JP6941007B2 - Absorbents and absorbent articles - Google Patents

Description

The present invention relates to an absorber used for an absorbent article such as a urine pad (including a light incontinence pad), a sanitary napkin, and a disposable diaper, and an absorbent article provided with the absorber.

Conventionally, an absorbent article having an absorbent core having an opening is known (for example, Patent Documents 1 and 2). In the absorbent article provided with such an absorbent core, the diffusivity of the body fluid such as urine is enhanced by the opening, and the body fluid can be rapidly absorbed by the absorbent core. On the other hand, Patent Document 3 is an absorbent article in which a water-absorbent resin is arranged in the absorbent core itself and a water-absorbent resin is arranged in the opening of the absorbent core in order to allow the opening of the absorbent core to absorb body fluids. It is disclosed in. The absorbent article of Patent Document 3 has an absorber in which an absorbent core is arranged between the upper core wrap sheet and the lower core wrap sheet, and the upper core wrap sheet and the lower core wrap are provided at the opening of the absorbent core. A water-absorbent resin is sandwiched between the sheets.

Jikkai Sho 63-093921 Japanese Unexamined Patent Publication No. 2013-017531 Japanese Unexamined Patent Publication No. 2012-179230

Since the absorbent body in which the water-absorbent resin is arranged at the opening of the absorbent core can have the absorbency of the body fluid at the opening, the absorption capacity of the absorbent body as a whole can be increased. However, since the water-absorbent resin arranged at the opening of the absorbent core swells by absorbing the body fluid, the diffusibility of the body fluid at the opening tends to be hindered.

The present invention has been made in view of the above circumstances, and an object of the present invention is an absorber in which a water-absorbent resin is arranged at an opening of an absorbent core, which is excellent in diffusivity and absorbability of body fluid. And to provide an absorbent article with the absorber.

The absorber of the present invention that has been able to solve the above problems is an absorber that is used for absorbing body fluid and has a skin surface side and a non-skin surface side; the absorber has an opening. It has an absorbent core and a coating sheet that overlaps the opening and is provided at least on the non-skin surface side of the absorber; the absorbent core contains hydrophilic fibers and a water-absorbent resin; the non-skin surface of the absorbent core On the skin surface side of the coating sheet provided on the side, a water-absorbent resin is arranged at a portion overlapping the opening of the absorbent core; the liquid passing rate under load of the water-absorbent resin arranged on the coating sheet absorbs. It is characterized in that it is faster than the liquid passing speed under load of the water-absorbent resin arranged on the sex core.

In the absorber of the present invention, since the water-absorbent resin is arranged on the coating sheet provided on the non-skin surface side of the absorbent core at the portion overlapping the opening of the absorbent core, the body fluid is also formed at the opening of the absorbent core. It has the absorbency of the above, and the absorption capacity of the entire absorber can be increased. At this time, by using a water-absorbent resin whose liquid passing rate under load is faster than that of the water-absorbent resin arranged in the absorbent core, as the water-absorbent resin arranged in the portion overlapping the opening of the coating sheet, the absorbent core Even when the water-absorbent resin is placed in the opening, the diffusibility of the body fluid in the opening can be ensured. Therefore, the absorber of the present invention has excellent absorption performance.

The flow rate of the water-absorbent resin arranged on the coating sheet under load is preferably 10 seconds or less.

The coating sheet is preferably composed of cellulose fibers, and the water-absorbent resin arranged on the coating sheet is preferably fixed to the coating sheet with an anionic or nonionic fixing agent. By fixing the water-absorbent resin to the coating sheet using such a fixing agent, the water-absorbing resin is fixed to the coating sheet with a certain strength, and the water-absorbing ability of the water-absorbent resin due to the water-absorbing functional group is increased by the fixing agent. It is possible to suitably exhibit the water absorption performance of the water-absorbent resin without being hindered.

A water-absorbent resin may be arranged on the coating sheet in addition to the portion overlapping the opening of the absorbent core. As a result, the absorption capacity of the entire absorber can be increased, and even when body fluid such as urine reaches the non-skin surface side of the absorbent core through the opening of the absorbent core, the opening of the covering sheet and the opening of the covering sheet Body fluids are absorbed by the water-absorbent resin arranged in areas other than the overlapping portion, and leakage of the absorbent article from the non-skin surface side can be prevented.

The coating sheet is preferably bonded to the absorbent core with a hot melt adhesive. As a result, the covering sheet is firmly bonded to the absorbent core, and the integrity between the covering sheet and the absorbent core can be enhanced.

The present invention also comprises the absorber of the present invention, a liquid-permeable top sheet provided on the skin surface side of the absorber, and a liquid-impermeable back sheet provided on the non-skin surface side of the absorber. Also provided are absorbent articles having. Since the absorbent article of the present invention is provided with the absorber of the present invention described above, it has excellent absorption performance in which both absorbability and diffusivity of body fluid are compatible.

