JPWO2019167853A1 - Laminated non-woven fabric - Google Patents

Abstract

The present invention provides a nonwoven fabric made of fibers made of a polyolefin resin, which has both water resistance and flexibility, and has excellent processability. The present invention is a laminated non-woven fabric in which a spunbonded non-woven fabric layer and a melt-blown non-woven fabric layer are laminated, and the spunbonded nonwoven fabric layer is composed of composite fibers made of a thermoplastic resin (A1) and a polyethylene-based resin (A2). The thermoplastic resin (A1) is a polyolefin resin (A1a) or a polyester resin (A1b), the melt-blown nonwoven fabric layer is composed of fibers made of the polyolefin resin (B), and further, the spunbond The average single fiber diameter of the composite fibers of the non-woven fabric layer is 6.5 to 11.9 μm, and the complex viscosity of the spunbonded non-woven fabric layer measured under the conditions of 230 ° C. and 6.28 rad / sec is 100 Pa · sec. The following relates to laminated non-woven fabrics.

Description

In the present invention, the laminated non-woven fabric of the present invention is formed by laminating a spunbonded non-woven fabric layer composed of composite fibers and a melt-blown non-woven fabric layer, and is excellent in water resistance and flexibility, and is excellent in moldability as a building material application. It relates to a laminated non-woven fabric.

In recent years, non-woven fabrics have been used for various purposes and are expected to grow in the future. Nonwoven fabrics are used in a wide range of applications such as industrial materials, civil engineering materials, building materials, living materials, agricultural materials, sanitary materials, and medical materials.

Building materials are attracting attention as non-woven fabrics. In recent years, in the construction of wooden houses and the like, a ventilation layer construction method in which a ventilation layer is provided between the outer wall material and the heat insulating material and the moisture that has entered the wall is released to the outside through the ventilation layer has become widespread. This ventilation layer construction method is a spunbonded non-woven fabric as a house wrap material that is a moisture-permeable waterproof sheet that has both water resistance to prevent rainwater from entering from the outside of the building and moisture permeability to release the moisture generated inside the wall to the outside. Is used.

The spunbonded non-woven fabric is characterized by being excellent in moisture permeability due to its structure, but has a problem of being inferior in water resistance. Therefore, the spunbonded non-woven fabric is laminated and integrated with a film having excellent water resistance to form a moisture-permeable waterproof sheet, which is used as a house wrap material.

The house wrap material is fixed to the base with a spelling needle (also called a tucker needle or staple), and has excellent long-term durability and weather resistance under high and low temperature conditions, and can withstand long-term use. It is required to have durability (hydrolysis resistance) and excellent moldability at the time of construction.

Conventionally, as a moisture-permeable waterproof sheet used for such a house wrap material, in order to improve the balance between moisture permeability and water resistance, a polyester non-woven fabric having a single fiber diameter of 3 to 28 microns and a grain size of 5 to 50 g / m ² Has been proposed as a house wrap material in which a film having a thickness of 7 to 60 microns is laminated on this non-woven fabric, which is made of a block copolymerized polyester having a hard segment and a soft segment (see Patent Document 1).

Japanese Patent No. 3656837

However, the conventional house wrap material has a problem that the sheet is hard and inferior in moldability because it is a laminated body of a non-woven fabric and a film. The hardness of the sheet is due to the film, and reducing the proportion of the film to be bonded is an effective means, but there is a limit to reducing the proportion of the film from the viewpoint of water resistance.

Therefore, an object of the present invention has been made in view of the above circumstances, and the object has both water resistance and high flexibility even without a conventionally used film, and further, heat adhesion and the like. It is an object of the present invention to provide a non-woven fabric having excellent moldability.

As a result of diligent studies to achieve the above object, the present inventors have made a spunbonded nonwoven fabric layer composed of fibers made of two or more different types of polyolefin resins and fibers made of polyolefin resin. Finding that by using a laminated non-woven fabric in which a melt-blown non-woven fabric layer is laminated and appropriately controlling the fluidity of the fibers constituting each non-woven fabric layer, it is possible to have high flexibility and improve the mechanical properties of the laminated non-woven fabric. Got Furthermore, it has also been found that this laminated non-woven fabric makes it possible to provide the desired high level of water resistance, flexibility, and workability mainly with thermal adhesiveness.

The present invention has been completed based on these findings, and the following inventions are provided according to the present invention.

The laminated non-woven fabric of the present invention is a laminated non-woven fabric in which a spunbonded non-woven fabric layer and a melt-blown non-woven fabric layer are laminated, and the spunbonded non-woven fabric layer is a composite composed of a thermoplastic resin (A1) and a polyethylene-based resin (A2). The thermoplastic resin (A1) is composed of fibers, the thermoplastic resin (A1) is a polyolefin resin (A1a) or a polyester resin (A1b), and the melt-blown nonwoven fabric layer is composed of fibers made of a polyolefin resin (B). The average single fiber diameter of the composite fibers of the spunbonded nonwoven fabric layer is 6.5 to 11.9 μm, and the complex viscosity of the spunbonded nonwoven fabric layer measured under the conditions of 230 ° C. and 6.28 rad / sec is 100 Pa. It is less than or equal to sec.

According to the preferred mode of the laminated nonwoven fabric of the present invention, the water pressure resistance per unit basis weight is 15 mmH ₂ O / (g / m ² ) or more.

According to the preferred mode of the laminated nonwoven fabric of the present invention, the melt flow rate of the fiber made of the polyolefin resin (A1) is 155 to 850 g / 10 minutes.

According to the preferred mode of the laminated nonwoven fabric of the present invention, the content of the melt-blown nonwoven fabric layer is 1% by mass or more and 15% by mass or less with respect to the mass of the laminated nonwoven fabric.

According to the preferred mode of the laminated nonwoven fabric of the present invention, the surface roughness SMD by the KES method on at least one side is 1.0 to 2.6 μm.

According to the preferred mode of the laminated nonwoven fabric of the present invention, the average friction coefficient MIU by the KES method on at least one side is 0.1 to 0.5.

According to the preferred mode of the laminated non-woven fabric of the present invention, the fluctuation MMD of the average friction coefficient by the KES method on at least one side is 0.008 or less.

According to the preferred mode of the laminated nonwoven fabric of the present invention, the polyolefin resin (A2) contains a fatty acid amide compound having 23 or more and 50 or less carbon atoms.

According to the preferred mode of the laminated nonwoven fabric of the present invention, the amount of the fatty acid amide compound added is 0.01 to 5.0% by mass.

According to the preferred embodiment of the laminated nonwoven fabric of the present invention, the fatty acid amide compound is ethylene bisstearic acid amide.

According to the present invention, a polyethylene-based resin, a spunbonded nonwoven fabric layer composed of composite fibers made of a polyolefin-based or polyester-based resin, and a melt-blown nonwoven fabric layer composed of fibers made of a polyolefin-based resin are laminated. A laminated non-woven fabric having excellent water resistance and flexibility and excellent processability can be obtained. From these characteristics, the laminated non-woven fabric of the present invention can be suitably used particularly as a building material application such as a moisture permeable waterproof sheet.

Since the laminated non-woven fabric of the present invention has excellent water resistance, it is possible to reduce the basis weight when used as a moisture-permeable waterproof sheet as compared with the conventional laminated non-woven fabric.

Further, the weight of the film to be bonded can be reduced for the purpose of water resistance, and it can also be used in applications requiring high water resistance, which is difficult to apply with conventional laminated non-woven fabrics.

Further, since it is excellent in flexibility, when it is used as a building material, wrinkles are less likely to occur especially in the process of bonding, and the moldability is improved.

FIG. 1 is a schematic cross-sectional view illustrating a cross section of a composite fiber constituting the nonwoven fabric of the present invention. FIG. 2 is a schematic cross-sectional view illustrating a cross section of another composite fiber constituting the nonwoven fabric of the present invention. FIG. 3 is a schematic cross-sectional view illustrating a cross section of another composite fiber constituting the nonwoven fabric of the present invention.

The laminated non-woven fabric of the present invention is a laminated non-woven fabric in which a spunbonded non-woven fabric layer and a melt-blown non-woven fabric layer are laminated, and the spunbonded non-woven fabric layer is a composite composed of a thermoplastic resin (A1) and a polyethylene-based resin (A2). The thermoplastic resin (A1) is composed of fibers, the thermoplastic resin (A1) is a polyolefin resin (A1a) or a polyester resin (A1b), and the melt-blown nonwoven fabric layer is composed of fibers made of a polyolefin resin (B). The average single fiber diameter of the composite fibers of the spunbonded non-woven fabric layer is 6.5 to 11.9 μm, and the complex viscosity of the laminated non-woven fabric measured under the conditions of 230 ° C. and 6.28 rad / sec is 100 Pa · sec or less. It is a laminated non-woven fabric. The details will be described below.

