JP2009292913A - Electrically conductive film and method for producing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film having excellent electric conductivity. <P>SOLUTION: In the electrically conductive film, a polymer segment having a quaternary ammonium salt group is chemically connected to the surface of the film. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a conductive film obtained by grafting a vinyl polymer having a quaternary ammonium base onto the film surface.

Conventional methods for imparting conductivity to polymers such as olefin polymers, vinyl chloride polymers, styrene polymers, urethane polymers, polyester polymers, polyamide polymers, and fluorine polymers. , A method of blending an electrolyte salt or a surfactant into a polyether ester amide (for example, see Patent Document 1); a method of blending a conductive substance such as carbon or metal fiber or powder into a polyether ester amide (for example, A method of introducing a conductive segment into a heat-degraded polyolefin (see, for example, Patent Documents 3 to 4) is known. However, the above-described method has a problem in that the blended electrolyte salt and the surfactant bleed out to the surface of the molded product over time and the physical properties are remarkably impaired.
Japanese Patent Laid-Open No. 7-10989 JP-A-7-216224 JP-A-3-290464 JP 2001-278985 A

  An object of the present invention is to provide a film having excellent conductivity.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have a quaternary ammonium base based on a new concept completely different from the conventional method of introducing a conductive polymer segment to the surface of a film. The inventors have found that a film obtained by grafting a vinyl polymer on the surface exhibits excellent conductivity without impairing mechanical properties, and completed the present invention.

That is, the present invention includes the following matters.
[1] A conductive film in which a polymer segment having a quaternary ammonium base is chemically bonded to the surface of the film.
[2] The conductive film as described in [1], wherein the quaternary ammonium base is a group represented by the following general formula (1) or (2).

However, in formula (1) and formula (2), R ¹ and R ² may be the same or different, and are each independently a hydrogen atom or a linear or branched fat having 1 to 22 carbon atoms. R ³ represents a linear or branched aliphatic hydrocarbon group having 1 to 22 carbon atoms or a hydroxyl alkyl group having 2 to 10 carbon atoms, and X ⁻ represents a halide ion or a halogenated alkyl ion. Represents an alkyl carboxylate ion, a nitroxide ion, an alkyl sulfate ion, a sulfonate ion, a phosphate ion or an alkyl phosphate ion, and Y ⁻ represents a carboxylate ion group, a nitroxide ion group, an alkyl sulfate ion group, a sulfonate ion group, a phosphate. An ionic group or an alkyl phosphate ionic group is represented.

[3] The conductive film as described in [1] or [2], wherein the film is a polyolefin film.
[4] A method for producing a conductive film, wherein a polymer segment is introduced onto the surface of a film by polymerizing a vinyl monomer having a quaternary ammonium base by an atom transfer radical polymerization method.
[5] The polymer segment is introduced into the film surface by copolymerizing a vinyl monomer having a quaternary ammonium base and a vinyl monomer not having a quaternary ammonium base. The manufacturing method of an electroconductive film.

  Since the film of the present invention exhibits excellent conductivity, it is extremely valuable industrially.

Hereinafter, the present invention will be described in detail.
The conductive film of the present invention is characterized in that a polymer segment having a quaternary ammonium base is chemically bonded to the surface of the film.

  The quaternary ammonium base according to the present invention is preferably a group of the following general formula (1) or general formula (2).

However, in formula (1) and formula (2), R ¹ and R ² may be the same or different, and are each independently a hydrogen atom or a linear or branched fat having 1 to 22 carbon atoms. R ³ represents a linear or branched aliphatic hydrocarbon group having 1 to 22 carbon atoms or a hydroxyl alkyl group having 2 to 10 carbon atoms, and X ⁻ represents a halide ion or a halogenated alkyl ion. Represents an alkyl carboxylate ion, a nitroxide ion, an alkyl sulfate ion, a sulfonate ion, a phosphate ion or an alkyl phosphate ion, and Y ⁻ represents a carboxylate ion group, a nitroxide ion group, an alkyl sulfate ion group, a sulfonate ion group, a phosphate. An ionic group or an alkyl phosphate ionic group is represented.

