AND HYGIENIC MATERIAL

BACKGROUND

The present invention relates to an elastic laminate sheet, a tab member, or a hygienic material provided with a tab member.

It is known that an elastic laminate sheet in which a nonwoven fabric is laminated on an elastomer layer is known (see, e.g. JP 5600275 B and JP 5231001 B). For example, in paragraph“0011” of JP 5600275 B, it is described that“an elastic laminate sheet 1 includes a low elasticity laminate sheet Al and a high elasticity laminate sheet A2 constituting the laminate body, and the low elasticity laminate sheet Al and the high elasticity laminate sheet A2 are alternately arranged in one direction”. Furthermore, in paragraph“0012” thereof, it is described that“in the low elasticity laminate sheet Al and the high elasticity laminate sheet A2, there are first bonding regions 5a and 6a in which an elastomer layer 3 and a nonwoven fabric 2 are bonded, and there are second bonding regions 5b and 6b in which the elastomer layer 3 and the nonwoven fabric 2 are bonded in a weaker bonding manner than that of the first bonding regions 5a and 6a". In addition, in paragraph“0037”, it is described that“a longitudinal direction of the band-shaped first bonding region 6a intersects with an MD, and it is preferable for an angle formed between the longest axis among symmetry axes of the band-shaped first bonding region 6a and the alignment direction (MD) of the band-shaped high elasticity laminate sheet A2 and the low elasticity laminate sheet Al to be greater than 0° and equal to or smaller than 90°, and more preferable to be equal to or greater than 10° and equal to or smaller than 90°”.

SUMMARY OF INVENTION

When a hygienic material such as an open type disposable diaper is put on a wearer, a tab portion of the hygienic material is pulled and fixed while adjusting the tightening force. In a case where the elastic laminate sheet described above is applied to the tab portion, when the elasticity is prioritized, the peeling strength between the elastomer layer and the nonwoven fabric is likely to be lowered, and thus it is difficult to improve both the elasticity and the peeling strength. An elastic laminate sheet according to an aspect of the present invention includes an elastic film, a nonwoven fabric laminated on at least one surface of the elastic film, and a pressure bonding line where the nonwoven fabric and the elastic film are pressure-bonded and recessed. The pressure bonding line extends in one direction diagonally intersecting with an elastic direction of the elastic film, a plurality of pressure bonding lines is provided side by side in a lateral direction orthogonal to the one direction, and an inclination angle of the one direction with respect to the elastic direction is equal to or larger than 15° and equal to or smaller than 75°.

In a case where a region in which the nonwoven fabric and the elastic film are pressure-bonded is enlarged, the peeling strength is improved, but the elasticity of the elastic film may be lowered. The elastic laminate sheet described above is provided with the pressure bonding lines extending in the one direction; the one direction, which is an extending direction of the pressure bonding line, is inclined with respect to the elastic direction, and in particular, the inclination angle is equal to or larger than 15° and equal to or smaller than 75°. Therefore, the elasticity is unlikely to be lowered compared to a mode in which the pressure bonding line is formed along the elastic direction. As a result, it is advantageous to have the above-discussed configuration in a sense that the peeling strength between the elastic film and the nonwoven fabric is enhanced while maintaining adequate elasticity.

A tab member according to an aspect of the present invention includes an elastic laminate sheet provided with an elastic film and a nonwoven fabric laminated on at least one surface of the elastic film, and an engaging portion that is one of a pair of engaging portions forming a mechanical fastener and is fixed to the elastic laminate sheet. An elastic region of the elastic laminate sheet includes a pressure bonding line where the nonwoven fabric and the elastic film are pressure-bonded and recessed. The pressure bonding line extends in one direction diagonally intersecting with an elastic direction of the elastic film. A plurality of pressure bonding lines is provided side by side in a lateral direction orthogonal to the one direction. An inclination angle of the one direction with respect to the elastic direction is equal to or larger than 15° and equal to or smaller than 75°. The engaging portion is provided at one end portion of both end portions in the elastic direction of the elastic laminate sheet.

A hygienic material according to an aspect of the present invention is a hygienic material including a tab portion provided with one engaging portion of a pair of engaging portions forming a mechanical fastener, and a main body provided with the other engaging portion. The tab portion includes an elastic laminate sheet provided with an elastic film and a nonwoven fabric laminated on at least one surface of the elastic film, and the one engaging portion fixed to the elastic laminate sheet. An elastic region of the elastic laminate sheet includes a pressure bonding line where the nonwoven fabric and the elastic film are pressure-bonded and recessed. The pressure bonding line extends in one direction diagonally intersecting with an elastic direction of the elastic film. A plurality of pressure bonding lines is provided side by side in a lateral direction orthogonal to the one direction. An inclination angle of the one direction with respect to the elastic direction is equal to or larger than 15° and equal to or smaller than 75°. The engaging portion is provided at one end portion of both end portions in the elastic direction of the elastic laminate sheet.

According to an aspect of the present invention, it is advantageous to have the above-discussed configuration in a sense that the peeling strength between the elastic film and the nonwoven fabric is enhanced while maintaining adequate elasticity.

BRIEF DESCRIPTION OF DRAWINGS

FIG. l is a perspective view of an elastic laminate sheet according to a first embodiment.

FIG. 2 is an enlarged plan view illustrating a region indicated by an arrow A in

FIG. 1.

FIG. 3 is a cross-sectional view taken along a line III-III in FIG. 2.

FIG. 4 is an enlarged plan view illustrating a modification of the elastic laminate sheet according to the first embodiment.

FIG. 5 is a diagram schematically illustrating a manufacturing process of an elastic laminate sheet.

FIG. 6 is a plan view illustrating a tab member with part thereof torn off.

FIG. 7 is a perspective view illustrating a disposable diaper as an example of a hygienic material in a state prior to being fixed with a tab portion.

FIG. 8 is a perspective view illustrating a disposable diaper as an example of a hygienic material in a state after being fixed with a tab portion.

FIG. 9 is an enlarged plan view of an elastic laminate sheet according to a second embodiment. FIG. 10 is an enlarged plan view of an elastic laminate sheet according to a third embodiment.

FIG. 11 is an enlarged plan view of an elastic laminate sheet according to a fourth embodiment.

FIG. 12A is a front view illustrating an example of an elastic film fixed with a sealing material to make a 100% extension. FIG. 12B is a front view illustrating an example of an elastic film which has been once extended and is currently fixed again with a sheet material to make a second 100% extension.

FIG. 13 A is a cross-sectional view of an elastic film in a fixed state, FIG. 13B is a cross-sectional view thereof in a 100% extended state, and FIG. 13C is a

cross-sectional view thereof having been returned to the original state.

FIG. 14A is a cross-sectional view of an elastic film which has been once extended and is currently in a fixed state, FIG. 14B is a cross-sectional view thereof in a 100% extended state, and FIG. 14C is a cross-sectional view thereof having been returned to the original state by 50%.

FIG. 15 is a perspective view illustrating an example of a jig for expanding and contracting an elastic laminate sheet prior to measuring peeling strength.

FIG. 16A is a front view illustrating an example of a method for measuring peeling strength of an elastic laminate sheet, and FIG. 16B is a cross-sectional view of the front view cut along a line b-b.

DETAILED DESCRIPTION OF EMBODIMENTS

An elastic laminate sheet according to an aspect of an embodiment includes an elastic film, a nonwoven fabric laminated on at least one surface of the elastic film, and a pressure bonding line where the nonwoven fabric and the elastic film are

pressure-bonded and recessed. The pressure bonding line extends in one direction diagonally intersecting with an elastic direction of the elastic film, a plurality of pressure bonding lines is provided side by side in a lateral direction orthogonal to the one direction, and an inclination angle of the one direction with respect to the elastic direction is equal to or larger than 15° and equal to or smaller than 75°.

In a case where a region in which the nonwoven fabric and the elastic film are pressure-bonded is enlarged, the peeling strength is improved, but the elasticity of the elastic film may be lowered. The elastic laminate sheet described above is provided with the pressure bonding lines extending in the one direction; the one direction, which is an extending direction of the pressure bonding line, is inclined with respect to the elastic direction, and in particular, the inclination angle is equal to or larger than 15° and equal to or smaller than 75°. Therefore, the elasticity is unlikely to be lowered as compared with a mode in which the pressure bonding line is formed along the elastic direction. As a result, it is advantageous to have the above-discussed configuration in a sense that the peeling strength between the elastic film and the nonwoven fabric is enhanced while maintaining adequate elasticity.

In the aforementioned elastic laminate sheet, the pressure bonding line is formed in such a manner that a plurality of pressure bonding portions in each of which the nonwoven fabric and the elastic film are pressure-bonded and recessed is arranged being aligned in the one direction, and the pressure bonding portion may be formed longer in the one direction than in the lateral direction. As described above, a single pressure bonding line is provided being divided into a plurality of pressure bonding portions, which is an advantageous scheme to improve the elasticity.

