JP2003043934A - Optical filter and double-faced adhesive tape with tab - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical filter which can be easily fixed to a display screen and which can be easily detached even when the optical filter contains a louver film. SOLUTION: The optical filter has a film layer containing an optical film and having the top face to be observed by an observer and a back face opposite to the top face and has a removable adhesive layer disposed as fixed to the back face of the above film and to be adhered as removable to the objective face so that the optical filter is to be fixed to the objective face via the removable adhesive layer. The filter also has a flexible tab disposed as fixed to the film layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device provided with a film layer containing an optical film such as a louver film and an antireflection film, and an adhesive layer for removably fixing the film layer to an adherend. The present invention relates to a filter, which further includes a knob (tab) that facilitates the re-peeling operation. In the optical filter of the present invention, a double-sided adhesive tape with tab (also referred to as double-sided tape) having a flexible base material with a tab and a removable adhesive layer is preferably bonded to a film layer. It is made.

The optical filter of the present invention is used by being removably fixed to a surface to be adhered which is composed of a screen of a display device such as a liquid crystal display. For example, in the case where the film layer is a film including a louver layer, a so-called privacy filter or a peep that can prevent anyone other than the display user (operator) from peeping the display screen from the side. Can be used as an anti-sight filter.

[0003]

2. Description of the Related Art A liquid crystal display (also called a liquid crystal display device or a liquid crystal display device) is usually a liquid crystal display panel (hereinafter also referred to as a "liquid crystal panel") and a back surface (display surface) of the liquid crystal panel. And a light source (that is, a backlight) for illuminating from the opposite surface). The liquid crystal panel has a first and a second,
It has two polarizing plates and a liquid crystal layer sandwiched between them. The polarization axis (first polarization axis) of the first polarizing plate and the polarization axis (second polarization axis) of the second polarizing plate are arranged so as to form a predetermined angle with each other, for example, orthogonal to each other. . The backlight is, for example, a so-called edge light type backlight including a light guide plate and a light source that supplies light into the light guide plate from the side surface of the light guide plate. On the other hand, a direct type backlight in which a light source is arranged directly below the back surface of a liquid crystal panel is also used.

On the other hand, when using a liquid crystal display, an optical filter having various optical films as film layers is usually arranged on the display screen. Such an optical film is a film having an optical function and a protective effect of protecting the screen from stains. Examples of such an optical film include an antireflection film (optical film containing an antireflection film) and a louver film (optical film containing a louver layer).

For example, in normal backlight illumination,
The light transmitted through the liquid crystal panel is emitted unnecessarily also in the direction away from the front direction of the display surface (side direction). Therefore,
For example, not only the user or operator of the liquid crystal display located in the front, but also others located in the angular direction (side) away from the front can see the liquid crystal display, protecting the privacy of the user. Is difficult to do. Further, when the liquid crystal display is an in-vehicle device such as a car navigation system, the liquid crystal display may be reflected on the front window, which may hinder the driver's view.

In such a case, a plurality of minute louvers (or,
Also called a louvered element. ) Inside, that is, a louver film is incorporated to prevent unnecessary emission of light transmitted through the liquid crystal panel in the side direction, and to protect privacy and effectively prevent reflection on the front window of the liquid crystal display. It has been implemented. The louver film exhibits an effect (direction control effect) in which a plurality of louvers incorporated in the film controls the traveling direction of light passing through the louver film within a predetermined emission angle range. Therefore, unnecessary emission of the light transmitted through the liquid crystal panel in the lateral direction can be effectively prevented. Such a louver film is also called a light control film.

The construction, method of manufacture and use of louver films have been disclosed in several prior art documents. For example, U.S. Pat. No. Re. 27,617 discloses a louver film by skiving billets of alternating layers of plastic having relatively low (transparent) and relatively high (colored) optical densities. Discloses a method of manufacturing. When you clean the billet,
The colored layer provides a louvered element that collimates the light, and according to the description in that patent, this element is
It can be stretched at right angles to the surface of the louver film.

Further, in JP-A-8-224811, in order to prevent damage during handling of the louver film, a pressure-sensitive adhesive layer is arranged on at least one main surface (front surface or back surface) of the louver film. , Covering the adhesive surface of the adhesive layer with a transparent plastic film for protection. The transparent plastic film may have a peeling surface in some cases, and the peeling surface can be peeled off to expose the adhesive surface and adhere it to an appropriate adherend (apparatus panel, etc.) to obtain the desired final product. it can.

The pressure-sensitive adhesive layer used here is formed from a pressure-sensitive adhesive containing a tacky polymer. The tacky polymer is a polymer that exhibits tackiness at room temperature (about 25 ° C.). The tacky polymer can be obtained by polymerizing a monomer-containing composition which is in an adhesive (preferably transparent) state after being polymerized. JP-A-8-2248
No. 11 gazette specifically illustrates: 90 parts (parts by mass) of isooctyl acrylate, 10 parts of acrylic acid, 0.2 part of a photopolymerization initiator, and 0.1 part of light. A crosslinked tacky polymer obtained by UV polymerization of a monomer composition containing an active cross-linking agent (crosslinking agent).

As a specific example of a commercially available louver film, "Trademark: Light Control Film" manufactured by 3M Company.
Etc. can be mentioned.

On the other hand, a method is also known in which a film layer made of a transparent protective film is removably adhered and fixed to the display screen, although it is not a louver film. For example, in Japanese Patent Laid-Open No. 2000-56694,
Disclosed is a screen protective film comprising a laminate in which a rubber layer is laminated on one surface of a transparent film layer having a light transmittance of 80% or more, and the light transmittance of the laminate is 80% or more. ing. The rubber layer is a silicone rubber,
It is formed of any one rubber or a mixture of two or more rubbers selected from the group consisting of fluororubber, acrylic rubber, ethylene propylene rubber and acrylonitrile butadiene rubber. Therefore, the protective film can be adhered to the display screen and can be peeled off again. Since the transparent film layer is made of a plastic film such as polyester, it usually has higher transparency than the above-mentioned louver film. Also, ordinary plastic films do not have an antireflection function.

