JP6715074B2 - Meltblown nonwovens, nonwoven laminates, medical clothing and drapes - Google Patents

Description

The present invention relates to a meltblown nonwoven fabric, a nonwoven fabric laminate, a medical garment and a drape.

The non-woven fabric using the propylene polymer has good spinnability and can easily obtain fine fibers, and is excellent in balance of strength, flexibility, and barrier properties, as compared with the non-woven fabric using the ethylene polymer. Nonwoven fabrics using propylene-based polymers have the above-mentioned properties and are therefore widely used as medical materials, hygiene materials, absorbent articles, packaging materials for various objects, carrying materials, and backing materials.

In particular, long-fiber non-woven fabrics containing a propylene-based polymer obtained by the spunbond method or meltblown method are excellent in lightness, uniformity, strength, flexibility, and comprehensive performance of barrier properties, and thus are medical materials. (For example, it is used for surgical gowns, drapes, masks, sheets, gauze, etc.).

Here, in order to prevent infection, medical materials need to be sterilized before being used. Sterilization methods include electron beam sterilization, gamma ray sterilization, gas sterilization, steam sterilization and the like. Since gamma rays use a radioactive cobalt ray source and gas sterilization mainly uses ethylene oxide gas, there are handling problems. Further, steam sterilization has a problem of sterilization reliability. Therefore, electron beam sterilization is generally ideal as a method capable of performing safe and reliable sterilization in a short time.
However, when polypropylene non-woven fabric is subjected to electron beam sterilization or gamma ray sterilization, the strength tends to decrease in proportion to the irradiation intensity, and at the same time, the barrier property against blood and the like tends to decrease, so the gas sterilization method is adopted. Is the current situation.

As a method for improving such a defect, attempts have been made to impart radiation resistance by adding an additive to a propylene-based polymer. For example, 3,5-di-t-butyl-4- Investigation of hydroxybenzoic acid A nonwoven fabric containing an aliphatic ester has been proposed (see, for example, Patent Document 1).

Further, as a non-woven fabric having good stretchability and good feel, which is suitable for sanitary materials, a propylene-based elastomer containing a unit derived from α-olefin, a propylene-based thermoplastic polymer having specific physical properties, a thermoplastic resin, a hydrocarbon resin A non-woven fabric made from a composition comprising a texture improver, a texture improver, and a slip aid has been proposed (see, for example, Patent Document 2).
Further, from the viewpoint of the barrier property described above, it is the current situation that the air permeability is suppressed and the water pressure resistance is high.

Japanese Patent No. 2633936 Japanese Patent Publication No. 2015-516858

The strength of the non-woven fabric obtained by the technique described in Patent Document 1 after irradiation with radiation is less than that in the case where the long-chain aliphatic ester compound of 3,5-di-t-butyl-4-hydroxybenzoic acid is not contained. It is suppressed.
However, under the present circumstances, when the obtained non-woven fabric is used for medical purposes, for example, the reduction in strength after irradiation with radiation is not sufficiently suppressed to be practically satisfactory.
The non-woven fabric described in Patent Document 2 has improved stretchability and a soft feel, but no consideration is given to suppression of reduction in strength after irradiation with radiation.

The subject of the present invention is that radiation sterilization treatment by electron beam or the like is possible, strength reduction due to radiation sterilization treatment is suppressed, elongation after radiation sterilization treatment is good, and air permeability is kept low melt blown nonwoven fabric, To provide a nonwoven fabric laminate using a meltblown nonwoven fabric, in which strength reduction due to radiation sterilization treatment is suppressed, high water pressure resistance is suppressed, and water pressure resistance reduction due to radiation sterilization treatment is suppressed, and medical clothing and drape using the same. is there.
Another object of the present invention is to provide a meltblown nonwoven fabric which, when used as a member of a nonwoven fabric laminate, has excellent adhesive strength between layers and also excellent strength of the nonwoven fabric laminate.

Means for solving the above problems include the following embodiments.
<1> A meltblown nonwoven fabric made of fibers composed of a propylene-based polymer composition (A) containing a propylene/α-olefin copolymer, a propylene homopolymer, and a propylene-based wax.
<2> The propylene-based polymer composition (A) is 20 parts by mass to 75 parts by mass of the propylene/α-olefin copolymer, relative to 100 parts by mass of the propylene-based polymer composition (A). The melt blown nonwoven fabric according to <1>, containing 5 parts by mass to 30 parts by mass of the propylene homopolymer and 20 parts by mass to 50 parts by mass of the propylene wax.

<3> The melt blown nonwoven fabric according to <1> or <2>, wherein the propylene/α-olefin copolymer has a heat of fusion measured by a differential scanning calorimeter (DSC) of less than 80 J/g.
<4> The melt blown nonwoven fabric according to any one of <1> to <3>, wherein the propylene wax has a weight average molecular weight of 400 to 30,000.

<5> A propylene-based polymer composition (B) different from the propylene-based polymer composition (A) on at least one surface of the meltblown nonwoven fabric according to any one of <1> to <4>. A non-woven fabric laminate in which spun-bonded non-woven fabrics made of fibers are laminated.
<6> A continuous long-fiber nonwoven fabric made of fibers composed of an ethylene-based polymer composition (C) is laminated on at least one surface of the melt-blown nonwoven fabric according to any one of <1> to <4>. A non-woven fabric laminate obtained by the process.
<7> A propylene-based polymer composition (B) different from the propylene-based polymer composition (A) on one surface of the meltblown nonwoven fabric according to any one of <1> to <4>. A non-woven fabric laminate in which a spunbonded non-woven fabric composed of the constituent fibers is laminated, and a continuous long-fiber non-woven fabric composed of the fibers composed of the ethylene polymer composition (C) is laminated on the other surface.

<8> The non-woven fabric laminate according to <6> or <7>, in which the continuous long-fiber non-woven fabric made of fibers composed of the ethylene polymer composition (C) is a melt blown non-woven fabric.
<9> The ethylene polymer composition (C) has a melt flow rate (MFR) of 10 g/10 min to 250 g/10 min ethylene polymer (c-1) and a weight average molecular weight (Mw). 400-15000 ethylene-based polymer wax (c-2), and the content of the ethylene-based polymer (c-1) with respect to the ethylene-based polymer wax (c-2) is a mass ratio [(c -1)/(c-2)] is the range of 90/10 to 10/90, and the nonwoven fabric laminate according to any one of <6> to <8>.
<10> the propylene-based polymer composition (B) is a propylene-based polymer (b-1) with respect to 100 parts by mass of ethylene heavy density of 0.93g ^/ cm ³ ~0.98g ^/ cm 3 The non-woven fabric laminate according to <5>, <7>, <8>, or <9>, which is a polymer composition containing 1 part by mass to 10 parts by mass of the combined product (b-2).

<11> A spunbonded nonwoven fabric composed of fibers composed of the propylene-based polymer composition (B) has a flow rate of 125 Pa under a pressure difference of 125 Pa measured by a Frazier air permeability meter according to JIS L 1096 (2010). The nonwoven fabric laminate according to <10>, which has a measured air permeability of 500 cm ³ /cm ² /s or less.

<12> A medical garment including the melt blown nonwoven fabric according to any one of <1> to <4> or the nonwoven fabric laminate according to any one of <5> to <11>.
<13> A drape including the melt blown nonwoven fabric according to any one of <1> to <4>, or the nonwoven fabric laminate according to any one of <5> to <11>.

According to the present invention, a radiation sterilization treatment using an electron beam or the like is possible, strength reduction due to radiation sterilization treatment is suppressed, and a melt blown nonwoven fabric whose air permeability is suppressed to be low, strength reduction due to radiation sterilization treatment is used. It is possible to provide a non-woven fabric laminate having high water pressure resistance, medical clothing and drapes using the same.
According to the present invention, it is possible to provide a meltblown non-woven fabric which, when used as one member of a non-woven fabric laminate, has excellent adhesive strength between layers and also excellent strength of the non-woven fabric laminate.

Hereinafter, modes for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In the following embodiments, the constituent elements (including element steps, etc.) are not essential unless otherwise specified, unless otherwise apparent in principle. The same applies to the numerical values and the range thereof, and does not limit the present invention.

In the present specification, the term “process” is included in this term as long as the purpose of the process is achieved not only as an independent process but also when it cannot be clearly distinguished from other processes.
In the present specification, the numerical range indicated by using "to" indicates a range including the numerical values before and after "to" as the minimum value and the maximum value, respectively.
In the present specification, the content of each component in the composition is the sum of the substances of the plurality of types present in the composition, unless a plurality of types of substances corresponding to the components are present in the composition. Means quantity.

<Melt blown non-woven fabric>
The meltblown nonwoven fabric of the present embodiment is a meltblown nonwoven fabric composed of fibers composed of a propylene-based polymer composition (A) containing a propylene/α-olefin copolymer, a propylene homopolymer, and a propylene-based wax. is there.

[Propylene-based polymer composition (A)]
The meltblown nonwoven fabric of the present embodiment contains a propylene/α-olefin copolymer having good stretchability and a propylene homopolymer having a relatively high melting point, and further, a propylene polymer composition containing a propylene wax. The fiber is composed of the product (A) (hereinafter sometimes referred to as the composition (A)).
By including a copolymer having excellent stretchability, a propylene homopolymer having a relatively high melting point, and a propylene wax capable of controlling the physical properties of the molten fiber at the time of melt blowing, the fiber constituting the nonwoven fabric becomes thinner In addition, the flexibility is improved, and the reduction in strength due to sterilization treatment such as irradiation is suppressed. Furthermore, the elongation of the nonwoven fabric after the radiation sterilization treatment is good.
The fact that the above components are contained in the composition (A) constituting the meltblown nonwoven fabric of the present embodiment can be appropriately confirmed by a known method.
The good elongation of the melt-blown nonwoven fabric of the present embodiment after the radiation sterilization treatment means that the nonwoven fabric has an elongation, specifically, an elongation index described below of 30% or more.

(Propylene/α-olefin copolymer)
The composition (A) used in the present embodiment includes a polymer (a- in the present embodiment, which contains a propylene/α-olefin copolymer (hereinafter, may be referred to as a polymer (a-1)). 1) is a copolymer containing a constitutional unit derived from propylene and one or more constitutional units derived from α-olefin, and may further include other constitutional units as necessary.

The propylene/α-olefin copolymer used in the present embodiment is a structural unit derived from propylene, and a structural unit derived from at least one α-olefin selected from ethylene and α-olefins having 4 to 20 carbon atoms. A random copolymer containing and is preferable from the viewpoint of maintaining good elongation after irradiation with radiation.

As the constitutional unit copolymerizable with propylene, a constitutional unit derived from ethylene; 1-butene, 1-hexene, 4methyl-1-pentene, 1-octene, 4-methyl-1-pentene or the like having 4 or more carbon atoms. The structural unit derived from the α-olefin selected from the α-olefins and the like. Of these, a structural unit derived from ethylene and a structural unit derived from an α-olefin selected from α-olefins having 4 to 8 carbon atoms are preferable.
The constitutional unit derived from the α-olefin contained in the polymer (a-1) may be only one type, or may be two or more types.
Specific preferred examples of the polymer (a-1) include a propylene/1-butene random copolymer, a propylene/ethylene random copolymer, and a propylene/ethylene/1-butene random copolymer.

In the formula, ΔH is the heat of fusion (J/g) obtained from the heat of fusion curve derived from the melting of the main component of the α-olefin copolymer containing ethylene and propylene, and ΔH0 is the heat of fusion of complete crystals of the main component. (J/g).
The heat of fusion measured by DSC of the polymer (a-1) is less than 80 J/g, which suppresses reduction in strength due to sterilization treatment such as radiation irradiation, elongation after radiation sterilization treatment, and non-woven fabric laminate. It is preferable from the viewpoint of peeling strength when laminated with other non-woven fabric.

The content of the propylene/α-olefin copolymer [copolymer (a-1)] with respect to 100 parts by mass of the composition (A) in the present embodiment is the strength reduction suppression by the sterilization treatment such as radiation irradiation, the radiation sterilization treatment. From the viewpoint that the subsequent elongation and the peel strength when laminated with other non-woven fabric are good, it is preferably 20 parts by mass to 75 parts by mass, and is preferably 20 parts by mass to 49 parts by mass. It is more preferably 30 parts by mass to 45 parts by mass.

(Propylene homopolymer)
The propylene homopolymer used in the present embodiment (hereinafter sometimes referred to as polymer (a-2)) is not particularly limited as long as it is a polymer containing a structural unit derived from propylene.

The melting point (Tm) of the propylene-based polymer (a-2) is not particularly limited, but is preferably in the range of 125°C or higher, more preferably 140°C or higher, and preferably 155°C or higher. It is more preferable that the temperature is in the range of 157°C to 165°C.
By containing the propylene homopolymer having a relatively high melting point as described above in the composition (A), the physical properties of the melt-blown nonwoven fabric to be obtained are further improved, and further applied when desired when forming a nonwoven fabric laminate. It also has an advantage that it is less likely to be affected by heat deterioration in the heat embossing process.

