JP2018161241A - Absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorber which can achieve both of thickness reduction and improvement of liquid absorption property.SOLUTION: There is provided an absorber which has a base material sheet having plural belt-like parts, in which a liquid absorptive composite material which includes a junction base part including on a surface of a water absorptive polymer material, a thermofusion resin component, is fastened to the belt-like parts through the junction base part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an absorbent body used for absorbent articles such as diapers and sanitary napkins.

Several proposals have been made on the absorbent body disposed in the absorbent article from the viewpoint of improving the absorbability and the wearability of the absorbent article.
For example, Patent Document 1 describes a composite in which a water-absorbing sodium polyacrylate resin and hydrophilic fiber powder are directly bonded. In the composite, the hydrophilic fiber powder prevents contact between the water-absorbing sodium polyacrylate resins and prevents gel blocking during water absorption. Patent Document 2 describes a composite absorbent material in which a part of fibers is embedded in a water-insoluble water-absorbent resin from the viewpoint of eliminating the dropping of the water-absorbing polymer and increasing the contact efficiency with the liquid.
Patent Document 3 describes an absorbent body including an excretory part slit region and a central slit region in which vertical slits are dispersed from the viewpoint of enhancing the wearing feeling of an absorbent article having a wing part. Patent Document 4 describes an absorbent body in which four or more rows of slits are arranged at intervals from the viewpoint of reducing the rigidity of the absorbent body and improving the absorbability.

Japanese Patent Laying-Open No. 2015-71125 Japanese Unexamined Patent Publication No. 63-73958 JP2015-42244A Japanese Utility Model Publication No. 63-18122

In the absorbent article, in order to meet the demand for further thinning, it is required to make the absorber thinner. Therefore, an attempt has been made to secure the absorption performance with a water-absorbing polymer material (surface-crosslinked polymer material called SAP) and to reduce the amount of bulky pulp fibers to the limit.
The thinning of the absorbent body contributes to an improvement in wearing feeling by improving the softness of the absorbent article, and further creates a natural appearance such that the wearing of the absorbent article is not noticed from the outside of the clothing. However, if the absorber is further reduced in thickness, further increase in the density of the water-absorbing polymer material is inevitable. Since the water-absorbing polymer material gels when it swells due to water absorption, it forms a gel layer first on the side close to the liquid receiving surface, and subsequent liquid permeation and inhibition of diffusion (gel blocking) are likely to occur. Thereby, the fluid permeability of the liquid in the absorbent body is inhibited, and the liquid absorption rate may be reduced. As described above, there is a problem that improvement in wearing feeling due to thinning and improvement in liquid absorption speed cannot always be achieved. In any of Patent Documents 1 to 4, there is no description of a technique that achieves both reduction in thickness of an absorbent body using a water-absorbing polymer material and improvement in liquid absorbency.

  In consideration of the above problems, the present invention relates to an absorber that can achieve both reduction in thickness of the absorber and improvement in liquid absorbency.

  The present invention includes a base sheet having a plurality of strip-shaped portions, and a liquid-absorbing composite material having a bonding base portion including a heat-meltable resin component on the surface of the water-absorbing polymer material is provided in the strip-shaped portion. An absorber is provided which is secured via a bonding base.

  The absorber of the present invention can achieve both reduction in thickness of the absorber and improvement in liquid absorbency.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows typically preferable embodiment of the absorber which concerns on this invention as a state before liquid absorption, and the figure in the circle | round | yen shown with the code | symbol P is typical about the adhering state to the fiber of a liquid absorptive composite material. FIG. FIG. 2 is a cross-sectional view schematically showing a part of a cross section in a direction orthogonal to a longitudinal direction of a belt-like portion in the absorbent body before liquid absorption shown in FIG. 1. It is sectional drawing which shows typically the state which the water absorbing polymer material which comprises a liquid absorptive composite material absorbed the liquid, and swollen about the cross section shown in FIG. In the absorber before liquid absorption shown in FIG. 1, it is explanatory drawing which shows typically the state by which the liquid absorptive composite material is adhering to the raising fiber of a base material sheet.

  Hereinafter, the absorber of the present invention is explained based on a desirable embodiment with reference to drawings. In addition, it is preferable to apply the absorbent body of the present invention as a liquid holding part of absorbent articles such as sanitary napkins and diapers for infants and adults. However, the absorber of the present invention is not limited to this.

  As shown in FIG. 1, the absorbent body 10 of the present embodiment includes a base sheet 4 and a liquid-absorbing composite material 3 having a bonding base portion 2 containing a heat-meltable resin component on the surface of the water-absorbing polymer material 1. Have In addition, in FIG. 1, the liquid absorptive composite material 3 is shown typically, and the magnitude | size, the number, and arrangement | positioning pattern of the liquid absorptive composite material 3 are not limited to what was shown in FIG.

  Examples of the base sheet 4 include paper, non-woven fabric, cloth, film, synthetic sponge formed by foaming synthetic resin, etc. Among them, even if it is thin, the tensile strength is relatively high, and it is thin and flexible. From the viewpoint of imparting, a nonwoven fabric is preferably used. As the non-woven fabric, a hydrophilic non-woven fabric is preferable, and a hydrophilic non-woven fabric including a hydrophilic fiber as a constituent fiber, a hydrophilic non-woven fabric including a synthetic fiber imparted with hydrophilicity as a constituent fiber, and the like are preferably used. Hereinafter, in this embodiment, it demonstrates as the base material sheet 4 consisting of a nonwoven fabric.

The base sheet 4 has a plurality of band-like portions 41. The belt-like portion 41 is a portion in which the base material sheet 4 is partially divided by slit portions 42 that penetrate the first surface A and the second surface B, which are both surfaces of the base material sheet 4. The belt-like portions 41 are arranged in parallel via the slit portion 42. Adjacent belt-like portions 41 are separated from each other and have independent deformability (flexibility) within the range in which the slit portion 42 extends. At this time, it is preferable that the adjacent belt-like portions 41 are adjacent to each other at least partially from the viewpoints of thinning and shape maintenance of the absorbent body 10.
Here, the slit portion 42 means a long and narrow cut in the base sheet 4, and does not hinder the absorbability of the absorbent body 10 as long as it can impart independent deformability (flexibility) to the belt-like portion 41. It may have a moderate width in the range. Moreover, that strip | belt-shaped part 41 adjoins means that the adjacent strip | belt-shaped part 41 is touching in the side edge of the longitudinal direction, and does not include the aspect which adjacent strip | belt-shaped parts 41 cross | intersect.

  In addition, the area | region in the base material sheet 4 in which the strip | belt-shaped part 41 is arranged may be called "the arrangement | positioning area | region 45 of the strip | belt-shaped part 41." Moreover, since the arrangement | positioning area | region 45 of the strip | belt-shaped part 41 has the liquid absorptive composite material 3 and the strip | belt-shaped part 41 is a part which has a deformability, it may be called "flexible absorption part 45." The operation of the flexible absorbing portion 45 will be described later.

  The liquid-absorbing composite material 3 is fixed to each belt-like portion 41 via the joining base portion 2. That is, the liquid-absorbing composite material 3 is fixed to the surface of each band-like portion 41 on the first surface A side of the base sheet 4 through the bonding base portion 2. More specifically, the liquid-absorbing composite material 3 is placed and fixed on the linear surface of the fibers 5 constituting the nonwoven fabric forming the base sheet 4 on the surface of each band-like portion 41 via the joining base portion 2. Has been. The plurality of liquid-absorbing composite materials 3 fixed to the fibers 5 are scattered and arranged on the plane of each band-like portion 4. This fixation is due to thermal melting of the heat-meltable resin component included in the bonding base 2. Furthermore, in the present embodiment, the fixing is due to thermal melting of both the heat-meltable resin component included in the bonding base 2 and the resin component of the fiber 5. Therefore, the fixability of the liquid-absorbing composite material 3 in the absorbent body 10 is much higher and stronger than the conventional bonding with an adhesive and carrying by entanglement between fibers. Thereby, the absorber 10 can be thinned into a sheet shape without requiring a conventional pulp fiber or a covering sheet. This point will be described in detail.

