JP2020105454A - Adhesive composition, cured product and surface protective film - Google Patents

Abstract

To provide means that makes it possible to form an adhesive layer that combines the adhesiveness and reworkability at a high level by reducing adhesive force during peeling than adhesive force in an adhesive state, and means capable of improving wettability to an adherent of an adhesive layer by improving die-cutting processability of the adhesive layer and substrate contamination in addition to combining the adhesiveness and the reworkability to reduce a peel electrification voltage of the adhesive layer.SOLUTION: The present invention contains (A) component: an urethane polymer having two or more of hydroxyl groups, (B) component: polyfunctional (meth)acrylate, (C) component: a crosslinking agent, (D) component: crosslinking particles, (E) a photo radical initiator and (F) component: an antistatic agent, in which a content of the (D) component relative to the (A) component 100 pts.mass is 0.01 pts.mass or larger and 10 pts.mass or smaller.SELECTED DRAWING: None

Description

The present invention relates to a pressure-sensitive adhesive composition, a cured product and a surface protective film.

On the surface of various displays such as word processors, computers, mobile phones, and televisions, various optical components such as polarizing plates or equivalent laminates, or various substrates such as electronic substrates, an adhesive layer is usually provided for the purpose of surface protection. The surface protection film which it has is stuck.

The pressure-sensitive adhesive layer is required to have good pressure-sensitive adhesiveness in the bonded state. The term "adhesiveness" refers to a property of having sufficient adhesiveness to an adherend and not causing problems such as peeling and floating. Further, the surface protective film is peeled off from the adherend during the manufacturing process or during use, but if the adhesive strength is excessive, the adherend may be broken or broken during peeling, or the adherend may be peeled off. Adhesive residue may occur on the body. Therefore, the pressure-sensitive adhesive layer is required to have good reworkability (removability) at the time of peeling. The reworkability means a property that the adherend can be easily peeled off without destruction of the adherend or adhesive residue on the adherend.

From the viewpoint of achieving both such adhesiveness and reworkability, a urethane-based adhesive composition has been studied as an adhesive composition.

In Patent Document 1 and Patent Document 2, a pressure-sensitive adhesive layer formed from an adhesive composition containing a hydroxyl group-containing polyurethane, an ionic compound, and a trifunctional isocyanate compound provides the adhesive force and reworkability of an adhesive film. It is disclosed that both of these can be realized.

Patent Document 3 discloses that reworkability can be improved by a pressure-sensitive adhesive layer formed from an adhesive composition containing a urethane urea resin having a hydroxyl group at the terminal, an ionic compound, and a polyfunctional isocyanate. Has been done.

JP, 2007-169377, A JP, 2005-154492, A JP, 2007-238766, A

The pressure-sensitive adhesive layer formed from the urethane-based adhesive composition (pressure-sensitive adhesive composition) of Patent Documents 1 to 3 attempts to achieve both tackiness and reworkability by adjusting the tackiness. However, in this method, both tackiness and reworkability depend on the tackiness of the pressure-sensitive adhesive layer and are in a trade-off relationship. That is, there is a problem in that the tackiness becomes insufficient when trying to obtain sufficient reworkability, and the reworking ability becomes insufficient when trying to obtain sufficient tackiness. In addition, the urethane-based adhesive composition may have problems such as insufficient punching workability and substrate contamination, and a problem of increased peeling electrification voltage. The wettability of the pressure-sensitive adhesive layer to the adherend may be insufficient depending on the type of the urethane-based compound contained in the urethane-based adhesive composition. At this time, air may enter during bonding with the adherend, resulting in a problem of bonding failure.

Therefore, the present invention aims to provide a means capable of forming a pressure-sensitive adhesive layer that is compatible with a high level of adhesiveness and reworkability by reducing the adhesive force at the time of peeling than the adhesive force in an adhesive state. And Further, the present invention, in addition to the compatibility of tackiness and reworkability, improves the punching workability and substrate contamination of the pressure-sensitive adhesive layer, lowers the peeling electrification voltage of the pressure-sensitive adhesive layer, and reduces the coating of the pressure-sensitive adhesive layer. It is an object of the present invention to provide a means capable of achieving high wettability and high transparency with respect to an adhered body.

The above problems of the present invention are solved by the following means.

Component (A): urethane prepolymer having two or more hydroxyl groups,
(B) component: polyfunctional (meth)acrylate,
(C) component: cross-linking agent,
(D) component: crosslinked particles,
(E) component: photo radical initiator, and (F) component: antistatic agent,
Containing
Content of the said (D) component with respect to 100 mass parts of said (A) components is 0.01 mass part or more and 10 mass parts or less, The adhesive composition characterized by the above-mentioned.

According to the present invention, there is provided a means that makes it possible to form an adhesive layer that has both high adhesiveness and reworkability at a high level by reducing the adhesive force at the time of peeling as compared with the adhesive force in the adhesive state. Further, according to the present invention, in addition to compatibility of tackiness and reworkability, the punching processability and substrate contamination of the pressure-sensitive adhesive layer are improved, and the peeling electrification voltage of the pressure-sensitive adhesive layer is lowered, and the pressure-sensitive adhesive layer is A means capable of achieving high wettability and high transparency to an adherend is provided.

It is explanatory drawing explaining the measuring method of the wettability with respect to the to-be-adhered body of the adhesive layer in an Example.

Hereinafter, preferred embodiments of the present invention will be described. Unless otherwise specified, operations and physical properties are measured under the conditions of room temperature (20° C. or higher and 25° C. or lower)/relative humidity 40% RH or higher and 50% RH or lower.

In addition, in this specification, "(meth)acrylate" is a general term for acrylate and methacrylate. Similarly, a compound containing (meth) such as (meth)acrylic acid is a general term for a compound having “meth” in the name and a compound not having “meth”.

Further, in the present specification, “(co)polymer” is a general term for homopolymers and copolymers.

<Adhesive composition>
One form of the present invention is
Component (A): urethane prepolymer having two or more hydroxyl groups,
Component (B): polyfunctional (meth)acrylate,
(C) component: cross-linking agent,
(D) component: reactive surface modifier,
(E) component: photo radical initiator, and (F) component: antistatic agent,
Containing
Content of the said (D) component with respect to 100 mass parts of said (A) components is 0.01 mass part or more and 10 mass parts or less, It is related with the adhesive composition.

The present inventors presume the mechanism by which the above-mentioned configuration solves the problem as follows.

A urethane-based pressure-sensitive adhesive composition generally forms a pressure-sensitive adhesive layer by curing a urethane-based compound contained in the composition and a cross-linking agent such as an isocyanate compound through polymerization and a cross-linking reaction. In the conventional urethane-based pressure-sensitive adhesive composition as disclosed in Patent Documents 1 to 3, the adhesiveness and reworkability can be improved by adjusting the type of the urethane-based compound or the cross-linking agent, the content ratio of these, or the reaction conditions. Trying to control. However, the tackiness and the reworkability are in a trade-off relationship because they both depend on the tackiness of the pressure-sensitive adhesive layer, and it is difficult to achieve both a high level of tackiness and reworkability. It was

On the other hand, the pressure-sensitive adhesive composition according to one aspect of the present invention contains (A) component: a urethane prepolymer having two or more hydroxyl groups and (C) component: a crosslinking agent. The pressure-sensitive adhesive composition according to one aspect of the present invention further contains, in addition to these, a component (B): a polyfunctional (meth)acrylate and a component (E): a photoradical initiator. Therefore, the light irradiation during the rework progresses the photopolymerization and crosslinking reaction of the component (B): polyfunctional (meth)acrylate and the (meth)acrylic (co)polymer derived therefrom. , The adhesive strength of the adhesive is significantly reduced. As a result, the pressure-sensitive adhesive layer composed of the cured product of the pressure-sensitive adhesive composition according to one aspect of the present invention has a very good reworkability while having a good adhesive force before light irradiation. Become. Thus, the pressure-sensitive adhesive composition according to one aspect of the present invention has been made overcoming the technical problem that the adhesiveness in the conventional urethane-based pressure-sensitive adhesive composition and the reworkability have a trade-off relationship. It is a thing. That is, the pressure-sensitive adhesive composition according to one aspect of the present invention, by a completely different design concept from the conventional urethane-based pressure-sensitive adhesive composition, to separately control the pressure-sensitive adhesive force and the pressure during rework. It makes it possible.

The pressure-sensitive adhesive composition according to one aspect of the present invention contains (D) component: crosslinked particles. Here, the component (D) forms irregularities on the surface of the pressure-sensitive adhesive layer. Then, the unevenness is formed on the pressure-sensitive adhesive layer, so that the pressure-sensitive adhesive force is reduced. As a result, the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer before light irradiation is in an appropriate range, and the tackiness is improved. Further, the adhesive strength of the pressure-sensitive adhesive layer at the time of reworking is reduced, and the reworkability of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer is improved.

Furthermore, in the pressure-sensitive adhesive composition according to one aspect of the present invention, the content of the component (D) is within a predetermined range. That is, the content of the component (D) is sufficient to obtain the above effect and is not excessive. Therefore, both the adhesiveness and the reworkability can be achieved while suppressing the deterioration of the wettability and transparency of the adhesive layer to the adherend due to the component (D). Further, since the added amount of the component (D) is not excessive, the component (D) is less likely to fall off, and good punching workability can be obtained. Then, a low peeling withstand voltage can be realized without deteriorating the bleed-out of the component (F), and good substrate contamination can be maintained.

The above mechanism is based on speculation, and its correctness does not affect the technical scope of the present invention.

The pressure-sensitive adhesive composition according to one aspect of the present invention is preferably heat-cured to form a pressure-sensitive adhesive layer. That is, the pressure-sensitive adhesive composition according to one aspect of the present invention is preferably a thermosetting pressure-sensitive adhesive composition. The pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to one aspect of the present invention is composed of a cured product of the pressure-sensitive adhesive composition according to one aspect of the present invention, preferably a thermosetting product. In addition, in this specification, a thermosetting product is a cured product formed by the progress of a crosslinking reaction by heat. The heat-cured product does not necessarily require heating, and includes a cured product cured at room temperature (20° C. or higher and 25° C. or lower).

Further, a preferred embodiment of the present invention relates to a pressure-sensitive adhesive composition in which the pressure-sensitive adhesive strength of the pressure-sensitive adhesive composition is reduced by light irradiation. Here, "the adhesive force of the pressure-sensitive adhesive composition is reduced by light irradiation" means that the adhesive force of the pressure-sensitive adhesive composition itself and a cured product thereof is reduced by the light irradiation. Therefore, the pressure-sensitive adhesive composition exhibits remarkably excellent reworkability by performing light irradiation treatment during rework, while exhibiting extremely good tackiness in a tacky state. Here, the ratio of the adhesive force after the light irradiation to the adhesive force before the light irradiation treatment of the cured product of the adhesive composition, and the adhesive force before and after the light irradiation are the same as those of the adhesive layer and the adhesive film described later. It is preferably in the range of.

Hereinafter, each component constituting the pressure-sensitive adhesive composition according to one aspect of the present invention will be described in detail.

[Component (A): Urethane Prepolymer Having Two or More Hydroxyl Groups]
The pressure-sensitive adhesive composition according to one aspect of the present invention contains (A) component: a urethane prepolymer having two or more hydroxyl groups. The component (A) has a function of imparting tackiness to the pressure-sensitive adhesive layer composed of a cured product of the pressure-sensitive adhesive composition. Such component (A) can contribute to the formation of the pressure-sensitive adhesive layer by progressing polymerization (preferably thermal polymerization) and crosslinking.

More specifically, the position of the hydroxyl group in the molecule of the component (A) is not particularly limited, but the component (A) preferably has a hydroxyl group at least at both ends. The component (A) is not particularly limited as long as it is a urethane prepolymer satisfying these requirements, and known ones can be used.

It is widely known that the urethane prepolymer can be obtained by reacting a component having two or more hydroxyl groups (for example, a polyol component) with a polyfunctional isocyanate component. Examples of the component (A) include those obtained by reacting a component (a1): a polyol with a component (a2): a polyfunctional isocyanate.

The component (a1) is not particularly limited, and a known polyol can be used. For example, known polyether polyols, known polyether polyols, known polyester polyols, known polycarbonate polyols, known polybutadiene polyols, known polyisoprene polyols, etc. can be used. These may be used alone or in combination of two or more. When two or more kinds are used, two or more kinds of the same series may be combined, or one or more kinds of different series may be combined. The number of hydroxyl groups of these polyols is not particularly limited, but is preferably in the range of 2 or more and 4 or less in one molecule.

Examples of the polyether polyol include polyether polyols having a repeating structure such as an alkylene oxide chain such as a methylene oxide chain, an ethylene oxide chain, a propylene oxide chain and a butylene oxide chain. The alkylene oxide chains may be used alone or in combination of two or more. Among these, those having a hydroxyl group bonded to a primary carbon atom are preferable in terms of excellent reactivity with an isocyanate group. Specific examples include, but are not limited to, polyethylene glycol, polypropylene glycol, polypropylene glycol with a terminal polyethylene glycol cap, polytetramethylene glycol, and the like.

Examples of the polyester polyol include those composed of a known acid component and a known alcohol component. Examples of the acid component include adipic acid, azelaic acid, sebacic acid, phthalic anhydride, isophthalic acid, terephthalic acid, trimellitic acid and the like. Examples of the alcohol component include ethylene glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, Examples include neopentyl glycol, butylethylpropane diol, glycerin, trimethylolpropane, pentaerythritol and the like. The acid component and the alkali component may be used alone or in combination of two or more kinds. Other examples of the polyester polyol include those obtained by ring-opening polymerization of lactones such as polycaprolactone, poly(β-methyl-γ-valerolactone), and polyvalerolactone.

Examples of the polycarbonate polyol include those obtained by reacting a known carbonic acid ester or phosgene with a known compound having two or more hydroxyl groups. Examples of the carbonic acid ester include methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like. Examples of the compound having two or more hydroxyl groups include aliphatic polyols, alicyclic polyols, aromatic polyols and the like. Examples of the aliphatic polyol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 2,5-hexanediol, 1 ,7-Heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 2-methyl-1,3-propane Diol, neopentyl glycol, 2-butyl-2-ethyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8 -Octanediol and the like. Examples of the alicyclic polyol include 1,2-cyclobutanediol, 1,3-cyclopentanediol, 1,4-cyclohexanedimethanol, cycloheptanediol, cyclooctanediol, hydroxypropylcyclohexanol and the like. Examples of aromatic polyols include bisphenol A, bisphenol F, and 4,4'-biphenol. The carbonate ester and the compound having two or more hydroxyl groups may be used alone or in combination of two or more kinds.

