阅读说明：本技术 非织造布层叠体以及伸缩性非织造布层叠体、纤维制品、吸收性物品和卫生口罩 (Nonwoven fabric laminate, stretchable nonwoven fabric laminate, fibrous product, absorbent article, and sanitary mask ) 是由 高久翔一 岛田幸一 本村茂之 于 2019-10-25 设计创作，主要内容包括：一种非织造布层叠体,其具有弹性非织造布以及伸长性纺粘非织造布,所述弹性非织造布包含40℃时的储能弹性模量E40与23℃时的储能弹性模量E23之比(E40/E23)为37％以上的α-烯烃共聚物,所述伸长性纺粘非织造布配置于所述弹性非织造布的至少一面侧。(A nonwoven fabric laminate comprising an elastic nonwoven fabric and an extensible spunbond nonwoven fabric, wherein the elastic nonwoven fabric comprises an alpha-olefin copolymer having a ratio of storage elastic modulus E40 at 40 ℃ to storage elastic modulus E23 at 23 ℃ (E40/E23) of 37% or more, and the extensible spunbond nonwoven fabric is disposed on at least one surface side of the elastic nonwoven fabric.)

1. A nonwoven fabric laminate having:

an elastic nonwoven fabric comprising a ratio of storage elastic modulus at 40 ℃ E40 to storage elastic modulus at 23 ℃ E23, that is, E40/E23 is an α -olefin copolymer of 37% or more; and

an extensible spunbonded nonwoven fabric which is disposed on at least one surface side of the elastic nonwoven fabric.

2. The nonwoven fabric laminate according to claim 1, wherein the α -olefin copolymer has a storage elastic modulus E23 at 23 ℃ of 30MPa or less.

3. The nonwoven fabric laminate of claim 1 or 2, the alpha-olefin copolymer comprising a copolymer of ethylene and propylene.

4. The nonwoven fabric laminate according to any one of claims 1 to 3, wherein the α -olefin copolymer has a tensile elastic modulus of 30MPa or less.

5. The nonwoven fabric laminate according to any one of claims 1 to 4, wherein the extensible spunbond nonwoven fabric is disposed on both sides of the elastic nonwoven fabric.

6. The nonwoven fabric laminate according to any one of claims 1 to 5, wherein the elongation at maximum load in at least one direction of the extensible spunbond nonwoven fabric is 45% or more.

7. A nonwoven fabric laminate according to any one of claims 1 to 6, the elastic nonwoven fabric being an elastic spunbond nonwoven fabric.

8. The nonwoven fabric laminate according to any one of claims 1 to 7, wherein the extensible spunbond nonwoven fabric is an extensible spunbond nonwoven fabric comprising a concentric core-sheath composite fiber, wherein a core part is a low-MFR olefin polymer having an MFR in a range of 1g/10 min to 1000g/10 min, a sheath part is a high-MFR olefin polymer having an MFR in a range of 1g/10 min to 1000g/10 min, and a difference between the MFR of the low-MFR olefin polymer and the MFR of the high-MFR olefin polymer is 1g/10 min or more.

9. The nonwoven fabric laminate according to any one of claims 1 to 8, wherein the extensible spunbond nonwoven fabric contains an olefin polymer composition comprising 80 to 99 mass% of a crystalline propylene polymer and 1 to 20 mass% of a high-density polyethylene.

10. The nonwoven fabric laminate according to any one of claims 1 to 9, wherein the elastic nonwoven fabric and the extensible spunbond nonwoven fabric have a mesh ratio of elastic nonwoven fabric to extensible spunbond nonwoven fabric in a range of 10:90 to 90: 10.

11. A stretchable nonwoven fabric laminate which is a stretched product of the nonwoven fabric laminate according to any one of claims 1 to 10.

12. A fibrous article comprising the nonwoven fabric laminate of any one of claims 1 to 10 or the stretchable nonwoven fabric laminate of claim 11.

13. An absorbent article comprising the nonwoven fabric laminate according to any one of claims 1 to 10 or the stretchable nonwoven fabric laminate according to claim 11.

14. A sanitary mask comprising the nonwoven fabric laminate according to any one of claims 1 to 10 or the stretchable nonwoven fabric laminate according to claim 11.

Technical Field

The present invention relates to a nonwoven fabric laminate, a stretchable nonwoven fabric laminate, a fibrous product, an absorbent article, and a sanitary mask.

Background

In recent years, nonwoven fabrics have been widely used in various applications because of their excellent air permeability and flexibility. Therefore, nonwoven fabrics are required to have various properties according to their applications and also to have improved properties.

For example, nonwoven fabrics used for sanitary materials such as disposable diapers and sanitary napkins, and base fabrics for wet-dressing materials are required to have water resistance and excellent moisture permeability. In addition, it is required to have elasticity and bulkiness depending on the place of use.

As one of methods for imparting stretchability to a nonwoven fabric, a method of using a thermoplastic elastomer as a raw material of a spunbond nonwoven fabric (for example, see patent document 1), a method of using a low-crystalline polypropylene (for example, see patent documents 2 and 3), and the like have been proposed.

Patent document 2 or patent document 3 proposes adding a highly crystalline polypropylene or a release agent to a low crystalline polypropylene in order to improve the stickiness of a spunbond nonwoven fabric. Patent document 4 discloses a laminate of a nonwoven fabric containing low-crystalline polypropylene and a mixed fiber spun-bonded nonwoven fabric containing long thermoplastic elastomer fibers and long thermoplastic resin fibers.

Patent document 1: japanese Kohyo publication Hei 7-503502

Patent document 2: japanese laid-open patent publication No. 2009-62667

Patent document 3: japanese laid-open patent publication No. 2009-79341

Patent document 4: international publication No. 2007/138733

Disclosure of Invention

Problems to be solved by the invention

In the method described in patent document 2 or patent document 3, in order to prevent adhesion to each rotating device in the apparatus and other portions in contact with the nonwoven fabric when producing the nonwoven fabric, it is necessary to increase the amount of the highly crystalline polypropylene or the release agent to be added to the low crystalline polypropylene, and as a result, the residual strain of the resulting spunbond nonwoven fabric tends to be large and the stretchability tends to be poor. In the method described in patent document 4, the stretchability is maintained by laminating a nonwoven fabric containing low-crystalline polypropylene and a hybrid spunbond nonwoven fabric, but further improvement in stretchability is strongly required.

In addition, in applications such as sanitary materials such as disposable diapers and sanitary napkins, and base cloths of wet dressings, it is required that the stress is small when the diaper is stretched so that the diaper can be worn with a weak force, and that the stress is large when the diaper is recovered so that the diaper does not move when worn. That is, in the above-mentioned applications, it is required to increase the value of the expansion and contraction characteristic (the ratio of stress at recovery time to stress at elongation time).

Further, in applications such as sanitary materials such as disposable diapers and sanitary napkins, and base cloths for wet dressing materials, it is required that the stress does not decrease when the fabric recovers within a range from room temperature (23 ℃) to body temperature (for example, within a range from 23 ℃ to 40 ℃), that is, the stress is maintained well. Thus, sanitary materials such as disposable diapers and sanitary napkins are difficult to move even when the temperature rises to the body temperature when worn.

