Individually packaged absorbent articles

Abstract

To provide an individual package of an absorbent article capable of simultaneously achieving easiness of opening and a sense of security for tamper-proof.SOLUTION: An individual package 30 comprises: a most laminated area 36, the area including opening ends 35 of both side edges 34 and 34, in which the number of packaging sheets 20 laminated without interposing the absorbent article 10 is greater than that of a minimum laminated area 37 having the least number thereof; and a colored band area 5 on a first surface side located within a length range along a longitudinal direction Y of the absorbent article in the most laminated area and having a color that distinguishes the same from a surrounding area thereof. Each of fusion parts 4 located in the colored band areas, of both side edges includes a first fusion part formed by continuously and integrally bonding a plurality of laminated packaging sheets, and a second fusion part enclosing the first fusion part. When viewed planarly from the first surface side, the first fusion part is darker in a color than the second fused part, the second fusion part includes a recessed part recessed in a thickness direction at a part exposed to the first surface side, and an area of the first fusion part when viewed planarly from the first surface side is larger than an area when viewed planarly from the second surface side.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an individual package for an absorbent article. [Background technology]

[0002] It is known that absorbent articles such as sanitary napkins are sold individually packaged. For example, pad-type absorbent articles such as sanitary napkins are usually wrapped in a packaging sheet, folded lengthwise, and stacked in the thickness direction to form an individually packaged package. A plurality of such individually packaged articles are then placed in an inner bag and delivered to consumers. Various ideas have been proposed for the individually packaged articles in terms of the stability of the packaged state and the ease of opening (ease of opening) (e.g., Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-521117 [Patent Document 2] Patent Publication No. 2021-186401 [Patent Document 3] Japanese Patent Application Publication No. 2019-84142 Summary of the Invention [Problem to be solved by the invention]

[0004] In the packaging form of the individual package, it is common to provide multiple fused portions on both side edges to seal the package and prevent the inclusion of foreign matter while taking into consideration ease of opening. However, both side edges of the individual package include a top-layered region, which includes the opening edge of the individual package and where the number of individual packaging film layers is greater than in the surrounding area. In general, in this region, the fusion is stronger than in the minimum-layered region due to the increased thickness caused by the lamination. In particular, if the degree of strong fusion is too high in the top-layered region where the fused portions are formed at or near the opening edge of the individual package, the seal peeling operation starting from the opening edge may not proceed smoothly. In recent years, there has been an increasing demand from users who want to use absorbent articles quickly for a package that has the fusion strength necessary to prevent the inclusion of foreign matter while also allowing for a smooth opening operation. In addition, packaging sheets are generally printed with various colors to enhance the appearance design and thereby appeal to consumers. In the colored regions, the fused portions are formed by pressing between heated rolls, so the fused portions retain the same color as the surrounding colored regions and are inconspicuous, reducing the visibility of the fused portions. The visibility of the fused portions can impress upon users the sealing performance of the absorbent article inside the individual package, i.e., the high level of hygienic integrity that prevents the intrusion of foreign matter. However, if the visibility of the fused portions is low, even if sufficient fusion is provided, the user's visual sense of security regarding the hygienic integrity of the absorbent article may be impaired, and there is room for improvement in this regard.

[0005] The present invention relates to an individual package for absorbent articles that can simultaneously realize ease of opening near the opening end of the individual package and a sense of security that foreign matter has not been mixed in due to improved visibility of the fused portion. [Means for solving the problem]

[0006] The present invention provides an individual package for an absorbent article, the individual package comprising an absorbent article and a packaging sheet that wraps the absorbent article in a state where the absorbent article is folded in the longitudinal direction, the individual package comprising a plurality of fused portions that join the packaging sheets together, on each of a pair of side edge portions that are outward in the width direction of the absorbent article and along the longitudinal direction of the absorbent article, the individual package comprising a first surface on which an open end of the packaging sheet located at one end side of the longitudinal direction of the absorbent article is exposed, and a second surface that is exposed on the opposite side to the first surface, the open end extending along the width direction and including the both side edge portions, the individual package comprising a minimum stacking area in which the number of packaging sheets stacked without the absorbent article in between is the smallest, as the area including the open end of the both side edge portions. and a colored band region on the first surface side which is located within the colored band regions of both side edges and has a color that is distinct from its surroundings, wherein the fused portions located within the colored band regions of both side edges have a first fused portion where the stacked packaging sheets are continuously and integrally joined, and a second fused portion surrounding the first fused portion, wherein the first fused portion has a darker color than the second fused portion in a planar view from the first surface side, and the second fused portion has a recess that is recessed in the thickness direction in a part exposed to the first surface side, and the area of ​​the first fused portion when viewed in a planar view from the first surface side is larger than the area when viewed in a planar view from the second surface side. [Effects of the Invention]

[0007] The individual package of the absorbent article according to the present invention can simultaneously realize ease of opening near the opening end of the individual package and a sense of security that foreign matter is not mixed in due to the improved visibility of the fused portion. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a plan view schematically showing a preferred embodiment of an individual package of an absorbent article according to the present invention, viewed from the first surface side where the opening end is exposed. [Figure 2] FIG. 2 is an enlarged cross-sectional view schematically showing a cross section of the individual package shown in FIG. 1 taken along line II-II. [Figure 3]2A is an enlarged cross-sectional view schematically showing the cross section of the side edge portion of the individual package shown in FIG. 1 taken along line II-II, and FIG. 2B is an enlarged cross-sectional view schematically showing another embodiment of the side edge portion. [Figure 4] (A) is a photographic drawing showing an enlarged portion of an example of the uppermost layer region including the colored band region on the first surface side of the side edge portion, and (B) is a photographic drawing showing an enlarged portion of the fused portion in (A). [Figure 5] (A) is a photograph in place of a drawing showing the planar areas of the first fusion portion and the second fusion portion in a plan view from the first surface side of the fusion portion shown in Figure 4(B) divided by dashed lines, and (B) is a photograph in place of a drawing showing the planar area of ​​the first fusion portion in a plan view from the second surface side of the fusion portion divided by dashed lines. [Figure 6] 5(A) to 5(C) are photographs in place of drawings showing an example of a method for defining the boundary of the first surface side region of the fused portion shown in FIG. 5(A). [Figure 7] (A) is a photograph in lieu of a drawing showing the cross-sectional state of the fused portion with the cross section exposed, taken at an inclination angle of 90° relative to the first surface side, and (B) is a photograph in lieu of a drawing showing the cross-sectional state taken at an inclination angle of 60°. [Figure 8] 10 is an explanatory diagram schematically illustrating the difference in external force applied to the first surface side and the second surface side of a fused portion including a first fused portion and a second fused portion. FIG. [Figure 9] 10 is a photograph in place of a drawing showing a preferred embodiment of a region in the second fused portion where recesses are arranged. [Figure 10] 1(A) and 1(B) are plan views schematically showing a preferred embodiment of the planar shape of the second surface side of the first fused part. [Figure 11] 10 is a photograph, shown as a substitute for a drawing, illustrating a preferred embodiment of a cross section in the thickness direction of the second fused portion. [Figure 12] 10 is a photograph in place of a drawing showing a preferred embodiment of the connection portion between the bonded portion of the second fused portion and the first fused portion. [Figure 13] 10 is a photograph as a substitute for a drawing showing an example of a combination of the average thickness of the first fused portion and the average thickness of the packaging sheet 20 at the second fused portion in a cross section in the thickness direction of the fused portion. DETAILED DESCRIPTION OF THE INVENTION

[0009] The individual packaging of the absorbent article of the present invention includes an absorbent article and a packaging sheet that wraps the absorbent article in a folded state in the longitudinal direction. Regarding this wrapping, the absorbent article and the packaging sheet may be folded together with the packaging sheet on the outside, or the folded absorbent article may be wrapped with the packaging sheet. The number of folds can be appropriately determined depending on the length of the absorbent article, the size of the individual packaging, etc. The packaging sheet may consist of a single sheet or multiple sheets.

