JP5047074B2 - Elastic sheet for absorbent articles - Google Patents

Description

  The present invention relates to an elastic sheet containing various functional materials.

  Various proposals have been made to use a sheet containing an elastomer material as a constituent material of an absorbent article. For example, the present applicant has previously proposed that a compression recoverable sheet made of a fiber assembly containing an elastomer component is disposed in an absorbent body containing an absorbent polymer (see Patent Document 1). According to this technique, the thickness of the absorbent article can be reduced in a state in which the absorbent article is stored in the package, and the thickness is recovered when the absorbent article is taken out from the package. However, this compression-recoverable sheet has elasticity (stretchability) in the thickness direction, but does not have stretchability in the plane direction, so that the stretchability is required in the plane direction. It is not suitable.

  As another technique for a sheet containing an elastomer material, a sheet is known in which discrete particles of a solid substance are contained in a meltblown nonwoven fabric containing microfibers made of an elastometric substance (see Patent Document 2). Although this sheet has stretchability in the plane direction, the elastometric material is exposed on the surface of the sheet, so that a sticky feeling peculiar to the elastometric material and blocking caused thereby occur.

JP 2001-20167 A JP 62-84143 A

  An object of the present invention is to provide a stretchable sheet that can eliminate the drawbacks of the prior art described above.

  The present invention provides a first stretchable non-stretchable sheet in which a plurality of elastic filaments or elastic strips arranged so as to extend in one direction without crossing each other are substantially non-stretched over their entire length. And a second stretchable non-stretchable sheet, between the first stretchable non-stretchable sheet and the second stretchable non-stretchable sheet Furthermore, the present invention provides an elastic sheet in which a functional material imparting a predetermined function is sandwiched between the elastic sheets.

  The stretchable sheet of the present invention sufficiently exhibits the functions of various functional materials while having good stretchability. In addition, the stretchable sheet of the present invention is free from problems such as blocking.

  The present invention will be described below based on preferred embodiments with reference to the drawings. FIG. 1 shows a partially broken perspective view of the first embodiment of the stretchable sheet of the present invention. The stretchable sheet 10 of the present embodiment includes a first stretchable non-stretchable sheet (hereinafter also referred to as “first stretchable sheet”) 11 and a second stretchable non-stretchable sheet (hereinafter “ It is also referred to as a “second extensible sheet”.) It is composed of a total of two sheets and a large number of elastic filaments 13 sandwiched between both sheets. Each elastic filament 13 is joined to the first and second extensible sheets 11 and 12. In the present invention, the term “elasticity” refers to the original length when the force is released from a state where it can be stretched and stretched 50% of the original length (which is 150% of the original length). The property of returning to a length of 113% or less.

  A functional material 30 is sandwiched between the sheet 11 and the sheet 12. The functional material 30 is substantially uniformly distributed over the plane direction of the stretchable sheet 10 or is arranged in a pattern (intermittent, strip-like). The functional material 30 is in a joined state with the sheet 11 and / or the sheet 12, or is not joined with the sheet 11 and the sheet 12. The fact that the functional material 30 is sandwiched means that the functional material 30 is at least positioned between the sheet 11 and the sheet 12 or is held in either the sheet 11 or the sheet 12.

  Both the sheet 11 and the sheet 12 are extensible. However, both the sheet 11 and the sheet 12 are non-stretchable. The sheet 11 and the sheet 12 can be extended in the same direction as the direction in which the elastic filament 13 extends. In the present application, the term “extendable” means that it can be stretched by a desired required external force (external force during stretching, external force due to human force on the use surface, etc.). For example, in the case of a non-woven fabric, stretchable is, for example, (a) when the constituent fiber itself of the non-woven fabric is stretched, and (b) even if the constituent fiber itself does not stretch, the fibers connected at the intersection are separated. Or when the three-dimensional structure formed by a plurality of fibers is structurally changed due to bonding of fibers, the constituent fibers are broken, the slack of the fibers is stretched, and the whole nonwoven fabric is stretched. Include. Taking film as an example, stretchable means (i) when the molecular chain of the constituent resin itself of the film is extended or shifted, and (b) when the constituent resin itself does not extend, the film Is partially broken (including slit opening, partial opening, particle-resin interfacial peeling, etc.), the slack of the film is stretched, or the whole film is stretched due to the deformation of the hole like an open film Including. Taking thin paper as an example, (b) when the constituent fibers themselves of the thin paper are stretched, and (b) even if the constituent fibers themselves are not stretched, the bound fibers are separated or the fibers are joined together. This includes a case where the three-dimensional structure formed by the fibers of the book is structurally changed, the constituent fibers are torn, or the slack of the fibers is stretched to stretch as a whole thin paper.

  The stretchable non-stretchable sheet is preferably highly stretchable. As a highly stretchable material, the stretchability of the stretchable non-stretchable sheet (including the stretchable sheet after stretching) is 30% at 100 cN / 50 mm strength. It is preferable to show the above. Furthermore, it is preferable to show 70% or more. When the maximum strength is 100 cN / 50 mm or less, the maximum elongation when the maximum strength is shown is preferably 30% or more. Elongation is based on the length before stretching. Similarly, in the stretchable sheet 10 using a highly stretchable sheet, the stretched sheet (including those stretched by post-processing) has an elongation of 200 cN / 50 mm strength. The degree is preferably 30% or more. When the maximum strength is 200 cN / 50 mm or less, the maximum elongation when the maximum strength is shown is preferably 30% or more. Elongation is based on free tension when no tension is applied. A stretchable sheet exhibiting the above-described characteristics can be regarded as a highly stretchable non-stretchable sheet. These are obtained in the same manner as the measurement of the maximum intensity described later.

  The maximum strength of the stretchable sheet that has been stretched in a highly stretchable stretchable sheet is preferably 5 cN / 50 mm or more, more preferably 100 cN / 50 mm or more, and even more preferably 500 cN / 50 mm or more. The maximum strength of the stretchable sheet 10 that has been stretched using a highly stretchable sheet is preferably 7 cN / 50 mm or more, more preferably 150 cN / 50 mm or more, and even more preferably 1000 cN / 50 mm or more.

  Further, in the present invention, non-stretchability means “when the force is released from a state where it can be stretched and stretched by 50% of the original length (which is 150% of the original length). In other words, it does not have the property of returning to a length of 113% or less of the original length.

  A further preferred embodiment of the present invention is that at least one of the extensible sheet sheets 11 and 12 is a highly extensible inelastic sheet. The reason for this is that, when stretched to the desired elongation, excessive breakage occurs, the strength is greatly reduced, and even if a sheet that cannot be used alone is used on one side, a highly stretchable sheet is used on the other. This is because the use of the stretchable sheet 10 provides excellent transportability during processing and durability on the product. In a more preferred embodiment of the present invention, a nonwoven fabric is used as the highly extensible sheet.

  The extensible sheets 11 and 12 may already be extensible in the state of the original fabric before being joined to the elastic filament 13. Alternatively, it is not stretchable in the state of the original fabric before being joined to the elastic filament 13, but is processed so as to be stretchable after being joined to the elastic filament 13, and becomes stretchable. Also good. Specific methods for making the extensible sheets 11 and 12 extensible (also referred to as “elastic development treatment” in the present specification) include heat treatment, inter-roll stretching, biting and stretching by tooth spaces and gears, Examples include tensile stretching with a tenter. In view of a preferable manufacturing method of the stretchable sheet 10 to be described later, the sheets 11 and 12 are improved in terms of transportability of the sheets 11 and 12 when the elastic filament 13 is fused to the extensible sheets 11 and 12. It is preferably not stretchable in the original fabric state. Moreover, generally speaking, the extensible sheets 11 and 12 do not have stretchability in both the original fabric state and the state after being joined to the elastic filament 13.

  Each elastic filament 13 is substantially continuous over the entire length of the stretchable sheet 10. The elastic filament 13 contains an elastic resin. The elastic filaments 13 are arranged so as to extend in one direction without crossing each other. However, the elastic filaments 13 are allowed to cross unintentionally due to inevitable fluctuations in the manufacturing conditions of the stretchable sheet 10. Each elastic filament 13 may extend linearly as long as it does not cross each other, or may extend while meandering.

  The fact that the filaments do not cross each other means that there are almost no intersections. When there is an intersection point, it means that there are a plurality of fibers between the intersection points. Usually, however, it is rare that the lengths of fibers existing between the intersection points coincide with each other industrially. If stretching is performed while the lengths of the fibers existing between the intersections are different, stress is applied only to the shorter fibers contained between the intersections. However, many fibers are not involved in elongation. When compared with fibers of the same weight, the shrinkage force becomes smaller as the number of fiber intersections increases. Therefore, cost is wasted. Considering expansion and contraction only in the vertical direction, if there are fibers in the horizontal direction like a net, the fibers in the horizontal direction are not only useless, but the intersections mentioned above occur, and the fibers in the vertical direction are also used in the same way. The part will occur.

  The direction in which the elastic filament 13 extends may coincide with the flow direction when the extensible sheets 11 and 12 are manufactured, or may be orthogonal to the flow direction when the sheets 11 and 12 are manufactured. When the stretchable sheet 10 is manufactured according to a preferable manufacturing method described later, the extending direction of the elastic filament 13 coincides with the flow direction at the time of manufacturing the extensible sheets 11 and 12.

  The elastic filament 13 is joined to the extensible sheets 11 and 12 in a substantially non-extended state. The extensible sheets 11 and 12 are non-stretchable and extensible. Since the elastic filament 13 is joined to the extensible sheets 11 and 12 in a state where the elastic filament 13 is not stretched, the stretchable sheet 10 of the present embodiment has an advantage that the stretchability does not decrease and the stretchability is not easily lowered. is there. Further, for example, when the elastic filament 13 is stretched twice and bonded to the extensible sheets 11 and 12, if it is temporarily returned to 1.3 times the initial value, it will be stretched only 1.54 times from this state. I can't. However, when pasting is performed in a non-stretched state, the initial origin when the stretchable sheet is stretched is different, so that the stretchable sheets 11 and 12 can be stretched or the elastic filament 13 can be stretched to the maximum elongation. There is an advantage that it can be extended.

