KR102119901B1 - Photocurable adhesive composition, method for the same and adhesive film - Google Patents

Abstract

(Meth)acrylic polymer in which a (meth)acrylic monomer component including a first monomer having a glass transition temperature of -70°C to -20°C and a second monomer having a glass transition temperature of 10°C to 110°C is polymerized; (Meth)acrylic monomers; And it provides a photo-curable pressure-sensitive adhesive composition comprising a photoinitiator, a method of manufacturing the same, and an adhesive film.

Description

Photocurable adhesive composition, manufacturing method thereof, and adhesive film {PHOTOCURABLE ADHESIVE COMPOSITION, METHOD FOR THE SAME AND ADHESIVE FILM}

It relates to a photocurable adhesive composition, a method for manufacturing the same, and an adhesive film.

Demand for an image display device that inputs, manipulates, and displays information on a touch screen, such as a television, computer, mobile communication terminal, car navigation system, and cash machine, is increasing.

Such an image display device includes a protective part such as a glass substrate or a transparent plastic substrate on an image display part such as, for example, a liquid crystal display (LCD), and further includes an adhesive film or an adhesive tape to fix them. Doing.

In addition, the edge area of the image display device may refer to an area from a portion where the display of an image, an image, etc. does not appear because light is not transmitted, to an end portion of the main body of the image display device. It may also be referred to as a bezel area, and in the bezel area, the image display unit and the protection unit of the image display device may be adhered via an adhesive film or adhesive tape.

In general, the above-described adhesive film or adhesive tape may be formed of an acrylic composition.

In one embodiment of the present invention, there is provided a photocurable adhesive composition capable of realizing a high level of impact resistance, repulsion resistance and high temperature retention.

In another embodiment of the present invention, it provides an adhesive film capable of realizing a high level of impact resistance, repulsion resistance and high temperature retention.

In another embodiment of the present invention, a method for gradually preparing the photocurable composition is provided.

However, the technical problem to be achieved by the present invention is not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by a person skilled in the art from the following description.

In one embodiment of the present invention, a (meth)acrylic monomer component comprising a first monomer having a glass transition temperature of -70°C to -20°C and a second monomer having a glass transition temperature of 10°C to 110°C is polymerized ( Meth)acrylic polymers; (Meth)acrylic monomers; And it provides a photocurable adhesive composition comprising a photoinitiator.

The photocurable pressure-sensitive adhesive composition may be a (meth)acrylic syrup formed by performing bulk polymerization by irradiation of light with respect to a polymerization composition comprising a (meth)acrylic monomer component comprising the first monomer and the second monomer. .

As described above, the photocurable pressure-sensitive adhesive composition may be formed by a bulk photopolymerization reaction in which a polymerization reaction is initiated by irradiation of light, thereby realizing superior high temperature properties. In addition, since it does not contain an organic solvent, it is possible to achieve excellent eco-friendliness and high yield compared to solution polymerization containing a solvent or emulsion polymerization requiring a large amount of additives. In addition, the photocurable pressure-sensitive adhesive composition can completely stop the polymerization reaction at room temperature by blocking light, and since the polymerization reaction does not proceed according to the temperature change, compared to the bulk thermal polymerization reaction in which the polymerization reaction is initiated by heat treatment. Excellent storage stability.

In one embodiment, as the first monomer, n-butyl acrylate may not be included, and accordingly, odor generated during operation may be removed, thereby providing superior workability.

The weight ratio of the first monomer to the second monomer among all monomer components forming the (meth)acrylic polymer may be about 1:0.3 to about 1:1. By having a weight ratio within the above range, physical properties such as the glass transition temperature of the (meth)acrylic polymer can be appropriately adjusted to effectively improve high temperature properties.

In another embodiment of the present invention, an adhesive film including a photocured product of the photocurable adhesive composition is provided.

The adhesive pilung may have an impact strength of about 500 mJ to about 1,000 mJ. By having an impact strength within the above range, it is possible to effectively absorb external shocks to realize excellent impact resistance, and is used for fixing a window panel of a mobile device, such as a mobile phone, for example, such as damage or dropout. It is possible to effectively prevent damage to the device or performance degradation.

In another embodiment of the present invention, a (meth)acrylic monomer component comprising a first monomer having a glass transition temperature of -70°C to -20°C and a second monomer having a glass transition temperature of 10°C to 110°C is included. Preparing a composition for polymerization; And preparing a photocurable adhesive composition by performing bulk polymerization by irradiating light with a light amount of about 100 mJ/cm ² to about 1,000 mJ/cm ² for about 1 minute to about 10 minutes with respect to the polymerization composition. It provides a method for producing a photocurable adhesive composition containing.

