JP2019043102A - Laminate sheet and manufacturing method thereof - Google Patents

Abstract

To provide a laminate sheet which has an excellent inhibitory effect on liquid diffusion such as loose stool and menstrual blood.SOLUTION: The laminate sheet 1 has a long fiber unwoven fabric layer 20 containing hydrophobic long fibers 21, and a cellulose fiber layer 25 arranged on one side or both sides of the long fiber unwoven fabric layer 20 and constituted mainly by cellulose fibers 26. The long fiber unwoven fabric layer 20 has: a plurality of recesses 23 and protrusions 22 on a surface in contact with the cellulose fiber layer 25, the cellulose fiber layer is laminated on the recesses 23, boundary surfaces of the long fiber unwoven fabric layer 20 and the cellulose fiber layer 25 are in a close contact state; and ventilation resistance as the laminate sheet 1 of 0.001 kPa s/m to 0.08 kPa s/m.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminated sheet and a method of manufacturing the same.

  It is known to use a sheet made of non-woven fabric or pulp as a member of absorbent articles such as disposable diapers and sanitary napkins. For example, in Patent Document 1, a surface material of a sanitary material such as a disposable diaper is characterized in that a spunbond nonwoven fabric and a thin paper are laminated, and the spunbond nonwoven fabric side is in contact with the skin. Is described. According to Patent Document 1, the body fluid is favorably transmitted through the surface material by the liquid absorbing force of the pulp fibers constituting the thin paper.

  Further, in Patent Document 2, a spunbond nonwoven fabric having a core-sheath structure and containing fibers of a heat-fusible resin whose sheath portion has a melting point lower than that of the core portion, and continuous or discontinuous by wet papermaking on the nonwoven fabric surface And the nonwoven fabric and the papermaking layer are joined via the low melting point heat melting resin of the sheath portion of the spunbonded nonwoven fabric. Composite paper is described.

Unexamined-Japanese-Patent No. 05-176954 Japanese Patent Application Laid-Open No. 05-279997

Absorbent articles such as disposable diapers and sanitary napkins generally comprise an absorbent that absorbs waste fluid. The absorbent has an absorbent core made of a piled body such as hydrophilic fibers and a core wrap sheet for covering the absorbent core. As the core wrap sheet, paper such as tissue paper obtained by a wet papermaking method is widely used. Such a core wrap sheet has a relatively narrow gap between fibers, so there is room for improvement in the permeability of highly viscous liquids such as soft stools and menstrual blood.
Moreover, the sheets described in Patent Documents 1 and 2 are also insufficient in the permeability of highly viscous liquids such as soft stools and menstrual blood.

  Accordingly, an object of the present invention is to provide a laminate sheet and a method for producing the same, and an absorbent article using the laminate sheet, which can solve the above-mentioned drawbacks of the prior art.

  The present invention is a laminated sheet having a long-fiber non-woven fabric layer containing hydrophobic long-fibers and a cellulose-based fiber layer mainly composed of cellulose-based fibers provided on one side or both sides of the long-fiber non-woven fabric layer. The long fiber non-woven fabric layer has a plurality of recesses and protrusions on the surface in contact with the cellulose fiber layer, and the cellulose fiber layer is stacked on the recess, the long fiber non-woven fabric There is provided a laminated sheet in which the interface between the layer and the cellulose fiber layer is in close contact, and the air flow resistance as the laminated sheet is 0.001 kPa · s / m or more and 0.08 kPa · s / m or less. It is a thing.

Further, the present invention supplies a slurry containing the above-mentioned cellulose-based fibers onto a base sheet consisting of a long-fiber non-woven fabric containing hydrophobic long-fibers, and forms the above-mentioned cellulose-based fiber layer on the above-mentioned base sheet It provides a manufacturing method of a lamination sheet which comprises the papermaking process to form, and makes the neck-in rate obtained by the following formula (1) 20% or less.
Neck-in rate (%) = (W ₀ −W ₁ ) / W ₀ × 100 (1)
W ₀ : length of the base sheet in a direction orthogonal to the conveying direction of the base sheet W ₁ : length of the laminated sheet in the orthogonal direction

  The present invention also provides an absorbent article using the above-mentioned laminated sheet as a core wrap sheet for covering an absorbent core.

The laminated sheet of the present invention is excellent in the effect of suppressing liquid diffusion such as soft stool and menstrual blood.
According to the method for producing a laminated sheet of the present invention, it is possible to efficiently produce a laminated sheet excellent in the effect of suppressing liquid diffusion such as soft stool and menstrual blood.
The absorbent article of the present invention is excellent in the effect of suppressing liquid diffusion such as soft stool and menstrual blood.

FIG. 1 is a cross-sectional view along the thickness direction showing one embodiment of the laminated sheet of the present invention. Fig.2 (a) is an expanded sectional view which shows the principal part of the lamination sheet shown in FIG. 1, FIG.2 (b) is an expanded sectional view which shows the sheet | seat which does not comprise the structure of this invention. FIG. 3 is an enlarged cross-sectional view schematically showing a long-fiber non-woven fabric layer according to the present invention. FIG. 4 is a cross-sectional view of an absorbent article using the laminated sheet according to the present invention as a core wrap sheet. FIG. 5 is a schematic view showing an apparatus suitably used for producing the laminated sheet of the embodiment shown in FIG.

Hereinafter, the present invention will be described based on its preferred embodiments with reference to the drawings. FIG. 1 shows a cross-sectional view along the thickness direction of an embodiment of the laminated sheet 1 of the present invention.
As shown in FIG. 1, the laminated sheet 1 is mainly composed of a long-fiber non-woven fabric layer 20 containing hydrophobic long-fibers 21 and cellulose fibers 26 provided on one side or both sides of the long-fiber non-woven fabric layer 20. Has a laminated structure with the cellulose fiber layer 25.
In FIG. 1, for convenience of explanation of the present invention, the long fibers 21 and the cellulose fibers 26 are shown by lines of different thicknesses, but they are irrelevant to the actual thicknesses of the two fibers 21 and 26.

The long fiber non-woven fabric layer 20 includes a long fiber non-woven fabric including hydrophobic long fibers 21 as its constituent material. Examples of long fiber non-woven fabrics include spunbond non-woven fabrics and laminated non-woven fabrics having a spunbond layer and a meltblown layer, etc. Spunbond-meltblown (SM) non-woven fabrics as a laminated non-woven fabric having a spunbond layer and a meltblown layer Examples include spunbond-meltblown-spunbond laminate nonwoven (SMS nonwoven), spunbond-meltblown-meltblown-spunbond nonwoven (SMMS nonwoven), spunbond-spunbond-meltblown-spunbond (SSMS) nonwoven and the like.
The long-fiber non-woven fabric preferably has fused portions in which the constituent fibers are fused by heat sealing, ultrasonic sealing, embossing, etc. in a dispersed state in plan view, and preferably in a scattered point .
The long fiber nonwoven fabric constituting the long fiber nonwoven fabric layer 20 is preferably 50% or more, more preferably 50% or more, from the viewpoint of imparting sufficient hydrophobicity to the mass of the long fiber nonwoven fabric, of the blending ratio of hydrophobic long fibers. Is 70% or more, and is preferably 98% because it contains an additive such as an oil agent for imparting properties such as slipperiness and hydrophilicity and hydrophobicity required at the production stage of the non-woven fabric and a binder for maintaining strength. Or less, more preferably 90% or less, preferably 50% or more and 98% or less, and more preferably 70% or more and 90% or less.

