Individually packaged absorbent article

Abstract

In a separately packaged absorbent article in which an absorbent article is packaged by a paper packaging sheet, the packaging sheet is folded toward the inner surface side in the longitudinal direction of the packaging sheet, and both edge portions in the transverse direction perpendicular to the longitudinal direction are sealed to form a sealing portion. The packaging sheet is characterized in that a heat sealing agent is provided in at least a region included in the sealing portion of one of the inner surface and the outer surface of the packaging sheet, the packaging sheet is a sealing agent non-coated sheet or a sealing agent coated sheet, and the coating basis weight of the sealing agent is 10% or less with respect to the total weight per unit area of the packaging sheet after the heat sealing agent is provided.

Description

Technical Field

[0001] The present invention relates to individually packaged absorbent articles. Background Art

[0002] Most absorbent articles such as sanitary napkins, pantiliners, incontinence pads, etc. are individually packaged by a packaging sheet for reasons such as hygiene during storage and convenience during carrying, and are provided as individually packaged absorbent articles (individual packages) in a sealed state. As a packaging structure of an individually packaged absorbent article, for example, it is generally in the following form. An absorbent article is provided on the inner surface of a packaging sheet, and after folding the packaging sheet to the inner surface side together with the absorbent article, both edge portions are sealed.

[0003] As the material of the packaging sheet, resin films, non-woven fabrics, etc. are still the mainstream, but paper-made packaging sheets are also known. In the case of a paper-made packaging sheet, since the sheet material itself does not melt and adhere, efforts are required to improve the sealing strength of the sealed portion. For example, as described in Patent Document 1, a technique is disclosed in which both edge portions of a folded packaging sheet are pressed between a pair of rollers each having a first tooth row and a second tooth row meshing with the first tooth row on the surface, thereby forming a sealed portion.

[0004]

Prior Art Documents

[0005]

Patent Documents

[0006]

Patent Document 1

[0007]

Problems to be Solved by the Invention

[0008] However, even in the technique described in Patent Document 1, the sealing strength of the sealed portion is not much greater than that of a sealed portion formed by heat fusion. Therefore, the formation of a sealed portion using a hot melt adhesive is considered. At this time, the addition of a material such as a hot melt adhesive incurs additional costs. In view of this, it is desired to efficiently use the hot melt adhesive, that is, to more firmly form a sealed portion even with a smaller amount.

[0009] In view of the above, an object of one aspect of the present invention is to provide a technique for more firmly forming a sealed portion by heat sealing in an individually packaged absorbent article in which an absorbent article is packaged with a paper-made packaging sheet.

[0010]

Means for Solving the Problems

[0011] One aspect of the present invention is a separately-packaged absorbent article in which the absorbent article is packaged with a paper packaging sheet. The packaging sheet is folded inward on the inner surface side in the longitudinal direction of the packaging sheet, and both edge portions in the transverse direction perpendicular to the longitudinal direction are sealed to form a sealed portion. A heat-sealing agent is provided on at least the area including the sealed portion on one of the inner surface and the outer surface of the packaging sheet. The packaging sheet is a non-coated or coated sheet with a sealing agent, and the coating weight of the sealing agent is 10% or less with respect to the total unit area weight of the packaging sheet after the heat-sealing agent is provided.

[0012]

Effects of the Invention

[0013] According to one aspect of the present invention, in a separately-packaged absorbent article in which the absorbent article is packaged with a paper packaging sheet, the formation of the sealed portion based on heat sealing can be more firmly performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0014]

Figure 1

[0015]

Figure 2

[0016]

Figure 3

[0017]

Figure 4

[0018]

Figure 5

[0019]

Figure 6

[0020] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, in each drawing, unless otherwise specified, the same or corresponding structures may be given the same reference numerals and the description may be omitted.

[0021] <Basic Structure of Separately-Packaged Absorbent Article>

[0022] First, the basic structure of the separately-packaged absorbent article will be described. Figure 1 A plan view of the separately-packaged absorbent article 100 is shown in Figure 2 In Figure 1Plan view of the packaging sheet 10 of the individually packaged absorbent article 100 in the unfolded state, which is a view observed from the inner surface of the packaging sheet 10 or from the skin side of the absorbent article 1. In addition, Figure 3 is given in Figure 1 the cross-section taken along line I-I in Figure 4 and gives Figure 1 the cross-section taken along line II-II.

[0023] As Figures 1 to 4 shown, the individually packaged absorbent article 100 includes the packaging sheet 10 and the absorbent article 1 individually packaged by the packaging sheet 10.

[0024] (Packaging sheet)

[0025] As Figure 2 shown, the packaging sheet 10 can be in an elongated shape in the unfolded state, having a longitudinal direction (long side direction) D1 and a transverse direction (short side direction) D2 perpendicular to the longitudinal direction. In addition, the longitudinal direction D1 and the transverse direction D2 of the packaging sheet 10 can correspond to the long side direction and the short side direction of the absorbent article 1, respectively. In addition, the shape of the packaging sheet 10 is not limited to the rectangular shape as Figure 2 shown, and can have, for example, an oval shape.

[0026] In addition, the size of the packaging sheet 10 can be appropriately selected according to the size and shape of the packaged absorbent article 1. For example, in the state where the packaging sheet 10 is fully unfolded (unfolded state), the length of the longitudinal direction D1 (sometimes only referred to as the length) can be 100 to 450 mm, and the length of the transverse direction D2 (sometimes only referred to as the width) can be 70 to 250 mm.

[0027] The packaging sheet 10 in this embodiment is made of paper. By using a paper-made packaging sheet 10, it can contribute to plastic reduction and help achieve the sustainable development goals. In addition, paper can give a unique style, such as the appearance and feel of a soft impression of natural materials, and thus can provide a good mood to the user. In addition, in this specification, paper refers to a thin flat plate formed by gluing plant fibers and other fibers with an adhesive. In particular, it refers to the one with plant fibers as the main raw material. For example, among the fibers contained, plant fibers, especially cellulose fibers, are 50% or more, preferably 80% or more. Examples of plant fibers as raw materials for paper include wood pulp, non-wood pulp, ancient paper pulp, and cotton cellulose, and the pulp can be either mechanical pulp or chemical pulp. In addition, the above plant fibers can be regenerated fibers such as rayon and cuprammonium rayon, or plant fibers recycled from the structural components of the absorbent article and / or the packaging sheet for the absorbent article (recycled pulp, etc.).

