JP3880502B2 - Top sheet for absorbent articles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is for an absorbent article that has a good feel to the wearer and that can quickly transfer liquids such as menstrual blood and urine to the absorbent body and prevent the occurrence of discomfort and skin troubles due to stuffiness. The present invention relates to a surface sheet or an absorbent article.
[0002]
[Prior art and problems to be solved by the invention]
Japanese Patent Application Laid-Open No. 2002-65736 (Patent Document 1) has a liquid-permeable base material and a filament layer provided on the surface of the base material, and both are partially joined to form a plurality of joint portions. Is formed, and an absorbent article including a surface layer in which a filament forms a loop portion between the joint portions is described. Further, the publication describes that the wearer's wearing feeling can be improved by arranging the filament on the liquid receiving side.
However, the surface layer described in the publication does not have a structure that can quickly transfer the liquid discharged on the surface layer to the absorber, and therefore, the liquid remains in the vicinity of the surface. May cause skin problems such as itching and fogging. In particular, when the absorbent article is a sanitary napkin, the color of menstrual blood remaining in the vicinity of the surface is conspicuous, and it is easy to give an unclean impression to the user.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-65736
Therefore, the object of the present invention is that the feel given to the wearer is good, and liquid such as menstrual blood and urine can be quickly transferred to the absorbent body, and it is possible to prevent the occurrence of discomfort and skin trouble due to stuffiness, It is providing the surface sheet or absorbent article for absorbent articles.
[0005]
[Means for Solving the Problems]
The present invention is a topsheet for an absorbent article used on the skin contact surface of the absorbent article, and has a filament layer directed to the wearer's skin side and a base material layer disposed on the absorber side The filament layer and the base material layer are partially joined to form a plurality of joined portions, and the filament layer protrudes toward the wearer's skin at a portion other than the joined portions. A plurality of filaments constituting the filament layer are formed on the skin contact surface side of the filament sheet. When viewed from above, the liquid introduction hole is formed in a substantially central part of the joint in the one direction and so as to extend in a direction perpendicular to the one direction. and, the plan view shape of the liquid guiding holes, the one direction A rectangular shape extending in a direction perpendicular, conductor liquid holes, the said one direction of the opening width W1 of the opening portion of the filament layer side is 20 to 50% of the width W2 of the one-way of the joining portion The above object is achieved by providing a top sheet for absorbent articles.
[0006]
Moreover, the present invention is a method for producing a top sheet for an absorbent article as described above, a step of laminating a filament layer on a base material layer, a step of partially joining the filament layer and the base material layer, For absorbent articles comprising a step of forming a liquid introduction hole at the joint between the filament layer and the base material layer simultaneously with or after the step, and a step of shrinking the base material layer in the horizontal direction after the step A method for producing the top sheet is provided.
[0007]
Further, the present invention provides an absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body of a liquid-holding layer interposed between the two sheets. A filament layer facing the skin side and a base material layer disposed on the absorber side, and the filament layer and the base material layer are partially joined to form a plurality of joints. And the filament layer forms a convex loop portion toward the wearer's skin in a portion other than the joint portion, and a liquid introduction hole penetrating the joint portion is formed in the joint portion. The filaments constituting the filament layer extend in approximately one direction when the top sheet is viewed in plan from the skin contact surface side, and the liquid introduction hole is the one in the joint portion. Formed in the approximate center of the direction and Is formed so as to extend in a direction perpendicular to the one direction, the plan view shape of the liquid guiding hole, a rectangular shape extending in a direction perpendicular to the one direction, conductor liquid holes is of the filament layer side The above object is achieved by providing an absorbent article in which the opening width W1 in one direction of the opening is 20 to 50% of the width W2 in one direction of the joint .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on preferred embodiments thereof.