The photo-curable pressure-sensitive adhesive composition and the pressure-sensitive adhesive film may be implemented with excellent levels of impact resistance, rebound resistance, and high temperature retention.

Hereinafter, embodiments of the present invention will be described in detail. However, this is provided as an example, and the present invention is not limited thereby, and the present invention is only defined by the scope of claims to be described later.

In one embodiment of the present invention, a (meth)acrylic monomer component comprising a first monomer having a glass transition temperature of -70°C to -20°C and a second monomer having a glass transition temperature of 10°C to 110°C is polymerized ( Meth)acrylic polymers; (Meth)acrylic monomers; And it provides a photocurable adhesive composition comprising a photoinitiator. In general, in the case of an adhesive tape applied to an image display device such as a mobile device, high temperature properties such as impact resistance to external impact, repulsion resistance, and high temperature holding power are considered important.

Thus, the photocurable pressure-sensitive adhesive composition is formed by performing bulk polymerization by irradiation of light with respect to a polymerization composition containing a heterogeneous monomer having a different glass transition temperature, as will be described later, thereby providing impact resistance, rebound resistance, and high temperature retention. This can be effectively improved.

The photocurable pressure-sensitive adhesive composition may be a (meth)acrylic syrup formed by performing bulk polymerization by irradiation of light with respect to a polymerization composition comprising a (meth)acrylic monomer component comprising the first monomer and the second monomer. .

Accordingly, the photocurable adhesive composition may not include an organic solvent. Such organic solvents include, for example, at least one selected from the group consisting of diethyl ether, tetrahydrofuran, dichloromethane, chloromethane, xylene, dimethylformamide, cyclohexane, hexane, chloroform, and combinations thereof. It may include, but is not limited to, it is meant to include all kinds known in the art.

As described above, the photocurable pressure-sensitive adhesive composition may be formed by a bulk photopolymerization reaction in which a polymerization reaction is initiated by irradiation of light, thereby realizing superior high temperature properties.

In addition, since it does not contain an organic solvent, it is possible to achieve excellent eco-friendliness and high yield compared to solution polymerization containing a solvent or emulsion polymerization requiring a large amount of additives.

In addition, the photocurable pressure-sensitive adhesive composition can completely stop the polymerization reaction at room temperature by blocking light, and since the polymerization reaction does not proceed according to the temperature change, compared to the bulk thermal polymerization reaction in which the polymerization reaction is initiated by heat treatment. Excellent storage stability.

The composition for polymerization may include the total of the (meth)acrylic monomer component at about 90% by weight to about 99.5% by weight.

The polymerization composition may further include a polymerization initiator, and may further include a photoinitiator as the polymerization initiator.

The photoinitiators include, for example, Benzoin Ethers, Benzyl Dialkyl Ketals, Benzophenone, Acetophenone, TPO (2,4,6-Trimethylbenzoyl diphenylphosphineoxide) and these It may include at least one selected from the group containing a combination of, but is not limited thereto.

The composition for polymerization may include one selected from the group consisting of a monomer having a hydroxy group, a monomer having a carboxyl group, a monomer having a nitrogen-containing functional group, and combinations thereof.

The monomer having the hydroxy group is hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 10- Hydroxydecyl (meth)acrylate and the like, and the monomer having the carboxyl group is acrylic acid, methacrylic acid, crotonic acid, maleic acid, maleic anhydride, itaconic acid, fumaric acid, glycolic acid, cinnamic acid, acrylic acid dimer, methacrylic acid dimer , Acrylic acid trimer, acrylic acid tetramer, methacrylic acid tetramer, and the like, and the monomer having a nitrogen-containing functional group is N-vinylpinidylone, N-vinyl caprolactam, acryloyl morpholine, acrylonitrile, acrylic Amide, N,N-dimethylacrylamide, and the like, but is not limited thereto.

The photocurable adhesive composition may be the (meth)acrylic syrup formed by the bulk polymerization as described above, and accordingly, the first monomer and glass transition temperature of glass transition temperature of -70°C to -20°C are 10 It may include a (meth) acrylic polymer polymerized with a (meth) acrylic monomer component containing a second monomer of ℃ to 110 ℃.

