JP2010090217A - Organic magnetic material, method of producing the same, and magnetic ink composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a novel organic magnetic material having high radical concentration and saturated magnetization ratio with a good reproducibility, a method of producing the material, and a magnetic ink composition containing the organic magnetic material. <P>SOLUTION: The organic magnetic material includes a π electron conjugated polymer and a dicyanamide anion. In the method of producing the organic magnetic material, the π electron conjugated polymer is doped using an ionic liquid having a dicyanamide anion as an anion species. The magnetic ink composition contains the organic magnetic material. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a novel organic magnetic material, a method for producing the same, and a magnetic ink composition containing the organic magnetic material. More specifically, the present invention includes a π electron conjugated polymer and a dicyanamid anion, and can obtain a g value (radical concentration) of 10 ¹⁶ / g level and a saturation magnetic susceptibility of 7.0 emu / g or more. The present invention relates to an organic magnetic material, an effective production method thereof, and a magnetic ink composition containing the organic magnetic material.

  Magnetic materials are widely used as permanent magnetic materials, high magnetic permeability materials, magnetostrictive materials, etc., in many fields such as acoustic materials, electrical machinery, electronic fields, automobile fields, medical fields, and magnetic recording fields. In particular, organic magnetic materials have advantages such as low density, good dispersibility in binder resins, and many white or light-colored materials compared to inorganic magnetic materials. Has been made.

For example, a black powder polymer obtained by heating or ultraviolet irradiation of 1,4-bis (2,2 ′, 6,6′-tetramethyl-1-oxyl) butadiyne (see Non-Patent Document 1), 1, A black insoluble polymer obtained by polymerizing 3,5-triaminobenzene with iodine (see Non-Patent Document 2) has been reported as an organic ferromagnetic material. However, these are all difficult to synthesize, have problems with reproducibility, only a few percent of ferromagnetism appears, the temperature of magnetic development is extremely low, and they are unstable in the air. For example, it was not a practical magnetic material.
Furthermore, an organic magnetic material (see Patent Document 1) composed of a condensed polycyclic aromatic resin (COPNA) made from a condensed polycyclic aromatic compound using p-xylylene glycol as a linking agent, or in place of the p-xylylene glycol By using benzaldehyde or benzenedialdehyde, an organic magnetic material made of a thermosetting resin having higher heat resistance (see Patent Document 2) is disclosed. These resins are said to exhibit ferromagnetism at room temperature, but have a problem that the polymer structure is not clear and reproducibility is very poor.

Further, an organic magnetic material obtained by doping a tetraazaporphine derivative having a magnetic metal and / or a compound of a magnetic metal as a central metal with an alkali metal is disclosed (see Patent Document 3).
This organic magnetic material, for example, contains at least one magnetic metal selected from Fe, Co, Ni, Mn, and the like as a central magnetic metal to exhibit magnetism, and is further doped with an alkali metal to magnetically The characteristics are improved, and the manifestation of magnetism is due to the magnetic metal as the central metal.

On the other hand, research on ionic liquids has been actively conducted in recent years. This ionic liquid is generally formed from a cation and an anion and is a liquid at room temperature (for example, 10 to 30 ° C.) (also referred to as a room temperature molten salt).
Such an ionic liquid is generally composed of a combination of a cation such as imidazolinium or pyrrolidinium and a suitable anion (Br ⁻ , Cl ⁻ , SO ₄ ⁻ , BF ₄ ⁻ , PF ₆ ^−, etc.) Because of its ionic conductivity and excellent thermal stability, research is being conducted on application to electrolytes or electrolytes such as batteries and capacitors. (Refer nonpatent literature 3).

In addition, π-electron conjugated polymers such as polythiophene, polyaniline, polypyrrole, polyphenylene vinylene, or derivatives thereof exhibit conductivity when doped with various anions or various cations. It is known that it can be increased, and research is actively conducted on application to electrolytes such as batteries and capacitors.
As an example in which the ionic liquid and the π-electron conjugated polymer are used in combination, a mixture containing an ionic liquid, a conductive polymer in the form of a cation, and a polyanion associated with the conductive polymer is disclosed ( Patent Document 4), and as a preferable ionic liquid, a cation selected from cations selected from imidazolium, pyridinium, pyrrolidinium, phosphonium, ammonium, guanidinium, and isouronium monosubstituted, disubstituted, or trisubstituted Anion with anion selected from halide, sulfate, sulfonate, amide, imide, borate, phosphate, antimonate, cobalt tetracarbonyl, trifluoroacetate, decanoate Is shown. Further, as preferred conductive polymers, unsubstituted or substituted pyrrole-containing polymers, thiophene-containing polymers, and aniline-containing polymers are shown.
However, this technique is a technique that remarkably increases the conductivity of the composition by adding an ionic liquid to the composition containing the π-electron conjugated polymer, and no mention is made of any magnetic properties. Absent.