The surface sheet 1 for absorbent articles as one embodiment of the present invention is used on the skin contact surface of a sanitary napkin (absorbent article) 10 as shown in FIGS. The sheet 1 has a filament layer 2 directed to the wearer's skin side and a base material layer 3 disposed on the absorber side, and the filament layer 2 and the base material layer 3 are partially joined. A plurality of joint portions 4 are formed, and the filament layer 2 forms a convex loop portion 5 toward the wearer's skin side at a portion other than the joint portion 4.
[0009]
The filament layer 2 is composed of a large number of filaments, and each filament is oriented and extended in approximately one direction when the topsheet 1 is viewed in plan (hereinafter, this direction is also referred to as the X direction of the topsheet). .)
The X direction of the topsheet 1 in the present embodiment is the same as the sheet flow direction (machine direction) when the topsheet 1 is manufactured, and the length of the napkin 10 in the state of being incorporated in the sanitary napkin 10. Same as direction.
[0010]
As shown in FIGS. 1 and 2, the filament layer 2 and the base material layer 3 are in the X direction of the topsheet 1 and the direction perpendicular to the X direction in the plane of the topsheet 1 (hereinafter also referred to as the Y direction). In FIG. 2, the joints are intermittently joined to each other, whereby a large number of joints 4 are formed in a staggered pattern in plan view. The joint portion 4 is formed by partially heat-sealing the filament layer 2 and the base material layer 3, and the joint portions 4 respectively connected in series in the X direction and the Y direction of the topsheet 1 are each Is the pitch. The external shape of each joint portion 4 is rectangular in plan view.
As shown in FIG. 3, the filament layer 2 is directed toward the wearer's skin at a portion other than the joint portion 4, specifically, at a portion located between the joint portions 4 and 4 adjacent to each other in the X direction. It protrudes so as to protrude greatly in the direction, and the protruding portion forms a large number of loop portions 5 having spaces inside.
[0011]
The filament constituting the filament layer 2 has a length extending between adjacent joints in the X direction of the topsheet 1. As the filament constituting the filament layer 2, for example, a filament that has been fibrillated from a convergent body of crimped filaments called “tow” can be used.
[0012]
A liquid introduction hole 6 is formed in each joint portion 4 in the topsheet 1 of the present embodiment. As shown in FIG. 3, each liquid introduction hole 6 penetrates the joint portion 4 (filament layer 2 and base material layer 3), and has an opening 61 on the filament layer 2 side and an opening 62 on the base material layer 3 side. Have.
The shape of the openings 61 and 62 of the liquid introduction hole 6 is a rectangular shape that is substantially similar to the outer shape of the joint portion 4, and the liquid introduction hole 6 is formed at a substantially central portion in the X direction of each joint portion 4. Yes.
As shown in FIG. 3, the liquid guide hole 6 has a top sheet 1 having a substantially inverted trapezoidal cross section in the X direction and a substantially rectangular cross section in the Y direction. The cross-sectional area of the horizontal cross section of the liquid introduction hole 6 gradually decreases from the opening 61 on the filament layer 2 side toward the opening 62 on the base material layer 3 side. By making the opening 62 on the base material layer 3 side smaller than the opening 61 on the filament layer 2 side, the liquid is smoothly guided from the skin contact surface to the absorption layer, and the remaining liquid on the surface is further reduced.
Moreover, although not shown in figure, the opening peripheral part of the opening part 62 by the side of the base material layer 3 protrudes to the absorber 12 side. Therefore, the liquid introduction effect is improved and the liquid can be prevented from staying at the joint.
[0013]
From the viewpoint of smoothly transferring the liquid (eg menstrual blood) excreted on the top sheet 1 to the absorbent body 12 of the napkin 10, the opening on the filament layer 2 side in the X direction (filament orientation direction) of the top sheet 1 61 opening width W1 (refer FIG. 3) is 20 to 50% of width W2 (refer FIG. 3) of the junction part 4 of the same direction . From the same viewpoint, the opening width W1 is preferably 0.5 to 3 mm, particularly preferably 1 to 2 mm, and the width W2 of the joint is preferably 2.5 to 5 mm, particularly 3 to 4 mm.
