JP3217413B2 - Visible display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Object of the invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a structure in which a plurality of microcapsules containing magnetic flakes together with oil and changing the reflection direction of visible incident light according to the orientation direction are arranged on the surface of a transparent substrate. A magnetic field for forming a microcapsule layer functioning as a visible display area by dispersing in a binder and changing the orientation direction of magnetic flakes contained in the microcapsules of the microcapsule layer with respect to the surface of the microcapsule layer In particular, the present invention relates to a visible display device provided with a magnetic sheet that generates a magnetic sheet. In particular, the binder of the microcapsule layer is formed of a water-soluble resin, and the microcapsule layer is disposed on the transparent substrate and the magnetic sheet via an adhesive layer. The present invention relates to a visible display device which is joined by joining.

[0003]

2. Description of the Related Art Conventionally, as a visible display device of this kind,
As the visual display device 10 shown in FIG. 4, to form a microcapsule layer 30 by arranging the several layers laminated with an adhesive 35 microcapsules 32 to one surface of the transparent substrate 20, and a microcapsule layer Magnetic sheet 40 on the surface of 30
Has been proposed to be directly arranged.

[0004]

[Problems to be Solved] However, in the conventional visual display device 10 , since the microcapsules 32 are laminated and arranged in the adhesive 35, (i) the microcapsules 32 are arranged in contact with each other. There is a disadvantage that the bonding force between the microcapsules 32 is insufficient, and eventually (ii) the mechanical strength is inferior, and there is a disadvantage that the microcapsules 32 are easily broken when pressed from the magnetic sheet 40 side, In addition, (iii) there is a disadvantage that the manufacturing process becomes complicated and high precision, and further (iv) there is a disadvantage that a step corresponding to the thickness of the microcapsules 32 occurs in the peripheral portion and the aesthetic feeling is impaired. there were.

[0005] Therefore, in order to eliminate these drawbacks, the present invention forms the binder of the microcapsule layer with a water-soluble resin, and forms the microcapsule layer on the transparent substrate and the magnetic sheet via an adhesive layer. It is intended to provide a visible display device which is joined by bonding.

[0006]

Configuration of the Invention

[0007]

A solution to the problem provided by the present invention is that a plurality of microcapsules, which contain magnetic flakes together with oil and change the reflection direction of visible incident light according to the orientation direction, are transparent. Magnetic flakes formed in the microcapsules of the microcapsule layer on the surface of the microcapsule layer by forming a microcapsule layer that functions as a visible display area by dispersing in a binder disposed on the surface of the base material In a visible display device provided with a magnetic sheet that generates a magnetic field for changing the orientation direction of a microcapsule layer, a binder of a microcapsule layer is formed of a water-soluble resin, and the microcapsule layer is formed of a transparent substrate and a magnetic sheet. visual display instrumentation, characterized by comprising bonded via respective adhesive layers to (50, 60) "It is.

[0008]

The visual display device according to the present invention contains magnetic flakes together with oil and changes the reflection direction of the visible incident light according to the orientation direction, as specified in the above-mentioned "Means for Solving the Problems". A plurality of microcapsules to be dispersed are dispersed in a binder disposed on the surface of the transparent substrate to form a microcapsule layer functioning as a visible display area, and the microcapsules of the microcapsule layer on the surface of the microcapsule layer A visible display device comprising a magnetic sheet for generating a magnetic field for changing the orientation direction of magnetic flakes contained therein, and in particular, a binder for a microcapsule layer is formed of a water-soluble resin. And the microcapsule layer is bonded to the transparent substrate and the magnetic sheet via an adhesive layer, respectively, so that (i) It acts to prevent the microcapsules from being stacked in contact with each other, and thus (i
i) works to improve mechanical strength by preventing insufficient bonding force between microcapsules, (iii) works to simplify the manufacturing process, and (iv) steps occur in the peripheral area It acts to improve the beauty by avoiding doing so.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of a visible display device according to the present invention will be described in detail with reference to the accompanying drawings.

However, the embodiments described below are:
It is described for the purpose of facilitating or facilitating the understanding of the present invention and is not described for limiting the present invention.

In other words, each element disclosed in the embodiments described below includes all design changes and equivalent replacements that fall within the spirit and scope of the present invention.

(Description of the accompanying drawings)

FIG. 1 is a perspective view, partially in section, showing an embodiment of the visible display device according to the present invention. In particular, a microcapsule layer functioning as a visible display region on one surface of a transparent substrate 20 is shown. 30 is arranged through an adhesive layer 50, and shows a state in which the magnetic sheet 40 to the surface of the microcapsule layer 30 is disposed over the adhesive layer 60 to form a magnetic field for the visual display I have.