The number average molecular weight of the component (a1) is not particularly limited, but is preferably 700 or more and 5,000 or less. The number average molecular weight of the component (a1) is more preferably 1,000 or more and 4,000 or less. Within the above range, the reaction control during synthesis becomes easier. The number average molecular weight of the component (a1) can be obtained as a polystyrene conversion value by a gel permeation chromatography (GPC) method.

Moreover, you may replace a part of (a1) component with low molecular weight polyols and polyvalent amines as needed. Examples of the low molecular weight polyols include ethylene glycol, 1,4-butanediol, 2-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, butylethylpropanediol, Examples thereof include glycerin, trimethylolpropane, pentaerythritol, dimer diol, castor oil polyol and the like. Examples of polyvalent amines include ethylenediamine, N-aminoethylethanolamine, isophoronediamine, xylylenediamine and the like.

The component (a2) is not particularly limited, and a known polyfunctional isocyanate can be used. Examples thereof include aromatic diisocyanates such as xylylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate. In addition, for example, hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, diisocyanatomethylcyclohexane, tetramethylxylylene diisocyanate, and other aliphatic or alicyclic diisocyanates can be mentioned. .. Further, adducts, burettes, isocyanurates, etc. of these diisocyanates can be mentioned. The polyfunctional isocyanate compounds may be used alone or in combination of two or more. Among these, aliphatic or alicyclic diisocyanates are preferred from the viewpoint of suppressing discoloration, and aliphatic diisocyanates are more preferred from the viewpoint of easier reaction control during synthesis.

The component (A) preferably contains a urethane prepolymer having a polyether skeleton and two or more hydroxyl groups. Due to its molecular structure, the polyether skeleton has a function of imparting high wettability to various adherends such as glass. Therefore, when the urethane polymer is used, the wettability of the pressure-sensitive adhesive layer with respect to the adherend is further improved as compared with the case where another urethane prepolymer is used.

The urethane prepolymer having a polyether skeleton and two or more hydroxyl groups is more specifically a urethane oligomer or polyurethane having a polyether structure as a part of the main chain and having two or more hydroxyl groups in one molecule. is there. The polyether structure represents, for example, a repeating structure of an alkylene oxide chain such as a methylene oxide chain, an ethylene oxide chain, a propylene oxide chain and a butylene oxide chain.

Among the urethane prepolymers having a polyether skeleton and two or more hydroxyl groups, a urethane prepolymer having a polyether skeleton and two or more hydroxyl groups and a (meth)acryloyloxy group is more preferable. According to the urethane prepolymer, the reworkability of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer is further improved. It is presumed that this is because the component (E) described later promotes photopolymerization and cross-linking reaction of the component (A) or the component (A) and the component (B) described below or its (co)polymer. ing. The position of the (meth)acryloyloxy group in the urethane prepolymer molecule is not particularly limited, but it is preferable to have a (meth)acryloyloxy group as a side chain. According to the urethane prepolymer, the effect of improving the reworkability of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer is further enhanced.

The urethane prepolymer having a polyether skeleton and two or more hydroxyl groups is not particularly limited, and known ones can be used. Examples thereof include those obtained by reacting a polyether polyol, which is one type of the above-mentioned component (a1), with the above-mentioned component (a2).

Moreover, the polyether skeleton, and the urethane prepolymer having two or more hydroxyl groups and (meth)acryloyloxy groups are not particularly limited, and known ones can be used. For example, those obtained by reacting the component (a1), the component (a2) and the component (a3): a (meth)acrylate compound having a hydroxyl group or an isocyanate group (a compound having a (meth)acryloyloxy group) Can be mentioned. Here, the component (a3) is used for the purpose of introducing a (meth)acryloyloxy group into the component (A).

The component (a3) is not particularly limited, and a known (meth)acrylate compound having a hydroxyl group or an isocyanate group can be used. Among these, a (meth)acrylate compound having a hydroxyl group is preferable from the viewpoints of easy availability of raw materials, curability and adhesive properties.

As the (meth)acrylate compound having a hydroxyl group, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4 -Hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, hydroxyethylacrylamide, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, polyethylene glycol mono Examples thereof include acrylate and polypropylene glycol monoacrylate.

Examples of the (meth)acrylate compound having an isocyanate group include 2-(meth)acryloyloxyethyl isocyanate, 2-(2-(meth)acryloyloxyethyloxy)ethyl isocyanate, and 1,1-bis((meth)acryloyl. Oxymethyl)ethyl isocyanate and the like.

In addition, as the urethane prepolymer having a polyether skeleton and two or more hydroxyl groups and (meth)acryloyloxy groups, the following may be used. For example, those obtained by reacting the component (a1), a trifunctional or higher polyfunctional isocyanate, and a compound having two or more isocyanate groups, which is a reaction product of a (meth)acrylate compound having a hydroxyl group. Are listed. Here, the trifunctional or higher polyfunctional isocyanate is not particularly limited, and for example, the same compounds as the compounds shown in the section of the component (C) described later can be used. Further, the (meth)acrylate compound having a hydroxyl group is not particularly limited, and for example, the same compounds as the above-mentioned component (a3) can be used. In addition, for example, it is obtained by reacting the component (a2), a trifunctional or higher functional polyol, and a compound having two or more hydroxyl groups, which is a reaction product of a (meth)acrylate compound having an isocyanate group. There are things. Here, the tri- or higher functional polyol is not particularly limited, and for example, the same compounds as the compounds shown in the item of the above (a1) component can be used. Further, the (meth)acrylate compound having an isocyanate group is not particularly limited, and for example, the same one as the component (a3) can be used.

The number average molecular weight of the component (A) is not particularly limited, but it is preferably 1,000 or more. Further, the number average molecular weight of the component (A) is more preferably 20,000 or more and 500,000 or less, and further preferably 50,000 or more and 200,000 or less. Within the above range, the viscosity of the pressure-sensitive adhesive composition will be in a more appropriate range, and the workability will be further improved.

The number average molecular weight of the component (A) can be calculated, for example, by the following method. To the sample bottle, 10 mg of the component (A) and 10 ml of THF were added, and the mixture was allowed to stand overnight to dissolve it, and filtered with a PTFE cartridge filter (0.5 μm) to obtain a sample. RI detector RI8020 (manufactured by Tosoh Corporation) is used as a detector, and TSKgelGMR-HHRL (manufactured by Tosoh Corporation)×2 series, HLC-8020GPC (manufactured by Tosoh Corporation) are used as measurement columns. The measurement conditions are such that the column temperature is 40° C., the flow rate is 1.0 ml/min, and the solvent is THF, and the number average molecular weight is analyzed as a third-order approximation curve calibration curve using standard polystyrene manufactured by Tosoh Corporation.

The hydroxyl value of the component (A) is not particularly limited, but is preferably 1 mg·KOH/g or more and 230 mg·KOH/g or less. Further, the hydroxyl value of the component (A) is more preferably 3 mg·KOH/g or more and 150 mg·KOH/g or less, further preferably 4 mg·KOH/g or more and 100 mg·KOH/g or less. Within the above range, the adhesive strength of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer will be in a more appropriate range, and the effect of reducing the occurrence of falling off of the pressure-sensitive adhesive layer will be further improved. It is presumed that this is because the polymerization of the component (A) and the component (C) described later and the progress of the crosslinking reaction are more appropriate. The hydroxyl value can be determined by measurement according to JIS K0070:1992. Here, the hydroxyl value of the component (A) can be one index of the content of hydroxyl groups.

The double bond equivalent (polymer mass (g) per mol of double bond) of the component (A) is not particularly limited, but is preferably 30,000 g/mol or less. Further, the double bond equivalent of the component (A) is more preferably 20,000 g/mol or less, further preferably 10,000 g/mol or less. The double bond equivalent of the component (A) is not particularly limited, but is preferably 1,000 g/mol or more. Within the above range, the adhesive strength of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer will be in a more appropriate range, and the occurrence of falling off of the pressure-sensitive adhesive layer will be further reduced. It is presumed that the progress of the photopolymerization and the crosslinking reaction of the component (A) or the component (A) and the component (B) or its (co)polymer by the component (E) described later becomes more appropriate. doing. Here, when the component (A) has a (meth)acryloyloxy group, the double bond equivalent of the component (A) can be one indicator of the content of the (meth)acryloyloxy group.

The component (A) may be a synthetic product or a commercially available product.

The method for producing the component (A) is not particularly limited, and a known method for synthesizing a urethane compound can be used. Among these, it is preferable to use a known urethanization reaction and apply the conditions under which the hydroxyl groups become excessive. As the component (A) and the production method thereof, known compounds and known production methods described in JP-A-2005-169377 and JP-A-2007-168377 may be used. Further, when the component (A) is produced, a known polymerization inhibitor, a known urethanization catalyst, etc. may be used if necessary.

As commercially available products, for example, Cyavine (registered trademark) SH101 manufactured by Toyo Ink Co., Ltd., Art Resin (registered trademark) UN5500, UN5500P manufactured by Negami Kogyo Co., Ltd. and the like can be used.

The urethane prepolymer constituting the component (A) may be used alone or in combination of two or more kinds.

[(B) component: polyfunctional (meth)acrylate]
The pressure-sensitive adhesive composition according to one aspect of the present invention includes (B) component: polyfunctional (meth)acrylate (B). The component (B) has a function of undergoing photopolymerization and cross-linking reaction upon irradiation with light, and thus can contribute to improvement of reworkability due to a decrease in adhesive strength after irradiation with light. When the component (B) is not contained, the adhesive force does not decrease due to light irradiation and reworkability becomes insufficient.

Component (B) is not particularly limited as long as it is a compound containing two or more (meth)acryloyloxy groups in one molecule. Among these, a bifunctional or more and 10 functional or less (meth)acrylate etc. are mentioned as a preferable example. The component (B) may be, for example, an 11-functional or higher-functional (meth)acrylate such as an 11-functional or higher-functional polypentaerythritol poly(meth)acrylate.

Examples of the bifunctional (meth)acrylate include dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, and 1,6-hexanediol di(meth)acrylate. ) Acrylate, neopentyl glycol di(meth)acrylate, propylene oxide-modified neopentyl glycol di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, dicyclopentanyl Di(meth)acrylate, caprolactone modified dicyclopentenyl di(meth)acrylate, polyethylene glycol di(meth)acrylate, modified bisphenol A di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, ethylene oxide modified phosphoric acid Di(meth)acrylate, allylic cyclohexyl di(meth)acrylate, isocyanurate di(meth)acrylate, pentaerythritol di(meth)acrylate, dipentaerythritol di(meth)acrylate, tripentaerythritol di(meth)acrylate, tetra Examples thereof include pentaerythritol di(meth)acrylate.

Examples of trifunctional (meth)acrylates include pentaerythritol tri(meth)acrylate, diventaerythritol tri(meth)acrylate, tripentaerythritol tri(meth)acrylate, tetrapentaerythritol tri(meth)acrylate, propionic acid-modified diester. Pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane ethoxytri(meth)acrylate, ethylene oxide modified trimethylolpropane tri(meth)acrylate, propylene oxide modified trimethylolpropane tri(meth)acrylate , Polyether tri(meth)acrylate, glycerin propoxytri(meth)acrylate, tris(acryloxyethyl)isocyanurate and the like.

Examples of tetrafunctional (meth)acrylates include pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, tripentaerythritol tetra(meth)acrylate, tetrapentaerythritol tetra(meth)acrylate, pentaerythritol ethoxytetra. (Meth)acrylate, ditrimethylolpropane tetra(meth)acrylate and the like can be mentioned.

Examples of pentafunctional (meth)acrylates include dipentaerythritol penta(meth)acrylate, tripentaerythritol penta(meth)acrylate, tetrapentaerythritol penta(meth)acrylate, propionic acid-modified dipentaerythritol penta(meth)acrylate, Examples include dipentaerythritol monohydroxypenta(meth)acrylate.

Examples of the hexafunctional (meth)acrylate include dipentaerythritol hexa(meth)acrylate, tripentaerythritol hexa(meth)acrylate, tetrapentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate. Can be mentioned.

Examples of the 7-functional (meth)acrylate include tripentaerythritol hepta(meth)acrylate and tetrapentaerythritol hepta(meth)acrylate.

Examples of the octafunctional (meth)acrylate include tripentaerythritol octa(meth)acrylate and tetrapentaerythritol octa(meth)acrylate.

Examples of the 9-functional (meth)acrylate include tetrapentaerythritol nona(meth)acrylate.

Examples of the 10-functional (meth)acrylate include tetrapentaerythritol deca(meth)acrylate.

Among these, trifunctional (meth)acrylate is preferable, trimethylolpropane tri(meth)acrylate is more preferable, and trimethylolpropane triacrylate is further preferable.

Further, as the compound containing two or more (meth)acryloyloxy groups in one molecule, urethane (meth)acrylate, polyester (meth)acrylate and the like may be used.

Urethane (meth)acrylate is not particularly limited. Examples thereof include monomers and oligomers obtained by reacting diisocyanate, polyol, and a (meth)acrylate compound having a hydroxyl group. Examples of urethane (meth)acrylates include urethane (meth)acrylates described in JP-A-2002-265650, JP-A-2002-355936, JP-A-2002-067238 and the like.

Examples of the diisocyanate include TDI, MDI, HDI, IPDI, HMDI and the like.

Examples of the polyol include poly(propylene oxide)diol, poly(tetramethylene oxide)diol, ethoxylated bisphenol A, ethoxylated bisphenol S spiroglycol, caprolactone-modified diol, carbonate diol, and the like.

Examples of the (meth)acrylate compound having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, glycidol di(meth)acrylate, and pentaerythritol triacrylate.

The specific urethane (meth)acrylate is not particularly limited. For example, an adduct of TDI and hydroxyethyl acrylate, an adduct of IPDI and hydroxyethyl acrylate, an adduct of HDI and pentaerythritol triacrylate (PETA), an adduct of TDI and PETA is prepared, and the remaining isocyanate is formed. And a dodecyloxyhydroxypropyl acrylate compound, an adduct of 6,6 nylon with TDI, an adduct of pentaerythritol with TDI and hydroxyethyl acrylate, and the like.

The polyester (meth)acrylate is obtained by condensing (meth)acrylic acid on the hydroxy group remaining in the polyester skeleton synthesized from a polyol and a dibasic acid to give an acrylate.

The specific polyester acrylate is not particularly limited. Examples thereof include a reaction product of phthalic anhydride/propion oxide/acrylic acid, a reaction product of adipic acid/1,6-hexanediol/acrylic acid, and a reaction product of trimellitic acid/diethylene glycol/acrylic acid.

