JP2006014884A - Body fluid absorbent structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a body fluid absorbent structure having a perfect body fluid leakage preventing effect in the body fluid absorbent structure applicable to an absorbent article such as a paper diaper, a sanitary napkin, a urine removing pad and an incontinence pad. <P>SOLUTION: An absorbent material 53A having body fluid retentive property is provided under a surface sheet 51. An absorbent material 52 including a fiber assembly composed of rattan and having body fluid permeability is interposed between the surface sheet 51 and the absorbent material 53A having the body fluid retentive property, and the absorbent material 53A having the body fluid retentive property is formed with a pressing part 57 extending in the longitudinal direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a body fluid absorbing structure applicable to absorbent articles such as paper diapers, sanitary napkins, urine pads, and incontinence pads.

  Absorbent articles such as paper diapers, sanitary napkins, urine-absorbing pads, and incontinence pads generally have a body fluid absorption structure in which an absorbent material having body fluid retention is provided under a top sheet. Conventionally, the absorbent having such body fluid retention property is formed of, for example, a material in which an absorbent polymer made into granular powder is mixed in pulp such as cotton-like pulp or synthetic pulp, or fluff-like pulp. It was. However, since the absorbent material made of these materials has a low speed of absorbing body fluid, the body fluid may move to the end of the article before being absorbed by the absorbent, and leakage may occur from the end. was there.

  Therefore, in recent years, a non-woven fabric sheet is interposed between the top sheet and the absorbent having body fluid retention (see, for example, Patent Document 1). This nonwoven fabric sheet has a function of quickly absorbing body fluid and preventing movement of the body fluid to the end of the article.

However, since the nonwoven fabric sheet has a small body fluid absorption capacity, the following problems remain in the body fluid absorption structure in which the nonwoven fabric sheet is interposed.
That is, the non-woven sheet allows the absorbed body fluid to pass through as it is and is absorbed by the absorbent having body fluid retention, and the absorbent having body fluid retention is slow in absorbing body fluid, as described above. The body fluid permeability of the nonwoven fabric sheet is so-called that the inlet is wide but the outlet is narrow. Therefore, a nonwoven fabric sheet with a low capacity to absorb bodily fluids, when absorbing a large amount of bodily fluids, such as when bodily fluids must be absorbed repeatedly, will fall into an overflow state and completely block the movement of bodily fluids to the end of the article There was a risk that leakage could occur.
JP 2001-524399 A

  The main problem to be solved by the present invention is to provide a body fluid absorbing structure capable of perfecting the body fluid leakage preventing effect.

The present invention that has solved this problem is as follows.
[Invention of Claim 1]
A body fluid absorption structure provided with an absorbent material having body fluid retention under the top sheet,
Between the surface sheet and the absorbent having a body fluid retention property, an absorbent having a body fluid permeability including a fiber assembly made of tow is interposed,
And the squeezing process is given to the said absorbent material which has the said bodily fluid retainability so that it may extend at least to a longitudinal direction, The bodily fluid absorption structure characterized by the above-mentioned.

[Invention of Claim 2]
A body fluid absorption structure provided with an absorbent material having body fluid retention under the top sheet,
Between the surface sheet and the absorbent having a body fluid retention property, an absorbent having a body fluid permeability including a fiber assembly made of tow is interposed,
A bodily fluid diffusing structure is characterized in that a bodily fluid diffusive sheet is interposed between the absorbent material having the bodily fluid retention property and the absorbent material having the bodily fluid permeability.

[Invention of Claim 3]
The bodily fluid absorption structure according to claim 2, wherein the diffusive sheet is subjected to pressing so as to extend at least in a longitudinal direction of an absorbent material having bodily fluid retention.

[Invention of Claim 4]
An absorbent material having humor permeability is interposed between the top sheet and the widthwise central portion of the absorbent material having humor retainability along the longitudinal direction of the absorbent material having humor retainability,
The squeezing process is given along the said longitudinal direction in the site | part which the said absorbent material which has the said bodily fluid permeability is not interposed on the both sides of the absorbent material which has the said bodily fluid permeability. The body fluid absorbing structure according to any one of the above.

[Invention of Claim 5]
An absorbent material having body fluid permeability is interposed between the top sheet and the longitudinal center portion of the absorbent material having body fluid retention,
A pressing process is performed along the width direction of the absorbent having fluid retention, in front and rear of the absorbent having fluid permeability, where the absorbent having fluid permeability is not interposed. The body fluid absorption structure according to any one of claims 1 to 3.

[Invention of Claim 6]
The bodily fluid absorption structure according to any one of claims 1 to 5, wherein a cross-sectional shape of a constituent fiber of a fiber assembly made of tow is a circle or an ellipse.

[Invention of Claim 7]
The body fluid absorbing structure according to any one of claims 1 to 6, wherein the constituent fiber of the fiber assembly made of tow is a cellulose acetate fiber.

[Invention of Claim 8]
The body fluid absorption structure according to any one of claims 1 to 7, wherein a binder is imparted to a fiber assembly made of tow.

  According to the present invention, the body fluid leakage preventing effect can be made perfect.

Embodiments of the present invention will be described below.
[Use]
The body fluid absorbing structure of the present invention can be applied to general articles that absorb body fluids such as urine and blood. Examples of this type of body fluid absorbent article include paper diapers, sanitary napkins, urine-absorbing pads, and incontinence pads.

[Body fluid absorption structure]
(First embodiment)
As shown in FIG. 1, the bodily fluid absorption structure 50 according to the first embodiment includes an absorbent 53A having bodily fluid retention properties under a top sheet 51 located on the use surface side. And the absorbent material 52 which has a body fluid permeability containing the fiber assembly which consists of a tow instead of the nonwoven fabric sheet conventionally having been interposed between the surface sheet 51 and the absorbent material 53A which has a body fluid retainability. Is intervened. The fiber assembly made of tow has a remarkably large body fluid absorption capacity compared to the nonwoven sheet, so that even when a large amount of body fluid is absorbed, such as when the body fluid has to be absorbed repeatedly, it falls into an overflow state. hard.

