JP7516320B2 - Absorbent articles - Google Patents

Description

The present invention relates to absorbent articles such as sanitary napkins, panty liners, and incontinence pads, and more specifically to absorbent articles in which three-dimensional gathers that stand up against the skin due to the contractile force of a thread-like elastic stretch member are formed on both sides of the skin-contacting surface.

Conventionally, as shown in Figs. 9 and 10, an absorbent article N has been known in which an absorbent body 52 made of cotton-like pulp or the like is interposed between a liquid-impermeable back sheet 50 made of a polyethylene sheet or a polyethylene-laminated nonwoven fabric, a liquid-permeable top sheet 51 made of a nonwoven fabric or a porous plastic sheet, and side sheets 53, 53 made of nonwoven fabric are arranged on both sides of the skin-contacting surface side, and a folded portion is formed by folding back the inner side portion 53a of the side sheet 53 in the width direction, and one or more thread-like elastic and stretchable members 54 are arranged in a stretched state along the longitudinal direction between the side sheets 53, 53 of the folded portion, thereby forming three-dimensional gathers 55, 55 that stand up against the skin side by the contraction force of the thread-like elastic and stretchable members 54 over a predetermined longitudinal section.

The side sheet 53 forms three-dimensional gathers 55 that stand up against the skin side by the contraction force of the thread-like elastic and stretchable member 54 over a predetermined longitudinal section (three-dimensional gather forming section) including at least the section corresponding to the wearer's body fluid discharge site H, and the tips of the three-dimensional gathers 55 are brought into close contact with the body to block body fluids and prevent side leakage. In the section (fixed section) on the front and rear ends side from this, the thread-like elastic and stretchable member 54 is not joined to the side sheet 53, and the side sheet 53 is folded and laminated and joined to the absorbent body 52 side so that the contraction force of the thread-like elastic and stretchable member 54 does not act on the side sheet 53.

This type of absorbent article has also been improved in many ways. For example, the following Patent Document 1 discloses an absorbent article having a composite stretchable section that can stretch in one direction to form a pleated structure with high alignment and excellent appearance, the composite stretchable section having two sheets and a plurality of elastic members arranged between the two sheets, the plurality of elastic members extending along the one direction and arranged at intervals in a direction perpendicular to the one direction, at least one of the two sheets having a plurality of high-density sections that are not directly joined to each other, the high-density sections overlap at least one of the plurality of elastic members and are formed intermittently in the extension direction of the one elastic member, and the composite stretchable section in a contracted state has a pleated structure formed in which one of the sheets has a plurality of concave ribs with the high-density section at its bottom and a convex rib located between the concave ribs.

By adopting such a structure, the appearance of the three-dimensional gathers is excellent in the three-dimensional gather forming section where the side sheet is formed with a pleated structure by the contraction force of the thread-like elastic stretch member. However, in the fixed section on the front and rear ends side, that is, the section where the thread-like elastic stretch member is not joined to the side sheet and the side sheet is folded and fixed to the absorbent body side, as shown in Figure 9, the end of the thread-like elastic stretch member contracts forcefully when the thread-like elastic stretch member is cut, causing it to become tangled or twisted between the side sheets, resulting in a poor appearance. This phenomenon tends to occur more easily on the rear side where the fixed section is longer than the front side. In particular, when a thread-like elastic stretch member of a color other than white (e.g., light blue) is used, the tangled or twisted state is clearly visible from the outside, which may give the user the impression that the absorbent article is of poor quality.

As an example of preventing tangling or twisting of the ends due to the cutting of the thread-like elastic stretch member, the following Patent Document 2 discloses an absorbent article in which the leakproof section is composed of an elastic body arranged along the longitudinal direction of the absorbent article and a sheet arranged along the longitudinal direction, wrapping the elastic body, and at least a portion of which is fixed to the top sheet, the leakproof section has a central region in the longitudinal direction and a pair of end regions located outside the central region in the longitudinal direction, the elastic body has a fixed portion at least at the boundary between the central region and the end regions, where the elastic body is fixed to the sheet in a state in which it is stretched in the longitudinal direction, and a free end located outside the fixed portion in the longitudinal direction and not fixed to the sheet, the end region has a joining process where a joining process is performed to join the portions of the sheets facing each other, and a non-joining process where the joining process is not performed, and the free end is disposed in the non-joining process.

