TWI621676B - Adhesive composition, adhesive layer, optical laminate, and electronic device - Google Patents

Abstract

An adhesive composition includes a main agent. The main agent includes an acrylic copolymer and 2-ethylhexyl acrylate. The acrylic copolymer accounts for 80% to 95% by weight of the main agent. The acrylic copolymer includes at least one selected from the group consisting of ethyl acrylate monomer units, butyl acrylate monomer units, vinyl acetate monomer units, acrylic monomer units, acrylamide monomer units, styrene monomer units, and methyl groups. It consists of methyl acrylate monomer unit, methyl acrylate monomer unit, methacrylic monomer unit, acrylic monomer unit, ethyl methacrylate monomer unit, and hydroxypropyl methacrylate monomer unit. A single unit of a group. 2-ethylhexyl acrylate accounts for 5wt% ~ 20wt% of the main agent.

Description

Adhesive composition, adhesive layer, optical laminate and electronic device

This disclosure relates to an adhesive composition. The disclosure also relates to an adhesive layer formed from the adhesive composition. The disclosure also relates to an optical laminate including the adhesive layer and an electronic device including the adhesive layer.

Various adhesive layers have a wide range of applications, especially they can be used in various functional film layers with adhesive properties, such as polarizers, explosion-proof films, and so on. The adhesive layer can be formed by coating and curing the adhesive composition. If moisture penetrates into the adhesive layer, it may cause peeling, and / or cloud point or a certain range of cloudiness or whitening (hereinafter referred to as whitening phenomenon). Therefore, there is a need for an adhesive layer that can reduce or even eliminate the whitening phenomenon formed by it.

According to some embodiments, there is provided an adhesive composition, which can be used to improve the whitening phenomenon. The adhesive composition includes a main agent. The main agent includes an acrylic copolymer and 2-ethylhexyl acrylate (2-EHA). The acrylic copolymer accounts for 80% to 95% by weight of the main agent. The acrylic copolymer includes at least one selected from the group consisting of ethyl acrylate monomer units, butyl acrylate monomer units, vinyl acetate monomer units, acrylonitrile monomer units, acrylamide monomer units, styrene monomer units, and Methyl acrylate monomer unit, methyl acrylate monomer unit, methacrylic monomer A monomer unit of the group consisting of a unit, an acrylic monomer unit, an ethyl methacrylate monomer unit, and a hydroxypropyl methacrylate monomer unit. 2-ethylhexyl acrylate accounts for 5wt% ~ 20wt% of the main agent.

According to some embodiments, there is provided an adhesive layer formed by coating and curing, for example, the above-mentioned adhesive composition.

According to some embodiments, an optical laminate is provided herein. The optical laminate includes, for example, the above-mentioned adhesive layer. The optical laminate also includes a base layer as an optical layer. The adhesive layer is disposed on the base layer.

According to some embodiments, an electronic device is provided herein. The electronic device includes, for example, the above-mentioned adhesive layer.

100‧‧‧ Adhesive layer

102‧‧‧Release film

200‧‧‧ Grassroots

300‧‧‧ flat display module

310‧‧‧ Upper Polarizer

350‧‧‧Touch Module

360‧‧‧Frame glue

370‧‧‧air layer

In order to have a better understanding of the above and other aspects of the present invention, preferred embodiments are described below in detail with the accompanying drawings, as follows: Figure 1 is a schematic diagram of an optical laminate according to the embodiment.

FIG. 2 is a schematic diagram of an electronic device according to an embodiment.

When the adhesive composition is an optical clear adhesive, that is, when the adhesive layer is used in a functional film layer that requires optical transparency, the whitening phenomenon may affect the visual effect. Poor adhesion of the adhesive layer will cause water vapor to penetrate and whitening. On the other hand, if the adhesive layer itself provides good adhesion and protection characteristics, but the components to which the adhesive layer is bonded have high moisture permeability, it may be difficult to discharge due to water vapor infiltration and whitening may also occur.

One aspect of this disclosure is related to adhesive compositions. The embodiment adjusts the composition of the adhesive composition, which can reduce or even eliminate the whitening phenomenon of the adhesive layer formed by it. According to some embodiments, the adhesive composition includes a base agent. The main agent includes an acrylic copolymer and 2 ~ ethylhexyl acrylate (2 ~ EHA). The acrylic copolymer accounts for 80% to 95% by weight of the main agent. 2-ethylhexyl acrylate accounts for 5wt% ~ 20wt% of the main agent. Here, the acrylic copolymer does not include a 2-ethylhexyl acrylate monomer unit. That is, 2-ethylhexyl acrylate is not used as a monomer for forming an acrylic copolymer.

