JP6668522B2 - Absorbent articles - Google Patents

Description

The present invention relates to an absorbent article used for an incontinence pad, a panty liner, a sanitary napkin, and the like, and particularly to a bonding between a topsheet containing cellulosic fibers and a second sheet disposed on the non-skin side of the topsheet. It relates to an absorbent product article with enhanced strength.

  Conventionally, as absorbent articles for women such as incontinence pads, panty liners and sanitary napkins, paper cotton such as pulverized pulp is provided between a liquid-impervious back sheet such as a polyethylene sheet or a polyethylene sheet laminated non-woven fabric and a top sheet. There is known an absorber interposed by an absorber composed of:

  Since the topsheet forms a skin-contacting surface, it is required that the topsheet be flexible, have a dry touch even after excretion is absorbed, and have little irritation to the skin. As materials satisfying such demands, nonwoven fabrics of synthetic fibers and mesh sheets made of resin are widely used in the field of absorbent articles. However, the topsheet made of synthetic fibers has not been sufficiently satisfactory in that itching, rash and the like are likely to occur.

  As a solution to this problem, a surface sheet made of cotton fiber (cotton fiber) has been proposed. The topsheet made of cotton fiber has the advantage of realizing a soft touch like underwear, but in absorbent articles, the topsheet has high liquid permeability and allows the liquid to be transferred to the absorbent quickly. On the other hand, when ordinary absorbent cotton fibers are contained in the topsheet, there is a problem that the topsheet itself has a high liquid retention property and sticky feeling is easily left on the surface.

  In order to improve such a problem, Patent Document 1 listed below discloses that a topsheet is made of a cotton nonwoven fabric, and a lower fiber density than that of the above-mentioned cotton nonwoven fabric is provided between a lower layer of the topsheet and an absorber. There is disclosed an absorbent article in which a large number of embosses are applied from the surface side in a laminated state of these heat-fusible fiber sheets having hydrophilic properties.

  Also, in Patent Document 2 below, at least two sheets each including a first fiber layer made of cotton and a thermoplastic resin fiber and a second fiber layer made of a hydrophobic thermoplastic resin fiber are provided. A non-woven fabric comprising a fibrous layer of a layer, wherein the non-woven fabric has a first surface formed by the second fiber layer on the skin-facing surface side, and an absorbent material on the non-skin-facing surface side. An opposing second surface, wherein the nonwoven fabric is provided between a plurality of protrusions protruding toward the first surface and the adjacent protrusions, and faces the second surface. An absorptive article comprising a plurality of recesses that are depressed, wherein the protrusions have voids facing the second surface of the nonwoven fabric.

JP 2009-148328 A JP-A-2006-220986

  However, in the absorbent article described in Patent Literature 1, since the embossing is performed by squeezing from the outer surface side of the cotton nonwoven fabric facing the surface side, that is, the skin surface, the embossing roll is formed by embossing. A non-heat-fusible cotton nonwoven fabric is interposed between the tip of the provided embossed convex portion and the heat-fusible fiber layer. For this reason, the heat at the tip of the embossed convex portion is not sufficiently transmitted to the heat-fusible fiber, and the bonding strength between the second sheet and the topsheet arranged on the non-skin side of the topsheet tends to be low. There was a drawback that the body fluid was difficult to transfer to the second sheet.

  In addition, if uneven processing involving heating is performed on the cotton non-woven fabric, the fibers may be entangled due to hydroentanglement of the cotton non-woven fabric and the fiber ends may fly out or the cotton non-woven fabric may be broken. There has been a problem of deterioration of the feel due to impaired properties and a decrease in strength.

  On the other hand, in the absorbent article described in Patent Literature 2, since the layer containing cotton is disposed on the non-skin-facing surface side of the topsheet that does not directly touch the skin, the soft touch of cotton cannot be utilized. .

  Therefore, a main object of the present invention is to provide an absorbent article that allows the body fluid absorbed by the topsheet to migrate to the non-skin side without reducing the soft touch of cotton.

In order to solve the above-mentioned problems, as the present invention according to claim 1, in an absorbent article in which an absorber is interposed between a top sheet and a back sheet,
Consists of a non-heat sealable layer consisting of cellulosic fibers in which the surface sheet is arranged on the skin side, a thermal adhesive layer comprising a heat-fusible fibers disposed on the non-skin side, the non-heat The bonding layer and the heat-sealing layer are joined with each other by entanglement of the fibers,
On the non-skin side of the top sheet, a second sheet made of heat-fusible fibers is provided, and on the non-skin side surface of the second sheet, the second sheet and the top sheet are squeezed from the non-skin side of the second sheet. A large number of pressed parts are formed integrally and depressed toward the skin side, the heat-sealing layer and the second sheet are fixed to each other in the pressed part, and the laminate of the top sheet and the second sheet is An absorbent article characterized in that the skin side is formed flat . Is provided.

