JPH07138507A - Magnetic ink - Google Patents

Abstract

PURPOSE:To provide the magnetic ink which is excellent in compatibility with and dispersibility in a resin, etc., and enables magnetic reading by mixing a specific magnetic material with a colorant and a vehicle. CONSTITUTION:A magnetic material which comprises either a thiophene polymer substituted with a nitroxide radical and represented by formula I (wherein X is O, S, or NH and Y is an alkyl) or an acetylene polymer substituted with a verdazyl and represented by formula II (wherein R, R', and R'' each is an alkyl or aryl) and has a spin concentration of 10<17> ger g or higher is mixed with a colorant and a vehicle comprising, e.g. an oil, a resin, and a solvent as a dispersion medium. According to need, additives such as a wax, a drier, a dispersant, a wetting agent, a crosslinking agent, a stabilizer, a thickener, a gellant, a defoaming agent, and a photopolymerization initiator are incorporated into the mixture.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic ink useful for printing, ink jet printers, thermal transfer ribbons, halt melt printers, writing instruments and the like.

[0002]

2. Description of the Related Art Magnetic inks generally include magnetic substances, pigments,
It is composed of a vehicle in which a resin, a dispersion solvent and the like are combined, additives and the like, and is used for oil-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 (JP-A-59-147217),
An ink in which a magnetic substance is dispersed in wax (Japanese Patent Laid-Open No. 62-2
No. 67379) is known.

[0003]

However, in these magnetic inks, the magnetic substance is ferrite, chromium oxide, Mn-B.
i alloy, Sn-Al alloy, Fe-Ni alloy, Sn-Fe
Since it is made of a metal oxide such as an alloy, the compatibility between the magnetic substance and the vehicle or the like is poor, and the magnetic substance is apt to aggregate, resulting in poor dispersibility. Further, cracks are likely to occur after image formation, that is, after the magnetic ink has dried.

The present invention has been made in view of the above points, and an object thereof is to obtain a magnetic ink which is excellent in compatibility and dispersibility with a resin and the like and which is composed of a magnetic material which can be read magnetically. .

[0005]

According to the present invention, firstly, in a magnetic ink containing a magnetic substance, a dye and a vehicle as main components, a nitroxide radical substitution represented by the following general formula (I) is used as the magnetic substance. A magnetic ink using a thiophene polymer or a ferdazyl-substituted acetylene polymer represented by the following general formula (II) is provided.

[Chemical 1] (In the formula, X represents one selected from the group consisting of O, S and NH, and Y represents an alkyl group.)

[Chemical 2] (In the formula, R, R ′, and R ″ represent an alkyl or aryl group.) Secondly, in the above first magnetic ink,
Provided is a magnetic ink in which the polymer represented by the general formula (I) or (II) serves both as a magnetic substance and a polymer. Thirdly, in the first or second magnetic ink, there is provided a magnetic ink in which the polymer represented by the general formula (I) or (II) has a spin concentration of 10 ¹⁷ / g or more.

Since the nitroxide radical-substituted thiophene polymer represented by the general formula (I) and the ferdazyl-substituted acetylene polymer represented by the general formula (II) in the present invention are both organic magnetic substances, they are organic components of magnetic ink. It has good compatibility with, is light and non-scattering, and has a light green color instead of a dark color like an inorganic magnetic material, so it is useful as a magnetic material component of magnetic ink, and a clear image can be obtained. it can.

The organic magnetic material represented by the general formula (I) can be produced, for example, in the following reaction step according to the method described in Japanese Patent Application No. 4-358163 proposed above. That is, the polyalane, polythiophene or polypyrrole derivative represented by the general formula (I) can be obtained by oxidizing the hydroxyl group of the polyfuran, polythiophene or polypyrrole derivative represented by the following formula (III).

[Chemical 3] (In the formula, X and Y are the same as above.) As a method for this oxidation treatment, a method using an oxidizing agent such as Ag ₂ O, K ₈ Fe (CN) ₄ or an alkali such as potassium hydroxide is used. Air oxidation of. The reaction temperature is preferably about 0 ° C.

The polyfuran, polythiophene or polypyrrole derivative having the repeating unit represented by the above formula (III) can be produced, for example, by a method according to the following reaction formula.

[Chemical 4] (In the above formula, X and Y are the same as above. Z represents a halogen atom. N is the degree of polymerization.)

The organic magnetic material represented by the general formula (II) can be obtained, for example, by the following method.

[Chemical 5]

The organic magnetic material of the present invention may have an appropriate spin concentration within the range necessary for exhibiting magnetism, and is usually 10 ¹⁷ / g or more.

The magnetism of the organic magnetic material can be confirmed as follows. As a simple method, there is a method in which a permanent magnet is arranged below a petri dish into which water is poured, and the organic magnetic powder is floated below the water surface. The magnetism can be confirmed by the powder under the water gathering at the place where the magnetic flux density of the magnet is high. The magnetic activity of the present invention was also confirmed by this method.

