CN116355548A

CN116355548A - Colored adhesive sheet and display

Info

Publication number: CN116355548A
Application number: CN202310350664.XA
Authority: CN
Inventors: 小鲭翔; 高桥洋一; 荒井隆行
Original assignee: Lintec Corp
Current assignee: Lintec Corp
Priority date: 2019-03-29
Filing date: 2020-03-27
Publication date: 2023-06-30
Also published as: CN111748300B; CN111748300A

Abstract

The invention provides a colored adhesive sheet capable of improving the design of a display body and the display body with improved design. The colored adhesive sheet (1) is provided with a colored adhesive layer (11) which satisfies the following formulas (I) - (IV) when the brightness L of one region R1 of a display body constituent member defined by CIE1976L x a x b x a color system is L1, the brightness L of the other region R2 is L2, the brightness L of the region R1 in which the colored adhesive layer (11) is laminated is L1', and the brightness L of the region R2 in which the colored adhesive layer (11) is laminated is L2': Δl=l1-l2· (I) Δl '=l1' -L2'· (II) Δl > 0· (III) (Δl'/Δl) ×100+.80· (IV).

Description

Colored adhesive sheet and display

The present invention is a divisional application of chinese patent application having application number 202010229821.8, application date 2020, month 27, and the name of "colored adhesive sheet and display", and the present application claims priority from japanese patent application publication No. 2019-068290 filed in japan at date 03, and from japanese patent application publication No. 2019-171774 filed in japan at date 09, 20.

Technical Field

The present invention relates to a colored adhesive sheet for bonding display element components and a display element using the same.

Background

In recent years, image display devices such as liquid crystal display devices and organic electroluminescence devices have been increasingly used as display devices (displays) in recent years, for example, in-vehicle display devices provided in instrument panels of automobiles, various instruments of automobile navigation systems and consoles, display devices such as tablet terminals used by general users, display devices such as commercial tablet terminals and digital signage, display devices such as digital signage used outdoors, and the like.

As described above, in a display body typified by a vehicle-mounted display, the display body may be required to exhibit an overall feeling with surrounding members of the display body, for example, a frame material, when the display body is turned off, and to improve design. For this reason, coloring of a display body is considered, and for example, patent documents 1 to 4 disclose inventions related to coloring of a display body.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2000-313871

Patent document 2: japanese patent laid-open No. 2009-188298

Patent document 3: japanese patent application laid-open No. 2012-234028

Patent document 4: japanese patent laid-open No. 2017-57375

Disclosure of Invention

Technical problem to be solved by the invention

However, the techniques disclosed in patent documents 1 to 4 are different in the purpose of coloring, and thus cannot provide a sense of unity between the display body and surrounding members, thereby improving the design. Further, since the types of surrounding members are also various, it is necessary to change the adhesive to a specification suitable for various members according to the types of surrounding members, and thus there is a problem that the degree of freedom in designing the adhesive is low and the management in manufacturing is complicated.

The present invention has been made in view of the above-described 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.

Technical means for solving the technical problems

In order to achieve the above object, in a first aspect, the present invention provides a colored adhesive sheet comprising a colored adhesive layer comprising an adhesive containing a colorant, and attached to a display element constituting member having at least two regions having different brightness in a planar direction, wherein when the brightness L of one region R1 of the display element constituting member defined by the CIE1976l×a×b is L1, the brightness L of the other region R2 is L2, the brightness L of the region R1 on which the colored adhesive layer is laminated is L1', and the brightness L of the region R2 on which the colored adhesive layer is laminated is L2', the following formulas (I) to (IV) are satisfied (invention 1).

ΔL＝L1-L2 ···(I)

ΔL’＝L1’-L2’ ···(II)

ΔL＞0 ···(III)

(ΔL’/ΔL)×100≤80 ···(IV)

When the colored adhesive sheet of the invention (1) is applied to a display body, the design of the display body at the time of turning off the light of the display body can be improved, and for example, the appearance compatibility at the time of turning off the light can be improved.

In the above invention (invention 1), the following formula (V) (invention 2) is preferably further satisfied.

ΔL’≤30···(V)

In the above inventions (inventions 1 and 2), the colored adhesive layer preferably has a brightness L defined by CIE1976l×a×b×color system of 5 to 95 (invention 3).

In the above inventions (inventions 1 to 3), the chromaticity a and the chromaticity b defined by the CIE1976l×a×b×color system of the colored adhesive layer are preferably-7 to 7, respectively (invention 4).

In the inventions (inventions 1 to 4), the total light transmittance of the colored adhesive layer is preferably 30% or more (invention 5).

In the above inventions (inventions 1 to 5), the colored adhesive layer preferably has a total haze value (total haze value) of 0.5% to 40% inclusive (invention 6).

In the above inventions (inventions 1 to 6), it is preferable that the average haze of a solution obtained by diluting the colorant with ethyl acetate 1 ten thousand times, which is an average value of the haze value at the wavelength of 780nm and the haze value at the wavelength of 380nm, is 1% to 60% (invention 7).

In the above inventions (inventions 1 to 7), it is preferable that the difference between the haze value at the wavelength of 780nm and the haze value at the wavelength of 380nm in a solution obtained by diluting the colorant 1 ten thousand times with ethyl acetate is 30% or less (invention 8).

In the above inventions (inventions 1 to 8), the colorant is preferably a black pigment (invention 9).

In the above inventions (inventions 1 to 9), the adhesive is preferably an acrylic adhesive (invention 10).

In the above inventions (inventions 1 to 10), the adhesive is preferably formed by crosslinking an adhesive composition containing a (meth) acrylate polymer (a), a crosslinking agent (B) and a colorant (C) (invention 11).

In the above inventions (inventions 1 to 11), the colored adhesive sheet preferably comprises: two release sheets, and the colored adhesive layer sandwiched between the release sheets so as to be in contact with the release surfaces of the two release sheets (invention 12).

In the above inventions (inventions 1 to 12), the colored adhesive sheet is preferably used for bonding the display constituent member and a display constituent member different from the display constituent member (invention 13).

In a second aspect, the present invention provides a display device comprising: the display is characterized in that when L x of one region R1 of the first display component is L1, L x of the other region R2 is L2, L x of the region R1 on which the colored adhesive layer is laminated is L1', and L x of the region R2 on which the colored adhesive layer is laminated is L2', the following formulas (I) to (IV) are satisfied (invention 14).

ΔL＝L1-L2 ···(I)

ΔL’＝L1’-L2’ ···(II)

ΔL＞0 ···(III)

(ΔL’/ΔL)×100≤80 ···(IV)

In the invention (invention 14), at least one of the first display element-constituting member and the second display element-constituting member may have a step difference on at least a surface on the side to which the colored adhesive layer is attached (invention 15).

In the above inventions (inventions 14 and 15), a black frame material (invention 16) may be provided.

Effects of the invention

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 body of the present invention is improved.

Drawings

Fig. 1 is a cross-sectional view of a colored adhesive sheet according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view of a display body according to an embodiment of the present invention.

Fig. 3 is a plan view of a display body with a frame material according to an embodiment of the present invention.

Description of the reference numerals

1: coloring the adhesive sheet; 11: coloring the adhesive layer; 12a, 12b: a release sheet; 2: a display body; 21: a first display body constituting member; 22: a second display body constituting member; 3: printing a layer; 4: and (5) a frame material.

Detailed Description

Hereinafter, embodiments of the present invention will be described.

[ colored adhesive sheet ]

The colored adhesive sheet according to one embodiment of the present invention is preferably formed by laminating a release sheet on one side or both sides of a colored adhesive layer to be attached to a display element constituting member having at least two regions having different brightness in the planar direction, the colored adhesive layer being composed of an adhesive containing a colorant. The colored adhesive sheet according to the present embodiment is preferably used for bonding the display element constituting member and a display element constituting member different from the display element constituting member. The display body and the display body constituent member will be described later.

Fig. 1 shows a specific structure of an example of the colored adhesive sheet according to the present embodiment.

As shown in fig. 1, the colored adhesive sheet 1 is composed of two

release sheets

12a, 12b and a colored adhesive layer 11, and the colored adhesive layer 11 is sandwiched between the two

release sheets

12a, 12b so as to be in contact with the release surfaces of the two

release sheets

12a, 12 b. The release surface of the release sheet in the present specification means a surface having releasability in the release sheet, and includes any one of a surface subjected to a release treatment and a surface exhibiting releasability even if the release treatment is not performed.

1. Each component is provided with

1-1 colored adhesive layer

Regarding the colored adhesive sheet 1 of the present embodiment, when the lightness L defined by the CIE1976L a b color system is L, the lightness L of one region R1 of the display body constituting member (adherend) having at least two regions having different lightness in the planar direction is L1, the lightness L of the other region R2 is L2, the lightness L of the region R1 on which the colored adhesive layer 11 is laminated is L1', and the lightness L of the region R2 on which the colored adhesive layer 11 is laminated is L2', the following formulas (I) to (IV) are satisfied, and the following formulas (V) are preferably further satisfied.

ΔL＝L1-L2 ···(I)

ΔL’＝L1’-L2’ ···(II)

ΔL＞0 ···(III)

(ΔL’/ΔL)×100≤80 ···(IV)

ΔL’≤30 ···(V)

The measurement method of the brightness L in the present specification is as shown in the test example described below. The reflected light from the display element constituent member was measured for the measurement of L1 and L2, and the reflected light from the incident light on the colored adhesive layer 11 side was measured for the measurement of L1 'and L2'. The display element constituting member is preferably black.

When the colored adhesive layer 11 satisfying the above conditions is applied to a display having the above display constituent member, the design of the display at the time of turning off the light can be improved. As an example of the design, there is an appearance coordination at the time of turning off the lamp. Specifically, when the display body is turned off, the boundary between the display portion and the surrounding members, for example, the boundary between the black frame material and the black printed layer can be hardly distinguished (seamless). Thus, the sense of unity of the display body and surrounding members when the display body is turned off is improved. In addition, even when a plurality of peripheral members (for example, black frame materials or black print layers) are present, it is possible to achieve the respective appearance coordination of the display body and each of the peripheral members or the appearance coordination (seamless) of the peripheral members. Therefore, since there are many members capable of achieving the compatibility of the appearance, the adhesive constituting the colored adhesive layer 11 has high versatility and the degree of freedom of design increases.

From the above point of view, the value of (Δl'/Δl) ×100 is required 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 value of (Δl'/Δl) ×100 is not particularly limited, but is preferably 10 or more, more preferably 15 or more, particularly preferably 20 or more, and further preferably 30 or more, from the viewpoint of simultaneously satisfying the visibility of the image and the video of the obtained display.

When Δl exceeds 0, the brightness L1 of one region R1 of the display element-constituting member (adherend) is different from the brightness L2 of the other region R2, and it can be said that the display element-constituting member has at least two regions having different brightness in the planar direction. Here, as the value of Δl approaches 0, the appearance of the region R1 and the region R2 of the display body constituent member becomes closer, and the appearance compatibility is likely to be good in visual evaluation; conversely, if the Δl value is large, it tends to be difficult to control the appearance coordination. Even in such a region where it is generally difficult to control the appearance coordination, the colored adhesive layer 11 of the present embodiment can sufficiently exhibit the improvement of the appearance coordination (design) by satisfying the formula (IV).

As shown in formula (III), the value of Δl may be more than 0, but is preferably 5 or more, more preferably 10 or more, particularly preferably 20 or more, further preferably 30 or more, and most preferably 35 or more, from the viewpoint of improving the accuracy of the appearance compatibility determination based on formula (IV). Similarly, the upper limit value of Δl is preferably 100 or less, more preferably 75 or less, particularly preferably 50 or less, and further preferably 40 or less, from the viewpoint of improving the accuracy of the appearance coordination determination.