JP 2020-195504 A JP 2010-264161 A

As shown in paragraph [0073] and FIG. 8(C) of the specification of Patent Document 2, the joint processing portion (53A) may be provided everywhere except the portion where the elastic body (51) and the sheet (52) contact each other. It is believed that by adopting this configuration, it is possible to prevent the ends of the elastic body from becoming entangled or twisted.

However, in the absorbent article described in Patent Document 2, the joint processing portion is formed by embossing. When the joint processing portion is provided everywhere except where the elastic body and the sheet contact, the joint processing portion, which has been compressed by the embossing, comes into direct contact with the wearer's skin, resulting in a problem of poor feel against the skin.

Therefore, the main objective of the present invention is to provide an absorbent article that improves the alignment of the ends of the thread-like elastic stretchable member and has a pleasant feel against the skin.

In a first aspect for solving the above problems, the present invention comprises side sheets arranged along the longitudinal direction on both sides of the skin contact surface side, with a double sheet portion formed on the inner side in the width direction, and a thread-like elastic and stretchable member arranged along the longitudinal direction between the double sheet portions, and three-dimensional gathers are formed in which the inner side portions of the side sheets rise towards the skin in a predetermined longitudinal section including the wearer's body fluid discharge section by the contractile force of the thread-like elastic and stretchable member,
The absorbent article is characterized in that, at least behind the section in which the three-dimensional gathers are formed, a plurality of convex portions are arranged along the longitudinal direction, by which the double sheet portion is integrally bulged toward the skin, and an alignment joint is provided in which an adhesive portion is arranged to bond the side sheets of the double sheet portion together so as to fill the gaps between the convex portions, and the thread-like elastic stretch member is arranged along the longitudinal direction in a portion other than the alignment joint, without being joined to the side sheet.

In the first aspect, at least behind the three-dimensional gather forming section where three-dimensional gathers standing on the skin side are formed, a plurality of convex portions are arranged along the longitudinal direction by integrally protruding the double sheet portion toward the skin side, and an alignment joint is provided in which an adhesive portion is arranged to bond the side sheets of the double sheet portion together so as to fill the gaps between the convex portions, and the thread-like elastic, stretchable member is provided along the longitudinal direction at a location other than the alignment joint without being joined to the side sheet. As a result, even if the end of the thread-like elastic, stretchable member contracts forcefully when the thread-like elastic, stretchable member is cut, the alignment joint suppresses swell in the width direction, improving the alignment of the end of the thread-like elastic, stretchable member.

In addition, at the alignment joint, the tip of the protrusion that causes the side sheet to bulge toward the skin comes into contact with the wearer's skin, providing a pleasant feel against the skin.

In a second aspect, the absorbent article according to claim 1 is provided, in which the convex portion has a contour line consisting of a closing curve.

In the second aspect, the convex portion has a contour line consisting of a closing curve, so that even if the side sheet is stretched during the manufacturing process of the absorbent article or when the absorbent article is worn, the shape of the convex portion bulging toward the skin is more likely to be maintained, and a comfortable fit can be obtained more reliably.

As a third aspect, the absorbent article according to claims 1 and 2 is provided, in which the adhesive portions are disposed in respective widthwise recesses between adjacent longitudinally adjacent protrusions.

In the third aspect, the arrangement of the adhesive parts is specifically defined, and the adhesive parts are arranged in the widthwise recesses between adjacent convex parts in the longitudinal direction. By arranging the adhesive parts in this way, the spaces between the convex parts into which the thread-like elastic stretch member enters are filled, preventing the thread-like elastic stretch member from undulating or twisting, and further improving the alignment of the ends of the thread-like elastic stretch member.

As a fourth aspect, the absorbent article according to any one of claims 1 to 3 is provided, in which a plurality of the thread-like elastic stretch members are arranged, and a plurality of the alignment joints are arranged side by side with intervals in the width direction.

In the fourth aspect, when multiple thread-like elastic stretch members are arranged, multiple alignment joints are arranged in parallel at intervals in the width direction to accommodate the multiple thread-like elastic stretch members.