  There is the following advantage in joining the elastic filament 13 to the extensible sheets 11 and 12 in a state where the elastic filament 13 is not elongated. The elastic sheet 10 of the present embodiment, for example, joins the substantially non-stretched elastic filament 13 to the non-stretched sheets 11 and 12 to form a take-up raw fabric (at this time, the elastic filament 13 is joined to the elastic sheet 13). Sheet 11 and 12 is non-stretchable), and this unstretched sheet is drawn out and stretched in another process (for example, tooth gap stretching) to make the unstretched sheets 11 and 12 into stretchable sheets. Manufactured. In the state of the original fabric, the original fabric is non-stretchable and non-stretchable, so that no external force acts on the elastic filament 13. As a result, there is an advantage that even if the original fabric is stored for a long period of time, relaxation due to elongation does not occur.

  The elastic filament 13 can be a thread-like synthetic rubber thread or natural rubber. Alternatively, it may be obtained by dry spinning (melt spinning) or wet spinning. Among these, in view of a suitable manufacturing method to be described later, the elastic filament 13 is preferably obtained by direct melt spinning without temporarily winding or storing the elastic filament 13.

  The elastic filament 13 is preferably obtained by stretching a molten resin discharged from a nozzle on a spinning line. By stretching, the polymer constituting the elastic filament 13 is molecularly oriented in the length direction of the elastic filament 13, so that the going / returning ratio at the time of 50% elongation, which will be described later, is increased and the hysteresis loss is reduced. Further, a thin elastic filament can be obtained by stretching. From this point of view, the elastic filament 13 is preferably stretched 1.1 to 400 times, particularly 4 to 100 times.

  In particular, the elastic filament 13 is preferably formed by being stretched in a state where the elastic resin is melted or softened. This makes it possible to obtain a sufficiently thin filament, and the texture is improved for reasons described later. Further, the elastic filament 13 is stretched in a state where the elastic resin is melted or softened, so that the elastic filament 13 which has become normal temperature after being bonded to the extensible sheets 11 and 12 does not show a force to shrink, It becomes the same state as having joined to the extensible sheets 11 and 12 in a non-extendable state. Specific operations for stretching in the present embodiment are as follows: (a) A resin as a raw material of the elastic filament 13 is melt-spun to obtain an unstretched yarn, and the elastic filament of the unstretched yarn is heated again to soften the temperature. (B) Operation for stretching in a state higher than (hard segment glass transition temperature Tg), and (b) operation for directly stretching a molten fiber obtained by melt spinning a resin as a raw material of the elastic filament 13 . When the stretchable sheet 10 is manufactured according to a preferable manufacturing method described later, the elastic filament 13 is obtained by directly stretching a molten fiber obtained by melt spinning.

  The elastic filament 13 obtained by drawing after spinning preferably has a diameter of 10 to 400 μm, particularly 100 to 200 μm. This range is determined in consideration of the texture of the stretchable sheet 10 and the productivity of the elastic filament 13. Specifically, if the diameter of the elastic filament 13 is too large, a step due to the elastic filament 13 is easily perceived when the elastic sheet 10 is touched. This step acts negatively on the texture of the stretchable sheet 10. From this point of view, it is preferable that the elastic filament 13 has a smaller diameter because only the texture of the extensible sheets 11 and 12 is easily perceived. Further, the elastic filament 13 is preferably thin in order to reduce the light transmittance of the extensible sheets 11 and 12 so as to provide a so-called body fluid color hiding performance. Furthermore, in the elastic expression process by the tooth space roll described later, the diameter of the elastic filament 13 is equal to or less than the tooth-to-tooth clearance between the tooth space rolls. Since the clearance is reduced at a higher point and is 500 μm or less, more preferably 400 μm or less, the elastic filament is less likely to be damaged (cracked or cut) during stretching. The ratio between the diameter of the elastic filament and the clearance is preferably 0.2 to 1, and more preferably 0.2 to 0.5. However, the smaller the elastic filament 13 is, the less easy it is to manufacture. Considering these, the diameter of the elastic filament 13 is preferably within the above-mentioned range.

  From the viewpoint of preventing the above-described step from being generated, the ratio of the diameter of the elastic filament 13 in the thickness direction of the elastic filament 13 to the thickness of the elastic sheet 10 is preferably 1 to 30%, particularly preferably 5 to 12%. .

  The elastic filament 13 may have a circular cross section, but may be elliptical or flat in some cases. For example, when the stretchable sheet 10 is manufactured according to the manufacturing method described later, the cross section of the elastic filament 13 tends to be flat. In this case, in the elastic sheet 10, the elastic filament 13 has a flat major axis substantially in the same direction as the planar direction of the elastic sheet 10 and a short axis substantially in the same direction as the thickness direction of the elastic sheet 10. It is preferable that they are arranged as described above.

  When the cross section of the elastic filament 13 is flat, the ratio of long axis / short axis (average flatness ratio) is 1.0 to 7.0, particularly 1.1 to 3.0. This is preferable from the viewpoint that the bonding strength between the filament 13 and the constituent materials of the sheets 11 and 12 and the hiding performance of the stretchable sheet 10 are increased. The elastic filaments 13 having a flat cross section are arranged so that the major axis direction thereof substantially coincides with the plane direction of the stretchable sheet 10. In addition, when the cross section of the elastic filament 13 is flat, the diameter of the elastic filament 13 means what averaged the major axis diameter and the minor axis diameter. The major axis in the elastic filament 13 having a flat shape refers to the length of the longest transverse line on the outer periphery of the elastic filament 13 extracted by microscopic observation. The short axis in the elastic filament 13 refers to the length of the short side when a rectangle having two sides parallel to the long axis determined as described above and circumscribing the outer periphery is drawn. These are measured with respect to five arbitrary elastic filaments, and the average flatness is defined as the average flatness, and the average diameter is defined as the diameter of the elastic filament.

  The elastic filament 13 is also preferably colored in a color different from the color of the extensible sheets 11 and 12. As a result, the elastic filament 13 can be seen through the sheet 11 and / or the sheet 12, and the design effect that the stretchable sheet 10 exhibits a striped pattern is exhibited. Such an effect becomes more remarkable particularly when the thickness and basis weight of the extensible sheets 11 and 12 are within the ranges described below.

  From the viewpoints of the stretchable sheet 10 exhibiting sufficient stretchability, the fabric-like texture, and the above-described design effects as necessary, the pitch of the adjacent elastic filaments 13 (adjacent The distance between the elastic filaments 13) is preferably 0.1 to 40 mm, particularly 1 to 20 mm, provided that the diameter of the elastic filament 13 is in the above-described range.

  The elastic filament 13 is joined to the extensible sheets 11 and 12 over its entire length. Here, “joined over the entire length” means that all the portions (extension fibers in the case of nonwoven fabric) of the extensible sheets 11 and 12 that are in contact with the elastic filament 13 are the elastic filament 13. The elastic filament 13 and the extensible sheets 11 and 12 are bonded in such a manner that there is no intentionally formed non-bonded portion in the elastic filament 13. Say. Since the elastic filament 13 is bonded to the extensible sheets 11 and 12 over the entire length, the bonding force between the elastic strand 13 and the extensible sheets 11 and 12 can be sufficiently increased. As a result, even if the stretchable sheet 10 is stretched, the elastic filament 13 is difficult to peel from the extensible sheets 11 and 12. If the elastic filament 13 is peeled off from the extensible sheets 11 and 12, in the natural state (relaxed state), floating occurs between the elastic filament 13 and the extensible sheets 11 and 12, and the elastic sheet 10 is wrinkled. It becomes easy to generate | occur | produce and it lacks the sense of unity as the elastic sheet 10 whole.

  As a mode of joining the elastic filament 13 and the extensible sheets 11 and 12, for example, fusion is mentioned. When the stretchable sheet 10 is manufactured according to a suitable manufacturing method described later, the elastic filament 13 is bonded to the extensible sheets 11 and 12 by fusion bonding. The fusion includes both a state in which the elastic filament 13 and the extensible sheets 11 and 12 are melted and bonded to each other, or a state in which either one is melted and the other bites into and adheres. According to this method, excessive heat is not applied to the extensible sheets 11 and 12, and the elastic filaments 13 are fused to the extensible sheets 11 and 12 before the elastic filaments 13 obtained by melt spinning are solidified. Therefore, only the site | part which exists around the elastic filament 13 among the extensible sheets 11 and 12 joins with the elastic filament 13, and the site | part in the position away from it has the texture of the extensible sheets 11 and 12. Since it is maintained as such, there is an advantage that the texture of the stretchable sheet 10 is kept good. In this case, before joining the extensible sheets 11 and 12 and the elastic filaments 13, an adhesive can be applied as an auxiliary joining means. Alternatively, after the extensible sheets 11 and 12 and the elastic filament 13 are joined, heat treatment (steam jet, heat embossing) or the like can be performed as an auxiliary joining means. However, these auxiliary joining means may damage the texture of the resulting stretchable sheet 10 or damage the elastic filament 13. Therefore, it is preferable to fuse the elastic filament 13 to the extensible sheets 11 and 12 with the heat of fusion.

  The stretchable sheet 10 is stretchable in the same direction as the direction in which the elastic filament 13 extends. The stretchability of the stretchable sheet 10 is expressed due to the elasticity of the elastic filament 13. When the stretchable sheet 10 is stretched in the same direction as the direction in which the elastic filament 13 extends, the elastic filament 13 and the extensible sheets 11 and 12 extend. When the stretching of the stretchable sheet 10 is released, the elastic filament 13 contracts, and the extensible sheets 11 and 12 return to the state before stretching with the contraction.

