JP2001210549A - Electlet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electlet having high electric charge density on the surface under normal or high temperature and with superior holding ability of the electric charge density, especially to provide an electlet with superior collecting ability for collecting minute dust or the like, when it is used for air filter. SOLUTION: This electlet is a resin composition having a specific cyclic hydrocarbon base polymer (A) and denatured high polymer compound (B), which is subjected to graft copolymerization is co-polymerized to a high polymer compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electret,
In particular, the present invention relates to an electret having high performance such as high surface charge density and excellent surface charge density retention at high temperatures.

[0002]

BACKGROUND ART Electrets have been widely used in various applications such as materials for audio equipment such as microphones, pickups and speakers; electronic copying and printing; and medical materials. Electrets are used in various forms, such as films, sheets, fibers, and nonwoven fabrics, depending on the usage. In particular, electret filters formed by processing electrets are widely used for applications such as air filters. When an electret filter is used for an air filter of an automobile, charge retention at high temperatures is required.

Conventionally, non-polar polymer compounds such as polypropylene, polar polymer compounds such as polycarbonate, and modified non-polar polymer compounds graft-modified with a polar group-containing compound such as maleic anhydride have been blended as electrets. (JP-B-59-23098, JP-A-60-2).
No. 25416).

[0004] However, such an electret has a problem that the surface charge density is not sufficient depending on the use, and the retention of the surface charge density at a high temperature is not sufficient.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has an electret having a high charge density at any of room temperature or high temperature and having excellent surface charge density retention properties. The purpose is to provide.

[0006]

SUMMARY OF THE INVENTION The electret of the present invention comprises at least one cyclic hydrocarbon polymer (A) selected from the group consisting of (I), (II), (III), (IV) and (V). And a modified polymer compound (B) obtained by graft copolymerizing a modified monomer with a polymer compound. (I) a (co) polymer of a vinyl monocyclic alicyclic hydrocarbon compound, or a copolymer of a vinyl monocyclic alicyclic hydrocarbon compound and a monomer copolymerizable therewith, or (II) a hydrogenated product of a (co) polymer of a vinyl aromatic hydrocarbon compound or a copolymer of a vinyl aromatic hydrocarbon compound and a monomer copolymerizable therewith; A hydrogenated product of a polymer, wherein at least 30% of an aromatic hydrocarbon ring is hydrogenated; (III) a (co) polymer of a monocyclic monoolefin compound, or a monocyclic cyclic compound A copolymer of a monoolefin-based compound and a monomer copolymerizable therewith; (IV) a hydrogenated product of a (co) polymer of a monocyclic conjugated diene-based compound, or a monocyclic conjugated diene-based compound Hydrogenated product of a copolymer of a compound and a monomer copolymerizable therewith; V) converting at least one cyclic hydrocarbon polymer selected from the group consisting of (I), (II), (III) and (IV) with an α, β-unsaturated carboxylic acid, an anhydride thereof, or an anhydride thereof; Modified product obtained by graft modification with a derivative.

[0007]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the present invention will be described specifically. The resin composition constituting the electret of the present invention contains a cyclic hydrocarbon polymer (A) and a modified polymer compound (B).

Cyclic hydrocarbon polymer (A) The cyclic hydrocarbon polymer (A) which is the component (A) constituting the electret of the present invention includes the following (I), (II) and (I)
It is a resin containing at least one type of cyclic hydrocarbon polymer selected from the group consisting of II), (IV) and (V). (I) a (co) polymer of a vinyl monocyclic alicyclic hydrocarbon compound, or a copolymer of a vinyl monocyclic alicyclic hydrocarbon compound and a monomer copolymerizable therewith, or (II) a hydrogenated product of a (co) polymer of a vinyl aromatic hydrocarbon compound or a copolymer of a vinyl aromatic hydrocarbon compound and a monomer copolymerizable therewith; A hydrogenated product of a polymer, wherein at least 30% of an aromatic hydrocarbon ring is hydrogenated; (III) a (co) polymer of a monocyclic monoolefin compound, or a monocyclic cyclic compound A copolymer of a monoolefin-based compound and a monomer copolymerizable therewith; (IV) a hydrogenated product of a (co) polymer of a monocyclic conjugated diene-based compound, or a monocyclic conjugated diene-based compound Hydrogenated product of a copolymer of a compound and a monomer copolymerizable therewith; V) converting at least one cyclic hydrocarbon polymer selected from the group consisting of (I), (II), (III) and (IV) with an α, β-unsaturated carboxylic acid, an anhydride thereof, or an anhydride thereof; Modified product obtained by graft modification with a derivative.

Here, the above-mentioned polymers (I), (II), (III), (IV) and (V) which can be used as the cyclic hydrocarbon polymer (A) used in the present invention. explain.

The polymer (I) may be (I) a (co) polymer of a vinyl monocyclic alicyclic hydrocarbon compound or a vinyl monocyclic alicyclic hydrocarbon compound and copolymerizable therewith. Or a hydrogenated product thereof.

The vinyl monocyclic alicyclic hydrocarbon compound is
A compound having a structure in which a monocyclic cycloalkyl group or a monocyclic cycloalkenyl group is bonded to a vinyl group or an α-alkyl-substituted vinyl group. Here, the monocyclic cycloalkyl group and cycloalkenyl group may have a substituent such as an alkyl group.

Examples of such compounds include vinylcyclobutane, vinylcyclopentane, vinylcyclohexane, vinylcycloheptane, vinylcyclooctane, and those compounds in which the α-position of the vinyl group is substituted with an alkyl group such as methyl, ethyl, or propyl. Compounds can be exemplified. Also, 4-vinylcyclohexene, 4-isopropenylhexene, 1-methyl-4-vinylcyclohexene, 1-methyl-4-isopropenylcyclohexene,
2-methyl-4-vinylcyclohexene, 2-methyl-
Examples thereof include vinylcyclohexene derivatives such as 4-isopropenylhexene.

When the polymer (I) is a (co) polymer of a vinyl monocyclic alicyclic hydrocarbon compound, these vinyl monocyclic alicyclic hydrocarbon compounds are polymerized alone. Or a copolymer obtained by copolymerizing two or more kinds.

