JP4508889B2 - Absorbent articles - Google Patents

Description

  The present invention relates to absorbent articles such as sanitary napkins, panty liners, cage sheets, and incontinence pads.

  Among absorbent articles such as sanitary napkins, panty liners, and incontinence pads, those that can be stretched are known (see, for example, Patent Document 1). This absorbent article is flexible and is characterized by stretching and stretching together with the underwear.

  Moreover, the absorber which has a stretching property is also known (for example, refer patent document 2). In this absorbent body, a large number of material bodies made of a superabsorbent material and fiber fluff are two-dimensionally arranged between stretchable layers made of woven elastic yarn.

Japanese National Patent Publication No. 10-508225 JP-T-5-504699

  The absorbent article described in Patent Document 1 is assumed to expand and contract together with the underwear in a state where it is attached to the underwear. Absent. That is, it is not assumed that the body is stretched to a size suitable for each of the various body shapes of the user. In addition, no device is provided to prevent the absorption performance from being lowered when the absorbent article is elongated.

  When the absorbent body described in Patent Document 2 is stretched, a gap is generated between the material bodies involved in the absorption. Therefore, the liquid slips through the gaps, and the absorption performance is lowered as compared with before the extension.

  Therefore, the objective of this invention is providing the absorbent article which can eliminate the various fault which the prior art mentioned above has.

  The present invention provides an absorbent article having a stretchable absorbent body having a stretchable structure in which a large number of absorbent small lumps containing a superabsorbent polymer and fibers are dispersedly arranged in a three-dimensional manner, and having stretchability as a whole. This achieves the object.

  In addition, the present invention provides an absorbent article having extensibility, in which the absorption performance in a state of being stretched 150% in the longitudinal direction is not deteriorated as compared with the absorption performance before elongation.

  Furthermore, in the present invention, a superabsorbent polymer particle and a large number of absorbent small lumps containing fibers are dispersed and arranged in a three-dimensional manner in a web containing crimped fibers. It is to provide.

  Since the absorbent article of the present invention has extensibility, it can be freely stretched and worn according to the body shape of the user during use. Therefore, it is difficult for the user to feel uncomfortable during wearing. Moreover, it fits to a user's body and it is hard to produce a clearance gap, thereby preventing liquid leakage. Furthermore, since it has a relatively small shape before being extended, the individual packaging form becomes compact. In addition, if only one type of product is prepared, it is possible to cope with various body shapes of the user, and there is an advantage that it is not necessary to increase the number of product types excessively. When it has stretchability in addition to stretchability, the fit to the user's body is further improved. Moreover, since the size is reduced at the time of disposal, it can be disposed of in small groups.

  The present invention will be described below based on preferred embodiments with reference to the drawings. FIG. 1 is a partially broken perspective view of a sanitary napkin as an embodiment of the absorbent article of the present invention. The sanitary napkin 1 of the present embodiment has a vertically long shape, and a liquid-retaining absorption sheet interposed between a liquid-permeable top sheet 2, a liquid-impermeable back sheet 3, and both sheets 2 and 3. It has a body 4. The top sheet 2 and the back sheet 3 extend from both side edges and front and rear ends of the absorbent body 4, and are bonded and fixed by bonding means such as heat seal and hot melt pressure-sensitive adhesive at the extended portions. As a result, an all-round seal portion 5a is formed. Inside the all-round seal portion 5a, the top sheet 2, the back sheet 3, and the absorber 4 are joined and integrated by heat embossing, thereby forming a large number of dot-like joining portions 5b. .

  The napkin 1 has extensibility. It is preferable that the extensibility of the napkin 1 is expressed at least in the longitudinal direction, and in addition, it is also expressed in the width direction. When the napkin 1 can be stretched about 120% in the longitudinal direction without difficulty, it can be said that the napkin 1 has extensibility. It is advantageous that the napkin 1 has stretchability in addition to stretchability.

  In order for the napkin 1 to have extensibility, each member constituting the napkin 1 needs to have extensibility. That is, as for the surface sheet 2, the back surface sheet 3, and the absorber 4 used for this embodiment, all of them have extensibility.

  As the surface sheet 2 having extensibility, for example, a nonwoven fabric described in JP-A No. 2002-187228 related to the previous application of the present applicant can be used. This nonwoven fabric has at least a two-layer structure, and one layer contains latent crimpable fibers in a state where a coiled crimp is developed. This non-woven fabric has stretchability in addition to stretchability due to the inclusion of fibers with coiled crimps.

