JP2006055268A - Absorbent article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absorbent article, which, when peeled from shorts or the like, scarcely issues a peeling sound and scarcely leaves an adhesive on shorts, or the like. <P>SOLUTION: This absorbent article 1 is provided with a body 5 and an adhesion part 6 formed on a skin non-abutment face of the body 5, the adhesion part 6 is formed of a first adhesion layer 61 adjoining to the body 5 and a second adhesion layer 62 superposed on the first adhesion layer 61, the storage modulus of the adhesive constituting the second adhesion layer 62 is 1×10<SP>3</SP>to 2×10<SP>6</SP>Pa at 25°C, and the adhesive force of the first adhesion layer 61 is higher than the adhesive force of the second adhesion layer 62. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an absorbent article such as a sanitary napkin, a panty liner (cage sheet), and an incontinence pad.

Conventionally, in absorbent articles such as sanitary napkins, panty liners (orimono sheets), incontinence pads, breast milk pads, etc., it is common to provide an adhesive part for fixing to clothes such as shorts on the non-skin contact surface Has been done.
Patent Document 1 describes an absorbent article in which a non-skin contact layer is provided with a barrier layer made of a thermoplastic resin, and an adhesive is coated on the barrier layer. It is described that the barrier layer may be composed of a hot melt adhesive.
Patent Document 2 discloses an absorbent article having a wing adhesive portion in a wing portion of an absorbent article having a wing portion, and a main body adhesive portion that is detachably overlapped with the wing adhesive portion on the back surface of the main body. Are listed.

JP 2000-140016 A JP 2001-145668 A

However, in a conventional absorbent article provided with a fixing adhesive part on the non-skin contact surface, the adhesive part is formed using a relatively highly elastic adhesive, and the absorbent article is pulled from shorts or the like. At the time of peeling, there is a problem that a peeling noise such as a burr is generated by the adhesive part partially pulling and deforming the surface of the fabric having unevenness. When changing in a toilet or a changing room or the like, this may cause the user to be aware of or be aware of the replacement or use of the absorbent article, and stress the user. Also in the absorbent article described in Patent Document 1, a relatively highly elastic pressure-sensitive adhesive is used as the pressure-sensitive adhesive to be coated on the barrier layer, and the peeling sound has not been considered.
Furthermore, the present inventors examined the formation of the adhesive portion using a low-elasticity adhesive in order to reduce the peeling noise. Adhesive strength with the part becomes unstable, and when the absorbent article is peeled off from clothes such as shorts, the adhesive part may be peeled off from the main body and a part of the adhesive may remain on the shorts. .
In addition, the absorbent article described in Patent Document 2 is used by peeling between the wing adhesive portion and the main body adhesive portion, and its purpose (effect) and configuration are greatly different from those of the present invention.

  Accordingly, an object of the present invention is to provide an absorbent article that hardly causes a peeling sound when the absorbent article is peeled from shorts or the like and that does not easily leave an adhesive on the shorts or the like.

The present invention includes a main body and an adhesive portion formed on a non-skin contact surface of the main body, and the adhesive portion is laminated on the first adhesive layer adjacent to the main body and the first adhesive layer. The storage elastic modulus of the pressure-sensitive adhesive comprising the second pressure-sensitive adhesive layer and constituting the second pressure-sensitive adhesive layer is 1 × 10 ³ to 2 × 10 ⁶ Pa at 25 ° C., and the adhesive force of the first pressure-sensitive adhesive layer is the second pressure-sensitive adhesive. The above object is achieved by providing an absorbent article having a higher adhesive strength than the layer.

  In the absorbent article of the present invention, when the absorbent article is peeled off from shorts or the like, it is difficult for peeling sound to occur, and it is difficult to leave an adhesive on the shorts or the like.

