TW201922990A - Adhesive sheet and display body in which the cutting property of visible blue light is excellent - Google Patents

Abstract

Provided are an adhesive sheet and a display body excellent in the cutting property of visible blue light. The adhesive sheet 1 includes an adhesive layer 11 for adhering a display body constituting member 21 and another display body constituting member 22. The adhesive layer 11 is composed of an adhesive at least containing a first visible blue light absorbing agent. The first visible blue light absorbing agent has a maximum absorption wavelength between 420 and 500 nm, and the maximum absorption wavelength has a half-peak full width of more than 40 nm and less than 200 nm. In addition, the first visible blue light absorbing agent is composed of a partial anthocyanidin pigment.

Description

Adhesive sheet and display

The present invention relates to a pressure-sensitive adhesive sheet for sticking components of a display body, and a display body using the same.

In recent years, video devices such as televisions, or electronic devices such as personal computers, mobile phones, smart phones, tablet terminals, and game consoles have been used as displays (displays) at high ratios. Among them, LED displays are used. Display body module with light emitting diode (LED element).

A visible light is emitted by the display as described above, but a blue light with a wavelength of 380 to 500 nm is emitted by the LED display. This blue visible light has strong energy and reaches the retina, placing a large burden on the eyes or the body. In particular, this problem has attracted attention since the time spent viewing the display has been prolonged recently.

In order to solve the above-mentioned problems, Patent Document 1 discloses a laminated film, which is a transparent base film laminated with a hue-correcting adhesive layer formed by hardening a composition containing an adhesive resin composition and a compound having an absorption wavelength of 380 to 495 nm. If this laminated film is attached to an LED display, there is a possibility that the blue visible light emitted can be cut. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2015-116713

[Problems to be Solved by the Invention]

It is clear from the test examples that the above-mentioned compounds used in Examples in Patent Document 1 are those that reduce the transmittance of light having a wavelength of 380 to 420 nm. However, this laminated film has insufficient cut-off properties for blue visible light.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is to provide an adhesive sheet and a display having excellent cutoff properties of blue visible light. [Means for solving problems]

To achieve the above object, first, the present invention provides an adhesive sheet including an adhesive layer for adhering one display component and another display component, wherein the adhesive layer includes at least a first The blue visible light absorber is composed of an adhesive. The first blue visible light absorber has a maximum absorption wavelength between 420 and 500 nm, and the full width at half maximum of the maximum absorption wavelength is 40 nm or more and 200 nm or less (Invention 1).

According to the above-mentioned invention (Invention 1), since the total light transmittance can be maintained high, the light emitted by the LED display which occupies most of the blue visible light at 440 to 480 nm, especially at a wavelength near 460 nm, is selective Absorptive, excellent cutoff of blue visible light.

In the above invention (Invention 1), the first blue visible light absorber is preferably composed of a merocyanin pigment (Invention 2).

In the above inventions (Inventions 1, 2), the adhesive contains a second blue visible light absorber, and the second blue visible light absorber has a wavelength lower than a maximum absorption wavelength of the first blue visible light absorber. The maximum absorption wavelength, and the full width at half maximum of the maximum absorption wavelength is 2 nm or more and less than 40 nm (Invention 3).

In the above invention (Invention 3), the second blue visible light absorber is preferably composed of a copper porphyrin complex (Invention 4).

In the above inventions (Inventions 1 to 4), the adhesive is preferably an acrylic adhesive (Invention 5).

In the above inventions (Inventions 1 to 5), the adhesive sheet preferably includes two release sheets, and the adhesive layer sandwiched between the release sheets so as to be in contact with the release surfaces of the two release sheets (Invention 6). .

In the above inventions (Inventions 1 to 6), the total light transmittance of the adhesive layer is preferably 80% or more (Invention 7).

In the above inventions (Inventions 1 to 7), when the content of the first blue visible light absorber in the adhesive layer is X mass%, and when the thickness of the adhesive is Z μm, these preferably satisfy the following formula (I ) (Invention 8). 0.1 ≦ X × Z ≦ 15… (I)

Secondly, the present invention provides a display body including one display body constituent member, another display body constituent member, and an adhesive layer for bonding the one display body constituent member and the other display body constituent member to each other. The adhesive layer is an adhesive layer (Invention 9) of the aforementioned adhesive sheet (Inventions 1 to 8). [Inventive effect]

The adhesive sheet and the display of the present invention are excellent in cutoff of blue visible light.

Hereinafter, embodiments of the present invention will be described. [Adhesive Sheet] An adhesive sheet according to an embodiment of the present invention includes an adhesive layer for adhering one display component and another display component, and is preferably on one side of the adhesive layer or The two-area layer is peeled off. The display and the display component will be described later.

A specific structure of an example of the adhesive sheet according to the embodiment is shown in FIG. 1. As shown in FIG. 1, the adhesive sheet 1 includes two release sheets 12 a and 12 b and an adhesive layer sandwiched by the two release sheets 12 a and 12 b so as to contact the release surfaces of the two release sheets 12 a and 12 b. 11 frames. In addition, the release surface of the release sheet of this specification means the surface which has peelability in a release sheet, and includes one of the surface to which the peeling process was applied, and the surface which shows peelability without the peeling process.

1. Each component 1-1. Adhesive layer The adhesive layer 11 of the adhesive sheet 1 according to this embodiment is composed of at least an adhesive containing a first blue visible light absorber. This first blue visible light absorber has a maximum absorption wavelength between 420 and 500 nm, and the full width at half maximum of the maximum absorption wavelength is 40 nm or more and 200 nm or less. In addition, the "full width at half maximum of the maximum absorption wavelength" refers to the width of the wavelength at which the absorbance at the maximum absorption wavelength is the absorbance (half peak) at half the absorbance at the peak top. When the full width at half maximum is wide, it indicates that absorption is broad, and when the full width at half maximum is small, absorption is sharp. Moreover, the absorption wavelength of blue visible light absorption in this specification is by ultraviolet. The value measured by the visible absorption spectrum method (UV-Vis spectrum method) is specifically a value measured by a method shown in a test example described later.

As a result of diligent research by the inventors of the present invention, it is understood that most of the blue visible light emitted by the LED display is 440 to 480 nm, especially light near 460 nm. Therefore, in the conventional technology such as the invention described in Patent Document 1, even if light having a wavelength of 380 to 420 nm can be cut off, the cutoff of blue visible light is insufficient.

In contrast, the adhesive layer 11 of the adhesive sheet 1 according to this embodiment is composed of the adhesive containing the first blue visible light absorbent as described above, thereby maintaining the total light transmittance to a high level while maintaining the range of 440 to 440 to The selective absorption of light at 480 nm, especially around 460 nm, has excellent cutoff of blue visible light.

From the viewpoint of the cutoff of blue visible light, the maximum absorption wavelength of the first blue visible light absorber is preferably between 430 and 490 nm, and particularly preferably between 440 and 470 nm. The full width at half maximum of the maximum absorption wavelength is preferably 50 nm or more, and particularly preferably 60 nm or more. On the other hand, from the viewpoint of maintaining the total light transmittance high, the full width at half maximum of the maximum absorption wavelength is preferably 150 nm or less, and particularly preferably 80 nm or less.

Furthermore, from the viewpoint of the cutoff of blue visible light and maintaining the total light transmittance, the absorption wavelength range corresponding to the half-peak of the absorbance of the maximum absorption wavelength of the first blue visible light absorber is preferably 350 to 550 nm It is particularly preferably 380 to 530 nm, and still more preferably 400 to 500 nm.

As the first blue visible light absorber as described above, a merocyanin pigment is preferably used. If a merocyanin pigment is used, the absorption wavelength range corresponding to the maximum absorption wavelength, the full width at half maximum of the maximum absorption wavelength, and the half peak of the absorbance at the maximum absorption wavelength easily meet the above-mentioned preferred values.

Moreover, even if the amount of methocyanin pigments added is small, the above-mentioned effects can be exhibited. Therefore, in the adhesive of this embodiment, the methocyanin pigment does not need to be contained in a large amount. Therefore, the methocyanin pigment is not easy to ooze out of the adhesive layer 11 composed of the adhesive, and it is not easy to contaminate the display component or the display . For example, even when the obtained display is left under high temperature and high humidity conditions (for example, 85 ° C, 85% RH) or low temperature conditions (for example, -40 ° C) for 72 hours, the methocyanin pigment is not easy to ooze out.