When the polymer (I) is a copolymer of a vinyl-based monocyclic alicyclic hydrocarbon compound and a monomer copolymerizable therewith, these vinyl-based alicyclic hydrocarbon compounds may be used. The copolymer is a copolymer obtained by combining a monocyclic alicyclic hydrocarbon compound with another compound copolymerizable with the compound within a range that does not impair the purpose of the present invention.

As the monomer copolymerizable with the vinyl monocyclic alicyclic hydrocarbon compound, any copolymerizable monomer can be used, and propylene, butene, acrylonitrile, acrylic acid, methacrylic acid, Maleic anhydride, acrylic acid ester, methacrylic acid ester, maleimide, vinyl acetate, vinyl chloride and the like can be exemplified. Among these monomers, it is preferable to use an α-olefin, and particularly, it is preferable to use a monomer such as propylene or butene because flexibility and impact resistance can be imparted. Such a monomer copolymerizable with the vinyl-based monocyclic alicyclic hydrocarbon compound is 0 to 9 based on the total amount of the monomer.
It is desirable to use 5 mol%, more preferably 0 to 90 mol%.

There is no particular limitation on the polymerization method for obtaining these polymers or copolymers, and any known radical polymerization,
Coordination anionic polymerization (Ziegler polymerization), cationic polymerization,
A polymerization method such as anionic polymerization can be applied.

The polymer (I) may be a hydrogenated product of these polymers or copolymers. In particular, when a vinyl-based monocyclic alicyclic hydrocarbon compound used as a monomer forming these polymers or copolymers is substituted with a vinyl group or an α-alkyl-substituted vinyl group, a monocyclic (alkyl-substituted) cyclo In the case of a compound having a structure in which an alkenyl group is bonded, the above-mentioned polymer or copolymer is preferably a hydrogenated product. As such a hydrogenated product, 30% or more, preferably 60% or more, more preferably 90% or more of the optionally substituted cycloalkenyl group in the polymer or copolymer is hydrogenated. A polymer consisting of

The polymer (II) is a hydrogenated product of a (co) polymer of a vinyl aromatic hydrocarbon compound or a vinyl aromatic hydrocarbon compound and a monomer copolymerizable therewith. Which is a hydrogenated product of at least 30% of the aromatic hydrocarbon ring.

The vinyl aromatic hydrocarbon compound used as a monomer for forming the polymer (II) is a compound in which an aromatic substituent is bonded to a vinyl group or an α-alkyl-substituted vinyl group. . Such compounds include styrene, α-methylstyrene, α-ethylstyrene, α
-Propylstyrene, α-isopropylstyrene, α-
t-butylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-t-butylstyrene, 5-t-butyl-2-methylstyrene , Monochlorostyrene, dichlorostyrene, monofluorostyrene, 4-phenylstyrene, vinylnaphthalene, vinylanthracene and the like.

When the polymer (II) is a hydrogenated (co) polymer of a vinyl aromatic hydrocarbon compound, such a vinyl aromatic hydrocarbon compound is polymerized alone. It may be a hydrogenated product of a polymer or a hydrogenated product of a copolymer obtained by copolymerizing two or more kinds.

In the case where the polymer (II) is a hydrogenated product of a copolymer of a vinyl aromatic hydrocarbon compound and a monomer copolymerizable therewith, It is a hydrogenated product of a copolymer in which a vinyl aromatic hydrocarbon compound and a monomer copolymerizable with the compound are copolymerized in a range that does not impair the gist of the present invention. As the monomer copolymerizable with such a vinyl aromatic hydrocarbon compound, any copolymerizable monomer can be used, and propylene, butene, acrylonitrile, acrylic acid, methacrylic acid, and maleic anhydride can be used. Acrylate, methacrylate, maleimide, vinyl acetate, vinyl chloride and the like. Among these monomers, it is preferable to use an α-olefin, and particularly, it is preferable to use a monomer such as propylene or butene because flexibility and impact resistance can be imparted. Such a monomer copolymerizable with the vinyl aromatic hydrocarbon compound is used in a proportion of 0 to 95 mol%, more preferably 0 to 90 mol%, based on the total amount of the monomers. desirable.

Such a polymer or copolymer of the above (II) can be obtained by polymerizing in the same manner as the polymer of the above (I) and hydrogenating it by a known method.

As the hydrogenation method, for example, the methods described in JP-A-7-247321 and US Pat. No. 5,612,422 can be exemplified. The hydrogenation rate of the aromatic hydrocarbon ring contained in the polymer (II) is 30% or more, preferably 60% or more, more preferably 90% or more.

The polymer (III) is a (co) polymer of a monocyclic monoolefin compound or a copolymer of a monocyclic monoolefin compound and a monomer copolymerizable therewith. It is.

The monocyclic monoolefinic compound used as a monomer for forming the polymer of (III) is a monocyclic monoolefin which may have a substituent, and may be cyclobutene or cyclopentene. , Cyclohexene,
Cyclooctene and the like can be mentioned.

When the polymer of the above (III) is a (co) polymer of a monocyclic monoolefin compound, it is a polymer obtained by polymerizing such a monocyclic monoolefin compound alone. Alternatively, a polymer obtained by copolymerizing two or more kinds may be used.

In the case where the polymer (III) is a copolymer of a monocyclic monoolefin compound and a monomer copolymerizable therewith, the above monocyclic monoolefin may be used. The copolymer is a copolymer in which a system compound and another compound copolymerizable with the compound are combined in a range that does not impair the purpose of the present invention.

As the monomer copolymerizable with the monocyclic monoolefin compound, any copolymerizable monomer can be used, and ethylene, propylene, butene,
Examples thereof include acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride, acrylic ester, methacrylic ester, maleimide, vinyl acetate, and vinyl chloride. Such a monomer copolymerizable with the monocyclic monoolefin compound is used at a ratio of 0 to 95 mol%, more preferably 0 to 90 mol%, based on the total amount of the monomers. desirable.

The polymerization method for obtaining these polymers or copolymers is not particularly limited, and can be obtained by a known method in which a monomer containing a cyclic monoolefin compound is addition-polymerized.

The polymer (IV) is a hydrogenated product of a (co) polymer of a monocyclic conjugated diene compound or a monocyclic conjugated diene compound and a monomer copolymerizable therewith. Is a hydrogenated product of the copolymer

The monocyclic conjugated diene compound used as a monomer for forming the polymer (IV) is a monocyclic conjugated diene which may have a substituent, and may be cyclopentadiene, cyclopentadiene or cyclopentadiene. Hexadiene, cycloheptadiene, cyclooctadiene and the like can be mentioned.