[Thermoplastic resin (A1), (A2), polyolefin resin (B)]
Among the laminated non-woven fabrics of the present invention, a thermoplastic resin (A1) and a polyethylene-based resin (A2) are used for the composite fibers constituting the spunbonded non-woven fabric layer.

Of these, as the thermoplastic resin (A1), a polyolefin-based resin (A1a) or a polyester-based resin (A1b) is used.

As the polyolefin-based resin (A1a), a polyolefin containing an olefin having 2 to 10 carbon atoms is preferably used. Specifically, ethylene, propylene, 1-butene, 1-pentene, 1-hexane, 4-methyl-1-pentene, 1-octene, and copolymers of these monomers and other α-olefins are used. Can be mentioned. These can be used alone or in combination of two or more. Among them, polypropylene-based resin is preferably used because it has high strength and excellent dimensional stability during production of sanitary materials.

When the polypropylene-based resin is used for the polyolefin-based resin (A1a) used in the present invention, the proportion of the homopolymer of propylene is preferably 60% by mass or more, more preferably 70% by mass or more, and further preferably. Is 80% by mass or more. Within the above range, good spinnability can be maintained and strength can be improved.

Further, as the polyester resin (A1b), a polyester composed of an acid component and an alcohol component is used. As the acid component, for example, aromatic carboxylic acids such as terephthalic acid, isophthalic acid and phthalic acid, aliphatic dicarboxylic acids such as adipic acid and sebacic acid, and alicyclic dicarboxylic acids such as cyclohexanecarboxylic acid may be used. it can. Further, as the alcohol component, ethylene glycol, diethylene glycol, polyethylene glycol and the like can be used.

Examples of the polyester-based resin include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polylactic acid and polybutylene succinate, and copolymers thereof. By doing so, the strength of the laminated non-woven fabric can be further improved, and when used for house wrap, the fastening strength with staples can be improved. Above all, it is preferable to use polyethylene terephthalate because high mechanical properties can be obtained.

On the other hand, examples of the polyethylene-based resin (A2) used in the present invention include a homopolymer of ethylene or a copolymer of ethylene and various α-olefins. Examples of the polyethylene-based resin (A2) include medium-density, high-density and linear low-density polyethylene (hereinafter, may be referred to as LLDPE), etc., and are excellent in spinnability. , LLDPE is preferably used.

The polyethylene-based resin used in the present invention may be a mixture of two or more kinds, and may be a branching component different from ethylene, for example, α- such as butene, hexene, 4-methylpentene, heptene, and octene. A polyethylene-based resin obtained by copolymerizing an olefin or a resin composition containing a thermoplastic elastomer or the like can also be used.

The polyethylene-based resin used in the present invention includes commonly used antioxidants, weather stabilizers, light-resistant stabilizers, antistatic agents, antifoaming agents, blocking inhibitors, lubricants, as long as the effects of the present invention are not impaired. Additives such as nucleating agents and pigments, or other polymers can be added as needed.

Further, when spinning the fiber described later, this resin is decomposed with respect to the resin used in order to prevent the occurrence of partial viscosity unevenness, make the fineness of the fiber uniform, and further reduce the fiber diameter as described later. It is also conceivable to adjust the MFR. However, for example, it is preferable not to add a peroxide, particularly a free radical agent such as a dialkyl peroxide. When this method is used, viscosity spots are partially generated and the fineness becomes non-uniform, making it difficult to sufficiently reduce the fiber diameter. In addition, when the spinnability deteriorates due to viscosity spots and air bubbles caused by decomposition gas. There is also.

The melting point of the polyethylene-based resin used in the present invention is preferably 80 to 160 ° C, more preferably 100 to 140 ° C. By setting the melting point to preferably 80 ° C. or higher, more preferably 100 ° C. or higher, it becomes easy to obtain heat resistance that can withstand practical use. Further, by setting the melting point to preferably 160 ° C. or lower, more preferably 140 ° C. or lower, it becomes easy to firmly adhere to the polypropylene resin and it becomes easy to spin without breaking the yarn.

Further, as the polyolefin-based resin (B) of the fibers constituting the melt-blown non-woven fabric layer, a polyolefin containing an olefin having 2 to 10 carbon atoms is preferably used as in the above-mentioned polyolefin-based resin (A1a). Among them, polypropylene-based resin is preferably used because it has high strength and excellent dimensional stability during production of sanitary materials.

The flow characteristics of the thermoplastic resin (A1) and polyolefin resin (A2) of the composite fibers constituting the spunbonded nonwoven fabric layer and the polyolefin resin (B) of the fibers constituting the melt-blown nonwoven fabric layer according to the present invention. As the melt flow rate (sometimes abbreviated as MFR) indicating, the value measured by ASTM D1238 (method A) is adopted.

According to the above standard, for example, polypropylene is measured at a load of 2.16 kg and a temperature of 230 ° C., and polyethylene is measured at a load of 2.16 kg and a temperature of 190 ° C. Further, in the present invention, the measurement conditions for polyester are a load of 2.16 kg and measurement at 280 ° C.

First, the MFR of the thermoplastic resin (A1) of the fibers constituting the spunbonded non-woven fabric layer is preferably 155 to 850 g / 10 minutes. By setting the MFR to 155 to 850 g / 10 minutes, more preferably 155 to 600 g / 10 minutes, and further preferably 155 to 400 g / 10 minutes, the fiber thinning behavior when spinning the spunbonded non-woven fabric layer can be obtained. Stable spinning is possible even if the yarn is stretched at a high spinning speed in order to be stable and increase productivity. In addition, by stabilizing the thinning behavior, thread sway is suppressed, and unevenness when collecting in the form of a sheet is less likely to occur. Further, since it is possible to draw the fiber stably and at a high spinning speed, the orientation and crystallization of the fiber can be promoted to obtain a fiber having high mechanical strength.

It is also conceivable to adjust the MFR of the thermoplastic resin by blending two or more kinds of resins having different MFRs at an arbitrary ratio. However, in this case, the MFR of the resin to be blended with respect to the main thermoplastic resin is preferably 10 to 1000 g / 10 minutes, more preferably 20 to 800 g / 10 minutes, still more preferably 30 to 600 g / min. It is 10 minutes. Within the above range, it is possible to prevent the blended thermoplastic resin from having partial viscosity spots, resulting in non-uniform fineness and deterioration of spinnability.

The melt flow rate (MFR) of the polyethylene resin (A2) used in the present invention is preferably 50 to 200 g / 10 minutes. The MFR was preferably 50 to 200 g / 10 minutes, more preferably 60 to 180 g / 10 minutes, still more preferably 70 to 150 g / 10 minutes, and stretched at a high spinning rate to increase productivity. Even so, since the viscosity is low, it can easily follow the deformation, and stable spinning becomes possible. Further, by drawing at a high spinning speed, the orientation and crystallization of the fiber can be promoted to obtain a fiber having high mechanical strength.

It is also conceivable to adjust the MFR of the polyethylene-based resin (A2) by blending two or more kinds of resins having different MFRs at an arbitrary ratio. However, in this case, the MFR of the resin to be blended with the main polyethylene-based resin is preferably 10 to 1000 g / 10 minutes, more preferably 10 to 800 g / 10 minutes, and further preferably 10 to 600 g / min. It is 10 minutes. By setting the above range, it is possible to prevent the blended polyethylene resin (A2) from having partial viscosity spots, resulting in non-uniform fineness and deterioration of spinnability.

Further, the MFR of the polyolefin resin (B) of the fibers constituting the melt-blown non-woven fabric layer is preferably 200 to 2500 g / 10 minutes. By setting the MFR to preferably 200 to 2500 g / 10 minutes, more preferably 400 to 2000 g / 10 minutes, and further preferably 600 to 1500 g / 10 minutes, stable spinning can be easily performed and the MFR is at a level of several μm. A fiber made of a polyolefin resin (B) can be obtained.

In the laminated non-woven fabric of the present invention, it is important that the complex viscosity of the spunbonded non-woven fabric layer measured under the conditions of 230 ° C. and 6.28 rad / sec is 100 Pa · sec or less. Within the above range, even if the yarn is stretched at a high spinning speed in order to increase the productivity, the viscosity is low, so that the deformation can be easily followed and stable spinning becomes possible. Further, by drawing at a high spinning speed, the orientation and crystallization of the fiber can be promoted to obtain a fiber having high mechanical strength. The complex viscosity of the spunbonded non-woven fabric layer is determined by mixing the types of polyolefin resins such as polyethylene resin and polypropylene resin, and when using a mixture of multiple types of resins with different complex viscosities, when mixing multiple types of resins. It can be adjusted by the mass ratio of.