As shown in the formula (V), the value of Δl' is preferably 30 or less, more preferably 25 or less, particularly preferably 20 or less, and further preferably 15 or less, from the viewpoint of improving the external appearance compatibility of the display. On the other hand, the lower limit value of Δl' is not particularly limited, but is preferably 1.5 or more, more preferably 3 or more, particularly preferably 4 or more, and even more preferably 5 or more, from the viewpoint of improving the accuracy of the external appearance coordination determination based on the formula (IV) and of achieving both the visibility of the image and the video of the obtained display.

The lightness L of the colored adhesive layer 11 defined by the CIE1976l×a×b color system is preferably 95 or less, more preferably 92 or less, particularly preferably 90 or less, and further preferably 88 or less. This makes it easy to satisfy the above formula (IV) (and formula (V)). The brightness L is preferably 5 or more, more preferably 20 or more, particularly preferably 50 or more, further preferably 70 or more, and most preferably 80 or more. This makes it easy to satisfy the above formula (IV) (and formula (V)), and the visibility of the image and video of the obtained display body is easy to be improved.

The average haze of the colored adhesive layer 11 according to the present embodiment, which is an average value of the haze value at the wavelength of 780nm and the haze value at the 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. This makes it easy to satisfy the above formula (IV) (and formula (V)). The average haze is preferably 60% or less, more preferably 40% or less, particularly preferably 30% or less, from the viewpoint of easily satisfying the above formula (IV) (and formula (V)), and is preferably 20% or less, particularly preferably 12% or less, more preferably 5% or less, from the viewpoint of easily improving the visibility of the image and the video of the obtained display. In addition, the haze value in the present specification is a value measured in accordance with JIS K7136:2000.

The difference (absolute value) between the haze value at the wavelength of 780nm and the haze value at the wavelength of 380nm of the colored adhesive layer 11 of the present embodiment is preferably 15% or less, particularly preferably 10% or less, and further preferably 7% or less. Thus, when the colored adhesive layer 11 of the present embodiment is applied to a display body, the balance of color tone on the screen does not change regardless of the observation position or angle when the display body is lighted. As a result, when the display body is lit, the visibility (wide-angle visibility) of the image and video when viewed at a wide angle is improved, and a good image quality can be provided.

The lower limit value of the difference in haze value may be 0 percentage point, but 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, from the viewpoint that the average haze can be easily adjusted to a desired value.

The haze value of the colored adhesive layer 11 of the present embodiment at the wavelength of 780nm is preferably 0.1 to 50%, more preferably 0.2 to 25%, still more preferably 0.5 to 15%, particularly preferably 0.7 to 7%, still more preferably 1 to 3%, from the viewpoint of easily adjusting the difference in the average haze and the haze value and the standard deviation of the haze value to desired values.

Further, in view of the easiness of adjusting the difference between the average haze and the haze value and the standard deviation of the haze value to be described later to desired values, the haze value of the colored adhesive layer 11 of the present embodiment at the wavelength of 380nm 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%.

The standard deviation of the haze value of the colored adhesive layer 11 of the present embodiment at each wavelength (i.e., 380nm, 385nm, 390nm, 775nm, 780 nm) at a 5nm pitch in the wavelength region of 380nm to 780nm is preferably 5 or less, particularly preferably 3 or less, and further preferably 2 or less. Thus, when the colored adhesive layer 11 of the present embodiment is applied to a display body, the balance of color tone on the screen does not change regardless of the observation position or angle when the display body is lighted. As a result, when the display body is lit, the visibility (wide-angle visibility) of the image and video when viewed at a wide angle is improved, and a good image quality can be provided.

The lower limit of the standard deviation is usually 0 or more, but 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, from the viewpoint of easily satisfying the above formula (IV) (and formula (V)).

The colored adhesive layer 11 of the present embodiment preferably has a total light haze value of 0.5% or more, more preferably 1% or more, particularly preferably 2% or more, and further preferably 3% or more. This makes it easy to satisfy the above formula (IV) (and formula (V)). On the other hand, the total light haze value is preferably 40% or less, more preferably 30% or less, particularly preferably 20% or less, further preferably 10% or less, and most preferably 5% or less. Thus, visibility as a display is easily improved.

The total light transmittance (value measured in accordance with JIS K7361-1:1997) of the colored adhesive layer 11 of the present embodiment is usually 100% or less, preferably 98% or less, more preferably 90% or less, particularly preferably 70% or less, and further preferably 50% or less. This makes it easy to satisfy the above formula (IV) (and formula (V)). On the other hand, the total light transmittance is preferably 30% or more, more preferably 35% or more, particularly preferably 40% or more, and further preferably 45% or more. Thus, visibility as a display is easily improved.

The surrounding members include, specifically, an automobile instrument panel having a luminance L of 23.2, a chromaticity a of-0.5, and a chromaticity b of-1.5 defined by the CIE1976L x b x color system. The color tone of the surrounding member is preferably 5 to 90, the chromaticity a is-40 to 40, the chromaticity b is-40 to 40, the luminance L is particularly preferably 10 to 80, the chromaticity a is-30 to 30, the chromaticity b is-30 to 30, the luminance L is further preferably 15 to 70, the chromaticity a is-20 to 20, and the chromaticity b is-20 to 20. The colored adhesive sheet 1 of the present embodiment can be suitably used for a display body having the above-described color tone of surrounding members.

From the viewpoint of the design of the display, the chromaticity a defined by the CIE1976l×a×b×color system of the colored adhesive layer 11 is preferably-7 to 7, more preferably-5 to 5, particularly preferably-3 to 3, and further preferably-1 to 1. Further, from the viewpoint of the design of the display, the chromaticity b of the colored adhesive layer 11 defined by the CIE1976l×a×b×color system is preferably from-7 to 7, more preferably from-5 to 5, particularly preferably from-3 to 3, and even more preferably from-1 to 1. In the present specification, the measurement methods of chromaticity a and chromaticity b are as follows.

By satisfying the above optical properties in the colored adhesive layer 11, when applied to a display, the blackness increases when the display is turned off, and thus the design of the display (for example, the appearance compatibility when the display is turned off) can be further improved. Specifically, the display body, particularly the vehicle-mounted display body, can further improve the sense of unity with surrounding members, for example, with a black frame material.

The above optical properties can be achieved by appropriately selecting the kind and content of the colorant contained in the adhesive constituting the colored adhesive layer 11.

The lower limit value of the average haze, which is an average value of the haze value at the wavelength of 780nm and the haze value at the wavelength of 380nm, of a solution obtained by diluting the colorant with ethyl acetate by 1 ten thousand times is preferably 1% or more, particularly preferably 2% or more, and further preferably 3% or more. The upper limit of the average haze of the colorant is preferably 60% or less, more preferably 40% or less, still more preferably 25% or less, particularly preferably 15% or less, further preferably 8% or less, and particularly preferably 5% or less from the viewpoint of both visibility. By using such a colorant in an appropriate amount, the resulting colored adhesive layer 11 can easily satisfy the above optical properties and can easily satisfy the above formula (IV) (and formula (V)).

The difference between the haze value at the wavelength of 780nm and the haze value at the wavelength of 380nm in a solution obtained by diluting the colorant with ethyl acetate 1 ten thousand times is preferably 30% or less, more preferably 25% or less, particularly preferably 20% or less, and further preferably 14% or less. By using such a colorant in an appropriate amount, the resulting colored adhesive layer 11 can easily satisfy the above optical properties and can easily satisfy the above formula (IV) (and formula (V)).

The lower limit value of the difference in haze value may be 0% or more, but is preferably 1% or more, particularly preferably 4% or more, from the standpoint that the obtained colored adhesive layer 11 easily satisfies the optical properties and the formula (IV) (and formula (V)) and is preferably 7.5% or more, from the standpoint of both visibility.

The haze value at 780nm of the solution obtained by diluting the colorant with ethyl acetate 1 ten thousand times is preferably 0.1 to 50%, more preferably 0.5 to 25%, particularly preferably 0.8 to 15%, further preferably 1 to 3%, and most preferably 2 to 2.5%. The haze value at 380nm of the solution obtained by diluting the colorant with ethyl acetate 1 ten thousand times is preferably 1 to 60%, more preferably 3 to 30%, particularly preferably 6 to 20%, and further preferably 10 to 15%. Thus, the obtained colored adhesive layer 11 easily satisfies the above optical properties and the above formula (IV) (and formula (V)).

Further, the standard deviation of the haze value at each wavelength (i.e., 380nm, 385nm, 390nm, 775nm, 780 nm) of the 5nm pitch in the wavelength region of 380nm to 780nm of the solution obtained by diluting the above colorant 1 ten thousand times with ethyl acetate is preferably 10 or less, more preferably 6 or less, particularly preferably 3 or less, and further preferably 1.8 or less. The lower limit of the standard deviation is most preferably 0, and is usually preferably 0.1 or more, more preferably 0.3 or more, particularly preferably 0.5 or more, and further preferably 1 or more. Thus, the obtained colored adhesive layer 11 easily satisfies the above optical properties and the above formula (IV) (and formula (V)).

The colorant may be a pigment or a dye. The pigment may be an inorganic pigment or an organic pigment. From the viewpoint of durability of the obtained adhesive, an inorganic pigment is preferable. The color of the colorant may be appropriately selected according to the color of the surrounding member to be given the sense of unity, and is usually preferably a dark color or a dark color such as black, brown, navy, purple, blue, and particularly preferably black.

Examples of the inorganic pigment include carbon black, cobalt-based pigment, iron-based pigment, chromium-based pigment, titanium-based pigment, vanadium-based pigment, zirconium-based pigment, molybdenum-based pigment, ruthenium-based pigment, platinum-based pigment, ITO (indium tin oxide) based pigment, ATO (tin antimony oxide) based pigment, and the like.

Examples of the organic pigment and organic dye include amine (amium) pigment, cyanine pigment, merocyanine pigment, croconium pigment, squaraine (croconium) pigment, squaraine (squarylium) pigment, azulene (azulenium) pigment, polymethine pigment, naphthoquinone pigment, pyrylium pigment, phthalocyanine pigment, naphthalocyanine pigment, naphthalenium (naphthalolactam) pigment, azo pigment, condensed azo pigment, indigo pigment, cyclic ketone pigment, perylene pigment, dioxazine pigment, quinacridone pigment, isoindolinone pigment, quinolinone pigment, pyrrole pigment, thioindigo pigment, metal complex pigment (metal complex dye), dithiol metal complex pigment, indophenol pigment, triarylmethane pigment, anthraquinone pigment, dioxazine pigment, naphthol pigment, azone pigment, benzoquinone pigment, anthraketone pigment, and xanthone pigment.

Examples of the black pigment include carbon black, copper oxide, ferroferric oxide, manganese dioxide, nigrosine, and activated carbon. Examples of the black dye include a high-concentration vegetable dye and an azo dye.

The pigment or dye can be mixed with the colored adhesive layer 11 as appropriate to obtain the target physical properties.

Among the above colorants, carbon black, nigrosine-based black dyes and chromate-based black dyes are preferred in that the above physical properties are easily satisfied and the feel of the colorant to the surrounding members is easily exhibited. The surface of carbon black may or may not be subjected to a predetermined treatment (for example, a solvation treatment).

The type of adhesive constituting the colored adhesive layer 11 of the colored adhesive sheet 1 of the present embodiment is not particularly limited, and may be any of, for example, an acrylic adhesive, a polyester adhesive, a polyurethane adhesive, a rubber adhesive, a silicone adhesive, and the like. The adhesive may be any of emulsion type, solvent type and solvent-free type, or may be any of crosslinked type and non-crosslinked type. Among them, an acrylic adhesive excellent in adhesive properties, optical properties and the like is preferable.

The acrylic pressure-sensitive adhesive may be active energy ray-curable or inactive energy ray-curable. The acrylic adhesive is preferably a crosslinked acrylic adhesive, and more preferably a thermally crosslinked acrylic adhesive.