  In addition, the liquid absorptive composite material 3 is not limited to the case where it is disposed only on the first surface A side of the base sheet 4 as in the present embodiment, and the first surface A side and the first surface A side are You may distribute | arrange on both surfaces of the 2nd surface B side of the other side. When the absorbent body 10 is incorporated as a liquid absorption holding part of an absorbent article, either the first surface A side or the second surface B side may be arranged facing the wearer's skin surface side. When the liquid absorptive composite material 3 is arranged only on the first surface A side, it is preferable to arrange the first surface A side with the skin surface side facing. Hereinafter, the same applies to other embodiments. Moreover, the absorber 10 may be used in a single layer or in multiple layers.

  Next, the base sheet 4 and the liquid absorbent composite material 3 will be described.

First, the configuration of the base sheet 4 will be described in detail.
In the absorbent body 10 before use (that is, before liquid absorption) of the present embodiment, the base sheet 4 is formed into a sheet shape, and the base sheet 4 has a size that forms the outer shape of the absorbent body 10. The longitudinal direction Y3 and the width direction X3 of the base sheet 4 coincide with the longitudinal direction Y2 and the width direction X2 of the absorber. The longitudinal direction Y3 of the base material sheet 4 and the longitudinal direction Y2 of the belt-like portion 41 coincide with the wearer's front-rear direction when the absorbent article incorporating the absorbent body 10 is worn.
Moreover, in the absorber 10 before use of this embodiment, the strip | belt-shaped part 41 which the base material sheet 4 has is a rectangle thru | or strip shape which has the longitudinal direction Y1 and the width direction X1. The belt-like portion 41 is arranged with the longitudinal direction Y1 facing the longitudinal direction Y2 of the absorbent body 10. Therefore, the slit portion 42 that separates the belt-like portions 41 extends in the longitudinal direction Y <b> 2 of the absorbent body 10. In the flexible absorbent portion 45 in this case, the belt-like portion 41 divided by the slit portion extends in the longitudinal direction Y3 of the base sheet 4, and the plurality of strip-like portions 41 intersect along the width direction X 3 of the base sheet 4. Are arranged in parallel without.
In addition, the longitudinal direction Y1 of the strip-shaped portion 41 is not limited to the above form, and may be arranged toward the width direction X2 of the absorbent body 10, that is, the width direction X3 of the base sheet 4. Further, the longitudinal direction Y1 of the belt-like portion 41 is arranged toward the direction intersecting the width direction X2 and the longitudinal direction Y2 of the absorbent body 10, that is, the direction intersecting the width direction X3 and the longitudinal direction Y3 of the base sheet 4. May be. Considering the prevention of lateral leakage of excretory fluid and high liquid absorption in the absorbent article, the longitudinal direction Y1 of the belt-like portion 41 is directed toward the longitudinal direction Y2 of the absorbent body 10, that is, the longitudinal direction Y3 of the base sheet 4. It is preferable to distribute. The slit portion 42 extends along the longitudinal direction Y <b> 1 of the belt-like portion 41. In the flexible absorbent portion 45 in this case, the belt-like portion 41 divided by the slit portion extends in the width direction X3 of the base sheet 4 and the plurality of strip portions 41 intersect along the longitudinal direction Y3 of the base sheet 4. It is arranged in parallel without doing.

  In the flexible absorption part 45 of the base material sheet 4, the strip | belt-shaped part 41 isolate | separates from each other and has independent deformability (flexibility) as above-mentioned. Due to this deformability, the flexible absorbent portion 45 is provided with extensibility as a whole as compared with the case where the belt-like portion 41 is not provided. More specifically, since the belt-like portion 41 is a portion that is cut and divided by the slit portion 42, the belt-like portion 41 can take a motion of being deformed so as to be separated from each other. Thereby, when the water-absorbing polymer material 1 is liquid-absorbed and swollen, the band-like portions 41 operate so as to widen the mutual distance so as to expand the swelling space of the water-absorbing polymer material 1. As a result, in the absorbent body 10, gel blocking that causes liquid absorption inhibition is difficult to occur, and the absorption performance can be improved.

Regarding the deformability, adjacent ones of the belt-like portions 41 at the time of liquid absorption swelling of the water-absorbing polymer material 1 constituting the liquid-absorbing composite material 3 are the surfaces of the base sheet 4 (first surface A in this embodiment). ), It is more preferable to have deformability at the time of liquid absorption so that they are not on the same plane. This can be set as appropriate for adjustment of the extension length of the slit portion, that is, the length S1 of the strip portion 41 in the longitudinal direction Y1, the fixing amount of the liquid absorbent composite material 3, and the like. Here, the time of liquid absorption swelling means a state after the absorbent body 10 is immersed for 60 minutes in a physiological saline (0.9 mass% sodium chloride aqueous solution) adjusted to 25 ° C.
This point will be described below with reference to FIGS. FIG. 2 schematically shows a part of a cross section in a direction perpendicular to the longitudinal direction Y1 of the belt-like portion 41 of the flexible absorbent portion 45 of the absorbent body 10 before liquid absorption. FIG. 3 schematically shows a state in which the water-absorbing polymer material 1 constituting the liquid-absorbing composite material 3 absorbs the liquid and swells in the cross section shown in FIG. Here, the swollen state refers to a water absorption state corresponding to a state after the absorbent body 10 is immersed in a physiological saline (0.9 mass% sodium chloride aqueous solution) adjusted at 25 ° C. for 60 minutes.

As shown in FIG. 2, before liquid absorption, the flexible absorbent portion 45 of the absorbent body 10 has a plurality of liquid absorbent composite materials that adhere to the surface of the belt-like portion 41 on the first surface A of the base sheet 4. 3. More specifically, the liquid-absorbing composite material 3 is fixed on the linear surface of the fiber 5 located on the surface of each band-like portion 41 via the bonding base portion 2 on the surface. At this time, the adjacent belt-like parts 41 are arranged in parallel on the same plane via the slit part 42.
As shown in FIG. 3, when the absorbent body 10 absorbs the liquid in the flexible absorbent portion 45 in this state, the water-absorbing polymer material 1 constituting the liquid-absorbent composite material 3 swells and increases the volume and mass. As the mass of the water-absorbing polymer material 1 increases, each band-like portion 41 is uniquely deformed so as not to be on the same plane, unlike the position before absorption. Since this deformation occurs in response to the swelling of the water-absorbing polymer material 1, it is not limited to the entire longitudinal direction Y1 of the belt-like portion 41, and may partially occur. Here, the deformation of the belt-shaped portion 41 means that the position of the swollen belt-shaped portion 41 in the thickness direction Z of the base sheet 4 is different from the position before the swelling at least at the site where the water-absorbing polymer material 1 is swollen. Say that. Specifically, it includes a case where the base sheet 4 is shifted vertically in the thickness direction, a case where the base sheet 4 is shifted in the thickness direction Z and an oblique direction, and a case where both are shifted. Thus, in the flexible absorption part 45, the strip | belt-shaped part 41 has a deformability which freely moves up and down according to swelling of the water absorbing polymer material 1 (liquid absorbent composite material 3).
By causing the deformation in the absorbent body 3, the collision between the liquid absorbent composite materials 3 in which the volume of the water absorbent polymer material 1 is increased is reduced in the flexible absorbent portion 45. Thereby, the pressure applied to the swollen liquid-absorbing composite material 3 can be reduced, and the liquid absorption of the water-absorbing polymer material 1 is hardly inhibited. That is, since the water-absorbing polymer material 1 is unlikely to cause absorption inhibition due to gel blocking and can sufficiently exhibit absorption performance, the absorbent body 10 can improve liquid absorbency. The absorber 10 can simultaneously achieve a reduction in thickness and an improvement in absorbability by fixing the liquid-absorbing composite material 3 on the surface of each band-like portion 41 via the bonding base portion 2.