The photocurable pressure-sensitive adhesive composition may include the (meth)acrylic polymer at about 10% by weight to about 40% by weight.

The first monomer is, for example, n-propyl acrylate, n-tetradecyl acrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, iso It may include at least one selected from the group consisting of propyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, lauryl acrylate, lauryl methacrylate and combinations thereof. Specifically, the first monomer may be 2-ethylhexyl acrylate (EHA), and accordingly, the initial adhesion may be further improved, and excellent economic efficiency may be realized.

In one embodiment, as the first monomer, n-butyl acrylate may not be included, and accordingly, odor generated during operation may be removed, thereby providing superior workability.

The second monomer may include, for example, at least one selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, isobornyl acrylate (IBOA), acrylic acid, and combinations thereof.

The weight ratio of the first monomer to the second monomer among all monomer components forming the (meth)acrylic polymer may be about 1:0.3 to about 1:1. By having a weight ratio within the above range, physical properties such as the glass transition temperature of the (meth)acrylic polymer can be appropriately adjusted to effectively improve high temperature properties.

The (meth)acrylic polymer may have a glass transition temperature of about -60°C to about -10°C. By having a glass transition temperature within the above range, impact resistance, rebound resistance, and high temperature holding power can be effectively improved. Specifically, when the glass transition temperature is less than about -60°C, the high-temperature holding power is lowered, and when it is greater than about -10°C, there is a problem that the wettability to the substrate is lowered and the repellency is lowered.

The (meth) acrylic polymer may have a weight average molecular weight of about 500,000 g/mol to about 3,000,000 g/mol. By having a weight average molecular weight within the above range, resistance to impact from the outside can be improved even under high temperature conditions.

The photocurable composition is a component separate from the (meth)acrylic polymer, and may include the (meth)acrylic monomer, wherein the (meth)acrylic monomer is formed by performing the bulk polymerization of the polymerization composition. It may be an unreacted monomer present in the methacrylic syrup. Accordingly, the (meth)acrylic monomer may include the first monomer and the second monomer.

The photocurable pressure-sensitive adhesive composition may include the total of the (meth)acrylic monomers from about 55% to about 89% by weight.

The (meth)acrylic syrup may have a polymerization conversion rate of about 5% to about 30%. The polymerization conversion rate may mean a polymerization conversion rate of a monomer component included in the polymerization composition to a (meth)acrylic polymer.

Objects and uses of the curing process for curing the adhesive composition while having excellent polymerization and high temperature properties when curing the adhesive composition by appropriately forming the (meth)acrylic polymer by having a polymerization conversion rate within the above range Depending on the range, it can be adjusted in a wide range to give more various properties.

The photocurable pressure-sensitive adhesive composition may include the photoinitiator, and the type of the photoinitiator is as described above in the photoinitiator included in the polymerization composition.

The photoinitiator may include from about 0.1 parts by weight to about 0.5 parts by weight based on 100 parts by weight of the (meth)acrylic polymer. By including the content within the above range, while sufficiently progressing the photocuring reaction, the unreacted photoinitiator remaining in the adhesive composition can be removed or minimized to effectively prevent physical property degradation due to migration.

The photo-curable adhesive composition may further include, for example, one or more additives selected from the group consisting of a crosslinking agent, an ultraviolet stabilizer, an antioxidant, and combinations thereof, but is not limited thereto.

The photo-curable adhesive composition may have a viscosity of about 2,000 cps to about 10,000 cps at about 20°C. By having a viscosity within the above range, each component can be more uniformly mixed, but can be more easily processed into, for example, a film, tape, coating, or the like.

The adhesive film or double-sided adhesive tape made from the photocurable adhesive composition can be used to fix the touch screen panel to the top of the display element panel, or to fix the display element panel to the top of the optical member, for example, for optical , Specifically, it may be suitable for the use of the adhesive composition for a touch screen panel.

In another embodiment of the present invention, an adhesive film including a photocured product of the photocurable adhesive composition is provided. The photo-curable adhesive composition is as described above in one embodiment.

The photocured product may be formed by performing a photocuring reaction on the adhesive composition. The photocuring may be performed by irradiating light for about 1 minute to about 10 minutes at a light amount of about 100 mJ/cm ² to about 1,000 mJ/cm ² , for example, but is not limited thereto.

The thickness of the adhesive film may be about 10㎛ to about 200㎛.