In the aforementioned elastic laminate sheet, a plurality of auxiliary pressure bonding portions in each of which the nonwoven fabric and the elastic film are pressure-bonded and recessed is provided between the plurality of pressure bonding lines, and a width in an elastic direction of the auxiliary pressure bonding portion may be formed smaller than a width in the elastic direction of the pressure bonding line. Since the width in the elastic direction of the auxiliary pressure bonding portion is smaller than the width in the elastic direction of the pressure bonding line, the reduction in elasticity is small. On the other hand, it is advantageous to provide the above auxiliary pressure bonding portions in improving the peeling strength between the elastic film and the nonwoven fabric.

In at least part of a non-pressure bonding portion where the nonwoven fabric and the elastic film of the elastic laminate sheet are not pressure-bonded, the nonwoven fabric may be so formed as to be buried in the elastic film. The nonwoven fabric is buried in the elastic film not only in the pressure bonding line but also in the non-pressure bonding portion, which is advantageous in improving the peeling strength between the elastic film and the nonwoven fabric.

In the aforementioned elastic laminate sheet, among the plurality of pressure bonding lines, the plurality of pressure bonding portions in one of adjacent pressure bonding lines may be so arranged as to be aligned in the lateral direction with respect to the plurality of pressure bonding portions in the other one of the adjacent pressure bonding lines.

In the aforementioned elastic laminate sheet, among the plurality of pressure bonding lines, the plurality of pressure bonding portions in one of adjacent pressure bonding lines may be so arranged as to be shifted from the lateral direction with respect to the plurality of pressure bonding portions in the other one of the adjacent pressure bonding lines.

In the elastic laminate sheet described above, under the conditions of a temperature of 23 ± 2°C and humidity of 50 ± 5%, a 75% extension is performed at a rate of 300 mm/minute on the elastic film with the nonwoven fabric peeled off, thereafter, at a rate of 300 mm/minute, the elastic laminate sheet is returned to the initial position before the extension, and then a load may be equal to or less than 2.5 N/25 mm when a 50% extension is further performed at a rate of 300 mm/minute. This load is advantageous in maintaining the elasticity when applied to a tab portion of a hygienic material such as an adult diaper.

The above-discussed load in the elastic laminate sheet described above may be set to a mode of less than 1.6 N/25 mm. It is advantageous to set this load in maintaining the elasticity when applied to a tab portion of a hygienic material such as an infant diaper.

In the elastic laminate sheet described above, under the conditions of a temperature of 23 ± 2°C and humidity of 50 ± 5%, a peeling test is performed in which the elastic film and the nonwoven fabric are peeled at a peel rate of 500 mm/minute along a peeling direction as a direction opposite to both the elastic film and the nonwoven fabric, and then an integral average of a plurality of adhesive strengths obtained during the peeling may be equal to or larger than 3.5 N/15 mm. This mode brings an advantage in improving the peeling strength.

A tab member according to an aspect of the embodiment includes an elastic laminate sheet provided with an elastic film and a nonwoven fabric laminated on at least one surface of the elastic film, and an engaging portion that is one of a pair of engaging portions forming a mechanical fastener and is fixed to the elastic laminate sheet. An elastic region of the elastic laminate sheet includes a pressure bonding line where the nonwoven fabric and the elastic film are pressure-bonded and recessed. The pressure bonding line extends in one direction diagonally intersecting with an elastic direction of the elastic film. A plurality of pressure bonding lines is provided side by side in a lateral direction orthogonal to the one direction. An inclination angle of the one direction with respect to the elastic direction is equal to or larger than 15° and equal to or smaller than 75°. The engaging portion is provided at one end portion of both end portions in the elastic direction of the elastic laminate sheet.

This tab member brings an advantage in improving the peeling strength between the elastic film and the nonwoven fabric while maintaining adequate elasticity.

In the tab member described above, the elastic laminate sheet further includes an elasticity-restricting region in at least one of two regions sandwiching the elastic region in the elastic direction; the elasticity-restricting region includes one or a plurality of restrictive pressure bonding portions in each of which the nonwoven fabric and the elastic film are pressure-bonded and recessed, and a length in an elastic direction of the restrictive pressure bonding portion may be configured to be longer than a lateral width of the pressure bonding line. In the restrictive pressure bonding portion, elasticity is suppressed, and therefore, for example, the stated portion is suitable to be used as a portion to provide therein the engaging portion or to be fixed to another member.

A hygienic material according to an aspect of the embodiment is a hygienic material including a tab portion provided with one engaging portion of a pair of engaging portions forming a mechanical fastener, and a main body provided with the other engaging portion. The tab portion includes an elastic laminate sheet provided with an elastic film and a nonwoven fabric laminated on at least one surface of the elastic film, and the one engaging portion fixed to the elastic laminate sheet. An elastic region of the elastic laminate sheet includes a pressure bonding line where the nonwoven fabric and the elastic film are pressure-bonded and recessed. The pressure bonding line extends in one direction diagonally intersecting with an elastic direction of the elastic film. A plurality of pressure bonding lines is provided side by side in a lateral direction orthogonal to the one direction. An inclination angle of the one direction with respect to the elastic direction is equal to or larger than 15° and equal to or smaller than 75°. The engaging portion is provided at one end portion of both end portions in the elastic direction of the elastic laminate sheet.

This tab portion of the hygienic material is advantageous for improving the peeling strength between the elastic film and the nonwoven fabric while maintaining adequate elasticity.

Of the terms used in the above modes,“film” refers broadly to the form of a sheet shape, a band shape (tape shape), or the like. The expression“pressure-bonded and recessed” refers to a state in which constituent elements are fixed in a partially compressed state and has a reduced thickness as compared with a thickness of a non-pressure bonding portion, which is not compressed. The pressure bonding line includes at least both a mode in which a single line is formed by a plurality of pressure bonding portions being aligned in a row, and a mode in which a single line is formed by a single pressure bonding portion extending in the form of a line.“Elastic direction of the elastic film” refers to the direction in which the elasticity is substantially the highest.“Inclination angle in one direction with respect to the elastic direction” refers to the smaller angle of the angles of intersection formed between the direction diagonally intersecting with the elastic direction and the elastic direction.

Detailed descriptions of the embodiments will be given below with reference to the attached drawings. Note that identical constituent elements are assigned identical reference signs in the explanation of the drawings, and duplicate explanation is omitted.

Elastic laminate sheets according to the embodiments may be suitably used in applications requiring excellent elasticity such as in diaper applications, may be suitably used in applications requiring high aesthetics, and may also be suitably used in applications requiring a nice feel (soft texture or the like).

As illustrated in FIGS. 1 to 3, an elastic laminate sheet 1 A according to a first embodiment is a sheet material in which nonwoven fabrics 3 and 4 are laminated on both surfaces of an elastic film 2. A direction in which the elastic film 2 is fed in a state of the nonwoven fabrics 3 and 4 being laminated thereon is referred to as a machine direction (MD), and a direction orthogonal to the MD is referred to as a cross machine direction (CD). In the present embodiment, the elasticity in the CD is higher than that in the MD, and the CD is referred to as an elastic direction Dl . In the present embodiment, a mode in which the nonwoven fabrics 3 and 4 are laminated on both the sides of the elastic film 2 is described as an example, but the mode may be such that the nonwoven fabric 3 is laminated on only one surface thereof.

The elastic laminate sheet 1 A includes an elastic region AR1 and an elasticity-restricting region AR2. The elasticity-restricting region AR2 refers to a region having low elasticity as compared with the elastic region ART . The elastic region ART and the elasticity-restricting region AR2 are respectively provided with pressure bonding portions 5 and 6 in each of which the nonwoven fabric 3 and the elastic film 2 are pressure-bonded and recessed. The pressure bonding portions 5 and 6 are formed by embossing using a nip roll having a predetermined concave-convex pattern on the surface thereof. Basically, the larger an area occupied by the pressure bonding portion 5 and 6, the lower the elasticity becomes, and it is possible to distinguish the elastic region AR1 and the elasticity -restricting region AR2 from each other in accordance with the forms of the pressure bonding portions 5 and 6. Note that in the elasticity-restricting region AR2, the concave-convex pattern of the pressure bonding portion 6 may not be particularly provided, and the pressure bonding may be made across the whole region. Furthermore, in the present embodiment, the pressure bonding portions 5 and 6 (see FIG. 6) are formed on the nonwoven fabric 3 side as one side among the nonwoven fabrics 3 and 4 laminated on both the surfaces of the elastic film 2; however, pressure bonding portions similar to the pressure bonding portions 5 and 6 may be provided on both the surface sides. Hereinafter, description will be given mainly focusing on the elastic region AR1.