Hereinafter, the present invention will be described in detail based on preferred embodiments thereof.
As shown in FIGS. 1 and 2, a sanitary napkin 1 according to an embodiment of the present invention includes a liquid-permeable surface sheet 2 that forms a skin contact surface and a liquid impermeable material that forms a non-skin contact surface. It has a main body 5 having a permeable back sheet 3 and a liquid-retaining absorbent 4 interposed between the two sheets, and an adhesive portion 6 formed on the non-skin contact surface of the main body 5.
Both side edges of the surface sheet 2 cover both sides of the absorber 4 and are wound down to the back sheet 3 side, and are joined to the back sheet 3 via an adhesive in the vicinity of both side edges in the longitudinal direction of the absorber 4. ing. Further, the top sheet 2 and the back sheet 3 are joined to each other by heat sealing at portions extending from both longitudinal edges of the absorber 4 to form end seal portions 11 and 11.

The adhesive portion 6 is for fixing the sanitary napkin 1 to clothes such as shorts, and is formed in a vertically long rectangular shape on the non-skin contact surface made of the back sheet 3.
As shown in FIG. 2, the adhesive portion 6 includes a first adhesive layer 61 adjacent to the main body 5 and a second adhesive layer 62 laminated on the first adhesive layer 61.
In this napkin 1, the adhesive which comprises the 2nd adhesion layer 62 uses a low elasticity thing compared with the conventionally used adhesive. That is, the storage elastic modulus of the adhesive constituting the second adhesive layer is 1 × 10 ³ to 2 × 10 ⁶ Pa at 25 ° C.
Therefore, as shown in FIG. 3, the second adhesive layer 62 is easily deformed and smoothly enters the concave portion of the fabric surface (such as the inner surface of the crotch portion) 7 having irregularities in clothing such as shorts. A good adhesive force can be obtained with respect to shorts and the like, and when the napkin 1 is peeled off, the second adhesive layer 62 is smoothly peeled off while being deformed, and thus a peeling sound is hardly generated. The fact that the peeling sound is less likely to occur is advantageous in that other people do not notice the use or replacement of the napkin.

  And in this napkin 1, the adhesive force of the 1st adhesion layer 61 is made higher than the adhesive force of the 2nd adhesion layer 62, Therefore As an adhesive which comprises the 2nd adhesion layer 62, as mentioned above Even when a low-elasticity material is used, a stable adhesive force can be obtained between the main body 5 and the pressure-sensitive adhesive portion 6. Therefore, when the napkin 1 is peeled off from clothes such as shorts, the pressure-sensitive adhesive portion 6 is removed from the main body 5. There is no inconvenience of peeling off. Needless to say, when the napkin 1 is peeled off, neither the first adhesive layer 61 nor the second adhesive layer 62 is peeled off.

From the viewpoint of preventing the occurrence of peeling noise, the pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer 62 has a storage elastic modulus measured by a measurement method described later of 1 × 10 ³ to 2 × 10 ⁶ Pa at 25 ° C. More preferably, it is 1 × 10 ^{3 to} 5 × 10 ⁵ Pa at 25 ° C., and more preferably 5 × 10 ³ to 1 × 10 ⁵ Pa at 25 ° C.
In addition, from the viewpoint of preventing the adhesive from remaining on the shorts while preventing the generation of peeling sound, the storage elastic modulus of the adhesive constituting the second adhesive layer 62 is that of the adhesive constituting the first adhesive layer 61. It is preferably 0.1 to 50% of the storage elastic modulus, more preferably 1 to 40%, and even more preferably 5 to 30%. The storage elastic modulus of the adhesive constituting the first adhesive layer 61 is preferably 1 × 10 ⁴ to 8 × 10 ⁷ Pa at 25 ° C., and 1 × 10 ^{4 to} 5 × 10 ⁶ Pa at 25 ° C. More preferably, it is 2 × 10 ^{4 to} 7 × 10 ⁵ Pa at 25 ° C.