Examples of merocyanin pigments include 2- [4- (1,3-dibutyltetrahydro-2,4,6-trioxo-5 (2H) -pyrimidinyl) -2-butylene. Alkenyl] -3 (2H) -sodium benzoxazole propane sulfonate, 2- [4- (1,3dibutyltetrahydro-4,6-dioxo-2-thio-5 (2H)- Pyrimidinyl) -2-butenyl] -3 (2H) -benzoxazole propanesulfonate sodium, 3-ethyl-5- [1-[(3-methyl-2 (3H) -benzo Selenoxazolyl) methyl] propylene] -2-thio-4-oxazolinone 4- [4- (3-ethyl-4-oxy-2-thio-5-5-oxazolyl Alkyl) -2-butenyl] -1 (4H) -quinolinepropanesulfonate sodium 2- [6- (3-ethyl-2-benzothiazolyl) -2,4-hexadiene Group] benzo [b] thiophene-3 (2H) -one and the like. These can be used alone or in combination of two or more.

The content X mass% of the first blue visible light absorber in the adhesive is preferably a value that satisfies the following formula (I) when the thickness of the adhesive layer composed of the adhesive is Z μm. 0.1 ≦ X × Z ≦ 15 (I) By setting the value of X × Z to be 0.1 or more, the blue visible light incident on the adhesive layer 11 is sufficiently absorbed, and the cutoff of the blue visible light becomes more excellent. In addition, when the value of X × Z is 15 or less, the degree of coloring of the adhesive layer 11 can be suppressed to be small, and the color of the display can be maintained well. The thickness of the adhesive layer 11 in this specification is a value measured in accordance with JIS K7130.

From the above viewpoint, the lower limit value of X × Z is preferably 0.2 or more, particularly preferably 0.5 or more, and still more preferably 1 or more. The upper limit value of X × Z is preferably 10 or less, particularly preferably 7 or less, and even more preferably 2 or less.

In order to make the value of X × Z easily fall into the above range, the content of the first blue visible light absorbent (X mass%) in the adhesive is preferably 0.005 mass% or more, and particularly preferably 0.01 mass. % Or more, more preferably 0.02 or more. The content (X mass%) of the first blue visible light absorber is preferably 0.5 mass% or less as the upper limit, particularly preferably 0.3 mass% or less, and still more preferably 0.1 mass or less.

In addition to the first blue visible light absorbent, the adhesive preferably contains a second blue visible light absorber, and the second blue visible light absorber is more absorbing than the maximum absorption wavelength of the first blue visible light absorber. The low wavelength side has a maximum absorption wavelength, and the full width at half maximum of the maximum absorption wavelength is 2 nm or more and less than 40 nm. By using the first blue visible light absorber and the second blue visible light absorber in combination in the adhesive, even light around 420 nm that affects visibility can be absorbed uniformly. That is, it is possible to reduce the transmittance while maintaining the balance in the wavelength range of 400 to 500 nm of the original light, so that the change in color balance can be minimized.

According to the above viewpoint, the maximum absorption wavelength of the second blue visible light absorber is preferably between 350 and 470 nm, particularly preferably between 380 and 450 nm, and even more preferably between 400 and 430 nm. On the other hand, the full width at half maximum of the maximum absorption wavelength is preferably 5 nm or more, and particularly preferably 10 nm or more. The full width at half maximum of the maximum absorption wavelength is preferably 30 nm or less, and particularly preferably 20 nm or less.

Furthermore, from the viewpoint of suppressing the change in color balance to a minimum, the absorption wavelength range corresponding to the full width at half maximum of the absorbance at the maximum absorption wavelength of the second blue visible light absorber is preferably 330 to 500 nm, and more particularly It is preferably 350 to 480 nm, and even more preferably 400 to 440 nm.

As the second blue visible light absorber as described above, a copper porphyrin complex is preferably used. If a copper porphyrin complex is used, the absorption wavelength range corresponding to the maximum absorption wavelength, the full width at half maximum of the maximum absorption wavelength, and the half peak of the absorbance at the maximum absorption wavelength easily meet the above-mentioned preferred values.

In addition, the copper porphyrin complex can exhibit the above-mentioned effects even in a small amount of addition. Therefore, in the adhesive of the present embodiment, the copper porphyrin complex does not need to be contained in a large amount. Therefore, the copper porphyrin complex is not easy to ooze out of the adhesive layer composed of the adhesive, and it is not easy to contaminate the display component or display. body. For example, even if the obtained display is left for 72 hours under high temperature and high humidity conditions (for example, 85 ° C, 85% RH) or low temperature conditions (for example, -40 ° C), the copper porphyrin complex is not easy to ooze out. .

The content Y mass% of the second blue visible light absorber in the adhesive is preferably a value that satisfies the following formula (II) when the thickness of the adhesive layer composed of the adhesive is Z μm. 0.01 ≦ Y × Z ≦ 3 (II) When the value of Y × Z is 0.01 or more, the effect of suppressing the change in color balance is more excellent. Furthermore, by setting the value of Y × Z to 3 or less, the degree of coloration of the adhesive layer can be suppressed to be small, and the color of the display can be maintained well.

From the above viewpoint, the lower limit value of Y × Z is preferably 0.05 or more, and particularly preferably 0.1 or more. The upper limit value of Y × Z is preferably 1 or less, and particularly preferably 0.5 or less.

In order to make the value of Y × Z easily fall into the above range, the content of the second blue visible light absorber (Y mass%) in the adhesive is preferably 0.0004 mass% or more, and particularly preferably 0.001 mass. % Or more, more preferably 0.002 or more. The content (Y mass%) of the second blue visible light absorber is preferably 0.1% by mass or less, particularly preferably 0.04% by mass or less, and still more preferably 0.01% by mass or less.

The type of the adhesive constituting the adhesive layer 11 of the adhesive sheet 1 of this embodiment is not particularly limited, and examples thereof include acrylic adhesives, polyester adhesives, and polyurethane adhesives. , Rubber-based adhesive, silicone-based adhesive, etc. In addition, the adhesive may be any of an emulsion type, a solvent type, or a non-solvent type, and may also be a crosslinked type or a non-crosslinked type. Among these, an acrylic adhesive having excellent adhesive properties and optical properties is preferred.

Moreover, as a methacrylic adhesive, it may be an active energy ray-hardenable one or an active energy ray non-hardenable one, but from the viewpoint of compatibility of the photopolymerization initiator and the blue visible light absorber, An active energy ray non-curable acrylic adhesive that does not require a photopolymerization initiator is preferred. As the active energy ray non-hardening acrylic adhesive, a crosslinked type is particularly preferred, and a heat crosslinked type is more preferred.

The adhesive is particularly preferably an adhesive composition containing a (meth) acrylate polymer (A), a crosslinking agent (B), and a blue visible light absorber (C) (hereinafter also referred to as "adhesiveness" Composition P ".) Crosslinked. The blue visible light absorber (C) is the aforementioned first blue visible light absorber, or the first blue visible light absorber and the second blue visible light absorber. The adhesive obtained from the adhesive composition P maintains high total light transmittance and excellent cutoff of blue visible light while exhibiting excellent optical characteristics, adhesion, and durability (high temperature and high humidity). Conditional follow-up)). In addition, in this specification, (meth) acrylic acid means both acrylic acid and methacrylic acid. Other similar terms are the same. The term "copolymer" is also included in "polymer".

(1) Component of Adhesive Composition (1-1) (Meth) acrylate polymer (A) The (meth) acrylate polymer (A) of this embodiment is used as a monomer constituting the polymer. The unit is preferably a reactive group-containing monomer contained in the molecule and having a reactive group that reacts with the crosslinking agent (B). The reactive group derived from the reactive group-containing monomer reacts with the cross-linking agent (B) to form a cross-linked structure (three-dimensional network structure) to obtain an adhesive having a desired cohesive force.

Preferred examples of the reactive group-containing monomer include a monomer having a hydroxyl group in the molecule (a hydroxyl group-containing monomer), a monomer having a carboxyl group in the molecule (a carboxyl group-containing monomer), and a molecule. A monomer having an amine group (a monomer containing an amine group) and the like. Among these, a hydroxyl group-containing monomer which has excellent reactivity with the crosslinking agent (B) and has less adverse effects on the adherend is particularly preferred.

Examples of the hydroxyl-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and (meth) acrylic acid. 2-hydroxybutyl (meth) acrylate, etc., such as 2-hydroxybutyl, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like. Among these, from the viewpoint of the reactivity of the hydroxyl group of the obtained (meth) acrylate polymer (A) with the crosslinking agent (B) and the copolymerizability with other monomers, 2-hydroxy (meth) acrylate is preferred. Ethyl ester and 4-hydroxybutyl (meth) acrylate are particularly preferred, and 2-hydroxyethyl (meth) acrylate is preferred. These can 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, 2-butenoic acid, maleic acid, itaconic acid, and citraconic acid. Among these, acrylic acid is preferred from the viewpoint of the reactivity of the hydroxyl group of the obtained (meth) acrylate polymer (A) with the crosslinking agent (B) and the copolymerizability with other monomers. These can be used alone or in combination of two or more.