From the same viewpoint, the liquid introduction hole 6 has an opening area of the opening 61 on the filament layer 2 side of 1.5 to 9 mm2, and an opening area of the opening 62 on the base material layer 3 side of 1 to 6 mm2. It is preferable that the ratio of the opening areas of both openings (opening area of the opening 61 / opening area of the opening 62) is 1.5 to 9.
[0014]
A plurality of thread-like or string-like elastic members 7 are fixed in parallel on one surface (surface on the absorber 12 side) of the base material layer 3 in the topsheet 1 of the present embodiment. By contracting in the X direction of the sheet 1, the base material layer 3 is similarly contracted in the X direction of the topsheet 1.
The elastic member 7 imparts shrinkage to the base material layer 3, and is stretched in the X direction, fixed to the base material layer that is also stretched to some extent in the X direction, and then stretched. By releasing, the base material layer 3 is in a contracted state. As shown in FIG. 2, the elastic member 7 in the present embodiment is arranged so as to pass through the vicinity of the center portion in the Y direction of each loop portion and is cut at the liquid introduction hole 6 portion. Can also be arranged continuously in the X direction. In that case, the elastic member 7 can be arranged so as to avoid the liquid introduction hole 6 part, or can be arranged so as to cross the liquid introduction hole 6. The elastic member 7 is fixed to one surface of the base material layer 3 by various known joining means such as an adhesive.
[0015]
The material for forming the topsheet 1 of this embodiment will be described.
The filament constituting the filament layer 2 is preferably a heat-fusible fiber, particularly a fiber made of a thermoplastic polymer material so that the filament layer 2 can be bonded to the base material layer 3 by heat-sealing. Examples of the thermoplastic polymer material include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, and polyamides. A core-sheath type or side-by-side type composite fiber made of a combination of these thermoplastic polymer materials can also be used. Furthermore, melt blown fibers, split yarns and the like can also be used.
[0016]
Examples of the material for forming the base material layer 3 include non-woven fabrics, perforated films, and laminated sheets of non-woven fabrics and perforated films produced by various manufacturing methods, and non-woven fabrics are particularly preferable. As a nonwoven fabric, a nonwoven fabric formed by a heat fusion method, a nonwoven fabric formed by a hydroentanglement method, a nonwoven fabric formed by a needle punch method, a nonwoven fabric formed by a solvent bonding method, a nonwoven fabric formed by a spunbond method, Nonwoven fabrics formed by the meld blown method are listed.
As the fiber constituting the nonwoven fabric, a fiber made of a thermoplastic polymer material is preferable from the viewpoint of enabling the base material layer 3 and the filament layer 2 to be heat-sealed and obtaining high bonding strength. Examples of the thermoplastic polymer material include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, and polyamides. A core-sheath type or side-by-side type composite fiber made of a combination of these thermoplastic polymer materials can also be used. Moreover, you may mix hydrophilic fibers, such as rayon and cotton.
[0017]
Examples of the material for forming the elastic member 7 include natural rubber, synthetic rubber such as styrene-butadiene, butadiene, isoprene, and neoprene, EVA, stretchable polyolefin, urethane, and the like. As a form of the elastic member 7, a net-like member can be used in addition to a thread-like or string-like member.
[0018]
Next, an embodiment of a method for producing a top sheet for absorbent articles according to the present invention will be described with reference to FIG.
First, a plurality of elastic members 7 are fixed to one surface of the base material layer 3 continuously conveyed in one direction in a state where the elastic members 7 are stretched in the flow direction of the base material layer 3 by a known joining means such as an adhesive. To do. At the time of fixing, it is preferable that the base material layer 3 is also stretched to some extent.
