CN113227300B

CN113227300B - Adhesive composition, cured product, and surface protective film

Info

Publication number: CN113227300B
Application number: CN201980086075.7A
Authority: CN
Inventors: 高桥利行; 诹访达弘
Original assignee: Samsung SDI Co Ltd
Current assignee: Samsung SDI Co Ltd
Priority date: 2018-12-28
Filing date: 2019-12-27
Publication date: 2023-09-12
Anticipated expiration: 2039-12-27
Also published as: KR102467158B1; KR20200083206A; CN113227300A; JP2020105454A; JP7241538B2

Abstract

< problem > the present invention provides a method capable of forming an adhesive layer, in which adhesion and reworkability are highly coordinated by reducing adhesion during peeling to be lower than that in an adhered state. In addition, the present invention provides a method capable of coordinating adhesion and reworkability, improving the press workability of an adhesive layer, reducing the substrate contamination thereof, reducing the peeling electrostatic voltage of the adhesive layer, and improving the wettability of the adhesive layer to a product to be bonded. < solution > the present invention relates to an adhesive composition comprising: (A) A component that is a urethane prepolymer having two or more hydroxyl groups; (B) a component which is a multifunctional (meth) acrylate; (C) a component which is a crosslinking agent; (D) a component which is a crosslinked particle; (E) a component which is a photo radical initiator; and (F) a component which is an antistatic agent, wherein the amount of the (D) component is about 0.01 to 10 parts by weight based on 100 parts by weight of the (A) component.

Description

Adhesive composition, cured product, and surface protective film

Technical Field

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

Background

For surface protection, a surface protective film having an adhesive layer is adhered to the surface of various displays (such as word processors, computers, mobile phones, etc.), various optical components including polarizers or other laminates, or various substrates (substrates, bases) (such as electronic substrates, etc.).

The adhesive layer is required to exhibit good adhesion in the bonded state. Here, the adhesiveness of the adhesive layer refers to a property that the adhesive layer exhibits sufficient adhesive strength to an adherend without failure (such as delamination, slight warpage, or the like). Since the surface protective film is peeled from the adherend during the manufacturing process or in actual use, when the adhesive layer has excessive adhesive strength, the adherend may be broken or cracked or may have adhesive residues on its surface. Therefore, the adhesive layer is required to have good reworkability (reworkability) at the time of peeling. Reworkability refers to the property that allows the adhesive layer to be easily peeled from the adherend without damaging the adherend or generating adhesive residue on the adherend.

As an adhesive composition capable of ensuring compatibility between adhesion and reworkability, a urethane-based adhesive composition has been proposed.

Patent document 1 (japanese unexamined patent publication No. 2007-169377) and patent document 2 (japanese unexamined patent publication No. 2005-154492) disclose an adhesive film comprising an adhesive layer formed of an adhesive composition comprising a hydroxyl group-containing polyurethane, an ionic compound, and a trifunctional isocyanate compound to achieve compatibility between adhesive strength and reworkability of the adhesive film.

Patent document 3 (japanese unexamined patent publication No. 2007-238766) discloses an adhesive layer formed of an adhesive composition containing a urethane urea resin (urethane urea resin) containing a terminal hydroxyl group, an ionic compound and a polyfunctional isocyanate compound to improve reworkability.

Disclosure of Invention

Technical problem

The adhesive layer formed of each of the adhesive compositions disclosed in patent documents 1 to 3 has compatibility between adhesiveness and reworkability by adjusting adhesive strength. However, in these methods, since both the adhesiveness and reworkability depend on the adhesive strength of the adhesive layer, there is a trade-off (trade-off) between the adhesiveness and reworkability. In other words, sufficient reworkability results in insufficient adhesion and vice versa. Furthermore, urethane-based adhesive compositions may cause insufficient punching workability (punching processability) or insufficient prevention of contamination of a substrate (matrix), or may cause an increase in stripping electrostatic voltage. Furthermore, depending on the kind of urethane compound in the urethane-based adhesive composition, the adhesive layer may exhibit insufficient wettability to an adherend. In this case, when the adhesive layer adheres to an adherend, the adhesive layer may suffer from adhesion failure due to invasion of air.

An object of the present invention is to provide a method capable of forming an adhesive layer, which ensures high compatibility between adhesion and reworkability by reducing adhesive strength when peeled off in a bonded state. Another object of the present invention is to provide a method for improving press workability and substrate contamination while reducing peeling electrostatic voltage and achieving high transparency and high wettability of an adhesive layer to an adherend in addition to compatibility between adhesion and reworkability.

Technical proposal

The above and other objects of the present invention can be achieved by:

an adhesive composition comprising: a urethane prepolymer having at least two hydroxyl groups ((a) component), a multifunctional (meth) acrylate ((B) component, a crosslinking agent ((C) component), crosslinked particles ((D) component), a photo radical initiator ((E) component), and an antistatic agent ((F) component), wherein the (D) component is present in an amount of about 0.01 parts by weight to about 10 parts by weight relative to 100 parts by weight of the (a) component.

Advantageous effects

The present invention provides a method capable of forming an adhesive layer, which ensures high compatibility between adhesiveness and reworkability by reducing adhesive strength when peeled off in a bonded state. Further, the present invention provides a method of improving press workability and substrate contamination while reducing peeling electrostatic voltage and achieving high transparency and high wettability of an adhesive layer to an adherend in addition to compatibility between adhesion and reworkability.

Drawings

Fig. 1 is a diagram showing a method for measuring wettability of an adhesive layer to an adherend.

Detailed Description

Best mode

Hereinafter, embodiments of the present invention will be described in detail. In addition, unless otherwise specifically indicated, the operations and properties were measured at room temperature (20 ℃ to 25 ℃) per 40% RH (relative humidity) to 50% RH.

In this context, "(meth) acrylate" is the generic term for acrylates and methacrylates. A (methyl) -containing compound such as (meth) acrylic acid is also in its terminology a generic term for a compound containing "(methyl)" and a compound not containing "(methyl)".

Herein, "(co) polymers" are the generic term for homopolymers and copolymers.

< adhesive composition >

One embodiment of the present invention relates to:

The inventors of the present invention evaluated the mechanism by which the adhesive composition can solve the following problems.

The urethane-based adhesive composition generally forms an adhesive layer through polymerization and crosslinking reactions of a urethane compound and a crosslinking agent (e.g., an isocyanate compound) contained therein. With typical urethane-based adhesive compositions disclosed in patent documents 1 to 3, attempts are made to control adhesion and reworkability by adjusting the kind of urethane compound or crosslinking agent, the amount thereof, the reaction conditions, and the like. However, since both the adhesiveness and reworkability depend on the adhesive strength of the adhesive layer they form, it is difficult to ensure a high degree of compatibility between them due to a trade-off relationship between the adhesiveness and reworkability.

An adhesive composition according to an embodiment of the present invention includes: a urethane prepolymer having at least two hydroxyl groups ((a) component) and a crosslinking agent ((C) component). In addition, the adhesive composition includes a multifunctional (meth) acrylate ((B) component) and a photo radical initiator ((E) component). Therefore, reworking with light irradiation of the adhesive composition results in photopolymerization and crosslinking reaction of the (B) component or the multifunctional (meth) acrylate or the (meth) acryl (co) polymer derived therefrom, and significantly reduces the adhesive strength of the adhesive composition. As a result, the adhesive layer composed of the cured product of the adhesive composition according to the embodiment may exhibit good adhesive strength and good reworkability before irradiation with light. In this way, the adhesive composition can overcome the technical problems of typical urethane-based adhesive compositions, which have a trade-off relationship between adhesion and reworkability. In other words, the adhesive composition according to the embodiment can individually control the adhesive strength in the bonded state and the adhesive strength at the time of reworking based on an idea completely different from that of a typical urethane-based adhesive composition.

In addition, the adhesive composition according to the embodiment of the present invention contains crosslinked particles ((D) component). Here, the (D) component forms unevenness on the surface of the adhesive layer. When unevenness is formed on the surface thereof, the adhesive strength of the adhesive layer is lowered. As a result, the adhesive layer has a suitable adhesive strength before irradiation with light, and exhibits improved adhesion. Further, at the time of reworking, the adhesive strength of the adhesive layer is lowered, thereby improving reworkability of the adhesive layer or the adhesive film including the adhesive layer.

In the adhesive composition according to the embodiment, the (D) component is present in a predetermined amount. In other words, the content of the (D) component is required to be within a sufficient range to provide the above-mentioned effects without exceeding the range excessively. Within this range of the (D) component, the adhesive composition can achieve compatibility between adhesion and reworkability while suppressing deterioration of transparency and wettability of the adhesive layer to an adherend. Further, by preventing addition of an excessive amount of the (D) component, falling off (dropping out) of the (D) component can be suppressed while ensuring good press workability. In addition, bleeding of the (F) component can be prevented and a low peeling electrostatic voltage can be achieved while maintaining good substrate contamination resistance. In another aspect, it should be noted that the above mechanism is based on estimation and does not affect the scope of the present invention.

Preferably, the adhesive composition according to the embodiment forms the adhesive layer by heat curing. In other words, the adhesive composition according to the present invention is preferably a thermosetting adhesive composition. Further, the adhesive layer formed of the adhesive composition according to the embodiment is composed of a cured product, preferably a heat cured product, of the adhesive composition. Herein, the heat-cured product refers to a cured product formed by a thermal crosslinking reaction. The heat-cured product does not require heating, and includes a cured product obtained by curing at room temperature (20 ℃ to 25 ℃).

Furthermore, one embodiment of the present invention relates to an adhesive composition that allows the adhesive strength to be reduced by irradiation with light. Here, "decrease in adhesive strength of the adhesive composition" means decrease in adhesive strength of the adhesive composition itself and its heat-cured product by irradiation with light. As a result, the adhesive composition exhibits good adhesion in a bonded state and also exhibits remarkable reworkability by irradiation with light at the time of reworking.

Here, it is desirable that the ratio of the adhesive strength of the heat-cured product of the adhesive composition after irradiation with light to the adhesive strength before irradiation with light or the ratio of the adhesive strength before and after irradiation with light is in the same range as the adhesive layer or adhesive film described below.

Hereinafter, each component constituting the adhesive composition according to the embodiment of the present invention will be described in detail.

[ (A) component: urethane prepolymer containing at least two hydroxyl groups

The adhesive composition according to an embodiment of the present invention includes a urethane prepolymer ((a) component) containing at least two hydroxyl groups. (A) The component is used to impart adhesiveness to an adhesive layer composed of a cured product of the adhesive composition. (A) The components may contribute to the formation of the adhesive layer by polymerization (preferably thermal polymerization) and cross-linking reactions.

More specifically, the hydroxyl groups of the (a) component may be located at both ends of the (a) component, but are not limited thereto. (A) The component may be selected from any urethane prepolymer known in the art, but is not limited thereto.

As is well known in the art, urethane prepolymers are obtained by the reaction between a component containing at least two hydroxyl groups (e.g., a polyol component) and a polyfunctional isocyanate component. Here, the (a) component may be a compound obtained by, for example, reacting a polyol ((a 1) component) and a polyfunctional isocyanate ((a 2) component).

(a1) The component may be selected from any polyol known in the art without limitation. For example, as the (a 1) component, polyether polyol known in the art, polyester polyol known in the art, polycarbonate polyol known in the art, polybutadiene polyol known in the art, polyisoprene polyol known in the art, and the like can be used. These may be used alone or as a mixture thereof. The mixture may be a mixture of the same kind of compounds or may be a mixture of different kinds of compounds. In addition, these polyols may contain 2 to 4 hydroxyl groups per molecule, but are not limited thereto.

The polyether polyol may be a polyether polyol having a repeating structure of an alkylene oxide chain (alkylene oxide chain ) (e.g., methylene oxide chain (methylene oxide chain ), ethylene oxide chain (ethylene oxide chain ), propylene oxide chain (propylene oxide chain ), butylene oxide chain (butylene oxide chain ), or the like). The alkylene oxide chains may be used alone or as a mixture thereof. Preferably, the polyether polyol has hydroxyl groups bonded to primary carbon atoms for good reactivity with isocyanate groups. Examples of the polyether polyol may include polyethylene glycol, polypropylene glycol, terminal polyethylene glycol-terminated polypropylene glycol, and polytetramethylene glycol, but are not limited thereto.

The polyester polyol may be a polyester polyol prepared from a well-known acid component and a well-known alcohol component. Examples of the acid component may include adipic acid, azelaic acid, sebacic acid, phthalic anhydride, isophthalic acid, terephthalic acid, trimellitic acid, and the like. Further, examples of the alcohol component may include ethylene glycol, diethylene glycol, 1, 4-butanediol, 1, 6-hexanediol, 2-methyl-1, 3-propanediol, 3-methyl-1, 5-pentanediol, neopentyl glycol, butylethylpropanediol, glycerol, trimethylolpropane, pentaerythritol, and the like. Each of the acid component and the alcohol component may be used alone or as a mixture thereof. In addition, the polyester polyol can be obtained by ring-opening polymerization of lactones such as polycaprolactone, poly (beta-methyl-gamma-valerolactone) and polypentanolide.

The polycarbonate polyol may be a polycarbonate polyol obtained by reacting a well-known carbonate or phosgene with a compound containing two or more hydroxyl groups. Examples of the carbonate may include methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclic carbonate, diphenyl carbonate, and the like. Further, examples of the compound containing two or more hydroxyl groups may include aliphatic polyols, alicyclic polyols, aromatic polyols, and the like. Examples of the aliphatic polyol may 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-propanediol, 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 may include 1, 2-cyclobutanediol, 1, 3-cyclopentanediol, 1, 4-cyclohexanedimethanol, cycloheptanediol, cyclooctanediol, hydroxypropyl cyclohexanol, and the like. Examples of the aromatic polyol may include bisphenol a, bisphenol F, 4' -biphenol, and the like. Each of the carbonate and the compound having two or more hydroxyl groups may be used alone or as a mixture thereof.

(a1) The component preferably has a number average molecular weight of about 700 to about 5,000, but is not limited thereto. More preferably, component (a 1) has a number average molecular weight of from about 1,000 to about 4,000. Within this range, the (a 1) component allows easy control of the reaction in its preparation. The number average molecular weight of component (a 1) can be calculated by Gel Permeation Chromatography (GPC) from polystyrene standards.

In addition, some of the (a 1) components may be replaced by low molecular weight polyols or polyhydroxy amines (polyhydroxy amines). Examples of the low molecular weight polyol may include ethylene glycol, 1, 4-butanediol, 2-methyl-1, 3-propanediol, 3-methyl-1, 5-pentanediol, neopentyl glycol, butylethylpropanediol, glycerol trimethylolpropane, pentaerythritol, dimer diol, castor oil type polyol, and the like. Examples of the polyhydric amine may include ethylenediamine, N-aminoethylethanolamine, isophoronediamine, xylylenediamine (xylenediamine), and the like.

