JP2006341020A - Absorbent article and producing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absorbent article which can visually tell the appropriate timing of replacement. <P>SOLUTION: This absorbent article includes coating films of a hydrophilic hot-melt composition, which make a visual change when coming in contact with moisture and spot between an absorbent body and a leak-prevention sheet, having a space of 1 to 100 mm between the edges of each neighboring film. It is preferable that the gross area of such films should account for no more than 50 percent of the total area of the absorbent body. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an absorbent article having a function of visually changing when it comes into contact with moisture, and a method for producing the same.

  As an absorbent article with the ability to identify the presence or absence of excretion of urine etc. from the outside, the leakproof sheet can be printed with water-soluble ink or ink that diffuses and elutes when wet, or the top surface of the pattern sheet Ink is applied to the ink, and the ink comes into contact with moisture to become transparent, so that the pattern emerges, or the pH changes between the absorbent main body (absorbent core) and the leak-proof sheet. Absorbent articles coated with a hot melt that changes color have been proposed (see Patent Documents 1 to 3).

  By the way, the absorbent articles that have been proposed so far have a large visual change even when the amount of absorbed liquid is small, and even though there is still sufficient absorption capacity, it is decided to replace it. It has a problem of misleading the replacement timing.

Japanese Utility Model Publication No.59-123110 Japanese Patent Laid-Open No. 10-75980 JP-A-2005-21390

  This invention is made | formed in view of the said subject, and it aims at providing the absorbent article which can make an appropriate replacement timing judge by visual recognition, and its manufacturing method.

  The present invention is an absorbent article in which a coating film of a hydrophilic hot melt composition that visually changes when it comes into contact with moisture is scattered between an absorbent main body and a leak-proof sheet. The above object is achieved by providing an absorbent article to which the hot melt composition is applied so that the interval between the outer edge portions of the adjacent coating films is 1 to 100 mm.

  The present invention also relates to a method for producing an absorbent article according to the present invention, wherein the absorption device uses a coating apparatus that coats a fluid in the form of a coating from the inside of a roll coater that rotates uniaxially, onto the surface of the workpiece. The manufacturing method of the absorbent article which coats the hydrophilic hot-melt composition which changes visually when it contacts with moisture so that it may be located between an adhesive main body and the said leak-proof sheet | seat is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the absorbent article which can make an appropriate replacement timing judge by visual recognition, and its manufacturing method are provided.

  Hereinafter, the present invention will be described based on preferred embodiments thereof.

1 to 3 schematically show a first embodiment of the absorbent article of the present invention.
As shown in FIG. 1, the absorbent article 1 of this embodiment has a form of a pants-type disposable diaper. As shown in the developed perspective view of FIG. 2, the absorbent article 1 in the present embodiment has a back side portion 1 </ b> A disposed on the back side of the wearer when worn, a ventral side portion 1 </ b> B disposed on the ventral side, and both. It has a crotch portion 1C that is positioned between the crotch of the wearer and that has a vertically long shape with a central portion in the longitudinal direction constricted.

  The absorbent article 1 includes a top sheet 11, a leak-proof sheet 12, and an absorbent body 13 disposed between the sheets 11 and 12, and an absorbent main body (absorbent core) 13a covered with nonwoven fabrics 13b and 13c. A leg cover nonwoven fabric sheet 14 disposed on the outer side (lower side in the drawing) of the sheet 12 and an outer layer nonwoven fabric sheet 15 disposed on the outer side of the leg cover nonwoven fabric sheet 14 are provided.

  The absorbent article 1 has a coating film 2 of a hydrophilic hot melt composition that visually changes between the absorbent main body 13a and the leak-proof sheet 12 when it comes into contact with moisture, on the crotch 1C of the absorbent main body 13a. It is arranged so as to be distributed substantially evenly in the part. Examples of the form of the coating include dots, patterns, letters, or a combination of these. In the case of letters, it is possible to communicate even if the user is unable to interact by using the wording form. In this case, it is possible to give the exchange person a good feeling about the exchange work.