In the case where the polymer (IV) is a hydrogenated product of a (co) polymer of a monocyclic conjugated diene compound, such a monocyclic conjugated diene compound was polymerized alone. It may be a hydrogenated product of a polymer or a hydrogenated product of a copolymer obtained by copolymerizing two or more kinds.

When the polymer (IV) is a hydrogenated product of a copolymer of a monocyclic conjugated diene compound and a monomer copolymerizable therewith, It is a hydrogenated product of a copolymer obtained by combining a monocyclic conjugated diene compound and a monomer copolymerizable with the compound in a range that does not impair the gist of the present invention.

As the monomer to be copolymerized with such a monocyclic conjugated diene compound, any copolymerizable monomer can be used, and ethylene, propylene, butene, acrylonitrile, acrylic acid, Examples thereof include methacrylic acid, maleic anhydride, acrylic acid ester, methacrylic acid ester, maleimide, vinyl acetate, and vinyl chloride. Such a monomer copolymerizable with the monocyclic conjugated diene-based compound is preferably used in a ratio of 0 to 95 mol%, more preferably 0 to 90 mol%, based on the total amount of the monomers. .

Such a polymer or copolymer of the above (IV) is subjected to addition polymerization of the above-mentioned monomer containing a monocyclic conjugated diene compound by a known method, and hydrogenated by a known method. Can be obtained by:

Specifically, for example, polycyclohexadiene and a hydrogenated product thereof can be obtained by using the method disclosed in JP-A-11-106571. The hydrogenation rate of the double bond in the hydrocarbon ring contained in the polymer or copolymer of the above (IV) is 30.
% Or more, preferably 60% or more, more preferably 90%
It is desirable that this is the case.

The above (I), (II), (III) and
And (IV) cyclic hydrocarbon polymers are gel permeation
Weight average molecular weight by molecular chromatography (GPC)
The amount (Mw) is usually 5,000-
1,000,000, preferably 10,000-50
0000, more preferably 50,000 to 300,0
00 is desirable. Also, the molecular weight distribution Mw / Mn
Is usually 10 or less, preferably 5.0 or less, more preferably
Or 3.0 or less, and the glass transition
The temperature is usually 50 to 300 ° C, preferably 60 to 280.
° C, more preferably in the range of 70-250 ° C,
The degree of conversion is usually 20% or less, preferably 10% or less, more
Preferably, it is 5% or less. Also the density
Is 1.5 g / cm^ThreeOr less, preferably 1.0 g / cm^Three
Or less, more preferably 0.95 g / cm ^ThreeIs the following
Is desirable.

[0038] The polymer (V) may be any of the above (I), (II),
A modified product obtained by graft-modifying at least one cyclic hydrocarbon polymer selected from the group consisting of (III) and (IV) with an α, β-unsaturated carboxylic acid, an anhydride thereof or a derivative thereof; is there.

The polymer (V) is obtained by subjecting such a cyclic hydrocarbon polymer before modification to a graft modification using a graft monomer. As the graft monomer,
For example, α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid and nadic acid, or acid anhydrides or derivatives thereof Can be used. As the derivative, for example,
Acid halides, amides, imides, esters and the like. Specific examples of such anhydrides or derivatives include maleenyl chloride, maleenyl imide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate, and the like. Among these, unsaturated dicarboxylic acids or acid anhydrides thereof are preferable, and maleic acid, nadic acid or acid anhydrides thereof are particularly preferable.

The graft ratio of the graft monomer in the preparation of the polymer (V) is 0.00 per 1 g of the cyclic hydrocarbon polymer selected from (I) to (IV).
1 to 0.04 mg equivalent, preferably 0.005 to 0.03
Desirably, it is in the range of mg equivalent.

As the graft monomer, a modifier used in epoxy modification, such as glycidyl methacrylate (GMA), allyl glycidyl ether, vinyl glycidyl ether, glycidyl, instead of the above-mentioned α, β-unsaturated carboxylic acid, etc. A glycidyl compound such as itaconate can also be used.

Using such a graft monomer,
In order to produce the polymer (V), various conventionally known methods can be used. As such a method, for example, a method in which a cyclic hydrocarbon-based polymer selected from the above (I) to (IV) is melted by heating and a graft monomer is added to carry out graft copolymerization, or the above-described (I) )
And a method of dissolving a cyclic hydrocarbon polymer selected from (IV) in a solvent, adding a graft monomer, and performing graft copolymerization.

The graft copolymerization reaction is preferably performed in the presence of a radical initiator because of high reaction efficiency. Examples of the radical initiator used in the graft copolymerization reaction include organic peroxides, organic peresters, and other azo compounds. Among these radical initiators, dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3,
Dialkyl peroxides such as 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane and 1,4-bis (tert-butylperoxyisopropyl) benzene are preferred. Such radical initiators are described in (I) to (I) above.
It is desirable to use 0.001 to 1 part by weight based on 100 parts by weight of the cyclic hydrocarbon polymer selected from V).

Such a graft copolymerization reaction is usually carried out in 6
It is performed in a temperature range of 0 to 380 ° C. Such (V)
Has a weight average molecular weight of 10,000 to 50.
0000, preferably 20,000 to 300,
000, more preferably 50,000 to 300,000
Desirably.

Modified polymer compound (B) (B) of the resin composition constituting the electret of the present invention
The modified polymer compound (B), which is a component, is obtained by modifying a polymer compound by graft copolymerization with a modified monomer.

The pre-modified polymer compound forming the modified polymer compound (B) may be an ordinary non-polar polymer compound, and is not particularly limited. As this polymer compound, for example,
The above-mentioned cyclic hydrocarbon polymer (A), a homopolymer of an α-olefin, a copolymer of two or more α-olefins, or at least two or more selected from these homopolymers and copolymers And mixtures thereof.

