JP2019183293A - Laminated nonwoven fabric - Google Patents

Abstract

To provide a laminated nonwoven fabric excellent in bulkiness and processability.SOLUTION: A laminated nonwoven fabric includes at least a two-layer laminate of a heat-fusible nonwoven fabric layer (A) and a spun-bonded nonwoven fabric layer (B). At least a composite fiber (Fa1) made of thermoplastic resin having two or more components is used as a fiber (Fa) which composes the heat-fusible nonwoven fabric layer (A). A fiber (Fb) which composes the spun-bonded nonwoven fabric layer (B) is made of polyolefin resin (Pb), having an average single fiber diameter of 6.5 μm or more and 11.9 μm or less. Also, the laminated nonwoven fabric has a specific volume of 10 cm/g or more.SELECTED DRAWING: None

Description

  The present invention relates to a laminated nonwoven fabric having excellent flexibility and good processability.

  In sanitary materials such as disposable diapers and sanitary napkins, a portion called a top sheet is generally provided on the skin contact surface side of the absorber, and a back sheet is provided on the non-contact surface side of the back surface. A three-dimensional gather for preventing leakage is provided, and a non-woven fabric is used according to the respective characteristics.

  First of all, the top sheet, which is required to be in direct contact with the skin and maintain comfort while being worn, quickly sends bodily fluids to the absorbent body, and the top sheet itself is hard to get wet and keeps it dry and does not wet the skin. Required. For this purpose, for example, a short fiber represented by a composite fiber composed of polyethylene terephthalate (PET) and polyethylene (PE) is formed into a sheet by carding and then self-fused by hot air treatment, and then a heat-fusible nonwoven fabric. A so-called air-through nonwoven fabric is preferably used.

  On the other hand, three-dimensional gathers and backsheets are required to have good surface feel and strength as well as high water resistance that does not leak the body fluid of the absorber to the outside. Conventionally, a laminated nonwoven fabric (hereinafter sometimes referred to as an SMS nonwoven fabric) in which a polypropylene spunbond nonwoven fabric and a polypropylene melt blown nonwoven fabric are laminated is often used.

  For example, a water-resistant SMS nonwoven fabric excellent in water resistance and having a good surface touch has been proposed (see Patent Document 1). Separately, there has been proposed an SMS nonwoven fabric having excellent water resistance and good surface feel using fibers made of a propylene / ethylene random copolymer having an ethylene component content of 0.5 to 10 mol% for the spunbond nonwoven fabric. (See Patent Document 2).

JP 2004-3096 A JP 2000-328420 A

  The SMS nonwoven fabric disclosed in Patent Documents 1 and 2 can obtain a nonwoven fabric having a smooth touch and good workability, but is flexible (cushioning property) to be deformed and recovered following the body elongation. Was also not enough.

  On the other hand, in order to give the heat-fusible nonwoven fabric used for the top sheet an appropriate elongation, an attempt was made to laminate a nonwoven fabric layer formed by the spunbond method, etc. When the non-woven fabric formed in (1) was heat-integrated, the fibers constituting the heat-fusible non-woven fabric were fused, making it impossible to obtain a laminated non-woven fabric having a texture unique to the heat-fusible non-woven fabric.

  Then, an object of this invention is to provide the laminated nonwoven fabric which has favorable workability, and is delicate and soft, and the touch which adapts to skin.

  As a result of repeated studies by the present inventors to achieve the above object, by setting the average single fiber diameter of the fibers constituting the spunbond nonwoven fabric layer within a specific range, a heat-fusible nonwoven fabric layer, It has been found that even when the spunbond nonwoven fabric layer is integrated, it is possible to obtain a laminated nonwoven fabric having not only moderate elongation and surface feel but also excellent strength.

That is, the present invention is intended to solve the above-mentioned problem, and the laminated nonwoven fabric of the present invention is formed by laminating a heat-fusible nonwoven fabric layer (A) and a spunbond nonwoven fabric layer (B), A fiber constituting the spunbond nonwoven fabric layer (B) using at least a composite fiber (Fa1) made of a thermoplastic resin having two or more components as the fibers (Fa) constituting the heat-fusible nonwoven fabric layer (A). (Fb) is made of polyolefin resin (Pb), the average single fiber diameter is 6.5 μm or more and 11.9 μm or less, and the specific volume of the laminated nonwoven fabric is 10 cm ³ / g or more. It is a laminated nonwoven fabric.

  According to the preferable aspect of the laminated nonwoven fabric of this invention, the average single fiber diameter of the said fiber (Fa) is 7 micrometers or more and 24 micrometers or less.

  According to the preferable aspect of the laminated nonwoven fabric of the present invention, the proportion of the heat-fusible nonwoven fabric layer (A) in the thickness direction is 40% or more and 98% or less.

  According to the preferable aspect of the laminated nonwoven fabric of this invention, MFR of the component which comprises the said spunbonded nonwoven fabric layer (B) is 80 g / 10min or more and 850 g / 10min or less.

According to the preferable aspect of the laminated nonwoven fabric of the present invention, the tensile strength in the longitudinal direction per unit weight of the laminated nonwoven fabric is 1.8 (N / 5 cm) / (g / m ² ) or more and 3.5 (N / 5 cm) / (g / m ² ) or less.

  According to the preferable aspect of the laminated nonwoven fabric of this invention, in addition to the said composite fiber (Fa1), the fiber (Fa) which comprises the said heat-fusible nonwoven fabric layer (A) is further 1 or more types of fibers ( Fa2).

  ADVANTAGE OF THE INVENTION According to this invention, the laminated nonwoven fabric which has moderate elongation, and is excellent in the delicate and excellent surface touch, especially the softness | flexibility (cushion property), ie, the touch which adapts to skin, and is excellent in intensity | strength can be obtained.

The laminated nonwoven fabric of the present invention is a laminated nonwoven fabric in which a heat-fusible nonwoven fabric layer (A) and a spunbond nonwoven fabric layer (B) are laminated, and the fibers constituting the heat-fusible nonwoven fabric layer (A) As (Fa), at least a composite fiber (Fa1) made of a thermoplastic resin having two or more components is used, and the fiber (Fb) constituting the spunbonded nonwoven fabric layer (B) is made of a polyolefin resin (Pb). Thus, the laminated nonwoven fabric has an average single fiber diameter of 6.5 μm or more and 11.9 μm or less, and the laminated nonwoven fabric has a specific volume of 10 cm ³ / g or more.

Although the component is demonstrated in detail below, this invention is not limited to the range demonstrated below unless the summary is exceeded.
[fiber]
The laminated nonwoven fabric of the present invention takes a suitable fiber form in accordance with the required properties of each nonwoven fabric layer.
(Fibers (Fa1) and (Fa2) constituting the heat-fusible nonwoven fabric layer (A))
The heat-fusible nonwoven fabric layer (A) of the present invention comprises at least a composite fiber (Fa1) made of a thermoplastic resin having two or more components as the fiber (Fa) constituting the layer. More preferably, it further contains one or more kinds of fibers (Fa2). Each will be described in detail below.