As the back sheet 3 having extensibility, for example, Novix (trade name) manufactured by Iwaki Glass Co., Ltd., a film that stretches several times (but does not shrink) in the length direction and width direction. I can use it. Moreover, a sheet having elasticity such as a film having a basis weight of about 30 g / m ^{2 made of} urethane resin can be used.

  As described in the background art section, it is possible to form an extensible absorber by various methods. However, if the conventional absorbent body having extensibility is left as it is, the thickness of the absorbent body when stretched becomes thin, and the absorption performance is lowered. This is because the decrease in the apparent thickness of the absorber is directly linked to the decrease in the absorption capacity of the absorber. Therefore, in order to prevent the absorption performance from deteriorating even when the absorber is elongated, it is necessary to devise a technique that does not lead to a decrease in the absorption capacity even if the thickness of the absorber is decreased. In other words, (a) it is possible to easily stretch the structure, and even if it is stretched, the structure is not destroyed. Therefore, in the present invention, an extensible material is used as a constituent material of the absorbent body (as a so-called carrier), and separately from this, a minute absorbent element having extremely high liquid absorption retention property is provided on the carrier body as a tertiary. Originally a large amount of dispersion is adopted.

  In the present embodiment, the absorbent body 4 includes a large number of absorbent small lumps (hereinafter also simply referred to as “small lumps”) made of superabsorbent polymer particles and fibers as the absorbent element. The small lumps are uniformly distributed in a three-dimensional manner in the absorbent body 4. And as an example of a specific means for the absorbent body 4 to exhibit extensibility, the present embodiment adopts a configuration in which a large number of small lumps are dispersedly arranged in a web containing crimped fibers. ing. That is, the web containing crimped fibers corresponds to the carrier described above. In the absorbent body 4 having such a configuration, the stretchability is developed in addition to the stretchability due to the stretch and shrinkage of the crimped fibers. From the point of balance between absorption performance and extensibility of the absorbent body 4, the weight ratio (the former: latter) of the small aggregate as the absorbent element and the crimped fiber as the carrier is 20:80 to 60:40 Preferably there is.

  When the absorbent body 4 of the present embodiment is viewed from the surface side (upper surface), a part of the absorbent element is hidden by the absorbent element existing above it in the state before extension, and is mainly upward when absorbing body fluid. Absorbing element present in the liquid absorbs and prevents liquid leakage. On the other hand, after the extension, the position of the absorption element moves in the horizontal direction in conjunction with the stretching of the carrier in the horizontal direction. As a result, the absorption element hidden below becomes a position where it can be seen from above, and participates in liquid absorption. In this way, when a sufficient amount of the absorbing element is present in the absorber 4, it is possible to ensure the absorption capacity according to a principle different from the apparent thickness (simple capacity) of the absorber 4.

  The small agglomerate as the absorbent element is formed by integrating the superabsorbent polymer particles and a large number of fibers due to mechanical entanglement and adhesiveness due to the wetness of the superabsorbent polymer. Keep.

  As a result, the absorbent body 4 as a whole has a double structure in which the fiber density around the superabsorbent polymer is overwhelmingly high, and the fiber density of the carrier on the outside is relatively very low. Form. Therefore, the absorbent body 4 of the present embodiment has a structure in which the capillary force increases toward the highly absorbent polymer, and has a structure in which the absorbed liquid can be quickly absorbed and retained by the polymer. Such a structure is clearly different from a simple mixture of superabsorbent polymer particles and fibers.

  Further, since the small lump itself does not stretch or contract as the absorbent body 4 (or carrier) stretches, its capillary structure does not change. On the other hand, since the structure of the absorbent body 4 (or carrier) is stretched by elongation, the fiber gap is expanded and the capillary force is reduced. In this case, since the small lump is entangled with the crimped fiber as the carrier, when the absorbent body 4 is extended, the small lump moves in conjunction with the extension. Therefore, the longer the absorbent body 4 is stretched, the larger the difference in capillary force between the small block body and the carrier body, and the liquid is more easily transferred to the polymer. As a result, the absorption performance of the entire absorbent body is improved.

