JP3324873B2 - Microporous membrane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microporous membrane, and more particularly, to a filtration microporous membrane capable of removing trihalomethane dissolved in tap water.

[0002]

2. Description of the Related Art In recent years, separation methods using microporous membranes have been rapidly used on a practical scale from the viewpoints of resource saving, energy saving, separation and purification, and the like. Numerous microporous membranes used in such a membrane separation method have been studied.For example, a filler such as calcium carbonate is dispersed in a polyolefin, and the boundary between the polyolefin and the filler is separated at the interface to form a microporous membrane. What has been proposed is proposed as having excellent water permeability such as initial water permeability and water permeability during long-term use.

[0003] One of the uses of such a microporous membrane is to use the membrane formed into a hollow fiber or the like as a separation membrane of a water purifier. Water purifiers incorporating a hollow fiber membrane in the faucet of each household's water supply have become popular because of their simplicity. In this water purifier, the incorporated hollow fiber membrane causes the dead water of coliform bacteria, general bacteria, algae, mold, plankton, iron rust, and Al ₂ S contained in tap water.
Contaminant particles such as O ₄ , silica, sulfur, and Mg are removed.

[0004]

By the way, in addition to the above contaminating particles, various types of water such as Cl @-ion, trihalomethane, 2-methylisoborneol (MIB), diosmin, etc. are included in the water used for washing such as tap water. Hazardous substances are dissolved. However, in the purification by the hollow fiber membrane, such contaminants dissolved in the water cannot be substantially removed. Therefore, even in the water purified by the hollow fiber membrane, the harm caused by the dissolved contaminants, in particular, the generation of the contaminants can be reduced. The harm caused by trihalomethane, one of the cancerous substances, became a problem.

[0005] From such a background, in a water purifier using the hollow fiber membrane, an activated carbon layer having the ability to adsorb dissolved pollutants as described above is usually provided in addition to the hollow fiber membrane.
Attempts have been made to adsorb and remove the dissolved pollutants by passing water through the activated carbon layer. However, among the above-mentioned dissolved contaminants, trihalomethane has insufficient adsorbing ability to the above-mentioned activated carbon, and particularly when the amount of treated water increases, the adsorbing ability of the trihalomethane rapidly decreases. Therefore, in such a water purifier, if it is desired to remove trihalomethane in the purified water to be treated well over a long period of time, the filling amount of the activated carbon layer provided along with the microporous hollow fiber membrane must be excessively large. However, the size and cost of the apparatus have been increased.

[0006]

SUMMARY OF THE INVENTION In view of the above problems, the present inventors have developed a hollow fiber membrane in which a substance capable of strongly adsorbing and removing trihalomethane has been incorporated into a membrane. Various studies have been conducted with the aim of developing a microporous membrane in which a substance capable of strongly adsorbing and removing trihalomethane is incorporated into the membrane, considering that it is possible to provide inexpensive, safe and delicious water while maintaining the above conditions.

As a result, the present inventors have found that the above problems can be solved by dispersing chitin-based particles or chitosan-based particles in a film together with an inorganic filler or a synthetic resin filler, and have completed the present invention.

That is, the present invention relates to polyolefins 15 to 7
0% by weight, 84 to 20% by weight of an inorganic filler or a synthetic resin filler having an average particle diameter of 0.01 to 5 μm dispersed in the polyolefin and an average particle diameter of 0.0
Chitin-based particles or chitosan-based particles 1 to 5 μm
It is a microporous membrane having a network structure consisting of communicating holes having a maximum pore diameter of 5 μm or less, a porosity of 20 to 90% by weight, and a molecular orientation by stretching. .

In the present invention, the polyolefin used as the material of the microporous membrane includes a homopolymer of α-olefin such as polyethylene, polypropylene, polybutene-1 or polymethylpentene, and a monomer copolymerizable with α-olefin. And mixtures thereof and the like. Among them, homopolymers of propylene, copolymers of propylene with other copolymerizable monomers, and mixtures thereof are preferable in consideration of the heat resistance and moldability of the obtained microporous membrane.

