TWI603725B - Disposable diapers - Google Patents

Description

Disposable disposable diaper

The present invention relates to a disposable disposable diaper, and more particularly to a disposable diaper for use in a body fluid absorbing portion comprising pulverized pulp and superabsorbent polymer particles.

It is also known that the body fluid absorbing portion in the disposable diaper contains pulverized pulp and superabsorbent polymer particles.

For example, the absorbent body of the disposable diaper described in Japanese Laid-Open Patent Publication No. 2002-315783 (Patent Document 1) is a high-absorbent polymer particle and a pulverized pulp. The liquid ratio is 40 g/g or more, and the liquid absorption rate according to the Vortex method is 20 seconds or less.

In addition, Japanese Patent Publication No. 6-503983 (Patent Document 2) proposes a structure for an absorbent body such as a disposable disposable diaper, and it is desirable to absorb the absorbent article immediately after discharging the exudate. When the absorbent gelling agent is tested according to the tea bag test, the synthetic urine can be absorbed at a rate of at least about 40% of its absorbent capacity in 10 seconds or less.

An example of the absorbent article described in Japanese Laid-Open Patent Publication No. 2009-61063 (Patent Document 3) is a disposable disposable diaper, wherein the absorbent article includes a liquid passing speed and a high absorption rate, and the water absorption speed is also high. High water-absorbing polymer.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2002-315783

[Patent Document 2] Japanese Patent Publication No. Hei 6-503983

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2009-61063

In the above-mentioned conventional technique, the superabsorbent polymer particles for absorbing body fluids and the absorbent gelling agent are preferably used in a high water absorption rate and have a high water absorption amount. However, according to the findings of the present inventors, the body fluid absorbing portion including such a superabsorbent polymer particle as a part of the core material rapidly expands the water absorbing polymer particles after water absorption, and tends to have a significant volume change. Big. In the body fluid absorbing portion in such a state, the skin of the wearer of the disposable diaper is tightly fitted, or the gap between the body fluid absorbing portion and the skin is narrowed, thereby giving the skin a skin. Strong sense of swelling, or enhance the feeling of sultry. Further, in the body fluid absorbing portion, even if the volume of a part of the crotch region is remarkably large, when a part of the body fluid is sandwiched between the legs, the abnormal swelling of the crotch region may cause a problem of unsightly appearance. A mother who sees a part of which the volume is significantly enlarged may have to be judged that the diaper must be renewed even if the body fluid absorbing portion has the residual force for absorbing body fluid.

In the invention, it is an object of the present invention to provide a disposable disposable diaper which is useful for eliminating such problems in the body fluid absorbing portion.

The object of the invention for solving the above-mentioned problems is to provide a front-rear direction and a wide-width direction, and a front waist region in front of the crotch region and a position in front of the crotch region and a rear side of the crotch region. At least the underarm region of the back waist region is formed with a body fluid absorbing portion, and the body fluid absorbing portion is covered with a liquid permeable surface sheet, and the liquid permeable sheet containing the pulverized pulp and the superabsorbent polymer particles is absorbed. A disposable diaper of a portion of the core material formed by the mixture of the materials.

As a feature of such an invention, it is as follows. In other words, the core material is formed with a plurality of press portions that are concavely formed in the thickness direction of the core material, and the press portion and the wrap sheet are joined to each other via a hot melt adhesive in the press portion. The core material is pressed in the press portion, and the thickness of the core material formed in the non-pressing portion formed between the adjacent press portions is 80% or less. The center-to-center distance between one of the press portions and the press portion at the closest position to one of the press portions is in the range of 2 to 14 mm. The superabsorbent polymer particles were smaller than the water absorption amount of 45 ml/g after 5 minutes from the start of the non-pressure water absorption test, and the water absorption amount under load was smaller than 14 g/g.

According to one aspect of the invention, the press portion is formed at a portion opposed to the surface sheet.

According to one aspect of the invention, the core material is covered with a liquid-impermeable inner sheet, and the press portion is formed at a portion facing the inner sheet.

According to one aspect of the invention, the press portion is formed with respect to the core material and the surface sheet.

According to one aspect of the invention, the press portion is formed in a state where the surface sheet and the inner sheet are not included.

According to one aspect of the invention, the body fluid absorbing portion extends from at least the crotch region toward at least one of the front waist region and the rear waist region, and the press portion is formed only in the armpit region.

According to one aspect of the invention, the body fluid absorbing portion extends from at least the crotch region toward at least one of the front waist region and the rear waist region, and the press portion extends in at least one of the portions extending toward the at least one side. form.

