JP2019044294A - Non-woven fabric - Google Patents

Abstract

To provide a non-woven fabric that has a shielding property to shield a colored object such as excrement absorbed by an absorbent article and a visibility to enable visual confirmation that the colored object is pulled into the back and allows both properties to be expressed by changing the angle at which an observer looks.SOLUTION: Non-woven fabric has an area on one surface 10SA side of the non-woven fabric 10 where a shielding property exerted on a colored object 300 when viewed from above in vertical direction V is lower than that on the colored object 300 when viewed from above in oblique direction S.SELECTED DRAWING: Figure 1

Description

  The present invention relates to non-woven fabrics.

  BACKGROUND ART In absorbent articles such as sanitary napkins and diapers, techniques for imparting various functions to a surface material (also referred to as a surface sheet) that touches the skin are known.

  For example, the absorbent article described in Patent Document 1 has a top sheet provided with a ridge and a bottom between the ridges for the purpose of preventing skin sticking. There are a plurality of recesses on the top of the ridge, and a plurality of openings are arranged in the wall of the ridge. With regard to the top sheet made of a resin film, when the absorbent article is viewed from an oblique direction, it is supposed that the body fluid absorbed by the absorber can be seen through the opening.

JP, 2013-78362, A

In the absorbent article, the user can feel the absorbency and feel safe to use, because the dirt of excreted excrement (menstrual blood, urine, soft stool etc.) can not be seen from the skin side surface (high hiding power) ) Is one of the important conditions. On the other hand, it can be visually confirmed that excrement is drawn from the skin-side surface of the absorbent article into the depth and absorbed so that the user can feel a firm absorbency (the hiding power is low and visibility is low). It is desirable to have. In particular, when the difference in concealability is caused by changing the viewpoint, the user can effectively feel the absorbency of the absorbent article in the following use situations. That is, when the absorbent article after use is peeled off, it is possible to first realize the absorbency with no leakage when viewed from the front. It can then be lifted to evoke an impression that it is firmly absorbed from the surface to the back. It is desirable to realize such performance in a soft non-woven fabric that is preferably used for the surface sheet.
However, the hiding property to the colored matter such as dirt and the visibility for confirming that the colored matter is drawn firmly to the back are opposite properties, and it is easy for both to be firmly compatible in the non-woven fabric It was not. Providing the opening as in the resin film of Patent Document 1 is problematic in terms of strength in the case of a non-woven fabric composed of an assembly of fibers. In addition, when the nonwoven fabric is provided with an opening, there is a problem that liquid reversion may occur due to the hydrophilicity of the nonwoven fabric. Therefore, in the non-woven fabric, it is difficult to provide sufficient visibility to excrement by the opening.

  The present invention is provided with the hiding property to the colored matter such as the excrement absorbed in the absorbent article, and the visibility which can confirm that the colored matter is drawn into the back, and both properties are the viewing angle of the observer The invention relates to a non-woven fabric that can be developed by changing the

The present invention provides a region on one side of the non-woven fabric where the hiding property to the colored object when viewed from the upper side in the oblique direction is lower than the hiding property to the colored object when viewed from the upper side in the vertical direction. Provide a non-woven fabric.
In the present invention, the non-woven fabric has an uneven surface having a convex top, a concave bottom, and a wall connecting the convex top and the concave bottom on one side of the non-woven fabric, and the wall is the one side or the one side A non-woven fabric which extends in a direction perpendicular to the opposite surface, and in which the coating weight of the wall portion is smaller than the coating weight of the convex top portion and the concave bottom portion.

  The non-woven fabric of the present invention is provided with the hiding property to the colored matter such as the excrement absorbed in the absorbent article and the visibility which can confirm that the colored matter is drawn into the back, and both properties are the observer's It can be expressed by changing the viewing angle.

BRIEF DESCRIPTION OF THE DRAWINGS It is the perspective view which showed typically the state which mounted one preferable embodiment of the nonwoven fabric which concerns on this invention with the colored thing on the horizontal plane. It is the block diagram which showed the outline of the measuring method of secrecy. It is the fragmentary sectional view which showed typically another preferable embodiment of the nonwoven fabric concerning this invention. It is the fragmentary sectional view which showed typically another preferable embodiment of the nonwoven fabric concerning this invention. It is the fragmentary sectional view which showed typically another preferable embodiment of the nonwoven fabric concerning this invention. It is the partial cross section perspective view which showed typically another preferable embodiment of the nonwoven fabric concerning this invention. It is the II-II sectional view taken on the line of the nonwoven fabric shown in FIG. It is the III-III sectional view taken on the line of the nonwoven fabric shown in FIG. (A) A figure is a partially expanded sectional view showing an angle of a wall in a longitudinal section of Drawing 7, and a figure (B) shows the angle of a wall when a field of a wall is a concavo-convex field. (A) It is a partially expanded sectional view corresponding to a figure, (C) A figure is a partially expanded sectional view corresponding to the said (A) figure which shows the angle of the wall part in case a wall part is opening. It is. It is the front view which showed typically the fiber orientation of the wall part of the nonwoven fabric of this embodiment. It is a related figure of DTG / textiles input and temperature in the top, the bottom, and the wall of the nonwoven fabric of this embodiment. It is sectional drawing which showed typically an example of the preferable manufacturing method of the nonwoven fabric of this embodiment, (A) arrange | positions a fiber web on a support male material, and a support female material from the said fiber web. (B) is a cross-sectional view schematically showing the process of shaping the fiber web by pressing the first hot air from above the female support member. (C) is a cross-sectional view schematically showing a step of removing the female support member and blowing the second hot air from above the shaped fiber web to fuse the fibers together. BRIEF DESCRIPTION OF THE DRAWINGS It is drawing which showed the preferable example of the sanitary napkin which applied the nonwoven fabric of this invention to the surface sheet, (A) figure is a partial cutaway schematic perspective view, (B) figure was shown in (A) figure. It is an expansion part sectional perspective view in A part.

  A preferred embodiment of the non-woven fabric according to the present invention will be described below with reference to the drawings. However, the present invention is not construed as being limited thereby.

  As shown in FIG. 1, the nonwoven fabric 10 of the present embodiment has front and back surfaces. In the present embodiment, the front and back surfaces are described as one surface (first surface) 10SA and the other surface (second surface) 10SB opposite to the one surface 10SA. The thickness direction of the nonwoven fabric 10 is referred to as the Z direction, and the side of the first surface 10SA is also referred to as the first surface Z1 and the side of the second surface 10SA is also referred to as the second surface Z2. In the present embodiment, one surface (first surface) 10SA is shown as a surface (viewing surface) to be visually observed unless otherwise specified, but the non-woven fabric of the present invention is not limited thereto. Second surface) 10SB may be a surface to be viewed (observation surface).

  The non-woven fabric 10 is a colored object 300 when viewed from above in the oblique direction S with respect to the one surface 10SA side than the hiding property to the colored object 300 when viewed from above in the vertical direction V with respect to the one surface 10SA side. It has an area where the concealment against The "colored matter" referred to here means a colored matter which is shifted from the one surface 10SA side of the non-woven fabric to the other surface 10SB side. For example, it is a colored fluid such as menstrual blood, urine, and loose stools. Also, "colored" means both chromatic and achromatic.

  The angles of the "vertical direction V" and the "diagonal direction S" are basically determined with the non-woven fabric surface to be viewed as a reference (hereinafter also referred to as a reference surface). In the present embodiment, it is judged based on one surface 10SA of the nonwoven fabric 10. When the surface 10SA to be viewed is not flat but uneven, the non-woven fabric 10 in contact with the flat surface 10P with the other surface 10SB facing down on the horizontal flat surface 10P, ie, the non-woven fabric surface The other surface 10SB can also be determined as a reference surface. In this case, the flat surface 10P and the other surface 10SB of the non-woven fabric surface are substantially the same surface. Therefore, when the other surface 10SB is an uneven surface, the plane 10P may be used as a reference surface. In the present embodiment, as shown in FIG. 1, the flat surface 10P is a non-woven fabric reference surface 10SS (hereinafter simply referred to as a reference surface 10SS) with the non-woven fabric 10 placed on the horizontal flat surface 10P with the other surface 10SB down. It is judged as).

The “vertical direction V” is an angle α that is greater than 80 ° and less than 100 ° with respect to the reference surface 10SS described above, and means a direction away from one surface 10SA. The angle α with respect to the reference surface 10SS is preferably 85 ° or more and 95 ° or less, more preferably 89 ° or more and 91 ° or less, and particularly preferably 90 °. “Viewing from above in the vertical direction V” refers to viewing at one surface 10SA along the vertical direction V from a position separated upward from the one surface 10SA at an angle α (hereinafter referred to as This viewing position is called a vertical viewpoint.)
The “oblique direction S” is an angle β of 30 ° or more and 80 ° or less with respect to the reference surface 10SS described above, and means a direction away from one surface 10SA. The angle β with respect to the reference surface 10SS is preferably 30 ° to 70 °, more preferably 50 ° to 65 °, and still more preferably 50 ° to 60 °. “Viewing from above in the oblique direction S” means viewing on one side 10SA along the oblique direction S from a position separated upward from the one side 10SA at an angle β (hereinafter referred to as This viewing position is called a diagonal viewpoint.)
“The concealability with respect to colored objects when viewed from above obliquely becomes low” means that at least one point in the range of the above-mentioned oblique direction S (for example, 30 ° or more and 80 ° or less with respect to the reference surface 10SS) It is said that the hiding power to the colored thing becomes low when it is done.

  The above-mentioned "masking property" indicates how difficult it is to recognize the presence of the colored object 300 below the one surface 10SA when the nonwoven fabric 10 is viewed with the one surface 10SA at the top. The “obscurity” is determined by the color difference between the vertical viewpoint and the oblique viewpoint through the fiber layer of the non-woven fabric 10. From the viewpoint of making the difference in the degree of concealment to the colored material 300 clearer, it is preferable that the non-woven fabric 10 be composed entirely of a single-colored fiber layer, and more preferably be composed of a white fiber layer. In the present embodiment, the non-woven fabric 10 will be described below as being constituted by a white fiber layer.

  This color difference is obtained by the difference in the degree of transmission of light traveling from the one surface 10SA side to the other surface 10SB side of the non-woven fabric 10. That is, the fact that “the hiding power” is lower in the oblique viewpoint than in the vertical viewpoint means that the degree of transmission of light through the fiber layer is high in the oblique viewpoint. The nonwoven fabric 10 may or may not have an opening, which contributes to the performance of the nonwoven fabric 10 according to the “masking property”. That is, it is preferable that the non-woven fabric 10 does not have an opening from the viewpoint of suppressing the return of the colored material 300 which has shifted to the lower side of the non-woven fabric 10 (the second surface side Z2). In this way, it is possible to suppress that the hiding property (the hiding property to the stain due to the excrement) necessary for the non-woven fabric 10 is reduced by the return of the colored product 300. Moreover, the strength reduction of the nonwoven fabric 10 by an opening part can be avoided. By maintaining the strength of the non-woven fabric in this manner, the compatibility between the hiding property to the colored material 300 and the visibility capable of recognizing that the colored material 300 is drawn back is long even though the use time of the non-woven fabric is extended. Become sustainable.

(Method of measuring concealment)
The concealability indicated by the color difference is measured by the following method, since the completely concealed state is white (reference value L93: a128: b128), and the concealability becomes higher when closer to white (FIG. 2). reference).
(1) The measurement surface (one surface 10SA) of the non-woven fabric 10 faces upward and the surface facing the lower side (the other surface 10SB) is a red standard plate (hereinafter referred to as a standard plate) manufactured by Nippon Denshoku Kogyo Co., Ltd. Put.) 210.
(2) The measurement position M1 is determined with respect to the measurement surface of the nonwoven fabric 10, and the vertical direction V (angle α) at the measurement position M1 is determined using an angle meter. The standard plate 210 is imaged along with the image correction color chart 230 through the non-woven fabric 10 from the position 20 cm above the measurement position M1 in the vertical direction V using the imaging device 220 (hereinafter, this imaged image is also referred to as a vertical viewpoint image. ). The measurement surface (one surface 10SA) including the measurement position M1 is the uppermost surface of the nonwoven fabric 10 and is set parallel to the nonwoven fabric reference surface 10SS.
(3) At the measurement position M1 of the measurement surface of the non-woven fabric 10, the oblique direction S (angle β) is determined using an angle meter. The standard plate 210 is imaged along with the image correction color chart 230 through the non-woven fabric 10 from the position 20 cm above the oblique direction S of the measurement position M1 (hereinafter, this imaged image is also referred to as an oblique viewpoint image. ).
(4) The image processing for uniform correction of the color information level is performed using the image correction color chart in which the image taken from above in the vertical direction and the image taken from above in the oblique direction are embedded in the image. Next, based on the image data subjected to image processing, the color difference ΔE ^* _ab from the reference value (white) is determined based on the following formula (A1).
ΔE ^* _ab = [(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* ) ² ] ^1/2 (A1)
(In the formula, L ^* represents lightness, and a ^* and b ^* represent chromaticity. ΔL ^* , Δa ^* and Δb ^* are white reference values and an image taken from above the nonwoven fabric 10 in the vertical direction, nonwoven fabric Indicates the difference with the image taken from above 10 diagonally.)
The ΔE ^* _{ab of} the image captured from above the non-woven fabric 10 in the vertical direction represents the hiding ratio E _α to the colored object 300 when viewed from above in the vertical direction. Delta] E ^* _ab of an image captured from an oblique direction upward of the nonwoven fabric 10 represents the contrast ratio E _beta for colored product 300 in the case of viewing from an oblique direction upward. The concealment rates E _α and E _β are both closer to white at lower values, indicating that the concealability is high. Here, when the difference in the concealment rate is less than 0.5, based on JIS L 0804 and JIS L 0805, the color difference can not be determined by humans. That is, when there is a difference of 0.5 or more, human beings can recognize the difference in concealment rate. The difference between the concealment rate E _{β and} the concealment rate E _α (E _β −E _α ) is taken as the difference between the concealment rates.