Incidentally, one of the uses of magnetic materials is magnetic ink. The magnetic ink is generally composed of a vehicle in which a magnetic material, a pigment, a resin, a dispersion solvent, and the like are combined, an additive, and the like, and is used for oil-based ink, water-based ink, hot-melt ink, and the like. For example, an ink in which a magnetic substance is colloidally dispersed in an organic solvent such as kerosene or glycerin or water, and an ink in which a magnetic substance is dispersed in wax are known.
Usually, magnetic inks are made of metal oxides such as ferrite, chromium oxide, Mn-Bi alloy, Mn-Al alloy, Fe-Ni alloy, Sn-Fe alloy, etc. The compatibility of the magnetic material is poor, the magnetic material tends to aggregate, and the dispersibility is poor. Further, after the image formation, after the magnetic ink is dried, cracks are likely to occur. Furthermore, since the magnetic ink has a dark inorganic magnetic material (for example, black, black-brown, brown, etc.), it is difficult to color, and the colors of pigments and dyes are not reflected as they are.

JP-A-62-521 JP 62-282080 A JP-A-10-208914 Special table 2008-535964 Nature 326, 370 (1987) Synth. Metal, 19, 709 (1987) Supervised by Hiroyuki Ohno, “Ionic liquid”, CM Publishing (2003)

  The present invention has been made under such circumstances, and includes a novel organic magnetic material having good reproducibility and high radical concentration and saturation magnetic susceptibility, an effective manufacturing method thereof, and the organic magnetic material. An object of the present invention is to provide a magnetic ink composition that has good dispersibility, good colorability, and does not impair the color of the pigment.

As a result of intensive studies to achieve the above object, the present inventors have obtained the following knowledge.
Organic magnetic material capable of obtaining g value (radical concentration) of 10 ¹⁶ / g level and saturation magnetic susceptibility of 7.0 emu / g or more by doping dian electron conjugated polymer with dicyanamid anion Can be obtained with good reproducibility, and this organic magnetic material can be easily obtained by using an ionic liquid having a dicyanamid anion and doping a π-electron conjugated polymer with the dicyanamid anion. I found out that
In addition, the organic magnetic material does not contain an inorganic material, has high transparency, and is colorless or light-colored. Therefore, the magnetic ink composition containing it has good solubility or dispersibility, It has been found that it is excellent in colorability with dyes and the like.
The present invention has been completed based on such findings.

That is, the present invention
[1] An organic magnetic material comprising a π-electron conjugated polymer and a dicyanamid anion,
[2] A dicyanamid anion is represented by the following general formula (I)
(Z ^{a +} ) _{m ′} ([(CN) ₂ N] ⁻ ) _n (I)
(Wherein, Z a ⁺ is a cation, a, m and n are each an integer of 1 to 3, when a plurality .Z a ⁺ is to satisfy the relation of a × m = n, ⁺ the plurality of Z ^a be the same or different May be.)
The organic magnetic material according to the above [1], which is contained in the form of an ionic liquid represented by
[3] ^{Za +} cation in the ionic liquid represented by the general formula (I) is represented by the following formulas (Ia), (Ib), (Ic) and (Id):