In view of the above problems, an object of one embodiment of the present invention is to provide a nonwoven fabric laminate excellent in stretchability and stress retention, and a stretchable nonwoven fabric laminate, a fibrous product, an absorbent article, and a sanitary mask.

Means for solving the problems

Specific methods for solving the above problems include the following.

[1] A nonwoven fabric laminate having:

an elastic nonwoven fabric comprising an α -olefin copolymer having a ratio (E40/E23) of storage elastic modulus E40 at 40 ℃ to storage elastic modulus E23 at 23 ℃ of 37% or more; and

and an extensible spunbonded nonwoven fabric which is arranged on at least one surface side of the elastic nonwoven fabric.

[2] The nonwoven fabric laminate according to [1], wherein the α -olefin copolymer has a storage elastic modulus E23 at 23 ℃ of 30MPa or less.

[3] The nonwoven fabric laminate according to the above [1] or [2], wherein the above α -olefin copolymer comprises a copolymer of ethylene and propylene.

[4] The nonwoven fabric laminate according to any one of the above [1] to [3], wherein the α -olefin copolymer has a tensile elastic modulus of 30MPa or less.

[5] The nonwoven fabric laminate according to any one of the above [1] to [4], wherein the extensible spunbond nonwoven fabric is disposed on both sides of the elastic nonwoven fabric.

[6] The nonwoven fabric laminate according to any one of the above [1] to [5], wherein the extensible spunbond nonwoven fabric has a maximum load elongation of 45% or more in at least one direction.

[7] The nonwoven fabric laminate according to any one of the above [1] to [6], wherein the elastic nonwoven fabric is an elastic spunbond nonwoven fabric.

[8] The nonwoven fabric laminate according to any one of the above [1] to [7], wherein the extensible spunbond nonwoven fabric is an extensible spunbond nonwoven fabric comprising concentric core-sheath composite fibers, the core part of the concentric core-sheath composite fibers is an olefin polymer having a low MFR and a sheath part of the concentric core-sheath composite fibers is a high MFR, the MFR of the high MFR being in a range of 1g/10 min to 1000g/10 min, and the difference between the MFR of the low MFR and the MFR of the high MFR is 1g/10 min or more.

[9] The nonwoven fabric laminate according to any one of the above [1] to [8], wherein the extensible spunbond nonwoven fabric contains an olefin polymer composition containing 80 to 99 mass% of a crystalline propylene polymer and 1 to 20 mass% of a high-density polyethylene.

[10] The nonwoven fabric laminate according to any one of the above [1] to [9], wherein a mesh-weight ratio of the elastic nonwoven fabric to the extensible spunbond nonwoven fabric (elastic nonwoven fabric: extensible spunbond nonwoven fabric) is in a range of 10:90 to 90: 10.

[11] A stretchable nonwoven fabric laminate which is a stretched product of the nonwoven fabric laminate according to any one of the above [1] to [10 ].

[12] A fibrous product comprising the nonwoven fabric laminate according to any one of the above [1] to [10] or the stretchable nonwoven fabric laminate according to the above [11 ].

[13] An absorbent article comprising the nonwoven fabric laminate according to any one of the above [1] to [10] or the stretchable nonwoven fabric laminate according to the above [11 ].

[14] A sanitary mask comprising the nonwoven fabric laminate according to any one of the above [1] to [10] or the stretchable nonwoven fabric laminate according to the above [11 ].

ADVANTAGEOUS EFFECTS OF INVENTION

According to one embodiment of the present invention, a nonwoven fabric laminate excellent in stretch properties and stress retention, and a stretchable nonwoven fabric laminate, a fibrous product, an absorbent article, and a sanitary mask can be provided.

Drawings

Fig. 1 is a schematic view of a gear stretcher.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described. These descriptions and examples illustrate embodiments and do not limit the scope of embodiments.

In the present disclosure, in the numerical ranges described in the hierarchical order, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value described in another hierarchical order. In the numerical ranges disclosed in the present disclosure, the upper limit or the lower limit of the numerical range may be replaced with the values shown in the examples.

In the present disclosure, each ingredient may contain a plurality of corresponding substances. In the present disclosure, when the amount of each component in the composition is referred to, and when there are a plurality of substances corresponding to each component in the composition, the total amount of the plurality of substances present in the composition is meant unless otherwise specified.

The term "step" in the present disclosure is not limited to an independent step, and is included in the term as long as the purpose of the step can be achieved, even when the step cannot be clearly distinguished from other steps. In the present disclosure, the numerical range expressed by "to" means a range including numerical values described before and after "to" as the minimum value and the maximum value, respectively. In the present disclosure, the content of each component in the composition refers to the total amount of a plurality of substances present in the composition unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition.

Nonwoven fabric laminate

The nonwoven fabric laminate comprises an elastic nonwoven fabric comprising an alpha-olefin copolymer having a ratio (E40/E23) of storage elastic modulus E40 at 40 ℃ to storage elastic modulus E23 at 23 ℃ of 37% or more, and an extensible spunbonded nonwoven fabric disposed on at least one surface side of the elastic nonwoven fabric. The nonwoven fabric laminate may also comprise other layers.

The present disclosure relates to a nonwoven fabric laminate comprising an alpha-olefin copolymer as an elastic nonwoven fabric. Therefore, it is considered that a nonwoven fabric laminate excellent in stretch characteristics and stress maintenance can be obtained as compared with the case of using an elastic nonwoven fabric containing no α -olefin copolymer, for example, an elastic nonwoven fabric formed of a polypropylene homopolymer.

The alpha-olefin copolymer has a ratio (E40/E23) of the storage elastic modulus E40 at 40 ℃ to the storage elastic modulus E23 at 23 ℃ of 37% or more. That is, even under a temperature change environment (for example, 40 ℃ to 23 ℃), the decrease in elasticity in the elastic nonwoven fabric is easily suppressed. Therefore, it is considered that a nonwoven fabric laminate excellent in stress retention can be obtained.

The nonwoven fabric laminate of the present disclosure has an extensible spunbond nonwoven fabric disposed on at least one surface side of an elastic nonwoven fabric. This makes it easy to prevent the nonwoven fabric laminate from adhering to members such as various rotating devices in an apparatus used in an embossing step or the like, and is considered to be excellent in moldability and productivity. In addition, since the extensible spunbond nonwoven fabric has extensibility, the stretchability of the elastic nonwoven fabric due to excellent elasticity is easily maintained.

In the nonwoven fabric laminate, it is preferable to dispose an extensible spunbond nonwoven fabric on both sides of an elastic nonwoven fabric from the viewpoint of obtaining a nonwoven fabric laminate excellent in stretch properties and stress maintenance.

The basis weight of the nonwoven fabric laminate of the present disclosure is preferably 360g/m²Hereinafter, it is more preferably 240g/m²Hereinafter, it is more preferably 150g/m²Hereinafter, it is particularly preferably 120g/m²～15g/m²More preferably 80g/m²～20g/m²Extremely preferably 70g/m²～25g/m²。

The basis weight ratio (composition ratio) of the elastic nonwoven fabric to the extensible spunbond nonwoven fabric can be appropriately set according to various uses. For example, the basis weight ratio of the elastic nonwoven fabric to the extensible spunbond nonwoven fabric (elastic nonwoven fabric: extensible spunbond nonwoven fabric) is preferably in the range of 10:90 to 90:10, more preferably in the range of 20:80 to 80:20, and even more preferably in the range of 40:60 to 60: 40.