  In addition, in the main body fluid absorption structure 50, the pressing material such as embossing is applied to the absorbent 53A having body fluid retention so as to extend at least in the longitudinal direction. The body fluid diffuses rapidly along the compressed portion (high density portion) 57. Therefore, the absorbent 53A having body fluid retention absorbs body fluid in a wider area. As a result, the absorbent 52 having the body fluid permeability has a wider outlet in addition to the inlet with respect to the body fluid permeability, and is more difficult to fall into an overflow state. From the above, in the main body fluid absorption structure 50, the movement of body fluid to the end of the article is completely prevented, and the body fluid leakage preventing effect is remarkably excellent.

  Further, since the absorbent 52 having the humor permeability has a wide outlet in addition to the inlet in terms of the humor permeability, the bodily fluid directly permeates (passes) the absorbent 52. Become. Therefore, the absorbent 52 having the humor permeability once returns to the damp state after absorbing the bodily fluid, and the reversal through the surface sheet 51 is prevented, and the touch is good. Become.

  In the present embodiment, the compressed portion 57 extends in the longitudinal direction so as to extend in the longitudinal direction, for example, when applied to an absorbent article such as a paper diaper or a sanitary napkin. In addition, both side edges M, M are formed so as to be located in the center portion in the width direction of the absorbent material 52 having a body fluid permeability. However, the purpose is not limited to this formation method, and for example, as in the body fluid absorption structure 60 shown in FIG. 2, both end edges M and M of the compressed portion 57 are on both side edges of the absorbent material 52 having body fluid permeability. For example, the width may be set appropriately.

  Further, the number of the compressed portions 57 is not particularly limited. For example, in addition to the one line as in the present embodiment, the number of the compressed parts 57 may be two lines, three lines, four lines, or more. it can.

  By the way, the pressing part 57 of the present embodiment is formed so as to extend at least in the longitudinal direction, that is, to extend in a direction intersecting with the width direction of the absorbent 53A having body fluid retention. Is preferred. This is because increasing the body fluid diffusibility in the longitudinal direction contributes to the absorption of the body fluid by the absorbent 53A having body fluid retention in a wider area. Accordingly, the angle at which the compressed portion 57 intersects the width direction of the absorbent 53A having body fluid retention is not particularly limited, and may be appropriately designed from the above viewpoint. In addition to the above, the compression part 57 can be formed by, for example, the same embossing method as disclosed in JP-A-2004-121382.

  In the main body liquid absorption structure 50, the back surface side of the absorbent 53A having body fluid retention can be covered with, for example, a back sheet 54 that does not have body fluid permeability. Thereby, leakage of body fluid to the article back side is prevented.

(Second Embodiment)
As shown in FIG. 3, the body fluid absorbing structure 70 of the second embodiment is a modification of the body fluid absorbing structures 50, 60 of the first embodiment. In the main body liquid absorption structure 70, instead of forming the compressed portion 57 in the absorbent material 53 </ b> A having body fluid retention, between the absorbent material 53 </ b> A having body fluid retention and the absorbent material 52 having body fluid permeability. The body fluid diffusive sheet 58 is interposed. In this body fluid diffusive sheet 58, the body fluid that has permeated through the topsheet 51 and the absorbent material 52 having body fluid permeability is quickly diffused. Therefore, the absorbent material 53A having body fluid retention is in a wider area. Absorption of the body fluid is performed, and the same effect as when the compressed portion 57 is formed is exhibited. Therefore, it is preferable that the body fluid diffusing sheet 58 is interposed so as to extend at least in the longitudinal direction.

  Moreover, since the bodily fluid diffusive sheet 58 is interposed under the topsheet 51 and the absorbent material 52 having humor permeability, according to the present embodiment, the bodily fluid diffuses in a portion that is invisible to the user's eyes. Therefore, it is possible to give a sense of security without giving the user the impression that the body fluid is widely diffused.

(Third embodiment)
As shown in FIG. 4, the body fluid absorption structure 80 of the third embodiment is a modification of the body fluid absorption structure 70 of the second embodiment. In the main body liquid absorption structure 80, the body fluid diffusive sheet 58 is subjected to a pressing process such as embossing so as to extend at least in the longitudinal direction, and a compressed part (a high density part) formed by the pressing process. ) Body fluid diffuses rapidly along 58A, 58A. This is because at least the longitudinal direction of the absorbent material 53A having the body fluid retention property is such that increasing the body fluid diffusibility in the longitudinal direction contributes to absorbing the body fluid in the absorbent material 53A having the body fluid retention property in a wider area. This is because the compressed portion 57 is formed so as to extend in the direction.

  The formation method of this pressing part 58A, 58A ... is not specifically limited, It can be made to be the same as that of the pressing part 57 of 53 A of absorbent materials which have a bodily fluid retainability.

(Fourth embodiment)
As shown in FIG. 5, the body fluid absorption structure 90 of the fourth embodiment is a combination of the body fluid absorption structures 50 and 60 of the first embodiment and the body fluid absorption structure 70 of the second embodiment. It is a thing. In the main body liquid absorption structure 90, the absorbent 53A having body fluid retention is subjected to pressing such as embossing so as to extend at least in the longitudinal direction, and the absorbent 53A having body fluid retention. A body fluid diffusive sheet 58 is interposed between the absorbent 52 having body fluid permeability. Therefore, the diffusibility of the body fluid is synergistically excellent, and in a wider area, the body fluid is absorbed by the absorbent 53A having body fluid retention, and the movement of the body fluid to the article end is completely prevented, The body fluid leakage prevention effect is remarkably excellent.

(Other embodiments)
As mentioned above, in 1st-4th embodiment, it did not show in particular what area | region the absorber 52 which has a humor permeability is interposed. This is to the effect that the intervening region is not particularly limited. That is, the absorbent material 52 having humor permeability can be interposed over the entire surface or a part of the entire surface under the top sheet 51, as is conventionally the case with the nonwoven fabric sheet.

  For example, as shown in FIGS. 8, 9, 12, 13, etc., a form similar to that conventionally used when a non-woven fabric sheet is interposed is used. In the form of interposing only in the central part in the width direction and the central part in the longitudinal direction, as shown in FIG. 10 and FIG. 11, interposing in the central part in the width direction and extending from the front end edge to the rear end edge. The form and the like can be exemplified. According to the former form (FIG. 8, etc.), as shown on the right side of FIG. 8, the thickness when folded in three, for example, by folding the front and rear ends is not increased, and is provided as a product. This is a preferable structure. Moreover, according to the latter form (FIG. 10 etc.), it becomes a preferable structure at the point that a bodily fluid is absorbed in a wide area | region regarding a longitudinal direction.

