JP2016017308A - Blind sheet for privacy protection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blind sheet for privacy protection which can be visually recognized from one surface but cannot be visually recognized from the other surface.SOLUTION: A blind sheet 11 includes a resin layer 13 that has first and second planes 21 and 22, and an optically transparent spherical body 12 that passes through the resin layer 13. An average protrusion distance of the spherical body 12 from the first plane 21 is shorter than an average protrusion distance from the second plane 22. The resin includes a pigment.SELECTED DRAWING: Figure 1

Description

  The present invention is a privacy-protecting blindfold sheet.

  Conventionally, from the viewpoint of privacy protection, a blindfold film or a special curtain, etc., can be attached to the indoor window or near the window, which makes it difficult to see the indoor situation from the outside and allows the outdoor situation to be seen from the indoor. .

  However, it is difficult to attach the blindfold film, and it is often colored in a dark color, so that sufficient lighting cannot be obtained, so that the room becomes dark. The curtain is easy to install, but at night, the interior is brightened by illumination, so the interior may be visible from the outside.

  Therefore, it is excellent in privacy protection, it is difficult to see the indoor situation from the outside, and a material that can see the outdoor situation from the inside, that is, a new material that can be seen from one side but cannot be seen from the other side. Development is required.

  An object of the present invention is to provide a blindfold sheet in which one side of the sheet can be visually recognized from the other side, but one side of the sheet cannot be visually recognized from the other side.

  Means for solving the above problems are as follows <1> to <3>.

<1> having a resin layer having a first plane and a second plane, and a plurality of light-transmitting spherical bodies penetrating the resin layer;
The average protrusion distance of the spherical body from the first plane is shorter than the average protrusion distance from the second plane,
The blindfold sheet, wherein the resin contains a pigment.

  <2> The blindfold sheet according to <1>, wherein the spherical body has a refractive index in the range of 1.30 to 2.30.

  <3> When the average diameter of the spherical body is 100%, the average protruding distance of the spherical body from the first plane is 1 to 10%, and the average protruding distance of the spherical body from the second plane is 40. The blindfold sheet according to <1> or <2>, which is ˜70%.

It is an enlarged view of a sectional view showing an embodiment of the present invention. It is an enlarged view of a sectional view showing an embodiment of the present invention. It is an enlarged view of a sectional view showing one embodiment of the present invention, and is a schematic diagram of a positional relationship between a resin layer and a spherical body. It is an enlarged view at the time of seeing the 3rd surface (23) of one embodiment of the present invention from right above. It is an enlarged view when the 4th surface (24) of one embodiment of the present invention is seen from right above.

  Hereinafter, preferred embodiments of the blindfold sheet of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the main structure of the blindfold sheet (11) according to the embodiment of the present invention includes a resin layer (13) and a plurality of light-transmitting spherical bodies (12) that penetrate the resin layer (13). ).

  As shown in FIG. 2, the blindfold sheet (11) of the embodiment of the present invention penetrates the resin layer (13) having the first plane (21) and the second plane (22), and the resin layer (13). A plurality of light-transmitting spheres (12). Moreover, the blindfold sheet (11) of the embodiment of the present invention has a third surface (23) and a fourth surface (24). The third surface (23) is constituted by a part of the second plane (22) of the resin layer (13) and a part of the surface of the spherical body (12). The fourth surface (24) is constituted by a part of the first plane (21) of the resin layer (13) and a part of the surface of the spherical body (12).

  Let R be the average protrusion distance of the portion of the third surface (23) where the spherical body (12) protrudes most from the second plane (22) of the resin layer (13). Moreover, let the average protrusion distance of the part which the spherical body (12) protrudes most from the 1st plane (21) of the resin layer (13) in the 4th surface (24) side be L. The average protrusion distance L is shorter than the average protrusion distance R. The average protrusion distances L and R of the spherical body (12) are obtained by observing the cross section of the blindfold sheet with a microscope, measuring the distance that protrudes most from each plane of the 50 spherical bodies, and calculating the average protrusion distance by calculation. It was.

  The preferable range of the average protrusion distance L is preferably 1 to 10%, more preferably 1 to 5%. Within this range, the state of the third surface (23) side can be recognized from the fourth surface (24) side, and the state of the fourth surface (24) side from the third surface (23) side can be recognized. I can't see the situation. Moreover, the preferable range of the average protrusion distance R is 40 to 70% when the diameter of the spherical body (12) is 100%. Within this range, the spherical body (12) is firmly held by the resin layer (13).