In a fifth aspect, the absorbent article according to claim 4 is provided, in which the alignment joints arranged in parallel in the width direction are arranged at the same position in the width direction, or adjacent alignment joints are arranged at different positions in the width direction.

In the fifth aspect, when the alignment joints are arranged in a row with a space between them in the width direction, the overall pattern for arranging the alignment joints arranged in a row in the width direction is specified.

As a sixth aspect, the absorbent article according to any one of claims 1 to 5 is provided, in which the thread-like elastic stretchable member has a color other than white.

The sixth aspect above is intended for cases where a color other than white is used as the thread-like elastic stretch member, in which case tangling or twisting of the ends of the thread-like elastic stretch member becomes more noticeable.

As explained above in detail, the present invention makes it possible to provide an absorbent article that prevents the ends of the thread-like elastic stretchable member from becoming tangled or twisted, and that has a pleasant feel against the skin.

1 is a partially cutaway development view of a sanitary napkin 1 according to the present invention. FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 2 is a cross-sectional view taken along line III-III in FIG. FIG. 2 is an enlarged plan view of a portion where an alignment joint 10 is provided. 5 is a view taken along the line V-V in FIG. 4. 13 is a plan view showing a modified example of the protrusion 11. FIG. 13 is an enlarged plan view of a portion where an alignment joint 10 according to a modified example is provided. FIG. FIG. 4 is a development view of a sanitary napkin 1 according to another embodiment. FIG. 1 is a development view showing a conventional absorbent article N. 10 is a cross-sectional view taken along line XX in FIG. 9.

The following describes in detail the embodiments of the present invention with reference to the drawings.

[Basic structure of sanitary napkin 1]
As shown in Figures 1 to 3, the sanitary napkin 1 according to the present invention comprises a liquid-impermeable back sheet 2 made of a polyethylene sheet or the like, a liquid-permeable top sheet 3 which allows menstrual blood, vaginal discharge and the like (hereinafter collectively referred to as body fluids) to quickly permeate therethrough, an absorbent body 4 made of cotton-like pulp or synthetic pulp sandwiched between the two sheets 2, 3, and side sheets 7 provided on both sides of the skin contacting surface over almost the entire length in the longitudinal direction, and around the periphery of the absorbent body 4, the outer edges of the back sheet 2 and the top sheet 3 are joined at the front and rear end edges by a joining means such as hot melt adhesive, heat sealing, ultrasonic sealing or the like, and the back sheet 2 and the side sheets 7 which extend laterally beyond the absorbent body 4 at both side edges are joined by a joining means such as hot melt adhesive, heat sealing, ultrasonic sealing or the like, thereby forming flap portions without an absorbent body interposed therebetween. In the illustrated example, the absorbent body 4 is surrounded by an envelope sheet 5 made of crepe paper, nonwoven fabric, or the like in order to maintain the shape of the absorbent body 4 and improve diffusion, but this envelope sheet 5 does not have to be provided. In addition, although not illustrated, a second sheet made of hydrophilic nonwoven fabric or the like having approximately the same shape as the topsheet 3 may be disposed adjacent to the non-skin side of the topsheet 3.

The structure of the sanitary napkin 1 will be described in further detail below.
The back sheet 2 is made of a sheet material such as polyethylene that is at least water-proof, but it is preferable to use a material that is moisture-permeable in order to prevent stuffiness. As the water-proof and moisture-permeable sheet material, a microporous sheet obtained by melt-kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching it in a uniaxial or biaxial direction is preferably used. On the non-skin side (outer surface) of the back sheet 2 of the main body portion where the absorbent body 4 is interposed, one or more adhesive layers (not shown) are formed along the napkin longitudinal direction, so that the sanitary napkin 1 is fixed to the shorts when worn on the body. The back sheet 2 may be made of a polylaminated nonwoven fabric obtained by laminating a plastic film and a nonwoven fabric.