The absorbent article is provided with a protective sheet between the absorbent body and the back sheet, and the protective sheet is wider in the width direction than the region where the water-absorbent resin is arranged on the covering sheet and is larger than the absorbent body. It is preferably formed narrow in the width direction. By providing the protective sheet in this way, when the absorbent article is touched from the non-skin surface side, the graininess of the water-absorbent resin arranged on the covering sheet can be suppressed, and the non-skin surface of the absorbent article can be suppressed. It becomes easier to secure the flexibility of the side.

In the absorber of the present invention, since the water-absorbent resin is arranged at the portion overlapping the opening of the absorbent core, the absorbent body has the absorbency of the body fluid even at the opening of the absorbent core, and enhances the absorption capacity of the entire absorber. be able to. At this time, by using a water-absorbent resin whose liquid passing rate under load is faster than that of the water-absorbent resin arranged in the absorbent core, as the water-absorbent resin arranged in the portion overlapping the opening of the coating sheet, the absorbent core Even when the water-absorbent resin is placed in the opening, the diffusibility of the body fluid in the opening can be ensured. Therefore, the absorber of the present invention has excellent absorption performance.

An example of the absorber of the present invention is shown, and a plan view of the absorber as viewed from the non-skin surface side is shown. An example of the AA cross-sectional view (width direction cross-sectional view) of the absorber shown in FIG. 1 is shown. Another example of the cross-sectional view in the width direction of the absorber of the present invention is shown. An example of the absorbent article provided with the absorber shown in FIG. 1 is shown, and a plan view of the absorbent article as viewed from the skin surface side is shown. FIG. 4 shows a cross-sectional view taken along the line BB of the absorbent article shown in FIG.

The absorber of the present invention is used for absorbing body fluids such as urine, and is provided for absorbent articles such as urine pads (including incontinence pads), disposable diapers, and sanitary napkins. The absorber absorbs and fixes body fluids such as urine received by the absorbent article, and is provided, for example, between the top sheet and the back sheet of the absorbent article. Hereinafter, the absorber of the present invention will be specifically described with reference to the drawings, but the present invention is not limited to the embodiments shown in the drawings.

1 and 2 show an example of the absorber of the present invention. FIG. 1 shows a plan view of the absorber as viewed from the non-skin surface side, and FIG. 2 shows an example of the AA cross-sectional view (width direction cross-sectional view) of the absorber shown in FIG. In the drawings, the arrow x represents the width direction, the arrow y represents the longitudinal direction, and the direction perpendicular to the surface formed by the arrows x and y represents the thickness direction z. In the thickness direction z, z1 represents the skin surface side and z2 represents the non-skin surface side.

In the absorber, the longitudinal direction y corresponds to a direction extending in the anteroposterior direction of the wearer's crotch when the wearer wears the absorbent article provided with the absorber. The width direction x means a direction that is on the same plane as the absorber and is orthogonal to the longitudinal direction y. The absorber has a skin surface side and a non-skin surface side with respect to the thickness direction z. The skin surface side means the wearer side when the absorbent article is worn, and corresponds to the top sheet side when the absorbent body is taken as a reference. The non-skin surface side means the side opposite to the wearer when the absorbent article is worn, that is, the outside, and corresponds to the back seat side with the absorbent body as a reference.

The absorber 1 has an absorbent core 2 and a covering sheet 5 provided on at least the non-skin surface side of the absorbent core 2. The covering sheet is composed of a paper sheet (for example, tissue paper or thin paper), a liquid-permeable non-woven fabric, or the like, and is provided to enhance the shape retention of the absorbent core 2.

The covering sheet 5 may be provided on the non-skin surface side of the absorbent core 2 and may be provided on the skin surface side of the absorbent core 2. In the absorber 1 shown in FIGS. 1 and 2, the covering sheet 5 is provided on both the non-skin surface side and the skin surface side of the absorbent core 2. In this case, the covering sheet 5A provided on the non-skin surface side of the absorbent core 2 and the covering sheet 5B provided on the skin surface side may be formed from the same sheet or may be formed from different sheets. .. In the former case, the covering sheet 5 is provided so as to cover the absorbent core 2 from the non-skin surface side to the skin surface side. Specifically, the covering sheet 5 extends over the entire width direction x of the absorbent core 2 on the non-skin surface side of the absorbent core 2 and absorbs along both side edges of the absorbent core 2 in the width direction x. It is preferable that the sex core 2 is folded back toward the skin surface side, and both ends of the covering sheet 5 in the width direction x are provided so as to be located on the skin surface side of the absorbent core 2. It is preferable that the entire skin surface side and non-skin surface side of the absorbent core 2 are covered with the coating sheet 5.

The coating sheet 5 is preferably made of cellulose fibers. Examples of the coating sheet 5 made of cellulose fibers include paper sheets such as tissue paper and thin paper, rayon sheets, acetate sheets, and the like. Among them, it is convenient and preferable to use a paper sheet as the coating sheet 5. The paper sheet can be used without particular limitation as long as it is formed into a sheet by entwining plant fibers with each other. The paper sheet can be produced, for example, by a wet papermaking method.

The thickness of the covering sheet 5 is, for example, preferably 300 μm or less, more preferably 200 μm or less, further preferably 100 μm or less, still more preferably 5 μm or more, still more preferably 10 μm or less, still more preferably 20 μm or more. The thickness of the coating sheet is measured according to JIS P 8118 (2014).