Examples of the amine-group-containing monomer include aminoethyl (meth) acrylate and n-butylaminoethyl (meth) acrylate. These can be used alone or in combination of two or more.

The (meth) acrylate polymer (A), as a monomer unit constituting the polymer, preferably contains 3% by mass or more as a lower limit, particularly preferably 10% by mass or more, and more preferably 15% by mass. % Or more of a monomer containing a reactive group. The (meth) acrylate polymer (A), as a monomer unit constituting the polymer, preferably contains 35% by mass or less as the upper limit, particularly preferably 30% by mass or less, and more preferably 25% by mass or less of a reactive group-containing monomer. When the (meth) acrylate polymer (A) contains a reactive group-containing monomer as a monomer unit in the above-mentioned amount, a good cross-linked structure is formed in the obtained adhesive, and a desired cohesive force is obtained. When the reactive group-containing monomer is a hydroxyl group-containing monomer, if the content is 15% by mass or more, a predetermined amount of hydroxyl groups remain in the adhesive. The hydroxyl group is a hydrophilic group. If a predetermined amount of such a hydrophilic group is present in the adhesive, even if the adhesive is placed under high temperature and high humidity conditions, the compatibility with the water that penetrates the adhesive under high temperature and high humidity conditions is good. As a result, the whitening of the adhesive when it was returned to normal temperature and humidity was suppressed (excellent moist heat and whitening resistance was excellent).

The (meth) acrylate polymer (A), as a monomer unit constituting the polymer, preferably does not contain a carboxyl group-containing monomer. The carboxyl group is an acid component, and by not containing a carboxyl group-containing monomer, it is possible to suppress defects caused by an acid due to an adhered object of the adhesive, such as a transparent conductive film or a metal film having indium tin oxide (ITO) or the like In the case of acid, these defects are caused by acid (corrosion, resistance change, etc.). However, to the extent that such defects do not occur, a predetermined amount of a carboxyl group-containing monomer is allowed. Specifically, the (meth) acrylate polymer (A) may contain a carboxyl group as a monomer unit in an amount of 0.1% by mass or less, preferably 0.01% by mass or less, and still more preferably 0.001% by mass or less. Monomer.

The (meth) acrylate polymer (A) preferably contains an alkyl (meth) acrylate as a monomer unit constituting the polymer. As a result, good adhesion can be found. The alkyl group may be linear or branched.

From the viewpoint of adhesion, the alkyl (meth) acrylate is preferably an alkyl (meth) acrylate having 1 to 20 carbon atoms in the alkyl group. Examples of the alkyl (meth) acrylate having 1 to 20 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and ( N-butyl (meth) acrylate, n-amyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, (meth) N-decyl acrylate, n-dodecyl (meth) acrylate, myristyl (meth) acrylate, palmitate (meth) acrylate, stearate (meth) acrylate, and the like. Among them, from the viewpoint of improving adhesion, alkyl (meth) acrylates having 1 to 8 carbon atoms in the alkyl group are preferred, and methyl (meth) acrylate and n- (meth) acrylate are particularly preferred. Butyl or 2-ethylhexyl (meth) acrylate. In addition, these can be used alone or in combination of two or more.

The (meth) acrylate polymer (A), as a monomer unit constituting the polymer, preferably contains 50% by mass or more, more preferably 55% by mass or more, particularly preferably 60% by mass or more, and more It preferably contains more than 65% by mass of alkyl (meth) acrylate. When the lower limit of the content of the (meth) acrylic acid alkyl ester is as described above, the (meth) acrylic acid ester polymer (A) can exhibit appropriate adhesiveness. The (meth) acrylate polymer (A), as a monomer unit constituting the polymer, preferably contains 99% by mass or less, particularly preferably 95% by mass or less, and even more preferably 90% by mass or less. Alkyl (meth) acrylate. If the upper limit of the content of the (meth) acrylic acid alkyl ester is as described above, an appropriate amount of other monomer components such as a reactive functional group-containing monomer can be introduced into the (meth) acrylic acid ester polymer (A). .

The (meth) acrylate polymer (A) is preferably a monomer unit constituting the polymer, and may preferably contain a monomer having an alicyclic structure (a monomer containing an alicyclic structure) in the molecule. . Since the alicyclic structure-containing monomer has a large volume, it is presumed that the distance between the polymers can be widened by allowing the monomer to exist in the polymer, and the obtained adhesive can be made excellent in flexibility. According to this, the adhesive becomes a person with excellent step-followability.

The carbocyclic ring of the alicyclic structure of the monomer containing an alicyclic structure may be a saturated structure or a partially unsaturated bond. Moreover, the alicyclic structure may be a monocyclic alicyclic structure, or a polycyclic alicyclic structure such as a bicyclic ring and a tricyclic ring. From the viewpoints that the obtained (meth) acrylate polymer (A) has a proper distance from one another and imparts higher stress relaxation properties to the adhesive, the alicyclic structure is preferably a polycyclic alicyclic structure ( Polycyclic structure). Furthermore, considering the compatibility of the (meth) acrylate polymer (A) with other components, the above-mentioned polycyclic structure is particularly preferably bicyclic to tetracyclic. In addition, from the viewpoint of imparting stress relaxation similar to the above, the carbon number of the alicyclic structure (refers to the total number of carbons forming the ring portion, and when a plurality of rings exist independently, these total carbon numbers) are usually 5 or more is preferable, and 7 or more is especially preferable. On the other hand, the upper limit of the number of carbons of the alicyclic structure is not particularly limited, but from the viewpoint of compatibility as described above, it is preferably 15 or less, and particularly preferably 10 or less.

Specific examples of the monomer having an alicyclic structure include cyclohexyl (meth) acrylate, dicyclopentyl (meth) acrylate, adamantane (meth) acrylate, and (meth) acrylic acid. Isobornyl ester, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, and the like are preferred from the viewpoint of exhibiting better followability of the step difference. ) Dicyclopentyl acrylate (carbon number of alicyclic structure: 10), Adamantane (meth) acrylate (carbon number of alicyclic structure: 10) or isobornyl (meth) acrylate (alicyclic Structure carbon number: 7), especially isobornyl (meth) acrylate is preferred, and these can be used alone or in combination of two or more.

When the (meth) acrylate polymer (A) contains a monomer containing an alicyclic structure as a monomer unit constituting the polymer, it is preferably contained in an amount of 1% by mass or more, particularly preferably in an amount of 5% by mass or more. Still more preferably, the alicyclic structure-containing monomer is contained in an amount of 10% by mass or more. The (meth) acrylate polymer (A), as a monomer unit constituting the polymer, preferably contains 30% by mass or less, particularly preferably 25% by mass or less, and even more preferably 20% by mass or less. Alicyclic structure-containing monomer. When the content of the alicyclic structure-containing monomer is within the above-mentioned range, the obtained adhesive has more excellent step-followability and more excellent adhesion to plastics.

The (meth) acrylate polymer (A), as a monomer unit constituting the polymer, preferably contains a monomer containing a nitrogen atom. The presence of a nitrogen atom-containing monomer as a constituent unit in the polymer can impart a predetermined polarity to the adhesive, and also has excellent affinity for an adherend having a certain degree of polarity such as glass. As the nitrogen atom-containing monomer, a monomer having a nitrogen-containing heterocyclic ring is preferred from the viewpoint of imparting a moderate rigidity to the (meth) acrylate polymer (A).

Examples of the monomer having a nitrogen-containing heterocyclic ring include N- (meth) acrylfluorenylmorpholine, N-vinyl-2-pyrrolidone, and N- (meth) acrylfluorinylpyrrolidone , N- (meth) acrylfluorenylpiperidine, N- (meth) acrylfluorenyl pyrrolidine, N- (meth) acrylfluorenyl aziridine, (meth) acrylaziridinyl ethyl ester, 2-vinylpyridine, 4-vinylpyridine, 2-vinylpyrazine, 1-vinylimidazole, N-vinylcarbazole, N-vinylphthalimide, etc. Among them, preferred is N- (meth) acrylfluorenylmorpholine exhibiting excellent adhesion is particularly preferred. These can be used alone or in combination of two or more.

When the (meth) acrylate polymer (A) contains a monomer containing a nitrogen atom as a monomer unit constituting the polymer, the polymer preferably contains 1% by mass or more, particularly preferably 2% by mass or more, and more preferably The nitrogen atom-containing monomer is preferably contained in an amount of 3% by mass or more. The (meth) acrylate polymer (A), as a monomer unit constituting the polymer, preferably contains 20% by mass or less, particularly preferably 15% by mass or less, and even more preferably 10% by mass or less. The nitrogen atom-containing monomer. When the content of the nitrogen atom-containing monomer is within the above range, the obtained adhesive can sufficiently exhibit excellent adhesion to glass.

