The present invention relates to an absorbent article that includes a topsheet, a backsheet, and an absorber.
Conventionally, in an absorbent article such as a disposable diaper, a cooling sensation agent that imparts a cooling sensation for the wearer is sometimes disposed in the skin contact surface that is in contact with the wearer's skin (see Patent Document 1). The cooling sensation agent is enveloped by a micro-encapsulation agent that is dissolved by water, and then placed on the skin contact surface that is in contact with the wearer's skin. When the membrane is dissolved by the wearer's urine, the components of the cooling sensation agent are released, creating a stimulus by coming into contact with the wearer's skin. The wearer can thereby be aware of time to exchange the diaper.
An absorbent article has also been disclosed in which a substance is applied to impart a refreshing sensation to the wearer, not only with the function of suggesting the “time to exchange” as described above but also with the objective of for example, reducing the steaminess or stickiness when worn (see Patent Document 2).
However, as described above, the conventional absorbent article having a function of imparting cooling sensation to a wearer has entailed the following problem. A compound imparting cooling sensation (hereinafter, referred to as a refresher agent) is disposed at a position coining into direct contact with a wearer's skin; and therefore, some wearers feel that stimulation is too strong. Excessive stimulation gives the wearer a sense of discomfort rather than a refreshing sensation.
Patent Document 1: JP-A-2008-006277 (Page 4, FIG. 1)
Patent Document 2: JP-A-2007-525245
An absorbent article includes a topsheet having a contact surface that comes into contact with a skin of a wearer; a liquid-impermeable backsheet which does not permeate a liquid; and an absorber that is arranged between the topsheet and the backsheet, wherein a material including a refresher agent is provided between the topsheet and the backsheet, and
the material including the refresher agent is arranged at each side in a widthwise direction of the absorber.
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A description is provided for the absorbent article according to the embodiments, with reference to the drawings. In the following description of the drawings, identical or analogous parts are given identical or analogous reference numerals. It must be noted that the drawings are schematic ones, and the respective dimensional ratios and the like may differ from reality.
Accordingly, the specific dimensions and the like must be determined by consulting the following description. It is a matter of course that the interrelationships of the drawings also contain parts with mutually differing dimensional ratios and relationships.
An absorbent article according to an embodiment will be described with reference to
The absorbent article 1 in
The absorbent article 1 has a topsheet 10 in contact with the wearer's skin, a liquid-impermeable backsheet 20 through which liquids cannot pass, and an absorber 30. The absorbent article 1 includes a material 100 that contains a compound for giving the wearer a refreshing sensation (hereinafter, called a refresher agent) between the topsheet 10 and the backsheet 20. In this embodiment, the material that contains the refresher agent is referred to as the cooling sensation material 100.
The absorber 30 is arranged between the topsheet 10 and the backsheet 20. Therefore, the absorber 30 is indicated by the dotted line in
The topsheet 10 has: a first sheet 11 covering at least a surface of a wearer's side of the absorber 30; and second sheets 12 and 13 that are disposed at both sides in a widthwise direction of the first sheet 11.
The backsheet 20 has a wing 21 and a wing 22. The wing 21 and the wing 22 are formed in one pair at positions that correspond to a widthwise direction of the absorbent article 1. The wing 21 and the wing 22 are extended in the widthwise direction of the absorbent article 1 in the middle region M. A width of the middle region M of the backsheet 20 is greater than that of each of the forward region F and the rearward region R.
The first sheet 11 has a length which is substantially identical to that of the backsheet 20. A shape of an end part of the first sheet 11 is substantially identical to that of the backsheet 20. The first sheet 11 covers at least a surface of the absorber 30.
The second sheets 12 and 13 are arranged at both sides of the first sheet 11. The second sheet 12 covers a part of an end part of the absorber 30 and the wing 21. One end part in a longitudinal direction of the second sheet 12 is a substantially straight line, and is superimposed on one end part in a longitudinal direction of the first sheet 11. The other end part in the longitudinal direction of the second sheet 12 is coincident with a part of an outer circumference of the backsheet 20 and a shape of the wing 21.
It is preferable that dimensions in the longitudinal direction of the absorbent article 1 be within the range of 100 mm to 500 mm, and specifically, it is further preferable that the dimensions be within the range of 150 mm to 350 mm. In addition, it is preferable that dimensions of the widthwise direction be within the range of 30 mm to 200 mm, and specifically, it is further preferable that the dimensions be within the range of 40 mm to 180 mm.
