JP2007011126A - Optical functional film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical functional film which has high strength and high flexibility and is made thin. <P>SOLUTION: The optical functional film 10 has a pair of electrode films 12A and 12B which are translucent and flexible, and further has resin 14 which is translucent and flexible, so the flexibility is improved. Then a plurality of translucent capsules 16 containing TiO<SB>2</SB>particles and toluene 24 are interposed between the pair of electrode films 12A and 12B, which therefore support each other because of the translucent capsules 16, so that the strength of the optical functional film 10 is also improved. Additionally, the translucent capsules 10 are spread in one layer, so the optical functional film is made thin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical functional film whose light transmittance is changed by application of a voltage.

An optical functional module whose light transmittance is changed by applying a voltage is disclosed in, for example, Patent Document 1 below. The optical functional module described in this publication is configured such that an electrically insulating medium having fluidity is accommodated between a pair of facing transparent substrates, and the electrically insulating medium includes electric field alignment particles. ing. A transparent conductive layer is formed inside each transparent substrate, and a voltage can be applied between the transparent conductive layers.
JP-A-8-135344

  In the conventional optical functional module described above, when the transparent substrate is simply thinned in order to reduce the thickness, it is not possible to secure sufficient strength to accommodate the electrically insulating medium having fluidity. Therefore, it is conceivable to employ a high-strength material such as a glass material or an acrylic material for the material of the transparent substrate. However, when the transparent substrate has a high strength, the flexibility is extremely small, and as a result, the applications that can be used are greatly limited. Therefore, a thin film-like optical functional module (that is, an optical functional film) that can be applied to various uses and is not easily damaged and excellent in flexibility is desired.

  Accordingly, the present invention has been made to solve the above-described problems, and an object thereof is to provide an optical functional film having high strength and high flexibility and being thinned. .

  An optical functional film according to the present invention includes a pair of translucent and flexible electrode films, a translucent and flexible resin filled between the pair of electrode films, and an electrode film. And a plurality of light-transmitting capsules containing solid particles having an electric field alignment effect or an electric field orientation effect and an electrically insulating medium. .

  Since this optical functional film includes a pair of electrode films having translucency and flexibility and also includes a resin having translucency and flexibility, the flexibility is improved. Yes. And, between the pair of electrode films, a plurality of translucent capsules containing solid particles and an electrically insulating medium are interposed, and the electrode films support each other by this translucent capsule. In this optical functional film, the strength is also improved. In addition, since these translucent capsules are spread so as to become one layer, the optical functional film is also made thinner.

  Moreover, it is preferable that each electrode film is a translucent resin film in which a translucent conductive film is provided on the opposite surface side. When the electrode film has such a configuration, an electrode film having translucency and flexibility is actually obtained.

  Furthermore, the translucent capsule is preferably made of a translucent resin, and the solid particles accommodated in the translucent capsule are preferably substantially spherical.

  According to the present invention, an optical functional film having high strength and high flexibility and having a reduced thickness is provided.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments that are considered to be the best for carrying out an optical functional film according to the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected about the same or equivalent element, and the description is abbreviate | omitted when description overlaps.

(First embodiment)
As shown in FIG. 1, the optical functional film 10 according to the first embodiment includes a pair of electrode films 12A and 12B facing each other, a resin 14 filled between these electrode films 12A and 12B, and a plurality of films. The capsule 16 is provided.

  Each of the pair of electrode films 12A and 12B includes a PET film (translucent resin film) 18A and 18B and an ITO film (translucent conductive film) 20A and 20B. More specifically, the electrode films 12A and 12B are PET films 18A and 18B in which ITO films 20A and 20B are provided on the opposing surfaces 12a side. The PET films 18A and 18B and the ITO films 20A and 20B are both transparent and have high translucency. Therefore, the electrode films 12A and 12B composed of the PET films 18A and 18B and the ITO films 20A and 20B also have translucency. Furthermore, since the thickness of electrode film 12A, 12B is 125 micrometers, it has enough flexibility. In addition, you may change suitably the thickness of electrode film 12A, 12B in the range of 100 micrometers-1000 micrometers.