The magnetic ink of the present invention can be used as an oil-based, water-based or hot-melt ink. The constituent materials other than the organic magnetic material used in each ink will be described below.

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

The vehicle is composed of oil, resin, dispersion solvent and the like. Specific examples of the oil include linseed oil, shinai oil, soybean oil, castor oil, dehydrated castor oil, lysovarnish, maleated oil and vinylated oil. Oils, urethane oils, machine oils, spindle oils and the like can be mentioned. As the resin, rosin, shellac, copal, dammar, gilsonite,
Zein, lime rosin, ester gum, phenolic resin,
Xylene resin, urea resin, melamine resin, ketone resin,
Coumaron / 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,
Examples thereof include polyvinyl butyral, chlorinated polypropylene, styrene resin, epoxy resin, polyurethane, and cellulose derivative.

As the dispersion solvent, n-hexane, n-heptane, toluene, xylene, methyl alcohol, isopropyl alcohol, ethylene glycol, triethylene glycol, diethylene glycol, glycerin, methyl cellosolve, carbitol, ethyl acetate, acetone, methyl ethyl. Examples include meketone.

Examples of the additives include waxes, dryers, dispersants, wetting agents, cross-linking agents, stabilizers, thickeners, gelling agents, defoamers and photopolymerization initiators.

In this oil-based magnetic ink, it is preferable to select and use one that can be used in combination with the organic magnetic material as a vehicle, because the number of components can be reduced.

(2) 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, shoe wax,
Anhydrous lanolin, paraffin wax, montan wax, ozokerite, ceresin, petrolatum, polyethylene wax,
Chlorinated paraffin, fatty acid amide, phenyl salicylate,
Examples thereof include triphenyl phosphate, n-heptyl p-hydroxybenzoate, and dicyclohexyl phthalate. Specific examples of the dye and the additive include those similar to the case of the oil-based magnetic ink.

(3) Aqueous 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 cosolvent and water are combined, and an additive. In this case, as a specific example of the dye, the same one as in the case of the oil-based magnetic ink can be mentioned.

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. Resin, vinyl chloride resin, synthetic rubber latex, polyurethane, polyester, alkyd resin, rosin ester,
An epoxy ester etc. are mentioned. As the water-solubilizing agent, ammonia water, monoethanolamine, monoisopropynolamine, ethylmonoethanolamine,
Diethyl ethanol amine, dimethyl ethanol amine, morpholine and the like can be mentioned, and as a cosolvent,
Examples thereof include ethyl alcohol, isopropyl alcohol, ethyl acetate, methyl ethyl ketone and the like.

The additives include petroleum wax,
Examples include abrasion resistance improvers such as polyethylene wax, nonionic activators, and defoamers such as silicones and alcohols.

[0022]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

[Synthesis Example 1] (A) Synthesis of poly (3-bromothiophene) 3-Bromothiophene 10 was added to a solution prepared by dissolving 120 parts of ferric chloride in 2000 parts of chloroform with stirring at 0 ° C.
After gradually dropping, the mixture was stirred for 1 hour and further stirred at 30 ° C. for 1 hour. The reaction solution was poured into a large amount of methanol, the precipitate was collected by filtration, the product was thoroughly washed with methanol and then with a methanol / water (1: 1) solution, and diluted ammonia and methanol / water (1: 1) solution were added. Dedope treatment and dry to give poly (3-bromothiophene) as a reddish orange solid
Got The elemental analysis value of the product is shown next, and the infrared absorption spectrum is shown in FIG. C H S Br Elemental analysis value 29.88 1.21 19.51 48.91 Calculated value 29.76 0.92 19.82 49.49

(B) Synthesis of poly (3-N-tert-butylhydroxylaminothiophene) 10 parts of poly (3-bromothiophene) was dissolved in 30 parts of ether, and 6 parts of butyllithium (hexane solution 1.
6) was added, and then 1.4 parts of 2-methyl-2-nitrosopropane dimer was added and stirred for 2 hours. The reaction was terminated with dilute aqueous ammonium chloride solution, and the precipitated product was collected by filtration, washed with water and methanol in this order, and dried to obtain poly (3
-N-tert-butylhydroxylaminothiophene) was obtained. The elemental analysis values of the product were as follows. C H S N Elemental analysis value 55.21 7.11 18.48 7.94 Calculated value 56.77 6.55 18.95 8.28

(C) Synthesis of poly (3-N-tert-butyl nitroxide thiophene) 10 parts of poly (3-tert-butylhydroxylaminothiophene) and 150 parts of silver oxide were added to carbon tetrachloride / methanol (2: 1). The reaction was carried out at 0 ° C. for 10 hours. The reaction liquid was poured into a large amount of water / methanol (1: 1) liquid, and the precipitated polymer was collected by filtration. It was thoroughly washed with water and methanol in this order and then dried. Poly (3-N-tert) as a brown solid
-Butyl nitroxide thiophene) was obtained. The infrared absorption spectrum of the product is shown in FIG.