Examples of the α-olefin include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, isopentene, 4-methyl-1-pentene, 3-
Methyl-1-pentene, 1-octene, 1-decene, 1
-Hexadecene, 1-octadecene, 1-eicosene and the like. Specific examples of the polymer compound include propylene, ethylene, polyethylene, polypropylene, poly-1-butene, poly-4-methyl-1-pentene, ethylene / propylene copolymer, ethylene / 1-butene copolymer, ethylene・ 4-methyl-1-pentene copolymer, propylene / 1-butene copolymer, 4-methyl-1
-Pentene / 1-decene copolymer and the like.

As the modifying monomer, unsaturated carboxylic acids and derivatives thereof are preferably used. For example, acrylic acid, methacrylic acid, α-ethylacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid Acid, methyltetrahydrophthalic acid, endocis-bicyclo [2,2,1] hept-5-ene-2,3
-Dicarboxylic acid (nadic acid), methyl-endosis-
Unsaturated dicarboxylic acids such as bicyclo [2,2,1] hept-5-ene-2,3-dicarboxylic acid (methylnadic acid), and derivatives of these unsaturated dicarboxylic acids as derivatives of these unsaturated dicarboxylic acids Examples include acid halides, amides, imides, acid anhydrides, esters and the like. Specific examples of the derivative of the unsaturated dicarboxylic acid include maleenyl chloride, maleimide, maleic anhydride, citraconic anhydride, monomethyl maleate, dimethyl maleate and the like. These unsaturated carboxylic acids and derivatives thereof may be used alone or in combination of two or more.
Among these, unsaturated dicarboxylic acids and acid anhydrides thereof are preferable, and maleic acid, nadic acid and acid anhydrides thereof are particularly preferable.

As the modifying monomer, a modifying agent used in epoxy modification, such as glycidyl methacrylate (GM), may be used in place of the above unsaturated carboxylic acid.
A), glycidyl compounds such as allyl glycidyl ether, vinyl glycidyl ether and glycidyl itaconate can also be used.

These modified monomers may be used alone or in combination of two or more. In the modified polymer compound (B), the content of such a modified monomer, that is, the graft amount of the modified polymer compound is usually 0.0%.
5 to 15% by weight, preferably 0.1 to 5% by weight,
More preferably 0.1 to 4% by weight, most preferably 0.1 to 4% by weight.
Preferably, it is 5 to 3% by weight.

The method for producing the modified polymer compound (B) is not particularly limited, and it can be produced according to a conventional method. For example, according to a method such as a method in which a polymer compound is melted and a modified monomer is added to perform graft copolymerization, or a method in which the polymer compound is dissolved in a solvent and a modified monomer is added and copolymerized. It can be carried out.

In any of the methods, it is preferable to carry out the copolymerization reaction in the presence of a radical polymerization initiator since the graft copolymerization can be carried out efficiently. Examples of the radical polymerization initiator used include organic peroxides, organic peresters, and azo compounds. Radical generation may be promoted by irradiation with ionizing radiation, ultraviolet light, or the like.

In particular, when the modified polymer compound (B) is a modified product of the above-mentioned cyclic hydrocarbon polymer (A), dicumyl peroxide and di-tert-butyl peroxide are among these radical initiators. , 2,5-dimethyl-
2,5-di (tert-butylperoxy) hexyne-3,2.5
Dialkyl peroxides such as -dimethyl-2,5-di (tert-butylperoxy) hexane, 1,4-bis (tert-butylperoxyisopropyl) benzene are preferred. Such a radical initiator is used in an amount of 0.001 to 100 parts by weight based on the cyclic hydrocarbon polymer (A) before modification.
It is desirable to use 1 part by weight. Such a graft copolymerization reaction of the cyclic hydrocarbon polymer (A) is usually performed in a temperature range of about 60 to 380 ° C.

Resin Composition In the resin composition constituting the electret of the present invention, the content ratio of the cyclic hydrocarbon polymer (A) and the modified polymer compound (B) is not particularly limited. The ratio of the modified polymer compound (B) is preferably 0.5 to 40 parts by weight, and more preferably 2 to 15 parts by weight, per 100 parts by weight of the hydrocarbon polymer (A).

Further, the resin composition constituting the electret of the present invention may contain other resins in addition to the cyclic hydrocarbon polymer (A) and the modified polymer compound (B). When the resin composition contains another resin, it is preferable that the other resin is finely dispersed in the cyclic hydrocarbon-based polymer (A) to form a so-called polymer alloy.

Other resins that may be contained in the resin composition constituting the electret of the present invention include, for example, the following (1) to (17). (1) A polymer derived from a hydrocarbon having one or two unsaturated bonds. Specific examples include polyolefins such as polyethylene, polypropylene, polymethylbutene-1, poly4-methylpentene-1, polybutene-1, and polystyrene. These polyolefins may have a crosslinked structure. (2) A halogen-containing vinyl polymer. Specific examples include polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride,
Examples thereof include polychloroprene, polytetrafluoroethylene, ethylene tetrafluoride / propylene hexafluoride copolymer, and chlorinated rubber. (3) Polymers derived from α, β-unsaturated acids and their derivatives. As specific examples, polyacrylate, polymethacrylate, polyacrylamide, polyacrylonitrile,
Alternatively, a copolymer with a monomer constituting the above-mentioned polymer (eg, acrylonitrile-butadiene-styrene copolymer, acrylonitrile-styrene copolymer, acrylonitrile-styrene-acrylate copolymer) and the like can be mentioned. . (4) Polymers derived from unsaturated alcohols, amines, their acyl derivatives or acetal. As a specific example,
Polyvinyl alcohol, polyvinyl acetate, poly (vinyl sulphate), poly (vinyl benzoate), poly (vinyl maleate), polyvinyl butyral, polyallyl phthalate, polyallyl melamine, or a copolymer with a monomer constituting the polymer (eg, ethylene, acetic acid Vinyl copolymer)
And the like. (5) A polymer derived from an epoxide. Specific examples include polymers derived from polyethylene oxide or bisglycidyl ether. (6) Polyacetal. Specific examples include polyoxymethylene, polyoxyethylene, and polyoxymethylene containing ethylene oxide as a comonomer. (7) Polyphenylene oxide. (8) Polycarbonate. (9) Polysulfone. (10) Polyurethane and urea resins. (11) diamine and dicarboxylic acid, aminocarboxylic acid,
Or polyamides and copolyamides derived from the corresponding lactams. Specific examples include nylon 6, nylon 66, nylon 11, nylon 12, and the like. (12) Polyesters derived from dicarboxylic acids, dialcohols, oxycarboxylic acids or corresponding lactones. As specific examples, polyester terephthalate, polybutylene terephthalate, poly 1,4-dimethylol
Cyclohexane terephthalate and the like can be mentioned. (13) A polymer having a crosslinked structure derived from aldehyde and phenol, urea or melamine. Specific examples include phenol / formaldehyde resin, urea / formaldehyde resin, melamine / formaldehyde resin, and the like. (14) Alkyd resin. As a specific example, glycerin
A phthalic acid resin can be used. (15) derived from a copolyester that is a copolymer of a saturated or unsaturated dicarboxylic acid and a polyhydric alcohol,
Unsaturated polyester resins obtained by using a vinyl compound as a crosslinking agent, and halogen-containing modified resins. (16) Natural polymers. Specific examples include cellulose, rubber, proteins, and derivatives thereof (eg, cellulose acetate, cellulose propionate, cellulose ether).
And the like. (17) Soft polymer. Specifically, the following (i)
And rubbery components selected from the group of (iv). (I) α-olefin-based copolymer The α-olefin-based copolymer (ii) used as the soft polymer comprises at least two kinds of α-olefins,
It is an amorphous or low crystalline copolymer. Specific examples include ethylene / α-olefin copolymer, propylene /
α-olefin copolymers and the like.