The second sheet 13 covers a part of a side edge of the absorber 30 and the wing 22. One end part in a longitudinal direction of the second sheet 13 is a substantially straight line, and is superimposed on the other end part in the longitudinal direction of the first sheet 11. The other end part in the longitudinal direction of the second sheet 13 is coincident with a part of an outer circumference of the backsheet 20 and a shape of the wing 22.
As shown in
In addition, the second sheet 12 has: an edge part 12a in a widthwise direction of the second sheet 12; and a fold part that is positioned inside in a widthwise direction more than the edge part 12a. The second sheet 12 is superimposed on the first sheet 11, and in a state in which the edge part 11a in the widthwise direction of the first sheet 11 and the edge part 12a of the second sheet 12 are bonded with each other, the fold part 12b is folded to the outside in the widthwise direction of the first sheet 11, whereby a contact surface 10a coming into contact with a wearer's skin is formed. Like the second sheet 12, the second sheet 13 also has: an edge part 13a in a widthwise direction of the second sheet 13; and a fold part 13b that is positioned inside in the widthwise direction more than the edge part 13a, and is bonded with the end part 11b of the first sheet.
In addition, in the absorbent article 1, the first sheet 11, the second sheets 12 and 13, the backsheet 20, and the absorber 30 are bonded with each other. Circumferential edges of the first sheet 11, the second sheets 12 and 13, and the backsheet 20 are bonded with each other, and the absorber 30 is internally sealed.
As a method of bonding the topsheet 10 and the backsheet 20 with each other, it is possible to employ one of heat emboss processing and ultrasonic or hot melt type bonding agent or a combination of a plurality thereof. The first sheet 11 and the absorber 30 are brought into pressure contact with each other by means of a pressure contact unit 41 and a pressure contact unit 42. The pressure contact unit 41 and the pressure contact unit 42 are formed along a longitudinal direction of the absorber 30 at both sides in the widthwise direction of the absorber 30. In the embodiment, the pressure contact unit 41 and the pressure contact unit 42 are brought into pressure contact with each other by means of heat emboss processing.
In the backsheet 20, on a surface coming into contact with shorts, an adhesive agent, although not shown, is applied in a linear shape, along the longitudinal direction of the backsheet 20. The adhesive agent is applied in a plurality of lines along the longitudinal direction of the backsheet 20. In the wing 21 and the wing 22, an adhesive agent is also applied to a surface coming into contact shorts. A protective sheet for retaining stickiness is adhered to an adhesive material. The protective sheet is released by a wearer at the time of use of the absorbent article.
Next, the first sheets 11 and 12 will be specifically described.
In the embodiment, the first sheet 11 is a nonwoven cloth. A material for the first sheet 11 is not limitative in particular as long as it is a sheet-like material with its structure of permeating a liquid, such as a porous plastic sheet. As a material for cloth or nonwoven cloth, either of a natural fiber and a chemical fiber can be used.
As examples of natural fibers, there are exemplified celluloses such as ground pulp or cotton. As examples of chemical fibers, there are exemplified: reproducible celluloses such as rayon or fibril rayon; semisynthetic celluloses such as acetate or triacetate; thermoplastic hydrophobic chemical fibers; or thermoplastic hydrophobic chemical fibers or the like to which hydrophilic treatment is applied.
Examples of thermoplastic hydrophobic chemical fibers, there are exemplified a single fiber such as polyethylene (PE), polypropylene (PP), or polyethylene terephthalate (PET); a fiber made by graft-polymerization of polyethylene and polypropylene; or a composite fiber of a core-clad structure or the like.
As a method of web forming of a nonwoven cloth, there can be employed any one method of a dry type (a card technique, a spun bond technique, a melt blow technique, or an air-raid technique) and a wet type. Among the dry type technique and the wet type technique, a plurality of techniques may be combined with each other. In addition, a method such as thermal bonding, needle punching, or chemical bonding is exemplified. A method of producing a nonwoven cloth is not limitative to the methods described above.
Further, a spun lace formed in a sheet shape by means of a water entangling technique can be employed for the first sheet 11. Furthermore, a nonwoven cloth obtained by applying irregularities to a top layer side of the unwoven cloth or an irregular nonwoven cloth at which a total weight non-uniformity is provided by applying air at the time of forming webs can be employed for the first sheet 11. By forming irregularities on a surface, it is possible to alleviate a bodily liquid from diffusing along a surface of the first sheet 11 before permeating the first sheet 11.
