JP5366992B2 - Disposable diapers - Google Patents

Abstract

[Problem] To provide a disposable diaper from which a fragrance is not discharged due to moisture present during storage before use or the sweat of a wearer while being worn, but from which a fragrance is discharged when excretion occurs. [Solution] The problem can be solved by a disposable diaper characterized by incorporating, on the side of a liquid-impermeable sheet (11) that is towards a surface sheet (30), an alkaline substance (80) which dissolves in urine and renders the urine alkaline, and microcapsules (90) in which a core material is a fragrance and a membrane material is soluble in urine that has been rendered alkaline by the alkaline substance (80).

Description

  The present invention relates to a disposable diaper having a function of notifying the presence or absence of excretion of urine or the like by aroma.

  Many of the disposable diapers currently widely used are provided with an indicator that makes it possible to visually recognize the presence or absence of excretion of urine or the like from the outside by coloration. The user can recognize that there is excretion by visually recognizing the coloration (coloring or discoloration) or decoloring of the indicator from the outside while wearing the disposable diaper, and can use it as a guideline for changing the diaper. (See Patent Documents 1 and 2).

  On the other hand, in order to solve the problem that the change in the color of the indicator cannot be confirmed when clothes such as pants are worn on a disposable diaper, a microcapsule that releases a fragrance when it comes into contact with excrement may be used. It has been proposed (see Patent Documents 3 and 4).

JP 2008-54991 A JP 2008-99947 A JP 2000-093456 A JP 2007-268221 A

  However, since conventional microcapsules release fragrance by contact with moisture, the fragrance is released by moisture in storage before use or sweat of the wearer during wearing, and the difference in fragrance before and after excretion Cannot be identified, and there is a problem that the generation of aroma during excretion is insufficient or disappears.

  Therefore, a main problem of the present invention is to provide a disposable diaper in which perfume is not released due to moisture in storage before use or sweat of a wearer during wearing, and the perfume is released when excreted. .

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
In a disposable diaper comprising a liquid-permeable surface sheet, a liquid-impermeable sheet, and an absorbent body interposed therebetween,
An alkaline substance that dissolves in urine to make the urine alkaline, and a microcapsule that is soluble in urine in which the core material is a fragrance and the membrane material is made alkaline by the alkaline substance from the liquid-impermeable sheet. Including on the seat side,
A disposable diaper characterized by that.

(Function and effect)
In such a disposable diaper, urine excreted from the wearer is supplied to the surface sheet side from the liquid-impermeable sheet. The urine becomes alkaline due to dissolution of the built-in alkaline substance, and comes into contact with the microcapsules to dissolve the membrane material. As a result, the fragrance | flavor currently hold | maintained in the microcapsule discharge | releases, a fragrance diffuses out of a diaper, and the person other than a wearer can know the presence or absence of excretion by sniffing the fragrance. Therefore, since the membrane material does not dissolve when moisture is directly supplied to the microcapsule, a situation occurs in which the fragrance is released due to moisture in storage before use or sweat of the wearer during wearing. It becomes difficult.

<Invention of Claim 2>
The disposable diaper of Claim 1 which contains the said alkaline substance and the said microcapsule only in the thickness direction range from the bottom part of the said absorber to the surface of the said liquid-impermeable sheet.

(Function and effect)
Urine in which alkaline substance, microcapsule material, and perfume are dissolved or mixed by limiting the content of alkaline substance and microcapsule to the thickness direction range from the bottom of the absorber to the surface of the liquid-impermeable sheet However, it becomes difficult to return to the surface sheet side from the absorbent body, and it is possible to reduce the possibility that urine containing an alkaline substance or the like leaks from the surface sheet and adheres to the wearer's skin, resulting in rough skin or the like.

<Invention of Claim 3>
While containing the alkaline substance on the surface sheet side than the microcapsule,
3. The disposable diaper according to claim 2, wherein the microcapsule-containing portion is provided only inside a peripheral portion of the alkaline substance-containing portion in a plan view.

(Function and effect)
Thus, by arranging the microcapsule-containing part and the alkaline substance-containing part, the contact efficiency between the urine and the alkaline substance is increased, and the contact efficiency between the urine in which the alkaline substance is dissolved and the microcapsule is also increased. As a result, it becomes possible to generate aroma more efficiently.

<Invention of Claim 4>
The absorbent body is wrapped by a packaging sheet made of nonwoven fabric or crepe paper,
4. The method according to claim 1, wherein the alkaline substance is contained in a portion of the packaging sheet located below the absorber, and the microcapsule is contained on the packaging sheet side surface of the liquid-impermeable sheet. The disposable diaper described in the item.

(Function and effect)
When the alkaline substance and the microcapsule are provided in such a member, the contact efficiency between the urine and the alkaline substance is increased, and the contact efficiency between the urine in which the alkaline substance is dissolved and the microcapsule is also increased. Can be generated. Moreover, since it can manufacture only by apply | coating an alkaline substance and a microcapsule with respect to a packaging sheet and a liquid-impermeable sheet, there exists an advantage that manufacture is easy.

<Invention of Claim 5>
The alkaline substance is contained in the crotch part and the front part and the rear part thereof, respectively, and the basis weight of the alkaline substance in the front part and the rear part is greater than the basis weight of the alkaline substance in the crotch part. The disposable diaper of any one of 4.

(Function and effect)
In general, in disposable diapers, the amount of urine supplied to the crotch is large, and the amount of urine supplied to both the front and rear sides of the crotch is small. Thus, the keep front portion and a rear portion of the crotch portion becomes small dissolution amount of luer alkali substances against urine, dissolution of the film material of the microcapsule, which may in turn generate the aroma becomes insufficient. Therefore, as described above, it is desirable to increase the basis weight of the alkaline substance at both the front and rear sides of the crotch portion.

<Invention of Claim 6>
The alkaline substance is a substance that dissolves in the urine to bring the pH of the urine to 11-12, and the membrane material of the microcapsule is soluble in the temperature range of 20-80 ° C. and in the alkaline region of pH 11-14. The disposable diaper of any one of Claims 1-5 which is a thing.
May be provided.

(Function and effect)
The alkaline substance and the microcapsule film material of the present invention are preferably such.

  As described above, according to the present invention, there is an advantage that the fragrance is not released due to moisture in storage before use or sweat of the wearer during wearing, and the fragrance is released when excreted. Brought about.

It is a top view in the state where the diaper was developed showing the inside of a pants type disposable diaper. It is a top view in the state where the diaper was developed showing the outer surface of a pants type disposable diaper. FIG. 3 is a 3-3 cross-sectional view of FIG. 1. FIG. 4 is a sectional view taken along the line 4-4 in FIG. 1. FIG. 5 is a sectional view taken along line 5-5 in FIG. 1. It is a top view in the state where the diaper was developed showing only the principal part of a pants type disposable diaper. It is sectional drawing which shows only the principal part of a pants type disposable diaper. It is a perspective view of a pants type disposable diaper. It is a principal part expanded sectional view of various forms. It is a principal part expanded sectional view of various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
1 to 8 show an example 100 of a pants-type disposable diaper. The pants-type disposable diaper 100 includes an exterior sheet 12 that forms the outer surface (rear surface) of the product and an interior body 200 that is attached to the inner surface of the exterior sheet 12. The interior body 200 is a part that absorbs and holds excrement such as urine, and the exterior sheet 12 is a part that is worn by the wearer. In addition, the dot pattern part in sectional drawing has shown the junction part which joins each structural member, and is formed by solid, beads, curtains, summits, spiral application, etc., such as a hot-melt-adhesive. The “front-rear direction” means the direction connecting the ventral side (front side) and the back side (rear side), “width direction” means the direction (left-right direction) orthogonal to the front-rear direction, and “up-down direction "In the state of wearing the diaper 100, that is, the direction perpendicular to the waistline direction when the diaper 100 is folded in two at the crotch portion so that both sides of the front body and the back body side of the diaper 100 are overlapped, in other words, For example, it means a direction connecting the waist opening WO side and the crotch side.