When the basis weight ratio of the elastic nonwoven fabric is 10 or more, the reduction in stretchability of the nonwoven fabric laminate tends to be suppressed. On the other hand, if the basis weight ratio of the elastic nonwoven fabric is 90 or less, the ratio of fibers constituting the elastic nonwoven fabric exposed to the surface beyond the extensible spunbond nonwoven fabric layer tends to decrease. Therefore, a nonwoven fabric laminate excellent in moldability and touch can be easily obtained.

When there are 2 or more elastic nonwoven fabrics (or extensible spunbond nonwoven fabrics), the basis weight of the elastic nonwoven fabrics (or extensible spunbond nonwoven fabrics) is a total of 2 or more.

Basis weight (g/m) of nonwoven fabric laminate²) The values obtained by measurement as described below were used. The basis weights of the elastic nonwoven fabric and the extensible spunbond nonwoven fabric were also determined by the same method.

6 test pieces having a flow direction (MD) of 200mm and a Cross Direction (CD) of 50mm were collected from the nonwoven fabric laminate. The acquisition field takes 3 arbitrary positions (6 positions in total) in both MD and CD. Subsequently, the mass (g) of each collected test piece was measured by using a dish electronic balance (manufactured by lapping industries), and the arithmetic mean of the masses of the test pieces was obtained. Converting the obtained arithmetic mean value into the value of 1m²The mass (g) of (1) is rounded off after the decimal point, and the number is defined as the apparent weight [ g/m ]²〕。

The maximum load elongation of the nonwoven fabric laminate in at least one direction is preferably 100% or more, more preferably 150% or more, and still more preferably 220% or more.

The maximum load elongation (%) of the nonwoven fabric laminate was measured as follows.

5 test pieces having a flow direction (MD) of 200mm and a Cross Direction (CD) of 50mm were collected from the nonwoven fabric laminate. The test piece was subjected to a tensile test using a constant-speed elongation type tensile tester under conditions of a tensile speed of 100 mm/min between chucks and a tensile speed of 100 mm/min. The maximum load [ N/50mm ] applied to the test piece was measured, and the elongation of the test piece in the maximum load [ (% ]) was measured. The arithmetic mean of 5 test pieces was obtained and set as the maximum load elongation.

[ elastic nonwoven Fabric ]

The elastic nonwoven fabric comprises an alpha-olefin copolymer having a ratio (E40/E23) of storage elastic modulus E40 at 40 ℃ to storage elastic modulus E23 at 23 ℃ of 37% or more.

The basis weight of the elastic nonwoven fabric is preferably 120g/m²Hereinafter, more preferably 80g/m²Hereinafter, it is more preferably 50g/m²Hereinafter, it is particularly preferably 40g/m²～2g/m²More preferably 30g/m²～5g/m²Extremely preferably 25g/m²～8g/m²。

The fiber diameter of the fibers constituting the elastic nonwoven fabric is preferably 50 μm or less, more preferably 40 μm or less, and further preferably 30 μm or less. The fibers constituting the elastic nonwoven fabric may have a fiber diameter of 1.0 μm or more.

The method for producing the elastic nonwoven fabric is not particularly limited, and various known methods can be applied. For example, the elastic nonwoven fabric may be an elastic nonwoven fabric produced by a method such as a spunbond method, a melt-blown method, or a flash-spun method. Among the above, from the viewpoint of making the fibers forming the nonwoven fabric long fibers, the elastic nonwoven fabric is preferably an elastic spunbond nonwoven fabric produced by a spunbond method.

(alpha-olefin copolymer)

The elastic nonwoven fabric comprises an alpha-olefin copolymer.

The α -olefin copolymer refers to a copolymer obtained by copolymerizing 2 or more kinds of copolymerization components having an α -olefin skeleton.

Examples of the copolymerization component having an α -olefin skeleton include α -olefins such as ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene.

Among the above, the α -olefin copolymer is preferably a copolymer containing ethylene and propylene as copolymerization components, in order to make a nonwoven fabric laminate having lower stress and more excellent stretchability, the copolymer containing ethylene (expressed as "C2" in tables 1 and 2) and propylene (expressed as "C3" in tables 1 and 2).

The content of the ethylene-derived constituent unit in the copolymer of ethylene and propylene (hereinafter, also simply referred to as "ethylene content") is preferably 1 to 50% by mass, more preferably 5 to 25% by mass, still more preferably 10 to 20% by mass, and particularly preferably 12 to 18% by mass.

The α -olefin copolymer may be any of an alternating copolymer, a graft copolymer, a block copolymer, and a random copolymer.

The ratio of the storage elastic modulus at 40 ℃ E40 to the storage elastic modulus at 23 ℃ E23 (E40/E23) of the α -olefin copolymer is 37% or more from the viewpoint of obtaining a nonwoven fabric laminate excellent in stress retention. The larger the value of the ratio (E40/E23) is, the more preferably 40% or more, the more preferably 45% or more, and the most preferably 50% or more. The upper limit of the above ratio (E40/E23) is not particularly limited, and may be 100% or less, 95% or less, or 90% or less.

Examples of the method for setting the storage elastic modulus ratio E40/E23 in the α -olefin copolymer to the above specific range include a method in which the α -olefin copolymer is a copolymer of ethylene and propylene.

The storage elastic modulus E23 of the α -olefin copolymer at 23 ℃ is preferably 30MPa or less, more preferably 22MPa or less, further preferably 20MPa or less, and particularly preferably 18MPa or less, from the viewpoint of making the nonwoven fabric laminate more excellent in stretchability.

The storage elastic modulus E40 at 40 ℃ of the α -olefin copolymer is preferably 10MPa or less, more preferably 9MPa or less, from the viewpoint of making the nonwoven fabric laminate lower in stress and more excellent in stretchability.

The α -olefin copolymer may have a storage elastic modulus E23 at 23 ℃ of 5MPa or more, or 10MPa or more.

The α -olefin copolymer may have a storage elastic modulus E40 at 40 ℃ of 3MPa or more, or 5MPa or more.

Each storage elastic modulus of the α -olefin copolymer is a value measured by the following apparatus and conditions.

Temperature: 23 ℃ or 40 DEG C

The device comprises the following steps: RSA-III (TA Instruments, manufactured by TA Instruments Co., Ltd.)

Deformation mode: stretching mode

Temperature range: -20 ℃ to 120 DEG C

Temperature rise rate: 2 ℃ per minute

Deformation frequency: 10Hz

Initial strain: 0.1 percent of

Measurement temperature interval: 0.3 deg.C

Environment: under nitrogen atmosphere

The density of the alpha-olefin copolymer (ASTM D1505) is preferably at 0.850g/cm³～0.950g/cm³More preferably in the range of 0.855g/cm³～0.900g/cm³Further preferably in the range of 0.860g/cm³～0.895g/cm³Within the range of (1).

The density of the α -olefin copolymer is a value obtained by measurement according to the density gradient method of JIS K7112 (1999).