As the linear aliphatic hydrocarbon group, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, octyl group, nonyl group, decyl group, dodecyl group, tetradecyl group,
Examples include a hexadecyl group, an octadecyl group, and an oleyl group. Examples of the branched hydrocarbon group include an isopropyl group and a 2-ethylhexyl group. Among these, Preferably they are a C1-C14 hydrocarbon group, More preferably, it is a C1-C8 hydrocarbon group, More preferably, they are a methyl group and an ethyl group, Most preferably, it is a methyl group.

From the viewpoint of long-term antibacterial expression, it is preferable that one or both of R ¹ and R ² is not other than a hydrogen atom.
Examples of the hydroxylalkyl group include a 2-hydroxyethyl group, a 3-hydroxypropyl group, a 2-hydroxyisopropyl group, and a 6-hydroxyethyl group.

X ⁻ represents a halide ion, an alkyl halide ion, an alkyl carboxylate ion, a nitroxide ion, an alkyl sulfate ion, a sulfonate ion, a phosphate ion, and an alkyl phosphate ion, and Y ⁻ represents a carboxylate ion group or a nitroxide ion. Groups, alkyl sulfate ion groups, sulfonate ion groups, phosphate ion groups and alkyl phosphate ion groups.

X ⁻ and Y ⁻ are required to form a stable salt with the ammonium cation in the general formula (1) or the general formula (2), and when X ⁻ and Y ⁻ have an alkyl group, the alkyl cation The group may be covalently bonded to R ¹ , R ² or R ³ .

  The polymer segment according to the present invention has the quaternary ammonium base introduced therein. Here, the “polymer segment” refers to an addition polymer of a vinyl monomer having a carbon-carbon double bond, and a quaternary ammonium base is introduced into a side chain of the polymer segment. The quaternary ammonium base may be introduced into all of the side chains of the vinyl monomer addition polymer, or may be introduced into a part of the side chains. That is, a vinyl monomer having a quaternary ammonium base may be polymerized alone, or a vinyl monomer having a quaternary ammonium base and a vinyl monomer having no quaternary ammonium base may be copolymerized. In order to sufficiently develop the electrical conductivity and hydrophilicity, the polymer segment has a quaternary ammonium base in an amount of usually 10 mol% to 100 mol%, preferably 50 mol% to 100 mol% in the side chain. It is desirable that

  The vinyl monomer having a quaternary ammonium base is not particularly limited as long as it is a vinyl monomer having the structure of the general formula (1) or the general formula (2), but from the viewpoint of ease of use in production, For example, quaternary ammonium salt derivatives such as acrylic acid ester, methacrylic acid ester, acrylamide, methacrylamide and styryl are used. Specifically, methacryloylaminopropyltrimethylammonium chloride, methacryloyloxyethyltrimethylammonium chloride (methacryloylcholine chloride), methacryloyloxyethyltrimethylammonium methylsulfonate, 2-hydroxy-3-methacryloxypropyltrimethylammonium chloride, 2- Hydroxy-3-methacryloxypropyltrimethylammonium chloride, 1-methyl-2-vinylpyridinium triflate, 1-methyl-2-vinylpyridinium chloride, 1-methyl-4-vinylpyridinium chloride, 1-methyl-4-vinylpyridinium Bromide, alkyl phosphate of 2- (dimethylamino) ethyl methacrylate, 2- (dimethylamino) ethyl methacrylate Carboxylate, 2-alkyl amine salt of (dimethylamino) ethyl methacrylate acid salts and acidphosphoxyethyl methacrylate are exemplified.

The molecular weight of the polymer segment by gel permeation chromatography is usually 200 to 1,000,000 g / mol, preferably 2,000 to 1,000,000 g / m.
ol. It is preferable that the molecular weight is in the above-mentioned range since the conductivity can be expressed well without impairing the opportunity physical properties of the molded body.

  Moreover, the polymer segment may be partially or wholly crosslinked. In this case, the molecular weight is not particularly limited, but if the molecular weight is extremely small, the polymer segment may be buried inside the film when used over a long period of time, which may cause poor conductivity.