(Interior body)
The interior body 200 can take any shape, but is rectangular in the illustrated form. As shown in FIGS. 3 to 5, the interior body 200 includes a surface sheet 30 on the body side, a liquid-impermeable sheet 11, and an absorption element 50 interposed therebetween. Yes, it is the main body that has the absorption function. Reference numeral 40 denotes an intermediate sheet (second sheet) provided between the top sheet 30 and the absorbent element 50 in order to quickly transfer the liquid that has passed through the top sheet 30 to the absorbent element 50. Shows barrier cuffs 60 that stand on the body side and are provided on both sides of the interior body 200 in order to prevent excrement from leaking to both sides of the interior body 200.

(Surface sheet)
The top sheet 30 has a property of transmitting liquid, and examples thereof include a porous or non-porous nonwoven fabric, a porous plastic sheet, and the like. Of these, the nonwoven fabric is not particularly limited as to what the raw fiber is. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of them. Etc. can be illustrated. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method. For example, if flexibility and drapeability are required, the spunbond method and spunlace method are preferable. If bulkiness and softness are required, the air-through method, point bond method, and thermal bond method are preferable processing methods. .

  Further, the top sheet 30 may be composed of one sheet or may be composed of a laminated sheet obtained by bonding two or more sheets. Similarly, the top sheet 30 may be composed of one sheet or two or more sheets in the planar direction.

  When the barrier cuff 60 is provided, both side portions of the top sheet 30 pass between the liquid-impermeable sheet 11 and the barrier cuff 60 to the back side of the absorbent element 50 to prevent liquid penetration. It is preferable to adhere to the impermeable sheet 11 and the barrier cuff 60 with a hot melt adhesive or the like.

(Intermediate sheet)
An intermediate sheet (also referred to as “second sheet”) 40 having a higher liquid permeation rate than the top sheet 30 can be provided to quickly transfer the liquid that has passed through the top sheet 30 to the absorber. This intermediate sheet 40 not only improves the absorption performance of the absorbent by quickly transferring the liquid to the absorbent body, but also prevents the “reversed” phenomenon of the absorbed liquid from the absorbent body, so that the top sheet 30 is always dried. It can be made into the state which carried out. The intermediate sheet 40 can be omitted.

Examples of the intermediate sheet 40 include the same material as the top sheet 30, spunlace, spunbond, SMS, pulp nonwoven fabric, mixed sheet of pulp and rayon, point bond, or crepe paper. In particular, an air-through nonwoven fabric is preferable because it is bulky. It is preferable to use a core-sheath composite fiber for the air-through nonwoven fabric. In this case, the resin used for the core may be polypropylene (PP), but polyester (PET) having high rigidity is preferable. Basis weight is preferably ^{20~80g / m 2, 25~60g / m} 2 is more preferable. The thickness of the raw fiber of the nonwoven fabric is preferably 2.2 to 10 dtex. In order to make the nonwoven fabric bulky, it is also preferable to use an eccentric fiber, a hollow fiber, or an eccentric and hollow fiber that does not have a core at the center as the mixed fiber of all or part of the raw fiber.

  The intermediate sheet 40 in the illustrated form is disposed in the center shorter than the width of the absorber 56, but may be provided over the entire width. The length of the intermediate sheet 40 in the longitudinal direction may be the same as the length of the absorbent body 56 or may be within a short length range centered on the region that receives the liquid.

(Liquid impervious sheet)
The material of the liquid-impermeable sheet 11 is not particularly limited. For example, a plastic film made of an olefin resin such as polyethylene or polypropylene, a laminated nonwoven fabric provided with a plastic film on the surface of the nonwoven fabric, or a plastic film For example, a laminated sheet in which a nonwoven fabric or the like is laminated and bonded to each other can be exemplified. For the liquid-impermeable sheet 11, it is preferable to use a liquid-impermeable and moisture-permeable material that has been preferred in recent years from the viewpoint of preventing stuffiness. As a plastic film having moisture permeability, a microporous plastic film obtained by kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene, forming a sheet, and then stretching in a uniaxial or biaxial direction. Is widely used. In addition, non-woven fabric using micro-denier fibers, leakproof reinforcement by reducing the voids of the fibers by applying heat or pressure, and methods such as applying a superabsorbent resin or hydrophobic resin or water repellent Thus, a sheet that is liquid-impermeable without using a plastic film can also be used as the liquid-impermeable sheet 11.

  The liquid-impermeable sheet 11 is preferably extended around both sides of the absorbent element 50 to both sides of the side surface 30 of the absorbent element 50 in order to improve leakage prevention. The width of this extended portion is suitably about 5 to 20 mm on each of the left and right sides.

(Barrier cuffs)
The barrier cuff 60 is a belt-like member that extends over the entire front and rear direction along both side portions of the interior body 200, blocks urine and soft stool that move laterally along the top sheet 30, and prevents side leakage. It is provided for this purpose. The barrier cuff 60 of the present embodiment is provided so as to stand up from the side portion of the interior body 200, the base side portion stands up obliquely toward the center in the width direction, and the tip side portion from the intermediate portion has a width. It stands up diagonally outward in the direction.

  More specifically, the barrier cuff 60 is formed by folding a belt-like barrier sheet 62 having a length equal to the length in the front-rear direction of the interior body 200 and folding it in the width direction. In addition, a plurality of elongated elastic elastic members 63 are fixed along the longitudinal direction at intervals in the width direction. An end of the barrier cuff 60 opposite to the folded portion in the width direction is an attachment portion 65 fixed to the back surface of the side edge of the interior body 200, and portions other than the attachment portion 65 protrude from the attachment portion 65. It is set as the protrusion part 66 (part by the side of a folding | turning part). Further, both end portions in the front-rear direction of the protruding portion 66 extend from the mounting portion 65 to the side surface of the topsheet 30 through the side portion of the interior body 200 and are hot-melted to the side surface of the topsheet 30. The base side portion is fixed to the front and rear fixing portion 67 by an adhesive or heat seal, and the tip side portion is folded back outward in the width direction from the tip of the base side portion and fixed to the base side portion. An intermediate part in the front-rear direction of the protruding part is an unfixed free part (inner free part), and an elongated elastic member 63 extending in the front-rear direction is fixed to the free part in an extended state.