[0012]

As described above, a desired optical function can be provided by closely fixing the optical filter to the liquid crystal display screen.
For example, when the optical filter includes a louver layer, it is possible to effectively prevent unnecessary emission of light transmitted through the liquid crystal panel in the side direction and use it as an optical filter for privacy protection (so-called privacy filter). You can

On the other hand, such an optical filter is not fixed to the display screen permanently, but removed at a desired time.
It tends to be preferred that it can be easily re-fixed. Therefore, it is preferable to use a releasable adhesive layer to fix the optical filter to the adhered surface so that the optical filter can be easily fixed to the display screen, removed when desired, and easily re-fixed. . However, although the desired result can be obtained in many cases by doing so, the following problems to be solved remain. That is, it is relatively difficult to remove the optical filter after being brought into close contact with the display screen.

In a normal liquid crystal display of a notebook PC (personal computer), a monitor cover with a frame is used, and the liquid crystal panel is incorporated into the monitor cover so that the periphery of the liquid crystal panel is surrounded by the frame of the cover. The liquid crystal panel is fixed to a predetermined portion of the PC main body via. In such a display with a frame, a step is formed between the outer peripheral portion of the display screen and the frame, and the screen is arranged in a recessed portion surrounded by the inner periphery of the frame so that an observer can observe it. . Usually, the thickness of the optical filter is equal to or smaller than the height of such a step. On the other hand, optical filters are usually
It is fixed so that it covers the entire screen of the concave part inside the frame as much as possible. In such a case, only a small gap is formed between the inner peripheral portion of the frame and the optical filter. Therefore, when the user removes the optical filter, a fingernail or a tool with a sharp tip is inserted between the inner peripheral portion of the frame and the optical filter to remove the peeling force (peeling strength) that exceeds the peeling strength of the repeelable adhesive layer. It is necessary to peel off the optical filter by applying the necessary force).

Further, the nail can be inserted between the frame and the optical filter, and the optical filter can only be partially peeled at the initial stage of peeling. That is, normally, the entire surface of the optical filter (the entire back surface) is brought into close contact with the display screen, and in the state where it is partially peeled off as described above, most of it is still in close contact. Therefore, it is necessary to apply a larger peeling force to remove the optical filter. However, when a nail or the like is inserted between the normal-shaped optical filter and the frame, it is difficult to apply a peeling force, and removal of the optical filter tends to be difficult.

On the other hand, when there is no frame step as described above, from the outer peripheral edge of the optical filter in which the entire back surface is adhered,
Since it can be peeled off by inserting a nail or the like between the screen and the display screen, the peeling force can be applied relatively easily. However, in the case of an optical filter including a louver film, since the flexibility of the whole is relatively low, it is not possible to take a large peeling angle at the time of removal with an optical filter of a normal shape,
The force required for peeling tends to increase.

That is, it is an object of the present invention to provide an optical filter which can be easily fixed to a display screen and can be easily removed even when the optical filter contains a louver film. .

[0018]

The present invention comprises (a) a film layer comprising an optical film, the film layer having a surface observed by an observer and a back surface opposite to the surface;
An optical filter fixedly arranged on the back surface side of the film layer, provided with a re-adhesive adhesive layer capable of removably adhering to the adhered surface, and fixed to the adhered surface via the re-adhesive adhesive layer. In order to solve the above-mentioned problems, the present invention provides an optical filter, further comprising a flexible tab fixedly arranged with respect to the film layer.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION (Function) The optical filter of the present invention is a film layer containing an optical film, and is fixedly arranged on the back surface side of the film layer. Etc.) and a flexible tab fixedly arranged with respect to the film layer. Operation becomes easy.

The removable adhesive layer allows the optical filter to be easily fixed to the adhered surface and facilitates removal of the optical filter when desired. Further, since the tab has flexibility, the tab can be easily bent so that the angle between the tab and the adherend is an angle at which a peeling force can be easily applied. Therefore, by pinching the tab and removing the optical filter, the optical filter can be easily peeled off even when a relatively small gap is formed between the inner peripheral portion of the frame and the outer peripheral portion of the optical filter. Further, even when the optical filter includes an optical film having low flexibility such as a louver film, it can be easily peeled off. That is, since the optical filter can be peeled off by pinching the tab and pulling it away from the adhered surface, the peeling force is effectively applied to the optical filter, and the optical filter can be easily removed from the adhered surface.

The re-peeling adhesive layer may have a re-peeling property so that the optical filter can be peeled off without breaking the adhered surface. Such a releasable adhesive layer can be formed from a composition containing a cross-linked self-adherent polymer or a rubber-based polymer. The peel strength of the repeelable adhesive layer is preferably 90 inches (about 229 c) with respect to the polyethylene terephthalate (PET) surface.
m / min) and a peel strength in the range of 0.1 to 4.5 N / 25 mm as measured at a peel angle of 90 degrees.

The tab may be integrally bonded to the film layer, or may be integrally bonded to a base material fixedly arranged with respect to the film layer (tabbed base material). When a tabbed substrate is used, it is bonded so as not to come off the film layer during the peeling work. From such a viewpoint, the tabbed substrate is preferably arranged between the film layer and the repeelable adhesive layer. Further, in order to prevent peeling between the film layer and the base material, the base material and the film layer are bonded to each other via a bonding adhesive layer having a peel strength larger than the peel strength of the removable adhesive layer. Is good.

(Optical Filter) A preferred embodiment of the optical filter of the present invention will be described with reference to FIGS.
The illustrated optical filter (6) includes a front surface (601) viewed by an observer and a back surface (60) facing the front surface (601).
2) and a film layer (60), which is fixedly disposed on the back surface (602) side of the film layer and removably adheres to the adherend surface (not shown in FIGS. 1 and 2). No)) and

In the illustrated example, a double-sided tape (100) with a tab (knob portion) as shown in FIG. 3 is joined to the film layer (60) to form a tabbed substrate (1) and a re-peeling adhesive. The layer (2) is incorporated in the optical filter (6). The optical filter (6) is attached to the adhered surface, that is, the surface of the display panel (79) of the display device (7) (display screen (70)) via the removable adhesive layer (2) of the double-sided tape with tab (100). ) Fixed.

