JP2002329608A - Magnetic attraction sheet, its manufacturing method and device, and its magnetizing method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic attraction sheet which has a low diamagnetic field, is hardly demagnetized by it, can be formed into a thin film, and manufactured at a low cost, a method and a device for manufacturing the same, and a method and a device for magnetizing the same. SOLUTION: A magnetic attraction sheet 1 is equipped with a magnetic layer 6, and the magnetic layer 6 is provided with an axis of easy magnetization in its plane and magnetized so as to be multipolar. A method of manufacturing the magnetic attraction sheet 1 by magnetizing a magnetized material 10 equipped with at least a magnetic layer 6 comprises a first process of orienting the axis of easy magnetization of the magnetic layer 6 in its in-plane direction and a second process of magnetizing the magnetic layer so as to be multipolar in its in-plane direction by arranging magnets 9 or 11 that have magnetic poles alternately on the magnetic layer 6 of the magnetized material 10, and a device for manufacturing the magnetic attraction sheet 1 is provided. When the magnetized material 10, which is equipped with the magnetic layer 6 where an axis of easy magnetization is oriented in its in-plane direction and used for the formation of the magnetic attraction sheet 1, is magnetized, the magnets 9 or 11 having alternately magnetic poles are arranged on the magnetic layer 6 of the magnetized material 10, so that the magnetic layer 6 is magnetized so as to be multipolar in its in-plane direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a magnetic attraction sheet,
The present invention relates to a manufacturing method and a manufacturing apparatus thereof, and a magnetizing method and a magnetizing apparatus.

[0002]

2. Description of the Related Art Magnetic attraction sheets utilizing magnetic attraction of magnets are widely used as various display devices, and their use is particularly expanding as office supplies.

[0003] In recent years, with the rapid spread of personal computers, the performance of peripheral devices such as printers has been remarkably improved, and the quality of printing by general-purpose printers is becoming comparable to the quality of printing by business-use printers. At the same time, there is a growing desire to freely use those printed materials.

[0004] The primary use of printed matter is for display. Various fixing materials such as various adhesives, adhesive tapes, pushpins, cap magnets, and the like are used to fix a display object at a posting place. Since the magnetically attractable sheet is a fixing material having a magnetic attraction itself, when the posting place is a ferromagnetic surface, it does not need another fixing material, and can be attracted and fixed to the posting place by itself. it can. Also, it can be freely attached and detached from the posting place.

[0005] The magnetic attraction sheet is a sheet-like bonded magnet, and as its use is expanded, its thickness is being reduced to facilitate processing. In recent years, a magnetic attraction sheet manufactured by extrusion and having a magnetic layer thickness of 0.1 mm and an overall magnetic attraction sheet thickness of 0.2 mm has been put to practical use.

FIGS. 8 and 9 show a conventional magnetic attraction sheet 1.
4 is a schematic cross-sectional view of FIG. 4 and an example of a manufacturing method thereof. As shown in FIG. 8, in the conventional magnetic attraction sheet 14, the magnetic powder is oriented so as to have an easy axis of magnetization in the direction perpendicular to the plane of the magnetic layer, and is magnetized so as to be polarized in the direction perpendicular to the magnetic layer. I have. The manufacturing method is, as shown in FIG.
A pair of magnets 15 whose poles are alternately magnetized are arranged close to each other so that different poles face each other, and a sheet 14 having an easy axis of magnetization in the vertical direction is passed through a gap between the magnets. , And can be polarized so as to be polarized in the vertical direction.

[0007]

A magnet produces a magnetic field outside the magnet by means of an N pole and an S pole, and generates a magnetic field by the same magnetic pole inside the magnet. This is called a demagnetizing field.
Since the demagnetizing field faces the magnetic circuit created by the external magnetic field, it acts in a direction to weaken the magnetization of the magnet itself. And
In the same manner as the magnetic field becomes stronger as the distance between the N and S poles becomes shorter, the demagnetizing field also becomes larger as the distance between the N and S poles becomes shorter, that is, the N
The smaller the −S pole, the stronger the magnet becomes, and the magnet tends to be demagnetized. As shown in FIG. 8, the distance 4 'between the magnetic poles of the conventional magnetic attraction sheet 14 oriented and magnetized in the direction perpendicular to the magnetic layer surface is equal to the thickness of the magnetic layer. To reduce the demagnetizing field, the thickness of the magnetic layer must be increased. Further, if the thickness of the magnetic layer is reduced in order to improve the easiness of processing the magnetic attraction sheet 14, as described above, the distance 4 'between the magnetic poles of the conventional magnetic attraction sheet 14 is equal to the thickness of the magnetic layer. Therefore, the distance 4 'between the magnetic poles becomes closer, and accordingly, the demagnetizing field becomes larger, and the magnetic field is easily demagnetized.

Further, the production of a magnetic attraction sheet by a plastic molding method requires a large-scale facility because a paste in which a powdery magnetic material and a binder are kneaded is processed under high temperature and high pressure. Furthermore, the plastic molding method becomes more difficult as the film becomes thinner, and the load on the equipment increases.

Further, since the magnetization of the magnet requires a strong magnetic field, a strong magnetic field generator must be installed, and a large amount of driving is required to drive the strong magnetic field generator and other equipment. Consumes power. Further, such equipment and energy used greatly increase the manufacturing cost of the magnetic attraction sheet.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to reduce the demagnetizing field, thereby making it difficult to demagnetize, and enabling thinning.
Another object of the present invention is to provide a magnetic attraction sheet, a manufacturing method and a manufacturing apparatus thereof, and a magnetizing method and a magnetizing apparatus thereof, which have low manufacturing costs.

[0011]

That is, the present invention comprises a magnetic layer, wherein the magnetic layer has an easy axis of magnetization in an in-plane direction, and is multipolar magnetized in the in-plane direction. And a magnetic attraction sheet.