  The hot melt composition is applied and formed so that the interval between the outer edge portions of the adjacent coating films 2 is 1 to 100 mm, preferably 5 to 50 mm. When the interval between the outer edge portions of the coating film 2 is within such a range, the coating film is arranged so as to be scattered at a predetermined interval. Therefore, in addition to the presence or absence of absorption of body fluid such as urine, the spread due to absorption Therefore, the amount of absorption can be estimated, so that it can be exchanged without error in timing. When the coating film 2 is in the form of characters, the distance between the outer edges of the characters is provided in the above range.

  The total area of the coating film 2 with respect to the area of the absorbent main body 13a is preferably 50% or less and more preferably 40% or less in consideration of the humidity in the diaper when the diaper is worn. The total area of the coating film is preferably as small as possible with respect to the area of the absorbent main body 13a. However, considering the ease of visually recognizing the extent of water absorption, the lower limit is practically about 1%.

The area of each coating film 2 is preferably 0.000001 to 0.002 m ^{2 and} more preferably 0.000001 to 0.001 m ^{2 in} consideration of the humidity in the diaper when the diaper is worn.

  The hydrophilic hot-melt composition constituting the coating film 2 contains a hydrophilic composition containing an acidic compound and a color change indicator whose color changes with a change in pH, and an alkali in the leak-proof sheet 12 described later. When the component and water come into contact with each other, and the contacted water comes into contact with the hydrophilic composition, the pH of the hydrophilic composition becomes higher than 4 and the color of the hydrophilic composition changes. .

  The surface sheet 11 may be made of a material conventionally used for disposable diapers such as a hydrophilic nonwoven fabric or an apertured film.

  The leak-proof sheet 12 is formed from a moisture-permeable resin sheet containing an alkali component. The leak-proof sheet 12 is preferably a porous sheet obtained by melting and kneading a hydrophobic thermoplastic resin containing the alkali component to form a sheet, and uniaxially or biaxially stretching the sheet. As the alkali component, calcium carbonate, magnesium carbonate, barium carbonate, sodium carbonate and the like can be used, and examples of the organic component include sodium oleate, sodium acetate, barium acetate and magnesium stearate.

From the viewpoint of moisture permeability of the barrier sheet 12 can be performed quickly a change in pH, is preferably ^{0.1~6.0g / (100cm 2 · h)} , 2.0g / (100cm 2 · h) or more is more preferable. Here, the water vapor transmission rate of the leak-proof sheet 12 is measured by the moisture absorption amount when the sample is stored at 30 ° C./90% RH for one hour in accordance with JIS Z0208 (cup method).

The absorbent body 13 has a rectangular outer shape, and an absorbent main body (absorbent core) 13a is covered with nonwoven fabrics 13b and 13c. Examples of the nonwoven fabrics 13b and 13c include hydrophilic nonwoven fabrics obtained by hydrophilizing the nonwoven fabric. Considering the points of performing the change of the pH quickly, basis weight is preferably ^{10~40g / m 2, 15~25g / m} 2 is more preferable.

  For the absorbent main body 13a, an absorbent polymer, pulp, or a mixture thereof conventionally used for the absorbent main body is used.

  Acidic compounds contained in the hydrophilic hot melt composition include vinyl acetate homopolymer, polyethylene / polyvinyl acetate copolymer, polyethylene / polyacrylic acid copolymer, stearic acid, oleic acid, rosin acid, L-ascorbic acid, nicotine. An acid, L-glutamic acid, lactic acid or succinic acid, or a combination of two or more of these may be mentioned. These acidic compounds are preferably 50 to 99.99% by weight, more preferably 60 to 99.99% by weight, more preferably 60 to 60% by weight based on the total amount of the acidic compound and the color indicator in the hydrophilic composition. 99% by weight is contained. If the amount of the acidic compound is less than 50% by weight, it is difficult to keep the pH at 4 or less, and the color may be changed only by contact with water.

