JPH07104670A - Magnetic sheet label - Google Patents

Abstract

PURPOSE:To prevent an adhesive from remaining on a subject at the time of peeling a once adhered tacky adhesive label by imparting the adhesive force by multiple magnetization using alternating magnetic fields generated by a ring type magnetic head, etc., to a magnetic layer. CONSTITUTION:A base material is provided with the magnetic layer oriented in a specified direction and the surface on the side opposite to the magnetic layer is formed as a display surface. The magnetic layer has the adhesive force by the multiple magnetization using the alternating magnetic fields generated by the ring type magnetic head 2, etc. Such magnetic sheet label 1 is set in an automatic sticking device having a mechanism, such as ring type magnetic head 2, to apply arbitrary magnetic fields. The alternating magnetic fields are applied to the magnetic layer of the label and the adhesive force by leak magnetic fluxes on the surface of the magnetic layer magnetized by magnetic induction are applied thereto, by which the label is adhered to the subject The ring type magnetic head 2 or demagnetizing means, such as permanent magnet, is acted on the magnetic sheet label 1 once adhered to the subject and the DC magnetic field is applied from the label surface to the magnetic layer of the entire part of the label, by which the magnetic layer is demagnetized and the adhesive force is erased.

Description

Detailed Description of the Invention

[0001]

[Field of Industrial Application] The present invention relates to a magnetic sheet label having an adhesive force by magnetism, which is used by being attached to a part before assembly at a production site such as a factory so as to be identified. Of course, in a store or the like, it may be used by being attached to a product for identifying the product.

[0002]

2. Description of the Related Art Labels that are widely used are adhesive labels that utilize the adhesive force of pressure-sensitive adhesives as a means for adhering the label to an adherend. A typical adhesive label has a printing paper such as high-quality paper as a support, a sheet-like label base material coated with an adhesive on the back surface of the support, and a glassine paper or the like as a support separately from this surface. A release sheet that has been subjected to a release treatment such as silicon processing is manufactured, and both of these sheets are laminated to manufacture an adhesive label base paper. Further, the pressure-sensitive adhesive label base paper is appropriately label-printed on the surface of the high-quality paper, punched into a predetermined label shape, and finished as a label.

[0003]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In such an automatic sticking device for sticky labels, the sticky label causes a peeling failure or the like from the release sheet and does not adhere well to the adherend, or the sticky label that has been once stuck is used. It is the actual situation that the adhesive remains on the adherend when it is peeled off. An object of the present invention is to eliminate the phenomenon that the adhesive remains on the adherend when the adhesive label that has been once adhered is peeled off.

[0004]

A magnetic sheet label according to the present invention comprises a substrate provided with a magnetic layer oriented in a fixed direction,
The surface opposite to the magnetic layer is used as a display surface, and the magnetic layer has an adhesive force due to multipole magnetization using an alternating magnetic field generated by a ring type magnetic head or the like. Further, the magnetic layer may be magnetized in multiple poles immediately before the magnetic sheet label is applied to the article.

Further, the magnetic sheet label may be detached from the article by demagnetizing the magnetic layer by applying a demagnetizing means to the magnetic sheet label which is magnetized in multiple poles.

[0006]

