwoven fabric layer B, for a total of 100 fibers. (4) Calculate the average single fiber diameter (μm) from the average of the 100 measured values.

[0036] [Laminated nonwoven fabric] The laminated nonwoven fabric of the present invention has a spunbond nonwoven fabric layer A1 on one surface, which is made of fibers made of polyolefin resin and contains at least a phosphate ester; a spunbond nonwoven fabric layer A2 on the other surface, which is made of fibers made of polyolefin resin; and a meltblown nonwoven fabric layer B, which is made of at least one layer of fibers made of polyolefin resin, between the spunbond nonwoven fabric layer A1 and the spunbond nonwoven fabric layer A2. This configuration provides water resistance and antistatic properties that are at or above the level required for nonwoven fabrics used in chemical protective clothing.

[0037] Furthermore, the structure of the laminated nonwoven fabric of the present invention will be explained with reference to Figure 1. Figure 1 is a cross-sectional conceptual diagram illustrating one embodiment of the laminated nonwoven fabric of the present invention. Figure 1 illustrates a laminated nonwoven fabric (11) in which a spunbond nonwoven fabric layer A1 (12) is disposed on one surface of the laminated nonwoven fabric (11), a spunbond nonwoven fabric layer A2 (14) is disposed on the other surface, and a meltblown nonwoven fabric layer B (13) is disposed between the spunbond nonwoven fabric layer A1 (12) and the spunbond nonwoven fabric layer A2 (14). The fused portion (15) refers to the portion in the laminated nonwoven fabric in which the fibers constituting the spunbond nonwoven fabric layer A1 (12), the spunbond nonwoven fabric layer A2 (14), and the meltblown nonwoven fabric layer B (13) are melted and fused together, and the remaining portion is referred to as the non-fused portion (16) in the present invention. The distinction between spunbond nonwoven fabric layer A1 (12) and spunbond nonwoven fabric layer A2 (14) is determined by the respective thicknesses (t) of the non-fused portion (16). A1 , t A2 The following method is used to measure the thickness of the spunbond nonwoven fabric layer, and the thicker spunbond nonwoven fabric layer will be designated as spunbond nonwoven fabric layer A1(12).

[0038] The spunbond nonwoven fabric layer A1 according to the present invention comprises at least a phosphate ester. Herein, in the present invention, "containing a phosphate ester" means that the fibers constituting the spunbond nonwoven fabric layer contain a phosphate ester, or that a phosphate ester is applied to the surface of the fibers constituting the spunbond nonwoven fabric layer.

[0039] One example of a spunbond nonwoven fabric layer containing phosphate esters in its fibers is when the phosphate esters are kneaded into a polyolefin resin. Another example of a spunbond nonwoven fabric layer having phosphate esters on its surface is when the phosphate esters are applied to the surface of the fibers, more specifically, when the application amount is between 0.01% and 2% by mass relative to the mass of the spunbond nonwoven fabric layer. From the viewpoint of production costs and antistatic properties, the state in which phosphate esters are applied to the surface of the fibers constituting the spunbond nonwoven fabric layer is more preferable.

[0040] Examples of the phosphate esters mentioned above include phosphate esters obtained by reacting (phosphorus pentoxide or phosphorus oxyhalogen) with at least one selected from the group consisting of (alcohol) and (a compound obtained by adding an alkylene oxide having 2 to 4 carbon atoms in a ratio of 1 mole to 10 moles per mole of alcohol), alkali metal salts of phosphate esters, alkaline earth metal salts of phosphate esters, and amine salts of phosphate esters. In particular, if the alcohol is an aliphatic linear alkyl alcohol having 6 to 22 carbon atoms, or an aliphatic alkyl alcohol having a branched structure with 7 to 24 carbon atoms, it is more preferable because it is possible to make a laminated nonwoven fabric with excellent antistatic properties.

[0041] In this invention, by using a phosphate ester, it is possible to impart antistatic properties to a laminated nonwoven fabric while maintaining its water pressure resistance. Generally, antistatic properties can be achieved by applying some hydrophilic substance to a laminated nonwoven fabric. However, when a hydrophilic substance is applied to a laminated nonwoven fabric, the hydrophilic substance may absorb moisture from the air, liquefy, and penetrate into the interior of the laminated nonwoven fabric. Furthermore, if it penetrates to the meltblown layer, which is a functional layer that exhibits barrier properties such as water pressure resistance, it can significantly reduce the water pressure resistance of the laminated nonwoven fabric. This invention has found that by using this phosphate ester, it is possible to obtain a laminated nonwoven fabric that exhibits a certain level of hydrophilicity, exhibits sufficient antistatic properties, and has excellent water resistance.

[0042] The presence of phosphate esters in the spunbond nonwoven fabric layer of the laminated nonwoven fabric of the present invention can be analyzed by extraction tests, elemental analysis, energy-dispersive X-ray spectroscopy, nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy (FT-IR), or by a combination of these methods. For example, in the FT-IR spectrum of the laminated nonwoven fabric obtained by total internal reflection, the phosphate esters are present in the range of 950-1060 cm⁻¹. -1 If a peak originating from the POC bond of a phosphate ester is detected, it is determined that the spunbond nonwoven fabric layer on the surface contains a phosphate ester.

[0043] Specific lamination configurations of the laminated nonwoven fabric of the present invention include, for example, an SMS nonwoven fabric formed by laminating (spunbond nonwoven fabric layer A1) / (meltblown nonwoven fabric layer B) / (spunbond nonwoven fabric layer A2) in order from the surface of the spunbond nonwoven fabric layer A1, and an SMM nonwoven fabric formed by laminating (spunbond nonwoven fabric layer A1) / (meltblown nonwoven fabric layer B) / (meltblown nonwoven fabric layer B) / (spunbond nonwoven fabric layer A2). Examples include S nonwoven fabric, (spunbond nonwoven layer A1) / (spunbond nonwoven layer A1) / (meltblown nonwoven layer B) / (meltblown nonwoven layer B) / (spunbond nonwoven layer A2), or SSMMS nonwoven fabric formed by laminating (spunbond nonwoven layer A1) / (meltblown nonwoven layer B) / (meltblown nonwoven layer B) / (spunbond nonwoven layer A2) / (spunbond nonwoven layer A2).