The elastic film 2 and the nonwoven fabrics 3 and 4 are uniformly bonded (fixed) over the entire surface, and are particularly firmly bonded to each other in the pressure bonding portion 5. Specifically, the nonwoven fabrics 3 and 4 are buried in the elastic film 2 at part of the laminate surfaces 3 a and 4a in contact with the elastic film 2, and are buried deeper in the pressure bonding portion 5 than in a portion (non-pressure bonding portion) 7 other than the pressure bonding portion 5. Note that the phrase, the nonwoven fabrics 3 and 4 are buried in the elastic film 2, refers to a state in which at least part of the nonwoven fabrics 3 and 4 directly enters the elastic film 2 to be integrated without using an adhesive or the like.

A plurality of pressure bonding portions 5 is provided in the elastic region AR1. The plurality of pressure bonding portions 5 is aligned in one direction D2 diagonally intersecting with the elastic direction Dl, and a pressure bonding line 8 is formed by the plurality of pressure bonding portions 5 aligned in the one direction D2. In other words, the one direction D2 in which the plurality of pressure bonding portions 5 is aligned is an extension direction of the pressure bonding line 8. The one direction D2 is provided being inclined with respect to the elastic direction Dl of the elastic film 2.

In the pressure bonding portion 5, a length La in the one direction D2 is longer than a width Wa in a lateral direction D3 orthogonal to the one direction D2. In other words, it is sufficient that the pressure bonding portion 5 can identify a long shape elongated in the one direction D2, and it may have an oval shape, a rectangular shape, or other shapes, for example. The length La in the longitudinal direction of the pressure bonding portion 5 may be set to 0.3 mm to 4.0 mm, 0.5 mm to 3.0 mm, or 0.7 mm to 2.0 mm. The width Wa in the lateral direction D3 orthogonal to the longitudinal direction of the pressure bonding portion 5 may be set to 0.1 mm to 3.0 mm, 0.2 mm to 2.0 mm, or 0.3 mm to 1.0 mm. A depth da being recessed as the pressure bonding portion 5 may be set to 0.1 mm to 5.0 mm, 0.2 mm to 2.0 mm, or 0.3 mm to 1.0 mm. The depth da being recessed as the pressure bonding portion 5 refers to a distance between a surface 7a of a non-pressure bonding portion 7 that is not pressure-bonded and a bottom 5a of the pressure bonding portion 5. A thickness db of the elastic laminate sheet 1 A may be set to 0.3 mm to 6.0 mm, 0.5 mm to 4.0 mm, or 1.0 mm to 3.0 mm.

Here,“one direction D2 diagonally intersecting with the elastic direction Dl” refers neither to a direction along the elastic direction Dl, nor to a direction along the direction orthogonal to the elastic direction Dl . Specifically, an inclination angle Q of the one direction D2 diagonally intersecting with the elastic direction Dl may be equal to or larger than 15°, may be equal to or larger than 22.5°, or may be equal to or larger than 45°. Furthermore, the inclination angle Q may be equal to or smaller than 75°, may be equal to or smaller than 67.5°, or may be equal to or smaller than 45°. Moreover, the inclination angle Q is 15° to 75°, preferably it is 22.5° to 67.5°, and more preferably it is 40° to 50°.

The elastic laminate sheet 1 A includes a plurality of pressure bonding lines 8 extending in the one direction D2. Specifically, the plurality of pressure bonding lines 8 is so provided as to be aligned in parallel in the lateral direction D3 orthogonal to the one direction D2.

When identifying the pressure bonding line 8, for example, the pressure bonding line 8 can be determined based on any one of the pressure bonding portions 5. Specifically, the longitudinal direction of the pressure bonding portion 5 to be a reference is identified, and then a straight line that extends along the longitudinal direction passing through the reference pressure bonding portion 5 is assumed. Next, if the longitudinal direction of the pressure bonding portion 5 along the above straight line is substantially aligned with this straight line, it is possible to confirm that the pressure bonding line 8 is formed by the plurality of pressure bonding portions 5 arranged on the straight line. A situation that the longitudinal direction of the pressure bonding portion 5 is substantially aligned with the straight line refers to a case where, for example, the longitudinal direction is allowed to have an inclination of approximately several degrees toward a left or right side with respect to the straight line.

Next, two adjacent pressure bonding lines 8 are compared. In the present embodiment, with respect to the plurality of pressure bonding portions 5 forming one pressure bonding line 8, the plurality of pressure bonding portions 5 forming the other pressure bonding line 8 is aligned in the lateral direction D3. In contrast, as illustrated in FIG. 4, for example, a modification may be employed in which, with respect to a plurality of pressure bonding portions 5X forming one pressure bonding line 8, the plurality of pressure bonding portions 5X forming the other pressure bonding line 8 is disposed being shifted from the lateral direction D3 (staggered arrangement).

The elastic film 2 may be formed with a resin material including an elastomer. The type of elastomer is not particularly limited, and examples include

styrene-isoprene- styrene block copolymer (SIS), styrene-butadiene- styrene block copolymer (SB S), styrene-ethylene/butylene-styrene block copolymer

(SEBS), polyurethane, ethylene copolymer (for example, ethylene-vinyl acetate, ethylene-propylene copolymer, ethylene-propylene-diene terpolymer), propylene oxide (PO), and the like. In view of the convenience in the manufacturing process, a multilayer structure having a skin such as polyolefin on at least one surface of the core of the elastomer may be used.

The resin material forming the elastic film 2 may contain other ingredients than the aforementioned ingredients. For example, the resin material may also contain a stiffening agent (for example, polyvinyl styrene, polystyrene, polya-methyl styrene, polyester, epoxy resin, polyolefin, coumarone-indene resin), viscosity reducing agent, plasticizer, tackifier (for example, an aliphatic hydrocarbon tackifier, an aromatic hydrocarbon tackifier, a terpene resin tackifier, a hydrogenated terpene resin tackifier), dye, pigment, antioxidant, antistatic agent, adhesive, antiblocking agent, slip agent, thermal stabilizer, light stabilizer, blowing agent, glass bubbles, starch, metal salt, microfibers, and the like.

The nonwoven fabrics 3 and 4 can widely take materials that can be processed into fibers, and can be prepared to have desired softness by appropriately combining the materials, adjusting fiber lengths and thicknesses, and the like. The material of the nonwoven fabrics 3 and 4 may be, for example, polypropylene fibers, mixed fibers formed by blending polyester fibers and polyolefin fibers, or concentric-type composite fibers formed of a core material of polyethylene terephthalate and polyethylene covering the stated core material. The manufacturing method for the nonwoven fabrics 3 and 4 may be a spunbond method, a spunlace method, or a thermal bond method, for example.

Next, a manufacturing method for the elastic laminate sheet 1 A will be described. The elastic laminate sheet 1 A can be advantageously manufactured by a simultaneous melt-extrusion lamination method. In a process according to an example of the simultaneous melt-extrusion lamination method, performed are a laminate process of laminating the nonwoven fabrics 3 and 4 on the elastic film 2 to manufacture the elastic laminate sheet 1A (see FIG. 5), an activate process of subjecting the elastic laminate sheet 1 A to extension treatment, and a slitting process of forming a slit for transport in the elastic laminate sheet 1 A.

As illustrated in FIG. 5, in the laminate process, the elastic laminate sheet 1 A is manufactured by using, for example, a simultaneous melt-extrusion lamination apparatus (manufacturing apparatus) 100. The manufacturing apparatus 100 includes a nip roll 101 for forming the pressure bonding portions 5 and 6 of a predetermined pattern, and a cooling roll 102 disposed opposing the nip roll 101. Furthermore, the manufacturing apparatus 100 is connected to an extruder (not illustrated), and includes a die (typically a T-die) 103 configured to supply the elastic film 2 between the nip roll 101 and the cooling roll 102, and a nonwoven fabric supply roll (not illustrated) configured to supply a pair of nonwoven fabrics 3 and 4 to be laminated on both the sides of the elastic film 2.

The elastic film 2 is fed out from the T-die 103 in the form of a molten stream and is guided to a location between the first nonwoven fabric 3 and the second nonwoven fabric 4, which is also a location between the nip roll 101 and the cooling roll 102, and is cooled and solidified there. The cooling roll 102 can be formed from a calendering roll having a substantially smooth surface.

The nip roll 101 has a convex portion on its surface for forming the pressure bonding portions 5 and 6. The height of the convex portion can be appropriately provided corresponding to the desired depth of the pressure bonding portion 5. By nipping the elastic laminate sheet 1 A between the nip roll 101 and the cooling roll 102, the pressure bonding portions 5, 6 and the non-pressure bonding portion 7 are formed on the nonwoven fabric 3 side as one side of the elastic laminate sheet 1 A. In the pressure bonding portion 5, the nonwoven fabrics 3 and 4 are dense as compared with the non-pressure bonding portion 7, and the nonwoven fabrics 3 and 4 are firmly adhered to the elastic film 2. Although, in the non-pressure bonding portion 7, the adhesive strength between the nonwoven fabrics 3, 4 and the elastic film 2 is lower than that in the pressure bonding portion 5, they are uniformly bonded with a constant adhesive strength.

