JP2009025621A - Display surface sheet and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet for a display surface preventing an air bubble from coming therebetween and a display even when it is tightly stuck to the display, especially a large display, and to provide its manufacturing method. <P>SOLUTION: The sheet for the display surface has an adhesive layer 20 containing rubber component, a groove 23 reaching at least from the center part to the edge is formed in the surface of the adhesive layer 20, and the surface of a part 20a having no groove 23 of the adhesive layer 20 has a mirror plane. The method of manufacturing the sheet for display surface comprises: a step of forming the adhesive layer 20 that has a mirror-like surface and contains rubber component; and a step of forming, on the surface of the adhesive layer 20, the groove 23 reaching at least from the center part to the edge by dry etching. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a display surface sheet that is removably attached to a display surface and a method for manufacturing the same.

A display surface sheet having functions such as peep prevention and surface protection may be attached to the surface of a display provided in a personal computer or a portable information terminal.
Usually, the sheet | seat for display surfaces is equipped with the adhesive layer which can be peeled again. As a releasable adhesive layer, a layer containing a rubber component having a high self-adhesive force and having a mirror-like surface is known. For example, Patent Document 1 discloses an adhesive layer provided in a peep prevention body, which includes silicone rubber and has a mirror-like surface. Patent Document 2 discloses an adhesive layer made of a rubber film laminated on a base film and having a mirror-like surface.
JP 2003-131202 A JP 2000-056694 A

However, when a conventional display surface sheet is bonded to a display, particularly a large display, air bubbles may enter between the display and the display surface sheet, which may reduce image visibility. If the display surface sheet is placed in front of the display without being in close contact with the display, bubbles are not generated. However, if the display surface sheet is not in close contact with the display, moire fringes may occur during image display.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a display surface sheet and a method for manufacturing the display surface sheet, in which air bubbles are less likely to enter between the display and a large display even when closely attached to the display. And

The present invention includes the following aspects.
[1] A surface of a portion having an adhesive layer containing a rubber component, wherein at least a groove reaching the edge from the center is formed on the surface of the adhesive layer, and no groove of the adhesive layer is formed A sheet for a display surface, characterized by having a mirror surface.
[2] The display surface sheet according to [1], which is for peeping prevention.
[3] A step of forming an adhesive layer having a mirror-like surface and containing a rubber component;
And a step of forming at least a groove reaching the edge from the central portion on the surface of the adhesive layer by dry etching.
[4] The method for producing a sheet for display surface according to [3], wherein the dry etching is reactive ion etching.

Even if the display surface sheet of the present invention is in close contact with a display, particularly a large display, bubbles are unlikely to enter the display.
According to the method for producing a display surface sheet of the present invention, it is possible to produce a display surface sheet in which air bubbles are unlikely to enter between the display and a large display.

<Display surface sheet>
One embodiment of the display surface sheet of the present invention will be described.
In FIG. 1, the sheet | seat for display surfaces of this embodiment example is shown. The display surface sheet is a rectangular peep prevention sheet 1, and is laminated on the louver layer 10, the adhesive layer 20 laminated on one surface of the louver layer 10, and the other surface of the louver layer 10. The transparent resin layer 30 is provided.

[Louvre layer]
In the louver layer 10, as shown in FIG. 2, light transmission bands 11 and light shielding bands 12 are alternately arranged in the X direction.
Each of the light transmission band 11 and the light shielding band 12 constituting the louver layer 10 has a band shape extending in the Y direction, and the width in the X direction is uniform and constant.
In the louver layer 10, the angle α1 formed between the surface of the louver layer 10 and the light shielding band 12 is approximately 90 ° (greater than 85 ° and smaller than 95 °), and preferably 90 °.

As a material constituting the light transmission band 11, a highly transparent resin is used. Specifically, a resin having high transparency such that the light transmittance when light is transmitted in the Z direction in the figure with respect to only the light transmission band 11 is 75% or more, preferably 85% or more. Material is preferred. For example, a highly transparent thermoplastic resin or thermosetting resin is used, and specific examples include cellulosic resin, polyolefin, polyester, silicone resin, polystyrene, polyvinyl chloride, acrylic resin, and polycarbonate. Of these, silicone resins are preferred, and silicone rubber is particularly preferred from the viewpoint of heat resistance.
Note that the value of “light transmittance” in this specification is D ₆₅ defined in JIS Z 8720 as a light source, and in the apparatus for measuring the intensity of inspection light emitted from the light source with a light receiving sensor, the inspection light is used. The output value of the light receiving sensor when there is no object to be measured on the optical path is set to A, the object to be measured is set on the optical path of the inspection light, and the transmitted light transmitted through the object to be measured is received by the light receiving sensor. When the output value of B is B, the light transmittance = (B / A) × 100 (unit:%).