[0010] The absorbent article refers to an article that can be attached to clothing such as underwear and worn on the wearer's body to absorb and retain excrement, etc. Examples include sanitary napkins and panty liners (discharge sheets). The absorbent article has a longitudinal shape when unwrapped and unfolded, and has a front portion, a middle portion, and a rear portion corresponding to the wearer's abdominal portion, crotch portion, and back portion. In this shape, it has a longitudinal direction corresponding to the direction connecting the wearer's abdominal portion, crotch portion, and back portion, and a width direction perpendicular to the longitudinal direction. Similarly, the packaging sheet has a longitudinal direction and a width direction when unwrapped and unfolded. In the individual package, the absorbent article is folded along the longitudinal direction as described above. The packaging sheet is also folded along the longitudinal direction of the absorbent article. Therefore, in the individual package, the direction along the longitudinal direction of the absorbent article is the folding direction of the absorbent article and the packaging sheet, and is also the opening direction of the individual package, which is opposite to the folding direction. Hereinafter, the longitudinal direction and width direction of the absorbent article will be referred to as the longitudinal direction Y and the width direction X, respectively. When distinguishing between the folding direction and the opening direction regarding the longitudinal direction Y, they will also be referred to as the folding direction Y1 and the opening direction Y2.

[0011] A preferred embodiment of the individual package of the absorbent article according to the present invention will be described below with reference to the drawings.

[0012] 1 and 2, the individual package 30 of this embodiment includes a sanitary napkin 10 (hereinafter simply referred to as the napkin 10), which is an absorbent article, and a packaging sheet 20 that wraps the napkin 10 while it is folded in the longitudinal direction Y. The napkin 10 and the packaging sheet 20 are folded along the longitudinal direction Y, with the portion including the middle portion C of the napkin 10 in the longitudinal direction Y as a folding center portion 31, and individual packaging fold lines L1 and L2 as folding axes at the front and rear of the folding center portion 31. At this time, by folding the packaging sheet 20 on the outside, the napkin 10 is enclosed in the packaging sheet 20 and stored in the individual package 30. In this embodiment, the stacked portions of the sanitary napkin 10 and the packaging sheet 20 before and after the central folded portion 31 are referred to as the first folded end portion 32 and the second folded end portion 33. In addition, the packaging sheet 20 is divided into a central packaging portion 21, a first folded packaging portion 22, and a second folded packaging portion 23 in accordance with the divisions of the central folded portion 31, the first folded end portion 32, and the second folded packaging portion 23. In this embodiment, the first folded end portion 32 overlaps the central folded portion 31, and the second folded end portion 33 overlaps on top of that. Similarly, in the packaging sheet 20, the first folded packaging portion 22 overlaps the central packaging portion 21, and the second folded packaging portion 23 overlaps on top of that. The individual packaging fold lines determine the number of times the absorbent article is folded, and as described above, can be set appropriately depending on the length of the absorbent article, the size of the individual package, etc. The folding order is not limited to the above-described form and can be set appropriately.

[0013] The individual packaging body 30 has a pair of side edge portions 34, 34 located outside the width direction X of the napkin 10 and along the longitudinal direction Y of the napkin 10, and each of these side edge portions 34 is a laminated portion of the packaging sheet 20 formed by the above-mentioned folding without the napkin 10 being interposed. By providing a plurality of fused portions 4 on these side edge portions 34, 34, the side edge portions 34, 34 form a sealed area that seals the individual packaging body 30 in the direction perpendicular to the individual packaging fold lines L1 and L2, i.e., along the longitudinal direction Y of the napkin 10. This prevents foreign matter from entering from outside. Each fused portion 4 is a portion where sheets are joined together by partially melting the packaging sheet 20, and can be formed by a method commonly used for this type of product, such as heat embossing or ultrasonic embossing. Each fused portion 4 is formed, for example, in a dot shape, and its planar shape can be various shapes as long as it has the configuration and functions described below. From the perspective of improving the prevention of foreign matter from entering from the outside, it is preferable that each of the fused portions 4 be arranged at equal intervals in the extension direction of each of the side edge portions 34, 34 (the direction along the longitudinal direction Y of the absorbent article). Similarly, it is preferable that each of the side edge portions 34, 34 has multiple rows of the above-mentioned fused portions 4.

[0014] The individual package 30 has a first surface 30A at which an opening edge 35 of the packaging sheet 20 located at one end side of the napkin 10 in the longitudinal direction Y is exposed, and a second surface 30B located opposite the first surface 30A and exposed. Here, the one end side of the napkin 10 in the longitudinal direction Y refers to the side of the folded end that is the outermost layer in the layered structure in which the napkin 10 is folded and both ends in the longitudinal direction Y are overlapped. In this embodiment, the one end side of the napkin 10 in the longitudinal direction Y is included in a second folded end 33 defined by an individual packaging fold line L2. The end of the second folded packaging portion 23 of the packaging sheet 20 included in the second folded end 33 is exposed as the opening edge 35 of the individual package 30. The surface at which the opening edge 35 of the second folded end 33 is exposed is the first surface 30A, and the opposite surface at which the folded central portion 31 is exposed is the second surface 30B.

[0015] In such an individual package 30, the opening edge 35 extends along the width direction X of the napkin 10 and includes parts of both side edges 34. In other words, the both side edges 34 include parts of the opening edge 35 (specifically, both side portions). When opening the individual package 30, the opening edge 35 is pulled up and in the longitudinal direction Y of the napkin 10, i.e., in the opening direction Y2 opposite to the folding direction Y1 of the individual package 30. This causes the fusion of the multiple fused portions 5 of the both side edges 34 extending along the longitudinal direction Y to peel, opening the individual package 30 and exposing the napkin 10 inside. In terms of ease of opening, a tab tape 39 may be arranged in this individual package 30 so as to straddle the opening edge 35 in the folding direction Y1.

[0016] The individual package 30 has a topmost stacked region 36, which includes the opening ends 35 of both side edges 34, 34, and in which the packaging sheets 20 are stacked without a napkin 10 in between. This topmost stacked region 36 is a region including the opening ends 35 of both side edges 34, 34, and is located between minimum stacked regions 37, which have the fewest number of stacked packaging sheets 20, and is a region in which the number of stacked packaging sheets 20 is greater than that of the minimum stacked region 37. The number of stacked packaging sheets 20 in the topmost stacked region 36 may be a single type or may include multiple types, as long as it exceeds the number of stacked packaging sheets 20 in the minimum stacked region 37. For example, in the embodiment shown in FIG. 3(A), in a cross section along the extension direction of the side edges 34 (the direction along the longitudinal direction Y of the napkin 10), the minimum stacked regions 37, 37 have two stacked packaging sheets 20, while the region between them, which includes the opening end 35, is the topmost stacked region 36, which has three stacked packaging sheets 20. Specifically, the highest stacking region 37 is a region where the central packaging section 21, the first folded packaging section 22, and the second folded packaging section 23 of the packaging sheet 20 are stacked. In the embodiment shown in Fig. 3(B), the highest stacking region 36 including the opening edge 35 between the minimum stacking regions 37, 37 includes two different numbers of stacked packaging sheets 20: three and four. Specifically, the highest stacking region 36 includes two types: a three-sheet stacking region where the central packaging section 21, the first folded packaging section 22, and the second folded packaging section 23 of the packaging sheet 20 are stacked, and a four-sheet stacking region where the leading edge of the second folded packaging section 23 is further folded back. The number of stacked packaging sheets 20 in this highest stacking region 36 can be set variously as long as it satisfies the above requirements, and is set appropriately depending on the number of times the packaging sheet 20 is folded.