The absorbent core 2 contains hydrophilic fibers and a water-absorbent resin. Examples of hydrophilic fibers include natural fibers such as pulp fibers; regenerated fibers such as rayon fibers; semi-synthetic fibers such as acetate fibers; polyolefin fibers such as polyethylene and polypropylene, polyester fibers such as PET, and polyamide fibers such as nylon. As the fiber, a fiber or the like which has been hydrophilized with a surfactant or the like can be used. As the water-absorbent resin, a water-absorbent resin such as polyacrylic acid-based, polyaspartic acid-based, cellulosic-based, starch / acrylonitrile-based can be used. As the absorbent core 2, it is preferable to use an aggregate of hydrophilic fibers mixed with a water-absorbent resin.

The shape (planar shape) of the absorbent core 2 is not particularly limited. The shape of the absorbent core 2 may be appropriately determined according to the intended use, and examples thereof include a substantially rectangular shape, an hourglass shape, a gourd shape, and a battledore shape. The absorbent core 2 may be formed by laminating a plurality of layers. In the drawing, the absorbent core 2 is formed in an hourglass shape.

The thickness of the absorbent core 2 is, for example, preferably 1 mm or more, more preferably 2 mm or more, preferably 12 mm or less, more preferably 10 mm or less, still more preferably 8 mm or less. The thickness of the absorbent core described here means the thickness of the thickest portion of the absorbent core. The thickness of the absorbent core can be measured with a thickness gauge, for example, using a thickness gauge SM-130 manufactured by Teclock Co., Ltd. For example, the thickness is measured by sandwiching the absorbent core between the anvil and the stylus, and at that time, the thickness gauge SM-130 measures the thickness so that the final pressure is 2.2 N or less. The anvil and the stylus have a circular contact surface with a diameter of 10 mm and a flat contact surface.

The absorbent core 2 has an opening 4. By providing the opening 4 in the absorbent core 2, the diffusibility of the body fluid is enhanced in the portion where the opening 4 is provided, and the absorbent core 2 can contribute to the absorption of the body fluid in a wider range. The opening 4 is preferably formed so as to extend in the longitudinal direction y of the absorber 1, whereby the diffusibility of the absorber 1 in the longitudinal direction y is enhanced, and the entire absorbent core 2 is absorbed by the body fluid. You will be able to contribute effectively. The opening extending in the longitudinal direction y means an opening having a shape longer in the longitudinal direction y than in the width direction x. The opening 4 is provided so as to penetrate the absorbent core 2 in the thickness direction.

The absorbent core 2 may be provided with only one opening 4 or two or more openings, but the number of openings 4 provided in the absorbent core 2 is preferably 3 or less, preferably 2 or less. More preferably, only one is even more preferred. In the absorber 1 shown in the drawing, only one opening 4 is provided in the absorbent core 2. When the absorbent core 2 is provided with only one opening, it is preferable that the opening is provided at the center of the absorbent core 2 in the width direction x so as to extend in the longitudinal direction y. When the absorbent core 2 is provided with two openings, the openings are not provided in the central portion of the absorbent core 2 in the width direction x, but on one side sandwiching the central portion of the absorbent core 2 in the width direction x. It is preferable that the other side is provided so as to extend in the longitudinal direction y, respectively. When the absorbent core 2 is provided with three openings, it is preferable that the openings are provided so as to extend in the longitudinal direction y at the central portion of the absorbent core 2 in the width direction x and on both sides thereof. The central portion of the absorbent core 2 in the width direction x includes a portion including the center line of the absorbent core 2 in the width direction x and extending in the longitudinal direction y along the center line.

The length of the opening 4 in the width direction x is preferably 5% or more, more preferably 8% or more, and 10% or more of the length of the width direction x in the narrowest portion of the absorbent core 2. More preferably, 30% or less is preferable, 25% or less is more preferable, and 20% or less is further preferable. When two or more openings are provided, it is preferable that the total width direction x length of the openings in the narrowest portion of the absorbent core 2 is in such a ratio. The narrowest portion of the absorbent core 2 means the narrowest portion of the absorbent core 2 excluding both ends in the longitudinal direction y. For example, the absorbent core 2 is set to y in the longitudinal direction. When divided into five equal parts, it means the portion formed narrowest in the width direction x except for the portion of 1/5 on one side and 1/5 of the other side in the longitudinal direction y.

The width of the opening 4 is also preferably 5 mm or more, more preferably 8 mm or more, preferably 35 mm or less, and more preferably 25 mm or less. When two or more openings are provided, the width of each opening is preferably in such a range.

The length of the opening 4 in the longitudinal direction y is preferably 40% or more, more preferably 50% or more, further preferably 60% or more, and 90% or more of the length in the longitudinal direction y of the absorbent core 2. The following is preferable, 85% or less is more preferable, and 80% or less is further preferable. The opening 4 is preferably provided so as not to come into contact with the outer edge of the absorbent core 2.