  As an example of what is used in the present invention as a small lump, (a) a small lump 10a in which a large number of fibers 12 are bonded to particles 11 of a superabsorbent polymer shown in FIG. 2 (b) includes a small lump 10b in which the superabsorbent polymer particles 11 and the fibers 14 are incorporated in the coil 13 of the crimped fiber 13. Both the blob bodies of (A) and (B) were integrated by the stickiness that the superabsorbent polymer particles and fibers developed due to mechanical entanglement and / or wetness of the superabsorbent polymer. Is.

  2 (a), for example, after the superabsorbent polymer particles 11 and fibers 12 are mixed with a relatively small amount of water, the mixture is dried and pulverized to a predetermined size. Can be obtained. Specifically, an appropriate amount of water is sprayed while mixing and stirring 20 to 150 parts by weight of fibers with respect to 100 parts by weight of the superabsorbent polymer particles. The superabsorbent polymer particles become sticky with water, thereby adhering the fibers to the superabsorbent polymer particles. In addition, the superabsorbent polymer particles and fibers are mechanically entangled with each other by stirring. The mixture thus obtained is dried using a drying means such as an electric dryer. A small lump can be obtained by pulverizing the dried mixture to a predetermined size. It is preferable to use a hydrophilic fiber. It is particularly preferable to use pulp. In addition to hydrophilic fibers, a small amount of hydrophobic fibers may be used in combination.

  A small lump body 10b shown in FIG. 2 (b) includes a superabsorbent polymer particle 11 in a coil of a fiber 13 crimped in a coil shape, and further, if necessary, a hydrophilic fiber (for example, It is preferable to incorporate other fibers 14 such as pulp and cotton) and hydrophobic fibers. This shortens the distance between the fibers in the small lump, and the small lump becomes dense. As a result, the capillary force of the small block increases, and the drawability of the liquid into the small block increases.

  The blob 10b shown in (b) of FIG. 2 (b) is, for example, a dispersion of superabsorbent polymer particles 11 on a web including fibers that can be crimped and other fibers 14, and further if necessary. The composite obtained by spraying with water and drying is divided into a predetermined size and formed into small lumps, and heat is applied to the small lumps to crimp the fibers into a coil shape and into a coil shape. The particles 11 and the fibers 14 can be taken into the coil of the crimped fibers. Preferred examples of the fibers that can be crimped in a coil shape include latently crimped eccentric core-sheath composite fibers and side-by-side composite fibers. The latent crimpable fiber can be handled in the same manner as a conventional non-woven fabric fiber before being heated, and has a property that a coiled crimp is developed and contracted by heating at a predetermined temperature. It is. Specific examples thereof include those described in JP-A-9-296325 and Japanese Patent No. 2759331.

  In order to manufacture (b) the small lump 10b, specifically, first, a web is manufactured using fibers that can be crimped in a coil shape and, if necessary, hydrophilic fibers such as pulp. The ratio of the fiber that can be crimped to the coil and the hydrophilic fiber is preferably the former: the latter = 10: 0 to 4: 6 in weight ratio. The web is sprinkled with superabsorbent polymer particles and then divided into small lumps. Heat is applied to the blob. For heat application, drying by a dryer, blowing of hot air, irradiation with infrared rays, or the like is used. By applying heat, the crimpable fibers contained in the small mass are crimped into a coil shape. In this case, as described above, in the small mass, the crimpable fiber and other fibers such as pulp are uniformly mixed, and the particles of the superabsorbent polymer are dispersed. Therefore, crimp occurs in a state where these fibers and particles are involved. As a result, the crimped fiber is in a state in which other fibers and superabsorbent polymer particles are taken into the coil. In this manner, the small block (b) is obtained. Before dividing the web, a small amount of water is sprayed onto the web to bond the crimpable fiber or hydrophilic fiber with the superabsorbent polymer particles, and the composite obtained in this way May be dried and pre-combined in advance.

  It is preferable that the amount of the superabsorbent polymer sprayed in the production of (b) the small lump 10b is 10 to 50 parts by weight with respect to 100 parts by weight of the web. The amount of water sprayed is preferably several tens of parts by weight with respect to 100 parts by weight of the superabsorbent polymer particles. In any of the embodiments (a) and (b), the superabsorbent polymer may use a fibrous material instead of particles. The use of a fibrous superabsorbent polymer is advantageous in that entanglement with hydrophilic fibers or crimped fibers is likely to occur and separation of small lumps is unlikely to occur.