The above-mentioned copolymer of an α-olefin and another copolymerizable monomer generally contains at least 90% by weight of an α-olefin, particularly propylene, and at most 10% by weight of another copolymerizable monomer. Copolymers are preferred. In addition, the copolymerizable monomer is not particularly limited, and known monomers can be used. Generally, α-olefins having 2 to 8 carbon atoms, particularly, ethylene and butene are preferable.

The inorganic filler and the synthetic resin filler used in the present invention may be used under the conditions of melt molding of polyolefin.
For example, those which are substantially stable at a temperature of 100 ° C. plus the melting point of the polyolefin and do not react with the polyolefin are preferred. In addition, it is preferable that when mixed with a polyolefin, it does not cause aggregation and is uniformly dispersed.
These fillers are used in the stretching step to cause separation at the interface between the polyolefin and the dispersed filler to form fine communication holes.

In the present invention, the inorganic filler can be used without particular limitation as long as it exhibits the above-mentioned functions.
In particular, those composed of oxides, hydroxides, carbonates, or sulfates of one metal selected from the group consisting of Group IIA, Group IIIA and Group IVB of the periodic table are preferred. As these inorganic fillers, those known as fillers of various synthetic resins can be used without any particular limitation. Examples of commonly used fillers are as follows. For example, Periodic Table II
Group A metals are alkaline earth metals such as calcium, magnesium, barium, etc. III Group A metals are metals such as boron, aluminum, etc.
The group IV metal is preferably a metal such as titanium, zirconium, hafnium, and the like, and the IVA group metal is preferably a metal such as silicon. Oxides, hydroxides, carbonates, or sulfates of these metals can be used without particular limitation. More specifically, particularly preferably used fillers, calcium oxide, magnesium oxide, boron oxide, titanium oxide,
Oxides such as zirconium oxide; carbonates such as calcium carbonate, magnesium carbonate and barium carbonate and their basic carbonates; hydroxides such as magnesium hydroxide, calcium hydroxide and aluminum hydroxide; calcium sulfate, barium sulfate; Sulfates such as aluminum sulfate; silicates such as calcium silicate, aluminum silicate and talc;

The above-mentioned inorganic filler is preferably surface-treated with silicone oil. By performing the surface treatment with the silicone oil in this manner, the dispersibility of the inorganic filler in the polyolefin and the moldability and stretchability of the polyolefin containing the inorganic filler are improved. The silicone oil used as the surface treatment agent is a polydialkylsiloxane represented by the following general formula.

[0014]

Embedded image

R is a fluid having a substituted or unsubstituted alkyl group, alkenyl group, phenyl group or hydrogen atom having 1 to 25 carbon atoms.

The average molecular weight of the silicone oil is not particularly limited, but it is generally 1,000 to 10%.
000 is preferably used. Average molecular weight of 1,000
When it is 0 or less, it volatilizes and scatters when forming a molten pellet, and when it is 100,000 or more, the uniformity of the surface treatment may be poor.

The amount of the silicone oil surface treating agent used is not particularly limited, but is generally preferably 0.5 to 5% by weight based on the inorganic filler. If the surface treatment concentration is too low, the interfacial separation between the polyolefin and the inorganic filler generated by stretching is small and the microporosity is not sufficient, or if the concentration is too high, a gas is generated during molding, which is preferable. Absent.

As a surface treatment method, a predetermined amount of an inorganic filler and silicone oil are put into a super mixer, and the mixture is rapidly stirred at 1000 to 2000 rpm for 2 to 5 minutes, and then heat-treated at 190 to 210 ° C. for 2 to 4 hours. do it.

On the other hand, as the synthetic resin filler used in the present invention, known synthetic resin fillers can be used without particular limitation to thermosetting resins and thermoplastic resins as long as they exhibit the above-mentioned functions. In consideration of gas generation due to softening or decomposition of the synthetic resin filler during molding, it is preferable that such a synthetic resin filler has a softening temperature or a decomposition temperature equal to or higher than the molding temperature of the polyolefin.

