JP7318237B2 - Nonwoven fabric, laminate, covering sheet, and method for producing nonwoven fabric - Google Patents

Description

The present disclosure relates to nonwoven fabrics, laminates, coated sheets, and methods of making nonwoven fabrics.

BACKGROUND ART In recent years, nonwoven fabrics have been widely used for various purposes because of their excellent air permeability and flexibility. Therefore, nonwoven fabrics are required to have various properties according to their uses, and improvements in these properties are required.

For example, nonwoven fabrics used for members that come into direct contact with the skin (such as top sheets for absorbent articles) are required to have excellent hydrophilicity. As one method for imparting hydrophilicity to nonwoven fabrics, a method of producing nonwoven fabrics using water-permeable fibers to which a specific water permeability imparting agent is attached to hydrophobic synthetic fibers for nonwoven fabric production has been proposed. (See Patent Document 1, for example).

JP 2012-102424 A

By the way, a kneading method and a coating method are known as methods for imparting hydrophilicity to a nonwoven fabric. In the kneading method, an agent for imparting hydrophilicity (hereinafter, the agent for imparting hydrophilicity is referred to as a hydrophilic agent) is kneaded into a nonwoven fabric to form a nonwoven fabric with fibers of a thermoplastic polymer. It is a method of imparting hydrophilicity to. The coating method is a method of imparting hydrophilicity to the nonwoven fabric by adhering a hydrophilizing agent to the fiber surface.

When a nonwoven fabric to which a hydrophilizing agent is applied is applied, for example, to the topsheet of a diaper, the hydrophilizing agent may migrate to members (gathers, etc.) that come into contact with the topsheet of the diaper. For example, if the gathers become hydrophilic due to migration of the hydrophilizing agent to the gathers, liquid leakage may occur in the diaper.

In addition, when a nonwoven fabric to which a hydrophilizing agent is added is applied to uses involving post-processing such as diapers (for example, stretching and perforating), the hydrophilizing agent may migrate to the processing machine. If the hydrophilizing agent continues to migrate to the processing machine over a long period of time, corrosion due to migration of the hydrophilizing agent may occur.

Thus, the nonwoven fabric imparted with hydrophilicity is required to have excellent hydrophilicity, and there is still room for improvement from the viewpoint of suppressing migration of the hydrophilizing agent to members that come into contact with the nonwoven fabric.

An object of the present disclosure is to provide a nonwoven fabric that is excellent in hydrophilicity and that suppresses migration of a hydrophilizing agent when in contact with other members. An object of the present disclosure is to provide a laminate including a nonwoven fabric that is excellent in hydrophilicity and that suppresses migration of a hydrophilizing agent when in contact with other members. An object of the present disclosure is to provide a method for producing a nonwoven fabric that is excellent in hydrophilicity and that suppresses migration of a hydrophilizing agent when in contact with other members.

The present disclosure relates to the following aspects.

<1>
fibers of a thermoplastic polymer;
a penetrant comprising at least one of a sulfonate and a sulfate;
a wetting agent;
The ratio of the surface water vapor adsorption area in the water vapor adsorption test obtained by the BET formula of the water vapor adsorption isotherm to the surface nitrogen adsorption area in the nitrogen adsorption test obtained from the BET formula of the nitrogen adsorption isotherm (surface water vapor adsorption area / surface A nonwoven fabric having a nitrogen adsorption area) of 2.0 to 5.8.
<2>
The nonwoven fabric according to <1>, having a surface water vapor adsorption area of 0.4 m ^{2 /} g to 1.2 m ² /g in a water vapor adsorption test obtained by the BET formula of a water vapor adsorption isotherm.
<3>
The nonwoven fabric according to <1> or <2>, wherein the sulfonate is an alkylsulfosuccinate.
<4>
The nonwoven fabric according to any one of <1> to <3>, wherein the ratio of the penetrating agent to the wetting agent (penetrating agent/wetting agent) is 1/99 to 60/40 by mass.
<5>
The fiber has a propylene polymer composition containing 100 parts by mass of a propylene polymer (A) having a melting point of 130° C. or higher and 1 to 10 parts by mass of an ethylene polymer (B) <1> The nonwoven fabric according to any one of <4>.
<6>
The nonwoven fabric according to <5>, wherein the ethylene polymer (B) has a density of 0.930 g/cm ³ to 0.980 g/cm ³ .
<7>
The nonwoven fabric according to <5> or <6>, wherein the propylene polymer composition further contains an ethylene polymer wax (C) having a weight average molecular weight (Mw) of 400 to 30,000.
<8>
The nonwoven fabric according to <7>, wherein the ethylene polymer wax (C) has a density of 0.890 g/cm ³ to 0.980 g/cm ³ .
<9>
The propylene-based polymer composition according to any one of <5> to <8>, wherein the propylene-based polymer (D) shown in (III) below is contained in an amount of more than 0 parts by mass and 25 parts by mass or less. non-woven fabric.
(III) Propylene homopolymer having a melting point of less than 120°C satisfying the following (a) to (f) (a) [mmmm] = 20 mol% to 60 mol%
(b) [rrrr]/(1−[mmmm])≦0.1
(c) [rmrm] > 2.5 mol%
(d) [mm]×[rr]/[mr]2≦2.0
(e) Weight average molecular weight (Mw) = 10,000 to 200,000
(f) molecular weight distribution (Mw/Mn) <4
In (a) to (d), [mmmm] is the mesopentad fraction, [rrrr] is the racemic pentad fraction, [rmrm] is the racemic meso-racemic mesopentad fraction, [m
m], [rr] and [mr] are triad fractions respectively.
<10>
The nonwoven fabric according to any one of <1> to <9>, having an average fiber diameter of 5 μm to 25 μm.
<11>
A total of 0.02 g of the penetrating agent and the wetting agent is added to 20 ml of a 1/1 mixture of hexane/water, and the penetrating agent and the wetting agent are The nonwoven fabric according to any one of <1> to <10>, wherein the added mixed solution is stirred to separate the oil phase and the aqueous phase after 1 minute.
<12>
Any one of <1> to <11>, wherein the wetting agent contains at least one selected from the group consisting of polyhydric alcohol fatty acid esters, polyoxyalkylene fatty acid esters, and alkylene oxide adducts of polyhydric alcohol fatty acid esters. The nonwoven fabric described in 1.
<13>
The nonwoven fabric according to any one of <1> to <12>, which is a spunbond nonwoven fabric.
<14>
A covering sheet comprising the nonwoven fabric according to any one of <1> to <13>.
<15>
A laminate comprising the nonwoven fabric according to any one of <1> to <13>.
<16>
A covering sheet comprising the laminate according to <15>.
<17>
providing a nonwoven comprising fibers of a thermoplastic polymer;
a step of adhering a penetrant containing at least one of a sulfonate and a sulfate salt and a wetting agent to the nonwoven fabric;
has
Ratio of the surface water vapor adsorption area in the water vapor adsorption test obtained by the BET formula of the water vapor adsorption isotherm to the surface nitrogen adsorption area in the nitrogen adsorption test obtained from the BET formula of the nitrogen adsorption isotherm (surface water vapor adsorption area/surface nitrogen adsorption area) is 2.0 to 5.8, a method for producing a nonwoven fabric.

ADVANTAGE OF THE INVENTION According to this disclosure, the nonwoven fabric which is excellent in hydrophilicity and suppressed migration of the hydrophilizing agent when in contact with other members is provided. According to the present disclosure, there is provided a laminate comprising a nonwoven fabric that is excellent in hydrophilicity and that suppresses migration of a hydrophilizing agent when in contact with other members. According to the present disclosure, there is provided a method for producing a nonwoven fabric that is excellent in hydrophilicity and that suppresses migration of a hydrophilizing agent when in contact with other members.

The present disclosure will now be described in detail with respect to an example of a preferred embodiment. These descriptions and examples are illustrative of embodiments and do not limit the scope of embodiments.

In the present disclosure, a numerical range indicated using "to" indicates a range including the numerical values before and after "to" as the minimum and maximum values, respectively.
In the present disclosure, the term "process" includes not only an independent process, but also a process that cannot be clearly distinguished from other processes as long as the purpose of the process is achieved.
In the present disclosure, the content of each component in the composition is the total amount of the multiple substances present in the composition, unless otherwise specified, when multiple substances corresponding to each component are present in the composition. means
In the present disclosure, MD (Machine Direction) refers to the traveling direction of a nonwoven web in a nonwoven fabric manufacturing apparatus. The CD (Cross Direction) direction refers to a direction perpendicular to the MD direction and parallel to the main surface (surface perpendicular to the thickness direction of the nonwoven fabric).
In the present disclosure, "mainly containing" means that the substance of interest is contained in the largest amount with respect to the whole. For example, it indicates that the content ratio of the target substance is 50% by mass or more as a percentage of the whole.

<Nonwoven fabric>
An example of a preferred embodiment of the nonwoven fabric of the present disclosure will be described.
The nonwoven fabric of the present disclosure contains fibers of a thermoplastic polymer, a penetrating agent comprising at least one of a sulfonate and a sulfate, and a wetting agent.
Then, the nonwoven fabric of the present disclosure is the ratio of the surface water vapor adsorption area in the water vapor adsorption test obtained by the BET formula of the water vapor adsorption isotherm to the surface nitrogen adsorption area in the nitrogen adsorption test obtained from the BET formula of the nitrogen adsorption isotherm (surface water vapor The adsorption area/surface nitrogen adsorption area) is 2.0 to 5.8.

