TW201428033A - Moisture vapor permeable film and method for manufacturing same - Google Patents

Abstract

Provided is a moisture vapor permeable film which has excellent liquid permeability resistance while maintaining air permeability, moisture vapor permeability, mechanical strength and utility. This moisture vapor permeable film is composed of a resin composition which comprises a polyethylene resin composition (A) that includes a polyethylene resin with a melting peak temperature of 130 to 150 DEG C and a density of 0.940 to 0.970 g/cm3, an inorganic filler (B) and a styrene-based elastomer (C), 1 to 20 parts by mass of the styrene-based elastomer (C) being added with respect to 100 parts by mass of the total of the polyethylene resin composition (A) and the inorganic filler (B). Further, this moisture vapor permeable film has a bleeding area of less than 5%.

Description

Moisture permeable film and method of producing the same

The present invention relates to a moisture permeable film and a method for producing the same, and more particularly to a moisture permeable film which is excellent in air permeability, mechanical strength, and practicality, and a method for producing the same.

It is known that a moisture-permeable film composed of a resin composition containing a polyolefin-based resin and an inorganic filler is interfacially peeled off between the resin and the inorganic filler by stretching, and forms a plurality of pores (micropores) to impart moisture permeability. Ventilation. Since the film has a plurality of pores forming a communication hole therein, even if it has a high gas permeability and a moisture permeability, liquid penetration is not caused. This feature is used in a wide range of products such as disposable diapers, sanitary materials for women, or breathable films, disposable chemical protective clothing, waterproof sheets and battery separators.

Conventionally, the back sheet of a disposable diaper or a physiological article is almost white and has no grain, but in recent years, it has been gradually recognized that the design and the implementation of various patterns are gradually increasing. On the other hand, such a film is evolving toward thinning and low basis weighting of thin films for the purpose of reducing cost and light weight. Accordingly, if the film is thinned and the basis weight is reduced, there is a tendency for the film to move toward the machine direction (hereinafter referred to as "MD"), and the printing pitch is shifted or deformed due to the running tension of the printing machine. Problems such as deterioration of physical properties.

In view of the above problems, a linear low-density polyethylene which is conventionally used is changed to a polyolefin having a high tensile modulus of elasticity such as high-density polyethylene or polypropylene, and A method of making the film difficult to extend by increasing the stretching ratio, but causing a feeling of texture and a decrease in texture. In addition, if a large amount of high-density polyethylene having high crystallinity is contained, there is a possibility that stretching unevenness often occurs due to necking, and leakage and liquid permeability resistance are lowered due to formation of a large pore ‧ pinhole .

Therefore, in order to obtain a film which is excellent in strength, air permeability, moisture permeability, texture, and texture, and which does not leak, it is necessary to use a high-density polyethylene or polypropylene to make the texture feel excellent. Formulations and manufacturing methods that result in uneven extension and can form homogeneous pores.

As a modification of high-density polyethylene, an elastomer such as an olefin-based elastomer is blended, and the elastomer is partially compatible with high-density polyethylene, and the degree of crystallization is lowered and the modulus of elasticity is modified. For example, a porous film excellent in moisture permeability, flexibility, and stretchability disclosed in Japanese Patent No. 3420363 (Patent Document 1) is used in a specific ethylene-(α-olefin) copolymer having a low density and a low melting point. It is produced by a resin composition containing a specific thermoplastic elastomer and an inorganic filler.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent No. 3420363

However, it is often the case that the effect cannot be exerted due to the type and amount of the elastomer. Further, the porous film of Patent Document 1 focuses on moisture permeability, flexibility, and stretchability, and uses a low-density, low-melting ethylene-(α-olefin) copolymer as a substrate. Therefore, the liquid permeability is low, and there is a tendency to leak as a disposable diaper or a physiological product, and due to the strength. And heat resistance is poor, so it is impossible to use it in moisture-permeable waterproof sheets, battery separators, disposable chemical protective clothing, and the like.

The present invention has been made in view of the above problems, and it is an object of the present invention to provide a moisture-permeable film which is excellent in moisture permeability and which is excellent in liquid permeability resistance and which is excellent in strength and heat resistance.

In order to solve the above problems, the inventors have intensively studied and found that a polyethylene resin composition containing a high-density polyethylene resin having a high melting peak temperature and a high density is blended to improve heat resistance and strength, and is moderately compatible. The styrene-based elastomer can obtain a moisture-permeable film which can achieve both liquid permeability resistance and no leakage even if it maintains moisture permeability and air permeability.