  The color change indicator contained in the hydrophilic composition is one that changes its color at a pH of 3 to 7, and examples thereof include bromophenol blue, methyl orange, alizarin S, bromocresol green, methyl red, Although bromocresol purple etc. are mentioned, it is not limited to these. Particularly preferred among these color indicators are bromophenol blue, bromocresol green, bromocresol purple, and the like. These color indicators are preferably 0.01 to 50% by weight, more preferably 0.01 to 40% by weight, and still more preferably 0.8% by weight based on the total amount of the acidic compound and the color indicator in the hydrophilic composition. It is contained in an amount of 01 to 1% by weight, most preferably 0.01 to 0.5% by weight. When the amount of the color indicator is within such a range, the color before the color change of the hydrophilic composition is not too dark, and the color changes sufficiently to be visible from the outside. Moreover, it is preferable also in terms of cost.

  The hydrophilic hot melt composition contains a hydrophilic polymer having tackiness in addition to the acidic compound and the color indicator, and the hydrophilic hot melt composition is given adhesiveness as described above. Furthermore, the leak-proof sheet 12 and the nonwoven fabric 13c are more firmly fixed. As will be described later, this hydrophilic hot melt composition is applied in the form of the coating film 2 by using a hot melt coating apparatus equipped with a uniaxially rotating roll coater.

  The hydrophilic polymer is not particularly limited as long as it has adhesiveness and is hydrophilic, and examples thereof include vinylpyrrolidone homopolymer, polyamide, polyvinyl alcohol, or combinations of two or more thereof. Among these hydrophilic polymers, vinyl pyrrolidone homopolymer, polyvinyl alcohol, or a combination thereof is particularly preferable. These hydrophilic polymers preferably have a number average molecular weight of 500 to 30,000, preferably 1,000 to 10,000, in view of imparting appropriate hot melt adhesiveness to the hydrophilic composition. More preferably it is. These hydrophilic polymers are preferably contained in an amount of 20 to 50% by weight, more preferably 30 to 40% by weight, based on the total amount of the hydrophilic composition. When the amount of the hydrophilic polymer is within such a range, water is easily taken into the hydrophilic composition and discoloration is likely to occur. In addition, it is easy to keep the pH at more than 4 by suppressing a relative decrease in the compounding amount of the acidic compound, and it may be discolored only by contact with water. . That is, when the hydrophilic composition contains the acidic compound, the color indicator, and the hydrophilic polymer, the preferred composition is 25 to 79.99% by weight of the acidic compound and 0.01 to 25% by weight of the color indicator. Further, the hydrophilic polymer is 20 to 50% by weight, and more preferable blends are 30 to 69.99% by weight of the acidic compound, 0.01 to 30% by weight of the color indicator, and 30 to 40% by weight of the hydrophilic polymer.

  Moreover, the said hydrophilic composition may contain antioxidant, the ultraviolet absorber, etc. in addition to the component mentioned above. These components are preferably contained in an amount of 0.5 to 5% by weight, more preferably 0.5 to 3% by weight, based on the total amount of the hydrophilic composition.

The hydrophilic composition can be prepared by stirring and mixing each component at, for example, about 150 ° C. for about 60 minutes. The hydrophilic composition thus adjusted can be fixed to the leak-proof sheet 12 by being melted and applied at 90 ° C. to 110 ° C., for example. The basis weight of the hydrophilic composition, it is preferable to ^{10g / m 2 ~30g / m 2} .

  Between the leg cover nonwoven fabric 14 and the outer layer nonwoven fabric 15 located on the back side portion 1A and the ventral side portion 1B, an elastic member 16 for forming waist gathers and an elastic member 17 for forming waistline gathers are disposed, By contraction of these elastic members, a waistline gather and a waist gather are formed. In addition, an elastic member 18 for forming leg gathers is disposed between the leg cover nonwoven fabric sheet 14 and the outer layer nonwoven fabric sheet 15 located on both side edges of the crotch 1C so as to follow the constriction. The member 18 contracts, and leg gathers are formed at portions disposed around the legs when worn. As these leg cover nonwoven fabric sheet 14, outer layer nonwoven fabric sheet 15, and elastic members 16, 17, and 18, known ones that have been conventionally used for disposable diapers are used within a range that does not impair the effects of the hot melt composition. Is done.

