JP2003230807A - Electret filter medium and air filter using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electret filter medium excellent in the filtering efficiency, pressure loss and charge life, and an air filter using the same. <P>SOLUTION: The electret filter medium comprises a molding including a resin compound containing a polyamine having a repeating structure represented by formula (1) (wherein, R<SP>1</SP>to R<SP>8</SP>are each independently a 1-4C alkyl group or hydrogen and n is 0 or 1. When n is 0, R<SP>9</SP>is a 4-15C alkylene group, which may have a substituent selected from the group consisting of a 1-4C alkyl group and a phenyl group. When n is 1, A is a 1-4C alkyl group or a phenylene group wherein a hydrogen atom on a ring may be substituted and R<SP>9</SP>and R<SP>10</SP>are each independently a 1-8C alkylene group and the sum of the number of carbon atoms of the alkylene groups of R<SP>9</SP>and R<SP>10</SP>is 2-9). The air filter is equipped with this electret filter medium. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electret filter medium and an air filter using the same. More specifically, it relates to an electret filter material that can be used for an air cleaner, a mask, and the like, and an air filter using the same.

[0002]

2. Description of the Related Art Conventionally, a filtering material made of a non-woven fabric has been used to remove dust and the like in a gas. This non-woven fabric filter material is mainly used for brown diffusion due to physical action,
Since dust or the like is removed by blocking or inertial collision, if the diameter of the fiber forming the non-woven fabric filtering material is made smaller, the dust or the like can be captured and removed, so that the filtration efficiency can be improved. However, there has been a problem that the smaller the diameter of the fibers constituting the non-woven fabric filter material, the larger the pressure loss and the shorter the life of the non-woven fabric filter material.

As a method for solving this problem, it has been attempted to make the non-woven fabric filter material into an electret and utilize electrostatic action in addition to physical action to achieve both filtration efficiency and pressure loss. According to this method, it is possible to achieve both the filtration efficiency and the pressure loss to some extent, but since the charge amount is insufficient, various additives are added to the fibers constituting the nonwoven fabric filtration material, Further, the amount of electric charge is being increased.

For example, Japanese Patent Application Laid-Open No. 1-287914 discloses that "a polypropylene having a specific molecular weight distribution is blended with a hindered amine-based stabilizer, and the trap charge amount is 7.5.
An electret material having a coulomb of x10 ^-10 coulomb / cm ² or more is disclosed, and Japanese Patent Publication No. 11-510862 discloses "non-conductive thermoplastic resin and (a) at least 1".
Thermostable organic compound or oligomer having one perfluorinated moiety, or (b) a thermostable organic triazine compound or oligomer having at least one nitrogen atom other than the nitrogen atom of the triazine group of the oligomer. A method of producing a fiber electret material using a fiber web of non-conductive thermoplastic fibers from a blend with an additive that is a triazine compound or oligomer, or (c) a combination thereof. .

[0005]

However, even when such an additive is blended, the charge amount is insufficient, so that the filtration efficiency and the pressure loss are not compatible with each other. Due to insufficient stability, the charge life was short.

The present invention has been made to solve the above problems, and provides an electret filter material excellent in filtration efficiency, pressure loss, and charge life, and an air filter using the same. With the goal.

[0007]

DISCLOSURE OF THE INVENTION The invention relating to the electret filter medium of the present invention is "an electret filter medium comprising a molded body containing a resin material containing a polyamine having a repeating structure represented by the following general formula (I). .