According to the first aspect of the present invention, since the non-heat-sealing layer made of cellulosic fiber is provided on the skin contact surface of the topsheet, the soft touch of cellulosic fiber (for example, cotton fiber) can be obtained. Become like Further, the topsheet is composed of a skin-side non-heat-fusion layer and a non-skin-side heat-fusion layer, and the non-heat-fusion layer and the heat-fusion layer are joined by intermingling fibers of each other. ing. Then, with the second sheet made of the heat-fusible fiber disposed on the non-skin side of the top sheet, the second sheet is squeezed from the non-skin side of the second sheet on the non-skin side surface of the second sheet. Also, since a large number of squeezed portions in which the topsheet is integrally depressed toward the skin side are formed, the second fusible sheet and the heat-sealable layer of the topsheet (non-skin side layer) are formed by the squeezed portions. ) Is firmly joined, and the bodily fluid is easily transferred from the top sheet to the second sheet disposed below the top sheet. In addition, the squeezed portion, by squeezing from the non-skin side of the top sheet, the second sheet and the heat-sealing layer constituting the non-skin side layer of the top sheet are heat-sealed, The non-heat-fused layer made of cellulosic fibers is not squeezed while being heated to a high temperature, and the fibers of the non-heat-fused layer are unentangled due to heating or squeezing, and the nonwoven fabric is broken. In addition, since the laminate of the top sheet and the second sheet has a flat skin side surface, the smoothness of the surface can be maintained, and deterioration of the touch and reduction in strength can be prevented.

Above Symbol onset Ming, bonding of the non-thermally fusing layer and the heat sealable layer is We rows by entangling each other fibers such as hydroentanglement. This prevents the transfer of bodily fluids from being hindered by the adhesive or the like when joined by an adhesive or the like, and facilitates the transfer of bodily fluids from the non-heat-fusion layer to the heat-fusion layer through fibers entangled with each other. In addition, since the bonding strength is not so high, there is an advantage that the influence of heating and pressing on the non-heat-bonded layer is reduced when the heat-bonded layer is heated and pressed.

As the present invention according to claim 2, wherein the second sheet, the absorbent article according to claim 1 Symbol placement than the heat sealable layer is formed of a low basis weight, low density is provided.

In the invention described in claim 2, wherein said second sheet, by forming in the low basis weight, low density than the heat sealable layer of the topsheet, more bond the second sheet and the heat-fusible layer by the compressing portion I am strong.

According to a third aspect of the present invention, there is provided the absorbent article according to any one of the first and second aspects, wherein the squeezed portions are formed in a plurality of intermittent patterns arranged at intervals.

According to the third aspect of the present invention, the entire area of the pressed portion can be reduced by forming the pattern of the pressed portion as an intermittent pattern arranged in large numbers at intervals, and the non-heat-sealing layer is formed. The touch (smoothness) and strength can be reliably maintained.

According to a fourth aspect of the present invention, there is provided the absorbent article according to any one of the first to third aspects, wherein the non-heat-fusion layer is formed of 100% by weight of cotton fibers.

According to the fourth aspect of the present invention, by forming the non-heat-fusion layer with 100% by weight of cotton fibers, the surface sheet can be particularly excellent in flexibility and feeling.

According to a fifth aspect of the present invention, there is provided the absorbent article according to any one of the first to fourth aspects, wherein the heat-sealing layer does not include a non-heat-sealing fiber.

In the invention according to the fifth aspect , in order to further increase the bonding strength between the heat-sealing layer and the second sheet, the heat-sealing layer does not include non-heat-sealing fibers such as cellulosic fibers. It has a configuration.

  As described in detail above, according to the present invention, it is possible to provide an absorbent article that can transfer bodily fluids absorbed by the topsheet to the non-skin side without reducing the soft touch of cotton.

FIG. 2 is a partially exploded development view of the sanitary napkin 1 according to the present invention. FIG. 2 is a view taken along line II-II in FIG. 1. FIG. 3 is a view taken along line III-III in FIG. 1. FIG. 3 is an enlarged cross-sectional view of a top sheet 3 and a second sheet 6 near a pressing unit 15. FIG. 4 is an enlarged plan view of the topsheet 3. It is sectional drawing which shows the 1st manufacturing method. It is sectional drawing which shows the 2nd manufacturing method.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Example of basic structure of sanitary napkin>
As shown in FIGS. 1 to 3, the sanitary napkin 1 according to the present invention has a liquid-impermeable back sheet 2 made of a polyethylene sheet or the like, forms a skin contact surface, and has a surface through which body fluids can be transmitted quickly. A sheet 3, an absorbent body 4 made of cotton-like pulp or synthetic pulp interposed between the sheets 2 and 3, and at least one of the absorbent bodies 4 for maintaining the shape of the absorbent body 4 and improving the diffusivity; Envelope sheet 5 made of crepe paper or nonwoven fabric covering skin side and non-skin side, second sheet 6 interposed between top sheet 3 and absorber 4, and substantially side edge of absorber 4 A pair of left and right three-dimensional gathers BS provided to protrude toward the skin in a predetermined section in the front-rear direction so as to include at least the body fluid discharging portion H of the wearer, and a side nonwoven fabric 7 forming BS. From 7 In the periphery of the absorber 4, the outer edges of the back sheet 2 and the top sheet 3 at the upper and lower edges thereof are bonded by an adhesive such as hot melt, a heat seal, or an ultrasonic seal. The back sheet 2 and the side non-woven fabric 7 which are joined and which extend on both side edges to the side from the absorber 4 are joined by an adhesive such as hot melt or a joining means such as heat sealing or ultrasonic sealing. Have been. In the illustrated example, the absorber 4 has a one-layer structure, but may have a multilayer structure forming a middle and high part, or a multilayer structure in which absorbers having the same size and shape are stacked.

