JP2017164996A - Porous stretchable film and method for producing the same, and composite sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a porous stretchable film which suppresses occurrence of blocking, has good air permeability, is hardly broken when stretched, and has elasticity that is hardly lowered and a method for producing the same; and a composite sheet.SOLUTION: A porous stretchable film 10 has an elastomer layer containing a thermoplastic elastomer and a surface layer that is provided on one or both of a first surface and a second surface of the elastomer layer and contains a thermoplastic resin, has a plurality of through holes 13 formed therein, and the porous stretchable film 10 alternately has a first region 11 that extends in a plane direction of the porous stretchable film 10 and has a belt shape, and a second region 12 that is adjacent to the first region 11, is more hardly stretched than the first region 11, extends in the plane direction of the porous stretchable film 10, and has a belt shape.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a porous stretchable film in which a plurality of through holes are formed, a method for producing the same, and a composite sheet having a layer made of a porous stretchable film and a layer made of a nonwoven fabric.

  In the hygiene field (sanitary products, incontinence products, etc.), the medical field (surgical drapes, etc.), etc., a stretchable composite sheet in which a stretchable film containing a thermoplastic elastomer and a nonwoven fabric are laminated is widely used. .

Since the thermoplastic elastomer has strong adhesiveness, the stretchable films and the composite sheets are in close contact with each other, and so-called blocking that is difficult to peel off may occur.
For example, the following films have been proposed as stretchable films in which the occurrence of blocking is suppressed.
(1) An elastic film having an elastomer layer containing a thermoplastic elastomer and a surface layer containing a thermoplastic resin provided on both the first surface and the second surface of the elastomer layer (Patent Document 1).

In addition, since the stretchable film is easy to fit into the body without any gaps, it may cause stuffiness or rash. Therefore, a porous stretchable film having good air permeability is desired. As a method for opening the film, generally, slitting, punching, hot needle punching, hot roll calendering, ultrasonic perforation and the like can be mentioned.
For example, the following are proposed as the porous stretchable film.
(2) A net-like stretchable film in which openings such as slits and holes are formed in a stretchable film containing a thermoplastic elastomer (Patent Document 2).

International Publication No. 2016/013577 JP 2002-155460 A

If the technique for producing the network stretchable film of (2) is applied to the stretchable film of (1), the occurrence of blocking is suppressed, and a porous stretchable film having good air permeability is obtained.
However, since the stretchable film of (1) has a non-stretchable surface layer, the stretchability is slightly insufficient. Therefore, in the porous stretchable film in which the opening is formed on the stretchable film of (1) by a general method such as slitting, when the film is stretched, stress concentrates on the opening and is easily broken from the opening. As a result, the stretchability of the porous stretchable film further decreases.

  The present invention provides a porous stretchable film in which the occurrence of blocking is suppressed, the air permeability is good, and the stretchable film is difficult to break when stretched, and the stretchability is not easily lowered.

The present invention has the following aspects.
<1> A surface containing an elastomer layer containing a thermoplastic elastomer and a thermoplastic resin (excluding the thermoplastic elastomer) provided on one or both of the first surface and the second surface of the elastomer layer. A porous stretchable film having a plurality of through-holes; the porous stretchable film extending in the plane direction of the porous stretchable film; and the first region A porous stretchable film having alternating strip-shaped second regions extending along the surface direction of the porous stretchable film that are adjacent to each other and are less likely to extend than the first region.
<2> The porous stretchable film according to <1>, wherein an average opening area of the through holes is 0.1 to 1.5 mm ² .
<3> The porous stretchable film according to <1> or <2>, wherein the number of through holes is 1 to 20 per 1 cm ² of the porous stretchable film.
<4> The porous stretchable film according to any one of <1> to <3>, wherein the surface layer further contains an inorganic filler.
<5> A method for producing a porous stretchable film according to any one of the above <1> to <4>, comprising: an elastomer layer containing a thermoplastic elastomer, and any one of a first surface and a second surface of the elastomer layer By embossing a non-porous stretch film having a surface layer containing a thermoplastic resin (excluding the thermoplastic elastomer) provided on one or both, a plurality of depressions scattered in the non-porous stretch film Forming a portion; a first shaping roll having a plurality of ridges extending in the circumferential direction or the axial direction; and a first shaping roll having a plurality of ridges extending in the same direction as the projections of the first shaping roll. The first shaping roll while rotating the two shaping rolls so as to face each other so that the ridges of one shaping roll and the grooves between the ridges of the other shaping roll mesh with each other. The second shaping roll; The first region stretched between the ridges of the first shaping roll and the ridges of the second shaping roll by passing the embossed non-porous stretch film therebetween And forming the second region that has not been stretched, and simultaneously forming the through hole by stretching the hollow portion.
<6> The method for producing a porous stretchable film according to <5>, wherein the following permanent strain of the non-porous stretchable film is 15% or more.
(Permanent strain of non-porous stretch film)
A strip-shaped test piece of 50 mm in the machine direction (MD) and 200 mm in the width direction (TD) is cut out from the non-porous stretch film. The test piece is fixed to the grip of the test apparatus so that the distance between the grips is 100 mm. The test piece is stretched at TD at a speed of 100 mm / min so that the elongation calculated by the following formula (I) is 80%, and then the test piece is immediately contracted at the same speed. Permanent strain (%) is calculated from the following formula (II).
Elongation = (L1-L0) / L0 × 100 (I)
Permanent strain = (L2-L0) / (L1-L0) × 100 (II)
However, L0 is the distance (mm) between grips before extending | stretching, L1 is the distance (mm) between grips after extending | stretching, L2 is the load (N / This is the distance (mm) between grips when (50 mm) becomes zero.
<7> A composite sheet having a layer formed of the porous stretchable film according to any one of <1> to <4> and a layer formed of a nonwoven fabric.

In the porous stretchable film of the present invention, the occurrence of blocking is suppressed, the air permeability is good, and when stretched, it is difficult to break and stretchability is unlikely to decrease.
According to the method for producing a porous stretchable film of the present invention, it is possible to produce a porous stretchable film in which occurrence of blocking is suppressed, air permeability is good, and it is difficult to break when stretched and stretchability is not easily lowered.
In the composite sheet of the present invention, the occurrence of blocking due to the layer made of the porous stretchable film is suppressed, the air permeability is good, and the layer made of the porous stretchable film hardly breaks when stretched, and the stretchability is hardly lowered.