[0028] Well-known paper additives such as clay, calcium carbonate, starch, latex, coloring pigments, and preservatives can be added to the paper. As examples of specific papers, various types of papers such as Western-style paper, Japanese paper, processed paper, and synthetic paper can be cited. Further, papers used in other applications in the past, for example, can be papers such as newspapers, printing papers (including high-quality papers), note papers, drawing papers, packaging papers, tissue papers, and mixed papers. In the case of tissue paper, it can be thin imitation paper, India paper, rice paper, glassine paper, facial tissue paper, toilet paper, filter paper, etc.

[0029] In addition, in this specification, a paper-made packaging sheet means a sheet mainly composed of the above-mentioned paper. Among paper-made packaging sheets, there are obviously packaging sheets composed only of paper, and laminated sheets formed by laminating sheets composed of paper and materials other than paper can also be included. When the packaging sheet 10 includes a sheet made of a material other than paper, the material other than paper can be a resin film, a non-woven fabric, etc. Here, when the packaging sheet 10 is not laminated with a sheet made of a material other than paper and is composed of paper, it is particularly preferred from the viewpoint of plastic reduction and / or the viewpoint of being able to impart the unique natural style of paper to the product.

[0030] The basis weight (grammage) of the packaging sheet 10 used in this embodiment is preferably 8 to 50 g / m 2 , more preferably 15 to 30 g / m 2 . By using the packaging sheet 10 with the basis weight within the above range, a single-packaged absorbent article with a good feel that suppresses a rough touch can be obtained, and the generation of sounds during carrying, opening, etc. can also be prevented. In addition, the thickness of the packaging sheet 10 (in the case of crepe paper, the thickness after creping processing) is preferably 30 to 200 μm, more preferably 35 to 100 μm. In addition, the basis weight of the above-mentioned packaging sheet is the basis weight of the packaging sheet in the unprocessed state, that is, the basis weight of the paper-made packaging sheet in the state where no sealing agent is coated and no heat-sealing agent is provided.

[0031] The paper packaging sheet 10 in this embodiment can be subjected to certain processing. This processing can include, for example, processing that applies physical deformation to the packaging sheet 10 such as corrugating, embossing, calendering, slitting, laminating, etc., and processing that adds substances to the packaging sheet 10 such as waterproofing, mold release, ink printing. Here, when performing the processing of adding substances, in order not to affect the sealing performance of the sealing part, it is preferably processed in an area other than the area where the heat-sealing agent (described in detail later) is coated, or in an area other than the area corresponding to the sealing part. In addition, the above-mentioned ink printing processing is preferably performed, for example, on the outer surface of the packaging sheet, whereby the design of the individually packaged absorbent article 100 is improved. When ink printing is performed on the packaging sheet 10, as the packaging sheet 10, it is preferably a material (non-wrinkled paper, non-embossed paper) that has not been subjected to processing such as corrugating and embossing to form unevenness on the surface of the packaging sheet.

[0032] (Absorbent article)

[0033] The absorbent article 1 packaged by the packaging sheet 10 can be an article in a flat and elongated shape that is worn in a manner facing the discharge port of body fluids (menstrual blood, vaginal secretions, urine, etc.). Specific examples of the absorbent article 1 can be sanitary napkins, pantiliners (vaginal secretion sheets), light incontinence pads, etc. The description in this specification is mainly based on the form taking a sanitary napkin as an example.

[0034] The absorbent article 1, for example Figure 2 As shown, it can have a liquid-permeable topsheet 3, a liquid-impermeable backsheet (not shown), and an absorbent body 4 provided between these topsheet 3 and backsheet.

[0035] As the backsheet, at least a water-blocking sheet such as an olefin resin sheet of polyethylene, polypropylene, etc. can be used. A laminated non-woven fabric obtained by laminating a non-woven fabric on a polyethylene sheet, etc., and a laminated sheet of a non-woven fabric that ensures substantial liquid impermeability through a waterproof film can also be used. In addition, a moisture-permeable one can be used.

[0036] As the topsheet 3, a perforated or non-perforated non-woven fabric, a porous plastic sheet, etc. are suitably used. As the material fibers constituting the non-woven fabric, for example, olefins such as polyethylene and polypropylene, synthetic fibers such as polyester and polyamide, regenerated fibers such as rayon and cuprammonium rayon, and their blended fibers, and natural fibers such as cotton can be used alone or in combination of two or more.

[0037] The absorbent body 4 is not limited as long as it is a material that can absorb and retain body fluids, but preferably contains cotton-like pulp and a water-absorbing polymer. As the water-absorbing polymer, superabsorbent polymer (SAP) powder, superabsorbent fiber (SAF), or a combination thereof can be used. As the pulp, examples include those composed of cellulose fibers such as chemical pulp and dissolving pulp obtained from wood, and artificial cellulose fibers such as rayon and acetate. As the pulp, hardwood pulp obtained from hardwood, softwood pulp obtained from softwood, or a mixed pulp thereof can be used. In addition, the pulp can be recycled pulp regenerated from used pulp.

[0038] The thickness of the absorbent body 4 can be 0.5 to 25 mm. The absorbent body 4 can have a structure in which a region corresponding to the body fluid discharge port (body fluid discharge port corresponding region) and a region behind the body fluid discharge port corresponding region, facing the groove of the buttocks, bulge. The absorbent body 4 has dimensions and a shape that do not exceed those of the top sheet 3 and the back sheet. Among the front and rear end edges of the absorbent body, the outer edges of the back sheet and the top sheet 3 are bonded by bonding means such as adhesives like hot melt adhesives, heat sealing, and ultrasonic sealing.

[0039] As Figure 2 shown, on the outside of the side portion of the absorbent body 4 (outside the lateral direction D2), side sheets 7, 7 can be provided along the longitudinal direction D1 at both ends in the lateral direction D2. As the side sheet 7, a non-woven fabric with waterproof treatment or a non-woven fabric with hydrophilic treatment can be used.