The (meth) acrylate polymer (A) may contain other monomers as a monomer unit constituting the polymer as necessary. As the other monomer, in order not to hinder the aforementioned action of the monomer containing a reactive functional group, a monomer containing no reactive functional group is preferred. Examples of such monomers include alkoxyalkyl (meth) acrylates and vinyl ethyl esters, such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate. , Styrene, etc. These can be used alone or in combination of two or more.

The (meth) acrylate polymer (A) is preferably a linear polymer. Since the polymer is linear, it is easy to cause entanglement of molecular chains, and it is possible to expect an increase in cohesive force, and it is easy to obtain an adhesive with excellent step-followability under high-temperature and high-humidity conditions.

The (meth) acrylate polymer (A) is preferably a solution polymer obtained by a solution polymerization method. By being a solution polymer, since it becomes easy to obtain a high-molecular-weight polymer, an increase in cohesive force can be expected, and an adhesive having excellent step-followability under high-temperature and high-humidity conditions can be easily obtained.

The polymerization type of the (meth) acrylate polymer (A) may be a random copolymer or a block copolymer.

The weight average molecular weight of the (meth) acrylate polymer (A) is preferably 200,000 or more as the lower limit value, particularly preferably 300,000 or more, and still more preferably 400,000 or more. If the lower limit of the weight average molecular weight of the (meth) acrylate polymer (A) is as described above or more, it will be more excellent in the step-followability of the obtained adhesive under high temperature and high humidity conditions.

The weight average molecular weight of the (meth) acrylate polymer (A) is preferably 2 million or less as the upper limit value, particularly preferably 1.5 million or less, and even more preferably 1 million or less. If the upper limit of the weight average molecular weight of the (meth) acrylate polymer (A) is as described above or below, it will be more excellent in the step-followability of the obtained adhesive. In addition, the weight average molecular weight in this specification is a value converted into the standard styrene measured by the gel permeation chromatography (GPC) method.

Furthermore, in the adhesive composition P, a (meth) acrylate polymer (A) may be used individually by 1 type, and may use 2 or more types together.

(1-2) Cross-linking agent (B) The cross-linking agent (B) can cross-link the (meth) acrylate polymer (A) by heating the adhesive composition P, and form a three-dimensional network structure well. As a result, the cohesive force of the obtained adhesive is improved, and the step followability under high temperature and high humidity conditions is excellent.

The cross-linking agent (B) may be any compound capable of reacting with a reactive group of the (meth) acrylate polymer (A). Examples thereof include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, Amine crosslinker, melamine crosslinker, aziridine crosslinker, hydrazine crosslinker, aldehyde crosslinker, oxazoline crosslinker, metal alkoxide crosslinker, metal chelate Compound-based crosslinking agents, metal salt-based crosslinking agents, ammonium salt-based crosslinking agents, and the like. Among the above, when the reactive group of the (meth) acrylate polymer (A) is a hydroxyl group, it is preferable to use an isocyanate-based crosslinking agent having excellent reactivity with the hydroxyl group and polymerize the (meth) acrylate. When the reactive group which the substance (A) has is a carboxyl group, it is preferable to use an epoxy-based crosslinking agent having excellent reactivity with a carboxyl group. Moreover, the crosslinking agent (B) may be used individually by 1 type, and may use 2 or more types together.

The isocyanate-based crosslinking agent contains at least a polyisocyanate compound. Examples of such polyisocyanate compounds include aromatic polyisocyanates such as toluene diisocyanate, diphenylmethane diisocyanate, and xylyl diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; iso Aliphatic polyisocyanates, such as phorone diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like; and biuret bodies, isocyanurate bodies, and further ethylene glycol, propylene glycol, and neopentyl glycol , Trimethylolpropane, castor oil and other reactants containing compounds containing low-molecular active hydrogen, and the like. Among these, from the viewpoint of reactivity with a hydroxyl group, trimethylolpropane-modified aromatic polyisocyanate is preferred, and particularly trimethylolpropane-modified toluene diisocyanate and trimethylolpropane-modified diisocyanate are preferred. Toluene diisocyanate.

Examples of the epoxy-based crosslinking agent include 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, and N, N, N ', N'-tetraglycidyl- M-xylyl diamine, ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidyl aniline, diglycidyl amine, etc. . Among these, from the viewpoint of reactivity with a carboxyl group, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane is preferred.

The content of the crosslinking agent (B) in the adhesive composition P is preferably 0.01 parts by mass or more, and particularly preferably 0.05 parts by mass or more, based on 100 parts by mass of the (meth) acrylate polymer (A). And more preferably 0.1 parts by mass or more. The content is preferably 10 parts by mass or less, particularly preferably 5 parts by mass or less, and still more preferably 0.4 parts by mass or less. When the content of the cross-linking agent (B) is in the above-mentioned range, the obtained adhesive exhibits good cohesive force, and is more excellent in the step-followability under high-temperature and high-humidity conditions.

(1-3) Blue visible light absorber (C) The blue visible light absorber (C) is the aforementioned first blue visible light absorber, or the first blue visible light absorber and the second blue visible light absorber. The specific compound or content is as described above.

(1-4) Various additives In the adhesive composition P, various additives commonly used in acrylic adhesives may be added as needed, such as silane coupling agents, ultraviolet absorbers, antistatic agents, adhesion-imparting agents, antioxidants, Light stabilizer, softener, refractive index adjuster, rust inhibitor, etc. In addition, a polymerization solvent or a dilution solvent described later is not included in the additive constituting the adhesive composition P.

It is preferable that the adhesive composition P contains the silane coupling agent mentioned above. According to this, even if the adherend is a plastic plate or a glass component, it becomes the one that improves the adherence to the adherend and has better followability of the step difference under high temperature and high humidity conditions.

As the silane coupling agent, an organosilicon compound having at least one alkoxysilyl group in the molecule, and having good compatibility with the (meth) acrylate polymer (A) and having light transmittance are preferred.

Examples of such silane coupling agents include polymerizable unsaturated group-containing silicon compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, and methacryloxypropyltrimethylsilane. Silicon compounds with epoxy structure, such as 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-mercaptopropyl Mercapto-containing silicon compounds such as trimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyldimethoxymethylsilane, 3-aminopropyltrimethoxysilane, N- (2 -Aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, and other amine-containing silicon compounds , Trichloropropyltrimethoxysilane, triisocyanatepropyltriethoxysilane, or at least one of these with methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxy Condensates of alkyl-containing silicon compounds such as silanes and ethyltrimethoxysilanes. These may be used individually by 1 type, and may use 2 or more types together.

The content of the silane coupling agent in the adhesive composition P is preferably 0.01 parts by mass or more, particularly preferably 0.05 parts by mass or more, based on 100 parts by mass of the (meth) acrylate polymer (A). It is preferably at least 0.1 parts by mass. The content is preferably 1 part by mass or less, particularly preferably 0.5 part by mass or less, and still more preferably 0.3 part by mass or less.

(2) Preparation of adhesive composition The adhesive composition P can be produced by the following method: (meth) acrylate polymer (A) is produced, and the obtained (meth) acrylate polymer (A) is crosslinked. When the agent (B) and the blue visible light absorber (C) are mixed, additives are added as needed to manufacture.

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) acrylate polymer (A) is preferably performed by a solution polymerization method using a polymerization initiator as necessary. Examples of the polymerization solvent include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, and methyl ethyl ketone, and two or more kinds may be used in combination.

Examples of the polymerization initiator include an azo compound, an organic peroxide, and the like, and two or more kinds may be used in combination. Examples of the azo compound include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), and 1,1'-azobis (cyclo Hexane 1-nitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxypentyl) Nitrile), dimethyl 2,2'-azobis (2-methylpropionate), 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis ( 2-hydroxymethylpropionitrile), 2,2'-azobis [2- (2-imidazolin-2-yl) propane] and the like.

Examples of the organic peroxide include benzamidine peroxide, ethyl tert-butylperbenzoate, cumene hydroperoxide, diisopropyl peroxide dicarbonate, and di-n-propyl peroxide. Oxidized dicarbonate, bis (2-ethoxyethyl) peroxydicarbonate, third butyl neodecyl peroxide, third butyl trimethylacetate, (3,5,5 -Trimethylhexyl) peroxide, dipropylfluorenyl peroxide, diethylfluorenyl peroxide, and the like.

Moreover, in the said polymerization process, the weight average molecular weight of the polymer obtained can be adjusted by mix | blending a chain shifting agent, such as 2-mercaptoethanol.