  First, for the composite fiber (Fa1) made of a thermoplastic resin having two or more components, a composite fiber composed of two component raw materials having different melting points is particularly preferably used from the viewpoint of thermal adhesiveness. Further, it preferably contains a high melting point component resin (Pa1) and a low melting point component resin (Pa2), and the difference in melting point between the high melting point component resin (Pa1) and the low melting point component resin (Pa2) is 10 ° C. or more. It is more preferable that However, it is preferable that the difference in the melting points is within 150 ° C. from the viewpoint of handling properties when processed into a nonwoven fabric and processability to sanitary materials.

  Examples of the high melting point component resin (Pa1) include polyester, polyamide, and polyolefin. Specific examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, and polytrimethylene terephthalate. Specific examples of the polyamide include polyamide 6, polyamide 66, polyamide 12, and the like. Examples of polyolefins include polyethylene, polypropylene, and propylene / ethylene copolymers. Among these, polyamide 6, polybutylene terephthalate and polypropylene are preferably used from the viewpoint of flexibility, and polyethylene terephthalate is preferably used from the viewpoint of cost.

  In addition, other components may be copolymerized in the high melting point resin (Pa1), and it is allowed to contain additives such as particles, flame retardants, and antistatic agents.

  Examples of the copolymer component include sodium 5-sulfoisophthalate and 3-hydroxybutanoic acid, and examples of the particles include titanium oxide. Examples of the flame retardant include an organic flame retardant and an inorganic flame retardant, and examples of the antistatic agent include an alcohol-based antistatic agent.

  And as said low melting-point component resin (Pa2), polyethylene and a polypropylene can be used, and especially polyethylene is preferably used from an adhesive viewpoint. Polyethylene is classified according to the production method and physical properties, and includes high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and the like, each of which has been studied for fibers. In the present invention, any polyethylene is used, but from the viewpoint of spinning stability, LLDPE is a preferred embodiment.

  The polyethylene used as the low-melting-point component resin (Pa2) is allowed to be blended with a small amount of other component polymers. Examples of other component polymers include polyolefin polymers such as polypropylene and poly (4-methyl-1-pentene) having a melting point close to that of polyethylene, and low melting point polyesters and low melting point polyamides. Moreover, in order to fully express the characteristics of polyethylene, the mass ratio of the blend is preferably 5% by mass or less, more preferably 2% by mass or less.

  The polyethylene has a melt flow rate (hereinafter sometimes referred to as MFR) of preferably 10 g / 10 min or more and 100 g / 10 min or less, more preferably 20 g / 10 min or more and 40 g / 10 min or less. is there. The melt flow rate here refers to a value measured at a temperature of 190 ° C. and a load of 2.16 kg in accordance with ASTM D1238 (Method A).

  Furthermore, the high melting point component resin (Pa1) and the low melting point component resin (Pa2) used in the present invention are generally used as antioxidants, weathering stabilizers, and the like, as long as the effects of the present invention are not impaired. Light stabilizers, antistatic agents, antifogging agents, antiblocking agents, lubricants such as polyethylene wax, nucleating agents, additives such as pigments, or other polymers can be added as necessary.

  As described above, the cross section of the composite fiber (Fa1) of the present invention needs to be composed of two components having different melting points, and the mass ratio (Pa1 / Pa2) is 90/10 to 10/90. Is preferable, 70/30 to 30/70 is more preferable, and 60/40 to 40/60 is a more preferable aspect. By setting the mass ratio of the high melting point component resin (Pa1) to preferably 10% by mass or more, more preferably 30% by mass or more, and further preferably 40% by mass or more, sufficient physical properties can be imparted to the nonwoven fabric. . Moreover, sufficient thermal adhesiveness is obtained by setting the mass ratio of the low melting point component resin (Pa2) to preferably 10% by mass or more, more preferably 30% by mass or more, and further preferably 40% by mass or more.

  In the cross-sectional shape of the composite fiber (Fa1) of the present invention, it is preferable that the low melting point component forms at least a part of the fiber surface. Examples of the cross-sectional shape may be a concentric core-sheath structure, an eccentric core-sheath structure, and a side-by-side structure.

The average single fiber diameter of the composite fiber (Fa1) of the present invention is preferably 7 μm or more and 24 μm or less, more preferably 8 μm or more as a lower limit, further preferably 10 μm or more, and more preferably 21 μm or less as an upper limit. More preferably, it is 20 μm or less. The average single fiber diameter of the composite fiber (Fa1) is preferably not less than the lower limit from the viewpoint of spinning stability, and the thinner the average single fiber diameter, the more the bonding points of the fibers as a non-woven fabric. Property is improved. Moreover, when using for a sanitary material, it is a preferable aspect that an average single fiber diameter is below an upper limit from a rigid viewpoint.

  Next, regarding the fiber (Fa2), as described above, the fiber constituting the heat-fusible nonwoven fabric layer (A) of the present invention is one or more kinds of fibers (Fa2) in addition to the composite fiber (Fa1). More preferably, it contains By being configured in this way, the bulkiness and the flexibility to deform and recover following the body elongation can be further improved, and can be applied to sanitary materials such as paper diapers, It can be set as a laminated nonwoven fabric which is delicate and soft and has a touch that fits the skin.

  Examples of the fibers (Fa2) include natural fibers such as cotton, silk and wool, viscose rayon, cupra, and solvent-spun cellulose fibers (for example, “Riocel” (registered trademark) and “Tencel” (registered trademark)). ), Etc., polyolefin fibers, polyester fibers and polyamide fibers, (poly) acrylic single fibers made of acrylonitrile, fibers made of engineering plastics such as polycarbonate, polyacetal, polystyrene, cyclic polyolefin, etc. It may be.

  Further, as the fiber (Fa2), not only a single fiber made of one kind of thermoplastic resin, but also a composite fiber other than a split type composite fiber made of two or more kinds of thermoplastic resins (for example, concentric or eccentric) More preferably, a core-sheath composite fiber, a sea-island composite fiber, or a side-by-side composite fiber) is used.

This fiber (Fa2) may be a heat-adhesive fiber in which a thermoplastic resin having a melting point equal to or lower than that of one constituent component is exposed on the fiber surface. In that case, when the bonded portion by one component of the fiber (Fa2) is formed by heating (that is, the thermal bonded portion by one component of the fiber is formed), this fiber (Fa2) is 1 of the composite fiber (Fa1). A heat-bonding part can be formed in a nonwoven fabric with a component.
(Fibers constituting the spunbond nonwoven fabric layer (B) (Fb))
The fiber (Fb) which comprises the spunbond nonwoven fabric layer (B) used by this invention consists of polyolefin resin (Pb). Examples of the polyolefin resin (Pb) include polypropylene resin and polyethylene resin. Examples of polypropylene resins include propylene homopolymers or copolymers of propylene and various α-olefins. Polyethylene resins include ethylene homopolymers or copolymers of ethylene and various α-olefins. Polymers and the like can be mentioned, and polypropylene resins are particularly preferably used from the viewpoint of spinnability and strength characteristics.

  As polyolefin resin (Pb) of this invention, 2 or more types of mixtures may be sufficient, and the resin composition containing other polyolefin resin, thermoplastic elastomer, etc. can also be used. Naturally, two or more types of thermoplastic resins having different MFRs can be blended at an arbitrary ratio to adjust the MFR.