  Regardless of whether the small lump is in the above-mentioned (i) or (b) or any other form, the small lump has an average size of 5 mm or less, particularly 2 mm or less, especially 1.5 mm or less. It is preferable that it is small. This is because if the small lump is too large, it may be difficult to uniformly disperse it in the absorbent body 3 three-dimensionally. Although there is no restriction | limiting in particular in the minimum of the magnitude | size of a small lump, It is preferable that it is 0.2 mm, especially 0.3 mm, especially 0.5 mm. If the lower limit is this value, even if the absorbent body is elongated, adjacent small blocks are not excessively separated, and the absorption performance can be maintained. Moreover, the fall of the capillary force of the support body which exists between small aggregates which is easy to occur when an absorber is extended too much can also be prevented. Considering the above, the size of the small block is preferably 0.2 to 5 mm, particularly 0.3 to 2 mm, and particularly preferably 0.5 to 1.5 mm.

  As described above, when the absorbent body 4 has a structure in which a large number of small lumps are dispersed in a web containing crimped fibers, the absorbent body 4 is subjected to the following method (a) or (b). Is preferably manufactured by.

Method (a)
A small lump and latent crimpable fibers are used at a predetermined ratio, and both are deposited by the airlaid method to obtain a web. The ratio of the small lumps to the latent crimpable fibers is preferably the former: the latter = 20: 80 to 60:40 in terms of weight ratio from the viewpoint of the balance between the absorption performance and the extensibility of the absorbent body 4. As the latent crimpable fiber, a fiber that can be crimped into a coil shape that is used in the previously described blob (b) is preferably used. The entire surface of the obtained web is embossed. For embossing, ultrasonic embossing or heat embossing is used. The embossed pattern is preferably a discontinuous pattern such as a dot shape. Next, heat is applied to the embossed web to crimp the latent crimpable fibers. The web shrinks due to crimping. At this time, from the viewpoint of suppressing excessive shrinkage of the web, it is preferable to fix the peripheral edge of the web using a pin tenter or the like. In the absorbent body 4 obtained in this way, small lumps are arranged in a three-dimensional manner. The absorber 4 has not only extensibility but also stretchability.

Method (b)
A web containing latent crimpable fibers is made. A small lump is uniformly sprayed on the web. A web containing latent crimpable fibers is overlaid thereon. Further, the operation of spraying the small lumps and the overlapping of the webs is repeated once or twice or more to produce a web having a multilayer structure in which the layers of the small lumps are arranged between adjacent webs. The ratio between the small lumps and the latent crimpable fibers can be the same as in the above-described method (a). The same applies to the types of latent crimpable fibers. Next, the entire surface of the obtained web is embossed. Embossing can be performed in the same manner as in the above method (a). Thereafter, the absorber 4 is obtained in the same manner as in the method (a). In the absorbent body 4 thus obtained, small lumps are dispersedly arranged in a three-dimensional manner, similarly to the absorbent body obtained by the method (a). It also has stretchability as well as stretchability.

  In any of the methods (a) and (b), up to about 20% by weight of hydrophilic fibers may be mixed with the latent crimpable fibers. The hydrophilic fiber here refers to a fiber made of a hydrophilic material such as pulp or rayon, or a surface of a hydrophobic fiber made of a resin such as polyethylene terephthalate, polyethylene, or polypropylene, to be hydrophilized with a hydrophilizing agent. Also includes fiber. Among these, rayon is preferably used from the viewpoint of easy incorporation into the structure (good entanglement) and improved absorption performance.

Regardless of the production method, the absorbent body 4 preferably has a basis weight of 150 to 800 g / m ² , particularly 250 to 550 g / m ² .

  In the absorbent body 4, a large number of small lumps are dispersedly arranged in a web containing crimped fibers. The web carrying a large number of small lumps preferably satisfies the following conditions 1) to 3). 1) At least have extensibility. 2) Do not cause a drop in extensibility when wet. 3) Less absorbability.

  The decrease in extensibility of the above 2) is due to the occurrence of settling or softening of the fibers when wet, thereby causing entanglement and bonding of the fibers. The above 3) is a desirable condition from the viewpoint of preventing a significant decrease in absorption performance when the absorbent body 4 is elongated.