The moisture permeable film of the present invention obtained according to the above findings is composed of a polyethylene resin composition (A) containing a polyethylene resin having a melting peak temperature of 130 to 150 ° C and a density of 0.940 to 0.970 g/cm ³ , and inorganic The filler (B) and the styrene-based elastomer (C); and the styrene-based elastomer is added to 100 parts by mass of the total of the polyethylene resin composition (A) and the inorganic filler (B). C) 1 to 20 parts by mass of the resin composition; wherein the bleed area is less than 5%.

The polyethylene resin composition (A) and the inorganic filler (B) of the moisture-permeable film of the present invention are preferably (A): (B) = 60 to 20 parts by mass: 40 to 80 parts by mass. Blending.

The polyethylene resin composition (A) preferably contains a high-density polyethylene (a) having a density of 0.940 to 0.970 g/cm ³ and a linear low-density polyethylene (b) having a density of 0.915 to 0.939 g/cm ³ , And low density polyethylene (c) having a density of 0.910 to 0.930 g/cm ³ ; and, according to the above (a): (b): (c) = 5 to 40% by mass: 50 to 93% by mass: 2 to 10 by mass The proportion of % is blended.

Further, the styrene-based elastomer (C) of the moisture-permeable film of the present invention is a styrene-olefin-styrene block copolymer, and preferably the styrene component is contained in an amount of 10 to 40% by mass.

Further, the basis weight (mass per unit area) of the moisture-permeable film of the present invention is preferably 10 to 50 g/m ² .

Further, the moisture permeability of the moisture permeable film of the present invention is preferably 1,000 to 15,000 g / (m ² ‧ 24 h).

Further, the moisture permeability of the moisture permeable film of the present invention is preferably from 100 to 10,000 sec / 100 mL.

Further, the moisture permeable film of the present invention preferably has a mechanical direction (MD) tensile breaking strength of 500 gf / 25 mm or more.

The moisture-permeable film of the present invention has excellent moisture permeability and air permeability, and is excellent in liquid permeation resistance (liquid barrier property) and can satisfy the opposite characteristics. Therefore, when used in disposable diapers and physiological products, there is no possibility of leakage, which is quite suitable for use. Further, since it is mechanically strong even if it is very lightweight, it has heat resistance and has practical advantages, and thus can be applied to various uses.

Fig. 1 is an explanatory diagram of a method of evaluating the bleed area.

Hereinafter, the moisture permeable film of the present invention will be described in detail.

The moisture-permeable film of the present invention is composed of a polyethylene resin composition (A) containing a polyethylene resin having a melting peak temperature of 130 to 150 ° C and a density of 0.940 to 0.970 g/cm ³ , an inorganic filler (B), and The styrene-based elastomer (C); and the styrene-based elastomer (C) is added in an amount of 1 to 20 parts by mass based on 100 parts by mass of the total of the polyethylene resin composition (A) and the inorganic filler (B). The composition of the resin composition.

It has a liquid permeation resistance of less than 5% of the permeation area, and has a high moisture permeability of a moisture permeability of 1,000 to 15,000 g / (m ² ‧24 h), and has a high air permeability of 100 to 10,000 seconds / 100 mL. Ventilation. Further, the basis weight (mass per unit area) is a light weight of 10 to 50 g/m ² and has a tensile strength at a mechanical direction (MD) of 500 gf/25 mm or more and heat resistance.

(component of moisture permeable film)

The polyethylene resin composition (A) which is a raw material of the moisture-permeable film of the present invention contains a high-density polyethylene (a) having a melting peak temperature of 130 to 150 ° C and a density of 0.940 to 0.970 g/cm ³ . The strength and heat resistance can be improved by using the high-density polyethylene (a).

The polyethylene resin composition (A) used in the present invention is preferably blended with the linear low-density polyethylene (b) having moderate flexibility and strength in the above-mentioned high-density polyethylene (a), and is also formed by lifting. The low-density polyethylene (c) produced by the high-pressure polymerization method is added for workability.