  The film thickness derived from the polymer segment on the surface of the film is 1 nm or more, preferably 10 nm or more as an average film thickness when moisture, an organic solvent, or the like is removed. The film thickness is directly evaluated by measuring a sample obtained by cutting and staining a cross section using a transmission electron microscope (TEM).

  In the polymer segment, at least one end of the polymer segment is chemically bonded to the surface of the base film. That is, the end of the polymer segment is covalently bonded to the surface of the base film. At this time, the polymer segment may be directly covalently bonded to any group present on the surface of the base film, or via a short spacer that covers the surface of the base film to such an extent that the conductivity is not impaired. May be combined. When the surface of the base film is covered with a spacer, the weight of the spacer is preferably less than 5% of the weight of the polymer segment. The structure of the spacer is not particularly limited, but is preferably a hydrocarbon group having 1 to 20 carbon atoms.

As a base film used for manufacture of the conductive film of the present invention, a film made of a general-purpose thermoplastic resin or thermosetting resin can be used. A commercially available film may be used, or the film may be produced by a conventionally known method. Examples of commercially available products include F113G (manufactured by Prime Polymer Co., Ltd., polypropylene biaxially stretched film), Opyran (Mitsui Chemical Co., Ltd. methylpentene copolymer) and Apel APL6011T (Mitsui Chemicals Co., Ltd. cyclic olefin). Copolymer). The resin used as the raw material for the base film is not particularly limited. For example, polyolefin resins such as polyethylene and polypropylene, vinyl chloride resins, styrene resins, urethane resins, silicon resins, polyesters, and polyamide resins may be used. Can be mentioned. Of these, polyolefin resins are preferred. Examples of the polyolefin resin include homopolymers or copolymers such as ethylene, propylene, α-olefins having 4 or more carbon atoms, cyclic olefins, conjugated dienes and nonconjugated dienes. These resins may be used alone or in combination of two or more. By forming these resins into an unstretched film, a uniaxially stretched film, a biaxially stretched film, or the like, the base film of the conductive film of the present invention can be produced.

The base film may be a single layer film or a multilayer film. In the case of a multilayer film, at least the surface layer may be given conductivity.
In the raw material resin used for the said base film, you may add another component as needed in the range which does not impair the effect of this invention. Other components include conventionally known heat stabilizers, weather stabilizers, various stabilizers, antioxidants, dispersants, slip agents, antiblocking agents, antifogging agents, antibacterial agents, lubricants, dyes, pigments, natural oils. Synthetic oils, waxes and fillers.

The conductive film of the present invention has a smaller surface resistivity value than a base film that has not been subjected to conductivity imparting treatment. Although the measuring method of surface specific resistivity is not specifically limited, For example, it can measure according to Japanese Industrial Standard (JIS) K6911. When the value of the surface resistivity of the film is small, it is advantageous for developing conductivity. The range of the surface resistivity of the conductive film of the present invention is not particularly limited as long as it is smaller than the value of the surface resistivity of the substrate film, but is usually 10 ¹⁵ Ω or less, preferably 10 ^12. Ω or less, more preferably 10 ¹⁰ Ω or less, and even more preferably 10 ⁸ Ω or less. The lower limit of the conductive film of the present invention is not particularly limited as long as desired physical properties are not impaired.

Next, the manufacturing method of the electroconductive film of this invention is demonstrated.
As a manufacturing method of the electroconductive film of this invention, the method of carrying out the graft polymerization of the vinyl monomer which has a quaternary ammonium base on the surface of the film used as a base material is mentioned. In this case, in addition to a method in which a vinyl monomer having a quaternary ammonium base is directly graft-polymerized (or copolymerized) on the surface of the base film, after a vinyl monomer having no quaternary ammonium base is graft-polymerized, There is a method of introducing a quaternary ammonium salt by functional group conversion or the like. The selection of the production method is made in consideration of the rate of graft polymerization and the ease of formation of the carboxylate.

