WO2013084752A1 - Sheet and absorbent article using same - Google Patents

Abstract

This sheet (10) has a first protruding section (1) which protrudes to a first surface side on the planar view side and has an internal space (18), and a second protruding section (2) which protrudes to a second surface side on the opposite side to the first surface side and has an internal space (28). The first protruding section (1) and the second protruding section (2) are arranged so as to consecutively alternate, having a wall section (3) therebetween, in each different direction intersecting in the planar view of the sheet (10), and spread in the sheet planar direction. The internal space (18) of the first protruding section (1) opens to the second surface side, and the internal space (28) of the second protruding section (2) opens to the first surface side. The wall section (3) extending from the peak of the first protruding section (1) to the peak of the second protruding section (2) has a section (7) narrowing towards the internal space (28) of the second protruding section (2).

Description

Sheet and absorbent article using the same

The present invention relates to a sheet with protrusions and an absorbent article using the same.

Absorbent articles such as sanitary napkins, panty liners, disposable diapers, etc., depending on the function, those provided with a protruding part on one side of the sheet material, those provided with a line-like protruding part, many Products with holes have been developed. For example, Patent Document 1 discloses a laminated sheet having a protruding portion extending in a streak shape on one side of a sheet material and having a cross-section (substantially semicircle) in cross section. Thereby, it is supposed that it can be used, for example as a cushioning surface sheet. Patent Document 2 discloses a sheet having a large number of frustoconical protrusions protruding from one side of the sheet as embossed sheets as a sheet having a high compression recovery rate. Patent Document 3 is a sheet composed of a two-layer sheet that does not substantially expand and contract, and the upper sheet has a large number of rectangular parallelepiped protrusions. A surface sheet of an absorbent article having a space between the two is disclosed. With this sheet, it is supposed that the liquid can be captured in the closed hollow portion in the convex portion, and the liquid leakage prevention and concealing properties are improved.

JP 2008-25081 A JP 2001-20168 A JP 2004-174234 A

The present invention projects to the first surface side on the side of the sheet in plan view, and has a first projecting portion having an internal space, projects to the second surface side opposite to the first surface side, and A second projecting portion having a space, and the first projecting portion and the second projecting portion continuously extend in the sheet plane direction through the wall portions alternately in different directions intersecting in plan view of the sheet. The internal space of the first protrusion is opened to the second surface side, the internal space of the second protrusion is open to the first surface side, and the second space extends from the top of the first protrusion. The wall portion connected to the top portion of the protruding portion provides a sheet having a portion constricted toward the internal space of the second protruding portion.

The above and other features and advantages of the present invention will become more apparent from the following description.

It is a perspective view showing typically a sheet as one embodiment of the present invention by a partial section. It is sectional drawing which expands and shows the area | region II in the sheet | seat of FIG. FIG. 3 is an enlarged cross-sectional view taken along line III-III in the sheet of FIG. FIG. 4 is an enlarged cross-sectional view taken along the line IV-IV in the sheet of FIG. 1. It is a drawing substitute photograph which imaged the section of the sheet of this embodiment. It is an expanded sectional view expanding and showing typically a thickness direction section about the 2nd projection part and its internal space. It is explanatory drawing which expands and shows the outer surface of a 2nd protrusion part typically. It is explanatory drawing which shows typically a mode that the sheet | seat of this embodiment was pressed and the constriction part became the lamination | stacking thickness part. It is explanatory drawing which shows typically the relationship between a 1st protrusion part and a 2nd protrusion part by planar view. It is explanatory drawing which shows typically a mode when the sheet | seat of this embodiment is pressed. It is explanatory drawing which shows typically the 2nd protrusion part which has an ellipse plane shape with a long axis and a short axis, (a) is a top view, (b) is a front view, (c) is a cross-sectional side view FIG. It is explanatory drawing which expands and shows a part of FIG. It is explanatory drawing which expand | deploys and shows the state of the fiber orientation of a wall part typically. It is explanatory drawing which shows typically the state of the fiber orientation of a 2nd protrusion part by planar view. It is a perspective view showing typically a diaper of one embodiment of the present invention.

The present invention relates to a sheet excellent in cushioning and deformability and having good air permeability. Moreover, this invention relates to the absorbent article excellent in the excretion collection property using the said sheet | seat.

The inventors of the present invention have conducted extensive research and development for the purpose of searching for a form different from the above-described conventional one and providing a sheet capable of imparting a property different from the conventional one and a better function. Specifically, the production and properties / functions of continuous sheets having portions protruding on both the front and back surfaces as well as on one side of the sheet material were examined. The present invention has been completed based on these findings.

FIG. 1 is a partial cross-sectional perspective view schematically showing a main part of a sheet as a preferred embodiment of the present invention. 2 is an enlarged view of a region II in the sheet of FIG. 1, and FIGS. 3 and 4 are enlarged sectional views showing a section taken along line III-III and a section taken along line IV-IV, respectively. The sheet 10 is preferably applied as a sheet member of an absorbent article such as a sanitary napkin or a disposable diaper, and the first surface side z ₁ (see FIG. 2) is used toward the wearer's skin surface. it is preferable to use by placing the second adhesive surface z ₂ to the article inside of the absorber (not shown) side. Hereinafter, although it explains considering the embodiment which uses the 1st surface side toward the wearer's skin surface as mentioned above of nonwoven fabric 10 shown in the above-mentioned drawing, the present invention is limited and interpreted by this Absent.

As shown in FIG. 1, the sheet 10 according to the present embodiment has a large number of first protrusions 1 obliquely intersecting with each other in two vertical and horizontal directions on the first surface side when the sheet 10 is viewed in plan. The arrangement is extended (hereinafter, this arrangement may be referred to as an oblique grid arrangement). The lattice arrangement may be orthogonal (90 °), and in that case, the lattice arrangement may be distinguished as an orthogonal lattice arrangement. In the present embodiment, it is preferable that the first direction (x) and the second direction (y) in the plane intersect at an angle of 30 ° to 90 °. Further, the sheet 10 is formed with a number of second projecting portions 2 projecting to the second surface side opposite to the first surface side. The second protrusions 2 are also arranged in an oblique grid pattern, but may be an orthogonal grid pattern. Since the preferable range of the crossing angle is determined along with the first protrusion 1, it is the same as described above. The first projecting portion 1 and the second projecting portion 2 project in directions opposite to each other with respect to the sheet surface.

And the 1st protrusion part 1 and the 2nd protrusion 2 are distribute | arranged so that it may spread in the surface direction continuously via the wall part 3 by each in the different direction which cross | intersects the planar view of the sheet | seat 10. As shown in FIG. In Figure 1, s ₁ direction and s in _two directions the first projecting portion 1 and the second protrusion 2 are continuously arranged in the sheet plane direction alternately. Furthermore, not only in a plan view but also in a side view, the first protrusions and the second protrusions 2 are not located at the same position, that is, they are arranged alternately so as not to overlap (see FIG. 2).
As described above, the first projecting portion 1 and the second projecting portion 2 that are arranged to extend in the first direction (x direction) and the second direction (y direction) in the plane are continuous without contradiction in the sheet plane direction. And the sheet | seat 10 is comprised. Here, “continuous without contradiction” means that when a specific shape portion is continuous and becomes planar, it is not refracted or discontinuous, and the whole is continuous with a gentle curved surface.

The “continuous” means that the sheet material is formed without any substantial breakage of the sheet material, for example, there are no interrupted portions or hole regions partially lacking the sheet material. Means. However, micropores such as interfiber pores are not included in the pore region. When distinguishing this, for example, the hole region can be defined as having a circle equivalent diameter of 1 mm or more. The term “continuous” includes a laminated sheet. In the present embodiment, a single-layer sheet that is not laminated is shown as a preferred embodiment. Further, the meaning of the word “continuous” can also be expressed as the surface on the first surface side z ₁ and the surface on the second surface side z ₂ of the nonwoven fabric being substantially continuous. The term “substantially continuous” here means that, as described above, the pores may be included and the micropores may be smaller than that without impairing the effects of the present invention.

In the seat of the present invention, the arrangement form of the first protrusions and the second protrusions is not limited to the above, and may be any form that can be arranged in an arrangement that can be continued without contradiction. Alternatively, six second protrusions may be arranged at the apexes of the hexagon, and the pattern may be spread in the plane. In this case, since the number of the second protrusions exceeds the number of the first protrusions, the second protrusions are adjacent to each other. However, as long as a continuous sheet state is formed as a whole, this is the case. Such an arrangement is included in the meaning that the first protrusions and the second protrusions are arranged alternately.