  The resin 14 is interposed between the electrode films 12A and 12B and is in contact with the ITO films 20A and 20B. The resin 14 is made of a silicone resin having translucency and flexibility. The thickness of the resin 14 is defined to some extent by the distance between the electrode films 12A and 12B, and is 60 μm. Note that the thickness of the resin 14 may be appropriately changed within a range of 10 μm to 500 μm.

  A plurality of capsules (translucent capsules) 16 are contained in the resin 14, and movement of each capsule 16 is restricted to some extent by the resin 14. Each capsule 16 functions as a spacer that keeps the separation distance between the electrode films 12A and 12B at a certain length, and the ITO films 20A and 20B of the electrode films 12A and 12B come into contact with each other to cause a short circuit. While suppressing, the structural strength of the facing direction of electrode film 12A, 12B is strengthened. Each capsule 16 is made of gelatin (translucent resin) and has translucency. Each capsule 16 has a spherical shape with a diameter of 50 μm. And each capsule 16 is spread | arranged in one layer between electrode film 12A, 12B so that it may not pile up mutually. Since the thickness of the resin 14 is larger than the diameter of the capsule 16, each capsule 16 is arranged between the electrode films 12A and 12B with the resin 14 interposed therebetween. In addition, as long as the diameter of each capsule 16 is smaller than the thickness of the resin 14, you may change suitably in the range of 1 micrometer-50 micrometers.

Each capsule 16 contains a plurality of spherical TiO ₂ particles (solid particles) 22 as solid particles having an electric field alignment effect, and toluene 24 as an electrically insulating medium. The TiO ₂ particles 22 are almost uniformly mixed in the toluene 24, and the TiO ₂ particles 22 are emulsified in the toluene 24 (hereinafter referred to as an emulsion state). The diameter of the TiO ₂ particles 22 is selected from a range of 0.1 nm to 100 nm, for example.

  Next, a procedure for producing the optical functional film 10 having the above configuration will be described with reference to FIG.

First, a predetermined amount of TiO ₂ particles 22 and toluene 24 are weighed (S1), and these are stirred with a stirrer to obtain TiO ₂ particles 22 and toluene 24 in an emulsion state (S2). Then, a predetermined amount (for example, 0.05 w%) of a predetermined surfactant is added to the TiO ₂ particles 22 and toluene 24 in the emulsion state, and then stirred further to adjust the zeta potential (S3). Thereafter, capsule processing is performed in which the TiO ₂ particles 22 and toluene 24 in an emulsion state are accommodated in the capsule 16 (S4).

Capsule 16 containing TiO ₂ particles 22 and toluene 24 is mixed with resin 14 (S5), and the mixture is printed on one electrode film 12A prepared in advance (S6). Then, the other electrode film 12B is bonded to the electrode film 12A on which the mixture is printed and pressed (S7). Finally, by drying the pair of electrode films 12A and 12B bonded together through the mixture (S8), the production of the optical functional film 10 is completed.

  In addition, you may perform the lamination process which covers the polyethylene film for the optical functional film 10 whole suitably.

  Hereinafter, the aspect which uses the optical functional film 10 mentioned above is demonstrated.

  When the optical functional film 10 is used, for example, it is attached to a covering (for example, printed document, glass plate, etc.) 26 from the side of one electrode film 12B (see FIG. 1). Then, a voltage is applied between the pair of electrode films 12A and 12B by the circuit 30 shown in FIG. In FIG. 3, reference numeral 32 denotes a DC power source, reference numeral 34 denotes a switch, reference numeral 36 denotes a pilot lamp, reference numeral 38 denotes a DC-DC converter, and reference numeral 40 denotes a variable resistor.