It is the photograph which looked at an example of the porous elastic film of the present invention from the upper surface. It is an enlarged photograph of the porous elastic film of FIG. It is an enlarged photograph of the state which extended | stretched the porous elastic film of FIG. 1 so that elongation might become 80% in TD. It is sectional drawing which shows an example of the non-porous stretch film used for manufacture of the porous stretch film of this invention. It is an enlarged view which shows an example of a pair of shaping roll. It is an enlarged view which shows the other example of a pair of shaping roll.

The following definitions of terms apply throughout this specification and the claims.
“Thermoplastic elastomer” is a material that has characteristics similar to vulcanized rubber at the operating temperature, disappears at the processing temperature, can be easily processed, and returns to its original properties when returned to the operating temperature. It means a polymer or polymer blend.
“Thermoplastic resin” means a synthetic resin that can be molded by heating to a degree that can be molded. However, in the present invention, the thermoplastic resin does not include a thermoplastic elastomer.
“The second region is less likely to extend than the first region (the first region is easier to extend than the second region)” means that the porous stretchable film has a length of the first region and the second region. When stretched in a direction perpendicular to the direction, the elongation (%) of the second region is smaller than the elongation (%) of the first region (the elongation of the first region is smaller than the elongation (%) of the second region). (Elongation (%) is large).

<Porous stretch film>
The porous stretchable film of the present invention is a stretchable film in which a plurality of through holes are formed.
The porous stretchable film of the present invention includes an elastomer layer containing a thermoplastic elastomer and a thermoplastic resin (excluding the thermoplastic elastomer) provided on one or both of the first surface and the second surface of the elastomer layer. And a surface layer.
The porous stretchable film of the present invention includes a band-shaped first region extending along the surface direction of the porous stretchable film, and the surface direction of the porous stretchable film that is adjacent to the first region and is less likely to stretch than the first region. And second strip-shaped regions extending along the line.

FIG. 1 is a photograph of an example of the porous stretchable film of the present invention as viewed from above, and FIG. 2 is an enlarged photograph of the porous stretchable film of FIG.
The porous stretchable film 10 includes an elastomer layer, a first surface layer provided on the first surface of the elastomer layer, and a second surface layer (hereinafter referred to as a first surface layer provided on the second surface of the elastomer layer). The surface layer and the second surface layer are collectively referred to simply as a surface layer.). Illustration of the cross section of the porous stretchable film 10 is omitted.

In the porous stretchable film 10, a strip-shaped first region 11 extending in the MD and a strip-shaped second region 12 extending in the MD are alternately formed in a TD to form a striped pattern.
The through holes 13 are formed at equal intervals in the length direction of each first region 11, and are arranged in a staggered manner in the entire porous stretchable film 10.
In FIGS. 1 and 2, since the background is black, the first region 11 appears as an opaque white portion, the second region 12 appears as a transparent gray portion, and the through hole 13 as a black portion. appear.

(Elastomer layer)
The elastomer layer is a layer that imparts stretchability to the porous stretchable film.
The elastomer layer may be a single layer or a multilayer.

The elastomer layer includes a thermoplastic elastomer.
The elastomer layer may contain other components as required within a range not impairing the effects of the present invention.

Thermoplastic elastomer:
Examples of the thermoplastic elastomer include olefin-based thermoplastic elastomers, styrene-based thermoplastic elastomers, urethane-based thermoplastic elastomers, and polyester-based thermoplastic elastomers. When the thermoplastic resin in the surface layer is an olefin resin, an olefin thermoplastic elastomer is preferable from the viewpoint of compatibility.

A thermoplastic elastomer consists of a hard segment and a soft segment.
Examples of the hard segment of the olefinic thermoplastic elastomer include polyethylene and polypropylene. Examples of the soft segment of the olefin thermoplastic elastomer include ethylene propylene rubber (EPDM, EPM, EEM), hydrogenated (styrene) butadiene rubber, polyoctene, and the like.
Examples of the hard segment of the styrenic thermoplastic elastomer include polystyrene. Examples of the soft segment of the styrenic thermoplastic elastomer include polybutadiene, polyisoprene, polyethylene, and hydrogenated products thereof.

As a commercial item of an olefin type thermoplastic elastomer, the following are mentioned, for example.
Vistamaxx (registered trademark) 6102 (manufactured by ExxonMobil, propylene-ethylene copolymer, glass transition temperature: -32 ° C., ethylene unit content: 16% by mass),
Vistamaxx (registered trademark) 3020 (manufactured by ExxonMobil, propylene-ethylene copolymer, glass transition temperature: -26 ° C, ethylene unit content: 11% by mass),
Infuse (registered trademark) 9107 (manufactured by Dow Chemical Co., ethylene-octene copolymer, glass transition temperature: -62 ° C),
Infuse (registered trademark) 9507 (manufactured by Dow Chemical Co., ethylene-octene copolymer, glass transition temperature: -62 ° C), and the like.
A thermoplastic elastomer may be used individually by 1 type, and may use 2 or more types together.

Other ingredients:
Other components include thermoplastic resins (excluding thermoplastic elastomers), inorganic fillers, amide antiblocking agents (such as stearic acid amide), antioxidants, weather stabilizers, antistatic agents, antifogging agents, Examples include metal soaps, waxes, fungicides, antibacterial agents, nucleating agents, flame retardants, and lubricants.

Examples of the thermoplastic resin include olefin resins such as polyethylene and polypropylene.
Examples of the inorganic filler include calcium carbonate, zeolite, silica and the like.
Other components may be masterbatched and added to the elastomer layer forming material.
Other components may be used alone or in combination of two or more.

Ratio of each component in the elastomer layer:
The proportion of the thermoplastic elastomer is preferably 70% by mass or more, more preferably 80% by mass or more, out of 100% by mass of the elastomer layer. If the ratio of the thermoplastic elastomer is not less than the lower limit of the above range, excellent stretchability can be easily obtained. The upper limit of the ratio of the thermoplastic elastomer is 100% by mass.

  The proportion of the thermoplastic resin (excluding the thermoplastic elastomer) is preferably 0 to 20% by mass in 100% by mass of the total amount of the resin components in the elastomer layer. If the ratio of the thermoplastic resin is not more than the upper limit of the above range, excellent stretchability is easily obtained.

Elastomer layer thickness:
The thickness of the elastomer layer is preferably 5 to 50 μm, more preferably 10 to 45 μm, and still more preferably 15 to 40 μm. If the thickness of the elastomer layer is equal to or greater than the lower limit of the above range, the stretchable force of the porous stretchable film can be sufficiently obtained, and thus the shrinkage force when the porous stretchable film is applied to a product can be sufficiently obtained. If the thickness of the elastomer layer is less than or equal to the upper limit of the above range, it can be suppressed that the stretchable force of the porous stretchable film becomes excessive and the shrinkage force when applied to a product becomes too strong.
When the elastomer layer is a multilayer, the thickness of the elastomer layer is the thickness of the entire multilayer.