The photocured product may have a curing degree according to the following Equation 1, for example, about 50% to about 80%:

[Calculation formula 1]

Curing degree (%) = W _f /W _i ⅹ 100

In the calculation formula 1, W _i means the weight before dipping the cured sample to a predetermined size and dipping it in the solvent of the obtained specimen, and W _f is immersing the specimen in the solvent and allowed to stand for a period of time, and then using a strainer. It means the weight of the specimen left after filtering.

The type of the solvent and the period during which the specimen is immersed in the solvent may be changed depending on the cured product to be measured.

The solvent may be measured by determining an appropriate reference solvent, and for example, toluene may be used, but is not limited thereto. The time to soak the specimen in a solvent can be appropriately selected, for example, about 24 hours, but is not limited thereto.

By having a degree of curing within the above range, it is possible to realize excellent adhesion and excellent high temperature properties.

The adhesive pilung may have an impact strength of about 500 mJ to about 1,000 mJ. By having an impact strength within the above range, it is possible to effectively absorb external shocks to realize excellent impact resistance, and is used for fixing a window panel of a mobile device, such as a mobile phone, for example, such as damage or dropout. It is possible to effectively prevent damage to the device or performance degradation.

The adhesive film may have an adhesive strength of about 2,000 g/in to about 3,000 g/in. By having an adhesive force within the above range, it is possible to more stably fix certain parts attached through this.

As described above, the adhesive film can realize high temperature properties such as impact resistance, repulsion resistance, and high temperature retention, so that the touch screen panel is fixed to the top of the display element panel, or the display element panel is mounted to the top of the optical member, etc. It can be easily used to fix the, for example, it may be suitable for use in optical, specifically, the use of an adhesive film for a touch screen panel.

In another embodiment of the present invention, a (meth)acrylic monomer component comprising a first monomer having a glass transition temperature of -70°C to -20°C and a second monomer having a glass transition temperature of 10°C to 110°C is included. Preparing a composition for polymerization; And preparing a photocurable adhesive composition by performing bulk polymerization by irradiating light with a light amount of about 100 mJ/cm ² to about 1,000 mJ/cm ² for about 1 minute to about 10 minutes with respect to the polymerization composition. It provides a method for producing a photocurable adhesive composition containing. The photocurable adhesive composition described above in one embodiment may be prepared by the above manufacturing method.

In the above manufacturing method, a composition for polymerization comprising a (meth)acrylic monomer component comprising a first monomer having a glass transition temperature of -70°C to -20°C and a second monomer having a glass transition temperature of 10°C to 110°C You can prepare.

As the first monomer, for example, n-propyl acrylate, n-tetradecyl acrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, iso The composition for polymerization to include at least one selected from the group consisting of propyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, lauryl acrylate, lauryl methacrylate and combinations thereof It may be prepared, and specifically, may be prepared to include 2-ethylhexyl acrylate (EHA).

The composition for polymerization may be prepared so as not to include n-butyl acrylate as the first monomer, and accordingly, the odor generated during the operation may be removed, thereby realizing superior workability.

As the second monomer (light monomer), for example, at least one selected from the group consisting of methyl (meth)acrylate, ethyl (meth)acrylate, isobornyl acrylate (IBOA), acrylic acid and combinations thereof So that the composition for polymerization can be prepared.

The composition for polymerization may be prepared to include the sum of the (meth)acrylic monomer components at about 90% by weight to about 99.5% by weight.

The composition for polymerization may be prepared to further include a polymerization initiator, and may further include a photoinitiator as the polymerization initiator, and the photoinitiator is as described above in one embodiment.

The polymerization composition may be prepared not to contain an organic solvent. As described later, the polymerization composition does not contain a solvent because the polymerization reaction proceeds by a bulk photopolymerization reaction initiated by irradiation of light, and accordingly, solution polymerization containing a solvent or an emulsion requiring a large amount of additive is required Excellent eco-friendliness and high yield can be achieved compared to polymerization.

In addition, the photocurable pressure-sensitive adhesive composition can completely stop the polymerization reaction at room temperature by blocking light, and since the polymerization reaction does not proceed according to the temperature change, compared to the bulk thermal polymerization reaction in which the polymerization reaction is initiated by heat treatment. Excellent storage stability.

In the above production method, the photopolymerizable composition is prepared by performing bulk polymerization by irradiating light with a light amount of about 100 mJ/cm ² to about 1,000 mJ/cm ² for about 1 minute to about 10 minutes with respect to the polymerization composition. can do.