Examples of the constituent resin of the hydrophobic long fibers 21 include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, and polyamides such as nylon, and these can be used alone or in combination of two or more. .
Whether the fiber is hydrophobic or not is judged based on the contact angle with water measured by the following method, and if the contact angle is less than 90 degrees, it is hydrophilic, if it is 90 degrees or more, it is hydrophobic It is sex. The smaller the contact angle with water measured by the following method, the higher the hydrophilicity (the lower the hydrophobicity), and the larger the contact angle, the lower the hydrophilicity (a higher hydrophobicity). In the laminated sheet 1, the contact angle of the long fibers 21 with water is 90 degrees or more. With such a configuration, when the high-viscosity liquid contacts the long-fiber non-woven fabric layer 20 of the laminated sheet 1, the hydrophobicity of the long-fiber non-woven fabric layer 20 prevents the high-viscosity liquid from diffusing onto the surface of the long-fiber non-woven fabric layer 20 can do. The long fibers may be treated with a hydrophilizing agent such as an oil agent or a water repellent as long as the effects of the present invention are not impaired.

<Method of measuring contact angle>
The fiber is taken out from the object to be measured (laminated sheet), and the contact angle of water to the fiber is measured. As a measuring device, an automatic contact angle meter MCA-J manufactured by Kyowa Interface Science Co., Ltd. is used. Deionized water is used to measure the contact angle. The amount of liquid discharged from an inkjet type water droplet discharge unit (manufactured by Cluster Technology, pulse injector CTC-25 having a discharge diameter of 25 μm) is set to 20 picoliter, and the water droplets are dropped right above the fibers. The state of dropping is recorded on a high-speed recording device connected to a camera installed horizontally. From the viewpoint of later image analysis, the recording device is preferably a personal computer in which a high-speed capture device is incorporated. In this measurement, an image is recorded every 17 msec. In the recorded video, the first image of a drop of water on the fiber, attached software FAMAS (version of software is 2.6.2, analysis method is the drop method, analysis method is the θ / 2 method, image processing algorithm Image analysis is performed with no reflection, image processing image mode is frame, threshold level is 200, curvature correction is not performed, and the angle between the surface of the water droplet that touches the air and the fiber is calculated. Be a corner. The fiber removed from the object to be measured is cut into a fiber length of 1 mm, and the fiber is placed on the sample table of the contact angle meter and kept horizontal. Two different contact angles are measured per fiber. A contact angle of N = 5 is measured to one decimal place, and a value obtained by averaging a total of ten measured values (rounded to the second decimal place) is defined as the contact angle of the fiber with water. The measurement environment is room temperature 22 ± 2 ° C. and humidity 65 ± 2% RH. The smaller the contact angle value, the higher the hydrophilicity.

  When the laminated sheet is used as a component such as an absorbent article and the laminated sheet is taken out for evaluation and measurement, the component is fixed to another component by an adhesive, fusion or the like. If so, the fixed part is removed after removing the adhesive force by blowing cold air cold air or the like within a range that does not affect the contact angle of the fiber. This procedure is common to all measurements herein.

  The diameter of the long fibers 21 is preferably 0.5 μm or more, more preferably 5 μm or more, preferably 50 μm or less, more preferably 30 μm or less, and preferably 0.5 μm to 50 μm or less, more preferably 5 μm More than 30 μm.

The bulk density of the long fibers 21 is preferably 0.01 g / cm ³ or more, more preferably 0.03 g / cm ³ or more, and preferably 0.2 g / cm ³ or less, more preferably 0.1 g / cm ^{3 It is 3} or less, and preferably 0.01 g / cm ³ or more and 0.2 g / cm ³ or less, more preferably 0.03 g / cm ³ or more and 0.1 g / cm ³ or less.
The bulk density is measured by using a laser displacement meter, placing a 5.6 cm diameter metal plate on long fibers, measuring the thickness (μm) under pressure of 50 Pa, and determining the basis weight (g / m ² ) The bulk density (g / cm ³ ) is calculated by dividing by the thickness (μm).

  The long-fiber non-woven fabric layer 20 has irregularities on the surface in contact with the cellulosic fiber layer 25. The unevenness of the long fiber non-woven fabric layer 20 of the present embodiment is, as shown in FIG. 2, composed of a plurality of recesses 23 and projections 22, and the basis weight of the long fibers 21 in the recesses 23 is lower than that of the projections 22. By doing this, the recess 23 and the protrusion 22 are formed. The unevenness of the long-fiber non-woven fabric layer is mainly formed due to the difference in basis weight (such as the texture) when it is produced by a spinning method such as spun bonding or meltblowing. Further, the difference between the average height of the surface in contact with the cellulose fiber layer 25 and the height of the long fiber non-woven fabric layer 20 in each recess or each protrusion does not exceed twice the average thickness of the long fiber non-woven fabric layer I assume. The average height of the surface in contact with the cellulose-based fiber layer 25, the height of the long-fiber non-woven fabric layer 20 in the recess 23 and the height of the long-fiber non-woven fabric layer 20 in the convex portion 22 will be described later. In addition to this, as a method of forming unevenness in the long fiber nonwoven fabric layer 20, embossing by heat or pressure, ultrasonic waves, etc. may be mentioned.

A cellulose-based fiber layer 25 mainly composed of cellulose-based fibers 26 is provided on one side or both sides of the long-fiber non-woven fabric layer 20. Examples of the cellulose-based fibers 26 include natural cellulose fibers such as wood pulp and cotton, and regenerated cellulose fibers such as rayon.
The content of the cellulose fiber 26 in the cellulose fiber layer 25 is preferably 50% or more, more preferably 70% or more from the viewpoint of imparting hydrophilicity, and a binder component for binding the cellulose fiber or wetting From the viewpoint of containing an agent such as paper strength, it is preferably 98% or less, more preferably 92% or less, and preferably 50% or more and 98% or less, more preferably 70% or more and 92% or less.
Moreover, the contact angle with the water of the cellulosic fiber 26 is less than 30 degrees.

  The long fiber non-woven fabric layer 20 and the cellulosic fiber layer 25 are in close contact with each other. Specifically, as shown in FIG. 2, in the cellulose fiber layer 25, the cellulose fiber 26 constituting the layer fills the inside of the recess 23 of the long fiber non-woven layer 20, thereby forming the long fiber non-woven layer 20. Since the contact is made between the two layers 20 and 25, substantially no adhesive is present at the interface between the two layers 20 and 25, and the long fibers and the cellulose fibers of each layer are in a sufficiently adhered state by contact and entanglement. On the other hand, when the adhesion between the long fiber non-woven fabric layer 20 and the cellulose fiber layer 25 is to be improved by the application of the adhesive, the adhesive agent intervenes between the long fiber 21 and the cellulose fiber 26. The distance between the fibers is increased, the air flow resistance is increased, and the hydrophilicity is decreased, so the permeability of the highly viscous liquid is significantly deteriorated. It is judged by the following confirmation test whether it adheres sufficiently here.

<Confirmation test of adhesion state>
First, the absence of the adhesive at the interface of both layers of the sample sheet is confirmed by microscopic observation.
The sample sheet is cut into 5 cm squares and folded in two. The folded sheet is sandwiched between 10 cm square plates, the weight is placed, and the pressure is applied to 3 kPa. The sheet is allowed to stand for 10 seconds to open the fold. This operation is repeated a total of three times so that the folding direction is the same, and the folds are also in the same position. Prepare another creased 5 cm square sheet and immerse the sheet in liquid nitrogen for 10 seconds, then use a sharp razor to cut the crease in the direction perpendicular to the crease with each sheet 3 Put in place.
Next, the cut cross section of the cut is observed using an SEM or an optical microscope to confirm the presence or absence of a gap between the long fiber nonwoven fabric layer 20 and the cellulose fiber layer 25, that is, the adhesion state. If there is a gap, measure the gap distance in the thickness direction of the gap portion. And if the average of the gap distance in all the cut sections is smaller than 1/2 of the average thickness of the laminated sheet 1, both layers of the present invention are "in close contact", according to 1/2 of the average thickness. If the size is large, it is considered as "not in close contact". That is, if both layers of the present invention are in a close contact state, the close contact state can be maintained even in a severe test such as the bending test, but if it is not in a close contact state, the gap distance becomes large by the bending test. . In addition, if the average of the gap distance is larger than 1⁄2 of the average thickness of the laminated sheet 1 which is much larger than the inter-fiber distance of each layer, it can be easily determined that a gap is formed. For example, while the fibers are strongly entangled and bound in each layer, when there is little contact or entanglement between long fibers and cellulosic fibers between the two layers, etc., the two layers should not be in close contact with each other. I can say that. In such a laminated sheet, there are many gaps locally, and furthermore, it is considered that the gaps are easily formed by a force applied to the laminated sheet (diaper wearing condition and the like).

