JPH0948868A - Antibacterial porous film and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an antimicrobial porous film which has enlarged areas contacting the antimicrobial agent to air and can reveal excellent antimicrobial properties with reduced doses by drawing a film or a sheet made of a composition of a polyolefin resin, an antimicrobial agent and a filler. SOLUTION: A resin composition containing (A) a polyolefin resin such as polyethylene, polypropylene and the like, preferably in an amount of 100 pts.wt., (B) an antimicrobial agent, preferably in an amount of 0.2-5 pts.wt., (C) a filter, preferably calcium carbonate or barium sulfate, preferably in an amount of 5-200 pts.wt., is processed to a film or sheet, then the film or sheet is drawn. The resultant film has a porosity of >=50%, particularly 60-90%, an air permeability of preferably <=1,000sec/100cc and the hydraulic pressure resistance, preferably >=1,000mmHg. This film is obtained by melt forming a composition containing the component A and the component B into a film or sheet and drawing the sheet or film mono- or biaxially.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antibacterial porous film and a method for producing the same, and more particularly to an antibacterial porous film having porosity and exhibiting antibacterial properties by blending a small amount of an antibacterial agent, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, antibacterial films have been used for applications such as MRSA (nosocomial infection) countermeasure films, aprons, clothes sheets and protective clothes.

This antibacterial film is generally prepared by dispersing and compounding an antibacterial agent in the film.

[0004]

However, the above-mentioned conventional antibacterial film has a drawback that it cannot exhibit sufficient antibacterial properties unless a large amount of antibacterial agent is added.

Therefore, the object of the present invention is to improve the problems of the conventional antibacterial film and to make it porous so that the contact area between the antibacterial agent and the air is increased, and the addition of a small amount of the antibacterial agent is sufficient. An object is to provide an antibacterial porous film capable of exhibiting antibacterial properties.

[0006]

In order to solve the above-mentioned problems, the present invention provides an antibacterial porous film obtained by stretching a film or sheet of a resin composition containing a polyolefin resin, an antibacterial agent and a filler. It is provided.

The present invention also provides, as a method for producing the antibacterial porous film, a polyolefin resin, an antibacterial agent,
The present invention also provides a method for producing an antibacterial porous film, which comprises a step of melt-molding a resin composition containing a filler into a film or sheet, and then stretching.

The antibacterial porous film of the present invention and the method for producing the same will be described below in detail.

The antibacterial porous film of the present invention comprises a resin composition containing a polyolefin resin, an antibacterial agent and a filler as essential components. The polyolefin resin, which is an essential component of this resin composition, is a homopolymer of α-olefin, a copolymer composed of two or more α-olefins,
Examples thereof include a copolymer of α-olefin and a monomer copolymerizable with the α-olefin, or a mixture of these homopolymers and copolymers. As an α-olefin,
For example, ethylene, propylene, butene, 4-methyl-
1-pentene and the like. Examples of the monomer copolymerizable with the α-olefin include vinyl acetate, acrylic acid, methacrylic acid and the like. This polyolefin resin has an α-olefin content of 70 mol%.
That's all. Specific examples of these polyolefin resins include polyethylene, polypropylene, polybutene, poly-4-methyl-1-pentene, and random or block copolymers containing these as main components, ethylene-vinyl acetate copolymers, ethylene-acrylic acid. Examples thereof include copolymers and ethylene-methacrylic acid copolymers.

In the present invention, the polyolefin resin has moldability in the manufacturing process of the antibacterial porous film,
From the viewpoint of good molding properties such as high strength and tear strength, the MFR is preferably 0.01 to 15 g / 10 minutes, particularly preferably 0.1 to 8 g / 10 minutes.

In the present invention, as the antibacterial agent which is an essential component of the resin composition, both inorganic antibacterial agents and organic antibacterial agents can be used as long as they have the required antibacterial properties. , Antibacterial activity, safety, heat resistance, weather resistance,
It is appropriately selected depending on the required properties such as water resistance, chemical resistance, and appearance.

Examples of the inorganic antibacterial agents include antibacterial agents such as silver, copper and zinc in the skeleton structure of an inorganic carrier such as zeolite, zirconium phosphate, hydroxyapatite, phosphate glass and phosphate ceramics. An example is a form in which a sex ion is introduced. As a specific example of this inorganic antibacterial agent, Zeomic manufactured by Sinanen Zeomic Co., Ltd.
Bactekiller manufactured by Kanebo Co., Ltd., Novalon manufactured by Toagosei Co., Ltd., Ava Cider manufactured by Sangi Co., Ltd., Ion Viewer manufactured by Ishizuka Glass Co., Ltd., Amen Top manufactured by Matsushita Electric Industrial Co., Ltd. Examples thereof include Silver Ace manufactured by Rasa Kogyo Co., Ltd. and Lassap manufactured by Rasa Kogyo.