  As the back sheet 2, a sheet material having at least water-blocking properties, such as polyethylene, is used. In recent years, a sheet having moisture permeability has been used from the viewpoint of preventing stuffiness. The water-impervious and moisture-permeable sheet material is a microporous material obtained by melting and kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching the sheet uniaxially or biaxially. Sheets are preferably used. One or a plurality of pressure-sensitive adhesive layers (not shown) are formed on the non-use surface side (outer surface) of the back sheet 2 so that the sanitary napkin 1 is fixed to the underwear when worn on the body. As the back sheet 2, a poly-laminate non-woven fabric in which a plastic film and a non-woven fabric are laminated may be used.

  The absorber 4 is capable of absorbing and retaining bodily fluids, and is a mixture of fluffy pulp fibers and a powdery superabsorbent polymer dispersed therein, or an upper layer sheet disposed on the skin side and a non-skin layer. A polymer sheet having a superabsorbent polymer interposed in a predetermined region between the lower sheet and a lower layer sheet disposed on the side can be used.

Examples of the pulp fiber include chemical pulp obtained from wood, cellulose fiber such as dissolved pulp and the like, and rayon and artificial cellulose fiber such as acetate. And it is preferably used in terms of price. The basis weight of the pulp fiber is 150 to 500 g / m ² , preferably 250 to 400 g / m ^2, and the basis weight of the superabsorbent polymer is 70 to 470 g / m ² , preferably 140 to 240 g / m ² . m ² is preferable.

  Examples of the superabsorbent polymer include a crosslinked product of polyacrylate, a self-crosslinked polyacrylate, a crosslinked product of an acrylate-vinyl acetate copolymer, a crosslinked product of isobutylene / maleic anhydride copolymer, Examples thereof include crosslinked polysulfonates and partially crosslinked water-swellable polymers such as polyethylene oxide and polyacrylamide. Of these, acrylic acid or acrylate-based compounds having excellent water absorption and water absorption speed are preferable. In the production process of the superabsorbent polymer having the water absorbing performance, the absorption capacity (water absorption power) and the absorption rate can be adjusted by adjusting the crosslinking density and the crosslinking density gradient.

In the illustrated example, the width of the topsheet 3 is slightly larger than the width of the absorber 4, and only covers the top of the absorber 4, and the outer side in the width direction of the topsheet 3 extends from both side surfaces of the topsheet 3. Side nonwoven fabric 7 (a member different from the topsheet 3). The central portion in the width direction of the side nonwoven fabric 7 forms a three-dimensional gather BS. As the side nonwoven fabric 7, a nonwoven fabric material that has been subjected to an appropriate water-repellent treatment or hydrophilic treatment can be used according to the purpose of preventing body fluid from penetrating or enhancing the feel of touch. As the side nonwoven fabric 7, a material formed by using a natural fiber, a synthetic fiber, a regenerated fiber, or the like as a material by an appropriate processing method can be used. For this purpose, it is preferable to use a nonwoven fabric having a reduced basis weight and air permeability. Specifically, it is desirable to use a nonwoven fabric made with a basis weight of 15 to 23 g / m ² , and coated with a silicon-based or paraffin-based water repellent to surely prevent the permeation of bodily fluids. The water-repellent treated nonwoven fabric is preferably used.

  As shown in FIGS. 2 and 3, the side nonwoven fabric 7 extends from the inner portion of the absorber 4 to the outer edge of the back sheet 2 slightly beyond the side edge of the absorber from the middle portion in the width direction to the outer edge. It is adhered by an adhesive such as hot melt.

  On the other hand, the inner side portion of the side non-woven fabric 7 is substantially double-folded, and one or more of the double-sided sheets are fixed inside the double sheet at both ends or at appropriate positions in the longitudinal direction at an intermediate portion in the height direction. In the illustrated example, two thread-like elastic elastic members 8 and 8 are arranged in a state where both ends or appropriate positions in the longitudinal direction are fixed. As shown in FIG. 3, the double sheet portion is fixed to the top sheet 3 in a folded state at the front and rear ends.

<Top sheet>
The topsheet 3 forms a skin contact surface, which is a portion that covers the skin side of the absorber 4, and as shown in FIG. 4, non-thermal fibers made of cellulosic fibers disposed on the skin side. It has a multilayer structure including a fusion layer 10 and a thermal fusion layer 11 made of thermally fusible fibers disposed on the non-skin side. It is desirable that the topsheet 3 has a two-layer structure including the non-heat-fusion layer 10 and the heat-fusion layer 11, but an intermediate layer made of a cellulosic fiber or a synthetic fiber may be provided between them. Good.

  The non-heat-sealing layer 10 forming the skin contact surface of the topsheet 3 is made of a nonwoven fabric containing hydrophilic cellulosic fibers. Examples of the hydrophilic cellulosic fibers include natural fibers such as cotton fibers (cotton fibers) and pulp fibers, and artificial cellulosic fibers such as rayon fibers, acetate fibers, and lyocell fibers. Examples of the cotton fiber include cotton raw cotton, smelted / bleached cotton fiber, or smelted / bleached, dyed cotton fiber, smelted / bleached absorbent cotton fiber, and defibrated yarn or fabric. Any kind of cotton fiber such as wool can be used, but in order to enhance the liquid absorption speed and diffusivity in the lower layer sheet, use a defatted cotton fiber obtained by defatting the natural oils and fats of cotton wax, which is attached to the surface of the cotton fiber. Is preferred.