Specific examples of the synthetic resin particles which can be suitably used in the present invention include, for example, 6-nylon,
Polyamides such as 6,6-nylon; fluorine-based resins such as polytetrafluoroethylene and ethylene tetrafluoride-ethylene hexapropylene copolymer; polyimides; silicone resins; phenolic resins; benzoguanamine resins; A copolymer of methacrylic acid, methyl acrylate, methyl methacrylate and the like with a crosslinking agent such as divinylbenzene is preferred. Above all, silicone resins are preferably used in the present invention because they have good interfacial releasability from polyolefin and can be easily made porous by stretching.

The average particle diameter of the above-mentioned inorganic filler and synthetic resin filler is determined by the ability to remove trihalomethane, the dispersibility in polyolefin and the moldability of polyolefin film, the prevention of aggregation between particles, and the constant filtration. In consideration of keeping the speed, the thickness needs to be 0.01 to 5 μm. The average particle diameter of the filler for obtaining a suitable microporous membrane is preferably from 0.03 to 3.5 μm.

The narrower the particle size distribution of these fillers is, the more preferable uniform pores are obtained. Generally, when the particle size distribution is represented by dispersion, the dispersion is preferably 1.5 or less, more preferably 0.1 or less. Also,
The shape may be any shape, but usually,
It is preferable that the ratio of the major axis to the minor axis be spherical or elliptical in the range of 1 to 2 in order to obtain pores having a uniform diameter. The above ratio is preferably in the range of 1 to 1.5.

In the microporous membrane of the present invention, chitin-based particles or chitosan-based particles are dispersed in the polyolefin in addition to the above-mentioned inorganic filler or synthetic resin filler. The chitin-based particles or chitosan-based particles, in the same manner as the inorganic filler or the synthetic resin filler, cause separation at the interface with the polyolefin in the stretching step to form fine communication holes. It has the function of satisfactorily adsorbing and removing trihalomethane when tap water flows. Here, it is preferable that the chitin-based particles and the chitosan-based particles are uniformly dispersed without causing aggregation when mixed with a polyolefin, an inorganic filler, or a synthetic resin filler.

Here, chitin is β-1,4-poly-
N-acetyl-D-glucosamine is a basic natural polymer compound widely present in nature such as crab and shrimp shells, insect epidermis and fungal cell walls. On the other hand, chitosan is β-1,4-poly-D-glucosamine, and is a polymer compound obtained by deacetylating the above chitin by hydrolysis with an alkali or the like. In the present invention, as the chitin-based particles and chitosan-based particles, such chitin or chitosan, and particles composed of such chitin or chitosan derivative can be used without any limitation. Specifically, chitin obtained from a natural product; chitosan obtained by hydrolyzing chitin with an alkali; polyoxyethylenated chitin, chitosan salt, grafted chitosan salt, sulfated chitosan, cross-linked chitosan, activated chitosan, Examples include particles of chitin such as crystallized chitosan and stabilized chitosan, and chitosan derivatives.

The average particle diameter of these chitin-based particles and chitosan-based particles needs to be 0.01 to 5 μm as in the case of the above-described inorganic filler and synthetic resin filler. In addition, the particle size distribution is preferable because uniform pores are obtained as narrow as possible, and the shape may be any shape, but in general, a spherical or elliptical shape, or a shape similar thereto has a uniform diameter. It is preferable for obtaining pores.

In the present invention, the above polyolefin,
The mixing ratio of the inorganic filler or the synthetic resin filler and the chitin-based particles or chitosan-based particles is such that the polyolefin is 1
5 to 70% by weight, preferably 20 to 65% by weight;
84-20% by weight of an inorganic filler or a synthetic resin filler,
It is preferably 79 to 30% by weight, and chitin-based particles or chitosan-based particles are 1 to 10% by weight, preferably 1 to 5%.
% By weight. The mixing ratio of each component is important for maintaining the properties of the microporous membrane in a specific range and industrially advantageously producing the microporous membrane. When the blending ratio of the inorganic filler or the synthetic resin filler component is less than the lower limit, pore formation of the obtained microporous membrane becomes insufficient, and conversely, the blending ratio of this component is greater than the upper limit. If this is the case, the moldability of the hollow fiber membrane tends to be poor and the stretching cannot be performed sufficiently. On the other hand, when the mixing ratio of the chitin-based particles or the chitosan-based particle component is less than the lower limit, the trihalomethane adsorption ability of the obtained microporous membrane becomes insufficient, and conversely, the mixing ratio of this component is higher than the upper limit. It is not preferable to increase the content because the moldability of the hollow fiber membrane tends to deteriorate and the stretching cannot be performed sufficiently.