Further, the component (B) preferably further contains a hydroxyl group. By having such a structure, the occurrence of falling off of the pressure-sensitive adhesive layer is further reduced. When the component (A) and the component (C) are polymerized and cross-linked, the component (A) and the component (B) or its (co)polymer are polymerized and cross-linked. I'm guessing that this is because it will proceed.

The hydroxyl value of the component (B) is not particularly limited, but is preferably 100 mg·KOH/g or less. Further, the hydroxyl value of the component (B) is more preferably 50 mg·KOH/g or less, further preferably 30 mg·KOH/g or less. (Lower limit 0 mg·KOH/g) Within the above range, the adhesive strength of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer will be in a more appropriate range, and the occurrence of dropout of the pressure-sensitive adhesive layer will be further reduced. The progress of the polymerization and the crosslinking reaction of the component (B) or its (co)polymer with the component (C) is in a proper range, and the polymerization and the crosslinking reaction of the component (A) and the component (C) are better. I'm guessing that this is because it progresses to. The hydroxyl value can be determined by measurement according to JIS K0070:1992.

The component (B) may be a synthetic product or a commercially available product. Examples of commercially available products include A-TMPT, A-TMM-3, A-TMM-3L, A-TMM-3LM-N, ATM-35E, A-TMMT, and A-9550 manufactured by Shin-Nakamura Chemical Co., Ltd. , A-DPH, Aronix (registered trademark) M-305, M-402, M-405 manufactured by Toagosei Co., Ltd., Viscoat (registered trademark) #295, TMPTA, #802, TriPEA manufactured by Osaka Organic Chemical Industry Co., Ltd. Etc.

The polyfunctional (meth)acrylates may be used alone or in combination of two or more.

The content of the component (B) in the pressure-sensitive adhesive composition (the total amount when two or more types are contained) is not particularly limited, but is 1 part by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the component (A). It is preferable to have. The content of the component (B) is more preferably 5 parts by mass or more and 250 parts by mass or less with respect to 100 parts by mass of the component (A). The content of the component (B) is more preferably 10 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the component (A). Within the above range, the adhesive force of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer will be in a more appropriate range. It is presumed that the reason is that when the content ratio of the component (A) and the component (B) is in an appropriate range, the adhesive force is in a better range. Moreover, when it is in the above range, the reworkability of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer is further improved. It is speculated that this is because the photopolymerization and cross-linking reaction of the component (B) due to light irradiation during reworking proceed further. Further, in the above range, when the component (B) further has a hydroxyl group, the occurrence of detachment of the pressure-sensitive adhesive layer is further reduced. When the component (A) and the component (C) are polymerized and cross-linked, the component (A) and the component (B) or its (co)polymer are polymerized and cross-linked. I'm guessing that this is because it will proceed.

From this, as a preferable example of the component (B), the content of the component (B) with respect to 100 parts by mass of the component (A) is 10 parts by mass or more and 150 parts by mass or less, and the hydroxyl value of the component (B) is It may be 100 mg·KOH/g or less.

[Component (C): Crosslinking agent]
The pressure-sensitive adhesive composition according to one aspect of the present invention includes (C) component: a crosslinking agent. The component (C) has a function of advancing polymerization (preferably thermal polymerization) and crosslinking with the component (A). Therefore, the adhesive strength of the pressure-sensitive adhesive composition and the adhesive strength after light irradiation can be set in an appropriate range, which can contribute to compatibility of adhesiveness and reworkability. When the component (C) is not contained, the adhesive force becomes excessive and reworkability becomes insufficient.

The component (C) is not particularly limited as long as it can promote the polymerization and crosslinking reaction with the component (A). For example, an isocyanate type crosslinking agent, a carbodiimide type crosslinking agent, an oxazoline type crosslinking agent, an epoxy type crosslinking agent, an aziridine type crosslinking agent, a peroxide, etc. are mentioned. Here, the peroxide means a compound having a peroxide structure “—O—O—” in the molecular structure. These may be used alone or in combination of two or more. When two or more kinds are used, two or more kinds of the same series may be combined, or one or more kinds of different series may be combined.

The isocyanate crosslinking agent is not particularly limited, and a known compound having an isocyanate group (isocyanate compound) can be used. Examples of the compound having an isocyanate group include monofunctional isocyanate and polyfunctional isocyanate. Of these, polyfunctional isocyanates are preferable. Examples of polyfunctional isocyanates include bifunctional isocyanates (compounds having two isocyanate groups) and trifunctional or higher functional isocyanates (compounds having three or more isocyanate groups).

Examples of the bifunctional isocyanate include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, carbodiimide-modified diisocyanates of these diisocyanates, or these diisocyanates at the main chain end, side chain, or side chain end. Examples thereof include polymer compounds.

Examples of the aliphatic diisocyanates include 1,5-pentamethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate and norbornane diisocyanatomethyl (NBDI).

Examples of alicyclic diisocyanates include transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), H6-XDI (hydrogenated XDI), H12-MDI (hydrogenated MDI), and the like.

Examples of aromatic diisocyanates include dimer acid diisocyanate, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), and 4,4'-diphenylmethane diisocyanate. (4,4′-MDI), 2,4′-diphenylmethane diisocyanate (2,4′-MDI), 1,4-phenylene diisocyanate, xylylene diisocyanate (XDI), tetramethylxylidene diisocyanate (TMXDI), tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI) and the like.

Examples of the tri- or higher functional isocyanate include polyisocyanate-polyisocyanate-modified isocyanurate-modified isocyanurates, bifunctional isocyanate-adduct-modified adducts, and bifunctional isocyanates such as glycerin and trimethylolpropane. Examples thereof include a biuret body obtained by biuret-modifying a trihydric alcohol, the above-mentioned bifunctional isocyanate, or an adduct body thereof, a biuret body or an isocyanurate body at a main chain terminal, a side chain, or a side chain terminal.

The carbodiimide-based crosslinking agent is not particularly limited, and a known carbodiimide compound can be used. Examples of the carbodiimide compound include high molecular weight polycarbodiimide produced by decarboxylation condensation reaction of diisocyanate in the presence of a carbodiimidization catalyst. Examples of the diisocyanate used for the decarboxylation condensation reaction include 4,4′-diphenylmethane diisocyanate, 3,3′-dimethoxy-4,4′-diphenylmethane diisocyanate, and 3,3′-dimethyl-4,4′-diphenylmethane. Diisocyanate, 4,4'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1-methoxyphenyl-2,4- Examples thereof include diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, tetramethylxylylene diisocyanate and the like. Examples of the carbodiimidization catalyst used in the decarboxylation condensation reaction include, for example, 1-phenyl-2-phospholen-1-oxide, 3-methyl-2-phospholen-1-oxide, 1-ethyl-3-methyl-2. -Phosphorene-1-oxide, 1-ethyl-2-phospholen-1-oxide, phospholene oxides such as 3-phospholene isomers thereof, and the like.

The oxazoline-based crosslinking agent is not particularly limited, and known oxazoline compounds can be used. Examples of the oxazoline compound include oxazoline group-containing polymers. Specific examples of the oxazoline compound include an oxazoline group-containing acrylic polymer and an oxazoline group-containing acrylic/styrene-based polymer. Here, as the oxazoline group-containing acrylic polymer, for example, an oxazoline group-containing acrylic polymer that includes a main chain composed of an acrylic skeleton and has an oxazoline group in a side chain of the main chain can be cited. Examples of the oxazoline group-containing acrylic/styrene-based polymer include an oxazoline group-containing acrylic/styrene-based polymer having a main chain composed of an acrylic skeleton or a styrene skeleton and having an oxazoline group on the side chain of the main chain. Are listed. Examples of the oxazoline group include a 2-oxazoline group, a 3-oxazoline group, a 4-oxazoline group and the like.

The epoxy cross-linking agent is not particularly limited, and a known epoxy compound can be used. Examples of epoxy compounds include liquid epoxy compounds. The liquid epoxy compound is preferable because it facilitates the mixing operation when producing the pressure-sensitive adhesive composition.

The aziridine-based crosslinking agent is not particularly limited, and a known aziridine compound can be used. Examples of the aziridine compound include polyfunctional aziridine compounds having a plurality of aziridine rings. Examples of the polyfunctional aziridine compound include, for example, US Pat. No. 3,225,013, US Pat. No. 4,490,505, US Pat. The compound etc. which were disclosed by 104970 gazette are mentioned. As the polyfunctional aziridine compound, a trifunctional aziridine compound (a compound having three aziridine rings) can be preferably used. Examples of the trifunctional aziridine compound include trimethylolpropane tris[3-aziridinylpropionate], trimethylolpropane tris[3-(2-methyl-aziridinyl)-propionate], and trimethylolpropane tris[2-azide]. Lysinyl butyrate], pentaerythritol tris-3-(1-aziridinyl propionate), pentaerythritol tetrakis-3-(1-aziridinyl propionate), and the like.

The peroxide is not particularly limited and known ones can be used. Peroxides are, for example, diisopropyl peroxydicarbonate, bis(2-ethylhexyl)peroxydicarbonate, bis(4-t-butylcyclohexyl)peroxydicarbonate (also known as bis(4-t-butyl peroxydicarbonate). Cyclohexyl), bis-sec-butyl peroxydicarbonate, t-butyl peroxy neodecanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, dilauroyl peroxide, bis-n-octanoyl. Peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, bis(4-methylbenzoyl)peroxide, dibenzoylperoxide (benzoyl peroxide), t-butylperoxybutyrate Etc.

Among these, an isocyanate crosslinking agent or a peroxide is preferable, and an isocyanate crosslinking agent is more preferable. It is more preferable to use the isocyanate cross-linking agent alone or to use the isocyanate cross-linking agent and the peroxide in combination.

Examples of the isocyanate-based cross-linking agent include hexamethylene diisocyanate (HDI) or pentamethylene diisocyanate (PDI), adducts, biurets or isocyanurates thereof, or high-molecular compounds containing these at the main chain end, side chain or side chain end. Molecular compounds are preferred. Further, as the isocyanate cross-linking agent, an adduct of hexamethylene diisocyanate (HDI) or pentamethylene diisocyanate (PDI) is more preferable. Alternatively, a polymer compound obtained by a condensation reaction of hexamethylene diisocyanate (HDI) or pentamethylene diisocyanate (PDI) and a diol is more preferable. Here, preferable examples of hexamethylene diisocyanate (HDI) include 1,6-hexamethylene diisocyanate. Moreover, 1,5-pentamethylene diisocyanate etc. are mentioned as a preferable example of pentamethylene diisocyanate (PDI). According to these isocyanate crosslinking agents, the polymerization with the component (A) and the progress of the crosslinking reaction can be carried out more efficiently.

Bis(4-t-butylcyclohexyl)peroxydicarbonate is preferable as the peroxide. According to the peroxide, the polymerization with the component (A) and the progress of the crosslinking reaction can be carried out more efficiently.

The component (C) may be a synthetic product or a commercially available product. Examples of commercially available products include isocyanate-based crosslinking agents such as Coronate (registered trademark) L (for example, L-45E) manufactured by Tosoh Corporation, HL, HX, 2030, 2031 and Takenate (registered by Mitsui Chemicals, Inc.). Trademark) D-102, D-110N, D-200, D-202, Duranate (registered trademark) 24A-100, TPA-100, TKA-100, P301-75E, E402-80B, E402 manufactured by Asahi Kasei Chemicals Corporation. -90T, E405-80T, TSE-100, D-101, D-201, Sumikajure Bayer Urethane Co., Ltd. N-75, N-3200, N-3300, manufactured by Mitsui Chemicals, Inc. Stabio (registered trademark) D-370N, D-376N, Nippon Soda Co., Ltd. NISSO-PB (registered trademark) TP1001 etc. are mentioned. Examples of the carbodiimide-based cross-linking agent include Carbodilite (registered trademark) V-01, V-03, V-05, V-07, V-09 manufactured by Nisshinbo Chemical Co., Ltd. Examples of the oxazoline-based cross-linking agent include Epocros (registered trademark) WS-300, WS-500, WS-700, K-1000 series, and K-2000 series manufactured by Nippon Shokubai Co., Ltd. Examples of the epoxy-based crosslinking agent include TETRAD-C and TETRAD-X manufactured by Mitsubishi Gas Chemical Co., Inc., ADEKA Resin EPU series manufactured by ADEKA CORPORATION, EPR series, and Celoxide series manufactured by Daicel Corporation. Examples of the aziridine-based cross-linking agent include Chemitite (registered trademark) PZ-33 and DZ-22E manufactured by Nippon Shokubai Co., Ltd. Examples of the peroxide include Percumyl (registered trademark) ND, Perloyl (registered trademark) IB, NPP, IPP, SBP, TCP, OPP, 355, L, SA, Perocta (registered trademark) ND manufactured by NOF CORPORATION. O, Perhexyl (registered trademark) ND, PV, O, I, Perbutyl (registered trademark) ND, NHP, PV, O, L, I, A, Perhexa (registered trademark) 25O, MC, TMH, HC, C, 25Z , 22, Nyper (registered trademark) PMB, BMT, BW, BMT-K40, BMT-M, and Pertetra (registered trademark) A.

The amount of the component (C) added to the pressure-sensitive adhesive composition is not particularly limited as long as it is an amount capable of promoting polymerization and crosslinking reaction with the component (A).

When the component (C) contains an isocyanate crosslinking agent (compound having an isocyanate group), the equivalent ratio of the total amount of isocyanate groups of the compound having an isocyanate group to the total amount of hydroxyl groups of the component (A) in the pressure-sensitive adhesive composition (NCO( The total (mol)/OH (mol)) is preferably 0.2 or more and 10 or less. Further, the equivalent ratio is more preferably 0.4 or more and 10 or less, and further preferably 0.5 or more and 6 or less. And it is especially preferable that the equivalent ratio is 1 or more and 4.5 or less. Within the above range, the adhesive strength of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer will be in a more appropriate range, and the occurrence of falling off of the pressure-sensitive adhesive layer will be further reduced. It is presumed that this is because the progress of polymerization and crosslinking reaction with the component (A) becomes more appropriate.

The component (C) preferably contains a bifunctional isocyanate or a trifunctional or higher functional isocyanate.