FIG. 2 is a partially enlarged sectional view showing the operation of the embodiment shown in FIG. 1. In particular, the magnetization state of the magnetic sheet 40 and the microcapsules in the microcapsule layer 30 are shown.
The correlation between the orientation direction of the magnetic flakes 34 accommodated in 32 is shown.

FIGS. 3A and 3B are flow charts showing an example of the manufacturing procedure of the embodiment shown in FIG.

(Configuration of Embodiment)

First, the configuration of an embodiment of the visible display device according to the present invention will be described in detail with reference to FIGS.

[0018] 10 is a visual display device according to the present invention (e.g., a magnetic card), the transparent substrate 20, the transparent substrate 20
A microcapsule layer 30 arranged on one surface of the
Holds the magnetic recording area and the recorded contents of the magnetic recording area
The magnetic sheet 40 disposed on the surface of the microcapsule layer 30 so as to form a magnetic field for visible display according to (i.e., the magnetization state), and the microcapsule layer 30 on one surface of the transparent substrate 20. Adhesive layer for joining and placing
50 and a magnetic sheet for the surface of the microcapsule layer 30
And another adhesive layer 60 for bonding and arranging 40 .

The transparent substrate 20 is made of a transparent material (for example, a polyethylene terephthalate film) having a required thickness (for example, 100 to 250 μm) to secure the strength, and serves as a holder for the microcapsule layer 30. It is functioning.

The microcapsule layer 30 includes a binder 31 made of a suitable water-soluble resin and a plurality of microcapsules 32 dispersed in the binder 31. The thickness of the microcapsule layer 30 is about 150 μm so that the visible incident light L can be sufficiently reflected and clearly displayed when the recorded contents of the magnetic recording area included in the magnetic sheet 40 are displayed visually. Is preferred.

The binder 31 is formed of an appropriate water-soluble resin such as polyvinyl alcohol or carboxymethyl cellulose, and transmits visible incident light L and visible reflected lights L ^* and L ^** . The binder 31 is particularly preferably transparent. If the binder 31 is formed of polyvinyl alcohol, as is apparent from the chemical formula 1, the ethylene-vinyl acetate copolymer shown in chemical formula 2 is adopted as the resin matrix of the adhesive layers 50 and 60 , so that the binder 31 This is preferable because the chemical structure of the adhesive layers 50 and 60 with the resin matrix can be approached, and the adhesive force between the binder 31 and the adhesive layers 50 and 60 can be sufficiently ensured.

[0022]

Embedded image [—CH ₂ .CH (OH) .CH ₂ .CH (OCOCH ₃ ) —] _n

[0023]

## STR2 ## _{[-CH 2 · CH 2 · CH} 2 · CH (OCOCH 3) -] n

The microcapsules 32 are made of a suitable hydrophobic solvent
(So-called "oil") 33 and the magnetization state in the magnetic recording area of the magnetic sheet 40 are dispersed in the oil 33 (i.e. the magnetization direction) in the magnetic recording area of the alignment is made to vary the magnetic sheet 40 according to the And a magnetic flake 34 that allows the recorded content held in the storage device to be visually recognized. The size of the microcapsules 32 is set such that the visible incident light L is sufficiently reflected and clearly displayed when the recorded contents of the magnetic recording area included in the magnetic sheet 40 are displayed in a visible manner.
It is preferable that the thickness be about μm to 100 μm.

As the hydrophobic solvent (that is, oil) 33, dodecylbenzene or liquid paraffin is preferred.

The magnetic flake 34 is preferably a magnetic metal powder containing iron or nickel. The magnetic flakes 34 may contain, in addition to iron or nickel, at least one magnetic metal selected from silicon, molybdenum, aluminum, chromium, cobalt, and the like.

The magnetic flakes 34 must appropriately reflect the visible incident light L, and the visible reflected light L emitted to the outside of the transparent substrate 20 when the orientation direction is parallel to the surface.
Since it is necessary to remarkably increase the light amount of ^* , it is preferable that the shape is a plate. The size of the magnetic flakes 34 must be appropriately determined according to the size of the microcapsules 32 and the like. If the major axis is 5 to 30 μm, the minor axis is 1 to 10 μm, and the thickness is 0.1 to 1 μm, Is usually preferred.