In the step of preparing the photocurable pressure-sensitive adhesive composition, a (meth)acrylic polymer is formed, and the weight ratio of the first monomer to the second monomer among all monomer components forming the (meth)acrylic polymer is about 1:0.3 to The (meth)acrylic polymer may be formed to be about 1:1. By being formed to have a weight ratio within the above range, the physical properties such as the glass transition temperature of the (meth)acrylic polymer can be appropriately adjusted to effectively improve high temperature properties.

The photocurable pressure-sensitive adhesive composition may be prepared to include the (meth)acrylic polymer in an amount of about 10% to about 40% by weight.

The (meth)acrylic polymer may be formed to have a glass transition temperature of about -60°C to about -10°C. By being formed to have a glass transition temperature within the above range, impact resistance, rebound resistance, and high temperature holding power can be effectively improved. Specifically, when the glass transition temperature is less than about -60°C, the high-temperature holding power is lowered, and when it is greater than about -10°C, there is a problem that the wettability to the substrate is lowered and the repellency is lowered.

The (meth)acrylic polymer may be formed to have a weight average molecular weight of about 500,000 g/mol to about 3,000,000 g/mol. It is formed to have a weight average molecular weight within the above range can improve the resistance to impact from the outside even under high temperature conditions.

The photocurable adhesive composition may be prepared as the (meth)acrylic syrup formed by the bulk polymerization as described above, and the (meth)acrylic syrup may be formed at a polymerization conversion rate of about 5% to about 30%. have.

The purpose and use of the curing process for curing the pressure-sensitive adhesive composition while forming the (meth)acrylic polymer appropriately by forming at a polymerization conversion rate within the above range to achieve excellent adhesion and high temperature properties when curing the pressure-sensitive adhesive composition Depending on the range, it can be adjusted in a wide range to give more various properties.

The photocurable composition gradually comprises a (meth)acrylic monomer as a separate component from the (meth)acrylic polymer, and the (meth)acrylic monomer is the (meth) formed by bulk polymerization of the composition for polymerization. It may be an unreacted monomer that is present in the acrylic syrup. Accordingly, the (meth)acrylic monomer may include the first monomer and the second monomer.

The total amount of the (meth)acrylic monomer may be included in the photocurable adhesive composition in an amount of about 55% to about 89% by weight.

In the step of preparing the photocurable adhesive composition, after the bulk polymerization is completed, a photoinitiator may be further mixed with the photocurable adhesive composition, and the type of the photoinitiator is as described above in one embodiment.

The photoinitiator may be mixed with about 0.1 parts by weight to about 0.5 parts by weight based on 100 parts by weight of the (meth)acrylic polymer. By mixing in a content within the above range, while sufficiently progressing the photocuring reaction, the unreacted photoinitiator remaining in the adhesive composition may be removed or minimized to effectively prevent physical property degradation due to migration.

In addition, in the step of preparing the photocurable adhesive composition, after the bulk polymerization is completed, one or more additives selected from the group consisting of, for example, a crosslinking agent, a UV stabilizer, an antioxidant, and combinations thereof are added to the photocurable adhesive composition. It can be further mixed, but is not limited thereto.

The photo-curable pressure-sensitive adhesive composition may be prepared to have a viscosity of about 2,000 cps to about 10,000 cps at about 20°C. By being prepared to have a viscosity within the above range, each component can be more uniformly mixed, but can be more easily processed into, for example, a film, tape, coating, or the like.

Hereinafter, specific embodiments of the present invention are presented. However, the examples described below are only for specifically illustrating or describing the present invention, and the present invention should not be limited thereby.

Example

Example One

Ethyl hexyl acrylate (EHA, glass transition temperature: -65°C), methyl acrylate (MA, glass transition temperature: 10°C), acrylic acid (AA, glass transition temperature: 106°C) at a weight ratio of 75:20:5 A composition for polymerization was prepared by mixing and stirring 99% by weight of the total monomer component and photoinitiator (IRG184).

Subsequently, a bulk polymerization reaction was performed by irradiating the composition for polymerization with a light amount of 100 mJ/cm ² to 1,000 mJ/cm ² for 10 minutes to form a (meth)acrylic syrup, and (meth) formed in the (meth)acrylic syrup. ) By adding 0.3 parts by weight of photoinitiator (IRG184) to 100 parts by weight of the acrylic polymer, a photocurable pressure-sensitive adhesive composition was prepared.

