JP2009121014A - Laminated nonwoven fabric and method for production of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated nonwoven fabric formed of staple fiber layers and elastic laminated bodies, and having elasticity, which is hard to reduce width of elastic layers in production, and is hard to reduce width of elastic layers in processing after forming the laminated nonwoven fabric. <P>SOLUTION: The nonwoven fabric is formed by accumulating fibers containing a thermoplastic elastomer on one surface of the staple fiber layers formed of fibers with a fiber length of 0.5-20 mm, then bonding the staple fiber layers and the nonwoven fabric including fibers containing the thermoplastic elastomer to each other with the fibers containing the thermoplastic elastomer, and then laminating staple fiber layers formed of staple fibers having a fiber length longer than the fibers contained in the staple fiber layers, and then subjected to a hydroentanglement processing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a stretchable nonwoven fabric and a method for producing the same, and more particularly, a laminate comprising a stretchable nonwoven fabric made of a thermoplastic elastomer and a short fiber layer having a fiber length of 0.5 to 20 mm. The present invention relates to a laminated nonwoven fabric having an intermediate layer and a method for producing the same.

  A nonwoven fabric made of a thermoplastic elastomer is used as one layer of a laminated nonwoven fabric, and various nonwoven fabrics having a laminated structure as a whole have been proposed. For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2005-67201) includes a laminated structure of spunbond web / meltblown fiber layer / hydrophilic fiber layer / spunbond web, in which the meltblown fiber is made of an elastomer such as polyurethane. The body has been proposed.

  A stretchable nonwoven fabric having a three-layer structure has also been proposed. For example, Patent Document 2 (Japanese Patent Laid-Open No. 2002-1855) discloses a first layer of short fiber nonwoven web, a second layer of fibrous thermoplastic elastomer entangled web, and a third layer of short fiber non-woven fabric. A nonwoven fabric in which a woven web is laminated and integrated by heating is disclosed. Patent Document 3 (Japanese Patent Application Laid-Open No. 2002-4161) discloses a nonwoven fabric having the same laminated structure as the nonwoven fabric described in Patent Document 2 and integrated by heat and / or high-pressure columnar water flow. In Patent Document 4 (Japanese Patent Laid-Open No. 7-70902), the first layer is a short fiber web, the second layer is an elastic nonwoven fabric made of an elastomer, the third layer is a short fiber web, the first layer and the third layer. The fiber of the layer penetrates the second layer and is partially entangled, and the single fiber of the first layer and / or the third layer is partially dot-bonded by an adhesive and / or heat fusion, and is stretchable. A stretchable nonwoven fabric is disclosed which holds at least one direction.

  Each patent document shows a method for producing a stretchable nonwoven fabric. Specifically, Patent Document 1 proposes that a fiber laminate is formed by applying a layer made of melt blown fiber to a layer made of spunbond web and solidifying the layer assembly. In Patent Documents 2 and 3, a solution of an organic solvent of a thermoplastic elastomer is sprayed on a short fiber nonwoven web by an air stream, and is deposited in the form of short fibers under the volatilization of the solvent. Or it proposes manufacturing an elastic nonwoven fabric by performing the confounding process by a high-pressure columnar water stream. Patent Document 4 proposes that a stretchable nonwoven fabric is produced by passing a first layer of short fiber webs through a second layer of elastomer nonwoven fabric, forming a third layer, and then bonding by embossing. Yes.

JP-A-2005-67201 JP 2002-1855 A Japanese Patent Laid-Open No. 2002-4161 Japanese Patent Laid-Open No. 7-70902 JP-A-11-158766

  Thus, it is already known to obtain a stretchable nonwoven fabric by making one layer have stretchability in a nonwoven fabric having a laminated structure. And in the process of manufacturing such a nonwoven fabric, or in the process of manufacturing such a nonwoven fabric to manufacture another product, a phenomenon called “width-in” makes it difficult to manufacture the nonwoven fabric or the nonwoven fabric or nonwoven fabric. It is also known to adversely affect the quality of the product used.

  For example, as described in Patent Document 4, when a stretchable nonwoven fabric made of an elastomer is laminated and integrated with another fiber layer, the stretchable nonwoven fabric is pulled, that is, in the machine direction (machine direction). Direction). Such tension is required to keep the elastomeric nonwoven fabric from sagging during continuous production.

  However, when the elastomer nonwoven fabric is pulled in the longitudinal direction, it tends to easily stretch, deform, and become elongated, that is, the lateral dimension (width) tends to decrease. This decrease in width is a phenomenon called “with width”. This phenomenon occurs due to the low dimensional stability of the elastomer nonwoven fabric. If the width of the elastomeric nonwoven fabric is reduced during the production of the nonwoven fabric, there will be inconveniences such as a final product having a desired width not being obtained and variations in physical properties. The decrease in width, variation in physical properties, and the like are more prominent as the basis weight of the elastomer nonwoven fabric is smaller. The problem of width inclusion can also occur in the nonwoven fabric after lamination. For example, when the laminated nonwoven fabric is continuously supplied and integrated with other sheets, or when the opening is formed by punching, the laminated nonwoven fabric enters, and these operations are performed. Make it difficult.

  In addition, as a problem related to the processing of the nonwoven fabric having elasticity, when cutting (for example, cutting or punching) to a predetermined dimension, the portion hit by the blade is stretched, and the outline is likely to be bent (that is, a sharp outline is obtained). Is not possible). Furthermore, when a non-woven fabric having elasticity is cut, there is also a problem that the cut surface tends to fluff (short fibers come out perpendicular to the cut surface from the cut surface).

  The present invention has been made in view of these circumstances, and provides an elastic laminated nonwoven fabric that has a small width at the time of manufacture and processing, and that reduces drooping of the contour at the time of cutting, and a method for manufacturing the same The purpose is to do.

  The present inventor studied to obtain a nonwoven fabric that solves the above problems by forming a stretchable layer in advance and adopting a configuration obtained by integrating this layer with another fiber layer. As described in Patent Documents 2 and 3, a nonwoven fabric manufactured by a technique in which a thermoplastic elastomer is used as a solution and directly deposited on a short fiber nonwoven web in a short fiber form is obtained by depositing the elastomer in a short fiber form. This is because the stretchability of the formed layer appears strongly, and when the obtained non-woven fabric is processed later, it becomes easier to enter the width.

  Furthermore, the present inventors have studied to form a stretchable layer with a laminate of a stretchable fiber layer and a less stretchable fiber layer. Such a laminate is based on the idea that the non-stretchable fiber layer suppresses the width of the product during manufacture.

  The inventor pays attention to the technique disclosed in Patent Document 1 for applying a meltblown fiber made of an elastomer to a spunbond web, and a laminate in which the spunbond web (or nonwoven fabric) and the meltblown web (or nonwoven fabric) are integrated. Considered use of the body. A laminated nonwoven fabric obtained by integrating a spunbond nonwoven fabric and a meltblown nonwoven fabric is disclosed in, for example, Patent Document 5 (Japanese Patent Laid-Open No. 11-158766). However, spunbonded nonwoven fabrics (not composed of elastomer fibers) generally have high strength and elongation stress, and do not have stretchability. Therefore, it has been found that when the spunbond web is integrated with the elastomer nonwoven fabric, the stretchability of the elastomer nonwoven fabric tends to be inhibited, and the spunbond web is not suitable for use as a stretchable intermediate layer.

  Then, when the inventor repeated examination further, the short fiber layer which consists of a fiber with a fiber length of 0.5-20 mm is laminated | stacked on the surface of at least one of the elastic nonwoven fabric containing the fiber containing a thermoplastic elastomer. If the laminated body is used as a stretchable fiber layer located in the laminated nonwoven fabric and the shape of the laminated body is at least partially maintained in the nonwoven fabric having a laminated structure, the manufacturing process and after lamination In the process of processing the nonwoven fabric, the present inventors have found that the width is suppressed and the stretchability due to the stretchable nonwoven fabric appears in the laminated nonwoven fabric, and the present invention has been devised.

That is, the present invention
A laminate in which a short fiber layer composed of short fibers having a fiber length of 0.5 to 20 mm is laminated on at least one surface of a stretchable nonwoven fabric containing fibers comprising a thermoplastic elastomer, and at least one of the laminates A staple fiber layer comprising 50% by mass or more of staple fibers laminated on the surface of the fiber and having a fiber length longer than the fiber length of the fibers contained in the short fiber layer,
The staple fiber layer and the laminate are integrated by interlacing fibers, short fibers, and staple fibers comprising a thermoplastic elastomer.
A laminated nonwoven fabric is provided.

  This laminated nonwoven fabric is manufactured stably because the short fiber layer increases the dimensional stability of the elastomer nonwoven fabric to some extent and prevents the width of the elastomer nonwoven fabric from extending in the longitudinal direction during continuous processing. be able to. Moreover, since the short fiber layer at least partially constitutes one layer of the laminated nonwoven fabric even after being integrated with the staple fiber layer, it effectively prevents the width from entering when the laminated nonwoven fabric of the present invention is processed. . Furthermore, since the short fiber layer does not have a high strength like a spunbond web, it does not completely hinder the stretchability of the elastomer nonwoven fabric. Therefore, the laminated nonwoven fabric of the present invention exhibits the elasticity provided by the elastomer nonwoven fabric.

  In this laminated nonwoven fabric, at least one surface of the nonwoven fabric is formed of a staple fiber layer containing staple fibers having a fiber length longer than that of the fibers contained in the short fiber layer. Therefore, the texture and tactile sensation on the surface of the nonwoven fabric are governed by staple fibers, thereby making it possible to use a laminated nonwoven fabric for various purposes.

  The staple fiber layer preferably includes ultrafine fibers having a fineness of 0.5 dtex or less. By including such ultrafine fibers, a laminated nonwoven fabric having a dense surface and a smooth feel can be obtained.

  The ultrafine fibers are preferably formed, for example, by splitting split-type composite fibers. For example, when fibers are entangled by water flow, if split-type composite fibers are used, they can be easily handled as fibers with a large fineness before entanglement. Ultra fine fibers can be formed simultaneously.

  Alternatively, the staple fiber layer preferably contains cellulosic fibers. By including the cellulosic fiber, it is possible to obtain a stretchable nonwoven fabric with a soft tactile characteristic of the fiber. Cellulosic fibers are entangled well with the short fiber layer, for example, when the fibers are entangled with each other by a water flow.