The barrier sheet 62 is made of a spunbonded nonwoven fabric (SS, SSS, etc.), SMS nonwoven fabric (SMS, SSMMS, etc.), a melt-blown nonwoven fabric having excellent uniformity and concealment, and water repellent with silicon as necessary. A treated product can be suitably used, and the fiber basis weight is preferably about 10 to 30 g / m ² . As the elongated elastic elastic member 63, rubber thread or the like can be used. When spandex thread rubber is used, the thickness is preferably 470 to 1240 dtex, more preferably 620 to 940 dtex. The elongation rate at the time of fixation is preferably 150 to 350%, more preferably 200 to 300%. The term “elongation rate” means a value when the natural length is 100%. Further, as shown in the drawing, a waterproof film can be interposed between the barrier sheets folded in two.

  The number of the elongated elastic stretch members 63 provided in the free part of the barrier cuff 60 is preferably 2-6, and more preferably 3-5. The arrangement interval 60d is suitably 3 to 10 mm. If comprised in this way, in the range which has arrange | positioned the elongate elastic expansion-contraction member 63, it will become easy to contact | abut with respect to skin. The elongated elastic elastic member 63 may be disposed not only at the distal end side but also at the base side.

  The fixing target of the attachment portion 65 of the barrier cuff 60 can be an appropriate member such as the top sheet 30, the liquid-impermeable sheet 11, the absorbent element 50 in the interior body 200.

  In the barrier cuff 60 thus configured, the contraction force of the elongated elastic elastic member 63 acts to bring the both ends in the front-rear direction close to each other, but the both ends of the projecting portion 66 are fixed so that they do not stand up. On the other hand, since they are non-fixed free portions, only the free portions stand up against the body side as shown in FIG. In particular, when the attachment portion 65 is located on the back surface side of the interior body 200, the barrier cuff 60 stands up so that the barrier cuff 60 opens outward in the width direction at and around the crotch portion. It comes in contact, and the fit is improved.

  The dimensions of the barrier cuff 60 can be appropriately determined. In the case of an infant paper diaper, for example, as shown in FIG. 7, the standing height of the barrier cuff 60 (the length in the width direction of the protruding portion 66 in the unfolded state) W6 is It is preferably 15 to 60 mm, particularly 20 to 40 mm. In addition, when the barrier cuff 60 is flatly folded so that the barrier cuff 60 is parallel to the surface of the top sheet 30, the distance W3 between the innermost folds is preferably 60 to 190 mm, particularly preferably 70 to 140 mm.

  Unlike the illustrated embodiment, double (two rows) of barrier cuffs can be provided on the left and right sides of the interior body 200.

(Absorption element)
The absorbent element 50 includes an absorbent body 56 and a packaging sheet 58 that wraps the entire absorbent body 56. The packaging sheet 58 can be omitted.

(Absorber)
The absorber 56 can be formed of an aggregate of fibers. As this fiber assembly, a filament assembly obtained by opening, as necessary, synthetic fiber tows (fiber bundles) such as cellulose acetate as well as short fibers such as cotton-like pulp and synthetic fibers Can also be used. The fiber basis weight can be set to, for example, about 100 to 300 g / m ² when cotton-like pulp or short fibers are stacked, and in the case of a filament aggregate, for example, about 30 to 120 g / m ^2. Can do. The fineness in the case of a synthetic fiber is 1-16 dtex, for example, Preferably it is 1-10 dtex, More preferably, it is 1-5 dtex. In the case of a filament aggregate, the filament may be a non-crimped fiber, but is preferably a crimped fiber. The crimped degree of the crimped fiber can be, for example, 5 to 75, preferably 10 to 50, and more preferably about 15 to 50 per inch. Further, a crimped fiber that is uniformly crimped is often used. It is preferable to disperse and hold superabsorbent polymer particles in the absorber 56.

  Although the absorbent body 56 may be rectangular, as shown in FIG. 6, as shown in FIG. 6, the hourglass has a front end portion, a rear end portion, and a narrow portion narrower than the front end portion and the rear end portion. The shape is preferable because the fit of the absorbent body 56 and the barrier cuff 60 around the legs is improved.

  Moreover, although the dimension of an absorber can be determined suitably, it is preferable to extend to the peripheral part of the interior body, or its vicinity in the front-back direction and the width direction.

(Superabsorbent polymer particles)
The absorber 56 can contain superabsorbent polymer particles in a part or all thereof. Superabsorbent polymer particles include “powder” in addition to “particles”. As the particle diameter of the superabsorbent polymer particles, those used in this type of absorbent article can be used as they are, and those having a particle size of 1000 μm or less, particularly 150 to 400 μm are desirable. The material of the superabsorbent polymer particles can be used without any particular limitation, but those having a water absorption of 40 g / g or more are suitable. High-absorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, and sodium carboxymethylcellulose crosslinks. Or an acrylic acid (salt) polymer can be used. As the shape of the superabsorbent polymer particles, a commonly used granular material is suitable, but other shapes can also be used.

  As the superabsorbent polymer particles, those having a water absorption rate of 40 seconds or less are preferably used. When the water absorption speed exceeds 40 seconds, so-called reversion in which the liquid supplied into the absorber 56 returns to the outside of the absorber 56 is likely to occur.

  Further, as the superabsorbent polymer particles, those having a gel strength of 1000 Pa or more are preferably used. Thereby, even if it is a case where it is set as the bulky absorber 56, the sticky feeling after liquid absorption can be suppressed effectively.

The basis weight of the superabsorbent polymer particles can be appropriately determined according to the amount of absorption required for the use of the absorber 56. Therefore, although it cannot be said unconditionally, it can be set to 50 to 350 g / m ² . If the amount of polymer is less than 50 g / m ^2, it is difficult to secure the absorption amount. When it exceeds 350 g / m ² , the effect is saturated.

  If necessary, the superabsorbent polymer particles can adjust the spraying density or spraying amount in the plane direction of the absorber 56. For example, it is possible to increase the application amount of the liquid excretion site as compared to other sites. When gender differences are taken into account, men can increase the front spray density (amount), while women can increase the center spray density (amount). In addition, a portion where no polymer exists locally (for example, in a spot shape) in the planar direction of the absorber 56 can also be provided.

(Packaging sheet)
When the packaging sheet 58 is used, as the material, tissue paper, particularly crepe paper, non-woven fabric, polylaminated non-woven fabric, a sheet with small holes, or the like can be used. However, it is desirable that the superabsorbent polymer particles be a sheet that does not escape. When a nonwoven fabric is used in place of the crepe paper, a hydrophilic SMS nonwoven fabric (SMS, SSMMS, etc.) is particularly suitable, and the material can be polypropylene, polyethylene / polypropylene composite material, or the like. The basis weight is preferably 5 to 40 g / m ² , particularly 10 to 30 g / m ² .

  The packaging form of the packaging sheet 58 can be determined as appropriate, but from the viewpoint of ease of manufacture and prevention of leakage of the superabsorbent polymer particles from the front and rear end edges, the cylinder is formed so as to surround the front and back surfaces and both side surfaces of the absorbent body 56. It is preferable that the front and rear edges of the absorbent body 56 are protruded from the front and back of the absorbent body 56, and the protruding portions are crushed in the front and back directions and joined by a joining means such as a hot melt adhesive.

