JP3175871B2 - Sanitary napkin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sanitary napkin excellent in wearability.

[0002]

2. Description of the Related Art A sanitary napkin having side flaps has a function of stably fixing the napkin to a crotch portion of shorts by its side flaps. The shorts are considered to have an effect that is unlikely to be soiled, and have been awarded as giving psychological security to the wearer regardless of whether or not the effect is actually exerted.

A representative publication describing a sanitary napkin having a side flap is disclosed in
JP-A-75058 and JP-A-64-70050, etc., and the flap of the conventional sanitary napkin described therein is formed by integrating a back sheet and a top sheet.

[0004]

However, the above-mentioned conventional sanitary napkins have the following drawbacks 1) to 3). 1) The excrement may enter between the top sheet and the back sheet of the flap part. 2) The strength of the flap part is low and it stretches or tears when worn. 3) Since the flap is thin, noise due to friction is likely to occur during mounting. That is, the sanitary napkin having the conventional flap has a problem that it is inferior in the liquid leakage preventing property and the wearing property.

Accordingly, an object of the present invention is to provide a liquid leakage preventing property,
An object of the present invention is to provide a sanitary napkin excellent in flap strength, wearability and wearing feeling.

[0006]

As a result of various studies, the present inventors have found that a sanitary napkin having a flap composed of a film formed from a material having a specific resin density to a specific basis weight has achieved the above object. It was found that it could be done.

The present invention has been made based on the above findings, and has flaps extending from both sides of a central absorbent body formed of a liquid-impermeable backsheet, an absorbent and a liquid-permeable topsheet. In a sanitary napkin having
The flap has a resin density of 0.910 to 0.940 g /
basis weight 30 formed by a polyethylene resin cm ³
Table Do Ri, and the flap of the film of 90 g / m ²
The surface is recessed by embossing to a height of 0.05 to 1 mm.
An object of the present invention is to provide a sanitary napkin characterized in that projections are formed at a density of 10 to 100 .

[0008]

According to the sanitary napkin of the present invention, the central absorbent portion is fixed at a predetermined position on the inner surface of the crotch portion of the shorts,
The flap is folded so as to be sandwiched between the shorts, and the flap is fixed and attached to the outer surface of the crotch portion of the shorts. In addition, the sanitary napkin of the present invention is easy to be mounted due to the volume feeling between the back sheet and the flap, the noise due to friction during the mounting is small, the slip is prevented by the frictional force of the flap portion, and the flow of excrement is prevented.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The sanitary napkin of the present invention will be described below in detail with reference to the accompanying drawings, and the present invention will be specifically described with reference to test examples. However, the present invention is not limited to these. is not.

FIG. 1 is a perspective view of a sanitary napkin showing one embodiment of the present invention, and FIG. 2 is a cross-sectional view showing a state of II ′ in a state in which the sanitary napkin shown in FIG. 1 is mounted on shorts. It is.

As shown in FIGS. 1 and 2, a sanitary napkin 30 of the present embodiment has a central absorbent body formed of a liquid-impermeable back sheet 2, an absorbent body 3 and a liquid-permeable top sheet 1. It has flaps 20 extending from both sides of the part 10. The flap 20 has a resin density of 0.91.
Ri Do from the film of 0~0.940g / cm basis weight formed by a polyethylene resin of ^{3 30~90g} / m ^2,
In addition, the surface of the flap is embossed,
Asperities 6 of 0.05 to 1 mm are formed at a density of 10 to 100
Have been .

More specifically, the central absorbent portion 10 of the sanitary napkin 30 of this embodiment wraps the absorbent body 3 with the top sheet 1 as shown in FIGS. And the back sheet 2 are adhered to each other with an adhesive. here,
A plurality of openings 11 for liquid permeation are provided in the central region A of the top sheet 1, and the side edge region B is a liquid impermeable portion so as not to cause liquid leakage. Total aperture surface of the aperture 11
Products are restricted from liquid permeable and liquid return-preventing property, since the smaller inferior substantially liquid-permeable, sheet formation is poor according Meanwhile increases, the opening speed of the open hole 11
Is preferably in the range of 10 pieces / cm ^{2 to} 100 pieces / cm ² in consideration of the above, and 30 pieces / cm ^{2 to} 60 pieces / cm ^2.
Is more preferably in the range of

An adhesive layer 4 is provided on a portion of the back surface of the back sheet 2 opposite to the central absorbent portion 10, and a release sheet (not shown) is provided on the surface of the adhesive layer 4. Is affixed. In addition, the flap 20 is formed by extending the backsheet 2 outwardly from both side edges of the central absorber 10 near the center in the longitudinal direction of the central absorber 10, and further, The flap 20
An adhesive layer 5 is provided on the back surface side of the substrate, and a release sheet (not shown) is adhered to the surface of the adhesive layer 5.