[R ^{1 in} Formula (Ia) represents a hydrocarbon group having 4 to 20 carbon atoms and may include a hetero atom, and R ² and R ³ are each independently a hydrogen atom or a carbon number of 1 to 16 carbon atoms. And may contain a hetero atom. However, when the nitrogen atom contains a double bond, there is no R ³ .
R ^{4 in} formula (Ib) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a hetero atom, and R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom or a carbon atom having 1 carbon atom. Represents ˜16 hydrocarbon groups and may contain heteroatoms.
R ⁸ in the formula (Ic) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a hetero atom, and R ⁹ , R ¹⁰ and R ¹¹ are each independently a hydrogen atom or a carbon atom having 1 carbon atom. Represents ˜16 hydrocarbon groups and may contain heteroatoms.
E in the formula (Id) represents a nitrogen, sulfur, or phosphorus atom, R ¹² , R ¹³ , R ^14, and R ¹⁵ each independently represents a hydrocarbon group having 1 to 20 carbon atoms; It may contain atoms. However, when E is a sulfur atom, there is no R ¹⁵ . ]
The organic magnetic material according to [1] or [2], which is at least one selected from cations represented by:
[4] The π-electron conjugated polymer is at least one selected from polythiophene, oligothiophene, polyaniline, polypyrrole, polyphenylene vinylene, and derivatives thereof, according to any one of the above [1] to [3]. Organic magnetic material.
[5] The organic magnetic material according to the above [4], wherein the π-electron conjugated polymer is polythiophene or a derivative thereof.
[6] The organic magnetic material according to any one of [1] to [5], including 100 to 600 parts by mass of the dicyanamid anion and the counter cation with respect to 100 parts by mass of the π-electron conjugated polymer. ,
[7] A method for producing an organic magnetic material, characterized in that a π-electron conjugated polymer is doped using an ionic liquid having a dicyanamid anion as an anion species, and [8] the above [1] to [1] [6] A magnetic ink composition comprising the organic magnetic material according to any one of
Is to provide.

According to the present invention, a reproducible organic magnetic material capable of obtaining a g value (radical concentration) of 10 ¹⁶ / g level and a saturation magnetic susceptibility of 7.0 emu / g or more and an effective manufacturing method thereof Can be provided.
In addition, according to the present invention, it is possible to provide a magnetic ink composition that contains the organic magnetic material, has good dispersibility, good colorability, and does not impair the color of the pigment.

  The organic magnetic material of the present invention is characterized in that it contains a π-electron conjugated polymer and a dicyanamid anion, and according to the method of producing an organic magnetic material of the present invention, a dicynic species is used. By doping the π-electron conjugated polymer using an ionic liquid having an anamide anion, the target organic magnetic material can be efficiently produced.

[Π-electron conjugated polymer]
As the π-electron conjugated polymer used in the present invention, those conventionally known as π-electron conjugated conductive polymers, such as polythiophene, oligothiophene, polyaniline, polypyrrole, polyphenylene vinylene, and derivatives thereof, It can be appropriately selected from polymers in which a saturated bond and an unsaturated bond (that is, π electrons) are continuous. The oligothiophene usually refers to a trimer to a 7-mer of thiophene, and a polymer having a higher degree of polymerization is referred to as polythiophene.
The weight average molecular weight of the polythiophene, polyaniline, polypyrrole, polyphenylene vinylene and derivatives thereof varies depending on the molecular weight of the monomer, but is usually 10,000 to 80,000, preferably 2.5 to 65,000. This weight average molecular weight can be measured as a polystyrene conversion value by a gel permeation chromatography (GPC) method.
Examples of the derivative include a substituent on the ring, such as an alkyl group, an alkoxy group, and a hydroxy group, for the purpose of imparting solubility in a solvent of the π-electron conjugated polymer, film-forming property, flexibility in the case of forming a film , Carboxy group, sulfonic acid group and the like, and copolymers such as (thiophene / phenylene) co-oligomer.
Of the π-electron conjugated polymers exemplified above, polythiophene and derivatives thereof are preferable from the viewpoint of transparency as an organic magnetic material, g value (radigal concentration), saturation magnetic susceptibility, and the like.

[Ionic liquid]
In the present invention, in order to obtain a high g value and saturated magnetic susceptibility by doping the above-mentioned π-electron conjugated polymer with a dicyanamid anion ([(CN) ₂ N] ⁻ ), the following general formula (I )
(Z ^{a +} ) _{m ′} ([(CN) ₂ N] ⁻ ) _n (I)
It is preferable to use an ionic liquid represented by
In the general formula (I), Z ^{a +} represents a cation, a, m, and n each represent an integer of 1 to 3, and satisfy the relationship of a × m = n. If Z a ⁺ there are multiple, ⁺ the plurality of Z ^a may be the same or different.
As the ^{Za +} cation in the general formula (I), cations represented by the following formulas (Ia), (Ib), (Ic) and (Id) (in the general formula (I), Preferably, at least one selected from a) and m is 1) is selected.