The elastic laminate sheet 1 A discharged from the nip roll 101 and the cooling roll 102 is transported to a winding roll by various transport rolls 104, and is held by the winding roll.

After the laminate process, the activate process is performed, and then the slitting process is performed. In the activate process, in order to reduce the initial strength of the nonwoven fabric and achieve low stress, the elastic laminate sheet 1 A is subjected to a constant extension treatment in the CD direction (elastic direction Dl). By performing the activate process after the laminate process, the nonwoven fabrics 3 and 4 laminated on the elastic film 2 are deformed, which also contributes to the reduction in stress of the entire elastic laminate sheet 1 A. In the present embodiment, after the slitting process, the slitting process is performed. In the slitting process, in accordance with the shape and size of the elastic laminate sheet 1 A, in general, a wide elastic laminate sheet 1 A is cut so as to have a desired width in the CD direction (elastic direction Dl).

Next, a tab member 10 used in an open type disposable diaper 20 (see FIGS. 7 and 8) will now be described with reference to FIG. 6. When the diaper 20 is put on a wearer (such as an infant, an elderly person, or the like), the diaper 20 is provided with a tab portion 21 that is pulled as if to be wrapped on the waist of the wearer. A member forming the tab portion 21 is the tab member 10.

The tab member 10 is provided with the elastic laminate sheet 1 A described above that has been processed into a predetermined shape, and an engaging portion 11 A. The elastic laminate sheet 1 A includes the elastic region AR1 and the elasticity-restricting region AR2. The elastic region ART is provided with the pressure bonding line 8 extending in the one direction D2 diagonally intersecting with the elastic direction Dl of the elastic film 2. The pressure bonding line 8 is formed by the plurality of pressure bonding portions 5 aligned in the one direction D2. The inclination angle Q of the one direction D2 with respect to the elastic direction Dl is equal to or larger than 15° and equal to or smaller than 75°. The plurality of pressure bonding lines 8 is provided side by side in the lateral direction D3 orthogonal to the one direction D2. The pressure bonding portion 5 has a shape formed to be longer in the one direction D2 than in the lateral direction D3.

It is sufficient that the elasticity-restricting region AR2 is provided in at least one of the two regions sandwiching the elastic region AR1 therebetween in the elastic direction Dl; in the present embodiment, the elasticity-restricting regions are provided in both the regions. The elasticity -restricting region AR2 includes a plurality of pressure bonding portions (restrictive pressure bonding portions) 6 in each of which the nonwoven fabrics 3 and 4 and the elastic film 2 are pressure-bonded and recessed. A length Lb in the elastic direction Dl of the restrictive pressure bonding portion 6 is longer than the width Wa in the lateral direction D3 of the pressure bonding line 8 in the elastic region AR1. The restrictive pressure bonding portion 6 according to the present embodiment is, for example, rectangular in shape, and is provided to be regularly aligned in a direction (MD) orthogonal to the elastic direction Dl . The wider the restrictive pressure bonding portion 6, the greater the resistance becomes at a time of extension so that the effect of restricting the elasticity becomes large.

The engaging portion 11 A is one of a pair of engaging portions 11 A and 11B forming a mechanical fastener 22. The mechanical fastener 22 refers to a fastener that can be attached and detached in a planar mode, broadly including a structure referred to as a surface fastener or hook and loop fastener, for example. The mechanical fastener 22 is provided with the pair of engaging portions 11 A and 11B formed in planar shapes to be in contact with each other, and on each contact surface of the pair of engaging portions 11 A and 11B, there are provided raising portions 1 la physically engaging with each other. As the raising portions 1 la engaging with each other, in addition to the relationship between hooks and loops, a case in which both elements are hooks, a case in which both hooks and loops are provided on the contact surfaces, a case of a mushroom-shaped raising portion, and the like may be cited.

The engaging portion 11 A is fixed in such a manner as to overlap with one of the two elasticity-restricting regions AR2 of the tab member 10. When the engaging portion 11 A is pulled and attached to the other engaging portion 11 A, since the engaging portion 11 A is provided in the elasticity-restricting region AR2 of the tab member 10, off-alignment due to the expansion and contraction is small so that stable attachment can be obtained.

Next, the open type disposable diaper 20 will be described with reference to FIGS. 7 and 8. The disposable diaper 20 according to the present embodiment is an example of a hygienic material. The disposable diaper 20 includes a rectangular laminate 25 having an outer liquid-impervious polymeric film 23 and an inner liquid absorbent layer 24. The tab portion 21 formed by the tab member 10 described above is provided on the laminate 25.

One of the pair of engaging portions 11 A forming the mechanical fastener 22 is provided on the tab portion 21, and the engaging portion 11B of the other one is provided on the laminate (main body) 25. The other engaging portion 11B is provided, for example, on a front surface of a region covering the hypogastrium of the wearer. When the diaper 20 is to be put on a wearer, the left and right tab portions 21 are pulled as if to wrap the polymer film 23 on the waist of the wearer. The left and right tab portions 21 are pulled with an appropriate elastic force, and eventually the engaging portion 11 A of the tab portion 21 is attached and fixed to the engaging portion 11B on the laminate 25.

The tab portion 21 is provided with the elasticity-restricting regions AR2 at two locations sandwiching the elastic region AR1; the engaging portion 11 A is fixed to one of the elasticity-restricting regions AR2, and the other elasticity -restricting region AR2 is fixed to the polymer film 23. Therefore, when the tab portion 21 is pulled to put the diaper 20 on the wearer, the tab portion 21 is not easily shifted and the shape stability is high, so that it is easy to adjust the elastic force to an appropriate level at the time of putting on the diaper. Furthermore, when the engaging portion 11 A of the tab portion 21 is attached to the other engaging portion 11B, off-alignment due to the expansion and contraction of the engaging portion 11 A is small so that stable attachment can be obtained.

Next, action effects of the elastic laminate sheet 1 A, the tab member 10, and the disposable diaper 20 (an example of the hygienic material) according to the present embodiment will be described.

If an elastic laminate sheet provided with a region in which a nonwoven fabric and an elastic film are pressure-bonded is assumed, the peeling strength improves when the pressure-bonded region is expanded, but the elasticity of the elastic film may be reduced.

Here, the elastic laminate sheet 1 A according to the present embodiment is provided with the pressure bonding line 8 extending in the one direction D2; the one direction D2, which is an extending direction of the pressure bonding line 8, is inclined with respect to the elastic direction Dl, and in particular, the inclination angle Q is equal to or larger than 15° and equal to or smaller than 75°. Therefore, the elasticity is unlikely to be lowered as compared with a mode in which the pressure bonding line 8 is formed along the elastic direction Dl . As a result, it is advantageous to have the above-discussed configuration in a sense that the peeling strength between the elastic film 2 and the nonwoven fabrics 3 and 4 is enhanced while maintaining adequate elasticity. In particular, the tab member 10 is manufactured by using the elastic laminate sheet 1 A according to the present embodiment, and the tab member 10 is used to manufacture the diaper 20. As a result, when the caregiver, parent, or the like puts the diaper 20 on the wearer, the tab 21 can be held at a predetermined position by pulling the tab 21 to the left and right evenly, not forcibly. As a result, leakage due to the off-alignment or the like of the diaper 20 may also be effectively suppressed.

Furthermore, the pressure bonding line 8 according to the present embodiment is formed by the plurality of pressure bonding portions 5. In other words, a single pressure bonding line 8 is so provided as to be separated into the plurality of pressure bonding portions 5, which is advantageous for improving the elasticity. From the perspective of the appearance and feel, it is advantageous that the single pressure bonding line 8 is formed by the plurality of pressure bonding portions 5 separated from each other, as compared with a mode in which the pressure bonding portions are continued to form a single pressure bonding line. Specifically, in the mode in which the pressure bonding portions are continued to form a single pressure bonding line, since concave portions are connected in a line shape, a concave-convex shape is easily noticeable. However, by the separation into the plurality of pressure bonding portions 5, the pressure bonding portions 5 are interspersed also on the single pressure bonding line 8. As a result, the concave-convex shape becomes less noticeable, and the feel is easily brought close to that of a normal nonwoven fabric without the pressure bonding portion 5.

In the present embodiment, the nonwoven fabrics 3 and 4 are buried in the elastic film 2 not only in the pressure bonding line 8 but also in the non-pressure bonding portion 7, which is advantageous for improving the peeling strength between the elastic film 2 and the nonwoven fabric 3.