Next, the surface sheet 3 is preferably made of a nonwoven fabric with or without holes, a porous plastic sheet, or the like. The material fibers constituting the nonwoven fabric can be synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters, polyamides, regenerated fibers such as rayon or cupra, and natural fibers such as cotton. Nonwoven fabrics obtained by appropriate processing methods such as spunlace, spunbond, thermal bond, meltblown, and needle punch can be used. Of these processing methods, the spunlace method is excellent in terms of flexibility and drapeability, and the thermal bond method is excellent in terms of bulk and high compression recovery. When a large number of through holes are formed in the surface sheet 3, bodily fluids are quickly absorbed, and the surface sheet 3 has excellent dry touch. The fibers of the nonwoven fabric can be either long or short fibers, but it is preferable to use short fibers to give the fabric a towel-like texture. In addition, in order to facilitate embossing, it is preferable to use olefin fibers such as polyethylene or polypropylene with a relatively low melting point. In addition, composite fibers such as core-sheath fibers, side-by-side fibers, and split fibers, which have a core made of fibers with a high melting point and a sheath made of fibers with a low melting point, can also be used.

The absorbent 4 interposed between the back sheet 2 and the top sheet 3 is composed of, for example, cotton-like pulp and a water-absorbent polymer. The water-absorbent polymer is mixed, for example, as granular powder, into the pulp that constitutes the absorbent. Examples of the pulp include chemical pulp obtained from wood, cellulose fibers such as dissolving pulp, and artificial cellulose fibers such as rayon and acetate. In terms of function and cost, softwood pulp, which has longer fibers, is more suitable for use than hardwood pulp.

Synthetic fibers may also be mixed into the absorbent 4. The synthetic fibers may be, for example, polyolefins such as polyethylene or polypropylene, polyesters such as polyethylene terephthalate or polybutylene terephthalate, polyamides such as nylon, or copolymers of these. They may also be a mixture of two of these. Composite fibers such as core-sheath fibers with a high melting point fiber as the core and a low melting point fiber as the sheath, side-by-side fibers, and split fibers may also be used. In the case of hydrophobic fibers, it is desirable to use synthetic fibers that have been surface-treated with a hydrophilizing agent so that they have affinity for body fluids.

In the illustrated example, the width of the top sheet 3 is slightly longer than the width of the absorbent body 4 as shown in the cross-sectional views of Figures 2 and 3, and only covers the absorbent body 4, and on the outer side of the top sheet 3 is a side sheet 7 that is separate from the top sheet 3, specifically, a side sheet 7 made of a nonwoven fabric material that has been appropriately treated to be water-repellent or hydrophilic depending on the purpose of preventing the penetration of menstrual blood or vaginal discharge, or improving the feel on the skin. As the side sheet 7, a material made of natural fibers, synthetic fibers, or regenerated fibers and formed by an appropriate processing method can be used, but it is preferable to use a nonwoven fabric that has a low basis weight and is breathable in order to eliminate the stiff feeling and prevent stuffiness. Specifically, it is preferable to use a nonwoven fabric made with a basis weight of 13 to 23 g/ ^m2 , and a water-repellent nonwoven fabric coated with a silicone-based, paraffin-based, or alkylchromic chloride-based water repellent agent is preferably used to reliably prevent the penetration of body fluids.

As shown in Figures 2 and 3, the side sheets 7 are bonded from the middle part in the width direction to the outer edge of the back sheet 2 with an adhesive such as hot melt, and the laminated sheet parts of the side sheets 7 and the back sheet 2 form side flap parts on both sides of the absorbent body 4 without the absorbent body 4 being interposed.

The side flap portion forms a pair of left and right wing-shaped flap portions W, W which extend from the side edges of the absorbent body 4 in a larger amount than the areas in front and behind the wing-shaped flap portions W, W at a side position approximately corresponding to the wearer's bodily fluid excretion area H, and a pair of left and right hip-hold flap portions WB, WB which extend from the side edges of the absorbent body 4 in a larger amount than the areas in front and behind the wing-shaped flap portions _W , W and the hip-hold flap portions _WB , _WB are each provided with an adhesive layer (not shown) on the outer surface (outer surface side of the back sheet ₂ ) of the wing-shaped flap portions W, W, and the hip-hold flap portions WB, WB, are each folded back to the opposite side (back sheet 2 side) at the folding line RL (see FIG. 1) of the base end when worn with shorts, and are wrapped around the crotch portion of the shorts and fastened, and the hip-hold flap portions WB _{, WB} are fastened to the inner surface of the shorts, covering the buttocks of the wearer when worn.