  Further, the antioxidant, weathering stabilizer, light stabilizer, antistatic agent, antifogging agent, antiblocking agent usually used for the polyolefin resin (Pb) of the present invention are within the range not impairing the effects of the present invention. Additives such as lubricants, nucleating agents, and pigments, or other polymers can be added as necessary.

  For the polyolefin resin (Pb) of the present invention, the value measured by ASTM D1238 (Method A) is adopted as the MFR.

  Note that, according to this standard, for example, polypropylene is measured at a load of 2.16 kg and a temperature of 230 ° C., and polyethylene is measured at a load of 2.16 kg and a temperature of 190 ° C.

  The MFR of the polyolefin resin (Pb) is preferably 75 g / 10 min or more and 850 g / 10 min or less. The lower limit of MFR is preferably 75 g / 10 min or more, more preferably 120 g / 10 min or more, still more preferably 155 g / 10 min or more, and the upper limit is preferably 850 g / 10 min or less, more preferably It is 600 g / 10 min or less, more preferably 400 g / 10 min or less. Even if it is stretched at a high spinning speed in order to stabilize the thinning behavior of the fiber when spinning the fiber (Fb) constituting the spunbond nonwoven fabric layer (B) and to increase the productivity by setting the lower limit or more. , Stable spinning becomes possible. Further, by stabilizing the thinning behavior, the yarn swaying is suppressed, and unevenness when collecting in a sheet form is less likely to occur. Moreover, since it becomes possible to extend | stretch stably at a high spinning speed by setting it as below an upper limit, the orientation crystallization of a fiber can be advanced and it can be set as the fiber which has high mechanical strength.

  The melting point of the polyolefin resin (Pb) of the present invention is preferably 80 ° C. or higher and 200 ° C. or lower, more preferably 100 ° C. or higher and 180 ° C. or lower. When the melting point is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, heat resistance that can withstand practical use is easily obtained. Further, by setting the melting point to preferably 200 ° C. or less, more preferably 180 ° C. or less, it becomes easy to cool the yarn discharged from the die, and it becomes easy to perform stable spinning by suppressing the fusion of fibers.

  Further, it is important that the fibers (Pb) constituting the spunbond nonwoven fabric layer (B) used in the present invention have an average single fiber diameter of 6.5 to 11.9 μm. The average single fiber diameter is preferably 6.5 μm or more, more preferably 7.5 μm or more, and even more preferably 8.4 μm or more, thereby preventing a decrease in spinnability and producing a stable and high-quality nonwoven fabric. can do. On the other hand, when the average single fiber diameter is preferably 11.9 μm or less, more preferably 11.2 μm or less, and even more preferably 10.6 μm or less, the denseness and uniformity are high. Even if the content ratio of B) is lowered, it has excellent water resistance characteristics that can withstand practical use, and furthermore, the conditions at the time of lamination with the heat-fusible nonwoven fabric layer (A) can be moderated. The nonwoven fabric layer (A) can be laminated while maintaining the bulkiness.

Moreover, a composite type fiber can also be used for the fiber (Pb) which comprises the spun bond nonwoven fabric layer (B) of this invention. Examples of the composite form of the composite fiber include composite forms such as a concentric core-sheath type, an eccentric core-sheath type, and a sea-island type. Especially, since it is excellent in spinnability and a fiber can be adhere | attached uniformly by thermal bonding by arrange | positioning a low melting-point component to a sheath component, it is a preferable aspect to set it as a concentric core sheath type composite form.
[Laminated nonwoven fabric]
As described above, the laminated nonwoven fabric of the present invention is a laminated nonwoven fabric in which the heat-fusible nonwoven fabric layer (A) and the spunbond nonwoven fabric layer (B) are laminated. By comprising in this way, the laminated nonwoven fabric which was able to obtain the outstanding surface touch feeling (especially softness | flexibility (cushion property)) and also the characteristic of the outstanding intensity | strength can be obtained.

  The laminated nonwoven fabric of the present invention may be laminated so that the uppermost layer is a thermoplastic nonwoven fabric layer (A) and the lowermost layer is a spunbond nonwoven fabric layer (B). A nonwoven fabric layer (B) can also be inserted. For example, the aspect which becomes (A) (B) (B) from each upper layer, the aspect which becomes (A) (B) (B) (B), etc. are mentioned.

  Here, the softness | flexibility in this invention is the characteristic (cushion property) which deform | transforms and recovers following body elongation, and can be excellent in the touch which adapts to skin by being excellent in this.

By the way, when a human touches the surface of an object with his / her finger, does the object have a tactile sensation or rebound depending on the relationship between the pressure of the finger and the condition of the sinking of the surface of the object? It is said to perceive. That is, when an object having a certain specific volume is touched, the surface sinks with a small pressure, so that the object follows the shape of the finger and deforms, so that it is possible to obtain a feeling that fits the skin. In general, the area of the finger used when a person touches a soft object is approximately 200 mm ² , and the force for pressing the nonwoven fabric with the person's finger is said to be approximately 40 g. From this, it is considered that the thickness of the laminated nonwoven fabric when a load of this pressure (= 2.0 kPa) is applied reproduces the case where the nonwoven fabric is touched with a human finger. Therefore, in the present invention, when the nonwoven fabric is compressed until the thickness of the nonwoven fabric is at least 60% or less of the original thickness when this pressure is applied, a feeling that fits the skin is obtained. That is, it is said that there is flexibility. In addition, the laminated nonwoven fabric whose thickness of the nonwoven fabric when the pressure is applied is 50% or less with respect to the original thickness is more preferable as being flexible, and further preferably 45% or less.

In the present invention, the thickness (mm) of the laminated nonwoven fabric is measured on the basis of JIS L 1913 (2010 edition), and a presser foot having an area of 200 mm ² is prepared. Is a mean value of three test pieces randomly collected by measuring the thickness after applying a pressure of 0.2 kPa for a certain period of time.

  The laminated nonwoven fabric of the present invention preferably has a thickness of 0.1 mm to 3 mm. When the thickness is preferably 0.2 to 2 mm, more preferably 0.3 to 1.5 mm, the laminated nonwoven fabric does not become too hard, and when used for sanitary materials such as paper diapers, it should have an appropriate texture. Can do.

  As described above, in order to obtain the property that the laminated nonwoven fabric of the present invention deforms and recovers following the body elongation, the proportion of the heat-fusible nonwoven fabric layer (A) in the thickness direction of the laminated nonwoven fabric is 40% or more. It is preferably 98% or less. By setting the lower limit to preferably 40% or more, more preferably 45% or more, and further preferably 50% or more, it becomes easy to obtain a feeling that fits the skin when touched with a finger. On the other hand, if the upper limit is preferably 98% or less, and more preferably 95% or less, the rigidity can be maintained and the workability is excellent.