Further, the backsheet 2 and the flap 20 are formed with irregularities 6 (the irregularities of the backsheet 2 are not shown) by embossing the surface, and have characteristics in terms of mounting properties and appearance. I'm making it. Various patterns such as straight lines, turtle shells, textures, and pinpoints can be formed by the embossing process. For example, the shape of the irregularities 6 formed by the pinpoint pattern is 0.05 to 1 mm in height. , <br/> Oh Ru at a density 10 to 100 / cm ^2.

The raw materials of the back sheet 2, top sheet 1 and absorbent body 3 used for the sanitary napkin 30 of this embodiment are not particularly limited, and those used for ordinary sanitary napkins are used. For example, the following materials are used.

Examples of the material of the back sheet 2 include polyolefins, copolymers of olefins with other vinyl monomers such as acrylates and vinyl acetate, and hydrophobic thermoplastic resins such as polyester, polyamide and polymer blends. Among them, among these, from the viewpoint of texture and handling, a copolymer of polyolefin or olefin and another vinyl monomer, or a hydrophobic thermoplastic resin of a polymer blend type is preferably used, and when used, alone or as a mixture. Can be used. In this embodiment, the back sheet 20 is made of poly
Ethylene resin is used. Then, by molding the hydrophobic thermoplastic resin, the equal and the resulting film into a sheet, it can be used as the above-mentioned back sheet 2. Further, it is preferable that an inorganic filler such as TiO ₂ or talc is internally added to the hydrophobic thermoplastic resin to suppress the covering property and the surface stickiness of the obtained film. Further, the film composed of a laminated sheet formed by using two or more of the above sheets is the back sheet 2 of the present invention.
And a, it can be particularly preferably used.

Further, as the material of the top sheet 1, it is possible to use the same material as the upper <br/> Symbol backsheet 2 material. When a liquid-impermeable sheet formed of the above-mentioned hydrophobic thermoplastic resin or the like is used as the top sheet 1, the top sheet 1 is opened at the central region A (skin contact portion) as described above. It is formed by a perforated plastic film having holes.

The absorbent 3 is preferably composed mainly of defibrated pulp and used in combination with a high-molecular water-absorbing polymer.
In addition, those obtained by heat-treating a mixture of a thermoplastic resin, cellulose fibers, and a high-molecular-weight water-absorbing polymer are preferable. The high-molecular-weight water-absorbing polymer may be a mixture with pulp, and the high-molecular-weight water-absorbing polymer has a holding performance of absorbing and holding a liquid 20 times or more its own weight, and has a gelling property. The high-molecular-weight water-absorbing polymer is preferably starch-acrylic acid (salt).
Preferred are a graft copolymer, a saponified starch-acrylonitrile copolymer, a crosslinked product of sodium carboxymethyl cellulose, an acrylic acid (salt) polymer, and the like.

[0019] Subsequently explained is a characteristic portion of the sanitary napkin 30 of the present embodiment, the sanitary napkin 30 of the present embodiment, the flap 20 is, trees fat density 0.91
0 to 0.940 g / cm ³ , preferably 0.920 to
A basis weight of 30 to 90 g / m ² , preferably 40 to 80 g / m ² formed by a 0.935 g / cm ³ polyethylene resin
Ri Do from the film of the m ^2, and the surface of the flap, et
By the embossing process, unevenness 6 with a height of 0.05 to 1 mm is dense.
It is formed at 10 to 100 degrees .

The polyethylene resin has a resin density of 0.
When it is less than 910 g / cm ³ , the strength of the flap is low,
Easily stretches and tears when worn, and 0.940g
If it exceeds / cm ³ , it gives an uncomfortable feeling such as stiffness when worn, and it is difficult to bend the flap due to its rigidity, and it is easy to come off the shorts.

On the other hand, if the basis weight is less than 30 g / m ² , a feeling of being unreliable at the time of wearing is given, and since the strength is low, the flap is easily stretched at the time of fixing to shorts or at the time of wearing. If it exceeds m ² , a feeling of stiffness is given at the time of mounting, and since the rigidity of the flap is high, inconveniences such as difficulty in bending the flap and detaching from the shorts are caused.