As the α-olefin constituting the ethylene / α-olefin copolymer, those having 3 to 20 carbon atoms are usually used. Specific examples thereof include propylene, 1-butene, 4-methyl-1-butene, Examples thereof include α-olefins such as 1-hexene, 1-octene, 1-decene and the like, and mixtures thereof. Among them, α-olefins having 3 to 10 carbon atoms are particularly preferable.

The ethylene / α-olefin molar ratio in the ethylene / α-olefin copolymer is usually 40/60.
９５95/5. When the α-olefin is propylene, it is preferably 40/60 to 90/10, and when the α-olefin has 4 or more carbon atoms, it is 50/50 to 95/5. Is preferred.

As the α-olefin constituting the propylene / α-olefin copolymer, those having 4 to 20 carbon atoms are usually used, and specific examples are 1-butene, 4-methyl-1-butene, 1-butene and 1-butene. Α-olefins such as hexene, 1-octene and 1-decene, and mixtures thereof. Among them, α-olefins having 4 to 10 carbon atoms are particularly preferable.

The propylene / α-olefin copolymer has a propylene / α-olefin molar ratio of usually 50/50 to 95/5. (Ii) α-olefin / diene copolymer The α-olefin / diene copolymer (ii) used as the soft polymer includes ethylene / α-olefin /
Diene copolymer rubber, propylene / α-olefin / diene copolymer rubber and the like can be mentioned.

The α-olefin constituting these copolymer rubbers is, for example, an α-olefin having 3 to 20 carbon atoms (4 to 20 in the case of propylene / α-olefin), specifically, propylene, Examples thereof include 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, and mixtures thereof. Of these, α-olefins having 3 to 10 carbon atoms are preferred.

Further, as the diene component constituting these copolymer rubbers, for example, 1,4-hexadiene,
Chain non-conjugated dienes such as 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, cyclohexadiene, dicyclopentadiene, Cyclic such as methyltetrahydroindene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropylenyl-2-norbornene Non-conjugated diene, 2,3-diisopropylidene-5
-Norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene and the like.

The ethylene / α-olefin molar ratio in the ethylene / α-olefin / diene copolymer rubber is usually 40/60 to 90/10. In these copolymer rubbers, the content of the repeating structural unit derived from the diene component is usually 1 to 20 mol%,
Preferably it is 2 to 15 mol%. (Iii) Aromatic vinyl hydrocarbon / conjugated diene soft copolymer Aromatic vinyl hydrocarbon used as a soft polymer
The conjugated diene-based soft copolymer is a random copolymer, a block copolymer or a hydride thereof of an aromatic vinyl-based hydrocarbon and a conjugated diene. Specific examples include styrene / butadiene block copolymer rubber and styrene / butadiene block copolymer rubber.
Butadiene / styrene block copolymer rubber, styrene / isoprene block copolymer rubber, styrene / isoprene / styrene block copolymer rubber, hydrogenated styrene / butadiene / styrene block copolymer, hydrogenated styrene / isoprene / styrene block copolymer Polymer rubber, styrene / butadiene random copolymer rubber and the like can be mentioned.

The molar ratio of aromatic vinyl hydrocarbon / conjugated diene in these copolymer rubbers is usually 10/9
0 to 70/30. Further, the hydrogenated copolymer rubber is a copolymer rubber obtained by hydrogenating a part or all of the double bonds remaining in the above-mentioned copolymer rubber.

(Iv) isobutylene or isobutylene
Soft polymer or copolymer comprising conjugated diene Specific examples of the isobutylene-based soft polymer or copolymer (iv) include polyisobutylene rubber, polyisoprene rubber, polybutadiene rubber, isobutylene / isoprene copolymer rubber, and the like. No.

The characteristics of the soft polymers (i) to (iv) are as follows: the intrinsic viscosity [η] measured in decalin at 135 ° C. is usually 0.01 to 10 dl / g; It is preferably in the range of 0.08 to 7 dl / g, and the glass transition temperature (Tg) is usually 0 ° C or lower, preferably -10 ° C.
The temperature is particularly preferably -20 ° C or lower. The crystallinity measured by the X-ray diffraction method is usually 0 to 10%,
Preferably it is in the range of 0-7%, particularly preferably 0-5%.

The resin composition for forming an electret of the present invention is obtained by blending another resin besides the cyclic hydrocarbon polymer (A) and the modified polymer compound (B) to obtain a cyclic hydrocarbon polymer (A). ) And another resin to form a polymer alloy, and when the above-mentioned (17) flexible polymer (i) to (iv) is used as the other resin, the flexible polymer is a cyclic hydrocarbon-based resin. Usually, 5 to 150 parts by weight, preferably 5 to 10 parts by weight, per 100 parts by weight of the polymer (A).
When used in an amount of 0 parts by weight, particularly preferably 10 to 80 parts by weight, the obtained electret has a good balance of properties such as impact strength, rigidity, heat deformation temperature and hardness.