When the component (C) contains an isocyanate crosslinking agent (compound having an isocyanate group), the equivalent ratio of the amount of the isocyanate group of the bifunctional isocyanate to the total amount of the isocyanate groups of the compound having an isocyanate group in the pressure-sensitive adhesive composition (NCO( Bifunctional) (mol)/NCO (total) (mol)) is preferably 0 or more and 1 or less. Further, since the compound having an isocyanate group as the component (C) preferably contains a bifunctional isocyanate, the equivalent ratio is more preferably more than 0 and 1 or less. Further, the equivalent ratio is more preferably more than 0 and less than 1, and even more preferably 0.25 or more and less than 1. Further, the equivalent ratio is particularly preferably 0.5 or more and 0.95 or less, and further preferably 0.7 or more and 0.9 or less. Within the above range, the adhesive force of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer will be in a more appropriate range. In particular, when it is at least the above lower limit value, the occurrence of detachment of the pressure-sensitive adhesive layer is further reduced. It is presumed that this is because the progress of polymerization and crosslinking reaction with the component (A) becomes more appropriate. Moreover, when it is at most the above upper limit value, it is possible to more reliably suppress bleed-out of an additive component such as the component (F) described later from the pressure-sensitive adhesive layer. It is presumed that this is because the crosslinking density becomes higher and diffusion of these components in the pressure-sensitive adhesive layer becomes more difficult to occur.

The component (C) preferably contains a trifunctional or higher functional isocyanate. According to the isocyanate, bleed-out of an additive component such as the component (F) described below from the pressure-sensitive adhesive layer can be more reliably suppressed, and the substrate contamination property is further improved. It is speculated that this is because the crosslink density between the components (A) in the pressure-sensitive adhesive layer becomes higher, and diffusion of these components in the pressure-sensitive adhesive layer becomes less likely to occur.

When the component (C) contains a cross-linking agent other than the isocyanate cross-linking agent, the content of the cross-linking agent (when two or more kinds are contained, the total amount thereof) is 0.01 with respect to 100 parts by mass of the component (A). It is preferably from 20 parts by mass to 20 parts by mass. The content of the cross-linking agent is more preferably 0.1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the component (A). The content of the crosslinking agent is more preferably 0.5 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the component (A). Within the above range, the adhesive strength of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer will be in a more appropriate range, and the occurrence of falling off of the pressure-sensitive adhesive layer will be further reduced. It is presumed that this is because the progress of the polymerization and cross-linking reaction between the component (A) or the component (B) or its (co)polymer becomes more appropriate.

[(D) component: crosslinked particles]
The pressure-sensitive adhesive composition according to one aspect of the present invention includes (D) component: crosslinked particles. In the present specification, the crosslinked particles represent particles having a crosslinked structure as at least a part of the structure constituting the particles. The component (D) has a function of forming irregularities on the surface of the pressure-sensitive adhesive layer. Here, the unevenness is formed in the pressure-sensitive adhesive layer, so that the pressure-sensitive adhesive force is reduced. Therefore, the component (D) can contribute to further improving the tackiness by setting the tackiness of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer before light irradiation to an appropriate range. Further, the component (D) can further reduce the adhesive force at the time of rework and contribute to the improvement of reworkability. When the component (D) is not contained, the tackiness of the tackiness before light irradiation becomes excessive, resulting in poor tackiness. Further, the adhesive strength after light irradiation becomes excessive and the reworkability becomes insufficient. The component (D) is not particularly limited, and known crosslinked particles can be used. Examples thereof include styrene crosslinked particles, (meth)acrylic crosslinked particles, fluorine-modified (meth)acrylic crosslinked particles, styrene-(meth)acrylic crosslinked particles, urethane crosslinked particles, and silicone crosslinked particles.

The styrene-based crosslinked particles are crosslinked particles composed of a structural unit in which at least 50% by mass is composed of a styrene-based monomer.

The (meth)acrylic crosslinked particles are crosslinked particles in which at least 50% by mass or more has a structural unit derived from a monomer having a (meth)acryloyloxy group ((meth)acrylate monomer). Here, examples of the (meth)acrylate-based monomer include a combination of a known monofunctional (meth)acrylate and a known polyfunctional (meth)acrylate. As a preferred specific example, the (meth)acrylic crosslinked particles include crosslinked particles mainly containing polymethylmethacrylate (PMMA).

The styrene-(meth)acrylic crosslinked particles are crosslinked particles in which at least 50% by mass or more have a structural unit derived from a styrene monomer or a structural unit derived from a (meth)acrylate monomer.

The urethane-based crosslinked particles are crosslinked particles in which at least 50% by mass or more is composed of a polymer compound having a urethane bond or a urea bond. Examples of the polymer compound having a urethane bond or a urea bond include known reaction products of polyfunctional isocyanates and polyols, known reaction products of polyisocyanates and water, and the like.

Examples of the silicone-based crosslinked particles include those generally referred to as silicone rubber and those generally referred to as silicone resin, which are mainly solid particles at room temperature. Preferred specific examples include silicone resin powders that are solid at room temperature (polyorganosilsesquioxane cured product in which the siloxane bond has a three-dimensional network crosslinked structure).

Other examples of the crosslinked particles include crosslinked rubber particles other than those mentioned above.

Among these, the (meth)acrylic crosslinked particles or the silicone crosslinked particles are preferable, and the silicone crosslinked particles are more preferable, from the viewpoints of compatibility of tackiness and reworkability, punching processability, wettability and transparency.

The component (D) may be core-shell particles having a crosslinked structure constituting the above crosslinked particles as a core part or a shell part. The component (D) may be hollow particles.

The component (D) may be a coated particle obtained by further coating the surface of the particle having a crosslinked structure constituting the above crosslinked particle with a coating material. The coating material is not particularly limited, and a known coating material used for coating particles can be used. For example, natural resin, synthetic resin, silicone resin, metal, inorganic compound and the like can be mentioned.

The shape of the component (D) is not particularly limited. For example, a spherical shape, an elliptical shape, an indefinite shape, a needle shape, a plate shape, a hollow shape, a column shape, a pyramid shape and the like can be mentioned. Among these, the spherical shape is preferable, and the spherical shape is more preferable, from the viewpoint of reducing the adhesive strength.

The average particle size of the component (D) is not particularly limited, but is preferably 0.5 μm or more and 30 μm or less. The average particle diameter of the component (D) is more preferably 0.5 μm or more and 25 μm or less, and further preferably 0.5 μm or more and 20 μm or less. When it is at least the above lower limit, the pressure-sensitive adhesive layer and the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer will have better adhesiveness and reworkability will be further improved. It is speculated that this is because the size of the irregularities formed on the surface of the pressure-sensitive adhesive layer becomes larger, the pressure-sensitive adhesive force becomes in a more appropriate range, and the pressure-sensitive adhesive force after light irradiation further decreases. Moreover, when it is at most the above upper limit, the wettability of the adhesive layer with respect to the substrate is further improved. It is speculated that this is because the unevenness of the surface of the pressure-sensitive adhesive layer becomes smaller, and it becomes more difficult for air to enter the adhesive surface.

The color of the component (D) is not particularly limited, but it is preferably transparent from the viewpoint of ensuring the transparency of the adhesive film.

The component (D) may be a synthetic product or a commercially available product. Examples of commercially available products include Negami Kogyo Co., Ltd. Art Pearl (registered trademark) GR series, SE series (for example, SE-010T, SE-020T, etc.), G series, GS series, J series, MF series, MF series. , BR series (above, cross-linked acrylic beads, transparent type), C series, P series, JB series, U series, CE series, AK series, HI series, MM series, FF series, TK series, C-TH series, RT , RW, RX, RY, RZ series, RU series, RV series, BP series (above, crosslinked urethane beads, transparent type), Shin-Etsu Chemical Co., Ltd. KMP-600, KMP-601, KMP-602, KMP-605 , X-52-7030 (above, silicone composite powder), KMP-597, KMP-598, KMP-594, X-52-875 (above, silicone rubber powder), KMP-590, KMP-701, X-52. -854, X-52-1621 (above, silicone resin powder) etc. are mentioned.

The method for producing these crosslinked particles is not particularly limited, and a known method can be adopted. For example, a method of synthesizing a crosslinked polymer by a polymerization method such as suspension polymerization, sheet polymerization or emulsion polymerization, and then performing washing, drying, classification and the like to produce the polymer can be mentioned. Moreover, the method etc. which prepare the high molecular compound which has a reactive functional group, and bridge|crosslink the said high molecular compound are mentioned.

The crosslinked particles may be used alone or in combination of two or more kinds.

The content of the component (D) in the pressure-sensitive adhesive composition (when two or more kinds are contained, the total amount thereof) is 0.01 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the component (A). When it is less than the above lower limit, the adhesive strength becomes excessive, resulting in poor adhesiveness. Further, the adhesive force of the pressure-sensitive adhesive layer at the time of rework becomes excessive, and the reworkability of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer becomes insufficient. On the other hand, when the amount exceeds the upper limit, the adhesive force becomes too small, resulting in poor adhesiveness. Further, since the added amount of the component (D) becomes excessive, the component (D) is likely to drop off, and the punching workability deteriorates. Further, the unevenness of the surface of the pressure-sensitive adhesive layer becomes excessive, the wettability of the pressure-sensitive adhesive layer with respect to the adherend decreases, light diffusion easily occurs, and the transparency also decreases. From this, from the viewpoint of tackiness, reworkability, punching workability, wettability, and transparency, the content of the component (D) is 0.05 parts by mass or more and 5 parts by mass or more with respect to 100 parts by mass of the component (A). It is more preferably not more than part. The content of the component (D) is more preferably 0.1 part by mass or more and 1 part by mass or less with respect to 100 parts by mass of the component (A).

[Component (E): Photoradical Initiator]
The pressure-sensitive adhesive composition according to one aspect of the present invention includes (E) component: a photoradical initiator. The component (E) has a function of generating radicals by light irradiation, and by promoting photopolymerization and crosslinking of the component (B), it is possible to contribute to improvement of reworkability due to a decrease in adhesive strength after light irradiation. .. When the component (E) is not contained, the adhesive force does not decrease due to light irradiation and the reworkability becomes insufficient.

The component (E) is not particularly limited, and known ones can be used. Examples thereof include acetophenone compounds, benzoin compounds, benzophenone compounds, thioxanthone compounds, anthraquinone compounds, and acylphosphine oxide compounds. Other examples include 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone and acrylated benzophenone.

Examples of the acetophenone compound include 4-phenoxydichloroacetophenone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, and 1-(4-isopropylphenyl)-2-hydroxy-2-methyl. Propan-1-one, 1-hydroxycyclohexyl phenyl ketone, 4-(2-hydroxyethoxy)-phenyl (2-hydroxy-2-propyl) ketone, 2-methyl-[4-(methylthio)phenyl]-2-morpholino Examples include -1-propanone and 2,2-dimethoxy-2-phenylacetophenone.

Examples of the benzoin compound include benzoin compounds such as benzoin, benzoin methyl ether, benzoin isoethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

Examples of the benzophenone compound include benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4′-methyldiphenylsulfide, and 3,3′-dimethyl-4-methoxybenzophenone. Can be mentioned.

Examples of the thioxanthone compound include thioxanthone, 2-chlorothioxanthone, 2,4-dichlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, and 2,4-diisopropylthioxanthone. Are listed.

Examples of the anthraquinone compound include 4,4′-dimethylaminothioxanthone (also known as Minerals ketone), 4,4′-diethylaminobenzophenone, α-acyloxime ester, benzyl, methylbenzoylformate, and 2-ethylanthraquinone. Etc.

Examples of the acylphosphine oxide compound include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.

Examples of the acrylated benzophenone include 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone and acrylated benzophenone.

Among these, an acylphosphine oxide compound is preferable, and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide is more preferable, from the viewpoint that the reworkability of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer can be further improved.

The component (E) may be a synthetic product or a commercially available product. Examples of commercially available products include Omnirad (registered trademark) 184, 369, 651, 819, 907, 1173 manufactured by IGM RESINS, TPO H, Ezacure (registered trademark) KIP150, TZT manufactured by DKSH Japan Co., Ltd., Nippon Kayaku Co., Ltd. Examples include KAYACURE (registered trademark) BMS and DMBI manufactured by Co., Ltd.

The photo-radical initiators may be used alone or in combination of two or more.

The content of the component (E) in the pressure-sensitive adhesive composition (the total amount when two or more types are contained) is not particularly limited, but is 0.01 part by mass or more and 20 parts by mass with respect to 100 parts by mass of the component (A). The following is preferable. Further, the content of the component (E) is more preferably 0.1 parts by mass or more and 10 parts by mass or less, and is 0.5 parts by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the component (A). It is more preferable that there is. The content of the component (E) is particularly preferably 1 part by mass or more and 2 parts by mass or less with respect to 100 parts by mass of the component (A). Within the above range, reworkability of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer is further improved. It is speculated that this is because the photopolymerization and cross-linking reaction of the component (B) due to light irradiation during reworking proceed further.

[Component (F): Antistatic agent]
The pressure-sensitive adhesive composition according to one aspect of the present invention preferably contains (F) component: an antistatic agent. The component (F) has a function of improving conductivity and can contribute to a reduction in the surface resistance value of the pressure-sensitive adhesive layer. Therefore, in particular, when it is necessary to peel (rework) due to a sticking error or the like after sticking to a liquid crystal cell or the like as an adherend, generation of static electricity can be effectively suppressed. As a result, it is possible to stably prevent dust from easily adhering to the surface of the polarizing plate or the like, disorder of liquid crystal alignment, or electrostatic breakdown of peripheral circuit elements. it can. From this, if the component (F) is not contained, the peeling electrification voltage becomes excessive.

The component (F) is not particularly limited, and known ones can be used. Examples thereof include ionic liquids, ionic conductive agents such as bis(fluorosulfonyl)imide salts, and surfactants.

As the ionic liquid, for example, phosphonium ion, pyridinium ion, pyrrolidinium ion, imidazolium ion, guanidinium ion, ammonium ion, isouronium ion, thiouronium ion, piperidinium ion, pyrazolium ion, sulfonium ion, fourth ion Cationic components such as quaternary ammonium and quaternary phosphonium, and halogen ions, nitrate ions, sulfate ions, phosphate ions, perchlorate ions, thiocyanate ions, thiosulfate ions, sulfite ions, tetrafluoroborate ions, hexafluorophosphate A substance having an anion component such as an ion, a formate ion, an oxalate ion, an acetate ion, a trifluoroacetate ion, and an alkylsulfonate ion can be given.

Specific examples of the ionic liquid, 1-allyl-3-methylimidazolium chloride, 1,3-dimethylimidazolium chloride, 1,3-dimethylimidazolium dimethylphosphate, 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium iodide, 1-ethyl-3-methanesulfonate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3 -Methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium-p-toluenesulfonate, 1-butyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium chloride, 1-methyl- 1-propyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-methyl-1-methylpyrrolidinium bromide, 1-butyl-1-methylpiperidinium bromide, 1-ethylpyridinium chloride, 1-ethylpyridinium bromide , 1-butylpyridinium chloride, 1-butylpyridinium bromide, 1-butyl-3-methylpyridinium chloride, 1-ethyl-3-methylpyridinium ethylsulfate, 1-butyl-4-methylpyridinium chloride, 1-butyl-4- Methylpyridinium hexafluorophosphate, trimethylpropylammonium bis(trifluoromethanesulfonyl)imide, tributylmethylammonium bis(trifluoromethanesulfonyl)imide (also known as tri-n-butylmethylammonium bistrifluoromethanesulfonimide), tetrabutylammonium chloride , Tetrabutylammonium bromide, cyclohexyltrimethylammonium bis(trifluoromethanesulfonyl)imide, tetrabutylphosphonium bromide and the like.