[0017] Furthermore, the individual package 30 has a colored band region 5 on the first surface 30A side, which is located within the width (length) range along the longitudinal direction Y of the napkin 10 in the uppermost stacked region 36 as a region including the opening end 35 of each side edge 34, 34, and has a color that is distinct from its surroundings. This colored band region 5 may be located in a range that covers the entire width (length) of the uppermost stacked region 36 along the longitudinal direction Y of the napkin 10, as a region that satisfies the above requirements, or may be located in a range that covers only a portion of the width (length) of the napkin 10 along the longitudinal direction Y. Furthermore, the colored band region 5 may remain at each side edge 34, 34 where the uppermost stacked region 36 is located, or may extend beyond each side edge 34, 34 further inward in the width direction X. In the example shown in FIG. 1 , the colored band region 5 is disposed across the entire width direction X of the individual package 30. However, this is not limited to this, and the colored band region 5 may also extend partially inward in the width direction X from each side edge 34, 34 (not shown).

[0018] The colored band region 5 can have various colors as long as it is different from the surrounding area. This color includes chromatic colors as well as achromatic colors such as gray and black. The colored band region 5 arranged on the first surface side 30A of the packaging sheet 20 can be formed by a method commonly used for this type of product. For example, it can be formed by flexographic printing, gravure printing, inkjet printing, etc. using pigments or dyes.

[0019] The colored band regions 5 of both side edges 34, 34 include a plurality of the aforementioned fused portions 4. Each fused portion 4 located in the colored band regions 5 of both side edges 34, 34 has a first fused portion 6 in which a plurality of stacked packaging sheets 20 are continuously and integrally bonded, and a second fused portion 7 surrounding the first fused portion 6 (FIGS. 4(A) and 4(B)). In the first fused portion 6, "continuous" bonding means that the packaging sheets 20 are bonded without any unbonded portions across the entire planar area of ​​the first fused portion 6. "Integral" bonding means that the entire laminated structure of the packaging sheets 20 is bonded across the thickness direction of the first fused portion 6. By continuously and integrally bonding the packaging sheets 20 across the first fused portion 6, a uniform fused structure without any unbonded portions is achieved across the planar area and thickness direction. Such a first fused portion 6 plays a dominant role in bonding between the packaging sheets 20 in the fused portion 4 arranged in the colored band regions 5.

[0020] The first fused portion 6 and the second fused portion 7 are distinguished by the intensity of their colors, and in a plan view from the first surface 30A side, the first fused portion 6 is darker in color than the second fused portion. In other words, the second fused portion 7 surrounding the first fused portion 6 is lighter in color than the first fused portion 6 (or may be uncolored). Therefore, the color of the second fused portion 7 is lighter than the color of the colored band region 5 outside the fused portion 4 in the planar direction. As a result, as shown in FIGS. 4(A) and 4(B) , on the first surface 30A side of the colored band region 5, the fused portion 4 is distinguished by the difference in color between the second fused portion 7 and its outer region. Within the fused portion 4 defined by the difference in color, the first fused portion 6 is defined as the darkest color among the regions on the first surface 30A side of each fused portion 4 and as the region that bonds the packaging sheet 20 continuously and integrally in the thickness direction Z, and plays a dominant role in the bonding of the fused portion 4. The second fused portion 7 is defined as a portion within the area of ​​each fused portion 4 excluding the first fused portion 6. In the second fused portion 7, it is preferable that the plurality of packaging sheets 20 are spaced apart from each other in a portion adjacent to the outer edge of the fused portion 4. A preferred embodiment of the fused structure of the second fused portion 7 will be described later.

[0021] As described above, the first fused portion 6 is surrounded by the lighter-colored second fused portion 7. As a result, in a plan view from the first surface 30A side of the individual packaging body 30, the first fused portion 6 is framed by the lighter-colored second fused portion 7, improving visibility within the colored band region 5.

[0022] (Method of measuring color intensity) The color density is expressed as a percentage of the area occupied by the halftone dots that make up the colored portion (printed portion) of the image, as shown below. (1) In the individual package 30, a sample piece measuring 10 mm x 10 mm is cut out from the colored band region 5 on the side edge portion 34 of the packaging sheet 20 at a location having multiple fused portions 4. An image of the sample piece in plan view is taken using an optical microscope (for example, VHX-6000 (product name) manufactured by Keyence Corporation). The observation magnification is 200x. (2) In the captured image, the first fused portion 6 and the second fused portion 7 are defined (as described below), and the proportion of the area occupied by the dotted area in each fused portion is calculated as a percentage. (3) The dot density is measured at three different locations according to (1) and (2) above, and the average value is calculated to determine the dot density of each of the first fused portion 6 and the second fused portion 7.

[0023] (Method of defining first fused portion 6 and second fused portion 7 in plan view from first surface 30A side) (1) On the first surface side of each fused portion 4, trace the boundary of the continuous, integrated area with the darkest color in the fused portion 4 using a line drawing tool attached to the optical microscope. The area within the traced boundary is defined as the area on the first surface 30A side of the first fused portion 6. (2) Next, the boundary of the area on the first surface 30A side of the fused portion 4 is defined, and the area excluding the area of ​​the first fused portion 6 is regarded as the area on the first surface 30A side of the second fused portion 7. For example, in the example shown in Figure 5(A), the area on the first surface 30A side of the fused portion 4 is shown as the area surrounded by boundary D1, which is its outer edge, and the area on the first surface 30A side of the first fused portion 6 is shown as the area surrounded by boundary D2, which is its outer edge. In the above-described classification method, the boundary D1 of the region on the first surface 30A side of the fused portion 4 can be identified by tracing the boundary between the colored band region 5 and a region that is relatively lighter in color than the color of the colored band region 5 or is uncolored using a line drawing tool attached to an optical microscope. In this case, if the drawn boundary D1 advances from the basic direction of travel V1 to the counter-direction of travel V2 and forms a curve that is convex in the counter-direction of travel V2 (for example, the dashed-dotted line E1 in FIG. 6(B), which is a partial enlargement of FIG. 6(A)), a straight line parallel to the basic direction of travel V1 is drawn from point Q1 before advancing to point Q2 where it intersects with the boundary of the relatively lighter-colored or uncolored region (for example, boundary D1 shown in FIG. 6(C)). The drawing continues from there.

[0024] Furthermore, the second fused portion 7 has a recess 71 recessed in the thickness direction Z in the portion exposed on the first surface 30A side (see, for example, FIGS. 7A and 7B). The shadow effect of the recess 71 in the second fused portion 7 makes the darker first fused portion 6, which is located further back toward the second surface 30B than the second fused portion 7, appear to stand out more three-dimensionally. This significantly enhances the visibility of the first fused portion 6, which plays a dominant role in the bonding of each fused portion 4. This results in extremely high visibility that cannot be achieved simply by changing the color shade alone (see, for example, FIG. 4). Therefore, even if the first fused portion 6 has the same color as the colored band region 5 outside the fused portion 4, the user can reliably recognize the presence of the first fused portion 6.

[0025] From the viewpoint of the emotional quality of the colored band region 5 and the first fused portion 6 in the individual packaging body 70, it is preferable that the first fused portion 6 and the colored band region 5 outside the fused portion 4 are the same color or a similar color. Considering that the emotional quality of the individual packaging body 70 is expressed by the colored band region 5 and the region other than the colored band region 5, the emotional quality of the individual packaging body 70 can be enhanced by not giving the first fused portion 6 a color that is significantly different from the colored band region 5. Specifically, the difference in color is represented by the color difference ΔE measured as follows, and from the above viewpoint, the value of the color difference ΔE between the first fused portion 6 and the colored band region 5 is preferably 20 or less, more preferably 15 or less, and even more preferably 13 or less. In this specification, "the same color" means that the color difference ΔE between the two is 5 or less.