  The cellulosic fiber is preferably cotton, for example. Since cotton has a track record of being widely used as a natural material, it is particularly preferably used when the laminated nonwoven fabric is used in contact with human skin. Further, by combining cotton, an elastomer nonwoven fabric, and a short fiber layer, a nonwoven fabric having excellent mechanical properties that cannot be obtained with a single-layer nonwoven fabric containing cotton can be realized.

  The elastomer nonwoven fabric is preferably a melt blown nonwoven fabric. Since melt-blown nonwoven fabrics are often provided with a relatively small basis weight, they are particularly prone to problems with width during manufacture. Therefore, the effect of the present invention can be effectively used when the elastomer nonwoven fabric is a melt blown nonwoven fabric.

  In the laminated nonwoven fabric of the present invention, the short fiber layer is preferably a nonwoven fabric containing 50% by mass or more of hydrophilic fibers. The hydrophilic fiber is particularly entangled with the staple fiber when the fibers are entangled and integrated by a water flow. Moreover, the short fiber layer containing hydrophilic fibers increases the rigidity of the entire laminated nonwoven fabric when the laminated nonwoven fabric is in a dry state, and facilitates continuous processing (particularly, cutting) of the nonwoven fabric. In addition, when the laminated nonwoven fabric is in a wet state, since the fibers constituting the wet nonwoven fabric can be easily unbonded and / or entangled, the entire laminated nonwoven fabric becomes soft, and the laminated nonwoven fabric can be stretched with a smaller force. It becomes.

  In the laminated nonwoven fabric of the present invention, the short fiber layer is preferably a wet papermaking nonwoven fabric made of pulp fibers. When the short fiber layer is made of pulp fibers, the difference between the rigidity when the laminated nonwoven fabric is in a dry state and the rigidity when it is in a wet state becomes larger. In addition, the short fiber layer made of pulp fibers is more entangled with staple fibers when the fibers are entangled with each other by a water flow.

  In the laminated nonwoven fabric of the present invention, it is preferable that the fiber comprising the thermoplastic elastomer, the short fiber, and the staple fiber are entangled with each other by hydroentanglement treatment. Laminated nonwoven fabrics in which fibers are entangled by hydroentanglement treatment, each layer effectively plays its role while having a good texture (that is, the short fiber layer reduces the width when processing laminated nonwoven fabrics) The elastomer nonwoven fabric imparts stretchability to the entire laminated nonwoven fabric).

The present invention also provides a method for producing the laminated nonwoven fabric. The production method of the present invention comprises:
A nonwoven fabric is formed by accumulating fibers containing a thermoplastic elastomer on one surface of a short fiber layer made of fibers having a fiber length of 0.5 to 20 mm, and an accumulated molten or softened thermoplastic elastomer A short fiber layer and a non-woven fabric including a fiber including a thermoplastic elastomer are bonded to each other by a fiber including the laminate to obtain a laminate;
A staple fiber layer containing staple fibers having a fiber length longer than the fiber length of the fibers contained in the short fiber layer is laminated on at least one surface of the laminate to obtain a multilayer laminate, and water flow in the multilayer laminate Including performing a confounding process. Here, the term “multilayer laminate” is used to distinguish from a laminate comprising an elastomer nonwoven fabric and a short fiber layer.

  This production method is characterized in that a laminate is prepared in advance, staple fiber layers are disposed on one or both sides of the laminate, and the fibers are integrated by hydroentanglement treatment. According to this production method, when the laminate is tensioned and the staple fiber layer is laminated and further subjected to hydroentanglement, the width of the laminate is hardly generated, and the laminated nonwoven fabric of the present invention is stably formed. It is possible to manufacture.

  In the production method of the present invention, it is preferable to form a laminate by fiberizing a resin comprising a thermoplastic elastomer by a melt blown method. According to this method, a laminate in which the elastomer nonwoven fabric is a meltblown nonwoven fabric can be easily obtained.

  The laminated nonwoven fabric of the present invention has a fiber length that is longer than the fiber length of the fibers constituting the short fiber layer on at least one surface of a laminate formed by laminating an elastic nonwoven fabric that is easily stretched and laminated on the short fiber layer. A staple fiber layer made of staple fibers is laminated and integrated. In this laminated nonwoven fabric, the laminated body itself functions as a layer responsible for stretchability, and the short fiber layer constituting the laminated body is generated during the production of the laminated nonwoven fabric and during the processing of the laminated nonwoven fabric itself and the laminated nonwoven fabric. Effectively suppresses the width of. Therefore, the laminated nonwoven fabric of the present invention can be produced stably and can be stably applied to continuous processing (for example, application or dipping of a treatment agent, cutting).

  Moreover, since the laminated nonwoven fabric of this invention contains the elastomer nonwoven fabric which has a stretching property as one constituent layer, and has the stretching property by an elastomer nonwoven fabric, it can be applied to the use for which a stretching property is required. Therefore, the laminated nonwoven fabric of the present invention includes a stretchable member (for example, a waist member), a sanitary mask, a wiper, and a makeup that constitute an absorbent article having an absorbent body such as a disposable diaper, a sanitary napkin, and a panty liner. It can be suitably used for industrial materials (such as cleansing sheets and face masks), gauze, adhesive plaster pads, automotive ceiling backings, chair backings and the like.

  The laminated nonwoven fabric of the present invention is a laminate comprising a short fiber layer laminated on at least one surface of a stretchable nonwoven fabric containing fibers comprising a thermoplastic elastomer, and comprising a stretchable elastomer nonwoven fabric and a short fiber layer. And a staple fiber layer laminated on both surfaces of the laminate. Here, the term “surface” refers to the main surface (surface perpendicular to the thickness direction) of the nonwoven fabric or layer.

[Laminate]
First, a stretchable nonwoven fabric (hereinafter, also referred to as “elastomer nonwoven fabric”) including fibers comprising a thermoplastic elastomer, which is one layer of the laminate, will be described. The fiber comprising the thermoplastic elastomer is a fiber comprising a resin containing 30% by mass or more of the thermoplastic elastomer, and preferably contains 50% by weight or more of the thermoplastic elastomer. Alternatively, the fiber comprising the thermoplastic elastomer may consist solely of the thermoplastic elastomer.

  Examples of thermoplastic elastomers (also simply referred to as “elastomers”) include styrene elastomers, polyolefin elastomers, ester elastomers, vinyl chloride elastomers, urethane elastomers, and amide elastomers. The elastomer nonwoven fabric is preferably composed of fibers containing a styrene-based elastomer and / or a polyolefin-based elastomer. These elastomers have good moldability, and when the laminated nonwoven fabric of the present invention is produced by the production method described later, it functions well as an adhesive component when integrated with the short fiber layer.

  The styrenic elastomer is preferably a copolymer containing a styrene component in an amount of 5% by weight to 70% by weight. Specific examples of styrene elastomers include styrene / butadiene block copolymer elastomers, styrene / isoprene block copolymer elastomers, styrene / butadiene / styrene block copolymer elastomers, and styrene / isoprene / styrene block copolymers. Examples thereof include elastomers and hydrogenated styrene / ethylene / butylene / styrene block copolymer elastomers and styrene / ethylene / propylene / styrene block copolymer elastomers. In the hydrogenated block copolymer, the hydrogen conversion rate is preferably 80% or more. These may be used alone or in combination of two or more.

  Specifically, the olefin elastomer is a random or block copolymer of two or more α-olefins selected from ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-octene, and the like. And those having a low crystallinity or non-crystallinity of less than 50% and an MFR in the range of 20 to 100 g / 10 min, preferably 50 to 80 g / 10 min. Specifically, as an olefin-based elastomer, an α-olefin random copolymer such as an ethylene / propylene random copolymer elastomer, an ethylene / 1-butene random copolymer elastomer, and a propylene / 1-butene random copolymer elastomer is used. And block copolymer elastomer of α-olefin such as ethylene / propylene block copolymer elastomer, ethylene / 1-butene random block copolymer elastomer, and propylene / 1-butene random block copolymer elastomer It is done.

  When the fiber containing the elastomer contains a resin other than the elastomer, the resin is preferably an olefin resin. Examples of the olefin resin include polypropylene, polyethylene, ethylene-α-olefin copolymer, propylene-α-olefin copolymer, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, and ethylene- (meth). An acrylic acid copolymer and an ethylene-methyl (meth) acrylate copolymer. These resins have good moldability and function well from the viewpoint of reducing the tackiness (adhesiveness) of the elastomer nonwoven fabric. The decrease in tackiness is required for smooth feeding when the laminated body is once wound up on a roll and fed out and used in the production of a laminated nonwoven fabric. Furthermore, these resins exhibit the effect of increasing the melting point of the fibers constituting the elastomer nonwoven fabric and making the elastomer nonwoven fabric difficult to cure in the drying step. Alternatively, a resin other than the olefin resin, for example, a polyester resin, a polyamide resin, or an acrylic resin may be used together with the elastomer.

  When the fiber containing an elastomer contains a resin other than the elastomer, the ratio is preferably 70% by mass or less. When the proportion of the resin other than the elastomer exceeds 70% by mass, good stretchability may not be obtained in the laminated nonwoven fabric. When the fiber which comprises an elastomer nonwoven fabric is formed with 2 or more resin, a fiber may be a composite form, for example, may be a core-sheath type composite fiber, a split type composite fiber, and a sea-island type composite fiber. Alternatively, the fiber may be a single fiber made of a mixed resin.

  When the elastomer nonwoven fabric includes fibers that do not contain an elastomer, the proportion of such fibers is preferably selected so that the elastomer resin occupies 30% by mass or more of the elastomer nonwoven fabric. The reason is as described above. The fiber not containing an elastomer is a synthetic fiber formed from a resin other than an elastomer, or a natural fiber or a regenerated fiber as described above. The synthetic fiber elastomer nonwoven fabric is preferably formed only of fibers containing an elastomer.