The melt flow rate (MFR ₂₃₀ : ASTM D-1238, ₂₃₀ ° C., load 2160 g) of the propylene homopolymer (a-2) is not particularly limited as long as the propylene polymer (c) can be melt-spun. From the viewpoint of obtaining a melt-blown nonwoven fabric having a small fiber diameter and high barrier properties, it is preferably 10 g/10 minutes to 4000 g/10 minutes, more preferably 50 g/10 minutes to 3000 g/10 minutes, further preferably 100 g/10 minutes to 2000 g/ It is in the range of 10 minutes. Only one kind of the polymer (a-2) may be used in the composition (A), or two or more kinds thereof having different melting points, molecular weights, crystal structures and the like may be used.

Further, the ratio (Mw/Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the propylene homopolymer (a-2) according to the present invention is preferably 1.5 to 5.0. .. The range of 1.5 to 4.5 is more preferable from the viewpoint that fibers having good spinnability and particularly excellent fiber strength can be obtained. Mw and Mn of the propylene-based polymer (c) according to the present invention are values obtained by GPC measurement, and are values measured under the following conditions. In addition, Mw and Mn are calculated|required based on the following conversion method, creating a calibration curve using a commercially available monodisperse standard polystyrene.
Equipment: Tosoh HLC8321 GPC/HT
Solvent: o-dichlorobenzene Column: TSKgel GMH6-HT x 2, TSKgel GMH6-HTL column x 2 (all manufactured by Tosoh Corporation)
Flow rate: 1.0 ml/min Sample: 0.10 mg/mL o-dichlorobenzene solution Temperature: 140°C
Molecular weight conversion: PP conversion/general-purpose calibration method The coefficient of the Mark-Houwink viscosity formula shown below was used for the calculation of general-purpose calibration.
Polystyrene (PS) coefficient: KPS=1.38×10 ⁻⁴ , aPS=0.70
Coefficient of polypropylene (PP): KPP=2.42×10 ⁻⁴ , aPP=0.707

The content of the propylene homopolymer (a-2) relative to 100 parts by mass of the composition (A) is preferably in the range of 5 parts by mass to 30 parts by mass, and preferably in the range of 10 parts by mass to 30 parts by mass. Is more preferable, and the range of 16 to 30 parts by weight is further preferable.

(Propylene wax)
The composition (A) contains a propylene-based wax (hereinafter sometimes referred to as wax (a-3)). When the composition (A) contains a propylene-based wax, it becomes easy to adjust the viscosity of the composition (A) in a molten state to a preferable range when forming fibers using the composition (A), and thus the composition (A The fibers produced according to () can have a finer fiber diameter.
By confirming that the fiber formed by the composition (A) contains the propylene-based wax, it can be confirmed that the composition (A) forming the fiber contains the wax.
In addition, the composition (A) contains a propylene-based wax, and when formed into a meltblown nonwoven fabric from the fibers composed of the composition (A), a nonwoven fabric having a fine fiber diameter, good texture and low air permeability is obtained. can get. When the composition (A) contains a propylene-based wax, in addition to the above effect of reducing the molecular weight and viscosity of the composition (A) as a whole, the reason for which the reason is not clear is to prevent shots at the time of molten fiber discharge and to prevent formation. It is considered that the effect of improving is exhibited.
Shot is a method of forming fibers from a molten resin such as a melt blown method, in which the molten resin does not become a fiber shape in which the diameter is reduced to a fiber shape, but becomes a granular lump, and a non-fibrous resin that remains as particles. It is a particle. If shots are present in the fibers that make up the nonwoven fabric, the nonwoven fabric may become non-uniform, resulting in reduced feel and strength and increased air permeability. Furthermore, when a nonwoven fabric laminate containing the nonwoven fabric of the present embodiment is used, the water pressure resistance of the nonwoven fabric laminate may decrease.

The wax (a-3) is preferable because it has an affinity with the composition (A). In the present embodiment, the fiber-forming composition (A) contains the propylene structural unit-containing copolymer (a-1) and the propylene homopolymer (a-2). By including a-3), it becomes easier to reduce the average fiber diameter of the fibers constituting the meltblown nonwoven fabric to be obtained, and it is easier to obtain a flexible nonwoven fabric of uniform quality.

The propylene-based wax is a propylene-based polymer having a relatively low molecular weight, that is, a wax-like propylene-based polymer. The propylene-based wax may be one produced by polymerization of a commonly used low-molecular weight polymer or monomer, or one obtained by heating and degrading a propylene-based polymer having a higher molecular weight to reduce the molecular weight. Well, the method for producing the propylene wax is not particularly limited.

The weight average molecular weight (Mw) of the propylene wax (a-3) that can be used in this embodiment is preferably 400 to 30,000. The Mw of the propylene polymer wax (a-3) is preferably 400 to 25,000, more preferably 1000 to 10,000.
The molecular weight and the molecular weight distribution of the wax were measured by the GPC method.
The measurement was carried out under the following conditions using a commercially available monodisperse standard polystyrene as a standard.
Device: Gel Permeation Chromatograph Alliance GPC2000 type (Waters)
Solvent: o-dichlorobenzene Column: TSK gel column (manufactured by Tosoh Corporation) x 4
Flow rate: 1.0 ml/min Sample: 0.3% o-dichlorobenzene solution Temperature: 140°C
When the Mw of the propylene-based wax is within the above range, it becomes easier to make the fibers constituting the non-woven fabric thinner, and it is possible to further suppress the occurrence of shots when the molten fibers are discharged.

The propylene wax preferably has a softening point of higher than 90° C. measured according to JIS K2207 (1996). The softening point is more preferably 100° C. or higher.
When the softening point is 90° C. or higher, heat resistance stability during heat treatment or use can be further improved, and as a result, heat resistance of the nonwoven fabric can be further improved.
The upper limit of the softening point is not particularly limited, but the upper limit is, for example, 168°C.

Examples of the propylene wax include a homopolymer of propylene, a copolymer of propylene and a C 2 or α-olefin having 4 to 20 carbons, and the like.

A commercially available product may be used as the propylene-based wax.
The composition (A) may contain only one type of propylene wax (a-3), or may contain two or more types.
The content of the propylene wax (a-3) with respect to 100 parts by mass of the propylene polymer composition (A) is preferably in the range of 20% by mass to 50% by mass, and in the range of 30% by mass to 50% by mass. Are more preferable, and the range of 35 mass%-50 mass% is still more preferable.
When the content of the propylene-based wax in the composition (A) is in the above range, the spinnability becomes better and the fiber diameter can be made thinner.

The total content of the propylene homopolymer (a-2) and the propylene wax (a-3) in the composition (A) is the composition (A) from the viewpoint of the effect of spinnability and fineness of the fiber diameter. It is preferably more than 50% by mass based on the total amount.

<Physical properties of meltblown nonwoven fabric>
The average fiber diameter of the fibers forming the meltblown nonwoven fabric is preferably in the range of 0.1 μm to 10 μm, more preferably in the range of 0.5 μm to 8 μm, still more preferably in the range of 1 μm to 5 μm, and particularly preferably in the range of 1 μm to 4 μm. When the average fiber diameter is within the above range, the melt-blown nonwoven fabric obtained has good uniformity and excellent nonwoven fabric barrier properties. Further, it is preferable that the average fiber diameter of the fibers forming the meltblown nonwoven fabric is within the above range, because the strength, barrier property and uniformity after electron beam irradiation are excellent.

Basis weight of the meltblown nonwoven fabric is preferably in a range of from ^{1g / m 2 ~30g / m 2} , more preferably in the range of ^{5g / m 2 ~30g / m 2} , further preferably in the range of ^{10g / m 2 ~25g / m 2} . When the basis weight is within the above range, the flexibility and barrier properties are excellent. Further, when the basis weight of the meltblown nonwoven fabric is within the above range, the strength, barrier property and uniformity after electron beam irradiation are excellent, which is preferable.
On the other hand, the melt-blown nonwoven fabric does not require a high barrier property from the viewpoint of use, and is mainly used for applications requiring high air permeability, flexibility, and lightness, for example, when used for sanitary materials, etc. range, preferably ^{0.5g / m 2 ~5g / m 2} , more preferably in the range of ^{0.5g / m 2 ~3g / m 2} .

From the viewpoint that the spinnability and the fiber diameter can be made smaller, the weight average molecular weight (Mw) of the composition (A) is preferably 30,000 to 90,000, more preferably 40,000 to 80,000. It is preferably 40,000 to 75,000, and particularly preferably.
Spinnability, from the viewpoint that the fiber diameter can be made thinner, and suppression of strength reduction due to sterilization treatment such as irradiation, elongation after radiation sterilization treatment, and peel strength when laminated with other nonwoven fabric in a nonwoven fabric laminate. From the viewpoint, the range of the propylene content of the composition (A) is preferably 90% by mass to 98% by mass, and more preferably 92% by mass to 96% by mass.

The content (mass %) of propylene or ethylene in the composition (A) can be determined by conversion from the mol% measured by 13 C-NMR, as described below.
The measurement conditions are as described below.

~Measurement condition~
Measuring equipment: Nuclear magnetic resonance equipment (Avance III cryo-500 type manufactured by Bruker BioSpin)
Observation nucleus: 13C (125MHz)
Sequence: Single pulse Proton decoupling Pulse width: 5.00 μsec (45° pulse)
Repeating time: 5.5 seconds Accumulation number: 128 times Solvent: Orthodichlorobenzene/deuterated benzene (volume ratio: 80/20) mixed solvent Sample concentration: 60 mg/0.6 mL
Measurement temperature: 120°C
Reference value of chemical shift: mmmm (CH3) 21.59 ppm

In order to obtain a meltblown nonwoven fabric having a small fiber diameter and a high barrier property while suppressing a decrease in molecular weight after electron beam irradiation, the composition (A) preferably contains the following stabilizer.

That is, in the present embodiment, the fibers forming the meltblown nonwoven fabric contain the copolymer (a-1) and the polymer (a-2) that are propylene-based polymers, so that the molecular weight after electron beam irradiation is reduced. The composition (A) preferably contains the following stabilizer as an additive for the purpose of suppressing the accompanying decrease in strength and the decrease in barrier property.
Examples of the stabilizer that can be used in the composition (A) include at least one stabilizer selected from the group consisting of an organic phosphorus compound, a hindered amine compound, and a phenol compound, and among them, an organic phosphorus compound is included. Is preferred.
The stabilizer may include only one kind or two or more kinds. Among them, it is more preferable to include two or more different stabilizers. Preferable examples of the combination of two or more stabilizers include a combination of an organic phosphorus compound and a hindered amine compound, and a combination of an organic phosphorus compound and a phenol compound. It is particularly preferable that the stabilizer includes an organic phosphorus compound, a hindered amine compound, and a phenol compound.
Hereinafter, the stabilizer that can be used in this embodiment will be described in detail.

(I) Organophosphorus compound As the stabilizer in this embodiment, an organophosphorus compound that is a known compound as an antioxidant stabilizer can be used.
Specific examples of the organic phosphorus compound include trioctyl phosphite, trilauryl phosphite, tridecyl phosphite, octyl-diphenyl phosphite, and tris(2,4-di-tert-butylphenyl)phosphite. Fight, triphenyl phosphite, tris(butoxyethyl)phosphite, tris(nonylphenyl)phosphite, distearyl pentaerythritol diphosphite, tetra(tridecyl)-1,1,3-tris(2-methyl-5- tert-Butyl-4-hydroxyphenyl)butanediphosphite, tetra(C12-C15 mixed alkyl)-4,4′-isopropylidenediphenyldiphosphite, tetra(tridecyl)-4,4′-butylidenebis(3-methyl) -6-tert-Butylphenol) diphosphite, tris(3,5-di-tert-butyl-4-hydroxyphenyl)phosphite, tris(mono-dimixed nonylphenyl)phosphite, hydrogenated-4,4'-isopropyi Ridenediphenol polyphosphite, bis(octylphenyl).bis[4,4'-butylidenebis(3-methyl-6-tert-butylphenol)].1,6-hexanediol diphosphite, phenyl 4,4' -Isopropylidene diphenol pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol Diphosphite, tris[4,4'-isopropylidene bis(2-tert-butylphenol)]phosphite, phenyl diisodecyl phosphite, di(nonylphenyl)pentaerythritol diphosphite), tris(1,3-di -Stearoyloxyisopropyl)phosphite, 4,4'-isopropylidene bis(2-tert-butylphenol).di(nonylphenyl)phosphite, 9,10-di-hydro-9-oxa-10-phosphaphenance Examples thereof include len-10-oxide, tetrakis(2,4-di-tert-butylphenyl)-4,4′-biphenylene diphosphonite and the like.
Among them, tris(2,4-di-tert-butylphenyl)phosphite, tris(mono/di mixed nonylphenyl)phosphite and the like are preferably used.
When the composition (A) in the present embodiment uses an organophosphorus compound as a stabilizer, it may be used alone or in combination of two or more.
The content of the organophosphorus compound is 0.001 part by mass to 3 parts based on 100 parts by mass of the total content of the copolymer (a-1) and the polymer (a-2) in the composition (A). The amount is preferably parts by mass, and more preferably 0.001 part by mass to 1 part by mass.