  In the base material sheet 4, it is preferable that the non-slit area | region is distribute | arranged to the both ends before and behind the extending direction (longitudinal direction Y1) of the strip | belt-shaped part 41. FIG. The liquid-absorbing composite material 3 may or may not be fixed to the non-slit region. However, as described later, the non-slit region has a function of suppressing disturbance in the arrangement of the strips, and from the viewpoint of the absorber 10 joining region when used by being incorporated in an absorbent article, It is preferable that the liquid-absorbing composite material 3 is not fixed. Further, the non-slit region may be further on the outer end portion in the width direction X3 of the group of strip-shaped portions 41 arranged in parallel, and the non-slit region extending in the width direction may be other than the end portion.

In the present embodiment, non-slit regions 43 and 43 are disposed at both ends of the base sheet 4 in the longitudinal direction Y3 that coincides with the longitudinal direction Y1 of the belt-like portion 41. That is, the non-slit region 43, the flexible absorbent portion 45, and the non-slit region 43 are arranged along the longitudinal direction Y <b> 3 of the base sheet 4. In the flexible absorption part 45, the several strip | belt-shaped part 41 is paralleled, without crossing about the width direction X3 of the base material sheet 4, as above-mentioned. Note that the two non-slit regions 43 and 43 located before and after the arrangement region 45 of the belt-like portion 41 may have the same length or different lengths in the longitudinal direction Y3. . Further, the non-slit region 43 may be further at an end portion of the base sheet 4 in the width direction X3 (that is, an outer end portion of the band-shaped portion 41 group in the width direction X3) and extends in the width direction. May be other than the end.
Moreover, when the strip | belt-shaped part 41 has orient | assigned the longitudinal direction Y1 to the width direction X3 of the base material sheet 4, a non-slit area | region is distribute | arranged to the both ends of the width direction X3 of the base material sheet 4 (not shown). . That is, the non-slit region 43, the flexible absorbent portion 45, and the non-slit region 43 are arranged along the width direction X <b> 3 of the base sheet 4. At this time, in the flexible absorption part 45, about the longitudinal direction Y3 of the base material sheet 4, the some strip | belt-shaped part 41 is paralleled, without crossing. In this case, the two non-slit regions 43 and 43 may have the same length or different lengths in the width direction X3. Further, the non-slit region 43 may be further at an end portion in the longitudinal direction Y3 of the base sheet 4 (that is, an outer end portion in the width direction X3 of the band-like portion 41 group), and extends in the longitudinal direction. May be other than the end.

  By arranging the non-slit region, the structure in which the plurality of strip portions 41 are arranged in parallel is not easily disturbed, and the shape of the absorber 10 before use is easily maintained. Further, even when the above-described deformability of the belt-like portion 41 is expressed during use (liquid absorption), the non-slit region 43 suppresses deformation at both ends of the belt-like portion 41, and the arrangement of the belt-like portions 41 such as twists is arranged. Disturbance can be suppressed. By these, the absorber 10 suppresses the foreign material feeling at the time of touching the skin before and after use (before and after liquid absorption). In addition, by suppressing the disturbance of the arrangement, a high absorption performance capable of absorbing the liquid without leakage can be expressed.

  In addition, it is preferable that the liquid absorbent composite material 3 described above is not fixed to the non-slit region. Thereby, even when the absorber 3 absorbs the liquid, the shape of the non-slit region that bundles the belt-like portions 41 is maintained, and the structure of the absorber 3 is hardly disturbed.

  Further, when the absorbent body 10 is used by being incorporated in an absorbent article, the non-slit region 43 is preferably a joint region between the absorbent body 10 and other constituent members of the absorbent article. In this case, it is more preferable that the liquid absorbent composite material 3 is not fixed to the non-slit region 43. Thereby, the granular feeling of the liquid absorptive composite material 3 in the strip | belt-shaped part 41 becomes difficult to be transmitted to the surface sheet of an absorbent article. As a result, the softness of the wearer's skin can be felt along with the thinness of the absorbent article. In addition, at the time of liquid absorption, a swelling space of the water-absorbent polymer material 1 constituting the liquid-absorbent composite material 3 is ensured, and the structure of the absorbent body inside the absorbent article is hardly disturbed. By these, the foreign material feeling given to the skin side surface sheet of an absorbent article through before and after liquid absorption is suppressed.

  It is preferable that the flexible absorbent portion 45 be disposed in a range that covers at least the liquid absorption region of the absorbent body 3. When the absorbent body 10 is incorporated into an absorbent article, the flexible absorbent portion 45 is preferably arranged in a range that covers a region corresponding to the excretion portion of the wearer of the absorbent body 10. From the viewpoint of improving the liquid absorbability of the absorbent body 10, the area ratio of the flexible absorbent portion 45 to the entire base sheet 4 when the absorbent body 10 before use is viewed in plan is preferably 50% or more, 50% The above is more preferable. In addition, the area ratio is preferably 95% or less, more preferably 90% or less, from the viewpoint of suppressing the disorder of the structure of the absorber 10. Specifically, the area ratio is preferably 20% to 95%, and more preferably 50% to 90%.

When the base material sheet 4 has a non-slit area | region, length S1 of the longitudinal direction Y1 of the strip | belt-shaped part 41 becomes shorter than the length of the base material sheet 4. FIG. At this time, the base sheet 4 has a size corresponding to the planar shape of the absorbent body 10. Specifically, the length S3 of the base sheet 4 in the longitudinal direction Y3 is preferably 100 mm or more and 1000 mm or less, and the length W3 of the base sheet 4 in the width direction X3 is preferably 50 mm or more and 300 mm or less.
When the longitudinal direction Y1 of the strip-shaped portion 41 is directed to the longitudinal direction Y3 of the base sheet 4 as in the present embodiment, the longitudinal direction Y3 of the base sheet 4 having the length S1 of the longitudinal direction Y1 of the strip-shaped portion 41 The ratio (S1 / S3) to the length S3 is preferably 0.2 or more, and more preferably 0.5 or more, from the viewpoint of increasing the liquid absorbability of the absorbent body 10. Further, the ratio (S1 / S3) is preferably 0.95 or less, and more preferably 0.9 or less, from the viewpoint of suppressing the disorder of the structure of the absorber 10. Specifically, the ratio (S1 / S3) is preferably 0.2 or more and 0.95 or less, and more preferably 0.5 or more and 0.9 or less.
Further, when the longitudinal direction Y1 of the belt-like portion 41 is directed to the width direction X3 of the base sheet 4, the length S1 of the belt-like portion 41 in the longitudinal direction Y1 with respect to the length W3 of the base sheet 4 in the width direction X3. The ratio (S1 / W3) is preferably 0.2 or more and more preferably 0.5 or more from the viewpoint of increasing the liquid absorbability of the absorbent body 10. Further, the ratio (S1 / W3) is preferably 0.95 or less, and more preferably 0.9 or less, from the viewpoint of suppressing the disorder of the structure of the absorber 10. Specifically, the ratio (S1 / W3) is preferably 0.2 or more and 0.95 or less, and more preferably 0.5 or more and 0.9 or less.
Suitably, the length S1 in the longitudinal direction Y1 of the belt-like portion 41 is preferably 20 mm or more, more preferably 30 mm or more, further preferably 50 mm or more, more preferably 950 mm or less, and more preferably 920 mm or less from the same viewpoint. Preferably, it is 900 mm or less. Specifically, the length S1 in the longitudinal direction Y1 of the belt-like portion 41 is preferably 20 mm or more and 950 mm or less, more preferably 30 mm or more and 920 mm or less, and further preferably 50 mm or more and 900 mm or less.