R ¹ in the formula (Ia) represents a hydrocarbon group having 4 to 20 carbon atoms, and may include a hetero atom, and R ² and R ³ each independently represent a hydrogen atom or a carbon atom having 1 to 16 carbon atoms. Represents a hydrocarbon group and may contain heteroatoms. However, when the nitrogen atom contains a double bond, there is no R ³ .
R ^{4 in} formula (Ib) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a hetero atom, and R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom or a carbon number. Represents 1 to 16 hydrocarbon groups and may contain heteroatoms.
R ⁸ in the formula (Ic) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a hetero atom, and R ⁹ , R ¹⁰ and R ¹¹ are each independently a hydrogen atom or a carbon number. Represents 1 to 16 hydrocarbon groups and may contain heteroatoms.
E in the formula (Id) represents a nitrogen, sulfur, or phosphorus atom, R ¹² , R ¹³ , R ^14, and R ¹⁵ each independently represent a hydrocarbon group having 1 to 20 carbon atoms, Hetero atoms may be included. However, when E is a sulfur atom, there is no R ¹⁵ .
Examples of the cation represented by the formula (Ia) include a pyridinium cation, a piperidinium cation, a pyrrolidinium cation, a cation having a pyrroline skeleton, and a cation having a pyrrole skeleton, and the formula (Ib) Examples of the cation represented by the formula include imidazolium cation, tetrahydropyrimidinium cation, dihydropyrimidinium cation and the like.
Examples of the cation represented by the formula (Ic) include a pyrazolium cation and a pyrazolinium cation. Examples of the cation represented by the formula (Id) include a tetraalkylammonium cation and a trialkyl. Examples include sulfonium cations, tetraalkylphosphonium cations, and those in which a part of the alkyl group is substituted with an alkenyl group, an alkoxy group, or an epoxy group.

Specific examples of the ionic liquid having a dianyanamide anion include those having a cation of the formula (Ia), such as 1-ethylpyridinium dicyanamide, 1-butylpyridinium dicyanamide, 1-butyl-4-methyl. Pyridinium dicyanamide, 1,1-dimethylpyrrolidinium dicyanamide, 1-ethyl-1-methylpyrrolidinium dicyanamide and the like; 1,3-dimethylimidazolium having a cation of formula (Ib) · Dicyanamid, 1,3-diethylimidazolium · Dicyanamid, 1-ethyl-3-methylimidazolium · Dicyanamid, 1,2-dimethyl-3-propylimidazolium · Dicyanamid, 1,3-dimethyl-1,4,5 , 6-Tetrahydropyrimidinium di Ianamide, 1,2,3-trimethyl-1,4,5,6-tetrahydropyrimidinium dicyanamide, 1,3-dimethyl-1,4-dihydropyrimidinium dicyanamide, and the like (Ic) Having cations of the above formula (Id), such as 1-methylpyrazolium dicyanamide, 3-methylpyrazolium dicyanamide, 1-ethyl-2-methylpyrazolinium dicyanamide, etc. Examples include tetramethylammonium dianciamide, tetraethylammonium dianciamide, triethylmethylammonium dianciamide, glycidyltrimethylammonium dianciamide, trimethylsulfonium dianciamide, triethylsulfonium dianciamide, tetramethyl Ruhosuhoniumu-Jisaianamido, tetraethyl phosphonium, Jisaianamido, such as triethyl methyl phosphonium-Jisaianamido, can be mentioned.
In the present invention, these ionic liquids may be used singly or in combination of two or more.

[Doping with ionic liquid]
In the present invention, the organic magnetic material of the present invention is obtained by doping the above-described π-electron conjugated polymer with the dicyanamid anion using the ionic liquid having the dicyanamid anion. It is done. As this doping method, a method suitable for using an ionic liquid as a dopant can be appropriately employed from methods conventionally used for doping a π-electron conjugated polymer.
For example, (1) an ionic liquid having a dicyanamid anion is added as a dopant to an organic solvent solution such as nitromethane containing a pi electron conjugated polymer, and the π electron conjugated polymer is reacted with the dicyanamid anion. (2) A method of doping by immersing a π-electron conjugated polymer film in an ionic liquid having a dicyanamid anion, and (3) an ion having a dicyanamid anion. A method of producing nanoparticles of a doped π-electron conjugated polymer by oxidative polymerization of thiophene, pyrrole, aniline, etc. in a solvent containing an ionic liquid (see JP 2008-74894 A), ( 4) Using an electrolyte solution containing an ionic liquid having a dianciamide anion, the π-electron conjugated polymer is electrochemically doped with dopin. Or the like can be used.