Examples of the surfactant include nonionic surfactants and ionic surfactants.

Examples of the nonionic surfactant include polyethylene glycol alkyl ether and polyoxyalkylene alkyl ether.

Examples of the ionic surfactant include a cationic surfactant such as an alkyltrimethylammonium halide having 8 or more and 22 or less carbon atoms, and an anionic surfactant such as an alkyl sulfate.

Among these, an ionic liquid is preferable, and tributylmethylammonium bis(trifluoromethanesulfonyl)imide is more preferable.

The component (F) may be a synthetic product or a commercially available product. Examples of commercially available products include 3M (trademark) ionic liquid type antistatic agent FC-4400 manufactured by 3M Japan Co., Ltd. for ionic liquids.

The antistatic agent may be used alone or in combination of two or more kinds.

The content of the component (F) in the pressure-sensitive adhesive composition (the total amount when two or more types are contained) is not particularly limited, but is 0.01 parts by mass or more and 30 parts by mass with respect to 100 parts by mass of the component (A). The following is preferable. Further, the content of the component (F) is more preferably 0.1 parts by mass or more and 20 parts by mass or less, and 0.5 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the component (A). More preferable. The content of the component (F) is more preferably 2 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the component (A). When it is at least the above lower limit, the peeling electrification voltage of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer is further reduced. Further, when it is at most the above upper limit, the substrate contamination of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive film having the pressure-sensitive adhesive layer is further improved.

[Component (G): Stabilizer]
The pressure-sensitive adhesive composition according to one aspect of the present invention may further contain a component (G): a stabilizer as long as the effect of the present invention is not impaired. The component (G) stabilizes the radicals generated by light (such as ultraviolet rays) that is weak enough to illuminate, thereby advancing the photo-curing reaction of the pressure-sensitive adhesive composition before the light irradiation treatment, its cured product, and the pressure-sensitive adhesive layer. Has the function of suppressing From this, by adding the component (G), it is possible to store the adhesive composition, its cured product, and the adhesive layer in an environment where weak light (for example, ultraviolet rays) is irradiated, for example, under LED lighting. Therefore, the storability can be improved. On the other hand, since the amount of irradiation light during light irradiation is large, a large amount of radicals are generated during light irradiation, and the stabilizing effect of the component (G) cannot catch up. As a result, the photocuring reaction at the time of light irradiation proceeds even in the presence of the component (G), and the adhesive strength of the adhesive layer can be reduced. In the specification of the present application, the term "stabilizer" means any one of an antioxidant, a light stabilizer, a polymerization inhibitor and an ultraviolet absorber.

The component (G) is not particularly limited as long as it is an antioxidant, a light stabilizer, a polymerization inhibitor or an ultraviolet absorber, and known ones can be used. Among these, antioxidants and light stabilizers are preferable.

Examples of antioxidants include hindered phenol-based antioxidants and phosphorus-based antioxidants.

The hindered phenol-based antioxidant is not particularly limited, and examples thereof include compounds having a sterically hindered hydroxyphenyl group. Here, the sterically hindered hydroxyphenyl group is not particularly limited as long as it is a bulky and substituted hydroxyphenyl group. Examples thereof include those having a substituted or unsubstituted alkyl group at the 2-position and the 6-position of the hydroxyphenyl group, but are not limited thereto. Examples of the hindered phenol antioxidant include triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], pentaerythritol-tetrakis[3-(3,5). -Di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, thiodiethylene-bis[3-(3,5-di) -T-butyl-4-hydroxyphenyl)propionate], benzenepropionic acid, 3,5-bis(1,1-dimethyl)-4-hydroxy-C7-C9 branched alkyl ester, 4,6-bis(dodecylthiomethyl) )-O-Cresol, 3,3′,3″,5,5′,5″-hexa-t-butyl-α,α′,α″-(mesitylene-2,4,6-triyl)tri-p -Cresol, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,6-di-t-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol, 1,6-hexanediol-bis[3-(3,3 5-di-t-butyl-4-hydroxyphenyl)propionate], ethylenebis(oxyethylene)bis[3-(5-t-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene-bis[3 -(3,5-di-t-butyl-4-hydroxyphenyl)propionate], isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 1,3,5-trimethyl- 2,4,6-Tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methyl) (Phenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, N,N'-hexane-1,6-diylbis[3-(3,3 5-di-t-butyl-4-hydroxyphenyl)propionamide], N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), N,N'- Bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyl]hydrazine, diethyl[(3,5-bis(1,1-dimethylethyl)-4-hi] Droxyphenyl)methyl]phosphate, 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 3,3′,3″,5,5′,5″-hexa-t -Butyl-a,a',a''-(mesitylene-2,4,6-triyl)tri-p-cresol, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butyl) Phenyl)butane, 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethyl)isocyanuric acid, 1,3,5-tris(4-sec-butyl-3-hydroxy-2) ,6-Dimethyl)isocyanuric acid, 1,3,5-tris(4-neopentyl-3-hydroxy-2,6-dimethyl)isocyanuric acid, 2,2′-methylenebis(4-methyl-6-t-butylphenol) , 4,4'-butylidene bis(4-methyl-6-t-butylphenol), tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, tris-(3,5-di- t-butyl-4-hydroxybenzyl)-isocyanurate, polycondensate of p-chloromethylstyrene and p-cresol, polycondensate of p-chloromethylstyrene and divinylbenzene, p-cresol and divinylbenzene polycondensate Examples include isobutylene reaction products.

Examples of the phosphorus-based antioxidant include triphenylphosphite, tris(2,4-di-t-butylphenyl)phosphite, diphenyloctylphosphite, diphenylisodecylphosphite, phenyldiisodecylphosphite, tetrakis(2 ,4-Di-t-butylphenyl)-4,4'-biphenylene phosphite, trisnonylphenyl phosphite, bis(2,4-di-t-butylphenyl) pentaerythritol diphosphite, distearyl pentaerythritol di Phosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite, bis(2,4 -Dicumylphenyl)pentaerythritol-diphosphite, tetrakis(2,4-di-t-butylphenyl)(1,1-biphenyl)-4,4'-diylbisphosphonite, di-t-butyl-m-cresyl -Phosphonite, distearyl pentaerythritol diphosphite, di(2,4-di-t-butylphenyl)-pentaerythril diphosphite, di(2,6-di-t-butyl-4-methylphenyl)- Pentaerythril diphosphite, 4,4′-butylidene-bis(3-methyl-6-t-butylphenyl-ditridecyl)phosphite, cyclic neopentanetetrayl (octadecylphosphite), diisodecyl pentaerythritol diphosphite , 2,2-methylenebis(4,6-di-t-butylphenyl)octylphosphite, bis(tridecyl)pentaerythritol diphosphite, bis(nonylphenyl)pentaerythritol diphosphite, hydrogenated bisphenol A pentaerythritol phosphite Phytopolymer, hydrogenated bisphenol A phosphite polymer, tetraphenyltetra(tridecyl)pentaerythritol tetraphosphite, tetra(tridecyl)-4,4′-isopropylidene diphenyldiphosphite, tetraphenyldipropylene glycol diphosphite, etc. Can be mentioned.

Examples of the light stabilizer include hindered amine light stabilizers (HALS) and the like.

The hindered amine light stabilizer (HALS) is not particularly limited, and examples thereof include compounds having a sterically hindered piperidyl group. Here, the sterically hindered piperidyl group is not particularly limited as long as it is a bulky and substituted piperidyl group. Examples thereof include those having 1 or more and 2 or less alkyl groups at the 2- and 6-positions of the piperidyl group, but are not limited thereto. Examples of the hindered amine light stabilizer (HALS) include bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate and methyl(1,2,2,6,6-pentamethyl-4-piperidinyl). ) Sebacate, 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)amino]-6-(2-hydroxyethylamine)-1 ,3,5-Triazine, decanedioic acid bis(2,2,6,6-tetramethyl-1-(octyloxy)-4-piperidinyl) ester, bis(1,2,2,6,6-pentamethyl-4) -Piperidinyl)-2-butyl-2-(4-hydroxy-3,5-di-t-butylbenzyl)propanedioate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, 4 -(Meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloyloxy-1,2 ,2,6,6-Pentamethylpiperidine, 4-(meth)acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-cyano-4-(meth)acryloylamino-2,2,6 ,6-Tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,6-tetramethylpiperidine, 1-(meth)acryloyl- 4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 1-(meth)acryloyl-4-cyano-4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine , 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine and the like.

Examples of the polymerization inhibitor include hydroquinone, hydroquinone monomethyl ether, benzoquinone, pt-butylcatechol, 2,6-dibutyl-4-methylphenol and the like.

Examples of the ultraviolet absorber include benzophenone-based ultraviolet absorbers such as 2,4-dihydroxy-benzophenone and 2-hydroxy-4-methoxy-benzophenone. Further, for example, benzotriazole-based ultraviolet absorption such as 2-(2′-hydroxy-5-methylphenyl)benzotriazole and 2-(2′-hydroxy-3′,5′-di-t-butylphenyl)benzotriazole Agents. Further, for example, 2,4-diphenyl-6-(2-hydroxy-4-methoxyphenyl)-1,3,5-triazine, 2,4-diphenyl-6-(2-hydroxy-4-ethoxyphenyl)- Examples thereof include triazine-based UV absorbers such as 1,3,5-triazine.

Among these, antioxidants or light stabilizers are preferable, and hindered phenol antioxidants or hindered amine light stabilizers (HALS) are more preferable. Then, pentaerythritol-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate, methyl( More preferred is 1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate.

The component (G) may be a synthetic product or a commercially available product. Examples of commercially available products include hindered phenol antioxidants such as Irganox (registered trademark) 1010, 1010FF, 1035, 1035FF (W&C), 1076, 1076FD, 1098, 1135, 1330, 1530L, manufactured by BASF Japan Ltd. 1726, 245, 245FF, 259, 3114, 565 and the like. Moreover, the hindered amine light stabilizer (HALS) is, for example, BASF Japan Ltd. Tinuvin (registered trademark) 111 FDL, 123, 144, 292, 5100, 123-DW, 622 SF, PA 144, 765, 770DE, XT 55 FB, 783 FDL, 791 FB, Chimassorb (registered trademark) 2020 FDL, 944 FDL, 944 LD and the like can be mentioned.

The antioxidant, light stabilizer, polymerization inhibitor or ultraviolet absorber may be used alone or in combination of two or more kinds. When two or more kinds are used, two or more kinds of the same series may be combined, or one or more kinds of different series may be combined.

As commercial products relating to combinations of different systems, for example, a blend of an ultraviolet absorber and a hindered amine light stabilizer (HALS) is, for example, Tinuvin (registered trademark) 5050, 5060, 5151, 5333 manufactured by BASF Japan Ltd. -DW and the like.

The content of the component (G) in the pressure-sensitive adhesive composition (when two or more kinds are contained, the total amount thereof) is not particularly limited. However, in order to obtain the above effects of the component (G) more favorably, the content of the component (G) should not exceed 5 parts by mass relative to 100 parts by mass of the component (A), that is, (G) The content of the component) is preferably 5 parts by mass or less. When the content of the component (G) exceeds 5 parts by mass, the amount of radicals stabilized by the component (G) increases, and the progress of the photocuring reaction during light irradiation may be suppressed. .. Further, the content of the component (G) is more preferably 3 parts by mass or less, and even more preferably 0.5 part by mass or less, relative to 100 parts by mass of the component (A). Within the above range, the effect of lowering the adhesive strength of the adhesive layer after the light irradiation treatment is not affected. Further, the pressure-sensitive adhesive composition contains the component (G), that is, the content of the component (G) in the pressure-sensitive adhesive composition (the total amount when two or more kinds are contained) is 100 parts by mass of the component (A). It is preferable that the amount is more than 0 parts by mass. This is because radicals generated under an environment where weak light (for example, ultraviolet rays) of the adhesive layer is irradiated, for example, under LED illumination can be stabilized. Further, the content of the component (G) is more preferably 0.01 parts by mass or more and even more preferably 0.05 parts by mass or more with respect to 100 parts by mass of the component (A). Within the above range, the storability of the pressure-sensitive adhesive layer under the environment where weak light (for example, ultraviolet rays) is irradiated, for example, under LED illumination, is further improved. From this, when the pressure-sensitive adhesive composition contains the component (G), an example of a preferable range of the content thereof is more than 0 parts by mass and 5 parts by mass or less with respect to 100 parts by mass of the component (A). ..

[Other ingredients]
The pressure-sensitive adhesive composition according to one aspect of the present invention may further contain known additives unless the effects of the present invention are impaired. The additive is not particularly limited. For example, curing accelerators, lithium salts, fillers, softeners, anti-aging agents, tackifying resins, leveling agents, defoamers, plasticizers, dyes, pigments, treatment agents, optical brighteners, dispersants, lubricants, etc. Are listed.

[Method for preparing adhesive composition]
The method for producing the pressure-sensitive adhesive composition according to one aspect of the present invention (production method) is not particularly limited, and a known method can be used. The pressure-sensitive adhesive composition according to one aspect of the present invention can be usually obtained by mixing the above-mentioned components. The mixing method is also not particularly limited. Examples of the mixing method include a method of mixing the components all at once, a method of sequentially adding the respective components and mixing, or a method of mixing arbitrary plural components and then mixing the remaining components. After mixing, it is preferable to carry out stirring so as to form a uniform mixture. The stirring may be carried out, if necessary, at a place where light of a specific wavelength is shielded, until it becomes uniform with a stirrer or the like. If necessary, the mixture may be heated and stirred with a stirrer or the like until uniform. Here, the stirring time is not particularly limited, and examples thereof include 10 minutes or more and 5 hours or less. Further, when heating is performed, the temperature after heating is not particularly limited, and examples thereof include 30° C. or higher and 40° C. or lower.

Another aspect of the present invention relates to a pressure-sensitive adhesive composition solution containing the pressure-sensitive adhesive composition described above and a solvent. In the present specification, a solution or dispersion containing the above-mentioned pressure-sensitive adhesive composition and a solvent is referred to as “pressure-sensitive adhesive composition solution”. Here, the pressure-sensitive adhesive composition solution may be used for improving the homogenization of the pressure-sensitive adhesive composition by mixing, or may be used as a coating liquid for forming a pressure-sensitive adhesive layer described later.