(II) Hindered amine-based compound As the stabilizer in this embodiment, a hindered amine-based compound that is a known compound as a light stabilizer can be used. Any hindered amine compound known as a light stabilizer can be used without particular limitation. Of these, hindered amine compounds having a structure in which all the hydrogens bonded to the carbons at the 2nd and 6th positions of piperidine are replaced with methyl groups are preferred examples.
Specific examples of the hindered amine compound include bis(2,2,6,6-tetramethyl-4-piperidine) sebacate and bis(2,2,6,6-tetramethyl-4-decanedioate). Piperidinyl), 2,4-dichloro-6-(1,1,3,3-tetramethylbutylamino)-1,3,5-triazine.N,N'-bis(2,2,6,6-tetra Methyl-4-piperidyl)hexamethylenediamine polycondensate, dimethyl-1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate succinate, poly[[6- (1,1,3,3-Tetramethylbutyl)imino-1,3,5-triazine-2-4-diyl][(2,2,6,6-tetramethyl-4-piperidyl)imino]hexamethylene [(2,2,6,6-Tetramethyl-4-piperidyl)imino]], Tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxy Rate, 2,2,6,6-tetramethyl-4-piperidyl benzoate, bis-(1,2,2,6,6-pentamethyl-4-piperidyl)-2-(3,5-di-t-butyl -4-hydroxybenzyl)-2-n-butylmalonate, bis-(N-methyl-2,2,6,6-tetramethyl-4-piperidyl) sebacate, 1,1'-(1,2-ethanediyl) ) Bis(3,3,5,5-tetramethylpiperazinone), (mixed 2,2,6,6-tetramethyl-4-piperidyl/tridecyl)-1,2,3,4-butanetetracarboxy Rate, (mixed 1,2,2,6,6-pentamethyl-4-piperidyl/tridecyl)-1,2,3,4-butane tetracarboxylate, mixed {2,2,6,6-tetramethyl -4-piperidyl/β,β,β′,β′-tetramethyl-3,9-[2,4,8,10-tetraoxaspiro(5,5)undecane]diethyl}-1,2,3 4-butanetetracarboxylate, mixed {1,2,2,6,6-pentamethyl-4-piperidyl/β,β,β′,β′-tetramethyl-3,9-[2,4,8, 10-Tetraoxaspiro(5,5)undecane]diethyl}-1,2,3,4-butanetetracarboxylate, N,N′-bis(3-aminopropyl)ethylenediamine-2-4-bis[N- Butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)a Mino]-6-chloro-1,3,5-triazine condensate, poly[[6-N-morpholyl-1,3,5-triazine-2-4-diyl][(2,2,6,6- Tetramethyl-4-piperidyl)imino]hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl)imino]], N,N'-bis(2,2,6,6-tetramethyl- Condensation product of 4-piperidyl)hexamethylenediamine and 1,2-dibromoethane, [N-(2,2,6,6-tetramethyl-4-piperidyl)-2-methyl-2-(2,2,2 6,6-tetramethyl-4-piperidyl)imino]propionamide and the like.
Among these, decanedioate bis(2,2,6,6-tetramethyl-4-piperidinyl), 2,4-dichloro-6-(1,1,3,3-tetramethylbutylamino)-1 , 3,5-triazine.N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine polycondensate and the like are preferable.
When the hindered amine compound is used as the stabilizer in the composition (A) in the present embodiment, one kind may be used alone, or two or more kinds may be used in combination.
The amount of the hindered amine compound used is 0.001 part by mass to 3 parts by mass based on 100 parts by mass of the total content of the copolymer (a-1) and the polymer (a-2) in the composition (A). Parts by weight, and more preferably 0.001 parts by weight to 1 part by weight.

(III) Phenolic compound As the stabilizer in the present embodiment, a phenolic compound which is a known compound as an antioxidant stabilizer can be used.
Specific examples of the phenolic compound include 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)-butane and 4,4′-butylidene-bis(3-). Rehindered type such as methyl-6-t-butylphenol), 3,9-bis[1,1-dimethyl-2-{β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy } Ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane and other semi-hindered types, tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, n- Octadecyl-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate, tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxy-phenyl] ) Propionate]-Hindered types such as methane.
Among these, less hindered types such as 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)-butane are more effective in suppressing fiber deterioration due to electron beam irradiation. It is preferably used because it is good.
When the composition (A) in the present embodiment uses a phenolic compound as a stabilizer, it may be used alone or in combination of two or more.
The usage-amount of the said phenolic compound is 0.001 mass part-3 mass with respect to 100 mass parts of total contents of the copolymer (a-1) and polymer (a-2) in a composition (A). Parts by weight, and more preferably 0.001 to 0.5 parts by weight.

When the composition (A) in the present embodiment contains the stabilizer described above, tris(2,4-di-tert-butylphenyl)phosphite is used as the organic phosphorus compound (I). (II) Hindered amine compounds include decanedioate bis(2,2,6,6-tetramethyl-4-piperidinyl) and 2,4-dichloro-6-(1,1,3,3-tetramethylbutyl). Amino)-1,3,5-triazine.N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine polycondensate is used as (III) phenolic compound. It is preferable to use 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)-butane. Above all, it is more preferable to use a plurality of different stabilizers in combination. For example, an organophosphorus compound of tris(2,4-di-tert-butylphenyl)phosphite, bis(2,2,6,6-tetramethyl-4-piperidinyl) decanedioate, and 2,4-dichloro -6-(1,1,3,3-Tetramethylbutylamino)-1,3,5-triazine.N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylene It is further preferable that at least one hindered amine compound selected from a diamine polycondensate and a phenol compound that is 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)-butane are included. preferable.
The total amount of these stabilizers used is 0.01 parts by mass to 100 parts by mass of the total content of the copolymer (a-1) and the polymer (a-2) in the composition (A). The amount is preferably 10 parts by mass, more preferably 0.03 parts by mass to 2 parts by mass. Since the stabilizer may deteriorate due to degradation at high temperature, when supplementing the amount of deterioration, the use amount may be increased from the preferable use amount described above.

(Other additives)
The composition (A) may further contain a known additive in addition to the above-mentioned stabilizer as long as the effects of the present embodiment are not impaired.
For example, in the case where coloring of fibers due to electron beam irradiation is concerned, an organic or inorganic coloring pigment can be contained in the composition (A). When using a color pigment, the content of the color pigment should be in a range not exceeding the above-described preferable content of the stabilizer in order to prevent adverse effects such as deterioration in function due to the stabilizer being adsorbed by the color pigment component. Is preferred.

Examples of other additives include sulfur-based and phosphite-based antioxidants; benzoate-based, benzophenone-based, triazole-based, nickel-based light stabilizers; other metal deactivators and antistatic agents , Lubricants, release agents, organic pigments, inorganic pigments, fillers, peroxides, foaming agents, flame retardants, nucleating agents, propylene/ethylene copolymer rubber, ethylene/butene copolymer rubber, etc. Ingredients and the like can be contained depending on the purpose.

The meltblown nonwoven fabric can be produced using the propylene-based polymer composition (A) described above by a known method for producing a meltblown nonwoven fabric.
Specifically, preferably, the composition (A) containing a stabilizer is melt-kneaded with an extruder or the like, the above-mentioned melt-kneaded product is discharged from a spinneret having a spinning nozzle, and sprayed from around the spinneret. It can be carried out by a melt blown method in which a web is produced by blowing off with a high-speed and high-temperature air flow to deposit as self-adhesive microfibers on a collecting belt to a predetermined thickness. At this time, the web of deposited microfibers can be subsequently entangled, if desired.

Examples of the method of entanglement treatment of the deposited web include a method of hot embossing treatment using an embossing roll; a method of fusion by ultrasonic waves; a method of entanglement of fibers using a water jet; a method of fusion by hot air through. Various methods such as a method of wearing; a method of using a needle punch and the like can be mentioned, and these methods can be appropriately used.

The melt blown nonwoven fabric of the present embodiment has an air permeability of 200 cm ³ /cm ² /measured by a Frazier air permeability meter according to JIS L 1096 (2010) at a flow rate of 125 Pa with a basis weight of 20 g/m ² . s or less. It is preferably 150 cm ³ /cm ² /s or less, and preferably 80 cm ³ /cm ² /s or less.
When the air permeability of the meltblown nonwoven fabric is within the above range, appropriate air permeability and barrier property can be obtained. Moreover, the obtained meltblown nonwoven fabric has excellent strength. When the air permeability is within such a range, it can be suitably used especially for medical materials and the like.

<Nonwoven fabric laminate>
The nonwoven fabric laminate of the present embodiment is a laminate containing the meltblown nonwoven fabric of the present embodiment described above.
The nonwoven fabric laminate according to the present embodiment, for example, for the purpose of imparting other functions (for example, strength, uniformity, barrier property, adjusting the balance of breathability, weight reduction, etc.), at least one surface of the meltblown nonwoven fabric, It can be formed by laminating a non-woven fabric different from the above-mentioned melt blown non-woven fabric.
Non-woven fabrics that can be laminated include short fiber non-woven fabrics and long fiber non-woven fabrics. Examples of the fiber material of these non-woven fabrics include cellulosic fibers such as cotton, cupra and rayon; polyolefin fibers; polyamide fibers; polyester fibers. Further, there may be mentioned meltblown nonwoven fabrics different from the meltblown nonwoven fabrics of the present embodiment described above; spunbonded nonwoven fabrics; wet nonwoven fabrics; dry nonwoven fabrics; dry pulp nonwoven fabrics; flash spun nonwoven fabrics;
These non-woven fabrics can be laminated by selecting one kind or two or more kinds. For example, another nonwoven fabric may be laminated on at least one surface of the meltblown nonwoven fabric of the present embodiment, or nonwoven fabrics may be laminated on both surfaces. Further, three or more layers of nonwoven fabric may be laminated on the meltblown nonwoven fabric of the present embodiment to form a laminate containing four or more layers of nonwoven fabric.
In addition, in this specification, a "short fiber" means the fiber whose average fiber length is 200 mm or less. The term "long filament" means "continuous filament" generally used in this technical field, such as Handbook of Nonwoven Fabric (edited by INDA American Nonwoven Fabric Association, Nonwoven Information Co., Ltd., 1996). To do.

<Nonwoven fabric laminate according to the first embodiment>
The nonwoven fabric laminate according to the first embodiment is a propylene-based polymer composition different from the above-described propylene-based polymer composition (A) on at least one surface of the melt-blown nonwoven fabric according to the present embodiment. It is a non-woven fabric laminate in which spun-bonded non-woven fabrics composed of the fibers (B) are laminated.
The propylene-based polymer composition (B) different from the above-mentioned propylene-based polymer composition (A) has 100 parts by mass of the propylene-based polymer (b-1) and a density of 0.93 g/cm ^{3 to} 0. It is preferably a propylene-based polymer composition (B) containing 1 part by mass to 10 parts by mass of an ethylene-based polymer (b-2) of 0.98 g/cm ³ .
The spunbonded nonwoven fabric made of fibers composed of the propylene-based polymer composition (B) used in the nonwoven fabric laminate of the first embodiment is a Frazier air permeability meter according to JIS L 1096 (2010). It is preferable that the air permeability measured under the condition of the flow rate with the pressure difference of 125 Pa is less than or equal to 500 cm ³ /cm ² /s.
The propylene polymer composition (B) (hereinafter sometimes referred to as the composition (B)) may further contain an ethylene polymer wax (b-3).

The spunbonded non-woven fabric made of fibers composed of the propylene-based polymer composition (B) in the non-woven fabric laminate of the first embodiment has the above-mentioned constitution, and thus can be sterilized by an electron beam or the like. Spunbonded non-woven fabric having sufficiently high strength even after radiation sterilization treatment of a wire or the like, and further suppressing deterioration of spinnability due to inclusion of the ethylene polymer (b-2) even when the fiber diameter is reduced. Therefore, it can be suitably used for a nonwoven fabric laminate.
A spunbonded nonwoven fabric made of fibers containing the composition (B) has a small fiber diameter, and a nonwoven fabric laminate containing the spunbonded nonwoven fabric can be particularly suitably applied to medical clothing and drapes.