In the constitution of the magnetic sheet label of the present invention, a base material is provided for the purpose of imparting mechanical strength, flexibility, distinctiveness as a label and manufacturing convenience. The substrate used in the present invention is not particularly limited, polyethylene, polypropylene, polystyrene, polyvinyl chloride, vinyl chloride vinyl acetate copolymer,
Plastics such as ethylene vinyl acetate copolymer, polyacrylate, polyester, polyimide, polycarbonate, urea resin, melamine resin, nylon resin, urethane resin, ABS resin, phenol resin, fibrin derivative, stainless steel, iron, copper, aluminum, Inorganic sheets such as ceramics, fine paper, coated paper, paper such as synthetic paper, coating provided on the magnetic layer, laminating, printing,
Examples include single sheets such as coating by electro-deposition, vapor deposition, surface polymerization, impregnation, etc., or laminated films, and composite sheets and films, and those which can be used as an ordinary printing substrate may be appropriately selected. As the magnetic material used for the magnetic layer, various known ferromagnetic materials effective as raw materials for permanent magnets can be used. For example, Fe, Ni, Co, Cr, Mn, and alloys or compounds containing these as the main components are known, and many materials are known due to changes in the components and manufacturing methods. That is, various magnetic materials are manufactured by a manufacturing method such as melting or sintering. For example, γ
Ferrite, Ba ferrite, Co ferrite, Sr ferrite, iron, magnetite, MK steel, Co steel, Cr steel, KS
There are steel, baicalloy, cunife, neodymium, boron, and the like, and powders or sheet-like various shapes of these simple substances or mixtures thereof can be used. The method for forming the magnetic layer is not particularly limited, and the magnetic layer can be formed according to a conventionally known and commonly used technique. For example, coating type molding, melt molding, vapor deposition, sputtering, and other methods are used, but the coating type is preferable because it is suitable for adjusting the thickness of the magnetic layer, the selectivity of the support, and suitable for mass production. When a magnetic layer is provided in the coating type molding method,
As the magnetic material, a magnetic powder having a coercive force of 300 Oersted or more and an average particle diameter of 0.01 to 100 microns is preferable, and for example, γ-Fe ₂ O ₃ or BaO-6Fe ₂ O ₃ is preferable. The amount of application may be such that the magnetic force required to attach the magnetic sheet label to an adherend that is a magnetic substance is obtained. Although it depends on the material and weight of the support, a residual magnetic flux of 0.5 Maxwell or more is preferable. When the coating amount is too large, the coat thickness becomes thick, the flexibility of the magnetic label is impaired, and the handleability as a label deteriorates. Further, when magnetized, the influence of the demagnetizing field due to the thickness coefficient becomes strong, and the self-demagnetization action causes a decrease in the adhesive force. If the coating amount is too small, the magnetic flux density will be low and the adhesive force will be reduced. The method for preparing the coating liquid is water, an organic solvent or the like as a dispersion medium, a ball mill, a sand mill, a stirrer / pulverizer such as an attritor, and the like, together with magnetic powder, carbon black, a dispersant, a binder, a curing agent, and the like. Alternatively, it is prepared by separately dispersing. As the binder used here, starches, cellulose derivatives, gelatin, casein,
Polyvinyl alcohol, styrene / maleic anhydride copolymer emulsion, styrene / acrylic acid copolymer, styrene / butadiene copolymer emulsion, urethane resin, acrylic resin, polyester resin, unsaturated polyester resin, epoxy resin, polyimide resin, polyvinyl Butyral resin, alkyd resin, vinyl chloride resin, vinyl chloride / vinyl acetate copolymer resin and the like are blended in an amount of 5 to 60% by weight, and preferably 10 to 50% by weight, based on the total solid content. The method for forming the coating layer is not particularly limited, and the coating layer can be formed according to a conventionally known and commonly used technique. For example, a coating solution for a magnetic layer on the support, an air knife coater, a knife coater, a blade coater,
Gravure coater, curtain coater, die coater,
Apply with a suitable coating device such as roll coater, reverse roll coater, bar coater, spin coater, etc. and apply a magnetic field with a permanent magnet or solenoid to orient the easy axis of magnetization of the magnetic material horizontally or vertically in the sheet smearing direction. Then, it is heated and dried to obtain a magnetic layer. Generally, the dry weight is 5 to 5000 g / m ^2, preferably 10 to 10.
It is 0 g / m ² . In this way, the magnetic layer is formed, appropriate printing for labels is performed on the surface of the base material, and after imparting distinctiveness as a label, the label shape is punched. The printing method is not particularly limited, and conventionally known letterpress printing, gravure printing, offset printing, etc. may be selected as appropriate. The thus-formed magnetic sheet label gives an alternating signal to a ring-type magnetic head or the like that is in contact with or close to the magnetic layer, and applies a magnetic field having a strength and a direction corresponding to the signal to the magnetic layer. The magnetic layer of the magnetic label is magnetized by magnetic induction, and a minute magnet corresponding to the positive / negative and strength of the signal is produced. The magnetic pole (N pole or S pole) of this micro magnet
Depends on the magnetic force of the magnetic material used, but the magnetic layer surface 1
Magnetization is performed at a density of 2 poles or more and 100 poles or less per mm. More preferably, the magnetization is performed at a density of 2 poles or more and 50 poles or less. The multi-pole magnetization makes it possible to stably obtain the label sticking points by the number of N or S poles. In this way, the magnetic label can be formed into a sheet. If the number of poles is too small, the adhesion points will be too thin and problems will occur with the adhesive strength. Also,
If the amount is too large, the magnetic force becomes weak due to the action of self-demagnetization due to the high density, and the adhesive force to the adherend is lowered. The range of the magnetic pole density described above is based on the magnetic material that is mainly used at present such as Ba ferrite, and if the magnetic material having less self-demagnetizing action is used, the number of poles is increased. It is possible to let In addition, it is considered that the adhesive force can be sufficiently obtained with 2 poles or less per 1 mm as long as it is possible to obtain a strong magnetic force in a trace amount compared with the magnetic materials currently used.