When a (meth) acrylate polymer (A) is obtained, a cross-linking agent (B), a blue visible light absorber (C) is added to the (meth) acrylate polymer (A) solution, and if necessary, The solvent or the additive is diluted, and the adhesive composition P (coating solution) diluted with the solvent is obtained by thorough mixing. In addition, in the case where a solid substance is used in any of the above components, or when precipitation occurs when it is mixed with other components in an undiluted state, the component may be separately dissolved or diluted in a dilution solvent in advance, Mix with other ingredients.

Examples of the diluting solvent include aliphatic hydrocarbons such as hexane, heptane, and cyclohexane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as dichloromethane and dichloroethane; and methanol and ethanol. , Alcohols such as propanol, butanol, 1-methoxy-2-propanol, ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, cyclohexanone, ethyl acetate, Esters such as butyl acetate, cellulose solvents such as ethyl cellulose, and the like.

As the concentration of the coating solution prepared in this way. The viscosity is not particularly limited as long as it is a coatable range, and can be appropriately selected depending on the situation. For example, it dilutes so that the density | concentration of the adhesive composition P may become 10-60 mass%. When a coating solution is obtained, the addition of a diluent solvent or the like is not necessary. For example, if the adhesive composition P has a coatable viscosity, the diluent solvent may not be added. In this case, the adhesive composition P becomes a coating solution in which the polymerization solvent of the (meth) acrylate polymer (A) is directly used as a diluent.

(3) Formation of Adhesive Layer The adhesive layer 11 of the embodiment is preferably composed of an adhesive in which the adhesive composition P (coating layer) is crosslinked. Crosslinking of the adhesive composition P can usually be performed by heat treatment. In addition, this heat treatment can also be used as a drying treatment when the diluent solvent and the like are volatilized from the coating layer of the adhesive composition P applied to a desired object.

The heating temperature in the heat treatment is preferably 50 to 150 ° C, and particularly preferably 70 to 120 ° C. The heating time is preferably 10 seconds to 10 minutes, and particularly preferably 50 seconds to 2 minutes.

After heating, if necessary, a health period of about 1 to 2 weeks can be set at normal temperature (for example, 23 ° C, 50% RH). This health period is necessary. After the health period, an adhesive is formed. In the case where a health period is not required, an adhesive is formed after the heat treatment is completed.

The (meth) acrylate polymer (A) is sufficiently crosslinked via the crosslinking agent (B) by the heat treatment (and health preservation) described above. The adhesive obtained in this way is excellent in the step-followability 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 gel fraction of the adhesive according to this embodiment is preferably 40% or more as a lower limit value, particularly preferably 50% or more, and still more preferably 55% or more. If the lower limit value of the gel fraction of the adhesive is as described above, the cohesive force of the adhesive becomes high, and the step-following performance under the conditions of high temperature and high humidity becomes better. In addition, the gel fraction of the adhesive of the present embodiment is preferably 98% or lower, more preferably 90% or lower, particularly preferably 80% or lower, and still more preferably 70% or lower. If the upper limit of the gel fraction of the adhesive is as described above, the adhesive does not become too hard, and it is found that the adhesive has good adhesion and has better adhesion to the adherend. Here, the measurement method of the gel fraction of an adhesive agent is as shown in the test example mentioned later.

(4-2) Storage modulus The 23 ° C storage modulus of the adhesive of this embodiment is preferably 0.01 MPa or more as the lower limit value, particularly preferably 0.03 MPa or more, and still more preferably 0.05 MPa or more. . By setting the lower limit value of the storage modulus as described above, it becomes the one having excellent step-followability under high-temperature and high-humidity conditions. The upper limit of the storage modulus is preferably 0.5 MPa or less, particularly preferably 0.3 MPa or less, and still more preferably 0.15 MPa or less. By setting the upper limit value of the storage modulus as described above, it becomes a person with excellent initial stage followability. The storage modulus of this specification is a value measured by a torsional shear method at a measurement frequency of 1 Hz in accordance with JIS K7244-6. Specifically, it is as shown in the test example mentioned later.

(5) Thickness of the adhesive layer The thickness (Zμm) of the adhesive layer 11 of the adhesive sheet 1 of this embodiment is preferably a value satisfying the aforementioned formula (I) of X × Z, and more preferably Y × Z. The value of formula (II).

Specifically, the thickness of the adhesive layer 11 is preferably 5 μm or more, more preferably 30 μm or more, and particularly preferably 50 μm or more as a lower limit value. As described above, the lower limit value of the thickness of the adhesive layer 11 is easily related to the concentration of the blue visible light absorber (C), and it is easy to exhibit excellent blue visible light cutoff, and it is easy to exhibit a desired adhesive force. Furthermore, from the viewpoint that the step followability is more excellent, the thickness of the adhesive layer 11 is more preferably 70 μm or more.

The thickness of the adhesive layer 11 is preferably 1000 μm or less, more preferably 600 μm or less, particularly preferably 300 μm or less, and still more preferably 200 μm or less. If the upper limit of the thickness of the adhesive layer 11 is as mentioned above, it becomes a thing with favorable processability. In addition, appearance defects such as indentation are unlikely to occur. In addition, the adhesive layer 11 may be formed as a single layer, or may be formed by stacking a plurality of layers.

1-2. Release sheet The release sheets 12a and 12b protect the adhesive layer 11 when the adhesive sheet 1 is used, and are peeled off when the adhesive sheet 1 (adhesive layer 11) is used. In the adhesive sheet 1 of this embodiment, one or both of the release sheets 12a and 12b are not necessary.

Examples of the release sheets 12a and 12b include polyethylene films, polypropylene films, polybutene films, polybutadiene films, polymethylpentene films, polyvinyl chloride films, vinyl chloride copolymer films, and the like. Polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate film, ionic polymer resin film, ethylene ． (Meth) acrylic copolymer film, ethylene. (Meth) acrylate copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, etc. These crosslinked films can also be used. Furthermore, these laminated films can also be used.

It is preferable to apply a peeling process to the peeling surface (especially the surface which contacts the adhesive layer 11) of the said peeling sheet 12a, 12b. Examples of the release agent used for the release treatment include alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, and wax-based release agents. In addition, among the release sheets 12a and 12b, it is preferable that one of the release sheets is a heavy release type release sheet having a large peeling force, and the other release sheet is a light release type release sheet having a small peeling force.

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

2. Physical properties (1) Total light transmittance The total light transmittance (value measured in accordance with JIS K7361-1: 1997) of the adhesive layer 11 of the adhesive sheet 1 of this embodiment is preferably 80% or more, especially It is preferably 90% or more, and even more preferably 95% or more. As described above, the total light transmittance is highly transparent and suitable for use as an optical application (for a display body). Since the aforementioned blue visible light absorber (C) easily and selectively absorbs light having a wavelength of 440 to 480 nm, this embodiment can maintain a high total light transmittance as described above.

(2) Transmittance at each wavelength The transmittance at the wavelength of 420 nm of the adhesive layer 11 of the adhesive sheet 1 of this embodiment is preferably 90% or less, particularly preferably 85% or less, and more preferably It is 80% or less. As a result, it has a good cutoff of blue visible light near this wavelength. From the viewpoint of maintaining the original color balance of 420 to 480 nm, it is preferably 60% or less. On the other hand, the lower limit of the transmittance at a wavelength of 420 nm is preferably 30% or more, particularly preferably 40% or more, and still more preferably 50% or more. Accordingly, the color of the display can be maintained well.

The transmittance of the wavelength of 440 nm of the adhesive layer 11 of the adhesive sheet 1 of this embodiment is preferably 90% or less, particularly preferably 85% or less, and even more preferably 80% or less. As a result, it has a good cutoff of blue visible light near this wavelength. Further, from the viewpoint of maintaining the original color balance of 420 to 480 nm, it is preferably 65% or less. On the other hand, the lower limit of the transmittance at a wavelength of 440 nm is preferably 30% or more, particularly preferably 40% or more, and still more preferably 50% or more. Accordingly, the color of the display can be maintained well.

The transmittance at a wavelength of 460 nm of the adhesive layer 11 of the adhesive sheet 1 of this embodiment is preferably 90% or less, particularly preferably 70% or less, and still more preferably 60% or less. As a result, it has a good cutoff of blue visible light near this wavelength. On the other hand, the lower limit of the transmittance at a wavelength of 460 nm is preferably 30% or more, particularly preferably 40% or more, and still more preferably 50% or more. Accordingly, the color of the display can be maintained well.

The transmittance at the wavelength of 480 nm of the adhesive layer 11 of the adhesive sheet 1 of this embodiment is preferably 90% or less, particularly preferably 70% or less, and still more preferably 60% or less. As a result, it has a good cutoff of blue visible light near this wavelength. On the other hand, the lower limit of the transmittance at a wavelength of 480 nm is preferably 30% or more, particularly preferably 40% or more, and still more preferably 50% or more. Accordingly, the color of the display can be maintained well.