According to one aspect of the invention, the number of the press portions per 1 cm ² of the surface formed in the core material is reduced from at least one of the central portions of the crotch region in the front-rear direction.

According to one aspect of the invention, the amount of each of the pulverized pulp and the superabsorbent polymer particles in the core material is in the range of 100 to 350 g/m ² , the pulverized pulp and the superabsorbent polymer. The total amount of particles is in the range of 300 to 600 g/m ² .

According to one aspect of the invention, the superabsorbent polymer particles in the press portion are in a state of being close to each other than the superabsorbent polymer particles in the non-pressing portion.

In the disposable disposable diaper of the present invention, since a plurality of press portions are formed in a core material including the pulverized pulp and the superabsorbent polymer particles, the pulverized pulp and the superabsorbent polymer particles absorb the body fluid. Core material As the volume increases, the thickness of the body fluid absorbing portion accompanying this tends to be weakened. The diaper having such a body fluid absorbing portion can eliminate or alleviate various problems caused by the conventional body fluid absorbing portion, for example, the problem that a part of the body fluid absorbing portion is abnormally expanded; the so-called diaper wearer The skin is close to the skin, giving the wearer a strong sense of moistness.

[Formation for carrying out the invention]

Referring to the added drawings, the details of the disposable disposable diaper of the present invention are as follows.

Fig. 1 is a partially broken plan view showing a disposable diaper 1 as an example of a disposable disposable diaper. The disposable diaper 1 has a liquid-permeable surface sheet 2, a liquid-impermeable back sheet 3, and a body fluid-absorbent core material 4 interposed between the two sheets 2 and 3. The core material 4; the surface sheet 2 covering a portion of the surface of the core material 4; and the inner sheet 3 covering the inner surface portion of the core material 4 are formed into the body fluid absorbing portion 5. The body fluid absorbing portion 5 extends from the crotch region 7 to the front waist region 8 and the back waist region 9. The paper diaper 1 is further laminated with the outer sheet 6 from the outer side of the disposable diaper 1 with respect to the inner sheet 3 (see Fig. 2).

The disposable diaper 1 has a front-rear direction A and a width direction B. A crotch region 7 is formed in a central portion of the front-rear direction A, and a front waist region 8 is formed in front of the crotch region 7, and is located behind the armpit region 7. A back waist area 9 is formed. a plurality of front waists extending in the width direction B at both end portions of the front and rear direction A The peripheral elastic member 11 and a plurality of rear waist elastic members 12 extending in the width direction B are positioned between the surface sheet 2 and the back sheet 3, and are joined to at least one of the two sheets 2, 3 in an extended state.

A leakage preventing bank 13 extending in the front-rear direction A is formed on both sides of the wide direction B of the disposable diaper 1. A sleeve 14 is formed in the inner edge portion 13a of the leakage preventing bank 13, and the elastic member 16 extends in the longitudinal direction in the front-rear direction A on the inner side of the sleeve 14. In the both side edge portions 17 of the disposable diaper 1, a plurality of leg-surrounding elastic members 18 extending in an extended state in the front-rear direction A are positioned between the inner sheet 3 and the outer edge portion 19 of the leakage preventing bank 13, and are thermally welded. A primer (not shown) is bonded to at least one of the inner sheet 3 and the leakage preventing bank 13. A belt-shaped fastener 21 is attached to both side portions of the disposable diaper 1 in the back waist region 9. The clip 21 has a locking portion 22, and when the disposable diaper 1 is worn, the locking portion 22 can be detached from the target region (not shown) provided on the outer surface of the front waist region 8.

The disposable diaper 1 thus formed is symmetrical with respect to the center line CL which divides the size of the wide direction B into two equal parts. A plurality of dots 23 drawn on the surface sheet 2 in the disposable diaper 1 are ranges indicating the distribution of the press portion 51 to be described later.