The length W1 in the width direction X1 of the belt-like portion 41 is preferably in the range shown below.
That is, when the longitudinal direction Y1 of the belt-like portion 41 is directed to the longitudinal direction Y3 of the base material sheet 4 as in the present embodiment, the width direction of the base material sheet 4 having the length W1 in the width direction X1 of the belt-like portion 41. The ratio of X3 to length W3 (W1 / W3) is preferably 0.001 or more, more preferably 0.002 or more, preferably 0.2 or less, and more preferably 0.04 or less. Specifically, 0.001 or more and 0.2 or less are preferable, and 0.002 or more and 0.04 or less are more preferable. Thereby, the load of the liquid absorptive composite material 3 can be suitably increased while suppressing gel blocking, and the flexibility and breathability of the absorbent body 10 can be maintained, and the sheet shape can be suitably maintained. .
Moreover, when the longitudinal direction Y1 of the strip-shaped portion 41 is directed to the width direction X3 of the base sheet 4, the length W1 of the strip-shaped portion 41 in the width direction X1 with respect to the length S3 of the longitudinal direction Y3 of the base sheet 4 The ratio (W1 / S3) is preferably 0.0003 or more, more preferably 0.0006 or more, and preferably 0.1 or less, more preferably 0.02 or less. Specifically, 0.0003 or more and 0.1 or less is preferable, and 0.0006 or more and 0.02 or less is more preferable. Thereby, there can exist an effect | action similar to this embodiment.
Suitably, from the same viewpoint, the length W1 in the width direction X1 of the belt-like portion 41 is preferably 0.3 mm or more, more preferably 0.6 mm or more, and preferably 10 mm or less, and 2 mm or less. More preferred is 1.8 mm or less. Specifically, the length W1 of the strip portion 41 in the width direction X1 is preferably 0.3 mm to 10 mm, more preferably 0.6 mm to 2 mm, and still more preferably 0.6 mm to 1.8 mm.

  From the viewpoint of suitably expressing the deformability described above and improving the absorbability of the strip portion 41, the length W1 in the width direction X1 of the strip portion 41 is the average particle size of the liquid absorbent composite material 3 before use (before swelling). It is preferable that it is larger than the diameter. Moreover, it is preferable that the width | variety of the width direction X1 of the strip | belt-shaped part 41 is smaller than the average particle diameter of the liquid absorptive composite material 3 after swelling.

When the longitudinal direction Y1 of the belt-like portion 41 is directed to the longitudinal direction Y3 of the base material sheet 4, the number of the belt-like portions 41 in the single base material sheet 4 is preferably 3 or more, and more preferably 10 or more. 50 or more, more preferably 1000 or less, more preferably 800 or less, and even more preferably 500 or less. Specifically, the number of the belt-like portions 41 in the single base sheet 4 is preferably 3 or more, 1000 or less, more preferably 10 or more and 800 or less, and even more preferably 50 or more and 500 or less.
Moreover, when the longitudinal direction Y1 of the strip-shaped portion 41 is oriented in the width direction X3 of the base sheet 4, the number of the strip-shaped portions 41 in the single base sheet 4 is preferably three or more, and more than ten. More preferably, 50 or more are more preferable, 3500 or less are preferable, 3000 or less are more preferable, and 2000 or less are more preferable. Specifically, the number of the belt-like portions 41 in the single base sheet 4 is preferably 3 or more and 3500 or less, more preferably 10 or more and 3000 or less, and further preferably 50 or more and 2000 or less.
Note that the number of the belt-like portions 41 is the number when the belt-like portions 41 intersecting the virtual line are maximized by arbitrarily drawing a virtual line in a direction orthogonal to the longitudinal direction Y1 of the belt-like portion 41.

  In the absorbent body 10, the base sheet 4 can use various nonwoven fabrics used for absorbent articles without any particular limitation. For example, the nonwoven fabric called an air through nonwoven fabric, a point bond nonwoven fabric, a spun bond nonwoven fabric, a spunlace nonwoven fabric, a three-dimensional shaping nonwoven fabric, etc. are mentioned.

  Moreover, the fiber material which can be used for the nonwoven fabric which makes a base material sheet is not restrict | limited in particular. In particular, from the viewpoint of adhesion to the bonding base 2 of the liquid-absorbing composite material 3, it is preferable to use fibers having components on the surface that are highly compatible with the bonding base 2. More preferably, the fiber materials used for the bonding substrate 2 and the substrate sheet 4 are the same resin. For example, the following fiber etc. are mentioned. That is, polyolefin fibers such as polyethylene (PE) fibers and polypropylene (PP) fibers; fibers using a thermoplastic resin such as polyethylene terephthalate (PET) and polyamide alone; composite fibers having a structure such as a core-sheath type and a side-by-side type For example, fibers having a core-sheath structure in which the sheath component is polyethylene or low-melting-point polypropylene are preferable. Typical examples of the core / sheath fiber include PET (core) and PE (sheath), PP (core) and PE (sheath), and PP (core) and low melting point PP (sheath). Fiber. More specifically, the constituent fibers preferably include polyolefin fibers such as polyethylene fibers and polypropylene fibers, polyethylene composite fibers, and polypropylene composite fibers. Here, the composite composition of the polyethylene composite fiber is polyethylene terephthalate and polyethylene, and the composite composition of the polypropylene composite fiber is preferably polyethylene terephthalate and low-melting polypropylene, and more specifically, PET (core). And PE (sheath), PET (core), and low melting point PP (sheath). These fibers may be used alone to form a nonwoven fabric, but may be used in combination of two or more.

  Next, the liquid absorbent composite material 3 will be described in detail.

  As described above, the liquid-absorbing composite material 3 has the joining base portion 2 containing a heat-meltable resin component on the surface of the water-absorbing polymer material 1. One joining base 2 may be arranged in one liquid absorptive composite material 3 as long as it covers not the whole water-absorbing polymer material 1 but a part, and may be arranged in multiple numbers.

  The liquid-absorbing composite material 3 is not simply supported by entanglement of fibers as in the prior art, but is fixed on the surface of the belt-like portion 41 of the base sheet 4 via the heat-meltable bonding base 2. Therefore, the fixing property in the absorber is high. Furthermore, since the resin component of the bonding base portion 2 of the liquid-absorbing composite material 3 and the fibers 5 are bonded in a melted and integrated state, it is more than simply bonded via an adhesive or the like. High bonding strength. Thereby, the movement of the liquid absorptive composite material 3 before liquid absorption is suppressed, and the foreign object feeling when touching the skin is suppressed. Therefore, the absorbent core 10 does not require a core wrap sheet for preventing the liquid absorbent composite material 3 from falling off. Moreover, since the fixability of the liquid absorbent composite material 3 is high, it is difficult for the absorber 10 to be deformed or broken due to the liquid absorbent composite material 3 dropping off before and after liquid absorption.

  Due to the strong melt adhesion between the liquid absorbent composite 3 and the surface of the belt-like portion 41 of the base sheet 4, the absorbent body 10 does not require a pulp fiber aggregate (fiber web) forming a conventional liquid holding portion. The absorbent body 10 does not contain pulp fibers, is made into a sheet shape consisting only of the base sheet 4 and the liquid-absorbing composite material 3, and is further reduced in thickness as compared with those containing a conventional pulp fiber assembly. By making the absorber thinner, the softness of the absorbent article is improved, and the foreign object feeling during use is suppressed. This can improve the feeling of wearing in the absorbent article incorporating the absorbent body 10 in combination with the above-described suppression of the shape loss and breakage of the absorbent body.

  In addition, in the absorbent body 10, the liquid-absorbing composite material 3 is exposed and fixed on the surface of the base material sheet 4 by the above-described strong fusion and fixation. Therefore, the water-absorbing polymer material 1 constituting the liquid-absorbing composite material 3 is compared with a conventional water-absorbing polymer material sandwiched and fixed between fiber sheets or a water-absorbing polymer material confined in a bag-like portion. Thus, a large space allowing liquid swelling can be obtained. Thereby, coupled with the deformability of the belt-like portion 41 described above, gel blocking that causes liquid absorption inhibition can be suppressed at a higher level.

  Further, due to the strong fixability of the liquid-absorbing composite material 3 by the above-described strong melt fixation, the density of the liquid-absorbing composite material 3 can be accurately controlled on the surface of the base sheet, and the liquid absorbability It is possible to control the preferable dispersive arrangement of the composite material 3.

