JPH10168339A - Colored magnetic metal flake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain colored magnetic metal flakes forming particles having a prescribed particle size or less, when added to a coating, free from coagulation, giving excellent contrasts and designs and useful for magnetic display media, etc. SOLUTION: The colored magnetic metal flakes are obtained by sticking a coloring pigment, such as a phthalocyanine pigment, coated with an amino compound (e.g. ethylenediamine) having two amino groups in the molecule and not having a carboxyl group to at least 90% of the surfaces of all the magnetic metal flakes, form particles having sizes of <=90μm (measured by JIS 5400 B method), when added to a coating, and have the maximum flake size of 150μm, an average thickness of 0.1-5μm and a median diameter of 5-100μm. The coloring pigment is preferably coated with a monobasic aromatic carboxylic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a colored magnetic metal flake used for a magnetic card or a magnetic display medium, and for a paint for forming a magnetic pattern.

[0002]

2. Description of the Related Art Magnetic metal flakes such as permalloy, sendust, and silicon steel are used for a shielding layer of a magnetic card such as a pachinko card or a recording layer of a magnetic display medium such as a rewritable card. All of these magnetic metal flakes have only a dull metallic color and have little decorative effect. Further, when characters and the like are printed from above the shielding layer, there is a problem that the printed characters and the like are difficult to read because the base is a dull metal color. In order to solve this, a method of providing a protective layer containing titanium oxide, aluminum flake, or the like on the shielding layer has been adopted. However, there is a problem that the number of steps is increased and the cost is increased.

On the other hand, a method of displaying a visible image by enclosing these magnetic metal flakes in a microcapsule together with a liquid and orienting them by magnetism has been used for magnetic display media such as rewritable cards. In this case, the use of ordinary magnetic metal flakes only gives a dull metallic color and has poor contrast, making it difficult to obtain a clear image. In addition, the colors of displayed characters are limited.

JP-A-63-175670, JP-A-06-175670
-86958 discloses a method of forming a magnetic pattern having a three-dimensional effect by applying a magnetic force in a step of applying a paint containing a magnetic powder. However, at present, there is a problem that the color is poor and the design is inferior because only a dull metallic magnetic powder which is not colored is used.

Several methods have been proposed for coloring magnetic powders used in these applications.

For example, JP-A-4-199085 discloses a method of coloring a magnetic fluid with a dye by a phase separation method or an interfacial polymerization method. However, in these methods, when the magnetic powder is coated with the resin, it tends to aggregate and become coarse particles, and even if the aggregated particles are magnetically oriented, a clear image cannot be obtained. There are problems such as the occurrence of bumps when painted. In addition, there is a disadvantage that the dye is poor in stability and cannot be used for a long time.

Japanese Patent Application Laid-Open No. Hei 7-13206 discloses a method of coloring flaky magnetic powder with a silicon dioxide film to which an organic coloring agent is fixed. Also in this method, there is a problem that it is difficult to avoid agglomeration of the magnetic powder in the step of forming the silicon dioxide film, and if the silicon dioxide film is made thinner to avoid the aggregation, it cannot be sufficiently colored.

Japanese Patent Application Laid-Open No. Hei 7-261684 discloses a method of coloring a magnetic powder, which comprises a phase separation method, a submerged hard coating method,
Dispersion polymerization, impact in a stream, spray drying, and a method of coloring an organic metal or metal salt with a metal oxide that is decomposed and precipitated on the particle surface are disclosed. However, in the method (1), the resin is likely to form a lump, so that the aggregation of the magnetic powder is also unavoidable. In the method (1), it is difficult to firmly attach the color pigment to the magnetic powder, and there is a problem that the pigment is immediately dropped off in the process of producing a paint or ink.
In addition, in the method, it is difficult to efficiently attach the pigment to the surface of the magnetic powder, so that the pigment cannot be sufficiently colored. In the method, the coloring power of the metal oxide is small, so that the pigment cannot be sufficiently colored, or can be colored. However, there is a problem that the hue is limited.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a non-agglomerated magnetic metal flake to which a color pigment is uniformly adhered, which is used for a magnetic card or a magnetic display medium, and further for a magnetic pattern. It is intended to provide a design function in addition to the conventional functions for forming paints.