[0019]
Next, the filament layer 2 is laminated on the other surface of the base material layer 3. Then, the obtained laminate is inserted between a convex roll 81 having a large number of convex portions 82 for forming joint portions on a peripheral surface and a receiving roll 84 arranged to face the convex roll 81, and the convex By pressing and heating between the portion 82 and the peripheral surface of the receiving roll 84, the base material layer 3 and the filament layer 2 are partially heat-sealed to form the joint portion 4. Both rolls 81 and 84 heat at least the convex portion 82.
Note that the convex roll 81 shown in FIG. 4 has a projection 83 having a substantially triangular cross section for forming the introduction hole 6 at the center of each convex portion 82. Are formed simultaneously. The receiving roll 84 is formed of a material whose outer peripheral portion has compression elasticity.
[0020]
After the joint 4 and the liquid introduction hole 6 are formed, the stretched state of the elastic member 7 is released. Thereby, the base material layer 3 contracts together with the elastic member 7, and accordingly, a portion of the filament layer 2 located between adjacent joints is raised on the side opposite to the base material layer 3, and the loop portion 5 is formed. In this way, the top sheet 1 is obtained.
[0021]
According to the topsheet 1 for absorbent articles of the present embodiment and the sanitary napkin (absorbent article) 10 using the topsheet 1 as a skin contact surface, it is worn on the surface facing the wearer's skin side. Since the loop part 5 made of the filament layer 2 that is excellent in follower deformability with respect to the movement and unevenness of the skin is formed, the feel given to the wearer during wearing is good.
In addition, the liquid (such as menstrual blood) that has flowed toward the absorber 12 through the gap between the loop portions 5 or between adjacent loop portions does not stay in the vicinity of the joint portion 4 formed by thermal fusion, so that the liquid is introduced. Since it smoothly moves into the absorbent body 12 through the holes 6, the discharged liquid (eg, menstrual blood) stays in the vicinity of the surface of the sheet. Can be prevented. The sanitary napkin 10 shown in FIG. 1 or 3 includes a top sheet 1 as a liquid-permeable top sheet, a liquid-impermeable back sheet 11, and a liquid holding layer interposed between the two sheets. And the absorber 12.
[0022]
Moreover, according to the manufacturing method of the surface sheet of this embodiment, such a surface sheet 1 can be manufactured efficiently with simple equipment.
[0023]
As mentioned above, although preferable embodiment of this invention was described, this invention is not restrict | limited to embodiment mentioned above, It can change suitably.
For example, the loop portion 5 in the surface sheet 1 described above is provided with elastic stretchability to the base material layer 3 by the elastic member 7 fixed to the base material layer 3, and the filament layer 2 using the elastic stretchability. However, it is also possible to form the loop portion 5 by using the base material layer 3 itself having elastic elasticity and utilizing the contraction force. For example, a base material layer 3 having elastic stretchability is formed from a nonwoven fabric or fiber web obtained by mixing an elastic material made of spandex, natural rubber or the like chemically cross-linked by heating into constituent fibers, and this elastic stretch The loop part 5 can also be generated using the property.
[0024]
Moreover, the loop part 5 can also be produced using the shrinkage force of the base material layer 3 that shrinks by a predetermined treatment. As a material for forming the base material layer 3 that shrinks by a predetermined treatment, a non-woven fabric or fiber web (including 100% heat-shrinkable fibers) that shrinks by heat treatment, a perforated sheet that shrinks by heat treatment, or the like is used. In particular, from the viewpoint of easy processing and easy control of the shrinkage level, those mainly composed of latent crimpable fibers that are crimped by heat treatment (those composed of 100% latent crimpable fibers). Can be preferably used.
The latent crimpable fiber is a fiber that can be handled in the same manner as a conventional nonwoven fabric fiber before being heated, and has a property that a helical crimp is developed and contracted by heating at a predetermined temperature. is there. The latent crimpable fiber includes, for example, an eccentric core-sheath type composite fiber or a side-by-side type composite fiber containing two types of thermoplastic polymer materials having different shrinkage rates as components. Examples thereof include those described in JP-A-9-296325 and Japanese Patent No. 2759331.