The above measurement method is performed in more detail as follows.
The angle α in the vertical direction V shown in the above (2) is 90 °, and an image of the vertical viewpoint is captured together with the image correction color chart 230. The angle β in the oblique direction S shown in the above (3) changes the angle to a predetermined interval in the range of 30 ° to 80 °, and images of the oblique viewpoints are taken. For example, with the measurement position M1 as the fulcrum from the vertical direction V, the image of the oblique view is captured along with the image correction color chart 230 at a position where the optical axis L1 of the imaging device 220 is inclined 10 ° from 30 ° to 80 °. Do. The position of 100 ° is substantially the same as the position of 80 °. For the angle meter, for example, a blueslant dial type product number 78544 (trade name) manufactured by Shinwa Measurement Co., Ltd. can be used. In (2) and (3) of the above measurement method, the imaging position is a distance of 20 cm from the surface of the non-woven fabric to the outermost surface of the lens of the imaging device, and the optical axis of the lens of the imaging device faces the imaging position M1 from the imaging position To be
As the imaging device 220, digital camera PowerShot S120 (trade name) manufactured by Canon Inc. can be used. For example, CASMATCH (trade name: manufactured by Bear Medic Co., Ltd.) can be used for the color chart 230 for image correction. Moreover, it is preferable to illuminate from the direction of 200 cm perpendicular | vertical direction with respect to an imaging region using the daylight white light bulb made into natural light white close | similar to sunlight with a color temperature of about 5000K for illumination at the time of photography. It is preferable not to use the flash of the camera so that light other than the light source does not enter during shooting.

As the image processing shown in the above (4), a color chart for image correction is used. Then, according to Kano, K. (1999) “Utilization of digital images and their color processing at the forefront of medical care: From the area of the otorhinolaryngology,” “The 1st Symposium on" Colors of Digital Medical Images: Panel Discussion, Part 2 " Make corrections. Open the image to be processed with the image processing software under the trade name Adobe Photoshop CSS version 12.0 (Adobe) and set the channel to the RGB channel. The color picker corrects the color information level of the white area of CASMATCH to white (R [228], G [228], B [228]). Similarly, the gray area of CASMATCH is corrected to gray (R [114], G [114], B [114]) and the color information level is corrected, and the black area of CASMATCH is black (R [35], G [35] , B [35]) to correct the color information level.
Next, for the image of the vertical viewpoint and the image of the oblique viewpoint, the image after correction is set to the _Lab channel, the region equivalent to the red region of the standard plate 210 of the image is selected, and the histogram is confirmed. Then, three-dimensional orthogonal coordinates (L ^* , a ^* , b ^* ) of the CIE 1976 L ^* a ^* b ^* color space (CIELAB color space) described later are obtained.

The CIE 1976 L ^* a ^* b ^* color space (CIELAB color space) indicates a uniform perceptual color space by three-dimensional orthogonal coordinates (L ^* , a ^* , b ^* ). L ^* , a ^* and b ^* are defined by the following formulas (B1), (B2) and (B3) according to JIS Z 8720: 2012 Standard Illuminant (Standard Light) and Standard Light Source for Colorimetry.
L ^* = 116 × (Y / Y _n ) ^1/3 −16 (B1)
a ^* = 500 * [(X / X _n ) ¹ /3-(Y / Y _n ) ^1/3 ] (B2)
b ^* = 200 * [(Y / Y _n ) ¹ / ^3- (Z / Z _n ) ^1/3 ] (B3)
X _n , Y _n and Z _n are tristimulus values of the illumination light source.
In the case of standard light C (2 ° field of view XYZ system)
Y _n = 100, X _n = 98.072, Z _n = 118.225
In the case of standard light D ₆₅ (2 ° field of view XYZ system)
Y _n = 100, X _n = 95.045, Z _n = 108.892
However, this applies in the case of X / X _n 0.000.008856, Y / Y _n 0.000.008856, and Z / Z _n 0.000.008856.

Next, based on the calculated three-dimensional orthogonal coordinates (L ^* , a ^* , b ^* ), the color difference between the image of the vertical viewpoint or the image of the oblique viewpoint and the reference value that is white is expressed by the equation (A1). Calculated by).

When the value of the concealment rate E _β is larger than the concealment rate E _{α and} the difference in the concealment rate (E _β −E _α ) is 0.5 or more, the concealment to the colored object 300 when viewed from above the vertical direction V It is determined that the concealability with respect to the colored object 300 when viewed from above the oblique direction S is lower than the sex. The difference in concealment rate is preferably 1 or more, more preferably 1.5 or more.
In addition, when the difference in concealment rate is −0.5 or less, the concealability with respect to the colored object 300 when viewed from the upper side in the oblique direction S is better than the concealability with respect to the colored object 300 when viewed from above the vertical direction V. It is judged to be high. In addition, when the difference in concealment rate is smaller than 0.5 and larger than -0.5, the concealability to the colored object 300 when viewed from above the vertical direction V and the colored object when viewed from above the diagonal direction S It is judged that the concealment to 300 is equivalent.

  Next, in the non-woven fabric 10, a preferred embodiment will be described in which the hiding power of the oblique viewpoint is lower than the hiding power of the vertical viewpoint.

  The non-woven fabric 10 may have various shapes as long as it has different concealability depending on the angle of visual observation. For example, one surface 10SA may be flat or uneven. Hereinafter, non-woven fabrics 10A to 10D will be described as preferred embodiments of the non-woven fabric 10. However, the nonwoven fabric of the present invention is not limited to these embodiments.

FIG. 3 shows a nonwoven fabric 10 (10A) of a preferred embodiment. In the nonwoven fabric 10A, one surface 10SA side and the other surface side SB are flat.
The nonwoven fabric 10A is composed of three fiber layers in the thickness direction. A layer in which semidal layers 22 and fulldal layers 23 composed of fulldal fibers are alternately arranged in a plane direction is provided on one surface 10SA side and the other surface 10SB side with the semidal layers 21 composed of semidal fibers interposed. In the present embodiment, a layer formed of the semi-dual layer 22 and the full-dual layer 23 on the side of one surface 10 SA is referred to as a first surface layer 24. A layer composed of the semi-dual layer 22 and the full-dual layer 23 on the other surface 10 B side is referred to as a second surface layer 25. In addition, the middle semidal layer 21 is also referred to as an intermediate layer 21. The fludal layer 23 composed of fludal fibers has a lower light transmittance than the semidal layers 21 and 22 composed of semidal fibers, and has high hiding power to colored materials.

  The above-mentioned "semi-dal" is a fiber having a little gloss, and is a fiber having a mass of the color tone changing material per unit mass of fiber of less than 1% by mass, or a fiber satisfying one of the conditions. “Fuldal” is a fiber having no gloss at all, and a mass of the color tone changing material per fiber unit mass is 1% by mass or more, or a fiber satisfying one of the conditions. The measurement method of gloss is measured according to JIS L 1013: 2010 chemical fiber filament yarn test method, 8.24 glossiness. JIS L 1013: 2010 Chemical fiber filament yarn test method and 8.25 ash content measurement method are used to judge “Semidal” and “Fuldal” based on the content of the color-change material. The ash content per fiber unit mass can be determined by this measurement method, and the ash content per fiber unit mass can be determined as the content of the color tone changing material.

As shown in FIG. 3, the non-woven fabric 10A is arranged such that layers of the same type do not overlap on one surface 10SA side and the other surface 10SB side. That is, the full dual layer 23 is disposed at the corresponding position of the second surface layer 25 with respect to the semi dual layer 22 of the first surface layer 24, and the full dual layer 23 of the first surface layer 24 is A semidal layer 22 is disposed at the corresponding position. Thereby, when viewed from above in the vertical direction from one side 10SA side (or the other side 10SB side) in the nonwoven fabric 10A, the vertical direction is made vertical by the full surface layer 23 of the first surface layer 24 and the full surface layer 23 of the second surface layer 25. Transmission of light in the direction is blocked, resulting in high concealability.
On the other hand, light is easily transmitted through the semi-dual layer 22 of the first surface layer 24, the intermediate semi-dual layer 21 and the semi-dual layer 22 of the second surface layer 25 when viewed from above obliquely. In this oblique direction, the concealability is lower than in the vertical direction.
That is, in the stacked region of the first surface layer 24, the intermediate layer 21 and the second surface layer 25, the hiding property to colored objects (see FIG. 1) when viewed from the vertical viewpoint on one surface 10SA side is more The concealment to colored objects when viewed from an oblique viewpoint is low. Thereby, in the non-woven fabric 10A, the hiding property to the colored material and the visibility capable of recognizing that the colored material is drawn back are compatible.

FIG. 4 shows the nonwoven fabric 10 (10B) of another preferred embodiment. The nonwoven fabric 10B is a nonwoven fabric in which one surface 10SA side and the other surface side SB are uneven.
The nonwoven fabric 10B is an embodiment in which the semi-dual layer 22 is not present in the first surface layer 24 and the second surface layer 25 in the laminated structure of the nonwoven fabric 10A described above. That is, the first surface layer 24 and the second surface layer 25 in which the uneven surface is formed by disposing the full dal layer 23 on the one side 10SA side and the other side 10SB side with the semi-dal layer 21 as the intermediate layer interposed therebetween Have. In each of the first surface layer 24 and the second surface layer 25, there is a recess 26 in which no fiber is disposed between the full dull layers 23. That is, the full dull layer 23 becomes the convex portion 23, and the convex portion 23 and the concave portion 26 are alternately arranged. Thereby, both surfaces 10SA and 10SB of the nonwoven fabric 10B are uneven surfaces. The convex portion 23 has a convex top portion 23A made of fibers of a full dull layer, and the concave portion 26 has a concave bottom portion 26A made of fibers of a semi-dull layer. Moreover, the convex part 23 has the wall part 3 which consists of the fiber of the full dal layer which connects the convex top part 23A and the concave bottom part 26A.

In the non-woven fabric 10B, at the bottom of the recess 26, the full layer 21, which is an intermediate layer, is exposed. Further, in the first surface layer 24 and the second surface layer 25, the full dull layers 23 do not overlap with each other. Thereby, the transmission of light in the vertical direction is blocked by the full dull layer 23 of the first surface layer 24 and the full dull layer 23 of the second surface layer 25. Therefore, the concealability when viewed from the vertical viewpoint is high. On the other hand, when viewed from an oblique viewpoint, light is easily transmitted through the intermediate semi-dull layer 21 exposed at the position of the recess 26 of the first surface layer 24 and the recess of the second surface layer 25. In this oblique direction, the concealability is lower than in the vertical direction.
That is, in the stacked region of the first surface layer 24, the intermediate layer 21 and the second surface layer 25, the hiding property to colored objects (see FIG. 1) when viewed from the vertical viewpoint on one surface 10SA side is more The concealment to colored objects when viewed from an oblique viewpoint is low. Thereby, in the non-woven fabric 10B, the hiding property to the colored material and the visibility capable of recognizing that the colored material is drawn back are compatible.

  In the nonwoven fabrics 10A (FIG. 3) and 10B (FIG. 4), the lamination region of the first surface layer 24, the intermediate layer 21 and the second surface layer 25 may be all or part of the nonwoven fabric 10A. Good. When in part, it is preferable that the laminated area be at least a liquid receiving area directly receiving liquid. For example, in the absorbent article, it is preferable to be in the region corresponding to the excretory part of the wearer.

  Further, in the first surface layer 24 and the second surface layer 25 of the nonwoven fabric 10A, the direction of alternately arranging the semi-dual layer 22 and the full-dual layer 23 can be set as appropriate. For example, the alternating arrangement may be disposed along the longitudinal direction of the non-woven fabric (machine direction at the time of manufacture (MD; Machine Direction)). It may be disposed along a width direction orthogonal to the longitudinal direction (direction orthogonal to the machine flow direction at the time of manufacture (CD; Cross Direction)). In addition, the extension length of each of the semi-dual layer 22 and the full-dual layer 23 may extend over the entire length in the width direction or the longitudinal direction of the non-woven fabric, or may be shorter than the entire length. When the extension length of each of the semidal layer 22 and the fulldal layer 23 is shortened, the semidal layer 22 and the fulldal layer 23 may be alternately arranged along the extension direction. That is, the semi-dual layer 22 and the full-dual layer 23 may be alternately arranged in a lattice pattern along both the longitudinal direction and the width direction of the non-woven fabric. Also, they may be arranged regularly along both the longitudinal direction and the width direction, and the arrangement period may change along the one or both of the longitudinal direction and the width direction, and they may be arranged irregularly. It may be done. The pattern formed by the semi-dual layer 22 and the full-dual layer 23 may be arranged to be visible on the surface of the non-woven fabric 10A. Thereby, in the nonwoven fabric 10A, a design can be visually recognized.