  When the average protrusion distance R and the average protrusion distance L are in the above ranges, most of the light incident from the third surface (23) passes through the spherical body (12). Furthermore, most of the light incident from the fourth surface (24) is reflected or absorbed by the first plane (21) of the resin layer (13), and a part of the light passes through the spherical body (12). Therefore, the state of the fourth surface (24) side cannot be recognized from the third surface (23) side, and the state of the third surface (23) side can be recognized from the fourth surface (24) side. it can.

  Various resins can be used for the resin layer (13), and a thermoplastic resin can be preferably used. For example, polyethylene resin, polypropylene resin, polyester resin, polyamide resin, poly (meth) acrylic resin, polystyrene Examples thereof include resins, polycarbonates, polylactic acid, ethylene vinyl alcohol copolymers, and polyurethane resins.

  Furthermore, a known additive such as a plasticizer, a surfactant, a solvent and the like can be added to the resin as necessary.

  The resin layer (13) contains a pigment such as a white pigment or a black pigment in order to impart light shielding properties. As the white pigment, conventionally known materials can be used, for example, titanium oxide, alumina, barium sulfate, barium carbonate, zinc oxide, barium titanate, strontium titanate, calcium carbonate, magnesium carbonate, forsterite, and wollastonite. Etc. As the black pigment, conventionally known materials can be used, and examples thereof include carbon black, aniline black, titanium black, inorganic pigment hematite, and perylene black.

  The spherical bodies are arranged in a single layer and close to close packing with respect to the second plane (22) of the resin layer (13). Although the diameter of a spherical body (12) does not have a restriction | limiting in particular, it is the range of 5-1000 micrometers, Preferably it is the range of 10-500 micrometers. If the diameter is 5 μm or more, it is preferable that the spherical bodies are not easily aggregated, so that the arrangement in a single layer is easy. Moreover, if the diameter is 1000 μm or less, it is preferable that the spherical body does not easily fall off from the blindfold sheet. The diameter of the spherical body (12) can be measured with a microscope.

  There are no particular restrictions on the type of spherical body (12), but inorganic spherical bodies represented by glass beads, silica beads, transparent ceramic beads, acrylic resin beads, polystyrene resin beads, melamine resin beads, and urethane resin beads are typical. The resin spherical body to be used can be used suitably.

  The refractive index of the spherical body (12) is preferably in the range of 1.30 to 2.30, more preferably 1.70 to 2.10. If the refractive index is 1.30 or more, light can be collected efficiently. If the refractive index is 2.30 or less, light can be transmitted appropriately. Note that the refractive index of the spherical body can be measured by a normal refractive index measurement method such as Abbe's method.

  The spherical body (12) can be surface-treated. For example, a silane coupling agent or a fluorine-based additive is used. By performing the surface treatment, the spherical body and the resin layer can be firmly bonded.

  FIG. 3 is an enlarged view when the third surface (23) of the blindfold sheet is viewed from directly above. It is preferable that the spherical body has a substantially uniform size. As shown in FIG. 3, when the spherical bodies are approximately uniform in size and ideally arranged, the arrangement is close to fine packing, and light can be collected efficiently. In the present application, the size of the spherical body is substantially uniform. The diameter of 30 spherical bodies is measured on the observation screen of a microscope, and the coefficient of variation obtained from the average value and standard deviation is 0.5 or less. Means.

  Although there is no restriction | limiting in particular in the thickness of a blindfold sheet | seat (11), The range of 5-1000 micrometers is suitable.

  The blindfold sheet of the present invention can be produced, for example, by the following method.

  A master batch in which a resin and a pigment are uniformly kneaded and a release process paper are prepared. The resin and the master batch are uniformly kneaded with an extruder and coated on the release process paper to form a resin layer. Subsequently, the atmospheric temperature of the process is adjusted to be equal to or higher than the softening temperature of the resin layer, and a plurality of spherical bodies are uniformly and densely dispersed and adhered on the resin layer. Excessive spherical bodies that did not adhere were removed by using a brush, a gauge, or the like, or blown off with air or liquid so that the plurality of spherical bodies became a single layer. Next, a resin layer to which a plurality of spherical bodies are attached is pressed from the side on which the spherical bodies are dispersed using a nip roll, and the spherical bodies are pushed into the resin layer, and the average of the spherical bodies from the resin layer is The projection distance was adjusted to produce a blindfold sheet.