When the absorbent core 2 is formed in an hourglass shape, the opening 4 is preferably provided at least in an hourglass-shaped constriction. That is, the absorbent core 2 has one end, the other end, and an intermediate portion between them in the longitudinal direction y, and one end and the other end of the absorbent core 2 are formed wider than the intermediate portion. , It is preferable that the opening 4 is provided at least in the middle portion. The opening 4 may further extend to one end and / or the other end.

A coating sheet 5A is provided on the non-skin surface side of the absorbent core 2, and a water-absorbent resin 6 is arranged on the skin surface side of the coating sheet 5A at a portion overlapping the opening 4 of the absorbent core 2. By arranging the water-absorbent resin 6 in the portion overlapping the opening 4 of the absorbent core 2 in this way, the absorber 1 becomes able to absorb the body fluid even in the opening 4 of the absorbent core 2, and the absorbent body 1 is absorbed. The overall absorption capacity can be increased.

By the way, as described above, by providing the opening 4 in the absorbent core 2, the absorber 1 can enhance the diffusivity of body fluid such as urine in the opening 4, but the opening 4 of the absorbent core 2 When the water-absorbent resin 6 is arranged, the water-absorbent resin 6 swells by absorbing body fluid such as urine, so that the diffusibility of the body fluid such as urine at the opening 4 tends to be hindered. Therefore, the absorber 1 of the present invention is arranged at a portion overlapping the opening 4 of the covering sheet 5A in order to ensure the diffusivity of the body fluid in the opening 4 while allowing the opening 4 of the absorbent core 2 to have absorbency. As the water-absorbent resin 6, a water-absorbent resin having a liquid-passing speed under load is used, which is faster than the liquid-passing speed under load of the water-absorbent resin 3 arranged in the absorbent core 2. By using such a water-absorbent resin, the diffusibility of the body fluid can be ensured even when the water-absorbent resin 6 is arranged in the opening 4 of the absorbent core 2.

By appropriately setting the water-absorbent resin to be arranged in the absorber 1 as described above, the absorber 1 diffuses the body fluid at its opening 4 rather than the absorbent core 2 itself (aggregate portion of hydrophilic fibers). Increases sex. The specific value of the underload liquid passing rate of the water-absorbent resin 6 arranged in the opening 4 of the absorbent core 2, that is, the water-absorbent resin 6 arranged in the coating sheet 5A is preferably 10 seconds or less, preferably 8 seconds. The following is more preferable, and 6 seconds or less is further preferable. The lower limit of the liquid passing speed under load of the water-absorbent resin 6 is not particularly limited, but may be, for example, 1 second or longer, 2 seconds or longer, or 3 seconds or longer.

The flow rate of the water-absorbent resin under load is measured according to the following method. In a glass beaker with a capacity of 100 mL, 0.32 ± 0.005 g of water-absorbent resin powder is immersed in 100 mL of physiological saline (0.9 mass% sodium chloride solution) and left for 60 minutes. Separately, at the lower end of the opening of a vertically erected cylinder (inner diameter 25.4 mm), a wire mesh (opening 150 μm, biocolumn sintered stainless steel filter 30SUS manufactured by Sansho Co., Ltd.) and a thin tube with a cock (inner diameter 2 mm) (inner diameter 2 mm) A filtration cylindrical tube having an inner diameter of 4 mm and a length of 8 cm) is prepared, and all the contents of the beaker including the swollen measurement sample are put into the cylindrical tube with the cock closed. Next, a cylindrical rod having a diameter of 2 mm and having a wire mesh having a mesh size of 150 μm and a diameter of 25 mm at the tip is inserted into the filtration cylindrical tube so that the wire mesh and the measurement sample are in contact with each other, and the measurement sample is further charged with 2.0 kPa. Place the weight so that the load is applied. After leaving it in this state for 1 minute, the cock is opened to allow the liquid to flow, and the time from the 60 mL scale line to the 40 mL scale line (that is, 20 mL liquid passes through) T ₁ ( Seconds) is measured. Using the measured time T ₁ (seconds), the formula: Under-load liquid flow rate (seconds) = T ₁ −T ₀ to calculate the under-load liquid flow rate at 2.0 kPa. In the formula, T ₀ (seconds) is a value obtained by measuring the time required for 20 mL of physiological saline to pass through the wire mesh without placing the measurement sample in the filtration cylindrical tube. The measurement is performed at a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5%, and the water-absorbent resin is held in the same environment for 24 hours or more before the measurement.

It is also preferable that the water-absorbent resin 6 arranged in the portion overlapping the opening 4 of the coating sheet 5A has a slower water absorption rate by the vortex method than the water-absorbent resin 3 arranged in the absorbent core 2. By appropriately setting the water-absorbent resin to be arranged in the absorber 1 in this way, even in the initial stage of absorption, the diffusivity of the body fluid at the opening 4 of the absorbent core 2 itself (aggregate portion of hydrophilic fibers) is higher than that of the absorbent core 2 itself (aggregate portion of hydrophilic fibers). Will increase.