[Spunbond nonwoven fabric]
The constituent elements of the spunbonded nonwoven fabric used in the nonwoven fabric laminate of the first embodiment will be specifically described below.
The spunbonded nonwoven fabric (hereinafter sometimes referred to as the spunbonded nonwoven fabric (B)) used for the nonwoven fabric laminate of the first embodiment has 100 parts by mass of the propylene-based polymer (b-1) and a density of 0. 93g ^/ cm ³ ~0.98g ^/ cm 3 in which ethylene polymer (b-2) be made of made fibers propylene-based polymer composition comprising one part by weight to 10 parts by weight, the (B) Is preferred.
Further, it is preferable that the air permeability measured by the Frazier air permeability measuring device according to JIS L 1096 (2010) under the condition of the flow rate at the pressure difference of 125 Pa is 500 cm ³ /cm ² /s or less.
The propylene polymer composition (B) may further contain an ethylene polymer wax (b-3).

[Propylene-based polymer composition (B)]
As described above, the propylene-based polymer composition (B), which is a raw material of the spunbonded nonwoven fabric (B), contains 100 parts by weight of the propylene-based polymer (b-1) as the ethylene-based polymer (b-2)1. It is preferably a propylene-based polymer composition containing 10 parts by mass to 10 parts by mass.
The propylene polymer composition (B) may further contain an ethylene polymer wax (b-3).
Hereinafter, each component that can be contained in the composition (B) will be described.

(Propylene polymer (b-1))
The propylene-based polymer (b-1), which is the main component of the propylene-based polymer composition (B) that is the raw material of the spunbonded nonwoven fabric (B) used in the nonwoven fabric laminate of the first embodiment, is It is a polymer mainly composed of propylene such as a homopolymer or a copolymer of propylene and a small amount of α-olefin. The α-olefin copolymerized with propylene may be an α-olefin having 2 or more carbon atoms (excluding 3 carbon atoms), preferably 2, 4 to 8 carbon atoms. Specific examples thereof include α-olefins such as ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 4-methyl-1-pentene. These α-olefins are one kind. Alternatively, two or more kinds may be used. In order to maintain the strength and spinning stability of the nonwoven fabric, the propylene polymer (b-1) is preferably a propylene homopolymer or a propylene/ethylene random copolymer. Furthermore, when heat resistance is important, the propylene-based polymer (b-1) is preferably a propylene homopolymer.
The ethylene content in the propylene/ethylene random copolymer is preferably 0.5 mol% to 10 mol%, more preferably 3 mol% to 8 mol%, and even more preferably 4 mol% to 7 mol%.

The melting point (Tm) of the propylene polymer (b-1) is not particularly limited, but is preferably in the range of 125°C or higher, more preferably 140°C or higher, and preferably 155°C or higher. It is more preferable that the temperature is in the range of 157°C to 165°C.

The melt flow rate (MFR ₂₃₀ : ASTM D-1238, ₂₃₀ ° C., load 2160 g) of the propylene polymer (b-1) is not particularly limited as long as the propylene polymer (b-1) can be melt-spun. However, it is preferably in the range of 1 g/10 minutes to 500 g/10 minutes, more preferably 5 g/10 minutes to 200 g/10 minutes, and further preferably 10 g/10 minutes to 100 g/10 minutes.

The ratio (Mw/Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the propylene-based polymer (b-1) that can be used for the spunbond nonwoven fabric (B) is 1.5 to 5.0. Is preferred. Mw/Mn is more preferably in the range of 1.5 to 4.5 from the viewpoint that fibers having excellent spinnability and particularly excellent fiber strength can be obtained. Mw and Mn can be measured by a known method by the GPC method.

The density of the propylene-based polymer (b-1) is ^preferably in the range of ^{0.895g / cm 3 ~0.915g / cm 3} , more preferably ^{0.900g / cm 3 ~0.915g / cm 3} , 0.905 g/cm ^{3 to} 0.910 g/cm ³ are more preferable.
The density of the polymer in the present specification is a value obtained by measurement according to the density gradient method of JIS K7112.

(Ethylene polymer (b-2))
The ethylene polymer (b-2), which is another component of the propylene polymer composition (B) used in the spunbond nonwoven fabric (B), is a homopolymer of ethylene, or ethylene and a small amount of other α-. It is preferably a copolymer with an olefin. The ethylene polymer (b-2) is specifically ethylene such as high-pressure low-density polyethylene, linear low-density polyethylene (so-called LLDPE), medium-density polyethylene (so-called MDPE), and high-density polyethylene (so-called HDPE). It is preferably at least one selected from the group consisting of polymers mainly composed of

Examples of other α-olefins copolymerized with ethylene include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, Examples thereof include α-olefins having 3 to 20 carbon atoms such as 1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene. The ethylene polymer (b-2) used in the composition (B) may be used alone or in combination of two or more kinds.

Ethylene polymer which may be used in the composition (B) (b-2) is preferably a density in the range of ^{0.93g / cm 3 ~0.98g / cm 3} . When an ethylene polymer having a density within this range is used, deterioration of spinnability is suppressed, and the resulting spunbonded nonwoven fabric (B) has excellent strength. Also, an effect of excellent stability over time can be obtained. Point and the spinning of the deterioration is further suppressed, in that the strength is further improved, the density is preferably in the range of ^{0.940g / cm 3 ~0.980g / cm 3} , 0.940g / cm 3 ~0.975g The range of /cm ³ is more preferable. In particular, 0.950 g / ^cm 3 density polyethylene in the range of ~0.970g / cm ³ (HDPE) is preferred.

The melt flow rate (MFR ₁₉₀ : ASTM D 1238, ₁₉₀ ° C., load 2160 g) of the ethylene polymer (b-2) that can be used in the composition (B) is the same as that of the ethylene polymer (b-2). There is no particular limitation as long as it can be mixed with the coalesced product (b-1) and melt-spun. From the viewpoint of fiber spinnability, fiber diameter, and strength, the melt flow rate of the ethylene polymer (b-2) is preferably in the range of 1 g/10 minutes to 50 g/10 minutes. The range is more preferably 2 g/10 minutes to 25 g/10 minutes, and further preferably 2 g/10 minutes to 10 g/10 minutes.
When the melt flow rate of the ethylene polymer (b-2) is within the above range, the propylene polymer composition (B) has good spinnability, and the spunbonded nonwoven fabric (B) obtained is It has excellent strength. Since such characteristics are obtained, the nonwoven fabric laminate containing the obtained spunbonded nonwoven fabric (B) can be suitably used particularly for medical materials and the like.

As the ethylene-based polymer (b-2), a polymer obtained by various known production methods (for example, a high pressure method, an intermediate pressure method obtained by using a Ziegler catalyst or a metallocene catalyst) can be used. Among these polymers, when an ethylene polymer obtained by polymerization with a metallocene catalyst is used, the propylene polymer composition (B) has better spinnability, and the resulting spunbond nonwoven fabric (B Is preferable in that the strength and the like are improved.
The content of the ethylene polymer (b-2) is preferably 1 part by mass to 10 parts by mass, and preferably 2 parts by mass to 100 parts by mass of the propylene polymer (b-1) described above. 9 parts by mass is more preferable, and 3 parts by mass to 8 parts by mass is further preferable.
The content of the ethylene polymer (b-2) in the propylene polymer composition (B) is 1 part by mass or more based on 100 parts by mass of the propylene polymer (b-1) described above. For example, the strength of the obtained spunbonded nonwoven fabric (B) after radiation sterilization with an electron beam or the like becomes excellent. Further, since durability, for example, the bonding strength of the hot embossed portion (also referred to as a thermocompression bonding portion) is sufficient, when this nonwoven fabric is used as a medical material, it has excellent strength and flexibility. It becomes a thing. On the other hand, when the content of the ethylene polymer (b-2) is 10 parts by mass or less, the propylene polymer composition (B) becomes excellent in spinnability.

(Ethylene polymer wax (b-3))
The propylene-based polymer composition (B), which is a raw material of the spunbonded nonwoven fabric (B), may contain an ethylene-based polymer wax (b-3), if necessary.
When the composition (B) contains the ethylene polymer wax (b-3), the effect of improving the dispersibility of the propylene polymer (b-1) and the ethylene polymer (b-2) is obtained. To be Therefore, the propylene-based polymer composition (B) preferably contains the ethylene-based polymer wax (b-3) from the viewpoint that spinnability is more easily improved.
The ethylene-based polymer wax (b-3) in the first embodiment is a wax-like polymer having a lower molecular weight than the ethylene-based polymer (b-2).

The weight average molecular weight (Mw) of the ethylene polymer wax (b-3) is preferably 15,000 or less. It is more preferably less than 15,000, more preferably less than 10,000, still more preferably less than 6,000, further preferably less than 6,000, particularly preferably less than 5,000, particularly preferably less than 1,500. The range is most preferable. The lower limit of Mw is preferably 400 or more, more preferably 1000 or more.
When the weight average molecular weight (Mw) of the ethylene polymer wax (b-3) is within the above range, the spinnability of the propylene polymer composition (B) is more likely to be improved, and the fiber diameter is It tends to be thin, and moreover it is easier to obtain stability over time.
In addition, when the spunbonded nonwoven fabric (B) is laminated with the meltblown nonwoven fabric of the present embodiment to form a nonwoven fabric laminate, it is preferable because the adhesiveness and strength between layers tend to be excellent.

The weight average molecular weight (Mw) of the ethylene-based polymer wax (b-3) is a value obtained by GPC measurement, and the value measured under the conditions described in the above-mentioned GPC measurement method is adopted. The weight average molecular weight can be determined by preparing a calibration curve using a commercially available monodisperse standard polystyrene and based on the conversion method described above.

The ethylene polymer wax (b-3) has a softening point measured according to JIS K2207 of preferably 90°C to 145°C, more preferably 90°C to 130°C, and more preferably 100°C. It is more preferably 120°C, and most preferably 105°C to 115°C.

The ethylene polymer wax (b-3) may be either a homopolymer of ethylene 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 (b-3), the carbon number of the α-olefin to be copolymerized with ethylene is 3 carbon atoms. To 8 are more preferable, 3 to 4 carbon atoms are still more preferable, and 3 carbon atoms are particularly preferable. When the carbon number of the α-olefin to be copolymerized with ethylene is within the above range, the spinnability becomes better and the properties such as strength of the nonwoven fabric can be further enhanced.
The reason is not clear, but it is considered as follows. In the ethylene polymer wax (b-3), when the carbon number of the α-olefin to be copolymerized with ethylene is in the above range, the propylene polymer (b-1) contains the ethylene polymer wax (b- It is considered that the ethylene polymer (b-2) is easily dispersed through 3). That is, since the ethylene polymer wax (b-3) acts as a compatibilizing agent for the propylene polymer (b-1) and the ethylene polymer (b-2), the propylene polymer composition ( It is considered that the increase in the homogeneity as B) further improves the balance of properties such as spinnability and strength of the nonwoven fabric.
When an ethylene homopolymer is used as the ethylene polymer wax (b-3), it has excellent kneading properties with the ethylene polymer (b-2) and excellent spinnability. The ethylene polymer wax may be used alone or as a mixture of two or more kinds.

The ethylene-based polymer wax (b-3) used in the spunbond nonwoven fabric (B) is produced by polymerizing a commonly used low-molecular weight polymer, or the molecular weight of a high-molecular-weight ethylene polymer is reduced by heating to reduce the molecular weight. It may be produced by any method such as a method of applying and is not particularly limited.
Further, the ethylene polymer wax (b-3) may be purified by a method such as solvent fractionation in which it is fractionated by the difference in solubility in a solvent, or distillation.
When the ethylene polymer wax (b-3) is obtained by a commonly used production method by polymerization of a low molecular weight polymer, various known production methods, for example, Ziegler/Natta catalyst, or JP-A-08-239414. Alternatively, it can be produced by the production method described in WO 2007/114102 or the like in which polymerization is carried out using a metallocene catalyst or the like.

Although the density is not particularly limited ethylene polymer wax ^(b-3), it is preferably ^{0.890g / cm 3 ~0.980g / cm 3} . More preferably 0.910 g / cm ³ or more, and still more preferably 0.920 g / cm ³ or more. Further, it is preferably 0.960 g/cm ³ or less, and more preferably 0.950 g/cm ³ or less. When the ethylene-based polymer wax (b-3) having a density within the above range is used, the propylene-based polymer composition (B) tends to have excellent spinnability. Further, when the spunbonded nonwoven fabric (B) is laminated with the above-described meltblown nonwoven fabric of the present embodiment to form a nonwoven fabric laminate, it is preferable in that adhesiveness between layers and strength are likely to be excellent.

The difference between the density of the propylene polymer (b-1) and the density of the ethylene polymer wax (b-3) is not particularly limited, but is preferably less than 0.35 g/cm ^3. It is particularly preferably less than 0.20 g/cm ³ , and most preferably less than 0.15 g/cm ³ . When the difference in density is in the above range, the spinnability becomes better and the properties such as strength of the nonwoven fabric can be enhanced. The reason is not clear, but it is considered as follows. When the density of the propylene-based polymer (b-1) and the density of the ethylene-based polymer wax (b-3) are within the above ranges, the ethylene-based polymer wax (b-) is added to the propylene-based polymer (b-1). It is considered that the ethylene polymer (b-2) is easily dispersed through (3). That is, since the ethylene-based polymer wax (b-3) acts as a compatibilizer for the propylene-based polymer (b-1) and the ethylene-based polymer (b-2), propylene used in the present embodiment. It is considered that the improved homogeneity of the polymer composition improves the balance of properties such as spinnability and strength of the nonwoven fabric.