The high-density polyethylene (a), the linear low-density polyethylene (b), and the low-density polyethylene (c) may, for example, be an ethylene monomer; and ethylene-propylene or ethylene-(1-butene). , ethylene-(α-olefin) copolymers such as ethylene-(1-hexene), ethylene-(4-methyl-1-pentene) and ethylene-(1-octene); propylene monomerization in polypropylene And propylene-ethylene copolymer and the like. These are carried out by using a single active point catalyst such as a Ziegler type or a Philips type or a single active point catalyst such as a metallocene system, and an oxidizing agent, a peroxide or the like as a polymerization initiator.

The density of the high-density polyethylene (a) is 0.940 to 0.970 g/cm ³ , preferably 0.945 to 0.965 g/cm ³ as described above. Further, the density of the linear low-density polyethylene (b) is 0.915 to 0.939 g/cm ³ , and the density of the low-density polyethylene (c) is preferably 0.910 to 0.930 g/cm ³ .

The melt mass flow rate (hereinafter referred to as "MFR". 190 ° C, 2.16 kgf) is preferably 0.1 to 20 g/10 min, more preferably 0.5 to 5 g/10 min. By setting the MFR to 0.1 g/10 min or more, the moldability of the film can be sufficiently maintained, and sufficient strength can be obtained by setting it to 20 g/10 min or less.

The high-density polyethylene (a) has a melting point of 130 to 150 ° C, preferably 130 to 140 ° C. Further, the linear low-density polyethylene (b) has a melting point of 100 to 130 ° C, and the low-density polyethylene (c) has a melting point of 100 to 120 ° C.

Specifically, the polyethylene resin composition (A) preferably contains a high-density polyethylene (a) having a density of 0.940 to 0.970 g/cm ³ and a linear low-density polyethylene having a density of 0.915 to 0.939 g/cm ³ ( b), and a low-density polyethylene (c) having a density of 0.910 to 0.930 g/cm ³ and set as the above (a): (b): (c) = 5 to 40% by mass: 50 to 93% by mass: 2 ~10% by mass of blending.

Examples of the inorganic filler (B) include fine particles such as calcium carbonate, calcium sulfate, barium carbonate, barium sulfate, and titanium oxide. Among them, calcium carbonate and barium sulfate are more suitable. The average particle diameter is preferably 0.1 to 10 μm, more preferably 0.3 to 5 μm, and particularly preferably 0.5 to 3 μm. When the average particle diameter is 0.1 μm or more, dispersion or secondary aggregation of the inorganic filler (B) can be suppressed, and since it can be uniformly dispersed, it is preferable. On the other hand, when the average particle diameter is 10 μm or less, the generation of large pores can be suppressed when thinning, and the crucible can have sufficient strength and liquid permeation resistance. Further, in order to enhance the dispersibility and the miscibility between the resins, it is preferred to coat the fine particles with a fatty acid, a fatty acid ester or the like in advance so that the surface of the fine particles is easily kept compatible with the resin.

The blending ratio (A) of the above polyethylene resin composition (A) and the inorganic filler (B): (B), preferably (A): (B) = 60 to 20 parts by mass: 40 to 80 by mass Share.

More preferred (A): (B) = 55 to 25 parts by mass: 45 to 75 parts by mass, and particularly preferably 50 to 30 parts by mass: 50 to 70 parts by mass. When the blending ratio (A): (B) is within the above range, moisture permeability, air permeability, and liquid permeation resistance can be sufficiently achieved.

Examples of the styrene-based elastomer (C) include a styrene-olefin system (SEP, SEBC, etc.), a styrene-olefin-styrene system (SEPS, SEBS, etc.), and a styrene-diene system (SIS). , SBS, etc.), a styrene block elastomer of a hydrogenated styrene-diene system (HSIS, HSBR, etc.). Among them, a styrene-olefin-styrene block copolymer is preferred from the viewpoint of dispersibility between high-density polyethylene and linear low-density polyethylene.

"HYBRAR" and "SEPTON" manufactured by KURARAY Co., Ltd., "TUFTEC" and "TUFPRENE" manufactured by Asahi Kasei Chemicals Co., Ltd.; "DYJARON" manufactured by JSR Co., Ltd.; "Kraton Performance Polymers Inc." KRATON G", "KRATON D"; "OnFlex S" manufactured by PolyOne Corporation.