The water absorption rate of the water-absorbent resin by the vortex method is measured according to JIS K 7224 (1996). Specifically, the water absorption rate is calculated as follows. A glass beaker with a capacity of 100 mL is coated with 50 mL of physiological saline (0.9 mass% sodium chloride solution) and a magnetic stirrer chip (center diameter 8 mm, both ends diameter 7 mm, length 30 mm, and the surface is coated with fluororesin. Put the thing) and put the beaker on the magnetic stirrer (HPS-100 manufactured by AS ONE Co., Ltd.). Adjust the rotation speed of the magnetic stirrer to 600 ± 60 rpm and stir the saline solution. 2.0 g of the water-absorbent resin was poured into the liquid at the center of the whirlpool of the salt solution being stirred, and when the water-absorbent resin was completely charged into the beaker, the timekeeping was started and the stirrer chip was covered with the test liquid. Stop the timekeeping at the time when the stirrer disappears (when the vortex disappears and the liquid surface becomes flat), and record the time (seconds) as the water absorption rate. The measurement is performed 5 times (n = 5), the values at each of the upper and lower points are deleted, and the average value of the remaining 3 points is used as the measured value. The measurement is performed at a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5%, and the water-absorbent resin is held in the same environment for 24 hours or more before the measurement.

In covering sheet 5A, the amount of the water absorbing resin 6 to be disposed in a portion that overlaps with the opening 4 of the absorbent core 2 is, for example, 5 g / m ² or more, more preferably 15 g / m ² or more, 30 g / m ² The above is more preferable, 300 g / m ² or less is preferable, 200 g / m ² or less is more preferable, and 150 g / m ² or less is further preferable. By arranging the water-absorbent resin 6 in the opening 4 of the absorbent core 2 in such an amount, the absorbability of body fluid such as urine can be improved in the opening 4 of the absorbent core 2, and the absorbent core 2 can be improved. It becomes easy to secure the diffusivity of body fluids such as urine in the opening 4 of.

The water-absorbent resin 6 is preferably fixed to the coating sheet 5A so as not to move freely with respect to the coating sheet 5A. The water-absorbent resin 6 can be fixed to the coating sheet 5A by a known adhesive means such as a hot melt adhesive, but the water-absorbent resin 6 is fixed to the coating sheet 5A to absorb body liquid and swell the water-absorbent resin. Is not inhibited, and from such a viewpoint, the water-absorbent resin 6 is preferably fixed to the coating sheet 5A with an anionic or nonionic fixing agent. For example, when a cationic fixing agent is used, the fixing agent binds to a water-absorbing functional group (a functional group having a binding or fixing action with water molecules) contained in the water-absorbent resin, and the water-absorbing resin absorbs water. Where the performance may deteriorate, by using an anionic or nonionic fixing agent, the fixing agent does not strongly bond to the water-absorbing functional group contained in the water-absorbent resin, and the water-absorbing performance of the water-absorbent resin is preferable. It will be easier to demonstrate. On the other hand, when an anionic or nonionic fixing agent is used, the coating sheet 5A is preferably composed of cellulose fibers from the viewpoint of firmly adhering the fixing agent to the coating sheet 5A. By using the coating sheet 5A composed of cellulose fibers, the water-absorbent resin 6 can be firmly fixed to the coating sheet 5A even when an anionic or nonionic fixing agent is used.

As the anionic fixing agent, it is preferable to use an anionic polymer. As the anionic polymer, a polymer containing a repeating unit having an acid group can be used, and examples of the acid group include a carboxylic acid group (carboxy group), a sulfonic acid group (sulfo group), and a phosphoric acid group. .. These acid groups may be partially neutralized by any cation. Among them, as the anionic polymer, it is preferable to use a polymer containing a repeating unit having a carboxylic acid group. As anionic fixing agents, carboxymethyl cellulose (salt), poly (meth) acrylic acid (salt), (meth) acrylic acid ester- (meth) acrylic acid (salt) copolymer, (meth) acrylamide- (meth) ) Acrylic acid (salt) copolymer, maleic acid- (meth) acrylic acid (salt) copolymer, polyamino acid (salt) containing a constituent unit derived from aspartic acid (salt) and / or glutamate (salt), etc. Can be mentioned. The polyacrylic acid (salt) used as an anionic fixing agent basically has a non-crosslinked structure and is non-swellable, unlike the polyacrylic acid used as a water-absorbent resin.

As the nonionic fixing agent, it is preferable to use a nonionic polymer, and the nonionic polymer preferably has a high affinity for water. Preferred examples of the nonionic fixing agent include polyvinyl alcohol, polyethylene glycol, polyacrylamide, starch, gum, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, polyvinylpyrrolidone and the like.

As the anionic or nonionic fixing agent, only one kind may be used, or two or more kinds may be used in combination. Further, an anionic fixing agent and a nonionic fixing agent may be used in combination.

The amount of anionic or nonionic fixing agent applied, specifically, the amount of anionic or nonionic fixing agent applied to the portion of the coating sheet 5A that overlaps the opening 4 of the absorbent core 2 is determined. For example, 0.1 part by mass or more is preferable, 0.5 part by mass or more is more preferable, and 1 part by mass or more is further preferable, and 30 parts by mass or more is preferable with respect to 100 parts by mass of the water-absorbing resin arranged in the portion overlapping with the opening 4. It is preferably parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less.