In the present embodiment, the first projecting portion 1 and the second projecting portion 2 have a truncated cone shape or hemispherical shape with rounded top portions 11 and 21. More specifically, the protruding shape of the first protruding portion 1 is not sharp but rather hemispherical, while the protruding shape of the second protruding portion 2 is sharper and the top 21 has a round cone. It has a truncated cone shape. In the present embodiment, the protruding portion is not limited to the above shape, and any protruding shape may be used. For example, various cone shapes (in this specification, the cone shape is a cone, a truncated cone, a pyramid, a pyramid It is practical to include a table, a slanted cone, etc.).

The first projecting portion 1 and the second projecting portion 2 hold frustoconical or hemispherical internal spaces 18 and 28 having rounded tops similar to the outer diameter thereof. The internal space 18 of the 1st protrusion part 1 is open | released by the 2nd surface side, and the internal space 28 of the 2nd protrusion part 2 is open | released by the 1st surface side. Moreover, each internal space 18 and 28 is separated through the ridge part 6, and is formed as a space which is not substantially continuous (refer FIG. 2).
On the other hand, a wall portion 3 is formed between the first protruding portion 1 and the second protruding portion 2 in the sheet thickness direction, and both protruding portions are continuous through the wall portion 3 or the ridge portion 6. It is structured. The wall 3 is a portion that connects the first protrusion 1 and the second protrusion 2. The wall 3 is not clearly distinguished from the two protrusions but is a skirt extending from the tops 11 and 21 of the two protrusions. That is, the wall part 3 is a shared part of both protrusion parts, and is a part of both protrusion parts. Moreover, the wall part 3 is a part which separates the internal space 18 of the 1st protrusion part 1, and the internal space 28 of the 2nd protrusion part adjacent to this, and is also a part which makes the outer edge of both internal space.

As shown in FIG. 5, in the sheet 10, the wall 3 that forms the second projecting portion 2 has a portion that is constricted toward the internal space 28 of the second projecting portion 2 (hereinafter referred to as the constricted portion 7). Is formed. FIG. 5 is a drawing-substituting photograph in which a cross section of the sheet 10 of the present embodiment is imaged. In FIG. 5, the arrangement | positioning area | region of the narrow part 7 is shown with the dashed-dotted line, and the code | symbol 7 is attached | subjected. As shown in FIG. 5, the constricted portions 7 are preferably formed in pairs at least at two places. That is, the pair of constricted portions 7 are literally portions (B) narrower than the width (A) of the cross-sectional parabola of the second projecting portion 2. The width (B) is the distance between the inner walls at a position where the pair of constricted portions 7 and 7 are closest to each other, and the width (A) is the widest width between the wall portions 3 near and below the constricted portion 7. It is the distance between the inner walls of the part.
Regarding the narrow width of the constricted portion 7, for example, a form as shown in FIG. FIG. 6 is an enlarged cross-sectional view schematically showing an enlarged cross section in the thickness direction of the second protrusion 2 and the internal space 28 thereof. In FIG. 6A, the cross-sectional shape of the second protrusion 2 is a parabola, and the constricted part 7 is narrower (B ₁ ) than the width (A ₁ ) of the second protrusion. In FIG. 6B, the vicinity of the top portion 21 has a swelled shape, and the constricted portion 7 is narrower (B ₂ ) than the width (A ₂ ) of the second protruding portion. FIG 6 (c) has a shape in the vicinity of the top portion 21 is smaller than the upper, constricted portion 7 relative to the width of the second projecting portion (A ₃₎ is narrower (B _3). The ratio (B / A) of each cross-sectional width is preferably 0.2 to 0.9, and more preferably 0.4 to 0.8. From the viewpoint of liquid permeability, 0.2 or more is preferable, and from the viewpoint of cushioning property, 0.8 or less is preferable.

Speaking from another viewpoint about the relationship between the widths (A) and (B), in the sheet thickness (T) section of the second projecting portion 2 passing through the pair of constricted portions 7, the area around the top portion 21 of the second projecting portion 2. It is defined as a relationship in which the constricted portion 7 is arranged inside the curve u based on the curvature. That is, the narrow portion 7 is defined as narrower than the width formed by the curve u. The width formed by the curve u is the width at the narrow (B) height position of the constricted portion 7 (see FIG. 6). Referring to FIG. 6 as an example of this definition, in FIG. 6A, the curve u matches the shape of the entire second protrusion 2 and the constricted portion 7 with respect to the width (A ₁₁ ) of the wall 3. Is narrow (B ₁ ). In FIG. 6B, the width of the curve u is wider than the width of the wall portion extending from the top portion 11. That is, it is a drawstring shape in which the vicinity of the top 21 of the internal space 28 of the second protrusion 2 is enlarged. In this example, the constricted portion is narrow (B ₂ ) with respect to the width (A ₂₁ ) of the curve u. In FIG. 6C, the width of the curve u is narrower than the width of the wall portion extending from the top portion 11. In this example, the constricted portion is narrow (B ₃ ) with respect to the width (A ₃₁ ) of the curve u.
As in the above example, the constricted part 7 is arranged so that the internal space 28 is squeezed at the upper part with respect to the space area around the top part 21 of the internal space 28 of the second projecting part 2. preferable. From this viewpoint, the ratio (B ₁ / A ₁₁ ) in FIG. 6A and the ratio (B ₃ / A ₃₁ ) in FIG. 6C are preferably 0.15 to 0.85, and 0.3 to 0 More preferred is .75. The ratio (B ₂ / A ₂₁ ) in FIG. 6B is preferably from 0.1 to 0.8, and more preferably from 0.25 to 0.7. From the viewpoint of liquid permeability, 0.15 or more is preferable, and from the viewpoint of cushioning property, 0.85 or less is more preferable.

The constricted part 7 can be arranged at an arbitrary height with respect to the sheet thickness (T) in the wall part 3 connecting the top part 11 of the first projecting part 1 and the top part 21 of the second projecting part 2. Among them, in the definition of the following three sections, the constricted portion 7 is arranged in the range closer to the top of the regions P ₂ to P ₃ or the boundary between the region p ′ ₂ and the region p ′ ₃ where the curvature of the top portion 21 changes. It is preferable (see FIG. 2). Further, in the definition of the following two sections, it is preferable that the constricted portion 7 is arranged on the half thickness t ₂ side of the center line (center plane) m or m ′ (see FIG. 2).
More specifically, the ratio (T ₇ / T) of the height (T ₇ ) from the top 21 of the constricted part 7 to the sheet thickness (T) is preferably 0.1 to 0.9, 0.2 ~ 0.8 is preferred. From the viewpoint of cushioning properties, 0.1 or more is preferable, and from the viewpoint of cushioning properties or touch, 0.9 or less is preferable.

(3 categories)
The three sections are typically defined by dividing the wall 3 into three equal parts of the sheet thickness (T) (P ₁ = P ₂ = P ₃ ). Or when the kurtosis or curvature of the top part of the 1st protrusion part 1 and the 2nd protrusion part 2 is different like FIG.6 (b), the wall part 3 is a comparatively narrow part which became linear in the cross section. The region P ′ ₂ and the curved and rounded region can be classified as P ₁ and P ′ ₃ , respectively. That is, the radius of curvature of the top 21 of the second protrusion top 2 is larger than the radius of curvature of the top 11 of the first protrusion 1 (the curvature is small). This latter section can also be applied in FIG. 6C, in which the radius of curvature of the top portion 21 of the second protruding portion top portion 2 is smaller than the radius of curvature of the top portion 11 of the first protruding portion top portion 1 (the curvature is large). ).

(2 categories)
The half thickness (t ₁ ) on the first surface side and the half thickness (t ₂ ) on the second surface side are the same as described above. Basically, the line obtained by dividing the sheet thickness (T) into two equal parts is the center line ( It is assumed that the center plane is m and the thicknesses (t ₁ , t ₂ ) are equal. Alternatively, when there is a difference in the kurtosis or the radius of curvature at the top of the first projecting portion 1 and the second projecting portion 2, the definition is made by dividing the position by the position m ′ evaluated as the center of the straight section of the wall portion. can do. In the example of FIG. 6C, according to the definition of the latter, the half thickness t ₁ on the first surface side <the half thickness t ₂ on the second surface side.

Next, the preferable shape in the wall surface 3 surface of the narrow part 7 is demonstrated.
The constricted part 7 may be in a part of the circumferential direction of the surface of the wall part 3 or may be in the entire circumference. In the case where it is in a part, it is preferable to be at two places facing each other through at least the internal space 28.
When the constricted portions 7 and 7 are arranged in a pair, each constricted portion 7 has a predetermined shape on the curved surface of the wall portion 3 forming the second projecting portion 2 as shown in FIGS. It may be formed in a stripe shape in the width, or may be formed in a dot shape as shown in FIG. In FIG. 7 (a), the constricted portion 7 approximates the semicircular length of the outer periphery of the wall 3 but is shorter than that, and in FIG. 7 (b), the constricted portion is shorter than that of (a). 7 In the seat 10, from the viewpoint of imparting deformability due to the cushioning property described later and the spring property of the constricted portion 7, the constriction is formed in a streak shape with a predetermined width as shown in FIGS. 7 (a) and (b). preferable. With respect to this predetermined width, the semicircular length of the outer periphery of the second projecting portion 2 at the height position where the constricted portion 7 is disposed is (C), and the peripheral length of the constricted muscle of the constricted portion 7 is (D). In this case, these ratios (D / C) are preferably 0.2 to 0.9, more preferably 0.3 to 0.8, from the viewpoint of cushioning properties and the like.