  The non-heat-sealing layer 10 is preferably made of a spunlace nonwoven fabric made of 100% by weight of cotton fiber. By using only cotton fibers, a soft touch can be obtained, and even when worn for a long time, skin troubles such as itchiness and rash can be prevented from occurring when worn. Spunlaced nonwoven fabrics also have advantages such as not using an adhesive and having flexibility.

The basis weight of the non-heat-fusion layer 10 is preferably 10 to 30 g / m ^2, and more preferably 10 to 15 g / m ² so that the flexibility and texture of the cellulosic fiber can be exhibited. The basis weight of the nonwoven fabric was obtained by cutting a sample having a size of 50 mm × 50 mm (± 2 mm), measuring the weight, and converting the weight into the weight per 1 m ² . When many openings are formed in a partial region of the nonwoven fabric, the measurement is performed using the nonwoven fabric in a region where no openings are formed. When a large number of openings are formed on the entire surface of the nonwoven fabric, a large number of portions where there are no openings are cut out, and the total weight of the cut out portions is 2500 mm ^2, and the total weight is measured. The basis weight can be obtained by dividing by the area.

  As the heat-sealing layer 11 forming the non-skin contact surface of the topsheet 3, a perforated or non-porous nonwoven fabric is used. As a fiber material of the nonwoven fabric, synthetic fibers are contained. For example, in addition to thermoplastic synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra and natural fibers such as cotton can be included in these synthetic fibers. As the nonwoven fabric, a nonwoven fabric obtained by an appropriate processing method such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, and a needle punch method can be used. Among these processing methods, the spunlace method is excellent in that it is rich in flexibility and drapability, and the thermal bond method is excellent in that it is bulky and has high compression recovery. Since the heat-fusible layer 11 is made of a nonwoven fabric containing synthetic fibers, the bondability can be enhanced by the heat fusion of the heat-fusible fibers, and the heat-fusible layer 11 is less likely to retain liquid, and Is improved, and the phenomenon that the body fluid is held in the heat-sealing layer 11 and returns to the skin side is less likely to occur.

  It is preferable that the heat-fusible layer 11 does not contain non-heat-fusible fibers, specifically, the above-mentioned cellulosic fibers, and is composed of only heat-fusible fibers, specifically, synthetic fibers. preferable. As will be described in detail later, since the heat-fused layer 11 is heat-sealed to the lower second sheet 6 in the press unit 15, if the non-heat-fusible fibers are contained, the press unit In the case of No. 15, heat fusion is difficult, and there is a possibility that the bonding strength between the heat fusion layer 11 and the second sheet 6 is reduced.

The basis weight of the heat-sealing layer 11 is preferably larger than the basis weight of the non-heat-sealing layer 10, specifically, 10 to 40 g / m ² , preferably 15 to 20 g / m ^2. . By making the basis weight of the heat fusion layer 11 larger than that of the non-heat fusion layer 10, when the second sheet 6 and the heat fusion layer 11 are squeezed while being heated, the influence on the non-heat fusion layer 10 is reduced. .

  It is desirable that the non-heat-sealing layer 10 and the heat-sealing layer 11 be joined by a predetermined joining method. If the layers 10 and 11 are provided in a state of being simply laminated without being joined, the strength of the non-heat-fusion layer 10 made of the cellulosic fiber is weak, and it is not preferable because the layer is easily broken. That is, it is preferable that the non-heat-sealing layer 10 is joined to the heat-sealing layer 11 so that the non-heat-sealing layer 10 is reinforced by the heat-sealing layer 11 and the top sheet 3 can be prevented from being broken. Further, when the surface sheet has the same basis weight, the synthetic fiber has a laminated structure of the non-heat-fusion layer 10 and the heat-fusion layer 11 as compared with the case where the top sheet has only the non-heat-fusion layer 10. In order to reduce the amount of cellulose fiber used, which is more expensive, the cost of the topsheet 3 can be reduced, and the laminated structure in which the non-heat-fused layer 10 and the heat-fused layer 11 are joined is also preferable. preferable.

  It is preferable that the non-heat-sealing layer 10 and the heat-sealing layer 11 are bonded not by using an adhesive or the like but by entanglement of the fibers. By entanglement of these fibers and joining, the transfer of a body fluid such as an adhesive between the non-heat-fusion layer 10 and the heat-fusion layer 11 is inhibited as compared with the case of bonding with an adhesive or the like. Since there is no intervening member, the bodily fluid easily moves from the non-heat-fusion layer 10 to the heat-fusion layer 11, and the bodily fluid moves from the non-heat-fusion layer 10 to the heat-fusion layer 11 through the fibers entangled with each other. It will be easier. In addition, since bonding by entanglement of fibers does not increase bonding strength so much, there is an advantage that when the heat-bonding layer 11 is heated and pressed, the influence of heating and pressing on the non-heat-bonding layer 10 can be reduced. . Examples of such a joining method by entanglement of fibers include a water entanglement method in which fibers are entangled by injecting a high-pressure water flow, and a stab method in which fibers are mechanically entangled by stabbing a needle.