  In the stretchable sheet 10 of the present embodiment, there is no other elastic filament bonded in a state orthogonal to the elastic filament 13. Therefore, even if the stretchable sheet 10 is stretched in the same direction as the direction in which the elastic filament 13 extends, the stretchable sheet 10 stretches with little width shrinkage. That is, the stretchable sheet 10 has a substantially uniform width in the longitudinal direction in the stretched state. As a result, the handling property when the stretchable sheet 10 is conveyed in the extended state and processed is improved. Moreover, when the elastic sheet 10 is used as, for example, a back sheet of a disposable diaper, it is effectively prevented that a slippage or wrinkle occurs during wearing of the diaper. In addition, considering the configuration of the diaper and the movement of the user, non-uniform stretching occurs in the width direction, but there is almost no shrinkage in the width, and it is effective that the diaper is displaced or wrinkled. To be prevented. From this point of view, the stretchable sheet 10 preferably has a width shrinkage ratio of 1% to 10%, particularly 1% to 5% of the width before stretching when the stretchable sheet 10 is stretched 1.5 times. The width reduction can be calculated as (1−width after extension ÷ width before extension) × 100. The width after stretching is measured as follows. The sample is cut out with a width of 50 mm so that the length direction is substantially along the flow direction (within an angle difference of 15 degrees or less). The length is over 150 mm. While maintaining the width of the sample at 50 mm, both ends in the longitudinal direction of the sample are gripped at a gripping interval of 150 mm. At this time, care is taken so that the sample does not sag in the longitudinal direction and does not stretch. From this state, the width of the central portion in the length direction of the sample when the grip interval is extended to 1.5 times is measured, and the value is taken as the width after extension.

  The functional material 30 sandwiched between the extensible sheets 11 and 12 is used for imparting various functions to the stretchable sheet 10. The type of the functional material 30 can be appropriately selected according to the specific application of the stretchable sheet 10. For example, when it is desired to impart water absorption to the stretchable sheet 10, a water absorbent material such as a superabsorbent polymer can be used as the functional material 30. In the case where it is desired to impart deodorant properties, a deodorant can be used. A perfume can be used as the functional material 30 when it is desired to perfume the stretchable sheet 10. When the stretchable sheet 10 is desired to be used as a stretchable heating element, an oxidizable metal can be used as the functional material 30.

  The functional material 30 exists between the two sheets 11 and 12. Depending on the manufacturing conditions of the stretchable sheet 10, a part of the functional material 30 may adhere to the elastic filament 13. The amount of the functional material 30 included in the stretchable sheet 10 can be appropriately adjusted according to the specific application of the stretchable sheet 10 and the type of the functional material 30. When the amount of the functional material 30 contained in the stretchable sheet 10 is relatively large, as shown in FIG. 1, the stretchable sheets 11 and 12 are raised between two adjacent elastic filaments 13, A number of flanges 10a may be formed that extend in the same direction as the direction in which the elastic filament 13 extends.

  As described above, the functional material 30 may be in a joined state with the sheet 11 and / or the sheet 12, or may be in a non-joined state with the sheet 11 and the sheet 12. By being in a joined state, bias due to movement of the functional material 30 is less likely to occur when the stretchable sheet 10 is used. However, when the usage amount of the functional material 30 is not large, the functional material 30 easily enters and is supported between the constituent fibers of the extensible sheets 11 and 12 (when the sheets 11 and 12 are fiber sheets). Even if the sheets 11 and 12 are not joined, it is difficult for the deviation to occur. Further, when the absorbent polymer is used, it is distributed in a band shape, so that it is difficult to inhibit swelling at the time of water absorption, and the absorption rate is fast because the surface area when the liquid comes into contact is large. Furthermore, since the absorbent polymer can expand in the lateral direction even under pressure, even if it is thin, it has high absorption performance.

  Various types of functional materials 30 can be used. For example, it can be in the form of particles, coatings, fibers, or combinations thereof. The form in which the functional material 30 is used may be appropriately selected according to the specific application of the stretchable sheet 10.

  When the extensible sheets 11 and 12 are fiber sheets, the average interfiber distance of the fibers constituting the sheets 11 and 12 is preferably (average grain diameter−σ) or less, more preferably when the functional material is particles. 0.5 × (average particle diameter−σ) or less. σ is the standard deviation value of the particles. In the case of a needle shape, the average particle diameter is obtained as an average of the short axis and the long axis. The average interfiber distance is calculated by the following formula.

In the calculation of the average interfiber distance, the constituent fibers of the web are regarded as circular regardless of the cross-sectional shape. In the case of an irregular cross-sectional shape, the average value of the long axis and the short axis is taken as the fiber diameter. In the case of Y-shape or C-shape, the circumscribed circle is the fiber diameter. When the average interfiber distance is preferably 10 to 400 μm, more preferably 30 to 100 μm, it is possible to effectively prevent the functional material from falling off. Further, when the average basis weight of the functional material is preferably 1 to 500 g / m ² , more preferably 4 to 200 g / m ² , a sufficient holding function is exhibited even if the extensible sheets 11 and 12 are thin. I can do it.

  2A and 2B are longitudinal sectional views along the extending direction of the elastic filament 13 in the stretchable sheet 10 according to the embodiment of the present invention. The embodiment shown in FIGS. 2 (a) and 2 (b) is a form that remarkably develops when tooth gap extension is used in the elastic expression processing step in the manufacturing process of the stretchable sheet 10. Fig.2 (a) is a longitudinal cross-sectional view of the elastic sheet 10 in a natural state (relaxed state), and FIG.2 (b) is a longitudinal cross-sectional view of the elastic sheet 10 in an expansion | extension state. These drawings show the state of the stretchable sheet 10 when a nonwoven fabric is used as the sheet 11. In the natural state, the elastic sheet 10 is alternately formed with minute convex portions and concave portions extending in the same direction (a direction orthogonal to the extending direction of the elastic filament 13) on one surface and the other surface. Yes. At the position of the convex portion and the concave portion on one surface, the concave portion and the convex portion on the other surface are located. Specifically, it has a corrugated shape in which top portions 14 'corresponding to the convex portions and trough portions 14 "corresponding to the concave portions are alternately arranged. The top portions 14' and the trough portions 14" are connected via the ridge line portion 15 '. It is lined up. The thickness of the top portion 14 'and the valley portion 14 "is slightly smaller than the thickness of the ridge line portion 15', and is easier to transmit light than the ridge line portion 15 '. When the stretchable sheet 10 is viewed in plan view The top portion 14 ′, the ridge line portion 15 ′, and the valley portion 14 ″ extend in a direction orthogonal to the extending direction of the stretchable sheet 10. Therefore, in the stretchable sheet 10, in its natural state, a horizontal stripe pattern caused by the ridge portion 15 ′ that easily transmits light and the top portion 14 ′ and the valley portion 14 ″ that hardly transmit light appears slightly. The horizontal stripe pattern may become more conspicuous depending on conditions such as an elastic expression process described later.

  That is, as shown in FIG. 2 (b), in the stretchable stretchable sheet 10, the high basis weight portions 14 and the low basis weight portions 15 are alternately arranged along the extending direction of the elastic filaments 13. . Each of the portions 14 and 15 extends in a band shape in a direction orthogonal to the direction in which the elastic filament 13 extends. The high basis weight portions 14 and the low basis weight portions 15 are alternately arranged at a constant period. About the high basic weight part 14, what protrudes above the elastic sheet 10 and what protrudes below the elastic sheet 10 are arrange | positioned alternately. The high basis weight portion 14 protruding above the stretchable sheet 10 is derived from the top portion 14 ′ of the stretchable sheet 10 in the natural state shown in FIG. On the other hand, the high basis weight portion 14 projecting downward from the stretchable sheet 10 is derived from the valley portion 14 ″ in the stretchable sheet 10 in the natural state shown in FIG. 2A. 2 (a) is derived from the ridge line portion 15 'in the stretchable sheet 10 in the natural state shown in Fig. 2 (a) The high basis weight portion 14 and the low basis weight portion 15 emit light due to the difference in basis weight. As a result, the stretchable sheet 10 exhibits a horizontal stripe pattern extending in a direction perpendicular to the direction in which the elastic filament 13 extends, and the design is improved. Since the stretchable sheet 10 also exhibits a striped pattern due to the elastic filament 13, the stretchable sheet 10 has a lattice pattern in which this striped pattern is combined with the striped pattern due to the high basis weight portion 14 and the low basis weight portion 15. Will also present the design There even higher.

  The high basis weight portion 14 has a larger basis weight and a larger thickness than the low basis weight portion 15. As a result, the high basis weight portion 14 and the low basis weight portion 15 differ in the degree of light transmission, and a striped pattern is exhibited due to the difference. Each high basis weight portion 14 is substantially equal in width to each other, and similarly, each low basis weight portion 15 is also substantially equal in width to each other.

The thickness of the high basis weight portion 14 is preferably 0.3 to 10 mm, particularly preferably 0.5 to 1 mm. The thickness of the low basis weight portion 15 is preferably 0.1 to 3 mm, particularly preferably 0.2 to 0.6 mm from the viewpoints of stretchability and air permeability. The thickness is measured by the following method after the stretchable sheet 10 is left unloaded for 2 days or more in an environment of 20 ± 2 ° C. and 65 ± 5% RH. First, the stretchable sheet 10 is sandwiched between flat plates with a load of 0.5 cN / cm ^{2 in} a state where the stretchable sheet 10 is stretched 1.5 times. The cross section is observed with a microscope at a magnification of 50 to 200 times, and an average thickness is obtained in each field of view, and is obtained as an average value of the thicknesses of three fields of view. The high basic weight portion 14 and the low basic weight portion 15 are easily formed by manufacturing the stretchable sheet 10 according to the manufacturing method described later.

  Next, the constituent materials of the extensible sheets 11 and 12, the elastic filament 13, and the functional material 30 constituting the stretchable sheet 10 will be described. The extensible sheets 11 and 12 are made of a non-stretchable film material or fiber material. In the present embodiment, the extensible sheet 12 may be the same as the extensible sheet 11 described in detail below. In this case, the extensible sheet 12 can be the same or different from the extensible sheet 11. Therefore, regarding the extensible sheet 12, the explanation about the extensible sheet 11 described below will be replaced with the explanation of the extensible sheet 12. Here, the same type means sheets having the same manufacturing process, type of constituent resin, thickness, basis weight, and the like. When at least one of these is different, the sheets are different.

  As the extensible sheet 11, a film material or a fiber material (nonwoven fabric or paper) can be used as described above. The extensible sheet 11 may be substantially regularly broken or broken. By doing in this way, when the elastic sheet 10 is used, for example as a surface sheet of an absorbent article, it becomes possible to absorb water from the hole by this tear. Substantially regular breaks and breaks can be formed by post-processing after bonding by, for example, biting and stretching. Further, when the stretchable sheet 10 using thin paper as the extensible sheet 11 is applied to the absorbent body of the absorbent article, the tear or breakage serves as a water inlet and an absorbent article having a high absorption rate can be obtained. In these cases, the functional material 30 is preferably carried by an adhesive or the like.