  In the first surface layer 24 and the second surface layer 25 of the non-woven fabric 10B, the direction of alternately arranging the full dal layer (convex portion) 23 and the recess 26 can be appropriately set similarly to the non-woven fabric 10A. Similarly to the nonwoven fabric 10A, the extension length of the full dal layer (convex portion) 23 and the recess 26 can be set as appropriate. The protrusions 23 and the recesses 26 may be alternately arranged in a lattice pattern along both the longitudinal direction and the width direction of the nonwoven fabric. Also, they may be regularly arranged along both the longitudinal direction and the width direction, and the arrangement period may change halfway along either or both of the longitudinal direction and the width direction, and irregularly arranged It may be done. The non-woven fabric 10B may be arranged such that the pattern formed by the projections 22 and the recesses 26 can be seen on the surface of the non-woven fabric 10B. Thereby, a design can be visually recognized in nonwoven fabric 10B.

Although one embodiment of the nonwoven fabric 10A (FIG. 3) can be manufactured as follows, the manufacturing method is not limited thereto.
First, the non-woven fabric 10A is a web or non-woven fabric made of semi-dual fibers (hereinafter referred to as first semi-dough material, second semi-duck material), and a web or non-woven fabric made of full-dual fibers (hereinafter referred to as full-dual material). prepare.
Next, the first semi-dull material and the full-dull material are slit in the MD direction. The slitted first semidal material and the slitted fulldal material are alternately arranged and stacked on the surface of the second semidal material. A slitted first semi-dough material and a full-dual material are alternately arranged and stacked on the back surface of the first semi-duck material opposite to the surface. At that time, the non-woven fabric 10A is manufactured by alternately laminating layers alternately on the surface in the order of lamination and alternately bonding them.
As a result, as shown in FIG. 3, the semidal layer 22 made of the first semidal material and the fulldal layer 23 made of the fullal material face each other with the intermediate layer (semidal layer) 21 made of the second semidal material interposed therebetween. Be done.
As another method, a semi-dough fiber is used to form an uneven semi-duck material having an uneven surface by various methods usually used for shaping of non-woven fabric. Then, the full dull material may be laminated on the concave part of the uneven semi-dull material and appropriately joined to manufacture the non-woven fabric 10A.

Although one embodiment of nonwoven fabric 10B (FIG. 4) can be manufactured as follows, a manufacturing method is not limited to this.
The non-woven fabric 10B prepares a web or non-woven fabric (hereinafter referred to as "semi-dull material") made of semi-dal fibers and a web or non-woven fabric (hereinafter referred to as "full-dully material") made of full-dull fibers.
Slit the full ful material in the MD direction. The non-woven fabric 10B is manufactured by alternately arranging and stacking slit full-rudder materials on the surface of the semi-dall material and the back surface opposite to the surface so as to be uneven.
As a result, as shown in FIG. 4, in each of the first surface layer 24 and the second surface layer 25 located on both sides of the middle layer (semi-duck layer) 21 made of the semi-dall material, convex portions (fed-dall layer) And 23) and the recesses 26 between the protrusions where no full bulging material is disposed.
Moreover, the uneven surface in the nonwoven fabric 10B can also be further added to form unevenness by various methods usually used for shaping of the nonwoven fabric.

FIG. 5 shows yet another preferred embodiment non-woven fabric 10 (10C). In the nonwoven fabric 10C, one surface 10SA side is an uneven surface, and the other surface 10SB side is a flat surface.
The uneven surface of the nonwoven fabric 10C is formed by alternately arranging the convex portions 28 and the concave portions 29. On the uneven surface, a wall portion 3 is further provided which connects a top 28A (hereinafter referred to as a convex top 28A) of the projection 28 and a bottom 29A (hereinafter referred to as a depressed bottom 29A) of the recess 29. The convex top portion 28A, the concave bottom portion 29A, and the wall portion 3 are exposed to the one surface 10SA side to form the uneven surface.
In the nonwoven fabric 10C, the color tone changing material 6 is disposed on the convex top portion 28A and the concave bottom portion 29A. On the other hand, in the wall portion 3, the content of the color tone changing material 6 is smaller than that of the convex top portion 28A and the concave bottom portion 29A. In FIG. 5, the wall portion 3 is shown as an aspect in which the color tone changing material 6 is not contained.
The measuring method of content of the color tone change material 6 can be calculated | required by the JIS L 1013: 2010 chemical fiber filament yarn test method and the measuring method of 8.25 ash content. Alternatively, when the color tone change material 6 is titanium oxide, it is determined by various measurement methods such as JIS L 1013: 2010 chemical fiber filament yarn test method, 8.26 titanium oxide measurement method, heat catalyst activity amount estimation method, etc. be able to. The estimation method by the thermal catalyst activity amount can be measured from the thermal catalyst activity amount of the color tone change material by the differential thermal-thermogravimetric simultaneous measurement (TG-DTA) method. And the mass change rate: DTG (Derivative Thermogravimetry) [μg / min] divided by the fiber input amount DTG / fiber input amount [% / min] corresponds to the content of the color tone change material in the fiber [wt%] Can be used as an estimate. In addition, this differential thermal-thermogravimetric simultaneous measurement (TG-DTA) is performed based on JISK0129.

The above-mentioned "color tone changing material" refers to a material having an effect of reducing the light transmittance of light incident on the non-woven fabric and scattering the light. For example, an inorganic powder, an organic powder, etc. from which a refractive index differs with the component of the constituent fiber of a nonwoven fabric are mentioned.
Examples of the inorganic powder include titanium oxide, porous silicon oxide (silica), porous silica, aluminum oxide (alumina), lime, and clay minerals. Examples of the clay mineral include smectite, montmorillonite, bentonite, kaolinite, sericite, illite, gluconite, chlorite, zeolite, talc, and miskanite.
Examples of the organic powder include polyethylene powder, polyester powder, polypropylene powder, polyacrylic powder, polyacrylate powder, cellulose powder, viscose powder, silk powder, silicone compound powder, fluorine compound powder, and the like. Moreover, what colored these organic powders with pigment | dye is mentioned.

In the non-woven fabric 10C, the color tone changing material 6 is disposed on the surfaces of the convex top portion 28A and the concave bottom portion 29A.
Such an arrangement can be performed by a coating process on the surfaces of the convex portion 28A and the concave bottom portion 29A. The coating treatment can be performed by a commonly used method. For example, printing and coating processes such as letterpress printing, intaglio printing, lithographic printing, and stencil printing, spray coating processes, and inkjet coating processes can be mentioned. As a method of making the content of the color tone changing material of the wall 3 smaller than that of the convex top 28A and the concave bottom 29A, the phases of the concavities and convexities of the convex top 28A and the concave bottom 29A are matched and coated on the convex top 28A and the concave bottom 29A. The method of processing is mentioned. Further, a method of applying a coating containing a large amount of color tone changing material to the convex top portion 28A and the concave bottom portion 29A using electrostatic induction, a method of applying a coating treatment by masking the wall portion 3 and the like can be mentioned.

In the non-woven fabric 10C, since the color tone changing material 6 is disposed on the surfaces of the convex portion 28A and the concave bottom portion 29A, transmission of light in the vertical direction with respect to one surface 10SA is blocked. Therefore, the concealability when viewed from above in the vertical direction is high. On the other hand, when viewed from above in the oblique direction, the light transmittance of the wall 3 is better than that of the convex apex 28A and the concave bottom 29A. In this oblique direction, the concealability is lower than in the vertical direction.
That is, in the region of the uneven surface, when viewed from above in the oblique direction with respect to the wall portion 3 as compared with the concealing property with respect to colored objects (see FIG. 1) when viewed from above vertically with respect to the convex top 28A and the concave bottom 29A. The concealment to colored objects is reduced. Thereby, in the non-woven fabric 10C, the hiding property to the colored material and the visibility capable of recognizing that the colored material is drawn back are compatible.

  The difference (C1-C2) between the content (C1) of the color tone changing material 6 in each of the convex top portion 28A and the concave bottom portion 29A and the content (C2) of the color tone changing material 6 in the wall portion 3 is in the following range preferable. From the viewpoint of exerting the above-mentioned effects of concealability and visibility effectively, the difference (C1-C2) is preferably 0.1% by mass or more, and more preferably 0.3% by mass or more. Moreover, from a viewpoint of suppressing the color nonuniformity of the whole nonwoven fabric, 10 mass% or less is preferable, as for a difference (C1-C2), 5 mass% or less is more preferable, and 3 mass% or less is still more preferable.

  The content (C1) of the color tone changing material 6 in each of the convex top portion 28A and the concave bottom portion 29A is more than 0 (zero) mass%, and 0.15 mass% from the viewpoint of realizing high "masking" in the vertical viewpoint. The above is more preferable, and 3% by mass or more is more preferable. The content (C1) is preferably 20% by mass or less, more preferably 10% by mass or less, and 5% by mass, from the viewpoint of favorably maintaining fiber moldability, fiber processability, nonwoven fabric formability, and nonwoven fabric processability. The following are more preferable.

  The content (C2) of the color tone changing material 6 in the wall portion 3 is preferably 10% by mass or less, more preferably 5% by mass or less, and 3% by mass from the viewpoint of sufficiently reducing the "masking property" in the oblique viewpoint. More preferable. The content (C2) is preferably 0 (zero) mass% or more, more preferably 0.1 mass% or more, and still more preferably 0.15 mass% or more, from the viewpoint of enhancing the hiding property of the whole nonwoven fabric.

  In the nonwoven fabric 10C, the arrangement direction and the arrangement area of the uneven surface can be set as appropriate similarly to the nonwoven fabric 10B. Moreover, the uneven surface in the nonwoven fabric 10C can be formed by various methods generally used for shaping of the nonwoven fabric.

  Next, still another preferred embodiment of the nonwoven fabric 10 will be described with reference to FIGS.

FIG. 6 shows a nonwoven fabric 10 (10D) having an uneven surface.
The nonwoven fabric 10D has the uneven surface 8 on the first surface side Z1 which is one surface side, and the uneven surface 9 on the second surface side Z2 which is the other surface side opposite to the first surface side Z1. . The uneven surface 8 has a recess 81 and a protrusion 82 as viewed from the first surface Z1 side. Further, the uneven surface 9 has a concave portion 91 and a convex portion 92 as viewed from the second surface side Z2 side. Here, the concave portion 81 and the convex portion 92 are in the relation of front and back, and the concave portion 91 and the convex portion 82 are in the relation of front and back.

As shown in FIGS. 7 and 8, the uneven surface 8 and the uneven surface 9 have the following configuration.
The uneven surface 8 is a wall portion 3 connecting the bottom 81B of the recess 81 (hereinafter, also referred to as a concave bottom 81B), the top 82T of the projection 82 (hereinafter, also referred to as a projection 82T), and the projection 82T and the depression bottom 81B. Equipped with The concave bottom portion 81B is configured of the outer surface fiber layer 2 which is a flat surface of the second surface side Z2. The convex top portion 82T is configured of the outer surface fiber layer 1 which forms a flat surface of Z1 on the first surface side. The wall portion 3 is a common wall which forms the side surface portions of the concave portion 81 and the convex portion 82 and which divides the concave portion 81 and the convex portion 82.
The uneven surface 9 is a wall portion 3 connecting a bottom portion 91B of the concave portion 91 (hereinafter, also referred to as a concave bottom portion 91B), a top portion 92T of the convex portion 92 (hereinafter, also referred to as a convex portion 92T), and a convex portion 92T and the concave bottom portion 91B. Equipped with The concave bottom portion 91B is configured of the outer surface fiber layer 1 which is a flat surface of the first surface side Z1. The convex top portion 92T is configured of the outer surface fiber layer 2 forming a flat surface on the second surface side Z2. The wall 3 is a side wall of the recess 91 and the protrusion 92 and is a common wall of the recess 91 and the protrusion 92.
The top 82T and the bottom 91B are formed of the common outer surface fiber layer 1. The top 92T and the bottom 81B are constituted by the common outer surface fiber layer 2. Furthermore, the wall 3 is a common wall of the recess 81 and the recess 91.

  As shown in FIGS. 7 and 8, the wall portion 3 extends in the vertical direction with respect to the first surface side Z1 which is the one surface side or the second surface side Z2 which is the opposite surface side. More specifically, the wall portion 3 vertically connects the end portions of the outer surface fiber layers 1 and 2 at both end portions 39, 39 and surrounds the recess 81 described above from the side surface. That is, the wall 3 forms an outer wall that surrounds four sides of the recess 81 of the first surface side Z1. Thereby, the inside of the recessed part 81 forms the independent space. In the present embodiment, the four wall portions 3 form a box-shaped space. However, the number of the wall portions 3 surrounding the concave portion 81 and the shape of the concave portion formed by the wall portions 3 are not limited to this.