(Surface layer)
The surface layer is a layer that suppresses the occurrence of blocking of the porous stretchable film.
The surface layer is provided on one or both of the first surface and the second surface of the elastomer layer. In view of sufficiently suppressing the occurrence of blocking of the porous stretchable film, it is preferably provided on both the first surface and the second surface of the elastomer layer. The first surface layer provided on the first surface of the elastomer layer and the second surface layer provided on the second surface may be the same type of surface layer or different types of surface layers. May be.

The surface layer contains a thermoplastic resin (excluding the thermoplastic elastomer).
The surface layer preferably further contains an inorganic filler.
The surface layer may contain other components as necessary within a range not impairing the effects of the present invention.

Thermoplastic resin:
As the thermoplastic resin, those having compatibility with the thermoplastic elastomer in the elastomer layer are preferable. When the thermoplastic elastomer in the elastomer layer is an olefinic thermoplastic elastomer, an olefinic resin such as polyethylene or polypropylene is preferable from the viewpoint of compatibility.
A thermoplastic resin may be used individually by 1 type, and may use 2 or more types together.

Inorganic filler:
The inorganic filler is a component that imparts slipperiness to the surface of the surface layer and further suppresses the occurrence of blocking of the porous stretchable film.
Examples of the inorganic filler include calcium carbonate, zeolite, silica and the like.
An inorganic filler may be used individually by 1 type, and may use 2 or more types together.

The average particle diameter of the inorganic filler is preferably 2 to 10 μm. If the average particle diameter of the inorganic filler is equal to or greater than the lower limit of the above range, the slip property is improved. If the average particle diameter of the inorganic filler is not more than the upper limit of the above range, the touch is improved.
The average particle diameter of the inorganic filler is an average value of the particle diameters of 10 particles randomly selected in the scanning electron microscope image.

  The inorganic filler may be masterbatched and added to the surface layer forming material. Further, the master batch of the inorganic filler may be used as the surface layer forming material as it is. Examples of the master batch base resin include olefin resins such as polyethylene and polypropylene, and polyethylene is preferred from the viewpoint of versatility.

As a commercial item of the master batch of an inorganic filler, the following are mentioned, for example.
TEP 1HC783 WHT (manufactured by HANIL TOYO, calcium carbonate (average particle size: 5 μm, content: 50% by mass), base resin: polyethylene),
PE180NLD2 (Samplac Industrial Co., Ltd., calcium carbonate (average particle size: 5 μm, content: 50% by mass), base resin: polyethylene),
Kinoplus EMB-7A2806AC (manufactured by Sumika Color Co., Ltd., zeolite (average particle size: 2 μm, content: 20% by mass), base resin: polyethylene),
Smooth Master S (manufactured by Dainichi Seika Kogyo Co., Ltd., silica (average particle size 10 μm, content: 20% by mass), base resin: polyethylene) and the like.
A master batch may be used individually by 1 type, and may use 2 or more types together.

Other ingredients:
Other components include amide antiblocking agents (stearic acid amide, etc.), antioxidants, weathering stabilizers, antistatic agents, antifogging agents, metal soaps, waxes, fungicides, antibacterial agents, nucleating agents, Examples include flame retardants and lubricants.

Other components may be masterbatched and added to the surface layer forming material.
Examples of the master batch of the amide antiblocking agent include Riquet Master EXR-040 (manufactured by Riken Vitamin Co., Ltd., stearic acid amide-containing master batch (stearic acid amide content: 15% by mass), base resin: polyethylene).
Other components may be used alone or in combination of two or more.

Ratio of each component in the surface layer:
The proportion of the thermoplastic resin is preferably 10 to 90 mass%, more preferably 15 to 85 mass%, out of 100 mass% of the surface layer. If the ratio of the thermoplastic resin is not less than the lower limit of the above range, the surface layer can be formed.
The thermoplastic resin includes a masterbatch base resin.

  The proportion of the inorganic filler is preferably 10 to 90% by mass and more preferably 15 to 85% by mass in 100% by mass of the surface layer. When the proportion of the inorganic filler is equal to or greater than the lower limit of the above range, occurrence of blocking of the porous stretchable film is sufficiently suppressed. In addition, the surface layer is easily destroyed during gear stretching described later. If the ratio of the inorganic filler is not more than the upper limit of the above range, the surface layer can be formed.

Surface layer thickness:
The thickness of the surface layer is preferably 0.5 to 10 μm, more preferably 2 to 9 μm, and even more preferably 3 to 8 μm. If the thickness of the surface layer is not less than the lower limit of the above range, the occurrence of blocking of the porous stretchable film can be sufficiently suppressed. If the thickness of the surface layer is not more than the upper limit of the above range, the stretchability of the porous stretchable film can be sufficiently obtained. The first surface layer provided on the first surface of the elastomer layer and the second surface layer provided on the second surface may have the same thickness or different thicknesses.

(First region and second region)
The first region is a portion in which the surface layer is stretched and broken when the non-porous stretch film is stretched in a stripe shape by gear stretching described later.
The second region is a portion where the surface layer was not stretched and broken when the non-porous stretch film was stretched in a stripe shape by gear stretching described later.

In the first region, although the surface layer remains, since the surface layer is stretched and broken, the stretchability is close to that of the elastomer layer alone.
In the second region, the surface layer is not stretched and broken, that is, the surface layer having no elasticity remains on the surface of the elastomer layer, so that the elasticity is slightly insufficient.
Therefore, the second region is less likely to extend than the first region, and the first region is easier to extend than the second region.

The following average expansion ratio of the first region is preferably 1.51 to 5.00 times, and more preferably 1.60 to 4.50 times.
The following average stretching magnification of the second region is preferably 1.01-1.50 times, and more preferably 1.01-1.48 times.

Average stretch ratio:
A strip-shaped test piece of 50 mm in the longitudinal direction of the first region and the second region and 100 mm in a direction orthogonal to the longitudinal direction is cut out from the porous stretchable film. The test piece is fixed to the grip of the test apparatus so that the distance between the grips is 30 mm. The test piece is stretched in the direction orthogonal to the longitudinal direction of the first region and the second region at a speed of 100 mm / min so that the elongation calculated by the following formula (I) is 80%. The expansion ratio (times) is calculated from the following formula (III). Twelve stretch magnifications selected at random in both the first region and the second region are calculated, and an average value is obtained.
Elongation = (L1-L0) / L0 × 100 (I)
Elongation magnification = R1 / R0 (III)
However, L0 is the distance (mm) between grips before extending | stretching, L1 is the distance (mm) between grips after extending | stretching, and R0 is 1st area | region or 2nd before extending | stretching. R1 is a length (μm) in a direction perpendicular to the longitudinal direction of the first region or the second region after being stretched (μm). However, R0 and R1 are measured at the same place in the same region).

