WO2018173979A1 - Pressure-sensitive adhesive composition and pressure-sensitive adhesive sheet - Google Patents

Abstract

A pressure-sensitive adhesive composition which comprises a pressure-sensitive adhesive and an ultraviolet absorber having the structure –S- and/or the structure –SO2- in the molecule; and a pressure-sensitive adhesive sheet including a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition.

Description

Adhesive composition and adhesive sheet

This disclosure relates to an adhesive composition and an adhesive sheet.

It is known that blue light (for example, light in a wavelength region of 380 nm to 500 nm) emitted from a display such as an image display device or a small terminal equipped with a touch panel causes eye strain. Further, ultraviolet rays (for example, light in a wavelength region of 300 nm to 400 nm) can cause sunburn and light degradation of humans and things.
Therefore, in recent years, attempts have been made to impart a function of blocking ultraviolet rays and / or blue light in display sheets and window films.

As a method for imparting a function of blocking ultraviolet rays and blue light to a display sheet and a window film, for example, a method of containing an ultraviolet absorber in an adhesive layer formed on a display sheet or the like is known.
For example, Japanese Patent Application Laid-Open No. 2016-130276 discloses a screen protection film having a base material and a pressure-sensitive adhesive layer provided on the base material as a film having excellent ultraviolet absorbing ability, A hard coat layer is provided on the surface opposite to the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer contains an acrylic copolymer and a triazine ultraviolet absorber, and the acrylic copolymer is methyl. The acrylate monomer unit is contained in an amount of 1 to 20% by mass based on the solid content of the acrylic copolymer, and the pressure-sensitive adhesive layer contains the triazine-based ultraviolet absorber in 100 parts by mass of the acrylic copolymer. 10 to 20 parts by mass, using a image clarity measuring device in accordance with JIS K7374: 2007, and placing it on the sample table with the adhesive layer of the screen protection film facing the light source, A screen protection film having a image clarity of 80 to 100% measured at a base angle of 45 degrees, a transmission mode, and a comb width of 0.125 mm is known (see, for example, JP-A-2016-130276).
In addition, as a film containing an ultraviolet absorber in the adhesive layer, at least one hindered phenolic antioxidant selected from the group consisting of an adhesive, an ultraviolet absorber, a triazine skeleton, a thio skeleton, and a cresol skeleton There is known a pressure-sensitive adhesive film having a pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive composition comprising (see, for example, JP-A-2014-193939).

By the way, the ultraviolet absorber is generally a compound having a cyclic skeleton.
However, since the compound having a cyclic skeleton has high rigidity, in the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition containing the ultraviolet absorber, the cohesive energy may increase and the pressure-sensitive adhesive force may decrease. In general, since the adhesive sheet is required to have excellent adhesive strength, it is not desirable that the adhesive strength of the adhesive layer is reduced by the ultraviolet absorber.

One embodiment of the present invention provides a pressure-sensitive adhesive composition that has a function of blocking ultraviolet light and blue light, is capable of forming a pressure-sensitive adhesive layer that has an excellent pressure-sensitive adhesive force, and is capable of forming a pressure-sensitive adhesive layer. About that.
Another embodiment of this invention is related with providing the adhesive sheet which has an adhesive layer containing the said adhesive composition.

Means for solving the above problems include the following aspects.
<1> A pressure-sensitive adhesive composition comprising a pressure-sensitive adhesive and an ultraviolet absorber having at least one of —S— and —SO ₂ — in the molecule.
<2> The pressure-sensitive adhesive composition according to <1>, wherein the ultraviolet absorber has a cyclic structure in the molecule.
<3> The pressure-sensitive adhesive composition according to <1> or <2>, wherein the ultraviolet absorber has a cyclic structure of at least one of a benzene ring and a 3,5-pyrazolidinedione ring in the molecule.
<4> Any one of <1> to <3>, wherein the ultraviolet absorber includes at least one compound selected from the compound represented by the following formula (1) and the compound represented by the formula (2): The adhesive composition as described in one.

 

In Formula (1), X ¹ and X ² each independently represent an oxygen atom, a sulfur atom, or NR ¹⁷ , and at least one of X ¹ and X ² represents a sulfur atom. Here, R ¹⁷ represents a hydrogen atom or a monovalent substituent. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , and R ¹⁶ are each independently a hydrogen atom, a hydroxy group, an alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, or a carbon number. Represents an acyloxy group having 2 to 30 carbon atoms or a carbamoyloxy group having 1 to 30 carbon atoms.
In formula (2), R ²¹ , R ²² , and R ²³ are each independently a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, or an acyloxy group having 2 to 30 carbon atoms. Or a carbamoyloxy group having 1 to 30 carbon atoms.

<5> At least one of R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , and R ^{16 in} the formula (1) represents a linear alkyl group having 4 to 12 carbon atoms, according to <4>. Adhesive composition.
<6> The pressure-sensitive adhesive composition according to <4> or <5>, wherein at least one of R ²¹ , R ²² , and R ²³ in formula (2) represents a linear alkyl group having 4 to 12 carbon atoms.
<7> Any of <1> to <6>, wherein the ultraviolet absorber includes at least one compound selected from the group consisting of Compound 1, Compound 2, Compound 3, and Compound 5 represented by the following structural formula: The pressure-sensitive adhesive composition according to any one of the above.

 

<8> The pressure-sensitive adhesive composition according to any one of <1> to <3>, wherein the ultraviolet absorber includes a compound 4 represented by the following structural formula.

 

<9> The content of the ultraviolet absorber is any one of <1> to <8>, which is 0.5% by mass or more and 10% by mass or less with respect to the total solid content of the pressure-sensitive adhesive composition. Adhesive composition.
<10> The pressure-sensitive adhesive according to any one of <1> to <9>, wherein the content of the ultraviolet absorber is 1% by mass to 5% by mass with respect to the total solid content of the pressure-sensitive adhesive composition. Agent composition.

<11> A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition according to any one of <1> to <10>.
<12> The pressure-sensitive adhesive sheet according to <11>, which is used as a display sheet.
<13> The pressure-sensitive adhesive sheet according to <11>, which is used as a window film.

According to one embodiment of the present invention, there is provided a pressure-sensitive adhesive composition that has a function of blocking ultraviolet light and blue light, is capable of forming a pressure-sensitive adhesive layer having an excellent pressure-sensitive adhesive force, with a decrease in the pressure-sensitive adhesive force caused by an ultraviolet absorber. Provided.
According to another embodiment of the present invention, a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition is provided.