[Chemical 2] (In the formula, each of R ^{1 to} R ⁸ independently has 1 to 4 carbon atoms.
Represents an alkyl group or hydrogen, and n represents 0 or 1. When n is 0, R ⁹ represents an alkylene group having 4 to 15 carbon atoms which may have a substituent selected from the group consisting of an alkyl group having 1 to 4 carbon atoms and a phenyl group. When n is 1, A represents a phenylene group in which a hydrogen atom on the ring may be substituted with an alkyl group having 1 to 4 carbon atoms, and R ⁹ and R ¹⁰ are each independently the number of carbon atoms. It represents an alkylene group of 1 to 8, and the sum of the number of carbon atoms of the alkylene group of R ⁹ and R ¹⁰ is in the range of 2 to 9. ) ”, Which is excellent in filtration efficiency, pressure loss, and thermal stability, and is excellent in charge life. In particular, at least one of R ¹ , R ² , R ⁷ , and R ⁸ of the polyamine having the repeating structure represented by the general formula (I) is a hydrogen atom, and R ³ , R ⁴ , and R ^{5 are} ,
When at least one of R ⁶ is a hydrogen atom, when all R ^{1 to} R ^{8 of the} polyamine having the repeating structure represented by the general formula (I) are hydrogen atoms, When the number average molecular weight of the polyamine having a repeating structure represented is in the range of 500 to 100,000, the content of the polyamine having a repeating structure represented by the general formula (I) is 0.01 to 100% of the whole resin material. 5m
%, when the resin material is a polyolefin resin, when the molded body is a fiber sheet, and when the molded body is a melt-blown nonwoven fabric, the filtration efficiency, pressure loss, and thermal stability It has been found to be excellent in terms.

The invention relating to the air filter of the present invention is
It is an "air filter equipped with the above-mentioned electret filter medium" and is found to be excellent in terms of filtration efficiency, pressure loss, and thermal stability.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The electret filter material of the present invention comprises a molded body containing a resin material containing a polyamine having a repeating structure represented by the following general formula (I).

[Chemical 3] (In the formula, each of R ^{1 to} R ⁸ independently has 1 to 4 carbon atoms.
Represents an alkyl group or hydrogen, and n represents 0 or 1. When n is 0, R ⁹ represents an alkylene group having 4 to 15 carbon atoms which may have a substituent selected from the group consisting of an alkyl group having 1 to 4 carbon atoms and a phenyl group. When n is 1, A represents a phenylene group in which a hydrogen atom on the ring may be substituted with an alkyl group having 1 to 4 carbon atoms, and R ⁹ and R ¹⁰ are each independently the number of carbon atoms. It represents an alkylene group of 1 to 8, and the sum of the number of carbon atoms of the alkylene group of R ⁹ and R ¹⁰ is in the range of 2 to 9. )

In the above general formula (I), R ^{1 to} R ⁸ each independently consist of an alkyl group having 1 to 4 carbon atoms or hydrogen. When the alkyl group becomes long, it tends to be affected by steric hindrance during the polyamine synthesis, and the reaction is likely to slow down, resulting in a decrease in the molecular weight of the polyamine, a decrease in the melting point, and further an affinity for water. The property is likely to be strong and the amount of charge tends to decrease, which is not preferable. Therefore, rather than R ^{1 to} R ⁸ all being substituted with an alkyl group, R ¹ , R ² ,
At least one of R ⁷ and R ⁸ is a hydrogen atom, and at least one of R ³ , R ⁴ , R ⁵ , and R ⁶ is a hydrogen atom, or all of R ^{1 to} R ⁸ are hydrogen atoms. Is more
It is more preferable from the viewpoint of synthesis, and further from the viewpoint of the charge amount of the resulting polyamine.

In the above general formula (I), when n is 0, R ⁹ is a carbon atom which may have a substituent selected from the group consisting of an alkyl group having 1 to 4 carbon atoms and a phenyl group. It represents an alkylene group having a number of 4 to 15. In such a case, R ⁹ is, for example, butylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group. , A linear alkylene group such as a tetradecamethylene group and a pentadecamethylene group; a part of hydrogen atoms of these linear alkylene groups is a methyl group, an ethyl group, a propyl group,
Examples thereof include an alkylene group substituted with a substituent selected from the group consisting of a butyl group and a phenyl group. Among these alkylene groups, a linear alkylene group having 4 to 15 carbon atoms is preferable, and a linear alkylene group having 6 to 12 carbon atoms is particularly preferable.

The polyamine having only the structure in which n is 0 and R ⁹ is a methylene group as the repeating structure represented by the general formula (I) has a high melting point and is extremely hard. Therefore, it cannot be used because the dispersibility in the resin material during kneading is poor.