  When the extensible sheet 11 is made of a film material, the film material is preferably water-impermeable or water-permeable. The film material is also preferably moisture permeable or moisture permeable. A particularly preferable film material is a non-water-permeable and moisture-permeable film (hereinafter also referred to as a non-stretchable moisture-permeable film). This non-stretchable moisture permeable film is obtained by, for example, melt-molding a resin composition obtained by kneading a material incompatible with the resin into a thermoplastic resin into a film shape, and the obtained film is uniaxial or biaxial. It is made porous by axial stretching. Examples of the thermoplastic resin that can be used include polyolefins such as polyethylene, polypropylene, and olefin copolymers. Examples of substances that are not compatible with thermoplastic resins include calcium carbonate, gypsum, calcium sulfate, calcium phosphate, magnesium carbonate, magnesium sulfate, hydrated silicic acid, anhydrous silicic acid, soda ash, sodium chloride, sodium sulfate, and barium sulfate. Inorganic fillers such as talc, clay, various cements, volcanic ash, shirasu, titanium oxide, iron oxide and carbon black, various metal powders, other inorganic substances, and organic metal salts mainly composed of inorganic substances. Moreover, polymers such as thermosetting resins such as phenol resin, epoxy resin, and sodium polyacrylate, or resins having a melting temperature higher than the molding temperature of the thermoplastic resin are mentioned. These substances are desirably used as a granular material having an average particle diameter of 50 μm or less, preferably 0.05 to 30 μm, particularly about 0.1 to 5 μm. The blending ratio of the thermoplastic resin and the substance is preferably 50 to 400 parts by weight, more preferably 60 to 300 parts by weight with respect to 100 parts by weight of the thermoplastic resin.

When the extensible sheet 11 is a film material having moisture permeability, the moisture permeability (measured at 30 ° C. and 90% RH according to JIS Z0208) is 0.4 to 6 g / (100 cm ² · hr), particularly It is preferably 0.8 to 4 g / (100 cm ² · hr). The water pressure resistance (JIS L1092) is preferably 0.5 m or more, particularly 2 m or more. Further, the sheet 11 made of a film material having a moisture permeability, on condition that the moisture permeability and water pressure resistance is in the range described above, a basis weight of 5 to 100 g / ^{m 2,} in particular at 10 to 30 g / ^{m 2} Preferably there is.

  When the extensible sheet 11 is a highly extensible film, the original film for use in this film is preferably unstretched or low-stretched. Such an unstretched or low-stretched film is preferably stretched at a magnification of 1.0 to 3 times, more preferably 1.0 to 1.5 times. Thereby, the extensible sheet 11 having high strength and high elongation can be obtained. Moreover, it becomes difficult to generate | occur | produce a tear etc. at the time of extending | stretching by post-processing. In the case of a moisture permeable film, a pinhole is hardly generated and a highly permeable film is obtained.

  The extensible sheet 11 can also be a thin paper. As the thin paper, natural paper, synthetic paper, a mount used for an absorbent body of an absorbent article, and the like can be used. The stretchable sheet 10 when thin paper is used as the extensible sheet 11 is useful as an auxiliary agent for instantaneous absorption at the time of water absorption and as diffusion paper. As the thin paper, functional paper having effects such as deodorization and antibacterial can be used. When the extensible sheet 11 is a highly extensible thin paper, such a thin paper is preferably creped. In that case, the crepe rate is preferably 10% or more, more preferably 30% or more.

  The stretch sheet 11 can also be a nonwoven fabric. As the fibers constituting the nonwoven fabric, substantially inelastic fibers are used. Examples thereof include fibers made of polyethylene (PE), polypropylene (PP), polyester (PET or PBT), polyamide, and the like. The fibers constituting the nonwoven fabric may be short fibers or long fibers, and may be hydrophilic or water repellent. Further, core-sheath type or side-by-side composite fibers, split fibers, irregularly shaped cross-section fibers, crimped fibers, heat-shrinkable fibers, and the like can also be used. These fibers can be used singly or in combination of two or more. The nonwoven can be a continuous filament or short fiber nonwoven. In particular, from the viewpoint of making the stretchable sheet 10 thick and bulky, the nonwoven fabric is preferably a short fiber nonwoven fabric. When the stretchable sheet 10 is used as a member that comes into contact with the skin, a short fiber nonwoven fabric with good texture may be used on the skin contact side, and a high-strength continuous filament nonwoven fabric may be used on the opposite surface.

  The non-woven fabric is preferably composed of two or more components of a low melting point component and a high melting point component. In that case, the constituent fibers are joined at fiber intersections by at least thermal fusion of the low melting point components. As the core-sheath type composite fiber composed of two or more components of a low melting point component and a high melting point component, those having a core of high melting point PET, PP and a sheath of low melting point PET, PP, PE are preferable.

The thickness of the nonwoven fabric is preferably 0.05 to 5 mm, more preferably 0.1 to 1.0 mm, and still more preferably 0.15 to 0.5 mm. The thickness was measured by sandwiching the flat sheet between flat plates with a load of 0.5 cN / cm ² and observing the cross section of the stretchable sheet 10 with a microscope at a magnification of 50 to 200 times. It can obtain | require as an average value of thickness. The thickness of the entire stretchable sheet 10 is obtained by measuring the distance between the flat plates. The basis weight of the nonwoven fabric is preferably ³ to 100 g / m ² , particularly preferably 10 to 30 g / m ² , from the viewpoints of texture, thickness, and design properties.

  The extensible sheet 11 made of a nonwoven fabric is preferably made of substantially inelastic fibers from the viewpoints of texture, stickiness and the like. The proportion of inelastic fibers in the nonwoven fabric is preferably 70% by weight or more, particularly 90% by weight or more, and particularly preferably 100% by weight. Moreover, the substantially inelastic fiber may contain a small amount of elastic resin in the inelastic resin. In this case, the proportion of the inelastic resin is preferably 70% by weight or more, more preferably 90% by weight, and still more preferably 100% by weight.

  When the extensible sheet 11 made of a non-woven fabric is a highly extensible non-woven fabric, it is particularly preferable to use a non-elastic fiber whose fiber thickness is not uniform in the length direction (hereinafter referred to as this). Fiber is called indefinite fiber). That is, indefinite-diameter fibers have a large fiber cross-sectional area (diameter) and a small part when viewed along the length direction. In the indefinite fiber, the diameter (cross-sectional area) may continuously change from the smallest part to the largest part. Alternatively, the diameter (cross-sectional area) of the fiber may change in a substantially step shape, as in the necking phenomenon observed in the undrawn yarn drawing process. An example of an inelastic fiber in which the fiber diameter (cross-sectional area) is changed in a substantially step shape is shown in FIG.

  The inelastic fiber is made from a fiber having a constant fiber diameter and a high elongation (for example, the maximum elongation of the fiber is 80 to 800%, particularly 120 to 650%). It is preferable at the point obtained. The elongation of the fiber conforms to JIS L-1015, based on the measurement environment temperature and humidity 20 ± 2 ° C., 65 ± 5% RH, tensile tester gripping distance 20 mm, tensile speed 20 mm / min. To do. In addition, when collecting fibers from an already manufactured non-woven fabric and measuring the elongation, when the gripping interval cannot be 20 mm, that is, when the length of the fiber to be measured is less than 20 mm, the gripping interval is set. Measure by setting to 10 mm or 5 mm.

  The high-stretch fiber is preferably a low-stretch inelastic fiber. When the stretchable sheet 10 of the present embodiment is manufactured using a low-stretched inelastic fiber as a raw material in accordance with the manufacturing method described later, the stretched low-stretched fiber is stretched in the elastic expression treatment, resulting in a thin portion of the fiber. An indefinite fiber is formed. As a result, in the elastic expression treatment of the stretchable sheet 10 of the present embodiment, the nonwoven fabric is changed into a form that is easily stretched structurally, but the entire nonwoven fabric structure is easily stretched by stretching the fibers, It becomes possible to minimize the breakage of the joining points between the amorphous fibers and the joining points of the extensible sheet 11 and the elastic filaments 13, and the strength of the stretchable sheet 10 is increased while maintaining the stretchability. can do. That is, the stretchable sheet 10 having both high elongation and high strength is obtained. Further, in the elastic expression treatment, the bonding between the indefinite fibers is less likely to be destroyed, which also has the effect of making the nonwoven fabric less likely to become fluffy. This is advantageous from the viewpoint of improving the appearance of the stretchable sheet 10 of the present embodiment.

  Furthermore, by using the low-stretched fiber as a raw material, the number (length) of thin fibers is substantially increased as compared to before fiber stretching. Thereby, the light impermeability of the stretchable sheet 10 of the present embodiment is improved.

  In addition, if the region where the indefinite fiber is densely present is periodically changing on the nonwoven fabric, the surface of the nonwoven fabric will be finely wavy and the touch will be good. There is also a positive effect. In this case, the period of change, that is, the distance between the thick part in the nonwoven fabric and the adjacent thick part is preferably 0.5 mm to 10 mm, particularly 2 to 5 mm. This period can be measured from microscopic observation of the nonwoven fabric. The diameter of the amorphous fiber is measured by the following procedures (1) to (5).

(1) The extensible sheet 11 is sampled from an area of 5 mm × 5 mm or more on the surface of the stretchable sheet 10. At this time, the sample may be collected by separating the extensible sheet 11 from the elastic filament 13 or the entire stretchable sheet 10 may be collected. (2) The collected sample is fixed to the SEM observation sample stage. At this time, in order to easily observe the sample, the sample may be fixed to the sample stage with a double-sided tape in a state where the sample is stretched to such an extent that the structure of the sample is not destroyed (until the nonwoven fabric can be loosened). The stretch amount at this time is, for example, approximately equal to or less than the stretching ratio at which the precursor of the stretchable sheet 10 is stretched in the stretching step when the step of producing the stretchable sheet 10 (elastic development treatment) is used.
(3) SEM observation is performed at a magnification of 200. The visual field area at one place is about 0.4 mm × 0.4 mm or more, and five places are observed.
(4) Fibers are extracted at random, and the diameter is measured in units of 0.1 μm at 20 or more locations every 10 μm in the fiber axis direction (fiber fusion points or broken parts are not included in the measurement. ). Four or more fibers are measured for each field, and a total of 20 fibers are measured for five fields.
(5) Extract the maximum diameter and the minimum diameter of each of the ten fibers from these values. When the difference between the maximum diameter and the minimum diameter of one fiber is 1 μm and the relationship between the position in the fiber axis direction and the change in diameter is graphed, a fiber having a maximum position or two or more minimum positions is called an amorphous fiber.