  Since the absorbent article 1 of this embodiment is arranged so that the coating film of a predetermined form is scattered at a predetermined interval between the leak-proof sheet 12 and the nonwoven fabric 13b as described above, urine In addition to the presence or absence of absorption of body fluids such as, the amount of absorption can be estimated by the spread due to absorption, so that it can be exchanged without error in timing.

  Moreover, by making the form of the coating film 2 into the wording and design by a character, for example, communication with the user who cannot interact can be aimed at, or it can give a favorable impression to exchange work.

  Moreover, since the coating film 2 is scattered uniformly, the moisture permeability of the leak-proof sheet 12 is not lowered.

  4 and 5 show a second embodiment of the absorbent article of the present invention. In the absorbent article of this embodiment, the same code | symbol is attached | subjected about the part which is common in the absorbent article of 1st Embodiment. In the absorbent article of the present embodiment, the description in the first embodiment is appropriately applied to a portion that is not particularly described.

  As shown in FIG.4 and FIG.5, the absorbent article 1 'of this embodiment has the form of what is called a deployment-type disposable diaper. As in the absorbent article 1 of the first embodiment, the absorbent article 1 ′ is a hydrophilic hot melt composition that visually changes when it comes into contact with moisture between the absorbent main body and the leak-proof sheet. It is arranged so that the coating film is scattered.

  The absorbent article 1 ′ includes a top sheet 11a, a leak-proof sheet 12, an absorbent body 13 disposed therebetween, and a side sheet 11b that covers the outer edge of the leak-proof sheet 12 from both side edges of the sheet 11a. ing.

  The absorbent body 13 has a rectangular outer shape, and is composed of an absorbent main body (absorbent core) 13a and non-woven fabrics 13b and 13c covering at least a part thereof.

  Fastening tapes 19 are respectively disposed on the left and right side edges of the back side portion 1A of the absorbent article 1 '. A landing zone (not shown) to which the fastening tape 19 is fixed is formed on the outer surface of the abdominal side portion 1B across the width direction. Elastic members 18 are fixed in a stretched state at portions located on the left and right side edges of the crotch part 1C in the leak-proof sheet 12, and these elastic members 18 contract and legs when the absorbent article 1 'is worn. Leg gathers are formed around the area.

  The surface sheet 11a of the absorbent article 1 'is a sheet of the same material as the surface sheet in the first embodiment, and the side sheet 11b is conventionally of this type of unfolded type such as a water-repellent nonwoven fabric. Sheets of materials used for disposable diapers can be used.

  As the material of the leak-proof sheet 12 of the absorbent article 1 ′, a sheet made of the same material as the leak-proof sheet of the first embodiment can be used.

  The absorbent article 1 ′ of the present embodiment is similar to the absorbent article of the first embodiment, as described above, between the leak-proof sheet 12 and the nonwoven fabric 13b, the coating film of a predetermined form has a predetermined interval. In addition to the presence or absence of absorption of bodily fluids such as urine, the amount of absorption can be estimated by the spread due to absorption, and therefore can be exchanged without error in timing.

  Next, an embodiment of the method for manufacturing an absorbent article of the present invention will be described based on the method for manufacturing the absorbent article 1 of the first embodiment.

  First, in order to manufacture the absorbent article 1, the absorbent main body 13 a is covered with the nonwoven fabrics 13 b and 13 c and the topsheet 11 is further arranged by a known manufacturing method of an absorbent body, and then the conveyance line of the leak-proof sheet 12 is provided. As shown in FIGS. 6 (a) and 6 (b), the hot melt composition is coated in the coating form from the inside of the roll coater 100 that rotates uniaxially before the joining. A hydrophilic hot melt composition is applied so as to be positioned between the absorbent main body and the leak-proof sheet by using a coating apparatus 10 that coats the surface of the workpiece. The roll coater is made of metal, and a fluid discharge path corresponding to the coating form such as the above-described shape of dots, patterns, characters, etc. is provided on the peripheral surface. Further, it is preferable that the peripheral surface of the roll coater is covered with a low thermal conductivity material such as ceramics or a cover to reduce the influence of heat on the contacting member.