The polyamine having a repeating structure represented by the general formula (I) may have the same or different repeating structures. For example, when n is 0, R ⁹ contained in the repeating unit. May be combined with a small amount of an alkylene group having a small number of carbon atoms such as a methylene group, an ethylene group or a propylene group, and an alkylene group having a large number of carbon atoms such as a hexamethylene group or a decamethylene group.
However, when combining in this way,
If the proportion of methylene groups is too high, the resulting polyamine will have a very high melting point and become very stiff, and the dispersibility in the resin material during kneading will tend to be poor. If the proportion of is too large, the resulting polyamine has a strong hydrophilicity derived from the piperazine group and has a strong affinity with water. It tends to decrease. Therefore, when an alkylene group having a small number of carbon atoms is combined, the proportion of the alkylene group having a small number of carbon atoms is preferably 10% or less in terms of mol based on all R ⁹ contained in the polyamine.

When n is 1, A represents a phenylene group in which a hydrogen atom on the ring may be substituted with an alkyl group having 1 to 4 carbon atoms, and the phenylene group is a p-phenylene group or m-. Although it may be either a phenylene group or an o-phenylene group, a p-phenylene group is particularly preferable.
R ⁹ and R ¹⁰ each independently represent an alkylene group having 1 to 8 carbon atoms, and the sum of the carbon atoms of the alkylene group of R ⁹ and R ¹⁰ is in the range of 2 to 9.

When n is 1, examples of R ⁹ and R ¹⁰ include methylene group, ethylene group, propylene group, butylene group, pentamethylene group, hexamethylene group, heptamethylene group and octamethylene group.

In the general formula (I), a polyamine in which n is 0, R ^{1 to} R ⁸ are all hydrogen atoms, and R ⁹ is a linear alkylene group having 4 to 15 carbon atoms is used. A polyamine in which R ⁹ is a linear alkylene group having 6 to 12 carbon atoms is particularly preferable. In the general formula (I), n is 1, R ^{1 to} R ⁸ are all hydrogen atoms, A is a p-phenylene group, and R ⁹ and R ¹⁰ are both methylene groups. Polyamines are especially preferred.

The number average molecular weight of the polyamine used in the present invention is preferably in the range of 500 to 100,000, particularly preferably in the range of 5,000 to 30,000.
When the number average molecular weight of the polyamine is less than 500, the melting point of the polyamine is low, and the polyamine tends to scatter during kneading when processed into a molded product. When the number average molecular weight of the polyamine exceeds 100,000, the above-mentioned kneading occurs. Dispersibility tends to be inferior.

The melting point of the polyamine is preferably 80 ° C. or higher, more preferably 120 ° C. or higher. If the melting point is less than 80 ° C, it tends to volatilize or scatter during kneading or molding processing. On the other hand, the melting point of the polyamine is preferably 300 ° C. or lower. If the melting point exceeds 300 ° C, the dispersibility during kneading tends to be poor.

The "melting point" in the present invention means the temperature which gives the maximum value of the melting endothermic curve obtained by raising the temperature from room temperature at a temperature rising rate of 10 ° C./min using a differential scanning calorimeter.
When there are two or more maximum values, the maximum value at the lowest temperature is taken as the melting point.

Further, the polyamine does not almost volatilize or decompose due to heat at the time of manufacturing or using the resin material, the molded body, or the electret filter medium, and the polyamine can retain the electric charge at a temperature of 180 to 350 ° C. Within the range, it is preferable that the thermal stability is excellent.

The content of such polyamine is preferably 0.01 to 5 mass% of the entire resin material. Although the polyamine content is less than 0.01 mass%, the thermal stability of the charge and the filtration efficiency tend to be poor even though the polyamine content is less than 0.01 mass%. It is more preferably 1 mass% or more. On the other hand, the content of polyamine is 5 mass%
If it exceeds 1.0, the moldability tends to deteriorate and the strength of the resin material tends to deteriorate, so that it is more preferably 2.5 mass% or less, and further preferably 1.5 mass% or less.