[0044] In the laminated nonwoven fabric of the present invention, it is preferable that the spunbond nonwoven fabric layer A1 further contains silicone. By doing so, the silicone exhibits appropriate water repellency, suppressing the reduction in water pressure resistance caused by the addition of phosphate esters that exhibit antistatic properties, thereby making it easier to achieve both antistatic properties and high water pressure resistance.

[0045] In this invention, "containing silicone" in the spunbond nonwoven fabric layer A1 means that the fibers constituting the spunbond nonwoven fabric layer A1 contain silicone, or that silicone is applied to the surface of the fibers constituting the spunbond nonwoven fabric layer A1. Furthermore, in this invention, "silicone" refers to a synthetic polymer compound having a main skeleton of siloxane bonds.

[0046] One example of a state in which silicone is contained within the fibers constituting the spunbond nonwoven fabric layer A1 is a state in which the silicone is kneaded into a polyolefin resin. Another example of a state in which silicone is applied to the surface of the fibers constituting the spunbond nonwoven fabric layer A1 is a state in which silicone is applied to the surface of the fibers, more specifically, a state in which 0.01% by mass or more and 2% by mass or less is applied relative to the mass of the spunbond nonwoven fabric layer A1.

[0047] Examples of silicones include amino-modified silicone oil, epoxy-modified silicone oil, carbonyl-modified silicone oil, carbinol-modified silicone oil, polyether-modified silicone oil, amino / alkoxy-modified silicone oil, epoxy / polyether-modified silicone oil, amino / polyether-modified silicone oil, dimethyl silicone oil, and phenyl silicone oil.

[0048] The presence of silicone in the spunbond nonwoven fabric layer A1 of the laminated nonwoven fabric of the present invention can be analyzed by extraction tests, elemental analysis, energy-dispersive X-ray spectroscopy, FT-IR, or a combination thereof. For example, if the surface of a test piece taken from the laminated nonwoven fabric is analyzed using an energy-dispersive X-ray spectrometer and a signal originating from silicon is detected in the resulting fluorescence X-ray spectrum, it can be determined that silicone is present in the spunbond nonwoven fabric layer on the surface.

[0049] The laminated nonwoven fabric of the present invention has a spunbond nonwoven fabric layer A1(t) in the non-fused portion. A1 ) the thickness of the spunbond nonwoven fabric layer A2 (t A2 ) ratio (t A1 / t A2 ) is 1.5 or more and 3.0 or less. The ratio of the thickness t A1 / t A2 By preferably setting this to 1.7 or higher, the decrease in water pressure resistance due to the penetration of antistatic agents such as phosphate esters can be suppressed. On the other hand, the ratio of the thickness t A1 / t A2 By keeping the value below 3.0, it is possible to suppress the occurrence of wrinkles due to shrinkage when creating the fused joint.

[0050] The thickness ratio of the spunbond nonwoven fabric layer in the laminated nonwoven fabric of the present invention is measured as follows. (1) Take a test piece measuring 20 mm wide x 20 mm wide from the laminated nonwoven fabric. (2) The collected specimen is cut with a cryomicrotome, the resulting cross-section is subjected to conductive treatment, and the cross-section is photographed using a SEM at a magnification of 300x. If the SEM image of the cross-section includes a fused area, the observation field is moved and the image is taken again. (3) From the cross-sectional SEM images, the distance from the surface of the spunbond nonwoven fabric layer to the interface of the meltblown nonwoven fabric layer was measured at 5 points for each of the spunbond nonwoven fabric layers A1 and A2, and the average value of each was taken. A1 , t A2 Let's assume that. (4)t A1 to A2 Divide by and round to the second decimal place to get the ratio of thickness t A1 / t A2 Calculate.

[0051] The ratio of the aforementioned thicknesses (t A1 / t A2 This can be controlled by adjusting the basis weight and fiber diameter of each spunbond nonwoven fabric layer.

[0052] In the laminated nonwoven fabric of the present invention, it is preferable that the height H1 of the unfused portion on the surface on which the spunbond nonwoven fabric layer A1 is arranged is 50 μm or more and 200 μm or less, and the ratio (H2 / H1) of the height H2 of the unfused portion on the other surface to H1 is 1.1 or more and 4.0 or less.

[0053] By setting the height H1 to preferably 50 μm or more, the laminated nonwoven fabric becomes more flexible, improving the comfort of the protective clothing and the ease of storage when folding the protective clothing. On the other hand, by setting H1 to preferably 200 μm or less, more preferably 180 μm or less, even more preferably 150 μm or less, and particularly preferably 120 μm or less, the surface becomes smooth, allowing antistatic agents such as phosphate esters to be uniformly applied to the surface, resulting in good antistatic properties.

[0054] Furthermore, by setting the height ratio (H2 / H1) to preferably 1.1 or higher, and more preferably 1.5 or higher, the laminated nonwoven fabric becomes more flexible, improving the comfort of the protective clothing and the ease of storage when folding the protective clothing. By setting H2 / H1 to preferably 4.0 or lower, more preferably 3.0 or lower, and even more preferably 2.0 or lower, deformation of the meltblown nonwoven fabric layer can be suppressed, and water pressure resistance can be improved.

[0055] Furthermore, the height H2 of the non-fused portion on the other surface is preferably 200 μm to 400 μm, as long as it satisfies the above height ratio (H2 / H1). Preferably, setting it to 200 μm or more makes the laminated nonwoven fabric more flexible, improving the comfort of wearing protective clothing and the ease of storing protective clothing when folded. On the other hand, preferably setting it to 400 μm or less, more preferably 370 μm or less, and even more preferably 350 μm or less, can suppress deformation of the meltblown nonwoven fabric layer and improve water pressure resistance.

[0056] In the laminated nonwoven fabric of the present invention, the heights H1 and H2 of the non-fused portion will be explained using the example of the cross-sectional conceptual diagram in Figure 1. In the cross-section of the laminated nonwoven fabric (11), the height difference H1 between the highest point of the non-fused portion and the lowest point of the fused portion on one surface (the surface on the spunbond nonwoven fabric layer A1 (12) side) is the height H1 of the non-fused portion, and the height difference H2 between the highest point of the non-fused portion and the lowest point of the fused portion on the other surface (the surface on the spunbond nonwoven fabric layer A2 (14) side) is the height H2 of the non-fused portion.