  By the way, as shown in FIG. 5, at least the non-heat-sealing layer 10 of the topsheet 3 has a large number of openings 12 penetrating the front and back at least in a region corresponding to the bodily fluid discharge part H in order to enhance liquid permeability. , 12... Are preferably provided. Specifically, the opening 12 can be formed by carrying a fiber material on a mesh-like support in a hydroentanglement step at the time of manufacturing a spunlace. In this case, by changing the conditions of the mesh to be used, it is possible to adjust the size of each opening and the opening ratio. Of course, an opening may be formed by performing a punching (punching) process on the manufactured nonwoven fabric. The opening 12 may be provided in the entire topsheet, but is preferably provided at least in a region corresponding to the body fluid discharging portion H. Preferably, it includes a region corresponding to the body fluid discharge portion H, and corresponds to 15% or more of the absorber length in the product length direction, 50% or more of the absorber width in the product width direction, and more preferably corresponds to the body fluid discharge portion H. The region is provided in an area of 50% or more of the absorber length in the product length direction and 70% or more of the absorber width in the product width direction. If the area where the opening 12 is formed is less than 15% of the absorber length in the product length direction and less than 50% of the absorber width in the product width direction, a situation where the body fluid discharge range cannot be covered may occur. This causes the body fluid to remain on the topsheet 3 and the sticky feeling to be felt, and skin troubles such as itchiness and rash are likely to occur at the time of wearing. The opening 12 may be provided only in the non-heat-fusion layer 10, or may be provided in both the non-heat-fusion layer 10 and the heat-fusion layer 11.

  As shown in FIG. 5, the opening 12 is formed in a vertically long shape that is long in the longitudinal direction of the sanitary napkin 1. For this reason, the liquid permeates more easily than the circular opening, so that the bodily fluid easily passes through the topsheet 3 through the opening 12 and the water retention in the topsheet 3 is reduced. Further, when the bodily fluid passes through the opening 12, the fluid passes while deforming vertically, so that the diffusion direction of the bodily fluid can be controlled in the longitudinal direction of the napkin, the diffusion in the lateral direction is suppressed, and the lateral leakage becomes difficult. In the case of a spun lace, the shape of the opening is difficult to be uniform, but the shape of the opening 12 is generally rectangular to an elongated hole having a corner or an elliptical shape.

As the size of the opening 12, the length L1 of the sanitary napkin 1 in the longitudinal direction is preferably 1.0 to 4.0 mm, preferably 1.5 to 3.0 mm. The length L2 in the width direction is 0.5 to 1.5 mm, preferably 0.5 to 1.0 mm. When the size of the opening 12 is less than 0.5 mm, the body fluid does not easily pass therethrough, and a clear opening is difficult to be formed due to the fluffing of the fiber. When the maximum size of the opening 12 exceeds 4.0 mm, the liquid from the opening 12 And the surface of the material constituting the absorber 4 is exposed. The ratio (L1 / L2) between L1 and L2 is 1.2 to 5.0, preferably 2.0 to 3.0. The area A of the opening 12 is 0.9 to 3.0 mm ² , preferably 0.9 to ^2.5 mm ² . Further, the porosity is 15 to 45%, preferably 17 to 30%, and more preferably 18 to 25%. The size of the opening 12 does not need to be uniform throughout, and can be formed in any size within the above range.

  As shown in FIG. 5, at least the non-heat-sealing layer 10 of the topsheet 3 is formed by the cotton fibers along the length of the sanitary napkin 1 and formed at intervals in the width direction. , And a number of horizontal streaks 14, 14 extending along the width direction of the sanitary napkin 1 and connecting the adjacent vertical streaks 13, 13 formed at intervals in the longitudinal direction. It is preferable that the opening 12 is formed in a portion surrounded by the vertical stripes 13 and the horizontal stripes 14.

  The width W1 of the vertical stripe 13 is preferably 0.5 to 2.5 mm, preferably 0.8 to 2.3 mm, and the width W2 of the horizontal stripe 14 is 0.2 to 1.6 mm, preferably It is good to be 0.3-1.4 mm. Further, the ratio (W1 / W2) of the widths W1 and W2 is 1.2 to 2.0, preferably 1.5 to 2.0. By making the width W1 of the vertical stripes 13 larger than the width W2 of the horizontal stripes 14, liquid diffusion in the longitudinal direction of the sanitary napkin 1 along the vertical stripes 13 is likely to occur.

  The vertical stripes 13 have a larger fiber amount and a higher density than the horizontal stripes 14. As a result, only the vertical streaks 13 come into contact with the skin, and a reduction in the area of contact with the skin makes it less likely to cause skin troubles such as itchiness and rash even when worn for a long time, and at the same time, eliminates The sticky feeling is reduced even after the liquid is applied. Further, when the bodily fluid passes through the topsheet 3, diffusion of the sanitary napkin 1 in the longitudinal direction along the relatively high-density longitudinal streaks 13 easily occurs due to the capillary action of the fibers. Furthermore, since the diffusion direction of the body fluid passing through the opening 12 and the body fluid permeating the topsheet 3 coincide in the longitudinal direction of the sanitary napkin 1, the topsheet is drawn into the body fluid passing through the opening 13. 3 penetrates the vertical streaks 13, so that the liquid residue on the topsheet 3 is minimized.