  An elastomer nonwoven fabric is comprised from the fiber containing an elastomer, or the fiber containing an elastomer, and the fiber which does not contain an elastomer. The form of the elastomer nonwoven fabric is not particularly limited, and may be any of an air-through nonwoven fabric, a thermal bonding nonwoven fabric, a wet papermaking nonwoven fabric, an airlaid nonwoven fabric, a hydroentangled nonwoven fabric, a needle punched nonwoven fabric, a spunbonded nonwoven fabric, and a meltblown nonwoven fabric. The elastomer nonwoven fabric is preferably a meltblown nonwoven fabric or a spunbond nonwoven fabric, more preferably a meltblown nonwoven fabric. When the elastomer nonwoven fabric is a spunbond nonwoven fabric or a meltblown nonwoven fabric, when the laminated nonwoven fabric of the present invention is produced by the method described later, the short fiber layer and the elastomer nonwoven fabric can be bonded and integrated simultaneously with the production of the elastomer nonwoven fabric. Also, it can be integrated with the short fiber layer with an appropriate adhesive strength. The meltblown nonwoven fabric is more preferably used because it is a nonwoven fabric in which fibers with small fineness are uniformly distributed and is flexible.

  When the elastomer nonwoven fabric is a melt blown nonwoven fabric, the average fiber diameter is preferably about 0.5 to 15 μm, and more preferably about 0.5 to 10 μm. It is difficult to make the fiber diameter 0.5 μm or less, and when it exceeds 15 μm, the texture becomes hard and the stretchability may be lowered. The average fiber diameter is obtained by observing an elastomer nonwoven fabric 50-500 times enlarged with an electron microscope, randomly selecting 20 fibers constituting the nonwoven fabric, measuring the fiber diameter, and calculating the average value. . The meltblown nonwoven fabric can be manufactured according to a normal method. As will be described later, the laminate before being integrated with the staple fiber layer is a method of accumulating fibers on the short fiber layer, and simultaneously producing the melt blown nonwoven fabric and integrating the melt blown nonwoven fabric with the short fiber layer. And it is preferable that it is what was obtained.

  When the elastomer nonwoven fabric is a spunbond nonwoven fabric, the average fiber diameter is preferably about 7 to 50 μm, and more preferably about 10 to 25 μm. When the average fiber diameter exceeds 50 μm, the texture becomes hard and the stretchability may be lowered. As will be described later, the laminate before being integrated with the staple fiber layer is a method of accumulating fibers on the short fiber layer, and the production of the spunbond nonwoven fabric and the integration of the spunbond nonwoven fabric and the short fiber layer are performed. It is preferable that it is obtained by carrying out simultaneously.

May take any form, basis weight of the elastomeric nonwoven is preferably 5 to 50 g / ^{m 2,} more preferably from 5~35g / ^{m 2,} still to be 5 to 25 g / ^{m 2} More preferred. If the basis weight of the elastomer nonwoven fabric is less than 5 g / m ² , the stretchability may not be sufficient, and if it exceeds 50 g / m ² , the dimensional stability becomes high, and the width can be obtained without being integrated with the short fiber layer. This is because problems such as entering are less likely to occur. However, since the problem of tackiness is found in any non-woven elastomer nonwoven fabric, from the viewpoint of avoiding inconveniences due to tackiness, the non-woven fabric of fabric weight outside the range mentioned here is also the present invention. Are preferably used.

Further, the elastomer nonwoven fabric, when taking any form, in any one direction of the nonwoven fabric, the strain at 100% elongation is preferably less than 60%, more preferably less than 50%, and even more Preferably it is less than 40%. Here, the strain at 100% elongation is measured by the following method.
[Distortion at 100% elongation]
Using a constant-speed tension type tensile tester according to JIS L 1096 6.12.1 A method (strip method) (2007), the sample was 5 cm in width, 10 cm in the grip interval, and 10 ± in tensile speed. It is subjected to a tensile test under the condition of 3 cm / min, stretched 100%, relaxed at the same speed, and the length L of the gripping interval when the elongation stress at the time of elongation (return path elongation stress) becomes zero (Cm) (3 significant digits) is measured, and the strain at 100% elongation is obtained from the equation of strain (%) = {(L-10.0) /10.0} × 100.

  Next, the short fiber layer will be described. The short fiber layer is a layer composed of short fibers having a fiber length of 0.5 to 20 mm. The fiber length of the short fibers is preferably 0.5 to 15 mm, more preferably 0.8 to 10 mm, and even more preferably 1 to 5 mm. All the short fibers constituting the short fiber layer may have the same length or different lengths. The average fiber length of the short fibers is measured according to JIS L1015 8.4.1 A method (staple diagram method) (2007). When the short fibers are pulp, the number average fiber length is obtained by measuring according to JIS P8226 (pulp-fiber automatic measuring method fiber length measuring method) (2006).

  The short fiber layer may generally be in the form of an air laid web or a wet nonwoven before being integrated with the staple fiber layer. The wet nonwoven fabric includes paper made of cellulose-based short fibers described later. In the present invention, the short fiber layer is preferably a wet nonwoven fabric. Although the wet nonwoven fabric depends on the constituent fibers and the degree of entanglement of the fibers, the wet nonwoven fabric can be subjected to continuous processing as an integrally held form. In general, wet nonwoven fabrics are low in volume (thin), and therefore have good entanglement with water flow and needles. Furthermore, when the wet nonwoven fabric is entangled with each other by hydroentanglement treatment, the wet nonwoven fabric can be processed with a reduced water pressure, so that the texture of the entire laminated nonwoven fabric can be softened. Furthermore, the wet nonwoven fabric has a small difference in physical properties due to a difference in direction (longitudinal direction, lateral direction) due to its manufacturing method. Therefore, when the laminated nonwoven fabric in which the wet nonwoven fabric is a short fiber layer, particularly when subjected to a cutting process, due to the difference in the direction of the blade, the variation in the degree of “sag” occurs in one contour, or Variations can be reduced.

  The fiber constituting the short fiber layer may be any of natural fiber, regenerated fiber, and synthetic fiber. The short fiber layer may be composed of one type of short fiber or may be composed of two or more different fibers.

  The fibers constituting the short fiber layer are preferably made of a material that does not contain a thermoplastic elastomer. If the short fiber contains a thermoplastic elastomer, the effect of suppressing the width of the elastomer nonwoven fabric by the short fiber layer may not be obtained.

  In the present invention, the short fiber layer preferably includes a short fiber having hydrophilicity. By making the short fiber layer hydrophilic, when the fibers are entangled by hydroentanglement treatment, the entanglement between the staple fiber layer and the short fiber layer becomes strong, and a laminated nonwoven fabric with a large elongation stress is obtained. be able to. In addition, when the short fiber layer is a hydrophilic layer, in the laminated nonwoven fabric of the present invention, the short fiber layer becomes a liquid retaining layer, and the laminated nonwoven fabric is used by impregnating, for example, cosmetics, detergents or chemicals. Can be preferably used. The hydrophilic fiber is preferably contained in the short fiber layer in an amount of 50% by mass or more, more preferably 70% by mass or more, and most preferably 100% by mass.

  The hydrophilic short fiber is more preferably a cellulose short fiber. Cellulosic fibers refer to fibers made of cellulose or containing cellulose as a main component. More specifically, the cellulose fibers are pulps such as mechanical pulp, regenerated pulp and chemical pulp; viscose rayon, cupra, and solvent-spun cellulose fibers (for example, lentung lyocell (registered trademark) and tencel (registered trademark)), etc. Regenerated fibers; and plant-based natural fibers such as hemp (including bast fibers and fibers collected from leaf stems or leaves), cotton (cotton), and the like.

  The pulp fibers may be produced by conventional methods using coniferous wood or hardwood wood. In general, the fineness of the pulp fiber is about 1.0 to 4.0 dtex and the fiber length is about 0.5 to 4.5 mm. However, pulp having a fineness and / or fiber length outside this range is used. May be. The short fiber layer consisting of pulp fibers can be provided as an airlaid web or wet nonwoven, or it can also be provided as flocculent pulp (fluff pulp).

  As described above, wet nonwoven fabrics containing or consisting solely of pulp fibers include paper. Paper containing or consisting of pulp fibers includes tissue (also referred to as tissue paper). The short fiber layer containing pulp fibers may be composed only of pulp fibers, or may be composed of pulp fibers and other fibers. The other fibers may be cellulose short fibers other than pulp (for example, cotton, viscose rayon and solvent-spun cellulose fibers) or synthetic fibers (for example, polypropylene fibers and polyester fibers). A wet nonwoven fabric made of pulp fibers is preferably used because it imparts hydrophilicity to the laminated nonwoven fabric and increases the degree of entanglement when the fibers are entangled by hydroentanglement treatment. When a wet nonwoven fabric made of pulp fibers is used as a short fiber layer, the rigidity of the resulting laminated nonwoven fabric increases. Therefore, when the laminated nonwoven fabric is cut particularly, a product having a sharp outline can be obtained without any outline.

  When using recycled fiber, the fineness is preferably about 0.5 to 6 dtex, more preferably about 0.5 to 5 dtex. If the fineness of the regenerated fiber is too small, the short fiber layer becomes too dense.For example, as will be described later, when the layers constituting the laminated nonwoven fabric are integrated by the hydroentanglement process, it is difficult for water to pass through. A fiber layer and / or a staple fiber layer may be disturbed, and the surface state of the laminated nonwoven fabric obtained may deteriorate. When the fineness of the regenerated fiber is too large, unevenness of formation becomes large, and when the layers constituting the laminated nonwoven fabric are integrated by the hydroentanglement process, the interlace of fibers may be insufficient. The short fiber layer containing the regenerated fiber is preferably provided in the form of a wet nonwoven fabric. The reason is as described above.

  The short fiber layer may be formed of natural fibers or synthetic fibers other than cellulosic fibers. Natural fibers are, for example, silk and wool, and synthetic fibers are ethylene, vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, ethylene, such as polyethylene, polypropylene, polymethylpentene, or ethylene-propylene copolymer. -Polyolefin fiber made of (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid methyl copolymer, polyester fiber made of polyethylene terephthalate or polybutylene terephthalate, polyamide fiber made of nylon 6 or nylon 66, etc. And acrylic fibers. The synthetic fiber may be a composite fiber, specifically, a core-sheath type composite fiber, an eccentric core-sheath type composite fiber, or a split type composite fiber. These fibers may be subjected to a hydrophilic treatment as necessary.