In producing a magnetically attractable sheet by magnetizing a magnetized body provided with at least a magnetic layer, a step of orienting an axis of easy magnetization in an in-plane direction with respect to the magnetic layer; And a step of multi-polarizing the magnetic layer in the in-plane direction by using the magnet, and a method of manufacturing a magnetically attractable sheet, the method comprising: An apparatus for manufacturing a magnetically attractable sheet by magnetizing a magnetized body having at least a magnetic layer for realizing a manufacturing method, wherein an easy axis of magnetization is oriented in an in-plane direction with respect to the magnetic layer. Orientation means, magnets having magnetic poles alternately arranged on at least the magnetic layer surface side of the magnetized body, and magnetizing means for multipolar magnetizing the magnetic layer in the in-plane direction by the magnet. Magnetic adsorption sheet Those of the manufacturing apparatus.

[0013] Further, when a magnetized sheet for a magnetic attraction sheet having a magnetic layer in which the axis of easy magnetization is oriented in the in-plane direction is subjected to a magnetizing treatment, magnets having magnetic poles are alternately formed by at least one of the magnetized sheets. A magnetizing method for a magnetic attraction sheet, which is disposed on the magnetic layer surface side and magnetizes the magnetic layer in the in-plane direction by the magnet, and in-plane magnetization for realizing the magnetizing method. An apparatus for magnetizing a magnetic body for a magnetic attraction sheet having a magnetic layer in which an easy axis is oriented, wherein magnets having magnetic poles are arranged at least on the magnetic layer surface side of the magnetic body. Further, the present invention relates to a magnetizing device for a magnetic attraction sheet, comprising a magnetizing means for magnetizing the magnetic layer in the in-plane direction with this magnet.

According to the present invention, the magnetic layer has an easy axis of magnetization in the in-plane direction and is multipolar magnetized in the in-plane direction. The distance between the magnetic poles can be formed at a desired distance regardless of the thickness of the magnetic layer, even if the thickness of the magnetic layer is reduced. Further, as the thickness of the magnetic layer is smaller, the distance between the magnetic poles is relatively smaller, and the demagnetizing field is smaller. Therefore, even if the thickness of the magnetic layer is small, the distance between the magnetic poles can be sufficiently secured, so that the demagnetizing field does not increase and demagnetization is difficult. Further, since a magnetic field can be generated in a direction to increase the magnetic force, the magnetic force is excellent.

The magnet having an easy axis of magnetization in an in-plane direction with respect to the magnetic layer by an orientation means for orienting the axis of easy magnetization in an in-plane direction with respect to the magnetic layer and having magnetic poles alternately Is disposed at least on the magnetic layer surface side of the magnetized body, and the magnetic layer is multipolarly magnetized in the in-plane direction by this magnet. Therefore, it is necessary to install a strong magnetic field generator or the like as in the related art. However, since the equipment does not become large-scale, energy consumption can be reduced and manufacturing cost can be reduced.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described more specifically based on embodiments.

FIG. 1 is a schematic sectional view of a magnetic attraction sheet according to the present invention.

The magnetic attraction sheet 1 according to the present invention comprises the magnetic layer, wherein the magnetic layer has an easy axis of magnetization in the in-plane direction, and the polarization direction is alternately reversed in the in-plane direction. It is preferable that the magnets are multipolar magnetized as described above.

The magnetic coating film in which the easy axis is oriented in the in-plane direction with respect to the magnetic layer is (NS) (SN) (NS) .multidot. In the direction of the easy axis. By performing multipolar magnetization as in the above, a maximum leakage flux in the vertical direction can be generated from the opposed magnetic pole surface of SS or NN to the magnetic layer, The magnetic attraction force can be effectively exerted between the adsorbent 2 and a ferromagnetic wall surface such as steel. Further, as shown by the lines of magnetic force, a magnetic field can be generated in a direction in which the magnetic force is increased, so that the magnetic force is excellent.

As shown in FIG. 8, in the conventional magnetic attraction sheet, since the distance 4 'between the magnetic poles of the unit magnet 3' is equal to the film thickness, the maximum value of the magnetic force does not change even if the unit width of the unit magnet 3 'changes. On the other hand, as shown in FIG. 1, the magnetic attraction sheet 1 according to the present invention has a larger width of the unit magnet 3 as shown in FIG.
The distance 4 between the magnetic poles becomes longer, and the maximum value of the magnetic force can be increased.

Further, since the distance 4 between the magnetic poles does not depend on the thickness of the magnetic layer, even if the thickness of the magnetic layer is reduced, the distance 4 between the magnetic poles can be sufficiently secured and the demagnetizing field increases. No, it is hard to demagnetize. Further, at the time of magnetic attraction to the to-be-adsorbed body 2, the to-be-adsorbed body 2 becomes a yoke, the magnetic circuit is almost completely closed, and leakage magnetic flux can be minimized.

FIG. 2A is a schematic sectional view of the magnetic attraction sheet 1 according to the present invention. As shown in FIG. 2, a magnetic layer 6 mainly composed of a magnetic powder and a binder is formed on a nonmagnetic support 5. ,
Preferably, the easy axis is oriented so that the in-plane squareness ratio with respect to the magnetic layer 6 is 80% or more,
Further, it is preferable that the non-magnetic support 5 has a print receiving layer 7 on the surface of the non-magnetic support 5 where the magnetic layer 6 is not provided.
Here, when the easy axis is oriented at a squareness ratio of less than 80% in the in-plane direction with respect to the magnetic layer 6, a predetermined attraction force may not be obtained when magnetizing.

The magnetic recording medium further includes a magnetic layer 6 having an easy axis of magnetization in the in-plane direction and multipolarly magnetized in the in-plane direction, and is provided on the print receiving layer 7 by a copying machine, a printer, or the like. Printing may be performed, and as shown in FIG. 2B, the magnetic attraction sheet 1 according to the present invention is magnetically attracted to, for example, an iron bulletin board 8, and can be used as various display devices.

In producing a magnetically attractable sheet by magnetizing the magnetized body having at least the magnetic layer,
A pair of magnets having N poles and S poles alternately magnetized are arranged close to each other on the surface of the magnetized body on which the magnetic layer is provided and on the surface opposite thereto so that the same poles are opposed to each other. And this one
Preferably, the magnetic layer is multipolarly magnetized by a pair of magnets such that the polarization direction is alternately reversed in the in-plane direction.