The tensile elastic modulus of the α -olefin copolymer is preferably 30MPa or less, more preferably 20MPa or less, and even more preferably 15MPa or less, from the viewpoint of providing a nonwoven fabric laminate having more excellent stretchability. The upper limit of the tensile elastic modulus of the α -olefin copolymer is not particularly limited, and may be, for example, 5MPa or more.

The tensile modulus is a value obtained by measurement according to JIS K7161 (2011).

The molecular weight distribution (Mw/Mn) of the alpha-olefin copolymer is preferably 1.5 to 5.0. From the viewpoint of obtaining a fiber having good spinnability and particularly excellent fiber strength, Mw/Mn is more preferably 1.5 to 4.5.

The mass average molecular weight (Mw) and the number average molecular weight (Mn) of the α -olefin copolymer are values determined by GPC (gel permeation chromatography) and are values measured under the following conditions. The mass average molecular weight (Mw) is a mass average molecular weight in terms of polystyrene, and the molecular weight distribution (Mw/Mn) is a value calculated from the number average molecular weight (Mn) and the mass average molecular weight (Mw) measured in the same manner.

< GPC measurement Condition >

Column: TOSO GMHHR-H (S) HT

A detector: RI detector WATERS 150C for liquid chromatogram

Solvent: 1,2, 4-trichlorobenzene

Measuring temperature: 145 deg.C

Flow rate: 1.0 ml/min

Sample concentration: 2.2mg/ml

Sample introduction amount: 160 μ l

Standard curve: universal Call Calibration

And (3) analysis program: HT-GPC (Ver.1.0)

The Melt Flow Rate (MFR) of the α -olefin copolymer is not particularly limited, and is, for example, preferably 1g/10 min to 100g/10 min, more preferably 10g/10 min to 80g/10 min, still more preferably 15g/10 min to 70g/10 min, and particularly preferably 15g/10 min to 50g/10 min.

The melt flow rate of the alpha-olefin copolymer was measured under the conditions of ASTM D-1238, 230 ℃ and a load of 2.16 kg.

The α -olefin copolymer may be a synthetic product or a commercially available product.

When the α -olefin copolymer is a synthetic product, the α -olefin copolymer can be prepared as follows: the monomer is polymerized or copolymerized by a conventionally known polymerization method such as a gas phase method, a bulk method (bulk method), a slurry method, or a solution method in the presence of a conventionally known catalyst such as a ziegler-natta catalyst or a metallocene catalyst.

Commercially available products of the α -olefin copolymer include, for example, a tafmer (manufactured by Mitsui chemical Co., Ltd.), a Vistamaxx series (manufactured by Exxon Mobil chemical Co., Ltd.), and the like.

The composition of the α -olefin copolymer can be carried out by a conventionally known method (for example, IR analysis, NMR analysis, microanalysis, etc.).

The proportion of the α -olefin copolymer to the total amount of the elastic nonwoven fabric is preferably 90 to 100% by mass, and more preferably 98 to 100% by mass.

When the α -olefin copolymer contains a copolymer of ethylene and propylene, the proportion of the copolymer of ethylene and propylene to the total amount of the elastic nonwoven fabric is preferably 80 to 100% by mass, and more preferably 90 to 100% by mass, from the viewpoint of the stretch property in the nonwoven fabric laminate.

When the α -olefin copolymer is a copolymer of ethylene and propylene, the crystallinity of the α -olefin copolymer is preferably 1% to 15%, more preferably 1% to 13%, further preferably 2% to 10%, and particularly preferably 4% to 10%, from the viewpoint of stretch and contraction characteristics in the nonwoven fabric laminate.

The crystallinity of the α -olefin copolymer was calculated from the heat of fusion curve derived from melting of the main component in the melting endothermic curve obtained by holding at-100 ℃ for 5 minutes in a nitrogen atmosphere using a Differential Scanning Calorimeter (DSC) and then raising the temperature at 10 ℃/minute. Specifically, the melting heat curve derived from the melting of the main component in the melting endothermic curve obtained by holding 5mg of the sample at-100 ℃ for 5 minutes in a nitrogen atmosphere using a differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer Co., Ltd.), and then raising the temperature at 10 ℃/minute can be calculated by using the following formula.

Degree of crystallinity (. DELTA.H/. DELTA.H 0). times.100 (%)

In the formula, Δ H is the heat of fusion (J/g) determined from the heat of fusion curve derived from the melting of the main component of an α -olefin copolymer containing ethylene and propylene, and Δ H0 is the heat of fusion (J/g) of the complete crystal of the main component. That is, when the main component is ethylene, Δ H0 is 293J/g, and when the main component is propylene, Δ H0 is 210J/g.

When the α -olefin copolymer is a copolymer of ethylene and propylene, the melting point of the α -olefin may be 130 ℃ or lower, 115 ℃ or lower, 100 ℃ or lower, 40 ℃ to 85 ℃ or 40 ℃ to 60 ℃.

The melting point of the alpha-olefin copolymer is defined as: the peak top of the peak observed on the lowest temperature side of the melting endothermic curve obtained by holding at-100 ℃ for 5 minutes and then raising the temperature at 10 ℃/minute under a nitrogen atmosphere using a Differential Scanning Calorimeter (DSC). Specifically, the peak top of the peak observed on the lowest temperature side of the melting endothermic curve obtained by holding 5mg of the sample at-100 ℃ for 5 minutes in a nitrogen atmosphere using a differential scanning calorimeter (DSC-7 manufactured by Perkin Elmer Co., Ltd.), and then raising the temperature at 10 ℃/minute can be obtained.

[ extensible spunbonded nonwoven Fabric ]

The extensible spunbond nonwoven fabric according to the present disclosure preferably has a maximum load elongation of 45% or more, more preferably 70% or more, further preferably 100% or more, and particularly preferably 150% or more in at least one direction. The extensible spunbond nonwoven is preferably a nonwoven having little elastic recovery. The elongation at maximum load of the extensible spunbond nonwoven fabric [% ] was determined by the same method as the elongation at maximum load of the nonwoven fabric laminate. The extensible spunbond nonwoven fabric to which the present disclosure relates may have an elongation at maximum load of 600% or less in at least one direction, and may have an elongation at maximum load of 500% or less.

The basis weight of the extensible spunbonded nonwoven fabric is preferably 120g/m²Hereinafter, more preferably 80g/m²Hereinafter, it is more preferably 50g/m²Hereinafter, it is particularly preferably 40g/m²～5g/m²More preferably 30g/m²～5g/m²Extremely preferably 25g/m²～8g/m²。

The fiber diameter of the fibers constituting the extensible spunbond nonwoven fabric is preferably 50 μm or less, more preferably 40 μm or less, and still more preferably 30 μm or less. The fibers constituting the extensible spunbond nonwoven fabric may have a fiber diameter of 1.0 μm or more.

The extensible spunbond nonwoven fabric may be any of a concentric core-sheath type composite fiber having a core portion and a sheath portion, an island-in-sea type composite fiber having a sea portion and an island portion, a side-by-side type composite fiber, and a crimped composite fiber. The extensible spunbond nonwoven is preferably a concentric core-sheath type composite fiber or an islands-in-the-sea type composite fiber.