The coating sheet 5A may be provided with a water-absorbent resin in addition to the portion overlapping the opening 4 of the absorbent core 2. For example, as shown in FIG. 1, a water-absorbent resin 6 is provided on the skin surface side of the coating sheet 5A at a portion overlapping the opening 4 of the absorbent core 2, and extends in the longitudinal direction y from the portion overlapping the opening 4. The water-absorbent resin 6 may also be provided at a portion that does not overlap with the opening 4. FIG. 3 shows a modified example of the width direction x cross-sectional view of the absorbent body 1, but in FIG. 3, both sides of the width direction x of the portion overlapping the opening 4 of the absorbent core 2 on the skin surface side of the covering sheet 5A. Also, a water-absorbent resin 6 is arranged. In FIG. 3, the water-absorbent resin 6 is arranged in a stripe shape extending in the longitudinal direction y. By arranging the water-absorbent resin 6 in this way, the absorption capacity of the entire absorber can be increased, and body fluids such as urine pass through the opening 4 of the absorbent core 2 and pass through the opening 4 of the absorbent core 2 on the non-skin surface side of the absorbent core 2. Even in such a case, the body fluid is absorbed by the water-absorbent resin 6 arranged in a portion other than the portion overlapping the opening 4 of the covering sheet 5A, and leakage of the absorbent article from the non-skin surface side can be prevented. ..

Even when the water-absorbent resin 6 is arranged on the coating sheet 5A in a portion other than the portion overlapping the opening 4, the water-absorbent resin 6 may be fixed to the coating sheet 5 by the anionic or nonionic fixing agent described above. can. Further, the water-absorbent resin 6 is preferably arranged in a stripe shape extending in the longitudinal direction y of the covering sheet 5A on the skin surface side of the covering sheet 5A, including the portion arranged in the portion overlapping the opening 4. By arranging the water-absorbent resin 6 in this way, body fluids such as urine are less likely to spread to the non-skin surface side of the absorbent core 2 through the opening 4 of the absorbent core 2, and the water-absorbent resin 6 is coated on the coating sheet. Compared with the case where it is arranged on the whole of 5, it is possible to reduce the feeling of stiffness on the non-skin surface side of the absorber 1 and the feeling of roughness derived from the water-absorbent resin 6. In this case, from the viewpoint of preventing leakage of body fluid, the water-absorbent resin 6 is preferably arranged in a stripe shape having a length of 80% or more of the length y in the longitudinal direction of the coating sheet 5, and is preferably 90% or more. It is more preferable to arrange them in a striped shape having a length.

When the opening 4 is provided at the center of the absorbent core 2 in the width direction x so as to extend in the longitudinal direction y, the water-absorbent resin 6 is at the center of the absorbent core 2 in the width direction x, as shown in FIG. It is preferable that the portion including the portion is arranged in a stripe shape which is wider than the other portion. As a result, body fluids such as urine are less likely to migrate to the non-skin surface side of the absorbent core 2 through the opening 4 of the absorbent core 2.

As shown in FIGS. 2 and 3, when the covering sheet 5B is also provided on the skin surface side of the absorbent core 2 so as to overlap the opening 4, the covering sheet 5A provided on the non-skin surface side of the absorbent core 2 is provided. And the covering sheet 5B provided on the skin surface side are preferably adhered to each other at the opening 4. As a result, the covering sheet 5 can stably sandwich the absorbent core 2, and the shape retention of the absorbent body 1 can be improved.

The coating sheet 5 is preferably adhered to the absorbent core 2 with a hot melt adhesive. Specifically, it is preferable that the coating sheet 5 is adhered to an aggregate of hydrophilic fibers constituting the absorbent core 2 with a hot melt adhesive. As a result, the covering sheet 5 is firmly bonded to the absorbent core 2, and the integrity of the covering sheet 5 and the absorbent core 2 is enhanced.

Examples of the hot melt adhesive include rubber-based adhesives such as natural rubber-based, butyl rubber-based, and polyisoprene; styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS). , Styrene-based elastomers such as styrene-ethylene-butadiene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS); ethylene-vinyl acetate copolymer (EVA); polyester; acrylic elastomer ; A polyolefin-based elastomer or the like can be used. Only one kind of these hot melt adhesives may be used, or two or more kinds thereof may be used in combination.

The hot melt adhesive is preferably applied in an intermittent pattern such as reticulated, linear or scattered, whereby the absorption of body fluids such as urine by the absorbent core 2 is inhibited by the hot melt adhesive layer. It becomes difficult. For example, when the adhesive is applied in a linear adhesive pattern, the linear adhesive pattern may be linear or curved (eg, meandering, omega, spiral). Often, these may be a combination.

Next, the absorbent article of the present invention will be described. The absorbent article of the present invention is characterized in that the absorbent body of the present invention is provided, and the absorbent body of the present invention is arranged between the top sheet and the back sheet. Examples of the absorbent article include a urine pad (including an incontinence pad), a disposable diaper, a sanitary napkin, and the like. The absorbent article of the present invention is provided with the absorber described above, so that it has excellent absorption performance in which both absorbability and diffusivity of body fluid such as urine are compatible.