FIGS. 3 and 4 show schematic sectional views of a manufacturing apparatus or a magnetizing apparatus according to the present invention.
A pair of cylindrical permanent magnets 9 in which the poles and the S poles are alternately radially magnetized are placed on the surface of the magnetized body 10 on the side having the magnetic layer 6 and on the opposite side so that the poles face each other. It is preferable to arrange the magnetized members 10 close to each other with the magnetized body 10 interposed therebetween, and to perform synchronous rotation along the easy axis with the same pole always facing up and down.

Since this apparatus can perform magnetization along the direction of the easy axis of magnetization of the magnetic body 10, for example, it is wound once after the orientation step of the magnetic body 10, and continuously wound in the roll form. It can be magnetized.

As shown in FIG. 5, a pair of prism-shaped permanent magnets 11 having N poles and S poles alternately multipole magnetized in the longitudinal direction have a magnetic layer 6 of the magnetized body 10. On the surface side and the opposite surface side, the magnetized body 10 is disposed close to and sandwiched such that the same poles are opposed to each other, and the magnetized body 10 is moved in a direction perpendicular to the easy axis of magnetization. It is also possible to manufacture the magnetically attractable sheet based on the above-mentioned magnetizing treatment.

Regardless of which apparatus is used, the magnetized body 10 for a magnetic attraction sheet according to the present invention, which includes the magnetic layer 6 with the easy axis of magnetization oriented in the in-plane direction, is subjected to the magnetizing treatment. At this time, the N pole and the S pole are alternately magnetized.
A pair of permanent magnets 9 or 11 are disposed close to each other on the surface of the magnetized body 10 on which the magnetic layer 6 is provided and on the surface opposite thereto so that the same poles are opposed to each other. 11, the magnetic layer 6 can be multipolarly magnetized so that the polarization direction is alternately reversed in the in-plane direction. Therefore, it is not necessary to install a strong magnetic field generator or the like that consumes power as in the related art. In addition, since the equipment does not become large-scale, energy consumption can be further reduced, and manufacturing cost can be suppressed.

Further, for example, the rare earth permanent magnet can be used as a source of a magnetic field required for performing the magnetizing process. By using this magnetic field, energy for magnetizing can be reduced. Since there is no need to take in the magnet from the outside and the magnetizing can be performed semi-permanently, the cost can be effectively reduced in manufacturing the magnetic attraction sheet according to the present invention.

The time for performing the magnetization treatment is not particularly limited. For example, the magnetization may be performed immediately after the magnetic layer is formed and the easy axis orientation step is performed. After the step, the magnetic layer may be wound once, and may be performed after the magnetized body is cut into a predetermined size.Furthermore, a print receiving layer is formed on the magnetic layer, and the easy magnetization axis orientation step is performed. Thereafter, once wound, the magnetized body is cut into a predetermined size, on the print receiving layer, the magnetizing treatment may be performed at the same time that printing is performed, in addition to these, the A print receiving layer was formed on the magnetic layer, and after the step of orienting the easy axis, the film was wound once, the magnetized body was cut into a predetermined size, and printing was performed on the print receiving layer. After or before, the magnetizing process may be performed.

As described above, on the non-magnetic support,
On the side opposite to the side having the magnetic layer, the print receiving layer capable of performing various printings can be provided, and the print receiving layer includes a heat-sensitive layer, a thermal transfer ink receiving layer, an ink jet receiving layer, a bubble jet (registered). (Trademark) receiving layer, dot impact receiving layer, laser printer toner receiving layer, etc., it is possible to form functional layers according to various printing methods, and appropriately select the print receiving layer according to the display purpose and printing method. it can.

The thickness of the non-magnetic support is 0.05 to 0.5.
When the magnetically attractable sheet according to the present invention has the print receiving layer, the thickness of the nonmagnetic support including the print receiving layer is preferably 0.05 mm.
It is preferably from 5 to 0.15 mm. When the thickness of the non-magnetic support is less than 0.05 mm, the print receiving layer is printed, and when used for display purposes, the color of the magnetic layer is transparent to the surface of the non-magnetic support. The display appearance may deteriorate.

The thickness of the magnetic layer is 0.03 to 0.1 mm
Is preferable. Since the magnetic energy of the magnet is proportional to the volume of the magnet, the thickness of the magnetic layer is 0.03 m.
m, the weight of the magnetic layer + the nonmagnetic support is
In some cases, it is not possible to obtain a magnetic attraction force sufficient to stably fix the device to the vertical surface to be attracted. When the thickness of the magnetic layer exceeds 0.1 mm, the magnetic attraction force is sufficient,
During long-term use, repeated deformation of the sheet during attachment / detachment tends to cause coating film destruction due to mechanical fatigue.

The total thickness of the magnetic attraction sheet according to the present invention is preferably 0.08 to 0.25 mm, and the total thickness of the magnetic attraction sheet including the magnetic layer according to the present invention exceeds 0.25 mm. In such a case, it falls outside the range that can be handled by a general home printing press.

In the magnetic attraction sheet according to the present invention, since the distance between the magnetic poles does not depend on the thickness of the magnetic layer, the distance between the magnetic poles can be sufficiently secured even if the thickness of the magnetic layer is reduced. The demagnetizing field does not increase and is hard to demagnetize. Therefore, as described above, the thickness of the magnetic layer is 0.05 to
It is 0.15 mm and the total thickness is 0.08 to 0.25 mm, and it is possible to realize the same thinness as ordinary printing paper.

The coercive force of the magnetic powder is 700-4000O
e is preferable, for example, Ba ferrite powder, S
Ferromagnetic iron oxide powder such as r ferrite powder can be used.

The magnetization of the magnetic material usually requires a magnetic field several times or more that of the target magnetic material, but the coercive force of the ferromagnetic iron oxide is usually 4000 Oe or less. When used in the invention, the magnet can be sufficiently magnetized by the magnetic field of a rare earth permanent magnet as described below.