The magnetic flakes 34 are surrounded by magnetic flakes.
For the purpose of preventing the aggregates 34 from aggregating with each other or adhering to the wall surface of the microcapsules 32, if necessary, a suitable surfactant that is difficult to react with the magnetic flakes 34 and the oil 33.
(For example, span 80 (sorbitan monooleate manufactured by Atlas Powder) or oleic acid).

The magnetic sheet 40, to the surface of a suitable substrate such as plastic film brought arranged magnetic film (called "magnetic layer") are prepared in a known manner, the position in the vicinity of the microcapsule layer 30 The magnetic recording area is provided.

The adhesive layer 50 is formed by applying an adhesive prepared by mixing a tackifier resin with a resin matrix in an appropriate ratio on the transparent base material 20 before disposing the microcapsule layer 30 . Is formed. The adhesive layer 60 is formed by mixing an adhesive prepared by mixing a tackifying resin with a resin matrix in an appropriate ratio, prior to disposing the magnetic sheet 40 ,
It is formed by applying it to 40 surfaces.

The thickness of the adhesive layer 50 may be appropriately determined so as to secure sufficient strength. Particularly, when the thickness is about 50 μm, the strength can be secured and the visible incident light L and the visible reflected light L ^* , It is preferable because L ^** can be transmitted. The thickness of the adhesive layer 60 may be appropriately determined so as to ensure sufficient strength. Particularly, if the thickness is 30 μm or less, the strength can be ensured and the magnetic property contained in the microcapsules 32 in the microcapsule layer 30 can be ensured. The flakes 34 are preferable because they can sufficiently respond to the magnetic field formed according to the magnetization state in the magnetic recording area of the magnetic sheet 40 .

The adhesive for forming the adhesive layers 50 and 60 is preferably a hot-melt adhesive, that is, a hot-melt adhesive, because it is easy to handle. The melting temperature of the adhesive is preferably about 90 to 120 ° C. because it is necessary to prevent the magnetic layer of the magnetic sheet 40 from being broken.

The adhesive layer 50 resin matrix is also visible reflected light L ^* from allowed transmit visible incident light L and the microcapsule layer 30 of microcapsules layer 30, it is necessary to allowed to transmit L ^** In particular, it is preferable if it is transparent. The resin matrix of the adhesive layer 60 needs to transmit the visible incident light L from the microcapsule layer 30 and transmit the visible reflected light L ^** to the microcapsule layer 30 . . As the resin matrix of the adhesive layers 50 and 60 , thermoplastic resins such as ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, polyamide, and polyester are preferable. The ethylene-vinyl acetate copolymer is particularly preferable because it has good wettability with a polyethylene terephthalate film used as a material of the transparent substrate 20 , and has good compatibility with various tackifying resins.

The ethylene-vinyl acetate copolymer is preferred if the melt index is about 150 to 1000 and the vinyl acetate content is about 19 to 33%, since the coating step can be simplified.

The tackifier resin can be generally employed as long as it is compatible with the resin matrix. Tackifying resins, visible reflected light L ^* from the visible incident light L and the microcapsule layer 30 of microcapsules layer 30, it is necessary to allowed to transmit L ^**, especially if and clear colorless to yellow ,preferable. The tackifier resin is preferably a rosin resin or an alicyclic saturated hydrocarbon, for example, because it is transparent, colorless to yellow, and has high adhesive strength. Specifically, Super Ester A-100, Pencel A, Pencel X, Ester Gum AAL, Ester Gum A
A commercially available product such as AV, Ester Gum 106, Ester Gum H, Special Rosin Ester KE-311 or Alcon may be used.

The mixing ratio of the tackifier resin to the resin matrix is preferably 1: 2 to 3 for the purpose of securing the adhesive force of the adhesive.

(Manufacturing procedure)

Further, with reference to FIGS. 1 to 3B, an example of the manufacturing procedure of the visible display device according to the embodiment of the present invention will be specifically described for better understanding.

Dispersion of magnetic flakes 34

A suitably shaped (eg, plate-shaped) magnetic metal powder (ie, “magnetic flake”) 34 prepared in a well-known manner is provided with a suitable surfactant (eg, oleic acid).
And dispersed in a hydrophobic solvent (ie, “oil”) 33 (the resulting product is referred to as “magnetic flake dispersion”), and then stored in a stirrer (eg, an ultrasonic stirrer) for a sufficient time. With stirring.