Here, the operation based on the basic structure of the sheet 10 described above will be described.
(Cushioning and deformability)
The sheet 10 has portions (first and second protrusions) protruding on both sides as well as on the front and back sides. In both protrusion parts, the top part 11, the top part 21, and the periphery thereof are shaped like a convex lens with roundness. Therefore, even if the sheet 10 is pressed in the sheet thickness (T) direction, the force is distributed between the protruding portions on both sides, and the cushioning characteristic peculiar to the structure is exhibited. With regard to this point, for example, conventional line-like protrusions and single-sided protrusions will inevitably exhibit elasticity as lines or surfaces, but according to this embodiment, they also follow three-dimensional movements well. Thus, the three-dimensional cushioning is supported on both sides by points (increase or decrease the area in a circular shape by pressure change).
Further, as described above, the sheet 10 is formed with the constricted portion 7 that enters the inner space 28 of the second projecting portion 2 in the wall portion 3. The constricted portion 7 has an effect of dispersing and relaxing the pressing in the sheet thickness (T) direction. For example, the pressure from the first projecting portion 1 side tries to reach the top portion 21 of the second projecting portion 2 from the top portion 11 through the wall portion 3, but the stress is distributed at the curved portion of the constricted portion 7. The stress propagation to the second protrusion 2 is alleviated. Thereby, in combination with the rounded protrusions, the seat 10 becomes difficult to sag and an excellent cushioning property is obtained. Further, the constricted portion 7 exhibits the spring property against the force in the plane direction, and the sheet 10 is excellent in elastic deformation and shape recoverability at the time of weight removal. For example, when a planar force is applied to the surface of the first projecting portion 1, the first projecting portion 1 deforms flexibly corresponding to the stress starting from the constricted portion 7, and also due to the spring property of the constricted portion 7. It is easy to be restored to the shape. On the other hand, since the force is relieved by the constricted portion 7 on the second projecting portion 2 side, the deformation is unlikely to occur and the side is stable.
From the viewpoint of maintaining the cushioning property and the deformability as described above, the constricted portion 7 is preferably a rounded shape with as few corners as possible. Thereby, even if it repeats, a stress is not easily concentrated on the constriction part 7, but it is relieve | moderated suitably, and a favorable spring characteristic is exhibited.

(Breathable)
In the sheet 10, there are open internal spaces on the first surface side and the second surface side. When this sheet 10 is applied to an absorbent article, a large number of opened internal spaces can diffuse moisture generated from the wearer, while effectively diffusing vapor emanating from the absorber side.
(Excretion collection)
Since the sheet 10 has the internal spaces 18 and 28, when used as a sheet member of the absorbent article, the sheet 10 can collect and deal with these in various forms according to the physical properties of the excretory liquid and excrement. For example, when explained by assuming that the first surface z ₁ of the sheet 10 of Figure 1 and the skin face side, if a low excrement viscosity high permeability, its excrement temporary internal space 28 is Stock Is done. Even a liquid having a low viscosity and easily diffusing is dispersed and temporarily stored in the plurality of internal spaces 28. Thus, the liquid collected in the internal space 28 is difficult to return to the first surface 1 side due to the difficulty of sag of the seat 10 due to the above-described cushioning property or the like. Further, the narrow constricted portion 7 in the second projecting portion 2 acts as an internal projection for the internal space below it, and acts to suppress the return of the liquid. Moreover, the part which first hits the skin surface is the top part 11 of the 1st protrusion part 1, The said excretion liquid thru | or excrement collected are made difficult to contact skin. Thereby, after excretion of urine, stool, menstrual blood and vaginal discharge, a very good and smooth feeling can be sustained in a wide range.

Regarding the air permeability and collection property of the sheet 10, the constricted portion 7 is preferably deformed into a laminated thickness portion 71 in which the sheet material is folded without spreading in the plane direction even under high pressure. For example, it is preferable that the constricted portion 7 becomes a triple laminated thickness portion 71 as shown in FIG. Since the laminated thickness portion 71 forms a certain height in the thickness direction, the internal spaces 18 and 28 remain even partially. Thereby, air permeability is maintained, a liquid holding region remains, and liquid outflow is suppressed.
As the structure of the sheet 10 in which the laminated thickness portion 71 is preferably formed, the sheet thickness is thinner than the pitch length between the protrusions on the sheet, and is less than a quarter of the pitch length between the protrusions on the sheet. Thickness is preferred.

(touch)
The sheet 10 has first and second protrusions in both directions, and the top is rounded. Therefore, when the skin comes into contact with the sheet 10, a soft and good touch is realized with respect to the skin. In addition, the contact point with the pressure at the time of mounting increases or decreases in a planar shape, making it possible to suppress the shape deformation of the entire sheet with respect to the pressure while reducing the shape deformation from the pressure deformation. Can be easy. There also exists an effect | action resulting from said favorable cushioning property, and a unique favorable touch is obtained with the effect | action by contact with skin like a point contact. Moreover, the point contact mentioned above has an effect also when excretion etc. are received, and the smooth touch is implement | achieved.

In the sheet 10, in order to make the above-mentioned cushioning property and deformability more reliable, and to achieve both of these characteristics and a soft touch, the compression hardness (LC) is preferably 0.01 to 0.35, Furthermore, it is 0.05 to 0.3, more preferably 0.1 to 0.25. Since the compression hardness (LC) is in the above range, the sheet 10 can have an appropriate gap, and can achieve high absorption performance while maintaining flexibility.

(Measurement method of compression hardness (LC))
The compression hardness (LC) of the sheet can be measured using a texture measurement system KES-FB3-AUTO-A (trade name, manufactured by Kato Tech Co., Ltd.). The measurement settings are: sensitivity 2, compression speed 50 seconds / mm, data capture sensation 0.1 seconds, pressurization area 2 cm ² (attached jig), and the size of the sheet to be measured is 15 cm × 15 cm And placed in the center of the measuring table. Three points are measured according to the standard setting of the measuring instrument, and the average value is obtained as the measured value.

Further, cushioning properties and deformability of the seat 10 will be described below with reference to FIGS.
FIG. 9 is an explanatory diagram schematically showing the relationship between the first protrusion and the second protrusion in plan view. A model in which the first protrusion 1 and the second protrusion are arranged extending in the first direction (x) and the second direction (y) in the plane is shown (the x direction and the y direction are one point) Including the direction illustrated by the chain line and the direction in which it is translated). Each of the first protrusion 1 and the second protrusion 2 (broken line) indicated by a circle indicates a schematic position in plan view, and its center substantially coincides with the apex of the top. FIG. 10 is a schematic view of the deformed state of the nonwoven fabric when the contact plane is viewed as a hard member (for example, a metal base and a pressing plate) as described above, or actually pressed using a predetermined pressure. It is explanatory drawing shown in. The field of view is similar to the cross section shown in FIG. 2, but is simplified.
The sheet 10 maintains the internal spaces 18 and 28 between the pressing surface and the sheet even when the nonwoven fabric is pressed in the surface direction with a pressure of 50 gf / cm ² by the non-deformable pressing surface. It is preferable. Such maintainability of the internal space may be only on the first surface side or the second surface side. This means that even when subjected to a corresponding pressure, the nonwoven fabric rebounds moderately and the nonwoven fabric exhibits good cushioning properties. The pressure of 50 gf / cm ^{2 is} a pressure corresponding to the pressure when the infant is seated when applied to an actual absorbent article, for example. In the present invention, the measurement of pressure was performed according to the procedure described in the examples described below unless otherwise specified.

Further, when the non-deformable pressing surface presses the nonwoven fabric in the surface direction with a pressure of 0.5 gf / cm ² , the sheet 10 has a contact area S _0.5 between the pressing surface and the nonwoven fabric and the pressing surface. The ratio (S _0.5 / Sa) to the unit total area Sa (see FIG. 9) (excluding the space when there is a space of 1 mm ² or more in the surface direction) is 0.1 to 0.4, and further 0 .12 to 0.35, and particularly preferably 0.15 to 0.3. That the contact area S _0.5 is smaller than the unit total area with respect to the pressure in such a range means that the internal spaces 18 and 28 are maintained even under the pressure as shown in FIG. It means having excellent touch feeling such as softness or smoothness when touching the nonwoven fabric. The pressure of 0.5 gf / cm ^{2 is} a pressure corresponding to a contact state between the seat and the skin when not sitting, for example, when applied to an actual absorbent article.