  In the present invention, the proportion of the heat-fusible nonwoven fabric layer (A) in the thickness direction of the laminated nonwoven fabric is observed by observing the cross section of the laminated nonwoven fabric 50 to 200 times using a scanning electron microscope (SEM). The cross-sectional thickness of the nonwoven fabric and the cross-sectional thickness of the heat-fusible nonwoven fabric are measured, and the value obtained by calculating the ratio of the heat-fusible nonwoven fabric in the thickness direction of the laminated nonwoven fabric is indicated.

It is important that the specific volume of the laminated nonwoven fabric of the present invention is 10 cm ³ / g or more. Here, the specific volume indicates the volume per unit mass of the nonwoven fabric, and it can be determined that the higher this value, the better the bulkiness of the nonwoven fabric. The specific volume of the laminated nonwoven fabric can be calculated by dividing the thickness by the basis weight. The higher the specific volume of the nonwoven fabric and the higher the bulkiness, the more preferable cushioning properties can be imparted when used for sanitary materials such as disposable diapers. The specific volume is more preferably 15 cm ³ / g or more, and still more preferably 20 cm ³ / g or more. In view of the use as a nonwoven fabric for sanitary materials, the upper limit is preferably 100 cm ³ / g or less.

From the same viewpoint, the apparent density of the nonwoven fabric of the present invention is a preferred embodiment that is 0.10 g / cm ³ or less. The apparent density can be calculated by dividing the basis weight by the thickness. Apparent density is more preferably 0.07 g / cm ³ or less, further preferably 0.05 g / cm ³ or less. By setting the apparent density within the above range, sufficient bulkiness can be obtained when used as a nonwoven fabric. The apparent density is preferably 0.01 g / cm ³ or more in view of the use as a non-woven fabric for sanitary materials.

The basis weight (g / m ² ) of the laminated nonwoven fabric is measured based on 6.2 “mass per unit area” of JIS L 1913 (2010 edition), and the size of the test piece is 5 cm. randomly three collected as × 5 cm, weighed respective mass in a standard state (g), and a representation of the average value at 1 m ² per mass (g / m ^2).

In the laminated nonwoven fabric of the present invention, the basis weight is preferably 3 g / m ² or more and 200 g / m ² or less. The basis weight is more preferably 5 g / m ² or more and 150 g / m ² or less, and further preferably 10 g / m ² or more and 100 g / m ² or less. By setting the basis weight within the above range, sufficient flexibility can be imparted to the laminated nonwoven fabric.

  In the laminated nonwoven fabric of the present invention, the MFR of the laminated nonwoven fabric measured in a state where the heat-fusible nonwoven fabric layer (A) is removed is preferably 80 g / 10 minutes or more and 850 g / 10 minutes or less. By setting it to the lower limit or higher, it becomes possible to stably draw at a high spinning speed, so that the fibers can be oriented and crystallized to obtain fibers having high mechanical strength. On the other hand, the upper limit is preferably 850 g / 10 min or less, more preferably 600 g / 10 min or less, and even more preferably 400 g / 10 min or less, whereby the thinning behavior when the fiber is stretched is obtained. Stable spinning is possible even if the spinning is performed at a high spinning speed in order to stabilize and increase the productivity. Further, by stabilizing the thinning behavior, the yarn swaying is suppressed, and unevenness when collecting in a sheet form is less likely to occur.

  In the present invention, this MFR adopts a value measured by ASTM D1238 (Method A), and the measurement is performed by peeling the heat-fusible non-woven fabric layer (A) from the laminated non-woven fabric, and the fibers derived from this non-woven fabric layer. If there is residual yarn, remove it with tweezers, and check the absence of residual yarn by visual confirmation using a magnifying glass such as a linen tester. .

The laminated nonwoven fabric of the present invention preferably has a longitudinal tensile strength per unit basis weight of 1.8 (N / 5 cm) / (g / m ² ) or more. The longitudinal tensile strength per unit basis weight is 1.8 (N / 5 cm) / (g / m ² ) or more, preferably 1.9 (N / 5 cm) / (g / m ² ) or more, more preferably By setting it as 2.0 (N / 5cm) / (g / m < ² >) or more, it can be set as the thing excellent in workability without fracture | rupture at the time of a process. The longitudinal tensile strength per unit weight is the spinning speed and average single fiber diameter of the fibers constituting the spunbond nonwoven fabric layer, the mass ratio of the laminated nonwoven fabric, and the thermocompression bonding conditions of the laminated nonwoven fabric (compression rate, temperature and linear pressure). It can be adjusted by. Further, the tensile elongation is preferably 15% or more, more preferably 20% or more, and even more preferably 30% or more, so that processing without breakage is possible at the time of molding or the like. It can be made excellent in workability.

In the present invention, the tensile strength and the tensile elongation in the longitudinal direction per unit basis weight shall adopt the values measured as follows in accordance with 6.3.1 of JIS L1913 (2010).
(1) Three test pieces having a width of 5 cm × 30 cm are collected from the laminated nonwoven fabric.
(2) A test piece is set on a tensile tester with a gripping interval of 20 cm.
(3) A tensile test is performed at a tensile speed of 10 cm / min. The strength when the sample breaks is defined as tensile strength (N / 5 cm), and the elongation when fractured is defined as tensile elongation (%). The average value is calculated.
(4) Divide the calculated tensile strength (N / 5 cm) by the basis weight (g / m ² ) and round off to the second decimal place.
[Method for producing laminated nonwoven fabric]
Next, an example of a method for producing the laminated nonwoven fabric of the present invention will be described.

The laminated nonwoven fabric of the present invention is produced by forming a heat-fusible nonwoven fabric layer (A) and a spunbond nonwoven fabric layer (B) and laminating them.
(Formation of heat-fusible nonwoven fabric layer (A))
As a method of forming the heat-fusible nonwoven fabric layer (A) in the present invention, a method of forming a long-fiber nonwoven fabric layer containing a composite fiber composed of two or more thermoplastic resins by a spunbond method or a melt blow method, A method of forming an air-through nonwoven fabric layer by applying a hot air treatment after forming a fiber web with a card (air-through method) or the like can be employed. Among them, the air-through method can be preferably applied because a product with good bulkiness is obtained.

  The air-through method is a manufacturing method in which short fibers, which are raw cotton, are passed through a card machine, the short fibers are opened, formed into a fiber web, and then made into a nonwoven fabric by heat treatment.

  As for the heat treatment method, for example, heat bonding by hot air treatment or fusion by ultrasonic waves, a heat embossing roll in which engravings (uneven portions) are respectively formed on a pair of upper and lower roll surfaces, and one roll surface is flat (smooth) ) Roll and a heat embossing roll consisting of a combination of the surface of the other roll with a sculpture (uneven portion) and a thermocalendering roll consisting of a combination of a pair of upper and lower flat (smooth) rolls. In addition, each combination can be applied.

Especially, since the heat bond by a hot air process can hold | maintain the thickness of a nonwoven fabric, ie, bulkiness, it is used especially preferable.
(Formation of spunbond nonwoven fabric layer (B))
In the method of forming the spunbond nonwoven fabric layer (B) in the present invention, first, a molten thermoplastic resin is spun out as a long fiber from a spinneret, and this is sucked and stretched with compressed air by an ejector, and then on a moving net. The fibers are collected to form a nonwoven fiber web.