The illustrated display device (7) comprises a frame (71) surrounding a display screen (70).
Examples of the display device having such a configuration include a monitor part of a notebook PC and a mobile terminal such as a PDA. In such a display device, the film layer (6
0) is usually formed of an optical film such as an antireflection film or a louver film. The details of the film layer and the optical film will be described later.

As shown, double-sided tape with tab (10
0), that is, the tabbed substrate (1) is a film layer (6
0) is partially arranged in the vicinity of the outer peripheral edge of the back surface.
The tab (10) (tab portion of the substrate (1)) extends outward from the outer periphery of the film layer (60). That is, when the optical filter is fixed to the adherend, the tab (1
0) extends outward from the covered area (covered portion) of the adherend surface (display screen (70)) covered by the film layer (60). (See Figure 2). Therefore, since the optical filter (60) can be peeled off by pinching and pulling up the tab (10), a peeling force can be effectively applied, and the optical filter (6) can be attached to each of the joined tabbed substrates (1). ) Can be easily removed from the adherend. In addition, since the re-peelable adhesive layer is partially disposed in the vicinity of the outer peripheral edge of the back surface of the film layer, the re-peelable adhesive layer can be peeled off with a light force as compared with the case where the film layer is entirely adhered to the adherend surface. The details of the double-sided tape with tab will be described later.

The tabbed substrate (1) is usually formed from a transparent material. The transparency of the substrate is usually 80% or more, preferably 85% or more, and particularly preferably 90% or more, as defined by the light transmittance. In addition, the "light transmittance" in this specification means the total light transmittance measured using the light of 550 nm using the spectrophotometer or the color meter which also has the function of a photometer. Further, since the base material needs to have flexibility, it is usually formed from a polymer sheet. As the polymer, for example, polyester (PET, PEN, etc.), acrylic polymer, vinyl chloride polymer, polyurethane or the like can be used.

Both the bonding adhesive layer and the removable adhesive layer are
It is usually formed from a transparent adhesive. Therefore, as shown in the drawing, even if the film layer (60) and the tabbed substrate (1) overlap each other to cover the display screen, the screen can be visually recognized well. The portion of the tab that does not overlap the film layer (60) does not need to be transparent, and may be colored in a desired color and opaque. When coloring the tab part,
It is preferable to impart the same color and texture (appearance) as the components (for example, the frame) arranged around the display screen. This makes the tabs inconspicuous and does not impair the appearance around the display screen when the optical filter is fixed to the screen.

As shown in the figure, the tabbed substrate (1) has a film layer (60) via a bonding adhesive layer (3) so that it does not come off from the film layer (60) during a peeling operation. To be joined to. Usually, the bonding adhesive layer has a peel strength greater than the peel strength of the re-peeling adhesive layer in order to effectively prevent peeling from the film layer base material (1). Further, the removable adhesive layer (2) is arranged so as to face the bonding adhesive layer (3) with the base material (1) interposed therebetween. Therefore,
In the example shown, the tabbed substrate (1) is arranged between the film layer and the repeelable adhesive layer. It should be noted that the tabbed substrate is not limited to a location where the tabbed substrate is arranged as much as possible so as not to come off from the film layer during the peeling operation. For example, it may be fixed on the surface of the film layer. In that case, the removable adhesive layer and the tabbed substrate are incorporated into the optical filter as separate components.

As shown, when the tabbed substrate (1) is partially disposed near the outer periphery of the film layer backside (602), the repeelable adhesive layer is attached to the film layer backside (602). It is partially arranged near the outer peripheral edge.
In this case, the optical filter is partially brought into close contact with the display screen, and a gap (G) is formed between the optical filter (6) and the display screen (70). Fixing by such partial contact makes removal of the optical filter particularly easy. In the illustrated example, four tabbed substrates (1) are fixed to four corners of a film layer (60) having a substantially rectangular front surface and a back surface, and the film layer (that is, an optical filter) is displayed at these four corners. It is fixed in close contact with the screen (70).

The removable adhesive layer may be provided on the entire back surface of the film layer as long as the optical filter can be easily removed. In that case, the number of tabs may be less than or more than four. However, from the viewpoint of facilitating the removal of the optical filter, at least two tabs are required so that a peeling operator (user or the like) can peel them with both hands.

For example, as shown in FIG. 6, an optical filter (6) having two tabs (10a, 10b) is fixed to a screen in a frame (71) of a display device (7). The optical filter (6) shown in FIG. 6 is, for example, a surface (1) of a tabbed substrate (1) as shown in FIG.
The film layer (60) can be formed by joining the film layer (60) through a bonding adhesive layer (not shown) other than the portions corresponding to the tabs (10a, 10b) in 1). The tabbed substrate as shown is
For example, a polymer film may be cut into a shape as shown in the figure (tabs projecting from two locations on the outer periphery), or a polymer film having the same shape and dimensions as the film layer may be prepared. It can also be formed by joining a piece of polymer film to be a tab to the film.

In the optical filter of the present invention, the size and shape of the tab make it easy to peel off the optical filter, and
It should be decided so that the tab will not be damaged during the peeling operation. For example, the thickness of the tab is usually 50 to 300 μm. The length of the tab in the extending direction (the length protruding from the edge of the film layer) is usually 3 to 30 mm, preferably 5 to 20 m.
m. The length of the tab in the direction orthogonal to the extending direction is substantially equal to or less than the outer peripheral edge of the film layer to which the tab is bonded, and is usually 3 mm or more, preferably 5 mm or more. It is particularly preferably 10 mm or more. As the shape of the tab, various shapes may be adopted, as in the above-described illustrated example. For example, triangle, square, circle, sector,
Geometric shapes such as ellipses and elliptical fans, and shapes that imitate objects (flower shapes, star shapes, hand shapes, foot shapes, etc.) give the observer an appearance with enhanced design. preferable. The number of tabs is preferably 4 or less in order not to impair the appearance around the display screen when the optical filter is fixed.