[0040] In addition, as Figures 1 to 4 shown in the example, the absorbent article 1 is a so-called wingless type without winglets, but it can also be configured as a winged article having winglets extending from the sides respectively. The winglets can be formed by bonding the side sheet and the back sheet.

[0041] In addition, on the back sheet side (non-skin side, i.e., the side facing the underwear when worn) of the absorbent article 1, an anti-offset adhesive portion can be provided to prevent the absorbent article 1 from shifting when installed on the underwear. The anti-offset adhesive portion can be formed into a plurality of bands extending in the longitudinal direction D1 or the lateral direction D2.

[0042] The overall length of the absorbent article 1 can be 140 to 430 mm, and the width of the absorbent article 1 (the width of the main body excluding the winglets when there are winglets) can be 40 to 130 mm.

[0043] (Packaging structure)

[0044] As Figures 1 to 4 shown, the absorbent article 1 is packaged by folding together with the packaging sheet 10, thereby forming a single-packaged absorbent article 100. When folding, asFigure 2 As shown, in the following state, the absorbent article 1 is placed on the inner surface of the packaging sheet 10, and the back sheet side of the absorbent article 1 faces the same. Then, the packaging sheet 10 and the absorbent article 1 are folded together to the inner surface side in the longitudinal direction D1 based on the first folding line F1 and the second folding line F2 along the lateral direction D2. More specifically, based on the first folding line F1, the first region R1 including one end 11 of the longitudinal direction D1 of the packaging sheet 10 is folded in the longitudinal direction D1, and based on the second folding line F2, the second region R2 including the other end 12 of the longitudinal direction D1 of the packaging sheet 10 is folded. The region between the first region R1 and the second region R2 of the packaging sheet 10 is the third region R3. In the illustrated example, the packaging sheet 10 is folded in such a way that the second region R2 is folded first and the first region R1 overlaps on the outer surface of the second region R2( Figure 1 and Figure 2 ), and the folding order of the first region R1 and the second region R2 can be reversed.

[0045] As Figure 1 and Figure 2 shown in the example, the packaging sheet 10 and the absorbent article 1 are triple-folded (inner triple-fold) together to wrap the absorbent article 1. Such a triple-folded packaging form can be formed relatively simply, the absorbent article 1 can be hygienically wrapped, and in addition, the absorbent article 1 can be easily taken out. In addition, the folding form is not limited to triple-fold, and can be four-fold or more (detailed later), or can be double-fold.

[0046] As Figures 1 to 4 shown in the triple-folded structure, in the region where the first region R1 and the second region R2 overlap, the packaging sheet 10 is three sheets overlapped, and in the region where the first region R1 and the second region R2 do not overlap, the packaging sheet 10 is two sheets overlapped. Figure 1 、 Figure 3 and Figure 4 show as follows, the region where the packaging sheet 10 is three sheets overlapped is the three-sheet overlapping region Zb, and the regions where the packaging sheet 10 is two sheets overlapped are the two-sheet overlapping regions Za1, Za2 (collectively Za).

[0047] After the packaging sheet 10 and the absorbent article 1 are folded together to wrap the absorbent article 1, both edge portions in the lateral direction D2 are sealed along the longitudinal direction D1 to form the sealing portions 15, 15( Figure 1 ). As Figure 1 shown, the sealing portions 15, 15 can be formed along the entire length of the longitudinal direction D1 of the packaging sheet 10. Through the sealing portions 15, 15, it is possible to prevent garbage, dust, or accidentally inserting fingers or small objects from the end edges in the lateral direction D2 into the individually packaged absorbent article 100 (to obtain encapsulation).

[0048] The sealing portion 15 can be formed within a range of 20 mm from the edge of the lateral direction D2. The sealing portion 15 can be formed along the entire range, or can be formed on a part within the above range, for example, at a position leaving some distance from the edge of the lateral direction D2. The length (width) of the sealing portion 15 in the lateral direction D2 itself can be 3 to 15 mm. In addition, as Figure 1 shown in the example, the contour inside the lateral direction D2 of the sealing portions 15, 15 is wavy, but it can also be that the contour inside the lateral direction D2 of the sealing portions 15, 15 is linear, and is formed along the longitudinal direction D1 with the same length (width) in the lateral direction D2.

[0049] In addition, in the single-packaged absorbent article 100, a fixing band 30 can be provided at the center in the lateral direction D2 so as to straddle one end 11 of the packaging sheet 10, that is, so as to straddle the first region R1 and the second region R2 on the outer surface of the single-packaged absorbent article 100. By having the fixing band 30, it is possible to prevent objects, fingers, etc. from entering between the first region R1 and the second region R2 and being pulled, and accidentally opening the seal before use. In addition, when opening the seal, the fixing band 30 can be held to lift the first region R1, so the opening operation is easy.

[0050] <Hot melt adhesive and heat sealing>

[0051] A hot melt adhesive is used in the formation of the sealing portions 15, 15 in the single-packaged absorbent article 100. The hot melt adhesive can contain a thermoplastic resin, preferably a resin that softens or melts at 70 to 170 °C, and preferably an olefin-based hot melt adhesive. In addition, the hot melt adhesive can be an aqueous dispersion of resin particles. As a specific example of the hot melt adhesive, "CHEMIPEARL (registered trademark)" series manufactured by Mitsui Chemicals, Inc. etc. can be cited.

[0052] By using the hot melt adhesive, even for the paper packaging sheet 10, through heat sealing, the packaging sheets can be bonded to each other. In heat sealing, the two edge portions of the folded packaging sheet 10 as described above (the two edge portions in the lateral direction D2 of the packaging sheet 10) are inserted into, for example, a pair of rollers, and the packaging sheet 10 can be pressed together in the thickness direction by pressurizing and heating the two rollers. The pair of rollers can be, for example, a combination of a roller having a plurality of convex portions on the surface and a roller having no unevenness on the surface. At this time, the plurality of convex portions of one roller press against the packaging sheet, and a plurality of pressing portions corresponding to the convex portions can be formed on the packaging sheet. In this pressing portion, when there is a hot melt adhesive between the facing packaging sheets, the hot melt adhesive is melted or softened by heat, adheres closely to the packaging sheet, and then the hot melt adhesive cools and solidifies. Thus, in the packaging sheet and the hot melt adhesive, the materials are strongly bonded to each other. Therefore, in the present embodiment using the hot melt adhesive, compared with the conventional sealing that does not use the hot melt adhesive and utilizes physical deformation (such as uneven formation) of the packaging sheet, the sealing portion can be formed more firmly (with high sealing performance).