Fig. 2 is a view showing a cut surface taken along line II-II of Fig. 1. However, in order to facilitate understanding of the state in which the members are overlapped in the underarm region 7, the shape and mutual positional relationship of the members are shown in a pattern. In such FIG. 2, the core material 4 is interposed between the surface sheet 2 and the inner sheet 3. The core material 4 is at least a mixture of the body fluid absorbent material including the pulverized pulp 41 and the superabsorbent polymer particles 42 (refer to FIG. 4), and the thinner mixture of the coated mixture 43 Paper 44 is formed. The thin paper 44 is composed of a thin paper 44a and a thin paper 44b. The mixture 43 and the thin paper 44 are joined via the first hot-melt adhesive HA1. The core material 4 is joined to the surface sheet 2 via the second hot-melt adhesive HA2, and joined to the inner sheet 3 via the third hot-melt adhesive HA3. The core material 4 and the surface sheet 2 and the back sheet 3 which are superposed thereon are formed with the body fluid absorbing portion 5 (see Fig. 4). The front sheet 2 and the inner sheet 3 are overlapped at a portion extending from the periphery of the core member 4, and joined to each other via the second and third heat-fusible agents HA2 and HA3. In the surface sheet 2, the outer edge portion 19 of the leakage preventing bank 13 is joined via the fourth hot-melt adhesive HA4. The inner edge portion 13a of the leakage preventing bank 13 and the both end portions in the front-rear direction A are joined to the waist regions of the front waist region 8 and the back waist region 9 via a hot-melt adhesive (not shown), but in the lower armpit region 7 is not joined to the surface sheet 2, and when the disposable diaper 1 is worn and the elastic member 16 is contracted, the inner edge portion 13 thereof is changed to a posture in which the surface sheet 2 stands up as indicated by an imaginary line.

In the inner sheet 3, the outer sheet 6 is laminated from the outer side of the disposable diaper 1 by using the fifth hot-melt adhesive HA5.

Further, in the body fluid absorbing portion 5 extending from the front waist region 8 to the back waist region 9 via the crotch region 7 in Fig. 1, the size in the front-rear direction A can be appropriately shortened. For example, the body fluid absorbing portion 5 may be present only in the infraorbital region 7, or may exist only in the infraorbital region 7 and the front waist region 8, or may exist only in the infraorbital region 7 and the back waist region 9.

In the disposable diaper 1 shown in Figs. 1 and 2, a non-woven fabric formed of thermoplastic synthetic fibers is used for the surface sheet 2, for example, a air-laid nonwoven fabric or a spunbonded nonwoven fabric; and a layer of a spunbonded nonwoven fabric, a melt-blown nonwoven fabric, and a spunbonded nonwoven fabric. The SMS of the integrated body is not woven. In an example of the airflow non-woven fabric, in the thermoplastic synthetic fiber, a composite fiber of polyethylene and polypropylene having a fineness of 1 to 4 dtex is used in a ratio of 10 to 35 g/m ² . In the inner sheet 3, a film formed of a thermoplastic synthetic resin is used, and for example, a polyethylene film having a thickness of 5 to 20 μm is used. The outer sheet 6 is made of a plastic material to prevent the outer surface of the disposable diaper 1 from being formed by the presence of the inner sheet 3, and is used by a user for forming a cloth shape, and is made of a thermoplastic synthetic fiber having a fineness of 1 to 4 dtex at 10 to 20 g. The ratio of /m ² is formed by the non-woven fabric used.

The pulverized pulp 41 and the superabsorbent polymer particles 42 (both with reference to Fig. 4) forming the mixture 43 of the core material 4 are respectively used in a range of 100 to 350 g/m ² in mass per unit area, and the pulp 41 is pulverized and highly absorbent. The total amount of the polymer particles 42 is in the range of 300 to 600 g/m ² . The tissue paper 44 covering the mixed body 43 is used in the field and is used as an example of a mass having 15 to 20 g/m ² .

The leakage preventing bank 13 is a non-woven fabric, and is more preferably subjected to a water-repellent treatment, and is formed of a substantially liquid-impermeable non-woven fabric on the disposable diaper 1.

3 and 4 are enlarged views showing a portion III in Fig. 1 and a cut surface taken along line IV-IV in an enlarged view thereof. The body fluid absorbing portion 5 is formed with a plurality of press portions 51 recessed from the surface sheet 2 in the thickness direction of the core member 4, and a non-pressing portion 52 is formed between the press portions 51 and 51.

The planar shape of the press portion 51 shown in Fig. 3 is not particularly limited. In the figure, the bottom surface portion of the press portion 51 is circular and the diameter D is in the range of 1.5 to 5 mm. The press portion 51 in the case where the planar shape is not circular is inscribed with a diameter E (refer to FIG. 5) at 1.5~ A planar shape such as a circle 56 (see FIG. 5) in the range of 5 mm is desirable. When the planar shape is not circular, it is desirable to have at least three shapes inscribed in the circle 56 at three places. The distribution of the press portion 51 in the body fluid absorbing portion 5 is not particularly limited, but is minimized among the center distances L between the press portions 51 between the one press portion 51 and the plurality of press portions 51 adjacent thereto. The distance between the centers of the center is ideal for the range of 2 to 14 mm. In other words, it is preferable that the center-to-center distance L between one of the press portions 51 and the press portion 51 at the closest position to the press portion 51 of one of the press portions 51 is in the range of 2 to 14 mm. When the center-to-center distance L is formed to be smaller than 2 mm between the plurality of press portions 51, the body fluid absorbing portion 5 becomes hard and is not easily deformed, which is undesirable. Further, when there are many cases where the center-to-center distance L is larger than 14 mm between the plurality of press portions 51, the body fluid absorbing portion 5 after the body fluid is absorbed tends to be thick, which is not preferable. The press portion 51 may be formed in a regular distribution as shown in the example with respect to the surface sheet 2, but may be irregularly distributed.