The difference between the maximum value and the minimum value of the transmittance of the adhesive layer 11 of the adhesive sheet 1 of the embodiment 1 at a wavelength of 420 to 480 nm is preferably 60 points or less, particularly preferably 30 points or less, and even more preferably 8 Click below. By setting the difference between the maximum value and the minimum value of the transmittance at a wavelength of 420 to 480 nm as described above, light in this wavelength range can be absorbed uniformly, and the color balance of the display can be well maintained. Moreover, the lower limit of the difference between the maximum value and the minimum value of the transmittance at the wavelength of 420 to 480 nm is not particularly limited, but is preferably 0.2 or more, particularly preferably 1 or more, and even more preferably 4 the above.

The specific measurement method of the transmittance | permeability of each said wavelength is as shown to the test example mentioned later.

(3) Adhesion The adhesion of the adhesive sheet 1 of this embodiment to soda-lime glass is preferably 1N / 25mm or more as the lower limit, particularly preferably 5N / 25mm or more, and even more preferably 25N / 25mm or more. If the lower limit of the adhesive force is as described above, the step-followability under the conditions of high temperature and high humidity is more excellent. Furthermore, the upper limit of the adhesion force of the adhesive sheet 1 to the soda-lime glass according to this embodiment is preferably 100 N / 25 mm or less, more preferably 80 N / 25 mm or less, and particularly preferably 50 N / 25 mm or less. If the upper limit of the adhesive force is as described above, good reworkability is obtained. In the case where a bonding error occurs, the display body component, especially the expensive display body component, can be reused.

Here, the adhesive force in the present specification basically refers to an adhesive force measured according to the 180-degree peeling method of JIS Z0237: 2009. The measurement sample is 25 mm wide and 100 mm long, and the measurement sample is attached to a substrate. The body was pressed at 0.5 MPa and 50 ° C. for 20 minutes, and then left to stand for 24 hours under the conditions of normal pressure 23 ° C. and 50% RH, and measured at a peeling speed of 300 mm / min.

3. Production of Adhesive Sheet As an example of the production of the adhesive sheet 1, the coating solution of the adhesive composition P is applied to the release surface of one release sheet 12a (or 12b), and heat treatment is performed to heat-seal. After the adhesive composition P is connected, and this coating layer is formed, this coating layer is overlapped with the release surface of another release sheet 12b (or 12a). In the case where a health period is needed, the above-mentioned coating layer becomes the adhesive layer 11 by placing the health period so that the coating layer becomes the adhesive layer 11. Thus, the above-mentioned adhesive sheet 1 was obtained. The heat treatment and health conditions are the same as described above.

As another manufacturing example of the adhesive sheet 1, the coating solution of the adhesive composition P is applied to the release surface of one release sheet 12a, and heat treatment is performed to thermally crosslink the adhesive composition P to form a coating layer. Thus, a release sheet 12a with a coating layer was obtained. Then, the coating solution of the adhesive composition P is applied to the release surface of the other release sheet 12b, and the heat treatment is performed to thermally crosslink the adhesive composition P to form a coating layer to obtain a coating layer. Of release sheet 12b. Then, the two application layers of the release sheet 12a with a coating layer and the two coating layers of the release sheet 12b with a coating layer are in contact with each other. Here, a plurality of release sheets with a coating layer may be produced, and the coating layers may be laminated only as many as desired. In the case where a health period is required, by placing the health period so that the above-mentioned laminated coating layer becomes the adhesive layer 11, when the health period is not required, the above-mentioned laminated coating layer becomes the adhesive layer 11. Thus, the above-mentioned adhesive sheet 1 was obtained. According to this manufacturing example, even when the adhesive layer 11 is thick, it can be manufactured stably.

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

[Display Body] As shown in FIG. 2, the display body 2 of this embodiment includes a first display body component 21 (one display body component), a second display body component 22 (the other display body component), and The adhesive layer 11 is located between these, and the 1st display body structural member 21 and the 2nd display body structural member 22 are mutually adhere | attached. In the display body 2 of this embodiment, the surface of the first display member 21 on the side of the adhesive layer 11 may have a step difference such as the printing layer 3.

The adhesive layer 11 of the display body 2 is the adhesive layer 11 of the aforementioned adhesive sheet 1.

The display body 2 is, for example, a liquid crystal (LCD) display, a light emitting diode (LED) display, an organic electroluminescence (organic EL) display, an electronic paper, or the like, and may also be a touch panel. The display body 2 may be a member constituting part of these.

In addition to the glass plate, the plastic plate, and the like, the first display body constituting member is preferably a protective panel including such a laminated body. In this case, the print layer 3 is generally formed in a frame shape on the adhesive layer 11 side of the first display body constituent member 21.

The glass substrate is not particularly limited, and examples thereof include chemically strengthened glass, alkali-free glass, quartz glass, soda lime glass, and barium-containing glass. Strontium glass, aluminum silicate glass, lead glass, borosilicate glass, barium borosilicate glass, etc. The thickness of the glass plate is not particularly limited, but is usually 0.1 to 5 mm, and preferably 0.2 to 2 mm.

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

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

The second display component 22 is an optical component to be attached to the first display component 21, and is preferably a display module (for example, a liquid crystal (LCD) module, a light emitting diode (LED) module, an organic electric Electroluminescence (organic EL) modules, etc.), optical components as part of a display module, or a multilayer body containing a display module.

Examples of the optical components include explosion-proof films, polarizing plates (polarizing films), polarizers, retardation plates (phase retardation films), viewing angle compensation films, brightness enhancement films, contrast enhancement films, liquid crystal polymer films, diffusion films, Transflective film, transparent conductive film, etc. The explosion-proof film is, for example, a hard coat film formed by forming a hard coat layer on one side of a base film.

The material constituting the printed layer 3 is not particularly limited, and a known material for printing is used. The thickness of the printed layer 3, that is, the lower limit of 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 the above, the concealability such as being invisible to the viewer can be sufficiently ensured. The upper limit value is preferably 50 μm or less, more preferably 35 μm or less, particularly preferably 25 μm or less, and still more preferably 20 μm or less. By setting the upper limit value to be equal to or less than the above value, it is possible to prevent deterioration in the followability of the adhesive layer 11 to the printing layer 3.

In the manufacturing of the above-mentioned display body 2, as an example, the release sheet 12a on one side of the adhesive sheet 1 is peeled off, and the adhesive layer 11 exposed by the adhesive sheet 1 is bonded to the side where the printed layer 3 of the first display body component 21 exists surface.

After that, the other release sheet 12 b is peeled off from the adhesive layer 11 of the adhesive sheet 1, and the adhesive layer 11 exposed by the adhesive sheet 1 is bonded to the second display component 22. Furthermore, as another example, the bonding order of the first display body constituent member 21 and the second display body constituent member 22 may be exchanged.

In the display body 2 described above, the blue visible light of the light emitted from the display body module is selectively and sufficiently absorbed by the adhesive 11. Therefore, the display body 2 of the present embodiment can exhibit excellent blue visible light cut-off while maintaining a high total light transmittance.

Moreover, in the case where the first blue visible light absorber contained in the adhesive layer 11 of the display 2 is a merocyanin pigment and the second blue visible light absorber is a copper porphyrin complex, these compounds are not easy Exudation inhibits the display body constituent members 21, 22 or the display body 2 from being contaminated by these blue visible light absorbers.

Furthermore, in the case where the adhesive layer 11 is formed of the adhesive composition P in the display body 2 described above, since the adhesive layer 11 has excellent step-followability under high temperature and high humidity conditions, the display body 2 is placed on Under high temperature and high humidity conditions (for example, 85 ° C, 85% RH), the occurrence of floating and peeling near the step is suppressed.

The embodiments described above are described for easy understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above-mentioned embodiment is intended to include all design changes or equivalents described in the technical scope of the present invention.

For example, one or both of the release sheets 12a and 12b of the adhesive sheet 1 may be omitted, and a desired optical component may be laminated instead of the release sheet 12a and / or the release sheet 12b. In addition, the first display body constituent member 21 may be one without step. Furthermore, not only the first display body constituent member 21 but also the second display body constituent member 22 may have a step on the adhesive layer 11 side. [Example]

Hereinafter, the present invention will be specifically described by examples and the like, but the scope of the present invention is not limited to these examples and the like.

[Example 1] 1. Preparation of (meth) acrylate polymer 60 parts by mass of n-butyl acrylate, 20 parts by mass of methyl acrylate, and 20 parts by mass of 2-hydroxyethyl acrylate were copolymerized by a solution polymerization method. To prepare a (meth) acrylate polymer (A). The molecular weight of this (meth) acrylate (A) was measured by the method described later, and the weight average molecular weight was 600,000.