  In the liquid-absorbing composite material 3, it is preferable that the water-absorbing polymer material 1 and the bonding base 2 are directly bonded. Direct bonding refers to bonding without an adhesive or the like. Examples of the direct bonding include bonding due to adhesiveness of the water-absorbing polymer material 1 when it contains water, bonding due to melting of the resin component of the bonding base 2, and the like. That is, it is preferable that the bonding is performed with the minimum necessary bonding area by utilizing the adhesiveness of the water-absorbing polymer material 1 and the bonding base 2 itself. Thereby, the liquid absorptivity of the surface of the water-absorbing polymer material 1 other than the part covered by the bonding base 2 can be sufficiently secured without being hindered by the adhesive or the like. In the liquid absorbent composite material 3, a part of the bonding base 2 is embedded in the water absorbent polymer material 1, and a part of the bonding base 2 protrudes from the surface of the water absorbent polymer material 1. It is in a state. As a result, the joining base 2 is less likely to drop off when it is swelled from the water-absorbing polymer material 1, and can be melted and fixed to the surface of the base sheet 4, thereby improving the fixability.

  The bonding base 2 can be selected from either hydrophilic or hydrophobic. It is preferable that the bonding base 2 is hydrophilic from the viewpoint of increasing the drawability of the liquid into the water-absorbing polymer material. The resin component itself constituting the bonding base 2 may be hydrophilic, or a hydrophilic activator may be added. On the other hand, even when the bonding base portion 2 is hydrophobic, it can be controlled so as not to inhibit liquid absorption by controlling the coverage.

The resin component constituting the bonding base portion 2 has a heat melting property for melting and fixing with the surface of the belt-like portion 41 (the fiber 5 in the present embodiment) of the base sheet 4.
Various resin components can be used without particular limitation. Specifically, polyolefins such as polyethylene, high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene, crystalline propylene copolymer composed of propylene and α-olefin; polyamides; polyethylene terephthalate, poly Examples include polyesters such as butylene terephthalate, diol and terephthalic acid / isophthalic acid copolymerized low-melting point polyester, polyester elastomer, and the like; and fluororesins.

  The shape of the bonding base 2 is not particularly limited as long as it can be bonded to the surface of the water-absorbing polymer material 1, and various shapes can be adopted. For example, fibrous form and granular form (powder) are mentioned. From the viewpoint of uniformly attaching the bonding base 2 to the surface of the water-absorbing polymer material 1 and improving the fixability, it is preferably granular (powder). When it is granular (powder), a spherical shape is more preferable from the viewpoint of adhesion to the fiber 5.

  The size of the bonding base 2 is a size that covers a part of the surface of the water-absorbing polymer material 1 and is smaller than the water-absorbing polymer material 1. When the bonding base 2 is made of a granular (powder) resin component, the smaller the average particle size, the better the packing property. However, when the surface is within the following range, the surface of the water-absorbing polymer material 1 is covered with the bonding substrate 2. It is preferable that a gap is formed in the water-absorbing polymer material 1 and the water-absorbing polymer material 1 can exhibit water absorption. In this respect, 10 μm or more is preferable, 15 μm or more is more preferable, and 20 μm or more is even more preferable. If the average particle diameter is in the following range, it is preferable that the joining base material 2 is less likely to fall off the water-absorbing polymer material 1 by an external force after the joining base material 2 is joined to the water-absorbing polymer material 1. In this respect, 100 μm or less is preferable, 80 μm or less is more preferable, and 65 μm or less is even more preferable. Specifically, the average particle diameter is preferably 10 μm to 100 μm, more preferably 15 μm to 80 μm, and still more preferably 20 μm to 65 μm. In addition, the average particle diameter of the resin component of the joining base 2 is a particle diameter measured by the (average particle diameter measuring method) described later.

The water-absorbing polymer material 1 becomes a gel by absorbing water and can retain water. It is a polymer material that has been surface-crosslinked because of its ability to retain absorbed water. What can absorb and hold | maintain the liquid 20 times or more of own weight and can be gelatinized is preferable.
As the water-absorbing polymer material 1, various materials used for the absorber can be employed without particular limitation. For example, a hydrogel material obtained by polymerizing a water-soluble ethylenically unsaturated monomer containing acrylic acid or acrylate as a main component and optionally adding a crosslinking agent may be mentioned. In addition, polyethylene oxide, polyvinylpyrrolidone, sulfonated polystyrene and polyvinylpyridine cross-linked product, saponified product of starch-poly (meth) acrylonitrile graft copolymer, starch-poly (meth) acrylic acid graft copolymer, starch-poly ( Examples thereof include hydrolysates of (meth) acrylic ester graft copolymers. These water-absorbing polymer materials can be used alone or in combination of two or more.

  As the shape of the water-absorbing polymer material 1, various materials used for the absorber can be used without particular limitation. For example, a spherical shape, a granular shape, a fibrous shape, a bowl shape, a lump shape, and the like can be given.

  The size of the water-absorbing polymer material 1 contributes to the liquid absorbability of the absorbent body 10, and the sticking to the surface of each belt-like portion 41 of the base sheet 4 is both in the state before water absorption and in the swollen state after water absorption. It is preferable to set within the range to be held. Specifically, when the water-absorbing polymer material 1 is granular, the average particle diameter of the water-absorbing polymer material 1 is preferably 200 μm or more in the state before swelling from the viewpoint of the liquid absorbability of the absorbent body 10. 250 μm or more is more preferable, and 300 μm or more is even more preferable. The average particle diameter is preferably 1000 μm or less, more preferably 650 μm or less, and even more preferably 500 μm or less, from the viewpoint of adhesion to the surface of each band-like portion 41. Specifically, the average particle size is preferably 200 μm or more and 1000 μm or less, more preferably 250 μm or more and 650 μm or less, and further preferably 300 μm or more and 500 μm or less. The “state before swelling” of the water-absorbing polymer material 1 means a state after reaching an equilibrium state at a room temperature of 22 ° C. and a humidity of 50%. The average particle diameter of the water-absorbing polymer material 1 is a particle diameter that is measured by the method described below (Method for measuring average particle diameter).

  When the water-absorbing polymer material 1 and the bonding base portion 2 are granular, the average particle size of the bonding base portion 2 is preferably smaller than the average particle size of the water-absorbing polymer material 1. The ratio of the average particle diameter of the water-absorbing polymer material 1 and the bonding base 2 in the liquid absorbent composite material 3 is preferably 5: 1 to 100: 1, more preferably 8: 1 to 70: 1. More preferably, it is 10: 1 to 50: 1. Thereby, a gap is generated when the surface of the water-absorbing polymer material 1 is covered with the bonding substrate 2, and the water-absorbing polymer material 1 can exhibit water absorption.

(Measuring method of average particle size)
The average particle diameter of the water-absorbing polymer material 1 and the bonding base portion 2 is a value measured by the following method.
First, when analyzing from a commercially available product etc., the adhesive is dissolved using an organic solvent, and the nonwoven fabric to which the absorbent polymer is fixed is taken out. Next, using a scanning electron microscope JCM-5100 (trade name) manufactured by JEOL Ltd., the liquid-absorbing composite material 3 fixed to the base material sheet 4 is photographed (the water-absorbing polymer material 1 or the joint to be measured). Adjustment to a magnification that the base 2 can measure, 20 sample measurements). The major axis diameter of the photographed image is defined as the particle diameter, and the average value of 20 samples is defined as the average particle diameter. In addition, how to distinguish the water-absorbing polymer material 1 and the joining base part 2 can be discriminate | determined by whether shape deformation | transformation is caused by water absorption.