Note that the contact area ratio as described above is preferably on both the first surface side and the second surface side, but may be only on one side. With little supplementary relationship between the contact area S _0.5 with the unit total area Sa, a unit total area Sa as shown in FIG. 9 may be any region in a plan view in the nonwoven fabric, preferably, the This is a region in which a plurality of the first protrusions 1 and the second protrusions 2 are evenly included. In contrast, when viewed as a contact portion between the circle of the first pressing surface of the projecting portion 1 by a solid line in the drawing, the contact area S _0.5 of the first projecting portion in the unit total area Sa was hatching This is the total area of each region. This ratio is the contact area ratio (S _0.5 / Sa).

In the present embodiment, when the sheet 10 is pressed in the surface direction with a pressure of 50 gf / cm ² by the non-deformable pressing surface, the pressing surface and the contact area S _{50 of the} sheet 10 and the unit of the pressing surface. The ratio (S ₅₀ / Sa) to the total area Sa is preferably 0.3 to 0.9, more preferably 0.4 to 0.85, and particularly preferably 0.5 to 0.8.
In this range, the contact area S ₅₀ is smaller than the unit total area with respect to the pressing (see FIG. 10C), and there is a space as a non-woven fabric structure even during pressing such as when sitting. This means that absorbency and breathability are maintained. Note that the contact area ratio as described above is preferably on both the first surface side and the second surface side, but may be only on one side. The contact area ratio (S ₅₀ / Sa) is viewed in the same manner as the contact area ratio (S _0.5 / Sa) except that the front and back sides are different.

Furthermore, in the sheet 10, the sheet thickness T _0.5 when pressed by a non-deformable pressing surface with a pressure of 0.5 gf / cm ² is preferably 2.5 to 5, and more preferably 2.8. Preferably, it is ˜4.5. Further, the sheet thickness T ₅₀ when pressed at a pressure of ₅₀ gf / cm ² with a non-deformable pressing surface is preferably 0.5 to 1.3, more preferably 0.7 to 1.1. It is preferable.
In addition the sheet 10 is non-deformability of the sheet thickness _{T 0.5} when pressed with a pressure of 0.5 gf / cm ² by the pressing surface, nondeformable the nonwoven fabric at a pressure of 50 gf / cm ² by the pressing surface of the The ratio with respect to the sheet thickness T ₅₀ (T _0.5 / T ₅₀ ) when pressing in the surface direction is preferably 2.5 to 10, and more preferably 2.5 to 8. By using such a nonwoven fabric having a stiffness in the sheet thickness direction, it has excellent cushioning properties, and contributes to absorption performance such as dropping liquid quickly and reducing liquid return.

(Measurement method of thickness)
The thicknesses T _0.5 and T ₅₀ of the sheet 10 can be measured using the texture measurement system KES-FB3-AUTO-A. The measurement settings are: sensitivity 2, compression speed 50 seconds / mm, data capture sensation 0.1 seconds, pressurization area 2 cm ² (attached jig), and the size of the sheet to be measured is 15 cm × 15 cm Measure in the center of the measuring table. According to the standard setting of the measuring device, the measurement is performed at three locations, the thickness at a load of 0.5 g / cm ² is T _0.5 , the thickness at a load of 50 g / cm ² is T _50, and the average value at each of the three locations is a measured value. It was.

When the constricted part 7 of the seat 10 is in a part of the circumferential direction of the surface of the wall part 3, the constricted part 7 is formed from the second projecting part 2 from the viewpoint of providing cushioning and deformability of the sheet 10 as described above. The wall 3 is preferably formed where stress is likely to concentrate.
For example, when a sheet material is conveyed in the machine direction (MD direction) in order to shape the sheet, the sheet material is easily stretched in the MD direction, and the strength of the member is likely to decrease in the CD direction. Therefore, in the shaped sheet, stress tends to concentrate on the portion of the second protrusion 2 that matches the CD direction at the time of manufacture. It is preferable that the constricted portion 7 is formed in pairs at least at this portion. In particular, when the sheet 10 is made of a nonwoven fabric, the constricted portion 7 is preferably in the CD direction because the fiber web before shaping at the time of manufacture and conveyance tends to have the fibers oriented in the MD direction. “MD” refers to the direction in which the sheet material flows during manufacture, and is an abbreviation for “Machine Direction”. Also called flow direction. “CD” is a direction orthogonal to the MD in the sheet in-plane direction, and is an abbreviation of “Cross Direction”.

From the same viewpoint, if the planar shape of the internal space 28 of the second protrusion 2 is an annular shape having a major axis and a minor axis, stress tends to concentrate in the minor axis direction. Therefore, it is preferable that the constricted portions 7 are formed at least in pairs in the minor axis direction of the second projecting portion 2. For example, a form as shown in FIG. FIG. 11 is an explanatory view schematically showing a second protrusion having an elliptical planar shape with a major axis and a minor axis, (a) is a plan view, (b) is a front view, and (c) ) Is a cross-sectional side view. As shown in FIG. 11, when the planar shape is an elliptical shape having a major axis m and a minor axis n, the constricted portions 7 and 7 are formed in the minor axis n direction of the wall 3 of the second projecting portion 2. Is preferred.

Next, a material for forming the sheet 10 having the above shape and characteristics will be described.
As the material for forming the sheet 10, various sheet materials used for this type of article can be used as long as the above-described shape can be obtained. For example, a nonwoven fabric, a film, a woven fabric, paper, etc. are mentioned. Further, a composite sheet in which a plurality of these same or different materials are combined may be used.
When the sheet 10 is applied to an absorbent article, it is preferable to appropriately select materials and properties in accordance with the function of the member. For example, in the case of a surface sheet or intermediate sheet on the skin contact surface side of a liquid-retaining absorbent body or a covering sheet of an absorbent core, a liquid-permeable sheet is preferred. In the case where the sheet is disposed on the non-skin contact surface side with respect to the absorbent body, the sheet is preferably a moisture-permeable or leak-proof sheet. Moreover, when it is set as the side sheet | seat for preventing the side leakage of a liquid, it is preferable that it is a water-repellent sheet | seat.

When the sheet 10 is applied to an absorbent article as a liquid-permeable member such as a top sheet, it is preferable to arrange the first surface side of the sheet 10 on the skin contact surface side. That is, the 2nd protrusion part 2 with the narrow part 7 becomes a non-skin contact surface side. Thereby, the collection property of the excrement of the sheet | seat 10 by the narrow part 7, and the below-mentioned liquid permeability, liquid diffusibility, liquid return prevention property, and absorption performance can be exhibited.

As the nonwoven fabric, air-through nonwoven fabric, spunbond nonwoven fabric, spunlace nonwoven fabric, melt blown nonwoven fabric and the like can be used. The material is not particularly limited, and examples thereof include the following fibers. 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, such as A core-sheath structure fiber in which the sheath component is polyethylene or low-melting-point polypropylene is preferable, and typical examples of the core / sheath structure fiber include PET (core) / PE (sheath), PP (core) / PE ( Sheath), fibers having a core-sheath structure such as PP (core) / low melting point PP (sheath). 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 / polyethylene, and the composite composition of the polypropylene composite fiber is preferably polyethylene terephthalate / low melting point polypropylene, and more specifically, PET (core). / PE (sheath), PET (core) / 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.
When using the sheet | seat which consists of a nonwoven fabric as a surface sheet of an absorbent article, a hydrophilic nonwoven fabric or the nonwoven fabric by which the hydrophilic treatment was carried out is preferable. Moreover, when using as a side sheet, a water-repellent nonwoven fabric is preferable. When used as a sheet such as a back sheet on the non-skin contact surface side of the absorbent body, it is preferable to combine a non-woven fabric with a film (moisture permeable / non-moisture permeable) from the viewpoint of leakage prevention.

As a film, the thing using synthetic resins, such as polyethylene and a polypropylene, is mentioned, for example. Moreover, it is good also as a sheet | seat bonded together with the said nonwoven fabric.
When using a sheet made of a film as a back sheet of an absorbent article, etc., from the viewpoint of both leakage prevention and moisture permeability, for example, a hydrophobic thermoplastic resin, a minute inorganic filler made of calcium carbonate or the like, or compatibility A porous film obtained by melt-kneading an organic polymer or the like without a film to form a film and stretching the film uniaxially or biaxially is preferable. Moreover, when using for a surface sheet etc., a hydrophilic microporous film etc. are preferable from a liquid-permeable viewpoint. Moreover, when using a film for a surface sheet, a side sheet, etc., since it touches skin directly, it is preferable that the embossing which has a cloth-like touch is given from the viewpoint of the touch.