In the present disclosure, penetrants and wetting agents function as agents for imparting hydrophilicity. In the following description, penetrants and wetting agents are also collectively referred to as hydrophilizing agents in the present disclosure.

The nonwoven fabric of the present disclosure contains fibers of a thermoplastic polymer and the hydrophilizing agent described above, so that the nonwoven fabric has excellent hydrophilicity and suppresses migration of the hydrophilizing agent when it contacts other members. The reason why the nonwoven fabric of the present disclosure is excellent in hydrophilicity and suppresses migration of the hydrophilizing agent when in contact with other members is not clear, but the present inventors speculate as follows. Among the hydrophilizing agents contained in the nonwoven fabric of the present disclosure, the wetting agent is considered to have the effect of imparting hydrophilicity to the nonwoven fabric. In addition, among the hydrophilizing agents, the specific penetrating agent mentioned above is considered to be excellent in the action of penetrating the wetting agent into the fibers constituting the nonwoven fabric. The nonwoven fabric of the present disclosure has a surface water vapor adsorption area/surface nitrogen adsorption area of 2.0 to 5.8. If this area ratio is too large, the hydrophilizing agent tends to migrate when in contact with other members, although the hydrophilicity is excellent. On the other hand, if this area ratio is too small, migration of the hydrophilizing agent is suppressed when it comes into contact with other members, but the hydrophilicity is low. Of the hydrophilizing agents, those having high hydrophilicity can obtain high hydrophilicity with a small coating amount, but are likely to migrate to other members. Also, this area ratio tends to increase. If the hydrophilicity is low, it is difficult to obtain sufficiently high hydrophilicity with a small coating amount, but migration to other members is unlikely to occur, and the area ratio tends to be low. Therefore, when the area ratio is within the above range, the hydrophilicity of the fibers constituting the nonwoven fabric and the amount of the hydrophilizing agent contained in the nonwoven fabric are well balanced. As a result, it is believed that the nonwoven fabric of the present disclosure is excellent in hydrophilicity, and migration of the hydrophilizing agent is suppressed even when in contact with other members.

In the nonwoven fabric of the present disclosure, the method for incorporating the hydrophilic agent is not particularly limited, and the nonwoven fabric may be obtained by either a kneading method or a coating method. The nonwoven fabric of the present disclosure has a higher effect of suppressing migration of the hydrophilizing agent to other members in the nonwoven fabric obtained by the coating method than in the nonwoven fabric obtained by the kneading method.

(hydrophilic agent)
Nonwoven fabrics of the present disclosure include penetrants and wetting agents (ie, hydrophilizing agents). The penetrant includes at least one of sulfonate and sulfate.

[Penetrant]
Examples of sulfonates include alkylbenzenesulfonates, alkylnaphthalenesulfonates, α-olefinsulfonates, and alkylsulfosuccinates. These sulfonates are preferably alkali metal salts of sulfonic acid. Sulfate salts include higher alcohol sulfates, alkyl sulfates, and the like. These sulfates are preferably alkali metal salts of sulfates. Among these, the penetrant preferably contains a sulfonate, more preferably an alkali metal salt of sulfonic acid.

The sulfonate used as the penetrating agent is preferably an alkyl sulfosuccinate from the viewpoint of suppressing migration of the hydrophilizing agent when in contact with other members. The alkyl sulfosuccinate is more preferably an alkali metal salt of dialkyl sulfosuccinic acid, more preferably a sodium (Na) dialkyl sulfosuccinate, and a dialkyl having two alkyl groups having 8 to 16 carbon atoms. Alkali metal salts of sulfosuccinic acid are more preferred. Specific examples of the alkali metal salt of dialkylsulfosuccinic acid having two alkyl groups having 8 to 16 carbon atoms include sodium dioctylsulfosuccinate, sodium di(2-ethylhexyl)sulfosuccinate, and didecyl. Sulfosuccinic acid sodium salt, didodecylsulfosuccinic acid sodium salt, ditetradecylsulfosuccinic acid lithium (Li) salt, dihexadecylsulfosuccinic acid potassium (K) salt and the like. Among these, sodium di(2-ethylhexyl)sulfosuccinate is preferred from the viewpoint of suppressing migration of the hydrophilizing agent when in contact with other members.

[Wetting agent]
The wetting agent is not particularly limited, and may be a cationic surfactant, an anionic surfactant, an amphoteric surfactant, or a nonionic surfactant.

Examples of cationic surfactants include alkyl (or alkenyl) trimethylammonium halides, dialkyl (or alkenyl) quaternary ammonium salts represented by dimethylammonium halides, alkylamine salts, and alkylene oxide adducts thereof. . Examples of anionic surfactants include phosphate salts such as sodium lauryl phosphate and fatty acid salts such as sodium laurate. Examples of amphoteric surfactants include salts of these cationic surfactants and anionic surfactants.

The wetting agent is preferably a nonionic surfactant from the viewpoint of imparting excellent hydrophilicity. Nonionic surfactants that are wetting agents include, for example, polyhydric alcohol fatty acid esters, polyoxyalkylene fatty acid esters, alkylpolyoxyethylene alcohols, alkylene oxide adducts of polyhydric alcohol fatty acid esters, alkoxylated alkylphenols, fatty acid amides, Examples include nonionic surfactants such as alkyldiethanolamides and polyoxyalkylenes. Among these, from the viewpoint of imparting excellent hydrophilicity, it is preferable to include at least one selected from the group consisting of polyhydric alcohol fatty acid esters, polyoxyalkylene fatty acid esters, and alkylene oxide adducts of glycerin fatty acid esters. The polyhydric alcohol fatty acid ester, the polyoxyalkylene fatty acid ester, and the alkylene oxide adduct of the polyhydric alcohol fatty acid ester may be monoesters, diesters, and triesters, respectively. Polyhydric alcohol fatty acid esters, polyoxyalkylene fatty acid esters, and alkylene oxide adducts of polyhydric alcohol fatty acid esters may each contain one of monoesters, diesters, and triesters alone; It may contain more than seeds.

Polyhydric alcohol fatty acid esters include glycerin fatty acid esters and sorbitan fatty acid esters. Both glycerin fatty acid esters and sorbitan fatty acid esters are preferably esters of glycerin or sorbitan with fatty acids having 10 to 20 carbon atoms. Specific examples include glycerin lauric acid monoester, glycerin oleic acid diester, glycerin oleic acid triester, sorbitan lauric acid monoester, sorbitan lauric acid diester, and sorbitan lauric acid triester.

Polyoxyalkylene fatty acid esters include polyoxyethylene fatty acid esters and polyoxypropylene fatty acid esters. Among these, polyoxyethylene fatty acid esters are preferred. The polyoxyethylene fatty acid ester preferably has 10 to 20 carbon atoms in the fatty acid and 5 to 20 moles of the ethylene oxide chain (also referred to as EO chain). Specific examples include polyoxyethylene stearate monoester, polyoxyethylene laurate monoester, polyoxyethylene laurate diester, polyoxyethylene oleate monoester, and polyoxyethylene oleate diester.

Examples of alkylene oxide adducts of polyhydric alcohol fatty acid esters include ethylene oxide adducts of polyhydric alcohol fatty acid esters and propylene oxide adducts of polyhydric alcohol fatty acid esters. Among these, the alkylene oxide adduct of a polyhydric alcohol fatty acid ester is preferably an ester of glycerin and a fatty acid having 10 to 20 carbon atoms and has 5 to 20 moles of ethylene oxide added. Specifically, polyoxyethylene glycerin lauric acid monoester, polyoxyethylene glycerin lauric acid diester, polyoxyethylene glycerin lauric acid triester, polyoxyethylene sorbitan oleic acid monoester, polyoxyethylene sorbitan oleic acid diester, polyoxy Ethylene sorbitan oleic acid triester and the like can be mentioned.

From the viewpoint of imparting excellent hydrophilicity, the wetting agent preferably contains a combination of a polyhydric alcohol fatty acid ester, an alkylene oxide adduct of the polyhydric alcohol fatty acid ester, and a polyoxyalkylene fatty acid ester. It is also preferable that the wetting agent is a combination of a polyhydric alcohol fatty acid ester and a polyoxyalkylene fatty acid ester.

Combinations of polyhydric alcohol fatty acid esters, alkylene oxide adducts of polyhydric alcohol fatty acid esters, and polyoxyalkylene fatty acid esters include glycerin fatty acid esters, ethylene oxide adducts of polyhydric alcohol fatty acid esters, and polyoxyethylene fatty acids. A combination with an ester is more preferred. A combination of glycerin oleate diester, polyoxyethylene glycerin laurate diester and triester, and polyoxyethylene laurate diester is more preferred.

As a combination of a polyhydric alcohol fatty acid ester and an alkylene oxide adduct of a polyhydric alcohol fatty acid ester, a combination of a glycerin fatty acid ester and an alkylene oxide adduct of a polyhydric alcohol fatty acid ester is more preferable. Combinations of glycerin oleate diesters and glycerin oleate triesters with polyoxyethylene oleate monoesters and polyoxyethylene oleate diesters are more preferred.
As a combination of polyhydric alcohol fatty acid ester and polyoxyalkylene fatty acid ester, a combination of sorbitan lauric acid monoester, diester or triester and polyoxyethylene lauric acid monoester or diester is preferable. Furthermore, in addition to these sorbitan laurate and polyoxyethylene laurate, it is also preferable to combine polyoxyethylene sorbitan oleate monoester, polyoxyethylene sorbitan oleate diester and polyoxyethylene sorbitan oleate triester. .