The extensible spunbonded nonwoven fabric comprising the concentric core-sheath composite fiber is preferably an olefin polymer having a low MFR in the range of 1g/10 min to 1000g/10 min in the core part, an olefin polymer having a high MFR in the range of 1g/10 min to 1000g/10 min in the sheath part, and the difference between the MFR of the olefin polymer having a low MFR and the MFR of the olefin polymer having a high MFR is 1g/10 min or more. The difference in MFR is more preferably 15g/10 min or more, still more preferably 30g/10 min or more, and particularly preferably 40g/10 min or more. The difference in MFR may be 100g/10 min or less, or may be 70g/10 min or less.

The extensible spunbond nonwoven fabric including the sea-island type composite fiber may be a sea-island type composite fiber in which the sea portion is made of a propylene polymer (preferably, a homopolymer of propylene) and the island portion is made of an ethylene polymer (preferably, high-density polyethylene).

Examples of the extensible spunbond nonwoven fabric include a nonwoven fabric using 1 or 2 or more olefin polymer compositions described later.

(olefin Polymer composition)

The extensible spunbond nonwoven preferably comprises an olefin-based polymer, preferably is formed from an olefin-based polymer composition comprising an olefin-based polymer. The olefin polymer may be a polyolefin elastomer.

The olefin polymer composition may contain, as optional components, various known additives such as an antioxidant, a heat stabilizer, a weather stabilizer, an antistatic agent, a slip agent, an antifogging agent, a lubricant, a dye, a pigment, a natural oil, a synthetic oil, a wax, and a hydrophilic agent, within a range not to impair the object of the present disclosure.

The olefin-based polymer is preferably a polymer having crystallinity. Examples of the crystalline component in the polymer having crystallinity include poly-1-butene and poly-4-methyl-1-pentene. The olefin polymer may be used alone in 1 kind, or 2 or more kinds may be used in combination.

Examples of the olefin-based polymer include homopolymers or copolymers of α -olefins such as ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene. Examples of the α -olefin copolymer include ethylene polymers and propylene polymers.

Examples of the ethylene polymer include ethylene homopolymers such as high-pressure low-density polyethylene, linear low-density polyethylene (so-called LLDPE), and high-density polyethylene (so-called HDPE), and random copolymers or block copolymers of ethylene and α -olefins.

The density of the ethylene polymer is not particularly limited, and is preferably 0.94g/cm³～0.97g/cm³More preferably 0.95g/cm³～0.97g/cm³More preferably 0.96g/cm³～0.97g/cm³。

The MFR of the ethylene polymer is not particularly limited as long as it has spinnability, and is, for example, preferably 0.1g/10 min to 100g/10 min, more preferably 0.5g/10 min to 50g/10 min, and still more preferably 1g/10 min to 30g/10 min, from the viewpoint of elongation.

The propylene polymer generally refers to a crystalline resin manufactured and sold under the name of polypropylene. The propylene polymer is preferably a homopolymer of propylene or a copolymer containing propylene as a main component.

Examples of the copolymer mainly containing propylene include copolymers containing an α -olefin having 2 or more carbon atoms (preferably an α -olefin having 2 to 8 carbon atoms) such as ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 4-methyl-1-pentene as a copolymerization component (excluding an olefin having 3 carbon atoms, that is, propylene). The copolymer containing propylene as a main component may be any of a random copolymer, a block copolymer, and the like.

The melting point (Tm) of the propylene homopolymer is preferably 155 ℃ or higher, more preferably 157 to 165 ℃.

The melting point (Tm) of the copolymer containing propylene as the main component is preferably 130 ℃ or more and less than 155 ℃, more preferably 130 to 150 ℃.

The MFR of the propylene-based polymer is not particularly limited as long as it can be melt-spun. The MFR of the propylene-based polymer is, for example, preferably 1g/10 min to 1000g/10 min, more preferably 5g/10 min to 500g/10 min, and still more preferably 10g/10 min to 100g/10 min.

The extensible spunbond nonwoven fabric may contain a polymer other than the olefin polymer (hereinafter, also referred to as "other polymer") or may not contain the other polymer. Examples of the other polymer include thermoplastic resins other than thermoplastic elastomers and olefin polymers.

Specific examples of the thermoplastic elastomer include styrene-based elastomers, polyester-based elastomers, polyamide-based elastomers, thermoplastic polyurethane-based elastomers, vinyl chloride-based elastomers, and fluorine-based elastomers.

Specific examples of the thermoplastic resin other than the olefin-based polymer include polyesters (e.g., polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate), polyamides (e.g., nylon-6, nylon-66, and poly (m-xylylene adipamide)), polyvinyl chloride, polyimide, ethylene-vinyl acetate copolymers, ethylene-vinyl acetate-vinyl alcohol copolymers, ethylene- (meth) acrylic acid copolymers, ethylene-acrylic ester-carbon monoxide copolymers, polyacrylonitrile, polycarbonate, and polystyrene.

The content of the olefin polymer in the extensible spunbond nonwoven fabric is preferably more than 90 mass% and 100 mass% or less, and more preferably 95 mass% to 100 mass% with respect to the total of the olefin polymer and the other polymer (the thermoplastic elastomer and the thermoplastic resin other than the olefin polymer).

The extensible spunbond nonwoven fabric contains no other polymer, or the content of the other polymer (the thermoplastic elastomer and the thermoplastic resin other than the olefin polymer) in the extensible spunbond nonwoven fabric is preferably more than 0% and less than 10% by mass, more preferably more than 0% and 5% by mass or less, relative to the total of the olefin polymer and the other polymer.

When the olefin-based polymer composition contains a propylene-based polymer and an ethylene-based polymer, the content of the propylene-based polymer is preferably 80 to 99% by mass, and more preferably 84 to 96% by mass, based on the total amount of the olefin-based polymer composition. On the other hand, the content of the ethylene polymer is preferably 20 to 1% by mass, and more preferably 16 to 4% by mass, based on the total amount of the olefin polymer composition (wherein 100% by mass is the propylene polymer + ethylene polymer).

(specific example of extensible spunbonded nonwoven Fabric)

The extensible spunbond nonwoven fabric preferably includes an extensible spunbond nonwoven fabric satisfying the following requirements (1) to (3).

(1) A spun-bonded nonwoven fabric using a core-sheath type conjugate fiber, a side-by-side type conjugate fiber or a crimped conjugate fiber, which contains two or more olefin polymers having a difference in the induction time of crystallization in flow-induced phase separation of 100 seconds or more.

The two or more olefin polymers may be, for example, a high-melting propylene polymer or a low-melting propylene polymer.

(2) A spunbonded nonwoven fabric comprising an island-in-sea type composite fiber, a core-sheath type composite fiber, a side-by-side type composite fiber or a crimped composite fiber, which comprises an olefin polymer composition comprising a propylene polymer and an ethylene polymer. The olefin polymer composition is particularly preferably an olefin polymer composition described below.

(2-1) an olefin polymer composition comprising 80 to 99% by mass of a propylene homopolymer and 20 to 1% by mass of a high-density polyethylene.

(2-2) an olefin-based polymer composition comprising a high-melting propylene-based polymer having the same or different MFR and a melting point in the range of 157 ℃ to 165 ℃.

The propylene polymer may be, for example, a propylene polymer obtained by copolymerizing a propylene homopolymer, a random copolymer of propylene having a low melting point and an α -olefin, the melting point of which is in the range of 130 to 150 ℃.