When the sheet 10 is made into a liquid-permeable sheet such as a surface sheet using the above-described forming material, and the sheet 10 is applied to an absorbent article, the following effects are further obtained in combination with the above-described shape. .
(Absorption performance (liquid permeability, liquid diffusibility, liquid return prevention, etc.))
The sheet 10 also has an internal space 18 corresponding to the first protrusion 1 on the second surface side. When the sheet 10 is used as a surface sheet or the like of the absorbent article and the first surface side is disposed on the skin contact surface, the internal space 18 of the first projecting portion 1 is disposed between the lower member such as the absorbent body. In this case, the excrement may be temporarily stored in the internal space 28 of the second projecting portion 2, or may be transmitted to the second surface side through the top portion 11 and the wall portion 3, and the interior of the first projecting portion 1. Some are collected in the space 18. That is, the sheet 10 is excellent in liquid permeability because it allows the liquid to permeate to the non-skin surface side while keeping it away from the skin and can temporarily store a large amount of liquid at that position.
Further, the constricted portion 7 included in the second projecting portion 2 retains the internal space by its spring property as described above and becomes like an inner lid of the internal space 28. By such an action of the constricted portion 7, the liquid return to the first surface side is suppressed, and the force to the lower layer works in the internal space 28 to facilitate the extrusion of the liquid to the second surface side. Thereby, the liquid is easily transmitted to the non-skin contact surface side of the sheet 10 and is easily diffused between lower-layer members such as the absorber. That is, the sheet 10 is excellent in liquid permeability, liquid diffusibility, and liquid return preventing property.

As described above, the seat 10 can suppress liquid return from the internal space to the skin surface side by holding the internal space due to the above-described cushioning property, the spring property of the constricted portion 7, and the like. Further, the constricted portion 7 acts to push the liquid toward the absorber, and the absorption speed from the top sheet to the absorber can be maintained fast. Further, when the sheet 10 is a top sheet, the pressure applied to the lower absorbent body is appropriately dispersed and the shape restoring force is large, so that the liquid return amount from the absorbent body is reduced. In addition, when the liquid overflows from the absorbent body in the case of an overabsorbing state, the liquid is appropriately diffused by the internal space 18 to other absorption sites that still have room for absorption. Therefore, the sheet 10 has high absorption performance stability.

Next, the case where the sheet 10 is made of a nonwoven fabric will be described in detail below. Nonwoven fabrics are preferred from the viewpoint of enhancing absorption performance such as liquid permeability and withstanding repeated pressing to maintain cushioning and deformability. In particular, although details will be described later, the wall portion 3 of the sheet 10 preferably has the orientation of the nonwoven fabric fibers oriented in the direction in which the wall stands up. A firm stiffness is born in the fiber portion thus oriented, and an appropriate cushioning property is realized without the fiber being crushed in the thickness direction. Furthermore, even if the nonwoven fabric is crushed by receiving the pressing force due to the fiber orientation of the wall portion 3 described above, the shape restoring force is large, and even if the packing state and wearing are continued, the initial cushioning property is not easily lost. Moreover, in the constricted part 7 of the wall part 3, since there exists the clearance gap between the fibers of a nonwoven fabric, it is easy to move more flexibly and stress is relieve | moderated and a spring property is easy to be exhibited more effectively.

More detailed features of the sheet 10 made of a nonwoven fabric including the above fiber orientation will be described with reference to FIGS. 12 to 14 in which the shape is simplified as a model. Hereinafter, what consists of a nonwoven fabric is demonstrated as the nonwoven fabric sheet 10. FIG. The nonwoven fabric sheet 10 has a first protruding portion 1 (shown by an execution line) and a second protruding portion 2 (shown by a broken line), which are shown as simple circles in FIG. The sizes of these circles are slightly different for distinction, and do not coincide with the form shown in FIG. In the nonwoven fabric sheet 10, the 1st protrusion part 1 and the 2nd protrusion part 2 are arrange | positioned by the grid | lattice-like arrangement | sequence. In other words, when the first row k ₁ , the second row k ₂ , and the third row k ₃ are viewed in a predetermined direction, the first protrusion 1 and the second protrusion 2 in each row Are alternately arranged, and when the protrusions of each row are projected in a direction (y direction) oblique to each row within the sheet surface, the first protrusions and the second protrusions are adjacent in the adjacent rows. Overlapping relationship. More specifically, the first protrusion 1 and the second protrusion 2 overlap each other in the n-th row and the (n + 2) -th row. That is, in the present embodiment, when the first protrusion and the second protrusion of the column k ₁ is moved parallel to the y-direction, there is a superimposed relation to the first protrusions and second protrusions of the row k ₃ . However, the present invention is not construed as being limited to this, and there may be a shift between the adjacent first protrusion and second protrusion.

Between the 1st protrusion part 1 and the 2nd protrusion part 2, the wall part 3 is formed as these shared parts. When viewed from the central first protrusion 1 shown in FIG. 12, four wall portions 31, 32, 33, and 34 that are continuous from the four second protrusions 2 are formed. The four wall portions 31 to 34 are connected by wall portions 31 ′, 32 ′, 33 ′, and 34 ′ in the in-plane direction of the sheet to form an annular wall portion 3 in series. . There is a ridge portion which is the back of the horse between the first protrusions adjacent on the first surface side of the wall portions 31 ′, 32 ′, 33 ′, 34 ′, and that portion becomes the ridge portion 6. Corresponding to each of the wall portions 31 ′ to 34 ′, ridge portions 61 to 64 are formed.

13 (a) is an illustration a rectangular model expand wall 3 shown in FIG. 12, line g ₁ illustrated therein represents the orientation direction of the fibers. In order to represent the position of the wall portion, the reference numerals 31 to 34 are added as positions that differ every 90 ° when viewed in a cross section cut along a plane orthogonal to the mother ship, with the annular wall portion as a cylinder. As shown. As shown to Fig.13 (a), the wall part 3 of this embodiment is orientated in the standing direction of the wall part in any location. In the present embodiment, the 0 ° position (wall portion 31) and the 180 ° position (wall portion 33) are biased toward the second surface side (z ₂ ) and have a strong orientation (line g _1b). ), And the 90 ° position (wall portion 32) and the 270 ° position (wall portion 34) are strongly oriented in a state of being biased to the first surface side (z ₁ ) side. A portion indicating (line g _1a ) is located. Although not shown in the figure because the figures are crowded, the same applies to the wall portions 31 ′ to 34 ′, and the same fiber orientation is obtained over the entire surface. However, the wall portion showing a strong orientation constitutes an orientation structure of an annular wall portion that gradually changes as a whole at the intermediate positions changing as 31, 32, 33, and 34. As described above, this produces a cushioning characteristic peculiar to the present embodiment.
On the other hand, for example, when a conventional nonwoven fabric that has been fused and given a predetermined orientation before being shaped is given a depression by embossing or the like, an annular wall is usually used as shown in FIG. When the portion is divided every 90 ° in plan view, the fiber orientation changes at each division position. Specifically, the fibers are oriented in the standing direction (line g _1c ) in the wall portions 31 and 33 as shown in the figure, whereas the fibers are oriented in the direction (line g ₂ ) perpendicular to the wall portions 32 and 34. Are oriented.

FIG. 14 schematically shows the fiber orientation direction (line g ₃ ) in a state where one second protruding portion 2 shown in FIG. 12 is taken out. In order to specify the position, the code | symbol of a wall part is attached | subjected to the corresponding position. As shown in the figure, in this embodiment, the fiber has a radial fiber orientation that converges toward the top 21 of the second protrusion 2. In other words, when the relationship with the wall portion is mentioned together, the fibers are converged from the wall portion 3 to the second protrusion portion 2 so as to converge toward the top portion 21 of the second protrusion portion along the surface direction of the sheet surface. Is oriented. Thus, there exists an effect | action of uniformity of an external appearance, shape retainability, high absorption performance, etc. by having the fiber orientation in radiation | emission in the 2nd protrusion part top part 21. FIG.

The method for manufacturing the nonwoven fabric sheet 10 may be a method generally used for this type of product as appropriate. If an example is given, the following aspects will be mentioned. The fiber web before being fused is supplied from the card machine to the web shaping device so as to have a predetermined thickness. In the web shaping apparatus, first, air at normal temperature (about 23 ° C.) is supplied, and the fiber web is fixed on a pedestal (not shown) having a large number of protrusions 9 (see FIG. 2) and air permeability. Let Next, hot air h (see FIG. 2) is blown onto the fiber web on the pedestal at a temperature at which each fiber can be appropriately fused, and the fiber web is shaped along the protrusions 9 on the pedestal. The fibers are fused. The temperature of the hot air at this time is preferably 130 to 160 ° C. and the wind speed is preferably 20 to 80 m / s in consideration of a general fiber material used for this type of product.