  From the viewpoint of making the above effects even more remarkable, the indefinite fiber is preferably 2 to 15 μm in thickness at the thinnest part, more preferably 5 to 12 μm, and preferably 10 to 10 at the thickest part. It is 40 μm, more preferably 12 to 30 μm. The difference between the maximum diameter and the minimum diameter of the indefinite fiber is preferably 3 μm or more, particularly 5 μm or more, and particularly preferably 10 μm or more. Moreover, the value of the fiber diameter ratio defined by “maximum fiber diameter / minimum fiber diameter” is preferably 1 to 15, more preferably 1.2 to 10, and 2 to 5. Even more preferred.

  The non-constant fiber preferably has an inter-fiber fusion point strength higher than the strength at 100% elongation of the non-constant fiber. Thereby, in the elastic expression processing step when manufacturing the elastic sheet 10, when the elastic sheet 10 before the elastic expression process is stretched and subjected to the elastic expression processing, the fibers of the extensible sheet 11 before the elastic expression process are fused. The point breakage is less likely to occur, and the strength of the elastic sheet 10 obtained through the elastic expression treatment process is less likely to be lower than the strength of the elastic sheet 10 before the elastic expression treatment. The fusion point strength is measured according to the description in paragraph [0040] of Japanese Patent Application Laid-Open No. 2004-218183 relating to the previous application of the present applicant. The strength at 100% elongation is measured using a tensile tester under conditions of a distance between chucks of 20 mm and a tensile speed of 20 mm / min.

  The low-stretched inelastic fibers described above include both fibers drawn at a low draw ratio after spinning and unstretched fibers, that is, unstretched fibers. As the low-stretched fiber, it is preferable to use a fiber having a high elongation of 80 to 800%, particularly 120 to 650% as described above. By using a low-stretched fiber having an elongation in this range, the fiber is successfully stretched by a stretching apparatus 22 shown in FIG. 4 to be described later, and an indefinite fiber is easily formed. The fiber diameter of the low-stretched fiber is preferably 10 to 35 μm, particularly preferably 12 to 30 μm.

  As described above, the non-constant diameter fiber is preferably made from a low-stretched fiber having a constant fiber diameter as a raw material. In this case, the low-stretched fiber may be a fiber made of a single raw material, or a composite fiber using two or more raw materials, such as a core-sheath type composite fiber or a side-by-side type composite fiber. Good. Considering the ease of joining the indefinite diameter fibers and the ease of joining the extensible sheet 11 and the elastic filament 13, it is preferable to use a composite fiber. In the case of the core-sheath type composite fiber, the core is preferably polyester (PET or PBT) or polypropylene (PP), and the sheath is preferably low melting point polyester (PET or PBT), polypropylene (PP) or polyethylene (PE). In particular, when these composite fibers are used, when the elastic filament 13 contains a polyolefin-based elastomer, it is preferable in that the thermal fusion between the elastic filament 13 and the constituent fibers of the extensible sheet 11 becomes strong and layer peeling does not easily occur.

  The non-constant diameter fiber may be a short fiber such as a staple fiber, or may be a long fiber such as a continuous filament. In view of a preferable method for manufacturing the stretchable sheet 10 described later, it is preferable to use short fibers. The indefinite fiber may be hydrophilic or water repellent.

  The extensible sheet 11 made of a non-woven fabric may be composed of only indefinite diameter fibers, or may contain other inelastic fibers having a constant diameter in addition to the indefinite diameter fibers. Other inelastic fibers include those mentioned above. When the non-woven fabric contains non-elastic fibers having other fixed diameters in addition to the non-constant diameter fibers, the blending amount of the other non-elastic fibers is preferably 1 to 30% by weight, particularly preferably 5 to 20% by weight. .

  As described above, the elastic filament 13 is made of, for example, an elastic resin such as a thermoplastic elastomer or rubber. In particular, when a thermoplastic elastomer is used as a raw material for the elastic resin, melt spinning using an extruder is possible in the same manner as a normal thermoplastic resin, and the filaments thus obtained are easy to heat-seal, It is suitable for the elastic sheet of this embodiment. Examples of the thermoplastic elastomer include SBS (styrene-butadiene-styrene), SIS (styrene-isoprene-styrene), SEBS (styrene-ethylene-butadiene-styrene), and SEPS (styrene-ethylene-propylene-styrene). And olefin elastomers (ethylene-based α-olefin elastomers, propylene-based elastomers copolymerized with ethylene / butene / octene), polyester-based elastomers, and polyurethane-based elastomers. These can be used individually by 1 type or in combination of 2 or more types. A core-sheath type or side-by-side type composite fiber made of these resins can also be used. In particular, use of a styrene-based elastomer, an olefin-based elastomer, or a combination thereof is preferable in terms of moldability, elastic properties, and cost of the elastic filament 13.

  As the functional material 30, when the material 30 is, for example, a particle, a hydrogel particle such as a superabsorbent polymer, a deodorant or antibacterial particle (such as activated carbon or zeolite), or a particle containing a fragrance (micro Capsules, etc.), particles of oxidizable metal (iron powder, etc.), and the like can be used. The particle size of these particles can be appropriately selected according to the type of the functional material 30 and the specific application of the stretchable sheet 10. When the functional material 30 is a fiber, for example, pulp fiber, cellulose fiber, fibrous activated carbon, fibrous metal, coiled cushioning fiber, or the like can be used. When the functional material is a coated material, for example, a functional ink such as gravure ink or flexographic ink, an emulsion liquid, or a liquid in which the functional material is dispersed with a binder can be applied. As the binder, polyvinyl acetate resin, carboxymethyl cellulose resin, nitrocellulose, polyamide, polyurethane, acrylic acid polymer, vinyl chloride copolymer, epoxy resin, silicone resin, or the like can be used. Synthetic resin (polyacrylic acid, polyacrylamide, polyethylene oxide, polyethyleneimine, urea, melamine, alkyd, polyvinyl alcohol, polyvinyl methyl ether, polyvinyl methyl ether / maleic anhydride copolymer) , Polyvinylpyrrolidone, polyvinyloxalidone, polyvinylsulfonic acid), semi-synthetic resin (propylene glycol alginate, low methoxy pectin, dextran, xanthan gum, pregelatinized starch, carboxymethyl starch, hydroxymethyl starch, hydroxypropyl starch, microcrystalline cellulose, Carboxymethylcellulose (Na salt), methylcellulose, hydroxypropylmethylcellulose, methylethylcellulose, hydroxy Lopyr cellulose), natural resin (agar, alginate, carrageenan, farsellan, gum arabic, guar gum, tragacanth gum, karaya gum, pectin, larch gum, locust bean gum, guar seed gum, silium seed gum, quince seed gum, tamarind seed gum, Wheat, rice, corn, waxy maize, sorghum, waxy sorghum, potato, kudzu, tapioca, konjac, gelatin, glue, casein, alpmin, gluten, soybean protein) and the like. Among these, it is preferable to use polyvinyl alcohol, hydroxypropyl cellulose, polyvinyl pyrrolidone, carboxymethyl cellulose, and sodium acrylate.

  Next, the preferable manufacturing method of the elastic sheet 10 of this embodiment is demonstrated, referring FIG. In this manufacturing method, a large number of molten elastic filaments 13 spun from the spinning nozzle 16 are drawn and stretched at a predetermined speed, and the elastic filaments 13 do not cross each other before the elastic filaments 13 are solidified. The elastic filaments 13 are fused to the extensible sheets 11 and 12 so as to be arranged in one direction, and the functional material 30 is supplied between the extensible sheets 11 and 12, and the elastic filaments 13 are fused. In addition, a composite 19 in which the functional material 30 is sandwiched between the extensible sheets 11 and 12 is obtained, and the composite 19 is elastically treated along the direction in which the elastic filaments 13 are extended. 19 is given elasticity.

  The spinning nozzle 16 is provided in the spinning head 17. The spinning head 17 is connected to an extruder. Resin can also be supplied to the spinning head 17 via a gear pump. The elastic resin melt-kneaded by the extruder is supplied to the spinning head 17. The spinning head 17 has a large number of spinning nozzles 16 arranged in a straight line. The spinning nozzle 16 is disposed along the width direction of the extensible sheets 11 and 12. The interval between the adjacent spinning nozzles 16 corresponds to the interval between the elastic filaments 13 in the target stretchable sheet 10. The spinning nozzle 16 is usually circular, and its diameter affects the diameter of the elastic filament 13 and the draw ratio. From this viewpoint, the diameter of the spinning nozzle 16 is preferably 0.1 to 2 mm, particularly preferably 0.2 to 0.6 mm. For the purpose of increasing the bonding strength with the extensible sheets 11 and 12, the purpose of increasing the spinnability of the elastic filament 13, and the purpose of improving the expansion / contraction characteristics of the expansion / contraction sheet 10, the elastic filament 13 is in a composite form (side-by-side, core sheath, Sea-island structure). Specifically, it is preferable to combine a PP elastomer resin and a styrene elastomer resin.

  The spun elastic filaments 13 spun together with the extensible sheets 11 and 12 fed from the original fabric at the same speed, and are sandwiched between the sheets 11 and 12 and taken up at a predetermined speed. At the time of merging, the functional material 30 is supplied from the functional material supply device 23 to the merging portion. As the supply device 23, an appropriate device is used according to the type of the functional material 30. When the functional material 30 is, for example, particles, various spraying devices can be used as the supply device 23. The functional material 30 supplied from a cutting device such as a screw is conveyed by an air current, and from a chamber or the like. The method of spraying, the method of spraying the functional material 30 from a shaking sieve or a conveyor, etc. are mentioned. As an auxiliary means, there are used a method in which the functional material 30 is dispersed while being charged, a method in which the functional material 30 is dispersed while applying vibration with ultrasonic waves, and a method in which the functional material 30 is sprayed by airflow mixing. Air, water vapor, compressed air, hot air, or the like can be used for transporting the functional material 30.