  When the area of the sheet to be measured is less than 10 cm square, the above-mentioned bending is performed so as to obtain the same 3 kPa pressure condition, and the number of incisions for observing the cut cross section is also the same. Conduct a confirmation test.

The laminated sheet 1 in which the long fiber non-woven fabric layer 20 and the cellulose-based fiber layer 25 are laminated without gaps is a wet papermaking method using a slurry containing the cellulose-based fibers 26 with the long fiber non-woven fabric layer 20 described below as a base sheet. It can be manufactured.
From the viewpoint of filling the inside of the recess 23 of the long fiber non-woven fabric layer 20 with the cellulose fiber 26, the cellulose fiber 26 preferably has the following physical properties.
The average fiber length of the cellulose-based fibers 26 is preferably 0.5 mm or more, more preferably 2 mm or more, preferably 10 mm or less, more preferably 5 mm or less, and preferably 0.5 mm or more and 10 mm or less, more Preferably they are 2 mm or more and 5 mm or less.
The fiber width of the cellulose fiber 26, ie, the diameter of the cellulose fiber 26, is preferably 1 μm or more, more preferably 10 μm or more, preferably 80 μm or less, more preferably 50 μm or less, and preferably 1 μm to 80 μm. The thickness is preferably 10 μm or more and 50 μm or less.
The fiber roughness of the cellulosic fiber 26 is preferably 50 μg / m or more, and more preferably 150 μg / m or more. Since the bulk density of the cellulose-based fiber layer is low and the gaps between the fibers are large as the fiber roughness is large, in the laminated sheet, the liquid permeability is improved, and the liquid diffusibility described later is further suppressed. Also, from the viewpoint of securing the sheet strength, 500 μg / m or less is preferable. Moreover, preferably it is 50 to 500 μg / m, more preferably 150 to 500 μg / m.

<Measurement of average fiber length, fiber width and fiber roughness>
The cellulose fiber is identified and isolated from the sheet to be measured, and 1.5 g or more of a fiber sample is collected. In addition, the method of identifying and isolating a long fiber and a cellulose fiber is mentioned later.
It measures using a fiber roughness meter FS-200 (made by KAJAANI ELECTRONICS LTD.). First, in order to determine the true mass of the fiber to be measured, the fiber is dried at 100 ° C. for 1 hour in a vacuum dryer to remove the water present in the fiber. Accurately weigh 1 g from the fiber thus dried (error ± 0.1 mg). Next, the weighed fiber is completely disintegrated into 150 ml of water with a mixer attached to the fiber roughness meter, taking care not to damage the fiber as much as possible, and this is brought to a total volume of 5000 ml. Dilute with water to obtain a diluted solution. From the resulting diluted solution, 50 ml is accurately measured and used as a fiber roughness measurement solution, and the target average fiber length and fiber roughness are respectively calculated according to the operation procedure of the fiber roughness meter. In addition, the value calculated by following formula (2) based on the said operation procedure is used for calculation of an average fiber length.

The bulk density of the cellulose-based fiber 26 is preferably 0.01 g / cm ³ or more, more preferably 0.03 g / cm ³ or more from the viewpoint of securing the strength of the cellulose-based fiber layer, and the liquid permeability is secured In view of the above, it is preferably 0.5 g / cm ³ or less, more preferably 0.3 g / cm ³ or less, and preferably 0.01 g / cm ³ or more and 0.5 g / cm ³ or less, more preferably 0. 03g / cm ³ or more 0.3g / cm ³ or less.

  From the viewpoint of liquid permeability, the lower the air flow resistance, the better the air flow resistance of the laminated sheet 1. However, the lower limit of the structure of the laminated sheet of the present invention is 0.001, not 0. The upper limit is preferably 0.08 kPa · s / m or less, and more preferably 0.05 kPa · s / m or less. The air flow resistance is an index indicating the size of the space between the fibers. The smaller the air flow resistance, the larger the space between the fibers, and the larger the air flow resistance, the smaller the space between the fibers. The air flow resistance level referred to herein is measured using an air permeability tester “KES-F8-AP1 AIR PERMEABILITY TESTER” (trade name) manufactured by Kato Tech Co., Ltd. Specifically, the ventilation resistance at any 12 places in the sheet (laminated sheet) to be evaluated is measured according to a conventional method using a ventilation tester, and the average value is taken as the ventilation resistance of the sheet.

  The laminated sheet 1 of the present invention has the air flow resistance within the above-described range, and further, by having the hydrophobic long-fiber non-woven fabric layer 20 and the hydrophilic cellulose-based fiber layer 25, the laminated sheet 1 Has a hydrophilic gradient in the thickness direction of the Furthermore, the long-fiber non-woven fabric layer 20 and the cellulose-based fiber layer 25 are laminated without gaps, that is, in close contact with each other. With such a configuration, the laminated sheet 1 is excellent in the permeability of high viscosity liquids such as soft stools and menstrual blood, and the diffusion suppressing effect of the high viscosity liquid in the planar direction of the laminated sheet 1 (hereinafter referred to as liquid It is excellent in the diffusion suppression effect. Specifically, when the air flow resistance of the laminated sheet 1 is in the above range, the gaps between the fibers can be made appropriately large, so that the highly viscous liquid can be easily transmitted and excellent The effect of suppressing liquid diffusion is exhibited. In addition, by having a hydrophilic gradient in the thickness direction of the laminated sheet 1, the high-viscosity liquid is excellent in the drawability from the long-fiber non-woven fabric layer 20 to the cellulose-based fiber layer 25. Furthermore, by laminating the long fiber non-woven fabric layer 20 and the cellulose-based fiber layer 25 in close contact with each other, the high-viscosity liquid can be easily transmitted from the long fibers 21 to the cellulose-based fibers 26. Excellent in retractability. On the other hand, if there is a gap between the long-fiber non-woven fabric layer 20 and the cellulose-based fiber layer 25 [see FIG. 2 (b)], the conduction path of the high viscosity liquid is interrupted by the gap, making it difficult to draw the high viscosity liquid. .

The method of measuring the basic weight of a long fiber nonwoven fabric and a cellulose fiber is shown. Methods of identifying cellulose fibers in the laminated sheet include shape observation by a SEM image and a staining method (JIS P 8120), a method of hydrolyzing cellulose, and then analyzing constituent sugars by an HPLC method etc. The method of can be used. Further, since the long-fiber non-woven fabric is a continuous fiber uninterrupted in the length direction, it can be identified by an image of low magnification, and the type of resin constituting the fiber can be specified by DSC (differential thermal analysis device). The basis weight of the long-fiber non-woven fabric layer and the cellulose-based fiber layer in the laminated sheet can be determined by measuring the weight per unit area of each of the isolated layers when the layers can be isolated by delamination with an adhesive tape or the like. If it can not be isolated, the average thickness of each layer 20, 25 is measured from the photograph of the cross-sectional area of the laminated sheet, and the ratio of the average thickness of each layer 20, 25 to the average thickness of laminated sheet 1 is the basis weight of the entire laminated sheet Calculate the basis weight of each layer by multiplying it by the amount.