If the average stretch magnification of the second region is within the above range and the average stretch magnification of the first region is not less than the lower limit of the above range, the surface layer is destroyed when the porous stretchable film is stretched. The first area is preferentially expanded. For this reason, the stress applied to the periphery of the through hole is also reduced, and breakage at the time of extension is unlikely to occur. Moreover, since the 2nd area | region where the surface layer is not destroyed has high rigidity and the quantity which deform | transforms when extending | stretching a porous elastic film is small, a fracture | rupture does not occur easily.
If the average expansion ratio of the first region is equal to or less than the upper limit of the above range, appropriate stretchability can be obtained.

  The width of the first region and the width of the second region before stretching are not particularly limited, and may be appropriately determined according to stretchability, breathability, flexibility, and the like required for the porous stretchable film.

(Through hole)
The through hole may be formed in the first region or may be formed in the second region.
Regardless of whether the through hole is formed in the first region or the second region, breakage caused by the through hole is unlikely to occur when the porous stretchable film is stretched. The first region extends with low stress because the surface layer is broken. Therefore, the stress applied to the periphery of the through hole is also reduced, and breakage at the time of extension is unlikely to occur. On the other hand, in the second region, since the surface layer is not broken, the rigidity is high and deformation at the time of expansion hardly occurs, so that the second region hardly breaks.
Most of the through holes are formed in the first region when the porous stretchable film is manufactured by the manufacturing method of the present invention described later.

0.1-1.5 mm < ² > is preferable and, as for the average value of the opening area of a through-hole, 0.2-1.4 mm < ² > is more preferable. When the average value of the opening area of the through holes is equal to or greater than the lower limit of the above range, the air permeability of the porous stretchable film is further improved. If the average value of the opening area of the through holes is equal to or less than the upper limit of the above range, breakage caused by the through holes is less likely to occur when the porous stretchable film is stretched.
The average value of the opening area of a through-hole is an average value of the opening area of 50 through-holes selected at random.

The number of through holes is preferably 1 to 20 and more preferably 3 to 15 per 1 cm ^{2 of the} porous stretchable film. If the number of through-holes is not less than the lower limit of the above range, the air permeability of the porous stretchable film is further improved. If the number of through holes is equal to or less than the upper limit of the above range, the stretchability of the porous stretchable film is unlikely to decrease.

(Thickness of porous stretch film)
The thickness of the porous stretchable film is preferably 6 to 70 μm, more preferably 10 to 60 μm, and still more preferably 20 to 55 μm. If the thickness of the porous stretchable film is not less than the lower limit of the above range, the stretchability of the porous stretchable film will be sufficiently high. If the thickness of the porous stretchable film is not more than the upper limit of the above range, the stretchability of the porous stretchable film will not be excessive.

(Function and effect)
In the porous stretchable film of the present invention described above, since the surface layer is provided on one or both of the first surface and the second surface of the elastomer layer, occurrence of blocking is suppressed.
Moreover, in the porous stretchable film of the present invention described above, since a plurality of through holes are formed, air permeability is good.
Moreover, in the porous stretchable film of the present invention described above, the strip-shaped first region extending along the surface direction of the porous stretchable film, the first region adjacent to the first region, and extending more than the first region. Since it has the belt-like second regions extending along the surface direction of the porous stretchable film alternately, it is difficult to break when stretched, and the stretchability is not easily lowered. That is, as shown in FIG. 3, when the porous stretchable film 10 is stretched to TD, the first region 11 that is easier to stretch than the second region 12 is preferentially stretched. Since the first region 11 expands with low stress, and the second region 12 has high rigidity and is difficult to extend, breakage caused by the through hole 13 is unlikely to occur. Therefore, the stretchability of the porous stretchable film 10 is not easily lowered. On the other hand, when a through-hole is formed in a conventional stretchable film that has a uniform stretchability over the entire surface and has a non-stretchable surface layer, the stretchability is slightly insufficient. At this time, since the film is not sufficiently stretched, stress is concentrated in the through hole, and the film is easily broken from the through hole.

(Other embodiments)
The porous stretchable film of the present invention has an elastomer layer and a surface layer provided on one or both of the first surface and the second surface of the elastomer layer, and has a plurality of through-holes that are the same. As long as it has alternating strip-shaped first regions and strip-shaped second regions that are less likely to extend than the first region, it is not limited to the porous stretchable film 10 of the illustrated example.
For example, the surface layer may be provided on only one of the first surface and the second surface of the elastomer layer.
The through hole may be formed only in the first region or only in the second region, or may be formed in both the first region and the second region.
The arrangement of the through holes is not limited to the staggered arrangement, and may be a lattice arrangement or a random arrangement.

<Method for producing porous stretch film>
The manufacturing method of the porous elastic film of this invention is a method which has the following process (c) and process (d). The manufacturing method of the porous elastic film of this invention may have the following process (a) and process (b) as needed.

Step (a): A step of preparing an elastomer layer forming material and a surface layer forming material.
Step (b): A step of producing a non-porous stretch film having an elastomer layer and a surface layer provided on one or both of the first surface and the second surface of the elastomer layer.
Step (c): A step of forming a plurality of depressions interspersed in the non-porous stretch film by embossing the non-porous stretch film.
Process (d): The process of obtaining the porous elastic film of this invention by carrying out the gear extending | stretching which mentions the embossed non-porous elastic film later.

(Process (a))
When the material for forming the elastomer layer is composed only of the thermoplastic elastomer, the thermoplastic elastomer is used as the material for forming the elastomer layer.
When the elastomer layer forming material contains a thermoplastic elastomer and other components, the respective components are mixed to prepare the elastomer layer forming material. Other components may be masterbatched and added to the elastomer layer forming material.

When the surface layer forming material is made of only a thermoplastic resin, the thermoplastic resin is used as the surface layer forming material.
When the surface layer forming material includes a thermoplastic resin, an inorganic filler, and other components as required, each component is mixed to prepare the surface layer forming material. The inorganic filler and other components may be masterbatched and added to the surface layer forming material. Moreover, when a masterbatch contains a thermoplastic resin, it is good also considering a masterbatch as a material for surface layer formation.