The selection criteria of the styrene-based elastomer (C) is preferably such that it has a moderate compatibility with the polyethylene resin composition (A). When the compatibility between the polyethylene resin composition (A) and the styrene elastomer (C) is too low, the styrene elastomer (C) becomes a layer, a cylinder, or a large region (dispersed phase). The structure, which hinders the film formation and extension, does not solve the problem that the invention wants to solve. On the other hand, if the compatibility between the polyethylene resin composition (A) and the styrene elastomer (C) is too high, the polyethylene resin composition (A) is caused by the styrene elastomer (C). The degree of crystallization and the modulus of elasticity are lowered, resulting in a significant decrease in the tensile strength of the film.

The styrene component in the styrene-based elastomer (C) is preferably from 10 to 40% by mass, more preferably from 20 to 40% by mass, from the viewpoint of appropriate compatibility.

Furthermore, in order to make the polyethylene resin composition (A) and the styrene elastomer (C) The dispersion can be uniformly kneaded, preferably in the molding temperature ‧ shear rate range of the resin composition, and the viscosity of the styrene elastomer (C) is the same as the viscosity of the polyethylene resin composition (A). The viscosity of the styrene-based elastomer (C) is preferably in the range of 0.1 to 10 g/10 min (230 ° C, 2.16 kgf) in terms of MFR.

As described above, the content of the styrene-based elastomer (C) is 1 to 20 parts by mass, preferably 2, based on 100 parts by mass of the total of the polyethylene resin composition (A) and the inorganic filler (B). ~15 parts by mass. The blending amount is important, and when the content of the styrene elastomer (C) is at least 1 part by mass, the contradiction characteristics of moisture permeability, air permeability, and liquid permeation resistance can be achieved. On the other hand, the mechanical strength can be sufficiently maintained by setting it to 20 parts by mass or less.

Other additives may also be added as needed. Specific examples thereof include higher fatty acids, higher fatty acid esters, higher fatty acid decylamines, metal soaps, higher alcohols, petrolatum, paraffin waxes, glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, Propylene glycol fatty acid ester, castor oil, hydrogenated castor oil, hardened castor oil, dehydrated castor oils, aromatic esters, aromatic guanamines, polyethers, polyesters and other low molecular weight polymers (oligomers), etc. A plasticizer; a slip agent; an additive that allows the inorganic filler (B) to be well dispersed. The hardened castor oil is preferably used in the above additive, and the blending amount of the hardened castor oil is preferably 100% by mass based on the total of the above (A), (B) and (C), preferably 1 to 5% by mass, more preferably 3 to 3 4% by mass.

Further, in addition to the above additives, in addition to the purpose of use, a resin composition may be added or coated: a compatibilizer, a processing aid, an antioxidant, a thermal stabilizer, a photo-stabilizer, an ultraviolet absorber, Anti-caking agent, anti-fogging agent, delustering agent, surfactant, antibacterial agent, deodorant, antistatic agent, water repellent, oil-repellent agent, radiation shielding agent, coloring agent, and pigment. The thermal stabilizer in the above additive is more suitable for use, The blending amount of the heat stabilizer is preferably from 0.1 to 1% by mass based on 100% by mass of the total of the above (A), (B) and (C).

(Method for producing a moisture permeable film)

The moisture permeable film of the present invention is obtained by melt-kneading the above resin composition, and then performing extrusion molding by a T-die method or an inflation method, and performing at least once in a mechanical direction (MD) at a temperature ranging from 15 to 100 °C. Extended and manufactured.

Specifically, the polyethylene resin composition (A), the inorganic filler (B), and the styrene elastomer (C) are subjected to a mixer such as a rotary drum, a high-speed mixer, or a Hansui mixer. Mixed ‧ dispersed Thereafter, melt kneading is performed using a uniaxial or biaxial kneader or an extruder to form granules. Alternatively, the granules may be obtained by directly feeding the raw materials into a funnel or a side feeder without using a mixer. At this time, melt-kneading is carried out depending on the melting point of the polyethylene resin composition (A), preferably from the melting point of +30 ° C to the decomposition temperature of the resin composition. Next, the pellets are melted and formed into a film by a known molding method using an extrusion molding machine equipped with a T-die and an inflation molding machine equipped with a circular die. Depending on the case, it is also possible to form a film directly without granulation.

The unstretched film of the film formed is stretched at least once in the machine direction (MD) by a stretching method such as a known roll method, a tenter method, or a stretching method. The temperature of the stretching rolls is 15 to 100 ° C, and the stretching ratio is preferably 1.5 to 5.0 times in total.