  Various synthetic fibers (for example, synthetic fibers made of polyethylene terephthalate, polyethylene, polypropylene, or a composite thereof) or crosslinked pulp in which the fibers constituting the web are three-dimensionally crimped to have extensibility and have been subjected to a hydrophilic treatment. If so, the above conditions 1) to 3) are easily satisfied. In particular, in order to impart sufficient stretchability to the absorbent body 4, it is more preferable that the web contains a large amount of crimped fibers. In the present embodiment, most preferably, the absorbent body 4 is configured by dispersing small blocks in a web made only of crimped fibers. However, as described above, it is possible to mix hydrophilic fibers within a range that does not impair extensibility.

  In the absorbent body 4, a large number of small lumps may be dispersedly arranged in a web containing crimped fibers, and these may be covered with a covering absorbent sheet. In order to impart extensibility to the absorbent body 4, it is preferable that the absorbent sheet is made of a stretchable material. Examples of stretchable materials include a synthetic fiber web made of polyethylene terephthalate, polyethylene, polypropylene, or a composite thereof, a non-woven fabric in which the web is embossed in a discrete pattern such as dots, and the web is heated by an air-through process. Examples include a bonded nonwoven fabric and a nonwoven fabric obtained by entanglement of the web by a spunlace manufacturing method. Moreover, the material which hydrophilized the foam material, such as a polyurethane foam and a polyethylene foam, is mentioned.

  In the absorbent body 4, small lumps are distributed and arranged in a three-dimensional manner. Therefore, not only when the absorbent body 4 is stretched, but also when the absorbent body 4 is viewed in a plan view in the stretched state, absorption is performed. In any position of the body 4, a small block is almost certainly present. Therefore, unlike the absorber disclosed in JP-T-5-504699 described in the background section, the absorber used in the present invention has a lower absorption performance in the stretched state than the absorption performance before the extension. Never do. Rather, when the distance between the small lumps is increased by stretching, gel blocking of the superabsorbent polymer is less likely to occur, and the absorption performance in the stretched state may be higher than the absorption performance before stretching. . By using this absorbent body 4, the napkin of the present embodiment is configured such that the absorption performance in a state where the napkin is stretched 150% in the longitudinal direction does not deteriorate compared to the absorption performance before stretching. Absorption performance here means comprehensive performance including various performances required for the absorber, such as liquid absorption capacity and absorption speed.

  In the napkin 1 of this embodiment, since all of the top sheet 2, the back sheet 3, and the absorber 4 have elasticity, the napkin 1 as a whole also has elasticity. In the napkin 1 having such elasticity, the napkin 1 is stretched 150% in the longitudinal direction, and the stretched state is maintained in an environment of 40 ° C. and 80% RH for 2 hours. It is preferable that the length of the absorbent article after 2 seconds is 130 to 150%, particularly 130 to 140% with respect to the length of the absorbent article before stretching. Further, the length of the absorbent article after 5 minutes is preferably 100 to 130%, particularly preferably 100 to 120% with respect to the length of the absorbent article before elongation. That is, it is preferable that the napkin 1 is not shrunk at the moment when it is removed from the shorts, but it is shrunk slowly. Thereby, when the napkin 1 fixed to the shorts in the extended state is removed from the shorts and discarded, the size thereof is slowly reduced. As a result, there is an advantage that the liquid is not squeezed out immediately after removal and the hands are not soiled, and the napkin 1 can be made small and discarded. The reason why the napkin 1 is contracted slowly is that heat of body temperature is applied to the fiber for a predetermined time by the wearing of the napkin 1, and the fiber is heat set thereby.

  In the napkin 1 of this embodiment, the adhesive (not shown) for fixing the napkin 1 to clothing is given to the surface of the back surface sheet 3. The pressure-sensitive adhesive is preferably made of a material having rubber elasticity, such as a styrene-butadiene-styrene (SBS) type or a styrene-ethylene-butadiene-styrene (SEBS) type hot melt pressure-sensitive adhesive. More preferably, it is advantageous to apply these hot melt adhesives in a discrete pattern such as a circle, a dot, or a polygon in order to stretch and stick the stretchable napkin 1. Similarly, it is advantageous in that it can be stretched and fixed together with underwear such as shorts.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, the range of this invention is not restrict | limited to the said embodiment. For example, in the above-described embodiment, the above-mentioned (i) and (b) are preferably used as the small mass, but the superabsorbent polymer and the fiber can be integrated to maintain the small mass. If it exists, a thing other than (I) and (B) can be used as the small block. For example, as long as a material having an appropriate particle diameter in the above-described range is used, a polymer in which a superabsorbent polymer and a fiber are integrated can be used as a small block.