In FIG. 4, the body fluid absorbing portion 5 includes a surface sheet 2 covering the upper surface side of the core material 4 and the core material 4, a back sheet 3 covering the lower surface side of the core material 4, and an outer sheet 6 laminated on the back sheet 3. The press portion 51 is formed in a state including the surface sheet 2. The core material 4 includes at least a mixture 43 containing a pulverized pulp 41 and a body fluid absorbent material with the super absorbent polymer particles 42 and a thin paper 44 as a liquid permeable wrapping sheet of the coating mixture 43. The body fluid absorption unit 5 further includes first, second, third, and fifth hot-melt adhesives HA1, HA2, and HA3 for bonding the members to each other. HA5. The cross-sectional shape of the core material 4 and the body fluid absorbing portion 5 in Fig. 4 is a cross section formed by cutting the body fluid absorbing portion 5 which is formed at a low temperature by liquid nitrogen by a sharp cutter, and the cross section thereof can be enlarged by about 30 times. Observe and confirm.

In the body fluid absorbing portion 5 as viewed in the plane of the body fluid absorbing portion 5, the amount of the pulverized pulp 41 and the superabsorbent polymer particles 42 is almost constant regardless of the surface area of the body fluid absorbing portion 5 per 1 cm ² of the surface area of the body fluid absorbing portion 5. In other words, the amount of the pulverized pulp 41 and the superabsorbent polymer particles 42 per 1 cm ² of the area of the flat inner sheet 3 shown in Fig. 4 is almost constant. However, in the cross section of Fig. 4, in the press section 51, by pressing the core material 4, in the press section 51, the pulverized pulp 41 and the superabsorbent polymer particles 42 are brought close to each other, and the collection is closely attached. The pulverized pulps 41 and the superabsorbent polymer particles 42 are also close to each other, and are in close contact with each other, and the superabsorbent polymer particles 42 are in a state in which the rubber blocks are easily formed. However, in the non-pressing section 52, since the core material 4 is not pressed or pressed as much as the press section 51, the pulverized pulp 41 and the superabsorbent polymer particles 42 are separated from each other. In the press section 51, the mixture 43 and the tissue 44 are joined by the hot-melt adhesive HA1, and it is important to maintain the shape of the press section 51 regardless of whether or not the disposable diaper 1 is used.

The body fluid absorbing portion 5 in the state shown in Figs. 3 and 4 has the same composition as that of the body fluid absorbing portion 5, and has the same thickness, and has the same thickness as that of the non-pressing portion 52, or can be compared with the non-pressing portion. A body fluid absorbing portion (not shown) having a thicker thickness of 52 is obtained by applying embossing. In the embossing process, a roller having a pin for embossing corresponding to the press portion 51 is used, and it can be obtained by pressing the body fluid absorbing portion at a room temperature or a pin in a heated state. The thickness of the press portion 51 and the non-pressing portion 52 of the body fluid absorbing portion 5 thus obtained is in a state in which the inner sheet 3 and the outer sheet 6 are included in addition to the core material 4 and the surface sheet 2, and the KEYENCE system described later is used. The high-precision 2-dimensional laser displacement meter LJ-G030 is used for measurement. In the measurement of the thickness of the press portion 51, ten press portions 51 were selected from the width of 100 cm ² , and the laser beam of the displacement meter was irradiated toward the bottom surface of the press portion 51, and the respective thicknesses were measured to obtain an average value of the thickness. When the thickness of the non-pressing portion 52 was measured, 10 thick portions were selected from the width of 100 cm ² , and the thickness was measured by irradiating the laser light everywhere, and the average value of the thickness was obtained.