  As the shape of the spinneret and the ejector, various shapes such as a round shape and a rectangular shape can be adopted. In particular, the combination of a rectangular base and a rectangular ejector is used because the amount of compressed air used is relatively small, the energy cost is excellent, the yarns are not easily fused or scratched, and the yarn is easy to open. Preferably used.

  In the present invention, a thermoplastic resin is melted in an extruder, weighed and supplied to a spinneret, and is spun as a long fiber. When a polyolefin resin is used as the thermoplastic resin, the spinning temperature when melting and spinning the polyolefin resin is preferably 200 ° C. or higher and 270 ° C. or lower, more preferably 210 ° C. or higher and 260 ° C. or lower, Preferably they are 220 degreeC or more and 250 degrees C or less. By setting the spinning temperature within the above range, a stable molten state can be obtained, and excellent spinning stability can be obtained.

  The spun long fiber yarn is then cooled. As a method for cooling the spun yarn, for example, a method for forcibly blowing cold air onto the yarn, a method for natural cooling at the ambient temperature around the yarn, and a method for adjusting the distance between the spinneret and the ejector Or a combination of these methods can be employed. The cooling conditions can be appropriately adjusted and adopted in consideration of the discharge amount per single hole of the spinneret, the spinning temperature, the atmospheric temperature, and the like.

  Next, the cooled and solidified yarn is pulled and compressed by compressed air injected from the ejector. The spinning speed is preferably 3000 m / min or more and 6500 m / min or less, more preferably 3500 m / min or more and 6500 m / min or less, and further preferably 4000 m / min or more and 6500 m / min or less. By setting the spinning speed to 3000 m / min or more and 6500 m / min or less, high productivity can be obtained, and oriented crystallization of the fibers proceeds, and high-strength long fibers can be obtained. Normally, if the spinning speed is increased, the spinnability deteriorates and the yarn cannot be stably produced. As described above, the intended fiber can be obtained by using a thermoplastic resin having a specific range of MFR. In addition to being able to spin stably, the fiber diameter is in a specific range, so that the conditions during laminating described later can be moderated, so that the bulkiness of the heat-fusible nonwoven fabric is maintained. Can be laminated.

Subsequently, the obtained long fibers are collected on a moving net to form a nonwoven fiber web. In the present invention, it is also a preferable aspect that a non-woven fiber web is temporarily bonded by contacting a heat flat roll from one side of the net on the net. By doing in this way, it prevents the surface layer of the nonwoven fiber web from turning over or blowing while it is being transported on the net, and transporting from collecting the yarn to thermocompression bonding. Can improve sex.
(Lamination of non-woven fabric layer)
The method for producing the laminated nonwoven fabric of the present invention can be any method as long as the heat-fusible nonwoven fabric layer (A) and the spunbond nonwoven fabric layer (B) can be laminated. It can be carried out. For example, a method of depositing a fiber web in which short fibers are formed by a card machine directly on a spunbond nonwoven fabric and fusing it by heat treatment to form a heat-fusible nonwoven fabric, a spunbond nonwoven fabric layer, and a short fiber For example, a method of fusing both non-woven fabric layers by heating and pressurizing a heat-fusible non-woven fabric layer formed by forming a fiber web formed by a card machine into a non-woven fabric by heat treatment can be employed.

In the present invention, the method of forming the spunbond nonwoven fabric layer (B) and forming the heat-fusible nonwoven fabric layer (A) on the spunbond nonwoven fabric layer (B) by the air-through method is a productivity. From this point of view, this is a more preferred embodiment.
(Thermal bonding of nonwoven fabric layer)
In the manufacturing process of the laminated nonwoven fabric of this invention, the process of thermally bonding the said nonwoven fabric layers can also be employ | adopted preferably.

  In the case of thermal bonding by hot air treatment, the hot air temperature is preferably in the range of the melting point of the lowest melting point component + 1 ° C to + 30 ° C among the resins used in all the nonwoven fabric layers to be bonded, Preferably it is the range of +1 degreeC or more and +15 degrees C or less, More preferably, it is the range of +1 degreeC or more and +10 degrees C or less. Sufficient thermal adhesiveness can be obtained by setting the hot air temperature to the melting point of the low melting point component + 1 ° C. or higher. Further, by setting the hot air temperature to preferably the melting point of the low melting point resin + 30 ° C. or less, more preferably + 15 ° C. or less, and even more preferably 10 ° C. or less, curing of the nonwoven fabric due to heat can be suppressed, and disposable diapers, etc. As a sanitary material non-woven fabric, a soft texture can be maintained.

In the present invention, the hot air flow rate is preferably 1.0 m / second or more and 5.0 m / second or less. By setting the hot air flow rate to 1.0 m / second or more, hot air can be passed through the nonwoven fabric for sanitary material, and sufficient adhesiveness can be obtained. On the other hand, the web turbulence at the time of heat processing can be suppressed by making hot air flow rate into 5.0 m / sec or less.
(Heat treatment process)
For the purpose of improving the adhesiveness between the nonwoven fabric layers or obtaining a laminated nonwoven fabric having a predetermined thickness, a heat treatment process such as heat and pressure treatment, that is, embossing or calendering can also be preferably employed.

  The embossed adhesion area ratio in embossing is preferably 5% or more and 30% or less. When the adhesion area is preferably 5% or more, more preferably 10% or more, a practically usable strength can be obtained. On the other hand, when the embossed adhesion area ratio is preferably 30% or less, more preferably 20% or less, a soft texture can be maintained.

  The embossed adhesion area ratio here refers to the entire nonwoven fabric in the portion where the convex portion of the upper roll and the convex portion of the lower roll overlap and contact the fiber web when heat bonding is performed with a pair of concave and convex rolls. It means the ratio. Moreover, when heat-processing with the roll which has an unevenness | corrugation, and a flat roll, it means the ratio for which the convex part of the roll which has an unevenness | corrugation accounts for the whole nonwoven fabric of the part contact | abutted to a fiber web.

  As the shape of the engraving applied to the hot embossing roll, shapes such as a circle, an ellipse, a square, a rectangle, a parallelogram, a rhombus, a regular hexagon, and a regular octagon can be used.

  The surface temperature of the hot embossing roll is preferably set to −50 ° C. or more and −1 ° C. or less with respect to the melting point of the resin having the lowest melting point among the resins used in all the nonwoven fabric layers. By sufficiently setting the surface temperature of the hot embossing roll to the melting point of the resin having the lowest melting point, preferably −50 ° C. or more, more preferably −30 ° C. or more, and further preferably −10 ° C. or more. It is possible to make it easy to suppress the occurrence of fluff by heat bonding to give strength. On the other hand, among the resins used, the melting point of the resin having the lowest melting point is preferably -1 ° C. or less, thereby facilitating prevention of separation between the resins due to fiber melting. it can.

  On the other hand, the temperature of the calender roll during the heat treatment by calendering is preferably set to −1 ° C. or lower with respect to the melting point of the resin which is the lowest melting point component. By setting the calender roll temperature to −1 ° C. or lower with respect to the melting point of the low melting point component, the surface of the nonwoven fabric after the heat treatment can be prevented from curing. The calender roll temperature can be appropriately adjusted depending on the thickness of the target nonwoven fabric.

  The linear pressure of the roll during heat treatment by calendering or embossing is preferably 10 N / cm or more and 500 N / cm or less. When the linear pressure is preferably 10 N / cm or more, more preferably 15 N / cm or more, and still more preferably 20 N / cm or more, sufficient heat treatment can be performed and the thickness can be controlled. On the other hand, the above-mentioned linear pressure is preferably 500 N / cm or less, more preferably 400 N / cm or less, and even more preferably 300 N / cm or less, thereby maintaining the texture of the nonwoven fabric so that the roll is not stressed excessively. can do. The linear pressure of the roll can be appropriately adjusted depending on the thickness of the target nonwoven fabric.

  As a surface material of the hot embossing roll, in order to obtain a sufficient thermocompression bonding effect and to prevent the engraving (uneven portion) of one embossing roll from being transferred to the other roll surface, a metal roll and a metal roll are used. Pairing is a preferred embodiment.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are not intended to limit the present invention, and any design change in accordance with the gist described in the present specification is a technique of the present invention. It is included in the scope.
[Measuring method]
Regarding the measurement method, unless otherwise specified, it is assumed that the measurement was performed by the method described above.

(1) MFR of polyolefin resin (g / 10 min):
The MFR of the polyolefin resin was measured under the conditions of a load of 2.16 kg and a temperature of 230 ° C. according to ASTM D1238 (Method A).

(2) MFR (g / 10 minutes) of the laminated nonwoven fabric measured with the heat-fusible nonwoven fabric layer (A) removed:
The MFR of the laminated nonwoven fabric measured with the heat-fusible nonwoven fabric layer (A) removed was measured under the conditions of a load of 2.16 kg and a temperature of 230 ° C. according to ASTM D1238 (Method A).

(3) Average single fiber diameter (μm):
A value calculated by the following procedure was adopted as the average single fiber diameter (μm) of the fibers constituting each nonwoven fabric layer.
(A) Ten small piece samples (10 mm × 10 mm) are randomly collected from the laminated nonwoven fabric.
(B) Using a scanning electron microscope (SEM), take a cross-sectional photograph of 200 to 2000 times, and measure the width of 10 fibers from each layer in each sample.
(C) The average single fiber diameter (μm) of each layer is calculated from the average value of the measured values of 100 layers.

(4) Tensile strength of nonwoven fabric (N / 5 cm):
As the tensile strength in the longitudinal direction, a value measured as follows in accordance with 6.3.1 of JIS L1913 (2010) shall be adopted.
(A) Two test pieces having a width of 5 cm × 30 cm are collected from the laminated nonwoven fabric.
(B) A test piece is set on a tensile tester with a grip interval of 20 cm.
(C) A tensile test was performed at a tensile speed of 10 cm / min. The strength when the sample was broken was designated as tensile strength (N / 5 cm), and the elongation percentage when fractured was designated as the tensile elongation rate (%). The average value is calculated. The tensile strength was assumed to be 15 N / 5 cm or more, and the elongation was assumed to be 15% or more.

(5) Flexibility First, in the method for measuring the thickness of the laminated nonwoven fabric, the flexibility in the present invention is such that when the pressure applied by the presser foot is a normal 0.2 kPa (average value of 3 sheets), The thickness at the time of T ₀ ”and 2.0 kPa (average value of three sheets) is set to“ T ₁ ”, and the thickness of each laminated nonwoven fabric is measured, and the ratio of the thickness at this time (T _R = T ₁ / T ₀ ) Was calculated. If T _R is less than 60%, and that there is flexibility.

[Example 1]
(Heat-fusion nonwoven fabric layer (A))
Polyethylene terephthalate (PET) having a melting point of 260 ° C. and an intrinsic viscosity of 0.65 dl / g was used for the core component, and high-density polyethylene (HDPE) having a melting point of 130 ° C. and an MFR of 18 g / 10 min was used for the sheath component. Using a core-sheath type composite fiber having a core-sheath composite mass ratio of 50/50, an average single fiber diameter of 16.3 μm, and a cut length of 38 mm as raw cotton, a laminated fiber web was formed through a card process. Subsequently, the obtained laminated fiber web was heat-treated for 12 seconds using a heat treatment machine under conditions of a temperature of 130 ° C. and a hot air flow rate of 3.3 m / min to form a heat-fusible nonwoven fabric layer (A). The basis weight of the formed heat-fusible nonwoven fabric layer (A) was 19.8 g / m ² , the thickness was 1.50 mm, and the specific volume was 75.8 cm ³ / g.
(Spunbond nonwoven fabric layer (B))
Next, a polypropylene resin composed of a homopolymer having an MFR of 200 g / 10 min is melted by an extruder, and a spinning temperature is 235 ° C. and a single hole discharge amount is from a rectangular die having a hole diameter φ of 0.30 mm and a hole depth of 2 mm. After the yarn spun at 0.32 g / min is cooled and solidified, it is pulled and stretched by a rectangular ejector with compressed air having an ejector pressure of 0.35 MPa, and the heat-fusible nonwoven fabric layer (A) The spunbond nonwoven fabric layer (B) was formed by collecting on the laminated nonwoven fabric. At this time, the basis weight of the spunbond nonwoven fabric layer (B) separately collected on the collection net under the same conditions was 8.0 g / m 2 and the average single fiber diameter was 10.1 μm. As for the spinnability, no yarn breakage was observed after spinning for 1 hour.
(Laminated nonwoven fabric)
The laminated body of the heat-fusible nonwoven fabric layer (A) and the spunbonded nonwoven fabric layer (B) formed as described above for 12 seconds using a heat treatment machine at a temperature of 160 ° C. and a hot air flow rate of 3.3 m / min. Heat treatment was performed to obtain a laminated nonwoven fabric. The evaluation results of the obtained laminated nonwoven fabric are shown in Tables 1 and 2.

[Example 2]
(Heat-fusion nonwoven fabric layer (A))
A heat-fusible nonwoven fabric layer (A) was formed by the same method as in Example 1 except that the average single fiber diameter was changed. The formed heat-fusible nonwoven fabric layer (A) was evaluated by the method described above. The basis weight was 19.8 g / m ² , the thickness was 1.50 mm, and the specific volume was 75.8 cm ³ / g.
(Spunbond nonwoven fabric layer (B))
A spunbond nonwoven fabric layer (B) made of polypropylene long fibers was formed by the same method as in Example 1 except that the MFR of the polypropylene resin made of a homopolymer was changed to 800 g / 10 min. At this time, the basis weight of the spunbond nonwoven fabric layer (B) separately formed on the collection net under the same conditions was 8.0 g / m ² and the average single fiber diameter was 8.9 μm. As for the spinnability, no yarn breakage was observed after spinning for 1 hour.
(Laminated nonwoven fabric)
A laminated nonwoven fabric was obtained in the same manner as in Example 1. The evaluation results of the obtained laminated nonwoven fabric are shown in Tables 1 and 2.