  Moreover, in the said embodiment, although all of the surface sheet 2, the back surface sheet 3, and the absorber 4 had the elasticity, these members should just have the extensibility at the minimum. In addition, when the napkin 1 has a member other than these three members, for example, a sublayer sheet disposed between the topsheet 2 and the absorbent body 4, it is preferable that the sublayer sheet also has at least extensibility.

  Further, the absorbent article of the present invention is not limited to sanitary napkins, and can be similarly applied to other absorbent articles such as panty liners, cage sheets, and incontinence pads.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples. Prior to Examples, an example of manufacturing a small block will be described.

  Further, the absorbent article of the present invention is not limited to sanitary napkins, and can be similarly applied to other absorbent articles such as panty liners, cage sheets, and incontinence pads.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples. Prior to Examples, an example of manufacturing a small block will be described.

[Production Example 1]
1 g of Aquaric CA (trade name), a superabsorbent polymer manufactured by Nippon Shokubai Co., Ltd., was placed in a 200 ml beaker and sprayed with water using a glass rod while stirring. Further, 2 g of pulp was added, and stirring was continued with a glass rod while additional water was sprayed. The obtained mixture was taken out from the beaker and dried at 110 ° C. for 2 hours using an electric dryer. The dried mixture was pulverized to obtain a small mass shown in FIG. The average size of the small lumps was 1 mm, and even a large one was about 2 mm.

[Production Example 2]
Latent crimped fibers that can be crimped into a coil shape (CPP fiber (trade name) manufactured by Daiwa Spinning Co., Ltd., fiber diameter 2.4 dtex, fiber length 51 mm) 2 g and pulp 2 g are mixed and then opened using a card machine. I got the web. On this web, 1 g of Aquaric CA (trade name), which is a superabsorbent polymer manufactured by Nippon Shokubai Co., Ltd., was uniformly sprayed over the entire web. On top of that, ion-exchanged water was appropriately sprayed and dried naturally. The obtained composite was divided into about 0.05 g pieces to form about 100 small lumps. The blob was heated in an electric dryer at 130 ° C. for 30 seconds. The latent crimp fiber contained in the small blob was crimped by heating. The fibers crimped into a coil were in a state where pulp and superabsorbent polymer particles were taken into the coil. In this way, a small block as shown in FIG. 2B was obtained. The average size of the small blocks was 0.8 mm, and even a large one was about 2 mm.

[Production Example 3]
By crushing, a small lump was obtained in the same manner as in Production Example 1 except that the average size of the small lump was 2 mm and the large lump was adjusted to about 5 mm.

[Production Example 4]
By crushing, the size of the small lump was 0.6 mm on average, and a small lump was obtained in the same manner as in Production Example 1 except that the small lump was adjusted to about 1.5 mm.

[Production Example 5]
1 g of Aquaric CA (trade name), a superabsorbent polymer manufactured by Nippon Shokubai Co., Ltd., was placed in a 200 ml beaker and sprayed with water using a glass rod while stirring. Further, 0.5 g of pulp was added, and stirring was continued with a glass rod while additional water was sprayed. The obtained mixture was taken out from the beaker and dried at 110 ° C. for 2 hours using an electric dryer. The dried mixture was pulverized to obtain a small mass shown in FIG. The size of the small block was on average 0.3 mm, and even a large one was about 0.5 mm.

[Reference Example 1 for comparison]
As an absorbent element, Aqualic CA (trade name), which is a superabsorbent polymer manufactured by Nippon Shokubai Co., Ltd., was used. The average particle size of this polymer was 0.16 mm, and even a large one was 0.35 mm.

[Measurement method of the size of the small block]
The 25 small lumps were appropriately selected, and the diameter was measured with an Olympus microscope SZH-10 connected by CRT with a CCD. At this time, the scale on the screen is measured and determined in advance using an objective micrometer manufactured by Elma Co., Ltd. (Factory No. 422, 1/100 mm). The measurement is performed with the average value and the maximum value of the selected 25 grains. Depending on the granulation method including the production example 2, the grains become non-uniform. In some cases, the fiber may protrude from the grain. In this case, the maximum diameter including the fiber was measured, and the maximum value and the number average value were used as representative values.