Specifically, the adhesive is preferably crosslinked with 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). In the case where the adhesive is an active energy ray-curable adhesive, the adhesive composition P preferably further contains an active energy ray-curable component (D).

The colorant (C) contained in the adhesive composition P is the above colorant. The adhesive obtained from the adhesive composition P can exhibit excellent optical properties, adhesive force, durability (step following property under high-temperature and high-humidity conditions), and the like. In the present specification, (meth) acrylic acid means acrylic acid and methacrylic acid. Other similar terms are also the same. In addition, "polymer" includes the concept of "copolymer".

(1) Ingredients of adhesive composition

(1-1) (meth) acrylate Polymer (A)

The (meth) acrylate polymer (a) of the present embodiment preferably contains, as a monomer unit constituting the polymer, a reactive group-containing monomer having a reactive group reactive with the crosslinking agent (B) in a molecule. By reacting the reactive group derived from the reactive group-containing monomer with the crosslinking agent (B), a crosslinked structure (a steric network structure) can be formed, and an adhesive having a desired cohesive force can be obtained.

The reactive group-containing monomer may preferably be a monomer having a hydroxyl group in a molecule (hydroxyl group-containing monomer), a monomer having a carboxyl group in a molecule (carboxyl group-containing monomer), a monomer having an amino group in a molecule (amino group-containing monomer), or the like. Among them, a hydroxyl group-containing monomer or a carboxyl group-containing monomer having excellent reactivity with the crosslinking agent (B) is preferable, and a hydroxyl group-containing monomer and a carboxyl group-containing monomer are also preferably used simultaneously.

Examples of the hydroxyl group-containing monomer 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 them, from the points of reactivity of hydroxyl groups with the crosslinking agent (B) and copolymerizability with other monomers in the obtained (meth) acrylate polymer (a), hydroxyalkyl (meth) acrylates having a hydroxyalkyl group having 1 to 4 carbon atoms are preferable. Specifically, for example, 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate and the like are preferable, and 2-hydroxyethyl acrylate or 4-hydroxybutyl acrylate is particularly preferable. These hydroxyl group-containing monomers may be used alone or in combination of two or more.

Examples of the carboxyl group-containing monomer include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. Among them, acrylic acid is preferable from the points of reactivity of carboxyl groups with the crosslinking agent (B) and copolymerization with other monomers in the obtained (meth) acrylate polymer (a). These carboxyl group-containing monomers may be used alone or in combination of two or more.

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

The (meth) acrylate polymer (a) preferably contains a reactive group-containing monomer having a lower limit of 1 mass% or more, more preferably 5 mass% or more, and particularly preferably 10 mass% or more as a monomer unit constituting the polymer. Further, since the dispersibility of the colorant (C) in the adhesive tends to be more excellent, it is more preferably 12 mass% or more, and most preferably 15 mass% or more. On the other hand, the (meth) acrylate polymer (a) preferably contains a reactive group-containing monomer having an upper limit of 35 mass% or less, more preferably 30 mass% or less, and particularly preferably 20 mass% or less, as a monomer unit constituting the polymer. Further, the colorant (C) in the adhesive tends to be more excellent in dispersibility, and thus is more preferably contained at 18 mass% or less. When the (meth) acrylate polymer (a) contains the reactive group-containing monomer as a monomer unit in the above-described amount, a good crosslinked structure can be formed in the obtained adhesive, and a desired cohesive force can be obtained. Further, the dispersibility of the colorant (C) in the adhesive tends to be excellent, and the reproducibility and uniformity of the optical properties of the obtained adhesive are excellent, and the adhesive can easily satisfy the above formula (IV) (and formula (V)), and exhibits excellent design properties and visibility. Further, when the reactive group-containing monomer is a hydroxyl group-containing monomer, the content is particularly preferably 15 mass% or more. At this time, a predetermined amount of hydroxyl groups remain in the adhesive. When the hydroxyl group is a hydrophilic group and such a hydrophilic group is present in a predetermined amount in the adhesive, compatibility with moisture immersed in the adhesive under high temperature and high humidity conditions is good even when the adhesive is placed under the high temperature and high humidity conditions, and as a result, whitening of the adhesive upon recovery to normal temperature and normal humidity is suppressed (excellent wet heat whitening resistance).

In addition, the (meth) acrylate polymer (a) preferably does not contain a carboxyl group-containing monomer as a monomer unit constituting the polymer. Since the carboxyl group is an acid component, the presence of the carboxyl group-containing monomer can suppress the above-described adverse conditions (corrosion, change in resistance value, etc.) caused by the acid even when a substance causing adverse conditions due to the acid, for example, a transparent conductive film such as tin-doped indium oxide (ITO), a metal film, or the like, is present on the object to be adhered with the adhesive. However, it is also permissible to contain a predetermined amount of the carboxyl group-containing monomer to such an extent that the above-mentioned disadvantages do not occur. Specifically, the (meth) acrylate polymer (a) may contain a carboxyl group-containing monomer as a monomer unit in an amount of 0.1 mass% or less, preferably 0.01 mass% or less, and more preferably 0.001 mass% or less.

The (meth) acrylic acid ester polymer (a) preferably contains an alkyl (meth) acrylate as a monomer unit constituting the polymer. This can exhibit good adhesion. The alkyl group may be linear or branched.

From the viewpoints of adhesion and dispersibility of the colorant (C), the alkyl (meth) acrylate is preferably one in which the alkyl group has 1 to 20 carbon atoms. Examples of the alkyl (meth) acrylate having 1 to 20 carbon atoms in the alkyl group 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 them, from the viewpoint of further improving the adhesion, a (meth) acrylic acid ester in which the carbon number of the alkyl group is 1 to 8 is preferable, methyl (meth) acrylate, n-butyl (meth) acrylate or 2-ethylhexyl (meth) acrylate is particularly preferable, and methyl methacrylate, n-butyl acrylate or 2-ethylhexyl acrylate is further preferable. These alkyl (meth) acrylates may be used alone or in combination of two or more.

The (meth) acrylic acid ester polymer (a) preferably contains 50 mass% or more, particularly preferably 60 mass% or more, and further preferably 65 mass% or more of an alkyl (meth) acrylate as a monomer unit constituting the polymer. When the lower limit of the content of the alkyl (meth) acrylate is the above, the (meth) acrylate polymer (a) can exhibit an appropriate tackiness. In addition, the dispersibility of the colorant (C) in the adhesive tends to be good, and the (meth) acrylate polymer (a) does not impair the desired adhesiveness. The adhesive thus obtained exhibits suitable adhesion, and at the same time, the reproducibility and uniformity of the optical properties are improved, and the adhesive can easily satisfy the above formula (IV) (and formula (V)), thereby exhibiting excellent design properties and visibility. On the other hand, the (meth) acrylic acid ester polymer (a) preferably contains 99 mass% or less, more preferably 95 mass% or less, particularly preferably 90 mass% or less, and further preferably 85 mass% or less of an alkyl (meth) acrylate as a monomer unit constituting the polymer. When the upper limit of the content of the alkyl (meth) acrylate is the above, other monomer components such as a reactive functional group-containing monomer can be introduced into the (meth) acrylate polymer (a) in an appropriate amount.

The (meth) acrylate polymer (a) preferably contains a monomer having an alicyclic structure in the molecule (alicyclic structure-containing monomer) as a monomer unit constituting the polymer. Since the alicyclic structure-containing monomer has a large volume, it is presumed that the presence of the alicyclic structure-containing monomer in the polymer enlarges the interval between the polymers, and the resulting adhesive is excellent in flexibility. This makes the adhesive excellent in step following performance.

The alicyclic structure-containing carbon ring in the alicyclic structure-containing monomer may have a saturated structure or may have an unsaturated bond in a part thereof. The alicyclic structure may be a monocyclic alicyclic structure, or may be a polycyclic alicyclic structure such as a bicyclic or tricyclic structure. The alicyclic structure is preferably a polycyclic alicyclic structure (polycyclic structure) in terms of providing a suitable distance between the obtained (meth) acrylate polymers (a) and imparting a higher stress relaxation property to the adhesive. Further, the polycyclic structure is particularly preferably a bicyclic to tetracyclic in view of compatibility of the (meth) acrylate polymer (a) with other components. In addition, as described above, from the viewpoint of imparting stress relaxation, the number of carbon atoms of the alicyclic structure (the number of carbon atoms in the whole of the portion forming the ring, and the total number of carbon atoms when a plurality of rings are independently present) is usually 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, particularly preferably 10 or less, from the viewpoint of compatibility as described above.

Specific examples of the alicyclic structure-containing monomer include cyclohexyl (meth) acrylate, dicyclopentyl (meth) acrylate, adamantyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and the like, and among them, dicyclopentyl (meth) acrylate (the number of carbon atoms of the alicyclic structure: 10), adamantyl (meth) acrylate (the number of carbon atoms of the alicyclic structure: 10), or isobornyl (meth) acrylate (the number of carbon atoms of the alicyclic structure: 7) is preferable, isobornyl (meth) acrylate is particularly preferable, and isobornyl (meth) acrylate is further preferable. These alicyclic structure-containing monomers may be used singly or in combination of two or more.

When the (meth) acrylate polymer (a) contains an alicyclic structure-containing monomer as a monomer unit constituting the polymer, the alicyclic structure-containing monomer is preferably contained in an amount of 1 mass% or more, particularly preferably 4 mass% or more, and further preferably 8 mass% or more. The (meth) acrylate polymer (a) preferably contains 30 mass% or less, particularly preferably 22 mass% or less, and further preferably 14 mass% or less of an alicyclic structure-containing monomer as a monomer unit constituting the polymer. When the content of the alicyclic structure-containing monomer is within the above range, the obtained adhesive is more excellent in step-following property and adhesion to plastics.

The (meth) acrylate polymer (a) preferably further contains a nitrogen atom-containing monomer as a monomer unit constituting the polymer. By providing the nitrogen atom-containing monomer as a structural unit in the polymer, a predetermined polarity can be imparted to the adhesive, and the adhesive can have excellent affinity even for an adherend having a certain degree of polarity such as glass. From the viewpoint of imparting suitable rigidity to the (meth) acrylate polymer (a), the monomer having a nitrogen-containing heterocyclic ring is preferable as the monomer having a nitrogen atom. In addition, from the viewpoint of improving the degree of freedom of the portion derived from the nitrogen atom-containing monomer in the high-dimensional structure of the adhesive formed, it is preferable that the nitrogen atom-containing monomer not contain a reactive unsaturated double bond group other than one polymerizable group used in the polymerization for forming the (meth) acrylate polymer (a).

Examples of the monomer having a nitrogen-containing heterocycle 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, N-vinylphthalimide, and the like, and among these, N- (meth) acryloylmorpholine exhibiting more excellent adhesion is preferable, and N-acryloylmorpholine is particularly preferable. These monomers having nitrogen-containing heterocycles may be used singly or in combination of two or more.

When the (meth) acrylic acid ester polymer (a) contains a nitrogen atom-containing monomer as a monomer unit constituting the polymer, the nitrogen atom-containing monomer is preferably contained in an amount of 1% by mass or more, particularly preferably 4% by mass or more, and further preferably 8% by mass or more. The (meth) acrylate polymer (a) preferably contains 20 mass% or less, particularly preferably 16 mass% or less, and further preferably 12 mass% or less of the nitrogen atom-containing monomer as a monomer unit constituting the polymer. When the content of the nitrogen atom-containing monomer is within the above range, the resulting adhesive can sufficiently exert excellent adhesion to glass.

The (meth) acrylate polymer (a) may contain other monomers as monomer units constituting the polymer, as desired. In order not to hinder the above-mentioned action of the reactive functional group-containing monomer, a monomer containing no reactive functional group is also preferable as the other monomer. Examples of the monomer 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.