(a2) The component may be selected from any polyfunctional isocyanate known in the art without limitation. For example, the (a 2) component may include an aromatic diisocyanate such as xylylene diisocyanate, phenylene diisocyanate, toluene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, and the like. In addition, the (a 2) component may include aliphatic or alicyclic diisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, diisocyanate methylcyclohexane, tetramethyl xylylene diisocyanate, and the like. In addition, component (a 2) may be selected from adducts, biurets (burets) and isocyanurates of these diisocyanates. These polyfunctional isocyanate compounds may be used alone or as a mixture thereof.

Among these polyfunctional isocyanate compounds, aliphatic diisocyanates or alicyclic diisocyanates are preferably used in terms of suppression of discoloration. More preferably, aliphatic diisocyanates are used in terms of their easy control of the reaction in preparation.

(A) The component preferably comprises a urethane prepolymer having a polyether backbone and at least two hydroxyl groups. The polyether backbone is used to impart high wettability to various objects such as glass by its molecular structure. The adhesive composition can also improve the wettability of the adhesive layer to an adherend using the urethane prepolymer as compared to adhesive compositions containing other urethane prepolymers.

More specifically, the urethane prepolymer having a polyether skeleton and at least two hydroxyl groups is a urethane oligomer or polyurethane having a polyether structure as a part of the main chain and having at least two hydroxyl groups per molecule. Polyether structure means a repeating structure of alkylene oxide such as a methylene oxide chain, an ethylene oxide chain, a propylene oxide chain, a butylene oxide chain, or the like.

More preferably, the urethane prepolymer having a polyether skeleton and at least two hydroxyl groups is a urethane prepolymer having a polyether skeleton, at least two hydroxyl groups and (meth) acryloyloxy groups. With such urethane prepolymers, the adhesive composition can also improve reworkability of an adhesive layer formed therefrom or an adhesive film comprising the adhesive layer. The inventors estimated (evaluated, judged) that this effect was achieved by photopolymerization and crosslinking reaction of the (a) component with the (E) component described below or by photopolymerization and crosslinking reaction of the (a) component with the (B) component or (co) polymer thereof. Further, (meth) acryloyloxy groups are preferably present as side chains in the molecules of the urethane prepolymer, but are not limited thereto. The adhesive composition may also improve reworkability of an adhesive layer formed therefrom or an adhesive film comprising the adhesive layer using the urethane prepolymer.

The urethane prepolymer having a polyether backbone and at least two hydroxyl groups may be selected from any urethane prepolymer compound known in the art. For example, a compound obtained by the reaction of a polyether polyol corresponding to the (a 1) component and the (a 2) component can be used.

The urethane prepolymer having a polyether backbone, at least two hydroxyl groups and (meth) acryloxy groups may be selected from any urethane prepolymer compound known in the art. For example, a compound obtained by reacting the (a 1) component and the (a 2) component with a (meth) acrylate compound containing a hydroxyl group or an isocyanate group (a (meth) acryloyloxy group-containing compound) ((a 3) component) may be used. Here, the (a 3) component is used for the purpose of supplying the (meth) acryloyloxy group to the (A) component.

(a3) The component may be selected from any well known (meth) acrylate compound containing hydroxyl or isocyanate groups without limitation. In particular, in terms of raw material availability, curability, and adhesiveness, a hydroxyl group-containing (meth) acrylate compound is preferably used.

The hydroxyl group-containing (meth) acrylate compound may include, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, hydroxyethyl acrylamide, trimethylol propane di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, polyethylene glycol monoacrylate, polypropylene glycol monoacrylate, and the like.

The isocyanate group-containing (meth) acrylate compound may include, for example, 2- (meth) acryloyloxyethyl isocyanate, 2- (2- (meth) acryloyloxyethyl oxy) ethyl isocyanate, 1-bis ((meth) acryloyloxymethyl) ethyl isocyanate, and the like.

Alternatively, the urethane prepolymer having a polyether backbone, at least two hydroxyl groups and (meth) acryloyloxy groups may be selected from other compounds. For example, the urethane prepolymer having a polyether skeleton, at least two hydroxyl groups and a (meth) acryloyloxy group may be a compound obtained by reacting a compound containing at least two isocyanate groups with a reaction product of the (a 1) component, a trifunctional or higher-functional isocyanate and a (meth) acrylate compound containing a hydroxyl group. Here, the trifunctional or higher-functional isocyanate may be, for example, a compound represented by the (C) component described below, but is not limited thereto. In addition, the hydroxyl group-containing (meth) acrylate compound may be, for example, the same as the (a 3) component, but is not limited thereto. Alternatively, the urethane prepolymer having a polyether skeleton, at least two hydroxyl groups and a (meth) acryloyloxy group may be a compound obtained by reacting a compound containing at least two hydroxyl groups with a reaction product of the (a 2) component, a trifunctional or higher-functional polyol and a (meth) acrylate compound containing an isocyanate group. Here, the trifunctional or higher-functional polyol may be, for example, the same as the compound represented by the (a 1) component, but is not limited thereto. Alternatively, the isocyanate group-containing (meth) acrylate compound may be, for example, the same as the (a 3) component, but is not limited thereto.

(A) The component may have a number average molecular weight of about 1,000 or more, but is not limited thereto. More preferably, component (a) has a number average molecular weight of from about 20,000 to about 500,000, still more preferably from about 50,000 to about 200,000. Within this range, the adhesive composition has a viscosity within a suitable range, and improvement in workability can be ensured.

The number average molecular weight of the component (A) can be calculated by, for example, the following method. A sample was prepared by placing 10mg of the (A) component and 10mg of THF in a sample bottle and allowing it to stand for 1 day to dissolve, followed by filtration through a cartridge PTFE filter (0.5 μm). In the measurement of the number average molecular weight, RI detector RI8020 (Toso co., ltd.) and TSKgelGMR-HHRL (Toso co., ltd.) x 2 series were used as columns for measurement and HLC-8020GPC (Toso co., ltd.) to measure the number average molecular weight. Measurements were made with THF solvent at column temperature of 40 ℃ and flow rate of 1.0ml/min, and analysis of the number average molecular weight was performed based on a three-level trend standard line using standard polystyrene (Toso co., ltd.).

(A) The components may have a hydroxyl number of from about 1 mgKOH/g to about 230 mgKOH/g. More preferably, the (A) component has a hydroxyl number of from about 3 mg.KOH/g to about 150 mg.KOH/g, still more preferably from about 4 mg.KOH/g to about 100 mg.KOH/g. Within this range, the adhesive composition can ensure more suitable adhesive strength of the adhesive layer formed therefrom or the adhesive film containing the adhesive layer, and an improvement in suppressing detachment of the adhesive layer can be achieved. The inventors estimated that these effects are achieved by suitable photopolymerization and crosslinking reactions of the (a) component and the (C) component described below. On the other hand, the hydroxyl value can be calculated in accordance with JIS K0070:1992. Here, the hydroxyl value of the component (A) may be used as an index indicating the content of hydroxyl groups.

(A) The component may have a double bond equivalent weight (polymer weight (g) per 1 mole of double bonds) of about 30,000g/mol or less. More preferably, the (A) component has a double bond equivalent weight of about 20,000g/mol or less, still more preferably about 10,000g/mol or less. In addition, the (A) component may have a double bond equivalent weight of about 1,000g/mol or more. Within this range, the adhesive composition can ensure more suitable adhesive strength of the adhesive layer formed therefrom or the adhesive film containing the adhesive layer, and an improvement in suppressing detachment of the adhesive layer can be achieved. For example, the (A) component may have a double bond equivalent of about 1,000g/mol, 2,000g/mol, 3,000g/mol, 4,000g/mol, 5,000g/mol, 6,000g/mol, 7,000g/mol, 8,000g/mol, 9,000g/mol, 10000g/mol, 11000g/mol, 12000g/mol, 13000g/mol, 14000g/mol, 15000g/mol, 16000g/mol, 17000g/mol, 18000g/mol, 19000g/mol, 20000g/mol, 21000g/mol, 22000g/mol, 23000g/mol, 24000g/mol, 25000g/mol, 26000g/mol, 27000g/mol, 28000g/mol, 29000g/mol, or 30000 g/mol. The inventors estimated that these effects are achieved by suitable photopolymerization and crosslinking reactions of the (a) component and the (B) component or the (co) polymer thereof with the (E) component described below. Here, for the (a) component having a (meth) acryloyloxy group, the double bond equivalent of the (a) component may be used as an index indicating the content of the (meth) acryloyloxy group. (A) The components may be prepared by any well known method or may be obtained from any commercially available product.

(A) The components may be prepared by any well known method for preparing urethane compounds without limitation. In particular, component (a) is preferably prepared by urethanization (urethanization) reactions well known in the art under conditions of excess hydroxyl groups. For the component (A) and a method for producing the same, see Japanese unexamined patent publication No. 2005-169377, japanese unexamined patent publication No. 2007-168377, etc. In addition, in the preparation of the (a) component, a typical polymerization inhibitor, a typical urethanization catalyst, or the like may be used as needed. Examples of commercially available products may includeSH101(Dongyang Ink Co.Ltd.)、ART />UN5500, UN5500P (chemical industry on root corporation (Negami Chemical Industrial co., ltd.)) and the like. For the (a) component, the urethane prepolymer may be used alone or as a mixture thereof.

[ (B) component: multifunctional (meth) acrylate ]

The adhesive composition according to an embodiment of the present invention includes a multifunctional (meth) acrylate ((B) component). (B) The component is used to allow photopolymerization and crosslinking reaction to occur upon irradiation with light, and to improve reworkability by reducing adhesive strength after irradiation with light. The adhesive composition containing no component (B) is not allowed to decrease adhesive strength upon irradiation with light, and has insufficient reworkability.

In one embodiment, the (B) component may include a non-urethane based (non-urethane) multifunctional (meth) acrylate that does not contain urethane groups.

(B) The component may be selected from any of the well known multifunctional (meth) acrylates having at least two (meth) acryloyloxy groups therein. In particular, for example, the (B) component may comprise difunctional to decafunctional (meth) acrylates. Further, the (B) component may be an undec functional or higher functional (meth) acrylate such as a poly pentaerythritol poly (meth) acrylate or the like.

Examples of difunctional (meth) acrylates may include dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, 1, 4-butanediol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, propylene oxide modified neopentyl glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentyl 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, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate, pentaerythritol di (meth) acrylate, dipentaerythritol di (meth) acrylate, tripentaerythritol di (meth) acrylate, tetrapentaerythritol di (meth) acrylate, and the like.

Examples of the trifunctional (meth) acrylate may include pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, tripentaerythritol tri (meth) acrylate, tetrapentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol 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, glycerol propoxytri (meth) acrylate, tris (acryloxyethyl) isocyanurate, and the like.

Examples of the tetrafunctional (meth) acrylate may include pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, tripentaerythritol tetra (meth) acrylate, tetrapentaerythritol tetra (meth) acrylate, pentaerythritol ethoxy tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, and the like.

Examples of pentafunctional (meth) acrylates may include dipentaerythritol penta (meth) acrylate, tripentaerythritol penta (meth) acrylate, tetrapentaerythritol penta (meth) acrylate, propionic acid modified dipentaerythritol penta (meth) acrylate, dipentaerythritol monohydroxy penta (meth) acrylate, and the like.

Examples of the hexafunctional (meth) acrylate may include dipentaerythritol hexa (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tetrapentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, and the like.

Examples of the heptafunctional (meth) acrylate may include tripentaerythritol hepta (meth) acrylate, tetrapentaerythritol hepta (meth) acrylate, and the like.

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

Examples of the nine-functional (meth) acrylate may include tetrapentaerythritol nine (meth) acrylate and the like.

Examples of the decafunctional (meth) acrylate may include tetrapentaerythritol deca (meth) acrylate and the like.

Of these compounds, the (B) component preferably includes a trifunctional (meth) acrylate, more preferably a trimethylolpropane tri (meth) acrylate, still more preferably a trimethylolpropane triacrylate.

The compound having at least two (meth) acryloyloxy groups therein may include urethane (meth) acrylate, polyester (meth) acrylate, and the like.

The urethane (meth) acrylate is not limited to a specific compound. For example, a monomer or oligomer obtained by reacting a diisocyanate, a polyol, and a (meth) acrylate compound containing a hydroxyl group can be used. Examples of urethane (meth) acrylates are disclosed in Japanese unexamined patent publication No. 2002-265650, japanese unexamined patent publication No. 2002-355936, japanese unexamined patent publication No. 2002-067238, and the like.

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

Examples of the polyol may include poly (propylene oxide) glycol (poly (propylene oxide) glycol), poly (tetramethylene oxide) glycol, ethoxylated bisphenol a, ethoxylated bisphenol S, spiro glycol (spiro glycol), caprolactone-modified glycol, carbonate glycol (carbonate glycol), and the like.

Examples of the hydroxyl group-containing (meth) acrylate compound may include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycidyl di (meth) acrylate, pentaerythritol triacrylate, and the like.

The urethane (meth) acrylate is not limited to a specific compound. For example, urethane (meth) acrylates may include adducts of TDI with hydroxyethyl acrylate, adducts of IPDI with hydroxyethyl acrylate, adducts of HDI with pentaerythritol triacrylate (PETA), compounds obtained by reacting dodecyloxy hydroxypropyl acrylate with isocyanate remaining after the preparation of adducts of TDI with PETA, adducts of 6,6 nylon with TDI, adducts of pentaerythritol with TDI and hydroxyethyl acrylate, and the like.

Polyester (meth) acrylates are obtained by condensation of (meth) acrylic acid and hydroxyl groups remaining in the polyester backbone prepared from polyols and diacids. The polyester acrylate is not limited to a specific compound. Examples of polyester acrylates may include phthalic anhydride/propionic acid oxide/acrylic acid reaction products, adipic acid/1, 6-hexanediol/acrylic acid reaction products, trimellitic acid/diethylene glycol/acrylic acid reaction products, and the like.

In addition, component (B) preferably also contains hydroxyl groups. The adhesive composition can also suppress detachment of the adhesive layer using hydroxyl groups. The inventors estimated that this effect is achieved by polymerization and crosslinking reaction of the (A) component and the (C) component, and polymerization and crosslinking reaction of the (B) component or its (co) polymer with the (C) component.

Preferably, the (B) component has a hydroxyl value of about 100 mgKOH/g or less, but is not limited thereto. More preferably, the (B) component has a hydroxyl number of about 50 mgKOH/g or less, most preferably about 30 mgKOH/g or less (lower limit: about 0 mgKOH/g). For example, the (B) component has a hydroxyl number of about 0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100 mgKOH/g. Within this range, the adhesive composition can ensure more suitable adhesive strength of the adhesive layer formed therefrom or the adhesive film containing the adhesive layer, and an improvement in suppressing detachment of the adhesive layer can be achieved. The inventors estimated that these effects are achieved by suitable polymerization and crosslinking reactions of the (B) component or its (co) polymer with the (C) component and more suitable polymerization and crosslinking reactions of the (a) component with the (C) component. On the other hand, the hydroxyl value can be calculated according to JIS K0070:1992.