[0057] The heights H1 and H2 of the unfused portion in the laminated nonwoven fabric of the present invention, and the ratio of H2 to H1 (H2 / H1), are measured as follows. (1) Take a test piece measuring 20 mm wide x 20 mm wide from the laminated nonwoven fabric. (2) The collected specimen is cut with a freeze microtome so as to include the non-fused portion, the resulting cross-section is subjected to conductive treatment, and the cross-section is photographed using a scanning electron microscope (SEM). (3) From the cross-sectional SEM images, the distance (μm) between the tangent line passing through the lowest point of the fused portion and the tangent line passing through the highest point of the surface of the spunbond nonwoven fabric layer in the non-fused portion was measured at five points for each of the spunbond nonwoven fabric layers A1 and A2, and the value obtained by rounding the first decimal place of the average value (μm) for each layer was defined as H1 (μm) and H2 (μm). (4) Divide H2 by H1 and round to the second decimal place to calculate the ratio of heights (H2 / H1).

[0058] The height of the non-fused portion of the laminated nonwoven fabric can be adjusted by adjusting the basis weight and fiber diameter of the spunbond nonwoven fabric layer. It can also be adjusted by adjusting the engraving shape of the calender roll used in the fusion process described later.

[0059] The thickness (t) of the meltblown nonwoven fabric layer B of the laminated nonwoven fabric of the present invention B The ratio (t) of the total thickness (t) of the laminated nonwoven fabric B The value of / t is preferably 0.05 or more and 0.15 or less. B Water resistance can be improved by setting / t to preferably 0.05 or higher, and more preferably 0.08 or higher. The total thickness of the laminated nonwoven fabric as used herein refers to the distance from the highest point on the surface of the spunbond nonwoven fabric layer A1 in the non-fused portion to the highest point on the surface of the spunbond nonwoven fabric layer A2 in the cross-section of the laminated nonwoven fabric.

[0060] On the other hand, B By setting / t to preferably 0.15 or less, and more preferably 0.12 or less, sufficient strength for use as protective clothing can be obtained.

[0061] The thickness of the meltblown nonwoven fabric layer B in the laminated nonwoven fabric of the present invention (t B The ratio (t) of the total thickness (t) of the laminated nonwoven fabric B / t) is measured as follows: (1) Take a test piece measuring 20 mm wide x 20 mm wide from the laminated nonwoven fabric. (2) The collected specimen is cut with a cryomicrotome, the resulting cross-section is subjected to conductive treatment, and the cross-section is photographed using a SEM at a magnification of 300x. If the SEM image of the cross-section includes a fused area, the observation field is moved and the image is taken again. (3) From the cross-sectional SEM image, the distance from the interface between spunbond nonwoven fabric layer A1 and meltblown nonwoven fabric layer B to the interface between spunbond nonwoven fabric layer A2 and meltblown nonwoven fabric layer B was measured at 5 points, and the average value was used to determine the thickness (t) of meltblown nonwoven fabric layer B. B ) (4) From the cross-sectional SEM image, the distance from the surface of spunbond nonwoven fabric layer A1 to the surface of spunbond nonwoven fabric layer A2 is measured at five points, and the average value is taken as the total thickness (t) of the laminated nonwoven fabric. (5)t B Divide this by t and round the result to the third decimal place to obtain the thickness ratio (t) B Let's assume it's / t).

[0062] t B The / t value can be adjusted by adjusting the basis weight and average single fiber diameter of the meltblown nonwoven fabric layer B. It can also be adjusted by adjusting the bonding temperature, linear pressure, and clearance during the fusion process.

[0063] The basis weight of the laminated nonwoven fabric of the present invention is 40 g / m². 2 More than 100g / m 2 The following is preferable: The basis weight is preferably 40 g / m². 2 The above is sufficient for a comfortable 50g / m² 2 By doing so, it is possible to obtain a laminated nonwoven fabric with water pressure resistance and mechanical strength suitable for practical use.

[0064] On the other hand, the basis weight is preferably 100 g / m². 2 More preferably 70g / m 2 By doing the following, it is possible to create a laminated nonwoven fabric that does not hinder the wearer's work efficiency when used as protective clothing. In addition, the thickness when the protective clothing is folded can be reduced, which reduces the storage space required for stockpiling.

[0065] The basis weight of the laminated nonwoven fabric of the present invention is measured according to the following procedure, in accordance with "6.2 Mass per unit area" of JIS L1913:2010 "General Test Methods for Nonwoven Fabrics". (1) Take three 20cm x 25cm test pieces for every 1m of width of the sample. (2) Weigh the mass (g) of each under standard conditions. (3) The average value is 1m 2 Mass per unit (g / m³) 2 It is represented as ).

[0066] The laminated nonwoven fabric of the present invention has a water pressure resistance of 15 mmH2O / (g / m²) per unit basis weight. 2 It is preferable that the water pressure resistance per unit basis weight be 15 mmH2O / (g / m³). 2 ) More preferably 17 mmH2O / (g / m³) 2 By setting the water pressure resistance to 30 mmH2O / (g / m²), it is possible to create a laminated nonwoven fabric that is highly flexible while maintaining water resistance that is suitable for practical use. There is no particular limit on the upper limit of water pressure resistance, but since a nonwoven fabric structure that exhibits high water pressure resistance has a dense structure, the breathability of the laminated nonwoven fabric decreases, and stuffiness occurs when wearing protective clothing. Therefore, the upper limit of water pressure resistance is 30 mmH2O / (g / m²). 2 ) is preferable.

[0067] The water pressure resistance per unit basis weight of the laminated nonwoven fabric of the present invention is measured according to the following procedure, in accordance with "7.1.1 Method A (low water pressure method)" of JIS L1092:2009 "Test method for waterproofness of textile products". (1) Take five 150mm x 150mm test pieces from the laminated nonwoven fabric. (2) Clamp the test specimen with the measuring device (the part of the test specimen that comes into contact with water should be 100 cm 2 Set it in a container of the appropriate size. (3) Raise the water level of the water-filled leveling device at a speed of 600 mm / min ± 30 mm / min, and measure the water level in millimeters when water comes out from three locations on the back of the test piece. (4) Perform the above measurements on five test pieces and calculate the average value. (5) Divide the calculated ventilation volume (mmH2O) by the basis weight (g / m 2 ) measured by the above method.