The cylindrical and prismatic permanent magnets preferably used in the present invention include, for example, Sm-C
Rare earth permanent magnets such as o magnets, Sm-Fe-N magnets, and Nd-Fe-B magnets can be used. In order to magnetize a magnetic body, it is usually necessary to expose the target substance to a magnetic field of its coercive force or more.However, to perform the magnetizing treatment on the magnetized body containing the ferromagnetic iron oxide, The magnetic field can be sufficiently magnetized by a magnetic field that is at least twice the coercive force of the ferromagnetic iron oxide. Since the coercive force of the ferromagnetic iron oxide is usually 4000 Oe or less, the permanent magnet can be magnetized if there is a permanent magnet capable of generating a magnetic field of twice or more, that is, 8000 Oe or more. Further, when the coercive force of the ferromagnetic iron oxide is 3000 Oe or less,
A permanent magnet that can generate a magnetic field that is twice as large as this, that is, 6000 Oe or more is sufficient to magnetize the magnetic body.

In the case of a ferrite permanent magnet, since the saturation magnetic flux density is 4000 Gauss or less, the maximum value of the generated magnetic field does not exceed the saturation magnetic flux density even if a magnet having a strong magnetic field is used. When processing, 60
When a magnetic field of 00 to 8000 Oe or more is required,
Not very suitable. The rare earth permanent magnet is usually
Since it has a saturation magnetic flux density of 8000 to 15000 Gauss or more, it can be particularly preferably used. Also,
By using the magnetic field of the permanent magnet such as the rare earth, it is not necessary to particularly take in the energy for the magnetizing process from the outside, and the magnetizing process can be performed semi-permanently. In manufacturing the suction sheet, the cost can be reduced more effectively.

As the binder, thermoplastic and thermosetting resins can be suitably used. For example, polyvinyl chloride, polyvinyl chloride, epoxy resin, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate block copolymer can be used. Organic polymers such as polymers, ethylene- (meth) acrylate copolymers, or block copolymers polyethylene, acrylic resins, polyester resins, and polyurethane resins are exemplified. These may be used alone or in combination of several kinds of resins.

As a method of forming the magnetic layer on the non-magnetic support, a kneaded product of the ferromagnetic powder and the binder is formed into a sheet by extrusion molding, compression molding, or the like, and then is formed into a sheet. A magnetic paint obtained by dispersing the ferromagnetic powder in a binder and a solvent by a method of laminating on a magnetic support, or by applying a gravure coater, a die coater, a knife coater or the like on the non-magnetic support. And a method in which a solvent in the paint is evaporated by a hot-air drier and dried and solidified.

In order to continuously orient the magnetic easy axis of the ferromagnetic iron oxide powder in the magnetic layer in the in-plane direction with respect to the magnetic layer, the magnetic layer is moved during molding. What is necessary is just to let it pass through the magnetic field of the magnetic flux parallel to a direction. For example, as shown in FIG. 6, a method of extruding a magnetic layer 6 into a sheet or a method of passing through a soleinod immediately after applying the magnetic coating film on a nonmagnetic support 5 as shown in FIG. Alternatively, as shown in FIG. 7, permanent magnets 12 for orientation are arranged on both sides of a non-magnetic support 5 (hereinafter, referred to as an oriented body 13) having the magnetic coating film or the magnetic layer 6. By causing repulsion from the front and back of the alignment target 13, a magnetic flux is generated in the traveling direction of the alignment target 13,
The object 13 is passed through the space where the magnetic flux is generated,
There is a method of orienting the easy axis in the in-plane direction.

When the magnetic layer is formed by a plastic molding method, a white sheet such as ordinary printing paper, synthetic paper or a white synthetic film can be used as the nonmagnetic support. When the magnetic layer is formed by coating, a coated paper, a synthetic paper or a white synthetic film whose surface is coated with a resin, so that the solvent does not permeate on the back side of the magnetic paint applied surface of the nonmagnetic support, is used. It is desirable to use. As a specific example, a white polyester film or the like whose surface has been subjected to an easy adhesion treatment can be given.

[0044]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

Example 1 A pair of columnar rare earth permanent magnets (hereinafter, referred to as magnet rolls) in which N poles and S poles were alternately radially magnetized in the circumferential direction were used for the magnetic layer of the magnetic body. The magnet roll is disposed on the surface side and the opposite surface side with the same pole facing each other with the magnetic body sandwiched therebetween with the same pole facing each other, and along the easy axis of magnetization, the magnet roll always faces up and down. Were rotated synchronously, and after the magnetizing process, a magnetizing device as shown in FIG. 3 having a mechanism for sending out the magnetized magnetic attraction sheet was manufactured. The maximum value of the magnetic field between the magnet rolls in the tangential direction perpendicular to the longitudinal direction is 60.
00 Gauss.

The components shown in Table 1 below were mixed by a ball mill and uniformly dispersed to prepare a magnetic paint. After 0.3 parts by weight of a curing agent (Coronate HL) was added to this coating material, the coating material was applied to the back side of the printing surface of a base material: a white synthetic paper with an ink jet-compatible receiving layer (0.08 mm in thickness) using a knife coater. Next, an in-plane orientation magnetic field 400 by a solenoid is used.
After passing through 0 Gauss and performing in-plane orientation, drying is performed to obtain a raw material having a magnetic layer in-plane squareness ratio of 89%, a magnetic layer thickness of 0.05 mm, and a total thickness of 0.13 mm. Was. The obtained raw material was stored in an environment of 50 ° C. for 20 hours or more and subjected to a curing treatment to obtain a magnetized body.

[Table 1]

The magnetized body was magnetized by the magnetizing device as shown in FIG. 3 to produce a magnetically attractable sheet of Example 1.

Example 2 The procedure of Example 1 was repeated, except that a magnetizing device having a maximum tangential magnetic field between the magnet rolls in the tangential direction perpendicular to the longitudinal direction of 8000 Gauss as shown in FIG. 3 was used. A magnetic attraction sheet was produced.