[Example 3]
(Heat-fusion nonwoven fabric layer (A))
A heat-fusible nonwoven fabric layer (A) was obtained by the same method as in Example 1 except that the average single fiber diameter was changed. The formed heat-fusible nonwoven fabric layer (A) was evaluated by the method described above. The basis weight was 20.4 g / m ² , the thickness was 1.56 mm, and the specific volume was 76.5 cm ³ / g.
(Spunbond nonwoven fabric layer (B))
A spunbonded non-woven fabric layer (B) made of polypropylene long fibers by the same method as in Example 1 except that the MFR of the polypropylene resin made of a homopolymer was 155 g / 10 min and the single hole discharge amount, ejector pressure, and basis weight were changed. Formed. At this time, the basis weight of the spunbond nonwoven fabric layer (B) separately formed on the collection net under the same conditions was 15.0 g / m ² and the average single fiber diameter was 11.8 μm. As for the spinnability, no yarn breakage was observed after spinning for 1 hour.
(Laminated nonwoven fabric)
A laminated nonwoven fabric was obtained in the same manner as in Example 1. The evaluation results of the obtained laminated nonwoven fabric are shown in Tables 1 and 2.

[Example 4]
(Heat-fusion nonwoven fabric layer (A))
A heat-fusible nonwoven fabric layer (A) was formed by the same method as in Example 1 except that the average single fiber diameter was changed. The formed heat-fusible nonwoven fabric layer (A) was evaluated by the method described above. The basis weight was 20.8 g / m ² , the thickness was 1.60 mm, and the specific volume was 76.9 cm ³ / g.
(Spunbond nonwoven fabric layer (B))
A spunbond nonwoven fabric layer (B) made of polypropylene long fibers was formed by the same method as in Example 1 except that the single hole discharge amount and the ejector pressure were changed. At this time, the basis weight of the spunbonded nonwoven fabric layer (B) separately formed on the collection net under the same conditions was 8.0 g / m ² and the average single fiber diameter was 11.8 μm. As for the spinnability, no yarn breakage was observed after spinning for 1 hour.
(Laminated nonwoven fabric)
A laminated nonwoven fabric was obtained in the same manner as in Example 1. The evaluation results of the obtained laminated nonwoven fabric are shown in Tables 1 and 2.

[Example 5]
(Heat-fusion nonwoven fabric layer (A))
The heat-fusible nonwoven fabric layer (A) was formed by the same method as in Example 1 except that the basis weight was changed. The formed heat-fusible nonwoven fabric layer (A) was evaluated by the method described above. The basis weight was 10.4 g / m ² , the thickness was 0.70 mm, and the specific volume was 67.3 cm ³ / g.
(Spunbond nonwoven fabric layer (B))
The same spunbond nonwoven fabric layer (B) as in Example 1 was used.
(Laminated nonwoven fabric)
A laminated nonwoven fabric was obtained in the same manner as in Example 1. The evaluation results of the obtained laminated nonwoven fabric are shown in Tables 1 and 2.

[Example 6]
(Heat-fusion nonwoven fabric layer (A))
The heat-fusible nonwoven fabric layer (A) was formed by the same method as in Example 1 except that the basis weight was changed. The formed heat-fusible nonwoven fabric layer (A) was evaluated by the method described above. The basis weight was 15.5 g / m ² , the thickness was 1.10 mm, and the specific volume was 71.0 cm ³ / g.
(Spunbond nonwoven fabric layer (B))
A polypropylene resin made of a homopolymer having an MFR of 155 g / 10 min is melted by an extruder, and a spinning temperature is 235 ° C. and a single hole discharge amount is 0.32 g from a rectangular die having a hole diameter φ of 0.30 mm and a hole depth of 2 mm. After the yarn spun at / min was cooled and solidified, the spunbond nonwoven fabric layer (B) was formed on the collection net by pulling and stretching with compressed air with an ejector pressure of 0.38 MPa using a rectangular ejector. . At this time, the basis weight of the spunbond nonwoven fabric layer (B) was 15.0 g / m ² and the average single fiber diameter was 10.1 μm. As for the spinnability, no yarn breakage was observed after spinning for 1 hour. Two layers of this spunbond nonwoven fiber web were used as described below.
(Laminated nonwoven fabric)
A laminated product in which the spunbond nonwoven fabric layer (B) is placed on the heat-fusible nonwoven fabric layer (A) formed above, and further the spunbond nonwoven fabric layer (B) is placed thereon, and the upper roll is made of metal with a polka dot pattern. Using an embossed roll with an adhesion area ratio of 16% engraved with a pair of upper and lower hot embossing rolls composed of a metal flat roll as the lower roll, a clearance of 1.0 mm and a thermal bonding temperature of 80 ° C. To obtain a laminated nonwoven fabric. The results of evaluating the obtained laminated nonwoven fabric are shown in Tables 1 and 2.

[Example 7]
(Heat-fusion nonwoven fabric layer (A))
A heat-fusible nonwoven fabric layer (A) was formed by the same method as in Example 1 except that the average single fiber diameter was changed. The formed heat-fusible nonwoven fabric layer (A) was evaluated by the method described above. The basis weight was 9.8 g / m ² , the thickness was 1.00 mm, and the specific volume was 102 cm ³ / g.
(Spunbond nonwoven fabric layer (B))
The same spunbond nonwoven fabric layer (B) as in Example 1 was used.
(Laminated nonwoven fabric)
A laminated nonwoven fabric was obtained in the same manner as in Example 1. The evaluation results of the obtained laminated nonwoven fabric are shown in Tables 1 and 2.

[Example 8]
(Heat-fusion nonwoven fabric layer (A))
The heat-fusible nonwoven fabric layer (A) was formed by the same method as in Example 1 except that the basis weight was changed. The formed heat-fusible nonwoven fabric layer (A) was evaluated by the method described above. The basis weight was 10.1 g / m ² , the thickness was 0.70 mm, and the specific volume was 69.3 cm ³ / g.
(Spunbond nonwoven fabric layer (B))
A spunbond nonwoven fabric layer (B) made of polypropylene long fibers was formed by the same method as in Example 1 except that the MFR of the polypropylene resin made of a homopolymer was 800 g / 10 minutes and the basis weight was changed. At this time, the basis weight of the spunbond nonwoven fabric layer (B) separately formed on the collection net under the same conditions was 30 g / m ² , and the average single fiber diameter was 8.9 μm. As for the spinnability, no yarn breakage was observed after spinning for 1 hour.
(Laminated nonwoven fabric)
A laminated nonwoven fabric was obtained in the same manner as in Example 1. The evaluation results of the obtained laminated nonwoven fabric are shown in Tables 1 and 2.