  The recess 81 has a depth H8 and an opening 83 having an opening diameter W8 on the first surface side Z1. The recess 91 has a depth H9 and an opening 93 having an opening diameter W9 on the second surface side Z2. The depths H8 and H9 may or may not be the same depth. It is preferable to have different depths in order to thicken the wall 3 and to improve the concealability of the whole non-woven fabric. In order to make the wall 3 thin and to improve the visibility of the colored matter from the diagonally above with respect to the wall 3, it is preferable to have the same depth.

In addition, the concealability of the colored object when viewed through the wall changes depending on the relationship between the depth H8 of the recess 81, the opening diameter W8 of the opening 83, and the opening diameter W9 of the opening 93. (See FIG. 1) is small, depending on the relationship, if the viewing angle is low, the convex apex 82 and the convex apex 92 interfere with the increase in concealment. Further, when the angle β of the oblique viewpoint is large and the viewing angle is high, the concave bottom portion 81B and the concave bottom portion 91B will be seen and the concealability will be enhanced. Therefore, depending on the relationship between the depth H8 of the recess 81, the opening diameter W8 of the opening 83, and the opening diameter W9 of the opening 93, there is a preferred angle β for viewing the wall 3.
That is, for example, when a colored object (see FIG. 1) is viewed from the opening 83 side through the opening 93 through the opening 93, the angle β and the depth H8 of the recess 81, the opening diameter W8 of the opening 83, the opening 93 It is preferable that there is a relationship between the opening diameter W9 and the following equation (R1).
(H8 / W8) ≧ tan β ≧ (H8 / (W8 + W9)) (R1)
When a colored object is viewed from the wall 3 through the next opening 93, the following equation is satisfied between the angle β and the depth H8 of the recess 81, the opening diameter W8 of the opening 83, and the opening diameter W9 of the opening 93: It is preferable that there is a relationship of (R2).
(H8 / (2 × W8 + W9)) ≧ tan β ≧ (H8 / (2 × W8 + 2 × W9)) (R2)
When a colored object is viewed from the wall 3 through N openings 93, the distance between the angle β and the depth H8 of the recess 81, the opening diameter W8 of the opening 83, and the opening diameter W9 of the opening 93 is It is preferable that there is a relationship of the following formula (R3).
(H8 / (N × (W8 + W9) −W9)) ≧ tan β ≧ (H8 / (N × (W8 + W9))) (R3)

By setting the angle β of the oblique viewpoint in the above range, it is easy to check the colored object (see FIG. 1) drawn to the back in the thickness direction of the nonwoven fabric 10 through the wall portion 3. That is, by setting the angle β viewed from the oblique viewpoint to the above range, the concealability becomes low. Further, by setting the angle β viewed from the oblique viewpoint to the above range, the difference (E _β −E _α ) of the concealment rate described above becomes large. When viewing through the wall 3 at an angle β of the oblique viewpoint, a range in which the colored material (see FIG. 1) drawn into the thickness direction of the nonwoven fabric 10 can be easily confirmed or a range in which the hiding property is low Alternatively, from the viewpoint of widening the range in which the difference in concealment rate is large, it is preferable to increase the opening diameter W9 of the opening 93, and increase the ratio of the opening diameter W9 of the opening 93 to the opening diameter W8 of the opening 83. Is preferred. When viewed through the wall portion 3 at an angle β of oblique view, it becomes easy to quickly identify colored objects (see FIG. 1) drawn into the thickness direction of the nonwoven fabric 10 or the hiding property suddenly It is preferable to increase the depth H8 from the viewpoint of realizing a high absorbability with a surprise by lowering the difference or the difference in concealment rate rapidly increasing, the depth of the opening 83 relative to the opening diameter W8 It is preferable to increase the ratio of H8.
The relationship between the angle β of the oblique view point, the depth H8 of the recess 81, the opening diameter W8 of the opening 83, and the opening diameter W9 of the opening 93 is not limited to the non-woven fabric 10D, and the irregularities such as the non-woven fabric 10B described above It can be applied to the nonwoven fabric of various aspects having a surface.

  Furthermore, the wall 3 is disposed along the width direction (X direction) of the non-woven fabric 10D and the first wall portion 31 distributed along the longitudinal direction (Y direction) of the non-woven fabric 10D as surrounding the recess 81. And a second wall portion 32. The first wall 31 vertically connects the end 11A of the first outer fiber layer 1 (11) and the end 2A of the outer fiber layer 2 as shown in FIG. The second wall 32 vertically connects the end 12A of the first outer fiber layer 1 (12) and the end 2A of the outer fiber layer 2 as shown in FIG. In FIGS. 7 and 8, the surface of the second surface Z2 when placed on a horizontal plane with the second surface Z2 down is shown as the non-woven fabric reference surface 10SS (hereinafter also referred to as a reference surface 10SS). ). Hereinafter, the vertical cross section along the width direction (X direction) of nonwoven fabric 10D shown in FIG. 7 is also called F1-F1 cross section. The longitudinal cross section along the longitudinal direction (Y direction) of nonwoven fabric 10D shown in FIG. 8 is also called F2-F2 cross section.

The wall 3 stands at an angle θ in the thickness direction with respect to the non-woven fabric reference surface 10SS. The angle θ of the wall 3 is, in the vertical cross section (F1-F1 cross section or F2-F2 cross section) at the center of the recess 81, the surface of the wall 3 (straight line corresponding to the surface of the wall 3 in cross section) and the reference surface 10SS It is an angle that The angle θ in the F1-F1 cross section is θ1, and the angle θ in the F2-F2 cross section is θ2. It is preferable that any of the angles θ1 and θ2 be within the following specified values (hereinafter, the angles θ1 and θ2 are collectively referred to as the angle θ).
The angle θ is greater than 80 °, preferably 85 ° or more, from the viewpoint of making it difficult to see colored objects in or under the non-woven fabric 10 from the wall 3 when viewed vertically from above the non-woven fabric reference surface 10SS. More preferably, it is 89 degrees or more. The angle θ is less than 100 °, preferably 95 ° or less, and more preferably 91 ° or less. That is, the vertical direction in which the wall portion 3 extends is along the direction viewed from above the vertical direction V shown in FIG.
In addition, even if the angle θ of the wall 3 with respect to the nonwoven fabric reference surface 10SS is partially out of the above range between the upper end 3A and the lower end 3B of the wall 3. For example, between the upper end portion 3A and the lower end portion 3B of the wall portion 3, the wall portion 3 viewed in the longitudinal section may have a corrugated shape.

Specifically, the angle θ of the wall 3 can be measured as follows.
First, from the first surface side Z1 surface to the second surface side Z2 surface or from the second surface side Z2 surface to the first surface side Z1 so that the nonwoven fabric 10 includes the uneven surface 8 or the uneven surface 9 It cuts to the direction and obtains a longitudinal section (F1-F1 section or F2-F2 section).
Next, the nonwoven fabric 10 is allowed to stand so that the reference surface 10SS of the nonwoven fabric 10 is horizontal, and the longitudinal cross section (F1-F1 cross section or the cross section including the recess 81, the protrusion 82, the wall 3 or the recess 91, the protrusion 92, the wall 3 The F2-F2 cross section is imaged to obtain a cross sectional image. The angle θ of the wall 3 is measured from the captured cross-sectional image.
As one of the methods of measuring the angle θ, the angle between the surface of the wall 3 to be viewed and the reference surface 10SS is measured, and this is taken as the angle θ of the wall 3. Specifically, the virtual surface J1 from the intersection 3B of the concave bottom 81B and the wall 3 toward the end 3A of the projection 82 or the intersection 3C of the concave bottom 91B and the wall 3 toward the end 3D of the projection 92 Set a virtual plane J2. The angle formed between the virtual surface J1 or J2 and the reference surface 10SS can be measured to be the angle θ of the wall 3 (see FIG. 9A).
In the case where the surface of the wall 3 to be viewed is not flat but uneven, of the uneven surface of the wall 3, the convex top located on the outer side of the wall (on the side of the recess 8 or the side of the recess 9). The virtual plane J3 or J4 is set to be in contact with The angle formed between the virtual plane J3 or J4 and the reference plane 10SS is measured, and is taken as the angle θ of the wall 3 (see FIG. 9B).
When the wall 3 is open, a virtual surface J5 extending from the intersection 3B of the concave bottom 81B and the wall 3 to the end 3A of the projection 82 or a projection 3C from the intersection 3C of the concave bottom 91B and the wall 3 A virtual plane J6 directed to the end 3D of 92 is set. The angle between the virtual surface J5 or J6 and the reference surface 10SS can be measured to obtain the angle θ of the wall 3 (see FIG. 9C).
The end 3A of the convex portion 82 is a start point or an end point of the opening diameter W8 of the opening 83 in the concave portion 81 adjacent to the convex portion 82. The end 3D of the convex portion 92 is a start point or an end point of the opening diameter W9 of the opening 93 in the concave portion 81 adjacent to the convex portion 92.

Preferably, the walls 3 surrounding the recess 81 from the side are inclined to the same degree. That is, it is preferable that the values of the angles θ of the wall portions be the same.
When the angle θ of each wall 3 with respect to the non-woven fabric reference surface 10 SS is the same, when viewed from the MD and CD directions of the non-woven fabric, the effect of decreasing the hiding property at the same angle is obtained and the non-woven fabric looks uniform It plays an effect.
Moreover, it is also preferable that the wall 3 surrounding the recessed part 81 from the side part inclines in a respectively different angle. That is, it is preferable that the values of the angles θ of the wall portions be different. When the angle θ of each wall 3 with respect to the non-woven fabric reference surface 10 SS is different, when viewing the non-woven fabric's surface 10 SA to be viewed from various angles, an effect of decreasing the concealability at different angles is obtained. Play an effect of putting a design on
Furthermore, it is also preferable that in the wall 3 surrounding the recess 81 from the side, a part is inclined to the same degree and a part is inclined at a different angle. That is, among the angles θ of the wall portions, a part of the angles θ is the same, and the other angles θ are different. For example, it is a case where the MD direction of a nonwoven fabric, CD direction, and the angle of each wall are the same. In this case, when viewed from the MD direction, the CD direction, and the like of the non-woven fabric, the effect of decreasing the hiding property at the same angle is obtained, and the effect of designing the appearance after absorption is exhibited.

  Furthermore, although not illustrated, in the non-woven fabric 10D, at least a part of the fibers of the outer surface fiber layers 1 and 2 and the wall portion 3 are fused and integrated seamlessly. Non-woven fabric 10D is bulky and thick as wall 3 connects and supports outer surface fiber layer 1 on the first surface side Z1 and outer surface fiber layer 2 on the second surface side Z2. The thickness of the nonwoven fabric 10D refers not to the local thickness of the outer surface fiber layers 1 and 2 or the wall portion 3 but to the apparent thickness of the entire nonwoven fabric in the shaped shape. In addition, in nonwoven fabric 10D, it fuse | melts in the cross point of at least one part of fibers also in each site | part except the outer surface fiber layers 1 and 2 and the wall part 3 and a connection part. Further, the non-woven fabric 10D may have intersections that are not fused. The nonwoven fabric 10D may also contain fibers other than thermoplastic fibers, including the case where the thermoplastic fibers are fused at the intersection with other fibers.

The area weight of the wall 3 is smaller than the area weight of the convex portion 82T (concave bottom portion 91B) and the concave bottom portion 81B (convex top portion 92T). Thereby, the light transmittance of the wall 3 is lower than that of the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T).
That is, the hiding power to the colored object when viewed from above obliquely with respect to the wall 3 is to the colored object when viewed from above the vertical direction to the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T). It is lower than concealment. Thereby, in the non-woven fabric 10D, the hiding property to the colored material and the visibility capable of recognizing that the colored material is drawn back are compatible. In the nonwoven fabric 10D, the wall portion 3 can be visually observed from an oblique viewpoint on the uneven surface of both surfaces, and the above-described effect is exerted on any surface side.
The vertical viewpoint and the oblique viewpoint have the same meaning as those shown in the above-mentioned nonwoven fabrics 10A to 10C. Moreover, the difference of "the hiding property" is judged as a color difference shown by (DELTA) E ^* _ab defined by the nonwoven fabric 10A.
As a method of making the basis weight of the wall 3 smaller than the basis weight of the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T), in addition to the method of partially laminating fibers and non-woven fabrics, There is a method of making the web coarse and dense beforehand. In particular, when processing is applied to the web, the web can be roughened, which is preferable. In such a case, as an example of a method of making the fabric weight of the wall 3 smaller than the fabric weight of the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T), there is a method by web stretching. This drawing process is performed when forming fibers into a web before fusion and forming the web into a concavo-convex shape. In the drawing process, constituent fibers 36 and 36 of a portion (see FIGS. 7 and 8) to be the convex top 82T (concave bottom 91B) and a portion (see FIGS. 7 and 8) to be the concave bottom 81B (convex top 92T) In the meantime, the portion of the constituent fiber 37 to be the wall portion 3 is drawn in the Z (Z1, Z2) direction (see FIG. 10). By stretching at this time, the weight of the wall 3 is reduced, and the weight is smaller than that of the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T). As a result, the degree of light scattering of the wall 3 is reduced, so the amount of light transmission is improved, and the inside of the nonwoven fabric can be easily seen through the wall 3 from an oblique direction.
In this case, since the stretching process is performed on the web before being made into a non-woven fabric, the fibers can enhance the orientation of the fibers along the vertical direction of the wall portion 3. This is more preferable in the visual observation of the oblique viewpoint, because the visibility to the colored object in the lower back is enhanced, and the difference from the visual observation of the vertical viewpoint becomes clearer.