Examples of the mixing method of each component include a method using various mixers such as a Henschel mixer, a tumbler mixer, a Banbury mixer, and a kneader.
The mixing order of each component is not particularly limited. For example, all components may be mixed at once.
The first surface layer forming material and the second surface layer forming material may be the same material or different materials.

(Process (b))
An elastomer layer forming material and a surface layer forming material are molded by a known molding method, and an elastomer layer, and a surface layer provided on one or both of the first surface and the second surface of the elastomer layer, To obtain a non-porous stretch film.
Examples of the molding method include a cast film process method and an inflation method, and the cast film process method is preferable from the viewpoint of productivity.

FIG. 4 is a cross-sectional view showing an example of a non-porous stretch film.
The non-porous stretch film 10 ′ includes an elastomer layer 14, a first surface layer 15 provided on the first surface of the elastomer layer 14, and a second surface layer provided on the second surface of the elastomer layer 14. 16.

The permanent set of the non-porous stretch film is preferably 15% or more, and more preferably 20% or more.
Permanent strain of non-porous stretch film:
A strip-shaped test piece of 50 mm in the machine direction (MD) and 200 mm in the width direction (TD) is cut out from the non-porous stretch film. The test piece is fixed to the grip of the test apparatus so that the distance between the grips is 100 mm. The test piece is stretched at TD at a speed of 100 mm / min so that the elongation calculated by the following formula (I) is 80%, and then the test piece is immediately contracted at the same speed. Permanent strain (%) is calculated from the following formula (II).
Elongation = (L1-L0) / L0 × 100 (I)
Permanent strain = (L2-L0) / (L1-L0) × 100 (II)
However, L0 is the distance (mm) between grips before extending | stretching, L1 is the distance (mm) between grips after extending | stretching, L2 is the load (N / This is the distance (mm) between grips when (50 mm) becomes zero.

  If the permanent strain of the non-porous stretch film is equal to or greater than the lower limit of the above range, the shrinkage force of the porous stretch film is too large (the permanent strain is too small) after the through hole is formed by gear stretching in the step (d). ), The through-holes are not blocked by the shrinkage of the porous stretchable film, and sufficient air permeability can be secured.

(Process (c))
By embossing the non-porous stretch film, a plurality of depressions scattered in the non-porous stretch film are formed. A hollow part is a part used as a through-hole when gear extending | stretching in a process (d).

Examples of the embossing method include a roll press method, a differential pressure method, and a high pressure jet method.
The roll press method is a method in which a pin embossing roll having a large number of protruding pins on the peripheral surface and an anvil roll corresponding to the pin embossing roll are arranged opposite to each other, and a non-porous stretch film is passed between these rolls.
In the differential pressure method, the non-porous stretch film is softened near the softening temperature and is positioned on the upper surface of the support having a large number of apertures, and is sucked from the lower side of the support or is pneumatically applied from the upper surface of the support. Or pressurizing.
The high-pressure jet method is a method in which a non-porous stretch film is deformed by a high-pressure jet of liquid ejected from a number of high-pressure liquid jet nozzles.

The indented portion has a depth that does not penetrate the non-porous stretch film. When many penetrating hollow parts are generated, the non-porous stretch film may be broken by the processing due to gear stretching in the step (d).
The depth of the recess can be adjusted by, for example, the height of the protruding pin provided on the pin embossing roll.
What is necessary is just to determine suitably the shape, number, arrangement | positioning, etc. of the protrusion pin of a pin embossing roll according to the shape, number, arrangement | positioning, etc. of the through-hole of a porous elastic film.

(Process (d))
By stretching the embossed non-porous stretch film with a gear, the non-porous stretch film is stretched in a stripe shape to obtain the porous stretch film of the present invention having first regions and second regions alternately.
Specifically, the gear extension is performed as follows.

  A first shaping roll having a plurality of ridges extending in the circumferential direction or the axial direction, and a second shaping roll having a plurality of ridges extending in the same direction as the ridges of the first shaping roll. The protrusions of one shaping roll and the grooves between the protrusions of the other shaping roll are arranged to face each other.

FIG. 5 is an enlarged view showing an example of a pair of shaping rolls.
A first shaping roll 20 having a plurality of ridges 24 extending in the circumferential direction on the circumferential surface of the cylindrical roll body 22 and a plurality of ridges 34 extending in the circumferential direction on the circumferential surface of the cylindrical roll body 32. The second shaping roll 30 has the first shaping roll 20 so that the ridges 24 of the first shaping roll 20 and the grooves 36 between the ridges 34 of the second shaping roll 30 mesh with each other. The grooves 26 between the ridges 24 of the shape roll 20 and the ridges 34 of the second shaping roll 30 are arranged to face each other with a predetermined clearance so as to mesh with each other.

FIG. 6 is an enlarged view showing another example of a pair of shaping rolls.
A first shaping roll 40 having a plurality of ridges 44 extending in the axial direction on the peripheral surface of the cylindrical roll body 42 and a plurality of ridges 54 extending in the axial direction on the peripheral surface of the cylindrical roll body 52. The second shaping roll 50 has the first shaping roll 40 and the first shaping roll 40 so that the projections 44 and the grooves 56 between the projections 54 of the second shaping roll 50 mesh with each other. The grooves 46 between the ridges 44 of the shape roll 40 and the ridges 54 of the second shaping roll 50 are arranged to face each other with a predetermined clearance so as to mesh with each other.

  By passing the embossed non-porous stretch film between the first shaping roll and the second shaping roll while rotating the first shaping roll and the second shaping roll, While forming the 1st area | region extended between the protruding item | line of the 1st shaping roll and the protruding item | line of the 2nd shaping roll, and the 2nd area | region which was not extended | stretched, the hollow of a non-porous stretch film The part is stretched to form a through hole.

According to the pair of shaping rolls in FIG. 5, the non-porous stretch film passing between them is pushed downward by the projections 24 of the first shaping roll 20 and the projections of the second shaping roll 30. 34 is pushed upward. Therefore, the non-porous stretch film is partially stretched in the up and down diagonal direction by the ridges 24 of the adjacent first shaping rolls 20 and the ridges 34 of the second shaping rolls 30, and the first region Become. At this time, if a hollow portion exists in the stretched portion of the non-porous stretch film, the hollow portion is thin and thus is cleaved by stretching to form a through hole. On the other hand, in the non-porous stretch film, the top portion of the ridges 24 of the first shaping roll 20 or the portion in contact with the top of the ridges 34 of the second shaping roll 30 is not stretched, and thus becomes the second region. .
Since the direction in which the non-porous stretch film is partially stretched by the pair of shaping rolls in FIG. 5 is TD, the gear stretching by the pair of shaping rolls in FIG. 5 is also called TD gear stretching. According to the TD gear extension, as shown in FIGS. 1 and 2, strip-shaped first regions 11 extending in the MD and strip-shaped second regions 12 extending in the MD are alternately formed in the TD.