Meanwhile, the inner side portion 7a of the side sheet 7 is folded back in the width direction to form a double sheet portion, and one or more thread-like elastic stretch members 9, 9... (three in the illustrated example) are arranged along the longitudinal direction between the double sheet portions. The thread-like elastic stretch members 9, 9... are in a stretched state in the longitudinal intermediate portion including the wearer's bodily fluid discharge portion H, and both ends of the section or appropriate positions in the longitudinal direction are joined to the side sheets 7, 7, and the ends (rear and front) of this section in the longitudinal direction form free ends that are not joined to the side sheets 7, 7. In the longitudinal intermediate section including the wearer's bodily fluid discharge portion H, where the thread-like elastic, stretchable members 9, 9... are joined to the side sheets 7, 7, the double sheet portion of the side sheet 7 is arranged in a state in which they are not joined to each other and can protrude toward the wearer's skin side, as shown in Fig. 2, and in the longitudinal end section from this section where the thread-like elastic, stretchable members 9, 9... are not joined to the side sheets, they are adhered to the absorbent body 4 in a laminated state folded back once to the outside, as shown in Fig. 3. As a result, the longitudinal intermediate section including the wearer's bodily fluid discharge portion H, where the thread-like elastic, stretchable members 9, 9... are joined to the side sheets 7, 7, is a three-dimensional gather forming section in which a pair of three-dimensional gathers BS, BS are formed on the left and right sides of the side sheet 7 standing up against the skin side due to the contractile force of the thread-like elastic, stretchable members 9, 9..., and the longitudinal end section from this three-dimensional gather forming section is a fixed section in which the side sheet 7 is fixed to the absorbent body 4 side. The "inner portion 7a" of the side sheet 7 refers to the portion on the inner side of the side sheet 7 in the width direction, and as described above, is the portion that includes the double sheet portion for forming the three-dimensional gathers BS.

As shown in FIG. 1, a compressed groove 6 is formed in a predetermined shape on the skin contact side of the top sheet 3. The compressed groove 6 is a recessed groove formed by compressing the skin contact side of the top sheet 3, causing the top sheet 3 and the absorbent body 4 to be recessed integrally toward the back sheet 2. The compressed grooves 6 are provided in pairs on the left and right along the longitudinal direction on both sides of at least the region corresponding to the wearer's bodily fluid excretion area H.

[Alignment joint]
In this sanitary napkin 1, as shown in Figures 4 and 5, in the fixed section at least rearward of the three-dimensional gather formation section, a plurality of convex portions 11, which are formed by integrally bulging the double sheet portion of the side sheet 7 toward the skin, are arranged along the longitudinal direction, and a plurality of alignment joints 10, each of which is formed by arranging adhesive portions 12 that bond the side sheets 7, 7 of the double sheet portion together so as to fill the gaps between the convex portions 11, 11, are arranged in a row at intervals in the width direction, and the thread-like elastic and stretchable members 9, 9... are provided along the longitudinal direction in areas other than the alignment joints 10, without being joined to the side sheet 7.

In the alignment joint 10, the side sheets 7, 7 that form the double sheet portion are joined together by the convex portion 11 and adhesive portion 12, so that the thread-like elastic stretch member 9 cannot enter. On the other hand, in other areas, the side sheets 7, 7 that form the double sheet portion are not joined together, so that the thread-like elastic stretch member 9 can enter.

Therefore, by arranging a plurality of the alignment joints 10 side by side at intervals in the width direction at least behind the three-dimensional gather formation section, even if the ends of the thread-like elastic stretchable member 9 contract forcefully when the thread-like elastic stretchable member 9 is cut, the alignment joints 10 suppress undulation in the width direction, so that the ends of the thread-like elastic stretchable member 9 are aligned in the longitudinal direction, improving alignment.