The difference (N1-N2) between the coating weight (N1) of each of the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T) and the weight (N1) of the wall 3 is a viewpoint of securing concealment Therefore, it is 0 g / m ² or more, preferably 0.5 g / m ² or more, and more preferably 1 g / m ² or more. The difference (N1-N2) is 100 g / m ² or less, preferably 50 g / m ² or less, and more preferably 35 g / m ² or less, from the viewpoint of securing the crushing of the wall portion. is there.

The basis weight of the convex top portion 82T and the concave bottom portion 91B (outer surface fiber layer 1) is preferably 0.1 g / m ² or more, more preferably 1 g / m ² or more, from the viewpoint of securing concealability. Preferably it is 3 g / m < ² > or more. And, from the viewpoint of securing the difficulty of crushing the wall, it is preferably 1000 g / m ² or less, more preferably 100 g / m ² or less, and still more preferably 50 g / m ² or less.

The basis weight of the concave bottom portion 81B and the convex top portion 92T (the outer surface fiber layer 2) is preferably 0.1 g / m ² or more, more preferably 1 g / m ² or more, from the viewpoint of securing concealability. More preferably, it is 3 g / m ² or more. And, from the viewpoint of securing the difficulty of crushing the wall, it is preferably 1000 g / m ² or less, more preferably 100 g / m ² or less, and still more preferably 50 g / m ² or less.

The weight of the wall 3 is preferably 0.1 g / m ² or more, more preferably 0.5 g / m ² or more, and still more preferably 1 g / m ² from the viewpoint of ensuring that the wall is not easily crushed. m ² or more. And, from the viewpoint of securing the visibility, it is preferably 100 g / m ² or less, more preferably 75 g / m ² or less, and still more preferably 50 g / m ² or less.

The measuring method of the fabric weight of a nonwoven fabric cuts the nonwoven fabric of measurement object into 10 cm x 10 cm, and uses it as a sample. If a sample of 10 cm × 10 cm can not be taken, cut it into the largest possible area to use as a sample. Using a balance, measure the mass of the sample in units of g up to the second decimal place, and divide the measured value by the area of the sample to obtain the weight per unit area.
The measuring method of the fabric weight of each site | part of a nonwoven fabric cuts out each site | part from the nonwoven fabric of a measuring object. The cut width and length are precisely measured in mm to the first decimal place, and the sample is cut until the total is 50 mm ² or more. The mass of the sample, the total of which became 50 mm ² or more, was measured to the 4th decimal place in g using a precision balance, and the measured value was divided by the area of the sample to obtain the weight per unit area.
When the nonwoven fabric to be measured is incorporated into a commercially available absorbent article, the nonwoven fabric is carefully peeled off from the absorbent article using a cold spray and used as a sample. At this time, when the hot melt adhesive adheres to the sample, the hot melt adhesive is removed using an organic solvent. This approach is all the same with respect to the measurement of the other non-wovens herein.

Furthermore, as described above, the nonwoven fabric 10D has a three-dimensional structure in which the wall 3 vertically supports the outer surface fiber layers 1 and 2 which are flat surfaces. With this three-dimensional structure, when the angle β of the oblique viewpoint is changed with respect to the nonwoven fabric reference surface 10SS and viewed, it is possible to confirm excrement drawn into the lower side of the nonwoven fabric 10D at a certain angle. Thereby, the height of the absorption performance with respect to a colored thing (for example, waste fluid) can be confirmed from the nonwoven fabric 10 surface.
From such a viewpoint, it is preferable that the apparent thickness and the basis weight be in the following ranges.

  The apparent thickness of the non-woven fabric 10D is preferably 1.5 mm or more, more preferably 2 mm or more, from the viewpoint of making it easier to identify colored objects drawn deep into the thickness direction of the non-woven fabric 10 through the wall portion 3 More preferably, it is 3 mm or more. The upper limit of the apparent thickness is not particularly limited, but is preferably 100 mm or less, more preferably 50 mm or less, and still more preferably 10 mm or less, from the viewpoint of difficulty in crushing the wall. Moreover, when using as a surface material of an absorbent article, it is preferably 10 mm or less, more preferably 9 mm or less, and still more preferably 8 mm or less from the viewpoint of excellent portability and the like.

[Method of measuring apparent thickness of non-woven fabric 10D]
The measuring method of the apparent thickness of a nonwoven fabric first cuts the nonwoven fabric of measurement object into 10 cm x 10 cm, and uses it as a sample. If a sample of 10 cm × 10 cm can not be taken, cut it into the largest possible area to use as a sample. With a pressure of 50 Pa evenly applied to the entire surface of the sample, a displacement sensor is used to measure the apparent thickness of the non-woven fabric. Measure at three locations, and take the average of the three measurements as the apparent thickness of the nonwoven fabric. As a displacement sensor, OMRON Corporation high-precision displacement sensor ZS-LD80 (brand name) can be mentioned, for example.

  In the non-woven fabric 10D of the present embodiment, it is preferable to set the content as follows using the color tone changing material described above from the viewpoint of more effectively expressing the difference in “masking property”. That is, it is preferable that the content of the color tone changing material be smaller than that of the convex portion 82T (concave bottom portion 91B) and the concave bottom portion 81B (convex top portion 92T). As a result, the light transmittance of the wall 3 is lower than that of the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T), and the difference between the two in terms of concealment becomes clearer. The color tone changing material is the same as that used in the nonwoven fabric 10D described with reference to FIG. Therefore, in the non-woven fabric 10D, the contents described for the non-woven fabric 10C described above, such as the method of measuring the color tone change material, the method of containing the same, and the preferable content are applied.

Further, in the present embodiment, as a method of containing a color tone changing material, in addition to the application method described for the non-woven fabric 10C described above, there may be mentioned a method of including in advance the constituent fibers of the non-woven fabric. When the constituent fiber of the non-woven fabric comprises a plurality of resins, the plurality of resins may contain the color tone changing material evenly. Further, the color tone changing material may be unequally contained in a plurality of resins, and the color tone changing material may be contained in one resin or some of the plurality of resins. For example, in the case of a heat-fusible core-sheath fiber, if there is a color tone changing material in the sheath portion, it is likely to more effectively express the difference in "masking properties". It is hard to inhibit heat fusion and is preferable. When the non-woven fabric comprises a plurality of fibers, the plurality of fibers may contain the color tone changing material evenly, or the plurality of fibers may contain the color tone changing material unevenly, and among the plurality of fibers One or several fibers may contain the color changing material. In particular, when processing is applied to a web comprising a plurality of fibers, the content of the color tone changing material in the non-woven fabric can be changed, which is preferable. In such a case, an example of a method in which the color tone changing material contained in the wall 3 is less per unit volume than the color tone changing material contained in the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T) As a method, there is a method of drawing the web. This drawing process is performed when forming a fiber containing a color tone changing material into a web before fusion and forming the web into a concavo-convex shape. In the drawing process, constituent fibers 36 and 36 of a portion (see FIGS. 7 and 8) to be the convex top 82T (concave bottom 91B) and a portion (see FIGS. 7 and 8) to be the concave bottom 81B (convex top 92T) In the meantime, the portion of the constituent fiber 37 to be the wall portion 3 is drawn in the Z (Z1, Z2) direction (see FIG. 10). At this time, when the content of the color-tone changing material of the constituent fiber 36 and the constituent fiber 37 is different, the constituent fiber 36 having a large content becomes the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T). The component fiber 37 with a small amount of wall becomes the wall 3. In addition, by changing the content of the color tone changing material of the constituent fiber 36 and the constituent fiber 37, the content of the color tone changing material of the convex top 82T (concave bottom 91B), the concave bottom 81B (convex top 92T) and the wall 3 Can be different.
By stretching the wall 3 in the thickness direction of the nonwoven fabric 10D by the stretching process, the amount of color tone changing material per unit volume of the wall 3 can be reduced. As a result, the light transmission amount of the wall 3 is improved, and the inside of the non-woven fabric can be easily seen through the wall 3 from an oblique direction. On the other hand, the amount of color tone changing material of the top portion 82T and the bottom portion 81B is not changed by the stretching process.
In this case, since the stretching process is performed on the web before being made into a non-woven fabric, the fibers can enhance the orientation of the fibers along the vertical direction of the wall portion 3. This is more preferable in the visual observation of the oblique viewpoint, because the visibility to the colored object in the lower back is enhanced, and the difference from the visual observation of the vertical viewpoint becomes clearer.

FIG. 11 shows the results of measuring the mass change rate (DTG) / fiber input amount by taking equal amounts of fibers out of each of the convex portion, the concave bottom portion, and the wall portion in the case of performing the above-mentioned drawing processing. The specific example of the difference of content of the color tone change material of a concave bottom part and a wall part is shown. Take out 1 mg fiber from each of the convex top, concave bottom and wall, put it in a φ5 open pan (aluminum) and measure it at a temperature elevation rate of 10 ° C / min using STA7200RV (trade name) made by Hitachi High-Tech Science Co., Ltd. Did. In this example, titanium oxide was used, and the mass change rate (DTG) of the wall was about 10% lower than that of the convex top and the concave bottom. That is, the titanium oxide ratio (TiO ₂ ratio) of the wall portion is lower than the convex top portion and the concave bottom portion, and the content of the color tone changing material is reduced. Here, the TiO ₂ ratio is the content of the color tone changing material.

Furthermore, the fineness (fiber diameter) of the constituent fibers of the non-woven fabric 10D is preferably made to differ as follows from the viewpoint of more effectively expressing the difference in the "masking property".
That is, it is preferable to increase the fineness of the fibers constituting the wall 3 based on the fineness of the fibers constituting the convexity 82T (concave bottom 91B) and the fineness of the fibers constituting the concave bottom 81B (convex crest 92T). Thereby, scattering of light incident on the wall 3 is suppressed more than the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T). That is, the light transmittance in the wall 3 is higher than that of the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T). This makes the difference between the two 'masking' more clear.
As a method of changing the fineness of the fibers, in addition to a method of partially laminating fibers different in fineness newly, a method of incorporating fibers of different fineness in advance into constituent fibers of the non-woven fabric can be mentioned. In particular, when processing is applied to a web composed of a plurality of fibers, the fineness in the non-woven fabric can be changed, which is preferable. In such a case, as an example of a method of making the fineness of the fibers contained in the wall 3 larger than the fineness of the fibers contained in the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T), There is a method by stretching processing of This drawing process is performed when forming fibers into a web before fusion and forming the web into a concavo-convex shape. In the drawing process, constituent fibers 36 and 36 of a portion (see FIGS. 7 and 8) to be the convex top 82T (concave bottom 91B) and a portion (see FIGS. 7 and 8) to be the concave bottom 81B (convex top 92T) In the meantime, the portion of the constituent fiber 37 to be the wall portion 3 is drawn in the Z (Z1, Z2) direction (see FIG. 10). At this time, if the deniers of the constituent fibers 36 and the constituent fibers 37 are different, the constituent fibers 36 having relatively small deniers become the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T), and the denier is relatively large. The thick component fibers 37 become the wall 3. Further, by changing the deniers of the constituent fibers 36 and the constituent fibers 37, the deniers of the convex top 82T (concave bottom 91B), the concave bottom 81B (convex top 92T), and the wall 3 can be made different.
By stretching the wall 3 in the thickness direction of the non-woven fabric 10D by the stretching process, the fineness of the fibers of the wall 3 can be increased. As a result, the degree of light scattering of the fibers of the wall 3 is reduced, so the amount of light transmission is improved, and the inside of the non-woven fabric can be easily seen through the wall 3 from an oblique direction.
In this case, since the stretching process is performed on the web before being made into a non-woven fabric, the fibers can enhance the orientation of the fibers along the vertical direction of the wall portion 3. This is more preferable in the visual observation of the oblique viewpoint, because the visibility to the colored object in the lower back is enhanced, and the difference from the visual observation of the vertical viewpoint becomes clearer.

  The difference between the fineness of the fibers constituting the wall 3 and the fineness of the fibers constituting the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T) is as follows. From the viewpoint of making the difference in "masking property" clearer, 0.01 dtex or more is preferable, 0.05 dtex or more is more preferable, and 0.1 dtex or more is still more preferable. The difference in fineness is preferably 10 dtex or less, more preferably 5 dtex or less, and still more preferably 1 dtex or less, from the viewpoint of achieving both hiding property and visibility.

  Moreover, the fineness of the fiber which comprises convex top part 82T (concave bottom part 91B) and concave bottom part 81B (convex top part 92T) is performed as follows. From the viewpoint of obtaining the permeability of the excrement to be absorbed, it is preferably 0.1 dtex or more, more preferably 0.5 dtex or more, and still more preferably 1 dtex or more. And, in view of obtaining concealability, it is preferably 100 dtex or less, more preferably 10 dtex or less, and still more preferably 5 dtex or less.