2. Preparation of Adhesive Composition 100 parts by mass of the (meth) acrylate polymer (A) obtained in the above step 1 (solid content conversion value; the same applies hereinafter), and trimethylol as a crosslinking agent (B) 0.25 parts by mass of propane-modified toluene diisocyanate (manufactured by Toyo Chemical Co., Ltd., product name "BHS8515"), and an anthocyanin pigment (manufactured by Yamada Chemical Industry Co., Ltd., product name "FDB-006") as a blue visible light absorber (C) ") 0.025 parts by mass and 0.25 parts by mass of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent are mixed and sufficiently stirred, and diluted with methyl ethyl ketone to obtain a coating of the adhesive composition. Cloth solution.

Here, each blending (solid content conversion value) of the adhesive composition when (meth) acrylate polymer (A) is 100 mass parts (solid content conversion value) is shown in Table 1. The details of the abbreviations and the like described in Table 1 are as follows. [(Meth) acrylate polymer (A)] BA: n-butyl acrylate MA: methyl acrylate HEA: 2-hydroxyethyl acrylate 2EHA: 2-ethylhexyl acrylate ACMO: N-propenyl morpholine IBXA: isobornyl acrylate AA: acrylic acid [crosslinking agent (B)] TDI: trimethylolpropane modified toluene diisocyanate (manufactured by Toyo Chemical Co., Ltd., product name "BHS8515") XDI: trimethylolpropane modified Xylene diisocyanate (manufactured by Soken Chemical Co., Ltd., product name "TD-75") Epoxy: 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd., product Name "TETRAD-C") [Blue visible light absorber (C)] Anthocyanin pigment (manufactured by Yamada Chemical Industry Co., Ltd., product name "FDB-006") Copper porphyrin complex (manufactured by Yamada Chemical Industry Co., Ltd., Product name "FDB-001")

3. Manufacture of an adhesive sheet The coating solution of the adhesive composition obtained in the above step 2 was applied to a single side of a polyethylene terephthalate film with a knife coater and subjected to a release treatment with a silicone-based release agent. The release-treated surface of the heavy release-type release sheet (manufactured by Lindec Corporation, product name "SP-PET752150") was then heated at 90 ° C. for 1 minute to form a coating layer (thickness: 50 μm). The light-peelable release sheet (Linder) of the obtained heavy-peelable release sheet with a coating layer on the side of the coating layer, which was subjected to a release treatment with a silicone-based release agent on one side of a polyethylene terephthalate film. Co., Ltd., product name "SP-PET38113") was bonded to the peeled surface, and it was cured at 23 ° C and 50% RH for 7 days to produce a heavy peeling release sheet / adhesive layer (thickness: 50 μm) ) / Adhesive sheet composed of light release type release sheet.

In addition, the thickness of the said adhesive layer is a value measured using the constant pressure thickness measuring device (made by TECLOCK, product name "PG-02") based on JISK3170.

[Examples 2 to 4, 6 to 10, and Comparative Examples 1 to 12] In addition to the types and ratios of the respective monomers constituting the (meth) acrylate polymer (A), the (meth) acrylate polymer (A ) The weight average molecular weight (Mw), the type and blending amount of the cross-linking agent (B), the type and blending amount of the blue visible light absorber (C), and the blending amount of the silane coupling agent are changed as shown in Table 1. A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1.

[Example 5] 1. Preparation of Adhesive Composition 100 parts by mass of a (meth) acrylate polymer (A) prepared in the same manner as in Example 1 and a trimethylol group as a crosslinking agent (B) 0.25 parts by mass of propane-modified toluene diisocyanate (manufactured by Toyo Chemical Co., Ltd., product name "BHS8515"), and an anthocyanin pigment (manufactured by Yamada Chemical Industry Co., Ltd., product name "FDB-006") as a blue visible light absorber (C) ") 0.008 parts by mass and copper porphyrin complex (manufactured by Yamada Chemical Industry Co., Ltd., product name" FDB-001 ") 0.002 parts by mass and 3-glycidoxypropyltrimethoxysilane as a silane coupling agent (Manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name "KBM-403") 0.25 parts by mass was mixed and sufficiently stirred, and diluted with methyl ethyl ketone to obtain a coating solution of an adhesive composition.

2. Production of adhesive sheet The coating solution of the adhesive composition obtained in the above step 1 was applied to a single side of a polyethylene terephthalate film by a knife coater and subjected to a release treatment with a silicone-based release agent. A peeled surface of a heavy release type release sheet (manufactured by Lindec Corporation, product name "SP-PET752150") was then heated at 90 ° C for 1 minute to form a coating layer (thickness: 50 μm), thereby producing a coating with coating. Layer of a heavy release type release sheet.

On the other hand, the coating solution of the adhesive composition obtained in the above step 1 was lightly peeled off by applying a silicone-based release agent on one side of a polyethylene terephthalate film with a knife coater using a knife coater. Type peeling sheet (manufactured by Lindec Corporation, product name "SP-PET38113"), and then heated at 90 ° C for 1 minute to form a coating layer having a thickness of 50 µm, thereby producing two 50 µm thick coatings Light-peeling release sheet for cloth layer.

Affixing the surface of the coating layer side of the heavy-peeling release sheet with a coating layer obtained above to the surface of the coating layer side of the light-peeling type peeling sheet with a coating layer having a thickness of 50 μm obtained above, A first laminated body was obtained in which a coating layer having a total thickness of 100 μm was sandwiched between a heavy release type release sheet and a light release type release sheet.

Next, another surface of the coating layer side of the light-peeling type release sheet with a coating layer having a thickness of 50 μm obtained as described above was attached to the coating layer exposed by the first laminated body peeling light-peeling type release sheet. Thus, a second laminate having a coating layer with a total thickness of 150 μm sandwiched between a heavy release type release sheet and a light release type release sheet was obtained.

The second laminated body was cured at 23 ° C. and 50% RH for 7 days to prepare an adhesive sheet composed of a heavy release type release sheet / adhesive layer (thickness: 150 μm) / light release type release sheet. .

Moreover, the content of the methocyanin pigment in the adhesive layer (adhesive composition) formed by the Example and the comparative example was X mass%, and X * Z when the thickness of the adhesive layer was Z micrometer. Similarly, the content of the copper porphyrin complex in the adhesive layer (adhesive composition) formed in the examples and comparative examples was calculated as Y mass%, and the thickness of the adhesive layer was Y × Z when the thickness of the adhesive layer was Z μm. The results are shown in Table 1.

Here, the aforementioned weight average molecular weight (Mw) is a polystyrene equivalent weight average molecular weight measured using a gel permeation chromatography (GPC) under the following conditions (GPC measurement). <Measurement conditions>. GPC measuring device: manufactured by Tosoh Corporation, HLC-8020. GPC column (passed in the following order): TSK guard column HXL-H TSK gel GMHXL (× 2) TSK gel G2000HXL manufactured by Tosoh Corporation. Measurement solvent: tetrahydrofuran. Measurement temperature: 40 ° C

[Test Example 1] (Measurement of Absorption Spectrum) The merocyanin pigment and copper porphyrin complex used in the examples and comparative examples were diluted 100,000 times with toluene, and these were used as samples. The obtained sample was spectrophotometer (manufactured by Shimadzu Corporation, product name: "UV-VIS-NIR SPECTROPHOTOMETER UV-3600") and subjected to ultraviolet light. The visible light absorption spectrum method (UV-Vis spectrum method) is used to measure the absorption spectrum. A graph as a measurement result of the merocyanin pigment is shown in FIG. 3, and a graph as a measurement result of the copper porphyrin complex is shown in FIG. 4.

According to FIG. 3, the maximum absorption wavelength of the aforementioned anthocyanin pigment is 449 nm, and the absorption wavelength range corresponding to the half-peak of the absorbance at the maximum absorption wavelength is 418 to 482 nm. The full-width at half maximum of the maximum absorption wavelength can be read as 64nm. Furthermore, according to FIG. 4, the maximum absorption wavelength of the copper porphyrin complex is 421 nm, and the absorption wavelength range corresponding to the half-peak of the absorbance at the maximum absorption wavelength is 415 to 428 nm. The full-width at half maximum of the maximum absorption wavelength may be Read as 13nm.

[Test Example 2] (Measurement of Gel Fraction) The adhesive sheets obtained in Examples and Comparative Examples were cut to a size of 80 mm × 80 mm, and this adhesive layer was covered with a polyester mesh (mesh size 200) and precision The balance weighs its mass, and subtracts the mass of the net alone to calculate the mass of the adhesive only. The mass at this time is M1.