(Exterior sheet)
The exterior sheet 12 has a part constituting the front body F extending from the crotch part to the ventral side and a part constituting the rear body B extending from the crotch part to the back side, and both sides of the front body F As shown in FIG. 8, a waist opening WO for passing the wearer's torso and a pair of left and right leg openings LO for passing the legs are formed. It is what. Reference numeral 12A denotes a joining portion (hereinafter, this portion is also referred to as a side seal portion). The crotch portion means the center in the front-rear direction from the waist edge of the front body F to the waist edge of the back body B in the unfolded state, and the front part and the back part thereof are the front body F and Each back body B is meant.

  The exterior sheet 12 includes a waistline portion T defined as a front-rear direction range extending from the waist opening WO to the upper end of the leg opening LO, and a front-rear direction range of the portion forming the leg opening LO (the side seal portion 12A of the front body F). And an intermediate portion L defined as a front-rear direction region having a side seal portion 12A of the back body B. The waistline T can be divided into a “waist edge” W that conceptually forms the edge of the waist opening, and a “waist lower part” U that is a lower part than this. These lengths in the vertical direction vary depending on the size of the product and can be determined as appropriate. For example, the waist edge W may be 15 to 40 mm, and the waist lower portion U may be 65 to 120 mm. On the other hand, both side edges of the intermediate portion L are bundled along the circumference of the wearer's leg, and this is a portion into which the wearer's leg is put. As a result, the exterior sheet 12 has a substantially hourglass shape as a whole. The degree of tightness of the exterior sheet 12 can be determined as appropriate, and, as shown in FIGS. 1 to 8, the narrowest part may be narrower than the width of the interior body 200 in order to obtain a clean appearance. Although it is preferable, the narrowest part may be determined so as to be equal to or larger than the width of the interior body 200.

  As shown in FIGS. 3 to 5, the exterior sheet 12 is formed by bonding two sheet base materials 12 </ b> S and 12 </ b> H with an adhesive such as a hot melt adhesive, and is located on the inner side. Although the base material 12H extends only to the edge of the waist opening WO, the outer sheet base material 12S wraps around the waist side edge of the inner sheet base material 12H and is folded back to the inside. 12r is extended so that it may coat | cover up to the waist side edge part of the interior body 200. FIG.

The sheet base materials 12S and 12H can be used without particular limitation as long as they are in sheet form, but are preferably non-woven fabrics. The nonwoven fabric is not particularly limited as to what the raw fiber is. For example, synthetic fibers such as olefins such as polyethylene and polypropylene, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers and composite fibers using two or more of them. Etc. can be illustrated. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, a needle punch method, an air through method, and a point bond method. When using a nonwoven fabric, it is preferable that the basic weight shall be about 10-30 g / m < ² >.

Moreover, it is preferable that the total basis weight of the exterior sheet 12 is about 20 to 60 g / m ² so that the design of the printing sheet 25 to be described later can be satisfactorily viewed from the outer surface of the product through the exterior sheet 12. The total light transmittance specified in 7105 is preferably 40% or more, particularly 50% or more.

  The exterior sheet 12 is provided with elongate elastic members 15 to 19 such as thread rubber at a predetermined elongation rate between the sheet bases 12S and 12H in order to improve the fit to the waistline. As the elongated elastic elastic members 15 to 19, synthetic rubber or natural rubber may be used. For bonding the sheet bases 12S and 12H of the exterior sheet 12 and fixing the elongated elastic members 15 to 19 sandwiched therebetween, hot melt bonding or heat sealing or ultrasonic bonding by various coating methods is used. Can do. If the entire exterior sheet 12 is firmly fixed, the texture of the sheet is impaired, which is not preferable. By combining these, it is preferable that the elongated elastic elastic members 15 to 19 are firmly bonded, and other portions are not bonded or bonded weakly.

More specifically, the entire width direction is continuous between the inner surface of the inner sheet base 12H and the outer surface of the folded portion 12r of the outer sheet base 12S at the waist edge W of the rear body B and the front body F. As described above, the plurality of waist edge elastic elastic members 17 are fixed in a state of being spaced apart in the vertical direction and extended along the width direction at a predetermined extension rate. In addition, one or more of the waist edge elastic elastic members 17 disposed in a region adjacent to the waist lower portion U may overlap with the interior body 200 or may be overlapped with the interior body 200 in the width direction. You may each provide in the width direction both sides except a center part. The waist edge elastic elastic member 17 has a thickness of 155 to 1880 dtex, particularly about 470 to 1240 dtex (in the case of synthetic rubber. In the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm ² , particularly 0.1 to the rubber thread of 1.0mm about ^2), 3 to 22 present approximately at intervals of 4 to 12 mm, respectively elongation from 150% to 400%, preferably fixed in particular about 220-320%. Further, the waist edge elastic elastic members 17 need not all have the same thickness and elongation rate. For example, the elastic elastic members may have different thicknesses and elongation rates at the upper and lower portions of the waist edge W. .

  Further, between the outer side surface of the inner sheet base 12H and the inner side surface of the outer sheet base 12S in the lower waist U of the front body F and the rear body B, except for the widthwise central portion overlapping the interior body 200, A plurality of waist lower elastic elastic members 15, 19 made of an elongated elastic elastic member are continuously provided over the entire width direction on each of the upper side and both sides in the width direction, with a predetermined interval in the vertical direction It is fixed in an expanded state along the width direction at an expansion rate.

The waist lower elastic elastic members 15 and 19 have a thickness of 155 to 1880 dtex, especially about 470 to 1240 dtex (in the case of synthetic rubber. In the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm ² , particularly 0.1 to It is preferable to fix the thread rubber of about 1.0 mm ² ) at an interval of 1 to 15 mm, particularly 3 to 8 mm, and about 5 to 30 at an elongation of 200 to 350%, particularly about 240 to 300%.

  Moreover, between the outer side surface of the inner sheet base material 12H and the inner side surface of the outer sheet base material 12S in the intermediate part L of the front body F and the back body B, except for the center part in the width direction overlapping the interior body 200, A plurality of intermediate elastic expansion / contraction members 16 made of an elongated elastic expansion / contraction member are provided in each part on both sides in the width direction so as to be continuous over the entire width direction. It is fixed in a stretched state along the direction.

The intermediate elastic elastic members 16 and 18 have a thickness of 155 to 1880 dtex, particularly about 470 to 1240 dtex (in the case of synthetic rubber. In the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm ² , particularly 0.1 to It is preferable to fix the thread rubber of about 1.0 mm ² ) at an interval of 5 to 40 mm, particularly 5 to 20 mm, and about 2 to 10 at an elongation of 150 to 300%, particularly 180 to 260%.

  As shown in the figure, when the waist lower elastic elastic member and the intermediate elastic elastic members 15, 19, 16, 18 are respectively provided on both sides in the width direction except for the central portion in the width direction overlapping the interior body 200. The interior body 200 does not shrink more than necessary in the width direction, so that it does not look bad or absorbs. In this form, in addition to the form in which the elastic stretchable member exists only on both sides in the width direction, the elastic stretchable member exists from one side of the width direction to the other side across the interior body 200, but overlaps the interior body 200. At the center in the width direction, the elastic expansion / contraction member is finely cut, and the contraction force does not act (substantially equivalent to not providing the elastic expansion / contraction member), and only the both sides in the width direction are configured as the contraction force acting portions. Are also included. Of course, the arrangement of the waist lower elastic members 15, 19, 16, and 18 is not limited to the above example, and the waist lower portion so that the elastic force acts on the entire width of the waist lower U. A part or all of the elastic elastic member and the intermediate elastic elastic members 15, 19, 16, 18 can be provided across the interior body 200 from one side in the width direction to the other side.

