JP2013218118A - Both-sided pressure-sensitive adhesive sheet for information display surface, protective sheet for information display surface, and methods of manufacturing both-sided pressure-sensitive adhesive sheet and protective sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a pressure-sensitive adhesive free of strain on a both-sided pressure-sensitive adhesive sheet which is for sticking a protective cover 10 on a display surface of a liquid crystal display, etc., and imparts a window frame for decoration to a peripheral edge of a display region on the information display surface.SOLUTION: A both-sided pressure-sensitive adhesive sheet 20' has a structure such that a window frame 30 formed of a colored layer is embedded at a position of one of the top surface, the reverse surface, and a thickness-directional intermediate part. The both-sided pressure-sensitive adhesive sheet 20' which has a strain-free pressure-sensitive adhesive 21 while having a shape corresponding to a step shape formed between the window frame 30 and a peel film 40 by applying and then curing an uncured pressure-sensitive adhesive composition 21' onto the window frame 30 and into the window frame 30 from one surface or both surfaces of the window frame 30 formed on the peel film 40. The both-sided pressure-sensitive adhesive sheet 20' which is thus obtained is stacked on a protective cover body 10', and cut at need, and the protective sheet 1 having a pressure-sensitive adhesive layer 20 formed on one surface of the protective cover 10 is stuck on an information display surface.

Description

  The present invention relates to a double-sided pressure-sensitive adhesive sheet for information display surface, a protective sheet for information display surface, and a method for producing the double-sided pressure-sensitive adhesive sheet and protective sheet, and more specifically, information display devices such as liquid crystal display, plasma display, and organic EL. For the purpose of protecting the display surface, a double-sided pressure-sensitive adhesive sheet for adhering a protective cover to the display surface, and a protective sheet comprising a laminate of the protective cover and an adhesive layer, the information display device being adhered The present invention relates to the double-sided pressure-sensitive adhesive sheet, the protective sheet, and a method for producing the same, which can form a desired decorative window frame on the display surface peripheral edge.

  In this specification, “sheet” includes “film”.

  In display panels such as liquid crystal displays, plasma displays, and organic EL, antireflection treatments are applied to the substrate on the display surface side of the display body and the surface of the polarizing filter for the purpose of improving impact resistance and improving visibility. A protective cover such as a glass plate or an acrylic plate is affixed. In addition, in the case of a touch panel type display panel, an input as a touch panel can be made between the aforementioned substrate and the protective cover. A functional member is disposed.

  As an example, a liquid crystal display will be described as an example of a display panel. In the liquid crystal display, a liquid crystal 153 is enclosed between two glass substrates 151 and 151 on which a transparent electrode 152 is formed as shown in FIG. So that the glass substrate 151 on the information display surface side (the side opposite to the backlight 154) can be suitably protected when an external impact or the like is applied. The protective cover 110 is attached to the surface of the polarizing filter (not shown) attached to 151 via the spacer 120 with an appropriate gap G, and even when an impact is applied to the protective cover 110. This shock is buffered by the gap G so that it is not directly applied to the glass substrate 151 of the display main body 150. Yes.

  Note that a display panel, particularly a display panel provided in a mobile phone, a smartphone, a tablet PC, or a portable game machine, protects the outer peripheral portion of the display area of the display surface (the portion indicated by hatching in FIG. 7A). The cover 110 is colored with black, white, or other colors to form a decorative window frame 130. Such a window frame 130 is made of glass as shown in FIG. It is formed by printing on the back surface of the protective cover 110 formed of a plate or the like, and an adhesive tape 121 is attached to the position where the window frame 130 is formed to protect it on the glass substrate 151 of the liquid crystal display via a gap G. A cover 110 is attached.

  As described above, affixing the protective cover 110 to the glass substrate 151 via the gap G is effective in protecting the glass substrate 151, but the glass substrate is surrounded by the air enclosed in the gap G. Since the air layer is formed between the protective cover 110 and the protective cover 110, each interface is caused by the difference in the refractive index between the protective cover 110 and the refractive index of the air layer and the refractive index between the air layer and the glass substrate 151. Since the reflectivity increases by 2 to 3% every time, a total increase in reflectivity of 4 to 6% occurs at the two interfaces.

  Such an increase in reflectance, for example, causes a decrease in backlight transmittance in a liquid crystal display, making it difficult to see information. In addition, when a display panel is used outdoors, sunlight is reflected. This makes the displayed information difficult to see because it is in the viewer's field of view.

  In order to deal with such problems, it is conceivable to increase the brightness of the backlight to ensure visibility. However, mobile phones such as mobile phones, smartphones, tablet PCs, digital cameras, electronic notebooks that use batteries as power sources, etc. For devices of the type, increasing the brightness of the backlight leads to an increase in power consumption. Therefore, it is necessary to select whether to increase the size of the battery to cope with this, or to accept that the usable time is shortened. Therefore, in the above products that are required to be thinner and lighter and have a longer continuous use time, such a response causes a loss of competitiveness in the market.

  Therefore, there is a demand for a structure that can improve the visibility in the outdoors while allowing the above-described shock absorption.

  As a configuration for improving the visibility, the gap G between the protective cover 110 and the glass substrate 151 of the display panel is transparent, and the refractive index is close to that of the protective cover 110 and the glass substrate 151. Filling with a resin has also been proposed, and as a method of filling the gap G, a space G formed between the glass substrate and the protective cover is filled with a gel of a curable resin having the above properties and cured. In addition, a method for adhering a protective plate and a substrate by interposing an adhesive sheet prepared in advance has been proposed (see the prior art column of Patent Document 1).

  In addition, when filling the space G by any of the above methods, in view of the problem of generation of bubbles and air entrainment, a transparent material made of a polymer containing a plasticizer as a buffer layer is formed between the display panel and the protective cover. When a resin sheet (weakly adhesive transparent resin sheet) is attached, water, particularly distilled water or ion exchange water, is applied between the transparent resin sheet and the display panel, between the transparent resin sheet and the transparent protective cover, or both. It has also been proposed that the viewing side of the liquid crystal panel and the transparent protective cover are in close contact with a volatile liquid such as ultrapure water or water / alcohol mixture (see Patent Document 1). There are some which form a hydrophilic liquid layer of acrylic acid, fatty acid, expensive alcohol, carboxylic acid ester and the like (Patent Document 2).

  Furthermore, when laminating with such an adhesive sheet, unevenness is formed on the surface of the adhesive sheet, the panel to be laminated and the convex part of the adhesive sheet are brought into contact with each other, and a part of the peripheral part of the laminate is left. It has also been proposed to remove the air in the recesses by sucking the air in the recesses of the pressure-sensitive adhesive sheet from the remaining part in a sealed state (see Patent Document 3).

  In addition, the applicant applies a protective sheet having a laminated structure of an adhesive elastic body composition obtained by crosslinking an ultraviolet-crosslinking acrylic resin material by ultraviolet irradiation and a cover film (protective cover) made of a polyester resin film. We have already filed an application (Patent Document 4), and in the protective sheet of this structure, instead of a hard protective cover such as a glass plate or an acrylic plate, a flexible cover film is used, so that the cover film is wound into a roll. This makes it possible to improve productivity.

JP-A-9-197387 JP 2011-167862 A JP 2005-319752 A JP 2007-238754 A

  When the conventional technology described above is applied to the protective cover having the window frame described above, the following problems occur.

(1) Problems when filling and curing curable resin in the space When adopting a configuration in which a curable resin is filled between the glass substrate and the protective cover and cured, an ultraviolet curable resin is used as this curable resin If it is adopted, the irradiated ultraviolet rays are blocked by the window frame formed on the protective cover, so that the cross-linking becomes uneven and causes dripping due to poor curing.

  For this reason, when trying to provide the window frame described above, a resin of thermal reaction type is used as the resin to be filled. In this case, the usable time is determined from the design of the peroxide as a polymerization initiator. While it is limited to 5 to 120 minutes, when it is formulated so that the pot life is extended to 24 hours, the reaction becomes dull and dripping occurs and the productivity also deteriorates.

  In addition, in the case of using either UV curable resin or thermosetting resin, the curing shrinkage rate reaches 0.5 to 12%. This shrinkage causes distortion in the transparent resin and deforms the protective cover. As a result, optical characteristics are deteriorated.

(2) Problems when bonding the substrate and protective cover with adhesive sheet When the substrate and protective cover are laminated via the pre-manufactured adhesive sheet, the optical performance will not deteriorate. It is necessary to completely remove the air between the layers. However, when bonding the glass substrate of the display panel and a conventional protective cover made of a hard plate such as glass or acrylic, the surfaces are bonded in surface contact [Fig. 8 (A)], not only is it easy to entrain air during bonding, but it is also difficult to escape the entrained air once pasted.

  In particular, in the protective cover (glass) on which the window frame is printed, since the thickness of the paint layer that becomes the window frame is about 15 to 40 μm, the depth inside the part surrounded by the window frame is about 15 to 40 μm. In addition, a large amount of capital investment is required, such as air is easily confined in the recess, and if this is to be removed, the bonding must be performed under vacuum. ， If placed in a vacuum, the display panel may be damaged.

  Moreover, even when pasting in a vacuum, it is difficult to make the surface of the viscoelastic sheet completely follow the surface shape of the protective cover in which a step is generated due to the formation of the window frame. It is difficult to completely prevent the generation of a cavity in the stepped portion generated in the portion.

  Even if the step of the window frame is filled by deformation of the adhesive sheet, the adhesive sheet in this state is distorted due to deformation, so that this distortion causes optical distortion, Due to the release of the stress remaining in the material with the passage of time due to strain, delamination starting from the stepped portion is likely to occur over time.