Embodiment 3 A pair of prismatic rare earth permanent magnets (hereinafter, referred to as magnet bars) in which N and S poles are alternately multipolar magnetized in the longitudinal direction.
Are disposed close to each other on the surface of the magnetic body on which the magnetic layer is provided and on the side opposite to the magnetic layer in a parallel state so that the same poles are opposed to each other. A magnetizing device for moving the magnetic body as shown in FIG. 5 was manufactured. There is a gap of less than 0.5 mm between the magnet bars, and the maximum value of the magnetic field in the longitudinal direction between the magnet rolls is 6000 Gauss.
s. A magnetic attraction sheet was produced in the same manner as in Example 1 except that this magnetizing device was used.

Embodiment 4 The maximum value of the magnetic field in the longitudinal direction between the magnet bars is 8000 Gau.
A magnetic attraction sheet was produced in the same manner as in Example 3 except that a magnetizing device as shown in FIG.

Example 5 A magnetic attraction sheet was produced in the same manner as in Example 1 except that the coercive force Hc of the magnetic powder in Table 1 was changed to 3500 Oe.

Example 6 A magnetic attraction sheet was prepared in the same manner as in Example 2 except that the coercive force Hc of the magnetic powder shown in Table 1 was changed to 3500 Oe.

Example 7 A magnetic attraction sheet was prepared in the same manner as in Example 3 except that the coercive force Hc of the magnetic powder shown in Table 1 was changed to 3500 Oe.

Example 8 A magnetic attraction sheet was prepared in the same manner as in Example 4 except that the coercive force Hc of the magnetic powder in Table 1 was changed to 3500 Oe.

Comparative Example 1 A magnetically attractable sheet was produced in the same manner as in Example 1 except that a magnetizing device as shown in FIG. 9 was used. The obtained magnetically attracting sheet is a magnetically attracting sheet in which the magnetic powder is oriented so as to have an easy axis of magnetization in a direction perpendicular to the plane of the magnetic layer as shown in FIG. Met.

With respect to the magnetic attraction sheets of the respective examples and comparative examples, the surface magnetic flux density and the magnetic attraction force were evaluated.

For evaluation of the surface magnetic flux density, the maximum value of the magnetic flux density in the vertical direction at zero distance from the surface of the magnetic layer was measured using a Gauss meter, and the measured values at five arbitrary points were averaged.

The magnetic attraction force was evaluated by cutting each magnetic attraction sheet to 100 mm × 100 mm, attaching a resin plate having the same shape as the sheet to the back side of the magnetic attraction surface with an adhesive, and fixing it horizontally to a 0.5 mm thickness. The minimum peeling force when peeling vertically above the steel plate by magnetically adsorbing it on the steel plate is measured with a spring balance, and (peeling force-(sheet weight + adhesive weight + resin plate weight)) / sheet area = magnetism Adsorption power.

The results are shown in Table 2 below.

[0060]

[Table 2]

As is clear from Table 2, the magnetic attraction sheet according to the present invention has a magnetic coating film in which the easy axis is oriented in the in-plane direction with respect to the magnetic layer, in the direction of the easy axis. Are multipolar magnetized as in (NS) (SN) (NS)..., The distance between the magnetic poles does not depend on the thickness of the magnetic layer. Even when the thickness of the magnetic layer was reduced, the distance between the magnetic poles could be sufficiently ensured, and the demagnetizing field was not increased and demagnetization was difficult. Further, a maximum leakage magnetic flux in the vertical direction can be generated from the opposed magnetic pole surface of SS or NN to the magnetic layer, and, for example, a ferromagnetic wall surface of a steel plate as the object to be attracted. It can be seen that the magnetic attraction force can be effectively exerted during the period.

On the other hand, since the magnetic attraction sheet of Comparative Example 1 is oriented and magnetized in the direction perpendicular to the magnetic layer surface, the distance between the magnetic poles is equal to the thickness of the magnetic layer, and the total thickness of the magnetic attraction sheet is Is as thin as 0.13 mm, the distance between the magnetic poles becomes too close, and accordingly, the demagnetizing field increases,
It is easily demagnetized and has poor magnetic attraction.

The magnetic attraction sheets of Examples 1 to 4, 6 and 8 generate a maximum magnetic flux density twice or more the coercive force of the magnetic powder, and perform the magnetizing treatment.
The magnetic attraction force more than doubled. The magnetic attraction force of a magnet can be magnetically attracted to a vertical surface in a stationary state if it has an attraction force that is three times or more its own weight empirically. However, disturbance (external vibration, impact, indoor air conditioning) Wind pressure, etc.)
May be easily peeled off. Since the magnetic attraction sheets of Examples 1 to 4 have a magnetic attraction force of 10 times or more of their own weight, they can be more stably magnetically attracted even in an environment where disturbance exists, and have a better magnetic attraction. An adsorption sheet was obtained.

In the magnetic attraction sheets of Examples 5 and 7, the magnetic powder having a coercive force of 3500 Oe was used, the maximum magnetic flux density of the magnetizing device was 6000 Gauss, and the coercive force of the magnetic powder was 2 Since the magnetizing process was performed by generating a maximum magnetic flux density of twice or less, a magnetic attraction force nine times its own weight was obtained.

The coercive force of the magnetic powder is 3000 Oe.
The following magnetic attraction sheet has a maximum magnetic flux density of 6000 Gauss as apparent from the results of Example 1 and Example 3.
It can be seen that the magnetizing device of s can sufficiently magnetize. And as is clear from the results of Example 6 and Example 8,
If the magnetizing device has a maximum magnetic flux density of 8000 Gauss,
It can be seen that a magnetic attraction sheet using a ferromagnetic iron oxide having a larger coercive force can be magnetized.

To obtain the same effect with, for example, a magnetizing coil, a complicated magnetizing yoke, a power supply device and driving power are required. For example, the magnetic field of the rare earth permanent magnet can be used as a magnetic field generation source at the time of performing the magnetic field, so that there is no need to externally take in energy for the magnetization process from outside, and the magnet is semi-permanently magnetized. Therefore, the cost can be reduced more effectively in manufacturing the magnetic attraction sheet according to the present invention.