It is preferable to use a solvent (solvent or dispersion medium) when preparing the pressure-sensitive adhesive composition or when preparing the coating liquid. The solvent is not particularly limited, but an organic solvent is preferable. The organic solvent is not particularly limited. For example, toluene, ethyl acetate, butyl acetate, methyl ethyl ketone, hexane, acetone, cyclohexanone, 3-pentanone, acetonitrile, propionitrile, isobutyronitrile, valeronitrile, dimethyl sulfoxide, dimethylformamide and the like can be mentioned. Among these, methyl ethyl ketone or ethyl acetate is preferable. The organic solvent may be used alone or in combination of two or more kinds.

The concentration of the pressure-sensitive adhesive composition in the pressure-sensitive adhesive composition solution is not particularly limited, but it is preferably 20% by mass or more and 99% by mass or less based on the total mass of the pressure-sensitive adhesive composition solution. The concentration of the pressure-sensitive adhesive composition is more preferably 30% by mass or more and 95% by mass or less based on the total mass of the pressure-sensitive adhesive composition solution. Within the above range, the drying property of the pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive composition is further improved, and the coatability when used as a coating liquid is further improved.

The preparation of the pressure-sensitive adhesive composition and the pressure-sensitive adhesive composition solution, and the storage thereof are preferably performed in a light-shielding environment. For example, when the adhesive strength of the pressure-sensitive adhesive composition is reduced by irradiation with ultraviolet rays, it is preferable to prepare and store under an ultraviolet-shielding environment, for example in a yellow room. This is because the progress of the photo-curing reaction of the pressure-sensitive adhesive composition can be further suppressed, and the effect of lowering the adhesive strength of the pressure-sensitive adhesive layer after light irradiation can be further improved.

<Adhesive layer and manufacturing method thereof>
Another aspect of the present invention relates to a cured product of the pressure-sensitive adhesive composition. Yet another embodiment of the present invention also relates to a pressure-sensitive adhesive layer composed of a cured product of the above-mentioned pressure-sensitive adhesive composition. Here, as described above, the pressure-sensitive adhesive composition is preferably a thermosetting pressure-sensitive adhesive composition, and the cured product is preferably a thermosetting product.

Note that, as described above, the thermosetting product is a cured product formed by the progress of the crosslinking reaction by heat. The heat-cured product does not necessarily require heating, and includes a cured product cured at room temperature (20° C. or higher and 25° C. or lower).

The adhesive force of the cured product according to one embodiment of the present invention is reduced by light irradiation. Therefore, the pressure-sensitive adhesive layer according to one aspect of the present invention exhibits remarkably excellent reworkability by performing light irradiation treatment while exhibiting extremely good pressure-sensitive adhesiveness in a pressure-sensitive adhesive state. Here, the ratio of the adhesive force after light irradiation with respect to the adhesive force before the light irradiation treatment of the adhesive film according to one embodiment of the present invention is in the same range as the ratio of the adhesive force after the light irradiation treatment of the adhesive film described below. Is preferred.

The adhesive force of the adhesive layer according to one aspect of the present invention is preferably in the same range as the adhesive force of the adhesive film described below from the viewpoint of achieving both adhesiveness and reworkability. The adhesive force can be measured by using a tensile tester, and the details of the measuring method will be described in Examples.

In addition, the adhesive force of the pressure-sensitive adhesive layer according to one embodiment of the present invention after the light irradiation treatment is preferably in the same range as the adhesive force of the adhesive film described below after the light irradiation treatment from the viewpoint of reworkability. The adhesive strength after the light irradiation treatment can be measured using a tensile tester, and the details of the measuring method will be described in the examples. The preferable ranges of irradiation light and irradiation energy in the light irradiation treatment of the pressure-sensitive adhesive layer are the same as the preferable conditions of the light irradiation treatment of the pressure-sensitive adhesive film described later, respectively.

The method for forming the pressure-sensitive adhesive layer is not particularly limited, and a known method can be used. It is preferable that the pressure-sensitive adhesive composition itself or the pressure-sensitive adhesive composition solution is applied on a support, and the coating film formed is subjected to heat drying treatment or heat treatment as necessary.

Further, the coating thickness of the pressure-sensitive adhesive composition (thickness after drying, thickness of pressure-sensitive adhesive layer) is not particularly limited. The thickness may be selected depending on the use of the pressure-sensitive adhesive layer, the type of the base material when used as a pressure-sensitive adhesive film, and the like. The thickness is preferably 1 μm or more and 500 μm or less. Further, the thickness is more preferably 10 μm or more and 300 μm or less, and further preferably 20 μm or more and 200 μm or less.

The coating method is not particularly limited, and a known method can be used. For example, natural coater, knife belt coater, floating knife, knife over roll, knife on blanket, spray, dip, kiss roll, squeeze roll, reverse roll, air blade, curtain flow coater, doctor blade, wire bar, die coater, comma coater. , A baker applicator, a gravure coater and the like.

When the pressure-sensitive adhesive composition itself is used for forming the pressure-sensitive adhesive layer, the heat treatment temperature of the pressure-sensitive adhesive composition is not particularly limited. The thermosetting pressure-sensitive adhesive composition is not particularly limited as long as it is a temperature at which the progress of the crosslinking reaction is sufficient. The heat treatment temperature is preferably 20° C. or higher and 150° C. or lower, and more preferably 40° C. or higher and 150° C. or lower. The heat treatment temperature is more preferably 50°C or higher and 140°C or lower, and particularly preferably 80°C or higher and 130°C or lower. Further, in this case, the heat treatment time of the pressure-sensitive adhesive composition is not particularly limited. The thermosetting pressure-sensitive adhesive composition is not particularly limited as long as the crosslinking reaction can proceed sufficiently. The heat treatment time is preferably 5 seconds or more and 20 minutes or less, more preferably 30 seconds or more and 10 minutes or less, and further preferably 1 minute or more and 7 minutes or less. If it is a thermosetting pressure-sensitive adhesive composition, by setting the heating conditions in the above range, the crosslinking reaction of the pressure-sensitive adhesive composition can be more appropriately progressed, and a pressure-sensitive adhesive layer having better adhesive strength is obtained. be able to.

When the pressure-sensitive adhesive composition solution is used for forming the pressure-sensitive adhesive layer, the heat-drying treatment temperature of the pressure-sensitive adhesive composition solution is not particularly limited. The thermosetting pressure-sensitive adhesive composition is not particularly limited as long as it is a temperature at which the progress of the crosslinking reaction is sufficient. The heat drying treatment temperature is preferably 40° C. or higher and 150° C. or lower, more preferably 50° C. or higher and 140° C. or lower, and further preferably 80° C. or higher and 130° C. or lower. Further, in this case, the heat drying treatment time is not particularly limited. The thermosetting pressure-sensitive adhesive composition is not particularly limited as long as the crosslinking reaction can proceed sufficiently. The heat-drying treatment time is preferably 5 seconds or more and 20 minutes or less, more preferably 30 seconds or more and 10 minutes or less, and further preferably 1 minute or more and 7 minutes or less. The solvent can be sufficiently removed by setting the heating and drying treatment condition to the above range. Moreover, if it is a thermosetting adhesive composition, the crosslinking reaction of an adhesive composition can be advanced more appropriately and the adhesive layer which has more favorable adhesive force can be obtained.

When forming the pressure-sensitive adhesive layer, it is preferable to further perform aging treatment after coating and heat treatment or heat drying treatment. By performing the aging treatment, the crosslinking reaction of the pressure-sensitive adhesive composition can be more appropriately progressed, and a pressure-sensitive adhesive layer having better adhesive strength can be obtained. The aging treatment conditions are not particularly limited, and known conditions in the method for producing a pressure-sensitive adhesive layer can be adopted. The aging treatment temperature is preferably 10° C. or higher and 40° C. or lower, and more preferably room temperature (20° C. or higher and 25° C. or lower). The aging treatment humidity is preferably 10% RH or more and 80% RH or less relative humidity, and preferably 40% RH or more and 50% RH or less. The aging treatment time is preferably 1 day or more and 7 days or less. From this, as an example of preferable aging treatment conditions, aging treatment is carried out for 7 days in an environment of 23° C. and 50% RH. By setting the aging treatment conditions within the above range, the crosslinking reaction of the pressure-sensitive adhesive composition can be more appropriately progressed, and a pressure-sensitive adhesive layer having better adhesive strength can be obtained.

The aging treatment is preferably performed in a state where a support, a coating film after heating and drying, and a release film described below are laminated in this order.

The pressure-sensitive adhesive layer is preferably formed and stored in a light-shielding environment. For example, when the adhesive strength of the pressure-sensitive adhesive composition and the cured product thereof is reduced by irradiation with ultraviolet rays, it is preferable to perform formation and storage under an ultraviolet-shielding environment, for example, in a yellow room. This is because it is possible to further suppress the progress of the photocuring reaction of the pressure-sensitive adhesive composition and its cured product, and to further improve the effect of lowering the pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer after light irradiation.

<Adhesive film>
Another aspect of the present invention relates to an adhesive film including a substrate and an adhesive layer composed of a cured product of the adhesive composition (that is, the above-mentioned adhesive layer). That is, it can be said that the form is an adhesive film including a base material and an adhesive layer composed of a cured product of the adhesive composition. Here, as described above, the pressure-sensitive adhesive composition is preferably a thermosetting pressure-sensitive adhesive composition, and the cured product is preferably a thermosetting product. The details of the pressure-sensitive adhesive layer are as described above.

The adhesive film is preferably a surface protective film. The surface protection film is a film that is attached to the surface of a member such as various optical parts and various substrates for the purpose of surface protection during the manufacturing process of the product or until the final product is used.

The pressure-sensitive adhesive layer is arranged on at least one surface of the base material directly or via another member. Among these, the pressure-sensitive adhesive layer is preferably arranged only on one surface of the substrate, directly or through another member.

The base material is not particularly limited, and known materials can be used. Of these, a resin film is preferable. This is because the resin film is excellent in properties required for adhesive film applications, particularly surface protection film applications, such as high surface protection, good handleability, and high transparency. The resin that constitutes the resin film is not particularly limited, and known resins can be used. Here, the "film containing a resin as a main component" means that the content of the resin of interest is 50% by mass or more based on the total mass of the resin film. Here, the content of the resin of interest is preferably 70% by mass or more, and more preferably 80% by mass or more, based on the total mass of the resin film. The content of the resin of interest is more preferably 90% by mass or more, and particularly preferably 95% by mass or more (upper limit 100% by mass) based on the total mass of the resin film.

Examples of the resin constituting the resin film include a film containing a resin such as a polyester resin, a cellulose resin, a polycarbonate resin, an acrylic resin, a styrene resin, an olefin resin, or a polyamide resin as a main component. To be Examples of the polyester resin include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, and the like. Examples of the cellulosic resin include diacetyl cellulose and triacetyl cellulose. Examples of the acrylic resin include polymethyl (meth)acrylate and the like. Examples of the styrene resin include polystyrene and acrylonitrile-styrene copolymer. Examples of the olefin resin include polyethylene, polypropylene, polyolefin having a cyclic structure (preferably a norbornene structure), and ethylene-propylene copolymer. Examples of the polyamide resin include nylon 6, nylon 6,6, and aromatic polyamide. Among these, a film containing a polyester resin as a main component (polyester resin film) is preferable. Further, a film containing polyethylene terephthalate as a main component (polyethylene terephthalate film, PET film) is more preferable. The resin material forming the resin film may be used alone or in combination of two or more kinds.

The film thickness of the base material is not particularly limited, but is preferably 10 μm or more and 500 μm or less. Further, the film thickness of the base material is more preferably 20 μm or more and 200 μm or less, and further preferably 40 μm or more and 100 μm or less.

The base material may be surface-treated. The surface treatment is not particularly limited, and a known method can be used.

The adhesive film may further have other members in addition to the base material and the adhesive layer. The other member is not particularly limited, and various members included in the known pressure-sensitive adhesive layer can be used. For example, an intermediate layer provided between the base material and the pressure-sensitive adhesive layer, a release film bonded to the surface of the pressure-sensitive adhesive layer opposite to the base material side, and the like can be mentioned. Of these, a release film is preferable. The intermediate layer and the release film are not particularly limited, and known materials used in the adhesive film field can be used.

Examples of the release film include those obtained by treating the surface of a polyethylene terephthalate film with a silicone release agent. Examples of commercially available release films include DIAFOIL (registered trademark) MRF38 manufactured by Mitsubishi Plastics Co., Ltd., and the like.

The method for producing the pressure-sensitive adhesive film according to one aspect of the present invention is not particularly limited, and a known method can be used. It is a method of applying the above-mentioned pressure-sensitive adhesive composition itself, or the above-mentioned pressure-sensitive adhesive composition solution on a substrate, and subjecting the formed coating film to heat drying treatment or heat treatment, if necessary. preferable.

From this, a preferred example of the pressure-sensitive adhesive film according to one aspect of the present invention has a resin film and a pressure-sensitive adhesive layer that is disposed on one surface of the resin film and is composed of a cured product of the above-mentioned pressure-sensitive adhesive composition. , A surface protection film.

The production and storage of the adhesive film are preferably performed in a light-shielded environment. For example, when the pressure-sensitive adhesive strength of the pressure-sensitive adhesive composition and its cured product is reduced by irradiation with ultraviolet rays, it is preferable to carry out production and storage in an ultraviolet-shielding environment, for example, in a yellow room. This is because it is possible to further suppress the progress of the photocuring reaction of the pressure-sensitive adhesive composition and its cured product, and to further improve the effect of lowering the pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer after light irradiation.

Further, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive film according to one aspect of the present invention has a reduced adhesive force due to the light irradiation treatment. Therefore, the pressure-sensitive adhesive film according to one aspect of the present invention exhibits remarkably excellent reworkability by performing light irradiation treatment during rework while exhibiting extremely good tackiness in the tacky state. The ratio of the adhesive force after the light irradiation treatment to the adhesive force before the light irradiation treatment of the adhesive film according to one embodiment of the present invention is not particularly limited as long as it is less than 100%. From the viewpoint of reworkability, the smaller the value, the more preferable. When the adherend is glass, the proportion of the pressure-sensitive adhesive film according to one embodiment of the present invention, particularly the surface protection film, is preferably 0% or more and 75% or less. Further, the ratio is more preferably 0% or more and 55% or less, and further preferably 0% or more and 35% or less. Further, the ratio is more preferably 0% or more and 30% or less. And it is especially preferable that the said ratio is 0% or more and 20% or less.