In the present invention, a film formed of the above-mentioned polyolefin and a mixture of an inorganic filler or a synthetic resin filler and chitin-based particles or chitosan-based particles dispersed in the polyolefin is formed by molecular stretching by stretching. Oriented. As a result, the microporous membrane of the present invention is a polyolefin and the above-mentioned inorganic filler or synthetic resin filler,
Alternatively, the interface between the chitin-based particles or the chitosan-based particles is peeled off, and communication pores having a maximum pore diameter of 5 μm or less are formed in a network in the membrane. Here, in the present invention, the value of the maximum pore diameter refers to a value measured by a methanol bubble point method. When the maximum pore diameter of the communicating pores formed in the microporous layer exceeds 5 μm, although the obtained microporous membrane has good water permeability such as water from the top, the trihalomethane removal performance and liquid / It is not preferred because it reduces the separation performance between solid, liquid / gas, liquid / liquid, and gas / solid. In the present invention, in consideration of the suitable amount of water permeation such as tap water, the maximum pore diameter is preferably 0.01 to 3 μm. Further, in consideration of the filtration performance of Escherichia coli and the like, the maximum pore diameter is preferably 1.5 μm or less. The communicating holes formed in the microporous membrane usually have an average pore diameter of 0.005 to 3 μm.

The microporous membrane of the present invention has a porosity of 2
It is 0 to 90%, preferably 35 to 85%. At this porosity, water permeability and separation performance are the most excellent. In the present invention, the thickness of the microporous membrane described above is not particularly limited, but is generally from 10 μm to
It is preferably in the range of 0.5 mm. In addition, the shape is not particularly limited, and can be used, for example, in the form of a film or the like according to the use mode. However, in order to function effectively as a separation membrane, it is preferably used as a hollow fiber membrane. In this case, the outer diameter of the hollow fiber membrane is 50 μm to 5 m.
It is preferable to set the range of m.

In the present invention, the microporous membrane described above may be manufactured by any method. Usually, the polyolefin is 15 to 70% by weight and the average particle diameter is 0.01%.
Inorganic filler or synthetic resin filler 84 to
It is common to produce a mixture of 20% by weight and a mixture of chitin-based particles or 1-10% by weight of chitosan-based particles having an average particle diameter of 0.01 to 5 μm, and then stretch the film to produce the mixture. is there.

At this time, it may be difficult to mix the polyolefin component, the filler component and the chitin-based or chitosan-based particle components in large amounts and uniformly. It is preferable to add a specific amount of a dispersant. That is, the polyolefin component , the filler component, and chitin-based particles or chitosan
It is preferable to add 0.1 to 20 parts by weight of a dispersant based on 100 parts by weight of the total amount of the system particle component in order to obtain a microporous hollow fiber membrane having a uniform pore diameter.

As the dispersant, a known compound added as a plasticizer to various synthetic resins can be used without any particular limitation. The dispersants generally preferably used are polyester-based plasticizers and epoxy-based plasticizers, and terminally OH-terminated polybutadiene is also preferably used. These are exemplified as follows.

The polyester plasticizer is generally obtained by an esterification reaction of a dibasic acid or tribasic acid having a linear or aromatic ring having 4 to 8 carbon atoms with a linear dihydric alcohol having 2 to 5 carbon atoms. Those that have been made are preferred. Specific examples of those particularly preferably used include dibasic acids or tribasic acids such as sebacic acid, adipic acid, phthalic acid, azelaic acid and trimellitic acid, and ethylene glycol,
Polyester compounds comprising propylene glycol, butylene glycol, neopentyl glycol and long-chain alkylene glycol, especially polyester compounds comprising adipic acid or sebacic acid and propylene glycol, butylene glycol or long-chain alkylene glycol. Is preferably used.