Preparation of microcapsule 32

Water, gelatin, gum arabic, and the like are mixed at an appropriate ratio and sufficiently stirred to prepare a gelatin rubber mixed solution to be the wall surface of the microcapsule 32.
The gelatin rubber mixture may be prepared, for example, by mixing 650 cc of water, 10 g of gelatin (isoelectric point pH 4.5), and 10 g of gum arabic, and thoroughly stirring the mixture.
Hereinafter, this case will be exemplified, but the present invention is not limited to this. As long as the wall surface of the microcapsule 32 can be formed, a desired material may be used in a desired ratio.

The gelatin rubber mixture is heated to an appropriate temperature while stirring is continued after the stirring has progressed to an appropriate degree, in order to facilitate the reaction.

The magnetic flake dispersion is added little by little to the gelatin rubber mixture under stirring, mixed, and stirred for an appropriate time to disperse the fine particles of the magnetic flake dispersion (result product). For “intermediate dispersion”
).

An aqueous acetic acid solution (for example, 10% by weight) is added dropwise to the intermediate dispersion until the pH becomes 4 while continuing stirring. This results in a membrane of gelatin and gum arabic coacervate (ie, “microcapsules 32”) around the microparticles of the magnetic flake dispersion (essentially oil 33).
Is formed.

The dripped intermediate dispersion of the aqueous acetic acid solution is a coacervate film of gelatin and gum arabic (ie "") placed around the microparticles of the magnetic flake dispersion (essentially oil 33). The microcapsules 32 are cooled to an appropriate temperature with stirring for the purpose of solidifying the wall surface “)”.

The cooled intermediate dispersion contains gelatin and gum arabic formed around the microparticles of the magnetic flake dispersion (substantially oil 33) by binding to the deprotonated amino groups in the gelatin. Coacervate membrane
An appropriate amount of formaldehyde is added to further coagulate (ie, the “wall surface of the microcapsules 32”). As a result, the microcapsules 32 are dispersed in gelatin and gum arabic (this is called “microcapsule liquid”). The microcapsules 32 contain a magnetic flake dispersion (therefore, magnetic flakes 34 and oil 33).

An aqueous solution of sodium carbonate (for example, 20% by weight) is added to the microcapsule solution for the purpose of promoting the elimination of protons from the amino groups of the gelatin while continuing stirring.
Add dropwise until pH 9.5.

The microcapsule solution is allowed to stand for a further sufficient time.
After being stirred for (for example, 3 to 30 hours), the microcapsules 32 are allowed to stand for an appropriate time (for example, 24 hours) in order to cause the microcapsules 32 to float (hereinafter, referred to as “floating capsules”).

Removal of empty capsules

The floating capsule in the microcapsule liquid is
It is taken out by an appropriate means. Pure water is added to the removed floating capsule (the resulting product is referred to as “floating capsule liquid”).

After the suspension capsule liquid is agitated for a sufficient time, it is placed in a magnetic field of an appropriate strength to remove the microcapsules not containing the magnetic flakes 34 (called “empty capsules”).

In the floating capsule liquid, it is determined whether or not the residual amount of the empty capsule is equal to or less than a predetermined value in the residual amount determining step of the empty capsule.

The process of adding pure water or the process of determining the remaining amount of empty capsules is repeated until the remaining amount of empty capsules is equal to or less than the predetermined value, and the empty capsules are removed.

Dispersion to binder 31

When the remaining amount of the empty capsules becomes equal to or less than a predetermined value, the material of the binder 31 (ie, “water-soluble resin”) is added and stirred (the resulting product is called “microcapsule dispersion liquid”). ).

The microcapsule dispersion has an appropriate concentration.
(For example, the concentration of microcapsules is adjusted to 50% by weight).

Preparation of adhesive layer 50

The hot melt adhesive prepared by mixing the tackifying resin with the resin matrix in an appropriate ratio is added to a separately prepared appropriate thickness (for example, 100 to 25).
An adhesive layer 50 having an appropriate thickness (for example, 50 μm) is formed by coating and disposing it on one surface of a transparent substrate (for example, polyethylene terephthalate film) 20 having a thickness of 0 μm.

Preparation of Adhesive Layer 60

A hot melt adhesive prepared by mixing a tackifying resin in an appropriate ratio with a resin matrix is applied to a separately prepared appropriate thickness (for example, 100 to 25).
An adhesive layer 60 having an appropriate thickness (for example, 30 μm) is formed by applying and arranging it on one surface of a magnetic sheet (for example, a plastic film) 40 having a thickness of 0 μm.