Furthermore, as an example of a method for forming the constricted portion 7 on the nonwoven fabric sheet 10 described above, pressing with a nip roll can be cited. It is preferable to press at a linear pressure of 20 to 50 kg / cm according to the state of the above-mentioned non-woven fabric.

Considering continuous production, there is a mode in which the pedestal is transportable and the typed nonwoven fabric that is being conveyed is wound up by a roll. The formation of the constriction may be performed immediately after the shaping process, or the constriction process may be performed when the shaped non-woven fabric is once wound on a roll and processed into an article such as a diaper or a sanitary product. You may go.

The dimensions of the sheet 10 according to this embodiment will be described below.
Regarding the thickness of the sheet, the thickness of the sheet 10 as a whole is referred to as the sheet thickness (T), and the local thickness of the sheet curved in the unevenness is distinguished as the layer thickness (S) (FIG. 2). reference). The sheet thickness (T) may be appropriately adjusted depending on the use, but considering use as a surface sheet for diapers, sanitary products, etc., 1.0 mm to 4.5 mm is preferable, and 1.5 mm to 4.2 mm is more preferable. . By setting it as the range, it is possible to achieve both a good appearance with an appropriate stereoscopic effect and an excellent absorption performance. The layer thickness may be different at each site in the sheet, and may be appropriately adjusted depending on the application. In consideration of use as a surface sheet for diapers, sanitary products, etc., the layer thickness (S ₁ ) at the top of the first protrusion is preferably 0.1 mm to 1 mm, and more preferably 0.2 mm to 0.8 mm. The preferred layer thickness ranges are the same for the layer thickness (S ₂ ) at the top of the second protrusion and the layer thickness (S ₃ ) at the wall.
In the nonwoven fabric 10 of the present embodiment, the layer thickness S ₁ of the first projecting portion _1, the layer thickness S ₃ of layer thickness S _2, and the wall portion of the second projecting portion are substantially the same. Here, “substantially the same” means that the thickness is substantially the same when each cross section is observed. By setting it as the nonwoven fabric of such a form, the uniformity of an external appearance and the stable absorption performance and cushioning property can be obtained, and it is preferable.

It is preferable that the thickness of the sheet 10 does not substantially change between when it is dried and when it is wet. That is, it is preferably 85 to 115%, more preferably 90 to 110%, in the following thickness change rate.
Thickness change rate (%)
= Wet thickness (mm) / Dry thickness (mm) x 100 (Equation 1)
-Thickness at the time of drying The thickness of the sheet after standing for 24 hours in a normal temperature (23 ° C, 50% RH) environment.
-Thickness when wet The sheet is allowed to stand in a normal temperature (23 ° C., 50% RH) environment for 24 hours. Ion exchange water is put into a flat container larger than the sheet until the height becomes 10 mm. The sheet is put into this container and taken out after 1 hour. The thickness of this sheet.

The distance between the rows formed by the first protrusions 1 and the second protrusions 2 may be appropriately adjusted depending on the application, but is preferably 1 mm to 12 mm in consideration of use as a surface sheet for diapers, sanitary products, and the like. 5 mm to 6 mm is more preferable.

Next, an application example of the sheet 10 to the absorbent article will be described with reference to FIG.
FIG. 15 is a perspective view schematically showing a disposable diaper 100 to which the sheet 10 is applied with a part cut away. The diaper shown in the figure is a tape-type disposable diaper for infants, and is shown in a state where a diaper developed in a plane is bent slightly and viewed from the inside (skin contact surface side).

The disposable diaper 100 of the present embodiment includes a liquid-permeable top sheet 10 disposed on the skin contact surface side, a liquid-impermeable back sheet 81 disposed on the non-skin contact surface side, and a space therebetween. (See FIG. 15). The sheet 10 of the above embodiment is applied as the top sheet, and the first protruding surface side is a skin contact surface. In the present embodiment, an absorber 83 is interposed between the back sheet 81 and the top sheet 10. The back sheet 81 is in the unfolded state, and has a substantially hourglass shape in which both side edges are confined inward in the longitudinal center c, and the back sheet 81 is composed of a plurality of sheets even if it is composed of one sheet. It may be a thing. In the present embodiment, a side leakage preventing gather 82 formed by the side seat 85 is provided, and thereby side leakage of liquid or the like in the hip joint part due to an infant's exercise or the like can be effectively prevented. In the diaper of this embodiment, a functional structure part, a sheet material, etc. may be provided. In addition, in FIG. 15, the arrangement | positioning relationship and boundary of each member are not illustrated strictly, and if it is set as the general form of this kind of diaper, the structure will not be specifically limited.

The diaper 100 of this embodiment is shown as a tape type, and a fastening tape 86 is provided on the flap portion on the back side r. The diaper can be mounted and fixed by applying the tape 86 to a tape applying part (not shown) provided on the flap part on the ventral side f. At this time, the center part c of the diaper is gently bent inward, and the absorbent body 83 is worn so as to run along the baby's buttocks and lower abdomen. As a result, excreta is absorbed and held in the absorber 83 accurately. By using it in such a form, especially the sheet | seat 10 is applied as a surface sheet, and the favorable touch, cushioning property, and excretion collection property are shown. In particular, in the diaper 100, the excrement collecting ability can achieve extremely high performance that cannot be achieved with a conventional surface sheet of linear protrusions or with a small hole, for example, the skin of an infant. It can be suitably protected from rough skin caused by diarrhea or soft stool.
Furthermore, the diaper 100 can suppress liquid return from the internal space to the skin surface side by holding the internal space due to the cushioning property of the seat 10, the spring property of the constricted portion 7, and the like. Further, the constricted portion 7 acts to push the liquid toward the absorber, and the absorption speed from the top sheet to the absorber can be maintained fast. In addition, since the sheet 10 moderately disperses the pressure applied to the lower-layer absorber and has a large shape restoring force, the amount of liquid return from the absorber to the top sheet is reduced. In addition, even if the excretion-corresponding region of the absorbent body is in an overabsorbed state, the liquid is appropriately diffused by the internal space 18 to other absorption sites that still have room for absorption. Therefore, the diaper 100 is excellent in liquid permeability and high stability in absorption performance by suppressing liquid remaining and liquid return on the skin contact surface side of the top sheet.

The sheet of the present invention is excellent in cushioning properties and deformability, and has good air permeability. Moreover, the absorbent article of this invention becomes the thing excellent in the collection property of excrement using the said sheet | seat.

The sheet of the present invention can be used for various other purposes. For example, it can be suitably used as a surface sheet for absorbent articles such as the disposable diapers described above, sanitary napkins, panty liners, urine absorption pads and the like. Above all, because it is excellent in air permeability and liquid diffusibility due to the network structure on both sides of the sheet, deformation characteristics under pressure, etc., the surface sheet such as diapers and sanitary products and absorbents It can also be used as a sublayer interposed therebetween. In addition, the form utilized as a surface sheet, a gather, an exterior sheet, and a wing is also mentioned. In addition, the form used as a wiping wipe sheet, a cleaning sheet, and a filter is also mentioned.

This invention discloses the following sheets and absorbent articles further regarding embodiment mentioned above.
<1> A first projecting portion projecting to the first surface side of the sheet in plan view and having an internal space, and a second surface side opposite to the first surface side, and the internal space The first protrusion and the second protrusion are alternately spread in the plane direction of the sheet through the wall alternately in each of the different directions intersecting in plan view of the sheet. The internal space of the first protrusion is open to the second surface side, the internal space of the second protrusion is open to the first surface side, and the second protrusion protrudes from the top of the first protrusion. A sheet having a portion constricted toward the internal space of the second protrusion on the wall connected to the top of the part.