The multi-pole magnetization as described above can be performed at any time such as immediately before attaching the magnetic sheet label to the article or immediately before cutting the sheet into strips. On the other hand, a case where a flexible magnet label such as a rubber magnet is considered will be described below. A typical rubber magnet label uses the characteristics of a Ba-ferrite magnet, which is a flexible magnet and has a large crystal anisotropy constant, and its powder is pulverized to a size of 1 to 3 microns and mixed with natural rubber. A vulcanized material, a softening material, an anti-aging agent, etc. are added and the material is molded by pressing or extrusion. An adhesive force is imparted by pressing and magnetizing a permanent magnet that emits a magnetic field that is stronger than the coercive force and reaches the saturation magnetic flux density against the rubber magnet. The operation of pressing such a permanent magnet against a rubber magnet and magnetizing it becomes a discontinuous operation, and it is very difficult to perform it in the middle of a line for producing a large amount of labels while printing them. Therefore, it is necessary to make it a rubber magnet at the stage of the material of the label. An appropriately printed sheet for a label is attached to the surface of such a rubber magnet to obtain a rubber magnet label. A problem in this case is that it is inconvenient to handle because the adhesive force to the adherend is always present, and there is a drawback that it becomes an obstacle especially when pasting print sheets, packaging products, and packaging. However, as described above, since the magnetic sheet label of the present invention can be magnetized in multiple poles at any time as described above, the adhesive force to the adherend, which is seen in such a rubber magnet, is always constant. It also becomes possible to solve the phenomenon that handling is inconvenient because of the existence.

The present invention is a label comprising a base material and a magnetic layer provided thereon. The surface of the base material is appropriately printed for the label, and the label shape is punched after the label is provided with distinctiveness. . Alternatively, by utilizing the fact that the present label is a magnetic substance, it is possible to perform appropriate printing for the label by punching it into a label shape and then fixing it to a partially magnetized conveyor belt for positioning. The magnetic sheet label thus obtained is set in an automatic sticking device such as a ring type magnetic head having a mechanism for giving an arbitrary magnetic field. An alternating magnetic field is applied to the label magnetic layer, and an adhesive force due to a leakage magnetic flux on the surface of the magnetic layer magnetized by magnetic induction is applied to adhere it to the adherend. In addition, a demagnetizing means such as a ring-type magnetic head or a permanent magnet is applied to the present magnetic sheet label once adhered to the adherend to apply a DC magnetic field from the label surface to the magnetic layer of the entire label to demagnetize it. The adhesive force can be erased, and it can be easily peeled off from the adherend. That is, in the magnetic sheet label of the present invention, the adhesive force can be arbitrarily added and deleted. The DC magnetic field at the time of demagnetization must be stronger than the coercive force of the magnetic sheet label. or,
The speed at which the magnetic field is applied to the entire label may be arbitrary.

[0009]

EXAMPLES Examples of the present invention will be described below, but of course the present invention is not limited thereto. In addition, "parts" and "%" in the examples mean "parts by weight" and "% by weight", respectively, unless otherwise specified. [Example 1] Ba ferrite powder (trade name: MC-127 / manufactured by Toda Kogyo Co., Ltd.) 180 parts Carbon black (trade name: Mitsubishi Carbon Black MA-600 / manufactured by Mitsubishi Kasei Co., Ltd.) 5 parts Dispersant ( Soybean oil refined lecithin / manufactured by Ajinomoto Co., Inc. 3 parts Nitrocellulose (trade name: nitrified cotton RS / manufactured by Daicel Kako Co., Ltd.) 15 parts Urethane resin (trade name: Nipolan N-3022 (35% ethyl acetate solution) / Nippon Polyurethane Co., Ltd. 15 parts Isocyanate (trade name: Coronate L (75% ethyl acetate solution) / Nippon Polyurethane Co., Ltd.) 5 parts Vinyl chloride / vinyl acetate copolymer (trade name: S-REC A / Sekisui Kako Co., Ltd.) 15 parts Methyl ethyl ketone 100 parts Toluene 100 parts The above composition was mixed and dispersed using a ball mill to prepare a magnetic coating material. This is smeared on one surface of a white polyethylene terephthalate film having a thickness of 188 μm, which is a base material, by a gravure coating method, and a magnetic field is applied so as to orient the easy axis of magnetization of the magnetic particles in the horizontal direction of the main surface of the coating layer for dry coating. Then, a magnetic coating layer having a saturation magnetic flux of 1.0 Maxwell and a squareness ratio of 88% was formed. On the opposite side of the magnetic coating layer of this base material, offset printing is applied to the base material so as to give a distinctiveness as a label, and the base material is punched into a predetermined label shape.