Furthermore, the elastic laminate sheet 1 A is a laminate in which the nonwoven material 3 is laminated on the elastic film 2; the elastic laminate sheet 1 A is excellent in, in addition to the elasticity described above, texture and appearance, and can be suitably and widely used in such applications that the elastic laminate sheet 1 A directly touches the skin.

In the method for manufacturing the elastic laminate sheet 1 A according to the present embodiment, the activate process is performed after the laminate process, whereby the nonwoven fabrics 3 and 4 are deformed. As a result, the method contributes to the reduction in stress of the elastic laminate sheet 1 A. With respect to this reduction in stress, the elastic laminate sheet 1 A is provided with the pressure bonding line 8 extending in the one direction D2, which is also advantageous in maintaining and improving the peeling strength.

Furthermore, the tab member 10 according to the present embodiment is provided with the configuration of the elastic laminate sheet 1 A described above. With this, the tab member 10 is advantageous for improving the peeling strength between the elastic film 2 and the nonwoven fabric 3 while maintaining appropriate elasticity.

In addition, in the case of the diaper 20 according to the present embodiment, the elastic laminate sheet 1 A is used in the tab portion 21, which is advantageous for improving the peeling strength between the elastic film 2 and the nonwoven fabric 3 while maintaining appropriate elasticity. Specifically, the diaper 20 is easy to be worn and can be worn quickly, and the elastic laminate sheet 1 A is flexible after the wearing, so that the diaper 20 can be comfortably worn by babies, elderly persons, sick persons and the like. In addition, the attachment and detachment of the diaper 20 at the engaging portion 11 A may be repeated, and since the elastic laminate sheet 1 A has a high peeling strength, it is also strong against the repeated attachment and detachment.

Next, another embodiment of the elastic laminate sheet 1 A applicable to the diaper 20 (an example of a hygienic material) described above will be described with reference to FIG. 9, 10, or 11.

As illustrated in FIG. 9, an elastic laminate sheet 1B according to a second embodiment is further provided with an auxiliary pressure bonding portion 51 with respect to the elastic laminate sheet 1 A according to the first embodiment. Specifically, in the elastic laminate sheet 1B, a pressure bonding line 8 is formed by a plurality of pressure bonding portions 5 aligned in one direction D2, and a plurality of pressure bonding lines 8 is arranged side by side in a lateral direction D3. Further, the auxiliary pressure bonding portion 51 is provided between the adjacent pressure bonding lines 8 so as to be aligned with each pressure bonding portion 5 in the lateral direction D3. In the auxiliary pressure bonding portion 51, a nonwoven fabric 3 and an elastic film 2 are pressure-bonded and recessed, and the auxiliary pressure bonding portion 51 is formed by a nip roll in the same manner as the pressure bonding portion 5. The auxiliary pressure bonding portion 51 is provided in an auxiliary manner to increase the peeling strength between the nonwoven fabric 3 and the elastic film 2, and needs to be formed within a range that does not impair the elasticity. Therefore, at least a width Wb in an elastic direction Dl of the auxiliary pressure bonding portion 51 needs to be smaller than a width Wc in the elastic direction Dl of the pressure bonding portion 5 (a width in the elastic direction of the pressure bonding line); in the present embodiment, a width Wd in the one direction D2 of the auxiliary pressure bonding portion 51 is smaller than a length La in the one direction D2 of the pressure bonding portion 5, and further an area of the auxiliary pressure bonding portion 51 is, for example, equal to or smaller than half of an area of the pressure bonding portion 5, desirably equal to or smaller than one-third thereof, and more desirably equal to or smaller than one fifth thereof.

As illustrated in FIG. 10, an elastic laminate sheet 1C according to a third embodiment is further provided with a linking section 52 linking a plurality of pressure bonding portions 5 in one direction D2 with respect to the elastic laminate sheet 1B according to the second embodiment. Specifically, in the elastic laminate sheet 1C, a pressure bonding line 8 is formed by the plurality of pressure bonding portions 5 aligned in the one direction D2 and the linking sections 52 linking the plurality of pressure bonding portions 5. In both the pressure bonding portion 5 and the linking section 52, a nonwoven fabric 3 and an elastic film 2 are pressure-bonded and recessed. A width Wa in a lateral direction D3 of the pressure bonding portion 5 is wider than a width of the linking section 52.

As illustrated in FIG. 11, in an elastic laminate sheet 1D according to a fourth embodiment, a pressure bonding line 8 is formed by a single pressure bonding portion 5A extending along one direction D2, and a plurality of pressure bonding lines 8 is arranged side by side in a lateral direction D3 orthogonal to the one direction D2. A width Wf in the lateral direction D3 of the pressure bonding line 8 is substantially constant in the one direction D2.

In the elastic laminate sheets 1B to 1D according to the second to third embodiments are each provided with the pressure bonding line 8 extending in the one direction D2; the one direction D2, which is an extending direction of the pressure bonding line 8, is inclined with respect to the elastic direction Dl, and in particular, the inclination angle Q is equal to or larger than 15° and equal to or smaller than 75°. Therefore, the elasticity is unlikely to be lowered as compared with a mode in which the pressure bonding line 8 is formed along the elastic direction Dl . As a result, it is advantageous to have the above-discussed configuration in a sense that the peeling strength between the elastic film 2 and the nonwoven fabric 3 is enhanced while maintaining adequate elasticity.

The elastic laminate sheets 1B and 1C according to the second and third embodiments are further provided with the auxiliary pressure bonding portions 51, which is advantageous for improving the peeling strength. Furthermore, in each of the elastic laminate sheets 1C and 1D according to the third and fourth embodiments, the pressure bonding line 8 is formed by the continued pressure bonding portion 5 or 5A, which is advantageous for improving the peeling strength. Note that, it is also possible for the elastic laminate sheet 5D according to the fourth embodiment to be configured to include the auxiliary pressure bonding portion 51.

Furthermore, in the elastic laminate sheets 1 A to 1D according to the embodiments described above, for example, the configurations and dimensions of the pressure bonding line 8 may be defined such that a value (load) for evaluating the elasticity takes the following value. To be specific, under the conditions of a temperature of 23 ± 2°C and humidity of 50 ± 5%, a 75% extension is performed at a rate of 300 mm/minute on the elastic film with the nonwoven fabric peeled off, thereafter, at a rate of 300 mm/minute, the elastic laminate sheet is returned to the initial position before the extension, and then a load may be equal to or less than 2.5 N/25 mm when a 50% extension is further performed at a rate of 300 mm/minute. By defining the load to be as the above-described definition, such an advantage is brought that the elasticity is maintained in the case where the above elastic laminate sheet is applied to a tab portion of a hygienic material such as an adult diaper.

Furthermore, the configuration may also be such that the above-discussed load is equal to or smaller than 1.6 N/25 mm. By defining the load to be as the

above-described definition, such an advantage is brought that the elasticity is maintained in the case where the above elastic laminate sheet is applied to a tab portion of a hygienic material such as an infant diaper. Note that the load may be set to equal to or larger than 0.5 N/25 mm.

Furthermore, in the elastic laminate sheets 1 A to 1D according to the embodiments described above, for example, the configurations and dimensions of the pressure bonding line 8 may also be defined such that a value for evaluating the peeling strength takes the following value. To be specific, under the conditions of a temperature of 23 ± 2°C and humidity of 50 ± 5%, a peeling test is performed in which the elastic film and the nonwoven fabric are peeled at a peel rate of 500 mm/minute along a peeling direction as a direction opposite to both the elastic film and the nonwoven fabric. Then, an integral average of a plurality of adhesive strengths obtained during the peeling is determined, and the definition is made to cause the determined value to be equal to or larger than 3.5 N/15 mm, which is advantageous for improving the peeling strength.

The arrangement of the plurality of pressure bonding portions 5 forming the pressure bonding line 8 does not need to be strictly aligned (completely coaxial) with the one direction D2, and there may be some variations in the arrangement. For example, even in a case where the plurality of pressure bonding portions 5 is shifted to the lateral direction D3 to form a zigzag arrangement, it is sufficient that the one direction D2 can be identified as a trend. Specifically, the one direction D2 can be easily identified as long as an off-alignment width to the left and right of the pressure bonding portion 5 is approximately equal to the width Wa in the lateral direction D3 of the pressure bonding portion 5.

The arrangement of the plurality of pressure bonding lines 8 aligned in the lateral direction D3 is not limited to the arrangement in which the pressure bonding lines 8 are aligned adjacent to each other, or the arrangement in which the pressure bonding lines 8 are aligned at every other line while sandwiching the auxiliary pressure bonding portion 51 or the like therebetween, and the arrangement may be such that the pressure bonding lines 8 are aligned at every several lines in the lateral direction D3, for example.