The basis weight of the short fiber layer is appropriately selected according to the basis weight of the laminate and the laminated nonwoven fabric to be obtained, the basis weight of the laminated elastomer nonwoven fabric, and the like. For example, when the basis weight of the elastomer nonwoven fabric is 5 to 50 g / m ² as described above, the basis weight of the short fiber layer is preferably 5 to 50 g / m ² , and more preferably 10 to 40 g. / M ² , more preferably 12 to 30 g / m ² . When the basis weight of the short fiber layer is less than 5 g / m ² , the strength of the short fiber layer becomes too weak, and the short fiber layer may be broken by the tension applied when the staple fiber layer is laminated on the laminate. If it exceeds 50 g / m ² , in the finally obtained laminated nonwoven fabric, the stretch properties of the elastomer nonwoven fabric do not appear, and the stretch properties of the short fiber layer may be dominant.

  The elastomeric nonwoven fabric and the short fiber layer of the laminate are bonded with fibers containing a thermoplastic elastomer before being integrated with the staple fiber layer, and after being integrated with the staple fiber layer, in part, It may exist in the state adhered by the fiber containing a plastic elastomer. Thereby, stabilization of the laminated nonwoven fabric by a short fiber layer becomes higher. Or the laminated body which the short fiber layer and the elastomer nonwoven fabric adhere | attached may exist in the state from which adhesion | attachment was cancelled | released, after integrating with a staple fiber layer. Alternatively, the elastomeric nonwoven fabric and short fiber layers of the laminate may be independent of each other and simply stacked before being integrated with the staple fiber layer without being bonded and / or entangled.

Basis weight of the laminate, in accordance with the application etc., by selecting the basis weight of the elastomeric nonwoven and the short fiber layer is determined, for example, is preferably from 10 to 100 g / ^{m 2,} with 10 to 60 g / ^{m 2} More preferably, it is more preferably 20 to 40 g / m ² . If the basis weight of the laminate is too small, at least one of the elastomer nonwoven fabric and the short fiber layer is uneven, and it is difficult to obtain good stretch properties. If the basis weight of the laminate is too large, the cost increases and it is not economical. In addition, if the basis weight is too large, the fibers may not be easily entangled when the hydroentanglement process is performed.

  In the laminate, the short fiber layer may be located only on one surface of the elastomer nonwoven fabric, or the short fiber layer may be located on both surfaces of the elastomer nonwoven fabric. Alternatively, the laminate may have a configuration of elastomer nonwoven fabric / short fiber layer / elastomeric nonwoven fabric.

[Staple fiber layer]
The staple fiber layer is composed of staple fibers whose fiber length is longer than the fiber length of the fibers constituting the short fiber layer. More strictly speaking, the staple fibers require that the average fiber length of the staple fibers is longer than the average fiber length of the fibers constituting the short fiber layer. In general, the average fiber length of the staple fibers is preferably in the range of 10 to 100 mm, more preferably in the range of 20 to 100 mm, and even more preferably in the range of 30 to 80 mm. The average fiber length of the fibers constituting the short fiber layer and the staple fiber layer is measured according to JIS L1015 8.4.1 A method (staple diagram method). The staple fiber layer may contain fibers shorter than the average fiber length of the short fiber layer as long as the average fiber length is longer than the average fiber length of the fibers constituting the short fiber layer.

  By arranging the staple fiber layer on one or both sides of the laminated nonwoven fabric, the elasticity of the elastomer nonwoven fabric is exhibited well, and the fibers of the short fiber layer and the fibers constituting the surface of the laminated nonwoven fabric are entangled well. Thus, a nonwoven fabric in which the layers are bonded with strong strength can be obtained. Staple fibers are preferred because they have good entanglement and do not significantly impair the stretchability of the elastomer nonwoven fabric.

  It should be noted that a fiber layer composed only of fibers other than staple fibers, for example, a fiber layer obtained by the melt blown method and the spunbond method, and a fiber layer composed of a wet papermaking nonwoven fabric have almost no extensibility and the elasticity of the middle layer elastomer nonwoven fabric. Tend to inhibit. Moreover, the fibers constituting these nonwoven fabrics are difficult to entangle.

  The staple fiber layer preferably contains 50% by mass or more of staple fibers, more preferably contains 80% by mass or more, and most preferably comprises only staple fibers. As fibers other than staple fibers, the staple fiber layer may include continuous filaments formed by a spunbond method or a meltblown method.

  The material of the staple fiber is not particularly limited. For example, one or more of natural fibers such as cotton, silk, and wool, regenerated fibers such as viscose rayon, cupra, and solvent-spun cellulose fibers (lyocell), and synthetic fibers are used. Selected. Specifically, solvent-spun cellulose fibers are marketed under the names Lentigryocell (registered trademark) and Tencel (registered trademark). Synthetic fibers include polyolefin fibers such as polyethylene, polypropylene, polymethylpentene, and ethylene-propylene copolymers, polyester fibers such as polyethylene terephthalate and polybutylene terephthalate, polyamide fibers such as nylon 6 and nylon 66, and acrylic fibers. Based fibers. The synthetic fiber may be a composite fiber, specifically, a core-sheath type composite fiber, an eccentric core-sheath type composite fiber, or a split type composite fiber. In the case of using split-type composite fibers, as will be described later, in the staple fiber layer finally obtained, ultrafine fibers formed by splitting the fibers into components are present.

  When the staple fiber is a synthetic fiber, the synthetic fiber is preferably formed of a material that does not contain a thermoplastic elastomer or a material that contains less than 30% by weight, if any. The synthetic fiber which does not contain the thermoplastic elastomer or contains a small amount prevents the surface of the laminated nonwoven fabric from having tackiness. In addition, if the staple fiber layer contains fibers containing a large amount of thermoplastic elastomer, the staple fiber layer is excessively stretchable, and even if it has a short fiber layer, the width at the time of processing is reduced. It may not be effectively prevented.

  In the laminated nonwoven fabric of the present invention, the staple fiber layer preferably contains ultrafine fibers having a fineness of 1 dtex or less. By containing ultrafine fibers, a smooth nonwoven fabric with a dense surface can be obtained. The fineness of the ultrafine fiber is more preferably 0.5 dtex or less. When the fineness of the ultrafine fiber exceeds 1 dtex, the above effect due to the inclusion of the ultrafine fiber may not be obtained. The lower limit of the fineness of the ultrafine fiber is not particularly limited, but is preferably 0.01 dtex or more in consideration of the wear resistance of the laminated nonwoven fabric surface.

  The ultrafine fibers are preferably contained in the staple fiber layer in an amount of 10% by mass or more, more preferably 50% by mass or more. When the ratio of the ultrafine fiber is less than 10% by mass, the above effect due to the inclusion of the ultrafine fiber may not be obtained.

  The ultrafine fibers are preferably those formed by splitting split-type composite fibers. The reason is as described above. Specifically, the split-type conjugate fiber is formed by dividing at least one component of the constituent components into two or more in the fiber cross section, and at least a part of the constituent components are exposed on the fiber surface, and the exposed portion is the fiber. It has a fiber cross-sectional structure formed continuously in the length direction. Preferable combinations of polymers constituting the split-type composite fibers are polyethylene terephthalate / polyethylene, polyethylene terephthalate / polypropylene, polyethylene terephthalate / ethylene-propylene copolymer, polypropylene / polyethylene, polyethylene terephthalate / nylon, and the like.

  Alternatively, the staple fiber layer preferably contains cellulosic fibers. The meaning of “cellulosic fiber” is as described above in connection with the short fiber layer. The fibers suitable for constituting the staple fiber layer exemplified above are classified by paying attention to the generation process. The term “cellulosic fiber” is used to represent one type when classified by the main component, regardless of the production process. Cellulosic fibers suitable for the staple fiber layer include, specifically, regenerated fibers such as viscose rayon, cupra, and solvent-spun cellulose fibers (e.g., lentung lyocell (registered trademark) and tencel (registered trademark)); and hemp Plant-based natural fibers (including bast fibers and fibers collected from leaf stems or leaves) and cotton (cotton).

  A suitable cellulosic fiber for the staple fiber layer is cotton. Cotton has a long history of use as a natural material and is widely used as a material for clothing, underwear and hygiene materials, giving the general consumer the impression that it is skin-friendly, tactile and safe. ing. Therefore, the use of cotton can provide a product that is more easily accepted by consumers. In addition, non-woven fabrics made of only cotton or a mixture of cotton and other fibers are generally inferior in mechanical properties. For example, when wrinkles (or folds) are made on the non-woven fabric, the non-woven fabric is torn. There is. However, when cotton is used as the staple fiber layer and this is arranged on one side or both sides of the laminated nonwoven fabric of the elastomer nonwoven fabric / short fiber layer, the mechanical properties are improved, and the wrinkles (or creases) are easily formed. be able to.

  As the cotton, those generally used for nonwoven fabric production can be arbitrarily used. Specifically, cotton having a fiber length (average fiber length) of about 20 to 60 mm can be used. The staple fiber layer may include a plurality of cottons having different fiber lengths and types. When the configuration of the laminated nonwoven fabric of the present invention is adopted, the staple fiber layer in which a long fiber length and a short fiber length are mixed is a staple fiber layer composed only of a long fiber length (generally giving a better feel). Gives the same feel. The reason is not clear, but this allows the use of cheap cotton. For example, as long as the fiber length (average fiber length) of the staple fiber layer is shorter than the fiber length (average fiber length) of the fibers constituting the short fiber, for example, cotton having a fiber length of about 10 mm (eg, combed cotton fallen) ).

  When using split-type conjugate fibers, the split-type conjugate fibers are preferably contained in the staple fiber layer before hydroentanglement treatment by 50% by mass or more, and more preferably 80% by mass or more. In the staple fiber layer after the hydroentanglement treatment, the split-type composite fiber does not need to be completely divided into the respective constituent components. However, one or a plurality of ultrafine fibers may be branched from one split type composite fiber. As described above, when the division of the ultrafine fiber in the split type composite fiber is stopped halfway, it may be difficult to obtain the ratio of the ultrafine fiber in the staple fiber layer. In consideration of this, it should be noted that in the above, the staple fiber layer constituting the laminated nonwoven fabric of the present invention is specified by the ratio of the split type composite fibers before hydroentanglement.

The basis weight of the staple fiber layer is preferably 15 g / m ² or more and 50 g / m ² or less regardless of which fiber is used. A more preferred basis weight of the staple fiber layer is 20 g / m ² or more and 40 g / m ² or less. If the basis weight of the staple fiber layer is less than 15 g / m ² , the thickness of the staple fiber layer becomes small, so that the fibers constituting the short fiber layer may be exposed on the surface and fall off. If the basis weight of the staple fiber layer exceeds 50 g / m ² , the fibers may be insufficiently entangled. In particular, when the laminated nonwoven fabric of the present invention is integrated by hydroentanglement treatment, the elastomer nonwoven fabric serves as a barrier against the water flow, and if the basis weight of the staple fiber layer is too large, the integration between the layers by the hydroentanglement treatment is not possible. It tends to be insufficient.