The acrylic copolymer includes at least one selected from the group consisting of ethyl acrylate monomer units, butyl acrylate monomer units, vinyl acetate monomer units, acrylonitrile monomer units, acrylamide monomer units, styrene monomer units, Methyl methacrylate monomer unit, methyl acrylate monomer unit, methacrylic monomer unit, acrylic monomer unit, ethyl methacrylate monomer unit, and hydroxypropyl methacrylate monomer unit Group of monomer units. That is, the acrylic copolymer may be selected from the group consisting of ethyl acrylate, butyl acrylate, vinyl acetate, acrylonitrile, acrylamide, styrene, methyl methacrylate, methyl acrylate, methacrylic acid, acrylic acid, and formic acid. A group of two or more monomers composed of ethyl propylene hydroxyacrylate and hydroxypropyl methacrylate, or one or more monomers selected from this group and other suitable monomers ( Excluding 2-ethylhexyl acrylate) polymerization. By way of example, the acrylic copolymer can be obtained by copolymerizing acrylic acid, butyl acrylate, and vinyl acetate.

According to some embodiments, the adhesive composition may further include a cross-linking hardener. For example, polyisocyanate can be used as a cross-linking hardener, which has excellent solubility in organic solvents and contains highly polar N-HCO-groups that can wet the adherends or form strong hydrogen bonds and dipole attractive forces. . In some embodiments, relative to 100 The weight of the main agent, the polyisocyanate is 0.01 to 0.1 parts by weight.

According to some embodiments, the adhesive composition may further include other hardeners. According to some embodiments, in particular, a metal chelate-based hardener can be used, which has the advantages of fast hardening speed, bridging effect immediately after drying, small performance deviation, non-yellowing, and the like. In some embodiments, the metal chelate-based hardener is 0.4 to 0.5 parts by weight relative to 100 parts by weight of the main agent. According to some embodiments, the metal chelate-based hardener may be, but is not limited to, an acetate, caprylate, naphthenate, or organic acid salt of a metal such as zinc, cadmium, cobalt, or lead.

According to some embodiments, the adhesive composition may further include other additives. According to some embodiments, in particular, organosilicon compounds having a special structure may be used. For example, a silane coupling agent can be used as one of the additives, which has a unique bifunctionality, which can promote the combination of organic polymers and the surface of inorganic minerals, so that the composite material retains its strength (adhesion) under long-term use. In some embodiments, the silane coupling agent is less than or equal to 0.2 parts by weight relative to 100 parts by weight of the main agent.

In some embodiments, the adhesive composition preferably has a glass transition temperature (Tg) falling within a range of -50 ° C to -40 ° C. When the glass transition temperature is too high, the adhesive layer formed by the adhesive composition may be too hard, resulting in poor characteristics and reliability. When the glass transition temperature is too low, the adhesive layer formed by the adhesive composition may be soft and not conducive to processing. The glass transition temperature more preferably falls within a range of -48 ° C to -43 ° C. The glass transition temperature of the adhesive composition can be different by using monomers having different glass transition temperatures and / or adjusting the proportion of the monomers.

The adhesive composition according to the embodiment may be, but is not limited to, optical gum. Optical adhesives have a variety of applications. For example, various optical film layers, such as polarizers, can be attached to liquid crystal displays, touch panels, or other portable electronic devices. In order not to affect the visual effect, the adhesive composition as an optical adhesive must have appropriate optical properties such as light transmittance and refractive index. In addition, there must be a certain degree of tolerance for various environments that electronic devices such as displays may experience during manufacturing, storage, and use, including high temperature and / or high humidity environments (such as in accelerated aging tests). The adhesive composition according to the embodiment can provide the above-mentioned characteristics.