The press portion 51 in the body fluid absorption portion 5 at the time of excretion of urine suppresses an increase in the pulverized pulp 41 which is mixed by the press, and the superabsorbent polymer particles 42 which are brought close to each other by pressing are easily formed into glue. Block, and can inhibit the degree of expansion. As a result, it is possible to suppress the thickness of the body fluid absorbing portion 5 in the press portion 51 and the periphery thereof. Further, since the non-pressing portion 52 is restricted by the press portions 51 whose thickness is not thick by the operation of the both side portions in FIG. 4, the press portion 51 is not the same as the press portion 51, but the non-pressing portion 52 is also It is possible to suppress the case where the body fluid absorbing portion 5 becomes thick. Therefore, in the body fluid absorbing portion 5 of the illustrated example, the thickness of the body fluid absorbing portion 5 can be prevented from becoming significantly thicker in the crotch region 7 of the disposable diaper 1 as compared with the body fluid absorbing portion in which the press portion 51 is not formed. In such a case, there is no gap between the body fluid absorbing portion 5 having a thickened thickness and the skin, or a gap with the skin. In the case of being significantly narrowed, it is possible to suppress the fact that the wet feeling in the underarm region 7 becomes strong. Further, when the body fluid absorbing portion 5 having a large thickness is in a state of being sandwiched between the legs, the problem that the so-called body fluid absorbing portion 5 is abnormally expanded can be released or reduced.

In the disposable diaper 1, in order to surely exert such an effect, it is also important to define the water absorption characteristics of the superabsorbent polymer particles 42. In the superabsorbent polymer particles 42 for achieving such a purpose, it is preferable to use a non-pressurized water absorption amount of 45 ml/g or less and a water absorption amount under a load of 14 g/g or less.

The amount of no-pressure water absorption was measured using a Demand Wettalility Tester manufactured by Scientific Machine & Supply Co. The Tester used a 0.9% aqueous sodium chloride solution in physiological saline and a 250 nylon mesh network (N-No. 250HD manufactured by NBC Industries) in the net. The amount of the superabsorbent polymer particles used was 1 g. The amount of non-pressurized water absorption in the invention is a value after 5 minutes from the start of the water absorption test.

For the measurement of the water absorption amount under the load, a plastic cylinder having an inner diameter of 26 mm formed of a 250 nylon mesh was used. The superabsorbent polymer particles of mass S are placed in the cylinder, and a piston having a predetermined weight is placed in the cylinder to obtain the total mass W1. The cylinder was stood upright in a petri dish containing 25 g of physiological saline for 60 minutes. The mass W2 of the cylinder taken out from the culture dish was determined, and the amount of water absorption under the load was obtained by the following formula.

Water absorption under load (g/g) = (W2-W1)/S

In the paper diaper 1 , in order to enhance the effect of the body fluid absorbing portion 5, a sheet such as a non-woven fabric which is excellent in liquid permeability to the front and rear direction of the disposable diaper 1 may be used instead of the surface sheet 2, or may be bonded to the surface. thin All or part of the sheet 2 is used. As such a non-woven fabric, many of the fibers forming the non-woven fabric are oriented in the front-rear direction A of the disposable diaper 1. In the body fluid absorbing portion 5 in the state of FIG. 4, the superabsorbent polymer particles 42 are strongly pressed together with the pulverized pulp 41, the thin paper 44, the surface sheet 2, and the like in the press portion 51, so that the superabsorbent polymer particles 42 cannot be inflated toward the periphery. In the case where the space in which the water can be retained between the pulverized pulps 41 is small, the water absorption speed and the water absorption amount of the body fluid absorbing portion 5 may be lowered. Therefore, it is advantageous to prevent the leakage of the disposable diaper 1 or to lower the moist feeling by the fact that a part of the body fluid discharged to the crotch region 7 is diffused toward the front-rear direction A by the sheet which is good in the case of diffusing the body fluid.

Fig. 5 is a view similar to Fig. 3 showing an example of an embodiment, and the press portion 51 is enlarged to appear larger than this in Fig. 3. The press portion 51a of Fig. 5, which is one of the press portions 51, has a planar shape of a bottom portion which is approximately an equilateral triangle, and has three convex portions 55a, and the convex portions 55a are respectively inscribed in an imaginary circle 56. The diameter E of the circle 56 is in the range of 1.5 to 5 mm. Among the press portions 51 adjacent to the press portion 51a, between the press portion 51b closest to the press portion 51a and the press portion 51a, one of the three convex portions 55b of the press portion 51b and the press portion One of the convex portions 55a in 51a is opposed. A non-pressing portion 52 is formed between the convex portions 55a and 55b opposed to each other. When the press portion 51a and the press portion 51b are in the form of Fig. 5, between the press portions 51a, 51b, between the two press portions 51a, 51b, as compared with the portions where the convex portions 55a and 55b are not opposed. The dimension P of the extended non-press section 52 becomes relatively short. In such a non-pressing portion 52, the thickness after absorption of the body fluid can be changed as compared with the case where the size P is large. Reduced.