The basis weight of the long-fiber nonwoven fabric layer 20 in order to ensure the strength of the laminated sheet 1, preferably 5 g / m ² or more, more preferably 8 g / m ² or more, to ensure the permeability of the high-viscosity liquid or the like Therefore, it is preferably 15 g / m ² or less, more preferably 12 g / m ² or less, and preferably 5 g / m ² or more and 15 g / m ² or less, more preferably 8 g / m ² or more and 12 g / m ² or less . It is preferable that the long fiber non-woven fabric 21a constituting the long fiber non-woven fabric layer 20 has a basis weight within the above range.

Also, from the viewpoint of making it more hydrophilic to improve the permeability of the high viscosity liquid, the basis weight of the cellulose fiber layer 25 is preferably 0.5 g / m ² or more, more preferably 1 g / m ² or more, Moreover, in order to increase the space | gap between fibers and to ensure the permeability of a highly viscous liquid, it is preferably 10 g / m ² or less, more preferably 6 g / m ² or less, and preferably 0.5 g / m ² or more. / ^{m 2} or less, more preferably 6 g / ^{m 2} or less 1 g / ^{m 2} or more.

In the laminated sheet 1 of the present embodiment, as shown in FIG. 1, a part of the cellulose-based fibers penetrates through the cellulose-based fibers 27 in the thickness direction from one side of the long fiber nonwoven fabric layer 20 to the other side. Have. Such a configuration can further improve the drawability of the highly viscous liquid. Thus, in the laminated sheet 1, it is preferable that a part of the cellulose-based fibers 26 penetrate the long fiber nonwoven fabric layer 20 and be exposed on one side of the long fiber nonwoven fabric layer 20. The fact that it is exposed on one side is confirmed by the method for confirming penetrating cellulose-based fibers described later in the examples of the present invention.
The number per unit area (10 cm ² ) of the penetrating cellulose-based fibers 27 in the long fiber nonwoven fabric layer 20 is preferably 3 or more and 300 or less, more preferably 10 or more and 100 or less.

The long-fiber non-woven fabric layer 20 has irregularities on the surface in contact with the cellulose-based fiber layer 25. The concave and convex portions constituting the unevenness are embossed, for example, on the long-fiber non-woven fabric 21a which is the substrate sheet 20a. It can be formed. In this case, from the viewpoint of improving the capillary force in the recess 23 in which the long fibers 21 are densified by embossing, and preventing the formation of a gap between the long fiber nonwoven fabric layer 20 and the cellulose fiber layer 25, The area ratio of the recesses 23 constituting the unevenness is preferably 3% or more, more preferably 5% or more, still more preferably 11% or more, and preferably 35% or less, more preferably 28% or less, more preferably Is 18% or less, preferably 3% or more and 35% or less, more preferably 5% or more and 28% or less, and still more preferably 11% or more and 18% or less.
The area ratio of the recess is obtained by image analysis of a photograph of the actual product. At this time, if there is a fiber loss portion in the recess, manual correction is performed, and it is measured assuming that the fiber is present.

From the same point of view, the thickness t2 of the long-fiber non-woven fabric layer 20 in the concave portion 23 constituting the unevenness formed by embossing is preferably 10% or more with respect to the average thickness t1 of the long-fiber non-woven fabric layer 20 It is preferably 30% or more, preferably 90% or less, more preferably 60% or less, and preferably 10% or more and 90% or less, more preferably 30% or more and 60% or less. The average thickness t1 of the long-fiber non-woven fabric layer 20 and the thickness t2 of the recess are defined as follows. The distance (difference) t1 between the average height positions h1 and h2 on the surfaces 21c and 21d of the long-fiber non-woven fabric layer 20 is called the average thickness of the long-fiber non-woven fabric layer 20 (see FIG. 3). In addition, the concave portion 23 refers to a region in a state of being recessed to the other surface side from the average height on one surface of the long fiber nonwoven fabric layer 20, and as shown in FIG. Distance (difference) t2 between the height position h3 and the average height (the average height h1 of the surface 21c in FIG. 3) on the other surface opposite to the surface on which the recess 23 is formed The thickness of the long fiber nonwoven fabric layer 20 at 23 is called. The convex portion 22 refers to a region in a state in which the convex portion 22 protrudes beyond the average height of one surface of the long fiber non-woven fabric layer 20, and the height position h4 of the most protruding portion 22a of the convex portion 22 The distance (difference) t3 to the average height (the average height h1 of the surface 21c in FIG. 3) on the surface opposite to the surface on which the portion 22 is formed is called the thickness of the long fiber non-woven layer 20 in the convex portion 22. . The surface shape of the long-fiber non-woven fabric layer 20 is measured by image analysis of a cross-sectional photograph such as a SEM image or the like and a method according to JIS B 0601 such as a surface roughness measuring device.

  The laminated sheet 1 of the present invention is excellent in the permeability of the high-viscosity liquid as described above, and is suitable for various applications in which such features are utilized. In particular, the laminated sheet 1 is suitable as a core wrap sheet for covering a liquid-retaining absorbent core in absorbent articles such as disposable diapers and sanitary napkins. The laminated sheet 1 of the present invention is particularly effective for highly viscous liquids such as soft stools and menstrual blood, and thus is particularly useful as a core wrap sheet in disposable diapers.

  An example of an absorbent article using the laminate sheet 1 is an absorbent article comprising an absorbent core 14 a and a core wrap sheet 14 b covering the same, wherein the core wrap sheet 14 b is the laminate sheet 1. The thing is mentioned. More specifically, the absorbent article (diaper 100) using the laminated sheet 1 has, in its longitudinal direction, a ventral side located on the ventral side of the wearer when worn, a dorsal side located on the dorsal side, and It has a crotch disposed between the ventral side and the dorsal side. In addition, as shown in FIG. 4, the diaper 100 has a liquid-permeable top sheet 12 forming a skin-facing surface, a liquid-impervious or water-repellent back sheet 13 forming a non-skin-facing surface, and both sheets. A liquid-retaining absorber 14 is provided between 12, 13. The diaper 100 has a sheet 15 for forming a solid gather having an elastic member 15a, and the contraction of the elastic member 15a causes the solid gather to stand up toward the skin of the wearer in the crotch in the worn state. It is formed. Furthermore, the leg elastic member 16 is arranged in an extended state at the part arranged around the leg of the crotch, and the contraction thereof improves the fit around the leg of the wearer to the crotch in the wearing state. Leg gathers are formed.

  The absorber 14 is comprised including the absorptive core 14a and the core wrap sheet 14b (lamination sheet 1), as shown in FIG. The laminated sheet 1 used as the core wrap sheet 14 b preferably covers at least the skin-facing surface of the absorbent core 14 a. In that case, the lamination sheet 1 is disposed by arranging the lamination sheet 1 so that the surface sheet 12 and the long-fiber non-woven fabric layer 20 of the lamination sheet 1 face each other between the surface sheet 12 and the absorbent core 14a. In particular, the long fiber non-woven fabric layer 20 comes in contact with feces such as stool earlier than the cellulosic fiber layer 25. In addition, a skin opposing surface is a surface in an absorbent article or its constituent member (for example, an absorbent core) directed to the skin side of a wearer when wearing an absorbent article, and a non-skin facing surface is an absorbent article or It is a surface in the component, which is directed to the opposite side (dressing side) to the skin side when the absorbent article is worn. As the top sheet 12, the back sheet 13, and the absorbent core 14a, those generally used in absorbent articles of this type can be used without particular limitation. The absorbent article using the laminated sheet 1 can be applied to a spreadable or pant-type disposable diaper, a sanitary napkin, an incontinence pad, and the like.