[0067]

According to the present invention, the magnetic layer has an easy axis of magnetization in the in-plane direction and is multipolarly magnetized in the in-plane direction. Is not dependent on the thickness of the magnetic layer, and even if the thickness of the magnetic layer is reduced, the distance between the magnetic poles can be formed at a desired distance. Further, as the thickness of the magnetic layer is smaller, the distance between the magnetic poles is relatively smaller, and the demagnetizing field is smaller. Therefore, even if the thickness of the magnetic layer is small, the distance between the magnetic poles can be sufficiently ensured, so that the demagnetizing field does not increase and demagnetization is difficult.

The magnet having an easy axis of magnetization in an in-plane direction with respect to the magnetic layer by an orientation means for orienting the axis of easy magnetization in an in-plane direction with respect to the magnetic layer and having magnetic poles alternately Is arranged at least on the magnetic layer surface side of the magnetized body, and the magnetic layer is multipolarly magnetized in the in-plane direction by the magnet, so that the magnetic layer is multipolarly magnetized in the in-plane direction. Unlike the related art, it is not necessary to particularly install a strong magnetic field generator or the like, and the equipment does not become large-scale, so that energy consumption can be reduced and manufacturing cost can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic view of a magnetic attraction sheet according to the present invention at the time of magnetic attraction.

FIG. 2 is a schematic sectional view of a magnetic attraction sheet according to the present invention.

FIG. 3 is a schematic perspective view showing an example of a magnetic attraction sheet magnetizing device according to the present invention.

FIG. 4 is a partially enlarged schematic sectional view showing an example of a magnetizing device for a magnetic attraction sheet according to the present invention.

FIG. 5 is a schematic perspective view showing another example of the magnetic attraction sheet magnetizing device according to the present invention.

FIG. 6 is a schematic view showing a method for orienting a magnetic layer of a magnetic attraction sheet according to the present invention.

FIG. 7 is a schematic view showing a method for orienting a magnetic layer of a magnetic attraction sheet according to the present invention.

FIG. 8 is a schematic view of a magnetic attraction sheet according to a conventional example at the time of magnetic attraction.

FIG. 9 is a schematic view showing a method of magnetizing a magnetic attraction sheet according to a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic attraction sheet, 2 ... Attracted object, 3 ... Unit magnet, 4
... Distance between magnetic poles, 5 ... Non-magnetic support, 6 ... Magnetic layer, 7 ... Print receiving layer, 8 ... Bulletin board, 9 ... Cylindrical permanent magnet, 10 ...
Magnetized body, 11: prismatic permanent magnet, 12: permanent magnet for orientation, 13: oriented body

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Eiji Ota 6-7-35 Kita Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation

Claims (50)