In addition to the cyclic hydrocarbon polymer (A) and the modified polymer compound (B), if necessary, compounding agents such as a heat stabilizer, a weather stabilizer, a slip Agents, anti-blocking agents, lubricants, inorganic or organic fillers, dyes, pigments and the like.

In the production of this resin composition, the cyclic hydrocarbon polymer (A) and the modified polymer compound (B), and other resins and other additives blended as required, are mixed with a known resin. Mixing can be performed using the method. For example, each component can be mixed simultaneously.

Electret The electret of the present invention can be made into various forms by using such a resin composition as a raw material, molding into various forms, and performing electret treatment.

The electretization process is not particularly limited, and can be performed according to various known methods. For example, a method in which the resin composition is heated until it melts or softens, and cooled while applying a high DC voltage to form an electret (thermal electretization method); after the resin composition is formed into a film, A method of applying corona discharge or pulsed high voltage, or holding both surfaces of a film with a dielectric, and applying a DC high voltage to both surfaces to form an electret (electro-electret method); (Radio electret conversion method). More specifically,
After forming the resin composition into a film shape, a method of applying corona discharge while stretching as necessary, a method of sandwiching the film between a pair of needle-like electrodes and performing corona discharge, and the like can be given. When performing stretching, it may be uniaxial stretching or biaxial stretching.

For example, when the electret of the present invention is manufactured by corona discharge, it is usually 10 × 1
It has a surface charge density of about 0 ^-9 to 50 × 10 ^-9 C (coulomb) / cm ² , preferably about 20 × 10 ^-9 to 40 × 10 ^-9 C / cm ² .

The electret of the present invention can be in various forms, and the form can be appropriately selected according to the application, the usage mode, and the like. For example, various forms such as a film, a sheet, a fiber, and a nonwoven fabric can be used.

For example, a non-woven fabric formed from the above resin composition is formed into an electret by a melt blow method.
It is manufactured by electretizing a nonwoven fabric obtained by a known synthetic resin nonwoven fabric manufacturing method such as a spun bond method. In the present invention, a nonwoven fabric (melt blow method) is formed by forming discontinuous fibers having a fine fiber diameter from a resin composition and accumulating the fibers on a porous support, and then the obtained nonwoven fabric is electretized. Is preferred. Hereinafter, an example of producing an electret nonwoven fabric by a melt blow method will be described more specifically.

First, the resin composition is supplied to an extruder or the like, heated and melted and kneaded, and extruded as a fine resin flow from a melt blow die having a large number of pores. The extruded resin stream is contacted with a high-speed heated gas stream, cooled and solidified to form discontinuous fibers having a fine fiber diameter. The melting and kneading of the resin composition is desirably performed at a temperature such that the resin composition does not have a low molecular weight due to thermal decomposition and has a melt viscosity suitable for melt molding. It is desirable to carry out at a temperature of 380 ° C.

The die width of the melt blow die is usually 1
000 to 2000 mm, the tip lip has many pores, usually 800 to 300 mm.
Zero holes are drilled. The diameter of this hole is usually 0.5
mm. The molten resin stream is preferably extruded from the die at a discharge rate of usually about 10 to 130 kg / hr.

The fine resin flow extruded from the die as described above is split by contacting with a high-speed heated gas flow, is drafted in a molten state, and is stretched in the fiber length direction to further increase the fiber diameter. It is refined and formed into fine discontinuous fibers. To blow a heated gas stream onto the resin stream,
The resin flow may be extruded while blowing the heated gas flow from an outlet provided inside the die tip lip portion, or the heated gas flow may be blown from the outside of the lip portion to the resin flow extruded from the die. . This heating gas may be air or an inert gas. The temperature of the heated gas stream is usually 20
The temperature is desirably 0 to 360 ° C, particularly 230 to 330 ° C. The heated gas flow is preferably sprayed at a flow rate of usually 100 to 3500 m ³ / hr, particularly 200 to 3200 m ³ / hr.

The above-mentioned fine discontinuous fibers are then accumulated on a porous support to form a web-like melt-blown nonwoven fabric. As the porous support, for example, a network structure formed of stainless steel, polyester, or the like can be used.

The basis weight of the nonwoven fabric is usually 5 to 100 g / m
^{2 It is} particularly desirable to be 10 to 80 g / m ² . With such a basis weight, it is possible to obtain a nonwoven fabric which has appropriate air permeability, has no local variation in the basis weight and is excellent in strength. When the average fiber diameter was determined as the average value of any 30 fiber diameters measured on an electron micrograph (500 times) of the surface of the nonwoven fabric, the average fiber diameter of the fibers forming the nonwoven fabric was 0.5 -10μm, especially 1-6μ
m and the fiber length are desirably about 50 to 400 mm. The non-woven fabric formed from the above-mentioned fibers has excellent air permeability and also excellent dust collecting properties for fine dust.

The bulk density of the nonwoven fabric is preferably 0.05 to 0.40 g / cm from the viewpoints of strength, ease of handling and air permeability.
^{3 It is} particularly desirable that the amount is 0.06 to 0.20 g / cm ³ . The thickness of the nonwoven fabric is determined by the basis weight and the bulk density, and is usually 0.1 to 5 mm, particularly 0.1 to 0.6 mm.
It is desirable that The intrinsic viscosity [η] of the resin composition (fiber) forming the nonwoven fabric is 0.30 to 0.40 dl /
g is desirable.

When the electret according to the present invention is in the form of a nonwoven fabric, it can be obtained by subjecting the thus obtained nonwoven fabric to an electret treatment by the method described above. For example, when a DC voltage is not applied to the nonwoven fabric, the DC voltage value is appropriately selected depending on the shape of the electrode to be used, the distance between the electrodes, the processing speed, the desired charge amount, and the like. In this case, it is desirable to apply a DC voltage of at least -10 kV, preferably -15 to -30 kV, to the nonwoven fabric. In the present invention, the average surface charge density (amount) of the electret composed of such a nonwoven fabric is usually 0.5 to 5 × 10 ⁻⁹ C (coulomb) /.
It is desirable to be about cm ² .