[0026] (How to measure color difference) The difference between two colors is expressed by the "color difference ΔE" as shown below. Color difference ΔE is the L standard standard established by the International Commission on Illumination (CIE) in 1976. * a * b * Color system (CIE1976(L) * a * b * ) color system) * , chromaticity b * and lightness L * It is calculated by the following formula (1). * , Δa * , Δb * is the L between two contrasting points in the hue space. * value, a * value, b * The difference between each value is shown. ΔE={(ΔL * ) 2 +(Δa * ) 2 +(Δb * ) 2} 1 / 2 (1) Specifically, the color difference ΔE can be measured using a color difference meter (for example, SE-2000 manufactured by Nippon Denshoku Industries Co., Ltd.). The measurement conditions are a reflection measurement method with a luminous flux of 30 mmφ, and a standard white calibration plate (L * =98.59, a * =0.55, b *=0.36), measurement of the sample piece is started. Note that, in order to satisfy the minimum area required for color difference measurement, the sample piece may be measured using a color-printed image of the sample piece taken by an optical microscope (for example, Keyence VHX-6000) enlarged and captured using a printer (for example, Ricoh Color Basic) with predetermined colored inks (for example, Ricoh Corporation MP P Toner Cyan C6003, Yellow C6003, Magenta C6003, Black C6003).

[0027] In the measurement methods for the color intensity and color difference described above, the color intensity represents the area ratio of the colored portion to the total area of ​​the sample (the halftone dot density described above), and the color difference represents the difference between two types of coloring.

[0028] The color of the second fused portion 7 may be similar to or different from the color of the first fused portion 6. It may also be uncolored, or may be a mixture of colored and uncolored portions. When the second fused portion 7 has a mixture of colored and uncolored portions, the colored portions may be the same color as or similar to the color of the first fused portion 6, or may be a different color. From the viewpoint of improving the visibility of the first fused portion 6, it is preferable that the color of the second fused portion 7 is a different color from that of the first fused portion 6, or is uncolored, or a mixture of colored and uncolored portions. In this case, the difference in color difference ΔE between the first fused portion 6 and the second fused portion 7 is preferably 25 or more, more preferably 30 or more, and even more preferably 35 or more. When a color similar to that of the first fused portion 6 is used as the color of the second fused portion 7, the color difference ΔE between the first fused portion 6 and the second fused portion 7 can be set to the above-mentioned preferable value by adjusting the halftone dot density, etc. In this case, the portions with halftone dots correspond to colored portions, and the portions without halftone dots correspond to non-colored portions.

[0029] Furthermore, since the first fused portion 6 and the second fused portion 7 having the above-described configuration are present in the colored band region 5 that includes the opening end 35 and is located within the range of the uppermost layered region 36, the first fused portion 6 can be reliably seen just before opening the individual package 30. This reliably gives the user a visual sense of security regarding the sealing performance and the resulting ability to prevent foreign matter from entering the absorbent article (hygienic performance). Furthermore, this high visibility visually communicates to the user the peel force required to open the uppermost layered region 36, helping to ensure a smooth and appropriate opening operation.

[0030] As shown in FIGS. 7A and 7B , the recess 71 of the second fused portion 7 is a recessed portion from the first surface 30A toward the second surface 30B in a cross-sectional view taken along the thickness direction Z of the fused portion 4. More specifically, the recess 71 has a bottom recessed toward the second surface 30B from the surrounding area within the region of the second fused portion 7 defined by the boundary D2 between the second fused portion 7 and the first fused portion 6 and the boundary D1 between the fused portion 4 and the colored band region 5 on the first surface 30A. From the viewpoint of enhancing the visibility, it is preferable that such a recess 71 be located in a region indicated by a border line having a minimum point in a cross-sectional view. Furthermore, from the viewpoint of ease of opening, it is preferable that such a recess 71 be formed only in the topmost packaging sheet 20 on the first surface 30A in the layered structure of the packaging sheets 20 constituting the uppermost stacked region 36.

[0031] Additionally, the area M1 of the first fused portion 6 when viewed from the first surface 30A is larger than the area M2 when viewed from the second surface 30B. The area M1 of the first fused portion 6 when viewed from the first surface 30A and the area M2 of the second surface 30B can be measured by applying the above-described method (method for determining the first fused portion 6 and the second fused portion 7 when viewed from the first surface 30A). That is, the area M1 can be determined and measured as the area of ​​the continuous, integrated region with the darkest coloring surrounded by the boundary D2 on the first surface 30A side, as shown in FIG. 5(A). The area M2 can be determined and measured as the area of ​​the continuous, integrated region with the darkest coloring surrounded by the boundary D3 on the second surface 30B side, as shown in FIG. 5(B).

[0032] The difference between the areas M1 and M2 is shown as a difference in the length of the border line, for example, as shown in Fig. 7(A) in a cross section in the thickness direction Z of the fused portion 4. In the cross section in the thickness direction Z along the width direction X of the first fused portion 6 shown in Fig. 7(A), the width N1 of the border line 62 defined by the boundary D2-boundary D2 on the first surface 30A side is longer than the width N2 of the border line 63 of the first fused portion 6 defined by the boundary D3-D3 on the second surface 30B side.

[0033] (Method of defining first fused portion 6 in cross section along thickness direction Z of fused portion 4) The first fused portion 6 in the cross section is defined by observing the fused portion 4 having the exposed cross section of the first fused portion 6 with an optical microscope at an inclination angle of 90° or 60° relative to the first surface 30A. In this case, the above-mentioned method (method for defining the first fused portion 6 and the second fused portion 7 in a plan view from the first surface 30A) is applied mutatis mutandis. That is, the area defined by connecting the four end points of the cross section that form the boundaries D2 and D3 of the areas with the darkest color is defined as the cross section of the first fused portion 6 along the thickness direction Z (for example, FIGS. 7(A) and (B)).

[0034] Thus, in the uppermost layer region 36 where the colored band region 5 is arranged, the area of ​​the continuous, integrally bonded portion of the entire laminated structure of the packaging sheet 20, which forms the first fused portion 6, is larger on the first surface 30A side than on the second surface 30B side. This means that the bonding strength between the laminated sheets is weakened from the first surface 30A side toward the second surface 30B side in the thickness direction Z of the first fused portion 6. This further improves the visibility of the first fused portion 6 from the first surface 30A side, and improves the openability of the individual package 30, which involves fusion peeling between the laminated sheets, while maintaining the necessary fused area. In other words, the individual package 30 is made easier to open near the opening edge 35 included in the colored band region 5.

[0035] The openability will be described with reference to FIG. Due to the difference between the areas M1 and M2 of the first fused portion 6, the fusion lengths (the widths N1 and N2) of the boundary D2 on the first surface 30A side and the boundary D3 on the second surface 30B side between the first fused portion 6 and the second fused portion 7 differ. Due to this difference (N1 > N2), the magnitude of the sum of the force vectors required to peel from the opening end 35 in the opening direction Y2 is smaller on the second surface 30B side than on the first surface 30A side, as shown by the arrows in FIG. 8 . Due to this difference in the magnitude of the sum of the force vectors, when an external force is applied for opening, peeling tends to proceed first on the second surface 30B side, which has a smaller area than on the first surface 30A side. In this case, as described above, the first fused portion 6 has a uniform fused structure that does not include unbonded portions in the planar region and thickness direction, which makes it easier for this mechanism to be realized reliably.