  The width W11 in the X direction of the light transmission band 11 is preferably in the range of 50 μm to 0.3 mm, and more preferably in the range of 75 μm to 0.2 mm.

As the material constituting the light-shielding band 12, a colored resin obtained by adding a colorant such as a pigment or a dye to the resin listed above as the material of the light transmission band 11 is preferably used. The color tone of the light-shielding band 12 is not particularly limited as long as a preferable light-shielding property in the light-shielding band 12 is obtained, and can be black, red, yellow, green, blue, light blue, or the like. The color tone of the shading band 12 can be adjusted by the type and amount of the colorant. Specifically, the light-shielding property is such that only the light-shielding band 12 has a light transmittance of 40% or less, preferably 10% or less when light is transmitted in the width direction (X direction in this figure). It is preferable to have. Moreover, since the color tone of the light-shielding band 12 constitutes the color tone recognized when the louver layer 10 is viewed, it is preferable to design the color tone in consideration of decorativeness.
Specific examples of the colorant include general organic pigments or inorganic pigments such as carbon black, benkara, iron oxide, titanium oxide, yellow iron oxide, disazo yellow, and phthalocyanine blue. One colorant may be used, or two or more colorants may be used. Moreover, when not using a black pigment, it is preferable to use a white pigment together in order to obtain favorable light-shielding property.

  The width W12 in the X direction of the light shielding band 12 is preferably in the range of 5 to 50 μm, and more preferably in the range of 15 μm to 30 μm.

  In the louver layer 10, the resin material constituting the light transmission band 11 and the resin material constituting the light shielding band 12 may be the same or different. From the viewpoint of adhesiveness with the band 12, it is preferable that both are the same.

  The thickness T1 of the louver layer 10 in the Z direction is preferably about 0.1 to 2.5 mm, and more preferably about 0.14 to 0.6 mm.

[Adhesive layer]
The adhesive layer 20 is a layer for adhering the peeping prevention sheet 1 to the display, and is a layer containing a rubber component. Examples of the rubber component include silicone rubber, urethane rubber, fluorine rubber, acrylic rubber, ethylene propylene rubber, acrylonitrile butadiene rubber, and the like. Among these, silicone rubber is preferable because of its excellent transparency, heat resistance, and weather resistance.

In the surface of the adhesive layer 20 in this embodiment, a large number of grooves 23 reaching from the one edge 22a to the other edge 22b are formed in parallel with the light transmission band 11 and the light shielding band 12, that is, in one direction in the Y direction. (See FIG. 3). That is, the groove 23 reaches the two parallel edges 22a and 22b from the central portion 21.
The width of the groove 23 is preferably 0.5 to 5 mm, and more preferably 1 to 3 mm. If the width of the groove 23 is 0.5 mm or more, it is easier to vent air through the groove 23, and if it is 5 mm or less, the groove 23 is difficult to be visually recognized when pasted to the display, It will be more suitable.
The depth of the groove 23 is preferably 100 to 1000 nm from the viewpoint of forming a non-adhesive part. Further, since the step is reduced and the visibility of the display is prevented from being lowered, it is preferable that the depth of the groove 23 is a depth at which the bottom does not reach the louver layer 10.

  The surface of the portion 20a where the groove 23 of the adhesive layer 20 is not formed is mirror-like. The mirror surface in the present invention means a mirror surface glossiness (glossiness at an incident angle of 60 ° in JIS Z 8741) of 120% or more. A surface having such a glossiness has high smoothness and a large contact area with the adherend.

[Transparent resin layer]
The material of the transparent resin layer 30 is preferably a material having a light transmittance of 75% or more when light is transmitted in the Z direction in the figure relative to a single transparent resin layer 30 and is 85% or more. Those are more preferred.
As a resin material constituting the transparent resin layer 30 satisfying such light transmittance, polycarbonate, polyester (for example, polyethylene terephthalate, polybutylene terephthalate, etc.), acrylic resin, polyolefin (particularly, in terms of transparency and heat resistance) , Cycloolefin polymer) and cellulosic resins are preferable, and polycarbonate and polyester are more preferable.
If the thickness of the transparent resin layer 30 in the Z direction is too thin, a sufficient protective function cannot be obtained, and the light transmittance decreases as the thickness increases, so about 0.01 to 0.5 mm is preferable. About 2 mm is more preferable.