Next, the polyester mesh-coated adhesive was immersed in ethyl acetate at room temperature (23) for 24 hours. Thereafter, the adhesive was taken out and air-dried in an environment at a temperature of 23 ° C and a relative humidity of 50% for 24 hours, and then dried in an oven at 80 ° C for 12 hours. After drying, the mass was measured with a precision balance, and the mass of only the adhesive was calculated by subtracting the mass of the net alone. The mass at this time was M2. The gel fraction (%) is expressed as (M2 / M1) × 100. The results are shown in Table 2.

[Test Example 3] (Measurement of storage modulus) The peeling sheet was peeled from the adhesive sheet obtained in the experimental example and the comparative example, and a plurality of layers were laminated so that the adhesive layer had a thickness of 3 mm. A cylindrical body (height 3 mm) having a diameter of 8 mm was punched out from the obtained laminated body of the adhesive layer, and this was used as a sample.

About the said sample, the storage modulus (MPa) was measured by the torsional shear method using the viscoelasticity measuring device (made by Physica company, product name "MCR300") based on JISK7244-6 on the following conditions. The results are shown in Table 2. Measurement frequency: 1Hz Measurement temperature: 23 ° C

[Test Example 4] (Measurement of Adhesive Strength) The light-peelable release sheet was peeled from the adhesive sheets obtained in Examples and Comparative Examples, and the exposed adhesive layer was bonded to polyethylene terephthalate having an easy-adhesive layer. (PET) film (manufactured by Toyobo Co., Ltd., product name "PET A4300", thickness: 100 µm), an easy-adhesive layer, to obtain a laminate of a release sheet / adhesive layer / PET film. The obtained laminated body was cut into a width of 25 mm and a length of 100 mm, and these were used as samples.

In a 23 ° C, 50% RH environment, the re-peeling type peeling sheet was peeled from the above sample, and the exposed adhesive layer was attached to a soda-lime glass (manufactured by Nippon Sheet Glass Co., Ltd.), followed by Kurihara Manufacturing Co., Ltd. The manufactured sterilizer was pressurized at 0.5 MPa and 50 ° C for 20 minutes. After that, it was left to stand at 23 ° C and 50% RH for 24 hours. Then, using a tensile tester (manufactured by ORIENTEC, product name "TENSILON"), the adhesion was measured at a peeling speed of 300 mm / min and a peeling angle of 180 degrees. Force (N / 25mm). Conditions other than those described here are measured in accordance with JIS Z 0237: 2009. The results are shown in Table 2.

[Test Example 5] (Measurement of total light transmittance) The adhesive layer of the adhesive sheets obtained in Examples and Comparative Examples was bonded to glass, and this was used as a measurement sample. After measuring the background with glass in accordance with JIS K7361-1: 1997, the total light transmittance (%) was measured using a haze meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., product name "NDH-2000") after measuring the background with glass. . The results are shown in Table 2.

[Test Example 6] (Measurement of transmittance) The adhesive layer of the adhesive sheets obtained in the examples and comparative examples was bonded to glass, and this was used as a measurement sample. After measuring the background with a blank sample, the adhesive layer was measured for transmittance using a spectrophotometer (manufactured by Shimadzu Corporation, product name: "UV-VIS-NIR SPECTROPHOTOMETER UV-3600"), and the wavelengths of 420 nm, 440 nm, and 420 nm were extracted. Light transmittance (%) at 460nm and 480nm. The measurement was performed using the attached large sample chamber MPC-3100, without using a built-in integrating sphere. The results are shown in Table 2.

[Experimental Example 7] (Evaluation of Followability of Steps) On a surface of a glass plate (manufactured by NSG Precision, product name "Corning glass Eagle XG", 90 mm in width x 50 mm in width x 0.5 mm in thickness), a UV-curable ink (Imperial Made by Ink Co., Ltd., product name "POS-911 Ink") Screen printing (frame shape: 90mm in length x 50mm in width, 5mm in width). Next, ultraviolet rays (80 W / cm ² , ^two metal halide lamps, lamp height 15 cm, belt speed 10 to 15 m / min) were irradiated to harden the printed UV-curable ink to produce step differences due to printing (step difference height: 5 μm, 10 μm) with a stepped glass plate.

The light-peelable release sheet was peeled from the adhesive sheets obtained in the examples and comparative examples, and the exposed release agent layer was bonded to a polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name "PET A4300") ”, Thickness: 100 μm). After that, the heavy release-type release sheet was peeled to expose the adhesive layer. Then, using a lamination device (manufactured by FUJIPLA, product name "LPD3214"), the above-mentioned laminated volume layer was laminated on each of the stepped glass plates so that the adhesive layer covered the frame-shaped printing. Sample.

The obtained evaluation sample was subjected to a 30-minute sterilization retort treatment at 50 ° C and 0.5 MPa, and then left at normal pressure, 23 ° C, and 50% RH for 24 hours. Next, it was stored for 72 hours (durability test) under a humid heat condition of 85 ° C. and 85% RH, and then the step followability was evaluated based on the following criteria. Moreover, the followability of the step difference is judged to be good when the printing step difference is completely buried by the adhesive layer, and a floating or peeling is observed at the interface between the printing step difference and the adhesive layer, and it is determined that the printing step difference cannot be followed. The results are shown in Table 2. ◎: 10 μm difference in the printing step is good ○: 5 μm difference in the printing step is good ×: Floating and peeling is 5 m difference in printing step

[Test Example 8] (Evaluation of exudability) The adhesive sheets obtained in the examples and comparative examples were stored under the conditions of -40 ° C or 85 ° C and 85% RH for 72 hours, and then stored at normal pressure, Let stand at 23 ° C and 50% RH for 24 hours. Thereafter, the appearance of the adhesive sheet was visually confirmed, and the exudation property was evaluated based on the following criteria. The results are shown in Table 2. ○: No appearance change due to elution, precipitation, etc. of the adhesive layer ×: Appearance change due to elution, precipitation, etc. of the adhesive layer

[Table 1]

[Table 2]

As can be seen from Table 2, the adhesive sheet obtained in the examples maintains a high total light transmittance while making blue light cut-off excellent, and also has excellent exudation and step followability. [Industrial availability]

The adhesive sheet of the present invention can be applied to, for example, bonding of display body constituent members of an LED display, particularly bonding of a protective panel having a step and a desired display body constituent member.

1‧‧‧ adhesive sheet

11‧‧‧ Adhesive layer

12a, 12b ‧‧‧ peeling sheet

2‧‧‧ Display

21‧‧‧The first display component

22‧‧‧Second display component

3‧‧‧print layer

FIG. 1 is a cross-sectional view of an 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 graph showing the results of measurement of the absorption spectrum of merocyanin pigments used in the examples. FIG. 4 is a graph showing the results of measurement of the absorption spectrum of the copper porphyrin complex used in the examples.

Claims (9)

An adhesive sheet includes an adhesive layer for adhering one display component and another display component, wherein the adhesive layer is composed of an adhesive containing at least a first blue visible light absorber. The first blue visible light absorber has a maximum absorption wavelength between 420 and 500 nm, and the full width at half maximum of the maximum absorption wavelength is 40 nm or more and 200 nm or less. The adhesive sheet according to item 1 of the scope of patent application, wherein the first blue visible light absorber is composed of a merocyanin pigment. The adhesive sheet according to item 1 or 2 of the patent application scope, wherein the adhesive contains a second blue visible light absorbent, and the maximum absorption wavelength of the second blue visible light absorbent is higher than that of the first blue visible light absorbent. The lower wavelength side has a maximum absorption wavelength, and the full width at half maximum of the maximum absorption wavelength is 2 nm or more and less than 40 nm. The pressure-sensitive adhesive sheet according to item 3 of the scope of patent application, wherein the aforementioned second blue visible light absorber is composed of a copper porphyrin complex. The adhesive sheet according to any one of claims 1 to 4, wherein the aforementioned adhesive is an acrylic adhesive. The pressure-sensitive adhesive sheet according to any one of claims 1 to 5, including: two release sheets; and the pressure-sensitive adhesive that is held between the two release sheets in contact with the release surfaces of the two release sheets. Floor. The adhesive sheet according to any one of claims 1 to 6, wherein the total light transmittance of the aforementioned adhesive layer is 80% or more. The pressure-sensitive adhesive sheet according to any one of claims 1 to 7, wherein the content of the first blue visible light absorber in the pressure-sensitive adhesive layer is X mass%, and when the thickness of the pressure-sensitive adhesive is Z μm, These satisfy the following formula (I): 0.1 ≦ X × Z ≦ 15… (I). A display body includes: one display body component; another display body component; and an adhesive layer that adheres the one display body component and the other display body component to each other, and is characterized in that: the aforementioned adhesive The layer is an adhesive layer of the adhesive sheet according to any one of claims 1 to 8 of the scope of patent application.