  By the way, as mentioned above, in the example of FIGS. 8-13, the arrangement | positioning of the absorber 52 which has a body fluid permeability is made into a part, and it is not covered with the absorber 52 which has a body fluid permeability by making it a part. The absorbent material 53A having the body fluid retention property is subjected to a pressing process by embossing or the like (this pressing process can be performed in a state where the topsheet 1 and the like are stacked), thereby forming the groove 56. ing. This is intended to control the diffusion of the body fluid by utilizing the characteristics that the body fluid is difficult to diffuse across the groove 56 and is easy to diffuse along the groove 56.

  Specifically, for example, as shown in FIG. 8, according to the embodiment in which the grooves 56 and 56 are formed along the width direction in front and rear of the absorbent material 52 that is permeable to body fluid, The bodily fluid that has diffused through the absorbent material 52 is retained by the grooves 56, 56, and is less likely to diffuse forward or backward. Therefore, it becomes a structure which is easy to prevent front-back leakage. Further, according to this embodiment, the body fluid is diffused in the width direction quickly. On the other hand, as shown in FIGS. 9-11, according to the form which formed the groove | channels 56 and 56 along the longitudinal direction in the side, front, back, etc. of the absorbent material 52 which has a body fluid permeability, respectively, body fluid permeation | transmission is carried out. The bodily fluid that has diffused through the absorbent 52 having the property is retained by the grooves 56 and 56 and is less likely to diffuse laterally. Therefore, it becomes a structure which is easy to prevent side leakage. Further, according to this embodiment, the body fluid is diffused in the longitudinal direction quickly.

  Of course, the groove | channels 56 and 56 do not have to form in a straight line in the width direction or a longitudinal direction like the above form. For example, as shown in FIG. 11, the rear end portions 56A and 56A may be widened in the width direction. The groove 56 along the direction in which the body fluid is desired to be diffused may be appropriately formed, and the groove 56 perpendicular to the direction in which the body fluid is not desired to be diffused may be formed. Moreover, the groove | channels 56 and 56 do not have to follow any one of the width direction and a longitudinal direction like the above form, For example, as shown to FIG.12 and FIG.13, body fluid permeability | transmittance It can also be formed so as to surround the periphery of the absorbent material 52 having the above. At this time, for example, if the absorbent sheet 55 is interposed as a second sheet or the like, as shown in FIG. 12, the grooves 56 may be formed so that all of them are located on the absorbent sheet 55. As shown in FIG. 13, the front and rear end portions can be formed so as to be separated from the absorbent sheet 55.

  Although the above-mentioned groove 56 can be formed in various modes, it is preferable to form it so as not to straddle the absorbent material 52 having humor permeability, as in the illustrated example. In the present invention, the absorbent material 52 includes a fiber assembly made of tow, and the fiber assembly made of tow is easy to sag due to body fluid absorption. Therefore, the groove is formed on the absorbent material 52 having body fluid permeability. Even if 56 is formed, the absorbent 52 on both sides of the groove 56 also sinks due to body fluid absorption, and the effect of the groove 56 is no longer exhibited. In particular, when the constituent fiber of the fiber assembly made of tow is acetate cellulose, the melting point of acetate cellulose is as high as 230 ° C., and for example, embossing etc. cannot be inserted deeply. The necessity to form so as not to straddle 52 increases.

[Body fluid absorbent article and its production example]
Next, an absorbent article to which the body fluid absorbing structure of the present invention is applied, and a production example thereof will be described.
(First example)
As shown in a plan view in FIG. 14 and a cross-sectional view taken along the line II in FIG. 15, the first absorbent article has a rectangular body fluid retention property between the top sheet 51 and the back sheet 54. An absorbent 53A is interposed, and an absorbent 52 having a body fluid permeability including a fiber assembly made of tow is interposed between the absorbent 53A and the top sheet 1. In addition, also in the main body liquid absorbent article, although the pressing part (high-density part) demonstrated previously is formed in 53 A of absorbent materials which have a bodily fluid retainability, the illustration is abbreviate | omitted. The same applies hereinafter.

  The top sheet 51 and the back sheet 54 have the same shape as the planar outer shape of the article, and both side portions thereof extend laterally from both side edges of the absorbent 53A having body fluid retention. This extension is particularly large in the central portion in the longitudinal direction, and this greatly extended portion is, for example, a folded flap that is folded back in a direction that overlaps the outer surface of clothing such as shorts. Further, at least the front and rear end portions C and C of the topsheet 51 and the backsheet 54 are formed by, for example, hot melt bonding, ultrasonic sealing, heat sealing (thermal fusion), heat press (thermocompression bonding), or a combination thereof. In this example, they are joined by heat sealing.

  On the other hand, the absorbent material 52 having the humor permeability is interposed only in the central portion in the width direction of the absorbent material 53A having the humor retention property, and the front and rear edges thereof are the front and rear of the absorbent material 53A having the humor retention property. It extends to the edge position.

  In manufacturing this absorbent article, for example, as shown in FIG. 16, first, on the surface of the absorbent material 53 </ b> A having a belt-like body fluid retaining property that is conveyed by a conveying means such as a conveyor, Apply an adhesive such as a hot melt adhesive. Next, an absorbent material 52 having a body fluid permeability is placed thereon, and both are joined by the adhesive force of the adhesive.

  The bonded absorbent materials 52 and 53A are conveyed to the cutting machine 22, cut, and become absorbent materials 52 and 53A of a length provided for each article. Therefore, the cutting parts of the absorbent materials 52 and 53A become the front and rear edges of the absorbent materials 52 and 53A provided in each article, and as described above, the front and rear edges of the absorbent material 52 having body fluid permeability are body fluids. It will be in the state extended to the front-and-rear edge position of 53 A of absorbent materials which have retainability.

  While the cut absorbent materials 52 and 53A are being conveyed, the top sheet 51 unwound from the reel 23 and the back sheet 54 unwound from the reel 24 are respectively the front surface of the absorbent material 52 or the back surface of the absorbent material 53A. Are pasted together.