[0068] The ventilation volume per unit basis weight of the laminated nonwoven fabric of the present invention is 0.01 (cm 3 / (cm 2 ·sec)) / (g / m 2 ) or more and 5 (cm 3 / (cm 2 ·sec)) / (g / m 2 ) or less, preferably. The ventilation volume per unit basis weight is preferably 2 (cm 3 / (cm 2 ·sec)) / (g / m 2 ) or less, more preferably 1 (cm 3 / (cm 2 ·sec)) / (g / m 2 ) or less, and even more preferably 0.5 (cm 3 / (cm 2 ·sec)) / (g / m 2 ) or less. By doing so, the water resistance required for protective clothing applications can be maintained. On the other hand, the ventilation volume per unit basis weight is preferably 0.02 (cm 3 / (cm 2 ·sec)) / (g / m 2 ) or more, more preferably 0.04 (cm 3 / (cm 2 ·sec)) / (g / m 2 ) or more, and even more preferably 0.06 (cm 3 / (cm 2 ·sec)) / (g / m 2 ) or more. By doing so, the stuffiness during wearing in protective clothing applications can be reduced. The ventilation volume can be adjusted by the basis weight, average single fiber diameter, basis weight of the melt blown nonwoven fabric layer B, and thermocompression bonding conditions (compression ratio, temperature, and linear pressure), etc.

[0069] Incidentally, the ventilation volume per unit basis weight of the laminated nonwoven fabric of the present invention is measured according to the following procedure in accordance with "6.8.1 Frazee method" of JIS L1913:2010 "General test method for nonwoven fabrics". (1) Cut out a test piece of 80 cm × 100 cm from the laminated nonwoven fabric. (2) Measure the pressure at any 20 points on the test specimen using a barometer at 125 Pa. (3) The average of the above 20 points is calculated by rounding to the second decimal place. (4) Calculated airflow rate (cm 3 / (cm 2 (seconds), basis weight (g / m 2 Divide by ).

[0070] [Method for manufacturing laminated nonwoven fabric] Next, preferred embodiments of the method for producing the laminated nonwoven fabric of the present invention will be described in detail.

[0071] The present invention provides a method for manufacturing a laminated nonwoven fabric, which preferably includes the steps of: forming a spunbond nonwoven fabric layer, forming at least one meltblown nonwoven fabric layer thereon, and further forming the spunbond nonwoven fabric layer thereon to form a laminate (step 1); fusing the laminate using a heat embossing roll consisting of a roll with one smooth surface and a roll with an engraved surface on the other to obtain a sheet (step 2); and applying a liquid containing at least a phosphate ester to the surface of the sheet, with the spunbond nonwoven fabric layer on the side in contact with the roll with the smooth surface being designated as spunbond nonwoven fabric layer A1 (step 3).

[0072] (Step 1: A process to form a spunbond nonwoven fabric layer, then form at least one meltblown nonwoven fabric layer on top of it, and then form the spunbond nonwoven fabric layer on top of that to form a laminate.) In this process, the spunbond nonwoven fabric layer and the meltblown nonwoven fabric layer can be formed by the spunbond method and the meltblown method, respectively. As for the method of laminating these to form a laminate, for example, one method is to form a meltblown nonwoven fabric layer by directly depositing fibers formed by the meltblown method onto the first formed spunbond nonwoven fabric layer, and then depositing fibers formed by the spunbond method to form a spunbond nonwoven fabric layer, and so on, by sequentially depositing fibers onto the obtained nonwoven fabric layers to form a laminate. Alternatively, one method is to overlap the separately formed spunbond nonwoven fabric layer and the meltblown nonwoven fabric layer and fuse these nonwoven fabric layers together by heating and pressurizing, or to bond them together with an adhesive such as a hot melt adhesive or a solvent-based adhesive to form a laminate. From the viewpoint of productivity, the method of sequentially depositing fibers onto the obtained nonwoven fabric layers to form a laminate is preferred. The lamination structure is as described above.

[0073] The spunbond nonwoven fabric layer is formed by spinning molten polyolefin resin as long fibers from a spinneret, cooling and stretching the fibers, and then collecting the fibers on a moving net. Alternatively, the stretching may be performed by suction with compressed air using an ejector or the like.

[0074] The spinneret and ejector can be made of various shapes, such as round or rectangular. Among these, a combination of a rectangular spinneret and a rectangular ejector is preferred because it uses relatively little compressed air, is energy-efficient, reduces the likelihood of fusing or friction between yarns, and facilitates yarn opening.

[0075] In this invention, a polyolefin resin is melted in an extruder, weighed, and supplied to a spinneret to be spun out as long fibers. The spinning temperature when melting and spinning the polyolefin resin is preferably 200°C to 270°C, more preferably 210°C to 260°C, and even more preferably 220°C to 250°C. By keeping the spinning temperature within the above range, a stable melt state can be achieved, and excellent spinning stability can be obtained.

[0076] The spun long fibers are cooled, and methods for this cooling include, for example, forcibly blowing cold air onto the fibers, allowing them to cool naturally with the ambient temperature around them, and adjusting the distance between the spinneret and the ejector, or a combination of these methods can be employed. Furthermore, the cooling conditions can be appropriately adjusted considering the discharge rate per single hole of the spinneret, the spinning temperature, and the ambient temperature.

[0077] Next, the cooled and solidified yarn may be stretched by pulling it with compressed air sprayed from an ejector. The spinning speed is preferably 3000 m / min to 6500 m / min, more preferably 3500 m / min to 6500 m / min, and even more preferably 4000 m / min to 6500 m / min. By setting the spinning speed to 3000 m / min to 6500 m / min, high productivity is achieved, and the orientation and crystallization of the fibers are promoted, allowing for the production of high-strength long fibers.