Fig. 6 is a view similar to Fig. 1 showing an example of an embodiment. In the disposable diaper 1 of Fig. 6, the distribution density of the surface sheet 2 formed on the press portion 51 of the body fluid absorbing portion 5, that is, the number of press portions 51 formed per 1 cm ^{2 of} the surface sheet 2 is in the front-rear direction A. Variety. The number of points per 1 cm ² of the dots 23 drawn on the surface sheet 2 is the largest in the first region 61 at the center portion in the front-rear direction A of the crotch region 7, and is the second in the front waist region 8. The third zone 62, 63 gradually decreases. The number of the press portions 51 per point ² of the point 23 indicates that the number of the press portions 51 per 1 cm ² is gradually decreased from the central portion of the crotch region 7 toward the front waist region 8 and the rear waist region 9. In the center portion of the crotch region 7 in the front-rear direction A, the thickness of the body fluid absorbing portion 5 after absorbing the body fluid is increased, and the body fluid is absorbed by the presence of the press portion 51. The second to fifth regions, where the speed is not too slow, absorb body fluids, preventing the retention of body fluids in the central portion. Although not shown, the disposable diaper 1 may be formed only with the first, second, and third regions 61, 62, and 63, and may be implemented without forming the fourth and fifth regions 64 and 65. Further, the first, fourth, and fifth regions 61, 64, and 65 are formed, and the second and third regions 62 and 63 may not be formed. Further, the core material 4 and the body fluid absorbing portion 5 including this are present only in the crotch region 7 and the front waist region 8, and the first, second, and third regions 61, 62, and 63 may be formed. The core material 4 and the body fluid absorbing portion 5 containing the same are present only in the crotch region 7 and the back waist region 9, and may be implemented in the form in which only the first, fourth, and fifth regions 61, 64, and 65 are formed. . Further, the core material 4 and the body fluid absorbing portion 5 containing this are only present in the subgingival region 7, and may be carried out only in the form in which the first region 61 is formed.

Fig. 7 is a view similar to Fig. 4 showing an example of an embodiment. The press portion 51 in Fig. 7 is formed with respect to the core material 4, and the press sheet 51 does not include the surface sheet 2. In the core material 4, the mixture 43 and the thin paper 44b are pressed from the surface sheet 2 toward the inner sheet 3, that is, the press portion 51 is formed in the core material 4 by pressing in the thickness direction of the core material 4. The surface sheet 2 is flatly enlarged, and the non-pressing portion 52 in the core material 4 is joined via the hot-melt adhesive HA2.

In the body fluid absorbing portion 5 as the aspect of FIG. 7, when a non-woven fabric having a bulky and soft skin feel is used as the surface sheet 2, the so-called surface sheet 2 can be prevented by forming the press sheet 51 on the surface sheet 2 thereof. The problem of damaged skin touch occurs. In the case where the thin paper 44b is easily stretched, when the press portion 51 in Fig. 7 is formed, the thin paper 44b which is easily stretched between the portions of the press portions 51 and 51 which are not adjacent to the press portion 52 is used. In contrast, the formation of the hybrid 43 is tightly crimped. As a result, when the non-pressing portion 52 absorbs the body fluid, the thickness tends to be weak, and it becomes a portion that does not easily swell even if the body fluid is absorbed. Further, by partially separating the surface sheet 2 from the tissue 44b, it is easy to prevent the color of the core material 4 which is stained by urine from being seen through the surface sheet.

With respect to the core material 4 as the aspect of FIG. 7, the thickness of the press portion 51 and the thickness of the so-called non-pressing portion 52 mean the core material 4 in a state in which the surface sheet 2 and the inner sheet 3 and the outer sheet 6 are not included. The value at which the measurement was taken. The core material 4 which can be subjected to such measurement is a process for producing the body fluid absorbing portion 5 by extracting the surface sheet 2 and the back sheet 3 which are not joined. The core material 4 is available.