The second sheets 12 and 13 can be selected from among the materials similar to those for the first sheet 11. However, it is preferable to have hydrophobic property or water repellent property in order to prevent menstrual blood from flowing over the second sheets 12 and 13 outward of the absorbent article 1. Specifically, a spun bond nonwoven cloth, an SMS nonwoven cloth or the like is exemplified. The second sheets 12 and 13 constitute a skin contact surface 10a. Therefore, it is preferable to employ an air-through nonwoven cloth in order to reduce frictional stimulation to skin.
Next, the backsheet 20 will be specifically described.
In the embodiment, as the backsheet 20, there can be employed: a film which consists essentially of polyethylene, polypropylene or the like; an air ventilation resin film; or a sheet or the like obtained by bonding a ventilation resin film with a nonwoven cloth such as a spun bond or a spun lace. It is preferable that the backsheet 20 be a material having its flexibility to an extent such that a sense of discomfort at the time of wearing is unlikely to occur. For example, it is preferable to use a film which consists essentially of a low-density polyethylene (LDPE) resin, a total weight (weight (g) per unit area) of which is within the range of 15 g/m2 to 30 g/m2.
Next, the absorber 30 will be specifically described.
The absorber 30 includes a hydrophilic fiber or pulp. As examples of hydrophilic fibers, there can be employed solely or in combination: celluloses such as ground pulp or cotton; reproducible celluloses such as rayon or fibril rayon; semisynthetic celluloses such as acetate or triacetate; particle-like polymers, fiber-like polymers, thermoplastic hydrophobic chemical fibers, or thermoplastic hydrophobic chemical fibers to which hydrophilic treatment is applied. Among them, it is preferable to use crushed pulse in consideration of low cost and easiness of molding an absorber.
The absorber 30 may be constituted by covering a hydrophilic fiber and a polymeric absorber with a coating material. In the embodiment, the polymeric absorber is a grain-like polymer such as sodium acrylate copolymer having absorbability and hygroscopic property. In addition, to the absorber 30, there may be added, for example, grain-like deodorant materials such as silver, copper, zinc, silica, activated carbon, aluminosilicate compound, or zeolite, copper, zinc, silica, activated carbon, aluminosilicate, or zeolite; or grain-like antimicrobial. Further, a grain-like refresher agent having its cooling effect due to heat absorption reaction may be added thereto.
The absorber 30 may be an air-raid sheet obtained by molding a hydrophilic fiber or powder in a sheet shape by means of an air-raid technique. In a case where the air-raid sheet is used as the absorber 30, it is preferable that a thickness of the air-raid sheet be 0.3 mm to 5.0 mm. As an example of air-raid sheet, there is employed the one obtained by molding a fiber and a grain-like polymer to be a sheet material by means of a binder or the like. The grain-like polymer may be dispersed in a layered shape or may be biased in a thickness direction in the air-raid sheet.
On the absorber 30, embosses may be formed in order to prevent deformation or folding while in wearing or to adjust a thickness. These embosses for the absorber 30 can be formed by passing the absorber between a patterned emboss roll and a flat roll. While the pattern for the emboss roll is formed in a lattice shape, in a dotted shape, or in a wavy shape, it is preferable to employ a lattice-shaped pattern which is easily adjusted in thickness.
Next, the cooling sensation material 100 will be specifically described.
In the embodiment, it is preferable that a cooling sensation material 100 be carried by a porous material which is capable of adsorbing molecules by a plenty of small pores. The refresher agent is menthol, camphor, and thiol or the like, which are cyclo-hexanol derivatives, for example. In addition, the porous material is silica gel, alumina, zeolite, a nano-porous material or the like, for example.
The refresher agent carried (adsorbed) by the porous material is substituted by water (water steam) by means of capillary coagulation under a high humidity, and is discharged to the outside of the porous material. An interrelationship between a small pore diameter and a relative humidity of the porous material with which capillary coagulation occurs is in accordance with a so called Kelvin formula.
A humidity that is generally determined to be “confortable” is said to be 45% to 55%. In addition, when a temperature in shorts is 33 degrees C. to 37 degrees C., if humidity reaches the order of 60%, a result that a wearer feels heating is obtained.
Therefore, a porous material is used which has a small pore diameter in which there occurs substitution between molecules and water content in which the small pore diameter of the porous material is adsorbed under a desired humidity. Specifically, the porous material has a small pore diameter in which water steam causes a capillary coagulation when the temperature is within the range of 20 degrees C. to 40 degrees C. and the relative humidity is within the range of 60% to 85%. In addition, small porous each having its small porous diameter that meets a condition in which water steam causes a capillary coagulation when the temperature is within the range of 20 degrees C. to 40 degrees C. and the relative humidity is within the range of 60% to 85% occupy 30% to 100% of all of the small pores of the porous material.
As one example, in a case where the porous material is silica gel, the small pore diameter is within the range of 4 nm to 13 nm according to the Kelvin formula. If the small pore diameter is smaller than 4 nm, the refresher agent is discharged in a state in which the relative humidity is lower than 60%, that is, under a confortable condition in which a wearer does not feel heating.
Alternatively, in a case where the small power diameter exceeds 13 nm, since the refresher agent is not discharged even if the humidity exceeds 85%, a wearer is disallowed to have cooling sensation even under a condition in which the wearer feels heating. In addition, it is preferable that an average particle size of the porous material be 1.5 mm or less. If the average particle size of the porous material exceeds 1.5 mm, a wearer feels a sense of discomfort.
While the amount of the refresher agent to be carried by the porous material is different depending on the average particle size, small power diameter distributions or the like, of the porous material, it is preferable that the amount be within the range of 1 g/m2 to 100 g/m2. If the amount is 1 g/m2 or less, it is difficult to impart cooling sensation to a wearer. Alternatively, if 100 g/m2 is exceeded, it is not preferable, since stimulation is too strong for the wearer.
As described above, the refresher agent is disposed at a predetermined position in a state in which the agent is carried by the porous material. In addition, a refresher agent such as menthyl lactate or menthone glycerin acetal, which is soluble in a specific solvent, can be applied at a predetermined position in a state of solution.
There are several disposition methods of disposing the cooling sensation material 100 at the position illustrated in the abovementioned embodiment, as set forth below. The disposition method 1 is a method of disposing the cooling sensation material 100 in a case where a refresher agent is carried by a porous material. Specifically, in a region in which a hot melt type adhesive agent is applied, the cooling sensation material 100 is adhered by employing a roll.
If the surface treatment roller 203 rotates in a state in which the roll is brought into contact with the cooling sensation material 100 that is reserved in the reservoir 204, the small pores formed on the surface of the roll are charged with the cooling sensation material 100. The surface treatment roller 203 comes into contact with the surface of the material 110, whereby the cooling sensation material 100 is transferred to the surface of the material 110 to which HMA is applied.
Here, the material 110 is a respective one of the second sheets 12 and 13 or the backsheet 20, for example. That is, by means of the arrangement device 200 of
In addition, since, in this disposition method, the cooling sensation material 100 is adhered to the second sheets 12 and 13 or the backsheet 20 by means of HMA, it is possible to prevent the cooling sensation material 100 from slipping off from a predetermined disposition position (regions A1 and A2), and it is also possible for a wearer to have a confortable cooling sensation.
In a case where a heat vulnerable material is used as the backsheet 20, it may also be difficult to apply HMA to the backsheet 20. Therefore, it is preferable to dispose such material on a back face of each of the second sheets 12 and 13.
The second arrangement method is a method in which a refresher agent, such as methyl lactate and menthone glycerin acetal, soluble in a specific solvent, is applied to a given position while being a solution. When the refresher agent is a solution, a coater application can be used.
The cooling sensation material 100 is applied to a surface in a predetermined region of the material 110 by means of a coater 300. The cooling sensation material 100 is applied to applying regions PA and PB. This cool feeling material is conveyed while a longitudinal direction of the material 110 that constitutes an absorbent article is made coincident with the conveyance direction MD.
Further, by employing a so called flexographic coating method or gravure coating method or the like, as shown in
As described above, according to the absorbent article 1 according to the embodiment, the cooling sensation material 100 is arranged between the topsheet 10 and the backsheet 20 and at each side in the widthwise direction of the absorber 30, whereby the cooling sensation agent 100 does not come into direct contact with a wearer's skin.
The cooling sensation material 100 is discharged from a porous material under a high humidity environment. The discharged cooling sensation material 100 comes into contact with a skin cool feeling acceptance device TRPM8 (CMR1), and increases a threshold value of the acceptance device in order of 0 degrees C. to 5 degrees C. In this manner, an effective temperature of a skin is reduced in order of 0 degrees C. to 5 degrees C. in a state in which a skin environment temperature is kept unchanged. Therefore, a wearer can obtain cooling sensation, since the effective temperature is reduced under an environment in which the wearer feels heating.