  In addition, when the elongated elastic elastic members 15 to 19 of each part cross a printing sheet 25 described later, when rubber containing titanium oxide is used as the elongated elastic elastic members 15 to 19, the content of titanium oxide is It is preferable to use a low one (for example, 2% or less) or one containing no titanium oxide.

(Post-processing tape)
A post-processing tape 70 (fixing means) can be provided at the center in the width direction on the outer surface of the rear body B of the exterior sheet 12. The post-processing tape 70 is for fixing the diaper 100 in a state where the diaper 100 is rolled or folded so that the topsheet 30 is on the inside and the front body F is on the inside. As shown in FIG. 5, in the general post-processing tape 70, a base end portion 71 is fixed to the outer surface of the exterior sheet 12 with an adhesive or the like, and a portion on the front end side of the base end portion 71 is tri-folded. (Folded in a Z-shaped cross section) or folded in half, and the portion between the folded portions is fixed (temporarily fixed) by the temporary fixing adhesive 72 so as to be peelable. Moreover, while having the knob | pick part 73 colored in opaque colors, such as white, in the front-end | tip part, the part except this knob | pick part 73 is transparent or semi-transparent, Through the transparent or semi-transparent part in this post-processing tape 70, A design to be described later is visible from the outer surface side of the post-processing tape 70. Although a specific structure can be appropriately configured, in the illustrated embodiment, the whole is formed by connecting a plurality of transparent or semi-transparent substrates in the longitudinal direction, and a colored tape 74 is bonded to the knob 73. Is adopted.

  At the time of disposal, the diaper 100 is rolled or folded so that the topsheet 30 is on the inside and the front body F is on the inside, and then the folded portion of the post-processing tape 70 is peeled off and spread, and the diaper 100 is rolled or folded. The diaper 100 is fixed with an adhesive so as to be wound from the rear body B of the diaper 100 to the outer surface on the opposite side over the waist opening WO. The post-processing tape 70 is particularly preferably a tri-fold shape that can be folded compactly when not in use and can be expanded into a long shape when in use.

  Fixing means such as the post-processing tape 70 may be provided on the front body F or on both the back body B and the front body F.

(Print sheet)
A printing sheet 25 that is designed by printing is provided between the liquid-impermeable sheet 11 and the exterior sheet 12 (including the interlayer of the exterior sheet 12). The exterior sheet 12 may be omitted, and the print sheet 25 may be exposed on the outer surface. The printed sheet 25 in the illustrated example has a smaller area than the body on which the printed sheet 25 is disposed, and is provided separately for the front body F and the back body B, but passes through the crotch from the front body F. It can also be provided so as to continue to the back body B integrally.

  Although the size and shape of the printing sheet 25 are not particularly limited, it is preferable to sufficiently increase the area in order to make the function sufficient. For example, the width of the printing sheet 25 is 50 to 120 of the width of the absorber 56. The length of the printing sheet 25 is preferably about 15 to 30% of the total length Y of the article on at least one side of the stomach side and the back side. Further, the shape of the print sheet 25 is preferably a rectangle as shown in the figure in that trim loss does not occur. However, the print sheet 25 has a geometric shape such as a circle, an ellipse, a triangle, a hexagon, or a shape along the periphery of the design. You may cut it.

As the sheet base material of the printing sheet 25, a plastic film, non-woven fabric, paper, or the like can be used, but a bulky material having high air permeability is preferable. When using a plastic film, it is desirable to have moisture permeability in order to prevent stuffiness. Nonwoven fabrics and paper are preferable because they have moisture permeability, and when performing design printing, it is preferable to use nonwoven fabrics that are smooth and easy to print, and papers that are high in strength and difficult to bleed ink. Particularly preferred are basis weight 15 to 35 g / m ² approximately, crepe paper having a thickness of about 0.1 to 0.3 mm (thin paper) and a basis weight 10 to 25 g / m ² approximately, a thickness of about 0.1 to 0.3 mm Non-woven fabrics (especially spunbond nonwoven fabrics and SMS nonwoven fabrics having a spunbond portion having a fineness of about 1.0 to 3.0 dtex). When crepe paper is used, the crepe rate is preferably about 5 to 20%, particularly about 5 to 15%. If the crepe rate is 20% or more, the amount of ink fixed increases, but blurring occurs and is not suitable for design printing. If the crepe rate is 5% or less, the amount of fixing is small because the ink hardly penetrates.

(Exterior sheet split structure)
In the above-described example, the front body F to the back body B are continuously covered with the integral exterior sheet 12, but the exterior sheet covers the stomach side of the wearer's waist and the back side The front end portion of the interior body is connected to the inner surface of the center portion in the width direction of the abdominal side exterior sheet with a hot melt adhesive or the like, and the center portion in the width direction of the back side exterior sheet. The rear end of the interior body is connected to the inner surface by a hot melt adhesive or the like, and the form in which the abdominal exterior sheet and the back exterior sheet are not continuous on the crotch side and are separated from each other may be adopted. it can. This separation distance can be about 150 to 250 mm. In this case, the back surface of the liquid-impermeable sheet in the interior body is crotch so as to cover the entire back surface of the interior body, or to cover the entire portion exposed between the abdominal exterior sheet and the back exterior sheet. A partial exterior sheet can also be fixed. As the crotch outer sheet, the same material as that used for the outer sheet described above can be used.

(Odor generating means)
Characteristically, as shown in FIGS. 3 to 6, an alkaline substance 80 that dissolves in urine and makes the urine alkaline by the surface sheet 30 side from the liquid-impermeable sheet 11, and the core material is a fragrance and a membrane material Contains microcapsules 90 that are soluble in urine that have been made alkaline by the alkaline substance 80. The urine excreted from the wearer becomes alkaline due to dissolution of the built-in alkaline substance 80 on the surface sheet 30 side from the liquid-impermeable sheet 11, and comes into contact with the microcapsule 90 to dissolve the membrane material. As a result, the fragrance | flavor currently hold | maintained in the microcapsule 90 discharge | releases, a fragrance diffuses out of a diaper, and the person other than a wearer can know the presence or absence of excretion by sniffing the fragrance. Therefore, since the membrane material is not dissolved by supplying moisture directly to the microcapsule 90, a situation occurs in which the fragrance is released due to moisture in storage before use or sweat of the wearer during wearing. It becomes difficult to do.

  The locations of the alkaline substance 80 and the microcapsule 90 are not particularly limited as long as the alkaline substance 80 is dissolved in urine and the urine dissolves the membrane material of the microcapsule 90, but the alkaline substance 80 and the microcapsule 90 are not limited. If the urine in which the material and the fragrance are dissolved or mixed leaks out from the surface sheet 30 and adheres to the skin of the wearer, the skin may be rough. Therefore, as shown in FIG. 9 and FIG. 10, the alkaline substance 80 and the microcapsule 90 are provided only in the thickness direction range from the bottom of the absorber 56 to the surface of the liquid-impermeable sheet 11, It is desirable that the urine in which 80 or the like is dissolved is less likely to return to the surface sheet 30 side than the absorber 56 by the absorber 56.