In the peep prevention sheet 1 described above, the adhesive layer 20 includes a rubber component having a large self-adhesive force, and the surface of the portion 20a where the groove 23 of the adhesive layer 20 is not formed is mirror-like. Large contact area when bonded to a display. Therefore, the peep prevention sheet 1 can be attached to the display by the adhesive layer 20. Moreover, since the adhesive layer 20 has a large cohesive force and there is no transfer of the components constituting the adhesive layer 20 to the display, it can be peeled off again.
Moreover, since the groove | channel 23 is formed in the surface of the adhesion layer 20, the sheet | seat 1 for peeping prevention can be stuck and adhered to a display, drawing air through the groove | channel 23. FIG. Alternatively, even if air bubbles enter after bonding, the air can be easily removed through the groove 23.
Therefore, in the peeping prevention sheet 1 described above, even if it is brought into close contact with a display, particularly a large display, bubbles are unlikely to enter the display.

<Method for producing sheet for display surface>
The manufacturing method of the display surface sheet of the present invention will be described by taking the manufacturing method of the peeping prevention sheet 1 as an example.
The manufacturing method of the present embodiment includes a first step for producing the louver layer 10, a second step for forming the adhesive layer 20 in which no groove is formed, an adhesive layer 20 and a transparent layer on the louver layer 10. This is a method including a third step of laminating the resin layer 30 and a fourth step of forming the groove 23 on the surface of the adhesive layer 20.

[First step]
The louver layer 10 can be manufactured as follows. First, a plurality of first sheets made of the constituent material of the light transmission band 11 and having the thickness W11, and a plurality of second sheets made of the constituent material of the light shielding band 12 and having the thickness W12, Are alternately laminated, and heated and pressed to form a block body in which the plurality of sheets are integrated.
Next, the louver layer 10 can be obtained by slicing the block body along a cut surface perpendicular to the sheet surface. The thickness (slice width) when slicing is T1.

[Second step]
As a method for forming the adhesive layer 20, a method in which one surface of the adhesive layer 20 becomes a mirror surface is adopted. For example, a method in which a liquid rubber is applied to a process sheet having a mirror surface and cured, and the surface is A method of applying a solid rubber solution to a mirror-like process sheet and drying it, a method of applying the solid rubber to a process sheet having a mirror-like surface and passing it through a calender roll are applied.
As a material for the process sheet, polyethylene terephthalate is preferable because a mirror-like sheet can be easily obtained.

[Third step]
The method for laminating the louver layer 10 and the transparent resin layer 30 is not particularly limited, and a known method can be appropriately employed. For example, a method of applying an adhesive on the surface of the louver layer 10 and bonding the transparent resin layer 30 and then curing the adhesive may be used. The adhesive used at this time preferably has a high light transmittance after curing. Specifically, it is preferable that the light transmittance of the adhesive layer formed after curing is 65% or more, and more preferably 80% or more.
Examples of such an adhesive having transparency include a thermosetting adhesive, a multi-component reaction adhesive, an ultraviolet curable adhesive, and the like. Specifically, an epoxy adhesive, a urethane adhesive, An acrylic adhesive, a melamine adhesive, a polyester adhesive, a silicone adhesive, and the like can be suitably used.

  Examples of the method for laminating the adhesive layer 20 on the louver layer 10 include a method using an adhesive as in the case of laminating the transparent resin layer 30 and a method of heat vulcanization adhesion.

[Fourth step]
In the fourth step, many grooves 23 along the Y direction are formed on the surface of the adhesive layer 20.
When the groove 23 is formed on the surface of the adhesive layer 20, dry etching that performs etching without using an etchant is applied.
Examples of dry etching include plasma etching, photoetching, and ion beam etching. Among these, plasma etching and photoetching are preferable because fine grooves can be easily formed.

Plasma etching may be either a method of causing radicals generated by plasma to collide with an object to be etched or a method of causing ions generated by plasma to collide with an object to be etched (reactive ion etching method). The reactive ion etching method is preferable because it can be etched precisely.
In the reactive ion etching method, for example, the etching rate of gold is about 15 nm / min, and the etching rate of polymer is 50 to 300 nm / min.