The (meth) acrylate polymer (a) is preferably a linear polymer. Since the polymer is a linear polymer, the entanglement of molecular chains is likely to occur, and the cohesive force can be expected to be improved, the storage modulus, gel fraction, adhesive force, and the like of the obtained adhesive are likely to be appropriate, and the step following property under high-temperature and high-humidity conditions is excellent.

The (meth) acrylate polymer (a) is preferably a solution polymer obtained by a solution polymerization method. Since a polymer having a high molecular weight can be easily obtained by using a solution polymer, the cohesive force can be expected to be improved, and therefore the storage modulus, gel fraction, adhesive force, and the like of the obtained adhesive agent are easily suitable, and the step following property under high-temperature and high-humidity conditions is excellent.

The polymerization form of the (meth) acrylic acid ester polymer (a) may be a random copolymer or a block copolymer.

The lower limit value of the weight average molecular weight of the (meth) acrylic acid ester polymer (a) is preferably 20 ten thousand or more, particularly preferably 30 ten thousand or more, further preferably 40 ten thousand or more, and from the viewpoint of dispersibility of the colorant (C), more preferably 50 ten thousand or more, particularly preferably 70 ten thousand or more. When the lower limit of the weight average molecular weight of the (meth) acrylate polymer (a) is set to the above, the storage modulus, gel fraction, adhesive force, etc. of the obtained adhesive tend to be suitable, and the step following property under high temperature and high humidity conditions is more excellent. Further, since the dispersibility of the colorant (C) in the adhesive tends to be good, the obtained adhesive has good reproducibility and uniformity of the optical properties, and is easy to satisfy the above formula (IV) (and formula (V)), and exhibits excellent design properties and visibility.

The upper limit of the weight average molecular weight of the (meth) acrylic acid ester polymer (a) is preferably 200 ten thousand or less, particularly preferably 150 ten thousand or less, and further preferably 100 ten thousand or less. When the upper limit of the weight average molecular weight of the (meth) acrylate polymer (a) is set to the above, the storage modulus, gel fraction, adhesive force, and the like of the obtained adhesive tend to be suitable, and the initial step following property is more excellent. The weight average molecular weight in the present specification is a value in terms of standard polystyrene measured by Gel Permeation Chromatography (GPC).

In the adhesive composition P, the (meth) acrylate polymer (a) may be used singly or in combination of two or more.

(1-2) crosslinking agent (B)

The crosslinking agent (B) can crosslink the (meth) acrylate polymer (a) by heating the adhesive composition P, and a solid network structure can be formed well. This improves the cohesive force of the obtained adhesive, and the step following property under high-temperature and high-humidity conditions is excellent.

The crosslinking agent (B) may be a crosslinking agent that reacts with a reactive group of the (meth) acrylate polymer (a), and examples thereof include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, amine-based crosslinking agents, melamine-based crosslinking agents, aziridine-based crosslinking agents, hydrazine-based crosslinking agents, aldehyde-based crosslinking agents, oxazoline-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, and ammonium salt-based crosslinking agents. Among the above, when the reactive group of the (meth) acrylate polymer (a) is a hydroxyl group, an isocyanate-based crosslinking agent having excellent reactivity with the hydroxyl group is preferably used, and when the reactive group of the (meth) acrylate polymer (a) is a carboxyl group, an epoxy-based crosslinking agent having excellent reactivity with the carboxyl group is preferably used. The crosslinking agent (B) may be used alone or in combination of two or more.

The isocyanate-based crosslinking agent contains at least a polyisocyanate (polyisocyanate) compound. Examples of the polyisocyanate compound 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 the like, biuret and isocyanurate thereof, and adducts as reactants with low-molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil, and the like. Among them, from the viewpoint of reactivity with hydroxyl groups, trimethylolpropane-modified aromatic polyisocyanates are preferred, and trimethylolpropane-modified toluene diisocyanate and trimethylolpropane-modified xylylene diisocyanate are particularly preferred.

Examples of the epoxy-based crosslinking agent include 1, 3-bis (N, N-diglycidyl aminomethyl) cyclohexane, N' -tetraglycidyl-m-xylylenediamine, ethylene glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidyl aniline, and diglycidyl amine. Among them, 1, 3-bis (N, N-diglycidyl aminomethyl) cyclohexane is preferable from the viewpoint of reactivity with carboxyl groups.

The content of the crosslinking agent (B) in the adhesive composition P is preferably 0.01 part by mass or more, particularly preferably 0.05 part by mass or more, and further preferably 0.1 part by mass or more, relative to 100 parts by mass of the (meth) acrylate polymer (a). The content is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, particularly preferably 1 part by mass or less, and further preferably 0.4 part by mass or less. When the content of the crosslinking agent (B) is within the above range, the obtained adhesive exhibits a good cohesive force, and can easily satisfy a desired storage modulus, gel fraction, adhesive force, and the like, and is more excellent in level difference following property under high-temperature and high-humidity conditions.

(1-3) colorant (C)

The colorant (C) is the above colorant. The specific kind is the same as described above.

The content of the colorant (C) is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, particularly preferably 0.3 part by mass or more, and further preferably 0.6 part by mass or more, relative to 100 parts by mass of the (meth) acrylate polymer (a). 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, further preferably 1 part by mass or less, and most preferably 0.9 part by mass or less. When the content of the colorant (C) is within the above range, the resulting adhesive can easily satisfy the above optical properties, and can easily satisfy the above formula (IV) (and formula (V)), and exhibits excellent design properties and visibility.

(1-4) active energy ray-curable component (D)

It is presumed that, in the adhesive agent obtained by curing the adhesive agent obtained by crosslinking the adhesive composition P with active energy rays, the active energy ray-curable components (D) are polymerized with each other, and the polymerized active energy ray-curable components (D) are entangled with the crosslinked structure (three-dimensional network) of the (meth) acrylate polymer (a). The adhesive having a high-dimensional structure exhibits extremely excellent durability, and particularly has excellent step following properties under high-temperature and high-humidity conditions.

The active energy ray-curable component (D) is not particularly limited as long as it is a component that cures by irradiation with active energy rays and can obtain the above-described effects, and may be any of a monomer, an oligomer, or a polymer, or may be a mixture of these. Among them, polyfunctional acrylate monomers having more excellent foaming resistance can be preferably exemplified.

Examples of the polyfunctional acrylate monomer include difunctional acrylates such as 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 (acryloxyethyl) isocyanurate, allylated cyclohexyl di (meth) acrylate, ethoxylated bisphenol a diacrylate, 9-bis [4- (2-acryloxyethoxy) phenyl ] fluorene; trifunctional types 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, epsilon-caprolactone-modified tris (2- (meth) acryloyloxyethyl) isocyanurate, and the like; tetra-functionality such as diglycerol tetra (meth) acrylate and pentaerythritol tetra (meth) acrylate; five (methyl) acrylic ester of propionic acid modified dipentaerythritol, etc.; and hexafunctionality such as dipentaerythritol hexa (meth) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate. These polyfunctional acrylate monomers may be used singly or in combination of two or more. In addition, from the viewpoint of compatibility with the (meth) acrylate polymer (a), the molecular weight of the polyfunctional acrylate monomer is preferably less than 1000.

Among the above, from the viewpoint of the anti-foaming property of the obtained adhesive, a polyfunctional acrylate monomer having a cyclic structure (particularly a cycloalkane structure) in the molecule, such as di (acryloyloxyethyl) isocyanurate, tri (acryloyloxyethyl) isocyanurate, epsilon-caprolactone-modified tri (2- (meth) acryloyloxyethyl) isocyanurate or the like, or a polyfunctional acrylate monomer having a cyclic structure (particularly a cycloalkane structure) in the molecule, such as tricyclodecanedimethanol (meth) acrylate or the like, is preferable, a polyfunctional acrylate monomer having a trifunctional or higher and an isocyanurate structure in the molecule, or a polyfunctional acrylate monomer having a difunctional or higher and a polycyclic structure (particularly a cycloalkane polycyclic structure) in the molecule is more preferable, epsilon-caprolactone-modified tri (2- (meth) acryloyloxyethyl) isocyanurate or tricyclodecanedimethanol (meth) acrylate is more preferable, and epsilon-caprolactone-modified tri (2-acryloyloxyethyl) isocyanurate or tricyclodecanedimethanol acrylate is still more preferable, and epsilon-caprolactone-modified tri (2-acryloyloxyethyl) isocyanurate is most preferable.

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 further preferably 4 parts by mass or more, relative to 100 parts by mass of the (meth) acrylate polymer (a), in view of more excellent step-following property of the adhesive after the active energy ray curing under high-temperature and high-humidity conditions. On the other hand, the upper limit of the content is preferably 20 parts by mass or less, particularly preferably 12 parts by mass or less, and further preferably 8 parts by mass or less, from the viewpoint of the adhesive force of the adhesive after active energy ray curing.

(1-5) photopolymerization initiator (E)

When ultraviolet rays are used as active energy rays for curing the adhesive composition P, it is preferable that the adhesive composition P further contains a photopolymerization initiator (E). By containing the photopolymerization initiator (E) in this manner, the active energy ray-curable component (D) can be efficiently polymerized, and the polymerization curing time and the irradiation amount of active energy rays can be reduced.

Examples of such photopolymerization initiator (E) include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2-dimethoxy-2-phenylacetophenone, 2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1- [4- (methylthio) phenyl ] -2-morpholino-1-one, 4- (2-hydroxyethoxy) phenyl-2- (hydroxy-2-propyl) ketone, benzophenone, p-phenylbenzophenone, 4' -diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminothioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2, 4-dimethylthioxanthone, 2, 4-diethylthioxanthone, 2-dimethylketal, 2-dimethylthioketal, 2, 4-dimethylbenzoyl-2, 6-dimethylbenzoyl ketone, 2- (2-hydroxy-methylbenzoyl) ketone, 2, 6-dimethylbenzoyl-2- (2-hydroxy-2-propyl) ketone, and the like. These photopolymerization initiators may be used alone or in combination of two or more.

Among the above, phosphine oxide-based photopolymerization initiators are preferable, and even when irradiated with ultraviolet light through a plastic sheet containing an ultraviolet absorber, they are easily decomposed and the adhesive is easily cured with certainty. Specifically, 2,4, 6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2, 4, 6-trimethylbenzoyl) phenylphosphine oxide and the like are preferable.

The lower limit value of the content of the photopolymerization initiator (E) in the adhesive composition P is preferably 0.1 part 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.

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 further preferably 0.2 or more. The mass ratio is preferably 5 or less, particularly preferably 3 or less, and further preferably 1 or less. When the ratio of the amount of the photopolymerization initiator (E) to the amount of the colorant (C) is within the above range, the above optical properties can be easily satisfied, and an adhesive having suitable cohesive force or tackiness can be easily obtained by active energy ray curing, and the step following property under high-temperature and high-humidity conditions is more excellent.

(1-6) various additives

Various additives commonly used for acrylic adhesives, such as a silane coupling agent, a rust inhibitor, an ultraviolet absorber, an antistatic agent, a tackifier, an antioxidant, a light stabilizer, a softener, a refractive index regulator, and the like, may be added to the adhesive composition P as needed. In addition, a polymerization solvent or a dilution solvent described later is not included in the additives constituting the adhesive composition P.

Among the above, the adhesive composition P preferably contains a silane coupling agent. Thus, the adhesion to the adherend is improved regardless of whether the adherend is a plastic plate or a glass member, and the step following property under high-temperature and high-humidity conditions is more excellent.

As the silane coupling agent, an organosilicon compound having at least 1 alkoxysilyl group in a molecule, which has good compatibility with the (meth) acrylate polymer (a) and light transmittance, is preferable.