The heat shrinkage strategy of the moisture permeable film can also be heat set after extension. Here, "thermal fixing" means that heat is applied to the moisture permeable film in advance after the stretching step, and the moisture permeable film is thermally contracted to suppress shrinkage of the moisture permeable film. In the heat-fixing method, the stretched moisture-permeable film is heated by a heated roll (annealing roll), and the elongation ratio (ratio of the take-up side roll speed/winding-side roll speed) is made negative. square law. Here, if the heat setting temperature is too low, the heat shrinkage rate of the moisture permeable film becomes large, and if the heat setting temperature is too high, the moisture permeable film adheres and is wound around the roll to cause a failure. If the above matters are considered, the heat setting temperature is preferably 70 to 120 °C.

Further, if the negative elongation ratio is too small, the heat fixation cannot be sufficiently performed; if it is too large, the film is loosened between the rolls, which causes a production failure. Therefore, it is more suitable for the system -10 ~ -20%. Further, the rolls are preferably made of a metal having a large heat capacity and a chrome-plated surface.

(physical properties of moisture permeable film)

As described above, the moisture permeable film has a bleeding area of less than 5%, preferably less than 2%. The bleed area was measured in accordance with the method described later.

The oozing area is less than 5%, which means that it has sufficient liquid permeability resistance. When the moisture permeable film of the present invention is used for a back sheet of a disposable diaper or a female physiological product, it is necessary to prevent water, urine or menstrual blood from leaking and oozing out of the back surface of the moisture permeable film, and liquid permeation resistance becomes important. Evaluation project. By adding the styrene-based elastomer (C) to the polyethylene resin composition (A) and the inorganic filler (B), the bleed area is less than 5%.

As described above, the basis weight of the moisture-permeable film is preferably 10 to 50 g/m ² , more preferably 15 to 40 g/m ² , and particularly preferably 15 to 30 g/m ² . By having the basis weight within the above range, it is possible to sufficiently achieve both air permeability, comfort, and liquid permeability resistance. The method of measuring the basis weight will be described later.

As described above, the moisture permeability of the moisture permeable film is preferably 1,000 to 15,000 g/(m ² ‧24 h), more preferably 2,000 to 10,000 g/(m ² ‧24 h), and particularly preferably 3,000 to 10,000 g/( m ² ‧24h). It is suggested that water permeability and liquid permeability resistance are obtained by the moisture permeability of 15,000 g/(m ² ‧24 h) or less. Further, it is suggested that the pores have sufficient connectivity by a moisture permeability of 1,000 g/(m ² ‧24 h) or more, and are comfortable even when worn. The method for measuring the moisture permeability will be described later.

As described above, the air permeability of the moisture permeable film is preferably 100 to 10,000 sec / 100 mL, more preferably 200 to 3,000 sec / 100 mL, and particularly preferably 300 to 2,000 sec / 100 mL. It is suggested that the pores have sufficient connectivity by having a gas permeability of 10,000 sec/100 mL or less. Further, by having a gas permeability of 100 sec/100 mL or more, the water repellency and liquid permeation resistance can be sufficiently obtained. The method of measuring the gas permeability will be described later.

As described above, the strength of the moisture permeable film is preferably 500 gf / 25 mm or more in the machine direction (MD), and more preferably 700 gf / 25 mm or more.

By achieving 500 gf/25 mm or more, sufficient mechanical strength can be ensured. Further, the upper limit is not particularly limited, but in consideration of the elongation, it is preferably 3000 gf/25 mm or less.

The moisture permeable film of the present invention can also form a plurality of laminated film laminates. Further, the moisture permeable film of the present invention may be laminated with another film to form a film laminate. Regardless of the laminated body, it is preferred that the entire laminated body has liquid permeation resistance of less than 5% of the above-mentioned bleeding area and moisture permeability of 1,000 to 15,000 g/(m ² ‧24 h).

[Examples]

Hereinafter, the embodiments of the present invention will be described, but the present invention is not limited to the above. The materials used in the examples and comparative examples are shown in Table 1, and the blending amounts of the examples and comparative examples are shown in Table 2.

The materials of Examples 1 and 2 and Comparative Examples 1 to 3 described in Table 1 above were mixed for 5 minutes using a Hansui mixer, and then set to 180 ° C. The 80 mm co-rotating twin-screw extruder was melt-kneaded and temporarily pelletized.

Thereafter, using the back layer of the watch 65mm single-axis extruder, intermediate layer 2 sets of 90mm single-axis extruders, A 300 mm inflatable die was obtained, and an unstretched film was obtained under the following conditions.