Next, an embodiment of a method of producing the laminated sheet 1 of the present invention will be described with reference to FIG. FIG. 5 shows a wet papermaking machine 3 capable of preferably producing the laminated sheet 1 of the present invention. The wet papermaking machine 3 includes a papermaking net 31, a slurry feeding device 32, a press roll 34 and a Yankee drier 35.
The manufacturing method of the present embodiment includes a sheet-making step of forming a cellulose-based fiber layer by adding a slurry containing a cellulose-based fiber to a base sheet 20a composed of a long-fiber non-woven fabric 21a mainly composed of long fibers. Further, the manufacturing method of the present embodiment includes a dewatering step of dewatering the formed sheet obtained in the sheet-forming step, a drying step of drying the dewatered formed sheet, and a winding step of winding up the dried formed sheet. including.

  The paper making process will be described. In the paper making process, as shown in FIG. 5, the slurry 26a containing the cellulose fiber 26 is supplied onto the base sheet 20a consisting of the long fiber non-woven fabric 21a containing the hydrophobic long fiber 21 and the wet paper making method In this step, the cellulose fiber layer 25 is formed on the material sheet 20a. Specifically, the long-fiber non-woven fabric 21a supplied from the long-fiber non-woven fabric roll 21b is used as the base material sheet 20a, and the base material sheet 20a is placed on the papermaking mesh 31. The slurry 26 a containing the cellulose fiber 26 is poured from the slurry feeder 32. The water in the poured slurry 26a passes sequentially through the base sheet 20a and the papermaking mesh 31 and flows down from below the papermaking mesh 31, and the cellulose-based fibers 26 in the slurry 26a are constituent fibers of the base sheet 20a. The long fibers 21 are entangled in the base sheet 20a, whereby the formed sheet 10 containing the long fibers 21 and the cellulose-based fibers 26 is formed on the paper mesh 31. The formed sheet 10 is delivered from the papermaking net 31 to a belt conveyor 37a.

  The slurry containing cellulose-based fibers can contain fiber components other than the cellulose-based fibers, and examples of the fiber components include polyolefin resins such as polyethylene (PE) and polypropylene (PP), polyethylene terephthalate (PET), The fiber which contained polyester-type resin, such as a polybutylene terephthalate (PBT), individually or in 2 or more components, an acrylic fiber, a nylon fiber, a urethane fiber, an animal hair fiber etc. are mentioned. The slurry may also contain a wet strength agent, a dry strength agent, a texture improver, a retention improver, a coagulant, a pH adjuster, an antibacterial agent, a deodorant, and a flame retardant.

According to the manufacturing method of the present embodiment, when making the slurry 26 a in the paper making process, water in the slurry is sucked and dewatered by the suction box 33. The inside of the recess 23 of the long-fiber non-woven fabric layer 20 can be easily filled with the cellulose-based fiber 26 as the suction and dewatering is stronger and the suction speed is higher. When the basis weight of the recess is low, the suction speed is relatively increased as compared with other high basis weight portions, and more cellulose fibers fill the recess. As described above, it is preferable that the paper making process includes a process of sucking and dewatering the water in the slurry 26 a added to the base sheet 20 a.
Moreover, when the suction | attraction force in suction spin-drying | dehydration is heightened, it is preferable at the point which can penetrate the base material sheet 20a (long fiber nonwoven fabric 21a) in the one part cellulose type fiber 26 in the slurry 26a.

  Next, a dewatering process of dewatering the formed sheet 10 obtained in the papermaking process will be described. The dewatering process may be performed until the water content (weight water content, the same applies hereinafter) becomes 70% or less from the point of maintaining the form of the molded sheet 10 (shape retention) and the point of maintaining mechanical strength. Preferably, dehydration is carried out to 60% or less. In the dewatering step in the present embodiment, dewatering is performed by passing the formed sheet 10 conveyed by the belt conveyor 37 a between the pair of press rolls 34 while pressing. Other than such a dewatering method, a method of dewatering by suction, a method of dewatering by blowing pressurized air, and the like can be mentioned.

  Next, the drying step will be described. In the present embodiment, when the formed sheet 10 conveyed by the belt conveyor 37 b contacts the surface of the Yankee dryer 35, the formed sheet 10 is dried. The drying method in the drying step can be appropriately selected according to the thickness and moisture content of the molded sheet 10 after dehydration, the moisture content after drying, and the like. Examples of the drying method include contact with a heating structure (heating element), spraying of heated air or steam (superheated steam), vacuum drying, electromagnetic wave heating, electric current heating, etc. Although dehydration and drying are performed separately, drying can also be performed simultaneously in combination with the aforementioned dehydration method. By drying the formed sheet 10 in this manner, the laminated sheet 1 can be obtained.

  The production method of the present invention may, if necessary, include a winding step of winding the laminated sheet 1 obtained after drying into a roll. Moreover, before winding up the lamination sheet 1 in roll shape, processings, such as a crepe process, a slit process, a trimming process, and a form change, can also be given with respect to the lamination sheet 1 as needed. In addition, the laminated sheet 1 may be pressed alone or superimposed on another sheet such as paper, cloth (woven fabric or non-woven fabric), film or the like, or may be pressed or embossed to perform embossing or needle punching. A plurality of sheets can be laminated and integrated, or uneven shaping and punching can be performed.

  Further, in the present embodiment, the transport paths of the long fiber non-woven fabric 21a, the slurry 26a and the laminated sheet 1 are constituted by the belt conveyors 37a and 37b and the winding roll 36. The conveyance path may be configured mainly by combining a winding roll, a belt conveyor, a vacuum conveyor, a roller conveyor and the like, and a conveyance means conventionally used for conveying a sheet member can be appropriately selected and used.

From the viewpoint of preventing the reduction of the permeability of the high-viscosity liquid by reducing the size of the fiber gap in the laminated sheet 1, the neck-in ratio obtained by the following formula (1) in the production method of the present invention is 20% or less Preferably it is 15% or less, More preferably, it is 10% or less. The neck-in ratio is a ratio (%) of the length of the laminated sheet 1 in the CD direction to the length of the base sheet 20a (long-fiber non-woven fabric 21a) in the CD direction, and is obtained by the following formula (1). The long-fiber non-woven fabric 21a is a long-fiber non-woven fabric 21a as a raw material to be subjected to the paper-making process. Moreover, CD direction is a direction orthogonal to the conveyance direction (MD direction) of the base material sheet 20a. The neck-in rate can be adjusted, for example, by the tension applied to the base sheet 20a. The tension can be lowered by adjusting the speed of each part related to the speed of the transport path such as the drive roll 38 and the winding roll 36 that rotates the belt conveyor. The lower the tension, the lower the neck-in rate.
Neck-in rate (%) = (W ₀ −W ₁ ) / W ₀ × 100 (1)
W ₀ : Length of base sheet 20 a (long-fiber non-woven fabric 21 a) in CD direction W ₁ : Length of laminated sheet 1 in CD direction

  As mentioned above, although the preferable embodiment of this invention was described, this invention is not restrict | limited to the embodiment mentioned above, A various change is possible in the range which does not deviate from the meaning of this invention.

The following lamination sheet, the manufacturing method of a lamination sheet, and an absorptive article are indicated about the embodiment mentioned above.
<1>
A laminate sheet having a long fiber non-woven fabric layer containing hydrophobic long fibers, and a cellulose-based fiber layer mainly composed of cellulose fibers, provided on one side or both sides of the long fiber non-woven fabric layer,
The long fiber non-woven fabric layer has a plurality of recesses and projections on the surface in contact with the cellulose fiber layer, and the cellulose fiber layer is laminated on the recesses.
The interface between the long fiber non-woven fabric layer and the cellulose fiber layer is in close contact with each other,
A laminated sheet having a ventilation resistance as the laminated sheet of 0.001 kPa · s / m or more and 0.08 kPa · s / m or less, preferably 0.05 kPa · s / m or less.