According to the pair of shaping rolls in FIG. 6, the non-porous stretch film passing between them is pushed downward by the projection 44 of the first shaping roll 40 and the projection of the second shaping roll 50. 54 is pushed upward. Therefore, the non-porous stretch film is partially stretched in the up and down diagonal direction by the ridges 44 of the adjacent first shaping roll 40 and the ridges 54 of the second shaping roll 50, and the first region Become. At this time, if a hollow portion exists in the stretched portion of the non-porous stretch film, the hollow portion is thin and thus is cleaved by stretching to form a through hole. On the other hand, in the non-porous stretch film, the top portion of the ridge 44 of the first shaping roll 40 or the portion in contact with the top of the ridge 54 of the second shaping roll 50 is not stretched, and thus becomes the second region. .
Since the direction in which the non-porous stretch film is partially stretched by the pair of shaping rolls in FIG. 6 is MD, the gear stretching by the pair of shaping rolls in FIG. 6 is also referred to as MD gear stretching. According to the MD gear extension, the band-shaped first regions extending in the TD and the band-shaped second regions extending in the TD are alternately formed in the MD.

  When stretching an ordinary film as a whole, if the film is stretched beyond the elastic limit of the film, an irreversible change occurs in the film. In many cases, irreversible changes in the film are accompanied by a change in color tone (whitening) and a change in size (increase or decrease in length or width). This dimensional change is called permanent set. A film in which permanent strain is generated by stretching exceeding the elastic limit behaves elastically within the range of (stretching ratio−permanent strain). For example, when a film having a length of 100 mm is stretched to 200 mm (stretching ratio: 2 times) and a permanent strain of 30% is generated, the length of the film after stretching is 130 mm, and 100% -30% = 70% That is, it has an elastic behavior within the range of 130 mm to 200 mm. Here, the elastic behavior refers to the property of returning to the original dimension again when the force is removed even if the dimension is changed by applying a force. The stretched film has an elastic behavior within a range of 100% to 154% (130 mm / 130 mm to 200 mm / 130 mm) because the length has changed from 100 mm before stretching to 130 mm (elasticity). Have).

In gear stretching, the non-porous stretch film is stretched partially beyond its elastic limit. A non-porous stretch film stretched partially beyond its elastic limit by gear stretching causes a change in color tone. That is, the first region of the white portion in FIG. 1 and FIG. 2 is a region that is stretched beyond the elastic limit and generates permanent set, and as a result, has elasticity within a certain range. This color tone change indicates that an irreversible change occurs in the structure of the non-porous stretch film. For example, when the non-porous stretch film has a surface layer containing a thermoplastic resin (polyethylene, polypropylene, etc.) that is a non-elastomer, the surface layer is stretched and broken by stretching exceeding the elastic limit. In the surface layer that has been stretched and broken, voids such as cracks and fine holes are generated inside. This void causes irregular reflection of light entering the surface layer, and appears white in appearance. Further, the destroyed surface layer loses its inherent mechanical strength. Along with this, the first region is released from the restraint of the surface layer, and its inherent elasticity (stretchability by the elastomer layer) is developed.
Note that the color tone does not change in the portion that is not stretched by the gear stretching, that is, the second region.

In gear stretching, the width W of the top of the ridge of the shaping roll, the height H of the ridge, the interval P between the tops of adjacent ridges, the ridge and the second shaping of the first shaping roll. The draw ratio can be adjusted by adjusting the engagement depth D of the roll with the ridges.
The calculation of the draw ratio in gear drawing can be easily calculated by the three square theorem from the drawing principle. For example, the interval between the tops of the ridges of the adjacent first shaping rolls and the tops of the ridges of the second shaping roll (the width of the stretched portion of the non-porous stretch film) is 1 mm, and the meshing depth is When it is √3 mm, the width of the stretched portion of the non-porous stretch film is 2 mm, and the stretch ratio is 2 times. Here, when the permanent set is 30%, the width of the stretched portion changes from 1 mm before stretching to 1.3 mm.

The width | variety of a 1st area | region and the width | variety and length of a 2nd area | region are not specifically limited, What is necessary is just to determine suitably according to the intended purpose etc. of a porous elastic film.
The area of the opening part of a through-hole can be suitably adjusted with the magnitude | size of the protrusion pin of a pin embossing roll, a shape, and a draw ratio.

(Function and effect)
In the method for producing a porous stretch film of the present invention described above, a non-porous stretch film having a surface layer provided on one or both of the first surface and the second surface of an elastomer layer is embossed. By processing, a plurality of depressions scattered in the non-porous stretch film are formed, and the embossed non-porous stretch film is subjected to the above-described gear stretching, so the width of the first region and the second region And a porous stretchable film having through holes formed therein. That is, it is possible to produce a porous stretchable film in which the occurrence of blocking is suppressed, the air permeability is good, and the stretchability is difficult to break when stretched.

(Other embodiments)
The porous stretchable film of the present invention may be manufactured by a manufacturing method other than a method combining embossing and gear stretching.
For example, a non-embossed non-porous stretch film is gear stretched to form a first region and a second region, and then a through hole is formed by a known opening means (slitting, hot pin melt, etc.) Also good.

<Composite sheet>
The composite sheet of the present invention has a layer made of the porous stretchable film of the present invention and a layer made of a nonwoven fabric.

(Nonwoven fabric)
Examples of the nonwoven fabric include spunbond nonwoven fabric, melt blown nonwoven fabric, flash spun nonwoven fabric, chemical bond nonwoven fabric, thermal bond nonwoven fabric, wet nonwoven fabric, and dry nonwoven fabric.
Examples of non-woven fibers include synthetic fibers (polypropylene fibers, polyamide fibers, polyester fibers, etc.), natural fibers (cotton, silk), semi-synthetic fibers (rayon fibers, acetate fibers, etc.) and the like.
The nonwoven fabric may be subjected to elongation imparting processing (softening processing, pleating processing, shrinking processing, shrinking processing, etc.).

(Production method of composite sheet)
A composite sheet is manufactured by joining and laminating the porous stretchable film of the present invention and a nonwoven fabric, for example.
Examples of the bonding method include a hot press method, a hot embossing bonding method, bonding with a hot melt adhesive, an ultrasonic bonding method, and a high frequency bonding method.