[Example 1]
(1) Manufacture of Absorber 1.5 g of the small lump obtained in Production Example 1 and 4 g of latent crimped fiber [CPP fiber (trade name) manufactured by Daiwa Spinning Co., Ltd.] that can be coiled are simultaneously produced by the airlaid method. The web was deposited to have a width of 15 cm × length of 30 cm and a basis weight of 122 g / m ² . This web was subjected to ultrasonic embossing of a dot pattern. The embossed web was fixed with a pin tenter so as to have a width of 10 cm and a length of 20 cm, and heated at 110 ° C. for 30 seconds. The latent crimp fiber contained in the web was crimped into a coil shape by heating. Thus, an elastic body (FIG. 3) having a basis weight of 275 g / m ² having elasticity was obtained.

(2) Production of surface sheet A web having a basis weight of 12 g / m ² was produced using a thermoplastic conjugate fiber [SH (trade name) manufactured by Daiwa Boshoku Co., Ltd.] as a raw material using a card machine. This was used as the upper layer. This fiber was made of polyethylene terephthalate in the core and polyethylene in the sheath, and was two-dimensionally crimped.

Separately from this, a latent crimped fiber (CPP fiber (trade name) manufactured by Daiwa Spinning Co., Ltd.) that can be crimped in a coil shape was used as a raw material, and a web having a basis weight of 17 g / m ² was produced using a card machine. This was used as the lower layer.

The upper layer and the lower layer were overlapped and partially joined by ultrasonic embossing. The joint was circular and formed a rhombus lattice pattern as a whole. After joining the two, hot air of 130 ° C. ± 10 ° C. is allowed to pass for 5 to 10 seconds by an air-through method, crimping the underlying latent crimped fibers in a coil shape to shrink the lower layer and projecting the upper layer between the joints A nonwoven fabric having a basis weight of 58 g / m ² having a large number of protrusions was produced. The nonwoven fabric having elasticity obtained as described above was used as a surface sheet.

(3) Manufacture of Back Sheet A pellet “Flekkmer” manufactured by Nippon Synthetic Resin Co., Ltd. was melt-extruded to obtain a film having a basis weight of 20 g / m ² . The film was transparent and stretchable, and had a moisture permeability of 2.0 g / (100 cm ² · 24 hr).

(4) Manufacture of napkin The back sheet, the absorbent body and the top sheet are overlapped in this order, and the entire seal part 5a shown in FIG. 1 is formed by heat sealing, and the dot-like joint shown in FIG. 1 by ultrasonic embossing. Many 5b were formed. Next, trimming was performed on the outside of the all-round seal portion 5a to obtain a napkin shown in FIG. The absorber was 12 cm long and 5 cm wide. The total length of the napkin was 14 cm and the width was 6.5 cm. Further, a hot melt pressure-sensitive adhesive was applied to the surface of the back sheet of the napkin in a circular dot pattern having a diameter of 3 mm.

[Example 2]
A latently crimped fiber that can be crimped into a coil shape [CPP fiber (trade name) manufactured by Daiwa Spinning Co., Ltd.] as a raw material, using a card machine and having a width of 30 cm × length of 45 cm and a basis weight of 7.4 g / m ² I got the web. On this web, 1 g of the small block obtained in Production Example 2 was uniformly dispersed. The same web was overlaid on top of it. The operation of spraying the small lumps and overlapping the webs was repeated two more times to obtain a web having a multilayer structure composed of four layers of webs and three layers of small lumps located between the webs. . This web was subjected to ultrasonic embossing of a dot pattern. The embossed web was fixed with a pin tenter so as to have a width of 10 cm and a length of 20 cm, and heated at 110 ° C. for 30 seconds. The latent crimp fiber contained in the web was crimped into a coil shape by heating. Thus, an elastic body (FIG. 4) having a basis weight of about 350 g / m ² having elasticity was obtained. Except for this, the napkin shown in FIG. 1 was obtained in the same manner as in Example 1. The absorber was 12 cm long and 5 cm wide. The total length of the napkin was 14 cm and the width was 6.5 cm.

Example 3
A napkin shown in FIG. 1 was obtained in the same manner as in Example 2 except that the small mass obtained in Production Example 3 was used.

Example 4
A napkin shown in FIG. 1 was obtained in the same manner as in Example 2 except that the small mass obtained in Production Example 4 was used.

Example 5
A napkin shown in FIG. 1 was obtained in the same manner as in Example 2 except that the small mass obtained in Production Example 5 was used.