[Claims] 1. A magnetic attraction sheet comprising a magnetic layer, wherein the magnetic layer has an easy axis of magnetization in an in-plane direction and is multipolarly magnetized in the in-plane direction. 2. The magnetic attraction sheet according to claim 1, wherein the magnetic layer is multipolarly magnetized so that a polarization direction is alternately reversed in the in-plane direction. 3. A print receiving layer is provided on the magnetic layer,
The magnetic attraction sheet according to claim 1. 4. The printing receiving layer is printed.
The magnetic attraction sheet according to claim 3. 5. The magnetic layer mainly composed of a magnetic powder and a binder is formed on a non-magnetic support, and the magnetic layer has an in-plane squareness ratio of 80% or more with respect to the magnetic layer. The magnetic attraction sheet according to claim 1, wherein the axes are oriented. 6. The thickness of the non-magnetic support is from 0.05 to 0.05.
0.15 mm, the coercive force of the magnetic powder is 700-4000
Oe, The magnetic attraction sheet according to claim 5, wherein the thickness of the magnetic layer is 0.03 to 0.1 mm and the total thickness is 0.08 to 0.25 mm. 7. A step of orienting an axis of easy magnetization in an in-plane direction with respect to the magnetic layer when producing a magnetically attractable sheet by magnetizing a magnetized body having at least a magnetic layer; Disposing a magnet having at least a side of the magnetic layer on the surface of the magnetic layer, and magnetizing the magnetic layer in the in-plane direction with the magnet. 8. An apparatus according to claim 1, wherein the north pole and the south pole are alternately magnetized.
A pair of magnets are disposed close to each other on the side of the magnetic body to be provided with the magnetic layer and on the side opposite to the magnetic layer so that the same poles face each other. The method of manufacturing a magnetically attractable sheet according to claim 7, wherein the multi-polarization is performed such that the polarization direction is alternately reversed in the in-plane direction. 9. A pair of columnar permanent magnets in which N poles and S poles are alternately radially magnetized in the circumferential direction, and a pair of columnar permanent magnets having the magnetic layer on the surface to be magnetized and the opposite surface thereof. 9. The magnetic device according to claim 8, wherein the magnetic poles are disposed close to each other with the same poles facing each other, and are synchronously rotated along the easy axis with the same poles always facing up and down. A method for manufacturing an adsorption sheet. 10. A pair of prism-shaped permanent magnets in which N poles and S poles are alternately multipolar magnetized in the longitudinal direction, and a pair of the magnetized body having the magnetic layer and the opposite side. Side, the magnetized body is disposed close to and sandwiched such that the same poles face each other, and the magnetized body is moved in a direction orthogonal to the easy axis of magnetization.
A method for manufacturing a magnetic attraction sheet according to claim 8. 11. The magnetic layer mainly composed of a magnetic powder and a binder is formed on a non-magnetic support, and the magnetic layer is formed so as to have an in-plane squareness ratio of 80% or more with respect to the magnetic layer. The method for producing a magnetic attraction sheet according to claim 7, wherein the axes are oriented. 12. The thickness of the non-magnetic support is 0.05 to
0.15 mm, the coercive force of the magnetic powder is 700-4000
The method of manufacturing a magnetic attraction sheet according to claim 11, wherein Oe, the thickness of the magnetic layer is 0.03 to 0.1 mm, and the total thickness is 0.08 to 0.25 mm. 13. The method for manufacturing a magnetic attraction sheet according to claim 12, wherein when the magnets are magnetized with the same polarity facing each other, a maximum magnetic flux density that is at least twice the coercive force of the magnetic powder is generated. 14. The method according to claim 7, wherein the magnetic layer is formed, and the magnetizing treatment is performed immediately after the step of aligning the easy axis. 15. The method according to claim 7, wherein after the step of aligning the easy axis, the magnetic layer is formed, the magnetic layer is wound once, and the magnetized body is cut into a predetermined size, and then the magnetizing process is performed. Of producing a magnetically attractable sheet. 16. A print receiving layer is formed on the magnetic layer,
The method according to claim 7, wherein after the step of aligning the axis of easy magnetization, the magnetized body is wound once, the magnetized body is cut into a predetermined size, and the magnetizing process is performed simultaneously with printing on the print receiving layer. Of producing a magnetically attractable sheet. 17. A print receiving layer is formed on the magnetic layer,
After the step of orienting the easy axis, winding is performed once, the magnetized body is cut into a predetermined size, and the magnetizing process is performed after or before printing on the print receiving layer. 7. The method for producing a magnetic attraction sheet according to item 7. 18. A magnetized sheet for a magnetic attraction sheet having a magnetic layer in which an axis of easy magnetization is oriented in an in-plane direction when magnetizing a magnet having magnetic poles alternately at least in the magnetized sheet. A method for magnetizing a magnetically attractable sheet, wherein the magnetizing sheet is disposed on the magnetic layer surface side and the magnetic layer is multipolarly magnetized in the in-plane direction by the magnet. 19. A pair of magnets having N poles and S poles alternately magnetized, the magnets being opposite to each other on the side of the magnetic body on which the magnetic layer is provided and on the opposite side thereof. 19. The method for magnetizing a magnetic attraction sheet according to claim 18, wherein the magnetic layer is multi-polarized by the pair of magnets such that the polarization direction is alternately reversed in the in-plane direction. . 20. A pair of cylindrical permanent magnets in which N poles and S poles are alternately radially magnetized in a circumferential direction, and a pair of columnar permanent magnets having the magnetic layer on the surface to be magnetized and the opposite surface thereof. 20. The magnetic device according to claim 19, wherein the magnetic poles are arranged close to each other with the same poles facing each other with the same poles facing each other, and are synchronously rotated with the same poles always facing up and down along the easy axis of magnetization. How to magnetize the suction sheet. 21. A pair of prism-shaped permanent magnets in which N poles and S poles are alternately multipolarly magnetized in a longitudinal direction, and a pair of the magnetized body having the magnetic layer and the opposite side. Side, the magnetized body is disposed close to and sandwiched such that the same poles face each other, and the magnetized body is moved in a direction orthogonal to the easy axis of magnetization.
The method for magnetizing a magnetic attraction sheet according to claim 19. 22. The magnetic layer mainly composed of a magnetic powder and a binder is formed on a non-magnetic support, and the magnetic layer has an in-plane squareness ratio of 80% or more with respect to the magnetic layer. 19. The method for magnetizing a magnetically attracting sheet according to claim 18, wherein the magnetized object for a magnetically attracting sheet having the magnetic layer whose axis is oriented is subjected to the magnetizing treatment. 23. The thickness of the nonmagnetic support is set to 0.05 to
0.15 mm, the coercive force of the magnetic powder is 700-4000
23. The method of magnetizing a magnetic attraction sheet according to claim 22, wherein Oe, the thickness of the magnetic layer is 0.03 to 0.1 mm, and the total thickness is 0.08 to 0.25 mm. 24. The method according to claim 23, wherein, when the magnets are magnetized with the same polarity facing each other, a maximum magnetic flux density of at least twice the coercive force of the magnetic powder is generated. 25. The method according to claim 18, wherein the magnetizing treatment is performed immediately after the step of orienting the easy axis. 26. The magnetization of the magnetic attraction sheet according to claim 18, wherein after the step of orienting the easy axis, the magnetized sheet is wound once, and the magnetization is performed after cutting the magnetized body to a predetermined size. Method. 27. A print receiving layer is formed on the magnetic layer,