Example 2

Ethyl hexyl acrylate (EHA, glass transition temperature: -65°C), methyl acrylate (MA, glass transition temperature: 10°C), acrylic acid (AA, glass transition temperature: 106°C) at a weight ratio of 75:20:5 A photocurable pressure-sensitive adhesive composition was prepared in the same conditions and method as in Example 1, except that a composition for polymerization was prepared by mixing and stirring a total of 99% by weight of the monomer components and a photoinitiator (IRG184).

Example 3

Ethyl hexyl acrylate (EHA, glass transition temperature: -65°C), methyl acrylate (MA, glass transition temperature: 10°C), acrylic acid (AA, glass transition temperature: 106°C) in a weight ratio of 70:25:5 A photocurable pressure-sensitive adhesive composition was prepared in the same conditions and method as in Example 1, except that a composition for polymerization was prepared by mixing and stirring a total of 99% by weight of the monomer components and a photoinitiator (IRG184).

Example 4

Ethyl hexyl acrylate (EHA, glass transition temperature: -65°C), butyl acrylate (BA, glass transition temperature: -55°C), methyl acrylate (MA, glass transition temperature: 10°C), acrylic acid (AA, glass Same as Example 1, except that the composition for polymerization was prepared by mixing and stirring the total temperature of 99% by weight of the monomer component and the photoinitiator (IRG184), including a transition temperature of 106°C in a weight ratio of 60:20:15:5. A photocurable adhesive composition was prepared under conditions and methods.

Comparative example One

99% by weight of the total monomer component containing ethylhexyl acrylate (EHA, glass transition temperature: -65°C) and butyl acrylate (BA, glass transition temperature: -55°C) in a weight ratio of 60:40 and photoinitiator (IRG184 ) Was prepared by mixing and stirring to prepare a photocurable pressure-sensitive adhesive composition in the same conditions and method as in Example 1, except that the composition for polymerization was prepared.

Comparative example 2

Mix and stir 99% by weight of the total amount of the monomer component and photoinitiator (IRG184) containing methyl acrylate (MA, glass transition temperature: 10°C), acrylic acid (AA, glass transition temperature: 106°C) in a weight ratio of 95:5 By preparing a composition for polymerization, a photocurable pressure-sensitive adhesive composition was prepared under the same conditions and methods as in Example 1.

Comparative example 3

An organic solvent was further mixed with the composition for polymerization prepared in Comparative Example 1, and heat-treated at a temperature of 50°C to 80°C for 7 hours to perform a solution polymerization reaction to form a (meth)acrylic syrup and the (meth)acrylic syrup. A photo-curable pressure-sensitive adhesive composition was prepared by further mixing 0.3 parts by weight of a photoinitiator (IRG184) with respect to 100 parts by weight of the (meth)acrylic polymer formed therein.

Experimental Example

The photocurable adhesive compositions according to Examples 1-4 and Comparative Examples 1-3 were irradiated with UV at a light amount of 150 mJ/cm ² for 3 minutes to form adhesive films having a thickness of 75 μm, respectively.

Subsequently, various physical properties for each of the adhesive films were evaluated and are shown in Table 1 below.

Assessment Methods

Experimental Example 1: Curing degree

Measurement method: Each adhesive film was cut to a size of 5 mm ⅹ 5 mm ⅹ 5 mm to prepare a specimen, and then weighed before dipping it in a solvent to obtain the first mass.

Subsequently, the specimen was dipped in an ethyl acetate solvent, left at room temperature for 24 hours, filtered using a 200 mesh wire mesh, and then the remaining specimen was dried at 110° C. for 2 hours to measure the mass (dry mass) of the specimen obtained later Mass was obtained.

With the initial mass as W _i and the latter mass as W _f , the curing degree was calculated by the following Equation 1:

[Calculation formula 1]

Curing degree (%) = W _f /W _i ⅹ 100

Experimental Example 2: Impact strength (impact resistance)

Measurement method: The adhesive films according to Examples 1-4 and Comparative Examples 1-3 were measured using a Dupont type impact tester.

Specifically, each of the adhesive films according to Examples 1-4 and Comparative Examples 1-3 on a polycarbonate (PC) substrate having a size of 50 mm×50 mm×2 mm with a hole having a diameter of 10 mm in the center. After attaching a glass of 20㎜x20㎜x3㎜ through a medium, the hole is attached to the center, and then compressed for 1 minute with 3kg force, and then left for 24 hours under conditions of RT 23°C and RH 50% to prepare a laminated specimen. Did.