[0078] Next, the obtained long fibers are collected on a moving net, or on an already formed spunbond nonwoven fabric layer or meltblown nonwoven fabric layer placed on a moving net, to form a nonwoven fabric layer. In this invention, it is also preferable to temporarily bond these nonwoven fabric layers to one side of them on the net by contacting them with a hot flat roll. This prevents the surface layer of the nonwoven fabric layer from peeling or being blown away during transport on the net, which would worsen the fabric's structure, and improves transportability from yarn collection to heat-pressing.

[0079] Next, the meltblown nonwoven fabric layer can be formed by employing a known manufacturing method. A polyolefin resin is melted in an extruder and supplied to the die section, and hot air is blown onto the filaments extruded from the die to thin them. Then, the meltblown nonwoven fabric layer is formed on top of an already formed spunbond nonwoven fabric layer or meltblown nonwoven fabric layer placed on a collection net or a moving net. The meltblown method does not require complex processes, fine fibers of several micrometers can be easily obtained, and high water resistance can be achieved.

[0080] (Step 2: A process to obtain a sheet by fusing the laminate using a thermal embossing roll consisting of a roll with a smooth surface on one side and a roll with an engraved surface on the other side.) In this process, a sheet is obtained by fusing materials using a heat-embossed roll consisting of a roll with a smooth surface on one end and a roll with an engraved surface on the other end. This method offers excellent productivity, and the resulting laminated nonwoven fabric is strengthened at the partially fused sections while retaining the texture and feel characteristic of spunbond nonwoven fabric in the non-fused sections.

[0081] As for the surface material of the heat embossing rolls, it is preferable to use a pair of metal rolls in order to obtain a sufficient heat-compression effect and to prevent the engraving (recessed portion) of one embossing roll (engraving roll) from being transferred to the surface of the other roll.

[0082] The embossing adhesion area ratio by the heat embossing roll is preferably 5% to 30%. By setting the adhesion area to preferably 5% or more, more preferably 8% or more, and even more preferably 10% or more, a strength suitable for practical use as a laminated nonwoven fabric can be obtained. On the other hand, by setting the adhesion area to preferably 30% or less, more preferably 25% or less, and even more preferably 20% or less, a suitable flexibility for protective clothing and the like can be obtained.

[0083] In this context, the embossed bonding area ratio refers to the ratio of the area of ​​the fused portion to the total area of ​​the laminated nonwoven fabric. Specifically, when heat bonding is performed using a roll with an uneven surface and a flat roll, it refers to the ratio of the portion of the laminated nonwoven fabric that is in contact with the uneven surface of the roll (the fused portion) to the total area of ​​the laminated nonwoven fabric.

[0084] The shapes of the adhesive areas formed by the heat embossing roll can include circles, ellipses, squares, rectangles, parallelograms, rhombuses, regular hexagons, and regular octagons. Furthermore, it is preferable that the adhesive areas are uniformly located at regular intervals in both the longitudinal direction (conveying direction) and the width direction of the laminated nonwoven fabric. This reduces variations in the strength of the laminated nonwoven fabric.

[0085] In a preferred embodiment, the surface temperature of the heat embossing roll used for fusion is set to -50°C or higher and -15°C or lower relative to the melting point of the polyolefin resin used. By setting the surface temperature of the heat embossing roll to preferably -50°C or higher, and more preferably -45°C or higher, relative to the melting point of the polyolefin resin, a laminated nonwoven fabric with appropriate fusion and strength suitable for practical use can be obtained. Furthermore, by setting the surface temperature of the heat embossing roll to preferably -15°C or lower, and more preferably -20°C or lower, relative to the melting point of the polyolefin resin, excessive fusion can be suppressed, and a laminated nonwoven fabric with appropriate flexibility and processability, particularly suitable for use in protective clothing applications, can be obtained.

[0086] The linear pressure of the heat embossing roll during fusion is preferably 50 N / cm or more and 500 N / cm or less. By setting the linear pressure of the heat embossing roll to preferably 50 N / cm or more, more preferably 100 N / cm or more, and even more preferably 150 N / cm or more, a laminated nonwoven fabric with appropriate fusion and strength suitable for practical use can be obtained. On the other hand, by setting the linear pressure of the heat embossing roll to preferably 500 N / cm or less, more preferably 400 N / cm or less, and even more preferably 300 N / cm or less, a laminated nonwoven fabric with appropriate flexibility and processability, particularly suitable for use in protective clothing, can be obtained.

[0087] Furthermore, in order to adjust the thickness of the laminated nonwoven fabric of the present invention, heat compression can be applied using a thermal calender roll consisting of an upper and lower pair of flat rolls before and / or after the fusion bonding by the thermal embossing roll described above. The upper and lower pair of flat rolls are metal rolls or elastic rolls with no irregularities on the surface of the rolls, and can be used in pairs of metal rolls or metal rolls and elastic rolls.

[0088] Furthermore, an elastic roll here refers to a roll made of a material that has elasticity compared to a metal roll. Examples of elastic rolls include so-called paper rolls such as paper, cotton, and aramid paper, as well as resin rolls made of urethane resin, epoxy resin, silicone resin, polyester resin, hard rubber, and mixtures thereof.

[0089] (Step 3: Of the sheets, the spunbond nonwoven fabric layer on the side of the roll that has a smooth surface that comes into contact with the roll is designated as spunbond nonwoven fabric layer A1, and a liquid containing at least a phosphate ester is applied to its surface.) In this process, the spunbond nonwoven fabric layer on the side of the sheet that has a smooth roll surface in contact with the roll is designated as spunbond nonwoven fabric layer A1, and a liquid containing at least a phosphate ester is applied to the surface of spunbond nonwoven fabric layer A1. By applying the liquid to the smooth surface formed in the previous process, variations in antistatic properties can be suppressed, and a laminated nonwoven fabric with the desired antistatic properties can be obtained.

[0090] Methods for applying a liquid containing at least a phosphate ester to the aforementioned sheet include a roll coating method, gravure coating, flexographic coating, and spray coating method, in which the liquid is transferred to the surface of the laminated nonwoven fabric by winding the solution up from a liquid-filled chemical tank using a metal roll rotating in the chemical tank and bringing the laminated nonwoven fabric into contact with the metal roll. Among these, the roll coating method is preferred because it offers excellent productivity, allows for uniform application of the solution, allows for easy adjustment of the amount of liquid applied, and allows the liquid to be applied to only one side of the laminated nonwoven fabric.