[0053] Furthermore, the sealing strength obtained by the heat-sealing agent can be improved by allowing the heat-sealing agent to penetrate into the paper packaging sheet. This is because, through heat-sealing means of heating and pressurization, the softened or melted heat-sealing agent enters between the fibers of the paper, and the combination of the paper packaging sheet and the heat-sealing agent is firm. Further, by allowing the softened or melted heat-sealing agent to ooze out to the non-coated surface (back side) opposite to the coated surface of the paper packaging sheet on which the heat-sealing agent is coated, the sealing strength can be further improved. After the heat-sealing agent oozes out to the opposite side of the paper packaging sheet and is in a cooled and solidified state, the solid heat-sealing agent continuously exists from one side to the other side in the thickness direction of the paper packaging sheet, so the combination of the packaging sheet and the heat-sealing agent is more firm. In addition, by allowing the heat-sealing agent to appear on the coated surface where the heat-sealing agent is coated and the non-coated surface on the opposite side, the adhesiveness of the heat-sealing agent is also exhibited on the opposite side of the packaging sheet. Therefore, in the region where, for example, three packaging sheets overlap, the sealing performance of both sides of the region of the packaging sheet disposed in the center (the second region R2 in the region Zb described later) can also be improved.

[0054] Here, a hole-sealing agent is generally provided on a paper sheet. The sheet coated with the hole-sealing agent is called a hole-sealing agent-coated sheet. The hole-sealing agent is coated for the following purpose: to prevent the specified agent (such as ink) from oozing out from the coating side to the opposite side (liquid seepage) during the process of coating the hole-sealing agent and another specified agent on the sheet surface. And in most cases, it is continuously coated on the entire sheet surface. In addition, in this specification, the hole-sealing agent may also include agents coated for the purpose of antifouling, waterproofing (water removal), mold release, etc. Specific examples of the hole-sealing agent include silicone-based resins, paraffin-based resins, olefin-based resins such as polyethylene (PE), polyvinyl alcohol (PVA) resins, fluororesins, and clays. The hole-sealing agent can be coated on the inner surface or the outer surface of the packaging sheet in the form of a solution or a dispersion. Or a film-shaped resin molded body can be pre-formed and attached to the inner surface or the outer surface of the paper packaging sheet.

[0055] When the above-mentioned hole-sealing agent is pre-coated on the paper packaging sheet, the hole-sealing agent will hinder the penetration of the above-mentioned heat-sealing agent into the paper packaging sheet. Therefore, from the viewpoint of promoting the penetration of the heat-sealing agent and improving the sealing strength, it is preferable to suppress the coating amount of the hole-sealing agent. More specifically, the coating weight per unit area of the hole-sealing agent is 10% or less, preferably 5% or less, more preferably 1% or less, and further preferably 0.5% or less with respect to the total unit area weight of the packaging sheet. Here, the total unit area weight of the packaging sheet refers to the unit area weight of the packaging sheet after processing the single-packaged absorbent article as the final product, that is, when coating the hole-sealing agent, it is the unit area weight after coating the hole-sealing agent and before coating the heat-sealing agent. Further, it is preferable that the coating weight per unit area of the above-mentioned hole-sealing agent is 0%, that is, a hole-sealing agent non-coated sheet on which the packaging sheet is not coated with the hole-sealing agent.

[0056] Thus, in the present embodiment, either a non-coated sheet with a hole-sealing agent or a coated sheet with a hole-sealing agent is used as the packaging sheet, and the coating weight of the hole-sealing agent provided on the packaging sheet 10 is also set to be equal to or less than a specified amount. As a result, as described above, the penetration of the hot-melt adhesive into the paper-based packaging sheet during heating and pressing by the heat-sealing means is promoted. Therefore, compared with the case where the same amount of hot-melt adhesive is used but does not penetrate into the packaging sheet 10, the sealing strength of the sealed portion 15 can be improved.

[0057] In addition, regardless of the presence or absence of the hole-sealing agent, in order to promote the penetration of the softened or melted hot-melt adhesive into the paper-based packaging sheet 10 by heating and pressing using the heat-sealing means and improve the sealing strength, a paper-based packaging sheet with a low density can be used. At this time, the density of the packaging sheet 10 is 0.74 g / cm 3 Hereinafter, preferably 0.72 g / cm 3 Hereinafter, more preferably 0.71 g / cm 3 Hereinafter. In the case of the packaging sheet 10 having such a density, the intervals between the fibers of the paper-based packaging sheet 10 are wide, so that the hot-melt adhesive softened or melted by heating and pressing can easily enter between the fibers, and the penetration of the hot-melt adhesive into the packaging sheet is promoted. In addition, in order to ensure the strength of the packaging sheet 10 of the single-pack absorbent article 100, the density of the packaging sheet 10 is preferably 0.30 g / cm 3 or more, more preferably 0.40 g / cm 3 or more, and still more preferably 0.42 g / cm 3 or more.

[0058] Furthermore, when the density of the packaging sheet 10 is 0.42 g / cm 3 or more, preferably 0.55 g / cm 3 or more, and more preferably 0.60 g / cm 3 or more, thereby, in the process of coating the hot-melt adhesive in the initial stage of manufacturing, that is, the process of coating the hot-melt adhesive in the form of an aqueous dispersion of resin particles on the packaging sheet, the hot-melt adhesive can be made difficult to ooze out to the opposite side of the packaging sheet 10 (preventing liquid leakage). When the hot-melt adhesive is coated, if the hot-melt adhesive in the form of an aqueous dispersion of resin particles oozes out, the hot-melt adhesive adheres to the components of the manufacturing apparatus (such as the surface of the conveyor for transportation), and the possibility of causing inconvenience is high. By the above density, such inconvenience can also be prevented.