  When the functional material 30 is, for example, a fiber, as the supply device 23, a defibrating machine used for defibrating a pulp sheet, a defibrating machine used for a short fiber nonwoven fabric, or a card machine is used. The fiber is conveyed by an air current or a conveyor. In the case where the functional material 30 is, for example, a coating, the supply device 23 is a gravure printing, flexographic printing, anchor coating device, spray device, die coating, (two, three, reverse) roll coater, comma coater, dipping , Hot melt coating devices (coating, spiral, bead, curtain, spray, omega, summit, dulaueve) are used. When drying is necessary, hot air, cold air, infrared rays, UV rays, microwaves, direct heat conduction (such as a Yankee dryer) is used. A supply device used for each of particles, fibers, and coating can be used in combination. It is also possible to use a mixture of particles and fibers.

  As a method of merging the functional material 30 with the sheet 11 and / or the sheet 12, a method of laminating the functional material 30 in the form of the sheet 11 and / or the sheet 12, laminating or applying, and then laminating, directly to the joint of the laminate There are a supply method and a supply method after lamination. Preferably, it is preferable that the functional material 30 is spilled on the sheet 11 and / or the sheet 12 after being spread, laminated, or coated, in order to reduce the spillage of the functional material 30 during processing. The surface to be spread, laminated, or applied is not limited, but is preferably the inner surface (elastic filament side) of the sheet 11 and / or the sheet 12 in terms of preventing the functional material 30 from spilling.

  When supplying the functional material 30, an adhesive or the like for joining the material 30 to the sheet 11 and / or the sheet 12 may be supplied from the supply device 23 together with the material 30. Or you may supply from the apparatus different from the supply apparatus 23 using the apparatus.

  In order to carry the functional material 30 on the extensible sheets 11 and 12, mechanical entanglement such as hydroentanglement and needle punch, hot air, steam, and hot embossing can be used as auxiliary means. From the viewpoint of preventing the functional material 30 from leaking, it is also preferable to apply an adhesive to the functional material 30. When the functional material 30 exhibits water absorption, it is preferably adsorbed with mist-like water. These promote entanglement, adhesion, and fusion between the functional material 30 and the extensible sheets 11 and 12 and the elastic filament 13.

  The take-up speed when the elastic filament 13 is taken up by joining the extensible sheets 11 and 12 coincides with the feeding speed of the extensible sheets 11 and 12. The take-up speed of the elastic filament 13 affects the diameter and the draw ratio of the elastic filament 13. The tension generated in the elastic filament 13 by stretching prevents the elastic filament 13 from being disturbed due to wind or static electricity when the elastic filament 13 is bonded to the extensible sheets 11 and 12. Thereby, the elastic filaments can be arranged in one direction without crossing each other. From these viewpoints, the drawing speed of the elastic filament 13 is 1.1 to 400 times, particularly 4 to 100 times, more preferably 10 to 80 times the resin discharge speed in the spinning nozzle hole. It is preferable to adjust.

  The elastic filament 13 joins the extensible sheets 11 and 12 before solidification, that is, in a state where it can be fused. As a result, the elastic filament 13 is fused to the sheets 11 and 12 while being sandwiched between the extensible sheets 11 and 12. That is, the elastic filament 13 is pulled and stretched while the elastic filament before solidification is fused to the stretchable sheets 11 and 12 to be conveyed. At this time, a part of the functional material 30 may be fused to the elastic filament 13. When the elastic filament 13 is fused, heat is not applied to the extensible sheets 11 and 12 from the outside. That is, the elastic filament 13 and the extensible sheets 11 and 12 are fused only by the heat of fusion caused by the elastic filament 13 that can be fused. As a result, in the extensible sheets 11 and 12, only a portion existing around the elastic filament 13 is fused with the elastic filament, and a portion existing at a position farther than that is not fused. As a result, since the heat applied to the extensible sheets 11 and 12 is kept to a minimum, the good texture inherent to the sheets 11 and 12 themselves is maintained. Thereby, the texture of the stretchable sheet 10 obtained becomes favorable.

  Until the spun elastic filament 13 joins the extensible sheets 11 and 12, the elastic filament 13 is stretched and molecules are oriented in the stretching direction. Also, the diameter is reduced. Due to the molecular orientation, an elastic filament 13 having a small strength going / return ratio (hysteresis) at 50% elongation can be obtained. From the viewpoint of sufficiently stretching the elastic filament 13 and from the viewpoint of preventing the elastic filament 13 from being broken, a wind (hot air or cold air) of a predetermined temperature is blown onto the spun elastic filament 13 to set the temperature of the elastic filament 13. You may adjust.

  The stretching of the elastic filament 13 may be not only stretching in the molten state of the raw material resin (melt stretching), but also stretching in the softened state (softening stretching) in the cooling process. The molten state is a state in which the resin flows when an external force is applied. The melting temperature of the resin is measured as a peak temperature of Tan δ by viscoelasticity measurement (for example, measured by adding vibration strain in the rotational direction to a resin sandwiched between circular parallel plates). In order to prevent thread breakage when using an elastic resin, it is preferable to secure a long stretch section. Similarly, the melting temperature of the elastic resin is preferably 130 to 300 ° C. so that the yarn breakage does not occur. Furthermore, the melting temperature is preferably 220 ° C. or less from the viewpoint of the heat resistance of the elastic resin. The molding temperature (die temperature) of the elastic filament 13 is preferably + 50 ° C. or more of the melting temperature of the raw material resin in order to increase the fluidity of the resin and improve the moldability, and is preferably + 110 ° C. or less for heat resistance. The softening temperature is measured as the Tg temperature in the viscoelastic property of the measurement sample of the elastic resin in sheet form. The range from the softening temperature to the melting temperature is called a softened state. Moreover, the state of temperature lower than softening temperature is called solidified state. The softening temperature is preferably 60 ° C. or higher, and more preferably 80 ° C. to 180 ° C., from the viewpoint of the growth of elastic resin crystals during storage of the stretchable sheet 10 and the decrease in stretchability of the stretchable sheet 10 due to body temperature.

  The temperature of the elastic filament 13 when the elastic filament 13 and the extensible sheets 11 and 12 are bonded is preferably 100 ° C. or higher in order to ensure fiber fusion. More preferably, it is 120 degreeC or more, More preferably, it is 140 degreeC or more. Further, from the viewpoint of obtaining the stretchable sheet 10 having a good stretchability by maintaining the shape of the elastic filament 13, the temperature of the elastic filament is preferably 180 ° C. or lower. More preferably, it is 160 degrees C or less. As a result, the optimum filament temperature is in the range of 120 to 160 ° C, more preferably 140 to 160 ° C. The bonding temperature is observed using a film made of a modified polyethylene or a modified polypropylene having a melting point different from the melting point of the elastic resin constituting the elastic filament as a laminate base material to be bonded to the elastic filament 13. Can be measured. At this time, if the elastic filament and the laminate base material are fused, the joining temperature is equal to or higher than the melting point of the laminate base material.

  At the time of joining the elastic filament 13 and the extensible sheets 11 and 12, the elastic filament 13 is substantially in a non-extended state (a state in which the elastic filament 13 does not shrink when an external force is removed). Further, when the elastic filaments 13 are joined with the extensible sheets 11 and 12, the elastic filaments 13 are arranged in one direction without crossing each other. Then, the elastic filament 13 is joined with the extensible sheets 11 and 12, and the elastic filament 13 is sandwiched between the sheets 11 and 12, and these three members are clamped by a pair of nip rolls 18 and 18. The condition of the clamping pressure affects the texture of the stretchable sheet 10 obtained. If the pinching pressure is too large, the elastic filament 13 tends to bite into the extensible sheets 11 and 12, and the texture of the stretchable sheet 10 obtained due to this tends to be lowered. From this point of view, the clamping pressure by the nip rolls 18 and 18 is sufficient to contact the elastic filament 13 with the extensible sheets 11 and 12, and an excessively high clamping pressure is not required.

  Another condition for the clamping pressure by the nip roll 18 is the temperature of the nip roll 18. As a result of the study by the present inventors, it is better not to heat the nip roll 18 in a heated state (that is, to leave it to the result), or to perform the pressing while cooling, a better texture. It was found that the elastic sheet 10 was obtained. When cooling the nip roll 18, it is preferable to use a coolant such as cooling water and adjust the temperature so that the surface setting temperature of the nip roll 18 is 10 to 50 ° C.

  Thus, the composite 19 in which the elastic filament 13 and the functional material 30 are sandwiched between the extensible sheets 11 and 12 is obtained. When the stretchable sheets 11 and 12 are inherently stretchable, the composite 19 becomes the stretchable sheet 10 itself. On the other hand, when the extensible sheets 11 and 12 that do not inherently have extensibility are used, the composite 19 including the extensible sheets 11 and 12 is elastically treated along the direction in which the elastic filament 13 extends. Then, an operation of imparting stretchability to the composite 19 is performed. Specific means for the elastic development treatment include, as described above, heat treatment, inter-roll stretching, biting and stretching with tooth gaps and gears, and tensile stretching with a tenter. In the following description, biting and stretching, which is a particularly preferable means among these means, will be described. In biting and stretching, an elastic expression processing device 22 including a pair of tooth gap rolls 20 and 21 in which teeth and roots are alternately formed in the circumferential direction is used, and the composite 19 is conveyed in its conveying direction, that is, an elastic filament. The elastic development process is performed along the extending direction of 13.

  The elastic expression processing device 22 has a known lifting mechanism (not shown) for vertically displacing the pivot portion of one or both of the tooth gap rolls 20 and 21, and the interval between the tooth gap rolls 20 and 21 can be adjusted. It has become. In this manufacturing method, each tooth gap roll 20 and 21 is inserted freely between the teeth of one tooth gap roll 21 and the tooth of the other tooth gap roll 21 is one tooth. It combines so that it may be loosely inserted between the teeth of the groove roll 20, and the composite body 19 is inserted between the both tooth groove rolls 20 and 21 of the state, and this is elastically processed.