The electret according to the present invention can be used as it is, or can be used by laminating a reinforcing layer or the like. Further, it can be used after being subjected to a process such as pleating. When such a process is performed, it is preferable that a reinforcing layer or the like is laminated. The reinforcing layer can be formed of a woven fabric, a nonwoven fabric, a net or paper made of a synthetic resin such as polyethylene terephthalate, nylon, or polypropylene.

The electret of the present invention has a high surface charge density and is excellent in maintaining the surface charge density at high temperatures, so that it is used as a material for audio equipment such as microphones, pickups, and speakers; It is suitable for medical materials, especially materials for medical instruments that come into contact with blood. In particular, it is suitable as a material for electret filters used in air filters and the like.

In particular, when the electret according to the present invention is formed of a non-woven fabric, it has excellent surface charge density retention under high temperature and high humidity, and when used as a filter, has a long collecting performance. For this reason, the electret in the form of the nonwoven fabric according to the present invention is suitably used particularly for air filters, for example, as air filters for air conditioners, air purifiers, vacuum cleaners, fan heaters and automobiles. Electrets in the form of non-woven fabrics are excellent in collecting performance, so they are not stuffy even when worn as a mask for a long time, and are used for industrial and household air masks that remove bacteria such as fine dust, bacteria and viruses. Can be suitably used.

[0085]

According to the present invention, it is possible to provide an electret which has a high surface charge density even at a normal temperature or a high temperature and is excellent in retention of the surface charge density. In addition, it is possible to provide an electret excellent in collecting performance of fine dust and the like, which is preferably used particularly for an air filter.

[0086]

EXAMPLES Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

[0087]

[Preparation Example 1] Preparation of cyclic hydrocarbon-based polymer (a) MFR: 3 g / 10 min (temperature: 200 ° C, load: 5 kg)
Is polystyrene (G590, manufactured by Nippon Polysty Co., Ltd.) 1
was dissolved in 50 liters of cyclohexane, and the stabilized nickel catalyst N163A (Nippon Chemical Industrial Co., Ltd., 40
% Nickel-supported silica-alumina support) and mixed. This was degassed, replaced with nitrogen gas, and further subjected to a hydrogenation reaction at 230 ° C. and a hydrogen pressure of 50 kg / cm ² for 10 hours.

After completion of the reaction, the catalyst was removed by filtration, and a polymer was precipitated with isopropanol. This polymer was separated by filtration, and dried under reduced pressure to obtain a cyclic hydrocarbon polymer (a) which was a hydrogenated product of polystyrene. The physical properties of the cyclic hydrocarbon polymer (a) obtained were such that Tg was 14
3 ° C, density 0.95g / cm ³ , hydrogenation rate is more than 99%,
The weight average molecular weight (Mw) in terms of polystyrene is 170,
000, and the number average molecular weight (Mn) was 87,000. The crystallinity determined by X-ray diffraction was 0%.

[0089]

Example 1 90% by weight of the cyclic hydrocarbon polymer (a) obtained in Preparation Example 1 and 10% by weight of polypropylene graft-modified with maleic anhydride (graft ratio with maleic anhydride: 3% by weight) Was supplied simultaneously to an extruder (L / D = 40, manufactured by Nippon Steel Works, Ltd.) having a diameter of 40 mmφ, and was heated and melted at 270 ° C. to obtain resin pellets.

The obtained resin pellets were supplied to an inflation film molding machine (30 mmφ extruder, 80 mmφ die manufactured by Toshiba Machine Co., Ltd.), and the molding temperature was 270.
The film was molded under the molding conditions of 54 ° C. and an extruder screw rotation speed of 54 rpm to produce a film having a folded diameter of 110 mm and a thickness of 30 μm.

From this film, 80 mm × 220 mm
A sample having the following dimensions was cut out. This sample was placed on the earth electrode of a charge application device consisting of a needle electrode connected to a DC high voltage power supply (Matsusada Precision Device Co., Ltd.) and a stainless steel plate earth electrode, at a temperature of 25 ° C., a voltage of -7 KV, and a charging time. The charge treatment was performed for 30 seconds under the condition of a distance between the electrodes of 10 mm. Next, both surfaces were short-circuited with an aluminum plate to remove unstable surface charges, and then left at room temperature (about 25 ° C.) for 1 hour to obtain an electret. The surface charge density of this electret was measured by a surface charge density measuring device (manufactured by RIKEN) to obtain an initial surface charge density.

Further, the obtained electret was allowed to stand in a thermo-hygrostat (LHL-111 manufactured by Tabai) maintained at a temperature of 60 ° C. and a relative humidity of 80% for 24 hours, and then cooled to room temperature. The surface charge density after standing for 24 hours was measured by a surface charge density measuring device. From the surface charge density after standing for 24 hours and the initial surface charge density, the retention rate of the surface charge was determined according to the following equation.

Retention rate = [(surface charge density after standing) / (initial surface charge density)] 100 (%) The obtained electret was kept at a constant temperature of 80 ° C. and a relative humidity of 90%. Machine (made by Tabai LHL-1)
The sample was allowed to stand in 11) for 24 hours, cooled to room temperature, and the surface charge density after standing for 24 hours was measured by a surface charge density measuring device. From the surface charge density after standing for 24 hours and the initial surface charge density, the retention rate of the surface charge was determined according to the above equation. Table 1 shows the results. From the results, it was found that the retention rate of the surface charge at a high temperature was high.

[0094]

Example 2 90% by weight of the cyclic hydrocarbon-based polymer (a) obtained in Preparation Example 1 and maleic anhydride-modified polyethylene (graft ratio with maleic anhydride:
Electret was produced in the same manner as in Example 1 using a resin composition consisting of 10 parts by weight of (2.22% by weight).
The retention rate and the surface charge of the obtained electret were measured in the same manner as in Example 1. Table 1 shows the results. From the results, it was found that the retention rate of the surface charge was high even at high temperatures.

[0095]

Example 3 To 500 g of the cyclic hydrocarbon polymer (a) pellets obtained in Preparation Example 1, 50 g of maleic anhydride dissolved in 25 g of acetone and 2 g of an organic peroxide (Perhexin 25B manufactured by NOF Corporation) were added. After sufficient mixing, a graft modification reaction was performed while melting at a cylinder temperature of 280 ° C. using a twin-screw extruder (TEX manufactured by Nippon Steel Works), pelletized with a pelletizer, and a cyclic hydrocarbon-based polymer (a ) Was obtained. Of the resulting denatured product,
The graft ratio with maleic anhydride was 0.93% by weight.