When the propylene-based polymer composition (B) contains the ethylene-based polymer wax (b-3), the dispersion-improving effect by using the ethylene-based polymer wax (b-3) is more easily exhibited, and the fiber is From the viewpoint of making it thinner and the strength of the fiber, the content of the ethylene polymer wax (b-3) is 0.1 parts by mass or more and 4 parts by mass or more with respect to 100 parts by mass of the propylene polymer (b-1). It is preferably less than 0.5 parts by mass, more preferably 0.5 parts by mass to 3 parts by mass, further preferably 0.5 parts by mass to 2.5 parts by mass.

For the production of the propylene-based polymer composition (B), conventionally known catalysts, for example, JP-A-57-63310, JP-A-58-83006, JP-A-3-706, and JP-A-3476793. , JP-A-4-218508, JP-A-2003-105022 and the like; magnesium-supporting titanium catalysts; WO 2001/53369, WO 2001/27124, JP-A 3-1937996. The metallocene catalyst described in JP-A No. 02-41303 or the like can be preferably used.

In addition to the propylene-based polymer (b-1) and the ethylene-based polymer (b-2), the propylene-based polymer composition (B) may be, if necessary, within a range not impairing the object of the present invention. It may contain any other ingredient. These respective components can be mixed using various known methods.

The propylene-based polymer composition (B) may be optionally used as another component, other polymer; colorant: antioxidant such as phosphorus-based or phenol-based; benzotriazole-based, etc. Weather-resistant stabilizers; light-resistant stabilizers such as hindered amines; antiblocking agents; dispersants such as calcium stearate; lubricants; nucleating agents; pigments; softeners; hydrophilic agents; water repellents; auxiliaries; water repellents; fillers. Various antibacterial agents; agricultural chemicals; insect repellents; drugs; natural oils; synthetic oils;
In particular, in the case of imparting stability such as strength, discoloration, odor, etc. to radiation such as electron beam, it is effective to add an antioxidant, a weather resistance stabilizer, a light resistance stabilizer, a pigment, a deodorant and the like.

Examples of the stabilizer that can be used in the composition (B) include organic phosphorus compounds such as tris(2,4-di-tert-butylphenyl)phosphite; decanedioic acid bis(2,2,6,6- Tetramethyl-4-piperidinyl), 2,4-dichloro-6-(1,1,3,3-tetramethylbutylamino)-1,3,5-triazine.N,N'-bis(2,2,2 Hindered amine compounds such as 6,6-tetramethyl-4-piperidyl)hexamethylenediamine polycondensate; 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)-butane and the like. It is preferable to use a phenolic compound. It is more preferable to use a combination of these stabilizers, for example, an organophosphorus compound of tris(2,4-di-tert-butylphenyl)phosphite or bis(2,2,6,6-tetradecanedioate). Methyl-4-piperidinyl), and 2,4-dichloro-6-(1,1,3,3-tetramethylbutylamino)-1,3,5-triazine.N,N'-bis(2,2,2 At least one hindered amine compound of 6,6-tetramethyl-4-piperidyl)hexamethylenediamine polycondensate, and 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)- It is more preferable to include a phenolic compound of butane.
Also, fatty acid metal salts such as zinc stearate, calcium stearate, and calcium 1,2-hydroxystearate; glycerin monostearate, glycerin distearate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, etc. Polyhydric alcohol fatty acid ester; Further, these may be used in combination.

Composition (B) is silica, diatomaceous earth, alumina, titanium oxide, magnesium oxide, pumice powder, pumice balloon, aluminum hydroxide, magnesium hydroxide, basic magnesium carbonate, dolomite, calcium sulfate, potassium titanate. , Barium sulfate, calcium sulfite, talc, clay, mica, asbestos, calcium silicate, montmorillonite, pentonite, graphite, aluminum powder, molybdenum sulfide and the like may be contained.

The spunbonded nonwoven fabric (B) includes, in addition to the fibers obtained from the propylene-based polymer composition (B) described above, other fibers (for example, the propylene-based polymer described above) within a range not impairing the object of the present invention. (B-1) Fibers obtained from a simple substance, or fibers obtained from other olefin polymers, polyesters, thermoplastic elastomers, and the like) may be a nonwoven fabric made of mixed fibers.

The fiber forming the spunbonded nonwoven fabric (B) of the first embodiment may be a single fiber composed of the propylene-based polymer composition (B), and is within the range not impairing the object of the present invention. It may be a side-by-side composite fiber containing the polymer composition (B) or a composite fiber having a core-sheath structure.

The cross-sectional shape of the fibers forming the spunbond nonwoven fabric (B) may be a round shape; a polygonal shape such as a star shape, a triangular shape, a square shape, and a pentagonal shape; an oval shape; a hollow shape;

(Physical properties of spunbond nonwoven fabric (B))
The spunbonded nonwoven fabric (B) used in the nonwoven fabric laminate of the first embodiment has a basis weight of 20 g/m ² and a flow rate condition of 125 Pa with a pressure difference of 125 Pa measured by a Frazier air permeability meter according to JIS L 1096 (2010). The air permeability measured by the method is 500 cm ³ /cm ² /s or less. It is preferably 450 cm ³ /cm ² /s or less, and preferably 400 cm ³ /cm ² /s or less. The lower limit value is not particularly limited, but may be 50 cm ³ /cm ² /s or more. It is preferably 100 cm ³ /cm ² /s or more, more preferably 200 cm ³ /cm ² /s or more. When the air permeability of the spunbonded nonwoven fabric is within this range, appropriate air permeability and barrier properties can be obtained. In addition, the obtained spunbonded nonwoven fabric has excellent strength. When the air permeability is in such a range, the nonwoven fabric laminate of the present embodiment can be suitably used for medical materials and the like, because it has the above-mentioned characteristics.

Basis weight of the spunbonded nonwoven fabric (B) ^is preferably in the range of ^{5g / m 2 ~50g / m 2} , and more preferably in the range of ^{10g / m 2 ~25g / m 2} .

The average fiber diameter of the fibers forming the spunbond nonwoven fabric (B) is preferably in the range of 5 μm to 30 μm. The upper limit of the average fiber diameter is more preferably 25 μm or less, still more preferably 20 μm or less. In particular, when it is 20 μm or less, the fibers forming the non-woven fabric become sufficiently thin, and it can be used particularly suitably for medical materials and the like. Moreover, the lower limit of the average fiber diameter is not particularly limited, but if it is 10 μm or more, a material having excellent strength can be obtained.

The spunbonded non-woven fabric (B) has a MD (longitudinal direction: machine direction at the time of non-woven fabric production) strength of 20 N or more and a CD as the strength after being irradiated with an electron beam having an absorbed dose of 45 kGy at a basis weight of 20 g/m ² . The strength (lateral direction) is preferably 10 N or more. More preferably, the MD strength is 25 N or higher and the CD strength is 15 N or higher. When the strength is within the above range, it is difficult for the non-woven fabric to be perforated or torn, which is preferable.
Here, the absorbed dose is a dose when 1 joule of energy is absorbed per 1 kg, and is represented by Gy.

Further, the intensity INDEX after irradiation with an electron beam having an absorbed dose of 45 kGy at a basis weight of 20 g/m ² is preferably 10 N or more. It is more preferably 13 N or more, and most preferably 18 N or more. When the strength INDEX of the spunbonded nonwoven fabric (B) is in this range, the spunbonded nonwoven fabric (B) has sufficiently excellent strength even after being irradiated with an electron beam. When the strength INDEX after being irradiated with an electron beam is in this range, the strength becomes sufficiently excellent, and it is particularly preferable in that it can be suitably used for medical materials and the like.
In this specification, the strength INDEX is a value calculated by the following formula.
[Formula]: Strength INDEX=((((MD strength) ² +(CD strength) ² ))/2) ^0.5

(Method for producing spunbond nonwoven fabric (B))
The spunbonded nonwoven fabric (B) that can be used in the first embodiment can be manufactured by a known spunbonded nonwoven fabric manufacturing method. Specifically, for example, the above-mentioned propylene-based polymer composition (B) is spun in advance from a spinning nozzle, the spun long-fiber filament is cooled with a cooling fluid, and tension is applied to the filament by drawing air. The spunbonded non-woven fabric having a predetermined fineness and the obtained filaments is collected on a moving collection belt to be deposited into a predetermined thickness to produce a spunbonded nonwoven fabric.
Further, the deposited web can be entangled as necessary. Examples of the entanglement method include a method of hot embossing using an embossing roll; a method of fusion by ultrasonic waves; a method of entanglement of fibers using a water jet; a method of fusion by hot air through; a needle punch. Various methods such as the method used; and the like can be appropriately used.

The spunbonded non-woven fabric (B) is preferably a non-woven fabric which is partially thermocompression bonded by embossing or the like from the viewpoint that the strength and the like are further improved and the flexibility and air permeability are balanced. When the spunbonded nonwoven fabric (B) is thermocompression bonded by hot embossing, the embossed area ratio (thermocompression bonding portion) is preferably 5% to 30%. It is more preferably in the range of 5% to 20%. Examples of the engraved shape include a circle, an ellipse, an oval, a square, a diamond, a rectangle, a square, a quilt, a lattice, a turtle shell, and a continuous shape based on these shapes.

The spunbonded non-woven fabric (B) is subjected to secondary processing such as gear processing, printing, coating, laminating, heat treatment, shaping processing, hydrophilic processing, water repellent processing, press processing, etc. within a range that does not impair the object of the present invention. May be. The above-mentioned secondary processing can be performed after forming a nonwoven fabric laminate containing the spunbonded nonwoven fabric (B).

The spunbonded nonwoven fabric (B) can be subjected to a processing treatment such as water repellency, if necessary. The processing such as water repellency can be performed by applying a processing agent such as a fluorine-based water repellent or by mixing the resin repellant as an additive with the resin raw material in advance to form a nonwoven fabric. A suitable amount (content) of the water repellent is 0.5% by mass to 5.0% by mass based on the total mass of the nonwoven fabric.
Examples of the method of imparting alcohol repellency include a method of attaching a fluorine-based processing agent to the spunbond nonwoven fabric (B) in an amount of 0.01% by mass to 3% by mass. In this case, the method of attaching the processing agent and the method of drying are not particularly limited. The method of attaching the processing agent includes a method of spraying; a method of dipping in a processing agent bath and squeezing with a mangle; a method of coating; and the like, and a drying method of using a hot air dryer; a method of using a tenter. A method of contacting with a heating element;

By the above-mentioned processing, for example, when a nonwoven fabric laminate containing the spunbonded nonwoven fabric (B) is used in a medical gown, it becomes difficult for water, alcohol, oil, etc. to permeate, and when the alcohol is sterilized, Even if blood or the like adheres, it has a high barrier property. The above processing can be applied to a nonwoven fabric laminate including the spunbonded nonwoven fabric (B).

Further, the spunbonded nonwoven fabric (B) may be provided with antistatic property. As a method of imparting antistatic property, a method of applying an appropriate antistatic property imparting agent (for example, fatty acid ester, quaternary ammonium salt, etc.) or a method of forming a non-woven fabric by mixing the resin raw material as an additive, Are listed. The degree of antistatic property is preferably 1000 V or less (the friction cloth is a cotton cloth) according to the method shown in JIS L1094C in an atmosphere of 20° C. and 40% RH.

By imparting the antistatic property, it is possible to improve comfort when, for example, the nonwoven fabric laminate according to the first embodiment in which the spunbonded nonwoven fabric (B) is laminated is used in a medical gown or the like. .. The above processing can be applied to a nonwoven fabric laminate including the spunbonded nonwoven fabric (B).

<Nonwoven fabric laminate according to the second embodiment>
In the nonwoven fabric laminate according to the second embodiment, a continuous long fiber nonwoven fabric made of fibers composed of the ethylene-based polymer composition (C) is provided on at least one surface of the melt blown nonwoven fabric of the present embodiment described above. It is a non-woven fabric laminated body.

The continuous long-fiber nonwoven fabric made of fibers composed of the ethylene-based polymer composition (C) is preferably a melt blown nonwoven fabric, as described in detail below.

[Continuous long-fiber nonwoven fabric composed of fibers composed of ethylene-based polymer composition (C)]
The continuous long-fiber nonwoven fabric included in the nonwoven fabric laminate according to the second embodiment is a nonwoven fabric made of fibers composed of the ethylene-based polymer composition (C).
The continuous long-fiber non-woven fabric made of fibers composed of the ethylene polymer composition (C)) is preferably a melt-blown non-woven fabric (hereinafter sometimes referred to as “melt-blown non-woven fabric (C)”).
Hereinafter, the ethylene-based polymer composition (C) constituting the continuous long-fiber nonwoven fabric, preferably the meltblown nonwoven fabric (C) will be described.