The epoxy plasticizer has 8 carbon atoms.
Epoxidized double bonds of monobasic linear unsaturated acids of from 24 to 24 are preferred. Particularly preferred examples include epoxidized soybean oil and epoxidized linseed oil, which can be used alone or in combination.

Further, a plasticizer having polybutadiene having a degree of polymerization of 500 to 3,000, preferably 500 to 1,000 at both ends of OH is also preferably used as a dispersant.

When the above components are mixed, a coloring agent, a lubricant,
It is often a good practice to add known additives such as antioxidants, antioxidants, hydrophilizing agents, hydrophobizing agents and the like.

The microporous membrane of the present invention can be obtained by subjecting the mixture to melt film formation on a hollow fiber membrane or the like under specific conditions and then stretching. Here, when the above mixture is formed into a hollow fiber membrane, the method is not particularly limited,
In general, it is preferable to form a hollow fiber membrane using a known extruder for manufacturing a hollow fiber having a double cylindrical die.

The method of stretching the unstretched film is not particularly limited, but is generally uniaxially stretched by a difference in the rotation speed ratio between two pairs of Nelson rolls or the like, or if necessary, is followed by known stretching. A method of sequentially stretching in the horizontal direction by a widening stretching machine or the like, or a method of simultaneously stretching in the vertical and horizontal directions. In this case, the stretching magnification is preferably preferably in the range of 1.5 to 10 times the area stretching magnification.
When stretching only in the uniaxial direction (the longitudinal direction of the hollow fiber),
In general, it is preferable to stretch 1.5 to 8 times, preferably 3 to 7 times. When stretching in the biaxial direction, 1
1.2 times or more, preferably 1.5 times or more in the axial direction (longitudinal direction of the hollow fibers), and 1.2 times or more, preferably 1.5 times or more in the biaxial direction (the circumferential direction of the hollow fibers). The stretching is preferably 2 to 5 times in the uniaxial direction and 2 to 5 times in the biaxial direction. The stretching temperature is generally from room temperature to the melting point of the polyolefin, and preferably from 10 to 100 ° C. below the melting point.

The microporous membrane obtained by stretching is further subjected to a heat treatment under tension, for example, a heat-setting treatment at a temperature not lower than the stretching temperature and not higher than the melting point, and then cooled to room temperature to obtain the desired product. Is preferred. In addition, it is a preferable embodiment to perform a surface treatment such as a corona discharge treatment, a hydrophilic treatment, or a hydrophobic treatment for the purpose of improving the adhesiveness.

In the microporous membrane produced by the above method, the polyolefin is molecularly oriented by stretching,
Alternatively, by further heat fixing, the heat resistance of the film itself is significantly improved, and the mechanical strength is also improved. In particular, in the case of heat setting, the dimensional stability at normal temperature and high temperature is also remarkably improved.

[0040]

As described above, the microporous membrane obtained by the present invention is excellent in heat resistance since the material is rich in polyolefin, and has excellent physical properties such as strength, chemical resistance and biocompatibility. I have. Furthermore, inorganic fillers and synthetic resin fillers contained in the membrane, or chitin-based particles or chitosan-based particles are extremely stable to water, so that they are highly reliable in use, for example, the fillers elute during water purification. It has the feature that there is no trouble to do.

In addition, it has good trihalomethane removal ability, and erroneously contains trihalomethane at a concentration several tens times that of the Ministry of Health and Welfare Ordinance No. 69 “Total trihalomethane 0.1 ppm or less specified by the Ministerial Ordinance on Water Quality Standards”. Even if it does, it can be removed to 0.1 ppm or less.
The effect can be maintained satisfactorily even after filtering 4 tons / m ^{2 of} clean water, and a compact water purifier capable of providing safe and delicious water can be provided.