[Comparative Example 1]
(Heat-fusion nonwoven fabric layer (A))
A heat-fusible nonwoven fabric layer (A) was formed by the same method as in Example 1 except that the average single fiber diameter and basis weight were changed. The formed heat-fusible nonwoven fabric layer (A) was evaluated by the method described above. The basis weight was 10.4 g / m ² , the thickness was 0.80 mm, and the specific volume was 76.9 cm ³ / g.
(Spunbond nonwoven fabric layer (B))
The same method as in Example 1 except that the MFR of the polypropylene resin made of a homopolymer was 35 g / 10 min, the single hole discharge rate was 0.50 g / min, the ejector pressure was 0.20 MPa, and the basis weight was changed. Thus, a spunbond fiber web composed of polypropylene long fibers was obtained. At this time, the properties of the spunbond long fibers separately collected on the collection net under the same conditions were a basis weight of 8 g / m ² and an average single fiber diameter of 14.0 μm.
(Laminated nonwoven fabric)
The spunbond nonwoven fabric layer (B) is placed on the formed heat-fusible nonwoven fabric layer (A), and the spunbond nonwoven fabric layer (B) is placed on the nonwoven fabric layer (B). Using an embossing roll with a bonding area ratio of 16% and a pair of upper and lower hot embossing rolls composed of a metal flat roll as the lower roll, a linear pressure of 300 N / cm and a thermal bonding temperature of 145 ° C. The laminated nonwoven fabric was obtained by heat bonding. The results of evaluating the obtained laminated nonwoven fabric are shown in Tables 1 and 2.

[Comparative Example 2]
(Heat-fusion nonwoven fabric layer (A))
The same heat-fusible nonwoven fabric layer (A) as in Example 1 was formed, and then the adhesive area ratio of the upper heat-rollable nonwoven fabric layer (A) made of metal and engraved with a polka dot pattern was 16 % Of the embossing roll is thermally bonded under the conditions of a linear pressure of 300 N / cm and a heat bonding temperature of 80 ° C. using a pair of upper and lower heat embossing rolls composed of a metal flat roll as the lower roll, and heat fusion The non-woven fabric layer (A) was formed. The formed heat-fusible nonwoven fabric layer (A) was evaluated by the method described above. The basis weight was 22.0 g / m ² , the thickness was 0.20 mm, and the specific volume was 10.1 cm ³ / g.
(Spunbond nonwoven fabric layer (B))
A spunbond nonwoven fabric layer (B) made of polypropylene long fibers was formed by the same method as in Example 1 except that the single-hole discharge rate was 0.43 g / min and the ejector pressure was 0.30 MPa. At this time, the basis weight of the spunbond nonwoven fabric layer (B) separately formed on the collection net under the same conditions was 30.0 g / m ² and the average single fiber diameter was 12.9 μm.
(Laminated nonwoven fabric)
A laminated nonwoven fabric was obtained in the same manner as in Example 1. The evaluation results of the obtained laminated nonwoven fabric are shown in Tables 1 and 2.

[Comparative Example 3]
(Heat-fusion nonwoven fabric layer (A))
In the comparative example 3, what was corresponded to a heat-fusible nonwoven fabric layer (A) was not used for the laminated nonwoven fabric.
(Spunbond nonwoven fabric layer (B))
By the same method as in Example 1, a spunbond nonwoven fabric layer (B) made of polypropylene long fibers was formed. The spunbond long fibers thus formed had a basis weight of 15.0 g / m ² and an average single fiber diameter of 10.1 μm.
(Laminated nonwoven fabric)
The spunbond nonwoven fabric layer (B) is placed on the spunbond nonwoven fabric layer (B), a metal embossed roll with a polka dot pattern engraved on the upper roll and a metal flat on the lower roll. Using a pair of upper and lower hot embossing rolls composed of rolls, a laminated nonwoven fabric having a basis weight of 32.2 g / m ² was obtained by thermal bonding under conditions of a linear pressure of 300 N / cm and a thermal bonding temperature of 125 ° C. The results of evaluating the obtained laminated nonwoven fabric are shown in Tables 1 and 2.

[Comparative Example 4]
(Heat-fusion nonwoven fabric layer (A))
The heat-fusible nonwoven fabric layer (A) was formed by the same method as in Example 1 except that the basis weight was changed. The formed heat-fusible nonwoven fabric layer (A) was evaluated by the method described above. The basis weight was 10.4 g / m ² , the thickness was 0.80 mm, and the specific volume was 76.9 cm ³ / g.
(Spunbond nonwoven fabric layer (B))
In Comparative Example 4, the (laminated) non-woven fabric corresponding to the spunbond non-woven fabric layer (B) was not used.
(Nonwoven fabric)
The heat-fusible nonwoven fabric layer (A) was heat-treated for 12 seconds using a heat treatment machine at a temperature of 160 ° C. and a hot air flow rate of 3.3 m / min to obtain a non-laminated nonwoven fabric. Tables 1 and 2 show the evaluation results of the obtained nonwoven fabric.

A heat-bondable nonwoven fabric layer (A) containing a composite fiber composed of two or more components of a thermoplastic resin, and a spunbond nonwoven fabric layer composed of a polyolefin resin (Pb) having an average single fiber diameter of 6.5 μm to 11.9 μm The laminated nonwoven fabrics of Examples 1 to 8, which are composed of (B) and have a specific volume of 10 cm ³ / g or more, have a small thickness ratio (T _R ), excellent flexibility, and appropriate tensile strength. It was excellent in elongation.

On the other hand, the laminated nonwoven fabric of Comparative Example 1 having an average single fiber diameter of 11.9 μm or more, Comparative Example 2 which is a laminated nonwoven fabric having a specific volume of less than 10 cm ³ / g, and a laminated layer composed only of the spunbond nonwoven fabric layer (B). In the comparative example 3 which is a nonwoven fabric, it was inferior to a softness | flexibility. Further, Comparative Example 4 which is a nonwoven fabric composed only of the heat-fusible nonwoven fabric layer (A) was excellent in flexibility but inferior in tensile strength and elongation.

  The laminated nonwoven fabric of the present invention has practical strength and elongation, is delicate and soft, and has a surface touch feeling such as adapting to the skin. It can be suitably used in a wide range of fields including applications.

Claims (6)

A heat-fusible nonwoven fabric layer (A) and a spunbonded nonwoven fabric layer (B) are laminated, and a thermoplastic resin having two or more components as fibers (Fa) constituting the heat-fusible nonwoven fabric layer (A). The fiber (Fb) constituting the spunbond nonwoven fabric layer (B) is made of a polyolefin resin (Pb), and the average single fiber diameter is 6.5 μm or more and 11. A laminated nonwoven fabric having a fiber of 9 μm or less and a specific volume of 10 cm ³ / g or more.   The laminated nonwoven fabric according to claim 1, wherein an average single fiber diameter of the fibers (Fa) is 7 µm or more and 24 µm or less.   The laminated nonwoven fabric according to claim 1 or 2, wherein a proportion of the heat-fusible nonwoven fabric layer (A) in the thickness direction is 40% or more and 98% or less.   The laminated nonwoven fabric according to any one of claims 1 to 3, wherein an MFR of a component constituting the spunbonded nonwoven fabric layer (B) is 80 g / 10 min or more and 850 g / 10 min or less. The longitudinal tensile strength per unit weight of the laminated nonwoven fabric is 1.8 (N / 5 cm) / (g / m ² ) or more and 3.5 (N / 5 cm) / (g / m ² ) or less. The laminated nonwoven fabric according to any one of claims 1 to 4.   The fiber (Fa) constituting the heat-fusible nonwoven fabric layer (A) further includes one or more kinds of fibers (Fa2) in addition to the composite fiber (Fa1). The laminated nonwoven fabric described.