The adhesive strength of the adhesive film according to one aspect of the present invention before the light irradiation treatment is not particularly limited. When the adherend is glass, the adhesive force of the pressure-sensitive adhesive film according to one embodiment of the present invention, particularly the surface protective film, is preferably 5 g/25 mm or more and 20 g/25 mm or less. Further, the adhesive force is more preferably 6 g/25 mm or more and 15 g/25 mm or less, and further preferably 8 g/25 mm or more and 13 g/25 mm or less. Within the above range, the adhesiveness and reworkability of the adhesive film are compatible at a higher level. The adhesive force can be measured by using a tensile tester, and the details of the measuring method will be described in Examples.

The adhesive force of the pressure-sensitive adhesive film according to one embodiment of the present invention after the light irradiation treatment is not particularly limited as long as it is a value smaller than that before the light irradiation treatment. From the viewpoint of reworkability, the smaller the adhesive strength, the more preferable. When the adherend is glass, the pressure-sensitive adhesive film according to one embodiment of the present invention, in particular, the pressure-sensitive adhesive force of the surface protective film is particularly limited as long as it is a value lower than the pressure-sensitive adhesive force of the pressure-sensitive adhesive film before light irradiation. However, it is preferably less than 5 g/25 mm. Further, the adhesive force is more preferably 3 g/25 mm or less, further preferably 2.5 g/25 mm or less (lower limit 0 g/25 mm). The adhesive strength after the light irradiation treatment can be measured using a tensile tester, and the details of the measuring method will be described in the examples.

Irradiation light in the light irradiation treatment is not particularly limited as long as it can promote photopolymerization and crosslinking of the component (B) by the component (E). The irradiation light can be appropriately selected depending on the types of the component (E) and the component (B). Among these, ultraviolet rays are preferable, and ultraviolet rays having a wavelength of 200 nm or more and 400 nm or less are more preferable, from the viewpoints of good controllability and handleability, and cost.

The light irradiation device is not particularly limited, and a known device can be used. In the case of the ultraviolet irradiation treatment, for example, a light source such as a metal halide lamp, a high pressure mercury lamp, a UV-LED lamp, a low pressure mercury lamp, a xenon arc lamp, a carbon arc lamp, an excimer lamp and a UV light laser can be mentioned.

The amount of light irradiation energy is not particularly limited. For ultraviolet irradiation treatment, ultraviolet irradiation energy is preferably 50 mJ / cm ² or more 5000 mJ / cm ² or less. In this case, the ultraviolet irradiation energy is more preferably 100 mJ / cm ² or more 3000 mJ / cm ² or less, and more preferably 300 mJ / cm ² or more 1500 mJ / cm ² or less.

In the pressure-sensitive adhesive film according to an aspect of the present invention, the adhesive strength before UV irradiation after the LED stability test (adhesive strength after LED stability test) is the same as before the ultraviolet ray irradiation when manufactured and stored under an ultraviolet shielding environment. It is preferable that the adhesive strength does not change. Here, in the LED stability test, the adhesive film manufactured and stored under an ultraviolet shielding environment is left for 15 days (360 hours) under a test environment of 23° C.×50% RH and LED illumination (500 Lux). To do. A value obtained by dividing the value of the adhesive strength after the LED stability test by the value of the adhesive strength before irradiation with ultraviolet rays when manufactured and stored in an ultraviolet-shielding environment is defined as the adhesive strength ratio. When the adherend is glass, the adhesive force ratio (glass adhesive force ratio) of the pressure-sensitive adhesive film according to one embodiment of the present invention, particularly the surface protection film, is not particularly limited, but is 0.8 or more and 1.2 or less. It is preferable.

In the pressure-sensitive adhesive film according to one aspect of the present invention, the adhesive strength after UV irradiation after the LED stability test (adhesive strength after UV treatment after the LED stability test) is the same as the ultraviolet light after being manufactured and stored in an ultraviolet shielding environment. It is preferable that there is no change from the adhesive strength after ultraviolet irradiation when the irradiation treatment is performed. Here, in the LED stability test, the adhesive film manufactured and stored under an ultraviolet shielding environment is left for 15 days (360 hours) under a test environment of 23° C.×50% RH and LED illumination (500 Lux). To do. The value of the adhesive strength after UV treatment after the LED stability test is divided by the adhesive strength value after UV irradiation when the UV irradiation treatment is performed after manufacturing and storage in an ultraviolet shielding environment, The latter is the adhesive strength ratio. When the adherend is glass, the adhesive force ratio of the pressure-sensitive adhesive film according to one embodiment of the present invention, particularly the surface protective film after ultraviolet irradiation (glass adhesive force ratio after ultraviolet irradiation) is not particularly limited, but 1. It is preferably 2 or less (lower limit 0).

The peeling electrification voltage of the pressure-sensitive adhesive film according to one aspect of the present invention is not particularly limited. The absolute value of the peeling withstand voltage is preferably as small as possible, from the viewpoint that the adhesive film after peeling is not charged and is excellent in workability. The absolute value of the peeling electrification voltage of the pressure-sensitive adhesive film according to one aspect of the present invention, particularly the surface protection film, is preferably 10 kV or less. Further, the absolute value is more preferably 2 kV or less, further preferably 0.5 kV or less. Further, the absolute value is more preferably 0.3 kV or less, and particularly preferably 0.2 kV or less (lower limit 0 kV). The peeling electrification voltage can be measured by using a potentiometer, and the details of the measuring method will be described in Examples.

The pressure-sensitive adhesive film according to one aspect of the present invention preferably has high transparency. The transparency can be evaluated mainly by the transmittance and the HAZE.

The transmittance of the pressure-sensitive adhesive film according to one aspect of the present invention is not particularly limited. The transmittance is preferably as close to 100% as possible, from the viewpoint that the inspection can be carried out more accurately with the adhesive film stuck. The transmittance of the pressure-sensitive adhesive film according to one embodiment of the present invention, particularly the surface protection film, is preferably 85% or more, more preferably 90% or more (upper limit 100%). The transmittance can be measured using a haze meter, and the details of the measuring method will be described in Examples.

Haze of the adhesive film according to one embodiment of the present invention is not particularly limited. The smaller the value of Haze, the more preferable it is, from the viewpoint that the inspection can be performed more accurately with the adhesive film stuck. The HAZE of the pressure-sensitive adhesive film according to one embodiment of the present invention, particularly the surface protection film, is preferably 3% or less, more preferably 2% or less (lower limit 0%). Haze can be measured using a haze meter, and the details of the measuring method will be described in Examples.

The effects of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples.

A thermosetting pressure-sensitive adhesive composition was prepared according to the following procedure. Hereinafter, the preparation and storage of the thermosetting pressure-sensitive adhesive composition, and the production and evaluation of the surface protection film were all carried out in a yellow room that shields ultraviolet rays. That is, the thermosetting pressure-sensitive adhesive composition and the surface protective film were present in an ultraviolet-shielding environment from their preparation until the evaluation was completed, except when they were intentionally exposed to ultraviolet rays in the following evaluation.

<Preparation of adhesive composition>
[Preparation of Thermosetting Adhesive Composition 1]
(A) Component manufactured by Negami Kogyo Co., Ltd. Product name: ART Resin (registered trademark) UN5500P 100 parts by mass, TMPTA 35 parts by mass as the component (B), Asahi Kasei Co., Ltd. as the component (C) Product name: Duranate (registered trademark) D101 5.3 parts by mass, and Asahi Kasei Corporation trade name: Duranate (registered trademark) E402-80B 3.9 parts by mass, Negami Kogyo Co., Ltd. SE-010T 1 part by mass as a component (D). , (E) manufactured by IGM Resins, trade name: Omnirad (registered trademark) TPO H 1 part by mass, (F) component manufactured by 3M Japan Co., Ltd. trade name: 3M (trademark) ionic liquid type antistatic agent FC4400 2 parts by mass Parts were mixed to prepare a thermosetting pressure-sensitive adhesive composition 1. Then, the pressure-sensitive adhesive composition solution 1 was prepared by adding ethyl acetate so that the concentration of the thermosetting pressure-sensitive adhesive composition (concentration of the total amount of each component) was 50% by mass.

[Preparation of Thermosetting Adhesive Compositions 2 to 23]
In the preparation of the thermosetting adhesive composition 1, each thermosetting adhesive composition was prepared by changing the type and addition amount of each component as shown in Tables 1 to 3 below. Then, each pressure-sensitive adhesive composition solution was prepared in the same manner as the preparation of the thermosetting pressure-sensitive adhesive composition 1.

The formulations of each thermosetting adhesive composition are shown in Tables 1 to 3 below. In the table, the NCO group represents an isocyanate group. The details of each component are shown below in Tables 1 to 3. In addition, the components not shown in Table 3 were not used in the preparation of each thermosetting pressure-sensitive adhesive composition shown in Table 3.

[Component (A): Urethane Prepolymer Having Two or More Hydroxyl Groups]
A1: Art Resin (registered trademark) UN5500P (urethane prepolymer having hydroxyl groups at both ends and having an acryloyloxy group in the side chain and having a polyether skeleton), manufactured by Negami Kogyo Co., Ltd.;
[(B) component: polyfunctional (meth)acrylate]
B1: TMPTA (trimethylolpropane triacrylate, hydroxyl value 0 mgKOH/g).

[Component (C): Crosslinking agent]
C1: Duranate (registered trademark) D101 (bifunctional isocyanate (HDI)), manufactured by Asahi Kasei Co., Ltd.;
C2: Duranate (registered trademark) E402-80B (elastic type trifunctional isocyanate), manufactured by Asahi Kasei Co., Ltd.;
C3: Perloyl (registered trademark) TCP (bis(4-t-butylcyclohexyl peroxydicarbonate)), manufactured by NOF CORPORATION.

[(D) component: crosslinked particles]
D1:SE-010T ((meth)acrylic crosslinked particles, acrylic crosslinked beads, average particle diameter 10 μm), manufactured by Negami Kogyo Co., Ltd.;
D2: SE-020T ((meth)acrylic crosslinked particles, acrylic crosslinked beads, average particle size 19 μm), manufactured by Negami Kogyo Co., Ltd.;
D3: X-52-854 (silicone-based crosslinked particles, silicone resin powder, average particle size 0.7 μm), manufactured by Shin-Etsu Chemical Co., Ltd.

[Component (E): Photoradical Initiator]
E1: Omnirad® TPO H (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide), manufactured by IGM Resins.

[Component (F): Antistatic agent]
F1: 3M (trademark) ionic liquid type antistatic agent FC4400 (tri-n-butylmethylammonium bistrifluoromethanesulfonimide), manufactured by 3M Japan Co., Ltd.

[Component (G): Stabilizer]
G1: Irganox (registered trademark) 1010 (pentaerythritol-tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], hindered phenolic antioxidant), manufactured by BASF Japan Ltd.;
G2: Tinuvin® 292 (bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate and methyl (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate. Mixture, hindered amine light stabilizer (HALS), manufactured by BASF Japan Ltd.

<Production of surface protection film (adhesive film)>
[Production of surface protection film 1]
A polyethylene terephthalate (PET) film having a thickness of 75 μm and having an AS treatment (antistatic treatment) on one surface was prepared. The pressure-sensitive adhesive composition solution prepared above was applied to the surface of the PET film opposite to the AS-treated surface so that the thickness after drying was 75 μm. Next, the coating film on the PET film was dried in a hot air circulation type oven at 120° C. for 5 minutes to form an adhesive layer on the PET film. Subsequently, a release film (Diafoil (registered trademark) MRF38 (a surface of a PET film having a thickness of 38 μm) was treated with a silicone release agent on the surface of the pressure-sensitive adhesive layer (the surface opposite to the surface on the PET film side). Stuff), manufactured by Mitsubishi Plastics Co., Ltd.). Then, the PET film, the pressure-sensitive adhesive layer, and the release film were laminated in this order, and the laminate was left for 7 days in a test environment of 23° C.×50% RH to produce the surface protective film 1.

[Production of surface protection films 2 to 23]
In the production of the surface protective film 1, each surface protective film was produced in the same manner except that the pressure sensitive adhesive composition solution 1 was changed to the pressure sensitive adhesive composition solutions 2 to 23.

<Evaluation 1 of surface protection film>
The following evaluation was performed about the produced surface protection films 1-18. The evaluation results are shown in Table 1 and Table 2 below.

[Glass adhesive strength (adhesiveness)]
The surface protection film obtained above was cut into a width of 25 mm and a length of 200 mm. Then, the pressure-sensitive adhesive layer surface of the surface protection film after peeling the release film and non-alkali glass (EAGLE XG (registered trademark), manufactured by Corning) were pressure-bonded. The pressure bonding was performed using a rubber roll having a mass of 2000 g (a roll having a width of 45 mm and a diameter (including the rubber layer) 95 mm covered with a rubber layer having a thickness of 6 mm, and a spring hardness of 80 Hs on the roll surface). After the pressure bonding, it was left for 3 hours, and the strength when the surface protective film was peeled off from the alkali-free glass was measured. The strength was measured under a test environment of 23° C.×50% RH using a tensile tester under the condition that the surface protection film was peeled from the alkali-free glass in the direction of 180° at a peeling speed of 2400 mm/min. .. And the value obtained by the said measurement was made into the glass adhesive force (g/25 mm) of a surface protection film. The glass adhesive strength was considered good when it was 5 g/25 mm or more and 20 g/25 mm or less.

[Glass adhesion after UV irradiation (reworkability)]
The surface protection film obtained above was cut into a width of 25 mm and a length of 200 mm. Next, the pressure-sensitive adhesive layer surface of the surface protection film after peeling the release film and non-alkali glass (EAGLE XG (registered trademark), manufactured by Corning) were pressure-bonded by the same method as in the evaluation of the glass adhesive strength. After the pressure-bonding, it was left for 3 hours, and then the surface protective film was irradiated with ultraviolet rays from the PET film side through the PET film to accelerate the curing of the pressure-sensitive adhesive layer. The ultraviolet irradiation was performed under a condition of 300 mJ/cm ² using a metal halide lamp in a test environment of 23° C.×50% RH. Then, the glass adhesive force was measured in the same manner as the measurement of the glass adhesive force. This value was taken as the glass adhesive strength (g/25 mm) of the surface protective film after ultraviolet irradiation. The glass adhesive strength after ultraviolet irradiation is not particularly limited as long as it is lower than the glass adhesive strength value, but is particularly good when it is less than 5 g/25 mm.