Hereinafter, examples of the pressure-sensitive adhesive composition and the pressure-sensitive adhesive sheet to which the present invention is applied will be described. However, the present invention is not limited to the following embodiment, and can be implemented with appropriate modifications within the scope of the object of the embodiment of the present invention.

In the present disclosure, a numerical range indicated by using “to” means a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.
In a numerical range described in stages in the present disclosure, an upper limit value or a lower limit value described in a numerical range may be replaced with an upper limit value or a lower limit value in another numerical range. Further, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value described in a certain numerical range may be replaced with the values shown in the examples.
In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment.
In the present disclosure, the content or content rate of each component means the total content or content rate of the plurality of types of substances unless there is a specific case when there are a plurality of types of substances corresponding to the respective components.

In the present disclosure, “ultraviolet light” means light in the wavelength region of 300 nm to 400 nm.
In the present disclosure, “blue light” means light in the wavelength region of 380 nm to 500 nm.

In the present disclosure, “blocking ultraviolet rays” includes not only completely blocking ultraviolet rays but also blocking at least part of ultraviolet rays and reducing the transmittance of ultraviolet rays through an adhesive layer. To do. The same applies to “blocking of blue light”.

[Adhesive composition]
The pressure-sensitive adhesive composition of the present disclosure includes a pressure-sensitive adhesive and an ultraviolet absorber having at least one of —S— and —SO ₂ — in the molecule (hereinafter also referred to as “specific ultraviolet absorber”). Including.
According to the pressure-sensitive adhesive composition of the present disclosure, a pressure-sensitive adhesive layer that has an ultraviolet and blue light blocking function, suppresses a decrease in the pressure-sensitive adhesive force due to the ultraviolet absorber, and has an excellent pressure-sensitive adhesive force can be formed.
The reason why the pressure-sensitive adhesive composition of the present disclosure can exhibit such an effect is not clear, but the present inventor presumes as follows.

As a method for imparting an ultraviolet and / or blue light blocking function to a display sheet, window film, etc., for example, there is a method of containing an ultraviolet absorber in an adhesive layer formed on the display sheet. However, in general, an ultraviolet absorber is a compound having a cyclic skeleton, and therefore has high rigidity. In an adhesive layer formed of an adhesive composition containing an ultraviolet absorber, cohesive energy increases and adhesive strength decreases. There is a case.

On the other hand, the pressure-sensitive adhesive composition of the present disclosure includes a pressure-sensitive adhesive and an ultraviolet absorber having a structure of at least one of —S— and —SO ₂ — in the molecule (that is, a specific ultraviolet absorber). As a result, the sulfur atom derived from the —S— structure and / or —SO ₂ — structure interacts with the polar group present on the surface of the adherend, so that the adhesive strength of the adhesive layer is not improved. I guess that. That is, the pressure-sensitive adhesive composition of the present disclosure includes a pressure-sensitive adhesive and a specific ultraviolet absorber, so that when the pressure-sensitive adhesive layer is formed as a pressure-sensitive adhesive layer, the pressure-sensitive adhesive force is not lowered, but rather improved, and ultraviolet and blue light It is also possible to provide a blocking function.

With respect to the pressure-sensitive adhesive composition of the present disclosure, the screen protective film described in JP-A-2016-130276 and the pressure-sensitive adhesive film described in JP-A-2014-193939 contain an ultraviolet absorber in the pressure-sensitive adhesive layer. Is not an ultraviolet absorber having a —S— structure and / or a —SO ₂ — structure in the molecule. Therefore, it is considered that the screen protective film described in Japanese Patent Application Laid-Open No. 2016-130276 and the adhesive film described in Japanese Patent Application Laid-Open No. 2014-193939 have a decrease in adhesive force due to containing an ultraviolet absorber.
In addition, Japanese Patent Application Laid-Open No. 2016-130276 and Japanese Patent Application Laid-Open No. 2014-193939 do not pay any attention to the influence of the ultraviolet absorber on the adhesive force of the adhesive layer.

Note that the above estimation does not limit the effect of the embodiment of the present invention and is described as an example.

Hereinafter, each component in the pressure-sensitive adhesive composition of the present disclosure will be described in detail.

<Adhesive>
The pressure-sensitive adhesive composition of the present disclosure includes a pressure-sensitive adhesive.
In the pressure-sensitive adhesive composition of the present disclosure, the pressure-sensitive adhesive can contribute to the expression of the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition.
The pressure-sensitive adhesive contained in the pressure-sensitive adhesive composition of the present disclosure is not particularly limited.
The form of the pressure-sensitive adhesive may be a solvent-based pressure-sensitive adhesive, a solventless pressure-sensitive adhesive, a water-dispersed pressure-sensitive adhesive, or a solid pressure-sensitive adhesive.
Examples of the pressure-sensitive adhesive include acrylic pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, and rubber-based pressure-sensitive adhesives.

A commercial item can be used as an adhesive.
Examples of commercially available acrylic adhesives include ARONTAC (registered trademark, the same shall apply hereinafter) HV-C3050, ARONTAC HV-C9500, ARONTAC HV-C9506, ARONTAC HV-C3006, ARONTAC HV-C6320 from Toagosei Co., Ltd. Arontack HV-C5166, Arontack RP-275, Arontack S-1601, Arontack S-1616, Arontack S-3403, Arontack S-1511 modified; Etec's Aquatran (registered trademark, the same shall apply hereinafter) EX202 (A ), Aquatran EX202 (B), Aquatran EX202 (D), N801-A, N730-A; Cybinol (registered trademark, the same shall apply hereinafter) of Seiden Chemical Co., Ltd. AT-193, AT-D40, AT-D50N , AT- 45, AT-D37, AT-D54N, AT-191HS, AT-191, AT-260NT, AT-527, AT-27, AT-1202, AT-1205, AT-21A, AT-290; Nippon Zeon Co., Ltd. ) Nipol (registered trademark, the same shall apply hereinafter) LX 811H, Nipol LX 851E, Nipol LX 857X2, Nipol LX 874, Nipol SX1706A and the like.

Examples of commercially available urethane-based pressure-sensitive adhesives include Toyochem Co., Ltd.'s olivine (registered trademark, hereinafter the same) SP-205, olivine SH-109, olivine SH-101, olivine SH-101M, and the like.
Examples of commercially available silicone pressure-sensitive adhesives include SD4584, SD4585, SD4560, SD4570, SD4580, and SD4587 from Toray Dow Corning Co., Ltd.
Examples of commercially available rubber-based pressure-sensitive adhesives include Nipol LX430, Nipol KX415, Nipol SX1105A manufactured by Nippon Zeon Co., Ltd., and Oribain BPS5079-1 manufactured by Toyochem Co., Ltd.