(B) The components may be prepared by any well known method or may be obtained from commercially available products. Examples of commercially available products may include A-TMPT, A-TMM-3L, A-TMM-3LM-N, ATM-35E, A-TMMT, A-9550, A-DPH (all from Jincun chemical industry Co., ltd. (Shin-Nakamura Chemical Industry Co., ltd.))),M-305, M-402, M-405 (all from Dong-A Synthesis Co., ltd.),>#295, TMPTA, #802, triPEA (all from osaka organic chemical industry limited (Osaka Organic Chemical Industry co., ltd.).

The multifunctional (meth) acrylates may be used alone or as a mixture thereof.

Although the amount of the (B) component (total amount of two or more (B) components) in the adhesive composition is not particularly limited, the (B) component is preferably present in an amount of 1 to 500 parts by weight relative to 100 parts by weight of the (a) component. More preferably, the (B) component is present in an amount of 5 to 250 parts by weight relative to 100 parts by weight of the (a) component. Still more preferably, the (B) component is present in an amount of 10 to 150 parts by weight relative to 100 parts by weight of the (a) component. Within this range, the adhesive composition can ensure proper adhesive strength of an adhesive layer formed therefrom or an adhesive film containing the adhesive layer. The inventors estimated that this effect is achieved due to the appropriate content ratio of the (a) component and the (B) component therein. Further, within this range, the adhesive composition can ensure further improvement in reworkability of the adhesive layer or the adhesive film including the adhesive layer. The inventors estimated that this effect is obtained by improving photopolymerization and crosslinking reaction of the (B) component by irradiation with light. In addition, within this range of the (B) component further containing a hydroxyl group, the adhesive composition can effectively suppress detachment of the adhesive layer. The inventors estimated that this effect is achieved by the thermal polymerization and crosslinking reaction of the (a) component, the (B) component or the (co) polymer thereof with the (C) component at the time of the thermal polymerization and crosslinking reaction of the (a) component with the (C) component. For example, the (B) component may be present in an amount of about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, 410, 420, 430, 440, 450, 460, 470, 480, 490, or 500 parts by weight relative to 100 parts by weight of the (a) component. Thus, for example, the (B) component may be present in an amount of about 10 parts by weight to about 150 parts by weight relative to 100 parts by weight of the (a) component, and the (B) component may have a hydroxyl value of about 100 mg-KOH/g or less.

[ (C) component: crosslinking agent ]

The adhesive composition according to an embodiment of the present invention includes a crosslinking agent ((C) component). (C) The component(s) are used to promote polymerization (preferably thermal polymerization) and crosslinking with the (a) component. Thus, the (C) component can be used to ensure compatibility between adhesion and reworkability by ensuring proper adhesion strength of the adhesive composition before and after irradiation with light. The adhesive composition without the (C) component may exhibit excessive adhesive strength and insufficient reworkability. In one embodiment, the (C) component may be a thermosetting cross-linking agent. In another embodiment, the (C) component may be a crosslinker that is free of (meth) acryl groups (or (meth) acrylate groups).

(C) The component (c) may be selected from any well-known crosslinking agent capable of promoting polymerization and crosslinking reaction with the component (a) without limitation. For example, the (C) component may comprise an isocyanate crosslinker, a carbodiimide crosslinker, an oxazoline crosslinker, an epoxy crosslinker, an aziridine crosslinker, a peroxide, and the like. Peroxide here means a compound having a peroxide structure (-O-). These compounds may be used alone or as a mixture thereof. The mixture may be a mixture of the same kind of compounds or may be a mixture of different kinds of compounds.

The isocyanate crosslinking agent may include any of the well-known isocyanate compounds having isocyanate groups (isocyanate compounds) well known in the art without limitation. The compound having an isocyanate group may include monofunctional isocyanates and polyfunctional isocyanates. In particular, polyfunctional isocyanates are preferably used. Examples of the polyfunctional isocyanate may include difunctional isocyanates (compounds having two isocyanate groups) and trifunctional or higher functional isocyanates (compounds having at least three isocyanate groups).

Examples of the difunctional isocyanate may include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, carbodiimide-modified diisocyanates of these diisocyanates, or high molecular weight compounds containing one of these diisocyanates at the end of the main chain or side chain or as a side chain.

Examples of the aliphatic diisocyanate may include 1, 5-pentamethylene diisocyanate, 1, 6-Hexamethylene Diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornene diisocyanate methyl ester (NBDI), and the like.

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

Examples of the aromatic diisocyanate may include dimer acid diisocyanate, 2, 4-toluene diisocyanate (2, 4-TDI), 2, 6-toluene diisocyanate (2, 6-TDI), 4 '-diphenylmethane diisocyanate (4, 4' -MDI), 2,4 '-diphenylmethane diisocyanate (2, 4' -MDI), 1, 4-phenylene diisocyanate, xylylene Diisocyanate (XDI), tetramethyl xylylene diisocyanate (TMXDI), toluidine diisocyanate (TODI), 1, 5-Naphthalene Diisocyanate (NDI), and the like.

Examples of the trifunctional or higher-functional isocyanate may include isocyanurate modified by isocyanurate after polycondensation of difunctional isocyanate, adduct modified by adduct of difunctional isocyanate after polycondensation of difunctional isocyanate, biuret of difunctional isocyanate by biuret reaction with a triol such as glycerol or trimethylolpropane, and high molecular weight compound having the aforementioned difunctional isocyanate, adduct, biuret or isocyanurate thereof at the end of the main chain or side chain or as a side chain itself.

The carbodiimide crosslinking agent may be selected from any of the well known carbodiimide compounds without limitation. Examples of the carbodiimide compound may include, but are not limited to, high molecular weight polycarbodiimides obtained by decarboxylation condensation of diisocyanates in the presence of a carbodiimidization catalyst. Examples of the diisocyanate used for decarboxylation condensation may include 4,4' -diphenylmethane diisocyanate, 3' -dimethoxy-4, 4' -diphenylmethane diisocyanate, 3' -dimethyl-4, 4' -diphenylmethane diisocyanate, 4' -diphenyl ether diisocyanate, 3' -dimethyl-4, 4' -diphenyl ether diisocyanate, 2, 4-toluene diisocyanate, 2, 6-toluene diisocyanate, 1-methoxyphenyl-2, 4-diisocyanate, isophorone diisocyanate, 4' -dicyclohexylmethane diisocyanate, tetramethylxylylene diisocyanate, and the like. Examples of the carbodiimidization catalyst used in the decarboxylation condensation may include phosphane oxides such as 1-phenyl-2-phosphane-1-oxide, 3-methyl-2-phosphane-1-oxide, 1-ethyl-2-phosphane-1-oxide, 3-phosphane isomers thereof, and the like.

The oxazoline crosslinking agent may include any well known oxazoline compound without limitation. The oxazoline compound may include an oxazoline group-containing polymer. Specifically, the oxazoline compound may include an oxazoline group-containing acrylic polymer, an oxazoline group-containing acryl/styrene polymer, and the like. Here, the oxazoline group-containing acrylic polymer may include, 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. Further, the oxazoline group-containing acryl/styrene polymer may include, for example, an oxazoline group-containing acryl/styrene polymer including a main chain composed of an acrylic or styrene skeleton and having an oxazoline group in a side chain. Examples of oxazoline groups may include 2-oxazoline groups, 3-oxazoline groups, and 4-oxazoline groups.

The epoxy crosslinking agent may include any well known epoxy compound without limitation. For example, the epoxy crosslinker may be a liquid epoxy crosslinker. Liquid epoxy compounds are preferred in terms of ease of mixing operations in the preparation of the adhesive composition.

The aziridine crosslinking agent may include any of the well known aziridine compounds without limitation. Examples of the aziridine compound may include polyfunctional aziridine compounds having a plurality of aziridine rings. Examples of the polyfunctional aziridine compound may include compounds disclosed in U.S. Pat. No. 3,225,013, U.S. Pat. No. 4,490,505, U.S. Pat. No. 5,534,391 and Japanese unexamined patent publication No. 2003-104970. As the aziridine compound, a trifunctional aziridine compound (a compound having three aziridine rings) is preferable. Examples of the trifunctional aziridine compound may include trimethylol propane tris [ 3-aziridinyl propionate ], trimethylol propane tris [3- (2-methyl-aziridinyl) -propionate ], trimethylol propane tris [ 2-aziridinyl butyrate ], pentaerythritol tris-3- (1-aziridinyl propionate), pentaerythritol tetra-3- (1-aziridinyl propionate), and the like.

The peroxide may include any well known peroxide compound without limitation. Examples of peroxides may include diisopropyl peroxydicarbonate, bis (2-ethylhexyl) peroxydicarbonate, bis (4-tert-butylcyclohexyl) peroxydicarbonate (also known as bis (4-tert-butylcyclohexyl) peroxy-2-carbonate), bis-sec-butylperoxydicarbonate, tert-butylperoxyneodecanoate, tert-hexylperoxypivalate, tert-butylperoxypivalate, dilauroyl peroxide, bis-n-octanol peroxide, 1, 3-tetramethylbutylperoxy-2-ethylhexanoate, bis (4-methylbenzoyl) peroxide, dibenzoyl peroxide, tert-butylperoxybutyrate, and the like.

Of these compounds, the crosslinking agent is preferably an isocyanate crosslinking agent or a peroxide, more preferably an isocyanate crosslinking agent. Furthermore, the isocyanate crosslinking agent may be used together with the peroxide, instead of being used alone.

Examples of the isocyanate crosslinking agent may include: hexamethylene Diisocyanate (HDI) or Pentamethylene Diisocyanate (PDI); adducts, biurets or isocyanurates thereof; and a high molecular weight compound having one of the above diisocyanates, adducts, biurets, and isocyanurates at the terminal of the main chain or side chain thereof or as a side chain itself. More preferably, the isocyanate crosslinker is an adduct of Hexamethylene Diisocyanate (HDI) or Pentamethylene Diisocyanate (PDI). Alternatively, the isocyanate crosslinking agent is a high molecular weight compound obtained by condensing Hexamethylene Diisocyanate (HDI) or Pentamethylene Diisocyanate (PDI) with a diol. Here, hexamethylene Diisocyanate (HDI) may be 1, 6-hexamethylene diisocyanate. In addition, pentamethylene Diisocyanate (PDI) may be 1, 5-pentamethylene diisocyanate. These isocyanate crosslinkers allow for more efficient polymerization and crosslinking reactions with the (a) component.

The peroxide preferably comprises bis (4-t-butylcyclohexyl) peroxydicarbonate. Such peroxide compounds allow for more efficient polymerization and crosslinking reactions with the (a) component.

(C) The components may be prepared by any well known method or may be obtained from any commercially available product. Examples of commercially available products of isocyanate crosslinkers may include:l (e.g., L-45E), HL, HX, 2030 and 2031 (east Europe Co., ltd.); />D-102, D-110N, D-200, and D-202 (Mitsui Chemicals Co., ltd.); />24A-100, TPA-100, TKA-100, P301-75E, E402-80B, E402-90T, E405-80T, TSE-100, D-101, and D-201 (asahi chemical corporation (Asahi Kasei Chemical co., ltd.)); />N-75, N-3200, and N-3300 (Sumitomo Bayer Carbamate Co. (Sumika Bayer Urethane Co., ltd.)); />D-370N and D-376N (Mitsui chemical Co., ltd.); and->TP1001 (Nippon Soda co., ltd.). Examples of commercially available products of carbodiimide crosslinking agents may include +.>V-01, V-03, V-05, V-07, V-09 (Niqing spinning chemical Co., ltd.)) and the like. Examples of commercially available products of oxazoline crosslinkers may include +. >WS-300, WS-500, WS-700, K-1000 series, K-2000 series (Nippon Shokubai Co., ltd.), and the like. Examples of commercially available products of the epoxy crosslinking agent may include tetra d-C and tetra d-X (mitsubishi gas science co. (Mitsubishi Gas Kagaku co., ltd.)); ADEKA RESIN EPU series and EPR series (Ai Dike Co., ADEKA Co., ltd.); CELLOXIDE series (Daicel co., ltd.), and the like. Examples of commercially available products of aziridine crosslinking agents may include +.>PZ-33 and DZ-22 (Japanese catalyst Co., ltd.). Examples of commercially available products of peroxides may include +.>ND，/>IB、NPP、IPP、SBP、TCP、OPP、355、L、SA，/>ND、O，/>ND、PV、O、I，/>ND、NHP、PV、O、L、I、A，/>25O、MC、TMH、HC、C、25Z、22，/>PMB、BMT、BW、BMT-K40、BMT-M，A (new japan Oil co., ltdA.).

In the adhesive composition, the (C) component may be present in any amount suitable for polymerization and crosslinking reaction with the (A) component.

When component (C) comprises an isocyanate crosslinking agent (isocyanate group-containing compound), the equivalent ratio (NCO (mole)/OH (mole)) of the total moles of isocyanate groups in the isocyanate group-containing compound to the total moles of hydroxyl groups of component (a) in the adhesive composition is preferably in the range of about 0.2 to about 10. More preferably, the equivalent ratio is in the range of about 0.4 to about 10, still more preferably about 0.5 to about 6. Particularly preferably, the equivalent ratio is in the range of about 1 to about 4.5. Within this range, the adhesive composition can ensure more suitable adhesive strength of the adhesive layer formed therefrom or the adhesive film containing the adhesive layer, and an improvement in suppressing detachment of the adhesive layer can be achieved. The inventors estimated that these effects are achieved by more suitable polymerization and crosslinking reactions with the (a) component. For example, the equivalent ratio (NCO (mole)/OH (mole)) may be about 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 4, 5, 6, 7, 8, 9, or 10. Preferably, the (C) component contains a difunctional isocyanate or a trifunctional or higher-functional isocyanate.

When component (C) comprises an isocyanate crosslinker (isocyanate group-containing compound), the equivalent ratio of the number of moles of isocyanate groups of the difunctional isocyanate to the total number of moles of isocyanate groups of the isocyanate group-containing compound in the adhesive composition (NCO (difunctional) (moles)/NCO (total) (moles)) is preferably in the range of about 0 to about 1. More preferably, the equivalent ratio for the (C) component wherein the isocyanate group-containing compound preferably contains a difunctional isocyanate is from greater than about 0 to about 1 or less. Still more preferably, the equivalent ratio is from greater than about 0 to less than about 1, still more preferably from about 0.25 to less than about 1. Particularly preferably, the equivalent ratio is in the range from about 0.5 to about 0.95, or from about 0.7 to about 0.9. Within this range, the adhesive composition can ensure more suitable adhesive strength of the adhesive layer formed therefrom or the adhesive film containing the adhesive layer. In particular, in the case where the equivalent ratio is greater than or equal to the above lower limit, the adhesive composition can achieve an improvement in suppressing detachment of the adhesive layer. The inventors estimated that these effects are achieved by more suitable polymerization and crosslinking reactions with the (a) component. Further, in the case where the equivalent ratio is less than or equal to the above-described upper limit, the adhesive composition can more effectively prevent the added component such as the (F) component described below from oozing out into the adhesive layer. The inventors estimated that this effect is achieved by increasing the crosslink density to make it more difficult for these components to diffuse into the adhesive layer. For example, the equivalent ratio (NCO (difunctional) (mole)/NCO (total) (mole)) may be about 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.