(3) A spun-bonded nonwoven fabric using a concentric core-sheath composite fiber, wherein the core part is a low-MFR propylene polymer having an MFR in the range of 1g/10 min to 200g/10 min, the sheath part is a high-MFR propylene polymer having an MFR in the range of 16g/10 min to 215g/10 min, and the difference between the MFR of the core part and the MFR of the sheath part is 15g/10 min or more.

Examples of the extensible spunbond nonwoven fabric satisfying the requirements (1) to (3) include extensible spunbond nonwoven fabrics (a) and (B) described below.

(A) A spun-bonded nonwoven fabric comprising a core-sheath type composite fiber, a side-by-side composite fiber or a crimped composite fiber, wherein the core part is a low-MFR and high-melting-point propylene polymer (preferably a propylene homopolymer) having an MFR of 10g/10 min to 200g/10 min and a melting point of 157 ℃ to 165 ℃, the sheath part is a high-MFR and low-melting-point propylene-alpha-olefin random copolymer having an MFR of 10g/10 min to 200g/10 min and a melting point of 130 ℃ to 150 ℃, and the difference between the MFR of the core part and the MFR of the sheath part is 1g/10 min or more.

(B) A spun-bonded nonwoven fabric comprising a concentric core-sheath composite fiber, wherein the core part is a low-MFR propylene polymer (preferably a propylene homopolymer) having an MFR in the range of 1g/10 min to 200g/10 min, the sheath part is a high-MFR propylene polymer (preferably a propylene homopolymer) having an MFR in the range of 31g/10 min to 230g/10 min, and the difference between the MFR in the core part and the MFR in the sheath part is 30g/10 min or more.

In the above (B), the core part may be a low MFR propylene polymer having an MFR in the range of 10g/10 min to 50g/10 min, and the sheath part may be a high MFR propylene polymer having an MFR in the range of 50g/10 min to 100g/10 min. The difference between the MFR of the core portion and the MFR of the sheath portion may be 30g/10 min to 100g/10 min, or 40g/10 min to 80g/10 min or less.

[ other layers ]

Other layers may be laminated on the nonwoven fabric laminate of the present disclosure depending on various uses. The other layers to be laminated on the nonwoven fabric laminate of the present disclosure are not particularly limited, and various layers may be laminated according to the application.

Specific examples of the other layer include a nonwoven fabric other than a knitted fabric, a woven fabric, an elastic nonwoven fabric and an extensible spunbond nonwoven fabric, a film, and the like. The method for further laminating (bonding) another layer on the nonwoven fabric laminate of the present disclosure is not particularly limited, and various methods such as hot embossing, a hot-melt method such as ultrasonic fusion, a mechanical knitting method such as needle punching and water jet, a method using an adhesive such as a hot-melt adhesive or a urethane adhesive, and extrusion lamination can be used.

When the nonwoven fabric laminate of the present disclosure includes a nonwoven fabric other than an elastic nonwoven fabric and an extensible nonwoven fabric, there may be mentioned various known nonwoven fabrics such as a spunbond nonwoven fabric, a meltblown nonwoven fabric, a wet nonwoven fabric, a dry pulp nonwoven fabric, a flash-spun nonwoven fabric, and a spread nonwoven fabric. These nonwoven fabrics may be elastic nonwoven fabrics or non-elastic nonwoven fabrics. Here, the non-stretchable nonwoven fabric means a nonwoven fabric which does not generate a recovery stress after being stretched in MD (flow direction of the nonwoven fabric, longitudinal direction) or CD (direction perpendicular to the flow direction of the nonwoven fabric, transverse direction).

As a film in the case where the nonwoven fabric laminate of the present disclosure has a film, an air-permeable (moisture-permeable) film is preferable from the viewpoint of maintaining air permeability and hydrophilicity, which are characteristics of the nonwoven fabric laminate of the present disclosure. Examples of the air-permeable film include various known air-permeable films such as a film made of a thermoplastic elastomer such as a polyurethane elastomer, a polyester elastomer, or a polyamide elastomer having moisture permeability, and a porous film formed by stretching and making porous a film made of a thermoplastic resin containing inorganic fine particles or organic fine particles. The thermoplastic resin used for the porous film is preferably a polyolefin such as high-pressure low-density polyethylene, linear low-density polyethylene (so-called LLDPE), high-density polyethylene, polypropylene random copolymer, or a combination thereof. However, when it is not necessary to maintain the air permeability and hydrophilicity of the nonwoven fabric laminate, a film of a thermoplastic resin such as polyethylene, polypropylene, or a combination thereof may be used.

[ method for producing nonwoven Fabric laminate ]

The nonwoven fabric laminate of the present disclosure can be produced by a known nonwoven fabric production method using an elastic nonwoven fabric containing an α -olefin copolymer, an extensible spunbond nonwoven fabric, and an additive used as needed.

As an example of the method for producing a nonwoven fabric laminate, a method using a nonwoven fabric production apparatus provided with at least two spinning devices will be described below. The following examples are examples of a method for producing a nonwoven fabric laminate using an olefin polymer as an extensible spunbond nonwoven fabric and an α -olefin copolymer as an elastic nonwoven fabric.

In the nonwoven fabric laminate of the present disclosure, from the viewpoint of production, it is preferable to arrange an extensible spunbond nonwoven fabric on a surface that is in contact with a rotary device attached to a nonwoven fabric production apparatus.

First, an olefin-based polymer and, if necessary, two or more kinds of olefin-based polymers are melted by an extruder and, if necessary, two or more extruders provided in a first row of a spinning device, introduced into a die (die head) provided with a plurality of spinning holes (nozzles) and, if necessary, a spinning hole having a core-sheath structure, and discharged. Then, the long fibers including the melt-spun olefin-based polymer are introduced into a cooling chamber, cooled by cooling air, and then drawn (pulled) by drawing air, thereby depositing the extensible spunbond nonwoven fabric on the moving collection surface.

On the other hand, the resin composition containing the α -olefin copolymer of the present disclosure is melted by an extruder provided in the second row of spinning devices, introduced into a spinning hole having a die (die head) provided with a plurality of spinning holes (nozzles), and discharged. Then, the long fibers containing the melt-spun resin composition are introduced into a cooling chamber, cooled by cooling air, and then stretched (drawn) by stretching air to be deposited on the extensible spunbond nonwoven fabric, thereby forming an elastic nonwoven fabric.

If desired, a third row of spinning apparatus may be used to deposit the extensible spunbond nonwoven onto the elastic nonwoven.

The melting temperature of each polymer in the elastic nonwoven fabric and the extensible spunbond nonwoven fabric is not particularly limited as long as it is not lower than the softening temperature or the melting temperature of each polymer and lower than the thermal decomposition temperature. The temperature of the die depends on the kind of the polymer used, and for example, in the case of using a copolymer of ethylene and propylene as the α -olefin copolymer, the temperature of the die is preferably 180 to 240 ℃, more preferably 190 to 230 ℃, and further preferably 200 to 225 ℃.

The temperature of the cooling air is not particularly limited as long as it is a temperature at which the polymer is solidified, and is preferably 5 to 50 ℃, more preferably 10 to 40 ℃, and still more preferably 15 to 30 ℃. The air speed of the drawing air is preferably 100 m/min to 10,000 m/min, more preferably 500 m/min to 10,000 m/min.