Thus, in the organic magnetic material of the present invention obtained by doping the π-electron conjugated polymer with the dicyanamid anion, from the viewpoint of the radical concentration and the saturation magnetic susceptibility, the π-electron conjugated polymer 100 It is preferable that 100 to 600 parts by mass of the dicyanamid anion and the counter cation are included and more preferably 150 to 500 parts by mass with respect to the part by mass.
When polythiophene is used as the π-electron conjugated polymer, the polythiophene generates a radical cation species (polaron) having the following structure by extracting electrons from the molecular chain by doping with the dicyanamid anion (the following formula reference).

（式中、Ｒは炭素数１〜２０のアルキル基、炭素数１〜２０のアルコキシ基、ヒドロキシ基、カルボキシ基又はスルホン酸基などを示す。）

(In the formula, R represents an alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, a hydroxy group, a carboxy group, or a sulfonic acid group.)

[Properties and uses of organic magnetic materials]
The organic magnetic material of the present invention uses, as a π-electron conjugated polymer, a polythiophene having a weight average molecular weight of about 30,000 as a π-electron conjugated polymer, and an ionic property having a dicyanamid anion as a dopant. In the case of using a liquid imidazolium dicyanamide compound, a high g value (radical concentration) of 2.0 × 10 ¹⁶ / g is obtained and a high saturation magnetic susceptibility of 12.2 emu / g is obtained.
The g value is a value obtained by measuring a low temperature (about 100 K) ESR spectrum (electron spin resonance spectrum), and the saturation magnetic susceptibility is a value measured at room temperature using a magnetic susceptibility measuring apparatus.
An organic magnetic material having a g value of about 10 ¹⁵ / g is generally known. However, in the present invention, it is at a level of 10 ¹⁶ / g, an order of magnitude higher than 10 ¹⁵ / g, and a saturation susceptibility. Is also expensive. Such characteristics are due to the fact that electrons are efficiently extracted from the molecular chain of polythiophene and more defective parts are generated by doping the π-electron conjugated polymer with the dicyanamid anion as an anion species. it is conceivable that.
Since the organic magnetic material of the present invention has such characteristics, when using the magnetic characteristics, the amount used is small, which is economically advantageous. In addition, the inorganic magnetic material has advantages such as a low density, good dispersibility in the binder resin, and many white or light-colored materials.
The organic magnetic material of the present invention is widely used in many fields such as an acoustic material, an electric field, an electronic field, an automobile field, a medical field, and a magnetic recording field as, for example, a permanent magnetic material, a high permeability material, a magnetostrictive material, and the like. be able to. It is also useful as a component of the magnetic ink composition shown below.

[Magnetic ink composition]
The magnetic ink composition of the present invention contains the organic magnetic material of the present invention described above.
Since the magnetic ink composition of the present invention uses an organic magnetic material as a magnetic material in this way, the entire ink composition can be composed of an organic material. As a result, the phase between the magnetic material and the vehicle can be reduced. It has good solubility, excellent dispersibility of the magnetic material, is easy to be colored, shows a vivid color, and an excellent image can be obtained with the magnetic ink composition of the present invention.
The magnetic ink composition of the present invention using the organic magnetic material is produced as an oil, water-based or hot-melt ink.

(Oil-based magnetic ink)
In the case of oil-based magnetic ink, it is obtained with a composition comprising a vehicle in which a magnetic material, a dye, oil, a resin, a dispersion solvent, and the like are combined, and an additive. In this case, specific examples of the dye include First Yellow G, Hansa Brilliant Yellow 5GX, Disazo Yellow AAA, Naphthol Red HFG, Lake Red C, Benzimidazolone Carmine HF3C, Dioxazine Violet, Phthalocyanine Blue, Indochron Blue, Phthalocyanine Green, benzimidazolone brown HFR, carbon black, aniline black, tartrazine lake, rhodamine 6G lake, methyl violet lake, basic 6G lake, brilliant green lake, nigrosine and the like.

  The vehicle is composed of oil, resin, dispersion solvent, etc. Specific examples of oil include linseed oil, linden oil, soybean oil, castor oil, dehydrated castor oil, lithovarnish, maleated oil, vinylated oil, urethanized oil Oil, machine oil, spindle oil and the like. As the resin, rosin, shellac, copal, dammar, gilsonite, zein, lime rosin, ester gum, phenol resin, xylene resin, urea resin, melamine resin, ketone resin, coumarone / indene resin, petroleum resin, terpene resin, Cyclized rubber, chlorinated rubber, alkyd resin, polyamide resin, acrylic resin, polyvinyl chloride, vinyl chloride / vinyl acetate copolymer resin, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, chlorinated polypropylene, styrene resin, epoxy resin, polyurethane And cellulose derivatives.