  The absorbent materials 52 and 53A to which the top sheet 51 and the back sheet 54 are bonded can be conveyed to, for example, the embossing device 25 and embossed (in FIG. 14 and FIG. 15, embossing is described). Omitted.) The embossing can be performed, for example, along the longitudinal direction of the article on both sides of the absorbent material 52 having a body fluid permeability (see FIG. 11).

  Absorbents 52 and 53A subjected to appropriate processing such as embossing are conveyed to the heat sealing device 26, and the top sheet 51 and the back sheet 54 bonded to the front and back surfaces thereof are heat sealed. This heat seal bonding is performed at a substantially intermediate position between the absorbent materials 52 and 53A and the absorbent materials 52 and 53A conveyed before and after that, that is, at a position where the absorbent materials 52 and 53A are not interposed. This heat seal location will constitute the front and rear edges of the article.

(Second example)
FIG. 17 is a plan view, and FIG. 15 is a cross-sectional view taken along the line I-I. (This cross-sectional view is the same as the first example. 18) As shown in the sectional view taken along line II-II in FIG. 18, the second absorbent article has substantially the same form as the first absorbent article.

  However, in the present absorbent article, although the absorbent material 52 having the humor permeability is interposed only in the central portion in the width direction of the absorbent material 53A having the humor retention property, the front and rear edges thereof are the topsheet 51 and It extends to the front and rear edge positions of the back sheet 54 (see FIG. 18). In this respect, from the viewpoint of preventing front and back leakage of body fluids and from the viewpoint of ensuring the joining of the front and rear end edges of the topsheet 51 and the backsheet 54, as in the first absorbent article described above. Furthermore, it is preferable that the front and rear edges of the absorbent material 52 having body fluid permeability remain up to the front and rear edge positions of the absorbent material 53A having body fluid retention. However, when there is a need from the viewpoint of manufacturability, the present embodiment can be used.

  Specifically, in manufacturing the present absorbent article, for example, as shown in FIG. 19, an absorbent material 53A having a belt-like body fluid retention property that is conveyed by a conveying means such as a conveyor is first singly used. It can cut and it can be set as the absorber 53A of the length with which each article is equipped. In this regard, as in the first manufacturing example described above, when the absorbent material 52 is joined to the absorbent material 53A and then cut, particularly, the bulk of the absorbent material 53A and the absorbent material 52 is increased as in this embodiment. When physical properties such as softness and softness are different, there is a possibility that cutting cannot be performed accurately and reliably. However, such a problem does not occur if the absorbent material 53A is cut alone as in this production example.

  In the present manufacturing example, the cut absorbent material 53A is coated with an adhesive such as a hot melt adhesive on the surface by the coating device 21, and the absorbent material 52 having body fluid permeability is placed on the adhesive. Both are joined by the adhesive strength of the agent.

  Thereafter, the bonded absorbent materials 52 and 53A are bonded to the top sheet 51 and the back sheet 54, provided with embossing, and heat-sealed as in the first manufacturing example.

  However, in this production example, the heat seal bonding is performed in a state in which the absorbent material 52 having the humor permeability is not cut, so that the absorbent material 52 is interposed in the heat seal portion. . That is, according to this production example, an absorbent article in which the absorbent 52 having humor permeability extends to the front and rear edge positions (article front and rear edge positions) of the top sheet 51 and the back sheet 54 is manufactured. It will be.

(Third example)
As shown in a plan view in FIG. 20 and a cross section taken along the line III-III in FIG. 21, the third absorbent article has almost the same form as the first and second absorbent articles.

  However, in the present absorbent article, the absorbent material 52 having humor permeability is interposed only in the center part in the width direction and in the longitudinal direction of the absorbent material 53A having humor retention, and the absorbent material 52 is Covered by crepe paper 59. In this regard, as described above, when the absorbent 52 having humor permeability is interposed only in the central portion in the longitudinal direction, the thickness when folded in three or the like is reduced, and the product is provided as a product. Although it is preferable (see FIG. 8), there is a possibility that the shape will collapse during use and the intervening effect may not be exhibited. However, if it is covered with crepe paper 59 as in the present article, this possibility is reduced.

The method for coating the crepe paper 59 is not particularly limited, and for example, the method shown in FIG.
That is, in this method, first, an adhesive such as a hot melt adhesive is applied to the surface of the crepe paper 59 that is transported by a transporting means such as a conveyor by the coating device 21. In this step, the crepe paper 59 has a strip shape and is wider than the absorbent material 52 that is permeable to body fluids.

  After the adhesive is applied to the surface of the crepe paper 59, an absorbent material 52 that is permeable to body fluid is then placed on the crepe paper 59, and the two are joined together by the adhesive force of the adhesive. Then, while the crepe paper 59 and the absorbent material 52 are transported by the transport means, in this transport process, the both sides of the crepe paper 59 are wrapped around the both side edges of the absorbent material 52 by the sailor 27. . As a result, the shape of the absorbent material 52 that is permeable to body fluid in the width direction is suppressed by the crepe paper 27, and the shape deformation in the front-rear direction is suppressed by joining with the crepe paper 59. become.

  The absorbent 52 having a body fluid permeability coated with the crepe paper 59 is then cut by the cutting machine 22 to have a length provided for the article.

(Other examples)
As described above, in the first to third examples, an article in which one (one) absorbent material 52 having humor permeability is interposed between the top sheet 51 and the absorbent material 53A having humor retention property, explained. However, the purpose is not to limit the absorbent material 52 having body fluid permeability to one (one).
For example, as shown in FIGS. 23 to 25, two, three, four, or more (books), in the illustrated example, two sheets of the upper absorbent material 52A and the lower absorbent material 52B, As shown in FIG. 27, two, three, four, or a plurality of them are arranged in parallel, and in the illustrated example, three of the central absorbent material 52C and the two side absorbent materials 52D and 52D are arranged in parallel. It can also be interposed.