[0022] In addition, by extending the back sheet and the top sheet a flap, formed by polymerization of both sheets place
If, the flaps formed by the two sheets are polyethylene
As long as the sheet is made of a ethylene resin and has a basis weight and a resin density within the above ranges, the basis weight and the resin density of each of the two sheets may be outside the above ranges.

Then, the sanitary napkin 30 of this embodiment is used.
Has the above-described configuration, and particularly has the above-described features, and thus has the following effects. The back sheet and the flap are embossed and have irregularities on the surface, so that they have an excellent tactile sensation and have a characteristic appearance. Since the back sheet has a moderate volume feeling, it is easy to wear and the noise due to friction during wearing is small, and the thickness and flexibility are similar to underwear, so there is no discomfort in wearing. Since the back sheet is embossed and has irregularities, the slip is prevented by the frictional force of the film, and the excrement is prevented from flowing. Since the resin density of the polyethylene resin used for the film forming the back sheet and the flap is within the above-described range, the flap strength is increased, the waist has an appropriate waist, a feeling, and the conveyance at the time of manufacturing is easy. is there.

In order to use the sanitary napkin 30 of this embodiment, after peeling off the release tape, as shown in FIG. 2, the adhesive layer 4 of the back sheet 2 is placed on the skin contact portion of the shorts 7 and It can be used by bending the flap portion 20 along the thickness of the crotch portion of the shorts 7 and attaching and fixing the adhesive layer 5 on the back surface of the flap portion 20 to the surface of the shorts 7.

The sanitary napkin of the present invention is not limited to the above-described embodiment. For example, in the present embodiment, the backsheet and the flap are integrally formed. The backsheet and the flap may be formed separately.

Next, the present invention will be described more specifically based on test examples. Test Example 1 50 parts by weight of a linear low-density polyethylene resin (“UZ25100J”, manufactured by Mitsui Petrochemical Industries, Ltd.) having a resin density of 0.925 g / cm ³ and a melt index of 10 g / 10 minutes, and a resin The density is 0.918g / cm
^3. Low density polyethylene having a melt index of 2.0 g / 10 minutes (“M27”, Mitsui Petrochemical Industry Co., Ltd.)
50 parts by weight) and TiO ₂ 8.4 as an inorganic filler
Parts by weight with a Henschel mixer, and extruded to form a film with a sheet forming machine. Then, the film was roughened with a satin pattern, and then embossed to obtain a basis weight of 50.
g / m ² of film was obtained. The melt index was 190 ° C. according to ASTM D1238 and the load was 2.
The resin output is 16 kg and the resin density is ASTM D
It is determined by a density gradient tube in accordance with 1505.

[Test Example 2] The resin density was 0.925 g / cm.
^3. Test 100 parts by weight of a linear low-density polyethylene resin (“UZ25100J”, manufactured by Mitsui Petrochemical Industry Co., Ltd.) having a melt index of 10 g / 10 min, and 8.4 parts by weight of TiO _{2 as} an inorganic filler. By treating in the same manner as in Example 1, a film having a basis weight of 50 g / m ² was obtained.

Test Example 3 The density was 0.909 g / cm ³ ,
100 parts by weight of a low-density polyethylene resin (“C-2499”, manufactured by Mitsui Petrochemical Industries, Ltd.) having a melt index of 4.0 g / 10 minutes, and TiO as an inorganic filler
₂ 8.4 parts by weight was treated in the same manner as in Test Example 1 to obtain a basis weight of 5
A film of 0 g / m ² was obtained.

[Test Example 4] The resin density was 0.945 g / cm.
^3. 100 parts by weight of a medium-density polyethylene resin (“NZ45200” manufactured by Mitsui Petrochemical Industries, Ltd.) having a melt index of 20 g / 10 minutes, and T as an inorganic filler
8.4 parts by weight of iO ₂ was treated in the same manner as in Test Example 1 to obtain a film having a basis weight of 50 g / m ² .

[Test Example 5] The resin density was 0.925 g / cm.
^3. 50 parts by weight of a linear low-density polyethylene resin (“UZ25100J”, manufactured by Mitsui Petrochemical Industries, Ltd.) having a melt index of 10 g / 10 min, and a resin density of 0.
918 g / cm ³ , melt index 2.0 g / 10
50 parts by weight of a low-density polyethylene resin (“M27”, manufactured by Mitsui Petrochemical Industries, Ltd.) and 8.4 parts by weight of TiO _{2 as} an inorganic filler were treated in the same manner as in Test Example 1 to obtain A film with an amount of 25 g / m ² was obtained.