  Therefore, as a countermeasure for these, even when bonding is performed under vacuum, it is necessary to perform autoclaving (pressurization and heating) after bonding to release the stress and remove strain from the viscoelastic sheet. Occurs.

  This autoclave treatment requires a relatively long time of 2 to 6 hours, and requires a large amount of equipment investment for introduction and safety management such as explosion-proofing. Loss price competitiveness to be passed on to price.

  In addition, when autoclaving is performed, product inspection after processing is required, which not only increases the number of work steps, but the yield after autoclaving is about 60% at the maximum, and defective products are discarded as a whole display panel. As a result, productivity is significantly reduced.

  In addition, as in the invention described in the above-mentioned Patent Document 3, by forming irregularities on the surface of the pressure-sensitive adhesive sheet, suction after bonding the air between the pressure-sensitive adhesive sheet and the substrate and between the pressure-sensitive adhesive sheet and the protective cover is performed. Can be removed relatively easily, and therefore, bonding under vacuum is not necessary. However, since this bonding method requires that a relatively large surface deformation be generated in the adhesive sheet, The strain generated in the molecular orientation due to the deformation is further increased, and the stress remaining in the viscoelastic sheet is also increased.

  For this reason, when bonding by this method, optical distortion becomes larger than when bonding using a general viscoelastic sheet, and cavities and delamination are likely to occur over time. Furthermore, it is not suitable for the application of a protective cover for information display surfaces such as liquid crystal displays.

  In addition, when bonding is performed by this method, when the air in the concave portion of the viscoelastic sheet is sucked, a suction force is exerted on the display panel, which may damage the display panel.

  In addition, since the window frame has been printed and baked on the glass plate in the past, if a void occurs due to a problem with bonding of the LCD and the touch panel with the transparent adhesive or distortion of the printing step, the glass plate is re-used. The window frame printing part is easily damaged by performing a peeling operation, so-called “wire cutting or chemical etching”, and this glass must be discarded.

  It is clear that it will cause great economic loss not only for large liquid crystals.

  Accordingly, the present invention has been made to solve the above-described drawbacks of the prior art, and by sticking to the display surface of the information display device, a window frame can be formed on the display surface and a display panel can be formed. The display surface and the protective cover can be filled with a transparent adhesive. Therefore, it has excellent optical characteristics and is displayed on the information display surface even in sunlight without increasing the brightness of the backlight. While making information easy to see, it does not create a void between the adhesive layer and the protective cover, and it is difficult to cause optical distortion or generation of voids or delamination with time. An object is to provide a worn double-sided pressure-sensitive adhesive sheet and an information display surface protective sheet.

  Hereinafter, means for solving the problem will be described together with reference numerals used in the embodiment for carrying out the invention. This code is used to clarify the correspondence between the description of the scope of claims and the description of the mode for carrying out the invention. Needless to say, it is used in a limited manner for the interpretation of the technical scope of the present invention. It is not a thing.

In order to achieve the above object, the double-sided pressure-sensitive adhesive sheet 20 ′ for an information display surface of the present invention comprises:
A double-sided pressure-sensitive adhesive sheet 20 ′ for attaching the protective cover 10 to the information display surface of the display panel,
A window frame 30 made of a colored layer formed in a frame shape corresponding to a desired peripheral shape of the information display surface of the display panel, and an adhesive 21 provided on and in the window frame 30 The window frame 30 is embedded in any position in the middle of the front surface, the back surface, or the thickness direction, and has a finished adhesive strength of 4 to 30 N / 25 mm width and a thickness of 20 to 1500 μm.
The adhesive 21 is formed by applying an adhesive composition 21 ′ having a viscosity of 500 to 50,000 cps on the window frame 30 and in the window frame 30 from one side or both sides of the window frame 30 and then curing it. It is characterized in that it is an acrylic, urethane, or silicone pressure-sensitive adhesive 21 having an elongation percentage of 100 to 1400% and a light transmittance of 80% or more (claim 1).

The protective sheet 1 for the information display surface of the present invention is
In the protective sheet 1 that includes a protective cover 10 and an adhesive layer 20 that covers one side of the protective cover 10, and is attached to the information display surface of the display panel via the adhesive layer 20.
The protective cover 10 is a polyester resin film or glass having a thickness of 10 to 300 μm, a light transmittance of 90% or more, and stretched 2 to 10 times in the vertical and horizontal directions,
The adhesive layer 20 has a window frame 30 formed of a colored layer formed in a frame shape corresponding to a desired peripheral shape of the information display surface of the display panel, and on the window frame 30 and in the window frame 30. The window frame 30 is embedded at any position in the middle of the front surface, the back surface, or the thickness direction, which is constituted by the provided adhesive 21, and has a finished adhesive force of 4 to 30 N / 25 mm width and a thickness of 20 to 1500 μm. Layer,
The pressure-sensitive adhesive 21 of the pressure-sensitive adhesive layer 20 is coated with a pressure-sensitive adhesive composition 21 ′ having a viscosity of 500 to 50,000 cps on the window frame 30 and in the window frame 30 from one or both sides of the window frame 30. Thereafter, it is an acrylic, urethane, or silicone-based pressure-sensitive adhesive formed by curing and having an elongation of 100 to 1400% and a light transmittance of 80% or more (claim 2).

  In this specification, “adhesive” means a viscoelastic body having a predetermined adhesive strength, elongation, etc., cured by a crosslinking reaction, drying, or other methods. The state before becoming an “agent”, that is, the state before curing, is referred to as “adhesive composition” to be distinguished.

  In the double-sided pressure-sensitive adhesive sheet 20 ′ or the protective sheet 1 having the above-described configuration, as the colored layer constituting the window frame 30, a resin composition (printing ink) colored on a transparent film as the base material 50 is formed into 1 to 5 layers. It is possible to use an acrylic, urethane, or polyester resin film that is formed by printing or forming a film by a cast method and having a solid content thickness of 5 to 50 μm and a breaking elongation of 0 to 400%. (Claim 3).

  When using the transparent film 50 as the base material, an adhesive layer is formed on the printed layer side and the back surface of the base material, and a window frame is interposed between the adhesive layers (FIG. 1 (E)).

  Further, the colored layer constituting the window frame 30 may be formed on the protective cover 10 by printing or coating method (claim 4).

  Further, the pressure-sensitive adhesive layer 20 described above has a rubber hardness of 20 to 90 degrees when measured at a thickness of 6 mm, and is obtained by forming one or more layers of the pressure-sensitive adhesive composition 21 ′. (Claim 5).

  Further, the adhesive strength of the adhesive can be 1 to 40 N / 25 mm width with a thickness of 20 to 300 μm (Claim 6).

  In the configuration of the protective sheet 1 described above, a release layer may be provided on one side of the protective cover 10, and the protective sheet 1 of the present invention may be provided in a rolled state (Claim 7).

  The protective cover 10 may be provided with a light-reflection preventing layer made of metal oxide and a hard coat layer having a hardness of 2 to 8H (Claim 8).

The method for producing a double-sided pressure-sensitive adhesive sheet of the present invention includes:
A method for producing a double-sided pressure-sensitive adhesive sheet 20 ′ for attaching a protective cover 10 to an information display surface of a display panel,
A window frame 30 made of a colored layer formed in a frame shape corresponding to a desired peripheral shape of the information display surface of the display panel is formed on the release surface of the release film 40 (FIG. 2 (A)),
After applying acrylic, urethane or silicone pressure sensitive adhesive composition 21 'having a viscosity of 500 to 50,000 cps on the release surface of release film 40 including on and within window frame 30 [FIG. (B)], curing the pressure-sensitive adhesive composition 21 ′ [FIG. 2 (C)] forming the pressure-sensitive adhesive 21 having an elongation of 100 to 1400% and a light transmittance of 80% or more. A double-sided pressure-sensitive adhesive sheet 20 ′ having a finished adhesive strength of 4 to 30 N / 25 mm width and a thickness of 20 to 1500 μm, in which the window frame 30 is embedded at any position, is characterized in that it is characterized in that:

Another method for producing the double-sided pressure-sensitive adhesive sheet of the present invention is as follows.
A method for producing a double-sided pressure-sensitive adhesive sheet 20 ′ for attaching a protective cover 10 to an information display surface of a display panel,
A window frame 30 made of a colored layer formed in a frame shape corresponding to a desired peripheral shape of the information display surface of the display panel is formed on the release surface of the release film 40 (FIG. 3A),
After applying an acrylic, urethane or silicone pressure sensitive adhesive composition 21 'having a viscosity of 500 to 50,000 cps on the release surface of the release film 40 including the inside of the window frame 30 and the inside of the window frame 30 [FIG. (B)], the first pressure-sensitive adhesive 211 obtained by curing the pressure-sensitive adhesive composition 21 ′ (FIG. 3C), and the first pressure-sensitive adhesive 211 exposed by peeling the release film 40. After applying the pressure-sensitive adhesive composition 21 'on the surface of the adhesive [Fig. 3 (D)], the second pressure-sensitive adhesive 212 obtained by curing the pressure-sensitive adhesive composition 21' [Fig. 3 (E)], By forming the adhesive 21 having an elongation of 100 to 1400% and a light transmittance of 80% or more, the window frame 30 is embedded at an intermediate position in the thickness direction, and the finished adhesive force is 4 to 30 N / 25 mm width and thickness 20 ˜1500 μm double-sided PSA sheet 20 ′ That (claim 10).