The adhesive composition according to the embodiment of the present disclosure uses the acrylic copolymer as a main component as described above, and since there are no unsaturated bonds, it has good long-term resistance to environmental impact, that is, good durability, and It also has good optical characteristics. The adhesive composition according to the embodiment of the present disclosure also includes a smaller amount of a soft monomer having a hydrophilic functional group, that is, 2-ethylhexyl acrylate, which is generally used to improve the haze caused by the infiltration of water vapor. . Compared with the general addition of a large amount of 2-ethylhexyl acrylate soft monomer (such as 80% to 95% or even more), the cohesive force of the adhesive composition is reduced, the adhesive force is increased, and the post-adhesion peeling is reduced. For the optical adhesive, the content of 2-ethylhexyl acrylate in the adhesive composition according to the embodiment of the present disclosure is greatly reduced. Even so, by adjusting the components of the adhesive composition and using the acrylic copolymer as described above, the adhesive composition according to the embodiment can have excellent adhesive properties.

In addition, compared with general optical glue, the adhesive composition according to the embodiment is preferably suitable for bonding a component having high moisture permeability, for example, a base layer composed of a cellulose-based resin. The cellulose-based resin refers to cellulose Part of the resin is hydroxyl esterified by acetic acid, or mixed esters partially acetated and others acidified. The cellulose-based resin is preferably a cellulose ester-based resin, and more preferably an ethyl acetate-based fiber. Vitamin resins, such as triethyl cellulose, diethyl cellulose, cellulose acetate propionate, cellulose acetate butyrate, etc., cellulose fully esterified is called triacetate fiber But not limited to triacetate cellulose (TAC).

The adhesive composition according to the embodiment is suitable for other optical base layers. Specific materials of these optical base layers are, for example, cellulose resin, acrylic resin, amorphous polyolefin resin, polyester resin, polycarbonate. Series resins and combinations thereof may specifically include polymethylmethacrylate (PMMA), cellulose resins refer to resins in which some of the hydroxyl groups in cellulose are esterified with acetate, Some are mixed esters esterified by others. The cellulose resin is preferably a cellulose ester resin, more preferably an ethyl cellulose resin, such as triethyl cellulose, diethyl cellulose, cellulose acetate propionate, cellulose Acetate butyrate, cellulose triacetate, acrylic resin film, polyaromatic hydroxy resin film, polyether resin film, cyclic polyolefin resin film (such as polybornene resin film), and polycarbonate-based resins such as Polyesters formed from diols or bisphenols, such as: Polyethylene Terephthalate (PET), Polypropylene (PP), Polyethylene (PE), Amorphous Polyolefin Series resins such as cyclic olefin (co) polymers (COC / COP), developed from norbornene, cyclopentadiene, dicyclopentadiene, tetracyclododecene, etc. A family of cyclic polymers or copolymers with olefins, polycarbonate (PC), and any combination of the above.

In addition, the adhesive composition according to the embodiment has strong initial adhesion and maintains softness in a low-temperature environment, and can also provide smooth application characteristics at step differences.

Another aspect of this disclosure relates to an adhesive layer. The adhesive layer may be formed of the adhesive composition according to any one of the above embodiments. For example, the adhesive layer may be formed by curing and curing the adhesive composition according to any one of the above-mentioned embodiments after coating and heat curing. The acrylic copolymer and 2-ethylhexyl acrylate react through a curing step. In this case, for example, the unsaturated bonds contained in the two are opened and connected to each other. In addition, acrylate pressure-sensitive adhesives are mainly prepared from monomers with unsaturated double bonds and subjected to radical addition polymerization under the action of an initiator to obtain an acrylate copolymer. The initiator refers to Peroxide, a copolymer of acrylic acid, butyl acrylate, and vinyl acetate is polymerized after the initiator is added, and then an acrylic acid copolymer is formed. The adhesive layer has double-sided adhesiveness.

Another aspect of the present disclosure relates to optical laminates, such as, but not limited to, explosion-proof films. Please refer to FIG. 1, which illustrates an optical laminate according to an embodiment. The optical laminate may include an optical layer and an adhesive layer 100. For example, the base layer 200 may be used as the optical layer, which is particularly suitable for a case where the optical laminate is an explosion-proof film. In some embodiments, the base layer 200 is a cellulose triacetate film. The adhesive layer 100 may be an adhesive layer according to the aforementioned embodiment. The adhesive layer 100 is, for example, disposed on the base layer 200. According to some embodiments, the optical laminate may further include one or more other film layers. In some embodiments, the optical laminate further includes a release film 102. The release film 102 may be disposed on the adhesive layer 100. That is, in some embodiments, two opposite sides of the adhesive layer 100 may contact the optical layer (base layer 200) and the release film 102, respectively.