  Further, from the viewpoint of obtaining a stable and sufficient adhesive force between the adhesive part 6 and the main body 5, the first adhesive layer has an adhesive force measured by a measuring method described later of 300 cN / 25 mm or more, particularly 500 cN / 25 mm or more. The ratio of the adhesive force of the first adhesive layer to the adhesive force of the second adhesive layer (the former / the latter) is preferably 2.0 or more, and more preferably 3.0 or more. preferable.

The storage elastic modulus of the pressure-sensitive adhesive constituting the first pressure-sensitive adhesive layer 61 and the second pressure-sensitive adhesive layer 62 can be measured as follows.
<Method for measuring storage modulus>
The measurement is performed using a DMS110 bending module of a viscoelastic spectrometer manufactured by Seiko Denshi Kogyo Co., Ltd. Apply the adhesive to be measured to a release paper within 3mm thickness, cut the adhesive sample into a width of 10mm and a length of 40mm, peel off the release paper, and set only the adhesive at a predetermined position on the sample stage of the measuring instrument. To do. The frequency is set to 1 Hz, the static load is set to 0.1 cN / m ² , the storage elastic modulus (G ′) at −100 ° C. to 150 ° C. is measured, and the storage elastic modulus (G ′) at 25 ° C. at that time is measured. read.

The adhesive strength of the first adhesive layer 61 and the second adhesive layer 62 can be measured as follows.
<Measurement method of adhesive strength of adhesive layer>
Evaluation is performed using a tensile tester (A & D Tensilon Universal Tester RTC1210) in an environment of 20 ° C. and 50% HR. The pressure-sensitive adhesive sample was prepared by cutting the pressure-sensitive adhesive layer applied to the release paper to a basis weight of 50 g / m ² in advance so as to have a width of 30 mm, and re-attaching it to a PET film that was not peeled. Cut to a length of 150 mm in consideration of the grip allowance, and then cut to a width of 25 mm. The sample on the adherend side is used by sticking a double-sided tape with a width of 50 mm or more on a smooth flat plate and attaching an olefin-based film used for a napkin or the like thereon. Next, the adhesion-side sample and the adherend-side sample are bonded together, and a 2 kg roller is moved back and forth, and measurement is performed 30 seconds after pressure bonding. Measurement is performed at a peeling speed of 300 mm / min and 180 ° peeling. The maximum average value of the measurement results at that time is taken as the value.
In addition, when measuring the adhesive force of the first layer from the state formed on the napkin, after removing the adhesive layer of the first layer portion using an organic solvent (for example, toluene), the adhesive force is measured using the measurement method. taking measurement.

  The thickness t <b> 2 (see FIG. 2) of the second adhesive layer 62 ensures the effect of preventing peeling noise, and when the napkin 1 is peeled off from shorts or the like, the second adhesive layer 62 is divided or peeled off. From the viewpoint of preventing this, it is preferably 0.03 to 0.5 mm, particularly preferably 0.05 to 0.3 mm. The thickness t2 of the second adhesive layer 62 is preferably 1 to 50 times the thickness t1 of the first adhesive layer 61, and more preferably 2 to 20 times. The thickness t1 of the first adhesive layer 61 is preferably 0.01 to 0.5 mm, particularly preferably 0.015 to 0.3 mm.

  In the napkin 1, as shown in FIG. 2, the coating width of the second adhesive layer 62 is narrower than the coating width of the first adhesive layer 61, and the second adhesive layer 62 on both sides of the first adhesive layer 61. Since the extension width W (see FIG. 2) is 0 to 3 mm, the second adhesive layer 62 and the back sheet are not in direct contact with each other, preventing adhesive residue and applying the adhesive in two stages. It is preferable from the viewpoint of increasing the degree of freedom of basis weight (the same applies when the second adhesive layer 62 extends from the front and rear ends in the longitudinal direction of the napkin 1 by 0 to 3 mm).