The shape of the absorbent article is not particularly limited. When the absorbent article is, for example, a urine pad or a sanitary napkin, the shape of the absorbent article may be rectangular, hourglass-shaped, gourd-shaped, battledore-shaped or the like.

When the absorbent article is a disposable diaper, the disposable diaper may be a tape-type disposable diaper in which fastening members are provided on both the left and right sides and the fastening members form a pants shape when worn, and the waist opening. It may be a pants-type disposable diaper in which a pair of diapers and a pair of leg openings are formed. In a pants-type disposable diaper, even if the absorbent body of the present invention is arranged between the top sheet and the back seat, the absorbent body is attached to the skin side of the exterior member formed in the shape of pants. good.

The top sheet is provided on the skin surface side of the absorber and is liquid permeable. The top sheet is provided so as to face the wearer's skin when wearing the absorbent article. Examples of the top sheet include non-woven fabrics formed from hydrophilic fibers such as cellulose, rayon and cotton; and hydrophobicity such as polyolefins (eg polypropylene, polyethylene), polyesters (eg PET) and polyamides (eg nylon). A non-woven fabric formed from fibers, in which the surface of the hydrophobic fibers is hydrophilized by a surfactant, or the like can be used. Further, as the top sheet, a woven fabric, a knitted fabric, or a plastic film having holes may be used.

The back sheet is provided on the non-skin surface side of the absorber and is impermeable to liquid. The backseat is provided so as to face the side opposite to the wearer, that is, the outside when the absorbent article is worn. As the back sheet, a non-woven fabric formed of hydrophobic fibers such as polyolefin (for example, polypropylene, polyethylene), polyester (for example, PET), and polyamide (for example, nylon), a plastic film, or the like can be used. Further, a laminate of a non-woven fabric and a plastic film may be used.

When the top sheet or back sheet is composed of a non-woven fabric, it is preferable to use a spunbonded non-woven fabric, an air-through non-woven fabric, a point-bonded non-woven fabric, a melt-blown non-woven fabric, an air-laid non-woven fabric, an SMS non-woven fabric, or the like.

It is preferable that the absorbent article is provided with a protective sheet between the absorber and the back sheet. As the protective sheet, a sheet material that can be used for a top sheet or a back sheet can be used, and it is preferable that the protective sheet is composed of a non-woven fabric, a woven fabric, a knitted fabric, or the like. Since the absorbent core has a water-absorbent resin arranged on the coating sheet on the non-skin surface side of the absorbent core, the presence of the water-absorbent resin makes it easy for minute irregularities to be formed on the surface of the absorbent body on the non-skin surface side. Therefore, when the absorbent article is touched from the non-skin surface side, a feeling of roughness is felt due to the minute unevenness of the water-absorbent resin, or when the back sheet is made of a plastic film, the back sheet is directly backed to the absorbent body. When the sheets come into contact with each other, the back sheet may be easily damaged by the minute irregularities of the water-absorbent resin. However, by providing the protective sheet between the absorbent body and the back sheet, it is possible to suppress the feeling of roughness on the non-skin surface side of the absorbent article and to prevent the back sheet from being damaged. Preferably, the protective sheet is formed wider in the width direction than the region where the water-absorbent resin of the coating sheet is arranged.

On the other hand, the protective sheet is preferably formed narrower in the width direction than the absorber. As a result, it is possible to prevent the protective sheet and the back sheet from reducing the flexibility of the absorbent article on the non-skin surface side without forming the entire non-skin surface side of the absorbent article thickly. The protective sheet is more preferably formed narrower in the width direction than the absorbent core.

It is preferable that the absorbent article is provided with rising flaps on both sides in the width direction on the skin surface side. By providing the rising flap, lateral leakage of body fluid such as urine is prevented. For the rising flap, for example, side sheets extending in the longitudinal direction are joined to both sides in the width direction of the top sheet, and elastic members are provided inward in the width direction of the side sheet (near the upper end when the rising flap rises). Is formed by. By providing the side sheet and the elastic member in this way, the inner side of the side sheet in the width direction rises toward the wearer's skin due to the contraction force of the elastic member, and a rising flap is formed. The rising flap or side sheet is preferably made of a liquid-impermeable plastic film, a liquid-impermeable non-woven fabric, or the like.

The absorbent article of the present invention will be described with reference to FIGS. 4 and 5 by taking a tape-type disposable diaper as an example. The absorbent article of the present invention is not limited to the embodiments shown in the drawings. 4 and 5 show an absorbent article with the absorbers shown in FIGS. 1 and 2. FIG. 4 shows a plan view of a tape-type disposable diaper as an absorbent article as viewed from the skin surface side, and FIG. 5 shows a cross-sectional view taken along the line BB of the absorbent article shown in FIG.