  The alkaline substance 80 and the microcapsule 90 may be located at the same position in the thickness direction, or any of them may be located on the liquid-impermeable sheet 11 side, but the contact efficiency between urine and the alkaline substance 80 and the alkali In order to increase both the contact efficiency between the urine in which the substance 80 is dissolved and the microcapsule 90 and to generate aroma more efficiently, the alkaline substance 80 is added to the microcapsule as shown in various forms in FIGS. It is preferably contained on the surface sheet 30 side than 90. In particular, in the form in which the absorbent body 56 is wrapped by a packaging sheet 58 made of non-woven fabric or crepe paper, as shown in various forms in FIGS. 9 and 10, the portion located on the lower side of the absorbent body 56 in the packaging sheet 58. When the microcapsule 90 is contained in the surface of the liquid-impermeable sheet 11 on the side of the packaging sheet 58, the alkaline substance 80 and the microcapsule are added to the packaging sheet 58 and the liquid-impermeable sheet 11. Since it can manufacture only by apply | coating 90 each, there exists an advantage that manufacture is easy.

  In the sheet such as the packaging sheet 58 and the liquid-impermeable sheet 11, the alkaline substance 80 and the microcapsule 90 are contained on the surface of the sheet in addition to the form in which the alkaline substance 80 and the microcapsule 90 are held inside the sheet. It includes the form which is made. In the various forms shown in FIG. 9, the alkaline substance 80 is held inside the packaging sheet 58, and the microcapsules 90 are held on the surface of the liquid-impermeable sheet 11 on the packaging sheet 58 side. The form is such that the alkaline substance 80 is held on the surface of the packaging sheet 58 and the microcapsule 90 is held on the surface of the liquid-impermeable sheet 11 on the packaging sheet 58 side.

  For example, in the case of a liquid-permeable porous material such as crepe paper or nonwoven fabric, it is obtained by mixing and dispersing a coating solution or microcapsule 90 obtained by dissolving the alkaline substance 80 in a solvent such as water in a dispersion medium such as water. By applying the coating solution, the alkali substance 80 or the microcapsule 90 can be introduced into the fiber gap of the sheet, and the portion of the sheet can be made into a layer containing the alkali substance 80. In the case of a resin sheet or film such as the liquid-impermeable sheet 11, a water-soluble paint mixed with the alkaline substance 80 and the microcapsule 90 is applied to form a water-soluble coating film on the surface of the sheet, By adhering the alkaline substance 80 or the microcapsule 90 to the surface using a water-soluble adhesive, the alkaline substance 80 or the microcapsule 90 can be attached to the surface of the sheet, not inside the sheet. .

  In particular, the various forms of FIG. 9 and the form of FIG. 10A are preferable because the contact efficiency of urine, the alkaline substance 80, and the microcapsule 90 is good. However, as shown in FIG. A form in which the alkaline substance 80 is held on the inner surface (the surface on the absorber 56 side), or the inner and outer surfaces (the surface on the absorber 56 side and the liquid-impermeable sheet 11) of the packaging sheet 58, as shown in FIG. A form in which the alkaline substance 80 is held on the side surface) is also preferable.

  The alkaline substance 80 and the microcapsule 90 may have the same position or may be shifted in a plan view. However, as in various forms shown in FIGS. If the containing portion of the microcapsule 90 is provided only inside the peripheral portion of the containing portion of the alkaline substance 80, the contact efficiency between the urine and the alkaline substance 80 is increased, and the urine and microbe in which the alkaline substance 80 is dissolved. The contact efficiency with the capsule 90 is also increased, which is preferable.

  9 (b) and FIG. 9 (c), at least one (particularly the alkaline substance 80) of the alkaline substance 80 and the portion containing the microcapsule 90 does not hinder breathability, urine permeability and diffusibility. As shown in Fig. 2, vertical stripe patterns (patterns in which stripes or strips along the front-rear direction are provided in multiple rows at intervals in the width direction) or horizontal stripe patterns (stripes or strips along the width direction) Are included in a pattern in which a plurality of portions are provided in the front-rear direction at intervals, or a dot-like pattern (dot-like or spotted-containing portions are spaced in the width direction and the front-rear direction, staggered) It is preferable to provide a regular pattern or a pattern in which a large number of irregular patterns are provided.

The part containing the alkaline substance 80 and the microcapsule 90 may be only a part in the front-rear direction, such as only the crotch part, but in order to increase the probability of contact with urine, at least the whole part in the front-rear direction of the part having the absorber 56 It is preferable to do this. Further, in general, disposable diapers have a large amount of urine supplied to the crotch, and the amount of urine supplied to both the front and rear sides of the crotch is small. Thus, the keep front portion and a rear portion of the crotch portion the less the amount of dissolution of the luer alkali substance 80 against urine, dissolution of the film material of the microcapsule 90, which may in turn generate the aroma becomes insufficient . Therefore, as shown in FIG. 6, when the alkali substance 80 is contained in the crotch part and its front part and rear part, respectively, from the basis weight of the alkali substance 81 in the crotch part (content g / m ² per unit area) It is preferable to increase the basis weight of the alkaline substance 82 in the front part and the rear part.

The alkaline substance 80 is not particularly limited as long as it dissolves in urine and raises the pH of urine to the dissolution conditions of the membrane material of the microcapsule 90. However, it is preferable to adjust the pH to about 11-12. Examples of substances include sodium carbonate and calcium hydroxide. The content of the alkaline substance 80 can be determined as appropriate, but in a normal case, it can be about 0.5 to 3.0 g per diaper, and the basis weight can be about 20 to 125 g / m ^2. it can.

  Although the fragrance | flavor which is a core material of the microcapsule 90 is not specifically limited, For example, fragrance | flavors, such as rose, lavender, mint, and lemon, are preferable. The fragrance is preferably a natural extract, but may be a synthetic product. Also, in terms of function, the perfume component has a masking effect that makes it impossible to recognize the urine and stool odor even if it has a deodorizing effect that eliminates the urine and stool odor. Also good. Furthermore, a colorant can be added to the core material of the microcapsule 90. In this case, not only the odor is generated, but also functions as an indicator by a color change seen from the outer surface.

  The membrane material of the microcapsule 90 is not particularly limited as long as it is an alkali-soluble material that dissolves in the urine in which the alkaline substance 80 is dissolved. For example, the membrane material is soluble in the temperature range of 20 to 80 ° C. and in the alkaline region of pH 11 to 14. A thing can be used suitably. Examples of the film material of the microcapsule 90 include a film material “a hydrophilic colloid having a carboxyl group cured by a compound having an oxazoline group” described in JP-A-2007-00756. The alkali-soluble microcapsule 90 is soluble in a pH range of 11 to 14 at a predetermined temperature of 20 to 80 ° C., and the pH range and the predetermined temperature indicate a hydrophilic colloid having a carboxyl group to be used ( It can be determined by selecting the basic film substance). The details of the film material will be described with reference to the description in Japanese Patent Application Laid-Open No. 2007-00756.

(Microcapsule production method)
The alkali-soluble film material can be obtained by curing a hydrophilic colloid having a carboxyl group with a compound having an oxazoline group. Here, the hydrophilic colloid indicates a molecular colloid or the like that exists in a solvent and can be coordinated around a core substance to form an emulsion.