Examples of the dispersion solvent include n-hexane, n-heptane, toluene, xylene, methyl alcohol, isopropyl alcohol, ethylene glycol, triethylene glycol, diethylene glycol, glycerin, methyl cellosolve, carbitol, ethyl acetate, acetone, and methyl ethyl ketone. It is done.
Examples of additives include waxes, dryers, dispersants, wetting agents, crosslinking agents, stabilizers, thickeners, gelling agents, bubble erasing agents, and photopolymerization initiators.

(Hot melt magnetic ink)
In the case of hot melt magnetic ink, it is obtained with a composition comprising a magnetic material, a dye, a hot melt vehicle, and an additive. In this case, specific examples of the hot melt vehicle include carnauba wax, beeswax, anhydrous lanolin, paraffin wax, montan wax, ozokerite, ceresin, petrolatum, polyethylene wax, chlorinated paraffin, fatty acid amide, phenyl salicylate, triphenyl phosphate, p- Examples thereof include n-heptyl hydroxybenzoate and dicyclohexyl phthalate. Specific examples of the pigment and the additive include those similar to the case of the oil-based magnetic ink.

(Water-based magnetic ink)
In the case of water-based magnetic ink, it is obtained with a composition comprising a vehicle in which a magnetic material, a dye, a resin, a water-solubilizing agent, a co-solvent, water and the like are combined, and an additive. In this case, specific examples of the pigment include those similar to the case of the oil-based magnetic ink.

Specific examples of the resin include starch, dextrin, alginate, cellulose ester, polyvinyl alcohol, polyacrylamide, polyethylene oxide, shellac, styrenated shellac, rosin maleic acid resin, casein, acrylic copolymer, vinyl acetate resin, chloride Vinyl resin, synthetic rubber latex, polyurethane, polyester, alkyd resin, rosin ester, epoxy ester and the like can be mentioned. Examples of the water solubilizer include aqueous ammonia, monoethanolamine, monoisopropanolamine, ethyl monoethanolamine, diethylethanolamine, dimethylethanolamine, morpholine, and the like. Examples of the cosolvent include ethyl alcohol, isopropyl alcohol, ethyl acetate, and methyl ethyl ketone.
Examples of the additive include an antiwear agent such as petroleum wax and polyethylene wax, and a deionizer such as a nonionic active agent, silicone and alcohol.

The magnetic ink composition thus obtained can be used for an inkjet printer, a thermal transfer, a hot melt printer, a writing instrument, and the like. In addition, magnetic signals can be added by the magnetic substance contained, and reading by a magnetic head is possible. Printing of magnetic cards such as certificates and tickets, printing of banknotes, addition of information such as confidential documents, or information It can also be used for maintenance. The printing at that time can be colored. Furthermore, since the magnetic material has good compatibility with a resin or the like, it has good dispersibility and is less likely to cause cracks after printing.
Further, the magnetic ink composition of the present invention can be used for the production of a multilayer coating film by utilizing its magnetic properties. When forming a multilayer coating film, a magnetic ink composition and a general thermoplastic resin such as polyester resin, polyester urethane resin, and acrylic resin and / or various active energy ray curable compounds are used. That's fine.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
In addition, g value (radical concentration) and saturation magnetic susceptibility of the organic magnetic material obtained in each example were measured according to the following methods.

(1) g value (radical concentration)
Using an ESR spectrum measuring apparatus “JES-FA” (manufactured by JEOL Ltd.), an organic magnetic material solution obtained in the examples is filled in a tissue cell, and a sample for analysis is prepared. (About 100K) ESR spectrum was measured to determine g value (radical concentration).
(2) Saturation magnetic susceptibility An analytical sample was prepared by filling the organic magnetic material solution obtained in the examples into a measurement cell, and using a magnetic susceptibility measurement device “BH analyzer SY8232” (manufactured by Iwasaki Tsushinki Co., Ltd.) The saturation magnetic susceptibility was measured at room temperature.

<Example 1>
As a dopant, 4.5 g of imidazolium dicyanamid ionic liquid is used as a dopant with respect to 1.0 g in terms of solid content of nitromethane solution of polythiophene (weight average molecular weight: about 30,000, manufactured by Sigma-Aldrich) as a π-electron conjugated polymer. In addition, after stirring at room temperature for 1 hour, impurities such as precipitates and dust were filtered off to obtain an organic magnetic material solution. Table 1 shows the measurement results of g value (radical concentration) and saturation magnetic susceptibility.