Fig. 8 is a view showing a distribution state of the press portion 51 in the core material 4 used to observe the change in thickness when the core material 4 absorbs water. 4 is a tissue paper core coated evenly with a mass 17g / m ² of mixing pulverized pulp 220g / m ² and described in Table 1 to any one of a mixture of the superabsorbent polymer particles 220g / m ² obtained in 43 (see FIG. 7 The cross-sectional shape of Fig. 7 was formed to form a rectangle having a length of 410 mm and a width of 145 mm. In the figure, the thin paper 44b of the core material 4 and the press portion 51 formed on the thin paper 44b are visible. Here, the planar shape of the press portion 51 is an equilateral triangle having a length Q of one side of approximately 3 mm. The press portion 51 is again positioned at each corner portion of the regular hexagon shown by the imaginary line, and the corner portions are opposed to each other between the press portions 51, and the corner portion and the corner portion are separated by only the distance P. The thickness of the core material 4 in the press portion 51 and the thickness of the non-pressing portion 52 of the core material 4 formed between the press portions 51 are shown in Table 2. The center-to-center distance L between the press sections 51 is also shown in Table 2. The change in thickness when the core material 4 absorbed artificial urine instead of water was observed, and the results were summarized in Table 2.

In this observation, the superabsorbent polymer particles used have the water absorption characteristics shown in Table 1, that is, three types of SAP-A, SAP-B, and SAP-C, and the superabsorbent polymer particles are Commercially available.

The water absorption ratio and the water retention ratio in Table 1 were measured in accordance with JIS K 7223. Specifically, 1.0 g of superabsorbent polymer particles were placed in a mesh bag and immersed in physiological saline for 1 hour. Next, the net bag was pulled up to remove moisture by hanging for 15 minutes, and the water absorption amount of the superabsorbent polymer particles was measured as the water absorption ratio. Also, after measuring the removal of moisture and dehydrating with a centrifugal separator The weight of the mesh bag is used to determine the water retention ratio.

In Table 2, in the artificial urine, 200 g of urea, 80 g of sodium chloride, 80 g of magnesium sulfate, 80 g of calcium chloride, and a pigment (cyan No. 1) of about 1 g were dissolved in the ion-exchanged water 101. Artificial urine has a cyan color.

In the artificial urine, 120 ml was divided into three times, and 40 ml was injected into the central portion of the front-back direction A and the wide direction B of the core material 4 at intervals of 5 minutes to allow absorption. When injecting, use a burette. The core material 4 when the artificial urine is injected is placed on a polyethylene film laid on a horizontal disk surface.

The distance between the centers indicates the distance between the centers of the pins in the embossing processing rolls (not shown) used to form the press portion, and the distance between the centers is almost the same as the distance between the centers of the press portions in the core material.

The thickness of the press section and the non-press section in the "thickness of the core material" in Table 2 means that the core material before the artificial urine is placed on the horizontal stage, and the high-precision 2-dimensional laser displacement meter LJ-G030 manufactured by KEYENCE is used. , the value at the time of measurement that is not in contact with the core material.

The thickness before the artificial urine injection and the thickness after the artificial urine injection in the "change in the thickness of the non-pressing portion" in Table 2 means that the core material 4 placed on the horizontal surface has a dial gauge having a diameter of 50 mm. The probe was applied with a measurement load of 6.5 g/cm ² from the upper contact by reading the measured value of the measurement at this time. The thickness after artificial urine injection is measured after 5 minutes after injection.

The diffusion length is an average value (n=5) of the value of the maximum size of the artificial urine which is diffused into the front-back direction A of the core material 4 after 5 minutes from the injection of 80 ml of artificial urine.

In the core material after the evaluation, the change in the thickness after the artificial urine injection was small, and it was judged that the allowable degree was the increase in the thickness of the non-pressing portion after injecting 120 ml of artificial urine in Table 2 ((TT ₀₎ ) / T ₀ ) is below 2.2. What can be achieved in this increment is when the superabsorbent polymer particles are SAP-A. Further, SAP-A can exert such an effect. It is conceivable that the water absorption amount after 5 minutes from the non-pressurized water absorption test for SAP-A from the evaluation contents of Table 1 is 45 ml/g or less, and more preferably The amount of water absorption under a load of 14 ml/g or less is more preferably about 40 g/g or less, and more preferably about 12 g/g or less. Further, the thickness of the press portion is preferably 80% or less of the thickness of the non-pressing portion when measuring according to the non-contact type, and the distance L between the center portions of the press portion is preferably 2 to 14 mm.

In one embodiment of the invention, the press portion 51 may be formed in the core material 4 on a surface facing the inner sheet 3. At this time, the inner sheet 3 is included in the press portion 51 and is not included.

In the other aspect of the embodiment, the disposable disposable diaper can be implemented by replacing the open type diaper 1 of the illustrated example with a pants type diaper.