The measurement of the fiber amount can be performed in accordance with JIS P8207: 2009 “Pulp-sieving test method”. In addition, the measurement of the density is performed by automatically measuring the thickness T ₀ (load: 0.5 gf / cm ² ) using an automatic thickness measuring device (a handy compression tester manufactured by Kato Tech Co., Ltd., KES-G5). It can be calculated from T ₀ .

  It is preferable that a water repellent is externally applied to at least a region corresponding to the bodily fluid discharge portion H on at least the non-heat-fusion layer 10 of the topsheet 3. As the water repellent, paraffin-based and silicone-based known ones can be appropriately selected and used, which are less irritating to the skin.Glyceryl stearate, stearamide, zinc stearate, It is more preferable to appropriately select and use less irritating fats and oils such as calcium stearate, diethanolamide stearate, and magnesium stearate. Among them, glyceryl stearate is particularly preferred. When a water repellent comprising glyceryl stearate is used in the sanitary napkin 1, the amount of the water repellent is preferably 0.05 to 1.50 parts by weight with respect to 100 parts by weight of the fiber (in the case of double-sided application, Total amount of coating on both sides). A more preferred coating amount is 0.03 to 1.50 parts by weight. If the amount of the water-repellent agent is less than 0.05 part by weight, the water-repellent effect may be insufficient, and if it is more than 1.50 parts by weight, the water-repellency is too high, so that it becomes difficult to transmit moisture.

  The water repellent may be applied only to the skin contact surface or to both the skin contact surface and the surface on the absorber 4 side. Is preferably 0.03 g or less, more preferably 0.02 g or less.

  The water absorption of the topsheet 3 is determined by the following procedure. (1) A 10 cm square sample is prepared and its weight is measured (A). (2) Three pieces of 10 cm square filter paper are stacked with the smooth surface side up, and the sample is set thereon. (3) 3 ml of room temperature tap water is dropped on the set sample and left for 5 minutes. (4) The weight of the sample after standing for 5 minutes is measured (B). (5) The water absorption (water retention) of the topsheet 3 is determined from (B)-(A) = water absorption (g).

  As a method of applying the water repellent, known methods such as transfer, spraying, brushing, impregnation, and dipping can be appropriately used. When a difference is made in the water absorption between both surfaces of the sheet, a coating method by transfer can be preferably used.

  The water repellent is preferably applied to the entire surface from the viewpoint of manufacturing efficiency, but it is sufficient that the water repellent is applied to at least a region corresponding to the bodily fluid discharge portion H, or may be applied only to a portion that receives excreted liquid.

<Second seat>
The second sheet 6 is provided between the top sheet 3 and the absorber 4 and adjacent to the non-skin side of the top sheet 3. That is, the non-skin side surface of the heat sealing layer 11 constituting the non-skin side layer of the topsheet 3 and the skin side surface of the second sheet 6 are disposed facing each other. It is preferable that the second sheet 6 has a plane shape substantially the same as that of the top sheet 3. The second sheet 6 is joined to the heat-sealing layer 11 of the liquid-permeable surface sheet 3 by heat-sealing in the pressing unit 15 as described later.

  As the second sheet 6, a perforated or non-porous nonwoven fabric is used as in the case of the heat sealing layer 11 of the top sheet 3. As a fiber material of the nonwoven fabric, synthetic fibers are contained. For example, in addition to thermoplastic synthetic fibers such as olefins such as polyethylene or polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra and natural fibers such as cotton can be included in these synthetic fibers. As the nonwoven fabric, a nonwoven fabric obtained by an appropriate processing method such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, and a needle punch method can be used.

  The second sheet 6 preferably does not contain non-heat-fusible fibers, specifically, the above-mentioned cellulosic fibers, and preferably comprises only heat-fusible fibers, specifically, synthetic fibers. As will be described in detail later, since the second sheet 6 is heat-sealed with the heat-sealing layer 11 of the upper surface sheet 3 in the pressing unit 15, the second sheet 6 contains non-heat-fusible fibers. Therefore, heat fusion is hardly performed in the squeezed portion 15, and the bonding strength between the second sheet 6 and the heat fusion layer 11 may be reduced. The heat fusible fibers of the second sheet 6 and the heat fusible fibers of the heat fusible layer 11 are preferably fiber materials having substantially the same melting point, and both fiber materials are the same. Is particularly preferred.

It is preferable that the second sheet 6 be formed with a lower basis weight and a lower density than the heat sealing layer 11. Thereby, when the pressing unit 15 described in detail later is applied, the second sheet 6 is easily bonded to the heat-sealing layer 11, and a part of the fibers of the heat-sealing layer 11 is formed between the fibers of the second sheet 6. Into the second sheet 6 from the heat-sealing layer 11. The basis weight of the second sheet 6 is 13 to 35 g / m ² , preferably 13 to 18 g / m ² .

  For the second sheet 6, it is preferable to use a material fiber having hydrophilicity to a body fluid. Specifically, synthetic fibers that have been subjected to surface treatment with a hydrophilic agent to impart hydrophilicity can be used. It is preferable that the second sheet 6 has higher hydrophilicity than the heat sealing layer 11 of the top sheet 3.