[Punching processability (frequency of the adhesive layer falling off)]
The release film was released from the surface protection film obtained above. Next, with reference to the scratch hardness test method described in JIS K5600-5-4:1999, the presence or absence of the adhesive residue was confirmed. Specifically, the presence or absence of adhesive residue was confirmed when a PEN made of SUS and having a tip of 1 mmφ was pressed against the surface of the adhesive layer at an angle of 45 degrees with a load of 500 g and 1000 g and was slid for 2 cm. It has been confirmed that the degree of occurrence of adhesive residue in the test corresponds to the frequency of occurrence of detachment of the adhesive layer during punching. Therefore, the test result can be used as an index of punching workability. The surface protection film was evaluated for punching workability according to the following criteria, and a good result was evaluated as follows:
(Evaluation criteria)
A: No adhesive residue was generated under a load of 1000 g,
◯: Adhesive residue was generated under a load of 1000 g, but no adhesive residue was generated under a load of 500 g,
Δ: An adhesive residue was generated in a part of the adhesive layer under a load of 500 g,
X: Adhesive residue was generated on the entire surface of the adhesive layer under a load of 500 g.

[Peeling electrification voltage]
Similarly to the measurement of the glass adhesive force, the surface protective film and the alkali-free glass (EAGLE XG (registered trademark), manufactured by Corning) were pressure-bonded. After the pressure bonding, it was left for 3 hours, and then the surface protective film was peeled off from the alkali-free glass in the same manner as in the measurement of the glass adhesive force. At this time, the potential of the surface protective film generated during peeling was measured. The measurement of the electric potential was performed using a potential measuring device (STATIRON (registered trademark) DZ4, manufactured by Shishido Electrostatic Co., Ltd.) fixed at a height of 30 mm from the center of the film under a test environment of 23° C. and 50% RH. It was The value obtained by the measurement was defined as the peeling electrification voltage (kV) of the surface protection film. The peeling electrification voltage is preferably as small as possible.

[Substrate contamination]
Soken Chemical Co., Ltd., which is an adhesive, trade name: SK Dyne (registered trademark) 2137, Soken Chemical Co., Ltd., a cross-linking agent, trade name: TD-75, and Soken Chemical Co., Ltd., which is an additive, trade name: A-50 was added to ethyl acetate as a solvent at a solid content ratio of 100/0.1/0.1 (mass ratio) to prepare a solution. Then, using the obtained solution, a pressure-sensitive adhesive was applied onto a substrate, manufactured by Toyobo Co., Ltd., trade name: Cosmoshine (registered trademark) A4300 (polyester film, thickness of 75 μm) so that the film thickness after drying was 25 μm. Layers were formed. Subsequently, a release film, release PET 38E0010BG manufactured by Fujimori Industry Co., Ltd. was attached to the surface of the pressure-sensitive adhesive layer opposite to the base material side. Then, the obtained substrate/adhesive layer/release film laminate was aged at room temperature for 1 week to prepare an adhesive sheet.

Similarly to the measurement of the glass adhesive force, the surface protective film and the alkali-free glass (EAGLE XG (registered trademark), manufactured by Corning) were pressure-bonded. Then, after being allowed to stand in an environment of 40° C. for 2 weeks, the surface protective film was peeled off from the non-alkali glass in the same manner as in the measurement of the glass adhesive force.

Next, the pressure-sensitive adhesive sheet prepared above was pressure-bonded to the surface of the new alkali-free glass and the release surface of the alkali-free glass after the surface protection film was removed. The pressure bonding was performed using a rubber roll having a mass of 2000 g (a roll having a width of 45 mm and a diameter (including the rubber layer) 95 mm covered with a rubber layer having a thickness of 6 mm, and a spring hardness of 80 Hs on the roll surface). Then, the strength when peeling the pressure-sensitive adhesive sheet from each of these alkali-free glasses was measured. The strength was measured under a test environment of 23° C.×50% RH using a tensile tester under the condition that the pressure-sensitive adhesive sheet was peeled from the alkali-free glass in the direction of 180° at a peeling speed of 300 mm/min. Then, the ratio of the strength (g/25 mm) when the pressure-sensitive adhesive sheet was peeled from the non-alkali glass after the surface protection film was peeled to the strength (g/25 mm) when the pressure-sensitive adhesive sheet was peeled from the new alkali-free glass ( %) was calculated. Then, the glass stain resistance of the surface protective film was evaluated according to the following criteria, and the following Δ evaluation or more was regarded as a good result:
(Evaluation criteria)
⊚: The ratio of strength (g/25 mm) when peeling the pressure-sensitive adhesive sheet from the alkali-free glass after peeling the surface protective film is 90% or more,
◯: Ratio of strength (g/25 mm) when peeling the pressure-sensitive adhesive sheet from the alkali-free glass after peeling the surface protective film is 80% or more and less than 90%,
Δ: The ratio of strength (g/25 mm) when peeling the pressure-sensitive adhesive sheet from the alkali-free glass after peeling the surface protective film is 70% or more and less than 80%,
X: The ratio of strength (g/25 mm) when peeling the pressure-sensitive adhesive sheet from the alkali-free glass after peeling the surface protective film is less than 70%.

[Wetability test]
The surface protection film obtained above was cut into a width of 25 mm and a length of 200 mm. Then, the pressure-sensitive adhesive layer surface (FIG. 12) of the surface protective film (FIG. 11) after peeling the release film, and non-alkali glass (EAGLE XG (registered trademark), manufactured by Corning) (FIG. 13) While keeping the one end face of the surface protection film and the alkali-free glass in contact with each other so that the angle formed by the longitudinal direction of the surface protection film and the surface of the alkali-free glass is 20 to 30°, Held Thereafter, the surface protective film was released, and the surface protective film and the non-alkali glass were attached only by the weight of the surface protective film (arrow in FIG. 1). At this time, the time for the surface of the pressure-sensitive adhesive layer of the surface protective film to spread over the surface of the alkali-free glass was measured visually. Then, the wettability of the surface protective film was evaluated according to the following criteria, and it was determined that the results were better than the following Δ evaluations:
(Evaluation criteria)
◎: Wet spreading time is less than 3 seconds,
◯: Wetting and spreading time is 3 seconds or more and less than 5 seconds,
△: Wetting and spreading time is 5 seconds or more and less than 10 seconds,
×: Wet spreading time is 10 seconds or more.

[Transmittance (%)]
The obtained surface protection film was cut into a width of 25 mm and a length of 50 mm, and the release film was peeled off. Then, the surface protective film was pressure-bonded to the non-alkali glass so that the surface of the pressure-sensitive adhesive layer of the surface protective film was in contact with the non-alkali glass (EAGLE XG (registered trademark), manufactured by Corning) to prepare a test sample. The transmittance (%) of this test sample was measured using a haze meter (NDH500W, manufactured by Nippon Denshoku Industries Co., Ltd.).

[Haze (%)]
The obtained surface protection film was cut into a width of 25 mm and a length of 50 mm, and the release film was peeled off. Then, the surface protective film was pressure-bonded to the non-alkali glass so that the surface of the pressure-sensitive adhesive layer of the surface protective film was in contact with the non-alkali glass (EAGLE XG (registered trademark), manufactured by Corning) to prepare a test sample. Haze (%) of this test sample was measured using a haze meter (NDH500W, manufactured by Nippon Denshoku Industries Co., Ltd.).

As shown in Tables 1 and 2 above, the surface protective films 13 to 18 have pressure-sensitive adhesive layers formed from the thermosetting pressure-sensitive adhesive compositions 13 to 18 according to Comparative Examples, which are outside the scope of the present invention. .. These thermosetting pressure-sensitive adhesive compositions have an excessive amount of the component (D) or do not contain the component (D). It was confirmed that the surface protection films 13 to 15 and 18 were inferior in punching workability and wettability and had high haze. Further, it was confirmed that the surface protection films 16 and 17 had a large glass adhesive force.

On the other hand, the surface protection films 1 to 12 have an adhesive layer formed from the thermosetting adhesive compositions 1 to 12 according to the examples within the scope of the present invention. It was confirmed that these surface protection films 1 to 12 have both high tackiness and reworkability. It was also confirmed that these surface protective films were less likely to cause the pressure-sensitive adhesive layer to fall off, had a small peeling electrification voltage, reduced substrate contamination, and had good wettability. Moreover, it was confirmed that these surface protection films had high transmittance and low HAZE, and had high transparency.

<Evaluation 2 of surface protection film>
Regarding the manufactured surface protection films 19 to 23, the glass adhesion, the glass adhesion after ultraviolet irradiation, the punching workability, the peeling electrification voltage, and the substrate contamination were evaluated by the same method and evaluation criteria as in Evaluation 1 of the surface protection film. The wettability, wettability test, transmittance and haze were evaluated. In addition to the above, the following evaluations were performed on the surface protection films 1 and 19 to 23 produced above. The evaluation results are shown in Table 3 below.

[Glass adhesion ratio]
The surface protection film obtained above was cut into a width of 25 mm and a length of 200 mm. Next, the pressure-sensitive adhesive layer surface of the surface protection film after peeling the release film and non-alkali glass (EAGLE XG (registered trademark), manufactured by Corning) were pressure-bonded by the same method as in the evaluation of the glass adhesive strength. Then, the alkali-free glass to which the surface protective film was pressure-bonded was left for 15 days (360 hours) in a test environment of 23° C.×50% RH and LED illumination (500 Lux). Then, the strength when the surface protective film was peeled off from the alkali-free glass was measured by the same method as in the evaluation of the glass adhesive strength, and this value was taken as the glass adhesive strength (g/25 mm) after the LED stability test. A value obtained by dividing the value of the glass adhesive force after the LED stability test by the value of the glass adhesive force evaluated above was defined as the glass adhesive force ratio. The glass adhesion ratio is not particularly limited, but it is considered to be particularly good when it is 0.8 or more and 1.2 or less.

[Glass adhesion ratio after UV irradiation]
The surface protection film obtained above was cut into a width of 25 mm and a length of 200 mm. Next, the pressure-sensitive adhesive layer surface of the surface protection film after peeling the release film and non-alkali glass (EAGLE XG (registered trademark), manufactured by Corning) were pressure-bonded by the same method as in the evaluation of the glass adhesive strength. Then, the alkali-free glass to which the surface protective film was pressure-bonded was left for 15 days (360 hours) in a test environment of 23° C.×50% RH and LED illumination (500 Lux). Then, the surface protective film after standing was irradiated with ultraviolet rays in the same manner as in the evaluation of the glass adhesive strength after the irradiation of ultraviolet rays described above, and the curing of the adhesive layer was promoted. Then, the glass adhesive force was measured in the same manner as the measurement of the glass adhesive force. This value was taken as the glass adhesion (g/25 mm) after UV irradiation after the LED stability test. A value obtained by dividing the value of the glass adhesive strength after UV irradiation after the LED stability test by the value of the glass adhesive strength after UV irradiation evaluated above was defined as the glass adhesive strength ratio after UV irradiation. The glass adhesion strength ratio after irradiation with ultraviolet rays is not particularly limited, but a glass adhesion strength ratio of 1.2 or less is considered to be particularly good.

As shown in the results of Table 3 above, the surface protective films 19 to 23 have pressure-sensitive adhesive layers formed from the pressure-sensitive adhesive compositions 19 to 23 according to the examples within the scope of the present invention. These adhesive compositions contain component (G). Then, in the surface protection films 19 to 23, the glass adhesion strength ratio and the glass adhesion strength ratio after irradiation with ultraviolet rays were in a better range as compared with the surface protection film 1 containing no stabilizer. From this, it was confirmed that the surface protection films 19 to 23 contain the component (G), and thus the progress of the photo-curing reaction of the adhesive layer under LED illumination is suppressed.

This result indicates that the surface protection film according to one aspect of the present invention further contains the component (G), so that light shielding is not indispensable during storage and the storability is further improved.

1 Surface protection film after peeling the peeling film,
2 adhesive layer surface,
3 Non-alkali glass.

Claims (15)

Component (A): urethane prepolymer having two or more hydroxyl groups,
Component (B): polyfunctional (meth)acrylate,
(C) component: cross-linking agent,
(D) component: crosslinked particles,
(E) component: photo radical initiator, and (F) component: antistatic agent,
Containing
Content of the said (D) component with respect to 100 mass parts of said (A) components is 0.01 mass part or more and 10 mass parts or less, The adhesive composition characterized by the above-mentioned. The pressure-sensitive adhesive composition according to claim 1, wherein the pressure-sensitive adhesive strength of the pressure-sensitive adhesive composition is reduced by light irradiation. The content of the component (B) with respect to 100 parts by mass of the component (A) is 10 parts by mass or more and 150 parts by mass or less,
The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the hydroxyl value of the component (B) is 100 mg·KOH/g or less. The component (C) contains a compound having an isocyanate group,
The equivalent ratio (NCO(total)(mol)/OH(mol)) of the total amount of isocyanate groups of the compound having an isocyanate group to the total amount of hydroxyl groups of the component (A) is 0.2 or more and 10 or less. The pressure-sensitive adhesive composition according to any one of claims 1 to 3. The component (C) contains a compound having an isocyanate group,
The compound having an isocyanate group contains a bifunctional isocyanate,
An equivalent ratio (NCO(bifunctional)(mol)/NCO(total)(mol)) of the amount of isocyanate groups of the difunctional isocyanate to the total amount of isocyanate groups of the isocyanate is more than 0 and less than 1. The pressure-sensitive adhesive composition according to any one of claims 1 to 4. The pressure-sensitive adhesive composition according to any one of claims 1 to 5, wherein the component (C) contains a trifunctional or higher functional isocyanate. The pressure-sensitive adhesive composition according to any one of claims 1 to 6, wherein the component (A) contains a urethane prepolymer having a polyether skeleton and two or more hydroxyl groups. 8. The urethane prepolymer having a polyether skeleton and two or more hydroxyl groups is a urethane prepolymer having a polyether skeleton and two or more hydroxyl groups and a (meth)acryloyloxy group. The pressure-sensitive adhesive composition according to. The pressure-sensitive adhesive composition according to any one of claims 1 to 8, wherein the average particle diameter of the component (D) is 0.5 µm or more and 30 µm or less. Content of the said (E) component with respect to 100 mass parts of said (A) components is 0.1 mass part or more and 10 mass parts or less, The said any one of Claims 1-9 characterized by the above-mentioned. Adhesive composition. The content of the component (F) with respect to 100 parts by mass of the component (A) is 0.5 parts by mass or more and 10 parts by mass or less, and the composition according to claim 1. Adhesive composition. Component (G): The pressure-sensitive adhesive composition according to any one of claims 1 to 11, which further contains a stabilizer. The pressure-sensitive adhesive composition according to any one of claims 1 to 11, characterized in that the component (G): stabilizer is not contained in an amount of more than 5 parts by mass with respect to 100 parts by mass of the component (A). A cured product of the pressure-sensitive adhesive composition according to any one of claims 1 to 13. A surface protective film, comprising: a resin film; and a pressure-sensitive adhesive layer formed on one surface of the resin film, the pressure-sensitive adhesive layer comprising the cured product according to claim 14.