Various etching conditions when the reactive ion etching method is applied are appropriately set according to the size and thickness of the adhesive layer 20 and the type of the etching apparatus.
Examples of the gas (etching gas) that is a source of ions include argon gas, chlorine-based gas (BCl ₃ , Cl ₂ , CCl _4, etc.), fluorine-based gas (CF ₄ , CHF ₃ , C ₂ F ₆ , SF). ₆ ) and the like. Argon gas is preferred because of its versatility. When argon gas is used, Ar ⁺ generated by plasma collides with the adhesive layer 20.

When SPC-100 manufactured by Hitachi High-Technologies Corporation is used as the plasma etching apparatus and argon gas is used as the etching gas, the argon gas supply rate is preferably ³ to 7 cm ³ / min. The degree of vacuum is preferably 10-30 Pa.

  As the photoetching, for example, there is a method of forming the groove 23 by etching by irradiation with ultraviolet rays. As the ultraviolet rays, light using harmonics such as an excimer laser or a YAG laser can be used.

In dry etching, masking is disposed on the surface of the adhesive layer 20 where the groove 23 is not formed.
As the masking, for example, a resist agent, a dry film, a masking tape in which slits are formed on a removable fine adhesive tape by a cutting plotter, a laser, or the like is used. These thicknesses are preferably thicker than the adhesive layer 20.
Further, as masking, a masking plate in which slits are formed by performing etching, laser drilling, punching, machining, or the like on a metal plate such as stainless steel can also be used. Since such a masking plate can be used repeatedly, it is suitable for forming the same groove continuously.
In the case of performing photoetching, the masking must be made of a light shielding material.

  In the manufacturing method described above, since the groove 23 is formed by dry etching on the surface of the mirror-like adhesive layer 20, it can be attached to the display, and even if it is in close contact with the display, bubbles are unlikely to enter the display. The peep prevention sheet 1 can be manufactured.

By the way, generally, wet etching and blast etching are known as etching methods, and the groove 23 can be formed even if these etching methods are applied. However, according to wet etching using an aqueous alkali solution, workability is reduced, and a process for discarding the aqueous alkali solution must be performed, which is complicated. In addition, according to blast etching, since the abrasive used for blasting or scraped material easily adheres to the surface of the adhesive layer 20, it has a drawback of lowering the specularity and reducing the adhesiveness. .
In contrast to these methods, dry etching does not handle an alkaline aqueous solution, so that the workability is high. Further, since the scraped material has a small mass and can be easily discharged from the etching chamber by vacuum evacuation or the like, it is difficult to adhere to the surface of the adhesive layer 20. Therefore, the mirror surface fall of the sticking layer 20 can be prevented, and a sticking fall can be prevented.

  The groove 23 can also be formed by applying or printing a solution containing a rubber component so that the groove 23 is formed. However, with existing printing methods, it is not easy to apply or print a solution containing a rubber component (particularly silicone rubber) so as to form fine grooves 23 that are less visible and suitable for display surfaces. On the other hand, according to the manufacturing method of the present invention in which the adhesive layer 20 is formed and then dry-etched, it is possible to easily form the fine groove 23 that is difficult to be visually recognized.

  In addition, if a groove is formed, a method of scratching with a knife or the like is also conceivable. However, since the adhesive layer in the present invention contains a rubber component and is highly elastic, the knife does not enter. It is difficult to scratch.

Note that the present invention is not limited to the above embodiment. The pattern of the groove 23 of the adhesive layer 20 in the above embodiment is formed in one direction in the Y direction, but in the present invention, at least a groove reaching the edge from the central portion 21 is formed. Any pattern can be used. For example, the groove 23 reaches the both edges 22a and 22b in the Y direction, but may reach only the one edge 22a.
As the groove pattern, for example, a pattern in which a large number of grooves 24 are formed in one direction in the X direction (see FIG. 4), a groove 23 formed in the Y direction, and a groove 24 formed in the X direction are in a lattice shape. (See FIG. 5), a pattern in which grooves 25 and 26 formed at ± 45 degrees with respect to the X direction and the Y direction intersect in a lattice pattern (see FIG. 6), and edges 22a and 22b on all sides from the center 27 , 22c, and 22d (see FIG. 7) in which a large number of linear grooves 28 are formed.

  Moreover, although the sheet | seat for display surfaces of the said embodiment example was a peeping prevention sheet | seat provided with the louver layer 10, a sheet | seat provided with layers other than a louver layer may be sufficient. For example, it may be a surface protective sheet in which an adhesive layer is laminated on a protective layer having excellent scratch resistance, or an antireflection sheet in which an adhesive layer is laminated on an antireflection layer having an antireflection function.