Another aspect of this disclosure relates to electronic devices, such as but not limited to touch display devices. Please refer to FIG. 2, which illustrates an electronic device according to an embodiment. The electronic device includes an adhesive layer according to the aforementioned embodiment. In some In an embodiment, the electronic device is an electronic device to which the aforementioned optical laminate is applied. That is, the electronic device includes an adhesive layer 100. In addition, the electronic device also includes the optical layer as described above, such as the base layer 200, located on one side of the adhesive layer 100. For example, the aforementioned optical laminate may be attached to the touch module 350 after the release film 102 is removed, and then bonded to the flat display module 300. In the example of FIG. 2, the flat display module 300 is provided with an upper polarizing plate 310, and the upper polarizing plate 310 is bonded to the base layer 200 as an optical layer by, for example, a frame adhesive 360. The sealant 360 may form an air layer 370 between the upper polarizing plate 310 and the base layer 200.

Hereinafter, the present disclosure will provide several examples and comparative examples to more specifically explain the effect that the adhesive composition according to the embodiment of the present disclosure and the adhesive layer formed therefrom can achieve.

[Example 1]

80% by weight of a copolymer of acrylic acid, butyl acrylate, and vinyl acetate, and 20% by weight of 2-ethylhexyl acrylate were used as main agents. Next, a cross-linking hardener is added. Here, an isocyanate alkyl compound (trimethylol propane toluene diidocyanate, synthesized by Japan PU, N-75, 75% solid content) dissolved in toluene as a solvent is used, which has the following chemical formula 1 structure. The alkyl isocyanate compound is 0.1 part by weight based on 100 parts by weight of the main agent. Then, a metal chelate-based hardener is added, and a compound chelated by aluminum metal with acetone or acetone ethyl acetate (Shinjo Industries, M-5) is used. It has a structure as shown in the following Chemical Formula 2. The metal chelate compound is 0.5 part by weight with respect to 100 parts by weight of the main agent. Then, a silane coupling agent is added, and gamma-glycidoxypropyl trimethoxy silane (Shin-Etsu Chemical Co., Ltd., KBM-403) is used, which has a structure as shown in Chemical Formula 3 below. Relative to 100 weight The main component and the silane coupling agent were 0.2 parts by weight. Stir for 30 minutes. The semi-finished product fluid was applied on a N850 H850 release film in a quantitative manner using a doctor blade. Drying and curing in an oven at 100 ° C for 3 minutes. Then attach another layer of South Asia L138B release film on the laminator.

[Example 2]

The content of the copolymer of acrylic acid, butyl acrylate and vinyl acetate was adjusted to 95% by weight of the main agent, and the content of 2-ethylhexyl acrylate was adjusted to main content 5wt% of the agent. Other conditions are as in Example 1. Samples were made according to the method described in Example 1.

[Example 3]

The addition amount of the alkyl isocyanate compound was adjusted to 0.01 part by weight based on 100 parts by weight of the main agent. Other conditions are as in Example 1. Samples were made according to the method described in Example 1.

[Example 4]

The content of the copolymer of acrylic acid, butyl acrylate, and vinyl acetate was adjusted to 95% by weight of the main agent, and the content of 2-ethylhexyl acrylate was adjusted to 5% by weight of the main agent. The addition amount of the alkyl isocyanate compound was adjusted to 0.01 part by weight based on 100 parts by weight of the main agent. Other conditions are as in Example 1. Samples were made according to the method described in Example 1.

[Comparative Example 1]

The content of the copolymer of acrylic acid, butyl acrylate, and vinyl acetate was adjusted to 75% by weight of the main agent, and the content of 2-ethylhexyl acrylate was adjusted to 25% by weight of the main agent. Other conditions are as in Example 1. Samples were made according to the method described in Example 1.

[Comparative Example 2]

The content of the copolymer of acrylic acid, butyl acrylate, and vinyl acetate was adjusted to 100% by weight of the main agent. Other conditions are as in Example 1. Samples were made according to the method described in Example 1.

[Comparative Example 3]

No alkyl isocyanate compound was added. Other conditions are as in Example 1. Samples were made according to the method described in Example 1.

[Comparative Example 4]

No metal chelate is added. Other conditions are as in Example 1. Samples were made according to the method described in Example 1.

[Comparative Example 5]

No silane coupling agent is added. Other conditions are as in Example 1. Samples were made according to the method described in Example 1.