  In the elastic expression processing device 22, both the pair of tooth groove rolls 20 and 21 may be driven by a driving source (co-rotating roll), and only one tooth groove roll 20 or 21 is driven by the driving source. In this manufacturing method, only the lower tooth gap roll 21 is driven by the drive source, and the upper tooth groove roll 20 is connected to the drive source. Instead, it is driven (rotated) as the tooth gap roll 21 rotates. The use of the accompanying roll is preferable in that the high basis weight portion 14 and the low basis weight portion 15 easily appear in a striped pattern on the stretchable sheet 10 after the elastic expression treatment, and the design of the stretchable sheet 10 is improved. . As the tooth profile of the tooth gap rolls 20 and 21, a general involute tooth profile and a cycloid tooth profile are used. However, these tooth widths are narrowed and backlash (gap between teeth of a pair of meshed rolls). A larger one is preferred. The backlash value is preferably 0.3 mm to 3 mm, more preferably 0.5 mm to 1.5 mm.

  FIG. 5 schematically shows a state in which the composite 19 is subjected to an elastic expression process. When the composite 19 passes between the tooth gap rolls 20 and 21, the composite 19 is in a region that contacts the teeth 23 and 24 of the tooth gap rolls 20 and 21 (between P 3 and P 2 and between P 1 and P 4). Is hardly stretched. On the other hand, in the region (between P2 and P1) pressed toward the tooth surface of the tooth 23 of the tooth space roll 20 that is the driven roll by the tooth surface of the tooth 24 of the tooth space roller 21 that is the driving roll. The two teeth 20 and 21 are greatly stretched. Further, in the region (between P4 and P3) that is separated from the tooth 23 of the tooth space roll 20 by the tip of the tooth 24 of the tooth space roll 21, it is not as large as the region (between P2 and P1), but is greatly stretched. The

  The composite 19 is hardly stretched as described above in the region (between P3 and P2 and between P1 and P4) in contact with the tips of the teeth 23 and 24 of the tooth gap rolls 20 and 21, but the teeth 23 and 24 are as described above. Is pushed in the radial direction, that is, in the thickness direction of the composite 19, so that it becomes thinner in the thickness direction. However, because the region (between P3 and P2) and the region (between P1 and P4) are in the opposite direction, the thinning direction is the opposite direction.

  The stretching process can efficiently stretch the sheets 11 and 12 in the composite 19 while imparting stretchability to the composite 19 while preventing the elastic filament 13 and the extensible sheets 11 and 12 from peeling off. it can. And the area | region (between P2-P1 and between P4-P3) extended | stretched greatly becomes the low basic weight part 15, and the area | region (between P3-P2 and between P1-P4) hardly extended becomes the high basic weight part 14.

  In particular, when the sheet 12 includes low-stretched fibers, the fibers are stretched and thinned between (P2-P1) and (P4-P3) described above, and the thickness thereof periodically changes. An indefinite fiber is formed. The stretching of the low-stretched fibers varies depending on the distance between (P2-P1) and (P4-P3).

  When the sheet 11 and / or the sheet 12 includes low-stretched fibers, the stretching force by the tooth gap rolls 20 and 21 mainly acts on stretching of the low-stretched fibers, and the extensible sheets 11 and 12 and the elastic filaments 13 Excessive force is not applied to the joint area. As a result, the composite 19 can be efficiently stretched while preventing breakage of the bonded portion and peeling of the extensible sheets 11 and 12 and the elastic filament 13. Further, by this stretching, as shown in FIG. 6, the stretchable sheets 11 and 12 are sufficiently stretched without breaking the bonding between the fibers, whereby the stretchable sheets 11 and 12 are free of the elastic filaments 13. The degree of inhibiting expansion and contraction is greatly reduced. As a result, according to this production method, the stretchable sheet 10 having high strength and high stretchability and having a good appearance with little tearing and fluffing can be efficiently produced. In FIG. 6, the thickness of the inelastic fiber generated by stretching is uniformly expressed for convenience.

  As described above, when the sheet 11 and / or the sheet 12 includes low-stretched fibers, the fibers are successfully stretched, and the joint between the fibers is not broken by stretching. Decrease in strength of the conductive sheets 11 and 12 is suppressed as much as possible. Specifically, the ratio of the tensile strength of the stretchable sheet 10 obtained after the elastic expression treatment to the tensile strength of the composite 19 before the elastic expression treatment is 0.3 to 0.99, particularly 0.5 to 0.99. Furthermore, it becomes a value close to 1 of 0.7 to 0.99. The tensile strength mentioned here is measured according to the maximum strength measuring method described below.

<Measurement of maximum strength>
A rectangular test piece was cut out in a size of 200 mm in the direction of expansion and contraction of the stretchable sheet 10 and 50 mm in a direction perpendicular thereto. The distance between chucks was 150 mm. The test piece was extended at a speed of 300 mm / min in the expansion / contraction direction of the elastic sheet 10, and the load at that time was measured. The load at the maximum point at that time was defined as the maximum strength. By the same method, the maximum strength of the composite 19 before the elastic expression treatment was also measured. The maximum strength is measured using a tensile tester AG-1kNIS manufactured by Shimadzu Corporation under the conditions of a measurement environment of 20 ± 2 ° C. and a humidity of 65 ± 5% RH.

  The composite body 19 is elastically treated by the pair of tooth space rolls 20 and 21, whereby the intended stretchable sheet 10 is obtained. After the obtained elastic sheet 10 passes through the tooth gap rolls 20 and 21, the stretched state in the MD direction is quickly released by its own contraction restoring force. As a result, the length of the stretchable sheet 10 is generally restored in the transport direction. Thereby, in the extended state, the high basis weight portions 14 and the low basis weight portions 15 are alternately arranged in the extending direction of the elastic filaments 13. When the stretched state is released, the stretched state may be completely released, or the stretched state may be released in a state where a certain stretched state is maintained as long as stretchability is exhibited.

  By the elastic expression processing, the thickness of the stretchable sheet 10 is preferably 1.1 to 4 times, particularly 1.3 to 3 times the thickness of the composite 19 before the elastic expression processing. . As a result, the constituent fibers of the sheet 12 are plastically deformed and stretched to make the fibers thinner. At the same time, the sheet 12 becomes more bulky, has a good touch, and has a good cushioning property.

  The stretchable sheet 10 thus obtained is stretched 50% along the direction in which the elastic filament 13 extends, and a load A (hereinafter also referred to as 25% return strength) when 25% is returned from that state, is elastic. It is sufficient that the ratio (A / B) to the load B (hereinafter also referred to as 50% strength) when stretched 25% along the extending direction of the filament 13 is 50% or more, particularly 65% or more. It is preferable from the viewpoint of the development of various stretch properties.

Further, although depending on the specific application, the stretch sheet 10 preferably has an overall basis weight of 10 to 150 g / m ² , particularly 25 to 60 g / m ² . Regarding the thickness of the stretchable sheet 10, it is preferably 0.05 to 5 mm, particularly preferably 0.5 to 2 mm. When the basis weight and thickness are in this range, when the stretchable sheet 10 is used as a constituent material of the absorbent article, for example, the absorbent article is thin and light, which is preferable. The thickness of the stretchable sheet 10 is measured by the same method as the measurement of the thickness of the extensible sheets 11 and 12 described above.

  The stretchable sheet 10 of the present embodiment is used for various applications depending on the type of the functional material 30 and the types of the extensible sheets 11 and 12. For example, when the functional material 30 is made of a highly absorbent polymer, the sheet 11 is made of a highly moisture permeable sheet, and the sheet 12 is made of a highly stretched hydrophilic nonwoven fabric, the stretchable sheet 10 can be used as a stretchable absorbent body. When the functional material 30 is composed of a deodorant, a fragrance, a disinfectant or antibacterial agent, a cleaning agent, and a poultice, and the sheets 11 and 12 are composed of a highly stretched water-repellent nonwoven fabric, the stretchable sheet 10 is deodorized. It can be used as an aromatic sheet, a sterilization or antibacterial sheet, a cleaning sheet, and a poultice sheet. When the functional material 30 is made of a heating element, the sheet 11 is made of a moisture permeable film, and the sheet 12 is made of a highly stretched water-repellent nonwoven fabric, the stretchable sheet 10 can be used as a stretchable thermal sheet.

  Next, a second embodiment of the present invention will be described with reference to FIG. Regarding the points that are not particularly described with respect to these embodiments, the above-described description with respect to the first embodiment is appropriately applied. In FIG. 7, the same members as those in FIG.

  The stretchable sheet 10 shown in FIG. 7 uses an elastic band 13A made of a flat film instead of the elastic filament 13 in the stretchable sheet of the first embodiment. In the figure, functional materials are not shown for simplicity. In the present embodiment, the functional material is sandwiched between portions where the sheet 11 and the sheet 12 directly face each other.

  The elastic strip 13A is elastic and has or does not have moisture permeability. When the elastic strip 13A has moisture permeability, it is preferable that at least one of the extensible sheets 11 and 12 also has moisture permeability. Examples of the elastic band-like body 13A having moisture permeability include a non-porous moisture-permeable elastic film made of a block copolymer polyester resin made of a hard component and a soft component (see Japanese Patent Application Laid-Open No. 2004-307771). Further, for example, non-porous materials described in JP-A-7-70936, JP-A-6-134000, JP-B-6-67604, JP-A-1-141669, JP-B-5210104, etc. A moisture-permeable urethane-based elastomer or Soflan palm (trade name) manufactured by Toyo Tire & Rubber Co., Ltd. can be used. Furthermore, for example, non-porous moisture-permeable ester elastomers described in JP-A No. 51-111290 and Frekuma (trade name) manufactured by Nippon Synthetic Chemical Co., Ltd. can be used.

When the elastic band 13A has moisture permeability, the moisture permeability (measured at 30 ° C. and 90% RH according to JIS Z0208) is 0.1 to 6 g / (100 cm ² · hr), particularly 0.2 to 4 g. / (100 cm ² · hr) is preferable. In addition, the elastic strip 13A preferably has an elongation before joining of 50 to 800%, particularly 100 to 800%, from the viewpoint of obtaining a stretchable sheet 10 having sufficient stretchability. The elongation of the elastic strip 13A is as follows: measurement environment temperature / humidity 20 ± 2 ° C., 65 ± 5% RH, test piece width 10 mm, gripping interval of the tensile tester 25 mm, tensile speed of the test piece in the stretching direction of the elastic strip 13A The measurement is performed under the condition of 20 mm / min. The load at the maximum point at that time was defined as the maximum strength, and the elongation at the maximum point was determined. Preferably, it is measured using a tensile tester AG-1kNIS manufactured by Shimadzu Corporation. The basis weight of the elastic strip 13A itself is preferably 3 to 100 g / m ² , particularly preferably 5 to ²⁰ g / m ² .