The complex viscosity (Pa · sec) of the spunbonded non-woven fabric layer of the present invention is determined by using a dynamic viscoelasticity measuring device in accordance with “3.3 Complex Shear Viscosity” of JIS K 7244-10 (2005). The value measured according to the conditions of is adopted.
(1) Measuring jig: φ20 mm parallel plate (2) Gap of the above parallel plate: 0.5 mm
(3) Measurement temperature: 230 ° C
(4) Strain: 34.9%
(5) Frequency: 0.3 to 63 rad / sec

In the composite fiber composed of the thermoplastic resin (A1) and the polyethylene-based resin (A2) constituting the spunbonded nonwoven fabric layer of the present invention, the mass ratio of the polyethylene-based resin (A2) is 100 for the entire resin constituting the composite fiber. The mass% is preferably 20 to 50% by mass, and the mass ratio of the thermoplastic resin (A1) is preferably 50 to 80% by mass. By setting the mass ratio of polyethylene to preferably 20 to 50% by mass, more preferably 25 to 40% by mass, a composite fiber having sufficient adhesive strength and being flexible can be obtained. Further, by setting the mass ratio of the thermoplastic resin (A1) to preferably 50 to 80% by mass, more preferably 60 to 75% by mass, it is possible to obtain a composite fiber having strength that can be put into practical use.

The thermoplastic resin (A1), polyethylene-based resin (A2), and polyolefin-based resin (B) used in the present invention are usually used as antioxidants, weather stabilizers, and light-resistant materials as long as the effects of the present invention are not impaired. Additives such as stabilizers, antistatics, anti-fog agents, anti-blocking agents, lubricants, nucleating agents, and pigments, or other polymers can be added as needed.

The melting point of the thermoplastic resin (A1) or polyethylene-based resin (A2) used in the present invention is preferably 80 to 200 ° C, more preferably 100 to 180 ° C, and even more preferably 120 to 180 ° C. is there. By setting the melting point to preferably 80 ° C. or higher, more preferably 100 ° C. or higher, and further preferably 120 ° C. or higher, heat resistance that can withstand practical use can be easily obtained. Further, by setting the melting point to preferably 200 ° C. or lower, more preferably 180 ° C. or lower, it becomes easier to cool the yarn discharged from the mouthpiece, fusion of fibers is suppressed, and stable spinning becomes easier.

The melting point of the polyolefin resin (B) used in the present invention is preferably 80 to 200 ° C, more preferably 100 to 180 ° C, and even more preferably 120 to 180 ° C. By setting the melting point to preferably 80 ° C. or higher, more preferably 100 ° C. or higher, and further preferably 120 ° C. or higher, heat resistance that can withstand practical use can be easily obtained. Further, by setting the melting point to preferably 180 ° C. or lower, more preferably 150 ° C. or lower, it becomes easier to cool the yarn discharged from the mouthpiece, fusion of fibers is suppressed, and stable spinning becomes easier.

In order to improve slipperiness and flexibility, the laminated nonwoven fabric of the present invention contains a fatty acid amide compound having 23 or more and 50 or less carbon atoms in the polyethylene-based resin (A2) constituting the spunbonded nonwoven fabric. Is a preferred embodiment.

By setting the number of carbon atoms of the fatty acid amide compound to preferably 23 or more, and more preferably 30 or more, the fatty acid amide compound is suppressed from being excessively exposed on the fiber surface, and the spinnability and processing stability are excellent. , High productivity can be maintained. On the other hand, when the number of carbon atoms of the fatty acid amide compound is preferably 50 or less, more preferably 42 or less, the fatty acid amide compound can easily move to the fiber surface, and the laminated nonwoven fabric can be imparted with slipperiness and flexibility. it can.

Examples of the fatty acid amide compound having 23 or more and 50 or less carbon atoms used in the present invention include saturated fatty acid monoamide compounds, saturated fatty acid diamide compounds, unsaturated fatty acid monoamide compounds and unsaturated fatty acid diamide compounds.

Specifically, examples of the fatty acid amide compound having 23 or more and 50 or less carbon atoms include tetradokosanoic acid amide, hexadokosanoic acid amide, octadokosanoic acid amide, nervonic acid amide, tetracosaentapenic acid amide, heric acid amide, and ethylenebislauric acid. Amide, methylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbechenic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisstearic acid amide, hexamethylene hydroxystearic acid amide, distearyl Examples thereof include adipic acid amide, distearyl sebacic acid amide, ethylene bisoleic acid amide, ethylene biserucate amide, hexamethylene bisoleic acid amide, and the like, and these can be used in combination of two or more.

Among these fatty acid amide compounds, ethylene bisstearic acid amide, which is a saturated fatty acid diamide compound, is particularly preferably used in the present invention. Since the ethylene bisstearic acid amide is excellent in thermal stability, it can be melt-spun, and the polyethylene-based resin (A2) containing the ethylene bisstearic acid amide can maintain high productivity. Further, since the slipperiness between the fibers is improved, the fibers can be uniformly dispersed at the time of collection, which also contributes to the improvement of the smoothness of the non-woven fabric. Therefore, when the non-woven fabric is used, the opening diameter of the non-woven fabric can be reduced, and a laminated non-woven fabric having excellent water resistance and flexibility can be obtained.

In the present invention, the amount of the fatty acid amide compound added to the entire resin (a combination of the thermoplastic resin (A1) and the polyethylene-based resin (A2)) constituting the spunbonded nonwoven fabric layer constituting the laminated nonwoven fabric is 0.01 to It is preferably 5.0% by mass. The amount of the fatty acid amide compound added is preferably 0.01 to 5.0% by mass, more preferably 0.1 to 3.0% by mass, and further preferably 0.1 to 1.0% by mass. , It is possible to impart appropriate slipperiness and flexibility while maintaining spinnability.

[fiber]
It is important that the average single fiber diameter of the composite fiber composed of the thermoplastic resin (A1) and the polyethylene-based resin (A2) constituting the spunbonded nonwoven fabric layer according to the present invention is 6.5 to 11.9 μm. .. By setting the average single fiber diameter to 6.5 μm or more, preferably 7.5 μm or more, and more preferably 8.4 μm or more, deterioration of spinnability is prevented and a stable and high-quality non-woven fabric layer is formed. Can be done. On the other hand, by setting the average single fiber diameter to 11.9 μm or less, preferably 11.2 μm or less, and more preferably 10.6 μm or less, the flexibility and uniformity were high, and the content ratio of the melt blow nonwoven fabric layer was lowered. Even in this case, a laminated nonwoven fabric having excellent water resistance that can withstand practical use can be obtained.

In the present invention, the average single fiber diameter (μm) of the composite fibers constituting the spunbonded nonwoven fabric layer shall be a value calculated by the following procedure.
(1) A composite fiber composed of a thermoplastic resin (A1) and a polyethylene-based resin (A2) is melt-spun, towed and stretched by an ejector, and then a non-woven fabric layer is collected on a net.
(2) Randomly collect 10 small piece samples (100 x 100 mm).
(3) A surface photograph of 500 to 1000 times is taken with a microscope, and the width of a total of 100 composite fibers is measured, 10 from each sample.
(4) The average single fiber diameter (μm) is calculated from the average value of the measured 100 fibers.

1 to 3 are schematic cross-sectional views illustrating a cross section of a composite fiber constituting the spunbonded nonwoven fabric of the present invention.

1 and 2 are schematic cross-sectional views showing a cross section of a core-sheath type composite fiber. In FIG. 1, the centers of the core portion (a) and the sheath portion (b) are the same, and in FIG. 2, the centers of the core portion (a) and the sheath portion (b) are different.

Specifically, the core-sheath type composite fiber is composed of a core portion (a) and a sheath portion (b), and the core portion (a) is at least a part of a polymer different from the core portion (a) in the cross section of the fiber. A portion that is arranged so as to be surrounded by fibers and extends in the length direction of the fiber. The sheath portion (b) is a portion that is arranged so as to surround at least a part of the core portion (a) in the cross section of the fiber and extends in the length direction of the fiber. The eccentric core-sheath type composite fiber includes an exposed type in which the side surface of the core portion (a) is exposed and a non-exposed type in which the side surface of the core portion (a) is not exposed. In the present invention, a non-exposed eccentric core sheath type composite fiber is preferably used because of the stability of spinning.

FIG. 3 is a schematic cross-sectional view showing a cross section of the side-by-side type composite fiber. The side-by-side type composite fiber has a structure in which the first component (c) and the second component (d) are bonded together. The joint surface of these two components may be either a straight line or a curved line, and differs depending on the viscosity characteristics of the two components and the discharge rate ratio. The cross section of the composite fiber may be circular, or may be a modified cross section such as an ellipse.

On the other hand, the fibers made of the polyolefin resin (B) constituting the melt-blown nonwoven fabric according to the present invention preferably have an average single fiber diameter of 0.1 to 8.0 μm, preferably in the range of 0.4 to 7.0 μm. Is more preferable.