[0036] In an individual package 30 having a first fused portion 6 with such a fused structure, the user strongly recognizes the first fused portion 6, which has been enhanced in visibility as described above, on the first surface 30A side and begins opening by applying a peel force estimated based on the area M1 of the first fused portion 6 on the first surface 30A side. Then, peeling between the laminated sheets occurs first at the boundary D3 on the second surface 30B side, where peeling is possible with a smaller peel force than the first fused portion 6, and the peeling can proceed smoothly. Furthermore, because the area M2 of the first fused portion 6 on the second surface 30B side is reduced, the peeling time is short. Furthermore, the break created by the initial peeling from the second surface 30B side triggers peeling between the laminated sheets at the boundary between the first fused portion 6 and the second fused portion 7 to easily proceed in the thickness direction Z to the first surface 30A side. This peeling at the first fused portion 6 occurs successively at multiple fused portions 4 as the opening operation progresses. In this way, the individual package 30 can be opened smoothly and quickly from the opening end 35 in the opening direction X2 along both side edges 34, 34 having a plurality of fused portions 4, improving openability.

[0037] As described above, the individual packaging body 30 of this embodiment has the above structure, which simultaneously makes it easy to open near the opening end of the individual package and provides peace of mind that foreign matter will not get mixed in by improving the visibility of the fused portion.

[0038] In the individual packaging body 30, the fused portion 4 having the first fused portion 6 and the second fused portion 7 as described above may or may not be arranged in other areas of the side edge portions 34, 34, as long as it is in an area overlapping with the colored band area 5 of the side edge portions 34, 34. The fused portion 4, including the first fused portion 6 and the second fused portion 7, of the individual packaging body 30 can be formed by, for example, appropriately setting the difference in the area of ​​the tip of the embossed protrusion pressed from the first surface 30A and the area of ​​the tip of the embossed protrusion pressed from the second surface 30B, or by forming the embossed protrusion pressed from the second surface 30B into a double-convex shape, during the embossing process used for this type of product. The difference in color intensity between the first fused portion 6 and the second fused portion 7 can be achieved, for example, by selecting a colored ink that melts and moves easily from its fixed state to the packaging sheet in the heating temperature range to which the packaging sheet is subjected during embossing. That is, the colored ink selected in this manner melts in the region of the packaging sheet that will become the second fused portion before embossing, and the molten colored ink moves by gravity to the first fused portion, which is located deeper in the paper than the second fused portion. The migrated color ink aggregates with the melted color ink at the first fusion portion due to surface tension, and when the temperature returns to room temperature, it is fixed again at the position of the first fusion portion, thereby creating the difference in color intensity.

[0039] In the individual package 30, the ratio (K2 / K1 (see FIG. 3 )) of the length K2 of the colored band region 5 including the first fused portion 6 and the second fused portion 7 along the longitudinal direction Y to the length K1 of the uppermost layered region 36 along the longitudinal direction Y is preferably 0.10 or more, more preferably 0.20 or more, and even more preferably 0.25 or more, from the viewpoint of improving the visibility and the ease of opening near the opening end 35. In this embodiment, the length of the colored band region 5 along the longitudinal direction Y is shorter than that of the uppermost layered region 36 (K2 / K1>1), but the length of the colored region 5 along the longitudinal direction Y may be equal to or greater than the length of the uppermost layered region 36 along the longitudinal direction Y.

[0040] In the individual packaging body 30, from the viewpoint of further enhancing the aforementioned visibility, the ratio (S1 / S2) of the dot density S1 of the first fused portion 6 to the dot density S2 of the second fused portion 7 when viewed in a plane from the first surface 30A side is preferably 4.0 or more, more preferably 6.0 or more, and even more preferably 8.0 or more.

[0041] Furthermore, from the viewpoint of further enhancing the visibility, the depth of the recess 71 of the second fusion portion 7 from the surface of the first surface 30A of the colored band region 5 is preferably 80% or more of the depth of the colored band region 5 of the first fusion portion 6 from the surface of the first surface 30A of the colored band region 5, more preferably 90% or more, and even more preferably 100% or more. Furthermore, from the viewpoint of ease of opening, the depth of the recess 71 of the second fusion portion 7 from the surface of the first side 30A of the colored band region 5 is preferably 160% or less of the depth of the first fusion portion 6 from the surface of the first side 30A of the colored band region 5, more preferably 150% or less, and even more preferably 140% or less.

[0042] (Method of measuring depth from the surface of the colored band region 5 on the first surface 30A side) (1) A cross section of the object to be measured (first fused portion 6 or second fused portion 7) located in the colored band region 5 as shown in Figure 7 is observed with an optical microscope equipped with a line drawing tool (e.g., Keyence optical microscope "VHX-6000"), and parallel lines in the width direction are drawn passing through a point located on the surface of the packaging sheet 20 nearest to the first side 30A where no fused portion is formed, using the line drawing tool (e.g., software named "VHX-6000 Software" that comes standard with the Keyence optical microscope "VHX-6000"). (2) Using the widthwise parallel line as a reference, select a point on the measurement object (recess 71 of first fused portion 6 or second fused portion 7) that is furthest from the widthwise parallel line, connect the widthwise parallel line and the selected point with a straight line parallel to the thickness direction, and measure the length of the straight line using a two-point distance measurement tool (for example, the software named "VHX-6000 Software" that comes standard with the Keyence optical microscope "VHX-6000"). (3) The above steps (1) and (2) are performed on ten different second fused portions 7 located in the colored band region 5, and the average value of these measurements is taken as the depth to be measured.

[0043] In order to further enhance the visibility of the individual packaging body 30, it is preferable that the recesses 71 of the second fused portion 7 are arranged along the outer edge of the first fused portion 6 in a plan view from the first surface 30A side. For example, when the first fused portion 6 is rectangular as shown in Fig. 9, the recesses 71 of the second fused portion 7 are arranged along the four sides defined by a boundary D2 that is the outer edge of the first fused portion 6. It is preferable that the recesses 71 are arranged to extend along the four sides of the first fused portion 6 in four regions 7A, 7B, 7C, and 7D of the second fused portion 7 shown in Fig. 9. This further enhances the visual effect of the shadow created by the recess 71 of the second fused part 7, and makes the boundary D2 of the first fused part 6, which is recessed further towards the second surface 30B than the second fused part 7, more clear to the user. In other words, the visibility of the first fused part 6 from the first surface 30A side is further improved.

[0044] Similarly, the recesses 71 of the second fused portion 7 preferably have a structure extending from the outer edge of the first fused portion 6 to the outer edge of the fused portion 4 in a plan view from the first surface 30A side. For example, when the first fused portion 6 is square as shown in Fig. 9, the recesses 71 may extend radially in all directions from a boundary D2, which is the outer edge of the first fused portion 6, along the four corners of the first fused portion 6 to a boundary D1, which is the outer edge of the fused portion 4. It is preferable that the recesses 71 extend radially to the boundary D2 in the four corner regions 7E, 7F, 7G, and 7H of the second fused portion 7 shown in Fig. 9. This creates a visual effect of shadows created by the recesses 71 of the second fused portion 7, making the central side of the first fused portion 6 appear to be raised, further improving the visibility of the first fused portion 6 from the first surface 30A side.

[0045] In the individual packaging body 30, from the viewpoint of further enhancing the above-mentioned visibility, it is preferable that the area M1 of the first fused portion 6 is larger than the area M3 of the second fused portion 7 when viewed in plan from the first surface 30A side. This further enhances the visibility of the first fused portion 6 from the first surface 30A side. As described above, this area can be measured by applying the above-mentioned method (method for determining the first fused portion 6 and the second fused portion 7 when viewed in plan from the first surface 30A side) mutatis mutandis.

[0046] In the relationship of area M1 of the first fusion portion 6 > area M3 of the second fusion portion 7, from the viewpoint of further improving the visibility mentioned above, the ratio (M1 / M3) of area M1 of the first fusion portion 6 to area M3 of the second fusion portion 7 is preferably 1.3 or more, more preferably 1.5 or more, and even more preferably 2.0 or more. Furthermore, from the viewpoint of ensuring the visibility of the first fusion portion 6 by the presence of the second fusion portion 7 surrounding the first fusion portion 6, the ratio (M1 / M3) of the area M1 of the first fusion portion 6 to the area M3 of the second fusion portion 7 is preferably 7.0 or less, more preferably 6.5 or less, and even more preferably 6.0 or less.