The nonwoven fabric laminate of the present disclosure preferably has a structure in which at least a portion of the elastic nonwoven fabric is thermally fused with at least a portion of the extensible spunbond nonwoven fabric. At this time, a nip roller may be used before at least a portion of the elastic nonwoven fabric is thermally fused with at least a portion of the extensible spunbond nonwoven fabric.

The method of thermal fusion is not particularly limited, and can be selected from various known methods. For example, a method using means such as ultrasonic waves, a hot embossing method using an embossing roller, a method using hot air molding, and the like can be given as the preliminary bonding. Among them, hot embossing is preferable from the viewpoint that the long fibers are efficiently drawn in drawing, and the temperature range thereof is preferably 40 to 115 ℃.

When a part of the laminate is thermally fused by hot embossing, the embossed area ratio is preferably 5% to 30%, more preferably 5% to 20%. The non-embossed unit area is preferably 0.5mm²Above, more preferably 4mm²～40mm². The non-embossed unit area means the minimum area surrounded by the embossed portion in four directionsIn the non-embossed portion of the cell, the maximum area of a quadrangle inscribed with the emboss is provided. Examples of the shape of the imprint include a circle, an ellipse, an oval, a square, a rhombus, a rectangle, a quadrangle, a continuous shape based on these shapes, and the like.

< stretchable nonwoven fabric laminate >

The stretchable nonwoven fabric laminate of the present disclosure is a stretchable nonwoven fabric laminate obtained by stretching the aforementioned nonwoven fabric laminate.

The stretchable nonwoven fabric laminate of the present disclosure is a stretched product of a nonwoven fabric laminate obtained by stretching the nonwoven fabric laminate. The method of the drawing is not particularly limited, and conventionally known methods can be applied. The stretching method may be a partial stretching method or a whole stretching method. Further, the stretching may be performed uniaxially or biaxially. As a method of stretching in the Machine Direction (MD), for example, a method of passing the partially fused mixed fiber through 2 or more nip rollers is cited. At this time, the rotation speed of the nip roller is accelerated in the order of the machine flow direction, whereby the partially fused nonwoven fabric laminate can be stretched. Further, the gear drawing device shown in fig. 1 can be used to perform gear drawing.

The lower limit of the stretch ratio is preferably 50% or more, more preferably 100% or more, and still more preferably 200% or more. On the other hand, the upper limit of the stretch ratio is preferably 1000% or less, and more preferably 500% or less.

In the case of uniaxial stretching, it is preferable that either the stretching ratio in the Machine Direction (MD) or the direction (CD) perpendicular thereto satisfies the above-mentioned stretching ratio. In the case of biaxial stretching, at least one of the Machine Direction (MD) and the direction (CD) perpendicular thereto preferably satisfies the above-mentioned stretching magnification.

By performing the stretching process at the above-described stretching ratio, both the (long) fibers forming the elastic nonwoven fabric and the extensible spunbond nonwoven fabric are stretched. The long fibers forming the extensible spunbond nonwoven layer are plastically deformed and extended (i.e., lengthened) in accordance with the above-described draw ratio.

When the nonwoven fabric laminate is stretched and then the stress is released, the (long) fibers forming the elastic nonwoven fabric are elastically restored, the long fibers forming the extensible spunbond nonwoven fabric are not elastically restored and buckled, and the nonwoven fabric laminate exhibits a bulky feeling. Further, the long fibers forming the extensible spunbond nonwoven tend to be fine. Therefore, it is considered that the flexibility and the touch are improved and the function of stopping the elongation can be provided.

< fiber product >

The fibrous article of the present disclosure comprises the nonwoven fabric laminate or stretchable nonwoven fabric laminate of the present disclosure. The fiber product is not particularly limited, and examples thereof include absorbent articles such as disposable diapers and sanitary products, sanitary articles such as sanitary masks, medical articles such as bandages, clothing materials, and packaging materials. The fibrous article of the present disclosure preferably comprises the nonwoven fabric laminate or the stretchable nonwoven fabric laminate of the present disclosure as a stretchable member.

Examples

The present invention will be described in further detail below with reference to examples, but the present invention is not limited to the following examples. The materials, amounts used, ratios, processing steps, and the like shown in the following examples can be appropriately modified without departing from the spirit of the present disclosure. In addition, "part" means "part by mass" unless otherwise specified.

Preparation of the material

As a raw material of the elastic nonwoven fabric, the following materials were prepared.

Alpha-olefin copolymer 1A (propylene/ethylene copolymer)

Manufactured by Exxon Mobil corporation, product name "Vistamaxx^TM6202 ", MFR (230 ℃, load 2.16 kg): 20g/10 min, ethylene content: 15 mass%, tensile elastic modulus: 9.8 MPa.

Alpha-olefin copolymer 1B (propylene/ethylene copolymer)

Manufactured by Exxon Mobil corporation, product name "Vistamaxx^TM7050FL ", MFR (230 ℃, Carrier)Load 2.16 kg): 48g/10 min, ethylene content: 13 mass%, tensile elastic modulus: 14.4 MPa.

Synthesis of alpha-olefin homopolymer 1C (Low crystalline Polypropylene)

An internal volume of 0.2m with a stirrer³In the stainless steel reactor (2), a catalyst component obtained by bringing dimethylanilinium tetrakis (pentafluorophenyl) borate into contact with (1,2 '-dimethylsilylene) (2, 1' -dimethylsilylene) -bis (3-trimethylsilylmethyl indenyl) zirconium dichloride and triisobutylaluminum into contact with propylene in advance was continuously supplied at a zirconium unit of 6. mu. mol/h with n-heptane at 20L/h and triisobutylaluminum at 15 mmol/h. Propylene and hydrogen were continuously supplied at a polymerization temperature of 70 ℃ so that the hydrogen concentration in the gas phase portion was 8 mol% and the total pressure in the reactor was maintained at 0.7 MPa.G. To the obtained polymerization solution, SUMILIZER GP (manufactured by sumitomo chemical corporation) was added so as to reach 1000ppm, and the solvent was removed, thereby obtaining a propylene polymer.

The weight average molecular weight (Mw) of the obtained propylene polymer was 1.2X 10⁴Mw/Mn is 2. Furthermore, [ mmmm ] determined by NMR measurement]Is 46 mol%, [ rrrr%]/(1-[mmmm]) Is 0.038, [ rmrm]Is 2.7 mol%, [ mm ]]×[rr]/[mr]²1.5 and a tensile modulus of elasticity of 32.9 MPa.

Further, [ mmmm ] is a meso pentad fraction, [ rrrr ] is a racemic pentad fraction, [ rmrm ] is a racemic meso pentad fraction, [ mm ], [ rr ] and [ mr ] are triad fractions, respectively. These values can be obtained by, for example, the method described in international publication No. 2016/143834.