Furthermore, the arrangement is not limited to a case where the plurality of pressure bonding lines 8 aligned in the lateral direction D3 is in the same configuration. For example, the above-described embodiments or other modes can be combined as appropriate, and the pressure bonding lines 8 according to the above-described embodiments or other modes may be arbitrarily arranged or repeatedly arranged at a constant period in the arrangement configuration. For example, in the case of the arrangement of the plurality of pressure bonding lines 8, the pressure bonding portion 5 of a first pressure bonding line 8 is formed in an oval shape, the pressure bonding portion 5 of a second pressure bonding line 8 adjacent to the first pressure bonding line 8 is formed in a rectangular shape, the pressure bonding portion 5 of a third pressure bonding line 8 adjacent to the second pressure bonding line 8 is formed in a diamond shape; then the first to third pressure bonding lines 8 may have a configuration in which a pattern of the first to third pressure bonding lines 8 is taken as one cycle and repeated while being aligned in the lateral direction D3. Furthermore, for example, while causing the pressure bonding portions 5 forming the first pressure bonding line 8 and the second pressure bonding line 8 to have the same shape (such as an oval), the intervals between the pressure bonding portions 5 aligned in the one direction D2 may be different, the sizes of the pressure bonding portions 5 may be different, or the like.

EXAMPLES

The present invention will be described more specifically below using examples, but the present invention is not intended to be limited to the examples. Note that, for the elastic film, a common elastic film was used in the examples and comparative examples. Specifically, an elastic film having a basis weight of 45 gsm produced using a SIS copolymer (trade name“Quitac3390” 50%,“Quitac3620” 50%, manufactured by Zeon Corporation) was used. In Examples 1 to 4 to be described below, and Comparative Examples 1 and 2 to be described below, a spunbond nonwoven fabric of PET90% and PPl0% (basis weight 32 gsm) was used as a nonwoven fabric material.

Example 1

By using a simultaneous melt-extrusion lamination apparatus as illustrated in FIG. 5, laminate conditions were set as an elastomer melt temperature in the extruder being 240°C, nip pressure being 0.1 Mpa, a distance between the bottom surface of a recess of a nip roll and the surface of a cooling roll being 3 mm, and then an elastic laminate sheet in which a nonwoven fabric was laminated on both surfaces of an elastic film was produced. An elastomer was fed into a single screw extruder and discharged from a T-die such that the basis weight of a resultant elastic film was 45 g/m ² .

Subsequently, immediately before the melted elastic film entered a gap between the cooling roll and the nip roll, nonwoven fabrics having been produced beforehand were inserted from both the nip roll side and the cooling roll side. The melted elastic film and the nonwoven fabrics were made in contact with each other between the cooling roll and the nip roll, and then the melted elastic film solidified, whereby a three-layer elastic laminate sheet in which the nonwoven fabrics were laminated on both surfaces of the elastic film was obtained. The obtained elastic laminate sheet was taken up by a wind-up roll.

The elastic laminate sheet according to Example 1 was provided with a pressure bonding line (see FIG. 2) having a pattern corresponding to the first embodiment described above. A dimension in the longitudinal direction of a plurality of pressure bonding portions forming the pressure bonding line was 0.7 to 2 mm. An inclination angle of the pressure bonding line with respect to the elastic direction, that is, the inclination angle of one direction in which the pressure bonding line extends was 45°. An occupancy ratio of the pressure bonding portions in a predetermined region was 9%. Example 2

An elastic laminate sheet according to Example 2 was manufactured in the same manner as in Example 1 with the exception that a pressure bonding pattern was different therefrom. The elastic laminate sheet according to Example 2 was provided with a pressure bonding line having a pattern (see FIG. 9) corresponding to the second embodiment described above. A dimension in the longitudinal direction of a plurality of pressure bonding portions forming the pressure bonding line was 0.7 to 2 mm. An inclination angle of one direction with respect to the elastic direction was 45°. An auxiliary pressure bonding portion was substantially circular in shape, and an inner diameter thereof was 0.3 mm. The occupancy ratio of the pressure bonding portions and the auxiliary pressure bonding portions in a predetermined region was 13%.

Example 3

An elastic laminate sheet according to Example 3 was manufactured in the same manner as in Example 1 with the exception that a pressure bonding pattern was different therefrom. The elastic laminate sheet according to Example 3 was provided with a pressure bonding line having a pattern (see FIG. 10) corresponding to the third embodiment described above. The inclination angle of one direction with respect to the elastic direction was 45°. A dimension in the longitudinal direction of a plurality of pressure bonding portions forming the pressure bonding line was 0.7 to 2 mm. A width in a lateral direction of a linking section linking the plurality of pressure bonding portions was 0.2 mm. An auxiliary pressure bonding portion was substantially circular in shape, and an inner diameter thereof was 0.3 mm. The occupancy ratio of the pressure bonding portions, the linking sections, and the auxiliary pressure bonding portions in a predetermined region was 17%.

Example 4 An elastic laminate sheet according to Example 4 was manufactured in the same manner as in Example 1 with the exception that a pressure bonding pattern was different therefrom. The elastic laminate sheet according to Example 4 was provided with a pressure bonding line (see FIG. 11) having a pattern corresponding to the fourth embodiment described above. The inclination angle of one direction with respect to the elastic direction was 45°. A dimension in the lateral direction of pressure bonding portions forming the pressure bonding line was 0.7 mm. An auxiliary pressure bonding portion was substantially circular in shape, and an inner diameter thereof was 0.3 mm. The occupancy ratio of the pressure bonding portions in a predetermined region was 7%.

Comparative Example 1

An elastic laminate sheet according to Comparative Example 1 was manufactured in the same manner as in Example 1 with the exception that a pressure bonding pattern was different therefrom. The elastic laminate sheet according to Comparative Example 1 did not include a pressure bonding portion for forming a pressure bonding line, and instead, pressure bonding portions each formed in a substantially circular shape were evenly disposed. The inner diameter of the pressure bonding portion was 0.3 mm, and the occupancy ratio of the pressure bonding portions in a predetermined region was 4%.

Comparative Example 2

An elastic laminate sheet according to Comparative Example 2 was manufactured in the same manner as in Comparative Example 1 with the exception that a pressure bonding pattern was different therefrom. The elastic laminate sheet according to Comparative Example 2 did not include a pressure bonding portion for forming a pressure bonding line, and instead, pressure bonding portions each formed in a substantially circular shape were evenly disposed. The inner diameter of the pressure bonding portion was 0.3 mm, and the occupancy ratio of the pressure bonding portions in a predetermined region was 6%. In other words, an interval between the pressure bonding portions is smaller in Comparative Example 2 than in Comparative Example 1. 50% Forward Load, 50% Return Load

In order to evaluate the elasticity of the elastic laminate sheets according to Examples 1 to 4 and Comparative Examples 1 and 2,“50% forward load” and“50% return load” were measured. For the measurement, samples were prepared in a room held at a temperature of 23 ± 2°C and humidity of 50 ± 5%, and the measurement was performed after storing the samples for one hour. For the cutout of elastic laminate sheet samples, the dimensions were measured using a stainless steel ruler

(manufactured by Shinwa Corp.), the ruler was put on a sample to be cut out, and then the sample was cut out using a knife (Feather S Seikan single-edge, blade thickness: 0.245 mm).

Consequently, the sample of an elastic laminate sheet was cut out in a rectangular shape with a size of 50 mm in an elastic direction (CD) of an elastic film and 25 mm in a direction (MD) perpendicular to the extending direction, and then the nonwoven fabric was peeled from both surfaces of an elastic film 2X. When the nonwoven fabric was peeled from the elastic film 2X, the elastic film 2X was prevented from being extended by 3 mm or more. As illustrated in FIG. 12 A, two sealing materials 31 and 32 (ScotchTM Premium Grade Filament Tape, product number“898, width 25 mm”, manufactured by 3M Company) cut into a length of 40 mm and two sealing materials 33 and 34 (ScotchTM Premium Grade Filament Tape, product number“898”, manufactured by 3M Company) cut into a length of 40 mm were respectively attached to both ends in the elastic direction (CD) of the elastic film 2X from which the nonwoven fabric had been peeled. The sealing material 31 and the sealing material 32 were attached so that the adhesive surfaces thereof overlapped each other, and the sealing material 33 and the sealing material 34 were attached so that the adhesive surfaces thereof overlapped each other. Furthermore, the sealing materials 31 to 34 were attached so that the sample length in the MD direction of the elastic film 2X was 25 mm.