[Comparative Example 6]

A sample prepared according to the method described in Example 1 but with a glass transition temperature of -55 ° C was used.

[Comparative Example 7]

A sample prepared according to the method described in Example 1 but with a glass transition temperature of -35 ° C was used.

[Glass transition temperature test]

Take 3 milligrams (mg) to 10 milligrams of each of the examples and comparative examples that do not include a release film (hereinafter referred to as an adhesive layer sample, for example, a sample after the release film is removed), and sealed in a DSC tester (Perkin Elmer, DSC 6000) aluminum carrier. The operating conditions were first heating to 250 ° C at a heating rate of 20 ° C / min, then lowering the temperature to -75 ° C, and then heating again to 250 ° C at the same heating rate, and recording the results of the two-stage heating experiments.

[Coatability test]

For each of the examples and comparative examples, after the N138 L138B release film was pasted, observe whether there is any abnormality on the film surface and confirm whether it is measured by measuring the thickness change. The coating film may be uneven. The test results are listed in Table 1. "◎" indicates that the test results are acceptable, that is, there are no bubbles and no uneven coating.

[Initial retention test]

In accordance with JIS Z2037, steel plates of type 302 or 304 stainless steel, size 50 mm (mm) * 75 mm * 1.6 mm, and surface roughness (Ra) 0.050 ± 0.025 micrometer (μm) are used. Its central hole penetrates to facilitate hooking. The steel sheet was wiped with ethyl acetate (EAC) solvent and left for 5 minutes. The adhesive layer sample was attached to a polyethylene terephthalate (PET) film with a thickness of 25 micrometers, and a test piece of 25.4 mm * 180 mm was cut. The test piece was vertically attached to the center of the steel plate, and then rolled back and forth once at a speed of about 300 mm / min using a 2 kg rolling roller. The effective area of the test piece is 25mm * 25mm. After leaving the longer part at the bottom, it is folded back to catch the iron bell of 1kg. It was then hung in a constant temperature oven set at 8 ° C until it fell off the steel sheet, and the time was measured. The test results are listed in Table 1. Passing times exceeding 10,000 minutes were considered acceptable.

[Initial adhesion test]

According to JIS Z2037, the adhesive layer sample with a fixed width of 25 mm was attached to a PET film with a thickness of 100 μm and rolled back and forth twice with a 2 kg roller to make the adhesive layer sample and the adhered PET The film was closely adhered to make a test piece. Then, a pressure defoaming process is performed, in which the temperature is set to 50 ° C. and the pressure is 0.5 MPa. After 20 minutes, the test piece was allowed to stand for 24 hours in an environment of a temperature of 23 ° C and a humidity of 65%. Next, the adhesive force of the adhesive layer sample with a width of 25 mm was measured with a universal tensile machine (Shimadzu Corporation), wherein the tensile speed was set to 300 mm / min and the tensile angle was 180 degrees. The test results are listed in Table 1. The results are greater than 15N / 25mm is qualified.

[High temperature and high humidity adhesion test]

According to JIS Z2037, the adhesive layer sample with a fixed width of 25 mm was attached to a PET film with a thickness of 100 μm and rolled back and forth twice with a 2 kg roller to make the adhesive layer sample and the adhered PET The film was closely adhered to make a test piece. Then, a pressure defoaming process is performed, in which the temperature is set to 50 ° C. and the pressure is 0.5 MPa. After 20 minutes, the test piece was placed in an oven set to an environment of a temperature of 60 ° C and a humidity of 90% for 24 hours. Take out immediately and then measure the adhesive force of the adhesive layer sample with a width of 25 mm with a universal tensile machine (Shimadzu Corporation), where the stretching speed is set to 300 mm / min and the stretching angle is 180 degrees. The test results are listed in Table 1. If the result is more than 20N / 25mm, it is qualified.