  The form before the staple fiber layer is integrated with the other fiber layers is not particularly limited, and may be from a card web such as a parallel web, a cross web, a semi-random web and a random web, an air lay web, and a wet papermaking web. Any form may be selected. In consideration of processability and texture, the staple fiber layer is preferably a card web.

[Laminated nonwoven fabric]
Next, the laminated nonwoven fabric of the present invention formed by laminating the above layers will be described together with the production method thereof.

In the laminated nonwoven fabric of the present invention, a staple fiber layer is laminated on at least one surface of the laminate, and fibers comprising a thermoplastic elastomer, short fibers, and staple fibers are entangled and integrated. It is a nonwoven fabric. The laminated nonwoven fabric of the present invention has a basis weight in which the basis weight of each layer is within the above-mentioned preferable range, and has a basis weight in the range of ^{20 to} 260 g / m ² as a whole. Has a basis weight in the range of 50 to 180 g / m ² , and even more preferably has a basis weight in the range of 60 to 140 g / m ² . When the basis weight of the laminated nonwoven fabric is small, the basis weight of any one or more layers is small, and the desired effect (reduction in width during manufacturing and processing, imparting stretchability by the elastomer nonwoven fabric) is obtained. It may not be possible. When the basis weight of the laminated nonwoven fabric is large, any one layer or a plurality of basis weights may be large, and the desired effect may not be obtained.

  When the laminated nonwoven fabric of the present invention is constructed by laminating the staple fiber layer only on one surface of the laminate in which one surface of the laminate is the surface of the elastomer nonwoven fabric and the other surface is the surface of the short fiber layer, The staple fiber layer may be disposed on either side. When the staple fiber layer is arranged on the elastomer nonwoven fabric side, the entanglement between the staple fiber layer and the elastomer nonwoven fabric becomes stronger, and the staple fiber layer easily follows the expansion and contraction of the elastomer nonwoven fabric, and there is less fuzzing and coming off of the staple fibers during the expansion and contraction. Become. When the staple fiber layer is arranged on the short fiber layer side, the entanglement between the staple fiber layer and the short fibers becomes stronger, and the short fibers are not exposed on the surface, so that the short fibers are difficult to fall off.

  In the laminated nonwoven fabric of the present invention in which the layers are entangled and integrated, the laminated body still exists as a laminated body at least partially. That is, when the cross section of the laminated nonwoven fabric is observed, at least a part of each layer can be clearly identified, and the short fiber layer and the elastomer nonwoven fabric are each present as one layer. Thus, even when the nonwoven fabric of the present invention is further subjected to continuous processing, it is difficult for the width to enter, and the stretchability of the elastomer nonwoven fabric becomes apparent.

  Since the laminated nonwoven fabric of the present invention is also covered with the staple fiber layer on both sides of the laminate, the appearance and surface feel and texture are governed by the staple fiber layer, for example, the tackiness of the elastomer nonwoven fabric, The fluff of the short fiber layer is not seen. Therefore, the nonwoven fabric of the present invention can be used as a nonwoven fabric with added elasticity in an application in which a nonwoven fabric using the fiber is normally used by appropriately selecting fibers constituting the staple fiber layer. .

  The laminated nonwoven fabric of the present invention is preferably produced using hydroentanglement treatment. Below, the method of manufacturing the laminated nonwoven fabric of this invention using a hydroentanglement process is demonstrated.

  First, a laminated body is manufactured. In the laminated body, fibers comprising a thermoplastic elastomer are accumulated on one surface of a short fiber layer made of fibers having a fiber length of 0.5 to 20 mm to form a nonwoven fabric, and the melted or softened material is accumulated. It is preferable to obtain a short fiber layer and a non-woven fabric including a fiber including a thermoplastic elastomer by bonding with a fiber including a thermoplastic elastomer. When a laminate is produced by this method, the nonwoven fabric formed by accumulating fibers comprising a thermoplastic elastomer stretches 100% in any one direction when accumulated without a short fiber layer. It is preferable to have elasticity that causes strain at time to be less than 50%, and more preferable to have elasticity that allows strain at time of 100% elongation to be less than 40%.

  The short fiber layer and the elastomer nonwoven fabric are preferably integrated with a peel strength of 3 to 300 mN / 5 cm, more preferably integrated with a peel strength of 3 to 100 mN / 5 cm, most preferably 3 to 50 mN / 5 cm. Powerful and integrated. If the peel strength is too small, the laminate is easily peeled off and the handleability is deteriorated. If the peel strength is too large, the stretchable properties of the elastomer nonwoven fabric may not be sufficiently obtained in the finally obtained laminated nonwoven fabric.

  In order to bond the two in such a manner, the laminate is preferably manufactured by a method comprising manufacturing an elastomeric nonwoven fabric by a method of accumulating molten fibers on the short fiber layer. The fiber accumulation is preferably carried out by a meltblown method or a spunbond method. When the thermoplastic elastomer fibers are accumulated on the short fiber layer by the melt blown method or the spun bond method, the fibers immediately after the accumulation are melted or softened. The fibers of the short fiber layer are bonded. The fiber accumulation can be carried out by a melt blown method or a spun bond method that is usually employed. That is, a laminated body can be manufactured by disposing a short fiber layer on a collection belt for collecting fibers and carrying out a melt blown method or a spun bond method. If necessary, after accumulating, pressure may be applied to increase the degree of bonding between the two.

  More specifically, the melt blown method is a short fiber placed on a collecting belt by melt-extrusion of resin, blown fiber spun from a melt blown spinneret as a fine fiber flow by high-temperature and high-speed gas, and placed on a collection belt This can be done by collecting on the layer. In the spunbond method, resin is melt-extruded from an extruder, resin is spun from a spinneret, and the spun fiber is taken up by an air-flow traction type device such as air soccer. It can be carried out by collecting the fibers on the short fiber layer placed on the web collecting device and then bonding the fibers to each other using a heating device such as a hot air spraying device or a heating roll, if necessary. .

  When the short fiber layer is positioned on both surfaces of the elastomer nonwoven fabric, after the elastomer nonwoven fabric is formed on the short fiber layer by the above method, the fiber containing the thermoplastic elastomer is melted or softened. A fiber layer is laminated | stacked, a pressure is applied as needed and it is made to adhere.

  Or you may prepare an elastomer nonwoven fabric and a short fiber layer separately, and may join them by heat processing, such as a hot roll or a hot-air spraying method. In that case, it is necessary to appropriately set the heat treatment conditions so that the bonding between the elastomer nonwoven fabric and the short fiber layer does not become too strong.

Further, the hydroentanglement treatment may be performed after the elastomer nonwoven fabric and the short fiber layer are bonded with the fibers of the elastomer nonwoven fabric. When the hydroentanglement process is performed, the joint strength between the two increases. The hydroentanglement treatment is preferably performed from the short fiber layer side so that the short fibers are entangled with the fibers constituting the elastomer nonwoven fabric. The hydroentanglement treatment conditions are appropriately set according to the basis weight of the elastomer nonwoven fabric and the short fiber layer and the bonding strength of both in the laminate. For example, when the basis weight of the elastomer nonwoven fabric and the short fiber layer is 10 to 100 g / m ² , the web is placed on a plain weave support of 80 to 100 mesh, and the hole diameter is 0.05 mm or more and 0.5 mm. The water entangling treatment is performed by injecting a water flow of 2 MPa or more and 10 MPa or less of water pressure from the side of the short fiber layer 1 to 3 times from a nozzle in which the following orifices are provided at intervals of 0.3 mm to 1.5 mm. May be implemented.

  The laminate obtained as described above is a laminate in which the mechanical properties of the short fiber layer are dominant at a low elongation rate, and the mechanical properties of the elastomer nonwoven fabric are dominant at a high elongation rate. When this laminate is stretched in the machine direction, the stress increases at a low stretch rate, and when the stretch rate reaches a range of 3 to 30%, the short fiber layer breaks. , The stress decreases rapidly. Thereafter, the expansion / contraction promotion of the elastomer nonwoven fabric becomes dominant, and even if the elongation rate is increased, a low stress is exhibited.

  In the laminate in which the elastomer nonwoven fabric and the short fiber layer are bonded and integrated, the elongation rate at which the elongation stress is maximized is 3 to 30%, preferably 5 to 20%, most preferably 8 to 18 as described above. %. When the elongation rate at which the elongation stress is maximum is 3% or more, the short fiber layer is not broken by the tension applied during continuous processing. When the elongation rate at which the elongation stress is maximized is 30% or less, the short fiber layer breaks when the elongation is increased, and the elastic properties of the elastomer nonwoven fabric are exhibited.

  In the laminate in which the elastomer nonwoven fabric and the short fiber layer are bonded and integrated, the maximum elongation stress when stretched in the machine direction (hereinafter, this stress is also referred to as “maximum stress”) is preferably 1 to 20 N / 5 cm. More preferably, it is 1.5-15N / 5cm, Most preferably, it is 2-12N / 5cm. If the maximum stress is less than 1 N / 5 cm, the short fiber layer may break due to the tension applied during continuous processing. When the maximum stress exceeds 20 N / 5 cm, the stretch characteristic of the elastomer nonwoven fabric does not appear, and is easily dominated by the stretch characteristic of the short fiber layer.

  Next, a multilayer structure (usually three layers (short fiber layers are arranged on only one surface of the elastomer nonwoven fabric, and the staple fiber layers are elastomer nonwoven nonwoven fabrics or short fibers) so that the staple fiber layers are located on both surfaces of the laminate. (When arranged on the surface of the fiber layer) to 5 layers (when the short fiber layer is arranged on both surfaces of the elastomer nonwoven fabric, or when the elastomer nonwoven fabric is arranged on both surfaces of the short fiber layer) In this case, the staple fiber layer may be in a web state in which the fibers are not entangled or very entangled.