(Ethylene-based polymer composition (C))
The ethylene-based polymer composition (C) (hereinafter sometimes referred to as the composition (C)) is an ethylene-based polymer (c-1) having a melt flow rate (MFR) of 10 g/10 minutes to 250 g/10 minutes. ) And an ethylene-based polymer wax (c-2) having a weight average molecular weight (Mw) of 400 to 15000, wherein the ethylene-based polymer (c-1) is contained in the ethylene-based polymer wax (c-2). The amount is preferably in the range of 90/10 to 10/90 in terms of mass ratio [(c-1)/(c-2)].

By using the fiber containing the ethylene polymer composition (C) containing the ethylene polymer (c-1) and the ethylene polymer wax (c-2) in the above-described preferable mass ratio, In addition to suppressing the decrease in strength and the decrease in barrier property after electron beam irradiation, the fiber diameter can be reduced, and the spinnability is further improved.

(Ethylene-based polymer (c-1))
The ethylene polymer (c-1), which is one of the components of the fibers forming the meltblown nonwoven fabric (C) used in the nonwoven fabric laminate of the second embodiment, is the same as the ethylene polymer (b-2). The resin is a homopolymer of ethylene or a polymer mainly composed of ethylene which is a copolymer of ethylene and another α-olefin.
The density of the ethylene-based polymer (c-1) ^is preferably in the range of ^{0.870g / cm 3 ~0.990g / cm 3} , more preferably in the range of ^{0.900g / cm 3 ~0.980g / cm 3} , The range of 0.910 g/cm ^{3 to} 0.980 g/cm ³ is more preferable, and the range of 0.940 g/cm ^{3 to} 0.980 g/cm ³ is the most preferable.

The ethylene-based polymer (c-1) is a crystalline resin that is usually manufactured and sold under the names such as high-pressure low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene.

Other α-olefins copolymerized with ethylene include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1- Examples of the α-olefin having 3 to 20 carbon atoms such as tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. These ethylene polymers may be used alone or as a mixture of two or more kinds.

The melt flow rate of the ethylene polymer (c-1) (MFR ₁₉₀ : measured at 190° C. under a load of 2.16 kg in accordance with ASTM D1238) is a melt blown nonwoven fabric using the ethylene polymer (c-1). There is no particular limitation as long as it can be produced, but a range of 10 g/10 minutes to 250 g/10 minutes is preferable. The range of 20 g/10 minutes to 200 g/10 minutes is more preferable, and the range of 50 g/10 minutes to 150 g/10 minutes is further preferable. When the melt flow rate of the ethylene polymer (c-1) is in this range, the obtained fiber diameter is likely to be smaller and the spinnability is better, which is desirable.

The ethylene-based polymer (c-1) is, like the ethylene-based polymer (b-2), various known production methods (for example, a high-pressure method, a medium-low pressure method obtained by using a Ziegler catalyst or a metallocene catalyst). The polymer obtained by can be used.

(Ethylene polymer wax (c-2))
The ethylene-based polymer wax (c-2), which is one of the components of the fibers forming the meltblown nonwoven fabric (C), is a wax-like resin similar to the ethylene-based polymer wax (b-3), and is ethylene-based. It has a lower molecular weight than the polymer (c-1), that is, a waxy polymer.
Further, it can be obtained by the same production method as the ethylene polymer wax (b-3).

The weight average molecular weight (Mw) of the ethylene polymer wax (c-2) is preferably in the range of 400 to 15,000, more preferably in the range of 1,000 to 15,000, further preferably in the range of 6,000 to 15,000, and in the range of 6,000 to 10,000. Is particularly preferable. Most preferably, it is in the range of 6500-10000. When the weight average molecular weight (Mw) of the ethylene polymer wax (c-2) is within this range, it is preferable because the fibers formed of the meltblown nonwoven fabric (C) are likely to be sufficiently thin.

The density of the ethylene polymer wax ^(c-2), preferably ^{0.890g / cm 3 ~0.985g / cm 3} , more preferably 0.910 g / cm ³ or more, 0.930 g / cm ³ or more and more It is preferably 0.950 g/cm ³ or more, more preferably 0.960 g/cm ³ or more. Further, it is preferably 0.980 g/cm ³ or less. When the ethylene polymer wax (c-2) having a density in such a range is used, it has excellent kneadability with the ethylene polymer (c-1), and has spinnability and stability over time. Is preferable because it is more excellent. Moreover, the obtained meltblown nonwoven fabric (C) is preferably laminated with the meltblown nonwoven fabric of the present embodiment described above, because the fibers are more difficult to melt during embossing thermocompression bonding when forming a nonwoven fabric laminate.

In the ethylene polymer composition (C), the content of the ethylene polymer (c-1) with respect to the ethylene polymer wax (c-2) is a mass ratio [(c-1)/(c-2). )] is preferably 90/10 to 10/90, as described above. When the mass ratio of [(c-1)/(c-2)] is within this range, the fibers composed of the meltblown nonwoven fabric (C) can be made sufficiently thin, and the spinnability is superior. In addition, the obtained meltblown nonwoven fabric (C) is preferable in that the fibers are less likely to be damaged during embossing thermocompression bonding when the nonwoven fabric laminate is formed by laminating the meltblown nonwoven fabric (C) described above. ..

<Nonwoven fabric laminate according to the third embodiment>
The non-woven fabric laminate according to the third embodiment has a propylene-based polymer composition ((A) different from the propylene-based polymer composition (A) described above on one surface of the melt-blown non-woven fabric of the present embodiment described above. A spunbonded nonwoven fabric composed of fibers composed of B) is laminated, and a continuous long-fiber nonwoven fabric composed of the ethylene polymer composition (C) is laminated on the other surface of the nonwoven fabric laminate.
In the nonwoven fabric laminate according to the third embodiment, a spunbonded nonwoven fabric (B) made of fibers composed of a propylene-based polymer composition (B) is laminated on one surface of the melt blown nonwoven fabric of the present embodiment described above. A non-woven fabric laminate having a three-layer structure in which a continuous long-fiber non-woven fabric made of an ethylene-based polymer composition (C), preferably a melt blown non-woven fabric (C), is laminated on the other surface.
The spunbonded nonwoven fabric (B) and meltblown nonwoven fabric (C) contained in the nonwoven fabric laminate according to the third embodiment are the nonwoven fabrics described in the nonwoven fabric laminate according to the above-described first and second embodiments. Is similar to.
A spunbonded non-woven fabric (B)/melt-blown non-woven fabric of the present embodiment/melt-blown non-woven fabric (C)/melt-blown non-woven fabric of the present embodiment/spun-bonded non-woven fabric (B) may have a five-layer structure.

A method for producing a non-woven fabric laminate in which at least one non-woven fabric selected from a spun bond non-woven fabric (B) and a melt blown non-woven fabric (C) is laminated on a melt blown non-woven fabric is a method capable of forming a non-woven fabric laminate by integrating a plurality of non-woven fabrics There is no particular limitation.

Specifically, for example, the following methods can be adopted, but the method is not limited to these.
(I) A propylene-based polymer composition (A) that forms the meltblown nonwoven fabric of this embodiment or an ethylene-based polymer that forms the meltblown nonwoven fabric (C) on the surface of the previously obtained spunbonded nonwoven fabric (B). A method for producing a two-layer laminate by directly depositing fibers obtained from the composition (C) to form a meltblown nonwoven fabric, and then fusing the spunbonded nonwoven fabric (B) and the meltblown nonwoven fabric by heat embossing or the like.
(Ii) A fiber obtained from the propylene polymer composition (A) obtained by the melt blown method is deposited to form a melt blown nonwoven fabric, and further obtained from the propylene polymer composition (B) formed by the spun bond method. A method for producing a nonwoven fabric laminate by directly depositing the fibers to be formed on the meltblown nonwoven fabric to form a spunbonded nonwoven fabric (B), and then fusing the meltblown nonwoven fabric and the spunbonded nonwoven fabric (B).
(Iii) At least one layer of the spunbonded nonwoven fabric (B) and the meltblown nonwoven fabric (C) separately produced is superposed on the previously obtained meltblown nonwoven fabric of the present embodiment, and both the nonwoven fabrics are heated and pressed. A method for producing a two-layer or three-layer nonwoven fabric laminate by fusing.
(Iv) The melt-blown non-woven fabric obtained in advance and at least one layer of the spunbonded non-woven fabric (B) and the melt-blown non-woven fabric (C) separately produced are bonded together by an adhesive such as a hot-melt adhesive or a solvent-based adhesive. A method for producing a two-layer or three-layer nonwoven fabric laminate.
(V) The previously obtained meltblown nonwoven fabric of the present embodiment is laminated on both sides of the previously obtained meltblown nonwoven fabric (C), and the spunbonded nonwoven fabric (B) separately produced is laminated on both outer surfaces thereof. Then, the spunbonded non-woven fabric (B)/melt-blown non-woven fabric of the present embodiment/melt-blown non-woven fabric (C)/melt-blown non-woven fabric of the present embodiment/spun-bonded non-woven fabric (B) is formed into a five-layer structure by fusion bonding by heat emboss A method for manufacturing a laminate.

The method of laminating the meltblown nonwoven fabric and the spunbonded nonwoven fabric by heat fusion includes a method of heat-sealing the entire contact surface of both nonwoven fabrics, or a method of heat-sealing a part of the contact surfaces. It is preferable to fuse a part of the contact surface of each nonwoven fabric layer by a processing method. In this case, the fused area (embossed area ratio: this corresponds to the engraved area of the embossing roll) is preferably 5% to 30% of the contact area, and more preferably 10% to 20%. When the fused area is in this range, the nonwoven fabric laminate has excellent barrier properties and a good balance between adhesive strength and flexibility.
When performing hot embossing, the embossing temperature is generally in the range of 85°C to 150°C, although it depends on the line speed and the pressure of pressure during the embossing.

As a method other than laminating the spun bond nonwoven fabric and the melt blown nonwoven fabric by heat fusion, there is a method of laminating the spun bond nonwoven fabric and the melt blown nonwoven fabric with an adhesive. Examples of the hot melt adhesive used in this method include vinyl acetate-based and polyvinyl alcohol-based resin-based adhesives; styrene-butadiene-based and styrene-isoprene-based rubber-based adhesives, and the like. Examples of the solvent-based adhesive include rubber-based adhesives such as styrene-butadiene-based, styrene-isoprene-based and urethane-based adhesives; resin-based organic solvents such as vinyl acetate and vinyl chloride or water-based emulsion adhesives. .. Among these adhesives, rubber-based hot-melt adhesives such as styrene-isoprene-based and styrene-butadiene-based adhesives are preferable because they do not impair the texture which is a characteristic of the spunbonded nonwoven fabric.

In the nonwoven fabric laminate of the meltblown nonwoven fabric and the spunbonded nonwoven fabric, the peel strength between the meltblown nonwoven fabric layer and the spunbonded nonwoven fabric layer is preferably 0.1 N or more, more preferably 0.5 N or more, Most preferably, it does not peel.

<Medical clothing>
The medical treatment of the present embodiment includes the melt blown nonwoven fabric of the present embodiment described above, or the nonwoven fabric laminate of any of the first embodiment to the first embodiment.
As described above, the melt-blown nonwoven fabric of the present embodiment is flexible and has high water pressure resistance, and can be subjected to radiation sterilization treatment by an electron beam or the like, and a decrease in strength after radiation sterilization treatment is suppressed, further, The non-woven fabric laminates of the first embodiment to the first embodiment are all non-woven fabric laminates containing the melt-blown non-woven fabric of the present embodiment described above, and thus the medical clothing of the present embodiment is, The decrease in strength after radiation sterilization is suppressed, and the non-woven fabric laminate has excellent adhesive strength between layers and the non-woven fabric laminate is also excellent in durability, flexibility, and water repellent treatment. The surface treatment can be easily performed.
Examples of medical clothing include white coats, work clothes, surgical gowns worn by medical staff such as doctors and nurses.

<Drape>
The drape of the present embodiment includes the melt blown nonwoven fabric of the present embodiment described above, or the nonwoven fabric laminate of any of the first embodiment to the first embodiment.
As described above, the melt blown nonwoven fabric of the present embodiment is flexible and has high strength, and thus can be applied to various applications as a drape.
The drape of the present embodiment has a high water pressure resistance and can be subjected to radiation sterilization treatment with an electron beam or the like, and the decrease in strength after the radiation sterilization treatment is suppressed. Further, since the nonwoven fabric laminates of the first to third embodiments are all nonwoven fabric laminates containing the melt blown nonwoven fabric of the present embodiment described above, the reduction in strength after radiation sterilization is suppressed. In addition, the nonwoven fabric laminate has excellent adhesive strength between layers, and also has excellent strength of the nonwoven fabric laminate, and thus has good durability and flexibility, and surface treatment such as water repellent treatment can be easily performed. .. Therefore, it can be used not only for medical applications such as surgical drapes, sheets, and bed covers, but also as a drape for covering and protecting various articles, among which it is preferably used as a surgical drape.