When the switch 34 of the circuit 30 is turned on and a voltage is applied between the electrode films 12A and 12B, the electric field generated between the electrode films 12A and 12B causes the TiO ₂ particles 22 in the capsule 16 to appear as shown in FIG. Dielectric polarization occurs to arrange in the electric field direction (that is, the thickness direction of the optical functional film 10).

  As a result, the light P reflected in the capsule 16 in the emulsion state passes through the capsule 16. That is, the translucency of the optical functional film 10 that was extremely low before the voltage application is improved by the voltage application.

Since the sequence of the TiO ₂ particles 22 becomes higher as the applied voltage increases, it becomes possible to improve light transmission state of the optical functional film 10 with increasing the applied voltage.

When the application of voltage to the optical functional film 10 is stopped by turning off the switch 34, the arrangement of the TiO ₂ particles 22 in the capsule 16 collapses, and the translucent state of the optical functional film 10 returns to the original extremely low state. Return.

  That is, according to this optical functional film 10, by applying a voltage between the electrode films 12A and 12B and controlling the magnitude of the applied voltage, the covering 26 is appropriately visualized, and the degree of how it is seen. Can be adjusted. As an example, when the covering 26 is a glass plate, the optical functional film 10 can be used as an electrically responsive blind. In addition, it is preferable to select the electric field strength between electrode film 12A, 12B of the optical functional film 10 from the range of 0.1-10 (kV / mm).

  As described in detail above, the optical functional film 10 includes a pair of electrode films 12A and 12B having translucency and flexibility, and the resin 14 having translucency and flexibility. It has. Therefore, flexibility is improved as compared with the optical functional module in which a high-strength material such as a glass material or an acrylic material is adopted.

  The plurality of capsules 16 interposed between the pair of electrode films function as spacers, and the electrode films 12 </ b> A and 12 </ b> B support each other via the capsules 16. Therefore, the strength of the optical functional film 10 is also improved. In addition, since these capsules 16 are laid out to be a single layer, the optical functional film 10 can be made thinner as compared with the case where the capsules 16 are arranged in a plurality of layers. Thereby, the optical functional film 10 has high strength and high flexibility, and is thinned. In other words, the optical functional film 10 is thin, hardly damaged, and excellent in flexibility. It has become.

In addition, since the conventional optical functional module directly accommodates the solid particles and the electrically insulating medium between the transparent substrates, the solid particles may locally aggregate. However, in the optical functional film 10 described above, since the TiO ₂ particles 22 and the toluene 24 mixed at a predetermined ratio are accommodated in the capsule, a situation in which the TiO ₂ particles 22 are unevenly distributed is avoided. Homogenization is achieved.

(Second Embodiment)
Subsequently, an optical functional film 10A according to a second embodiment of the present invention will be described with reference to FIGS.

The configuration of the optical functional film 10A according to the second embodiment is that the TiO ₂ particles 22 of the optical functional film 10 according to the first embodiment are TiO ₂ pieces (solid particles) 22A having an electric field orientation effect. Only different. That is, the capsule 16 in the optical functional film 10A contains a plurality of flaky TiO ₂ pieces 22A in a disorderly oriented state as solid particles having an electric field orientation effect, and an electrically insulating medium As a result, toluene 24 is accommodated. Like the TiO ₂ particles 22 according to the first embodiment, the TiO ₂ pieces 22 </ _b > A are substantially uniformly mixed in the toluene 24, and the TiO ₂ pieces 22 </ _b > A are in an emulsion state in the toluene 24. The length of the TiO ₂ piece 22A is selected from a range of 0.1 nm to 100 nm, for example.

  About the aspect which uses this optical functional film 10A, it is the same as that of 1st Embodiment. That is, it is attached to the covering 26 from the one electrode film 12B side, and a voltage is applied between the pair of electrode films 12A and 12B by the circuit 30 shown in FIG.