Examples of organic antibacterial agents include 2-octyl-4-isothiazolin-3-one, 10,10'-
Oxybisphenoxyarsine, 2- (4-thiazolyl) -benzimidazole, N- (fluorodichloromethylthio) -phthalimide, 2-methylcarbonylaminobenzimidazole, 2,3,5,6-tetrachloro-4- (methylthio) -Phthalimide, trimethoxysilyl-propyrioctadecyl ammonium chloride,
2-N-octyl-4-isothiazolin-3-one, bis (2-pyridylthio-1-oxide) zinc and the like can be mentioned. Specific examples of these organic antibacterial agents include Amorden SK-950 and SK-30W manufactured by Daiwa Chemical Industry Co., Ltd.
Morton Thiokol's Vinadine, Merck's Theabendazole, Bayer's Breventol A-
3, Melgar BCM made by Riedel de Haan, Dencil S3 made by ICR, Biosil made by Dow Corning, Skene M8 made by Rohm and Haas,
Examples include ZPT manufactured by Olin Japan.

Among these antibacterial agents, those in which antibacterial ions such as silver, copper and zinc are introduced into an inorganic carrier are preferable because of excellent antibacterial durability, heat stability and safety. In particular, those containing silver ions as antibacterial ions are preferable because they have excellent antibacterial properties.

The content of the antibacterial agent in the resin composition used in the present invention is 0.2 to 5 parts by weight, preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the polyolefin resin. Is.

In the present invention, the filler used as a component of the resin composition is not particularly limited, and may be either an inorganic filler or an organic filler, or a combination of both. Specific examples of this filler include inorganic earth fillers such as alkaline earth metals, oxides, hydroxides, carbonates, sulfates and silicates of Group III elements of the periodic table. Examples of the organic filler include cellulose powder such as wood powder and pulp, and crosslinked powder such as silicone and phenol. These may be used alone or in combination of two or more. Among these, calcium carbonate, barium sulfate and the like are preferable in consideration of cost and stability of quality.

The particle size of this filler is usually 0.1 to 8 μm.
It is about m, and the porosity is increased with a small blending amount, and preferably about 0.5 to 5 μm.

If necessary, a conventional compounding agent such as wax, heat stabilizer, weathering stabilizer, lubricant, antistatic agent, etc. may be added to the resin composition as long as the object of the present invention is not impaired. May be.

The mixing ratio of the polyolefin resin, the antibacterial agent and the filler in the resin composition is preferably 0.2 to 100 parts by weight of the polyolefin resin.
5 parts by weight and 20 to 100 parts by weight of the filler, and more preferably 0.5 to 2 parts by weight of the antibacterial agent and 5 to 200 parts by weight of the filler with respect to 100 parts by weight of the polyolefin resin. Further, if the blending ratio of the filler is too small compared to the above range, it becomes difficult to obtain an antibacterial porous film by stretching treatment, and if the blending ratio is too large, the kneadability at the time of melt-molding the resin composition into a film or sheet. , Dispersibility, film or sheet moldability is poor, and further, stretchability in molding of the antibacterial porous film by stretching treatment of the film or sheet is poor.

Further, the resin composition is prepared by using the above-mentioned polyolefin resin, antibacterial agent and filler, and various kinds of compounding agents which are compounded as necessary, in a Henschel mixer, a tumbler type mixer, a V type mixer or the like. It can be performed according to the method of mixing using a conventional mixer.

In the present invention, the resin composition is melt-molded into a film or sheet. This melt molding may be performed by any method as long as it can be melt-kneaded to form a film or sheet by melting and kneading the resin composition. For example, a resin composition may be melt-kneaded using a conventional device such as a single-screw or twin-screw extruder or a twin-screw kneader, and then formed into a film or sheet by inflation molding, T-die extrusion molding, or the like. it can. At this time, if the antibacterial porous film is manufactured by a multi-layer molding method in which the antibacterial agent is mixed in the surface layer, the antibacterial property can be efficiently expressed with a small amount of the antibacterial agent, which is effective.

The temperature during melt kneading of the resin composition is usually
It is adjusted in the range of 200 to 280 ° C.

Further, in inflation molding, a uniaxially stretched or biaxially stretched film in a cylindrical shape can be drawn out from a circular die and uniaxially stretched by roll stretching. Further, in the molding using a T-die, after forming an unoriented sheet or film, uniaxial stretching by roll stretching or biaxial stretching by a tenter method can be performed.

In the present invention, the thickness of the film or sheet obtained by melt-molding the resin composition is not particularly limited and is appropriately selected according to the application.