  As a method of graft polymerization, a method of causing a radical generator such as an organic peroxide to act or a method of grafting using X-ray irradiation, gamma ray irradiation, electron beam irradiation, microwave or ultraviolet irradiation, etc. are known. The polymer segment according to the present invention can be introduced by these methods. However, in these methods, (1) the decomposition reaction of the surface of the base film proceeds, or an ungrafted vinyl monomer homopolymer is formed (2) heavy on the surface of the base film. There are cases where the coalesced segments are grafted with high density, and it is difficult to achieve a high molecular weight (3) equipment costs are high.

  As a production method for solving such problems, application of controlled radical polymerization can be mentioned. Controlled radical polymerization is a radical polymerization technique that suppresses side reactions such as termination reactions and chain transfer reactions by controlling the radical concentration in the polymerization system to a low level, unlike conventional free radical polymerization techniques using peroxide addition systems. is there. According to this method, since the polymerization often proceeds like a living polymerization, a segment having a high molecular weight and a narrow molecular weight distribution can be obtained.

The controlled radical polymerization method applied to the present invention is a method disclosed in Trend Polym. Sci., (1996), 4, 456, which is combined with a group having a nitroxide to generate a radical by thermal cleavage. And a monomer polymerization method (NMRP: Nitroxide-Mediated Radial Polymerization) and an atom transfer radical polymerization (ATRP) method. Among these, the atom transfer radical polymerization method includes Science, (1996), 272, 866, Chem. Rev., 101, 2921 (2001), WO96 / 30421, WO97 / 18247, WO98 / 01480, WO98 / No. 40415, WO00 / 156795, or Sawamoto et al., Chem. Rev., 101, 3689 (2001), JP-A-8-41117, JP-A-9-208616, JP-A-2000-264914, A method disclosed in JP-A-2001-316410, JP-A-2002-80523, and JP-A-2004-307872, wherein an organic halide or a sulfonyl halide compound is used as an initiator, and a transition metal is a central metal A radical polymerization of a radically polymerizable monomer using a metal complex as a catalyst, or reversible addition-fragmentation chain transfer polymerization (RAFT)
Transfer).

  Among the above-mentioned controlled radical polymerization methods, the atom transfer radical polymerization method introduces the polymer segment according to the present invention because it is easy to introduce radical polymerization initiating groups and there are abundant monomer types that can be selected. This is an effective polymerization method.

The production method using the atom transfer radical polymerization method will be described more specifically.
As disclosed in Science, (1996), 272,866, etc., in order to initiate atom transfer radical polymerization, it is necessary that the surface of the substrate film has a site to which a halogen atom is bonded, The bond dissociation energy of the halogen atom is preferably small. For example, a halogen atom bonded to a carbon atom adjacent to a carbon-carbon unsaturated bond such as a halogen atom, vinyl group, vinylidene group, and phenyl group bonded to a tertiary carbon atom, or a conjugated group such as a carbonyl group, a cyano group, and a sulfonyl group. It is preferable that a halogen atom bonded to an atomic group directly or to an atom adjacent to these conjugated groups is present.

Examples of a method for introducing a halogen atom having such an atom transfer radical polymerization initiating ability onto the surface of the substrate film include a functional group conversion method and a direct halogenation method.
The functional group conversion method is preferably applied when functional groups such as a hydroxyl group, a carboxyl group, an acid anhydride group, a vinyl group, and a silyl group are present on the surface of the base film. A method for converting these functional groups into the structure of an atom transfer radical polymerization initiator is disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-131620, and a hydroxyl group-containing polyolefin is modified with a low molecular weight compound such as 2-bromoisobutyric acid bromide. A method for obtaining a surface halogenated film having the ability to initiate atom transfer radical polymerization is disclosed.