  The adhesive part 6 in the napkin 1 is covered with a conventionally known adhesive part protective sheet (not shown) such as a release paper or a peeled resin film, and is protected until the napkin 1 is used. In use, like the conventional napkin, the adhesive portion protective sheet is peeled off to expose the adhesive portion 6, and the napkin 1 is fixed to clothing such as shorts via the adhesive portion 6.

  Examples of the pressure-sensitive adhesive constituting the first pressure-sensitive adhesive layer 61 include styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), and styrene-ethylene-butylene-ethylene copolymer. A hot-melt pressure-sensitive adhesive such as coalescence (SEBS) can be used. Among these, it is preferable to use a styrene-isoprene-styrene block copolymer (SIS) from the viewpoint of increasing the adhesive strength to the main body 5 and facilitating familiarity and increasing the adhesion strength to the base material. These hot melt pressure-sensitive adhesives can be used by adjusting the storage elastic modulus (G ′) and adhesive strength by adjusting the amount of additives such as oil components.

  Examples of the pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer 62 include a styrene-isoprene-styrene block copolymer (SIS), a styrene-butadiene-styrene block copolymer (SBS), and a styrene-ethylene-butylene-ethylene copolymer. Hot melt pressure-sensitive adhesives such as coalescence (SEBS) and gel-type pressure-sensitive adhesives used in happing agents can be used, and among these, styrene-ethylene-butylene-ethylene is used because of little change in adhesive properties over time. It is preferable to use a copolymer (SEBS). These hot melt pressure-sensitive adhesives can be used by adjusting the elastic force and adhesive force by adjusting the amount of additives such as oil components.

  From the viewpoint of preventing delamination between both layers, the adhesive constituting the first adhesive layer 61 and the adhesive constituting the second adhesive layer 62 can increase the adhesion at the boundary by melt coating. An adhesive is preferable, and a rubber-based pressure-sensitive adhesive using the same type of base polymer is more preferable because the affinity can be enhanced.

  As a material for forming the back sheet 3 (material for forming the non-skin contact surface of the main body 5), in the case of liquid impermeability, absorption of sanitary napkins, panty liners (orimono sheets), incontinence pads, etc. A material used as a back sheet of a functional article can be used without particular limitation, for example, a resin film made of a polyolefin resin such as polyethylene, polypropylene, polystyrene, a polyurethane resin such as urethane, calcium carbonate, barium sulfate, etc. The moisture-permeable (porous) polyolefin sheet, the SMS nonwoven fabric and the SMMS nonwoven fabric dispersed in a single layer, a multilayer, a composite with a film, etc. can be used. It is particularly useful in the case of a back sheet mainly composed of polyethylene of polyolefin resin.

  In the napkin 1 according to the present embodiment, for example, the absorbent body 4 is intermittently disposed on the continuous body of the top sheet 2, and the continuous body of the back sheet 3 is further stacked thereon to form a continuous body of the main body 5. The first hot-melt pressure-sensitive adhesive is applied to the surface on the back sheet 3 side of the continuum of the main body 5 to form the first pressure-sensitive adhesive layer 61, and the second hot water is formed on the first pressure-sensitive adhesive layer 61. The melt pressure-sensitive adhesive can be applied to form the second pressure-sensitive adhesive layer 62, and then a predetermined portion of the continuous body can be heat-sealed and cut to the size of each napkin 1. As the first and second hot melt pressure-sensitive adhesive coating apparatuses, a slot coater, a spiral coater, a spray coater, or the like can be used, respectively.

  Moreover, it replaces with the said manufacturing method, while applying the 1st hot-melt adhesive to the surface by the side of the back surface sheet 3 in the continuous body of the main body 5, and forming the 1st adhesion layer 61, it is continuous or discontinuous. After the second hot melt pressure-sensitive adhesive is applied on the pressure-sensitive adhesive part protective sheet to form the second pressure-sensitive adhesive layer 62, the pressure-sensitive adhesive part 6 can be formed by superimposing these two pressure-sensitive adhesive layers. In addition, regarding the manufacturing method of the napkin 1 mentioned above, a conventionally well-known method can be used for the point which is not demonstrated especially.