  In the multilayer laminate, the staple fiber layer may be in any form selected from a card web, an air lay web, a wet papermaking web, and the like as described above. Moreover, in the laminated nonwoven fabric finally obtained, when the staple fiber layer is a layer including an ultrafine fiber layer having a fineness of 1 dtex or less formed by splitting the split composite fiber, the split composite fiber is: The staple fiber layer of the multilayer laminate is preferably contained in an amount of 50% by mass or more, and more preferably 80% by mass or more.

  This multilayer laminate is subjected to hydroentanglement treatment. At this time, when the staple fiber layer includes split-type composite fibers, the split-type composite fibers are split to form ultrafine fibers. The hydroentanglement treatment may be carried out by a known method, and the condition depends on the basis weight of the laminated nonwoven fabric to be finally obtained and the desired split fiber degree when using the split type composite fiber. You may set suitably. In the hydroentanglement treatment, for example, a web is placed on a plain weave support of 80 to 100 mesh, and orifices having a hole diameter of 0.05 mm to 0.5 mm are provided at intervals of 0.3 mm to 1.5 mm. You may implement by injecting a water flow 1 MPa or more and 10 MPa or less from a nozzle 1 to 4 times each from the front and back side. In particular, when the hydroentanglement treatment is performed at a low water pressure of less than 7 MPa, it is possible to suppress the short fibers from being exposed to the surface.

  When the staple fiber layer contains more than 50% by mass of cellulosic fibers, the same level of machine can be used even if the water pressure is lower than when the staple fiber layer contains more than 50% by mass of synthetic fibers. Characteristics, in particular, expansion and contraction characteristics can be realized. This is considered to be because cellulosic fibers generally have hydrophilicity. Therefore, when cellulosic fibers are used as the main component of the staple fiber layer, a hydroentangled nonwoven fabric having a soft tactile sensation in which fibers are intertwined with a low-pressure water stream can be obtained.

  Due to the hydroentanglement treatment, the adhesion between the short fiber layer and the elastomer nonwoven fabric is broken, and in the obtained laminated nonwoven fabric, the short fiber layer and the elastomer nonwoven fabric may be integrated only by entanglement of fibers. Even in such a case, the effect of the short fiber layer (decrease in the width of the nonwoven fabric, etc.) and the effect of the elastomer nonwoven fabric (ensure the stretchability of the entire laminated nonwoven fabric) can be sufficiently obtained.

  When the laminate is a two-layer structure consisting of an elastomer / short fiber layer, preferably the water stream is jetted from the side of the staple fiber layer adjacent to the elastomeric nonwoven fabric of the laminate and then adjacent to the short fiber layer of the laminate. Sprayed from the side of the staple fiber layer to be performed. By spraying the water flow in this order, the short fiber layer is hardly broken in the laminated nonwoven fabric, and can be more reliably left as one layer.

  In the laminated nonwoven fabric manufactured by performing the water entanglement process, the portion where the water flow is injected may form a striped recess. In the said recessed part, since the short fiber which comprises a short fiber layer scattered to circumference | surroundings, the quantity of a short fiber has decreased and thickness is small. In this part, the multi-layer structure may be broken, and it may be partially a two-layer structure of staple fiber layer / elastomer nonwoven fabric, or a three-layer structure of staple fiber layer / elastomeric nonwoven fabric / staple fiber layer. In the part, a multilayer structure remains. Therefore, when the laminated nonwoven fabric of the present invention is produced using hydroentanglement treatment, the desired effects of the present invention (reduction in width and elongation during continuous processing, and manifestation of stretchability by the elastomer nonwoven fabric) are achieved. It becomes easy to obtain a laminated nonwoven fabric.

  When the short fiber layer is a wet non-woven fabric made of pulp fibers, the pulp fibers may be rearranged due to splashing of the pulp fibers at the location where the water flow is applied due to the hydroentanglement treatment. The rearrangement of the pulp fibers makes it possible to reduce (control) the initial stress (stress until the pulp layer breaks) of the laminated nonwoven fabric. In addition, the rearrangement of the pulp fibers makes it easy for the pulp layer to hold the liquid and improves the water retention.

  Or you may manufacture the laminated nonwoven fabric of this invention by the method of integrating a laminated body and a staple fiber layer with a needle punch. Alternatively, the laminated nonwoven fabric of the present invention may be manufactured by combining needle punch and hydroentanglement treatment. Or the laminated nonwoven fabric of this invention prepares a staple fiber layer, a short fiber layer, and an elastomer nonwoven fabric separately, and integrates the multilayer laminated body which laminated | stacked them simply by hydroentanglement process and / or a needle punch. You may manufacture by the method.

  The laminated nonwoven fabric of the present invention has a three- or four-layer structure in which staple fiber layers are laminated on one side or both sides of a laminate of short fiber layer / elastomer nonwoven fabric, one side of a laminate of short fiber layer / elastomeric nonwoven fabric / short fiber layer, or It has a 4- or 5-layer structure in which staple fiber layers are laminated on both sides. Therefore, the staple fiber layer has a texture inherent to the staple fiber layer, the short fiber layer ensures the stability during production and processing, and the elastomer nonwoven fabric ensures the stretchability. Furthermore, it can be set as the structure which has a hydrophilic layer (or water absorption layer) inside by forming a short fiber layer with a hydrophilic fiber. Therefore, the laminated nonwoven fabric of the present invention can be used in any form of a dry state or a wet state. The elastic member of the absorbent article, the sanitary mask, the interpersonal and objective wiper, the poultice, the cosmetic article (for example, cleansing) Sheet and face mask), pads for gauze and adhesive bandages, automotive ceiling backings, chair backings, and other industrial material applications.

(Manufacture of laminated body A)
As the short fiber layer, a tissue (manufactured by Havicks Co., Ltd.) having a basis weight of 17 g / m ² made of pulp fiber was prepared. While this tissue is placed on a transport belt of a meltblown apparatus and continuously supplied, 60 mass of thermoplastic elastomer (styrene elastomer product name: Kraton 1657G, manufactured by Kraton Polymer Japan Co., Ltd.) is applied to the surface of the tissue. Resin and 40% by mass of a polypropylene resin are accumulated on a tissue so as to have a basis weight of 15 g / m ² by a melt blown method, and a laminate A composed of an elastomer nonwoven fabric and a short fiber layer is obtained. Obtained. This laminate A has a maximum stress of 10.0 N / 5 cm in the vertical direction, 4.2 N / 5 cm in the horizontal direction, and an elongation at which the maximum elongation stress is 12.2% in the vertical direction and 5.5 in the horizontal direction. 1%.

  The maximum stress of the laminate A and the elongation at which the extensional stress becomes the maximum are both constant speed tension type tensile tests according to JIS L 1096 6.12.1 A method (strip method) (2007). Using a machine, the sample piece was stretched under the conditions of a width of 5 cm, a grip interval of 10 cm, and a tensile speed of 10 ± 3 cm / min. Those of the laminate B were also measured by the same method. Further, the maximum stress and the elongation at which the elongation stress is maximized were obtained by stretching the laminate until the short fiber layer (tissue) was broken.

Accumulation of fibers by the melt blown method was performed according to the following conditions.
Polymer melting temperature (° C.) 290
Polymer discharge rate (g / min) 0.1
Hot air temperature (℃) 300
Hot air flow rate (m3 / min) 2.7
Hot air pressure (MPa) 0.47
Orifice hole diameter (mm) 0.3
Nozzle width (mm) 800
Nozzle pitch (mm) 1
Production speed (m / min) 10

(Manufacture of laminated body B)
As the short fiber layer, a tissue (manufactured by Havicks Co., Ltd.) having a basis weight of 17 g / m ² made of pulp fiber was prepared. While this tissue is placed on a transport belt of a meltblown apparatus and continuously supplied, 60% by mass of a thermoplastic elastomer (hydrogenated styrene-isoprene-styrene elastomer) and polypropylene resin 40 are formed on the surface of the tissue. A mixed resin mixed with mass% is accumulated on a tissue so as to have a basis weight of 13 g / m ² by a melt blown method, an elastomer nonwoven fabric (trade name: manufactured by Septon Kuraray Co., Ltd.), a short fiber layer, A laminate B consisting of This laminate B has a maximum stress of 9.8 N / 5 cm in the vertical direction, 4.0 N / 5 cm in the horizontal direction, and an elongation at which the maximum elongation stress is 11.8% in the vertical direction and 5.5 in the horizontal direction. 0%.

(Manufacture of elastomer nonwoven fabric)
The mixed resin used in the production of the laminate A was accumulated on the conveying belt by the melt blown method under the above conditions to obtain an elastomer nonwoven fabric having a basis weight of 15 g / m ² . The strain at 100% elongation in the longitudinal direction (MD direction) and the lateral direction (CD direction) of this elastomer nonwoven fabric (that is, corresponding to the elastomer nonwoven fabric constituting the laminate A) was 23%.

(Sample 1)
² parallel card webs of about 34 g / m ² per unit area made of a split composite fiber (trade name DFS (SH), manufactured by Daiwabo Polytech Co., Ltd.) made of a combination of polyethylene / polyethylene terephthalate and having a fineness of 2.2 dtex and a fiber length of 51 mm. Sheets were prepared and used as a first staple fiber web and a second staple fiber web, respectively.

  A laminate having a four-layer structure is formed by disposing a first staple fiber web at a position adjacent to the surface of the elastomer nonwoven fabric and a second staple fiber web at a position adjacent to the surface of the short fiber layer on both surfaces of the laminate A. Formed and subjected to hydroentanglement treatment. The hydroentanglement treatment uses a nozzle in which orifices having a hole diameter of 0.1 mm are provided at intervals of 0.6 mm, sprays a columnar water flow of 3 MPa once toward the surface of the first staple fiber web of the laminate, A columnar water flow having a water pressure of 3.5 MPa was jetted once toward the surface of the two staple fiber web. Next, the laminated body after the hydroentanglement treatment was dried at 110 ° C. using an air-through heat treatment machine to obtain a laminated nonwoven fabric.

(Sample 2)
As a split type composite fiber, ^{2 having} a basis weight of about 34 g / m ² made of a split type composite fiber (trade name DF-7 manufactured by Daiwabo Polytech Co., Ltd.) having a fineness of 2.2 dtex and a fiber length of 51 mm made of a combination of polyethylene / polypropylene. When the sample 1 is manufactured except that one parallel card web is used as the first staple fiber web and the second staple fiber web, respectively, and the water pressure shown in Table 1 is used during the hydroentanglement process. A laminated nonwoven fabric was obtained in accordance with the same procedure as that adopted in the above.

(Sample 3)
As the fibers constituting the staple fiber, fineness 1.7 dtex, viscose rayon fiber length 40mm Select (trade name Corona, Daiwabo rayon Co.), the two basis weight of about 34g / m ² composed of the rayon Adopted when producing Sample 1 except that the parallel card web was used as the first staple fiber web and the second staple fiber web, respectively, and the water pressure shown in Table 1 was used during the hydroentanglement process. A laminated nonwoven fabric was obtained according to the same procedure as described above.

(Sample 4)
Using the rayon fiber used for the production of Sample 3, a parallel card web having a basis weight of about 34 g / m ² was prepared, and this was used as the first staple fiber web. The polyethylene staple terephthalate fiber having a fineness of 1.6 dtex and a fiber length of 44 mm use (trade name 70 W, manufactured by Toyobo Co., Ltd.) having a basis weight of about 34g / m ² of a parallel card web of that used as the second staple fiber web, and the water pressure described in Table 1 during the hydroentanglement The laminated nonwoven fabric was obtained according to the procedure similar to the procedure employ | adopted when manufacturing the sample 1 except having been.

(Sample 5)
Two parallel card webs each having a basis weight of about 34 g / m ² made of acrylic fiber (trade name: Toleron, manufactured by Toray Industries, Inc.) having a fineness of 1.0 dtex and a fiber length of 38 mm, are respectively a first staple fiber web and a second staple fiber. A laminated nonwoven fabric was obtained according to the same procedure as that employed when producing Sample 1 except that it was used as a web and the water pressure shown in Table 1 was used during hydroentanglement treatment.

(Sample 6)
A parallel card web made of a combination of polyethylene / polyethylene terephthalate and having a fineness of 2.2 dtex and a split type composite fiber having a fiber length of 51 mm (trade name DFS (SH), manufactured by Daiwabo Polytech Co., Ltd.) and having a basis weight of about 42.5 g / m ^2. Were made into a first staple fiber web and a second staple fiber web, respectively.

  A first staple fiber web and a second staple fiber web were arranged on both sides of an elastomer nonwoven fabric (without a tissue layer) to form a laminate having a three-layer structure, and this was subjected to hydroentanglement treatment. The hydroentanglement treatment uses a nozzle in which orifices having a hole diameter of 0.1 mm are provided at intervals of 0.6 mm, sprays a columnar water flow of 3 MPa once toward the surface of the first staple fiber web of the laminate, A columnar water flow having a water pressure of 3.5 MPa was jetted once toward the surface of the two staple fiber web. Next, the laminate was dried at 110 ° C. using an air-through heat treatment machine to obtain a laminated nonwoven fabric.

(Sample 7)
As a split type composite fiber, a basis weight of about 42.5 g / m ² made of a split type composite fiber (trade name: DF-7, manufactured by Daiwabo Polytech Co., Ltd.) having a fineness of 2.2 dtex and a fiber length of 51 mm made of a combination of polyethylene / polypropylene. Sample 6 was manufactured except that the two parallel card webs were used as the first staple fiber web and the second staple fiber web, respectively, and the water pressure shown in Table 1 was used during the hydroentanglement process. A laminated nonwoven fabric was obtained according to the same procedure as that adopted.

(Sample 8)
As a fiber constituting the staple fiber, a viscose rayon (trade name Corona, manufactured by Daiwabo Rayon Co., Ltd.) having a fineness of 1.7 dtex and a fiber length of 40 mm is selected, and the basis weight of this rayon is about 42.5 g / m ² . A laminated nonwoven fabric was obtained according to the same procedure as that used when producing Sample 6, except that one parallel card web was used as the first staple fiber web and the second staple fiber web, respectively.

(Sample 9)
Using the rayon fibers used in the manufacture of Sample 8, a parallel card web having a basis weight of about 42.5 g / m ² was prepared, and this was used as the first staple fiber web. The polyethylene had a fineness of 1.6 dtex and a fiber length of 44 mm. A parallel card web having a basis weight of about 42.5 g / m ² made of terephthalate fiber (trade name 70W, manufactured by Toyobo Co., Ltd.) was used as the second staple fiber web, and listed in Table 1 during hydroentanglement treatment. A laminated nonwoven fabric was obtained in accordance with the same procedure as that adopted when the sample 6 was manufactured except that the water pressure was used.

(Sample 10)
Two parallel card webs each having a basis weight of about 42.5 g / m ² made of acrylic fiber (trade name: Toleron, manufactured by Toray Industries, Inc.) having a fineness of 1.0 dtex and a fiber length of 38 mm are respectively connected to the first staple fiber web and the second staple fiber web. A laminated nonwoven fabric was obtained according to the same procedure as that employed when producing Sample 1 except that it was used as a staple fiber web.

(Sample 11)
Two parallel card webs each having a basis weight of about 35 g / m ² made of cotton (including fibers having a fiber length of 10 to 60 mm, an average fiber length of 26 mm, trade name MS-D, manufactured by Marusan Sangyo Co., Ltd.) A staple fiber web and a second staple fiber web were produced. A laminate having a four-layer structure is formed by disposing a first staple fiber web at a position adjacent to the surface of the elastomer nonwoven fabric and a second staple fiber web at a position adjacent to the surface of the short fiber layer on both surfaces of the laminate B. Formed and subjected to hydroentanglement treatment. The hydroentanglement process was performed under the same conditions as those adopted when the sample 1 was manufactured. Furthermore, the laminated body after the hydroentanglement process was dried according to the procedure similar to the procedure employ | adopted when manufacturing the sample 1, and the laminated nonwoven fabric was obtained.

(Sample 12)
Viscose rayon with a fineness of 1.7 dtex and a fiber length of 40 mm (trade name Corona, manufactured by Daiwabo Rayon Co., Ltd.) and polyethylene terephthalate fiber with a fineness of 1.6 dtex and a fiber length of 44 mm (trade name of 70 W, manufactured by Toyobo Co., Ltd.) Were mixed at a ratio of 8: 2 (weight ratio). Two parallel card webs having a weight per unit area of about 35 g / m ^{2 made} of the mixed fibers were prepared as first and second staple fiber webs, respectively.

  A laminate having a four-layer structure is formed by disposing a first staple fiber web at a position adjacent to the surface of the elastomer nonwoven fabric and a second staple fiber web at a position adjacent to the surface of the short fiber layer on both surfaces of the laminate B. Formed and subjected to hydroentanglement treatment. In the hydroentanglement treatment, a columnar water flow of 2.5 MPa is sprayed once toward the surface of the first staple fiber web of the laminate using a nozzle in which orifices having a hole diameter of 0.1 mm are provided at intervals of 0.6 mm. A columnar water flow having a water pressure of 3.0 MPa was jetted once toward the surface of the second staple fiber web. Next, the laminated body after the hydroentanglement treatment was dried at 110 ° C. using an air-through heat treatment machine to obtain a laminated nonwoven fabric.

(Sample 13)
One parallel card web having a basis weight of about 35 g / m ² made of a split type composite fiber (trade name DFS (SH) manufactured by Daiwabo Polytech Co., Ltd.) having a fineness of 2.2 dtex and a fiber length of 51 mm was produced. This web was disposed at a position adjacent to the surface of the elastomer nonwoven fabric of the laminate B to form a laminate having a three-layer structure, and subjected to hydroentanglement treatment. Hydroentanglement treatment is performed by injecting a columnar water flow of 2.5 MPa once toward the surface of the fiber web of the laminated body using a nozzle in which orifices having a hole diameter of 0.1 mm are provided at intervals of 0.6 mm, and short fibers A columnar water flow having a water pressure of 3.0 MPa was jetted once toward the surface of the layer. Next, the laminated body after the hydroentanglement treatment was dried at 110 ° C. using an air-through heat treatment machine to obtain a laminated nonwoven fabric.

(Sample 14)
Two parallel card webs each having a basis weight of about 35 g / m ² made of a split type composite fiber having a fineness of 2.2 dtex and a fiber length of 38 mm (trade name DFS (SH) manufactured by Daiwabo Polytech Co., Ltd.) Made as a staple fiber web. A laminate having a four-layer structure in which the first staple fiber web is disposed at a position adjacent to the surface of the elastomer nonwoven fabric of the laminate B, and the second staple fiber web is disposed at a position adjacent to the surface of the short fiber layer. This was subjected to hydroentanglement treatment. In the hydroentanglement treatment, a columnar water flow of 3.0 MPa is sprayed once toward the surface of the first staple fiber web of the laminate using a nozzle in which orifices having a hole diameter of 0.1 mm are provided at intervals of 0.6 mm. A columnar water flow having a water pressure of 3.0 MPa was jetted once toward the surface of the second staple fiber web. Next, the laminated body after the hydroentanglement treatment was dried at 110 ° C. using an air-through heat treatment machine to obtain a laminated nonwoven fabric.

(Sample 15)
Two parallel card webs having a basis weight of about 35 g / m ² made of polyethylene terephthalate fibers (trade name: 70 W, manufactured by Toyobo Co., Ltd.) having a fineness of 1.6 dtex and a fiber length of 44 mm are respectively used as first and second staple fiber webs. As produced. A laminate having a four-layer structure is formed by disposing a first staple fiber web at a position adjacent to the surface of the elastomer nonwoven fabric and a second staple fiber web at a position adjacent to the surface of the short fiber layer on both surfaces of the laminate B. Formed and subjected to hydroentanglement treatment. In the hydroentanglement treatment, a columnar water stream of 3.0a is sprayed once toward the surface of the first staple fiber web of the laminate using a nozzle in which orifices having a hole diameter of 0.1 mm are provided at intervals of 0.6 mm. A columnar water flow having a water pressure of 3.5 MPa was jetted once toward the surface of the second staple fiber web. Next, the laminated body after the hydroentanglement treatment was dried at 110 ° C. using an air-through heat treatment machine to obtain a laminated nonwoven fabric.