In the present invention, the average single fiber diameter (μm) of the fiber made of the polyolefin resin (B) constituting the melt-blown non-woven fabric layer shall be a value calculated by the following procedure.
(1) The polyolefin resin (B) is melt-spun and thinned with hot air, and then the non-woven fabric layer is collected on the net.
(2) Randomly collect 10 small piece samples (100 x 100 mm).
(3) A surface photograph of 500 to 2000 times is taken with a microscope, and the width of a total of 100 fibers is measured, 10 from each sample.
(4) The average single fiber diameter (μm) is calculated from the average value of the measured 100 fibers.

[Non-woven fabric layer]
The water resistance of the laminated nonwoven fabric of the present invention can be controlled by the characteristics of the spunbonded nonwoven fabric layer and the melt-blown nonwoven fabric layer constituting the laminated nonwoven fabric. The water resistance of the spunbonded non-woven fabric layer can be controlled by the average fiber diameter of the constituent fibers and the dispersibility of the surface fibers of the non-woven fabric layer. The water resistance of the melt-blown nonwoven fabric layer can be controlled by the average fiber diameter of the constituent fibers, the mass ratio of the laminated nonwoven fabric, and the degree of fusion between the fibers constituting the melt-blown nonwoven fabric layer.

[Laminated non-woven fabric]
It is important that the laminated non-woven fabric of the present invention is formed by laminating a spunbonded non-woven fabric layer and a melt-blown non-woven fabric layer. With this structure, it is possible to impart water resistance to a level higher than that required for a non-woven fabric for house wrap material.

The laminated non-woven fabric of the present invention preferably has a water pressure resistance per unit basis weight of 15 mmH ₂ O / (g / m ² ) or more. By setting the water pressure resistance per unit basis weight to preferably 15 mmH ₂ O / (g / m ² ) or more, more preferably 17 mmH ₂ O / (g / m ² ) or more, while maintaining water resistance that can withstand practical use. It is possible to obtain a laminated non-woven fabric having excellent flexibility, and further, it is possible to reduce the basis weight of the laminated non-woven fabric. There is no particular limitation on the upper limit of water pressure resistance, but the upper limit that can be achieved while maintaining the non-woven fabric structure is at most 30 mmH ₂ O / (g / m ² ).

The water pressure resistance per unit basis weight of the laminated non-woven fabric of the present invention is a value measured by the following procedure in accordance with JIS L1092 (2009) "7.1.1 A method (low water pressure method)". It shall be.
(1) Five test pieces having a width of 150 mm × 150 mm are collected from the laminated non-woven fabric at equal intervals in the width direction of the laminated non-woven fabric.
(2) Set the test piece on the clamp of the measuring device (the part of the test piece that comes into contact with water has a size of 100 cm ² ).
(3) A leveling device filled with water is used to raise the water level at a speed of 600 mm / min ± 30 mm / min, and the water level when water comes out from three places on the back side of the test piece is measured in mm units.
(4) The above measurement is performed with five test pieces, and the average value is taken as the water pressure resistance.

Further, in the present invention, regarding the surface smoothness and softness of the laminated non-woven fabric, the surface roughness SMD by the KES method (Kawabata Evolution System), the average friction coefficient MIU by the KES method, and the average friction by the KES method Coefficient variation Evaluated by MMD.

The laminated nonwoven fabric of the present invention preferably has a surface roughness SMD of 1.0 to 2.6 μm by the KES method on at least one side. By setting the surface roughness SMD by the KES method to preferably 1.0 μm or more, more preferably 1.3 μm or more, further preferably 1.6 μm or more, still more preferably 2.0 μm or more, the fibers become excessive. It is possible to prevent the texture from being deteriorated and the flexibility from being impaired due to the densification.

On the other hand, the surface roughness SMD by the KES method is preferably 2.6 μm or less, more preferably 2.5 μm or less, further preferably 2.4 μm or less, still more preferably 2.3 μm or less, so that the surface can be surfaced. It is possible to obtain a laminated non-woven fabric that is smooth, has little roughness, and is excellent in touch. The surface roughness SMD by the KES method can be controlled by appropriately adjusting the average single fiber diameter, the MFR of the laminated non-woven fabric, and the like.

In the present invention, the surface roughness SMD by the KES method shall adopt the value measured as follows.
(1) Three test pieces having a width of 200 mm × 200 mm are collected from the laminated non-woven fabric at equal intervals in the width direction of the laminated non-woven fabric.
(2) Set the test piece on the sample table.
(3) Scan the surface of the test piece with a contact for surface roughness measurement (material: φ0.5 mm piano wire, contact length: 5 mm) to which a load of 10 gf is applied, and measure the average deviation of the uneven shape of the surface. To do.
(4) The above measurement was performed in the vertical direction (longitudinal direction of the non-woven fabric) and the horizontal direction (width direction of the non-woven fabric) of all the test pieces, and the average deviations of these 6 points in total were averaged to the second place after the decimal point. Is rounded to the surface roughness SMD (μm).

The average friction coefficient MIU of the laminated non-woven fabric of the present invention by the KES method on at least one side is preferably 0.1 to 0.5. By setting the average friction coefficient MIU to preferably 0.5 or less, more preferably 0.45 or less, and further preferably 0.4 or less, the slipperiness of the surface of the non-woven fabric is improved and the texture is better. Can be.

On the other hand, when the average coefficient of friction MIU is preferably 0.1 or more, more preferably 0.15 or more, and further preferably 0.2 or more, the lubricant is excessively added and the spinnability is deteriorated. When collecting the threads on the net, it is possible to prevent the threads from slipping and worsening the formation. The average coefficient of friction MIU by the KES method is controlled by appropriately adjusting the average single fiber diameter, MFR of the laminated non-woven fabric, etc., or by adding a lubricant to the polyethylene resin (A2) or polyolefin resin (B). Can be done.

The variation MMD of the average friction coefficient by the KES method on at least one side of the laminated nonwoven fabric of the present invention is preferably 0.008 or less. By setting the fluctuation MMD of the average friction coefficient to preferably 0.008 or less, more preferably 0.0075 or less, and further preferably 0.0070 or less, the roughness of the surface of the laminated nonwoven fabric can be further reduced. ..

Fluctuation of average coefficient of friction by KES method MMD is controlled by appropriately adjusting the average single fiber diameter and MFR of laminated non-woven fabric, or by adding a lubricant to polyethylene resin (A2) or polyolefin resin (B). can do.

In the present invention, the average friction coefficient MIU and the fluctuation MMD of the average friction coefficient by the KES method shall adopt the values measured as follows.
(1) Three test pieces having a width of 200 mm × 200 mm are collected from the laminated non-woven fabric at equal intervals in the width direction of the laminated non-woven fabric.
(2) Set the test piece on the sample table.
(3) The surface of the test piece is scanned with a contact friction element (material: φ0.5 mm piano wire (20 pieces in parallel), contact area: 1 cm ² ) to which a load of 50 gf is applied, and the average friction coefficient is measured.
(4) The above measurement was performed in the vertical direction (longitudinal direction of the non-woven fabric) and the horizontal direction (width direction of the non-woven fabric) of all the test pieces, and the average deviations of these 6 points in total were averaged to the 4th place after the decimal point. Is rounded to the average coefficient of friction MIU. Further, the fluctuations of the average friction coefficient of the above 6 points were further averaged and rounded to the fourth decimal place to obtain the fluctuation MMD of the average friction coefficient.

Further, in the present invention, the flexibility of the laminated non-woven fabric is evaluated by the air volume and the sensory test.

The air flow rate per unit basis weight of the laminated non-woven fabric of the present invention is preferably 0.5 to 10 (cc / (cm ² · sec)) / (g / m ² ). The air volume per unit grain is preferably 8 (cc / (cm ² · sec)) / (g / m ² ) or less, and more preferably 6 (cc / (cm ² · sec)) / (g / m ^2). ) Or less, more preferably 4 (cc / (cm ² · sec)) / (g / m ² ) or less, so that the air permeability required for house wrap applications and the like can be sufficiently satisfied.

On the other hand, the air flow rate per unit is preferably 0.2 (cc / (cm ² · sec)) / (g / m ² ) or more, and more preferably 0.4 (cc / (cm ² · sec)). By setting it to / (g / m ² ) or more, more preferably 0.6 (cc / (cm ² · sec)) / (g / m ² ) or more, the spunbonded non-woven fabric becomes excessively dense and flexible. It is possible to prevent the sex from being impaired. The air volume can be adjusted by the basis weight, single fiber fineness, the basis weight of the melt blow layer and the thermocompression bonding conditions (compression rate, temperature and linear pressure).