  Each elastic strip 13A has a substantially constant width in the extending direction. This width can be appropriately determined according to the specific application of the stretchable sheet 10. The width of the stretchable sheet 10 is preferably 2 to 40 mm, particularly 3 to 10 mm. The width of each elastic strip 13 </ b> A may be the same or different depending on the specific application of the stretchable sheet 10.

  Each elastic strip 13A is separated in the direction orthogonal to the extending direction, and the extensible sheets 11 and 12 are in direct contact with each other between the adjacent elastic strips 13A. Alternatively, the elastic strip 13A may be one in which one or two or more through holes are formed, and the sheet 11 and the sheet 12 may be directly formed at the positions of the through holes. In any case, the pitch P between the adjacent elastic strips 13A can be appropriately determined according to the specific application of the stretchable sheet 10. For example, when the stretchable sheet 10 is used as an absorbent body of an absorbent article, the pitch P is preferably 1.5 to 100 mm, particularly 2 to 20 mm. The pitch P may be the same or different depending on the specific application of the stretchable sheet 10.

  The stretchable sheet 10 of this embodiment can be manufactured by extruding an elastic resin from the spinning head 17 in the form of a belt in the apparatus shown in FIG. 4 used in the first embodiment.

  According to this embodiment, although it is inferior in terms of air permeability and the like, there is an advantage that the design is excellent because the elastic band has a stripe pattern.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, in the embodiment shown in FIG. 1, all the elastic filaments 13 have the same diameter and are arranged at an equal pitch. Therefore, the elongation stress is the same regardless of the portion of the stretchable sheet 10. However, instead of this, the stretchable sheet may be configured to be composed of two or more regions having different extension stresses in the extension direction of the elastic filament. Two or more of the regions are arranged substantially in parallel with the extending direction. In this case, the pitches of the adjacent elastic filaments are different and / or the diameters of the elastic filaments are different between the regions having different elongation stresses. Thereby, the elongation stress can be made different between the regions. Even when two or more kinds of different resins are introduced into an arbitrary spinning nozzle and spun during the production of the stretchable sheet, the elongation stress can be made different between the regions.

  In each of the above embodiments, the stretchable sheet 10 can be partially embossed, or the elastic filament 13 can be partially cut or partially heat sealed. These operations are performed for the purpose of forming a non-expandable portion in the stretchable sheet 10 or partially increasing the strength. Alternatively, it is performed for the purpose of bonding with other members or providing design.

  Moreover, regarding the elastic expression processing using the elastic expression processing device 22, the elastic expression processing direction is not limited to the flow direction of the extensible sheets 11 and 12 but may be, for example, an oblique direction. Furthermore, it is possible to combine two or more kinds of elastic expression treatment methods, increase the draw ratio stepwise, or partially perform the elastic expression treatment. The elastic development processing direction may be not only one direction but also two orthogonal directions.

  Moreover, in the manufacturing method of the said embodiment, although the elastic expression processing apparatus provided with a pair of tooth space roll 20 and 21 was used for the elastic expression processing, it replaced with using the elastic expression processing apparatus provided with the tenter. Elasticity treatment processing may be performed.

The elastic sheet 10 of this embodiment is suitably used as an absorbent body for various absorbent articles such as disposable diapers and sanitary napkins. It is also suitable for an integral absorbent body (including a pad) having a leak-proof function such as a moisture permeable back sheet. In addition to these applications, various uses such as medical disposable absorbents, cleaning sheets, thermal sheets, eye bands, masks, bandages, etc., taking advantage of its good texture, fuzz prevention, stretchability, breathability, etc. It can also be used. When used as a constituent material of absorbent articles such as sanitary napkins and disposable diapers, in addition to the absorber, for example, a liquid-permeable sheet (including a surface sheet, sublayer, etc.) located on the skin side of the absorber ), A sheet constituting the outer surface of the disposable diaper, a sheet for imparting elastic stretchability to the waist part, waist part, leg part and the like. It can also be used as a sheet or the like for forming a napkin wing. Moreover, even if it is another site | part, it can be used for the site | part etc. which want to provide a stretching property. The basis weight and thickness of the stretchable sheet 10 can be appropriately adjusted according to the specific application. For example, when used as a constituent material of an absorbent article, it is desirable that the basis weight is about ²⁰ to 200 g / m ² and the thickness is about 0.5 to 2.5 mm.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples.

[Example 1]
The stretchable sheet 10 having the structure shown in FIGS. 1 and 2 was manufactured using the apparatus shown in FIG. A hydrophilic air-through nonwoven fabric comprising a core-sheath type composite fiber (core: PET, sheath: PE) having a basis weight of 20 g / m ² , a fiber diameter of 19 μm and a fiber length of 44 mm as the extensible sheets 11 and 12 and having a maximum elongation of 170%. Was used. An elastomer made of SEPS resin (weight average molecular weight 50,000, MFR 60 g / 10 min (230 ° C., 2.16 kg) (JIS K7210: 1999)) was used as the raw resin for the elastic filament 13. The spinning conditions for the elastic filament 13 were as follows: The temperature of the spinning head 17 was 310 ° C., the diameter of the spinning nozzle 16 was 400 μm, and the pitch of the spinning nozzle 16 was 1.5 mm.The diameter of the elastic filament 13 was 145 μm The apparent basis weight of the filament (the filament weight in the stretchable sheet 10) / Area of the stretchable sheet 10) was 10 g / m ² , and the draw ratio was 9.6 times, the draw ratio being defined by (nozzle hole diameter / fiber diameter before stretch expression treatment) ² . Prior to fusing to the extensible sheets 11, 12, an adhesive is sprayed on the upper surface of the sheet 12. The coating amount was about 4 g / m ^2, and the average basis weight of the superabsorbent polymer (manufactured by Sundia, IM-930) was about 30 g / m ² using a shaking sieve. A metal roll and a rubber roll were used as the nip rolls 18 and 18. The rubber roll was disposed so as to contact the sheet 11, and the metal roll was disposed so as to contact the sheet 12. By these rolls, The elastic filament 13 was fused between the extensible sheets 11 and 12, and a superabsorbent polymer was sandwiched between the extensible sheets 11 and 12. Thus, a composite 19 was obtained.

The elastic expression processing of the composite 19 was performed using an elastic expression processing device 22 provided with a pair of tooth space rolls 20 and 21 in which teeth and roots were alternately formed in the axial length direction. The pitch between teeth and the bottom of each tooth was 2.0 mm (the pitch P between teeth in the meshed state was 1.0 mm). The amount of pressing of the upper and lower tooth gap rolls was adjusted, and the composite 19 was elastically treated in the extending direction of the elastic filaments 13 using the original roll at a draw ratio of 2.0 times. Thereby, the elastic sheet 10 having a basis weight of 76 g / m ² that expands and contracts in the extending direction of the elastic filament 13 was obtained. The obtained stretchable sheet showed good stretchability and good absorption performance.

[Example 2]
In Example 1, as the extensible sheet 11, an unstretched moisture permeable film having a basis weight of 40 g / m ² and containing calcium carbonate and polyethylene was used. Except for this, the stretchable sheet 10 was obtained in the same manner as in Example 1. The obtained stretchable sheet showed good stretchability and good absorption performance.

FIG. 1 is a partially broken perspective view showing a first embodiment of the stretchable sheet of the present invention. 2A and 2B are longitudinal sectional views in a natural state and an extended state, respectively, along the extending direction of the elastic filament in the stretchable sheet shown in FIG. FIG. 3 is an SEM image showing an example of an inelastic fiber in which the diameter (cross-sectional area) of the fiber is changed in a substantially step shape. FIG. 4 is a schematic view showing an apparatus suitably used for manufacturing the stretchable sheet shown in FIG. FIG. 5 is a schematic view showing a state in which the composite is subjected to an elastic expression treatment by the apparatus shown in FIG. FIG. 6 is a schematic diagram showing a state where the non-elastic fiber is subjected to an elastic expression process. FIG. 7 is a partially broken perspective view (corresponding to FIG. 1) showing a second embodiment of the stretchable sheet of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Elastic sheet 11 1st stretchable non-stretch sheet 12 2nd stretchable non-stretch sheet 13 Elastic filament 13A Elastic strip 14 High basic weight area | region 14 'Top part 14 "Valley part 15 Low basic weight area | region 15 '' Ridge line

Claims (5)

A plurality of elastic filaments or elastic strips arranged so as to extend in one direction without crossing each other, in a substantially non-stretched state, over their entire length, a first stretchable non-stretchable sheet, and a second A stretchable sheet joined between the stretchable non-stretchable sheet and a high absorption between the first stretchable non-stretchable sheet and the second stretchable non-stretchable sheet. A functional material composed of a conductive polymer particle is sandwiched, and there is no other elastic filament or elastic band bonded in a state orthogonal to the elastic filament or the elastic band. absorption gender sheet, and raised between the two said elastic filaments or the elastic strip of the adjacent forming said plurality of ridges extending in the same direction as the direction of extension of the elastic filaments or the elastic strip Stretchable sheet of the article. The stretchable sheet for absorbent articles according to claim 1, wherein at least one of the first and second stretchable non-stretchable sheets is a nonwoven fabric. The stretchable sheet for absorbent articles according to claim 1 or 2, wherein at least one of the first and second stretchable non-stretchable sheets is a moisture-permeable sheet. A composite body in which a large number of elastic filaments or elastic strips are sandwiched between the stretchable non-stretchable sheets in a substantially non-extended state, along the direction in which the elastic filaments or elastic strips extend. It is manufactured by developing elasticity,
The process of developing elasticity is a biting extension in which the complex is bitten between the tooth gap rolls in an elastic expression processing apparatus including a pair of tooth gap rolls in which teeth and roots are alternately formed in the circumferential direction. The elastic sheet for absorbent articles according to any one of claims 1 to 3 . The absorbent article provided with the elastic sheet for absorbent articles in any one of Claims 1 thru | or 4 .