(C) The component preferably contains trifunctional or higher-functional isocyanate. The trifunctional or higher-functional isocyanate serves to achieve more effective suppression of added components such as the (F) component described below, preventing the added components from exuding into the adhesive layer, while further suppressing the substrate contamination of the adhesive layer. The inventors estimated that these effects are achieved by increasing the crosslink density with the (a) component in the adhesive layer to make it more difficult for the added component to diffuse into the adhesive layer.

When the (C) component contains other crosslinking agents than isocyanate crosslinking agents, the (C) component is preferably present in an amount of about 0.01 to about 20 parts by weight relative to 100 parts by weight of the (A) component. More preferably, the (C) component is present in an amount of about 0.1 parts by weight to about 10 parts by weight relative to 100 parts by weight of the (a) component. More preferably, the (C) component is present in an amount of about 0.5 parts by weight to about 5 parts by weight relative to 100 parts by weight of the (a) component. Within this range, the adhesive composition can ensure more suitable adhesive strength of the adhesive layer formed therefrom or the adhesive film containing the adhesive layer, and an improvement in suppressing detachment of the adhesive layer can be achieved. The inventors estimated that these effects are achieved by more suitable polymerization and crosslinking reactions of the (a) component, (B) component or (co) polymer thereof with the (C) component.

[ (D) component: crosslinked particles ]

The adhesive composition according to the embodiment includes crosslinked particles ((D) component). Herein, crosslinked particles refer to particles at least partially having a crosslinked structure. (D) The component has a function of forming unevenness on the surface of the adhesive layer. Here, the adhesive layer has reduced adhesive strength by formation of unevenness. Thus, the (D) component can contribute to further improving the adhesiveness of the adhesive layer or the adhesive film including the adhesive layer by ensuring proper adhesive strength of the adhesive layer or the adhesive film before irradiation with light. In addition, the (D) component can contribute to improvement of reworkability by further reducing the adhesive strength at the time of reworking. The adhesive composition containing no (D) component exhibits excessive adhesive strength before irradiation with light and undergoes deterioration of adhesion. In addition, the adhesive composition containing no (D) component exhibits excessive adhesive strength and insufficient reworkability after irradiation with light. In particular, the (D) component allows the adhesive composition containing the (meth) acryl group-free crosslinking agent (C) to exhibit a decrease in adhesive strength by irradiation with light.

(D) The components may be selected from any of the well known cross-linked particles without limitation. For example, the (D) component may contain styrene crosslinked particles, (meth) acrylic crosslinked particles ((meth) acrylic crosslinked particle, (meth) acrylic crosslinked particles), fluorine-modified (meth) acrylic crosslinked particles, styrene- (meth) acrylic crosslinked particles, urethane crosslinked particles, silicone crosslinked particles, and the like.

At least 50wt% or more of the styrene cross-linked particles are composed of units derived from styrene monomer.

At least 50% by weight or more of the (meth) acrylic crosslinked particles are composed of constituent units derived from a (meth) acryloyloxy group-containing monomer ((meth) acrylate monomer). Here, the (meth) acrylate monomer may be prepared by, for example, a combination of a well-known monofunctional (meth) acrylate and a well-known multifunctional (meth) acrylate. Preferably, the (meth) acrylic crosslinked particles are crosslinked particles consisting essentially of poly (methyl methacrylate) (PMMA).

At least 50wt% or more of the styrene- (meth) acrylic crosslinked particles are composed of units derived from styrene monomers or units derived from (meth) acrylate monomers.

At least 50wt% or more of the urethane-crosslinked particles are composed of a polymer compound having a urethane bond or a urea bond. Here, the polymer compound having a urethane bond or a urea bond may include, for example, a reaction product of a well-known polyfunctional isocyanate and a polyol or a reaction product of a well-known polyisocyanate and water.

The silicone crosslinked particles may include, for example, crosslinked particles commonly referred to as silicone rubber or silicone resin and composed mainly of a material having a solid phase at room temperature. Preferably, the silicone crosslinked particles comprise a silicone resin powder having a solid phase at room temperature (a cured product of a polyorganosilsesquioxane having a crosslinked structure in which siloxane bonds are a three-dimensional network).

In addition to the above materials, the crosslinked particles may include, for example, crosslinked rubber particles.

Preferably, the crosslinked particles are (meth) acrylic crosslinked particles or silicone crosslinked particles, more preferably silicone crosslinked particles, in terms of compatibility between adhesiveness and reworkability, press workability, wettability and transparency.

(D) The component may be a particle having a core-shell structure in which the core or shell portion has a crosslinked structure that crosslinks the particle. Alternatively, the (D) component may be hollow particles.

Alternatively, the (D) component may be particles having a crosslinked structure and coated with a coating material. The coating material may be selected from well known coating materials, which may be used for particle coating, but is not limited thereto. For example, the coating material may include natural resins, synthetic resins, silicone resins, metals, inorganic compounds, and the like.

(D) The composition may have any shape without limitation. For example, the (D) component may have a spherical shape, an elliptical shape, an irregular shape, a needle shape, a disk shape, a hollow shape, a columnar shape, a tapered shape, or the like. Preferably, in order to reduce the adhesive strength, the (D) component has a spherical shape or an elliptical shape, more preferably a spherical shape.

Preferably, the (D) component has an average particle size (D50) of about 0.5 μm to about 30 μm. More preferably, the (D) component has an average particle size (D50) of from about 0.5 μm to about 25 μm, still more preferably from about 0.5 μm to about 20 μm. In the case where the (D) component has a particle diameter of greater than or equal to the above lower limit, the adhesive layer or the adhesive film containing the adhesive layer exhibits better adhesion and improvement in reworkability. The inventors estimated that these effects are achieved by further increasing the non-uniformity on the surface of the adhesive layer, a more appropriate adhesive strength range, and a decrease in adhesive strength after irradiation with light. In the case where the (D) component has a particle diameter of less than or equal to the above upper limit, the adhesive layer exhibits further improvement in wettability to an adherend. The inventors estimated that this effect is achieved by further reducing the non-uniformity on the adhesive layer surface to make it difficult for air to enter the adhesive surface. Here, "D50" may be measured by typical methods well known to those skilled in the art. For example, "D50" may be the particle size corresponding to 50wt% in the weight cumulative distribution of particles.

Preferably, the (D) component is transparent in terms of transparency of the adhesive film, but is not limited thereto.

(D) The components may be prepared by any well known method or may be obtained from any commercially available product. (D) Examples of commercially available products of the components may include ARTGR series, SE series (e.g., SE-010T, SE-020T, etc.), G series, GS series, J series, MF series, BR series (cross-linked acryl beads, transparent), C series, P series, JB series, U series, CE series, AK series, HI series, MM series, FF series, TK series, C-TH series, RT series, RW series, RX series, RY series, RZ series, RU series, RV series, BP series (cross-linked urethane beads, transparent) (industrial on-root co (Negami industrial co., ltd.)), KMP-600, KMP-601, KMP-602, KMP-605, X-52-7030 (silicone composite powder), KMP-597, KMP-598, KMP-594, X-52-875 (silicone composite powder), KMP-590, KMP-701, X-52-1621 (silicone composite powder) (industrial on-root, industrial chemical Co., ltd.)), KMP-600, KMP-598, KMP-594 (silicone composite powder) and the likeSociety (Shin-Etsu Chemical Industry co., ltd.), etc.

Such crosslinked particles may be prepared by any well known method. For example, crosslinked particles can be prepared by polymerizing (such as suspension polymerization, flake polymerization, emulsion polymerization, etc.) a synthetic crosslinked polymer followed by washing, drying, sorting, etc. Alternatively, crosslinked particles may be prepared by preparing a crosslinked polymer having reactive functional groups, followed by crosslinking the polymer compound.

These crosslinked particles may be used alone or as a mixture thereof.

In the adhesive composition, the (D) component may be present in an amount of about 0.01 parts by weight to about 10 parts by weight (total amount of use of two or more (D) components) relative to 100 parts by weight of the (a) component. In the case where the amount of the (D) component is less than the above lower limit, the adhesive composition exhibits excessive adhesive strength and suffers from adhesive deterioration. In addition, the adhesive layer or the adhesive film including the adhesive layer exhibits excessive adhesive strength and insufficient reworkability upon reworking. In the case where the amount of the (D) component is greater than the above upper limit, the adhesive composition exhibits insufficient adhesive strength and suffers from adhesive deterioration. If the content of the (D) component is excessive, the (D) component is easily separated, resulting in deterioration of press workability. Further, the adhesive layer has excessive surface unevenness, and suffers from deterioration in wettability and transparency to an adherend due to light being easily diffused thereon. More preferably, the (D) component is present in an amount of about 0.05 parts by weight to about 5 parts by weight relative to 100 parts by weight of the (a) component in terms of adhesion, reworkability, press workability, wettability, and transparency. More preferably, the (D) component is present in an amount of about 0.1 parts by weight to about 1 part by weight relative to 100 parts by weight of the (a) component. For example, the (D) component may be present in an amount of about 0.01, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10 parts by weight relative to 100 parts by weight of the (a) component.

[ (E) component: photo radical initiator ]

The adhesive composition according to an embodiment of the present invention includes a photo radical initiator ((E) component). (E) The component generates radicals upon irradiation with light and induces photopolymerization and crosslinking reaction of the (B) component, thereby contributing to improvement of reworkability by reduction of adhesive strength of the adhesive composition after irradiation with light. The adhesive composition containing no (E) component cannot reduce adhesive strength upon irradiation with light, and exhibits insufficient reworkability.

(E) The components may include any well known photo radical initiator without limitation. (E) Examples of the components may include acetophenone compounds, benzoin compounds, benzophenone compounds, thioxanthone compounds, anthraquinone compounds, and acylphosphine oxide compounds. In addition, the (E) component may include 3,3', 4' -tetra (t-butylperoxycarbonyl) benzophenone, acrylated benzophenone, and the like.

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

Examples of the benzoin compound may include benzoin, benzoin methyl ether, benzoin isopropyl ether, benzoin isobutyl ether, and the like.

Examples of the benzophenone compound may include benzophenone, benzoyl benzoate, methylbenzoyl benzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4 '-methyldiphenyl sulfide, 3' -dimethyl-4-methoxybenzophenone, and the like.

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

Examples of the anthraquinone compound may include 4,4' -dimethylaminothioxanthone (also referred to as fresnel's ketone), 4' -diethylaminobenzophenone, α -acyloxime ester, benzyl, methylbenzoyl formate, 2-ethylanthraquinone, and the like.

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

Examples of the acrylated benzophenone may include 3,3', 4' -tetra (t-butyl peroxycarbonate) benzophenone, acrylated benzophenone, and the like.

Preferably, in terms of further improving reworkability of an adhesive layer formed of the adhesive composition or an adhesive film comprising the adhesive layer, the (E) component is an acylphosphine oxide compound, more preferably 2,4, 6-trimethylbenzoyl-diphenyl-phosphine oxide.

(E) The components may be prepared by any well known method or may be obtained from any commercially available product. (E) Examples of commercially available products of the components may include:184,369,651,819,907,1173,TPO H (Ai Jianmeng resin limited (IGM RESINS co., ltd.)); />KIP150 and TZT (DKSH Japan co., ltd.),>BMS and DMBI (Nippon Kayaku Co., ltd.), and the like.

These photo radical initiators may be used alone or as a combination thereof.

In the adhesive composition, the (E) component is preferably present in an amount of about 0.01 parts by weight to about 20 parts by weight (total amount of use of two or more photo radical initiators) relative to 100 parts by weight of the (a) component, but is not limited thereto. More preferably, the (E) component is present in an amount of about 0.1 to about 10 parts by weight, still more preferably about 0.5 to about 5 parts by weight, relative to 100 parts by weight of the (A) component. It is particularly preferred that the (E) component is present in an amount of about 1 part by weight to about 2 parts by weight relative to 100 parts by weight of the (A) component. Within this range, the adhesive composition can ensure further improvement in reworkability of the adhesive layer formed therefrom or the adhesive film including the adhesive layer. The inventors estimated that these effects are achieved by performing more appropriate polymerization and crosslinking reactions with the (B) component upon irradiation with light.

[ (F) component: antistatic agent ]

The adhesive composition according to an embodiment of the present invention further comprises an antistatic agent ((F) component). (F) The components may be used to improve electrical conductivity while reducing the surface resistance of an adhesive layer formed from the adhesive composition. With the antistatic agent, when the adhesive layer that is incorrectly adhered to an adherend such as a liquid crystal cell (liquid crystal cell) is peeled off from the adherend (reworking operation is performed), the adhesive composition can effectively suppress the generation of static electricity. As a result, it is possible to stably prevent foreign substances from adhering to the surface of the polarizing plate or the like, misalignment of the liquid crystal, or electrostatic breakdown of the peripheral circuit element. Adhesive compositions that do not contain component (F) may suffer from excessive increases in stripping electrostatic voltage.

(F) The components may be obtained from typical antistatic agents without limitation. For example, the (F) component may contain an ionic liquid, a surfactant, or an ionic conductive agent, such as bis (fluorosulfonyl) imide salt, or the like.

The ionic liquid may include, for example, cationic components such as phosphonium ions, pyridinium ions, pyrrolidinium ions, imidazolium ions, guanidinium ions, ammonium ions, isouronium ions, thiouronium ions, piperidinium ions, pyrazolium ions, sulfoaluminum ions, quaternary ammonium and quaternary phosphonium; and anionic components such as halogen ions, nitrate ions, sulfate ions, phosphate ions, perchlorate ions, thiocyanate ions, thiosulfate ions, sulfite ions, tetrafluoroborate ions, hexafluorophosphate ions, formate ions, oxalate ions, acetate ions, trifluoroacetate ions, alkylsulfonate ions, and the like.