In the liquid-absorbing composite material 3, the degree of coverage of the bonding base 2 on the surface of the water-absorbing polymer material 1 is determined by the adherence (stability) to the surface of each band-shaped portion 41 and the water absorption of the water-absorbing polymer material 1 Can be set by relationship. From the viewpoint of adherence to the surface of each band-like portion 41 of the base sheet 4, the higher the degree of coverage of the bonding base portion 2 on the surface of the water-absorbent polymer material 1, the better. On the other hand, from the viewpoint of water absorption of the water-absorbing polymer material 1, the lower the degree of coating of the bonding base 2 on the surface of the water-absorbing polymer material 1, the better. The degree of the coating can be set in consideration of a balance between both performances.
The degree of coating of the bonding base portion 2 on the surface of the water-absorbing polymer material 1 can be shown, for example, as a mass ratio between the water-absorbing polymer material 1 and the bonding base portion 2 in the liquid absorbent composite material 3. The mass of the bonding base 2 is the mass of the entire resin component existing as the bonding base 2 in one liquid-absorbing composite material 3. Therefore, when there are a plurality of bonding bases 2 in one liquid-absorbing composite material 3, the total mass of the resin components of the plurality of bonding bases 2. The mass ratio of the water-absorbing polymer material 1 and the bonding base 2 in the liquid-absorbing composite material 3 is preferably 30: 1 to 2: 1, more preferably 15: 1 to 3: 1, and 10: More preferably, it is 1-4: 1.

The degree of coverage of the bonding base 2 on the surface of the water-absorbing polymer material 1 can also be shown as the coverage (area ratio) of the bonding base 2 obtained by the following SEM observation. The coverage is preferably 6% or more and 80% or less, more preferably 8% or more and 60% or less, and still more preferably 10% or more and 40% or less.
(Measurement method of coverage)
The coverage of the bonding base 2 in the liquid absorbent composite material 3 can be measured by the following method.
Using a scanning electron microscope JCM-5100 (trade name) manufactured by JEOL Ltd., the liquid absorbent composite material 3 is allowed to stand, and an image (liquid to be measured) taken from a direction perpendicular to the surface to be measured of the sample (Adjustment to a magnification at which the absorbent composite material 3 can be measured) is printed, and the area of the entire liquid absorbent composite material 3 and the area of each joint base 2 are traced on a transparent PET sheet. The image is binarized. Using the binarized image, the area of the liquid absorbent composite material 3 and the area of the bonding base 2 are obtained. Coverage (%) = total area of joint base 2 / area of liquid absorbent composite 3 × 100. The measurement is performed at 10 locations, and the average is the coverage.

In the present embodiment, for the base sheet 4 made of non-woven fabric, the fibers 5 of the band-shaped portion 41 to which the liquid-absorbing composite material 3 is fixed are raised fibers 51 (hereinafter referred to as “band”) in the band-shaped portion 41 as shown in FIG. More preferably, it is also called raised fiber 51.). The raised fiber 51 refers to a portion where the fiber protrudes from the surface of the fiber assembly portion 52 constituting the main body of the belt-like portion 41. The raised fiber 51 may be a portion where one end of the fiber protrudes as a free end without being joined to another fiber, or may be a portion protruded like a loop. From this, it can be said that the raised fiber 51 is a fiber in a region having a greater inter-fiber distance than the fiber assembly portion 52. Since the raised fibers 51 protrude from the plane of the belt-like portion 41 of the base sheet 4, they are entangled well with the liquid absorbent composite material 3, and the joining base portion 2 on the liquid absorbent composite material 3 and the fibers are easily in contact with each other. Therefore, the adhesiveness of the liquid absorbent composite material 3 is improved. In addition, raising can be performed by various commonly used methods such as buffing treatment (raising treatment).
Moreover, since the raising fiber 51 has a larger movable range than the fiber of the fiber assembly part 52, the space | interval of raising fiber 51 tends to spread at the time of the water swelling of the liquid absorptive composite material 3. Therefore, it is preferable that the liquid-absorbing composite material 3 is fixed to the raised fibers 51 because the room for the liquid-absorbing composite material 3 to swell is larger than that of the fiber assembly portion 4A. Moreover, the space | interval of adjacent liquid absorptive composite materials 3 also spreads, it becomes difficult to produce the gel blocking at the time of swelling and the absorption inhibition by it, and is preferable. In addition, softness when touching the skin is improved.

  In the present embodiment, the thickness of the absorbent body 10 before liquid absorption is preferably 3.0 mm or less, more preferably 2.5 mm or less, and still more preferably 2.0 mm or less, from the viewpoint of improving the wearing feeling due to the thinning. The thickness of the absorbent body 10 before liquid absorption is preferably 0.5 mm or more, more preferably 0.8 mm or more, and still more preferably 1.0 mm or more, from the viewpoint of securing the amount of water-absorbing polymer and fixing properties. . The thickness of the absorber can be confirmed by a measurement method described later.

  In the absorbent body 10, from the viewpoint of preventing gel blocking and realizing excellent absorption performance, the change in thickness before and after absorption of the liquid is preferably 2 times or more, more preferably 2.5 times or more, More preferably, it is 3 times or more. Further, the change in thickness before and after absorption of the liquid is preferably 18 times or less, more preferably 10 times or less, and more preferably 8 times or less from the viewpoint of improving the wearing feeling after liquid absorption. More preferably, it is particularly preferably 6 times or less.

  Further, in the absorbent body 10, the thickness after liquid absorption is preferably 30 mm or less, more preferably 25 mm or less, and still more preferably 20 mm or less, from the viewpoint of improving the wearing feeling due to thinning. The thickness after liquid absorption is preferably 1.0 mm or more, more preferably 1.6 mm or more, and still more preferably 2.0 mm or more from the viewpoint of preventing gel blocking and realizing excellent absorption performance.

(Measurement method of absorber thickness)
The thickness of the absorber before liquid absorption and after liquid absorption can be measured by the following method.
(1) Measurement before liquid absorption (before liquid absorption) From the product to be evaluated, weaken the adhesive strength of the hot melt adhesive using a cold spray, carefully remove each member and take out the absorber, Cut in the direction. The cut surface of the absorber is enlarged to a size that allows the measurement area of the digital microscope VHX-1000 manufactured by Keyence Corporation to enter the field of view sufficiently, and a weight is placed on the absorber so that a pressure of 0.05 kPa is applied. And measure the thickness. The measurement is performed 10 times, and the average value is taken as the thickness of the absorber before liquid absorption.
(2) Measurement after liquid absorption (after liquid absorption) It is invalidated by means such as cutting off all gathers contained in the product to be evaluated and made flat. Soak in a sufficient amount of artificial urine (the liquid will not run out) from the surface material side to the liquid surface for 30 minutes. Leave the surface material on the wire net for 30 minutes, and remove the liquid that could not be absorbed. Each member is carefully peeled from the product, the absorbent body is taken out, and the absorbent body is cut in the width direction. The cut surface of the absorber is enlarged to a size that allows the measurement area of the digital microscope VHX-1000 manufactured by Keyence Corporation to enter the field of view sufficiently, and a weight is placed on the absorber so that a pressure of 0.05 kPa is applied. And measure the thickness. The measurement is performed 10 times, and the average value is taken as the thickness of the absorber after liquid absorption.

Thus, the absorber of the present invention has high fixability to the base material sheet 4 (band-like portion 41) of the water-absorbing polymer material 1 or the liquid-absorbent composite 3, and is prevented from falling off. For this reason, the absorbent body of the present invention is further reduced in thickness from the conventional one, and the drop-off and movement of the water-absorbing polymer material 1 or the liquid-absorbent composite 3 before liquid absorption is suppressed, and the foreign object feeling when touching the skin. Is suppressed. That is, the improvement of the softness of the absorbent article due to the thinning of the absorbent body is suppressed, and the feeling of foreign matter is suppressed, so that the wearing feeling is improved. Further, after absorption, the absorber is prevented from being deformed due to dropping off of the water-absorbing polymer material 1 or the liquid-absorbing composite 3, and this also improves the feeling of wearing.
In addition, since the liquid absorbent composite 3 is exposed and fixed on the surface of the belt-like portion 41, the absorbent body of the present invention has a large space allowing liquid swelling and causes liquid absorption inhibition. Gel blocking is unlikely to occur. In addition, due to the deformability of the belt-like portion 41, a space allowing liquid swelling during liquid absorption is expanded, gel blocking is further suppressed, and liquid absorption performance is improved.

  Next, the preferable manufacturing method of the absorber of this invention is demonstrated as a case where a base material sheet consists of a nonwoven fabric. In addition, the following (formation process of a liquid absorptive composite material) and (formation process of a strip | belt-shaped part) are separate process processes, may not necessarily be performed in this order, and may be performed in parallel simultaneously. , May be performed in the reverse order.