[Comparative Example 1]
An absorbent body was obtained in the same manner as in Example 2 using the superabsorbent polymer of Reference Example 1 for comparison instead of the small block. This absorber is in the form shown in FIG. Except for this, the napkin shown in FIG. 1 was obtained in the same manner as in Example 1.

[Comparative Example 2]
Using 1 g of pulp as a raw material, this was deposited by the airlaid method to obtain a web having a width of 30 cm × a length of 45 cm and a basis weight of 7.4 g / m ² . On this web, 1 g of the small block obtained in Production Example 1 was uniformly dispersed. The same web was overlaid on top of it. The operation of spraying the small lumps and overlapping the webs was repeated two more times to obtain a web having a multilayer structure composed of four layers of webs and three layers of small lumps located between the webs. . Using this web, a napkin shown in FIG. 1 was obtained in the same manner as in Example 1.

[Performance evaluation]
About the napkin obtained by each Example and the comparative example, (1) Absorption amount at the time of standard time and expansion | extension, (2) Napkin full length after 20 second and 5 minutes was measured with the following method.
・ Standard time and absorption amount at the time of extension: After attaching the napkin to the shorts as it is, the shorts were attached to the female model. While walking the female model at 100 steps / minute, 1 g of equine defibrinated blood was injected into the napkin every minute, and the model was allowed to walk until it leaked.
When stretched: The same as the standard time except that the napkin was stretched 150% in the longitudinal direction and stuck to the shorts.
Each of the three points is evaluated, and the average value of the injected liquid amount until leakage is taken as the absorption amount.
-Total length of napkin after 20 seconds and 5 minutes The napkin was stretched 150% on a 2 mm thick PVC plate, and the front and rear ends were fixed with adhesive tape. At this time, the hot-melt pressure-sensitive adhesive applied to the surface of the back sheet was not adhered to the PVC plate. After leaving the napkin in an environment of 40 ° C. and 80% RH for 2 hours, the napkin was peeled off from the PVC plate, and the total length after 20 seconds and 5 minutes was measured.
Each of the three points was measured, and the average value was defined as the total length of the napkin.

As is apparent from the evaluation results of the absorption amount in Table 1, the napkin of each example can be extended by 150%, and the absorption amount at that time is equal to or higher than the absorption amount at the standard time. I understand that. On the other hand, in the napkin of the comparative example 1 provided with the absorber which does not have a small lump body, it turns out that the absorbed amount at the time of expansion | extension falls. In addition, the normal commercially available napkin was impossible to elongate the napkin itself.
As is clear from the evaluation results of the total length of the napkin in Table 1, when the napkin of each example is placed in the wearing environment in the extended state after the napkin is released after being extended, it slowly contracts to the original size. You can see that

It is a partially broken perspective view which shows the sanitary napkin as one Embodiment of the absorbent article of this invention. It is a schematic diagram which shows the structure of a small lump-like body. 2 is a schematic diagram showing the structure of an absorbent body obtained in Example 1. FIG. 6 is a schematic diagram showing a structure of an absorbent body obtained in Example 2. FIG. 4 is a schematic diagram showing the structure of an absorbent body obtained in Comparative Example 1. FIG.

Explanation of symbols

1 Sanitary napkin (absorbent article)
2 Top sheet 3 Back sheet 4 Absorber 10a, 10b Small body 11 Superabsorbent polymer particle 12 Fiber 13 Coiled fiber 14 Other fiber

Claims (5)

A large number of absorptive lumps in which a superabsorbent polymer and fibers are incorporated in the coil of the crimped fiber are dispersed in a three-dimensional manner in the web containing the crimped fiber. An absorbent article comprising an absorbent body, the absorbent article having extensibility as a whole.   The absorbent article according to claim 1, wherein the absorbent body further has stretchability. The small mass is obtained by spreading a composite obtained by dispersing particles of superabsorbent polymer on a web containing fibers that can be crimped in a coil shape and other fibers, spraying water, and then drying. Divided into sizes to form small lumps, heat is applied to the small lumps to crimp the crimpable fibers into a coil shape, and the superabsorbent in the coil of the fibers crimped into a coil shape The absorbent article according to claim 1 or 2, wherein the absorbent article is obtained by incorporating polymer particles and the other fibers. The absorptive article according to any one of claims 1 to 3 whose weight ratio (the former: latter) of said small lump and said crimped fiber is 20: 80-60: 40. The absorbent article according to any one of claims 1 to 4, wherein the small aggregates have an average size of 0.2 to 5 mm.