In particular, the ionic liquid may comprise 1-allyl-3-methylimidazolium 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 (trifluoromethylsulfonyl) imide, 1-methyl-1-methylpyrrolium bromide, 1-butyl-1-methylpiperidinium bromide, 1-ethylpyridinium chloride, 1-ethylpyridinium bromide, 1-butylpyridinium chloride, 1-butylpyridinium bromide, 1-ethyl-3-methylimidazolium hexafluoro phosphate, 1-butyl-3-methylimidazolium chloride, 1-butylpyridinium chloride, 1-4-methylpyridinium chloride, 1-butylpyridinium bromide, 1-methylpyridinium bromide, 1-ethylpyridinium bromide, 1-methylpyridinium chloride, 1-4-methylpyridinium bromide, 1-methylpyridinium chloride, 1-methylpyridinium bromide, and 1-methylpyridinium bromide, tributyl methyl ammonium bis (trifluoromethylsulfonyl) imide (also known as tri-n-butyl methyl ammonium bis-trifluoromethylsulfonyl imide), tetrabutyl ammonium chloride, tetrabutyl ammonium bromide, cyclohexyl trimethyl ammonium bis (trifluoromethylsulfonyl) imide, tetrabutyl phosphonium bromide, and the like.

The surfactant may be a nonionic surfactant or an ionic surfactant.

Examples of the nonionic surfactant may include polyethylene glycol alkyl ether, polyoxyalkylene alkyl ether (polyoxyalkylene alkyl ether), and the like.

Examples of the ionic surfactant may include cationic surfactants (such as C ₈ To C ₂₂ Alkyl trimethyl ammonium halides), anionic surfactants (such as alkyl sulfates), and the like.

Preferably, component (F) is an ionic liquid, more preferably tributyl methyl ammonium bis (trifluoromethylsulfonyl) imide.

(E) The components may be prepared by any well known method or may be obtained from any commercially available product. Examples of commercially available products may include 3M ^TM Ionic liquid antistatic agent FC-4400 (3M Japanese Co., ltd. (3M Japan Co., ltd.)A.).

The antistatic agents may be used alone or as a mixture thereof.

In the adhesive composition, the (F) component is preferably present in an amount of about 0.01 parts by weight to about 30 parts by weight (total amount of use of two or more antistatic agents) relative to 100 parts by weight of the (a) component, but is not limited thereto. More preferably, the (F) component is present in an amount of about 0.1 to about 20 parts by weight, still more preferably about 0.5 to about 15 parts by weight, relative to 100 parts by weight of the (a) component. More preferably, the (F) component is present in an amount of about 2 parts by weight to about 5 parts by weight relative to 100 parts by weight of the (a) component. When the amount of the (F) component is greater than or equal to the above lower limit, the peeling electrostatic voltage of the adhesive layer formed of the adhesive composition or the adhesive film containing the adhesive layer can be further reduced. Further, when the amount of the (F) component is less than or equal to the above upper limit, contamination of the adhesive layer or the adhesive film containing the adhesive layer can be further suppressed.

[ (G) component: stabilizers ]

The adhesive composition according to the embodiment of the present invention may further contain a stabilizer ((G) component) as long as the (G) component does not change the effect of the present invention. (G) The component stabilizes radicals generated by low-intensity light (e.g., ultraviolet light) under light irradiation, and has a function of suppressing a photo-curing reaction of the adhesive composition, a cured product thereof, or an adhesive layer formed therefrom before irradiation with light. Accordingly, the (G) component allows the adhesive composition, the cured product thereof, or the adhesive layer formed therefrom to be stored under the condition of irradiating the adhesive composition, the cured product thereof, or the adhesive layer formed therefrom with low-intensity light (e.g., ultraviolet light) (e.g., under LED light), thereby improving storage performance. On the other hand, since light of high intensity is emitted upon irradiation with light, a large amount of radicals are generated upon irradiation with light and the stabilizing effect of the (G) component is reduced. As a result, even in the presence of the (G) component, the photo-curing reaction of the adhesive composition proceeds upon irradiation with light, resulting in a decrease in the adhesive strength of the adhesive layer. Herein, the stabilizer may include at least one selected from the group consisting of an antioxidant, a light stabilizer, a polymerization inhibitor, and an ultraviolet light absorber.

(G) The component may be selected from any well known stabilizer selected from antioxidants, light stabilizers, polymerization inhibitors and ultraviolet light absorbers, but is not limited thereto. Preferably, the (G) component is an antioxidant or a light stabilizer.

Examples of antioxidants may include hindered phenolic antioxidants, phosphorus-based antioxidants, and the like.

The hindered phenolic antioxidant may include, for example, a compound having a sterically hindered hydroxyphenyl group, but is not limited thereto. Here, the sterically hindered hydroxyphenyl group may include any substituted hydroxyphenyl group having a large volume, but is not limited thereto. For example, sterically hindered hydroxyphenyl groups may include compounds having substituted or unsubstituted alkyl groups at the 2-and 6-positions of the hydroxyphenyl group, but are not limited thereto. Examples of hindered phenolic antioxidants may include triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate]Pentaerythritol-tetrakis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate]Octadecyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, thiodiethylene-bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, phenylpropionic acid 3, 5-bis (1, 1-dimethyl) -4-hydroxy-C ₇ To C ₉ Alkyl esters, 4, 6-bis (dodecylthiomethyl) -o-cresol, 3',3", 5',5" -hexat-butyl-a, alpha ' - (mesitylene-2, 4, 6-triyl) tri-p-cresol, 1,3, 5-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) -1,3, 5-triazine-2, 4,6 (1H, 3H, 5H) -trione, 2, 6-di-tert-butyl-4- (4, 6-bis (octylthio) -1,3, 5-triazin-2-ylamino) phenol, 1, 6-hexanediol-bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ]Ethylene-bis (oxyethylene) bis [3- (5-t-butyl-4-hydroxy-m-triyl) propionate]Hexamethylene-bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate]Isooctyl-3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene, 3, 9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy } -1, 1-dimethylethyl]-2,4,8, 10-tetraoxaspiro [ 5.5 ]]Undecane, N' -hexane-1, 6-diylbis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionamide]N, N' -hexamethylenebis (3, 5-di-tert-butyl-4-hydroxy-hydrocinnamate)Amide), N' -bis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl]Hydrazine, diethyl [ (3, 5-bis (1, 1-dimethylethyl) -4-hydroxyphenyl) methyl ]]Phosphoric acid esters, 3, 5-di-tert-butyl-4-hydroxybenzylphosphonate-diethyl esters, 3',3", 5',5" -hexatert-butyl-a, a ', a "-mesitylene-2, 4, 6-tri-p-cresol, 1, 3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3, 5-tris (4-t-butyl-3-hydroxy-2, 6-dimethyl) isocyanurate, 1,3, 5-tris (4-sec-butyl-3-hydroxy-2, 6-dimethyl) isocyanurate, 1,3, 5-tris (4-neopentyl-3-hydroxy-2, 6-dimethyl) isocyanurate, 2' -methylenebis (4-methyl-6-t-butylphenol), 4' -butylidenebis (4-methyl-6-t-butylphenol), tris- (3, 5-di-t-butyl-4-hydroxybenzyl) isocyanurate, polycondensates of p-chloromethylstyrene and p-cresol, polycondensates of p-chloromethylstyrene and divinylbenzene, isobutylene reactants of p-cresol and divinylbenzene, and the like.

Examples of phosphorus-based antioxidants may include triphenyl phosphate, tris (2, 4-di-tert-butylphenyl) phosphate, diphenyloctyl phosphate, diphenylisodecyl phosphate, phenyldiisodecyl phosphate, tetrakis (2, 4-di-tert-butylphenyl) -4,4' -biphenylene phosphite, trisnonylphenyl phosphite, bis (2, 4-di-tert-butylphenyl) pentaerythritol diphosphite, distearyl pentaerythritol diphosphite, bis (2, 4-di-tert-butylphenyl) pentaerythritol diphosphite, bis (2, 6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2, 4-dicumylphenyl) pentaerythritol diphosphite tetrakis (2, 4-di-tert-butylphenyl) (1, 1-biphenyl) -4,4' -diylbis-phosphonite, di-tert-butyl-m-cresol-phosphonite, distearyl pentaerythritol diphosphite, di (2, 4-di-tert-butylphenyl) -pentaerythritol diphosphite, di (2, 6-di-tert-butyl-4-methylphenyl) -pentaerythritol diphosphite, 4' -butylidene-bis (3-methyl-6-tert-butylphenyl-ditridecyl) phosphite, cyclic neopentane-tetralylbis (octadecyl) phosphite, diisodecyl pentaerythritol diphosphite, 2-methylenebis (4, 6-di-tert-butylphenyl) octyl phosphite, bis (tridecyl) pentaerythritol diphosphite, bis (nonylphenyl) pentaerythritol diphosphite, hydrogenated bisphenol A pentaerythritol phosphite polymer, hydrogenated bisphenol A phosphite polymer, tetraphenyl tetra (tridecyl) pentaerythritol tetraphosphite, tetra (tridecyl) -4,4' -isopropylidenediphenyl diphosphite, tetraphenyl dipropylene glycol diphosphate, and the like.

Light stabilizers may include, for example, hindered amine based light stabilizers (HALS) and the like.

Hindered amine based light stabilizers (HALS) may include, for example, compounds having sterically hindered piperidinyl groups, but are not limited thereto. Here, the sterically hindered piperidinyl group may include any substituted piperidinyl group having a large volume, but is not limited thereto. For example, sterically hindered piperidinyl groups may include compounds having one or two alkyl groups at the 2-and 6-positions of the piperidinyl group, but are not limited thereto. Examples of hindered amine based light stabilizers (HALS) may include bis (1, 2, 6-pentamethyl-4-piperidinyl) sebacate, methyl (1, 2, 6-pentamethyl-4-piperidinyl) sebacate, and 2, 4-bis [ N-butyl-N- (1-cyclohexyloxy-2, 6-tetramethylpiperidin) -4-yl ] amino ] -6- (2-hydroxyethylamine) -1,3, 5-triazine bis (2, 6-tetramethyl-1- (octyloxy) -4-piperidinyl) sebacate, bis (1, 2, 6-pentamethyl-4-piperidinyl) -2-butyl-2- (4-hydroxy-3, 5-di-tert-butylbenzyl) propane diacid ester bis (2, 6-tetramethyl-4-piperidinyl) sebacate, 4- (meth) acryloyloxy-2, 6-tetramethylpiperidine 4- (meth) acrylamido-2, 6-tetramethylpiperidine, 4- (meth) acryloyloxy-1, 2, 6-pentamethylpiperidine 4- (meth) acrylamido-2, 6-tetramethylpiperidine 4- (meth) acryloyloxy-1, 2, 6-pentamethylpiperidine, 1- (meth) acryloyl-4- (meth) acrylamido-2, 6-tetramethylpiperidine 1- (meth) acryloyl-4-cyano-4- (meth) acrylamido-2, 6-tetramethylpiperidine, 1-crotonyl-4-crotonyloxy-2, 6-tetramethylpiperidine, and the like.

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

Examples of the ultraviolet light absorber may include benzophenone-based ultraviolet light absorbers such as 2, 4-dihydroxy-benzophenone, 2-hydroxy-4-methoxy-benzophenone, and the like. In addition, the ultraviolet light absorber may include benzotriazole-based ultraviolet light absorbers such as 2- (2 '-hydroxy-5-methylphenyl) benzotriazole, 2- (2' -hydroxy-3 ',5' -di-tert-butylphenyl) benzotriazole, and the like. In addition, the ultraviolet light absorber may include triazine-based ultraviolet light absorbers such as 2, 4-diphenyl-6- (2-hydroxy-4-methoxyphenyl) -1,3, 5-triazine, 2, 4-diphenyl-6- (2-hydroxy-4-ethoxyphenyl) -1,3, 5-triazine, and the like.

In particular, the stabilizer is preferably an antioxidant or a light stabilizer, more preferably a hindered phenol based antioxidant or a hindered amine based light stabilizer (HALS). More preferably, the stabilizer is pentaerythritol tetrakis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ], bis (1, 2, 6-pentamethyl-4-piperidinyl) sebacate, or methyl (1, 2, 6-pentamethyl-4-piperidinyl) sebacate.

(G) The components may be prepared by any well known method or may be obtained from any commercially available product. Examples of commercially available products based on hindered phenolic antioxidants may include1010、1010FF、1035、1035FF(W&C) 1076, 1076FD, 1098, 1135, 1330, 1530L, 1726, 245FF, 259, 3114, 565 (BASF Japan co., ltd.), etc. Examples of commercially available products of amine-based light stabilizers (HALS) may include +.>111 FDL、123、144、292、5100、123-DW、622 SF、PA 144、765、770DE、XT 55 FB、783 FDL、791 FB、/>2020 FDL, 944 LD (basf japan limited), and the like.

Antioxidants, light stabilizers, polymerization inhibitors or ultraviolet light absorbers may be used alone or as a mixture thereof. The mixture may be a mixture of the same kind of stabilizer compound or a mixture of different kinds of stabilizer compound.

The blend of ultraviolet light absorbers and hindered amine based light stabilizers (HALS) as a mixture of different kinds of stabilizer compounds may include, for example5050. 5060, 5151, 5333-DW (Basf Japanese Co., ltd.) and the like.

For the adhesive composition, the amount of the (G) component (the total amount of two or more stabilizers used) is not particularly limited. However, in order to secure the effect of the (G) component, the amount of the (G) component is not more than about 5 parts by weight with respect to 100 parts by weight of the (a) component. In other words, the (G) component is preferably present in an amount of about 5 parts by weight or less. If the amount of the (G) component exceeds 5 parts by weight, the amount of radicals stabilized by the (G) component upon irradiation with light increases and the photo-curing reaction can be suppressed. More preferably, the (G) component is present in an amount of about 3 parts by weight or less, still more preferably about 0.5 parts by weight, relative to 100 parts by weight of the (a) component. Within this range, the stabilizer does not affect the effect of reducing the adhesive strength of the adhesive layer after irradiation with light. Furthermore, it is desirable that the thermosetting adhesive composition contains the (G) component. In other words, it is desirable that the (G) component is present in an amount of more than 0 parts by weight (total amount of two or more stabilizers used) relative to 100 parts by weight of the (a) component in the thermosetting adhesive composition. This is because the stabilizer can stabilize free radicals generated under the condition of irradiating the adhesive layer with light of low intensity (e.g., ultraviolet light) (e.g., under LED illumination). More preferably, the (G) component may be present in an amount of about 0.01 parts by weight or more, still more preferably about 0.05 parts by weight or more, relative to 100 parts by weight of the (a) component. Within this range, the adhesive composition exhibits further improvement in storage performance under conditions of irradiation with low intensity light (e.g., ultraviolet light) (e.g., under LED illumination). For example, the (G) component may optionally be present in an amount of greater than about 0 to about 5 parts by weight or less relative to 100 parts by weight of the (a) component.

[ other Components ]

The adhesive composition according to the embodiment of the present invention may further contain any well-known additive as long as the additive does not change the effect of the present invention. Examples of the additive may include a curing accelerator, a lithium salt, a filler, a softener, an anti-aging agent, a tackifying resin, a leveling agent, an antifoaming agent, a plasticizer, a dye, a pigment, a treating agent, an optical brightening agent, a dispersing agent, and a lubricant, but are not limited thereto.