  There are no particular limitations on the method of interposing the absorbent material 52 having humor permeability, and the method of interposing the absorbent material 52 in parallel. For example, in the case of interposing the layers, as shown in FIG. 26, the upper absorbent material 52A or the lower side 52B is fed between the pair of rolls of the arrangement adjusting means 28 from the upper and lower sides thereof, respectively. State. Under the present circumstances, the absorbent article of the form shown to FIGS. 23-25 can be manufactured by designing the width | variety of 52 A of upper side absorbent materials, and the lower side absorbent material 52B suitably. In the absorbent article in FIG. 23, the lower absorbent material 52B is narrower than the upper absorbent material 52A. Moreover, in the absorbent article of FIG. 24, the upper absorbent material 52A and the lower absorbent material 52B have the same width. Furthermore, in the absorbent article of FIG. 25, the upper absorbent material 52A is narrower than the lower absorbent material 52B.

  On the other hand, in the case where the absorbent material 52 having the humor permeability is interposed in parallel, as shown in FIG. 28, the absorbent material 52C is interposed between the pair of rolls of the arrangement adjusting means 29 from the center and diagonally both sides. Alternatively, 52D and 52D can be fed into a parallel state.

[Material of each component]
(Fiber assembly made of tow)
The fiber assembly made of tow is made of tow (fiber bundle) made of fibers (manufactured using tow as a raw material). Examples of tow fibers include polysaccharides or derivatives thereof (cellulose, cellulose ester, chitin, chitosan, etc.), synthetic polymers (polyethylene, polypropylene, polyamide, polyester, polylactamamide, polyvinyl acetate, etc.), and the like. In particular, cellulose esters and cellulose are preferable.

  As cellulose, cellulose derived from plants such as cotton, linter, and wood pulp, bacterial cellulose, and the like can be used. Regenerated cellulose such as rayon may be used, and the regenerated cellulose may be a spun fiber. The shape and size of cellulose is a continuous fiber that can be regarded as a substantially infinite length and has a long diameter of several millimeters to several centimeters (for example, 1 mm to 5 cm), and a particle diameter of about several microns (for example, 1 to 100 μm). Can be selected from various sizes up to a fine powder. Cellulose may be fibrillated, such as beaten pulp.

  Examples of the cellulose ester include organic acid esters such as cellulose acetate, cellulose butyrate, and cellulose propionate; mixed acid esters such as cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose nitrate acetate; polycaprolactone graft Cellulose ester derivatives such as hydrogenated cellulose ester can be used. These cellulose esters can be used alone or in admixture of two or more. The viscosity average degree of polymerization of the cellulose ester is, for example, about 50 to 900, preferably about 200 to 800. The average substitution degree of the cellulose ester is, for example, about 1.5 to 3.0 (for example, 2 to 3).

  The average degree of polymerization of the cellulose ester can be, for example, 10 to 1000, preferably 50 to 900, more preferably about 200 to 800, and the average degree of substitution of the cellulose ester is, for example, about 1 to 3, preferably 1 to 1. 2.15, more preferably about 1.1 to 2.0. The average degree of substitution of the cellulose ester can be selected from the viewpoint of enhancing biodegradability.

  As the cellulose ester, an organic acid ester (for example, an ester with an organic acid having about 2 to 4 carbon atoms), particularly cellulose acetate is suitable. This is because cellulose acetate can particularly increase the porosity and is suitable for increasing the absorption capacity of body fluids. Specifically, for example, in the case of the absorbent material 52 having body fluid permeability, the porosity (void volume / total volume of the absorbent material) is preferably 60 to 85%, more preferably 75 to 85%. can do.

  The degree of acetylation of cellulose acetate is often about 43 to 62%, but about 30 to 50% is particularly preferable because it is excellent in biodegradability.

  The tow constituent fiber may contain various additives such as a heat stabilizer, a colorant, an oil agent, a yield improver, a whiteness improver, and the like.

  The fineness of the tow constituent fibers can be, for example, about 1 to 16 denier, preferably about 1 to 10 denier, and more preferably about 2 to 8 denier. The tow constituent fiber may be a non-crimped fiber, but is preferably a crimped fiber. The degree of crimp of the crimped fibers can be, for example, 5 to 75, preferably 10 to 50, and more preferably 15 to 50 per inch (2.54 cm). Further, a crimped fiber that is uniformly crimped is often used. When crimped fibers are used, a bulky and light absorbent material can be manufactured, and a tow with high integrity can be easily manufactured by entanglement between the fibers.

  The cross-sectional shape of the tow constituting fiber is not particularly limited, and may be any one of, for example, a circular shape, an oval shape, an irregular shape (for example, a Y shape, an X shape, an I shape, an R shape) or a hollow shape. Also good.

The tow constituent fibers are used, for example, in the form of tows (fiber bundles) formed by bundling about 3,000 to 1,000,000, preferably about 5,000 to 1,000,000 single fibers. can do. The fiber bundle is preferably formed by bundling about 3,000 to 1,000,000 continuous fibers.

  Since the tow has weak entanglement between fibers, it is preferable to use a binder having an action of adhering or fusing the contact portions of the fibers in order to secure a wide gap even when the absorption of body fluid is repeated.

  The binder includes triacetin, triethylene glycol diacetate, triethylene glycol dipropionate, dibutyl phthalate, dimethoxyethyl phthalate, citric acid triethyl ester, and other plastic resins, as well as various resin adhesives, especially thermoplastic resins. Can be used.

  The thermoplastic resin is a resin that exhibits an adhesive force when melted and solidified, and includes a water-insoluble or hardly water-soluble resin and a water-soluble resin. A water-insoluble or poorly water-soluble resin and a water-soluble resin can be used together as necessary.

  Examples of water-insoluble or hardly water-soluble resins include olefinic homo- or copolymers such as polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, polyvinyl acetate, polymethyl methacrylate, methacryl Acid methyl-acrylic acid ester copolymer, acrylic resin such as copolymer of (meth) acrylic monomer and styrene monomer, polyvinyl chloride, vinyl acetate-vinyl chloride copolymer, polystyrene, styrene monomer ( Styrenic polymers such as copolymers with (meth) acrylic monomers, optionally modified polyesters, nylon 11, nylon 12, nylon 610, nylon 612 and other polyamides, rosin derivatives (eg, rosin esters), Hydrocarbon resin (for example, terpene resin Dicyclopentadiene resin, petroleum resin), and hydrogenated hydrocarbon resins. One or two or more of these thermoplastic resins can be used.