The pressure-sensitive adhesive composition of the present disclosure may contain only one type of pressure-sensitive adhesive, or may contain two or more types.

The content rate of the solid content of the pressure-sensitive adhesive in the pressure-sensitive adhesive composition of the present disclosure is not particularly limited. % Or less, 60 mass% or more and 98 mass% or less are more preferable, and 70 mass% or more and 97 mass% or less are still more preferable.
In addition, the “solid content of the pressure-sensitive adhesive” in the present disclosure means a residue obtained by removing the solvent and water from the components constituting the pressure-sensitive adhesive. Moreover, the “total solid content of the pressure-sensitive adhesive composition” means the total amount of the residue obtained by removing the solvent and water from the components constituting the pressure-sensitive adhesive composition.

<Ultraviolet absorber>
The pressure-sensitive adhesive composition of the present disclosure includes an ultraviolet absorber having at least one of —S— and —SO ₂ — in the molecule (that is, a specific ultraviolet absorber).
In the pressure-sensitive adhesive composition of the present disclosure, the specific ultraviolet light absorber can contribute not only to imparting ultraviolet and blue light blocking functions to the pressure-sensitive adhesive layer, but also to improving the pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer.

There is no restriction | limiting in particular as a specific ultraviolet absorber.
The specific ultraviolet absorber may have only the —S— structure in the molecule, may have only the —SO ₂ — structure, and has both the —S— structure and the —SO ₂ — structure. You may have.
The specific ultraviolet absorber preferably has a cyclic structure in the molecule from the viewpoint that, for example, a more excellent ultraviolet blocking function and blue light blocking function can be imparted to the pressure-sensitive adhesive layer. And at least one cyclic structure selected from 3,5-pyrazolidinedione rings is more preferable.
In addition, the specific ultraviolet absorber can impart, for example, a more excellent ultraviolet blocking function and blue light blocking function to the adhesive layer, and can further improve the adhesive strength of the adhesive layer. From the viewpoint, it is preferable to include at least one compound selected from the compound represented by the following formula (1) and the compound represented by the formula (2).

 

X ¹ and X ² in Formula (1) each independently represent an oxygen atom, a sulfur atom, or NR ¹⁷ , and at least one of X ¹ and X ² represents a sulfur atom, from the viewpoint of improving heat resistance, It is preferable that both X ¹ and X ² represent a sulfur atom.
R ¹⁷ represents a hydrogen atom or a monovalent substituent, and preferably represents a hydrogen atom.
The monovalent substituent represented by R ¹⁷ is preferably an alkyl group, an alkoxy group, an acyloxy group, or a carbamoyloxy group.

R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , and R ¹⁶ in formula (1) are each independently a hydrogen atom, a hydroxy group, an alkyl group having 1 to 30 carbon atoms, or an alkyl group having 1 to 30 carbon atoms. An alkoxy group, an acyloxy group having 2 to 30 carbon atoms, or a carbamoyloxy group having 1 to 30 carbon atoms is represented.

The alkyl group represented by R ¹¹ to R ¹⁶ may further have a monovalent substituent, and may be linear, branched or cyclic.
The alkyl group has 1 to 30 carbon atoms, preferably 4 to 12 carbon atoms, and more preferably 4 to 8 carbon atoms. Note that these carbon numbers do not include the carbon number of the substituent when the alkyl group further has a substituent. The substituent will be described later.
Examples of the alkyl group having 1 to 30 carbon atoms include methyl group, ethyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, n-octyl group, i-octyl group, 2 -Ethylhexyl group, n-nonyl group, i-nonyl group, n-decyl group, n-dodecyl group, stearyl group, lauryl group, cyclohexyl group and the like.

The alkoxy group having 1 to 30 carbon atoms represented by R ¹¹ to R ¹⁶ is represented as —OR ^A1 (R ^A1 is an alkyl group), and R ^A1 has the same meaning as the alkyl group represented by R ¹¹ to R ^16. It is.
Examples of the alkoxy group having 1 to 30 carbon atoms include methoxy group, ethoxy group, propoxy group, n-octyloxy group, methoxyethoxy group, hydroxyethoxy group, 3-carboxypropoxy group and the like.

The acyloxy group having 2 to 30 carbon atoms represented by R ¹¹ to R ¹⁶ may further have a monovalent substituent.
The acyloxy group has 2 to 30 carbon atoms, preferably 3 to 12, more preferably 4 to 10, still more preferably 4 to 8. These carbon numbers do not include the carbon number of the substituent when the acyloxy group further has a substituent.
Examples of the acyloxy group having 2 to 30 carbon atoms include 2-ethylhexanoyloxy group, n-octanoyloxy group, formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxy group A phenylcarbonyloxy group etc. are mentioned.

The carbamoyloxy group having 1 to 30 carbon atoms represented by R ¹¹ to R ¹⁶ may further have a monovalent substituent.
The carbamoyloxy group has 1 to 30 carbon atoms, preferably 4 to 10 carbon atoms. These carbon numbers do not include the carbon number of the substituent when the carbamoyloxy group further has a substituent.
Examples of the carbamoyloxy group having 1 to 30 carbon atoms include N-methylcarbamoyloxy group, N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di- Examples thereof include an n-octylaminocarbonyloxy group and a Nn-octylcarbamoyloxy group.

For example, from the viewpoint that the adhesive strength of the formed pressure-sensitive adhesive layer can be further improved, at least one of R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , and R ¹⁶ in formula (1). One preferably represents a linear alkyl group having 4 to 12 carbon atoms.
When at least one of R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , and R ¹⁶ in Formula (1) is a linear alkyl group having 4 to 12 carbon atoms, the structure of the ultraviolet absorber is flexible. Since a part arises, the tenacity of the adhesive layer formed improves and adhesive force increases more.