The direct halogenation method is a method of obtaining a halogenated polyolefin having a carbon-halogen bond by allowing a halogenating agent to act directly on the surface of a base film. The type of halogenating agent to be used and the type of halogen atom to be introduced are not particularly limited, but considering the balance between the stability of the atom transfer radical polymerization initiation skeleton and the initiation efficiency, a brominated polyolefin having a bromine atom introduced can be used. The obtaining method is preferred. Examples of the halogenating agent used in the production of the halogenated polyolefin include bromine and N-bromosuccinimide (NBS). For bromination
For example, as disclosed in J. Am. Chem. Soc., 77, 4025 (1955) by GA Russel et al., Photobromination reaction in which bromine is reacted under light irradiation to bromine alkenes, Ang Schew by PR Schneiner et al. Chem. Int. Ed. Engl., 37, 1895 (1998) disclosed in the method of bromination by heating and refluxing cyclic alkyl in solution in the presence of 50% aqueous NaOH and carbon tetrabromide, or MC For example, disclosed in J. Chem. Soc., 2240 (1952) by Ford et al., A method in which N-bromosuccinimide is subjected to radical reaction using a radical initiator such as azobisisobutyronitrile to brominate an alkyl terminal, etc. Is mentioned.

The presence of halogen atoms introduced on the surface of the surface halogenated film obtained as described above is confirmed by a spectroscopic method such as X-ray photoelectron spectroscopy.
Atom transfer radical polymerization is performed by contacting with a vinyl monomer and a catalyst component in the presence of a surface halogenated film. At this time, a solvent may be used. The solvent that can be used is not particularly limited as long as it does not inhibit the polymerization reaction and can be a polymerization temperature that does not alter the surface halogenated film. For example, aromatic hydrocarbon solvents such as benzene, toluene and xylene; aliphatic hydrocarbon solvents such as pentane, hexane, heptane, octane, nonane and decane; alicyclics such as cyclohexane, methylcyclohexane and decahydronaphthalene Hydrocarbon solvents; chlorinated hydrocarbon solvents such as chlorobenzene, dichlorobenzene, trichlorobenzene, methylene chloride, chloroform, carbon tetrachloride and tetrachloroethylene; methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol and alcohol solvents such as tert-butanol; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and dimethyl phthalate; dimethyl ether, diethyl ether And ether solvents such as ether, di-n-amyl ether, tetrahydrofuran and dioxyanisole. Further, water may be used as a solvent. These solvents may be used alone or in combination of two or more. The polymerization temperature can be arbitrarily set as long as it is a temperature at which the surface halogenated film into which the atom transfer radical polymerization initiating group is introduced does not change and the temperature at which the radical polymerization reaction proceeds. The polymerization temperature is determined by the degree of polymerization of the desired polymer, the type and amount of the radical polymerization initiator and solvent used, and is usually -50
It is -150 degreeC, Preferably it is 0-80 degreeC, More preferably, it is 0-50 degreeC. The polymerization reaction may be performed under any conditions of reduced pressure, normal pressure or increased pressure. After completion of the reaction, the catalyst residue, unreacted monomer and solvent are removed using a conventionally known purification / drying method.

In addition, when a film is a roll sheet form etc., you may perform the process of said bromination and superposition | polymerization continuously.
The introduction of the polymer segment on the film surface is confirmed by a spectroscopic method such as ion chromatography, electron beam microanalyzer, or infrared spectroscopy.

The conductive film of the present invention can be used for various film applications without particular limitation. For example, in addition to general packaging applications such as packaging films, retort films, laminate films, shrink films and protective films, display device fields suitably used in the following fields: membrane switches, liquid crystal display devices (retardation films, polarizing films) And plastic liquid crystal cell), electroluminescence, electrochromic, electrophoretic display, plasma display panel, field emission display, and diffusion film for backlight;
Color filter recording field: electrostatic recording substrate, OHP, slide film, microfilm and X-ray film;
Optical and magnetic memory field: Thermo-plastic recording, ferroelectric memory, magnetic tape, ID card and bar code;
Antistatic field: Meter windows, television cathode-ray tubes, clean room windows, semiconductor packaging materials, VTR tapes and dust masking films for photomasks;
Electromagnetic shielding field: measuring instrument, medical device, radiation detector, IC component, CRT, liquid crystal display device, photoelectric conversion element field: solar cell window, optical amplifier and optical sensor;
Heat ray reflection field: windows (architecture and automobiles, etc.), incandescent bulbs, cooking oven windows, furnace viewing windows and permselective membranes;
Planar heating element field: defroster, aircraft, automobile, freezer, incubator, goggles and medical equipment;
Liquid crystal display device electronic parts and circuit materials field: capacitors, resistors and thin film composite circuits;
Mounting electrode field: Paper battery electrode;
Light transmission filter field: UV cut filter, UV transmission filter, UV transmission visible light absorption filter, color separation filter, color temperature conversion filter, neutral density filter, contrast filter, wavelength calibration filter, interference filter, infrared transmission filter, infrared cut filter , Heat absorption filters and heat reflection filters;
Gas selective permeable membrane field: oxygen / nitrogen separation membrane, carbon dioxide separation membrane and hydrogen separation membrane;
Electrical insulation field: Insulation adhesive tape, motor slot liner and transformer phase insulation polymer;
Sensor field: light sensor, infrared sensor, sound wave sensor and pressure sensor;
Surface protection field: Liquid crystal display, CRT, furniture and system kitchen;
Automotive exterior and other fields: heat transfer, printer ribbon, electric cable shield, and water leakage prevention film [Example]
EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples.