  Examples of water-soluble resins include various water-soluble polymers such as polyvinyl alcohol, polyvinyl pyrrolidone, polyvinyl ether, vinyl monomers, and copolymerizable monomers having a carboxyl group, a sulfonic acid group, or a salt thereof. Vinyl water-soluble resins such as copolymers, acrylic water-soluble resins, polyalkylene oxides, water-soluble polyesters, water-soluble polyamides, and the like can be used. These water-soluble resins can be used alone or in combination of two or more.

  Various additives such as stabilizers such as antioxidants and ultraviolet absorbers, fillers, plasticizers, preservatives, and antifungal agents may be added to the thermoplastic resin.

  The fiber assembly can be produced by a known method using tow as a raw material, and at that time, it can be opened in a strip shape so as to have a desired size and bulk as necessary. The opening width of the tow is arbitrary and can be, for example, about 100 to 2000 mm, preferably about 150 to 1500 mm. It is preferable to open the tow because it becomes easier to move the absorbent polymer described later. In addition, the porosity of the absorbent can be adjusted by adjusting the degree of tow opening.

  Tow opening methods include, for example, a method in which tow is spread over a plurality of opening rolls, and the tow width is gradually expanded as the tow progresses, and tow tension (elongation) and relaxation (contraction) And the like, and a method of widening and opening using compressed air can be used.

  FIG. 6 is a schematic diagram showing an example of the opening facility. In this example, the tow 1 serving as a raw fabric is sequentially fed out, and in the process of conveying, the widening means 2 using compressed air and a plurality of spread nip rolls 3, 4, and 5 whose peripheral speed is faster as the roll on the downstream side is combined. After passing through the opened portion and widened / opened, the fiber is passed through the binder addition box 6 to which a binder is added (for example, the box is filled with a mist of triacetin), and the fibers are made of tow having a desired width and density. It is formed as an aggregate 10.

(Surface sheet 51)
In the present embodiment, the top sheet 51 has a property of transmitting body fluid. Therefore, the material of the surface sheet 51 is sufficient if it exhibits this body fluid permeability, and examples thereof include a porous or non-porous nonwoven fabric and a porous plastic sheet. Of these, the nonwoven fabric is not particularly limited as to what the raw fiber is. Examples include synthetic fibers such as polyethylene and polypropylene such as olefins, polyesters and polyamides, recycled fibers such as rayon and cupra, natural fibers such as cotton, and mixed fibers in which two or more of these are used. can do. Furthermore, the nonwoven fabric may be manufactured by any processing. Examples of the processing method include known methods such as a spunlace method, a spunbond method, a thermal bond method, a melt blown method, and a needle punch method. For example, the spun lace method is a preferable processing method when the flexibility and drape properties are required, and the thermal bond method is the preferable processing method when the bulkiness and softness are required.

  Further, the front sheet 51 may be composed of one sheet or may be composed of a laminated sheet obtained by bonding two or more sheets.

(Absorbent material 52 having body fluid permeability)
In the present embodiment, the absorbent material 52 has the property of permeating body fluid, like the top sheet 51. However, it is necessary for the absorbent material 52 to include the above-described fiber assembly made of tow, and it becomes more preferable if it is made only of the fiber assembly made of tow. This is because the fiber assembly made of tow has many voids and increases the absorption capacity of body fluids. Further, at this time, when the cross-sectional shape of the tow constituent fibers is circular or elliptical, the bodily fluid is not caught as in the case of an irregular shape, so that the bodily fluid permeation speed is improved, which is particularly preferable. .

  In the present embodiment, the state of the absorbent 52 is not particularly limited. For example, it can be a single sheet, a laminated sheet formed by laminating two, three, four, or more, or a core.

(Absorbent 53A (53B) having body fluid retention)
In the present embodiment, the absorbent 53A having body fluid retention has a property of retaining the absorbed body fluid. The material of the absorbent 53A is not particularly limited. For example, well-known raw materials, such as what consists of single pulps, such as cotton-like pulp and synthetic pulp, and what mixed the absorbent polymer made into granular powder etc. in the fluff-like pulp, can be illustrated. Of these, the raw material fibers of the pulp are not particularly limited, and examples thereof include cellulose fibers obtained from wood such as mechanical pulp, chemical pulp, and dissolved pulp, and artificial cellulose fibers such as rayon and acetate. it can. However, the wood used as the raw material for cellulose fibers is more preferable in terms of function and price because conifers have longer fiber lengths than hardwoods.

However, the present absorbent 53A becomes more preferable when formed with an absorbent obtained by moving an absorbent polymer into a fiber assembly made of tow (hereinafter, an absorbent having fluid retention in this case, This will be described as reference numeral 53B.) Hereinafter, the absorbent material 53B will be described in detail.
FIG. 7 shows an example of a manufacturing facility for the absorbent 53B, and a continuous belt-like fiber assembly 10 made of tows having a desired width and density is supplied. For this reason, this absorbent material production line can be directly connected to the above-described fiber assembly production line, and the produced fiber assembly 10 can be directly fed into the absorbent material production line.

  The supplied fiber assembly 10 is first passed through a polymer spraying box 11, and after an absorbent polymer, preferably a superabsorbent polymer is sprayed on the upper surface, the fiber aggregate 10 is fed into a suction drum 12. The suction drum 12 has an intake hole in the outer peripheral wall, and is configured to be sucked by a suction pump (not shown) from the inside over a predetermined range in the circumferential direction (a range substantially in the left half in the illustrated example). The fiber assembly 10 on which the superabsorbent polymer is dispersed is guided by the suction drum 12 while being in contact with the outer peripheral surface. In this process, by suction from the suction hole of the suction drum 12, the atmosphere is passed from the superabsorbent polymer application side to the opposite side through the fiber assembly, and the superabsorbent polymer is converted into fiber by the passing force. It is moved into the assembly 10.

  As the superabsorbent polymer, a polymer that absorbs and retains body fluid of its own weight, for example, 10 times or more can be used. Examples include starch-based, cellulose-based and synthetic polymer-based starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, cross-linked sodium carboxymethyl cellulose and acrylic acid. A (salt) polymer or the like can be used. As the shape of the superabsorbent polymer, a commonly used granular material is suitable, but other shapes can also be used.