As illustrated in FIGS. 13A to 13C, the sealing material attaching portions of the prepared sample were mounted on a movable chuck 35 on the upper side of a Tensilon tester (model number RTG-1225, manufactured by Orientec Corporation) and a fixed chuck 36 on the lower side thereof, respectively. At that time, the distance between the chucks was adjusted to 15 mm by the upper-side chuck 35, and fixed so as to obtain a non-tension state. The shape of the chuck was such that the width was equal to or larger than 25 mm, and the height was equal to or larger than 25 mm. After the fixation, it was confirmed that there were no wrinkles or folds in the elastic film 2X. The sample was extended upward in the vertical direction by 15 mm at a rate of 300 mm/minute, and the sample was then returned to a position of the initial distance between the chucks at a rate of 300 mm/minute. This was evaluated as a 100% extension sample. A 170% extension sample to be described below was extended by 25.5 mm at a rate of 300 mm/minute in the manner as described above, and then the sample was returned to a position of the initial distance between the chucks at a rate of 300 mm/minute.

When the sample was returned to the initial position, the fixing of the chucks 35 and 36 was once released and the sample was dismounted. Again, this sample was sealed with sealing materials 37 (38) and 39 (40) from the upper side of the sealing materials 31 (32) and 33 (34), respectively, as illustrated in FIG. 12B. As illustrated in FIG. 14 A, the measurement sample was fixed so that a range of the first pulling was set between the chucks 35 and 36 of the tensile strength tester being spaced by 15 mm (the load was prevented from being applied to the measurement sample during the fixation). Next, the measurement sample (elastic film 2X) was extended by 11.25 mm at a rate of 300 mm/minute (FIG. 14B), and thereafter, the sample was returned to a position of the extension distance being 0 mm. A load (N/25 mm) was continuously recorded, and at the first forward extension, the forward load at a position of the extension distance of

7.5 mm (the chuck distance being 22.5 mm) (see FIG. 14C) was taken as a“50% forward load”. At the time of the first return, the return load at the extension distance of

7.5 mm (the distance between the chucks being 22.5 mm) was evaluated as a“50% return load”.

Tensile Strength

The tensile strength was measured to evaluate the difficulty in breaking the elastic laminate sheets according to Examples 1 to 4 and Comparative Examples 1 and 2. In the tensile strength measurement, a sample was produced in the same manner as the stress measurement described above, and then a 100% extension sample

(measurement sample) was produced. Similarly to the stress measurement described above, as illustrated in FIGS. 14A to 14C, the measurement sample was fixed so that a range of the first pulling was set between the chucks (fixed portions) of the tensile strength tester being spaced by 15 mm (the load was prevented from being applied to the measurement sample during the fixation). In this state, the measurement sample was extended at a rate of 100 mm/minute until the sample broke. A load (N/25 mm) was recorded continuously, and the maximum load was evaluated as tensile strength. Peeling Strength

Measurement was performed to evaluate the peeling strength of the elastic laminate sheets according to Examples 1 to 4 and Comparative Examples 1 and 2. Samples were prepared in a room held at a temperature of 23 ± 2°C and humidity of 50 ± 5%, and the measurement was performed after storing the samples for one hour. For the cutout of samples, the dimensions were measured using a stainless steel ruler (manufactured by Shinwa Corp.), the ruler was put on a sample to be cut out, and then the sample was cut out using a knife (Feather S Seikan single-edge, blade thickness: 0.245 mm).

A measurement sample was produced by cutting out an elastic laminate sheet sample (a three-layer structure formed of nonwoven fabric/elastic film/nonwoven fabric) to a shape with a width of 45 mm (in the CD direction) and a length of 80 mm (in the MD direction).

As illustrated in FIG. 15, such a jig was prepared that nips long side portions la of a sample IX for measurement by 10 mm from both end portions. In the jig, stainless steel panels 41, 42, 43, and 44 having a width of 52 mm, a length of 100 mm and a thickness of 2 mm were prepared, and hook and loop fasteners 45, 46, 47, and 48 (mechanical fastener, product number“NC-2141”, width 25 mm, manufactured by 3M Company) were attached to wide-enough flat surfaces, along the long side portions la, of the stainless steel panels 41, 42, 43, and 44, respectively.

Two sides to be the long side portions la of the sample IX were nipped by 15 mm by the stainless steel panels 41, 42, 43, and 44 respectively provided with the hook and loop fasteners 45, 46, 47, and 48. Thereafter, the sample IX was extended in the elastic direction thereof by 15 mm at a rate of 50 mm/minute, and then the sample was returned to the original width at the same rate. The stated sample was taken as a 100% extension sample. In addition, the sample that had been extended by 25.5 mm and was returned to the original width was taken as a 170% extension sample. As for the post-extension sample IX, the portions nipped by the stainless steel panels 41, 42, 43, and 44 were removed, and the sample X was cut out to a shape with a width of 15 mm (CD direction) and a length of 80 mm (MD direction).

As illustrated in FIGS. 16A and 16B, a laminated nonwoven fabric 3Y was peeled from an elastic film 2Y from one end of a short side portion of the sample IX in parallel to a distance of 20 mm. After the peeling, in the case where the width of the nonwoven fabric 3Y was widened, the width was returned to the width 15 mm which equals the width before the peeling. Note that the peeled nonwoven fabric 3 Y was on the side where the pressure bonding portion was formed. A Japanese paper tape (flat paper masking tape 243J, product number“243JDIY-24”, manufactured by 3M Company) 49 was bonded to a surface of a not-peeled nonwoven fabric 4Y so that it does not project from the sample IX.

Two nonwoven fixing tapes 61 and 62 (ScotchTM Premium Grade Filament Tape, product number“898 width 25 mm”, manufactured by 3M Company) cut to a length of 30 mm were made to nip the peeled nonwoven fiber 3 Y from an end portion thereof in parallel to a position of 10 mm, so as to fix the end portion of the peeled nonwoven fabric 3 Y. Nonwoven fabric fixing tapes 63 and 64 (ScotchTM Premium Grade Filament Tape, product number“898 width 25 mm”, manufactured by 3M Company) were attached to the portion, which is not peeled, of the nonwoven fabric in the manner described above.

The sample was fixed in a Tensilon tester (model No. RTG-1225, manufactured by Orientec Corporation) with no tension, so that a distance between chucks was 20 mm. The shape of chucks 65 and 66 was such that the width is equal to or larger than 25 mm and the height was equal to or larger than 25 mm. At that time, the nonwoven fabric fixing tapes 61 and 62 attached to the end of the peeled nonwoven fabric 3Y were fixed to the movable chuck 65 on the upper side so as not to project from the lower portion of the chuck 65. The remaining layer (layer formed of the elastic film/nonwoven fabric/Japanese paper tape), which was the layer remaining after the peeling of the nonwoven fabric 3 Y, was fixed to the chuck 66 fixed on the lower side to a position of 10 mm from the end portion.

The chuck 65 was pulled upward in the vertical direction at a rate of 500 mm/minute to record the peeling strength. At that time, an angle formed by the sample surface formed of the nonwoven fabric/elastic film/nonwoven fabric/Japanese paper tape was maintained at approximately 60° with respect to the sample plane forming a peeling interface of the nonwoven fabric 3 Y and the elastic film 2Y from the fixed chuck 66 on the lower side.

An integral average of the data of the recorded tension (N/15 mm), from the start of pulling, for a distance of 25 mm from 15 mm to 40 mm was defined as adhesive strength. The integral average is expressed by the following Equation (1) when the adhesive strength f(x) (N/15 mm) is continuous in the measurement lengths a, b, (a < x < b) (a = 15 mm, b = 40 mm). Note that f(x) was acquired from the tension recorded by the Tensilon tester.

Equation 1

In the examples and comparative examples, the measurement of the adhesive strength determined above was performed five times on the same sample, and the average value was taken as the peeling strength.

The measurement values of“50% forward load”,“50% return load”,“tensile strength”, and“peeling strength” in Examples 1 to 4 and Comparative Examples 1 and 2 are shown in Table 1.

Table 1

Assume a case where an elastic laminate sheet is used in a tab portion of an open type diaper. Here, in the case where the wearer is an adult such as an elderly person, when the“50% forward load” is equal to or smaller than 2.5 (N/25 mm), the tab portion is pulled without particular attention being paid by the caregiver or the like, and the diaper can be naturally put on the wearer. In the case where the wearer is an infant or the like, when the“50% forward load” is less than 1.6 (N/25 mm), the tab portion can be pulled without particular attention being paid by the parents or the like, and the diaper can be naturally put on the wearer.

When the peeling strength is equal to or greater than 3.5 (N/15 mm), the nonwoven fabric will not peel off from the elastic film while the diaper is being put on a wearer or the diaper is being worn (in use). Note that when the“tensile strength” is equal to or greater than 14 (N/15 mm), in normal use, the tab portion will not be ripped to be broken.

As shown in Table 1, in Examples 1 to 4, the“50% forward load” was less than 1.6 (N/25 mm) and the peeling strength was equal to or greater than 3.5 (N/15 mm). In each of Comparative Examples 1 and 2, the peeling strength was less than 3.5 (N/15 mm).