  For example, hydrophilic colloids having a carboxyl group (hereinafter sometimes referred to as basic film substances) include water-soluble proteins such as gelatin and albumin, natural polymer substances such as starch, agar, and gum arabic, carboxymethylcellulose, and carboxymethyl. Synthetic cellulose ethers such as hydroxyethyl cellulose, synthetic polymer compounds such as polyvinyl methyl ether / maleic anhydride copolymer, carboxyl group-modified polyvinyl alcohol, and the like are used. Can do. Among them, a water-soluble protein having gelling property is preferable for use as a basic film substance. Further, gelatins such as alkali-treated gelatin and acid-treated gelatin are preferable, and among them, alkali-treated gelatin is most suitable. Gelatin has no toxicity and is suitable for edible and oral use.

  Gelatin is roughly classified into acid-treated gelatin and alkali-treated gelatin according to the difference in the treatment method when extracting from collagen. Alkali-treated gelatin undergoes deamidation of amino acid side chains in the calcination treatment step, and has a higher amount of modification to carboxyl groups than acid-treated gelatin. Since the oxazoline group has high activity with respect to the reaction with the carboxyl group, alkali-treated gelatin having many carboxyl groups is suitable as a cross-linking material by the oxazoline compound.

  An example of a production method using a complex coacervation method of a microcapsule having an alkali-soluble membrane material will be described according to the order of the production steps as follows. Of course, it goes without saying that other methods can be used as a method for producing the microcapsules.

  First, a core material (oil-based substance) is dispersed in an aqueous solution containing a carboxyl group-containing hydrophilic colloid, that is, a basic film material, thereby forming an O / W emulsion in which oil droplets are dispersed in the aqueous solution. The core material used is at least a fragrance, and a colorant or the like can be added to the core material.

  As the hydrophilic colloid (basic film substance) having a carboxyl group, a gelable hydrophilic colloid having an isoionic point as a polycation is used, and a water-soluble protein is generally used. More specifically, gelatin, agar, casein, soybean protein, collagen, albumin and the like can be mentioned. Of these, gelatin such as acid-treated gelatin and alkali-treated gelatin is preferred, and alkali-treated gelatin is most preferred.

  In order to disperse the core substance in the aqueous solution containing the basic film substance, a method such as stirring and ultrasonic irradiation can be used by adding the core substance to the aqueous solution. The concentrations of the core substance and the film substance are arbitrarily selected depending on the properties and shapes required for the target microcapsules. Further, the size of the core material droplet obtained by the dispersion is related to the size of the microcapsule finally obtained. The size of the microcapsules is selected according to the purpose, and the size of the droplets of the emulsion is substantially reflected as the particle size of the microcapsules. The final size of the microcapsules is specifically, oil droplets corresponding to a sphere equivalent diameter of generally 0.1 to 3000 μm, preferably 0.1 to 2000 μm, more preferably 0.1 to 1000 μm. Disperse as follows.

  Subsequently, a polyanion is mixed into the obtained O / W emulsion to make it uniform, and then the pH is acidified to form a coacervate film.

  The polyanion to be used is selected as necessary, and specific examples include gum arabic, sodium carboxymethylcellulose, sodium alginate, sodium polyvinylbenzenesulfonate, polyvinylmethylether / maleic anhydride copolymer, and the like. Of these, gum arabic and sodium carboxymethyl cellulose are preferably used.

  After mixing the polyanions, the pH of the emulsion is adjusted to acidic, for example, pH = 3-5, preferably 4-5. The acid used at this time is preferably selected from those that do not impair the properties of the core material and the coating material, and those that do not inhibit the curing reaction. In general, organic acids such as acetic acid, citric acid, succinic acid, oxalic acid, lactic acid and salicylic acid, and inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid are used.

  The emulsion on which the coacervate film is formed is subsequently cooled in order to gel the film. Usually, the emulsion is cooled to 5 to 25 ° C., preferably 5 to 10 ° C. to gel the film.

  In order to cure the gelled film, a curing agent is subsequently mixed into the emulsion. Although it can be cured with aldehydes such as formaldehyde and glutaraldehyde which are conventionally known, they cannot be alkali-soluble and cannot be used from the viewpoint of toxicity and environmental considerations.

  Therefore, a compound having an oxazoline group is used as a curing agent. Such a so-called oxazoline compound is a compound having an oxazoline group as shown in (Chemical Formula 1). For example, 2,2′-bis- (2-oxazoline), 2,2′-methylene-bis- ( 2-oxazoline), 2,2′-ethylene-bis- (2-oxazoline), 2,2′-trimethylene-bis- (2-oxazoline), 2,2′-tetramethylene-bis- (2-oxazoline) 2,2′-hexamethylene-bis- (2-oxazoline), 2,2′-octamethylene-bis- (2-oxazoline), 2,2′-ethylene-bis- (4,4′-dimethyl-) 2-oxazoline), 2,2'-p-phenylene-bis- (2-oxazoline), 2,2'-m-phenylene-bis- (2-oxazoline), 2,2'-m-phenylene-bis- (4 4'-dimethyl-2-oxazoline), bis - (2-oxazolinyl sulfonyl cyclohexane) sulfide, bis - (2-oxazolinyl sulfonyl norbornane) oxazoline compounds such as sulfides. Further, as addition polymerizable oxazoline compounds, 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2 -Isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline and the like. Those obtained by polymerizing or copolymerizing one or more of these compounds can be used.

  Further, the compound and (meth) acrylic acid esters such as methyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate; unsaturated nitriles such as (meth) acrylonitrile; Unsaturated amides such as meth) acrylamide and N-methylol (meth) acrylamide; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; Halogenated α, β-unsaturated monomers such as vinyl chloride, vinylidene chloride and vinyl fluoride; copolymers of α, β-unsaturated aromatic monomers such as styrene and α-methylstyrene Can also be used.

  Examples of such compounds include oxazoline compounds described in JP-A-5-25361, JP-A-11-231447, and the like.

  Specific examples of commercially available products include Epocross WS-500, Epocross WS-700, Epocross K-1010E, Epocross K-1020E, Epocross K-1030E, Epocross K-2010E, Epocross K-2020E, Epocross K-2030E. , Epocross RPS-1005, Epocross RAS-1005 (all manufactured by Nippon Shokubai Co., Ltd.), NK Linker FX (Shin Nakamura Chemical Co., Ltd.) and the like.

（式中、Ｒ１、Ｒ２、Ｒ３、Ｒ４、はそれぞれ独立に水素、ハロゲン、アルキル、アラルキル、フェニルまたは置換フェニルを表し、Ｒ５は付加重合性不飽和結合を持つ非環状有機基を表す。）

(Wherein R1, R2, R3, and R4 each independently represent hydrogen, halogen, alkyl, aralkyl, phenyl, or substituted phenyl, and R5 represents an acyclic organic group having an addition polymerizable unsaturated bond.)