The electret filter material of the present invention contains the resin material containing a polyamine as described above.
The resin material may contain, in addition to the polyamine as described above, stabilizers usually contained in the resin material, such as an antioxidant, a light stabilizer and a heat stabilizer.

The electret filter material of the present invention is
A resin material containing no polyamine as described above, a charge amount that can be increased, for example, a hindered amine compound, an aliphatic metal salt (for example, magnesium salt of stearic acid, aluminum salt of stearic acid, etc.), unsaturated It may contain a resin material containing a carboxylic acid-modified polymer or the like.

The resin material constituting the molded body which is the electret filter material of the present invention may be composed of any resin, but the charge amount can be increased, resulting in excellent filtration efficiency and pressure. It is preferable to use a resin having a volume resistivity of 10 ¹⁵ Ω / cm or more, which can reduce the loss. Examples of the resin having such a volume resistivity value include, for example, polyolefin resins (for example, polyethylene resins, polypropylene resins, polymethylpentene resins, polystyrene resins, etc.), ethylene tetrafluoride, polyvinylidene chloride, Examples thereof include polyvinyl chloride, methacrylic resin and polyurethane. Among these, polyolefin resins are particularly preferable because they have a high volume resistivity, are thermoplastic, and are easy to process. Among these, polypropylene-based resins or polymethylpentene-based resins are particularly preferable because they are also excellent in heat resistance.

The molded product containing the resin material containing polyamine as described above, that is, the electret filter medium may have any structure, for example, a porous base material such as a fiber sheet structure or a fiber sheet. Examples thereof include a structure in which a fiber and / or film is cut (for example, a strip shape) and a split film is filled therebetween. Among these, a fibrous sheet structure such as a non-woven fabric, a woven fabric, and a knit fabric, which has excellent handleability and processability, is preferable, and a non-woven fabric structure having excellent filtration efficiency is more preferable. Among the nonwoven fabric structures, the melt blown nonwoven fabric has a small fiber diameter (average fiber diameter: 0.1 μm to 10 μm).
m) and the filterability by physical action are also excellent, and are particularly preferable.

The electret filter material of the present invention may have any form, for example, a sheet form, a plate-like form in which the sheet is folded in a zigzag form, or a sheet is folded in a zigzag form. Examples thereof include a cylindrical shape, a bag shape, and a bowl shape.

Such an electret filter material of the present invention comprises the above-mentioned molded body, and since this molded body has a large amount of charges due to the action of polyamine, it has excellent filtration efficiency and low pressure loss. Is. Further, it has excellent thermal stability and a long charge life.

When the electret filter material of the present invention has a fiber sheet structure, it can be manufactured, for example, as follows.

First, the polyamine and the resin material as described above are prepared.

Next, after kneading the polyamine and the resin material, the polyamine and the resin material are extruded from an extruder to obtain a film, a fiber,
It is processed into a desired structure such as a fiber web or a non-woven fabric. In addition, when a film is formed, it is preferable that the film is cut (for example, a strip shape) into a fibrous shape (hereinafter, referred to as “split fiber”).

Next, fibers or split fibers are used to form a fiber sheet by a conventional method. For example, when the fiber sheet is made of a woven fabric or a knitted fabric, it can be produced by forming a yarn using the fiber and / or the split fiber, and then weaving or knitting the yarn. When the fiber sheet is made of a nonwoven fabric, the fiber and / or split fiber is used to form a fiber web by a dry method or a wet method, and then the fiber web is bonded to produce a nonwoven fabric, or the fiber is used. After forming the web by the spunbond method or the melt blow method, the fibrous web can be bonded to produce a non-woven fabric.

Then, for such a fiber sheet,
The electret filter medium of the present invention can be manufactured by performing electretization treatment. This electretization method is not particularly limited, for example, electron beam irradiation, corona charging, optical electret, the electric field is applied to the ions generated by creeping discharge to move the ions to move the ions into the fiber sheet. And a method of causing a water stream to collide with the fiber sheet or the fiber web. The electretization treatment can be performed at room temperature or in a heated state, or can be performed under atmospheric pressure or under a pressure higher than atmospheric pressure.