As an aspect of the compound represented by the formula (1), both X ¹ and X ² are sulfur atoms, R ¹¹ is an alkyl group having 1 to 30 carbon atoms, and R ¹² is an alkyl group having 1 to 30 carbon atoms. An embodiment in which the alkyl group is R ¹³ is an acyloxy group having 3 to 12 carbon atoms, R ¹⁴ is a hydrogen atom, R ¹⁵ is a hydrogen atom, and R ¹⁶ is an acyloxy group having 3 to 12 carbon atoms. Preferably, both X ¹ and X ² are sulfur atoms, R ¹¹ is an alkyl group having 4 to 12 carbon atoms, R ¹² is an alkyl group having 4 to 12 carbon atoms, and R ¹³ is 4 to 12 carbon atoms. More preferred is an acyloxy group of 10; R ¹⁴ is a hydrogen atom; R ¹⁵ is a hydrogen atom; and R ¹⁶ is an acyloxy group having 4 to 10 carbon atoms, and both X ¹ and X ² are sulfur. An atom, and R ¹¹ is an alkyl having 4 to 8 carbon atoms. A kill group, R ¹² is an alkyl group having 4 to 8 carbon atoms, R ¹³ is an acyloxy group having 4 to 8 carbon atoms, R ¹⁴ is a hydrogen atom, R ¹⁵ is a hydrogen atom, ^An embodiment in which ¹⁶ is an acyloxy group having 4 to 8 carbon atoms is further preferred.
According to such an aspect, a more excellent ultraviolet blocking function and blue light blocking function can be imparted to the pressure-sensitive adhesive layer. Moreover, the adhesive force of an adhesive layer can be improved more.

R ²¹ , R ²² and R ²³ in formula (2) are each independently a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, an acyloxy group having 2 to 30 carbon atoms, Alternatively, it represents a carbamoyloxy group having 1 to 30 carbon atoms.

The alkyl group represented by R ²¹ to R ²³ may further have a monovalent substituent, and may be linear, branched or cyclic.
The alkyl group has 1 to 30 carbon atoms, and preferably 1 to 12 carbon atoms. Note that these carbon numbers do not include the carbon number of the substituent when the alkyl group further has a substituent.
Examples of the alkyl group having 1 to 30 carbon atoms include methyl group, ethyl group, n-butyl group, i-butyl group, s-butyl group, t-butyl group, n-octyl group, i-octyl group, 2 -Ethylhexyl group, n-nonyl group, i-nonyl group, n-decyl group, n-dodecyl group, stearyl group, lauryl group, cyclohexyl group and the like.

The alkoxy group having 1 to 30 carbon atoms represented by R ²¹ to R ²³ is represented as —OR ^A2 (R ^A2 is an alkyl group), and R ^A2 has the same meaning as the alkyl group represented by R ²¹ to R ^23. It is.
Examples of the alkoxy group having 1 to 30 carbon atoms include methoxy group, ethoxy group, propoxy group, n-octyloxy group, methoxyethoxy group, hydroxyethoxy group, 3-carboxypropoxy group and the like.

The acyloxy group having 2 to 30 carbon atoms represented by R ²¹ to R ²³ may further have a monovalent substituent.
The acyloxy group has 2 to 30 carbon atoms, preferably 4 to 10 carbon atoms. These carbon numbers do not include the carbon number of the substituent when the acyloxy group further has a substituent.
Examples of the acyloxy group having 2 to 30 carbon atoms include 2-ethylhexanoyloxy group, n-octanoyloxy group, formyloxy group, acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxy group A phenylcarbonyloxy group etc. are mentioned.

The carbamoyloxy group having 1 to 30 carbon atoms represented by R ²¹ to R ²³ may further have a monovalent substituent.
The carbamoyloxy group has 1 to 30 carbon atoms, preferably 4 to 10 carbon atoms. These carbon numbers do not include the carbon number of the substituent when the carbamoyloxy group further has a substituent.
Examples of the carbamoyloxy group having 1 to 30 carbon atoms include N-methylcarbamoyloxy group, N, N-dimethylcarbamoyloxy group, N, N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di- Examples thereof include an n-octylaminocarbonyloxy group and a Nn-octylcarbamoyloxy group.

For example, from the viewpoint that the adhesive strength of the formed pressure-sensitive adhesive layer can be further improved, at least one of R ²¹ , R ²² , and R ²³ in Formula (2) has 4 to 12 carbon atoms. It preferably represents a linear alkyl group, and more preferably represents a linear alkyl group having 8 to 12 carbon atoms.
When at least one of R ²¹ , R ²² , and R ²³ in formula (2) is a linear alkyl group having 4 to 12 carbon atoms, a flexible portion is formed in the structure of the ultraviolet absorber, and thus the formed adhesive The tenacity of the agent layer is improved and the adhesive strength is further increased.

As an embodiment of the compound represented by the formula (2), an embodiment in which R ²¹ is an alkyl group, R ²² is an alkyl group, and R ²³ is an alkyl group, and R ²¹ has 1 to 4 carbon atoms. More preferred is an alkyl group, R ²² is an alkyl group having 1 to 4 carbon atoms, R ²³ is an alkyl group having 4 to 12 carbon atoms, and R ²¹ is an alkyl group having 1 to 4 carbon atoms. More preferably, R ²² is an alkyl group having 1 to 4 carbon atoms, and R ²³ is an alkyl group having 8 to 12 carbon atoms.
According to such an aspect, a more excellent ultraviolet blocking function and blue light blocking function can be imparted to the pressure-sensitive adhesive layer. Moreover, the adhesive force of an adhesive layer can be improved more.

The substituent that the alkyl group, acyloxy group, and carbamoyloxy group in Formula (1) and Formula (2) may have can be arbitrarily selected from the following substituent group.
Substituent group: halogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group, aryloxy group, silyloxy group, heterocyclic oxy group, acyloxy group, carbamoyl Oxy group, alkoxycarbonyloxy group, aryloxycarbonyloxy group, amino group, acylamino group, aminocarbonylamino group, alkoxycarbonylamino group, aryloxycarbonylamino group, sulfamoylamino group, alkyl and arylsulfonylamino group, mercapto Group, alkylthio group, arylthio group, heterocyclic thio group, sulfamoyl group, sulfo group, alkyl and arylsulfinyl group, alkyl and arylsulfonyl group, acyl group, aryloxycarbo Group, an alkoxycarbonyl group, a carbamoyl group, an aryl or heterocyclic azo group, an imido group, a phosphino group, phosphinyl group, phosphinyloxy group, phosphinylamino group, a silyl group.

Specific examples of the specific ultraviolet absorber are shown below. However, the specific ultraviolet absorber is not limited to these compounds.
The following compound 1, compound 2, and compound 5 are specific examples of the compound represented by formula (1), and the following compound 3 and compound 6 are specific examples of the compound represented by formula (2). It is an example.