The absorbent article 11 has a top sheet 12, a back sheet 13, and an absorber 1 provided between them. The top sheet 12 is arranged so as to face the wearer's skin and allows body fluids such as urine to permeate. The body fluid that has passed through the top sheet 12 is housed in the absorber 1. The backsheet 13 is liquid impermeable and prevents body fluids from leaking to the outside.

A protective sheet 14 is provided between the absorber 1 and the back sheet 13 so as to overlap the opening 4 of the absorbent core 2. By providing the protective sheet 14, when the absorbent article 11 is touched from the back sheet 13 side, the graininess of the water-absorbent resin 6 arranged in the opening 4 of the absorbent core 2 can be reduced. Further, it is possible to prevent the back sheet 13 from being damaged by the protective sheet 14 when minute irregularities are formed on the non-skin surface side of the absorber 1 by the absorbent resin 6. It is preferable that the protective sheet 14 is formed wider in the width direction x than the region where the water-absorbent resin 6 is arranged on the coating sheet 5A, and is formed narrower in the width direction x than the absorber 1.

It is preferable that the absorbent article 11 is provided with liquid-impermeable side sheets 15 extending in the longitudinal direction y on both sides of the top sheet 12 in the width direction x. The side sheet 15 is joined to the top sheet 12 at the joint portion 18, and the inner portion in the width direction x from the joint portion 18 is formed so as to be able to stand up from the top sheet 12, and the side sheet 15 is formed to be erected from the top sheet 12 and is outward in the width direction x from the joint portion 18. A portion is provided so as to overlap the back sheet 13. When the inner portion of the side sheet 15 in the width direction x stands up, a rising flap 16 is formed, whereby lateral leakage of urine or the like can be prevented. Since the inner portion of the side sheet 15 in the width direction x is formed so as to be able to stand up from the top sheet 12, the side sheet 15 has a longitudinal direction y in the inner portion of the width direction x than the joint portion 18. It is preferable that the extending elastic member 17 for standing up is provided.

Fastening tape 21 is attached to the left and right end portions of the rear side portion (one portion in the longitudinal direction y) of the absorbent article 11. The fastening tape 21 is configured by providing a fastener 23 on the base sheet 22. The absorbent article 11 is placed in the crotch of the wearer, and the fastener 23 of the fastening tape 21 is joined to the outer surface (target tape 24 in FIG. 4) of the front side portion (the other portion in the longitudinal direction y) of the absorbent article 11. By doing so, it can be attached. As the fastener 23, a hook member of a hook, a loop, or a fastener or an adhesive can be used.

It is preferable that leg elastic members 19 extending in the longitudinal direction y are provided on both sides of the absorbent article 11 in the width direction x. The leg elastic member 19 can form gathers around the wearer's legs to improve the fit around the legs and prevent lateral leakage.

It is preferable that the waist elastic member 20 extending in the width direction x is provided at the end of the absorbent article 11 in the longitudinal direction y. The waist elastic member 20 forms waist gathers along the waist of the wearer to prevent leakage of urine or the like from the abdomen or back.

1: Absorbent 2: Absorbent core 3: Water-absorbent resin contained in the absorbent core 4: Openings 5, 5A, 5B: Coating sheet 6: Water-absorbent resin arranged on the coating sheet 11: Absorbent article 12: Top Sheet 13: Back sheet 14: Protective sheet

Claims (7)

It is an absorber that is used to absorb body fluids and has a skin surface side and a non-skin surface side.
The absorber has an absorbent core having an opening and a coating sheet that overlaps the opening and is provided at least on the non-skin surface side of the absorber.
The absorbent core contains hydrophilic fibers and a water-absorbent resin, and the absorbent core contains hydrophilic fibers and a water-absorbent resin.
On the skin surface side of the coating sheet provided on the non-skin surface side of the absorbent core, a water-absorbent resin is arranged at a portion overlapping the opening of the absorbent core.
An absorber characterized in that the under-load liquid passing rate of the water-absorbent resin arranged on the coating sheet is faster than the under-load liquid passing rate of the water-absorbent resin arranged on the absorbent core. The absorber according to claim 1, wherein the water-absorbent resin arranged on the coating sheet has a liquid passing rate under load for 10 seconds or less. The coating sheet is composed of cellulose fibers and is composed of cellulose fibers.
The absorber according to claim 1 or 2, wherein the water-absorbent resin arranged on the coating sheet is fixed to the coating sheet by an anionic or nonionic fixing agent. The absorber according to any one of claims 1 to 3, wherein a water-absorbent resin is arranged on the coating sheet in addition to a portion of the absorbent core that overlaps with the opening. The absorber according to any one of claims 1 to 4, wherein the coating sheet is adhered to the absorbent core with a hot melt adhesive. The absorber according to any one of claims 1 to 5 and
A liquid-permeable top sheet provided on the skin surface side of the absorber and
An absorbent article characterized by having a liquid-impermeable back sheet provided on the non-skin surface side of the absorbent body. A protective sheet is provided between the absorber and the back sheet.
The absorbent article according to claim 6, wherein the protective sheet is formed to be wider in the width direction than the region where the water-absorbent resin is arranged on the covering sheet and narrower in the width direction than the absorber.

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