A drop impact test was performed by observing whether the glass and the adhesive film fell off while dropping a weight of 100 g with respect to the glass surface of the laminate specimen from 50 mm to 500 mm in height by 50 mm sequentially.

At this time, when the glass and the adhesive film were not removed, a drop impact test was performed while increasing the weight of the weights to 150 g, 200 g, 300 g, and 400 g until they were removed, and when the weight was 150 g, 350 ~ For 500 mm and 200 g, 400 to 500 mm, and for 300 g and 400 g, they were dropped at positions sequentially raised by 50 mm within a height of 350 to 500 mm.

Accordingly, for each of the adhesive films for displays according to Examples 1-4 and Comparative Examples 1-3, the weight and height of the weight when the glass and the adhesive film are removed are measured, and from these, in this technical field. Impact strength was calculated according to known physical laws.

Experimental Example 3: retention

Measurement method: The adhesive films according to Examples 1-4 and Comparative Examples 1-3 were cut to a size of 25 mm×25 mm to prepare each specimen.

Two 25 mm×50 mm SUS 304 1/2H blocks were prepared, which were washed once with IPA and three times with heptane.

Subsequently, one of the blocks is attached to one surface of each specimen, and the other of the blocks is attached to the other surface of each specimen, and the 7 kg rollers are attached to the blocks so that they protrude slightly in opposite directions. Each press was reciprocated at a speed of 25 mm/sec, and then pressed, and then left at RT 23° C. and RH 50% for 1 hour to prepare each sample.

In addition, one of each of the blocks protruding from both ends of the sample is fixed to a predetermined upper surface (upper surface), and a 500 g weight is suspended from the other, and a temperature of 85° C. is applied to force in the direction of gravity. And it was put into a high-temperature and high-humidity chamber with a humidity condition of 85% RH and continuously observed for 24 hours to measure the time at the time of dropping, and when dropping did not occur, it was evaluated as having excellent holding power.

Experimental Example 4: Repulsion resistance

Measurement method: The adhesive films according to Examples 1-4 and Comparative Examples 1-3 were cut to a size of 150 mmX25 mm to prepare each specimen.

An aluminum substrate having a size of 155mmX30mmX0.5mm and a polycarbonate substrate having a size of 170mmX35mmX2mm were prepared and washed once with IPA and three times with heptane.

Subsequently, the specimen is attached to the aluminum substrate so that one edge portion of the aluminum substrate coincides with one edge portion of the specimen, and is pressed and pressed twice with a 7 kg roller, and then the opposite side of the surface to which the aluminum substrate of the specimen is attached. Attach the polycarbonate substrate to, but attach the aluminum substrate to the center of the polycarbonate substrate while one edge portion of the polycarbonate substrate coincides with one edge portion of the aluminum substrate, and press and reciprocate twice with a 7 kg roller. Subsequently, each sample was prepared by standing at RT 23° C. and RH 50% for 24 hours.

In addition, each sample was then fitted to both ends of the test jig (Al material, 210mmX165mmX5mm) of the universal tester, placed in a high temperature and high humidity chamber at a temperature of 85°C and a humidity of 85% RH, and continuously observed for 2 hours. The time at the time of dropping was measured, and when dropping did not occur, it was evaluated as having excellent rebound resistance.

Experimental Example 5: Storage stability against temperature

Measurement method: The (meth)acrylic syrup according to Examples 1-4 and Comparative Examples 1-3 was maintained in a high temperature chamber (Geotech, ON-22) at 60° C. for 24 hours, and then whether the conversion rate was changed or not. By measuring, the case where the conversion rate was not changed was evaluated as having excellent storage stability with respect to temperature, and marked as “○”, and when the conversion rate was increased, the storage stability with respect to temperature was evaluated as being inferior and was marked with “Ⅹ”.

Curing degree (%) Impact strength (mJ) High temperature holding power Repulsion resistance Storage stability against temperature Example 1 65 1000 24hr (excellent) 24hr (excellent) Ο Example 2 62 900 24hr (excellent) 24hr (excellent) Ο Example 3 68 920 24hr (excellent) 24hr (excellent) Ο Example 4 60 500 24hr (excellent) 2hr Ο Comparative Example 1 72 420 24hr (excellent) 1hr Ο Comparative Example 2 69 250 24hr (excellent) 10min Ο Comparative Example 3 70 300 3hr 1hr Ⅹ

As shown in Table 1, in the case of the pressure-sensitive adhesive films prepared from the photocurable pressure-sensitive adhesive compositions according to Examples 1 to 4, it was clearly confirmed that both the impact strength, high-temperature retention, and rebound resistance properties were implemented at excellent levels. Particularly, in the case of the adhesive films prepared from the photocurable adhesive compositions according to Examples 1 to 3, the impact strength and the high temperature retention force are realized at an excellent level, and the repellency is improved more effectively, and no odor is generated in the working process. Excellent workability was realized.