  Moreover, the fineness of the fiber which comprises the wall part 3 is performed as follows. It is preferably 0.1 dtex or more, more preferably 0.5 dtex, from the viewpoint of obtaining visibility that is larger than the fineness of the fibers constituting the convex top 82T (concave bottom 91B) and the concave bottom 81B (convex top 92T). It is the above, More preferably, it is 1 dtex or more. And from the viewpoint of obtaining the hiding property of the whole nonwoven fabric, it is preferably 100 dtex or less, more preferably 10 dtex or less, and still more preferably 5 dtex or less.

[Method of measuring fineness]
The fineness of the fiber before non-woven fabric processing can be determined in accordance with JIS L1015.
The fineness of the non-woven fabric and the fineness of the fiber at each portion of the non-woven fabric can be determined from the fiber diameter of the cross section of the fiber. The cross-sectional shape of the fiber is measured by an electron microscope or the like, and the cross-sectional area of the fiber (the cross-sectional area of each resin component in the case of fibers formed of a plurality of resins) is measured. At the same time, the type of resin (in the case of a plurality of resins, the approximate component ratio) is specified by DSC (differential thermal analysis device), the specific gravity is determined, and the fineness is calculated. For example, in the case of a short fiber made of polyethylene terephthalate (PET), the cross section is first observed, and the cross sectional area is calculated. Then, it is comprised from resin of a single component from melting | fusing point and peak shape by measuring by DSC, and it identifies that it is a PET core. Thereafter, the density of the PET resin and the cross-sectional area are used to calculate the weight of the fiber to calculate the fineness.

Next, a more specific structure of the non-woven fabric 10 (10D) will be described.
The nonwoven fabric 10D has the 1st, 2nd outer surface fiber layers 11 and 12 as the outer surface fiber layer 1 of the 1st surface side Z1, as shown in FIG. The first and second outer surface fiber layers 11 and 12 have lengths extending along respective different directions intersecting in plan view of the nonwoven fabric 10D. The extending direction is the X direction and the Y direction orthogonal to each other along the side of the nonwoven fabric 10D. The Y direction is the longitudinal direction of the nonwoven fabric 10D, and the X direction is the width direction of the nonwoven fabric 10D.

The first outer surface fiber layer 11 extends continuously and continuously in the Y direction in plan view of the nonwoven fabric 10D. That is, the first outer surface fiber layer 11 is continuous without break throughout the length direction of the nonwoven fabric 10D. A plurality of first outer surface fiber layers 11 are spaced apart from each other in the X direction perpendicular to the Y direction.
The second outer surface fiber layer 12 extends in the X direction, and is disposed to connect the first outer surface fiber layers 11 spaced apart and parallel in the X direction. “Connecting the first outer surface fiber layers 11” means that the second outer surface fiber layers 12 adjacent to each other across the first outer surface fiber layer 11 are aligned in a straight line. Specifically, the difference between the center line of the second outer fiber layer 12 and the center line of the second outer fiber layer 12 adjacent to the first outer fiber layer 11 is the width of the second outer fiber layer 12. It means that it is a range of (longitudinal length), for example, it is within 5 mm. The second outer surface fiber layer 12 is preferably formed so that the position of the first surface side Z1 is slightly lower than that of the first outer surface fiber layer 11. Therefore, the length of the second outer surface fiber layer 12 is divided in the X direction by the interposition of the first outer surface fiber layer 11, and a plurality of the second outer surface fiber layers 12 form a line in the X direction while being separated from each other. The width (length in the Y direction) of the second outer surface fiber layer 12 is preferably smaller than the width (length in the X direction) of the first outer surface fiber layer 11. A plurality of such rows of the second outer surface fiber layer 12 in the X direction are further spaced apart from each other in the Y direction. The shape of the second outer surface fiber layer is not limited to that of the present embodiment. For example, the position and the width of the first surface side Z1 may be the same as that of the first outer surface fiber layer 11.

  As described above, in the case where the outer surface fiber layer 1 has a plurality of types in which the extension direction is different, the “different directions intersecting in plan view”, which is the extension direction, is not limited to the X direction and the Y direction. If it is the cross direction in the plane direction of nonwoven fabric 10D, various aspects can be taken.

  A plurality of outer fiber layers 2 on the second surface side Z2 are spaced apart from one another. Specifically, a plurality of the outer fiber layers 11 are separated from each other along the extending direction (Y direction) so as to cover the space between the first outer fiber layers 11 of the first surface side Z1. Have a line. Furthermore, a plurality of rows of the outer fiber layer 2 in the Y direction are spaced apart from each other in the X direction orthogonal to the Y direction. That is, the outer surface fiber layer 2 is also arranged in the X direction. Thus, the arrangement direction of the outer surface fiber layer 2 coincides with the extension direction of the outer surface fiber layer 1 at a position where the surface does not overlap the outer surface fiber layer 1. Therefore, when the extension direction of the outer surface fiber layer 1 takes a direction different from the X direction and the Y direction, the arrangement direction of the outer surface fiber layer 2 also becomes a direction different from the X direction and the Y direction accordingly.

  Further, as shown in FIGS. 6 to 8, the wall portion 3 includes a first wall portion 31 connecting the first outer surface fiber layer 11 on the first surface side Z1 and the outer surface fiber layer 2 on the second surface side Z2; It has a second wall 32 connecting the second outer surface fiber layer 12 on the first surface side Z1 and the outer surface fiber layer 2 on the second surface side Z2. A plurality of the wall portions 3 (the first wall portion 31 and the second wall portion 32) are spaced apart from each other in the planar direction of the nonwoven fabric 10D in accordance with the separation arrangement of the outer surface fiber layers 1 and 2.

  A plurality of first wall portions 31 and second wall portions 32 constituting the wall portion 3 are arranged along different directions intersecting with each other in plan view of the nonwoven fabric 10D. Specifically, the first wall portion 31 has a length corresponding to the side in the Y direction of the outer surface fiber layer 2 on the second surface side Z2, and extends the first outer surface fiber layer 11 on the first surface side Z1. It has a surface along the exit direction. That is, the surface of the first wall 31 is disposed along the Y direction. On the other hand, the second wall portion 32 has a length corresponding to the X direction side of the outer surface fiber layer 2 on the second surface side Z2, and extends in the extension direction of the second outer surface fiber layer 12 on the first surface side Z1. With a plane along. That is, the surface of the second wall 32 is disposed along the X direction. Thus, the direction along the surface of the wall 3 (the first wall 31 and the second wall 32) corresponds to the extension of the outer fiber layer 1 (the first outer fiber layer 11 and the second outer fiber layer 12). I do. Therefore, when the extension direction of the outer surface fiber layer 1 takes a direction different from the X direction and the Y direction, the direction along the surface of the wall 3 also becomes a direction different from the X direction and the Y direction accordingly.

As shown in FIG. 6, the constituent fibers 36 and 37 are oriented in the thickness direction of the non-woven fabric 10D as shown in FIG. 10 in any of the first wall portion 31 and the second wall portion 32 having different surface orientations. ing. That is, regardless of the longitudinal direction and the width direction of the nonwoven fabric 10D, the wall portion 3 is a surface facing in any direction (for example, the X direction and the Y direction) in the plane direction. The orientation in the thickness direction (Z direction) is enhanced. In the same manner as in the conventional non-woven fabric, in which the non-woven fabric in which the fibers are basically randomly oriented and fused is shaped into irregularities, the wall portions 3 oriented in such a plurality of different directions are oriented in the thickness direction It can not be. Even if there is orientation, it is one direction of machine flow at the time of non-woven fabric production. On the other hand, in the nonwoven fabric 10 of the present embodiment, the thickness of the nonwoven fabric 10 D is also in the wall 3 (in the present embodiment, the first wall 31 and the second wall 32 having surfaces orthogonal to each other) facing any direction. Longitudinal fiber orientation.
As a result, irregular reflection of light transmitted through the wall portion 3 is reduced, and it becomes easy to identify colored objects (for example, excrement) drawn to the back in the thickness direction of the nonwoven fabric, and further from the surface of the nonwoven fabric in the thickness direction Looks like it's absorbing.

The uneven surface 8 described above is disposed on the first surface side Z1 of the nonwoven fabric 10D.
The uneven surface 8 has a recess 81 surrounded by four walls 3 (two first walls 31 and two second walls 32). The recess 81 is in a region in the thickness direction from the region of the first surface side Z1 partitioned by the first outer surface fiber layer 11 and the second outer surface fiber layer 12 to the outer surface fiber layer 2 of the second surface side Z2. . The concave portion 81 has the outer surface fiber layer 2 on the second surface side Z2 as a bottom portion, and opens in the first surface side Z1. By arranging the recess 81, at least a part of light from an oblique direction in any direction with respect to the nonwoven fabric reference surface 10SS is likely to be transmitted through the wall 3. This makes it easy to see colored objects (for example, excrement) drawn to the back in the thickness direction of the non-woven fabric 10 regardless of which direction the oblique viewpoint is viewed from.

  The recessed portion 81 is surrounded by four wall portions 3 erected from the four sides of the outer surface fiber layer 2 on the second surface side Z2. Therefore, a plurality of concave portions 81 are arranged separately from each other in correspondence with the arrangement of the outer surface fiber layer 2 in the X direction and the Y direction. In this arrangement, the recesses 81 are independent without communicating with each other.

  Furthermore, the presence of the recess 81 appears to be psychologically good. Moreover, when it is used as a surface material of a diaper, an opening recalls the height of breathability and gives a feeling of comfort. Further, the space is maintained to create an air passage, which actually improves the air permeability and suppresses the stuffiness.

  In the present embodiment, the plurality of independent recesses 81 are connected in the Y direction by the first outer surface fiber layer 11 while being separated from each other. Thereby, the shape of the surface of the 1st surface side Z1 of the nonwoven fabric 10 is easy to be hold | maintained. Further, by making the first outer surface fiber layer 11 and the second outer surface fiber layer 12 have different heights on the first surface side Z1, spreading of the pressing force in the plane direction of the nonwoven fabric 10 is suppressed, which is preferable.

The uneven surface 9 of the second surface Z2 described above is disposed on the second surface Z2 of the nonwoven fabric 10D.
The uneven surface 9 has two types of concave portions 91 corresponding to two types of the outer surface fiber layer 1 (first outer surface fiber layer 11 and second outer surface fiber layer 12). Specifically, it has a recess 911 where the first outer fiber layer 11 is at the bottom and a recess 912 where the second outer fiber layer 12 is at the bottom. On the second surface side Z2, the recess 911 is continuous in the Y direction, the recess 912 is continuous in the X direction, and the recess 911 and the recess 912 are in communication.

Next, a preferred embodiment of a method of manufacturing the non-woven fabric 10D will be described below with reference to FIG.
In the method of manufacturing the nonwoven fabric 10D of the present embodiment, a male support material 120 and a female support material 130 for shaping the fiber web 110 before being made into a nonwoven fabric are used. As shown in FIG. 12A, the fiber web 110 is placed on the male support member 120, and the female female member 130 is pressed from above the fiber web 110 and sandwiched and shaped.

  The male support body 120 has a large number of protrusions 121 corresponding to the positions at which the four wall portions 3 surrounding the recess 81 of the nonwoven fabric 10D and the outer surface fiber layer 2 on the second surface Z2 are shaped. Between the protrusions 121, 121, a support concave portion 122 corresponding to a position where the outer surface fiber layer 1 on the first surface side Z1 is shaped is formed. Thus, the male support member 120 has an uneven shape, and the protrusions 121 and the support concave portions 122 are alternately arranged in directions different from each other in plan view. The support bottom portion 123 of the support concave portion 122 has a structure in which hot air blows off, and for example, a large number of holes are arranged (not shown). In addition, it is preferable that the said "different direction" is a direction which corresponds with the Y direction (longitudinal direction) and X direction (width direction) in nonwoven fabric 10D as a support body which manufactures nonwoven fabric 10D. In the manufacturing method of the present embodiment, the Y direction corresponds to the machine flow direction, and the X direction corresponds to the width direction orthogonal to the machine flow direction. However, the “different directions” differ depending on the uneven structure of the nonwoven fabric of the present invention, and are not limited to the Y direction and the X direction.

  The female support 130 has grid-like protrusions 131 corresponding to the support recesses 122 of the male support 120. Between the projections 131, 131 is a support recess 132 corresponding to the protrusion 121 of the support male member 120. Thereby, the female support member 130 has a concavo-convex shape, and the projections 131 and the support concave portions 132 are alternately arranged in directions different from each other in plan view. The support bottom portion 133 of the support recess 132 has a structure in which hot air blows off, and, for example, a large number of holes are arranged. The distance between the projections 131 is made wider than the width of the projections 121 of the male support member 120. The distance is appropriately set so that the wall portion 3 in which the fibers are oriented in the thickness direction can be suitably shaped by sandwiching the fiber web 110 by the protrusions 121 of the male support 120 and the protrusions 131 of the female support 130. .

  First, in the present embodiment, the fiber web 110 before being fused is supplied from a carding machine (not shown) to an apparatus for shaping the web so as to have a predetermined thickness.