In the optical functional film 10A, when a voltage is applied between the electrode films 12A and 12B, the electric field generated between the electrode films 12A and 12B causes the TiO ₂ pieces 22A in the capsule 16 to be formed as shown in FIG. Dielectric polarization is performed so that it is oriented so as to stand in the electric field direction (that is, the thickness direction of the optical functional film 10A).

As a result, also in the second embodiment as in the first embodiment, the light P reflected in the capsule 16 in the emulsion state passes through the capsule 16. That is, the translucency of the optical functional film 10A, which was extremely low before voltage application, is improved by voltage application. In addition, since the orientation of the TiO ₂ piece 22A increases as the applied voltage increases, the translucency of the optical functional film 10A improves as the applied voltage increases.

When the switch 34 is turned off and the application of the voltage to the optical functional film 10A is stopped, the orientation of the TiO ₂ pieces 22A in the capsule 16 is disturbed, and the translucent state of the optical functional film 10A returns to the original extremely low state. .

  In other words, the optical functional film 10A also makes the covering 26 appropriately visible by applying a voltage between the electrode films 12A and 12B and controlling the magnitude of the applied voltage, like the optical functional film 10. Or the degree of appearance can be adjusted.

  As described in detail above, the optical functional film 10A also includes a pair of electrode films 12A and 12B having translucency and flexibility, similar to the optical functional film 10, and A resin 14 having flexibility is provided. Therefore, flexibility is improved as compared with the optical functional module in which a high-strength material such as a glass material or an acrylic material is adopted. In addition, the electrode films 12A and 12B support each other by a plurality of capsules 16 interposed between the pair of electrode films. For this reason, the strength of the optical functional film 10A is also improved. In addition, since these capsules 16 are laid out to be a single layer, the optical functional film 10A can be made thinner than when the capsules 16 are arranged in a plurality of layers. As a result, the optical functional film 10A is also thin, hardly damaged, and excellent in flexibility, like the optical functional film 10.

The present invention is not limited to the above embodiment, and various modifications are possible. For example, the solid particles accommodated in the capsule 16 are not limited to spherical or flaky shapes, but may be scale-like or needle-like. The constituent material of the solid particles is not limited to TiO ₂ but can be appropriately selected from BaTiO ₃ and other dielectric materials. The electrically insulating medium accommodated in the capsule is not limited to toluene, but can be appropriately changed to diethylbenzene, silicone resin, isoparaffin, or the like. The resin interposed between the electrode films is not limited to the silicone resin, but can be appropriately changed to polyvinyl alcohol, an epoxy resin, an acrylic resin, or the like.

It is the schematic sectional drawing which showed the optical functional film which concerns on 1st Embodiment of this invention. It is the flowchart which showed the procedure which produces the optical functional film shown in FIG. It is the figure which showed the circuit utilized when using the optical functional film shown in FIG. It is the figure which showed the state which applied the voltage to the optical functional film shown in FIG. It is the schematic sectional drawing which showed the optical functional film which concerns on 2nd Embodiment of this invention. It is the figure which showed the state which applied the voltage to the optical functional film shown in FIG.

Explanation of symbols

10, 10A ... optical functional films 10,12A, 12B ... electrode film, 14 ... resin, 16 ... capsules, 18A, 18B ... PET film, 20A, 20B ... ITO film, 22 ... TiO ₂ particles, 22A ... TiO ₂ pieces 24 Toluene.

Claims (4)

A pair of electrode films having translucency and flexibility;
A translucent and flexible resin filled between the pair of electrode films;
A plurality of translucent capsules that are arranged in one layer so as to interpose the resin between the electrode films and contain solid particles having an electric field alignment effect or an electric field orientation effect and an electrically insulating medium; , Light functional film.   The optical functional film according to claim 1, wherein each of the electrode films is a translucent resin film in which a translucent conductive film is provided on the opposite surface side.   The optical functional film according to claim 1, wherein the translucent capsule is made of a translucent resin. The optical functional film as described in any one of Claims 1-3 whose shape of the said solid particle accommodated in the said translucent capsule is substantially spherical shape.

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