[0091] Furthermore, it is more preferable that the aforementioned liquid (a liquid containing at least a phosphate ester) also contains silicone. This allows for the maintenance of higher water pressure resistance.

[0092] Furthermore, this liquid can be used in various forms, such as a solution or emulsion, depending on the properties of the phosphate ester and other components.

[0093] After applying the aforementioned liquid, it is preferable to dry the solvent contained in the solution. Methods for drying include drying with hot air and infrared radiation, or drying by contacting a heat source.

[0094] [Protective clothing] In the protective clothing of the present invention, it is preferable that the laminated nonwoven fabric is used at least on the front of the garment. By using the laminated nonwoven fabric at least on the front of the garment, the wearer's body can be protected from harmful mist and airborne dust.

[0095] Examples of protective clothing according to the present invention include a full-body chemical protective suit with a structure for protecting the wearer from spray-type liquid chemicals, as described in "4.5 Sealed suit for spray protection (Type 4)" of JIS T8115:2015 "Chemical protective clothing", a full-body chemical protective suit with a structure for protecting the wearer from airborne solid dust, as described in "4.6 Sealed suit for airborne solid dust protection (Type 5)", and a full-body chemical protective suit with a structure for protecting the wearer from mist-type liquid chemicals, as described in "4.7 Sealed suit for mist protection (Type 6)". The protective clothing may take the form of a one-piece coverall or a two-piece suit, and may include a hood, visor, or booties depending on the desired configuration. Other examples include biohazard protection suits that protect the entire body or most of the body, including the hands, feet, and head, as described in "3.2 Biohazard Protection Suits" of JIS T8122:2015 "Protective Clothing for Biological Hazards," and non-airtight, non-positive-pressure biohazard protection suits that protect the wearer from liquid or suspended solid dust biological hazards, as described in "3.5 Sealed Suits."

[0096] Furthermore, in the case of a chemical protective suit of the present invention that has a structure that protects a part of the body, for example, a chemical protective suit of the structure that protects a part of the body as described in "4.8 Partial chemical protective suit (Type PB)" of JIS T8115:2015 "Chemical protective suit", such as an apron, footwear cover, gown, hood, jacket, lab coat, arm cover, smock, etc., it is preferable that 80% to 100% of its mass is the aforementioned laminated nonwoven fabric. Even in this case, the area to be worn can be effectively protected from harmful mist and airborne dust.

[0097] Alternatively, even if the protective suit is a biohazard-resistant protective suit with a structure that protects only a part of the body, such as a partial protective suit described in "3.6 Biohazard-resistant full-body protective suit" of JIS T8122:2015 "Protective suit against biological hazardous substances," which includes gowns, surgical gowns, lab coats, jackets, trousers, aprons, etc., that protects the torso of the body from penetration by biological hazardous substances, or even a partial protective device described in "3.7 Biohazard-resistant full-body protective suit" of JIS T8122:2015 "Protective suit against biological hazardous substances," which includes a cap, shoe cover, arm cover, etc., that protects a part of the body from penetration by biological hazardous substances, it is preferable that 80% to 100% of its mass is the aforementioned laminated nonwoven fabric. In this case as well, the area of ​​wear can be effectively protected from harmful mist and airborne dust.

[0098] The protective clothing of the present invention can be manufactured by known methods. [Examples]

[0099] The laminated nonwoven fabric of the present invention will be described in detail based on the examples. Unless otherwise specified, the measurements of each physical property were performed according to the method described above.

[0100] (1) MFR of polyolefin resin (g / 10 min): The MFR of polyolefin resins (A) and (B) was measured under the conditions of a load of 2.16 kg and a temperature of 230°C for polypropylene resins, and under the conditions of a load of 2.16 kg and a temperature of 190°C for polyethylene resins.

[0101] (2) Basis weight (g / m²) of spunbond nonwoven layers A1 and A2, meltblown nonwoven layer B, and laminated nonwoven fabric 2 ) The basis weights of the spunbond nonwoven fabric layers A1, A2, and the meltblown nonwoven fabric layer B were measured by the above method from nonwoven fabric layers separately collected on a collection net under the same conditions as the following (spunbond nonwoven fabric layer A1), (spunbond nonwoven fabric layer A2), and (meltblown nonwoven fabric layer B). The basis weight of the laminated nonwoven fabric was measured by the above method.

[0102] (3) Average single fiber diameter (μm) of the spunbond nonwoven fabric layers A1, A2, and the meltblown nonwoven fabric layer B Measured by the above method using "VHX-D500" manufactured by KEYENCE CORPORATION as a scanning electron microscope.

[0103] (4) Thickness (t A1 , t A2 , t B , t (μm)) of the spunbond nonwoven fabric layers A1, A2, the meltblown nonwoven fabric layer B, and the laminated nonwoven fabric Measured by the above method using "VHX-D500" manufactured by KEYENCE CORPORATION as a scanning electron microscope.

[0104] (5) Heights H1, H2 of the non-fused parts and ratio of heights (H2 / H1) Measured by the above method using "VHX-D500" manufactured by KEYENCE CORPORATION as a scanning electron microscope.

[0105] (6) Water pressure resistance per unit basis weight of the laminated nonwoven fabric ((mmH2O) / (g / m 2 ...)): "Hydrotester" (FX-3000-IV type) manufactured by TEXTEST AG, Switzerland was used as a water pressure resistance tester. The calculated water pressure resistance (mmH2O) was rounded to the second decimal place from the following formula based on the basis weight (g / m 2 ... ) obtained by the above method to calculate the water pressure resistance per unit basis weight. Water pressure resistance per unit basis weight = Water pressure resistance (mmH2O) / Basis weight (g / m 2 ...). [[ID=三十九]]

[0106] (7) Surface electrical resistance (Ω) of the laminated nonwoven fabric The surface electrical resistance of the laminated nonwoven fabric was measured in accordance with the European standard (EN1149-1:2006) using an ADC Digital Ultra-High Resistance / Microcurrent Meter 8340A, following the procedure below. A. Take 10 test pieces measuring 10cm x 10cm from the laminated nonwoven fabric. B. Set the test specimen so that one side is in contact with the measuring part of the device, apply a voltage of 100V, and record the surface electrical resistance value after 15 seconds. C. Similarly, record the surface electrical resistance on the other side of the test specimen, and use the smaller value as the surface electrical resistance value of that specimen. D. Measurements were taken for the above 10 sheets, the average value was calculated, and the surface electrical resistance was determined to two significant figures.