[ example 1]

MFR (measured according to ASTM D1238 at a temperature of 230 ℃ C. and a load of 2.16kg) of 8.5g/10 min and a density of 0.91g/cm³A propylene homopolymer having a melting point of 160 ℃ (hereinafter referred to as "Polymer 2A"; and referred to as "PP" in tables 1 and 2) was usedIndependently of the Melt Flow Rate (MFR) (according to ASTM D1238, at a temperature of 230 ℃ C., load 2).16kg) 60g/10 min, density 0.91g/cm³A propylene homopolymer having a melting point of 160 ℃ (hereinafter referred to as "Polymer 2B"; and referred to as "PP" in tables 1 and 2) was usedAfter melting by the extruder of (1), an extensible spunbonded nonwoven fabric comprising a concentric core-sheath composite fiber having a mass ratio of core portion to sheath portion of 10/90 was deposited as the 1 st layer on the collecting surface by carrying out composite melt spinning by a spunbond method using a spunbonded nonwoven fabric forming machine (die, number of holes: 2887 holes) having a spinneret (length in the direction perpendicular to the machine flow direction on the collecting surface: 800mm) capable of forming a concentric core-sheath composite fiber having a core portion of "polymer 2A" and a sheath portion of "polymer 2B" and under conditions of a resin temperature and a die temperature of 250 ℃, a cooling air temperature of 20 ℃ and a stretching air speed of 3750 m/min.

Then, on the deposition surface, the above-mentioned alpha-olefin copolymer 1A was applied with a screw diameterAfter melting by the single-screw extruder of (1), an elastic nonwoven fabric (elastic spunbond nonwoven fabric) was deposited as the 2 nd layer by melt-spinning by a spunbond method using a spunbond nonwoven fabric forming machine (length in the direction perpendicular to the machine flow direction on the collecting surface: 800mm) having a spinneret (die, number of holes 808) under conditions of a resin temperature and a die temperature of 215 ℃, a cooling air temperature of 20 ℃, and a stretching air speed of 3750 m/min. In this step, the α -olefin copolymer 1A has very good spinnability.

Next, as the 3 rd layer, the same core-sheath composite fiber as the 1 st layer was stacked by the same method to prepare a 3-layer stack. The deposit was subjected to heat and pressure treatment with an embossing roll (embossing area ratio 18%, embossing temperature 70 ℃) to give a total basis weight of 30.0g/m²The basis weight of the 1 st and 3 rd layers was 10.0g/m²The basis weight of the elastic nonwoven fabric layer as the 2 nd layer was 10.0g/m²Nonwoven fabric laminate (elastic nonwoven fabric)The mass fraction of the fabric layer relative to the whole was 33.3%).

The nonwoven fabric laminate obtained as described above hardly adheres to the surface of the metal roll in the embossing step, and has good moldability. Further, when the nonwoven fabric laminate is wound into a roll, roll blocking (a phenomenon in which nonwoven fabrics overlapped with each other adhere to each other to consolidate the roll) does not occur, and the nonwoven fabric laminate can be easily pulled out.

[ example 2]

A nonwoven fabric laminate was obtained in the same manner as in example 1, except that the raw material of the elastic nonwoven fabric was changed from the α -olefin copolymer 1A to the α -olefin copolymer 1B.

Comparative example 1

A nonwoven fabric laminate was obtained in the same manner as in example 1, except that the raw material of the elastic nonwoven fabric was changed from the α -olefin copolymer 1A to the α -olefin homopolymer 1C.

[ example 3]

The basis weight of the extensible spunbonded nonwoven in the 1 st and 3 rd layers and the basis weight of the elastic nonwoven in the 2 nd layer are from 10.0g/m²Changed to 16.7g/m²Except for this, a nonwoven fabric laminate was obtained in the same manner as in example 1.

[ example 4]

The basis weight of the extensible spunbonded nonwoven fabric in the 1 st and 3 rd layers is from 10.0g/m²Changed to 15.6g/m²The basis weight of the elastic nonwoven fabric in the 2 nd layer was adjusted to 10.0g/m²Changed to 18.8g/m²Except for this, a nonwoven fabric laminate was obtained in the same manner as in example 1.

[ example 5]

The basis weight of the extensible spunbonded nonwoven in the 1 st and 3 rd layers and the basis weight of the elastic nonwoven in the 2 nd layer are from 10.0g/m²Changed to 20.0g/m²Except for this, a nonwoven fabric laminate was obtained in the same manner as in example 1.

[ example 6]

The basis weight of the extensible spunbonded nonwoven in the 1 st and 3 rd layers and the basis weight of the elastic nonwoven in the 2 nd layer are from 10.0g/m²Changed to 20.0g/m²Except for this, a nonwoven fabric laminate was obtained in the same manner as in example 2.

Comparative example 2

The basis weight of the extensible spunbonded nonwoven in the 1 st and 3 rd layers and the basis weight of the elastic nonwoven in the 2 nd layer are from 10.0g/m²Changed to 20.0g/m²Except for this, a nonwoven fabric laminate was obtained in the same manner as in comparative example 1.

Comparative example 3

The basis weight of the elastic nonwoven fabric in the 2 nd layer is controlled to be 20.0g/m²To 25.0g/m²Except for this, a nonwoven fabric laminate was obtained in the same manner as in comparative example 2.

Evaluation-

(spinnability)

In the production of each nonwoven fabric, the number of yarn breaks per 5 minutes (unit: times/5 minutes) was calculated by visually observing the state of spinning near the nozzle surface of the spunbond nonwoven fabric production apparatus. If the number of yarn breaks was 0 times/5 minutes, the nonwoven fabric was evaluated as "A", and if the yarn breaks and the nonwoven fabric was not collected, the nonwoven fabric was evaluated as "B" (tables 1 and 2).

Evaluation of the expansion and contraction characteristics (stress at 50% elongation, stress at 50% recovery) -

From the nonwoven fabric laminate of each example, 5 test pieces of 50mm (CD) x 200Mm (MD) were collected using a universal tensile tester (model IM-201 manufactured by Intesco corporation). Then, for each of the collected test pieces, the test piece was 100% elongated under the conditions of a sample width of 50mm, a distance between chucks of 100mm, and a drawing speed of 100 mm/min, and immediately returned to the original length at the same speed. This operation was further performed for 1 cycle, and the stress at which the elongation-time stretching ratio of the 2 nd cycle reached 50% was set as the stress at 50% elongation, and the stress at which the recovery-time stretching ratio of the 2 nd cycle reached 50% was set as the stress at 50% recovery. Next, as a measure of the stretch property, a value of [ stress at 50% recovery ÷ stress at 50% elongation ] was measured, and the arithmetic mean value of the 5-piece test pieces was evaluated as the stretch property. The larger the value of [ stress at 50% recovery ÷ stress at 50% elongation ], the more excellent the stretch properties (tables 1 and 2).

In addition, the results of the measurement by the above-described measurement method are shown in tables 1 and 2 with respect to the storage elastic modulus at each temperature, the ratio of the storage elastic modulus, the maximum load elongation, and the basis weight of each nonwoven fabric in each example.

[ Table 1]

[ Table 2]

As shown in tables 1 and 2, the nonwoven fabric laminates of examples were found to have excellent stretch properties and stress retention as compared with the nonwoven fabric laminates of comparative examples.

The disclosure of japanese patent application No. 2018-201247, filed on 25/10/2018, is incorporated by reference in its entirety into this specification.

All documents, patent applications, and technical standards described in the present specification are incorporated by reference into the present specification to the same extent as if each document, patent application, or technical standard was specifically and individually described.