The ratio of penetrant to wetting agent (penetrant/wetting agent) is preferably 1/99 to 60/40 by weight. More preferably, this ratio is between 5/95 and 50/50, and even more preferably between 10/90 and 40/60. When the mass ratio of the wetting agent/penetrating agent is within this range, the hydrophilicity is excellent, and migration of the hydrophilizing agent when in contact with other members is easily suppressed.

The hydrophilizing agent is obtained by adding a total of 0.02 g of the above hydrophilizing agent (that is, a combination of the penetrating agent and the wetting agent) to 20 ml of a 1/1 (mass ratio) mixture of hexane and water. When the mixed liquid after the addition of the agent is stirred, it is preferable that the mixture separates into an oil phase and an aqueous phase after 1 minute (hereinafter also referred to as a separation test of the hydrophilizing agent). This segregation test is believed to be indicative of the affinity of the hydrophilizing agent as a whole to water or thermoplastic polymer fibers. When the hydrophilizing agent separates into an oil phase and an aqueous phase, it has a higher affinity for water, and when it does not separate, it has a higher affinity for the fibers of the thermoplastic polymer. Therefore, by using a hydrophilizing agent that separates in the above separation test, the hydrophilicity tends to be further improved. The hydrophilizing agent exhibiting such properties preferably has a mass ratio of penetrating agent/wetting agent in the range of 1/99 to 60/40, more preferably in the range of 10/90 to 40/60. .

For example, in the separation test of the hydrophilizing agent, when the nonwoven fabric to be measured is analyzed, the measurement may be performed as follows. First, 100 g or more of nonwoven fabric is prepared. Next, the prepared nonwoven fabric is immersed in ethanol and allowed to stand at 25° C. for 24 hours to obtain an extract A. The nonwoven fabric is immersed in another ethanol and allowed to stand at 25° C. for 24 hours to obtain an extract B. Extract liquid A and extract liquid B are heated to 80° C. while being degassed to sufficiently remove ethanol to obtain a residue. The residue is then mixed and subjected to a hydrophilizing agent separation test.

The coating amount of the hydrophilizing agent is preferably 0.1% by mass to 2.0% by mass. The coating amount of the hydrophilizing agent is more preferably 0.2% by mass to 1.5% by mass, more preferably 0.3% by mass to 1.2% by mass. When the coating amount of the hydrophilizing agent is within this range, the hydrophilicity is excellent, and migration of the hydrophilizing agent when in contact with other members is easily suppressed. The amount of the hydrophilizing agent applied is the mass of the nonwoven fabric after the hydrophilizing agent has been applied, minus the mass of the nonwoven fabric before the hydrophilizing agent has been applied. expressed as a percentage divided by

(Thermoplastic polymer fiber)
The fibers of the thermoplastic polymer are not particularly limited as long as they can form a nonwoven fabric. Specific examples of the thermoplastic polymer constituting the fiber include olefin-based polymers, polyester-based polymers, polyamide-based polymers, polymer compositions containing these polymers, and the like. An olefinic polymer is a polymer mainly composed of olefin-derived structural units. A polyester-based polymer is a polymer containing polyester as a structural unit. A polyamide-based polymer is a polymer containing polyamide as a structural unit. In addition, in this disclosure, a thermoplastic polymer is a concept including a thermoplastic polymer composition.

Among these, the thermoplastic polymer is preferably an olefin polymer composition, more preferably a propylene polymer composition. An olefinic polymer composition refers to a polymer composition mainly containing an olefinic polymer. A propylene-based polymer composition refers to a polymer composition mainly containing a propylene-based polymer. The propylene-based polymer and the polymer composition mainly containing the propylene-based polymer will be described below.

[Propylene polymer composition]
The propylene-based polymer composition is not particularly limited as long as it is a polymer composition mainly containing a propylene-based polymer. For example, the propylene-based polymer composition may be a propylene-based polymer composition containing two or more different propylene-based polymers, or a propylene-based polymer composition containing a propylene-based polymer and an ethylene-based polymer. may be The propylene-based polymer is a polymer mainly composed of propylene-derived structural units, and is a concept including propylene homopolymers and copolymers of propylene and α-olefins other than propylene. An ethylene-based polymer is a polymer mainly composed of ethylene-derived structural units, and is a concept including ethylene homopolymers and copolymers of ethylene and α-olefins other than ethylene.

From the viewpoint of the strength and stretchability of the nonwoven fabric, the propylene-based polymer composition is a propylene-based polymer composition containing a propylene-based polymer (A) having a melting point of 130° C. or higher and an ethylene-based polymer (B). is preferred. From the same point of view, the propylene-based polymer composition preferably contains 100 parts by mass of the propylene-based polymer (A) having a melting point of 130° C. or higher and 1 to 10 parts by mass of the ethylene-based polymer (B). preferable. A propylene-based polymer composition containing 100 parts by mass of a propylene-based polymer (A) having a melting point of 130° C. or higher and 2 to 8 parts by mass of an ethylene-based polymer (B) is more preferable. If necessary, components such as an ethylene polymer wax (C) described later and a propylene polymer (D) shown in (III) may be included.

-Propylene polymer (A)-
The propylene-based polymer (A) is not particularly limited as long as it has a melting point of 130° C. or higher, and may be either a propylene homopolymer or a copolymer of propylene and an α-olefin other than propylene. From the viewpoint of the strength and stretchability of the nonwoven fabric, the melting point of the propylene-based polymer (A) is preferably 130°C or higher, more preferably 140°C or higher, and even more preferably 150°C or higher. Moreover, the melting point of the propylene-based polymer (A) is preferably 170° C. or lower.

The content of the propylene-based polymer (A) is preferably 50% by mass or more, preferably 70.0% by mass or more, and 99.0% by mass or more, based on the total mass of the fibers of the thermoplastic polymer, from the viewpoint of the strength and extensibility of the nonwoven fabric. 0% by mass or less is more preferable, and 85.0% by mass or more and 97.0% by mass or less is even more preferable.

As the propylene-based polymer (A), a commercially available product may be used as it is, or it may be synthesized by various known methods.

The melt flow rate (MFR: ASTM D1238, 230° C., load 2160 g) of the propylene-based polymer (A) is not particularly limited as long as melt spinning is possible. For example, the MFR may be from 1 g/10 min to 1000 g/10 min, preferably from 5 g/10 min to 500 g/10 min, more preferably from 10 g/10 min to 100 g/10 min. .

The propylene-based polymer (A) may be used alone in the propylene-based polymer composition, or two or more different types having different melting points, molecular weights, crystal structures, and the like may be used.

- Ethylene polymer (B) -
The ethylene-based polymer (B) is not particularly limited as long as it is a polymer mainly composed of ethylene-derived structural units, and may be either an ethylene homopolymer or a copolymer of ethylene and an α-olefin other than ethylene. good. Specific examples of the ethylene-based polymer (B) include high-pressure low-density polyethylene (so-called LDPE), linear low-density polyethylene (so-called LLDPE), medium-density polyethylene (so-called MDPE), high-density polyethylene (so-called HDPE), and the like. is mentioned.

The density of the ethylene-based polymer (B) is preferably 0.930 g/cm ³ to 0.980 g/cm ³ from the viewpoint of extensibility and flexibility of the nonwoven fabric. In particular, from the viewpoint of spinnability and strength, the density of the ethylene polymer (B) is preferably 0.940 g/cm ³ to 0.980 g/cm ³ , more preferably 0.940 g/cm ³ to 0.940 g/cm 3 More preferably 0.975 g/cm ³ . Particularly preferred is high density polyethylene (HDPE) in the range of 0.950 g/cm ³ to 0.970 g/cm ³ . Density is a value obtained by measuring according to the density gradient method of JIS K7112 (1999).

The melt flow rate (MFR: ASTM D1238, 190° C., load 2160 g) of the ethylene polymer (B) is not particularly limited as long as melt spinning is possible. The melt flow rate of the ethylene polymer (B) is preferably 1 g/10 minutes to 50 g/10 minutes. The melt flow rate of the ethylene polymer (B) is more preferably 2 g/10 minutes to 25 g/10 minutes, even more preferably 2 g/10 minutes to 10 g/10 minutes.

As the ethylene polymer (B), polymers obtained by various known production methods (for example, a high pressure method, a medium and low pressure method obtained using a Ziegler catalyst or a metallocene catalyst) can be used. Among these polymers, when an ethylene-based polymer obtained by polymerization with a metallocene-based catalyst is used, the spinnability of the propylene-based polymer composition is improved, and the resulting spunbonded nonwoven fabric has improved strength and the like. It is preferable from the viewpoint of improvement.

The ethylene-based polymer (B) may be used alone in the propylene-based polymer composition, or two or more of them having different melting points, molecular weights, crystal structures, and the like may be used.

- Ethylene Polymer Wax (C) -
As another aspect, the propylene-based polymer composition may further contain an ethylene-based polymer wax (C) having a weight average molecular weight (Mw) of 400 to 30,000, if necessary. The ethylene polymer wax (C) is not particularly limited as long as it has a weight average molecular weight (Mw) of 400 to 30,000.
In the present disclosure, the ethylene-based polymer wax (C) refers to a wax-like polymer having a lower molecular weight than the ethylene-based polymer (B).

The ethylene polymer wax (C) may be either an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms.
When a copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms is used as the ethylene polymer wax (C), the α-olefin to be copolymerized with ethylene preferably has 3 to 8 carbon atoms. , more preferably 3 or 4 carbon atoms, and still more preferably 3 carbon atoms.
When the number of carbon atoms in the α-olefin to be copolymerized with ethylene is within the above range, spinnability is improved, and properties such as strength of the nonwoven fabric can be enhanced.
When an ethylene homopolymer is used as the ethylene-based polymer wax (C), it is excellent in kneadability with the ethylene-based polymer (B) and excellent in spinnability.