 

For example, from the viewpoint that the adhesive force of the pressure-sensitive adhesive layer can be further improved and an excellent ultraviolet blocking function can be imparted to the pressure-sensitive adhesive layer, among the above specific examples, as the specific ultraviolet light absorber Preferably contains at least one compound selected from the group consisting of Compound 1, Compound 2, Compound 3, and Compound 5.
Since all of Compound 1, Compound 2, Compound 3, and Compound 5 have a linear alkyl group having 4 or more carbon atoms, a flexible portion is generated in the structure. Thereby, in the adhesive layer formed of the adhesive composition containing at least one compound selected from the group consisting of Compound 1, Compound 2, Compound 3, and Compound 5, a linear alkyl group having 4 or more carbon atoms is added. Compared with the pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition that does not contain the specific ultraviolet absorber, the tenacity is improved, and thus the pressure-sensitive adhesive strength is further increased.
In addition, when the specific ultraviolet absorber contained in the pressure-sensitive adhesive composition of the present disclosure is at least one compound selected from the group consisting of Compound 1, Compound 2, Compound 3, and Compound 5, The yellowishness of the pressure-sensitive adhesive layer that may be caused is further suppressed.

For example, from the viewpoint of being able to further improve the adhesive strength of the pressure-sensitive adhesive layer and imparting an excellent ultraviolet blocking function and blue light blocking function to the pressure-sensitive adhesive layer, among the above specific examples, As the specific ultraviolet absorber, compound 4 is preferably included.
Since compound 4 has absorption in the region on the long wavelength side due to its skeletal structure, an excellent blue light blocking function can be imparted to the pressure-sensitive adhesive layer.

A commercial item can be used as a specific ultraviolet absorber.
Examples of commercially available products of specific ultraviolet absorbers include Tinuvin (registered trademark) PS, 99-2, 326, 384-2, 900, 928, 1130, 400, 405, 460, 477, 479, etc., manufactured by BASF Japan. Can be mentioned.

The pressure-sensitive adhesive composition of the present disclosure may contain only one type of specific ultraviolet absorber, or may contain two or more types.

Although the content rate of the specific ultraviolet absorber in the adhesive composition of this indication is not restrict | limited in particular, For example, it is 0.5 mass% or more and 10 mass% or less with respect to the total solid of an adhesive composition. Is preferably 1% by mass or more and 5% by mass or less, and more preferably 3% by mass or more and 5% by mass or less.
When the content of the specific ultraviolet absorber in the pressure-sensitive adhesive composition of the present disclosure is 0.5% by mass or more with respect to the total solid content of the pressure-sensitive adhesive composition, more excellent ultraviolet light with respect to the pressure-sensitive adhesive layer A blocking function and a blue light blocking function can be provided. Moreover, the adhesive force of an adhesive layer can be improved more.
Moreover, the adhesive force of the adhesive layer by an ultraviolet absorber as the content rate of the specific ultraviolet absorber in the adhesive composition of this indication is 10 mass% or less with respect to the total solid of an adhesive composition. Is further suppressed. Moreover, yellowishness that can be caused by the ultraviolet absorber is further suppressed.

The ratio of the solid content of the specific ultraviolet absorber to the solid content of the adhesive in the pressure-sensitive adhesive composition of the present disclosure (hereinafter also referred to as “solid content of the specific ultraviolet absorber / solid content of the adhesive”) is, for example, 1 The mass% is preferably 20% by mass or less, more preferably 2% by mass or more and 10% by mass or less, and further preferably 4% by mass or more and 10% by mass or less.
When the solid content of the specific ultraviolet absorber / solid content of the pressure-sensitive adhesive in the pressure-sensitive adhesive composition of the present disclosure is 1% by mass or more, the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer can be further improved.
In addition, when the solid content of the specific ultraviolet absorber / the solid content of the adhesive in the pressure-sensitive adhesive composition of the present disclosure is 20% by mass or less, a decrease in the adhesive strength of the pressure-sensitive adhesive layer due to the ultraviolet absorber is further suppressed. The

<Other ingredients>
The pressure-sensitive adhesive composition of the present disclosure may contain components other than the components described above (so-called other components) as necessary within a range not impairing the effects of the present disclosure.
Examples of other components include a solvent, an antioxidant, a crosslinking agent, a surfactant, a filler, a colorant, a light stabilizer, a thickener, and a polymerization initiator.

(solvent)
The pressure-sensitive adhesive composition of the present disclosure preferably contains a solvent from the viewpoint of improving applicability.
The “solvent” used herein includes a solvent for dilution used for dilution and a solvent contained in a commercially available adhesive.
Solvents include hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, methylcyclohexane and other hydrocarbons; dichloromethane, trichloroethane, trichloroethylene, tetrachloroethylene, dichloropropane and other halogenated hydrocarbons; methanol, ethanol, propanol, Alcohols such as isopropyl alcohol, butanol, isobutyl alcohol, diacetone alcohol; ethers such as diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, isophorone, cyclohexanone; methyl acetate, acetic acid Esters such as ethyl, butyl acetate, isobutyl acetate, amyl acetate, ethyl acetate; ethylene Recall monomethyl ether, ethylene glycol monoethyl ether, polyols such as propylene glycol monomethyl ether acetate; the organic solvent and derivatives thereof.

When the pressure-sensitive adhesive composition of the present disclosure contains a solvent, the content of the solvent in the pressure-sensitive adhesive composition is, for example, from 30% by mass to 80% by mass with respect to the total amount of the pressure-sensitive adhesive composition from the viewpoint of improving coatability. %, More preferably 40% to 70% by weight, and still more preferably 40% to 60% by weight.

[Adhesive sheet]
The pressure-sensitive adhesive sheet of the present disclosure has a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition of the present disclosure described above.
Since the pressure-sensitive adhesive sheet of the present disclosure has a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition of the present disclosure, the pressure-sensitive adhesive sheet has an excellent ultraviolet and blue light blocking function.
In addition, the pressure-sensitive adhesive sheet of the present disclosure has an excellent pressure-sensitive adhesive force with a decrease in pressure-sensitive adhesive force caused by the ultraviolet absorber.

The pressure-sensitive adhesive sheet of the present disclosure may be a pressure-sensitive adhesive sheet having no base material (non-base material type), or a pressure-sensitive adhesive sheet having a base material (substrate-type).

The substrate is not particularly limited, and examples thereof include resin films such as polyethylene terephthalate (PET), polyethylene, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, and acrylic resin.
The substrate is preferably transparent.
The thickness of the substrate is not particularly limited, and is preferably 15 μm to 1000 μm from the viewpoint of durability, for example.