The electret filter material which can be produced in this manner is generally in the form of a sheet, but the fiber sheet before being subjected to the electret treatment may be molded into a desired shape and then the electret treatment may be carried out. After carrying out the chemical treatment, it can be molded into a desired shape. For example, (1) a fiber sheet or an electretized fiber sheet is folded into a zigzag shape to form a plate, or (2) a fiber sheet or an electretized fiber sheet is folded into a zigzag shape to form a plate. After that, it is further curved into a cylindrical shape, or (3) a fiber sheet or an electretized fiber sheet is sewn into a bag shape, or (4) a fiber sheet or an electretized fiber sheet is formed (for example, It can be thermoformed into a bowl shape.

Since the air filter of the present invention is provided with the above-described electret filter material in which the above-described electret filter material is fixed with a frame material, the filter efficiency, pressure loss, and charge life are reduced. Excellent in terms.

More specifically, a flat plate filter in which a flat plate electret filter material is fixed by a frame member, a bag filter in which one or more bag-shaped electret filter members are fixed by a frame member, or a zigzag fold. A fold filter in which a processed plate-shaped electret filter material is fixed with a frame material can be used.

The frame member can be made of, for example, aluminum, aluminum alloy, stainless steel, or various resins. Further, the fixing of the electret filter medium with the frame member can be carried out, for example, by interposing a thermoplastic hot melt resin such as polyvinyl acetate between the frame member and the electret filter medium.

As described above, the electret filter material and air filter of the present invention are excellent in filtering efficiency, pressure loss, and charge life, and therefore can be suitably used for applications such as air cleaners and masks. It can be used more specifically, as an air purifying filter for automobile interiors, an air purifying filter for automobile engines, an air purifying filter for buildings or residences, an air purifying filter for air conditioners, a dust mask, and the like.

Examples of the present invention will be described below, but the present invention is not limited to the following examples.

[0039]

Example 1 As a polyamine, a polyamine having a repeating structure represented by the following structural formula (II) (number average molecular weight: about 20,000, melting point: about 160 ° C.)
Of polypropylene added with 1 mass% (MI = 50
0) was prepared.

[Chemical 4] (In the formula, R ^{1 to} R ⁸ are all hydrogen, n is 0, and R ⁹ is a hexamethylene group)

Then, using this polypropylene, a non-woven fabric (unit weight = 45 g / m ² ,
Thickness = 0.7 mm, average fiber diameter: about 3 μm) was produced.

On the other hand, one surface of a rectangular stainless plate (= induction electrode, size: 200 mm × 300 mm) was sprayed with alumina to a thickness of 1 mm, and then,
Tungsten wires (wire diameter: 50 μm) were fixed at 10 mm intervals on the alumina sprayed surface using an alumina adhesive to prepare a discharge electrode. Further, a stainless plate (size: 300 mm × 300 mm) was prepared as a counter electrode arranged to face the discharge electrode.

Next, the tungsten wire and the facing surface of the counter electrode were placed 5 cm apart from each other so that the tungsten wire of the discharge electrode and the counter electrode face each other, and then the melt blown nonwoven fabric was placed on the counter electrode. .

Then, an alternating high voltage (frequency: 25 kHz) was applied between the stainless steel plate of the discharge electrode and the tungsten wire.
z, electric power: 100 W) to generate ions, and a high DC voltage (voltage: 20,000 V) is applied between the discharge electrode and the counter electrode at room temperature and atmospheric pressure to generate the ions. Was melted into the meltblown nonwoven fabric, and the electretization treatment was carried out for 10 seconds to produce an electretized meltblown nonwoven fabric, that is, a sheet-shaped electret filtration material.

(Embodiment 2) In exactly the same manner as in Embodiment 1,
A meltblown nonwoven was produced.

Next, 100 parts of this melt blown non-woven fabric is used.
10m / m supported by a mesh net (support)
in. While transporting at a speed of 1, the nozzle plate (nozzle diameter = 0.13
mm, nozzle pitch = 0.6 mm), a water stream ejected at 1 MPa from a nozzle is collided at room temperature under normal pressure, and then dried at room temperature to perform an electret treatment, which is an electret-meltblown nonwoven fabric, that is, a sheet-shaped electret. A filter medium was manufactured.