Next, the resin composition molded into a film or sheet is stretched to obtain an antibacterial porous film. This stretching process, even uniaxial stretching,
It may be biaxially stretched, and is appropriately selected depending on the application. For example, in the case of uniaxial stretching, there is an advantage that the stretching treatment can be easily performed, and uniaxial stretching is advantageous for applications where the anisotropy of strength does not matter. Further, in the case of biaxial stretching, it is possible to further reduce the film thickness, which is effective for the purpose of improving the softness due to the reduction in rigidity and eliminating the anisotropy in strength.

In the case of uniaxial stretching, roll stretching is usually used and it may be carried out in one stage or in multiple stages of two or more stages. At this time, the stretching temperature is adjusted in the range of room temperature to the melting point of the resin,
By stretching at a stretch ratio of 1.2 to 8 times, preferably 2 to 6 times, an antibacterial porous film having a porosity of 50% or more, low rigidity and good texture can be obtained.

In the case of biaxial stretching, simultaneous or sequential stretching is carried out. At this time, the stretching temperature is from room temperature to the melting point of the resin, the stretching ratio is 1.2 to 8 times, preferably 2 to 6 times, the porosity is 50% or more, the rigidity is low, and the antibacterial porous film has a good texture. Can be obtained.

Further, it is effective to perform heat treatment after the uniaxial or biaxial stretching treatment, because an antibacterial porous film having excellent dimensional stability can be obtained. The heat treatment can be performed at a temperature ranging from 80 ° C. to the melting point of the film,
Usually, it is performed at high temperature for a short time.

Among the antibacterial porous films of the present invention, those having a porosity of 50% or more are preferable in that the antibacterial properties are good and the texture is excellent, and the porosity is 60 to 90.
% Is preferred.

The antibacterial porous film of the present invention can be combined with various non-woven fabrics, wariffs, woven fabrics, etc. to improve its strength.

[0031]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples of the present invention.

Example 1 LLDPE (Ultzex 2021L, manufactured by Mitsui Petrochemical Co., Ltd., MFR: 2.1 g)
/ 10 minutes, density: 0.920 g / cm ³ ) 50 parts by weight, calcium carbonate (manufactured by Takehara Chemical Co., Ltd., WS # 1500,
50 parts by weight (average particle diameter: 2.5 μm) and 1 part by weight of a powdered antibacterial agent (Zeomic, manufactured by Sinanene Zeomic Co., Ltd.) were mixed by stirring with a tumbler. The resulting mixture is
Cylinder temperature: 120/1 by supplying to a twin-screw extruder (TEX-44, screw diameter: 44 mm, manufactured by Nippon Steel Co., Ltd.)
After melt-kneading at 40/190 ° C, die temperature: 220
The film was extruded from a T-die at a temperature of ℃ and drawn at a take-up speed of 6 m / min to obtain a film having a thickness of 500 μm. The obtained film was stretched at a temperature of 75 ° C. and a stretching speed of 2 m / mi.
n, and draw ratio: longitudinal / horizontal = 3 / 1.5 times simultaneous biaxial drawing to obtain an antibacterial porous film having a thickness of 120 μm. With respect to the obtained antibacterial porous film, antibacterial property, stretchability, porosity, air permeability, moisture permeability and water pressure resistance were evaluated or measured according to the following methods. The results are shown in Table 1.

Antibacterial property 0.5 ml of a Staphylococcus aureus bacterium solution was dropped on a test piece (about 50 × 50 mm) and cultured at 37 ° C. for 24 hours. Then, the bacteria were washed out from the test piece with a sterilized phosphate buffer solution. The number of surviving bacteria in the washed-out liquid was measured by the pour plate method using a culture medium for measuring the number of bacteria. As a control, a test using only the bacterial solution was also performed.

Stretchability: The stretched state was visually inspected and evaluated according to the following criteria. ○ No stretching unevenness, no cutting × There is stretching unevenness or cutting

Porosity: The porosity was calculated from the following formula. Porosity = (d ₀ −d) / d ₀ × 100 d ₀ : Density of resin composition d: Density of stretched film

Air permeability: Evaluated according to JIS P8117. Water vapor transmission rate: Evaluated according to JIS P0208. Water pressure resistance: evaluated according to JIS L1092.

(Example 2) An antibacterial porous film was produced in the same manner as in Example 1 except that the amount of the powdered antibacterial agent (Zenomic, manufactured by Sinane Zeomic Co., Ltd.) was changed to 2 parts by weight, and an antibacterial film was prepared. Property, stretchability, porosity, air permeability, moisture permeability and water pressure resistance were evaluated or measured. The results are shown in Table 1.