The amount (weight per unit area) of the superabsorbent polymer can be appropriately determined according to the amount of absorption required for the application of the absorbent material. Therefore, although it cannot be said unconditionally, it can be 3 to 400 g / m ² , for example.

  In a particularly preferred form, after the superabsorbent polymer is sprayed on the fiber assembly 10, the sheet 13 is further covered thereon. In this case, in the suction drum 12, suction is performed from the side surface opposite to the surface of the fiber assembly 10 covered with the sheet 13. In this way, when the sheet 13 is covered prior to suction, a stronger suction force acts on the high-absorbent polymer than when nothing is covered, and the high-absorbent polymer is efficiently gathered into the fiber assembly. It can be moved and dispersed inside the body 10. As the sheet 13, a liquid permeable sheet such as a crepe paper, a nonwoven fabric, a perforated sheet, or a liquid impermeable sheet such as a polyethylene film can be used.

  In order to fix the superabsorbent polymer to the fiber assembly 10, it is also a preferred form that an adhesive is applied to the fiber assembly 10 before the superabsorbent polymer is applied. For this reason, as shown in the figure, the adhesive application device 14 can be disposed on the upstream side of the polymer spray box 11.

  Moreover, when covering the sheet | seat 13, prior to covering the sheet | seat 13, it is also a preferable form to supply an adhesive agent to the surface used as the fiber assembly 10 side of the sheet | seat 13. FIG. For this reason, in the illustrated embodiment, an adhesive application device 15 is provided in the sheet supply path for the suction drum. When this form is adopted, the superabsorbent polymer exposed on the surface of the fiber assembly 10 is fixed to the sheet 13 via an adhesive, and the non-adherent superabsorbent polymer moves into the fiber assembly 10 by subsequent suction. Will come to be.

  Furthermore, it is also a preferable form to supply the adhesive to the fiber assembly 10 after suction, that is, after moving the superabsorbent polymer. For this reason, in the illustrated embodiment, an adhesive application device is provided on the exposed side surface of the fiber assembly 10 on the downstream side of the suction drum 12 (the surface opposite to the sheet 13 side, the upper surface in the drawing). When this form is employed, the superabsorbent polymer that has moved to the side opposite to the polymer application side of the fiber assembly 10 among the applied superabsorbent polymer can be fixed to the fiber assembly 10. Further, when the exposed side surface of the fiber assembly 10 is covered with a separate sheet or both sides of the sheet 13 are wrapped around both ends of the fiber assembly 10, the height moved to the exposed side surface of the fiber assembly 10 is increased. The superabsorbent polymer can be fixed to the sheet 13 with the absorbent polymer.

  Any one or a combination of two or more of these adhesives can be applied. As the adhesive, an adhesive made of a thermoplastic resin (specific examples are as described above) can be suitably used.

  Then, the fiber assembly 10 thus provided with the superabsorbent polymer is covered with, for example, a separate sheet, or folded by turning both sides of the sheet 13 around both ends of the fiber assembly 10 with a sailor as shown in the figure. After coating, the absorbent material 53B is cut into a predetermined length.

  On the other hand, the quantitative arrangement, density distribution, and fiber density of the superabsorbent polymer with respect to the fiber assembly 10 are preferably uniform for the purpose of general purpose, but the purpose is to exhibit special absorption characteristics. In such a case, it is also preferable to bias in accordance with the purpose.

  Specifically, when applied to the illustrated form, in the polymer spraying box 11, the spraying amount can be biased in the plane direction. In particular, in body fluid absorbent articles such as paper diapers and sanitary napkins, it is often desired to increase the amount of absorption in the central portion in the width direction of the absorbent material. A large amount of superabsorbent polymer can be sprayed to the center part in the width direction of 10 than the side parts.

  Further, by biasing the suction force in the suction drum 12, the higher the suction force, the higher the amount of superabsorbent polymer located on the suction drum 12 side. Can be biased. For example, the density of the superabsorbent polymer at the center in the width direction of the fiber assembly 10 can be increased by making the suction force at the center in the width direction of the suction drum 12 higher than the sides (or longer suction time). Can be higher than the sides. In such a structure, the absorption rate of the central portion is slow and the absorption rate of both side portions is high, so that when used in a body fluid absorbent article, the body fluid tends to spread throughout the absorber, that is, diffusibility. Will improve.

  Furthermore, since the fiber assembly 10 made of tow is easy to flow the liquid along the continuous direction of the fibers, it is possible to impart special absorption characteristics by biasing the density of the fibers. Such a means for biasing the fiber density can be achieved by performing uneven fiber opening at the time of manufacturing the fiber assembly 10, or by partially using a plurality of tows. As a specific method of biasing, for example, the fiber density at the center portion in the width direction of the fiber assembly 10 can be biased so as to be higher than both side portions. In this case, more liquid flows along the continuous direction of the fibers at the center in the width direction of the fiber assembly 10.

  In the present embodiment, the state of the absorbent 53A (53B) is not particularly limited. For example, a core shape, a single sheet shape, a laminated sheet shape in which a plurality of two, three, four, or more layers are laminated can be used.

(Body fluid diffusive sheet 58)
In the present embodiment, the body fluid diffusive sheet 58 has a property of diffusing body fluid. Therefore, the material of the body fluid diffusive sheet 58 is sufficient as long as it exhibits this body fluid diffusibility, and examples thereof include the same material as the top sheet 51 and the same material as the absorbent material 52 having body fluid permeability. can do. However, spunlace, pulp nonwoven fabric, mixed sheet of pulp and rayon, point bond or crepe paper are particularly preferable.

(Back sheet 2)
In the present embodiment, the back sheet 54 has a property of not transmitting body fluid. Accordingly, the material of the back sheet 54 is sufficient if it exhibits this body fluid impermeability, for example, an olefin resin such as polyethylene or polypropylene, a laminated nonwoven fabric in which a nonwoven fabric is laminated on a polyethylene sheet, or a waterproof film is interposed. For example, a non-woven fabric that is substantially impervious to liquids (in this case, the waterproof film and the non-woven fabric constitute the back sheet 54 that is impermeable to bodily fluids). Of course, in addition to this, materials having liquid impermeability and moisture permeability, which have been used and used in recent years from the viewpoint of preventing stuffiness, can also be exemplified. As the sheet of the material having liquid impermeability and moisture permeability, for example, an inorganic filler is kneaded in an olefin resin such as polyethylene or polypropylene, and the sheet is formed, and then stretched in a uniaxial or biaxial direction. Examples of the microporous sheet obtained in this way can be given.