On the other hand, in the case of the adhesive films prepared from the photocurable adhesive compositions according to Comparative Examples 1 to 4, it was clearly confirmed that the impact strength was significantly inferior, and in particular, the repulsion resistance was significantly inferior to less than 1 hour. In addition, in Comparative Examples 1 and 3, the odor was generated and the workability was low, and in the case of Comparative Example 3, the storage stability against temperature was also inferior.

Claims (18)

(Meth)acrylic polymer in which a (meth)acrylic monomer component including a first monomer having a glass transition temperature of -70°C to -20°C and a second monomer having a glass transition temperature of 10°C to 110°C is polymerized; (Meth)acrylic monomers; And a photoinitiator,
The (meth) acrylic polymer containing 10% by weight to 40% by weight
Photocurable adhesive composition.
According to claim 1,
Free of organic solvents
Photocurable adhesive composition.
According to claim 1,
The weight ratio of the first monomer to the second monomer among all the monomer components forming the (meth)acrylic polymer is 1:0.3 to 1:1
Photocurable adhesive composition.
According to claim 1,
The glass transition temperature of the (meth)acrylic polymer is -60°C to -10°C.
Photocurable adhesive composition.
According to claim 1,
The (meth) acrylic polymer has a weight average molecular weight of 500,000 g/mol to 3,000,000 g/mol
Photocurable adhesive composition.
delete According to claim 1,
As the first monomer, does not contain n-butyl acrylate
Photocurable adhesive composition.
According to claim 1,
The total amount of the (meth) acrylic monomer containing 55% to 89% by weight of photocurable
Photocurable adhesive composition.
According to claim 1,
A (meth)acrylic syrup formed by performing bulk polymerization by irradiation of light with respect to a polymerization composition comprising a (meth)acrylic monomer component comprising the first monomer and the second monomer.
Photocurable adhesive composition.
The method of claim 9,
The (meth) acrylic syrup has a polymerization conversion rate of 5% to 30%
Photocurable adhesive composition.
An adhesive film comprising a cured product of the photocurable adhesive composition according to any one of claims 1 to 5 or 7 to 10.
The method of claim 11,
The cured product has a curing degree of 50% to 80% according to the following Equation 1
Adhesive film:
[Calculation formula 1]
Curing degree (%) = W _f /W _i ⅹ 100
In the calculation formula 1, W _i means the weight before dipping the cured sample to a predetermined size and dipping it in the solvent of the obtained specimen, and W _f is immersing the specimen in the solvent and allowed to stand for a period of time, and then using a strainer. It means the weight of the specimen left after filtering.
The method of claim 11,
Impact strength of 500mJ to 1,000mJ
Adhesive film.
The method of claim 13,
Adhesion of 2,000 g/in to 3,000 g/in
Adhesive film.
Preparing a polymerization composition comprising a (meth)acrylic monomer component comprising a first monomer having a glass transition temperature of -70°C to -20°C and a second monomer having a glass transition temperature of 10°C to 110°C; And
Including the step of preparing a photocurable adhesive composition by performing bulk polymerization by irradiating light for 1 minute to 10 minutes with a light amount of 100 mJ/cm ² to 1,000 mJ/cm ² with respect to the polymerization composition.
In the step of preparing the photo-curable adhesive composition, (meth) acrylic polymer is formed,
The photocurable pressure-sensitive adhesive composition comprises the (meth)acrylic polymer in an amount of 10% to 40% by weight
Method of manufacturing a photocurable adhesive composition.
The method of claim 15,
The composition for polymerization is prepared so as not to contain an organic solvent
Method of manufacturing a photocurable adhesive composition.
The method of claim 15,
The composition for polymerization is prepared as the first monomer so as not to contain n-butyl acrylate.
Method of manufacturing a photocurable adhesive composition.
The method of claim 15,
The (meth)acrylic polymer is formed so that the weight ratio of the first monomer to the second monomer among all the monomer components forming the (meth)acrylic polymer is 1:0.3 to 1:1.
Method of manufacturing a photocurable adhesive composition.