<2>
The laminated sheet according to <1>, wherein the long fibers have a contact angle with water of 90 degrees or more, and the cellulose-based fibers have a contact angle with water of less than 90 degrees.
<3>
In the long-fiber non-woven fabric layer constituting the long-fiber non-woven fabric layer, the blending ratio of the long fibers is preferably 50% or more, more preferably 70% or more, based on the weight of the long-fiber non-woven fabric. % Or less, more preferably 90% or less, preferably 50% or more and 98% or less, more preferably 70% or more and 90% or less, according to <1> or <2>.
<4>
In the state in which the interface between the long fiber non-woven fabric layer and the cellulose fiber layer is in close contact with each other, the adhesive does not substantially intervene at the interface between the two layers, and the long fiber and the cellulose fiber contact each other or The laminated sheet according to any one of <1> to <3>, which is in a state of being sufficiently adhered by entanglement.
<5>
The state in which the interface between the long fiber non-woven fabric layer and the cellulose fiber layer is in close contact means that the average of the gap distance in all the cut sections is 1/2 of the average thickness of the laminated sheet according to the following confirmation test. The lamination sheet in any one of said <1>-<4> which is a smaller state.
(Confirmation test of adhesion state)
It is confirmed by microscopic observation that no adhesive is present at the interface between the long fiber non-woven fabric layer and the two layers of the sheet having the cellulose-based fiber layer.
The sheet is cut into 5 cm squares and folded in two. The folded sheet is sandwiched between 10 cm square plates, a weight is placed, pressure is applied to 3 kPa, and the sheet is allowed to stand for 10 seconds to open the fold. This operation is repeated a total of three times so that the folding direction is the same, and the folds are also in the same position. Prepare another 5 cm square sheet creased by the above operation, immerse these sheets in liquid nitrogen for 10 seconds, and then use a sharp razor to cut the crease in the crease in the direction perpendicular to the crease. Put three places in each.
Next, the cut cross section of the cut in the sheet is observed using an SEM or an optical microscope to confirm the presence or absence of a gap between the long fiber nonwoven fabric layer and the cellulose fiber layer. When there is a gap, the gap distance in the thickness direction of the gap portion is measured, and the average of the gap distance in all the cut cross sections is determined. If the average of the gap distance is smaller than 1⁄2 of the average thickness of the laminated sheet, it is considered as “in close contact”, and if it is larger than 1⁄2 of the average thickness, “not in close contact” .
<6>
Any one of the above <1> to <5>, wherein a part of the cellulose-based fiber penetrates the long-fiber non-woven fabric layer and has a penetrating cellulose exposed on one side of the long-fiber non-woven fabric layer The laminated sheet described in.
<7>
The number per unit area (10 cm ² ) of the penetrating cellulose-based fiber in the long fiber non-woven fabric layer is preferably 3 or more and 300 or less, more preferably 10 or more and 100 or less, as described in the above <6> Laminated sheet.
<8>
The fiber roughness of the cellulose-based fiber is preferably 50 μg / m or more, more preferably 150 μg / m or more, and preferably 500 μg / m or less, and preferably 50 μg / m to 500 μg / m, more The laminated sheet according to any one of the above <1> to <7>, which is preferably 150 μg / m or more and 500 μg / m or less.

<9>
The average fiber length of the cellulose-based fiber is preferably 0.5 mm or more, more preferably 2 mm or more, preferably 10 mm or less, more preferably 5 mm or less, and preferably 0.5 mm to 10 mm or less The laminated sheet according to any one of <1> to <8>, which is preferably 2 mm or more and 5 mm or less.
<10>
The diameter of the cellulose fiber is preferably 1 μm or more, more preferably 10 μm or more, preferably 80 μm or less, more preferably 50 μm or less, and preferably 1 μm to 80 μm, more preferably 10 μm to 50 μm. The laminated sheet according to any one of the above <1> to <9>.
<11>
The bulk density of the cellulose-based fiber is preferably 0.01 g / cm ³ or more, more preferably 0.03 g / cm ³ or more, and preferably 0.5 g / cm ³ or less, more preferably 0.3 g / cm ^3. The above <1> to <cm ³ which is cm ³ or less, preferably 0.01 g / cm ³ or more and 0.5 g / cm ³ or less, more preferably 0.03 g / cm ³ or more and 0.3 g / cm ³ or less The laminated sheet as described in any one of 10>.
<12>
In the long-fiber non-woven fabric layer, the difference between the average height of the surface in contact with the cellulose-based fiber layer and the height of the long-fiber non-woven fabric layer in the recess or the protrusion is 2 of the average thickness of the long-fiber non-woven fabric layer The lamination sheet as described in any one of said <1>-<11> which does not exceed double.
<13>
The laminated sheet according to any one of <1> to <12>, wherein the concave portion and the convex portion of the long fiber non-woven fabric layer are formed by embossing.
<14>
The thickness of the long fiber nonwoven fabric layer in the recess is preferably 10% or more, more preferably 30% or more, and preferably 90% or less, with respect to the average thickness of the long fiber nonwoven fabric layer. Is 60% or less, preferably 10% or more and 90% or less, more preferably 30% or more and 60% or less, according to any one of <1> to <13>.
<15>
The area ratio of the recesses is preferably 3% or more, more preferably 5% or more, still more preferably 11% or more, and preferably 35% or less, more preferably 28% or less, more preferably 18% or less And also preferably 3% or more and 35% or less, more preferably 5% or more and 28% or less, still more preferably 11% or more and 18% or less, according to any one of the above <1> to <14> Sheet.
<16>
The basis weight of the long fiber non-woven fabric layer is preferably 5 g / m ² or more, more preferably 8 g / m ² or more, and preferably 15 g / m ² or less, more preferably 12 g / m ² or less The laminated sheet according to any one of <1> to <15>, which is preferably 5 g / m ² or more and 15 g / m ² or less, more preferably 8 g / m ² or more and 12 g / m ² or less.
<17>
The basis weight of the cellulose-based fiber layer is preferably 0.5 g / m ² or more, more preferably 1 g / m ² or more, and preferably 10 g / m ² or less, more preferably 6 g / m ² or less. And also preferably 0.5 g / m ² or more and 10 g / m ² or less, more preferably 1 g / m ² or more and 6 g / m ² or less, according to any one of the above <1> to <16> .

<18>
The content of the cellulose-based fiber in the cellulose-based fiber layer is preferably 50% or more, more preferably 70% or more, and preferably 98% or less, more preferably 92% or less, and preferably 50 % Or more and 98% or less, more preferably 70% or more and 92% or less, according to any one of <1> to <17>.
<19>
The diameter of the long fibers 21 is preferably 0.5 μm or more, more preferably 5 μm or more, preferably 50 μm or less, more preferably 30 μm or less, and preferably 0.5 μm to 50 μm or less, more preferably 5 μm The lamination sheet in any one of said <1>-<18> which is 30 micrometers or less.
<20>
The bulk density of the long fibers is preferably 0.01 g / cm ³ or more, more preferably 0.03.
g / cm ³ or more, preferably 0.2 g / cm ³ or less, more preferably 0.1 g / cm ³ or less, and preferably 0.01 g / cm ³ or more and 0.2 g / cm ³ or less The laminated sheet according to any one of <1> to <19>, which is more preferably 0.03 g / cm ³ or more and 0.1 g / cm ³ or less.
<21>
It is a manufacturing method of the lamination sheet in any one of said <1>-<20>, Comprising:
A sheet-forming step of supplying a slurry containing the cellulose-based fibers onto a base sheet made of the long-fiber non-woven fabric containing the hydrophobic long-fiber and forming the cellulose-based fiber layer on the base sheet by paper-forming A method of manufacturing a laminated sheet.
<22>
The manufacturing method of the lamination sheet as described in said <21> which makes the neck-in rate calculated | required by following formula (1) 20% or less, Preferably it is 15% or less, More preferably, it is 10% or less.
Neck-in rate (%) = (W ₀ −W ₁ ) / W ₀ × 100 (1)
W ₀ : length of the base sheet in a direction orthogonal to the transport direction of the base sheet W ₁ : length of the laminated sheet in the orthogonal direction <23>
Providing a slurry containing the cellulose-based fibers on a base material sheet made of a long-fiber non-woven fabric containing hydrophobic long-fibers, and forming a cellulose-based fiber layer on the substrate sheet by sheet-forming And
The manufacturing method of the lamination sheet which makes the neck-in rate calculated | required by following formula (1) 20% or less, Preferably it is 15% or less, More preferably, it is 10% or less.
Neck-in rate (%) = (W ₀ −W ₁ ) / W ₀ × 100 (1)
W ₀ : length of the base sheet in a direction orthogonal to the conveying direction of the base sheet W ₁ : length of the laminated sheet in the orthogonal direction <24>
The long-fiber non-woven fabric has a recess and a protrusion, and
The said recessed part and the said convex part are formed by making the basic weight of the long fiber in this recessed part low compared with this convex part, The lamination in any one of said <21>-<23> Sheet manufacturing method.
<25>
The recess and the protrusion of the long fiber non-woven fabric according to any one of <21> to <24>, which are mainly formed by the difference in basis weight when the long fiber non-woven fabric is produced. Method of manufacturing laminated sheet.