The exposed surface of the pressure-sensitive adhesive layer may be protected by a release film.
A release film will not be restrict | limited especially if it can peel easily from an adhesive layer.
As a peeling film, the resin film (for example, PET film) by which the easy peeling process by the peeling processing agent (for example, silicone) was given to the at least single side | surface is mentioned, for example.
The release film protects the surface of the pressure-sensitive adhesive layer until the pressure-sensitive adhesive sheet is used, and is peeled off during use.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, and can be appropriately set according to the use, required performance, and the like.
For example, from the viewpoint of the productivity of the pressure-sensitive adhesive sheet, the thickness of the pressure-sensitive adhesive layer is preferably set in the range of 10 μm to 50 μm.

The pressure-sensitive adhesive sheet of the present disclosure has an excellent blue light blocking function and has a superior pressure-sensitive adhesive strength reduction due to the inclusion of an ultraviolet absorber. Therefore, the pressure-sensitive adhesive sheet is suitably used, for example, as a display sheet. be able to.
When using the adhesive sheet of this indication as a display sheet, the adhesive sheet of this indication may have functional layers, such as a hard-coat layer, for example.
Moreover, since the adhesive sheet of this indication is further excellent in the blocking | blocking function of an ultraviolet-ray, it can be used suitably as a window film, for example.
When using the adhesive sheet of this indication as a window film, the adhesive sheet of this indication may have functional layers, such as a heat insulation layer, for example.

By using the pressure-sensitive adhesive sheet of the present disclosure for application to an adherend having a polar group, the effect of improving the pressure-sensitive adhesive force is more remarkably exhibited.
Examples of the adherend having a polar group include glass, metal, metal oxide, inorganic oxide, epoxy resin, urethane resin, imide resin, and amide resin.
In the pressure-sensitive adhesive sheet of the present disclosure, the polar group in which the sulfur atom of the ultraviolet absorber having a —S— structure and / or —SO ₂ — structure in the molecule (that is, the specific ultraviolet absorber) is present on the surface of the adherend is present. It is presumed that the adhesive strength of the pressure-sensitive adhesive layer may be improved because of the interaction with the pressure-sensitive adhesive layer.

<Method for producing adhesive sheet>
The method for producing the pressure-sensitive adhesive sheet of the present disclosure is not particularly limited as long as the pressure-sensitive adhesive sheet of the present disclosure described above can be produced.
The pressure-sensitive adhesive sheet of the present disclosure can be produced, for example, by the following method.
For example, in the case of a non-base material type pressure-sensitive adhesive sheet, the pressure-sensitive adhesive sheet of the present disclosure is formed by applying the pressure-sensitive adhesive composition to the release-treated surface of the release film and forming a coating film of the pressure-sensitive adhesive composition, and then forming the coating. An adhesive layer can be formed and produced by drying the film. If necessary, another release film may be overlaid on the formed pressure-sensitive adhesive layer so that the release treatment surface is in contact therewith.
For example, in the case of a substrate-type pressure-sensitive adhesive sheet, the pressure-sensitive adhesive sheet of the present disclosure is obtained by applying a pressure-sensitive adhesive composition to one side of a base material, forming a pressure-sensitive adhesive composition coating film, and then forming the formed coating film. The pressure-sensitive adhesive layer can be formed and produced by drying. If necessary, a release film may be overlaid on the formed pressure-sensitive adhesive layer so that the release treatment surface is in contact therewith.

The method of applying the pressure-sensitive adhesive composition to the release film or the substrate is not particularly limited, and examples thereof include a blade coater, a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, and a spray. The well-known coating method using a coater etc. is mentioned.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

[Preparation of pressure-sensitive adhesive composition]
<Example 1 to Example 39>
By stirring and mixing the components constituting the pressure-sensitive adhesive composition described in Tables 1 to 3 below using a stirrer equipped with a stirring blade [Three-One Motor (registered trademark), Shinto Kagaku Co., Ltd.] A pressure-sensitive adhesive composition was obtained.

<Comparative Examples 1 to 16>
The components constituting the pressure-sensitive adhesive composition shown in Table 4 below are mixed by stirring using a stirrer provided with a stirring blade [Three-One Motor (registered trademark), Shinto Kagaku Co., Ltd.]. A composition was obtained.

<Reference Example 1 to Reference Example 4>
The components constituting the pressure-sensitive adhesive composition shown in Table 4 below are mixed by stirring using a stirrer provided with a stirring blade [Three-One Motor (registered trademark), Shinto Kagaku Co., Ltd.]. A composition was obtained.

The numerical values described in the column of each component in Tables 1 to 4 indicate the content (unit: part by mass) of the component, and “-” means that the component is not contained. The numerical values of the pressure-sensitive adhesive content in Tables 1 to 4 are solid content conversion values.

Details of each component described in Tables 1 to 4 are as follows.
<Adhesive>
・ Cybinol AT-D45 [trade name, acrylic adhesive, solid content: 50% by mass, Seiden Chemical Co., Ltd.]
・ Olivein SP-205 [trade name, urethane adhesive, solid content: 50 mass%, Toyochem Co., Ltd.]
・ SD 4587 L PSA [trade name, silicone adhesive, solid content: 60% by mass, Toray Dow Corning Co., Ltd.]
・ Olivein BPS5079-1 [trade name, rubber adhesive, solid content: 40 mass%, Toyochem Co., Ltd.]

<Ultraviolet absorber>
Compound 1 to compound 7 (compound 1 to compound 7 described above)
Compound 8 [trade name: Tinuvin 326, triazole ultraviolet absorber, BASF Japan Ltd.]
Compound 9 [trade name: Tinuvin 405, triazine ultraviolet absorber, BASF Japan Ltd.]
Compound 10 [trade name: Tinuvin 477, triazine ultraviolet absorber, BASF Japan Ltd.]
Compound 11 [hydroxymethoxybenzophenone sulfonic acid]
<Solvent>
・ Methyl ethyl ketone (abbreviation: MEK)

The structures of Compound 8 and Compound 9 are shown below.

 

[Preparation of adhesive sheet for evaluation]
Using the pressure-sensitive adhesive composition obtained above, an evaluation pressure-sensitive adhesive sheet was produced as follows. Blade coater on a polyethylene terephthalate (PET) film (trade name: Cosmo Shine (registered trademark) A4300, thickness: 100 μm, Toyobo Co., Ltd.) as a substrate so that the film thickness after drying is 20 μm. A pressure-sensitive adhesive composition was applied to form a coating film of the pressure-sensitive adhesive composition. Next, the formed coating film was dried at 120 ° C. for 120 seconds to obtain an evaluation pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer (thickness: 20 μm) on the substrate.