<2> The internal space held by the first protrusion and the second protrusion is in the shape of a truncated cone or hemisphere having a round top at the top similar to the outer diameter of each of the first protrusion and the second protrusion. The sheet according to <1>.
<3> The sheet according to <1> or <2>, wherein the constricted portion is formed in pairs at least at two places.
<4> In any one of the above items <1> to <3>, in the cross section in the thickness direction of the second protrusion, the constricted portion is narrower than the width of the second protrusion. Sheet.
<5> In the cross section in the thickness direction of the second projecting portion, the width B is the distance between the inner walls at a position where the pair of constricted portions are closest to each other, and the width A is the width between the wall portions near and below the constricted portions. Is the distance between the inner walls of the widest portion, the ratio B / A of the width B to the width A is 0.2 to 0.9, according to any one of the above items <1> to <4> Sheet.
<6> The constricted portion may be any one of the above items <1> to <5>, which is disposed at a boundary between the region p ′ ₂ and the region p ′ ₃ where the curvature of the top portion of the second projecting portion changes. The described sheet.
<7> A ratio T ₇ / T of a height T ₇ from the top of the second protruding portion of the constricted portion to a thickness T of the sheet is 0.1 to 0.9. The sheet according to any one of 6>.
<8> The sheet according to any one of <1> to <7>, wherein the constricted portions are formed in pairs at least at two locations and are formed in a streak shape with a predetermined width.
<9> When the semicircular circumferential length of the outer periphery of the second projecting portion at the height position where the constricted portion is arranged is C and the circumferential length of the constricted muscle of the constricted portion is D, these ratios The sheet according to any one of <1> to <8>, wherein D / C is 0.2 to 0.9.
<10> The sheet according to any one of <1> to <9>, wherein the constricted portion is present around the entire circumference of the second projecting portion.
<11> The sheet according to any one of <1> to <10>, wherein the constricted portion has a rounded shape with few corners.
<12> The sheet according to any one of <1> to <11>, wherein the constricted portion of the sheet material is folded to form a laminated thickness portion by pressing in the sheet thickness direction.
<13> The sheet according to any one of <1> to <12>, wherein the compression hardness LC of the sheet is 0.01 to 0.35.
<14> When the sheet is pressed in the surface direction with a pressure of 50 gf / cm ² by a non-deformable pressing surface, the contact area S ₅₀ of the pressing surface and the sheet and the unit total area Sa of the pressing surface The sheet according to any one of <1> to <13>, wherein the ratio S ₅₀ / Sa is 0.3 to 0.9.
<15> the sheet thickness _{T 0.5} when pressurized to surface in the thickness direction of the sheet at a pressure of 0.5 gf / cm ^2, the thickness direction of the sheet at a pressure of 50 gf / cm ² in surface The sheet according to any one of <1> to <14>, wherein a ratio T _0.5 / T ₅₀ to the sheet thickness T ₅₀ when pressed is 2.5 to 10.0.
<16> The sheet according to any one of <1> to <15>, wherein the constricted portion is formed in a place where stress is likely to concentrate on the wall portion of the second projecting portion.
<17> The sheet according to any one of <1> to <16>, wherein the constricted portion is present in a direction orthogonal to a machine direction at the time of manufacture.
<18> The internal space of the second projecting portion has an annular shape having a major axis and a minor axis in plan view, and the constricted portion is disposed in the minor axis direction. The sheet according to any one of the above.
<19> The sheet according to any one of <1> to <18>, wherein the sheet is a nonwoven fabric.
<20> The sheet according to <19>, wherein the wall portion has a fiber orientation along a direction connecting the first projecting portion and the second projecting portion at any location in the planar direction of the sheet. .
<21> An absorbent article in which the sheet according to any one of <1> to <20> is applied as a surface material with the second surface side facing the non-skin contact surface side.
<22> A disposable diaper in which the sheet according to any one of <1> to <20> is applied as a surface material with the second surface side facing the non-skin contact surface side.
<23> A fiber web containing thermoplastic fibers is transported onto a pedestal having a large number of protrusions and air permeability, and hot air is blown from the top of the fiber web toward the pedestal to form an uneven shape on the web. A method for producing a nonwoven fabric comprising:
Blowing the hot air to shape the fiber web along the protrusions on the pedestal;
Then, the step of switching to a temperature higher than the hot air temperature and fusing each fiber,
Furthermore, the manufacturing method of the nonwoven fabric which has the process of giving the press process by a nip roll.
<24> The method for producing a nonwoven fabric according to <23>, wherein the nip roll is pressed under a condition of a linear pressure of 20 to 50 kg / cm.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not construed as being limited by these examples.

Example 1
A 2.2-dtex × 51 mm core-sheath composite fiber having a core of polyethylene terephthalate and a sheath of polyethylene was supplied from the card machine to the web shaping device so as to have a basis weight of 30 g / m ² . In the web shaping device, normal temperature air was supplied to fix the fibrous web on a pedestal having a large number of protrusions and air permeability. The pitch of the protrusions on this pedestal (the distance between the centers in the plan view of the protrusions) was 8 mm in the MD direction, 5 mm in the CD direction, and the protrusion height was 3 mm. Next, hot air (temperature 130 ° C., wind speed 50 m / s) is blown onto the fiber web on the pedestal, and the fiber web is shaped along the protrusions on the pedestal. The core-sheath structure fibers were fused by switching to a wind speed of 5 m / s. The line speed at this time was 100 m / min. Next, it passed between nip rolls adjusted to a linear pressure of 35 kg / cm. In this way, the non-woven fabric that was heat-sealed and shaped and pressed was taken out, and a sheet test body 1 having a constricted portion was obtained.

(Example 2)
A sheet test body 2 was obtained in the same manner except that the protrusion height of the protrusion on the base in Example 1 was set to 5 mm.

(Comparative Example 1)
A nonwoven fabric having a bellows-like shape was produced in the same manner as in Example 1 of JP-A-2008-25081. Specifically, it is as follows.
As the first fiber layer, low-density polyethylene (melting point 110 ° C.) and polyethylene terephthalate core-sheath structure, average fineness 3.3 dtex, average fiber length 51 mm, fiber A coated with a hydrophilic oil agent, and high-density polyethylene (melting point 135 ° C) and a core-sheath structure of polyethylene terephthalate, and a fiber layer in which an average fineness of 3.3 dtex, an average fiber length of 51 mm, and a fiber B coated with a water-repellent oil agent was used. Fiber A and Fiber B were contained at a mixing ratio of 70:30, and the basis weight was adjusted to 15 g / m ² .
As the second fiber layer, a fiber layer having a core-sheath structure of high-density polyethylene and polyethylene terephthalate, an average fineness of 4.4 dtex, an average fiber length of 38 mm, and a fiber coated with a hydrophilic oil agent was used. The basis weight in this fiber layer was 25 g / m ² .
The apparatus similar to that shown in FIG. 8 and FIG. 9 of Japanese Patent Application Laid-Open No. 2008-25081 is used, while conveying the laminated fibers as described above, a temperature of 105 ° C. from the blowing part of the apparatus, A sheet test body c1 having a bellows-like shape was obtained by blowing hot air under conditions of an air volume of 1200 l / min.

(Comparative Example 2)
In the same manner as in Example 1 of Japanese Patent Application Laid-Open No. 2001-20168, a nonwoven fabric having irregularities was produced by embossing. Specifically, it is as follows.
By forming a spunbonded nonwoven fabric made of polypropylene resin with a basis weight of 40 g / m ² at 130 ° C. using two convex rolls on both sides at 130 ° C., a large number of regularly arranged convex portions [convex portions 5 / cm ² (area standard of compression recoverable sheet), distance between each convex part; 4.5 mm, thickness between the front surface and the back surface of the convex part; 0.5 mm] is formed A compression recoverable sheet (sheet test body c2) comprising a fiber assembly was obtained.

(Comparative Example 3)
A nonwoven fabric having a two-layer structure having irregularities was produced in the same manner as in Example 1 of JP-A No. 2004-174234. Specifically, it is as follows.
As nonwoven fabrics constituting the first and second sheets, air through nonwoven fabrics each having a basis weight of 18 g / m ² and comprising 2.2 dtex core-sheath type composite fibers having a core of polyethylene terephthalate and a sheath of polyethylene are prepared. did. Using these sheets, an absorbent article sheet (sheet specimen c3) for disposable diapers was produced using an apparatus disclosed in JP-A No. 2004-174234. The height h of the convex part in the obtained sheet was 1.4 mm, the width w of the convex part along the X direction was 4.0 mm, and the width k of the joint part (concave part) was 1.0 mm.

The following measurement test was performed using the above-mentioned nonwoven fabric test specimen. The results are shown in Table 1 below.

<50gf / cm ² pressurization space>
A 10 cm square acrylic plate was prepared. At this time, the weight placed on the acrylic plate was adjusted so that the load was 50 gf / cm ² . A sheet was placed on a flat desk, an acrylic plate and a weight were placed thereon, and it was observed whether or not there was a space on the desk and between the acrylic plate and the sheet.

<Thickness>
The thickness of the nonwoven fabric was measured using a texture measurement system KES-FB3-AUTO-A. The measurement settings are: sensitivity 2, compression speed 50 seconds / mm, data capture sensation 0.1 seconds, pressurization area 2 cm ² (attached jig), and the size of the sheet to be measured is 15 cm × 15 cm And placed in the center of the measuring table. Three measurements were taken according to the standard settings of the measuring instrument. The thickness at a load of 0.5 g / cm ² was defined as T0.5, the thickness at a load of 50 g / cm ² was defined as T50, and average values at three locations were measured values.

<Compression hardness (LC)>
The compression hardness (LC) of the nonwoven fabric was measured using a texture measurement system KES-FB3-AUTO-A. The measurement settings are: sensitivity 2, compression speed 50 seconds / mm, data capture sensation 0.1 seconds, pressurization area 2 cm ² (attached jig), and the size of the sheet to be measured is 15 cm × 15 cm And placed in the center of the measuring table. Measurements were made at three locations according to the standard settings of the measuring instrument, and the average value was taken as the measured value.