  And as shown to Fig.6 (a), it has distribute | arranged so that the roll coater 100 which rotates uniaxially may contact the nonwoven fabric 13c which comprises the said absorber 13, and before the merge, with the leak-proof sheet 12 of the nonwoven fabric 13c A coating film of the hydrophilic hot melt composition is applied to the opposite surface, and then joined to the leak-proof sheet 12. Alternatively, as shown in FIG. 6B, a roll coater is placed in contact with the leak-proof sheet 12, and the hydrophilic hot water is placed on the surface of the leak-proof sheet 12 facing the nonwoven fabric 13c before joining. After the coating film of the melt composition is applied, it is joined to the leak-proof sheet 12. Thereby, it arrange | positions so that the coating film of a hydrophilic hot-melt composition may be scattered between the leak-proof sheet 12 and the nonwoven fabric 13c with the said coating form.

In this way, the hydrophilic hot melt composition is difficult to be formed by conventional coating methods such as curtain spraying by discharging the hot melt composition from the inside of the uniaxially rotating roll coater to form a coating film of the hydrophilic hot melt composition. The coating film pattern of the melt composition can be stably formed at high speed.
In addition, compared to the case of continuous application with a gap parallel to the product flow direction and coating in a pattern form, the application area of the hot melt composition relative to the area of the absorbent main body can be reduced, and the absorbency accordingly. It is possible to manufacture a product that prevents the moisture permeability of the article from decreasing and suppresses the occurrence of diaper rash.

  The absorbent body 13 in which the hydrophilic hot-melt composition is arranged and the leak-proof sheet 12 and the nonwoven fabric 13c are joined is then applied to the leg cover nonwoven fabric 14 and the outer layer in which the elastic members 15 to 18 are arranged by a known method. The absorbent article 1 is manufactured by joining with the conveyance line of the nonwoven fabric 15 and integrally joining them.

  According to the method for manufacturing an absorbent article of the present embodiment, an absorbent article that exhibits the above effects can be suitably manufactured.

The present invention is not limited to the embodiment.
For example, in the absorbent article of each of the above embodiments, the absorbent main body is coated with a hydrophilic nonwoven fabric, and the nonwoven fabric and a leak-proof sheet are disposed below the nonwoven fabric, and the hydrophilic composition is interposed therebetween. Any other layer configuration may be used as long as the configuration is provided.

It is a perspective view showing typically a 1st embodiment of an absorptive article of the present invention. It is the perspective view which showed typically the state which expand | deployed the absorptive article of 1st Embodiment and looked at one part fractured | ruptured. It is a figure which shows typically the cross section of the principal part of the absorbent article of 1st Embodiment. It is the perspective view which showed typically the state which fractured | ruptured partially 2nd Embodiment of the absorbent article of this invention. It is a figure (figure 3 equivalent figure) showing typically a section of an important section of an absorptive article of a 2nd embodiment. (A) And (b) is a figure which shows typically the coating process of the water-soluble hot-melt composition in the manufacturing process of the absorbent article of 1st Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 'Absorbent article 11 Top sheet 12 Leak-proof sheet 13 Absorber 13a Absorbent main body 13b, 23c Non-woven fabric 2 Coating film 10 Coating apparatus 100 Roll coater

Claims (4)

An absorbent article arranged such that a coating film of a hydrophilic hot melt composition that visually changes when it comes into contact with moisture between the absorbent main body and the leak-proof sheet,
The absorbent article with which the said hot-melt composition was apply | coated so that the space | interval of the outer edge part of the said adjacent coating film might be set to 1-100 mm.   The absorptive article according to claim 1 whose total area of said coat to the area of said absorptive main part is 50% or less.   The absorbent article of Claim 1 or 2 in which the said coating film has a form which combined the dot, the pattern, the character, or these. It is a manufacturing method of the absorptive article in any one of Claims 1-3,
When using a coating device that coats fluid from the inside of a roll coater that rotates uniaxially to the surface of the object to be coated, when it comes into contact with moisture so as to be positioned between the absorbent main body and the leak-proof sheet The manufacturing method of the absorbent article which coats the hydrophilic hot-melt composition which changes visually.

Images