(Example 3) Instead of LLDPE, polypropylene (manufactured by Mitsui Petrochemical Industry Co., Ltd., Hypol F-) was used.
600, MFR: 6 g / 10 minutes, density: 0.91 g / c
m ³ ), and the cylinder temperature is 160/200/23
An antibacterial porous film was produced in the same manner as in Example 1 except that 0 ° C., the die temperature was 230 ° C., and the film stretching temperature was 110 ° C., and the antibacterial property, the stretchability, the porosity, and the transparency were measured. The air quality, moisture permeability and water pressure resistance were evaluated or measured. The results are shown in Table 1.

(Comparative Example 1) LLDPE (Mitsui Petrochemical Co., Ltd., Ultzex 2021L, MFR: 2.1 g)
/ 10 minutes, density: 0.920 g / cm ³ ) only, using a twin-screw extruder (manufactured by Nippon Steel Co., Ltd., TEX-44, screw diameter:
44 mm) and cylinder temperature: 120/140
After melt-kneading at / 190 ° C, it was extruded from a T-die at a die temperature of 220 ° C and taken at a take-up speed of 6 m / min to obtain a film having a thickness of 500 µm. The obtained film was evaluated or measured for antibacterial property, stretchability, porosity, air permeability, moisture permeability and water pressure resistance in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 2) LLDPE (Mitsui Petrochemical Co., Ltd., Ultzex 2021L, MFR: 2.1 g)
/ 10 minutes, density: 0.920 g / cm ³ ) 50 parts by weight, calcium carbonate (manufactured by Takehara Chemical Co., Ltd., WS # 1500,
50 parts by weight (average particle diameter: 2.5 μm) and 1 part by weight of a powdered antibacterial agent (Zeomic, manufactured by Sinanene Zeomic Co., Ltd.) were mixed by stirring with a tumbler. The resulting mixture is
Cylinder temperature: 120/1 by supplying to a twin-screw extruder (TEX-44, screw diameter: 44 mm, manufactured by Nippon Steel Co., Ltd.)
After melt-kneading at 40/190 ° C, die temperature: 220
The film was extruded from a T-die at a temperature of ℃ and drawn at a take-up speed of 6 m / min to obtain a film having a thickness of 500 μm. The obtained film was evaluated or measured for antibacterial property, stretchability, porosity, air permeability, moisture permeability and water pressure resistance in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 3) A film having a thickness of 500 µm was obtained in the same manner as in Comparative Example 2 except that the amount of the powdered antibacterial agent (Zenomic, manufactured by Sinane Zeomic Co., Ltd.) was changed to 2 parts by weight. . The obtained film was evaluated or measured for antibacterial property, stretchability, porosity, air permeability, moisture permeability and water pressure resistance in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 4 A stretched film was produced in the same manner as in Example 1 except that the powdered antibacterial agent was not used.
The antibacterial property, stretchability, porosity, air permeability, moisture permeability and water pressure resistance were evaluated or measured in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 5) A stretched film was produced in the same manner as in Example 1 except that the stretching treatment was uniaxial stretching with a stretching ratio of 1.2 times in the longitudinal direction. Porosity, air permeability, moisture permeability and water pressure resistance were evaluated or measured in the same manner as in Example 1. The results are shown in Table 1.

[0044]

[Table 1]

[0045]

The antibacterial porous film of the present invention has porosity, has a large contact area between the antibacterial agent and air, and can exhibit excellent antibacterial properties with a small amount of the antibacterial agent.

Claims (9)

[Claims] 1. An antibacterial porous film obtained by stretching a film or sheet of a resin composition containing a polyolefin resin, an antibacterial agent and a filler. 2. The antibacterial porous film according to claim 1, which has a porosity of 50% or more. 3. The polyolefin resin 1 as the resin composition.
00 parts by weight, antibacterial agent 0.2-5 parts by weight, filler 5-20
The antibacterial porous film according to claim 1 or 2, which comprises 0 part by weight. 4. The antibacterial porous film according to claim 1, which has an air permeability of 1000 sec / 100 cc or less. 5. The antibacterial porous film according to claim 1, which has a water pressure resistance of 1000 mmH ₂ O or more. 6. A method for producing an antibacterial porous film, which comprises a step of melt-molding a resin composition containing a polyolefin resin, an antibacterial agent, and a filler into a film or sheet, and then stretching. 7. The polyolefin resin 1 is used as the resin composition.
00 parts by weight, antibacterial agent 0.2-5 parts by weight, filler 5-20
The method for producing an antibacterial porous film according to claim 6, which comprises 0 part by weight. 8. The method for producing an antibacterial porous film according to claim 6, wherein the stretching treatment is uniaxial stretching treatment. 9. The method for producing an antibacterial porous film according to claim 6, wherein the stretching treatment is biaxial stretching treatment.