Next, Examples 5 to 8 and Comparative Examples 3 and 4 will be described. In Examples 5 to 8 and Comparative Examples 3 and 4, unlike Example 1 and the like described above, a spunbond nonwoven fabric of PET90% and PPl0% (basis weight 38 gsm) was used as a nonwoven fabric material. Example 5

An elastic laminate sheet according to Example 5 was manufactured by the same method as in Example 1 with the exception that the nonwoven fabric was different.

Example 6

An elastic laminate sheet according to Example 6 was manufactured by the same method as in Example 2 with the exception that the nonwoven fabric was different.

Example 7

An elastic laminate sheet according to Example 7 was manufactured by the same method as in Example 3 with the exception that the nonwoven fabric was different.

Example 8

An elastic laminate sheet according to Example 8 was manufactured by the same method as in Example 4 with the exception that the nonwoven fabric was different.

Comparative Example 3

An elastic laminate sheet according to Comparative Example 3 was manufactured by the same method as in Comparative Example 1 with the exception that the nonwoven fabric was different.

Comparative Example 4

An elastic laminate sheet according to Comparative Example 4 was manufactured by the same method as in Comparative Example 2 with the exception that the nonwoven fabric was different.

With the same measurement methods as described above, in Examples 5 to 8 and Comparative Examples 3 and 4, the measurement of“50% forward load”,“50% return load”,“tensile strength”, and“peeling strength” was performed. The measurement values thereof are shown in Table 2.

Table 2

As shown in Table 2, in Examples 5 to 8, the“50% forward load” was equal to or smaller than 2.5 (N/25 mm), and the peeling strength was equal to or greater than 3.5 (N/15 mm). Note that in each of Comparative Example 3 and 4, the peeling strength was less than 3.5 (N/15 mm).

Next, Examples 9 to 12 and Comparative Examples 5 and 6 will be described. In Example 9 to 12 and Comparative Examples 5 and 6, unlike Example 1 and the like described above, a spunbond nonwoven fabric of PET90% and PPl0% (basis weight 50 gsm) was used as a nonwoven fabric material.

Example 9

An elastic laminate sheet according to Example 9 was manufactured by the same method as in Example 1 with the exception that the nonwoven fabric was different.

Example 10

An elastic laminate sheet according to Example 10 was manufactured by the same method as in Example 2 with the exception that the nonwoven fabric was different.

Example 11

An elastic laminate sheet according to Example 11 was manufactured by the same method as in Example 3 with the exception that the nonwoven fabric was different.

Example 12

An elastic laminate sheet according to Example 12 was manufactured by the same method as in Example 4 with the exception that the nonwoven fabric was different.

Comparative Example 5

An elastic laminate sheet according to Comparative Example 5 was manufactured by the same method as in Comparative Example 1 with the exception that the nonwoven fabric was different.

Comparative Example 6

An elastic laminate sheet according to Comparative Example 6 was manufactured by the same method as in Comparative Example 2 with the exception that the nonwoven fabric was different.

With the same measurement methods as described above, in Examples 9 to 12 and Comparative Examples 5 and 6, the measurement of“50% forward load”,“50% return load”,“tensile strength”, and“peeling strength” was performed. The measurement values are shown in Table 3.

Table 3

As shown in Table 3, in Examples 9 and 10, the“50% forward load” was less than 1.6 (N/25 mm) and the peeling strength was equal to or greater than 3.5 (N/15 mm). In Examples 11 and 12, the“50% forward load” was equal to or smaller than 2.5 (N/25 mm), and the peeling strength was equal to or greater than 3.5 (N/15 mm). Note that in each of Comparative Example 3 and 4, the peeling strength was less than 3.5 (N/15 mm).

Next, Examples 13 to 18 and Comparative Examples 7 to 14 will be described. In Examples 13 to 18 and Comparative Examples 7 to 14, unlike Example 1 and the like described above, a spunbond nonwoven fabric of PET90% and PPl0% (basis weight 32 gsm) was used as a nonwoven fabric material.

Example 13

An elastic laminate sheet according to Example 13 was manufactured by the same method as in Example 1 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different. Pressure bonding portions according to Example 3 were so arranged as to be aligned in the lateral direction between the adjacent pressure bonding lines.

Example 14

An elastic laminate sheet according to Example 14 was manufactured by the same method as in Example 13 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different.

Example 15

An elastic laminate sheet according to Example 15 was manufactured by the same method as in Example 13 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different.

Example 16

An elastic laminate sheet according to Example 13 was manufactured by the same method as in Example 1, with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction and the arrangement of pressure bonding portions are different. The arrangement of the pressure bonding portions according to Example 16 is shifted from the lateral direction between the adjacent pressure bonding lines in such a manner that the pressure bonding portions are disposed in a staggered pattern.

Example 17

An elastic laminate sheet according to Example 17 was manufactured by the same method as in Example 16 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different.

Example 18

An elastic laminate sheet according to Example 18 was manufactured by the same method as in Example 16 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different.

Comparative Example 7

An elastic laminate sheet according to Comparative Example 7 was manufactured by the same method as in Example 13 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different.

Comparative Example 8

An elastic laminate sheet according to Comparative Example 8 was manufactured by the same method as in comparative Example 7 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different.

Comparative Example 9

An elastic laminate sheet according to Comparative Example 9 was manufactured by the same method as in Comparative Example 7 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different.

Comparative Example 10

An elastic laminate sheet according to Comparative Example 10 was manufactured by the same method as in comparative Example 7 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different.

Comparative Example 11

An elastic laminate sheet according to Comparative Example 11 was manufactured by the same method as in Example 16 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different.

Comparative Example 12

An elastic laminate sheet according to Comparative Example 12 was manufactured by the same method as in Comparative Example 11 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different.

Comparative Example 13

An elastic laminate sheet according to Comparative Example 13 was manufactured by the same method as in Comparative Example 11 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different.

Comparative Example 14

An elastic laminate sheet according to Comparative Example 14 was manufactured by the same method as in Comparative Example 11 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different.

With the same measurement methods as described above, in Examples 13 to 18 as well, the measurement of“50% forward load”,“50% return load”,“tensile strength”, and“peeling strength” was performed. The measurement values are shown in Table 4. With the same measurement methods as described above, in Comparative Examples 7 to 14 as well, the measurement of“50% forward load”,“50% return load”,“tensile strength”, and“peeling strength” was performed. The measurement values are shown in Table 5. Table 4

Table 5

As shown in Table 4, in Examples 13 to 18, the“50% forward load” was less than 1.6 (N/25 mm) and the peeling strength was equal to or greater than 3.5 (N/15 mm). As shown in Table 5, in each of Examples 7, 8, 11, and 12, the“50% forward load” was equal to or greater than 1.6 (N/25 mm), and the peeling strength was smaller than 3.5 (N/15 mm). In addition, in Comparative Examples 9, 10, 11, and 12, the peeling strength was less than 3.5 (N/15 mm).

Next, Examples 19 to 21 and Comparative Examples 15 to 18 will be described. In Examples 19 to 21 and Comparative Examples 15 to 18, unlike Example 1 and the like described above, a spunbond nonwoven fabric of PET90% and PPl0% (basis weight 50 gsm) was used as a nonwoven fabric material.

Example 19

An elastic laminate sheet according to Example 19 was manufactured by the same method as in Example 5 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different. Pressure bonding portions according to Example 3 were so arranged as to be aligned in the lateral direction between the adjacent pressure bonding lines.

Example 20

An elastic laminate sheet according to Example 20 was manufactured by the same method as in Example 19 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different.

Example 21

An elastic laminate sheet according to Example 21 was manufactured by the same method as in Example 19 with the exception that an inclination angle of one direction as an extension direction of a pressure bonding line with respect to the elastic direction was different.

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As shown in Table 6, in Examples 15 to 17, the“50% forward load” was less than 1.6 (N/25 mm) and the peeling strength was equal to or greater than 3.5 (N/15 mm). Note that, in each of Examples 15 to 18, the“50% forward load” was equal to or greater than 1.6 (N/25 mm), and the peeling strength was smaller than 3.5 (N/15 mm). In addition, in Comparative Examples 9, 10, 11, and 12, the peeling strength was less than 3.5 (N/15 mm). In Comparative Examples 15 and 16, it was not possible to measure the peeling strength because the nonwoven fabric was ripped at the time of measuring the peeling strength.

Although the embodiments and examples have been described thus far, the present invention is not limited to the aforementioned embodiments and examples only. For example, the hygienic material using the elastic laminate sheet is not limited to a disposable diaper, any may be a disposable sanitary cap. The elastic laminate sheet may also be used in a head fastening portion of a disposable sanitary cap in addition to the tab portion of the disposable diaper. Furthermore, the elastic laminate sheet may also be used in applications such as a supporter, a bandage, an ear-hook portion of a mask, a heat retaining member, and the like.

Reference Signs List

Wc Width in elastic direction of pressure bonding line