  Next, a sanitary napkin 1 ′ as another embodiment of the present invention will be described with reference to FIGS. 4 and 5. About this napkin 1 ', a different point from the napkin 1 mentioned above is demonstrated, the same point attaches | subjects the same code | symbol and abbreviate | omits description. For the points that are not particularly described, the above description of the napkin 1 is applied as appropriate.

  In the napkin 1 ′, the second adhesive layer 62 is formed by applying a pressure-sensitive adhesive on the first adhesive layer 61. Specifically, the pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer 62 is coated such that a plurality of dot-shaped pressure-sensitive adhesive portions that are circular in plan view are formed side by side. Thus, when the adhesion part is formed apart, it is preferable from a viewpoint that the surface area which can be fixed to the shorts cloth of an adhesive increases, and adhesiveness is stabilized.

As another pattern in the case of pattern coating the pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer 62, it can be applied in a lattice shape or a stripe shape instead of the dot shape like the present napkin 1. In addition, the shape of each dot in the case of pattern coating in a dot shape can be an arbitrary shape such as an ellipse, a rectangle, a triangle, a rhombus, a heart shape, and a star, in addition to a circle.
By applying the pattern, the adhesion area of the second adhesive layer 62 to the surface of the fabric such as shorts is reduced, so that the effect of preventing peeling sound can be further improved. The ratio of the area of the second pressure-sensitive adhesive 62 to the area of the first pressure-sensitive adhesive layer 61 (area ratio) is 5 to 85%, particularly 10 to 50%. This is preferable from the viewpoint of smooth peeling when the napkin or the like is peeled off.

The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.
For example, the absorbent article in the present invention may be a panty liner (origami sheet), an incontinence pad, a breast milk pad, etc. in addition to a sanitary napkin. Further, the material constituting the non-skin contact surface of the main body 5 is not limited to a liquid-impermeable material, and may be a liquid-permeable material, a nonwoven fabric, a fabric such as a woven fabric or a knitted fabric, and an aperture film. . The configuration of the main body is not particularly limited as long as it has an absorber and has a skin contact surface and a non-skin contact surface.

Example 1
<Manufacture of body>
The body of the sanitary napkin was a product obtained by removing the anti-slipping adhesive from the Kaori Co., Ltd. Laurier smooth cushion (for normal use, without wings). Actually, the main body was manufactured without performing the adhesive coating process in the manufacturing line. In addition, you may use what removed the adhesive from the commercially available sanitary napkin using the organic solvent (toluene etc.).

<Formation of adhesive part>
For the first adhesive layer, a hot melt adhesive in which a base polymer (styrene ethylene butylene styrene block copolymer), a tackifier (hydrogenated petroleum resin) and a plasticizer (paraffin oil) are mixed in a molten state is used. The storage elastic modulus at 7 ° C. was 7 × 10 ⁴ Pa, and the adhesive force to the olefin-based sheet was 650 cN / 25 mm. The hot melt pressure-sensitive adhesive is previously applied to a release paper to a thickness of 10 μm and cut in a width of 33 mm × 155 mm.
For the second adhesive layer, a hot melt adhesive in which a base polymer (styrene ethylene butylene styrene block copolymer), a tackifier (hydrogenated petroleum resin) and a plasticizer (paraffin oil) are mixed in a molten state is used. storage modulus at ℃ is at 3 × 10 ⁴ Pa, the adhesive strength against an olefin-based sheet was 220 cN / 25 mm. The hot melt pressure-sensitive adhesive is previously applied to a release paper to a thickness of 50 μm and cut to a width of 30 mm × 150 mm.
The said 1st adhesion layer was affixed on the center part of the non-skin contact surface of a main body, and the said 2nd adhesion layer was transcribe | transferred to the upper surface center.