  Next, as shown in FIG. 12A, the fiber web 110 containing thermoplastic fibers is placed on the male support 120, and the female support 130 is pushed onto the male support 120 from the fiber web 110. At this time, the projections 121 of the male support member 120 are inserted into the support concave portions 132 of the female support member 130. Further, the protrusion 131 of the female support member 130 is inserted into the support concave portion 122 of the male support member 120. This creates a shape in which the fibers are oriented in the thickness and planar directions.

In this state, as shown in FIG. 12 (B), the first hot air W1 is blown to the fiber web 110 from the side of the female support 130. That is, the first hot air W1 is blown from the side to be the second surface of the nonwoven fabric 10. Thus, the fiber web 110 is fused to an extent that the uneven shape of the nonwoven fabric 10 can be maintained. In the fiber web 110, the fibers are very loosely fused.
Furthermore, between the top of the protrusion 121 and the bottom of the support recess 132, the blowout of the first hot air W1 is suppressed, and the fibers are fused in the planar direction. Thereby, the fiber layer corresponding to the outer surface fiber layer 2 on the second surface side Z2 is shaped. In addition, the fibers are oriented in the planar direction between the bottom of the support recess 122 and the top of the protrusion 131. Since the projections 131 inhibit the hot air, the fiber layer to be formed is less fused and a smooth fiber layer can be obtained. Thereby, the fiber layer corresponding to the outer surface fiber layer 1 on the first surface side Z1 is shaped. At this time, the shape of the wall portion oriented in the thickness direction is also maintained.
The arrows in the drawing schematically show the flow of the first hot air W1.

The temperature of the first hot air W1 is set to a temperature at which the thermoplastic fiber can maintain its shape in the thickness direction and in the planar direction. Considering a general fiber material used for this type of product, it is preferable that the melting point of the thermoplastic fiber constituting the fiber web 110 be higher by 0 ° C. to 70 ° C., higher by 5 ° C. to 50 ° C. More preferable.
The speed of the first hot air W1 is preferably 2 m / s or more, and more preferably 3 m / s or more, from the viewpoint of effective fusion. In addition, the speed of the first hot air W1 is preferably 100 m / s or less, and more preferably 80 m / s or less, from the viewpoint of reducing the size of the device.
In this manner, the fiber web 110 is temporarily fused and held in an uneven shape.
The height of the protrusions 121 of the male support member 120 and the height of the protrusions 131 of the male support member 130 are appropriately determined depending on the apparent thickness of the non-woven fabric 10 to be manufactured. For example, 2 mm or more is preferable, 3 mm or more is more preferable, 5 mm or more is more preferable, 15 mm or less is preferable, 10 mm or less is more preferable, and 9 or less is more preferable.

Next, the support female member 130 is removed, and as shown in FIG. 12C, the second hot air W2 is blown at a temperature at which each fiber of the fiber web 110 shaped into the concavo-convex shape can be appropriately fused. The fibers are further fused together. Also in this case, similar to the first hot air W1, the second hot air W2 is blown to the fiber web 110 from the side to be the second surface of the nonwoven fabric 10. The temperature of the second hot air W2 at this time should be higher than the melting point of the thermoplastic fiber constituting the fiber web 110 by 0 ° C. or more and 70 ° C. or less in consideration of a general fiber material used for this type of product C. is preferable, and it is more preferable that the temperature is higher than 5.degree. C. and lower than 50.degree.
The wind speed of the second hot air W2 is preferably 2 m / s or more, and more preferably 3 m / s or more, although it depends on the height of the protrusions 121 of the male support member 120. As a result, the heat transfer to the fibers can be made sufficient to fuse the fibers together, and the fixing of the uneven shape can be made sufficient. Moreover, 100 m / s or less is preferable and, as for the wind speed of 2nd hot air W2, 80 m / s or less is more preferable. Thereby, excessive heat transfer to a fiber can be suppressed and the feel of the nonwoven fabric 10 can be made favorable.
The process of spraying the first hot air W1 can be omitted by reducing the surface roughness of the female support member. Further, by reducing the surface roughness, it is possible to remove the female support member 130 in the process of spraying the second hot air W2 without sticking unfused fibers. That is, after producing the web, it is possible to fit the support male member 120 and the support female member 130, remove the support female member 130 as it is, and treat with the second hot air W2. This makes processing simpler.

As a thermoplastic fiber, what is normally used as a raw material of a nonwoven fabric can be employ | adopted without a restriction | limiting in particular. For example, fibers made of a single resin component or composite fibers made of a plurality of resin components may be used. Examples of the composite fiber include a core-sheath type, a side-by-side type, and the like.
When a composite fiber containing a low melting point component and a high melting point component (for example, a core-sheath composite fiber having a low melting point component and a core having a high melting point component) is used as the thermoplastic fiber, the temperature of the hot air blown to the fiber web 110 is low It is preferable that it is not less than the melting point of the melting point component and less than the melting point of the high melting point component. More preferably, the temperature is 10 ° C. lower than the melting point of the low melting point component or higher than the melting point of the high melting point component, and still more preferably 20 ° C. or more higher than the melting point of the low melting point component by 5 ° C. or higher .

  The nonwoven fabric 10D is produced as described above. Between the protrusions 121 of the male support 120 and the protrusions 131 of the female support 130, the fibers of the fiber web 110 are aligned and oriented in the thickness direction, and the wall 3 is formed. At this time, the wall 3 in which the fibers are oriented in the thickness direction (longitudinal direction) is formed on the surface directed in any direction around the protrusion 121. Thereby, the recessed part 81 by which the side was enclosed by four wall parts 3 which nonwoven fabric 10D has is formed. In addition, between the top of the protrusion 121 and the bottom of the support recess 132, the outer surface fiber layer 2 of the second surface Z2 in which the fibers are oriented in the planar direction is formed. In addition, the outer surface fiber layer 1 on the first surface side Z1 in which the fibers are oriented in the planar direction is formed between the bottom of the support recess 122 and the top of the protrusion 131.

  The lower surface of the non-woven fabric 10D obtained is the first surface side Z1 in FIG. 12C, and the opposite surface is the second surface side Z2. That is, the first surface side Z1 in the nonwoven fabric 10D is the side on which the male support member 120 is disposed, and the second surface side Z2 is the side on which the first hot air W1 and the second hot air W2 are blown. Therefore, the fusion points of the fibers of the outer surface fiber layer 2 on the second surface side Z2 become larger than the outer surface fiber layer 1 on the first surface side Z1 due to the difference in the blowing amount of the first hot air W1. Further, due to the difference in heat quantity, the surface of the outer surface fiber layer 1 on the first surface side Z1 has less feeling of roughness and a better touch than the surface of the outer surface fiber layer 2 on the second surface side Z2. Even if the step of blowing the first hot air W1 is omitted, the same effect can be obtained by the distance from the second hot air W2. Further, by inserting the male support member 120 into the female support member 130 while holding the fiber web 110, the fibers of the outer fiber layer 2 on the second surface Z2 are pulled, and the male support member 120 is further inserted. And head. Therefore, the second surface side Z2 formed on the top of the protrusion 121 of the male support member 120 rather than the outer fiber layer 1 of the first surface side Z1 formed on the bottom of the support concave portion 122 of the male support member 120 The amount of fibers in the outer fiber layer 2 is reduced.

  In the manufacturing method of the present embodiment, in consideration of continuous production, it is preferable to use a conveyor type or a drum type capable of transporting an apparatus incorporating the support male member 120 and the support female member 130. Moreover, after removing the female support 130, it is preferable to peel off the shaped nonwoven fabric 10 from the male support 120 and to roll it up in a roll (not shown).

  In this manufacturing method, the thickness of the non-woven fabric 10D is appropriately determined by the heights of the protrusions 121 of the male support 120 and the protrusions 131 of the female support 130. For example, increasing the height of the protrusions increases the apparent thickness of the sheet, and decreasing the height reduces the apparent thickness of the sheet. In addition, when the height of the protrusions is increased, the fiber density of the non-woven fabric 10D is decreased, and when it is decreased, the fiber density of the non-woven fabric 10D of the sheet is increased.

  The nonwoven fabric 10 (10A-10D) demonstrated by each embodiment is applicable to the surface sheet etc. of absorbent articles, such as a sanitary napkin and a disposable diaper, for example. When using as a surface sheet, you may use either side toward a wearer's skin surface. However, when viewed at a different angle with respect to the nonwoven fabric reference surface, it is easy to check the excrement drawn into the thickness direction of the nonwoven fabric at a certain angle, and the impression of absorbing the thickness direction from the nonwoven fabric surface In order to easily recall, it is preferable to use the first surface side Z1 toward the skin surface side of the wearer. In addition, from the viewpoint of excellent cushioning properties and soft touch, it is possible to use the first surface side Z1 opposite to the surface to which hot air hits at the time of manufacture toward the skin surface side of the wearer. It is preferable because there are relatively few points and the texture is smooth.

  Next, the basic configuration of a thin sanitary napkin 100 using the non-woven fabric 10 as a surface sheet will be described below with reference to FIG. In FIG. 13, the width direction of the sanitary napkin 100 is indicated by X, and the longitudinal direction is indicated by Y.

  As shown in FIG. 13, the sanitary napkin 100 includes a vertically elongated main body 104. The main body 104 includes a liquid-permeable top sheet 101 disposed on the skin contact surface side, a liquid-impervious back sheet 102 disposed on the non-skin contact surface side, and the top sheet 101 and the back sheet 102. And an absorber 103 having liquid retention. Both sides of the main body 104 are provided with wings 105 (105a, 105b) extending outward. In the drawing, the wing 105 is shown in a folded state.

  The shape of the main body 104 is longitudinally long having a longitudinal direction (Y direction) disposed from the lower abdomen side to the buttock side through the crotch portion of the wearer at the time of wearing and a width direction (X direction) orthogonal thereto. It is a shape. In the present invention, unless otherwise specified, the side in contact with the human body is referred to as the skin contact surface side or the surface side, and the side in contact with the undergarment is referred to as the non-skin contact surface side or the back surface side. Furthermore, a direction having a relative length in plan view of the sanitary napkin 100 is referred to as a longitudinal direction, and a direction orthogonal to the longitudinal direction is referred to as a width direction. The longitudinal direction typically coincides with the longitudinal direction of the human body in the worn state.

  The nonwoven fabric 10 is used for the top sheet 101. At this time, the concave portion 81 is disposed on the skin contact surface side.

The back sheet 102 is not particularly limited as long as it is waterproof and has moisture permeability. For example, a film as described in JP 2013-128628 A is used.
As the absorbent body 103, for example, a fiber assembly or a combination of this and an absorbent polymer can be used. For example, the fiber assembly as described in Unexamined-Japanese-Patent No. 2013-128628 is used. Further, a covering sheet (not shown) for covering the absorber 103 may be used.
The wing 105 is made of a soft non-woven fabric having water repellency, bulkiness, and a low fiber density, and the base thereof is sandwiched and fixed between the top sheet 101 and the back sheet 102. For the wing 105, for example, a non-woven fabric as described in JP 2013-128628 A is used.

  Since the sanitary napkin 100 uses the non-woven fabric 10 for the surface sheet 101, the thickness direction back of the non-woven fabric 10 at a certain angle when viewed from a different angle with respect to the non-woven fabric reference surface 10SS (see FIG. 1). It is easy to confirm excrement that has been drawn up. Moreover, it becomes easy to recall the impression currently absorbed from the surface of a nonwoven fabric to the thickness direction back, and it seems to be absorbed from the surface to the thickness direction back. That is, the user can check the excrement drawn to the back by twisting the hand against the impression when holding the sanitary napkin 100 in hand and looking at the reference surface 10 SS, and recall the impression absorbed in the back Can. The "hand" referred to here means from the shoulder to the fingertip and includes the arm. In addition, twisting the hand mainly refers to twisting the wrist or forearm. Here, by the action of twisting the hand, it is felt that the hand is felt more than 10 °, that of the hand felt like it was twisted to the limit 80 °, that of the hand felt like it was twisted to the limit Is 80 °. In addition, it is 90 ° or more to feel that the hand is twisted to the inner limit, and 80 ° to feel the hand to the outer limit. For this reason, by using the non-woven fabric 10 whose concealability is low in the diagonal direction S for the sanitary napkin 100, it is possible to impart a function of changing the impression when the hand is twisted. The same effect can be obtained as the nonwoven fabric 10 not only as a top sheet but also as a back sheet, an intermediate sheet between the top sheet and the back sheet, and an absorber sheet.

  The nonwoven fabric of the present invention can be used in various applications. For example, it can be used suitably as a surface sheet of absorbent articles, such as a disposable diaper for adults and infants, a sanitary napkin, a panty liner, and a urine absorption pad. Furthermore, it can also be used as a sublayer to be interposed between a surface sheet such as a catamenial product or a diaper and an absorber, a covering sheet (core wrap sheet) of an absorber, or the like.

  EXAMPLES Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not construed as being limited thereby. In the examples, “%” is based on mass unless otherwise specified.