Examples of the silane coupling agent include silicon compounds containing a polymerizable unsaturated group such as vinyltrimethoxysilane, vinyltriethoxysilane, and methacryloxypropyl trimethoxysilane; silicon compounds having an epoxy structure such as 3-glycidoxypropyl trimethoxysilane and 2- (3, 4-epoxycyclohexyl) ethyl trimethoxysilane; mercapto group-containing silicon compounds such as 3-mercaptopropyl trimethoxysilane, 3-mercaptopropyl triethoxysilane, and 3-mercaptopropyl dimethoxymethylsilane; amino group-containing silicon compounds such as 3-aminopropyl trimethoxysilane, N- (2-aminoethyl) -3-aminopropyl trimethoxysilane and N- (2-aminoethyl) -3-aminopropyl methyldimethoxysilane; and condensation products of 3-chloropropyl trimethoxysilane, isocyanatopropyl triethoxysilane, or at least one of them with an alkyl group-containing silicon compound such as methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, etc. These silane coupling agents may be used singly or in combination of two or more.

The content of the silane coupling agent in the adhesive composition P is preferably 0.01 part by mass or more, particularly preferably 0.05 part by mass or more, and further preferably 0.1 part by mass or more, relative to 100 parts by mass of the (meth) acrylate polymer (a). The content is preferably 1 part by mass or less, particularly preferably 0.5 part by mass or less, and further preferably 0.3 part by mass or less. When the content of the silane coupling agent is within the above range, the obtained adhesive satisfies the above optical properties, and is easy to exhibit suitable cohesive force or adhesiveness, and is more excellent in step following property under high-temperature and high-humidity conditions.

(2) Preparation of adhesive composition

The adhesive composition P can be prepared by: the (meth) acrylate polymer (A) is prepared, and the obtained (meth) acrylate polymer (A), the crosslinking agent (B) and the colorant (C) are mixed, and the active energy ray-curable component (D), the photopolymerization initiator (E), the additive and the like are added as required.

The (meth) acrylate polymer (a) can be produced by polymerizing a mixture of monomers constituting the polymer by a usual radical polymerization method. The polymerization of the (meth) acrylic acid ester polymer (a) is preferably carried out by a solution polymerization method using a polymerization initiator as required. However, the present invention is not limited thereto, and polymerization may be performed without a solvent. Examples of the polymerization solvent include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, and methyl ethyl ketone, and two or more of them may be used simultaneously.

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

Dimethyl methylpropionate, 4' -azobis (4-cyanovaleric acid), 2' -azobis (2-hydroxymethylpropionitrile), 2' -azobis [2- (2-imidazolin-2-yl) propane ], and the like.

Examples of the organic peroxide include benzoyl peroxide, t-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di (2-ethoxyethyl) peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, 3, 5-trimethylhexanoyl peroxide, dipropyl peroxide, and diacetyl peroxide.

In the polymerization step, a chain transfer agent such as 2-mercaptoethanol is blended to adjust the weight average molecular weight of the polymer obtained.

After the (meth) acrylate polymer (a) is obtained, the crosslinking agent (B), the colorant (C), and the active energy ray-curable component (D), the photopolymerization initiator (E), the additive, and the like are added to the solution of the (meth) acrylate polymer (a), and the mixture is thoroughly mixed according to the required dilution solvent, active energy ray-curable component (D), photopolymerization initiator (E), additive, and the like, to obtain the solvent-diluted adhesive composition P (coating solution). In addition, in the case where a solid substance is used or in the case where precipitation occurs when the solid substance is mixed with other components in an undiluted state, the components may be dissolved or diluted in a diluting solvent in advance and then mixed with the other components.

As the diluent solvent, for example, aliphatic hydrocarbons such as hexane, heptane, cyclohexane, etc. can be used; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride 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 solvents such as ethyl cellosolve and the like.

The concentration and viscosity of the coating solution prepared in this way are not particularly limited as long as they are within a coatable range, and may be appropriately selected according to circumstances. For example, the adhesive composition P is diluted so that the concentration thereof is 10 to 60 mass%. In addition, the addition of a diluting solvent or the like is not a necessary condition in obtaining the coating solution, and the diluting solvent may not be added as long as the adhesive composition P has a viscosity or the like that enables coating. 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 a diluting solvent.

(3) Formation of colored adhesive layer

The colored adhesive layer 11 of the present embodiment is preferably composed of an adhesive formed by crosslinking (a coating layer of) the adhesive composition P. Crosslinking of the adhesive composition P can be generally performed by a heat treatment. In addition, the drying treatment when the diluting solvent or the like is volatilized from the coating layer of the adhesive composition P applied to the desired object may also be used as the heating treatment.

The heating temperature of the heating treatment is preferably 50 to 150 ℃, particularly preferably 70 to 120 ℃. The heating time is preferably 10 seconds to 10 minutes, and particularly preferably 50 seconds to 2 minutes.

After the heat treatment, a curing period of about 1 to 2 weeks may be set at normal temperature (e.g., 23 ℃ C., 50% RH) as needed. When the aging period is required, the adhesive is formed after the aging period, and when the aging period is not required, the adhesive is directly formed after the heating treatment is completed.

By the above heat treatment (and curing), the (meth) acrylate polymer (a) is sufficiently crosslinked via the crosslinking agent (B). The adhesive thus obtained is easy to satisfy a desired storage modulus, gel fraction, adhesive force, etc., and is excellent in step-following property under high-temperature and high-humidity conditions.

(4) Physical Properties of the adhesive

The adhesive of the present embodiment preferably has the following physical properties.

(4-1) gel fraction

The lower limit of the gel fraction in 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 set as described above, the cohesive force of the adhesive becomes high, and the step following property under high-temperature and high-humidity conditions is more excellent. The upper limit of the gel fraction of the adhesive according to 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 set as described above, the adhesive will not become excessively hard, and the initial step-following property and the step-following property under high-temperature and high-humidity conditions are excellent. In addition, the adhesive composition exhibits good adhesion and further excellent adhesion to an adherend.

The method for measuring the gel fraction of the adhesive is as shown in the test examples described below. When the adhesive is an active energy ray-curable adhesive, the gel fraction of the adhesive after active energy ray curing is set. In addition, in the case where the adhesive is an active energy ray-curable adhesive, the gel fraction of the adhesive before active energy ray curing is preferably 20 to 70%, particularly preferably 30 to 60%, and further preferably 40 to 55%, from the viewpoint of enabling the initial step-difference following property to be good.

(4-2) storage modulus

The lower limit of the storage modulus at 23℃of the adhesive according to the present embodiment is preferably 0.001MPa or more, more preferably 0.01MPa or more, particularly preferably 0.05MPa or more, and even more preferably 0.1MPa or more. By setting the lower limit value of the storage modulus to the above, the step following property under high temperature and high humidity conditions is excellent. 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 value of the storage modulus to the above, the initial step following property and the step following property under high-temperature and high-humidity conditions are excellent.

Here, the storage modulus in the present specification is a value measured by the torsional shear method (ね by the method せ by breaking) at a measurement frequency of 1Hz in accordance with JIS K7244-6. Specifically, as shown in test examples described below. When the adhesive is an active energy ray-curable adhesive, the storage modulus of the adhesive after active energy ray curing is set. In addition, in order to improve the initial step following property, 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 1MPa, particularly preferably 0.02 to 0.5MPa, and further preferably 0.04 to 0.1MPa.

(5) Thickness of colored adhesive layer

The lower limit value 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. If the lower limit of the thickness of the colored adhesive layer 11 is set to the above, the above 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 exhibited. The lower limit value 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 further preferably 80 μm or more, from the viewpoint of easily exhibiting excellent step-following property.

On the other hand, the upper limit value 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 the above, the workability is good, and the appearance defect due to the squeeze mark is less likely to occur. Further, the above formula (IV) (and formula (V)) is easily satisfied due to the relation with the content of the colorant (C). Further, 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, from the viewpoint of more easily satisfying the above formula (IV) (and formula (V)). The colored adhesive layer 11 may be formed of a single layer or may be formed by stacking a plurality of layers.

1-2 stripping sheet

The

release sheets

12a, 12b protect the colored adhesive layer 11 until the colored adhesive sheet 1 is used, which is peeled off when the colored adhesive sheet 1 (colored adhesive layer 11) is used. In the colored adhesive sheet 1 of the present embodiment, one or both of the

release sheets

12a, 12b are not necessary.

Examples of the

release sheets

12a and 12b include polyethylene films, polypropylene films, polybutylene films, polybutadiene films, polymethylpentene films, polyvinyl chloride films, vinyl chloride copolymer films, polyethylene terephthalate films, polyethylene naphthalate films, polybutylene terephthalate films, polyurethane films, ethylene-vinyl acetate films, ionomer resin films, ethylene- (meth) acrylic acid copolymer films, ethylene- (meth) acrylic acid ester copolymer films, polystyrene films, polycarbonate films, polyimide films, and fluororesin films. In addition, crosslinked films of these films may also be used. Further, these films may be laminated films.

The release surfaces (particularly, the surfaces in contact with the colored adhesive layer 11) of the

release sheets

12a and 12b are preferably subjected to a release treatment. Examples of the release agent used for the release treatment include release agents such as alkyd, silicone, fluorine, unsaturated polyester, polyolefin, and wax. In addition, among the

release sheets

12a and 12b, one release sheet is preferably a heavy release type release sheet having a large release force, and the other release sheet is preferably a light release type release sheet having a small release force.

The thickness of the

release sheets

12a, 12b is not particularly limited, but is usually about 20 to 150 μm.

2. Physical properties (adhesive force)

The lower limit value of the adhesion of the colored adhesive sheet 1 of the present embodiment to 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 the above, the step following property under high-temperature and high-humidity conditions is more excellent. The upper limit of the adhesion of the colored adhesive sheet 1 of the present embodiment to 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 force is the above, good reworkability can be obtained, and when a bonding error occurs, the display constituent member, particularly the expensive display constituent member, can be reused.

The adhesion in the present specification is a value obtained by making a measurement sample 25mm wide and 100mm long according to the 180 degree peel method of JIS Z0237:2009, attaching the measurement sample to an adherend, pressurizing at 0.5MPa and 50℃for 20 minutes, standing at normal pressure and 23℃and 50% RH for 24 hours, and measuring at a peel speed of 300 mm/min. When the adhesive is an active energy ray-curable adhesive, the adhesive is an adhesive force of a colored adhesive layer which is applied to an adherend and cured by active energy rays. In addition, in terms of adhesion to an adherend and reworkability, when the adhesive is an active energy ray-curable adhesive, the adhesive force of the adhesive before active energy ray curing is preferably 1 to 80N/25mm, particularly preferably 2 to 50N/25mm, and further preferably 4 to 30N/25mm.

3. Production of colored adhesive sheet

As one example of production of the colored adhesive sheet 1, a coating solution of the adhesive composition P is applied to the release surface of one release sheet 12a (or 12 b), the adhesive composition P is thermally crosslinked by heat treatment to form a coating layer, and the coating layer is laminated on the release surface of the other release sheet 12b (or 12 a). When the curing period is required, the adhesive layer 11 is colored by providing the curing period, and when the curing period is not required, the adhesive layer 11 is directly formed by the coating layer. Thus, the colored adhesive sheet 1 can be obtained. The conditions for heat treatment and curing are as described above.

As another example of production of the colored adhesive sheet 1, a coating solution of the adhesive composition P is applied to the release surface of one release sheet 12a, and the adhesive composition P is thermally crosslinked by heat treatment to form a coating layer, thereby obtaining a release sheet 12a with a coating layer. The coating solution of the adhesive composition P is applied to the release surface of the other release sheet 12b, and the adhesive composition P is thermally crosslinked by heat treatment to form a coating layer, thereby obtaining the release sheet 12b with a coating layer. Then, the coated release sheet 12a and the coated release sheet 12b are bonded so that the two coated layers are in contact with each other. Here, a plurality of release sheets with coating layers may be manufactured and a desired number of the coating layers may be attached. When the curing period is required, the cured period is set, and the laminated coating layer is the colored adhesive layer 11, and when the curing period is not required, the laminated coating layer is directly 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 is possible.

As a method of applying the coating solution of the adhesive composition P, for example, a bar coating method, a doctor blade coating method, a roll coating method, a doctor blade coating method, a die coating method, a gravure coating method, or the like can be used.

[ display body ]

The display according to one embodiment of the present invention includes a first display constituent member having at least two regions of different brightness in a planar direction, a second display constituent member, and a colored adhesive layer that bonds the first display constituent member and the second display constituent member to each other. In the display of the present embodiment, when L1 is the brightness L of one region R1, L2 is the brightness L of the other region R2, L1 'is the brightness L of the region R1 in which the colored adhesive layer is laminated, and L2' is the brightness L of the region R2 in which the colored adhesive layer is laminated, defined by the CIE1976l×a×b.

ΔL＝L1-L2 ···(I)

ΔL’＝L1’-L2’ ···(II)

ΔL＞0 ···(III)

(ΔL’/ΔL)×100≤80 ···(IV)

Examples of the type of display (display) in the present embodiment include a vehicle-mounted display provided in a dashboard of an automobile, a car navigation system, various instruments of a console, a display of a tablet terminal or the like used by a general user, a display of a tablet terminal or the like for business use, a display of a digital signage or the like, and a display of a digital signage or the like for outdoor use. These displays are sometimes required to have an appearance compatibility with surrounding members, a sense of high-quality, and the like. However, the display body of the present invention is not limited thereto.

Fig. 2 shows a specific configuration of an example of the display body according to the present embodiment.

As shown in fig. 2, the display 2 of the present embodiment is configured by including a first display component member 21 (one display component member), a second display component member 22 (the other display component member), and a colored adhesive layer 11, wherein the colored adhesive layer 11 is located between the first display component member 21 and the second display component member 22, and the first display component member 21 and the second display component member 22 are bonded to each other.

At least one of the first display element-constituting member 21 and the second display element-constituting member 22 may have a step at least on the surface on the side to which the colored adhesive layer 11 is attached. In the present embodiment shown in fig. 2, the first display element constituting member 21 has a level difference of the printed layer 3 or the like on the surface on the colored adhesive layer 11 side. The first display element constituting member 21 in this case has at least two regions having different brightness in the planar direction between the region passing through the printed layer 3 and the other regions.

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 physical properties are satisfied.

Examples of the display body 2 include a Liquid Crystal (LCD) display, a Light Emitting Diode (LED) display, an organic electroluminescence (organic EL) display, and electronic paper, and may be a touch panel.

The first display element constituting member 21 is preferably a protective panel made of a laminate including a glass plate, a plastic plate, or the like, in addition to the glass plate, the plastic plate, or the like. At this time, the printed layer 3 is generally formed in a frame shape on the colored adhesive layer 11 side of the first display element configuration member 21.

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 usually 0.1 to 5mm, preferably 0.2 to 2mm.

The plastic sheet is not particularly limited, and examples thereof include an acryl sheet and a polycarbonate sheet. The thickness of the plastic plate is not particularly limited, but is usually 0.2 to 5mm, preferably 0.4 to 3mm.

Various functional layers (transparent conductive film, metal layer, silica layer, hard coat layer, antiglare layer, etc.) may be provided on one or both surfaces of the glass plate or plastic plate, or an optical member may be laminated. In addition, the transparent conductive film and the metal layer may also be patterned.

The second display constituent member 22 is preferably an optical member to be attached to the first display constituent member 21, a display module (for example, a Liquid Crystal (LCD) module, a Light Emitting Diode (LED) module, an organic electroluminescence (organic EL) module, or the like), an optical member that is a part of the display module, or a laminate including the display module.

Examples of the optical member include a scattering preventing film, a polarizing plate (polarizing film), a polarizing plate, a retardation plate (retardation film), a viewing angle compensating film, a brightness enhancing film, a contrast enhancing film, a liquid crystal polymer film, a diffusion film, a semi-transmissive reflective film, and a transparent conductive film. Examples of the scattering preventing film include a hard coat film in which a hard coat layer is formed on one surface of a base film.

The material constituting the printing layer 3 is not particularly limited, and a known material for printing can be used.

The lower limit value of the thickness of the printed layer 3, i.e., the height of the step is preferably 3 μm or more, more preferably 5 μm or more, particularly preferably 7 μm or more, and most preferably 10 μm or more. By setting the lower limit value to be equal to or more than the above, it is possible to sufficiently ensure the hiding of the electric wiring or the like from the observer side. The upper limit is preferably 50 μm or less, more preferably 35 μm or less, particularly preferably 25 μm or less, and further preferably 20 μm or less. By setting the upper limit value to the above-described range, deterioration in level difference follow-up property of the colored adhesive layer 11 with respect to the printed layer 3 can be prevented.

The printed layer 3 is preferably black. The lightness L, chromaticity a, and chromaticity b of the printed layer 3, which are defined by the CIE1976L x a x b x color system, are the same as the preferable ranges of the hues of the surrounding members. However, the color tone is generally different from that of an instrument panel, a frame material of a display body, or the like of an automobile.

In order to manufacture the display 2, as an example, one release sheet 12a of the colored adhesive sheet 1 is released, and the colored adhesive layer 11 exposed in the colored adhesive sheet 1 is bonded to the surface of the first display component member 21 on the side where the print layer 3 is present.

Then, the other release sheet 12b is peeled off from the colored adhesive layer 11 of the colored adhesive sheet 1, and the colored adhesive layer 11 exposed in the colored adhesive sheet 1 and the second display element constituting member 22 are bonded. As another example, the order of bonding the first display element forming member 21 and the second display element forming member 22 may be changed.

When the colored adhesive layer 11 is active energy ray curable, the first display element constituent member 21 and the second display element constituent member 22 are bonded via the colored adhesive layer 11 as described above, and then active energy rays are irradiated to the colored adhesive layer 11. Thereby, the energy ray curable component (C) in the colored adhesive layer 11 is polymerized, and the colored adhesive layer 11 is cured. The irradiation of the colored adhesive layer 11 with energy rays is usually performed through either the first display element constituting member 21 or the second display element constituting member 22, and is preferably performed through the first display element constituting member 21 as a protective panel.

The active energy ray is an active energy ray having an energy quantum in an electromagnetic wave or a charged particle beam, and specifically includes ultraviolet rays, electron beams, and the like. Among active energy rays, ultraviolet rays which are easy to handle are particularly preferable.

The irradiation of ultraviolet rays can be performed by using a high-pressure mercury lamp, fusion H lamp, xenon lamp, etc., and the irradiation amount of ultraviolet rays is preferably 50 to 1000mW/cm by an illuminometer ² About, preferably 100 to 500mW/cm ² Left and right. Further, the light quantity is preferably 50 to 10000mJ/cm ² More preferably 200 to 7000mJ/cm ² Particularly preferably 500 to 3000mJ/cm ² . On the other hand, the electron beam irradiation may be performed using an electron beam accelerator or the like, and the irradiation amount of the electron beam is preferably about 10 to 1000 krad.

Here, as shown in fig. 3, the display body 2 (first display body constituting member 21) of the present embodiment preferably has a frame material 4 around the display body 2 (first display body constituting member 21). At this time, the first display element forming member 21 is a display element forming member having at least two regions having different brightness in the planar direction between the region passing through the frame material 4 and the other regions. The region of the print layer 3 and the other region may be regions having at least two different brightness values in the planar direction, with respect to the region other than the frame material 4 (the region inside the frame material 4).

Preferably, the frame material 4 is black. The preferred ranges of the hue of the frame material 4, i.e., the lightness L, the chromaticity a, and the chromaticity b defined by the CIE1976l×a×b color system, are the same as the hue of the surrounding members. By providing the frame material 4 with this color tone, it is easy to be recognized by the naked human eye as a frame material having a visually high-quality feel. Further, by providing the frame material 4 with the color tone, the colored adhesive layer 11 of the present embodiment has an enhanced overall feel with the frame material 4, and has a more excellent appearance compatibility.

By the physical properties of the colored adhesive layer 11, the designability of the display body 2 when the lamp is turned off is improved. For example, when the display body 2 is turned off, the boundary with the black frame material 4 is not easily distinguished (seamless), and excellent external appearance compatibility can be exhibited. In addition, when a black printed layer is present inside the frame material 4 of the display body 2, the boundary between the printed layer and the display portion of the display body 2 and the boundary between the printed layer and the frame material 4 are not easily distinguished even when the display body 2 is turned off.

Further, in the display body 2, when the colored adhesive layer 11 is formed of the adhesive composition P, the colored adhesive layer 11 is excellent in step following property under high temperature and high humidity conditions, and thus, for example, even when the display body 2 is placed under high temperature and high humidity conditions (for example, 85 ℃ and 85% rh), occurrence of floating, peeling, and the like in the vicinity of the step can be suppressed.

The level difference following performance may be determined using the level difference following rate (%) as an index. The lower limit value of the step following ratio (%) of the colored adhesive layer 11 represented by the following formula is preferably 10% or more, more preferably 20% or more, particularly preferably 40% or more, further preferably 50% or more, and most preferably 60% or more. The upper limit of the step following ratio is not particularly limited, but is usually preferably 80% or less, and particularly preferably 70% or less.

Step following ratio (%) = [ (step height (μm) at which no bubbles, floating, peeling, or the like remain embedded after a predetermined endurance test))/(thickness of colored adhesive layer) ] ×100

The method of testing the step following rate is as shown in the test example described below.

The embodiments described above are described for easy understanding of the present invention, and are not described for limiting the present invention. Accordingly, each element disclosed in the above embodiments also covers all design changes and equivalents falling within the technical scope of the present invention.

For example, either one or both of the

release sheets

12a, 12b in the colored adhesive sheet 1 may be omitted, and further, a desired optical member may be laminated instead of the release sheet 12a and/or 12b. Further, the first display body constituting member 21 may not have a step. Further, not only the first display element constituting member 21 but also the second display element constituting member 22 may have a step on the colored adhesive layer 11 side.

Examples

The present invention will be further specifically described with reference to examples, but the scope of the present invention is not limited to these examples.

Example 1

1. Preparation of (meth) acrylate polymers

The (meth) acrylate polymer (a) was prepared by copolymerizing 70 parts by mass of 2-ethylhexyl acrylate, 15 parts by mass of methyl methacrylate, and 15 parts by mass of 2-hydroxyethyl acrylate by a solution polymerization method. The molecular weight of the (meth) acrylate polymer (a) was measured by the method described later, and as a result, the weight average molecular weight (Mw) was 80 ten thousand.

2. Preparation of adhesive composition

100 parts by mass (solid content equivalent; the same applies hereinafter) of the (meth) acrylic ester polymer (A) obtained in the above-mentioned step 1, 0.2 part by mass of trimethylolpropane-modified toluene diisocyanate (TOYOCHEM CO., LTD. Manufactured by LTD. Product name "BHS 8515"), 0.4 part by mass of carbon black-based black pigment (C1) as a colorant (C), and 0.2 part by mass of 3-glycidoxypropyl trimethoxysilane as a silane coupling agent were mixed, sufficiently stirred, and diluted with methyl ethyl ketone, thereby obtaining a coating solution of the adhesive composition.

In table 1, the proportions (solid content conversion values) of the adhesive composition are shown when the (meth) acrylate polymer (a) is 100 parts by mass (solid content conversion values). The abbreviations shown in table 1 are as follows.