95 parts by weight of the cyclic hydrocarbon polymer (a) obtained in Preparation Example 1 and the cyclic hydrocarbon polymer (a) graft-modified with maleic anhydride obtained as described above
(Graft rate with maleic anhydride: 0.93% by weight)
An electret was manufactured in the same manner as in Example 1 using a resin composition consisting of 5% by weight.

The retention rate and the surface charge of the obtained electret were measured in the same manner as in Example 1. Table 1 shows the results
Shown in From the results, it was found that the retention rate of the surface charge at a high temperature was high.

[0098]

Examples 4 and 5 The cyclic hydrocarbon polymer (a) obtained in Preparation Example 1 and the cyclic hydrocarbon polymer (a) graft-modified with maleic anhydride used in Example 3 (maleic anhydride (E.g., graft ratio of 0.93% by weight) in the weight ratio shown in Table 1 to produce an electret in the same manner as in Example 1. The retention rate and the surface charge of the obtained electret were measured in the same manner as in Example 1. Table 1 shows the results. From the results, it was found that the retention rate of the surface charge at a high temperature was high.

[0099]

Comparative Example 1 An electret was produced in the same manner as in Example 1 except that only the cyclic hydrocarbon polymer (a) obtained in Preparation Example 1 was used. The retention rate and the surface charge of the obtained electret were measured in the same manner as in Example 1. Table 1 shows the results. From the results, it was found that the initial surface charge density was low and the retention rate of the surface charge at high temperature was low.

[0100]

Comparative Example 2 Polypropylene (MFR: 0.5 g / 10
Min) 90% by weight and a polypropylene graft-modified with maleic anhydride (graft rate with maleic anhydride:
An electret was produced in the same manner as in Example 1 using a resin composition consisting of 3% by weight) and 10% by weight. The retention rate and the surface charge of the obtained electret were measured in the same manner as in Example 1. Table 1 shows the results. From the results,
It was found that the retention of surface charge at high temperatures was low.

[0101]

Comparative Example 3 Polypropylene (MFR: 0.5 g / 10
An electret was manufactured in the same manner as in Example 1 except that only the above component was used. The retention rate and the surface charge of the obtained electret were measured in the same manner as in Example 1. Table 1 shows the results. From the results, it was found that the retention rate of the surface charge at a high temperature was extremely low.

[0102]

[Table 1]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 23/02 C08L 23/02 4L035 25/02 25/02 4L047 45/00 45/00 51/00 51 / 00 D01F 6/20 D01F 6/20 D04H 1/42 D04H 1/42 K // B01D 39/14 B01D 39/14 E (C08L 23/02 (C08L 23/02 51:00) 51:00) (C08L 25 / 02 (C08L 25/02 51:00) 51:00) (C08L 45/00 (C08L 45/00 51:00) 51:00) F term (reference) 4D019 AA01 BA13 BB03 BB08 BC01 BD01 DA02 DA03 4D054 AA12 BA01 BC16 4F071 AA20 AA21 AA21X AA31X AA36X AA77 AA78 AF38 AG13 AH12 BA01 BB06 BC01 4J002 BB16W BC01W BK00W BN03X BN05W BN05X BN14W BN14X BN20W GD05 4J026 AA11 AA13 BB14 ABA11 AA13 BA13 AB14A3A3A3A3A3 C16

Claims (9)

[Claims] 1. A polymer compound comprising at least one cyclic hydrocarbon polymer (A) selected from the group consisting of the following (I), (II), (III), (IV) and (V): An electret comprising a resin composition containing a modified polymer compound (B) obtained by graft copolymerizing a modified monomer; (I) a vinyl-based monocyclic alicyclic hydrocarbon compound (co); A polymer or a copolymer of a vinyl-based monocyclic alicyclic hydrocarbon compound and a monomer copolymerizable therewith, or a hydrogenated product thereof; (II) a vinyl-based aromatic hydrocarbon compound A hydrogenated product of a (co) polymer or a hydrogenated product of a copolymer of a vinyl aromatic hydrocarbon compound and a monomer copolymerizable therewith, wherein at least one of the aromatic hydrocarbon rings 30% hydrogenated polymer; (III) monocyclic monoolefin (IV) a (co) polymer of a monocyclic cyclic conjugated diene compound and a copolymer of a monocyclic cyclic monoolefin compound and a monomer copolymerizable therewith; Unionized hydrogenated product or hydrogenated product of a copolymer of a monocyclic conjugated diene-based compound and a monomer copolymerizable therewith; (V) the above (I), (II), (III) A modified product obtained by graft-modifying at least one type of cyclic hydrocarbon-based polymer selected from the group consisting of (IV) and (IV) with an α, β-unsaturated carboxylic acid, anhydride or derivative thereof. 2. The electret according to claim 1, wherein in the modified polymer compound (B), the modified monomer is at least one selected from unsaturated carboxylic acids and derivatives thereof. 3. The electret according to claim 1, wherein the modified polymer compound (B) has a graft amount of the modified monomer of 0.05 to 15% by weight. 4. The modified polymer compound (B) based on 100 parts by weight of the cyclic hydrocarbon-based polymer (A).
The electret according to any one of claims 1 to 3, comprising 0.5 to 40 parts by weight. 5. The modified polymer compound (B) based on 100 parts by weight of the cyclic hydrocarbon polymer (A).
4. The composition according to claim 1, wherein the composition contains 2 to 15 parts by weight.
An electret according to any one of the above items. 6. The modified polymer compound (B) is a modified α-olefin (co) polymer or a cyclic hydrocarbon polymer (A).
The electret according to any one of claims 1 to 5, wherein the electret is a modified product of the above. 7. The electret according to claim 1, wherein the electret is in the form of a film. 8. The electret according to claim 1, wherein the electret comprises a nonwoven fabric formed from a single fiber of the resin composition. 9. An electret having an average fiber diameter of a single fiber of 0.5 to 100 μm and a basis weight of 5 to 100 g / m ² ,
The non-woven fabric having a bulk density of 0.05 to 0.40 g / cm ³ and an average surface charge density of 0.1 × 10 ⁻⁹ coulomb / cm ² or more, according to claim 8, characterized in that: Electret.