In the present invention, the air volume per unit basis weight of the laminated non-woven fabric shall be a value measured by the following procedure in accordance with "6.8.1 Frazier method" of JIS L1913 (2010). To do.
(1) A test piece of 80 cm × 100 cm is cut out from the laminated non-woven fabric.
(2) At a barometer pressure of 125 Pa, measure at any 20 points on the test piece.
(3) The average value of the above 20 points is calculated by rounding off the second decimal place.
(4) Multiply the calculated air volume (cc / (cm ² · sec)) by the basis weight (g / m ² ).

In the laminated nonwoven fabric of the present invention, the content of the melt-blown nonwoven fabric layer is preferably 1% by mass or more and 15% by mass or less, and more preferably 2% by mass or more and 10% by mass or less with respect to the mass of the laminated nonwoven fabric. By setting the content of the melt-blown non-woven fabric layer to preferably 1% by mass or more, more preferably 2% by mass or more, water resistance that can withstand practical use can be imparted. Further, by setting the content of the melt-blown non-woven fabric layer to preferably 5% by mass or less, and more preferably 10% by mass or less, the hardness peculiar to the melt-blown non-woven fabric can be reduced.

Further, by setting the content of the spunbonded nonwoven fabric layer in the laminated nonwoven fabric to preferably more than 85% by mass and less than 99% by mass, the laminated nonwoven fabric having excellent flexibility and workability can be obtained.

In the present invention, the content ratio of the melt-blown nonwoven fabric layer shall be a value measured by the following procedure.
(1) Three test pieces having a width of 100 mm × 100 mm are collected at equal intervals in the width direction of the laminated non-woven fabric.
(2) Collect only the non-bonded portion of the laminated non-woven fabric.
(3) The masses of the collected test piece and the melt-blown non-woven fabric collected from the test piece are measured.
(4) Calculate the content ratio of the melt-blown non-woven fabric in the laminated non-woven fabric.

The basis weight of the laminated nonwoven fabric of the present invention is preferably 10 to 100 g / m ² . By setting the basis weight to preferably 10 g / m ² or more, more preferably 13 g / m ² or more, and further preferably 15 g / m ² or more, a laminated non-woven fabric having mechanical strength that can be put into practical use can be obtained.

On the other hand, when the basis weight is preferably 100 g / m ² or less, more preferably 50 g / m ² or less, and further preferably 30 g / m ² or less, when used as a house wrap material, the operator holds it in his / her hand during construction. The weight is suitable for the work, and the laminated non-woven fabric having excellent handleability at the time of construction can be obtained. In addition, a laminated non-woven fabric having excellent handleability can be obtained even when it is used for other purposes.

In the present invention, the basis weight of the laminated non-woven fabric shall be a value measured by the following procedure in accordance with "6.2 Mass per unit area" of JIS L1913 (2010).
(1) Collect three 20 cm × 25 cm test pieces per 1 m of sample width.
(2) Weigh each mass (g) in the standard state.
(3) The average value is expressed by the mass per 1 m ² (g / m ² ).

The thickness of the laminated nonwoven fabric of the present invention is preferably 0.05 to 1.5 mm. By setting the thickness to preferably 0.05 to 1.5 mm, more preferably 0.08 to 1.0 mm, still more preferably 0.10 to 0.8 mm, flexibility and appropriate cushioning properties are provided, and the house wrap is provided. When used as a material, the weight is suitable for the operator to hold and work during construction, the rigidity of the non-woven fabric is not too strong, and a laminated non-woven fabric having excellent handleability during construction can be obtained.

In the present invention, the thickness (mm) of the laminated non-woven fabric shall be a value measured by the following procedure in accordance with "5.1" of JIS L1906 (2000).
(1) Using a pressurizer having a diameter of 10 mm, the thickness of 10 points per 1 m is measured in units of 0.01 mm at equal intervals in the width direction of the nonwoven fabric under a load of 10 kPa.
(2) Round off the third decimal place of the average value of the above 10 points.

The apparent density of the laminated nonwoven fabric of the present invention is preferably 0.05 to 0.3 g / cm ³ . By setting the apparent density to preferably 0.3 g / cm ³ or less, more preferably 0.25 g / cm ³ or less, and further preferably 0.20 g / cm ³ or less, the fibers are densely packed and laminated. It is possible to prevent the flexibility of the non-woven fabric from being impaired.

On the other hand, preferably the apparent density is set to 0.05 g / cm ³ or more, more preferably set to 0.08 g / cm ³ or more, more preferably by a 0.10 g / cm ³ or more, fluffing and delamination occurs It is possible to obtain a laminated non-woven fabric having strength, flexibility and handleability that can withstand practical use.

In the present invention, the apparent density (g / cm ³ ) is calculated based on the following formula from the basis weight and thickness before rounding, and is rounded to the third decimal place.
-Appearance density (g / cm ³ ) = [Metsuke (g / m ² )] / [Thickness (mm)] x 10 ^-3 .

The stress at 5% elongation per unit basis weight of the laminated nonwoven fabric of the present invention (hereinafter, may be referred to as 5% modulus per unit basis weight) is 0.06 to 0.33 (N / 25 mm) / (g). / M ² ), more preferably 0.13 to 0.30 (N / 25 mm) / (g / m ² ), and even more preferably 0.20 to 0.27 (N / 25 mm). / (G / m ² ). Within the above range, a spunbonded non-woven fabric that is flexible and has excellent tactile sensation can be obtained while maintaining the strength that can be put into practical use.

In the present invention, the stress at 5% elongation per unit basis weight of the laminated nonwoven fabric is measured by the following procedure according to "6.3 Tensile Strength and Elongation Rate (ISO Method)" of JIS L1913 (2010). The value to be used shall be adopted.
(1) Three 25 mm × 300 mm test pieces are collected per 1 m in width in each of the vertical direction (longitudinal direction of the non-woven fabric) and the horizontal direction (width direction of the non-woven fabric) of the non-woven fabric.
(2) Grasp the test piece and set it in the tensile tester at an interval of 200 mm.
(3) A tensile test is carried out at a tensile speed of 100 mm / min, and the stress at 5% elongation (5% modulus) is measured.
(4) Obtain the average value of the 5% modulus in the vertical and horizontal directions measured with each test piece, calculate the 5% modulus per unit basis weight based on the following formula, and round off to the third decimal place.
5% modulus per unit basis weight ((N / 25 mm) / (g / m ² )) = [average value of 5% modulus (N / 25 mm)] / basis weight (g / m ² ).

[Manufacturing method of laminated non-woven fabric]
Next, a preferred embodiment of the method for producing the laminated nonwoven fabric of the present invention will be specifically described.

The laminated non-woven fabric of the present invention is a laminated non-woven fabric composed of a non-woven fabric produced by the spunbond (S) method and the melt blow (M) method. The method for producing a laminated non-woven fabric of the present invention can be carried out according to any method as long as the spunbonded non-woven fabric layer and the melt-blown non-woven fabric layer can be laminated. For example, a method in which fibers formed by the melt-blow method are directly deposited on a non-woven fabric layer obtained by the spunbond method to form a melt-blow non-woven fabric layer, and then the spunbond non-woven fabric layer and the melt-blow non-woven fabric layer are fused, span. A method of superimposing a bonded non-woven fabric layer and a melt-blown non-woven fabric layer and fusing the two non-woven fabric layers by heating and pressurizing. A method of bonding or the like can be adopted. From the viewpoint of productivity, a method of directly forming the melt-blown non-woven fabric layer on the spunbonded non-woven fabric layer is a preferable embodiment.

Further, depending on the purpose, the spunbonded nonwoven fabric layer (S) and the melt-blown nonwoven fabric layer (M) can have a structure in which SM, SMS, SMMS, SMSMS, and SMS are laminated.

In the spunbonded non-woven fabric layer, first, a molten thermoplastic resin (polyolefin resin) is spun from a spinneret as long fibers, which is suction-stretched with compressed air by an ejector, and then the fibers are collected on a moving net. The non-woven fabric is layered.

As the shape of the spinneret and the ejector, various shapes such as a round shape and a rectangular shape can be adopted. Among them, the combination of the rectangular base and the rectangular ejector is suitable because the amount of compressed air used is relatively small and the energy cost is excellent, the threads are less likely to be fused or scratched, and the threads can be easily opened. It is preferably used.

In the present invention, for example, the thermoplastic resin (A1) and the polyethylene-based resin (A2) are melted and weighed in different extruders to form a fiber cross section preferably as shown in FIG. 1 on a composite spinneret. It is supplied to a core-sheath fiber spinneret, and a polypropylene-based resin is placed in the core component, and a polyethylene-based resin is placed in the sheath component to be spun as long fibers having a core-sheath cross section.

The spinning temperature at the time of melting and spinning the thermoplastic resin (A1) and the polyethylene-based resin (A2) is preferably 200 to 270 ° C, more preferably 210 to 260 ° C, still more preferably 220 to 250. ℃. By setting the spinning temperature within the above range, a stable molten state can be obtained and excellent spinning stability can be obtained.

The spun long fiber yarns are then cooled. Examples of the method of cooling the spun yarn include a method of forcibly blowing cold air on the yarn, a method of naturally cooling at the ambient temperature around the yarn, and a method of adjusting the distance between the spinneret and the ejector. Etc., or a method of combining these methods can be adopted. Further, the cooling conditions can be appropriately adjusted and adopted in consideration of the discharge amount per single hole of the spinneret, the spinning temperature, the atmospheric temperature and the like.

Next, the cooled and solidified yarn is towed and stretched by the compressed air injected from the ejector. The spinning speed is preferably 3,000 to 6,500 m / min, more preferably 3,500 to 6,500 m / min, and even more preferably 4,000 to 6,500 m / min. By setting the spinning speed to 3,000 to 6,500 m / min, high productivity can be obtained, orientation and crystallization of fibers can be advanced, and high-strength long fibers can be obtained. Normally, as the spinning speed is increased, the spinnability deteriorates and it is not possible to stably produce a filamentous shape. However, as described above, the thermoplastic resin (A1) and the polyethylene-based resin (A2) having a specific range of MFR ) Can be used to stably spin the intended composite fiber.

Subsequently, the obtained long fibers are collected on a moving net to form a non-woven fabric layer. In the present invention, it is also a preferred embodiment that the heat flat roll is brought into contact with the non-woven fabric layer from one side on the net to temporarily bond the non-woven fabric layer. By doing so, it is possible to prevent the surface layer of the non-woven fabric layer from being turned over or blown off during transportation on the net, resulting in deterioration of the texture, and to improve the transportability from collecting the threads to thermocompression bonding. Can be improved.

Next, a conventionally known method can be adopted for the melt blow nonwoven fabric. First, the polyolefin resin (B) is melted in an extruder and supplied to the base portion, and hot air is blown onto the threads extruded from the base to make the yarn finer, and then a non-woven fabric layer is formed on the collection net. In the melt blow method, fine fibers of several μm can be easily obtained without requiring a complicated process, and high water resistance characteristics can be easily achieved.

Subsequently, the obtained laminated non-woven fabric layer and the melt-blown non-woven fabric layer are laminated, and these are heat-bonded to obtain the intended laminated non-woven fabric.

The method of heat-bonding the non-woven fabric layer is not particularly limited. For example, a heat-embossed roll in which the upper and lower roll surfaces are engraved (concavo-convex portions), a roll having a flat (smooth) one roll surface and the other roll. Thermal bonding methods using various rolls, such as thermal embossing rolls consisting of rolls with engraved surfaces and thermal calendar rolls consisting of a pair of upper and lower flat (smooth) rolls, and horns Examples thereof include a method such as ultrasonic bonding in which heat welding is performed by ultrasonic vibration.

Among them, it is highly productive, it can give strength with a partial heat-bonded part, and can maintain the texture and feel unique to non-woven fabric with a non-bonded part, so it is engraved on each of the upper and lower roll surfaces (uneven parts). ) Is applied, or a heat embossed roll consisting of a roll having a flat (smooth) surface on one roll and a roll having an engraving (unevenness) on the surface of the other roll is preferably used. It is an aspect.

As the surface material of the heat embossed roll, a metal roll and a metal roll are used in order to obtain a sufficient thermocompression bonding effect and prevent the engraving (uneven part) of one embossed roll from being transferred to the surface of the other roll. A pair is a preferred embodiment.

The embossing adhesion area ratio by such a heat embossing roll is preferably 5 to 30%. By setting the adhesive area to preferably 5% or more, more preferably 8% or more, and further preferably 10% or more, strength that can be put into practical use as a laminated non-woven fabric can be obtained. On the other hand, by setting the bonding area to preferably 30% or less, more preferably 25% or less, and further preferably 20% or less, it is possible to obtain appropriate flexibility particularly suitable for use in building material applications. .. Even when ultrasonic bonding is used, the bonding area ratio is preferably in the same range.

The adhesive area referred to here refers to the ratio of the adhesive portion to the entire laminated non-woven fabric. Specifically, when heat-bonding is performed by a roll having a pair of irregularities, the convex portion of the upper roll and the convex portion of the lower roll overlap and occupy the entire laminated non-woven fabric portion (adhesive portion) that abuts on the non-woven fabric layer. Say the percentage. Further, when the roll having unevenness and the flat roll are thermally bonded, the ratio of the convex portion of the roll having unevenness to the entire laminated nonwoven fabric of the portion (adhesive portion) in contact with the nonwoven fabric layer. Further, in the case of ultrasonic bonding, it refers to the ratio of the portion (bonded portion) to be heat-welded by ultrasonic processing to the entire laminated non-woven fabric.

The shape of the bonded portion by thermal embossing roll or ultrasonic bonding is not particularly limited, and for example, a circle, an ellipse, a square, a rectangle, a parallelogram, a rhombus, a regular hexagon, a regular octagon, or the like can be used. Further, it is preferable that the adhesive portions are uniformly present at regular intervals in the longitudinal direction (transportation direction) and the width direction of the laminated nonwoven fabric. By doing so, it is possible to reduce variations in the strength of the laminated non-woven fabric.

The surface temperature of the heat embossed roll at the time of heat bonding is preferably −50 to −15 ° C. with respect to the melting point of the polyethylene resin (A2) used. By setting the surface temperature of the thermal roll to -50 ° C or higher, more preferably -45 ° C or higher with respect to the melting point of the polyethylene resin (A2), a laminated non-woven fabric having a strength that can be appropriately heat-bonded and put into practical use can be obtained. Obtainable. Further, by setting the surface temperature of the heat embossed roll to -15 ° C. or lower, more preferably -20 ° C. or lower with respect to the melting point of the polyethylene resin (A2), excessive thermal adhesion is suppressed and the laminated non-woven fabric is used. In particular, it is possible to obtain appropriate flexibility and workability suitable for use in building material applications.

The linear pressure of the heat embossing roll at the time of heat bonding is preferably 50 to 500 N / cm. By setting the linear pressure of the roll to preferably 50 N / cm or more, more preferably 100 N / cm or more, and further preferably 150 N / cm or more, a laminated non-woven fabric having a strength that can be appropriately heat-bonded and put into practical use can be obtained. Can be done.

On the other hand, the linear pressure of the heat embossed roll is preferably 500 N / cm or less, more preferably 400 N / cm or less, and further preferably 300 N / cm or less, so that it can be used as a laminated non-woven fabric, especially for building material applications. Appropriate flexibility and workability can be obtained.

Further, in the present invention, for the purpose of adjusting the thickness of the laminated non-woven fabric, thermocompression bonding may be performed by a thermal calendar roll composed of a pair of upper and lower flat rolls before and / or after thermal bonding by the above thermal embossing roll. it can. A pair of upper and lower flat rolls is a metal roll or an elastic roll having no unevenness on the surface of the roll, and a metal roll and a metal roll are paired, or a metal roll and an elastic roll are paired. Can be used.

Further, the elastic roll here is a roll made of a material having elasticity as compared with a metal roll. Examples of the elastic roll include so-called paper rolls such as paper, cotton and aramid paper, and resin rolls made of urethane-based resin, epoxy-based resin, silicon-based resin, polyester-based resin and hard rubber, and a mixture thereof. Can be mentioned.

Next, the laminated nonwoven fabric of the present invention will be specifically described based on Examples. In the measurement of each physical property, those unless otherwise specified are those measured based on the above method.

(1) Resin MFR (g / 10 minutes):
Regarding the MFR of the thermoplastic resin (A1) and the polyolefin resin (B), the polypropylene resins (A1a) and (B) were measured under the conditions of a load of 2.16 kg and a temperature of 230 ° C. The MFR of the polyethylene resin (A2) was measured under the conditions of a load of 2.16 kg and a temperature of 190 ° C.

(2) MFR of laminated fiber (g / 10 minutes):
The MFR of the laminated non-woven fabric was measured under the conditions of a load of 2.16 kg and a temperature of 230 ° C.

(3) Complex viscosity (Pa · sec):
Using the dynamic viscoelasticity measuring device "RHEOSOL-G3000", the complex viscosity (Pa) of the laminated non-woven fabric at 20 mm parallel plate, gap 0.5 mm, temperature 230 ° C., strain 34.9%, frequency 0.3 to 63 rad / sec. -Sec) was measured.

(4) Spinning speed (m / min):
From the above average single fiber diameter and the solid density of the polyolefin resin (A) or polyolefin resin (B) used, the mass per 10,000 m in length is defined as the average single fiber fineness (dtex), and the second decimal point is used. Calculated by rounding off the decimal point. Based on the average single fiber fineness and the discharge amount of resin discharged from the single hole of the spinneret (hereinafter abbreviated as single hole discharge amount) (g / min) set under each condition, the spinning speed is based on the following formula. Was calculated.
-Spinning speed (m / min) = (10000 x [single hole discharge amount (g / min)]) / [average single fiber fineness (dtex)].

(5) Water pressure resistance of laminated non-woven fabric (mmH ₂ O):
A water pressure resistance tester "Hydrotester" (FX-3000-IV type) manufactured by Swiss Textest Co., Ltd. was used.

(6) Aeration rate per unit basis weight of the laminated non-woven fabric ((cc / cm ² · sec) / (g / m ² )):
The air volume was measured based on the above method. The calculated air volume (cc / (cm ² · sec)) is calculated by rounding off the second decimal place from the basis weight (g / m ² ) obtained based on the above method. The amount of airflow per hit was calculated.
・ Air volume per unit basis weight = air volume (cc / (cm ² · sec)) / basis weight (g / m ² ).

(7) Surface roughness SMD (μm) of laminated non-woven fabric by KES method:
For the measurement, an automated surface tester "KES-FB4-AUTO-A" manufactured by Kato Tech Co., Ltd. was used. The surface roughness SMD was measured on both sides of the laminated non-woven fabric, and Table 1 shows the smaller value among them.

(8) Fluctuations in average friction coefficient MIU of laminated non-woven fabric by KES method and average friction coefficient of laminated non-woven fabric by KES method MMD:
For the measurement, an automated surface tester "KES-FB4-AUTO-A" manufactured by Kato Tech Co., Ltd. was used. The average coefficient of friction MIU was measured on both sides of the laminated non-woven fabric, and Table 1 shows the smaller value.

(9) Flexibility of non-woven fabric (processability):
As a sensory evaluation of the texture of the non-woven fabric, the flexibility was scored according to the following criteria. This was performed by 10 people, and the average was evaluated as the texture of the non-woven fabric. It was judged that the higher each score was, the more flexible it was and the better the workability in various processing, and 4.0 points or more were passed.
<Flexibility (workability)>
5 points: Flexible (good workability)
4 points: Intermediate between 5 points and 3 points 3 points: Normal 2 points: Intermediate between 3 points and 1 point 1 point: Hard (poor workability).

[Example 1]
(Spanbond non-woven fabric layer (lower layer))
The spunbonded non-woven fabric layer is a polypropylene resin made of a homopolymer having an MFR of 170 g / 10 min and a melting point of 163 ° C. as a thermoplastic resin (A1), and a homopolymer having an MFR of 100 g / 10 min as a polyethylene resin (A2). A polyethylene resin (LLDPE) made of a polymer was used. The thermoplastic resin (A1) and the polyethylene-based resin (A2) are each melted by an extruder, and from a rectangular mouthpiece having a hole diameter of 0.30 mm and a hole depth of 2 mm, the spinning temperature is 235 ° C. Was 0.43 g / min, and the thermoplastic resin (A1) was placed in the core component, and the polyethylene-based resin (A2) was spun out in a core-sheath type cross section in which the sheath component was placed. After the spun yarn was cooled and solidified, it was towed and stretched by compressed air having an ejector pressure of 0.50 MPa in a rectangular ejector, and collected on a moving net. As a result, a spunbonded non-woven fabric layer having a basis weight of 8.2 g / m ² was formed, which was composed of long fibers of core-sheath type composite fibers. The characteristics of the fibers constituting the formed spunbonded non-woven fabric layer were that the average single fiber diameter was 10.9 μm, and the spinning speed converted from this was 5,050 m / min. As for spinnability, no yarn breakage was observed after spinning for 1 hour, which was good.

(Melt blow non-woven fabric layer)
Next, as the polyolefin resin (B), a polypropylene resin made of a homopolymer having an MFR of 1100 g / min and a melting point of 163 ° C. was used for the melt-blown non-woven fabric layer. This polyolefin resin (B) was melted by an extruder and spun from a base having a pore diameter of 0.25 mm at a spinning temperature of 260 ° C. and a single-hole discharge rate of 0.10 g / min. Then, air was injected into the yarn under the conditions of an air temperature of 290 ° C. and an air pressure of 0.10 MPa, and collected on the spunbonded non-woven fabric layer to form a melt-blown non-woven fabric layer. At this time, the basis weight of the melt-blown non-woven fabric layer separately collected on the collection net under the same conditions was 1.6 g / m ² , and the average fiber diameter was 1.5 μm.

(Spanbond non-woven fabric layer (upper layer))
Further, the long fibers of the core-sheath type composite fiber were collected under the same conditions as the condition for forming the lower spunbonded non-woven fabric layer on the melt-blown non-woven fabric layer to form the spunbonded nonwoven fabric layer. As a result, a spunbond-melt blow-spunbond laminated fiber web having a total basis weight of 18 g / m ² was obtained.

(Laminated non-woven fabric)
Subsequently, the obtained laminated fiber web was used as an embossed roll having an adhesive area ratio of 16% with a metal polka dot pattern engraved on the upper roll, and a pair of upper and lower thermal embossed rolls composed of a metal flat roll on the lower roll. A laminated non-woven fabric having a grain size of 18 g / m ² was obtained by heat-bonding under the conditions of a linear pressure of 300 N / cm and a heat-bonding temperature of 120 ° C. With respect to the obtained laminated non-woven fabric, the thickness, apparent density, water pressure resistance, air flow rate per unit grain, complex viscosity, surface roughness SMD, average friction coefficient MIU, and fluctuation MMD of average friction coefficient were measured, and further, the laminated non-woven fabric was further measured. Was evaluated for flexibility. The results are shown in Table 1.

[Example 2]
(Spanbond non-woven fabric layer (lower layer) / (upper layer))
A span made of core-sheath composite fibers by the same method as in Example 1 except that a polypropylene resin made of a homopolymer having an MFR of 300 g / 10 minutes and a melting point of 163 ° C. was used as the thermoplastic resin (A1). A bonded non-woven fabric layer was formed. The characteristics of the long fibers constituting the formed spunbonded non-woven fabric layer were that the average single fiber diameter was 10.5 μm, and the spinning speed converted from this was 5,500 m / min. As for spinnability, no yarn breakage was observed after spinning for 1 hour, which was good.

(Melt blow non-woven fabric layer)
A melt-blown non-woven fabric layer was formed in the same manner as in Example 1. The characteristics of the fibers constituting the obtained melt-blown non-woven fabric layer were that the average fiber diameter was 1.5 μm.

(Laminated non-woven fabric)
A laminated non-woven fabric was obtained in the same manner as in Example 1. With respect to the obtained laminated non-woven fabric, the thickness, apparent density, water pressure resistance, air flow rate per unit grain, complex viscosity, surface roughness SMD, average friction coefficient MIU, and fluctuation MMD of average friction coefficient were measured, and further, the laminated non-woven fabric was further measured. Was evaluated for flexibility. The results are shown in Table 1.

[Example 3]
(Spanbond non-woven fabric layer (lower layer) / (upper layer))
A spunbond made of a core-sheath composite fiber by the same method as in Example 1 except that a polypropylene resin made of a homopolymer having an MFR of 800 g / 10 min and a melting point of 163 ° C. was used as the thermoplastic resin (A1). A non-woven fabric layer was formed. The characteristics of the long fibers constituting the formed spunbonded non-woven fabric layer were that the average single fiber diameter was 9.8 μm, and the spinning speed converted from this was 6,300 m / min. As for spinnability, no yarn breakage was observed after spinning for 1 hour, which was good.

(Melt blow non-woven fabric layer)
A melt-blown non-woven fabric layer was formed in the same manner as in Example 2.

(Laminated non-woven fabric)
A laminated non-woven fabric was obtained in the same manner as in Example 1. With respect to the obtained laminated non-woven fabric, the thickness, apparent density, water pressure resistance, air flow rate per unit grain, complex viscosity, surface roughness SMD, average friction coefficient MIU, and fluctuation MMD of average friction coefficient were measured, and further, the laminated non-woven fabric was further measured. Was evaluated for flexibility. The results are shown in Table 1.

[Example 4]
(Spanbond non-woven fabric layer (lower layer) / (upper layer))
A spunbonded non-woven fabric layer was obtained by the same method as in Example 1 except that the single-hole discharge rate was 0.21 g / min. The characteristics of the fibers constituting the formed spunbonded non-woven fabric layer were that the average single fiber diameter was 7.4 μm, and the spinning speed converted from this was 5,700 m / min.

(Melt blow non-woven fabric layer)
A melt-blown non-woven fabric layered fiber web was obtained in the same manner as in Example 1.