<Example 2>
In Example 1, an experiment was conducted in the same manner as in Example 1 except that a pyrrolidinium dicyanamide ionic liquid was used instead of the imidazolium dicyanamide ionic liquid as a dopant. The dicyanamid anion and the counter cation 450 mass part) were obtained with respect to 100 mass parts of polymers. Table 1 shows the measurement results of g value (radical concentration) and saturation magnetic susceptibility.

<Example 3>
As a dopant, imidazolium dicyanamide ionic liquid 5.2 g with respect to 1.0 g of toluene solution solid content of polyphenine vinylene (weight average molecular weight: 50,000, manufactured by Sigma-Aldrich) as a π-electron conjugated polymer. After stirring at room temperature for 1 hour, impurities such as precipitates and dust were separated by filtration to obtain an organic magnetic material solution. Table 1 shows the measurement results of g value (radical concentration) and saturation magnetic susceptibility.

<Example 4>
As a dopant, 3.5 g of an imidazolium dicyanamid ionic liquid is used as a dopant with respect to 1.0 g of a toluene solution solid content of oligothiophene (thiophene hexamer: molecular weight 663, manufactured by Sigma-Aldrich) as a π-electron conjugated polymer. After stirring at room temperature for 1 hour, impurities such as precipitates and dust were filtered off to obtain an organic magnetic material solution. Table 1 shows the measurement results of g value (radical concentration) and saturation magnetic susceptibility.

<Comparative Example 1>
In Example 1, experiments and measurements were performed in the same manner as in Example 1 except that the imidazolium dicyanamid ionic liquid as a dopant was not used. The results are shown in Table 1.

<Comparative example 2>
In Example 1, an experiment was conducted in the same manner as in Example 1 except that iodine (manufactured by Kanto Chemical Co., Inc.) was used as the dopant instead of the imidazolium dicyanamid ionic liquid, and an organic magnetic material (π-electron conjugate) was used. The dicyanamid anion 450 mass parts was obtained with respect to 100 mass parts of a polymer. Table 1 shows the measurement results of g value (radical concentration) and saturation magnetic susceptibility.

<Comparative Example 3>
In Example 1, an experiment was conducted in the same manner as in Example 1 except that p-toluenesulfonic acid (manufactured by Kanto Chemical Co., Inc.) was used in place of the imidazolium dicyanamide ionic liquid as a dopant. (450 mass parts of dicyanamid anions with respect to 100 mass parts of (pi) electron conjugated polymers) was obtained. Table 1 shows the measurement results of g value (radical concentration) and saturation magnetic susceptibility.

¹⁾ Hexyl-substituted polythiophene (weight average molecular weight 30,000, manufactured by Sigma-Aldrich)
²⁾ Polyphenylene vinylene substituted with methoxy group and ethylhexyloxy group (weight average molecular weight 50,000, manufactured by Sigma-Aldrich)
³⁾ Hexyl-substituted oligothiophene (weight average molecular weight 10,000, manufactured by Sigma-Aldrich)
⁴⁾ Hexylmethylimidazolium dicyanamid (manufactured by Kanto Chemical Co., Inc.)
⁵⁾ Butylmethylpyrrolidinium dicyanamid (manufactured by Kanto Chemical Co., Inc.)

As can be seen from Table 1, all of the organic magnetic materials of Examples 1 to 3 have a high g value of 10 ¹⁶ / g level and a high saturation magnetic susceptibility of 9.8 to 12.2 emu / g. In Example 4, since oligothiophene was used as the π-electron conjugated polymer, both the g value and the saturation magnetic susceptibility were slightly lower than those in Examples 1 to 3, but the g value was still close to 10 ¹⁶ / g. Obtained.
Comparing Comparative Example 1 and Example 1, Comparative Example 1 that is not doped has a much lower g value and saturation magnetic susceptibility than Example 1.
Further, in Comparative Examples 2 and 3, comparing Example 1, it can be seen that the anion species other than the dicyanamid anion has a g value of 10 ¹⁵ / g level and the saturation magnetic susceptibility is much lower than that of Example 1. .
From the above, it can be seen that when an organic magnetic material having a dicyanamid anion is used, the g value and the saturation magnetic susceptibility are particularly excellent.