Further, the microporous membrane of the present invention is also excellent in water permeability. For example, when the microporous membrane is made of a hollow fiber, the initial water permeability is as high as 20 l / min · m ² · atm or more. １００100 l / min · m ² · atm,
Moreover, the decrease in water permeability due to clogging is small, for example,
Even after filtering 4 tons / m ^{2 of} tap water, it has a water permeability of 3 l / min · m ² · atm or more.

As described above, the microporous membrane of the present invention enables a water purifier that can be used as a good filtration membrane for a long period of time, has a trihalomethane adsorption ability, and can provide safe and delicious water. Therefore, the microporous membrane of the present invention can be used as a household water purifier, as well as an air filter for dust removal, sterilization and deodorization; a gas separation membrane; a wastewater treatment; Water production: It can be used for blood purification, artificial lungs, dialysis membranes and the like in the medical field, and is suitably used for microfiltration and as a support for ultrafiltration, reverse osmosis membranes, pervaporation, and the like.

[0044]

EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. The physical properties and judgments of the hollow fiber membranes shown in Examples and Comparative Examples indicate values measured or judged by the following methods.

Maximum pore diameter (μ): measured by a methanol bubble point method.

The porosity (%) was measured using a mercury intrusion-type pore sizer 9310 manufactured by Shimadzu Corporation.

Water permeation amount: Ten microporous hollow fiber membranes were bundled and the hollow fiber membrane opening was hardened with epoxy resin to produce a module. The effective length of the hollow fiber excluding the resin embedded part is 15
cm. In the measurement of water permeability, the module was immersed in a 2% ethanol solution of a nonionic surfactant having an HLB of 21 and then water of 1 atm was applied to determine the amount of water passing through the wall surface of the hollow fiber membrane. . The membrane area was (outer diameter + inner diameter) / 2 base. The value obtained when the water permeability test was first performed for 3 minutes was referred to as the initial water permeability, and the value after permeating 4 tons / m ^{2 of} tap water was referred to as 4 tons water permeability. The clean water used in the water permeability test was water obtained by adding 1,1,1-trichloroethane (Wako Pure Chemical Industries) to the tap water in Tokuyama City, Yamaguchi Prefecture by adding 1 and 30 ppm.

Concentration of trihalomethane; Ministry of Health and Welfare Ordinance No. 69
No. "Ministerial Ordinance on Water Quality Standards" (JIS K
It was measured using an ion chromatograph based on 0125, 51).

Moldability: The undrawn hollow fiber membrane was visually observed and touched by hand, and evaluated according to the following criteria.

Good: Uneven thickness and no surface irregularities.

Slightly good; one of uneven thickness and unevenness on the surface is minute.

Poor: a state where the thickness is uneven and the surface is uneven.

Stretchability: The stretchability was determined based on the stretched state when the unstretched hollow fiber membrane was stretched in the longitudinal direction of the hollow fiber.

Good: A state in which stretching is performed uniformly without cutting or tearing.

Moderately good: A state in which a very small unstretched portion exists in a part even if stretching is possible.

Poor: A state where cutting and tearing are apt to occur and stretching cannot be performed uniformly. Examples 1 to 13 and Comparative Examples 1 to 10 Resins, inorganic fillers, synthetic resin fillers, chitin-based particles, chitosan-based particles, surface treatment agents as shown in Tables 1 and 2,
After mixing the dispersant composition for 5 minutes with a super mixer, the mixture was extruded into a strand at 220 ° C. by a twin screw extruder and cut into pellets. The obtained pellets are extruded at 220 ° C. from a hollow fiber manufacturing nozzle having a double pipe structure of 0.7 mm in diameter attached to an extruder having a screw diameter of 20 mm φ and L / D = 22, and water of about 20 ° C. is circulated. The mixture was cooled by placing it in a water tank to be drawn and taken at 10 to 50 m / min to obtain an undrawn hollow fiber.