[0107] (8) Air permeability per unit basis weight of laminated nonwoven fabric (cm 3 / (cm 2 ·sec)) / (g / m 2 )): The ventilation rate was measured based on the method described above. 3 / (cm 2 The weight (g / m²) obtained based on the above method is calculated using the following method. 2 From this, the amount of air per unit area was calculated by rounding to the third decimal place using the following formula. Airflow rate per unit area = Airflow rate (cm²) 3 / (cm 2 (g / m²) 2 ).

[0108] [Method for preparing coating solution] [Coating liquid A] To 1940 g of pure water at room temperature, 58.8 g of sodium lauryl phosphate (CAS registry number: 50957-96-5) and 1.2 g of silicone oil (Shin-Etsu Chemical Co., Ltd. "KF-96-10CS") were added and mixed by stirring under atmospheric pressure to obtain coating solution A.

[0109] [Coating fluid B] Coating solution B was obtained in the same manner as coating solution A, except that silicone oil was omitted from coating solution A.

[0110] [Coating liquid C] Coating solution C was obtained in the same manner as coating solution A, except that sodium lauryl phosphate was omitted from coating solution A.

[0111] [Example 1] (Spunbond nonwoven fabric layer A1) A polypropylene resin consisting of a homopolymer with an MFR of 200 g / 10 min and a melting point of 163°C was melted in an extruder and spun through a rectangular die with a hole diameter of φ0.30 mm and a hole depth of 2 mm at a spinning temperature of 235°C and a single-hole discharge rate of 0.40 g / min. After the spun yarn was cooled and solidified, it was pulled and stretched in a rectangular ejector using compressed air at an ejector pressure of 0.35 MPa, collected on a moving net, and obtained polypropylene long fibers with a basis weight of 33 g / m². 2 A spunbond nonwoven fabric layer A1 was formed. The average single fiber diameter of the fibers constituting the formed spunbond nonwoven fabric layer A1 was 11.2 μm.

[0112] (Meltblown nonwoven fabric layer B) A polypropylene resin consisting of homopolymer with an MFR of 1100 g / min was melted in an extruder and spun through a die with a pore diameter of φ0.25 mm at a spinning temperature of 260°C and a single-hole discharge rate of 0.10 g / min. Subsequently, air was injected onto the yarn under conditions of an air temperature of 290°C and an air pressure of 0.10 MPa, and the resulting material was collected on the spunbond nonwoven fabric layer A1 to form a meltblown nonwoven fabric layer B. The basis weight of the meltblown nonwoven fabric layer B is 10 g / m². 2 The average single fiber diameter was 1.1 μm.

[0113] (Spunbond nonwoven fabric layer A2) Under conditions where a spunbond nonwoven fabric layer A1 was formed on top of the aforementioned melt-blown nonwoven fabric layer B, the single-hole discharge rate was changed to 0.20 g / min to collect polypropylene long fibers, resulting in a basis weight of 17 g / m². 2 A spunbond nonwoven fabric layer A2 was formed. The basis weight of the spunbond nonwoven fabric layer A2 was 17 g / m². 2 The average single fiber diameter of the constituent fibers was 8.7 μm.

[0114] (Laminated nonwoven fabric) By the method described above, the total basis weight is 60 g / m². 2 A laminated fiber web was obtained by laminating a spunbond nonwoven fabric layer A1, a meltblown nonwoven fabric layer B, and a spunbond nonwoven fabric layer A2. Next, the obtained laminated fiber web was heat-bonded using a pair of upper and lower heat embossing rolls, the upper roll being a metal embossing roll with a polka-dot pattern engraved on it and an adhesive area ratio of 16%, and the lower roll being a metal flat roll, under conditions of a linear pressure of 300 N / cm and a heat bonding temperature of 130°C. Coating liquid A was applied to the lower layer of the heat-bonded laminated fiber web using a metal roll rotating at 10% of the web transport speed in a chemical tank, and volatile components were removed by passing it through a dryer set to 120°C for 1 second to obtain a laminated nonwoven fabric. The results are shown in Table 1.

[0115] [Example 2] In Example 1, the single-hole discharge rate for (spunbond nonwoven fabric layer A1) was changed from 0.40 g / min to 0.45 g / min, and in (spunbond nonwoven fabric layer A2), the single-hole discharge rate was changed from 0.20 g / min to 0.15 g / min. Otherwise, a laminated nonwoven fabric was obtained in the same manner as in Example 1. The results are shown in Table 1.

[0116] [Example 3] In Example 1, the single-hole discharge rate for (spunbond nonwoven fabric layer A1) was changed from 0.40 g / min to 0.36 g / min, and in Example 1, the single-hole discharge rate for (spunbond nonwoven fabric layer A2) was changed from 0.20 g / min to 0.24 g / min. Otherwise, a laminated nonwoven fabric was obtained in the same manner as in Example 1. The results are shown in Table 1.

[0117] [Example 4] In Example 1 (laminated nonwoven fabric), coating solution A was applied, but the coating solution was changed to B. Otherwise, a laminated nonwoven fabric was obtained in the same manner as in Example 1. The results are shown in Table 1.

[0118] [Example 5] In Example 1, a laminated nonwoven fabric was obtained in the same manner as in Example 1, except that the movement speed of the fiber-collecting net was changed to 1.5 times that of Example 1 in (spunbond nonwoven fabric layer A1), (meltblown nonwoven fabric layer B), and (spunbond nonwoven fabric layer A2). The results are shown in Table 1.

[0119] [Example 6] In Example 1 (meltblown nonwoven fabric layer B), the single-hole discharge rate was changed from 0.10 g / min to 0.05 g / min, but otherwise a laminated nonwoven fabric was obtained in the same manner as in Example 1. The results are shown in Table 2.