  The compound having an oxazoline group is preferably a polymer compound. Here, the polymer compound means a compound having a number average molecular weight of 10,000 or more. Further, when the polymer compound has film-forming properties, effects such as further improvement of the strength of the microcapsule film and improvement of the holding ability of the inclusions can be obtained. This is presumed to be because the curing agent itself has film-forming properties, so that the coating substance is cured, and at the same time, a double coating is formed by the curing agent itself, thereby strengthening the microcapsule film. Here, the film forming property means having a film-like film forming property when a solution of a polymer compound having an oxazoline group alone is applied and evaporated to dryness. In addition to further improving the strength of the capsule film, it is possible to obtain favorable effects such as improvement in sealing performance, flexibility and flexibility. However, when alkali solubilization is concerned, there are concerns about the lack of quick response, and caution is required. When it is desired to obtain a so-called sustained-release microcapsule that does not immediately solubilize but dissolves gradually, it can be used as an effective method.

  After the coating is cured in this way, the desired microcapsules can be obtained by operations such as filtration, decantation, dehydration, liquid separation, and drying as necessary.

  In addition to the above components, the composition of the microcapsule contains a third component in a range that does not adversely affect the performance of the microcapsule, such as not inhibiting the curing by the oxazoline group compound, or to give a special effect. You can also For example, when an onium salt such as diammonium hydrogen phosphate is blended, it may act as a curing catalyst.

  When an uncured gel film is subjected to a curing reaction in an aqueous solution, it is problematic to set the treatment temperature to be equal to or higher than the gel point of the basic film material. This is because a gel film that does not have heat resistance before curing readily dissolves in water at a temperature above its gel point. In addition, there is a problem that the microcapsules tend to aggregate at a temperature near the gel point. In particular, it is very difficult to dispose the basic film material at an arbitrary position and shape with respect to the periphery of the core material (encapsulated material) like a microcapsule and to desire curing while maintaining the state. For example, the general gel point of an aqueous gelatin solution, which is a kind of basic film material, is around 25 ° C.

  Curing with the oxazoline compound in the complex coacervation method needs to be performed after separating the uncured basic film substance (gelatin) microcapsule from the adjustment liquid and washing the microcapsule several times with water. If such an operation is not performed, sufficient curing cannot be achieved. This is because when microcapsules are prepared by the complex coacervation method, polyanions necessary for coacervation and undeposited (dissolved) basic coating substance (gelatin) molecules are present in the aqueous solution in which the microcapsules are dispersed. Is considered to exist. As the polyanion, a compound having a carboxyl group (such as gum arabic or carboxymethyl cellulose) is generally used. In addition, the basic film substance (gelatin) molecule naturally has a carboxyl group.

That is, in the microcapsule dispersion in this state, as a carboxyl group-containing component that can react with the oxazoline group,
a) Basic film substance molecules in dissolved state (gelatin, etc.)
b) Dissolved polyanion molecules (gum arabic, carboxymethyl cellulose, etc.)
c) Dispersed basic film material gel (gelatin gel, etc.)
Can be said to exist. This is because it is presumed that it is necessary to remove dissolved a) and b) in order to efficiently react the dispersed basic film substance (gelatin gel) with the oxazoline compound.

  The oxazoline compound reacts with all the hydrophilic colloids having a carboxyl group to give microcapsules having a cured film. As the hydrophilic colloid having a carboxyl group, a water-soluble protein is preferable, and gelatin is particularly preferable. In particular, those having a pI (isoionic point) of 4.9 to 8.1 are desirable, and alkali-treated gelatin is more preferred. This is because gelatin in this range and type is likely to be a mononuclear microcapsule and contributes to the quick response to alkali solubilization.

  The measured value of pI was a value obtained by treating an aqueous gelatin solution with an ion exchange resin and then measuring the pH of the aqueous gelatin solution at 35 ° C., but other commonly used pI (isoionic point) is used. ) Measurements and equivalents can also be used. The oxazoline compound forms a hardened film on gelatin in general, and a suitable microcapsule can be obtained. However, a microcapsule using gelatin whose pI exceeds 8.1 (for example, acid-treated gelatin) is allowed to stand after hardening. When stored over time in the (rt) state, the microcapsules tend to aggregate together, making redispersion difficult. pI represents an isoionic point of gelatin or the like, which can be said to indicate the amount of carboxyl groups and amino groups of the basic film substance (gelatin) molecules. Gelatin with a low pI indicates that the acid amide bond of the amino acid side chain is decreased by deamidation and the carboxyl group is increased. Since the oxazoline group reacts with the carboxyl group, it is considered that as the amount of the carboxyl group increases, the number of crosslinking points by the basic film substance (gelatin) and the oxazoline compound increases. That is, sufficient crosslinking can be secured, and it is presumed that stable microcapsules can be easily obtained over time. As described above, when the pI value is 4.9 to 8.1, it is easy to form a mononuclear microcapsule without aggregation.

  The reaction between the oxazoline compound and the basic film material is r. t. Progress even under conditions. However, as in general organic reactions, it is desirable to advance the reaction by heating as much as possible. For this reason, it is possible to secure the reaction temperature and to perform a desired treatment in a shorter time by using a basic film substance having a gel point as high as possible.

  In addition, although this example demonstrated by the complex coacervation method, it can manufacture also by other microcapsule manufacturing methods, such as a simple coacervation method and an orifice method.

  The present invention can be used for various disposable diapers such as a tape type and a pad type as well as a pants-type disposable diaper as in the above example.

  DESCRIPTION OF SYMBOLS 11 ... Liquid impervious sheet, 12 ... Exterior sheet, 12r ... Folded part, 25 ... Print sheet, 200 ... Interior body, 30 ... Top sheet, 40 ... Intermediate sheet, 50 ... Absorbing element, 56 ... Absorber, 58 ... Packaging sheet, 60 ... side barrier cuff, 62 ... barrier sheet.

Claims (6)

In a disposable diaper comprising a liquid-permeable surface sheet, a liquid-impermeable sheet, and an absorbent body interposed therebetween,
An alkaline substance that dissolves in urine to make the urine alkaline, and a microcapsule that is soluble in urine in which the core material is a fragrance and the membrane material is made alkaline by the alkaline substance from the liquid-impermeable sheet. Including on the seat side,
A disposable diaper characterized by that.   The disposable diaper of Claim 1 which contains the said alkaline substance and the said microcapsule only in the thickness direction range from the bottom part of the said absorber to the surface of the said liquid-impermeable sheet. While containing the alkaline substance on the surface sheet side than the microcapsule,
3. The disposable diaper according to claim 2, wherein the microcapsule-containing portion is provided only inside a peripheral portion of the alkaline substance-containing portion in a plan view. The absorbent body is wrapped by a packaging sheet made of nonwoven fabric or crepe paper,
4. The method according to claim 1, wherein the alkaline substance is contained in a portion of the packaging sheet located below the absorber, and the microcapsule is contained on the packaging sheet side surface of the liquid-impermeable sheet. The disposable diaper described in the item.   The alkaline substance is contained in the crotch part and the front part and the rear part thereof, respectively, and the basis weight of the alkaline substance in the front part and the rear part is greater than the basis weight of the alkaline substance in the crotch part. The disposable diaper of any one of 4. The alkaline substance is a substance that dissolves in the urine to bring the pH of the urine to 11-12, and the membrane material of the microcapsule is soluble in the temperature range of 20-80 ° C. and in the alkaline region of pH 11-14. The disposable diaper of any one of Claims 1-5 which is a thing.

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