[ method of producing adhesive composition ]

The adhesive composition according to embodiments of the present invention may be prepared by any method well known in the art. Adhesive compositions according to embodiments of the present invention are generally prepared by mixing the aforementioned components. There is no limitation on the mixing method. The mixing method may be a method of simultaneously mixing the above components; a method of sequentially mixing the above components; or a method of mixing some of the above components and then adding other components thereto. Preferably, the above components are mixed and stirred to obtain a homogeneous mixture. Here, the stirring may be performed using a stirrer where light of a specific wavelength is shielded, as needed, until the mixture becomes homogeneous. Alternatively, stirring may be performed using a stirrer as needed until the mixture becomes homogeneous after heating the mixture. Here, the stirring may be performed for, for example, 10 minutes to 5 hours, but is not limited thereto. Here, the mixture may be maintained at a temperature of, for example, 30 to 40 ℃, but is not limited thereto.

Another embodiment of the present invention is directed to an adhesive composition solution comprising an adhesive composition and a solvent. Herein, the term "adhesive composition solution" refers to a solution or dispersion comprising an adhesive composition and a solvent. Here, the adhesive composition solution may be used to improve the homogeneity of the adhesive composition by mixing, or may be used as a coating solution for forming an adhesive layer described below.

In the preparation of the adhesive composition or dispersion, it is desirable to use a solvent (or dispersion medium). Preferably, the solvent is an organic solvent, but is not limited thereto. Examples of the organic solvent may include toluene, ethyl acetate, butyl acetate, methyl ethyl ketone, hexane, acetone, cyclohexanone, 3-pentanone, acetonitrile, propionitrile, isobutyronitrile, valeronitrile, dimethyl sulfoxide, dimethylformamide, and the like. Preferably, the organic solvent is methyl ethyl ketone or ethyl acetate. These organic solvents may be used alone or as a combination thereof.

In the adhesive composition solution, the adhesive composition is preferably present in an amount of 20wt% to 99 wt%. More preferably, the thermosetting adhesive composition is present in an amount of 30wt% to 95 wt%. Within this range, the adhesive composition solution can improve the dryability of the adhesive layer formed of the adhesive composition, and ensure improved coatability when used as a coating solution.

In another aspect, the preparation and storage of the adhesive composition and the adhesive composition solution is preferably performed under light-protected conditions. For example, when the adhesive strength of the adhesive composition can be reduced by irradiation with light, it is desirable that the preparation and storage of the adhesive composition and the adhesive composition solution be performed in an environment shielded from ultraviolet light (for example, in a yellow room). Under these conditions, the photo-curing reaction of the adhesive composition can be suppressed while further improving the decrease in the adhesive strength of the adhesive layer after irradiation with light.

< adhesive layer and method for producing the same >

Another embodiment of the present invention is directed to a heat cured product of the above adhesive composition. Yet another embodiment of the present invention relates to an adhesive layer comprised of the heat cured product of the adhesive composition. Here, as described above, preferably, the adhesive composition is a thermosetting adhesive composition and the cured product is a thermosetting product.

As described above, the heat-cured product refers to a cured product formed by thermal crosslinking. The heat-cured product does not necessarily need to be heated, and may include a cured product formed at room temperature (20 ℃ to 25 ℃).

The heat-cured product of the adhesive composition according to the embodiment of the present invention reduces the adhesive strength by irradiation with light. Therefore, the adhesive layer according to the embodiment of the present invention exhibits good adhesion in a bonded state and exhibits remarkable reworkability when irradiated with light. Here, the ratio of the adhesive strength of the adhesive layer after the light irradiation to the adhesive strength of the adhesive layer before the light irradiation is preferably the same as the ratio of the adhesive strength of the adhesive film described below after the light irradiation to the adhesive strength of the adhesive film before the light irradiation.

Preferably, in terms of compatibility between adhesiveness and reworkability, the adhesive strength of the adhesive layer is in the same range as that of the adhesive film described below. Here, the adhesive strength may be measured using a tensile tester, and details of the measurement method will be described in the embodiments.

Preferably, in terms of compatibility between adhesiveness and reworkability, the adhesive strength of the adhesive layer after irradiation with light is in the same range as that of the adhesive film described below after irradiation with light. Here, the adhesive strength after irradiation with light can be measured using a tensile tester, and details of the measurement method will be described in the embodiments. Further, the kind and intensity of light required for the light irradiation treatment of the adhesive layer are the same as those of the light irradiation treatment of the adhesive film described below.

The adhesive layer may be formed by any method known in the art without limitation. Preferably, the adhesive layer is formed by applying an adhesive composition or an adhesive composition solution to the support to form a coating layer, followed by heat-drying or heat-treating the coating layer as needed.

The thickness of the coating layer (thickness after drying, thickness of the adhesive layer) of the adhesive composition is not particularly limited. When the adhesive composition is used to form an adhesive layer or an adhesive film, the coating thickness of the adhesive composition may be determined according to the kind of the substrate. Preferably, the adhesive composition is coated to a thickness of 1 μm to 500 μm. More preferably, the adhesive composition is coated to a thickness of 10 μm to 300 μm, still more preferably 20 μm to 200 μm.

Here, the coating may be performed by any well-known method. For example, the coating can be performed using a natural coater, a knife-belt coater, a floating knife coater, a roll-blade coater, a felt-belt coater, a spray coater, a dip coater, a kiss roll coater, a squeeze roll coater, a reverse roll coater, an air-knife coater, a curtain coater, a blade coater, a wire coater, a die coater, a comma coater, a bake coater, a gravure coater, or the like.

When the adhesive composition itself is used to form the adhesive layer, the heat treatment of the adhesive composition may be performed at any temperature without limitation. For the thermosetting adhesive composition, the heat treatment may be carried out at any temperature suitable for crosslinking without limitation. Preferably, the heat treatment is carried out at a temperature of 20 ℃ to 150 ℃, more preferably 40 ℃ to 150 ℃. Still more preferably, the heat treatment is carried out at a temperature of 50 ℃ to 140 ℃, particularly preferably 80 ℃ to 130 ℃. In this case, the heat treatment of the adhesive composition may be performed for any period of time without limitation. For thermosetting adhesive compositions, the heat treatment may be carried out for any period of time suitable for crosslinking. Preferably, the heat treatment is performed for a period of time of 5 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, still more preferably 1 minute to 7 minutes. Under the above heat treatment conditions, crosslinking of the adhesive composition can be more suitably performed, thereby allowing the formation of an adhesive layer exhibiting better adhesion.

Further, when the adhesive layer is formed using the adhesive composition solution, the heat drying treatment of the adhesive composition solution may be performed at any temperature without limitation. For the thermosetting adhesive composition, the heat-drying treatment may be carried out at any temperature suitable for crosslinking without limitation. Preferably, the heat drying treatment is performed at a temperature of 40 ℃ to 150 ℃, more preferably 50 ℃ to 140 ℃, still more preferably 80 ℃ to 130 ℃. In this case, the heat drying treatment may be performed for any period of time without limitation. For thermosetting adhesive compositions, the heat drying treatment may be carried out for any period of time suitable for crosslinking. Preferably, the heat drying treatment is performed for a period of time of 5 seconds to 20 minutes, more preferably 30 seconds to 10 minutes, still more preferably 1 minute to 7 minutes. Under the above-mentioned heat-drying treatment conditions, the solvent can be sufficiently removed. In addition, crosslinking of the thermosetting adhesive composition can be more suitably performed, thereby forming an adhesive layer exhibiting better adhesion.

In addition, in the formation of the adhesive layer, aging is preferably performed after coating and heat treatment or heat drying treatment. By aging, crosslinking can be more suitably performed, thereby forming an adhesive layer exhibiting better adhesion. The aging may be performed under any well known conditions for forming an adhesive layer. Preferably, the aging is carried out at a temperature of 10 ℃ to 40 ℃, more preferably at room temperature (20 ℃ to 25 ℃). Further, aging is preferably performed at 10% RH (relative humidity) to 80% RH, more preferably at 40% RH to 50% RH. Further, aging is preferably performed for 1 to 7 days. For example, aging is performed at 23℃and 50% RH for 7 days. Under the aging conditions described above, crosslinking of the adhesive composition can be more suitably performed, thereby forming an adhesive layer exhibiting better adhesion.

Preferably, the aging is performed with stacking the support, the coating subjected to the heat drying treatment or the heat treatment, and the release film described below in this order.

On the other hand, the formation and storage of the adhesive layer is preferably performed under light-shielding conditions. For example, when the adhesive strength of the adhesive composition and its heat-cured product is reduced due to irradiation with light, it is desirable that the formation and storage of the adhesive composition and the heat-cured product be performed in an environment shielded from ultraviolet light (for example, in a yellow room). Under these conditions, it is possible to suppress the photo-curing reaction of the adhesive composition and its cured product and achieve further improvement in the effect of reducing the adhesive strength of the adhesive layer after irradiation with light.

< adhesive film >

Yet another embodiment of the present invention relates to an adhesive film comprising a substrate and an adhesive layer (i.e., the adhesive layer described above) formed from the cured product of the adhesive composition according to the present invention. In other words, this aspect relates to an adhesive film comprising a substrate and an adhesive layer composed of the cured product of the adhesive composition described above. Here, as described above, preferably, the adhesive composition is a thermosetting adhesive composition, and the cured product is a thermosetting product. The details of the adhesive layer are the same as described above.

Preferably, the adhesive film is a surface protective film. Surface protective films refer to films that adhere to the surfaces of various optical components and various devices for the purpose of surface protection during the manufacture of the product or until the end product is used.

The adhesive layer may be provided on at least one surface of the substrate directly or via another member therebetween. Preferably, the adhesive layer is provided on one surface of the substrate directly or via another member therebetween.

The matrix may be selected from any well known materials without limitation. Preferably, the substrate is a resin film. The resin film has good properties such as high surface protection, easy handling and high transparency, which are necessary for an adhesive film (particularly, a surface protective film). The resin film may be formed of any well-known resin material without limitation. Herein, "a film composed mainly of a resin" means that the content of the corresponding resin is 50wt% or more based on the total amount of the resin film. Preferably, the content of the resin is 70wt% or more, more preferably 80wt% or more based on the total amount of the resin film. More preferably, the content of the resin is 90wt% or more, particularly preferably 95wt% or more, based on the total amount of the resin film (upper limit: 100 wt%).

Examples of the resin film may include a film composed mainly of a resin (such as a polyester resin, a cellulose resin, a polycarbonate resin, an acrylic resin, a styrene resin, an olefin resin, a polyamide resin, or the like). The polyester resin may include, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate, and the like. The cellulose resin may include, for example, diacetyl cellulose, triacetyl cellulose, and the like. The acrylic resin may include, for example, poly (methyl (meth) acrylate) and the like.

Examples of the styrene resin may include polystyrene, acrylonitrile-styrene copolymer, and the like. Examples of the olefin resin may include polyethylene, polypropylene, polyolefin having a cyclic structure (preferably norbornene structure), ethylene-propylene copolymer, and the like. Examples of the polyamide resin may include nylon 6, aromatic polyamide, and the like. Preferably, the resin film is a film composed mainly of a polyester resin (polyester resin film). More preferably, the resin film is a film (PET film) composed mainly of polyethylene terephthalate. The above resin materials constituting the resin film may be used alone or as a combination thereof.

The substrate preferably has a thickness of 10 μm to 500 μm. More preferably, the substrate has a thickness of 20 μm to 200 μm, still more preferably 40 μm to 100 μm.

The resin film may be subjected to surface treatment. Here, the surface treatment may be performed by any well-known surface method without limitation.

The adhesive film may further comprise members other than the base and the adhesive layer. Examples of the member may include various members for typical adhesive layers well known in the art. For example, the member may include an intermediate layer interposed between the substrate and the adhesive layer, or a release film bonded to a surface of the adhesive layer opposite the substrate. Preferably, the member is a release film. The intermediate layer or release film may include any well known intermediate layer or release film commonly used for adhesive films.

The release film may include, for example, a polyethylene terephthalate film surface-treated with a silicone release agent. Commercially available products of the release film may include, for example, DIAMRF38 (Mitsubishi Resin co., ltd.), and the like.

The adhesive film according to the embodiment of the present invention may be prepared by any well-known method without limitation. Preferably, the adhesive film is prepared by applying the adhesive composition itself or the adhesive composition solution to a substrate, followed by a heat-drying treatment or a heat treatment as needed.

A preferable example of the adhesive film according to the embodiment of the present invention is a surface protective film including a resin film and an adhesive layer provided on the resin film and composed of a cured product of the above-described adhesive composition.

In another aspect, the preparation and storage of the adhesive film is preferably performed under light-shielding conditions. For example, when the adhesive strength of the adhesive composition and its cured product is reduced due to irradiation with light, it is desirable that the preparation and storage of the adhesive composition and the cured product be performed in an environment shielded from ultraviolet light (for example, in a yellow room). Under these conditions, it is possible to suppress the photo-curing reaction of the adhesive composition and its cured product and achieve further improvement in the effect of reducing the adhesive strength of the adhesive layer after irradiation with light.

Further, the adhesive strength of the adhesive layer of the adhesive film according to this embodiment is reduced by irradiation with light. Accordingly, the adhesive film according to the embodiment of the present invention may exhibit significantly excellent reworkability by light irradiation at the time of reworking while exhibiting very good adhesion in a bonded state. According to an embodiment of the present invention, the ratio of the adhesive strength after irradiation of the adhesive film to the adhesive strength of the adhesive film before irradiation with light may have any value less than 100%. Lower post-irradiation bond strength ratios indicate better reworkability. When the adherend is a glass plate, the adhesive film (particularly, a surface protective film) according to the embodiment of the invention preferably has an adhesive strength ratio after irradiation of 0% to 75%. More preferably, the adhesive film has an adhesive strength ratio after irradiation of 0% to 55%, still more preferably 0% to 35%. More preferably, the adhesive film has an adhesive strength ratio after irradiation of 0% to 30%. Particularly preferably, the adhesive film has an adhesive strength ratio after irradiation of 0% to 20%.

The adhesive film according to the embodiment of the present invention may have any adhesive strength before irradiation with light. When the adherend is a glass plate, the adhesive film (particularly, the surface protective film) according to the invention preferably has an adhesive strength of 5g/25mm to 20g/25 mm. More preferably, the adhesive film has an adhesive strength of 6g/25mm to 15g/25mm, still more preferably 8g/25mm to 14g/25 mm. Within this range, the adhesive film may have a high compatibility between the adhesiveness and reworkability. Here, the adhesive strength may be measured using a tensile tester, and details of the measurement method will be described in the embodiments.