[Reliability Test]

The adhesive layer samples of each example and comparative example were bonded between a cellulose triacetate film and glass, degassed under pressure to make a test piece, and then tested for reliability under two conditions. One of the conditions is that the oven (Espec) is set to an environment with a temperature of 60 ° C and a humidity of 95%, and the test piece is placed in the oven and tested for 500 hours. Another condition is that the oven (Espec) is set to an environment with a temperature of 90 ° C, and the test piece is placed in the oven and tested for 500 hours. Thereafter, the total light transmittance (Tt) and haze (Haze) were measured with a haze meter (NIPPON DENSHOKU INDUSTRIES CO., LTD). The test results are listed in Table 1. The total light transmittance is more than 99% to be qualified, which is indicated by "◎". Haze is acceptable if it is less than or equal to 0.5%. In addition, observe the foamability. The test results are listed in Table 1. "◎" indicates no foaming, and "○" indicates slight foaming, that is, it is difficult to identify visually. It needs to be observed with an optical microscope and occurs. At the edges and corners, "Δ" indicates partial foaming, which can be identified visually, but only occurs in specific areas and the foaming is not dense. "╳" indicates severe foaming, that is, the area where foaming occurs is comprehensive. And foaming is dense. And observe the peelability, the test results are listed in Table 1. "◎" means no peeling, "○" means slight peeling, that is, peeling occurs within a range of less than 1 mm from the edge of the film, and "Δ" means partial peeling That is, peeling occurs within a range of 1 mm to 5 mm from the edge of the film. "╳" indicates severe peeling, that is, peeling occurs within a range of 5 mm from the edge of the film.

[Results and evaluations]

The components and test results of the examples and comparative examples are shown in Table 1. It can be seen that the adhesive composition of the present disclosure and the adhesive layer formed by the adhesive composition obtained good results in various test items. Specifically, in the adhesive composition and the adhesive layer formed by the adhesive composition of all the examples in the disclosure, no air bubbles and uneven coating were observed in the coating test results, and the initial retention test results exceeded 10,000 minutes, the initial adhesion test results are greater than 15N / 25mm, the high temperature and high humidity adhesion test results are greater than 20N / 25mm, 60 ℃, 95% humidity, 500 hours of reliability test results are full light transmittance All are greater than 99%, haze is less than or equal to 0.5%, no foaming, no peeling, and the results of the reliability test at 90 ° C for 500 hours are that all light transmittances are greater than 99% and haze is less than or equal to 0.5%, no foaming, no peeling.

In summary, although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field to which the present invention pertains can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope of the attached patent application.

Claims (13)

An adhesive composition includes: a main agent, including: an acrylic copolymer, which accounts for 80% to 95% by weight of the main agent. The acrylic copolymer includes at least one selected from ethyl acrylate monomer units and butyl acrylate monomer units. Body unit, vinyl acetate monomer unit, acryl monomer unit, acrylamide monomer unit, styrene monomer unit, methyl methacrylate monomer unit, methyl acrylate monomer unit, methacrylic monomer unit , Acrylic monomer units, ethyl methacrylate monomer units, and hydroxypropyl methacrylate monomer units; and 2-ethylhexyl acrylate, which is the main agent 5 wt% to 20 wt%; and a polyisocyanate as a cross-linking hardener, wherein the polyisocyanate is 0.01 to 0.1 parts by weight relative to 100 parts by weight of the main agent. The adhesive composition according to item 1 of the application, wherein the acrylic copolymer is made by copolymerizing acrylic acid, butyl acrylate, and vinyl acetate. The adhesive composition according to item 1 of the patent application scope further includes a metal chelate hardener, wherein the metal chelate hardener is 0.4 to 0.5 parts by weight relative to 100 parts by weight of the main agent. The adhesive composition according to item 3 of the scope of patent application, wherein the metal chelate hardener is zinc, cadmium, cobalt, or lead acetate, caprylate, naphthenate, or laurate. The adhesive composition according to item 1 of the patent application scope further includes a silane coupling agent as an additive, wherein the silane coupling agent is less than or equal to 0.2 parts by weight with respect to 100 parts by weight of the main agent. The adhesive composition according to item 1 of the patent application scope has a glass transition temperature falling within a range of -50 ° C to -40 ° C. An adhesive layer is formed by coating and curing the adhesive composition according to any one of claims 1 to 6 of the scope of patent application. An optical laminate includes: a base layer as an optical layer; and an adhesive layer as described in item 7 of the scope of patent application, which is disposed on the base layer. The optical laminate as described in item 8 of the scope of patent application, further comprising: a release film disposed on the adhesive layer. The optical laminate described in item 8 of the scope of patent application is an explosion-proof film. An electronic device includes an adhesive layer as described in item 7 of the scope of patent application. The electronic device according to item 11 of the scope of patent application, further includes: a base layer as an optical layer, which is located on one side of the adhesive layer. The electronic device described in item 11 of the scope of patent application is a touch display device.