[Preparation Example 1] Bromination of OPP film Polypropylene biaxially stretched (OPP) film (F113G (manufactured by Prime Polymer Co., Ltd.))
Resin temperature: 230 ℃, chill roll temperature: 50 ℃ using a small sheet molding machine (TS-300-200) manufactured by M company
After taking a sheet having a thickness of 500 μm at a take-off speed of 1.0 m / min, using a Bruckner stretching machine (KARO IV), preheating temperature: 153 ° C., preheating time: 60 seconds, draw ratio: 5 The film was stretched (sequential biaxial stretching) at (MD) × 7 (TD) and stretching speed: 6 m / min to obtain a biaxially stretched film having a thickness of 40 μm. This biaxially stretched film was put into a glass container with an internal volume of 1000 mL purged with nitrogen, and 0.2 mL of bromine was sealed at the bottom of the container. About 5 minutes later, after bromine was completely vaporized, a 300 W incandescent bulb was irradiated with light vertically from a distance of 15 cm from the film. After 10 minutes, unreacted bromine vapor present in the system was replaced with nitrogen gas, and then the film was taken out.
As a result of surface analysis by X-ray photoelectron spectroscopy, it was confirmed that a brominated OPP film in which 12.8 atom% bromine atoms were grafted on the surface of the film was obtained.

[Preparation Example 2] Bromination of TPX film A methylpentene copolymer (TPX) film (Opylan: manufactured by Mitsui Chemicals, Inc.) was placed in a glass container with an internal volume of 1000 mL purged with nitrogen, and 0.2 mL of bromine was sealed in the container. . After about 5 minutes, the bromine was completely vaporized and then irradiated with light. After 10 minutes, unreacted bromine vapor present in the system was replaced with nitrogen gas, and the film was taken out.
As a result of surface analysis by X-ray photoelectron spectroscopy, it was confirmed that a brominated TPX film in which 10.5 atom% of bromine atoms were grafted on the surface of the film was obtained.

[Preparation Example 3] Bromination of COC film A cyclic olefin copolymer (COC) (Appel APL6011T: Mitsui Chemicals, Inc.) press film (film thickness: 120 μm) is placed in a glass container with an internal volume of 1000 mL purged with nitrogen. Then, 0.1 mL of bromine was sealed in a container. After about 5 minutes, the bromine was completely vaporized and then irradiated with light. After 10 minutes, unreacted bromine vapor present in the system was replaced with nitrogen gas, and the film was taken out.
As a result of surface analysis by X-ray photoelectron spectroscopy, it was confirmed that a brominated COC film in which 8.0 atom% bromine atoms were grafted on the film surface was obtained.