The weight average molecular weight (Mw) of the ethylene polymer wax (C) is preferably 15,000 or less. It is preferably less than 15,000, more preferably 9,000 or less, even more preferably 6,000 or less, particularly preferably less than 6,000, and most preferably 5,000 or less. The lower limit is preferably 400 or more, more preferably 1000 or more. When the weight average molecular weight (Mw) of the ethylene-based polymer wax (C) is within the above range, the spinnability of the propylene-based polymer composition is likely to be improved, the fiber diameter is likely to be reduced, and furthermore, stability is easily obtained.

The weight average molecular weight (Mw) of the ethylene-based polymer wax (C) is a value determined by a gel permeation chromatography (GPC) method and measured under the following conditions.
The weight-average molecular weight is obtained by preparing a calibration curve using a commercially available monodisperse standard polystyrene and using the following conversion method.

Apparatus: Gel permeation chromatograph Alliance GPC2000 type (manufactured by Waters)
Solvent: o-dichlorobenzene Column: TSKgel column (manufactured by Toso Corporation) x 4
Flow rate: 1.0 ml/min Sample: 0.15 mg/mL Lo-dichlorobenzene solution Temperature: 140°C
Molecular weight conversion: PE conversion/general-purpose calibration method For the calculation of general-purpose calibration, the coefficients of the Mark-Houwink viscosity formula shown below were used.
Coefficient of polystyrene (PS): KPS = 1.38 × 10 ^-4 , aPS = 0.70
Coefficients of polyethylene (PE): KPE=5.06×10 ⁻⁴ , aPE=0.70

The ethylene polymer wax (C) preferably has a softening point of 90°C to 145°C, more preferably 90°C to 130°C, as measured according to JIS K2207 (2006).

From the viewpoint of stable spinning, the content of the ethylene polymer wax (C) is preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the propylene polymer (A). It is preferably from 0.5 parts by mass to 5 parts by mass.

The method for producing the ethylene-based polymer wax (C) is not particularly limited, and may be a commonly used production method by polymerization of a low-molecular-weight polymer, or a method of reducing the molecular weight by heating and degrading a high-molecular-weight ethylene-based polymer. It may be any manufacturing method such as.

The ethylene-based polymer wax (C) may also be purified by a method such as solvent fractionation for fractionation based on the difference in solubility in a solvent, or distillation.
When the ethylene-based polymer wax (C) is obtained by a commonly used production method involving polymerization of a low-molecular-weight polymer, various known production methods such as Ziegler/Natta catalysts and JP-A-08-239414, It can be produced by the production method of polymerizing with a metallocene catalyst or the like, described in International Publication No. 2007/114102, or the like.

The density of the ethylene-based polymer wax (C) is not particularly limited, and is preferably 0.890 g/cm ³ to 0.980 g/cm ³ , more preferably 0.910 g/cm ³ or more. More preferably, it is 0.920 g/cm ³ or more.
The density of the ethylene polymer wax (C) is preferably 0.960 g/cm ³ or less, more preferably 0.950 g/cm ³ or less. When the ethylene-based polymer wax (C) having a density within the above range is used, the spinnability tends to be excellent.

The ethylene-based polymer wax (C) may be used alone in the propylene-based polymer composition, or two or more different ones having different melting points, molecular weights, crystal structures, etc. may be used.

-Propylene-based polymer (D) shown in (III)-
As another aspect, the propylene-based polymer composition may optionally contain a propylene-based polymer (D) shown in (III) below. The content of the propylene-based polymer shown in (III) below (hereinafter also referred to as polymer (III)) is preferably more than 0 parts by mass and not more than 25 parts by mass in the propylene-based polymer composition.

(III) Propylene homopolymer having a melting point of less than 120°C satisfying the following (a) to (f) (a) [mmmm] = 20 mol% to 60 mol%
(b) [rrrr]/(1−[mmmm])≦0.1
(c) [rmrm] > 2.5 mol%
(d) [mm]×[rr]/[mr]2≦2.0
(e) Weight average molecular weight (Mw) = 10,000 to 200,000
(f) molecular weight distribution (Mw/Mn) <4
In (a) to (d), [mmmm] is the mesopentad fraction, [rrrr] is the racemic pentad fraction, [rmrm] is the racemic meso-racemic mesopentad fraction, [m
m], [rr] and [mr] are triad fractions respectively.

The mesopentad fraction [mmmm], the racemic pentad fraction [rrrr], the racemic meso-racemic mesopentad fraction [rmrm], the triad fraction [mm], [rr] and [mr] of the polymer (III) are , as detailed below, can be calculated according to the method proposed by A. Zambelli et al. in Macromolecules, 6, 925 (1973).

(a) [mmmm] = 20 to 60 mol%:
When the mesopentad fraction [mmmm] of the polymer (III) is 20 mol% or more, stickiness is suppressed. good properties. The mesopentad fraction [mmmm] is preferably 30 mol % to 50 mol %, more preferably 40 mol % to 50 mol %.

The mesopentad fraction [mmmm], the racemic pentad fraction [rrrr] and the racemic meso-racemic mesopentad fraction [rmrm], which will be described later, are described by A. Zambelli et al. in "Macromolecules, 6, 925 (1973). ” and is the meso fraction, racemic fraction, and racemic meso racemic meso fraction in the pentad unit in the polypropylene molecular chain measured by the methyl group signal in the ¹³ C-NMR spectrum. . Stereoregularity increases as the mesopentad fraction [mmmm] increases. In addition, triad fractions [mm], [rr] and [mr], which will be described later, are also calculated by the above method.

^{The 13} C-NMR spectrum can be measured using the following equipment and conditions according to the peak assignments proposed by A. Zambelli et al. in "Macromolecules, 8, 687 (1975)".

Apparatus: JNM-EX400 type ¹³ C-NMR apparatus manufactured by JEOL Ltd. Method: Proton complete decoupling method Concentration: 220 mg/ml
Solvent: 90:10 (volume ratio) mixed solvent of 1,2,4-trichlorobenzene and deuterated benzene Temperature: 130°C
Pulse width: 45°
Pulse repetition time: 4 seconds Accumulation: 10000 times

[a formula]
M=m/S×100
R=γ/S×100
S = Pββ + Pαβ + Pαγ
S: Signal intensity Pββ of side chain methyl carbon atoms of all propylene units: 19.8 to 22.5 ppm
Pαβ: 18.0 to 17.5 ppm
Pαγ: 17.5 to 17.1 ppm
γ: racemic pentad chain: 20.7 to 20.3 ppm
m: mesopentad chain: 21.7 to 22.5 ppm

(b) [rrrr]/(1−[mmmm])≦0.1
The value of [rrrr]/[1-mmmm] is obtained from the above fraction of pentad units, and is an index showing the uniformity of the regular distribution of the structural units derived from propylene in the polymer (III). If this value becomes large, it becomes a mixture of highly regular polypropylene and atactic polypropylene like conventional polypropylene produced using an existing catalyst system, which causes stickiness.
When [rrrr]/(1−[mmmm]) in the polymer (III) is 0.1 or less, stickiness in the resulting elastic nonwoven fabric is suppressed. From this point of view, [rrrr]/(1-[mmmm]) is preferably 0.05 or less, more preferably 0.04 or less.

(c) [rmrm] > 2.5 mol%
When the racemic-meso-racemic-meso fraction [rmrm] of the polymer (III) exceeds 2.5 mol %, the randomness of the polymer (III) increases. [rmrm] is preferably 2.6 mol % or more, more preferably 2.7 mol % or more. In addition, the upper limit is usually about 10 mol %.

(d) [mm]×[rr]/[mr] ² ≦2.0
[mm]×[rr]/[mr] ² indicates an index of randomness of polymer (III), and stickiness is also suppressed. As [mm]×[rr]/[mr] ² approaches 0.25, the randomness increases. From the viewpoint of obtaining sufficient elastic recovery, [mm]×[rr]/[mr] ² is preferably more than 0.25 and 1.8 or less, and is 0.5 to 1.5. is more preferred.

(e) Weight average molecular weight (Mw) = 10,000 to 200,000
When the weight average molecular weight of the polymer (III) is 10,000 or more, the viscosity of the polymer (III) is not too low and moderate. Therefore, yarn breakage is suppressed when a nonwoven fabric is produced by the spunbond method. Further, when the weight average molecular weight is 200,000 or less, the viscosity of the polymer (III) is not too high and the spinnability is improved. The weight average molecular weight is preferably 30,000 to 150,000, more preferably 50,000 to 150,000. A method for measuring the weight average molecular weight of polymer (III) will be described later.

(f) molecular weight distribution (Mw/Mn) <4
When the polymer (III) has a molecular weight distribution (Mw/Mn) of less than 4, the resulting spunbond nonwoven fabric is less sticky. This molecular weight distribution is preferably 3 or less.
The weight average molecular weight (Mw) is a polystyrene-equivalent weight average molecular weight measured by the gel permeation chromatography (GPC) method using the following apparatus and conditions, and the molecular weight distribution (Mw/Mn) is measured in the same manner. It is a value calculated from the measured number average molecular weight (Mn) and the weight average molecular weight (Mw).