<Cushioning>
The feel when the sheet was pushed or returned by the evaluator's hand from above was evaluated. There were three evaluators, and the average score (rounded to the first decimal place) was used as the evaluation result for the sheet.
The evaluation of the measurement results was distinguished as follows in consideration of practical requirements.
3: A feeling of resilience like a spring is felt when pushing and returning.
2: When pressed and returned, there is a feeling of resilience like a spring, but it is weak. Or, it feels a spring-like rebound only when it is pushed or returned.
1: There is no feeling of resilience like a spring when pushing and returning.

<Easily deformable>
The feel when the sheet was folded was evaluated. There were three evaluators, and the average score (rounded to the first decimal place) was used as the evaluation result for the sheet.
The evaluation of the measurement results was distinguished as follows in consideration of practical requirements.
3: Feels soft when folded. It also bends naturally.
2: Feels somewhat stiff when folded. Alternatively, a bent line is generated when it is bent.
1: Feels hard when folded. Alternatively, a bent line is generated when it is bent.

<Absorption rate>
A non-woven fabric specimen cut out to 280 × 160 mm was formed into a sublayer (web having a basis weight of 1220 g / m ² having a core-sheath composite fiber of 4.43.3 dtex whose core is made of polyethylene terephthalate and whose sheath is made of polyethylene, and On the pulp absorbent body through an air-through non-woven fabric produced by superimposing a web having a basis weight of 20 g / m ² having a core-sheath composite fiber of 7.8 dtex having a core of polypropylene and a sheath of polyethylene. Installed. A load of 20 g / cm ² was evenly applied on the nonwoven fabric, and a cylinder with an inner diameter of 36 mm placed at the approximate center of the test specimen was applied, and physiological saline was injected therefrom. Thereafter, physiological saline was injected three times at a rate of 40 g every 10 minutes, and the time (seconds) to be absorbed when the third injection was performed was measured. The measurement results of each sample are shown in Table 1 below.
The evaluation of the measurement results was distinguished as follows in consideration of practical requirements.
A: Absorption time is within 180 seconds.
B: Absorption time is 180 to 300 seconds.
C: Absorption time is 300 seconds or more.

<Liquid returnability>
In the absorption rate evaluation, 10 minutes after the third injection, 20 filter papers (ADVANTEC Toyo 4A, size 100 mm × 100 mm) were placed on the injection part, and 3.5 kPa (3.5 kPa ( 3.5kg, size 100mm x 100mm). Remove the filter paper 2 minutes after placing the weight. The difference between the initial weight of the filter paper and the weight after pressurization is measured as the liquid return amount.
The evaluation of the measurement results was distinguished as follows in consideration of practical requirements.
A: The liquid return amount is 0.5 g or less.
B: Liquid return amount is 0.5 to 1 g.
C: Liquid return amount is 1 g or more.

From the above results, the non-woven fabrics (Examples) according to preferred embodiments of the present invention have better air permeability, higher cushioning and deformability, and faster absorption speed than the comparative examples. It can be seen that it is excellent in skin-friendly properties that do not stick.

While this invention has been described in conjunction with its embodiments, we do not intend to limit our invention in any detail of the description unless otherwise specified and are contrary to the spirit and scope of the invention as set forth in the appended claims. I think it should be interpreted widely.

This application claims priority based on Japanese Patent Application No. 2011-269380 filed in Japan on December 8, 2011, which is hereby incorporated herein by reference. Capture as part.

DESCRIPTION OF SYMBOLS 1 1st protrusion part 11 1st protrusion part top part 18 1st protrusion part Internal space 2 2nd protrusion part 21 2nd protrusion part top part 28 2nd protrusion part Internal space 3 Wall part 7 Constriction part 10 Sheet

Claims (24)

1. A first projecting portion projecting on the first surface side of the sheet in plan view and having an internal space, and a second projecting surface projecting on the second surface side opposite to the first surface side and having an internal space. Two projecting portions, and the first projecting portion and the second projecting portion are arranged to spread continuously in the sheet plane direction alternately through the wall portions in different directions intersecting in plan view of the sheet,
   The internal space of the first protrusion is open to the second surface side, the internal space of the second protrusion is open to the first surface side,
   The sheet | seat which has a part constricted toward the internal space of the said 2nd protrusion part in the said wall part connected from the top part of a said 1st protrusion part to the top part of a 2nd protrusion part.
2. The internal space held by the first protrusion and the second protrusion has a truncated cone shape or a hemispherical shape with rounded tops similar to the outer diameters of the first protrusion and the second protrusion, respectively. The sheet according to 1.
3. The sheet according to claim 1 or 2, wherein the constricted portions are formed in pairs at least at two places.
4. The sheet according to any one of claims 1 to 3, wherein the constricted portion is narrower than a width of the second projecting portion in a cross section in the thickness direction of the second projecting portion.
5. In the cross section in the thickness direction of the second projecting portion, the width B is the distance between the inner walls at the position where the pair of constricted portions are closest to each other, and the width A is the widest portion between the constricted portions and the lower portion. The sheet according to any one of claims 1 to 4, wherein a ratio B / A of the width B to the width A is 0.2 to 0.9 when the distance between the inner walls of the portions is used.
6. The constricted portion, the curvature of the top portion of the second projecting portion is changed, the sheet according to any one of claims 1 to 5 arranged on the boundary between the region p _'2 and region p' _3.
7. The ratio T ₇ / T of the height T ₇ of the constricted portion from the top of the second protrusion to the thickness T of the sheet is 0.1 to 0.9. The sheet according to item.
8. The sheet according to any one of claims 1 to 7, wherein the constricted portions are formed in pairs at least at two locations, and are formed in a streak shape with a predetermined width.
9. When the semicircular length of the outer periphery of the second projecting portion at the height position where the constricted portion is disposed is C and the peripheral length of the constricted muscle of the constricted portion is D, these ratios D / C The sheet according to any one of claims 1 to 8, wherein is from 0.2 to 0.9.
10. The sheet according to any one of claims 1 to 9, wherein the constricted portion is present all around the second projecting portion.
11. The sheet according to any one of claims 1 to 10, wherein the constricted portion has a rounded shape with few corners.
12. The sheet according to any one of claims 1 to 11, wherein the sheet material of the constricted portion is folded and becomes a laminated thickness portion by pressing in the sheet thickness direction.
13. The sheet according to any one of claims 1 to 12, wherein the compression hardness LC of the sheet is 0.01 to 0.35.
14. When the sheet is pressed in the surface direction with a pressure of 50 gf / cm ² by a non-deformable pressing surface, the ratio S ₅₀ between the pressing surface and the contact area S _{50 of the} sheet and the unit total area Sa of the pressing surface. The sheet according to any one of claims 1 to 13, wherein / Sa is 0.3 to 0.9.
15. A sheet thickness _{T 0.5} at which a pressure of 0.5 gf / cm ² pressurized to surface in the thickness direction of the sheet was pressurized in the thickness direction of the sheet at a pressure of 50 gf / cm ² in surface The sheet according to any one of claims 1 to 14, wherein a ratio T _0.5 / T ₅₀ with respect to the sheet thickness T ₅₀ is 2.5 to 10.0.
16. The sheet according to any one of claims 1 to 15, wherein the constricted portion is formed in a place where stress is likely to concentrate in the wall portion of the second projecting portion.
17. The sheet according to any one of claims 1 to 16, wherein the constricted portion is present in a direction orthogonal to a machine direction at the time of manufacture.
18. The internal space of the second projecting portion has an annular shape having a major axis and a minor axis in plan view, and the constricted portion is arranged in the minor axis direction. Sheet.
19. The sheet according to any one of claims 1 to 18, wherein the sheet is made of a nonwoven fabric.
20. The sheet according to claim 19, wherein the wall portion has a fiber orientation along a direction connecting the first projecting portion and the second projecting portion at any location in the planar direction of the sheet.
21. 21. An absorbent article in which the sheet according to claim 1 is applied as a surface material with the second surface side facing the non-skin contact surface side.
22. A disposable diaper in which the sheet according to any one of claims 1 to 20 is applied as a surface material with the second surface side facing the non-skin contact surface side.
23. A nonwoven fabric which conveys a fiber web containing thermoplastic fibers onto a pedestal having a large number of protrusions and has air permeability, and blows hot air from above the fiber web toward the pedestal to shape the uneven shape on the web. A manufacturing method comprising:
    Blowing the hot air to shape the fiber web along the protrusions on the pedestal;
    Then, the step of switching to a temperature higher than the hot air temperature and fusing each fiber,
    Furthermore, the manufacturing method of the nonwoven fabric which has the process of giving the press process by a nip roll.
24. The method for producing a nonwoven fabric according to claim 23, wherein the nip roll is pressed under a condition of a linear pressure of 20 to 50 kg / cm.

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