In particular, the alignment joint 10 is formed by combining the convex portion 11 and the adhesive portion 12, and the adhesive portion 12 is provided to fill the gaps of the convex portions 11, so that the adhesive portion 12 completely blocks the space for the thread-like elastic and stretchable member 9 to enter the alignment joint 10, and the alignment of the thread-like elastic and stretchable member 9 can be improved more reliably. If the adhesive portion 12 is not provided, when the thread-like elastic and stretchable member 9 is cut, the end portion may contract forcefully, and the contraction force may cause the end portion to undulate and enter the gaps between the convex portions 11, 11. In addition, if the heat sealing of the convex portions 11 is incomplete, the undulation of the thread-like elastic and stretchable member 9 may release the bond between the side sheets 7, 7, and the thread-like elastic and stretchable member 9 may enter the alignment joint 10.

In addition, the alignment joint 10 has a convex portion 11 formed by bulging the side sheet 7 toward the skin, so that the tip of this convex portion 11 comes into contact with the wearer's skin, and the outline of the convex portion 11 that has hardened by heat sealing and the adhesive portion 12 where the adhesive has solidified are unlikely to come into contact with the skin, resulting in a comfortable feel against the skin.

Furthermore, at least behind the three-dimensional gather formation section, the thread-like elastic stretch member 9 is arranged without being joined to the side sheet 7, so that the end of the sanitary napkin 1 is not bent excessively inward by the contraction force of the thread-like elastic stretch member 9, and the deterioration of the wearing comfort is suppressed.

To form the convex portions 11, the side sheet 7 is folded widthwise on its inner side with the thread-like elastic stretch members 9, 9... arranged on it to form a double sheet portion, and then the side sheet 7 is passed between a first embossing roll on which protrusions corresponding to the convex portions 11 are formed and a second embossing roll on which recesses corresponding to the protrusions of the first embossing roll are formed, and the side sheet 7 is shaped by applying heat or ultrasonic waves to at least the contour portion when the protrusions of the first embossing roll and the recesses of the second embossing roll are engaged.

The convex portion 11 has an outline consisting of a curved line that closes, and a plurality of such convex portions are arranged along the longitudinal direction. The planar shape of the convex portion 11 is circular in the embodiment shown in FIG. 4, but may be (A) a vertically long ellipse, (B) a horizontally long ellipse, (C) a heart shape, etc., as shown in FIG. 6. In this way, by forming the outline of the convex portion 11 with a curved line that closes, even if the side sheet 7 is stretched during the manufacture of the sanitary napkin 1 or during wearing of the sanitary napkin 1, the convex portion 11 is more likely to maintain a protruding state on the skin side, and the wearing comfort can be improved more reliably. When a plurality of convex portions 11 having an outline consisting of a curved line that closes are arranged along the longitudinal direction, a recess in the width direction that separates the convex portions 11 is formed at least on both sides between the adjacent convex portions 11, 11, and the adhesive portion 12 is provided so as to fill this recess.

The dimensions of the protrusions 11 should be 5 mm or less in both the longitudinal and transverse directions in order to reduce the contact area with the skin surface when worn. The height of the protrusions 11 should be such that the contours of the protrusions 11 and the adhesive portion 12 are unlikely to come into contact with the skin surface when worn, and specifically, is 1.5 to 5 mm.

The convex portions 11, 11 adjacent to each other in the longitudinal direction may be arranged in a row so that their contour lines are connected to each other, or may be arranged intermittently at a predetermined distance apart. As shown in FIG. 4, it is preferable to arrange the convex portions 11, 11 so that their contour lines are connected to each other, since this makes it easier to maintain the shape of the convex portions 11 during the manufacture and wearing of the sanitary napkin 1. In either case, the adhesive portion 12 is arranged at least on both sides between the adjacent convex portions 11, 11.

The adhesive portion 12 is a joint formed by applying a hot melt adhesive or the like between the double sheet portions of the side sheet 7. The adhesive portion 12 can be provided by applying an adhesive to at least one of the surfaces of the side sheet portion that is to form the double sheet portion and that faces each other when the double sheet portion is formed.