(Laminated non-woven fabric)
A laminated non-woven fabric was obtained in the same manner as in Example 1. With respect to the obtained laminated non-woven fabric, the thickness, apparent density, water pressure resistance, air flow rate per unit grain, complex viscosity, surface roughness SMD, average friction coefficient MIU, and fluctuation MMD of average friction coefficient were measured, and further, the laminated non-woven fabric was further measured. Was evaluated for flexibility. The results are shown in Table 1.

[Example 5]
(Spanbond non-woven fabric layer (lower layer) / (upper layer))
A spunbonded non-woven fabric layer was obtained by the same method as in Example 4 except that the basis weight was 8.5 g / m ² .

(Melt blow fiber web)
A melt-blown non-woven fabric layer was obtained by the same method as in Example 1 except that the air pressure was 0.20 MPa and the basis weight was 1.0 g / m ² . The characteristics of the fibers constituting the obtained melt-blown non-woven fabric layer were that the average fiber diameter was 1.0 μm.

(Laminated non-woven fabric)
A laminated non-woven fabric was obtained in the same manner as in Example 1. With respect to the obtained laminated non-woven fabric, the thickness, apparent density, water pressure resistance, air flow rate per unit grain, complex viscosity, surface roughness SMD, average friction coefficient MIU, and fluctuation MMD of average friction coefficient were measured, and further, the laminated non-woven fabric was further measured. Was evaluated for flexibility. The results are shown in Table 1.

[Example 6]
(Spanbond non-woven fabric layer (lower layer) / (upper layer))
Example 1 except that 1.0% by mass of ethylene bisstearic acid amide was added to the polyethylene-based resin (A2) so that the amount added to the entire resin constituting the spunbonded nonwoven fabric layer was 0.3% by mass. A spunbonded non-woven fabric layer was obtained in the same manner as above.

(Melt blow non-woven fabric layer)
A melt-blown non-woven fabric layer was obtained in the same manner as in Example 1.

(Laminated non-woven fabric)
A laminated non-woven fabric was obtained in the same manner as in Example 1. With respect to the obtained laminated non-woven fabric, the thickness, apparent density, water pressure resistance, air flow rate per unit grain, complex viscosity, surface roughness SMD, average friction coefficient MIU, and fluctuation MMD of average friction coefficient were measured, and further, the laminated non-woven fabric was further measured. Was evaluated for flexibility. The results are shown in Table 1.

[Comparative Example 1]
(Spanbond non-woven fabric layer (lower layer) / (upper layer))
As the thermoplastic resin (A1), a homopolypropylene resin having an MFR of 60 g / 10 min and a melting point of 163 ° C. was used, and the spunbonded nonwoven fabric layer was prepared by the same method as in Example 1 except that the ejector pressure was 0.15 MPa. Obtained. The characteristics of the long fibers constituting the obtained core-sheath type non-woven fabric layer were that the average single fiber diameter was 18.0 μm, and the spinning speed converted from this was 1,900 m / min. Regarding the spinnability, the yarn was broken 11 times in 1 hour of spinning, which was poor.

(Melt blow non-woven fabric layer)
A melt-blown non-woven fabric layer was obtained in the same manner as in Example 1.

(Laminated non-woven fabric)
A laminated non-woven fabric was obtained in the same manner as in Example 1. With respect to the obtained laminated nonwoven fabric, the thickness, apparent density, water pressure resistance, air flow rate per unit grain, surface roughness SMD, average friction coefficient MIU, and variation MMD of average friction coefficient were measured, and the flexibility of the laminated nonwoven fabric was further measured. Was evaluated. The results are shown in Table 1.

[Comparative Example 2]
(Spanbond non-woven fabric layer (lower layer) / (upper layer))
A spunbonded non-woven fabric layer was obtained by the same method as in Example 1 except that a homopolyethylene resin having an MFR of 20 g / 10 min was used as the polyethylene-based resin (A2) and the ejector pressure was 0.15 MPa. The characteristics of the long fibers constituting the obtained core-sheath type non-woven fabric layer were that the average single fiber diameter was 17.4 μm, and the spinning speed converted from this was 1,900 m / min. Regarding the spinnability, the yarn was broken 9 times in 1 hour of spinning, which was poor.

(Melt blow non-woven fabric layer)
A melt-blown non-woven fabric layer was obtained in the same manner as in Example 1.

(Laminated non-woven fabric)
A laminated non-woven fabric was obtained in the same manner as in Example 1. With respect to the obtained laminated non-woven fabric, the thickness, apparent density, water pressure resistance, air flow rate per unit grain, complex viscosity, surface roughness SMD, average friction coefficient MIU, and fluctuation MMD of average friction coefficient were measured, and further, the laminated non-woven fabric was further measured. Was evaluated for flexibility. The results are shown in Table 1.

In Examples 1 to 6, the surface roughness SMD by the KES method is 1.8 to 2.1 μm, and the water pressure resistance per unit basis weight is 15 mmH ₂ O / (g / m ² ) or more, which is excellent water resistance characteristics. Was. Further, the laminated non-woven fabric of Example 6 in which ethylene bisstearic acid amide is added to the fibers constituting the spunbonded non-woven fabric layer has a reduced average friction coefficient, increased flexibility and excellent workability, and is used for a house wrap material. It was particularly suitable as a non-woven fabric.
On the other hand, the laminated nonwoven fabrics of Comparative Examples 1 and 2 had a surface roughness SMD of 2.7 μm or more, were inferior in water resistance, and had low flexibility.

Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications and modifications can be made without departing from the intent and scope of the invention. This application is based on a Japanese patent application filed on February 28, 2018 (Japanese Patent Application No. 2018-034870) and a Japanese patent application filed on July 27, 2018 (Japanese Patent Application No. 2018-141051). , The whole is incorporated by citation.

The laminated non-woven fabric of the present invention is highly productive, has a uniform texture, has a smooth surface, is excellent in texture and touch, and has high water resistance. Therefore, it is suitable as a moisture-permeable waterproof sheet and as a building material. It can be used.
Further, the use of the laminated non-woven fabric of the present invention is not limited to the above, and for example, industrial materials such as filters, filter base materials, electric wire presser winding materials, wallpaper, roofing materials, sound insulating materials, heat insulating materials, and sound absorbing materials. Building materials such as materials, wrapping materials, bag materials, signboard materials, living materials such as printing base materials, weed-proof sheets, drainage materials, ground reinforcement materials, sound insulation materials, civil engineering materials such as sound absorbing materials, solid materials, light-shielding sheets It can be used for agricultural materials such as, ceiling materials, and vehicle materials such as spare tire cover materials.

(A): Core portion (b): Sheath portion (c): First component (d): Second component

Claims (10)

A laminated non-woven fabric in which a spunbonded non-woven fabric layer and a melt-blown non-woven fabric layer are laminated, and the spunbonded nonwoven fabric layer is composed of composite fibers made of a thermoplastic resin (A1) and a polyethylene-based resin (A2), and the heat The plastic resin (A1) is a polyolefin resin (A1a) or a polyester resin (A1b), the melt blown nonwoven layer is composed of fibers made of the polyolefin resin (B), and further, composite fibers of the spunbonded nonwoven layer. The average single fiber diameter of the non-woven fabric is 6.5 to 11.9 μm, and the complex viscosity of the spunbonded non-woven fabric layer measured under the conditions of 230 ° C. and 6.28 rad / sec is 100 Pa · sec or less. .. The laminated non-woven fabric according to claim 1, wherein the water pressure resistance per unit basis weight is 15 mmH ₂ O / (g / m ² ) or more. The laminated nonwoven fabric according to claim 1 or 2, wherein the melt flow rate of the fiber made of the thermoplastic resin (A1) constituting the spunbond laminated nonwoven fabric is 155 to 850 g / 10 minutes. The laminated nonwoven fabric according to any one of claims 1 to 3, wherein the content of the melt-blown nonwoven fabric layer is 1% by mass or more and 15% by mass or less with respect to the mass of the laminated nonwoven fabric. The laminated nonwoven fabric according to any one of claims 1 to 4, wherein the surface roughness SMD of at least one surface by the KES method is 1.0 to 2.6 μm. The laminated nonwoven fabric according to any one of claims 1 to 5, wherein the average friction coefficient MIU by the KES method on at least one side is 0.1 to 0.5. The laminated nonwoven fabric according to any one of claims 1 to 6, wherein the fluctuation MMD of the average friction coefficient by the KES method on at least one side is 0.008 or less. The laminated nonwoven fabric according to any one of claims 1 to 7, wherein the polyethylene-based resin (A2) contains a fatty acid amide compound having 23 or more and 50 or less carbon atoms. The laminated nonwoven fabric according to claim 8, wherein the amount of the fatty acid amide compound added is 0.01 to 5.0% by mass. The laminated nonwoven fabric according to claim 8 or 9, wherein the fatty acid amide compound is ethylene bisstearic acid amide.

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