Barrel temperature: 150 ° C (C1), 170 ° C (C2), 190 ° C (after C3)

Conduit temperature: 190 ° C

Inflatable mold temperature: 190 ° C

Pulling speed: 46m/min

Unstretched film thickness: 50~60μm

Next, the films were longitudinally stretched by a roll longitudinal stretching machine under the following conditions.

Extension temperature: 25~70°C, extension ratio (total): 2.60 times

Example 1 and Example 2 are blending ratios of the hardened castor oil and the heat stabilizer which change the additive. Further, in Comparative Examples 1 to 3, the styrene-based elastomer was not blended, and Comparative Example 1 and Comparative Example 2 were changed in elongation temperature.

The moisture-permeable films of Examples 1 and 2 and Comparative Examples 1 to 3 produced were evaluated in accordance with the following methods. The evaluation results of the examples and comparative examples are shown in Table 3.

[Evaluation and measurement method] (1) Hand feeling ‧ texture judgment

The moisture permeability film is judged by the touch.

◎: It is rich in softness and touch.

○: rich in softness

△: lack of softness

×: lack of softness, rough touch

(2) basis weight (g/m ² )

After the sample [MD: 250 mm, TD: 200 mm] was taken from the moisture permeable film, the weight measurement (g) was carried out, and the value was multiplied by 20 times to obtain the basis weight.

(3) Air permeability (seconds / 100mL)

According to the method specified in JIS P8117 (GURLEY test machine method), 10 places were randomly taken using a Wang-type gas permeability measuring machine, and the average value was calculated.

(4) Moisture permeability (g/(m ² ‧24h))

The moisture permeability is in accordance with JIS Z0208 (cup method). The measurement was carried out under the conditions of a temperature of 40 ° C, a relative humidity of 90%, and a calcium chloride content of 15 g. Take 2 randomly and calculate the average.

(5) Exudation area (liquid permeability resistance)

The preparation of the test liquid and the measurement of the exfoliation area were carried out in a constant temperature humidity chamber at a temperature of 23 ° C and a humidity control of 50% relative humidity.

In the test liquid, 99.0 parts by mass of distilled water, 1.0 part by mass of a cationic surfactant (Nippon Oil Co., Ltd., ELEGAN® 263-40), and 0.30 parts by weight of a red pigment No. 40 (Allura Red, manufactured by Wako Pure Chemical Industries, Ltd.) were stirred. Hours until homogeneously dissolved and dispersed.

The evaluation method of the bleed area is as shown in Fig. 1. On a filter paper (FILTER PAPER No. 2 diameter: 70 mm manufactured by ADVANTEC Co., Ltd.), a moisture permeable film cut into 100 mm × 100 mm squares was cut into 70 mm × 70 mm squares. The moisture-retaining sheets were overlapped, and 2.0 mL of the test liquid was quietly dropped on the center portion of the moisture-retaining sheet. After the dropping, the resin sheet (diameter: 60 mm × thickness: 5 mm) was placed on the above-mentioned moisture-retaining sheet, and a weight of 2 kg was placed thereon and left for 30 minutes. Exuding the above test from the back surface of the moisture permeable film In the test liquid, the area in which the filter paper was colored (bleeded out) to red was measured, and the ratio of the area in the entire filter paper to be pressurized was calculated, and the following evaluation was performed.

◎: The seepage area is less than 2%

○: The oozing area is more than 2% and less than 5%

△: The oozing area is more than 5% and less than 15%

×: The oozing area is over 15%

(6) Tensile breaking strength in mechanical direction (MD) (gf/25mm)

According to JIS K7127. The test was performed three times according to the test width of 25 mm and the tensile speed of 200 m/min, and the average value was obtained.

(7) ASTM F1671 virus protection test

According to ASTM F1671-07B, Bacteriophage Phi-X174 was used for the test virus and Escherichia coli b was used for the host bacteria. Further, a virus protection test was carried out using a test liquid whose surface tension was adjusted to 42 mN/m. The test was carried out at the KAKEN TEST CENTER Osaka Business Center.

When three measurements were performed, if the number of phage indicating the amount of virus penetration (PFU/mL) was less than 1, the virus penetration was considered to be "qualified".

The above-mentioned bleed area which is a liquid permeability resistance index has a correlation with the virus protective property obtained by the above virus protection test, and the moisture permeable film of the present invention has good liquid permeability resistance (inhibition of test liquid oozing) ), it also has good virus protection properties (inhibition of virus penetration).