[0120] [Example 7] In Example 1 (laminated nonwoven fabric), a pair of upper and lower heat embossing rolls were used, consisting of an upper roll made of metal with a polka dot pattern engraved and an adhesive area ratio of 16%, and a lower roll made of metal flat roll. A laminated nonwoven fabric was obtained in the same manner as in Example 1, except that the upper roll was changed to a metal flat roll and the lower roll to a metal embossing roll with a polka dot pattern engraved and an adhesive area ratio of 16%. The results are shown in Table 2.

[0121] [Example 8] In Example 7 (meltblown nonwoven fabric layer B), the single-hole discharge rate was changed from 0.10 g / min to 0.05 g / min, but otherwise a laminated nonwoven fabric was obtained in the same manner as in Example 7. The results are shown in Table 2.

[0122] [Comparative Example 1] In Example 1, the single-hole discharge rate for (spunbond nonwoven fabric layer A1) was changed from 0.40 g / min to 0.30 g / min, and in (spunbond nonwoven fabric layer A2), the single-hole discharge rate was changed from 0.20 g / min to 0.30 g / min. Otherwise, a laminated nonwoven fabric was obtained in the same manner as in Example 1. The results are shown in Table 3.

[0123] [Comparative Example 2] In Example 1, the single-hole discharge rate for (spunbond nonwoven fabric layer A1) was changed from 0.40 g / min to 0.48 g / min, and in Example 1, the single-hole discharge rate for (spunbond nonwoven fabric layer A2) was changed from 0.20 g / min to 0.12 g / min. Otherwise, a laminated nonwoven fabric was obtained in the same manner as in Example 1. The results are shown in Table 3.

[0124] [Comparative Example 3] In Example 1, a laminated nonwoven fabric was obtained in the same manner as in Example 1, except that the meltblown nonwoven fabric layer B was not formed. The results are shown in Table 3.

[0125] [Comparative Example 4] In Example 1 (laminated nonwoven fabric), coating solution A was applied, but a laminated nonwoven fabric was obtained in the same manner as in Example 1, except that it was changed to coating solution C. The results are shown in Table 3.

[0126] [Comparative Example 5] In Example 1 (laminated nonwoven fabric), when coating solution A was applied, a laminated nonwoven fabric was obtained in the same manner as in Example 1, except that coating solution was not applied. The results are shown in Table 3.

[0127] [Table 1]

[0128] [Table 2]

[0129] [Table 3]

[0130] The laminated nonwoven fabrics of Examples 1 to 8 contain a phosphate ester in the spunbond nonwoven fabric layer A1, and the thickness of the spunbond nonwoven fabric layer A1 is (t A1 ) the thickness of the spunbond nonwoven fabric layer A2 (t A2 ) ratio (t A1 / t A2The ratio is between 1.5 and 3, and the water pressure resistance per unit basis is 15 mmH2O / (g / m³). 2 It possessed superior water resistance.

[0131] On the other hand, the laminated nonwoven fabric of Comparative Example 1 is t A1 / t A2 The ratio was less than 1.5, indicating poor water resistance. Furthermore, the laminated nonwoven fabric of Comparative Example 2 was t A1 / t A2 The water pressure resistance was poor because the melt-blown nonwoven fabric layer B was damaged during the lamination process, exceeding 3. The laminated nonwoven fabric of Comparative Example 3 did not contain the melt-blown nonwoven fabric layer B, so its water pressure resistance was low. The laminated nonwoven fabrics of Comparative Examples 4 and 5 did not contain phosphate ester in the spunbond nonwoven fabric layer, so their surface electrical resistance was high and their antistatic performance was low. [Explanation of symbols]

[0132] 11: Laminated nonwoven fabric 12: Spunbond nonwoven fabric layer A1 13: Meltblown nonwoven fabric layer B 14: Spunbond nonwoven fabric layer A2 15: Fusion part 16: Non-fused part

Claims

1. On one surface, a spunbond nonwoven fabric layer A1 is disposed, which is composed of fibers made of polyolefin resin and contains at least a phosphate ester. On the other surface, a spunbond nonwoven fabric layer A2 made of fibers from a polyolefin resin is disposed. A laminated nonwoven fabric is provided, wherein a meltblown nonwoven fabric layer B, composed of at least one layer of polyolefin resin fibers, is disposed between the spunbond nonwoven fabric layer A1 and the spunbond nonwoven fabric layer A2, The thickness (t) of the spunbond nonwoven fabric layer A1 in the non-fused portion of the laminated nonwoven fabric. Ａ１ The thickness (t) of the spunbond nonwoven fabric layer A2. Ａ２ ) ratio (t Ａ１ / t Ａ２ ) is between 1.5 and 3.0, A laminated nonwoven fabric wherein the height H1 of the unfused portion on one surface is 50 μm or more and 200 μm or less, and the ratio of the height H2 of the unfused portion on the other surface to the height H1 (H2 / H1) is 1.1 or more and 4.0 or less.

2. The laminated nonwoven fabric according to claim 1, wherein the spunbond nonwoven fabric layer A1 further contains silicone.

3. The thickness (t) of the meltblown nonwoven fabric layer B. Ｂ The ratio (t) of the total thickness (t) of the laminated nonwoven fabric Ｂ The laminated nonwoven fabric according to claim 1, wherein the ratio of / t is 0.05 or more and 0.15 or less.

4. A method for manufacturing a laminated nonwoven fabric according to claim 1, comprising the steps of forming a spunbond nonwoven fabric layer, forming at least one meltblown nonwoven fabric layer thereon, and further forming a spunbond nonwoven fabric layer thereon to form a laminate, The process of obtaining a sheet involves fusing the laminate using a thermal embossing roll consisting of a roll with a smooth surface on one side and a roll with an engraved surface on the other side. Of the aforementioned sheets, the spunbond nonwoven fabric layer on the side of the roll that has a smooth surface and is in contact with the roll is designated as spunbond nonwoven fabric layer A1, and the surface of spunbond nonwoven fabric layer A1 contains at least a phosphate ester. The process of applying liquid, A method for manufacturing laminated nonwoven fabrics, including the method described above.

5. The method for producing a laminated nonwoven fabric according to claim 4, wherein the liquid further contains silicone.

6. A protective suit comprising the laminated nonwoven fabric described in claim 1, with at least the front garment being made of it.

7. A protective suit in which 80% to 100% of the mass is the laminated nonwoven fabric described in claim 1.

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