The adhesive portion 12 is arranged so as to fill at least the gaps on both sides between adjacent convex portions 11, 11 in the longitudinal direction, so that both side edges of the alignment joint 10 are approximately straight along the longitudinal direction. The adhesive portion 12 is preferably arranged at a position where it does not overlap the convex portion 11, but it is acceptable for it to overlap the convex portion 11 to a certain extent. However, if the adhesive portion 12 overlaps the top of the convex portion 11, the adhesive may harden and the top of the convex portion 11 that comes into contact with the skin surface may become hard, so the adhesive portion 12 is arranged so as not to overlap the top of the convex portion 11.

As shown in FIG. 4, when the convex portion 11 is formed in a circular shape, the adhesive portion 12 can be formed in a triangular shape tapered toward the center in the width direction, or in a roughly triangular shape in which the sides facing the contour line of the convex portion 11 are curved and bulge inward.

As shown in FIG. 4, the adhesive portions 12 are arranged in pairs on the left and right sides between adjacent convex portions 11, 11 in the longitudinal direction. In addition, in cases where adjacent convex portions 11, 11 in the longitudinal direction are spaced apart, an adhesive portion connecting the left and right adhesive portions 12, 12 may be provided in the center to form an integrated adhesive portion 12 that is continuous in the width direction. In either case, the adhesive portions 12 should be arranged so that no depressions or gaps are formed on either side between adjacent convex portions 11, 11 in the longitudinal direction.

The alignment joints 10, each consisting of the above-mentioned convex portion 11 and adhesive portion 12, are arranged in a plurality of rows, three in the illustrated example, with a predetermined separation width in the width direction. The separation width between adjacent alignment joints 10, 10 is formed to be greater than the thickness of the thread-like elastic, stretchable member 9, and is preferably about 1.5 to 3 times the thickness of the thread-like elastic, stretchable member 9. If it is less than 1.5 times the thickness of the thread-like elastic, stretchable member 9, the separation width is too small, making manufacturing difficult, and when the thread-like elastic, stretchable member 9 is cut, it is difficult for the thread-like elastic, stretchable member 9 to shrink to within the formation section of the alignment joints 10, 10..., which may result in a state in which the contraction force of the thread-like elastic, stretchable member 9 is applied. On the other hand, if it is more than three times the thickness of the thread-like elastic stretch member 9, when the end of the thread-like elastic stretch member 9 is cut, undulations and twists may occur between the alignment joints 10, 10, and alignment may be reduced.

The longitudinal length of the alignment joint 10 should be from just behind the gather-forming section to the tip of the end of the thread-like elastic stretch member 9 when it is arranged almost straight along the longitudinal direction in a natural state without tensile force acting thereon, and more specifically, it is preferable that the length is from just behind the gather-forming section to about 1/3 of the total length of the sanitary napkin 1. By forming the alignment joint 10 in this range, the ends of the thread-like elastic stretch member 9 are well aligned, and there is no effect on the fit around the legs.

In the embodiment shown in Fig. 4, the alignment joints 10, 10 arranged in parallel in the width direction are arranged at different positions in the width direction between adjacent alignment joints 10, 10, specifically at positions shifted in the longitudinal direction by half a pitch with respect to the arrangement pitch of the protrusions 11, but they may be arranged at the same position in the width direction as shown in Fig. 7. In the area where the protrusions 11 are adjacent, the upper side sheet 7 is pressed toward the lower side at the contour of the protrusions 11, narrowing the gap between the upper and lower side sheets 7, 7. As a result, the braking force when the thread-like elastic stretchable member 9 contracts is thought to be greater than in the area where the adhesive parts 12, which are simply stacked upper and lower side sheets 7, 7, are adjacent. Considering this point, in the embodiment shown in FIG. 4, although the left and right arrangements are reversed on both sides of the thread-like elastic and stretchable member 9, the convex portions 11 and the adhesive portions 12 are continuously arranged on the left and right, respectively, so it is considered that the thread-like elastic and stretchable member 9 contracts while receiving a substantially equal braking force in the section where the alignment joint 10 is provided. On the other hand, in the embodiment shown in FIG. 7, since multiple areas where the convex portions 11, 11 face each other and areas where the adhesive portions 12, 12 face each other are alternately arranged on both sides of the thread-like elastic and stretchable member 9, it is considered that the thread-like elastic and stretchable member 9 contracts while repeatedly receiving larger and smaller braking forces. Thus, although the forms in which the braking force acts are different, the appropriate braking force acts in both cases, reducing the momentum of the contraction force of the thread-like elastic and stretchable member 9 and improving the alignment of the ends of the thread-like elastic and stretchable member 9.