[Evaluation]
1. Adhesive strength The adhesive strength was measured in accordance with Japanese Industrial Standard JIS Z0237: 2009.
The evaluation pressure-sensitive adhesive sheet obtained above was cut into a size of 0.025 m × 0.1 m to prepare two pressure-sensitive adhesive sheet pieces for pressure-sensitive adhesive strength evaluation.
Of the prepared pressure-sensitive adhesive sheet for evaluating the adhesive strength, one of them is an environment of 23 ° C. and 50% relative humidity using a dedicated rubber roll [product name: tape pressing roll (manual type), Imoto Seisakusho Co., Ltd.] Underneath, the pressure-sensitive adhesive layer was pressed and bonded to a glass plate (thickness: 10 mm) placed on a table with a load of 1 kg to prepare a test piece A.
Further, among the prepared pressure-sensitive adhesive sheet pieces for evaluating the adhesive strength, the other sheet was used at 23 ° C. and relative humidity 50 using a dedicated rubber roll [product name: tape crimping roll (manual type), Imoto Seisakusho Co., Ltd.]. In a% environment, the pressure-sensitive adhesive layer was pressure-bonded and bonded to a SUS (stainless steel) 304 plate (thickness: 10 mm) placed on a table with a load of 1 kg to prepare a test piece B.

Next, with respect to the prepared test piece A and test piece B, the adhesive strength (unit: N / 25 mm) when the adhesive strength evaluation adhesive sheet was peeled 180 ° in the long side (0.1 m) direction from the glass plate and the SUS304 plate, respectively. ), The electric horizontal type digital force gauge stand [Product name: FGS-50XB, Nidec Symposium] with a digital force gauge [Product name: FGP-5, Nidec Symposium] The substrate (that is, PET film) and the pressure-sensitive adhesive layer were combined and sandwiched between jigs, and the measurement was performed under the condition of a peeling rate of 100 mm / min.

Then, the pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition containing the ultraviolet absorber is used to determine how much the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer is changed by the pressure-sensitive adhesive composition containing the ultraviolet absorber. It confirmed by comparing force and the adhesive force of the adhesive layer formed with the adhesive composition which does not contain a ultraviolet absorber.

For example, Example 1, Example 5, Example 9, Example 13, Example 17, Example 21, Example 25, Examples 29 to 39, Comparative Example 1, Comparative Example 5, Comparative Example 9, And the change (unit: N / 25mm) of the adhesive force by the ultraviolet absorber of each adhesive layer formed with the adhesive composition of Comparative Example 13 is the adhesive layer formed with the adhesive composition of Reference Example 1. Was calculated based on the adhesive strength of.
By the pressure-sensitive adhesive composition of Example 2, Example 6, Example 10, Example 14, Example 18, Example 22, Example 26, Comparative Example 2, Comparative Example 6, Comparative Example 10, and Comparative Example 14 The change in the adhesive strength (unit: N / 25 mm) of each formed adhesive layer by the ultraviolet absorber was calculated based on the adhesive strength of the adhesive layer formed by the adhesive composition of Reference Example 2.
According to the pressure-sensitive adhesive composition of Example 3, Example 7, Example 11, Example 15, Example 19, Example 23, Example 27, Comparative Example 3, Comparative Example 7, Comparative Example 11, and Comparative Example 15. The change (unit: N / 25 mm) of the adhesive strength of each formed adhesive layer by the ultraviolet absorber was calculated based on the adhesive strength of the adhesive layer formed by the adhesive composition of Reference Example 3.
According to the pressure-sensitive adhesive compositions of Example 4, Example 8, Example 12, Example 16, Example 20, Example 24, Example 28, Comparative Example 4, Comparative Example 8, Comparative Example 12, and Comparative Example 16. The change (unit: N / 25 mm) of the adhesive strength of each formed adhesive layer by the ultraviolet absorber was calculated based on the adhesive strength of the adhesive layer formed by the adhesive composition of Reference Example 4.

A positive value for the change in adhesive strength means that the adhesive strength of the adhesive layer has been improved by the UV absorber, and a negative value for the change in adhesive strength means that the UV absorption It means that the adhesive strength of the pressure-sensitive adhesive layer was lowered by the agent.
The results are shown in Tables 5-8.

2. Optical characteristics The adhesive sheet for evaluation obtained above was cut into a size of 5 cm x 5 cm to prepare an adhesive sheet piece for optical characteristics evaluation. Using the prepared adhesive sheet piece for evaluating optical properties, the optical properties of the following items were evaluated. The results are shown in Tables 5-8.

(1) Measurement of cut-off wavelength The transmission spectrum of the prepared pressure-sensitive adhesive sheet piece for optical property evaluation was measured using an ultraviolet-visible-near-infrared spectrophotometer [product name: V-670, JASCO Corporation]. Then, when the wavelength of light was changed from the wavelength of 500 nm toward the short wavelength side, the wavelength at which the transmittance first became 95% or less was defined as the “cutoff wavelength”. The longer this cutoff wavelength is on the longer wavelength side, the better the pressure-sensitive adhesive layer is in the blue light blocking function.

(2) Ultraviolet ray blocking function The transmission spectrum of the prepared adhesive sheet piece for optical property evaluation was measured using an ultraviolet-visible near-infrared spectrophotometer [product name: V-670, JASCO Corporation], 300 nm The integral value of the spectral area in the wavelength region of ˜400 nm was determined. And the integral value of the spectrum area in the adhesive sheet (that is, the adhesive sheet piece for optical property evaluation of Examples and Comparative Examples) having an adhesive layer formed of an adhesive composition containing an ultraviolet absorber, From the integral value of the spectrum area in the pressure-sensitive adhesive sheet (that is, the pressure-sensitive adhesive sheet piece for optical property evaluation of the reference example) having a pressure-sensitive adhesive layer formed by a pressure-sensitive adhesive composition not containing the UV, it was decreased by including the ultraviolet absorber. The ratio of the integral value of the spectral area (that is, the ultraviolet blocking rate) was calculated, and the ultraviolet blocking function of the adhesive layer was evaluated. The evaluation criteria are shown below.
In the following evaluation criteria, “S” indicates the most excellent ultraviolet blocking function, and if “S” or “A”, there is no practical problem.

-Evaluation criteria-
S: The ultraviolet blocking rate is 70% or more.
A: The ultraviolet blocking rate is 50% or more and less than 70%.
B: The ultraviolet blocking rate is 30% or more and less than 50%.
C: The ultraviolet blocking rate is less than 30%.

(3) Blue light blocking function For the prepared pressure-sensitive adhesive sheet for evaluating optical properties, the transmission spectrum in the wavelength region of 380 nm to 500 nm was measured with an ultraviolet-visible near-infrared spectrophotometer [product name: V-670, JASCO Corporation )], And the blue light blocking function of the pressure-sensitive adhesive layer was evaluated according to the following evaluation criteria.
The following evaluation criteria indicate that “S” is the most excellent blue light blocking function, and if “S”, “A”, or “B”, there is no practical problem.