[0059] Furthermore, hereinafter, with reference to the drawings, the leakage of the hot-melt adhesive will be further described. Figure 5 A schematic diagram of the packaging sheet 10 with the hot-melt adhesive 20 provided on the inner surface is given. Figure 5 It is Figure 1 a cross-sectional view of the packaging sheet 10 along the II-II line, and is a view showing the packaging sheets 10 separated from each other. As Figure 5As shown, the heat-sealing agent 20 is in a state of adhering to the inner surface of the packaging sheet 10 immediately after coating. When heat and pressure are applied during heat-sealing, the coated heat-sealing agent 20, that is, the resin particles of the heat-sealing agent, soften or melt and penetrate into the packaging sheet 10. Specifically, it penetrates between the fibers contained in the paper packaging sheet 10 and can ooze out to the surface (outer surface) opposite to the surface where the heat-sealing agent 20 is coated.

[0060] As Figure 5 shown, when the packaging sheet 10 is triple-folded inside, at the places where the first region R1 and the third region R3 face each other, and at the places where the second region R2 and the third region R3 face each other, the heat-sealing agent 20 coated on the inner surface of the packaging sheet 10 faces each other, so sufficient sealing strength can be obtained. On the other hand, at the place where the first region R1 and the second region R2 face each other, the heat-sealing agent 20 is only coated on one packaging sheet 10, so the sealing strength is slightly weak. Therefore, for example, when the first region R1 is peeled off from one end 11 during opening, the force required to peel open the triple-overlapping region Zb and the double-overlapping region Za1 is different, and a sense of discomfort is generated during opening, or the first region R1 in the triple-overlapping region Zb may be accidentally peeled off before opening. In this regard, in the present embodiment, by making the packaging sheet a non-coated sheet of the sealing agent, or even if the packaging sheet is a coated sheet of the sealing agent, the coating weight of the sealing agent is made to be below a specified value relative to the total unit area weight of the packaging sheet after the heat-sealing agent is provided, or by using a packaging sheet with a specified density, the heat-sealing agent 20 can penetrate into the packaging sheet 10 and then ooze out to the outer surface. In particular, by making the heat-sealing agent 20 ooze out from the inner surface of the second region R2 to the outer surface, at the place where the first region R1 and the second region R2 face each other, the heat-sealing agent 20 can also face each other, and the sealing strength between the packaging sheets is improved. As a result, when the first region R1 is peeled off from one end 11 during opening, the difference in the force required to peel the triple-overlapping region Zb and the double-overlapping region Za1 is small, the sense of discomfort can be suppressed, and in addition, it is also possible to prevent the first region R1 in the triple-overlapping region Zb from being accidentally opened.

[0061] In addition, Figure 6 A schematic diagram of the packaging sheet 10 with the heat-sealing agent 20 provided on the outer surface is given. Figure 6 It is also a cross-sectional view of the packaging sheet 10 along the II-II line of Figure 1 and is a view showing the packaging sheets 10 separated from each other. In addition, when the heat-sealing agent 20 is coated on the outer surface of the packaging sheet 10, it is preferable to fold the packaging sheet 10 after the solvent (water) of the coated aqueous dispersion volatilizes and the heat-sealing agent resin particles are fixed on the packaging sheet 10.

[0062] As Figure 6As shown, when the hot melt adhesive 20 is freshly coated and attached to the outer surface of the packaging sheet 10, when heat and pressure are applied during heat sealing, the resin particles of the coated hot melt adhesive 20, i.e., the hot melt adhesive, soften or melt and penetrate into the packaging sheet 10. Specifically, between the fibers contained in the paper packaging sheet 10, it can ooze out to the surface (inner surface) opposite to the surface where the hot melt adhesive 20 is coated.

[0063] As Figure 6 In the example shown, where the first region R1 and the second region R2 face each other, the hot melt adhesive 20 is provided only on one side, and outside this, there is no hot melt adhesive 20 between the packaging sheets 10. Even in such a case, in the present embodiment, by making the packaging sheet a non-coated sheet for the sealing agent, or even if the packaging sheet is a coated sheet for the sealing agent, the coating weight of the sealing agent is below a specified value relative to the total unit area weight of the packaging sheet after the hot melt adhesive is provided, or by using a packaging sheet with a specified density, the hot melt adhesive 20 penetrates into the packaging sheet 10 and can further ooze out to the inner surface, so that sealing based on heat sealing can be performed along the longitudinal direction D1. Further, at the place where the first region R1 and the second region R2 face each other and at the place where the first region R1 and the third region R3 face each other, the difference in sealing strength can also be reduced. Therefore, when the first region R1 is peeled off from one end 11 during opening, the difference in the force required for peeling in the three-layer overlapping region Zb and the two-layer overlapping region Za1 is small, which can suppress the sense of incongruity and also prevent accidental opening of the first region R1 in the three-layer overlapping region Zb.

[0064] In this way, in the present embodiment where oozing of the hot melt adhesive occurs, the difference between the following two can be reduced, so that the adhesion (for example Figure 5 in the example, the adhesion between the first region R1 and the third region R3, or the adhesion between the second region R2 and the third region R3) obtained by heat sealing with the surfaces (coating surfaces) coated with the hot melt adhesive facing each other, and the adhesion (for example Figure 5 in the example, the adhesion between the first region R1 and the second region R2) obtained by heat sealing with the surface (coating surface) coated with the hot melt adhesive and the surface (non-coated surface) not coated with the hot melt adhesive facing each other. Here, the difference between Saa and San when Saa is 100%, i.e., (Saa - San) / Saa × 100, is preferably 20% or less, more preferably 10% or less, further preferably 5% or less, and further preferably 3% or less.