The alignment joints 10 are arranged on both sides of the thread-like elastic stretch member 9, but in the case of the thread-like elastic stretch member 9 arranged at the upright tip in the three-dimensional gather forming section, the upright tip side is the folded-back part of the side sheet 7, and since there is no undulation or twisting of the thread-like elastic stretch member 9 in the upright tip direction, the alignment joints 10 are arranged only on the opposite side.

The manufacturing process of the sanitary napkin 1 having the above-mentioned configuration, which is related to the alignment joint 10, is described in detail below. After the adhesive is applied to a predetermined portion of the side sheet 7 to provide the adhesive portion 12, the thread-like elastic stretch members 9, 9..., which have adhesive applied to a predetermined portion of the portion corresponding to the three-dimensional gather formation section, are placed in a stretched state at a predetermined position of the side sheet 7, and the inner side portion 7a of the side sheet 7 is folded back in the width direction to form a double sheet portion. After that, the side sheet 7 is passed between the first embossing roll and the second embossing roll to form the convex portion 11, and then joined to both sides of the top sheet 3. Then, the side sheet 7 is cut along the product outline. At the same time as this cutting, the thread-like elastic stretch members 9, 9... are cut and contract toward the inside of the double sheet portion of the side sheet 7.

The thread-like elastic stretch members 9, 9... may be the same white color as the side sheet 7, but may also be a color other than white, such as light blue, so that the aligned ends can be clearly seen.

[Other examples]
(1) In the above embodiment, the alignment joint 10 is provided only behind the section where the standing gathers are formed. However, the alignment joint 10 may be provided in front of the section where the standing gathers are formed.

(2) In the above embodiment, multiple (three) thread-like elastic stretch members 9 are arranged, and multiple (three) alignment joints 10 are arranged side by side with intervals in the width direction. However, as shown in FIG. 8, one thread-like elastic stretch member 9 may be arranged at the upright tip in the three-dimensional gather forming section, and one alignment joint 10 may be provided on the side opposite the upright tip (the folded end side of the side sheet 7).

1... sanitary napkin, 2... back sheet, 3... top sheet, 4... absorbent body, 5... covering sheet, 6... compression groove, 7... side sheet, 9... thread-like elastic stretchable member, 10... alignment joint, 11... protruding portion, 12... adhesive portion

Claims (6)

The garment is provided with side sheets arranged along the longitudinal direction on both sides of the skin contact surface side, with a double sheet portion formed on the inner side in the width direction, and a thread-like elastic and stretchable member arranged along the longitudinal direction between the double sheet portions, and three-dimensional gathers are formed in which the inner side portions of the side sheets rise towards the skin in a predetermined longitudinal section including the wearer's body fluid discharge section by the contractile force of the thread-like elastic and stretchable member,
An absorbent article characterized in that, at least behind the section in which the three-dimensional gathers are formed, a plurality of convex portions are arranged along the longitudinal direction, by which the double sheet portion is integrally bulged toward the skin, and an alignment joint is provided in which adhesive portions are arranged to bond the side sheets of the double sheet portion together so as to fill the gaps between the convex portions, and the thread-like elastic stretchable member is arranged along the longitudinal direction in a portion other than the alignment joint, without being joined to the side sheet. The absorbent article according to claim 1, wherein the convex portion has a contour line consisting of a closing curve. The absorbent article according to claim 1 or 2, wherein the adhesive portions are disposed in the widthwise recesses between adjacent longitudinally adjacent protrusions. The absorbent article according to any one of claims 1 to 3, in which a plurality of the thread-like elastic stretch members are arranged, and a plurality of the alignment joints are arranged side by side at intervals in the width direction. The absorbent article according to claim 4, wherein the alignment joints arranged in parallel in the width direction are arranged at the same position in the width direction, or adjacent alignment joints are arranged at different positions in the width direction. The absorbent article according to any one of claims 1 to 5, wherein the thread-like elastic stretchable member has a color other than white.

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