[GPC measurement device]
Column: TOSO GMHHR-H(S)HT
Detector: RI detector for liquid chromatogram WATERS 150C
[Measurement condition]
Solvent: 1,2,4-trichlorobenzene Measurement temperature: 145°C
Flow rate: 1.0 ml/min Sample concentration: 2.2 mg/ml
Injection volume: 160 μl
Calibration curve: Universal Calibration
Analysis program: HT-GPC (Ver.1.0)

Polymer (III) preferably further satisfies the following requirement (g).
(g) Using a differential scanning calorimeter (DSC), observed on the highest temperature side of the melting endothermic curve obtained by holding at −10° C. for 5 minutes in a nitrogen atmosphere and then raising the temperature at 10° C./min. The melting point (Tm-D) defined as the peak top of the peak is 0°C to 120°C.

When the melting point (Tm-D) of the polymer (III) is 0°C or higher, the occurrence of stickiness of the spunbond nonwoven fabric formed from the propylene-based polymer composition is suppressed. Elastic recovery is obtained. From such a point of view, the melting point (Tm-D) is more preferably 0°C to 100°C, still more preferably 30°C to 100°C.

The melting point (Tm-D) was measured using a differential scanning calorimeter (Perkin-Elmer Co., DSC-7), holding 10 mg of the sample at −10° C. for 5 minutes in a nitrogen atmosphere, and measuring the temperature at 10° C./min. It can be determined as the peak top of the peak observed on the highest temperature side of the melting endothermic curve obtained by raising the temperature at .

Polymer (III) can be synthesized, for example, using a homogeneous catalyst called a metallocene catalyst (see, for example, International Publication No. 2003/087172).

The propylene-based polymer (D) shown in (III) above may be used alone in the propylene-based polymer composition, or two or more different types having different melting points, molecular weights, crystal structures, etc. may be used. good.

It can be appropriately confirmed by a known method that the fibers of the thermoplastic polymer (including the thermoplastic polymer composition) constituting the nonwoven fabric of the present disclosure contain each of the above components.

The basis weight of the nonwoven fabric of the present disclosure is not particularly limited. For example, the basis weight of the spunbond nonwoven fabric may be 5 g/m ² to 30 g/m ^{2 or 10 g/m 2 to} 25 g/m ² . .

The average fiber diameter of fibers constituting the nonwoven fabric is not particularly limited, and may be, for example, 5 μm to 25 μm. The average fiber diameter may be 20 μm or less, 18 μm or less, or 15 μm or less. Also, the average fiber diameter may be 7 μm or more, or may be 10 or more.

(Additive)
The propylene-based polymer composition may contain, as optional components, an antioxidant, a heat stabilizer, a weather stabilizer, an antistatic agent, a slip agent, an antifog agent, a lubricant, a dye, and a pigment as long as they do not impair the object of the present invention. , natural oils, synthetic oils, and waxes other than the ethylene-based polymer wax (C).

The nonwoven fabric of the present disclosure may contain other components as needed. Other components include, for example, antioxidants, heat stabilizers, weather stabilizers, antistatic agents, slip agents, antifog agents, lubricants, dyes, pigments, light stabilizers, antiblocking agents, dispersants, and nucleating agents. , softeners, water repellents, fillers, natural oils, synthetic oils, waxes other than ethylene polymer wax (C), antibacterial agents, preservatives, matting agents, rust inhibitors, fragrances, antifoaming agents, Various known additives such as antifungal agents and insect repellents are included. These other components may be contained inside the fibers constituting the nonwoven fabric, or may be attached to the surface of the fibers.

Although the propylene-based polymer composition has been described as an example of the thermoplastic polymer that constitutes the fibers of the thermoplastic polymer, the thermoplastic polymer is not limited to this.

(Physical properties of nonwoven fabric)
The nonwoven fabric of the present disclosure is the ratio of the surface water vapor adsorption area in the water vapor adsorption test obtained by the BET formula of the water vapor adsorption isotherm to the surface nitrogen adsorption area in the nitrogen adsorption test obtained from the BET formula of the nitrogen adsorption isotherm (surface water vapor adsorption area /surface nitrogen adsorption area) is 2.0 to 5.8. This area ratio is preferably 2.5 to 5.5, more preferably 3 to 5.5. This area ratio serves as an index of the balance between hydrophilicity and hydrophobicity per nonwoven fabric surface area. When the area ratio is within the above range, the nonwoven fabric is excellent in hydrophilicity, and migration of the hydrophilizing agent when in contact with other members is suppressed. A method for measuring the water vapor adsorption test obtained by the BET formula of the water vapor adsorption isotherm and a method for measuring the surface nitrogen adsorption area in the nitrogen adsorption test obtained by the BET formula of the nitrogen adsorption isotherm will be described in Examples below.

The surface water vapor adsorption area of the nonwoven fabric of the present disclosure is 0.5 m ² /g to 1.5 m 2 /g to 1.0 m 2 /g to 1.0 m 2 /g to 1.0 m 2 /g to 1.0 m 2 /g to 1.0 m 2 /g to 1.0 m 2 /g to 1.5 m 2 /g to 1.5 m 2 /g to 1.0 m 2 /g to 1.0 m 2 /g to 1.0 m 2 /g. It is preferably 2 m ² /g, more preferably 0.6 m ² /g to 1.2 m ² /g. The above range of the surface water vapor adsorption area and the above range of the area ratio of the surface water vapor adsorption area to the surface nitrogen adsorption area can be adjusted by adjusting the manufacturing conditions such as the type and amount of the hydrophilizing agent to be contained in the nonwoven fabric and the coating method. can be satisfied by

(Aspect of nonwoven fabric)
The nonwoven fabric of the present disclosure is not particularly limited, and may be either a long fiber nonwoven fabric or a short fiber nonwoven fabric. Specifically, nonwoven fabrics of the present disclosure can be exemplified by nonwoven fabrics produced by a spunbond method, a meltblown method, a flash spinning method, a wet method, a card method, an airlaid method, an electrostatic spinning method, and the like. From the viewpoint of productivity, the nonwoven fabric of the present disclosure is preferably a long-fiber nonwoven fabric. The long-fiber nonwoven fabric is preferably a nonwoven fabric manufactured by a spunbond method (that is, a spunbond nonwoven fabric) or a nonwoven fabric that is manufactured by a meltblown method (that is, a meltblown nonwoven fabric). A spunbond nonwoven fabric is particularly preferred.
In the present disclosure, "short fibers" generally mean fibers having an average fiber length of 200 mm or less. In addition, "long fiber" means "continuous filament" generally used in the technical field such as Nonwoven Handbook (edited by INDA American Nonwoven Fabric Industry Association, Nonwoven Information Co., Ltd., 1996). .

The nonwoven fabric of the present disclosure may be a single-layer nonwoven fabric or a multi-layer nonwoven fabric (nonwoven multilayer structure) in which a plurality of layers are laminated. The nonwoven fabric multilayer structure may be, for example, a multilayer structure in which a spunbond nonwoven fabric is laminated, or a multilayer structure in which a spunbond nonwoven fabric and a meltblown nonwoven fabric are laminated. When the nonwoven fabric of the present disclosure is a multilayer structure, it is preferred that all layers of the multilayer structure contain a hydrophilizing agent. In the present disclosure, a nonwoven fabric that is a multilayer structure containing a hydrophilizing agent is referred to as a nonwoven multilayer structure and is distinguished from a laminate described below.

<Method for manufacturing nonwoven fabric>
The method for obtaining the nonwoven fabric of the present disclosure is not particularly limited, and it is preferably produced by the following method.
An example of a preferred method for producing the nonwoven fabric of the present disclosure will be described below.
The nonwoven fabric manufacturing method of the present disclosure has the following steps.
A step of preparing a nonwoven fabric containing thermoplastic polymer fibers (nonwoven fabric preparation step).
A step of attaching a penetrant containing at least one of a sulfonate and a sulfate and a wetting agent to the nonwoven fabric (hydrophilic agent attaching step).
Then, in the hydrophilizing agent adhesion step, a specific penetrating agent and wetting agent (i.e., hydrophilizing agent) are adhered to the nonwoven fabric in an appropriate amount, so that the amount of the hydrophilizing agent attached to the fibers constituting the nonwoven fabric The ratio of the surface water vapor adsorption area in the water vapor adsorption test obtained by the BET formula of the water vapor adsorption isotherm to the surface nitrogen adsorption area in the nitrogen adsorption test obtained from the BET formula of the nitrogen adsorption isotherm (surface A nonwoven fabric having a water vapor adsorption area/surface nitrogen adsorption area) of 2.0 to 5.8 is obtained. For example, the surface water vapor adsorption area and the surface nitrogen adsorption area are determined by the conditions of the hydrophilizing agent (amount, type, composition of wetting agent and penetrating agent, etc.), manufacturing conditions (coating method, treatment process after coating, etc.), and these You can adjust the combination.

(Nonwoven fabric preparation process)
The nonwoven fabric preparing step is a step of preparing a nonwoven fabric to which the hydrophilizing agent is attached.
The nonwoven fabric to be prepared is not particularly limited, and a commercially available product may be prepared, or a nonwoven fabric may be produced. Moreover, the nonwoven fabric to be prepared may be a single-layer nonwoven fabric or a multi-layer nonwoven fabric. When manufacturing a nonwoven fabric, it may be manufactured by a known long-fiber nonwoven fabric manufacturing method or a known short-fiber nonwoven fabric manufacturing method. From the viewpoint of productivity, the nonwoven fabric to be prepared is preferably a long-fiber nonwoven fabric, more preferably a nonwoven fabric manufactured by a spunbond method. In the case of the spunbond method, for example, a step of melt-spinning a thermoplastic polymer to form continuous fibers (spinning step) and a step of collecting continuous fibers to form a nonwoven web (nonwoven web forming step). and a step of entangling the nonwoven web (entanglement step) to produce a spunbond nonwoven fabric. When the spunbond nonwoven fabric is composed of multiple layers, a step of forming second continuous fibers (second spinning step) may be provided between the nonwoven web forming step and the entangling step. Continuous fibers are collected on the first nonwoven web to form a second nonwoven web, followed by an entangling step to produce a multi-layered spunbond nonwoven fabric. The spinning process includes a known process of cooling and stretching.