(Other uses)
Further, the meltblown nonwoven fabric and the nonwoven fabric laminate of the present embodiment are suitably used not only for medical clothing and drapes, but also as bandages as sanitary materials, medical gauze, medical sanitary materials such as towels, sanitary masks, etc. To be done.

Hereinafter, the present invention will be described more specifically based on Examples, but the present invention is not limited to these Examples.
Physical property values and the like in Examples and Comparative Examples were measured by the following methods.

(1) Unit weight [g/m ² ]
Ten points were taken from the nonwoven fabric in a machine direction (MD) of 100 mm and a transverse direction (CD) of 100 mm. It should be noted that the sampling points were arbitrarily set at 10 points. Next, the mass (g) of each of the collected test pieces was measured using a plate electronic balance (manufactured by Kensei Kogyo Co., Ltd.). The average value of the mass of each test piece was calculated. The obtained average value was converted into a mass (g) per 1 m ² , and the decimal point was rounded off to obtain a basis weight [g/m ² ] of the nonwoven fabric.

(2) Tensile strength (N/50 mm) strength INDEX, and elongation Nonwoven fabric before irradiation with electron beam or nonwoven fabric laminate, and nonwoven fabric irradiated with electron beam of absorbed dose of 45 kGy or nonwoven fabric laminate, JIS L It was measured according to 1906. A test piece of width 50 mm x length 200 mm was taken from the non-woven fabric, and a tensile tester (Autograph AGS-J manufactured by Shimadzu Corp.) was used. Distance between chucks was 100 mm, head speed was 300 mm/min, MD: 5 points, CD: 5 The points were measured, the average value of the maximum strength and the average value of the elongation at the time of measuring the maximum strength were calculated, and the tensile strength (N/50 mm) and the elongation (%) were obtained. The strength INDEX was calculated by the following formula.
[Formula] Strength INDEX=[[(MD strength) ² +(CD strength) ² )]/2] ^0.5

Further, the elongation INDEX was calculated from the obtained elongation by the following formula.
[Formula] Elongation INDEX=[[((MD elongation) ² +(CD elongation) ² )]/2] ^0.5

(3) Air permeability (cm ³ /cm ² /sec)
A 150 mm (MD) x 150 mm (CD) test piece was sampled from the non-woven fabric, and the test piece was measured with a Frazier air permeability meter according to JIS L1096. The average value of n=5 was used as the measured value.

(4) Water resistance (barrier property)
Regarding the non-woven fabric laminate before irradiation with an electron beam and the non-woven fabric laminate irradiated with an electron beam having an absorbed dose of 45 kGy, the non-woven fabric laminate is compliant with the A method (low water pressure method) defined in JIS L 1096. The water pressure resistance was measured and used as an index of water resistance (barrier property).

(5) Evaluation of Adhesion Between Layers After a spunbonded nonwoven fabric layer (SB layer) and a meltblown nonwoven fabric layer (MB layer) were laminated by the method shown in the example, a test piece having a width of 25 mm and a length of 250 mm was collected, The SB-MB plane or the MB-MB plane was peeled off, the peeled end faces were gripped by the upper and lower chucks (gripping interval 50 mm), and the strength was measured at a pulling speed of 200 mm/min. The maximum load was read at 5 points, and the average value was taken as one measurement value. The average value of n=3 was used as the measured value, and the evaluation was performed according to the following criteria.
AA: Peel strength 1.0 N or more or the sample breaks without peeling A: Peel strength 0.5 N to less than 1.0 N B: Peel strength 0.1 N to less than 0.5 N C: Peel strength less than 0.1 N D : Peeling off spontaneously and measurement is not possible

(6) Evaluation of shots For evaluation of shots, the surface of the meltblown non-woven fabric that has been statically measured on a flat surface is checked by touch and the presence or absence of granular defects is confirmed by palpation, or a light source such as an electric light is passed through. There is a method of visually confirming the presence or absence of granular defects. If a grainy defect can be confirmed by at least one evaluation of the two described methods, a shot is “Yes”, and if a grainy defect cannot be confirmed by any of the two methods, a shot is “No”. did.

(Example 1)
<Manufacture of PER meltblown non-woven fabric (MB)>
Propylene/ethylene copolymer [manufactured by ExxonMobil: product name “Vistamaxx ^™ 6202”, MFR (230° C., 2.16 kg load): 20 g/10 min, ethylene content: 15 wt%] 40 parts by mass, propylene polymer wax [ Density: 0.900 g/cm ³ , weight average molecular weight: 7800, softening point 148°C, ethylene content: 1.7 wt% 40 parts by mass, propylene homopolymer [MFR: 1500 g/10 minutes, weight average molecular weight (Mw) : 54000] 20 parts by mass, (I) tris(2,4-di-tert-butylphenyl)phosphite as an organophosphorus compound [manufactured by ADEKA CORPORATION, product name "ADEKA STAB 2112"] 0.2 parts by mass , (II) as a hindered amine compound, 2,4-dichloro-6-(1,1,3,3-tetramethylbutylamino)-1,3,5-triazine.N,N'-bis(2,2 , 6,6-Tetramethyl-4-piperidyl)hexamethylenediamine polycondensate [manufactured by ADEKA CORPORATION, product name "ADEKA STAB LA-94G"] 0.15 parts by mass, decanedioic acid bis(2,2,6) , 6-Tetramethyl-4-piperidinyl) [manufactured by ADEKA CORPORATION, product name "ADEKA STAB LA-77Y"] 0.05 part by mass, 1,1,3-tris(2- Methyl-4-hydroxy-5-t-butylphenyl)-butane [manufactured by ADEKA CORPORATION, product name "ADEKA STAB AO-30"] 0.1 part by mass, 2-[5-chloro(2H )-Benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol [manufactured by ADEKA CORPORATION, product name "ADEKA STAB LA-36"] 0.15 parts by mass of a mixture [propylene-based polymer] Using the composition (A)], a molten resin is discharged at a rate of 0.15 g/min per hole from a spinneret having a nozzle of 0.4 mmφ and 760 holes, and melt spinning is performed by a melt blown method to form microfibers. Then, the melt-blown non-woven fabric (hereinafter, may be referred to as MB or MB non-woven fabric) was manufactured by depositing on the collecting surface and aiming at a basis weight of 20 g/m ² .
The physical properties of the obtained MB nonwoven fabric were measured by the methods described above. The results are shown in Table 1.

<Manufacture of spunbond nonwoven fabric (SB)>
MFR: 60 g/10 min, density: 0.910 g/cm ³ 100 parts by mass of propylene homopolymer (PP), high-density polyethylene (PE, manufactured by Prime Polymer Co., Ltd., trade name “Hi-Zex HZ2200J”, MFR=5 Melt-spinning was performed at 230° C. using a mixture [propylene polymer composition (B)] containing 0.2 g/10 min and a density of 0.964 g/cm ³ ) 4 parts by mass, and the obtained fiber was supplemented. After being deposited on the collecting surface, a spunbonded nonwoven fabric (hereinafter sometimes referred to as SB or SB nonwoven fabric) having a fiber diameter of 18 μm and a basis weight of 20 g/m ² was obtained by hot embossing.

<Manufacture of SMS nonwoven fabric laminate>
The spunbonded non-woven fabric (SB) obtained above is laminated on both sides of the melt-blown non-woven fabric (MB) obtained above, and heat fusion is performed by heat embossing (engraved area ratio 18%) at 110° C. and a linear pressure of 1 Mpa. Then, a non-woven fabric laminate (SMS non-woven fabric laminate) having a three-layer structure of SB/MB/SB was obtained. The physical properties of the obtained SMS nonwoven fabric laminate were measured by the methods described above. The results are shown in Table 2.

(Example 2)
<Manufacture of PER meltblown non-woven fabric (MB)>
A PER mixed meltblown nonwoven fabric (MB) was produced in the same manner as in Example 1 except that the weight per unit area was set to 6.5 g/m ² .

<Manufacture of PE-based meltblown nonwoven fabric (MB)>
80 parts by mass of ethylene/1-hexene copolymer [manufactured by Prime Polymer Co., Ltd., product name: Evolue H SP50800P, density: 0.951 g/cm ³ , MFR: 135 g/10 min], and an ethylene polymer wax [Density: 0.980 g/cm ³ , weight average molecular weight: 6900, softening point 135°C] Using a mixture containing 20 parts by mass [ethylene-based polymer composition (C)], 0.4 mmφ, 760 holes Molten resin is discharged at 0.15 g/min per hole from a spinneret having a nozzle, melt spinning is performed by a melt blown method to form microfibers, and the microfibers are deposited on a collecting surface, and a basis weight of 6.5 g/m ² As a target, a melt blown nonwoven fabric (MB) was manufactured.

<Manufacture of SMS nonwoven fabric laminate>
6.5 g/m ² of the PER meltblown nonwoven fabric (MB) was laminated on both surfaces of the 6.1 g/m ² PE-based meltblown nonwoven fabric (MB) obtained above, and Example 1 and The same spunbonded non-woven fabric (SB) is laminated and heat-bonded by hot embossing (engraved area ratio 18%) at 110° C. and a linear pressure of 1 Mpa to obtain SB/MB [PER type]/MB [PE type]/ An SMS nonwoven fabric laminate having a five-layer structure of MB [PER type]/SB was obtained. The physical properties of the obtained SMS nonwoven fabric laminate were measured by the methods described above. The results are shown in Table 2.

(Comparative Example 1)
PER meltblown nonwoven fabric (MB) In the same manner as in Example 1 except that the ratio of each raw material was 40 parts by mass of propylene/ethylene copolymer and 60 parts by mass of propylene homopolymer, and no propylene polymer wax was used. A PER meltblown nonwoven fabric (MB) was obtained. The physical properties of the obtained MB nonwoven fabric were measured by the methods described above. The results are shown in Table 1.
Further, using the obtained MB non-woven fabric of Comparative Example 1, an SMS non-woven fabric laminate of Comparative Example 1 was obtained in the same manner as in Example 1. The physical properties of the obtained SMS nonwoven fabric laminate were measured by the methods described above. The results are shown in Table 2.

(Comparative example 2)
PER meltblown nonwoven fabric (MB) In the same manner as in Example 2 except that the ratio of each raw material was 40 parts by mass of propylene/ethylene copolymer and 60 parts by mass of propylene homopolymer, and no propylene polymer wax was used. A PER meltblown nonwoven fabric (MB) was obtained. Using the obtained MB nonwoven fabric, an SMS nonwoven fabric laminate of Comparative Example 2 having a five-layer structure was obtained in the same manner as in Example 2. The physical properties of the obtained nonwoven fabric were measured by the methods described above. The results are shown in Table 2.

(Comparative example 3)
PER meltblown nonwoven fabric (MB) A PER meltblown nonwoven fabric (MB) was prepared in the same manner as in Example 1 except that the ratio of each raw material was 60 parts by mass of propylene/ethylene copolymer and 40 parts by mass of propylene polymer wax. Obtained. The physical properties of the obtained MB nonwoven fabric were measured by the methods described above. The results are shown in Table 1.
Further, using the obtained MB nonwoven fabric, an SMS nonwoven fabric laminate was obtained in the same manner as in Example 1. The physical properties of the obtained SMS nonwoven fabric laminate were measured by the methods described above. The results are shown in Table 2.

(Comparative Example 4)
PER meltblown nonwoven fabric (MB) Same as Example 2 except that the ratio of each raw material was 60 parts by mass of propylene/ethylene copolymer and 40 parts by mass of propylene/ethylene polymer wax and no propylene homopolymer was used. To obtain a PER meltblown nonwoven fabric (MB). Using the obtained MB nonwoven fabric, an SMS nonwoven fabric laminate having a five-layer structure was obtained in the same manner as in Example 2. The physical properties of the obtained nonwoven fabric were measured by the methods described above. The results are shown in Table 2.

(Comparative example 5)
<Production of PP melt blown nonwoven fabric (MB)>
Based on 100 parts by mass of propylene homopolymer [MFR: 1500 g/10 minutes, weight average molecular weight (Mw): 54000], tris(2,4-di-tert-butylphenyl) as the (A) organic phosphorus compound. Phosphite [manufactured by ADEKA CORPORATION, product name "Adeka Stub 2112"] 0.4 parts by mass, (B) hindered amine compound as 2,4-dichloro-6-(1,1,3,3-tetramethylbutyl) Amino)-1,3,5-triazine.N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine polycondensate [manufactured by ADEKA CORPORATION, product name "ADEKA STAB"LA-94G"] 0.3 parts by mass, decanedioate bis(2,2,6,6-tetramethyl-4-piperidinyl) [manufactured by ADEKA CORPORATION, product name "ADEKA STAB LA-77Y"] 0.1 Mass part, as (C) phenolic compound, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)-butane [manufactured by ADEKA CORPORATION, product name "ADEKA STAB AO-30" ] 0.2 parts by mass, as a triazole-based compound, 2-[5-chloro(2H)-benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol [manufactured by ADEKA CORPORATION, Product name "ADEKA STAB LA-36"] 0.3 part by mass was added to obtain a thermoplastic resin composition. Using the composition, a molten resin was discharged at a rate of 0.15 g/min per single hole from a spinneret having a nozzle of 0.4 mmφ and 760 holes, melt spinning was performed by a melt blown method, and microfibers were molded and captured. The melt blown nonwoven fabric (MB) was manufactured by depositing on the collecting surface and aiming at a basis weight of 20 g/m ² . The physical properties of the obtained MB nonwoven fabric of Comparative Example 5 were measured by the methods described above. The results are shown in Table 1.