The undrawn hollow fiber was uniaxially drawn at 120 ° C. at a draw ratio of 5 between two Nelson rolls having different rotation speeds to obtain a microporous hollow fiber membrane. Tables 3 and 4 show the physical properties of the obtained microporous hollow fiber membrane.

The resin used, inorganic filler, synthetic resin filler, chitin-based particles, chitosan-based particles, surface treatment agent,
The following products were used as dispersants.

Polyolefin resin; Polypropylene; PN-120 (trade name), manufactured by Tokuyama Corporation, density 0.91 g / cm ³ , intrinsic viscosity 2.38 dl / g, measured with tetralin at 135 ° C., melting point 166 ° C.

Propylene-ethylene copolymer; MS-624 (trade name), manufactured by Tokuyama Corporation, density 0.90 g / cm ³ , 135 ° C.
Intrinsic viscosity 2.28dl / g measured with tetralin, melting point 163 ℃
, Ethylene content 4.7% by weight.

Polyethylene; Mitsui Petrochemical Industry Co., Ltd.
Made, high density polyethylene, HIZEX 1300J (trade name), melt index 1.3g / 10min.

Inorganic filler; calcium carbonate; Tsunex E (trade name) manufactured by Shiraishi Industry Co., Ltd., average particle size 0.5 μm.

Viscolite U manufactured by Shiraishi Calcium Co., Ltd.
(Trade name), average particle size 0.09 μm.

Talc; 850, manufactured by Nippon Mistron Co., Ltd.
-JS (trade name), average particle size 0.9 µm.

Basic spherical magnesium carbonate; KT-115 (trade name), manufactured by Tokuyama Corporation, average particle size 4 μm
m.

Synthetic resin filler; Silicone resin (A); Toray Silicone Co., Ltd., Trefil R-935 (trade name) spherical particles having an average particle diameter of 4 μm, dispersed
1.5.

Silicone resin (B): manufactured by Toray Silicone Co., Ltd., Trefil R-925 (trade name), average particle size 0.5
μm spheres, dispersion 0.007.

Methyl methacrylic acid-divinylbenzene copolymer; MP3000 (trade name), manufactured by Soken Chemical Co., Ltd., spherical particles having an average particle diameter of 0.4 μm, dispersion 0.007.

Chitin-based particles and chitosan-based particles; chitin-based particles; chitin (reagent) manufactured by Wako Pure Chemical Industries, Ltd.
Using a dancing agitator _II type agitator / pulverizer manufactured by Hirosawa Ironworks Co., Ltd., pulverized at 5,000 rpm while cooling with liquid N ₂ to have an average particle diameter of 0.1 to 3 μm.

Activated Chitopearl K-20 (trade name), manufactured by Fuji Boseki Co., Ltd .;
While cooling 350 μm with liquid N ₂ using a Dansin Agitator _II type agitator / pulverizer manufactured by Hirosawa Ironworks Co., Ltd.
The powder was pulverized at 0 rpm to obtain an average particle diameter of 0.1 to 3 μm. And the crushed product is further crushed and classified to 0.05μm
The average particle size of

Surface treatment agent; Silicone oil; S, manufactured by Dow Corning Toray Co., Ltd.
H-200 (grade), molecular weight 10,000 Chemical structure: polydimethylsiloxane (OSi (CH ₃ ) ₂ O) _n dispersant; Nippon Soda Co., Ltd., terminal OH-modified polybutadiene, GI-1000 (grade name).

[0072]

[Table 1]

[0073]

[Table 2]

[0074]

[Table 3]

[0075]

[Table 4]

Claims (1)

(57) [Claims] 1. A polyolefin having an average particle diameter of from 15 to 70% by weight and dispersed in said polyolefin having an average particle size of 0.0
Inorganic filler or synthetic resin filler 84 having a size of 1 to 5 μm
A chitin-based particle or a chitosan-based particle having an average particle diameter of 0.01 to 5 μm and a chitosan-based particle of 1 to 10% by weight, having a network structure of communicating pores having a maximum pore diameter of 5 μm or less; A microporous membrane having a ratio of 20 to 90% by weight and being molecularly oriented by stretching.