Example 3 As a polyamine, a polyamine having a repeating structure represented by the following structural formula (III) (number average molecular weight: about 20,000, melting point: about 145)
C.) polypropylene with 1 mass% added (MI = 5
No. 00) was used, and in the same manner as in Example 1, the meltblown nonwoven fabric (area weight = 45 g / m ² , thickness =
0.7 mm, average fiber diameter: about 3 μm) was manufactured, and this meltblown nonwoven fabric was subjected to electretization treatment in the same manner as in Example 1 to manufacture an electretized meltblown nonwoven fabric, that is, a sheet-shaped electret filtration material.

[Chemical 5] (In the formula, R ¹ , R ^{3 to} R ⁴ , and R ^{6 to} R ⁸ are hydrogen, R ² and R ⁵ are methyl groups, n is 0, and R ⁹ is a hexamethylene group)

Example 4 As a polyamine, a polypropylene (MI having 1 mass% of polyamine having a repeating structure represented by the following structural formula (IV) (number average molecular weight: about 8,000, melting point: about 290 ° C.) was added. = 500)
In the same manner as in Example 1 except that the melt-blown nonwoven fabric (unit weight = 45 g / m ² , thickness = 0.7) was used.
mm, average fiber diameter: about 3 μm), and the meltblown nonwoven fabric is subjected to electretization treatment in the same manner as in Example 1 to prepare an electretized meltblown nonwoven fabric,
That is, a sheet-shaped electret filter medium was manufactured.

[Chemical 6] (In the formula, R ^{1 to} R ⁸ are hydrogen, n is 1, R ⁹ and R ¹⁰ are methylene groups, and A is p-phenylene group)

(Comparative Example 1) In place of the polyamine of Example 1, a hindered amine light stabilizer (registered trademark: Kimasorb 944, manufactured by Ciba Specialty Chemicals Co.) was used at 1 ma.
A melt-blown nonwoven fabric (area weight = 45 g / m ² , thickness = 0.7 mm, average fiber diameter = about 3 μm) was prepared in the same manner as in Example 1 except that polypropylene containing ss% (MI = 500) was used. Manufactured. Then, the melt-blown nonwoven fabric was electretized in exactly the same manner as in Example 1 to produce a sheet-shaped electret filter material.

Comparative Example 2 A meltblown nonwoven fabric (area weight = 45 g / m ² , thickness) was prepared in the same manner as in Example 1 except that polypropylene (MI = 500) to which no polyamine was added was used. Thickness = 0.8 mm, average fiber diameter = about 3 μm). Then, the melt-blown nonwoven fabric was electretized in exactly the same manner as in Example 1 to produce a sheet-shaped electret filter material.

Comparative Example 3 A melt-blown nonwoven fabric produced in exactly the same manner as in Comparative Example 2 was subjected to electretization treatment in exactly the same manner as in Example 2 to produce a sheet-shaped electret filter material.

(Evaluation of dust collection performance and measurement of pressure loss) A wind speed of 10 cm / sec. Was applied to each of the electret filter media of Examples 1 to 4 and Comparative Examples 1 to 3. Atmosphere dust (particle diameter: 0.3 to 0.5 μm) was loaded, the number of dust before and after passing through the electret filter medium was measured, and the collection efficiency was calculated by the following formula. (Collection efficiency) = (B−A) / B Here, A means the number of dusts after passing through the filter medium, and B means the number of dusts before passing through the filter medium.

Further, the pressure loss before and after the electret filter medium at this time was measured to obtain the pressure loss.