The state of magnetizing the label thus obtained is shown in FIG. FIG. 1 is a principle view showing a situation where a magnetic sheet label is magnetized in multiple poles by a ring type magnetic head. This magnetic sheet label 1 is 300 in the orientation direction.
An alternating current of 1 kHz is applied to the fixed ring-type magnetic head 2 which is run at a speed of mm / S and is in contact with the magnetic layer, and a magnetic field having a strength and an orientation corresponding to this current is generated to form the minute magnets 3, 3 in the magnetic layer. I made ──. The density of the N pole and the S pole of the micro magnet thus formed is 7 poles per mm. [Embodiment 2] FIG. 2 shows a state in which a magnetic sheet label having micro magnets formed in the same manner as in Embodiment 1 is demagnetized. FIG. 2 is a principle diagram showing a situation where the magnetic sheet label 1 is demagnetized by the ring type magnetic head 2. With the ring-shaped magnetic head 2 in contact with the surface of the base material, the ring-shaped magnetic head 2 in which a direct current was applied was set to 300 mm / in the orientation direction.
The micro magnets 3 formed by running at S were demagnetized by the demagnetizing field. This state is schematically shown in FIG. [Comparative Example 1] A magnetic sheet label before the formation of the minute magnets produced in the same manner as in Example 1 was processed to 300 mm in the orientation direction.
/ S, and an alternating current of 150 Hz was passed through the ring type magnetic head to magnetize one pole per 1 mm. The other conditions were the same as in Example 1. [Evaluation] With respect to the samples obtained in the respective examples and comparative examples described above, the adhesive force between the magnetic sheet label and the magnetic substance such as iron is examined in order to evaluate the adhesive force. Specifically, a strip-shaped sheet label is attached to the horizontal surface of the iron plate. afterwards,
When the thread attached to the surface of the sheet label is hooked on the tip of the spring balance and pulled in the vertical direction, when the sheet label comes off,
The force is read and the value is divided by the surface area of the label. The results are shown in Table 1.

[0011]

[Table 1]

[Evaluation Result] From the comparison between Example 1 and Comparative Example 1, the relationship between the magnetic pole density and its adhesion can be understood. That is, 1m
In the case of Comparative Example 1 in which there is only one attachment point per m, it is considered that the label itself cannot support the label due to its low adhesion. Further, from Example 2, it is considered that the label, which has once obtained the adhesive force by the micro magnets formed by multi-pole magnetization, is demagnetized by the DC magnetic field to disappear the micro magnets and lose the adhesive force. Of course, it was confirmed that when the label was peeled off from the adherend by demagnetization as in Example 2, no scratch or trace was left on the surface of the adherend.

[0013]

The magnetic sheet label obtained by the present invention is
When peeling off a pressure-sensitive adhesive label that has been adhered once as seen with a pressure-sensitive adhesive label, no trace of an adhesive or the like remains on the adherend.

[Brief description of drawings]

FIG. 1 is a principle view showing a situation in which a magnetic sheet label is multipolarly magnetized by a ring type magnetic head.

FIG. 2 is a principle view showing a situation in which a magnetic sheet label is demagnetized by a ring type magnetic head.

[Explanation of symbols]

 1 Magnetic sheet label 2 Ring type magnetic head

Claims (3)

[Claims] 1. A multipole using a magnetic layer oriented in a certain direction on a base material, the surface opposite to the magnetic layer serving as a display surface, the magnetic layer using an alternating magnetic field generated by a ring type magnetic head or the like. A magnetic sheet label having an adhesive force due to magnetization. 2. The magnetic layer is magnetized in multiple poles immediately before the magnetic sheet label is applied to an article.
The magnetic sheet label described. 3. The magnetic sheet label according to claim 1, wherein the magnetic sheet label is attached to and detached from the article by demagnetizing the magnetic layer to demagnetize the magnetic layer. .