First, a transparent silicone rubber sheet having a thickness of 120 μm was formed using a highly transparent silicone compound SE-1188U (trade name, manufactured by Toray Dow Corning Silicone Co., Ltd.). Further, carbon black was added to silicone compound KE-981U (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) and uniformly kneaded to form a colored silicone rubber sheet having a thickness of 15 μm.
Next, the colored silicone rubber sheet was sheeted on a transparent silicone rubber sheet, and these were alternately laminated to prepare a block body.
Next, the block body is heated, cured and cured, and this is sliced on a plane perpendicular to the laminating direction of the transparent silicone rubber sheet and the colored silicone rubber sheet, so that the transparent silicone rubber sheet and the colored silicone rubber sheet are parallel to each other and alternately. A louver layer having a thickness of 2.4 mm was prepared. This louver layer is a silicone rubber film having a visible parallel light transmittance of 80% or more and a visible angle of 90 °.

  Next, a silicone adhesive comprising liquid silicone rubber KE-1934A / B (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) and primer AP-1 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to one surface of the louver layer. The adhesive layer was formed by applying to a thickness of about 30 μm using a screen printer. A transparent resin layer made of polycarbonate having a thickness of 0.2 mm was integrally bonded to this adhesive layer. The adhesive strength (JIS K 6256) between the louver layer and the transparent resin layer was 15 N / 25 mm.

  Next, a liquid silicone rubber KE-1934A / B (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied to a mirror-finished polyethylene terephthalate (hereinafter referred to as PET) to a thickness of about 30 μm by a screen printer, An adhesive layer was formed. This adhesive layer was heat vulcanized and bonded to the other surface of the louver layer.

Further, a YAG laser was used on a stainless steel plate having a thickness of 0.1 mm to form slits 41 having a width of 2 mm, a pitch of 20 mm, and a length of 290 mm as shown in FIG.
Next, the PET film laminated on the adhesive layer was peeled off and inserted into an etching chamber of a plasma etching apparatus (SPC-100 manufactured by Hitachi Hike Technologies). At that time, the masking plate was disposed on the adhesive layer. Then, the adhesive layer was plasma etched for 2 minutes under the conditions of a degree of vacuum of 20 Pa in the etching chamber, an argon gas supply amount of 5 cm ³ / min, and an output of 600 W.
Thereafter, the masking plate is removed from the obtained adhesive layer and cut into an outer size of 340 mm × 270 mm, and a 17-inch liquid crystal in which grooves 23 (see FIG. 3) along the Y direction are formed on the surface of the adhesive layer. A peep prevention sheet for display was obtained.
When this peep prevention sheet is bonded to the cleaned liquid crystal display so that the adhesive layer is in close contact, it is difficult for bubbles to enter the liquid crystal display, and even if bubbles enter, they should be discharged through the groove. It was easy to remove.

It is sectional drawing which shows the sheet | seat for peeping prevention which is one example of the sheet | seat for display surfaces of this invention. It is a perspective view which shows the louver layer which comprises the sheet | seat for peeping prevention shown in FIG. It is a top view which shows the pattern of the groove | channel in the sticking layer which comprises the sheet | seat for peep prevention shown in FIG. It is a top view which shows the other example of the pattern of a groove | channel. It is a top view which shows the other example of the pattern of a groove | channel. It is a top view which shows the other example of the pattern of a groove | channel. It is a top view which shows the other example of the pattern of a groove | channel. It is a top view which shows the masking plate used in the Example.

Explanation of symbols

1 Peep prevention sheet (display surface sheet)
DESCRIPTION OF SYMBOLS 10 Louver layer 11 Light transmission band 12 Light shielding band 20 Adhesion layer 20a The part 21 in which the groove is not formed Center part 22a, 22b, 22c, 22d Edge 23, 24, 25, 26, 28 Groove 30 Transparent resin layer 40 Masking plate

Claims (4)

  It has an adhesive layer containing a rubber component, and at least a groove reaching the edge from the center is formed on the surface of the adhesive layer, and the surface of the part where the groove of the adhesive layer is not formed is mirror-like A sheet for a display surface, characterized in that   The display surface sheet according to claim 1, wherein the display surface sheet is used for preventing peeping. Forming a sticking layer having a mirror-like surface and containing a rubber component;
And a step of forming at least a groove reaching the edge from the central portion on the surface of the adhesive layer by dry etching. The method for producing a display surface sheet according to claim 3, wherein the dry etching is reactive ion etching.

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