In the liquid crystal display device (7) shown in FIGS. 1, 2 and 6, the display screen (70) is surrounded by a frame (71). A step is formed between the outer peripheral portion of the display screen and the frame, and the screen (70) is arranged in a recessed portion surrounded by the inner peripheral surface (710) of the frame so that an observer can observe it. As shown,
Total thickness of optical filter (6) (double-sided tape with tab 1
The thickness including 00) is less than or equal to the height of such a step. The optical filter (6) is attached to the screen (7
0) is fixed so as to cover almost the entire surface, and the tab (10) passes through the gap formed between the inner peripheral surface (710) of the frame and the optical filter (6), and the outer periphery of the film layer (60). To the outside, the extended end of the tab (10) extends to the frame (see FIG. 2). Therefore, when removing the optical filter, it is not necessary to insert a fingernail or a sharp-edged tool between the inner peripheral surface of the frame and the optical filter. This is because the optical filter (60) can be easily removed by lifting the tab (10) with a finger and pinching the tab to apply a peeling force.

In the display device (7) used in the illustrated example, the frame (71) has an inner peripheral surface (71).
0) and the upper surface (711) are connected with a slope (712). The tab (10) has an inner peripheral surface (710) of the frame.
Through the gap between the optical filter (6) and the optical filter (6), and is almost in close contact with the sloped surface (712) of the frame, but the upper surface (711).
Is not in contact with. The tab (10) is arranged above the upper surface (711) by a predetermined height, and the tab (10) is in a state of floating from the frame. When the thickness of the tab is relatively large or when the waist of the tab is relatively strong, the floating height of the tab from the frame surface tends to increase. If the floating height of the tab is too large, the appearance around the display screen when the optical filter is fixed may be impaired. Therefore, it is preferable to make the floating height of the tab as small as possible.

If it is desired to reduce the floating height of the tab, several improved configurations are adopted as follows. For example, the tab (10) is scored so that it fits closely to the frame surface along the shape of the frame. A removable adhesive layer is also arranged on the back surface of the tab (10) so that the removable tab (1
0) may be adhered to the frame upper surface (711). Also, using an adhesive piece consisting of a removable single-sided adhesive tape,
The tab (10) may be removably adhered to the frame (71).

Further, as shown in FIG. 8, tabs (10a, 10a,
10b) can be positioned so that the floating height of the tab can be made as small as possible. In the illustrated example, two corners (near the apex) of the film layer (60) having a triangular shape with a predetermined area are cut out, and tabs are formed outward from the outer peripheral part of the corners left after the notch. (10a, 10
A tabbed substrate is arranged on the back side of the film layer (60) so that b) extends. Also, in this case, tab (1
The extension length of 0) into the frame may be made as small as possible so as to contact the frame slope (712) but not to the top surface (711).

On the other hand, the optical filter of the present invention can be effectively used for a display device having no frame step. For example, FIG. 9 shows an example in which an optical filter (6) is fixed to a display device (7) having no frame step around the display screen. As a display device having such a configuration, there are a mobile phone, a flat-screen liquid crystal monitor (the display screen and the frame surface are arranged on the same plane), and the like.

The optical filter (6) shown in FIG. 9 has a film layer (60) having the same shape (substantially rectangular) and the same size as an observable display screen, and a film layer (60) extending outward from the outer periphery thereof. It comprises two tabs (10a, 10b).
These tabs (10a, 10b) are attached to the film layer (6
0) are continuously arranged along the two opposite sides. That is, the overall shape of the optical filter (6) is substantially rectangular. This is advantageous for improving the design of the display screen without impairing the appearance of the display screen when the optical filter is fixed.
The film layer (60) is, for example, an antireflection film,
An optical film such as a louver film is cut and formed to have a predetermined shape and size.

As shown in FIG. 9, the tab portion can be colored in a desired color, and visual information such as a design, a symbol and a character can be arranged. It should be noted that such visual information may include, for example, a product name or a trademark of the display device, a user's name or initials, a advertising phrase not directly related to the display device, and other messages.

The optical filter (6) as shown has, for example, a flexible substrate having a joint portion having the same shape and size as the film layer (60) and a tab portion connected to the joint portion. Can be prepared, and the film layer (60) can be adhered only to the bonded portion of the base material. Alternatively, a double-sided tape with tabs each having two tabs (10a, 10b) may be used.

(Double-sided Tape with Tab) The double-sided tape with tab of the present invention is used by incorporating it into an optical filter as described above, and is suitable for constituting the optical filter of the present invention. The double-sided tape with tabs is shown in FIG.
As shown in FIG. 1, a flexible tabbed substrate (1)
And an adhesive layer (3) for bonding, which adheres to the surface of the base material (1) and bonds the base material to the back surface of the film layer, and an adhesive layer (3) which adheres to the back surface of the base material (1) and adheres to a surface (display screen, etc. ) Is removably adhered to the substrate, and the substrate (1) and the re-peeling adhesive layer (2) for fixing the film layer bonded to the substrate (1) to the adherend surface. The double-sided tape with tab (100)
As described above (see FIGS. 1 and 2), the tabs (10) extend outwardly from the outer perimeter of the film layer when joined to the film layer. Adhesive (or fixed) to both the film layer and the display screen as shown in FIG.
The part that is not covered is the tab (10). That is, in a part of the entire base material (1), the bonding adhesive layer (3) and the re-peelable adhesive layer (2) are fixed to the base material so that the front and back surfaces of the part face each other. Is located in. The adhesive surface of the bonding adhesive layer (3) and the removable adhesive layer (2)
The adhesive surface has a substantially same area.

The tabbed double-sided tape may have a structure as shown in FIG. In the illustrated example, the bonding adhesive layer (3) is arranged only on a part of the surface of the base material (1), that is, a part bonded to the film layer, and the bonding adhesive layer (3) is arranged on the tab (10) part. 3) is not placed. on the other hand,
The repeelable adhesive layer (2) is disposed on almost the entire back surface of the base material (1), but the adhesive surface of the repeelable adhesive layer (2) disposed on the tab (10) is covered with the coating film (4). ) Is covered. In the illustrated example, the surface side of the tab (10) on which the adhesive layer is not arranged is non-adhesive, but the tab (10)
The rear surface side on which the removable adhesive layer is arranged is adhesive as it is. The covering film (4) is arranged in the tab (10).
The back side of can also be non-adhesive.

The covering film (4) is made of a material and thickness that does not impair the flexibility of the entire tab. For example, the covering film (4) can be formed from a polymer film, paper, metal foil or the like which is not tacky at room temperature (about 25 ° C.).
As the polymer of the polymer film, for example, polyester, acrylic polymer, polyvinylidene fluoride, polyurethane, epoxy resin, polyvinyl chloride or the like can be used. The thickness of the coating film (4) depends on the thickness of the substrate, but is usually 1 to 200 μm, preferably 2 to 100 μm.
m.

The covering film (4) may be used without peeling from the re-peeling adhesive layer when the double-sided tape with tabs is used, or may be peelable. For example, as described above, when the optical filter is fixed to the display device, the tab (10) is removably adhered to the surface of a component (frame, etc.) around the display screen via the re-peelable adhesive layer (2). May be. When peeling the film layer from the adhered surface, the tab can be easily peeled from the surface of the component. When the double-sided tape with a tab is used without peeling off the covering film (4), the peeling adhesive layer (of the covering film (4) ( It is preferable that the surface to be adhered to 2) is subjected to easy adhesion treatment. The easy adhesion treatment is, for example, corona treatment, primer treatment or the like.

As mentioned above, the tab (10) can also be colored. In this case, in the example shown in FIG. 4, the covering film (4) may be formed of a colored film. The color and appearance on the surface side of the colored film visually recognized through the base material (1) and the removable adhesive layer (2) are preferably the same as those of the parts around the display screen. Further, it is preferable that the color and appearance of the back side of the colored film be different from those on the front side. Thereby, when the double-sided tape with tabs is adhered to the film layer, the operator distinguishes the surface on which the repeelable adhesive layer is arranged from the surface on which the bonding adhesive layer is arranged from the color and appearance of the covering film. This is because it is easy to do.

The double-sided tape with tab may have a structure as shown in FIG. In the illustrated example, the removable adhesive layer (2) is arranged on almost the entire back surface of the base material (1), and the bonding adhesive layer (3) is arranged on almost the entire front surface of the base material (1). The bonding surface of the bonding adhesive layer (3) corresponding to the tab (10) is covered with the coating film (4), and the remaining bonding surface forms the bonding portion (30). The covering film (4) may be the same as that shown in FIG. 4, and it is preferable to use a material and a thickness that do not impair the flexibility of the entire tab. Further, similarly to the above, it is preferable to form the covering film (4) from a colored film from the viewpoint of the convenience of the bonding work.

In the example shown in FIG. 5, when the optical filter is fixed to the display device, the tab (10) is removably adhered to the surface of the component around the display screen through the removable adhesive layer (2). it can. Further, the second covering film may be arranged on the portion corresponding to the tab of the removable adhesive layer (2) so that both the front and back surfaces of the tab (10) are non-adhesive.

The tabbed double-sided tape of the present invention can be manufactured by applying a method for manufacturing a normal double-sided tape. For example, a double-sided tape with a tab (10
0) can be manufactured as follows. First, a raw tape (109) as shown in FIG. 10 is prepared. Original (10
In 9), first, a first adhesive layer serving as an adhesive layer for bonding is fixedly arranged on the surface of a transparent original fabric substrate (not shown) having a length direction, and a re-peelable adhesive layer is provided on the back surface. It can be obtained by arranging the second adhesive layer to be fixed to prepare a precursor of the tape original fabric (109) and arranging the original fabric covering film (49) on the surface of the first adhesive layer. In the illustrated example, the remaining adhesive surface of the first adhesive layer, which is not covered with the original fabric covering film (49), is covered with the first original fabric liner (59). The adhesive surface of the second adhesive layer on the back surface side of the base material is preferably covered with the second original fabric liner.

Raw tape (109) obtained as described above
From the above, the tabbed double-sided tape (100) of the present invention can be obtained by cutting so as to have a predetermined size and shape. However, at the time of cutting processing, the original fabric coating film (4
The cutting position, size and shape are determined so as to include both the portion coated with 9) and the portion coated with the first raw liner (59). In the illustrated example, the tape raw fabric (109) is cut along the cutting line (8) in a direction orthogonal to the length direction of the tape raw fabric (109) to manufacture a double-sided tape with a tab (100). To do.

After manufacturing the double-sided tape with a tab (100) as shown in FIG. 10, the tab portion is cut as shown in FIG. 11 to obtain a tab (10) having a predetermined processing shape.
It is also possible to obtain a tabbed double-sided tape (100) having The shape of the tab may be a semi-circular shape as shown in the figure, or may be various geometrical figures or figures imitating objects as described above.

The adhesive layer (bonding adhesive layer or re-peelable adhesive layer) can be usually formed from a coating film of a paint containing an adhesive component. Such a coating film may be formed by directly coating on the substrate, or a coating film once formed on the process substrate,
It can also be formed by transferring onto a substrate. As shown in FIGS. 3 and 4, a masking tape can be used when the coating material is directly applied onto the substrate and the adhesive layer is partially formed on one or both surfaces of the substrate. That is, after a masking tape is attached to a part of the base material to form a coating film, the masking tape is removed to form a part without a coating film.

The base material is transparent at least at the portion where it is in close contact with the film layer. The transparency of the base material is usually 80% or more, preferably 85%, if it is defined by the light transmittance.
As described above, 90% or more is particularly preferable. Also, the base material is
It is usually formed from a polymer sheet. As the polymer, for example, polyester (PET, PEN, etc.), acrylic polymer, vinyl chloride polymer, polyurethane or the like can be used.

As for the size and shape of the base material, the peeling work is easy,
Moreover, it is preferable that the tape is not damaged during the peeling work. For example, the thickness of the base material is usually 20 to 30.
It is 0 μm, preferably 30 to 200 μm. When another layer such as a coating film is fixed on the front surface and / or the back surface of the tab, the thickness of the entire tab is usually 50 to 300 μm.
m. The extension length of the tab is usually 5 to 30 mm,
It is preferably 10 to 20 mm. The length of the tab in the direction orthogonal to the extending direction is substantially equal to or less than the outer peripheral edge of the film layer to which the double-faced tape with tab is bonded, and is usually 5 mm or more, preferably Is 10 mm or more. Further, the shape of the tab is preferably the above-mentioned geometrical figure or a figure imitating an object.

(Adhesive Layer for Bonding) The adhesive layer for bonding preferably has a transparency as high as possible. The light transmittance is usually 80% or more, preferably 85% or more, and particularly preferably 90%.
That is all. The bonding adhesive layer can be formed from a normal adhesive such as a pressure-sensitive adhesive, a heat-sensitive adhesive, and a curable adhesive.
It usually contains a tacky polymer, which is preferably crosslinked. Adhesive polymer (self-a
The dherent polymer) is a polymer that exhibits adhesiveness at room temperature (about 25 ° C.). The adhesive polymer of the adhesive layer for joining is
For example, acrylic polymers, nitrile-butadiene copolymers (NBR, etc.), styrene-butadiene copolymers (SBR, etc.), non-crystalline polyurethane, silicone polymers and the like. The adhesive polymer is composed of one of these polymers alone or a mixture of two or more thereof. The tacky polymer can be obtained by polymerization using a mixed monomer containing a predetermined starting monomer. The polymerization method is a usual method, for example, solution polymerization, bulk polymerization, emulsion polymerization and the like. The thickness of the adhesive layer for bonding is usually 5 to 50 μm.
m.

The peel strength (F) of the bonding adhesive layer and the peel strength (R) of the re-peeling adhesive layer (F-R) were 90 inches / min peeling speed with respect to the PET surface, respectively. 90
In the comparison between the values measured at the peel angle of 3 degrees
N / 25 mm or more is preferable and 5 N / 25 mm
The above is particularly preferable. If the peel strength difference F-R is too small, when the optical filter is repeatedly removed,
Peeling may occur between the substrate and the film layer.
The peel strength (F) of the bonding adhesive layer is not particularly limited, but is usually 4 to 50 N / 25 mm. The thickness of the bonding adhesive layer is usually 10 to 200 μm, preferably 20 to 100 μm.

(Re-peelable Adhesive Layer) The re-peelable adhesive layer has an adhesive force (peel strength) in a predetermined range so that the optical filter can be peeled off without damaging the adherend surface. Suitably, as described above, a peeling speed of 90 inches (about 229 cm / min) and a peeling angle of 90 degrees with respect to a surface of polyethylene terephthalate (PET), measured at a peeling angle of 90 degrees are 0.1 to 4.5.
It has a peel strength in the range of N / 25 mm. If this peel strength (sometimes referred to as “to PET peel strength”) is too small, the optical filter may fall off from the adhered surface during use, and if it is too large, the film layer may not adhere to the louver film. Even when such an optical film having relatively low flexibility is included, the optical filter can be easily removed. Therefore, from these viewpoints, the peel strength of the adhesive layer from PET is preferably in the range of 0.5 to 4.0 N / 25 mm,
The range of 1 to 3.6 N / 25 mm is particularly preferable.

The removable adhesive layer preferably contains a tacky polymer and a removable component. This makes it easy to control the peel strength of the removable adhesive layer within the above range. For example, it is preferable to use a relatively large amount of a crosslinking agent as a component for imparting removability to crosslink the tacky polymer to increase the cohesive force of the repeeling adhesive layer. In addition, it is preferable to use a crystalline polymer as a component for imparting removability, to control tack of the adhesive surface of the reattachment adhesive layer to be low, and to impart heat releasability to the reattachment adhesive layer. The type and content of these releasability imparting components are appropriately determined so as to exert a predetermined effect and not impair the transparency of the repeeling adhesive layer.

In the present invention, the tacky polymer used in the removable adhesive layer is also a polymer that exhibits tackiness at room temperature (about 25 ° C.). Examples of the adhesive polymer include acrylic polymers and nitrile-butadiene copolymers (NBR).
Etc.), styrene-butadiene-based copolymer (SBR, etc.),
Examples include non-crystalline polyurethane and silicone polymers. The adhesive polymer is composed of one of these polymers alone or a mixture of two or more thereof. The tacky polymer can be obtained by polymerization using a mixed monomer containing a predetermined starting monomer. The polymerization method is a usual method, for example, solution polymerization, bulk polymerization, emulsion polymerization and the like.

When the tacky polymer is crosslinked, it is easy to control the peel strength of the removable adhesive layer to a desired range. In that case, a crosslinking agent is usually used for crosslinking. As the cross-linking agent, a polyfunctional isocyanate compound, an epoxy resin, a bisamide-based cross-linking agent or the like can be used. These react with a carboxyl group of the adhesive polymer or a crosslinkable functional group such as a hydroxyl group optionally contained to crosslink the adhesive polymer and act to enhance removability. When imparting removability to the re-adhesive adhesive layer using a cross-linking agent and other re-peeling property imparting component (such as a crystalline polymer), the content of the cross-linking agent is 100 parts by mass of the adhesive polymer. On the other hand, it is preferably 1 to 5 parts by mass, and particularly preferably 1.
It is in the range of 5 to 4 parts by mass.

The removable adhesive layer may contain a rubber polymer. As the rubber-based polymer, for example, any one kind or a mixture of two or more kinds selected from the group consisting of silicone rubber, fluororubber, acrylic rubber, ethylene propylene rubber, and acrylonitrile butadiene rubber can be used. It is preferable that the rubber-based polymer is also cross-linked, which makes it easy to control the peel strength within the above range.

The elastic modulus of the adhesive layer containing the rubber-based polymer is preferably determined so that the peel strength falls within the above range. For example, the elastic modulus G (storage elastic modulus) measured in a shear mode at a frequency of 1 rad / sec at 25 ° C. by a dynamic viscoelasticity measuring method is usually 20 to 300 kP.
a, preferably 30 to 200 kPa, particularly preferably 50 to
It is 100 kPa. If the elastic modulus G is too small, the removability may be deteriorated. On the contrary, if the elastic modulus G is too large, the adhesion to the adherend surface of the optical film may be deteriorated.

The removable adhesive layer also preferably has a transparency as high as possible. The light transmittance is usually 80% or more, preferably 85% or more, and particularly preferably 90% or more. The thickness of the removable adhesive layer is usually 10 to 200 μm, and preferably 20 to 100 μm.

(Film Layer) The film layer included in the optical filter of the present invention contains an optical film. The optical film is a film capable of imparting an optical function to the adherend surface. The "optical function" here is a function of controlling one or more characteristics selected from the group consisting of light transmittance, reflectance, refractive index, and transmission direction. The optical film is, for example, a louver layer alone or a louver film including a louver layer. The louver layer is a film in which minute louvers (louver-like elements) are incorporated inside the layer, and the light transmission direction can be controlled. The louver layer usually includes a light transmitting portion and minute louver-like elements that block light.

The light transmitting portion is defined by the width of the louver element (the dimension in the direction parallel to the surface of the louver layer and orthogonal to the length direction of the louver element) so that the light transmittance of the entire optical filter does not decrease. Also preferably has a large width. The width of the light transmitting portion is preferably 50 to
It is 500 μm, particularly preferably 70 to 200 μm. The width of the louver-shaped element is preferably smaller than that of the light transmitting portion so that the light transmittance of the entire optical filter does not decrease. The width of the louvered element is 1-100
μm, more preferably 10 to 50 μm. The angle of the louvered element is usually in the range of 45 to 90 degrees. The angle of the louver-shaped element is an angle with respect to the surface of the louver layer, and 90 ° is set when the louver-shaped element is orthogonal to the surface of the film layer.

The thickness of the louver layer can be appropriately determined according to the purpose of use. However, as the thickness decreases, the effect of controlling the traveling direction of light tends to decrease. Further, if the thickness becomes thick, it becomes difficult to reduce the thickness of the entire optical filter. Therefore, its thickness is preferably 10-
The thickness is 1,000 μm, particularly preferably 40 to 500 μm.

The light transmitting portion of the louver layer is preferably formed of a highly transparent polymer. As the polymer, a thermoplastic resin, a thermosetting resin, an energy ray curable resin such as ultraviolet ray can be used, for example, cellulose acetate butyrate, a cellulosic resin such as triacetyl cellulose, polyethylene, a polyolefin resin such as polypropylene, Examples thereof include polyester resins such as polyethylene terephthalate, polystyrene, polyurethane, vinyl chloride, acrylic resin, and polycarbonate resin.

On the other hand, the louver element absorbs light,
Alternatively, it is formed of a light-shielding material that can reflect light. Examples of such a substance include (1) dark pigments or dark dyes such as black and gray, (2) metals such as aluminum and silver, (3)
Examples include dark-colored metal oxides, (3) the above polymers containing a dark-colored pigment or a dark-colored dye, and the like.

The louver layer as described above can be manufactured in the following manner, for example, as disclosed in the patent introduced in the above-mentioned prior art. First, a louver-like element is formed by fixing a layer containing a light-shielding substance on one main surface of a polymer film used as a light-transmitting portion, and a set of a laminated film composed of a polymer film / light-shielding substance layer is prepared. A plurality of such sets are prepared, and the plurality of sets are laminated to form a louver film precursor in which polymer films / light-shielding substance layers are alternately arranged and fixed to each other. Using such a precursor, the louver layer can be obtained by slicing so as to have a predetermined thickness along the direction (stacking direction) orthogonal to the main surface (stacking surface) of the precursor.

As the louver film containing the louver layer, a commercially available louver film can be used. Further, a commercially available louver layer for a louver film can be used as a louver layer used as a constituent member of the optical filter of the present invention. As a specific example of such a commercially available louver film, the above-mentioned "Light Control Film (trademark)" manufactured by 3M can be mentioned.

As the optical film other than the louver film, an antireflection film, a Fresnel lens film, an electromagnetic shield film or the like can be used. The film layer may include two or more types of optical films,
A light transmissive film other than the optical film may be included. The total thickness of the film layer is usually 20 to 100
It is 0 μm.

[0072]

EXAMPLE 1 In this example, a double-sided tape with a tab having a cross-sectional shape shown in FIG. 4 and a tab having a substantially semicircular shape as shown in FIG. 11 and an optical film were used in combination. An optical filter was produced. Two double-sided tapes with tabs having the same shape and size were used.

The optical film is a louver film having a thickness of about 260 μm and a viewing angle of 90 degrees (manufactured by 3M, product number: O).
AG90). In this louver film, the width of the light transmitting portion is 100 μm and the width of the louver element is 1
It was 0 μm. Further, the optical film used has a rectangular front surface and a back surface, and the plane dimension thereof is 245 mm × 1.
It was 85 mm.

The double-sided tape with tabs was manufactured as follows. As a transparent substrate, the length (dimension along the extending direction of the tab) is about 2 cm, the width is about 1.5 cm, and the thickness is 100 μ.
m PET film was used. Light transmittance of base material is 90%
Met. 1 cm as an adhesive layer for bonding on the surface of the base material
The first adhesive film, which was cut into a rectangle of 1.5 cm, was attached. The first adhesive film has a length of 1.5
The side of cm and the edge (side) at one end in the length direction of the base material were aligned with each other, and were brought into close contact with the base material. As a result, between the other end of the base material and the central portion in the length direction, a portion serving as a tab in which the bonding adhesive layer was not arranged was formed. The first adhesive film was formed from a transparent adhesive tape manufactured by 3M (product number # 9483).
The light transmittance of this adhesive tape was 93%. The adhesive surface of the first adhesive film that was not in close contact with the base material was protected by a liner.

On the other hand, on the back surface of the base material, a second peeling adhesive layer was cut into a rectangle of 2 cm × 1.5 cm.
An adhesive film was attached. The second adhesive film is PA
It was formed from a transparent adhesive tape (product number: SBHF50) manufactured by NAC. The light transmittance of this adhesive tape was 93%. The adhesive surface of the second adhesive film that was not in close contact with the base material was protected by a liner.

Finally, the liner of the re-peelable adhesive layer (second adhesive film) is kiss-cut, and the liner is peeled off so that only the adhesive surface corresponding to the tab portion where the adhesive layer for bonding is not exposed is exposed. A coating film was attached to the exposed adhesive surface to complete the tabbed double-sided tape of this example. The coating film was an opaque film having a white coating film on one surface of the PET film and a black coating film on the other surface, and the total thickness was about 50 μm. The coating film was adhered with the white side facing the removable adhesive layer.

The peel strength of the above two adhesive films from PET was measured as follows. The adhesive film is a PET film (thickness 100 μm, manufactured by Unitika Ltd., product number:
BUM-100) was prepared by adhering to a test piece,
The peel strength was measured under predetermined conditions. Peel strength tester (manufactured by Imass (USA), trade name: I-mass)
Tester, MODEL SP-102C), peeling angle 90 degrees, peeling speed 90 inches / minute (about 22)
(9 cm / min).

The test piece for peel strength measurement was prepared as follows. First, the adhesive film was cut into 15 cm × 25 mm to prepare a sample. This sample was placed on a surface of a PET film that had been washed with isopropyl alcohol under the conditions of 20 ° C. and 65% RH, according to JIS Z023.
It was pressure-bonded with a roller (mass 2 kg) specified in No. 7, and left for 3 hours under the same conditions. After standing, the peel strength was measured under the above conditions. The peel strength of the first adhesive film to PET measured in this manner was 20 N / 25 mm, and the peel strength of the second adhesive film to PET was 2 N / 25 mm.

The optical filter of this example was fixed to the liquid crystal display screen of the notebook PC via the removable adhesive layer of the double-faced tape with tab as shown in FIG. Thereby, a display with an optical filter according to the present invention was produced. In the filter-equipped display produced in this example, the tabbed double-sided tape is bonded to the two corners of the optical filter so that one tabbed double-sided tape is arranged at each of the two corners on the upper side of the display screen. It fixed through the adhesive layer. In the example shown in FIG. 1, the double-sided tape with two tabs on the lower side of the display screen was omitted.

A practical test was conducted using the display with a filter manufactured in this way. First, it is easy to fix the optical filter to the display screen, and it is possible to obtain a sufficient look-around prevention effect. Read the screen from the angle direction (about 45 degrees) away from the front direction and read the screen display. I couldn't. On the other hand, it was easy to remove the fixed optical filter and fix it again. In the optical filter of this example, the two tabs are, as shown in FIG.
The extended end of the tab extends to the frame surface, passing through the gap formed between the inner peripheral surface of the frame and the optical filter, beyond the frame slope. Although the tab was in contact with the frame slope, it did not contact the frame surface, and the tab floated above the surface. Therefore, when removing the optical filter, you can easily pinch the two tabs,
The optical filter could be easily removed by pulling the pinched tab and applying force.

[Brief description of drawings]

FIG. 1 is a diagram showing a method for manufacturing an optical filter of the present invention and a procedure for fixing the optical filter to a display device.

FIG. 2 is a partial cross-sectional view of a display device having the optical filter of the present invention fixed thereto.

FIG. 3 is a cross-sectional view of an example of the double-faced tape with a tab of the present invention.

FIG. 4 is a cross-sectional view of another example of the double-faced tape with a tab of the present invention.

FIG. 5 is a cross-sectional view of another example of the double-faced tape with a tab of the present invention.

FIG. 6 is a plan view of a display screen having an optical filter fixed according to an aspect of the present invention.

FIG. 7 is a plan view of a substrate with tabs of the optical filter of the present invention.

FIG. 8 is a plan view of a display screen with an optical filter fixed according to another aspect of the present invention.

FIG. 9 is a plan view of a display screen on which an optical filter is fixed according to another aspect of the present invention.

FIG. 10 is a diagram showing an example of a method for manufacturing a double-sided tape with a tab according to the present invention.

FIG. 11 is a plan view of a preferred example of the tabbed double-sided tape of the present invention.

[Explanation of symbols]

6: Optical filter, 60: Film layer, 100: Double-sided tape with tab, 10, 10a, 10b: Tab; 7: Display device, 70: Display screen, 71: Frame; 1: Substrate with tab, 2: Removable Adhesive layer 3: Adhesive layer for joining

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H091 FA37X FA50X FD06 FD16                       LA09                 2K009 AA02 BB28 CC24 CC34 DD01                 4J004 AA05 AA06 AA07 AA10 AA11                       AA14 AB01 AB03 AB04 CA02                       CA03 CA04 CA05 CA06 CA08                       CB02 CC03 CD02 CD08 CE03                       EA06 FA04                 5G435 AA00 AA01 AA09 BB12 GG11                       HH03

Claims (7)

[Claims] 1. A film layer comprising: (a) an optical film, the film layer having a front surface observed by an observer and a back surface facing the front surface; and (b) fixedly on the back surface side of the film layer. An optical filter that is arranged and has a removable adhesive layer that can be removably adhered to the adherend, and is fixed to the adhered surface via the removable adhesive layer. An optical filter, further comprising a flexible tab disposed on the. 2. The optical filter of claim 1, wherein the tab extends outward from the outer periphery of the film layer. 3. The tab of claim 1, wherein the tab extends outwardly from a covered region of the adhered surface covered by the film layer when the optical filter is secured to the adhered surface. Optical filter. 4. The optical filter according to claim 1, wherein the tab is a substrate integrally bonded, and further comprising a tabbed substrate fixedly arranged with respect to the film layer. . 5. The optical filter according to claim 4, wherein the tabbed substrate is disposed between the film layer and the removable adhesive layer. 6. The optical filter according to claim 1, wherein the removable adhesive layer is partially disposed in the vicinity of the outer peripheral edge of the back surface of the film layer. 7. (i) a flexible tabbed substrate, and (ii) the substrate is adhered to the front surface of the substrate, and the substrate is bonded to the back surface of a film layer containing an optical film. The bonding adhesive layer and (iii) the back surface of the base material and the releasable close contact with the adherend surface, and the base material and the film layer bonded to the base material A double-sided adhesive tape with a tab, wherein the tab extends outward from the outer circumference of the film layer when bonded to the film layer.