19. The method according to claim 18, wherein after the step of orienting the easy axis, the magnetized body is wound once, the magnetized body is cut into a predetermined size, and the magnetizing process is performed simultaneously with printing on the print receiving layer. Method of magnetizing a magnetically attracted sheet. 28. A print receiving layer is formed on the magnetic layer,
After the step of orienting the easy axis, winding is performed once, the magnetized body is cut into a predetermined size, and the magnetizing process is performed after or before printing on the print receiving layer. 19. The method for magnetizing a magnetic attraction sheet according to item 18. 29. An apparatus for producing a magnetically attractable sheet by subjecting a magnetized body having at least a magnetic layer to a magnetizing process, comprising: means for orienting an easy axis of magnetization in an in-plane direction with respect to the magnetic layer; A magnetism attracting sheet comprising: magnets having magnetic poles alternately arranged at least on the magnetic layer surface side of the magnetized body; and magnetizing means for multipolarly magnetizing the magnetic layer in the in-plane direction by the magnet. Manufacturing equipment. 30. A pair of magnets in which N poles and S poles are alternately magnetized have the same poles facing each other on the surface side of the magnetic body to be provided with the magnetic layer and on the opposite surface side. 30. The production of a magnetic attraction sheet according to claim 29, wherein the magnetic layer is multi-polarized by the pair of magnets such that the polarization direction is alternately reversed in the in-plane direction. apparatus. 31. A pair of columnar permanent magnets in which N poles and S poles are alternately radially magnetized in the circumferential direction are formed on a surface side of the magnetized body having the magnetic layer and a surface side opposite thereto. Are arranged close to each other with the poles facing each other with the magnetized body interposed therebetween,
31. The apparatus for manufacturing a magnetic attraction sheet according to claim 30, wherein the magnetic poles are synchronously rotated with the same pole always vertically facing along the easy axis. 32. A pair of prism-shaped permanent magnets in which N-poles and S-poles are alternately multipolarly magnetized in a longitudinal direction, and a surface of the magnetized body having the magnetic layer and a surface opposite thereto. 31. The magnetic attraction sheet according to claim 30, wherein the magnetic pole sheet is disposed close to the magnetic pole so that the same poles face each other, and the magnetic pole is moved in a direction orthogonal to the easy axis of magnetization. manufacturing device. 33. The magnetic layer mainly comprising magnetic powder and a binder is formed on a non-magnetic support, and the magnetic layer is formed so as to have an in-plane squareness ratio of 80% or more with respect to the magnetic layer. 30. The apparatus of claim 29, wherein the axes are oriented. 34. The thickness of the nonmagnetic support is set to 0.05 to
0.15 mm, the coercive force of the magnetic powder is 700-4000
34. The apparatus for manufacturing a magnetic attraction sheet according to claim 33, wherein Oe, the thickness of the magnetic layer is 0.03 to 0.1 mm, and the total thickness is 0.08 to 0.25 mm. 35. The apparatus for manufacturing a magnetic attraction sheet according to claim 34, wherein when the magnets are magnetized with the same polarity facing each other, a maximum magnetic flux density of at least twice the coercive force of the magnetic powder is generated. . 36. The apparatus for manufacturing a magnetic attraction sheet according to claim 29, wherein the magnetic layer is formed, and the magnetization process is performed immediately after the step of aligning the easy axis. 37. The method according to claim 37, wherein the magnetic layer is formed, is wound once after the step of orienting the easy axis, and is subjected to the magnetizing process after the magnetized body is cut into a predetermined size. 29. The apparatus for manufacturing a magnetic attraction sheet according to 29. 38. A print receiving layer is formed on the magnetic layer, and after the easy axis orientation step, the print receiving layer is wound once, and the magnetized body is cut into a predetermined size. The magnetizing process is performed simultaneously with printing.
An apparatus for manufacturing a magnetic attraction sheet according to claim 29. 39. A print receiving layer is formed on the magnetic layer, and after the step of orienting the axis of easy magnetization, is wound once, and the magnetized body is cut into a predetermined size. 30. The apparatus according to claim 29, wherein the magnetizing process is performed after or before printing is performed. 40. An apparatus for magnetizing a magnetic body for a magnetic attraction sheet having a magnetic layer in which an axis of easy magnetization is oriented in an in-plane direction, wherein the magnet having alternating magnetic poles is attached to the magnetic layer. A magnetizing device for a magnetic attraction sheet, comprising: magnetizing means disposed at least on the magnetic layer surface side of a magnetic body and magnetizing the magnetic layer in the in-plane direction by this magnet. 41. A pair of magnets in which N poles and S poles are alternately magnetized have the same poles facing each other on the surface side of the magnetic body on which the magnetic layer is provided and on the opposite surface side. 41. The magnetization of the magnetic attraction sheet according to claim 40, wherein the magnetic layer is magnetized so that the polarization direction is alternately reversed in the in-plane direction by the pair of magnets. apparatus. 42. A pair of columnar permanent magnets in which N poles and S poles are alternately radially magnetized in the circumferential direction are provided on a surface side of the magnetized body on which the magnetic layer is provided and on a surface side opposite thereto. Are arranged close to each other with the poles facing each other with the magnetized body interposed therebetween,
42. The magnetizing apparatus for a magnetic attraction sheet according to claim 41, wherein the magnetic poles are synchronously rotated along the easy axis with the same pole always facing up and down. 43. A pair of prism-shaped permanent magnets in which N-poles and S-poles are alternately multipolarly magnetized in a longitudinal direction, and a surface of the magnetized body having the magnetic layer and a surface opposite thereto. 42. The magnetic adsorption sheet according to claim 41, wherein the magnetized sheet is disposed closer to the side with the same poles opposed to each other across the magnetized body, and the magnetized body is moved in a direction perpendicular to the easy axis of magnetization. Magnetizer. 44. The magnetic layer mainly comprising a magnetic powder and a binder is formed on a non-magnetic support, and the magnetic layer is formed so as to have an in-plane squareness ratio of 80% or more with respect to the magnetic layer. 41. The magnetizing apparatus for a magnetic attraction sheet according to claim 40, wherein the magnetized object for a magnetic attraction sheet having the magnetic layer whose axis is oriented is subjected to the magnetization processing. 45. The thickness of the nonmagnetic support is 0.05 to
0.15 mm, the coercive force of the magnetic powder is 700-4000
45. The magnetizing apparatus of claim 44, wherein Oe, the thickness of the magnetic layer is 0.03-0.1 mm, and the total thickness is 0.08-0.25 mm. 46. The magnetization of the magnetic attraction sheet according to claim 45, wherein when the magnets are magnetized with the same polarity facing each other, a maximum magnetic flux density of at least twice the coercive force of the magnetic powder is generated. apparatus. 47. The magnetizing apparatus for a magnetic attraction sheet according to claim 40, wherein the magnetizing treatment is performed immediately after the easy axis orientation step. 48. The magnetic attraction sheet according to claim 40, wherein after the step of orienting the easy axis, the magnetically attracting sheet is wound once, and the magnetizing process is performed after the magnetized body is cut into a predetermined size. Magnetizing device. 49. A print receiving layer is formed on the magnetic layer, and after the step of aligning the axis of easy magnetization, the print receiving layer is wound once, and the magnetized body is cut into a predetermined size. The magnetizing process is performed simultaneously with printing.
A magnetizing device for a magnetic attraction sheet according to claim 40. 50. A print-receiving layer is formed on the magnetic layer, and after the step of orienting the axis of easy magnetization, is wound once, and the magnetized body is cut into a predetermined size. The magnetizing device for a magnetic attraction sheet according to claim 40, wherein the magnetizing process is performed after or before printing is performed.