(Example 2, Comparative Example 1)
In Example 2 and Comparative Example 1, a main body (a sanitary napkin) was prepared in the same manner as in Example 1.
In Example 2, the same pressure-sensitive adhesive as in Example 1 was used in the same size, but the thickness of the first pressure-sensitive adhesive was changed to 20 μm and the thickness of the second pressure-sensitive adhesive was changed to 250 μm.
In Comparative Example 1, the same pressure-sensitive adhesive as the first pressure-sensitive adhesive layer used in Example 1 was prepared with a thickness of 40 μm and a width of 30 mm × 150 mm, and was attached to the central portion of the non-skin contact surface of the main body.

(Evaluation)
About each napkin, (1) adhesiveness and (2) peeling sound were evaluated with the following method, and the result was shown in Table 1.

(1) Adhesiveness The sanitary napkins of Examples 1 and 2 and Comparative Example 1 were attached to the following various fabrics, and a 2 kg roller was reciprocated once from above to adhere them. After bonding (within 20 seconds), use a push bull gauge to fix the napkin bonded to the cloth at room temperature. The maximum load at that time was measured.
a. Kanakin fabric with a width of 70 mm and a length of 200 mm (Japanese Standards Association, Kanakin No. 3)
b. Commercially available sanitary short crotch cloth 1: Laurier active guard Cotton feel c. Commercially available sanitary shorts crotch cloth 2: Sophie safety fit

(2) Peeling sound In the same manner as the adhesive evaluation in (1) above, the sanitary napkins of Examples 1 and 2 and Comparative Example 1 were bonded to the above-mentioned various fabrics, and after bonding (within 20 seconds), there was no sound. At a chamber (environmental condition: room temperature), the film was peeled off by hand at a speed of peeling normally (equivalent to 2000 mm / min), the sound pressure (dB) at the time of peeling was measured, and the maximum value was defined as the peeling sound. For measurement, a SA-27 1/3 octave real-time analyzer manufactured by Lion was used, and the sound pressure level was measured at a frequency of 25 Hz to 20000 Hz with the distance from the microphone set to about 30 cm.

  As shown in Table 1, in Example 1 and Example 2 of the present invention, a decrease in peeling sound of about 10 to 15 dB was observed compared to Comparative Example 1, and a decrease in peeling sound was recognized even by hearing.

It is a perspective view which shows the sanitary napkin as one Embodiment of the absorbent article of this invention. FIG. 2 is a schematic cross-sectional view taken along the line XX in FIG. FIG. 3 is a schematic cross-sectional view (cross-sectional view corresponding to FIG. 2) showing a state in which the sanitary napkin of FIG. 1 is adhesively fixed to the surface of the cloth having irregularities in clothing such as shorts. It is a perspective view which shows the sanitary napkin as other embodiment of the absorbent article of this invention. FIG. 5 is a schematic cross-sectional view taken along line YY in FIG.

Explanation of symbols

1,1 'sanitary napkin 5 body 6 adhesive part 61 first adhesive layer 62 second adhesive layer 7 fabric surface having irregularities of clothing such as shorts

Claims (4)

A first adhesive layer adjacent to the main body, and a second adhesive layer laminated on the first adhesive layer, the main body; and an adhesive portion formed on a non-skin contact surface of the main body. The storage elastic modulus of the pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer is 1 × 10 ³ to 2 × 10 ⁶ Pa at 25 ° C., and the adhesive strength of the first pressure-sensitive adhesive layer is the adhesive strength of the second pressure-sensitive adhesive layer. Higher absorbent article than.   The absorbent article according to claim 1, wherein the thickness of the second adhesive layer is 1 to 50 times the thickness of the first adhesive layer.   The absorbent article according to claim 1 or 2, wherein the storage elastic modulus of the adhesive constituting the second adhesive layer is 0.1 to 50% of the storage elastic modulus of the adhesive constituting the first adhesive layer. The absorbent article in any one of Claims 1-3 in which the adhesive which comprises a 2nd adhesion layer is pattern-coated.

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