(Sample 16)
Two parallel card webs having a weight per unit area of about 35 g / m ^{2 made} of the same cotton as that used in the preparation of Sample 11 were prepared as a first staple fiber web and a second staple fiber web, respectively. A tissue having a weight per unit area of 26 g / m ² (manufactured by Havix Co., Ltd.) was prepared, and the first and second staple fiber webs were respectively arranged so as to be adjacent to both surfaces thereof. This was subjected to hydroentanglement treatment. In the hydroentanglement treatment, a columnar water flow of 3.0 MPa is sprayed once toward the surface of the first staple fiber web of the laminate using a nozzle in which orifices having a hole diameter of 0.1 mm are provided at intervals of 0.6 mm. A columnar water flow having a water pressure of 3.0 MPa was jetted once toward the surface of the second staple fiber web. Next, the laminated body after the hydroentanglement treatment was dried at 110 ° C. using an air-through heat treatment machine to obtain a laminated nonwoven fabric.

(Sample 17)
In the hydroentanglement process, a columnar water flow having a water pressure of 2.5 MPa is sprayed once toward the surface of the first staple fiber web, and a columnar water flow having a water pressure of 3.0 MPa is once directed toward the surface of the second staple fiber web. A laminated nonwoven fabric was obtained using the same fiber and configuration as sample 11 except that the injection was carried out and following the same procedure employed when sample 11 was manufactured.

(Sample 18)
Two parallel card webs having a basis weight of about 30 / m ² made of a split type composite fiber (trade name DFS (SH), manufactured by Daiwabo Polytech Co., Ltd.) having a fineness of 2.2 dtex and a fiber length of 51 mm are respectively connected to the first and second parallel card webs. Made as a staple fiber web. As elastomeric nonwoven, consisting of amide elastomer, prepared spunbonded nonwoven fabric having a mass per unit area of 40 g / ^{m 2} (manufactured by part number PC5040 Idemitsu Unitech Co.), as a short fiber layer, having a basis weight of 17 g / ^{m 2} tissue (Habikkusu Co. Prepared).

  The first staple fiber layer / spunbond nonwoven fabric / tissue / second staple fiber layer were laminated in this order to form a four-layer laminate, which was subjected to hydroentanglement treatment. In the hydroentanglement treatment, a columnar water flow of 3.0 MPa is sprayed once toward the surface of the first staple fiber web of the laminate using a nozzle in which orifices having a hole diameter of 0.1 mm are provided at intervals of 0.6 mm. A columnar water flow having a water pressure of 3.5 MPa was jetted once toward the surface of the second staple fiber web. Next, the laminated body after the hydroentanglement treatment was dried at 110 ° C. using an air-through heat treatment machine to obtain a laminated nonwoven fabric.

(Sample 19)
A laminated nonwoven fabric was obtained according to the same procedure as that adopted when the sample 18 was manufactured, except that the water pressure during the hydroentanglement treatment was set to the values shown in Table 1.

According to JIS L 1096 6.12.1 A method (strip method), the obtained sample was measured using a constant-speed tension-type tensile tester with a sample piece width of 5 cm, a grip interval of 10 cm, and a tensile speed of 10 ± 3 cm. The sample was subjected to a tensile test under the conditions of 5 min / min, 5%, 10%, 15%, 20%, 25%, 30% elongation stress at the time of extension (elongation stress in the forward path) was measured, and immediately after 30% elongation, The elongation was relaxed at the same rate, and the elongation stress at 30%, 25%, 15%, and 10% elongation (elongation stress on the return path) was measured. The tensile test was carried out only in the transverse direction of the nonwoven fabric (direction perpendicular to the machine direction, that is, CD direction). Further, the length L ′ (cm) (three significant digits) of the grip interval when the elongation stress becomes 0 was measured, and strain (%) = {(L′−10.0) /3.0} From the x100 equation, the strain at 30% elongation was determined.
Table 1 shows the outward extension stress, the return extension stress, and the strain of each sample.

Samples 1 to 10, Samples 11 to 15, and Samples 16 to 19 all have a strain of not 0, and have a basis weight of about 100 g / m ² that does not have a laminate when repeatedly stretched by hand 2-3 times. Compared with the water entangled nonwoven fabric, the feeling of return could be felt more strongly. From this, it can be said that all the samples 1 to 10 had elasticity. Since the sample 16 did not contain an elastomer nonwoven fabric, the return stress at the time of elongation by 25% was small, and the stretchability was hardly exhibited.

  When the laminated nonwoven fabrics of Samples 1 to 5 and Samples 11 to 15 are manufactured, the winding speed of the laminate A is increased by 7% with respect to the feeding speed, and the tension (line tension) is increased in the machine direction (machine direction ( Even if the staple fiber layer is laminated and the hydroentanglement treatment is performed while adding to the MD direction)), the width is small and the width is about 5% (the horizontal dimension before applying the tension is 100). It is indicated by the rate of reduction of the dimension in the direction). When the same tension was applied to the elastomer nonwoven fabric in the longitudinal direction when the laminated nonwoven fabrics of Samples 6 to 10 were produced, a width of about 30% was generated, and it was difficult to continuously produce these samples. Since the sample 16 did not contain an elastomer nonwoven fabric, the width during production was small.

  Sample 1 and sample 6 differ only in the presence or absence of the short fiber layer, the fibers constituting the staple fiber layer are the same, and the overall basis weight is also substantially the same. The relationship between Sample 2 and Sample 7, Sample 3 and Sample 8, Sample 4 and Sample 9, and Sample 5 and Sample 10 is the same. However, the stress at the time of extension in the outward path was higher for the four-layer structure. This is considered to indicate that the short fibers of the short fiber layer and the staple fibers of the staple fiber layer are entangled well.

  As a result of examining the stretchability of the return path, it is found that the stress of the sample having the short fiber layer is equal to or smaller than the stress of the sample having no short fiber layer at the time of 20% elongation. all right. This is considered due to the fact that the short fiber layer broke when it was stretched by about 0 to 10% in the return path. This property is, for example, that when a part of the human body is covered with a laminated non-woven fabric, it is desirable to apply it while pulling in order to bring it into close contact with the human body. It can be used conveniently when the feeling of pressure that occurs when trying to return is not desired. Such applications include, for example, sanitary masks, face masks that cover part or all of the face, pads for gauze and bandages applied to wounds, and relatively small joints such as the back. It is used for industrial materials such as wrapping materials, automotive ceiling linings, and chair linings.

  Alternatively, from this table, in order to achieve the outward stress similar to the nonwoven fabric without the short fiber layer with the nonwoven fabric with the structure having the short fiber layer, the water pressure during the hydroentanglement treatment may be weakened. It is understood.

  Sample 17 is a sample that was produced with a water pressure lower than that used in sample 11. In this sample, although the stress at the time of 30% elongation in the forward path is smaller than that of the sample 11, the stress at 25% elongation in the return path is similar to that of the sample 11, and the stress at 20% elongation in the return path is greater than that of the sample 11. It was also expensive. This elongation characteristic indicates that the sample 17 has higher stretchability (property that can be easily extended and returned with a smaller force) than the sample 11.

  In addition, Sample 12 and Sample 17 exhibited higher stress at elongation than Sample 5 in which fibers were entangled with each other at a relatively high water pressure. This indicates that when the staple fiber layer is made of cellulosic fibers, the staple fibers can be entangled well with the fibers of the laminate to obtain a laminated nonwoven fabric having high mechanical properties.

  The laminated nonwoven fabric of the present invention has stretchability and is less likely to cause a reduction in dimension in the width direction during processing, and thus can be used in various applications. For example, a stretchable member (for example, a waist member) constituting an absorbent article ), Sanitary masks, wipers, cosmetic articles (for example, cleansing sheets, face masks), gauze, adhesive plaster pads, padding materials, automotive ceiling backing materials, chair backing materials, etc. Is suitable.

Claims (15)

A laminate in which a short fiber layer composed of short fibers having a fiber length of 0.5 to 20 mm is laminated on at least one surface of a stretchable nonwoven fabric containing fibers comprising a thermoplastic elastomer, and at least one of the laminates A staple fiber layer comprising staple fibers laminated on the surface of the fiber, wherein the fiber length is longer than the fiber length of the fibers contained in the short fiber layer,
The staple fiber layer and the laminate are integrated by interlacing fibers, short fibers, and staple fibers comprising a thermoplastic elastomer.
Laminated nonwoven fabric.   The laminated nonwoven fabric according to claim 1, wherein the stretchable nonwoven fabric is a meltblown nonwoven fabric.   The laminated nonwoven fabric according to claim 1 or 2, wherein the short fiber layer is a nonwoven fabric containing 50% by mass or more of hydrophilic fibers.   The laminated nonwoven fabric according to claim 3, wherein the short fiber layer is a wet papermaking nonwoven fabric made of pulp fibers.   The laminated nonwoven fabric according to any one of claims 1 to 4, wherein the staple fiber layer includes ultrafine fibers having a fineness of 1 dtex or less.   The laminated nonwoven fabric according to claim 5, wherein the ultrafine fibers are formed by splitting split-type composite fibers.   The laminated nonwoven fabric according to any one of claims 1 to 4, wherein the staple fiber layer includes cellulosic fibers.   The laminated nonwoven fabric according to claim 7, wherein the cellulosic fiber is cotton.   The laminated nonwoven fabric according to any one of claims 1 to 8, wherein the fibers comprising the thermoplastic elastomer, the short fibers, and the staple fibers are entangled with each other by a hydroentanglement process. A nonwoven fabric is formed by accumulating fibers containing a thermoplastic elastomer on one surface of a short fiber layer made of fibers having a fiber length of 0.5 to 20 mm, and an accumulated molten or softened thermoplastic elastomer A short fiber layer and a non-woven fabric including a fiber including a thermoplastic elastomer are bonded to each other by a fiber including the laminate to obtain a laminate;
A staple fiber layer containing staple fibers having a fiber length longer than the fiber length of the fibers contained in the short fiber layer is laminated on at least one surface of the laminate to obtain a multilayer laminate, and water flow in the multilayer laminate The manufacturing method of a laminated nonwoven fabric including giving a confounding process.   The method for producing a laminated nonwoven fabric according to claim 10, wherein fibers comprising the thermoplastic elastomer are accumulated by a melt blown method.   The method for producing a laminated nonwoven fabric according to claim 10 or 11, wherein the short fiber layer is a wet nonwoven fabric made of pulp fibers.   The manufacturing method of the laminated nonwoven fabric of any one of Claims 10-12 in which the said staple fiber layer contains 50 mass% or more of split type composite fibers.   The manufacturing method of the laminated nonwoven fabric of any one of Claims 10-12 in which the said staple fiber layer contains a cellulosic fiber.   The method for producing a laminated nonwoven fabric according to claim 14, wherein the cellulosic fiber is cotton.