<26>
The method for producing a laminated sheet according to any one of <21> to <25>, wherein the concave portion and the convex portion of the long fiber non-woven fabric are formed by embossing with heat or pressure or ultrasonic waves.
<27>
The absorbent article which has a lamination sheet in any one of said <1>-<20>.
<28>
The absorbent article using the laminated sheet as described in any one of said <1>-<20> as a core wrap sheet which coats an absorptive core.
<29>
The absorbent article has an absorbent comprising the absorbent core and the laminated sheet covering the absorbent core, and a surface sheet disposed on the skin-facing side of the absorbent.
The absorption according to <28>, wherein the laminated sheet is disposed such that the surface sheet and the long-fiber non-woven fabric layer of the laminated sheet face each other between the surface sheet and the absorbent core. Sex goods.
<30>
The absorbent article according to any one of <27> to <29>, wherein the absorbent article is a disposable diaper.

  Hereinafter, the present invention will be more specifically described by way of examples, but the present invention is not limited to such examples. Unless otherwise stated, "%" means "mass%".

Example 1
The laminated sheet 1 was manufactured using a general-purpose wet paper machine. Specifically, one type of cellulose-based fiber (fiber concentration 0.1%) selected from cellulose-based fibers A to E shown in Table 1 below according to Table 2 below, and a wet paper strength agent (trade name “WS A slurry (stock) was prepared by uniformly dispersing -4030 ", manufactured by Hoshimitsu PMC Co., Ltd., 0.5% (against cellulose fiber) in water. The cellulose-based fiber was fibrillated by a beating machine and used as having a freeness of 650 ml. Next, a long fiber non-woven fabric having a width of 300 mm shown in Table 2 below is placed on a wire mesh papermaking wire with a wire opening diameter of 90 μm (166 mesh), the slurry is dispersed on the long fiber non-woven fabric, and a paper layer (fiber web (fiber web) Formed. The paper layer was sucked and dewatered at a rate of 6 ml / (cm ² · sec) using a suction box to obtain a formed sheet 10, and then pressure was applied using a press roll to dehydrate. After dewatering, the formed sheet was pressure-bonded to the surface of the Yankee dryer, and drying was performed to obtain a laminated sheet with a width of 260 mm. The paper making conditions were set to a paper making speed of 10 m / min. The neck-in rate of the laminated sheet obtained by the above manufacturing method was adjusted by the winding speed of the roll 36.

In the spunbond nonwoven fabric shown in Table 2 used as the long fiber nonwoven fabric, the spunbond layer made of polypropylene resin has a fiber diameter of 18 μm as a constituent fiber. The long-fiber non-woven fabric was embossed on the surface so as to have irregularities on the surface in contact with the cellulose-based fiber layer, and the area ratio of the recesses by embossing was 17.3% (oval pattern).
In Table 2, the basis weight (g / m ² ), bulk density (g / cm ³ ) of the long fiber non-woven fabric, and the thickness of the long fiber non-woven fabric layer in the recess relative to the average thickness (t1) of the long fiber non-woven fabric layer The ratio (t2 / t1) of (t2) is shown.

[Examples 2 to 14]
A laminated sheet 1 was produced in the same manner as in Example 1 except that the constitution (type, basis weight, bulk density) of the cellulose-based fiber and the long fiber non-woven fabric was changed as shown in Table 2 below.
In Examples 13 and 14, the SMS non-woven fabric used as the long fiber non-woven fabric is a polypropylene resin fiber having a fiber diameter of 20 μm and a constituent fiber of a meltblown layer having a fiber diameter of 1.8 μm. It was resin fiber. Moreover, the area ratio of the recessed part by embossing in the surface which touches the cellulose fiber layer of SMS nonwoven fabric was 20.9% (oval pattern). Further, in Examples 13 and 14, the suction dewatering of the paper layer was not performed.

[Comparative Examples 1, 2, 5 to 9]
Laminated sheet 1 in the same manner as in Example 1 except that the presence or absence of the cellulose fiber and the long fiber non-woven fabric, or the configuration (type, basis weight, bulk density) and neck-in ratio thereof are changed as shown in Table 3 below. Manufactured.
As the spunbond nonwoven fabric and the SMS nonwoven fabric used as the long fiber nonwoven fabric of each comparative example, those of the same constituent fibers as the above-described example were used respectively. Moreover, the spunbond nonwoven fabric and the SMS nonwoven fabric in each comparative example also have unevenness due to embossing on the surface in contact with the cellulose fiber layer, and the area ratio of the recesses of the spunbond nonwoven fabric and the SMS nonwoven fabric is 17.3. % And 20.9%.
In Comparative Examples 6 and 7, suction and dewatering of the paper layer was not performed. Thickness of long fiber non-woven fabric layer in the recess relative to basis weight (g / m ² ), bulk density (g / cm ³ ), and average thickness (t 1) of long fiber non-woven fabric layer used in each comparative example The ratio (t2 / t1) of (t2) is shown in Table 3.

Comparative Example 3
A dry sheet obtained by making a cellulose-based fiber A shown in Table 1 below at a basis weight shown in Table 3 below and a long-fiber non-woven fabric shown in Table 3 below were laminated to obtain a laminated sheet.

Comparative Example 4
A dry sheet obtained by forming a cellulose-based fiber E shown in Table 1 below with a basis weight shown in Table 3 below and a long-fiber non-woven fabric shown in Table 3 below are laminated and subjected to hydroentanglement treatment with a jet water stream to obtain a laminated sheet. Obtained.

The details of each cellulosic fiber in Table 1 below are as follows.
-Cellulosic fiber A: Softwood bleached kraft pulp (NBKP) (trade name "Caribbean", manufactured by Cariboo Pulp and Paper).
-Cellulosic fiber B: Softwood bleached kraft pulp (NBKP) (trade name "Arauco", manufactured by ARAUCO).
-Cellulose-based fiber C: Hardwood bleached kraft pulp (LBKP) (trade name "RIAU", manufactured by Riau Andalan).
-Cellulose-based fiber D: Mercerized pulp (trade name "POROSENIA", manufactured by ITT RAYONIER INC.).
-Cellulose-based fiber E: Cross-linked pulp (trade name "HBA", manufactured by Weyerhauser).