1‧‧‧paper diapers

2‧‧‧Surface

3‧‧‧ inside sheet

4‧‧‧ core material

5‧‧‧ body fluid absorption department

7‧‧‧胯下域

8‧‧‧ front waist area

9‧‧‧Back waist area

41‧‧‧Smashed pulp

42‧‧‧Superabsorbent polymer particles

44, 44a, 44b‧‧‧ parcel sheet

51‧‧‧Squeeze

52‧‧‧Unsqueezed section

A‧‧‧ front and rear direction

B‧‧‧ Wide direction

HA1‧‧‧Hot melt adhesive

[Fig. 1] A partially broken top view of the disposable disposable diaper.

Fig. 2 is a view showing a cut surface taken along line II-II of Fig. 1;

FIG. 3 is an enlarged view of a portion III of FIG. 1.

Fig. 4 is a view showing a cut surface taken along line IV-IV of Fig. 3;

FIG. 5 is a view similar to FIG. 3 showing an example of an embodiment.

Fig. 6 is a view similar to Fig. 1 showing an example of an embodiment.

Fig. 7 is a view similar to Fig. 4 showing an example of an embodiment.

Fig. 8 is a view showing an example of a distribution state of a press section.

2‧‧‧Surface

5‧‧‧ body fluid absorption department

51‧‧‧Squeeze

D‧‧‧diameter

L‧‧‧Center distance

52‧‧‧Unsqueezed section

Claims (10)

A disposable disposable diaper having a front-rear direction and a wide direction, and comprising: a front waist region, a back waist region, an underarm region located between the front waist region and the front waist region, and at least forming In the body fluid absorbing portion of the crotch region, the body fluid absorbing portion includes a core material formed by coating a liquid-permeable absorbing sheet with a mixture of a pulverized pulp and a body fluid absorbing material of superabsorbent polymer particles. And a liquid-permeable surface sheet covering at least a part of the core material, wherein the core material is formed with a plurality of press portions that are concavely formed in a thickness direction of the core material, and the mixture is in the press portion The wrapping sheet is joined to each other via a hot-melt adhesive, and in the press portion, the core material has 80% or less of a thickness of the core material formed in a non-pressing portion between the adjacent press portions. In the non-pressing portion, the pulverized pulp and the superabsorbent polymer particles are separated and dispersed with respect to the press portion, with respect to the aforementioned The pulverized portion is in a state in which the pulverized pulp is separated and dispersed, and the superabsorbent polymer particles are separated and dispersed with respect to the press portion, and each of the press portions is pressed in each of the presses. The distance between the centers of the press portions at the most recent position is in the range of 2 to 14 mm, and the water-absorbent amount of the superabsorbent polymer particles after 5 minutes from the start of the non-pressure water absorption test is 45 ml/g or less. The press portion is formed at a portion facing the surface sheet, and the surface sheet is formed of a liquid-permeable nonwoven fabric, and more fibers than the half of the fibers forming the nonwoven fabric are oriented in the front-rear direction. The disposable diaper according to claim 1, wherein each of the plurality of press portions has three convex portions, and the three convex portions are inscribed in an imaginary circle, and the press portion is It is located at each corner of the imaginary regular hexagon and is arranged such that the convex portions face each other. The disposable diaper according to claim 1, further comprising at least a portion of the liquid-impermeable back sheet covering the lower surface of the core material, wherein the press portion does not include the surface sheet and The state of the aforementioned inner sheet is formed. The disposable diaper according to claim 1, wherein the body fluid absorbing portion extends from at least the crotch region toward at least one of the front waist region and the back waist region, and the press portion is only It is formed in the aforementioned subfield. The disposable diaper according to claim 1, wherein the body fluid absorbing portion extends from the crotch region toward at least one of the front waist region and the back waist region, and the press portion The body fluid absorbing portion is also formed to extend toward at least one of the front waist region and the back waist region. The disposable disposable diaper according to the first aspect of the invention, wherein the number of the press portions per 1 cm ² of the surface formed in the core material is from the central portion of the crotch region toward the front At least one of the waist area and the aforementioned back waist area is reduced. The disposable diaper according to the first aspect of the invention, wherein the pulverized pulp and the superabsorbent polymer particles in the core material have a mass of 100 to 350 g/m ² , and the pulverization The total mass of the pulp and the above-mentioned superabsorbent polymer particles is in the range of 300 to 600 g/m ² . The disposable diaper according to the first aspect of the invention, wherein the superabsorbent polymer particles in the press portion are compared with the superabsorbent polymer particles in the non-pressing portion. More dense. The disposable diaper according to claim 1, wherein the superabsorbent polymer particles have a non-pressure-absorbing water absorption of 40 ml/g or less. The disposable diaper according to claim 1, wherein the diameter of the press portion formed into a circular shape is in the range of 1.5 to 5 mm.