Example 1
The nonwoven fabric shown in FIG. 6 is made of a thermoplastic fiber having a fineness of 1.5 to 1.6 dtex containing 2.7 to 3% by mass of titanium oxide (TiO ₂ ) as a color tone changing material, and includes the manufacturing process shown in FIG. It manufactured by the air through manufacturing method. This was used as the non-woven fabric sample of Example 1. The spraying process with the first hot air W1 was performed under the conditions of a temperature of 160 ° C., a wind speed of 55 m / s, and a spraying time of 3 s. The second hot air spraying process was performed under the conditions of a temperature of 160 ° C., an air velocity of 55 m / s, and a spraying time of 3 s.
The nonwoven fabric sample of Example 1 had an apparent thickness of 7.2 mm. The depth H8 of the recess 81 was 6 mm, and the opening diameter W8 was 2 mm in the CD direction and 3 mm in the MD direction. The depth H9 of the recess 91 was 6 mm, and the open hole diameter W9 was 2 mm in the CD direction and 1.5 mm in the MD direction. The convex portion 82T had a mass change rate (hereinafter also referred to as DTG) / fiber input amount of 30% / min. The concave bottom portion 81B had a DTG / fiber input amount of 30% / min. The wall 3 had a DTG / fiber input of 27% / min. The wall angle θ, the basis weight, the TiO ₂ ratio, the hiding ratio, and the fineness were as shown in Table 1.

(Example 2)
The non-woven fabric sample of Example 2 was obtained by reversing the non-woven fabric sample produced in the same manner as in Example 1.
The nonwoven fabric sample of Example 2 had an apparent thickness of 7.2 mm. The depth H8 of the recess 81 was 6 mm, and the open hole diameter W8 was 2 mm in the CD direction and 1.5 mm in the MD direction. The depth H9 of the recess 91 was 6 mm, and the open hole diameter W9 was 2 mm in the CD direction and 3 mm in the MD direction. Moreover, as for convex part 82T, DTG / fiber input was 30% / min. The concave bottom portion 81B had a DTG / fiber input amount of 30% / min. The wall 3 had a DTG / fiber input of 27% / min. The wall angle θ, the basis weight, the TiO ₂ ratio, the hiding ratio, and the fineness were as shown in Table 1.
(Example 3)
The non-woven fabric sample of Example 3 is the non-woven fabric 10A shown in FIG. 3, and using thermoplastic fibers with a fineness of 2.5 dtex containing 0.15% by mass of TiO ₂ as a color tone change material Another semi-dal nonwoven fabric was made. Further, using a thermoplastic fiber having a fineness of 2.5 dtex and containing 3% by mass of TiO ₂ as a color tone changing material, a full-modal non-woven fabric was produced by an air through manufacturing method. A semi-dual non-woven fabric, a full-dual non-woven fabric is slit, and each of the other semi-dual non-woven fabrics is alternately laminated by slitting on both sides and bonded by air through to obtain a non-woven fabric having the basis weight, TiO ₂ ratio, hiding ratio and denier shown in Table 1 10A was made. At that time, the semi-dal nonwoven fabric and the full-dal nonwoven fabric were disposed to face each other with another semi-dal nonwoven fabric interposed therebetween.
(Example 4)
The non-woven fabric sample of Example 4 is the non-woven fabric 10B shown in FIG. 4, and using a thermoplastic fiber having a fineness of 2.5 dtex containing 0.15% by mass of TiO ₂ as a color tone change material Made. Further, using a thermoplastic fiber having a fineness of 2.5 dtex and containing 3% by mass of TiO ₂ as a color tone changing material, a full-modal non-woven fabric was produced by an air through manufacturing method. The fludal nonwoven fabric was slit, and the fludal nonwoven fabric was spaced apart on both sides of the semi-dal nonwoven fabric. At that time, at the opposite position of the fludal nonwoven fabric disposed on one side of the semi-dal nonwoven fabric, the recesses between the fludal nonwoven fabrics disposed on the other side of the semi-dal nonwoven fabric are disposed to face each other. That is, a full dal nonwoven fabric was made into a convex part, this convex part and a crevice were arranged alternately, and a full dal nonwoven fabric and a crevice were arranged oppositely on both sides of a semi dal nonwoven fabric. After arranging in this way, bonding was carried out by air through to prepare a non-woven fabric 10B having the wall angle θ, the basis weight, the TiO ₂ ratio, the hiding ratio and the fineness shown in Table 1.
In the nonwoven fabric sample of Example 4, the depth of the concave portion 26 of the first surface layer 24 corresponding to the concave portion 81 of Example 1 was 6 mm, and the opening diameter was 3 mm in the CD direction. In addition, the depth of the recess 26 of the second surface layer 25 corresponding to the recess 91 of Example 1 was 6 mm, and the opening diameter was 3 mm in the CD direction.
(Example 5)
The non-woven fabric sample of Example 5 is the non-woven fabric 10C shown in FIG. 5 and is different from the non-woven fabric according to the air-through manufacturing method using a thermoplastic fiber having a fineness of 2.5 dtex containing 0.15% by mass of TiO ₂ as a color tone change material. The non-woven fabric of Then, the non-woven fabric was slitted, laminated on one side of another non-woven fabric at intervals, and bonded by air through to prepare non-woven fabric 10C. Thereafter, a spray paste is used to apply 3 mass% of titanium oxide (TiO ₂ ) of the color tone changing material 6 to the prepared non-woven fabric sample, and the angle θ of the wall shown in Table 1 and the coating weight, TiO _{It was set as} the nonwoven fabric sample of Example 5 which has ₂ ratio, concealment rate, and fineness.
In the nonwoven fabric sample of Example 5, the depth of the recess 29 on one surface 10SA side corresponding to the recess 81 of Example 1 was 6 mm, and the opening diameter was 3 mm in the CD direction.

(Comparative example 1)
A flat non-woven fabric which is not unevenly shaped by air-through manufacturing method is produced by using a thermoplastic fiber having a fineness of 2.5 dtex containing 3 wt% of titanium oxide (TiO ₂ ) as the color tone changing material 6. . The non-woven fabric sample had a total thickness of 2.0 mm, a basis weight, a TiO ₂ ratio, a hiding ratio, and a fineness as shown in Table 1.
(Comparative example 2)
The surface sheet was peeled off from Laurier F, a combination bare skin (trade name, manufactured by Kao Corporation 2016), and the peeled surface sheet was used as the nonwoven fabric sample of Comparative Example 2. The non-woven fabric sample of Comparative Example 2 had a total thickness of 2.2 mm, and the angle θ of the wall, the weight per area, the ratio of TiO ₂ , the hiding ratio, and the fineness were as shown in Table 1. In the non-woven fabric sample of Comparative Example 2, the depth of the recess corresponding to the recess 81 of Example 1 was 1.5 mm, and the opening diameter was 3 mm in the CD direction and 3 mm in the MD direction.
(Comparative example 3)
A circle having a radius of 3 mm was cut at intervals of 6 mm in the MD direction and at intervals of 6 mm in the CD direction in the flat nonwoven fabric having the apertures prepared by the manufacturing method of Comparative Example 1 to obtain a nonwoven fabric sample of Comparative Example 3. The non-woven fabric sample of Comparative Example 3 had a total thickness of 2.0 mm, and was a flat non-woven fabric having openings as shown in Table 1 in the basis weight, TiO ₂ ratio, hiding ratio and fineness. In the nonwoven fabric sample of Comparative Example 3, the depth of the opening is measured as the depth of the recess corresponding to the recess 81 of Example 1, and the value is 2 mm, and the opening diameter is 6 mm in the CD direction, MD direction To 6 mm.
(Comparative example 4)
The surface sheet was peeled off from Mooney Airfit S size (trade name, Uni Charm Co., Ltd. 2016), and the peeled surface sheet was used as the nonwoven fabric sample of Comparative Example 4. The total thickness of the non-woven fabric sample of Comparative Example 4 was 1.1 mm, and the angle θ of the wall portion, the basis weight, the ratio of TiO ₂ , the hiding ratio, and the fineness were as shown in Table 1. In the nonwoven fabric sample of Comparative Example 4, the depth of the recess corresponding to the recess 81 of Example 1 was 0.5 mm, and the opening diameter was 2 mm in the CD direction.
(Comparative example 5)
Pampers The first S-size to the first skin of Pampers (trade name, manufactured by The Procter End Gamble Company 2016) was peeled away, and the peeled surface sheet was used as the nonwoven fabric sample of Comparative Example 5. The non-woven fabric sample of Comparative Example 5 had a total thickness of 0.5 mm, and was a flat non-woven fabric having openings as shown in Table 1 in the basis weight, TiO ₂ ratio, hiding ratio and fineness. In the nonwoven fabric sample of Comparative Example 5, the depth of the opening is measured as the depth of the recess corresponding to the recess 81 of Example 1, the value is 0.5 mm, and the opening diameter is 2 mm in the CD direction, It was 3 mm in the MD direction.

The concealment rate (ΔE ^* _ab ) and the difference between the concealment rates (E _β -E _α ) were determined for the examples and comparative examples described above.
Based on the above-mentioned (opacity measurement methods), imaged in the optical axis L1 (see FIG. 2) were inclined by 10 ° from 30 ° to 90 ° position of the imaging device, L at each angle ^* a ^* b ^* Three-dimensional orthogonal coordinates (L ^* , a ^* , b ^* ) of color space were measured. The color difference between the measured value and the color coordinate of the white reference value was calculated as the hiding ratio (ΔE ^* _ab ). Among contrast ratio (ΔE ^* _ab), and concealing property E _alpha results when viewed from the vertical direction (90 °), was hiding E _beta when viewed from an oblique direction (80 ° ~30 °). The difference between the two was determined as the difference in hiding rate (E _β -E _α ). The results were as shown in Tables 1 and 2. Further, the relationship between the depth of the recess and the opening diameter and the angle β was as shown in Table 3.

As shown in Table 2, Examples 1 to 5 are viewed in a near white state with a concealing rate ΔE ^* _ab lower than Comparative Examples 1 and 3 when viewed from the vertical direction (90 °). Therefore, the concealment was high. Furthermore, in Examples 1 to 5, there is an angle in the visual direction at which the difference in concealment rate E _β -E _α is 0.5 or more at least in the CD direction than in Comparative Examples 1 to 5, and the visibility in that angle Was excellent. In particular, Examples 1 and 2 had a viewing angle with excellent visibility from oblique directions in the MD direction as well as in the CD direction. On the other hand, in Comparative Examples 1 to 5, the hiding rate in the oblique direction was lower than the hiding rate in the vertical direction, and no contrast of visibility was observed. In particular, Comparative Example 2 having an uneven surface shows a low hiding ratio at any angle of view, and does not have a high visibility angle. As described above, it is understood that Examples 1 to 5 have contradictory properties of the hiding property to the colored object when viewed from above in the vertical direction and the visibility to the colored object when viewed from above in the oblique direction. The
In Examples 1, 2, 4 and 5, as shown in Table 3, with respect to the concavo-convex surface, β satisfying the relationship of the above-mentioned expressions (R1), (R2) and (R3) is within 80 ° -30 °. Comparative Examples 2 to 5 did not have β satisfying 80 ° to 30 ° satisfying the above relationship. In Examples 1, 2, 4 and 5, as shown in Tables 2 and 3, it was found that the combination of the depth of the recess, the opening diameter, and the viewing angle satisfying the above-mentioned relational expressions produces higher contrast of visibility . Specifically, as shown in Table 2, MD 60 ° · CD 60 ° in Example 1, MD 60 ° · MD 30 ° · CD 60 ° in Example 2, CD 60 ° · CD 30 ° in Example 4, CD 60 ° in Example 5. The difference between the hiding rate of the CD 30 ° oblique view and the hiding rate of the vertical view was large.

3 wall 10, 10A to 10D non-woven fabric 10SA one side (first side)
10SB other side (second side)
26, 29 Recess 28 Convex part 28A Convex top part 29A Concave bottom part 300 Colored material S Diagonal direction V Vertical direction

Claims (7)

  A non-woven fabric comprising a region having a lower hiding property to a colored object when viewed from obliquely above than the hiding property to a colored object when viewed from above the vertical direction on one side of the non-woven fabric.   The nonwoven fabric according to claim 1, further comprising: a convex-concave portion, a concave bottom, and an uneven surface having a wall portion connecting the convex crest and the concave bottom.   The concealing property to a colored object when viewed from above the oblique direction with respect to the wall portion is lower than the concealing property to a colored object when viewed from above the vertical direction to the convex top portion and the concave bottom portion. Non-woven fabric. The non-woven fabric has a convex-concave portion, a concave bottom portion, and an uneven surface having a wall portion connecting the convex peak portion and the concave bottom portion on one surface side of the non-woven fabric, and the wall portion corresponds to the one surface or the opposite surface Extending vertically with respect to the
Non-woven fabric wherein the amount of coating of the wall portion is smaller than the amount of coating of the convex top portion and the concave bottom portion. The non-woven fabric contains a color tone changing material,
The non-woven fabric according to any one of claims 2 to 4, wherein the wall portion has a content of the color tone changing material smaller than that of the convex top portion and the concave bottom portion.   The non-woven fabric according to any one of claims 2 to 5, wherein the wall portion has a denier of constituent fibers larger than that of the convex top portion and the concave bottom portion.   The absorbent article using the nonwoven fabric of any one of Claims 1-6.