The adhesive film according to the embodiment of the present invention may have any adhesive strength after irradiation, which is lower than the adhesive strength before irradiation with light. For the adhesive film, a lower adhesive strength after irradiation is preferable in terms of reworkability. When the adherend is a glass plate, the adhesive film (particularly, the surface protective film) according to the embodiment of the invention may have any adhesive strength after irradiation, which is lower than the adhesive strength before irradiation with light. Preferably, the adhesive film has an adhesive strength after irradiation of less than 5g/25 mm. More preferably, the adhesive film has an adhesive strength after irradiation of 3g/25mm or less, still more preferably 2.5g/25mm or less (lower limit: 0g/25mm or less). Here, the adhesive strength after irradiation may be measured using a tensile tester, and details of the measurement method will be described in the examples.

The adhesive film according to the present invention may have a peel strength ratio of about 70% or more (more preferably about 70% to about 100%, for example, 70%, 75%, 80%, 85%, 90%, 95% or 100%) as calculated by equation 1 in terms of suppressing the contamination of the substrate. Within this range, contamination of the protective film base body can be prevented:

[ equation 1]

Peel strength ratio = PS2/PS1 x 100,

(in equation 1, PS1 represents the peel strength at the peeling rate of 300mm/min at a peeling angle of 180℃under the condition of 23℃X 50% RH (unit: g/25 mm) when the adhesive sheet was peeled from alkali-free glass,

PS2 represents the peel strength at a peel angle of 180℃at a peel rate of 300mm/min when the adhesive sheet was peeled from the alkali-free glass plate at 23℃X 50% RH (unit: g/25 mm) after the adhesive sheet was adhered to the surface of the alkali-free glass plate, wherein the adhesive film according to the present invention had been adhered to the surface of the alkali-free glass plate, left at 40℃for 2 weeks, and removed from the alkali-free glass plate at a peel angle of 180℃at a peel rate of 2400 mm/min.

The adhesive sheet may be the adhesive sheet prepared in the examples, but is not limited thereto.

The adhesive film according to the present invention may have a wet out of less than 5 seconds. With this wettability, the adhesive film can be adhered to an adherend in a short time, thereby improving workability. Wettability can be measured by the following method. An adhesive sheet was prepared by adhering a PET film to the upper surface of the adhesive film and cutting into rectangular specimens having dimensions of 25mm×200mm (width×length), which were in turn adhered to the surface of an alkali-free glass plate such that only the lower surface of the adhesive film was adhered to the surface of the glass plate in a region of 5mm×25mm (length×width). Then, the specimen was temporarily ensured so that an angle of 20 ° to 30 ° was defined between the surface of the alkali-free glass plate and the adhesive film, and then the period of time during which the adhesive film was wet and spread on the surface of the alkali-free glass plate when the specimen was adhered to the surface of the alkali-free glass plate only by its weight was measured. Fig. 1 is a graph showing evaluation of wettability. For details on fig. 1, reference is made to the wettability evaluation described below.

The kind of light used in the irradiation is not particularly limited as long as the polymerization and crosslinking of the (B) component and the (E) component can be achieved by irradiation with light. The kind of light used for irradiation may be appropriately selected depending on the kinds of the (E) component and the (B) component. The light is preferably ultraviolet light, more preferably ultraviolet light having a wavelength of 200nm to 400nm, in terms of controllability, operation and cost.

The light source used for illumination may be selected from any light source known in the art without limitation. For irradiation with ultraviolet light, the light source may include, for example, a metal halide lamp, a high-pressure mercury lamp, an ultraviolet LED lamp, a low-pressure mercury lamp, a xenon arc lamp, a carbon arc lamp, an excimer lamp, an ultraviolet laser, or the like.

The irradiation may be performed at any suitable dose. For irradiation with ultraviolet light, it is preferably at 50mJ/cm ² To 5000mJ/cm ² Is irradiated at a dose of (a). More preferably at 100mJ/cm ² To 3000mJ/cm ² Still more preferably 300mJ/cm ² To 1500mJ/cm ² Is irradiated at a dose of (a).

For the adhesive film according to the embodiment of the present invention, it is desirable that the adhesive strength before irradiation with ultraviolet light after the LED stability test is performed (adhesive strength after the LED stability test is performed) is not changed from the adhesive strength before irradiation with ultraviolet light after manufacturing and storage under the ultraviolet light shielding condition. Here, for the LED stability test, the adhesive film manufactured and stored under ultraviolet light shielding conditions was left under LED illumination (500 lux) at 23 ℃ and 50% rh for 15 days (360 hours). The value obtained by dividing the adhesive strength of the adhesive film after the LED stability test by the adhesive strength of the adhesive film before irradiation with ultraviolet light after manufacturing and storage under the ultraviolet light shielding condition is referred to as an adhesive strength ratio. When the adherend is a glass plate, the adhesive film (particularly, the surface protective film) according to the embodiment of the invention preferably has an adhesive strength ratio (glass adhesive strength ratio) of 0.8 to 1.2.

For the adhesive film according to the embodiment of the present invention, it is desirable that the adhesive strength after ultraviolet light irradiation of the adhesive film after the LED stability test (the adhesive strength after ultraviolet light irradiation after the LED stability test) is not changed from the adhesive strength after ultraviolet light irradiation of the adhesive film manufactured and stored under the ultraviolet light shielding condition. Here, for the LED stability test, the adhesive film manufactured and stored under ultraviolet light shielding conditions was left under LED illumination (500 lux) at 23 ℃ and 50% rh for 15 days (360 hours). The value obtained by dividing the ultraviolet light-irradiated adhesive strength of the adhesive film after the LED stability test by the ultraviolet light-irradiated adhesive strength of the adhesive film manufactured and stored under the ultraviolet light shielding condition is referred to as an ultraviolet light-irradiated adhesive strength ratio. When the adherend is a glass plate, the adhesive film (particularly, the surface protective film) according to the embodiment of the invention preferably has an ultraviolet light-irradiated adhesive strength ratio (ultraviolet light-irradiated glass adhesive strength ratio) of 1.2 or less (lower limit: 0).

The peeling electrostatic voltage of the adhesive film according to the embodiment of the present invention is not particularly limited. A lower absolute peel static voltage value is preferred for good processability in the case of the adhesive film being uncharged after peeling. The adhesive film (particularly the surface protective film) according to the embodiment of the present invention preferably has an absolute peeling electrostatic voltage value of 10kV or less. More preferably, the adhesive film has an absolute peel static voltage value of 2kV or less, still more preferably 0.5kV or less. Still more preferably, the adhesive film has an absolute peel electrostatic voltage value of 0.3kV or less, still more preferably 0.2kV or less (lower limit: 0 kV). Here, the peeling electrostatic voltage may be measured using a potentiometer, and details of the measurement method will be described in the embodiments.

The adhesive film according to the embodiment of the present invention is preferably transparent. Transparency can generally be evaluated based on transmittance and haze.

The transmittance of the adhesive film according to the embodiment of the present invention is not limited to a specific value. Preferably, the adhesive film has a transmittance of approximately 100% in terms of more precisely inspecting the target product having the adhesive film adhered thereto. The adhesive film (particularly, the surface protective film) according to the embodiment of the present invention preferably has a transmittance of 85% or more, more preferably 90% or more (upper limit: 100%). The transmittance may be measured using a haze meter, and details of the measurement method will be described in the embodiments.

The haze of the adhesive film according to the embodiment of the present invention is not limited to a specific value. Preferably, the adhesive film has a lower haze value in terms of more precisely inspecting the target product having the adhesive film adhered thereto. The adhesive film (particularly, the surface protective film) according to the embodiment of the present invention preferably has a haze of 3% or less, more preferably 2% or less (lower limit: 0%). Haze can be measured using a haze meter, and details of the measurement method will be described in the embodiments.

Mode for the invention

Next, the effects of the present invention will be described in more detail with reference to examples and comparative examples. It should be noted, however, that these examples are provided for illustration only and should not be construed as limiting the invention in any way.

Each thermosetting adhesive composition was prepared in the following order. Herein, the preparation and storage of the thermosetting adhesive composition and the manufacture and evaluation of the surface protective film are performed in a yellow room configured to shield ultraviolet light. In other words, except for the case where ultraviolet light is intentionally used in the following evaluation, the thermosetting adhesive composition and the surface protective film exist under ultraviolet light shielding conditions until the evaluation after the production thereof is completed.

< preparation of adhesive composition >

[ preparation of thermosetting adhesive composition 1 ]

100 parts by weight of ARTUN5500P (Negami Industry co., ltd.) (as component (a)) was blended with 35 parts by weight of TMPTA (as component (B)) and 5.3 parts by weight of TMPTA (as component (B))D101 (Asahi chemical Co., ltd. (Asahi Kasei Chemical Co., ltd.)) and 3.9 parts by weight of>E402-80B (Asahi Kasei chemical Co., ltd.) (as component (C)), 1 part by weight of SE-010T (manufactured by Kogyo Co., ltd.) (as component (D)), 1 part by weight of- >TPOH (Ai Jianmeng resin Co., ltd.) (as the (E) component) and 2 parts by weight of 3M ^TM FC4400 (ionic liquid type antistatic agent) (3M Japan limited (3M Japan Co., ltd.))) (as the (F) component), thereby preparing the thermosetting adhesive composition 1. Then, ethyl acetate was added to the thermosetting adhesive composition 1 so that the total concentration of the components was 50wt%, thereby preparing an adhesive composition solution 1.

[ preparation of thermosetting adhesive compositions 2 to 23 ]

Each thermosetting adhesive composition was prepared in the same manner as that for thermosetting adhesive composition 1 except for the variation in the kind and content of each component as listed in tables 1 to 4. Then, each adhesive composition solution was prepared as in the preparation of thermosetting adhesive composition 1.

The components of each thermosetting adhesive composition are shown in tables 1 to 4. In these tables, NCO groups represent isocyanate groups. Detailed information of each component in tables 1 to 4 is as follows. In addition, components not shown in table 4 are not used to prepare each of the thermosetting adhesive compositions shown in table 4.

[ (A) component: urethane prepolymer having at least two hydroxyl groups

A1:ART UN5500P (urethane prepolymer having hydroxyl groups at both ends, acryloxy groups at side chains, and having a polyether skeleton) (manufactured by kagaku corporation);

[ (B) component: multifunctional (meth) acrylate ]

B1: TMPTA (trimethylolpropane triacrylate, hydroxyl number: 0 mg. KOH/g).

[ (C) component: crosslinking agent ]

C1：D101 (difunctional isocyanate (HDI)) (Xuhao chemical Co., ltd.)

C2：E402-80B (elastic trifunctional isocyanate) (Asahi chemical Co., ltd.)

C3：TCP (bis (4-t-butylcyclohexyl) peroxydicarbonate) (Japan Petroleum Co., ltd.)>

[ (D) component: crosslinked particles ]

D1: SE-010T ((meth) acrylic crosslinked particles, acryl crosslinked beads, average particle diameter: 10 μm, (Gen Kogyo Co., ltd.)

D2: SE-020T ((meth) acrylic crosslinked particles, acryl crosslinked beads, average particle diameter: 19 μm, (Gen Kogyo Co., ltd.)

D3: x-52-854 (silicone crosslinked particles, silicone resin powder, average particle diameter: 0.7 μm) (Shin-Etsu Chemical Industry Co., ltd.)

[ (E) component: photo radical initiator ]

E1：TOP H (2, 4, 6-trimethylbenzoyl-diphenylphosphine oxide) (Ai Jianmeng resin Co., ltd.)

[ (F) component: antistatic agent ]

F1：3M ^TM FC4400 (Ionic liquid antistatic agent) (tri-n-butyl methyl ammonium bis (trifluoromethanesulfone) imide) (3M Japanese Co., ltd.)

[ (G) component: stabilizers ]

G1：1010 (pentaerythritol-tetrakis [3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate]Hindered phenol-based antioxidant) (BASF Japan limited (BASF Japan co., ltd.)

G2：292 (mixture of bis (1, 2, 6-pentamethyl-4-piperidinyl) sebacate and methyl (1, 2, 6-pentamethyl-4-piperidinyl) sebacate, hindered Amine Light Stabilizer (HALS)) (basf japan limited)

< preparation of surface protective film (adhesive film) ]

[ preparation of surface protective film 1 ]

A75 μm thick polyethylene terephthalate (PET) film having one surface treated with Antistatic (AS) was prepared. The prepared adhesive composition solution was coated to a post-drying thickness of 75 μm on the surface of the PET film opposite to the one surface subjected to AS treatment. The coating on the PET film was then dried in a hot air circulation oven at 120℃for 5 minutes, thereby forming a PET filmAnd forming an adhesive layer thereon. Then, a release film (38 μm thick PET film surface-treated with silicone release agent, DIA)MRF38, mitsubishi resin Co., ltd.) was bonded to the surface of the adhesive layer (opposite the PET film). Then, the laminate of the PET film, the adhesive layer and the release film was left for 7 days at 23 ℃ x 50% rh, thereby preparing a surface protective film 1.

[ preparation of surface protective films 2 to 23 ]

A surface protective film was produced in the same manner as the surface protective film 1 was produced, except that the adhesive composition solutions 2 to 23 were used instead of the adhesive composition solution 1.

< evaluation of surface protective film 1>

The following properties of each of the prepared surface protective films 1 to 18 were evaluated. The results are shown in tables 1 to 3.

[ adhesive Strength (adhesion) to glass ]

Each of the prepared surface protective films was cut into dimensions of 25mm×200mm (width×length). Then, an alkali-free glass plate (EAGLE)Corning company (Corning inc.) presses on the surface of the adhesive layer from which the surface protective film of the release film is removed. A rubber roller (roller coated with a rubber layer of 6mm thickness, width: 45mm, diameter (including rubber layer): 95mm, surface spring hardness: 80 Hs) weighing 2000g was used for pressing. Then, the surface protective film was left for 3 hours, and then the peel strength at the time of peeling the surface protective film from the alkali-free glass plate was measured. The peel strength was measured by peeling the surface protective film from an alkali-free glass plate using a tensile tester (ta.xt plus, stabilized microsystems company (Stable Micro Systems)) at a peel angle of 180 ° and a peel rate of 2400mm/min at 23 ℃ x 50% rh. The measured value was defined as the glass adhesion strength (unit: g/25 mm) of the surface protective film. The surface protective film having a peel strength in the range of 5g/25mm to 20g/25mm was evaluated as having a good glass adhesion strength 。

[ adhesive Strength (reworkability) of glass after ultraviolet light irradiation ]

Each of the prepared surface protective films was cut into dimensions of 25mm×200mm (width×length). Then, by the same method as that for evaluating the adhesive strength of glass, an alkali-free glass plate (EAGLECorning company (Corning inc.) presses on the surface of the adhesive layer from which the surface protective film of the release film is removed. Then, the surface protective film was left for 3 hours, and the adhesive layer was cured by irradiating the surface protective film with ultraviolet light on the PET film side so that the ultraviolet light passed through the PET film. Here, a metal halide lamp was used at 300mJ/cm under conditions of 23 ℃ X50% RH ² Is irradiated by ultraviolet light. Then, the glass adhesion strength of the surface protective film was measured in the same manner as the glass adhesion strength described above. The measured value was defined as the glass adhesion strength (unit: g/25 mm) of the surface protective film after ultraviolet light irradiation. Although the surface protective film may have any glass adhesive strength after ultraviolet light irradiation as long as the glass adhesive strength after ultraviolet light irradiation is lower than the glass adhesive strength, the surface protective film having the glass adhesive strength after ultraviolet light irradiation of less than 5g/25mm is evaluated as having good glass adhesive strength after ultraviolet light irradiation.