Further, the cooling sensation material 100 is disposed at a position which does not come into direct contact with a bodily liquid (water content). Therefore, it is possible to prevent discharge of a cooling material due to the cooling sensation material 100 corning into direct contact with the bodily liquid. In this manner, a cooling action can be sustained. In addition, before a condition in which a wearer feels heating is established, the cool feeling material comes into contact with water content to be thereby able to prevent a malfunction that a cooling material is discharged.
The cooling sensation material 100 is arranged at a back face side of each of the second sheets 12 and 13. In a case where the second sheets 12 and 13 are liquid-impermeable, an advantageous effect that the cooling sensation material 100 does not come into direct contact with water content can be enhanced. Therefore, a cooling material is not discharged until a condition in which a wearer feels heating is established.
In addition, in the absorbent article 1, the second sheet 12 is superimposed on the first sheet 11, and in a state in which the edge part 11a in the widthwise direction of the first sheet 11 and the edge part 12a of the second sheet 12 are bonded with each other, the fold part 12b is folded back to the outside in the widthwise direction of the first sheet 11, whereby the contact surface 10a coming into contact with a wearer's skin is formed. In this manner, it is possible to prevent water from blurring out from between the adhered sheets to the back face side of each of the second sheets 12 and 13, in comparison with a case of adhering back faces of the first sheet 11 and the second sheets 12 and 13. Therefore, an advantageous effect of preventing the water content on the surface of the first sheet 11 from coming into contact with the cooling sensation material 100 is enhanced.
As described above, while the contents of the present invention were disclosed through the embodiment, it should not be understood that the discussion and drawings forming a part of this disclosure limit the present invention. From this disclosure, a variety of alternative embodiments, examples, and operational techniques would have been self-evident to one skilled in the art.
For example, the embodiment can be modified as follows. While the foregoing embodiments each described that an absorbent article is a sanitary napkin, the embodiment can be applied to a so called liner, an incontinence article or the like (referred to as an incontinence pad) as well.
In addition, the absorbent article is not limitative to a planar shape disclosed in
In the absorbent article, a gather made of an elastic material such as a resilient material may be provided at each end part in the widthwise direction of the absorber in order to prevent side leakage of bodily liquid such as menstrual blood.
As a polymeric absorber, there can be employed a grain-like polymer such as a sodium acrylate copolymer having absorbability or absorbance. In addition, between the topsheet and the backsheet, apart from an absorber, a polymeric absorber, and a hygroscopic material, there may be arranged grain-like deodorants such as silver, copper, zinc, silica, activated carbon, aluminosilicate compound, or zeolite.
Some of electrolytes that can be utilized as the hygroscopic material such as silver, copper, zinc, silica, activated carbon, aluminosilicate compound, and zeolite include those having efficacy in suppressing microbial breeding (an antibacterial effect or bactericidal project). For example, when an electrolyte having efficacy in suppressing microbial breeding is used as the hygroscopic material, then the efficacy in suppressing microbial breeding can be imparted to the absorbent article.
As described above, of course, the present invention includes a variety of embodiments or the like which are not described herein. Therefore, a technical scope of the present invention is defined by only specific matters of the invention according to the claims that are reasonable from the foregoing description.
A volunteer was instructed to wear a test product, and “heating” was measured by means of functional evaluation.
A tissue was employed as a covering material. L-menthol carrying B-type silica gel was disposed between the tissue and the mixture as an absorber, and then, was fixed by means of a hot melt adhesive agent. The resultant L-menthol carrying B-type silica gel was disposed between the second sheets 12 and 13 and the first sheet 11, all of which were fixedly bonded with a hot melt adhesive material. The disposition quantity was 50 g/m2.
A sample product was worn on shirt.
A small-sized temperature and humidity meter was mounted at a relative position to the perineum part on a sanitary napkin.
In the abovementioned environment, a volunteer was caused to maintain a standing posture for 60 minutes. As a result, the volunteer did not feel heating immediately after wearing (humidity 55%). Fifteen minutes after wearing, the volunteer felt cooling sensation after the heating in the crotch had exceeded 60%. Thereafter, while the humidity rose up to 80% within 45 minutes, a result that no heating was felt was obtained. This result is deemed to be because a cooling material was discharged under the testing condition.
The entire contents of JP-A-2009-088487 (filed on Mar. 31, 2009) are incorporated in the present specification by reference.
According to the present invention, it is possible to prevent an excessive stimulation from being imparted to a wearer by means of a refresher agent, and it is also possible to reliably restrain a sense of discomfort due to heating, stickiness or the like.
Number | Date | Country | Kind |
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2009-088487 | Mar 2009 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2010/055921 | 3/31/2010 | WO | 00 | 12/5/2011 |