(Function and effect)
In the composite sheet of the present invention described above, since it has a layer made of the porous stretchable film of the present invention, occurrence of blocking due to the layer made of the porous stretchable film is suppressed, air permeability is good, and when stretched A layer made of a porous stretchable film is difficult to break and stretchability is unlikely to decrease.

(Other embodiments)
The composite sheet of the present invention only needs to have a layer composed of the porous stretchable film of the present invention and a layer composed of a nonwoven fabric, and consists of only a layer composed of the porous stretchable film of the present invention and a layer composed of the nonwoven fabric. There is no limitation.
For example, in the range which does not impair the effect of the composite sheet of this invention, you may have other layers other than the layer which consists of a porous elastic film of this invention, and a layer which consists of a nonwoven fabric.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by the following description.

<Measurement method, evaluation method>
(Thickness of each layer)
The thicknesses of the elastomer layer and the surface layer in the non-porous stretch film were determined by cross-sectional observation using a microscope.

(Permanent strain of stretchable film)
A strip-shaped test piece of 50 mm in the machine direction (MD) and 200 mm in the width direction (TD) was cut out from the stretchable film. The test piece was fixed to a gripping tool of a precision universal testing machine (manufactured by Shimadzu Corp., Autograph, material test operation software: TRAPEZIUM2) so that the distance between the gripping tools was 100 mm. The test piece was stretched at TD at a speed of 100 mm / min so that the elongation calculated by the following formula (I) was 80%, and then the test piece was immediately shrunk at the same speed. The permanent strain (%) at the first cycle was calculated from the following formula (II). Using the test piece used in the first cycle, the same operation was repeated once more to calculate the permanent strain (%) in the second cycle. The test was performed at 23 ° C. ± 2 ° C.
Elongation = (L1-L0) / L0 × 100 (I)
Permanent strain = (L2-L0) / (L1-L0) × 100 (II)
However, L0 is the distance (mm) between grips before extending | stretching, L1 is the distance (mm) between grips after extending | stretching, L2 is the load (N / This is the distance (mm) between grips when (50 mm) becomes zero.

(Breathability of stretchable film)
The stretchable film is measured according to JIS P 8117: 2009 (ISO 5636-5: 2003) using a Gurley densometer (G-B3C type, manufactured by Toyo Seiki Seisakusho Co., Ltd.), The air resistance (second / 100 mL) was used. The air resistance is an index of air permeability. The smaller the air resistance, the better the air permeability. The lower limit of detection is 1.4 seconds / 100 mL.

(Average expansion ratio of the first region and the second region)
A strip-shaped test piece of 50 mm in the machine direction (MD) and 100 mm in the width direction (TD) was cut out from the stretchable film. The test piece was fixed to a gripping tool of a precision universal testing machine (manufactured by Shimadzu Corporation, Autograph, material test operation software: TRAPEZIUM2) so that the distance between the gripping tools was 30 mm. The test piece was stretched at TD at a speed of 100 mm / min so that the elongation calculated by the following formula (I) was 80%. The expansion ratio (times) was calculated from the following formula (III). The stretch ratios at 12 points randomly selected in both the first region and the second region were calculated, and the average value was obtained. The test was performed at 23 ° C. ± 2 ° C.
Elongation = (L1-L0) / L0 × 100 (I)
Elongation magnification = R1 / R0 (III)
However, L0 is the distance (mm) between grips before extending | stretching, L1 is the distance (mm) between grips after extending | stretching, and R0 is 1st area | region or 2nd before extending | stretching. R1 is a length (μm) in a direction perpendicular to the longitudinal direction of the first region or the second region after being stretched (μm). However, R0 and R1 are measured at the same place in the same region).

<Raw material>
(Thermoplastic elastomer)
Vistamaxx (registered trademark) 6102 (manufactured by ExxonMobil, propylene-ethylene copolymer, glass transition temperature: -32 ° C., ethylene unit content: 16% by mass).
(Thermoplastic resin)
Sumikasen (registered trademark) CE3506 (manufactured by Sumitomo Chemical Co., Ltd., polyethylene).
(Master Badge)
TEP 1HC783 WHT (manufactured by HANIL TOYO, calcium carbonate (average particle size: 5 μm, content: 50 mass%), base resin: polyethylene).

(Elastomer layer forming material)
As the elastomer layer forming material (A-1), a thermoplastic elastomer was used as it was.
(Surface layer forming material)
As the surface layer forming material (B-1), a mixture composed of 85% by mass of polyethylene and 15% by mass of calcium carbonate, obtained by mixing a thermoplastic resin and a masterbatch with a tumbler mixer was used.
As the surface layer forming material (B-2), the master batch was used as it was.

<Manufacture of non-porous stretch film>
(Production Example 1)
Using an extruder equipped with a T die (manufactured by Sumitomo Heavy Industries Modern), the elastomer layer forming material (A-1) and the surface layer forming material (B-1) are extruded at 200 ° C., and cast film process By the method, a non-porous stretch film (F) having an elastomer layer, a first surface layer provided on the first surface of the elastomer layer, and a second surface layer provided on the second surface of the elastomer layer -1) was obtained. Tables 1 and 2 show the thickness of each layer.

(Production Example 2)
Except for changing the surface layer forming material (B-1) to the surface layer forming material (B-2), it was provided on the first surface of the elastomer layer and the elastomer layer in the same manner as in Production Example 1. A non-porous stretch film (F-2) having a first surface layer and a second surface layer provided on the second surface of the elastomer layer was obtained. Tables 3 and 4 show the thickness of each layer.

<Manufacture of porous stretch film or stretch film>
Example 1
The non-porous stretch film (F-1) was embossed by a roll press method.
The shape of the protruding pins provided on the pin embossing roll was a cylinder (diameter: 0.5 mm, height: 0.8 mm), and the protruding pins were arranged in a staggered manner with an interval of 3 mm.

The embossed non-porous stretch film was TD gear stretched using a pair of shaping rolls as shown in FIG. 5 to obtain a porous stretch film. The porous stretchable film was evaluated. The results are shown in Table 1.
In TD gear stretching, the width of the top of the ridge of the first shaping roll is 0.5 mm, the width of the top of the ridge of the second shaping roll is 0.5 mm, and the first shaping roll The spacing between the tops of the first shaping roll is 2.5 mm, the spacing between the tops of the first shaping roll is 2.5 mm, and the first shaping roll and the second shaping roll. The depth of meshing with the ridges was 2.9 mm (210%).

(Comparative Example 1)
An elastic film was obtained in the same manner as in Example 1 except that TD gear stretching was performed without embossing. The stretchable film was evaluated. The results are shown in Table 1.