In the first embodiment and the second embodiment, the bleed area of the liquid permeability resistance index was less than 2%, which was acceptable, but the comparative examples 1 and 2 could not reach less than 5%, and belonged to "△". Comparative Example 3 is 15% or more and belongs to "X". Moreover, the virus protection test of Comparative Example 2 failed. Examples 1 and 2 were extensible, and the texture and texture were also good. It is also excellent in air permeability and moisture permeability. As described above, it is particularly excellent in liquid permeability resistance, and the ASTM F1671 virus protection test is acceptable.

Further, in Comparative Examples 1 and 2 in which the styrene-based elastomer (C) was not added, when the polyethylene resin/inorganic filler film was stretched, a unique necking ‧ extension unevenness occurred and the surface state was poor. The ASTM F1671 virus protection test of Comparative Example 2 was unsatisfactory because of uneven stretching or liquid leakage from fine pinholes. In addition, since the high-density polyethylene resin was not added in Comparative Example 3, both the hand feeling and the tensile strength were good, but the liquid permeability resistance was very poor compared with the other, and it was evaluated as "x". Therefore, Comparative Example 3 did not carry out the ASTM F1671 virus protection test.

(industrial availability)

The moisture-permeable film of the present invention is very lightweight, and maintains air permeability, moisture permeability, mechanical strength, and practicality, and has excellent liquid permeability resistance and protection. Therefore, it can be applied to: disposable diapers, sanitary materials for women and other sanitary materials; breathable film, waterproof A wide range of products such as sheet, disposable chemical protective clothing, overalls, pullovers, jackets, medical clothes, masks, covers, curtains, sheets and scarves, and battery separators.

Claims (11)

A moisture permeable film comprising a polyethylene resin composition (A), an inorganic filler (B), and a benzene comprising a polyethylene resin having a melting peak temperature of 130 to 150 ° C and a density of 0.940 to 0.970 g/cm ³ ; The ethylene-based elastomer (C); and the styrene-based elastomer (C) is added in an amount of 1 to 20 parts by mass based on 100 parts by mass of the total of the polyethylene resin composition (A) and the inorganic filler (B). The composition of the resin composition; wherein the bleed area is less than 5%. The moisture permeable film according to the first aspect of the invention, wherein the polyethylene resin composition (A) and the inorganic filler (B) are (A): (B) = 60 to 20 parts by mass: 40~ A ratio of 80 parts by mass was blended. The moisture permeable film according to claim 1 or 2, wherein the polyethylene resin composition (A) comprises a high density polyethylene (a) having a density of 0.940 to 0.970 g/cm ³ and a density of 0.915 to 0.939. a linear low density polyethylene (b) of g/cm ³ and a low density polyethylene (c) having a density of 0.910 to 0.930 g/cm ³ ; and, according to the above (a): (b): (c) = 5 ~40% by mass: 50 to 93% by mass: 2 to 10% by mass in proportion. The moisture permeable film of the first aspect of the invention, wherein the styrene elastomer (C) is a styrene-olefin-styrene block copolymer and contains 10 to 40% by mass of a styrene component. The moisture permeable film of claim 1, wherein the basis weight (mass per unit area) is 10 to 50 g/m ² . The moisture permeable film of claim 1, wherein the moisture permeability is 1,000 to 15,000 g/(m ² ‧24 h). For example, the moisture permeable film of claim 1 of the patent scope, wherein the air permeability is 100 to 10,000 Seconds / 100mL. The moisture permeable film of claim 1, wherein the tensile strength at a mechanical direction (MD) is 500 gf/25 mm or more. A thin film laminated body obtained by laminating a moisture permeable film according to any one of claims 1 to 8 or laminating the moisture permeable film and another film. A method for producing a moisture-permeable film, which is a method for producing a moisture-permeable film according to any one of claims 1 to 8, wherein the resin composition containing the component (A) (B) (C) is melted. After the kneading, the film is formed by extrusion using a T-die method or an inflation method, and then stretched at least once in the mechanical direction (MD) at a temperature of 15 to 100 ° C. A clothing item selected from the group consisting of a pull-up shirt, a jacket, a overalls, a protective garment, and a surgical garment, a mask, a cover, a curtain, a bed sheet, and a scarf using the film laminate of claim 9.