Moreover, the manufacturing method of the protective sheet 1 of this invention is equipped with the protective cover 10 and the adhesive layer 20 which covers the single side | surface of the said protective cover 10, and sticks it on the information display surface of a display panel via the said adhesive layer 20. In the manufacturing method of the protective cover 1 to be used,
A window frame 30 made of a colored layer formed in a frame shape corresponding to a desired peripheral shape of the information display surface of the display panel is formed on the release surface of the release film 40 (FIG. 2 (A)),
After applying acrylic, urethane or silicone pressure sensitive adhesive composition 21 'having a viscosity of 500 to 50,000 cps on the release surface of release film 40 including on and within window frame 30 [FIG. (B)], the adhesive composition 21 ′ is cured [FIG. 2 (C)], and the adhesive 21 having an elongation of 100 to 1400% and a light transmittance of 80% or more is formed. A double-sided pressure-sensitive adhesive sheet 20 ′ having a finished adhesive strength of 4 to 30 N / 25 mm width and a thickness of 20 to 1500 μm, in which the window frame 30 is embedded at any of the positions,
The double-sided pressure-sensitive adhesive sheet 20 ′, a polyester-based resin film or glass (hereinafter referred to as “glass”) having a thickness of 10 to 300 μm, a light transmittance of 90% or more, and stretched 2 to 10 times in the vertical and horizontal directions. A protective cover 10 (referred to as a “protective cover body”) (a protective cover 10 ′ made of a film in the embodiment) is bonded while being sandwiched between rollers [FIG. The pressure-sensitive adhesive layer 20 is formed (claim 11).

Moreover, another manufacturing method of the protective sheet 1 of the present invention similarly includes a protective cover 10 and an adhesive layer 20 that covers one surface of the protective cover 10, and displays information on the display panel via the adhesive layer 20. In the manufacturing method of the protective cover stuck on the surface,
A window frame 30 made of a colored layer formed in a frame shape corresponding to a desired peripheral shape of the information display surface of the display panel is formed on the release surface of the release film 40 (FIG. 3A),
After applying an acrylic, urethane or silicone pressure sensitive adhesive composition 21 'having a viscosity of 500 to 50,000 cps on the release surface of the release film 40 including the inside of the window frame 30 and the inside of the window frame 30 [FIG. (B)], the first pressure-sensitive adhesive 211 formed by curing the pressure-sensitive adhesive composition 21 ′ [FIG. 3 (C)], and the first pressure-sensitive adhesive 211 exposed by peeling the release film 40. After applying the pressure-sensitive adhesive composition 21 'on the surface of the adhesive [Fig. 3 (D)], the second pressure-sensitive adhesive 212 obtained by curing the pressure-sensitive adhesive composition 21' [Fig. 3 (E)], By forming the adhesive 21 having an elongation of 100 to 1400% and a light transmittance of 80% or more, the window frame 30 is embedded at an intermediate position in the thickness direction, and the finished adhesive force is 4 to 30 N / 25 mm width and thickness 20 To obtain a double-sided pressure-sensitive adhesive sheet 20 ′ of ˜1500 μm,
Protective cover 10 (protective cover body) which is a polyester-based resin film having a thickness of 10 to 300 μm, light transmittance of 90% or more, and stretched 2 to 10 times in the vertical and horizontal directions. 10 ′) is bonded while being sandwiched between rollers [FIG. 3 (F)], whereby the pressure-sensitive adhesive layer 20 is formed by the double-sided pressure-sensitive adhesive sheet 20 ′ (claim 12).

Still another manufacturing method of the protective sheet 1 of the present invention includes a protective cover 10 and an adhesive layer 20 that covers one surface of the protective cover 10, and is attached to an information display surface of a display panel via the adhesive layer 20. In the manufacturing method of the protective cover 1 to be worn,
A window frame 30 composed of a colored layer formed in a frame shape corresponding to a desired peripheral shape of the information display surface of the display panel has a thickness of 10 to 300 μm, a light transmittance of 90% or more, and a vertical and horizontal direction. Are formed on one side of a protective cover 10 (protective cover body 10 ′) which is a polyester resin film stretched 2 to 10 times [FIG. 4 (A)],
An acrylic, urethane, or silicone adhesive composition 21 ′ having a viscosity of 500 to 50,000 cps is applied to the surface of the protective cover 10 (protective cover film 10 ′) including the inside of the window frame 30 and the inside of the window frame 30. After applying [FIG. 4 (B)], the adhesive composition 21 ′ is cured [FIG. 4 (C)] with the adhesive 21 having an elongation of 100 to 1400% and a light transmittance of 80% or more. By forming the adhesive layer 20, the adhesive layer 20 having a finished adhesive strength of 4 to 30 N / 25 mm width and a thickness of 20 to 1500 μm is formed by the adhesive 21 and the window frame 30 (claim 13).

In this case, the window frame 30 may be formed directly on one side of the protective cover 10 (protective cover body 10 ′) by printing or casting on the protective cover 10 (protective cover body 10 ′) ( Claim 14), or
After the adhesive composition 21 'is applied to one side of the protective cover 10 (protective cover film 10') [FIG. 5A] and cured to form the first adhesive 211 [FIG. 5B] ] The previously formed window frame 30 is adhered to the first adhesive 211 [FIG. 5C] The window frame 30 with respect to one side of the protective cover 10 (protective cover film 10 ′). And the adhesive composition 21 ′ applied on and in the window frame 30 transferred to the first adhesive 311 and the window adhesive 30 is cured. The pressure-sensitive adhesive layer 20 may be formed by the pressure-sensitive adhesive obtained (second pressure-sensitive adhesive 212) (claim 15) (FIGS. 5E and 5D).

  Due to the configuration of the present invention described above, the double-sided pressure-sensitive adhesive sheet 20 ′ and the protective sheet 1 of the present invention have a common feature that the adhesive 21 is not distorted. A cavity is hardly generated even with the passage of time on the adhesive surface with the adhesive layer 20, particularly the portion where the window frame 30 is formed, and the adhesive does not have distortion that causes deterioration of optical characteristics. Even when the adhesive sheet 20 ′ or the protective sheet 1 was attached, it was possible to prevent the visibility of information displayed on the information display device from being lowered.

  That is, in the conventional configuration for forming the window frame on the display surface of the information display device, the window frame is formed in advance by a method such as printing on a hard protective cover such as a glass plate or an acrylic plate. Protective cover surface (back side) generated by printing the window frame by deforming the adhesive sheet by vacuum suction or pressurization because the adhesive sheet was applied to the protective cover window frame forming surface As a result of this deformation, the stress (restoring force) remaining in the pressure-sensitive adhesive sheet is released over time due to this deformation, and a cavity is formed. Since it changed irregularly, this caused optical distortion.

  In contrast, in the present invention, the pressure-sensitive adhesive composition 21 ′ having a low viscosity of about 500 to 50,000 cps, which is a precursor of the pressure-sensitive adhesive 21, is applied to the release film 40 or the protective cover film 10 ′. By applying on the window frame 30 and in the window frame 30, the applied pressure-sensitive adhesive composition 21 'spreads uniformly in a state where the steps of the window frame 30 are filled, and is thus applied. The pressure-sensitive adhesive composition is cured to form a pressure-sensitive adhesive 21 having a predetermined elongation and light transmittance, and a double-sided pressure-sensitive adhesive sheet 20 having a predetermined pressure-sensitive adhesive force and thickness by the pressure-sensitive adhesive 21 and the window frame 30. 'Or by forming the pressure-sensitive adhesive layer 20, the pressure-sensitive adhesive 21 obtained does not have any strain associated with deformation in the first place. A cavity is generated according to DOO together with no free adhesive layer distortion is because they do not have even the optical distortion, it has to exhibit excellent properties even optically.

  The protective sheet of the present invention using a polyester resin film stretched at a predetermined thickness, light transmittance, and predetermined stretch rate as the protective cover 10 has flexibility as a whole, so that the It was possible to make it difficult to close.

  In other words, in the conventional configuration in which a hard protective cover such as a glass plate or an acrylic plate is used, the sticking to the information display surface is performed by substantially simultaneously bonding the entire surface as shown in FIG. For this reason, it is easy to close air at the bonding interface and it is difficult to remove the closed air. However, in the protective sheet of the present application, as shown in FIG. Because it is possible to apply pressure while applying pressure, it is easy to apply while releasing the air at the joining interface by moving the position where the linear pressure is applied. Can be reapplied.

  In the conventional configuration in which the glass plate is used as a protective cover, a resin film is further applied to the protective cover to prevent the protective cover from being scattered when the glass plate is broken. In this application, the protective cover 10 is formed of a polyester-based resin film, which eliminates the need for a structure for protecting the protective cover 10 and simplifies the structure. We were able to.

  Furthermore, unlike the configuration in which a space (air layer) for buffering is provided between the protective cover 10 and the glass substrate, this space has an acrylic, urethane, or silicone that has a refractive index close to that of the protective cover 10 or the glass substrate. In the conventional structure in which a gap G is provided between the protective cover and the display surface of the information display device because it is filled with the adhesive layer 20 of the system, the refractive index between the protective cover and the air layer and between the air layer and the substrate glass is It was possible to alleviate the problems such as the occurrence of phenomena such as flares and ghosts caused by the increase in reflectivity due to the difference, and the narrow viewing angle (information displayed on the display from an oblique direction is difficult to read).

  As a result, in the conventional structure, in order to suppress these surface reflections, it was necessary to take anti-reflection measures by performing multilayer sputtering of ITO, which is a rare metal, and other metal oxides. In the present application, even when such a coating film is not provided, reflection on the display surface is prevented and information is easy to see. When the coating film is provided, the visibility can be further improved.

The cross section of the protective sheet of this invention is shown, (A) is a window frame on the adhesive layer surface by the side of a protective cover, (B) is a window frame in the thickness direction middle of an adhesive layer, (C) is peeling film 40. The window frame is printed on the transparent resin film, which is the base material 50, and the window frame composed of the white frame and the parting frame is printed on the surface of the adhesive layer on the protective cover side. Each window frame has a structure embedded in an adhesive layer. It is explanatory drawing which shows the manufacturing method of the protection sheet of this invention, (A) is preparation of the peeling film which formed the window frame, (B) is application | coating of the adhesive composition with respect to the single side | surface of a window frame, (C) is the said. Curing of the pressure-sensitive adhesive composition, (D) indicates the bonding of the double-sided pressure-sensitive adhesive sheet formed in the above (A) to (C) and the protective cover film, respectively. It is explanatory drawing which shows another manufacturing method of the protection sheet of this invention, (A) is preparation of the peeling film which formed the window frame, (B) is application | coating of the adhesive composition with respect to the single side | surface of a window frame, (C) Is the formation of the first pressure-sensitive adhesive by curing the pressure-sensitive adhesive composition, (D) is the re-application of the pressure-sensitive adhesive composition, (E) is the formation of the second pressure-sensitive adhesive by re-curing the pressure-sensitive adhesive composition, (F ) Indicates bonding of the double-sided PSA sheet formed in the above (A) to (E) and the film for the protective cover body. It is explanatory drawing which shows another manufacturing method of the protection sheet of this invention, (A) is formation of the window frame with respect to the film for protective covers, (B) is application | coating of the adhesive composition with respect to the single side | surface of a window frame, (C ) Indicates the curing of the pressure-sensitive adhesive composition. It is explanatory drawing which shows another manufacturing method of the protection sheet of this invention, (A) is application | coating of the adhesive composition with respect to the film for protective covers, (B) 1st adhesive by hardening of the said adhesive composition (C) is transfer of the window frame to the first pressure-sensitive adhesive, (D) is the application of the pressure-sensitive adhesive composition to one side of the window frame, and (E) is the formation of the second pressure-sensitive adhesive by curing the pressure-sensitive adhesive composition. Respectively. Cross-sectional explanatory drawing which shows the attachment state of the protective cover with respect to a display panel (conventional). It is explanatory drawing of the conventional protective cover provided with the window frame, (A) is a top view, (B) is the BB sectional drawing of (A). It is explanatory drawing of the comparison of the sticking method of a protective cover, (A) is the conventional hard, The figure (B) shows the sticking method of the protective cover which has the softness | flexibility in this-application embodiment, respectively.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  In addition, the thickness of the protective cover, protective cover film, window frame, and adhesive layer described in the figure is exaggerated for convenience of explanation and is not a scale reflecting actual dimensions. .

〔overall structure〕
As shown in FIGS. 1A to 1D, the protective sheet 1 of the present invention includes a protective cover 10, a pressure-sensitive adhesive 21 and a pressure-sensitive adhesive layer 20 composed of a decorative window frame 30. One side of the agent layer 20 is provided with a release film 40 or the like attached as necessary.

[Protective cover]
Of the constituent members of the protective sheet 1 of the present invention, the protective cover 10 can be made of glass, but in the embodiment, it is formed of a polyester resin film.

  The polyester resin film used as the protective cover 10 is a biaxially stretched polyester film in terms of dimensional stability, transparency, and hardness. Stretching was 2 to 10 times in the longitudinal and lateral directions, and in this embodiment, biaxially stretched PET was used as the protective cover 10.

  The thickness of the protective cover 10 is in the range of 10 to 300 [mu] m, and is 50 to 200 [mu] m, more preferably 100 to 200 [mu] m, in view of hardness and cutting workability.

The protective cover 10 can be provided with a light reflection preventing layer. In this case, a metal oxide film such as ITO, SiO ₂ , TiO ₂ , ZnO ₂ or the like is formed on one side of the polyester film as a light reflection preventing agent. .

  Such a film may be formed, for example, by sputtering ITO or the like. When the light reflection preventing layer is formed by this method, a highly reliable film such as transparency can be obtained.

On the other hand, since the formation of a metal film by sputtering is difficult in depreciation cost, primer treatment and productivity, as a preferable method in terms of cost, for example, a fine metal oxide such as ITO, SiO ₂ , TiO ₂ , ZnO _{2 is used.} An acrylic or acrylic resin binder is added to the powder to form a solution or emulsion, which is then applied to a polyester film with a gravure coater, spin coater, etc., and the metal film is formed, and this is an antireflection layer. It is also good.

The particle size of ITO, SiO ₂ , TiO ₂ , ZnO ₂ or the like used as an antireflection agent in the wet method is preferably as fine as possible from the viewpoint of transparency, and is preferably 10 to 500 nm. In this case, since the yield is deteriorated due to poor dispersibility and secondary aggregation, particles having a particle diameter of about 1 μm may be used.

  The above-mentioned antireflection layer may be formed on any surface of the polyester film. When the antireflection layer is provided on the surface of the polyester film, the upper surface of the hard coat layer, the hard coat layer described later, You may provide in any between axial stretch polyester-type films. Of course, since the light-coating efficiency is formed by the wet method as described above, the hard coat layer also functions as a primer for the light-reflection preventive layer. Preferably formed.

  On the contrary, from the viewpoint of protecting the light reflection preventing layer, it is preferable to form the light reflection preventing layer on the surface to be polymerized to the pressure-sensitive adhesive layer 20, and the kind of the information display surface to be protected and the protection sheet 1 are pasted. The formation position may be selected according to the purpose of wearing.

  It is preferable to provide a hard coat layer with a hardness of 2 to 8H, and a hard coat agent to be used as a hard coat preferably has a hardness of 4H or more in consideration of scratch resistance. . Since the finish of the hard coat depends on the hardness of the support such as a PET film, if the finish is 2H or more, the above range is added and selected. As an example, a known hard coating agent such as urethane or acrylic is applied in a gravure coater, kiss coater (Meyer bar), etc. in a solid content thickness of 1 to 20 μm, and from 4 to 12 μm in order to prevent photorefractive distortion and curling. Is preferred. If it is too thin, the protective effect is weak, and if it is too thick, the polyester film curls due to the condensation reaction between the photorefractive strain and the hard coat resin, causing a reduction in visibility.

  Note that the upper surface of the hard coat described above (if the anti-reflection film and / or printing layer is formed on the hard coat, on the anti-reflection film or printing layer) is further peeled off for both contamination resistance and fingerprint resistance. It is preferable to apply silicone as an agent. By applying such a release agent, the protective sheet 1 of the present invention can be provided in a state of being rolled up. The releasability of is improved.

[Adhesive layer (double-sided adhesive sheet)]
The pressure-sensitive adhesive layer 20 provided on the protective sheet 1 of the present invention has a window frame 30 formed of a pressure-sensitive adhesive composition 21 ′ that is in a precursor state before becoming a pressure-sensitive adhesive 21 (before curing). This adhesive is formed by a pressure-sensitive adhesive 21 obtained by applying a release film or the above-described protective cover 10 (protective cover body 10 ') and curing it, and a window frame 30 embedded in the pressure-sensitive adhesive 21. The finished adhesive strength of the layer 20 (adhesive strength in a state where the adhesive 21 and the window frame 30 are combined) is 4 to 30 N / 25 mm width and thickness is 20 to 1500 μm.

  As will be described later, the pressure-sensitive adhesive layer 20 may be formed directly on the protective cover 10 described above to form the protective sheet 1 of the present invention, or in the manufacturing process of the protective sheet 1, The double-sided pressure-sensitive adhesive sheet 20 ′ of the present invention to be the pressure-sensitive adhesive layer 20 is manufactured in advance, and the double-sided pressure-sensitive adhesive sheet 20 ′ is bonded to the protective cover 10 to form the protective sheet 1.

[Adhesive]
As described above, the above-mentioned pressure-sensitive adhesive 21 which is one of the materials constituting the above-mentioned pressure-sensitive adhesive layer 20 (double-sided pressure-sensitive adhesive sheet 20 ′) is formed by forming the window frame 30 from the pressure-sensitive adhesive composition 21 ′ before curing. It is obtained by applying it to a release film or a protective cover 10 (protective cover body 10 ') and then curing it. Measured with an adhesive 21 (not combined with the window frame 30) at a thickness of 6 mm (adhesive) When the thickness of the layer is 20 to 1500 μm, it is difficult to measure), and a rubber hardness of 20 to 90 degrees and an elongation of 100 to 1400% in the vertical and horizontal directions are used.

  The adhesive strength of the adhesive 21 before being combined with the window frame is in the range of 1 to 40 N / 25 mm width (JIS 0237) with a thickness of 20 to 300 μm.

  The pressure-sensitive adhesive 21 may be a known acrylic as long as it has the above-mentioned adhesive strength, elongation rate, and light transmittance, and can obtain a predetermined elongation rate and thickness when combined with the window frame 30 described later. It is possible to use any of the adhesives based on urethane, urethane, or silicone, but it is preferable to use acrylic based on the point that the haze value is small (the ratio of diffuse transmitted light to the total transmitted light is small). In this embodiment, an acrylic type is used.

  Examples of the pressure-sensitive adhesive composition 21 ′ used to obtain the acrylic pressure-sensitive adhesive 21 include radical polymerization by irradiation with ultraviolet rays without using a medium such as a solution polymerization type or an emulsion type that starts polymerization by heat, or a solvent or water. It is possible to use any of the ultraviolet polymerization types that initiate the process.

  In the case of using the UV-polymerizable pressure-sensitive adhesive composition 21 ', since oxygen in the air inhibits the crosslinking reaction, the ultraviolet ray is blocked in an inert gas atmosphere such as nitrogen gas or in a state where the air is blocked by a gas barrier film. Irradiate.

  As an example of the acrylic pressure-sensitive adhesive composition, acrylic acid monomers and / or oligomers are the main ingredients, and as the main monomers and / or oligomers of acrylic acids, the following can be used as examples. .

Examples of the monomer having a functional group include acrylic acid, methacrylic acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, norbornene dicarboxylic acid, bicyclo [2,2,1] hept-2-ene- Unsaturated carboxylic acids such as 5,6-dicarboxylic acid,
These derivatives include maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylic anhydride, , Aminoethyl (meth) acrylate, propylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, aminopropyl (meth) acrylate, phenylaminoethyl (meth) acrylate, cyclohexyl (meth) acrylate (Meth) acrylic acid alkyl ester derivatives such as aminoethyl, vinylamine derivatives such as N-vinyldiethylamine and N-acetylvinylamine, allylamine derivatives such as allylamine, methacrylamine and N-methylacrylamine, N , N-dimethylacrylamide, N, N Acrylamide derivatives such as dimethylaminopropylacrylamide, acrylamide and N-methylacrylamide, aminostyrenes such as p-aminostyrene, amino group-containing ethylenic groups such as 6-aminohexyl succinimide and 2-aminoethyl succinimide A monomer having a saturated bond can be suitably used as appropriate.

  In addition to these, ethyl acrylate, methyl acrylate, 2-ethylhexyl acrylate, butyl acrylate, isobutyl acrylate, isononyl acrylate, dimethylaminoethyl acrylate, methoxyethyl acrylate, stearyl acrylate, isooctyl acrylate, N-octyl acrylate, 2 hydroxyethyl acrylate, hydroxypropyl acrylate, 2 metroxyethyl methacrylate, butyl methacrylate, 2 hydroxyethyl methacrylate, 2 hydroxypropyl methacrylate, cyclohexyl methacrylate, trimethylolpropane trimethacrylate, For example, tertiary butyl methacrylate can be used.

  These main agents may be used in combination of two or more thereof.

  In order to form a crosslinked structure with respect to the above-mentioned monomer or oligomer, a polyfunctional monomer having two or more functional groups can be suitably used.

  As the polyfunctional monomer, for example, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, Neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, 1,1,1-trishydroxymethylethane diacrylate, 1,1,1-trishydroxymethylethanetri Acrylate, 1,1,1-trishydroxymethylpropane triacrylate, N-methylol acrylate, etc. can be used as appropriate.

  In the case of using an ultraviolet-polymerization type acrylic pressure-sensitive adhesive composition, the pressure-sensitive adhesive composition includes a photopolymerization initiator, an ultraviolet crosslinking accelerator (increase) in addition to the main monomer and / or oligomer of acrylic acid. Auxiliary materials such as sensitizers are blended.

  Other auxiliary materials may include fillers, such as inorganic metal fillers as antireflection agents, vinyl acetate and styrene added for the purpose of modifying hardness and adhesion. , Tackifier (tackifier) and the like may be blended. However, the addition of inorganic metal filler, vinyl acetate, styrene, and tackifier causes birefringence of light in the thickness direction of the obtained pressure-sensitive adhesive layer, thereby reducing the transparency, and particularly the thickness of the pressure-sensitive adhesive layer 20. In the present invention formed to 20 to 1500 μm, the transparency is remarkably lowered. Therefore, it is preferable not to add them or to keep them in a relatively small amount.

  The main component of the pressure-sensitive adhesive composition 21 'may be used in combination of two or more components as long as the light transmittance is 80% or more in consideration of compatibility. In addition, in order to obtain followability (wetability) to the coated surface, the viscosity of the pressure-sensitive adhesive composition 21 'is in the range of 500 to 50,000 cps, and the purpose is to improve the accuracy of film thickness and to apply thinly. In order to reduce the viscosity, it may be diluted with a solvent and applied.

  However, when a solvent is used, it is preferable that the pressure-sensitive adhesive composition 21 ′ is dried with hot air or the like, and the residual solvent in the obtained pressure-sensitive adhesive is 1% or less, more preferably 0.1%. The following. Such residual solvent generates outgas (bubbles) and may cause a decrease in conductivity of the electrode surface in a touch panel display panel.

〔Window frame〕
It constitutes the other constituent material of the pressure-sensitive adhesive layer 20 (double-sided pressure-sensitive adhesive sheet 20 ′), and is disposed in a state where it is embedded in the front surface, back surface, or intermediate position in the thickness direction of the pressure-sensitive adhesive layer 20 (double-sided pressure-sensitive adhesive sheet 20 ′). The aforementioned window frame 30 can be formed of an acrylic, polyester, or urethane colored layer, and is preferably formed of the same component as that of the pressure-sensitive adhesive layer 20 to prevent delamination. It is preferable.

  The resin film used as the window frame 30 may be formed of a single layer, or may be formed of a multilayer structure as long as delamination does not occur.

  The resin film used as the window frame 30 can be colored by various colors. The main body color of the smartphone in addition to the black or white window frame generally used in applications such as smartphones and tablet PCs. It may be a color or metallic color corresponding to, or a combination of these.

  The window frame 30 that is generally employed in currently marketed smartphones or the like is generally black or white and has a light concealing property. For example, for the purpose of improving decorativeness. All or part of the window frame 30 may be colored with a light-transmitting metallic color or fluorescent color.

  For example, black colorant (pigment or dye) can be preferably used as black carbon powder, and white colorant should preferably be white powder such as titanium oxide, aluminum hydroxide, calcium carbonate. Can do.

  When the window frame 30 is formed in white, the boundary between the inner peripheral edge of the window frame 30 and the display image becomes unclear. Therefore, in order to give a sharp impression to the window frame 30, the inner peripheral edge of the white window frame 31 is A black parting frame 32 may be formed (see FIG. 1D).

  The particle size of the coloring powder is 0.1 to 80 μm and 1 to 50 μm from the dispersibility, and the particle size is preferably 20 μm or less from the gloss of the film, more preferably 1 to 5 μm, and the particle shape is needle-like Spherical shape may be used, but an indefinite shape is more preferable from the viewpoint of dispersibility and light hiding.

  Such a colored layer may be formed on a process film such as the release film 40, or may be formed on the protective cover body 10 'described above.

  Further, the shape of the window frame 30, that is, the outer peripheral shape corresponding to the outer shape of the display panel display surface and the inner peripheral shape corresponding to the display range are applied to the entire surface of the process film such as the release film 40, for example. A colored layer may be formed and half-cut so as not to punch the release film 40 to form a desired shape, or the release film 40 or the above-described protective cover (protective cover body) 10 ′), the film may be formed directly by printing in a frame shape.

  The colored layer can be formed by printing a window frame of a desired shape on the acrylic, polyester, or urethane transparent film.

〔Production method〕
As shown in FIGS. 1A to 1D, the window frame 30 described above is embedded in the adhesive 21 at any one of the front surface, the back surface, and the middle position in the thickness direction of the adhesive layer 20. It is arranged in the state.

  In order to enable the window frame 30 to be embedded in the pressure-sensitive adhesive layer 20, in the protective sheet 1 of the present invention, on the window frame 30 and in the window frame 30 from one side or both sides of the window frame 30. The above-mentioned pressure-sensitive adhesive 21 is obtained by applying the above-mentioned pressure-sensitive adhesive composition 21 'and curing it.

  In forming the pressure-sensitive adhesive layer 20, the double-sided pressure-sensitive adhesive sheet 20 ′ of the present invention in which the window frame 30 is embedded is once manufactured in the manufacturing process of the protective sheet 1, and the double-sided pressure-sensitive adhesive sheet 20 ′. The double-sided pressure-sensitive adhesive sheet 20 ′ after bonding may be used as the pressure-sensitive adhesive layer 20 by bonding the film to the stretched polyester film 10 ′ that forms the protective cover 10, or the window frame 30 and the pressure-sensitive adhesive 21 may be protected. It is good also as what manufactures the protection sheet 1 without manufacturing double-sided adhesive sheet 20 'in a manufacture process by laminating and forming on one side.

  When the double-sided pressure-sensitive adhesive sheet 20 ′ is manufactured in advance, the window frame 30 is formed on the release film 40 and formed by applying a pressure-sensitive adhesive composition to the release film. In the case of manufacturing the protective sheet 1 without forming ', a window frame 30 is formed on the protective cover 10 (the protective cover body 10' before being cut in the case of continuous manufacturing), and this window frame The above-mentioned pressure-sensitive adhesive layer 20 is obtained by applying the pressure-sensitive adhesive composition 21 ′ to the surface of the protective cover 10 (protective cover body 10 ′) on which 30 is formed and then curing it.

  As a method for forming such a pressure-sensitive adhesive layer 20 (double-sided pressure-sensitive adhesive sheet 20 ′), a release film 40 having a window frame 30 previously formed on its surface is prepared [FIG. 2 (A)]. The adhesive composition 21 ′ is applied to the surface of the window frame 30 (FIG. 2B), and then the adhesive composition 21 ′ is cured to form the adhesive layer 20 [FIG. ]], Or a pressure-sensitive adhesive layer 20 (double-sided pressure-sensitive adhesive sheet 20 ') having a window frame 30 embedded on one side may be obtained.

  Further, the pressure-sensitive adhesive 21 formed by the above method is used as a first pressure-sensitive adhesive 211 (FIGS. 3A to 3C), and the pressure-sensitive adhesive 211 is further exposed on the surface exposed by peeling off the release film 40 from the pressure-sensitive adhesive 211. After applying the composition 21 ′ [FIG. 3 (D)], this is cured to form the second adhesive 212 [FIG. 3 (E)], and both by the first and second adhesives 211, 212 The double-sided pressure-sensitive adhesive sheet 20 ′ may be formed by the formed pressure-sensitive adhesive 21 and the window frame 30 embedded in the pressure-sensitive adhesive 21 at an intermediate position in the thickness direction.

  As described above, the adhesive composition 21 ′ having a low viscosity before curing is applied to the window frame 30, so that the applied adhesive composition 21 ′ is a step portion formed by the formation of the window frame 30. Since the air is expelled and enters this portion with certainty, the pressure-sensitive adhesive 21 is formed in the shape of the window frame 30 by curing the pressure-sensitive adhesive composition 21 ′ thus applied to form the pressure-sensitive adhesive 21. It is possible to obtain a pressure-sensitive adhesive 21 that has a shape that exactly matches (a shape in which the window frame 30 is embedded) and that does not generate distortion.

  The double-sided pressure-sensitive adhesive sheet 20 ′ formed as described above is then bonded to the protective cover body 10 ′ [FIG. 2 (D); FIG. 3 (F)] and cut to a predetermined size as required. By doing so, the protective sheet 1 of the present invention shown in FIGS. 1 (A) to 1 (D) including the pressure-sensitive adhesive layer 20 formed by the double-sided pressure-sensitive adhesive sheet 20 ′ can be obtained.

  In addition, although illustration is abbreviate | omitted, when a colored layer is formed in the base film 50 by printing, an adhesive layer is formed in the colored layer 30 side of the base film 50 and the back surface of the base material similarly to the above. Is done.

  When the protective cover film 10 ′ and the double-sided pressure-sensitive adhesive sheet 20 ′ are bonded together, as shown in FIG. 2D or FIG. 3F, the protective cover film 10 ′ and the double-sided pressure-sensitive adhesive sheet 20 ′ While sandwiching the bonding start position between two rolls and passing linearly through the rolls, the air between the protective cover film 10 ′ and the double-sided pressure-sensitive adhesive sheet 20 ′ is removed. , Both can be pasted together.

  Although illustration is omitted, in the case of using the ultraviolet-crosslinking acrylic resin-based pressure-sensitive adhesive composition 21 ′, is ultraviolet irradiation performed on the pressure-sensitive adhesive composition 21 ′ under an inert gas atmosphere such as nitrogen gas? Alternatively, the pressure sensitive adhesive composition 21 'is covered with a gas barrier film.

  In the example described above, the double-sided pressure-sensitive adhesive sheet 20 ′ in which the window frame 30 is embedded is formed in advance, and this double-sided pressure-sensitive adhesive sheet 20 ′ is laminated with the protective cover film 10 ′ to protect the present invention. Although the method for obtaining the sheet 1 has been described, the production of the protective sheet 1 of the present invention is performed by preparing a protective cover body 10 ′ in which the window frame 30 is formed in advance by printing or the like, and sticking to the protective cover body 10 ′. The adhesive composition 21 'was applied [FIG. 4 (B)], and then the adhesive composition 21' was cured [FIG. 4 (C)], and the adhesive layer 20 having the window frame 30 embedded on one side. By forming the protective sheet 1 having a laminated structure with the protective cover 10 and having the structure shown in FIG. 1A, the above-mentioned double-sided pressure-sensitive adhesive sheet 20 ′ can be protected without being formed in the middle of the manufacturing process. The sheet 1 may be obtained.

  Further, as described above, the formation of the window frame 30 on the protective cover body 10 ′ is not limited to printing directly on the film 10 ′ forming the protective cover body. For example, the adhesive composition is applied to the film 10 for the protective cover. After the material 21 ′ is applied, it is cured to form the first adhesive 211 (FIGS. 5A and 5B), and this first adhesive 211 is previously formed on the surface of the release film. The window frame 30 was transferred [FIG. 5 (C)], and then the pressure-sensitive adhesive composition 21 ′ was further applied on the first adhesive 211 to which the window frame 30 was transferred [FIG. 5 (D)]. By curing this to form the second adhesive 212, the adhesive layer 20 in which the window frame 30 is embedded between the first adhesive 211 and the second adhesive 212 is laminated on the protective cover film 10 ′. It is also possible to obtain the protective sheet 1 having the structure shown in FIG. .

  The protective sheet 1 formed as described above is attached by attaching the adhesive layer 20 to the information display surface of the display panel.

  The protective sheet 1 of the present invention uses a hard protective cover such as a glass plate or an acrylic plate because all of the protective cover 10, the adhesive layer 20, and the window frame 30 constituting the protective sheet 1 require flexibility. As shown in FIG. 8 (A) in the conventional structure that has been used, it is attached by surface contact, whereas in the protective sheet of the present application, as shown in FIG. 8 (B). By gradually sticking from the end to the end, it is possible to perform the bonding while suitably excluding air existing between the glass substrate and the pressure-sensitive adhesive layer.

Production Example [Example 1]
(1) Manufacture of window frame 3 parts by weight of black carbon (Toyo Ink “Multi-Rack (Black)”) per 100 parts by weight of polyester resin “Byron” (Toyobo “Polyester resin product name NO Byron 50AS”) The raw material resin blended and stirred with an extruding die coater is used so that the final solid thickness is 10 μm on the release surface of the release film (stretched polyester film with one side peeled; thickness 38 μm, width 1200 mm) Cast and dry.

  In order to eliminate pin-holes and increase the light concealment degree, the raw material resin is further cast on the raw material resin layer after drying by the same method and then dried to form a color for forming a window frame having a thickness of 20 μm. A layer was formed.

  After cutting the colored layer formed on the release film by the above method to half the width, it is half-cut into a 70mm x 120mm rectangle so that the release film is not punched with a continuous press equipped with a punching die (big blade). The window frame 30 for smartphones was formed on the peeling surface of the peeling film 40 by cutting (half-cutting) and removing unnecessary portions [see FIG. 2 (A)].

(2) Formation of pressure-sensitive adhesive layer (double-sided pressure-sensitive adhesive sheet) A photopolymerization initiator (manufactured by Ciba Special Chemical Co., Ltd.) was added to acrylic syrup in which 30 parts by weight of butyl acrylate was added to 100 parts by weight of 2-ethylhexyl acrylate. "Irgacure 184") 0.2 parts by weight and UV crosslinking accelerator ("M-5A" manufactured by Soken Chemical Co., Ltd.) 0.5 parts by weight were gradually added and stirred. did.

  The above-mentioned pressure-sensitive adhesive composition 21 'is extruded from a die coater and applied onto the peeling surface of the above-mentioned peeling film 40 on which the window frame 30 is formed [see FIG. A pressure-sensitive adhesive layer 20 (double-sided pressure-sensitive adhesive sheet 20) having a thickness of 50 μm, which is laminated with a gas barrier film (not shown) which is a film (thickness 38 μm) and cured by crosslinking with ultraviolet irradiation in a state where air is blocked. ') Was formed (see FIG. 2C).

The ultraviolet irradiation was performed for 2 to 3 minutes with a UV irradiation apparatus (NEC black light “FL40SBL” 40 W × 2 lamps: a mercury lamp with a wavelength range of 200 to 280 nm / UV irradiation 500 mW / cm ^{2 and a} wavelength of 365 nm).

  The light transmittance of the adhesive 21 portion of the adhesive layer 20 (double-sided adhesive sheet 20 ′) in which the window frame 30 is embedded on one side as described above is 90% or more, and the adhesive peel force is a performance of 25 N / 25 mm width. It was.

(3) Lamination with protective cover From the pressure-sensitive adhesive layer 20 (double-sided pressure-sensitive adhesive sheet 20 ') obtained as described above, the release film 40 is peeled off to expose the window frame embedded surface, and the surface has a hardness of 2H. Attaching a 100μm thick biaxially stretched polyester film with hard coating treatment as a protective cover film 10 'while sandwiching it with two rolls (rubber roll and metal roll) After bonding the two together (see FIG. 2D), the protective sheet 1 of the present invention having the structure shown in FIG.

[Example 2]
After the adhesive composition 21 'was applied to the surface of the release film 40 on which the window frame 30 was formed by the same method as in Example 1 so that the thickness of the solid material was 25 μm, it was covered with a gas barrier film (not shown) and irradiated with ultraviolet rays. Irradiated and cured to form a first adhesive 211 having a window frame 30 embedded on one side [see FIGS. 3A to 3C].

  The release film 40 is peeled off from the window frame embedded surface of the first adhesive 211, and the adhesive composition 21 'is applied to this surface so as to have a solid content thickness of 25 μm [FIG. 3D], not shown. Covering with a gas barrier film and irradiating ultraviolet rays to form the second adhesive 212 [FIG. 3 (E)], the window frame 30 was embedded between the first and second adhesives 211 and 212, thickness 50 μm No. PSA layer 20 (double-sided PSA sheet 20 ′) was obtained.

  The pressure-sensitive adhesive composition 21 ′ used for forming the pressure-sensitive adhesive layer 20 (double-sided pressure-sensitive adhesive sheet 20 ′), the coating method, and the ultraviolet irradiation method are the same as in Example 1.

  The pressure-sensitive adhesive layer 20 (double-sided pressure-sensitive adhesive sheet 20 ′) formed as described above was bonded to the same protective cover body film 10 ′ as in Example 1 by the same method [FIG. 3 (F)], By cutting the obtained laminated body at the outer peripheral position of each window frame 30, the protective sheet 1 of the present invention having the structure shown in FIG. 1 (B) was obtained.

Example 3
(1) Manufacture of window frame 5 parts by weight of white titanium (Toyo Ink “Multirack (White)”) per 100 parts by weight of polyester resin “Byron” (Toyobo “Polyester resin product name NO Byron 50AS”) Example 1 is the same as in Example 1 except that a raw material resin blended and stirred is used.

(2) Formation and lamination of pressure-sensitive adhesive layer Pressure-sensitive adhesive in which 0.5 parts by weight of isocyanate (“Coronate L” manufactured by Nippon Polyurethane) is mixed with 100 parts by weight of a solution-type acrylic pressure-sensitive adhesive (“# 1330” manufactured by Soken Chemical) The agent composition 21 ′ was applied to one side of the same protective cover body 10 ′ as in Example 1 so that the solid thickness was 25 μm [see FIG. 5 (A)], and then dried with hot air (100 to 120 ° C.). Thus, the first pressure-sensitive adhesive 211 was formed (see FIG. 5B).

  After the release film 40 having the window frame 30 formed thereon was bonded to the surface of the first pressure-sensitive adhesive 211 in the same manner as described in Example 1, the release film 40 was removed to remove the window frame 30. After the transfer (see FIG. 5C), the pressure-sensitive adhesive composition 21 ′ was further applied on the first pressure-sensitive adhesive 211 to a solid content thickness of 25 μm (see FIG. 5D), and then dried with hot air (100 to 120 ° C.) to form the second adhesive 212 [see FIG. 5E], and the adhesive layer 20 in which the window frame 30 is embedded between the first and second adhesives 211 and 212. Formed.

  By cutting the laminated body of the protective cover body 10 ′ and the adhesive layer 20 thus obtained at the outer peripheral position of each window frame 30, the protective sheet 1 having the structure shown in FIG. It was.

Example 4
(1) Formation of window frame What formed the window frame 30 by printing directly on the surface of the stretched polyester film which is film 10 'for protective cover bodies was prepared [refer to Drawing 4 (A)].

  The protective cover film 10 ′ here is the same as that used in Example 1 except that the thickness is 150 μm and the width is 250 mm × the length is 450 mm.

  The formed window frame 30 is formed by printing a black parting frame 32 on the inner periphery of the white frame 31 (see FIG. 1D). The white frame 31 is made of polyester resin “Byron” (Toyobo Co., Ltd.). A white material prepared by mixing 10 parts by weight of titanium white (“Multilac (White)” manufactured by Toyo Ink) with 100 parts by weight of “Polyester resin trade name NO Byron 50AS” manufactured by silk printing was formed.

  The size of the white frame 31 is a rectangular shape with an outer dimension of 50 mm × 90 mm and an inner dimension of 44 mm × 77 mm, and a total of 12 rows of 6 rows in two rows with the width direction of the protective cover film as the length direction are solid. After printing so that the partial thickness was 10 μm, it was dried and this operation was repeated twice to form a white frame with a total thickness of 30 μm.

  The above-described black parting frame 32 is printed and formed inside the white frame 31 formed as described above, and the window frame 30 is formed as a whole.

  The parting frame 32 is formed by adding 15 parts by weight of carbon black (Toyo Ink "Multirack (Black)") to 100 parts by weight of polyester resin "Byron" (Toyobo "Polyester resin product name NO Byron 50AS"). By repeating silk printing on the black material mixed and mixed with the same part as in the white frame 31, a rectangular frame having a total thickness of 30 μm, an outer dimension of 49 mm × 79 mm, and an inner dimension of 42 mm × 75 mm was printed.

  If the inner dimension of the white frame 31 and the inner dimension of the parting frame 32 are the same dimension, a sudden step of 60 μm in total consisting of 30 μm of the white frame and 30 μm of the parting frame occurs on the surface of the protective cover. However, in this embodiment, the outer dimension of the parting frame 32 is formed larger than the inner dimension of the white frame 31, and the inner dimension of the parting frame 32 is smaller than the inner dimension of the white frame 31, By extending the parting frame 32 inside the overlapping portion of the white frame 31 having a width of 0.5 mm and the parting frame 32, a step with the surface of the protective cover 10 is formed as shown in FIG. Only the formation part (30 μm) was changed in a stepwise manner to the overlapping part (60 μm) of the parting frame 32 and the white frame 31.

(2) Formation of pressure-sensitive adhesive layer The pressure-sensitive adhesive composition 21 ′ described in Example 1 was applied to the window frame forming surface of the protective cover film 10 ′ on which the window frame 30 was printed as described above. In the same manner as above, that is, after extrusion coating from a die coater (see FIG. 4 (B)), a gas barrier film (not shown) is laminated and irradiated with ultraviolet rays in a state of blocking air to be cured by crosslinking. After forming the 50 μm pressure-sensitive adhesive layer 20 (see FIG. 4C), the protective sheet 1 having the structure shown in FIG. 1D was obtained by cutting at the outer peripheral position of each window frame 30.

[Comparative Example]
In the same manner as in Example 4, by printing on the protective cover film 10 ′, the protective cover 10 on which the window frame 30 composed of the combination of the white frame 31 and the parting frame 32 was printed was obtained and prepared in advance. A protective cover was manufactured by laminating an adhesive sheet (adhesive layer).

  The pressure-sensitive adhesive sheet used for bonding to the protective cover 10 was obtained by using the pressure-sensitive adhesive composition used in Example 1 as a process film (stretched polyester film with one side peeled; thickness 38 μm) using an extrusion die coater. , Width 1200 mm) on the peeled surface to a solid content of 50 μm, and the coated adhesive composition was laminated with a peeled PET film (thickness 38 μm) as a gas barrier film, and then irradiated with ultraviolet rays. The polymerization was started and then left for 24 hours. This pressure-sensitive adhesive sheet was bonded to the window frame forming surface of the protective cover film.

  The method of laminating the protective cover film and the adhesive sheet is the same as the method described in Example 1, and the laminate obtained by this laminating was cut at the outer peripheral position of each window frame and compared. An example protective sheet was obtained.

Evaluation test (load test)
The protective sheets of Examples 1 to 4 and Comparative Example manufactured as described above were each attached to a glass plate, and a roll loaded with a load of 2 kg was reciprocated once on the surface of the protective sheet and a load of 5 kg was applied. The roll was reciprocated twice and allowed to stand at room temperature (23 ° C.) for 24 hours, and then the condition after being left for 24 hours in an environment of 60 ° C. and 90% humidity was observed with the naked eye.

  As a result of observation, none of the test pieces of Examples 1 to 4 could observe bubbles, cavities, delamination, and distortion.

  On the other hand, in the test piece of the comparative example, occurrence of defects was confirmed in 7 out of 8 test pieces.

  Among the seven defects confirmed in the test piece of the comparative example, three were those in which bubbles were generated at the entire interface between the protective cover and the adhesive sheet, and those in which the stepped portion at the inner peripheral edge of the window frame was peeled off In the remaining one, no bubbles or cavities were observed, but a pattern (distortion of the transmission image) was generated due to deformation distortion of the adhesive sheet.

  From the above results, in the configuration where the pre-manufactured adhesive sheet is attached to the protective cover where a minute step is generated because the window frame is printed, the deformation generated in the step portion is completely By trying to restore without yielding, it is considered that voids and strain are likely to occur at the interface between the pressure-sensitive adhesive sheet and the protective cover due to the addition of external force and temperature change.

  As a result, especially when used to protect touch panel type display panels where pressure is always applied to the adhesive sheet during operation, such as smartphones and tablet PCs, voids and distortion may be noticeably generated. is expected.

Observation with a microscope Not only the protective sheets of Examples 1 to 4 but also the protective sheet of the comparative example in the state before applying the load described above, the generation of cavities could not be confirmed by visual observation.

  Therefore, by observing the state near the inner edge of the window frame using an optical microscope and observing the cross section of the protective sheet using a confocal laser microscope, a minute cavity that may be missed by the naked eye is observed. The presence or absence of was observed.

  As a result of the observation, it was confirmed that in the protective sheet of the comparative example, in all of the observed protective sheets, a minute cavity that could be overlooked by the naked eye was generated at a position around 300 μm from the inner periphery of the window frame. This part is considered to be a starting point for generating a large cavity between the protective cover and the adhesive sheet over time.

  On the other hand, in the protective sheets of Examples 1 to 4, it is impossible to confirm even the presence of minute cavities that cannot be observed with the naked eye by either observation with an optical microscope or cross-sectional observation with a confocal laser microscope. However, it was confirmed that cavities and delamination are unlikely to occur.

1 Protective sheet 10 Protective cover 10 'Protective cover body (film or sheet for protective cover)
DESCRIPTION OF SYMBOLS 20 Adhesive layer 20 'Double-sided adhesive sheet 21 Adhesive 211 1st adhesive 212 Second adhesive 21' Adhesive composition 30 Window frame 31 White frame 32 Parting frame 40 Release film 50 Base material (transparent film)
DESCRIPTION OF SYMBOLS 110 Protective cover 120 Spacer 121 Adhesive tape 130 Window frame 150 Display main body 151 Glass substrate 152 Transparent electrode 153 Liquid crystal 154 Backlight

Claims (15)

A double-sided adhesive sheet for attaching a protective cover to the information display surface of the display panel,
A window frame composed of a colored layer formed in a frame shape corresponding to a desired peripheral shape of the information display surface of the display panel, and a pressure-sensitive adhesive provided on and in the window frame; The window frame is embedded at any position on the back surface or in the middle of the thickness direction, and the finished adhesive force is 4 to 30 N / 25 mm width and the thickness is 20 to 1500 μm.
The adhesive is formed by applying and curing an adhesive composition having a viscosity of 500 to 50,000 cps on the window frame and in the window frame from one side or both sides of the window frame. A double-sided pressure-sensitive adhesive sheet for an information display surface, characterized in that it is an acrylic, urethane-based, or silicone-based pressure-sensitive adhesive having 1400% and light transmittance of 80% or more. In the protective sheet that includes a protective cover and an adhesive layer that covers one side of the protective cover, and is attached to the information display surface of the display panel via the adhesive layer,
The protective cover is a polyester resin film or glass having a thickness of 10 to 300 μm, a light transmittance of 90% or more, and stretched 2 to 10 times in the vertical and horizontal directions.
The adhesive layer is a window frame formed of a colored layer formed in a frame shape corresponding to a desired peripheral shape of the information display surface of the display panel, and an adhesive provided on and in the window frame A layer having a finished adhesive strength of 4 to 30 N / 25 mm width and a thickness of 20 to 1500 μm, which is composed of an agent, embedded in the window frame at any position in the front, back, or thickness direction;
The pressure-sensitive adhesive of the pressure-sensitive adhesive layer is formed by applying and curing a pressure-sensitive adhesive composition having a viscosity of 500 to 50,000 cps on and in the window frame from one or both sides of the window frame. An information display surface protective sheet, which is an acrylic, urethane, or silicone adhesive having an elongation of 100 to 1400% and a light transmittance of 80% or more.   The colored layer constituting the window frame is formed by printing a resin composition colored on a transparent film as a substrate on 1 to 5 layers, or by forming a film by a casting method. 3. The double-sided pressure-sensitive adhesive sheet for information display surfaces according to claim 1, wherein the double-sided pressure-sensitive adhesive sheet is an acrylic, urethane-based, or polyester-based resin film having an elongation at break of 0 to 400%. Information display surface protection sheet.   The double-sided pressure-sensitive adhesive sheet for an information display surface according to claim 1, or the information display according to claim 2, wherein the colored layer constituting the window frame is formed on the protective cover by printing or coating method. Surface protection sheet.   The rubber hardness of the pressure-sensitive adhesive layer when measured at a thickness of 6 mm is 20 to 90 degrees, and is obtained by forming one or a plurality of layers of the pressure-sensitive adhesive composition. A double-sided pressure-sensitive adhesive sheet for an information display surface according to claim 2 or an information display surface protection sheet according to claim 2.   The double-sided pressure-sensitive adhesive sheet for information display surfaces according to claim 1, or the information display surface protection sheet according to claim 2, wherein the pressure-sensitive adhesive has a thickness of 20 to 300 µm and a width of 1 to 40 N / 25 mm.   The information display surface protective sheet according to claim 2, wherein the protective cover has a release layer on one side and is wound into a roll.   The information display surface protection sheet according to claim 2, wherein the protective cover includes a light-reflection preventing layer made of metal oxide and a hard coat layer having a hardness of 2 to 8H. A method of manufacturing a double-sided pressure-sensitive adhesive sheet for attaching a protective cover to an information display surface of a display panel,
Forming a window frame comprising a colored layer formed in a frame shape corresponding to a desired peripheral shape of the information display surface of the display panel on the release surface of the release film;
An acrylic, urethane, or silicone adhesive composition having a viscosity of 500 to 50,000 cps is applied to the release surface of the release film including on and inside the window frame, and then the adhesive composition is cured. By forming an adhesive with an elongation of 100 to 1400% and a light transmittance of 80% or more, the window frame is embedded at either the front or back position, and the finished adhesive strength is 4 to 30 N / 25 mm width. A method for producing a double-sided pressure-sensitive adhesive sheet for information display surfaces, characterized in that the double-sided pressure-sensitive adhesive sheet has a thickness of 20 to 1500 μm. A method of manufacturing a double-sided pressure-sensitive adhesive sheet for attaching a protective cover to an information display surface of a display panel,
Forming a window frame comprising a colored layer formed in a frame shape corresponding to a desired peripheral shape of the information display surface of the display panel on the release surface of the release film;
An acrylic, urethane, or silicone adhesive composition having a viscosity of 500 to 50,000 cps is applied to the release surface of the release film including on and inside the window frame, and then the adhesive composition is cured. The first pressure-sensitive adhesive obtained by applying the pressure-sensitive adhesive composition to the surface of the first pressure-sensitive adhesive exposed by peeling off the release film, and then curing the pressure-sensitive adhesive composition. By forming a pressure-sensitive adhesive composed of a second pressure-sensitive adhesive with an elongation of 100 to 1400% and a light transmittance of 80% or more, the window frame is embedded at an intermediate position in the thickness direction, and a final pressure-sensitive adhesive force of 4 to 30 N / A method for producing a double-sided pressure-sensitive adhesive sheet for information display surfaces, comprising a double-sided pressure-sensitive adhesive sheet having a width of 25 mm and a thickness of 20 to 1500 μm. In the manufacturing method of a protective cover provided with a protective cover and an adhesive layer covering one side of the protective cover, and attached to the information display surface of the display panel through the adhesive layer,
Forming a window frame comprising a colored layer formed in a frame shape corresponding to a desired peripheral shape of the information display surface of the display panel on the release surface of the release film;
An acrylic, urethane, or silicone adhesive composition having a viscosity of 500 to 50,000 cps is applied to the release surface of the release film including on and inside the window frame, and then the adhesive composition is cured. By forming an adhesive with an elongation of 100 to 1400% and a light transmittance of 80% or more, the window frame is embedded at either the front or back position, and the finished adhesive strength is 4 to 30 N / 25 mm width. , To obtain a double-sided pressure-sensitive adhesive sheet having a thickness of 200 to 1500 μm,
A double-sided adhesive sheet and a protective cover made of a polyester resin film having a thickness of 10 to 300 μm and a light transmittance of 90% or more and stretched 2 to 10 times in the vertical and horizontal directions are sandwiched between rollers. The method for producing an information display surface protection sheet, wherein the pressure-sensitive adhesive layer is formed by the double-sided pressure-sensitive adhesive sheet. In the manufacturing method of a protective cover provided with a protective cover and an adhesive layer covering one side of the protective cover, and attached to the information display surface of the display panel through the adhesive layer,
Forming a window frame comprising a colored layer formed in a frame shape corresponding to a desired peripheral shape of the information display surface of the display panel on the release surface of the release film;
An acrylic, urethane, or silicone adhesive composition having a viscosity of 500 to 50,000 cps is applied to the release surface of the release film including on and inside the window frame, and then the adhesive composition is cured. The first pressure-sensitive adhesive formed and the surface of the first pressure-sensitive adhesive exposed by peeling off the release film were applied to the pressure-sensitive adhesive composition, and then the pressure-sensitive adhesive composition was cured. By forming a pressure-sensitive adhesive composed of the second pressure-sensitive adhesive with an elongation of 100 to 1400% and a light transmittance of 80% or more, the window frame is embedded at an intermediate position in the thickness direction, and a final pressure-sensitive adhesive force of 4 to 30 N / A double-sided pressure-sensitive adhesive sheet having a width of 25 mm and a thickness of 20 to 1500 μm was obtained,
The double-sided pressure-sensitive adhesive sheet and a protective cover, which is a polyester resin film having a thickness of 10 to 300 μm, light transmittance of 90% or more, and stretched 2 to 10 times in the vertical and horizontal directions, are sandwiched between rollers. The method for producing an information display surface protection sheet, wherein the pressure-sensitive adhesive layer is formed by the double-sided pressure-sensitive adhesive sheet by pasting together. In the manufacturing method of a protective cover provided with a protective cover and an adhesive layer covering one side of the protective cover, and attached to the information display surface of the display panel through the adhesive layer,
A window frame comprising a colored layer formed in a frame shape corresponding to a desired peripheral shape of the information display surface of the display panel has a thickness of 10 to 300 μm, a light transmittance of 90% or more, and a vertical and horizontal direction. Each is formed on one side of a protective cover which is a polyester resin film stretched 2 to 10 times.
An acrylic, urethane, or silicone adhesive composition having a viscosity of 500 to 50,000 cps is applied to the surface of the protective cover including on and inside the window frame, and then the adhesive composition is cured. By forming an adhesive having an elongation of 100 to 1400% and a light transmittance of 80% or more, the adhesive and the window frame have a finished adhesive force of 4 to 30 N / 25 mm width and a thickness of 20 to 1500 μm. The manufacturing method of the information display surface protection sheet | seat characterized by forming an adhesive layer.   14. The method for manufacturing an information display surface protection sheet according to claim 13, wherein the window frame is formed on one side of the protective cover directly by printing or casting on the protective cover.   After the adhesive composition is applied to one side of the protective cover and cured to form the first adhesive, the previously formed window frame is adhered to the first adhesive and the protective cover The window frame is formed on one side, and the first adhesive, the window frame, and the adhesive composition applied on and in the window frame transferred to the first adhesive are cured. The method for producing an information display surface protection sheet according to claim 13, wherein the pressure-sensitive adhesive layer is formed from the obtained pressure-sensitive adhesive.

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