(Hydrophilizing agent attachment step)
The hydrophilizing agent attaching step is a step of attaching the hydrophilizing agent to the nonwoven fabric prepared in the nonwoven fabric preparation step. The method of attachment is not particularly limited as long as the hydrophilizing agent can be attached to the nonwoven fabric. For example, the hydrophilic agent is preferably attached by a method of applying a solution of the hydrophilic agent in a solvent (e.g., a volatile organic solvent such as methanol, ethanol, and isopropyl alcohol, or water) to the nonwoven fabric. . Examples of the method for attaching the hydrophilic agent to the nonwoven fabric include known methods such as dipping (immersion), roll coating (gravure coating, kiss coating), spray coating, and die coating. In the present disclosure, “coating” is a concept including “dipping”.

In attaching a hydrophilizing agent to a nonwoven fabric, it is preferable to dissolve the hydrophilizing agent in a solvent such as water to form a solution of the hydrophilizing agent, and apply the solution of the hydrophilizing agent to the nonwoven fabric. From the viewpoint of facilitating application of the hydrophilizing agent solution, the hydrophilizing agent solution contains a penetrating agent and a wetting agent as active ingredients, and the total amount of the active ingredients is 0.1% by mass to 30% by mass. is preferred. The hydrophilizing agent solution may contain additives such as antibacterial agents, antioxidants, preservatives, delustering agents, pigments, rust inhibitors, fragrances, antifoaming agents, etc., depending on the purpose. .

(Other processes)
Other steps may be included after the step of attaching a hydrophilizing agent. Other steps include a squeezing step for removing excess hydrophilizing agent solution from the nonwoven fabric, a drying step for removing the solvent in the hydrophilizing agent solution, and the like.

The squeezing step is a step of removing excess hydrophilizing agent solution from the nonwoven fabric. In other words, it is a step of adjusting the amount of hydrophilizing agent applied to the nonwoven fabric. The above-mentioned surface water vapor adsorption area and application amount can also be adjusted by the type and amount of the hydrophilizing agent solution used in the coating step and the amount of the hydrophilizing agent solution removed in the squeezing step. In the squeezing step, for example, the non-woven fabric is passed through nip rolls, or squeezed by hand to remove excess hydrophilizing agent solution.

A drying process is a process of removing the unnecessary solvent derived from a hydrophilizing agent from a nonwoven fabric. The heating temperature and heating time in the drying step are not particularly limited as long as the solvent can be sufficiently removed. Drying conditions include, for example, exposure to an environment of 80° C. to 200° C. for 1 second to 24 hours.

<Laminate>
The laminate of the present disclosure may comprise the nonwoven fabric of the present disclosure. That is, the laminate of the present disclosure may have a structure in which the hydrophilic nonwoven fabric of the present disclosure and the separately hydrophilized nonwoven fabric of the present disclosure are laminated together. In addition, a structure in which the nonwoven fabric of the present disclosure and layers other than the nonwoven fabric of the present disclosure are laminated may be used. The other layer may be one layer, or two or more layers.

Other layers include fiber aggregates such as knitted fabrics, woven fabrics, and non-woven fabrics other than the non-woven fabrics of the present disclosure (short-fiber non-woven fabrics, long-fiber non-woven fabrics). Nonwoven fabrics other than the nonwoven fabrics of the present disclosure include various known nonwoven fabrics (spunbond nonwoven fabrics, meltblown nonwoven fabrics, wet nonwoven fabrics, dry nonwoven fabrics, dry pulp nonwoven fabrics, flash spun nonwoven fabrics, spread nonwoven fabrics, etc.). The fiber assembly may be a sheet of natural fibers such as cotton. Other layers include resin films such as polyolefin, polyester, and polyamide. These may be combined and laminated. For example, the nonwoven fabric of the present disclosure, a resin film, and a fiber aggregate of natural fibers such as cotton may be laminated in this order.

As the film to be laminated with the nonwoven fabric of the present disclosure, a breathable film and a moisture-permeable film are preferable when the laminate requires breathability.
Breathable films include various known breathable films. Examples thereof include films of thermoplastic elastomers such as polyurethane-based elastomers, polyester-based elastomers and polyamide-based elastomers having moisture permeability, and porous films obtained by stretching a thermoplastic resin film containing inorganic particles or organic particles to make it porous. . The thermoplastic resin used for the porous film includes polyolefins such as high-pressure low-density polyethylene, linear low-density polyethylene (so-called LLDPE), high-density polyethylene, polypropylene, polypropylene random copolymer, and combinations thereof.
If the nonwoven fabric laminate does not require air permeability, one or more non-porous thermoplastic resin films selected from polyolefins (polyethylene, polypropylene, etc.), polyesters, and polyamides may be used.

The method of further laminating (bonding) other layers to the nonwoven fabric of the present disclosure is not particularly limited, and includes thermal embossing, thermal fusion bonding such as ultrasonic fusion, needle punching, mechanical interlacing such as water jet, Various methods such as a method using an adhesive such as a hot-melt adhesive and a urethane-based adhesive, and extrusion lamination can be used.

<Coating sheet>
A cover sheet of the present disclosure includes a nonwoven fabric of the present disclosure. The covering sheet of the present disclosure is not particularly limited as long as it contains the nonwoven fabric of the present disclosure. It may be a laminate. From the viewpoint of imparting functionality, the covering sheet of the present disclosure preferably contains the laminate of the present disclosure. A covering sheet of the present disclosure refers to a sheet for covering at least a portion of an object of interest. Applications to which the coating sheet is applied are not particularly limited, and include various applications. Specific examples of the covering sheet include absorbent articles (disposable diapers, disposable pants, sanitary products, incontinence pads, pet sheets, etc.), cosmetic materials (face masks, etc.); sanitary materials (poultices, sheets, towels, industrial masks, sanitary masks, hair caps, etc.);

EXAMPLES The present invention will be described in more detail based on examples below, but the present invention is not limited to these examples. In addition, in the following examples, "%" represents mass %.

Physical properties and the like in Examples and Comparative Examples were measured by the following methods.

(1) basis weight [g/m ² ]
Ten test pieces of 100 mm (flow direction: MD) x 100 mm (direction perpendicular to the flow direction: CD) were sampled from the obtained nonwoven fabric. Ten test pieces were collected in the CD direction. Then, the mass [g] was measured for each test piece taken under an environment of 23° C. and a relative humidity of 50% using a top-pan electronic balance (manufactured by Kensei Kogyo Co., Ltd.). An average value of the mass of each test piece was obtained. The obtained average value was converted to mass [g] per 1 m ² , rounded off to the second decimal place, and determined as basis weight [g/m ² ] of each nonwoven fabric sample.

(2) Liquid flow distance (mm)
The obtained nonwoven fabric was cut into a size of 100 mm x 200 mm and used as a sample. Five sheets of filter paper (No. 2, manufactured by Advantech) are stacked on a plate fixed at an angle of 45 degrees with respect to the horizontal direction. It was fixed on the plate together with the filter paper. In an environment of 25°C, 0.1 ml of artificial urine was dropped with a dropper from a height of about 10 mm in the direction perpendicular to the sample surface, and the droplet was dropped from the drop point to the point where the droplet was completely absorbed. was measured and defined as the liquid flow distance (mm).
The liquid flow distance was evaluated based on the following evaluation criteria. Table 1 shows the results.
As the artificial urine, an aqueous sodium chloride solution (9 g/liter) having a surface tension of 70±2 mN/m was used.

(3) Strike-through test EDANA (European Nonwovens Association) standard NWSP 070.8. Measured according to R0 (15). Among them, the results of the first time and the results of the third time were recorded.

(4) Evaluation of migratability of hydrophilizing agent The nonwoven fabric obtained in each example was cut into a size of 100 mm x 100 mm. A homopolypropylene nonwoven fabric having a basis weight of 25 g/m ² and containing no hydrophilizing agent (nonwoven fabric to be transferred) was cut into a size of 100 mm×100 mm. The two nonwoven fabrics were put together, and a weight of 4 kg having a cross-sectional area of 100 mm×100 mm was put thereon. In addition, in order to prevent transfer of the hydrophilizing agent to the weight and the floor surface, it may be wrapped with a film. The nonwoven fabric on which the weight was placed was left for one week in an environment of 60° C. and 80% RH. The nonwoven fabric to be transferred was taken out, 1 drop (0.02 ml) of water was dropped, and when the nonwoven fabric was soaked, hydrophilicity was expressed and it was judged that migration of the hydrophilizing agent was poor ("Poor" in Table 1). labels). When it did not permeate, hydrophilicity was not expressed, and it was judged that migration of the hydrophilizing agent was good (indicated as "good" in Table 1).