Next, based on this collection efficiency and pressure loss, a 100γ value was calculated according to the following equation, and this 100γ value was used as an index of dust collection performance. The larger this 100γ value is,
Excellent dust collection performance. The results are shown in Table 1. (100γ) = − 100Log (1- (collection efficiency)) /
(Pressure loss)

(Evaluation of Thermal Stability) Each of the electret filter media of Examples 1 to 4 and Comparative Examples 1 to 3 was heated at a temperature of 1
It was left for 6 hours and 24 hours in a dryer set at 10 ° C. Then, 10 of each electret filter medium was prepared by the method described above (evaluation of dust collection performance and measurement of pressure loss).
The 0γ value was calculated. The results are shown in Table 1.

[Table 1]

As is clear from the results shown in Table 1, the electret filter material of the present invention was found to be excellent in filtering efficiency, pressure loss, and charge life.

[0056]

The electret filter material of the present invention is excellent in filtering efficiency, pressure loss, and charge life.

The air filter of the present invention is excellent in filtration efficiency, pressure loss, and charge life.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 23/00 C08L 23/00 79/04 79/04 Z (72) Inventor Hiroshi Tezuka Sowashima, Ibaraki Prefecture Mt. Kitatone, 7th in Nihon Bileen Co., Ltd. (72) Inventor, Toyofumi Dobata, Sowa-machi, Sarushima-gun, Ibaraki 7th Kitatone in Nihon Bileen, Inc. (72) Inventor Keiichi Fujii Higashi Oizumi, Nerima-ku, Tokyo 4-8-3 (72) Inventor Yasuyuki Suzuki 3-29-14 Higashi-Hatsutomi, Kamagaya-shi, Chiba F-Term (reference) 4D019 AA01 BA13 BB02 BB03 BB05 BC01 DA02 DA06 4F071 AA20 AA59 AA81 AF40 AH02 BA01 BB09 BC01 4J002 BB001 BB021 BB021 BB021 BB021 BB021 BB171 BC021 BD031 BD101 BD151 BG051 CK021 CM022 GD05 4J043 PA04 PC01 QB52 RA02 SA32 SA42 SB01 TA43 TA66 TB01 UA122 UA381 ZA12 ZA42 ZB13

Claims (9)

[Claims] 1. An electret filter material comprising a molded body containing a resin material containing a polyamine having a repeating structure represented by the following general formula (I). [Chemical 1] (In the formula, each of R ^{1 to} R ⁸ independently has 1 to 4 carbon atoms.
Represents an alkyl group or hydrogen, and n represents 0 or 1. When n is 0, R ⁹ represents an alkylene group having 4 to 15 carbon atoms which may have a substituent selected from the group consisting of an alkyl group having 1 to 4 carbon atoms and a phenyl group. When n is 1, A represents a phenylene group in which a hydrogen atom on the ring may be substituted with an alkyl group having 1 to 4 carbon atoms, and R ⁹ and R ¹⁰ are each independently the number of carbon atoms. It represents an alkylene group of 1 to 8, and the sum of the number of carbon atoms of the alkylene group of R ⁹ and R ¹⁰ is in the range of 2 to 9. ) 2. A polyamine having a repeating structure represented by the general formula (I), wherein at least one of R ¹ , R ² , R ⁷ and R ⁸ is a hydrogen atom, and R ³ and R ^{4 are} ,
The electret filter medium according to claim 1, wherein at least one of R ⁵ and R ⁶ is a hydrogen atom. 3. The electret filter medium according to claim 1, wherein R ^{1 to} R ^{8 of the} polyamine having a repeating structure represented by the general formula (I) are all hydrogen atoms. 4. The polyamine having a repeating structure represented by the general formula (I) has a number average molecular weight of 500 to 10.
The electret filter medium according to any one of claims 1 to 3, which is in the range of 10,000. 5. The content of the polyamine having a repeating structure represented by the general formula (I) is 0.01 to 5 mass% of the entire resin material, and the content of the polyamine is 0.01 to 5 mass%. Electret filter material. 6. The electret filter medium according to claim 1, wherein the resin material is a polyolefin resin. 7. The electret filter medium according to claim 1, wherein the molded body is a fiber sheet. 8. The electret filter medium according to claim 1, wherein the molded body is composed of a melt blown nonwoven fabric. 9. An air filter comprising the electret filter medium according to claim 1. Description: