Colored adhesive sheet and display

Abstract

The present invention provides a colored adhesive sheet capable of improving the design of a display, and a display with improved design. The colored adhesive sheet (1) comprises a colored adhesive layer (11), which satisfies the following formulas (I) to (IV) when the lightness L* of one region R1 of a display component defined by the CIE1976 L*a*b* color system is set to L1, the lightness L* of another region R2 is set to L2, the lightness L* of the region R1 stacked with the colored adhesive layer (11) is set to L1', and the lightness L* of the region R2 stacked with the colored adhesive layer (11) is set to L2': ΔL = L1-L2···(I) ΔL' = L1'-L2'···(II) ΔL > 0···(III) (ΔL' / ΔL) × 100 ≤ 80···(IV).

Description

[0001] The present invention is a divisional application of the Chinese patent application with application number 202010229821.8, application date March 27, 2020, and invention name “Colored Adhesive Sheet and Display Body”. This application claims priority to Japanese Patent Application No. 2019-068290 filed in Japan on March 9, 2019, and Japanese Patent Application No. 2019-171774 filed in Japan on September 20, 2019. Technical Field

[0002] The present invention relates to a colored adhesive sheet for laminating display components, and a display using the colored adhesive sheet. Background Art

[0003] In recent years, image display devices such as liquid crystal display devices or organic electroluminescent devices are increasingly used in display bodies (displays), such as in-vehicle displays installed in automobile dashboards, car navigation systems, various instruments on the console, displays of tablet terminals used by general users, displays of commercial tablet terminals or digital signage, displays of outdoor digital signage, etc.

[0004] As mentioned above, in displays, typically for automotive applications, it is sometimes desirable to enhance the design by creating a sense of unity with surrounding components, such as a frame, when the display is off. To achieve this, coloring the display is a possible approach. For example, Patent Documents 1 to 4 disclose inventions related to coloring displays.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2000-313871

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2009-188298

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 2012-234028

[0010] Patent Document 4: Japanese Patent Application Laid-Open No. 2017-57375 Summary of the Invention

[0011] Technical Problems to be Solved by the Invention

[0012] However, because the coloring techniques disclosed in Patent Documents 1 to 4 each have different purposes, they fail to impart a sense of unity between the display and surrounding components, thereby improving design. Furthermore, because surrounding components vary in type, the adhesive must be tailored to suit each component. This results in limited flexibility in adhesive design and complicates manufacturing management.

[0013] The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide a colored adhesive sheet capable of improving the design of a display, and a display with improved design.

[0014] Technical means to solve technical problems

[0015] In order to achieve the above-mentioned objectives, first, the present invention provides a colored adhesive sheet comprising a colored adhesive layer composed of an adhesive containing a colorant, for attachment to a display component having at least two regions with different brightness in a planar direction, wherein the colored adhesive sheet is characterized in that, when the brightness L* of one region R1 of the display component specified by the CIE1976L*a*b* color system is set to L1, the brightness L* of the other region R2 is set to L2, the brightness L* of the region R1 on which the colored adhesive layer is stacked is set to L1', and the brightness L* of the region R2 on which the colored adhesive layer is stacked is set to L2', the following formulas (I) to (IV) are satisfied (Invention 1).

[0016] ΔL=L1-L2···(I)

[0017] ΔL'=L1'-L2' (II)

[0018] ΔL>0···(III)

[0019] (ΔL' / ΔL)×100≤80···(IV)

[0020] When the colored adhesive sheet of the above invention (Invention 1) is applied to a display, the design of the display when the display is off can be improved, for example, the coordination of the appearance when the display is off can be improved.

[0021] In the above invention (Invention 1), it is preferred that the following formula (V) is further satisfied (Invention 2).

[0022] ΔL'≤30···(V)

[0023] In the above inventions (Inventions 1 and 2), the colored adhesive layer preferably has a lightness L* defined by the CIE 1976 L*a*b* color system of 5 or more and 95 or less (Invention 3).

[0024] In the above inventions (Inventions 1 to 3), it is preferred that the chromaticity a* and chromaticity b* of the colored adhesive layer defined by the CIE 1976 L*a*b* color system are respectively -7 to 7 (Invention 4).

[0025] In the above inventions (Inventions 1 to 4), it is preferred that the total light transmittance of the colored adhesive layer is 30% or more (Invention 5).

[0026] In the above inventions (Inventions 1 to 5), it is preferred that the total light haze value of the colored adhesive layer be 0.5% or more and 40% or less (Invention 6).

[0027] In the above inventions (Inventions 1 to 6), it is preferred that the average haze of a solution prepared by diluting the colorant 10,000 times with ethyl acetate, which is the average of the haze value at a wavelength of 780 nm and the haze value at a wavelength of 380 nm, is 1% or more and 60% or less (Invention 7).

[0028] In the above inventions (Inventions 1 to 7), the difference between the haze value at a wavelength of 780 nm and the haze value at a wavelength of 380 nm of a solution prepared by diluting the colorant 10,000 times with ethyl acetate is preferably 30 percentage points or less (Invention 8).

[0029] In the above inventions (Inventions 1 to 8), it is preferred that the colorant is a black pigment (Invention 9).

[0030] In the above inventions (Inventions 1 to 9), it is preferred that the adhesive is an acrylic adhesive (Invention 10).

[0031] In the above inventions (Inventions 1 to 10), the adhesive is preferably formed by cross-linking an adhesive composition containing a (meth)acrylate polymer (A), a crosslinking agent (B), and a colorant (C) (Invention 11).

[0032] In the above inventions (Inventions 1 to 11), the colored adhesive sheet preferably includes two release sheets and the colored adhesive layer sandwiched between the release sheets so as to contact release surfaces of the two release sheets (Invention 12).

[0033] In the above inventions (Inventions 1 to 12), it is preferable that the colored adhesive sheet is used to bond the display constituent member to a display constituent member different from the display constituent member (Invention 13).

[0034] Second, the present invention provides a display comprising: a first display constituent member having at least two regions of different lightness in a planar direction; a second display constituent member; and a colored adhesive layer bonding the first display constituent member and the second display constituent member to each other, wherein the display is characterized in that, when the lightness L* of one region R1 of the first display constituent member, as defined by the CIE1976 L*a*b* colorimetric system, is set to L1, the lightness L* of the other region R2 is set to L2, the lightness L* of the region R1 on which the colored adhesive layer is stacked is set to L1', and the lightness L* of the region R2 on which the colored adhesive layer is stacked is set to L2', the following formulas (I) to (IV) are satisfied (Invention 14).

[0035] ΔL=L1-L2···(I)

[0036] ΔL'=L1'-L2' (II)

[0037] ΔL>0···(III)

[0038] (ΔL' / ΔL)×100≤80···(IV)

[0039] In the above invention (Invention 14), at least one of the first display constituent member and the second display constituent member may have a step difference on at least the surface on the side to be bonded by the colored adhesive layer (Invention 15).

[0040] In the above inventions (Inventions 14 and 15), a black frame material may be provided (Invention 16).

[0041] Effects of the Invention

[0042] According to the colored adhesive sheet of the present invention, the design of the display can be improved. In addition, the design of the display of the present invention is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a cross-sectional view of a colored adhesive sheet according to one embodiment of the present invention.

[0044] Figure 2 This is a cross-sectional view of a display according to one embodiment of the present invention.

[0045] Figure 3 This is a plan view of a display unit having a frame material according to one embodiment of the present invention.

[0046] Description of Reference Numerals

[0047] 1: Colored adhesive sheet; 11: Colored adhesive layer; 12a, 12b: Release sheets; 2: Display; 21: First display component; 22: Second display component; 3: Printed layer; 4: Frame material. DETAILED DESCRIPTION

[0048] Hereinafter, embodiments of the present invention will be described.

[0049] [Colored adhesive sheet]

[0050] A colored adhesive sheet according to one embodiment of the present invention comprises a colored adhesive layer composed of an adhesive containing a colorant, and is intended for attachment to a display component having at least two areas of differing brightness in a planar direction. The sheet is preferably formed by laminating a release sheet on one or both sides of the colored adhesive layer. The colored adhesive sheet of this embodiment is preferably used to attach the display component to a different display component. The display and display components will be described later.

[0051] Figure 1 Detailed structure of an example of the colored adhesive sheet according to this embodiment is shown in FIG.

[0052] like Figure 1 As shown, the colored adhesive sheet 1 is composed of two release sheets 12a and 12b and a colored adhesive layer 11. The colored adhesive layer 11 is sandwiched between the two release sheets 12a and 12b so as to contact the release surfaces of the two release sheets 12a and 12b. In this specification, the release surface of the release sheet refers to the surface of the release sheet that is releasable, including both surfaces that have been subjected to a release treatment and surfaces that are releasable even without a release treatment.

[0053] 1. Components

[0054] 1-1. Colored Adhesive Layer

[0055] Regarding the lightness L* of the colored adhesive sheet 1 of this embodiment as specified by the CIE1976L*a*b* color system, when the lightness L* of one region R1 of a display body constituent member (adherent) having at least two regions with different lightness in a planar direction is set to L1, the lightness L* of another region R2 is set to L2, the lightness L* of the region R1 on which the colored adhesive layer 11 is stacked is set to L1', and the lightness L* of the region R2 on which the colored adhesive layer 11 is stacked is set to L2', the following formulas (I) to (IV) are satisfied, and preferably the following formula (V) is further satisfied.

[0056] ΔL=L1-L2···(I)

[0057] ΔL'=L1'-L2' (II)

[0058] ΔL>0···(III)

[0059] (ΔL' / ΔL)×100≤80···(IV)

[0060] ΔL'≤30···(V)

[0061] The method for measuring lightness L* in this specification is as described in the test examples below. For the measurement of L1 and L2, the reflected light from the display component is measured. For the measurement of L1' and L2', the reflected light from the incident light on the side of the colored adhesive layer 11 is measured. The display component is preferably black.

[0062] When the colored adhesive layer 11 that satisfies the above conditions is applied to a display body having the above-mentioned display body constituent components, the design of the display body when the display body is turned off can be improved. As an example of this design, the appearance coordination when the lights are turned off can be cited. Specifically, when the display body is turned off, it is not easy to distinguish the boundary between the display portion and its surrounding components, such as the boundary with the black frame material or the black printed layer (seamless). Thus, the overall sense of the display body and the surrounding components when the display body is turned off is improved. In addition, even in the presence of multiple surrounding components (for example, black frame material or black printed layer), it is possible to seek the appearance coordination of the display body and each surrounding component, or the appearance coordination of the surrounding components with each other (seamless). Therefore, since there are many components that can seek appearance coordination, the versatility of the adhesive constituting the above-mentioned colored adhesive layer 11 is high, and the degree of freedom of design is also increased.

[0063] From the above perspectives, the value of (ΔL' / ΔL)×100 needs to be 80 or less, preferably 70 or less, more preferably 60 or less, particularly preferably 50 or less, further preferably 45 or less, and most preferably 40 or less. On the other hand, the lower limit of (ΔL' / ΔL)×100 is not particularly limited, but from the perspective of balancing the visibility of the image and video of the resulting display, it is preferably 10 or more, more preferably 15 or more, particularly preferably 20 or more, and further preferably 30 or more.

[0064] The value of ΔL is the reference value of formula (IV). If the value of ΔL exceeds 0, the lightness L1 of one region R1 of the display component (adherent) differs from the lightness L2 of another region R2. It can be said that the display component has at least two regions of different lightness in the planar direction. Here, the closer the value of ΔL is to 0, the more similar the appearance of regions R1 and R2 of the display component becomes, and the visual evaluation tends to improve the appearance coordination. Conversely, as the value of ΔL increases, it tends to be difficult to control the appearance coordination. Even in such regions where appearance coordination is generally difficult to control, the colored adhesive layer 11 of this embodiment can fully enhance the appearance coordination (design) by satisfying formula (IV).

[0065] As shown in formula (III), the value of ΔL only needs to be greater than 0. However, from the perspective of improving the accuracy of the appearance coordination judgment based on formula (IV), it is preferably 5 or greater, more preferably 10 or greater, particularly preferably 20 or greater, even more preferably 30 or greater, and most preferably 35 or greater. Similarly, from the perspective of improving the accuracy of the appearance coordination judgment, the upper limit of ΔL is preferably 100 or less, more preferably 75 or less, particularly preferably 50 or less, and even more preferably 40 or less.

[0066] As shown in formula (V), from the perspective of improving the appearance harmony of the display, the value of ΔL' is preferably 30 or less, more preferably 25 or less, particularly preferably 20 or less, and even more preferably 15 or less. On the other hand, the lower limit of ΔL' is not particularly limited, but from the perspective of improving the accuracy of the appearance harmony judgment based on formula (IV) and achieving a balance between the visibility of the image and video of the resulting display, it is preferably 1.5 or more, more preferably 3 or more, particularly preferably 4 or more, and even more preferably 5 or more.

[0067] The lightness L* of the colored adhesive layer 11, as defined by the CIE 1976 L*a*b* color system, is preferably 95 or less, more preferably 92 or less, particularly preferably 90 or less, and even more preferably 88 or less. Thus, the above-mentioned formula (IV) (and formula (V)) is easily satisfied. Furthermore, the lightness L* is preferably 5 or more, more preferably 20 or more, particularly preferably 50 or more, even more preferably 70 or more, and most preferably 80 or more. Thus, the above-mentioned formula (IV) (and formula (V)) is easily satisfied, and the visibility of the image and video of the resulting display is easily improved.

[0068] The average haze of the colored adhesive layer 11 of this embodiment, which is the average of the haze value at a wavelength of 780nm and the haze value at a wavelength of 380nm, is preferably 1% or more, particularly preferably 2% or more, further preferably 3% or more, and most preferably 3.2% or more. Thus, it is easy to satisfy the above-mentioned formula (IV) (and formula (V)). In addition, from the perspective of easily satisfying the above-mentioned formula (IV) (and formula (V)), the above-mentioned average haze is preferably 60% or less, more preferably 40% or less, and particularly preferably 30% or less. From the perspective of the visibility of the image and image of the obtained display body becoming good, the above-mentioned average haze is preferably 20% or less, particularly preferably 12% or less, and further preferably 5% or less. In addition, the haze value in this specification is a value measured in accordance with JIS K7136:2000.

[0069] The difference (absolute value) between the haze value at a wavelength of 780 nm and the haze value at a wavelength of 380 nm of the colored adhesive layer 11 of this embodiment is preferably 15 percentage points or less, particularly preferably 10 percentage points or less, and even more preferably 7 percentage points or less. Thus, when the colored adhesive layer 11 of this embodiment is applied to a display, when the display is illuminated, the tonal balance on the screen remains unchanged regardless of the viewing position or angle. As a result, when the display is illuminated, the visibility of images and videos viewed from a wide range of angles (wide-angle visibility) is improved, providing good image quality.

[0070] The lower limit of the difference in the haze value may be 0 percentage points, but from the perspective of being able to easily adjust the average haze to a desired value, it is preferably 1 percentage point or more, more preferably 2 percentage points or more, particularly preferably 3 percentage points or more, and further preferably 4 percentage points or more.

[0071] From the perspective of easily adjusting the above-mentioned average haze, the difference in haze values, and the standard deviation of the haze values described later to desired values, the haze value of the colored adhesive layer 11 of this embodiment at a wavelength of 780 nm is preferably 0.1 to 50%, preferably 0.2 to 25%, more preferably 0.5 to 15%, particularly preferably 0.7 to 7%, and further preferably 1 to 3%.

[0072] In addition, from the perspective of easily adjusting the above-mentioned average haze, the difference in haze values, and the standard deviation of the haze values described later to the desired values, the haze value of the colored adhesive layer 11 of this embodiment at a wavelength of 380 nm is preferably 0.1 to 60%, more preferably 1 to 40%, particularly preferably 2 to 30%, further preferably 4 to 20%, and most preferably 5 to 10%.

[0073] The standard deviation of the haze value at each wavelength (i.e., 380 nm, 385 nm, 390 nm, 775 nm, 780 nm) in the wavelength range of 380 nm to 780 nm of the colored adhesive layer 11 of this embodiment is preferably 5 or less, particularly preferably 3 or less, and further preferably 2 or less. Thus, when the colored adhesive layer 11 of this embodiment is applied to a display, when the display is illuminated, the balance of tones on the screen does not change regardless of the viewing position or angle. As a result, when the display is illuminated, the visibility of images and videos when viewed from a wide range of angles (wide-angle visibility) is improved, providing good image quality.

[0074] The lower limit of the standard deviation is usually 0 or more, but from the perspective of easily satisfying the above formula (IV) (and formula (V)), it is preferably 0.1 or more, more preferably 0.5 or more, particularly preferably 1 or more, further preferably 1.5 or more, and most preferably 1.7 or more.

[0075] The total haze value of the colored adhesive layer 11 of this embodiment is preferably 0.5% or greater, more preferably 1% or greater, particularly preferably 2% or greater, and even more preferably 3% or greater. This facilitates satisfying the above-mentioned formula (IV) (and formula (V)). On the other hand, the total haze value is preferably 40% or less, more preferably 30% or less, particularly preferably 20% or less, even more preferably 10% or less, and most preferably 5% or less. This facilitates improved visibility as a display.

[0076] The total light transmittance (measured in accordance with JIS K7361-1:1997) of the colored adhesive layer 11 of this embodiment is generally 100% or less, preferably 98% or less, more preferably 90% or less, particularly preferably 70% or less, and even more preferably 50% or less. This makes it easy to satisfy the above-mentioned formula (IV) (and formula (V)). On the other hand, the above-mentioned total light transmittance is preferably 30% or more, more preferably 35% or more, particularly preferably 40% or more, and even more preferably 45% or more. This facilitates good visibility as a display.

[0077] Here, as the above-mentioned surrounding components, specifically, a car instrument panel having a lightness L* of 23.2, a chromaticity a* of -0.5, and a chromaticity b* of -1.5 as defined by the CIE 1976 L*a*b* color system can be cited. As the hue of the above-mentioned surrounding components, preferably, the lightness L* is 5 to 90, the chromaticity a* is -40 to 40, and the chromaticity b* is -40 to 40. More preferably, the lightness L* is 10 to 80, the chromaticity a* is -30 to 30, and the chromaticity b* is -30 to 30. More preferably, the lightness L* is 15 to 70, the chromaticity a* is -20 to 20, and the chromaticity b* is -20 to 20. The colored adhesive sheet 1 of this embodiment can be suitably used in a display having a surrounding component having the above-mentioned hue.

[0078] From the perspective of display design, the chromaticity a* of the colored adhesive layer 11 as defined by the CIE 1976 L*a*b* colorimetric system is preferably -7 to 7, more preferably -5 to 5, particularly preferably -3 to 3, and even more preferably -1 to 1. Furthermore, from the perspective of display design, the chromaticity b* of the colored adhesive layer 11 as defined by the CIE 1976 L*a*b* colorimetric system is preferably -7 to 7, more preferably -5 to 5, particularly preferably -3 to 3, and even more preferably -1 to 1. The methods for measuring the chromaticity a* and chromaticity b* in this specification are described in the test examples below.

[0079] By ensuring that the colored adhesive layer 11 satisfies the aforementioned optical properties, when applied to a display, the blackness increases when the display is off, further improving the design of the display (for example, the harmonious appearance when the display is off). Specifically, for displays, especially in-vehicle displays, the overall sense of integration with surrounding components, such as a black frame, can be further improved.

[0080] The above-mentioned optical properties can be achieved by appropriately selecting the type and content of the colorant contained in the adhesive constituting the colored adhesive layer 11 .

[0081] The lower limit of the average haze value of a solution prepared by diluting the colorant 10,000 times with ethyl acetate, which is the average of the haze value at a wavelength of 780 nm and the haze value at a wavelength of 380 nm, is preferably 1% or higher, particularly preferably 2% or higher, and even more preferably 3% or higher. Furthermore, the upper limit of the average haze value of the colorant is preferably 60% or lower, preferably 40% or lower, more preferably 25% or lower, particularly preferably 15% or lower, even more preferably 8% or lower, and particularly preferably 5% or lower from the perspective of maintaining visibility. By using such a colorant in an appropriate amount, the resulting colored adhesive layer 11 easily satisfies the aforementioned optical properties and easily satisfies the aforementioned formula (IV) (and formula (V)).

[0082] Furthermore, the difference between the haze value at a wavelength of 780 nm and the haze value at a wavelength of 380 nm of a solution prepared by diluting the colorant 10,000 times with ethyl acetate is preferably 30 percentage points or less, more preferably 25 percentage points or less, particularly preferably 20 percentage points or less, and even more preferably 14 percentage points or less. By using such a colorant in an appropriate amount, the resulting colored adhesive layer 11 easily satisfies the aforementioned optical properties and easily satisfies the aforementioned formula (IV) (and formula (V)).

[0083] The lower limit of the difference in haze value may be 0 percentage points, but from the perspective of easily satisfying the above-mentioned optical properties and the above-mentioned formula (IV) (and formula (V)) of the obtained colored adhesive layer 11, it is preferably 1 percentage point or more, particularly preferably 4 percentage points or more, and from the perspective of taking visibility into consideration, it is preferably 7.5 percentage points or more.

[0084] The haze value at a wavelength of 780 nm of a solution prepared by diluting the colorant 10,000 times with ethyl acetate is preferably 0.1 to 50%, more preferably 0.5 to 25%, particularly preferably 0.8 to 15%, even more preferably 1 to 3%, and most preferably 2 to 2.5%. Furthermore, the haze value at a wavelength of 380 nm of a solution prepared by diluting the colorant 10,000 times with ethyl acetate is preferably 1 to 60%, more preferably 3 to 30%, particularly preferably 6 to 20%, and even more preferably 10 to 15%. Thus, the resulting colored adhesive layer 11 easily satisfies the aforementioned optical properties and easily satisfies the aforementioned formula (IV) (and formula (V)).

[0085] Furthermore, the standard deviation of the haze value at each wavelength of 5 nm intervals in the wavelength range of 380 nm to 780 nm (i.e., 380 nm, 385 nm, 390 nm, ..., 775 nm, 780 nm) of a solution prepared by diluting the colorant 10,000 times with ethyl acetate is preferably 10 or less, more preferably 6 or less, particularly preferably 3 or less, and even more preferably 1.8 or less. The lower limit of the standard deviation is most preferably 0, and is generally preferably 0.1 or more, more preferably 0.3 or more, particularly preferably 0.5 or more, and even more preferably 1 or more. As a result, the resulting colored adhesive layer 11 easily satisfies the above-mentioned optical properties and easily satisfies the above-mentioned formula (IV) (and formula (V)).

[0086] The colorant may be a pigment or a dye. The pigment may be an inorganic pigment or an organic pigment. Inorganic pigments are preferred from the perspective of the durability of the resulting adhesive. The color of the colorant may be appropriately selected based on the color of the surrounding components to enhance the overall appearance. Dark or deep colors such as black, brown, navy blue, purple, and blue are generally preferred, with black being particularly preferred.

[0087] Examples of the inorganic pigments include carbon black, cobalt pigments, iron pigments, chromium pigments, titanium pigments, vanadium pigments, zirconium pigments, molybdenum pigments, ruthenium pigments, platinum pigments, ITO (indium tin oxide) pigments, and ATO (antimony tin oxide) pigments.

[0088] Examples of organic pigments and organic dyes include amine pigments, cyanine pigments, merocyanine pigments, croconium pigments, squarylium pigments, azulenium pigments, polymethine pigments, naphthoquinone pigments, pyrylium pigments, phthalocyanine pigments, naphthalocyanine pigments, naphtholactam pigments, azo pigments, condensed azo pigments, Indigo pigments, perinone pigments, perylene pigments, dioxazine pigments, quinacridone pigments, isoindolinone pigments, quinolinone pigments, pyrrole pigments, thioindigo pigments, metal complex pigments (metal complex salt dyes), dithiol metal complex pigments, indoxyl pigments, triarylmethane pigments, anthraquinone pigments, dioxazine pigments, naphthol pigments, azomethine pigments, benzimidazolone pigments, pyranthrone pigments, and threne pigments.

[0089] Examples of black pigments include carbon black, copper oxide, ferrosoferric oxide, manganese dioxide, aniline black, activated carbon, etc. Examples of black dyes include high-concentration plant dyes and azo dyes.

[0090] In order to obtain target physical properties, the above-mentioned pigments or dyes may be appropriately mixed and used in the colored adhesive layer 11 .

[0091] Among the above-mentioned colorants, carbon black, aniline black dyes, and chromate black dyes are preferred because they easily satisfy the above-mentioned physical properties and easily create a sense of unity with surrounding components. The surface of the carbon black may or may not be subjected to a prescribed treatment (e.g., a solvophilic treatment).

[0092] The type of adhesive constituting the colored adhesive layer 11 of the colored adhesive sheet 1 of this embodiment is not particularly limited, and may be, for example, any of acrylic adhesives, polyester adhesives, polyurethane adhesives, rubber adhesives, silicone adhesives, etc. Furthermore, the adhesive may be any of an emulsion type, a solvent type, or a solvent-free type, and may be any of a cross-linked type or a non-cross-linked type. Among these, acrylic adhesives are preferred due to their excellent adhesive properties and optical characteristics.

[0093] The acrylic adhesive may be active energy ray-curable or inactive energy ray-curable. A cross-linked acrylic adhesive is preferred, and a thermally cross-linked acrylic adhesive is more preferred.

[0094] Specifically, the adhesive is preferably formed by cross-linking an adhesive composition (hereinafter sometimes referred to as "adhesive composition P") containing a (meth)acrylate polymer (A), a crosslinking agent (B), and a colorant (C). Furthermore, when the adhesive is an active energy ray-curable adhesive, the adhesive composition P preferably further contains an active energy ray-curable component (D).

[0095] The colorant (C) contained in the adhesive composition P is the above-mentioned colorant. The adhesive obtained from the adhesive composition P can exhibit excellent optical properties, adhesion, durability (step difference tracking under high temperature and high humidity conditions), etc. In addition, in this specification, (meth)acrylic acid refers to acrylic acid and methacrylic acid. Other similar terms are the same. In addition, the concept of "polymer" also includes "copolymer".

[0096] (1) Components of the adhesive composition

[0097] (1-1) (Meth)acrylate polymer (A)

[0098] The (meth)acrylate polymer (A) of this embodiment preferably contains a reactive group-containing monomer as a monomer unit constituting the polymer, wherein the reactive group-containing monomer has a reactive group within the molecule that reacts with the crosslinking agent (B). By reacting the reactive group derived from the reactive group-containing monomer with the crosslinking agent (B), a crosslinked structure (three-dimensional network structure) is formed, thereby providing an adhesive having the desired cohesive strength.

[0099] Preferred examples of the reactive group-containing monomer include monomers having a hydroxyl group in the molecule (hydroxyl group-containing monomers), monomers having a carboxyl group in the molecule (carboxyl group-containing monomers), and monomers having an amino group in the molecule (amino group-containing monomers). Among these, hydroxyl group-containing monomers or carboxyl group-containing monomers are preferred, as they have excellent reactivity with the crosslinking agent (B). It is also preferred to use both hydroxyl group-containing monomers and carboxyl group-containing monomers.

[0100] Examples of hydroxyl-containing monomers include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Among these, hydroxyalkyl (meth)acrylates having a hydroxyalkyl group having 1 to 4 carbon atoms are preferred, from the perspective of the reactivity of the hydroxyl group in the resulting (meth)acrylate polymer (A) with the crosslinking agent (B) and copolymerizability with other monomers. Specifically, examples include 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate, and particularly preferably, 2-hydroxyethyl acrylate or 4-hydroxybutyl acrylate. These hydroxyl-containing monomers may be used alone or in combination of two or more.

[0101] Examples of carboxyl group-containing monomers include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. Among these, acrylic acid is preferred from the perspective of the reactivity of the carboxyl groups in the resulting (meth)acrylate polymer (A) with the crosslinking agent (B) and copolymerizability with other monomers. These carboxyl group-containing monomers may be used alone or in combination of two or more.

[0102] Examples of the amino group-containing monomer include aminoethyl (meth)acrylate, n-butylaminoethyl (meth)acrylate, etc. These amino group-containing monomers may be used alone or in combination of two or more.

[0103] (Meth)acrylate polymer (A) preferably contains a reactive group-containing monomer having a lower limit of 1% by mass or more, more preferably 5% by mass or more, and particularly preferably 10% by mass or more as a monomer unit constituting the polymer. In addition, since the dispersibility of the colorant (C) in the adhesive tends to become better, it is further preferred to contain 12% by mass or more, and most preferably 15% by mass or more. On the other hand, (meth)acrylate polymer (A) preferably contains a reactive group-containing monomer having an upper limit of 35% by mass or less, more preferably 30% by mass or less, and particularly preferably 20% by mass or less as a monomer unit constituting the polymer. In addition, since the dispersibility of the colorant (C) in the adhesive tends to become better, it is further preferred to contain 18% by mass or less. If (meth)acrylate polymer (A) contains a reactive group-containing monomer as a monomer unit in the above-mentioned amount, a good cross-linked structure can be formed in the resulting adhesive to obtain the desired cohesive force. In addition, the dispersibility of the colorant (C) in the adhesive has a tendency to become good, and the reproducibility and uniformity of the above-mentioned optical properties of the obtained adhesive become good, and it is easy to satisfy the above-mentioned formula (IV) (and formula (V)), showing excellent design and visibility. Further, when the reactive group-containing monomer is a hydroxyl-containing monomer, the content is particularly preferably more than 15% by mass. At this time, a specified amount of hydroxyl groups remain in the adhesive. Hydroxyl groups are hydrophilic groups. If such hydrophilic groups are present in the adhesive in a specified amount, even when the adhesive is placed under high temperature and high humidity conditions, the compatibility with the water immersed in the adhesive under the high temperature and high humidity conditions is also good, and as a result, the whitening of the adhesive when returning to normal temperature and humidity is suppressed (excellent resistance to wet heat whitening).

[0104] In addition, the (meth)acrylate polymer (A) also preferably does not contain a carboxyl-containing monomer as a monomer unit constituting the polymer. Since the carboxyl group is an acid component, by not containing a carboxyl-containing monomer, even when there is a substance that produces adverse conditions due to acid on the adhesive's attachment object, such as a transparent conductive film or metal film such as tin-doped indium oxide (ITO), the above-mentioned adverse conditions (corrosion, resistance value change, etc.) caused by the acid can be suppressed. However, it is also allowed to contain a specified amount of carboxyl-containing monomer to the extent that the above-mentioned adverse conditions are not produced. Specifically, in the (meth)acrylate polymer (A), it is allowed to contain a carboxyl-containing monomer as a monomer unit in an amount of less than 0.1% by mass, preferably in an amount of less than 0.01% by mass, and further preferably in an amount of less than 0.001% by mass.

[0105] The (meth)acrylate polymer (A) preferably contains an alkyl (meth)acrylate as a monomer unit constituting the polymer. This allows for excellent adhesiveness. The alkyl group may be linear or branched.

[0106] From the perspective of adhesion and dispersibility of the colorant (C), the alkyl (meth)acrylate is preferably one having an alkyl group with 1 to 20 carbon atoms. Examples of the alkyl (meth)acrylate having an alkyl group with 1 to 20 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, and octadecyl (meth)acrylate. Among these, from the perspective of further improving adhesion, a (meth)acrylate having an alkyl group with 1 to 8 carbon atoms is preferred, with methyl (meth)acrylate, n-butyl (meth)acrylate, or 2-ethylhexyl (meth)acrylate being particularly preferred, and methyl methacrylate, n-butyl acrylate, or 2-ethylhexyl acrylate being even more preferred. These alkyl (meth)acrylates may be used alone or in combination of two or more.

[0107] The (meth)acrylate polymer (A) preferably contains 50% by mass or more, particularly preferably 60% by mass or more, and further preferably 65% by mass or more of (meth)acrylate alkyl ester as the monomer unit constituting the polymer. If the lower limit of the content of the (meth)acrylate alkyl ester is as described above, the (meth)acrylate polymer (A) can exert suitable adhesion. In addition, there is a tendency to make the dispersion of the colorant (C) in the adhesive good, and the (meth)acrylate polymer (A) does not impair the required adhesion. Thus, the resulting adhesive can exert suitable adhesion, and the reproducibility and uniformity of the above-mentioned optical properties become good, and it is easy to satisfy the above-mentioned formula (IV) (and formula (V)), showing excellent design and visibility. On the other hand, the (meth)acrylate polymer (A) preferably contains 99% by mass or less, more preferably 95% by mass or less, particularly preferably 90% by mass or less, and further preferably 85% by mass or less of (meth)acrylate alkyl ester as the monomer unit constituting the polymer. When the upper limit of the content of the alkyl (meth)acrylate is as described above, other monomer components such as a reactive functional group-containing monomer can be introduced into the (meth)acrylate polymer (A) in appropriate amounts.

[0108] The (meth)acrylate polymer (A) also preferably contains a monomer having an alicyclic structure within the molecule (alicyclic structure-containing monomer) as a monomer unit constituting the polymer. Since alicyclic structure-containing monomers are bulky, their presence in the polymer presumably increases the spacing between the polymers, resulting in excellent flexibility in the resulting adhesive. This improves the adhesive's ability to follow uneven surfaces.

[0109] The carbon ring of the alicyclic structure in the alicyclic structure-containing monomer may be a saturated structure or may have an unsaturated bond in part. In addition, the alicyclic structure may be a monocyclic alicyclic structure or a polycyclic alicyclic structure such as a bicyclic or tricyclic structure. From the perspective of making the distance between the obtained (meth)acrylate polymers (A) appropriate and imparting higher stress relaxation properties to the adhesive, the above-mentioned alicyclic structure is preferably a polycyclic alicyclic structure (polycyclic structure). Furthermore, considering the compatibility of the (meth)acrylate polymer (A) with other components, the above-mentioned polycyclic structure is particularly preferably a bicyclic to tetracyclic structure. In addition, as described above, from the perspective of imparting stress relaxation properties, the number of carbon atoms in the alicyclic structure (referring to the total number of carbon atoms in the part forming the ring, and when multiple rings exist independently, it refers to the total number of carbon atoms) is generally preferably 5 or more, and particularly preferably 7 or more. On the other hand, although the upper limit of the number of carbon atoms in the alicyclic structure is not particularly limited, it is preferably 15 or less, and particularly preferably 10 or less, from the perspective of compatibility as described above.

[0110] Specific examples of the alicyclic structure-containing monomer include cyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, adamantyl (meth)acrylate, isobornyl (meth)acrylate, biscyclopentenyl (meth)acrylate, and biscyclopentenyloxyethyl (meth)acrylate. Among these, biscyclopentyl (meth)acrylate (alicyclic structure with 10 carbon atoms), adamantyl (meth)acrylate (alicyclic structure with 10 carbon atoms), and isobornyl (meth)acrylate (alicyclic structure with 7 carbon atoms) are preferred, as they exhibit superior step-following properties. Isobornyl (meth)acrylate is particularly preferred, and isobornyl acrylate is even more preferred. These alicyclic structure-containing monomers may be used alone or in combination of two or more.

[0111] When the (meth)acrylate polymer (A) contains an alicyclic structure-containing monomer as a monomer unit constituting the polymer, the content of the alicyclic structure-containing monomer is preferably 1% by mass or more, particularly preferably 4% by mass or more, and even more preferably 8% by mass or more. Furthermore, the (meth)acrylate polymer (A) preferably contains 30% by mass or less, particularly preferably 22% by mass or less, and even more preferably 14% by mass or less of the alicyclic structure-containing monomer as a monomer unit constituting the polymer. By adjusting the content of the alicyclic structure-containing monomer within the above range, the resulting adhesive exhibits even better step-following properties and also exhibits even better adhesion to plastics.

[0112] In addition, the above-mentioned (meth) acrylate polymer (A) also preferably contains a nitrogen-containing monomer as a monomer unit constituting the polymer. By making the nitrogen-containing monomer present in the polymer as a structural unit, the polarity specified in the adhesive can be given, so that the adhesive has excellent affinity even for adherends with a certain degree of polarity such as glass. From the perspective of giving the (meth) acrylate polymer (A) suitable rigidity, as the above-mentioned nitrogen-containing monomer, a monomer with a nitrogen-containing heterocycle is preferred. In addition, from the perspective of increasing the degree of freedom of the part from the above-mentioned nitrogen-containing monomer in the high-dimensional structure of the adhesive formed, it is preferred that the nitrogen-containing monomer does not contain a reactive unsaturated double bond group except for a polymerizable group used in the polymerization for forming the (meth) acrylate polymer (A).

[0113] Examples of monomers having a nitrogen-containing heterocyclic ring include N-(meth)acryloylmorpholine, N-vinyl-2-pyrrolidone, N-(meth)acryloylpyrrolidone, N-(meth)acryloylpiperidine, N-(meth)acryloylpyrrolidine, N-(meth)acryloylaziridine, aziridinylethyl(meth)acrylate, 2-vinylpyridine, 4-vinylpyridine, 2-vinylpyrazine, 1-vinylimidazole, N-vinylcarbazole, and N-vinylphthalimide. Among these, N-(meth)acryloylmorpholine, which exhibits superior adhesion, is preferred, and N-acryloylmorpholine is particularly preferred. These monomers having a nitrogen-containing heterocyclic ring may be used alone or in combination of two or more.

[0114] When the (meth)acrylate polymer (A) contains a nitrogen-containing monomer as a monomer unit constituting the polymer, the content of the nitrogen-containing monomer is preferably 1% by mass or more, particularly preferably 4% by mass or more, and even more preferably 8% by mass or more. Furthermore, the (meth)acrylate polymer (A) preferably contains 20% by mass or less, particularly preferably 16% by mass or less, and even more preferably 12% by mass or less of the nitrogen-containing monomer as a monomer unit constituting the polymer. When the content of the nitrogen-containing monomer is within the above range, the resulting adhesive can fully demonstrate excellent adhesion to glass.

[0115] The (meth)acrylate polymer (A) may contain other monomers as monomer units constituting the polymer as needed. In order not to hinder the above-mentioned effects of the reactive functional group-containing monomer, the other monomers are preferably monomers that do not contain reactive functional groups. Examples of such monomers include alkoxyalkyl (meth)acrylates such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate, vinyl acetate, and styrene. These other monomers may be used alone or in combination of two or more.

[0116] The (meth)acrylate polymer (A) is preferably a linear polymer. This facilitates entanglement of the molecular chains, which can be expected to improve cohesive strength. Consequently, the resulting adhesive tends to have appropriate storage modulus, gel fraction, and adhesive strength, and exhibits excellent step-adjustability under high-temperature and high-humidity conditions.

[0117] Furthermore, the (meth)acrylate polymer (A) is preferably a solution polymer obtained by solution polymerization. Since a solution polymer can easily produce a high molecular weight polymer, it can be expected that the cohesive force will be improved. Therefore, the storage modulus, gel fraction, and adhesive force of the resulting adhesive are likely to be appropriate, and the adhesive has excellent step-following properties under high temperature and high humidity conditions.

[0118] The polymerization form of the (meth)acrylate polymer (A) may be a random copolymer or a block copolymer.

[0119] The lower limit of the weight average molecular weight of (methyl) acrylate polymer (A) is preferably more than 200,000, particularly preferably more than 300,000, further preferably more than 400,000, and from the perspective of the dispersibility of colorant (C), more preferably more than 500,000, particularly preferably more than 700,000. If the lower limit of the weight average molecular weight of (methyl) acrylate polymer (A) is above-mentioned, then the storage modulus, gel fraction and adhesion of the obtained adhesive are easy to become appropriate, and the step tracking property under high temperature and high humidity conditions is more excellent. In addition, there is a tendency that the dispersibility of colorant (C) in adhesive is good, so the reproducibility and uniformity of the above-mentioned optical properties of the obtained adhesive are good, and it is easy to satisfy above-mentioned formula (IV) (and formula (V)), showing excellent design and visibility.

[0120] In addition, the upper limit value of the weight average molecular weight of (meth) acrylate polymer (A) is preferably less than 2,000,000, particularly preferably less than 1,500,000, more preferably less than 1,000,000. If the upper limit value of the weight average molecular weight of (meth) acrylate polymer (A) is above-mentioned, then the storage modulus, gel fraction and adhesion of the obtained adhesive etc. are easily become appropriate, and the initial stage difference followability is more excellent. In addition, the weight average molecular weight in this specification is the value converted by standard polystyrene measured by gel permeation chromatography (GPC) method.

[0121] In the adhesive composition P, the (meth)acrylate polymer (A) may be used alone or in combination of two or more.

[0122] (1-2) Cross-linking agent (B)

[0123] The crosslinking agent (B) can crosslink the (meth)acrylate polymer (A) to form a favorable three-dimensional network structure by heating the adhesive composition P. This improves the cohesive force of the resulting adhesive and improves the step-adjustability under high-temperature and high-humidity conditions.

[0124] As the crosslinking agent (B), any crosslinking agent that reacts with the reactive group possessed by the (meth)acrylate polymer (A) may be used, for example, isocyanate crosslinking agents, epoxy crosslinking agents, amine crosslinking agents, melamine crosslinking agents, aziridine crosslinking agents, hydrazine crosslinking agents, aldehyde crosslinking agents, oxazoline crosslinking agents, metal alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents, ammonium salt crosslinking agents, etc. Among the above, when the reactive group possessed by the (meth)acrylate polymer (A) is a hydroxyl group, it is preferred to use an isocyanate crosslinking agent that has excellent reactivity with the hydroxyl group, and when the reactive group possessed by the (meth)acrylate polymer (A) is a carboxyl group, it is preferred to use an epoxy crosslinking agent that has excellent reactivity with the carboxyl group. In addition, the crosslinking agent (B) may be used alone or in combination of two or more.

[0125] Isocyanate crosslinking agents contain at least a polyisocyanate compound. Examples of polyisocyanate compounds include aromatic polyisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate; and biuret forms and isocyanurate forms thereof, as well as adducts thereof reacted with low molecular weight active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Among these, trimethylolpropane-modified aromatic polyisocyanates are preferred from the perspective of reactivity with hydroxyl groups, with trimethylolpropane-modified toluene diisocyanate and trimethylolpropane-modified xylylene diisocyanate being particularly preferred.

[0126] Examples of epoxy crosslinking agents include 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-xylenediamine, ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidylaniline, and diglycidylamine. Among these, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane is preferred from the perspective of reactivity with carboxyl groups.

[0127] Relative to 100 parts by mass of (meth)acrylate polymer (A), the content of the crosslinking agent (B) in the adhesive composition P is preferably more than 0.01 parts by mass, particularly preferably more than 0.05 parts by mass, and more preferably more than 0.1 parts by mass. In addition, the content is preferably less than 10 parts by mass, more preferably less than 5 parts by mass, particularly preferably less than 1 part by mass, and more preferably less than 0.4 parts by mass. By making the content of the crosslinking agent (B) within the above range, the resulting adhesive exerts good cohesive force, easily satisfies the required storage modulus, gel fraction and adhesion, and the step followability under high temperature and high humidity conditions is more excellent.

[0128] (1-3) Colorant (C)

[0129] The colorant (C) is the colorant described above, and the specific type is the same as described above.

[0130] The content of the colorant (C) relative to 100 parts by mass of the (meth)acrylate polymer (A) is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, particularly preferably 0.3 parts by mass or more, and even more preferably 0.6 parts by mass or more. Furthermore, the content is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, particularly preferably 2 parts by mass or less, even more preferably 1 part by mass or less, and most preferably 0.9 parts by mass or less. By setting the content of the colorant (C) within the above range, the resulting adhesive easily satisfies the above-mentioned optical properties and easily satisfies the above-mentioned formula (IV) (and formula (V)), exhibiting excellent design and visibility.

[0131] (1-4) Active energy ray-curable component (D)

[0132] In an adhesive formed by crosslinking the adhesive composition P and then curing it with active energy rays, it is speculated that the active energy ray-curable component (D) polymerizes with each other, and the polymerized active energy ray-curable component (D) is entangled in the crosslinked structure (three-dimensional network structure) of the (meth)acrylate polymer (A). This adhesive with a high-dimensional structure exhibits extremely excellent durability and is particularly good at following unevenness under high temperature and high humidity conditions.

[0133] The active energy ray-curable component (D) is not particularly limited as long as it is a component that is cured by irradiation with active energy rays and can achieve the above-mentioned effects. It can be any of a monomer, an oligomer, or a polymer, or a mixture thereof. Among them, polyfunctional acrylate monomers, which have excellent anti-foaming properties, are preferably used.

[0134] Examples of the multifunctional acrylate monomer include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, neopentyl glycol hydroxypivalate di(meth)acrylate, dicyclopentyl di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphoric acid di(meth)acrylate, di(acryloyloxyethyl) isocyanurate, allyl cyclohexyl di(meth)acrylate, ethoxylated bisphenol A diacrylate, 9,9-bis[4-(2-acryloyloxy)]-bis(acryloyloxy)-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1,2-diol-1 The present invention also provides a plurality of multifunctional acrylic monomers, including difunctional acrylic monomers such as trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(acryloyloxyethyl)isocyanurate, and ε-caprolactone-modified tris(2-(meth)acryloyloxyethyl)isocyanurate; tetrafunctional acrylic monomers such as diglycerol tetra(meth)acrylate and pentaerythritol tetra(meth)acrylate; pentafunctional acrylic monomers such as propionic acid-modified dipentaerythritol penta(meth)acrylate; and hexafunctional acrylic monomers such as dipentaerythritol hexa(meth)acrylate and caprolactone-modified dipentaerythritol hexa(meth)acrylate. These multifunctional acrylic monomers may be used alone or in combination of two or more. Furthermore, from the viewpoint of compatibility with the (meth)acrylate polymer (A), the molecular weight of the polyfunctional acrylate monomer is preferably less than 1,000.

[0135] Among the above, from the viewpoint of the anti-foaming property of the obtained adhesive, polyfunctional acrylate monomers containing an isocyanurate structure in the molecule, such as di(acryloyloxyethyl)isocyanurate, tri(acryloyloxyethyl)isocyanurate, and ε-caprolactone-modified tri(2-(meth)acryloyloxyethyl)isocyanurate, or polyfunctional acrylate monomers containing a cyclic structure (particularly a cycloalkane structure) in the molecule, such as tricyclodecane dimethanol (meth)acrylate, are preferred. Polyfunctional acrylate monomers having a functionality of more than three and containing an isocyanurate structure in the molecule are more preferred. A multifunctional acrylate monomer having a urate structure, or a multifunctional acrylate monomer having a functionality higher than two and containing a polycyclic structure (especially a polycyclic structure of a cycloalkane) in the molecule, particularly preferably ε-caprolactone-modified tris(2-(meth)acryloyloxyethyl)isocyanurate or tricyclodecane dimethanol (meth)acrylate, further preferably ε-caprolactone-modified tris(2-acryloyloxyethyl)isocyanurate or tricyclodecane dimethanol acrylate, most preferably ε-caprolactone-modified tris(2-acryloyloxyethyl)isocyanurate.

[0136] From the perspective of achieving superior step-following properties of the adhesive after active energy ray curing under high temperature and high humidity conditions, the lower limit of the content of the active energy ray-curable component (D) in the adhesive composition P is preferably 1 part by mass or more, particularly preferably 3 parts by mass or more, and even more preferably 4 parts by mass or more, relative to 100 parts by mass of the (meth)acrylate polymer (A). On the other hand, from the perspective of the adhesive strength of the adhesive after active energy ray curing, the upper limit of the above content is preferably 20 parts by mass or less, particularly preferably 12 parts by mass or less, and even more preferably 8 parts by mass or less.

[0137] (1-5) Photopolymerization initiator (E)

[0138] When ultraviolet rays are used as the active energy rays for curing the adhesive composition P, it is preferred that the adhesive composition P further contain a photopolymerization initiator (E). By containing the photopolymerization initiator (E), the active energy ray-curable component (D) can be efficiently polymerized, and the polymerization curing time and the irradiation dose of the active energy rays can be reduced.

[0139] Examples of such a photopolymerization initiator (E) include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-1-propanone, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone, p-phenylenediol, Ketone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoate, oligo[2-hydroxy-2-methyl-1[4-(1-methylvinyl)phenyl]propanone], 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, etc. These photopolymerization initiators may be used alone or in combination of two or more.

[0140] Among the above, phosphine oxide-based photopolymerization initiators are preferred because they readily decompose even when irradiated with ultraviolet light through a plastic plate containing an ultraviolet absorber, allowing the adhesive to reliably cure. Specifically, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide are preferred.

[0141] The lower limit of the content of the photopolymerization initiator (E) in the adhesive composition P is preferably 0.1 parts by mass or more, particularly preferably 1 part by mass or more, and further preferably 5 parts by mass or more, relative to 100 parts by mass of the active energy ray-curable component (D). The upper limit is preferably 30 parts by mass or less, particularly preferably 20 parts by mass or less, and further preferably 12 parts by mass or less.

[0142] The mass ratio of the amount of the photopolymerization initiator (E) to the amount of the colorant (C) (photopolymerization initiator (E) / colorant (C)) is preferably 0.01 or more, particularly preferably 0.1 or more, and even more preferably 0.2 or more. Furthermore, this mass ratio is preferably 5 or less, particularly preferably 3 or less, and even more preferably 1 or less. By setting the ratio of the amount of the photopolymerization initiator (E) to the amount of the colorant (C) within the above range, the above-mentioned optical properties are easily satisfied, and an adhesive having suitable cohesive force or tackiness can be easily obtained by curing with active energy rays, and the step-following properties under high temperature and high humidity conditions are further improved.

[0143] (1-6) Various additives

[0144] Various additives commonly used in acrylic adhesives, such as silane coupling agents, rust inhibitors, UV absorbers, antistatic agents, tackifiers, antioxidants, light stabilizers, softeners, and refractive index modifiers, may be added to the adhesive composition P as needed. The polymerization solvent or dilution solvent described below is not included in the additives constituting the adhesive composition P.

[0145] Among the above, the adhesive composition P preferably contains a silane coupling agent. This improves adhesion to the adherend, regardless of whether the adherend is a plastic plate or a glass member, and further improves step conformability under high-temperature and high-humidity conditions.

[0146] As the silane coupling agent, an organosilicon compound having good compatibility with the (meth)acrylate polymer (A), light-transmitting properties, and having at least one alkoxysilyl group in the molecule is preferred.

[0147] Examples of the silane coupling agent include silicon compounds containing polymerizable unsaturated groups such as vinyltrimethoxysilane, vinyltriethoxysilane, and methacryloxypropyltrimethoxysilane; silicon compounds having epoxy structures such as 3-glycidoxypropyltrimethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; and silicon compounds containing mercapto groups such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropyldimethoxymethylsilane. Silicon compounds containing amino groups such as 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane; condensates of 3-chloropropyltrimethoxysilane, isocyanatepropyltriethoxysilane, or at least one of these with methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, and ethyltrimethoxysilane, etc. These silane coupling agents may be used alone or in combination of two or more.

[0148] The content of the silane coupling agent in the adhesive composition P is preferably 0.01 parts by mass or more, particularly preferably 0.05 parts by mass or more, and more preferably 0.1 parts by mass or more relative to 100 parts by mass of the (meth)acrylate polymer (A). In addition, the content is preferably 1 part by mass or less, particularly preferably 0.5 parts by mass or less, and more preferably 0.3 parts by mass or less. By making the content of the silane coupling agent within the above range, the resulting adhesive satisfies the above-mentioned optical properties, easily exhibits suitable cohesive force or adhesion, and has excellent step tracking properties under high temperature and high humidity conditions.

[0149] (2) Preparation of adhesive composition

[0150] The adhesive composition P can be prepared by preparing a (meth)acrylate polymer (A), mixing the obtained (meth)acrylate polymer (A), a crosslinking agent (B), and a colorant (C), and adding an active energy ray-curable component (D), a photopolymerization initiator (E), additives, etc. as needed.

[0151] The (meth)acrylate polymer (A) can be prepared by polymerizing a mixture of monomers constituting the polymer using a conventional free radical polymerization method. The polymerization of the (meth)acrylate polymer (A) is preferably carried out by solution polymerization using a polymerization initiator as needed. However, the present invention is not limited thereto, and polymerization can also be carried out in the absence of a solvent. Examples of polymerization solvents include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, and methyl ethyl ketone, and two or more thereof may be used simultaneously.

[0152] Examples of the polymerization initiator include azo compounds and organic peroxides, and two or more thereof may be used simultaneously. Examples of the azo compound include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), 2,2'-azobis(2-

[0153] dimethyl propionate, 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-hydroxymethylpropionitrile), 2,2'-azobis[2-(2-imidazolin-2-yl)propane], etc.

[0154] Examples of the organic peroxide include benzoyl peroxide, tert-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di(2-ethoxyethyl) peroxydicarbonate, tert-butyl peroxyneodecanoate, tert-butyl peroxypivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide, and diacetyl peroxide.

[0155] Furthermore, in the polymerization step, the weight average molecular weight of the obtained polymer can be adjusted by adding a chain transfer agent such as 2-mercaptoethanol.

[0156] After obtaining the (meth)acrylate polymer (A), a crosslinking agent (B), a colorant (C), and, if desired, a diluting solvent, an active energy ray-curable component (D), a photopolymerization initiator (E), additives, and the like are added to the (meth)acrylate polymer (A) solution and thoroughly mixed to obtain a solvent-diluted adhesive composition P (coating solution). If any of the above components is used in solid form, or if a precipitate forms when mixed with other components in an undiluted state, the component may be dissolved or diluted in a diluting solvent before mixing with the other components.

[0157] As the above-mentioned dilution solvent, for example, aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as dichloromethane and vinyl chloride; alcohols such as methanol, ethanol, propanol, butanol, and 1-methoxy-2-propanol; ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, and cyclohexanone; esters such as ethyl acetate and butyl acetate; cellosolve-type solvents such as ethyl cellosolve, etc. can be used.

[0158] The concentration and viscosity of the coating solution prepared in this manner are not particularly limited as long as they are within the range that can be applied, and can be appropriately selected according to the circumstances. For example, the adhesive composition P is diluted so that the concentration becomes 10 to 60% by mass. In addition, when obtaining the coating solution, it is not necessary to add a diluting solvent, etc. As long as the adhesive composition P is of a viscosity that can be applied, a diluting solvent may not be added. In this case, the adhesive composition P is a coating solution in which the polymerization solvent of the (meth)acrylate polymer (A) is directly used as the diluting solvent.

[0159] (3) Formation of colored adhesive layer

[0160] The colored adhesive layer 11 of this embodiment is preferably composed of an adhesive formed by crosslinking (the coating layer of) the adhesive composition P. Crosslinking of the adhesive composition P can generally be performed by heat treatment. Alternatively, the drying process, which volatilizes the diluting solvent or the like from the coating layer of the adhesive composition P applied to the desired object, can also serve as the heat treatment.

[0161] The heating temperature of the heat treatment is preferably 50 to 150° C., particularly preferably 70 to 120° C. The heating time is preferably 10 seconds to 10 minutes, particularly preferably 50 seconds to 2 minutes.

[0162] After the heat treatment, an aging period of about 1 to 2 weeks at room temperature (e.g., 23°C, 50% RH) may be provided as needed. If this aging period is required, the adhesive is formed after the aging period. If this aging period is not required, the adhesive is formed directly after the heat treatment is completed.

[0163] The heat treatment (and aging) allows the (meth)acrylate polymer (A) to be fully crosslinked via the crosslinking agent (B). The resulting adhesive readily satisfies the desired storage modulus, gel fraction, and adhesive strength, and exhibits excellent step-adjustability under high-temperature and high-humidity conditions.

[0164] (4) Physical properties of adhesive

[0165] The adhesive of this embodiment preferably has the following physical properties.

[0166] (4-1) Gel fraction

[0167] The lower limit of the gel fraction of the present embodiment is preferably 20% or more, more preferably 40% or more, particularly preferably 50% or more, and further preferably 60% or more. If the lower limit of the gel fraction of the adhesive is as described above, the cohesive force of the adhesive becomes higher, and the step followability under high temperature and high humidity conditions is more excellent. In addition, the upper limit of the gel fraction of the adhesive of the present embodiment is preferably 100% or less, more preferably 90% or less, particularly preferably 80% or less, further preferably 70% or less, and most preferably 69% or less. If the upper limit of the gel fraction of the adhesive is as described above, the adhesive will not become too hard, and the initial step followability and the step followability under high temperature and high humidity conditions are both excellent. In addition, good adhesion is exhibited, and the adhesion to the adherend is more excellent.

[0168] The method for measuring the gel fraction of the adhesive is described in the test examples below. Furthermore, when the adhesive is an active energy ray-curable adhesive, the gel fraction of the adhesive after active energy ray curing is used. Furthermore, from the perspective of ensuring good initial step-adjustability, when the adhesive is an active energy ray-curable adhesive, the gel fraction of the adhesive before active energy ray curing is preferably 20-70%, particularly preferably 30-60%, and even more preferably 40-55%.

[0169] (4-2) Storage modulus

[0170] The lower limit of the storage modulus of the adhesive of this embodiment at 23°C is preferably 0.001MPa or more, more preferably 0.01MPa or more, particularly preferably 0.05MPa or more, and further preferably 0.1MPa or more. By setting the lower limit of the storage modulus to the above, the step followability under high temperature and high humidity conditions is excellent. In addition, the upper limit of the storage modulus is preferably 2MPa or less, more preferably 1MPa or less, particularly preferably 0.8MPa or less, further preferably 0.4MPa or less, and most preferably 0.2MPa or less. By setting the upper limit of the storage modulus to the above, the initial step followability and the step followability under high temperature and high humidity conditions are excellent.

[0171] Here, the storage modulus in this specification is a value measured using a torsional shear method (Nejirisen method) at a measurement frequency of 1 Hz in accordance with JIS K7244-6. Specifically, as shown in the test examples described later. In addition, when the adhesive is an active energy ray-curable adhesive, it is set to the storage modulus of the adhesive after active energy ray curing. In addition, from the perspective of being able to make the initial step followability good, when the adhesive is an active energy ray-curable adhesive, the storage modulus of the adhesive before active energy ray curing is preferably 0.01 to 1 MPa, particularly preferably 0.02 to 0.5 MPa, and more preferably 0.04 to 0.1 MPa.

[0172] (5) Thickness of the colored adhesive layer

[0173] The lower limit of the thickness of the colored adhesive layer 11 is preferably 1 μm or more, more preferably 2 μm or more, and particularly preferably 4 μm or more. When the lower limit of the thickness of the colored adhesive layer 11 is as described above, the above-mentioned formula (IV) (and formula (V)) is easily satisfied due to the relationship with the content of the colorant (C), and the desired adhesive force is easily exerted. Furthermore, from the perspective of easily exerting excellent step-adjustability, the lower limit of the thickness of the colored adhesive layer 11 is preferably 10 μm or more, more preferably 20 μm or more, particularly preferably 50 μm or more, and even more preferably 80 μm or more.

[0174] On the other hand, the upper limit of the thickness of the colored adhesive layer 11 is preferably 500 μm or less, more preferably 300 μm or less, particularly preferably 200 μm or less, and further preferably 150 μm or less. If the upper limit of the thickness of the colored adhesive layer 11 is as described above, the processability is good, and in addition, it is not easy to produce a poor appearance caused by extrusion marks. Furthermore, due to the relationship with the content of the colorant (C), it is easy to satisfy the above-mentioned formula (IV) (and formula (V)). And, from the perspective of being more likely to satisfy the above-mentioned formula (IV) (and formula (V)), the thickness of the colored adhesive layer 11 is more preferably 120 μm or less, particularly preferably 75 μm or less, and further preferably 30 μm or less. In addition, the colored adhesive layer 11 can be formed by a single layer or by stacking multiple layers.

[0175] 1-2. Peel sheet

[0176] The release sheets 12a and 12b protect the colored adhesive layer 11 until the colored adhesive sheet 1 is used, and are peeled off when the colored adhesive sheet 1 (colored adhesive layer 11) is used. In the colored adhesive sheet 1 of this embodiment, one or both of the release sheets 12a and 12b are not essential.

[0177] As the release sheets 12a and 12b, for example, polyethylene film, polypropylene film, polybutylene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate film, ionomer resin film, ethylene-(meth)acrylic acid copolymer film, ethylene-(meth)acrylate copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, etc. can be used. In addition, cross-linked films of these films can also be used. Furthermore, laminated films of these films can also be used.

[0178] The release surfaces of the release sheets 12a and 12b (particularly the surface in contact with the colored adhesive layer 11) are preferably subjected to a release treatment. Examples of release agents used for the release treatment include alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, and wax-based release agents. Furthermore, it is preferred that one of the release sheets 12a and 12b be a heavy-release type with a greater release force, and the other be a light-release type with a lesser release force.

[0179] The thickness of the release sheets 12a and 12b is not particularly limited, but is generally about 20 to 150 μm.

[0180] 2. Physical properties (adhesion)

[0181] The lower limit of the adhesion of the colored adhesive sheet 1 of the present embodiment to the soda-lime glass is preferably 1N / 25mm or more, more preferably 2N / 25mm or more, particularly preferably 4N / 25mm or more, and further preferably 8N / 25mm or more. If the lower limit of the adhesion is as described above, the step tracking property under high temperature and high humidity conditions is more excellent. In addition, the upper limit of the adhesion of the colored adhesive sheet 1 of the present embodiment to the soda-lime glass is preferably 80N / 25mm or less, more preferably 50N / 25mm or less, and particularly preferably 30N / 25mm or less. If the upper limit of the adhesion is as described above, good reoperability can be obtained, and when a bonding error occurs, the display component, especially the expensive display component, can be reused.

[0182] Here, the adhesive strength in this specification refers to the adhesive strength measured by the 180-degree peeling method basically in accordance with JIS Z0237:2009. It is a measurement sample made into 25 mm wide and 100 mm long, attached to the adherend, pressurized at 0.5 MPa and 50°C for 20 minutes, left under normal pressure, 23°C, and 50% RH for 24 hours, and then measured at a peeling speed of 300 mm / min. In addition, when the adhesive is an active energy ray-curable adhesive, it is the adhesive strength of the colored adhesive layer that is cured by active energy rays after being attached to the adherend. In addition, from the perspective of close adhesion to the adherend and reworkability, when the adhesive is an active energy ray-curable adhesive, the adhesive strength of the adhesive before active energy ray curing is preferably 1 to 80 N / 25 mm, particularly preferably 2 to 50 N / 25 mm, and even more preferably 4 to 30 N / 25 mm.

[0183] 3. Production of colored adhesive sheets

[0184] As a manufacturing example of a colored adhesive sheet 1, a coating solution of the adhesive composition P is applied to the release surface of a release sheet 12a (or 12b), and a heat treatment is performed to thermally crosslink the adhesive composition P. After forming a coating layer, the coating layer is superimposed on the release surface of another release sheet 12b (or 12a). When a maturation period is required, the coating layer becomes a colored adhesive layer 11 by setting a maturation period. When a maturation period is not required, the coating layer directly becomes the adhesive layer 11. In this way, the colored adhesive sheet 1 can be obtained. The conditions for the heat treatment and maturation are as described above.

[0185] As another manufacturing example of the colored adhesive sheet 1, a coating solution of the adhesive composition P is applied to the release surface of a release sheet 12a, and a heat treatment is performed to thermally crosslink the adhesive composition P to form a coating layer, thereby obtaining a release sheet 12a with a coating layer. In addition, a coating solution of the adhesive composition P is applied to the release surface of another release sheet 12b, and a heat treatment is performed to thermally crosslink the adhesive composition P to form a coating layer, thereby obtaining a release sheet 12b with a coating layer. Then, the release sheet 12a with a coating layer and the release sheet 12b with a coating layer are laminated in such a manner that the two coating layers are in contact with each other. Here, multiple release sheets with coating layers can be prepared, and the required number of coating layers can be laminated. When a aging period is required, the laminated coating layer becomes the colored adhesive layer 11 by setting the aging period. When a aging period is not required, the laminated coating layer directly becomes the colored adhesive layer 11. Thus, the colored adhesive sheet 1 can be obtained. According to this production example, even when the colored adhesive layer 11 is thick, stable production can be performed.

[0186] As a method for applying the coating solution of the adhesive composition P, for example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method, etc. can be used.

[0187] [Display]

[0188] A display according to one embodiment of the present invention comprises a first display component having at least two regions of differing lightness in a planar direction, a second display component, and a colored adhesive layer bonding the first and second display components to each other. Furthermore, in the display according to this embodiment, assuming that the lightness L* of one region R1 of the first display component, as defined by the CIE 1976 L*a*b* colorimetric system, is L1, the lightness L* of another region R2 is L2, the lightness L* of region R1 on which the colored adhesive layer is laminated is L1', and the lightness L* of region R2 on which the colored adhesive layer is laminated is L2', the following equations (I) to (IV) are satisfied.

[0189] ΔL=L1-L2···(I)

[0190] ΔL'=L1'-L2' (II)

[0191] ΔL>0···(III)

[0192] (ΔL' / ΔL)×100≤80···(IV)

[0193] Examples of the display (display) in this embodiment include in-vehicle displays such as those provided on the dashboard of a car, a car navigation system, or various meters in a console, displays such as tablet terminals used by general users, displays such as tablet terminals or digital signage for commercial use, and displays such as outdoor digital signage. These displays are sometimes required to have an appearance that is coordinated with surrounding components or a sense of luxury. However, the display of the present invention is not limited thereto.

[0194] Figure 2 Detailed configuration of an example of a display according to this embodiment is shown in FIG.

[0195] like Figure 2 As shown, the display 2 of this embodiment is composed of a first display component 21 (one display component), a second display component 22 (another display component) and a colored adhesive layer 11, wherein the colored adhesive layer 11 is located between the first display component 21 and the second display component 22, and adheres the first display component 21 and the second display component 22 to each other.

[0196] At least one of the first display body constituent member 21 and the second display body constituent member 22 may have a step difference on at least the surface on the side to be bonded to the colored adhesive layer 11 . Figure 2 In the embodiment shown, the first display component 21 has a step such as the printed layer 3 on the surface facing the colored adhesive layer 11. In this case, the first display component 21 has at least two regions of different brightness in the planar direction, the region separated by the printed layer 3 and the other regions.

[0197] The colored adhesive layer 11 in the display 2 is preferably the colored adhesive layer 11 of the colored adhesive sheet 1 , but is not limited thereto as long as the above-mentioned physical properties are satisfied.

[0198] Examples of the display 2 include a liquid crystal (LCD) display, a light emitting diode (LED) display, an organic electroluminescent (organic EL) display, and electronic paper, and may also be a touch panel.

[0199] The first display component 21 is preferably a protective panel composed of a laminate containing glass plates, plastic plates, etc. In this case, the printed layer 3 is usually formed in a frame shape on the colored adhesive layer 11 side of the first display component 21.

[0200] The glass plate is not particularly limited, and examples thereof include chemically strengthened glass, alkali-free glass, quartz glass, soda-lime glass, barium-strontium-containing glass, aluminosilicate glass, lead glass, borosilicate glass, and barium borosilicate glass. The thickness of the glass plate is not particularly limited, but is generally 0.1 to 5 mm, preferably 0.2 to 2 mm.

[0201] The plastic plate is not particularly limited, and examples thereof include acrylic plates, polycarbonate plates, etc. The thickness of the plastic plate is not particularly limited, but is generally 0.2 to 5 mm, preferably 0.4 to 3 mm.

[0202] Furthermore, various functional layers (transparent conductive film, metal layer, silicon dioxide layer, hard coating layer, anti-glare layer, etc.) may be provided on one or both sides of the glass or plastic plate, and optical components may be laminated. Furthermore, the transparent conductive film and metal layer may be patterned.

[0203] The second display component 22 is preferably an optical component to be attached to the first display component 21, a display module (for example, a liquid crystal (LCD) module, a light-emitting diode (LED) module, an organic electroluminescent (organic EL) module, etc.), an optical component that is part of a display module, or a stack containing a display module.

[0204] Examples of the optical member include anti-scattering films, polarizing plates (polarizing films), polarizers, phase difference plates (phase difference films), viewing angle compensation films, brightness enhancement films, contrast enhancement films, liquid crystal polymer films, diffusion films, semi-transmissive reflective films, and transparent conductive films. Examples of the anti-scattering film include hard coating films formed on one side of a substrate film.

[0205] The material constituting the printed layer 3 is not particularly limited, and any known material for printing can be used.

[0206] The lower limit of the thickness of the printed layer 3, i.e., the height of the step, is preferably 3 μm or greater, more preferably 5 μm or greater, particularly preferably 7 μm or greater, and most preferably 10 μm or greater. By setting the lower limit above this limit, sufficient concealment of the electrical wiring, etc., from the viewer's side, can be ensured. Furthermore, the upper limit is preferably 50 μm or less, more preferably 35 μm or less, particularly preferably 25 μm or less, and even more preferably 20 μm or less. Setting the upper limit below this limit prevents the colored adhesive layer 11 from poorly following the step of the printed layer 3.

[0207] The printed layer 3 is preferably black. The preferred ranges of lightness L*, chromaticity a*, and chromaticity b* of the printed layer 3, as defined by the CIE 1976 L*a*b* color system, are the same as those of the color tones of the surrounding components. However, the color tones are generally different from those of automobile instrument panels, display frame materials, and the like.

[0208] To produce the display 2 , for example, one release sheet 12 a of the colored adhesive sheet 1 is peeled off, and the exposed colored adhesive layer 11 of the colored adhesive sheet 1 is bonded to the surface of the first display component 21 on the side where the printed layer 3 is located.

[0209] Then, another release sheet 12b is peeled off from the colored adhesive layer 11 of the colored adhesive sheet 1, and the exposed colored adhesive layer 11 of the colored adhesive sheet 1 is laminated to the second display component 22. As another example, the order of laminating the first display component 21 and the second display component 22 may be reversed.

[0210] When the colored adhesive layer 11 is active energy ray-curable, after the first display component 21 and the second display component 22 are bonded together via the colored adhesive layer 11 as described above, the colored adhesive layer 11 is irradiated with active energy rays. This polymerizes the energy ray-curable component (C) in the colored adhesive layer 11, curing the colored adhesive layer 11. Irradiation of the colored adhesive layer 11 with energy rays is typically performed through either the first display component 21 or the second display component 22, preferably through the first display component 21 serving as a protective panel.

[0211] Active energy rays are active energy rays having energy quanta in electromagnetic waves or charged particle beams, and specific examples thereof include ultraviolet rays and electron beams. Among active energy rays, ultraviolet rays are particularly preferred because they are easy to handle.

[0212] The ultraviolet irradiation can be performed using a high-pressure mercury lamp, a fusion H lamp, a xenon lamp, etc. The ultraviolet irradiation dose is preferably 50 to 1000 mW / cm 2 About 100 to 500 mW / cm 2 In addition, the light intensity is preferably 50 to 10000 mJ / cm 2 , more preferably 200 to 7000 mJ / cm 2 , particularly preferably 500 to 3000 mJ / cm 2 On the other hand, electron beam irradiation can be performed using an electron beam accelerator or the like, and the irradiation dose of the electron beam is preferably about 10 to 1000 krad.

[0213] Here, if Figure 3As shown, the display 2 (first display component 21) of this embodiment preferably includes a frame material 4 surrounding the display 2 (first display component 21). In this case, the first display component 21 has at least two regions with different brightness in the planar direction, with the region of the first display component 21 and the region outside the frame material 4 being a display component. Furthermore, with respect to the region outside the frame material 4 (the region inside the frame material 4), the region of the printed layer 3 and the region outside the frame material 4 can each have at least two regions with different brightness in the planar direction.

[0214] The frame material 4 is preferably black. Furthermore, the preferred ranges for the lightness L*, chromaticity a*, and chromaticity b* of the frame material 4, as defined by the CIE 1976 L*a*b* color scale, are the same as those for the surrounding components. By providing the frame material 4 with this hue, it is easily recognized by the naked eye as a visually high-quality frame material. Furthermore, by providing the frame material 4 with this hue, the integrated feel of the colored adhesive layer 11 of this embodiment and the frame material 4 is enhanced, resulting in a more harmonious appearance.

[0215] The physical properties of the colored adhesive layer 11 enhance the design of the display 2 when it is off. For example, when the display 2 is off, the boundary with the black frame material 4 is indistinguishable (seamless), achieving excellent visual harmony. Furthermore, if a black printed layer is present inside the frame material 4 of the display 2, the boundary between the display portion of the display 2 and the printed layer, as well as the boundary between the printed layer and the frame material 4, is also difficult to discern when the display 2 is off.

[0216] Furthermore, in the above-mentioned display 2, when the colored adhesive layer 11 is formed from the adhesive composition P, the colored adhesive layer 11 has excellent step-adjustability under high temperature and high humidity conditions. Therefore, for example, even when the display 2 is placed under high temperature and high humidity conditions (for example, 85°C, 85% RH), it is possible to suppress the occurrence of floating, peeling, etc. near the step.

[0217] The step-following rate (%) can be used as an indicator to determine the step-following property. The lower limit of the step-following rate (%) of the colored adhesive layer 11, as expressed by the following formula, is preferably 10% or greater, more preferably 20% or greater, particularly preferably 40% or greater, further preferably 50% or greater, and most preferably 60% or greater. The upper limit of the step-following rate is not particularly limited, but is generally preferably 80% or less, particularly preferably 70% or less.

[0218] Step following rate (%) = [(step height (μm) at which the embedded state is maintained without bubbles, floating, peeling, etc. after the specified durability test) / (thickness of the colored adhesive layer)] × 100

[0219] The test method of the step follow-up rate is shown in the test examples described later.

[0220] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit the present invention. Therefore, the various elements disclosed in the embodiments described above also encompass all design changes or equivalents within the technical scope of the present invention.

[0221] For example, either or both of the release sheets 12a and 12b in the colored adhesive sheet 1 may be omitted. Alternatively, desired optical components may be laminated in place of the release sheets 12a and / or 12b. Furthermore, the first display component 21 may not have a step. Furthermore, not only the first display component 21 but also the second display component 22 may have a step on the colored adhesive layer 11 side.

[0222] Example

[0223] Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the scope of the present invention is not limited to these Examples and the like.

[0224] [Example 1]

[0225] 1. Preparation of (meth)acrylate polymers

[0226] 70 parts by mass of 2-ethylhexyl acrylate, 15 parts by mass of methyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate were copolymerized by solution polymerization to prepare a (meth)acrylate polymer (A). The molecular weight of the (meth)acrylate polymer (A) was measured by the method described below, and the weight average molecular weight (Mw) was 800,000.

[0227] 2. Preparation of adhesive composition

[0228] 100 parts by mass (solid content conversion value; the same applies hereinafter) of the (meth)acrylate polymer (A) obtained in the above step 1, 0.2 parts by mass of trimethylolpropane-modified toluene diisocyanate (manufactured by TOYOCHEM CO., LTD., product name "BHS8515") as a crosslinking agent (B), 0.4 parts by mass of a carbon black-based black pigment (C1) as a colorant (C), and 0.2 parts by mass of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent were mixed and thoroughly stirred, and diluted with methyl ethyl ketone to obtain a coating solution of an adhesive composition.

[0229] Table 1 shows the respective proportions (solid content conversion values) of the adhesive composition when the (meth)acrylate polymer (A) is 100 parts by mass (solid content conversion value). The details of the abbreviations described in Table 1 are as follows.

[0230] [(Meth)acrylate polymer (A)]

[0231] 2EHA: 2-ethylhexyl acrylate

[0232] MMA: Methyl Methacrylate

[0233] HEA: 2-Hydroxyethyl Acrylate

[0234] IBXA: Isobornyl acrylate

[0235] ACMO: N-acryloylmorpholine

[0236] BA: n-butyl acrylate

[0237] AA: Acrylic acid

[0238] [Colorant (C)]

[0239] C1 to C5: Carbon black pigments having the properties shown in Table 2

[0240] 3. Production of colored adhesive sheets

[0241] The coating solution of the adhesive composition obtained in step 2 was applied using a knife coater to the release-treated surface of a heavy-release release sheet (manufactured by Lintec Corporation, product name "SP-PET752150"), one side of which was release-treated with a silicone release agent. The sheet was then heat-treated at 90°C for 1 minute to form a coating layer (thickness: 50 μm). Separately, the coating solution of the adhesive composition obtained in step 2 was applied using a knife coater to the release-treated surface of a light-release release sheet (manufactured by Lintec Corporation, product name "SP-PET381130"), one side of which was release-treated with a silicone release agent. The sheet was then heat-treated at 90°C for 1 minute to form a coating layer (thickness: 50 μm).

[0242] Next, the heavy-peelable release sheet with a coating layer obtained above and the light-peelable release sheet with a coating layer obtained above were attached so that the two coating layers were in contact with each other, and were aged for 7 days under the conditions of 23°C and 50% RH to produce a colored adhesive sheet consisting of a heavy-peelable release sheet / colored adhesive layer (thickness: 100 μm) / light-peelable release sheet.

[0243] The thickness of the colored adhesive layer is a value measured using a constant pressure thickness gauge (manufactured by TECLOCK CO., LTD., product name “PG-02”) in accordance with JIS K7130.

[0244] [Examples 2 to 8, Comparative Example 1]

[0245] A colored adhesive sheet was produced in the same manner as in Example 1, except that the types and ratios of the monomers constituting the (meth)acrylate polymer (A), the weight-average molecular weight (Mw) of the (meth)acrylate polymer (A), the type and amount of the colorant (C), the amount of the silane coupling agent, and the thickness of the colored adhesive layer were changed to those shown in Table 1. In Example 5, 5.0 parts by mass of ε-caprolactone-modified tris(2-acryloyloxyethyl)isocyanurate (manufactured by SHIN-NAKAMURA CHEMICAL CO., LTD., product name "NKester A-9300-1CL") as an active energy ray-curable component (D) and 0.5 parts by mass of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide as a photopolymerization initiator (E) were further added to obtain an active energy ray-curable adhesive. Although the colorant (C) was not used in Comparative Example 1, the terms "colored adhesive layer" and "colored adhesive sheet" are used for convenience.

[0246] Separately, colored adhesive sheets of Examples 2 to 8 and Comparative Example 1 were produced as follows. Using a knife coater, a coating solution of an adhesive composition prepared in the same manner as in Example 1 was applied to the release-treated surface of a heavy-release release sheet (manufactured by Lintec Corporation, product name "SP-PET752150"), one side of which had been release-treated with a silicone release agent. The sheet was then heat-treated at 90°C for 1 minute to form a coating layer. The coating layer side of the resulting heavy-release release sheet with a coating layer was then bonded to the release-treated surface of a light-release release sheet (manufactured by Lintec Corporation, product name "SP-PET381130"), one side of which had been release-treated with a silicone release agent. The sheets were aged at 23°C and 50% RH for 7 days to produce colored adhesive sheets consisting of a heavy-release release sheet / colored adhesive layer / light-release release sheet.

[0247] The weight average molecular weight (Mw) is a polystyrene-equivalent weight average molecular weight measured using gel permeation chromatography (GPC) under the following conditions (GPC measurement).

[0248] <Measurement Conditions>

[0249] GPC measurement equipment: HLC-8020 manufactured by TOSOH CORPORATION

[0250] GPC column (passed in the following order): TSK guard column HXL-H manufactured by TOSOH CORPORATION

[0251] TSK gel GMHXL (×2)

[0252] TSK gel G2000HXL

[0253] ·Test solvent: tetrahydrofuran

[0254] ·Measurement temperature: 40℃

[0255] [Test Example 1] (Measurement of Haze Value of Colorant Dilution)

[0256] The haze value (%) of a solution prepared by diluting the C1 to C5 colorants 10,000 times with ethyl acetate was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000," optical path length 10 mm) in accordance with JIS K7136:2000. From these measured values, the difference between the haze value at a wavelength of 780 nm and the haze value at a wavelength of 380 nm, the average haze value (the average of the haze values at a wavelength of 780 nm and the haze values at a wavelength of 380 nm), and the standard deviation of the haze value at each wavelength at 5 nm intervals across the wavelength range of 380 nm to 780 nm were calculated. These results are shown in Table 2.

[0257] [Test Example 2] (Measurement of gel fraction)

[0258] The colored adhesive sheets obtained in the Examples and Comparative Examples were cut into 80 mm x 80 mm pieces. The colored adhesive layer was wrapped in a polyester mesh (mesh size 200). The mass was measured using a precision balance. The mass of the mesh alone was subtracted to calculate the mass of the adhesive alone. This mass was recorded as M1.

[0259] Next, the adhesive wrapped in the polyester mesh was immersed in ethyl acetate at room temperature (23°C) for 24 hours. Then, the adhesive was taken out and air-dried for 24 hours at a temperature of 23°C and a relative humidity of 50%, and further dried in an oven at 80°C for 12 hours. After drying, its mass was weighed with a precision balance, and the mass of the mesh alone was subtracted to calculate the mass of the adhesive itself. The mass at this time was recorded as M2. The gel fraction (%) was expressed as (M2 / M1)×100. The results are shown in Table 3.

[0260] In addition, for the colored adhesive sheet of Example 5, a plastic sheet (manufactured by MITSUBISHI GAS CHEMICAL COMPANY, INC., product name "iupilon-sheet MR58U," thickness: 0.7 mm, containing a UV absorber) consisting of a polymethyl methacrylate resin (PMMA) layer laminated on a polycarbonate resin (PC) sheet was placed on a light-peel release sheet. The colored adhesive layer was cured by irradiation with active energy rays under the following conditions through the plastic sheet. The gel fraction (after UV) of the adhesive in this cured colored adhesive layer was also derived in the same manner as above.

[0261] <Active Energy Ray Irradiation Conditions>

[0262] Use high-pressure mercury lamp

[0263] Illumination 200mW / cm 2 , light intensity 2000mJ / cm 2

[0264] The UV illuminance meter used was the "UVPF-A1" manufactured by Eye Graphics Co., Ltd.

[0265] [Test Example 3] (Measurement of storage modulus)

[0266] The release sheets were peeled off from the colored adhesive sheets obtained in Examples and Comparative Examples, and multiple colored adhesive layers were laminated to a thickness of 3 mm. Cylinders with a diameter of 8 mm (height 3 mm) were punched out from the obtained colored adhesive layer laminates to prepare samples.

[0267] The storage modulus (MPa) of the above sample was measured using a viscoelasticity measuring apparatus (manufactured by Physica, product name "MCR300") according to JIS K7244-6 by a torsional shear method under the following conditions.

[0268] Measuring frequency: 1Hz

[0269] Measurement temperature: 23°C

[0270] The colored adhesive sheet of Example 5 was irradiated with active energy rays in the same manner as in Test Example 2 to cure the colored adhesive layer, and the storage modulus (after UV) of the cured colored adhesive layer was also measured in the same manner as above.

[0271] [Test Example 4] (Measurement of Haze Value)

[0272] The haze value (%) of the colored adhesive layer of the colored adhesive sheet obtained in the Examples and Comparative Examples was measured using a haze meter (manufactured by NIPPON DENSHOKU INDUSTRIES Co., LTD., product name "SH-7000") in accordance with JIS K7136:2000. The total light haze value (%) obtained is shown in Table 3. In addition, the average haze value (the average of the haze value at a wavelength of 780 nm and the haze value at a wavelength of 380 nm), the difference between the haze value at a wavelength of 780 nm and the haze value at a wavelength of 380 nm, and the standard deviation of the haze value at each wavelength with a 5 nm interval in the wavelength range of 380 nm to 780 nm were calculated from the measured values. The results are shown in Table 3.

[0273] In addition, the colored adhesive sheet of Example 5 was irradiated with active energy rays in the same manner as in Test Example 2 to cure the colored adhesive layer. The total light haze value (after UV) of the cured colored adhesive layer was measured in the above manner. Then, from the measured values, the average haze (after UV) as the average of the haze value at a wavelength of 780 nm and the haze value at a wavelength of 380 nm, the difference between the haze value at a wavelength of 780 nm and the haze value at a wavelength of 380 nm (after UV), and the standard deviation of the haze value at each wavelength with a 5 nm interval in the wavelength range of 380 nm to 780 nm (after UV) were calculated. The results are shown in Table 3.

[0274] [Test Example 5] (Measurement of total light transmittance)

[0275] The colored adhesive layer of the colored adhesive sheet obtained in the Examples and Comparative Examples was attached to glass to serve as a measurement sample. After background measurement using glass, the total light transmittance (%) of the above-mentioned measurement sample was measured using a haze meter (manufactured by NIPPON DENSHOKU INDUSTRIES Co., LTD., product name "SH-7000") in accordance with JIS K7361-1:1997. Separately, the colored adhesive sheet of Example 5 was irradiated with active energy rays in the same manner as in Test Example 2 to cure the colored adhesive layer. The total light transmittance (after UV) of the cured colored adhesive layer was measured in the same manner as described above. The results are shown in Table 3.

[0276] [Test Example 6] (Measurement of L*a*b* of Colored Adhesive Layer)

[0277] The colored adhesive layers of the colored adhesive sheets obtained in the Examples and Comparative Examples were measured for lightness L*, chromaticity a*, and chromaticity b* as defined by the CIE 1976 L*a*b* color system using a simultaneous spectrophotometric colorimeter (manufactured by NIPPON DENSHOKU INDUSTRIES Co., LTD., product name "SQ2000"). Furthermore, the colored adhesive sheet of Example 5 was irradiated with active energy rays in the same manner as in Test Example 2 to cure the colored adhesive layer. The cured colored adhesive layer was then measured for lightness L* (after UV exposure), chromaticity a* (after UV exposure), and chromaticity b* (after UV exposure) in the same manner as described above. The results are shown in Table 3.

[0278] [Test Example 7] (Measurement of Adhesion Strength)

[0279] A light-peelable release sheet was peeled off from the colored adhesive sheets obtained in the Examples and Comparative Examples. The exposed colored adhesive layer was then attached to the easy-adhesive layer of a polyethylene terephthalate (PET) film (manufactured by TOYOBO CO., LTD., product name "PET A4300," thickness: 100 μm) having an easy-adhesive layer. This resulted in a release sheet / colored adhesive layer / PET film laminate. The resulting laminate was cut into pieces 25 mm wide and 100 mm long to prepare a sample.

[0280] Under conditions of 23°C and 50% RH, the heavy-peel release sheet was peeled from the sample, and the exposed colored adhesive layer was attached to soda-lime glass (manufactured by Nippon Sheet Glass Co., Ltd.). The sheet was then pressurized at 0.5 MPa and 50°C for 20 minutes using an autoclave manufactured by KURIHARASEISAKUSHO Co., Ltd. After standing for 24 hours under conditions of 23°C and 50% RH, the adhesive strength (N / 25 mm) was measured using a tensile testing machine (manufactured by ORIENTEC CORPORATION, product name "TENSILON") at a peel rate of 300 mm / min and a peel angle of 180 degrees. Conditions not described here were measured in accordance with JIS Z0237:2009. The results are shown in Table 3.

[0281] In addition, for the colored adhesive sheet of Example 5, the colored adhesive layer was attached to soda-lime glass in the same manner as described above, and after autoclaving, it was left to stand under the conditions of 23°C and 50% RH for 24 hours. Thereafter, the colored adhesive layer was irradiated with active energy rays in the same manner as in Test Example 2 to cure the colored adhesive layer. The adhesive strength (after UV) of the cured colored adhesive layer was also measured in the same manner as described above.

[0282] [Test Example 8] (Measurement of step-difference following rate)

[0283] On the surface of a glass plate (manufactured by NSG Precision Cells, Inc., product name "corning glass eagle XG", 90 mm long × 50 mm wide × 0.5 mm thick), a UV curable ink (manufactured by Teikoku Printing Inks Mfg. Co., Ltd., product name "POS-911 ink") was screen printed in a frame shape (outer dimensions: 90 mm long × 50 mm wide, 5 mm thick). Then, the glass plate was irradiated with UV rays (80 W / cm 2 , 2 metal halide lamps, lamp height 15 cm, belt speed 10-15 m / min), the printed ultraviolet curing ink is cured to produce a glass plate with a step difference based on the printing (the height of the step difference: any one of 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 50 μm, 60 μm and 70 μm).

[0284] The light-peel release sheet was peeled off from the colored adhesive sheets obtained in the Examples and Comparative Examples, and the exposed colored adhesive layer was bonded to the easy-adhesive layer of a polyethylene terephthalate film (manufactured by TOYOBO CO., LTD., product name "PET A4300," thickness: 100 μm) having an easy-adhesive layer. The heavy-peel release sheet was then peeled off to expose the colored adhesive layer. The laminated product was then laminated onto each stepped glass plate using a laminator (manufactured by FUJIPLA Inc., product name "LPD3214") so that the colored adhesive layer covered the entire frame-shaped printed surface. These samples were used as evaluation samples.

[0285] Under the conditions of 50°C and 0.5MPa, the obtained evaluation sample was subjected to a heat-pressing treatment for 30 minutes, and then placed at 23°C and 50%RH for 24 hours. Then, after being stored under high temperature and high humidity conditions of 85°C and 85%RH for 72 hours (durability test), the step followability was evaluated. The step followability is judged by whether the printed step is completely embedded in the colored adhesive layer. If bubbles, floating, peeling, etc. are observed at the interface between the printed step and the colored adhesive layer, it is judged that the printed step cannot be followed. Here, the step followability is evaluated by the step followability (%) shown in the following formula. The results are shown in Table 3.

[0286] Step following rate (%) = [(step height (μm) at which the embedded state is maintained without bubbles, floating, peeling, etc. after the durability test) / (thickness of the colored adhesive layer)] × 100

[0287] Separately, for the colored adhesive sheet of Example 5, a colored adhesive sheet having a colored adhesive layer thickness of 25 μm was prepared. Samples for evaluation obtained in the same manner as above were autoclaved and then left at 23°C and 50% RH for 24 hours. The colored adhesive layer was then cured by irradiation with active energy rays in the same manner as in Test Example 2. The cured colored adhesive layer was measured for its step-adjustability (after UV) in the same manner as above.

[0288] [Test Example 9] (Measurement and calculation of lightness L*)

[0289] Black background A (L*: 64.4, a*: -0.4, b*: 0.2), black background B (L*: 48.3, a*: 0.3, b*: -0.3) and black background C (L*: 27.9, a*: -0.2, b*: -0.1) were printed as backgrounds on one side of paper (100 mm long × 100 mm wide) to obtain three types of black substrates (black substrates having black backgrounds A to C). In addition, the color tones (L*a*b* specified by the CIE1976 L*a*b* colorimetric system) of the black backgrounds A to C of the obtained black substrates were measured (reflected light of the incident light from the black background side) using a spectrophotometer (manufactured by BYK, product name "Spectro-Guide"). The lightness L* of the black background A is set to L A , Set the lightness L* of the black background B to L B , set the lightness L* of the black background C to L C , and the respective measured values are shown in Table 4.

[0290] On the other hand, the colored adhesive sheets obtained in Examples and Comparative Examples were cut into pieces with a length of 70 mm.

[0291] The colored adhesive sheet was laminated so that its colored adhesive layer was sandwiched between two sheets of soda-lime glass (manufactured by Nippon Sheet Glass Co., Ltd., 70 mm long × 70 mm wide × 1.1 mm thick) to prepare a sample. Separately, the colored adhesive sheet of Example 5 was irradiated with active energy rays in the same manner as in Test Example 2 to cure the colored adhesive layer, and this was used as a sample.

[0292] The obtained samples were laminated on the three black substrates mentioned above, and the lightness L* (reflected light from the incident light on the sample side) of each was measured using a spectrophotometer (manufactured by BYK, product name "Spectro-Guide"). The lightness L* of the black background A laminated with the colored adhesive layer is L*. A ' represents the lightness L* of the black background B with the colored adhesive layer laminated thereon. B' represents the lightness L* of the black background C with the colored adhesive layer laminated thereon. C The results are shown in Table 4.

[0293] Furthermore, the following values were calculated from the above measurement results. The results are shown in Table 4.

[0294] ΔL AC =L A -L C

[0295] ΔL AC '=L A '-L C '

[0296] ·(ΔL AC ' / ΔL AC )×100

[0297] ΔL AB =L A -L B

[0298] ΔL AB '=L A '-L B '

[0299] ·(ΔL AB ' / ΔL AB )×100

[0300] ΔL BC =L B -L C

[0301] ΔL BC '=L B '-L C '

[0302] ·(ΔL BC ' / ΔL BC )×100

[0303] [Test Example 10] (Evaluation of design)

[0304] Using the black substrates having black backgrounds A to C obtained in the same manner as in Test Example 9, the following three types of boundary portions were formed.

[0305] Boundary (A / C): The black substrate with the black background C is stacked on the black substrate with the black background A in a staggered state to form the boundary (A / C) between the black background A and the black background C.

[0306] Boundary (A / B): The black substrate with the black background B is stacked on the black substrate with the black background A in a staggered state to form the boundary (A / B) between the black background A and the black background B.

[0307] Boundary (B / C): The black substrate with the black background C is stacked on the black substrate with the black background B in a staggered state to form a boundary (B / C) between the black backgrounds B and C.

[0308] Next, samples prepared in the same manner as in Test Example 9 were placed on a black background including a boundary. The visual appearance of the boundary (whether the boundary was conspicuous and whether the black background blended in) was visually assessed under a three-wavelength fluorescent lamp (distance from the lamp: 200 cm). The seamless design was evaluated using the following criteria.

[0309] The results are shown in Table 4.

[0310] ⊚: The boundary portion is hardly noticeable, and the black backgrounds blend into each other.

[0311] ○: The boundary is vaguely discernible, but it is not a problem, and the black backgrounds blend into each other.

[0312] ×: The boundary portion is conspicuous, and the black backgrounds do not blend in with each other.

[0313] [Test Example 11] (Evaluation of Text Visibility)

[0314] On a 15.6-inch display with a resolution of 1366×768 (manufactured by Fujitsu Limited, product name “LITEBOOK A574 / H”), white text (numerals, font: MS P Gothic) with a black background was displayed at 100% in sizes from 5 points to 20 points (in 1-point increments).

[0315] A sample prepared in the same manner as in Test Example 9 was placed on the display. The size of the recognizable text was visually confirmed from a distance of 100 cm from the display, and text visibility was evaluated using the following criteria. The results are shown in Table 4.

[0316] ◎: 8-point text can be recognized without any problems.

[0317] ○: 8-point characters cannot be fully recognized, but 10-point characters can be recognized without any problems.

[0318] ×: 10-point text cannot be recognized.

[0319] [Test Example 12] (Evaluation of wide-angle visibility)

[0320] A sample, prepared in the same manner as in Test Example 9, was placed directly in front of a monitor (Fujitsu Limited, product name "LITEBOOK A574 / H," 15.6 inches, 1366 x 768 resolution) with the monitor lit. The ARIB multiformat color bar was displayed on the monitor. The sample was then viewed from the front and at an angle (45°) under a three-wavelength fluorescent lamp (200 cm from the lamp). The visual quality of the monitor through the sample was evaluated with the naked eye. Visibility (wide-angle visibility) was evaluated according to the following criteria. The results are shown in Table 4.

[0321] ⊚: There is no difference in visual performance between the front view and the oblique view.

[0322] ○: The visual appearance when observed from an oblique surface becomes darker than the visual appearance when observed from the front, but the color tone does not change.

[0323] ×: The color tone of the visual appearance observed from the front and the visual appearance observed from an oblique surface is different.

[0324] In addition, in all examples, the screen was bright when viewed from the front, so the visibility of the image depending on the screen brightness was good.

[0325] [Table 1]

[0326] [Table 2]

[0327]

[0328]

[0329] As can be seen from the above table, the displays using the colored adhesive sheets obtained in Examples exhibit excellent design properties, particularly seamless design properties. Furthermore, the displays using the colored adhesive sheets obtained in Examples 1 to 7 also exhibit excellent visibility. Furthermore, the colored adhesive sheets obtained in Examples also exhibit excellent step-adjustability.

[0330] Industrial Applicability

[0331] The colored adhesive sheet of the present invention can be suitably used, for example, for laminating display components in a display having a black frame material, and can be particularly suitably used for laminating a protective panel having a step to a desired display component.

Claims

1. A display comprising: a first display component having at least two regions of different brightness in a planar direction; a second display component; and a colored adhesive layer for bonding the first display component and the second display component to each other, wherein: At least one of the first display component and the second display component has a step on at least the surface on the side to be bonded by the colored adhesive layer. The thickness of the colored adhesive layer is 1 μm or more and 150 μm or less. The gel fraction of the adhesive constituting the colored adhesive layer is 20% or more and 70% or less, The colorant in the colored adhesive layer is dark or dark in color, When the lightness L* of one region R1 of the first display component member defined by the CIE 1976 L*a*b* color system is defined as L1, the lightness L* of the other region R2 is defined as L2, the lightness L* of the region R1 on which the colored adhesive layer is laminated is defined as L1', and the lightness L* of the region R2 on which the colored adhesive layer is laminated is defined as L2', the following formulas (I) to (IV) are satisfied: ΔL=L1-L2···(I) ΔL'=L1'-L2'···(II) ΔL>0···(III) (ΔL' / ΔL)×100≤80···(IV).

2. A display comprising: a first display component having at least two regions of different brightness in a planar direction; a second display component; and a colored adhesive layer for bonding the first display component and the second display component to each other, wherein: At least one of the first display component and the second display component has a step on at least the surface on the side to be bonded by the colored adhesive layer. The thickness of the colored adhesive layer is 1 μm or more and 150 μm or less. The gel fraction of the adhesive constituting the colored adhesive layer is 20% or more and 70% or less, The colorant in the colored adhesive layer is dark or dark in color, When the lightness L* of one region R1 of the first display component member defined by the CIE 1976 L*a*b* color system is defined as L1, the lightness L* of the other region R2 is defined as L2, the lightness L* of the region R1 on which the colored adhesive layer is laminated is defined as L1', and the lightness L* of the region R2 on which the colored adhesive layer is laminated is defined as L2', the following formulas (I) to (IV) are satisfied: ΔL=L1-L2···(I) ΔL'=L1'-L2'···(II) ΔL>0···(III) (ΔL' / ΔL)×100≤80···(IV) The colored adhesive layer has a standard deviation of haze values at wavelengths of 5 nm intervals in a wavelength range of 380 nm to 780 nm of 0.1 or more.

3. The display according to claim 1 or 2, further satisfying the following formula (V): ΔL'≤30···(V).

4. The display according to claim 1 or 2, characterized in that The colored adhesive layer has a lightness L* defined by the CIE 1976 L*a*b* color system of 5 or more and 95 or less.

5. The display according to claim 1 or 2, characterized in that The chromaticity a* and chromaticity b* of the colored adhesive layer as defined by the CIE 1976 L*a*b* color system are respectively -7 to 7.

6. The display according to claim 1 or 2, characterized in that The total light transmittance of the colored adhesive layer is greater than 30%.

7. The display according to claim 1 or 2, characterized in that: The colored adhesive layer has a total light haze value of 0.5% or more and 40% or less.

8. The display according to claim 1 or 2, characterized in that The adhesive is an acrylic adhesive.

9. The display according to claim 1 or 2, characterized in that: It has a black frame material.

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