(5) Evaluation of Surface Water Vapor Adsorption Area in Water Vapor Adsorption Test Measured using BELSORP-max, an apparatus manufactured by Microtrack Bell Co., Ltd.
Specifically, it was carried out as follows. First, a sample of about 0.50 g to 1.0 g was taken from the nonwoven fabric and set in the device. Then, drying treatment was performed by vacuum evacuation at room temperature (25° C.) for 8 hours. Thereafter, water vapor was adsorbed at 25° C. while varying the introduction pressure, and a water vapor adsorption isotherm was measured by plotting the amount of water vapor adsorption for each introduction pressure. Then, the following BET formula was applied to determine the specific surface area [m ² /g] as the surface water vapor adsorption area. The BET formula is a formula that expresses the relationship between the adsorption equilibrium pressure P and the adsorption amount V at that pressure when adsorption equilibrium is established at a constant temperature.

(BET formula): P/(V( _P0 -P))=1/(Vm×C)+{((C-1)/(Vm×C))×(P/ _P0 )}
In the formula, P ₀ : saturated water vapor pressure (Pa), Vm: monomolecular layer adsorption amount (mg/g), C: parameter related to heat of adsorption (−)<0. This relational expression holds particularly well in the range of P/P ₀ =0.05 to 0.35.

(6) Ratio of the surface water vapor adsorption area to the surface nitrogen adsorption area Next, the test was performed from sampling in the same procedure as the water vapor adsorption test, except that nitrogen was used instead of water vapor, and the nitrogen adsorption isotherm was measured. . Then, the specific surface area as the surface nitrogen adsorption area was obtained by the above BET formula. From the specific surface area as the surface water vapor adsorption area obtained above and the specific surface area as the surface nitrogen adsorption area obtained above, the ratio is calculated by "(specific surface area with water vapor) ÷ (specific surface area with nitrogen)". asked.

(7) Measurement of coating amount The mass of the non-woven fabric before applying the hydrophilizing agent (pre-coating mass) and the mass of the non-woven fabric after coating and drying the hydrophilizing agent (mass after coating) are measured, and hydrophilized. The coating amount of the agent was calculated from the following formula.
Application amount (%) = (weight after application - weight before application) / weight after application x 100

<Example 1>
A spunbond having an average fiber diameter of 18 μm and a basis weight of 25 g/m ² by heat embossing after melt spinning is performed using the following propylene-based polymer composition and the obtained fibers are deposited on the collecting surface. A non-woven fabric (SB) was obtained.

(Propylene polymer composition)
Propylene-based polymer (A): Propylene homopolymer 1 (MFR (ASTM D1238, 230°C, load 2160g): 60 g/10 minutes, melting point 162°C, also referred to as "PP1") 100 parts by mass Ethylene-based polymer (B ): polyethylene (MFR (ASTM D1238, 190° C., load 2160 g): 5 g/10 min, density 0.964 g/cm ³ , melting point 164° C.) 4 parts by mass

The average fiber diameter is a value obtained as follows. Ten 10 mm×10 mm test pieces were taken from the obtained spunbond nonwoven fabric, and the diameter of the fiber was read to the first decimal place in μm using a Nikon ECLIPSE E400 microscope at 20× magnification. The diameter was measured at 20 arbitrary points for each test piece, and the average value was obtained.

Next, each component was dissolved in an aqueous solution so as to have the following mixing ratio, to obtain an aqueous solution of hydrophilizing agent A with a total amount of active ingredients of 5% by mass.

(Hydrophilizing agent A)
Di(2-ethylhexyl) sodium sulfosuccinate: 20% by mass
Glycerin oleic acid diester: 30% by mass
Polyoxyethylene glycerol lauric acid ester/polyoxyethylene glycerol trilauric acid ester = 4:6 (weight ratio) (8 mol adduct of EO chain): 20% by weight
Polyoxyethylene dilaurate (EO chain 8 mol adduct): 30% by mass
The blending ratio (% by mass) described above is the ratio of each component to the total mass of active ingredients in the hydrophilizing agent A, that is, in the aqueous solution of the hydrophilizing agent A.

Next, the obtained spunbond nonwoven fabric was immersed in an aqueous solution (active ingredient: 5% by mass) of hydrophilizing agent A described below, squeezed, and then dried in a drying oven at 100°C. When the mass of the hydrophilizing agent adhering to the nonwoven fabric was measured according to the measurement of the coating amount, the coating amount was 0.6% by mass. The physical properties of the nonwoven fabric obtained by adhering the hydrophilizing agent (hereinafter referred to as hydrophilized nonwoven fabric) were measured according to the methods described above.

<Example 2>
A hydrophilized nonwoven fabric was obtained in the same manner as in Example 1, except that an aqueous solution of hydrophilizing agent A with a total active ingredient content of 10% by mass was applied so that the coating amount was 0.9% by mass.

<Example 3>
A spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that the following propylene-based polymer composition was used. Then, in the same manner as in Example 1, a hydrophilizing agent was attached to the spunbond nonwoven fabric. Table 1 shows the physical properties of the obtained hydrophilized nonwoven fabric.

(Propylene polymer composition)
Propylene polymer (A): 100 parts by mass of propylene homopolymer (PP1) as in Example 1 Ethylene polymer (B): 4 parts by mass of polyethylene as in Example 1 Ethylene polymer wax (C) : Mitsui Chemicals, Inc., product name “Hi-Wax 110P” (density: 0.922 g/cm ³ , weight average molecular weight: 1200, softening point: 113° C.) 1 part by mass

<Example 4>
A spunbond nonwoven fabric was obtained in the same manner as in Example 3, except that the following propylene-based polymer composition was used. Then, in the same manner as in Example 1, a hydrophilizing agent was attached to the spunbond nonwoven fabric. Table 1 shows the physical properties of the obtained hydrophilized nonwoven fabric.

(Propylene polymer composition)
Propylene-based polymer (A): Propylene homopolymer 2 (MFR ((ASTM D1238, 230°C, load 2160g)): 35 g/10 minutes, melting point 160°C, also referred to as "PP2") 100 parts by mass,
Ethylene polymer (B): 4 parts by mass of the same polyethylene as in Example 1 Ethylene polymer wax (C): 1 part by mass of the same ethylene polymer wax as in Example 3

<Example 5>
A spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that the following propylene-based polymer composition was used. Then, in the same manner as in Example 1, a hydrophilizing agent was attached to the spunbond nonwoven fabric. Table 1 shows the physical properties of the obtained hydrophilized nonwoven fabric.

(Propylene polymer composition)
Propylene-based polymer (A): 100 parts by mass of the same propylene homopolymer (PP1) as in Example 1;
Ethylene-based polymer (B): 4 parts by mass of the same polyethylene as in Example 1 Propylene-based polymer (D): S901 (trade name) manufactured by Idemitsu Kosan Co., Ltd., satisfying the above-described (a) to (f) , 12 parts by mass of a propylene homopolymer having a melting point of less than 120 ° C.

<Example 6>
A spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that the following propylene-based polymer composition was used. Then, in the same manner as in Example 1, a hydrophilizing agent was attached to the spunbond nonwoven fabric. Table 1 shows the physical properties of the obtained hydrophilized nonwoven fabric.

(Propylene polymer composition)
Propylene-based polymer (A): 100 parts by mass of propylene-ethylene random polymer (MFR (ASTM D1238, 230°C, load 2160g): 60 g/10 minutes, melting point 142°C, also referred to as "PP3") Ethylene-based polymer ( B): 4 parts by mass of the same polyethylene as in Example 1

<Example 7>
A spunbond nonwoven fabric was obtained in the same manner as in Example 6, except that the following propylene-based polymer composition was used. Then, in the same manner as in Example 6, a hydrophilizing agent was adhered to the spunbond nonwoven fabric. Table 1 shows the physical properties of the obtained hydrophilized nonwoven fabric.

(Propylene polymer composition)
Propylene polymer (A): 100 parts by mass of the propylene/ethylene random copolymer (PP3) used in Example 6 Ethylene polymer (B): 4 parts by mass of the same polyethylene as in Example 1 Ethylene polymer wax (C): 1 part by mass of the same ethylene-based polymer wax as in Example 3

<Example 8>
A spunbond nonwoven fabric was obtained in the same manner as in Example 3, except that the following propylene-based polymer composition was used. Then, in the same manner as in Example 3, a hydrophilizing agent was adhered to the spunbond nonwoven fabric. Table 1 shows the physical properties of the obtained hydrophilized nonwoven fabric.

(Propylene polymer composition)
Propylene polymer (A): 100 parts by mass of propylene homopolymer (PP1) as in Example 1 Ethylene polymer (B): 8 parts by mass of polyethylene as in Example 1 Ethylene polymer wax (C) : 1 part by mass of the same ethylene-based polymer wax as in Example 3

<Example 9>
First, a spunbond nonwoven fabric was obtained in the same manner as in Example 3. Next, each component was dissolved in an aqueous solution so as to have the following mixing ratio, to obtain an aqueous solution of hydrophilizing agent B with a total active ingredient content of 5% by mass. Next, the resulting spunbond nonwoven fabric was immersed in an aqueous solution (active ingredient 5% by mass) of hydrophilizing agent B described below, squeezed, and then dried in a drying oven at 100°C to obtain a hydrophilized nonwoven fabric. When the mass of the hydrophilizing agent adhering to the obtained hydrophilized nonwoven fabric was measured according to the measurement of the coating amount, the coating amount was 0.5% by mass. Table 1 shows the physical properties of the obtained hydrophilized nonwoven fabric.

(Hydrophilizing agent B)
Di(2-ethylhexyl) sodium sulfosuccinate: 20% by mass
Glycerin oleate diester/glycerin oleate triester = 5:5 (mass ratio): 50% by mass
Polyoxyethylene oleic acid monoester (EO chain 10 mol adduct)/polyoxyethylene oleic acid diester (EO chain 10 mol adduct) = 6:4 (mass ratio): 30% by mass
The blending ratio (% by mass) described above is the ratio of each component to the total mass of active ingredients in the hydrophilizing agent B, that is, in the aqueous solution of the hydrophilizing agent B.