[Synthesis Example 2] Synthesis of Feldazyl-Substituted Acetylene Polymer The Feldazyl-substituted acetylene polymer can be prepared according to the following reaction steps.

[0027]

[Chemical 6]

Compound (XI) was obtained as a light green solid by the above reaction formula. The elemental analysis values are shown next, and the electronic spectrum is shown in FIG. CHN elemental analysis value 77.89 5.65 16.46 calculated value 78.32 5.08 16.60

Example 1 Aniline Black 25% Xylene Resin 20% Machine Oil 30% Toluene 13% Candelilla Wax 5% Soybean Oil Fatty Acid 2% The ink obtained by the formulation of the compound 5% obtained in Synthesis Example 1 was used. The resulting printed matter was clear and had a very good image, and magnetically readable.

Example 2 Phthalocyanine blue 3.5% n-Heptyl p-hydroxybenzoate 92.5% The compound obtained in Synthesis Example 1 4.0% was sufficiently mixed and dissolved, and filtered with a membrane filter. Then, hot melt magnetic ink was obtained. When an ink-jet printer was used to print with the obtained ink, the obtained printed matter was clear and had a very good image. It was also possible to read magnetically.

Example 3 Laked C 15.0% Shellac aqueous varnish 60.0% Polyethylene wax 4.0% Water 15.5% Silicone 0.5% Compound obtained in Synthesis Example 1 5.0% An aqueous magnetic ink was obtained by mixing (the composition of the above shellac aqueous varnish was 33% shellac, 2% diethylethanolamine, 13% ethanol, 52% water).
Is). When printing was performed using the obtained ink, the obtained printed matter was clear, had a very good image, and was magnetically readable.

Example 4 Aniline Black 25% Xylene Resin 20% Machine Oil 30% Toluene 13% Candelilla Wax 5% Soybean Oil Fatty Acid 2% The ink obtained by the formulation of the compound 5% obtained in Synthesis Example 2 was used. The resulting printed matter was clear, had a very good image, and was magnetically readable.

Example 5 Phthalocyanine blue 3.5% n-heptyl p-hydroxybenzoate 92.5% The compound obtained in Synthesis Example 2 4.0% was thoroughly mixed and dissolved in a formulation and filtered through a membrane filter. Then, hot melt magnetic ink was obtained. When an ink-jet printer was used to print with the obtained ink, the obtained printed matter was clear and had a very good image. It was also possible to read magnetically.

Example 6 Laked C 15.0% Shellac aqueous varnish 60.0% Polyethylene wax 4.0% Water 15.5% Silicone 0.5% Compound obtained in Synthesis Example 2 5.0% An aqueous magnetic ink was obtained by mixing (the composition of the above shellac aqueous varnish was 33% shellac, 2% diethylethanolamine, 13% ethanol, 52% water).
Is). When printing was performed using the obtained ink, the obtained printed matter was clear, had a very good image, and was magnetically readable.

[0035]

As described above, the magnetic ink of the present invention is
By using a nitroxyl radical-substituted thiophene polymer or a ferdazyl-substituted acetylene polymer as the magnetic substance, compatibility with the resin is good, and dispersibility in the resin is also excellent, so that a clear and high-quality image can be obtained. Further, the obtained printed matter can be read magnetically, and its fields of use are wide, such as printing of certificates, tickets, bills, etc., addition of information such as secret documents, maintenance, etc.

[Brief description of drawings]

FIG. 1 is a diagram showing an infrared absorption spectrum of poly (3-bromothiophene).

FIG. 2 is a diagram showing an infrared absorption spectrum of poly (3-N-tert-butylnitrooxidethiophene).

FIG. 3 is a diagram showing an electronic spectrum of a ferdazyl-substituted acetylene polymer.

Claims (3)

[Claims] 1. A magnetic ink containing a magnetic substance, a dye and a vehicle as main components, wherein the magnetic substance is a nitroxide radical-substituted thiophene polymer represented by the following general formula (I) or a ferdazyl substitution represented by the following general formula (II). Magnetic ink using acetylene polymer. [Chemical 1] (In the formula, X represents one selected from the group consisting of O, S and NH, and Y represents an alkyl group.) (In the formula, R, R ′ and R ″ represent an alkyl or aryl group.) 2. The magnetic ink according to claim 1, wherein the polymer represented by the general formula (I) or (II) serves both as a magnetic substance and a polymer. 3. The polymer represented by formula (I) or (II) has a spin concentration of 10 ¹⁷ / g or more.
Or the magnetic ink according to item 2.