[Confirmation test of adhesion state]
About the lamination sheet of said each Example and comparative example, the presence or absence of the clearance gap between a long fiber nonwoven fabric layer and a cellulose fiber layer was confirmed by the confirmation test of the adhesion state mentioned above. And it showed in following Table 2 and Table 3 as a ratio [average gap distance / average thickness of lamination sheet x 100 (%)] of the gap distance to the average thickness of a lamination sheet. If the average of the gap distances in all the cut sections is smaller than 1/2 of the average thickness of the laminated sheet, that is, the above ratio is 50% or less, both layers are considered to be in a “contact state”.

[Confirmation test of penetrating cellulose fiber]
About the lamination sheet of each said Example and comparative example, the presence or absence of the penetration cellulose type fiber in a long fiber nonwoven fabric layer was confirmed by the following method. The long fiber non-woven fabric layer side of the laminated sheet was observed with a microscope at a magnification of 500 and the cellulose fiber was dyed using a 0.1% blue dye. This blue dye is obtained by diluting a commercially available synthetic dye (product name: Blue No. 1, Hodogaya Chemical Industry Co., Ltd.) to 0.1% with deionized water, and immersing the cellulose fiber layer in the 0.1% dye. And dried and adjusted. At this time, the cellulose fiber layer was carefully handled so as not to move or fall off. Ten 1 cm ² sections were randomly sampled from the stained laminated sheet. Next, a SEM image of the surface of the long fiber nonwoven fabric layer of each section was taken, and the number of cellulose fibers penetrating the long fiber nonwoven fabric layer was determined from the SEM image, and the results are shown in Table 2 and Table 3 below.

[Measurement of ventilation resistance and neck-in rate]
The air flow resistance and the neck-in ratio were measured by the method described above for the laminated sheet of each of the above Examples and Comparative Examples. The measurement results are shown in Tables 2 and 3.

[Preparation of Absorbent]
The absorber was produced using the lamination sheet of each said Example and comparative example. First, the disintegrated pulp fiber aggregate (pulp sheet having a basis weight of 250 g / m ² ) was coated with the laminated sheet of each of the above Examples and Comparative Examples, and this was used as an absorbent core. At the time of coating with the laminated sheet, the cellulose fiber layer 25 was coated so as to face the pulp fiber aggregate. Next, a surface sheet of a commercial disposable diaper “Mary's tape type S size (Kao Co., Ltd., manufactured and sold in Japan in 2015)” is solidified by cold spray to solidify and peel off a hot melt to bond between the materials, and laminated with the absorbent core. It was made to adhere using spray glue. After bonding, the mangle was pressed back and forth once to obtain an absorber.

[Evaluation of feces diffusion prevention property]
The stool diffusion prevention property was evaluated by the following method about the absorber produced using the lamination sheet of said each Example and comparative example. In the following method, the stool diffusion prevention property of the absorber is evaluated by the stool diffusion area, and it is judged that the smaller the value of the stool diffusion area is, the better the absorber has the liquid diffusion suppressing effect (feces diffusion prevention property) , Become highly rated.
First, 10 g of pseudo-soft stool was injected through a tube at the center of the skin facing surface side of the absorber. The components of the pseudo-soft stool are bentonite 22.5%, Poise 530 (40%, manufactured by Kao Corporation) 0.5%, Emulgen 130 K 0.03% aqueous solution (manufactured by Kao Corporation) 1.5%, ion-exchanged water 75 The viscosity was 40 mPa · s (23 ° C., vibration viscometer: SV-10, manufactured by A & D Co., Ltd.), and the surface tension was 55 mN / m. The artificial stool was allowed to stand for 30 seconds after injection, and filter paper and a weight (3.0 kPa) were placed thereon, and pressure was applied for 2 minutes. Then, the diffusion area of stool (feces diffusion area) was measured three times by image processing. The image processing was performed by photographing the diffused state of the stool with a digital camera and simultaneously capturing the image of a 10 cm square plate (100 cm ² ) photographed using the image analysis software (Adobe Photoshop CS5) on the front sheet The diffusion area was calculated by comparing the number of pixels of the portion where the artificial stool is diffused with the plate of which area is known. The average value of the measured values was taken as the measurement result and shown in Table 2 and Table 3.

Comparative Examples 2 and 5 to 9 where the ventilation resistance of the laminated sheet is not within the predetermined range, Comparative Example 1 containing no cellulose fiber, and the cellulose fiber layer are laminated in the form of a dry sheet to the long fiber nonwoven fabric layer The laminated sheets of Examples 1 to 14 in which the interface between the long-fiber non-woven fabric layer and the cellulose-based fiber layer are in close contact with each other as in Comparative Examples 3 and 4 in which the layer interface is not in a close contact state Because of this, when the artificial stool is injected, it permeates without spreading on the surface of the laminated sheet, and the feces diffusion area on the surface of the laminated sheet is small, that is, the liquid diffusion is suppressed. Among them, in Examples 8 to 10 using cellulose fibers having high fiber roughness, the effect of the suppression was remarkable.

DESCRIPTION OF SYMBOLS 1 laminated sheet 20 long fiber nonwoven fabric layer 21 long fiber 25 cellulose fiber layer 26 cellulose fiber 27 penetrating cellulose fiber 22 convex part 23 recessed part 24 gap 100 diaper 12 top sheet 13 back sheet 14 absorbent body 14 a absorbent core 14 b core wrap Sheet 3 wet paper machine 20a substrate sheet 31 papermaking net 33 suction box 34 press roll 35 yanky dryer 36 winding roll 10 formed sheet 37a, 37b belt conveyor

Claims (8)

A laminate sheet having a long fiber non-woven fabric layer containing hydrophobic long fibers, and a cellulose-based fiber layer mainly composed of cellulose fibers, provided on one side or both sides of the long fiber non-woven fabric layer,
The long fiber non-woven fabric layer has a plurality of recesses and projections on the surface in contact with the cellulose fiber layer, and the cellulose fiber layer is laminated on the recesses.
The interface between the long fiber non-woven fabric layer and the cellulose fiber layer is in close contact with each other,
A laminated sheet having a ventilation resistance as the laminated sheet of 0.001 kPa · s / m or more and 0.08 kPa · s / m or less.   The laminated sheet according to claim 1, wherein a part of the cellulose-based fiber penetrates the long-fiber non-woven fabric layer and is exposed on one side of the long-fiber non-woven fabric layer.   The laminated sheet according to claim 1, wherein the cellulose-based fiber comprises a fiber having a fiber roughness of 150 μg / m or more. The concave portion and the convex portion of the long fiber non-woven fabric layer are formed by embossing.
The laminated sheet according to any one of claims 1 to 3, wherein the thickness of the long fiber non-woven fabric layer in the recess is 90% or less with respect to the average thickness of the long fiber non-woven fabric layer. The basis weight of the long fiber non-woven fabric layer is 5 to 15 g / m ² ,
The basis weight of the cellulosic fiber layer is 0.5 to 10 g / ^{m 2,} laminated sheet according to any one of claims 1-4.   An absorbent article using the laminated sheet according to any one of claims 1 to 5 as a core wrap sheet for covering an absorbent core. It comprises a paper making process of supplying a slurry containing cellulosic fibers onto a base material sheet made of a long fiber non-woven fabric containing hydrophobic long fibers, and forming a cellulosic fiber layer on the base material sheet by paper forming;
The manufacturing method of a lamination sheet which makes the neck-in rate calculated | required by following formula (1) 20% or less.
Neck-in rate (%) = (W ₀ −W ₁ ) / W ₀ × 100 (1)
W ₀ : length of the base sheet in a direction orthogonal to the conveying direction of the base sheet W ₁ : length of the laminated sheet in the orthogonal direction It is a manufacturing method of the lamination sheet in any one of Claims 1-5,
Providing a slurry containing the cellulose-based fibers on a base material sheet made of a long-fiber non-woven fabric containing hydrophobic long-fibers, and forming a cellulose-based fiber layer on the substrate sheet by sheet-forming How to make a laminated sheet.