[0025]
FIG. 5 is a diagram showing a main part of another preferred embodiment (hereinafter also referred to as a second embodiment) of the present invention. About 2nd Embodiment, a different point from the surface sheet 1 mentioned above is mainly demonstrated, and description is abbreviate | omitted about the same point.
In the topsheet of the second embodiment, the filament layer 2 is laminated on the base material layer 3 containing a predetermined amount of latent crimpable fibers and contracted by heat treatment, and both the layers are partially bonded by heat fusion. The liquid introduction hole 4 is formed in the joint portion 4, and then the base material layer 3 is thermally contracted in both the X direction and the Y direction in FIG. 5.
Therefore, in each loop part 5 ′ in the present embodiment, the filament density in the Y direction increases (is denser) from the top part 51 toward the joint part 4. The loop portion 5 ′ has a substantially fan shape when viewed from the X direction, and a substantially inverted U shape or a substantially Ω shape when viewed from the Y direction. In the surface sheet of the present embodiment, the plurality of filaments constituting the filament layer 2 extend substantially in one direction (X direction) when the surface sheet is viewed from the skin contact surface side. The Y direction is a direction orthogonal to the one direction (X direction). Content in the base material layer of a latent crimpable fiber can be 50-100 weight%, for example, and 80-100 weight% is preferable.
[0026]
According to the top sheet of the second embodiment and the sanitary napkin (absorbent article) using the top sheet as the skin contact surface, the same effects as the top sheet 1 and the sanitary napkin 10 described above are exhibited. In addition, since the filaments are densely present from the top portion 51 toward the joint portion 4, the liquid introduction effect is further enhanced by the density gradient between the fibers, and the liquid easily moves to the liquid introduction hole. The effect of becoming.
[0027]
In the manufacturing example of the topsheet 1 described above, the joint 4 and the liquid introduction hole 6 are formed at the same time. However, the process of forming the joint 4 and the process of forming the liquid introduction hole 6 may be separated. In the manufacturing example, the elastic member 7 is fixed to the base material layer 3 before the filament layer 2 and the base material layer 3 are laminated. However, the elastic member 7 is elastic after the filament layer 2 and the base material layer 3 are laminated. The member 7 can also be fixed. In this case, the elastic member 7 may be fixed before or after the filament layer 2 and the base material layer 3 are joined.
[0028]
The shape of the joint portion 4 of the topsheet may be a square shape, a rhombus shape, a parallelogram shape, an ellipse shape, etc. in addition to a rectangular shape in plan view. Moreover, the shape of the liquid introduction hole 6 can also be made into a rhombus shape, a parallelogram shape, etc., for example in a plan view. The number of liquid introduction holes 6 formed in one joint portion 4 is not limited to one, and for example, about 2 to 5 can be provided. Further, the top sheet may be used with the X direction aligned with the width direction of the sanitary napkin (absorbent article), and a part of the skin contact surface of the sanitary napkin, for example, the wearer's liquid discharge You may use only for the site | part arrange | positioned facing a part.
[0029]
Examples of the absorbent article according to the present invention include sanitary napkins, panty liners, incontinence pads, disposable diapers and the like.
[0030]
【The invention's effect】
According to the surface sheet and absorbent article for absorbent articles of the present invention, the feel given to the wearer is good, and liquid such as menstrual blood and urine is quickly transferred to the absorbent body, so that discomfort caused by stuffiness and skin Trouble can be prevented.
According to the method for producing a surface sheet for an absorbent article of the present invention, the feel given to the wearer is good, and liquid such as menstrual blood and urine is quickly transferred to the absorbent body, causing discomfort and skin trouble due to swelling. The surface sheet for an absorbent article that can prevent the occurrence of water can be efficiently and economically manufactured with a simple apparatus.