<Example 10>
A hydrophilized nonwoven fabric was obtained in the same manner as in Example 9, except that an aqueous solution of hydrophilizing agent B with a total active ingredient content of 10% by mass was applied so that the coating amount was 1% by mass.

<Example 11>
First, a spunbond nonwoven fabric was obtained in the same manner as in Example 3. Next, each component was dissolved in an aqueous solution so as to have the following mixing ratio, to obtain an aqueous solution of hydrophilizing agent C with a total active ingredient content of 10% by mass. Next, the obtained spunbond nonwoven fabric was immersed in an aqueous solution (10% by mass of active ingredient) of hydrophilizing agent C described below, squeezed, and then dried in a drying oven at 100° C. to obtain a hydrophilized nonwoven fabric. When the mass of the hydrophilizing agent adhering to the obtained hydrophilized nonwoven fabric was measured according to the measurement of the coating amount, the coating amount was 0.5% by mass. Table 1 shows the physical properties of the obtained hydrophilized nonwoven fabric.

(Hydrophilizing agent C)
Di(2-ethylhexyl) sodium sulfosuccinate: 20% by mass
Sorbitan laurate monoester/Sorbitan laurate diester/Sorbitan laurate triester = 2:3:5 (mass ratio): 20% by mass
Polyoxyethylene laurate monoester (EO chain 8 mol adduct)/polyoxyethylene laurate diester (EO chain 8 mol adduct) = 4:6 (mass ratio): 30% by mass
Polyoxyethylene sorbitan oleic acid monoester (8 mol EO chain adduct)/polyoxyethylene sorbitan oleic acid diester (8 mol EO chain adduct)/polyoxyethylene sorbitan oleic acid triester (8 mol EO chain adduct) = 1:6:3 (mass ratio): 30% by mass
The blending ratio (% by mass) described above is the ratio of each component to the total mass of active ingredients in the hydrophilizing agent C, that is, in the aqueous solution of the hydrophilizing agent C.

<Comparative Example 1>
A hydrophilized nonwoven fabric was obtained in the same manner as in Example 1, except that an aqueous solution of hydrophilizing agent A with a total active ingredient content of 10% by mass was applied so that the coating amount was 1.1% by mass.

<Comparative Example 2>
A hydrophilized nonwoven fabric was obtained in the same manner as in Example 3, except that an aqueous solution of hydrophilizing agent C with a total active ingredient content of 10% by mass was applied so that the coating amount was 1.0% by mass.

<Comparative Example 3>
First, a spunbond nonwoven fabric was obtained in the same manner as in Example 3. Next, each component was dissolved in an aqueous solution so as to have the following mixing ratio, to obtain an aqueous solution of hydrophilizing agent D with a total amount of active ingredients of 5% by mass. Next, the obtained spunbond nonwoven fabric was immersed in an aqueous solution (active ingredient 5% by mass) of hydrophilizing agent D described below, squeezed, and then dried in a drying oven at 100°C to obtain a hydrophilized nonwoven fabric. When the mass of the hydrophilizing agent adhering to the obtained hydrophilized nonwoven fabric was measured according to the measurement of the coating amount, the coating amount was 0.6% by mass. Table 1 shows the physical properties of the obtained hydrophilized nonwoven fabric.

(Hydrophilizing agent D)
Glycerin oleic acid diester: 30% by mass
Polyoxyethylene glycerin lauric acid diester/polyoxyethylene glycerin lauric acid triester = 4:6 (mass ratio) (8 mol adduct of EO chain): 30% by mass
Polyoxyethylene laurate diester (EO chain 8 mol adduct): 40% by mass
The blending ratio (% by mass) described above is the ratio of each component to the total mass of active ingredients in the hydrophilizing agent D, that is, in the aqueous solution of the hydrophilizing agent D.

<Comparative Example 4>
A hydrophilized nonwoven fabric was obtained in the same manner as in Example 1, except that an aqueous solution of hydrophilizing agent A with a total active ingredient content of 2% by mass was applied so that the coating amount was 0.15% by mass.

From the above results, a nitrogen adsorption test obtained from the nitrogen adsorption isotherm BET formula containing a thermoplastic polymer fiber, a penetrant containing at least one of a sulfonate and a sulfate ester salt, and a wetting agent The ratio of the surface water vapor adsorption area in the water vapor adsorption test obtained by the BET formula of the water vapor adsorption isotherm to the surface nitrogen adsorption area in (surface water vapor adsorption area/surface nitrogen adsorption area) is 2.0 to 5.8 , the hydrophilicity is excellent, and migration of the hydrophilizing agent when in contact with other members is suppressed.

Claims (16)

fibers of a thermoplastic polymer;
a penetrant comprising at least one of a sulfonate and a sulfate;
a wetting agent;
contains
Ratio of the surface water vapor adsorption area in the water vapor adsorption test obtained by the BET formula of the water vapor adsorption isotherm to the surface nitrogen adsorption area in the nitrogen adsorption test obtained from the BET formula of the nitrogen adsorption isotherm (surface water vapor adsorption area/surface nitrogen adsorption area) is 2.0 to 5.8,
the wetting agent
a polyhydric alcohol fatty acid ester consisting of an ester of glycerin and a fatty acid having 10 to 20 carbon atoms;
an alkylene oxide adduct of a polyhydric alcohol fatty acid ester, which is an ester of glycerin and a fatty acid having 10 to 20 carbon atoms, wherein the number of moles of ethylene oxide added is 5 to 20;
Non-woven fabrics , including 2. The nonwoven fabric according to claim 1, wherein the surface water vapor adsorption area is 0.4 m ² /g to 1.2 m ² /g in the water vapor adsorption test obtained by the BET formula of the water vapor adsorption isotherm. 3. The nonwoven fabric of claim 1 or claim 2, wherein the sulfonate is an alkyl sulfosuccinate. The nonwoven fabric according to any one of claims 1 to 3, wherein the ratio of the penetrant to the wetting agent (penetrant/wetting agent) is 1/99 to 60/40 by weight. Claim 1, wherein the fibers comprise a propylene polymer composition containing 100 parts by mass of a propylene polymer (A) having a melting point of 130°C or higher and 1 to 10 parts by mass of an ethylene polymer (B). The nonwoven fabric according to any one of -claim 4. 6. The nonwoven fabric according to claim 5, wherein the ethylene polymer (B) has a density of 0.930 g/cm ³ to 0.980 g/cm ³ . The nonwoven fabric according to Claim 5 or Claim 6, wherein the propylene-based polymer composition further comprises an ethylene-based polymer wax (C) having a weight average molecular weight (Mw) of 400 to 30,000. 8. The nonwoven fabric according to claim 7, wherein the ethylene polymer wax (C) has a density of 0.890 g/cm ³ to 0.980 g/cm ³ . The propylene-based polymer composition according to any one of claims 5 to 8, wherein the propylene-based polymer (D) shown in (III) below is contained in an amount exceeding 0 parts by mass and 25 parts by mass or less. non-woven fabric.
(III) Propylene homopolymer having a melting point of less than 120°C satisfying the following (a) to (f) (a) [mmmm] = 20 mol% to 60 mol%
(b) [rrrr]/(1−[mmmm])≦0.1
(c) [rmrm] > 2.5 mol%
(d) [mm]×[rr]/[mr]2≦2.0
(e) Weight average molecular weight (Mw) = 10,000 to 200,000
(f) molecular weight distribution (Mw/Mn) <4
In (a) to (d), [mmmm] is the mesopentad fraction, [rrrr] is the racemic pentad fraction, [rmrm] is the racemic meso-racemic mesopentad fraction, [mm], [rr] and [mr] are triad fractions respectively. The nonwoven fabric according to any one of claims 1 to 9, having an average fiber diameter of 5 µm to 25 µm. A total of 0.02 g of the penetrating agent and the wetting agent is added to 20 ml of a 1/1 mixture of hexane/water, and the penetrating agent and the wetting agent are The nonwoven fabric according to any one of claims 1 to 10, wherein the added mixed liquid is stirred and the oil phase and the water phase are separated after 1 minute. The nonwoven fabric according to any one of claims 1 to 11 , which is a spunbond nonwoven fabric. A covering sheet comprising the nonwoven fabric according to any one of claims 1 to 12 . A laminate comprising the nonwoven fabric according to any one of claims 1 to 12 . A cover sheet comprising the laminate of claim 14 . providing a nonwoven comprising fibers of a thermoplastic polymer;
a step of adhering a penetrant containing at least one of a sulfonate and a sulfate salt and a wetting agent to the nonwoven fabric;
has
Ratio of the surface water vapor adsorption area in the water vapor adsorption test obtained by the BET formula of the water vapor adsorption isotherm to the surface nitrogen adsorption area in the nitrogen adsorption test obtained from the BET formula of the nitrogen adsorption isotherm (surface water vapor adsorption area/surface nitrogen adsorption area) is 2.0 to 5.8,
the wetting agent
a polyhydric alcohol fatty acid ester consisting of an ester of glycerin and a fatty acid having 10 to 20 carbon atoms;
an alkylene oxide adduct of a polyhydric alcohol fatty acid ester, which is an ester of glycerin and a fatty acid having 10 to 20 carbon atoms, wherein the number of moles of ethylene oxide added is 5 to 20;
A method of manufacturing a nonwoven fabric , comprising :