[ (meth) acrylate Polymer (A) ]

2EHA: 2-ethylhexyl acrylate

MMA: methyl methacrylate

HEA: acrylic acid 2-hydroxy ethyl ester

IBXA: isobornyl acrylate

ACMO: n-acryloylmorpholine

BA: acrylic acid n-butyl ester

AA: acrylic acid

[ colorant (C) ]

C1-C5: carbon black-based black pigment having physical properties shown in Table 2

3. Production of colored adhesive sheet

The coating solution of the adhesive composition obtained in the above step 2 was applied to a release treated surface of a re-release type release sheet (manufactured by Lintec Corporation, product name "SP-PET 752150") in which one side of a polyethylene terephthalate film was release-treated with a silicone-based release agent using a blade coater, and then heat-treated at 90 ℃ for 1 minute to form a coating layer (thickness: 50 μm). The coating solution of the adhesive composition obtained in the step 2 was applied onto a release treated surface of a light release sheet (manufactured by Lintec Corporation, product name "SP-PET 381130") obtained by releasing a polyethylene terephthalate film on one surface thereof with a silicone release agent, using a blade coater, and then heat-treated at 90 ℃ for 1 minute to form a coating layer (thickness: 50 μm).

Then, the re-release sheet with a coated layer obtained above and the light release sheet with a coated layer obtained above were bonded so that the two coated layers were in contact with each other, and cured at 23℃for 7 days under 50% RH to prepare a colored adhesive sheet composed of a composition of a re-release sheet/colored adhesive layer (thickness: 100 μm)/light release sheet.

The thickness of the colored adhesive layer was measured according to JIS K7130 using a constant pressure thickness measuring device (TECLOCK CO., LTD. Manufactured by LTD. Product name "PG-02").

Examples 2 to 8 and comparative example 1

A colored adhesive sheet was produced in the same manner as in example 1, except that the types and proportions of the monomers constituting the (meth) acrylic polymer (a), the weight average molecular weight (Mw) of the (meth) acrylic polymer (a), the types and amounts of the colorants (C), the amounts of the silane coupling agent, and the thicknesses of the colored adhesive layers were changed as shown in table 1. To example 5, 5.0 parts by mass of epsilon-caprolactone-modified tris (2-acryloyloxyethyl) isocyanurate (SHIN-nakamurachei co., ltd. Manufactured under the product name "NKester a-9300-1 CL") 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. In comparative example 1, the coloring agent (C) was not used, but for convenience, the terms colored adhesive layer and colored adhesive sheet were used.

The colored adhesive sheets of examples 2 to 8 and comparative example 1 were produced in the following manner. A coating solution of the adhesive composition prepared in the same manner as in example 1 was applied to a release treated surface of a heavy release sheet (manufactured by Lintec Corporation, product name "SP-PET 752150") in which one side of a polyethylene terephthalate film was subjected to release treatment using a silicone-based release agent using a blade coater, and then heat-treated at 90 ℃ for 1 minute to form a coating layer. The surface of the obtained heavy release sheet with a coating layer on the coating layer side was bonded to a release treated surface of a light release sheet (manufactured by Lintec Corporation under the product name "SP-PET 381130") obtained by releasing one side of a polyethylene terephthalate film with a silicone release agent, and cured under the conditions of 23 ℃ and 50% rh for 7 days, whereby a colored adhesive sheet composed of a composition of a heavy release sheet/colored adhesive layer/light release sheet was produced.

The weight average molecular weight (Mw) is a polystyrene-equivalent weight average molecular weight measured by Gel Permeation Chromatography (GPC) under the following conditions (GPC measurement).

< measurement conditions >

GPC measurement apparatus: TOSOH CORPORATION, HLC-8020

GPC column (passing in the following order): TOSOH CORPORATION manufacture TSK guard column HXL-H

TSK gel GMHXL(×2)

TSK gel G2000HXL

Measuring solvent: tetrahydrofuran (THF)

Measurement temperature: 40 DEG C

Test example 1 (determination of haze value of colorant diluent)

The haze value (%) of a solution obtained by diluting a colorant of C1 to C5 with ethyl acetate by 1 ten thousand times was measured by using a haze meter (NIPPON DENSHOKU INDUSTRIES Co., LTD., product name "SH-7000", optical path length 10 mm) according to JIS K7136:2000. From this measurement value, the difference between the haze value at the wavelength of 780nm and the haze value at the wavelength of 380nm, the average haze, which is the average of the haze value at the wavelength of 780nm and the haze value at the wavelength of 380nm, and the standard deviation of the haze values at the respective wavelengths at the 5nm pitches of the wavelength regions of 380nm to 780nm were calculated. These results are shown in table 2.

[ test example 2] (determination of gel fraction)

The colored adhesive sheets obtained in examples and comparative examples were cut into 80mm×80mm sizes, and the colored adhesive layers were wrapped in a polyester net (mesh size 200), and the mass was measured using a precision balance, and the mass of the adhesive itself was calculated by subtracting the individual mass of the net. The mass at this time was designated as M1.

Then, the adhesive coated in the polyester net was immersed in ethyl acetate at room temperature (23 ℃) for 24 hours. Then, the adhesive was taken out, air-dried at a temperature of 23℃and a relative humidity of 50% for 24 hours, and further dried in an oven at 80℃for 12 hours. After drying, the mass was weighed with a precision balance, and the mass of the adhesive itself was calculated by subtracting the individual mass of the above net. The mass at this time was designated as M2. The gel fraction (%) was represented by (M2/M1). Times.100. The results are shown in Table 3.

Further, with respect to the colored adhesive sheet of example 5, a plastic sheet (manufactured by MITSUBISHI GAS CHEMICAL COMPANY, inc. Product name "iupilon-sheet MR58U", thickness: 0.7mm, including an ultraviolet absorber) having a polymethyl methacrylate resin (PMMA) layer laminated on a polycarbonate resin (PC) sheet was laminated on a light release sheet, and the colored adhesive layer was cured by irradiation of an active energy ray through the plastic sheet under the following conditions. The gel fraction (after UV) was also derived for the adhesive of the cured colored adhesive layer in the same manner as described above.

< conditions for irradiation with active energy rays >

Using high-pressure mercury lamps

Illuminance 200mW/cm ² Light quantity 2000mJ/cm ²

UV illuminance/light meter "UVPF-A1" manufactured by Eye graphics co., ltd.

Test example 3 (determination of storage modulus)

The release sheets were peeled from the colored adhesive sheets obtained in examples and comparative examples, and a plurality of colored adhesive layers were laminated so that the thickness became 3 mm. From the resulting laminate of colored adhesive layers, a cylinder (height 3 mm) having a diameter of 8mm was punched out, and this was taken as a sample.

For the above samples, storage modulus (MPa) was measured by a torsional shear method using a viscoelasticity measuring apparatus (product name "MCR300" manufactured by Physica Co., ltd.) in accordance with JIS K7244-6 under the following conditions. The results are shown in Table 3.

Measuring frequency: 1Hz

Measuring temperature: 23 DEG C

The colored adhesive sheet of example 5 was irradiated with active energy rays in the same manner as in test example 2, and the colored adhesive layer was cured, and the storage modulus (after UV) of the cured colored adhesive layer was also measured in the manner described above.

[ test example 4] (measurement of haze value)

The colored adhesive layers of the colored adhesive sheets obtained in examples and comparative examples were measured for haze value (%) according to JIS K7136:2000 using a haze meter (NIPPON DENSHOKU INDUSTRIES Co., LTD., product name "SH-7000"). The total light haze value (%) obtained is shown in table 3. Further, the average haze, which is an average of the haze value at the wavelength of 780nm and the haze value at the wavelength of 380nm, the difference between the haze value at the wavelength of 780nm and the haze value at the wavelength of 380nm, and the standard deviation of the haze value at each wavelength of 5nm pitch in the wavelength region of 380nm to 780nm were calculated from the measured values. The results are shown in Table 3.

The colored adhesive sheet of example 5 was irradiated with active energy rays in the same manner as in test example 2, and the colored adhesive layer was cured, and the total light haze value (after UV) of the cured colored adhesive layer was measured in the manner described above. Then, the average haze (after UV), which is an average of the haze value at 780nm and the haze value at 380nm, the difference (after UV) between the haze value at 780nm and the haze value at 380nm, and the standard deviation (after UV) of the haze value at each wavelength of the 5nm pitch in the wavelength region 380nm to 780nm were calculated from the measured values. The results are shown in Table 3.

Test example 5 (measurement of total light transmittance)

The colored adhesive layers of the colored adhesive sheets obtained in examples and comparative examples were bonded to glass, and the resulting sheets were used as measurement samples. The total light transmittance (%) of the above measurement sample was measured by using a haze meter (NIPPON DENSHOKU INDUSTRIES Co., LTD. Manufactured by LTD. Product name "SH-7000") according to JIS K7361-1:1997, based on the background measurement (background measurement) performed using glass. The colored adhesive sheet of example 5 was irradiated with active energy rays in the same manner as in test example 2, and the colored adhesive layer was cured, and the total light transmittance (after UV) of the cured colored adhesive layer was measured in the manner described above. The results are shown in Table 3.

Test example 6 (measurement of colored adhesive layer L a b)

The colored adhesive layers of the colored adhesive sheets obtained in examples and comparative examples were measured for lightness L, chroma a, and chroma b defined by the CIE1976L x b x color system using a simultaneous photometer spectrocolorimeter (NIPPON DENSHOKU INDUSTRIES co., ltd. Manufactured under the product name "SQ 2000"). Further, the colored adhesive sheet of example 5 was irradiated with active energy rays in the same manner as in test example 2, and the colored adhesive layer was cured, and brightness L (after UV), chromaticity a (after UV) and chromaticity b (after UV) were measured for the cured colored adhesive layer in the manner described above. The results are shown in Table 3.

Test example 7 (measurement of adhesion)

The light release type release sheet was peeled off from the colored adhesive sheets obtained in examples and comparative examples, and the exposed colored adhesive layer was bonded to an easy-to-adhere layer of a polyethylene terephthalate (PET) film (TOYOBO co., ltd. Manufactured by the product name "PET a4300", thickness: 100 μm) having an easy-to-adhere layer, to obtain a laminate of release sheet/colored adhesive layer/PET film. The obtained laminate was cut into a sheet having a width of 25mm and a length of 100mm, and the sheet was used as a sample.

The heavy release type release sheet was peeled off from the above sample at 23 ℃ under 50% rh, and the exposed colored adhesive layer was attached to soda lime glass (Nippon Sheet Glass co., ltd.) and then pressurized at 50 ℃ for 20 minutes using an autoclave manufactured by kurarasaeisakusho co., ltd.). After the film was left to stand at 23℃for 24 hours at 50% RH, the film was subjected to a tensile testing machine (manufactured by ORIENTEC CORPORATION under the product name "TENSILON") to measure the adhesive force (N/25 mm) at a peeling speed of 300 mm/min and a peeling angle of 180 degrees. The conditions not described herein were measured according to JIS Z0237:2009. The results are shown in Table 3.

In addition, the colored adhesive sheet of example 5 was attached to soda lime glass in the same manner as described above, and after the autoclave treatment, the sheet was left to stand at 23℃and 50% RH for 24 hours, and then the colored adhesive sheet was cured by irradiation with active energy rays in the same manner as in test example 2, and the adhesive force (after UV) was also measured for the cured colored adhesive sheet in the same manner as described above.

Test example 8 (measurement of step following Rate)

On the surface of a glass plate (NSG Precision Cells, inc. Manufactured, product name "corning glass eagle XG", length 90mm×width 50mm×thickness 0.5 mm), an ultraviolet curable ink (Teikoku Printing Inks mfg.co., manufactured by Ltd, product name "POS-911 ink") was screen-printed in a frame shape (outline: length 90mm×width 50mm, width 5 mm). Then, ultraviolet rays (80W/cm) ² 2 metal halogen lamps, lamp height 15cm, belt speed 10-15 m/min) were used to cure the printed ultraviolet curable ink, and a printed ink having a level difference (level difference height: any one of heights 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 50 μm, 60 μm and 70 μm).