-Evaluation criteria-
S: Blue light blocking rate based on ISO 12312-1: 2013 standard is 50% or more.
A: Blue light blocking rate based on ISO 12312-1: 2013 standard is 30% or more and less than 50%.
B: Blue light blocking rate based on ISO 12312-1: 2013 standard is 20% or more and less than 30%.
C: Blue light blocking rate based on ISO 12312-1: 2013 standard is less than 20%.

(4) Color The prepared pressure-sensitive adhesive sheet piece for optical property evaluation was placed on white paper. The pressure-sensitive adhesive sheet piece for optical property evaluation on paper was visually observed, and whether or not the pressure-sensitive adhesive sheet piece for optical property evaluation had a yellowish color was evaluated according to the following evaluation criteria.

-Evaluation criteria-
A: Yellowish and colorless and transparent.
B: Yellowish.

 

 

 

 

As shown in Tables 5 to 8, the pressure-sensitive adhesive compositions of Examples 1 to 39 including pressure-sensitive adhesives and ultraviolet absorbers having at least one of —S— and —SO ₂ — structures in the molecule. The pressure-sensitive adhesive layer formed of the product had a function of blocking ultraviolet rays and blue light, and was excellent in adhesive strength. Further, it is clear that the adhesive layers formed from the adhesive compositions of Examples 1 to 39 are improved in adhesive strength by containing an ultraviolet absorber in comparison with Reference Examples 1 to 4. It became.
On the other hand, a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive compositions of Comparative Examples 1 to 16 containing a pressure-sensitive adhesive and an ultraviolet absorber having neither of the structures of —S— or —SO ₂ — in the molecule Although it has an ultraviolet blocking function, it has been observed that the adhesive strength tends to decrease when it contains an ultraviolet absorber.

[Preparation of adhesive sheet for display sheet]
A PET film (trade name: KB film N10, thickness: 100 μm, Kimoto Co., Ltd.) having a hard coat layer on one side was prepared. On the surface of the PET film opposite to the hard coat layer, the pressure-sensitive adhesive composition of Example 1 was applied using a blade coater so that the film thickness after drying was 20 μm. The coating film was formed. Subsequently, the formed coating film was dried at 120 ° C. for 120 seconds to prepare a pressure-sensitive adhesive sheet (that is, a pressure-sensitive adhesive sheet for display sheet) as a display sheet having a pressure-sensitive adhesive layer having a thickness of 20 μm.
The produced pressure-sensitive adhesive sheet for display sheet had a function of blocking ultraviolet light and blue light, and was excellent in adhesive strength.

[Preparation of adhesive sheet for window film]
A PET film (thickness: 100 μm) having a heat insulating layer containing silver nanowires described in paragraph [0117] of JP-A-2016-33629 was prepared. The pressure-sensitive adhesive composition of Example 1 was applied to the surface of the PET film opposite to the heat insulating layer using a blade coater so that the film thickness after drying was 20 μm. A coating film was formed. Next, the formed coating film was dried at 120 ° C. for 120 seconds to prepare a pressure-sensitive adhesive sheet (that is, a pressure-sensitive adhesive sheet for window film) as a window film having a pressure-sensitive adhesive layer having a thickness of 20 μm.
The produced adhesive sheet for window films had a function of blocking ultraviolet light and blue light, and was excellent in adhesive strength.

The disclosure of Japanese Patent Application No. 2017-055462 filed on March 21, 2017 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards described in this specification are specifically and individually incorporated by reference as if individual documents, patent applications, and technical standards were incorporated by reference. To the extent it is incorporated herein by reference.

Claims (13)

1. With adhesive,
   An ultraviolet absorber having at least one of —S— and —SO ₂ — in the molecule;
   A pressure-sensitive adhesive composition comprising:
2. The pressure-sensitive adhesive composition according to claim 1, wherein the ultraviolet absorber has a cyclic structure in the molecule.
3. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the ultraviolet absorber has a cyclic structure of at least one of a benzene ring and a 3,5-pyrazolidinedione ring in the molecule.
4. The ultraviolet absorber comprises at least one compound selected from the compound represented by the following formula (1) and the compound represented by the formula (2): The pressure-sensitive adhesive composition described.
   

   

   
   
   In Formula (1), X ¹ and X ² each independently represent an oxygen atom, a sulfur atom, or NR ¹⁷ , and at least one of X ¹ and X ² represents a sulfur atom. Here, R ¹⁷ represents a hydrogen atom or a monovalent substituent. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , and R ¹⁶ are each independently a hydrogen atom, a hydroxy group, an alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, or a carbon number. Represents an acyloxy group having 2 to 30 carbon atoms or a carbamoyloxy group having 1 to 30 carbon atoms.
   In formula (2), R ²¹ , R ²² , and R ²³ are each independently a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, or an acyloxy group having 2 to 30 carbon atoms. Or a carbamoyloxy group having 1 to 30 carbon atoms.
5. The pressure-sensitive adhesive according to claim 4, wherein at least one of R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , and R ^{16 in} the formula (1) represents a linear alkyl group having 4 to 12 carbon atoms. Composition.
6. 6. The pressure-sensitive adhesive composition according to claim 4, wherein at least one of R ²¹ , R ²² , and R ²³ in the formula (2) represents a linear alkyl group having 4 to 12 carbon atoms.
7. 7. The ultraviolet absorber includes at least one compound selected from the group consisting of compound 1, compound 2, compound 3, and compound 5 represented by the following structural formula. 2. The pressure-sensitive adhesive composition according to 1.
   

   

   
   
8. The pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the ultraviolet absorber comprises a compound 4 represented by the following structural formula.
   

   

   
   
9. The pressure-sensitive adhesive according to any one of claims 1 to 8, wherein the content of the ultraviolet absorber is 0.5% by mass or more and 10% by mass or less based on the total solid content of the pressure-sensitive adhesive composition. Composition.
10. The pressure-sensitive adhesive composition according to any one of claims 1 to 9, wherein a content of the ultraviolet absorber is 1% by mass or more and 5% by mass or less with respect to a total solid content of the pressure-sensitive adhesive composition. .
11. A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition according to any one of claims 1 to 10.
12. The pressure-sensitive adhesive sheet according to claim 11, which is used as a display sheet.
13. The pressure-sensitive adhesive sheet according to claim 11 used as a window film.