[0010]

A desirable state of the attached state of the colored pigment is that the colored pigment is attached to at least 90% of the magnetic metal flakes of all the particles, and the magnetic metal to which the colored pigment is not attached is attached. When there are many flakes, direct reflection of light from the particles impairs the sharpness of the color tone. In addition, it is desirable that the coloring pigment is firmly adhered. If the adhesion is insufficient, when the coloring pigment is used for the above-mentioned application, the coloring pigment is dropped off in the process of producing them, and the coloring pigment is adhered. Unwanted magnetic metal flakes may occur, in which case the sharpness of the color tone is impaired.

[0011] The colored magnetic metal flakes of the present invention do not contain agglomerated particles, and the coating material containing the colored magnetic metal flakes has a value measured by the crush test B method specified in JIS 5400 of 90 µm or less. I do. Here, the agglomerated particles refer to those in which a plurality of magnetic metal flakes are fixed to form one block particle, and when such particles are present and the measured value by the crush test B method exceeds 90 μm, There is a problem in that the shielding layer or the coating film becomes uneven, or the sharpness of the image is impaired by magnetism. Such colored magnetic metal flakes containing no aggregated particles could not be obtained by conventional techniques.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The magnetic metal flakes serving as a base material have a maximum particle size of 150 μm or less (more preferably 5 μm or less).
0 μm or less), an average thickness of 0.1 to 5 μm (more preferably 0.2 to 1 μm), and a median diameter of 5 to 100 μm.
(More preferably 10 to 40 μm), and a shape factor obtained by dividing the average particle size by the thickness is in the range of about 2 to 500 (more preferably 5 to 100). The shape is preferably a coin-like shape having a smooth surface and rounded edges. If the maximum particle size is more than 150 μm, problems occur such as blemishes when printed and encapsulation is impossible, and the same problem occurs when the median diameter is larger than the above range. On the other hand, when the average thickness is larger than the above range, the painted surface becomes rough and the design is impaired. Further, when the median diameter and the average thickness are smaller than the above ranges, coloring does not have much characteristic in design, and coloring becomes difficult because many pigments need to be adhered.

Here, the maximum particle size (r) is defined as the smallest sieve opening at which the sieve residue is 0.1% or less in a sieving analysis, and the median diameter (Dm) is defined as a laser diffraction method or sieving. The median diameter and average thickness (t) in the particle size distribution measured by the method or microscopy are determined by the water surface diffusion area method or a method similar thereto (for example, by preparing a coating film having a dilute concentration of a sample and measuring the transmittance thereof, Method of estimating water surface diffusion area using a calibration curve created using a sample with a known diffusion area)
In the measured hiding power (S, cm ² / g) and the true density of the colored magnetic metal flakes (ρ, g / cm ³⁾ can be calculated from using the following equation.

T (μm) = 10 ⁴ / (ρ × S) The material of the magnetic metal flake is a soft magnetic material, a semi-hard magnetic material, or a metal material belonging to a hard magnetic material, and has a ductility enough to be flaked. Are preferably used. Specific examples include iron, nickel, cobalt, chromium, and alloys thereof, silicon steel, permalloy, sendust, alnico, magnetic stainless steel, and the like.

The amount of the coloring pigment to be attached is suitably in the range of 1 to 100 parts by weight based on 100 parts by weight of the magnetic metal flake. If the amount is less than this, coloring cannot be performed sufficiently. If the amount is too large, the coloring pigment tends to fall off.

According to the present invention, the coloring pigment can be used irrespective of whether it is organic or inorganic. Specific examples of the pigment that can be used include the following pigments.

Phthalocyanine, halogenated phthalocyanine, quinacridone, diketopyrrolopyrrole, isoindolinone, azomethine metal complex, indanthrone, perylene, perinone, anthraquinone, dioxazine, benzimidazolone, condensed azo, triphenylmethane, quinophthalone, anthra Pyrimidine, titanium oxide, iron oxide, carbon black, ultramarine, navy blue, cobalt blue, chrome green.

Particularly preferred pigments in terms of adhesion, weather resistance and coloring power include phthalocyanine blue, phthalocyanine green, quinacridone red, quinacridone maroon, quinacridone gold, diketopyrrolopyrrole, isoindolinone yellow, isoindolinone orange, Examples include anthrapyrimidine yellow, dioxazine violet, perylene maroon, azomethine copper complex, ultrafine titanium oxide, transparent iron oxide, and carbon black.