<Squeezing part>
As shown in FIG. 4, on the non-skin side surface of the second sheet 6, a large number of squeezed portions 15, 15,... Formed by integrally recessing the second sheet 6 and the top sheet 3 toward the skin side are formed. ing. In the state where the second sheet 6 is laminated on the non-skin side of the top sheet 3 (the outer surface side of the heat sealing layer 11), the squeezing unit 15 compresses the second sheet 6 from the non-skin side while simultaneously applying heat or ultrasonic waves. This is a depression formed by melting and solidifying the heat-fusible fibers of the heat-sealable layer 11 and the second sheet 6 by keeping the compressed state. In the compressed portion 15, the heat-sealing layer 11 and the second sheet 6 are firmly fixed, and the top sheet 3 and the second sheet 6 are integrated. The laminate of the top sheet 3 and the second sheet 6 has a flat skin side surface, and a large number of depressions corresponding to the pressing portions 15... On the non-skin side surface.

  As described above, since the top sheet 3 and the second sheet 6 are firmly fixed by the squeezing section 15, the top sheet 3 and the second sheet 6 are closely adhered to each other without gaps, and liquid pools and the like are generated between these layers. Without this, the bodily fluid is easily transferred from the top sheet 3 to the second sheet 6.

  In addition, since the pressing portion 15 is formed by pressing the second sheet 6 from the non-skin side, the non-heat-fused layer 10 on the skin side is not subjected to unevenness processing at a high temperature, and is not processed at a high temperature. In addition to preventing fiber entanglement by squeezing and preventing breakage of the nonwoven fabric due to the squeezing, the smoothness of the surface can be maintained, and deterioration of the touch and reduction in strength can be prevented.

  As shown in FIG. 1, it is preferable that the squeezing portions 15 are formed in an intermittent pattern arranged in large numbers at intervals. In the illustrated example, the dot-shaped squeezed portions 15 are arranged in a staggered pattern at predetermined intervals. The squeezing portion 15 may be arranged in a regular lattice shape arranged at predetermined intervals along the width direction and the longitudinal direction of the sanitary napkin 1.

  In addition, in the example shown in FIG. 1, the squeezed portion 15 is applied to almost the entire surface sheet 3. However, the squeezed portion 15 is applied only to a required area such as an area corresponding to the bodily fluid discharge section H, and applied to other areas. It may not be necessary. Thereby, in the area corresponding to the body fluid discharge part H, the transfer of the body fluid from the top sheet 3 to the second sheet 6 is smoothly performed, and in the other area, the sheet can be prevented from being hardened by pressing, and the cellulose-based material can be prevented. The soft texture of the fibers can be further felt.

  The size of the squeezing section 15 is 1 to 10 mm, preferably 1 to 3 m. If it is smaller than 1 mm, the bonding strength of the heat-sealable layer 11 and the second sheet 6 at one location of the compressed portion 15 is small, the adhesion between the heat-sealable layer 11 and the second sheet 6 is reduced, and the transfer of body fluids is reduced. It is difficult to perform smoothly. On the other hand, if it is larger than 10 mm, the hardness of the squeezed portion 15 is easily felt, and the feeling of wearing may be deteriorated.

  The shape of the squeezing portion 15 is circular in the illustrated example, but can be formed in any shape such as an ellipse or a polygon.

  As shown in FIG. 1, the interval B between the adjacent squeezed portions 15, 15 is 3 to 15 mm, preferably 5 to 10 mm. When the interval B is smaller than 3 mm, the pressing parts 15 and 15 are too close to each other, which causes the topsheet 3 to be hard. On the other hand, if it is larger than 15 mm, the adhesion between the heat-sealing layer 11 and the second sheet 6 is reduced, and it becomes difficult for the body fluid to be smoothly transferred. The interval B is substantially constant over the entire surface in the example shown in FIG. 1, but may be changed depending on the region. For example, in the region corresponding to the body fluid discharge portion H, the interval B is relatively small in order to increase the adhesion between the heat-sealing layer 11 and the second sheet 6 and to facilitate the transfer of the body fluid, and in other regions, , Can be relatively large to maintain a soft feel. Further, the distance B may be gradually increased toward the outer edge side of the sanitary napkin 1 around a region corresponding to the body fluid discharge portion H.

  The embossing ratio, which is the ratio of the total area of the large number of squeezed portions 15 to the area of the second sheet 6, increases the bonding strength between the second sheet 6 and the heat-sealing layer 11 to facilitate the transfer of bodily fluids. From the viewpoint of preventing the wearing feeling from being deteriorated by the hardness of the squeezing portion 15, the content is set to 1 to 20%, preferably 6 to 15%.

  The squeezing depth of the squeezing portion 15 is, as shown in FIG. 4, up to an intermediate position of the non-heat-sealing layer 10 so that most of the non-heat-sealing layer 10, preferably at least half of the thickness, is not squeezed. It is preferred that Thereby, the skin side of the non-heat-fusion layer 10 can sufficiently maintain a soft texture even in the portion where the compressed portion 15 is applied. In the squeezing unit 15, the predetermined dent shape is maintained by squeezing and solidifying the heat fusible fibers of the bottom heat fusible layer 11 and the second sheet 6 during squeezing. Further, a part of the melted heat-fusible fiber flows between the fibers of the non-heat-fusible layer 10 at the bottom of the squeezed portion 15 and solidifies, so that the heat-fusible layer 11 and the non-heat-fusible layer 10 Can increase the bonding strength.