The light release type release sheet was peeled off from the colored adhesive sheets obtained in examples and comparative examples, and the exposed colored adhesive layer was bonded to an easy-to-adhere layer of a polyethylene terephthalate film (TOYOBO co., ltd. Manufactured by the product name "PET a4300", thickness: 100 μm) having an easy-to-adhere layer. Then, the heavy release type release sheet was peeled off to expose the colored adhesive layer. Then, the laminate was laminated on each glass plate with a step so that the colored adhesive layer covered the entire frame-like printing surface using a laminator (manufactured by fujiplanc, product name "LPD 3214"), and was used as a sample for evaluation.

The obtained sample for evaluation was subjected to autoclave treatment at 50℃and 0.5MPa for 30 minutes, and then left at 23℃and 50% RH for 24 hours. Next, the composition was stored at 85℃under high temperature and high humidity conditions of 85% RH for 72 hours (endurance test), and then the level difference following property was evaluated. The level difference following property is determined by whether or not the printed level difference is completely embedded in the colored adhesive layer, and the case where bubbles, floating, peeling, and the like are observed at the interface between the printed level difference and the colored adhesive layer is determined as failing to follow the printed level difference. Here, the step following property was evaluated by a step following rate (%) shown by the following formula. The results are shown in Table 3.

Step following ratio (%) = [ (step height (μm) at which no bubbles, floating, peeling, or the like remain embedded after the endurance test))/(thickness of colored adhesive layer) ]×100

Further, a colored adhesive sheet having a thickness of 25 μm was prepared as the colored adhesive sheet of example 5, and the colored adhesive sheet was cured by subjecting the sample for evaluation obtained in the same manner as described above to autoclave treatment, then, by irradiation with active energy rays in the same manner as in test example 2 after being left for 24 hours under the conditions of 23 ℃ and 50% rh. The step following property (after UV) of the cured colored adhesive layer was measured in the same manner as described above.

Test example 9 (measurement and calculation of lightness L)

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 background on one side of paper (length 100mm x width 100 mm) to obtain three black substrates (black substrates having black background a to C). The hues of the black backgrounds a to C (specified by CIE1976L a b in the color system) of the black substrates were measured by using a spectrophotometer (manufactured by BYK corporation under the product name "Spectro-Guide"), respectively (reflected light from the incident light on the black background side). Let L be the brightness of black background a _A Let L be the brightness of black background B _B Let L be the brightness of black background C _C The measured values are shown in Table 4.

On the other hand, the colored adhesive sheets obtained in examples and comparative examples were cut into pieces having a length of 70mm

X 70mm wide, and the colored adhesive layer of the colored adhesive sheet was bonded so as to be sandwiched between two sheets of soda lime glass (Nippon Sheet Glass co., ltd., manufactured by ltd., length 70mm x width 70mm x thickness 1.1 mm), and this was used as a sample. The colored adhesive sheet of example 5 was irradiated with active energy rays in the same manner as in test example 2, and the colored adhesive layer was cured to obtain a sample.

The obtained samples were laminated on the above three black substrates, and the respective brightness L (reflected light from the incident light on the sample side) was measured using a spectrophotometer (manufactured by BYK corporation under the product name "Spectro-Guide"). Black color laminated with colored adhesive layerBrightness L of background A is equal to L _A ' brightness L of black background B laminated with colored adhesive layer is represented by L _B ' brightness L of black background C with colored adhesive layer laminated thereon is represented by L _C ' representation. The results are shown in Table 4.

From the measurement results, the following values were calculated. The results are shown in Table 4.

·ΔL _AC ＝L _A -L _C

·ΔL _AC ’＝L _A ’-L _C ’

·(ΔL _AC ’/ΔL _AC )×100

·ΔL _AB ＝L _A -L _B

·ΔL _AB ’＝L _A ’-L _B ’

·(ΔL _AB ’/ΔL _AB )×100

·ΔL _BC ＝L _B -L _C

·ΔL _BC ’＝L _B ’-L _C ’

·(ΔL _BC ’/ΔL _BC )×100

Test example 10 (evaluation of designability)

The following three boundary portions were formed using black substrates having black-based backgrounds a to C obtained in the same manner as in test example 9.

Boundary portion (a/C): the black base material having the black background C is superimposed and arranged on the black base material having the black background A in a staggered state, so that a boundary portion (A/C) between the black background A and the black background C is formed.

Boundary portion (a/B): a black substrate having a black background B is superimposed and arranged on a black substrate having a black background A in a staggered state to form a boundary portion (A/B) between the black background A and the black background B.

Boundary portion (B/C): the black substrates having the black background C are superimposed and arranged in a staggered state on the black substrates having the black background B, so that the boundary portions (B/C) between the black background B and the black background C are formed.

Next, samples prepared in the same manner as in test example 9 were placed on black-based backgrounds including boundary portions. The visual appearance (see-and-turn) of the boundary portions (whether the boundary portions are conspicuous or not, and whether the black-based backgrounds are fused or not) was determined by the naked eye under a three-wavelength fluorescent lamp (distance from the fluorescent lamp: 200 cm), and the design properties concerning the seamless joining was evaluated by the following criteria.

The results are shown in Table 4.

And (3) the following materials: the boundary portion is hardly noticeable, and the respective black backgrounds are fused with each other.

O: the boundary portion can be distinguished by the privacy, but this is not a problem, and the black backgrounds are fused with each other.

X: the boundary portion is conspicuous, and the respective black backgrounds do not merge with each other.

Test example 11 (evaluation of character visibility)

In a 15.6 inch size display (manufactured by Fujitsu Limited, product name "LITEBOOK a 574/H") with resolution 1366 x 768, black background, white text (numbers, fonts: MS PGothic) was displayed at a size of 5 pounds (point) to 20 pounds (increased at 1 pound intervals) of 100%.

A sample prepared in the same manner as in test example 9 was placed on the display. Then, at a position 100cm away from the display, the size of the recognizable text was confirmed by naked eyes, and the text visibility was evaluated by the following criteria. The results are shown in Table 4.

And (3) the following materials: 8 lbs. of text can be recognized without any problem.

O: 8 lbs. of text was not completely recognized, but 10 lbs. of text was recognized without any problem.

X: failing to recognize 10 lbs of text.

Test example 12 (evaluation of Wide-angle visibility)

The sample prepared in the same manner as in test example 9 was set directly in front of a display (manufactured by Fujitsu Limited, product name "LITEBOOK a574/H", size 15.6 inches, resolution 1366×768) in a lit state. At this time, an ARIB multi-format color bar (Multiformat color bar) is displayed on the display. Then, under a three-wavelength fluorescent lamp (distance from the fluorescent lamp: 200 cm), the visual appearance of the display with the sample interposed therebetween was visually judged from the front and the inclined plane (angle of 45 °) with respect to the sample, and the visibility (wide-angle visibility) was evaluated according to the following criteria. The results are shown in Table 4.

And (3) the following materials: the visual appearance observed from the front is not different from that observed from the inclined plane.

O: the visual appearance observed by the chamfer was darkened, but the hue was unchanged, compared to the visual appearance observed by the front face.

X: the visual appearance observed from the front changes in hue from the visual appearance observed from the oblique plane.

In addition, in all examples, the screen is bright when viewed from the front, and therefore the visibility of the image depending on the screen brightness is good.

TABLE 1

TABLE 2

As is clear from the above table, the display using the colored adhesive sheet obtained in the examples is excellent in design properties, particularly in design properties concerning seamless formation. In addition, the display using the colored adhesive sheets obtained in examples 1 to 7 was also excellent in visibility. Further, the colored adhesive sheet obtained in the examples also has excellent step following properties.

Industrial applicability

The colored adhesive sheet of the present invention can be suitably used for bonding display element constituent members in a display element having a black frame, for example, and particularly for bonding a protective panel having a step with a desired display element constituent member.

Claims

1. A colored adhesive sheet comprising a colored adhesive layer comprising an adhesive containing a colorant, and attached to a display element-constituting member having at least two regions of different brightness in the planar direction,

When L1 is the brightness L of one region R1, L2 is the brightness L of the other region R2, L1 'is the brightness L of the region R1 on which the colored adhesive layer is laminated, and L2' is the brightness L of the region R2 on which the colored adhesive layer is laminated, defined by the CIE1976L x a x b x color system, 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 colored adhesive sheet comprising a colored adhesive layer comprising an adhesive containing a colorant, and attached to a display element-constituting member having at least two regions of different brightness in the planar direction,

when L1 is the brightness L of one region R1 and L2 is the brightness L of the other region R2 of the display element constituting member defined by the CIE1976L, a, b, the following formulas (I) and (III) are satisfied:

ΔL＝L1-L2···(I)

ΔL＞0···(III)

the standard deviation of haze values at each wavelength of a 5nm pitch in a wavelength region of 380nm to 780nm of the colored adhesive layer is 0.1 or more.

3. The colored adhesive sheet according to claim 2, wherein when L1 'is the brightness L of the region R1 where the colored adhesive layer is laminated, defined by the CIE1976L x a x b x color system, and L2' is the brightness L of the region R2 where the colored adhesive layer is laminated, the colored adhesive sheet satisfies the following formulas (II) and (IV):

ΔL’＝L1’-L2’···(II)

(ΔL’/ΔL)×100≤80···(IV)。

4. The colored adhesive sheet according to claim 1 or 2, which further satisfies the following formula (V):

ΔL’≤30···(V)。

5. the colored adhesive sheet according to claim 1 or 2, wherein the colored adhesive layer has a brightness L defined by CIE1976L x a x b x color system of 5 to 95.

6. The colored adhesive sheet according to claim 1 or 2, wherein the chromaticity a and the chromaticity b of the colored adhesive layer defined by the CIE1976L x a x b x color system are respectively-7 to 7.

7. The colored adhesive sheet according to claim 1 or 2, wherein the colored adhesive layer has a total light transmittance of 30% or more.

8. The colored adhesive sheet according to claim 1 or 2, wherein the colored adhesive layer has a total light haze value of 0.5% or more and 40% or less.

9. The colored adhesive sheet according to claim 1 or 2, wherein the color of the colorant is a dark color or a dark color.

10. The colored adhesive sheet according to claim 1 or 2, wherein the adhesive is an acrylic adhesive.

11. The colored adhesive sheet according to claim 1 or 2, characterized in that it comprises: and the colored adhesive layer is sandwiched between the two release sheets so as to be in contact with the release surfaces of the two release sheets.

12. The colored adhesive sheet according to claim 1 or 2, which is used for attaching the display-body constituting member to a display-body constituting member different from the display-body constituting member.

13. A display body is provided with: a first display body constituting member having at least two regions of different brightness in a planar direction, a second display body constituting member, and a colored adhesive layer for bonding the first display body constituting member and the second display body constituting member to each other, the display body being characterized in that, when L1 is the brightness L of one region R1, L2 is the brightness L of the other region R2, L1 is the brightness L of the region R1 on which the colored adhesive layer is laminated, and L2 is the brightness L of the region R2 on which the colored adhesive layer is laminated defined by the CIE1976L x a x b x color system, the following formulas (I) to (IV) are satisfied:

ΔL＝L1-L2···(I)

ΔL’＝L1’-L2’···(II)

ΔL＞0···(III)

(ΔL’/ΔL)×100≤80···(IV)。

14. a display body is provided with: the display is characterized in that when the brightness L of one region R1 of the first display component is L1 and the brightness L of the other region R2 is L2, the following formulas (I) and (III) are satisfied, wherein the brightness L of one region R1 is defined by CIE1976L a b, and the brightness L of the other region R1 is L2:

ΔL＝L1-L2···(I)

ΔL＞0···(III)

15. The display device according to claim 13 or 14, wherein at least one of the first display device constituting member and the second display device constituting member has a step on at least a surface on a side to which the colored adhesive layer is attached.

16. A display according to claim 13 or 14, characterized in that it has a black frame material.