Test Example 6 A film having a basis weight of 100 g / m ² was obtained by treating in the same manner as in Test Example 1 with the same formulation as in Test Example 5.

A back sheet and a flap were formed from the film prepared in each of the above test examples, and a sanitary napkin shown in FIG. 1 was prepared. Then, a functional evaluation was performed to determine whether or not the function for the flap was satisfied. Table 1 shows the results.

The above function evaluation was a sensory evaluation when a woman wore a sanitary napkin with a flap made of each film, and was performed as follows.・ Napkin flap part is good without discomfort ... ・ ◎ ・ Napkin flap part has little discomfort and is good ... ・ ○ ・ Napkin flap part has some discomfort ... ・ ・ △・ It feels somewhat hard or somewhat unreliable. ・ There is a sense of incongruity as the flap of the napkin .... ×× (hard or unreliable)

[0034]

[Table 1]

As is clear from the results shown in Table 1, it is understood that the sanitary napkin having the flap formed of the films of Test Examples 1 and 2 satisfies the function as the flap portion of the sanitary napkin. Therefore, in order to form a flap portion having an appropriate texture and film strength, in particular, the resin density of the polyethylene resin is set to 0.910 g.
/ Cm ^{3 to} 0.940 g / cm ³ , basis weight 30 g / m ^{2 to} 9
It is necessary to be within a range of 0 g / m ² , and if it is within the above range, it can be understood that the function as a flap portion of the sanitary napkin can be satisfied.

As is clear from the results shown in Table 1, as in Test Examples 3 and 4, the resin density of the polyethylene resin of the film forming the flap portion was 0.91.
If it is less than 0 g / cm ³ , the flap is too soft and the strength is low, and if it is more than 0.940 g / cm ³ , it feels hard, and even if it is within the above-mentioned density range as in Test Examples 5 and 6, If the basis weight is less than 30 g / m ² , the flap cannot be relied on, and the strength is low. If the basis weight is more than 90 g / m ² , the feeling of wearing is poor and the rigidity of the flap is high. Is not satisfactory.

[0037]

The sanitary napkin of the present invention is excellent in the prevention of liquid leakage, the strength of the flap portion, the ease of wearing and the feeling of wearing, and specifically has the following effects. Since the back sheet and the flap are embossed and have irregularities on the surface, they have an excellent tactile sensation and have a characteristic appearance. Since the back sheet has a moderate volume feeling, it is easy to wear and the noise due to friction during wearing is small, and the thickness and flexibility are similar to underwear, so there is no discomfort in wearing. Since the back sheet has irregularities due to the embossing treatment, the slip is prevented by the frictional force of the film, and the flow of excrement is prevented. Since the resin density of the polyethylene resin of the film forming the back sheet and the flap is in a specific range, the flap strength is increased, the waist has a moderate waist and a feeling, and the conveyance at the time of manufacturing is easy.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a sanitary napkin of the present invention.

FIG. 2 is a cross-sectional view showing a state of II ′ in a mode in which the sanitary napkin shown in FIG. 1 is mounted on shorts.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Top sheet 2 Back sheet 3 Absorber 4 Adhesive layer 5 Adhesive layer 6 Irregularity 7 Shorts 10 Central absorber 11 Opening 20 Flap 30 Sanitary napkin A Central area B Side edge area

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-179307 (JP, A) JP-A-61-170458 (JP, A) JP-A-60-80450 (JP, A) JP-A-60-180 185803 (JP, A) JP-A-2-193664 (JP, A) JP-A-60-181301 (JP, A) JP-A-60-75058 (JP, A) JP-A-4-212356 (JP, A) Hira 4-88932 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) A61F 13/15-13/84

Claims (3)

(57) [Claims] 1. A sanitary napkin having flaps extending from both sides of a central absorbent portion formed of a liquid-impermeable backsheet, an absorbent and a liquid-permeable topsheet, wherein the flap is made of a resin. Density 0.910 to 0.940 g /
basis weight 30 formed by a polyethylene resin cm ³
Table Do Ri, and the flap of the film of 90 g / m ²
The surface is recessed by embossing to a height of 0.05 to 1 mm.
A sanitary napkin, wherein the protrusions are formed at a density of 10 to 100 . 2. The sanitary napkin according to claim 1, wherein said flap is formed of a mixture of two or more resins. 3. The sanitary napkin according to claim 1, wherein the flap is formed by extending the back sheet.