<Example 5> Preparation of magnetic ink composition and production of multilayer coating film using the same 2.0 g of dipentaerythritol hexaacrylate (manufactured by Kanto Chemical Co., Inc., hard coat material) which is a polyfunctional photopolymerizable monomer A non-magnetic material composed of 0.1 g of a photopolymerization initiator “Irgacure (registered trademark) 184” (manufactured by Ciba Specialty Chemicals) and 10.0 g of the organic magnetic material solution obtained in Example 1 were stirred and mixed at room temperature. A clear and uniform magnetic ink composition was prepared.
(Manufacture of multilayer coating film)
Immediately after the magnetic ink composition was coated on a polyethylene terephthalate (PET) film “Cosmo Shine (registered trademark) A100” (manufactured by Toyobo Co., Ltd.) having a thickness of 100 μm as a substrate, a magnetic field strength of about 5500 gauss The permanent magnet was passed between the permanent magnets (gap: 1.2 cm) slowly (speed: 10 cm / sec) together with the PET substrate, and magnetic treatment was performed. Thereafter, it was dried in an oven at 70 ° C. for 3 minutes to form a coating layer. Next, the coating layer was cured by irradiating it with ultraviolet rays at a light amount of 100 mJ / cm ² to produce a transparent coating film 1 having a thickness of about 1.5 μm on the PET film.
About this coating film 1, when the component on the coating film surface side and the substrate side was examined by slab type optical waveguide spectroscopy, the absorption peak derived from polythiophene was strongly observed on the coating film surface side (upper surface side), It was found that a phase separation structure having a magnetic material on the coating film surface could be formed.

The organic magnetic material of the present invention can obtain a g value (radical concentration) of 10 ¹⁶ / g level and a saturation magnetic susceptibility of 7.0 emu / g or more, and has good reproducibility, as compared with an inorganic magnetic material. It has advantages such as low density, good dispersibility in binder resin, and many white or light colors, including magnetic inks, acoustic materials, electrical machinery, electronics field, automotive field, medical field, magnetic recording It can be widely used in many fields such as fields.

Claims (8)

  An organic magnetic material comprising a π-electron conjugated polymer and a dicyanamid anion. The dicyanamid anion is represented by the following general formula (I)
(Z ^{a +} ) _{m ′} ([(CN) ₂ N] ⁻ ) _n (I)
(Wherein, Z a ⁺ is a cation, a, m and n are each an integer of 1 to 3, when a plurality .Z a ⁺ is to satisfy the relation of a × m = n, ⁺ the plurality of Z ^a be the same or different May be.)
The organic magnetic material according to claim 1, which is contained in the form of an ionic liquid represented by: ^{Za +} cations in the ionic liquid represented by the general formula (I) are represented by the following formulas (Ia), (Ib), (Ic) and (Id):

[R ^{1 in} Formula (Ia) represents a hydrocarbon group having 4 to 20 carbon atoms and may include a hetero atom, and R ² and R ³ are each independently a hydrogen atom or a carbon number of 1 to 16 carbon atoms. And may contain a hetero atom. However, when the nitrogen atom contains a double bond, there is no R ³ .
R ^{4 in} formula (Ib) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a hetero atom, and R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom or a carbon atom having 1 carbon atom. Represents ˜16 hydrocarbon groups and may contain heteroatoms.
R ⁸ in the formula (Ic) represents a hydrocarbon group having 2 to 20 carbon atoms and may contain a hetero atom, and R ⁹ , R ¹⁰ and R ¹¹ are each independently a hydrogen atom or a carbon atom having 1 carbon atom. Represents ˜16 hydrocarbon groups and may contain heteroatoms.
E in the formula (Id) represents a nitrogen, sulfur, or phosphorus atom, R ¹² , R ¹³ , R ^14, and R ¹⁵ each independently represents a hydrocarbon group having 1 to 20 carbon atoms; It may contain atoms. However, when E is a sulfur atom, there is no R ¹⁵ . ]
The organic magnetic material according to claim 1, wherein the organic magnetic material is at least one selected from cations represented by:   The organic magnetic material according to claim 1, wherein the π-electron conjugated polymer is at least one selected from polythiophene, oligothiophene, polyaniline, polypyrrole, polyphenylene vinylene, and derivatives thereof.   The organic magnetic material according to claim 4, wherein the π-electron conjugated polymer is polythiophene or a derivative thereof.   The organic magnetic material according to any one of claims 1 to 5, comprising 100 to 600 parts by mass of the dicyanamid anion and the counter cation with respect to 100 parts by mass of the π-electron conjugated polymer.   A method for producing an organic magnetic material, comprising doping an π-electron conjugated polymer using an ionic liquid having a dicyanamid anion as an anion species.   A magnetic ink composition comprising the organic magnetic material according to claim 1.