Next, based on an Example, the effect of this invention is clarified.
The inventors of the present invention conducted a test for measuring the moisture absorption speed of the body fluid absorption structure 50 of the first embodiment and the conventional body fluid absorption structure. In the body fluid absorbing structure 50, a fiber assembly made of tow made of cellulose acetate as a raw material was used as the absorbent 52 having body fluid permeability. Moreover, in the conventional bodily fluid absorption structure, it replaced with the absorbent material 52 which has a bodily fluid permeability, and used the nonwoven fabric sheet. The amount of moisture to be absorbed was six types of 5 cc, 10 cc, 15 cc, 20 cc, 25 cc, and 30 cc. However, when the water content is 10 cc or more, the method of repeating the operation of absorbing 5 cc using a cylinder 2 to 6 times at intervals of 20 minutes instead of absorbing the water at once. According. The time (seconds) required for absorption is shown in Table 1.

  From Table 1, it can be seen that the cellulose acetate is used as a raw material, and the absorption speed is faster. In particular, when the amount of absorption increases, the time required for the absorption varies greatly. From this, it can be seen that it is preferable to use the absorbent material 52 having humor permeability including a fiber assembly made of tow made of cellulose acetate instead of the nonwoven fabric.

  The present invention is applicable to absorbent articles such as disposable diapers, sanitary napkins, urine pads, and incontinence pads.

It is a cross-sectional schematic diagram of the bodily fluid absorption structure of 1st Embodiment. It is a cross-sectional schematic diagram of the bodily fluid absorption structure of 1st Embodiment. It is a cross-sectional schematic diagram of the bodily fluid absorption structure of 2nd Embodiment. It is a cross-sectional schematic diagram of the bodily fluid absorption structure of 3rd Embodiment. It is a cross-sectional schematic diagram of the bodily fluid absorption structure of 4th Embodiment. It is the schematic which shows the manufacturing flow of a fiber assembly. It is the schematic which shows the manufacture flow of the absorber which has a bodily fluid retainability. It is a top view of the bodily fluid absorption structure of other embodiment. It is a top view of the bodily fluid absorption structure of other embodiment. It is a top view of the bodily fluid absorption structure of other embodiment. It is a top view of the bodily fluid absorption structure of other embodiment. It is a top view of the bodily fluid absorption structure of other embodiment. It is a top view of the bodily fluid absorption structure of other embodiment. It is a top view of the bodily fluid absorptive article of the 1st example. It is the II sectional view taken on the line of FIG. It is the schematic which shows the manufacturing flow of the bodily fluid absorbent article of a 1st example. It is a top view of the bodily fluid absorptive article of the 2nd example. It is the II-II sectional view taken on the line of FIG. It is the schematic which shows the manufacturing flow of the bodily fluid absorptive article of the 2nd example. It is a top view of the bodily fluid absorptive article of the 3rd example. It is the III-III sectional view taken on the line of FIG. It is the schematic which shows the manufacturing flow which coat | covers a crepe paper on an absorber. It is sectional drawing of the bodily fluid absorbent article of another example. It is sectional drawing of the bodily fluid absorbent article of another example. It is sectional drawing of the bodily fluid absorbent article of another example. It is the schematic which shows the manufacturing flow of the bodily fluid absorbent article of another example. It is sectional drawing of the bodily fluid absorbent article of another example. It is the schematic which shows the manufacturing flow of the bodily fluid absorbent article of another example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Tow, 10 ... Fiber assembly, 11 ... Polymer dispersion box, 12 ... Suction drum, 13 ... Sheet, 14-16 ... Adhesive application apparatus, 50, 60, 70, 80 ... Body fluid absorption structure, 51 ... Top sheet 52 ... Absorbing material having body fluid permeability, 53A, 53B ... Absorbing material having body fluid retaining property, 54 ... Back sheet.

Claims (8)

A body fluid absorption structure provided with an absorbent material having body fluid retention under the top sheet,
Between the surface sheet and the absorbent having a body fluid retention property, an absorbent having a body fluid permeability including a fiber assembly made of tow is interposed,
And the squeezing process is given to the said absorbent material which has the said bodily fluid retainability so that it may extend at least to a longitudinal direction, The bodily fluid absorption structure characterized by the above-mentioned. A body fluid absorption structure provided with an absorbent material having body fluid retention under the top sheet,
Between the surface sheet and the absorbent having a body fluid retention property, an absorbent having a body fluid permeability including a fiber assembly made of tow is interposed,
A bodily fluid diffusing structure is characterized in that a bodily fluid diffusive sheet is interposed between the absorbent material having the bodily fluid retention property and the absorbent material having the bodily fluid permeability.   The bodily fluid absorption structure according to claim 2, wherein the diffusive sheet is subjected to pressing so as to extend at least in a longitudinal direction of an absorbent material having bodily fluid retention. An absorbent material having humor permeability is interposed between the top sheet and the widthwise central portion of the absorbent material having humor retainability along the longitudinal direction of the absorbent material having humor retainability,
The squeezing process is given along the said longitudinal direction in the site | part which the said absorbent material which has the said bodily fluid permeability is not interposed on the both sides of the absorbent material which has the said bodily fluid permeability. The body fluid absorbing structure according to any one of the above. An absorbent having humor permeability is interposed between the top sheet and the longitudinal center of the absorbent having humor retention,
Squeezing is performed along the width direction of the absorbent having fluid retention, at the front and rear of the absorbent having fluid permeability, where the absorbent having fluid permeability is not interposed. The body fluid absorption structure according to any one of claims 1 to 3.   The bodily fluid absorption structure according to any one of claims 1 to 5, wherein a cross-sectional shape of a constituent fiber of a fiber assembly made of tow is a circle or an ellipse.   The body fluid absorbing structure according to any one of claims 1 to 6, wherein the constituent fiber of the fiber assembly made of tow is a cellulose acetate fiber.   The body fluid absorption structure according to any one of claims 1 to 7, wherein a binder is imparted to a fiber assembly made of tow.

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