  By applying the pressing portion 15, the non-heat-sealing layer 10 is partially compressed on the non-skin side, and the fiber density is increased. For this reason, the bodily fluid absorbed by the non-heat-fusion layer 10 is easily drawn into the squeezing portion 15 by the capillary action due to the difference in fiber density, and the bodily fluid drawn into the squeezing portion 15 is subjected to squeezing. Due to the entanglement of the fibers between the layers and the density difference of the fibers, it is easy to transfer to the second sheet 6. Therefore, by applying the squeezing portion 15, there is an advantage that the liquid remaining on the surface of the non-heat-fusion layer 10 is small, the sticky feeling can be reduced, and rash due to stuffiness can be prevented.

<Production method>
Next, a method for manufacturing the sanitary napkin 1 will be described. Here, a method of forming the compressed portion 15 which is a feature of the present invention will be described in detail. The other steps are the same as in a general method of manufacturing a sanitary napkin.

  As a first embodiment, as shown in FIG. 6, a laminate of the top sheet 3 and the second sheet 6 corresponds to a flat roll 20 having a flat surface and not to be heated, and the pressing portions 15... The heat-fusible fibers of the second sheet 6 and the heat-fusible layer 11 are heat-fused by passing through at least a convex roll 21 heated at the time of squeezing, in which a large number of protrusions 22 are formed. At the same time as forming the compressed parts 15.

  Thereby, the skin side of the topsheet 3 is flat and excellent in touch, and the topsheet 3 and the second sheet 6 in which the heat-sealing layer 11 and the second sheet 6 of the topsheet 3 are firmly joined in the pressing unit 15 are provided. Is obtained. In addition, since the flat roll 20 is used as a roll facing the non-heat-fusion layer 10 of the topsheet 3, a partial compressive force from the non-heat-fusion layer 10 side does not act, and the flat roll 20 is Since the squeezing is performed by heating only the convex roll 21 without heating, the entanglement of the fibers of the non-heat-bonded layer 10 is prevented by the heating or squeezing during the squeezing, thereby preventing the nonwoven fabric from being broken. In addition, the smoothness of the surface of the non-heat-sealing layer 10 can be maintained, and the deterioration of the touch and the decrease in strength can be prevented.

  Next, as a second embodiment, as shown in FIG. 7, a surface sheet 3 having a two-layer structure of a non-heat-fusion layer 10 and a heat-fusion layer 11 is flattened by a flat roll 23 having a flat surface. Is formed on the non-skin side surface of the topsheet 3 by passing through at least the convex roll 24 heated at the time of squeezing where a large number of convex portions 25 are formed on the surface. After forming a number of intermediate squeezed portions 15 ′, 15 ′... In which the fusion layer 10 is integrally recessed toward the skin side, the surface is flat and the second flat roll 26 is not heated. By passing between at least the second convex roll 27 heated at the time of squeezing in which a large number of convex portions 28 corresponding to the portions 15 are formed, the second sheet 6 and the heat fusion layer 11 At the same time as bonding the adhesive fibers by heat fusion, A method of forming a serial compression portions 15 and the like.

  In the second embodiment, the bonding strength between the non-heat-sealing layer 10 and the heat-sealing layer 11 is increased by forming the intermediate pressing parts 15 ′ in the topsheet 3 in advance. After that, the pressed portion 15 is formed in a state where the top sheet 3 and the second sheet 6 are laminated. The compressed parts 15 may be applied to the depressions of the intermediate compressed parts 15 ', or may be applied to parts other than the intermediate compressed parts 15'.

  DESCRIPTION OF SYMBOLS 1 ... Sanitary napkin, 2 ... Back sheet, 3 ... Top sheet, 4 ... Absorbent, 5 ... Envelope sheet, 6 ... Second sheet, 7 ... Side nonwoven fabric, 8 ... Thread elastic elastic member, 10 ... Non-thermal fusion Layer, 11: heat sealing layer, 12: opening, 13: vertical streak, 14: horizontal streak, 15: pressed part, 15 ': intermediate pressed part, 20: flat roll, 21: convex roll, 22: convex part, 23 flat roll, 24 convex roll, 25 convex part, 26 second flat roll, 27 second convex roll, 28 convex part

Claims (5)

In an absorbent article in which an absorber is interposed between a top sheet and a back sheet,
Consists of a non-heat sealable layer consisting of cellulosic fibers in which the surface sheet is arranged on the skin side, a thermal adhesive layer comprising a heat-fusible fibers disposed on the non-skin side, the non-heat The bonding layer and the heat-sealing layer are joined with each other by entanglement of the fibers,
On the non-skin side of the top sheet, a second sheet made of heat-fusible fibers is provided, and on the non-skin side surface of the second sheet, the second sheet and the top sheet are squeezed from the non-skin side of the second sheet. A large number of pressed parts are formed integrally and depressed toward the skin side, the heat-sealing layer and the second sheet are fixed to each other in the pressed part, and the laminate of the top sheet and the second sheet is An absorbent article characterized in that the skin side is formed flat . The second sheet, the absorbent article according to claim 1 Symbol placement than the heat sealable layer is formed of a low basis weight and low density. The absorbent article according to any one of claims 1 and 2 , wherein the squeezed portions are formed in an intermittent pattern in which a number of squeezed portions are arranged at intervals. The absorbent article according to any one of claims 1 to 3 , wherein the non-heat-sealing layer is formed of 100% by weight of cotton fibers. The absorbent article according to any one of claims 1 to 4 , wherein the heat-sealing layer does not include a non-heat-sealing fiber.

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