The primary particle size of the color pigment is 0.0
Those having a thickness of 1 to 1 μm, preferably 0.02 to 0.1 μm can be used.

As a method of adhering the color pigment to the surface of the magnetic metal flake, the color pigment to be adhering is used in a molecule.
The color pigment is coated with an amino compound having two amino groups and no carboxyl group and / or a monobasic aromatic carboxylic acid to improve the adhesion to magnetic metal flakes, A method of attaching to magnetic metal flakes using a hetero-aggregation phenomenon in a solvent is preferable.

In addition to the above compounds, a pigment dispersant such as a surfactant or a chelate compound, or an ultraviolet absorber may be attached to the color pigment.

Examples of an amino compound having two amino groups and no carboxyl group include the following.

Ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, dodecamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,10-diaminodecane, 1,12- Diaminododecane, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 1,8-diaminonaphthalene, 1,2-diaminocyclohexane, stearylpropylenediamine, N-β- (aminoethyl) -γ
-Aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane.

Among these, aliphatic diamines having 6 to 12 carbon atoms, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β- (aminoethyl)
When the color pigment is treated and coated with at least one selected from the group of -γ-aminopropyltrimethoxysilane, it is particularly excellent in adhesion to magnetic metal flakes and is suitable.

The following are examples of the monobasic aromatic carboxylic acid.

Benzoic acid, vinyl benzoate, salicylic acid,
Anthranilic acid, m-aminobenzoic acid, p-aminobenzoic acid, 3-amino-4-methylbenzoic acid, p-aminosalicylic acid, 1-naphthoic acid, 2-naphthoic acid, naphthenic acid, 3-amino-2-naphthoic acid Acid, cinnamic acid, aminocinnamic acid.

Among these, benzoic acid, aminobenzoic acid (anthranilic acid, etc.), aminohydroxybenzoic acid (aminosalicylic acid, etc.), naphthoic acid (2-naphthoic acid, etc.), aminonaphthoic acid (3-amino-2-acid) Those belonging to naphthoic acid, etc.), cinnamic acid and aminocinnamic acid are particularly excellent in the adhesion between the magnetic metal flakes and the coloring pigment, and are preferred.

The amount of the amino compound having two amino groups and no carboxyl group or the monobasic aromatic carboxylic acid to be added is 0.2 to 1 per 100 parts by weight of the coloring pigment.
00 parts by weight, more preferably 0.5 to 50 parts by weight is suitable. If the addition amount is too small, it becomes difficult to attach the coloring pigment to the magnetic metal flake. On the other hand, if the addition amount is too large, the pigment cannot be sufficiently fixed even when the coloring pigment is adhered to the magnetic metal flake.If the coloring magnetic metal flake is mixed with the magnetic film, an extra amino compound or a monobasic aromatic carboxylic acid is added. Inconveniences such as that acid causes problems such as deterioration of physical properties of the magnetic film.

Specifically, the following steps are exemplified as a preferred method of attaching the coloring pigment to the magnetic metal flakes, but the method is not limited to this method.

1) In the presence of an amino compound having two amino groups and no carboxyl group, and / or in the presence of a monobasic aromatic carboxylic acid, the coloring pigment may be optionally used. Then, a dispersant such as a surfactant and a chelate compound is added, and the mixture is dispersed in a non-polar solvent to prepare a color pigment dispersion. Here, as the nonpolar solvent, an aliphatic hydrocarbon or an aromatic hydrocarbon having a boiling point in the range of about 100 to 250 ° C. and a mixture thereof can be suitably used. Specific examples include normal paraffin, isoparaffin, toluene, xylene, solvent naphtha, kerosene, mineral spirit, petroleum benzine, and the like. Also, if necessary, a small amount (about 5% or less) of an alcohol or ester solvent may be added as an aid for dispersing the pigment.

As a method for dispersing the color pigment, a dispersion method using a pulverizing medium such as a ball mill, a bead mill, and a sand mill is preferable.

2) To the colored pigment dispersion prepared in 1), magnetic metal flakes are added and dispersed. As the dispersion method at this time, in addition to the above-described dispersion methods using a pulverizing medium, stirring with a stirrer or a disper is also suitable. In addition, a method is also effective in which a magnetic metal flake having an inorganic acid group adsorbed thereto is added to a color pigment slurry, then solid-liquid separated to form a paste, and kneaded with a kneader mixer or the like. It is desirable that the magnetic metal flakes to be added contain as little organic additives as possible, such as fatty acids. If necessary, inorganic acids or the like may be adsorbed in advance, and the surface state may be such that the coloring pigment is easily attached.

The colored magnetic metal flakes obtained as described above are called primary colored magnetic metal flakes. The primary colored magnetic metal flake has a vivid color tone and excellent metallic luster because the colored pigment is finely and uniformly attached to the surface.

Depending on the type of the coloring pigment, it may be possible to obtain sufficient adhesion of the coloring pigment at the stage of primary coloring, but if necessary, it can be further improved by coating a resin on the pigment-adhering layer. can do. This is because the resin enters the gap between the pigment and the surface of the magnetic metal flakes and plays a role of fixing, thereby improving the adhesion. The amount of the resin to be attached is based on 100 parts by weight of the colored magnetic metal flakes.
A suitable amount is 0.5 to 100 parts by weight, more preferably 5 to 30 parts by weight. If the amount is less than this, sufficient adhesion cannot be obtained, and if it is too large, the gloss of the colored magnetic metal flakes is impaired.

The method of coating the primary colored magnetic metal flakes with a resin is as follows. The primary colored magnetic metal flakes are dispersed in a hydrocarbon-based or alcohol-based solvent (preferably a hydrocarbon-based solvent). A polymerization initiator such as isobutyl oxide and azobisisobutyronitrile is added, and the monomer is polymerized by heating with stirring,
A method of precipitating on the flake surface is preferred. The polymerization reaction is desirably performed in an oxygen-free atmosphere, for example, an inert gas such as nitrogen or argon. The reaction temperature is 50-150 ° C,
More preferably, 70 to 100 ° C is appropriate. When the temperature is too low, the polymerization reaction does not occur efficiently, and when the temperature is too high, the reaction proceeds at a stretch, so that the resin cannot be deposited on the surface of the magnetic metal flake. The reaction time is preferably about 0.5 to 24 hours. If the reaction time is too short, the monomer cannot be sufficiently polymerized, and there is no particular advantage even if the reaction time is longer than 24 hours.

The following can be exemplified as the monomer to be polymerized.

Acrylic acid, methacrylic acid, methyl methacrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate, cyclohexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxybutyl acrylate, acrylic Acid 2
-Methoxyethyl, 2-diethylaminoethyl acrylate, butyl methacrylate, octyl methacrylate, 1,
4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neopentyl glycol diacrylate,
Tripropylene glycol diacrylate, tetraethylene glycol diacrylate, trimethylolpropane triacrylate, tetramethylol methanetetraacrylate, pentaerythritol triacrylate,
Trisacryloxyethyl phosphate, ditrimethylolpropane tetraacrylate, styrene, α-methylstyrene, vinyltoluene, divinylbenzene, acrylonitrile, methacrylonitrile, vinyl acetate, vinyl propionate, maleic acid, crotonic acid, itaconic acid, polybutadiene, amaani Oil, soybean oil, epoxidized soybean oil, epoxidized polybutadiene, cyclohexene vinyl monoxide, divinylbenzene monooxide.

[0038]

[Function / Effect] By using the colored magnetic metal flakes according to the present invention, the shielding layer of the magnetic card can be arbitrarily colored, and excellent design properties can be imparted.
Further, when used for a magnetic display medium such as a rewritable card, excellent contrast can be provided, and colors can be given to displayed characters and the like. Furthermore, a clear and excellent design magnetic pattern can be obtained by forming a coating film using a paint containing the colored magnetic metal flakes of the present invention, and by applying a magnetic field to raise the magnetic pattern.

[0039]

[Examples and Comparative Examples]

-Example 1-1) Commercially available phthalocyanine-based blue color pigment (manufactured by BASF,
HELIOGEN BLUE L7072D) 20 g of N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane 10
g (50 parts by weight based on 100 parts by weight of pigment) and 100 g of mineral spirit were added, and the mixture was dispersed in a ball mill for 24 hours by a pot mill having a diameter of 10 cm and an internal volume of 500 cc into which 1 kg of a steel ball having a diameter of 3 mm was inserted.

2) Into the pot mill containing the colored pigment dispersed in 1), 111 g (100 g as metal) of permalloy flake (metal content: 90%) and 50 g of mineral spirit were inserted as a magnetic metal flake, and further ball milled for 1 hour. Dispersed. The obtained slurry was washed out with 700 g of mineral spirit to separate it from steel balls. By suction-filtering this with a magnetic funnel,
A paste-like primary colored magnetic metal flake having a solid content of 80% was obtained. The primary colored magnetic metal flakes were powdered by heating and evaporating the solvent component, and when observed with an electron microscope, the blue colored pigment was uniformly attached to each magnetic metal flake.

The primary colored magnetic metal flakes are
As a result of performing wet screening with a 49 μm sieve, the sieve residue (r) was less than 0.1% by weight. In addition, the median diameter (D
m) was 30 μm, and the average thickness (t) calculated from the hiding power was 1.0 μm.

Further, the colored magnetic metal flakes 12.
A coating test prepared by adding 40 parts by weight of a room-temperature-drying type acrylic resin varnish (Acrydic A165, Dainippon Ink and Chemicals, Inc.) to 5 parts by weight and stirring and mixing with a disper is used for a crush test B specified in JIS K5400. As a result of measuring the size of the crush by the method, the measured value was 6
It was 0 μm.

Example 2 Primary colored magnetic metal flakes 100 under the conditions of Example 1
g of the slurry containing 2.5 g of methyl methacrylate,
2.5 g of 6-hexanediol diacrylate, 2.5 g of styrene, 2.5 g of glycidyl methacrylate (total of monomers: 10 parts per 100 parts by weight of colored magnetic metal flakes)
Parts by weight), and heated at 80 ° C. in nitrogen with stirring to obtain 0.1% of azobisisobutyronitrile as a polymerization initiator.
By adding 5 g and reacting for 12 hours, the monomer was polymerized and precipitated on the surface of the colored magnetic metal flake.
After the treatment, the slurry was subjected to solid-liquid separation to obtain a paste having a solid content of 80%.

This colored magnetic metal flake is opened with an opening of 149.
As a result of wet sieving with a sieve of μm, the sieve residue was 0.1%.
% By weight. The median diameter of the colored magnetic metal flakes by a laser diffraction method was 32 μm, and the average thickness calculated from the hiding power was 1.1 μm.

A crushing test was carried out using this colored magnetic metal flake in the same manner as in Example 1, and as a result, the measured value was 80 μm.

Example 3 1) Commercially available transparent iron oxide-based yellow coloring pigment (SICO, manufactured by BASF)
TRANS GOLD L1916) To 30 g of dodecamethylenediamine 0.3 g (1 part by weight per 100 parts by weight of pigment), benzoic acid 0.3 g (1 part by weight to 100 parts by weight of pigment), dialkoxyaluminum alkyl acetoacetate as dispersant (Ajinomoto Co., Ltd., Prenact ALM) 0.06
g and 100 g of mineral spirit were added, and the mixture was dispersed in a ball mill for 24 hours by a pot mill having a diameter of 10 cm and an internal volume of 500 cc into which 1 kg of a steel ball having a diameter of 3 mm was inserted.

2) 117 g of sendust flake (metal content: 85%) as a magnetic metal flake was placed in a pot mill containing the color pigment dispersed in the ball mill of 1).
00g) and further ball mill dispersed for 1 hour. The obtained slurry was washed out with 700 g of mineral spirit to separate it from steel balls. This was suction-filtered with a glass filter to obtain a gold primary colored magnetic metal flake. Observation of the primary colored magnetic metal flakes with an electron microscope revealed that acicular pigment crystals were uniformly attached to the surface.

The primary colored magnetic metal flakes are
As a result of performing wet screening with a 49 μm sieve, the sieve residue was less than 0.1% by weight. The median diameter of the colored magnetic metal flakes measured by a laser diffraction method is 17 μm.
The average thickness calculated from the hiding power was 0.7 μm.

A crushing test was carried out using the colored magnetic metal flakes in the same manner as in Example 1. As a result, the measured value was 40 μm.

Comparative Example 1 Permalloy flakes (solid content 90%) were added to 100 g of a 5% solid content silicate sol containing 2% phthalocyanine blue.
%), And the solvent was evaporated while stirring with a rotary evaporator to color the permalloy flakes.

As a result of observing the obtained colored magnetic metal flakes with an electron microscope, a large amount of aggregated particles were observed. This magnetic metal flake was subjected to wet sieving with a sieve having an opening of 149 μm, and as a result, the residue of the sieve was 1.8% by weight. The median diameter of the colored magnetic metal flakes by a laser diffraction method was 80 μm, and the average thickness calculated from the hiding power was 6 μm.

A crushing test was carried out using the colored magnetic metal flakes in the same manner as in Example 1. As a result, the measured value was 100 μm or more.

Examples 4 to 8, 11 and Comparative Examples 2 to 4
-In the same process as in Example 1 or 3, the types of magnetic metal flakes, the type and amount of pigment, and the type and amount of treating agent for pigment were changed to obtain Examples 4 to 8 and 11, and Comparative Examples 2 to 4. Magnetic metal flakes were made.

Table 1 shows the preparation conditions and the results of analysis of the obtained magnetic metal flakes, together with Examples 1 and 3.
However, in Table 1, the addition amount of the coloring pigment is indicated by parts by weight based on 100 parts by weight of the magnetic metal flakes, and the addition amount of the coloring pigment treating agent is indicated by parts by weight based on 100 parts by weight of the coloring pigment.

[0055]

[Table 1]

(Types of amino compounds) a: N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane b: N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane c: dodecamethylenediamine d: hexamethylenediamine (type of aromatic carboxylic acid) A: benzoic acid B: anthranilic acid (evaluation of adhesion state of pigment) 5: pigment is uniformly and finely adhered to the entire surface of each flake 4: entire surface of each flake Pigment adheres to the flakes but the adhesion state is not uniform 3: Pigment adheres to individual flakes in island form 2: Flake with pigment adhered and flake not adhered 1: Pigment not adhered -Example 9-10 g of primary colored magnetic metal flakes under the conditions of Example 5
In a slurry containing 1.0 g of methyl methacrylate, 1.0 g of trimethylolpropane triacrylate, 1.0 g of butyl acrylate, 1.0 g of divinylbenzene (total of monomers: 4 parts by weight per 100 parts by weight of colored magnetic metal flakes).
0 parts by weight), and while heating and stirring at 80 ° C. in nitrogen, 0.3 g of benzoyl peroxide was added as a polymerization initiator to polymerize the monomer and precipitate on the surface of the colored magnetic metal flake. After the treatment, the slurry is subjected to solid-liquid separation to obtain a solid content of 70%.
% Paste.

This colored magnetic metal flake was opened with an opening of 149.
As a result of wet sieving with a sieve of μm, the sieve residue was 0.1%.
% By weight. The median diameter of the colored magnetic metal flakes by a laser diffraction method was 35 μm, and the average thickness calculated from the hiding power was 1.2 μm.

A crush test was carried out using the colored magnetic metal flakes in the same manner as in Example 1. As a result, the measured value was 80 μm.

-Example 10- 10 g of primary colored magnetic metal flakes under the conditions of Example 7
0.15 g of acrylic acid, 0.15 g of ditrimethylolpropane tetraacrylate, 0.15 g of glycidyl methacrylate, 0.15 g of styrene (total of monomers: 6 parts per 100 parts by weight of colored magnetic metal flakes)
Of azobisisobutyronitrile as a polymerization initiator while heating and stirring at 80 ° C. in nitrogen.
The monomer was polymerized by adding 05 g, and precipitated on the surface of the colored magnetic metal flake. After the treatment, the slurry was subjected to solid-liquid separation to obtain a paste having a solid content of 70%.

This colored magnetic metal flake was opened with an opening of 149.
As a result of wet sieving with a sieve of μm, the sieve residue was 0.1%.
%. The median diameter of the colored magnetic metal flakes measured by a laser diffraction method was 20 μm, and the average thickness calculated by the hiding power was 0.9 μm.

A crush test was carried out using this colored magnetic metal flake in the same manner as in Example 1, and the measured value was 60 μm.

Comparative Example 5- 10 g of primary colored magnetic metal flakes under the conditions of Comparative Example 2
0.2 g of methyl methacrylate, 0.2 g of trimethylolpropane triacrylate, 0.2 g of butyl acrylate, 0.2 g of styrene (total monomer:
8 parts by weight based on 100 parts by weight of the colored magnetic metal flakes), and while heating and stirring at 80 ° C. in nitrogen, 0.05 g of azobisisobutyronitrile was added as a polymerization initiator to polymerize the monomer. Deposited on the surface of the colored magnetic metal flake. After the treatment, the slurry is subjected to solid-liquid separation to obtain a solid content of 70%.
% Paste.

Comparative Example 6 A permalloy flake similar to that used in Example 1 was used for a treatment solution comprising 14.4 g of ferric nitrate, 2.4 g of oxalic acid, 18.3 g of triethanolamine, and 500 g of ion-exchanged water. 6 g was added and the mixture was stirred at 80 ° C. for 15 minutes. Thereafter, 500 g of ion-exchanged water was added, and iron oxide was precipitated on the surface of the permalloy flakes, solid-liquid separated and dried to obtain colored magnetic metal flakes.

The colored magnetic metal flakes are
As a result of performing wet screening with a sieve of μm, the residue of the sieve was 5% by weight. The median diameter of this colored magnetic metal flake by laser diffraction method was 110 μm, and the average thickness calculated from the hiding power was 3 μm.

A crushing test was carried out using the colored magnetic metal flakes in the same manner as in Example 1. As a result, the measured value was 100 μm or more.

(Test 1) Examples 1 to 11 and Comparative Examples 1 to
Using the colored magnetic metal flakes obtained in 6 as pigments,
To 10 parts by weight of the colored magnetic metal flakes, 100 parts by weight of a room-temperature-dried acrylic resin varnish (Acrydic A-165 manufactured by Dainippon Ink and Chemicals, Inc.) was added, and the mixture was dispersed with a homomixer to prepare a paint. The obtained paint was applied on an ABS plate (plate thickness: 2 mm) provided with a circular magnet having a diameter of 20 mm on the back side by air spray to prepare a coated plate.

The chroma, metallic luster and sharpness of the magnetic pattern of the obtained coated plate were evaluated in five levels.

A similar test was carried out on a coating material prepared in the same manner as described above by simply mixing 2 parts by weight and 8 parts by weight of the coloring pigment (phthalocyanine blue) and permalloy flake used in Example 1.

(Test 2) Isopropyl alcohol (I
PA), toluene, methyl ethyl ketone (MEK), and 30 g of each of four kinds of solvents of ethyl acetate were added to Examples 1 to 11,
Each of the colored magnetic metal flakes obtained in Comparative Examples 1 to 0.3 was 0.3
g was dispersed at 3200 RPM for 3 minutes using a homomixer, and the obtained dispersion was allowed to stand for 24 hours. Then, the degree of the removal of the pigment was evaluated by observing the supernatant.

Table 2 shows the results of Tests 1 and 2.

[0071]

[Table 2]

(Evaluation of chroma) 5: Very good 4: Good 3: Normal 2: Poor 1: Not colored (Evaluation of metallic luster) 5: Very good 4: Good 3: Normal 2: Poor 1: No gloss (Evaluation of magnetic pattern) 5: Very clear 4: Clear 3: Normal 2: Slightly unclear 1: Unclear (evaluation of solvent resistance) ○: The supernatant is colorless and transparent △: The supernatant is transparent but lightly colored ×: The supernatant Is opaque or deeply colored

Claims (5)

[Claims] 1. A pigment which is colored by adhering a coloring pigment to at least 90% of the surface of all particles and has a crushing of 90 μm or less (JISK5400,
B) The colored magnetic metal flakes according to (1). 2. The colored magnetic metal flake according to claim 1, having a maximum particle size of 150 μm or less, an average thickness of 0.1 to 5 μm, and a median diameter of 5 to 100 μm. 3. The colored magnetic metal flake according to claim 1, wherein the colored pigment is coated with an amino compound having two amino groups in the molecule and not having a carboxyl group. . 4. The colored magnetic metal flake according to claim 1, wherein the colored pigment is coated with a monobasic aromatic carboxylic acid. 5. The colored magnetic metal flake according to claim 1, wherein the surface is coated with a polymer synthesized from a polymerizable monomer.