[0047] Furthermore, in order to further improve the aforementioned ease of opening the individual packaging body 30, the ratio (M1 / M2) of the area M1 on the first surface 30A side of the first fused portion 6 to the area M2 on the second surface 30B side is preferably 1.3 or more, more preferably 1.5 or more, and even more preferably 2.0 or more. In addition, from the viewpoint of ensuring sealing properties, the ratio (M1 / M2) of the area M1 on the first surface 30A side of the first fused portion 6 to the area M2 on the second surface 30B side is preferably 7.0 or less, more preferably 6.5 or less, and even more preferably 6.0 or less.

[0048] From the viewpoint of further improving the aforementioned ease of opening, it is preferable that the first fused portion 6 has an outer edge consisting of an inwardly curved curve 61 as shown in Fig. 10(A) when viewed from the second surface 30B side. In addition, in each of the regions 6A, 6B obtained by equally dividing the region on the second surface 30B side of the first fused portion 6 in half along the longitudinal direction Y of the napkin 10, it is preferable that the inwardly curved curves 61, 61 have two or more intersections 61P, and that the angle θ formed by the curves 61, 61 constituting each intersection 61P is less than 45°. This allows the separation between the laminated sheets at the boundary D3 between the first fused portion 6 and the second fused portion 7 on the second surface 30B to occur in stages, and allows the separation to be achieved with less force, further improving the ease of opening the individual package 30. More specifically, as shown in FIG. 10(B), when an external force W is applied along the tearing direction Y2 to the inwardly curved curve 61 that forms the boundary D3, an internal force (stress) B is generated in the opposite direction. The magnitude of the boundary-facing component B1 (the component perpendicular to the boundary B3) constituting the internal force B is B sin θ, based on the angle θ at the intersection 61P. B sin θ corresponds to the magnitude of the force required to peel the boundary D3 between the first fused portion 6 and the second fused portion 7 on the second surface 30B side. By satisfying the condition 0°<θ<45°, this is kept within the range of the following formula (2). As a result, peeling between the laminated sheets at the boundary D3 with a smaller force than B sin θ is possible. Furthermore, B sin θ is designed to gradually increase along the curve 61. This allows for faster peeling with a smaller force at the start of peeling, facilitating smooth peeling across the gradually expanding fused area. In order to more reliably improve the ease of opening the individual packaging body 30 by such rapid peeling at the start of peeling, it is preferable that the above-mentioned angle θ requirement be met at least in the region 6A on the peeling start side of the two equal regions 6A and 6B.

[0049]

number

[0050] In order to make the angle θ between the curves 61 and 61 more effective, the angle θ is more preferably 40° or less, and even more preferably 35° or less. The angle θ is preferably 0° or more, and the larger the better.

[0051] In order to make the above-mentioned peeling action in the first fused portion 6 more effective, the second fused portion 7 preferably has the following fused structure in the thickness direction Z. 11, the second fused portion 7 preferably has a sheet assembly 72 in which the multiple packaging sheets 20 in the uppermost stacked region 36 are spaced apart in the thickness direction Z, and a joined portion 73 adjacent to the sheet assembly 72 and in which the multiple packaging sheets 20 are fused (joined) continuously and integrally in the thickness direction Z without any boundaries. The sheet assembly 72 is located closer to the boundary D1 and is the first part of the fused portion 4 to be subjected to an external force for peeling when opening. As a result, the sheet assembly 72 is the first to be subjected to the external force that reaches the fused portion 4, and a force that quickly widens the distance between the packaging sheets 20 acts on the joined portion 73, while the joined portion 73, being fused and formed itself, acts as an internal force that opposes the external force and tries to remain in its current position, and ultimately this pair of forces acts as a tearing force in the thickness direction. As a result, during the peeling operation starting from the opening edge 35 of the uppermost layer in the colored band region 5, the external force for peeling is transmitted to the boundary D4 on the second surface 30B side between the joint portion 73 and the first fused portion 6 via the uppermost layer of the sheet assembly 72. As a result, the above-mentioned peeling starting from the second surface 30B side of the first fused portion 6, which has a smaller area than the first surface 30A (peeling starting from the boundary D4 between the joint portion 73 and the first fused portion 6 on the second surface 30B side of the fused portion 4) is more likely to occur smoothly.

[0052] The boundary D4 between the joint 73 of the second fused portion 7 and the first fused portion 6 in the cross section in the thickness direction Z can be determined by applying the above-mentioned "Method for determining the first fused portion 6 and the second fused portion 7 in a plan view from the first surface 30A side" and "Method for determining the first fused portion 6 in a cross section in the thickness direction Z." Specifically, the boundary D4 is determined as follows. Based on the difference in color density between the first fused portion 6 and the second fused portion 7 in an optical microscope image of the cross section, the frame line of the second fused portion 7 on the first surface 30A side and the frame line of the second surface 30B side of the packaging sheet 20 closest to the second surface 30B are traced and connected. Then, straight lines parallel to the thickness direction are drawn, intersecting the two frame lines. The area surrounded by the two frame lines and the straight lines is defined as the joint 73 of the second fused portion 7 (the area on the first fused portion 6 side). The boundary where the color intensity differs at the intersection of the bonded portion 73 and the second surface 30B side of the first fused portion 6 is defined as boundary D4. In this case, the line is defined so that the bonded portion 73 of the second fused portion 7 is (i) colored in a lighter color than the first colored portion 6 (or is not colored at all), and (ii) is defined as a region that is continuously and integrally fused (bonded). If the line cannot be defined so as to satisfy requirement (ii), it is considered that the bonded portion 73 does not exist.

[0053] In the above classification, the second fused portion 7 is defined in a cross section in the thickness direction Z, for example, as shown in Figure 11, by a frame line 74 extending from the surface of the first surface 30A of the packaging sheet 20 (second folded packaging portion 23) located closest to the first surface 30A, a frame line 75 extending from the surface of the second surface 30B of the packaging sheet 20 (central packaging portion 21) located closest to the second surface 30B, and a straight line 76 parallel to the thickness direction Z passing through boundary D1. In this case, the recess 71 is a portion defined by a part of the frame line 74 on the first surface 30A side. Boundary D4 between the joint portion 73 and the first fused portion 6 is included on the line connecting these frame lines 74 and 75. As described above, the joint portion 73 is a portion where the plurality of packaging sheets 20 are fused (bonded) continuously and integrally without boundaries in the thickness direction Z. The joint portion 73 defined in this manner is defined in a cross section in the thickness direction Z by a frame line 74 on the first surface 30A side, a frame line 75 on the second surface 30B side, and a straight line 77 parallel to the thickness direction Z, as shown in Fig. 11, for example.

[0054] With regard to the connection portion between the joining portion 73 of the second fused portion 7 and the first fused portion 6, it is preferable to do as follows from the viewpoint of further improving the ease of opening. 12, in a cross-sectional view of the fused portion 4 in the thickness direction Z, the angle γ formed by the tangent T1 to the frame line 78 of the joining portion 73, which passes through the intersection 67P between the joining portion 73 of the second fused portion 7 and the frame line 63 on the second surface 30B side of the first fused portion 6, and the thickness direction parallel line T2 is preferably less than 45°. This increases the distance between the first fused portion 6 and the frame line 78 of the second fused portion 7 before opening, making peeling from the second surface 30B side even more likely to occur, further improving the ease of opening.

[0055] In order to make the effect of the angle γ formed between the tangent T1 of the frame line 78 and the thickness direction parallel line T2 more effective, the angle γ is more preferably 35° or less.

[0056] 13 , it is preferable that the average thickness H1 of the first fused portion 6 is smaller than the average thickness H2 of the packaging sheet 20 of the second fused portion 7, and that the average density J1 of the first fused portion 6 is higher than the average density J2 of the second fused portion 7. This shortens the length of the boundary between the first fused portion 6, which plays a dominant role in the bonding properties of each fused portion 4, and the second fused portion 7 (the boundary in the thickness direction connecting the boundary D2 and the boundary D3 in the thickness direction), and the difference in average densities between the first fused portion 6 and the second fused portion 7 makes peeling at the boundary between the first fused portion 6 and the second fused portion 7 even more likely, thereby further improving the ease of opening. As shown in the measurement method below, the average thickness H1 of the first fused portion 6 is the average thickness of the entire fused portion that is continuously and integrally bonded, and the average thickness H2 of the packaging sheet 20 of the second fused portion 7 is the average thickness of the packaging sheet 20 located closest to the first surface 30A.

[0057] (Method of measuring average thickness H1 of first fused portion 6) (1) The cross section of the fused portion 4 of the side edge 34 of the individual package 30 is observed with an optical microscope (for example, VHX-6000 (product name) manufactured by Keyence Corporation), and an image is taken. (2) Next, using two-point distance measurement software (for example, VHX-6000 Software manufactured by Keyence Corporation), the thickness of the first fused portion 6 is measured at 10 points, and the average value is calculated. (3) The above steps (1) and (2) are carried out on 10 different fused portions, and the average value of the values ​​calculated in the above step (2) is set as the average thickness H1 of the first fused portion 6.

[0058] (Method of measuring average thickness H2 of packaging sheet 20 at second fused portion 7) (1) The cross section of the fused portion 4 of the side edge 34 of the individual package 30 is observed with an optical microscope (for example, VHX-6000 (product name) manufactured by Keyence Corporation), and an image is taken. (2) Next, using two-point distance measurement software, the maximum thickness H2 of the packaging sheet 20 located closest to the first surface side among the plurality of packaging sheets 20 spaced apart in the sheet assembly 72 other than the joint portion 73 in the second fusion portion is measured. max and minimum thickness H2 min are measured and their average values ​​are calculated. (3) The above (1) and (2) are carried out for 10 different fused portions 4, and the average value of the values ​​calculated in the above (2) is set as the average thickness H2 of the packaging sheet 20 at the second fused portion 7.

[0059] (Method of measuring average density J1 of first fused portion 6 and average density J2 of second fused portion 7) The average density J1 of the first fused portion 6 is calculated by the following formula (3).

[0060]

number

[0061] The average density J2 of the second fused portion 7 is calculated by the following formula (4).

[0062]

number

[0063] From the viewpoint of improving the ease of opening, the ratio (H1 / H2) of the average thickness H1 of the first fused portion 6 to the average thickness H2 of the packaging sheet 20 of the second fused portion 7 is preferably 0.8 or less, more preferably 0.6 or less, and even more preferably 0.4 or less.

[0064] The ratio (J1 / J2) of the average density J1 of the first fused portion 6 to the average density J2 of the second fused portion 7 is preferably 2.0 or more, more preferably 3.0 or more, and even more preferably 4.0 or more, from the viewpoint of improving openability.

[0065] Furthermore, in order to further improve the visibility of the first fused part 6 and the ease of opening from the opening end 35, the individual package 30 preferably has at least one of the following configurations (1) to (4).

[0066] (1) When viewed from above from the first surface 30A, the first fused portion 6 is preferably darker in color than the area of ​​the colored band region 5 where the fused portion 4 is not disposed. This makes the color of the first fused portion 6 at the side edges 34, 34 the darkest in the colored band region 5, thereby increasing its visibility and allowing the user to more clearly visually recognize the sealing performance of the individual package 30. As a result, the user can be given an even greater sense of visual security regarding the hygienic performance of the napkin 10. As for the degree of difference in color intensity, when viewed in a plane from the first surface 30A side, the ratio (S1 / S3) of the dot density S1 of the first fused portion 6 to the dot density S3 of the area of ​​the colored band region 5 where the fused portion 4 is not arranged is preferably 1.3 or more, more preferably 1.5 or more, and even more preferably 2.0 or more. Moreover, from the viewpoint of improving the emotional appeal of the individual package 70, the ratio (S1 / S3) is preferably 8.0 or less, more preferably 7.0 or less, and even more preferably 6.0 or less.

[0067] (2) It is preferable that the colored band region 5 extends from the side edge portions 34, 34 where the first fused portion 6 and the second fused portion 7 are arranged to the inner region 51 in the width direction X. This makes it easier to find the opening end 35 in the region of the colored band region 5 where the fused portion 4 is not arranged, and makes it even easier to insert a finger at the opening end 35 to open the package.

[0068] (3) It is preferable that the region 51 (see FIG. 1 ) of the colored band region 5, which is located inward in the width direction X from the side edges 34, 34 where the first fused portion 6 and the second fused portion 7 are arranged, is lighter in color than the first fused portion 6. This color contrast makes it easier to find the opening edge 35 where the finger is inserted when opening, and makes the arrangement of the first fused portion 6 more visible. This makes it easier to achieve the effect of improving the ease of opening described above. As described above, the color contrast between the first fused portion 6 and the inner region 51 is expressed by the dot density. The difference in dot density between the two is preferably in the same range as the ratio of dot densities (S1 / S3) described above.

[0069] (4) The first fused portion 6 and the second fused portion 7 are preferably arranged along both side edges 34, 34 in the extending direction of the side edges 34, 34 (the direction along the longitudinal direction Y of the napkin 10) also in the outer region 38 (see FIG. 1) of the edge 5E of the colored region 5 opposite the opening end 35. This makes the color depth of the first fused portion 6 overlapping the colored band region 5 and the visual difference with the outer color more apparent in contrast with the first fused portion 6 in the outer region 38 not overlapping the colored band region 5. This makes it easier to achieve the aforementioned effect of improving the ease of opening.

[0070] The napkin 10 and the packaging sheet 20 constituting the individual packaging body 30 may be made of any material used for this type of article, without any particular restrictions.

[0071] The packaging sheet 20 can be made of various materials capable of forming the fused portion 4, without any particular restrictions. For example, it can be made of polyolefin polymer resins such as polyethylene resin and polypropylene resin. Examples of such materials include polyethylene [linear low-density polyethylene (L-LDPE), low-density polyethylene (LDPE)], polypropylene, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EA), styrene-isoprene copolymer (SIS), styrene-butadiene copolymer (SBS), olefin-based elastomers, and mixtures thereof.

[0072] The napkin 10 preferably has a topsheet on the skin contact side, a backsheet on the non-skin contact side, and an absorbent body disposed between the topsheet and the backsheet. The absorbent body can be any of a variety of forms commonly used in absorbent articles, without particular limitation. For example, it may be a hydrophilic fiber stack or a mixed stack of hydrophilic fibers and a superabsorbent polymer material covered with a hydrophilic covering sheet. It may also be composed of a thin absorbent sheet in which a superabsorbent polymer material is sandwiched and fixed between two sheet-like fiber layers made of hydrophilic fibers. The absorbent sheet can be formed by utilizing the adhesive strength that the superabsorbent polymer material develops when wet, or by utilizing a binder such as a separately added adhesive or adhesive fiber. It can be produced by a variety of commonly used methods, including either a wet or dry method. The absorbent sheet has a thickness of 3.0 mm or less, and the highly absorbent polymer material is dispersed in the planar direction of the sheet, making it less susceptible to gel blocking and providing high absorption capacity. For example, the absorbent sheet is described in paragraphs

[0019] to

[0131] of JP-A-8-246395.

[0073] The hydrophilic fibers constituting the absorbent include those obtained by subjecting hydrophobic fibers to hydrophilic treatment and those that are hydrophilic themselves. In particular, those that are hydrophilic and have water-retaining properties are preferred. Examples of the latter hydrophilic fibers include natural fibers, regenerated cellulose fibers, and semi-synthetic fibers. Pulp and rayon are particularly preferred as hydrophilic fibers, with pulp being even more preferred. Furthermore, crosslinked cellulose fibers in which cellulose fibers are crosslinked intramolecularly and / or intermolecularly, and bulky cellulose fibers obtained by mercerizing wood pulp may also be used. Examples of pulp include, but are not limited to, wood pulp such as softwood kraft pulp or hardwood kraft pulp, and natural cellulose fibers such as cotton pulp and straw pulp. One or more of these pulps may be used.

[0074] Examples of superabsorbent polymer materials constituting the absorbent include hydrogel materials obtained by polymerizing water-soluble ethylenically unsaturated monomers, primarily composed of acrylic acid or acrylate salts, optionally with the addition of a crosslinking agent. Other examples include crosslinked products of polyethylene oxide, polyvinylpyrrolidone, sulfonated polystyrene, and polyvinylpyridine, saponified starch-poly(meth)acrylonitrile graft copolymers, starch-poly(meth)acrylic acid graft copolymers, and hydrolyzed starch-poly(meth)acrylic ester graft copolymers. These superabsorbent polymer materials can be used alone or in combination of two or more. The superabsorbent polymer material is preferably one that can absorb and retain at least 20 times its own weight in liquid and can gel. The shape of the superabsorbent polymer material is not particularly limited and may be any of the various shapes used for absorbents, such as spherical, granular, fibrous, bale-like, and block-like shapes.

[0075] Various liquid-permeable nonwoven fabrics can be used for the topsheet. Considering the pleasant feel, hydrophilic nonwoven fabrics are preferred, thermal-bonded nonwoven fabrics are more preferred, and air-through nonwoven fabrics are particularly preferred. Hydrophilized thermoplastic resin fibers are preferred, and the fibers are three-dimensionally crimped, such as secondary or tertiary crimps. Specifically, polyethylene, polypropylene, polyester, nylon, or composite fibers thereof are prepared and coated with various hydrophilizing agents before being cut to a predetermined length to form staples. Examples of hydrophilizing agents that can be used include various alkyl sulfonates, such as α-olefin sulfonates; acrylates; acrylate / acrylamide copolymers; ester amides; salts of ester amides; polyethylene glycol and its derivatives; water-soluble polyester resins; various silicone derivatives; various sugar derivatives; and mixtures thereof.

[0076] Various leak-proof materials can be used as the backsheet. For example, a moisture-impermeable or moisture-permeable film alone, a film bonded to a nonwoven fabric, or a water-repellent nonwoven fabric (SMS, SMMS, etc.) can be used. From the standpoint of cost and compatibility with anti-slip adhesives, it is most preferable to use a moisture-impermeable film alone as the leak-proof material. [Explanation of symbols]

[0077] 10. Sanitary napkins 20 Packaging Sheet 30 pieces package 30A 1st side 30B 2nd side 34 Side edge 35 Open end 36 Most laminated area 37 Minimum stacking area 4 Fusion part 5 Colored band area 6 1st fusion part 61 Inward Curve 61P intersection 6A, 6B: Regions obtained by dividing the second surface side of the first fused portion into two equal parts along the longitudinal direction of the absorbent article 62 Frame line on the first surface side of the first fused part 63 Frame line on the second side of the first fused part 7 Second fusion part 71 Recess 72 Sheet assembly 73 Joint 74 Frame line extending from the first surface of the packaging sheet located closest to the first surface 75 Frame line extending from the second surface of the packaging sheet located closest to the second surface X Width direction Y Longitudinal direction Y1 Folding direction Y2 Opening direction

Claims

1. An individual package for an absorbent article, comprising an absorbent article and a packaging sheet that wraps the absorbent article in a state where the absorbent article is folded in the longitudinal direction, The individual package has a plurality of fused portions that join the packaging sheets together on each of a pair of both side edge portions that are outward in the width direction of the absorbent article and along the longitudinal direction of the absorbent article, and has a first surface on which an opening end of the packaging sheet located on one end side of the longitudinal direction of the absorbent article is exposed, and a second surface that is exposed on the opposite side to the first surface, and the opening end extends along the width direction and includes the both side edge portions, The individual package has, as an area including the opening end of each of the side edge portions, a topmost stacking area in which the number of packaging sheets stacked without the absorbent article in between is greater than a minimum stacking area in which the number of packaging sheets is smallest, and a colored band area on the first surface side, which is located within a length range along the longitudinal direction of the absorbent article within the topmost stacking area and has a color that is distinguishable from its surroundings, The fused portions located in the colored band regions of the side edge portions have a first fused portion where the stacked packaging sheets are continuously and integrally bonded, and a second fused portion surrounding the first fused portion, the first fused portion has a darker color than the second fused portion in a plan view from the first surface side; the second fused portion has a recess recessed in a thickness direction in a portion exposed to the first surface side, In the first fused portion, an area in a plan view from the first surface side is larger than an area in a plan view from the second surface side. Individually packaged absorbent articles.

2. The individually packaged absorbent article according to claim 1 , wherein the recess of the second fused portion is arranged along an outer edge of the first fused portion in a plan view from the first surface side.

3. 3. The individual packaging body of an absorbent article according to claim 1, wherein the recess of the second fused portion has a structure extending from an outer edge of the first fused portion to an outer edge of the second fused portion when viewed in a plan view from the first surface side.

4. The individually wrapped absorbent article according to claim 1 or 2, wherein an area of ​​the first fused portion is larger than an area of ​​the second fused portion in a plan view from the first surface side.

5. 3. The individually packaged absorbent article according to claim 1, wherein, in a plan view from the second surface side, the first fused portion has an outer edge consisting of an inwardly curved curve, and in each region equally divided in half in a direction along the longitudinal direction of the absorbent article, the first fused portion has two or more intersections of the inwardly curved curves, and the angle between the curves constituting each of the intersections is less than 45°.

6. The individual packaging body of an absorbent article according to claim 1 or 2, wherein the second fused portion located in the uppermost layered region of each of the side edge portions joins the plurality of packaging sheets and has a joining portion that contacts the first fused portion.

7. 7. The individually packaged absorbent article according to claim 6, wherein in a fused portion located in the uppermost layered region of each of the side edge portions, in a cross-sectional view in the thickness direction, an angle formed between a tangent to a frame line of the fused portion, which passes through an intersection of the fused portion of the second fused portion and a frame line on the second surface side of the first fused portion, and a line parallel to the thickness direction is less than 45°.

8. 3. The individually packaged absorbent article according to claim 1, wherein in a cross-sectional view in the thickness direction, in the fused portion located in the uppermost layer region of each of the both side edges, the average thickness of the first fused portion is smaller than the average thickness of the packaging sheet of the second fused portion and the average density is higher than that of the packaging sheet of the second fused portion.

9. The individually packaged absorbent article according to claim 1 or 2, wherein the first fused portion has a darker color than an area of ​​the colored band region where the fused portion is not arranged, when viewed in a plan view from the first surface side.

10. The individually wrapped absorbent article according to claim 1 or 2, wherein the colored band regions extend from the side edge portions where the first fused portion and the second fused portion are arranged to inner regions in the width direction.

11. The individually packaged absorbent article according to claim 10, wherein the colored band region has a lighter color in the width direction than the side edge portions where the first fused portion and the second fused portion are arranged.

12. 3. The individual packaging body of an absorbent article according to claim 1 or 2, wherein the first fused portion and the second fused portion are also arranged along the both side edges in the extending direction of the both side edges in an outer region of the edge opposite the opening end in the colored band region.

Images