(Formation process of liquid-absorbing composite material)
Add water to the water-absorbing polymer material prepared in advance and knead. Next, a resin component having heat-fusibility is added and kneaded. Due to the addition of water, the surface of the water-absorbing polymer material is made sticky, thereby making it easy to form a bonding base made of a heat-meltable resin component. Therefore, it is sufficient that the hydration is an extent that causes stickiness. Specifically, it is preferable to add water about 10 times by mass ratio with respect to the water-absorbing polymer material. As the water-absorbing polymer material, those usually used for absorbent articles and the like can be used without particular limitation.
Next, the water-absorbing polymer material to which water is added and the resin component is added is subjected to treatments such as drying, pulverization, and classification to obtain a liquid-absorbing composite material used in the absorbent body of the present invention.
For the kneading, drying, pulverization, and classification, a commonly used apparatus can be used without particular limitation.

(Strip formation process)
In order to form the slit part which divides a strip | belt-shaped part with respect to the raw material nonwoven fabric used as a base material sheet, the various cut processing normally used can be employ | adopted without a restriction | limiting in particular. For example, the raw material nonwoven fabric can be transported and cut between a rotary die having a plurality of cutter blades on the peripheral surface and a receiving roll having a flat peripheral surface disposed opposite to the rotary die. Depending on the direction of the cutter blade, the direction in the longitudinal direction of the belt-shaped portion in the base sheet can be determined. Depending on the length of the cutter blade, the length S1 of the strip portion 41 in the longitudinal direction Y1 can be set as appropriate, and the length W1 of the strip portion 41 in the width direction X1 can be set as appropriate depending on the interval between the cutter blades. .
In addition, when the liquid absorbent composite material 3 is fixed to the raised fiber of the nonwoven fabric forming the base sheet, the surface of the raw material nonwoven fabric to which the liquid absorbent composite material 3 is fixed before and after the formation of the band-shaped portion, Various commonly used processes such as buffing are performed.

(Fixing process of liquid absorbent composite material)
The liquid absorbent composite material 3 is sprayed on the raw material nonwoven fabric on which the slit portions are formed. Thereafter, for the purpose of facilitating the contact between the surface of each strip portion of the base sheet and the liquid absorbent composite material, it is preferable to pressurize the liquid absorbent composite material from above, if necessary. It is preferable that the pressurization at this point is a pressurization such that a 5 kg roller is reciprocated once. In addition, since the raw material nonwoven fabric is usually used after being unwound from a long and roll shape, it is preferable to carry out a hot air recovery treatment as necessary before spraying the liquid-absorbing composite material. Moreover, it is preferable to fluff if necessary before spraying.
Next, heat treatment is performed on the base sheet on which the liquid-absorbing composite material is dispersed, and the joining base portion and the fibers of the base sheet are melted and integrated. For the heat treatment here, a method usually used for a nonwoven fabric can be employed without any particular limitation. The heating temperature is preferably 3 ° C. to 50 ° C., more preferably 5 ° C. to 30 ° C. higher than the higher melting point of the melting point of the fibers of the base sheet or the melting point of the bonding base. In addition, when a base material sheet | seat consists of a component which does not heat-melt, it is preferable to set it as the heating temperature of the said range with respect to melting | fusing point of a joining base part. When the heat treatment is hot air treatment, the wind speed of the hot air is set to 1 m / s or more and 10 m / s or less, preferably 1.5 m / s or more and 8 m / s or less. By setting the air velocity of the hot air to be equal to or higher than the above lower limit, heat can be transferred to the fiber and the bonding base of the base sheet, and can be surely melted and fixed, thereby securing the fixing property. On the other hand, by setting it as the above upper limit or less, heat is not applied to the fibers, and the texture of the base sheet is improved.

  The absorber of the present invention can be applied to various fields. For example, it is suitably used as a liquid holding part for absorbent articles used to absorb liquid discharged from the body such as sanitary napkins, panty liners, disposable diapers, and incontinence pads.

  The absorbent article including the absorbent body of the present invention is typically configured by sandwiching the absorbent body between a skin-side topsheet and a non-skin-side backsheet. As a constituent member of the absorbent article, a material usually used in the technical field can be used without particular limitation. For example, as the surface sheet, a liquid-permeable soft touch can be used, and examples thereof include various nonwoven fabrics such as an air-through nonwoven fabric. Moreover, a surface sheet may consist of a some nonwoven fabric, and may consist of a combination of a nonwoven fabric and another raw material. As the back sheet, a liquid-impermeable or water-repellent sheet such as a thermoplastic resin film or a laminate of the film and a nonwoven fabric can be used. The back sheet may have water vapor permeability. The absorbent article may further include various members according to specific uses of the absorbent article. For example, when applying an absorbent article to a disposable diaper or a sanitary napkin, a pair or two or more pairs of three-dimensional guards can be disposed on the left and right sides of the topsheet.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, this invention is limited to this and is not interpreted. In the examples, “part” and “%” are based on mass unless otherwise specified.

Example 1
(1) Preparation of liquid-absorbing composite material A liquid-absorbing composite material was prepared based on the above-described (Method for producing liquid-absorbing composite material). Specifically, 300 g of ion-exchanged water was added to 30 g of the water-absorbing polymer material taken from the absorber of the product name “Merry's Pants Sarasara Air Through L Size” (made in 2016) manufactured by Kao Corporation, and mixed for 5 minutes with a kneader. And evenly swollen. Next, 5.0 g of polyethylene powder “XM-220” (trade name, manufactured by Mitsui Chemicals, Inc.), which is a heat-meltable resin component serving as a bonding base, was added to the kneader and further mixed for 10 minutes. Then, it dried for 8 hours at 105 degreeC using the electric dryer. Subsequently, it grind | pulverizes using a grinder (Osaka Chemical make, one dark rusher WC-3L), performs classification using an electromagnetic sieve, and removes a particle size smaller than 106 micrometers and a particle diameter larger than 850 micrometers, Example 1 A liquid-absorbing composite material was obtained. As a result of measuring based on the above-mentioned (Measurement method of coverage), the coverage of the bonding base in this liquid absorbent composite material was 24%.
(2) Production of Absorber Buffing treatment (raising treatment) was performed on one surface of a long sheet-shaped raw material nonwoven fabric (basis weight 25 g / m ² ) to be a base sheet to form napped fibers. In this raw material nonwoven fabric, a 2.4-dtex × 51 mm core-sheath type composite fiber having a core made of polyethylene terephthalate (melting point 258 ° C.) and a sheath made of polyethylene (melting point 135 ° C.) was used.
Subsequently, a slit part was formed and cut with respect to the raw material nonwoven fabric subjected to the raising treatment, and a base sheet having a size of 135 mm × 280 mm provided with a strip-like part and a non-slit part was produced. In the produced base material sheet, it was set as the structure by which the longitudinal direction Y1 of the strip | belt-shaped part was turned to the longitudinal direction Y3 of a base sheet, and the non-slit part was arrange | positioned at the front-back end of the longitudinal direction of this strip | belt-shaped part. The length S1 in the longitudinal direction Y1 and the length W1 in the width direction X1 of the belt-like portion were 224 mm and 1.5 mm, respectively, and 90 belt-like portions were arranged in the produced base sheet.
5.8g of the above-mentioned liquid-absorbing composite material was sprayed on the belt-like portion of the base sheet, and a 5 kg roller was reciprocated once and pressed so as not to scatter. Next, a hot air treatment of blowing hot air at 140 ° C. for 3 minutes at a wind speed of 1.4 m / s was performed, and a treatment for melting and integrating the bonding base portion of the liquid absorbent composite material and the surface components of the constituent fibers of the base sheet was performed. . That is, the liquid absorptive composite material was fixed to the fibers of the base sheet through the bonding base.
The absorber sample of Example 1 was produced through the above processing.
When this absorber sample S1 was confirmed using the electron microscope, the liquid absorptive composite material was joined to the surface of the raising fiber of a base material sheet. Moreover, in the liquid absorptive composite material 3, a plurality of joining bases made of polyethylene powder, which is a heat-meltable resin component, were formed on the surface of the water-absorbing polymer material. It was confirmed that the liquid-absorbing composite material was fixed to the raised fibers of the base sheet via the bonding base. The same applies to Examples 2 to 5 below.
(3) Preparation of diapers Absorber is removed from Kao Co., Ltd. product name “Merry's Pants Sarasara Air-Through L Size” (2016). Instead, an absorbent sample is introduced, and a baby diaper for evaluation is introduced. Produced.