Application to the adhesive layer 50

The microcapsule dispersion having the adjusted concentration is applied on the surface of the adhesive layer 50 disposed on one surface of the transparent substrate 20 so as to have an appropriate thickness (for example, 150 μm), and dried and solidified. The microcapsule layer
It is assumed to be 30 .

Arrangement of Magnetic Sheet 40

On the surface of the microcapsule layer 30 disposed on the transparent base material 20 via the adhesive layer 50 , the magnetic sheet 40 is disposed via the adhesive layer 60 (the resulting product is referred to as a “laminate”). .

The laminate is heated to an appropriate temperature (for example, 90 ° C. to 120 ° C.) so as not to break the magnetic layer of the magnetic sheet 40 in order to sufficiently melt the adhesive of the adhesive layers 50 and 60 .
Transparent substrate 20 , microcapsule layer 30, and magnetic sheet 40
Are joined to each other (the resultant is called a “joined body”).

Commercialization

The joined body is cut into an appropriate size to obtain the visible display device 10 according to the present invention.

(Operation of Embodiment)

In addition, the operation of one embodiment of the visible display device according to the present invention will be described in detail with reference to FIGS.

In the visible display device 10 according to the present invention, the microcapsule layer 30 formed by dispersing the microcapsules 32 in the binder 31 is made up of the transparent base material 20 and the magnetic sheet 40 via the adhesive layers 50 and 60. (I)
Microcapsules can be prevented from being stacked in contact with each other, and (ii) mechanical strength can be improved by preventing insufficient bonding force between microcapsules, and (ii)
i) The manufacturing process can be simplified, and (iv) the appearance can be improved by avoiding the occurrence of steps at the peripheral portion.

[0072]

As is apparent from the above description, the visible display device according to the present invention contains magnetic flakes together with oil as described in the section of "Means for Solving the Problems", so that the visible A microcapsule layer that functions as a visible display area is formed by dispersing a plurality of microcapsules that change the direction of reflection of incident light in a binder disposed on the surface of the transparent substrate, and forms a microcapsule layer on the surface of the microcapsule layer. On the other hand, a visible display device provided with a magnetic sheet for generating a magnetic field for changing the orientation direction of the magnetic flakes contained in the microcapsules of the microcapsule layer, The binder is formed of a water-soluble resin, and the microcapsule layer is provided on the transparent substrate and the magnetic sheet via an adhesive layer, respectively. Since they are joined, they have the effect of avoiding (i) the microcapsules being in contact with each other and being laminated, and thus (ii) preventing the joining force between the microcapsules from being insufficient, thereby increasing the mechanical strength. It has the effect of being able to improve, and (iii) has the effect of simplifying the manufacturing process, and (iv) has the effect of improving the aesthetics by avoiding the occurrence of steps at the peripheral portion.

[Brief description of the drawings]

FIG. 1 is a partial sectional perspective view showing an embodiment of a visible display device according to the present invention.

FIG. 2 is a sectional view showing an enlarged part of the embodiment shown in FIG. 1;

FIG. 3A is a flowchart showing an example of a manufacturing procedure of the embodiment shown in FIG. 1;

FIG. 3B is a flowchart showing an example of a manufacturing procedure of the embodiment shown in FIG. 1;

FIG. 4 is a partial cross-sectional perspective view showing a conventional example.

[Explanation of Signs] 10 ... Visible display device 20 ... Transparent substrate 30・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Microcapsule layer 31 ・ ・ ・ ・ ・ Binder 32 ・ ・ ・ ・ ・ ・ ・ ・ ・... Microcapsules 33 Oil 34 Magnetic flakes 40・ ・ ・ ・ ・ ・ Magnetic sheets 50 , 60・ ・ ・ ・ ・ ・ Adhesive layer

Claims (1)

(57) [Claims] 1. A method for dispersing a plurality of microcapsules containing magnetic flakes together with oil and changing a reflection direction of visible incident light according to an orientation direction in a binder disposed on a surface of a transparent substrate. A magnetic sheet that generates a magnetic field for forming a microcapsule layer that functions as a visible display area and changing the orientation direction of the magnetic flakes contained in the microcapsules of the microcapsule layer with respect to the surface of the microcapsule layer In the visible display device arranged, the binder of the microcapsule layer is formed of a water-soluble resin, and the microcapsule layer is bonded to the transparent substrate and the magnetic sheet via the adhesive layers ( 50 , 60 ), respectively. A visible display device comprising: