JPH09157556A - Magnetic ink and magnetic thermosensitive transfer material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a magnetic ink which does not lose the intrinsic magnetic characteristics of the constituent amorphous ferromagnetic, can dispense with aftertreatment such as orientation and can be used in a manner similar to that in which a common ink is used and to obtain a magnetic thermosensible transfer material capable of being subjected to arbitrary printing with e.g. a printer. SOLUTION: A magnetic ink containing a ferromagnetic powder 3 prepared by grinding a vapor-grown thin film (e.g. vapor-deposited film) and therefore having intrinsic magnetic properties is provided. A magnetic thermosensible transfer material prepared by adjusting the properties of the magnetic ink so that it may be transferred to a substrate 1 under the influence of heat and pressure and coating either surface of a base film with it is also provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink and a printer for magnetic printing, and a thermal transfer material for hot stamping.

[0002]

2. Description of the Related Art Conventionally, magnetic ink is used for printing such as securities for the purpose of security, and magnetic ink printing characters are used for the purpose of reading characters (JIS C-
6251). In the case of magnetic ink printed characters, when the JIS standard is taken as an example, the magnetically printed characters are saturated and magnetized by a DC magnetizing head, read by a magnetic reading head having a specified gap width, and the character pattern is determined by the output voltage.
As an application example using magnetic ink, a barcode is printed with magnetic ink and read with a magnetic head. A general barcode uses the reflection of light,
It is vulnerable to stains and may cause cosmetic problems from an aesthetic point of view. In this respect, the bar code using the magnetic ink has an advantage that stains on the appearance hardly pose a problem.

[0003]

Currently, the main purposes of using magnetic ink for printing are security and stain resistance. However, almost all magnetic inks are magnetic powders containing iron oxide as a main component mixed with a binder such as a resin. Since raw materials are easily available, they have the drawback of lacking security. On the other hand, a ferromagnetic material having unique magnetic properties can be used as a security material [see Japanese Patent Application No. 7-197100, "Authentication / Determination Device for Safety Paper"]. In this prior application example, the characteristics of the amorphous magnetic film formed on the resin substrate by vapor deposition etc. are used as the ferromagnetic material, and the resin substrate is included in the shape of a tag (safety line) and is cut into paper or the like. It is used by pasting it on the surface of a class. Furthermore, it has been reported that amorphous ferromagnetic materials lose their inherent magnetic properties when made into powder ["Sensor Technology", Vol. No. 1, January 1987], and even if magnetic powder is used, the intrinsic magnetic properties are lost. Even if you try to obtain [Japanese Patent Application 6
119965 "Presence determination system with magnetic detection marker"], it is reported that the thickness of the magnetic layer is preferably 10 to 20 μm, the width is 10 to 30 mm, and the length is 10 to 50 mm. 20 μm after coating with a diameter of 15 μm
Alignment treatment is required with a magnetic field of 00 Gauss or more, which has a drawback in that it is practically limited.

An object of the present invention is to provide a magnetic ink that can be used like a general printing ink without losing the inherent magnetic properties of the amorphous ferromagnetic material and without the need for post-treatment such as orientation. is there. Another object of the present invention is to provide a magnetic heat-sensitive transfer material capable of arbitrary magnetic printing with a printer or the like.

[0005]

In order to achieve this object, the magnetic ink according to the present invention contains a ferromagnetic powder obtained by pulverizing a vapor-deposited thin film such as a vapor-deposited film so as to have a unique magnetic property. It has a held structure. Furthermore, the magnetic heat-sensitive transfer material according to the present invention is a magnetic ink containing a ferromagnetic powder obtained by pulverizing a vapor-grown thin film such as a vapor-deposited film to retain its inherent magnetic characteristics, and the magnetic ink is subjected to heat and pressure. It is adjusted so that it is transferred onto the surface of the base film and is applied onto one surface of the base film.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to facilitate understanding of the embodiments of the present invention, items such as actions will be described. A characteristic of an amorphous ferromagnet is a rapid reversal of magnetic flux (large Barkhausen phenomenon). This is because the domain walls that form the magnetic domains move instantaneously. That is, it is known that in order for this phenomenon to occur, a certain amount of magnetic material that constitutes a magnetic domain is required, and this phenomenon disappears in the case of an ordinary powdery material. If it is possible to print on an object to be printed while maintaining a certain amount of magnetic domain structure,
This unique magnetic property can be detected from printed characters or patterns such as barcodes. number~
In order to print a magnetic film having a thin film thickness of several tens of μm, it is generally necessary for the magnetic material used as the frit of the ink to have a particle size of about 3 μm or less. If a bulk or powder that is an amorphous ferromagnetic material is crushed to obtain a fine powder having a particle size of about 3 μm or less, or if a fine powder having a particle size of about 3 μm or less is directly obtained, the magnetic characteristics originally possessed change. .
That is, it is known that the coercive force, the maximum magnetic flux density, the squareness ratio, and the magnetic permeability are deteriorated. However, the magnetic powder produced by crushing a film whose film thickness is controlled by vapor phase growth method such as vapor deposition, sputtering, and CVD as a starting material maintains the structure in the film thickness direction even after crushing. Unique magnetic characteristics can be detected with the magnetic domain structure unchanged.
At this time, the minimum film thickness is determined by the composition of the magnetic material, film forming conditions, etc., and is a very thin magnetic film of about 500 to 5000 Å (0.05 to 0.5 μm). A magnetic printing film of several to several tens of μm can be obtained by adjusting only the size in the direction to a predetermined size.

The amorphous ferromagnetic film formed from such magnetic ink or magnetic heat-sensitive transfer material can provide a magnetic film having high security while maintaining its properties. In addition to the magnetic powder of 10 to 90%, the binder of the ink and the thermal transfer material is 10 to 90% of a thermoplastic resin such as polyethylene / polypropylene / acryl / ethylene vinyl acetate copolymer as a binder and carnauba as a wax. 0 to 20% of natural wax such as wax or synthetic wax such as ester wax, 0 to 20% of dibutyl phthalate / dioctyl phthalate and the like as a plasticizer, 0 to 3% of a surfactant and the like as a dispersant, and If necessary, the pigment may be contained in an amount of 0 to 80%. In the case of ink, these components are dissolved / dispersed in an appropriate organic solvent such as toluene, and in the case of a heat-sensitive transfer material, these are dissolved / dispersed in an organic solvent, applied on a base film and dried to form a heat-sensitive transfer material. And At this time, each component is selected and mixed in accordance with the purpose of the ink or the thermal transfer material, but in the present invention, any composition may be adjusted as long as it contains the magnetic powder. The magnetic ink can be applied to any printing method, such as screen printing, letterpress printing, intaglio printing, offset printing, etc., if the viscosity and the like are adjusted according to the application. What kind of transfer method can be used for magnetic thermal transfer materials if the transfer characteristics are adjusted according to the application, such as thermal transfer ribbons used in word processors or hot stamping ribbons used for the purposes of decoration, character printing, and security? Can also respond.

[0008]

EXAMPLE FIG. 1 shows an example of printing using the magnetic ink according to the present invention. FIG. 1 is an enlarged schematic view of a coating film printed with a magnetic ink or a magnetic thermal transfer material according to the present invention. Reference numeral 1 denotes a printing object to be printed, which may be metal, leather, ceramic, cloth, plastic, or the like as long as the ink adheres thereto. 2 is a binder, which is a thermoplastic resin
It is composed of wax, plasticizer, dispersant, etc., and is surrounded by magnetic powder in a matrix. 3 is a ferromagnetic powder,
Thickness based on Co, Fe, Ni as a main component 0.05-0.5μ
m is a phosphorus-like amorphous ferromagnetic powder.

FIG. 2 is an example of a printed pattern,
The bar code shown in (a) and the letters, numbers, etc. shown in (b) can be printed to read the signal corresponding to the pattern.

FIG. 3 shows the principle of printing when a magnetic thermal transfer material is used, and printing is performed in the same manner as the printing method using the thermal head of a general thermal printer. The base film 5 is passed through the thermal head 4 to melt the thermoplastic resin.
The ink containing the ferromagnetic powder 3 is softened and adheres to the substrate 1. A part of the magnetic heat-sensitive transfer material is transferred to the printing target 1 by the pressure and adhesive force of the heat-sensitive head 4.