  The ratio of the spherical body embedded in the resin layer can be appropriately controlled by the heating method, heating temperature, heating time, pressing method, pressing force, and pressing time.

  The release process paper that can be used in the present invention is not particularly limited, and is a surface-treated with a release agent on plastic films such as polyethylene terephthalate film and polypropylene film, and paper such as fine paper and glassine paper. Is mentioned.

  Hereinafter, the content of the present invention will be specifically described with reference to examples. However, the present invention is not limited to the following examples.

Example 1
30 parts by mass of pigment A was kneaded with 100 parts by mass of resin A, and the pigment was uniformly dispersed to prepare a master batch. Next, 10 parts by mass of the master batch was uniformly kneaded with an extruder with respect to 100 parts by mass of the resin A, and applied to the release process paper to form a resin layer. The atmospheric temperature of the process was adjusted to 105 ° C., and then a plurality of spherical bodies A were uniformly dispersed and adhered to the resin layer. Excess spherical bodies that did not adhere to the resin layer were removed by blowing off with air. Next, pressure was applied from the side where the spherical body A was dispersed using a nip roll, the spherical body was embedded in the resin layer, the release process paper was peeled off, and a blindfold sheet was produced.
Here, the first plane in the resin layer is the surface in contact with the release process paper, and the second plane is the coating surface.
As a result of observing and measuring the cross section of the produced blindfold sheet with an optical microscope, the average protrusion distance L from the first plane of the spherical body was 2%, and the average protrusion distance R from the second plane was 50%.

Examples 2-8
A blindfold sheet was produced by the same manufacturing method as in Example 1, except that the resins, pigments, and spheres used in Examples 2-8 and Comparative Examples 1-2 were changed as shown in Table 1. The average protrusion distance L from the first plane and the average protrusion distance R from the second plane of the spherical body were adjusted by changing the load of the nip roll. Similarly to Example 1, the average protrusion distance L from the first plane and the average protrusion distance R from the second plane of the spherical body were measured by observing the cross section of the produced blindfold sheet with an optical microscope.

Both surfaces of the blindfold sheets prepared in Examples 1 to 8 and Comparative Examples 1 and 2 were visually observed, and the performance was evaluated with ○, Δ, and ×.
A: The other surface side was visible from one surface, and the one surface was not visually recognized from the other surface. Good performance as a blindfold sheet.
(Triangle | delta): The other surface side was visually recognizable from one surface, and one surface was not visually recognizable clearly from the other surface. Alternatively, neither the other surface side from one surface nor the one surface side from the other surface side was clearly visible.
X: Not visible at all from one side or the other side. Or it was visible from one side and the other side. The performance as a blindfold sheet is poor.

Abbreviations in Table 1 are as follows.
Resin A: Excellen FXCX1001 (manufactured by Sumitomo Chemical Co., Ltd., polyethylene)
Resin B: Espolex SB2400 (Sumitomo Chemical Co., Ltd., polystyrene)
Resin C: Eval E105B (Kuraray Co., Ltd., ethylene vinyl alcohol copolymer)
Pigment A: Titanium oxide pigment B: Carbon black sphere A: U-052FX (manufactured by Union Co., Ltd., refractive index 2.2, average particle size 35 μm)
Spherical B: ULGB-27AC (Union Corporation, refractive index 1.9, average particle size 65 μm)

  According to the present invention, there is provided a blindfold sheet that is visible from one side but cannot be seen from the other side.

DESCRIPTION OF SYMBOLS 11 ... Blindfold sheet | seat 12 ... Spherical body 13 ... Resin layer 21 ... 1st plane 22 ... 2nd plane 23 ... 3rd surface 24 ... 4th surface

Claims (3)

A resin layer having a first plane and a second plane; and a plurality of light-transmitting spherical bodies penetrating the resin layer;
The average protrusion distance of the spherical body from the first plane is shorter than the average protrusion distance from the second plane,
A blindfold sheet characterized in that the resin contains a pigment.   The blindfold sheet according to claim 1, wherein a refractive index of the spherical body is in a range of 1.30 to 2.30.   When the average diameter of the spherical body is 100%, the average protruding distance of the spherical body from the first plane is 1 to 10%, and the average protruding distance of the spherical body from the second plane is 40 to 40%. The blindfold sheet according to claim 1 or 2, wherein the blindfold sheet is 70%.

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