[0065] In addition, the region on the packaging sheet 10 where the hot melt adhesive is provided is not particularly limited, and can be the region contained in at least the sealing portion 15 in the single-pack absorbent article 100. The hot melt adhesive can be provided on either the inner surface or the outer surface of the packaging sheet 10. Figure 2 is given, an example where the hot melt adhesive 20 is provided on the inner surface of the packaging sheet 10. As Figure 2In the example shown, the heat-sealing agent 20 is provided in a strip shape on the two edge portions 18, 18 in the transverse direction D2 of the packaging sheet 10 included in the predetermined regions 14, 14 formed in the above-mentioned sealing portion. Here, the heat-sealing agent 20 can be provided in the predetermined regions (the outlines of the sealing portion formation predetermined regions are marked with dotted lines in Figure 2 the regions other than the sealing portions 15, 15 of the packaging sheet 10. Thus, the heat-sealing agent 20 is coated in a minimum amount on the region where heat-sealing is performed by pressing, so that the usage amount of the heat-sealing agent 20 can be saved.

[0066] As the coating means of the heat-sealing agent 20, for example, coating based on the following methods can be mentioned: flexographic printing, offset printing, screen printing, gravure printing, spray gun, dispenser, roll coating. Among them, since a stable coating amount and coating pattern can be obtained, and inexpensive water-based inks and the like can be used, flexographic printing is preferably used. The heat-sealing agent can be coated over the entire surface or in a specified pattern, such as a dot pattern.

[0067]

Example

[0068] [Experimental Example 1]

[0069] Prepare paper packaging sheets of Preparation Examples 1-1 to 1-7 (length in the MD direction 100 mm × length in the CD direction 100 mm, without coating of the sealing agent), and measure the basis weight per unit area, thickness, etc. Further, a heat-sealing agent is coated on the paper packaging sheet, and the bleeding of the heat-sealing agent during coating and the sealing performance during sealing are evaluated. The packaging sheets used are as follows.

[0070] Example 1-1: Unryu paper (manufactured by Marubishi PaperTech Co., Ltd.), marked basis weight per unit area 14 g / m 2

[0071] Example 1-2: Unryu paper (manufactured by Marubishi PaperTech Co., Ltd.), marked basis weight per unit area 17 g / m 2

[0072] Example 1-3: Unryu paper (manufactured by Marubishi PaperTech Co., Ltd.), marked basis weight per unit area 30 g / m 2

[0073] Example 1-4: FS rayon paper PM (manufactured by Marubishi PaperTech Co., Ltd.), marked basis weight per unit area 17 g / m 2 Example 1-5: FS rayon paper PM (manufactured by Marubishi PaperTech Co., Ltd.), marked basis weight per unit area 30 g / m 2 Example 1-6: Gold paper (manufactured by Daio Paper Corporation), marked basis weight per unit area 24.4 g / m 2

[0074] Examples 1 - 7: Gold Paper (manufactured by Oji Paper Co., Ltd.), indicating a basis weight of 35 g / m 2

[0075] = Evaluation of seepage during coating =

[0076] On the entire surface of one side of the paper packaging sheet in each example, a heat - sealing agent ("CHEMIPEARL (registered trademark) S500" manufactured by Mitsui Chemicals, Inc.) was uniformly coated at a basis weight of 1.8 g / m 2 using a flexographic printing press. The winding condition of the packaging sheet on the central roller of the flexographic printing press during coating was visually observed to evaluate the seepage of the heat - sealing agent during coating. The evaluation criteria are as follows.

[0077] 〇: No seepage was confirmed (winding operation may not be required).

[0078] △: Slight seepage was confirmed (slight winding, poor workability).

[0079] ×: Obvious seepage was confirmed (winding, impossible to operate).

[0080] = Evaluation of infiltration after heat - sealing =

[0081] As described above, the paper packaging sheet coated with the heat - sealing agent was folded into an inner three - fold as shown in the long - side direction on the side where the heat - sealing agent was coated, and the edge portion in the short - side direction corresponding to the part where the heat - sealing agent was coated was inserted between a pair of rollers to perform heat - sealing, forming a sealing portion with a width of 6 mm. Among the pair of rollers, one roller has convex portions for forming a pressing portion on its surface, and the other is a flat roller with no unevenness on its surface. The pair of rollers is arranged such that their axial directions are along the long - side direction of the packaging sheet. In addition, the roller pressure was set to 3.0 MPa, the roller temperature was 105 °C, and the heat - sealing speed was 1.2 m / second. Then, the formed sealing portion was visually observed as a whole along the long - side direction of the packaging sheet to evaluate the sealing performance. The evaluation criteria are as follows. Figure 1

[0082] 〇: Sealed as a whole along the longitudinal direction.

[0083] ×: An unsealed position was confirmed.

[0084] The measured values and evaluation results are shown in Table 1.

[0085]

Table 1

[0086]

[0087] As shown in Table 1, it can be seen that it has a specified density (0.74 g / cm 3In the packaging sheets (Examples 1-1, 1-2, 1-4, and 1-6) below, high sealing performance can be obtained. Further, it is also known that the packaging sheets (Examples 1-2, 1-4, 1-6, and 1-7) having a specified density (0.42 g / cm 3 or more) can prevent seepage during hot melt adhesive coating.

[0088] [Experimental Example 2]

[0089] On the entire single surface of a paper packaging sheet (FS rayon paper PM, 95 mm in length in the MD direction × 35 mm in length in the CD direction, without sealant coating), a hot melt adhesive (Mitsui Chemicals, Inc.'s "CHEMIPEARL (registered trademark) S500") was coated at 2.7 g / m 2 per square meter by flexographic printing. Two of the above-mentioned packaging sheets were overlapped with the hot melt adhesive-coated surfaces facing each other as Example 2-1. In addition, two of the above-mentioned packaging sheets were overlapped with the coated surface and the non-coated surface facing each other as Example 2-2. The samples of each example were sandwiched between a metal plate having convex portions for forming a press-fitting portion on the surface and a flat metal plate having no unevenness on the surface, and heat-sealed under pressure using a pneumatic press. The heat-sealing conditions were set gas pressure of 0.8 MPa, pressing temperature of 115 °C, and heat-sealing time of 100 seconds. The sealing strength of each example was measured and evaluated.

[0090] = Evaluation of Sealing Strength =

[0091] The end of the sealed portion of the sample of each example was peeled off by 10 mm, one side of the packaging sheet was turned over, and the ends of the two packaging sheets were respectively attached to the clamps of a tensile testing machine (manufactured by ORIENTEC Co., Ltd., TENSILON testing machine "RTC1210") and pulled in opposite directions to measure the load (N). The measurement was carried out at a clamp interval of 10 mm and a tensile speed of 100 mm / minute. The maximum load during the measurement was taken as the sealing strength (peel strength) (N) of each example. In addition, in order to evaluate the difference in the sealing strength between Example 2-1 (adhesion between coated surfaces) and Example 2-2 (adhesion between coated surface and non-coated surface), the ratio of the difference in sealing strength was calculated by the following formula:

[0092] Ratio of difference in sealing strength (%)

[0093] = {(Sealing strength of Example 2-1) - (Sealing strength of Example 2-2)} / (Sealing strength of Example 2-1) × 100 The results are shown in Table 2.

[0094]

Table 2

[0095]

[0096] *1: Ratio of difference in sealing strength (%)

[0097] ={(Sealing strength of Example 2-1)-(Sealing strength of Example 2-2)} /

[0098] (Sealing strength of Example 2-1)×100

[0099] As can be seen from Table 2, the difference between the strength of the adhesion between the coated surfaces (Example 2-1) and the strength of the adhesion between the coated surface and the non-coated surface (Example 2-2) is very small. This is considered to be because the heat-sealing agent is coated only on one side, and the heat-sealing agent also sufficiently oozes out to the surface on the opposite side of the coated surface of the packaging sheet through heating and pressing during heat sealing.

[0100] As described above, the present invention has been described based on the embodiments, but the present invention is not limited by these embodiments. The above embodiments can be variously changed, modified, replaced, added, deleted, combined, etc. within the scope recited in the patent claims, and these also belong to the technical scope of the present invention. In addition, the above structural elements can be arbitrarily combined.

[0101] Furthermore, the preferred embodiments of the present invention are described below.

[0102] The first embodiment is a separately packaged absorbent article in which the absorbent article is packaged with a paper packaging sheet. The packaging sheet is folded inward on the inner surface side in the longitudinal direction of the packaging sheet, and both edge portions in the transverse direction perpendicular to the longitudinal direction are sealed to form a sealed portion. A heat-sealing agent is provided in at least the region of at least one of the inner surface and the outer surface of the packaging sheet that contains the sealed portion. The packaging sheet is a non-coated sheet or a coated sheet of a hole-sealing agent, and the coating weight of the hole-sealing agent is 10% or less with respect to the total unit area weight of the packaging sheet after the heat-sealing agent is provided.

[0103] According to the above first embodiment, a heat-sealing agent is provided in at least the region of at least one of the inner surface and the outer surface of the packaging sheet that contains the sealed portion. Therefore, even for a paper packaging sheet, in order to form the sealed portion at both edge portions, a means such as heat sealing can be adopted, and thus, compared with the conventional sealing that does not use heat sealing, such as pressing the packaging sheet between meshing tooth rows, the sealing can be performed more firmly (high sealing property).

[0104] In addition, a hole-sealing agent is generally applied to a paper sheet. That is, a hole-sealing agent-coated sheet is often used. The hole-sealing agent is applied in advance, for example, in the process of applying a specified agent (such as ink, a functional agent other than ink, etc.) to the surface of the sheet to prevent the specified agent from seeping out (bleeding) to the opposite side of the side where the agent is applied. However, when forming a sealed portion of a single-packaged absorbent article by heat sealing, the above-mentioned heat-sealing agent can penetrate into the paper packaging sheet in such a way that it further oozes out to the opposite side of the packaging sheet, and thus the sealing can be more firmly performed. In this method, as the packaging sheet, a non-hole-sealing-agent-coated sheet is used, or even if it is a hole-sealing-agent-coated sheet, the coating weight of the hole-sealing agent is suppressed. More specifically, the coating weight of the hole-sealing agent is 10% or less relative to the total unit area weight of the packaging sheet after the heat-sealing agent is applied. Thereby, the heat-sealing agent that softens or melts during heating and pressing by the heat-sealing means easily penetrates between the fibers of the paper packaging sheet, and the combination of the packaging sheet and the heat-sealing agent is stronger. Further, when the softened or melted heat-sealing agent oozes out to the opposite side of the side where the heat-sealing is applied on the packaging sheet, the heat-sealing agent can continuously exist from one side to the other side in the thickness direction of the packaging sheet, so the combination of the packaging sheet and the heat-sealing agent is stronger. In addition, the heat-sealing agent can also appear on the opposite side of the packaging sheet, so the sealing strength on the opposite side can be improved. Therefore, according to this method, even if the amount of the heat-sealing agent is small, a sealed portion with high sealing strength can be formed on the two edge portions of the single-packaged absorbent article.

[0105] In the second method, the packaging sheet is a non-hole-sealing-agent-coated packaging sheet.

[0106] According to the above second method, the heat-sealing agent easily penetrates further between the fibers of the paper packaging sheet during heating and pressing. Therefore, the above-mentioned effect of increasing the sealing strength of the sealed portion can be enhanced.

[0107] In the third method, the density of the packaging sheet is 0.30 - 0.74 g / cm 3 。

[0108] According to the above third method, the packaging sheet has a specified small range of density. Thus, while ensuring the strength of the packaging sheet of the single-packaged absorbent article, the heat-sealing agent easily penetrates further between the fibers of the packaging sheet during heating and pressing, so more firm sealing can be performed, and the sealing strength of the sealed portion can also be further improved.

[0109] In the fourth method, the unit area weight of the packaging sheet is 15 - 30 g / m 2 。

[0110] According to the above fourth method, by making the basis weight (grammage) of the packaging sheet within a specified range, while ensuring the strength of the packaging sheet, the roughness when holding a single-packaged absorbent article can be reduced.

[0111] In the fifth method, the hot melt adhesive is provided on the inner surface of the packaging sheet.

[0112] In the state where the packaging sheet is folded, the area where the inner surfaces of the packaging sheet face each other is large. According to the above fifth method, since the hot melt adhesive is provided on the inner surface of the packaging sheet, the adhesion between the packaging sheets based on the hot melt adhesive is more solid. In addition, according to this method, in the stage before heat sealing (before hot melt bonding), the hot melt adhesive does not exist or exists only in a small amount on the outer surface, so the possibility of the hot melt adhesive adhering to components of the manufacturing apparatus etc. can be reduced.

[0113] In the sixth method, the sealing strength of the portion where the coating surfaces of the packaging sheet coated with the hot melt adhesive face each other and are sealed is Saa, and the sealing strength of the portion where the coating surface of the packaging sheet coated with the hot melt adhesive and the non-coated surface not coated with the hot melt adhesive face each other and are sealed is San,

[0114] (Saa - San) / Saa × 100 ≤ 20 (%).

[0115] According to the above sixth method, the difference in the sealing strength brought about by the adhesion between the coating surfaces of the hot melt adhesive-coated surfaces is small. Therefore, even when the hot melt adhesive is coated on the inner surface of the packaging sheet, when the packaging sheet is triple-folded, the force required for peeling according to the position can be made substantially uniform. Therefore, when opening, the entire packaging sheet can be peeled off without a sense of incongruity.

[0116] The seventh method is a single-packaged absorbent article in which the absorbent article is packaged with a paper packaging sheet. The packaging sheet is folded inward on the inner surface side in the longitudinal direction of the packaging sheet, and both edge portions in the lateral direction perpendicular to the longitudinal direction are sealed to form a sealed portion. The hot melt adhesive is provided in at least the area included in the sealed portion of one of the inner surface and the outer surface of the packaging sheet. The density of the packaging sheet is 0.30 to 0.74 g / cm 3 .

[0117] According to the above seventh method, the hot melt adhesive is provided in at least the area included in the sealed portion of one of the inner surface and the outer surface of the packaging sheet. Therefore, even for a paper packaging sheet, in order to form the sealed portion at both edge portions, heat sealing can be adopted, and thus compared with not adopting heat sealing, such as sealing based on physical unevenness formation etc., sealing can be performed more solidly (high sealing property).

[0118] In addition, when forming the sealed portion of the individually packaged absorbent article by heat sealing, a method in which the above heat-sealing agent penetrates into the paper packaging sheet and further oozes out to the opposite side of the packaging sheet can achieve a more solid seal. In this method, by setting the density of the paper packaging sheet within a specified range, when heating and pressing based on the heat-sealing means, the heat-sealing agent easily penetrates between the fibers of the paper packaging sheet, and the combination of the packaging sheet and the heat-sealing agent becomes stronger. Further, when the heat-sealing agent oozes out to the side opposite to the side of the packaging sheet where the heat-sealing is applied, the heat-sealing agent can continuously exist from one side to the other side in the thickness direction of the packaging sheet, so the combination of the packaging sheet and the heat-sealing agent is stronger. In addition, the heat-sealing agent can also appear on the opposite side of the packaging sheet, so the sealing strength on this opposite side can be improved. Therefore, according to this method, even if the amount of the heat-sealing agent is small, sealed portions with higher sealing strength can be formed at both edge portions of the individually packaged absorbent article.

[0119] This application claims priority based on Japanese Patent Application No. 2023-055943 filed on March 30, 2023, and the entire content thereof is incorporated herein by reference.

[0120]

Reference Signs

[0121] 1 Absorbent article

[0122] 3 Top sheet

[0123] 4 Absorbent body

[0124] 7 Side sheet

[0125] 10 Packaging sheet

[0126] 11 One longitudinal end

[0127] 12 The other longitudinal end

[0128] 14 Predetermined region for forming sealed portion

[0129] 15 Sealed portion

[0130] 18 Edge portion region

[0131] 20 Heat-sealing agent

[0132] 30 Fixing band

[0133] 100 Individually packaged absorbent article

[0134] D1 Longitudinal direction (long side direction) of the packaging sheet

[0135] D2 Transverse direction (short side direction) of the packaging sheet

[0136] F1 First fold line

[0137] F2 Second broken line

[0138] R1 First region

[0139] R2 Second region

[0140] R3 Third region

[0141] Za, Za1, Za2 Two overlapping regions

[0142] Zb Three overlapping regions

Claims

1. A separately packaged absorbent article, wherein, The absorbent article is packaged with a paper packaging sheet. The packaging sheet is folded inward on the inner surface side in the longitudinal direction of the packaging sheet, and two edge portions in the transverse direction perpendicular to the longitudinal direction are sealed to form a sealed portion. A hot melt adhesive is provided in at least the area of the sealed portion of one of the inner surface and the outer surface of the packaging sheet. The packaging sheet is a non-coated sheet for a hole-sealing agent or a coated sheet for a hole-sealing agent, and the coating weight of the hole-sealing agent is 10% or less with respect to the total unit area weight of the packaging sheet after the hot melt adhesive is provided.

2. The individually packaged absorbent article according to claim 1, wherein the packaging sheet is a non-coated packaging sheet for a hole-sealing agent.

3. The individually wrapped absorbent article according to claim 1 or 2, wherein the density of the packaging sheet is 0.30 to 0.74 g / cm 3 .

4. The individually wrapped absorbent article according to claim 1 or 2, wherein the basis weight of the packaging sheet is 15 to 30 g / m 2 .

5. The individually packaged absorbent article according to claim 1 or 2, wherein the hot melt adhesive is provided on the inner surface of the packaging sheet.

6. For the individually packaged absorbent article according to claim 1 or 2, the sealing strength of the portion where the coated surfaces of the packaging sheet coated with the hot melt adhesive face each other for sealing is Saa, and the sealing strength of the portion where the coated surface of the packaging sheet coated with the hot melt adhesive and the non-coated surface not coated with the hot melt adhesive face each other for sealing is San. (Saa - San) / Saa×100≤20(%).

7. A separately packaged absorbent article, wherein, The absorbent article is packaged with a paper packaging sheet. The packaging sheet is folded inward on the inner surface side in the longitudinal direction of the packaging sheet, and two edge portions in the transverse direction perpendicular to the longitudinal direction are sealed to form a sealed portion. A hot melt adhesive is provided on at least the area of the sealed portion of one of the inner surface and the outer surface of the packaging sheet. The density of the packaging sheet is 0.30 to 0.74 g / cm 3 .

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