(Example 2)
An absorber sample of Example 2 was produced in the same manner as in Example 1 except that the amount of polyethylene powder serving as a bonding base was 1.0 g and the coverage was 8%. Separately, a baby diaper for evaluation in Example 2 was produced in the same manner as in Example 1 by using an absorbent sample.

(Example 3)
An absorber sample of Example 3 was produced in the same manner as in Example 1 except that the amount of polyethylene powder serving as the bonding base was 15.0 g and the coverage was 73%. Separately, a baby diaper for evaluation of Example 3 was produced in the same manner as in Example 1 by using an absorber sample.

Example 4
An absorber sample of Example 4 was produced in the same manner as in Example 1 except that the raising treatment was not performed on the base sheet. Separately, a baby diaper for evaluation of Example 4 was produced in the same manner as in Example 1 by using an absorber sample.

(Comparative Example 1)
An absorber sample of Comparative Example 1 was produced in the same manner as in Example 1 except that the base sheet did not have a belt-like part. Separately, a baby diaper for evaluation of Comparative Example 1 was prepared in the same manner as Example 1 by using an absorbent sample.

(Comparative Example 2)
An absorbent body sample of Comparative Example 2 was produced in the same manner as in Example 4 except that the base sheet did not have a belt-like portion. Separately, a baby diaper for evaluation of Comparative Example 2 was obtained in the same manner as in Example 1 by using an absorber sample.

(Comparative Example 3)
The liquid holding portion of the absorber, a mixed stacks of basis weight 150 g / m ² pulp fiber and basis weight 250 g / m ² of the water-absorbing polymer material (the same as in Example 1), the uneven surface is two-sided The absorbent body sample of Comparative Example 3 was prepared by coating the outer surface with a tissue paper. Separately, a baby diaper for evaluation of Comparative Example 3 was produced in the same manner as in Example 1 by using an absorbent sample.

(Comparative Example 4)
An absorber sample of Comparative Example 4 was produced in the same manner as Comparative Example 3, except that the basis weight of the pulp fiber was 75 g / m ² . Separately, a baby diaper for evaluation of Comparative Example 4 was produced in the same manner as in Example 1 by using an absorber sample.

(test)
1. Measurement of thickness of each absorber sample As described above (Measurement method of absorber thickness), (1) Measurement before absorption of liquid (before absorption) and (2) Measurement after absorption of liquid (after absorption) Based on each measured method, the thickness before and after liquid absorption of each absorber sample of Examples 1-4 and Comparative Examples 1-4 was measured.

2. Fixability Cut the center of the absorbent body in the width direction. The cut surface was faced down and shaken 50 times by hand.
Support rate = (weight of water-absorbing polymer material before shaking (g) −weight of water-absorbing polymer material dropped out (g)) / weight of water-absorbing polymer material before shaking (g) × 100
Calculated with

3. Absorption time (sec)
For the measurement of the absorption time, a pressure of 3.5 kPa was evenly applied on the diaper to be evaluated, a cylinder with a cross-sectional area of 1000 mm ² placed at the approximate center of the test specimen was applied, and artificial urine was injected therefrom. A total of 160 g of artificial urine was injected four times at 40 g every 10 minutes, and the time during which the liquid disappeared from the diaper surface from the cylinder during the fourth injection was measured. Three measurements were taken and the average was taken as the absorption time.
The composition of the artificial urine used in the measurement method is as follows. 1.94% by mass of urea, 0.7954% by mass of sodium chloride, 0.11058% by mass of magnesium sulfate (septahydrate), 0.06208% by mass of calcium chloride (dihydrate), 0.19788% by mass of potassium sulfate , Polyoxyethylene lauryl ether 0.0035 mass% and ion-exchanged water (remaining amount).

  The results of the above tests were as shown in Table 1 below.

As shown in Table 1 above, in the absorbers of Comparative Examples 1 and 2, the liquid-absorbing composite material was fixed to a flat base sheet and the thickness was reduced to less than 1 mm, while the absorption time was 300 seconds. The liquid could not enter even after exceeding. This is because the base material sheet does not have a belt-like portion, so that the swelling space of the liquid-absorbing composite material (water-absorbing polymer material) at the time of liquid absorption cannot be secured, causing gel blocking. I think that the.
Moreover, the absorbers of Comparative Examples 3 and 4 contained pulp fibers, and had a thickness exceeding 1 mm before liquid absorption. The absorption time was 80 seconds and 95 seconds corresponding to the thickness, which was shorter than those of Comparative Examples 1 and 2. In Comparative Example 4, gel blocking was observed and the absorption rate was reduced because the pulp fiber basis weight was lowered and the thickness was made thinner than in Comparative Example 3. Fixability was also worse than Comparative Example 3. Therefore, Comparative Examples 3 and 4 were unable to achieve both reduction in the thickness of the absorber and improvement in liquid absorption.
On the other hand, the absorbers of Examples 1 to 4 were thinned by fixing the liquid-absorbing composite material to a sheet-like base material sheet having a belt-like portion, and the thickness before liquid absorption was less than 1 mm. At the same time, the total 160 g of artificial urine was absorbed four times, and the time was between 34 seconds and 52 seconds, and it took less than 1 minute. This is an excellent absorption time that cannot be achieved by Comparative Examples 1 and 2 with the same thickness, and is about one third of the absorption time of Comparative Examples 3 and 4 including pulp fibers. It was excellent. This is considered to be due to the fact that the band-shaped portion of the base sheet was deformed during the liquid absorption swelling of the water-absorbing polymer material and a swelling space could be secured. That is, it is considered that high absorption rate could be maintained by suppressing gel blocking which causes absorption inhibition. Moreover, in Examples 1-4, when the difference of the thickness before liquid absorption and the thickness after liquid absorption arises moderately, the distance of a water absorbing polymer material is easy to leave | separate (the space which swells can be ensured), and an absorption speed is quick. It was.
As described above, Examples 1 to 4 were able to achieve both reduction in thickness and improvement in liquid absorption.

DESCRIPTION OF SYMBOLS 1 Water-absorbing polymer material 2 Joining base part 3 Liquid-absorbing composite material 4 Base material sheet 41 Band-shaped part 42 Slit part 43 Non-slit area 45 Arrangement | positioning area | region (flexible absorption part) of a band-shaped part
46 Movable Absorber 5 Fiber 10 Absorber

Claims (8)

Having a base sheet with a plurality of strips,
An absorbent body in which a liquid-absorbing composite material having a joining base portion containing a heat-meltable resin component on the surface of a water-absorbing polymer material is fixed to the belt-like portion via the joining base portion.   The absorbent body according to claim 1, which has deformability at the time of liquid absorption so that the adjacent strip portions are not coplanar with each other on the surface of the base sheet during liquid absorption swelling of the water absorbent polymer material.   The absorber according to claim 1 or 2, wherein the bonding base is directly bonded to the surface of the water-absorbing polymer material.   The absorber according to any one of claims 1 to 3, wherein the base sheet is provided with a non-slit region at both ends in the longitudinal direction of the belt-like portion.   The absorbent body according to any one of claims 1 to 4, wherein the base sheet is a nonwoven fabric.   The absorber according to any one of claims 1 to 5, wherein the liquid-absorbing composite material is fixed to a raised fiber included in the belt-shaped portion.   The absorbent body according to claim 4, wherein the non-slit region is a joint region when the absorbent body is incorporated into an absorbent article. The absorbent article which has an absorber of any one of Claims 1-7.

Images