[ frequency of detachment of adhesive layer ]

The release film was peeled from each surface protective film. Then, the adhesive residue on the adhesive layer was examined according to the scratch hardness test method described in JIS K5600-5-4:1999. Specifically, it is formed of SUS and has a sharp tip (diameter:) The pen of (2) was pressed against the surface of the adhesive layer at an angle of 45 degrees under a load of 500g and 1000g, then slid over the surface for 2cm, and then the adhesive layer was checked for adhesive residues. It has been demonstrated that the frequency of detachment of the adhesive layer during stamping corresponds to the extent of the generation of adhesive residues. Thus, the test knotThe result can be used as an index of press workability. Each surface protective film was evaluated for press workability according to the following criteria. When rated as "Δ" or higher, the surface protective film was evaluated as having good press workability.

(evaluation criteria)

And (3) the following materials: no adhesive residue at 1000g load

O: although adhesive residue was produced at 1000g load, there was no adhesive residue at 500g load

Delta: producing adhesive residue on a portion of the surface of the adhesive layer under a load of 500g

X: generating adhesive residues on the entire surface of the adhesive layer under a load of 500g

[ stripping static Voltage ]

Alkali-free glass plates (EAGLE)Corning corporation) is pressed onto the surface of each of the prepared surface protective films. The surface protective film was left to stand for 3 hours after pressing, and peeled from the alkali-free glass plate in the same manner as the measurement of the glass adhesion strength described above. Here, the potential of the surface protective film generated at the time of peeling was measured. Potentiometer (, which is placed at a height of 30mm from the center of the surface protective film, was used at 23℃and 50% RH>DZ4, japan electrostatic appliances corporation (Shishido Electrostatic co., ltd.)) measured the potential of the surface protective film. The measured value is defined as the stripping electrostatic voltage (kV) of the surface protective film. Lower stripping static voltage values are preferred.

[ contamination of substrate ]

Adhesive (SK)2137, soken Chemical Co., ltd&Engineering co., ltd.)) and crosslinking agent (TD-75The Hearing chemical and engineering Co., ltd.) and additives (A-50, hearing chemical and engineering Co., ltd.) were mixed at a weight ratio of 100/0.1/0.1 in terms of solid content, and ethyl acetate (solvent) was then added to the mixture, thereby preparing a solution. Then, the prepared solution was coated to form a coating on the base film (Cosmo- >A4300, polyester film, thickness: an adhesive film having a dry thickness of 25 μm was formed on 75 μm, dongyang limited (Dongyang co., ltd.). Then, a release film (PET 38E0010 BG, gamboge industrial co., fujimori Kogyo co., ltd.) was adhered to the surface of the base film (opposite to the adhesive layer). Then, the laminate of the base film, the adhesive layer and the release film was left at room temperature for 1 week, thereby preparing an adhesive sheet.

Then, the surface protective film was pressed against an alkali-free glass plate (EAGLECorning corporation). Thereafter, the surface protective film was left at 40 ℃ for 2 weeks, and peeled from the alkali-free glass plate as measured for the glass adhesion strength.

Next, the prepared adhesive sheet was pressed against each of (i) the surface of a new alkali-free glass plate and (ii) the surface of an alkali-free glass plate from which the adhesive sheet was removed. A rubber roller (roller coated with a rubber layer of 6mm thickness, width: 45mm, diameter (including rubber layer): 95mm, surface spring hardness: 80 Hs) weighing 2000g was used for pressing. Then, the peel strength at the time of peeling the adhesive sheet from the alkali-free glass plate was measured. The peel strength was measured by peeling the adhesive sheet from the alkali-free glass plate at a peeling angle of 180℃and a peeling rate of 300mm/min using a tensile tester at 23℃X 50% RH. As a result, the ratio (%) of the peel strength (g/25 mm) when the adhesive sheet was peeled from the alkali-free glass plate after the surface protective film was removed therefrom to the peel strength (g/25 mm) when the adhesive sheet was peeled from the new alkali-free glass plate was calculated. Glass contamination of each surface protective film was evaluated according to the following criteria. "DELTA" or higher indicates that the surface protective film had good glass contamination.

(evaluation criteria)

And (3) the following materials: the peel strength (g/25 mm) ratio at the time of peeling the adhesive sheet from the alkali-free glass plate after removing the surface protective film from the alkali-free glass plate is 90% or more

O: the ratio of peel strength (g/25 mm) at the time of peeling the adhesive sheet from the alkali-free glass plate after removing the surface protective film from the alkali-free glass plate is 80% to less than 90%

Delta: the ratio of peel strength (g/25 mm) at the time of peeling the adhesive sheet from the alkali-free glass plate after removing the surface protective film from the alkali-free glass plate is 70% to less than 80%

X: the ratio of peel strength (g/25 mm) at the time of peeling the adhesive sheet from the alkali-free glass plate after removing the surface protective film from the alkali-free glass plate is less than 70%

[ wettability test ]

Wettability was measured at 25 ℃. Each of the prepared surface protective films was cut into dimensions of 25mm×200mm (width×length). On one edge surface (width: 25mm, length: 5 mm) of the surface protective film, an alkali-free glass plate (EAGLE) was contacted in one directionCorning corporation) to make an angle between the surface of the adhesive layer (see 2 of fig. 1) from which the surface protective film of the release film (see 1 of fig. 1) is removed and the surface of the alkali-free glass plate (3 of fig. 1) in the longitudinal direction of the surface protective film to be 20 ° to 30 °. The surface protective film is then dropped from the hand so as to adhere to the alkali-free glass sheet by the weight of the surface protective film (as indicated by the arrow in fig. 1). Here, the period of time during which the surface of the adhesive layer of the surface protective film was wetted by the alkali-free glass plate and spread on the surface thereof was measured by naked eyes. The wettability of each surface protective film was evaluated according to the following criteria. "DELTA" or higher indicates that the surface protective film has good wettability.

(evaluation criteria)

And (3) the following materials: wetting and spreading times of less than 3 seconds

O: wetting and spreading times of 3 seconds to less than 5 seconds

Delta: wetting and spreading times of 5 seconds to less than 10 seconds

X: wetting and spreading times exceeding 10 seconds

[ transmittance (%) ]

Each of the prepared surface protective films was cut into a size of 25mm×50mm (width×length), and then the release film was removed therefrom. The surface protective film was then pressed against an alkali-free glass plate (EAGLECorning corporation) such that the surface of the adhesive layer of the surface protective film contacts the alkali-free glass plate, thereby preparing a test sample. The transmittance (%) of the test sample was measured using a haze meter (NDH 500W, japan electrochromic co. (Nippon Denshoku Industries co., ltd.)).

[ haze (%) ]

Each of the prepared surface protective films was cut into a size of 25mm×50mm (width×length), and then the release film was removed therefrom. The surface protective film was then pressed against an alkali-free glass plate (EAGLECorning corporation) such that the surface of the adhesive layer of the surface protective film contacts the alkali-free glass plate, thereby preparing a test sample. The haze (%) of the test sample was measured using a haze meter (NDH 500W, japan electrochromic co. (Nippon Denshoku Industries co., ltd.)).

(Table 1 and Table 2) evaluation results of Components of thermosetting adhesive composition and surface protective film thereof

TABLE 1

TABLE 2

TABLE 3

As shown in tables 1 to 3, the surface protective films 13 to 18 have adhesive layers formed of thermosetting adhesive compositions 13 to 18 corresponding to comparative examples, respectively. These thermosetting adhesive compositions contain an excess of (D) component or do not contain (D) component. It can be seen that the surface protective films 13 to 15 and 18 have low press workability, low wettability, and high haze. Further, it can be seen that the surface protective films 16 and 17 have high glass adhesion strength.

The surface protective films 1 to 12 have adhesive layers formed of the thermosetting adhesive compositions 1 to 12 corresponding to the embodiments of the present invention, respectively. It can be seen that these surface protective films 1 to 12 have a high degree of compatibility between adhesion and reworkability. In addition, it can be seen that these surface protective films suppress detachment of the adhesive layer, and have low peeling electrostatic voltage, low substrate contamination, and good wettability. In addition, it can be seen that these surface protective films have high transmittance, low haze, and high transparency.

< evaluation of surface protective film 2>

The surface protective films 19 to 23 were evaluated for glass adhesion strength, glass adhesion strength after ultraviolet light irradiation, press workability, peeling electrostatic voltage, substrate contamination, wettability, transmittance, and haze by the same method and evaluation criteria as those of the evaluation 1. Further, the following evaluations were performed on the surface protective films 1 and 19 to 23. The evaluation results are shown in Table 4.

[ glass adhesion Strength ratio ]

Each of the prepared surface protective films was cut into dimensions of 25mm×200mm (width×length). Then, alkali-free glass was subjected to the same method as that for evaluating the adhesive strength of glassBoard (EAGLE)Corning corporation) presses against the surface of the adhesive layer of the surface protective film from which the release film is removed. Then, the alkali-free glass plate with the surface protective film pressed thereon was left under LED illumination (500 lux) at 23 ℃ x 50% rh for 15 days (360 hours). Thereafter, the peel strength at the time of peeling the surface protective film from the alkali-free glass plate was measured in the same manner as the evaluation of the glass adhesive strength described above, and the measured value was defined as the glass adhesive strength (g/25 mm) after the LED stability test. The value obtained by dividing the glass adhesion strength after the LED stability test by the glass adhesion strength is defined as the glass adhesion strength ratio. The glass adhesion strength ratio of 0.8 to 1.2 was evaluated as good, but is not limited thereto.

[ ratio of glass adhesion Strength after ultraviolet irradiation ]

Each of the prepared surface protective films was cut into dimensions of 25mm×200mm (width×length). Then, by the same method as that for evaluating the adhesive strength of glass, an alkali-free glass plate (EAGLE Corning corporation) presses against the surface of the adhesive layer of the surface protective film from which the release film is removed. Then, the alkali-free glass plate with the surface protective film pressed thereon was left under LED illumination (500 lux) at 23 ℃ x 50% rh for 15 days (360 hours). Then, curing of the adhesive layer was performed by irradiating the surface protective film with ultraviolet light in the same manner as evaluating the adhesive strength of the glass after ultraviolet light irradiation. Thereafter, the glass adhesion strength of the adhesive layer to the glass was measured in the same manner as the evaluation of the glass adhesion strength. The measurement was defined as the glass adhesion strength (g/25 mm) after UV irradiation after LED stability test. The value obtained by dividing the ultraviolet light-irradiated glass bonding strength (g/25 mm) after the LED stability test by the ultraviolet light-irradiated glass bonding strength is defined as the ultraviolet light-irradiated glass bonding strength ratio. The glass adhesion strength ratio after irradiation with ultraviolet light of 1.2 or less was evaluated as good, but is not limited thereto.

TABLE 4

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As shown in table 4, the surface protective films 19 to 23 have adhesive layers formed from the thermosetting adhesive compositions 19 to 23 corresponding to the embodiments of the present invention, respectively. These thermosetting adhesive compositions contain a (G) component. Further, the surface protective films 19 to 23 have better performance in terms of the glass adhesion strength ratio and the glass adhesion strength ratio after ultraviolet light irradiation than the surface protective film 1 containing no stabilizer. As a result, it can be seen that the surface protective films 19 to 23 suppress the photo-curing reaction of the adhesive layer under LED light due to the presence of the (G) component. The results show that the surface protective film according to the invention does not need to be protected from light in storage and thus has further improved storage properties due to the presence of the (G) component.

It will be understood by those skilled in the art that various modifications, changes, alterations, and equivalent embodiments may be made without departing from the spirit and scope of the invention.

Claims

1. An adhesive composition comprising:

(A) The components are as follows: a urethane prepolymer containing at least two hydroxyl groups,

(B) The components are as follows: a multifunctional (meth) acrylate ester, which is a mixture of a (meth) acrylate,

(C) The components are as follows: a cross-linking agent, which is a cross-linking agent,

(D) The components are as follows: the cross-linked particles are formed from a blend of particles,

(E) The components are as follows: a photo radical initiator, and

(F) The components are as follows: an antistatic agent is used to prevent the formation of a reactive polymer,

wherein the (D) component is present in an amount of 0.01 to 10 parts by weight relative to 100 parts by weight of the (A) component,

wherein the (D) component has an average particle diameter of 0.5 μm to 30 μm,

wherein the (D) component comprises 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,

wherein the (B) component is present in an amount of 10 to 150 parts by weight and the (E) component is present in an amount of 0.1 to 10 parts by weight relative to 100 parts by weight of the (A) component, and

Wherein the (C) component comprises an isocyanate group-containing compound, and an equivalent ratio (NCO (total) (mol)/OH (mol)) of the total number of moles of isocyanate groups of the isocyanate group-containing compound to the total number of moles of hydroxyl groups of the (a) component is in the range of 0.2 to 10.

2. The adhesive composition according to claim 1, wherein the adhesive strength of the adhesive composition is reduced by irradiation with light.

3. The adhesive composition according to claim 1, wherein the (B) component has a hydroxyl value of 100 mgkoh/g or less.

4. The adhesive composition of claim 1, wherein the isocyanate group-containing compound comprises a difunctional isocyanate, and an equivalent ratio of the number of moles of isocyanate groups of the difunctional isocyanate to the total number of moles of isocyanate groups of the isocyanate group-containing compound (NCO (difunctional) (mol)/NCO (total) (mol)) is greater than 0 and less than 1.

5. The adhesive composition of claim 1, wherein the (C) component comprises a trifunctional or higher-functional isocyanate.

6. The adhesive composition of claim 1, wherein the (a) component comprises a urethane prepolymer having a polyether backbone and at least two hydroxyl groups.

7. The adhesive composition of claim 6, wherein the urethane prepolymer having a polyether backbone and at least two hydroxyl groups is a urethane prepolymer having a polyether backbone, at least two hydroxyl groups, and (meth) acryloyloxy groups.

8. The adhesive composition according to claim 1, wherein the (F) component is present in an amount of 0.5 to 10 parts by weight relative to 100 parts by weight of the (a) component.

9. The adhesive composition of claim 1, further comprising (G) a component: a stabilizer.

10. The adhesive composition according to claim 9, wherein the (G) component stabilizer is not more than 5 parts by weight relative to 100 parts by weight of the (a) component.

11. A cured product of the adhesive composition according to any one of claims 1 to 10.

12. A surface protective film comprising a resin film and an adhesive layer which is provided on one surface of the resin film and is formed from the cured product according to claim 11.