FIG. 4 shows an example of the data of the magnetic printed matter and a detection circuit for security. Here, 10 is a magnetic ink deposited on one surface of the substrate 1,
Reference numeral 1 is an excitation power source, 12 is an excitation coil, 13 is a sense coil, 14 is an amplifier, and 15 is a signal processing circuit. To detect the peculiar characteristic of the amorphous ferromagnetic material, for example, there is a method of utilizing the generation of a harmonic signal by utilizing the large Barkhausen effect. The exciting coil 12 excites the magnetic ink 10 as the ferromagnetic film. An analog or digital filter that detects a change in magnetic flux emitted from the magnetic ink 10 serving as a magnetic film by a sense coil 13 arranged in the vicinity and amplifies the detected signal by an amplifier 14 and then detects the magnitude of a harmonic component. With the signal processing circuit 15 including, it is possible to detect the presence of the magnetic ink 10 as the ferromagnetic film and extract the detection signal.

FIG. 5 is a diagram showing an example of the detection signal, which is a detection signal detected by the circuit of FIG. 4, for example, what is printed in the form of a bar code, and a portion where the magnetic ink 10 exists as a ferromagnetic material. There is an excitation signal containing a harmonic wave, and by moving the excitation coil 12 and the sense coil 13 or the object to be printed 1, a printing state can be obtained as a time-series signal. Excitation coil 12 and sense coil 13 are magnetic ink 1
Since it is not necessary to contact the ferromagnetic material formed from 0 and it can be made non-contact within the range allowed by the data reading resolution, it is possible to print on the back side of paper, for example, or to cover the printed matter. .

[0013]

As described in detail above, according to the present invention, it is possible to impart the unique magnetic characteristics of an amorphous ferromagnetic material to a pattern printed in a usage pattern such as an ordinary printing ink. There is an effect that various processes using the pattern can be efficiently executed with high security. Also, when used as a magnetic heat transfer material, there are no special usage restrictions,
Widely applicable.

[Brief description of the drawings]

FIG. 1 is a perspective view for explaining a specific example of printing with magnetic ink according to the present invention.

FIG. 2 is a perspective view showing an example of a printed matter using the magnetic ink or the heat-sensitive transfer material of the present invention.

FIG. 3 is a side view for explaining a transfer principle using the heat-sensitive transfer material according to the present invention.

FIG. 4 is a circuit system diagram showing an example of a detection circuit for detecting information from a printed material using the magnetic ink or the thermal transfer material according to the present invention.

5 is a diagram for explaining an example of a detection signal from the detection circuit of FIG.

[Explanation of symbols]

 1 Printed Material 2 Binder 3 Ferromagnetic Powder 4 Thermal Head 5 Base Film 10 Magnetic Ink 11 Excitation Power Supply 12 Excitation Coil 13 Sense Coil 14 Amplifier 15 Signal Processing Circuit

Claims (6)

[Claims] 1. A magnetic ink containing a ferromagnetic powder obtained by pulverizing a vapor-deposited thin film such as a vapor-deposited film to retain its inherent magnetic properties. 2. The coloring material is contained so as to give the magnetic ink a desired color.
The magnetic ink described in 1. 3. The magnetic ink according to claim 1, wherein the magnetic ink contains a non-magnetic conductor metal powder. 4. A magnetic ink containing a ferromagnetic powder obtained by pulverizing a vapor-grown thin film such as a vapor-deposited film so as to retain its inherent magnetic properties, is adjusted so as to be transferred to a printing medium by heat and pressure. The magnetic heat-sensitive transfer material coated on one surface of the base film. 5. The magnetic heat-sensitive transfer material according to claim 4, wherein the magnetic heat-sensitive transfer material contains a colored material so as to have a desired color. 6. The magnetic thermosensitive transfer material according to claim 4, wherein the magnetic thermosensitive transfer material contains a non-magnetic metal powder.