(Comparative Example 2)
An elastic film was obtained in the same manner as in Example 1 except that embossing was performed and TD gear stretching was not performed. The stretchable film was evaluated. The results are shown in Table 1.

(Comparative Example 3)
The non-porous stretch film (F-1) was evaluated. The results are shown in Table 2.

(Comparative Example 4)
A slit was formed in the non-porous stretch film (F-1) by slitting to obtain a porous stretch film. The porous stretchable film was evaluated. The results are shown in Table 2.

(Comparative Example 5)
Through holes were formed in the non-porous stretch film (F-1) by hot pin melt to obtain a porous stretch film. The porous stretchable film was evaluated. The results are shown in Table 2.

(Example 2)
A porous stretchable film was obtained in the same manner as in Example 1 except that the non-porous stretchable film (F-2) was used. The porous stretchable film was evaluated. The results are shown in Table 3.
However, in the TD gear stretching, the meshing depth between the first shaping roll ridges and the second shaping roll ridges was 3.2 mm (240%).

(Comparative Example 6)
An elastic film was obtained in the same manner as in Example 2 except that TD gear stretching was performed without embossing. The stretchable film was evaluated. The results are shown in Table 3.

(Comparative Example 7)
An elastic film was obtained in the same manner as in Example 2 except that embossing was performed and TD gear stretching was not performed. The stretchable film was evaluated. The results are shown in Table 3.

(Comparative Example 8)
The non-porous stretch film (F-2) was evaluated. The results are shown in Table 4.

(Comparative Example 9)
A slit was formed in the non-porous stretch film (F-2) by slitting to obtain a porous stretch film. The porous stretchable film was evaluated. The results are shown in Table 4.

(Comparative Example 10)
Through holes were formed in the non-porous stretch film (F-2) by hot pin melt to obtain a porous stretch film. The porous stretchable film was evaluated. The results are shown in Table 4.

From the results of Examples 1 and 2, it can be seen that by embossing the non-porous stretch film and gear drawing, the first region and the second region are formed, and at the same time, the through hole is formed. The porous stretchable film having the first region and the second region and having through-holes has a small permanent strain (good stretchability) and a high breathability.
From the results of Comparative Examples 1 and 6, it can be seen that by stretching the gear without embossing the non-porous stretch film, the first region and the second region are formed, but the through hole is not formed.
From the results of Comparative Examples 2 and 7, it can be seen that the first region, the second region, and the through hole are not formed only by embossing the non-porous stretch film. It can also be seen that the permanent set is relatively large and the stretchability is insufficient.
From the results of Comparative Examples 3 and 8, it can be seen that the non-porous stretch film itself has a relatively large permanent strain (insufficient stretchability) and no breathability.
From the results of Comparative Examples 4, 5, 9, and 10, when slits and through holes are formed on a non-porous stretch film by slitting or hot melt, stress is concentrated on the slits and through holes when the stretch film is stretched. It can be seen that it breaks.

  The porous stretchable film and composite sheet of the present invention are suitably used in the hygiene field and the medical field. For example, it is used for elastic paper diaper tabs, training pants side panels, leg gathers, sanitary products, swimming pants, incontinence products, veterinary products, vantages, surgical gowns, surgical drapes, sterile covers, wipes, and the like.

10 porous stretch film,
10 'non-porous stretch film,
11 first region,
12 second region,
13 Through hole,
14 elastomer layer,
15 first surface layer,
16 second surface layer,
20 first shaping roll,
22 roll body,
24 ridges,
26 groove,
30 Second shaping roll,
32 roll body,
34 Projections
36 grooves,
40 first shaping roll,
42 roll body,
44 ridges,
46 groove,
50 second shaping roll,
52 roll body,
54 ridges,
56 Groove.

Claims (7)

An elastomer layer containing a thermoplastic elastomer, and a surface layer containing a thermoplastic resin (excluding the thermoplastic elastomer) provided on one or both of the first surface and the second surface of the elastomer layer. A porous stretch film having a plurality of through-holes,
The porous stretchable film has a strip-shaped first region extending along the surface direction of the porous stretchable film, and the surface direction of the porous stretchable film that is adjacent to the first region and is less likely to stretch than the first region. A porous stretchable film having alternating strip-like second regions extending along the axis. The porous stretchable film according to claim 1, wherein an average value of the opening areas of the through holes is 0.1 to 1.5 mm ² . The porous elastic film according to claim 1 or 2, wherein the number of through holes is 1 to 20 per 1 cm ² of the porous elastic film.   The porous stretchable film according to any one of claims 1 to 3, wherein the surface layer further contains an inorganic filler. A method for producing the porous stretchable film according to any one of claims 1 to 4,
An elastomer layer containing a thermoplastic elastomer, and a surface layer containing a thermoplastic resin (excluding the thermoplastic elastomer) provided on one or both of the first surface and the second surface of the elastomer layer. Embossing a non-porous stretch film having a step of forming a plurality of depressions scattered in the non-porous stretch film;
A first shaping roll having a plurality of ridges extending in the circumferential direction or the axial direction, and a second shaping roll having a plurality of ridges extending in the same direction as the ridges of the first shaping roll. The first shaping roll and the second shaping roll are rotated while facing and rotating so that the protrusions of one shaping roll and the grooves between the projections of the other shaping roll are engaged with each other. The first embossed non-porous stretch film is passed between the first shaping roll ridges and the second shaping roll ridges. And the step of forming the second region that has not been stretched and simultaneously extending the recess to form the through hole. The manufacturing method of the porous elastic film of Claim 5 whose following permanent strain of the said non-porous elastic film is 15% or more.
(Permanent strain of non-porous stretch film)
A strip-shaped test piece of 50 mm in the machine direction (MD) and 200 mm in the width direction (TD) is cut out from the non-porous stretch film. The test piece is fixed to the grip of the test apparatus so that the distance between the grips is 100 mm. The test piece is stretched at TD at a speed of 100 mm / min so that the elongation calculated by the following formula (I) is 80%, and then the test piece is immediately contracted at the same speed. Permanent strain (%) is calculated from the following formula (II).
Elongation = (L1-L0) / L0 × 100 (I)
Permanent strain = (L2-L0) / (L1-L0) × 100 (II)
However, L0 is the distance (mm) between grips before extending | stretching, L1 is the distance (mm) between grips after extending | stretching, L2 is the load (N / This is the distance (mm) between grips when (50 mm) becomes zero.   The composite sheet which has a layer which consists of a porous elastic film as described in any one of Claims 1-4, and a layer which consists of a nonwoven fabric.