[Brief description of the drawings]
FIG. 1 is a partially enlarged perspective view showing a top sheet for an absorbent article and a sanitary napkin using the same according to an embodiment of the present invention.
2 is a partially enlarged plan view of a part of the topsheet shown in FIG. 1 as viewed from the filament layer side.
FIG. 3 is an enlarged cross-sectional view showing an enlarged cross section in the thickness direction of the topsheet shown in FIG. 1;
FIG. 4 is a schematic view showing one embodiment of a method for producing a surface sheet for absorbent articles according to the present invention.
FIG. 5 is a partially enlarged perspective view showing a main part of a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Top sheet | seat for absorbent articles 2 Filament layer 3 Base material layer 4 Joint part 5, 5 'Loop part 6 Liquid introduction hole 7 Elastic member 10 Sanitary napkin (absorbent article)
11 Back sheet 12 Absorber

Claims (6)

A surface sheet for absorbent articles used on the skin contact surface of the absorbent article,
It has a filament layer directed to the wearer's skin side and a base material layer disposed on the absorber side, and the filament layer and the base material layer are partially joined to form a plurality of joints. And the filament layer forms a convex loop portion toward the wearer's skin side in a portion other than the joint portion,
A liquid introduction hole penetrating the joint is formed in the joint,
The plurality of filaments constituting the filament layer extend in approximately one direction when the top sheet is viewed in plan from the skin contact surface side, and the liquid introduction hole is substantially in the one direction at the joint. Formed in the center and extending in a direction perpendicular to the one direction ,
The shape of the liquid introduction hole in a plan view is a rectangular shape extending in a direction orthogonal to the one direction, and the liquid introduction hole has an opening width W1 in the one direction of the opening on the filament layer side. The surface sheet for absorbent articles which is 20 to 50% of the width W2 in the one direction . The liquid guiding hole, the topsheet of the absorbent article according to claim 1, wherein the cross-sectional area of the horizontal cross section brought from the opening of the filament layer side toward the opening portion of the base layer side is reduced. The top sheet for absorbent articles according to claim 1 or 2 , wherein the liquid introduction hole has an opening peripheral edge of the opening on the base material layer side protruding toward the absorber. The plurality of filaments constituting the filament layer extend in approximately one direction when the surface sheet is viewed in plan from the skin contact surface side, and the loop portion is directed from the top portion toward the joint portion. The surface sheet for absorbent articles according to any one of claims 1 to 3 , wherein the existence density of the filaments in a direction orthogonal to one direction is increased.   It is a manufacturing method of the surface sheet for absorbent articles of Claim 1, Comprising: The process of laminating | stacking a filament layer on a base material layer, The process of partially bonding this filament layer and this base material layer, This process, A method for producing a surface sheet for an absorbent article, comprising the step of forming a liquid introduction hole at the joint between the filament layer and the base material layer, or the step of shrinking the base material layer after the step. . In an absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent of a liquid-holding layer interposed between the two sheets,
The surface sheet has a filament layer directed to the wearer's skin side and a base material layer disposed on the absorber side, and the filament layer and the base material layer are partially joined to each other. Are formed, and the filament layer forms a convex loop portion toward the wearer's skin side in a portion other than the joint portion,
A liquid introduction hole penetrating the joint is formed in the joint,
The plurality of filaments constituting the filament layer extend in approximately one direction when the top sheet is viewed in plan from the skin contact surface side, and the liquid introduction hole is substantially in the one direction at the joint. Formed in the center and extending in a direction perpendicular to the one direction ,
The shape of the liquid introduction hole in a plan view is a rectangular shape extending in a direction orthogonal to the one direction, and the liquid introduction hole has an opening width W1 in the one direction of the opening on the filament layer side. The absorbent article which is 20 to 50% of the width W2 in the one direction .

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