[Production Example 1]
The brominated OPP film obtained in Production Example 1 was completely immersed in a glass container containing methanol and methacryloylcholine chloride (80% aqueous solution: manufactured by Tokyo Chemical Industry Co., Ltd.) in a volume ratio of 33/67. It was. There, a 1: 2 (molar ratio) ethanol preparation of copper (I) bromide and N, N, N ', N ", N" -pentamethyldiethylenetriamine (concentration of copper (I) bromide 0.8M) Was added so that the copper (I) bromide concentration was 2.5 mM, and kept at 60 ° C. for 1 hour. The film was taken out, washed twice with methanol and dried under reduced pressure at 80 ° C. for 10 hours to obtain a polypropylene film (F-1) having a methacryloylcholine chloride polymer introduced on the surface of the film.

Table 1 shows the structure of the polypropylene film (F-1).
When TEM observation of the cross section near the surface of the obtained polypropylene film (F-1),
A dyed region having a thickness of about 60 to 80 nm, which was estimated to be a layer of methacryloylcholine chloride polymer, was observed on the surface of the film.

[Production Example 2]
In Production Example 1, a TPX film (F-2) was produced in the same manner as in Production Example 1 except that the brominated TPX film obtained in Preparation Example 2 was used as a brominated film, and TEM observation was performed.
Table 1 shows the structure of the TPX film (F-2).

[Production Example 3]
In Production Example 1, a COC film (F-3) was produced in the same manner as in Production Example 1 except that the brominated COC film obtained in Preparation Example 3 was used as the brominated film, and TEM observation was performed. .

  Table 1 shows the structure of the COC film (F-3).

[Evaluation of film conductivity]
Each of the films (F-1 to F-3) obtained in Production Examples 1 to 3 and the polypropylene biaxially stretched film (base film) used in Preparation Example 1 as a comparative sample each have a size of 5 cm × 5 cm. And cut into samples. The conductivity test of the sample was performed according to JIS K 6911.
Test conditions: Temperature 23 ± 2 ℃, humidity 50 ± 5%, film thickness about 40μm
In addition to the above test, the film (F-1) obtained in Production Example 1 was immersed in water at room temperature for 8 hours, washed with water, and then dried for 20 days at room temperature under reduced pressure. went. The results are shown in Table 1.

From Table 2, it is clear that the film (F-1 to F-3) of the present invention in which a vinyl polymer having a quaternary ammonium base is grafted on the surface of the film has superior conductivity compared to the comparative sample. It is.

  The conductive film of the present invention is used as a packaging film, a retort film, a laminate film, a shrink film and a protective film, as well as an antistatic film, an electromagnetic wave shielding film, a transparent electrode, a transparent surface heating element and a polymer solid electrolyte. It is suitably used for electronic equipment related members such as display materials, battery materials and circuit boards.

FIG. 1 is a diagram showing a cross-sectional TEM photograph of the film surface of a polypropylene film (F-1).

Claims (5)

  A conductive film in which a polymer segment having a quaternary ammonium base is chemically bonded to the surface of the film. The conductive film according to claim 1, wherein the quaternary ammonium base is a group represented by the following general formula (1) or (2).
(In Formula (1) and Formula (2), R ¹ and R ² may be the same or different, and each independently represents a hydrogen atom or a linear or branched aliphatic group having 1 to 22 carbon atoms. R ³ represents a hydrocarbon group, R ³ represents a linear or branched aliphatic hydrocarbon group having 1 to 22 carbon atoms or a hydroxyl alkyl group having 2 to 10 carbon atoms, X ⁻ represents a halide ion, an alkyl halide ion, Represents an alkyl carboxylate ion, a nitroxide ion, an alkyl sulfate ion, a sulfonate ion, a phosphate ion or an alkyl phosphate ion, and Y ⁻ represents a carboxylate ion group, a nitroxide ion group, an alkyl sulfate ion group, a sulfonate ion group, a phosphate ion. Represents a group or an alkyl phosphate ion group.)   The conductive film according to claim 1, wherein the film is a polyolefin film.   A method for producing a conductive film, wherein a polymer segment is introduced onto the surface of a film by polymerizing a vinyl monomer having a quaternary ammonium base by an atom transfer radical polymerization method.   The conductive segment according to claim 4, wherein a polymer segment is introduced into the film surface by copolymerizing a vinyl monomer having a quaternary ammonium base and a vinyl monomer not having a quaternary ammonium base. A method for producing a film.