<Manufacture of SMS nonwoven fabric laminate>
The spunbonded nonwoven fabric (SB) was laminated on both sides of the meltblown nonwoven fabric (MB) obtained above, and heat-bonded by thermal embossing (engraved area ratio 18%) at 120° C. and a linear pressure of 1 Mpa, and An SMS nonwoven fabric laminate having a layered structure was obtained. The physical properties of the obtained SMS nonwoven fabric laminate of Comparative Example 5 were measured by the methods described above. The results are shown in Table 2.

(Comparative example 6)
A PER meltblown nonwoven fabric (MB) of Comparative Example 6 was obtained in the same manner as in Example 2 except that the raw material of the PER meltblown nonwoven fabric (MB) was changed to the same raw material as the PP meltblown nonwoven fabric (MB) of Comparative Example 5. .. Using the obtained MB nonwoven fabric, an SMS nonwoven fabric laminate of Comparative Example 6 having a five-layer structure was obtained in the same manner as in Example 2. The physical properties of the obtained nonwoven fabric were measured by the methods described above. The results are shown in Table 2.

(Comparative Example 7)
The raw material of the PER meltblown non-woven fabric (MB) was 10 parts by mass of the propylene/ethylene copolymer, 90 parts by mass of the propylene homopolymer [MFR: 1100 g/10 min, weight average molecular weight (Mw): 97000], and the propylene series was used. An MB nonwoven fabric of Comparative Example 7 was obtained in the same manner as in Example 1 except that the polymer wax was not used. The physical properties of the obtained nonwoven fabric were measured by the methods described above. The results are shown in Table 1.

(Comparative Example 8)
The raw material of the PER meltblown non-woven fabric (MB) was 20 parts by mass of the propylene/ethylene copolymer, 80 parts by mass of the propylene homopolymer [MFR: 1100 g/10 minutes, weight average molecular weight (Mw): 97000], and the propylene series was used. An MB nonwoven fabric of Comparative Example 8 was obtained in the same manner as in Example 1 except that the polymer wax was not used. The physical properties of the obtained nonwoven fabric were measured by the methods described above. The results are shown in Table 1.

(Comparative Example 9)
The raw material of the PER meltblown nonwoven fabric (MB) was 100 parts by mass of a propylene/ethylene copolymer [MFR: 60 g/10 min, melting point: 143° C., ethylene content: 3.0% by weight], and a propylene homopolymer and An MB nonwoven fabric of Comparative Example 9 was obtained in the same manner as in Example 1 except that the propylene polymer wax was not used. The physical properties of the obtained nonwoven fabric were measured by the methods described above. The results are shown in Table 1.

(Comparative Example 10)
PER meltblown non-woven fabric (MB) The ratio of each raw material was 100 parts by mass of propylene/ethylene copolymer [MFR: 60 g/10 min, melting point: 143° C., ethylene content: 3.0% by weight], and propylene alone weight An SMS nonwoven fabric laminate of Comparative Example 10 having a five-layer structure was obtained in the same manner as in Example 2 except that the coalescence and the propylene polymer wax were not used. The physical properties of the obtained nonwoven fabric were measured by the methods described above. The results are shown in Table 2.

(Comparative Example 11)
<Manufacture of PE-based meltblown nonwoven fabric (MB)>
80 parts by mass of ethylene/1-hexene copolymer [manufactured by Prime Polymer Co., Ltd., product name: Evolue H SP50800P, density: 0.951 g/cm ³ , MFR: 135 g/10 min], and an ethylene polymer wax [Density: 0.980 g/cm ³ , weight average molecular weight: 6900, softening point 135° C.] Using a mixture of 20 parts by mass, from a spinneret having a nozzle of 0.4 mmφ and 760 holes, 0.15 g per single hole The molten resin was discharged at a flow rate of 1/min, and melt spinning was performed by the melt blown method to form microfibers, which were deposited on the collecting surface, and a melt blown nonwoven fabric (MB) of Comparative Example 11 was produced with a basis weight of 20 g/m ² .

<Manufacture of SMS nonwoven fabric laminate>
The spunbonded nonwoven fabric (SB) was laminated on both sides of the meltblown nonwoven fabric (MB) obtained above, and heat fusion was performed by thermal embossing (engraved area ratio 18%) at 110° C. and a linear pressure of 1 Mpa. An SMS nonwoven fabric laminate having a layered structure was obtained. The physical properties of the obtained SMS nonwoven fabric laminate were measured by the methods described above. The results are shown in Tables 1 and 2.

(Comparative Example 12)
<Manufacture of spunbond nonwoven fabric (SB)>
A spunbonded nonwoven fabric (SB) was obtained in the same manner as in Example 1 except that only 100 parts by mass of a propylene homopolymer (PP) having an MFR of 60 g/10 min and a density of 0.910 g/cm3 was used.
<Manufacture of SMS nonwoven fabric laminate>
An SMS nonwoven fabric laminate having a three-layer structure was obtained in the same manner as in Comparative Example 11 except that the spunbonded nonwoven fabric (SB) was used. The physical properties of the obtained SMS nonwoven fabric laminate were measured by the methods described above. The results are shown in Tables 1 and 2.

In Tables 1 and 2, "SB" is a spunbonded nonwoven fabric, "MB" is a meltblown nonwoven fabric, "SMS" is a spunbonded nonwoven fabric/meltblown nonwoven fabric/spunbonded nonwoven fabric nonwoven fabric laminate, "PP" represents a propylene-based polymer, "PE" represents an ethylene-based polymer, and "wax" represents a wax. The blank column in the table indicates that the corresponding component is not contained.

As is clear from the results of Examples 1 and 2 in Table 1, a meltblown nonwoven fabric is formed by using three raw materials of a propylene/ethylene copolymer, a propylene/ethylene polymer wax, and a propylene homopolymer. In doing so, a non-woven fabric having a fine fiber diameter, good formation and low air permeability can be obtained.
The decrease in elongation of MB after electron beam irradiation is also suppressed, and when laminated with a spunbonded nonwoven fabric, as shown in Table 2, there is little damage due to heat embossing, and an SMS nonwoven fabric with good water pressure resistance is obtained. To be
Also, in Example 2 which is a five-layer laminated SMS non-woven fabric with a PE-based melt blow that is not easily deteriorated by an electron beam, a non-woven fabric having a high interlaminar peel strength is obtained.

On the other hand, as in Comparative Example 1, when only a propylene/ethylene copolymer and a propylene homopolymer are used to form a meltblown nonwoven fabric, the air permeability becomes high. It is considered that this is because fine fibers are difficult to be formed at the time of melting and discharging the resin, and a nonwoven fabric having a good texture cannot be obtained. Furthermore, when an SMS nonwoven fabric laminated body is formed using the obtained melt blown nonwoven fabric, it turns out that the water pressure resistance of a nonwoven fabric laminated body becomes low.
In Comparative Example 3 in which only a propylene/ethylene copolymer and a propylene-based polymer wax were used to form a meltblown nonwoven fabric, a nonwoven fabric with fine fibers and good texture could not be obtained, and the air permeability was high. Further, there was a tendency that stable spinning and web forming were difficult.
It can be seen that in Comparative Example 5 in which a meltblown nonwoven fabric was formed using a composition comprising a propylene homopolymer and an additive, the strength and elongation after electron beam irradiation were significantly reduced.

In Comparative Example 4, it can be seen that the water pressure resistance becomes low when a five-layer laminated SMS nonwoven fabric with PE-based melt blowing is used.
When only a propylene/ethylene copolymer having a relatively high propylene content of Comparative Examples 9 and 10 was used to form a meltblown nonwoven fabric, a nonwoven fabric having fine fibers and a good texture could not be obtained. The peel strength between layers when a five-layer laminated SMS nonwoven fabric is formed is reduced.
When placed on a three-layer laminated SMS non-woven fabric of the PE-based melt blown non-woven fabric and the spun bond non-woven fabric of Comparative Example 11, it is found that not only the peel strength between the layers is lowered but also the tensile strength is lowered.
When a meltblown nonwoven fabric is formed using only a propylene homopolymer as in Comparative Example 12, the air permeability is good, but the elongation in tension after electron beam irradiation is significantly reduced. Further, in a five-layer laminated SMS nonwoven fabric with PE-based melt blow, the peel strength between layers becomes low.

Claims (13)

A propylene/α-olefin copolymer,
A propylene homopolymer,
Ri Do from fibers consisting of propylene-based polymer composition having a weight average molecular weight; and a propylene-based wax is a 400-30000 (A),
20 parts by mass to 75 parts by mass of the propylene/α-olefin copolymer, 5 parts by mass to 30 parts by mass of the propylene homopolymer, and 100 parts by mass of the propylene-based polymer composition (A), A meltblown nonwoven fabric containing 20 parts by mass to 50 parts by mass of a propylene-based wax . The melt blown nonwoven fabric according to claim 1, wherein the propylene/α-olefin copolymer has a heat of fusion measured by a differential scanning calorimeter of less than 80 J/g. The propylene polymer composition (A) further comprises at least one stabilizer selected from the group consisting of an organic phosphorus compound, a hindered amine compound and a phenol compound. Melt blown non-woven fabric. The content of the organophosphorus compound is 0.001 based on 100 parts by mass of the total content of the propylene/α-olefin copolymer and the propylene homopolymer in the propylene polymer composition (A). Parts by mass to 3 parts by mass,
The amount of the hindered amine-based compound used is 0.001 part by mass based on 100 parts by mass of the total content of the propylene/α-olefin copolymer and the propylene homopolymer in the propylene-based polymer composition (A). Parts to 3 parts by mass,
The amount of the phenolic compound used is 0.001 part by mass based on 100 parts by mass of the total content of the propylene/α-olefin copolymer and the propylene homopolymer in the propylene polymer composition (A). Part to 3 parts by mass, the meltblown nonwoven fabric according to claim 3. A propylene-based polymer composition (B) different from the propylene-based polymer composition (A) on at least one surface of the meltblown nonwoven fabric according to any one of claims 1 to 4. A non-woven fabric laminate in which spun-bonded non-woven fabrics made of fibers are laminated. A continuous long-fiber nonwoven fabric made of fibers composed of an ethylene-based polymer composition (C) is laminated on at least one surface of the melt-blown nonwoven fabric according to any one of claims 1 to 4. Nonwoven laminate. A propylene-based polymer composition (B) different from the propylene-based polymer composition (A) on one surface of the melt blown nonwoven fabric according to any one of claims 1 to 4. A spunbonded nonwoven fabric made of fibers is laminated, and a continuous long-fiber nonwoven fabric made of fibers made of an ethylene-based polymer composition (C) is laminated on the other surface of the nonwoven fabric laminate. The non-woven fabric laminate according to claim 6 or 7, wherein the continuous long-fiber non-woven fabric made of fibers composed of the ethylene-based polymer composition (C) is a melt-blown non-woven fabric. The ethylene polymer composition (C) has an ethylene polymer (c-1) having a melt flow rate (MFR) of 10 g/10 min to 250 g/10 min and a weight average molecular weight (Mw) of 400 to 15000. Of the ethylene polymer wax (c-2), wherein the content of the ethylene polymer (c-1) with respect to the ethylene polymer wax (c-2) is in a mass ratio [(c-1). /(C-2)] is in the range of 90/10 to 10/90, and the nonwoven fabric laminate according to any one of claims 6 to 8. The propylene-based polymer composition (B) is propylene to polymer (b-1) 100 parts by weight, the ethylene polymer density of ^{0.93g / cm 3 ~0.98g / cm 3} (b The non-woven fabric laminate according to claim 5 or 7, which is a polymer composition containing 1 to 10 parts by mass of -2). The spunbonded non-woven fabric composed of the fibers composed of the propylene-based polymer composition (B) was aerated by a Frazier air permeability meter according to JIS L 1096 (2010) under the condition that the flow rate was 125 Pa and the pressure difference was 125 Pa. The nonwoven fabric laminate according to claim 10, having a degree of 500 cm ³ /cm ² /s or less. Medical melt containing the melt blown nonwoven fabric according to any one of claims 1 to 4, or the nonwoven fabric laminate according to any one of claims 5 to 11. A drape containing the melt blown nonwoven fabric according to any one of claims 1 to 4, or the nonwoven fabric laminate according to any one of claims 5 to 11.